Publications by authors named "Zahid Latif"

35 Publications

Identification of a Novel Homozygous Missense (c.443A>T:p.N148I) Mutation in in a Kashmiri Family with Bardet-Biedl Syndrome.

Biomed Res Int 2021 23;2021:6626015. Epub 2021 Feb 23.

Department of Zoology, Mirpur University of Science and Technology (MUST), Mirpur AJK, Pakistan.

Background: Bardet-Biedl syndrome (BBS) is a rare autosomal recessive inherited disorder with distinctive clinical feature such as obesity, degeneration of retina, polydactyly, and renal abnormalities. The study was aimed at finding out the disease-causing variant/s in patients exhibiting clinical features of BBS.

Methods: The identification of disease-causing variant was done by using whole exome sequencing on Illumina HiSeq 4000 platform involving the SeqCap EZ Exome v3 kit (Roche NimbleGen). The identified variant was further validated by Sanger sequencing.

Results: WES revealed a novel homozygous missense mutation (NM_031885: c.443A>T:p.N148I) in exon 3 of the gene. Sanger sequencing confirmed this variant as homozygous in both affected subjects and heterozygous in obligate parents, demonstrating autosomal recessive inheritance pattern. To the best of our knowledge, this variant was not present in literature and all publically available databases. The candidate variant is predicted to be pathogenic by a set of in-silico softwares.

Conclusion: Clinical and genetic spectrum of BBS and BBS-like disorders is not completely defined in the Pakistani as well as in Kashmiri population. Therefore, more comprehensive genetic studies are required to gain insights into genotype-phenotype associations to facilitate carrier screening and genetic counseling of families with such disorders.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2021/6626015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7925018PMC
February 2021

Sequencing and Characterization of Mitochondrial Protein-Coding Genes for (Cypriniformes: Cyprinidae) with Phylogenetic Consideration.

Biomed Res Int 2020 7;2020:5980135. Epub 2020 Dec 7.

Department of Biotechnology, University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan.

The present study was conducted to get more information about the genome and locate the taxonomic position of in Schizothoracinae through mitochondrial 13 protein-coding genes (PCGs). These PCGs for were found to be 11409 bps in length ranging from 165 (ATPase 8) to 1824 bps (NADH dehydrogenase subunit 5) and encode 3801 amino acids. In these PCGs, 4 genes overlap on the similar strands, while one shown on the opposite one: ATPase 6+8 and NADH dehydrogenase subunit 4+4L overlap by 7 nucleotides. Similarly, ND5-ND6 overlap by 4 nucleotides, while ATP6 and COIII overlap by 1 nucleotide. Similarly, four commonly used amino acids in were Leu (15.6 %), Ile (10.12 %), Thr (8.12 %), and Ala (8.7 %). The results presented that COII, COIII, NDI, ND4L, and Cytb had substantial amino acid conservation as compared to the COI gene. Through phylogenetic analysis, it was observed that is closely linked with , , , and with high bootstrap values. The present study provided more genomic data to know the diversity of the mitochondrial genome and its molecular evolution in Schizothoracinae.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2020/5980135DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7787735PMC
December 2020

Relationship between economic growth and CO emissions: does governance matter?

Environ Sci Pollut Res Int 2020 May 9;27(14):17221-17228. Epub 2020 Mar 9.

School of Business, Guangdong university of foreign studies Guangzhou, 510006, Guangzhou, China.

The environmental stress due to massive CO emissions is a critical issue for scholars and policymakers. Many studies have discussed various determinants of environmental pollution both from theoretical and empirical perspectives. However, how governance influences the nexus between economic growth and CO emissions is rarely studied. Hence this study investigates the relationship between economic growth, governance and CO emissions within the framework of the Environmental Kuznets Curve for five high CO emission countries over 1996-2017. Empirical results from the panel data estimation methods reflect that measures of governance influence emission levels differently in high CO emission countries. Overall, political, economic and institutional governance enhance environmental quality. According to the results, provision of good governance needs to exercise effective measures to enhance and protect environmental quality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-020-08142-3DOI Listing
May 2020

Reducing carbon emissions from collaborative distribution: a case study of urban express in China.

Environ Sci Pollut Res Int 2020 May 2;27(14):16215-16230. Epub 2020 Mar 2.

School of Economics and Management, Beijing University of Posts and Telecommunications, Beijing, People's Republic of China.

The booming development of e-commerce has brought about rapid growth in the express delivery industry in China. However, urban express distribution is increasingly difficult and seriously affecting the traffic, safety, and environmental conditions of cities due to small, scattered end points, unreasonable allocation of resources, and seriously repeated resource waste. Therefore, there is an urgent need to solve the problems associated with the unreasonable resource allocation of express distribution. In the context of green logistics, a new mode of collaborative distribution based on intelligent end service station (IESS) is proposed. Following the measurement models of carbon emissions, before and after collaborative distributions are provided to prove the environmental benefits of the new mode. The influencing factors considered in the models are the average daily distribution volume, number of distribution sections, vehicle ownership of various types, and their capacity, use, fuel, and power consumption. To verify the models' validity, we conduct an empirical study of five express enterprises in China and make a comparative analysis on the results, which show that the implementation of collaborative distribution can extremely reduce carbon emissions and improve the overall load rate of vehicles. Specially, the use of new energy vehicles can contribute significantly to energy conservation and emissions reduction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-020-08143-2DOI Listing
May 2020

Confirmation of the Role of DHX38 in the Etiology of Early-Onset Retinitis Pigmentosa.

Invest Ophthalmol Vis Sci 2018 09;59(11):4552-4557

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States.

Purpose: Retinitis pigmentosa (RP) is a genetically heterogeneous trait with autosomal-recessive (ar) inheritance underlying 50% of genetic disease cases. Sixty-one arRP genes have been identified, and recently, DHX38 has been reported as a potential candidate gene for arRP with only a single family reported with a variant of unknown significance. We identified a missense variant in DHX38 that co-segregates with the arRP phenotype in two Pakistani families confirming the involvement of DHX38 in the etiology of early-onset RP.

Methods: Exome sequencing was performed using two DNA samples from affected members of Pakistani families (MA88 and MA157) with early onset arRP. Sanger sequencing of DNA samples from all family members confirmed the segregation of candidate variant within both families.

Results: A novel missense DHX38 variant c.971G>A; p.(Arg324Gln) was identified which segregates with the arRP phenotype and yielded a logarithm of the odds (LOD) score of 5.0 and 4.3 for families MA88 and MA157, respectively. This variant is predicted to be conserved and deleterious by several bioinformatics tools.

Conclusions: We identified a second deleterious DHX38 variant that segregates with arRP in two families, providing additional evidence that DHX38 is involved in RP etiology. DHX38 encodes for pre-mRNA splicing factor PRP16, which is important in catalyzing pre-mRNA splicing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1167/iovs.18-23849DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6133250PMC
September 2018

Identification of a novel homozygous TRAPPC9 gene mutation causing non-syndromic intellectual disability, speech disorder, and secondary microcephaly.

Am J Med Genet B Neuropsychiatr Genet 2017 Dec 14;174(8):839-845. Epub 2017 Oct 14.

Charité - Universitätsmedizin Berlin, Institute of Neuroanatomy and Cell Biology, Berlin, Germany.

TRAPPC9 gene mutations have been linked recently to autosomal recessive mental retardation 13 (MRT13; MIM#613192) with only eight families reported world-wide. We assessed patients from two consanguineous pedigrees of Pakistani descent with non-syndromic intellectual disability and postnatal microcephaly through whole exome sequencing (WES) and cosegregation analysis. Here we report six further patients from two pedigrees with homozygous TRAPPC9 gene mutations, the novel nonsense mutation c.2065G>T (p.E689*) and the previously identified nonsense mutation c.1423C>T (p.R475*). We provide an overview of previously reported clinical features and highlight common symptoms and variability of MRT13. Common findings are intellectual disability and absent speech, and frequently microcephaly, motor delay and pathological findings on MRI including diminished cerebral white matter volume are present. Mutations in TRAPPC9 should be considered in non-syndromic autosomal recessive intellectual disability with severe speech disorder.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ajmg.b.32602DOI Listing
December 2017

Structural Features of Europium(II)-Containing Cryptates That Influence Relaxivity.

Chemistry 2017 Nov 22;23(61):15404-15414. Epub 2017 Aug 22.

Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA.

Eu -containing complexes were studied with respect to properties relevant to their use as contrast agents for magnetic resonance imaging. The influences of molecular parameters and field strength on relaxivity were studied for a series of Eu -containing cryptates and their adducts with β-cyclodextrins, poly-β-cyclodextrins, and human serum albumin. Solid- and solution-phase characterization of Eu -containing complexes is presented that demonstrates the presence of inner-sphere molecules of water. Additionally, relaxivity, water-exchange rate, rotational correlation time, and electronic relaxation times were determined using variable-temperature O NMR, nuclear magnetic relaxation dispersion, and electron paramagnetic resonance spectroscopic techniques. These results are expected to be instrumental in the design of future Eu -based contrast agents.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/chem.201702158DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5668193PMC
November 2017

The Relationship Between Brain MR Spectroscopy and Disability in Multiple Sclerosis: 20-Year Data from the U.S. Glatiramer Acetate Extension Study.

J Neuroimaging 2017 01 23;27(1):97-106. Epub 2016 May 23.

Teva Pharmaceutical Industries, Netanya, Israel.

Background And Purpose: Conventional MRI techniques do not necessarily provide information about multiple sclerosis (MS) disease pathology or progression. Nonconventional MRI techniques, including proton magnetic resonance spectroscopy ( H-MRS), are increasingly used to improve the qualitative and quantitative specificity of MR images. This study explores potential correlations between MRI measures of disease and disability progression as measured by the Expanded Disability Status Scale (EDSS), Functional Systems (FS), and ambulation index scores in a unique cohort of MS patients treated with glatiramer acetate that has been closely monitored for over 20 years.

Methods: This was a multicenter, open-label, cross-sectional MRI substudy among participants in the GA-9004 open-label extension of the 36-month, double-blind GA-9001 study, timed to coincide with the prospectively planned 20-year clinical exam.

Results: Of 64 patients who participated in the MRI substudy, results are presented for the 39 patients (61%) who had a H-MRS assessment at 20 years of treatment. Both total N-acetylaspartate relative to total creatinine (tNAA/tCr) concentration ratio and T1 lesion volume were found to be robustly associated with disability levels with different statistical approaches. Gray matter (GM) volume was found to be a more consistent parameter than white matter (WM) volume for disability allocation. The elastic net algorithm showed a trade-off between WM and GM volumes for disability estimation when different disability definitions were used.

Conclusions: Among patients with MS receiving long-term glatiramer acetate therapy, consistent effects on disability levels indicated by EDSS and pyramidal FS score thresholds were found for tNAA/tCr concentration ratio and T1 lesion volume.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jon.12358DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5248608PMC
January 2017

Innovation in health and care.

Authors:
Zahid Latif

Perspect Public Health 2016 Mar;136(2):58

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1757913915626357DOI Listing
March 2016

Serum Zinc Level in Children Presenting with Febrile Seizures.

Pak J Med Sci 2013 Jul;29(4):1008-11

Objective: To determine the frequency of low serum zinc level in children presenting with febrile seizures at The Children's Hospital and the Institute of Child Health (CH/ICH) Multan.

Methods: This is an observational cross sectional study conducted at the Department of Pediatric Medicine, The Children's Hospital and the Institute of Child Health, Multan from September 2010 to March 2011. Children (6 months to 6 years of age) presenting with febrile seizures who satisfied inclusion and exclusion criteria were enrolled for the study. Cause of fever was determined after detailed history, physical examination and relevant investigations. Four milliliters centrifuged blood sample was preserved in acid washed test tube. Separated serum was used to measure serum zinc level by employing Randox kit on auto-analyzer in all cases. The outcome variable (serum zinc level) was recorded on a predesigned proforma.

Results: Out of 100 enrolled children, there were 66 (66%) male with male to female ratio of 1:0.52. Mean age of the children was 23.97±14.45 months. Upper respiratory tract infection was the most frequent cause of fever apparent in 24 children (24%) followed by tonsillitis 17 (17%), pneumonia 16 (16%), urinary tract infection 16 (16%), otitis media 15 (15%), and bronchiolitis 12 (12%). Frequency of low serum zinc level was 26% in children with febrile seizures.

Conclusion: Zinc deficiency could be a potential risk factor for febrile seizure in children.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3817762PMC
July 2013

MR imaging of the yucatan pig head and neck vasculature.

J Magn Reson Imaging 2013 Sep 24;38(3):641-9. Epub 2013 Jan 24.

Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA.

Purpose: To evaluate the cerebral venous drainage system of the swine as a probable model to test whether extracranial venous abnormalities may play a role in neurodegenerative diseases as reported recently in multiple sclerosis.

Materials And Methods: Three Yucatan micropigs, 5 to 7 months old, were scanned with a comprehensive MRI protocol at 3 Tesla. The vascular anatomy of the head and neck was imaged using conventional and angiographic MR sequences. Phase-contrast MR images were collected at multiple levels of the neck and intracranial space to monitor flow.

Results: Three large cervical veins were observed; the external jugular vein draining the olfactory and gustatory tissues; the internal jugular vein (IJV) draining the cavernous sinus as well as surrounding soft tissues in the neck; and the ventral vertebral venous plexus (VVVP) surrounding the dural sac and paraspinal region. The majority of the cerebral blood flow in the pig appears to drain through the VVVP. Flow through the IJV comprised a nondominant component. Anastamoses were observed connecting the major veins of the neck bilaterally.

Conclusion: The dominance of outflow from the brain to the VVVP may be analogous to the typical dominance of the IJVs in humans in the supine position.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jmri.24003DOI Listing
September 2013

What is the technology strategy board?

Authors:
Zahid Latif

Health Serv J 2012 Nov;122(6327):26

Technology Strategy Board.

View Article and Find Full Text PDF

Download full-text PDF

Source
November 2012

Maternal Body Composition and Its Relationship to Infant Breast Milk Intake in Rural Pakistan.

Food Nutr Sci 2011 Nov;2(9):932-937

Pakistan Institute of Nuclear Science and Technology, Islamabad, Pakistan.

Some women in rural Pakistan are chronically undernourished, and consequently underweight. Concerns have been expressed that the degree of undernourishment might be sufficiently severe to affect lactation performance. We have obtained data on maternal body composition and infant breast milk intake using stable isotope methods in a group of thirty three mother and infant pairs at approximately six months of age. The maternal body mass index ranged from 16.6 to 29.1 kg·m(-2). In this population we found that exclusive breast-feeding tended to be associated with lower maternal body fat, and that there was no evidence for compromised lactational performance due to malnourishment. Finally we note that when our data is combined with that from other studies there may be a generalised negative correlation between breast milk intake and maternal body fat.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4236/fns.2011.29127DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3442252PMC
November 2011

Magnetic resonance imaging-based relationships between neck muscle cross-sectional area and neck circumference for adults and children.

Eur Spine J 2013 Feb 28;22(2):446-52. Epub 2012 Aug 28.

Department of Biomedical Engineering, Wayne State University, 818W Hancock, Detroit, MI 48201, USA.

Background: Computer models and human surrogates used to study the forces and motion of the human neck under various loading conditions are based solely on adult data. Pediatric computer models and dummy surrogates used to improve the safety of children could be improved with the inclusion of previously unavailable pediatric muscle data.

Methods: Measurements of neck circumference and neck muscle cross-sectional area (CSA) were taken from ten 50th percentile adult male and ten 10-year old male volunteer subjects. Muscle cross-sectional areas were calculated from magnetic resonance images of axial cross-sections of the neck.

Results: Neck muscle cross-sectional area was calculated for six muscles/muscle groups. A power-law regression analysis was used to describe the relationship between neck circumference and neck muscle cross-sectional area.

Conclusions: The cross-sectional area and the power-law functions determined by the data in this study provide a means of calculating muscle cross-sectional area for young children, where such data are currently unavailable. This will provide an opportunity to develop more representative pediatric neck models.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00586-012-2482-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3555627PMC
February 2013

Using magnetic resonance imaging as a means to study chronic cerebral spinal venous insufficiency in multiple sclerosis patients.

Tech Vasc Interv Radiol 2012 Jun;15(2):101-12

Magnetic Resonance Innovations, Inc, Detroit, MI 48202, USA.

The goal of this work is to present a broad magnetic resonance imaging (MRI) protocol for use in the study of chronic cerebrospinal venous insufficiency (CCSVI). The CCSVI MRI protocol includes the following sequences: time-resolved contrast-enhanced 3D MR angiography, 2D time-of-flight MR venography, and 3D volumetric interpolated breath-hold examination to assess venous structural abnormalities; phase-contrast MR imaging at different levels in the neck and thoracic cavity to quantify flow through the veins, arteries, and cerebrospinal fluid; T2-weighted imaging, T2-weighted fluid-attenuated inversion recovery, and pre- and post-contrast T1-weighted imaging of the brain for examinations of parenchymal lesions; and finally, susceptibility-weighted imaging for quantification of iron deposition in the brain. Data from 111 clinically definite multiple sclerosis patients were assessed for potential structural and flow CCSVI risk criteria, including stenosis, atresia, aplasia, dominant to subdominant venous flow ratio (D:sD), and the sum of their flow rates. Of the 111 patients, 50 (45%) were determined to be nonstenotic (NST) with no stenosis or atresia in their internal jugular veins (IJV), and the rest 61 (55%) were stenotic (ST) having at least one internal jugular vein stenosis or atresia. No occurrence of aplasia was observed. A D:sD of greater than 3:1 was observed in 15 (24.6%) patients of the ST group and 2 (4.0%) patients of the NST group. A sum of dominant and subdominant venous flow rate of <8 mL/s was observed in 22 (36.1%) patients of the ST group and 6 (12.0%) patients of the NST group. MRI provides valuable information in the observation of potential CCSVI risk factors. Low total flow in the 2 dominant veins seemed to be the strongest indicator for risk of having stenoses in the multiple sclerosis population.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1053/j.tvir.2012.02.003DOI Listing
June 2012

Mental health legislation in Ireland: a lot done, more to do.

J Am Acad Psychiatry Law 2012 ;40(2):266-9

Limerick Mental Health Services, St. Annes Day Hospital, Limerick, Republic of Ireland.

Mental health legislation is necessary to protect the rights of people with mental disorders, a vulnerable section of society. Ireland's new Mental Health Act 2001 was fully implemented in 2006 with the intent of bringing Irish legislation more in line with international standards, such as the European Convention on Human Rights and United Nations Principles for the Protection of Persons with Mental Illness. The new legislation introduced several important reforms in relation to involuntary admission, independent reviews of involuntary detention, consent to treatment, and treatment of children and adolescents. It also presented significant challenges in terms of service delivery and resources within Irish mental health services. Both mental health service users and providers reported a range of difficulties with the new legislation. In this article, we analyze the Irish Mental Health Act focusing on the enhanced protection that it provides for patients, but also highlighting some areas of concern such as the conduct of mental health tribunals, consent and capacity problems, resource allocation, and disruptions in mental health service delivery.
View Article and Find Full Text PDF

Download full-text PDF

Source
October 2012

Aerosol delivery during high frequency jet ventilation: an MRI evaluation.

Respir Care 2012 Nov 14;57(11):1901-7. Epub 2012 May 14.

Department of Pediatrics, Children's Hospital of Michigan, Detroit, MI 48201, USA.

Background: We have previously demonstrated aerosol delivery during conventional and high frequency oscillatory (HFOV) ventilation using magnetic resonance imaging (MRI) in piglets. There are no reports on aerosol delivery during high frequency jet ventilation (HFJV).

Objective: To compare delivery of aerosolized gadopentetate dimeglumine (Gd-DTPA) in 3 neonatal ventilator circuits: conventional mechanical ventilation, HFOV, and HFJV.

Methods: Aerosols of Gd-DTPA (0.025 mol/L) generated using a jet nebulizer placed in the inspiratory limb of each ventilator were delivered into an in vitro lung model simultaneously. Multi-slice T1-weighted spin-echo sequence scans were obtained prior to and after 10 and 20 min of cumulative aerosol delivery. Gd-DTPA concentration was calculated from signal intensity changes, and the total amount of Gd-DTPA was estimated.

Results: Gd-DTPA was visualized in the lung model at 10 and 20 min for all 3 ventilators. Gd-DTPA delivery was highest with conventional mechanical ventilation (1.92 μmol at 10 min, 2.89 μmol at 20 min), followed by HFJV (1.59 μmol at 10 min, 1.98 μmol at 20 min) and HFOV (0.79 μmol at 10 min, 1.00 μmol at 20 min).

Conclusions: This is the first report of effective aerosol delivery in a neonatal HFJV circuit. Future studies are needed for more accurate quantification of aerosol deposition.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4187/respcare.01746DOI Listing
November 2012

Isolation of natural products by preparative high performance liquid chromatography (prep-HPLC).

Methods Mol Biol 2012 ;864:255-74

Technology Strategy Board, Swindon, UK.

Preparative HPLC (prep-HPLC) has emerged as a mainstay of natural products isolation and purification. The various modes available to date, e.g. normal phase, reversed-phase, size exclusion, and ion exchange, can be used to purify most classes of natural products. This chapter presents an overview of the different modes along with a practical guide as to how to purify a natural product using the most robust and widely used of the modes, namely reversed-phase prep-HPLC. Instrumentation set-up and detection methods, sample preparation, method development, and sample work up are also discussed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/978-1-61779-624-1_10DOI Listing
June 2012

Patients with multiple sclerosis with structural venous abnormalities on MR imaging exhibit an abnormal flow distribution of the internal jugular veins.

J Vasc Interv Radiol 2012 Jan;23(1):60-8.e1-3

Department of Biomedical Engineering, Wayne State University, Detroit, MI 48201, USA.

Purpose: To evaluate extracranial venous structural and flow characteristics in patients with multiple sclerosis (MS).

Materials And Methods: Two hundred subjects with MS from two sites (n = 100 each) were evaluated with magnetic resonance (MR) imaging at 3 T. Contrast-enhanced time-resolved MR angiography and time-of-flight MR venography were used to assess vascular anatomy. Two-dimensional phase-contrast MR imaging was used to quantify blood flow. The MS population was divided into two groups: those with evident internal jugular vein (IJV) stenoses (stenotic group) and those without (nonstenotic group).

Results: Of the 200 patients, 136 (68%) showed IJV structural abnormalities, including unilateral or bilateral stenoses at different levels in the neck (n = 101; 50.5%) and atresia (n = 35; 17.5%). The total IJV flow normalized to the total arterial flow of the stenotic group (56% ± 22) was significantly lower than that of the nonstenotic group (77% ± 14; P < .001). The arterial/venous flow mismatch in the stenotic group (12% ± 15) was significantly greater than that in the nonstenotic group (6% ± 12; P < .001). The ratio of subdominant venous flow rate (Fsd) to dominant venous flow rate (Fd) for the stenotic group (0.38 ± 0.27) was significantly lower than for the nonstenotic group (0.59 ± 0.23; P < .001). The majority of the stenotic group (67%) also had an Fsd of less than 3 mL/s, a Fd/Fsd ratio greater than 3:1, and/or a total IJV flow rate of less than 8 mL/s.

Conclusions: MR imaging provides a noninvasive means to separate stenotic from nonstenotic MS cases. The former group was more prevalent in the present MS population and carried significantly less flow in the IJVs than the latter.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jvir.2011.09.027DOI Listing
January 2012

Effective aerosol delivery during high-frequency ventilation in neonatal pigs.

Respirology 2010 Apr 19;15(3):551-5. Epub 2010 Mar 19.

Department of Pediatrics, Children's Hospital of Michigan, 3901 Beaubien Blvd., 4H42, Detroit, MI 48201, USA.

Background And Objective: Pulmonary delivery of aerosols during high-frequency oscillatory ventilation (HFOV) has not been studied in vivo. This study investigated the pulmonary delivery of aerosolized gadopentetate dimeglumine (Gd-DTPA) in a HFOV circuit in piglets using MRI to visualize contrast excretion in the kidneys.

Methods: Four ventilated piglets (3-7 days old, 1.7-2.4 kg at birth) received aerosolized Gd-DTPA in a HFOV circuit for different durations of time (60, 30, 20 and 10 min). Aerosols were generated using the MiniHeart jet nebulizer. As MR-compatible HFOV was not available, aerosolized Gd-DTPA was administered in the HFOV circuit outside the MR suite followed by MRI 10-20 min later. T1-weighted spin echo sequences were obtained using the Bruker/Siemens 4T MR scanner.

Results: Enhancement of the kidneys was observed 10 min after aerosol initiation in piglets who received Gd-DTPA aerosol for 60, 30 and 20 min in the HFOV circuit but not in the piglet who received aerosol for 10 min. Renal concentration of Gd-DTPA, determined from the signal intensity, increased linearly with time until 40 min post Gd-DTPA delivery.

Conclusions: Effective pulmonary aerosol delivery during HFOV was confirmed by contrast visualization in the kidneys within 30 min of aerosol initiation reflecting, alveolar absorption, glomerular filtration and renal concentration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1440-1843.2010.01714.xDOI Listing
April 2010

New executive clinical director posts in Ireland.

Authors:
Zahid Latif

Ir J Psychol Med 2009 Sep;26(3):151-152

St Davnet's Hospital,Monaghan, Co. Monaghan,Ireland.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1017/S0790966700000501DOI Listing
September 2009

Psychiatry in Ireland.

Authors:
Zahid Latif

Int Psychiatry 2009 Apr 1;6(2):36-38. Epub 2009 Apr 1.

Department of Community Rehabilitation Psychiatry Services, Cavan/Monaghan Mental Health Services, St Davnet's Hospital, Monaghan, Ireland.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6734875PMC
April 2009

Characterizing iron deposition in multiple sclerosis lesions using susceptibility weighted imaging.

J Magn Reson Imaging 2009 Mar;29(3):537-44

Department of Radiology, Wayne State University, Detroit, Michigan 48201, USA.

Purpose: To investigate whether the variable forms of putative iron deposition seen with susceptibility weighted imaging (SWI) will lead to a set of multiple sclerosis (MS) lesion characteristics different than that seen in conventional MR imaging.

Materials And Methods: Twenty-seven clinically definite MS patients underwent brain scans using magnetic resonance imaging including: pre- and postcontrast T1-weighted imaging, T2-weighted imaging, FLAIR, and SWI at 1.5 T, 3 T, and 4 T. MS lesions were identified separately in each imaging sequence. Lesions identified in SWI were reevaluated for their iron content using the SWI filtered phase images.

Results: There were a variety of new lesion characteristics identified by SWI, and these were classified into six types. A total of 75 lesions were seen only with conventional imaging, 143 only with SWI, and 204 by both. From the iron quantification measurements, a moderate linear correlation between signal intensity and iron content (phase) was established.

Conclusion: The amount of iron deposition in the brain may serve as a surrogate biomarker for different MS lesion characteristics. SWI showed many lesions missed by conventional methods and six different lesion characteristics. SWI was particularly effective at recognizing the presence of iron in MS lesions and in the basal ganglia and pulvinar thalamus.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jmri.21676DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2650739PMC
March 2009

MRI retinovascular studies in humans: research in patients with diabetes.

NMR Biomed 2008 Nov;21(9):1003-12

Department of Ophthalmology, Henry Ford Health System, Detroit, MI 48202, USA.

Purpose: To review existing applications of MRI for detecting blood-retinal barrier (BRB) damage and retinal oxygenation response abnormalities in patients with diabetes and highlight new information available from such applications.

Methods: BRB studies were accomplished using dynamic contrast-enhanced MRI, and the retinal oxygenation response studies were accomplished by monitoring changes in the MRI signal associated with hyperoxic provocation. Participants were patients with diabetes and macular edema, with either no detectable or mild to moderate background retinopathy, as well as non-diabetic individuals of similar age (controls). Single-slice FLASH images were obtained using a Siemens Sonata, 1.5 T together with a Siemens 'Loop Small' surface coil fixed in place over the eye. Time-dependent changes in image contrast in the pre-retinal vitreous were quantified, and differences between patients and controls were assessed statistically.

Results: The BRB breakdown studies showed a significant difference in the temporal evolution of the MRI signal enhancement post-contrast injection between the controls and the patients with diabetic macular edema. The retinal oxygenation studies revealed a supernormal oxygenation response in the pre-retinal vitreous in patients with diabetes who had no evidence of retinopathy, as well as in patients with background diabetic retinopathy. A nasal-temporal asymmetry in the evolution of retinal oxygenation response was found in patients with diabetes that was not present in healthy subjects.

Conclusions: These studies show that subtle differences in retinovascular function between patients with diabetes and non-diabetic individuals, including changes that occur in advance of the clinical appearance of diabetic retinopathy, can be detected with MRI. These results, together with previous extensive preclinical data, establish MRI as a powerful non-invasive method for measuring spatial and temporal changes in the same key retinovascular metrics in both animals and humans. Wide application of these techniques for diagnosis and evaluation of treatment efficacy in a variety of human retinopathies, including diabetic retinopathy, is expected.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/nbm.1314DOI Listing
November 2008

MR susceptibility weighted imaging (SWI) complements conventional contrast enhanced T1 weighted MRI in characterizing brain abnormalities of Sturge-Weber Syndrome.

J Magn Reson Imaging 2008 Aug;28(2):300-7

Department of Radiology, Wayne State University, Detroit, Michigan 48201, USA.

Purpose: To evaluate the efficacy of susceptibility weighted imaging (SWI) in comparison to standard T1 weighted postgadolinium contrast (T1-Gd) MRI in patients with Sturge-Weber Syndrome (SWS).

Materials And Methods: Twelve children (mean age, 5.6 years) with the diagnosis of SWS and unilateral hemispheric involvement were recruited prospectively and examined with high resolution three dimensional SWI and conventional T1-Gd. Both SWI and T1-Gd images were evaluated using a four-grade scoring system according to six types of imaging findings (enlargement of transmedullary veins, periventricular veins, and choroid plexus, as well as leptomeningeal abnormality, cortical gyriform abnormality, and gray matter/white matter junctional abnormality). The scores of SWI versus T1-Gd images were then compared for each type of abnormality.

Results: SWI was superior to T1-Gd in identifying the enlarged transmedullary veins (P = 0.0020), abnormal periventricular veins (P = 0.0078), cortical gyriform abnormalities (P = 0.0020), and gray matter/white matter junction abnormalities (P = 0.0078). Conversely, T1-Gd was better than SWI in identifying enlarged choroid plexus (P = 0.0050) and leptomeningeal abnormalities (P = 0.0050).

Conclusion: SWI can provide useful and unique information complementary to conventional contrast enhanced T1 weighted MRI for characterizing SWS. Therefore, SWI should be integrated into routine clinical MRI protocols for suspected SWS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jmri.21435DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2678730PMC
August 2008

Aerosol delivery in ventilated newborn pigs: an MRI evaluation.

Pediatr Res 2008 Aug;64(2):159-64

Department of Pediatrics, Children's Hospital of Michigan, 4H42, Detroit, MI 48201, USA.

Pulmonary deposition of inhaled drugs in ventilated neonates has not been studied in vivo. The objective of this study was to evaluate pulmonary delivery of gadopentetate dimeglumine (Gd-DTPA) following nebulization in ventilated piglets using magnetic resonance imaging. Seven ventilated piglets (5 +/- 2 d old, weight 1.8 +/- 0.5 kg) were scanned in the Bruker/Siemens 4T magnetic resonance scanner using T1 weighted spin-echo sequence. Aerosols of Gd-DTPA were generated continuously using the MiniHeart jet nebulizer. Breath-hold coronal images were obtained before and every 10 min during aerosolized Gd-DTPA for 90 min. Signal intensity (SI) changes over the lungs, kidneys, liver, skeletal muscle, and heart were evaluated. A significant increase in SI was observed in the lungs, kidney, and liver at 10, 20, and 40 min respectively after start of aerosol. At the end of 90 min, the SI increased by 95%, 101%, and 426% over the right lung, left lung, and kidney, respectively. A much smaller increase in SI was observed over the liver. In conclusion, we have demonstrated effective pulmonary aerosol delivery within 10 min of contrast nebulization in ventilated piglets. Contrast visualization in the kidneys within 20 min of aerosol initiation reflects alveolar absorption, glomerular filtration and renal concentration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1203/PDR.0b013e3181761841DOI Listing
August 2008

Long-term study of brain 1H-MRS study in multiple sclerosis: effect of glatiramer acetate therapy on axonal metabolic function and feasibility of long-Term H-MRS monitoring in multiple sclerosis.

J Neuroimaging 2008 Jul;18(3):314-9

Multiple Sclerosis Clinical Research Center, Department of Neurology, The Detroit Medical Center, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.

Glatiramer acetate (GA) has several putative mechanisms of action with the potential of limiting sublethal axonal injury in the central nervous system (CNS). Brain proton magnetic resonance spectroscopy ((1)H-MRS) allows in vivo examination of axonal integrity by quantifying the neuronal marker N-acetylaspartate (NAA), often expressed as a ratio to creatine (Cr). We showed that treatment with GA led to improvement in NAA/Cr over a 2-year period. We now report the results of this ongoing study after 4 years of annual brain (1)H-MRS examinations. Compared to baseline, at year 4, patients receiving continuous GA therapy showed a 12.7% increase in NAA/Cr and (P= .03) in the multivoxel brain volume of interest (VOI) studied and by 9.6% (P= .04) in the normal-appearing white matter within the VOI. Three patients in the control group who began therapy with GA during the course of the study showed similar increases in NAA/Cr after the first year of therapy. These data support the long-term effect of GA on maintaining axonal metabolic function and protection from sublethal injury as well as the feasibility of employing brain (1)H-MRS in long-term investigative studies in MS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1552-6569.2007.00206.xDOI Listing
July 2008

Acute transverse myelitis with normal brain MRI : long-term risk of MS.

J Neurol 2008 Jan 20;255(1):89-93. Epub 2007 Dec 20.

Multiple Sclerosis Center, Dept. of Neurology, Wayne State University School of Medicine, Detroit, MI, USA.

Objective: To investigate the long-term risk of developing MS in patients presenting with acute transverse myelitis (ATM) and normal brain MRI scans at onset.

Methods: We studied 58 ATM patients with normal brain MRI at presentation for up to 5 years with serial neurologic and imaging studies. All patients underwent CSF analysis at onset which was defined positive if two or more IgG oligoclonal bands and/or elevated IgG index were present. Brain and spinal cord MRI scans were obtained every 6 months for the first 2 years, and annually thereafter unless the patient experienced a second neurologic attack different from the initial episode to confirm CDMS or there was demonstration of MRI lesions confirming dissemination in time and space to fulfill McDonald imaging criteria to diagnose MS.

Results: Seventeen of 58 (29%) patients developed MS of which 7 (41%) patients developed CDMS and 10 (59%) developed MS using McDonald Imaging Criteria. Mean time to CDMS by a second clinical attack was 11. 1 months compared to 19. 2 months by MRI lesions (P = 0. 03). None of the patients developed MS after 24 months of onset. All 17 patients who developed MS had positive CSF although 15 patients who had positive CSF did not develop MS during the 5 years of follow-up.

Conclusions: The majority of patients with ATM and normal brain MRI do not develop MS after 5 years of follow-up confirming the relatively low risk compared to patients with abnormal brain MRI scans. CSF is helpful in distinguishing patients more likely to develop MS. Compared to clinical attacks, serial imaging may not lead to an earlier diagnosis in ATM patients with normal brain MRI.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00415-007-0686-5DOI Listing
January 2008

New algorithm for quantifying vascular changes in dynamic contrast-enhanced MRI independent of absolute T1 values.

Magn Reson Med 2007 Sep;58(3):463-72

MRI Research Facility, Department of Radiology, Wayne State University, Detroit, Michigan 48201, USA.

In this work, we present a new method for predicting changes in tumor vascularity using only one flip angle in dynamic contrast-enhanced (DCE) imaging. The usual DCE approach finds the tissue initial T1 value T1(0) prior to injection of a contrast agent. We propose finding changes in the tissue contrast agent uptake characteristics pre- and postdrug treatment by fixing T1(0). Using both simulations and imaging pre- and postadministration of caffeine, we find that the relative change (NR50) in the median of the cumulative distribution (R50) is almost independent of T1(0). Fixing T1(0) leads to a concentration curve c(t) more robust to the presence of noise than calculating T1(0). Consequently, the NR50 for the tumor remains roughly the same as the ideal NR50 when T1(0) is exactly known. Further, variations in eating habits are shown to create significant changes in the R50 response for both liver and muscle. In conclusion, analyzing data with fixed T1(0) leads to a more stable measure of changes in NR50 and does not require knowledge of T1(0). Both caffeine and eating introduce major changes in blood flow that can significantly modify the NR50 and lead to incorrect conclusions regarding drug treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mrm.21358DOI Listing
September 2007