Publications by authors named "Rachel Hoffmann"

12 Publications

  • Page 1 of 1

A (conditional) role for labdane-related diterpenoid natural products in rice stomatal closure.

New Phytol 2021 Jan 18. Epub 2021 Jan 18.

Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA, 50011, USA.

Rice (Oryza sativa) is the staple food for over half the world's population. Drought stress imposes major constraints on rice yields. Intriguingly, labdane-related diterpenoid (LRD) phytoalexins in maize (Zea mays) affect drought tolerance, as indicated by the increased susceptibility of an insertion mutant of the class II diterpene cyclase ZmCPS2/An2 that initiates such biosynthesis. Rice also produces LRD phytoalexins, utilizing OsCPS2 and OsCPS4 to initiate a complex metabolic network. For genetic studies of rice LRD biosynthesis the fast-growing Kitaake cultivar was selected for targeted mutagenesis via CRISPR/Cas9, with an initial focus on OsCPS2 and OsCPS4. The resulting cps2 and cps4 knockout lines were further crossed to create a cps2x4 double mutant. Both CPSs also were overexpressed. Strikingly, all of the cv Kitaake cps mutants exhibit significantly increased susceptibility to drought, which was associated with reduced stomatal closure that was evident even under well-watered conditions. However, CPS overexpression did not increase drought resistance, and cps mutants in other cultivars did not alter susceptibility to drought, although these also exhibited lesser effects on LRD production. The results suggest that LRDs may act as a regulatory switch that triggers stomatal closure in rice, which might reflect the role of these openings in microbial entry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/nph.17196DOI Listing
January 2021

The environmental impacts of palm oil in context.

Nat Plants 2020 12 7;6(12):1418-1426. Epub 2020 Dec 7.

Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway.

Delivering the Sustainable Development Goals (SDGs) requires balancing demands on land between agriculture (SDG 2) and biodiversity (SDG 15). The production of vegetable oils and, in particular, palm oil, illustrates these competing demands and trade-offs. Palm oil accounts for ~40% of the current global annual demand for vegetable oil as food, animal feed and fuel (210 Mt), but planted oil palm covers less than 5-5.5% of the total global oil crop area (approximately 425 Mha) due to oil palm's relatively high yields. Recent oil palm expansion in forested regions of Borneo, Sumatra and the Malay Peninsula, where >90% of global palm oil is produced, has led to substantial concern around oil palm's role in deforestation. Oil palm expansion's direct contribution to regional tropical deforestation varies widely, ranging from an estimated 3% in West Africa to 50% in Malaysian Borneo. Oil palm is also implicated in peatland draining and burning in Southeast Asia. Documented negative environmental impacts from such expansion include biodiversity declines, greenhouse gas emissions and air pollution. However, oil palm generally produces more oil per area than other oil crops, is often economically viable in sites unsuitable for most other crops and generates considerable wealth for at least some actors. Global demand for vegetable oils is projected to increase by 46% by 2050. Meeting this demand through additional expansion of oil palm versus other vegetable oil crops will lead to substantial differential effects on biodiversity, food security, climate change, land degradation and livelihoods. Our Review highlights that although substantial gaps remain in our understanding of the relationship between the environmental, socio-cultural and economic impacts of oil palm, and the scope, stringency and effectiveness of initiatives to address these, there has been little research into the impacts and trade-offs of other vegetable oil crops. Greater research attention needs to be given to investigating the impacts of palm oil production compared to alternatives for the trade-offs to be assessed at a global scale.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41477-020-00813-wDOI Listing
December 2020

Criteria for CITES species protection.

Science 2019 04 18;364(6437):247-248. Epub 2019 Apr 18.

Scientific Services, CITES Secretariat, Maison International de l'Environnement, CH-1219 Geneva, Switzerland.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/science.aax1266DOI Listing
April 2019

Use of Dapsone in the Treatment of Chronic Idiopathic and Autoimmune Urticaria.

JAMA Dermatol 2019 01;155(1):90-95

The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, New York.

Importance: The first-line treatment for patients with chronic spontaneous urticaria (CSU), which is divided into idiopathic and autoimmune subtypes, consists of H1-antihistamines. However, limited evidence guides the treatment of CSU after maximal therapy with antihistamines fails. Two randomized clinical trials suggest that dapsone may be a successful second-line therapy.

Objective: To evaluate the efficacy and safety of dapsone therapy in patients with CSU.

Design, Setting, And Participants: This retrospective medical record review included 79 patients with CSU treated with dapsone who presented to the tertiary care academic medical center at the New York University School of Medicine, New York, New York, from January 1, 2005, through April 15, 2017. Follow-up was completed on February 28, 2018. Data were analyzed from March 1 through May 31, 2018.

Exposures: Treatment with oral dapsone for CSU.

Main Outcomes And Measures: Efficacy of dapsone therapy for CSU was evaluated as improvement, complete response, and remission.

Results: Seventy-nine patients (65% women; mean [SD] age, 49.8 [16.1] years [range, 20-79 years]) were included in the analysis. Forty-five patients had chronic idiopathic urticaria and 34 had chronic autoimmune urticaria. Improvement in CSU was observed in 62 patients (78%) (36 [80%] with idiopathic and 26 [76%] with autoimmune disease) with dapsone. Mean (SD) time to improvement was 1.1 (1.0) months. A complete response was achieved in 29 (47%) of these 62 patients (16 [44%] with idiopathic and 13 [50%] with autoimmune disease). Mean (SD) time to complete response was 5.2 (5.2) months. Dapsone therapy was tapered in 21 patients after a mean (SD) of 2.4 (2.2) months and discontinued in 18. Ten patients experienced remission with no subsequent flares, even after dapsone therapy was discontinued with follow-up of 0.3 to 10.0 months. Sixteen patients experienced mild adverse effects. Two serious adverse effects were reported.

Conclusions And Relevance: Results of this study suggest that dapsone is a useful and well-tolerated second-line therapy for patients with CSU in whom antihistamines and other first-line agents have failed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1001/jamadermatol.2018.3715DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6439569PMC
January 2019

Genital ulcers in an immunocompromised man.

JAAD Case Rep 2018 Aug 14;4(7):619-621. Epub 2018 Jul 14.

The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, New York.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jdcr.2017.10.024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6070680PMC
August 2018

Biochemistry, Physiology, and Tissue Interactions of Contemporary Biodegradable Injectable Dermal Fillers.

Dermatol Surg 2018 11;44 Suppl 1:S19-S31

Department of Dermatology, University of California, San Francisco, San Francisco, California.

Background: Injectable dermal fillers are becoming increasingly popular for soft tissue augmentation and rejuvenation. Most contemporary biodegradable products are derived from hyaluronic acid, calcium hydroxylapatite, or poly-L-lactic acid. Achievement of desired cosmetic outcomes is largely dependent on selection of the optimal injectable product based on the chemical composition, the physiologic interactions with surrounding tissue, product longevity, and a thorough understanding of potential adverse reactions.

Objective: To review and describe the biochemistry, physiology, and tissue interactions of the most commonly used contemporary biodegradable dermal fillers.

Methods: A thorough review of the literature was performed with additional review of pertinent clinical cases and corresponding histopathology.

Results: This article provides a comprehensive review of the biochemistry, physiology, and potential tissue interactions of the most commonly used biodegradable dermal fillers. The underlying biochemical properties of each product and how they contribute to specific physiologic and adverse tissue reactions is described.

Conclusion: Understanding of the innate differences in the physical properties, and physiologic responses to soft tissue fillers allows clinicians to achieve desired aesthetic outcomes with fewer adverse events.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/DSS.0000000000001582DOI Listing
November 2018

Concentric targetoid scaly plaques in a patient with severe rheumatoid arthritis.

Int J Dermatol 2018 Aug 11;57(8):913-914. Epub 2018 Apr 11.

The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ijd.13991DOI Listing
August 2018

An immunosuppressed man with an isolated necrotic plaque on the chest.

JAAD Case Rep 2018 Mar 12;4(2):114-116. Epub 2018 Jan 12.

The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, New York.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jdcr.2017.02.025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5767909PMC
March 2018

Dermatology in Ghana: a retrospective review of skin disease at the Korle Bu Teaching Hospital Dermatology Clinic.

Pan Afr Med J 2017 3;26:125. Epub 2017 Mar 3.

The Ronald Perelman Department of Dermatology, New York University School of Medicine, USA.

Introduction: Ghana is currently developing its provision of dermatology services. Epidemiologic studies of the skin diseases seen by Ghanaian dermatologists are needed to guide these efforts. We aimed to describe the skin conditions seen by and management practices of Ghanaian dermatologists in a specialized clinic.

Methods: We conducted a chart review of new patients presenting to the Korle Bu Teaching Hospital dermatology clinic during 2014.

Results: Among the 529 patients studied, 700 discrete diagnoses were made. The most commonly diagnosed skin conditions were infections (24.6%) and dermatitis (24.6%); atopic dermatitis (8.4%), acne vulgaris (5.3%) and scabies (5.1%) were the most common specific diagnoses. Among infants, children, and adolescents, the most common diagnosis was atopic dermatitis (31.7%, 30.0%, and 14.9%, respectively). Acne vulgaris (12.0%) was the most common skin condition diagnosed in young adults. Irritant contact dermatitis (6.9%) was most common among adults. Lichen planus (9.9%) was the most commonly diagnosed skin condition in the senior population. Diagnoses made by dermatologists differed from the referral diagnosis documented by primary care providers for 65.8% of patients. The most frequently recommended treatments were antihistamines (47.8%) and topical steroids (38.4%). Only 18 diagnostic biopsies were performed.

Conclusion: Our study summarizes the skin diseases seen and management practices of Ghanaian dermatologists in a specialized clinic at a large public teaching hospital. The results of this study can help to guide future dermatology education and development efforts in Ghana.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.11604/pamj.2017.26.125.10954DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5429409PMC
June 2017

Acral keratoses and squamous-cell carcinomas likely associated with arsenic exposure.

Dermatol Online J 2016 Dec 15;22(12). Epub 2016 Dec 15.

Ronald O. Perelman Department of Dermatology, NYU School of Medicine, NYU Langone Medical Center.

Chronic arsenic exposure is known to inducepunctate keratoses with an increased risk ofprimary squamous-cell carcinoma. Drinking wateris currently the major source of arsenic exposureworldwide and is considered one of the mostsubstantial environmental carcinogens. We describethe case of a 61-year-old Hungarian woman withscattered, acral, hyperkeratotic papules and a historyof five palmoplantar squamous-cell carcinomasas well as two other extremity non-melanomaskin cancers. Prior to immigration, she had livedin a county of Southern Hungary that is known tohave elevated concentrations of inorganic arsenicin the drinking water above the World HealthOrganization's current maximum threshold forsafety. To date, this report is the first to describethe phenomenon of palmoplantar squamouscellcarcinomas in a patient from this region andunderscores the importance of vigilant screening inthose individuals who have spent substantial time inhigh-risk regions internationally and domestically.
View Article and Find Full Text PDF

Download full-text PDF

Source
December 2016

Luciferase inhibition by a novel naphthoquinone.

J Photochem Photobiol B 2012 Feb 8;107:55-64. Epub 2011 Dec 8.

Department of Chemistry and Biochemistry, The University of Tulsa, Tulsa, OK 74104, USA.

The novel naphthoquinone 12,13-dihydro-N-methyl-6,11,13-trioxo-5H-benzo[4,5]cyclohepta[1,2-b]naphthalen-5,12-imine (hereafter called TU100) was created as a potential chemotherapeutic agent. Previous work showed it is an irreversible inhibitor of type I and II topoisomerases that alkylates specific enzyme thiols. While analyzing the effect of TU100 on cancer cells, we discovered it is a potent inhibitor of luciferase derived from both Photinus pyralis (fireflies) and Renilla reniformis (sea pansy). Pre-incubation experiments showed that TU100 does not irreversibly inactivate luciferase, indicating its mechanism is different from that observed with topoisomerases. Firefly luciferase generates light using ATP and luciferin as substrates (bioluminescence). An examination of TU100 inhibition at varying substrate concentrations revealed the drug is uncompetitive with respect to ATP and competitive with respect to luciferin. The TU100 binding constant (K(I)) is 2.5±0.7 μM as determined by Dixon plot analysis. These data suggest TU100 specifically binds the luciferase-ATP complex and prevents its interaction with luciferin. Given the novel structure of TU100, unique mechanism of action, and ability to target luciferase from different species, these results identify TU100 as an important new reagent for investigating and regulating bioluminescent enzymes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jphotobiol.2011.11.008DOI Listing
February 2012

Serotonin transporter gene (5-HTTLPR) polymorphisms are associated with emotional modulation of pain but not emotional modulation of spinal nociception.

Biol Psychol 2011 Mar 1;86(3):360-9. Epub 2011 Feb 1.

Department of Psychology, The University of Tulsa, Tulsa, OK 74104, USA.

The short allele of the serotonin transporter gene (5-HTTLPR) is associated with greater negative emotionality. Given that emotion modulates pain, short allele carriers (s-carriers) may also demonstrate altered pain modulation. The present study used a well-validated emotional picture-viewing paradigm to modulate pain and the nociceptive flexion reflex (NFR, a measure of spinal nociception) in 144 healthy genotyped participants. As expected, pain/NFR responses were largest during unpleasant pictures and smallest during pleasant pictures. However, relative to l/l-carriers, s-carriers demonstrated greater pain inhibition during pleasant pictures and greater pain facilitation during unpleasant pictures. Neither emotional modulation of NFR nor NFR threshold was associated with 5-HTTLPR polymorphisms. Results also indicated that men who were s-carriers had a higher pain threshold and tolerance than other participants. Taken together, our results indicate 5-HTTLPR polymorphisms may influence pain modulation at the supraspinal (not spinal) level; however, the influence on pain sensitivity may be sex-specific.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biopsycho.2011.01.008DOI Listing
March 2011