Publications by authors named "K Byranahalli Sunilkumar"

18 Publications

Maternal and fetal vascular lesions of malperfusion in the placentas associated with fetal and neonatal death: results of a prospective observational study.

Am J Obstet Gynecol 2021 Jun 8. Epub 2021 Jun 8.

Department of Obstetrics and Gynecology, Columbia University, New York, NY.

Background: Fetal death is one of the major adverse pregnancy outcomes and is common in low- and middle-income countries. Placental lesions may play an important role in the etiology of fetal and neonatal deaths. Previous research relating placental lesions to fetal death causation was hindered by a lack of agreement on a placental classification scheme. The Amsterdam consensus statement that was published in 2016 focused its attention on malperfusions in the maternal and fetal placental circulations.

Objective: This study aimed to investigate the relationships of placental maternal and fetal vascular malperfusions in fetal and neonatal deaths, focusing on the most important maternal clinical conditions in the pathway to fetal and neonatal deaths, such as maternal hypertension, antepartum hemorrhage, and decreased fetal growth.

Study Design: This was a prospective, observational cohort study conducted at 2 Asian sites. The data collected included clinical history, gross and histologic evaluations of the placenta, and several other investigations and were used to determine the cause of death. The placenta was evaluated at both sites using the Amsterdam consensus framework. We estimated the risk of placental maternal and fetal vascular malperfusions in fetal and neonatal deaths.

Results: Between July 2018 and January 2020 in India and Pakistan, 1633 women with placentas available for the study provided consent. Of these women, 814 had fetal deaths, 618 had preterm live births and subsequent neonatal deaths, and 201 had term live births. The prevalence of maternal vascular malperfusion was higher in the placentas associated with fetal deaths (58.4%) and preterm neonatal deaths (31.1%) than in the placentas associated with term live births (15.4%). Adjusting for site, maternal vascular malperfusion had a relative risk of 3.88 (95% confidence interval, 2.70-5.59) in fetal deaths vs term live births and a relative risk of 2.07 (95% confidence interval, 1.41-3.02) in preterm neonatal deaths vs term live births. Infarcts and distal villous hypoplasia were the most common histologic components of maternal vascular malperfusion. Compared with maternal vascular malperfusion (58.4%), fetal vascular malperfusion was less common in the placentas associated with fetal deaths (19.0%). However, there were higher frequencies of fetal vascular malperfusion in the placentas associated with fetal deaths (19.0%) than in placentas associated with neonatal deaths (8.3%) or term live birth (5.0%). Adjusting for site, fetal vascular malperfusion had a relative risk of 4.09 (95% confidence interval, 2.15-7.75) in fetal deaths vs term live births and a relative risk of 1.77 (95% confidence interval, 0.90-3.49) in preterm neonatal deaths vs term live births. Furthermore, there was a higher incidence of maternal vascular malperfusion in cases of maternal hypertension (71.4%), small for gestational age (69.9%), and antepartum hemorrhage (59.1%) than in cases of fetal deaths with none of these conditions (43.3%). There was no significant difference in the occurrence of fetal vascular malperfusion in the 4 clinical categories.

Conclusion: Histologic examination of the placenta, especially for malperfusion disorders, is crucial in elucidating pathways to fetal and neonatal deaths in preterm infants. In particular, focusing on placental maternal and fetal vascular malperfusions during pregnancy is a means to identify fetuses at risk of fetal death and is an important strategy to reduce the risk of fetal death early delivery. We hope that the increased risk of fetal and neonatal deaths in these pregnancies can be reduced by the development of an intervention that reduces the likelihood of developing maternal and fetal vascular malperfusion.
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http://dx.doi.org/10.1016/j.ajog.2021.06.001DOI Listing
June 2021

Enhanced optical pulse broadening in free-space optical links due to the radiative effects of atmospheric aerosols.

Opt Express 2021 Jan;29(2):865-876

Propagation through turbulent media produces complex amplitude fluctuations and temporal spreading of narrow optical pulses. Light-absorbing aerosols present in the atmospheric transmission path will perturb the refractive index structure parameter (Cn2) through atmospheric heating. The consequent enhancement in broadening and attenuation of ultrashort (femtosecond) optical pulses has been calculated by combining multi-satellite observations, radiosonde profiles and computational radiative transfer. It is shown that narrower optical pulses are more vulnerable to aerosol-induced impairments while broader pulses are more resilient, notwithstanding three to four orders of enhanced optical scintillation.
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http://dx.doi.org/10.1364/OE.409794DOI Listing
January 2021

assessment of anti-inflammatory and anti-arthritic effects of (Desv.) Danser accessions collected from six different hosts.

Saudi J Biol Sci 2020 Dec 15;27(12):3301-3306. Epub 2020 Oct 15.

Department of Clinical Pharmacology, College of Medicine, Soonchunhyang University, Cheonan, Republic of Korea.

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http://dx.doi.org/10.1016/j.sjbs.2020.10.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7715451PMC
December 2020

Collagenofibrotic glomerulopathy: A case of glomerular deposition disease in the Indian subcontinent and review of the literature.

Saudi J Kidney Dis Transpl 2020 May-Jun;31(3):681-686

Department of Pathology, Apollo Hospitals, Chennai, Tamil Nadu, India.

Collagenofibrotic glomerulopathy (CG) is a rare renal disease with unknown etiology, defined by deposition of Type III collagen fibers in the subendothelial space and mesangium seen on supported by electron microscopy. There are merely 19 cases reported in the literature from the Indian subcontinent. Herein, we present a case report of CG from the Indian subcontinent and review its literature mainly focusing on histopathological findings.
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http://dx.doi.org/10.4103/1319-2442.289454DOI Listing
June 2021

Entanglement of near-surface optical turbulence to atmospheric boundary layer dynamics and particulate concentration: implications for optical wireless communication systems.

Appl Opt 2020 Feb;59(5):1471-1483

Localized reduction in optical turbulence due to enhanced atmospheric heating caused by the solar absorption of aerosol black carbon (BC) is reported. Immediate response of atmospheric turbulence to BC-induced atmospheric warming strongly depends on the available solar radiation (time of the day), BC concentration, and atmospheric boundary layer dynamics. Besides the significant climate implications of a reduction in turbulence kinetic energy, a large reduction in the refractive index structure parameter (2) resulting from BC-induced warming would affect the atmospheric propagation of laser beams. Interestingly, aerosols contribute significantly (up to 25%) to the signal deterioration in optical wireless communication systems during convectively stable atmospheric conditions when higher signal-to-noise ratios are expected otherwise due to the reduced thermal convection. Competing effects of the fractional contributions of aerosol extinction and scintillations on beam attenuation are reported; daytime being largely dominated by scintillation effects while the nighttime being dependent on the ambient aerosol concentration as well. We put forward the entanglement of optical turbulence to aerosol concentration, atmospheric boundary layer dynamics, and surface-reaching solar radiation, and discuss the possible implications for optical propagation.
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http://dx.doi.org/10.1364/AO.381737DOI Listing
February 2020
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