Although lockdown of the industrial and transport sector and stay at home advisories to counter the COVID-19 pandemic have shown that the air quality has improved during this time, very little is known about the role of ambient air pollutants and meteorology in facilitating its transmission. This paper presents the findings from a study that was conducted to evaluate whether air quality index (AQI), three primary pollutants (PM 2.5 , PM 10 and CO), Ground level ozone (O 3 ) and three meteorological variables (temperature, relative humidity, wind speed) have promoted the COVID-19 transmission in five megacities of India. The results show significant correlation of PM 2.5 , PM 10 , CO, O 3 concentrations, AQI and meteorological parameters with the confirmed cases and deaths during the lockdown period. Among the meteorological variables considered, temperature strongly correlated with the COVID-19 cases and deaths during the lockdown ( ) and unlock period ( ). Among the pollutants, ozone, and among the meteorological variables, temperature, explained the highest variability, up to 34% and 30% respectively, for COVID-19 confirmed cases and deaths. AQI was not a significant parameter for explaining the variations in confirmed and death cases. WS and RH could explain 10–11% and 4–6% variations of COVID-19 cases. A GLM model could explain 74% and 35% variability for confirmed cases and deaths during the lockdown and 66% and 19% variability during the unlock period. The results suggest that meteorological parameters may have promoted the COVID-19 incidences, especially the confirmed cases. Our findings may encourage future studies to explore more about the role of ambient air pollutants and meteorology on transmission of COVID-19 and similar infectious diseases.

Heat-shock proteins (HSPs) are rapidly synthesized in cells in response to various cytotoxic agents. Although several stress proteins are actively involved in the gentamicin-induced renal damages, the possible role of HSP47 in this condition is not yet clear. In this study, the expression of HSP47 in the gentamicin nephrotoxicity was examined by immunohistochemistry. Twenty male Wistar rats were sacrificed at day 0, 3, 7, 14 and 28 after subcutaneous injection of gentamicin. Gentamicin treatment causes tubular necrosis at day 3, followed by tubular regenerative changes and interstitial fibrosis, which was most prominent at day 14. The renal structures returned to almost normal architectures at day 28. By immunohistochemistry, HSP47 was weakly expressed in most of the glomeruli and occasionally in interstitial cells in the control rat kidneys. In contrast, strong immunostaining for HSP47 was noted in the tubular epithelial cells and interstitial cells in gentamicin treated rat kidneys, and strongest staining was observed at day 7. The immunostaining for HSP47 then gradually decreased, and returned to the normal level at day 28. In the whole experimental period staining pattern of HSP47 in the glomeruli was not changed. In addition, phenotypically altered tubulointerstitial cells including regenerative tubular epithelial cells (immuno-positive for vimentin) and interstitial cells (immuno-positive for alpha-smooth muscle actin) were found in gentamicin nephrotoxicity. Expression of type III collagen increased in the areas of interstitial fibrosis. By double immunostaining, the regenerated and phenotypically altered tubulointerstitial cells were found to express HSP47 in and around interstitial fibrosis. It is concluded that overexpression of HSP47 by phenotypically altered renal cells might play a significant role in the development of gentamicin nephrotoxicity.

Marek's disease (MD) is a lymph proliferative disease of chickens, characterized by progressive emaciation, morbidity and mortality. The causative agent is a cell associated oncogenic alpha-herpes virus. This study investigated an outbreak of MD in a pullet farm (N=2200) of Ramu Upazilla, Cox's bazaar during May 2016 vaccinated against MD. The infectivity was reported on day 45 of age. Birds (N=10) submitted to diagnose disease at necropsy in the Department of Pathology, Bangladesh Agricultural University showed prominent keel bone, asymmetric progressive paralysis of one or both of the legs and wings. At necropsy, the skeletal muscle appeared thinner and there was enlargement of liver, spleen, kidney and sciatic nerve. Impression smears prepared from the liver showed huge infiltration of lymphocytes. Sections of heart, lungs, liver, kidney, nerve, skin and spleen were stained with hematoxylin and eosin showed wide spread infiltrations and accumulation of lymphocytes. Lymphocytic infiltration was seen in the skin, nerves and all visceral organs and showed combined infectivity due to visceral and classical forms. The etiology of MD was confirmed by using polymerase chain reaction (PCR) targeting fragment of Meq gene of very virulent plus or very virulent MDV1. Results of PCR showed amplification of 317bp fragment of Meq gene suggestive for infectivity due to MDV1GA (Md/5) strain. It requires isolating viruses in culture to test further for its virulence and pathotype in vivo. Sequencing and phylogenetic analysis of Meq gene may unveil the pathotype of the virus involved.

This study investigated outbreaks of Foot and Mouth Disease (FMD) in cattle in Pabna district, Bangladesh, during August-September 2015. Out of 100 cattle, 45 were infected with FMD virus, of which five young and two adult cattle died and the postmortem changes in internal organs were recorded. Oral tissue samples from infected cattle (n = 20) of four Upazillas (Sub-district) of Pabna district were collected for viral RNA extraction and serotype identification using reverse transcriptase polymerase chain reaction (RT-PCR). Gross and histopathological changes in oral, pedal and mammary tissues were typical of FMD. Characteristics lesion of 'tiger heart disease' was seen in heart muscle of young and adult cattle. There was thickening of interlobular septum of lungs and characteristics of interstitial pneumonia. The uniplex and multiplex RT-PCR detected FMD viruses (430 bp) and FMD viral serotypes "O" (402 bp) and "Asia 1" (292 bp). Cattle of Sujanagar, Chatmahar and Isshardi Upazillas of Pabna district were infected with FMD viral serotype "O" and responsible for mortality of three young and two adult cattle. FMD viral serotype "Asia 1" causing death of two young cattle at Pabna Sadar. The fragment (485 bp) of Vp1 gene of FMD viral serotype "O" sequenced showed mutation in main antigenic sites. The phylogenetic analysis carried out with the Vp1 gene of FMD viral serotype "O" showed the viruses belonging to ME-SA topotype. The death of young and adult cattle was probably due to cardiac and/or respiratory failure. The adapted RT-PCR protocol can be used in practice for detecting FMD viruses and its serotyping. Larger samples sizes require investigating to identify existing FMD viral serotypes and topotypes in order to design future preventive strategies.

BackgroundThe Covid-19 pandemic began in China in December 2019. India is the second most affected country, as of November 2020 with more than 8.5million cases. Covid-19 infection primarily involves the lung with severity of illness varying from influenza-like illness to acute respiratory distress syndrome. Other organs have also found to be variably affected. Studies evaluating the histopathological changes of Covid-19 are critical in providing a better understanding of the disease pathophysiology and guiding treatment. Minimally invasive biopsy techniques (MITS/B) provide an easy and suitable alternative to complete autopsies. In this prospective single center study we present the histopathological examination of 37 patients who died with complications of Covid-19.MethodsThis was an observational study conducted in the Intensive Care Unit of JPN Trauma Centre AIIMS. A total of 37 patients who died of Covid-19 were enrolled in the study. Post-mortem percutaneous biopsies were taken by the help of surface landmarking/ultrasonography guidance from lung, heart, liver, and kidneys; after obtaining ethical consent. The biopsy samples were then stained with haematoxylin and eosin stain. Immunohistochemistry (IHC) was performed using CD61 and CD163 in all lung cores. SARS-CoV-2 virus was detected using IHC with primary antibodies in selected samples. Details regarding demographics, clinical parameters, hospital course, treatment details, and laboratory investigations were also collected for clinical correlation.ResultsA total of 37 patients underwent post-mortem minimally invasive tissue sampling. Mean age of the patients was 48.7years and 59.5% of them were males. Respiratory failure was the most common complication seen in 97.3%. Lung histopathology showed acute lung injury and diffuse alveolar damage in 78% patients. Associated bronchopneumonia was seen in 37.5% patients and scattered microthrombi were visualised in 21% patients. Immunostaining with CD61 and CD163 highlighted megakaryocytes, and increased macrophages in all samples. Immunopositivity for SARS-CoV-2 was observed in Type II pneumocytes. Acute tubular injury with epithelial vacuolization was seen in 46% of the renal biopsies but none of them showed evidence of microvascular thrombosis. 71% of the liver tissue cores showed evidence of Kupfer cell hyperplasia. 27.5% had evidence of submassive hepatic necrosis and 14% had features of acute on chronic liver failure. All the heart biopsies showed non-specific features such as hypertrophy with nucleomegaly with no evidence of myocardial necrosis in any of the samples.ConclusionsThe most common finding in this cohort is the diffuse alveolar damage with demonstration of SARS-CoV-2 protein in the acute phase of DAD. Microvascular thrombi were rarely identified in the lung, liver and kidney. Substantial hepatocyte necrosis, hepatocyte degeneration, Kupffer cell hypertrophy, micro, and macrovesicular steatosis unrelated to microvascular thrombi suggests that liver might be a primary target of Covid-19. This study highlights the importance of MITS/B in better understanding the pathological changes associated with Covid-19.