Genomic surveillance of SARS-CoV-2 by sequencing the RBD region using Sanger sequencing from North Kerala.

Next Generation Sequencing (NGS) is the gold standard for the detection of new variants of SARS-CoV-2 including those which have immune escape properties, high infectivity, and variable severity. This test is helpful in genomic surveillance, for planning appropriate and timely public health interventions. But labs with NGS facilities are not available in small or medium research settings due to the high cost of setting up such a facility. Transportation of samples from many places to few centers for NGS testing also produces delays due to transportation and sample overload leading in turn to delays in patient management and community interventions. This becomes more important for patients traveling from hotspot regions or those suspected of harboring a new variant. Another major issue is the high cost of NGS-based tests. Thus, it may not be a good option for an economically viable surveillance program requiring immediate result generation and patient follow-up. The current study used a cost-effective facility which can be set up in a common research lab and which is replicable in similar centers with expertise in Sanger nucleotide sequencing. More samples can be processed at a time and can generate the results in a maximum of 2 days (1 day for a 24 h working lab). We analyzed the nucleotide sequence of the Receptor Binding Domain (RBD) region of SARS-CoV-2 by the Sanger sequencing using in-house developed methods. The SARS-CoV-2 variant surveillance was done during the period of March 2021 to May 2022 in the Northern region of Kerala, a state in India with a population of 36.4 million, for implementing appropriate timely interventions. Our findings broadly agree with those from elsewhere in India and other countries during the period.

Enterochromaffin Cells and Mast Cells in Acute Appendicitis.

Background and Objective Serotonin levels are increased in acute appendicitis. We investigated the possible source of this increase. The aim of this study was to compare the distribution and density of epithelial and nonepithelial enterochromaffin (EC) cells as well as numbers of degranulated and nondegranulated mast cells in different layers of normal appendices and acute appendicitis. Methods Sections from 15 cases of acute appendicitis and 10 cases where the appendix was morphologically normal were stained with Hematoxylin & Eosin, Toluidine blue, and immunohistochemically for chromogranin and CD-117. EC cells stained by chromogranin were counted per crypt and extraepithelial EC cells counted and expressed as cells per unit area (mm 2 ). Mast cells stained by Toluidine blue and CD-117 were counted in lamina propria, submucosa, and muscle layers. The difference between Toluidine blue and CD117 stained mast cells was taken to be an estimate of degranulated cells. The cell counts were expressed per unit area (mm 2 ) as well as per cross-sectional area of the appendix. Results There was no statistically significant difference in epithelial and extraepithelial EC cells between acute appendicitis and normal appendix. Estimated mast cell degranulation as indicated by mast cell counts per cross-sectional area is greatly increased in acute appendicitis when compared with normal. Conclusion Degranulated mast cells rather than EC cells may be the main source of raised serotonin in acute appendicitis.

Autopsy-based morphometric study of coronary atherosclerosis in young adults.

Background & objectives: The burden of cardiovascular diseases is high in Kerala, India, and a considerable proportion of these occur in young people. The objective of this study was to estimate the severity of atherosclerosis in autopsies done for accidental and suicidal deaths in victims below 40 yr of age. Methods: Coronary arteries from 77 autopsies done for unnatural deaths in a population below 40 yr were graded, and the degree of stenosis, intimal thickness index (ITI) and the intima-media ratio (IMR) were measured. Results: There were 65 males and 12 females in the sample. The American Heart Association (AHA) type 3-6 (pathological intimal thickening) was seen in 55.4 per cent [95% confidence interval (CI): 42.5-67.7%] of males and 25 per cent (95% CI: 5.5-57.2%) of females and advanced lesions (type 4-6) in 44.6 per cent (95% CI: 32.3-57.5%) of males and 8.3 per cent (95% CI: 0.2-38.5%) of females. Types 5 or 6 lesions were seen in 32.2 per cent (95% CI: 21.2-45.1%) of males. The mean stenosis was 57.3 per cent in males and 40.6 per cent in females. More than 40 per cent stenosis was seen in 76.6 per cent cases, more than 50 per cent in 54.5 per cent cases and more than 75 per cent stenosis in 14.3 per of the sample. The mean ITI (MIT) was 1.85 and the mean IMR was 4.11. The degree of stenosis, MIT and IMR were significantly associated with male sex, overweight and smoking. Interpretation & conclusions: Morphometric data showed that the degree of atherosclerotic narrowing of coronary arteries in young non-diseased population was high. It portends a danger to the community unless preventive measures are taken up.

Bilineage T-lymphoblastic/myeloid extramedullary blast crisis in chronic myelogenous leukemia.

The blast crisis of chronic myelogenous leukemia (CML) can be hematological or extramedullary. About 25% of these cases fulfill the criteria for mixed phenotype acute leukemia. We here report a case of a second blast crisis of CML which was extramedullary and was immunophenotypically bilineage T/myeloid.

Diagnosis of leiomyosarcoma of colon.

Leiomyosarcomas of colon are rare tumors accounting for less than 1% of cases which are often misdiagnosed and confused with gastrointestinal stromal tumor (GIST). We report a case of 54-year-old male presenting with abdominal pain with computer tomography (CT) showing a retroperitoneal mass. He underwent laparotomy and surgical excision of mass was done. On pathological examination, microscopy was suggestive of GIST, but immunohistochemistry was positive for desmin and ultimately this case was diagnosed as leiomyosarcoma.

Comparative efficacy of double-stranded RNAs targeting WSSV structural and nonstructural genes in controlling viral multiplication in Penaeus monodon.

RNA interference (RNAi) is a potential strategy to control shrimp viral diseases, including the white spot disease caused by White Spot Syndrome Virus (WSSV). Selection of genes for targeting is an important criterion. We have compared the efficacy of dsRNAs targeting structural (vp28 and vp281) and nonstructural genes (rr1 and dnapol) of WSSV in controlling viral multiplication in Penaeus monodon. Targeting the rr1 and vp28 genes provided better protection (93.3% and 90% survival respectively) compared to vp281 and dnapol in experimentally infected shrimp. Temporal transcriptional analysis of the corresponding genes and PCR-based diagnosis of WSSV in samples collected at different time points in the experiment supported this observation, thereby indicating that targeting a combination of rr1 and vp28 would be effective in limiting WSSV multiplication.

Cutaneous manifestations of chikungunya during a recent epidemic in Calicut, north Kerala, south India.

BACKGROUND: There was a recent epidemic of chikungunya (CKG) in Calicut and other northern districts of Kerala, South India, affecting thousands of people. AIMS: To study the cutaneous manifestations of CKG and to have a serological and histopathological correlation. METHODS: A total of 162 patients (63 males and 99 females) with cutaneous manifestations of CKG were enrolled in the study and serological confirmation was done with capture IgM ELISA for CKG. Skin biopsy was done in all representative cases. RESULTS: Cutaneous manifestations were found more in females. There were 23 children, the youngest being 39 days old. Generalized erythematous macular rash was the most common finding. Vesicles and bullae were also common especially in infants. Localized erythema of the nose and pinnae, erythema and swelling of the pre existing scars and striae and toxic epidermal necrolysis-like lesions sparing mucosae were the other interesting findings. Different types of pigmentation were observed with a striking nose pigmentation in a large number of patients, by looking at which even a retrospective diagnosis of CKG could be made. Hence we suggest this peculiar pigmentation may be called "chik sign". There was flare up of existing dermatoses like psoriasis, lichen planus and unmasking of Hansen's disease with type 1 reaction. Serological tests were positive in 97%. Some hitherto unreported histopathologic findings like melanophages in the erythematous rashes were observed. CONCLUSION: A spectrum of cutaneous manifestations of CKG with a wide variety of unusual presentations with confirmed serological and histopathological evidence was encountered.

Acute eosinophilic appendicitis and the significance of eosinophil - Edema lesion.

Eight cases of a histological entity that we name 'acute eosinophilic appendicitis' (AEA) are described and compared with classical acute appendicitis and appendices, which turned out to be normal after emergency appendicectomy. These 8 cases formed part of a dataset of 128 emergency appendicectomies, which also included 78 cases of classical acute appendicitis and 42 cases of normal appendix. The clinical and pathological variables were compared between these three. Acute eosinophilic appendicitis is characterized by acute presentation and a grossly inflamed appendix, but with absence of neutrophils in the muscle layer. The histological hallmark of the entity is eosinophil infiltration of the muscularis propria with accompanying edema separating muscle fibers (the Eosinophil - Edema lesion). The duration and prevalence of symptoms, the male female ratio and the gross maximum circumference of the appendix in these 8 cases resembled classical acute appendicitis rather than those cases in which the morphology of the appendix was normal. The Eosinophil-Edema lesion was also seen in many cases of classical appendicitis in non-suppurative areas where neutrophils were sparse or absent. We hypothesize that this lesion is an allergic response and is probably an early event in the evolution of acute phlegmonous appendicitis. Acute eosinophilic appendicitis may merely be those cases that do not proceed on to suppuration.

Evidence for eosinophil degranulation in acute appendicitis.

Finding of increased numbers of eosinophils in the muscle in cases of acute appendicitis has led to the hypothesis that it may have an allergic origin. This study aimed to measure the eosinophil degranulation resulting in a rise in the serum of eosinophil granule proteins that would be expected in such cases. The levels of serum eosinophil cationic protein (ECP) measured by chemiluminescence assay in acute appendicitis were compared, with those of appropriate controls. Mean (95% CI) serum ECP (microg/L) levels were: acute appendicitis 45.3 (27.7-63.0); normal appendix 22.7 (16.0-29.3); asthma 24.2 (4.6-43.8); and healthy volunteers 13.2 (8.3-18.1). In cases of acute appendicitis, there is an inverse relationship between duration of symptoms and serum ECP. However, this was not statistically significant. Significant local eosinophil activation and degranulation occurs in acute appendicitis, enough to cause a rise in serum levels of eosinophil chemotactic protein.

Evidence based criteria for the histopathological diagnosis of toxoplasmic lymphadenopathy.

AIMS: To formulate evidence based histopathological criteria for the diagnosis of acquired toxoplasmic lymphadenitis, in an area of high tuberculosis prevalence. METHODS: Multiple histopathological parameters were assessed in a consecutive sample of biopsies from 68 patients presenting with lymphadenopathy with a duration of less than six months. Serum IgM enzyme linked immunosorbent assay was used as the standard reference test for the diagnosis of toxoplasmic lymphadenitis. The sensitivity, specificity, and likelihood ratios of various histological parameters were estimated. RESULTS: The presence of microgranulomas (p < 0.0001), paracortical widening (p = 0.006), paracortical hyperplasia (p = 0.02), monocytoid B cells in sinuses (p = 0.007), lower than grade 2 macrogranuloma (p = 0.002), and the absence of giant cells (p = 0.05) were found to discriminate between IgM positive cases and IgM negative controls. Using a composite criterion-(1) presence of microgranulomas, (2) lower than grade 2 macrogranuloma, (3) absence of giant cells, and (4) follicular hyperplasia-toxoplasmic lymphadenitis can be diagnosed with a high degree of sensitivity (100%), specificity (96.6%), and positive likelihood ratio (29). CONCLUSION: Toxoplasma lymphadenitis can be diagnosed with a high degree of confidence using the specific histopathological criteria identified here.

Hepatobiliary phaeohyphomycosis with secondary biliary cirrhosis.

We report a case of systemic phaeohyphomycosis in a 13-year old girl. The clinical presentation was with fever, weight loss, cholestatic jaundice with hepatosplenomegaly and generalized lymphadenopathy. The patient was diagnosed initially as tuberculous adenitis and was on antituberculous therapy, but with worsening of symptoms. Lymph node and liver biopsy showed granuloma with fungal hyphae suggestive of phaeohyphomycosis. The patient responded to antifungal therapy. Later she developed secondary biliary cirrhosis with cholangitis due to long stricture of the common bile duct and common hepatic duct requiring biliary stenting. To the best of our knowledge, this is the first report on phaeohyphomycosis causing biliary cirrhosis in the English lilterature.

Testicular choriocarcinoma with gastric metastasis presenting as hematemesis.

We report a 28-year-old man who presented with hematemesis due to choricarcinoma of testis metastatic to the stomach. Gastroscopy showed a polypoidal lesion. Testicular wedge biopsy confirmed mixed germ cell tumor, the choriocarcinomatous portion alone getting metastasized to the stomach. He was initiated on chemotherapy with actinomycin-D, etoposide and methotrexate, but died due to multiple metastases to the lung and brain.