Search PubMed⌕ Search

Biomedical subjects

M K Singh

Publications and source records attributed to M K Singh.

At least 19 recordsLinked to original sources

Integrative Genomic and Transcriptomic Insights into High-Altitude Adaptation in Changthangi Goats.

The Changthangi goat, native to the high-altitude Ladakh Plateau in northern India, thrives in oxygen-deficient environments above 4,000 m. This study investigated the genetic basis of high-altitude adaptation in Changthangi goats by integrating comparative genomics and transcriptomics, using the tropical lowland Jamunapari goat as a comparative model. Whole-genome sequence data from 15 individuals per breed were analyzed using complementary selection sweep metrics, including nucleotide diversity, Tajima's D, iHS, CLR, XP-EHH, and FST. These analyses identified candidate genomic regions under strong selective pressure, encompassing genes involved in hypoxia sensing (HIF-1α, HIF-2α/EPAS1, EGLN1), angiogenesis (VEGFA, AGGF1, ZEB1), cardiovascular regulation (PRKCB, ESR1, RYR2), mitochondrial and energy metabolism (ACADSB, ACSS3, ACSL1), cellular stress tolerance (BCL2, ATM), and thermogenesis (UCP1, FGF21). Unlike previous caprine studies that primarily infer hypoxia adaptation from genomic signals alone, our study integrates cardiac transcriptomics to demonstrate that genomic selection in Changthangi goats is accompanied by coordinated transcriptional remodeling across interconnected physiological systems in a physiologically relevant tissue. Comparative cardiac transcriptomic profiling revealed concordant expression divergence in genes associated with oxygen transport, vascular remodeling, mitochondrial function, substrate utilization, redox balance, and genome maintenance. This integrative multi-omics framework provides a mechanistic view of caprine high-altitude adaptation and highlights the value of combining genomic selection analyses with tissue-specific transcriptional profiling to resolve complex adaptive traits.

Animals↗

Resistance training increases glucose uptake and transport in rat skeletal muscle.

The aim of this investigation was to determine if resistance training exercise improved glucose uptake and transport in rodent skeletal muscle. Sprague-Dawley rats were assigned to one of the three groups: control (CON), resistance trained (RT) and aerobic exercise trained (AT). Resistance trained rats were placed in a rodent squat apparatus and performed three sets of 10 repetitions at 75% of their one repetition maximum 3 days week-1 for 12 weeks. Aerobic exercise training consisted of running the rats 3 days week-1 for 45 min over a 12-week period on a motor-driven treadmill (32 m min-1, 15% grade). Following the training period, all animals were subjected to hind limb perfusion in the presence of 500 microU mL-1 insulin. Hind limb glucose uptake was similar in the RT (9.91 +/- 0.7 micromol g-1 h-1) and AT (10.23 +/- 1.0 micromol g-1 h-1) animals and significantly greater than control (CON) (6.40 +/- 0.6 micromol g-1 h-1). Rates of 3-O-methyl-d-glucose transport in the RT animals were elevated in the muscles utilized for RT while in the AT animals rates of 3-O-methyl-d-glucose transport were increased in those muscles recruited for running. The increased rates of 3-O-methyl-d-glucose transport in the skeletal muscles of the resistance trained and aerobic exercise trained animals appeared to be, in part, because of an increased GLUT4 protein concentration. These findings suggest that both resistance or aerobic training exercise can improve insulin-stimulated skeletal muscle glucose uptake and transport, but the training adaptations are restricted to the muscles recruited for the exercise performance.

3-O-Methylglucose↗

Posterior leukoencephalopathy in a girl with acute haemorrhagic leukoencephalitis.

In children, posterior leukoencephalopathy is frequently associated with hypertensive encephalopathy, anticancer chemotherapy, treatment with immunosuppressive drugs in patients with organ transplantation, transfusion or human immunodeficiency virus infection. Posterior leukoencephalopathy in these children appears as a complicating illness and resolves once precipitating factor (e.g. cancer chemotherapy) is removed. Here we are reporting a fatal case of acute haemorrhatic leukoencephalitis in a 13 year old girl, imaging abnormalities are also suggestive of posterior leukoencephalopathy. Posterior leukoencephalopathy in our patient possibly, is a part of post-infectious haemorrhagic leukoencephalitis, rather than because of ischaemia or cerebral oedema secondary either to abrupt increase in blood pressure or following administration of immunosuppressive drugs.

Adolescent↗

Panniculitides--a clinicopathologic study.

OBJECTIVES: To describe the clinical and pathologic features of panniculitides, an uncommon group of diseases, where the available Indian literature is sparse. MATERIAL AND METHODS: Prospective four years study of patients presenting with panniculitis to a large teaching hospital in North India. RESULTS: Erythema nodosum (EN) was the commonest panniculitis (79.3% cases) in our cohort. Other causes included erythema induratum, Weber Christian disease, cutaneous polyarteritis nodosa and panniculitis associated with Takayasu's arteritis and dermatomyositis-lupus overlap. Elevated ESR and leukocytosis were the common laboratory abnormalities encountered. Septal panniculitis without vasculitis was the most frequent histopathologic pattern observed. Patients of EN did well on nonsteroidal anti-inflammatory drugs while corticosteroids with or without azathioprine were used to treat other panniculitides. CONCLUSIONS: Physician awareness, clinical pattern recognition and histopathological confirmation, all play a key role in the identification and management of panniculitis.

Adipose Tissue↗

A long-term follow-up of an HIV type 1-infected patient reveals a coincidence of Nef-directed cytotoxic T lymphocyte effectors and high incidence of epitope-deleted variants.

Cytotoxic T lymphocytes (CTL) play a critical role in controlling human immunodeficiency virus-1 (HIV-1) and simian immunodeficiency virus (SIV) infections. However, in spite of developing a strong CTL response most HIV-1-infected patients eventually progress to AIDS. Amino acid changes in CTL epitope have been previously described and may permit HIV to escape from CTL immune responses. The importance of CTL selection pressure in controlling the course of viral evolution in HIV-infected patient remains debatable. For over a 10-year period, we longitudinally followed a patient for bulk unstimulated effector (eCTL) and stimulated memory CTL responses (mCTL) against the viral proteins Gag, Pol, and Nef. The patient showed a strong CTL response against Nef in unstimulated peripheral blood mononuclear cells with a peak during Month 40 of the follow-up. The mCTL response was also higher against Nef than Gag and Pol. PCR amplification and nucleotide sequencing of the plasma viral variants showed a viral variant with the epitope deletion that was detected early during the follow-up and essentially replaced the wild-type virus during the peak eCTL response. These studies support the importance of Nef epitope deletion as a mechanism for HIV-1 escape from CTL immune pressure.

Amino Acid Sequence↗

Extranasopharyngeal angiofibroma arising from the nasal septum.

Extra nasopharyngeal origin of angiofibroma is very rare. The nasal septum is a very rare site of extra nasopharyngeal angiofibroma with only two cases reported in the medical literature. We report here a case of a vascular mass arising from the nasal septum of an 8 year old boy. Histopathology confirmed it to be a case of angiofibroma. A review is also made of the other reported cases of angiofibroma arising from the nasal cavity. The likely theory of origin of the tumor and the management is also discussed.

Angiofibroma↗

Utility of fine-needle aspiration cytology in the classification of leprosy.

The role of fine-needle aspiration cytology (FNAC) in the diagnosis of benign skin lesions has been restricted primarily to the evaluation of bacteriologic and morphologic indices in leprosy. This study was undertaken to evaluate the efficacy of FNAC in the diagnosis and classification of lepromatous lesions. Aspirates of 94 newly diagnosed cases of leprosy were studied, and the bacterial load was determined by modified Ziehl-Neelsen (ZN) stain. A skin biopsy was taken from the same site at the same sitting. Frozen and paraffin sections stained with hematoxylin-eosin (H&E) and ZN stains were examined from the biopsy specimen. In 61 of 94 cases (64.9%), the aspirates were satisfactory. Both diagnosis and classification of leprosy were possible in 40 of these 61 cases; the rest of the aspirates showed nonspecific chronic inflammation. The 39 cases of leprosy where a biopsy was available from the same site were classified on FNAC into tuberculoid (TT and BT), lepromatous (LL and BL), and midborderline (BB) subtypes. Taking the histologic diagnosis and Ridley-Jopling classification to be the gold standard, a strong concordance in tuberculoid leprosy cases (18 of 20 cases, 90%) and in lepromatous cases (15 of 16 cases, 93.7%) was observed. Midborderline cases of leprosy posed a problem, and a correct cytohistological correlation was observed in only one of the three cases.

Adolescent↗

Single small enhancing computed tomographic (CT) lesions in Indian patients with new-onset seizures. A prospective follow-up in 75 patients.

This study was planned to observe the clinical and radiological course of single small enhancing CT lesions in Indian patients presenting with new-onset-seizures. In this study, 75 patients with new-onset seizures and a single enhancing CT lesion were prospectively followed up for 1 year. All patients fulfilled the criteria of cysticercus granuloma. The repeat CT scans were performed 2 months after the first CT scan. Antiepileptic drug therapy was the only form of treatment given. The majority of patients were below 20 years of age. Simple partial seizure, with or without secondary generalization, was the commonest type of seizure encountered in these patients. In follow-up CT scans 84% of patients showed either disappearance or regression in the size of lesion. The proportion of patients showing complete disappearance of CT lesions was 0.73 (95% CI, 0.61-0.80). In 11 (15%) patients the lesions were calcified. In nine patients, in whom the lesion had persisted or regressed, another follow-up CT scan (6 months after the second scan) revealed either complete disappearance or calcification of the lesions. The majority (86.6%) of patients remained seizure free for 1 year after starting antiepileptic drugs. Ten patients experienced seizure recurrences within the first month of therapy. The proportion of patients who remained seizure free was 0.86 (95% CI, 0.76-0.92). Four patients experienced seizure recurrence even after complete disappearance of CT lesions. In the majority of patients the lesions disappeared spontaneously and in a few the lesions calcified; hence these patients did not require anticysticercal therapy. Antiepileptic therapy was helpful in controlling further recurrences of seizures in most of the patients. A few patients experienced seizures even after disappearance of CT lesions.

Adolescent↗

Laparoscopic management of Sertoli-Leydig cell tumors of the ovary. A report of two cases.

BACKGROUND: Sertoli-Leydig cell tumor is a rare ovarian tumor with an incidence of < .5% of all ovarian tumors. Laparotomy is the standard approach to these cases. CASES: Sertoli-Leydig cell tumors were diagnosed in two young, nulliparous, infertile women. Both presented with secondary amenorrhea. Virilization was found in one. Their testosterone levels were high, and sonography revealed a solid, echogenic mass in the fornix. Laparoscopic removal was performed. Both women achieved normal menstruation one month after the operation, and one became pregnant and gave birth to a healthy infant. CONCLUSION: There are very few case reports of laparoscopic removal of such tumors. Laparoscopic surgery, which is minimally invasive and cosmetically acceptable and has a speedy recovery, should be the approach of choice for these patients.

Adult↗

Diabetic retinopathy and microalbuminuria in lean type 2 diabetes mellitus.

BACKGROUND: Relationship between microalbuminuria and diabetic retinopathy in patients with type 1 and type 2 diabetes mellitus has been described. Patients with lean type 2 diabetes mellitus has some difference of insulin secretion and action in comparison with obese type 2 diabetes mellitus and there are evidences to support that lean type 2 diabetes mellitus is slow emerging type 1 diabetes mellitus in our population. The aim of this study is to find out correlation between retinopathy and microalbuminuria in lean type 2 diabetes mellitus. METHODS: Fifty two patients with lean type 2 diabetes mellitus (BMI < 18.5 Kg/M2) were selected. Diabetic retinopathy was observed in 25 patients only. Blood glucose sample was taken after 10 hours of overnight fasting. Glycosylated haemoglobin (HbA1c) was measured by calorimetric method and urinary albumin was estimated in morning urine saniple by Micral II test strip. RESULTS: Patients with diabetic retinopathy had longer duration of diabetes detected than those with normal fundus but the difference was statistically insignificant. Fasting blood glucose greater than 200 mg/dl was found in 63.6% of patients with diabetic retinopathy and in 36.4% of patients with normal fundus but the difference was insiginificant. Patients with diabetic retinopathy had microalbuminuria test positive and level was significantly higher in patients with proliferative retinopathy than in patients with background retinopathy. CONCLUSION: Microalbuminuria is associated with diabetic retinopathy in lean type 2 diabetes mellitus. Increase in urinary albumin excretion correlates with development of proliferative diabetic retinopathy in lean type 2 diabetes mellitus similar to type 1 and type 2 diabetes niellitus. This study emphasizes that microalbuminuria estimated by semi quantitative method is a cost effective and reliable marker of diabetic retinopathy in lean type 2 diabetes mellitus and high level of this may serve as an indicator of proliferative retinopathy in them.

Adult↗

Internet resources for the human geneticist.

The Internet is a massive expanding body of information, which is likely to play a significant role for clinicians and researchers across the world. Since its inception in December 1969 the Internet has grown rapidly and is anticipated to expand 1,000% in the coming next few years. Various useful databases on human genetics are already in 'the Net' and many more are being added constantly. The future of human geneticist is in handling of information. In this review of Internet and compilation of important web site addresses we expect to stimulate and instruct human geneticists in navigating the Net. The list of web sites provided in this article is expected to facilitate their search.

Databases, Genetic↗

Villoglandular papillary adenocarcinoma of the cervix: case report.

The incidence of cervical adenocarcinoma is on the rise over the last several decades. It generally carries a worse prognosis than squamous carcinoma. Villoglandular papillary adenocarcinoma (VGA) of the cervix has been identified as a distinct subset of cervical adenocarcinoma that occurs in young women and supposedly carries an excellent prognosis. We report a case of adenocarcinoma of the cervix in a young woman that had classical histological features of VGA but at operation showed presence of tumor cells in the peritoneal wash. A review of world literature on the 56 cases reported so far is presented where occasional cases showing disease spread have been reported, suggesting caution in the management and follow-up of this clinicopathologic entity.

Adenocarcinoma, Papillary↗

Cervical carcinoma recurring in an abdominal wall incision.

Incisional recurrence of carcinoma of the uterine cervix is very rare. We report two patients who developed recurrence in the abdominal wall incision after hysterectomy. The first patient was aged 60 years and had a FIGO Stage IB1 cervical carcinoma treated initially by Wertheim's hysterectomy and postoperative radiotherapy. Nine months after surgery she developed recurrence on the abdominal scar, which was outside the radiation portal. She was treated with electron beam radiation therapy. The second patient developed an incisional recurrence 23 months after surgery and was treated by wide excision of the mass followed by radiotherapy. A survey of the literature identified 12 reported cases to date (eight squamous cell carcinoma and four adenocarcinoma).

Abdominal Muscles↗