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Biomedical subjects

R Kumar

Publications and source records attributed to R Kumar.

At least 1,711 records · Page 95Linked to original sources
PubMedDate not supplied

MR imaging of extracranial nerve sheath tumors.

We retrospectively reviewed MR images of 32 histologically proven extracranial nerve sheath tumors (NSTs). There were 23 benign (10 neurofibromas, 13 schwannomas) and 9 malignant NSTs. On T1-weighted images (T1WIs) tumors were isointense or slightly hyperintense to muscle. On T2-weighted images (T2WIs) (11 lesions) and enhanced T1WIs (1 intraspinal lesion), a target pattern with peripheral hyperintense rim and central low intensity was seen in 12 of 23 (52%) benign NSTs (5 of 10 neurofibromas and 7 of 13 schwannomas). This pattern corresponded histologically to peripheral myxomatous tissue and central fibrocollagenous tissue. The pattern was absent in lesions with cystic, hemorrhagic, or necrotic degeneration. These tumors were hyperintense and variably inhomogenous on T2WIs. Malignant NSTs were hyperintense and variably inhomogenous on T2WIs and mimicked benign variably inhomogeneous lesions unless involvement of contiguous structures was visualized. A target pattern was not visible in malignant lesions. Magnetic resonance imaging cannot distinguish schwannomas from neurofibromas, and benign tumors may mimic malignant NSTs when cystic, hemorrhagic, and necrotic degeneration is present. A target pattern may be visualized in some benign NSTs, and evaluation of this sign with assessment of location and growth along nerves may help to avoid confusion with other lesions.

Adult↗
PubMedDate not supplied

Differentiation of calcification from chronic hemorrhage with corrected gradient echo phase imaging.

PURPOSE: The purpose of the current study was to prospectively evaluate the role of corrected gradient echo phase imaging in differentiation of calcified granuloma from chronic hemorrhage. METHOD: Eighty-five patients with single/multiple calcifications and hemorrhages irrespective of their location were studied with corrected gradient echo phase imaging. In all the cases, CT was used as the gold standard for the presence/absence of calcification. RESULTS: All calcified lesions showed positive phase, whereas chronic hemorrhages showed negative phase in all cases. Five calcified lesions showed no phase shift at TE =15 ms and positive shift at TE = 35 ms. Heterogeneous phase shift was observed in three calcified lesions at TE = 35 ms; all three lesions showed positive phase shift at TE = 15 ms. There was no site-specific problem in differentiation of calcification from chronic hemorrhage including in the basal ganglia. CONCLUSION: We conclude that calcified granuloma can be easily differentiated from chronic hemorrhage with corrected gradient echo phase imaging, which may obviate the need for CT for its confirmation.

Adolescent↗
PubMedDate not supplied

Immunological profile of patients with non-cirrhotic portal fibrosis.

The aetiopathogenesis of non-cirrhotic portal fibrosis (NCPF), a common cause of portal hypertension in India, is not known. To study the immune status of NCPF patients and to see whether immunological mechanisms have a role to play, humoral and cell-mediated immunological studies were carried out in 43 patients with NCPF and compared with equal number of matched healthy controls and 31 patients with compensated liver cirrhosis. Serum immunoglobulin A (IgA) and complement (C3, C4) levels were significantly (P less than 0.001) lower in NCPF patients compared with controls and cirrhotics. There was no significant difference between the total or the relative concentration of the immunoglobulins and complements between NCPF patients and healthy controls, but, in patients with cirrhosis, concentration of all the immunoglobulins was higher. The cutaneous response to dinitrochlorobenzene was poorer in patients with NCPF, but the difference between cirrhotics and controls was not significant. A decrease in the suppressor/cytotoxic (T8) phenotype of lymphocytes in the peripheral blood and an increase in the ratio of helper/inducer (T4) and T8 lymphocytes was seen in patients with NCPF and cirrhosis. Although these results indicate definite immunological abnormalities in NCPF patients, their role in the pathogenesis of NCPF remains to be investigated.

Adult↗
PubMedDate not supplied

Stone composition, metabolic profile and the presence of the gut-inhabiting bacterium Oxalobacter formigenes as risk factors for renal stone formation.

OBJECTIVE: To examine stone composition, metabolic evaluation and colonization of Oxalobacter formigenes as risk factors for renal stone formation. SUBJECTS AND METHODS: Eighty patients with renal stones and 70 healthy controls were enrolled in the study. Of the 80 patients, 48 were first-time stone formers (FSF) and 32 were 'recurrent' stone formers (RSF), recurrent indicating 2 or more episodes of stone formation. Stone analysis by X-ray crystallography, 24-hour urine metabolic profile and detection of O. formigenes-specific DNA by PCR were performed for each patient. Detection of O. formigenes was also performed on 45 and urinary metabolic profile on an additional 25 controls. RESULTS: Calcium oxalate monohydrate was the major component of stones, hyperoxaluria and hypocitraturia were the most common urinary abnormalities in the 80 patients, 46% of RSF patients had hypercalciuria. Urinary abnormalities were far less frequent in the controls, with the exception of hypocitraturia (40%). Of the urinary metabolites, only calcium levels were significantly different (p < 0.05) between FSF (6.50 +/- 4.08 mmol/24 h) and RSF (8.21 +/- 5.26 mmol/24 h) patients. Colonization of O. formigenes was higher in controls (62.2%) than in FSF (33.3%) or RSF (28%) patients, it was least in patients with more than 4 episodes (7%) of stone formation. CONCLUSION: The findings indicate that lack of colonization of O. formigenes may be an important risk factor for recurrence of stone formation (calcium oxalate monohydrate).

Adult↗
PubMedDate not supplied

Fine needle aspiration of extramedullary myeloid cell tumor in myelodysplastic syndrome. A report of three cases.

BACKGROUND: Soft tissue tumors are rare in myelodysplastic syndrome (MDS), and the role of fine needle aspiration (FNA) cytology in their diagnosis has not been explored. CASES: Two patients with refractory anemia with excess blasts in transformation (RAEB-t) developed soft tissue swellings during the course of the illness. In a third patient, soft tissue swelling was a presenting feature. The swellings in all three cases were diagnosed as extramedullary myeloid cell tumor (EMT) on FNA and showed increased blasts (10-14%), dyspoietic changes, Auer rods and monocytosis. CONCLUSION: Soft tissue tumors appearing in MDS are likely to be EMTs. FNA is therefore particularly valuable in their diagnosis as morphology, cytochemistry, immunophenotyping and flow cytometric analysis of hematopoietic cells are best studied on aspirated material. We suggest that FNA be preferred over excisional biopsy for the diagnosis of soft tissue swellings in MDS.

Adolescent↗
PubMedDate not supplied

Semi-solid-state fermentation of Eicchornia crassipes biomass as lignocellulosic biopolymer for cellulase and 3-glucosidase production by cocultivation of Aspergillus niger RK3 and Trichoderma reesei MTCC164.

An aquatic weed biomass, Eicchornia crassipes, present in abundance and leading to a threatening level of water pollution was used as substrate for cellulase and beta-glucosidase production using wild-type strain Aspergillus niger RK3 that was isolated from decomposing substrate. Alkali treatment of the biomass (10%) resulted in a 60-66% increase in endoglucanase, exoglucanase, and beta-glucosidase production by the A. niger RK3 strain in semi-solid-state fermentation. Similarly, the alkali-treated biomass led to a 45-54% increase in endo- and exoglucanase and a higher (98%) increase in beta-glucosidase production by Trichoderma reesei MTCC164 under similar conditions. However, the cocultivation of A. niger RK3 and T. reesei MTCC164 at a ratio of 3:1 showed a 20-24% increase in endo- and exoglucanase activities and about a 13% increase in the beta-glucosidase activity over the maximum enzymatic activities observed under single culture conditions. Multistep physical (ultraviolet) and chemical (N-methyl-N'-nitrosoguanidine, sodium azide, colchicine) mutagenesis of the A. niger RK3 strain resulted in a highly cellulolytic mutant, UNSC-442, having an increase of 136, 138, and 96% in endoglucanase, exoglucanase, and beta-glucosidase, activity, respectively. The cocultivation of mutant UNSC-442 along with T. reesei MTCC164 (at a ratio of 3:1) showed a further 10-11% increase in endo- and exoglucanase activities and a 29% increase in beta-glucosidase activity in semi-solid-state fermentation.

Aspergillus niger↗
PubMedDate not supplied

Use of simple hematological, biochemical and clinical parameters to monitor response of multiple myeloma patients on high dose thalidomide therapy.

BACKGROUND: Evidence of increased bone marrow vascularity in multiple myeloma (MM) has led to the use of anti-angiogenic drugs especially thalidomide in relapsed or refractory patients. Currently, parameters such as serum/ urine electrophoresis for M (monoclonal) proteins, bone marrow biopsy with touch preparation and b2 microglobulin are routinely used to assess response to therapy. These investigations are expensive, invasive and require high technical setup. AIM: To correlate simple and routine hematological and biochemical parameters with the key marker of disease i.e. M proteins. SETTINGS AND DESIGN: This is an open label, uncontrolled, single-arm study. MATERIALS AND METHODS: Twenty nine refractory or relapsed multiple myeloma patients of both sexes (M=20, F=9) with age ranging between 35-72 years were initiated on 200 mg/day of thalidomide with fortnightly increments of 200 mg to a maximum tolerated dose not exceeding 800 mg/day. All hematological and biochemical parameters were monitored at monthly intervals for one year. STATISTICAL ANALYSIS: Correlation analysis was performed between hemoglobin (Hb), total leukocyte count (TLC), absolute neutrophil count (ANC), platelet count (PC), total proteins (TP), serum albumin and serum globulin on one hand and M protein levels on the other using Pearsons Correlation test by SPSS version 7.5. RESULT: Hb, TLC, ANC, PC and serum albumin levels showed a significant negative correlation with M proteins. A highly significant positive correlation existed between M proteins on one hand and TP and globulin levels on the other. Dryness of skin indicated positive response to therapy. These correlations were found to be significant at the end of one month of therapy in all the above-mentioned parameters except in TLC where it was significant after 2 months of thalidomide therapy. CONCLUSION: Results suggest that sustained efficacy of thalidomide therapy may be amenable to monitoring by these simple, inexpensive and easily available investigations after ascertaining an initial response by M protein and marrow plasmacytosis as these parameters closely follow M protein levels. However more studies are required to further substantiate these findings.

Adult↗
PubMedDate not supplied

Second echelon node predicts metastatic involvement of additional axillary nodes following sentinel node biopsy in early breast cancer.

BACKGROUND: In many patients with early breast cancer, the sentinel lymph node (SLN) is the sole site of regional nodal metastasis. This subgroup of patients may not benefit from completion axillary lymph node dissection (CALND). AIMS: This pilot study evaluates the status of 2nd echelon (station) lymph nodes in the axilla as a predictor of additional positive nodes in the axilla in the presence of sentinel node metastasis. SETTINGS AND DESIGN: Cross-sectional study of 40 breast cancer patients. MATERIALS AND METHODS: Forty patients with invasive breast cancer underwent SLN biopsy followed by 2nd echelon lymph node biopsy in the same sitting. SLN mapping was performed using a combined technique of isosulfan blue and 99 mTc-sulfur colloid. SLNs (Station I) were defined as blue and/or hot nodes. These nodes were then injected with 0.1 ml of blue dye using a fine needle and their efferent lymphatic was traced to identify the Station II nodes. Then a complete ALND was performed. All the specimens were sent separately for histopathological evaluation. RESULTS: SLNs (Station I nodes) were successfully identified in 98% (39/40) patients. Of the 17 patients with a positive SLN, 8 (47%) patients had no further positive nodes in the axilla, 9 (53%) patients had additional metastasis in nonsentinel lymph nodes upon CALND. Station II nodes were identified in 76% (13/17) patients with a positive SLN. Station II nodes accurately predicted the status of the remaining axilla in 92% patients (12/13). STATISTICAL ANALYSIS: We calculated the Sensitivity, Negative predictive value, Positive predictive value, False negative rate and Identification rate. CONCLUSION: Station II nodes may predict metastatic involvement of additional nodes in the axilla.

Adult↗
PubMedDate not supplied

A study of anti-neutrophil cytoplasm antibodies in systemic vasculitis and other related disorders.

BACKGROUND: Anti-neutrophil cytoplasm antibodies (ANCA) play an important role as specific and sensitive markers for small vessel vasculitis and in some other systemic disorders. Indirect immunofluorescence test, known as the "Gold Standard" for screening of ANCA, can be further substantiated by ELISA for confirmation and for identifying sub-specificities like anti-Myeloperoxidase (anti-MPO), anti-Proteinase 3 (anti-PR3) and anti-Lactoferrin (anti-LF). AIMS: The present study was undertaken to investigate the incidence, specificities and strength of ANCA in suspected vasculitis cases and to correlate their presence with that of these auto-antibodies and with the disease. SUBJECTS AND METHODS: Sera from 130 clinically suspected vasculitis patients were studied. Indirect immunofluorescence microscopy (IIF) was used to identify cytoplasmic (c-ANCA), perinuclear (p-ANCA) and atypical (X-ANCA) patterns using ethanol and formalin fixed polymorphonuclear cells (PMN) and HL-60 cells from a human promyelocytic leukaemic cell line as substrates. ELISA was performed for identifying ANCA sub-specificities to anti-MPO and anti-PR3 and HEp-2 cells were used for detection of anti-nuclear antibodies (ANA). RESULTS: ANCA positivity was noted in 42.3% of these patients, wherein p-ANCA positivity rate was 34.6% and c-ANCA positivity was noted in 5.4% subjects. Three patients showed the unusual X-ANCA positivity. ELISA determined the sub-specificities: Out of 45 p-ANCA positive patients, 38 patients (84.4%) had anti-MPO and out of 7 c-ANCA positive patients, 5 patients (71.4%) had anti-PR3 antibodies. One patient with Class IV Lupus Nephritis, showed both anti-MPO and anti-PR3 antibodies and 17.8% p-ANCA positive patients had anti-Lactoferrin antibodies. CONCLUSIONS: Use of the Immunofluorescence method coupled with identification of ANCA sub-specificities by ELISA, is recommended for detection of ANCA in clinically suspected cases of small vessel and other systemic vasculitis.

Antibodies, Antineutrophil Cytoplasmic↗
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Pharmacokinetics, bioavailability and dosage regimen of sulphadimidine in camels (Camelus dromedarius) under hot, arid environmental conditions.

A two-way crossover study was conducted in young Bikaneri camels (aged between 12 and 18 months) during the hot summer season to determine the bioavailability, pharmacokinetics and dosage regimens of sulphadimidine (SDM). A dose of 100 mg.kg-1 of SDM was used to study both the intravenous and oral pharmacokinetics of the drug. Analysis of the intravenous data according to a two-compartment pharmacokinetic model revealed that SDM was well distributed in the body (Vd(area):0.862 L.kg-1), had an overall body clearance of 0.035 +/- 0.019 L.h-1.kg-1 and the elimination of half-lives was in the range of 14.2 to 20.6 h. The mean maximum plasma SDM concentration following oral administration was 63.23 +/- 2.33 micrograms.mL-1, which was achieved 24 h after the oral administration. The mean bioavailability of SDM following oral administration was approximately 100%. To achieve and maintain the therapeutically satisfactory plasma sulphadimidine levels of > or = 50 micrograms.mL-1, the optimum dosage regimen for camels following either intravenous or oral administration would be 110 mg.kg-1 as the priming dose and 69 mg.kg-1 as the maintenance dose, to be repeated at 24 h intervals.

Animals↗
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Effects of experimentally induced Theileria annulata infection on the pharmacokinetics of oxytetracycline in cross-bred calves.

The effects of an experimental Theileria annulata infection on the intravenous (10 mg kg-1) pharmacokinetics of oxytetracycline (OTC) were investigated in crossbred calves. The serum concentration-time curve of oxytetracycline before and after the experimental infection was best described by an open two-compartment model. The experimental infection was induced by a subcutaneous administration of ground-up tick supernate (GUTS) equivalent to 30 Hyalomma anatolicum anatolicum ticks infected with Theileria annulata. It produced a definite temperature rise and symptoms of clinical disease in the calves. The haemoglobin, packed cell volume (PCV), white blood cell (WBC) counts and serum Cu, Fe and Zn concentrations decreased after onset of the infection. The distribution and elimination half-lives (t1/2 alpha and t1/2 beta), volume of the central compartment (Vc), AUC0-infinity, AUMC and mean residence time (MRT), were significantly reduced (P < or = 0.05) and the hybrid rate constants K12, Kel, K12/K21 ratio and total body clearance (ClB) of oxytetracycline were significantly (P < or = 0.05) increased after infection. The infection, however, had no effect on the C0, K21, apparent and steady-state volumes of distribution (Vd(area) and Vdss) of the drug. The above changes may necessitate changes in the dosage regimen of oxytetracycline used to treat Theileria infections in cattle under field conditions.

Animals↗
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Radiation induced sarcoma following treatment of breast cancer.

The occurrence of radiation induced sarcoma following treatment of breast cancer is rare. It has an average latency of ten years and it correlates with the dose and technique of radiation. The prognosis is poor due to delay in diagnosis. We present a case where a female patient developed a chondrosarcoma of sternoclavicular joint 19 years after radiotherapy for breast cancer.

Aged↗
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Local anaesthetic for minor oral surgical procedures. Review.

Pain following any surgical procedure is difficult to combat by man. Analgesics can be given for some amount of symptomatic relief. The need for a long lasting local anaesthetic is with the intention to reduce the most severe nature of pain, and decrease the analgesic consumption. This study was conducted to compare the efficacy of, Bupivacaine over Lidocaine for minor oral surgical procedures. The popularly used lidocaine works for 3 to 3.9 hours. This is not sufficient since the most severe nature of pain is felt six to eight hours post surgery, where as Bupivacaine has duration of action of seven to eight hours. Hence the post operative pain experienced following administration of bupivacaine was found to be considerably lesser in degree than compared to the lidocaine group. To avoid severe pain and discomfort to the patient following any minor oral surgical, the use of bupivacaine is recommended.

Adult↗