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Biomedical subjects

G Mukherjee

Publications and source records attributed to G Mukherjee.

At least 37 records · Page 2Linked to original sources
PubMed2001

Physical fitness training for wheelchair ambulation by the arm crank propulsion technique.

OBJECTIVE: To observe the effect of endurance training on novice users of an arm-propelled three-wheeled chair (APTWC), powered by asynchronous arm crank propulsion, in actual locomotive conditions. STUDY DESIGN: A continuous endurance training programme was administered by instructing subjects to propel themselves at free chosen speed (FCS) for 15 minutes, twice daily. Data were collected at two-week intervals consecutively and this was continued until the maximum beneficial effect was achieved. SETTING: The study was conducted in outdoor settings similar to those the users encountered in their everyday life. SUBJECTS: Twelve male paraplegics (below T10), age 30.5 +/- 8.59 years, weight 41.75 kg (+/- 5.76) recommended to use the APTWC as an ambulatory device. INTERVENTION: The propulsion speed (metres per minute), peak heart rate (beats per minute) and oxygen uptake (litres per minute) were measured in consecutive sessions at two-week intervals. Physiological cost index (beats m(-1)), oxygen consumption (ml kg(-1) min(-1)) and oxygen cost (ml kg(-1) m(-1)) were derived to assess fitness level. RESULTS: Significant changes were observed in the variables following endurance training for 12 weeks. The propulsion speed increased considerably and the cardiorespiratory parameters were found to be reduced. One-way analysis of variance was done for each parameter separately for seven sets of readings taken to assess the overall change over the study period of 12 weeks. The F-ratios were found to be significant (p < 0.01) in each case, except for body weight and oxygen uptake. The pairwise comparison of the biweekly results of the parameters which showed an overall significant change over the study period revealed that after the first two weeks there was considerable change (p < 0.01) for all the parameters. The trend was upward for speed and downward for the other cardiovascular stress parameters. These trends continued until the 10th week showing significant change, after which the values become stable as was revealed by thestatistical tests (p > 0.05). The percentage difference in the mean values from the initial stage (before training) to the 12th week ranged from 10.44% in the case of heart rate to 69.70% in the case of propulsion speed. CONCLUSION: Self-ambulation at free chosen speed regularly for 10-12 weeks provides efficiency and improves fitness status required for wheelchairs driven by an asynchronous arm crank propulsion technique and no special exercise programme is required.

Adult↗
PubMed2000

Evaluation of ambulatory performance of the arm propelled three-wheeled chair using heart rate as a control index.

PURPOSE: The Arm propelled three wheeled chair (APTWC) is in common use in the economically poor countries for outdoor ambulation, the propulsion force of which is exerted by arm cranking in asynchronous fashion. The purpose of the study was to assess the ambulatory performance of the users of the device using heart rate as a control index, at graded speeds. METHOD: Fifteen regular users of APTWC male with paraplegia and poliomyelitis were ambulated at seven different graded speeds in outdoor settings and the resting and ambulatory heart rate was measured during steady state and then physiological cost index and comfortable speed of propulsion was computed. RESULTS: The physiological strain, linear regression of the relationship between heart rate and speed with correlation coefficient of r = 0.86 (p < 0.001), polynomial regression of the relationship between physiological cost index (PCI) and speed with correlation coefficient of r = 0.83 (p < 0.001) and comfortable speed of propulsion (120 m/min) was reported. CONCLUSIONS: Heart rate can be used to evaluate the ambulatory performance of the device, quantifying energy economy for outcome evaluation and decision making for clinical recommendation.

Adult↗
PubMed2000

Constitutive activation of FLT3 stimulates multiple intracellular signal transducers and results in transformation.

Aberrant expression of FLT3 has been found in most cases of B-lineage ALL and AML, and subsets of T cell ALL, CML in blast crisis and CLL. In 20% of patients with AML the receptor has small internal tandem duplications of the juxtamembrane region which appear to contitutively activate the receptor. To investigate whether FLT3 activation could play a role in leukemia, we generated a constitutively activated FLT3 by fusing its cytoplasmic domain to the helix-loop-helix domain of TEL in analogy to the fusion that occurs with TEL-PDGFR in CMML. In vitro translation assays demonstrated oligomerization and intrinsic tyrosine kinase activity of the TEL-FLT3 chimeric receptor. Constitutively activated TEL-FLT3 conferred IL-3 independence and long-term proliferation to transfected Ba/F3 cells. Immunoblot analyses showed that JAK 2, STAT 3, STAT 5a, STAT 5b and CBL were tyrosine-phosphorylated in TEL-FLT3 expressing Ba/F3 cells in the absence of IL-3. These data suggest a possible role for the JAK/STAT pathway in FLT3 signaling. Transplantation of TEL-FLT3 expressing Ba/F3 cells into syngeneic mice caused mortality in all mice by 3 weeks after injection. Histopathologic analysis demonstrated a massive infiltration of mononuclear cells in the liver, spleen and bone marrow. The mimicking of naturally occurring TEL fusions provides an approach to assess aspects of the biology of activated FLT3, or other receptor-type tyrosine kinases (RTKs) in leukemic transformation.

Animals↗
PubMed2000

Cestodiasis with intestinal diverticulosis in a lesser flamingo (Phoeniconaias minor).

An adult female lesser flamingo (Phoeniconaias minor), caught in the African Rift Valley in 1991 and subsequently housed at the Baltimore Zoo, died of severe visceral gout in 1996. Necropsy revealed a white, moderately firm, nodular lesion, 1 cm in diameter, in the serosal wall of the small intestine. Although it was initially thought to be a tumor or focal granuloma, histologic examination revealed multiple cestodes deeply embedded at the base of the crypts between the intestinal villi, with their massive scolices (up to 3.4 mm in diameter) distending these spaces into multiple diverticulae. The mucosal epithelium surrounding the scolices was severely attenuated. Around the diverticulae, in the submucosa and muscularis, was a mild to moderate lymphocytic reaction and mild fibrosis. The proximity of multiple scolices and extensive invasion of host tissue suggested that the infection occupied a preexisting lesion. The cestodes were cyclophyllids but were distinct from any species previously reported from flamingos. Helminths should be included in differential diagnoses for gastrointestinal nodules in flamingos.

Animals↗
PubMed1999

Comparisons of alloreactive potential of clinical hematopoietic grafts.

BACKGROUND: We sought to compare the immunoreactive potential of human cord blood (CB) versus normal adult bone marrow (BM) versus mobilized blood (peripheral blood stem cells; PBSC) from cancer patients. METHODS: Forty mice were randomized to receive a range of doses of T cell-replete cell preparations from one of the above three cell sources. Twenty-eight control mice underwent transplantation with T cell-depleted cells. Mice were observed for 60 days for the development of fatal xenogeneic graft-versus-host disease-like syndrome (GVHDLS). RESULTS: For the mice that had received T cell-replete grafts of CB or BM or PBSC, the duration of GVHDLS-free survival of the chimeras was inversely proportional to the number of T cells transplanted. After adjustment for the number of T cells transplanted, the relative hazard of developing fatal GVHDLS was 62-fold higher for PBSC and 210-fold higher for BM as compared with CB. Flow cytometric and histologic analyses of selected chimeras that died of GVHDLS showed extensive proliferation of human T cells in multiple organs. In contrast, mice that survived to day 60 were engrafted with human myeloid and B lymphoid cells. CONCLUSIONS: The immunoreactive potential, as measured by this in vivo assay, differed among clinical grafts: BM > PBSC > CB.

Adult↗
PubMed1999

A human-murine chimera model for in utero human hematopoietic stem cell transplantation.

To date, 16 in utero hematopoietic stem cell (HSC) transplants for diseases other than immunodeficiency disorders have been reported. No therapeutic level of engraftment was detected in 15 of these transplants. To overcome engraftment failure, we transplanted a very large number (5 billion paternal CD34+ cells/kg) of HSCs to a fetus with leukodystrophy during the first trimester of gestation. As reported previously, the fetus died in utero 7 weeks after the procedure and the cause of death appeared to be overwhelming donor engraftment. In the present investigation, we developed a human-murine chimera model to test for the optimal donor cell dose for human in utero transplantation. We found a strong correlation between the level of donor engraftment in three human fetuses transplanted for leukodystrophy during the first trimester of gestation and the results of parallel xenotransplants of the same human donor cells using the NOD/SCID mouse model. This small animal model appears to predict both extremes of hyperengraftment (seen in the first human fetus transplanted) and engraftment failure (seen in the second and third human fetuses transplanted in utero). These and future correlated clinical and laboratory assay results may be useful for the development of in utero transplants for a variety of congenital disorders.

Animals↗
PubMed1999

Feline asthma syndrome in African lions (Panthera leo).

Feline asthma syndrome, previously recognized only in domestic cats, was diagnosed in three captive African lions (Panthera leo), one of which died as a result of the condition. Two of the lions displayed progressive signs for 7 yr, including severe bouts of coughing, wheezing, dyspnea, rhonchi, and tachypnea that were most severe during the spring and summer, and the third lion displayed acute signs only once. Scattered to diffuse increased interstitial markings, peribronchial cuffing, and focal atelectasis were visible in radiographs. At necropsy, multiple subpleural bullae, 2-3 cm in diameter, were scattered throughout the lung tissue. There were thick-walled bronchi and bronchioles filled with thick grayish mucus, and alveolar spaces were enlarged with severe, diffuse, banded multifocal areas of alveolar wall fibrosis. The lions had significantly elevated IgE type I immediate hypersensitivity responses to recognized aeroallergens. The captive management of lions should address the design and maintenance of allergen-free air supplies. Ventilation systems should be examined routinely and thoroughly cleaned of any residue. The frequency of examination should increase during the summer. Lions and other large cats should be routinely screened for IgE aeroallergen-specific titers, asthma cases should be treated promptly with prednisolone, and investigations of etiology should be initiated.

Air Microbiology↗
PubMed1998

Organization and mobility of CD11b/CD18 and targeting of superoxide on the surface of degranulated human neutrophils.

A monoclonal IgM, specifically recognizing both CD11b and CD18 of human neutrophils, was used to examine the organization and mobility of CD11b/CD18 in the plasma membrane of human neutrophils degranulated by dihydrocytochalasin B (dhCB) treatment and fMet-Leu-Phe (fMLF) stimulation. Subcellular fractionation analysis of untreated or dhCB-treated control neutrophils indicated that 20% of CD11b/CD18 cosedimented with plasma membrane and the remainder with specific granules. In contrast, fMLF stimulation of dhCB-treated cells caused a major reorganization of CD11b/CD18, in which 60-70% of CD11b/CD18 sedimented in dense plasma membrane fractions that were also enriched in superoxide-generating NADPH oxidase activity. Similarly pretreated neutrophils were fixed, immunogold labeled, and examined by scanning electron microscopy. Immunogold particles were distributed uniformly over the symmetrically ruffled surface of unstimulated neutrophils. On dhCB-treated cells, immunogold was mostly uniformly distributed on a smooth membrane with a small percentage of particles lining up into linear arrays. After fMLF + dhCB stimulation, CD11b/CD18 gold label was more abundant on the cell surface and formed large aggregates on polarized membrane protrusions. However, when cells were adhered to an albumin-coated quartz surface and stimulated with fMLF in the presence of dhCB, immunogold was excluded on the articulated and rounded cell body but concentrated on the periphery of adherent lamellae. Fluorescence photobleaching recovery indicated that in unstimulated cells 38 +/- 3% of CD11b/CD18 was mobile (R) with a diffusion constant D of 3.1 +/- 0.3 x 10(-10) cm2/s. Treatment with dhCB raised R and D 24 and 74%, respectively. Stimulation using 1 microM fMLF with dhCB lowered D and R to near control levels. Since NADPH oxidase and CD11b/CD18 cosediment in high-density plasma membrane domains after fMLF + dhCB stimulation, we speculate that a stimulus-induced reorganization of CD11b/CD18 and NADPH oxidase to common membrane domains may occur in fMLF + dhCB-degranulated neutrophils.

CD18 Antigens↗
PubMed1998

Measurement and characterization of superoxide generation in microglial cells: evidence for an NADPH oxidase-dependent pathway.

While oxygen free radicals are important mediators of brain injury, questions remain regarding which cell types and enzyme pathways trigger this radical generation. Microglial cells have been hypothesized to be an important source of radical generation; however, the magnitude, kinetics, and mechanism of this process are unknown. Oxygen radical generation by stimulated primary microglia was directly measured and characterized by electron paramagnetic resonance spin trapping. Microglia, when stimulated by phorbol ester or opsonified zymosan, gave rise to EPR spectra characteristic of superoxide. Experiments performed in the presence of superoxide dismutase, catalase, deferoxamine, and dimethyl sulfoxide excluded generation of hydroxyl radicals in significant amounts. Microglial superoxide generation was blocked by the NADPH oxidase inhibitor diphenylene iodonium in a manner similar to that seen in neutrophils, suggesting that a neutrophil like NADPH oxidase was the source of superoxide production. However, microglia produced 20 to 40 times less superoxide compared to a similar number of neutrophils during the first 30 min following stimulation, indicating a marked difference in the regulation of NADPH oxidase activation. Western blots of microglia lysates demonstrated that both large (gp91-phox) and small (p22-phox) NADPH oxidase subunits are expressed in both unstimulated and stimulated microglia. Indirect immunofluorescence demonstrated localization at the membrane surfaces of activated cells. Thus, microglial cells generate superoxide via a neutrophil-like NADPH oxidase but exhibit distinctly different time course and magnitude of activation than that seen in neutrophils.

Animals↗
PubMed1997

Synovial sarcoma of the neck.

Primary synovial sarcoma of the head and neck region is a rare tumor. This report describes seven cases of primary synovial sarcomas, of which two were in the parapharyngeal region, two in the supraclavicular region, and one each in the hypopharynx, sternocleidomastoid and submandibular regions. Clinical presentations, radiological findings, histopathology and management are reviewed. All patients received multimodal therapy using aggressive surgery, radiotherapy and chemotherapy. Five of the patients are alive and disease free after 24-108 months of follow-up. Achievement of locoregional control appears to be the hallmark of successful therapy.

Adolescent↗
PubMed1997

The link between integration and expression of human papillomavirus type 16 genomes and cellular changes in the evolution of cervical intraepithelial neoplastic lesions.

We have matched a PCR assay which detects disruptions in the E2 reading frame of human papillomavirus type 16, with RNA in situ hybridization patterns and shown that in 15 out of 16 cervical intraepithelial neoplastic (CIN) III lesions and in 19 out of 19 tumours, the E2 gene is disrupted with no detectable E2 transcripts. Varying levels of E6-E7 transcripts are detected in CIN III lesions, with stronger signals in tumours. The cytokeratin profile of most tumours: cytokeratin 10-, 14- and 19-positive and 4-, 13- and 18-negative, is also detected in CIN III lesions. The changes in levels of alpha 2, beta 1 and beta 4 integrins, CD44 and E-cadherin occur during the evolution of high-grade CIN lesions. Increases in the levels of expression of CD44 and E6-E7 transcripts, coupled with changes in the cellular localization of the Notch protein, define the transition from CIN III lesions to tumours.

Cadherins↗
PubMed1996

Descriptive epidemiology of childhood cancers in Bangalore, India.

While fairly complete and reliable incident data on childhood cancers are available from the registries in India, mortality and survival information is not. Information concerning the latter was obtained by the Bangalore cancer registry through active follow-up involving visits to homes of patients. Between 1982 and 1989, 617 cases of cancers in childhood were registered, giving an age-standardized incidence rate of 84.8 and 48.4 per million in male and female children, respectively. Active follow-up provided mortality/survival information in 532 or 86.2 percent of these cases. Overall, observed five-year survival was 36.8 percent (both genders combined) with a relative survival of 37.5 percent when childhood mortality in the general population was taken into account. The five-year relative survival was best for thyroid carcinoma (100 percent) followed by Hodgkin's disease (73 percent) and retinoblastoma (72.9 percent). Survival was comparatively low, being 9.9 percent in acute nonlymphatic leukemia and less than 20 percent in rhabdomyosarcoma and the category grouped as 'other malignant neoplasms.' Survival in Hodgkin's disease was influenced by clinical stage at presentation, but was not statistically significant possibly due to small numbers.

Adolescent↗
PubMed1996

Pre leukemic granulocytic sarcoma of vagina. A case report with review of literature.

Granulocytic sarcoma is an extramedullary tumor of malignant granulocytic progenitor cells, that may precede the onset of acute myeloid leukemia or appear during the leukemic manifestation or blastic crisis of chronic myeloproliferative disorders. We describe a case of granulocytic sarcoma of vagina in a 27 year old woman treated with local radiotherapy. After seven months of follow up she developed acute myeloid leukemia. The case has been presented in view of its rarity and discussed in light of the available literature.

Adult↗
PubMed1995

Metal ion interaction with penicillins--Part VII: Mixed-ligand complex formation of cobalt(II), nickel(II), copper(II), and Zinc(II) with ampicillin and nucleic bases.

Equilibrium study on the mixed-ligand complex formation of M2+ ions (M = Co, Ni, Cu, and Zn) with alpha-d-(-)aminobenzyl penicillin popularly known as ampicillin, (hereafter, ampH +/-), and nucleic bases, viz. adenine, guanine, thymine, uracil, and cytosine (B), in aqueous solution at 37 degrees C at a fixed ionic strength, I = 0.1 M (NaNO3) indicates the formation of complexes of the types: M(amp), M(B), M(amp)(B), M(H-1 amp)(B), and M(H-1 amp)(B)(OH). Stability constants of the ternary complexes are in the order: Co2+ < Ni2+ < Cu2+ > Zn2+ with regard to the mental ions and guanine > adenine > uracil > thymine > cytosine with regard to the nucleic bases. Complex formation equilibria have been worked out on the basis of species distribution curves.

Ampicillin↗