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Biomedical subjects

P Kumar

Publications and source records attributed to P Kumar.

At least 613 records · Page 34Linked to original sources
PubMed1988

The subaxillary pedicled flap.

The subaxillary fasciocutaneous flap is a new pedicled flap designed and developed by us for resurfacing defects on the dorsum of the hand, thumb, fingers and web-spaces. The lack of mobility and inability of the patient to dress properly during transfer of a groin or hypogastric flap prompted us to develop this flap which is based on the direct cutaneous branch of the subscapular-thoracodorsal arterial axis to the lateral thoracic region. It consists of skin, subcutaneous tissue and the underlying fascia. It is located in the region of the lower half of the lateral chest wall extending from 5th to 10th rib to the mid-axillary line and can be raised without any delay. The donor defect can be closed primarily or skin grafted if necessary and can be very easily taken care of during hospitalisation. It can be nicely concealed later on in life. The subaxillary fasciocutaneous flap has been tried by us in 10 cases and the results are presented in this paper.

Adult↗
PubMed1988

Fluorescence histochemical double staining for the localization of intracellular hydrolases and tubercle bacilli.

Fluorescence histochemical techniques are described to localize intracellular enzyme and tubercle bacilli in alveolar macrophages obtained from infected guinea pigs. The study demonstrated a double-staining technique using 4-methylumbelliferyl substrates for enzyme localization followed by auramine-O staining for intracellular tubercle bacilli. Upon enzyme substrate reaction, released 4-MU remains retained inside the cell and gives a green fluorescence, whereas tubercle bacilli give a yellow fluorescence of auramine staining. The technique is useful where a correlation of enzyme activity vs a presence of bacilli in vivo is required at the single cell level.

Animals↗
PubMed1988

Median cleft lip with bimanual hexadactyly and bilateral accessory toes. Report of two cases in the same family.

The present paper presents two brothers with a median upper lip cleft, associated with postaxial hexadactyly of both hands and feet. Very few similar cases have previously been reported in the literature by various workers. The similarity between the cases reported in the literature and the two cases presented here indicates the existence of a median cleft lip-hexadactyly-syndrome.

Child↗
PubMed1988

Synthesis and biological evaluation of poly-gamma-glutamyl metabolites of 10-deazaaminopterin and 10-ethyl-10-deazaaminopterin.

The chemical synthesis of a series of poly-gamma-glutamyl metabolites of the experimental anticancer drugs 10-deazaaminopterin (10-DAAM) and 10-ethyl-10-deazaaminopterin (10-EDAAM) has been carried out by the solid-phase procedure. The synthetic products were identical with the poly-gamma-glutamyl metabolites of radiolabeled 10-DAAM and 10-EDAAM produced by normal mouse tissues with regard to elution volume from [(diethylamino)ethyl]cellulose columns and susceptibility to hydrolysis by human plasma folylpolyglutamate hydrolase. Poly-gamma-glutamyl metabolites with a glutamate chain length of up to four glutamate residues were detected in the tissues. The antifolate activity was evaluated with methotrexate (MTX) sensitive and MTX-resistant strains of Lactobacillus casei and Streptococcus faecium. In general, inhibitory potency decreases with increasing Glu chain length. However there are two exceptions. Addition of one Glu residue to 10-DAAM enhances its potency for MTX-resistant L. casei and addition of one Glu residue to 10-EDAAM enhances its potency for the MTX-sensitive L. casei. As shown earlier for MTX polyglutamates, polyglutamylation greatly enhances the inhibitory potency of 10-DAAM and 10-EDAAM for L. casei thymidylate synthase. MTX polyglutamates are 15-30 times more inhibitory than the corresponding 10-DAAM derivatives and 30-60 times more inhibitory than the corresponding 10-EDAAM derivatives. Polyglutamylation of 10-DAAM had little influence on its ability to inhibit L. casei dihydrofolate reductase; however, with 10-EDAAM, addition of one or two Glu residues enhanced its inhibitory potency 2.3-fold.

Aminopterin↗
PubMed1988

Cyclophosphamide in renal transplantation.

Success in renal transplantation is now largely dependent on safe and effective immunosuppression. Nonspecific immunosuppression by chemical agents continues to be the mainstay of clinical immunosuppression. Azathioprine and prednisolone have remained the two main drugs used in combination in standard immunosuppressive therapy in renal transplantation for many years. Although cyclophosphamide (CP) was tried in the early years of transplantation, enthusiasm for its use was dampened by the advent of newer agents. We have analyzed our experience with 29 recipients of living-related donor (LRD) renal allotransplantation on cyclophosphamide therapy. Cyclophosphamide is a safe and effective alternative to azathioprine in clinical renal allotransplantation. Due to its easy availability and the fact that it is a cheaper alternative to azathioprine and cyclosporine, it is more significant for developing countries.

Adult↗
PubMed1988

Tissue measurements in senile sebaceous gland hyperplasia.

Senile sebaceous gland hyperplasia has been studied in 18 subjects in an attempt to shed some light on its pathogenesis. The sizes of different segments of the pilosebaceous unit were compared in senile sebaceous gland hyperplasia (SGH) and in control skin samples, using stereological techniques. The whole follicle was found to be significantly increased in volume compared with follicular structures in the control specimens. The size of differentiated sebaceous gland cells was found to be reduced compared with controls (490 +/- 72 microns 2 and 554 +/- 98 microns 2, respectively), but not significantly so. The mean tritiated thymidine autoradiographic labelling index determined in vitro was found to be decreased (5.42 +/- 1.79) compared with controls (7.48 +/- 2.44), but again, not significantly so. In addition the degree of solar elastotic degenerative change was found to be similar in SGH bearing skin compared with control samples. It is of interest that SGH and prostatic hypertrophy are exceptions to the usual atrophy of ageing and that both tissues are androgen dependent.

Aged↗
PubMed1988

Do oxygen tension variations contribute to the respiratory oscillations of chemoreceptor discharge in the cat?

1. A high-frequency high-flow ventilator has been developed which will produce abrupt changes in alveolar gas tensions. We have used it to study the individual contributions of PCO2 and PO2 in producing the oscillations which occur in the discharge of carotid chemoreceptors in the cat with respiration, by producing repeated end-tidal alternations (i) of PCO2 in constant hypoxia, (ii) of PO2 in constant normocapnia and (iii) of both PO2 and PCO2, i.e. of asphyxia. 2. The chemoreceptor response to alternations of PCO2 was always brisker than that to alternations of PO2 at 2, 4 or 8 s cycle durations. 3. An increase in the frequency of the alveolar alternation shortened the difference between the response times to PCO2 and PO2 but it increased the phase difference between the stimulus and the response waveforms. 4. With 4 s cycles, in normocapnic hypoxia, PCO2 was 2.9 times more effective (impulses s-1 Torr-1) than PO2 in producing oscillations in discharge. 5. The oscillations in discharge to simultaneous alternations of PO2 and PCO2 were not significantly different from the sum of individual oscillations to alternations of PCO2 and of PO2 alone. This was true with respect to timing and to amplitude of the oscillation. 6. Usually the amplitude of the chemoreceptor discharge oscillation in response to an asphyxial alternation was greater than the amplitude of the oscillation to either its PCO2 or its PO2 component alone. However, at the highest frequencies used, the phase relation between the PCO2 and PO2 components of the response could lead to the summed asphyxial response being less than its individual components. 7. The amplitudes and shapes of the oscillations in response to 4 s PCO2 alternations were not affected by changing either the steady-background PO2 or PCO2, but the amplitudes of the oscillations to pure PO2 alternations were enhanced by hypoxia and by hypercapnia. The importance of PO2 and PCO2 in giving rise to the natural respiratory oscillations in chemoreceptor discharge depends on the mean levels of the two gases. In normocapnic hypoxia (PO2 ca. 50 Torr) they are equally important but when PO2 is raised it becomes less important.

Action Potentials↗
PubMed1988

Effects of potassium, oxygen and carbon dioxide on the steady-state discharge of cat carotid body chemoreceptors.

1. We have studied the effects of intravenous infusions of 0.1 mmol/min KCl (raising arterial potassium from ca. 3.2 to 6.0 mM) on the steady-state responses of carotid body chemoreceptors to end-tidal PCO2 and PO2 in the pentobarbitone-anaesthetized cat. 2. The excitatory effect of these KCl infusions was enhanced by hypoxia and reduced or abolished by hyperoxia. 3. Hypercapnia did not enhance, and usually reduced, excitation by KCl. 4. When similar control discharge frequencies were established by hypoxia or by hypercapnia, a KCl infusion excited the hypoxic discharge by about twice as much as it did the hypercapnic discharge. 5. These observations are not inconsistent with the idea that the mechanism underlying hypoxic excitation of arterial chemoreceptors is one that controls extracellular potassium concentration near the afferent nerve ending. 6. Insofar as potassium-induced excitation of chemoreceptor discharge is abruptly reduced by hyperoxia it behaves like Asmussen and Nielsen's postulated 'anaerobic work substance' and it may therefore contribute to the increased importance of the arterial chemoreflex reported in exercise.

Action Potentials↗
PubMed1988

Calcium transport properties of cardiac sarcoplasmic reticulum from cardiomyopathic Syrian hamsters (BIO 53.58 and 14.6): evidence for a quantitative defect in dilated myopathic hearts not evident in hypertrophic hearts.

Calcium uptake was measured in homogenates and microsomal preparations enriched in sarcoplasmic reticulum vesicles isolated from hearts of hypertrophic (BIO 14.6) and dilated (BIO 53.58) cardiomyopathic as well as control (F1B) Syrian hamsters at 3, 7, 9, and 11 months of age. Calcium uptake studies were done using the Millipore filtration technique under conditions known to restrict transport to the sarcoplasmic reticulum. Steady-state calcium uptake capacity was used as a measure of the relative amounts of sarcoplasmic reticulum in homogenates prepared from individual hearts. At 3 months of age, there were no differences in calcium uptake in homogenates from control or myopathic hearts. However, by 9 months, although calcium uptake of homogenates from control and hypertrophic hearts was the same, calcium uptake by homogenates from dilated hearts was significantly depressed both in initial rate and capacity. Similar trends were seen in the microsomal vesicle preparations, but the decrease in calcium uptake in the dilated hearts was significantly lower by 3 months of age. The catalytic activity of the sarcoplasmic reticulum transport enzyme was estimated from the ratio of velocity to capacity, which provides a measure of the fractional rate of filling of the sarcoplasmic reticulum with calcium. The velocity-to-capacity ratios were not different at any of the ages in both the homogenate and microsomal preparations. The results of this study demonstrate that a major defect in the dilated cardiomyopathy may be due to a decrease in the volume or number of sarcoplasmic reticulum calcium transport sites rather than a decrease in specific activity of the transport enzyme.

Algorithms↗
PubMed1988

Cardiovascular complications of aluminum phosphide poisoning.

Aluminum phosphide is widely used as a grain preservative. Recently some reports have appeared in the literature in which serious toxic effects of this agent have been reported, and a number of fatal complications, including shock and cardiac dysrhythmias, have been increasingly seen. Of 25 cases of aluminum phosphide poisoning the authors observed over a period of two years, 16 cases (64%) had evidence of cardiac dysfunction. Despite adequate treatment, 40% of the patients died. A plea is being made for recognition of these fatal complications and for early institution of adequate treatment.

Adult↗
PubMed1988

Allergic rhinitis relieved by aspirin and other nonsteroidal antinflammatory drugs.

Aspirin and other non-steroidal antiinflammatory drugs (NSAIDS) are known to cause urticaria and aggravate symptoms of bronchial asthma. This report describes a patient with allergic rhinitis whose symptoms were improved after ingestion of aspirin and the NSAIDS. The beneficial effect was confirmed by oral double-blind challenges.

Administration, Oral↗