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Biomedical subjects

K Patel

Publications and source records attributed to K Patel.

At least 289 records · Page 16Linked to original sources

Acidic phospholipases in cultured human fibroblasts: deficiency of phospholipase C in Niemann-Pick disease.

Radioactive phosphatidyl choline substrates specifically labeled in the one position or two position fatty acid were used to establish conditions for the detection of acidic phospholipase A1, A2 and C activities in extracts of cultured human fibroblasts. Maximal activity was detected at a pH of 3.0, 4.0 and 5.0 respectively, suggesting that the enzymes are of lysosomal origin. None of the activities were stimulated or inhibited markedly by Ca2+ or EDTA. The A1 and A2 activities, but not the C activity, were inactivated by the sulfhydryl reactive Ellman reagent. All three enzyme activities were in the normal range for cultured fibroblasts which were deficient in acid lipase, indicating that these activities are not attributable to the acid lipase gene product. Phospholipase A activity was deficient in fibroblast extracts from patients with Niemann-Pick disease, types A, B and C. These data suggest either identity or a genetic relationship between sphingomyelinase and phospholipase C. The activities examined were within the normal range in fibroblasts from patients with neuronal ceroid lipofuscinosis, sea blue histiocyte disease and selected uncharacterized degenerative diseases.

Calcium↗

Juvenile rheumatoid arthritis. A comparison of patients from the USSR and USA.

Juvenile rheumatoid arthritis (JRA) in the Union of Soviet Socialist Republics (USSR) and the United States (USA) shows a remarkable similarity in age of disease onset, subtype onset, frequency, and most laboratory measurements. There is variation in the therapeutic approach with heavier reliance on aspirin in the USA. The evolution of JRA from onset subtype to final subtype over 5 years was the same in both groups and was independent of the type of therapy.

Adrenal Cortex Hormones↗

Variability in gas production by Escherichia coli in enrichment media and its relationship to pH.

Variability in gas production in multiple subcultures of Escherichia coli was assessed in two selective enrichment media and in lactose peptone water. Considerable variability occurred with all media at 37 and 44 degrees C. Addition of buffer increased gas production and decreased variability. The relationships between pH, growth, and gas production were complex. In buffered media, viable counts increased by 269 x 10(6) to 382 x 10(6)/U of pH fall, whereas in unbuffered media, they increased by 9.45 x 10(6) to 30.37 x 10(6)/U of pH fall. In buffered and unbuffered media, pH fell as gas production rose. However, variability in gas production among individual subcultures was not associated with changes in pH.

Bacteriological Techniques↗

Prevention of nitroprusside-induced cyanide toxicity with hydroxocobalamin.

To investigate hydroxocobalamin's role in preventing cyanide intoxication from sodium nitroprusside, we studied two groups of patients. One group received nitroprusside alone, and the other received nitroprusside and hydroxocobalamin. Red-cell and plasma cyanide levels were 83.44 +/- 23.12 and 3.51 +/- 1.01 microgram per 100 ml after nitroprusside alone and were 33.18 +/- 17.29 and 2.18 +/- 0.65 microgram per 100 ml after nitroprusside plus hydroxocobalamin. Acidosis developed in patients with red-cell cyanide levels higher than 75 microgram per 100 ml. When hydroxocobalamin infusion was stopped before sodium nitroprusside infusion was discontinued, blood cyanide levels and base deficit increased in a manner similar to that in the untreated group. The dose of nitroprusside used in each group did not differ statistically. These data show that hydroxocobalamin prevents cyanide transfer from red cells and plasma to tissue after nitroprusside metabolism, and thereby prevents cyanide toxicity from large intravenous doses of the drug.

Adult↗

Interpretation of increases in the transfer coefficient for carbon monoxide (TLCO/VA or KCO).

During a 15-month period, 27 patients were seen in a routine clinical pulmonary function laboratory in whom the transfer coefficient (TLCO/VA or KCO), measured by the single breath technique, was increased. Pulmonary haemorrhage accounted for two-thirds of the cases; in them sequential measurements of KCO were able to monitor the onset and cessation of bleeding. In the remaining cases the cause of the increase in KCO remains uncertain. All patients had a reduction in vital capacity. Experiments in six normal subjects showed that KCO rose as the breath-holding lung volume was reduced, but that this was insufficient to account for the raised KCO in patients with reduced volumes. Partitioning of the two components of TLCO at different lung volumes in three normal subjects showed that an increase in pulmonary capillary blood volume per unit alveolar volume was chiefly responsible for the increase of KCO in normal subjects at lower lung volumes. The membrane diffusing capacity changed less than predicted per unit volume, suggesting that the thickness of the air-blood barrier remains fairly constant as the lung expands or contracts.

Adult↗

Airway hyperreactivity and peripheral airway dysfunction in influenza A infection.

We studied 39 consecutive college students with documented nonpneumonitic influenza A/Victoria/3/75/H3N2 infection to examine alterations in pulmonary mechanics and airway reactivity to cholinergic challenge, and to assess the effect of the antiviral agent amantadine on these changes. Thirty-six of the 39 subjects (92 per cent) demonstrated diminished forced flow rates and decreased density-dependent forced flow rates while breathing a helium-O2 mixture as compared to an air mixture. On initial evaluation, there was no significant difference in forced flow rates or density dependence between a group of 18 subjects treated with amantadine and 21 subjects given a placebo. However, the placebo group demonstrated further decreases in density dependence 7 days after initial presentation, whereas the amantadine group demonstrated a significant increase in density dependence (P less than 0.05), which suggested an accelerated improvement in peripheral airway dysfunction in the treated group. After inhalation of carbachol aerosol, 25 subjects showed a significant (P less than 0.05) increase in total respiratory resistance that was prolonged and independent of hay fever history. Airway hyperreactivity gradually diminished during a 7-week period in both groups. There was no significant difference in the initial degree of hyperreactivity or in the rate of improvement between groups. These data suggest that nonpneumonitic influenza infection may be associated with both an inflammatory response predominantly in the peripheral airways and transient bronchial hyperreactivity. By means of its antiviral effect, amantadine may arrest the proliferation of virus and associated inflammatory response in peripheral airways, but airway hyperreactivity presumably related to initially damaged airway depithelium is not attenuated by inhibition of viral replication after infection has been established.

Aerosols↗

Intracranial pressure changes induced by sodium nitroprusside in patients with intracranial mass lesions.

Because of the ability of sodium nitroprusside (SNP) to dilate cerebral blood vessels, intracranial pressure (ICP) should increase with its use. In patients with vascular intracranial tumors following SNP (0.01%) infusion, ICP increased from 14.58 +/- 1.85 to 27.61 +/- 3.33 torr (p greater than 0.0005) and cerebral perfusion pressure decreased from 89.32 +/- 3.5 to 43.23 +/- 4.60 torr (p less than 0.0005) when the mean arterial pressure had reduced by 33%. These results suggest that SNP not be used in patients with raised ICP unless previous measures have been taken to improve intracranial compliance.

Blood Pressure↗

The Rees system in infants: fresh gas flow and PaCO2.

Fresh gas flow from the anaesthetic machine can be set to determine the low level of PaCO2 that is achieved during anaesthesia using Rees variation of the T-piece. It does not however set the upper limits for PaCO2 which is more reliant upon the minute ventilation. For a PaCO2 of 40 mm Hg, it is suggested that the fresh gas flow from the machine be 220 cc/kg. For small infants, a higher flow rate is necessary.

Adolescent↗