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Biomedical subjects

F A Khan

Publications and source records attributed to F A Khan.

At least 145 records · Page 8Linked to original sources
PubMed1987

Ciprofloxacin increases serum levels of theophylline.

During a clinical trial of orally administered ciprofloxacin in respiratory tract infections, changes in serum theophylline levels were evaluated in 33 hospitalized patients who also required theophylline therapy. Patients received intravenous theophylline in standard titrated doses and 750 mg of oral ciprofloxacin twice daily. Serum theophylline levels in all patients were measured before and during ciprofloxacin therapy. The mean serum pretreatment theophylline level was 7.8 +/- 4.6 micrograms/ml; during ciprofloxacin therapy, the level increased to 14.6 +/- 7.4 micrograms/ml. Twenty of the 33 (61 percent) patients evaluated had increases in serum theophylline levels by a mean value of 10.5 micrograms/ml. In 30 percent of patients who experienced increases, theophylline concentrations were in the toxic range. This occurred more frequently in elderly patients with chronic obstructive pulmonary disease. In light of the frequency and potential severity of this interaction, careful monitoring of serum theophylline levels in patients receiving theophylline and ciprofloxacin is recommended.

Administration, Oral↗
PubMed1987

Atypical forms of spinal tuberculosis.

Twenty-three patients with atypical forms of spinal tuberculosis treated between 1975 and 1985, are described. All presented with signs and symptoms of compression of the spinal cord or cauda equina, ranging from paraesthesiae and increasing weakness of extremities to paraplegia and loss of sphincter control. None of them showed visible or palpable spinal deformity nor the typical radiographic appearance of destruction of the intervertebral disc and the two adjoining vertebral bodies. These atypical forms constituted about 12 percent of all the cases of spinal tuberculosis seen (a total of 190 cases); and fell into three well-defined groups: those with the involvement of neural arch only; those with the involvement of a single vertebral body; and, those without bony involvement. The correct surgical approach in these groups was found to be different: spinal cord compression caused by the tuberculous disease of the neural arch was best treated by laminectomy; whereas single vertebral body disease required an anterior or anterolateral approach. Spinal computerized tomography was helpful in defining the extent of disease and planning the surgical approach. Histological confirmation of tuberculosis was obtained in all the cases and acid fast bacilli (A.F.B.) were found in, and cultured from, the biopsy specimens of 18 cases.

Adolescent↗
PubMed1987

The influence of Bavistin and Calixin on CO2-evolution and the major nutrient status (NPK) of the soil.

An application of Bavistin (5 mg kilogram of soil) and Calixin (1.5 mg per kilogram of soil) significantly enhanced the microbial activity, as well as availability, of NH(4)(+)-N and P in the soil, while NO(2)(-)-NO(3)(-)-N and available K were found to decrease. During incubation, decreases in CO(2)-evolution were observed initially up to 21 days, with an increase up to 42 days, and, thereafter, a fall in both treatments.

Journal Article↗
PubMed1987

Ion flux and Na+,K+-ATPase activity of erythrocytes and leucocytes in thyroid disease.

In hyperthyroidism, erythrocytes show decreased Na+,K+-ATPase activity, decreased [3H]ouabain binding capacity (an index of the number of sodium pumps) and decreased active sodium and potassium flux rates, with a high intracellular sodium concentration. As erythrocytes are non-nucleated and atypical cells, we have studied electrolyte status in thyroid disease using mixed leucocytes as well; the results obtained differed from those in erythrocytes. When compared with findings in healthy subjects, leucocyte Na+,K+-ATPase activity, [3H]-ouabain binding capacity, total and active rubidium (used instead of potassium) influx were all significantly increased in untreated hyperthyroidism and decreased in untreated hypothyroidism. In hyperthyroidism, there was also a decrease in plasma potassium, an increase in sodium efflux rate and efflux rate constant, but no significant changes in cell sodium and potassium concentrations. All these changes returned to normal in successfully treated patients. There was a significant correlation between these abnormalities of electrolyte status and thyroid disease status (as serum thyroid stimulating hormone and free thyroxine).

Adult↗
PubMed1987

Effects of continuous positive airway pressure in acute asthma.

We studied flow changes, airway pressures, breathing patterns and subjective sensation during tidal breathing on continuous positive airway pressure (CPAP) in 21 acutely ill asthmatic patients and 19 controls. The measurements obtained at various levels of CPAP were compared to the value at zero end-expiratory pressure. The fractional inspiratory time (TI/TTOT) was significantly reduced in both the patients and the control group (p less than 0.01). Patients noticed the best sensation of comfort at CPAP of 5.3 +/- (SD) 2.8 and the control group at 1.6 +/- 2.5. We noted a reduction in peak tidal expiratory flow and an increase in late-phase expiratory flow during tidal breathing in both groups although these changes were not statistically significant. There was improvement in sensation of comfort during low to medium levels of CPAP in acutely ill asthmatics. We conclude that low to medium levels of CPAP may be beneficial in acute asthma by assisting inspiratory muscles. As CPAP is increased, the beneficial effects of increased end-expiratory flow rate may be offset by the reduction in peak tidal expiratory flow rates.

Adult↗
PubMed1987

Effect of short term triiodothyronine administration on human leukocyte Rb(K) influx and Na efflux.

The effect of short term T3 administration on leukocyte ouabain-sensitive 86Rb(K) influx and Na efflux in normal subjects was investigated. At a dose of 60 micrograms daily for 7 days, T3 induced a significant increase in leukocyte 86Rb(K) influx and a significant fall in plasma K concentrations. Plasma and intracellular Na concentrations did not change. [3H]Ouabain binding, a measure of Na-K ATPase units, did not change. A week after T3 administration, 86Rb(K) influx, Na efflux, and plasma K concentrations were normal. In a series of five hyperthyroid patients, both ouabain-sensitive 86Rb influx and [3H]ouabain binding were significantly greater than in normal subjects. We conclude that T3 stimulates 86Rb(K) influx and Na efflux by leukocytes in vivo independently of [3H]ouabain binding and that this increase is rapidly reversible. However, in hyperthyroid patients both 86Rb influx and [3H]ouabain binding are increased, probably due to prolonged exposure to thyroid hormone excess.

Adult↗
PubMed1987

Utility of radiography and clinical features in the diagnosis of community-acquired pneumonia.

This article reviews the approach to the differential diagnosis of community-acquired pneumonia using clinical clues and radiography. Evidence is reviewed that indicates that the etiology of such pneumonias is changing. The basic clinical patterns, including bacterial, nonbacterial, and mixed presentations are discussed, as well as how aspiration, diabetes, and alcoholism affect the differential diagnosis.

Adult↗
PubMed1987

Pulmonary infections in AIDS.

Based on our experience, we would like to offer a few pragmatic suggestions for the practicing clinician. These recommendations are summarized in Tables 1 and 2. The first encounter with most patients gives the impression of either a dramatic acute infection, usually in the lungs, central nervous system, or gastrointestinal tract (in this order of frequency), or that of a chronic wasting disease. The former is frequently superimposed on the latter. The exploration of AIDS risk factors and a few easily detectable physical signs are the most important clues to the correct clinical diagnosis. Once AIDS is suspected, an aggressive and rapid approach for diagnosis is justified. Selected individually for each patient, the most commonly successful tests include bronchoscopy with BAL and/or transbronchial lung biopsy; bone marrow, lymph node, or liver biopsy with both microbiologic and pathologic processing of the material; blood (and often spinal fluid) cultures for fungal organisms; cranial computerized tomographic scan; and toxoplasma serology. Other tests, while potentially useful, are less important in immediate decision-making and treatment. In all cases of respiratory compromise or symptoms related to the chest, PCP has to be ruled out by invasive methods if the suspicion of AIDS is sufficiently strong. The diagnosis of one opportunistic infection should not be interpreted as a final answer. Rather, it should stimulate more vigilant efforts to uncover additional infections and other AIDS-related diseases if any abnormalities remain unexplained or persist despite treatment. Chest radiology should not be the main tool to diagnose or monitor lung infections.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1987

Management of presacral bleeding during rectal resection.

Severe presacral bleeding is a troublesome and potentially life-threatening complication during low anterior or abdominoperineal resection. We believe that suturing or cauterization should not be used since this will perpetuate the problem of bleeding in most instances. We recommend the use of hemostatic agents plus laparotomy sponges for compression to control the bleeding. If this fails, then the metallic thumbtack can be used as described herein. It is simple and effective.

Aged↗
PubMed1986

Complications of acute respiratory failure.

Many complications can occur during the management of acute respiratory failure and may involve multiple organs. Some of these complications can be avoided by preventive measures. We find evaluation of serial chest roentgenograms extremely useful for the early detection of several complications (figure 4). In addition, prophylactic use of heparin to prevent pulmonary emboli, prophylactic antacid or cimetidine therapy to prevent gastric bleeding, careful monitoring of renal function, appropriate measures to reduce the incidence of colonization and nosocomial infection, and early recognition of nosocomial infections are some of the measures essential to increased survival of patients with acute respiratory failure.

Acute Kidney Injury↗
PubMed1985

Optimal conditions for measurement of Na+,K+-ATPase activity of human leucocytes.

The Na+,K+-ATPase activity of human leucocytes was assayed by measuring the release of inorganic phosphate (Pi) from ATP. The maximum enzyme activity was achieved under the following conditions: concentration (mmol/l), Tris/HCl 50, Na 100, K 15, ATP 5, Mg 7, EDTA 1; pH 7.2 and temperature 37 degrees C, were optimal. Ouabain showed maximal inhibition at a concentration of 10-100 mumol/l. Ethanol, the solvent for ouabain, had a dose-related inhibitory effect. Heparin or citrate used as an anticoagulant gave similar results. Leucocyte samples could be stored at -20 degrees C for up to 6 days without loss of activity. Hypotonic lysis had advantages over sonication as the technique for cell disruption. The leucocyte Na+,K+-ATPase enzyme activity in healthy subjects was 186 mumol of Pi h-1g-1 of protein (median) with a range 136-243 mumol of Pi h-1g-1 of protein. The within-batch coefficient of variation was 6.4% and the between-batch precision was 9.6%.

Buffers↗
PubMed1985

Adrenaline and ion flux in isolated human leucocytes.

Hypokalaemia may be produced in man by intravenous adrenaline infusion, or as a result of pathological disturbances which have led to a high plasma adrenaline concentration. With isolated human leucocytes used as a cellular model, adrenaline at concentrations at and above 9 nmol/l increases the influx of rubidium (a model for potassium flux) into cells, with a simultaneous efflux of sodium. There is no effect on Na+,K+-ATPase activity in lysed leucocytes. Use of the adrenoceptor blockers timolol and atenolol shows that the demonstrated effect of adrenaline on coupled active transport of ions is mediated by beta 2-adrenoceptors.

Atenolol↗