Search PubMed⌕ Search

Biomedical subjects

K Khan

Publications and source records attributed to K Khan.

At least 91 records · Page 5Linked to original sources
PubMed1996

The effect of structured versus conventional inhaler education in medical housestaff.

Despite the importance of adequate inhaler technique in the care of asthma and chronic obstructive pulmonary disease, physicians have often been shown to have poor knowledge of correct inhaler use. At present, postgraduate teaching programs appear to leave physicians to acquire inhaler handling skills informally in the context of day-to-day patient care. We undertook the present study to determine if one brief structured educational intervention would be adequate to teach postgraduate physicians inhaler skills that would be retained over long periods of time. We also compared the efficacy of this intervention to traditional education methods. We recruited 52 postgraduate trainees in internal medicine at a large university hospital; 26 were in the educational intervention group and 26 were in the control group. Physicians in the intervention group were asked to respond to a questionnaire on inhaler use and to demonstrate the correct use of a metered-dose inhaler (MDI), an MDI with a pacing chamber and a multidose dry-powder inhaler. These intervention subjects were then instructed on proper inhaler usage by a qualified nurse educator. Eight months later, testing was repeated in the intervention group and was undertaken in the control group. Questionnaire scores were significantly higher in the intervention group at the 8-month follow-up than at baseline (59% vs. 42%; p < 0.05). Similarly, the scores of the intervention group at follow-up were significantly higher than those of the control group (59% vs. 39%; p < 0.05). There was no significant difference between the baseline scores of the intervention group and those of the control group. The mean demonstration score was significantly higher in the intervention group at follow-up than at baseline (68% vs. 39%; p < 0.001) and was also higher than that of the control group (68% vs. 44%; p < 0.001). There was no significant difference between the scores for all devices between the intervention group before education and the control group. Our data show that one brief teaching session is sufficient to produce a sustained improvement in knowledge and handling of inhalers by postgraduate physicians. The knowledge and skills of the physicians educated in our study were not only better than before they had received instruction, but were better than the knowledge and skills of postgraduate trainees from the same institution who had received no formal training. This latter observation suggests a failure of traditional unstructured postgraduate training programs to teach this practical patient care skill.

Asthma↗
PubMed1996

Open label trial of the efficacy and tolerability of Lamisil (Terbinafine) 500 mg once daily in the treatment of onychomycosis due to candida.

An open label trial of Lamisil (Terbinafine) 500 mg daily for 16 weeks was conducted on 20 patients with Onychomycosis due to candida. Of these, 15 patients could complete the trial. Total number of target nails infected was 21. The follow-up period was from 16 to 52 weeks. At 16 weeks, 71% cases showed clinical improvement and 67% had mycological cure. Thirty-three percent had complete cure at 52 weeks. The results show that Terbinafine is effective against candida but requires a longer duration of treatment. The drug was well tolerated.

Adult↗
PubMed1995

Haemodynamic responses in muscle and adipose tissue and whole body metabolic responses during norepinephrine infusions in man.

Circulatory metabolic and cardiovascular responses to 1-h-long infusions of norepinephrine (NE) (approx. 0.2 and 0.4 nmol/kg body weight per min) were measured on two separate occasions in six subjects. The infusions increased circulating NE concentrations 6- and 13-fold, respectively. Blood flow to adipose tissue, measured with the 133Xe clearance technique, increased from a basal value of about 3 ml/100 g per min, to about twice this value at 60 min with both doses of NE. In contrast muscle blood flow was unaffected. The higher dose of NE produced significant increments at 60 min in whole body oxygen consumption (approx. 9%), and circulating concentrations of glucose (approx. 18%), non-esterified fatty acids (approx. 200%) and glycerol (approx. 32%) which were greater than those observed with the low-dose infusion. Changes in blood pressure, pulse and CO2 exchange were observed within 5-10 min after the start of the infusion, whilst changes in adipose tissue blood flow were observed after 15-30 min. It is concluded that in humans (i) a dose of NE as low as 0.2 nmol/kg per min is sufficient to evoke both circulatory and metabolic responses; (ii) the pattern in the adipose tissue blood flow response to NE may help explain some of the conflicting reports about the haemodynamic effects of this hormone in adipose tissue; and (iii) blood flow and vascular resistance in different tissues may be affected in different ways by norepinephrine.

Adipose Tissue↗
PubMed1995

Intestinal site-dependent susceptibility to chronic indomethacin in the rat: a morphological and biochemical study.

BACKGROUND: The cyclo-oxygenase inhibitor indomethacin induces a pattern of gastrointestinal injury in the rat that is site-dependent. This study compared the extent of injury to different regions of the rat intestine (small intestine, caecum and colon) with the corresponding changes in arachidonic acid metabolism in these areas, following long-term, low-dose indomethachin. METHODS: Rats (eight per group) received either indomethacin (3 mg.kg/day) or control diet for either 6 or 12 weeks. At termination animals were bled, examined both macroscopically and microscopically for ulcers, and assayed for blood thromboxane B2, intestinal tissue prostaglandin E2 content and production of leukotriene B4. In a further eight animals luminal indomethacin concentrations from the small intestine, caecum and colon were measured following 6 weeks of chronic drug ingestion. RESULTS: At 6 weeks, macroscopic ulcers were observed in 2/8 (small intestine), 3/8 (caecum) and 1/8 (colon) animals. The corresponding ratios at 12 weeks were 5/8, 8/8 and 0/8. In control animals, a site-dependent gradient of the prostaglandin E2 concentration was found. In indomethacin-dosed animals the intestinal prostaglandin E2 content was reduced significantly in the caecum at 6 weeks, and in all tissues at 12 weeks. An increased leukotriene B4 production was observed in the caecum only, at 12 weeks (P < 0.01), and the blood thromboxane B2 was reduced at both time points (P < 0.05). CONCLUSION: There is a site-dependent gradient of the prostaglandin E2 concentration in the rat intestine. The rat caecum is particularly sensitive to long-term low-dose indomethacin, both in terms of chronic intestinal inflammation and changes in prostanoid metabolism. This site-dependent degree of injury may be associated with a local cyclo-oxygenase inhibition.

Animals↗
PubMed1995

Overuse injuries in classical ballet.

Successful management of classical ballet dancers with overuse injuries requires an understanding of the art form, precise knowledge of anatomy and awareness of certain conditions. Turnout is the single most fundamental physical attribute in classical ballet and 'forcing turnout' frequently contributes to overuse injuries. Common presenting conditions arising from the foot and ankle include problems at the first metatarsophalangeal joint, second metatarsal stress fractures, flexor hallucis longus tendinitis and anterior and posterior ankle impingement syndromes. Persistent shin pain in dancers is often due to chronic compartment syndrome, stress fracture of the posteromedial or anterior tibia. Knee pain can arise from patellofemoral syndrome, patellar tendon insertional pathologies, or a combination of both. Hip and back problems are also prevalent in dancers. To speed injury recovery of dancers, it is important for the sports medicine team to cooperate fully. This permits the dancer to benefit from accurate diagnosis, technique correction where necessary, the full range of manual therapies to joint and soft tissue, appropriate strengthening programmes and maintenance of dance fitness during any time out of class with Pilates-based exercises and nutrition advice. Most overuse ballet conditions respond well to a combination of conservative therapies. Those dancers that do require surgical management still depend heavily on ballet-specific rehabilitation for a complete recovery.

Ankle Injuries↗
PubMed1994

Microvascular replantation of a completely avulsed scalp.

Total scalp avulsion is an unusual injury. To obtain good functional and cosmetic results, immediate revascularization using microsurgical techniques and replacement of the scalp in the correct anatomical position is the procedure of choice. This article describes a case report of successful replantation of a totally avulsed scalp from a 26-year-old male. Bilateral superficial temporal vessel anastomoses were performed using reversed autologous long saphenous vein grafts on the right side and direct repair on the left. Points of technique are discussed and the literature is reviewed.

Accidents, Occupational↗
PubMed1994

Results of clinical assessment after primary digital nerve repair.

We have carried out a retrospective study of 88 consecutive digital nerve repairs in 84 patients who presented to this department between September 1989 and September 1991. 94% of the patients were operated on within 24 hours of the injury, and the nerves were repaired using magnifying loupes (x 4.5) 71 patients were assessed clinically 8 to 32 months post-operatively. 17% of the patients had excellent results, 51.1% good results, 22.8% fair results and 9.1% had poor results. Close correlation between age and recovery of sensation and between smoking and nerve recovery were found. Results were better in nerves that were cut cleanly (64.3% were excellent/good) than in crushed nerves (28.1%). Without the availability of an operating microscope, loupes give a satisfactory result in nerve repair, and this study compares well with reported series.

Adolescent↗
PubMed1994

Effect of noradrenaline on glycerol turnover and lipolysis in the whole body and subcutaneous adipose tissue in humans in vivo.

1. The effect of infusion of noradrenaline (0.42 mumol min-1 kg-1) on the exchange of nonesterified fatty acids, glycerol and other metabolites across subcutaneous abdominal adipose tissue was investigated in five healthy subjects using an arteriovenous catheterization technique and measurement of adipose tissue blood flow using the 133Xe clearance technique. At the same time, the net rate of fat oxidation in the whole body was assessed by indirect calorimetry, and the turnover of glycerol in the whole body and in subcutaneous adipose tissue was estimated using [5-2H]glycerol, which was administered as a primed constant infusion for 1 h before (basal turnover) noradrenaline administration and continued during the 1 h of noradrenaline infusion. 2. The noradrenaline infusion increased the plasma noradrenaline concentration from a basal value of 0.9 +/- 0.1 to 12.6 +/- 1.2 nmol/(mean +/- SEM) at 60 min. It also increased the arterialized concentration of glycerol by 50% (basal value 81 +/- 11 mumol/l-1) and that of plasma non-esterified fatty acids three-fold (basal value 357 +/- 86 mumol/l). 3. Noradrenaline increased the net release of glycerol by adipose tissue three-fold and that of non-esterified fatty acids three- to four-fold. Although the ratio of non-esterified fatty acid to glycerol release by adipose tissue increased in all subjects from a mean value of 2.7 in the basal period to 3.6 and 3.9 at 50 and 60 min of the noradrenaline infusion, respectively (P < 0.02), at no time point did the ratio differ significantly from 3.0.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed1994

The effect of arterialization of blood by hand warming on the interpretation of forearm metabolic studies.

Although sampling of arterialized blood is widely used as an alternative to arterial sampling in metabolic studies, the arterialization procedures have been criticized because they may produce metabolic and haemodynamic effects that confound interpretation of results, especially in studies involving arteriovenous exchange of metabolites across the contralateral forearm. This study aimed to assess the effect of warming the hand for 10 or 20 min (a procedure which may be used to arterialize superficial venous blood) on the blood flow to the skin and muscle of the whole of the contralateral forearm. Hand warming, produced by placing the hand in a box kept at 67 +/- 3 degrees C for 10 min (standard errors of mean, SEM), produced no significant change in the blood flow of the whole forearm (4.14 +/- 0.28 versus 4.34 +/- 0.26 ml per 100 ml forearm min-1, measured with the hand circulation occluded), muscle (1.9 +/- 0.12 versus 1.82 +/- 0.15 ml per 100 ml forearm min-1, measured by 133Xe) or skin (5.2 +/- 4.0 versus 4.6 +/- 2.9 arbitrary units, measured by photoplethysmography). After 20 min of hand warming, there was no significant change in the concentration of a variety of metabolites in the deep venous blood draining the contralateral forearm. It is concluded that, unlike other 'arterialization' procedures, that used in this study had no important effect on the blood flow to the contralateral forearm or its distribution between muscular and non-muscular tissues. Therefore, this procedure of arterialization can be employed in arteriovenous studies that aim to assess the exchange of metabolites between blood and forearm tissues.

Adult↗
PubMed1994

Measles virus induction of human endothelial cell tissue factor procoagulant activity in vitro.

Measles virus infection of microvascular endothelium in vivo and ensuing endothelial cell activation may be important in the pathogenesis of subsequent inflammation in target organs. This study investigated the capacity of measles virus to induce procoagulant activity, in vitro, in endothelial cells isolated from human umbilical cord veins. Endothelial cells were infected with a clinical isolate of measles virus propagated in Vero cells. Cells were also incubated with bacterial lipopolysaccharide (10 micrograms/ml), herpes simplex virus type 1, cytomegalovirus or culture medium alone as positive and negative controls, respectively. Endothelial cell procoagulant activity was measured in a one-stage clotting assay. Measles virus stimulated both a time and dose-dependent endothelial cell procoagulant response by the induction of tissue factor synthesis, confirmed by both immunocytochemistry and its dependence on factor VII for activity. This activity was reduced by u.v.-irradiation of the virus. Infected cells were analysed by double immunofluorescent staining for both tissue factor and measles virus N-protein, and examined using confocal scanning laser microscopy. Cells expressing tissue factor were also positive for the measles virus N-protein. Low levels of interleukin-1 were detected in some viral inocula derived from measles virus-infected Vero cells, however neutralising antibody to interleukin-1 failed to inhibit the endothelial cell procoagulant response to measles virus, whereas it significantly reduced procoagulant activity induced in endothelial cells by recombinant interleukin-1. The capacity of measles virus to induce endothelial tissue factor in vitro, may be relevant to the thrombotic vasculopathy associated with measles virus infection in vivo.

Animals↗
PubMed1994

Muscle and whole body metabolism after norepinephrine.

The effect of an infusion of norepinephrine (0.42 nmol.kg-1.min-1) on energy metabolism in the whole body (using indirect calorimetry and the arteriovenous forearm catheterization techniques in eight healthy young male adults. The activity of the triglyceride-fatty acid cycle, which mainly operates in nonmuscular tissues, was also assessed by measuring glycerol turnover using [2H5]glycerol (to indicate lipolysis) and indirect calorimetry (to indicate net fat oxidation). Norepinephrine increased whole body oxygen consumption by almost 10% (P < 0.01), but the estimated oxygen consumption of muscles tended to decrease. Muscle blood flow (measured by 133Xe) and forearm blood flow (measured by strain-gauge plethysmography) were not significantly affected by norepinephrine, but the rate of uptake of nonesterified fatty acids and beta-hydroxybutyrate increased severalfold (P < 0.05), whereas that of glucose did not. The activity of the triglyceride-fatty acid cycle increased fourfold after norepinephrine administration, having a marginal effect on resting energy expenditure (approximately 1.5%) but accounting for approximately 15% of the increase in whole body energy expenditure. This study provides no evidence that skeletal muscle is an important site for norepinephrine-induced thermogenesis and suggests that an increase in the activity of the triglyceride-fatty acid cycle contributes to the norepinephrine-induced increase in energy expenditure of nonmuscular tissues.

Adult↗
PubMed1993

Glycerol exchange across the human forearm assessed by a combination of tracer and arteriovenous exchange techniques.

1. Whole-body kinetics and regional exchange of glycerol across forearm muscle were assessed in eight lean subjects by a combination of a tracer method (infusion of [2H5]glycerol) and arteriovenous catheterization. 2. During an apparent steady state, the enrichment of glycerol in deep venous blood from the muscle bed of the forearm was about half (4.40 +/- 1.72 atom per cent excess) that observed in arterialized blood (8.41 +/- 4.30 atom per cent excess). Under the same conditions, the circulating concentrations of glycerol in arterialized (91 +/- 24 mumol/l) and venous (87 +/- 32 mumol/l) blood were similar. 3. In a further group of 37 subjects it was found that about half had a positive arteriovenous concentration difference and the other had half a negative arteriovenous concentration difference (mean -1.6 +/- 11.9 mumol/l; range -25 to +22 mumol/l). 4. These results suggest: (a) that human muscle does not always release glycerol and may take it up; (b) that there is substantial isotopic exchange of glycerol across forearm muscle tissue, which is not reflected by the net exchange of glycerol; this could be due to slow equilibrium of enriched glycerol from the circulation, with unenriched free glycerol in the muscle pool, or due to the simultaneous metabolic utilization of enriched glycerol and metabolic production of unenriched glycerol; (c) that the estimation of glycerol flux rates is strongly dependent on whether the blood is arterialized or deep venous.

Adult↗
PubMed1993

Bryostatin 1-induced modulation of the acute lymphoblastic leukemia cell line Reh.

We have previously reported that the phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA) induces further differentiation of the human acute lymphoblastic leukemia cell line Reh to a monocytoid B lymphocyte stage. In the present study, we investigated the differentiating capacity of another protein kinase C (PKC) activator, bryostatin 1 (bryo). Reh cells were treated in vitro with TPA, bryo, or interferon-alpha (IFN-alpha) for a period of 5 days during which cells were analyzed for changes in growth patterns, morphology, cytochemistry, and surface phenotype. Bryo caused a dose-dependent growth inhibition of Reh cells. Morphologically, the treated cells expressed monocytoid features with development of filopodia and numerous vacuoles indicating phagocytic activity. Bryo induced similar phenotypic changes to TPA, including induction of CD11c, increased expression of CD22 and down-regulation of CD10 and CD19. Enzymatically, bryo, like TPA, induced tartrate-sensitive acid phosphatase expression but failed to induce periodic acid Schiff (PAS) and nonspecific esterase (NSE). Bryo inhibited the TPA action on NSE and CD10. IFN-alpha showed additive growth inhibitory and phenotypic effects to bryo. Collectively, our findings indicate that bryo is capable of inducing further differentiation of the Reh cells along the B cell lineage similar to those of TPA.

Acid Phosphatase↗
PubMed1993

The independent metabolic effects of halothane and isoflurane anaesthesia.

Twelve healthy, unpremedicated women scheduled for total abdominal hysterectomy were given either isoflurane (n = 6) or halothane (n = 6) anaesthesia. They all received general anaesthesia for a period of 3 h, with surgery being carried out only in the last hour. The anaesthesia consisted of thiopentone, pancuronium and a mixture of oxygen-enriched air (FiO2 = 34%) supplemented with 1 MAC of either isoflurane or halothane. The patients were maintained normothermic, and with an arterial SaO2 above 95% throughout the period of the study. The following measurements were made before, during and after anaesthesia (with and without surgery): oxygen consumption (VO2), carbon dioxide production (VCO2); circulating concentrations of various hormones (insulin, growth hormone and cortisol); various metabolites; selected amino acids and albumin; forearm arterio-venous concentration difference of glucose, lactate, free fatty-acids and selected amino acids (four patients in each group). Whole body VO2 decreased significantly by over 20% during anaesthesia (with or without surgery), P < 0.05). Although the circulating concentration of most amino acids showed little or no change during anaesthesia alone, there was a tendency for the flux of most metabolites to decrease, and this persisted during surgery (P < 0.05). During anaesthesia alone there was a twofold reduction in the plasma cortisol concentration (P < 0.05), and a decrease in albumin concentration (P < 0.01). With the onset of surgery, plasma cortisol concentration increased rapidly (in association with several other hormones and metabolites) but hypoalbuminemia persisted.

Adult↗