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Biomedical subjects

A Khan

Publications and source records attributed to A Khan.

At least 271 records · Page 15Linked to original sources
PubMed1998

Effect of shoe insert construction on foot and leg movement.

PURPOSE: The purpose of this study was to quantify changes in foot eversion and tibial rotation during running resulting from systematic changes of material composition of five shoe inserts of the same shape. METHODS: Tests were performed with 12 subjects. The inserts had a bilayer design using two different materials at the top and bottom of the insert. The functional kinematic variables examined in this study were the foot-leg in-eversion angle, beta, and the leg-foot tibial rotation, rho. Additionally, the subject characteristics of arch height, relative arch deformation, and active range of motion were quantified. The statistical analysis used was a two way repeated measures MANOVA (within trials and inserts). RESULTS: The average group changes resulting from the studied inserts in total shoe eversion, total foot eversion, and total internal tibial rotation were typically smaller than 1 degree when compared with the no-insert condition and were statistically not significant. The measured ranges of total foot eversion for all subjects were smallest for the softest and about twice as large for the hardest insert construction. Thus, the soft insert construction was more restrictive, forcing all feet into a similar movement pattern, whereas the harder combinations allowed for more individual variation of foot and leg movement and did not force the foot into a preset movement pattern. The individual results showed substantial differences between subjects and a trend: Subjects who generally showed a reduction of tibial rotation with all tested inserts typically had a flexible foot. However, subjects who generally showed an increase of tibial rotation typically had a stiff foot. CONCLUSIONS: The results of this study suggest that subject specific factors such as static, dynamic, and neuro-physiological characteristics of foot and leg are important to match specific feet and shoe inserts optimally.

Adult↗
PubMed1998

Dependency and self-criticism in bipolar and unipolar depressed women.

OBJECTIVES: The dependency and self-criticism scores of women with histories of either unipolar disorder (N = 74) or bipolar disorder (N = 20) or no psychiatric history (N = 24) were compared to determine the influence of state depression on these personality dimensions. DESIGN: All women completed the Depressive Experiences Questionnaire and the Beck Depression Inventory. Patients were divided into currently depressed and remitted groups. RESULTS: Currently depressed women with unipolar disorder were more self-critical and dependent than non-psychiatric controls; women with unipolar disorder whose depression remitted were more self-critical only. Women in both the depressed and remitted bipolar groups were more self-critical than controls. Depressed bipolar patients did not differ from the controls in their level of dependency; remitted bipolar patients were significantly less dependent than controls. CONCLUSIONS: Dependency needs in depressed women are heavily influenced by mood state. Self-criticism appears to be a-characterological trait in both major depression and bipolar disorder. Women with bipolar disorder in remission report fewer dependency needs than women with no history of psychiatric disorder. The data provide partial support for Blatt's (1974) hypothesis that dependency and self-criticism reflect relatively stable personality dimensions in patients with a mood disorder.

Adult↗
PubMed1998

Glucose metabolism in Goto-Kakizaki rat islets.

Islets from Goto-Kakizaki (GK) rats from our colony, despite marked impairment of glucose-induced insulin release, used glucose and produced CO2 at a rate 3 times that of islets from control Wistar rats. Almost all glucose used was accounted for in CO2 and lactate production. The percentages of glucose carbon used collected in CO2 and lactate were similar for control and GK islets. GK islets also oxidized 40% more acetate and leucine to CO2 than did control islets. The fraction of carbon leaving the Krebs cycle relative to CO2 production was the same in GK and control islets. The capacities of mitochondria from GK islets to generate ATP from glutamate and malate were similar and that to generate ATP from succinate and rotenone was somewhat less from GK islets. The reason for the enhanced utilization of substrates by islets of the GK rat is not apparent. In conclusion, there is no decrease in islet glucose utilization, glucose oxidation, Krebs cycle function, or the electron transport system evident from these measurements to explain the impaired insulin release in islets from GK rats.

Acetates↗
PubMed1998

Diurnal and ultradian rhythmicity of plasma leptin: effects of gender and adiposity.

Plasma leptin shows a nocturnal rise and a pulsatile pattern. This work was undertaken to determine the effects of gender and obesity on this pattern. Twenty-four-hour leptin profiles were evaluated in 31 subjects [17 male, 14 female; age: 36 +/- 2 yr (mean +/- SEM); body mass index: 27.5 +/- 1.0 kg/m2]. Plasma leptin profiles were higher in obese (body mass index > 27 kg/m2) than in lean subjects and higher in women than in men, regardless of fat mass. Leptin showed diurnal rhythmicity with peaks between 2200-0300 (median: 0120) and nadirs between 0800 and 1740 (median: 1033). Spectral analysis revealed 2 components (periodicities: 24 and 12 h) with higher relative amplitudes in lean than in obese subjects. The relative diurnal amplitude also was higher in men than in women, controlling for adiposity. Insulinemia, female sex, and age were negative determinants of diurnal rhythm relative amplitude. Pulse analysis revealed 3.6 +/- 0.3 pulses/24 h, occurring mostly 2-3 h after meals. Pulse frequency correlated negatively with fat mass and insulinemia (Spearman's r = -0.54 and -0.37, respectively; P < 0.05 for each). Thus, obesity is associated not only with higher leptin levels but also with blunted diurnal excursions and dampened pulsatility. This abnormal rhythmicity may contribute to leptin resistance in obesity. The significance of the sexual dimorphism in the diurnal amplitude is unclear, but it may be related to leptin's putative role as a metabolic signal to the reproductive axis.

Adipose Tissue↗
PubMed1998

Long-acting inhaled beta2-agonists in asthma therapy.

OBJECTIVE: To review the pharmacology of the long-acting inhaled beta2-agonists, salmeterol and formoterol, summarize results of their clinical trials, evaluate their safety records, and discuss their roles in the treatment of asthma. DATA SOURCES: Preclinical and clinical studies involving salmeterol or formoterol were identified by a MEDLINE search, weekly computerized literature updates, and manual searches. Studies of satisfactory quality were chosen for review. DATA SYNTHESIS: Salmeterol and formoterol are potent and selective beta2-adrenoceptor agonists with durations of action >12 h. Their major differences are that formoterol has a rapid onset of action and is a partial agonist of high intrinsic efficacy, whereas salmeterol has a delayed onset and is a partial agonist of low intrinsic efficacy. Twice daily use of either drug results in improved lung function, reduced symptoms, and a better quality of life. These agents protect against exercise-induced asthma for 12 h and eliminate nighttime awakening in most patients. Limited tolerance develops, especially to their bronchoprotective effects, but their improvement of lung function is sustained. CONCLUSIONS: Regular use of salmeterol or formoterol provides subjective and objective amelioration of asthma in patients experiencing excessive symptoms or physiologic impairment despite the regular administration of low doses of inhaled corticosteroids (equivalent to approximately 500 microg/d of beclomethasone). Intermittent use of either long-acting beta2-agonist can provide prolonged protection against exercise-induced asthma or nighttime symptoms. Patients should be instructed to continue taking inhaled steroids when long-acting beta2-agonists are administered on a regular schedule and to not take long-acting beta2-agonists between regularly scheduled doses. Used properly, they are effective and safe adjunctive agents in the treatment of asthma.

Adrenergic beta-Agonists↗
PubMed1998

Physiological insulinemia acutely modulates plasma leptin.

Whether insulin acutely regulates plasma leptin in humans is controversial. We examined the dosage-response and time-course characteristics of the effect of insulin on leptin in 10 men (age 42+/-2 years [mean+/-SE]; BMI 29.3+/-2.0 kg/m2). Each individual underwent four 9-h euglycemic clamps (insulin at 20, 40, 80, and 400 mU x m[-2] x min[-1) and a control saline infusion. Although plasma glucose and insulin levels remained constant, leptin diminished from 9.1+/-3.0 to 5.9+/-2.1 ng/ml (P < 0.001) by the end of the control experiment. Conversely, plasma leptin showed a dosage-dependent increase during the insulin infusions that was evident within 30-60 min. The insulin-induced increase in leptin was proportionately lower in obese insulin-resistant men. Free fatty acids (FFAs) decreased during insulin and did not change during saline infusions. ED50 (the dose producing half-maximal effect) for insulin's effect on leptin and FFA was similar (138+/-36 vs. 102+/-24 pmol/l, respectively; P=0.11). To further define the role of physiological insulinemia, we compared the effect of a very low dosage insulin infusion (10 mU x m[-2] x min[-1]) with that of a control saline infusion in another group of 10 men (mean age 39+/-3 years; BMI 27.1+/-1.0 kg/m2). Plasma leptin remained stable during that insulin infusion, but fell by 37+/-2% in the control experiment. Thus physiological insulinemia can acutely regulate plasma leptin. Insulin could mediate the effect of caloric intake on leptin and could be a determinant of its plasma concentration. Inadequate insulin-induced leptin production in obese and insulin-resistant subjects may contribute to the development or worsening of obesity.

Adult↗
PubMed1998

Appendicitis: a continuing challenge.

Acute appendicitis is a common surgical emergency in urban setting, of a developing country. The computerised hospital patient database at Aga Khan University Hospital, Karachi, was utilised to obtain records of all adults with a histologically proven diagnosis of acute appendicitis. A review of patients treated over a 18 month period was undertaken. One hundred and three appendicectomies were performed for acute appendicitis during this period. The diagnosis was clinical in all cases. Investigations like leucocyte count and lower abdominal ultrasound scan were used to improve diagnostic accuracy without a clear advantage. A number of routine investigations like, haemoglobin estimation and urea, creatinine, electrolyte measurements, did not provide additional information. The duration of antibiotic treatment in acute simple appendicitis was empiric and could be reduced to a single preoperative dose. Peritoneal fluid culture studies had a poor yield (26%) and results were not found to effect management in acute simple appendicitis. The routine use of Ampicillin in all cases of bacterial peritonitis needs re-evaluation, as a high incidence (73%) of resistance was seen. Studies to define the role and duration of treatment, with a single antibiotic, in acute simple appendicitis should be undertaken. Acute appendicitis is probably the most frequently considered surgical differential diagnosis at any hospital dealing with acute surgical conditions. The established treatment continues to be surgical removal of the inflamed organ. The diagnosis and decision to operate both are accepted to be based on clinical judgement, though a number of investigative manoeuvres have been described to reduce the negative appendicectomy rate. Other areas of debate are the number and length of antibiotic treatment and use of bacterial culture studies in cases of simple acute appendicitis. To analyse present practice and identify areas for study and change, a retrospective study was undertaken at Aga Khan University Hospital (AKUH), Karachi.

Acute Disease↗
PubMed1998

Prevalence of dental caries in nursery school children of Akola city.

A study of prevalence and severity of dental caries was undertaken in seven nursery schools of Akola city in the age group of 5-6 years. A total of 508 children were examined out of which 288 were boys and 220 girls. The examination for dental caries and data collection was carried out as per W.H.O. (1987) criteria. Out of the total 508 children examined 61.41% were observed to be having caries with mean dmft/dmfs of 2.75+/-3.98 & 4.04+/-6.84 respectively. Total 17.91% school children were found to be having decay in either all upper or lower molars. In the high risk caries group 0.98% children were found to be affected with nursing caries and 0.2% children with rampant caries. Only a negligible proportion of filled teeth (1.42%) and missing due to caries (0.14%) was observed in the population. Occlusal surface caries was the most prevalent type of decay (44.71) and the mandibular deciduous second molars were the most affected by caries. Due to high prevalence of dental caries (61.41%) research must be carried out in the direction of identification of the children population at high risk of caries, so that a rigorous preventive programme be implemented.

Child↗
PubMed1998

Relationship between caries status, colony forming units (cfu) of Streptococcus mutans and Snyder caries activity test.

It is a well established fact that dental caries is caused by streptococcus mutans. For qualitative and quantitative analysis of streptococcus mutans, saliva samples are often preferred and are processed according to Kohler and Brathall method. In the present study an attempt is made to relate caries status (caries free, average caries, and rampant caries group) with cfu counts of streptococcus mutans and Snyder test. The streptococcus mutans were isolated using MSB agar and cfu were determined of each individual from different caries groups. The saliva of the same individual was drooled into a culture bottle containing Snyder test agar and extent of colour change was observed after 24, 48, and 72 hours incubated at 37 degrees C. The time and extent of colour change determined the conduciveness of diet. It has been observed that caries free individuals have low cfu count and their diet was mild or moderately conducive, while the individuals having average caries had medium cfu count and their diet was moderately-high conducive. In rampant caries, individuals however the cfu count were high and the diet was highly conducive. In caries free, average caries and rampant caries group 40, 60, and 80 per cent samples showed colour change, in Snyder test up to full length in 72 hours respectively. Thus a definite correlation exists between caries status, cfu count of streptococcus mutans and Snyder caries activity test.

Child↗
PubMed1998

Cathepsin B expression and its correlation with tumor-associated laminin and tumor progression in gastric cancer.

OBJECTIVE: Cathepsin B, a lysosomal cysteine proteinase, is associated with degradation of laminin. Its activity has been shown to be increased in gastric carcinomas. Laminin is one of the major components of basement membrane involved in cell-matrix interactions and tumor progression. The objectives of this study were to correlate cathepsin B expression in tumor cells with tumor-associated laminin and to further correlate the two with tumor progression. DESIGN AND SETTING: Resected gastric carcinomas (n = 29) taken from the surgical pathology files of the University of Massachusetts Medical Center, Worcester, were immunostained with cathepsin B and laminin using the avidin-biotin complex technique. Statistical analysis was performed using the exact linear by linear association test and exact Kruskal-Wallis test. Kaplan-Meier curves were plotted, and survival analysis was performed using a nonparametric log-rank test. RESULTS: Cathepsin B was expressed in 27 (93%) of 29 tumors (11 weak and 16 strong). Staining of tumor-associated laminin showed patterns ranging from almost continuous (n = 4) to moderately discontinuous (n = 11) and highly fragmented (n = 14). The degree of cathepsin B staining in tumor cells significantly correlated with the laminin distribution pattern (P = .0001). The association between increased cathepsin B, decreased laminin, and higher tumor stage was also significant. CONCLUSIONS: Increased cathepsin B expression by tumor cells associated with decreased tumor-associated laminin may suggest a mechanism for local tumor progression and metastasis. Staining for cathepsin B and laminin may be of prognostic value in gastric carcinomas.

Adenocarcinoma↗
PubMed1998

Cathepsin B and tumor-associated laminin expression in the progression of colorectal adenoma to carcinoma.

Cathepsin B is a lysosomal cysteine proteinase associated with degradation of laminin. It is increased in colorectal carcinoma (CA). Laminin is a major component of basement membrane involved in cell-matrix interactions and tumor progression. The aim of this study was to correlate cathepsin B and tumor-associated laminin in colorectal adenomas (ADs) with increasing grades of dysplasia and in invasive CAs. Forty-five ADs (8 tubular, 16 tubulovillous, 21 villous), 13 adenomas with high-grade dysplasia/carcinoma in situ (AHDs), and 17 invasive CAs were immunostained with polyclonal antibodies to cathepsin B and laminin. Statistical analysis was performed using exact linear by linear association test and Spearman rank correlation coefficient. Cathepsin B-positive tumor cells were seen in 30 (67%) ADs, 13 (100%) AHDs, and 17 (100%) CAs. The grade of cathepsin B staining was significantly increased in AHDs and CAs, compared with ADs (P < .0001). Laminin was continuous in all of the ADs and discontinuous or fragmented in the AHDs and CAs (P < .0001). The degree of cathepsin B staining in tumor cells also correlated with breakdown of laminin. Increased cathepsin B expression and decrease in tumor-associated laminin might suggest a mechanism for progression of ADs to CAs.

Adenoma↗
PubMed1998

Effect of selenium deficiency and its supplementation on DTH response, antibody forming cells and antibody titre.

Selenium levels and the activity of Selenoenzyme glutathione peroxidase were measure in whole blood in order to assess the selenium status. Delayed type of hypersensitivity (DTH) reaction was suppressed significantly in selenium deficient rats indicating the decrease in cellular immunity. The B cell function was impaired in selenium deficient rats as evident from decrease in the number of plaque forming cells and antibody titre. Selenium supplementation for 30 days recovered the DTH response and B cell function to a marked extent.

Animals↗
PubMed1998

Role of serum angiotensin converting enzyme in sarcoidosis.

This study was conducted to determine the role of Serum Angiotensin Converting Enzyme (SACE) as a marker in the differential diagnosis of pulmonary diseases and prognosis of sarcoidosis. A retrospective analysis of 113 medical records of patients at The Aga Khan University Hospital, with laboratory investigation for SACE was performed. Among 113 patients, 51 cases were found to have sarcoidosis, 44 of them had SACE levels greater than 52 IU/L (mean ACE 104.44). SACE levels were also found elevated in other clinical conditions like tuberculosis (mean 58.64 IU/L), but the enzyme level were less (p 0.04) than those found in sarcoidosis (mean (92.97 IU/L). SACE activity was found to be considerably lower in other chronic lung diseases such as, fibrosing alveolitis (mean 43.98 IU/L), interstitial lung disease (mean 42.11 IU/L) and chronic obstructive lung disease (mean 40.85 IU/L). Twenty patients of sarcoidosis, who received steroid treatment subsequently showed a decline in the SACE levels. SACE is a useful marker in differential diagnosis as 37.2% cases of sarcoidosis compared to only 9.09% of tuberculosis had SACE levels greater than 100 IU/L. In addition, our data also suggest that serum ACE is useful for the diagnosis as well as monitoring prognosis in sarcoidosis.

Adult↗