Biomedical subjects

N Tariq

Publications and source records attributed to N Tariq.

14 recordsLinked to original sources

PubMed2003

Individual patient variation and inter-rater reliability of lower calyceal infundibular width on routine intravenous pyelography.

OBJECTIVE: To standardise infundibular width (IFW) measurement, to determine patient variability, and to determine inter-rater variability on intravenous pyelography (IVP). PATIENTS AND METHODS: Fifty outpatient IVP films were randomly drawn from two hospitals between 1 July 1998 and 31 August 1999, and examined to measure the lower calyceal IFW on the 5, 10 and 20 min films with compression, and after voiding. Kidneys with previous renal surgery, hydronephrosis or renal anatomical anomalies were excluded; in all, 81 kidneys from 50 patients were examined. The IFW was measured at the narrowest point along the infundibulum. All 50 films were then reviewed by two urologists unaware of their origin, to determine the inter-rater reliability of the infundibular measurements. RESULTS: Analysis of variance (anova) with posthoc analysis showed a significant difference in IFW at each phase of the IVP (repeated measures anova, P < 0.001). The mean (95% confidence interval) IFW was greatest on the compression film, at 4.4 (2.6) mm, and least on the postvoid film, at 1.6 (2.1) mm. Overall inter-rater reliability was 0.9780 (intraclass correlation coefficient), and the Pearson correlation between each rater for the IFW at each phase of the IVP was >/= 0.886. CONCLUSIONS: There is wide variability in lower calyceal IFW among the various IVP films in a given study. Thus any predictive value of the IFW must be standardized for the timing and IVP film type (compression, postvoid, etc.). The inter-rater reliability of IFW is high, suggesting that if used correctly it may be more useful in predicting the outcome after shock wave lithotripsy.

Adolescent↗

PubMed2002

Determination of antimicrobial activity of Cefaclor on common respiratory tract pathogens in Pakistan.

OBJECTIVE: To determine the antimicrobial activity of Cefaclor against common respiratory tract pathogens isolated from patients in Pakistan. SETTING: Department of Microbiology, Liaquat National Postgraduate Medical Centre, Karachi. METHOD: A laboratory analysis was done on 466 isolates of respiratory tract pathogens collected from 13 laboratories from all over Pakistan. Antibiotic sensitivity test was done by Kirby Bauer disc diffusion method and MIC of Cefaclor was determined by 'E' test. RESULT: Of the 163 Streptococcus pneumoniae, 87 Moraxella catarrhalis and 216 Haemophilus influenzae > 95% isolates were susceptible to Cefaclor. The MIC 90 of all these pathogens were < 2 ug. CONCLUSION: Resistance of respiratory tract pathogens to the 2nd generation Cephalosporin, Cefaclor is very low. MIC 90 of Cefaclor against all three common respiratory tract pathogens is < 2 ug, which indicates that Cefaclor would be effective in more than 90% of cases infected with these bacteria.

Cefaclor↗

PubMed2001

Effect of a very-high-fiber vegetable, fruit, and nut diet on serum lipids and colonic function.

We tested the effects of feeding a diet very high in fiber from fruit and vegetables. The levels fed were those, which had originally inspired the dietary fiber hypothesis related to colon cancer and heart disease prevention and also may have been eaten early in human evolution. Ten healthy volunteers each took 3 metabolic diets of 2 weeks duration. The diets were: high-vegetable, fruit, and nut (very-high-fiber, 55 g/1,000 kcal); starch-based containing cereals and legumes (early agricultural diet); or low-fat (contemporary therapeutic diet). All diets were intended to be weight-maintaining (mean intake, 2,577 kcal/d). Compared with the starch-based and low-fat diets, the high-fiber vegetable diet resulted in the largest reduction in low-density lipoprotein (LDL) cholesterol (33% +/- 4%, P <.001) and the greatest fecal bile acid output (1.13 +/- 0.30 g/d, P =.002), fecal bulk (906 +/- 130 g/d, P <.001), and fecal short-chain fatty acid outputs (78 +/- 13 mmol/d, P <.001). Nevertheless, due to the increase in fecal bulk, the actual concentrations of fecal bile acids were lowest on the vegetable diet (1.2 mg/g wet weight, P =.002). Maximum lipid reductions occurred within 1 week. Urinary mevalonic acid excretion increased (P =.036) on the high-vegetable diet reflecting large fecal steroid losses. We conclude that very high-vegetable fiber intakes reduce risk factors for cardiovascular disease and possibly colon cancer. Vegetable and fruit fibers therefore warrant further detailed investigation.

Adult↗

PubMed2001

Electrode performance beyond the manufacturer's recommended lifespan using the Dornier MFL 5000 lithotripter.

BACKGROUND AND PURPOSE: Electrodes used by the Dornier MFL 500 lithotripter have a specified lifespan, after which, the manufacturer recommends replacing the electrode before continuing the treatment. The aim of this study was to investigate whether electrodes continue to function effectively beyond 100% consumption by measuring the pressure output of electrodes up to 300% consumption or until electrode failure. MATERIALS AND METHODS: We assessed new, refurbished, and twice-refurbished electrodes to compare their respective performances. RESULTS: Rather than a decrease, there was a trend toward increased pressure output beyond 100% electrode consumption, with no drop in pressure prior to 300% consumption or electrode failure. All three types of electrodes functioned adequately above 100% consumption. CONCLUSION: These observations suggest that discarding the electrode before the completion of the treatment or electrode failure is not warranted. Using a single electrode rather than multiple electrodes to complete a treatment has the potential to save both time and cost.

Electrodes↗

PubMed2001

Mechanical percussion, inversion and diuresis for residual lower pole fragments after shock wave lithotripsy: a prospective, single blind, randomized controlled trial.

PURPOSE: We compare the effectiveness of mechanical percussion and inversion with observation for eliminating lower caliceal fragments 3 months after shock wave lithotripsy. MATERIALS AND METHODS: At 3 months after shock wave lithotripsy 69 patients with residual lower caliceal fragments 4 mm. or less were randomized to receive either mechanical percussion and inversion or observation for 1 month. The observation group then received crossover mechanical percussion and inversion if fragments persisted. All patients were followed with plain film of the kidneys, ureters and bladder to assess the stone area and stone-free status, and renal tomography or noncontrast spiral computerized tomography to confirm stone-free status. A blinded radiologist reviewed all films. Patients were treated with a mechanical chest percussor applied to the flank while inverted to greater than 60 degrees after receiving 20 mg. furosemide. RESULTS: A total of 35 patients were randomized to receive immediate mechanical percussion and inversion therapy and 34 observation. Of the patients in the observation group 28 subsequently received mechanical percussion and inversion after completing the observation period. The groups were not different in gender, body mass index, side affected, stone location or renal anatomical features. The mechanical percussion and inversion group had a substantially higher stone-free rate than the observation group (40% versus 3%, respectively, p <0.001). The mechanical percussion and inversion group also had a greater improvement in total stone area than controls (-63.3% versus +2.7%, respectively, p <0.001). No significant adverse effects were noted in the mechanical percussion and inversion group. CONCLUSIONS: Mechanical percussion and inversion is a safe and effective treatment option for residual lower caliceal fragments 3 months after shock wave lithotripsy. Nearly 50% of patients become stone-free, and stone burden is decreased by 50% in the remainder.

Adult↗

PubMed2000

Mechanical percussion inversion can result in relocation of lower pole stone fragments after shock wave lithotripsy.

OBJECTIVES: To determine whether mechanical percussion combined with inversion (MPI) therapy and forced diuresis can move stone fragments out of the lower pole of the kidney. METHODS: Twelve patients with lower pole residual stone fragments at least 2 weeks after shock wave lithotripsy were treated using the following protocol. Eleven patients received 20 mg of furosemide before MPI therapy. Patients were treated in the prone Trendelenberg position on a pivoting stretcher and given 10 minutes of percussion over the flank using a mechanical chest physiotherapy percussor. Stone location was documented with plain abdominal radiographs before, immediately after, and 2 weeks following MPI therapy. Voided urine was strained immediately after MPI therapy and throughout the study period. RESULTS: Abdominal radiographs before and after treatment demonstrated movement of fragments out of the lower pole in 11 patients. In 8 patients, the lower pole appeared entirely clear of fragments on the immediate post-treatment film. Four patients passed stone fragments in their first voided urine. Ten patients passed stone fragments during the 2-week follow-up period. CONCLUSIONS: MPI therapy combined with diuresis can effectively mobilize stone fragments out of the lower pole calyces and appears to aid in the passage of fragments.

Diuretics↗

PubMed2000

Shockwave frequency affects fragmentation in a kidney stone model.

PURPOSE: To study the effect of altering shockwave frequency on the efficiency of stone fragmentation using the MFL 5000 spark-gap lithotripter. MATERIALS AND METHODS: Standardized solid plaster stones, 12.0 +/- 0.5 mm in diameter, were fragmented at an energy setting of 20 kV. The shockwave frequencies tested were 60, 80, and 117 per minute. Stones were fragmented throughout the entire lifespan of the electrode, from 0 to >100% consumption, at each frequency tested. Electrode pressure output was studied for each frequency. RESULTS: A greater number of shocks was required to fragment the plaster balls at higher frequencies (regression coefficient 1.93; p < 0.003). An inverse relation was found between the number of shocks necessary to break the stones and electrode consumption (regression coefficient -2.16; p < 0.001). The analysis of delivered pressure from the electrode failed to demonstrate a linear relation with frequency (regression coefficient -0.40; p < 0.728) or consumption (regression coefficient -1.11; p < 0.158). CONCLUSIONS: The number of shocks required to fragment a stone is influenced in part by the frequency at which the shockwaves are delivered. Increasing the shockwave frequency from 60 to 117 per minute in this study caused a significant rise in the number of shocks required to break the stone. The pressure output of the electrode was similar at the frequencies tested, thus making the difference in stone fragmentation secondary to the mechanism of stone disintegration and not the function of the electrode.

Dose-Response Relationship, Radiation↗

PubMed2000

Effect of soluble and insoluble fiber diets on serum prostate specific antigen in men.

PURPOSE: We assess whether high fiber diets influence serum prostate specific antigen (PSA) related to effects on serum sex hormone levels and fecal steroid excretion. MATERIALS AND METHODS: A randomized crossover controlled trial was performed on 14 healthy men with hyperlipidemia on 2 metabolic diets 4 months in duration with each containing foods high in soluble or insoluble fiber and approximately 25 to 30 gm. dietary fiber per 1,000 kilocalories. Serum PSA, free testosterone and estradiol, and fecal bile acid and neutral sterol excretion were evaluated. RESULTS: Mean serum PSA was lower with the soluble than the insoluble fiber diet (0.07+/-0.03 ng./ml., p = 0.035). No treatment difference was seen in free testosterone or estradiol, although the latter decreased significantly with the insoluble fiber diet (9+/-3 pmol./l., p = 0.004). After 16 weeks total fecal bile acid output was greater with the soluble (341+/-56 mg. daily) compared to the insoluble (203+/-35, p = 0.001) fiber diet but no differences were seen in fecal neutral sterol elimination. The treatment difference in fecal lithocholic acid output related to the difference in serum PSA (r = 0.57, p = 0.035). CONCLUSIONS: A small but statistically significantly lower serum PSA was seen in healthy men consuming soluble fiber, which was not related to changes in serum sex hormones but was related to the increased lithocholic acid output as a possible marker of increased fecal steroid elimination. The effect of soluble fiber on prostatic disease may warrant further investigation.

Adult↗

PubMed2000

Low success rate of repeat shock wave lithotripsy for ureteral stones after failed initial treatment.

PURPOSE: We determined the number of shock wave lithotripsy treatments that should be given for a single ureteral stone before alternate modalities are used. MATERIALS AND METHODS: We compared the stone-free rate of initial shock wave lithotripsy for ureteral calculi with that of subsequent treatments. We evaluated 1,593 ureteral stones treated with the Dornier MFL 5000 lithotriptor* from January 1, 1994 to September 1, 1999 using various parameters associated with treatment outcome. RESULTS: The stone-free rate after initial treatment was 68% (1,086 of 1,593 stones), which decreased to 46% (126 of 273) after re-treatment 1. We observed a further decrease in the stone-free rate after re-treatment 2 to 31% (19 of 61 stones, p = 0.001). The cumulative stone-free rate increased to 76% (1,212 of 1,593 stones) after 2 treatments and to 77% (1,231 of 1593) after 3. The stone-free rate for stones 10 mm. or less was significantly better than that of stones 11 to 20 mm. initially (64% versus 43%) and after re-treatment (49% versus 37%). A ureteral stent decreased the stone-free rate of initial treatment and re-treatment 1 by 12% and 14%, respectively (p = 0.001). After initial treatment the stone-free rate of the upper and mid ureter was significantly higher than that of the lower ureter. Patient weight had no significant impact on success in either group. CONCLUSIONS: The stone-free rate of re-treating ureteral calculi with shock wave lithotripsy decreases significantly after the initial treatment. These findings imply that ureteroscopic management of ureteral stones may be better than shock wave lithotripsy after initial shock wave lithotripsy fails.

Adolescent↗

PubMed1999

cAMP-induced phosphorylation and inhibition of Na(+)/H(+) exchanger 3 (NHE3) are dependent on the presence but not the phosphorylation of NHE regulatory factor.

The members of the regulatory factor (RF) gene family, Na(+)/H(+) exchanger (NHE)-RF and NHE3 kinase A regulatory factor (E3KARP) are necessary for cAMP to inhibit the epithelial brush border NHE isoform 3 (NHE3). The mechanism of their action was studied using PS120 fibroblasts stably transfected with rabbit NHE3 and wild type rabbit NHE-RF or wild type human E3KARP. 8-Bromo-cAMP (8-Br-cAMP) had no effect on Na(+)/H(+) exchange activity in cells expressing NHE3 alone. In contrast, in cells co-expressing NHE-RF, 8-Br-cAMP inhibited NHE3 by 39%. In vivo phosphorylation of NHE3 demonstrated that cAMP increased phosphorylation in two chymotrypsin-generated phosphopeptides of NHE3 in cells containing NHE-RF or E3KARP but not in cells lacking these proteins. The requirement for phosphorylation of NHE-RF in this cAMP-induced inhibition of NHE3 was examined by studying a mutant NHE-RF in which serines 287, 289, and 290 were mutated to alanines. Wild type NHE-RF was a phosphorylated protein under basal conditions, but treatment with 8-Br-cAMP did not alter its phosphorylation. Mutant NHE-RF was not phosphorylated either under basal conditions or after 8-Br-cAMP. 8-Br-cAMP inhibited NHE3 similarly in PS120/NHE3 cells containing wild type or mutant NHE-RF. NHE-RF and NHE3 co-precipitated and did so similarly with and without cAMP. Mutant NHE-RF also similarly immunoprecipitated NHE3 in the presence and absence of 8-Br-cAMP. This study shows that members of the regulatory factor gene family, NHE-RF and E3KARP, are necessary for cAMP inhibition of NHE3 by allowing NHE3 to be phosphorylated. This inhibition is not dependent on the phosphorylation of NHE-RF.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1999

Colonic bacterial activity and serum lipid risk factors for cardiovascular disease.

Antibiotics are being proposed for the treatment of cardiovascular disease. In the past, antibiotics were advocated for the control of hypercholesterolemia. We have therefore investigated the relation between colonic bacterial activity and serum lipids. In a four-phase randomized crossover study, we fed a different starch supplement during each 2-week phase to 24 healthy subjects. In two phases, supplements containing resistant starches were fed that reach the colon and are largely fermented by colonic bacteria. Fecal starch recovery therefore reflects the metabolic activity of colonic microflora. The control treatments were conventional starches. Blood lipid levels were obtained at the start and 4-day fecal collections at the end of each phase. Resistant starch supplements increased fecal starch excretion by 3.8 +/- 1.2 g/d more than conventional starches (P = .006). Mean starch excretion was related positively to pretreatment serum high-density lipoprotein (HDL) cholesterol (r = -.57, P = .003) and negatively to low-density lipoprotein (LDL) cholesterol (r = -.57, P = .004), apolipoprotein B:AI (r = -.56, P = .005), and fecal output of fusobacteria (r = -.73, P = .003) and bacteroides (r = -.72, P = .003). The ratio of fusobacteria to total anaerobes was also related to pretreatment LDL cholesterol (r = .56, P = .037). Differences in starch excretion between healthy subjects, as a measure of bacterial activity, accounted for 32% of the variation in pretreatment LDL cholesterol. The activity of colonic microflora therefore appears to influence serum lipid levels. Alterations of bacterial number and activity may provide an additional strategy to control serum lipid risk factors for cardiovascular disease.

Adult↗

PubMed1997

Effect of a diet high in vegetables, fruit, and nuts on serum lipids.

We assessed the effect of a diet high in leafy and green vegetables, fruit, and nuts on serum lipid risk factors for cardiovascular disease. Ten healthy volunteers (seven men and three women aged 33 +/- 4 years [mean +/- SEM]; body mass index, 23 +/- 1 kg/m2) consumed their habitual diet (control diet, 29% +/- 2% fat calories) and a diet consisting largely of leafy and other low-calorie vegetables, fruit, and nuts (vegetable diet, 25% +/- 3% fat calories) for two 2-week periods in a randomized crossover design. After 2 weeks on the vegetable diet, lipid risk factors for cardiovascular disease were significantly reduced by comparison with the control diet (low-density lipoprotein [LDL] cholesterol, 33% +/- 4%, P < .001; ratio of total to high-density lipoprotein [HDL] cholesterol, 21% +/- 4%, P < .001; apolipoprotein [apo] B:A-I, 23% +/- 2%, P < .001; and lipoprotein (a) [Lp(a)], 24% +/- 9%, P = .031). The reduction in apo B was related to increased intakes of soluble fiber (r = .84, P = .003) and vegetable protein (r = -.65, P = .041). On the vegetable compared with the control diet, the reduction in total serum cholesterol was 34% to 49% greater than would be predicted by differences in dietary fat and cholesterol. A diet consisting largely of low-calorie vegetables and fruit and nuts markedly reduced lipid risk factors for cardiovascular disease. Several aspects of such diets, which may have been consumed early in human evolution, have implications for cardiovascular disease prevention.

Adult↗

PubMed1997

Metabolic effects of non-absorbable carbohydrates.

Food components which are incompletely absorbed in the small intestine or not absorbed at all but are delivered to the colon have been part of the diet throughout the course of human evolution. Our great ape cousins may derive 30% or more of their dietary calories from colonic uptake of short-chain fatty acids (SCFAs) generated in the colon. The metabolic effects of dietary carbohydrate entering the colon are many and include laxation, the growth of the fecal biomass, nitrogen entrapment and SCFA generation. These SCFAs in turn may nourish mucosal cells, spare glutamine utilization, enhance hepatic gluconeogenesis and lipogenesis and possibly influence renal handling of uric acid. The health implications are significant in terms of modifying risk factors for disease and disease prevention and justify interest in the metabolic effects of non-absorbable sugars such as lactulose.

Animals↗

PubMed1997

The western lowland gorilla diet has implications for the health of humans and other hominoids.

We studied the western lowland gorilla diet as a possible model for human nutrient requirements with implications for colonic function. Gorillas in the Central African Republic were identified as consuming over 200 species and varieties of plants and 100 species and varieties of fruit. Thirty-one of the most commonly consumed foods were collected and dried locally before shipping for macronutrient and fiber analysis. The mean macronutrient concentrations were (mean +/- SD, g/100 g dry basis) fat 0.5 +/- 0.4, protein 11.8 +/- 8.2, available carbohydrate 7.7 +/- 6.3 and dietary fiber 74.0 +/- 12.9. Assuming that the macronutrient profile of these foods was reflective of the whole gorilla diet and that dietary fiber contributed 6.28 kJ/g (1.5 kcal/g), then the gorilla diet would provide 810 kJ (194 kcal) metabolizable energy per 100 g dry weight. The macronutrient profile of this diet would be as follows: 2.5% energy as fat, 24.3% protein, 15.8% available carbohydrate, with potentially 57.3% of metabolizable energy from short-chain fatty acids (SCFA) derived from colonic fermentation of fiber. Gorillas would therefore obtain considerable energy through fiber fermentation. We suggest that humans also evolved consuming similar high foliage, high fiber diets, which were low in fat and dietary cholesterol. The macronutrient and fiber profile of the gorilla diet is one in which the colon is likely to play a major role in overall nutrition. Both the nutrient and fiber components of such a diet and the functional capacity of the hominoid colon may have important dietary implications for contemporary human health.

Animal Nutritional Physiological Phenomena↗