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Biomedical subjects

A Tang

Publications and source records attributed to A Tang.

123 records · Page 7Linked to original sources
PubMed1986

Randomized trial of allopurinol in the prevention of calcium oxalate calculi.

In a double-blind study, we examined the efficacy of allopurinol in the prevention of recurrent calcium oxalate calculi of the kidney. Sixty patients with hyperuricosuria and normocalciuria who had a history of calculi were randomly assigned to receive either allopurinol (100 mg three times daily) or a placebo. After the study, the placebo group had 63.4 percent fewer calculi (P less than 0.001), whereas the allopurinol group had 81.2 percent fewer calculi (P less than 0.001). During the study period, the mean rate of calculous events was 0.26 per patient per year in the placebo group and 0.12 in the allopurinol group. When the treatment groups were compared by actuarial analysis, the allopurinol group was found to have a significantly longer time before recurrence of calculi (P less than 0.02). We conclude that allopurinol is effective in the prevention of calcium oxalate stones in patients with hyperuricosuria. The large reduction in the frequency of calculi in the placebo group underscores the positive treatment bias that regularly occurs in trials of prophylaxis against renal calculi when historical controls are used.

Allopurinol↗
PubMed1986

Sex-specific criteria for interpretation of thallium-201 myocardial uptake and washout studies.

A study was undertaken to determine the effect of gender on criteria for the quantitative analysis of exercise-redistribution 201Tl myocardial scintigraphy. The studies of 26 normal females and 23 normal males were subjected to bilinear interpolative background subtraction and horizontal profile analysis. Significant sexual differences were found in both regional uptake ratios and washout rates. These differences primarily reflected a proportionately decreased anterior and upper septal uptake in females, and faster washout in females. Faster myocardial 201Tl washout rates in females could not be clearly ascribed to either a physiological or artifactual explanation. It is concluded that since important differences exist between males and females in the detected pattern of 201Tl myocardial uptake and washout, sex-specific criteria may enhance the predictive accuracy of exercise-redistribution 201Tl myocardial scintigraphy.

Adult↗
PubMed1985

Reserpine-induced hypothermia and its reversal by dopamine agonists.

Prior treatments with reserpine altered the thermic response of mice to subsequently administered apomorphine and amphetamine. Thus, normal mice exhibited hypo- and hyper-thermic responses to apomorphine and (+)-amphetamine, respectively but did not respond to (-)-amphetamine. These responses were each readily attenuated by haloperidol. Reserpinized mice, on the other hand, exhibited hyperthermic responses to all three agonists and these responses were not attenuated by haloperidol. In addition to its hypothermic action, reserpine also produced hypoactivity which was reversed by (+)-amphetamine. This reversal of hypoactivity was attenuated by haloperidol. These data suggest that reversal of reserpine-induced hypothermia by dopamine agonists results through activation of mechanisms which are separate from those normally associated with agonist-induced thermic responses. Reversal of hypoactivity, on the other hand, appears to be due to reactivation of those systems which normally regulate locomotor activity.

Amphetamine↗
PubMed1983

Marked lymphocytosis suggesting chronic lymphocytic leukemia in three patients with hyposplenism.

Three patients with hyposplenism of diverse cause are described, in whom marked persistent lymphocytosis suggested the diagnosis of an early phase of chronic lymphocytic leukemia. Absolute lymphocyte counts ranged from 4,900/mm3 to 10,500/mm3. Patient follow-up ranged from 120 months to 294 months. The clinical course and additional test results, including results of lymphocyte surface marker analysis in all three patients and bone marrow biopsy in two, excluded the diagnosis of chronic lymphocytic leukemia. The finding of marked lymphocytosis in the hyposplenic state is emphasized, extending the degree of absolute lymphocytosis previously reported and thereby expanding the differential diagnosis of sustained lymphocytosis. In addition, the normal findings on both bone marrow and surface marker studies, along with the prolonged clinical course, support the contention that this is a benign entity.

Adult↗
PubMed1983

Rehabilitation of burns of the upper limb.

The authors wish to document the experience of the Burns Unit, Singapore General Hospital in the management of burns of the upper limb. Fifty-six patients with post-burn deformity of the upper limb seen during a five year period (July 1978-July 1983) were reviewed. The cases were analysed and there were no significant differences in age, sex and race distribution. There were 8 axillary contractures, 9 elbow contractures, 10 wrist deformities and 56 hand deformities. Anterior axillary skin fold contracture was the commonest deformity occurring at the shoulder, whilst cubital contractures were mainly found on the lateral aspect of the elbow. The elbow was the commonest site for periarticular heterotopic calcification. Wrist deformities included hypertrophic scars and contractures and they were frequently found on the dorsum of the wrist. A classification of post-burn hand deformity has been described and this was based on the site of the original injury. Burns involving the dorsum of the hand/fingers were subclassified into two groups depending on whether the extensor tendon was involved. The prognosis was good when there was no tendon injury, but when the extensor tendons were involved, poorer hand function resulted and this was reflected by the number of secondary operative procedures required. Flexion contractures were the commonest deformity found on volar burns. When both surfaces were burned the prognosis depended upon the burns depth. Digital burns treated surgically had fewer residual contractures. The role of occupational therapy, scar control, splinting and secondary surgery in relation to the rehabilitation of the burned upper limb is discussed in some detail.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1981

Abnormal force--EMG relations in paretic limbs of hemiparetic human subjects.

The relations between surface EMG and isometric force generated by elbow flexor muscles were compared in normal and paretic limbs of 17 hemiparetic human subjects. Similar analyses were performed on both arms of 11 normal subjects. In almost half of the hemiparetic subjects examined (8/17), the slope of the relation between elbow flexion force and surface EMG, measured over the biceps-brachialis and brachioradialis muscle groups was increased in the paretic limb. A mechanism based on anomalous reductions in mean motor unit discharge rate in paretic muscles is advanced as the most likely cause of the findings.

Adult↗
PubMedDate not supplied

Dietary intake of community-based HIV-1 seropositive and seronegative injecting drug users.

Dietary intake was assessed in a subsample of a cohort of inner-city injecting drug users (IDUs). In this population of predominantly African-American IDUs, including both HIV -1-infected and noninfected men and women, a food frequency questionnaire (FFQ) and a 24-h recall were administered. One hundred seven volunteers participated. Although total caloric intake was consistently higher with the food frequency method, percent of total calories from fat, protein, and carbohydrates were similar between the FFQ and 24-h recall. Spearman's correlations for agreement between the 24-h recall and the FFQ ranged from 0.22 for vitamin E to 0.52 for carbohydrates. HIV-1 seropositives reported higher protein (p = 0.05) and fat (p = 0.02) consumption than seronegatives according to the 24-h recall. The difference in total fat consumption was due to higher intakes of saturated and monounsaturated fats (p = 0.01). Median intakes of vitamins B2 and B12, pantothenic acid (p < or = 0.05), phosphorous (p < or = 0.01), and selenium (p < or = 0.005) were also greater in HIV-1 seropositives. Reported intake of vitamins A and E, calcium, and zinc were below the recommended daily allowances for both HIV-1 seropositives and seronegatives. Although intakes of most nutrients appeared adequate for the group as a whole, extreme ranges were observed and may be the result of imbalanced food selections and day to day variation. Food group analysis indicated low intakes of fruits, vegetables, milk, and milk products. More research is needed to fully understand the implication of dietary habits and nutritional status in the free-living HIV-1-infected and noninfected IDUs.

Adult↗
PubMedDate not supplied

Self-assembled peptides exposing epitopes recognizable by human lymphoma cells.

A bifunctional N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer containing nitrilotriacetic acid (NTA) and benzophenone (BP) groups was synthesized by free-radical copolymerization of HPMA, 2-methacrylamidobutyl nitrilotriacetic acid (MABNTA), and 4-methacrylamido benzophenone (MABP) using 2, 2'-azobisisobutyronitrile (AIBN) as initiator. A His-tagged coiled coil stem loop peptide containing a tridecapeptide (TDP) epitope (GFLGEDPGFFNVE) in the loop region (CCSL-TDP) was designed and synthesized genetically by expressing an artificial gene in Escherichia coli BL21 (DE3). The peptide was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), size-exclusion chromatography (SEC), and circular dichroism (CD) spectroscopy. Surfaces containing self-assembled CCSL-TDP peptide were prepared by first covalently grafting poly(HPMA-co-MABNTA-co-MABP) onto polystyrene (PS) surface by UV irradiation, then charging the surface with nickel through NTA groups, and finally attaching the CCSL-TDP peptide through Ni-histidine chelation. The modified PS surfaces with and without self-assembled CCSL-TDP peptide were characterized by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). Cell attachment studies with human Burkitt's lymphoma Raji B cells showed that the cells selectively bound to the self-assembled CCSL-TDP peptide surfaces, but not to the surfaces of PS, PS with grafted copolymer, and PS with grafted copolymer and self-assembled coiled coil peptide with similar structure but without the epitope. This indicates that the cell attachment was mediated by the CCSL-TDP peptide, most probably by the TDP epitope region. The CCSL peptide self-assembly presented here may represent a feasible model of exposing epitopes for biorecognition studies.

Acrylamides↗
PubMedDate not supplied

Anomalous origin of the left main coronary artery from the right sinus of Valsalva: disabling angina and syncope with noninterarterial courses case report of two patients.

Anomalous origin of the left main coronary artery from the right sinus of Valsalva or the right coronary artery is a rare coronary anomaly. This anomaly has been associated with sudden cardiac death in younger patients, depending on its course relative to the pulmonary artery. The authors report this rare anomaly in two patients. It presented as unstable angina in the first patient with a septal course. In the second patient, it presented as syncope with an anterior free wall course and absent left circumflex artery. A septal course causing unstable angina has not been reported previously.

Aged↗
PubMedDate not supplied

The effect of sinus node depression on heart rate variability in humans using zatebradine, a selective bradycardic agent.

Zatebradine is a bradycardic agent with a selective effect on the pacemaker current in the sinus node. The effect of such drugs on heart rate variability is not known. Thirty-six patients without structural heart disease were randomly assigned to receive 10 mg of zatebradine i.v. (n = 24) or isotonic saline (n = 12). Heart rate variability (HRV) was recorded as power in the very low frequency (VLF, 0.003-0.040 Hz), low frequency (LF, 0.040-0.150 Hz), and high frequency (HF, 0.150-0.400 Hz) spectral bands as well as total power (TP, 0.003-0.400 Hz) during 5-min ECG acquisitions at baseline, 30, and 60 min following the start of the infusion. No change in heart rate variability was detected in the control group. Zatebradine significantly reduced heart rate variability at 60 min in all frequency bands: VLF (-12+/-4%, p<0.001), LF (-19+/-4%, p<0.001), and HF (-26+/-5%, p<0.001). The reduction in HRV following zatebradine is due to depression of sinus node response to all external stimuli and underscores the need for documentation of normal sinus node function in HRV research.

Adult↗