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Biomedical subjects

A Ali

Publications and source records attributed to A Ali.

At least 217 records · Page 12Linked to original sources
PubMed1997

Larval case-making behavior of a pestiferous chironomid, Glyptotendipes paripes (Diptera: Chironomidae), with sand grains of different sizes.

Field-collected 4th-instar Glyptotendipes paripes larvae from a natural lake in central Florida preferred small-sized (< 0.84-1.99-mm-diam) grains of sand to burrow in and make cases in the laboratory. The larvae buried or formed cases within 3 h of introduction into 120-ml paper cups containing 80 ml tap water and 20 g of the small-diameter sand. When placed in sand with grains of different size ranges, 98-100% of the larvae constructed cases in sand < 0.84 mm in diameter, whereas 86% of these larvae built cases in 0.85-1.99-mm-diam sand. The larvae were unable to construct any recognizable cases in coarser sand (2-3-mm diam). The lengths of cases built with smaller sand grains were significantly longer than those constructed in the larger grains used in the experiment. For laboratory colonization and insecticidal bioassay purposes using G. paripes larvae, sand grains < 0.84 mm in diameter should be utilized for better acclimation of the larvae.

Animals↗
PubMed1996

Molecular cloning of a cDNA encoding a Xenopus laevis 70-kDa heat shock cognate protein, hsc70.II.

We have isolated and sequenced a full-length cDNA clone encoding a Xenopus laevis 70 kDa heat shock cognate protein, hsc70.II. The protein coding region exhibited high identity with Xenopus hsc70.I (94%), suggesting that the two genes are the result of a genomic tetraploidization event which occurred in Xenopus over 30 million years ago. Also, hsc70.II displayed a high level of identity with mammalian hsc70. However, the identity of Xenopus hsc70.II cDNA with Xenopus hsp70 was only 82%. At the carboxyl end of the hsc70.II protein, the identity with hsc70.I was 85%, while the identity for hsp70 was only 58%. These data support the theory that the inducible and constitutive members of the hsp70 family diverged well before the emergence of amphibians. Also, hsc70.II contains a number of conserved elements including an ATP-binding domain, a nuclear localization signal and the carboxyl terminal motif, EEVD, which may have a role in chaperone function.

Adenosine Triphosphate↗
PubMed1996

[Trimethoprim-sulfamethoxazole-induced cholestatic hepatitis. Clinico-immunological demonstration of its allergic origin].

HISTORY AND CLINICAL FINDINGS: A 22-year-old woman was given trimethoprim plus sulphamethoxazole for a urinary infection (160 and 800 mg, respectively, daily), drugs she had not previously taken. After 2 weeks she noticed a rash of small spots on her trunk. In addition she had nausea and vomiting. The rash faded within 2 days of stopping the drug, but progressive jaundice developed. INVESTIGATIONS: SGPT and SGOT concentrations rose to maximally 328 and 83 U/l, total bilirubin to maximally 5.9 mg/dl. There was no evidence for viral hepatitis (B or C, cytomegalovirus, Epstein-Barr), autoimmune hepatitis or primary biliary hepatitis. Liver biopsy showed central acinar cholestasis, which suggested drug-induced liver damage. COURSE: The patient's symptoms regressed over several weeks without any specific treatment and 8 weeks after onset of the rash the laboratory tests also became normal. The allergic cause of the cholestatic hepatitis was confirmed by a lymphocyte transformation test. CONCLUSION: Clinical suspicion of drug allergy as cause of a cholestatic hepatitis can be confirmed reliably and without any risk to the patient with the lymphocyte transformation test.

Adult↗
PubMed1996

Validation of a knowledge-based boundary detection algorithm: a multicenter study.

A completely operator-independent boundary detection algorithm for multigated blood pool (MGBP) studies has been evaluated at four medical centers. The knowledge-based boundary detector (KBBD) algorithm is nondeterministic, utilizing a priori domain knowledge in the form of rule sets for the localization of cardiac chambers and image features, providing a case-by-case method for the identification and boundary definition of the left ventricle (LV). The nondeterministic algorithm employs multiple processing pathways, where KBBD rules have been designed for conventional (CONV) imaging geometries (nominal 45 degrees LAO, nonzoom) as well as for highly zoomed and/or caudally tilted (ZOOM) studies. The resultant ejection fractions (LVEF) from the KBBD program have been compared with the standard LVEF calculations in 253 total cases in four institutions, 157 utilizing CONV geometry and 96 utilizing ZOOM geometries. The criteria for success was a KBBD boundary adequately defined over the LV as judged by an experienced observer, and the correlation of KBBD LVEFs to the standard calculation of LVEFs for the institution. The overall success rate for all institutions combined was 99.2%, with an overall correlation coefficient of r=0.95 (P<0.001). The individual success rates and EF correlations (r), for CONV and ZOOM geometers were: 98%, r=0.93 (CONV) and 100%, r=0.95 (ZOOM). The KBBD algorithm can be adapted to varying clinical situations, employing automatic processing using artificial intelligence, with performance close to that of a human operator.

Algorithms↗
PubMed1996

Isolation and characterization of a cDNA encoding a Xenopus 70-kDa heat shock cognate protein, Hsc70.I.

We isolated a full-length cDNA clone encoding a Xenopus laevis 70-kDa heat shock cognate protein, hsc70.I. The protein coding region exhibits a high degree of identity with a number of mammalian hsc70 proteins, such as rat hsc71 (92%), whereas the identity to Xenopus hsp70 is only 80%. These data suggest that the inducible and constitutive forms of hsp70 diverged long before the emergence of amphibians. The Xenopus hsc70.I contains a number of conserved elements, including the ATP-binding domain, a nuclear localization signal and the carboxy-terminal EEVD motif, which has been implicated in several activities associated with chaperonin function. Northern blot analyses revealed that maternal hsc70.I mRNA is present in cleavage and early blastula stages of Xenopus development. After the onset of zygotic transcription at the midblastula stage, the levels of hsc70.I message increase through to the tadpole stages. Furthermore, in contrast to hsp70 mRNA, the relative levels of hsc70.I mRNA are not enhanced after heat shock in embryos and in the kidney epithelial cell line, A6. The levels of hsc70.I mRNA are high in adult spleen and testis, with moderate levels in eye, heart, liver and brain and comparatively low levels in hindlimb muscle.

Amino Acid Sequence↗
PubMed1996

Decline in the rate of hospital mortality from acute myocardial infarction: impact of changing management strategies.

This study examined the profile and management of acute myocardial infarction in patients hospitalized in the coronary care unit of Henry Ford Hospital to determine risk factors or treatments that best explained a decline in in-hospital mortality rates. During the 1980s and early 1990s, many therapeutic advances occurred in management of acute infarction. Overall and in-hospital mortality were observed also to decline, but little is known about the relation of newer treatments to clinical outcome. The study population consisted of 1798 patients with a confirmed diagnosis of myocardial infarction. Of these, 982 consecutive patients were hospitalized in the coronary care unit of Henry Ford Hospital from January 1981 through December 1984 and compared with the 816 consecutive patients hospitalized from January 1990 through October 1992. Data on baseline demographics, initial clinical features, in-hospital management, and in-hospital outcome were compared for the two groups. Logistic regression was used to define independent predictors of the improved outcome of the two groups. Demographic features of the earlier group were similar to those of the later cohort, with the exception of a greater incidence of diabetes and hypertension and a lesser incidence of angina and prior heart failure. The occurrence of non-Q wave infarction increased from 27% in the earlier to 39% in the later group, whereas the magnitude of peak creatine kinase elevation in serum was higher in the later group. Medical management differed significantly, with increased use of aspirin, thrombolytics, heparin, warfarin, nitrates, and beta-blockers and decreased use of antiarrhythmic agents, digoxin, and vasopressors in the later group. Coronary revascularization was performed during hospitalization in 6.4% of the earlier group of patients and 31.6% of the later group. In-hospital mortality was 14.7% in the earlier group and 7.4% in the later group. Multivariate logistic regression analysis showed that the difference in mortality between the two groups was best accounted for by increased use of beta-blockers, angioplasty, and thrombolytics, decreased incidence of cardiogenic shock and asystole, and decreased use of lidocaine. In conclusion, the presentation and in-hospital management of patients with acute myocardial infarction has changed from the early 1980s to the early 1990s. The improved hospital mortality rate may be associated with both the expanded use of effective therapies and a more favorable in-hospital course, although these are not mutually exclusive.

Cardiovascular Agents↗
PubMed1996

Parkinson's disease, cognition and aging. Clinical, neuropsychological, electrophysiological and cranial computerized tomographic assessment.

Forty-three patients with Parkinson's disease (PD) and thirty-seven normal volunteers were subjected to clinical, neuropsychological, neurophysiological (P300 component of the event-related potentials ERP) and radiological (cranial computerized tomographic scanning CCT) evaluation. Intentional memory was more impaired in PD than in normal controls, more so in the demented group of patients, and was related to enlargement of third ventricular size in CCT. While intentional memory was age related in PD patients, perception was age-related in normal controls. Neither global nor specific cognitive functions were related to duration, severity of parkinsonian motor disability, or depression. However, depression in PD was significantly related to parkinsonian motor disability. P300 latency was more prolonged in PD patients than normal controls. P300 parameters of PD patients were not influenced by age, cognitive functions, duration or severity of motor disability, or depression. The reaction time was the only P300 parameter that was age-related in normal controls. Subcortical atrophy as indicated by CCT was more marked in PD and correlated with age in both patients and controls. Subcortical atrophy was significantly related to cognitive functions in PD but not in normal controls. It was concluded that cognitive impairment in PD could be attributed to complex cognitive changes rather than age. It is a disease process, though not directly related to parkinsonian motor disability or depression. PD differed from normal aging as regards the effect of age on the specific cognitive functions, where in PD patients, age was related to intentional memory, yet in normal controls, it was related to perception. Intentional memory deterioration was found to be specific of PD, being related to subcortical atrophy as well as being more pronounced in the demented group of patients.

Aged↗
PubMed1996

Postdialysis fatigue.

To clarify the demographic and clinicolaboratory features of postdialysis fatigue (PDF), we enrolled 85 patients on maintenance hemodialysis in a cross-sectional study using validated questionnaires and chart review. Forty-three patients complained of fatigue after dialysis. On formal testing using the Kidney Disease Questionnaire, the PDF group had statistically greater severity of fatigue and somatic complaints than the group of patients without subjective fatigue (P = 0.03 and 0.04, respectively). On a scale measuring intensity of fatigue (1 = least to 5 = worst), the PDF group average was 3.4 +/- 1.2. PDF subjects reported that 80% +/- 25% of dialysis treatments were followed by fatigue symptoms. In 28 (65%) of patients, the symptoms started with the first dialysis treatment. They reported needing an average of 4.8 hours of rest or sleep to overcome the fatigue symptoms (range, 0 to 24 hours). There were no significant differences between patients with and without PDF in the following parameters: age; sex; type of renal disease; presence of diabetes mellitus, heart disease (congestive, ischemic), or chronic obstructive lung disease; blood pressure response to dialysis; type or adequacy of dialysis regimen; hematocrit; electrolytes; blood urea nitrogen; creatinine; cholesterol; albumin; parathyroid hormone; ejection fraction; and use of antihistamines, benzodiazepines, and narcotics. In the fatigue group, there was significantly greater use of antihypertensive medications known to have fatigue as a side effect (P = 0.007). Depression was more common in the fatigue group by Beck Depression score (11.6 +/- 8.0 v 7.8 +/- 6.3; P = 0.02). We conclude that (1) postdialysis fatigue is a common, often incapacitating symptom in patients on chronic extracorporeal dialysis; (2) no routinely measured parameter of clinical or dialytic function appears to predict postdialysis fatigue; and (3) depression is highly associated with postdialysis fatigue, but the cause-effect relationship is unclear.

Antihypertensive Agents↗
PubMed1996

SLE autoantibodies recognize spermine induced Z-conformation of native calf thymus DNA.

The binding specificity of naturally occurring anti-DNA antibodies with spermine modified DNA was analyzed by direct binding and competition ELISA. The binding was visualised by band shift assay. The SLE anti-DNA antibodies appreciably recognized the spermine induced Z-conformation of native DNA. The degree of binding of these antibodies to the Z-conformer was almost similar to their binding with native DNA. The spermine-DNA complex was found to be thermodynamically more stable than native DNA.

Animals↗
PubMed1996

Normal thymic uptake of FDG on PET imaging.

Assessment and characterization of the thymus by various imaging methods have been extensively described. The authors report increased uptake of 2-(18)Fluoro-2-deoxy-D-glucose (FDG) in the normal thymus gland of patients between the ages of 2 and 13 years. Most of these patients had PET scans for various oncologic conditions and had no clinical problems referable to the thymus gland. This uptake assumes an important role when evaluating mediastinal uptake in whole-body PET scans in pediatric oncology patients to avoid false-positive interpretation.

Adolescent↗
PubMed1996

Sex-role attitudes and clinical appraisal in psychiatry residents.

OBJECTIVE: To measure sex-role beliefs of psychiatry residents and to examine bias in clinical appraisal. METHOD: Residents (45 female, 51 male) evaluated 1 of 4 possible clinical case histories-a female or male patient with histrionic personality disorder (HPD) or antisocial personality disorder (APD)-and completed the Sex-Role Egalitarianism Scale (SRES). RESULTS: As predicted, female residents were more egalitarian than male residents (P < 0.03) according to the SRES. As expected, significantly more male than female patients received the diagnosis of APD (P < 0.00002). Although it was predicted that female patients would more often be given the HPD diagnosis than males, no significant gender differences were found. Sex of resident was not found to influence clinical behaviour significantly. CONCLUSIONS: These results highlight differential sex-role attitudes, as measured by the SRES, between female and male residents and suggest that residents' sex-role biases affect the diagnosis of APD. These results have implications for psychiatric assessment and treatment. Further understanding of these issues is critical to the development of educational tools to address sex biases in psychiatry.

Adult↗
PubMed1996

Effects of ATP-magnesium chloride on the cardiopulmonary manifestations of group B streptococcal sepsis in the piglet.

Low dose ATP-MgCl2 is reported to cause selective pulmonary vasodilation during hypoxic and thromboxane mimetic-induced constriction. In addition, it has been shown to increase cardiac output and improve cellular function during circulatory shock. Based on these properties we hypothesized that ATP-MgCl2 might ameliorate the cardiopulmonary manifestations of sepsis secondary to group B streptococci (GBS). We studied 14 anesthetized, mechanically ventilated piglets who received a continuous infusion of GBS (7.5 x 10(7) colony-forming units/kg/min) and were randomly assigned to a treatment group that received a continuous infusion of ATP-MgCl2 at 0.6 mumol/kg/min or a control group that received normal saline as placebo. Comparison of the hemodynamic measurements, pulmonary mechanics, and arterial blood gases over the first 120 min of ATP-MgCl2 infusions with those of the control group revealed the following: GBS infusion caused significant increases in mean pulmonary artery pressure, pulmonary vascular resistance (PVR), mean systemic arterial blood pressure, systemic vascular pressure (SVR), and PVR/SVR ratio with decreases in cardiac output and stroke volume. ATP-MgCl2 caused significant reduction in mean pulmonary artery pressure (p < 0.001), PVR (p < 0.0001), mean systemic arterial blood pressure (p < 0.003), SVR (p < 0.01), and PVR/SVR ratio (p < 0.03) with improvement in cardiac output (p < 0.001) and stroke volume (p < 0.01). The partial pressure of arterial O2 (p < 0.04), and pH (p < 0.001) were higher and the partial pressure of arterial CO2 (p < 0.02) lower in ATP-MgCl2-treated animals. Also dynamic lung compliance was higher (p < 0.001) and pulmonary airway resistance lower (p < 0.001) in treated animals. Median survival in control animals was 153 min, whereas all treated animals survived to 240 min (p < 0.001). These data demonstrate that ATP-MgCl2 ameliorates the deleterious cardiopulmonary manifestations of GBS sepsis and results in improved survival in a young animal model.

Adenosine Triphosphate↗
PubMed1996

Evaluation of stress-inducible hsp90 gene expression as a potential molecular biomarker in Xenopus laevis.

In this study we have evaluated stress-inducible hsp90 mRNA accumulation as a potential molecular biomarker in Xenopus laevis. In order to obtain a probe for Northern blot analysis we employed a PCR-based approach using degenerate primers for the amplification and cloning of an hsp90 gene sequence from Xenopus laevis. The deduced amino acid sequence is 102 amino acids in length and exhibited the highest degree of identity with zebrafish and human hsp90 beta genes. Furthermore, the putative intron and exon boundaries of this fragment are the same as hsp90 beta in chicken, mouse and human, indicating that the fragment represents a Xenopus hsp90 beta-like gene. Northern blot analyses revealed that this gene was constitutively expressed in cultured A6 cells. While heat shock and sodium arsenite exposure resulted in the increased accumulation of hsp90 mRNA in A6 cells, treatment with cadmium chloride and zinc chloride did not. Also, exposure of A6 cells to concurrent heat shock and sodium arsenite produced a mild synergistic response with respect to hsp90 mRNA levels in contrast to hsp70 mRNA levels which displayed a strong synergistic effect. Finally, hsp90 mRNA was detected constitutively throughout early embryogenesis but was heat-inducible only in late blastula and later stages of development. Given the normal abundance and limited stress-induced accumulation of hsp90 mRNA, it may not have a great deal of potential as a molecular biomarker compared to hsp70 and hsp30 mRNA. However, it may be useful in conjunction with other stress protein mRNAs to establish a set of biomarker profiles to characterize the cellular response to a stressful or toxic agent.

Amino Acid Sequence↗
PubMed1996

Long-term (1980-94) population trends of pestiferous Chironomidae (Diptera) along a lakefront in central Florida.

Populations of adult chironomids occurring along 5-6 km of waterfront in the city of Sanford facing Lake Monroe, central Florida, were monitored from January 1980 to December 1994 using New Jersey light traps. The annual mean number of total midges per trap per day ranged from 269 (1994) to 8,009 (1980). Among the more than 20 species of midges occurring in the traps, Glyptotendipes paripes was the most abundant, followed by Chironomus crassicaudatus. These 2 species comprised 95.6% of total midges collected. Annual cycles of midge abundance were positively correlated with air temperature. Maxima of most species occurred in late spring/early summer; G. paripes peaked in late summer. Year-to-year midge population levels showed significant inverse correlations with Lake Monroe water depth and annual rainfall in the Sanford area.

Animals↗
PubMed1996

Steroids conjugated to bovine serum albumin as tools to demonstrate specific steroid neuronal membrane binding sites.

Our laboratory has pioneered the use of bovine serum albumin (BSA) linked to different positions of the ring structure of progesterone to investigate steroid-membrane interactions. The complex can be radioiodinated to demonstrate the existence of specific membrane progesterone binding sites in the rat brain. Not only are these progesterone complexes specific ligands, but they also elicit functional responses in the central nervous system (CNS), particularly in the corpus striatum (CS) where progesterone-BSA conjugates linked at C-3 and C-11 positions (P-3-BSA and P-11-BSA) alter amphetamine-evoked dopamine release. In this communication we will report our current studies that use radioiodinated progesterone-BSA conjugates (P-3-125I-BSA, P-6-125I-BSA, and P-11-125I-BSA) and estradiol-BSA conjugates linked at C-6 position (17 beta-E-6-125I-BSA and 17-E-6-BSA) to demonstrate the existence of specific membrane binding sites for progesterone and estrogen in several regions of the rat brain. In addition, initial studies to isolate and purify these membrane binding sites from digitonin-solubilized P2-membrane fractions by affinity chromatography are reported. The data indicate that these sites are part of a complex membrane receptor for either estrogen or progesterone, the so-called membrane estrogen receptor (mER) and the membrane progesterone receptor (mPR), respectively.

Animals↗
PubMed1995

Relapsing invasive group B streptococcal infection in adults.

OBJECTIVE: To study recurrent group B streptococcal infection in adults. DESIGN: Patients with more than one reported group B streptococcal infection were identified through active surveillance for this infection. Sterile-site group B streptococcal isolates were evaluated for serotype and molecular subtyping using restriction endonuclease analysis of chromosomal DNA (REAC). SETTING: All acute-care hospitals in Maryland. PATIENTS: Nonpregnant residents of Maryland 18 years of age or older. RESULTS: 22 adults had at least two group B streptococcal episodes that were separated by 2 to 95 weeks (mean, 24 weeks). Of 395 patients with invasive group B streptococcal infection who survived the first episode and were followed for at least 1 year, 17 (4.3% [95% CI, 2.6% to 6.9%]) had more than one episode. Several patients were found to have endocarditis or osteomyelitis during the second episode. Group B streptococcal isolates from both episodes were obtained from 18 of 22 patients. Of the 18 isolate pairs, 13 (72% [CI, 46% to 90%]) had identical REAC patterns; the probability that at least 13 matches would be found by chance alone was less than 0.000001. Among patients with recurrent infection caused by the same strain, the interval between episodes was shorter (mean, 14 weeks) than that among patients with recurrent infection caused by another strain (mean, 43 weeks; P = 0.05). CONCLUSIONS: Recurrent group B streptococcal infection is common among adults and in most cases appears to be caused by relapse. The optimal management of adults with a first episode of group B streptococcal infection needs to be further defined to minimize the likelihood of recurrent disease.

Adolescent↗