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Biomedical subjects

M Husain

Publications and source records attributed to M Husain.

At least 127 records · Page 7Linked to original sources
PubMed1993

A study of effects of putative neurotransmitters injected into the lateral cerebral ventricle of man.

1. The study was carried out in adult patients having normal cardiovascular reflexes and no brain stem lesions. They were exposed to ambient temperature of 72-74 degrees F. Injections of agonists and antagonists of receptors were made into the lateral cerebral ventricles of these patients through diagnostic burr hole in the skull. 2. Noradrenaline, adrenaline and dopamine evoked hypotension and bradycardia. While the core temperature was reduced by nor-adrenaline and adrenaline, dopamine evoked hyperthermia. Isoprenaline elicited hypertension, tachycardia and hyperthermia. Opposite cardiovascular and thermal effects were observed with blockade of alpha 1-, beta-and dopamine receptors with prazosin, propranolol and haloperidol respectively. 3. Injection of 5-hydroxytryptamine resulted in hypertension, tachycardia and hyperthermia but hypotension, bradycardia and hypothermia were seen with methysergide. 4. Similarly, carbachol injection caused initial excitatory followed by inhibitory cardiovascular responses. These were associated with hypothermia. On the contrary atropine per se elicited hypertension, tachycardia and hyperthermia. 5. Thus, alpha 1- and beta-adrenoceptors, dopaminergic, serotonergic and muscarinic cholinergic receptors are present in human brain which appear to modulate cardiovascular activity and core temperature.

Adult↗
PubMed1993

Temporal variation in the distribution of rotavirus electropherotypes in Delhi, India.

The present study was carried out to investigate the varying pattern of rotavirus electropherotypes in Delhi, India. During a 25-month study period, rotavirus was detected in 104 of 990 (10.5%) samples collected from children with acute gastroenteritis, except in the months of June 1988, June 1989, October 1989, January 1990 and March 1990. Viral RNA migration was studied by PAGE in 83 rotavirus positive samples, and 69 (83.1%) of them gave a discernible RNA pattern. A "long" RNA pattern was observed in 58 (84%) and a "short" RNA pattern in 11 (16%) samples. There were three major electropherotypes among the "long" RNA types and two major electropherotypes among the "short" RNA RNA types. Sequential appearance of electropherotypes was seen with every seasonal peak of infection.

Acute Disease↗
PubMed1992

Automated microparticle enzyme immunoassay for neural thread protein in cerebrospinal fluid from Alzheimer's disease patients.

An automated microparticle enzyme immunoassay (MEIA) with the IMx analyzer for the detection of neural thread protein (NTP) in cerebrospinal fluid (CSF) from Alzheimer's disease (AD) patients was developed. This assay uses monoclonal antibodies produced against the purified pancreatic form of the protein. The assay employs one monoclonal antibody covalently coupled to the microparticle to capture immunoreactive material in CSF or brain tissue. The second monoclonal antibody was conjugated to alkaline phosphatase and serves as detection antibody. The assay provides results in approximately 45 minutes with a sensitivity of 60 pg/ml (3 fmoles/ml). The titration curve of both normal and AD CSF resulted in a linear relationship with respect to the volume of CSF used. A similar relationship was observed when normal and AD brain tissue extracts were serially diluted. The molecular weight of NTP in CSF was approximately 20 kD as determined by gel filtration method under non-denaturing conditions. The recovery for pancreatic thread protein (PTP) spiked in either normal or AD CSF was 104% and 108%, respectively. Intra-, inter-, and total assay CVs (coefficient of variation) for controls were less than 2.9%, 3.3% and 3.0%, respectively. This assay will provide a useful tool in the study of the Alzheimer's disease and may help research in diagnosis and prognosis of Alzheimer's disease and related disorders.

Alzheimer Disease↗
PubMed1992

Isolated olfactory groove neurilemmoma.

A case of neurilemmoma arising from the olfactory groove presenting with headache, vomiting, and visual impairment in a thirty-seven-year-old man is reported. His clinical manifestations are described, with a brief review of three other cases reported in the literature so far.

Adult↗
PubMed1992

Meningioma and sagittal craniosynostosis in an infant: case report.

The occurrence of a frontal base meningioma in a 3-month-old infant seen for the treatment of sagittal craniosynostosis is reported. The association of the two lesions is of interest both because it is unique and may lend support to theories of the cause of some forms of craniosynostosis.

Age Factors↗
PubMed1991

Should cervical cytologic testing be augmented by cervicography or human papillomavirus deoxyribonucleic acid detection?

Criticism of the Papanicolaou smear in the lay press and recent federal legislation regulating cytology laboratories indicate a need to reappraise cervical cancer screening programs. This study directly compares three potential screening tests, used alone or in combination. A total of 1012 women aged 18 to 35 years were screened by cytologic testing, cervicography, and hybridization for human papillomavirus deoxyribonucleic acid, with discrepancies being referred by the last two authors. After findings from the entire lower genital tract were combined, 116 women (11.5%) showed definite clinical abnormalities (either exophytic vulvovaginal condylomas or cervical squamous intraepithelial lesions). Another 72 (7.2%) had positive Southern blot hybridizations without accompanying viral expression, yielding a cumulative frequency for established disease or latent infection of 18.6%. When associated vulvovaginal condylomas are disregarded, final groupings with regard to cervical pathologic classification were: 23 high-grade and 71 low-grade squamous intraepithelial lesions, 164 cases of equivocal atypia (34 of which had detectable human papillomavirus deoxyribonucleic acid), and 754 cases with negative results (38 of which had detectable human papillomavirus deoxyribonucleic acid). Cervical screening tests were compared principally by plotting increasingly liberal recall criteria onto receiver operating characteristic curves (i.e., graphs of true-positive results on the Y axis versus false-positive results on the X axis). Used individually, each screening test was valid, but none was substantially better than the others. No matter how liberal the recall criteria, no single test was able to detect all of the 23 definite precursors in this sample. Applying conventional recall criteria (i.e., high- or low-grade lesion suspected), cytologic testing alone detected 12 high-grade squamous intraepithelial lesions (52.2%), at a cost of having to perform colposcopy in 8.7% of the sample. Combining all three tests and setting the end point as just a high-positive result by at least one test, 19 high-grade squamous intraepithelial lesions (83%) were detected, with a recall of 7%. Optimal test performance (96% sensitivity, 4% recall) would have been attained by recalling all patients with high-grade cytologic results or positive cervicography results, plus any patients with low-grade morphologic atypia in which hybridization detected an oncogenic human papillomavirus type. Our conclusions are as follows: (1) Cytologic detection rates are markedly improved by a second or third test; (2) increased screening costs could be offset by not recalling patients with minor lesions with no apparent potential for progression.

Adolescent↗
PubMed1991

Bilateral ectopic gestations.

Bilateral ectopic gestations are a rare form of double ovum pregnancy. The following case report of a patient with a ruptured ectopic gestation of the left fallopian tube and an unruptured ectopic gestation of the right fallopian tube is presented to demonstrate the importance of thoroughly examining the entire pelvis at the time of exploratory laparotomy undertaken for suspicion of ectopic pregnancy.

Adult↗
PubMed1991

Human perception of structure from motion.

Novel dynamic random-do displays representing a rotating cylinder or a noise-field were used to investigate the perception of structure from motion (SFM) in humans. The finite lifetimes of the points allowed the study of spatiotemporal characteristics with smoothly moving stimuli. In one set of experiments subjects had to detect the change from the unstructured motion to the appearance of the cylinder in a reaction time task. In another set of experiments subjects had to distinguish these two stimuli in a two-alternative forced-choice task. The two major findings were: (1) a relatively constant point lifetime threshold (50-85 msec) for perceiving structure from motion. This threshold is similar to the threshold for estimating velocity and suggests that velocity measurements are used to process SFM; (2) long reaction times for detecting structure (approximately 1 sec). The build-up of performance with time and with increasing numbers of points reflects a process of temporal and spatial integration. We propose that this integration is achieved through the generation of a surface representation of the object. Information from single features on the object appears to be used to interpolate a surface between these local measurements allowing the system to improve perception over extended periods of time even though each feature is present only briefly. Selective masking of the stimulus produced characteristic impairments which suggest that both velocity measurements and surface interpolation are global processes.

Form Perception↗
PubMed1991

A magnetic resonance image study of age-related changes in human putamen nuclei.

Putamen nuclei were assessed in 36 normal volunteers using magnetic resonance imaging and a systematic sampling method. There was a significant decrease in the volume of the putamen nuclei with advancing age (r = -0.74, p less than 0.0001), and an associated decline in the volume of the caudate nuclei (r = 0.60, p less than 0.0001). The implications of these findings in age-associated motor abnormalities are discussed.

Adult↗
PubMed1991

Do obstetrical charts present a liability risk?

The practice of obstetrics is well-known as a medicolegal, high-risk profession. Poor charting is considered an area of serious deficiency for physicians and especially for obstetricians. We reviewed the charting practices of obstetricians in a level II community hospital. The traditional 1- and 5-minute Apgar scores were employed as the screening criteria. Apgar scores of 7 or lower at 5 minutes were used to identify charts considered vulnerable to litigious activity. Of 1437 deliveries, 115 charts with 5-minute Apgar scores of 7 or lower were reviewed. Traditional requirements for charting, eg, history and physical exams, admission notes and diagnoses were recorded fairly consistently. However, elements such as statements of judgment, autopsy reports, scalp pHs, and extended Apgar scores that would render a chart defensible were sorely lacking. Charting skills, not necessarily the quality of care, may render obstetricians medicolegally vulnerable.

Apgar Score↗
PubMed1990

Spectral and electrochemical properties of glutaryl-CoA dehydrogenase from Paracoccus denitrificans.

Studies of the spectral (UV/vis and resonance Raman) and electrochemical properties of the FAD-containing enzyme glutaryl-CoA dehydrogenase (GCD) from Paracoccus denitrificans reveal that the properties of the oxidized enzyme (GCDox) appear to be invariant from those properties known for other acyl-CoA dehydrogenases such as mammalian general acyl-CoA dehydrogenase (GACD) and butyryl-CoA dehydrogenase (BCD) from Megasphaera elsdenii. However, when either free or complexed GCD is reduced, its spectral and electrochemical behavior differs from that of both GACD and BCD. Free GCD does not stabilize any form of one-electron-reduced GCD, but when GCD is complexed to its inhibitor, aceto-acetyl-CoA, the enzyme stabilizes 20% of the blue neutral radical form of FAD (FADH.) upon reduction. Like GACD, when crotonyl-CoA- (CCoA) bound GCD is reduced, the red anionic form of FAD radical (FAD.-) is stabilized, and excess reduction equivalents are necessary to effect full reduction of the complex. A comproportionation reaction is proposed between fully reduced crotonyl-CoA-bound GCD (GCD2e-CCoA) and GCDox-CCoA to partially explain the stabilization of GCD-bound FAD.- by CCoA. When GCD is reduced by its optimal substrate, glutaryl-CoA, a two-electron reduction is observed with concomitant formation of a long-wavelength charge-transfer band. It is proposed that the ETF specific for GCD abstracts one electron from this charge-transfer species and this is followed by the decarboxylation of the oxidized substrate. At pH 6.4, potential values measured for free GCD and GCD bound to acetoacetyl-CoA are -0.085 and -0.129 V, respectively. Experimental evidence is given for a positive shift in the reduction potential of GCD when the enzyme is bound to a 1:1 mixture of butyryl-CoA and CCoA. However, significant GCD hydratase activity is observed, preventing quantitation of the potential shift.

Chemical Phenomena↗
PubMed1990

Specialization of the right hemisphere for visuomotor control.

The accuracy of saccades directed towards the remembered positions of targets in left (LVF) or right (RVF) visual hemifield was measured. The majority of right-handed subjects were found to be more accurate at directing their gaze to locations in the LVF than in the RVF, suggesting that the right hemisphere is superior to the left in oculomotor control. Even after completion of a corrective saccade following the primary saccade, subjects systematically undershot target direction and overshot target depth, suggesting that visual feedback normally plays an important role in the fine guidance of gaze after the completion of a primary saccade.

Adult↗
PubMed1990

Sexually transmitted papillomaviral infection in the male: VI. Simultaneous urethral cytology-ViraPap testing of male consorts of women with genital human papillomaviral infection.

A series of 122 males at high risk for development of human papillomavirus (HPV) infection were prospectively studied with simultaneous urethral brushing cytology and ViraPap, to establish their relative sensitivity and specificity in relation to the diagnosis of HPV infection in the urethral canal. The prevalence of disease in this high-risk population was 10 percent. The sensitivity of DNA hybridization was determined to be 67 percent, with a 100 percent specificity, as compared with a 25 percent sensitivity of cytologic analysis. Physical examination alone had a 75 percent sensitivity. Physical examination with ViraPap urethral analysis identified all patients with urethral HPV-associated disease. These results indicate that clinical examination alone misses one quarter of the HPV-involved patients.

Colposcopy↗
PubMed1990

A Bangladeshi family with three sisters 'Bombay' or Oh phenotype.

Three sisters in a same family (MIAH FAMILY) are of 'Bombay' phenotype. These being the first known female examples of 'Bombay' blood group have been detected in Bangladesh. As predicted by current theory their red cells are Le(a+b-) and their saliva do not contain any of the antigens A, B and H except Lea substance. Family studies showed that individuals with 'Bombay' or Oh phenotype may have A or B gene which are not expressed. This very particular type of blood is one of the rarest in any other parts of world except in India. Due to the presence of anti-H antibody in the plasma of Oh phenotype, when considering such patients for transfusion only blood of identical Bombay type can be safely transfused.

ABO Blood-Group System↗
PubMed1990

Contribution of intraoperative pathology evaluation to surgical management of thyroid nodules.

With adequate experience, needle biopsy findings become as reliable or more so than frozen section diagnoses for surgical planning. Each institution must determine for itself the relative reliability of these two procedures before establishing management policies. Reduction or elimination of useless or redundant frozen section procedures reduces costs as well as anesthesia duration.

Biopsy, Needle↗
PubMed1989

Unusual redox properties of electron-transfer flavoprotein from Methylophilus methylotrophus.

The most positive redox potential ever recorded for a flavin adenine dinucleotide (FAD) containing protein has been measured for an electron-transfer flavoprotein (ETF) synthesized by Methylophilus methylotrophus. This potential value, 0.196 V versus the standard hydrogen electrode (vs SHE), was measured at pH 7.0 for the one-electron reduction of fully oxidized ETF (ETFox) to the red anionic semiquinone form of ETF (ETF.-). Quantitative formation of ETF.- was observed. The first successful reduction of ETF from M. methylotrophus to its two-electron fully reduced form was also achieved. Although addition of the second electron to ETF.- was extremely slow, the potential value measured for this reduction was -0.197 V vs SHE, suggesting a kinetic rather than thermodynamic barrier to two-electron reduction. These data are believed to be consistent with the postulated catalytic function of ETF to accept one electron from the iron-sulfur cluster of trimethylamine dehydrogenase (TMADH). The second electron reduction appears to have no catalytic function. The very positive potential measured for this ETF and the wide separation of potentials for the two electron reduction steps show that this ETF is a unique and interesting flavoprotein. In addition, this work highlights that while ETFs exhibit similar structural and spectral properties, they display wide variations in redox properties.

Bacteria↗