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Biomedical subjects

Z Khan

Publications and source records attributed to Z Khan.

At least 19 recordsLinked to original sources
PubMed1999

Pilocarpine tablets for the treatment of dry mouth and dry eye symptoms in patients with Sjögren syndrome: a randomized, placebo-controlled, fixed-dose, multicenter trial. P92-01 Study Group.

BACKGROUND: Patients with Sjögren syndrome (SS) experience slowly progressive infiltration of lacrimal and salivary glands by mononuclear cells. This leads to diminished secretions, with resultant symptoms of xerostomia and xerophthalmia. Although pilocarpine hydrochloride tablets are currently indicated for the treatment of radiation-induced xerostomia, their effects on dry mouth or dry eyes in patients with SS are unclear. OBJECTIVE: To assess the safety and efficacy of pilocarpine (Salagen) tablets as symptomatic treatment for dry mouth and dry eyes caused by SS in a multicenter, doubleblind, placebo-controlled trial. METHODS: After providing written informed consent, 373 patients with primary or secondary SS and clinically significant dry mouth and dry eyes were randomized to receive 2.5-mg pilocarpine, 5-mg pilocarpine, or placebo tablets 4 times daily for 12 weeks. Symptoms were assessed by questionnaires with visual analog scales or categorical checkboxes. Whole-mouth salivary flow rates were measured. RESULTS: A significantly greater proportion of patients in the 5-mg pilocarpine group showed improvement compared with the placebo group (P< or =.01) in global assessments of dry mouth, dry eyes, and other symptoms of dryness (P< or =.05). Salivary flow was significantly increased 2- to 3-fold (P<.001) after administration of the first dose and was maintained throughout the 12-week study. The most common adverse effect was sweating, and no serious drug-related adverse experiences were reported. CONCLUSION: Administration of 5-mg pilocarpine tablets 4 times daily (20 mg/d) was well tolerated and produced significant improvement in symptoms of dry mouth and dry eyes and other xeroses in patients with SS.

Adult↗
PubMed1999

Effect of congestive heart failure on in vivo canine aortic elastic properties.

OBJECTIVES: The aim of this study was to characterize fully in vivo aortic compliance over a wide range of passive distending pressures, and to study pharmacologically induced alterations in compliance using an intravascular ultrasound-based technique in the canine model of heart failure. BACKGROUND: Altered aortic compliance may influence considerably the function of the failing heart. Although some studies demonstrate that patients with heart failure have decreased aortic compliance, data from other studies are conflicting. METHODS: Aortic pressures and dimensions in seven dogs were determined both before and after pacing-induced congestive heart failure (CHF) using simultaneous micromanometer and intravascular ultrasound transducers. Decreases in aortic pressure were produced at baseline and after nitroprusside and dobutamine infusions. Inner and outer aortic circumferences were drawn at the lumen-intimal and media-adventitial borders. RESULTS: Aortic pressure-dimension (chamber) stiffness constants were greater after heart failure was produced (10.0+/-1.5 vs. 6.7+/-1.5, p < 0.05), but stress-strain stiffness (material) constants were similar (11.4+/-1.8 vs. 11.3+/-1.0, p=NS). Equivasodilating doses of nitroprusside and 10 microg/kg/min dobutamine decreased pressure-dimension stiffness constants after pacing-induced heart failure but not beforehand. The aortic wall thickness to diameter ratio was significantly greater in CHF than in the control condition (0.30+/-0.08 vs. 0.16+/-0.03, p < 0.01). CONCLUSIONS: Aortic compliance is decreased in this model of CHF, and this change is attributable primarily to vessel geometry rather than material properties. Equivasodilating doses of nitroprusside and equivalent doses of dobutamine increase aortic chamber compliance in dogs with CHF, but not in normal dogs. These data suggest that the beneficial effects of nitroprusside and dobutamine in CHF occur in part from improvement in aortic compliance.

Animals↗
PubMed1998

Cattle plague in Shangri-La: observations on a severe outbreak of rinderpest in northern Pakistan 1994-1995.

Between April 1994 and November 1995 the most severe epidemic of rinderpest reported in the world for over a decade affected domestic livestock in the Northern Areas of Pakistan. As many as 40,000 cattle and yaks died, more by some estimates, and mortality rates may have exceeded 80 per cent in these species in several villages. This report describes some of the clinicopathological and epidemiological features peculiar to the outbreak, including laboratory-confirmed rinderpest in a goat, and the difficulties encountered before the disease was eradicated. It also describes the human costs and emphasises the need to accelerate the global eradication of this most eradicable disease.

Agriculture↗
PubMed1997

Construction of a custom-shaded interim denture using visible-light-cured resin.

A patient treatment is presented to demonstrate a technique using visible-light-cured (VLC) resin to create a characterized denture base for an interim denture. This indication for characterization is routinely seen with African-Americans with dark-pigmented gingiva. Using a combination of blue VLC tray resin and pink VLC denture base resin, the mixture achieves a darker-colored denture base. This technique was used for the fabrication of an interim denture for a patient who required an immediate interim denture. The prosthesis was worn during the healing phase and allowed the patient to function while the definitive prosthesis was being fabricated.

Adult↗
PubMed1997

A baseline study of tobacco use among the staff of Aligarh Muslim University, Aligarh, India.

A cross-sectional study of 2,439 university employees and research scholars was carried out using the questionnaire method. The objective was to assess the prevalence and type of tobacco usage and to collect background data for planning health education programmes. The overall prevalence of tobacco usage was 51.5% among males and 30.3% among females. There were no female smokers, the preferred habit of tobacco usage among women being chewing. The prevalence of smoking among non-teaching staff members was significantly higher. Among females, the prevalence of tobacco chewers was higher in non-teaching staff members. Tobacco usage (both smoking and usage of other forms) rose with age. However, even at 20-30 years of age 25.4% of males were addicted to smoking. A majority of 60.6% had smoked for more than 10 years. Among the staff members (both teaching and non-teaching) the reason for smoking was either to relax or because of addiction, whereas the research scholars smoked to improve their image or for enjoyment/pleasure. The reasons given by users of other forms of tobacco were boredom, to pass the time or for no reason at all. Among non-users, the majority were aware of the harmful effects of smoking. Family pressure and traditions were also important reasons for not smoking. The study provides a clear picture of tobacco usage within the University.

Adult↗
PubMed1996

Long-term benefits of aggressive treatment for primary colorectal cancer.

The long-term follow up of 128 colorectal cancer patients is reported. Seventy-nine percent (101/128) of the patients had curative resections: 70 patients had radical lymphadenectomies with wide removal of tumor-adjacent nodes, and 31 patients had standard resections. The 5-year overall survival rates for Dukes' stage B and C patients and for all rectosigmoid cancer patients significantly favored radical resection (60% vs. 38%, 57% vs. 29%, respectively, P < 0.05). Tumor-free survival rates were also higher after radical lymphadenectomy but did not reach statistical significance. Eleven percent (14/128) of the patients required multiorgan resections, and/or preoperative radiation to render fixed cancers resectable, and these patients had a 10-year tumor-free survival rate of 45%, compared to zero % 5-year survival for the 27 patients who underwent palliative procedures (P < 0.01). These results confirm that many colorectal cancer patients will be cured with aggressive treatment and they support the need for a controlled trial for evaluation of lymphadenectomy for this disease.

Adult↗
PubMed1996

Role of weaning in the nutritional status of infant--a longitudinal study in the rural area of Aligarh.

Influences of weaning practices on nutritional status were studied in a cohort of 200 infants over a period of one year in the rural area of Aligarh. Weaning was late in most of the infants under study. The nutritional status of infants up to 6 months was significantly better than that of infants more than 6 months of age. Most of them used the family-type food as weaning food.

Developing Countries↗
PubMed1995

Simultaneous assessment of cell kinetics and programmed cell death in bone marrow biopsies of myelodysplastics reveals extensive apoptosis as the probable basis for ineffective hematopoiesis.

Despite hypercellular bone marrows (BM), peripheral cytopenias are the rule in patients with myelodysplastic syndromes (MDS). This study examined the roles played by cell birth and cell death rates in generating this paradox. Cell kinetics from BM biopsies of 35 MDS patients were measured using intravenous infusions of either iododeoxyuridine or bromodeoxyuridine, or both. Degree of apoptosis or programmed cell death (PCD) was estimated using in situ end-labeling of DNA directly from BM biopsies, which were simultaneously double-labeled from proliferation/PCD. MDS were found to be highly proliferative disorders with large numbers of myeloid, erythroid, and megakaryocytic cells synthesizing DNA. Median cycling time (Tc) of myeloblasts was more rapid than that of patients with acute myeloid leukemia (44.1 hr vs. 56.0 hr). Interestingly, most marrow cells of all three lineages in 32 of 34 evaluable cases were undergoing PCD. In 19 of 32 patients, greater than 75% cells were apoptotic. Surprisingly, large numbers of S-phase cells were found to be simultaneously undergoing PCD, as were stromal cells of the BM microenvironment. We conclude that the extensive apoptosis in hematopoietic cells effectively cancels the high birth rate resulting in ineffective hematopoiesis and accounting for deficient bone marrow function.

Acute Disease↗
PubMed1995

Fate of the upper urinary tract in multiple sclerosis.

Urologic problems are a major source of morbidity for patients with multiple sclerosis (MS). Fifty-four to 78% of patients experience bladder symptoms which are due to spinal lesions interrupting neural pathways that control micturition. MS patients could have upper or lower motor neuron lesion type bladders. Both obstructive and irritative symptoms may be present. Although lower urinary tract dysfunction has been well described in MS, few studies have investigated the fate of the upper urinary tract. Thirty-two patients with MS were referred for urodynamic evaluation. Twenty-six of the 32 patients had upper urinary tract studies performed. Only 1 of the 26 patients had evidence of upper urinary tract deterioration. It is our impression that upper tract deterioration occurs infrequently in these patients. We discuss clinical clues that may predict deterioration.

Adult↗
PubMed1995

Anatomic site evaluation of edentulous maxillae for dental implant placement.

PURPOSE: This study evaluated 17 edentulous cadavers for bone quantity and quality of the alveolar process of the maxilla for the purpose of dental implant placement. MATERIALS AND METHODS: The maxillary arch was divided into four anatomically defined regions for measurements of bone quantity. Bone quality was assessed histologically and described by trabecular bone patterns and tissue composition. RESULTS: Average bone height with a minimum thickness of 4 mm was as follows: region 1, 12.1 +/- 4.9 mm; region 2, 14.1 +/- 7.2 mm; region 3, 6.1 +/- 2.8 mm; and region 4, 8.5 +/- 2.2 mm. Histological evaluation showed increased trabeculation and thicker cortex in the maxillary anterior area, regions 1 and 2. Region 3, the floor of the maxillary sinus area, had the least amount of bone; however, the quality of bone was superior to that of region 4, the maxillary tuberosity area. Trabecular distance or marrow spaces ranged from 40 microns to 2 mm with larger spaces associated with the posterior maxilla. CONCLUSIONS: Maxillary tuberosity is the least desirable site for the placement of implants in the maxilla. The area corresponding to the first and second molars had the least bone thickness. All measures of bone preservation need to be considered, especially in this area.

Aged↗
PubMed1994

Molecular heterogeneity of the type I GABAA/benzodiazepine receptor complex.

We have investigated the presence of alpha 1, gamma 2 and beta 2-3 subunits as part of the type I (high affinity for [3H]zolpidem) GABAA/benzodiazepine receptor from rat cerebral cortex. Three subunit specific antibodies have been used (anti-alpha 1, to the C-terminal of rat alpha 1 subunit; anti-gamma 2, to the large intracellular loop of the gamma 2 subunit short form and the monoclonal 62-3G1, specific to beta 2-3 subunits) in immunoprecipitation experiments of the [3H]zolpidem binding activity or the 51,000 Da [3H]Ro 15-4513 photoaffinity labeled peptide (P51). The results indicated that alpha 1 subunit was present in the whole population (90%) of the GABAA/benzodiazepine receptors with high affinity for [3H]zolpidem. We cannot exclude the presence of other alpha subunits co-localized with alpha 1. On the one hand, 70-75% of type I GABAA/benzodiazepine receptor from rat cortex have co-existing alpha 1, beta 2-3 and gamma 2 subunits. We call this type Ia. On the other hand, 20-25% of the type I GABAA/benzodiazepine receptor complex should be constructed by the association of alpha 1 with subunits other than beta 2-3 and gamma 2. We call this type Ib. The identity of these subunits is currently unknown.

Animals↗
PubMed1994

Modified bar superstructure for an implant-retained orbital prosthesis.

The success of a bar superstructure for an orbital prosthesis may be compromised by the placement and angulation of implants. The following technique describes a modification to a bar superstructure that provided the advantages of convenience, security, and consistent positioning even though one implant was lost and the angulation of implants limited accuracy.

Eye, Artificial↗
PubMed1994

Active management of preterm labour and preterm prelabour rupture of membranes.

Hundred cases of preterm labour (before 36 weeks) with cervix 4 cm or less dilated and preterm prelabour rupture of membranes (excluding cases of uterine overdistension, maternal medical disorders and fetal congenital abnormalities) were treated with bed rest and sedation. Labour set in within 2-6 days with high fetal morbidity and mortality. Another fifty similar patients were given in addition to rest in hospital for 48 hours, 1000 ml of 5% dextrose in six hours, intravenous antibiotics (after sending off cultures from the vagina per speculum), corticosteroids and a single dose of analgesia/sedation injection. In 85% painful contractions ceased and membranes stopped leaking until near term. In 10% painful contractions ceased, but leakage continued for 2-7 weeks, and the gain in intrauterine life led to 100% neonatal survival with short hospital stay in the neonates born after 31 weeks. Only 5% failed to respond to treatment and after delivery these premature neonates developed pneumonia and septicaemia from the same organisms that were colonizing their maternal genital tract and had entered the fetus via the infected amniotic fluid. It is recommended that all patients in preterm labour or preterm prelabour rupture of membranes (excluding overdistension) be given besides bed rest and sedation, corticosteroids and antibiotics intravenously for 48 hours and then orally for eight more days. Tocolytics are not recommended. This regime saves babies.

Analgesics↗
PubMed1993

Isolation and identification of N-terminally extended forms of 5-oxoprolylglutamylprolinamide (Glp-Glu-Pro-NH2), a thyrotropin-releasing-hormone (TRH)-like peptide present in human semen.

N-terminally extended forms of 5-oxoprolylglutamylprolinamide (Glp-Glu-Pro-NH2), a thyrotropin-releasing-hormone(TRH)-like peptide associated with the male reproductive system, were isolated from human semen by gel exclusion on Sephadex G50, ion-exchange chromatography on SP-Sephade C25 and QAE-Sephadex A25, and by HPLC. The peptides were located by trypsin-catalysed release of their C-terminal fragments which were detected by RIA with a TRH-specific antibody. A series of overlapping peptides containing 16, 18, 22 and 25 residues was obtained in homogeneous form and their sequences were determined by automatic Edman degradation. The peptides all terminated in -Lys-Gln-Glu-Pro-NH2 and were found to correspond to sequences occurring between residues 350-374 of semenogelin, a protein present in human semen. In semenogelin, however, the Gln-Glu-Pro sequence is followed by tryptophan and not glycine which is normally essential for formation of the C-terminal amide group. Model experiments with the synthetic peptide Glp-Glu-Pro-Trp showed that under a range of experimental conditions the tetrapeptide did not undergo conversion to Glp-Glu-Pro-NH2. This would indicate that the tripeptide and its extended forms are generated from a precursor that is related to semenogelin but in which Trp375 is replaced by glycine.

Amino Acid Sequence↗
PubMed1993

Role of detrusor instability in primary enuresis.

We studied 50 enuretic boys and girls by supine cystometry. Detrusor instability was found in 74 percent of the cases. The mean threshold volume at which detrusor instability was demonstrated was 200 mL. The mean bladder capacity of age-matched nonenuretic children was 325 mL. We consider detrusor instability at this reduced threshold volume to be the main cause of primary enuresis.

Adolescent↗