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Biomedical subjects

S Husain

Publications and source records attributed to S Husain.

At least 91 records · Page 5Linked to original sources
PubMed1993

Immobilization and stabilization of invertase using specific polyclonal antibodies.

Antisera raised in rabbits to baker's-yeast invertase significantly activated the enzyme in vitro. The antisera contained precipitating antibodies, a significant fraction of which appeared to be directed against the glycosyl residues of the enzyme. Invertase could be immobilized as insoluble enzyme antibody adducts or by binding to a Sepharose matrix precoupled with the gamma-globulin fraction derived from the antisera. The immobilized invertase preparations exhibited high enzyme activity and had markedly enhanced thermal stability, which could be further improved by cross-linking with glutaraldehyde.

Animals↗
PubMed1992

Monoclonal antibody OPD4 detects neoplastic T cells but does not distinguish between CD4 and CD8 neoplastic T cells in paraffin tissue sections.

Monoclonal antibody (MoAb) OPD4, reported to preferentially react with benign CD4 T cells in formalin-fixed tissue sections, was examined for its reactivity with 56 T-cell neoplasms after formalin or Bouin's fixation to determine if it also preferentially detects neoplastic CD4 T cells in paraffin tissue sections. Monoclonal antibody OPD4 did not preferentially detect neoplastic CD4 T cells, since it reacted with 22 of 38 (58%) CD4-positive compared with nine of 14 (64%) CD4-negative T-cell neoplasms. However, MoAb OPD4 appears to detect neoplastic T cells in Bouin's-fixed (11 of 20 cases [55%]) about as well as in formalin-fixed (20 of 32 cases [63%]) tissues. Since MoAb OPD4 does not preferentially react with neoplastic CD4 T cells, the utility of this MoAb as a pan-T-cell marker in routinely processed tissues was also explored and compared with that of Leu-22, UCHL-1, and CD3. All four antibodies reacted with approximately the same percentage of T-cell malignancies (51% to 57%). However, examination of different clinicopathologic groups and types of fixative highlighted differences. Monoclonal antibodies OPD4 and Leu-22 reacted with 62%, while CD3 detected only 41% of formalin-fixed, postthymic T-cell neoplasms. OPD4, UCHL-1, and CD3 each reacted with 55%, but Leu-22 recognized only 45% of Bouin's-fixed, postthymic T-cell malignancies. OPD4 reacted with none, but CD3 reacted with all four T-cell lymphoblastic lymphomas. Various antibody combinations were examined to determine an optimal panel for the recognition of T-cell neoplasms in paraffin sections. The combination of MoAbs OPD4 and Leu-22 detected 86% of postthymic T-cell neoplasms in formalin-fixed tissue sections. Furthermore, MoAb OPD4 appears to be relatively specific for T-cell neoplasms, detecting 31 of 56 (55%) T-cell malignancies, while only reacting with two of 39 (5%) B-cell neoplasms. Therefore, while not preferentially reactive with neoplastic CD4 T cells, MoAb OPD4 may be useful as a pan-T-cell marker of postthymic T-cell neoplasms in routinely processed, formalin-fixed tissues, especially when used in conjunction with MoAb Leu-22.

Antibodies, Monoclonal↗
PubMed1992

An analysis of prognostic factors in cutaneous neuroendocrine carcinoma.

Since the first report of cutaneous neuroendocrine carcinoma (Merkel cell carcinoma) in 1972, knowledge of the biological behavior of this tumor has continued to increase. This study reviews three previously unreported cases in addition to reports on 429 patients collected from the literature. The presenting features of these 306 patients were analyzed for frequency and then were analyzed by the Cox proportional hazard model for the relationship of each to recurrence and outcome. This study confirms that cutaneous neuroendocrine carcinoma is an aggressive disease; that the most common cause of death in these patients is by distant metastasis; and that men have succumbed more frequently than women. As a result of this study, aggressive treatment of cutaneous neuroendocrine carcinoma is recommended, especially in the male patient.

Aged↗
PubMed1992

Inactivation and reactivation of horseradish peroxidase immobilized by various procedures.

Horseradish peroxidase (HRP) immobilized by coupling the amino acid side chain amino groups or carbohydrate spikes to the matrix has been studied for its resistance to heat, urea-induced inactivation and ability to regain activity after denaturation in order to understand the influence of the nature of immobilization procedure on these processes. The various immobilized preparations were obtained and their properties studied: Sp-HRP was obtained by direct coupling of HRP to cyanogen bromide-activated Sepharose, Sp-NHHRP by coupling periodate oxidized and diamine-treated enzyme to the cyanogen bromide activated Sepharose, SpNH-COHRP by coupling periodate-treated enzyme to amino-Sepharose and SpCon A-HRP by binding of the enzyme on Con A-Sepharose. All the immobilized preparations exhibited higher stability against heat-induced inactivation as compared to the native HRP. Sp-NHHRP was most stable followed by Sp-HRP, SpNH-COHRP and SpCon A-HRP. Sp-NHHRP was also superior in its ability to regain enzyme activity after thermal denaturation, although Sp-HRP regained maximum activity after urea denaturation. Inclusion of Ca2+ was essential for the reactivation of all preparations subsequent to denaturation by urea.

Enzymes, Immobilized↗
PubMed1991

Massive cluster impact mass spectrometry: a new desorption method for the analysis of large biomolecules.

A new ion desorption method is described that utilizes a primary beam of massive, multiply charged cluster ions to generate secondary ions of peptides in a glycerol matrix. The massive cluster ion beam is generated via electrohydrodynamic emission using a 1.5 M solution of ammonium acetate in 30% aqueous glycerol. Negative ion spectra of peptides obtained using this technique show greatly decreased relative intensities for fragment ions and 'chemical noise' background when compared to spectra obtained using a xenon atom primary beam. The near absence of fragments derived from radiation damage to the sample solution is attributed to the impact of primary particles with energies less than 1 eV/nucleon.

Amino Acid Sequence↗
PubMed1991

Tissue glutathione levels in mice treated with delta-9-tetrahydrocannabinol.

Glutathione (GSH) is widely distributed among living cells and is involved in many biological functions. It provides the sulfhydryl groups for conjugation of toxic metabolites of several xenobiotica. Acetaminophen (Tylenol) toxicity is a classical example of this property. For this purpose, we studied the effects of delta-9-tetrahydrocannabinol (THC) on tissue levels of GSH in the mice. Groups of male Swiss Webster mice weighing 25 +/- 5 g were treated with 50 mg/kg, PO THC at 1300 h. Control mice were given equal volume of sesame oil (5 ml/kg, PO) which was the vehicle for THC. Ninety minutes following THC administration, mice were sacrificed, their plasma, brain, heart, liver, kidney and testis were collected. All tissues were homogenized in 5% TCA/EDTA solution and supernatant solutions of these homogenates were diluted. In these diluted samples, levels of GSH were determined by a modified spectrophotometric procedure and the GSH levels were expressed as micromoles of GSH/g tissue. In this study, THC caused no effects on GSH levels in brain, heart, testis and plasma. However, GSH levels in liver and kidney were decreased by 14% and 7% respectively. Although the decrease in kidney GSH levels were insignificant, these changes in liver and kidney could be indicative of a possible metabolic and/or dispositional interaction between THC and different commonly available drugs such as acetaminophen.

Acetaminophen↗
PubMed1991

Characteristics of cocaine interaction with delta-9-tetrahydrocannabinol on glucose metabolism in the rat testis.

In this study, the characteristics of cocaine (COC) interaction with delta-9-tetrahydrocannabinol (THC) on glucose metabolism in the rat testis were investigated at different time points. Rats receiving 20 mg/kg IP COC at 0830 h and sacrificed at 15 min, 30 min and 60 min posttreatment showed no change in glucose metabolism. Moreover, 5 mg/kg, IV, COC treatment at 0900 h to rats and sacrificed 60 min postexposure, also produced no change in glucose metabolism. However, at 1300 h, the same protocol with IV COC treatment resulted in a significant increase in glucose utilization by the testis. Furthermore, a THC dose of 10 mg/kg, PO to the rats at 0830 or at 1130 h, followed by sacrifice 90 min later caused a significant decrease in glucose utilization at both time points. Similarly, when rats were given both THC and COC (THC at 0830 h, COC 90 min later) and sacrificed 60 min post-COC, it resulted in a further decrease in testicular glucose metabolism as compared to the rats treated by THC alone. On the other hand, concurrent exposure of rats to these drugs at 1300 h with same protocol, ended up with no change in glucose utilization in the testis. These data suggest that not only the route of administration but also the time of exposure plays an important role in defining the nature of the effects of COC/THC interaction on rat testicular glucose metabolism.

Animals↗
PubMed1991

Nasal myiasis in leprosy.

Infestation of the nose with larvae of certain files can occur in leprosy patients. This results in severe distress and agony and can cause extensive tissue damage. The predisposing factors, clinical presentation and treatment is described.

Humans↗
PubMed1991

Psychosocial aspects of deformed leprosy patients undergoing surgical correction.

A psychosocial study was conducted on 25 randomly selected leprosy patients undergoing corrective surgical procedures for their deformities. High anxiety and depression levels found preoperatively, reduced significantly after operation. Psychiatric assistance is needed for these patients in order to clear their psychic aberrations, create awareness, boost morale and to give self-confidence. Only 50-75% of preoperative expectations were satisfied but that was only in 40% of patients. This calls for a preoperative counselling session with the patients to help them reach the realistic goals that they can achieve. They should be told what benefits surgery can offer them and be made aware of the problems which will persist after operation, such as anaesthesia and analgesia.

Adolescent↗
PubMed1990

Immunocytochemical profile of benign and carcinomatous effusions. A practical approach to difficult diagnosis.

One of the great challenges in the cytodiagnosis of effusions is the distinction between reactive mesothelium/histiocytes and cancer cells. This is notably true in patients having undergone radiation and/or chemotherapy. To establish whether monoclonal antibodies (MoAbs) could be used as reliable diagnostic adjuvants, the authors retrospectively and blindly studied 60 cases diagnosed by standard cytologic criteria (malignant, benign, and equivocal), with a panel of seven readily available MoAbs (cytokeratins, vimentin, EMA, B72.3, alpha-CEA, HMFG-2, and Leu-M1) and the lectin Ulex europaeus I. All 18 (100%) malignant cases showed reactivity with EMA and HMFG, whereas 17 (95%) and 11 (61%) reacted with B72.3 and alpha-CEA, respectively. Combinations of (1) EMA + B72.3, (2) EMA + alpha-CEA, and (3) EMA + alpha-CEA + B72.3 displayed positivity in 17 (95%), 11 (61%), and 10 (56%) malignant cases, respectively. Of the 18 benign cases, 7 reacted with HMFG and 2 each with EMA and B72.3. Only one case (5.5%) reacted with both EMA and B72.3. Based on these results, the 24 equivocal cases were regrouped into 14 malignant and 10 benign cases. Follow-up effusions obtained within the ensuing three months in all these patients allowed the authors to unequivocally confirm the diagnosis in all but five. The combination of EMA and B72.3 MoAbs detected malignant cells in 95% of the cases, with a 3.5% incidence of false positive cases in this study. A panel of EMA, B72.3, and alpha-CEA MoAbs should prove the most useful and simple approach to the correct diagnosis in most questionable effusions. Some of the potential pitfalls are discussed.

Antibodies, Monoclonal↗
PubMed1990

Preliminary observations on myiasis in leprosy patients.

Out of 3350 leprosy patients attending the surgical outpatient department for various ulcerative lesions, 18 patients had typical symptoms of myiasis. Maggots were collected in 5 cases from the nose, in 3 cases from ulcers of the hand and in 10 cases from ulcers of the foot. It was possible to rear the maggots into flies in 8 out of 18 cases. The flies were identified as Sarcophaga ruficornis and Chrysomyia bezziana.

Adolescent↗
PubMed1989

Interactive effects of chronic phencyclidine and delta 9-tetrahydrocannabinol on spermatogenesis in mice.

In this study, the combined effects of chronic phencyclidine (PCP) and delta 9-tetrahydrocannabinol on spermatogenesis in mice were examined. Mice were treated with THC (50 mg/kg, PO) and PCP (15 mg/kg, IP) alone or in combination for 16 days and with PCP alone for 35 days. THC had a significant effect on spermatogenesis and decreased the number of all germinal cells. PCP, on the other hand, affected all germinal cells except spermatids after 35 days of treatment. Combination of THC and PCP treatment caused a significant decrease in resting and pachytene spermatocytes. Similarly, combination of these two drugs caused a significant increase in cauda epididymal abnormal sperms. These results suggest that THC and PCP may cause greater disruption in spermatogenesis when they are abused together.

Animals↗
PubMed1989

Effects of delta-9-tetrahydrocannabinol on in vitro energy substrate metabolism in mouse and rat testis.

In this in vitro radiorespirometric study, the effects of delta-9-tetrahydrocannabinol (THC) on glucose and fructose metabolism in the rat and mouse testes were compared. In the rat testis, THC caused a dose-dependent decrease of 15, 18, 20 and 25% in glucose metabolism with 0.1, 0.2 and 0.3 mM concentrations. Similarly, a 39% inhibition in fructose metabolism was observed when rat testes were exposed to 0.3 mM THC. The comparative studies with mouse testis indicated that 0.1, 0.2 and 0.3 mM THC produced a 4, 12 and 30% decrease in glucose utilization where as a much greater decrease of 13, 30 and 41% in fructose utilization was observed with the same doses of THC. On the basis of these observations in these two animal models, it is concluded that THC has the ability to inhibit energy substrates utilization in the rat and mouse testis. This inhibition of cellular energetics may, in part, be responsible for most of the gonadal effects of THC.

Animals↗
PubMed1989

Nerve abscess simulated by a lipoma in a leprosy patient.

A case of suspected giant nerve abscess near the radial nerve in the upper arm of a patient with borderline leprosy is reported. On exploration, it turned out to be a deep seated lipoma. Consideration should be given to exploring nerve masses in leprosy.

Abscess↗
PubMed1987

Sublabial transseptal repair of choanal atresia or stenosis.

Bilateral choanal atresia in newborns and infants carries significant morbidity and mortality, therefore, prompt correction is required. The transnasal route is usually preferred in the infant age group. This approach, however, carries significant incidence of restenosis. The transpalatal correction of choanal atresia has been the definitive approach in older children and adults. We are introducing a new procedure for correction of choanal atresia or stenosis that can be used at any age. The sublabial transseptal repair was performed in four infants without complications or restenosis. Two of our patients previously underwent different types of repair with persistent choanal stenosis. The sublabial transseptal approach provides wide exposure to the nasal cavity and the floor leading to the choanae. The operating microscope and various otologic micro-instruments were used in the surgical dissection. Preservation of the anterior inferior cartilaginous septum and the maxillary crest and spine is mandatory in order not to disturb the nasal growth pattern of the nose and premaxilla. The infants were evaluated with a computed tomography (CT) scan, preoperatively. The posterior inferior portion of the vomer is uniformly wide, increasing the degree of stenosis or atresia. Removal of the vomer is an essential part of this procedure in order to open and enlarge the choanae. Both choanae were stented with polyvinyl tubes. Every attempt was made to keep the stents in position for a minimum of 8 to 10 weeks. Follow-up has been for 2 to 4 years, and no recurrent choanal stenosis has been experienced.

Choanal Atresia↗
PubMed1986

Metabolic interactions of phencyclidine (PCP) and delta 9-tetrahydrocannabinol (THC) in the rat.

The in vitro effects of THC on the metabolism of PCP by rat liver were determined. Samples containing 1 mM PCP were incubated for 1 hr at 37 degrees C with an NADPH-generating system containing 10,000 X g supernatant or Ca++-precipitated rat liver microsomes. These incubations were carried out in the presence or absence of THC and at the end of 1 hr, PCP metabolites were determined by gas chromatography. In the presence of 0.1, 0.05, 0.025 and 0.0125 mM THC, the production of 1-(1-phenyl-4-hydroxycyclohexyl)piperidine (metabolite I) by the 10,000 X g supernatant was decreased by 46, 29, 23 and 16% respectively. Similarly, production of 1-(1-phenylcyclohexyl)-4-hydroxypiperidine (metabolite II) was reduced significantly by 58, 44, 34 and 23% with the respective concentrations of THC. However, the production of 1-phenylcyclohexylamine (metabolite III) was increased by 18, 32, 30 and 22% with 0.1, 0.05, 0.025 and 0.0125 mM THC. Incubations with Ca++-precipitated liver microsomes revealed similar trends in PCP metabolism in the presence or absence of THC. Metabolites I and II were reduced by 62 and 67% by 0.1 mM THC. Another concentration of THC (0.025 mM) caused a 50 and 62% decrease in I and II. These observations suggest that THC alters the in vitro microsomal metabolism of PCP.

Animals↗