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Biomedical subjects

A Shaheen

Publications and source records attributed to A Shaheen.

14 recordsLinked to original sources

Cytoplasmic colloid inclusions in thyroid lesions: a cytomorphological study based on fine needle aspiration.

INTRODUCTION: Intracytoplasmic lumens (ICL) with or without magenta material and transgressing vessels are features of Hürthle cell neoplasms (HCN). After detection of intracytoplasmic colloid inclusions (CIs) including targetoid (magenta) body-like structures in the Hürthle cells (HC) in a case of Hashimoto's thyroiditis (HT), we reviewed cases of HT, thyroid neoplasms, hyperplastic nodules (HN) and colloid goitres to determine the frequency of these structures. Further, an attempt was made to find out the significance of CIs. METHODS: FNA smears of 120 HT, 101 colloid goitres, 11 HN, and 76 neoplastic goitres were examined. The presence of CIs and empty ICL were noted in epithelial cells in these lesions. An attempt was made to find out the difference between HT with and without CIs in respect of various cytomorphologic features. The groups were compared using the Fisher's exact test of probability. RESULTS: The CIs were present in 36 (30.0%) of HT, 26 (34.2%) of neoplastic goitres, 3 (27.3%) of HN, and 4 (4.0%) colloid goitres. As compared to colloid goitres, CIs were present in a significant higher number of cases in HN (P = 0.0202), neoplastic goitres (P < 0.0001), and HT (P < 0.0001). Among neoplasms the frequency of CIs in HCN (75.0%) was significantly higher than that of papillary thyroid carcinoma (PTC) (33.3%, P = 0.0466), and follicular neoplasm (14.3%, P = 0.0083). The CIs were more frequent in HC in HT and HCN but in follicular cells (FC) in other lesions. The HT cases with CIs differed significantly from those without CIs in respect of HC and their cellularity, cellularity of reactive lymphoid cells, extracellular colloid and empty ICL. CONCLUSION: Care should be taken not to diagnose HT cases with an excessive Hürthle cell component and CIs, and PTC cases with Hürthlization and CIs, as HCN in FNA smears. Based on review of the literature and our findings, it is suggested that the Hürthle cell metaplasia in HT is a survival response of FC and the presence of CIs in Hürthle cell may represent their limited ability to synthesize colloid.

Adolescent↗

Feasibility of open simple prostatectomy with early vascular control.

OBJECTIVE: To determine the feasibility of open simple prostatectomy with early vascular control in the treatment of benign prostate hyperplasia (BPH), and thus reduce blood loss. PATIENTS AND METHODS: Thirty-seven patients were reviewed from 1991 to 2002; 34 had a Millin's and three a Freyer's prostatectomy performed by one surgeon, with early vascular control. RESULTS: The mean operative duration was 1.3 h and the mean blood loss 841 mL, with a mean decrease in haemoglobin level of 22 g/L. Six (16%) of the patients received a blood transfusion. The mean weight of the prostate removed was 97.8 g; the duration of catheterization and the hospital stay after surgery were 6.21 and 11.7 days, respectively. There was one (3%) death and one case of pulmonary embolism. Three patients (8%) developed stress incontinence. Two failed to void after surgery and one developed acute retention 3 years later. Five patients developed recurrent obstructive symptoms. CONCLUSION: Open simple prostatectomy with early vascular control reduces the amount of blood loss, rendering it a safe option for treating BPH.

Aged↗

High affinity binding between lipoprotein lipase and lipoproteins involves multiple ionic and hydrophobic interactions, does not require enzyme activity, and is modulated by glycosaminoglycans.

Lipoprotein lipase (LPL) physically associates with lipoproteins and hydrolyzes triglycerides. To characterize the binding of LPL to lipoproteins, we studied the binding of low density lipoproteins (LDL), apolipoprotein (apo) B17, and various apoB-FLAG (DYKDDDDK octapeptide) chimeras to purified LPL. LDL bound to LPL with high affinity (K(d) values of 10(-12) m) similar to that observed for the binding of LDL to its receptors and 1D1, a monoclonal antibody to LDL, and was greater than its affinity for microsomal triglyceride transfer protein. LDL-LPL binding was sensitive to both salt and detergents, indicating the involvement of both hydrophobic and hydrophilic interactions. In contrast, the N-terminal 17% of apoB interacted with LPL mainly via ionic interactions. Binding of various apoB fusion peptides suggested that LPL bound to apoB at multiple sites within apoB17. Tetrahydrolipstatin, a potent enzyme activity inhibitor, had no effect on apoB-LPL binding, indicating that the enzyme activity was not required for apoB binding. LDL-LPL binding was inhibited by monoclonal antibodies that recognize amino acids 380-410 in the C-terminal region of LPL, a region also shown to interact with heparin and LDL receptor-related protein. The LDL-LPL binding was also inhibited by glycosaminoglycans (GAGs); heparin inhibited the interactions by approximately 50% and removal of trace amounts of heparin from LPL preparations increased LDL binding. Thus, we conclude that the high affinity binding between LPL and lipoproteins involves multiple ionic and hydrophobic interactions, does not require enzyme activity and is modulated by GAGs. It is proposed that LPL contains a surface exposed positively charged amino acid cluster that may be important for various physiological interactions of LPL with different biologically important molecules. Moreover, we postulate that by binding to this cluster, GAGs modulate the association between LDL and LPL and the in vivo metabolism of LPL.

Animals↗

Zoosporulation of a new Perkinsus species isolated from the gills of the softshell clam Mya arenaria.

A gill-associated Perkinsus sp. isolated from the softshell clam (Mya arenaria) is described as a new species, P. chesapeaki sp. nov. Examination of the parasite in seawater cultures revealed life cycle stages and zoosporulation processes similar to those described for other species of the genus Perkinsus. Prezoosporangia developed thickened cell walls upon contraction of the cytoplasm and development of a distinctive clear area between the cell wall and the protoplast. Successive bipartition of the protoplast led to the formation of hundred's of zoospores within mature sporangia. Zoospores were released into seawater through one or more discharge tubes. Ultrastructural studies revealed an oblong zoospore possessing two flagella that arose from a concave side located in the upper third of the zoospore body. The anterior flagellum possessed a unilateral array of hair-like structures. A large anterior vacuole and basolateral nucleus dominated the cytoplasm of the zoospore body. The presence of a rudimentary apical complex including an open-sided conoid, rhoptries, micronemes, and subpellicular microtubules were also discerned. Differences in zoospore morphology, and sequence analyses of two genes previously reported, support the designation of the gill-associated Perkinsus from the softshell clam as a new species.

Animals↗

Cost-effectiveness and cost-benefit analysis of using methotrexate vs Goeckerman therapy for psoriasis. A pilot study.

OBJECTIVE: To analyze the net benefit and cost-effectiveness of methotrexate use and Goeckerman therapy for psoriasis. DESIGN: Net benefit and cost-effectiveness depend on the costs, efficacy, and utilities of therapy. Utilities are quantitative measures of patient preferences. We obtained costs by using resource-based accounting techniques. Efficacy was estimated from literature reports. We surveyed patients with psoriasis, dermatologists, and healthy subjects using utility assessment methods. All assumptions were examined in a sensitivity analysis. MAIN OUTCOME MEASURES: For net benefit, if benefits out-weighed the costs, it was deemed worth providing. For the cost-effectiveness analysis, the ratio of costs-to-effectiveness of less than $35,000 was considered cost-effective. RESULTS: Using utilities from healthy nonexperts, the costs of both therapies exceeded the benefits in mild and moderate psoriasis. In severe psoriasis, only methotrexate demonstrates a net benefit. Both therapies were cost-effective compared with no therapy. Liquid methotrexate should be chosen over the tablet form since it was cheaper and had the same outcome. Goeckerman was cost-effective against liquid methotrexate in severe, but not mild or moderate psoriasis. There was a trend for therapies to be more cost-effective when using patient utilities and less with dermatologist utilities. The results were highly sensitive to efficacy and utilities. CONCLUSIONS: The results of this study need to be confirmed in other settings, but they demonstrate that the tools of cost-effectiveness and cost-benefit analysis have great potential value in dermatology. Once efficacy is better characterized and utilities better quantified, these types of analyses will be crucial for health care policy.

Cost-Benefit Analysis↗

Pharmacokinetics and pharmacodynamics of sibrafiban (Ro 48-3657), an orally active IIb/IIIa antagonist, administered alone or in combination with heparin, aspirin, and recombinant tissue-type plasminogen activator in beagles.

This study characterized the pharmacokinetics (PK) and pharmacodynamics (PD) of sibrafiban (Ro 48-3657) in the presence of aspirin, heparin, and recombinant tissue-type plasminogen activator (rt-PA) in beagles. Sibrafiban is a double prodrug that undergoes bioconversion to the inactive prodrug Ro 48-3656 and to the active IIb/IIIa antagonist, Ro 44-3888, after oral administration. After oral sibrafiban, peak Ro 48-3656 plasma concentrations were observed earlier than Ro 44-3888 and were five- to sixfold higher than Ro 44-3888 peak concentrations. Administration of sibrafiban with heparin and aspirin or heparin and rt-PA did not alter sibrafiban PK. Ro 48-3656 and Ro 44-3888 PK and inhibition of platelet-aggregation profiles in groups treated with sibrafiban and heparin/aspirin or sibrafiban and heparin/rt-PA were similar to those of the group receiving sibrafiban alone. Sibrafiban resulted in >80% inhibition of adenosine diphosphate (ADP)-mediated platelet aggregation and an approximate sixfold increase in bleeding time (BT) compared with baseline measurements. The BT increase was greater in the sibrafiban, heparin, and rt-PA-treated group, during rt-PA administration, compared with the group treated with sibrafiban alone. The recovery of platelet aggregation may be slower after administration of sibrafiban with heparin and rt-PA. Sibrafiban had no effect on rt-PA PK or heparin PD.

Administration, Oral↗

Effects of hypercholesterolemia on monokine-induced smooth muscle cell proliferation.

Macrophage/smooth muscle cell interactions play a role in atherogenesis and foreign body reactions to biomaterials. This study investigates the effect of a hypercholesterolemic diet on the ability of smooth muscle cells (SMCs) to respond to monokines which are produced in response to hypercholesterolemia, biomaterials or both. Peritoneal macrophages were harvested from rabbits fed either a normal (M phi NL) or a 2% cholesterol/6% peanut oil diet (M phi ATH) (plasma cholesterol 2840 vs 42.3 [p less than 0.005]). The macrophages were then cultured in the presence of either 1) polyglactin 910 (PG910), 2) Dacron, or 3) no biomaterial (control), and the media collected and pooled by week for the smooth muscle cell mitogenesis assays. Rabbit aortic smooth muscle cells were harvested and cultured from the same two groups of rabbits (SMCNL or SMCATH), quiesced in serum free media (48 h) followed by addition of the test media and 3H-TdR. The addition of either biomaterial to M phi NL-conditioned media increased 3H-TdR incorporation in both smooth muscle lines as compared to controls. PG910 resulted in significantly higher 3H-TdR incorporation than Dacron (weeks 3-5, p less than 0.005). The addition of either biomaterial to M phi ATH also increased 3H-TdR incorporation in both smooth muscle cell lines, however, the magnitude of the response was decreased as compared to the M phi NL-conditioned media in both cell lines (p less than 0.001 for either SMC line). In contrast to the M phi NL-conditioned media, the addition of Dacron to M phi ATH resulted in the highest level of 3H-TdR incorporation in both cell lines as compared to the media without biomaterial. The SMCNL had a higher response to both the monokines in conditioned media (2-fold) and to fetal bovine serum (3-fold) than the SMCATH (p less than 0.001). Although there is a generalized decrease in release of mitogens active on SMCs from M phi ATH, the M phi ATH exposed to Dacron release increased amounts of mitogenic factors, most active on the SMCATH cell line. A common mode of failure of small diameter Dacron grafts in man is pseudointimal hyperplasia, and it is inviting to postulate that the Dacron/macrophage/smooth muscle cell interactions in this atherosclerotic group of patients plays a role in the pathogenesis of this lesion.

Animals↗

Rapid progressive glomerulonephritis in patients with familial Mediterranean fever.

Two patients with a long-standing history of familial Mediterranean fever (FMF) presented with gross hematuria, oliguria, and acute renal failure; both required dialysis support. Kidney biopsies from both patients revealed crescentic rapid progressive glomerulonephritis (RPGN) without amyloidosis. One patient recovered renal function with methylprednisolone pulse therapy and cyclophosamide. The second patient did not improve and required regular hemodialysis. He is asymptomatic on colchicine therapy. To our knowledge, these are the first cases documenting the presence of RPGN in patients with FMF.

Adolescent↗

Lymphocytes subpopulation in normal family members of patients with alpha-chain disease.

Normal family members of eight diagnosed patients suffering from alpha-chain disease had been investigated by immunoelectrophoresis for abnormal alpha-chain protein in their serum. The pattern was demonstrated in four families only, of different members, but all are of the first-degree relationship. The aim of the study was to determine any possible hereditary defect of the immune system in such patients, as compared to the immune system of the normal members of the family who had abnormal protein in their serum. It was found that in both patients and normal members, the proportion of circulating B-lymphocytes was much higher than normal, whereas that of T-lymphocytes was lower than normal. Neither could be sensitized to DNCB, and their skin tests to tuberculin were negative. From all these findings, it was concluded that the disease was a B-cell disease of IgA type transmitted by a hereditary factor associated with a low level of cellular immunity. Further studies are required to support this hypothesis.

Adolescent↗

Lymphocyte subpopulation in primary lung cancer.

To determine whether impaired cellular immune responsiveness in lung cancer patients is related to a reduction in the number of T lymphocytes, circulating levels of T-rosette-forming lymphocytes were measured in 48 cases with primary lung cancer and compared to levels in 94 age-matched healthy subjects. The results show that T lymphocytes levels are significantly reduced in lung cancer patients. A possible consequence of reduced numbers of circulating T lymphocytes would be a diminution in tumor-inhibiting (T-cell) influences and a corresponding relative enhancement of blocking (B-cell) influences, a circumstance which would favor tumor proliferation.

Adenocarcinoma↗

The prognostic value of serum innumoglobulin levels in Hodgkin's disease.

Serum immunoglobulin concentrations have been measured in 31 patients with Hodgkin's lymphoma and related to disease activity and clinical stage. The patients with active untreated disease, the mean IgA concentration was significantly above the normal mean level and the mean IgM concentration was normal. No significant correlation was found between high IgA concentrations and liver involvement. There were decreased mean IgA and IgM concentrations during remission. The changes in immunoglobulin concentrations were found to be dependent on the clinical stage. The data suggest that in certain patients with active Hodgkin's lymphoma, the humoral-mediated immunity may be affected in addition to the cellular-mediated immunity.

Adolescent↗

Salivary duct carcinoma of the palate.

Salivary duct carcinoma is a rare high-grade neoplasm that more frequently affects the parotid gland. Though neoplasms of this type are infrequent in minor salivary glands, they are less aggressive and may lead to early diagnosis before distant metastases could occur. Salivary duct carcinoma is also the most frequent epithelial component of carcinosarcoma. The present article reports a case of SDC of the palate in a 26-year-old male and discusses SDC as a malignant epithelial component in carcinosarcoma.

Adenoma↗