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Biomedical subjects

A Haider

Publications and source records attributed to A Haider.

34 records · Page 2Linked to original sources
PubMed1995

The effects of terbium on the accumulation of cisplatin in human ovarian cancer cells.

In this investigation, we report a relationship between the terbium (Tb3+) binding protein and the accumulation of cisplatin in human ovarian cancer cells. The number of Tb3+ binding sites in cisplatin-resistant C13+ cells is significantly greater by 79% than those in cisplatin-sensitive 2008 cells. Exposure to Tb3+ also increased the cellular accumulation of cisplatin. The accumulation of cisplatin as a function of the Tb3+ concentration in the C13+ cells (0.85%/microM Tb3+) was significantly greater than the accumulation of cisplatin in 2008 cells with respect to Tb3+ (0.46%/microM Tb3+). The number of Tb3+ binding sites in revertant RH4 cells was similar to that in 2008 cells. The RH4 cells were less sensitive to the stimulatory effects of Tb3+ than the C13+ cells. Our results show that the Tb3+ binding protein correlates with cisplatin resistance, and the receptor binding of Tb3+ increases the accumulation of cisplatin in cisplatin-resistant cells.

Binding Sites↗
PubMed1995

Post-ischemic hypothermia ameliorates ischemic brain damage but not post-ischemic audiogenic seizures in rats.

AIM: The objective of this study was to describe a pattern of recovery and histological nerve cell loss in Sprague-Dawley rats exposed to severe brain ischemia and to compare it to that of Wistar rats. METHODS: Ether- and ketamine-anesthetized Sprague-Dawley rats were exposed to 3, 5, 6 and 10 min of normothermic severe brain ischemia (4 groups) induced by hypotension and neck compression. In group No. 5, the brain temperature was rapidly lowered, after 10 min of ischemia, to 30 degrees C during 45-50 min of recirculation. Wistar rats (group No. 6) served as controls (10-min normothermic ischemia). RESULTS: In Sprague-Dawley (S-D) rats, post-ischemic audiogenic seizures (PAS) increased with the duration of ischemia and reached 86% (6/7 rats), after 10 min of ischemia. Mortality rate was high (50% = 7/14 rats). No seizure activity was observed after 10 min of ischemia in 6 Wistar (W) rats, and all survived. In the S-D rats, 10 min of ischemia produced histopathological damage in all brain regions examined, except in the thalamus. Damage was less severe in the W rats. Post-ischemic hypothermia ameliorated hippocampal and cortical nerve cell damage, but had no effect on the incidence of PAS activity and mortality. In W rats, hippocampal nerve cell loss was much less severe than in the S-D rats and cortical damage was not observed. CONCLUSION: Sprague-Dawley rats develop post-ischemic audiogenic seizures more frequently than Wistar rats and mortality rate is high. The incidence of post-ischemic audiogenic seizures and mortality correlates well with the duration of ischemia. Post-ischemic moderate hypothermia (30 degrees C) significantly ameliorated the hippocampal and cortical nerve cell losses after 10 min of severe brain ischemia, but did not improve outcome. It appears that the high mortality rate of S-D rats following brain ischemia is related to frequent post-ischemic audiogenic seizures.

Acoustic Stimulation↗
PubMed1994

Fine-needle aspiration biopsy diagnosis of extrarenal malignant rhabdoid tumor.

Two cases of extrarenal malignant rhabdoid tumors are presented in which diagnosis was suggested by fine-needle aspiration biopsy and confirmed by histologic and electron microscopic examination. Fine-needle aspiration smears in both cases revealed round to polygonal cells with vesicular nuclei and prominent nucleoli. Several tumor cells contained cytoplasmic inclusions composed of intermediate filaments. A majority of the tumor cells stained strongly for vimentin and cytokeratin. Electron microscopic examination revealed many cells with large aggregates of intermediate filaments corresponding to the cytoplasmic inclusions. Fine-needle aspiration biopsy may be used for diagnosing malignant rhabdoid tumor. The diagnosis may be further confirmed by immunohistochemistry and electron microscopy.

Abdominal Neoplasms↗
PubMed1994

Neuroschistosomiasis myelopathy: case report.

A case of intramedullary neuroschistosomal granuloma in a 15-year-old girl is reported. Despite the fact that Saudi Arabia is endemic for schistosomiasis, neuroschistosomiasis has rarely been reported from that country. A review of the literature on the incidence, pathogenesis, clinical patterns and management of neuroschistosomiasis, particularly myelopathy, is given.

Adolescent↗
PubMed1994

Enzymatic determination of sodium, potassium, and chloride in abnormal (hemolyzed, icteric, lipemic, paraproteinemic, or uremic) serum samples compared with indirect determination with ion-selective electrodes.

We evaluated the effect of hemolysis, icteric discoloration, lipemia, paraproteinemia, and uremia on enzymatic methods for determining sodium, potassium, and chloride, according to the National Committee for Clinical Laboratory Standards EP7-P proposals for testing interference from endogenous substances. The sodium, potassium, and chloride assays (reagent kits supplied by Boehringer Mannheim) were based on electrolyte-dependent beta-galactosidase, pyruvate kinase, and alpha-amylase, respectively. The results were compared with those obtained by indirect ion-selective electrodes (ISE), which in turn had been validated by flame photometry. We analyzed the samples with Hitachi 717, 737, and 911 chemistry analyzers and with an IL943 flame photometer. The enzymatic results were in good agreement with those by ISE, the interference-related differences generally being without clinical significance; however, none of the enzymatic methods could analyze grossly lipemic samples.

Bilirubin↗
PubMed1993

Gonadotropin-releasing hormone agonists in the treatment of girls with central precocious puberty.

The onset of puberty before the age of 8 years in a girl is considered precocious. A child who presents with premature sexual development requires a thorough history, physical examination, and appropriate laboratory evaluation. Making the correct diagnosis is crucial to the selection of the appropriate form of therapy and management. Generally, CPP is the result of premature activation of the hypothalamic-pituitary-gonadal axis and can be successfully managed with long-acting GnRH agonists. In addition, GnRH analogue therapy has been shown to be safe, effective, and reversible. Treatment has resulted in a delay in the progression of secondary sexual development, normalization of the growth velocity, slowing of the rate of bone maturation, and an increase in the predicted final adult height. The GnRH agonists are ineffective in the therapy of gonadotropin-independent precocious puberty.

Child↗
PubMed1993

Use of serotonergic drugs for treating depression in older patients.

The selective serotonin reuptake inhibitors (SSRIs) offer a relatively new alternative to traditional tricyclic antidepressants (TCAs) in the treatment of depression in older adults. The two drug classes are equally effective, but SSRIs tend to cause fewer sedating, anticholinergic, or hypotensive effects and are unlikely to affect cardiac conduction. SSRIs also have a wider therapeutic window and are safer in cases of overdose. Potential side effects include GI distress, worsening of headaches, insomnia, and sexual dysfunction. Drawbacks of using SSRIs are their potential for drug interactions and relatively high cost.

Aged↗
PubMed1992

Fine-needle aspiration biopsy of Ki-1-positive anaplastic large-cell lymphoma.

Five cases of Ki-1-positive anaplastic large-cell lymphoma diagnosed by fine-needle aspiration biopsy are reviewed, and cytologic, histologic, and ultrastructural findings in these cases are correlated. In all cases, the diagnosis of anaplastic large-cell lymphoma was suggested on the basis of the morphological appearance in aspiration smears. This diagnosis was confirmed by immunohistochemistry, which revealed strong positivity of most of the cells by Ki-1 antibody. Two of the lymphomas were T-cell type, one was B-cell type, and the remaining 2 were composed of null cells. In 2 cases, intracytoplasmic inclusions were seen in some of the tumor cells in aspiration smears. These were ultrastructurally correlated with large lysosomal bodies of variable morphology. Fine-needle aspiration combined with immunohistochemistry may be an effective technique for diagnosing this neoplasm.

Adolescent↗
PubMed1992

Congenital muscular dystrophy with abnormal radiographic myelin pattern.

We report 11 children with a homogeneous clinical syndrome affecting both sexes, characterized by weakness at birth, slowly improving course, weakness of all muscle groups, arreflexia, elevated blood creatine kinase, normal nerve conduction velocity, dystrophic changes on muscle biopsy, and diffuse periventricular cortical white-matter abnormalities with sparing of corpus callosum, internal capsule, and brain stem. We compare them to 48 other previously reported similar cases and designate them as altered myelin radiographic pattern congenital muscular dystrophy (CMD), which is the same as occidental CMD. We compare them to the other presently accepted phenotypes: progressive Fukuyama CMD, Walker-Warburg or cerebral-ocular CMD, and Santavuori or muscle-eye-brain CMD. We suggest that the different phenotypes are alleles of the same gene, which regulates or expresses a structural protein required for muscle integrity, myelination, and formation of the cortex. Such phenotypic diversity has been established for mutations of Xp21 in X-linked muscular dystrophies.

Biopsy↗
PubMed1990

Infantile CNS spongy degeneration--14 cases: clinical update.

We studied 14 Arab infants with infantile spongy degeneration, 13 of whom were products of consanguineous marriages. They presented in infancy with macrocephaly, poor visual behavior or blindness, and axial hypotonia with appendicular spasticity. Brain CT and MRI showed diffuse symmetric leukoencephalopathy, even before neurologic symptoms. There were relatively normal EEGs. The visual evoked responses (P100) were either absent or delayed early in the course. The brainstem auditory evoked responses showed milder abnormalities, with loss of later components before the earlier ones. Deficient aspartoacylase activity in cultured fibroblasts or brain biopsy confirmed the diagnosis in all patients.

Amidohydrolases↗
PubMed1988

Glanzmann's disease.

Explore the source record for details and available documents.

Blood Platelet Disorders↗
PubMed1988

Negative correlations between parenchymal amyloid and vascular amyloid in hippocampus.

Congo red was used to stain amyloid in 29 blocks of hippocampus from 17 unselected cases of Alzheimer's disease. Green birefringence under polarized light was used for evaluation of the average number of senile plaques and cross-sectional vessel profiles containing amyloid in five fields per slide, at a magnification of X100. Fields were selected that had large numbers of neurofibrillary tangles, also counted on the basis of green birefringence. The vascular involvement by amyloid was expressed as the ratio of amyloid positive to amyloid negative profiles. A negative correlation was found between Congophilic plaques or tangles on the one hand and vascular amyloid content on the other. In other words, cases with large numbers of Congophilic plaques had fewer Congophilic vessels, and vice versa: congophilic plaques = -3 (vessel amyloid) + 2.2, Spearman correlation coefficient, -0.61, P less than 0.01; tangles = -3.7 (vessel amyloid) + 15.6, Spearman correlation coefficient, -0.05, P greater than 0.05. When the slides were reexamined, using only fields with at least one Congophilic vessel, the negative correlation for plaque versus vessel amyloid remained highly significant, whereas that for tangles versus vessel amyloid became highly significant: Congophilic plaques = -1.2 (vessel amyloid) + 2.3, Spearman correlation coefficient, -0.48, P less than 0.01; tangles = -5 (vessel amyloid) + 19, Spearman correlation coefficient, -0.48, P less than 0.01. These data are most compatible with the hypothesis that amyloid is first produced in the parenchyma and is somehow cleared by the vessels. It is least compatible with the hypothesis that the amyloid precursor protein first enters the vessel wall to produce amyloid there, and then moves into the brain to produce amyloid in parenchymal sites.

Aged↗
PubMedDate not supplied

Inhibition of secondary caries lesion progression using fluoride varnish.

The purpose of this study was to determine the efficacy of fluoride varnish (FV) in inhibiting progression of secondary caries (SC). In a first experiment, human teeth, restored either with amalgam or resin composite, were exposed for 4 days to a microbial caries model. Half of each specimen was then painted with an acid-resistant nail varnish to maintain the baseline SC lesion. Specimens were then either treated with a FV (removed after 24 h) or not treated (control groups) prior to being exposed for 4 more days to the caries model. A second experiment was conducted to compare the effect that the varnish (with and without fluoride) had on SC development around amalgam. Confocal laser scanning microscopy data from these experiments suggested that the application of a FV to early, active SC lesions significantly slowed down their progression. Furthermore, the application of a placebo varnish showed a trend towards slowing down lesion progression, suggesting that the effect of FV on SC is not only due to its fluoride release.

Bacteria↗
PubMedDate not supplied

Multiple endocrine neoplasia type iia: report of a family with a study of three generations in qatar.

OBJECTIVE: To study the pattern of multiple endocrine neoplasia type IIA (MEN IIA) and describe the clinical features and results of genetic testing and treatment in 21 members of the first reported family with MEN IIA in Qatar. METHODS: After identification of the proband, we screened all her family members (21 members) with genetic testing for the RET proto-oncogene mutation. Those subjects with the mutation were further assessed for pheochromocytoma by measurement of the 24-hour urinary vanillylmandelic acid, metanephrines, and catecholamines, and those with high levels underwent a metaiodobenzylguanidine scan and adrenalectomy. The serum calcium was measured in a effort to detect hyperparathyroidism. Those family members who had the mutation and were eligible for surgical treatment underwent total thyroidectomy and central compartment dissection. In those patients with high postoperative calcitonin levels, residual disease was sought with radiologic imaging, and follow-up was done with pentagastrin stimulation tests. RESULTS: Of the 21 family members screened, 10 had the RET proto-oncogene mutation (codon 634, TGC->GGC) (5 females and 5 males; 6 adults and 4 children). All the adults had bilateral medullary thyroid carcinoma (MTC); four of them had lymph node metastatic lesions, and one had metastatic involvement of the liver. Two adults had pheochromocytomas. Two family members were reported to have parathyroid hyperplasia, although both were normocalcemic. CONCLUSION: This family with MEN IIA showed classic mendelian autosomal dominant inheritance. All adult patients had MTC, two had pheochromocytomas, and two had parathyroid hyperplasia. Although one child had a high stimulated calcitonin level, the histopathologic findings were normal; another child with high stimulated calcitonin levels showed C-cell hyperplasia on histopathologic examination.

Adrenal Gland Neoplasms↗