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Biomedical subjects

A N Manepalli

Publications and source records attributed to A N Manepalli.

13 recordsLinked to original sources
PubMed2001

Solitary intramedullary neurosarcoidosis: role of MRI in early detection.

BACKGROUND: Intramedullary neurosarcoidosis may be the first manifestation of the disease and may mimic a tumor clinically and radiographically. Two patients who presented with cervical intramedullary lesions on magnetic resonance imaging (MRI) scans were found to have neurosarcoidosis. CLINICAL PRESENTATION: Two patients with negative past medical history presented with progressive myelopathic features, and intramedullary cervical lesions were detected on MRI scan; the diagnosis was made on biopsy of the lesions. Early therapeutic intervention led to a favorable outcome. CONCLUSION: Intra-medullary neurosarcoidosis, especially in the cervical cord, can be the initial presentation of the disease, mimicking a tumor. MRI scan, biopsy, and, in fewer cases, angiotensin-converting enzyme levels can help with the diagnosis and may lead to a favorable outcome.

Cervical Vertebrae↗
PubMed1999

Transcriptional expression of tissue factor pathway inhibitor, thrombomodulin and von Willebrand factor in normal human tissues.

Under normal physiologic conditions, tissue factor pathway inhibitor (TFPI) is synthesized primarily by the microvascular endothelium. Using Northern blotting, we studied its transcriptional expression in different organs and compared it with the expression of two other endothelial specific proteins, namely thrombomodulin (TM) and von Willebrand factor (vWF). The order of mRNA expression for each protein was: TFPI-placenta>lung>liver>kidney>heart>skeletal muscle> or =pancreas>brain; TM-heart>pancreas>lung>skeletal muscle>kidney> or =liver>placenta>brain; and vWF-heart>skeletal muscle>pancreas>lung> or =kidney>placenta>brain>liver. Notably, heart expressed TM and vWF mRNA in large amounts and only small amounts of TFPI whereas lung expressed all three mRNAs in significant amounts. Placenta, on the contrary, expressed large amounts of TFPI but only small amounts of TM and vWF mRNAs. Brain by this technique was found to express undetectable amounts of TFPI and TM mRNAs but small amounts of vWF mRNA. The expression of TFPI mRNA in the brain was however detected by RT/PCR and the antigen was localized to the endothelium of microvessels as well as to the astrocytes and oligodendrocytes. Since ultimate expression of proteins is linked to the expression of their mRNAs, our data support a concept that vascular endothelium is made up of phenotypically diverse groups of cells and that endothelial cells of different vascular beds express specific sets of genes that enable them to carry out tissue-specific functions. Importantly, since astrocytes are known to express tissue factor, the TFPI expression by these cells may control coagulation in their microenvironment and their response to injury and inflammation.

Brain↗
PubMed1998

Kappa-opioid receptor binding varies inversely with tumor grade in human gliomas.

BACKGROUND: Opioid agonists can inhibit cell proliferation in various neural tumor cell lines, including rat gliomas. Because opioid antimitogenic effects are mediated by opioid receptors, it was of interest to the authors to determine opioid receptor levels in human brain tumors. METHODS: Specimens obtained at craniotomy from 30 patients with glioma and nonneoplastic brain disorders were evaluated for their kappa-opioid receptor binding. Kd and Bmax values were estimated from homologous competition binding curves with the kappa1-selective radioligand [3H]U69,593. RESULTS: Receptor binding density was greatest in nonneoplastic brain tissue, less in Grade 2 and 3 astrocytoma, and least in glioblastoma multiforme. CONCLUSIONS: These results suggest that opioid receptor-based stratification of grade may have clinical utility in distinguishing glioblastoma multiforme from lower grade astrocytomas, and thereby may facilitate diagnosis and treatment.

Astrocytoma↗
PubMed1998

Disseminated histoplasmosis and Wegener's granulomatosis.

Disseminated histoplasmosis is an unusual complication in endemic areas and has been reported in patients with an immunodeficient state, either from human immunodeficiency virus (HIV) infection or transplantation. In the non-HIV population, rare cases of disseminated histoplasmosis have been reported in patients with leukemia and Hodgkin's disease and patients receiving steroid therapy for various diseases. We report a case of disseminated histoplasmosis in a patient with Wegener's granulomatosis.

Adult↗
PubMed1998

Cranial vault expansion using transcutaneously activated magnetic implants.

The technique of distraction osteogenesis has not been widely used in the treatment of problems of the head and face because of the need for external fixators. By using magnetic, rather than mechanical, forces to drive bone movement we hope to expand the applications of the technique to include the treatment of cranial vault deformities. Thirty immature rabbits were studied. Twenty-six of the rabbits underwent operations. Each of the 26 had 2 magnets fixed to its skull: one on the left parietal bone and one on the right parietal bone. Incomplete circumferential osteotomies were then performed around each magnet on 13 of the rabbits. A head frame was attached to each animal. Head frames without magnets were placed on 6 of the rabbits (3 with osteotomy, 3 without osteotomy) while 20 of the animals (10 with osteotomy, 10 without osteotomy) had 2 magnets mounted on the frames which were of opposite polarity to those implanted. The remaining 4 rabbits served as nonoperative controls. Six weeks later all of the animals were sacrificed. There were significant differences in the cranial volumes and contours between the groups of animals. Many of the differences were increased by coincident osteotomy. Associated histologic findings are described.

Animals↗
PubMed1996

Epidural hematoma producing Brown-Séquard syndrome: a case due to ruptured hemangioma with magnetic resonance imaging findings.

A man developed spontaneous spinal epidural hematoma secondary to ruptured hemangioma with a clinical picture resembling acute partial Brown-Séquard syndrome. Diagnosis by magnetic resonance imaging (MRI) allowed prompt surgical decompression and complete reversal of the neurological deficits. The diagnosis, etiology, and MRI findings of spinal epidural hematomas are discussed.

Adult↗
PubMed1991

Fast feedback regulation of ACTH by cortisol.

1. Fast feedback regulation of ACTH by cortisol has not been well studied in humans. The authors studied the existence and characteristics of fast feedback regulation in normal humans. 2. Hydrocortisone hemisuccinate was infused at two different rates: 6 mg/hour and 12 mg/hour for two hours. 3. The studies did not demonstrate the existence of fast feedback regulation of basal ACTH concentration by cortisol in man. Further, the response was variable and the rate sensitive character was difficult to demonstrate.

Adrenocorticotropic Hormone↗
PubMed1988

Growth hormone response to growth hormone-releasing factor in depression.

A blunted growth hormone (GH) response to clonidine and other pharmacologic stimuli has been reported in patients with depression. This blunted growth hormone response to clonidine has led to the speculation that there is a central alpha-2 adrenergic receptor subsensitivity in depression. This hypothesis is based on the assumption that the pituitary somatotroph response to growth hormone-releasing factor (GHRF) is not altered in depression. In the present preliminary study, the somatotroph response to GHRF in depressed patients and normal controls has been evaluated in four depressed patients and four age- and sex-matched controls. The GH response to GRF is highly variable both in normal individuals and in the depressed patients studied. Larger numbers of patients and controls must be studied before any definitive conclusions can be drawn about GH responses to GRF in depressed patients.

Depressive Disorder↗
PubMed1988

Growth hormone-releasing factor stimulation test in depression.

The authors administered the growth hormone-releasing factor (GRF) stimulation test to 19 patients with major depression and 19 age- and sex-matched control subjects to test the hypothesis that a blunted growth hormone (GH) response to clonidine reflects a central alpha 2-adrenergic receptor subsensitivity in depression. GH response to GRF was significantly higher in patients with depression than in control subjects. This group difference was mainly attributable to three of the 19 depressed patients who exhibited markedly high GH responses to GRF. These results suggest that the blunted GH response to clonidine seen in patients with depression is not due to a pituitary defect in GH secretion.

Adult↗
PubMed1988

Circadian rhythm of adrenergic regulation of adrenocorticotropin and cortisol secretion in man.

The effects of the alpha-adrenergic agonist methoxamine on the human hypothalamic-pituitary-adrenal axis was assessed by a placebo-controlled study in the morning and one in the evening. A 5-mg iv bolus dose of methoxamine in normal subjects caused a significant rise in plasma ACTH and cortisol concentrations in the morning study. However, no significant change in plasma cortisol or ACTH concentrations was noted during the evening study. These studies suggest the existence of a diurnal variation in alpha 1-adrenergic regulation of the hypothalamic-pituitary-adrenal axis.

Adrenocorticotropic Hormone↗
PubMed1985

What does the dexamethasone suppression test identify?

The authors studied the Dexamethasone Suppression Test (DST) in chronic pain patients with and without major depression, using items from a modified version of the Hamilton Depression Scale, the Hamilton Anxiety Scale, and the Montgomery-Asberg Depression Rating Scale. The purpose of the study was to identify the factor or factors which discriminated DST suppressors from nonsuppressors. The data suggest that depression and its profile are efficient discriminators of suppressors and nonsuppressors. Anxiety-related items were not as good as discriminators. The items that identified nonsuppression were the items that are often seen in combination in endogenous depression.

Adult↗