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Biomedical subjects

P Hwang

Publications and source records attributed to P Hwang.

54 records · Page 3Linked to original sources
PubMed1975

Human and monkey prolactin and growth hormone: separation of polymorphic forms by isoelectric focusing.

The feasibility of using isoelectric focusing for the separation of primate pituitary growth hormone from prolactin and for the characterization of polymorphic forms of these hormones was explored. In a pH 3--10 gradient, extracts of both human and cynomolgus monkey pituitaries were each resolved into 4 growth hormone components and at least 3 prolactin components, as shown by radioimmunoassay. In narrower gradients (of 2--3 pH units) greater resolution was achieved; the principal growth hormone components were well separated from the principal prolactin components but there was overlapping of some minor components. A partially purified human prolactin preparation was found to contain 4 prolactin components, one of which had a prolactin/growth hormone ratio of 760. Clinical grade human growth hormone was also resolved into at least 5 prolactin and 5 growth hormone components, many of which had higher pI values than those found in pituitary extract. Under the conditions used, both growth hormone and prolactin were found to be polymorphic with respect to isoelectric point. Some of the human prolactin components were found to contain less than 0.2% growth hormone by radioimmunoassay. Monkey growth hormone containing 0.01% prolactin was isolated. These findings demonstrate that isoelectric focusing is useful for the preparation of both growth hormone and prolactin which are essentially free of one another. Furthermore, the polymorphic forms were repeatedly found in preparations obtained by several methods and from 2 different species, suggesting that these forms are not artifacts.

Animals↗
PubMed1973

Human prolactin.

Explore the source record for details and available documents.

Age Factors↗
PubMed1972

Functional evaluation of prolactin secretion: a guide to therapy.

Stimulation and inhibition tests are proposed for evaluating prolactin secretion. Thyrotropin-releasing hormone (TRH) stimulates the release of prolactin from the pituitary. Chlorpromazine acts presumably at the hypothalamic level to increase prolactin secretion. L-Dopa (D,L-alpha-hydrazino-alpha-methyl-beta-[3,4-di-hydroxyphenyl]) has the opposite effect; it inhibits prolactin secretion and may be effective in suppressing galactorrhea.

Administration, Oral↗
PubMed1971

A radioimmunoassay for human prolactin.

A radioimmunoassay for primate prolactin has been developed, with [(131)I] monkey prolactin, and antibodies to monkey or human prolactin. The assay is specific for prolactin; human growth hormone, and human and monkey placental lactogen show no significant crossreaction. The assay is sensitive enough to measure prolactin concentrations in the sera of most humans studied. The concentration of prolactin in the serum of normal children and adults of either sex was usually below 30 ng/ml, while very high concentrations (up to 500 ng/ml) were observed in newborn infants. The serum prolactin concentration during the menstrual cycle showed no definite increase in the luteal phase. Of 24 patients with galactorrhea, 20 had prolactin concentrations above 30 ng/ml; the highest value observed was 1500 ng/ml. In contrast, 12 of 13 patients with acromegaly had concentrations within the normal range. During pregnancy, the concentration of prolactin in serum rose progressively from an average of 30 ng/ml in the first trimester to 200 ng/ml at term. Postpartum, prolactin concentrations fell to normal levels after 1-2 weeks. Suckling was a potent stimulus to prolactin release, increasing its concentration in serum some 10- to 20-fold.

Acromegaly↗
PubMedDate not supplied

HPLC determination of benzthiazide in biologic material.

An assay was developed for benzthiazide in plasma, urine and feces, using high performance liquid chromatography (HPLC). A reverse-phase column was employed, with quantitation af 280 nm, using polythiazide as an internal standard. In three of four human subjects who received a 50 mg benzthiazide tablet the plasma concentrations were below the 10 ng ml-1 sensitivity limit of the assay, and the urinary recovery averaged less than one per cent of the dose. One subject received a 50 mg dose as both a tablet and a solution; the urinary recoveries for these two doses were 1.7 and 10.4 per cent, respectively. Fecal samples, obtained from two subjects who received 50 mg tablets, were estimated to contain approximately 80 per cent of the administered dose.

Adult↗
PubMedDate not supplied

Intractable seizure disorder associated with chronic herpes infection. HSV1 detection in tissue by the polymerase chain reaction.

We describe the pathological findings and report the detection of herpes simplex virus 1 (HSV1) in the brain in three patients who presented with intractable seizures. All three patients had a previous history of HSV1 encephalitis and went on to develop a medically refractory seizure disorder necessitating surgical intervention. HSV1 encephalitis was clinically diagnosed and treated at 6 months, 3 years, and 7 months and surgical resection was done at 8.5 years, 6 years, and 3 years, in cases 1, 2 and 3, respectively. Pathological examination revealed chronic encephalitis in all three cases, with microglial nodules, intraparenchymal, perivascular and meningeal lymphocytic infiltrates, and gliosis. While immunohistochemical and ultrastructural studies were negative for viral pathogens, polymerase chain reaction (PCR) analysis revealed HSV1 genome. These cases represent examples of chronic herpes encephalitis and seizure disorder with presence of viral genome in the brain long after the initial episode of treated herpes encephalitis.

Cerebral Cortex↗
PubMedDate not supplied

Unique desmoplastic cerebral tumor in a patient with complex partial seizures.

Primary brain tumors with prominent desmoplasia include the gliofibroma, desmoplastic infantile ganglioglioma (DIG), pleomorphic xanthoastrocytoma (PXA), and desmoplastic cerebral astrocytoma. In the present report, we describe unusual pathological appearances in two successive resections of a left temporal tumor in a patient with complex partial seizures. Both tumors showed focal astroglial and very prominent neuronal differentiation. In the first resection at age 11 years, the tumor showed only focal desmoplastic areas and prominent neuronal differentiation with bizarre atypical giant cells. In the second resection at age 14 years, the morphology was dramatically different. Now the tumor showed marked desmoplasia with tumor cells coexpressing neuronal and glial markers. Electron microscopy showed prominent neuronal differentiation in both resections and presence of basal lamina around tumor cells. Our case represents a unique example of an extraordinary degree of neuronal differentiation in a desmoplastic cerebral tumor. While cellular pleomorphism in a desmoplastic tumor traditionally suggests the diagnosis of PXA, we wish to underscore that many cells exhibiting marked cytologic atypia may in fact be of neuronal rather than of glial origin as in our case.

Adolescent↗
PubMedDate not supplied

Pathology of chronic herpes infection associated with seizure disorder: a report of two cases with tissue detection of herpes simplex virus 1 by the polymerase chain reaction.

Although uncommon, the association of chronic encephalitis with epilepsy is well recognized. While a viral etiology has been suspected based on the morphology, to date no virus has been successfully cultured from the brain in patients with Rasmussen's encephalitis. We describe the pathologic findings and report the detection of herpes simplex virus 1 (HSV1) in the brain in two patients who presented primarily with intractable seizures. In the first patient, an intrauterine infection was suspected as the underlying basis for the seizure disorder and the extensive cerebral calcification and gliosis. The second patient (with presumed HSV1 encephalitis at age 7 months) underwent a temporal lobectomy for medically refractory seizures at the age of 3 years and pathologic examination revealed a chronic encephalitis. While immunohistochemical, ultrastructural, and culture studies were negative for viral pathogens, molecular analysis by the polymerase chain reaction (PCR) revealed HSV1 DNA sequences in both cases. Thus our cases represent two examples of chronic encephalitis associated with a seizure disorder, where a definitive viral etiology was documented by PCR.

Calcinosis↗