The delineation of a decapeptide gonadotropin-releasing sequence in the carboxyl-terminal extension of the human gonadotropin-releasing hormone precursor.

The human gonadotropin-releasing hormone (GnRH) precursor consists of the GnRH sequence followed by a 59-amino acid carboxyl-terminal extension. A 56-amino acid peptide within this extension has been shown to stimulate gonadotropin release, and this activity has been localized to its amino-terminal region. A series of seven overlapping peptide fragments corresponding to the first 24 amino acids of the carboxyl-extension of the GnRH precursor were synthesized and tested for their ability to stimulate luteinizing hormone and follicle-stimulating hormone release from cultured human anterior pituitary cells.

Relationship between measles, malnutrition, and blindness: a prospective study in Indian children.

A prospective study was conducted in slum children to determine the incidence of post-measles corneal disease and to clarify its relationship with nutritional status. A total of 318 cases of measles were identified over a period of 15 mo; maximum incidence was observed for children between 1-2 yr. Most of the children showed weight loss and serum proteins decrease during the acute stage of measles.

Receptor binding and gonadotropin-releasing activity of a novel chicken gonadotropin-releasing hormone ([His5, Trp7, Tyr8]GnRH) and a D-Arg6 analog.

Receptor binding and gonadotropin-releasing activity was compared for mammalian GnRH, [Gln8]GnRH (chicken I GnRH), [His5, Trp7, Tyr8]GnRH (chicken II GnRH), [Trp7, Leu8]GnRH (salmon GnRH), and [D-Arg6] chicken II GnRH. The mean ED50 values for mammalian GnRH, chicken I GnRH, chicken II GnRH, and salmon GnRH in stimulating LH release from dispersed chicken pituitary cells were 0.27 nM, 0.

Stimulation of gonadotropin release by a non-GnRH peptide sequence of the GnRH precursor.

The human gonadotropin-releasing hormone (GnRH) precursor comprises the GnRH sequence followed by an extension of 59 amino acids. Basic amino acid residues in the carboxyl terminal extension may represent sites of processing to biologically active peptides. A synthetic peptide comprising the first 13 amino acids (H X Asp-Ala-Glu-Asn-Leu-Ile-Asp-Ser-Phe-Gln-Glu-Ile-Val X OH) of the 59-amino acid peptide was found to stimulate the release of gonadotropic hormones from human and baboon anterior pituitary cells in culture.

Effect of luteinising hormone releasing hormone and its analogues on plasma luteinising hormone concentrations in incubating bantam hens.

The ability of synthetic vertebrate luteinising hormone releasing hormones (LHRHs) and their long-acting analogues to maintain elevated plasma luteinising hormone (LH) concentrations and to stimulate ovarian growth was investigated in incubating bantam hens. Chicken LHRH-II (pGlu1-His2-Trp3-Ser4-His5-Gly6-Trp7-Tyr8-Pro9-G ly10-NH2) was more effective than chicken LHRH-I (pGlu1-His2-Trp3-Ser4-Tyr5-Gly6-Leu7-Gln8-Pro9-Gly10-N H2) or porcine LHRH (pGlu1-His2-Trp3-Ser4-Tyr5-Gly6-Leu7-Arg8-Pro9-Gly10-N H2) in stimulating the release of LH. Long-acting analogues of chicken LHRHs (chLHRHs) were created by substituting D-amino acids in position 6.

Electrical properties of the myotendon region of frog twitch muscle fibers measured in the frequency domain.

The electrical properties of the end of a muscle fiber were determined using three microelectrodes, one passing sinusoidal current, the other two recording the resulting voltages. An electrical model was constructed from the morphology of the fiber, including the resistance of the extracellular space between cells; the parameters of this model were determined by fitting the model to the observed voltage responses. Our results, analyzed directly or by curve fits, show that the end of muscle fibers contains a large capacitance resulting from the extensive membrane folds at the myotendon junction.

Canine bombesin-like gastrin releasing peptides stimulate gastrin release and acid secretion in the dog.

The synthetic mammalian bombesin-like peptides, canine gastrin releasing peptide 27, 23 and 10, and porcine gastrin releasing peptide 27 were compared with amphibian bombesin 14 and 10 during intravenous infusions into six conscious dogs with chronic gastric cannulae. Gastrin and gastrin releasing peptide were measured in peripherally sampled venous blood by radioimmunoassay and gastric acid secretions were collected. All forms of gastrin releasing peptide stimulated gastrin release and gastric acid secretion in a dose-dependent manner.

Muscle fiber termination at the tendon in the frog's sartorius: a stereological study.

The force produced within skeletal muscle fibers is transmitted to the bone via a myotendinous junction. This junctional region was examined by light and electron microscopy in the sartorius muscles of three Rana temporaria. The muscle fibers tapered and inserted at an angle of about 25 degrees with the connective tissue fascia near the bone.

Charge movement in skeletal muscle fibers paralyzed by the calcium-entry blocker D600.

We report measurements of nonlinear charge movement in frog skeletal muscle fibers paralyzed by the calcium-entry blocker [Schwartz, A. & Taira, N., eds.

Further results on a multiple-testing procedure for clinical trials.

O'Brien and Fleming (1979, Biometrics 35, 549-556) proposed a procedure for multiple testing in clinical trials for acute disease. We evaluated their procedure for chronic-disease models and found that it can be used without modification. Type I errors are unaltered and no loss of power is seen in comparison with single-sample procedures.

Paralysis of frog skeletal muscle fibres by the calcium antagonist D-600.

The Ca2+ channel blocker D-600 (methoxyverapamil) paralyses single muscle fibres of the frog: fibres exposed to the drug at 7 degrees C give a single K+ contracture after which they are paralysed, unable to contract in response to electrical stimulation or further applications of K+. Paralysed fibres contract in response to caffeine and have normal resting potentials and action potentials. Fibres treated with D-600 at 22 degrees C are not paralysed.

Prevalence and aetiology of cataract in Punjab.

Three districts in the Punjab plains were surveyed in 1976-7 for senile cataract and potential risk factors. The prevalence of senile cataract was 15.3% among 1269 persons examined who were aged 30 ang older, and 4.

The natural history of gyrate atrophy of the choroid and retina.

Twenty-nine Finnish patients (8-80 years old during follow-up) with hyperornithinemia and gyrate atrophy (HOGA) were followed 2 to 31 years to determine when and how rapidly visual acuities and visual functions were affected by the disease. Considerable variability was observed both in the age at which visual acuities began to decrease and the age at which visual acuities reached 20/200. Acuities in phakic eyes tended to decrease from 20/30 to 20/200 in ten years or less, while aphakic eyes exhibited generally slower loss of vision.

Alternative definitions of open-angle glaucoma. Effect on prevalence and associations in the Framingham eye study.

Framingham Eye Study data were used to examine the effect of alternative definitions of open-angle glaucoma (OAG) on prevalence and on associations with selected variables from the Framingham Heart Study. Definitions were based on various combinations of history of glaucoma, types of visual field defects, and functions of intraocular pressure and cup-disc ratio. Visual field defect irrespective of blind spot enlargement is used as a standard for comparison.

The Framingham Eye Study monograph: An ophthalmological and epidemiological study of cataract, glaucoma, diabetic retinopathy, macular degeneration, and visual acuity in a general population of 2631 adults, 1973-1975.

Ophthalmologic examinations for cataract, glaucoma, diabetic retinopathy, macular degeneration and visual acuity were performed on 2631 of the 3977 members of the Framingham (Massachusetts) Heart Study population still living in 1973-1975. The subjects ranged in age from 52 to 85 years. This monograph presents the detailed protocols and record forms for screening and diagnostic examinations, definitions of the specific abnormalities and characteristics used to screen for each disease, criteria for suspicion and diagnosis of diseases, detailed tables of the basic data from the study, evaluation of quality of the data, and discussion of selected findings.

The Framingham eye study: introduction to the monograph.

This article briefly summarizes the monography, The Framingham Eye Study Monograph: an Ophthalmological and Epidemiological Study of Cataract, Glaucoma, Diabetic Retinopathy, Macular Degeneration, and Visual Acuity in a General Population of 2631 Adults, 1973-1975. This 275-page monograph, authored by H. Liebowitz, D.

Statistical computing in the United States.

Recent history and developments related to the increase in statistical computing activities in the United States and by U.S. participants in international efforts are reviewed, with emphasis on important events, organizations, references, and products which contribute to informed selection and use of statistical programs.

Plasma cofactors of platelet function: correlation with diabetic retinopathy and hemoglobins Ala-c.

We studied 29 diabetic patients (eight without and 21 with retinopathy) and 29 matched control subjects for hemoglobins Ala-c and plasma levels of fibrinogen, von Willebrand factor, and factor VIII/von Willebrand factor antigen. Hemoglobins Ala-c were elevated in all diabetic patients, regardless of retinopathy (P less than 0.001); fibrinogen was elevated only in those with retinopathy (P less than 0.