bluuebunny/crossref_metadata_2025_split huggingface dataset:
Guanadrel Sulfate: A Postganglionic Sympathetic Inhibitor for the Treatment of Mild to Moderate Hypertension
Authors: Palmer John D. , Nugent Charles A. 
Published: December 2015

Guanadrel sulfate is structurally and pharmacologically similar to guanethidine but has different pharmacokinetic properties. The drug produces peripheral postganglionic sympathetic blockade as a consequence of interference with neuronal release of norepinephrine and displacement of norepinephrine from storage vesicles. Animal studies using large multiples of human antihypertensive doses suggest a low order of human toxicity. Clinical studies have failed to reveal any major effect on hematologic, hepatic or renal function. The effect on serum lipids and plasma renin is unknown. The drug is well absorbed after oral administration. Peak plasma levels in humans occur 1.5–2 hours after a administration. Protein binding is less than 20%. Data from animal studies and clinical trials demonstrating a lack of central nervous system side effects indicate that little if any drug enters the central nervous system. The drug is partially metabolized by the liver, but nearly 50% of an orally administered dose appears unchanged in the urine. The mean elimination half‐life is approximately 12 hours.The onset of antihypertensive action after oral administration of guanadrel to humans is 30–120 minutes (mean 77 minutes). The offset of drug action after a single oral dose ranges between 4–14 hours (mean 9 hours). The hypotensive response to guanadrel in hypertensive subjects is the result of a decline in systemic vascular resistance with an impairment of the normal sympathetic reflexes in the erect position. Guanadrel causes a reduction in renal blood flow and glomerular filtration rate in the erect position. Open label clinical trials of antihypertensive efficacy indicate that guanadrel is effective in 60 and 70% of patients in the supine and erect positions, respectively. In comparative clinical trials, guanadrel appears to be as effective as guanethidine or methyldopa in reducing blood pressure in persons with mild to moderately severe hypertension; mean doses ranged from 56–162 mg/day. In other studies, investigators have used doses of 5–600 mg daily. The maximum recommended dosage is 400 mg/day. Side effects reported with guanadrel administration are those that would be predicted for a postganglionic sympathetic inhibitor that does not enter the central nervous system. Sexual dysfunction, orthostatic dizziness and diarrhea occur with the drug but do not seem to be as frequent or as severe as with guanethidine administration. In a comparison of guanadrel to methyldopa, methyldopa caused more complaints of drowsiness, and drowsiness scores of methyldopa patients remained higher than those of guanadrel patients even after two years of therapy. The drug has received approval as a step 2 antihypertensive agent in the United States. The available data suggest that it will serve as a reasonable alternative to other step 2 antihypertensives.
Evaluation of New Indomethacin Dosage Forms
Authors: Waller Elaine S. 
Published: December 2015

Indomethacin, an indole derivative nonsteroidal anti‐inflammatory drug, has been available since the early 1960s in gelatin capsules. In 1982, a sustained release product, Indocin® SR, was marketed. Awaiting marketing approval is a unique controlled release form of indomethacin, Indos.® The disposition of indomethacin includes enterohepatic cycling and extensive metabolism to inactive metabolites. Enterohepatic cycling makes interpretation of bioavailability estimates of indomethacin dosage forms difficult. The relationship of indomethacin plasma concentrations to therapeutic effects and side effects is inconclusive. It appears in vivo prostaglandin inhibition occurs at very low plasma concentrations that are achievable with all available dosage forms.Indocin® SR is a sustained release capsule of indomethacin designed to deliver 25 mg of drug immediately and 50 mg gradually. Absolute bioavailability of the product is 80%. The plasma concentration‐time curves do not show good sustained release characteristics; after four hours plasma concentrations resemble those seen with a single dose of regular capsules. The cost compared with Indocin® is competitive.Indos® is a zero‐order release form of indomethacin. It is a unique drug delivery system that shows good controlled release characteristics. Bioavailability is 85%.Both Indocin® SR and Indos® are apparently therapeutically equivalent to indomethacin capsules. In elderly patients, Indos® has been shown to be associated with fewer side effects than Indocin®. Both Indocin® SR and Indos® have the advantage of once or twice daily dosing.
Oxprenolol Hydrochloride: Pharmacology, Pharmacokinetics, Adverse Effects and Clinical Efficacy
Authors: Russo Mary E. , Covinsky Joel O. 
Published: December 2015

Oxprenolol is a nonselective beta‐adrenergic blocking agent that also possesses intrinsic sympathomimetic activity (ISA) and membrane stabilizing effects. Oxprenolol undergoes first pass metabolism with only 30% of an oral dose reaching the systemic circulation. The drug is approximately 80% protein bound and is eliminated primarily by glucuronidation in the liver. Less than 4% of oxprenolol is excreted unchanged in the urine. Oxprenolol may reduce the heart rate and prolong the effective and functional atrioventricular nodal refractory period. Oxprenolol has less negative inotropic and chronotropic effects than propranolol, Plasma renin activity is reduced; however, changes in plasma aldosterone level are not significant. Long term metabolic effects require further study.Oxprenolol appears to be comparable to other beta blockers in the treatment of hypertension and angina pectoris with no additional adverse reactions. If its partial agonist effect proves useful, it may have an advantage over other agents in treating patients with borderline cardiac reserve. Because of limited data, the use of oxprenolol for the treatment of arrhythmias, migraine, thyrotoxicosis, anxiety, and glaucoma cannot be recommended at this time.
Effects of Human Chorionic Gonadotropin, Prolactin, and Bromocriptine on Photoperiodinduced Testicular Regression and Recrudescence in Golden Hmsters
Authors: BARTKE A. , HOGAN M. P. , CUTTY C. B. 
Published: December 2015

Exposure of adult male hamsters to short day‐length (short photoperiod) causes atrophy of their reproductive systems. Hamsters were transferred from long to short photoperiod and, starting two months later, injected three times a week for three weeks with saline, 1.25, 5, or 20 IU of human chorionic gonadotropin (hCG). Treatment with 5 or 20 IU hCG resulted in significant increases in the weights of the testes and the seminal vesicles. In another group of animals, identical doses of hCG were injected starting at the time of transfer from long to short photoperiod. After 14 weeks of treatment, testicular weight was significantly greater in animals given 20 IU hCG than In animals injected with saline, although it approximated only 50% of testicular weight In adult males kept in long photoperiod. Since we have previously obtained very similar results using prolactin (PRL) producing ectopic pituitary homografts, it was of interest to examine the interaction of pituitary grafts and hCG. Male hamsters were transferred to a short photoperiod and treated with a transplant of one pituitary from an adult female hamster plus 5 IU hCG three times a week or with hCG alone. After 15 weeks, the weights of the testes and the seminal vesides were significantly greater In grafted hCG‐treated hamsters than in those animals treated with hCG only. Testicular weight in animals given both grafts and hCG corresponded to approximately 75% of testicular weight in long photoperiod controls, while seminal vesicle weights in these two groups did not differ.To examine the role of endogenous PRL in long photoperiod‐induced testicular recrudescence, hamsters which had been exposed to a short photoperiod for two months were returned to a long photoperiod and treated daily with bromocriptlne (Sandoz CB‐154, an inhibitor of PRL release) or with vehicle. After three weeks, the weights of the testes and the seminal vesicles were significantly lower in bromocriptine‐treated than in control hamsters, but after five and a half weeks these differences were no longer evident.We conclude that (1) suppression of the release of both PRL and gonadotropins is responsible for gonadal regression in short photoperiod, and (2) stimulation of PRL secretion contributes to recrudescence of the male reproductive system in long photoperiod.
The Effects of Experimental Cryptorchidism on the Entry of [3H]‐Inulin and [3H]‐Horseradish Peroxidase into the Lumen of the Rat Seminiferous Tubules
Authors: TURNER T. T. , D'ADDARIO D. A. , FORREST J. B. , HOWARDS S. S. 
Published: December 2015

The objective of this research was to determine if experimental cryptorchidism causes significant changes in the rat blood‐testis barrier. Micropuncture of the seminiferous tubules of normal, sham‐operated, or surgicaily‐cryptorchid rats was performed after intravenous infusion of [3H]‐inulin or subtunica injection of [3H]‐horseradish peroxidase. Concentration of the isotopes in the lumen of the seminiferous tubule was determined. Normal, sham, and cryptorchid tissues were also immersed in hypertonic (.75 M) LiCI and prepared for observation by light microscopy.Micropuncture experiments demonstrated that cryptorchidism significantly increased the penetration of the blood testis barrier by [3H]‐inulin and [3H]‐horseradish peroxidase. The LiCI emersion techniques, a histological method of visually detecting the presence of an intact blood‐testis barrier, also demonstrated partial disruption of the blood‐testis barrier in the cryptorchid testis. In spite of these alterations, the seminiferous tubules of the experimentally‐cryptorchid testes retained a large proportion of their capacity to exclude macromolecules.
Endogenous Steroids in the Rat Seminiferous Tubules. Comparison of the Stages of the Epithelial Cycle Isolated by Transillumination‐Assisted Microdissection
Authors: PARVINEN MARUI , RUOKONEN AIMO 
Published: December 2015

A microdissection procedure is described that allows the isolation of segments of rat seminiferous tubules in different stages of the epithelial cycle. This procedure is based on spermatogenic stage‐dependent differences in the transillumination pattern along the freshly isolated, unstained seminiferous tubules. It allows collection of segments representing defined stages in amounts sufficient for biochemical studies (5–10 mg wet weight).Tubular segments at stages I, II–III, IV–V, VI, VIIa–b, VIIc–d, VIII, IX–XI, XII, and XIII–XIV have been used for measurement of endogenous concentrations of testosterone, 5α‐dihydrotestosterone, progesterone, and 17α‐hydroxyprogesterone by radioimmunoassays after Lipidex‐5000 chromatography. Testosterone was the most abundant steroid at all stages of the cycle, and its concentration at stage VIII was significantly higher than at any other stage. The concentration of 5α‐dihydrotestosterone was markedly lower and did not exhibit similar differences in distribution. The levels of progesterone and 17α‐hydroxyprogesterone were the same at all stages of the cycle of the seminiferous epithelium.A number of morphologic and biochemical observations suggest unique changes in the metabolic activity of both germ cells and Sertoli cells at stages VII and VIII of the cycle. The possible androgen control of these changes is discussed.
The Relationships Between Serum Testosterone and Prolactin Levels and Nocturnal Penile Tumescence (NPT) in Impotent Men
Authors: CUNNINGHAM GLENN R. , KARACAN ISMET , WARE J. CATESBY , LANTZ GORDON D. , THORNBY JOHN I. 
Published: December 2015

Serum testosterone (T) and prolactin (PRL) levels, nocturnal penile tumescence (NPT), penile and brachial blood pressure, and bulbocavernosus reflex latency (BCR) were assessed in 172 impotent men ranging in age between 19 and 60 years. Patients were also examined for Peyronie's disease. Patients who were taking drugs that are known to affect T or PRL levels, and those with overt primary or secondary testicular failure, liver disease or renal disease, were excluded from the study.Androgen deficiency (T <264 ng/dl) or hyperprolactinemia (PRL > 15 ng/ml) was observed in 22% of the patients, and 62% had abnormal NPT. We found that NPT was abnormal in 11 of the 12 men (91.7%) with T levels below 251 ng/dl or with PRL levels above 25 ng/ml (P <.001), and in 81.0% to 93.8% of men with other detectable and relevant medical abnormalities. Eight of the 12 patients with T levels below 251 ng/dl or PRL levels above 25 ng/ml had other detectable abnormalities. In contrast, NPT was abnormal in only 10 of 34 men (29.4%) who had no apparent medical abnormality or disease.These studies indicate that in impotent men, T deficiency and/or hyperprolactinemia, alone or with other conditions, are associated with abnormal NPT sufficiently frequently to warrant routine measurement of both T and PRL, particularly if it can be demonstrated that correction of these abnormalities restores potency.
Morphology of Spermatozoa in Infertile Men with and without Varicocele
Authors: PORTUONDO JOSÉ A. , CALABOZO MARCELO , ECHANOJAUREGUI ABEL D. 
Published: December 2015

This study was carried out to evaluate the morphology of spermatozoa in infertile men with and without varicocele. A series of 285 ejaculates were fully evaluated for seminal volume, sperm count, motility, and morphology, and classified into fertile (165 subjects), infertile without varicocele (93 subjects) and infertile with varicocele (27 subjects). Sperm morphology was classified by multiple entry criteria and recorded as normal, abnormal with head, midpiece, or tail single anomaly or abnormal with simultaneous multiple abnormalities.Semen volume was almost identical in the three groups. Among the infertile men, sperm count was lower in those having a varicocele, but conversely those with varicocele had a higher percentage of motile spermatozoa, higher percentage of spermatozoa with forward movement and higher sperm velocity. There were higher proportions of spermatozoa with abnormal morphology, total number of anomalies, and multiple anomalies in infertile men, both with and without varicocele, than in fertile men. The percentage of abnormal spermatozoa was higher in infertile men with varicocele than in those without varicocele. The pattern of sperm morphology differed between the infertile and the fertile group, and with the presence or absence of varicocele. In the presence of varicocele, only the incidence of elongated (tapered) forms was significantly increased.
Seasonal Changes in Steroidogenesis in the Testis of the Rhesus Monkey (Macaca mulatto)
Authors: HIGASHI YOTSUO , TAKAHASHI JUN , YOSHIDA KEN‐ICHIRO , WINTERS STEPHEN J. , OSHIMA HIROYUKI , TROEN PHILIP 
Published: December 2015

To investigate the influence of seasonal changes from breeding to nonbreeding season on testicular steroidogenesis in the adult rhesus monkey, two animals were hemiorchidectomized in November and the second testis of each was removed the following April. Intratesticular steroid concentrations related to the formation of testosterone from pregnenolone were measured by radioimmunoassay. Related steroidogenic enzyme activities were also assayed and dynamic studies of the bioconversion of radiolabeled precursor steroids by testicular microsomes were performed.Testosterone was synthesized from pregnenolone through both dehydroepiandrosterone and 17α‐hydrox‐yprogesterone. No distinct differences were found in the testosterone biosynthetic pathway between testes in breeding and nonbreeding seasons. In the breeding season, intratesticular testosterone concentrations, the sum of intratesticular steroids measured, and the ratio of testosterone to the steroid sum were increased when compared to those in the nonbreeding season. No major seasonal changes in microsome enzyme activities were found, although enzyme activities, except for Δ5‐3β‐hydroxysteroid dehydrogenase for C21‐steroids, were slightly higher in the breeding season. We conclude that increased testosterone production in the testis during the breeding season is due primarily to increased pregnenolone supply from Leydig cell mitochondria and, to a lesser extent, to an enhanced pregnenolone bioconversion to testosterone in the microsomes.
Origin and Fate of Autophagosomes in Leydig Cells of Normal Adult Rats
Authors: TANG X. M. , CLERMONT Y. , HERMO L. 
Published: December 2015

Autophagosomes were observed frequently in electron microscope photographs of Leydig cells from normal adult rat testis. Their formation, evolution and fate were analyzed morphologically in preparations treated to show cytidine monophosphatase (CMPase) and glucose‐6‐phosphatase (G‐6‐Pase) activities and in animals sacrificed at various time intervals ranging from 5 min to 6 hrs after a single intratesticular injection of cationic ferritin. Analysis of the morphologic data led to the following interpretation and model. Preautophagosomal structures appeared as flattened, elongated membranous profiles. These expanded, took on a C‐shape and fused at their edges to demarcate a small cytoplasmic territory containing normal‐looking smooth endoplasmic reticulum (ER) and mitochondria. Such early autophagosomes were thus delimited by two membranes separated by a narrow lumen. Following fusion of these elements with secondary lysosomes, the space between the two membranes increased in size, the inner membrane disintegrated and the enclosed organelles no longer could be identified. The late autophagosomes then reached the cell surface and appeared to exocytose their residual content.In contrast to secondary lysosomes and trans‐Golgi elements, which were CMPase‐positive, the preautophagosomal flattened membranous elements and early autophagosomes were CMPase‐negative. The late autophagosomes on the contrary were CMPase‐positive. While ER cisternae were G‐6‐Pase‐positive, the pre‐, early and late autophagosomal structures were unreactive for this enzyme. Cationic ferritin tracer experiments showed that only late autophagosomes became labeled with cationic ferritin following their fusion with secondary lysosomes into which the tracer had accumulated following its endocytosis from the cell surface. These various data suggested that the membrane‐delimiting autophagosomes did not derive from the ER or the Golgi apparatus and that autophagocytic structures seemingly acquired their hydrolytic enzymes by fusion with secondary lysosomes of endocytic origin.
BRIEF REVIEWS OF SOME RECENT BOOKS
Authors: BREWER JOHN M. 
Published: December 2015

Book reviews in this article:Our Boys. By Howard G. Burdge.Labor's Challenge to the Social Order. By John Graham Brooks.Teaching Home Economics. By Anna M. Cooley and others.Vocational Home‐making Education. Edited by David Snedden.Women Professional Workers. By Elizabeth Kemper Adams.Success Through Vocational Guidance. By James McKinney and A. M. Simons.Preparing for the World's Work. By Isaac Doughton.
Spontaneous uterine cornual rupture at 26 weeks' gestation in an interstitial heterotopic pregnancy following in vitro fertilization
Authors: Paradise Courtney , Carlan S.J. , Holloman Conisha 
Published: December 2015

ABSTRACTInterstitial implantation in a heterotopic pregnancy is extremely rare, and despite currently available diagnostic modalities, early identification of an interstitial ectopic pregnancy remains difficult. This report describes a case of spontaneous cornual rupture at 26 weeks' gestation in a woman with diamniotic dichorionic twins that resulted in live births. The patient had previously undergone laparoscopic bilateral salpingectomy, and the pregnancy was conceived with in vitro fertilization. Interstitial implantation in a heterotopic pregnancy can go unrecognized, resulting in increased maternal and infant morbidity and mortality. © 2015 Wiley Periodicals, Inc. J Clin Ultrasound 44:322–325, 2016
Uncertainties in the simulation of precipitation in selected regions of humid and dry climate
Authors: Ring C. , Mannig B. , Pollinger F. , Paeth H. 
Published: December 2015

ABSTRACTChoices of adaption strategies to climate change are often based on the knowledge summarized in the Intergovernmental Panel on Climate Change (IPCC) Assessment Reports. For climate impact research, precipitation is of high relevance and often used as a criterion for climate model evaluation. Therefore, we assess simulated precipitation of 24 models of Phase 3 and 26 models of Phase 5 of the Coupled Model Intercomparison Project (CMIP) of the latest Assessment Reports of the IPCC, altogether 149 individual simulations. These model simulations and the two multi‐model means are evaluated against five observational datasets from different sources over the late 20th century. Monthly, seasonal and annual means are analysed based on five selected study areas, leading to a comparative regional assessment of model quality. For the more recent CMIP ensemble mean, the overall bias has been reduced. Aside from some underestimation in summer and overestimation in winter in wet regions, there is still a considerable model bias (40–150% compared to observational data) especially in the arid areas of our study. None of the single models is superior in all five regions, although for all regions models can be identified that show excellent results. Additionally, the relationship between horizontal and vertical model resolution and the model bias is evaluated. Despite some tendencies, the results show no significant dependency of model performance on the range of resolution in CMIP3 and CMIP5. Thus, more sophisticated metrics have to be applied to construct subensembles which have higher skill and lower spread of simulated precipitation.
Preparation of polypropylene‐based nanocomposites using nanosized MCM‐41 as support and in situ polymerization
Authors: González Darío M , Quijada Raúl , Yazdani‐Pedram Mehrdad , Lourenço Joao Paulo , Ribeiro M Rosario 
Published: December 2015

AbstractMCM‐41 nanoparticles were used for preparing nanocomposites through the in situ polymerization of propylene. The performance of the catalytic system and the final properties of the materials obtained are highly dependent on the methodology used for impregnation of the catalyst onto the support particles, and therefore an optimization study for the impregnation methodology of the catalyst (Me2Si(Ind)2ZrCl2) was carried out. Two different methodologies were used; the results in terms of catalytic activity and polymer molecular masses indicated that the most promising one involved the pre‐activation of the catalyst with the cocatalyst, methylaluminoxane, followed by impregnation onto the MCM‐41 nanoparticles. Thus, an optimized route for the preparation of polypropylene nanocomposites achieving significant improvements in catalyst activity was developed. The nanocomposite materials were characterized by GPC, TGA and DSC. The dispersion state and the size of the nanoparticles incorporated in the polypropylene matrix were investigated by transmission electron microcopy. Additionally, this methodology allows simultaneous control of the desired amount of support and the concentration of catalyst to be used in the in situ polymerization. © 2015 Society of Chemical Industry
The Raman spectra of α‐ and β‐trithioacetaldehyde and of monothioparaldehyde
Authors: Gerding H. , Karsten J. G. A. 
Published: December 2015

AbstractThe Raman spectra of solutions of α‐trithioacetaldehyde (m.p. 101°), β‐trithioacetaldehyde (m.p. 126°) and monothioparaldehyde (m.p. 54°) in carbon tetrachloride have been determined.The results in the case of the two trithioacetaldehydes make it probable, that the β‐form possesses the cis‐configuration, in agreement with the conclusion of Chattaway and Kellett, derived from chemical evidence.