bluuebunny/crossref_metadata_2025 huggingface dataset:
Hippocampal Network Dynamics Constrain the Time Lag between Pyramidal Cells across Modified Environments
Authors: Diba Kamran , Buzsáki György
Published: December 2008

The hippocampus provides a spatial map of the environment. Changes in the environment alter the firing patterns of hippocampal neurons, but are presumably constrained by elements of the network dynamics. We compared the neural activity in CA1 and CA3 regions of the hippocampus in rats running for water reward on a linear track, before and after the track length was shortened. A fraction of cells lost their place fields and new sets of cells with fields emerged, indicating distinct representation of the two tracks. Cells active in both environments shifted their place fields in a location-dependent manner, most notably at the beginning and the end of the track. Furthermore, peak firing rates and place-field sizes decreased, whereas place-field overlap and coactivity increased. Power in the theta-frequency band of the local field potentials also decreased in both CA1 and CA3, along with the coherence between the two structures. In contrast, the theta-scale (0–150 ms) time lags between cell pairs, representing distances on the tracks, were conserved, and the activity of the inhibitory neuron population was maintained across environments. We interpret these observations as reflecting the freedoms and constraints of the hippocampal network dynamics. The freedoms permit the necessary flexibility for the network to distinctly represent unique patterns, whereas the dynamics constrain the speed at which activity propagates between the cell assemblies representing the patterns.
Neural Substrates of Sound–Touch Synesthesia after a Thalamic Lesion
Authors: Beauchamp Michael S. , Ro Tony
Published: December 2008

Neural plasticity induced by stroke can mediate positive outcomes, such as recovery of function, but can also result in the formation of abnormal connections with negative consequences for perception and cognition. In three experiments using blood-oxygen level dependent (BOLD) functional magnetic resonance imaging, we examined the neural substrates of acquired auditory-tactile synesthesia, in which certain sounds can produce an intense somatosensory tingling sensation in a patient with a thalamic lesion. Compared with nine normal controls, the first experiment showed that the patient had a threefold greater BOLD response to sounds in the parietal operculum, the location of secondary somatosensory cortex. We hypothesized that this abnormal opercular activity might be the neural substrate of the patient's synesthesia. Supporting this hypothesis, the second experiment demonstrated that sounds that produced no somatosensation did not evoke a BOLD response in the operculum, while sounds that produced strong somatosensations evoked large BOLD responses. These abnormal responses may have resulted from plasticity induced by the loss of somatosensory inputs. Consistent with this idea, in the third experiment, BOLD responses to somatosensory stimulation were significantly weaker in the patient's operculum than in normal controls. These experiments demonstrate a double dissociation in the patient's secondary somatosensory cortex (increased responses to auditory stimulation and decreased responses to somatosensory stimulation), and suggest both that stroke-induced plasticity can result in abnormal connections between sensory modalities that are normally separate, and that synesthesia can be caused by inappropriate connections between nearby cortical territories.
Normal Electrocortical Facilitation But Abnormal Target Identification during Visual Sustained Attention in Schizophrenia
Authors: Clementz Brett A. , Wang Jun , Keil Andreas
Published: December 2008

Attentional deficits in schizophrenia have been investigated using target identification tasks which conflate the abilities to successfully (1) attend to possible target locations and (2) detect target events. Whether compromised attentional selectivity or abnormal target detection causes schizophrenia subjects' poor performance on visual attention tasks, therefore, is unknown. To address this issue, we measured the neural activity (using electroencephalography) of 17 schizophrenia and 17 healthy subjects during a target identification task. Participants viewed superimposed images (horizontal and vertical bars differing in color) and attended to one image to identify bar width changes in specific locations. Bars were frequency tagged so attention directed to unique parts of the images could be tracked. Steady-state visual evoked potentials (ssVEPs) were used to quantify attention-related neural activity to specific parts of the visual images. Behavioral performance and event-related potentials (ERPs) in response to the target events were used to quantify target detection abilities. For both schizophrenia and healthy subjects, attending to specific parts of the attended image enhanced brain activity related to attended bars and reduced activity evoked by unattended bars. Activity in relation to the spatially overlapping unattended image was unaffected. Schizophrenia patients, however, were impaired on target detection abilities on both behavioral and brain activity measures. Target-related behavioral and brain activity measures were highly correlated in both groups. These findings indicate that deficient target detection rather than compromised attentional selectivity accounts for previously reported visual attention deficits in schizophrenia.
A Critical Window for Experience-Dependent Plasticity at Whisker Sensory Relay Synapse in the Thalamus
Authors: Wang Hao , Zhang Zhong-wei
Published: December 2008

This study investigated the role of sensory experience in the refinement of whisker sensory relay synapses in the ventral posterior medial nucleus (VPm) of the murine thalamus. Sensory deprivation was done by whisker plucking, and synaptic connectivity was determined by whole-cell patch-clamp recording in acute slices. Sensory deprivation started at P12–P13, but not at P16, disrupted the elimination of VPm relay synapses. The majority of deprived neurons received multiple relay inputs, whereas the majority of nondeprived neurons received a single relay input. Sensory deprivation started a few days earlier at P10, however, had no effect on synapse elimination. The disruption of synapse elimination was associated with a delay in synapse maturation. The AMPA/NMDA ratio of EPSC was significantly smaller in deprived neurons. On the other hand, deprivation had no effect on the peak amplitude or decay time constant of the NMDA component, or theI–Vrelationship of the AMPA component, nor does it affect the paired-pulse ratio of EPSCs. The reduction in the AMPA/NMDA ratio was already evident within 24 h of whisker plucking, and the effect is associated with a reduction in the amplitude of quantal AMPA events. Thus, P12–P13 is a critical period for experience-dependent refinement at the whisker sensory relay synapse in the VPm.
Adrenal endothelin-1 levels are not associated with aldosterone secretion in primary aldosteronism
Authors: Morello F , Schiavone D , Mengozzi G , Bertello C , Liew C C , Bisbocci D , Mulatero P , Veglio F
Published: December 2008

Background

Endothelin-1 (ET-1) may function as an aldosterone secretagogue and, in turn, aldosterone can upregulate ET-1 expression. Hence, the existence of a feedforward loop involving ETs and aldosterone has been speculated in primary aldosteronism (PA). In the present study, we sought to examine ET-1 secretion from the adrenal glands in patients with PA.

Design

We determined ET-1 levels in blood samples obtained during adrenal venous sampling of patients affected by PA (n=17). Furthermore, we examined the mRNA expression of the ET system in tissue samples from aldosterone-producing adenomas (APAs, n=9) and control normal adrenals (n=3).

Methods

Blood ET-1 levels were determined by RIA. Tissue mRNA expression of the ET system was assayed with Affymetrix microarrays.

Results

ET-1 levels did not differ between inferior vena cava and adrenal vein blood in both bilateral adrenal hyperplasia and APA patients. Moreover, cortisol-normalized ET-1 levels did not show lateralized adrenal ET-1 secretion in APAs. Through gene expression profiling with microarray performed in a distinct set of APA individuals (n=9), we confirmed the adrenal expression of a complete ET system, but we did not detect a significant upregulation of ET components within the APA tissue compared with normal adrenals.

Conclusions

The present data argue against the hypothesis of increased ET-1 secretion from APAs and do not support a general role for adrenal ET-1 in the vascular pathophysiology of PA.
Testicular angiogenic activity in response to food restriction in rabbits
Authors: Carvalho M , Mateus L , Afonso F , Van Harten S , Alfaro Cardoso L , Redmer D A , Ferreira-Dias G
Published: December 2008

The objective of this study was to evaluate the effects of two different levels of food restriction on testicular angiogenic activity, microvascularization, tissue growth, and regression, using the rabbit as a study model. The rabbits (Oryctolagus cuniculus cuniculus) were randomly assigned to a control group (A,n=5), fedad libitum, and to groups B (n=5) and C (n=5), with two different levels of food restriction. Food restriction was responsible for a 21.2% decrease in body weight in group B and 34.7% in group C. Testis explants were cultured for 24 h and conditioned media were tested for their ability to stimulate mitogenesis of bovine aortic endothelial cells (BAEC). There was an increase in testicular microvascular area and mitogenesis of BAEC in group C rabbits. Despite no change in testicular DNA concentration among groups, food restriction decreased both RNA and protein compared with control. No treatment differences in the percentage of seminiferous tubules filled with all stages of spermatogenesis (spermatogonia, spermatocytes, and spermatids) and spermatozoa, as well as the area occupied by seminiferous tubules, were observed. Nevertheless, serum testosterone was markedly less in group C compared with groups A and B. These results suggest that angiogenesis may play a role in overcoming testicular nutritional impairment in rabbits subjected to food restriction.
Type 2 diabetes and metabolic syndrome as conditions leading to malignant tumors
Authors: Halmos Tamás , Suba Ilona
Published: December 2008

Az utóbbi években egyre több bizonyíték szólt a metabolikus szindróma és a 2-es típusú diabetes mellitus karcinogén hatásáról. A bizonyítékok között első helyen az epidemiológiai észlelések állnak. A különböző tumorfajták és a metabolikus szindróma, illetve a 2-es típusú diabetes mellitus között nemek, rasszok és földrajzi elterjedtség szerint eltérő mértékben mutatható ki kauzális összefüggés. A lehetséges közös patomechanizmusok az elhízáskor a zsírszövetben excesszíven termelődő adipokinek, a tartós és postprandialis hyperglykaemia, a hyperinsulinismus és az inzulinrezisztencia, egyéb növekedési faktorok, mint a proinzulin, inzulinszerű növekedési faktor-1, reaktív oxigén-szabadgyökök, angiogenezis, inflammáció és gyulladásos citokinek sejtproliferatív hatásai. Kiderült, hogy a peroxiszómaproliferátor aktiválta receptoroknak és az őket szabályozó ubiquitin proteaszómarendszernek is meghatározó szerepe van a sejtproliferáció befolyásolásában. Ezek a mechanizmusok metabolikus szindrómában mind atherosclerosis, mind karcinogenezis irányában kockázati tényezőként szerepelnek. Ez a felismerés új utat nyithat mindkét kórkép megelőzése és kezelése szempontjából.
Physiological and pathophysiological significance of the antimicrobial (host defensive) small peptides
Authors: Lapis Károly
Published: December 2008

Az antimikrobiális peptidek kicsiny kationos, amfofil molekulák, amelyek széles spektrumú antimikrobiális aktivitással rendelkeznek, és az élő szervezetek fontos, ősi védekezési eszközei. E peptidek elsősorban a neutrofilekben, más fehérvérsejtekben és a szervrendszerek környezeti behatásoknak kitett nyálkahártyájának hámjában termelődnek. Egy részük konstitutív módon, más részük csak indukciós behatásokra (baktériumtermékek, gyulladáskeltő citokinek) jön létre. Biokémiai sajátságaikban e peptidek igen eltérőek, de típusosan a mikrobaölő hatásukat azok membránjának direkt szétszakítása révén fejtik ki, ami a sejttartalom kiürüléséhez és sejthalálhoz vezet. Emberben e peptidek fő csoportjait a defensinek, a cathelicidinek és a histatinok képezik. Újabb vizsgálatok feltárták, hogy e peptidek antimikrobiális hatásukon kívül sok más, a gazda védelmét szolgáló aktivitással is rendelkeznek. Képesek a baktériumtoxinok neutralizálására és a veleszületett és szerzett immunfolyamatok modulálására. Mivel e peptidek közül számos az antibiotikumokkal szemben rezisztenssé vált baktériumok ellen is hatásosnak bizonyult, azok modellként szolgálnak új antimikrobiális ágensek tervezéséhez.
A resiliência de profissionais angolanos
Authors: Vergara Sylvia Constant
Published: December 2008

Este artigo focaliza o atual esforço de profissionais de Angola, do continente africano, para superar os efeitos devastadores da colonização do país, seguida de uma brutal guerra civil. Em indivíduos e comunidades, há capacidade de regeneração quando cessam eventos que propiciam pressões desgastantes. A teoria da resiliência explica essa propriedade. Inserida na esfera da subjetividade, tal teoria contribuiu para alcançar o objetivo do estudo: descobrir que forças ligadas a sentimentos impulsionaram ou facilitaram as ações de angolanos, profissionais de organizações públicas e privadas, para a superação de dificuldades. A amostra de 46 profissionais foi obtida por acessibilidade. O método escolhido para coletar os dados no campo e tratá-los foi a análise de conteúdo. A literatura e as respostas dos sujeitos da investigação permitiram a formação de uma grade mista que redundou em quatro categorias: amor à pátria; solidariedade; esperança; recursos intangíveis. Essas categorias agregam as forças ligadas a afetos explicitadas pelos pesquisados e, portanto, as bases resilientes dos sujeitos da investigação.
Propuesta de una escala para medir la calidad del servicio de los centros de atención secundaria de salud
Authors: Torres Moraga Eduardo , Lastra Torres Jorge
Published: December 2008

El Ministerio de Salud en Chile se ha planteado como uno de sus principales objetivos, proveer servicios acorde a las expectativas de la población. Para lograrlo, se requiere necesariamente, conocer cuál es la calidad del servicio ofrecida por los centros de salud. En Chile, los centros de atención secundaria, no han desarrollado escalas de calidad del servicio que tengan un buen grado de validez, fiabilidad y dimensionalidad. Este artículo, propone una escala que cumpla estas condiciones, para medir de manera óptima la calidad del servicio que los Centros de Atención Secundaria ofrecen a sus pacientes. Para lograr este objetivo, se aplicó una encuesta estructurada y posteriormente se realizó un exhaustivo análisis psicométrico de los datos, a través de una serie de análisis exploratorios y confirmatorios que incluyó ecuaciones estructurales. Este estudio permitió construir y proponer una escala fiable, válida y con buen grado de dimensionalidad, compuesta por cinco subescalas claramente relacionadas e integradas en un único constructo. Estas son: confiabilidad, empatía, capacidad de respuesta, accesibilidad y tangibles.
Iniciação científica na graduação: o que diz o estudante de medicina?
Authors: Oliveira Neilton Araújo de , Alves Luiz Anastácio , Luz Maurício Roberto
Published: December 2008

A educação médica interessa e repercute em todo o mundo e de forma cada vez mais acentuada, em função da globalização. No Brasil, essa discussão, intensificada com o processo de construção do SUS, foi ampliada a partir das Diretrizes Curriculares Nacionais da Medicina, mas pouco se discute sobre ensino médico e pesquisas. No Enade 2007, 39% dos alunos informaram iniciação científica regulamentar em seu curso; 12% declararam existir sem regulamentação e 6,5% informaram a existência de iniciação científica sem integralização curricular; 10,9% disseram que não é oferecida e 31% não souberam opinar. No último Provão, em 2003, 20,9% dos alunos responderam que a participação em iniciação científica contribuiu para sua formação e 30,7% declararam não ter participado desse tipo de programa. Este estudo verificou junto aos estudantes do sexto ano, em seis escolas médicas de quatro estados brasileiros, a existência de iniciação científica em seus cursos, a participação ou não nessas atividades e os possíveis motivos para a não participação ou sua inexistência. Mesmo sendo crescente a participação de alunos de graduação em iniciação científica, ainda são muitas as razões para a não realização ou não participação dos alunos. Oitenta e quatro por cento dos alunos defendem a obrigatoriedade da iniciação científica na graduação médica.
Prevalência de sintomas depressivos entre estudantes de medicina da Universidade Federal de Uberlândia
Authors: Abrão Carolina Borges , Coelho Ediane Palma , Passos Liliane Barbosa da Silva
Published: December 2008

INTRODUÇÃO: A formação médica expõe o estudante de Medicina a experiências de estresse, tornando-o potencialmente vulnerável a distúrbios emocionais. OBJETIVO: Conhecer a prevalência de sintomas depressivos entre os estudantes de Medicina da Universidade Federal de Uberlândia. MÉTODO: Os sintomas depressivos foram rastreados por meio do Inventário de Beck (IDB), aplicado a 81% dos estudantes matriculados no primeiro semestre de 2004. Os pontos de corte para ausência de sintomas depressivos, sintomas leves, moderados e graves foram, respectivamente, 0-3, 4-7, 8-15 e 16 ou mais. Levantaram-se dados demográficos por meio de questionário. RESULTADOS: Dentre os 400 acadêmicos avaliados, houve predomínio de jovens, do sexo feminino, solteiros, procedentes de Uberlândia e que moram com os pais. A prevalência de sintomas depressivos foi de 79%, sendo 29% com grau leve; 31% moderado e 19,25% grave. CONCLUSÃO: Os resultados indicam uma proporção de sintomas depressivos superior à encontrada na literatura referente a estudantes de Medicina. As excessivas cargas horárias e a ansiedade progressiva com a finalização do curso merecem maior atenção no processo de mudança curricular.
Impacto da tecnologia da informação na gestão das cadeias de suprimentos: um estudo de casos múltiplos
Authors: Maçada Antonio Carlos Gastaud , Feldens Luis Felipe , Santos André Moraes dos
Published: December 2008

A gestão da cadeia de suprimentos é reconhecida como uma importante área para a inovação e investimento em Tecnologia da Informação (TI). Os investimentos em TI continuam sendo questão estratégica central em empresas que buscam ganhar vantagem competitiva em um ambiente cada vez mais dinâmico, mesmo sabendo que o impacto não é completamente entendido. O objetivo da pesquisa é identificar e analisar os impactos da TI no processo de gestão da cadeia de suprimentos e validar o conjunto de variáveis selecionadas na literatura de Sistemas de Informações (SI). Para isso é utilizado o estudo de casos múltiplos em empresas dos setores Metal Mecânico, Petroquímico e Varejo. As entrevistas com os executivos e observações revelaram a importância estratégica que a TI exerce no processo de gestão das cadeias de suprimento e também foram identificados impactos positivos da TI no conjunto de variáveis estratégicas selecionadas na revisão da literatura.
Clinical formulas, mother's opinion and ultrasound in predicting birth weight
Authors: Torloni Maria Regina , Sass Nelson , Sato Jussara Leiko , Renzi Ana Carolina Pinheiro , Fukuyama Maísa , Lucca Paula Rubia de
Published: December 2008

CONTEXT AND OBJECTIVE: Accurate fetal weight estimation is important for labor and delivery management. So far, there has not been any conclusive evidence to indicate that any technique for fetal weight estimation is superior to any other. Clinical formulas for fetal weight estimation are easy to use but have not been extensively studied in the literature. This study aimed to evaluate the accuracy of clinical formulas for fetal weight estimation compared to maternal and ultrasound estimates. DESIGN AND SETTING: Prospective study involving 100 full-term, cephalic, singleton pregnancies delivered within three days of fetal weight estimation. The setting was a tertiary public teaching hospital in São Paulo, Brazil. METHODS: Upon admission, the mother's opinion about fetal weight was recorded. Symphyseal-fundal height and abdominal girth were measured and two formulas were used to calculate fetal weight. An ultrasound scan was then performed by a specialist to estimate fetal weight. The four estimates were compared with the birth weight. The accuracy of the estimates was assessed by calculating the percentage that was within 10% of actual birth weight for each method. The chi-squared test was used for comparisons and p < 0.05 was considered significant. RESULTS: The birth weight was correctly estimated (Â± 10%) in 59%, 57%, 61%, and 65% of the cases using the mother's estimate, two clinical formulas, and ultrasound estimate, respectively. The accuracy of the four methods did not differ significantly. CONCLUSION: Clinical formulas for fetal weight prediction are as accurate as maternal and ultrasound estimates.
The male biological clock is ticking: a review of the literature
Authors: Pasqualotto Fabio Firmbach , Borges Júnior Edson , Pasqualotto Eleonora Bedin
Published: December 2008

The term biological clock is usually used by physicians and psychologists to refer to the declining fertility, increasing risk of fetal birth defects and alterations to hormone levels experienced by women as they age. Female fecundity declines slowly after the age of 30 years and more rapidly after 40 and is considered the main limiting factor in treating infertility. However, there are several scientific reports, chapters in books and review articles suggesting that men may also have a biological clock. The aim of our study was to conduct a review of the literature, based on the Medical Literature Analysis and Retrieval System Online (Medline), to evaluate the male biological clock. After adjustments for other factors, the data demonstrate that the likelihood that a fertile couple will take more than 12 months to conceive nearly doubles from 8% when the man is < 25 years old to 15% when he is > 35 years old. Thus, paternal age is a further factor to be taken into account when deciding on the prognosis for infertile couples. Also, increasing male age is associated with a significant decline in fertility (five times longer to achieve pregnancy at the age of 45 years). Patients and their physicians therefore need to understand the effects of the male biological clock on sexual and reproductive health, in that it leads to erectile dysfunction and male infertility, as well as its potential implications for important medical conditions such as diabetes and cardiovascular diseases.
OVARIAN HORMONES AND CALCIUM METABOLISM
Authors: DUCKWORTH J. , ELLINGER GABRIELLE M.
Published: December 2008

In rats severely depleted by lactation on a Ca-deficient ration, body Ca was replenished at the same rate in normal and ovariectomized rats and in ovariectomized rats given oestrone and progesterone.
THE EFFECT OF OESTRONE AND PROGESTERONE ON THE HISTOLOGICAL STRUCTURE OF THE SYMPHYSIS PUBIS OF THE CASTRATED FEMALE MOUSE
Authors: HALL KATHLEEN
Published: December 2008

1. The effect on the symphysis pubis of oöphorectomized mice of oestrone (1·5 μg./day) and progesterone (1·0 mg./day) injected separately and simultaneously for 8–20 days has been investigated histologically.

2. A brief course of treatment with oestrone had a definite effect on the pelvis, greater than appears on X-ray photographs, but not comparable in intensity with that which follows the addition of relaxin.

3. The action of oestrone affected the dorsal bony walls of the two innominates, and started at the anterior symphysial borders. Simultaneous resorption of the outer or periosteal surfaces, and deposition of new bone on the endosteal surfaces occurred, until the marrow cavities were obliterated at least in the medial parts of the two innominates. Resorption then continued so that the solid symphysial borders of the bones gradually disappeared. No ligament proliferation occurred.

4. A vascular, richly nucleated tissue replaced the resorbed dorsal surfaces of the bones, and was thought to be derived mainly from the marrow. Many osteoclasts were present along the eroding surfaces but the origin and function of these enigmatic cells is still undecided.

5. When progesterone was given for periods up to 20 days the histological structure of the symphysis pubis was similar to that of untreated control animals.

6. When oestrone and progesterone were given simultaneously for periods up to 20 days changes were produced of the same type as, but much less pronounced than, those produced by oestrone alone.

7. The results of histological investigation support the conclusion that progesterone is not only ineffective in producing relaxation of the pelvis in the mouse but that, at least in certain dose ratios, it inhibits the action of oestrone on the symphysis.
THE EFFECT OF VARYING LEVELS OF THYROIDAL STIMULATION ON ADRENALS UNDER DIFFERENT ENVIRONMENTAL TEMPERATURES
Authors: MAQSOOD M.
Published: December 2008

The effect of thyroidal stimulation on the weight of adrenals of the growing male mouse, kept at environmental temperatures of 24 and 30° C. for 3–4 weeks, has been studied. The administration of thyroxine (as iodinated protein) in sufficient dosages caused a significant increase in the weight of the adrenals of male mice kept at 24° C. whereas thiouracil caused a significant decrease.

High environmental temperature alone caused a significant decrease in the weight of the adrenals, probably due to a decrease in the thyroid secretion rate which occurred at that temperature. The decrease in the weight of the adrenals was checked to some extent by the administration of very small doses of thyroxine; however, larger doses caused a decrease in the adrenal weight of the thyroprotein-treated mice. Hypothyroidism produced at 30° C. also resulted in a significant decrease in the weight of the adrenals.
THE RELATION OF AGE TO NUMBERS OF OOCYTES
Authors: MANDL ANITA M. , ZUCKERMAN S.
Published: December 2008

The total number of oocytes in the ovaries of the rat decreases with age, the relation between the two variates conforming to the exponential relation y = axb. The regression of oocyte numbers on age is defined by the equations log y = 4·334 − 0·378 log x for the figures provided by Arai [1920], and log y = 4·561 − 0·476 log x for our own observations, x being measured in days. The two values of 'a' and of 'b' do not differ significantly from each other.
THE NUMBER OF OOCYTES IN THE MATURE RHESUS MONKEY (MACACA MULATTA)
Authors: GREEN S. H. , ZUCKERMAN S.
Published: December 2008

Estimates have been made of the total number of oocytes in ovaries removed on different days of the menstrual cycle from twelve sexually mature rhesus monkeys. They have been analysed on two assumptions: (a) that no relation exists over the range of age studied between age and the number of oocytes present; and (b) that such a relation exists. The data were grouped in the following three temporal phases of the menstrual cycle: days 1–9, days 10–18, days 19–27. Statistical analysis failed to reveal any significant difference between the average total number of oocytes present at the beginning, the middle, or the end of the menstrual cycle.
THE ANTERIOR LOBE OF THE CATTLE PITUITARY
Authors: BASSETT E. G.
Published: December 2008

Some anatomical and histological features have been described of the pituitary glands of thirty mature cattle in various sexual conditions. The glands from five female calves and five foetuses have also been examined.

A cone of Wulzen was macroscopically observed in twenty-two of the thirty mature glands and in two calf glands.

Colloid was found to be a common constituent in the mature cattle pituitary and was seen in the cleft of thirteen glands, in blood vessels of fourteen and as anterior lobe cysts in twenty-four. Drops of intercellular colloid were present in all glands.

There was some evidence that the colloid drops and the formation of anterior lobe cysts might be associated.

As no colloid was seen in the calf or the foetal material, it seems likely that the various types of this substance are formed during the post-embryonic life of the animal.
RETINAL METABOLISM IN DIABETES: THE METABOLISM OF RETINAE OF NORMAL AND ALLOXAN-DIABETIC RABBITS
Authors: ILLING ELIZABETH K. B. , GRAY C. H.
Published: December 2008

The metabolism of the retinae from alloxan-diabetic rabbits has been compared with that of the retinae of normal rabbits. With glucose substrate, the Qo and QN2G were significantly lower in the alloxan-diabetic than in the normal rabbit retinae.

The Qo2 of the normal rabbit retinae was the same with pyruvate as substrate as with glucose.

With the retinae from alloxan-diabetic rabbits, the Qo2 with pyruvate as substrate was significantly greater than the Qo2 with glucose as substrate, as well as the Qo2 of the normal rabbit retinae with pyruvate substrate.
METHODS OF INDUCING MULTIPLE OVULATION IN CATTLE
Authors: ROWSON L. E.
Published: December 2008

Follicles in relatively large numbers (average 26) have been consistently produced by the injection of 3600 and 4500 i.u. of whole pregnant mares' serum, and to a slightly lesser degree (average 14), by the injection of similar amounts of commercial processed pregnant mares' serum.

Ovulation after this treatment has been spontaneous, but to a lesser degree when using the processed material (5·4% ovulations) than when using the whole plasma (24% ovulations).

The percentage of ovulations after this treatment has been increased by the intravenous injection of chorionic gonadotrophin at a dosage of 2000 i.u. (22% for processed material and 42% for whole serum). Where a large corpus luteum was present in the ovary during the time of treatment, the percentage ovulations was 52 as compared with only 14 in those cases in which no corpus luteum was present.

Injections of 20 mg. progesterone daily for 4 days after removal of the corpus luteum, and after the p.m.s. injections, had the same effect on the ovulation rate (55% ovulations) as the presence of a large corpus luteum.

Ova produced by either processed or whole serum can be fertilized fairly readily in the absence of a corpus luteum, but in its presence or after daily injections of progesterone, no fertilization takes place.

In the presence of a corpus luteum or after injections of progesterone, the ova travel down the Fallopian tube at a greatly increased rate, but were in some cases slowed up by the injection of oestrogens.
THE INDUCTION OF INTERMENSTRUAL BLEEDING IN NORMAL MONKEYS WITH DEOXYCORTICOSTERONE ACETATE AND TESTOSTERONE PROPIONATE
Authors: KROHN P. L.
Published: December 2008

Intermenstrual bleeding in normal monkeys can readily be induced by DOCA and with more difficulty by testosterone propionate.

The amount of DOCA required (c. 40–50 mg.) is greater than the amount of progesterone (c. 15–20 mg.) needed to induce bleeding. The amount of androgen required (c. 100 mg.) is higher still.
ADRENOCORTICOTROPHIC-LIKE ACTIVITY IN PLASMA
Authors: BORNSTEIN J. , GRAY C. H. , PARROTT DELPHINE M. V.
Published: December 2008

An acid acetone extract of human plasma has been shown to be active in partially maintaining the weight and histological structure of the adrenals of hypophysectomized rats. As extracts of this type have been previously shown to be active in the Sayer's test, it appears that ACTH may be demonstrable in human plasma.
PLASMA AND URINARY AMINO-ACIDS IN DIABETES
Authors: GRAY C. H. , ILLING ELIZABETH K. B.
Published: December 2008

The plasma concentration of α-amino N was determined in fifty-three diabetic patients. These diabetic patients included cases with and without ketosis, cases before and after insulin treatment, and cases whose diabetes started before and after the age of 40 years. None of the patients with ketosis was in coma or pre-coma. No significant difference from the normal plasma α-amino N concentration was observed in any of these six groups.

Qualitative chromatographic analysis and quantitative determinations of the amino-acid excretion of thirty-three and fourteen diabetic patients respectively, showed a significantly increased excretion of amino N during diabetic ketosis. This increase may be associated with an excess production of free amino-acids due to an increased secretion of adrenocorticotrophic hormone during diabetic ketosis.
STUDIES ON ANTIBODY FORMATION TO ACTH IN MAN
Authors: CLAYTON BARBARA E. , HARDISTY R. M. , PINNIGER J. L.
Published: December 2008

1. Complement-fixing antibody was found to develop in a patient suffering from acute disseminated lupus erythematosus, who received treatment with ACTH.

2. Bioassay experiments showed that this antibody had no antihormone properties.

3. Further experiments with different batches of ACTH, and with the organic residue left after extraction of ACTH, suggested that the antibody was produced in response to the injection of a pituitary impurity.

4. Neither complement-fixing antibodies to significant titre, nor precipitins could be demonstrated in the sera of nine other patients undergoing ACTH therapy. Total doses given varied from 520 to 9000 mg.
THE FATE OF EOSINOPHILS IN HORMONALLY INDUCED EOSINOPENIA AND ITS SIGNIFICANCE
Authors: GODLOWSKI Z. Z.
Published: December 2008

1. It is suggested that some of the circulating blood eosinophils are originally produced in the epithelial lining of the lower parts of the intestinal crypts, mainly in the small intestine but to a lesser extent in the colon. This cellular reaction may result from the penetration by the antigenic unsplit protein molecule from the lumen of the intestine into the epithelial cells, transforming these into new histological and biological units.

2. This process takes place in the normal intestinal mucosa. It is strongly intensified by the ingestion of antigenic proteins and various traumata inflicted on the intestinal canal.

3. White mice fed with de-antigenized proteins do not form a lymphocytic barrier in the lamina propria mucosae; eosinophils do not appear there until antigenic proteins are introduced into the diet.

4. Heparinization to a higher level than is required for the prevention of blood clotting, done prior to the injection of hormones causing eosinopenia, abolishes or significantly diminishes circulating eosinopenia or may actually increase the number of circulating eosinophils. Fluctuations result from two independent actions: mobilization of tissue eosinophils by heparin, and destruction of eosinophils by steroids in the circulating blood.

5. The eosinolytic action of adrenocortical steroids results from mediation in the catabolic phase of the intracellular metabolism of proteins. This action has been demonstrated in all white cells of the blood.

6. Hormonally induced eosinopenia, in men and in dogs, results from the eosinolysis which takes place in the blood. The other white blood cells are also affected by the same action. The final number of polymorphs is masked by their mobilization set up by cortical steroids through some unknown mechanism. Lymphocytes are less sensitive than eosinophils to the lytic action of cortical steroids.
THE CALCULATION OF THE DOSE-RESPONSE LINE IN QUANTAL ASSAYS WITH SPECIAL REFERENCE TO OESTROGEN ASSAYS BY THE ALLEN-DOISY TECHNIQUE
Authors: BIGGERS J. D.
Published: December 2008

A comparison has been made of the probit, logit, angular and rectangular transformations in the calculations of quantal dose response lines by the method of maximum likelihood. Data from Allen-Doisy oestrogen assays have been employed.

Studies of the χ2 test for linearity and of the calculated median effective dose (m.e.d.) show no significant differences between the results obtained with any of the transformations.

When group numbers are equal the angular transformation is the method of choice as the constant weighting factor reduces the amount of computation involved.

The significance of these results, both in the calculation of the m.e.d. or relative potency and to the theory of drug action, has been discussed.
THE OVARIAN CONTROL OF THE HYPOPHYSIAL GONADOTROPHIC FUNCTION
Authors: BRUZZONE S. , LIPSCHUTZ A. , NIEDMANN L.
Published: December 2008

Those aspects of ovarian function which are thought to be involved in the regulation of pituitary gonadotrophic activity have been experimentally dissociated: (1) hormone production without normal 'competitive consumption' of gonadotrophin (in an ovarian fragment in situ), and (2) 'consumption' of gonadotrophin unaccompanied by hormone activity (in an intrasplenic graft).

The abnormal behaviour displayed by an ovarian remnant maintained alone in the body for long experimental periods and manifested by cyst formation of the rete ovarii (method II, see Text-fig. 1) is not counteracted by an intrasplenic ovarian graft allowed to act only by virtue of its 'consumption' of gonadotrophin (method V).

On the other hand, the ovarian fragment, even when not showing the same degree of follicular development and luteinization as an entire ovary in situ, counteracts to a very considerable degree the production of haemorrhagic follicles in the intrasplenic graft (methods IV and V). Therefore, the ovarian remnant is able to exert some control over the anterior pituitary, presumably by producing oestrogen.

In the presence of an intrasplenic graft luteinization is less pronounced in an ovarian remnant (method V) than in the entire ovary retained in situ (method VI). Correspondingly, luteinization in the intrasplenic graft is more pronounced in the first than in the second case. While 'competitive consumption' of gonadotrophin is probably a significant factor in follicular development and luteinization, it has not been proved conclusively that it also controls production and release of the pituitary gonadotrophic hormones.
THE MECHANISM OF THE PROTECTIVE ACTION OF CLAMPING THE RENAL PEDICLES OF DOGS WITH ALLOXAN DIABETES
Authors: ARTETA J. L.
Published: December 2008

Clamping of the renal vessels gives rise to a reflex change of circulation at the level of the vascular zone innervated by the splanchnic nerves.

Bilateral cutting of the splanchnic nerves and of the inferior part of the sympathetic chain at the level of the thorax prevents the reflex, and annuls the protective action of clamping the vascular pedicles of the kidney.

Renal lesions are not absolutely necessary for the production of alloxan diabetes, but may aggravate diabetes, probably by adding the toxic effects of retention of urine.
THE EFFECT OF EXOGENOUS THYROXINE ON RADIO-IODINE UPTAKE IN NORMAL SUBJECTS AND IN CASES OF THYROTOXICOSIS IN REMISSION
Authors: MORGANS MARGARET E. , OLDHAM A. K. , TROTTER W. R.
Published: December 2008

Radio-iodine uptake has been measured by the neck/thigh ratio, before and at the end of a course of oral sodium-l-thyroxine 0·4 mg. given daily for two weeks.

Twenty normal subjects, thirteen patients with non-toxic goitres and thirteen patients who had recovered from thyrotoxicosis have been studied in this way.

In all three groups there was a significant fall in the neck/thigh ratio while the subjects were taking thyroxine.

The mean fall of the neck/thigh ratio after taking thyroxine did not differ significantly in the normal and recovered thyrotoxic groups.

These results do not support the idea that failure to respond to thyroxine is a constitutional feature of subjects who have had an attack of thyrotoxicosis.
STUDIES ON THE METABOLISM OF ADRENAL STEROID HORMONES
Authors: NISSIM J. A.
Published: December 2008

Incubation of DCA with minced adrenal tissue resulted in an increase of gluco-corticoid activity. The conversion percentage was about 12·5 %, when the inherent small gluco-corticoid activity of DCA was allowed for. Boiling the adrenal mince inactivated the enzyme responsible. The addition of ascorbic acid had no effect on the conversion reaction.

The incubation of cortisone acetate with adrenal mince led to no alteration in its gluco-corticoid activity.

The incubation of DCA with minced corpus luteum tissue also resulted in an increase of gluco-corticoid activity, but the conversion percentage was only 25 % of that of the adrenal. Incubation with other tissues or plasma showed no significant change.

Biological tests on extracts of fresh non-incubated corpora lutea and placenta revealed no gluco-corticoid activity.

The combined administration of ascorbic acid and DCA to fasted adrenalectomized mice showed no enhancement in glycogen deposition.

The incubation of cholesterol with adrenal tissue did not result in an increase of gluco-corticoid activity.
THE INFLUENCE OF RELAXIN ON MAMMARY GLAND DEVELOPMENT IN GUINEA-PIGS AND RABBITS
Authors: GARRETT FERN A. , TALMAGE R. V.
Published: December 2008

An attempt has been made to determine the influence of relaxin on the early development of the mammary glands in rabbits and guinea-pigs.

Spayed females of both species were treated with α-oestradiol and an extract containing relaxin, after a preliminary course of the steroid alone. In all cases the total treatment was limited to 20 days. Animals given only oestradiol served as controls. While the data presented are insufficient to substantiate without doubt an influence of relaxin per se on the development of the mammary tissue, they indicate that it enhances mammary development. In the guinea-pig this was in the form of a general growth stimulus; in the rabbit it appeared to consist of a transfer of emphasis from primary duct development to that of the entire duct system of the gland.

The conclusion drawn from this study is that relaxin acts as a potentiator of oestrogen, working with the latter to produce greater and more normal development of the mammary glands.
CYCLICAL CHANGES IN THE NUMBER OF MEDIUM AND LARGE FOLLICLES IN THE ADULT RAT OVARY
Authors: MANDL ANITA M. , ZUCKERMAN S.
Published: December 2008

All medium and large follicles were counted and measured in twenty-four pairs of ovaries belonging to rats killed at seven different phases of the oestrous cycle. The follicles were classified into seven size groups, and their frequency distribution determined for the different phases of the cycle.

Follicles with a diameter of 350–449 μ were most numerous at early dioestrus; those with a diameter of 450–549 μ at dioestrus; 550–649 μ at early oestrus, and those measuring more than 650 μ at oestrus. The differences between the peak numbers of follicles in these various size groups and those characterizing other phases of the cycle were in many instances significant at the 2% level.
THE NUMBER OF OOCYTES IN OVARIAN FRAGMENTS AFTER COMPENSATORY HYPERTROPHY
Authors: MANDL ANITA M. , ZUCKERMAN S. , PATTERSON H. D.
Published: December 2008

Fifty-eight female rats belonging to thirteen litters were subjected to the following treatments:

A: right ovary removed; more than half of left ovary resected.

B: right ovary removed; left ovary untreated.

C: same as A, but remaining fragment of left ovary painted with tannic acid in order to destroy the germinal epithelium.

D: right ovary removed; surface of whole left ovary painted with tannic acid.

The animals were killed 50–136 days after operation, and the number of oocytes counted in the whole left ovary or in the parts of the left ovary removed at operation and autopsy. The number of oocytes in the right ovary was estimated in one animal from each litter.

Compensatory hypertrophy occurred in the left ovary or left ovarian fragment, but the number of oocytes did not increase. Tannic acid had no noticeable effect on the numbers of oocytes. The ovarian fragments contained a disproportionately high number of Graafian follicles, and the rate of loss of oocytes appears to increase inversely with the amount of ovarian tissue left in the body.
SOME DIETARY AND HORMONAL EFFECTS ON MATERNAL, FOETAL AND PLACENTAL WEIGHTS IN THE RAT
Authors: CAMPBELL ROSA M. , INNES I. R. , KOSTERLITZ H. W.
Published: December 2008

1. A negative correlation was found between the mean weight of an individual placenta and the number in a litter. Within the range examined and with the methods employed, no definite correlation between the mean weight of an individual foetus and litter size was established.

2. Reduction of the food intake to one-half or one-third during the last 6 days of pregnancy did not result in a decrease in the number and weight of foetuses and placentae. This was apparently brought about by drawing on the maternal reserves laid down during the first 14 days of pregnancy. Absence of protein from the diet during the last 6 days resulted in a very moderate decrease in foetal and placental weights.

3. Absence of the maternal adrenals or pituitary had no influence on foetal and placental weights. The decrease in maternal body weight after hypophysectomy was solely due to loss of appetite and could be prevented by giving the rats adequate amounts of food by stomach tube.

4. The increase in body weight during the first 14 days of pregnancy was maintained after removal of the foetuses as long as the placentae survived. The placentae also had a favourable effect on the maternal body weight in the absence of the foetuses, when the ovaries or adrenals or the pituitary or the pituitary and ovaries were removed, but not when both ovaries and adrenals were absent. The placental factor responsible for this effect appears to act through the ovaries or adrenals.

5. The increase in the weight of the ovaries during pregnancy was not affected by removal of the foetuses, foetuses and pituitary, or foetuses and adrenals. The adrenals of pregnant hypophysectomized rats were not heavier than those of non-pregnant hypophysectomized rats.
OBSERVATIONS ON A METHOD OF MEASURING ADRENOCORTICOTROPHIC HORMONE IN PLASMA
Authors: GRAY C. H. , PARROTT DELPHINE M. V.
Published: December 2008

The recovery by acid acetone of ACTH added to plasma has been investigated. A more rapid and convenient method of extraction of plasma permits recovery of all added ACTH together with ACTH contained in the untreated plasma. It has not been possible to prepare consistently active extracts from whole blood by this method, nor has a quantitative recovery of ACTH added to whole blood been obtained. The results are discussed in relation to those of other workers.
THE ANTIDIURETIC ASSAY OF VASOPRESSIN BY INTRAVENOUS INJECTION INTO UNANAESTHETIZED RATS
Authors: GINSBURG M. , HELLER H.
Published: December 2008

1. A method has been described for the assay of vasopressin by intravenous injection in unanaesthetized rats.

2. The choice of parameters for the expression of antidiuretic responses has been studied in rats and rabbits.

3. It has been shown that the sensitivity of rats to injected vasopressin is independent of the water load within the range of 6–9% of the body weight.
PARALLEL BIOLOGICAL ASSAYS OF THE CORTISONE EQUIVALENT OF THE DOG'S ADRENAL VEIN BLOOD
Authors: BIBILE S. W. , VOGT MARTHE
Published: December 2008

1. The rate of secretion of the adrenal cortex of the anaesthetized dog as measured by the mouse eosinophil test is equivalent to about 11 μg cortisone/g fresh tissue/min.

2. When the cortex of the dog's perfused adrenal is stimulated by ACTH, the increased rate of secretion is registered by the eosinophil test in the same way as by the 'cold test'.

3. When the perfused adrenal was subjected to an increased blood concentration of potassium, only small fluctuations in hormone output were produced. These also were registered by both tests simultaneously.

4. On the assumption that mineralocorticoids are not oxygenated in the C—11 position, these results may be interpreted to mean that, within the experimental errors of the assays, there is no variation in the production of (hypothetical) mineralocorticoids under the conditions of these perfusions.