Hormonal and cardiovascular reflex assessment in a female patient with pure autonomic failure

We report the case of a 72-year-old female with pure autonomic failure, a rare entity, whose diagnosis of autonomic dysfunction was determined with a series of complementary tests. For approximately 2 years, the patient has been experiencing dizziness and a tendency to fall, a significant weight loss, generalized weakness, dysphagia, intestinal constipation, blurred vision, dry mouth, and changes in her voice. She underwent clinical assessment and laboratory tests (biochemical tests, chest X-ray, digestive endoscopy, colonoscopy, chest computed tomography, abdomen and pelvis computed tomography, abdominal ultrasound, and ambulatory blood pressure monitoring). Measurements of catecholamine and plasmatic renin activity were performed at rest and after physical exercise. Finally the patient underwent physiological and pharmacological autonomic tests that better diagnosed dysautonomia.

Effect of hormonal changes on corneal biomechanical properties and anterior segment ocular perameters

Dissertação de mestrado em Optometria Avançada

Perfil neuro-hormonal de pacientes reumáticos com insuficiência aórtica crônica importante

FUNDAMENTO: Os neuro-hormônios estão envolvidos na fisiopatologia da insuficiência cardíaca, mas pouco se sabe sobre seu comportamento na insuficiência aórtica crônica importante (IAo). OBJETIVO: Analisar o comportamento desses mediadores na IAo. MÉTODOS: Analisamos 89 pacientes com IAo, com média etária de 33,6±11,5 anos, 84,6% do sexo masculino, 60% assintomáticos, todos de etiologia reumática. Após avaliação clínica e ecocardiográfica, realizaram-se dosagens plasmáticas de fator de necrose tumoral (TNF), seus antagonistas receptores solúveis tipos I e II (sTNFRI e sTNFRII), interleucina-6 (IL-6), seu receptor solúvel, endotelina-1 e peptídeo natriurético tipo B (BNP). Doze indivíduos saudáveis serviram como controle. RESULTADOS: O valor médio de diâmetro diastólico (DD) do ventrículo esquerdo (VE) foi de 71,9±8,3 mm, e o do diâmetro sistólico (DS) do VE, de 50,4±9,3 mm. Os níveis de neuro-hormônios estavam elevados nos pacientes com IAo: TNF 92,65±110,24 pg/ml vs. 1,67±1,21 pg/ml nos controles, p<0,001; IL-6 7,17±7,78 pg/ml vs. 0,81±0,38 pg/ml nos controles, p = 0,0001; e TNFRI 894,75±348,87 pg/ml vs. 521,42±395,13 pg/ml, p = 0,007. Com exceção dos níveis de BNP, os pacientes sintomáticos e assintomáticos apresentaram perfil neuro-hormonal semelhante. Houve correlação entre TNFRII e diâmetro diastólico do ventrículo esquerdo (DDVE) (r = -0,329, p = 0,038) e diâmetro sistólico do ventrículo esquerdo (DSVE) (r = -0,352, p = 0,027). Os níveis de BNP estavam significativamente mais altos em pacientes sintomáticos, e apenas nestes foi possível correlação entre BNP e diâmetros ventriculares. CONCLUSÃO: Pacientes com insuficiência aórtica crônica importante apresentam altos níveis neuro-hormônios, sem correlação com o status sintomático. Os níveis de TNFRII e BNP puderam ser correlacionados com diâmetros ventriculares, mas apenas este último com sintomas.

Contracepção hormonal e sistema cardiovascular

A contracepção hormonal é o método mais utilizado para prevenção de gestações não planejadas. A literatura tem demonstrado associação entre risco cardiovascular e uso de hormonioterapia. A fim de melhorar a orientação contraceptiva para mulheres com fatores de risco para doença cardiovascular, realizamos uma revisão da literatura em relação ao assunto. Esta revisão descreve os dados mais recentes da literatura científica acerca da influência dos contraceptivos hormonais em relação a trombose venosa, arterial e hipertensão arterial sistêmica, doenças cada dia mais prevalentes na população feminina jovem.

Postnatal maternal separation affects hippocampal longterm potentiation in adult stressed rats : molecular and hormonal mechanisms

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2013

Inputs to the hormonal control of egg development in Rhodnius prolixus

This paper re-examines existing data on the environmental inputs governing egg production in Rhodnius prolixus. Feeding has a direct effect on egg production such that the product of the unfed weight of the female times the weight of the blood meal is a good predictor of the number of eggs produced. Mating modifies this input, so that mated females produce more eggs. Egg production is governed by the corpus allatum, and indirect evidence suggests that the number of eggs producted by a female is a function of the length of time that juvenile hormone is secreted by the corpus allatum. The input which determines the times at which the corpus allatum is switched off originates in the stretch induced by the amount of the meal remaining in the crop, modified by the matedness status of the female. The precise nature of the sensors detecting stretch is not yet clear, but the integrity of the dorsal aorta is essential to the transmission of the information. These data are related to the survival strategy for Rhodnius.

A hormonal regulatory module that provides flexibility to tropic responses.

Plants orient their growth depending on directional stimuli such as light and gravity, in a process known as tropic response. Tropisms result from asymmetrical accumulation of auxin across the responding organ relative to the direction of the stimulus, which causes differential growth rates on both sides of the organ. Here, we show that gibberellins (GAs) attenuate the gravitropic reorientation of stimulated hypocotyls of dark-grown Arabidopsis (Arabidopsis thaliana) seedlings. We show that the modulation occurs through induction of the expression of the negative regulator of auxin signaling INDOLE-3-ACETIC ACID INDUCIBLE19/MASSUGU2. The biological significance of this regulatory mechanism involving GAs and auxin seems to be the maintenance of a high degree of flexibility in tropic responses. This notion is further supported by observations that GA-deficient seedlings showed a much lower variance in the response to gravity compared to wild-type seedlings and that the attenuation of gravitropism by GAs resulted in an increased phototropic response. This suggests that the interplay between auxin and GAs may be particularly important for plant orientation under competing tropic stimuli.

Biomorphological Alterations Induced by an Anti-juvenile Hormonal Compound, 2-(2-EthoxyEthoxy)Ethyl Furfuryl Ether, on Three Species of Triatominae Larvae (Hemiptera, Reduviidae)

Applied topically to larvae of Rhodnius prolixus Stal, Triatoma infestans (Klug) and Panstrongylus herreri Wygodzinsky, vectors of Trypanosoma cruzi, the causative agent of Chagas'disease, a synthetic, furan-containing anti-juvenile hormonal compound, 2-(2-ethoxyethoxy)ethyl furfuryl ether induced a variety of biomorphological alterations, including precocious metamorphosis into small adultoids with adult abdominal cuticle, ocelli, as well as rudimentary adultoid wings. Some adultoids died during ecdysis and were confined within the old cuticle. The extension of these biomorphological responses is discussed in terms of the complexity of the action of anti-juvenile hormonal compounds during the development of triatomines

Breast stem cells and hormonal mechanisms in carcinogenesis

A woman's risk of breast cancer is strongly affected by her reproductive history. The hormonal milieu is also a key determinant of the course of the disease. Combining mouse genetics with tissue recombination techniques, we have established that the female reproductive hormones, estrogens, progesterone, and prolactin, act sequentially on the mammary epithelium to trigger distinct developmental steps. The hormones impinge directly on a subset of luminal mammary epithelial cells that express the respective hormone receptors and act as sensor cells translating and amplifying systemic signals into local stimuli. Local signaling is stage and age specific. During puberty, estrogens promote proliferation using the EGF family member, amphiregulin, as essential paracrine mediator. In adulthood, progesterone, rather than estrogen, is the major inducer of stem cell activation and cell proliferation of the mammary epithelium. Hormonal signaling modulates crucial developmental pathways that impinge on mammary stem cell populations, while Notch signaling, by inhibiting p63, is central to mammary cell fate determination. Cell proliferation occurs in two waves. The first results from direct stimulation of the small fraction of hormone receptor positive cells. It is followed by a second wave of progesterone-induced proliferation involving mostly hormone receptor negative cells, in which RANKL is a key mediator. A model in which repeated activation of paracrine signaling by progesterone with resulting stem cell activation promotes breast carcinogenesis is proposed.

Effects of the peroxisome proliferator-activated receptor (PPAR)-gamma agonist pioglitazone on renal and hormonal responses to salt in diabetic and hypertensive individuals.

Aims/Hypothesis: Glitazones are powerful insulin sensitisers prescribed for the treatment of type 2 diabetes. Their use is, however, associated with fluid retention and an increased risk of congestive heart failure. We previously demonstrated that pioglitazone increases proximal sodium reabsorption in healthy volunteers. This study examines the effects of pioglitazone on renal sodium handling in individuals prone to insulin resistance, i.e. those with diabetes and/or hypertension. Methods: In this double-blind randomised placebo-controlled four-way crossover study, we examined the effects of pioglitazone (45 mg daily during 6 weeks) or placebo on renal, systemic and hormonal responses to changes in sodium intake in 16 individuals, eight with type 2 diabetes and eight with hypertension. Results: Pioglitazone was associated with a rapid increase in body weight and an increase in diurnal proximal sodium reabsorption, without any change in renal haemodynamics or in the modulation of the renin-angiotensin aldosterone system to changes in salt intake. A compensatory increase in brain natriuretic peptide levels was observed. In spite of sodium retention, pioglitazone dissociated the blood-pressure response to salt and abolished salt sensitivity in salt-sensitive individuals. Conclusions/Interpretation: Pioglitazone increases diurnal proximal sodium retention in diabetic and hypertensive individuals. These effects cause fluid retention and may contribute to the increased incidence of congestive heart failure with glitazones.

Renal and hormonal responses to direct renin inhibition with aliskiren in healthy humans.

BACKGROUND: Pharmacological interruption of the renin-angiotensin system focuses on optimization of blockade. As a measure of intrarenal renin activity, we have examined renal plasma flow (RPF) responses in a standardized protocol. Compared with responses with angiotensin-converting enzyme inhibition (rise in RPF approximately 95 mL x min(-1) x 1.73 m(-2)), greater renal vasodilation with angiotensin receptor blockers (approximately 145 mL x min(-1) x 1.73 m(-2)) suggested more effective blockade. We predicted that blockade with the direct oral renin inhibitor aliskiren would produce renal vascular responses exceeding those induced by angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. METHODS AND RESULTS: Twenty healthy normotensive subjects were studied on a low-sodium (10 mmol/d) diet, receiving separate escalating doses of aliskiren. Six additional subjects received captopril 25 mg as a low-sodium comparison and also received aliskiren on a high-sodium (200 mmol/d) diet. RPF was measured by clearance of para-aminohippurate. Aliskiren induced a remarkable dose-related renal vasodilation in low-sodium balance. The RPF response was maximal at the 600-mg dose (197+/-27 mL x min(-1) x 1.73 m(-2)) and exceeded responses to captopril (92+/-20 mL x min(-1) x 1.73 m(-2); P<0.01). Furthermore, significant residual vasodilation was observed 48 hours after each dose (P<0.01). The RPF response on a high-sodium diet was also higher than expected (47+/-17 mL x min(-1) x 1.73 m(-2)). Plasma renin activity and angiotensin levels were reduced in a dose-related manner. As another functional index of the effect of aliskiren, we found significant natriuresis on both diets. CONCLUSIONS: Renal vasodilation in healthy people with the potent renin inhibitor aliskiren exceeded responses seen previously with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. The effects were longer lasting and were associated with significant natriuresis. These results indicate that aliskiren may provide more complete and thus more effective blockade of the renin-angiotensin system.