Influence of glucocorticoids on the somatotrophic axis

GH secretion is modulated by a complex interplay between two hypothalamic factors, GHRH (growth hormone-releasing hormone) and somatostatin (SRIF). More recently, a third physiological mechanism mediated by GHS (growth hormone secretagogues) and its endogenous counterpart, ghrelin, has been discovered. Glucocorticoids (GCs) influence GH secretion acting at several levels, although the mechanisms involved in its multiple actions are not fully elucidated. Moreover, these steroids have stimulatory or inhibitory effects on GH release depending on the experimental model, duration of exposure, dose, type and route of administration, among other factors. Although controversial, acute GCs administration enhances GH secretion in man. However, when given for longer periods (months or years), it inhibits GH release. The effects of these steroids on IGF-1 and IGFBPs are quite controversial.A secreção de hormônio de crescimento (growth hormone, GH) é modulada por uma interação complexa entre dois fatores hipotalâmicos: o hormônio liberador do GH (GH-releasing hormone, GHRH) e a somatostatina (SRIF). Recentemente foi sugerida a existência de uma terceira via fisiológica de regulação deste hormônio, mediada pelos GHS (growth hormone secretagogues) e provavelmente pelo peptídeo endógeno, ghrelina. Os glicocorticóides (GCs) influenciam a secreção de GH atuando em diversos níveis, apesar dos mecanismos envolvidos nessas múltiplas ações não estarem totalmente elucidados. Além disso, esses esteróides têm efeitos estimulatórios ou inibitórios na liberação de GH, dependendo do modelo experimental, duração da exposição, dose, tipo e via de administração, entre outros. Embora controvertida, a administração aguda de GCs aumenta a secreção de GH em humanos. No entanto, quando presente em níveis suprafisiológicos por períodos mais longos (meses ou anos), os GCs inibem a liberação de GH. O efeito desses esteróides na IGF-1 e IGFBPs são bastante controvertidos.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP) Setor de NeuroendocrinologiaUNIFESP, Setor de NeuroendocrinologiaSciEL

Uso da solução hipertônica de cloreto de sódio a 7,5% no tratamento da hipotensão arterial decorrente da anestesia com halotano em eqüinos

Solução hipertônica de cloreto de sódio a 7,5% tem sido utilizada no tratamento do choque hipovolêmico. Sua ação é caracterizada pelo aumento do débito cardíaco, da pressão arterial sistêmica e do volume plasmático. O objetivo deste estudo foi avaliar a ação da solução hipertônica de cloreto de sódio a 7,5% (4 ml/kg) no tratamento da hipotensão arterial induzida pela anestesia geral com halotano em eqüinos. Foram utilizados 15 eqüinos adultos, de ambos os sexos e raças e pesos variados, encaminhados a processos cirúrgicos eletivos. A técnica anestésica constituiu-se de sedação com detomidina, indução anestésica com éter gliceril guaiacol, midazolam e quetamina e manutenção anestésica com halotano em oxigênio. Estabeleceu-se como valor mínimo para infusão de solução hipertônica de cloreto de sódio a 7,5%, pressão arterial média inferior a 60 mmHg. Foram avaliados os seguintes parâmetros: freqüência e ritmo cardíacos; pressão arterial sistólica, diastólica e média; freqüência respiratória; tempo de preenchimento capilar; gases sangüíneos, pH arterial, bicarbonato plasmático; saturação da oxi-hemoglobina; concentração plasmática de sódio e cloreto e hematócrito. Considerou-se o tempo zero como controle e os parâmetros foram aferidos aos 5, 15, 30 e 60 minutos após a infusão. Verificou-se aumento significativo dos valores da pressão arterial, a qual manteve-se elevada durante o período de observação. Os valores do hematócrito diminuíram significativamente demonstrando ter havido expansão volêmica. Houve discreta hipernatremia e hipercloremia. Os demais parâmetros permaneceram inalterados. Pode-se concluir que a solução hipertônica de cloreto de sódio a 7,5% mostrou-se efetiva, podendo ser utilizada com segurança nos processos hipotensivos desencadeados pelaanestesia geral com halotano.7.5% sodium chloride hypertonic solution is widely employed to improve hemodynamic parameters mainly treatment of hemorrhagic shock. Its action is characterized by an increment of cardiac output, systemic blood pressure and plasmatic volume. The aim of this study was the evaluation of 7.5% sodium chloride hypertonic solution in the treatment of hypotension due to general anesthesia with halothane in horses. Fifteen adult horses of different breeds and weights submitted to electivesurgeries were allocated in this trial.The animals received detomidine as premedication. Induction of anesthesia was performed with guaifenesin, midazolam and ketamine. Halothane in 100% oxygen was used as the maintenance agent. When the mean arterial blood pressure fell below 60 mmHg, 4 ml/kg of 7.5% sodium chloride hypertonic solution were administered intravenously. Heart rate and rhythm, systolic, mean and diastolic blood pressure, respiratory rate, capillary refill time, blood gases, arterial pH, bicarbonate, oxyhaemoglobin saturation, sodium and chloride plasma levels, as well as packed cell volume were evaluated after 5,15, 30 and 60 minutes hypertonic infusion. A significant increase of arterial blood pressure was verified after hypertonic administration. Values of blood pressure remained above control during all the recording period. Packed cell volume decreased significantly showing the improvement of plasmatic volume caused by this solution. Discrete hypernatremia and hyperchloremia were observed. The other parameters remained unaltered. We can conclude that 7.5% sodium chloride hypertonic solution is effective and may be employed in the treatment of hypotension during halothane anesthesia in equines

Brazilian multicenter study on pegvisomant treatment in acromegaly

Objective Investigate the therapeutic response of acromegaly patients to pegvisomant (PEGV) in a real-life, Brazilian multicenter study. Subjects and methods Characteristics of acromegaly patients treated with PEGV were reviewed at diagnosis, just before and during treatment. All patients with at least two IGF-I measurements on PEGV were included. Efficacy was defined as any normal IGF-I measurement during treatment. Safety data were reviewed. Predictors of response were determined by comparing controlled versus uncontrolled patients. Results 109 patients [61 women; median age at diagnosis 34 years; 95.3% macroadenomas] from 10 Brazilian centers were studied. Previous treatment included surgery (89%), radiotherapy (34%), somatostatin receptor ligands (99%), and cabergoline (67%). Before PEGV, median levels of GH, IGF-I and IGF-I % of upper limit of normal were 4.3 µg/L, 613 ng/mL, and 209%, respectively. Pre-diabetes/diabetes was present in 48.6% and tumor remnant in 71% of patients. Initial dose was 10 mg/day in all except 4 cases, maximum dose was 30 mg/day, and median exposure time was 30.5 months. PEGV was used as monotherapy in 11% of cases. Normal IGF-I levels was obtained in 74.1% of patients. Glycemic control improved in 56.6% of patients with pre-diabetes/diabetes. Exposure time, pre-treatment GH and IGF-I levels were predictors of response. Tumor enlargement occurred in 6.5% and elevation of liver enzymes in 9.2%. PEGV was discontinued in 6 patients and 3 deaths unrelated to the drug were reported. Conclusions In a real-life scenario, PEGV is a highly effective and safe treatment for acromegaly patients not controlled with other therapies

Zika virus infection among symptomatic patients from two healthcare centers in Sao Paulo State, Brazil: prevalence, clinical characteristics, viral detection in body fluids and serodynamics.

Zika virus (ZIKV) clinical presentation and frequency/duration of shedding need further clarification. Symptomatic ZIKV-infected individuals identified in two hospitals in Sao Paulo State, Brazil, were investigated regarding clinical characteristics, shedding in body fluids, and serodynamics. Ninety-four of 235 symptomatic patients (Site A: 58%; Site B: 16%) had Real-Time PCR-confirmed ZIKV infection; fever, headache and gastrointestinal symptoms were less frequent, and rash was more frequent compared to ZIKV-negative patients. Real-Time PCR in serum had worse performance compared to plasma, while urine had the highest sensitivity. Shedding in genital fluids and saliva was rare. IgM positivity was the highest 28 days (24%); IgG positivity increased >14 days (96%) remaining positive in 94% of patients >28 days. ZIKV prevalence varied importantly in two neighboring cities during the same transmission season. Urine Real-Time PCR can improve diagnostic sensitivity; serum testing is less useful. Accurate serological tests are needed to improve diagnosis and surveillance

Zika virus infection among symptomatic patients from two healthcare centers in Sao Paulo State, Brazil: prevalence, clinical characteristics, viral detection in body fluids and serodynamics

Zika virus (ZIKV) clinical presentation and frequency/duration of shedding need further clarification. Symptomatic ZIKV-infected individuals identified in two hospitals in Sao Paulo State, Brazil, were investigated regarding clinical characteristics, shedding in body fluids, and serodynamics. Ninety-four of 235 symptomatic patients (Site A: 58%; Site B: 16%) had Real-Time PCR-confirmed ZIKV infection; fever, headache and gastrointestinal symptoms were less frequent, and rash was more frequent compared to ZIKV-negative patients. Real-Time PCR in serum had worse performance compared to plasma, while urine had the highest sensitivity. Shedding in genital fluids and saliva was rare. IgM positivity was the highest <14 days after the symptoms onset (86%), decreasing >28 days (24%); IgG positivity increased >14 days (96%) remaining positive in 94% of patients >28 days. ZIKV prevalence varied importantly in two neighboring cities during the same transmission season. Urine Real-Time PCR can improve diagnostic sensitivity; serum testing is less useful. Accurate serological tests are needed to improve diagnosis and surveillance

Clinical features and natural history of the first 2073 suspected COVID-19 cases in the Corona São Caetano primary care programme: a prospective cohort study.

BACKGROUND: Despite most cases not requiring hospital care, there are limited community-based clinical data on COVID-19. METHODS: The Corona São Caetano programme is a primary care initiative providing care to all residents with COVID-19 in São Caetano do Sul, Brazil. It was designed to capture standardised clinical data on community COVID-19 cases. After triage of potentially severe cases, consecutive patients presenting to a multimedia screening platform between 13 April and 13 May 2020 were tested at home with SARS-CoV-2 reverse transcriptase (RT) PCR; positive patients were followed up for 14 days with phone calls every 2 days. RT-PCR-negative patients were offered additional SARS-CoV-2 serology testing to establish their infection status. We describe the clinical, virological and natural history features of this prospective population-based cohort. FINDINGS: Of 2073 suspected COVID-19 cases, 1583 (76.4%) were tested by RT-PCR, of whom 444 (28.0%, 95% CI 25.9 to 30.3) were positive; 604/1136 (53%) RT-PCR-negative patients underwent serology, of whom 52 (8.6%) tested SARS-CoV-2 seropositive. The most common symptoms of confirmed COVID-19 were cough, fatigue, myalgia and headache; whereas self-reported fever (OR 3.0, 95% CI 2.4 to 3.9), anosmia (OR 3.3, 95% CI 2.6 to 4.4) and ageusia (OR 2.9, 95% CI 2.3 to 3.8) were most strongly associated with a positive COVID-19 diagnosis by RT-PCR or serology. RT-PCR cycle thresholds were lower in men, older patients, those with fever and arthralgia and closer to symptom onset. The rates of hospitalisation and death among 444 RT-PCR-positive cases were 6.7% and 0.7%, respectively, with older age and obesity more frequent in the hospitalised group. CONCLUSION: COVID-19 presents in a similar way to other mild community-acquired respiratory diseases, but the presence of fever, anosmia and ageusia can assist the specific diagnosis. Most patients recovered without requiring hospitalisation with a low fatality rate compared with other hospital-based studies

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio