Time-course changes of nerve growth factor, corticotropin-releasing hormone, and nitric oxide synthase isoforms and their possible role in the development of inflammatory response in experimental allergic encephalomyelitis

In this paper we report a time-course study of development of experimental allergic encephalomyelitis in Lewis rats, by monitoring neuroendocrine regulation of the hypothalamus–pituitary–adrenal axis through corticotropin-releasing hormone mRNA expression, inflammatory cellular infiltrate, macrophagic and neuronal nitric oxide synthase, nerve growth factor (NGF), and NGF p75 and trkA receptors in the brain and spinal cord. We analyzed animals during 20 days after immunization, a time interval that corresponds to the acute immunological phase. We have described a severe, early fall of corticotropin-releasing hormone mRNA expression, which could account for the decreased response of the hypothalamus–pituitary–adrenal axis to inflammatory stress. During this period, an increase of neuronal nitric oxide synthase was observed in the cerebral cortex and spinal cord, and macrophagic nitric oxide synthase positive cells were found in the inflammatory cellular infiltrate, which was abundant in perivascular and submeningeal areas 20 days after immunization. Concomitantly, we found a dramatic up-regulation of NGF receptors on the wall of blood vessels and adjacent neurons in perivascular areas. NGF content also had increased in some brain areas, such as the thalamus, while it had decreased in others, like the spinal cord and medulla oblongata, at time points in which the most serious cellular infiltrate was found.     

Rapid clearance of circulating Leishmania kinetoplast DNA after treatment of visceral leishmaniasis

With the aim of evaluating the utility of the detection of Leishmania kDNA in peripheral blood for the cure assessment of visceral leishmaniasis (VL), a PCR based method was performed in patients with confirmed VL at three follow-up periods after specific chemotherapy with pentavalent antimonial. In 16 out of 17 (94.1%) patients with pre-treatment detectable kDNA that were clinically cured, the PCR turned negative up to 37 days after the initiation of treatment, remaining negative over 90 days after treatment. The clearance of Leishmania kDNA from peripheral blood of patients with VL hints to occur during or shortly after treatment concurring or preceding clinical recovery.     

Transjugular liver biopsy: histological diagnosis success comparing the trucut to the modified aspiration Ross needle

BACKGROUND: Transjugular liver biopsy is an alternative procedure for patients who present contraindications to standard percutaneous procedure. AIM: To compare the rate of histological diagnosis obtained on transjugular liver biopsy with an automated trucut needle and with a modified Ross needle. PATIENTS / METHOD: Eighty-five patients with suspicion of chronic liver diseases and presenting contraindications for percutaneous liver biopsy (coagulopathy, massive ascites, morbid obesity, or chronic renal problems) were submitted to 89 transjugular liver biopsies between March 1994 and April 2001 at "Hospital S?o José, Irmandade da Santa Casa de Misercórdia", Porto Alegre, RS, Brazil. Thirty-five patients underwent 36 biopsies with an automated trucut needle, and 50 patients underwent 53 biopsies with a modified Ross needle. RESULTS: Histological diagnosis was reached in 32/35 subjects submitted to transjugular liver biopsy with the trucut needle (91%) and in 35/50 (70%) submitted to biopsy with the modified Ross needle. Specimens obtained with the trucut needle were significantly larger and less fragmented than those obtained with the Ross needle. CONCLUSION: Transjugular liver biopsy with the automated trucut needle allowed a higher rate of histological diagnosis when compared to the modified Ross needle in patients with suspicion of chronic liver diseases.     

Influence of Esophageal Motility on Esophageal Speech of Laryngectomized Patients

After laryngectomy for treatment of cancer of the larynx, the patient may have vocal rehabilitation by esophageal speech. Some patients fail to achieve the esophageal speech due to reasons involving surgery, radiotherapy, and psychological alterations. Our hypothesis is that the esophageal motility alterations consequent to laryngectomy may be involved in the failure to achieve esophageal speech. Using manometry with continuous perfusion, we studied the esophageal motility of 25 laryngectomized patients, 10 of them able to produce esophageal speech and 15 unable to produce esophageal speech, and 40 asymptomatic normal volunteers. The lower esophageal sphincter (LES) pressure was measured by the rapid pull-through method and the upper esophageal sphincter (UES) pressure by the station pull-through method. The contractions were measured at 5, 10, and 15 cm above the LES after the subjects performed 10 swallows with a 5-mL bolus of water. By comparing volunteers and laryngectomized patients, we found a lower UES pressure, lower amplitude of contractions, and increased percentage of simultaneous contractions in laryngectomized patients (p <0.05). There was no difference between patients able and unable to produce esophageal speech in LES and UES pressure, esophageal contraction duration and velocity, or in the percentage of failed and simultaneous contractions. The esophageal contraction amplitude was lower in patients who acquired esophageal speech than in patients who did not (p <0.05 at 10 cm from LES). We conclude that there are esophageal motility alterations in laryngectomized patients but only the decrease of esophageal contraction amplitude seems to be associated with the acquisition of esophageal speech.     

alpha -galactosylceramide-activated Valpha 14 natural killer T cells mediate protection against murine malaria

Natural killer T (NKT) cells are a unique population of lymphocytes that coexpress a semiinvariant T cell and natural killer cell receptors, which are particularly abundant in the liver. To investigate the possible effect of these cells on the development of the liver stages of malaria parasites, a glycolipid, alpha-galactosylceramide (alpha-GalCer), known to selectively activate Valpha14 NKT cells in the context of CD1d molecules, was administered to sporozoite-inoculated mice. The administration of alpha-GalCer resulted in rapid, strong antimalaria activity, inhibiting the development of the intrahepatocytic stages of the rodent malaria parasites Plasmodium yoelii and Plasmodium berghei. The antimalaria activity mediated by alpha-GalCer is stage-specific, since the course of blood-stage-induced infection was not inhibited by administration of this glycolipid. Furthermore, it was determined that IFN-gamma is essential for the antimalaria activity mediated by the glycolipid. Taken together, our results provide the clear evidence that NKT cells can mediate protection against an intracellular microbial infection.     

The role of leptin in the regulation of TSH secretion in the fed state: in vivo and in vitro studies

Leptin has been shown to stimulate the hypothalamus-pituitary-thyroid axis in fasting rodents; however, its role in thyroid axis regulation under physiological conditions is still under investigation. Here it was investigated in freely fed rats whether leptin modulates thyrotroph function in vivo and whether leptin has direct pituitary effects on TSH release. Since leptin is produced in the pituitary, the possibility was also investigated that leptin may be a local regulator of TSH release. TSH was measured by specific RIA. Freely fed adult rats 2 h after being injected with a single s.c. injection of 8 microg leptin/100 g body weight showed a 2-fold increase in serum TSH (P<0.05). Hemi-pituitary explants incubated with 10(-9) and 10(-7) M leptin for 2 h showed a reduced TSH release of 40 and 50% respectively (P<0.05). Conversely, incubation of hemi-pituitary explants with antiserum against leptin, aiming to block the action of locally produced leptin, resulted in higher TSH release (45%, P<0.05). In conclusion, also in the fed state, leptin has an acute stimulatory effect on TSH release in vivo, acting probably at the hypothalamus. However, the direct pituitary effect of leptin is inhibitory and data also provide evidence that in the rat pituitary leptin may act as an autocrine/paracrine inhibitor of TSH release.     

Dominant or recessive mutations in the RYR1 gene causing central core myopathy in Brazilian patients

Central Core Disease (CCD) is an inherited neuromuscular disorder characterized by the presence of cores in muscle biopsy. CCD is caused by mutations in the RYR1 gene. This gene encodes the ryanodine receptor 1, which is an intracellular calcium release channel from the sarcoplasmic reticulum to the cytosol in response to depolarization of the plasma membrane. Mutations in this gene are also associated with susceptibility to Malignant Hyperthermia (MHS).In this study, we evaluated 20 families with clinical and histological characteristics of CCD to identify primary mutations in patients, for diagnosis and genetic counseling of the families.We identified variants in the RYR1 gene in 19/20 families. The molecular pathogenicity was confirmed in 16 of them. Most of these variants (22/23) are missense and unique in the families. Two variants were recurrent in two different families. We identified six families with biallelic mutations, five compound heterozygotes with no consanguinity, and one homozygous, with consanguineous parents, resulting in 30% of cases with possible autosomal recessive inheritance. We identified seven novel variants, four of them classified as pathogenic. In one family, we identified two mutations in exon 102, segregating in cis, suggesting an additive effect of two mutations in the same allele.This work highlights the importance of using Next-Generation Sequencing technology for the molecular diagnosis of genetic diseases when a very large gene is involved, associated to a broad distribution of the mutations along it. These data also influence the prevention through adequate genetic counseling for the families and cautions against malignant hyperthermia susceptibility.Key words: central core disease, RYR1, Next Generation Sequencing     

Hypoglycemia incidence and awareness among insulin-treated patients with diabetes: the HAT study in Brazil

Background

Hypoglycemia affects patient safety and glycemic control during insulin treatment of both type 1 (T1DM) and type 2 diabetes mellitus (T2DM). The Hypoglycemia Assessment Tool study in Brazil aimed to determine the proportion of patients experiencing hypoglycemic events and to characterize patient awareness and fear about hypoglycemia, among insulin-treated T1DM or T2DM patients.

Methods

This was a non-interventional, multicenter study, with a 6-month retrospective and a 4-week prospective evaluation of hypoglycemic events. Patients completed a questionnaire at baseline and at the end of the study, and also a patient diary. The answers ‘occasionally’ and ‘never’ to the question ‘Do you have symptoms when you have a low sugar level?’ denoted impaired hypoglycemia awareness. Fear was reported on a 10-point scale, from ‘not afraid at all’ to ‘absolutely terrified’.

Results

From 679 included patients, 321 with T1DM and 293 T2DM, median age of 33.0 and 62.0 years, 59% and 56% were female, and median diabetes duration was 15.0 and 15.0 years, respectively. Median time of insulin use was 14.0 and 6.0 years. During the prospective period, 91.7% T1DM and 61.8% T2DM patients had at least one hypoglycemic event. In the same period, 54.0% T1DM and 27.4% T2DM patients had nocturnal hypoglycemia, 20.6% T1DM and 10.6% T2DM patients had asymptomatic hypoglycemia, and severe events occurred in 20.0% and 10.3%, respectively. At baseline, 21.4% T1DM and 34.3% T2DM had hypoglycemia unawareness. The mean score of hypoglycemia fear was 5.9?±?3.1 in T1DM and 5.4?±?3.9 in T2DM. The most common attitude after hypoglycemic events were to increase calorie intake (60.3%) and blood glucose monitoring (58.0%) and to reduce or skip insulin doses (30.8%).

Conclusions

Referred episodes of hypoglycemia were high, in both T1DM and T2DM insulin users. Patient attitudes after hypoglycemia, such as reduction in insulin and increase in calorie intake, can affect diabetes management. These findings may support clinicians in tailoring diabetes education and insulin treatment for patients with diabetes, in order to improve their glycemic control while reducing the risk of hypoglycemic events.

     

De novo T-cell generation in patients at different ages and stages of HIV-1 disease

We assessed de novo T-cell generation by determining T-cell receptor-rearrangement excision circles (TRECs) based on patient age and on stage of HIV-1 infection. TRECs were measured in purified CD4 and CD8 T cells of a large cohort of HIV-1-infected subjects (n = 297) with chronic infection but no previous antiretroviral treatment and of a control group of HIV-negative subjects (n = 120). HIV-1-infected subjects were stratified on the basis of CD4 T-cell counts in 3 groups, early-stage disease (more than 500 CD4 T cells), intermediate-stage disease (200-500 CD4 T cells), and late-stage disease (fewer than 200 CD4 T cells). Compared with the control group, CD8 TREC contents were severely reduced (P <.001) in HIV-1-infected subjects regardless of the stage of HIV disease. In contrast, CD4 TREC contents were significantly increased (P =.003) in HIV-1-infected subjects during early-stage disease, similar at intermediate-stage disease, and severely reduced only at late-stage disease. We show that the increase in CD4 TRECs was mostly limited to younger (younger than 45 years) patients at early-stage disease. Our results demonstrate a dichotomy between TREC contents in CD4 and CD8 T-cell populations in HIV-1 infection and indicate that thymus function in younger subjects is preserved at early and intermediate stages of HIV infection.     

Central hypocortisolism as part of combined pituitary hormone deficiency due to mutations of PROP-1 gene

BACKGROUND: One of the causes of combined pituitary hormone deficiency (CPHD) is represented by Prophet of Pit-1 (PROP-1) gene inactivating mutations. This disorder is generally characterized by GH, TSH, prolactin (PRL), and gonadotropin deficiency, but recent papers have described a concomitant alteration of the corticotrope function. OBJECTIVE: To make a detailed investigation of the hypothalamic-pituitary-adrenal axis in two sisters with PROP-1 gene mutations. PATIENTS: Two female siblings (17 and 16 years old) with CPHD, belonging to a Brazilian family of consanguineous parents, presented with growth retardation and central hypothyroidism during childhood, and showed central hypogonadism at the age of puberty. No clear clinical symptoms and signs of hypocortisolism were present. METHODS: GH, TSH, free thyroxine, total tri-iodothyronine, PRL, LH, FSH, ACTH and cortisol were measured in basal condition and after appropriate testing. The molecular study was performed by PCR amplification and sequencing analysis of PROP-1 gene. RESULTS: Both patients showed GH, PRL, LH and FSH deficiencies, associated with absent responses to an insulin tolerance test (ITT), TRH and GnRH injection. Circulating concentrations of TSH were normal in basal conditions, but failed to respond to a TRH test. Plasma ACTH concentrations were normal, but serum cortisol concentrations were below the lower limit of the normal range, showing a trend to decrease during 6 years of follow-up. The serum ACTH response to ITT was impaired, whereas its response to CRH was normal and prolonged. The cortisol response to both tests, and to the ACTH test, was clearly impaired. In both sisters, the genetic analysis showed the presence of a homozygous 2-bp deletion (296delGA) of PROP-1 gene, which results in the synthesis of a protein with no residual functional activity. CONCLUSION: In addition to GH, TSH, PRL and gonadotropin deficiency, patients with PROP-1 gene mutations can present with late-onset central hypocortisolism, possibly beause of the lack of important paracrine factors normally produced by the cells surrounding the corticotropes and absent in the pituitary of these patients, or because of progressive corticotrope apoptosis. This finding indicates the need for life-long endocrine monitoring of PROP-1-deficient patients.