Abnormal spontaneous interleukin 8 receptor expression: a brief report of two cases

Interleukin 8 (CXCL8) is an autocrine chemokine specific for the chemoattraction and activation of granulocytes, NKT cells and T lymphocytes. Patients with tuberculosis and latent Mycobacterium tuberculosis infection were assessed for the spontaneous expression of CXCR1 (CD128) and CXCR2 on lymphocytes and monocytes. Compared with ex vivo profiles, increased spontaneous CXCR2 expression and normal CXCR1 expression were found on lymphocytes in two out of 59 individuals. Monocytes showed normal ex vivo profiles for both receptors. After stimulation with purified protein derivative, the in vitro levels of CXCL8 were below the median levels of all patients with prior tuberculosis. Spontaneous CXCR2 modulation did not cause notable variation in the in vitro levels of CXCL8.

ABNORMAL SPERMATHECAE NUMBERS IN PERUVIAN SANDFLIES (DIPTERA: PSYSCHODIDAE)

We report and illustrate two abnormal spermatheca numbers found in Peruvian sandflies, a supernumerary spermatheca in Lutzomyia cernerai and the absence of one spermatheca in L. amazonensis.

Obesity does not Lead to Imbalance Between Myocardial Phospholamban Phosphorylation and Dephosphorylation

Background: The activation of the beta-adrenergic system promotes G protein stimulation that, via cyclic adenosine monophosphate (cAMP), alters the structure of protein kinase A (PKA) and leads to phospholamban (PLB) phosphorylation. This protein participates in the system that controls intracellular calcium in muscle cells, and it is the primary regulator of sarcoplasmic reticulum calcium pump activity. In obesity, the beta-adrenergic system is activated by the influence of increased leptin, therefore, resulting in higher myocardial phospholamban phosphorylation via cAMP-PKA. Objective: To investigate the involvement of proteins which regulate the degree of PLB phosphorylation due to beta-adrenergic activation in obesity. In the present study, we hypothesized that there is an imbalance between phospholamban phosphorylation and dephosphorylation, with prevalence of protein phosphorylation. Methods: Male Wistar rats were randomly distributed into two groups: control (n = 14), fed with normocaloric diet; and obese (n = 13), fed with a cycle of four unsaturated high-fat diets. Obesity was determined by the adiposity index, and protein expressions of phosphatase 1 (PP-1), PKA, PLB, phosphorylated phospholamban at serine16 (PPLB-Ser16) were assessed by Western blot. Results: Obesity caused glucose intolerance, hyperinsulinemia, hypertriglyceridemia, hyperleptinemia and did not alter the protein expression of PKA, PP-1, PLB, PPLB-Ser16. Conclusion: Obesity does not promote an imbalance between myocardial PLB phosphorylation and dephosphorylation via beta-adrenergic system.

Abnormal expression of CD54 in mixed reactions of mononuclear cells from hyper-IgE syndrome patients

Hyper-IgE syndrome (HIES) is a rare multisystem disorder characterized by increased susceptibility to infections associated with heterogeneous immunologic and non-immunologic abnormalities. Most patients consistently exhibit defective antigen-induced-T cell activation, that could be partly due to altered costimulation involving accessory molecules; however, the expression of these molecules has never been documented in HIES. Therefore, we investigated the expression of CD11a, CD28, CD40, CD54, CD80, CD86, and CD154 in peripheral blood mononuclear cells from six patients and six healthy controls by flow cytometry after autologous and mixed allogeneic reactions. Only the allogeneic stimuli induced significant proliferative responses and interleukin 2 and interferon gamma production in both groups. Most accessory molecules showed similar expression between patients and controls with the exception of CD54, being expressed at lower levels in HIES patients regardless of the type of stimulus used. Decreased expression of CD54 could partly explain the deficient T cell activation to specific recall antigens in HIES patients, and might be responsible for their higher susceptibility to infections with defined types of microorganisms.

Abnormal humoral immune response to influenza vaccination in pediatric type-1 human immunodeficiency virus infected patients receiving highly active antiretroviral therapy

Given that highly active antiretroviral therapy (HAART) has been demonstrated useful to restore immune competence in type-1 human immunodeficiency virus (HIV-1)-infected subjects, we evaluated the specific antibody response to influenza vaccine in a cohort of HIV-1-infected children on HAART so as to analyze the quality of this immune response in patients under antiretroviral therapy. Sixteen HIV-1-infected children and 10 HIV-1 seronegative controls were immunized with a commercially available trivalent inactivated influenza vaccine containing the strains A/H1N1, A/H3N2, and B. Serum hemagglutinin inhibition (HI) antibody titers were determined for the three viral strains at the time of vaccination and 1 month later. Immunization induced a significantly increased humoral response against the three influenza virus strains in controls, and only against A/H3N2 in HIV-1-infected children. The comparison of post-vaccination HI titers between HIV-1+ patients and HIV-1 negative controls showed significantly higher HI titers against the three strains in controls. In addition, post vaccination protective HI titers (defined as equal to or higher than 1:40) against the strains A/H3N2 and B were observed in a lower proportion of HIV-1+ children than in controls, while a similar proportion of individuals from each group achieved protective HI titers against the A/H1N1 strain. The CD4+ T cell count, CD4/CD8 T cells ratio, and serum viral load were not affected by influenza virus vaccination when pre- vs post-vaccination values were compared. These findings suggest that despite the fact that HAART is efficient in controlling HIV-1 replication and in increasing CD4+ T cell count in HIV-1-infected children, restoration of immune competence and response to cognate antigens remain incomplete, indicating that additional therapeutic strategies are required to achieve a full reconstitution of immune functions.

CagA phosphorylation EPIYA-C motifs and the vacA i genotype in Helicobacter pylori strains of asymptomatic children from a high-risk gastric cancer area in northeastern Brazil

Helicobacter pylori infection is one of the most common infections worldwide and is associated with gastric diseases. Virulence factors such as VacA and CagA have been shown to increase the risk of these diseases. Studies have suggested a causal role of CagA EPIYA-C in gastric carcinogenesis and this factor has been shown to be geographically diverse. We investigated the number of CagA EPIYA motifs and the vacA i genotypes in H. pylori strains from asymptomatic children. We included samples from 40 infected children (18 females and 22 males), extracted DNA directly from the gastric mucus/juice (obtained using the string procedure) and analysed the DNA using polymerase chain reaction and DNA sequencing. The vacA i1 genotype was present in 30 (75%) samples, the i2 allele was present in nine (22.5%) samples and both alleles were present in one (2.5%) sample. The cagA-positive samples showed distinct patterns in the 3’ variable region of cagA and 18 of the 30 (60%) strains contained 1 EPIYA-C motif, whereas 12 (40%) strains contained two EPIYA-C motifs. We confirmed that the studied population was colonised early by the most virulent H. pylori strains, as demonstrated by the high frequency of the vacA i1 allele and the high number of EPIYA-C motifs. Therefore, asymptomatic children from an urban community in Fortaleza in northeastern Brazil are frequently colonised with the most virulent H. pylori strains.

Abnormal meiotic behavior in three species of Crotalaria

The objective of this work was to compare the meiotic behavior and pollen grain viability of three species of Crotalaria. Slides for meiotic analysis were prepared by the air-drying technique. Pollen grain viability was measured by three staining procedures (Alexander's solution, tetrazolium chloride and fluorescein diacetate) and in vitro germination in a sucrose solution. Eight bivalents were observed, confirming previous reports on populations from other regions of Brazil, as well as from other countries. All species showed abnormal meiotic behavior as follows: in Crotalaria micans, cytomixis and abnormal chromosome pairing in diakinesis; in C. spectabilis, abnormal chromosome pairing in diplotene; in C. zanzibarica, shrunk nuclei in leptotene and zygotene. Pollen grains of all three species show low viability, which may be associated with the irregularities of the meiotic behavior.

Radiological findings of uterine arteriovenous malformation: a case report of an unusual and life-threatening cause of abnormal vaginal bleeding

Uterine arteriovenous malformations may cause life-threatening abnormal genital bleeding in women at childbearing age. Transvaginal Doppler ultrasonography is a widely available, noninvasive and excellent diagnostic method. The authors report the case of a patient with history of gestational trophoblastic disease and multiple curettage procedures who developed uterine arteriovenous malformations, with remission of the lesions after treatment with methotrexate.

Abnormal eating behaviors among medical students at a university in southern Santa Catarina, Brazil

OBJECTIVES: Disturbances in eating behavior significantly affect young adults. This study aimed to estimate the prevalence of abnormal eating behaviors, according to the Eating Attitudes Test - 26 (EAT-26) in medical students at a university in southern Santa Catarina State, Brazil. METHODS: Self-reported questionnaire, based on the EAT-26 scale, was administered to medical students. Additional questions about age, gender, study period of the course, weight and height were asked. A total of 391 medical students were assessed, amounting to 93.3 percent of the 419 students enrolled. RESULTS: Ten percent of the surveyed subjects had positive EAT-26 scores. This outcome measure was positive associated with females (PR 6.5), body mass index (BMI) ≤ 25 kg/m² (PR 4.5), age ≤ 20 years (PR 1.3) and being student from 1st to 5th semester of the course (PR 1.7). A higher proportion of women gave positive responses to behaviors related to control of food intake or weight loss than men. CONCLUSION: The significant prevalence of behaviors related to eating disorders, predominantly among women, suggests the implementation of preventive measures targeting this population.

Control of the phosphorylation of the astrocyte marker glial fibrillary acidic protein (GFAP) in the immature rat hippocampus by glutamate and calcium ions: possible key factor in astrocytic plasticity

The present review describes recent research on the regulation by glutamate and Ca2+ of the phosphorylation state of the intermediate filament protein of the astrocytic cytoskeleton, glial fibrillary acidic protein (GFAP), in immature hippocampal slices. The results of this research are discussed against a background of modern knowledge of the functional importance of astrocytes in the brain and of the structure and dynamic properties of intermediate filament proteins. Astrocytes are now recognized as partners with neurons in many aspects of brain function with important roles in neural plasticity. Site-specific phosphorylation of intermediate filament proteins, including GFAP, has been shown to regulate the dynamic equilibrium between the polymerized and depolymerized state of the filaments and to play a fundamental role in mitosis. Glutamate was found to increase the phosphorylation state of GFAP in hippocampal slices from rats in the post-natal age range of 12-16 days in a reaction that was dependent on external Ca2+. The lack of external Ca2+ in the absence of glutamate also increased GFAP phosphorylation to the same extent. These effects of glutamate and Ca2+ were absent in adult hippocampal slices, where the phosphorylation of GFAP was completely Ca2+-dependent. Studies using specific agonists of glutamate receptors showed that the glutamate response was mediated by a G protein-linked group II metabotropic glutamate receptor (mGluR). Since group II mGluRs do not act by liberating Ca2+ from internal stores, it is proposed that activation of the receptor by glutamate inhibits Ca2+ entry into the astrocytes and consequently down-regulates a Ca2+-dependent dephosphorylation cascade regulating the phosphorylation state of GFAP. The functional significance of these results may be related to the narrow developmental window when the glutamate response is present. In the rat brain this window corresponds to the period of massive synaptogenesis during which astrocytes are known to proliferate. Possibly, glutamate liberated from developing synapses during this period may signal an increase in the phosphorylation

Abnormal nocturnal blood pressure fall in normotensive adolescents with insulin-dependent diabetes is ameliorated following glycemic improvement

Lack of the physiological nocturnal fall in blood pressure (BP) has been found in diabetics and it seems to be related to the presence of diabetic complications. The present study examined the changes in the nocturnal BP pattern of 8 normotensive insulin-dependent diabetic adolescents without nephropathy following improvement in glycemic control induced by an 8-day program of adequate diet and exercise. The same number of age- and sex-matched control subjects were studied. During the first and eighth nights of the program, BP was obtained by ambulatory BP monitoring. After a 10-min rest, 3 BP and heart rate (HR) recordings were taken and the mean values were considered to represent their awake values. The monitor was programmed to cuff insufflation every 20 min from 10:00 p.m. to 7:00 a.m. The glycemic control of diabetics improved since glycemia (212.0 ± 91.5 to 140.2 ± 69.1 mg/dl, P<0.03), urine glucose (12.7 ± 11.8 to 8.6 ± 6.4 g/24 h, P = 0.08) and insulin dose (31.1 ± 7.7 to 16.1 ± 9.7 U/day, P<0.01) were reduced on the last day. The mean BP of control subjects markedly decreased during the sleeping hours of night 1 (92.3 ± 6.4 to 78.1 ± 5.0 mmHg, P<0.001) and night 8 (87.3 ± 6.7 to 76.9 ± 3.6 mmHg, P<0.001). Diabetic patients showed a slight decrease in mean BP during the first night. However, the fall in BP during the nocturnal period increased significantly on the eighth night. The average awake-sleep BP variation was significantly higher at the end of the study (4.2 vs 10.3%, P<0.05) and this ratio turned out to be similar to that found in the control group (10.3 vs 16.3%). HR variation also increased on the eighth night in the diabetics. Following the metabolic improvement obtained at the end of the period, the nocturnal BP variation of diabetics was close to the normal pattern. We suggest that amelioration of glycemic control may influence the awake-sleep BP and HR differences. This effect may be due at least in part to an attenuated insulin stimulation of sympathetic activity

Regulation of gap junctions by protein phosphorylation

Gap junctions are constituted by intercellular channels and provide a pathway for transfer of ions and small molecules between adjacent cells of most tissues. The degree of intercellular coupling mediated by gap junctions depends on the number of gap junction channels and their activity may be a function of the state of phosphorylation of connexins, the structural subunit of gap junction channels. Protein phosphorylation has been proposed to control intercellular gap junctional communication at several steps from gene expression to protein degradation, including translational and post-translational modification of connexins (i.e., phosphorylation of the assembled channel acting as a gating mechanism) and assembly into and removal from the plasma membrane. Several connexins contain sites for phosphorylation for more than one protein kinase. These consensus sites vary between connexins and have been preferentially identified in the C-terminus. Changes in intercellular communication mediated by protein phosphorylation are believed to control various physiological tissue and cell functions as well as to be altered under pathological conditions.

Staircase in mammalian muscle without light chain phosphorylation

In disuse atrophied skeletal muscle, the staircase response is virtually absent and light chain phosphorylation does not occur. The purpose of the present study was to determine if staircase could be restored in atrophied muscle with continued absence of myosin light chain phosphorylation, by reducing what appears to be an otherwise enhanced calcium release. Control (untreated) and sham-operated female Sprague-Dawley rats were compared with animals after 2 weeks of complete inactivity induced by tetrodotoxin (TTX) application to the left sciatic nerve. In situ isometric contractile responses of rat gastrocnemius muscle were analyzed before and after administration of dantrolene sodium (DS), a drug which is known to inhibit Ca2+ release in skeletal muscle. Twitch active force (AF) was attenuated by DS from 2.2 ± 0.2 N, 2.7 ± 0.1 N and 2.4 ± 0.2 N to 0.77 ± 0.2 N, 1.05 ± 0.1 N and 1.01 ± 0.2 N in TTX (N = 5), sham (N = 11) and control (N = 7) muscles, respectively. Following dantrolene treatment, 10 s of 10-Hz stimulation increased AF to 1.32 ± 0.2 N, 1.52 ± 0.1 N and 1.45 ± 0.2 N for the TTX, sham and control groups, respectively, demonstrating a positive staircase response. Regulatory light chain (R-LC) phosphorylation was lower for TTX-treated (5.5 ± 5.5%) than for control (26.1 ± 5.3%) and sham (20.0 ± 5%) groups. There was no significant change from resting levels for any of the groups after DS treatment (P = 0.88). This study shows that treatment with dantrolene permits staircase in atrophied muscle as well as control muscle, by a mechanism which appears to be independent of R-LC phosphorylation.

Retinol-induced changes in the phosphorylation levels of histones and high mobility group proteins from Sertoli cells

Chromatin proteins play a role in the organization and functions of DNA. Covalent modifications of nuclear proteins modulate their interactions with DNA sequences and are probably one of the multiple factors involved in the process of switch on/off transcriptionally active regions of DNA. Histones and high mobility group proteins (HMG) are subject to many covalent modifications that may modulate their capacity to bind to DNA. We investigated the changes induced in the phosphorylation pattern of cultured Wistar rat Sertoli cell histones and high mobility group protein subfamilies exposed to 7 µM retinol for up to 48 h. In each experiment, 6 h before the end of the retinol treatment each culture flask received 370 KBq/ml [32P]-phosphate. The histone and HMGs were isolated as previously described [Moreira et al. Medical Science Research (1994) 22: 783-784]. The total protein obtained by either method was quantified and electrophoresed as described by Spiker [Analytical Biochemistry (1980) 108: 263-265]. The gels were stained with Coomassie brilliant blue R-250 and the stained bands were cut and dissolved in 0.5 ml 30% H2O2 at 60oC for 12 h. The vials were chilled and 5.0 ml scintillation liquid was added. The radioactivity in each vial was determined with a liquid scintillation counter. Retinol treatment significantly changed the pattern of each subfamily of histone and high mobility group proteins.

Abnormal proliferative response of the carotid artery of spontaneously hypertensive rats after angioplasty may be related to the depolarized state of its smooth muscle cells

Hypertension is one of the major precursors of atherosclerotic vascular disease, and vascular smooth muscle abnormal cell replication is a key feature of plaque formation. The present study was conducted to examine the relationship between hypertension and smooth muscle cell proliferation after balloon injury and to correlate neointima formation with resting membrane potential of uninjured smooth muscle cells, since it has been suggested that altered vascular function in hypertension may be related to the resetting of the resting membrane potential in spontaneously hypertensive rats (SHR). Neointima formation was induced by balloon injury to the carotid arteries of SHR and renovascular hypertensive rats (1K-1C), as well as in their normotensive controls, i.e., Wistar Kyoto (WKY) and normal Wistar (NWR) rats. After 14 days the animals were killed and the carotid arteries were submitted to histomorphometric and immunohistochemical analyses. Resting membrane potential measurements showed that uninjured carotid arteries from SHR smooth muscle cells were significantly depolarized (-46.5 ± 1.9 mV) compared to NWR (-69 ± 1.4 mV), NWR 1K-1C (-60.8 ± 1.6 mV), WKY (-67.1 ± 3.2 mV) and WKY 1K-1C (-56.9 ± 1.2 mV). The SHR arteries responded to balloon injury with an enhanced neointima formation (neo/media = 3.97 ± 0.86) when compared to arteries of all the other groups (NWR 0.93 ± 0.65, NWR 1K-1C 1.24 ± 0.45, WKY 1.22 ± 0.32, WKY 1K-1C 1.15 ± 0.74). Our results indicate that the increased fibroproliferative response observed in SHR is not related to the hypertensive state but could be associated with the resetting of the carotid smooth muscle cell resting membrane potential to a more depolarized state.