B-Cell Responses in Chronic Chagas Disease: Waning of Trypanosoma cruzi-Specific Antibody-Secreting Cells Following Successful Etiological Treatment.

BACKGROUND: A drawback in the treatment of chronic Chagas disease (American trypanosomiasis) is the long time required to achieve complete loss of serological reactivity, the standard for determining treatment efficacy. METHODS: Antibody-secreting cells and memory B cells specific for Trypanosoma cruzi and their degree of differentiation were evaluated in adult and pediatric study participants with chronic Chagas disease before and after etiological treatment. RESULTS: T. cruzi-specific antibody-secreting cells disappeared from the circulation in benznidazole or nifurtimox-treated participants with declining parasite-specific antibody levels after treatment, whereas B cells in most participants with unaltered antibody levels were low before treatment and did not change after treatment. The timing of the decay in parasite-specific antibody-secreting B cells was similar to that in parasite-specific antibodies, as measured by a Luminex-based assay, but preceded the decay in antibody levels detected by conventional serology. The phenotype of total B cells returned to a noninfection profile after successful treatment. CONCLUSIONS: T. cruzi-specific antibodies in the circulation of chronically T. cruzi-infected study participants likely derive from both antigen-driven plasmablasts, which disappear after successful treatment, and long-lived plasma cells, which persist and account for the low frequency and long course to complete seronegative conversion in successfully treated participants.

Perturbed T cell IL-7 receptor signaling in chronic Chagas disease.

We have previously demonstrated that immune responses in subjects with chronic Trypanosoma cruzi infection display features common to other persistent infections with signs of T cell exhaustion. Alterations in cytokine receptor signal transduction have emerged as one of the cell-intrinsic mechanisms of T cell exhaustion. In this study, we performed an analysis of the expression of IL-7R components (CD127 and CD132) on CD4(+) and CD8(+) T cells and evaluated IL-7-dependent signaling events in patients at different clinical stages of chronic chagasic heart disease. Subjects with no signs of cardiac disease showed a decrease in CD127(+)CD132(+) cells and a reciprocal gain of CD127(-)CD132(+) in CD8(+) and CD4(+) T cells compared with either patients exhibiting heart enlargement or uninfected controls. T. cruzi infection, in vitro, was able to stimulate the downregulation of CD127 and the upregulation of CD132 on T cells. IL-7-induced phosphorylation of STAT5 as well as Bcl-2 and CD25 expression were lower in T. cruzi-infected subjects compared with uninfected controls. The serum levels of IL-7 were also increased in chronic chagasic patients. The present study highlights perturbed IL-7/IL-7R T cell signaling through STAT5 as a potential mechanism of T cell exhaustion in chronic T. cruzi infection.

Sequential combined treatment with allopurinol and benznidazole in the chronic phase of Trypanosoma cruzi infection: a pilot study.

OBJECTIVES: Even though the use of combined drugs has been proved to be effective in other chronic infections, assessment of combined treatment of antiparasitic drugs in human Chagas' disease has not been performed. Herein, a pilot study was conducted to evaluate the tolerance and side effects of a sequential combined treatment of two antiparasitic drugs, allopurinol and benznidazole, in the chronic phase of Trypanosoma cruzi infection. PATIENTS AND METHODS: Changes in total and T. cruzi-specific T and B cells were monitored during a median follow-up of 36 months. Allopurinol was administered for 3 months (600 mg/day) followed by 30 days of benznidazole (5 mg/kg/day) in 11 T. cruzi-infected subjects. RESULTS: The combined sequential treatment of allopurinol and benznidazole was well tolerated. The levels of T. cruzi-specific antibodies significantly decreased after sequential combined treatment, as determined by conventional serology and by a multiplex assay using recombinant proteins. The frequency of T. cruzi-specific interferon-γ-producing T cells significantly increased after allopurinol treatment and decreased to background levels following benznidazole administration in a substantial proportion of subjects evaluated. The levels of total naive (CD45RA + CCR7 + CD62L+) CD4 + and CD8 + T cells were restored after allopurinol administration and maintained after completion of the combined drug protocol, along with a decrease in T cell activation in total peripheral CD4 + and CD8 + T cells. CONCLUSIONS: This pilot study shows that the combination of allopurinol and benznidazole induces significant modifications in T and B cell responses indicative of a reduction in parasite burden, and sustains the feasibility of administration of two antiparasitic drugs in the chronic phase of Chagas' disease.

Influence of exogenous insulin on C-peptide levels in subjects with type 2 diabetes.

AIM: The aim of this study was to determine whether the influence of insulin therapy on fasting and stimulated C-peptide levels in type 2 diabetic subjects is due to plasma glucose reduction or a direct effect of exogenous insulin. METHODS: Plasma glucose and serum C-peptide levels were determined before and after IV injection of 1mg glucagon on three separate days in 21 type 2 diabetic subjects. Day 1: without pharmacological treatment and fasting plasma glucose > 11.1 mmol/L; day 2: fasting plasma glucose 4.4-7.8 mmol/L, 1h after withdrawing intravenous regular insulin infusion; day 3: fasting plasma glucose 4.4-7.8 mmol/L with bed-time NPH insulin. RESULTS: Fasting and glucagon stimulated C-peptide levels were higher on day 1 than days 2 and 3. Fasting, but not stimulated C-peptide levels, were lower on day 3 than day 2. These differences were not appeared when the percentage of C-peptide increment or the C-peptide/glucose ratio were compared in the three days. CONCLUSIONS: Blood glucose reduction instead of exogenous insulin is responsible for the C-peptide decrease during insulin therapy in type 2 diabetic subjects.

Postpartum thyroiditis in women with hypothyroidism antedating pregnancy?

In women with hypothyroidism, levothyroxine (LT) requirements after delivery are assumed to return to prepregnancy values. The occasional observation of discordances prompted this study. Forty-one women (31 receiving LT replacement therapy and 10 receiving suppressive therapy for thyroid carcinoma) were followed during the first year after delivery. A control group of 31 nonpregnant women with hypothyroidism (n = 21) or thyroid carcinoma (n = 10) were also followed during a similar period. Twenty-three patients of 41 (56.1%) had discordant requirements at follow-up after delivery vs. 3 of 31 in the control group (9.7%; P < 0.001). The patterns of discordance in the postdelivery group were hyperthyroidism in 12, increase in LT dose in 5, hyper- and hypothyroidism in 5, and recurrence of Graves' disease in 1 women. Those in the control group were increase in LT dose, hyperthyroidism, and hypo- and hyperthyroidism. The rate of patients with discordant prepregnancy-postpartum LT doses was higher in the noncarcinoma subgroup (67.7% vs. 20.0%; P < 0.01), whereas in the control group, both subgroups displayed a similar rate of discordance (9.5% vs. 10%; P = NS). In conclusion, this study documents that women with hypothyroidism antedating pregnancy display changes in LT requirements in the first year after delivery that suggest postpartum thyroiditis.

Clinical forms of presentation and evolution of diffuse sclerosing variant of papillary carcinoma and insular variant of follicular carcinoma of the thyroid.

We investigated whether the diffuse sclerosing variant of papillary carcinoma (diffuse sclerosing PC) and insular carcinoma (IC), two different subforms of differentiated carcinoma of the thyroid gland, have different clinical behaviors and prognosis in order to select appropriate therapy. The characteristics of clinical presentation, and outcome after therapy were evaluated in a series of 113 patients (18 males and 95 females) with differentiated thyroid carcinoma treated with the same protocol, of which 7 had diffuse sclerosing PC and 6 had IC; within this series, patients with diffuse sclerosing PC and IC were compared with 76 cases of papillary carcinoma (PC) and 24 cases of follicular carcinoma (FC), respectively. Diffuse sclerosing PC patients were younger (23+/-9 vs. 38+/-16 years) and had a higher degree of lymphatic metastases at diagnosis (100%) than patients with PC (47%). Five of 7 patients with diffuse sclerosing PC were alive and without evidence of disease compared to 34 of 76 patients with PC at follow-up (6.4+/-5.1 and 7.9+/-7 years, respectively). No prognostic differences were found between them. IC showed a more advanced stage of disease at diagnosis and a more aggressive clinical course with a higher percent of metastases and mortality than patients with FC at follow-up (1 patient died and 5 were alive with persistent disease at 4.8+/-3.7 years for IC; 22 were alive, 13 of them with persistent disease; and 2 died at 8.4+/-5.3 years for FC). We conclude that patients with diffuse sclerosing PC do not require a different treatment than that given to PC patients, while in contrast, IC cases need a more aggressive therapeutic approach.

Biochemical liver abnormalities in Turner's syndrome.

BACKGROUND: Turner's syndrome is a chromosomal abnormality (45X0) which may be associated with various autoimmune disorders and disease conditions; however, association with liver pathology has rarely been reported. OBJECTIVES: The aim of this work was to assess liver function abnormalities in a group of adult patients with Turner's syndrome. DESIGN AND METHODS: Liver function tests were performed in 16 women with Turner's syndrome all of whom had been previously treated with oestrogens. Patients with liver abnormalities were further studied with hepatic ultrasonography, serological markers of viral hepatitis and autoantibody determinations. RESULTS: Seven women (43.7%) presented with asymptomatic liver cholestasis; these patients were older than those with normal biochemical values (33.4+/-5.2 vs 24.7+/-5.7 years, P<0.05). Liver function abnormalities appeared 7.8+/-4.9 years after starting oestrogen therapy; however, no improvement of liver function was observed 20+/-17.7 months after stopping treatment. All of these women were anti-HCV and HBsAg negative, and autoimmune hepatitis was ruled out in all cases. Liver ultrasound only disclosed homogeneous liver enlargement in one case and cholelithiasis without bile duct abnormalities in another. Four patients underwent a percutaneous liver biopsy of which two were normal and two showed minimal non-specific changes. CONCLUSIONS: The incidence of biochemical liver cholestasis in this group of patients with Turner's syndrome is high. Oestrogen therapy and autoimmune disorders do not seem to be the responsible causes. It appears that this is a benign condition which does not seem to reflect any substantial liver dysfunction. The aetiology remains uncertain.

Reproducibility of diabetes mellitus diagnosis (WHO 1999 criteria) in women.

Reproducibility of diabetes mellitus (DM) diagnosis has been recognized as non-optimal and a few studies have analyzed its reproducibility using new diagnostic criteria. Our aim was to evaluate the reproducibility of WHO 1999 criteria for DM diagnosis in women. A total of 696 caucasian women with previous gestational diabetes mellitus (GDM) underwent an OGTT at a median of 6.2 years (interquartile range, 0.5-7.3) after delivery. When OGTT was diagnostic of DM, a second test was scheduled and performed after a median of 3 months (interquartile range, 1.6-10.6). At the second test, 35 women were diagnosed with DM (12 by fasting plasma glucose (FPG) alone, 10 by isolated post-challenge hyperglycemia (IPH), 10 by fasting and 2-h plasma glucose, 3 by symptoms of hyperglycemia plus measurement of plasma glucose). DM was confirmed in 56.3% of women diagnosed without symptoms. In this subgroup, reproducibility according to the abnormality at the first test was: 33.3% in those diagnosed by FPG alone, 40% in those diagnosed by IPH, and 100% in those diagnosed by both fasting and 2-h plasma glucose ( p<0.05 vs. the two previous groups). In women with former GDM, the reproducibility of DM diagnosis by FPG alone or IPH is similar and lower than the diagnosis made by abnormality in both values.

Upper airway obstruction in patients with endothoracic goiter enlargement: no relationship between flow-volume loops and radiological tests.

BACKGROUND: In about 16-85% of subjects with goiter, upper airway obstruction (UAO) is observed. This percentage is higher in patients affected by goiter with endothoracic enlargement. UAO is an indication for surgery. Visual analysis of flow-volume loops (FVL) are the best indicators for UAO, although various studies using clinical and radiological parameters have observed no correlation. OBJECTIVE: To evaluate the presence of UAO in patients with endothoracic goiter enlargement and the relationship between the FVL with the observed symptoms and the measurements obtained by computed tomography (CT). SUBJECTS: Subjects with endothoracic goiter enlargement participated in the study. DESIGN: i) Symptom questionnaire (dysphagia, dyspnea, cough, oppression, dysphonia, and worsened symptoms when prone); ii) analysis: TSH and free thyroxine; iii) cervical ultrasound; iv) cervical-thoracic CT (measurements of area and diameter in the area of maximum stenosis and at 2 cm from the carina); v) chest radiography and vi) forced spirometry: visual analysis of FVL morphology and the maximum forced expiratory volume in 1 s (FEV(1)), forced expiratory flow at 50% vital capacity/forced inspiratory flow at 50% vital capacity and FEV(1)/peak expiratory flow parameters. RESULTS: Fifty subjects participated in the study: 11 men/39 women, median age 73.8 years (43.76-88.43). UAO was diagnosed in 13 cases (26%, confidence interval: 14.6-40.3%) and 27 subjects (54%) presented symptoms suggesting goiter compression. No clinical or radiological variables showed the presence of UAO. CONCLUSIONS: The frequency of UAO in subjects affected by goiter with endothoracic enlargement was lower than that described for goiter patients, and there were no clinical or radiological indicators to establish its presence.

Reversible impairment of renal function associated with enalapril in a diabetic patient.

Acute renal failure and hyperkalemia due to angiotensin-converting enzyme inhibitors have been described in diabetic patients with other predisposing conditions. The case reported here involves a patient with type 1 diabetes mellitus, microalbuminuria and normal renal function who was treated with enalapril. Two years after initiation of this therapy, at a time when glycemic control was poor, he presented with symptomatic hyperkalemia and impaired renal function accompanied by hyporeninemic hypoaldosteronism. This case illustrates that reversible impairment of renal function and hyperkalemia can present after 2 years of treatment with angiotensin-converting enzyme inhibitors in patients with precipitating factors.

[Risk factors in child asthma]. / Factores de riesgo en el asma infantil.

OBJECTIVE: To evaluate six risk factors in a population of low economic level. MATERIAL AND METHOD: 40 asthmatic children were studied, 21 masculine and 19 feminine, with a 9.3 years old half age +/- 3.22 years. A group control is included (22 children) without asthma and without allergic symptoms. RESULTS: I intragroup study. In the control group the tobacco atmosphere overcame the prospective frequency (p < 0.05), circumstance that didn't happen to the group of patient. Intragroup studies. There were not significant differences among the parameters studied in both groups, except for the frequency of family antecedents. CONCLUSIONS: The genetic factor is decisive for the initial asthma. The genotypic studies has found the chromosomic locus that regulate their expression. The environmental factors, particularly the tobacco pre and postnatal, they are decisive in the early precipitation of the beginning of the asthma.

Assessment of insulin sensitivity and beta-cell function from measurements in the fasting state and during an oral glucose tolerance test.

AIMS/HYPOTHESIS: We aimed to find if the relation between insulin sensitivity and beta-cell function assessed from fasting and OGTT measurements has a physiological shape (hyperbolic with the reference methods). METHODS: Healthy women without diabetic first-degree relatives underwent a 75 g OGTT with plasma glucose and insulin (n = 35) concentrations being measured at 0, 30, 60 and 120 min. Beta-cell function and insulin sensitivity were estimated using previously described indices from fasting (1 for beta-cell function, 6 for insulin sensitivity) and OGTT measurements (3 for beta-cell function and 5 for insulin sensitivity). A hyperbolic relation was tested for the 21 beta-cell function-insulin sensitivity pairs using a non-lineal regression method. RESULTS: The assessment of beta-cell function from OGTT was impossible in seven women and one had outlier indices. For the remaining 27 women, only 8 combinations adjusted to a hyperbolic relation. The best adjustment was achieved using the fasting glucose to insulin ratio as the estimation of insulin sensitivity and the homeostasis model assessment (HOMA) index (single fasting sample) as the estimation of beta-cell function (r2 0.802, k 869.71, p < 0.001). CONCLUSION/INTERPRETATION: In this group of healthy women, the estimation of insulin sensitivity and beta-cell function by most methods using OGTT-derived glucose and insulin measurements did not adjust to a hyperbolic relation but all fasting indices combinations did. Beta-cell function estimated with the HOMA index and insulin sensitivity with fasting glucose to insulin ratio had the best adjustment.

Survival of several Rhizobium/Bradyrhizobium strains on different inoculant formulations and inoculated seeds.

The effect of a variety factors on the survival of several rhizobia strains on inoculants and inoculated seeds has been evaluated. Since the rhizobia strains showed different cell-density-evolution patterns on peat-based inoculants and on inoculated seeds, several inoculant formulations with highly effective Rhizobium/Bradyrhizobium strains (for Lupinus, Hedysarum, Phaseolus and Glycine max.) were monitored under the following storage conditions: (a) the inoculants were kept refrigerated (at 4 degrees C), or (b) at room temperature (25 degrees C). The effect of water content (30-50%, w/w) in the inoculants as well as that of several seed-coating adhesives were also investigated. Alternative carriers including perlite and vermiculite were tested. For all of the strains, survival on sterile peat-based inoculants was higher than on the corresponding unsterile peat formulation; for the latter, refrigerated storage conditions are recommended to ensure high bacterial densities. The water content of the inoculants had a differential effect on strain survival depending on the sterility of the peat, such that a high water content was more detrimental when unsterilized peat was employed. The best adherent for rhizobia survival was a gum arabic/water solution. Perlite was as effective as peat in maintaining a high population of rhizobia, at least for 6 months of storage.

Acromegaly Quality of Life Questionnaire (ACROQOL) a new health-related quality of life questionnaire for patients with acromegaly: development and psychometric properties.

OBJECTIVE: To develop a disease-specific questionnaire suitable to measure health-related quality of life (HRQOL) in acromegaly (ACROQOL). DESIGN, PATIENTS AND MEASUREMENTS: For the development of the ACROQOL questionnaire different sources of information were used: First, a literature search was performed to identify relevant papers describing the impact of acromegaly in HRQOL. Second, 10 endocrinologists identified the main domains of impact on HRQOL in patients with acromegaly. Third, 10 in-depth, semistructured interviews were conducted in acromegalic patients to identify domains and items related to the self-perceived impact of acromegaly in patients' life. Qualitative analyses of the information were performed identifying domains and items to be included in the questionnaire. Those items considered ambiguous, complicated to read, double-barrelled, with jargon terms, too long, or negatively worded were excluded. Each remaining item was subsequently rated by the same panel of endocrinologists and experts in HRQOL evaluation, and assessed according to clarity of wording, frequency of occurrence and importance among patients with acromegaly. Analysis of internal consistency of the questionnaire was evaluated with a Cronbach's Alpha. A preliminary questionnaire was administered to 72 patients with acromegaly. Rasch analysis (dichotomous logistic response model) of the answers given by these patients allowed parameter estimates and model data fit indices to be computed and misfitting items deleted. Frequency of occurrence and degree of agreement with the statements were selected as response choices in a 5-point Likert type scale. RESULTS: The following domains related to HRQOL in acromegaly were identified: physical and psychological functions, social, daily activities, symptoms, cognition, general health perception, sleep, sexual function, pain, energy and body image. An initial set of 204 expressions were identified from the initial transcripts of the patient interviews. After elimination of ambiguous or unclear expressions, 142 items remained drafted in question form. From the quantitative analysis of the item rank position within each of the three areas of clarity, frequency and importance, the 38-item questionnaire was produced, with satisfactory internal consistency (Cronbach's Alpha 0.94). Rasch analysis produced a further reduction to the final 22-item questionnaire (Cronbach's Alpha 0.91) containing two scales that evaluate physical (eight questions) and psychological aspects related to appearance and personal relations (seven items each). The evaluation of the item parameters confirmed the construct validity of the new instrument. The substantial reliability of the questionnaire suggested the sample was well targeted by the questionnaire. The initial Spanish version was translated into English and presented to five English-speaking Australian patients with acromegaly to assess and correct for comprehension, clarity, cultural relevance and suitable wording. CONCLUSIONS: We present the ACROQOL questionnaire, developed and preliminarily validated to specifically assess HRQOL in patients with acromegaly.