Myo1g is required for efficient adhesion and migration of activated B lymphocytes to inguinal lymph nodes.

Cell migration is a dynamic process that involves adhesion molecules and the deformation of the moving cell that depends on cytoskeletal remodeling and actin-modulating proteins such as myosins. In this work, we analyzed the role of the class I Myosin-1 g (Myo1g) in migratory processes of LPS + IL-4 activated B lymphocytes in vivo and in vitro. In vivo, the absence of Myo1g reduced homing of activated B lymphocytes into the inguinal lymph node. Using microchannel chambers and morphology analysis, we found that the lack of Myo1g caused adhesion and chemotaxis defects. Additionally, deficiency in Myo1g causes flaws in adopting a migratory morphology. Our results highlight the importance of Myo1g during B cell migration.

Population pharmacokinetics of albendazole in patients with neurocysticercosis.

OBJECTIVES: To determine a population pharmacokinetic model of the antihelmintic drug, albendazole, and identify the factors influencing the pharmacokinetic parameters in patients with neurocysticercosis. METHODS: A prospective study was performed in 90 patients receiving 30 mg/kg/day of albendazole for 8 days. Blood samples were collected at steady state. Plasma concentrations of albendazole sulfoxide, the main active metabolite of albendazole, were determined by HPLC. The population pharmacokinetics analysis was performed using non-linear mixed-effect modeling (NONMEM). A one-compartment model with first order absorption and elimination was used. RESULTS: Body weight was included empirically on CL/F and V/F using an allometric relationship. Although none of the investigated covariates had a significant influence on the pharmacokinetic parameters of albendazole, the final model identified two subpopulations on the bioavailability parameter. One subpopulation comprising of 27% of the total population had a bioavailability of 28%, with the remaining subpopulation defined to have complete bioavailability. The CL/F and V/F for a standard 70 kg individual was determined to be 51.6 l/h and 4560 l, respectively. Interindividual variability in CL/F was 32%; the residual unexplained variability was 32%. CONCLUSIONS: The considerable variability reported in albendazole pharmacokinetics and plasma concentrations is likely due to issues related to bioavailability. With one-fourth of the population absorbing as little as 30% of the drug relative to others, low drug exposures might be responsible for treatment failures. Therapeutic drug monitoring may be warranted to optimize the eradication of the infecting parasite.

Time-dependent pharmacokinetics of cyclosporine (Neoral) in de novo renal transplant patients.

PURPOSE: A model for the large scale temporal trend in the oral bioavailability of microemulsion cyclosporine (Neoral) (CsA) is established, with dependence on post-(renal) transplantation day (PTD). METHODS: Twenty de novo adult renal transplant recipients were monitored for CsA administered orally q12 h. A model development group (11 patients, 315 blood concentration samples) was screened at 2 h (C(2); n = 92), 3 h (C(3); n = 56) and at predose troughs (C(min); n = 167) over periods of up to 75 days. The final model was tested in nine patients with C(min) (n = 580) monitored across 4-5 years. The doses varied between 100 and 538 mg with an apparent hyperbolic trend in C(2)/dose vs. PTD. A nonlinear mixed effects modelling (NONMEM) approach was used to obtain population and individual patient one-compartment pharmacokinetic (PK) parameters for oral CsA, which carry implicit the bioavailability (F). RESULTS: In the final PK model (PK-f) the F was modelled via a simple function for the temporal (days) trend of the bioavailability after transplantation as, F(f) = 1-alpha * exp(-lambda * PTD) resulting in a 28% reduction in the unexplained intra-individual variability. The population PK-f parameters were, for apparent clearance [mean, 95% confidence interval (interindividual CV%)] Cl/F(f) = 17.0 (13.8-20.2) L/h (27%), apparent central compartment volume of distribution, V/F(f) = 134 L (108-160) (28%), and lambda = 0.037/day (0.005-0.069) (120%). The absorption rate k(a) and the parameter alpha were approximated iteratively as 4/h and 0.62 respectively. The PK-f was structurally superior to the base model in explaining part of the within subject (occasion) variability and predicting the exposure surrogates C(2) and C(3). Also, the PK-f was better than the base model with Bayesian fitting of individual profiles in that group. CONCLUSION: The PTD-dependent relative bioavailability model provides a rational means of steering dose titration of CsA in de novo renal transplantation patients by removing the large scale PK adjustment signal, either through nomograms or as a Bayesian prior.

Anafilaxia inducida por ejercicio en un pinar / Anafilaxy induced by physical exercise in a pine grove

Introducción: El término anafilaxia hace referencia a una reacción alérgica generalizada, casi siempre como resultado de un mecanismo de hipersensibilidad tipo I, dependiente de IgE. Dentro de las causas más frecuentes de anafilaxia recurrente se encuentran entre otras el ejercicio, con o sin asociación a determinados alimentos. Se presenta el caso de una reacción anafiláctica en una paciente que realizaba ejercicio físico en un pinar. Método: se estudió, mediante prueba cutánea de prick y detección de IgE específica por immunoblotting frente a la procesionaria del pino, una vez que se sospechó que podía ser el alergeno implicado y una vez descartado el ejercicio y los alimentos como sospechosos de la reacción alérgica. Resultados: la prueba cutánea y la detección de IgE fue positiva para el extracto de oruga. En el immunoblotting se detectaron bandas reactivas entre 70-22 kDa. Conclusiones: se trataba de una reacción anafiláctica, mediada por IgE frente a la procesionaria del pino (AU)

Lipid effects, effectiveness and acceptability of tibolone versus transdermic 17 beta-estradiol for hormonal replacement therapy in women with surgical menopause.

OBJECTIVE: To compare the effectiveness of tibolone and 17 beta-estradiol on climacteric symptoms, lipid and biochemical parameters in women with surgical menopause. METHODS: In a prospective randomised clinical trial group comparative study, the effects on the aforementioned parameters, as well as treatment compliance and side effects were studied with oral tibolone 2.5 mg per day and with transdermic 17 beta-estradiol at 50 microg per day for a period of 12 months. Statistical analysis was carried out using the Fisher-test, analysis of the variance (ANOVA) for the two factors and the Bouferoni test. RESULTS: Lipid metabolism analysis showed lower levels of HDL and triglycerides in the tibolone group. Other biochemical parameters were not affected. Similar reductions in climacteric symptoms were found in both the groups, but the tibolone group revealed a greater improvement in psychological problems and in sexual behaviour. No differences were observed with respect to compliance and side effects. CONCLUSIONS: Tibolone is as effective or more than 17 beta-estradiol in reducing climacteric symptoms, and shows greater triglyceride and total cholesterol improvements. Tibolone is a good alternative to estrogens in women with surgical menopause.

Successful pregnancy in a woman with acromegaly treated with somatostatin analog (octreotide) prior to surgical resection.

A 27-year-old woman with a GH-secreting pituitary macroadenoma was treated with continuous s.c. infusion of octreotide prior to surgical resection. Subsequently, she was found to be 6 months pregnant. Fetal echographs were normal, the newborn had no malformation, and postnatal development was normal.

Generation of polyclonal antibodies of predetermined specificity against pediocin PA-1.

Polyclonal antibodies of predetermined specificity for pediocin PA-1 (pedA1) have been generated by immunization of rabbits with a chemically synthesized C-terminal fragment of this bacteriocin (PH2) conjugated to the carrier protein keyhole limpet hemocyanin (KLH). The sensitivity and specificity of the PH2-KLH-generated antibodies were evaluated by the development of various enzyme-linked immunosorbent assays (ELISAs)-a noncompetitive indirect ELISA (NCI-ELISA), a competitive indirect ELISA (CI-ELISA), and a competitive direct ELISA (CD-ELISA)-and by immunodotting. All immunoassays indicated the existence of pedA1-specific antibodies with high relative affinities and adequate sensitivities in the sera of immunized animals. The limits of detection of pedA1 in MRS medium (Oxoid Ltd., Basingstoke, United Kingdom) were found to be 2.5 microg/ml by immunodotting and 1 microg/ml in the NCI-ELISA. However, the CI-ELISA enhanced the limit of detection of pedA1 to 0.025 microg/ml, while the amount of free pedA1 required for 50% binding inhibition was 10 microg/ml. Moreover, the CD-ELISA increased the affinity of the PH2-KLH-generated antibodies for pedA1; the limit of detection of pedA1 was less than 0.025 microg/ml, and the 50% binding inhibition value was reduced to 0.5 microg of pedA1/ml. All immunoassays and the slot dot assay detected the presence of pedA1 in the supernatant of the producing strain Pediococcus acidilactici 347, with no reactivity or negligible immunoreactivity with the supernatants of other lactic acid bacteria producing or not producing different bacteriocins. The approaches taken for the generation of antibodies and the development of immunoassays could prove useful for the generation and evaluation of antibodies of predetermined specificity for other bacteriocins of interest in the food industry.

One-step purification of nisin A by immunoaffinity chromatography.

The lantibiotic nisin A was purified to homogeneity by a single-step immunoaffinity chromatography method. An immunoadsorption matrix was developed by direct binding of anti-nisin A monoclonal antibodies to N-hydroxysuccinimide-activated Sepharose. The purification procedure was rapid and reproducible and rendered much higher final yields of nisin than any other described method.

Research note: unsuitability of the MRS medium for the screening of hydrogen peroxide-producing lactic acid bacteria.

The effect of MRS broth on the stability of hydrogen peroxide (H2O2) has been studied. Known concentrations (1-100 micrograms ml-1) of H2O2 were prepared in distilled water, phosphate buffer (pH 7.0) and MRS broth (pH 6.2 and 3.9). H2O2 was very stable in aqueous and buffer solutions but it was rapidly degraded in MRS broth (pH 3.9). The presence of H2O2 in MRS broth (pH 6.2) could not be detected.

[Comparative study of normal and over-users of a health center]. / Estudio comparativo entre población normo e hiperfrecuentadora en un centro de salud.

OBJECTIVE: To compare normal users (NU) and over-users (OU), examining social and demographic features, family characteristics, presence of psychological problems or family dysfunction and the existence of chronic pathologies. DESIGN: An observational crossover study, lasting one year (1994). SETTING: Health centre. PATIENTS AND OTHER PARTICIPANTS: Randomised sampling of 12,092 patients > 14 years old. OU (n = 260) was defined as someone who had a percentage point for attendance without an appointment at the Centre, excluding bureaucratic reasons, of above 75%; and NU (n = 260), in the 25 and 75% band. 65 individuals (240 OU and 225 NU) took part. MEASUREMENTS AND MAIN RESULTS: Average age of OU was higher than that of NU. 88 OU (36.7%) finished their education above primary level, whereas 115 NU (51.1%) did so (OR 1.81). 37.5% OU (90) belonged to small families, against 24.9% NU (56). 34.6% OU (83) were in an advanced family vital cycle, against 24% NU (54. 26.7% OU (64) and 17.8% NU (40) had psychological problems. There was family dysfunction in 32 OU (13.3%) and 23% NU (10.2%). 186 OU (77.5%) had some chronic pathology, against 96 NU, of whom 70.3% OU and 87.2% NU attended appointments arranged to monitor these pathologies. CONCLUSIONS: Over-use of our health centre is related to being older, a low level of education, belonging to small families in an advanced vital cycle, having psychological problems, suffering chronic pathologies and not attending appointments when they are arranged.

Generation of polyclonal antibodies against nisin: immunization strategies and immunoassay development.

Murine polyclonal antibodies reactive to the lantibiotic bacteriocin nisin A (nisA) have been produced by immunization with nisA-cholera toxin and nisA-keyhole limpet hemocyanin (nisA-KLH) conjugates. Mice immunized with nisA-cholera toxin developed nisA-specific antibodies with low relative affinities and poor sensitivities, while the immunization of mice with nisA-KLH conjugates resulted in the production of nisA-specific antibodies with high relative affinities and much-increased sensitivities. nisA antibodies could also be readily mass produced in less than 8 weeks in ascites fluid by using the nisA-KLH conjugate. A competitive direct enzyme-linked immunosorbent assay (ELISA) whereby nisA-horseradish peroxidase and free nisA competed for antibody binding was devised. The detection limit for nisA in the competitive direct ELISA with the nisA-KLH-generated antibodies was from 5 to 100 ng/ml, while the amount of free nisA required for 50% antibody binding inhibition ranged from 0.3 to 5 micrograms /ml. Both antisera and ascites polyclonal antibodies cross-reacted with nisZ either in the supernatant of a producer strain or with the pure lantibiotic but did not cross-react at all with non-lantibiotic-type bacteriocins. These polyclonal antibodies should find a wide usage from nisA ELISA analysis in foods and other matrices.

Detección de rotavirus no-A en Tucumán / Detection of non-A rotavirus in Tucumán

Se informa un caso de gastroenteritis infecciosa (GEI) causada por un Rotavirus (RV) no-A en la provincia de Tucumán. La muestra de materia fecal resultó negativa en la prueba de enzimoinmunoensayo (ELISA) para RV del grupo A y por electroforesis en gel de poliacrilamida del RNA viral presentó un bandeo genómico coincidente con el descripto por Pedley para los RV clasificados en el grupo C. Esta sería la primera comunicación sobre detección de RV no-A causante de GEI humana en la República Argentina (AU)

Detección de rotavirus no-A en Tucumán / Detection of non-A rotavirus in Tucumán

Se informa un caso de gastroenteritis infecciosa (GEI) causada por un Rotavirus (RV) no-A en la provincia de Tucumán. La muestra de materia fecal resultó negativa en la prueba de enzimoinmunoensayo (ELISA) para RV del grupo A y por electroforesis en gel de poliacrilamida del RNA viral presentó un bandeo genómico coincidente con el descripto por Pedley para los RV clasificados en el grupo C. Esta sería la primera comunicación sobre detección de RV no-A causante de GEI humana en la República Argentina

[Detection of non-A rotavirus in Tucumán]. / Detección de rotavirus no-A en Tucumán.

A case of infectious gastroenteritis (GEI) caused by a non-A Rotavirus (RV) in the province of Tucumán is reported. Fecal sample analysis for group A RV by enzyme immunoassay (ELISA) gave a negative result. Polyacrylamide gel electrophoresis (PAGE) of the viral RNA showed a genomic pattern coincident with that described by Pedley for RV belonging to group C. To our knowledge, this is the first communication on the detection of non-A RV as an etiological agent of human GEI in Argentina.

Detección de rotavirus no-A en Tucumán. / [Detection of non-A rotavirus in Tucumán]

A case of infectious gastroenteritis (GEI) caused by a non-A Rotavirus (RV) in the province of Tucumán is reported. Fecal sample analysis for group A RV by enzyme immunoassay (ELISA) gave a negative result. Polyacrylamide gel electrophoresis (PAGE) of the viral RNA showed a genomic pattern coincident with that described by Pedley for RV belonging to group C. To our knowledge, this is the first communication on the detection of non-A RV as an etiological agent of human GEI in Argentina.

[Electrophoretic types of rotavirus RNA during a 4-yr study of gastroenteritis in Tucumán]. / Electroferotipos del ARN de rotavirus durante cuatro años de estudio de gastroenteritis en Tucumán.

Between May 1986 and November 1989 a total of 796 faecal samples obtained from children with symptoms of acute diarrhea were analyzed. Rotavirus (RV) was detected in 166 cases by polyacrylamide gel electrophoresis of the viral RNA (PAGE) (Fig. 1). This technique allowed us to identify 19 different electropherotypes (EPT) eleven with a long pattern and 8 with a short one (Fig. 2). Two EPT's were dominant during this study; one detected in 1986 only and the other one in 1987, 1988 and 1989. During the last months of 1989 a new EPT was detected. The 8 EPT's with short patterns were the causative organisms of an outbreak during the cold season of 1987 (Table 2). These results show that the rotaviral infection is endemic in the province of Tucumán, as well as its prevalence during the winter season (Table 1).

Electroferotipos del ARN de rotavirus durante cuatro años de estudio de gastroenteritis en Tucumán. / [Electrophoretic types of rotavirus RNA during a 4-yr study of gastroenteritis in Tucumán]

Between May 1986 and November 1989 a total of 796 faecal samples obtained from children with symptoms of acute diarrhea were analyzed. Rotavirus (RV) was detected in 166 cases by polyacrylamide gel electrophoresis of the viral RNA (PAGE) (Fig. 1). This technique allowed us to identify 19 different electropherotypes (EPT) eleven with a long pattern and 8 with a short one (Fig. 2). Two EPTs were dominant during this study; one detected in 1986 only and the other one in 1987, 1988 and 1989. During the last months of 1989 a new EPT was detected. The 8 EPTs with short patterns were the causative organisms of an outbreak during the cold season of 1987 (Table 2). These results show that the rotaviral infection is endemic in the province of Tucumán, as well as its prevalence during the winter season (Table 1).

Platelet activation and secretion associated with emotional stress.

Platelets are believed to play a role in the pathogenesis of atherosclerosis and of the vascular obstruction that causes the acute complications of coronary artery disease. Since specific behavioral patterns appear to be related to the development of coronary artery disease and since emotional stress may predispose an individual to acute cardiovascular ischemia, it was hypothesized that platelet activation by catecholamines might be involved in these events. To study emotional stress, plasma samples were obtained from 61 senior medical residents immediately before they were to speak in public. There were significant increases in the plasma concentrations of the platelet-secreted proteins platelet factor 4 and beta-thromboglobulin and epinephrine and norepinephrine immediately before speaking, which demonstrates that platelet activation and secretion occur in association with this type of emotional stress. Four trials were carried out to study the mechanism for this observed platelet secretion: (1) phenoxybenzamine, (2) propranolol, (3) 650 mg aspirin, and (4) 80 mg aspirin were given several hours before the public speaking engagement. Neither phenoxybenzamine nor propranolol in doses that blocked the hemodynamic effects of alpha 1- and beta 1-adrenergic stimulation modified platelet secretion. Aspirin also did not block platelet secretion, which suggests that platelets were not being stimulated through a cyclooxygenase-dependent pathway. This study provides direct evidence of platelet secretion in vivo in association with emotional stress, and underscores the potential importance of platelet activation and secretion in the acute events that occur in patients with vascular disease.