Effect of fluoride on salivary immunoglobulins and sialic acid

Summary Objective: The aim of our study was to evaluate the effect of fluoride on salivary immunoglobulin and sialic acid levels in children with dental fluorosis and healthy teeth who live in places with high fluoride concentration in drinking water. Method: Fifty-one (51) healthy children between 6 and 12 years old with no caries were randomly selected from primary schools enrolled in the dental-care program operated by the Department of Pediatric Dentistry. The children were divided into two groups: group I comprised 26 children with dental fluorosis [Thylstrup-Fejerskov Dental Fluorosis Index (TFI) = 4] who lived in Isparta (2.7-2.8 ppm), and group II consisted of 25 children without dental fluorosis who were born in low-fluoride areas and had lived in Isparta for only the previous two years. Stimulated and unstimulated saliva were collected and analyzed for fluoride, salivary immunoglobulins and sialic acid levels. Results: Sialic acid level was correlated negatively with age. Levels of secretory immunoglobulin A (sIgA) and secretory immunoglobulin G (sIgG) were higher in children with dental fluorosis compared with those in group II, although these differences were not significant. Conclusion: Increased sIgA and sIgG levels may arrest the progression of caries in subjects with dental fluorosis. Given the risks of dental fluorosis, further studies of the effects of different fluoride levels in drinking water on salivary composition of children with mixed dentition are needed to confirm the results of our study and to provide data for comparison.

Effect of biotherapeutics on antitoxin IgG in experimentally induced Clostridium difficile infection.

Purpose: Recurrent diarrhoea after successful treatment of primary Clostridium difficile associated disease (CDAD) occurs due to bowel flora alterations and failure to mount an effective antibody response. Apart from antibiotics, risk factors include immunosuppressive and acid-suppressive drug administration. Biotherapeutics such as probiotic and epidermal growth factor (EGF) may offer potential effective therapy for CDAD. Materials and Methods: The effect of biotherapeutics in mounting an antibody response against C. difficile toxins was studied in BALB/c mice challenged with C. difficile after pre-treatment with ampicillin, lansoprazole or cyclosporin. Sera from sacrificed animals were estimated for antitoxin IgG by enzyme linked immunosorbent assay. Results: Antitoxin IgG was significantly higher (P<0.05) in C. difficile challenged groups compared to unchallenged controls, but insignificant (P>0.05) in animals in which C. difficile was given after pre-treatment with cyclosporin compared to those without any pre-treatment, or pre-treatment with antibiotic or lansoprazole. In inter-subgroup comparisons also significant anomaly in production of antitoxin IgG was found. The antitoxin IgG levels were raised in animals administered C. difficile after pre-treatment with ampicillin, but lower in animals administered cyclosporin. High levels of antitoxin IgG were also found in the serum samples of animals receiving lansoprazole and C. difficile. Conclusions: Probiotics showed their beneficial effect by boosting the immune response as seen by production of antitoxin IgG. Oral administration of EGF did not affect the immune response to C. difficile toxins as significant increase was not observed in the serum antitoxin IgG levels in any of the groups investigated.

Effect of anti-epileptic drugs on serum level of IgG subclasses

There are some controversial studies on effects of anti-epileptic drugs [AEDs] on serum IgG subclasses; however, the role of these medications is still unclear. The aim of this study was evaluation the effects of anti-epileptic drugs on serum concentration of IgG and its subclasses. Serum IgG and IgG subclasses of 61 newly diagnosed epileptic patients were measured at the beginning of monotherapy with carbamazepine, sodium valproate, and phenobarbital, and 6 months later. Measurement of IgG and its subclasses was performed using nephlometry and ELISA techniques, respectively. Reduction of at least one IgG subclass was found in 6 patients 6 months after treatment with AEDs. Among 27 patients receiving carbamazepine, decrease in at least one serum IgG subclass level was found in 5 patients. Among 20 patients using sodium valproate, only one patient showed decrease in IgG2 subclass. None of the 14 patients using phenobarbital revealed significant decrease in IgG subclasses. No infection was seen in the patients with reduction of subclasses. Although in our study, children with selective IgG subclass deficiency were asymptomatic, assessment of serum immunoglobulin levels could be recommended at starting the administration of AEDs and in serial intervals afterward in epileptic patients

Cambio del isotipo en la respuesta a antígenos T independientes por co-inoculación con antígenos T dependientes / Isotype switch in the response against T independent antigens by co-inoculation with T dependent antigens

Un paradigma clásico de la inmulogía plantea que para que ocurra cambio de isotipo en los anticuerpos es condición sine qua non la presentación del antígeno a un linfócito T colaborador por parte de una célula presentadora de antígenos. En el presente trabajo se diseñó un modelo animal, ratones BALB/c, de respuesta inmune frente a dos antígenos típicos. Se utilizo dextrán como antígeno T independiente (AgTI) y seroalbúmina bovina (SAB) como antígeno T dependiente (AgTD), y se estúdio la respuesta, analizando los isotipos de los anticuerpos específicos producidos. Los resultados obtenidos muestran que la respuesta a dextrán en presencia de SAB ocurre con cambio de isotipo (swith), essencialmente de IgM a IgG. Estos experimentos sugieren que la SAB genera un entorno bioquímico inductor de cambio de isotipo tanto en supropia via de procesamiento como en del dextrán. Los resultados señalan que la asociación exclusiva de los AgTDs con las respuestas em las que ocurre cambio de isotipo es incorrecta. Considerando el modelo propuesto resulta poco probable encontrar in vivo y en forma espontânea casos en los que los AgTIs ingreses al organismo aislados; en cambio, es mucho más probable que el ingreso ocurra conjuntamente con AgTDs, y en consecuencia ocurra cambio de isotipo.

Eficacia de la profilaxis con timomodulina sobre el número y duración de episodios infecciosos respiratorios en adultos con enfermedad pulmonar obstructiva crónica / Efficacy of thymomodulin on the number and uration of infectious episodes in patients with chronic obstructive pulmonary disease

En dos centros hospitalarios se realizó un ensayo clínico, aleatorizado, doble ciego, placebo controlado, para medir la eficacia de la timomodulina en la disminución de la frecuencia y duración de las reagudizaciones infecciosas en pacientes con enfermedad pulmonar obstructiva crónica (EPOC). Se administraron cápsulas de 80 mg de timomodulina tres veces al día ó placebo con la misma presentación. Del primero de enero de 1994 al 31 de marzo de 1995 se incluyeron 88 pacientes con EPOC confirmada clínica, funcional y radiológicamente. El tratamiento se administró durante un trimestre (invierno) y se hizo seguimiento durante los tres trimestres siguientes. La mayor reducción en el número de episodios infecciosos se observó en el transcurso del segundo trimestre de seguimiento: 0.19 (ñ 0.39) vs 0.50 (ñ 0.62), p=0.007, para el brazo de timomodulina y placebo, respectivamente, lo que correspondió a una reducción de 62 por ciento. El número de días en cama durante el primer trimestre fue de 0.06 (ñ 0.33) vs 0.95 (ñ 2.46), p=0.02 para timomodulina y placebo, respectivamente, y correspondió a una reducción de días en cama de 94 por ciento. Se obervó un incremento en los tres tipos de linfocitos T, CD3, CD4 y CD8. El análisis de mediciones repetidas mostró un incremento estadísticamente significativo en la proporción de CD3 (p= 0.004), CD4 (p=0.11) y CD8 (p= 0.01). Con base en estos resultados se propone administrar durante dos periodos del año la timomodulina, durante el primero y tercer trimestres, lo que reducira en gran medida el costo excesivo de ciclos repetidos de antibióticos y días de incapacidad y hospitalización