Comparative SEM evaluation of penetration of adhesive systems in human dentin with a non-rinse conditioner and a self-etching primer

The purpose of this study was to compare the effect of a self-etching primer and a non-rinse conditioner with the effect of a conventional adhesive system on the penetration depth in dentin of human teeth, using scanning electronic microscopy (SEM). Fifteen human third molar teeth were sectioned into 2 pieces. All pieces were flattened with grade 600 to 1200 silicon carbide paper and divided into 6 groups: group 1 - Prime & Bond NT (NT), negative control; group 2 - 37% phosphoric acid + Prime & Bond NT (PANT), positive control; group 3 - Non-rinse Conditioner (NRC) + Prime & Bond NT (NRCNT); group 4 - NRC + Prime & Bond 2.1 (NRCPB); group 5 - NRC + Scotchbond MP (NRCSB); group 6 - Prompt L-Pop (PLP). All teeth were covered with Dyract AP. The tooth fragments were decalcified, and its resin replicas were evaluated by SEM by three previously standardized examiners. The penetration was scored from 0 (no penetration) to 3 (maximum penetration). The Kruskal-Wallis and Mann-Whitney U tests (p<0.05) showed three statistically homogeneous groups: (NT, NRCPB, NRCSB and PLP), (NRCNT) and [PANT]. The authors concluded that the self-etching primer and the non-rinse conditioner provide a lower penetration depth in human tooth dentin than the conventional adhesive system.     

Maternal anaphylaxis and fetal brain damage after intrapartum chemoprophylaxis

We report a case of maternal anaphylaxis following intrapartum chemoprophylaxis. The term fetus developed severe brain damage as a consequence of intrapartum asphyxia. The lesions resulted from maternal hypotension following anaphylaxis. We discuss the feto-maternal risks and the controversial treatment of such a condition. The increasing number of penicillin-treated parturients will result in further cases of maternal anaphylaxis than previously found.     

Towards a Mexican normative standard for measurement of the short format 36 health-related quality of life instrument

OBJECTIVE: To present the results of the application of the short format 36 instrument (SF-36) in the Mexican states of Sonora and Oaxaca. The levels of quality of life were compared with those from Canada and the United States. MATERIAL AND METHODS: The data were obtained using a survey on health service access, usage, and quality. The SF-36 is composed of 36 questions, which represent eight different domains on the health-related quality of life. These domains are used to estimate the physical and mental components of health. Data analysis was performed to calculate the average scores for each domain for the total sample, by gender and age groups in each state. The regional differences were assessed by the difference of means. RESULTS: The total response was 98.5% of the 4200 selected households. The percent response values were similar between the two states. A total of 5961 subjects older than 25 years of age completed the questionnaire. Males scored higher than females in all domains and in both components. Regardless of sex, the highest variation was observed in adults up to 64 years of age mainly in three domains: overall health, social function, and mental health; in the 65-74 year age group occurred mostly in social function and mental health; and in adults older than 75 year only in mental health. The young adult age group (25 to 44 years) showed variation in a greater number of domains, while women exhibited more variation in the "extreme" age groups, 25 to 34 years and 75 years and older. The mean scores in our sample were higher than those found in Canada and the United States in five domains and in the two summary components. Canada showed higher scores in the other three domains (overall health, social function, and mental health). CONCLUSIONS: SF-36 data are not available at the national level; hence, the authors recommend that their study results may serve as the normative reference for SF-36 in Mexico. Researchers using the SF-36 could compare their results with our reference, adjusted by gender and age in population-based studies. Considering that the study regions have contrasting social and economic characteristics, the data from the more developed state, Sonora, may be used as the normative standard. Data from Oaxaca would be used as the reference for less-developed states. The English version of this paper is available at: http://www.insp.mx/salud/index.html.     

A 4-methyl-substituted <Emphasis Type="Italic">meta</Emphasis>-iodobenzylguanidine analogue with prolonged retention in human neuroblastoma cells

Purpose As a part of our efforts to develop a meta-iodobenzylguanidine (MIBG) analogue with improved characteristics for the diagnosis and treatment of neuroendocrine tumours, 3-[¹³¹I]iodo-4-methyl-benzylguanidine ([¹³¹I]MeIBG) has been developed. The purpose of this study was to evaluate [¹³¹I]MeIBG in vitro using the uptake-1 positive SK-N-SH neuroblastoma cell line and in vivo in normal mice and mice bearing human neuroblastoma xenografts.Methods The ability of SK-N-SH human neuroblastoma cells to retain [¹³¹I]MeIBG in vitro over a period of 4 days, in comparison to [¹²⁵I]MIBG, was determined by a paired-label assay. Paired-label biodistributions of [¹³¹I]MeIBG and [¹²⁵I]MIBG were performed in normal mice as well as in athymic mice bearing SK-N-SH and IMR-32 human neuroblastoma xenografts.Results Retention of [¹³¹I]MeIBG by SK-N-SH cells in vitro was increased by factors of 1.2, 1.5, 2.0, 2.5 and 3.1 compared with [¹²⁵I]MIBG at 8, 24, 48, 72 and 96 h, respectively. In normal mice, the uptake of [¹³¹I]MeIBG in the heart was similar to that of [¹²⁵I]MIBG at 1 and 4 h; in contrast, myocardial uptake of [¹³¹I]MeIBG was 1.6-fold higher than that of [¹²⁵I]MIBG (p<0.05) at 24 h. When mice were pre-treated with the uptake-1 inhibitor desipramine (DMI), the heart uptake of both tracers was reduced to about half that in untreated controls at 1 h post injection (p<0.05). The hepatic uptake of [¹³¹I]MeIBG was two- to threefold lower than that of [¹²⁵I]MIBG. On the other hand, blood levels of [¹³¹I]MeIBG were substantially higher (up to sixfold), especially at early time points. Uptake of [¹³¹I]MeIBG in heart and tumour at 1 h in the murine SK-N-SH model was specific and comparable to that of [¹²⁵I]MIBG. However, [¹³¹I]MeIBG uptake was 1.6- to 1.7-fold lower than that of [¹²⁵I]MIBG over 4–48 h. While the uptake of both tracers in IMR32 xenografts was similar, it was not uptake-1 mediated.Conclusion Introduction of a methyl group at the 4-position of MIBG seems to be advantageous in terms of higher tumour retention in vitro and lower hepatic uptake in vivo. However, the slower blood clearance of MeIBG may be problematic for some applications.     

Adverse effects of hyperphosphatemia on myocardial hypertrophy, renal function, and bone in rats with renal failure

BACKGROUND: Hyperphosphatemia and disturbances in calcium or parathyroid hormone (PTH) metabolism contribute to the high incidence of cardiovascular disease and renal osteodystrophy in chronic renal failure (CRF). We evaluated the effect of hyperphosphatemia on the cardiovascular system, on renal function, and on bone in experimental uremia. METHODS: Wistar rats were submitted to parathyroidectomy (PTx) and 5/6 nephrectomy (Nx) with minipump implantation, delivering 1-34 rat PTH (physiologic rate), or were sham-operated and received vehicle. Only phosphorus content (low-phosphorus (LP) 0.2%; high-phosphorus (HP) 1.2%) differentiated diets. We divided the groups as follows: PTx +Nx +LP; sham + LP; PTx + Nx + HP; and sham + HP. Tail-cuff pressure and weight were measured weekly. After 2 months, biochemical, arterial, and myocardial histology and bone histomorphometry were analyzed. RESULTS: Heart weight normalized to body weight (heart weight/100 g body weight) was higher in PTx + Nx + HP rats (PTx + Nx + HP = 0.36 +/- 0.01 vs. sham + HP = 0.29 +/- 0.01, PTx + Nx + LP = 0.32 +/- 0.01, sham + LP = 0.28 +/- 0.01) (P < 0.05). Serum creatinine levels were higher in PTx + Nx + HP rats than in PTx + Nx + LP rats (1.09 +/- 0.13 vs. 0.59 +/- 0.03 mg/dL) (P < 0.05). Levels of PTH did not differ significantly between the groups. Myocardial and arterial histology detected no vascular calcification or fibrosis. Bone histomorphometry revealed an association, unrelated to uremia, between HP diets and decreased trabecular connectivity. CONCLUSION: Myocardial hypertrophy, impaired renal function, and adverse effects on bone remodeling were associated with hyperphosphatemia and were not corrected by PTH replacement. Although no vascular calcification was observed in this model, we cannot rule out an adverse effect of hyperphosphatemia on the vascular bed. Our finding underscores the importance of phosphorus control in reducing morbidity and mortality in CRF patients.     

Non-toxigenic pattern II and III Bacteroides fragilis strains: coexistence in the same host

Diarrhoeic stool samples from 334 0-5-year-old children were analysed with respect to the incidence of Bacteroides fragilis as well as other enteropathogens. B. fragilis was recovered in 9.3% (31/334) of the samples, and 79 strains were examined for the presence of the bft gene or the BfPAI flanking region using polymerase chain reaction assays. No enterotoxigenic B. fragilis strains were detected. In 29% (9/31) of the samples the coexistence of both II and III non-toxigenic B. fragilis (NTBF) patterns could be seen. In 51.6% (16/31) of the samples there existed a pattern II NTBF only, and in 19.4% (6/31) only pattern III could be detected. Strains from the same patient representing different patterns were submitted to pulsed-field gel electrophoresis assays. Fingerprints obtained by this technique showed that there was strong heterogeneity among strains from different individuals. However, different patterns from the same individual shared 100% similarity.     

Anti-Aspergillus fumigatus efficacy of pentraxin 3 alone and in combination with antifungals

The collectin pentraxin 3 (PTX3) is an essential component of host resistance to pulmonary aspergillosis. Here we examined the protective effects of administration of PTX3 alone or together with deoxycholate amphotericin B (Fungizone) or liposomal amphotericin B (AmBisome) against invasive aspergillosis in a murine model of allogeneic bone marrow transplantation. PTX3, alone or in combination with the polyenes, was given intranasally or parenterally either before, in concomitance with, or after the intranasal infection with Aspergillus fumigatus conidia. Mice were monitored for resistance to infection and parameters of innate and adaptive T-helper immunity. The results showed the following: (i) complete resistance to infection and reinfection was observed in mice treated with PTX3 alone; (ii) the protective effect of PTX3 was similar or superior to that observed with liposomal amphotericin B or deoxycholate amphotericin B, respectively; (iii) protection was associated with accelerated recovery of lung phagocytic cells and T-helper-1 lymphocytes and concomitant decrease of inflammatory pathology; and (iv) PTX3 potentiated the therapeutic efficacy of suboptimal doses of either antimycotic drug. Together, these data suggest the potential therapeutic use of PTX3 either alone or as an adjunctive therapy in A. fumigatus infections.