Inactivation of the spxA1 or spxA2 gene of Streptococcus mutans decreases virulence in the rat caries model.

In oral biofilms, the major environmental challenges encountered by Streptococcus mutans are acid and oxidative stresses. Previously, we showed that the transcriptional regulators SpxA1 and SpxA2 are involved in general stress survival of S. mutans with SpxA1 playing a primary role in activation of antioxidant and detoxification strategies whereas SpxA2 serves as a back up activator of oxidative stress genes. We have also found that spxA1 mutant strains (∆spxA1 and ∆spxA1∆spxA2) are outcompeted by peroxigenic oral streptococci in vitro and have impaired abilities to colonize the teeth of rats fed a highly cariogenic diet. Here, we show that the Spx proteins can also exert regulatory roles in the expression of additional virulence attributes of S. mutans. Competence activation is significantly impaired in Δspx strains and the production of mutacin IV and V is virtually abolished in ΔspxA1 strains. Unexpectedly, the ∆spxA2 strain showed increased production of glucans from sucrose, without affecting the total amount of bacteria within biofilms when compared with the parent strain. By using the rat caries model, we showed that the capacity of the ΔspxA1 and ΔspxA2 strains to cause caries on smooth tooth surfaces is significantly impaired. The ∆spxA2 strain also formed fewer lesions on sulcal surfaces. This report reveals that global regulation via Spx contributes to the cariogenic potential of S. mutans and highlights that animal models are essential in the characterization of bacterial traits implicated in virulence.

[Survival and infectious processes in pacients with AIDS: analysis based on initial serum vitamin A levels]. / Sobrevida e processos infecciosos em pacientes com AIDS: análise de acordo com os níveis séricos iniciais de vitamina A.

Patients with Aids (n = 39) were followed up for a maximum period of 36 weeks, after which the types and topographies of infectious complications presented and patient survival were analyzed and correlated with the vitamin A levels presented by the patients at the beginning of clinical follow-up. Twenty-one (53,8%) patients presented serum retinol levels below 1.6 micromol/L, 12 (57%) of whom had values lower than 1.05 micromol/L. There was no correlation between low serum vitamin A levels and the types or topographies of the infectious complications that occurred during the follow-up period. Although mean survival at the end of the 36 months follow-up period was similar for the two groups, patients with retinol deficiency presented a lower probability of survival during the first 24 months of follow-up compared to patients without hypovitaminosis A (8.44 x 1.42 months; p = 0.003).

Human leukocyte antigen class II alleles in white Brazilian patients with celiac disease.

BACKGROUND: Celiac disease (CD) is a permanent gluten intolerance disorder characterized by malabsorption, intestinal mucosa villus atrophy, and crypt hyperplasia. Clinical and histologic features improve in persons consuming a gluten free diet. The pathogenesis of CD involves environmental, genetic, and immunologic factors. METHODS: The frequencies of human leukocyte antigen (HLA) class II alleles were evaluated in white Brazilian patients who had CD and compared with those observed in healthy individuals from the same geographical area (Ribeirão Preto, São Paulo) and of similar ethnic background. Twenty-five patients with CD, 11 females and 14 males, and 91 control individuals were studied. The HLA class II alleles were typed using amplified DNA hybridized with sequence-specific primers. Statistical analysis was performed using the two-tailed Fisher exact test. The relative risk (RR), etiologic fraction (EF), and preventive fraction (PF) were also estimated. The EF represents the attributable risk for the development of CD at the population level, whereas PF represents the protective risk. RESULTS: The frequency of the HLA-DRB1*03, HLA-DRB1*07, and HLA-DQB1*02 alleles was significantly increased in patients. The RR conferred by these alleles was 5.35, 7.15, and 10.6, respectively, and the EF was 48.7%, 44.7%, and 76%, respectively. The frequency of HLA-DQB1*06 alleles was significantly decreased in CD patients, conferring an RR of 0.08 and a PF of 48%. CONCLUSIONS: The results show that HLA-DRB1*03, HLA-DRB1*07, and HLA-DQB1*02 alleles conferred susceptibility to CD in Brazilian patients. In contrast, HLADQB1*06 alleles conferred protection against development of the disease.

Relation of the disaccharidases in the small intestine of the rat to the degree of experimentally induced iron-deficiency anemia

Hypolactasia associated with severe iron-deficiency anemia has been reported in several studies. The objective of the present study was to determine whether hypolactasia is associated with the degree and duration of iron-deficiency anemia. Newly weaned male Wistar rats were divided into a control group receiving a diet supplemented with iron (C) and an experimental group (E) receiving a diet not supplemented with iron (iron-deficiency diet). The animals were studied on the 3rd, 5th, 7th, 14th, 21st, 28th and 35th days of the experiment, when overall and iron nutritional status and disaccharidase activity in the small intestine were determined by the Dahlqvist method. A reduction in weight occurred in the anemic animals starting on the 5th day of the study. Anemia was present in the experimental animals, with a progressive worsening up to the 14th day (hemoglobin: C = 13.27 and E = 5.37) and stabilizing thereafter. Saccharase and maltase activities did not differ significantly between groups, whereas lactase showed a significant reduction in total (TA) and specific activity (SA) in the anemic animals starting on the 21st day of the study. Median lactase TA for the C and E groups was 2.27 and 1.25 U on the 21st day, 2.87 and 1.88 U on the 28th day, and 4.20 and 1.59 U on the 35th day, respectively. Median lactase SA was 0.31 and 0.20 U/g wet weight on the 21st day, 0.39 and 0.24 U/g wet weight on the 28th day, and 0.42 and 0.23 U/g wet weight on the 35th day, respectively. These findings suggest a relationship between the enzymatic alterations observed and both the degree and duration of the anemic process. Analysis of other studies on intestinal disaccharidases in anemia suggests that the mechanism of these changes may be functional, i.e., that the enterocytes may suffer a reduction in their ability to synthesize these enzymes.

Relation of the disaccharidases in the small intestine of the rat to the degree of experimentally induced iron-deficiency anemia.

Hypolactasia associated with severe iron-deficiency anemia has been reported in several studies. The objective of the present study was to determine whether hypolactasia is associated with the degree and duration of iron-deficiency anemia. Newly weaned male Wistar rats were divided into a control group receiving a diet supplemented with iron (C) and an experimental group (E) receiving a diet not supplemented with iron (iron-deficiency diet). The animals were studied on the 3rd, 5th, 7th, 14th, 21st, 28th and 35th days of the experiment, when overall and iron nutritional status and disaccharidase activity in the small intestine were determined by the Dahlqvist method. A reduction in weight occurred in the anemic animals starting on the 5th day of the study. Anemia was present in the experimental animals, with a progressive worsening up to the 14th day (hemoglobin: C = 13.27 and E = 5.37) and stabilizing thereafter. Saccharase and maltase activities did not differ significantly between groups, whereas lactase showed a significant reduction in total (TA) and specific activity (SA) in the anemic animals starting on the 21st day of the study. Median lactase TA for the C and E groups was 2.27 and 1.25 U on the 21st day, 2.87 and 1. 88 U on the 28th day, and 4.20 and 1.59 U on the 35th day, respectively. Median lactase SA was 0.31 and 0.20 U/g wet weight on the 21st day, 0.39 and 0.24 U/g wet weight on the 28th day, and 0.42 and 0.23 U/g wet weight on the 35th day, respectively. These findings suggest a relationship between the enzymatic alterations observed and both the degree and duration of the anemic process. Analysis of other studies on intestinal disaccharidases in anemia suggests that the mechanism of these changes may be functional, i.e., that the enterocytes may suffer a reduction in their ability to synthesize these enzymes.

Postmortem tooth loss in human identification processes.

Teeth provide essential data for human identification. However, they are frequently lost during the process of skeletonization or under manipulation during exhumation. Because of the high frequency of postmortem tooth loss, this phenomenon was examined in three different samples, in an attempt to simulate the actual circumstances experienced in the forensic processes of identification of human remains. The method employed aimed to describe and quantify dental spaces, distinguishing between loss after death or before by extraction. The results showed a high prevalence of postmortem tooth loss: 41.37% in sample A, 56.83% in sample B and 3.96% in sample C. These losses were most frequent in the maxillary incisor group in all three samples analysed. These data underline the need for redoubled care in recovery, transportation and storage of crania, so that teeth are not lost, which could seriously compromise the identification process.

[Study of lung involvement in patients with cystic fibrosis] / Estudo do quadro pulmonar de pacientes com fibrose cística.

OBJECTIVE: To characterize the involvement of the respiratory apparatus of patients with cystic fibrosis in order to obtain a comprehensive view of their pulmonary picture.METHODS: Data were obtained retrospectively from the medical records of 16 patients with cystic fibrosis; arterial gas and spirometry data were obtained prospectively for the same patients, who were not in an acute pulmonary situation. The patients were subjects of both sexes aged 6 years or older who were followed up at the Pediatrics Outpatient Clinic of the University Hospital, Faculty of Medicine of Ribeirão Preto, USP.RESULTS: Median patient age was 114 months (9 years and 6 months) ranging between 72 - 360 months, and 68.75% were males. Productive cough was the most frequent symptom observed in 75% of the population studied. All patients had positive sputum culture obtained at least one year before, with Pseudomonas aeruginosa being detected in 81.25% of the cases. Arterial gases revealed some abnormalities in 81.25% of the patients and spirometry revealed abnormalities in 56.25%.CONCLUSION: All patients presented at least one type of pulmonary alteration. Measurement of arterial gases detected a larger number of patients with altered pulmonary function than did spirometry, but the two examinations complemented each other for a good evaluation of pulmonary function.

Hepatic capillariasis in children: report of 3 cases in Brazil.

Capillaria hepatica is a helminth that may cause an extremely rare condition of parasitic hepatitis. Only 29 cases have been published, 2 of them in Brazil. We report here 3 cases of children in Brazil with massive hepatic capillariasis who presented the characteristic triad of this type of infection, i.e., persistent fever, hepatomegaly, and eosinophilia. The diagnosis was made by liver biopsy. All children responded well after treatment with thiabendazole (case 1), albendazole (case 3), and albendazole in combination with a corticoid (case 2). Case 1 has been followed-up for 24 years, an event not previously reported in the literature.

Disaccharidase levels in normal epithelium of the small intestine of rats with iron-deficiency anemia.

Iron-deficiency anemia is the nutritional deficiency most frequently occurring throughout the world, which manifests as a complex systemic disease involving all cells, affecting enzyme activities and modifying protein synthesis. In view of these considerations, the objective of the present study was to determine the effects of iron-deficiency anemia on disaccharidases and on the epithelial morphokinetics of the jejunal mucosa. Newly weaned male Wistar rats were divided into 4 groups of 10 animals each: C6w received a standard ration containing 36 mg elemental iron per kg ration for 6 weeks; E6w received an iron-poor ration (5-8 mg/kg ration) for 6 weeks; C10w received an iron-rich ration (36 mg/kg ration) for 10 weeks; E10w received an iron-poor ration for 6 weeks and then an iron-rich ration (36 mg/kg) for an additional 4 weeks. Jejunal fragments were used to measure disaccharidase content and to study cell proliferation. The following results were obtained: 1) a significant reduction (P < 0.001) of animal weight, hemoglobin (Hb), serum iron and total iron-binding capacity (TIBC) in group E6w as compared to C6w; reversal of the alterations in Hb, serum iron and TIBC with iron repletion (E10w = C10w); animal weights continued to be significantly different in groups E10w and C10w. 2) Sucrase and maltase levels were unchanged; total and specific lactase levels were significantly lower in group E6w and this reduction was reversed by iron repletion (E10w = C10w). 3) The cell proliferation parameters did not differ between groups. On the basis of these results, we conclude that lactase production was influenced by iron deficiency and that this fact was not related to changes in cell population and proliferation in the intestinal mucosa.

Disaccharidase levels in normal epithelium of the small intestine of rats with iron-deficiency anemia

Iron-deficiency anemia is the nutritional deficiency most frequently occurring throughout the world, which manifests as a complex systemic disease involving all cells, affecting enzyme activities and modifying protein synthesis. In view of these considerations, the objective of the present study was to determine the effects of iron-deficiency anemia on disaccharidase and on the epithelial morphokinetics of the jejunal mucosa. Newly weaned male Wistar rats were divided into 4 groups of 10 animals each: C6w received a standard ration containing 36 mg elemental iron per Kg ration for 6 weeks; E6w received and iron-poor ration (5-8 mg/kg ration) for 6 weeks; C10w received an iron-rich ration (36 mg/kg ration) for 10 weeks; E10w received an iron-poor ration for 6 weeks and then an iron-rick ration (36 mg/kg) for an additional 4 weeks. Jejunal fragments were used to measure disaccharidase content and to study cell proliferation. The following results were obtained: 1) a significant reduction (P<0.001) of animal weight, hemoglobin (Hb), serum iron and total iron-binding capacity (TIBC) in groups E6w as compared to C6w; reversal of the alterations in Hb, serum iron and TIBC with iron repletion (E10w = C10w); animal weights continued to be significanly different in group E10w and C10w. 2) Sucrase and maltase levels were unchanged; total and specific lactase levels were significantly lower in group E6w and this reduction was reversed by iron repletion (E10w = C10w). 3) The cell proliferation parameters did not differ between groups. On the basis of these results, we conclude that lactase production was influenced by iron deficiency and that fact was not related to changes in cell population and proliferation in the intestinal mucosa.

Report of two cases of children with Budd-Chiari syndrome successfully treated with streptokinase.

Two children with Budd-Chiari syndrome were successfully submitted to thrombolytic therapy. This study suggests that streptokinase is safe and effective in the treatment of this syndrome and should be considered as primary treatment in case of early diagnosed acute disease in view of the poor prognosis and the aggressiveness of surgical treatment currently available.

[Neonatal cholestasis and cytomegalovirus infection: clinical and histopathologic forms]. / Colestase neonatal e infecção por citomegalovírus: formas de apresentação clínica e histopatológica.

Cytomegalovirus infection is symptomatic in only 10% of cases. The most frequent findings are cholestasis and hepatosplenomegaly. Ten patients who presented neonatal cholestasis associated with cytomegalovirus infection were studied. The majority had elevation of serum aminotransferases and mild abnormality of hepatic function. The histopathologic findings were: normal, giant cell hepatitis, bile duct proliferation (confused with extrahepatic biliary atresia) and ductopenia. The clinical course of the patients varied from disappearance of the symptoms (2 cases) to death (2 cases). Because of the possibility of confusing the histologic findings with extrahepatic biliary atresia, the etiology of neonatal cholestasis, including cytomegalovirus infection, should be determined as soon as possible.

[Lactose absorption and tolerance to different types of yogurts in adults with hypolactasia]. / Absorção de lactose e tolerância a diferentes tipos de iogurtes em adultos com hipolactasia.

It is known that lactose is better absorbed in yogurts than in milk by lactase-deficient individuals. This fact is due to the presence of beta-galactosidase activity in the yogurts, that are different concerning the caracteristics of the products. Thus, the aim of this study was to verify the absorption and tolerance of lactose in some yogurts consumed by our population. We studied 12 hypolactasic adults who, after diagnostic confirmation, were submitted to three breath hydrogen tests after ingestion of milk and two yogurts with different levels of beta-galactosidase. These activities were determined in each sample utilized. The lactose absorption was evaluated by the measurement of H2 eliminated in the expired air and the tolerance was assessed by the symptoms reported by the participants. The medians of the H2 maximum increment were 20 ppm/min for the milk, 10.5 for yogurt X and 5.5 for the yogurt Y. The area under the curve of H2 concentration presented a median of 960 in the test with milk, 420 with yogurt X and 270 with yogurt Y. These results showed statistically significant differences for milk and the two yogurts and similar among the yogurts. The score for symptoms also were different between the milk and the two yogurts and similar among the yogurts. A statistically significant association between absorption and tolerance was not observed, because many tolerant subjects were malabsorbers of lactose. These data show that lactose in yogurts is better absorbed and better tolerated than lactose in milk, suggesting that our products are similar to those of the literature concerning their capacity of hydrolising lactose "in vivo". In spite of the differences found "in vitro" among the beta-galactosidase, there were no significant differences of absorption and tolerance between the two yogurts studied.

Característica de produtos lácteos fermentados produzidos no Brasil: conteúdo de proteína e gordura, osmolaridade e valor calórico / characteristics of fermented dairy products in Brazil: protein and lipids content, osmolarity and caloric value

Foram estudadas algumas caracteristicas de produtos lócteos fermentados com vistas à sua utu/ilizaçäo em crianças com diarréia. Utilizaram-se amostras de iogurte de três marcas e tipos, coalhada industrializada e yakilt. Drtermonaram-se, nos mesmos, conteúdo de proteinas, , gorduras e osmolaridade e calculou-se o valor calórico destes produtos. A média dos niveis de proteina variou de 1,70 a 3,57, situando-se em torno de 3g por cento nos iogurtes e coalhadas. O conteúdo de gorduras variou de 0,07 a 3,56, sendo muito baixo nos iogurtes desnatados e no yakult (média de 0,58 e 0,07, respectivamente). A osmolaridade situou-se em torno de 490 nos iogurtes naturais, desnatados e nas coalhadas e foi bem mais alta nos produtos com acréscimo de açúcares (de 690 a 965)...

[Hepatic glycogenosis in childhood: clinical and laboratory findings in 20 patients]. / Glicogenose hepática na infância: achados clínicos e laboratoriais em 20 pacientes.

We studied 20 children with a clinical picture and laboratory study suggestive of hepatic glycogenosis. The age of the beginning of symptoms varied from birth to 24 months and the age at the diagnosis varied from 2 to 81 months. Hepatomegaly was found in all patients, diarrhea in 65% (13/26), "doll-face" in 55% (11/20) and convulsions in 50% (10/20). Nutritional evaluation showed more height deficiency than weight deficiency. Laboratory tests showed elevation of hepatic transaminases (12/19), hypercolesterolemia (8/14), hyperuricemia (6/17) and hypoglycemia (6/20). Liver function was not compromised in most of the cases. The results of glucagon tolerance test were variable. The histoenzymology study performed in 15 patients revealed the following results: Type VI (liver phosphorylase deficiency) in seven, Type I (glucose-6-phosphatase deficiency) in two, Type IV (brancher enzyme) in one and no conclusion could be drawn in five patients. The finding of hypoglycemia in few cases of this study can be justified by the few number of glycogenosis Type I, probably due to the fact that this type is the most easily diagnosed, with less necessity of referring them to specialized centers.

[Excretion of 99m Tc-DISIDA through the bile ducts in the etiological diagnosis of neonatal cholestasis]. / Excreção de 99mTc-DISIDA pelo trato biliar no diagnóstico etiológico da colestase neonátal.

We evaluated 51 tests of 99mTc-DISIDA excretion by the biliary tree in patients with neonatal cholestasis. The aim of the present study was to verify the value of this test in the differentiation of this syndrome, correlating it to the clinical and laboratory data. The case studied were divided into two groups: extrahepatic biliary atresia, 26 patients (50.9%) and no-extrahepatic biliary atresia, 25 patients (49.1%). Analyzing the results, we concluded that this test had 96% sensitivity, 56% specificity, 69% positive predictive value, 93% negative predictive value and 76.5% accuracy. The accuracy of this test was only lower than that of hepatic biopsy. We conclude that the hepatobiliary scintigraphy was very useful in the definition of extrahepatic biliary atresia, with less value in the group of neonatal hepatitis, perhaps due to the delayed referral of the patients, short time of the scintigraphy study or factors related to the etiology of cholestasis itself.

[Lactose content and beta-galactosidase activity in yogurt, cheeses and curdled milk made in Brazil]. / Conteúdo de lactose e atividade de beta-galactosidade em iogurtes, queijos e coalhadas produzidos no Brasil.

We studied yogurts and industrialized curdled milk in three different storage times, as well as homemade and Syrian curdled milk and cheeses. Lactose content (gm%) and beta-galactosidase activity were determined in these products. Lactose content was elevated in yogurts and curdled milk with a lactose reduction of about 22% compared to the lactose of cow milk, with a mean and standard desviation (M +/- SD) of 3.81 +/- 0.47 gm%. In the cheeses lactose content was low, between 1.91 and 0.03 g%. beta-galactosidase activity was present in yogurts and curdled milk, with values between 0.58 and 3.61 U in time I and M +/- SD of 0.15 +/- 0.23 U. A significant decrease of beta-galactasidase activity was observed during the storage time. By analyzing and comparing these findings with the literature, we conclude that the products studied, by their low content of lactose (cheeses and yakult) or by the presence of beta-galactasidase activity (yogurts and curdled milk at time I) probably would be tolerated by most hipolactasic persons.

[Celiac disease: report of 20 cases in Rio Grande do Norte, Brazil]. / Doença celíaca: relato de vinte casos no Rio Grande do Norte.

This paper shows that celiac disease exists in Northeast of Brazil and can be one of the causes of malnutrition in the State of Rio Grande do Norte. The authors present a study of 20 cases of celiac disease in the State of Rio Grande do Norte where there had not been any cases diagnosed before 1978. Ethnic aspects in the State seem to have influenced the occurrence of the disease since the European miscigenation has been more frequent than that of negroes and local indians. The cases are analysed in this paper and correlated with the literature.

[Experience with the impression cytology test for detecting vitamin A deficiency in children]. / Nuestra experiencia con el test de impresión citológica para detectar deficiencia de vitamina A en niños.

Impression cytology has been suggested as a relatively simple, cheap, practical and non invasive technique for documenting physiologically significant vitamin A deficiency. The vitamin A status of 41 patients was evaluated by serum retinol concentration by high power liquid chromatography (HPLC) and conjunctival impression cytology was performed on each child. All children with normal vitamin A status had normal conjunctival impression cytology. The sensibility of this method was 100%. However, in the 8 vitamin A deficient patients by impression cytology, only 6 of them showed low serum vitamin A levels. Impression cytology appears to detect preclinical vitamin A deficiency that this technique may by of potential usefulness as a screening tool for preclinical vitamin A deficiency populations.