Forced expression of OCT4 influences the expression of pluripotent genes in human mesenchymal stem cells and fibroblasts.

Genetic reprogramming of adult cells to generate induced pluripotent stem (iPS) cells is a new and important step in sidestepping some of the ethical issues and risks involved in the use of embryonic stem cells. iPS cells can be generated by introduction of transcription factors, such as OCT4, SOX2, KLF4, and CMYC. iPS cells resemble embryonic stem cells in their properties and differentiation potential. The mechanisms that lead to induced pluripotency and the effect of each transcription factor are not completely understood. We performed a critical evaluation of the effect of overexpressing OCT4 in mesenchymal stem cells and fibroblasts and found that OCT4 can activate the expression of other stemness genes, such as SOX2, NANOG, CMYC, FOXD3, KLF4, and ßCATENIN, which are not normally or are very weakly expressed in mesenchymal stem cells. Transient expression of OCT4 was also performed to evaluate whether these genes are affected by its overexpression in the first 48 h. Transfected fibroblast cells expressed around 275-fold more OCT4 than non-transfected cells. In transient expression, in which cells were analyzed after 48 h, we detected only the up-regulation of FOXD3, SOX2, and KLF4 genes, suggesting that these genes are the earlier targets of OCT4 in this cellular type. We conclude that forced expression of OCT4 can alter cell status and activate the pluripotent network. Knowledge gained through study of these systems may help us to understand the kinetics and mechanism of cell reprogramming.

Antibodies to bovine serum albumin in Brazilian children and young adults with IDDM.

OBJECTIVE: To evaluate the prevalence of IgG antibodies to bovine serum albumin (BSA) in a cohort of Brazilian children and young adults with IDDM. RESEARCH DESIGN AND METHODS: Sera from 81 subjects with < 1 year of IDDM (group 1), III subjects with > 1 year of IDDM (group 2), and 207 normoglycemic subjects were tested using an immunofluorimetric assay. A receiver-operating-characteristic curve was used to establish the threshold of anti-BSA antibody titers defining the positivity of the assay. RESULTS: The distribution of the fluorimetric index (FI) of anti-BSA antibodies did not have a gaussian profile. Rank sum of FI was significantly higher in patients than in control subjects (P < 0.0001). Average logFI values of both IDDM groups were significantly higher than that of the control group (P < 0.005 for both groups). There was a trend toward higher FI levels in group 1 than in group 2 (P = 0.06). A FI cutoff of 0.7 optimized the ratio of true-positive to false-positive of the assay, with the best equilibrium between sensitivity and specificity. The prevalence of anti-BSA antibodies was 52% in group 1, 47% in group 2, and 28% in the control group (P = 0.0001). An independent association between anti-BSA antibodies and IDDM, with an odds ratio of 3.03 (P < 0.0001), was observed in a logistic regression analysis. However anti-BSA antibodies explained only 5% of the variability of IDDM versus NIDDM. CONCLUSIONS: Our results confirm that the prevalence of anti-BSA antibodies is higher in IDDM subjects than in control subjects, even after 1 year of diabetes. However, a large overlap of antibody titers is observed in patients and control subjects, suggesting that anti-BSA antibodies are neither sensitive nor specific markers of IDDM.

True insulin and intact proinsulin levels in acromegalic patients.

To determine whether proinsulin (PI) contributes significantly to the immunoreactive insulin (IRI) concentrations in acromegalics, we measure PI, "true insulin" and IRI in a group of acromegalics compared with a control group. Serum PI was determined by the immunofluorimetric assay (IFMA). Insulin was also determined by an IFMA that measures true insulin and by a radioimmunoassay (RIA). We performed an oral glucose tolerance test (OGTT) in a total group of 46 subjects: 10 controls with normal OGTT and body mass index < 25 kg/m2 (control group I), 10 controls with normal OGTT and body mass index > 25 kg/m2 (control group II), 15 patients with active acromegaly and normal OGTT and 11 patients with active acromegaly and IGT. Plasma glucose, serum GH, insulin and proinsulin were measured in all OGTT samples. Basal levels of insulin-like growth factor I (IGF-I) were measured in acromegalics. Mean body mass index in acromegalics with normal and impaired glucose tolerance were significantly higher compared with control group I and similar when compared with control group II. Proinsulin increased during OGTT in acromegalics with impaired glucose tolerance compared to control group I, and only fasting proinsulin compared to control group II. In normal OGTT acromegalics, only fasting proinsulin was increased. The RIA insulin during OGTT was significantly higher for both acromegalic groups compared to control group I and only at fasting when compared with control group II. This difference was not evident when insulin was measured by IFMA. These results suggest that in acromegalics, hyperinsulinism measured by RIA was at least in part due to hyperproinsulinism.

Proinsulin and insulin levels according to glucose tolerance among Japanese-Brazilians, aged 40-79 years. Japanese-Brazilian Diabetes Study Group.

This study of the Japanese-Brazilians living in Bauru, Sao Paulo, Brazil, aimed at determining the prevalence of DM in the first (Issei) and second (Nisei) generations, according to WHO criteria. Insulin and proinsulin were determined by new immunofluorimetric assays (IMFA), that measure true insulin and intact proinsulin, at fasting and 2 h after glucose load. The data showed a very scattered distribution, so only medians are shown and no statistical testing applied. There was a tendency for higher proinsulin levels in the diabetic groups. The highest fasting proinsulin levels were seen in the diabetic patients, either obese or non-obese. The post-load insulin levels were higher in diabetic and IGT individuals, compared to normals. Both generations showed a distinct behaviour for the obese and non-obese groups, and no major differences were observed between generations. This population seems to be sensitive to environmental changes, since the obese groups showed the higher levels of proinsulin and insulin. In the evaluation of the role of the environmental factors in the pathogenesis of DM, proinsulin and insulin levels could act as early markers of pancreatic dysfunctions.

Specific insulin and proinsulin in normal glucose tolerant first-degree relatives of NIDDM patients.

In order to identify early abnormalities in non-insulin-dependent diabetes mellitus (NIDDM) we determined insulin (using an assay that does not cross-react with proinsulin) and proinsulin concentrations. The proinsulin/insulin ratio was used as an indicator of abnormal beta-cell function. The ratio of the first 30-min increase in insulin to glucose concentrations following the oral glucose tolerance test (OGTT; I30-0/G30-0) was taken as an indicator of insulin secretion. Insulin resistance (R) was evaluated by the homeostasis model assessment (HOMA) method. True insulin and proinsulin were measured during a 75-g OGTT in 35 individuals: 20 with normal glucose tolerance (NGT) and without diabetes among their first-degree relatives (FDR) served as controls, and 15 with NGT who were FDR of patients with NIDDM. The FDR group presented higher insulin (414 pmol/l vs 195 pmol/l; P = 0.04) and proinsulin levels (19.6 pmol/l vs 12.3 pmol/l; P = 0.03) post-glucose load than the control group. When these groups were stratified according to BMI, the obese FDR (N = 8) showed higher fasting and post-glucose insulin levels than the obese NGT (N = 9) (fasting: 64.8 pmol/l vs 7.8 pmol/l: P = 0.04, and 60 min post-glucose: 480.6 pmol/l vs 192 pmol/l: P = 0.01). Also, values for HOMA (R) were higher in the obese FDR compared to obese NGT (2.53 vs 0.30; P = 0.075). These results show that FDR of NIDDM patients have true hyperinsulinemia (which is not a consequence of cross-reactivity with proinsulin) and hyperproinsulinemia and no dysfunction of a qualitative nature in beta-cells.

Relationship between insulin antibodies and metabolic control in type I diabetes mellitus.

1. The objective of the present study was to investigate whether a change in insulin therapy from bovine to purified porcine insulin would result in a decreased level of insulin antibodies (IA) in type I diabetic patients and whether there would be better metabolic control. 2. Insulin antibodies were measured by ELISA. Fifteen type I diabetic patients were prospectively followed for 8 months with monthly evaluations after changing insulin therapy from bovine to purified porcine insulin. 3. Group I patients (N = 4) had IA greater than or equal to 1.5 (value obtained by dividing the ELISA absorbance of the tested serum by the absorbance of a standard serum) at the beginning of the study. For group I patients, the modification of insulin therapy caused a 57% reduction in insulin antibody levels, and this reduction was correlated with a decrease in 24-hour glycosuria (rs = 0.66, P less than 0.001) and glycated protein (rs = 0.65, P less than 0.01). Group II patients (N = 8) had IA less than 1.5 and greater than or equal to 0.3 and group III (N = 3) had IA less than 0.3. Insulin antibody levels were unchanged during the follow-up period in both group II and group III. 4. We also studied endogenous insulin secretion, measured as fasting C-peptide, and its relationships with metabolic control and insulin antibody levels. Patients with residual insulin secretion (C-peptide greater than 60 pmol/l) showed lower levels of 24-h glycosuria, glycated protein and glycated hemoglobin. Furthermore, in this group of patients a negative correlation was found between C-peptide and insulin antibody levels (rs = -0.36, P less than 0.01). 5. We conclude that insulin antibodies could be one of the factors having a detrimental effect on metabolic control.

Detection of insulin antibodies by radioassay and ELISA: interrelation and correlation with metabolic control in type I diabetes.

1. The literature suggests that the radioassay (RA) and ELISA detect different types of insulin antibodies (IA) (Wilkin et al., 1989. Diabetes, 38: 172-181). 2. In the present study we evaluated the relationship between these two antibodies and their involvement in the metabolic control of Type I diabetic (DMI) patients. 3. IA were measured by RA and ELISA in sera obtained from 34 patients (age: 9-16 years, median = 12.5 years; clinical duration of DMI: 0.1-11.0 years, median = 1.7 years) treated with different types of insulin [purified (bovine + porcine) N = 18, and monocomponent (porcine or human) N = 16] and submitted to various degrees of metabolic control as assessed by glycosylated serum protein (GSP) levels: range, 3.4-13.5%; median = 8.7%; normal value, 0.8-2.4%. 4. Insulin antibody levels measured by RA were: 3264 +/- 300 nU/ml (mean +/- SEM, normal value < 60 nU/ml) and by ELISA: 0.74 +/- 0.11 ELISA index (EI) (normal value, < 0.53). No correlation was found between IA levels measured by RA and ELISA, or between duration of the disease or insulin daily necessity and IA by either method. GSP was positively correlated with IA determined by ELISA (rS = 0.43, P < 0.01) but not with IA determined by RA. 5. The patients on purified bovine + porcine insulin had higher titers of IA by ELISA, compared to those of patients on monocomponent (0.96 +/- 0.15 vs 0.50 +/- 0.13 EI, P < 0.03, while IA levels measured by RA did not differ between groups. 6. These data show that RA or ELISA assays provide different serum titers of IA in insulin-treated diabetics and data obtained with ELISA correlated best with the metabolic control of Type I diabetic patients.

Do impaired glucose tolerance and diabetes mellitus interfere with the interpretation of the growth hormone response to the oral glucose tolerance test?

1. The ability of glucose to suppress growth hormone (GH) secretion is well known and the glucose test is widely used for the diagnosis of acromegaly. However, when suspected acromegaly is associated with diabetes mellitus (DM) or impaired glucose tolerance (IGT) the interpretation of the GH response to the oral glucose tolerance test (OGTT) may be difficult. Recently, Hattori et al. (Journal of Clinical Endocrinology and Metabolism, 70: 771-778, 1990), using a highly sensitive (1.5 ng/l) polyclonal antibody-based immunoenzymometric assay, found no differences in the GH response to glucose load among control, IGT and DM patients. 2. We employed a less sensitive (100 ng/l) but monoclonal antibody-based immunoenzymometric assay to measure the serum GH levels of 19 normal subjects, 11 patients with DM and 11 patients with IGT to determine the effect of glucose intolerance on the GH response to the OGTT. 3. Complete suppression of GH (< 0.1 microgram/l) was achieved in 73% of the controls with a mean nadir of 0.17 +/- 0.16 microgram/l (range, < 0.1-0.6 microgram/l). GH was completely suppressed in 82% of the diabetics with a mean nadir of 0.58 +/- 1.21 micrograms/l (range, < 0.1-4.0 micrograms/l). However, complete suppression occurred in only 27% of the IGT patients with a nadir of 1.09 +/- 2.08 micrograms/l (range, < 0.1-7.0 micrograms/l), which was statistically higher than observed for controls and diabetics. 4. We conclude that plasma GH levels after glucose loading of IGT patients should be interpreted with caution because an abnormal response can be detected when some sensitive immunometric assays are employed.

Vitamin D receptor alleles and bone mineral density in a normal premenopausal Brazilian female population.

Studies on the association between vitamin D receptor (VDR) polymorphism and bone mineral density (BMD) in different populations have produced conflicting results probably due to ethnic differences in the populations studied. The Brazilian population is characterized by a very broad genetic background and a high degree of miscegenation. Of an initial group of 164, we studied 127 women from the city of São Paulo, aged 20 to 47 years (median, 31 years), with normal menses, a normal diet and no history of diseases or use of any medication that could alter BMD. VDR genotype was assessed by PCR amplification followed by BsmI digestion of DNA isolated from peripheral leukocytes. BMD was measured using dual energy X-ray absorptiometry (Lunar DPX) at the lumbar site (L2-L4) and femoral neck. Most of the women (77.6%) were considered to be of predominantly European ancestry (20.6% of them reported also native American ancestry), 12.8% were of African-Brazilian ancestry and 9.6% of Asian ancestry, 41.0% (52) were classified as bb, 48.8% (62) as Bb and 10.2% (13) as BB. The BB, Bb and bb groups did not differ in age, height, weight, body mass index or age at menarche. Lumbar spine BMD was significantly higher in the bb group (1.22 +/- 0.16 g/cm2) than in the BB group (1.08 +/- 0.14; P < 0.05), and the Bb group presented an intermediate value (1.17 +/- 0.15). Femoral neck BMD was higher in the bb group (0.99 +/- 0.11 g/cm2) compared to Bb (0.93 +/- 0.12) and BB (0.90 +/- 0.09) (P < 0.05). These data indicate that there is a significant correlation between the VDR BsmI genotype and BMD in healthy Brazilian premenopausal females.

Nocturnal urinary growth hormone excretion as a criterion for growth hormone deficiency.

Nocturnal urinary growth hormone (U-hGH) levels measured by a sensitive immunoenzymometric assay were compared with hGH levels in serum before and after a clonidine test in healthy children and in children with short stature to determine whether U-hGH measurement is useful for the screening of hGH deficiency. The study was carried out on 19 healthy children (10 prepubertal and 9 pubertal subjects) and on 20 children with short stature, 10 with growth hormone deficiency (hGHD) and 10 with constitutional growth retardation. The diagnosis of hGHD was based on a blunted response to two provocative hGH tests in the appropriate clinical setting. Overnight urinary hGH secretion (mean of 3 collections) was measured by an immunoenzymometric assay. The best discrimination was obtained when the results were expressed as ng/h. Only one individual in the prepubertal group (U-hGH, 0.05 ng/h) and one patient in the growth retardation group (U-hGH, 0.08 ng/h) had a urinary hGH value below the highest value (0.17 ng/h) observed in the growth hormone deficiency group. The coefficient of correlation between urinary hGH in ng/h and post-clonidine peak was 0.50 (P = 0.0015), between urinary hGH in ng/l and post-clonidine peak was 0.48 (P = 0.0025), between urinary hGH in ng/l per hour and post-clonidine peak was 0.47 (P = 0.0027). The highest specificity (0.93), sensitivity (0.90), false negative rate (0.96) and false positive rate (0.82) were obtained when U-hGH was expressed as ng/h per night. Measurement of urinary nocturnal hGH excretion is a useful, simple, noninvasive method for the diagnosis of hGH deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical trial of Myrcia uniflora and Bauhinia forficata leaf extracts in normal and diabetic patients.

1. Myrcia uniflora and Bauhinia forficata were compared with placebo for their hypoglycemic effect in randomized cross-over double-blind studies in 2 groups of normal subjects (10 subjects each) and 2 groups of Type II diabetic patients (18 in the M. uniflora group and 16 in the B. forficata group). The protocol with each plant lasted 56 days. 2. After the ingestion of infusions of 3 g leaves/day of M. uniflora and B. forficata leaves, no acute or chronic effects on plasma glucose levels or glycated hemoglobin were found in either group. However, plasma insulin levels in the diabetic group were lower after M. uniflora than after placebo. 3. Among other clinical parameters tested, a statistically significant difference was found only in the alkaline phosphatase level after placebo compared with that after M. uniflora in the normal group. 4. There were no differences in any clinical parameters after the use of placebo or of B. forficata. 5. We conclude that infusions prepared from the leaves of M. uniflora or B. forficata have no hypoglycemic effect on normal subjects or Type II diabetic patients.

A specific and highly sensitive time-resolved fluoroimmunoassay for human proinsulin.

We describe a time-resolved fluoroimmunoassay specific for human proinsulin using a combination of two high-affinity monoclonal antibodies, one against insulin and the other specific for intact proinsulin and for split 65-66 and des 64-65 proinsulin forms. The assay employs only 200 microl of serum, with a detection limit of 0.1 pmol/l. The intra-assay variation coefficient was less than 3% between 3 and 1000 pmol/l. There was 0% cross-reaction with insulin, C-peptide, split 32-33 and des 31-32 proinsulin. Serum concentration of proinsulin was analyzed in 50 subjects during an oral glucose tolerance test (10 non-obese control, 10 obese controls, 10 subjects with impaired glucose tolerance, 10 patients with type II diabetes mellitus (DM) and fasting blood glucose (FBG) < 140 mg/dl, and 10 patients with type II DM and FBG > 150 mg/dl). Mean fasting serum proinsulin levels measured by this assay in non-obese controls (0.84 - 0.90 pmol/l; 0.1-2.4 pmol/l) were lower than the results reported by other investigators. There was an increase of proinsulin related to obesity and increased glucose levels, suggesting that proinsulin levels increase with insulin resistance.

Insulin autoantibodies in first degree relatives of type I diabetic patients.

1. Insulin autoantibodies (IAA) of first-degree relatives of type I diabetic patients and recent-onset type I diabetics were measured by radioimmunoassay. A cut-off of 60 nU/ml was established on the basis of the values of normal control individuals. The intra-assay coefficient of variation was 9.2% for a moderately positive serum (1908 +/- 176 nU/ml (mean +/- SD), N = 7; range, 1708 to 2158 nU/ml). The interassay coefficient of variation was 23.8% for a negative (normal control) serum (28.1 +/- 6.7 nU/ml, N = 6; range, 22 to 39 nU/ml) and 14.5% in a highly positive serum (6185 +/- 899 nU/ml, N = 7; range, 5053 to 7009 nU/ml). 2. Insulin autoantibody levels (mean +/- SEM) were 19.3 +/- 2.8 nU/ml (range, -19 to 40 nU/ml) in 25 controls, 24.8 +/- 3.4 nU/ml (range, -17 to 59 nU/ml) in 41 type II diabetic patients, 18.5 +/- 2.4 nU/ml (range, -58 to 268 nU/ml) in 171 first-degree relatives of type I diabetic patients and 208.9 +/- 87.0 nU/ml (range, 10 to 1101 nU/ml) in 16 recent-onset type I diabetic patients. IAA levels were significantly higher in the last group compared with the other groups (P < 0.01). 3. None of the controls or type II diabetics exceeded the upper limit of normality. In contrast, 9 of 171 (5.3%) first-degree relatives and 9 of 16 (56.0%) recent-onset type I diabetic patients had IAA levels above the 60 nU/ml cut-off point.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the determination of insulin by a monoclonal antibody-based immunofluorometric assay and by radioimmunoassay.

This paper describes an immunofluorometric assay (IFMA) for insulin and compares it with the classical radioimmunoassay (RIA). Monoclonal antibodies against insulin were produced and used to develop the IFMA. One, immobilized on microtiter plates, was used for capture, the other, labelled with Europium, was used as tracer antibody. The IFMA presents sensitivity to an amount of insulin of 3 pmol/l and acceptable values for intra- and interassay error. The IFMA presented superimposable curves for human insulin, Arg65/Gly66-split proinsulin and des-Lys64,Arg65, and no cross-reactivity with human proinsulin, Arg32/Glu33-split and des-Arg31,Arg32. The RIA showed 100% cross-reactivity with human proinsulin, 90% with Arg32/Glu33-split, 193% with Arg65/Gly66-split, 340% with des-Arg31,Arg32 and 170% with des-Lys64,Arg65. The assays were used to measure insulin in 300 serum samples from 50 subjects submitted to an oral glucose tolerance test (OGTT). Twenty were normal, 10 had impaired glucose tolerance and 20 non-insulin-dependent diabetes mellitus. The mean value (+/- SEM) obtained by IFMA was 166.7 +/- 12.1 pmol/l and the mean value obtained by RIA was 339.6 +/- 18.6, with a correlation of r = 0.80 (P < 0.01). Comparison of basal insulin levels of the different groups of individuals using IFMA or RIA led to the same conclusions. The area under the curve showed statistically significant differences only for the comparison between normal lean subjects and individuals with impaired glucose tolerance, when measured by RIA. Our data stress the importance of methodology definition when comparing insulin results.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction among zinc, glucose, and insulin in normal individuals during glucose and tolbutamid perfusion.

Reports in the literature have shown that acute or chronic zinc administration may cause hyperglycemia, with a fall in serum or insular insulin occurring in experimental animals. On the other hand, under conditions of both acute and chronic hyperglycemia, an increase, a decrease, or a normal level of blood zinc has been observed in studies conducted on humans. Thus, the objective of the investigation described here was to determine the relationship existing among zinc, glucose, and insulin under acute conditions. Thirty-six subjects of both sexes (mean age, 23 yr) were tested at 7:00 A.M. after a 12-h fast. Two antecubital veins of both forearms were punctured and maintained with physiological saline. Three experiments were performed in which zinc was administered orally, and hypertonic glucose and tolbutamid were administered intravenously. Blood samples were then collected over a period ranging from 93 to 240 min after the basal times of -30 and 0 min. Hyperzincemia did not cause changes in plasma glucose or insulin either in the absence of or during perfusion of glucose. Hyperglycemia, hypoglycemia, and hyperinsulinemia did not modify serum zinc levels. These results demonstrate that acute zinc administration did not change carbohydrate metabolism and that sudden variations in glucose and insulin levels did not modify the serum profile of zinc.

Interrelationships of zinc with glucose and insulin metabolism in humans.

Hyperzincemia has been reported to cause alterations in the homeostasis of glycid metabolism. To determine this effect on plasma glucose and insulin levels, we studied 36 normal individuals of both sexes aged 22-26 y after a 12-h fast. The tests were initiated at 7:00 AM when an antecubital vein was punctured and a device for infusion was installed and maintained with physiological saline. Zinc was administered orally at 8:00 AM. Subjects were divided into an experimental group of 22 individuals who received doses of 25, 37.5, and 50 mg of zinc and a control group of 14 individuals. Blood samples were collected over a period of 240 min after the basal samples (-30 and 0 min). We did not detect any change in plasma glucose or insulin levels, a fact that we attribute either to the ineffectiveness of the 50 mg dose of zinc or to the lack of human response to the acute action of this trace element. The individuals who ingested zinc showed a significant fall in plasma cortisol, probably caused by the action of this trace element.

PCR in the first oropharynx aspirate of the newborn: a possible source for identification of congenital infection agents.

We present a case of prenatal diagnosis of congenital rubella. After birth, in addition to traditional serologic and clinical examinations to confirm the infection, we could identify the virus in the "first fluid aspirated from the oropharynx of the newborn", using polimerase chain reaction (PCR). We propose that this first oropharynx fluid (collected routinely immediately after birth) could be used as a source for identification of various congenital infection agents, which may not always be easily identified by current methods.

Serum type III procollagen peptides in patients with hepatointestinal and compensated hepatoesplenic schistosomiasis forms.

The Serum Type III Procollagen Peptides (SIIIPP) were determined in 35 individuals: 25 untreated schistosomotics: 16 with hepatointestinal (HI) and 9 with the compensated hepatosplenic (CHE) forms and a control group (C) consisted of 10 healthy volunteers. Kits of radioimmunoassay were performed for SIIIPP dosage. It was searched whether there was relationship between the SIIIPP and the serum levels of alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), alkaline phosphatase (AP) and gamma glutamyltranspeptidase (GGTP). The mean values of SIIIPP in the forms of HI (13.0 ng/ml) and CHE (17.0 ng/ml) were significantly higher than controls (9.0 ng/ml) (p less than 0.05). No significant difference was observed in SIIIP values between the HI and CHE patient groups, and between SIIIPP and ALAT, ASAT, AP and GGTP serum levels.

[Microleakage in class V cavities restored with esthetic materials, using different restorative techniques]. / Infiltração marginal em cavidades de classe V restauradas com materiais estéticos, utilizando diferentes técnicas restauradoras.

The purpose of this study was to compare the microleakage of class V cavities restored with composite resin (CR), resin-modified glass ionomer cement (RMGIC) and polyacid-modified resin composite (PAMRC), using different clinical procedures. Thirty-six noncarious human molars were used in this study. A class V cavity, measuring approximately 3 mm x 4 mm x 2 mm, was prepared in each tooth in both buccal and lingual aspects, with a diamond bur (number 1,093) at high speed, with coolant water spray. The occlusal margin was located on enamel and the gingival margin was located on dentin. The teeth were divided into 9 groups with 8 specimens each. The cavities were restored according to different techniques. The specimens from groups 1, 2, 4 and 5 did not receive acid etching. The samples were stored in water at 37 degrees C for 24 hours, subjected to occlusal load, thermocycled and immersed in rhodamine B. The restorations were then washed and sectioned in buccolingual direction. The depth of dye penetration was scored from zero (no leakage) to 3 (maximum leakage). The Kruskal-Wallis test revealed statistically significant differences between the materials (p < 0.05). PAMRC used without acid etching showed the greatest score of leakage in both margins. In the gingival margin, CR showed scores of leakage lower than those of PAMRC and RMGIC. Additional retentions and acid etching were able to decrease microleakage in PAMRC restorations in both gingival and occlusal margins.

[The non-insulin-dependent phase of type I diabetes mellitus]. / Aspectos da fase não-insulinodependent do diabetes mellitus do tipo I.

Case report on a child whose type I diabetes mellitus was diagnosed 23 months before the appearance of overt glucose intolerance. In this pre-IDDM stage of DMI were observed secondary enuresis, decreased growth speed, transient hyperglycemia and asymptomatic glycosuria. These alterations may represent the earliest clinical manifestation of impaired beta cell function. Immunologic markers (ICA and/or AAI) of DMI and abnormalities of the first-phase insulin secretion in response to intravenous glucose also may precede by several months the most common clinical picture of type I diabetes as they were detected in this child. If possible, markers and alterations should be tested in such patients and their young relatives with DMI in order to detect high risk individuals who may develop DMI. Such and accurate predictive ability should be a prerequisite to institution of appropriate therapy to preventing further beta cell destruction and severe metabolic decompensation, thus having the potential to reduce morbidity and mortality from new onset DMI.