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Biomedical subjects

G Oliveira

Publications and source records attributed to G Oliveira.

At least 19 recordsLinked to original sources
PubMed2006

Genetic filtering and optimal sampling of Schistosoma mansoni populations.

Allelic variation in 6 microsatellite markers was compared between frozen Schistosoma mansoni eggs and laboratory-passaged worms originating from the same 5 fecal samples obtained from Brazilian residents. Based on allelic richness values, the number of alleles detected per locus did not differ between egg and worm DNA templates. However, our ability to score loci differed between these DNA templates, with worms providing more scored loci per individual than eggs. Differences also existed between the worms and eggs in the identity of the specific alleles that were detected. Additionally, we observed a reduction in homozygous genotypes among laboratory-passaged worms relative to the eggs. Allelic diversity curves were calculated by genotyping all worms from a representative host sample to determine the relationship between the number of alleles detected at a locus and the number of worms genotyped. Curves for the 5 residents' worm infrapopulations for each of the loci were very similar. The equation y=19.55 x ln(x) + 9.992 explained the association between sampling effort (x) and number of alleles detected (y) with an R(2) of 0.775. In conclusion, egg DNA templates and allelic diversity curves can benefit efforts to discern the sociological, ecological and evolutionary forces impacting the genetic diversity and disease epidemiology of human schistosomes.

Alleles↗
PubMed2005

Mitochondrial dysfunction in autism spectrum disorders: a population-based study.

A minority of cases of autism has been associated with several different organic conditions, including bioenergetic metabolism deficiency. In a population-based study, we screened associated medical conditions in a group of 120 children with autism (current age range 11y 5mo to 14y 4mo, mean age 12y 11mo [SD 9.6mo], male:female ratio 2.9:1). Children were diagnosed using Diagnostic and Statistical Manual of Mental Disorders criteria, the Autism Diagnostic Interview--Revised, and the Childhood Autism Rating Scale; 76% were diagnosed with typical autism and 24% with atypical autism. Cognitive functional level was assessed with the Griffiths scale and the Wechsler Intelligence Scale for Children and was in the normal range in 17%. Epilepsy was present in 19 patients. Plasma lactate levels were measured in 69 patients, and in 14 we found hyperlactacidemia. Five of 11 patients studied were classified with definite mitochondrial respiratory chain disorder, suggesting that this might be one of the most common disorders associated with autism (5 of 69; 7.2%) and warranting further investigation.

Adolescent↗
PubMed2005

Anaphylaxis to povidone in a child.

Povidone is an allergic agent present in numerous substances, food and medicines. The authors present the clinical case of a 9-yr-old male child admitted in the emergency room with anaphylaxis, in two occasions separated by a 6-month period. The first episode occurred 5 min after the first oral administration of Fluvermal (flubendazole) and the second occurred 10 min after cutaneous application of Betadine (povidone iodine solution). Previous cutaneous application of this solution and ingestion of mebendazole occurred without apparent adverse reactions. The allergy study revealed eosinophilia, an elevated total IgE level and positive prick-by-prick test for both drugs. A cutaneous prick-by-prick test with povidone (the sole common constituent) was also positive. This is probably the first case described in the literature of anaphylaxis induced by povidone in a child.

Anaphylaxis↗
PubMed2004

Polymorphism of 5HT2A serotonin receptor gene is implicated in smoking addiction.

Smoking behavior is influenced by genetic factors. Polymorphisms affecting the dopaminergic system have been linked to smoking habits. The aim of this study was to investigate if the T102C polymorphism of the 5-HT(2A) receptor gene is related to tobacco use, since this receptor modulates the mesolimbic dopamine system and the C allele is associated with reduced receptor gene expression. A sample of 625 subjects were genotyped and classified according to their smoking behavior (never, former, or current smokers). We found differences in the distribution of the genotypes when the current smokers were compared with the never + former smokers, suggesting that T102C polymorphism is associated with maintenance, but not with initiation of the smoking habit. The CC genotype was more frequent in the current smokers than in the never + former smokers (chi(2) = 6.825, P = 0.03). The odds ratio of being a current smoker with a CC genotype was 1.63, 95% CI 1.06-2.51.

Adult↗
PubMed2004

Variants of the serotonin transporter gene (SLC6A4) significantly contribute to hyperserotonemia in autism.

The role of the serotonin system in the etiology and pathogenesis of autism spectrum disorders (ASD) is not clearly defined. High levels of platelet serotonin (5-HT) have been consistently found in a proportion of patients, and it is known that specific 5-HT transporter gene (SLC6A4) variants modulate transporter reuptake function, therefore possibly influencing the occurrence of hyperserotonemia in a subset of autistic patients. We have examined the association of platelet serotonin levels with two SLC6A4 polymorphisms, 5-HTT gene-linked polymorphic region (HTTLPR) in the promoter and intron 2 variable number of tandem repeats (VNTR), in a sample of 105 ASD patients, their parents, and 52 control children. Quantitative transmission disequilibrium test (QTDT) results showed a significant effect on 5-HT levels of each SLC6A4 marker (P=0.017 for HTTLPR; P=0.047 for intron 2 VNTR) and of haplotypes of the two markers (P=0.017), with a major contribution of the L.Stin2.10 haplotype (P=0.0013). A 5-HT mean value in the range of hyperserotonemia was associated with the homozygous L.Stin2.10 haplotype (H (1,N=97)=7.76, P=0.0054), which occurred in 33% of hyperserotonemic patients against 6% of patients with normal 5-HT levels (Fisher's exact test: P=0.013, OR=8). Allele interaction at the HTTLPR locus was found, with a significant dominance variance effect on 5-HT levels. We found no transmission disequilibrium of any of the SLC6A4 variants in ASD. Our results show that the SLC6A4 gene is a significant factor in the determination of 5-HT levels, and that specific SLC6A4 variants are associated with an increased risk for hyperserotonemia in our sample of autistic patients. The biological mechanism, however, is unlikely to involve the SLC6A4 gene solely. The associated SLC6A4 alleles likely interact with other genes or environmental factors to produce the abnormally high 5-HT levels observed in this subset of autistic patients, who possibly represent a separate etiological group.

Adolescent↗
PubMed2002

Characterization of new Schistosoma mansoni microsatellite loci in sequences obtained from public DNA databases and microsatellite enriched genomic libraries.

In the last decade microsatellites have become one of the most useful genetic markers used in a large number of organisms due to their abundance and high level of polymorphism. Microsatellites have been used for individual identification, paternity tests, forensic studies and population genetics. Data on microsatellite abundance comes preferentially from microsatellite enriched libraries and DNA sequence databases. We have conducted a search in GenBank of more than 16,000 Schistosoma mansoni ESTs and 42,000 BAC sequences. In addition, we obtained 300 sequences from CA and AT microsatellite enriched genomic libraries. The sequences were searched for simple repeats using the RepeatMasker software. Of 16,022 ESTs, we detected 481 (3%) sequences that contained 622 microsatellites (434 perfect, 164 imperfect and 24 compounds). Of the 481 ESTs, 194 were grouped in 63 clusters containing 2 to 15 ESTs per cluster. Polymorphisms were observed in 16 clusters. The 287 remaining ESTs were orphan sequences. Of the 42,017 BAC end sequences, 1,598 (3.8%) contained microsatellites (2,335 perfect, 287 imperfect and 79 compounds). The 1,598 BAC end sequences 80 were grouped into 17 clusters containing 3 to 17 BAC end sequences per cluster. Microsatellites were present in 67 out of 300 sequences from microsatellite enriched libraries (55 perfect, 38 imperfect and 15 compounds). From all of the observed loci 55 were selected for having the longest perfect repeats and flanking regions that allowed the design of primers for PCR amplification. Additionally we describe two new polymorphic microsatellite loci.

Animals↗
PubMed1998

Cytokine analysis of human renal allograft aspiration biopsy cultures supernatants predicts acute rejection.

BACKGROUND: A Th1 response is said to be associated with transplant rejection and Th2 with tolerance, although this is not agreed by all. Cytokines evaluation in peripheral blood and urine in kidney transplants produces variable results. We hypothesized that measurement of major cytokines involved in Th1/Th2 paradigm on transplant renal-infiltrating cells could bring valuable scientific and clinical information. METHODS: Fifty-six adult cadaver kidney transplants were subdivided into 21 stable patients (group A), 22 suffering acute rejection (group B), 10 with chronic rejection (group C) and three with CMV disease (group D). Fine-needle aspiration biopsies were cultured and their supernatants analysed for IL-2, IL-4, IL-10 and IFN-gamma. RESULTS: Group A produced small amounts of both IL-2 and IL-10 while group B synthetized significantly higher IL-2 and significantly lower IL-10 amounts than group A. Group B produced significantly more IL-2 than A on day 7 post-transplantation, several days before rejection supervened. Group C produced IL-10 and very low amount of IL-2. Group D produced both IL-2 and IL-10. We did not find any IL-4, and IFN-gamma was present in a few samples. For IL-2, sensitivity, specificity, negative and positive predictive values for acute rejection were 100, 87.2, 94.7 and 83.3%, respectively. CONCLUSIONS: Cytokine analysis in fine-needle aspiration biopsy cultures supernatants is a very useful immunological screening method for kidney transplants. IL-2 synthesis on day 7 post-transplantation reliably predicted the risk of impending acute rejection during the first weeks. The cytokine pattern suggests that acute rejection is associated with Th1, stable patients with Th0/Th2, and chronic rejection with Th2 patterns.

Acute Disease↗
PubMed1997

Cultures of aspiration biopsy specimens in the immunological monitoring of renal transplants.

OBJECTIVE: Graft-infiltrating cells (GIC) have been studied in heart, lung, and liver transplants and have been shown to have greater proliferative ability when taken from rejecting allografts. Our aim was to study GIC harvested by fine-needle aspiration biopsy (FNAB) in renal transplant recipients. PATIENTS AND METHODS: 93 adult patients entered the study. The FNABs were done on the 7th, 14th, and 30th day after transplantation in stable cases and whenever a rejection crisis supervened. RESULTS: The proliferation responses of GIC were significantly higher in rejection than in stable cases during the 1st month after transplantation. The sensitivity for rejection was 96.4%, the specificity 91.3%, the negative predictive value 98.7%, and the positive predictive value was 93.3% among dysfunctioning grafts. CONCLUSIONS: The study of the proliferative capacity of graft-infiltrating cells in renal transplants is a safe and very useful immunologic monitoring tool, and it could improve the FNAB diagnostic accuracy.

Adolescent↗
PubMed1995

24-hour blood pressure profile early after renal transplantation.

Renal transplant patients are often found to have high blood pressure. We studied 12 cyclosporine-treated patients 8-10 days after kidney transplantation by 24-hour ambulatory blood pressure monitoring, and once again at 35-40 days after kidney transplantation. The patients were found to have high mean blood pressure values at 8-10 days after transplantation, with a significant (p < 0.05) decrease at 35-40 days after transplantation (154.2 +/- 4.9/94.4 +/- 2.8 and 142.2 +/- 4.0/88.6 +/- 2.7 mmHg, respectively). A significant (p < 0.05) decrease in blood pressure values was also noted in the second series of measurements, when compared to the first series, in the day-time systolic and in the night-time systolic and diastolic blood pressure values, but not in the day-time diastolic blood pressure values. An abnormal day/night pattern of blood pressure ("non-dipper") was found in these patients in both occasions, with a difference between average blood pressure values during day- and night-time of 1.3/3.0 (systolic/diastolic) and 5.7/7.6 mm Hg at 8-10 and 35-40 days after transplantation, respectively. This tendency towards attenuation of the "non-dipper" pattern occurred in association with the decrease in body weight and of the dose of immunosuppressive drugs. As hemodynamic factors may play a role in both the short and the long-term function and viability of kidney transplant grafts, the high blood pressure and the "non-dipper" pattern of blood pressure found early after kidney transplantation may require a special therapeutic approach.

Adult↗
PubMed1995

Comparison of two doses of interferon-alpha-2b in intravesical prophylaxis of superficial bladder tumors. Portuguese Genito-Urinary Group.

The purpose of the study was to compare two doses of interferon-alpha 2b (60 and 100 million units, MU) and to define the recurrence rate per year, tumor rate per year and the toxicity for both treatment arms. 127 patients were admitted to the study and randomized between the two treatments: 64 patients in the 60-MU regimen (28 single primary, 8 multiple primary, 28 recurrent), and 63 patients (22 single primary, 10 multiple primary, 31 recurrent) in the 100-MU regimen. Of the 64 patients receiving 60 MU, 26 patients had recurrences (33 recurrences with a follow-up of 2,478 months). Of the 63 patients receiving 100 MU, 21 patients had recurrences (26 recurrences with a follow-up of 2,329 months). The recurrence rate per year for 60 MU is 0.13 and 0.11 for 100 MU and the tumor rate per year is 0.34 and 0.36, respectively. In conclusion the quality of life of the patients is very good with no side effects, and, using Fisher's exact test for statistical comparison, there was no difference in the recurrence rate per year and the tumor rate per year between the 2 groups.

Administration, Intravesical↗
PubMed1983

Megacystis-microcolon-intestinal hypoperistalsis syndrome in a newborn girl whose brother had prune belly syndrome: common pathogenesis?

A case of megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is presented. There were important findings: a urachal remnant and a brother with prune belly syndrome (PBS). After a review of the literature, many common characteristics of MMIHS and PBS are described: flaccid abdomen, dilatation of the urinary tract, intestinal malrotation, cryptorchidism, urachal remnants and familial incidence. MMIHS and PBS may be manifestations of the same underlying process.

Abnormalities, Multiple↗