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Biomedical subjects

M L Silva

Publications and source records attributed to M L Silva.

At least 19 recordsLinked to original sources
PubMed2001

Frequency of Trichomonas vaginalis, Candida sp and Gardnerella vaginalis in cervical-vaginal smears in four different decades.

CONTEXT: Vaginitis is one of the principal motives that lead women to seek out an obstetrician or gynecologist. Bacterial vaginosis, candidiasis and trichomoniasis are responsible for 90% of the cases of infectious vaginitis. OBJECTIVE: To verify the frequency of the three main causative agents of vaginitis, Trichomonas vaginalis, Candida sp and Gardnerella vaginalis, in four different decades (1960's, 1970's, 1980's and 1990's). DESIGN: Retrospective. PLACE: A tertiary referral center. PARTICIPANTS: Patients attended to as gynecology and obstetrics outpatients at the Faculdade de Medicina do Triângulo Mineiro during the years 1968, 1978, 1988, 1998, taken as samples of each decade. MAIN MEASUREMENTS: Diagnoses of infection by Trichomonas vaginalis, Candida sp and Gardnerella vaginalis were gathered from 20,356 cervical-vaginal cytology tests on patients attended to as gynecology outpatients at Faculdade de Medicina do Triângulo Mineiro during the years 1968, 1978, 1988, 1998, representing the four decades. The results were grouped according to the age group of the patients: under 20, between 20 and 29, between 30 and 39, between 40 and 49, and 50 or over. Statistical analysis was done via the chi-squared (Mantel-Haentzel) test with a significance level of 5%. RESULTS: In 1968 infections by Trichomonas vaginalis and Candida sp were diagnosed in 10% and 0.5% of the cytology tests and in 1978, 5.1% and 17.3%, respectively (P < 0.0001). Infection by Gardnerella vaginalis could only be evaluated in the latter two decades. In 1988, 19.8% of the women had positive tests for Gardnerella vaginalis, which was the most frequent agent in that year, diminishing in the subsequent decade to 15.9% (P < 0.0001). Candidiasis was the most frequent infection in 1998, detected in 22.5% of the tests (P < 0.0001). In a general manner, all the infections were most frequent among younger patients, especially those aged under 20, in all decades, whereas infections were least frequent among patients aged 50 or over (P < 0.05). CONCLUSION: There was a reduction in the frequency of cervical-vaginal infection by Trichomonas vaginalis and an increase in the frequency of Candida sp over the four decades studied. All the infections were most frequent in patients aged under 20 years.

Adult↗
PubMed2001

Intestinal microsporidiosis: a current infection in HIV-seropositive patients in Portugal.

Intestinal microsporidiosis is recognised as an important cause of opportunistic infections in immunocompromised patients, especially those with AIDS. Two species are implicated in diarrhoea and other gastrointestinal disease in HIV-infected patients: Enterocytozoon bieneusi and Encephalitozoon intestinalis. Diagnosis of gastrointestinal microsporidiosis was made by detecting spores of the parasite in stool specimens with Weber's modified trichrome stain and with some optical brightening agents such as UVITEX 2B or calcofluor white M2R. The identification of microsporidiosis at the species level was made using appropriate primers with PCR. The diagnosis of intestinal microsporidiosis is currently performed in the parasitology laboratory. In a study of 215 HIV-infected patients, conducted from 1996 to 1999 (approximately n = 60/year), we found a prevalence of spores of microsporidia of 51.5% (n = 31) in 1996, 14.0% (n = 5) in 1997 and 12.5% (n = 8) in 1998 and 42.8% (n = 25) in 1999. Using PCR we found that E. intestinalis was the only species responsible for the gastrointestinal symptoms in 49 patients with microsporidian spores (71%) and E. bieneusi in 29% (n = 20).

AIDS-Related Opportunistic Infections↗
PubMed2001

BI- and tricyclic diterpenoids from Halimium viscosum.

The study of the acid and neutral parts of the n-hexane extract of Halimium viscosum (S. João da Pesqueira, Portugal) has led to the isolation of various known diterpenoids with the ent-halimane skeleton. Five new compounds have now been isolated, one with the ent-halimane skeleton, and four with the valparane skeleton, two of them with the valparane skeleton degraded. The structures of these compounds, determined by spectroscopic methods using 2D experiments (1H-13C, HMQC and HMBC), were dimethyl 1(10)-halimen-15,18-dioate, dimethyl 3,19-dinor-15-valparen-2,4-dioate, methyl 16-nor-2,3-secovalpara-3,15-dioxo-2-oate, 1,3,5,1 5-valparatetraene and 3R-4alpha-methoxy-15-valparen-2-one.

Cistaceae↗
PubMed1999

Evaluation of the trypanocidal activity of lignans isolated from the leaves of Zanthoxylum naranjillo.

Seven lignans isolated from the hexane extract of the leaves of Zanthoxyllum naranjillo (Rutaceae) were tested in both in vitro and in vivo assays against two strains of Trypanosoma cruzi (Bolivia and Y). Of the seven assayed lignans, three were inactive [(+)-sesamin, (+)-piperitol-4'-O-gamma, gamma-dimethylallyl ether and (-)-3,4-dimethoxy-3',4'-demethylenedioxycubebin] and three were partially active in the in vitro assays [(-)-hibalactone, (-)-kaerophylin and (-)-cubebin]. Healthy animals developed the disease after injection of the tested infected blood samples containing these three compounds. One compound [(-)-methylpluviatolide] was highly effective in the in vitro assay and healthy animals injected with the tested samples did not develop the disease. Moreover, only (-)-methylpluviatolide was highly active against the bloodstream forms of both strains of T. cruzi for the in vivo assay. However, it was not active against the tissue forms of the parasite.

Animals↗
PubMed1998

Molecular cloning of translocation t(1;14)(q21;q32) defines a novel gene (BCL9) at chromosome 1q21.

Abnormalities of chromosome 1q21 are common in B-cell malignancies and have been associated with a poor response to therapy. The nature of the involved gene(s) on chromosome 1q21 remains unknown. A cell line (CEMO-1) has recently been established from a patient with precursor-B-cell acute lymphoblastic leukemia (ALL), which exhibited a t(1;14)(q21;q32). To identify the gene involved in this translocation, we have cloned both rearranged IGHJ alleles using long-distance inverse polymerase chain reaction (LDI-PCR). Two IGHJ fragments were amplified from CEMO-1 DNA and sequenced. One allele showed novel sequences upstream of JH5 with no homology to either IGH or any other sequences on the databases. Using a single-copy Xho I fragment immediately 5' of JH5, PAC clones were isolated and mapped to chromosome 1q21 on normal metaphases by fluorescence in situ hybridization (FISH), confirming that this allele represented the t(1;14)(q21;q32) breakpoint. Sequence analysis of the 1q21 Xho I fragment showed identity with an expressed sequence tag (EST), and this probe was therefore used to probe Northern blots. Two transcripts of 6.3 kb and 4.2 kb expressed at low level in mRNA from all tissues were detected: a third transcript of 1.6 kb was expressed only in thymus, spleen, and small intestine. Full-length BCL9 cDNA clones were obtained from a normal human fetal brain cDNA library supplemented by 5' and 3' RACE. Sequence analysis predicted a protein of 1394 amino acids containing 18% proline, 11% glycine, 11% serine, and 6% methionine, but no recognizable protein motifs or significant homologies to any other known proteins. The CEMO-1 1q21 breakpoint fell within the 3' UTR of the BCL9 gene. Low-level expression of BCL9 was detected in Epstein-Barr virus-transformed normal B cells by Northern blot; in contrast, abundant BCL9 expression was observed in CEMO-1, indicating that deregulated expression of this gene was one pathological consequence of the translocation. Screening of a panel of 39 B-cell malignancies with 1q abnormalities by Southern blot showed one additional case with a breakpoint in the 3' UTR of BCL9, indicating that this was a recurrent breakpoint. FISH analysis using an 850-kb YAC spanning BCL9 identified a further case with t(1;22)(q21;q11) causing juxtaposition of BCL9 to the IGlambda locus. Other breakpoints were heterogeneous, falling both centromeric (10 cases) and telomeric (10 cases) of the BCL9 gene. These data suggest that BCL9 may be the target of translocation in some B-cell malignancies with abnormalities of 1q21 and that deregulated BCL9 expression may be important in their pathogenesis.

Adult↗
PubMed1998

A methodology report of a randomized prospective clinical trial to assess velopharyngeal function for speech following palatal surgery.

Cleft lip and palate occurs in approximately 1 in every 750 live human births, making it one of the most common congenital malformations. Surgical closure of the palatal cleft does not always result in a velopharyngeal port capable of supporting normal speech. The University of Florida (UF), in collaboration with the University of São Paulo (USP), is engaging in a 5-year prospective, randomized controlled study to compare velopharyngeal function for speech outcomes between patients undergoing palatoplasty for complete unilateral cleft lip and palate performed using the von Langenbeck procedure with intravelar velarplasty and those receiving the Furlow double-reversing Z-plasty palatoplasty. The von Langenbeck procedure was selected as the time-tested standard against which the Furlow procedure could be judged. The Furlow procedure, a relatively new operation, has been reported to yield substantially higher rates of velopharyngeal competency for speech than have most other reported series and theoretically should result in less disturbance to midfacial growth. A total of 608 patients will be entered into one of two age categories. Inclusion of two age groups will allow a comparison of results between patients having surgery before 1 year of age (9-12 months) and patients undergoing surgery at approximately 1.5 years of age (15-18 months). Speech data will be collected and will be available for definitive analysis throughout the last 3 years of the study. Collection of preliminary growth data will require more than 5 years; growth analysis is anticipated to continue until all patients have reached maturity. The Hospital for Research and Rehabilitation of Patients with Cleft Lip and Palate at the University of São Paulo (USP-HPRLLP) in Bauru, Brazil, is uniquely situated for conducting this study. The well-equipped and modern facilities are staffed by well-trained specialists representing all disciplines in cleft-palate management. In addition, an already existing social services network throughout Brazil will ensure excellent follow-up of study cases. The clinical caseload at this institution currently exceeds 22,000, and more than 1200 new cases are added annually. This project represents a unique opportunity to obtain prospective data from a large number of subjects while controlling the variables that have traditionally plagued cleft-palate studies. This study is designed to determine which of the two proposed surgical procedures is superior in constructing a velum capable of affecting velopharyngeal competency for the development of normal speech.

Cleft Palate↗
PubMed1997

Inhibition of enteropathogenic Escherichia coli adhesion to HEp-2 cells by colostrum and milk from mothers delivering low-birth-weight neonates.

UNLABELLED: Breast milk samples from three groups of Brazilian women were evaluated for their inhibitory effect on enteropathogenic Escherichia coli (EPEC) adhesion to HEp-2 cells: G1, mothers delivering preterm babies of appropriate birth weight (n = 12); G2, mothers delivering term babies of low birth weight (n = 11); G3, the control group, mothers delivering term babies of appropriate birth weight (n = 39). Colostrum samples were obtained at 48-72 h and milk samples on the 7th, 30th and 60th days after delivery. All samples showed strong inhibitory activity (66%-100%), without significant differences among the three groups and four periods. Total IgA and anti-EPEC IgA concentrations were significantly higher in colostrum than in milk samples in the three groups studied. The levels of colostral IgA and anti-EPEC IgA observed in G1 and G2 were significantly higher compared to the control group. Western blotting assays showed that individual samples as well as pools of colostrum or milk samples contain IgA antibodies to many EPEC outer membrane proteins. A 94 kDa band with molecular weight consistent with the EPEC adhesin named intimin; was recognized by all samples analysed. Bands of different molecular weight were also recognized by some samples of colostrum and milk, such as a band of approximately 18.4 kDa, with molecular weight equivalent to bundle-forming pilus subunits. CONCLUSION: Our results suggest that colostrum and milk from mothers of premature and small-for-date term neonates are as effective in protecting the newborn against EPEC infections as those from mothers of term babies of appropriate birth weight.

Analysis of Variance↗
PubMed1997

Human colostrum IgA antibodies reacting to enteropathogenic Escherichia coli antigens and their persistence in the faeces of a breastfed infant.

IgA antibodies reacting to enteropathogenic Escherichia coli (EPEC) antigens in human colostrum and their role in the inhibition of EPEC adherence to HEp-2 cells were studied. Colostrum IgA was isolated with a Sepharose anti-IgA column. IgA-depleted colostrum lost its inhibitory effect on EPEC adhesion, while the IgA-enriched eluate was a potent adherence inhibitor. The same eluate showed a significant loss of inhibitory activity after absorption with an EPEC strain showing localised adherence (LA+), but no alteration after absorption with an LA- strain. No bands were observed in Western blot analysis with LA+ absorbed eluate and with a crude extract of the EPEC strain, but the eluate absorbed with LA- showed a strong recognition of a 94-kDa band, a molecular weight equivalent to that of intimin. Colostrum antibodies reacting to non-protein antigens were not detected by Western blot analysis. The persistence of anti-EPEC IgA in the gastrointestinal tract was shown by the strong reactivity to the 94-kDa band in Western blot analysis of one mother's colostrum and her infant's faeces. These data confirm the role of colostrum antibodies in protecting the neonate against infections due to EPEC.

Adult↗
PubMed1996

Embolisation of vascular lesions of the spinal column in childhood: a report of three cases.

We report three cases of embolisation of hypervascular vertebral lesions in children. We embolised two cases of osteoblastoma prior to surgery, and one thoracic vertebral haemangioma. The technique and clinical results are described. We conclude that embolisation of vascular lesions of the spinal column in children is useful preoperatively or to reduce pain in vertebral haemangiomas.

Child↗