Search PubMed⌕ Search

Biomedical subjects

E Silva

Publications and source records attributed to E Silva.

At least 109 records · Page 6Linked to original sources
PubMed1994

Pertussis in Massachusetts, 1981-1991: incidence, serologic diagnosis, and vaccine effectiveness.

Massachusetts provides diphtheria-tetanus toxoid-pertussis (DTP) vaccine, and since 1980 has monitored pertussis with a statewide diagnostic service. The incidence of bacteriologically confirmed pertussis was 104.5 per 100,000 person-years in 1-month-old infants and declined progressively thereafter. Infants < 6 months old experienced disproportionate morbidity: 44% of bacteriologically confirmed pertussis, 64% of hospitalizations, and 71% of hospital days. Most children with pertussis had received < 3 DTP doses during childhood, whereas 87% of adolescents with pertussis had received > or = 4 doses. Serodiagnosis by single serum anti-pertussis toxin antibody ELISA increased the incidence of confirmed pertussis in persons 11-19 years old from 3.0 to 12.9 per 100,000 and in persons > or = 20 years old from 0.16 to 0.56 per 100,000. Bacteriologic methods underestimate pertussis incidence, but a single serum anti-pertussis toxin antibody ELISA is a practical method for population-based diagnosis in adolescents and adults.

Adult↗
PubMed1994

[Ebstein's anomaly of the tricuspid valve. Clinical tolerance up to 38 years of age and pregnancy].

Ebstein's Anomaly of the tricuspid valve has a variable degree of abnormality with a continuous change between mild and severe forms and, consequently, a variable clinical course. Pregnancy can also be well tolerated with a good fetal outcome. The authors present a case of a 44 year old woman with Ebstein's Anomaly of the tricuspid valve. Clinical evolution to the age of 38 and two term pregnancies in the third decade of life were well tolerated. The infants were normal and had an adequate development.

Adult↗
PubMed1994

Riboflavin sensitized photooxidation of tyrosine.

The oxygen reactive species generated during the photooxidation of tyrosine sensitized by riboflavin were studied and the products formed were isolated. It was found that this process occurs preferently through a type I mechanism, which involves the direct interaction between the excited state of the sensitizer and tyrosine. The formation of O2.-, H2O2 and .OH was detected along the photooxidative process. By changing H2O by D2O it could be established that 1O2 has no significant role in the photooxidation of tyrosine sensitized by riboflavin. When a previously irradiated solution of tyrosine was applied to a Sephadex G-15 column, four fractions could be separated corresponding to products having hydrodynamic volumes larger than those of the reactants. By the use of 14C-tyrosine the aminoacidic origin of the products could be determined; one of them was identified as bityrosine, according to its fluorescence properties and 1H-NMR spectrum.

Azides↗
PubMed1994

Hyponatremia and neuroleptic-induced obesity in rats.

The weight gain and hyperphagia induced by chronic administration of sulpiride in female rats were not prevented by the concomitant administration of an extra source of sodium. In addition, serum sodium levels were not affected, but potassium levels were significantly reduced by sulpiride administered for 1 week. These results suggest that sulpiride-induced obesity in rats is not related to sodium imbalance. The mechanism for the decrease in serum potassium levels and its relation with sulpiride-induced weight gain warrant further investigation.

Animals↗
PubMed1994

Compartment syndrome associated with infection of the upper extremity.

Compartment syndrome is a potentially devastating entity associated with a great variety of injuries, but to the authors' knowledge there are no known reports of infection documented as a cause. A retrospective review of 263 patients with upper extremity infections admitted to the orthopaedic infection ward during 1992 was conducted to identify patients with compartment syndrome directly associated with infection. Four patients' clinical presentations fulfilled the criteria: two presented with infection and compartment syndrome, and two developed compartment syndrome 2-12 hours after admission. All four had beta-hemolytic streptococci on initial culture; three of four grew Group A streptococcus. Fasciotomies and serial debridements were necessary. One patient ultimately underwent amputation through the elbow.

Adult↗
PubMed1993

Study of the fluorescence properties of normal and neoplastic human cervical tissue.

Fluorescence excitation-emission matrices (EEMs) were obtained in vitro for 18 cervical biopsies from 10 patients. At all excitation emission maxima, but especially at 330 nm excitation, 385 nm emission, the average normalized fluorescence intensity of histologically normal tissue is greater statistically than that of histologically abnormal tissue. A diagnostic algorithm based on the relative intensity at 330 nm excitation, 385 nm emission can differentiate histologically normal and abnormal biopsies with a higher sensitivity (89%), but a lower positive predictive value (67%) and specificity (44%) than colposcopy (78%, 88%, 89%, respectively). However, paired comparison of histologically normal and abnormal biopsies from the same patient results in a sensitivity of 75%, positive predictive value of 86% and specificity of 88% for spectroscopic identification of histologic abnormality similar to that of colposcopy. This pilot study indicates that fluorescence spectroscopy may be useful in differentiating normal and abnormal tissue; based on these results, a strategy for in vivo studies is discussed.

Algorithms↗
PubMed1993

Relationships between c-Ki-ras mutations, HPV types, and prognostic indicators in invasive endocervical adenocarcinomas.

OBJECTIVE: Ras gene mutations have been identified in squamous cell carcinomas of the cervix and are associated with advanced-stage tumors. The current study was designed to determine the prevalence of c-Ki-ras mutations in invasive endocervical adenocarcinomas and associations between mutations, HPV status, and known prognostic indicators. METHODS: Paraffin-embedded tissue samples from 32 cases of invasive adenocarcinoma of the endocervix were analyzed for the presence of c-Ki-ras mutations by amplification of DNA extracted from paraffin blocks using the polymerase chain reaction (PCR) and subsequent restriction enzyme digestion of the amplimers. This method allows detection of aspartic acid mutations of the c-Ki-ras gene at codons 12 and 13. Samples were also analyzed for the presence of HPV DNA using PCR and either "consensus sequence" primers or "type-specific" primers for HPVs 16 and 18. Patients' charts were reviewed for clinical information and correlations between clinical outcome and known prognostic indicators and the presence of c-Ki-ras mutations was assessed. RESULTS: c-Ki-ras codon 12 mutations were detected in only 4 of the 32 cases (12.5%) of invasive endocervical adenocarcinomas examined. No codon 13 mutations were detected. Fifty-nine percent of the cases were HPV 16 or HPV 18 DNA positive and only 1 of the 4 cases with a codon 12 mutation was associated with HPV 16 or HPV 18. There were no significant associations between stage or grade of tumor or outcome and the presence of codon 12 mutations. However, using the observed survival as computed by the Berkson Gage Method at 12 months, the estimated median survival for patients with c-Ki-ras codon 12 mutations is 29 months compared to 68 months for patients lacking codon 12 mutations. CONCLUSIONS: These results indicate that c-Ki-ras codons 12 and 13 mutations are uncommon in invasive endocervical adenocarcinomas.

Adenocarcinoma↗
PubMed1993

Traumatic rupture of the stomach secondary to Heimlich maneuver.

The case of a 93-year-old man who received a Heimlich maneuver while choking is reported. After the procedure, the patient presented with abdominal pain and ultimately was found to have developed a gastric rupture. He was hospitalized for 66 days. Review of the literature showed that only four gastric perforations related to the Heimlich maneuver have been documented. Other complications have occurred. It is reasonable to perform the procedure as an alternative to asphyxiation, but emergency physicians must be aware of the fact that life-threatening complications may ensue.

Aged↗
PubMed1993

Photoreactions of riboflavin with spermine and their role in tryptophan photoconsumption induced by riboflavin.

The influence of spermine (Spr) on riboflavin (Rb) and riboflavin-tryptophan (Rb-Trp) solutions irradiated at 450 nm under aerobic and anaerobic conditions was studied. In both systems, it is shown that Spr interacts with 3Rb probably giving spermine-derived and flavin-derived radicals. In the presence of oxygen, modified Rb is regenerated with the simultaneous production of the active oxygen species O2.- and/or HO2.. The addition of Spr to the Rb-Trp system under aerobic conditions leads to a small protection of Trp consumption, although oxygen consumption is increased. This small protection arises as a consequence of competitive interaction of Trp and Spr with 3Rb. The competition of Spr and oxygen for 3Rb could also explain the autocatalytic oxygen consumption observed in the presence of the amine. Under anaerobic conditions Spr produces a larger protection of Trp consumption, which is compatible with the larger Rb triplet lifetime expected under these conditions.

Animals↗
PubMed1993

Absence of hepatitis C virus in British patients with type 1 autoimmune chronic active hepatitis--a polymerase chain reaction and serological study.

Despite several studies from continental Europe reporting a high prevalence of antibodies to the hepatitis C virus (HCV), there has been little evidence of such infection in patients from the United Kingdom. The use of the polymerase chain reaction combined with two separate second generation anti-HCV assays is reported here in 58 UK patients with well-documented autoimmune chronic active hepatitis. All patients were in corticosteroid induced remission. All sera were collected prospectively for the specific purpose of this study. HCV-RNA was not detected by use of the polymerase chain reaction in any of the patients and antibodies to HCV were only detected in one patient. No evidence was found for the involvement of the hepatitis C virus in UK patients with classical, corticosteroid sensitive autoimmune chronic active hepatitis.

Adult↗
PubMed1992

Riboflavin-photosensitized anaerobic modification of rat lens proteins. A correlation with age-related changes.

When rat lens homogenate or its soluble protein fractions are irradiated in the presence of riboflavin, a photo-adduct is obtained between this vitamin and the lens proteins. Irradiation of these proteins in the presence of riboflavin also leads to a modification in the chromatographic elution pattern with an increase in the high-molecular-weight fraction. In an aging study with rats, it was shown that the proportion of the high-molecular-weight protein fraction significantly increased with age, whereas the proportion of the low-molecular-weight protein fraction concomitantly decreased. It is postulated that aging produces an increase in the accessibility of the tryptophan residues of the lens proteins, as established by iodide fluorescence quenching experiments.

Aging↗
PubMed1992

Pertussis outbreaks in groups claiming religious exemptions to vaccinations.

Four recent outbreaks of pertussis in Massachusetts illustrate some features that contribute to the increased incidence of the disease. The outbreaks involved unimmunized groups of children with philosophical or religious exemptions from school or day-care immunization requirements and children and adults who were reluctant to undergo antibiotic prophylaxis or therapy. Parents and physicians should be aware that failure to immunize and to cooperate in follow-up preventive measures can have public health and potential medicolegal repercussions.

Adolescent↗