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Biomedical subjects

S Costa

Publications and source records attributed to S Costa.

At least 127 records · Page 7Linked to original sources
PubMed1994

Hyperinsulinemia decreases second-phase but not first-phase arginine-induced insulin release in humans.

The aim of this study was to investigate the effect of hyperinsulinemia on the first and second phase of arginine-induced insulin release in humans. Seven healthy subjects underwent three studies (lasting 360 min): a control study using saline infusion and two euglycemic clamps using a low-dose (0.33 mU.kg-1.min-1) and a high-dose (1.20 mU.kg-1.min-1) insulin infusion. After a 3-h equilibration period, arginine (25 g) was infused for 30 min, and insulin and C-peptide responses to arginine were followed for 180 min. At the end of the equilibration period, before arginine administration, steady-state insulin levels were (means +/- SE) 60.0 +/- 2.4, 165.6 +/- 1.8, and 455.4 +/- 7.8 pmol/l during saline, low-dose, and high-dose insulin infusions, respectively. The time course of insulin release during the arginine test was calculated from C-peptide concentrations by using C-peptide kinetic modeling and deconvolution. In particular, first-phase and second-phase insulin response was obtained by integrating the time course of the insulin release during either the first 5 min or the following 40 min of the arginine test, respectively. Whereas first-phase insulin release was independent of any effect induced by either insulin infusion, second-phase insulin release was reduced in a similar degree by both insulin infusion doses. First phase was 75.5 +/- 10.1, 73.7 +/- 12.8, and 73.4 +/- 10.3 pmol/kg, whereas second phase was 266.1 +/- 46.0, 143.1 +/- 33.5, and 133.0 +/- 30.2 pmol/kg for saline, low-dose, and high-dose insulin infusions, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Immunohistochemistry with antibody to the LA-1 oncogene as a prognostic marker in cervical intraepithelial neoplasia.

Previous studies with antibody to a synthetic peptide designated LA-1 identified a 60-kDa protein in cervical intraepithelial neoplasia and invasive cancer tissues. To determine whether these findings are of clinical significance cervical tissues from 223 patients with squamous intraepithelial lesion (SIL) or invasive carcinoma and 39 normal healthy cervical tissues were stained with antibody to LA-1 using the immunoperoxidase assay. Tissues from 52 patients with squamous carcinomas at other sites were used as controls. Staining was respectively observed in 46.4, 56.5, and 64.7% of patients with low-grade SIL, high-grade SIL, and invasive cancer. It was localized in the atypical epithelium involving a progressively larger extent of epithelium as a function of increased pathologic grade. Only 10.3% of the normal cervical tissues stained with anti-LA-1 antibody. Twenty-five patients that were lost to follow-up for 2-5 years after the original diagnosis were studied at the time of diagnosis (1 degree biopsy) and when they returned to the clinic (2 degrees biopsy). In the follow-up series, LA-1 staining was observed in both biopsies from 9/12 patients that progressed to a higher degree of atypia, while 9/11 patients whose lesions remained stationary were LA-1 negative. Our studies suggest that LA-1 might be a useful biological marker of cervical neoplasia.

Adult↗
PubMed1993

Causes of death among persons reported with AIDS.

OBJECTIVES: This study describes causes of death in persons with acquired immunodeficiency syndrome (AIDS) and assesses the completeness of reporting of human immunodeficiency virus (HIV) infection or AIDS on death certificates of persons with AIDS. METHODS: AIDS case reports were linked with death certificates in 11 local/state health departments; underlying and associated causes of death were available for 32,513 persons with AIDS who died. RESULTS: HIV/AIDS was designated as the underlying cause of death for 46% of persons with AIDS who died between 1983 and 1986 and 81% of persons with AIDS who died since 1987 (the year specific coding procedures were implemented for HIV/AIDS). Most other underlying causes of death were conditions within the AIDS case definition (notably Pneumocystis carinii pneumonia), pneumonia, infections outside the AIDS case definition, and drug abuse. Unintentional injuries, suicide, and homicide were less common. HIV/AIDS was listed as underlying or associated on 88% of death certificates from 1987 to 1989; reporting varied primarily by HIV exposure category and time between diagnosis and death. CONCLUSIONS: Physicians and other health care professionals should realize their critical role in accurately documenting HIV-related mortality on death certificates. Such data can ultimately influence the allocation of health care resources for HIV-infected individuals.

Acquired Immunodeficiency Syndrome↗
PubMed1993

HIV infection in hospitalized patients and Medicaid enrollees: the accuracy of medical record coding.

To evaluate the accuracy of computerized medical-record coding for human immunodeficiency virus (HIV), medical charts were reviewed in six sites. In 7601 hospital and 867 Medicaid records with a listed diagnosis of HIV, the predictive value for HIV was 91% or higher. HIV was identified in 34% of 1155 Medicaid records listing immune disorder or illness in the acquired immunodeficiency syndrome (AIDS) surveillance definition (without an HIV code). In hospital and Medicaid records, AIDS was identified both in records listing AIDS and records listing HIV without AIDS. HIV codes on hospital and Medicaid records were highly predictive for HIV; undercoding of HIV occurred in Medicaid records.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Heart involvement in thymic neoformations: the role of magnetic resonance tomography. Experience in 3 cases].

Three paracardiac masses (1 thymic cyst, 2 thymomas) were studied by magnetic resonance imaging (MRI) using spin-echo, multi-echo, and gradient-echo sequences (cine-MR). MRI showed: a pedunculate cystic lesion, typical for thymic origin, in Case 1; cardiac and pulmonary infiltration, and 3 intracardiac metastases, in Case 2; cardiovascular compression but not infiltration, in Case 3. In 3/3 cases MRI was superior to transthoracic echocardiography (TTE), and in 2/2 MRI was superior to computed tomography (CT), not performed in Case 2 (allergy to contrast agents). MRI may be considered the most important technique to evaluate cardiovascular involvement by thymic neoplasms. MRI should be performed after TTE and makes CT unnecessary.

Adult↗
PubMed1992

Domoic acid toxicity in rats and mice after intracerebroventricular administration: comparison with excitatory amino acid agonists.

A behavioural study of the domoic acid (DOM)-induced convulsive behaviour after intracerebroventricular administration was carried out in rats and mice. DOM-induced behaviours were compared to those elicited by other excitatory amino acid (EAA) agonists N-methyl-D-aspartate (NMDA), alpha-amino-3- hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainic acid (KA), in such a way as to assess the possible similarities between DOM-induced effects and EAA subtype receptor activation in vivo. In rat, DOM (0.03-3 nmol/rat) caused a complex pattern of convulsive behaviour, quantified by means of a 15-point rating scale. DOM-induced behavioural profile was characterized at the lower doses by "preconvulsive" behaviours as wet dog shakes, hypermotility, mild facial clonus. At higher doses, DOM caused clonic convulsions followed by the "status epilepticus" syndrome (wet dog shakes, forelimb clonus, rearing, salivation). Rats treated with KA (0.3-10 nmol/rat) showed an almost identical behavioural profile. AMPA (1-10 nmol/rat)-induced convulsive behaviour was similar to DOM and KA only at the higher doses. NMDA (0.25-10 nmol/rat) caused clonic convulsions but not "status epilepticus". In mice, similar results were obtained: all the tested drugs induced generalized seizures, but only animals treated with DOM, KA and AMPA showed a prolonged sequence of seizures with forelimb clonus. Our results confirm the findings reported in the literature and support the hypothesis that DOM and KA act at the same EAA receptor.

Animals↗
PubMed1992

The completeness of AIDS case reporting, 1988: a multisite collaborative surveillance project.

OBJECTIVES: The purpose of this study was to evaluate the completeness of acquired immunodeficiency syndrome (AIDS) case reporting. METHODS: Statewide or hospital-specific 1988 medical records were linked with AIDS surveillance in six sites. Medical records were reviewed for persons who had diagnoses suggesting human immunodeficiency virus (HIV) infection or AIDS but were not reported to AIDS surveillance by September 1989. RESULTS: Among 4500 hospitalized persons diagnosed with AIDS through 1988 in the six sites, completeness of reporting was 92% (95% CI = 89%, 96%; range across sites = 89% to 97%). Completeness of reporting was high in males (92%), females (95%), Whites (95%), Blacks (90%), Hispanics (92%), men reporting sexual contact with men (92%), persons reporting injecting-drug use (91%), and persons exposed to HIV through heterosexual contact (99%). In Medicaid enrollees (two states), completeness of reporting was 99% (95% CI = 95%, 99%) in inpatients and 90% (95% CI = 79%, 90%) in outpatients. Of previously reported persons with AIDS, 82% were reported within 5 months of diagnosis. CONCLUSIONS: Completeness of AIDS reporting was high, overall and in each major demographic and HIV exposure group. These results demonstrate that current surveillance data in these six sites provide timely and accurate information regarding persons with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Is vestibular papillomatosis associated with human papillomavirus?

The origin and clinical significance of vestibular papillae were evaluated by comparing histological features with the presence of human papillomavirus (HPV) types 6/11 and 16/18, as revealed by Southern blot DNA hybridization. Twenty women with vestibular papillomatosis underwent clinical evaluation and follow-up. When available, male partners were also examined. Histological changes suggestive of HPV infection were present in all the 20 specimens. Sixteen cases (80%) contained DNA sequences homologous to the viral probes. In particular, 12 cases (60%) reacted with the HPV 16/18 probe. Follow-up for more than 18 months revealed no variation in the distribution and appearance of vestibular papillae. No male partner showed signs of HPV lesions. The study shows that HPV 16 is frequently associated with vestibular papillae but does not support a productive infection. Therefore the most appropriate management of these patients should be evaluated clinically in each individual case.

Adult↗
PubMed1990

Mapping of linear epitopes of human papillomavirus type 16: the L1 and L2 open reading frames.

Certain types of human papillomavirus (HPV), notably HPV type 16, are associated with flat or inverted proliferative lesions of the cervix uteri that can progress to malignancy. As a first step towards the serological study of the epidemiology of HPV, we have synthesized the entire amino acid sequences of the 2 major viral capsid proteins of HPV type 16, L1 and L2, as a set of 66 synthetic 20-residue peptides with an overlap of 5 amino acids. The peptides were tested for reactivity with IgA, IgG and IgM antibodies in the sera of 30 patients with HPV-16-carrying cervical neoplasms. Both IgG and IgM antibody responses were detected, but most of the reactivity found was of the IgA class. The most immunoreactive peptides were further analyzed for reactivity with sera from 22 patients with parotid gland tumors and with sera from 38 healthy individuals. The L2-encoded protein contained only one major linear epitope, which was not specific for HPV-16-carrying neoplasms. In contrast, the L1-encoded protein contained several epitopes that were regularly immunoreactive with antibodies present in the sera of patients with HPV-16-carrying cervical neoplasms, but only rarely so in the sera of patients with other tumors or of healthy individuals.

Amino Acid Sequence↗
PubMed1990

Effect of NMDA- and strychnine-insensitive glycine site antagonists on NMDA-mediated convulsions and learning.

Intracerebroventricular (ICV) injection of N-methyl-D-aspartate (NMDA) was shown to induce generalized seizures in mice. The competitive NMDA antagonists DL-2-amino-5-phosphonovaleroate (DL-AP7) and 3-(2-carboxypiperazin-4-yl)propyl-1-phosphonate (CPP), the NMDA "channel blocker" antagonist (+)-5-methyl-10,11-dihydro 5H-dibenzo-[a,d] cycloheptan-5,10-imine maleate (MK-801) and the strychnine-insensitive glycine antagonists kynurenic acid (KYNA) and 7-chloro-kynurenic acid (7-Cl-KYNA), when co-administered (ICV) with NMDA, antagonized NMDA-induced generalized seizures. Administration (ICV) of DL-AP7, CPP and MK-801 resulted in impared learning performance in a passive avoidance task in mice, with ED50 close to the anticonvulsant dose. The glycine antagonists KYNA and 7-Cl-KYNA at high doses significantly failed to affect performance in the same model of learning. The results indicate that compounds acting at the strychnine-insensitive glycine site may have a larger "therapeutic window" as anticonvulsants than antagonists of the NMDA receptor and channel.

2-Amino-5-phosphonovalerate↗
PubMed1990

Search for herpes simplex virus 2 and human papillomavirus genetic expression in vulvar neoplasia.

Specimens from vulvar carcinomas and vulvar intraepithelial neoplasia (VIN) of various degrees were analyzed for the presence of herpes simplex virus 2 (HSV 2) and human papillomavirus (HPV) genetic information. A search for the HPV 16 E6 protein as well as the HSV 2 antigenic determinant LA1 and ICSP 11/12 protein was carried out with an immunoperoxidase assay on 12 vulvar carcinomas and 6 VINs. Seven invasive cancers and four VINs were screened for the presence of homology to HPV 16 DNA and HSV 2 DNA transforming sequences with Southern blot hybridization. We used specimens from labial tumors and from normal vulvas and cervixes as controls. The preliminary results showed that one vulvar carcinoma and two VINs contained HPV 16 DNA. Four vulvar carcinomas expressed the E6 protein, while all the VINs were negative. Homology to HSV 2 DNA transforming sequences was detected in one vulvar cancer but not in any VIN cases. Positivity to HSV 2 ICSP 11/12 was observed in 33.3% of VIN cases and 75% of invasive cancers. HSV 2 LA1 antigenic determinant was expressed in 33.3% of VIN and 66.6% of cancer cases.

Adult↗
PubMed1990

[The importance of a teleradiographic evaluation of cardiac volume in subjects with the long QT syndrome].

The increase in electrocardiographic QT interval, denominated "long QT" syndrome, is related to syncopes and sudden death during anger, fear, physical effort, or sleep. Its diagnosis is important because mortality rate is high among untreated patients. In this study the author tried to single out, with the help of conventional radiology, some radiological elements belonging to this syndrome. Heart diameters and volume could be determined by means of teleroentgenography in 24 patients affected with "long QT" syndrome. The method employed considerably reduced the factors preventing a correct determination of heart size. In most of the cases examined, heart diameters and volume were increased, the heart had a globose shape with a lifted tip, the second right arch was accentuated, and the space behind the sternum reduced: these elements suggest a volumetric increase in the right sections of the heart. No relationship was found between QT value and increase in heart size. The results suggest the existence of a non-casual relationship between electrocardiographical anomaly and increase in the volume of the right sections of the heart.

Adolescent↗