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Biomedical subjects

A Vega

Publications and source records attributed to A Vega.

At least 19 recordsLinked to original sources
PubMed1992

Effects of staphylococcal enterotoxin B on rodent mast cells.

Staphylococcal enterotoxin B (SEB) was tested in rodent mast cell cultures for the release of serotonin. Both rat RBL-2H3 mast cells and murine peritoneal cells released serotonin after SEB stimulation in culture. Release of serotonin in RBL-2H3 cells depended on the concentration of SEB; an appreciable release was seen at 50 micrograms/ml. The release of serotonin was not due to cell death. Serotonin release could be enhanced by bradykinin but not by vasoactive intestinal peptide, substance P, lipopolysaccharide from Salmonella typhimurium, the calcium ionophore A23187, acetylcholine, adenosine, 5-hydroxyeicosatetraenoic acid, indomethacin, or phorbol myristate acetate. SEB bound directly to the membrane of RBL-2H3 mast cells, and the SEB-binding site, the presumptive receptor, appeared to be a protein. The SEB receptor could not be capped under membrane-capping conditions, and serotonin release could not be enhanced by attempts to cross-link the receptor. These results suggest that mast cells may be an important cell type involved in SEB toxicosis and that release of serotonin may be enhanced by activation of the kinin-kallikrein system.

Acetylcholine↗
PubMed1990

Basichondrocranium anomalies in adult Chiari type I malformation: a morphometric study.

The purpose of this study was to determine the frequency of anomalies of the basichondrocranium in a series of 42 patients with Chiari type I malformation compared with a control group of 46 subjects. Sixteen patients also had syringomyelia. Linear, angular and posterior fossa surface area measurements were taken on conventional lateral skull x-rays. Posterior fossa volume was estimated by CT scanning. In patients there was shortening of clivus length, Twining-opisthion distance and Chamberlain's line. Basal and Boogard angles were enlarged. The size of the posterior fossa was smaller in patients than in controls. Only 10 (23.8%) patients had no evidence of occipital dysplasia. When discriminant analysis was applied to the data, the most discriminative variables were posterior fossa area and clivus length which allowed accurate identification of 76% of patients as belonging to the patient group and 79% of controls as belonging to the control group. These findings prove that under-development of the basichondrocranium with a small size of the posterior fossa is an outstanding feature in adult Chiari type I malformation, and support the hypothesis that tonsillar ectopia is secondary to the disproportion between the posterior fossa and the cerebellum, which is forced to grow into the cervical spinal canal.

Adult↗
PubMed1990

In-111 labeled leukocyte scintigraphy in a case of multifocal candidiasis.

The value of indium-111 labeled leukocyte scintigraphy for the diagnosis of infection in the general population is well documented; there is less information available on its role in the evaluation of the immunocompromised patient. In this study, leukocyte scintigraphy was performed on a 31-year-old immunocompromised woman who had a possible intra-abdominal abscess. No abscess was detected, but intense oral, esophageal, gastric, and vaginal uptake was observed. Candida infection was histologically confirmed at all four sites.

Adult↗
PubMed1990

Indium-111-labeled leukocyte scintigraphy in hemodialysis access-site infection.

Bacterial sepsis, a significant complication of chronic hemodialysis, is generally the result of infection at the vascular access site. We retrospectively reviewed the utility of indium-111-(111In) labeled autologous leukocyte scintigraphy in 26 patients (30 scans) with synthetic vascular grafts, on chronic hemodialysis, in whom hemodialysis access site infection was a diagnostic consideration. Leukocyte scintigraphy correctly identified all fifteen access-site infections; there was one false-positive study, for an overall sensitivity and specificity of 100% and 93%, respectively. Of particular significance is the fact that in nine (60%) of the fifteen access-site infections, physical examination was normal. Our data indicate that 111In-labeled leukocyte scintigraphy is a useful procedure for the diagnosis of hemodialysis access-site infection, and it is especially valuable when physical examination of the access site is normal.

Adult↗
PubMed1990

Appearance of acute gouty arthritis on indium-111-labeled leukocyte scintigraphy.

Indium-111-labeled leukocyte scintigraphy was performed on a 66-yr-old male with polyarticular acute gouty arthritis. Images revealed intense labeled leukocyte accumulation in a pattern indistinguishable from septic arthritis, in both knees and ankles, and the metatarsophalangeal joint of both great toes, all of which were involved in the acute gouty attack. Joint aspirate as well as blood cultures were reported as no growth; the patient was treated with intravenous colchicine and ACTH for 10 days with dramatic improvement noted. Labeled leukocyte imaging, repeated 12 days after the initial study, revealed near total resolution of joint abnormalities, concordant with the patient's clinical improvement. This case demonstrates that while acute gouty arthritis is a potential pitfall in labeled leukocyte imaging, in the presence of known gout, it may provide a simple, objective, noninvasive method of evaluating patient response to therapy.

Acute Disease↗
PubMed1990

[Treatment of bladder instability using intravaginal electric stimulation (intrarectal)].

Fourteen patients (13 females, 1 male) with urinary incontinence from bladder instability were treated with intravaginal (intrarectal) electrical stimulation. Good results were achieved in 57.1% of the cases. The foregoing finding shows that intravaginal (intrarectal) electrical stimulation may constitute a therapeutic option in urinary incontinence from bladder instability.

Adolescent↗
PubMed1989

[Participation of bladder dysfunction in urinary incontinence after prostatectomy].

Twenty-four patients with post-prostatectomy urinary incontinence were submitted to clinical and urodynamic evaluation. The clinical evaluation analyzed urinary symptoms and included rectal examination of the prostate lodge, neurourologic examination (perineal sensitivity, anal tone, bulbocavernous reflex, voluntary control of anal sphincter). The urodynamic study consisted of flowmetry, cystomanometry, detrusor pressure/micturition flow test and videocystography. An unstable bladder was demonstrated in 62.5% of the cases. Bladder dysfunction was recognized in 75% of the cases. Involvement of the striated periurethral sphincter was demonstrated in no patient. The clinical data did not provide orientation. No relation was observed between the urodynamic data, type of surgery, and amount of prostate removed. The urodynamic data appear to have a prognostic significance.

Aged↗
PubMed1989

Acute effects of radiation therapy on indium-111-labeled leukocyte uptake in bone marrow.

We recently performed [99mTc]MDP bone and 111In-labeled leukocyte scintigraphy on a patient receiving radiation therapy to the lower cervical and upper thoracic spine. While the bone images revealed only minimally increased activity in the radiation port, leukocyte images revealed diffuse, intensely increased uptake in this same region. Radiation therapy should be included in the differential diagnosis of increased bone marrow activity on 111In leukocyte images.

Aged↗
PubMed1989

[Dysfunction of the contractile capacity of the detrusor muscle in post-prostatectomy urinary retention].

We report on 23 consecutive patients with urinary retention following prostatectomy for benign prostatic hypertrophy. The patients were clinically and urodynamically evaluated. Urodynamic work-up included flowmetry, cystomanometry, detrusor pressure-micturition flow test, and videocystography. The involvement of detrusor contractility in urinary retention was observed in 60.87% of the cases and was ascribable to lower urinary tract obstruction in 39.19%. These data permitted instituting correct treatment.

Aged↗
PubMed1986

A mouse model for the study of necrotizing enterocolitis.

A mouse model for the study of necrotizing enterocolitis is presented. It is a model of temporary intestinal ischemia and consists of occluding both superior mesenteric vessels with a bulldog clamp for varying periods of time. The resultant lesions resemble the intestinal lesions seen in necrotizing enterocolitis in respect to the gradual development of the necrotizing lesions and their patchy distribution. We also studied the effect of intravenous saline and low molecular weight dextran in preventing the development of these ischemic lesions. In moderate ischemia, saline and dextran show a similar protective effect, and in severe ischemia, both show a protective effect, with dextran being more effective than saline.

Animals↗
PubMed1985

Cognitive deficits in adolescents who developed diabetes early in life.

A comprehensive battery of neuropsychological tests was administered to 125 adolescents with a history of insulin-dependent diabetes, and to 83 demographically similar nondiabetic control subjects. To test the hypothesis that developing this disease early in life greatly increases the risk of manifesting significant cognitive impairments, diabetic subjects were assigned to an "early-onset" (diagnosis before age 5 years) or a "later-onset" subgroup. Results showed that subjects with early onset of diabetes performed more poorly than either subjects with later onset of diabetes or nondiabetic control subjects on virtually all tests, including measures of intelligence, school achievement, visuospatial ability, memory, motor speed, and eye-hand coordination. Moreover, multiple regression analyses demonstrated that the age at onset and the duration of diabetes seem to affect neuropsychological functioning in very different ways. The duration of the disease best predicted performance on those tests requiring highly overlearned, primarily verbal, skills whereas the age at onset best predicted scores on tests requiring the ability to process relatively unfamiliar, typically nonverbal, information in novel ways. Although the etiology of these deficits remains unclear, there is a possibility that they are secondary to mild brain damage that develops as a consequence of multiple episodes of serious hypoglycemia early in life.

Adolescent↗
PubMed1984

Secular change in growth of native children and adolescents at high altitude Huancayo, Peru (3,280 meters).

Stature and weight of native children, adolescents, and adults at Huancayo , Peru (3,280 meters), were measured in 1977, 1978, and 1982 and compared with mean statures and weights reported in previous studies. The data indicate that in Huancayo there has been a secular increment in child stature, sitting height, and weight from 1937 to 1978-1982. The observed changes in stature are related to a proportionally greater increment in leg length relative to trunk length. It is concluded that the observed secular increase in body size reflects changes in the standard of living and a greater influx of nonnative populations, which are usually characterized by greater stature than natives.

Adolescent↗
PubMed1981

The liver and immunoregulation of neuroblastoma growth.

C1300 neuroblastoma, like human neuroblastoma, elicits an immune response in its host and as a result provides an animal model in which to study the enigmatic behavior of this common childhood tumor. Since the liver is a favored site for neuroblastoma metastasis, especially the favorably regressing IV-S stage, and since the liver is a known producer of immunoregulatory factors, this study report a systematic assessment of liver cell tumor cell interaction, the effect on tumor immunogenicity, and the potential for tumor growth control. Immunization-excision-challenge assays in 120 A/J mice with C1300 demonstrate the tumor to be antigenic; but in a second experimental sequence with 120 mice, normal whole liver cells were admixed with C1300 tumor cells in vitro and incubated for one hour prior to animal innoculation. The immunogenicity is dramatically minimized in the admixture group when compared with controls (antigenic ratio = 1.67 versus 3.07, p less than .02). However, if prior to such liver cell-tumor cell admixture the liver cells are sonicated and the lysate ultracentrifuged, a contrasting result is obtained. In 4 additional experiments utilizing 120 mice, the tumor cell is rendered a more potent immunogen following soluble fraction admixture (antigenic ratio = 1.99 versus 1.56, p less than .05). These data suggest that such whole cell and subcellular soluble factor immunoregulatory interactions are operative in determining immunogenicity of a tumor innoculation. We speculate that the progression or regression of clinical neuroblastoma within the liver may be similarly influenced since a host-tumor interaction depends on eliciting an antitumor response to an antigenic stimulus.

Animals↗