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Biomedical subjects

G Ramirez

Publications and source records attributed to G Ramirez.

264 records · Page 15Linked to original sources
PubMedDate not supplied

Gastric sarcoidosis.

Sarcoidosis of the gastrointestinal tract is uncommon even though involvement of the liver, spleen, and adenopathy are becoming recognizable entities on computed tomography (CT). Involvement of the stomach, the most common site of sarcoidosis of the gastrointestinal tract, is usually associated with pulmonary disease. The radiologic appearances of gastric involvement are variable. Positive biopsies may be obtained in a radiologically normal stomach. Ulceration resembling peptic ulcer disease may occur, and mucosal enlargement may be minor, diffusely nodular, or significant enough to mimic Menetrier disease. In its most dramatic form, a linitis plastica appearance resembling scirrhous carcinoma has been reported.

Adult↗
PubMedDate not supplied

Alcohol, hepatic sinusoidal microcirculation, and chronic liver disease.

According to the "intact cell hypothesis," ethanol (EtOH) primarily targets nonparenchymal hepatic sinusoidal and perisinusoidal cells, thereby promoting sinusoidal capillarization, which impairs microcirculatory exchange of nutrients and wastes, promotes tissue fibrosis, and only indirectly damages hepatic parenchyma. To test this hypothesis, sinusoidal ultrastructure and hepatic lymph flow and protein composition were examined in rats up to 16 weeks after intragastric EtOH (36% calories)-high fat infusion (Tsukamoto-French model) (TF). The findings were compared to dietary controls and interpreted in light of restricted transsinusoidal protein movement observed in patients with alcoholic cirrhosis. In vitro, alterations in rat hepatic sinusoidal endothelial cell (RSE) morphology, proliferative index, and transendothelial macromolecular permeability (Evans blue-albumin uptake into microcarrier beads) were determined after acute and more chronic exposure to 0.1%-5 vol% EtOH. TF displayed 75% increased liver size, perisinusoidal collagenosis, and basal lamina deposition, ascitic fluid, and doubling of hepatic lymph liquid and protein flux. In vitro, 1% EtOH retracted RSE cell margins, enhanced transendothelial Evans blue-albumin flux and suppressed proliferative index. Thus, high EtOH concentration, clinically attainable in the portal blood during an alcoholic binge, both in vivo and in vitro, promotes early structural and functional alterations in sinusoidal endothelium, which over time may be responsible for progressive restriction of free intrahepatic exchange of liquid, macromolecules, and migrating immune cells.

Animals↗
PubMedDate not supplied

AIDS, alcohol, endothelium, and immunity.

Analogies are drawn between important unknowns in AIDS and alcohol research, related to underlying common pathogenetic mechanisms, immunodysregulation, cofactors, and prominent vascular manifestations. The central role of the blood and lymphatic vasculatures and specifically their endothelial lining in many facets of the immune response is reviewed. Evidence is presented that both alcohol and HIV (as well as other coinfecting viruses in AIDS) target and alter endothelial cells and the angiogenic process. These concepts are further illustrated by a serendipitous viral epidemic among rats on continuous long-term alcoholic and control nonalcoholic diets, where synergism between alcohol and virus appeared to underlie multiple vascular proliferative lesions in the liver. In AIDS and alcoholism/alcoholic liver disease (ALD), the prominent features of dysregulated angiogenesis point to the endothelium as a key player in pathogenesis of these seemingly disparate disorders and potentially in immunomodulation.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Abdominal manifestations of sarcoidosis. CT appearances.

Sarcoidosis frequently involves the abdomen, although imaging studies often fail to demonstrate disease. The most common computed tomography (CT) findings in abdominal sarcoidosis are hepatosplenomegaly and retroperitoneal adenopathy, followed by focal low-attenuation lesions of the liver and spleen. Other abdominal viscera are involved infrequently. We present four cases of abdominal sarcoidosis demonstrating a range of CT findings.

Adult↗
PubMedDate not supplied

Latent infection of epidermal Langerhans cells in HIV-positive individuals.

Epidermal cell suspensions obtained from 3 symptom-free HIV-positive individuals were cultured and marked with monoclonal antibodies for the HIV proteins p15, p24 and gp120 in the alkaline phosphatase anti-alkaline phosphatase staining technique. For 2 individuals, cells were positive after 3 days in culture, and for the third, after 4 days. Supernatant from one of the cultures infected allogeneic peripheral blood mononuclear cells. We conclude that epidermal Langerhans cells from symptom-free HIV-positive individuals are latent-infected and are able to produce and release HIV.

Adult↗
PubMedDate not supplied

Magnetic resonance imaging of the normal equine brain.

The purpose of this investigation was to define the magnetic resonance (MR) imaging appearance of the brain and associated structures of the equine head. MR images were acquired in oblique dorsal (T2-weighted), sagittal (T1-weighted), and transverse planes (T2-weighted), using a magnet of 1.5 Tesla and a human body coil. Relevant anatomic structures were identified and labeled at each level. The resulting images provided excellent anatomic detail of the cranioencephalic structures. Annotated MR images from this study are intended as a reference for clinical imaging studies of the equine head, specially in the diagnosis of brain diseases in the horse.

Animals↗
PubMedDate not supplied

The validity of health claims on the World Wide Web: a systematic survey of the herbal remedy Opuntia.

PURPOSE: The World Wide Web has become a significant source of health information for the public, but there is concern that much of the information is inaccurate, misleading, and unsupported by scientific evidence. To explore this issue, the validity of health claims for the herb Opuntia on the World Wide Web was analyzed. DATA SOURCES: From December 1998 to May 1999, health claims were identified from Web sites utilizing nine search engines. A corresponding search was conducted of the scientific literature. Search terms included common and botanical names for Opuntia. INCLUSION AND EXCLUSION CRITERIA: Nutritional support guidelines for herbs were used to identify claims from relevant sites. Scientific studies included established methodological designs with no restrictions on source, language, type of subjects, or dosage forms for Opuntia. DATA EXTRACTION METHODS: A checklist of significant information was prepared for Web sites and scientific studies. The quality of scientific studies was assessed with two instruments, the Jadad and the Journal of the American Medical Association (JAMA) scales. DATA SYNTHESIS: Validity of health claims on Web sites was compared with scientific reports. Searches retrieved 184 Web sites, 98 with health claims and 51 with research studies. Only 34% of the claims were addressed in the scientific literature, and evidence was conflicting or contradictory. For human studies, none met the criteria for high quality as determined by the Jadad and JAMA scales. MAJOR CONCLUSIONS: The majority of health claims were based on folklore or indirect scientific evidence and could not be validated by scientific research. This suggests a need to check the validity of herbal information on the World Wide Web.

Drug Information Services↗
PubMedDate not supplied

Phase II study of 5-azacytidine in solid tumors.

One hundred and seventy-seven patients were evaluated after therapy with 5-azacytidine using a dose of 1.6 mg/kg/day X 10 days followed by a maintenance regimen. One hundred and forty-eight of the patients received the drug by rapid iv infusion and 29 received the drug daily by and infusion that lasted between 18 and 24 hours. Hematologic toxicity was significant but transient in both groups. Nausea was severe using the rapid iv infusion and minimal with the slow infusion. Antitumor effect was seen in 17% of the evaluable patients with carcinoma of the breast and 21% of the patients with malignant lymphomas. Occasional responses were seen with a variety of other solid tumors. The responses were transient, and clinically, resistance to 5-azacytidine appeared to develop quite rapidly. No clear-cut difference was seen in response rates or duration of response between the two groups of patients. Cross resistance to other anticancer agents was not noted. It is believed that the drug is only of minimal value as a single agent in solid tumors using either of the methods of administration described.

Adolescent↗