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Biomedical subjects

C de la Rosa

Publications and source records attributed to C de la Rosa.

At least 19 recordsLinked to original sources

Pediatric AIDS-associated lymphocytic interstitial pneumonia and pulmonary arterio-occlusive disease: role of VCAM-1/VLA-4 adhesion pathway and human herpesviruses.

Because the mechanisms of lymphocyte accumulation in the lungs of children with AIDS-associated lymphocytic interstitial pneumonia (LIP) are unknown, we studied the relative contributions of known adhesion pathways in mediating lymphocyte adherence to endothelium and the potential role of human herpesviruses in the expansion of these lesions. LIP was characterized by lymphoid hyperplasia of the bronchus-associated lymphoid tissue (BALT) and infiltration of the pulmonary interstitium with CD8(+) T lymphocytes. In some individuals there was expansion of the alveolar septae with dense aggregates of B lymphocytes, many containing the Epstein-Barr viral (EBV) genome. Patients with concurrent EBV infection also demonstrated large-vessel arteriopathy characterized by thickening of the intimae with collagen and smooth muscle. Venular endothelium from the lung of children with LIP, but not uninflamed lung from other children with AIDS or lung from children with nonspecific pneumonitis, expressed high levels of vascular cell adhesion molecule-1 (VCAM-1) protein. In turn, inflammatory cells expressing very late activation antigen-4 (VLA-4), the leukocyte ligand for VCAM-1, were the predominant perivascular infiltrate associated with vessels expressing VCAM-1. Expression of other endothelial adhesion molecules, including intracellular adhesion molecule-1 and E-selectin, was not uniformly associated with LIP. Using a tissue adhesion assay combined with immunohistochemistry for VCAM-1, we show that CD8(+) T cell clones that express VLA-4 bind preferentially to pulmonary vessels in sites of LIP: vessels that expressed high levels of VCAM-1. When tissues and cells were pretreated with antibodies to VCAM-1 or VLA-4, respectively, adhesion was inhibited by >/=80%. Thus, infiltration of alveolar septae with CD8(+) T cells was highly correlative with VCAM-1/VLA-4 adhesive interactions, and focal expansion of B cells was coincidental to co-infection with EBV.

AIDS-Related Opportunistic Infections↗

Helicobacter pylori, hyperammonemia and subclinical portosystemic encephalopathy: effects of eradication.

BACKGROUND/AIMS: An involvement of Helicobacter pylori in the development of hepatic encephalopathy in cirrhotic patients has been proposed, but data confirming such an association are lacking. This prospective study aimed to assess whether ammonia levels and indicators of subclinical portosystemic encephalopathy were influenced by H. pylori status in a series of 62 cirrhotic patients. The effects of H. pylori eradication on such parameters were also investigated. METHODS: Fasting blood ammonia levels, mental state, number connection test, flapping tremor, and EEG tracings were recorded at baseline, and in H. pylori-positive patients (as diagnosed by rapid urease test and 14C-urea breath test) these parameters were reassessed 2 months following eradication therapy. RESULTS: In this series of non-advanced cirrhotic patients, the prevalence of H. pylori infection was 52%. No significant differences were observed between H. pylori+ and H. pylori- cases with respect to fasting venous blood ammonia concentration (47+/-24 vs. 43+/-22 micromol/l) or to the remaining parameters assessing portosystemic encephalopathy. In addition, H. pylori eradication failed to induce any significant variation in either fasting blood ammonia levels (from 45+/-23 to 48+/-26 micromol/l) or neurologic disturbances. CONCLUSION: These results indicate that H. pylori infection is not a major contributing factor to either fasting blood ammonia levels or parameters assessing subclinical portosystemic encephalopathy in patients with non-advanced liver cirrhosis.

Aged↗

Vaccination schedules to raise antibody concentrations against epsilon-toxin of Clostridium perfringens in ewes and their triplet lambs.

The objective of this experiment was to compare vaccination schedules for ewes and their lambs to raise antibody concentrations to epsilon-toxin of Clostridium perfringens, the causative agent of enterotoxemia. Half of 200 Finnsheep x Dorset ewes were vaccinated with C. perfringens type D toxoid vaccine 3 wk before lambing. Serum samples were obtained from 20 ewes that were to be vaccinated and 20 ewes that would remain unvaccinated before treatment and at wk 2, 1, and 0 before the start of lambing. Antibody concentrations in sera of unvaccinated ewes remained at 2 IU/mL, but they peaked in vaccinated ewes at 15 IU/mL by wk 1 before lambing. Lambs from each of the first 13 and the first 14 sets of triplets from vaccinated and unvaccinated ewes, respectively, received one of three vaccination treatments: no vaccine (control), vaccination on d 1 and 21 of age, or vaccination on d 21 and 42 of age. Antibody concentrations declined in sera of vaccinated ewes from 8.5 IU/mL immediately after lambing to 3 IU/mL 12 wk later. Vaccination of lambs did not increase sera antibody concentration. However, prepartum vaccination of ewes significantly increased lamb antibody concentrations (19 IU/mL) compared with lambs reared by unvaccinated ewes (2 IU/mL). Vaccination of ewes resulted in lambs with higher antibody concentrations until wk 10 postpartum. Concentrations declined to .6 IU/mL in all lambs at 12 wk. Because concentrations of .2 IU/mL may be protective, these results indicate that vaccination of ewes before lambing imparts passive protection in lambs to 12 wk of age, whereas vaccination of young lambs provides no added protection.

Animals↗

Survival of Staphylococcus aureus in oral administration liquid medicaments and influence of count medium on survival.

The survival of Staphylococcus aureus was studied in 30 oral administration liquid medicaments (15 syrups and 15 solutions) to determine the effectiveness of the preservatives, the influence of the culture medium used in the enumeration of the surviving microorganisms, and the loss of the enzyme coagulase, phosphatase, DNase (deoxyribonuclease), and thermonuclease. Samples were inoculated with 6.3-6.5 x 10(5) viable cells per milliliter and were stored at room temperature for 60 days. Aliquots were taken for analysis at 0, 15, 22, 30, and 60 days after samples were inoculated. The enumeration of S. aureus was made by most probable number method (MPN) with six liquid culture media: triptone soy (TS), TS with 10% NaCl (TSS), TS and TSS with 0.2% catalase, Mannitol salt, and Tellurite-mannitol-glycine. The survival of S. aureus was lower in solutions than in syrups, decreased with the storage time, and depended on the culture medium utilized in the enumeration. Nonselective media were more sensitive than selective ones; that is, a better percentage of recovery was achieved with TS and the catalase medium. The preservative was effective in 93.3% of the samples. Coagulase was the most stable enzyme and phosphatase, DNase, and thermonuclease disappeared during the storage period.

Administration, Oral↗

[Gastric secretion after vagotomy at different levels].

It is well known that all the different procedures of vagotomy have a great variability in the clinical results and a high incidence of positivity in the Hollander's tests, this probably due to the arrangement of the vagus nerves in the low third of the esophagus and its connection with the mienteric plexus. In a group of ten dogs with a gastric fistula we obtained first a sufficient number of assays with vagal stimulation, later on vagotomy was done at the level of the esophago-gastric union (EGU), getting a decrease in the gastric secretion of hydrochloric acid of 64%, afterwards a second section of the vagus nerves was practiced, five centimeters above the EGU having an inhibition of 90% and finally 95% was attained when the vagotomy was done 15 centimeters above the EGU. It is concluded that it is needed a long vagal resection of the last ten centimeters, instead of the classic section of the nerve at the gastroesophagic union; it is the same case with a parietal cell mass vagotomy.

Animals↗

[Treatment of extreme obesity].

23 patients whose weight varied from ninety-eight to 220 kilos were subjected to four different types of jejuno-ileal by pass operations: terminal-lateral (14 X 4) in three, terminal-terminal (14 X 4) in fifteen, (12 X 8) in two, and (10 X 8) in three. The defunctionalized intestine was anastomized to the transverse colon. Liver, jejenum and ileal biopsies as well as profilactic apendectomy were performed in all the cases along with colecistectomy when possible. All our patients were carefully studied in the pre and postoperative periods. The postoperative follow-up varied from 16 to 72 months, during which time a short and long-term mortality of 8.6% was observed. In eight patients it was necessary to reestablish normal intestinal transit for one or two reasons: rapid weight loss or total lack of patient cooperation. During the first few months post-op, diarrhea, nausea, vomiting, loss of apetite, weakness, inactivity, depression, electrolyte anormalities, anemia and increased hepatic esteatosis were the clinical and pathological findings most frequently encountered. With the cooperation of the patient it is possible to correct all these alterations: it is for this reason that the importance of right patient selection is emphasized. The rate of post-operative weight loss varied from patient to patient with an ideal weight being achieved between 18 and 24 months after the operation. Only in those patients reoperated upon to establish normal intestinal transit was the lost weight recuperated. Along with rigid patient selection, the success of this operation depends upon interspecialty teamwork during the preoperative evaluation as well as the follow up period in order to resolve the intricate physio-pathological problems that so frequently arise.

Adolescent↗