Biomedical subjects

J A Rodriguez

Publications and source records attributed to J A Rodriguez.

At least 55 records · Page 3Linked to original sources

PubMed2000

Video-assisted thoracoscopic surgery for children with stage II empyema.

Children with stage II empyema often fail traditional medical management, frequently succumbing to the effective albeit morbid clutches of thoracotomy. Video-assisted thoracoscopic surgery (VATS) has been recently introduced as a viable and potentially less morbid alternative to open thoracotomy. We review our VATS experience in children with empyema, assessing surgical outcome. Between August 1996 and March 1999, 13 patients at our institution with stage II empyema that did not respond to conventional medical management underwent a modified VATS with decortication. Data from retrospective chart review reflects intraoperative findings and postoperative course, including average time to defervescence, removal of thoracostomy tube, and hospital discharge. VATS was completed in all 13 patients. All intraoperative cultures of pleural fluid and fibrinopurulent debris obtained at VATS showed no growth. The average time to defervescence was 2.2 days (range, 0-4 days) and to removal of thoracostomy tube 3.6 days (range, 2-5 days). Average total chest tube days in patients with pre-VATS thoracostomy (n = 6) was 14.5 days (range, 8-37 days) versus 3.1 days (range, 2-5 days) in patients (n = 7) who underwent primary VATS (t test, p < 0.05). The average time to surgical discharge after VATS was 5.8 days (range, 3 to 19 days). All patients were well on follow-up clinic visits without delayed complications. VATS can be performed safely and effectively in children with stage II empyema, thus avoiding the morbidity of open thoracotomy and decortication. Importantly, early application of VATS significantly relieves patients of unnecessary days of thoracostomy drainage.

Adolescent↗

PubMed2000

Zinc, copper, and metallothionein metabolism after jejunoileal bypass surgery or small bowel resection in rats.

Liver dysfunction is a frequent complication of jejunoileal bypass (JIB) surgery, a procedure commonly used until recently to treat morbid obesity. It has been suggested that liver failure in JIB patients is due to bacterial overgrowth and translocation from the bypassed intestine. Because invading microorganisms cause hepatic inflammation these experiments evaluated zinc, copper, and metallothionein (MT) in two experimental rat models of intestinal surgery to determine whether their distribution in plasma and tissues was similar to the highly characteristic pattern observed during an inflammatory response. In the JIB rat model 90 per cent of the small intestine was isolated from the flow of digesta but remained viable in the abdominal cavity. In the small bowel resection (SBR) model 90 per cent of the small intestine was removed and the remaining intestine was resected. Data collected 21 days after surgery showed decreased growth rate and plasma zinc in the SBR and JIB rats that was significantly improved by supplemental zinc. All other measures of zinc, copper, and MT metabolism in the SBR rats were similar to those of controls. In JIB rats, however, liver copper, MT protein, and MT mRNA were significantly elevated, and a high proportion of the intracellular zinc and copper was associated with MT. The pattern of zinc, copper, and MT distribution in systemic circulation and liver of JIB rats suggests hepatic inflammation superimposed on low zinc and copper status. Lack of a similar response in the SBR rats confirms the involvement of the bypassed intestinal segment and supports the hypothesis that bacterial overgrowth and translocation are responsible for liver inflammation and dysfunction in JIB patients.

Animals↗

PubMed1999

Decreased GAP-43/B-50 phosphorylation in striatal synaptic plasma membranes after circling motor behavior during development.

We evaluated the in vitro phosphorylation of the presynaptic substrate of protein kinase C (PKC), GAP-43/B-50 and the PKC activity in the striatum of rats submitted to a circling training (CT) test during postnatal development. Motor activity at 30 days of age, but not at other ages, produced a unilateral reduction (-29.5%; p<0.001) in the level of GAP-43/B-50 endogenous phosphorylation in the contralateral striatum with respect to the ipsilateral side, while non-trained control animals did not show asymmetric differences. Compared to controls, the contralateral striatum of trained animals also showed a significant reduction (-29.3%; p<0. 001) in the incorporation of 32P-phosphate into GAP-43. This decreased in vitro GAP-43 phosphorylation was seen at 30 min, but not immediately after circling motor behavior. This contralateral change in GAP-43 phosphorylation correlated with the running speed developed by the animals [(r=0.9443, p=0.0046, n=6, relative to control group) and (r=0.8813, p=0.0203, n=6, with respect to the ipsilateral side of the exercised animals)]. On the contrary, GAP-43/B-50 immunoblots did not show changes in the amount of this phosphoprotein among the different experimental groups. Back phosphorylation assays, performed in the presence of bovine purified PKC, increased the level of GAP-43/B-50 phosphorylation in the striatum contralateral to the sense of turning [(+22%; p<0.05, with respect to ipsilateral side of the same trained group) and (+21%; p<0.05, relative to control group)]. Taken together, these results demonstrate that the activity developed in the CT test induces a reduction in the phosphorylation state of GAP-43/B-50 in the specific site for PKC. We conclude that general markers of activity-dependent neuronal plasticity are also altered in the same period that long-lasting changes in striatal neuroreceptors are triggered by circling motor behavior.

Animals↗

PubMed1999