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Biomedical subjects

J L Pacheco

Publications and source records attributed to J L Pacheco.

10 recordsLinked to original sources
PubMed1998

Nitric oxide modulates respiratory-related neural activity in the isolated brainstem of the bullfrog.

The effects of nitric oxide (NO) on respiratory-related neural activity were investigated using the isolated brainstem preparation from bullfrogs (Rana catesbeiana). Addition of the NO donor, sodium nitroprusside (SNP), or the amino acid precursor for NO synthesis, L-arginine (L-Arg), produced significant increases in respiratory-related burst frequency. Inhibition of nitric oxide synthase (NOS) with N(omega)-nitro-L-arginine (L-NA), a non-selective NOS inhibitor, 7-nitro indazole (7-NI), reversibly abolished burst activity. These results suggest that production of NO, probably via neuronal NOS (nNOS), provides a facilitatory input to the respiratory central pattern generator (CPG) in the amphibian brainstem. Endogenous production of NO may be a necessary inter- or intracellular messenger for neurotransmission and/or neuromodulation of central respiratory drive to motor effectors in the bullfrog.

Animals↗
PubMed1998

Vena cava vascular reconstruction during orthotopic liver transplantation: a comparative study.

The aim of this study was to evaluate the influence of preserving the recipient's inferior vena cava during orthotopic liver transplantation (OLT) on hemodynamic alterations, blood component requirements, postoperative liver and renal function, as well as vascular-related complications. A total of 122 OLTs was studied. In 35 OLTs, venovenous bypass (BP) was used; in 35 OLTs, bypass was not used (NBP); and in 52 OLTs, the recipient's inferior vena cava was preserved (PC). Preservation of the inferior vena cava means that venous return is not compromised at any time during transplantation. The time of hepatectomy was not different among the three groups (208 +/- 11, 188 +/- 13, and 194 +/- 6 minutes for BP, NBP, and PC, respectively); however, the total operating time was significantly lower in PC patients (492 +/- 24, 459 +/- 18, and 419 +/- 10 minutes for BP, NBP, and PC, respectively; P = .004, ANOVA). Blood component requirements were significantly lower in patients with PC. For red blood cells, these were 15.2 +/- 2.6, 16 +/- 3.4, and 7.1 +/- 1.5 units for BP, NBP, and PC, respectively (P = .009, ANOVA), and for fresh-frozen plasma, these were 5.4 +/- .7, 5.8 +/- .9, and 3 +/- .4 L for BP, NBP, and PC, respectively (P = .005, ANOVA). Postoperative liver and renal function did not differ among the three groups. The incidence of surgical complications (bleeding and vascular) was similar. Preservation of the inferior vena cava of the recipient significantly reduces the magnitude of OLT.

Blood Transfusion↗
PubMed1995

Short-term outcome analysis of a randomized study comparing laparoscopic vs open colectomy for colon cancer.

The authors examined the impact of the laparoscopic approach on the early outcome of resected colon carcinomas. The role of laparoscopic techniques in the treatment of colon carcinomas is questionable. Previous studies have suggested technical feasibility of surgical resections of these cancers by laparoscopic means and have implied a benefit to laparoscopic technique for patients undergoing colorectal resections. A prospective, randomized study was conducted comparing laparoscopic assisted colectomy (LAC) open colectomy (OC) for colon cancer. We present the preliminary results in relation to the short-term outcome and judge the feasibility of the laparoscopic procedure to as a way of performing accurate oncologic resection and staging. Benefit has been demonstrated with LAC in this setting. Passing flatus, oral intake, and discharge from hospital occurred earlier in LAC- than OC-treated patients. The mean operative time was significantly longer in the LAC group than in the OC group. The overall morbidity was significantly lower in the LAC group. No significant differences were observed between both groups in the number of lymph nodes removed or the pathological stage following the Astler-Coller modification of the Dukes classification. The laparoscopic approach improves the short-term outcome of segmental colectomies for colon cancer. However, the further follow-up of these patients will allow us to answer in the near future whether or not the LAC may influence the long-term outcome.

Adenocarcinoma↗
PubMed1990

Allatinhibin, a neurohormonal inhibitor of juvenile hormone biosynthesis in Manduca sexta.

The corpora allata (CA) of Manduca sexta larvae become incapable of synthesizing juvenile hormone (JH) early in the wandering stage of the last larval stadium. They then switch to the synthesis and release of JH acids. This change in CA activity is induced by an inhibitory factor--allatinhibin (AI)--from the brain. AI activity is present in the fifth (Vth) instar hemolymph from about Day 4 (day of wandering) until Day 7 (early prepupa). CA of early fifth instar larvae (uninhibited) incubated in vitro with brain-corpora cardiaca-corpora allata (Br-CC-CA) complexes or brain alone from wandering larvae are inhibited as demonstrated by bioassay. On the basis of these observations, an in vitro-in vivo assay for AI was developed. Br-CC-CA or Br alone were first incubated in tissue culture medium overnight. Day 0 (0d) Vth instar CA incubated for 16 hr in such medium will lose the ability to induce a larval molt in allatectomized 0d IVth instar larvae if the medium contained AI activity. The highest AI activity was exhibited by the medium obtained from incubations of brain from wandering larvae whereas the medium from incubation of 0d Vth and 0d pupal brains showed no AI activity. Dose-response data show that AI is active at 0.03 brain equivalents/200 microliters medium. CA must be exposed to AI for 12-16 hr for manifestation of inhibition. AI causes a stable inhibition of CA. AI is heat-labile, protease sensitive, has a molecular size between 1.0 and 3.5 kDa, and is clearly distinct from the allatostatins described by others.

Animals↗
PubMed1990

A somatotypical study of the geographic variations between two Spanish populations.

Morphological differences between university students from Bilbao (Basque Country) and Madrid (Spanish Meseta) have been studied. The sample sizes are 99 and 119, respectively, and the age ranges from 18 to 22 years. The main differences between the two groups under study were observed concerning the skinfold thicknesses. Body weight, stature and limb girths do not show remarkable differences. The physiques, as judged from anthropometric somatotypes, differ in the first component (endomorphy): Basques have higher values.

Adult↗
PubMedDate not supplied

[Indomethacin in the treatment of acute cholecystitis and biliary colic].

Prostaglandins GE2 produces on the gallbladder a rise in intraluminal pressure, an increase in in intraluminal secretion, improves gallbladder contraction and decreases its absorption capacity. In this study, patients who received indomethacin twice a day by rectum, showed a significant reduction in volume and area of gallbladder after 24 and 48 hours (P < 0.05). The gallbladder volume after 24 hours had SEM 9.13 cm3, 95% CI 55.28 + 73.49 (P < 0.05). Score pain reduction after 24 hours was also significant (P < 0.001). The patients who underwent the classical Baralcina treatment of one IV vial BID showed a reduction in diameter and area of gallbladder but this was not statistically significant (P < 0.10). Reduction of volume at 24 hours was SEM 5.34 cm3 95% CI - 64.72 + 76.60 P 0.10 NS; and at 48 hours SEM 3.5 cm3, 95% CI 59.52% + 66.52 P 0.40. Score pain reduction was only significant at 48 hours P 0.001. The number of patients without pain at 24 hours was significantly higher in the indomethacin group ESP 0.21; 95% CI 0.46 + 0.88 P 0.001. In conclusion indomethacin is a useful medication in the treatment of acute cholecystitis and biliary colic due to its anti-prostaglandin effect on the gallbladder.

Acute Disease↗
PubMedDate not supplied

[Value of emergency endoscopy in upper digestive hemorrhage].

The present study analyses 197 patients with acute upper GI bleeding; 161 men and 36 women, with mean age of 48 years (range, 2-89). Endoscopy showed a sensitivity of 98.35%; specificity of 33.33%; predictive positive value 94.71%; predictive negative value 62.50%; false positive rate 5.29% and false negative rate 37.50%. 8.93% of patients had been bleeding by two lesion and 0.57% had three or more lesion bleeding simultaneously. 42.65% of bleeding patients had other potential bleeding lesions: 32.96% had one 8.02% two and 1.67% more than three. 5.83% were Forrest I-A; 14.56% I-B; 74.76% II and 4.85% Forrest III. The greatest mortality rate was associated with high volume of transfused blood p < 0.05. No statistical differences was demonstrated between medical and surgical treatment (p > 0.05). The general mortality rate without intensive care was 12.37%; for peptic ulcer 9.18%; congestive gastritis 4.76%; esophageal varices 70% and acute gastritis 6.06%.

Adolescent↗