PubMed Health⌕ Search

Biomedical subjects

M J Hernandez

Publications and source records attributed to M J Hernandez.

15 recordsLinked to original sources
PubMed2003

Liver transplantation for hepatocellular carcinoma in cirrhotic patients.

A consecutive series of 88 patients underwent transplantation for hepatocellular carcinoma with cirrhosis over a 7-year period. Liver transplantation was indicated because of the tumor in 75 cases (85.2%); tumor was an incidental finding in 13 cases (14.8%). One patient was retransplanted due to primary nonfunction. The perioperative mortality was 4.5%. Tumor recurrence was observed in seven patients (7.95%) with incidental tumor recurrence in one case. As in patients with known primary liver tumors pretransplant, a thorough follow-up is advisable to establish an early diagnosis of recurrence. The actuarial survival for nonincidental hepatocellular carcinoma at 1, 3, and 5 year was 92%, 77%, and 75%, respectively. The differences in actuarial survival between hepatitis C negative and positive hepatocellular carcinoma were not significant (log-rank test P=.27), though there was a clear improvement in results (94%, 85%, and 78% vs 90%, 71%, and 71%), at 1, 3, and 5 years meaning that HCV infection is an important prognostic factor. Although transplantation for HCC has the advantages of removing the tumor and the cirrhotic liver, it remains a controversial topic. In our experience patients showing lesions less than 5 cm or three or fewer lesions experience an equivalent survival to transplanted patients who do not have cancer.

Adult↗
PubMed1995

Is it worth using mechanical sutures in gastric surgery?

The use of stapler devices in gastrointestinal surgery has to be justified by the results. Since the cost of staplers is very high, their use should be followed by some advantage in the operating time, the morbidity or mortality rate or the postoperative stay. We have found a slight shortening in the operating time, but only statistically significant for Billroth I, and in the postoperative stay only for oesophagojejunostomies mechanically performed. We have not found any advantage with the other techniques and in the other parameters. Consequently, the use of staplers in gastric surgery should be carefully assessed by the surgeon for each patient in particular, and only used in those cases where a real benefit will be presumed.

Adult↗
PubMed1988

Colorectal cancer. The bases for a comprehensive follow-up.

The purpose of this article was to review the effectiveness of follow-up in patients with colorectal cancer submitted to curative treatment. A comprehensive follow-up involves rational initial management of the primary tumor, knowledge of prognostic factors, selection of the patient to be followed, determination of the time for follow-up, use of the most appropriate tests for early diagnosis of recurrence, and eventual curative treatment. The updated answers to all these questions are given through an extensive review of the world literature and confronted with the authors' experience of eight years of follow-up in a series of 170 colorectal cancer patients treated for cure. Although the future might be more promising, past world experience suggests only a few patients could be saved. It is concluded that there is no place for incomplete and disperse screening tests, and only comprehensive, intensive, and very well-coordinated follow-up programs should be undertaken if better results are hoped to be achieved.

Colonic Neoplasms↗
PubMed1985

The effect of lactacidemia on regional cerebral blood flow in the newborn dog.

The effects of lactacidemia on regional cerebral blood flow (rCBF) were determined in newborn dogs using [14C]iodoantipyrine autoradiography. Measurements of rCBF were made in normoxic, normocarbic, normotensive newborn dogs which were paralyzed and passively ventilated with 70% N2O and 30% O2. In 6 dogs rendered lactacidemic by the intravenous infusion of a 2% unneutralized L-lactic acid solution, arterial lactate concentrations increased by 268% while arterial pH decreased to a mean value of 7.105 +/- 0.051. Lactacidemia also increased mean arterial pCO2 values to 48.3 +/- 4.3 Torr from their original pre-infusion levels of 38.8 +/- 3.1 Torr. Although there were apparent increases in rCBF ranging from 26 to 54% above control levels, upon correction of each region's blood flow values for changes in arterial pCO2, there were no statistically significant differences between rCBF in the control and experimental animals. These results suggest that lactacidemia does not directly alter the cerebral circulation of the normoxic newborn dog.

Acidosis↗
PubMed1983

Regional cerebral blood flow, cerebral blood velocity, and pulsatility index in newborn dogs.

A technique employing a Doppler ultrasound probe to measure cerebral blood velocity was used to study the cerebral circulation continuously in 30 newborn mongrel dogs. Utilizing a transfontanelle approach, the probe was maintained in fixed position throughout a given experiment. In 20 animals, changes in systolic, diastolic, and mean cerebral blood velocity during hypo- and hypercarbia were directly correlated (P less than 0.01) with changes in regional cerebral blood flow (rCBF) determined in 12 regions of the brain by the [14C]iodoantipyrine autoradiography technique. In an additional 10 dogs, multiple determinations of systolic, diastolic, and mean blood velocity were made over a wide range of PaCO2 values and found to be directly related to the PaCO2 (P less than 0.001). These data suggest that changes in cerebral blood velocity are closely related to changes in cerebral blood flow. We also calculated the pulsatility index (PI) from the peak systolic and end diastolic velocities and found a poor, but direct (r = 0.28, P less than 0.05) relationship between the PI and PaCO2 rather than the indirect relationship, which has been suggested in published clinical studies. We conclude that the Doppler technique may be valuable in monitoring dynamic events of the neonatal cerebral circulation if a constant probe position is maintained. Our results suggest, however, that the PI is not a reliable index of cerebral vascular resistance.

Animals↗
PubMed1982

Selective reduction of blood flow to white matter during hypotension in newborn dogs: a possible mechanism of periventricular leukomalacia.

The cerebrovascular response of newborn animals to hypotension has not been defined on a regional basis. Using an autoradiographic technique employing 14C-iodoantipyrine as indicator, we studied the cerebral physiological responses of newborn dogs to hypotension induced by exsanguination or by administration of Escherichia coli endotoxin. Regional cerebral blood flow (rCBF) to all gray matter structures was preserved, even at mean arterial pressures as low as 20 mm Hg. In contrast, rCBF to periventricular and occipital white matter decreased significantly during severe hypotension. The selective hypoperfusion of cerebral white matter during severe hypotension may provide a mechanistic explanation for the pathogenesis of periventricular leukomalacia.

Animals↗
PubMed1981

Airway response to inhaled histamine in asymptomatic long-term marijuana smokers.

Bronchial challenge with histamine was used to assess bronchial reactivity in asymptomatic individuals who were long-term social smokers of marijuana. Their reactivity was compared to that of nonsmokers and asthmatics. Spirometry results were normal in the marijuana users. There was no significant difference in bronchial reactivity between marijuana smokers and nonsmoking controls, whereas the asthmatics demonstrated the expected hyperreactivity. These observations suggest that customary social use of marijuana may not produce abnormalities in airway function detectable by spirometry or bronchoprovocation.

Administration, Intranasal↗
PubMed1981

Regional neurohypophyseal blood flow and its control in adult sheep.

Regional neurohypophyseal and cerebral blood flows were measured by the radiolabeled microsphere technique in 30 adult sheep under light barbiturate anesthesia. Regional blood flows were determined under basal conditions. The responses of regional blood flow to alterations in arterial PCO2 and to changes in arterial blood pressure wee also determined. In addition, the relationship between regional neurohypophyseal blood flow and neurosecretory activity as judged by plasma arginine vasopressin levels was assessed. Under basal conditions median eminence blood flow averaged 461 ml.100 g-1.min-1 and did not significantly differ from neural lobe blood flow (436 ml.100 g-1.min-1). Blood flow in the neurohypophysis was about 8 times cortical and 16 times white matter blood flow in these animals. Median eminence and neural lobe blood flow proportionately increased far less than regional cortical or white matter blood flow under conditions of hypercarbia. With alteration of arterial blood pressure, regional neurohypophyseal blood flow remained constant beyond the limits of cerebral autoregulation. The neurohypophysis demonstrates a degree of blood flow homeostasis that exceeds that of any other brain area studied. Although the neurohypophysis is a diverticulum of the brain, its vascular system forms a unique functional as well as a unique anatomic unit.

Animals↗
PubMed1981

Rapid, shallow ventilatory pattern during exercise after histamine, bronchopprovocation.

The ventilatory response to inhaled histamine sufficient to double specific airway resistance was studied at rest and with exercise in normal subjects. There were no ventilatory alterations at rest but during steady-state exercise the subjects adopted a rapid, shallow breathing pattern. Despite this change and increased resistance over-all ventilation and oxygen consumption were unchanged.

Adult↗
PubMedDate not supplied

The induction of congenital spinal deformities in mice by maternal carbon monoxide exposure.

Carbon monoxide (CO) has been shown to be teratogenic in mice. High altitude hypoxia has also been shown to induce congenital vertebral anomalies in mice. The purpose of this study was to investigate the effect of maternal hypoxia owing to CO exposure and the production of congenital spinal deformities in the offspring. Sixty DBA-1J mice were bred using polygamous timed breeding methods. Pregnant females were exposed to 200, 400, or 600 ppm CO using a custom-designed gas blender system. Seven-hour exposures were performed on day 8.5, 9.5, or 10.5 of the 21-day gestation cycle. The neonates were euthanized at birth; the specimens were fixed, eviscerated, and radiographed. Congenital spinal deformities were observed (wedge, hemi, fused, and missing vertebrae; fused ribs) and were located in all regions of the spine. There was a statistically significant difference in the number of spinal deformities between all groups, with no defects in the controls and a 77% incidence at 600 ppm (p < 0.0001). There was no apparent correlation between the time of exposure and defect location. The most sensitive time of gestation was 9.5 days. We identified an animal model of congenital spinal deformities that compares favorably with the evidence of human congenital spinal deformities in cases of maternal exposure to CO and other gas and chemical fumes.

Animals↗
PubMedDate not supplied

Programme of education for obese patients. Preliminary results after one year.

We have evaluated the effects of a Programme of education for Obese Patients with a duration of 12 hours on weight loss and the modification of other indices for cardiovascular risk in 88 obese patients, during the first year of therapy. The BMI dropped from 33.1 +/- 0.2 Kg/m2 to 31.7 +/- 0.7 (p less than 0.01) and 30.9 +/- 0.7) (p less than 0.01) at 5 and 10 weeks respectively, stabilizing subsequently at 35 and at 55 weeks. This was accompanied by a decrease of the triglycerides levels (141 +/- 9 vs 111 +/- 6 mg/dl; p less than 0.01) and of the total cholesterol/HDL-cholesterol ratio (4.7 +/- 0.3 vs 4.2 +/- 0.12; p less than 0.05), as well as of the values for systolic blood pressure (143 +/- 3 vs 121 +/- 3 mm Hg; p less than 0.05) and diastolic blood pressure 81 +/- 2 vs 64 +/- 1 mm Hg; p less than 0.01) at the end of the study. In terms of OGTT, initially 23 patients were classified as diabetic (BMI 32 +/- 0.9 Kg/m2), 25 presented intolerance to carbohydrates (BMI 34.1 +/- 1.6 Kg/m2) and 40 were normal (BMI 33.2 +/- 1.2 Kg/m2). The weight loss in the first 5 weeks was less in patients with diabetes then in those with carbohydrate intolerance and in the normal patients (2.2 vs 3.7 vs 5.9 Kg; p less than 0.01). From the 10th week on no differences were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗