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Biomedical subjects

R Castillo

Publications and source records attributed to R Castillo.

At least 145 records · Page 8Linked to original sources
PubMed1986

Sequential nonstress testing with use of each fetus as its own control.

The sequential nonstress tests of 126 high-risk fetuses were assessed for baseline fetal heart rate, acceleration frequency, amplitude, and duration and the observance of fetal heart rate decelerations. In 108 fetuses (563 tests) with normal perinatal outcomes, no significant trends in these parameters were found. In 18 fetuses (104 tests) with perinatal compromise, 16 had significantly declining acceleration frequencies, 15 had decreasing acceleration duration, four had rising mean baseline rates, and seven, in their last test before delivery, had repetitive late or severe variable decelerations. The last tests of 11 of these 18 fetuses met institutional criteria for reactivity. When the nonstress tests of compromised fetuses were viewed sequentially, acceleration frequency declined by an average of 59% and acceleration duration by an average of 40%. Sequential assessment of the nonstress test, when compared with the use of standard reactivity criteria, improved test sensitivity from 39% to 89% and negative predictive value from 91% to 98%. We conclude that sequential nonstress test assessment in individual fetuses may improve the diagnostic value of this modality and lead to earlier recognition of fetal compromise.

Female↗
PubMed1986

Development of a computer program to analyze the parameters of platelet-vessel wall interaction.

The use of the Baumgartner perfusion system allows the morphometric quantification of platelets interacting with vessel wall, however it presents the basic difficulties of morphometrical measurements. In order to facilitate the procedure of evaluation we developed a semiautomated method to avoid the complexity of the classical evaluation. Our system consists on an optical picture analysis system connected with a specially developed computer program which allows fast quantification. Simultaneously to the outlining of interacting platelets the computer program recognizes, corrects, selects and stores the information, in order to perform the final calculations as previously established. This system has been demonstrated to be as effective as the classical morphometric evaluation in the measure of platelets interacting with subendothelium. Potential sources of error such as subjectivity of the observers in selecting the class of interacting platelets are avoided. The use of this combined method opens the possibility to adapt the Baumgartner perfusion system to clinical routine and to the screening of drugs that modify platelet adherence.

Animals↗
PubMed1986

Selective kappa opioid agonist for spinal analgesia without the risk of respiratory depression.

The effects of the selective kappa agonist, U-50,488H, on the motor response to noxious mechanical stimulation when administered intrathecally, as well as on respiratory rate and PaCO2 when administered by intracerebroventricular injection, were compared with those of morphine in experiments on rats. The agonist U-50,488H caused a dose-dependent increase in the threshold to noxious stimulation but did not have a potential for depression of resting ventilation. The results suggest that selective kappa opioid agonists may be suitable for clinical spinal (epidural) analgesia without the associated risk of respiratory depression.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1986

Defective platelet adhesion on vessel subendothelium in uremic patients.

Bleeding time, platelet retention on glass beads, and ristocetin-induced platelet agglutination (RIPA) in platelet-rich plasma were simultaneously determined for 20 patients with chronic renal failure and previous hemorrhagic history. In seven patients chosen at random out of a group of 16 in whom the three tests were abnormal, RIPA of uremic-isolated platelets in presence of normal platelet-poor plasma (PPP) and of normal platelets in presence of patient PPP were performed. In all cases, the first assay showed diminished agglutination, suggesting a platelet defect; however, uremic PPP did not inhibit the agglutination of normal platelets. In the same patients, the interaction of platelets with subendothelium was evaluated using Baumgartner's perfusion method. The subendothelial surface covered by platelets was significantly decreased in experiments with uremic whole blood when compared to normal controls. The interaction of platelets with subendothelium was also decreased when perfusions were carried out with platelet-plasma mixtures containing either normal washed platelets and uremic PPP or uremic washed platelets and normal PPP. These results show an impaired platelet adhesion caused both by a platelet and a plasmatic abnormality. Since uremic PPP decreased the adhesion of normal platelets to subendothelium but did not inhibit RIPA, it seems probable that the plasmatic defect could result in a defective binding between vWF and subendothelium. The influence of the red cell count on the platelet adhesion to subendothelium was reconfirmed by comparing perfusions of reconstituted blood with hematocrit values of 20% to 23% and 40% to 45%. In summary, a defective platelet adhesion to subendothelium has been postulated in uremic patients, caused by platelet and plasmatic alterations that are influenced by a low hematocrit.

Adult↗
PubMed1986

Percent acceleration time: a new method of fetal assessment.

The percent acceleration time (PAT) is a fetal heart rate parameter, which may be derived from the nonstress test (NST). It is based on measurement of the duration of individual movement-associated fetal heart rate accelerations (MAFAs), obtained during a nonstress test, and is calculated by the formula: (formula, see text) The authors studied 148 fetuses undergoing four or more serial nonstress tests who were delivered within one week of their last test. Percent acceleration time of fetuses with normal outcomes had a mean value of 15.5 +/- 10.0 (SD)%, correlated well with the frequency and amplitude of movement-associated fetal heart rate accelerations but was independent of gestational age and mean baseline fetal heart rate. No normal fetus had a percent acceleration time of less than 5% on its last nonstress test, while only one abnormal fetus had a percent acceleration time that exceeded the mean percent acceleration time of the normal group. All abnormal fetuses had a significant progressive decline in percent acceleration time (mean: 50.6%). Percent acceleration time values were more sensitive in identifying fetuses with perinatal compromise than were conventional criteria for nonstress test reactivity, and may provide a useful alternative to assessment of fetal status when other quantitative methods are unavailable (continuous ultrasound visualization) or less reliable (maternal perception, tokodynamometry, palpation).

Female↗
PubMed1985

Growth retardation in sickle-cell disease treated by nutritional support.

The effect of increased nutritional intake was evaluated in 5 growth-retarded children with sickle-cell disease. Growth on recommended daily calorie and protein intakes had been inadequate in all 5. Fat absorption and intestinal mucosal morphology were normal in all 5. 2 children were given nutritional supplementation by nasogastric intubation, 1 received nightly oral formula supplements, and 2 were supplemented with zinc, iron, folate, and vitamin E only. Nutritional supplementation by the nasogastric route produced a rapid sustained increase in growth rate, associated with striking reductions in pain crises and infections which had previously necessitated many hospital admissions. Oral supplementation improved the clinical course but had no effect on growth rate. Mineral and vitamin supplements influenced neither the growth rate nor the clinical course. The observations indicate that nasogastric nutritional supplementation may accelerate growth and reduce the incidence and severity of complications in growth-retarded children with sickle-cell disease.

Adolescent↗
PubMed1985

Phospholipids of normal and experimentally injured spinal cord of the miniature pig.

Experimental spinal cord trauma was produced in 3-month-old SS-1 miniature pigs by dropping a 25 g weight from a height of 20 cm upon the exposed spinal cord. The histological lesion consisted of edema and hemorrhage. Phospholipid concentration and composition, cholesterol concentration and phospholipid fatty acid composition were determined in whole spinal cord 3 hours after injury, and in spinal cord myelin 5 hours after injury. Three hours after injury phospholipid and cholesterol concentration were decreased by about 14% in the whole spinal cord. Trauma had no effect on the phospholipid composition of whole spinal cord and myelin. Fatty acid composition of myelin also did not change after injury, and changed very slightly in the whole spinal cord. It is concluded that edema following spinal cord trauma is much more extensive than previously assumed. Furthermore, peroxidation of membrane lipid fatty acids does not appear to be a significant factor in spinal cord pathology 3 hours after injury.

Animals↗
PubMed1985

Chest physical therapy: comparative efficacy of preoperative and postoperative in the elderly.

Although chest physical therapy (PT) immediately after surgery lowers the risk of postoperative pulmonary complications, several reports indicate preoperative chest PT results in further improvement. This study compares the effects of initiating chest PT either before and/or after chest surgery in patients over age 65. We studied two groups: 130 patients (the PRE group) undergoing both pre- and postoperative therapy and 150 patients (the POST group) undergoing only postoperative therapy, dividing them into four surgical subgroups: lung, cardiac and other thoracic surgery, upper abdominal, and lower abdominal (considered low risk compared with the other three). Overall complication rates and atelectasis rates were significantly lower in the PRE high-risk subgroups. PRE and POST pneumonia rates, however, were statistically equivalent in all surgical subgroups. Since the low rate of pulmonary complications for PRE-group patients undergoing thoracic or upper abdominal procedures is comparable to that for PRE-group therapy in much younger populations, advanced age alone does not appear to be a significant risk factor. The lack of effect on incidence of pneumonia indicates that preoperative chest PT only counters the altered pulmonary mechanics responsible for atelectasis, but has no effect on pulmonary complications due to infection.

Abdomen↗
PubMed1985

Adverse effects secondary to the treatment with plasma exchange.

Side effects and their relationship with the material used were analyzed in 748 plasma exchanges (PE) performed in 75 patients. The total incidence of acute and mild adverse effects (chills and/or fever, paraesthesias, allergic reactions, acute anaemia, vasovagal reactions, abdominal pain and hypotension) was 18.04%. Two patients developed an episode of left cardiac insufficiency. One patient in whom all PE were performed with fresh frozen plasma (FFP) developed metabolic alkalosis. Three patients developed sepsis during treatment with repeated PE and immunosuppressive drugs; in these three patients a permanent vascular inlet was used (shunt or catheter). All patients in whom only FFP was used as replacement solution developed non-A, non-B hepatitis. Neither haemorrhagic nor thrombotic episodes were observed in these patients. It is of the greatest importance to choose the most suitable material for each patient and to develop a careful technique in order to avoid these complications during treatment with PE.

Abdomen↗