Biomedical subjects
Publications and source records attributed to J Prado.
The content of kappa, iota and lambda carrageenan in mixtures was determined by application of FT-IR spectroscopy combined with partial least-squares multivariate regression (PLS). This method allows the determination of the relative amounts of the different carrageenans in a rapid and accurate manner.
OBJECTIVES: Spectral power of 40 all-night sleep EEGs (Cz-Pz bipolar lead) recorded in 20 healthy young subjects was calculated after normalization on 30-s consecutive epochs by means of an autocorrelation method based on a 15-order autoregressive model. METHODS: The spectral parameters were calculated for the 7 main EEG bands: slow delta (0.7-2 Hz); fast delta (2-4 Hz); theta (4-8 Hz); alpha (8-12 Hz); sigma (12-16 Hz); beta1 (16-35 Hz); and beta 2 (>35 Hz). RESULTS: Strong negative correlations were found between power in the fast delta and either the alpha or the beta bands and between slow delta and theta bands, whereas the two delta bands showed little correlation with each other. CONCLUSION: The possibility that theses different relationships of slow and fast delta components with other frequency bands might reflect the neocortical or the thalamocortical origin of the delta waves is discussed.
Filter banks analysis is an easy and quick computing way to implement time-scale methods, these being well suited for short events as well as for large waveforms detection tasks. We propose a non-uniform oversampled filter banks to analyze sleep EEG single channel signal, the different subbands matching the classical EEG rhythms. In order to preserve the temporal shapes information, filter banks are oversampled. Coupling the informations conveyed by the different outputs allow to perform an automatic hypnogram.
The interrelationships between the immune system and the pineal hormone, melatonin, have been explored recently. The present studies investigated the effects of daily melatonin injections on reproductive and spleen function in male Syrian hamsters. Testes weights and serum testosterone levels were depressed after 8-10 weeks of daily melatonin injections. Melatonin-treated hamsters exhibited increased splenic lymphoproliferative responses to a polyclonal T-cell mitogen (concanavalin A (Con-A)), but decreased proliferation following stimulation with a polyclonal B-cell mitogen (lipopolysaccharide). It appears that daily melatonin injections in male hamsters increase the T-cell-mediated immune capacity while reducing the antibody-mediated immune potential. These data suggest that chronic, daily melatonin alters immune system responsiveness in hamsters by shifting the balance of cellular and humoral reactivity.
Time-frequency or time-scale methods are well suited for short events as well as for large waveforms detection tasks. Filter banks analysis is an easy and quick computing way to implement these methods. We propose a non-uniform oversampled filter banks to analyze EEG single channel signal, the different subbands matching the classical EEG rhythms. We use oversampled filter banks to preserve the temporal shapes information. In order to illustrate this method, we show different spindle temporal structures as also their meaning in terms of sleep stage detection.
Choledochocele is an extremely rare congenital lesion of the biliary tree causing abdominal pain, pancreatitis, and obstructive cholestasis. Traditionally the therapy for this malformation has been surgery. Recently endoscopic therapy has been utilized alternatively for the treatment of choledochocele in adults. We report the case of a 2-year-old girl with a choledochocele who was treated by endoscopic sphincterotomy and placement of a biliary stent. The prosthesis was removed after 4 months. After a follow-up of 20 months the patient remains free of symptoms. Our experience suggests that endoscopic treatment of congenital biliary disease can be performed accurately. Further studies will be necessary to confirm the value of stent implantation in congenital bile duct stenosis.
Four non-consecutive nights of sleep were recorded in eight young volunteers complaining of chronic poor sleep. The subjects received a placebo or a 10 mg zolpidem dose prior to bedtime according to a Latin square double-blind design. All-night spectral analyses of the Cz-Pz lead were associated to the standard polysomnography. According to the visual scoring performed with the Rechtschaffen and Kales criteria, zolpidem significantly increased the stage 4 amount and reduced waking. Compared to placebo no difference in sleep stages was observed when the scoring was based on the power in the 0.7 to 4-Hz band. In zolpidem nights power was significantly reduced in the 4 to 8-Hz band during NREM (stages 2, 3 and 4) and was increased in the 2 to 4-Hz band during REM sleep. A significant reduction of fast activities over 12 Hz was observed during the first 3 h of sleep. Concerning slow wave activity, the only change noted was a significant slowing of its build-up rate at the beginning of cycle 1.
The results in pregnancies obtained in sixty six patients recanalized using the microsurgical principles in a period of five years are presented. The pregnancy rate was 72.7% with 31 new borns (47%), 15 abortions (22.7%) and 2 ectopic pregnancies (3%). Using the life table the accumulative probability of pregnancies was 39%, 55%, 87% at 6, 12 and 24 months respectively. The results are statistically correlated with the parameters of age, time of sterilizations, technique of anastomosis and only or two Fallopian tubes reanastomosed.
Patients admitted to intensive care units (ICU) experience constant changes in their general condition. Therefore, the determination of Apache score within the first 24 hours of admission may not be a reliable index of severity. The aim of this study was to measure daily Apache scores in ICU patients, and to determine if the maximum score (Maximum Apache) attained during hospitalization had a better prognostic value than that of admission. We measured daily Apache scores to 314 patients admitted to Hospital Clínico UC ICU. Mean admission score was 17.5 +/- 9.3 (range: 1-47) and mean maximum score was 18.6 +/- 9.7 (range: 1-47), p < 0.001. Mortality during ICU stay was 17.2%, and 8.6% during hospitalization after ICU discharge. Only 78.3% of patients attained their maximum apache score during the first 24 hours of admission, whereas 21.7% attained it during the rest of ICU hospitalization. Excluding subjects with less than one day of ICU stay, 33% of patients attained maximum Apache score after 24 hours of ICU admission. Statistical analysis showed that maximum Apache score was a better predictor of mortality than that of admission.
A retrospective study on the effects of dobutamine on hemodynamic parameters of tissue oxygenation and lactic acid levels was performed in 35 patients. The use of the drug in a mean dose of 5.0 +/- 2.1 ug/kg/min was associated with a significant increase in cardiac index, oxygen transport and consumption and decrease in arterial lactic acid levels. A separate analysis of patients with or without basal hyperlactacidemia and those with favorable (decrease) or unfavorable (no change or increase) lactic acid response to the drug, was performed. This analysis disclosed important disagreements between changes in hemodynamic parameters of oxygen consumption and transport and arterial lactic acid levels, as indexes of tissue perfusion. It is concluded that is advisable to monitor together hemodynamics, oxygen transport and consumption and arterial lactic acid in patients with severe cardiorespiratory disturbances or shock.
Oocyte donation programs offer an alternative treatment for infertile women with ovarian failure or abnormal ovarian function. Seventeen cycles of in vitro fertilization and embryo transfer with donated oocytes were performed in 13 women, with a mean age of 34.8 years. The hormonal replacement therapy consisted of a fixed dose of oral estradiol valerate, 6 mg daily, and intramuscular progesterone in oil, 100 mg daily. Estrogen and progesterone were continued for 10 more weeks after embryo transfer if pregnancy was established. After 13 embryo transfers, 8 pregnancies were obtained, for a pregnancy rate per transfer of 61.5%. Today seven pregnancies are progressing normally, including one set of twins. This results suggest that an oocyte donation program using a fixed and simple hormonal replacement therapy is an adequate treatment for these infertile couples.
Two groups of patients with cystic fibrosis were compared. The screened group, detected with an improved neonatal screening assay for immunoreactive trypsin, developed fewer chest infections requiring treatment and gained more weight than the unscreened group. Early diagnosis by screening seems to affect early morbidity.
In this work the morphological types of the nervous receptors in the pulmonary vessels of the Wistar rat are studied with the Koelle-Friedenwall, Champy-Maillet and Jabonero techniques. Different types of corpuscules are described. Some are simple and some are more complex (tree-like terminals of Seto type). The localization of these corpuscules is variable. Sometimes they are located in the pulmonary vessels and sometimes in the conjunctive tissue. These receptors are interpreted as baro-receptors i.e. receptors of change of pressure.
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