Boletin de estudios medicos y biologicos最新文献

{"title":"Visual evoked potentials in a sample of schizophrenic patients.","authors":"C M Contreras,&nbsp;R Garnica,&nbsp;A Torres-Ruiz,&nbsp;C Arenas,&nbsp;M L Marván,&nbsp;H Lara,&nbsp;M Vázquez","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Variations in evoked potentials utilizing a photic stimulus in a sample of psychiatric patients compared to a healthy sample were evaluated. A group of patients diagnosed as schizophrenic was tested against a sample of healthy volunteers in a trial combining visual evoked potentials and a simultaneous cognitive processing. The stimulus was a checkerboard pattern presented under three different conditions. The results indicate diminished P100 and lack the reactivity associated with cognitive processes in schizophrenic group. The P200 component also lacked, in the inpatient group the changes associated with the performance of the trial. Finally the multiple P300 component was shortened in latency and decreased in amplitude in the schizophrenia group. Besides, P300 interhemispheric shifts related to trials, were commonly inverted in schizophrenics. Results are interpreted as a lacked interhemispheric coordination in schizophrenics, rather than a fixed hemispheric alteration. Likewise, an attenuation in processing from specific cortical areas to association cortex is concluded.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"38 1-2","pages":"22-8"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13442785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An automated system for detection and analysis of locomotor behavior in crustaceans.","authors":"F Fernández de Miguel,&nbsp;J Cohen,&nbsp;L Zamora,&nbsp;H Aréchiga","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>An efficient and simple system is presented for the analysis of crustacean locomotor behavior. The system is composed by six dual-compartment actographic chambers with photocoupling circuits for movement detection, and a device for acquisition and analysis of data. Such device is made by a digital interface which feeds into a microcomputer with disc unit and printer. Information is processed in real time during the experiment, with a simultaneous printout and storage in a floppy disc.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"37 3-4","pages":"71-6"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13776830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"6-Thioguanine resistant T-lymphocyte determination as a possible indicator of human ionizing radiation exposure.","authors":"P Ostrosky-Wegman,&nbsp;R Montero,&nbsp;C Cortinas de Nava,&nbsp;F Hurtado","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>We used the autoradiographic assay to assess human in vivo somatic cell gene mutation at the hypoxanthine guanine phosphoribosyl transferase (hgprt) locus in T-lymphocytes. Cells able to incorporate tritiated thymidine in vitro in 6-thioguanine containing short-term cultures were enumerated in order to determine 6-thioguanine resistant (TGr) variant frequencies in cryopreserved lymphocytes from control individuals and 3 persons suspected of 60Co exposure from an accident in Cd. Juárez, México. The data indicate that the lymphocyte TGr variant frequency assay may be potentially usefull for human population monitoring following accidental exposures to ionizing radiation.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"37 3-4","pages":"77-81"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13775034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unusual peaks of oxygen consumption under special alimentary conditions.","authors":"R Racotta,&nbsp;P Even","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Oxygen consumption (VO2), carbon dioxide production (VCO2), the resulting respiratory quotient (RQ), and motor activity were recorded simultaneously by an on-line computer every ten seconds during 16-20 hours in two decerebrate male rats. Being aphagic and adipsic the rats were fed twice daily by gastric intubation with a mixture of powdered milk plus sugar or plus sunflower oil (approx. 300 KJ daily) in 10-20 ml tap water. In all seven tests performed on these rats the recordings presented very steep reductions of RQ due every time to steep increases in VO2 without increases in VCO2. Mean number of VO2 peaks in all experiments was 12.4 +/- 1.8 (SE) with mean duration of 21.3 +/- 2.8 min. Two normal male rats were fed the same diet and on the same schedule: they presented similar VO2 peaks in 8 out of 12 experiments. Mean number was 8.7 +/- 1.0 with mean duration of 13.6 +/- 2.2 min. The VO2 peak periods never occurred in rats fed ad libitum. In the two normal rats oil ingestion produced more effect than sugar. It is suggested that the phenomenon could be due to a metabolic imbalance possibly of hepatic origin, more evident in decerebrate rats. VO2 peaks could be produced by enhanced ketogenesis, gluconeogenesis and/or extra-mitochondrial (peroxisomal, microsomal) oxidation.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"37 3-4","pages":"83-6"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13663406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Repetitive electrical stimulation of X-area and parabrachial lateral nucleus: effects upon ponto-geniculo-occipital activity in the reserpinized cat.","authors":"R Alvarado,&nbsp;M García,&nbsp;J Manjarrez","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The ponto-geniculo-occipital (PGO) activity is a characteristic field potential of paradoxical sleep, that can be continually induced by reserpine administration. It has been postulated that the X area (XA) and parabrachial lateral nucleus (Pbl) contain the generator cells for the PGO activity. In this study, repetitive electrical stimulation in the XA and Pbl was applied, with the aim of inducing progressive plastic changes in PGO activity, which was recorded from the lateral geniculate nucleus (LGN). Reserpinized cats were used; they were curarized and maintained with artificial respiration. We analyzed the PGO spike frequency at one, five and sixty minutes after stimulation, which was given every 30 minutes for at least 8 consecutive hours. Stimulation of the XA did not produce changes, while that of the Pbl induced a relatively poor progressive increment in the PGO spike frequency. The findings obtained with XA stimulation discard the possibility of inducing functional plastic changes in this region. On the other hand, the response to Pbl stimulation indicates an activation of the PGO spike generator system. These differences suggest that these nuclei have different influence on PGO activity, although it is possible that the responses found in the Pbl were indirect effects, given its anatomical relationships.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"37 3-4","pages":"87-93"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13775036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of nickel chloride on iron-deficiency in rats.","authors":"E L Novell,&nbsp;N L Rodrigues,&nbsp;G S Bianchi,&nbsp;B O Ribas","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The present study was designed to investigate the effects of nickel chloride on dietary iron deficiency in rats. The degree of iron deficiency was relatively moderate, but a more generalized anemia occurred in iron deficiency, in absence of nickel chloride. Moderate iron deficiency anemia induced increased lactate-dehydrogenase activity of serum and bone marrow, perhaps related to the decreased production of energy by oxidative means. Nickel chloride, perhaps for its ability to change iron absorption, for the maintenance of bone marrow metabolism and for to increase ceruloplasmin activity, inhibited the alteration on hemoglobin synthesis. Furthermore, nickel chloride possibly for its action on copper content and Cu-Zn superoxide-dismutase activity, inhibits the shortening of the red cell life span, caused by superoxide radicals.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"37 3-4","pages":"95-9"},"PeriodicalIF":0.0,"publicationDate":"1989-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13775038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brain injury following cardiorespiratory arrest in cats. Effects of alphaxalone-alphadolone.","authors":"M Cervantes,&nbsp;R Ruelas,&nbsp;R Sánchez,&nbsp;G Alvarez-Reséndiz","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The effects of alphaxalone-alphadolone acetate (27.07 microM/kg-7.68 microM/kg) on neurologic injury following acute cerebral ischemia induced by an 8 min cardiorespiratory arrest (CRA) were investigated in cats through the analysis of neurological deficit scores and brain electrical activity; i.e., electroencephalogram (EEG) from parieto-occipital cortices and EEG and multiunit activity (MUA) from mesencephalic reticular formation (MRF). The CRA resulted from electrically induced cardiac arrest and stopping of mechanical ventilation in paralyzed cats which were successfully resuscitated within the immediate 4 min after the end of CRA. Two groups of cats were studied: I. Untreated, which received saline iv; II. Treated, which received alphaxalone-alphadolone acetate iv, 7-9 min after the end of CRA. Neuromuscular blockade and mechanical ventilation were maintained until 8 h following the CRA; then the cats were allowed to recover spontaneous respiratory activity. EEG phenomena were different in untreated and treated cats during this immediate post-arrest period. The former showed rhythmic bursts of fast (12-20 Hz) EEG activity at 1-2 sec intervals from 15-20 min until 3-4 h after the CRA, abundant spikes and delta-like waves. By contrast, administration of alphaxalone-alphadolone acetate resulted in burst suppression EEG pattern during 1 h. Progressive recovery of background EEG activity occurred afterwards. MUA from MRF disappeared during the CRA, however 6 h later the mean MUA frequency in untreated cats ranged between 32-46% and in treated cats 18-27% of their control mean frequencies during paradoxical sleep (100%). Daily electrographic records were performed in all the cats during quiet attentive behavior at each of the five days following the CRA. Significant differences were found in the frequency distributions of MUA from MRF (1st day, p less than 0.01; 5th day, p less than 0.01) as well as in the cortical EEG waves (1st day, p less than 0.01; 5th day, p less than 0.05) before and after the CRA in the untreated group. A wide dispersion of MUA values, and increased proportions of delta and theta-like waves and spindle bursts, besides a significantly high (p less than 0.001) number of spikes occurred in these EEG records the days following the CRA. The frequency distributions of MUA and EEG did not significantly differ before and after the CRA in the treated group; however, a significantly high (p less than 0.05) number of spikes was found in treated cats following the CRA.(ABSTRACT TRUNCATED AT 400 WORDS)</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"37 1-2","pages":"17-27"},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13942470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in social dynamics associated to the menstrual cycle in the vervet monkey (Cercopithecus aethiops).","authors":"E García-Castells,&nbsp;J Juárez González,&nbsp;F R Ervin,&nbsp;C Guzmán-Flores","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Behavioral changes associated to the menstrual cycle in a social group of vervet monkeys (Cercopithecus aethiops) were studied. Three adult females were used as experimental subjects and in these, vaginal smears were taken every other day in order to detect their menstrual cycles. Only the dominant and the mid-ranking female showed regular cycles while the low-ranking female showed amenorrhea. The menstrual cycles were divided into five periods (menstrual, premenstrual, luteal, ovulatory and follicular) which were related to the behavioral data. Social behavior recordings were taken during one hour daily for five consecutive months; the data were adjusted twice in order to follow the cycles of the females with regular menstruations. By plotting in a matrix the relative frequencies of joins and displacements, the social position of each animal as well as the group's social organization and dynamics were evaluated. A clear tendency towards social rejection (emitting less joins and increasing the amount of displacements) was detected during the premenstrual periods of the dominant female which abruptly changed towards affiliation during menstruation. This observation was detected in all group members no matter their age-sex class or social position during the five months of observation. When the data were analyzed following the mid-ranking female's cycle, no consistent changes were apparent. The importance of social stimuli in the modulation and expression of hormone-related behavior is stressed, as well as the need of using social settings in the experimental analyses of premenstrual mood and behavior disorders.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"37 1-2","pages":"11-6"},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13941308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Posttetanic potentiation in decentralized and nondecentralized superior cervical ganglia of the cat.","authors":"M A Morales,&nbsp;F Alonso-deFlorida","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The present investigation was aimed to answer the following elementary, though important question concerning the sympathetic ganglion: Do the decentralized preganglionic terminals retain their full capacity to develop posttetanic potentiation (PTP) before substantial Wallerian degeneration takes place? Experiments were performed on the cat superior cervical ganglion in situ, and they followed a factorial design. The factors were: tetanization (supramaximal pulses, 0.2 ms, 24 Hz, 30 s), acute decentralization, and moderate hexamethonium blockade (5 mg/kg). Two levels were dealt with, namely, the indicated maneuvers were either performed or not performed. PTP was was measured in the S2 wave and the following variables were studied: decay constant, area under the curve and delay to summit occurrence. The analysis of variance showed that decentralization did not affect the development of PTP. Therefore, the nondegenerated terminals are fully capable of sustaining PTP, without the aid of the preganglionic cell bodies.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"37 1-2","pages":"42-9"},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13696329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relations between anxiety, psychophysiological variables and menstrual cycle in healthy women.","authors":"C M Contreras,&nbsp;M L Marván,&nbsp;V Alcalá-Herrera,&nbsp;A Yeyha","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The present study was designed to explore whether changes occur in psychophysiological variables in healthy women not suffering from premenstrual tension. Variations in electroencephalogram frequencies, reaction time, somatosensory evoked potentials, and nerve conduction velocity were examined in a sample of 30 women, in relation to scores from the Hamilton Psychiatric Rating Scale for Depression and the State-Trait Anxiety Inventory. Trials and recordings were done weekly. EEG frequencies decreased before menstruation in all subjects. However, there were no significant changes for reaction time, nerve conduction velocity, HAMILTON nor State-Trait Anxiety scales associated with subperiods of the menstrual cycle. To explore the impact of anxiety, high and low anxiety groups were formed. The high anxiety group showed the highest scores in the A-Trait form, longer reaction time, enlarged latencies of the P100, but shorter nerve conduction velocity. Anxiety scores as well as reaction time increased during the premenstrual period only for the low anxiety group. The authors conclude that for some women premenstrual anxiety may be related to previous and continuous high levels of anxiety, which associated with some subtle neurological differences as compared with women who rated in low scores for anxiety.</p>","PeriodicalId":75608,"journal":{"name":"Boletin de estudios medicos y biologicos","volume":"37 1-2","pages":"50-6"},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13942469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}