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Biomedical subjects

E Matute

Publications and source records attributed to E Matute.

12 recordsLinked to original sources
PubMed2005

Clinical actions of subarachnoid sevoflurane administration in vivo: a study in dogs.

BACKGROUND: Halogenated ethers produce clinical effects at spinal sites. Nevertheless, in vitro and in vivo studies have not determined whether the immobilizing effect in the spinal cord is due to inhibition of nociceptive or motor transmission or both. Our goal was to characterize the clinical effects of direct spinal sevoflurane administration. METHODS: Five adult beagle dogs completed the study. In a randomized and blinded manner each animal received placebo (saline 0.1 ml kg(-1)) and three concentrations of pure sevoflurane administered intrathecally (0.05, 0.075 and 0.1 ml kg(-1)) by means of a permanent spinal catheter. Sensory and motor block and state of consciousness were determined at baseline and at predetermined regular intervals until at least 2 h after total recovery. RESULTS: None of the dogs presented a decrease in consciousness with either 0.05 or 0.075 ml kg(-1) of sevoflurane. Administration of 0.1 ml kg(-1) produced light sedation (2 on a four-point sedation scale) in three of the five dogs. A comparison of the duration of the sensory and motor blocks among the three sevoflurane dosages shows a significant dose-dependent increase that is greater in all cases than that for the saline solution. CONCLUSIONS: Spinal administration of pure sevoflurane resulted in a dose-related and totally reversible motor and sensory regional block without any signs of clinical neurotoxicity or significant decrease in consciousness. Therefore the model allows us to comment on the analgesic effects at the spinal level in addition to the direct immobilizing effects of sevoflurane.

Anesthesia, Spinal↗
PubMed2004

Effects of propofol and sevoflurane on the excitability of rat spinal motoneurones and nociceptive reflexes in vitro.

BACKGROUND: Spinal actions of halogenated ethers are widely recognized, whereas spinal actions of intravenous anaesthetics like propofol are less clear. The aim of this study was to compare the spinal effects of propofol and sevoflurane. METHODS: We used an isolated spinal cord in vitro preparation from rat pups and superfused the anaesthetics at known concentrations. Responses of motoneurones to single and repetitive C-fibre intensity stimulation (trains of 20 stimuli at 1 Hz) of a lumbar dorsal root were recorded from the corresponding ventral root via a suction electrode. RESULTS: Stimulation trains produced a wind-up of action potentials in motoneurones. Both propofol and sevoflurane produced a significant concentration-dependent depression of the evoked wind-up, although at clinically relevant concentrations sevoflurane exhibited a larger intrinsic efficacy. Applied at anaesthetic concentrations, sevoflurane 250 micro M abolished action potentials whereas propofol 1 micro M only produced a reduction close to 50%. At these concentrations, sevoflurane produced a large depressant effect on the monosynaptic reflex whereas propofol was ineffective. CONCLUSIONS: Sevoflurane produces large inhibitory effects on nociceptive and non-nociceptive reflexes which are likely to contribute to immobility during surgery. Compared with sevoflurane, propofol appears to have much weaker effects on spinal reflexes such as those recorded in an isolated preparation.

Anesthetics, Inhalation↗
PubMed2003

Characterisation of sevoflurane effects on spinal somato-motor nociceptive and non-nociceptive transmission in neonatal rat spinal cord: an electrophysiological study in vitro.

Sevoflurane is the latest halogenated ether introduced in clinical anaesthesia, and its effects at the spinal level are not fully characterised. The rat hemisected spinal cord preparation was used to test the effects of sevoflurane on spinal nociceptive and non-nociceptive synaptic transmission as well as on excitations produced by application of glutamate-receptor agonists. Sevoflurane was dissolved in artificial cerebrospinal fluid (ACSF) with a specific vaporiser, and its final concentration was assessed with gas chromatography. Sevoflurane reduced the mono-synaptic reflex (EC(50) approximately 219 microM) and the slow components of the dorsal root-ventral root potentials (EC(50) approximately 72 microM) elicited by single dorsal root stimulation as well as the cumulative depolarisation (CD) elicited by repetitive stimulation (EC(50) approximately 98 microM). AMPA- and NMDA-induced depolarisations were also reduced by sevoflurane (respective EC(50)s were 206 and 127 microM). Inhibition of NMDA-induced depolarisation was TTX resistant. However, complete blockade of NMDA receptors with d-AP5 did not prevent further reduction of the CD by sevoflurane. All the effects reported were concentration-dependent and reversible. We conclude that sevoflurane applied at clinically relevant concentrations induces a strong depression of nociceptive and non-nociceptive spinal systems, which may be partly mediated by interfering with excitatory amino acid transmission.

Anesthetics, Inhalation↗
PubMed2000

Does literacy have an effect on stick construction tasks?

Since constructional apraxia is often concomitant with brain lesions, the study of constructional tasks in the non-brain-damaged population might be useful in helping to disentangle other causal factors. This paper explores the performance of illiterate individuals (N = 29) as compared to that of semiliterates (N = 21) and literates (N = 23) in order to see the effect of reading and writing abilities on constructional tasks. Each participant was asked to construct 4 figures based upon models having varying degrees of complexity. A global criterion of lack of fidelity and several analytic criteria (related to distortion, rotation, and disarticulation errors) were used to evaluate performance. Although illiterates generally made more errors than semiliterates and semiliterates more than literates, only some of these differences were statistically significant. Significant differences were found for lack of global fidelity and disarticulation errors when all 4 figures were considered together. Subtler data emerged with respect to single figures.

Adolescent↗
PubMed2000

Coherence in short narratives written by Spanish-speaking children with reading disabilities.

A novel analysis of coherence using a combination of three criteria (syntactic connexity, pragmatic complexity, and rhetorical well-roundedness) was applied to short narratives produced by a group of 60 Spanish-speaking children of different ages and grades with reading disabilities and compared to those produced by normal children. We posit a scale of 6 degrees of increasing coherence. This feature of children's writing, together with 2 others (viz. number of propositions, or "story points," recovered and number of words employed), was compared to features of children's reading by means of discriminant analysis in relation to age. We show that the combination of age, words read per minute, and degree of coherence achieved an optimal discrimination of the 2 groups.

Adolescent↗
PubMed1997

[Efficacy of ondansetron in the prevention of nausea and vomiting after laparoscopic cholecystectomy].

To assess the efficacy of 4 mg of intravenous ondansetron versus placebo for the prevention of postoperative nausea and vomiting (PONV) in cholecystectomy, a type of surgery that is highly emetic. A random, double blind, placebo controlled study of 40 women over 18 years of age who were scheduled for non urgent laparoscopic cholecystectomy under general anesthesia. The patients were assigned to two groups to receive ondansetron (n = 23) or placebo (n = 17). Premedication and anesthesia were similar for all. The severity of PONV in the first 24 hours after surgery was recorded. There were no significant differences between the two groups with respect to biological characteristics or other factors that might influence the presentation or severity of PONV. The percentage of PONV-free patients was significantly higher in the ondansetron group than in the control group (73.91 and 11.76%, respectively; p < 0.001). Intravenous administration of 4 mg ondansetron is significantly superior to placebo for PONV prophylaxis after laparoscopic cholecystectomy.

Adult↗
PubMed1996

Floating-Harbor syndrome. A neuropsychological approach.

We describe a six year old Mexican girl whose clinical picture (short stature with delayed bone age, language difficulties and triangular face with prominent nose) was compatible with the diagnosis of Floating-Harbor Syndrome (FHS). A neuropsychological evaluation disclosed a mild mental retardation, a constructive apraxia, a comprehensive and expressive language impairment. The analysis of the present case and sixteen patients previously described establishes that the FHS is mainly characterized by proportionate short stature with significantly delayed bone age, delayed expressive language and peculiar face.

Age Determination by Skeleton↗
PubMed1995

[Prevalence of viral hepatitis in candidates for orthopedic surgery].

OBJECTIVES: To study the prevalence of positive serology results for hepatitis B and C viruses among patients scheduled for elective orthopedic surgery, to establish risk groups and to assess the economic cost involved in testing patients in such groups. PATIENTS AND METHODS: We performed a retrospective study of 1090 preoperative charts for patients awaiting elective orthopedic surgery between November 1993 and January 1995. Variables recorded were age, sex, physical status, history of alcoholism or addiction to injected drugs, associated disease (liver disease, chronic kidney failure and hemodialysis, and coagulation disorders), history of blood products transfusion, preoperative liver enzymes and blood levels of AcVHC and AgVHB as determined by enzyme immunoassay. RESULTS: Mean age was 51.8 (SD 17.5). Women predominated, accounting for 60.6% of the sample. ASA I and ASA II patients accounted for 84.9%, 72 (6.61%) had had previous transfusions, 51 (4.6%) suffered liver disease, 4 (0.36%) had coagulation disorder, 5 (0.45%) were receiving hemodialysis for chronic kidney failure, and 5 (0.45%) admitted having injected drugs. We discovered alterations in preoperative liver enzyme levels in 116 (10.6%) cases. Sixty-five (5.96%) were positive for AcVHC and 13 (1.19%) were positive for AgVHB. Factors that predicted positive results for hepatitis C and B were liver disease, previous administration of blood products, chronic kidney failure requiring hemodialysis, drug addiction and high preoperative liver enzyme levels. Serologic testing for viruses performed on patients in this risk group would have detected 76.6% of the positive cases, resulting in savings of 90% of the cost of indiscriminate testing. CONCLUSIONS: We believe that patients with histories of liver disease, blood product transfusion, chronic kidney failure with hemodialysis or drug addiction, or with high liver enzyme levels should be tested for hepatitis B and C before surgery.

Adult↗
PubMedDate not supplied

[Neuropsychological predictors of reading ability in Spanish].

INTRODUCTION: Learning how to read has been associated with different types of linguistic and non-linguistic skills. However, few studies have looked at the association between neuropsychological test performance and reading skills at different ages during childhood. AIM: To analyze the association between neuropsychological test scores and reading performance, and to investigate the influence of age, gender and type of school (public or private) over reading test performance. SUBJECTS AND METHODS: The sample included 625 6 -to-15 year old children (207 Colombians, 418 Mexicans; 277 boys, 348 girls). The following cognitive abilities were assessed: reading speed and reading comprehension and attention, memory (coding and recall), perception, visuospatial and conceptual abilities and executive functions. RESULTS: The best neuropsychological test predictor for reading speed was Letter Cancellation, and for reading comprehension was Memory for a Story. Children from private schools performed better in most reading tests than children from public schools. Differences between boys and girls were observed in only two reading tests. CONCLUSION: Reading speed correlates mainly with attentional skills and reading comprehension with verbal memory. Reading abilities in school age children are influenced mainly by age and type of school and little by gender.

Achievement↗
PubMedDate not supplied

[Genetically caused deafness: prospective study of 109 children in a special school].

109 deaf children were studied prospectively, in a special school, with an interdisciplinary focus. Clinical and audiologic studies were performed on several members of the family, in the first degree, of outstanding cases. 48 cases (44%) were identified as being of genetic etiology, 20 were acquired cases of deafness and 41 cases lacked sufficient data to reach an etiologic diagnosis.

Abnormalities, Multiple↗