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Biomedical subjects

E Martin

Publications and source records attributed to E Martin.

At least 325 records · Page 18Linked to original sources
PubMed1996

Clonal and temporal patterns of nasopharyngeal penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae stains in children attending a day care center.

The nasopharyngeal carriage of penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae (PSSp and PRSp, respectively) was analyzed in 116 children attending a day care center in Rouen, France, by three observation periods in November, January, and March of the winter of 1993 to 1994. The carriage rate of S. pneumoniae was found to be 47.7, 47.3, and 49.6% at each different observation period, and PRSp accounted for 42.2, 40.3, and 40.6% of pneumococcal isolates, respectively. The 52 isolates recovered in November were distributed in 34 electrophoretic types (ETs) by multilocus enzyme electrophoresis; 15 PRSp isolates, all of serotype 23F, belonged to a clonal complex of five ETs, representing the dominant population of PRSp in November. The temporal pattern of S. pneumoniae carriage was studied in 17 children who were colonized at the three periods by multilocus enzyme analysis of their isolates. The PSSp isolated, exhibiting distinct ETs, were transient only among these day care attendees. In contrast, most of the PRSp isolated in January and March belonged to the clonal complex. Thus, this PRSp population was resident in the day care center throughout the study period.

Carrier State↗
PubMed1996

Diagnostic and prognostic value of cerebral 31P magnetic resonance spectroscopy in neonates with perinatal asphyxia.

The impact of depressed neonatal cerebral oxidative phosphorylation for diagnosing the severity of perinatal asphyxia was estimated by correlating the concentrations of phosphocreatine (PCr) and ATP as determined by magnetic resonance spectroscopy with the degree of hypoxic-ischemic encephalopathy (HIE) in 23 asphyxiated term neonates. Ten healthy age-matched neonates served as controls. In patients, the mean concentrations +/- SD of PCr and ATP were 0.99 +/- 0.46 mmol/L (1.6 +/- 0.2 mmol/L) and 0.99 +/- 0.35 mmol/L (1.7 +/- 0.2 mmol/L), respectively (normal values in parentheses). [PCr] and [ATP] correlated significantly with the severity of HIE (r = 0.85 and 0.9, respectively, p < 0.001), indicating that the neonatal encephalopathy is the clinical manifestation of a marred brain energy metabolism. Neurodevelopmental outcome was evaluated in 21 children at 3, 9, and 18 mo. Seven infants had multiple impairments, five were moderately handicapped, five had only mild symptoms, and four were normal. There was a significant correlation between the cerebral concentrations of PCr or ATP at birth and outcome (r = 0.8, p < 0.001) and between the degree of neonatal neurologic depression and outcome (r = 0.7). More important, the outcome of neonates with moderate HIE could better be predicted with information from quantitative 31P magnetic resonance spectroscopy than from neurologic examinations. In general, the accuracy of outcome predictability could significantly be increased by adding results from 31P magnetic resonance spectroscopy to the neonatal neurologic score, but not vice versa. No correlation with outcome was found for other perinatal risk factors, including Apgar score.

Asphyxia Neonatorum↗
PubMed1996

Inhaled nitric oxide selectively decreases pulmonary artery pressure and pulmonary vascular resistance following acute massive pulmonary microembolism in piglets.

Acute massive pulmonary embolism increases pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR), which may lead to early right ventricular failure and subsequent cardiocirculatory deterioration. Inhaled nitric oxide (NO) selectively dilates pulmonary vessels in vivo. Thus, inhaled NO may be useful in preventing cardiocirculatory deterioration following pulmonary embolism. We investigated the effects of inhaled NO in the acute phase of massive pulmonary microembolism in 10 anesthetized and mechanically ventilated piglets (body weight, 18 +/- 2 kg). Microspheres of 300-microns diameter were injected i.v. in an amount sufficient to initially increase mean PAP to 45 mm Hg. Forty-five minutes after pulmonary embolization, the pretreatment control values were recorded. Thereafter, the piglets inhaled 40 ppm NO, and subsequently 80 ppm NO. When 40 ppm NO was inhaled, there was a significant decrease in systolic PAP (-10.3%; 44.5 +/- 2.2 to 39.9 +/- 2.4 mm Hg; p < 0.05) and mean PAP (-9.4%; 32.9 +/- 1.3 to 29.8 +/- 1.3 mm Hg; p < 0.05). PVR was changed by -13.6% (p = 0.07). Administration of 80 ppm NO resulted in a significant decrease in systolic PAP (-12.6%; to 38.9 +/- 1.9 mm Hg; p < 0.05), mean PAP (-11.9%; to 29.0 +/- 1.4 mm Hg; p < 0.05), and PVR (-19.4%; p < 0.05) compared with pretreatment values. Discontinuation of NO inhalation was associated with an immediate return to pretreatment values. Systemic hemodynamics and the arterial and mixed venous oxygen concentrations remained unchanged. We conclude that inhaled NO following acute massive pulmonary microembolism selectively decreases PAP and PVR without influencing systemic hemodynamics in piglets.

Administration, Inhalation↗
PubMed1996

[A comparative study of the use of sevoflurane and propofol in ambulatory surgery].

UNLABELLED: Cost-containment strategies increase the demand for day-case surgery. In outpatients, a short time of stay in the post-anaesthesia care unit and a short interval to discharge home are of great importance. After general anaesthesia, mental and psychomotor functions are impaired to varying degrees by different anaesthetics. Therefore, the choice of anaesthetic may influence the discharge times of outpatients. In this study, the recovery characteristics of sevoflurane versus propofol anaesthesia were compared in adult outpatients. METHODS: With ethics committee approval and written informed consent, a total of 50 patients undergoing day-case ophthalmological or urological surgery were randomised into two groups. After a priming dose of vecuronium 0.015 mg/kg, anaesthesia was induced in all patients with propofol 2.0-2.5 mg/kg and fentanyl 2 micrograms/kg. Suxamethonium 1 mg/kg was used to provide muscle relaxation for endotracheal intubation. According to the randomisation, anaesthesia was maintained with either sevoflurane 1-3 vol.% (group 1, n = 25) or propofol (group 2, n = 25). The immediate postoperative recovery was assessed by the time to the appropriate response to different verbal commands. The quality of the overall postoperative recovery was classified by visual analogue scales, the digit-symbol substitution test (DSST), a modified Aldrete score, and the time until the ability to sit upright and walk. Overall side effects and postoperative behaviour were evaluated by a telephone interview on the day after surgery. RESULTS: Neither the study groups nor the duration of surgical procedures differed significantly. The total doses of anaesthetic used were 1.7 +/- 1.1 MAC-h sevoflurane and 631 +/- 261 mg propofol, respectively. The time intervals from the end of anaesthesia to extubation of the trachea were significantly shorter after sevoflurane than after propofol (6.6 +/- 2 min vs. 9.8 +/- 6 min). Similar results were obtained for the intervals to eye opening (7.2 +/- 2 min vs. 12.6 +/- 9 min) and hand squeezing (8 +/- 2 min vs. 13.8 +/- 11 min). The recovery of cognitive functions was significantly faster after sevoflurane when compared to propofol as evidenced by the DSST. The modified Aldrete score was significantly better in the sevoflurane group at all assessment times. Except for 30 min after anaesthesia, when sevoflurane patients complained of significantly more nausea, VAS scores were not different. No significant difference in the ability to sit and walk was found. The side effects did not differ between both groups. CONCLUSION: The results indicate that in urological and ophthalmological day surgery, the early recovery and the return of mental and psychomotor function in the first 60 min after anaesthesia is faster following sevoflurane than after propofol. No differences in ambulation times became evident. Sevoflurane may offer clinical advantages over propofol when used for maintenance of anaesthesia during outpatient surgical procedures.

Adult↗
PubMed1996

Different effect of inhaled nitric oxide on yucatan micropig with and without congenital ventricular septal defect.

A strain of Yucatan micropigs is known to have heritable ventricular septal defects (VSDs) and thus may develop overflow pulmonary hypertension. Since inhaled nitric oxide (NO) selectively dilates pulmonary vessels, we determined its hemodynamic and co-agulatory effects in this new animal model. Eight Yucatan micropigs were anesthetized with midazolam, piritramide (a synthetic opioid) and vecuronium bromide. The presence and the size of the VSD were determined by using transesophageal color flow Doppler echocardiography. Four animals showed VSDs of 1-2 mm size. Inhaled NO was then administered with increasing inspired concentrations of 0, 5, 10, 20, 40, 80 and again 0 ppm NO for 10-min periods. NO inhalation did not affect heart rate, right cardiac output, mean arterial pressure, pulmonary arterial wedge pressure, or central venous pressure. Inhaled NO in animals with proven VSDs decreased pulmonary artery pressure (PAP) in a dose dependent manner; 5 ppm NO reduced mean PAP from 25 +/- 2.3 mm Hg to 18 +/- 0.8 mm Hg (p < 0.05), while pulmonary vascular resistance (PVR) decreased from 954 +/- 143 dyn.cm. s-5 to 661 +/- 88 dyn.cm.s-5 (p < 0.01) at the same dose. The maximum reduction in mean PAP and PVR occurred when 80 ppm NO was inhaled. Yucatan micropigs without VSDs did not respond hemodynamically to NO inhalation. Methemoglobin levels remained unchanged during the entire study. Platelet function was assessed according to the method of BREDDIN and BORN (BORN 1962). Initial aggregation and slope were affected when NO inhalation commenced. Yucatan micropigs with VSDs may represent a suitable model for further research of the in vivo effects of inhaled NO.

Administration, Inhalation↗
PubMed1996

[Documentation and therapeutic standards in anesthesia and intensive care medicine--means for quality assurance and cost control].

Patient data management in anaesthesia and intensive care should include besides medical data of individual patients economically important parameters, e.g. working time or cost of material. Integration of this data management system in the hospital information network enables case-oriented analyses for costs in relation to outcome. Standards of therapy including cost-benefit estimates may be an approach to improve the quality of care and to control the cost of medical care, in particular in the setting of teaching hospitals, avoiding erratic and costly orders by staff in training.

Anesthesia↗
PubMed1996

[pHi value as a prognostic parameter in septic and polytrauma patients].

In 17 patients in septic shock and in 12 trauma patients (ISS > or = 20) the gastric pHi and systemic oxygen delivery and consumption were measured every 6 h to evaluate the prognostic significance of the pHi and to determine the relationship between the gastric mucosal oxygenation and the systemic oxygen transport parameters. In the trauma patient the initial pHi has a high prognostic significance (mean survivors = 7.38; non-survivors = 7.15; p < 0.05), while in the septic group no patient with a pathologic pHi (< 7, 35) > or = 12 h survived. Since we found no correlation between pHi and systemic oxygen transport parameters, other factors have to be of greater importance for gut mucosal oxygenation.

Critical Care↗
PubMed1995

Inducible nitric oxide synthase: identification of amino acid residues essential for dimerization and binding of tetrahydrobiopterin.

Nitric oxide synthases (NOSs) require tetrahydrobiopterin (BH4) for dimerization and NO production. Mutation analysis of mouse inducible NOS (iNOS; NOS2) identified Gly-450 and Ala-453 as critical for NO production, dimer formation, and BH4 binding. Substitutions at five neighboring positions were tolerated, and normal binding of heme, calmodulin, and NADPH militated against major distortions affecting the NH2-terminal portion, midzone, or COOH terminus of the inactive mutants. Direct involvement of residues 450 and 453 in the binding of BH4 is supported by the striking homology of residues 448-480 to a region extensively shared by the three BH4-utilizing aromatic amino acid hydroxylases and is consistent with the conservation of these residues among all 10 reported NOS sequences, including mammalian NOSs 1, 2, and 3, as well as avian and insect NOSs. Altered binding of BH4 and/or L-arginine may explain how the addition of a single methyl group to the side chain of residue 450 or the addition of three methylenes to residue 453 can each abolish an enzymatic activity that reflects the concerted function of 1143 other residues.

Amino Acid Sequence↗
PubMed1995

Loss of heterozygosity in the chromosomal region 12p12-13 is very common in childhood acute lymphoblastic leukemia and permits the precise localization of a tumor-suppressor gene distinct from p27KIP1.

Abnormalities of the short arm of chromosome 12 are relatively common in hematologic malignancies and deletions of the region. 12p12-13 are found in approximately 5% of the patients with acute lymphoblastic leukemia (ALL). As a potent inhibitor of cyclin-dependent kinases, p27KIP1 prevents the progression of the cell cycle and the gene encoding p27KIP1 represents a potential tumor-suppressor gene. Its recent assignment to the chromosomal region (12p12.3) prompted us to study the p27KIP1 gene in a series of 61 children with ALL. Microsatellite polymorphic markers flanking the p27KIP1 gene were analyzed to detect losses of heterozygosity (LOH). Eleven patients displayed LOH for at least one of the markers. The deleted are encompassed the p27KIP1 gene locus in 10 cases, but inactivation of the remaining allele by deletion, translocation, or mutation was never observed. In addition, in 1 patient, the p27KIP1 gene was situated outside of the region of LOH. Thus, p27KIP1 does not seem to be the target gene of 12p12-13 alterations. However, this study indicates that 12p12-13 alterations at the molecular level, which are present in about 27% of the children with B-lineage ALL, are much more common than had previously been reported by usual chromosome analysis. Moreover, LOH mapping allowed us to better define the location of a putative tumor-suppressor gene implicated in these malignancies and should therefore help in identifying this gene.

Base Sequence↗
PubMed1995

Activation of blood coagulation after cardiac arrest is not balanced adequately by activation of endogenous fibrinolysis.

BACKGROUND: Animal studies have demonstrated that hemostatic disorders occurring after cardiac arrest affect outcome. We investigated hemostatic changes during and after cardiopulmonary resuscitation (CPR) in humans. METHODS AND RESULTS: The prospective study included 23 patients (29 to 86 years) who underwent out-of-hospital CPR for nontraumatic causes. Blood samples were drawn immediately and 15 and 30 minutes after initiation of CPR. In the case of restoration of spontaneous circulation (ROSC; n = 7), additional blood samples were taken immediately, 30 minutes, and 2, 8, 24, 48, and 72 hours after ROSC. A marked activation of blood coagulation was found in all patients. The specific markers of activated blood coagulation and fibrin formation, thrombin-antithrombin complex (TAT; median during CPR, 260 micrograms/L; median after ROSC, 57 micrograms/L; normal range, 1.0 to 4.1 micrograms/L), and fibrin monomers (FM; median during CPR, 34.3 micrograms/mL; median after ROSC, 65.4 micrograms/mL; normal range, 0 to 3.6 micrograms/mL) were markedly increased during and in the early phase after CPR. When patients survived for 48 hours, TAT and FM values returned to the normal range. In most patients, the plasma levels of D-dimer, an indicator of endogenous fibrinolytic activity, were not markedly increased during CPR (median, < 0.25 microgram/mL; normal range, < 0.25 microgram/mL) but increased moderately after ROSC (median, 0.56 microgram/mL). Levels of plasminogen activator inhibitor type 1 (normal range, 0.3 to 3.5 U/mL), a marker for endogenous inhibition of fibrinolytic activity, were moderately increased in most patients (median during CPR, 4.22 U/mL; median after ROSC, 8.08 U/mL). CONCLUSIONS: Our data clearly demonstrate that there is a marked activation of blood coagulation and fibrin formation after prolonged cardiac arrest and CPR in humans that is not balanced adequately by concomitant activation of endogenous fibrinolysis. These changes may contribute to reperfusion disorders, such as the cerebral "no-reflow" phenomenon, by inducing fibrin deposition and formation of microthrombi.

Adult↗
PubMed1995

Defensins and other endogenous peptide antibiotics of vertebrates.

Gene-encoded peptide antibiotics are ubiquitous components of host defenses in mammals, birds, amphibia, insects, and plants. Their de novo synthesis or release from storage sites can be induced rapidly, which makes them particularly important in the initial phases of resistance to microbial invasion. The endogenous antimicrobial peptides of animals are products of single genes and are synthesized as preproproteins. Multistep processing yields the mature peptide, which generally acts by inducing microbial membrane permeabilization. Several families of antimicrobial peptides have been identified that differ with respect to the presence of disulfide linkages, amino acid composition, structural conformation, and spectrum of activity. The arginine-rich three disulfide-containing beta-sheet defensins are remarkably abundant and widely distributed in animals and plants. The antibiotic peptides of higher eukaryotes merit further study for their role in natural immunity and their potential as novel therapeutic compounds.

Amino Acid Sequence↗
PubMed1995

Recovery characteristics following anaesthesia with sevoflurane or propofol in adults undergoing out-patient surgery.

The aim of the study was to compare recovery characteristics in adult patients following general anaesthesia either with the new investigational volatile agent sevoflurane or with propofol. Accordingly, two groups of 25 adults undergoing outpatient surgery were entered into a prospective, randomised study. Patients who received sevoflurane were extubated at an earlier stage than those receiving propofol (6.6 vs. 9.8 min), and the times to eye opening (7.2 vs. 12.6 min) and hand squeezing (8.2 vs 13.8 min) were also shorter. As measured by the digit-symbol substitution test, patients regained the pre-operative level of cognitive function significantly earlier after sevoflurane anaesthesia. Modified Aldrete scores were also higher in this group within the first hour after anaesthesia than in the propofol group. Sevoflurane appears to be a useful alternative to propofol in outpatient anaesthesia.

Adult↗
PubMed1995

Localization of the CDKN4/p27Kip1 gene to human chromosome 12p12.3.

CDKN4/p27Kip1 is a cyclin-dependent kinase (Cdk) inhibitor implicated in G1 phase arrest, which negatively regulates G1 phase progression in response to TGF beta, and might represent a tumor suppressor gene. We report here the chromosomal assignment of the human CDKN4 gene to chromosome 12p12.3 in close proximity to highly polymorphic microsatellite markers.

Base Sequence↗