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Biomedical subjects

S Trautner

Publications and source records attributed to S Trautner.

11 recordsLinked to original sources
PubMed2002

Comparison of nasopharyngeal aspirate and nasal swab specimens for detection of respiratory syncytial virus in different settings in a developing country.

OBJECTIVE: To compare detection of respiratory syncytial virus (RSV) for diagnostic purposes using nasopharyngeal aspirate (NPA) and nasal swabs (NS) in different clinical settings in a community study in Guinea-Bissau. METHOD: During 1996-98 paired specimens were obtained from 635 children under 5 years of age (median: 274 days; interquartile range: 144-453 days) with symptoms of lower respiratory infections (LRI). The specimens were analysed by an enzyme-linked immunosorbent assay for RSV antigen in Guinea-Bissau and re-analysed in Denmark using the same assay. The gold standard for RSV antigen detection was defined as any test being positive. RESULTS: RSV antigen was detected in 84 (13%) children, the prevalence being 19% (41/219) among infants aged < 6 months, 12% (22/184) in infants aged 6-11 months, and 9% (21/230) in older children. Sensitivity of antigen detection was higher in NPA (92% in analyses in Guinea-Bissau and 98% in Denmark) than in NS (63% in analyses in Guinea-Bissau, 71% in Denmark). Specificity of RSV antigen detection was equally high in NPA and NS (99-100%). Time since onset of symptoms was significantly shorter in RSV antigen positive than negative samples. Sensitivity did not depend on clinical setting or age of the child. CONCLUSION: Using NS samples was associated with a 27-31% reduction in sensitivity compared with NPA specimens. As NPAs are costly and considered a nuisance by the population, it might be cost-effective in larger epidemiological studies to lose 25-30% in sensitivity but be able to collect samples from a much larger population.

Antigens, Viral↗
PubMed2002

Thymus size at birth is associated with infant mortality: a community study from Guinea-Bissau.

UNLABELLED: A few studies have suggested that thymus atrophy is associated with severe malnutrition and increased morbidity; however, no study of thymus size has been undertaken in countries with high mortality. This study examined the relation between thymus size at birth and subsequent mortality in an urban West African community. The size of the thymus was assessed by sonography as a volume estimate, the thymus index. A total of 278 children born at the local health centre in Bandim in Bissau, Guinea-Bissau, was enrolled in the study. Children were followed to the age of 2 y. Thymus size at birth was associated with most strongly weight, as well as with length and arm circumference. Controlling for weight and other risk factors, boys had larger thymus indices than girls [means ratio (MR) = 1.07, 95% confidence interval (95% CI) 1.01-1.14)]. Thymus size was also associated with prematurity, ethnic group, season and investigator, but not with birth order, mother's age, socioeconomic factors or the use of health services. Infant mortality was 117/1000. In a multivariate analysis, excluding premature infants and adjusting for age, gender, ethnic group, season of birth and investigator, higher birthweight (MR = 0.35, 95% CI 0.16-0.74) and larger thymus size (MR = 0.17, 95% CI 0.06-0.48) were independently associated with lower infant mortality. When both indices were estimated in the same model, the thymus index was associated with infant mortality (MR = 0.27, 95% CI 0.07-1.00), whereas birthweight had a non-significant effect (MR = 0.59, 95% CI 0.24-1.47). After 1 y of age neither birthweight nor thymus size at birth was associated with mortality. CONCLUSION: As all deaths were due to infectious diseases, thymus size at birth may be an important predictor of immune competence. Future studies should examine the determinants of thymus growth.

Analysis of Variance↗
PubMed2001

Endothelium-dependent vasorelaxation in inhibited by in vivo depletion of vascular thiol levels: role of endothelial nitric oxide synthase.

Thiols like glutathione may serve as reducing cofactors in the production of nitric oxide (NO) and protect NO from inactivation by radical oxygen species. Depletion of thiol compounds reduces NO-mediated vascular effects in vitro and in vivo. The mechanisms underlying these actions are not clear, but may involve decreased synthesis of NO and/or increased degradation of NO. This study investigates the effect of glutathione depletion on the response to NO-mediated vasodilation induced by acetylcholine (Ach, 10 micrograms/kg), endothelial NO synthase (eNOS) activity and potential markers of vascular superoxide anion (O2.-) production in conscious chronically catheterized rats. Thiol depletion induced by buthionine sulfoximine (BSO, 1 g i.p. within 24 h) decreased the hypotensive effect of Ach by 30% (MAP reduction before BSO 27 +/- 3 mmHg, 19 +/- 3 mmHg after BSO, (mean +/- SEM), p < .05, n = 8). The impaired effect of Ach was associated with a significant reduction in eNOS activity (control: 7.7 +/- 0.8, BSO: 3.9 +/- 0.4 pmol/min/mg protein (p < .05), n = 6). In contrast, neither NADH/NADPH driven membrane-associated oxidases nor lucigenin reductase activity were significantly (p < .05) affected by BSO (BSO: 4415 +/- 123, control: 4105 +/- 455 counts/mg; n = 6) in rat aorta. It is concluded that in vivo thiol depletion results in endothelial dysfunction and a reduced receptor-mediated vascular relaxation. This effect is caused by reduced endothelial NO formation.

Acetylcholine↗
PubMed2001

A mobile system for the treatment of accidental hypothermia with extracorporeal circulation.

When deep accidental hypothermia causes circulatory failure, the best chance of survival is treatment with extracorporeal circulation (ECC) and warming of the blood. This may be difficult to achieve if the patient is first admitted to a hospital without a department of thoracic surgery. Our aim was to test a lightweight mobile system for ECC. The equipment could be transported almost anywhere, making it possible to start ECC on the spot and during transfer. The system was tested on six hypothermic pigs, two of the pigs at the institute laboratory, two of the pigs in a normal ambulance, and two of the pigs in an air force rescue helicopter. All of the pigs were transported back to the institute for warming to normal temperature. After warming, and the ECC stopped, all the pigs were in sinus rhythm and had an obviously satisfactory circulation. It is possible to bring a lightweight ECC system to the unstable patient. Treatment is possible in any hospital, ambulance or helicopter.

Accidents↗
PubMed1998

Hydralazine-induced vasodilation involves opening of high conductance Ca2+-activated K+ channels.

The purpose of this study was to investigate whether high conductance Ca2+-activated K+ channels (BK(Ca)) are mediating the vasodilator action of hydralazine. In isolated porcine coronary arteries, hydralazine (1-300 microM), like the K+ channel opener levcromakalim, preferentially relaxed contractions induced by K+ (20 mM) compared with K+ (80 mM). In addition, concentration-relaxation curves for hydralazine (pD2 = 5.38 +/- 0.06; Emax = 85.9 +/- 3.6%) were shifted 10-fold to the right by the BK(Ca) blockers tetraethylammonium (1 mM) and iberiotoxin (0.1 microM). In contrast, nimodipine (a Ca2+-entry blocker), relaxed contractions induced by K+ (20 mM) and K+ (80 mM) equally and nimodipine-induced relaxations were neither antagonized by tetraethylammonium nor by iberiotoxin. In isolated perfused rat hearts, hydralazine (1 microM) increased coronary flow by 28.8 +/- 2.7%. Iberiotoxin (0.1 microM) suppressed this response by 82% (P < 0.05). In conscious, chronically catheterized rats the hypotensive response to hydralazine (0.6 mg kg(-1) min(-1)) was significantly reduced by 41% during infusion of iberiotoxin (0.1 mg kg(-1)). It is concluded, that opening of BK(Ca) takes part in the mechanism whereby hydralazine produces vasodilation.

Animals↗
PubMed1996

In vivo nitrate tolerance is not associated with reduced bioconversion of nitroglycerin to nitric oxide.

BACKGROUND: In vitro data suggest that reduced bioconversion of nitroglycerin (NTG) to nitric oxide (NO) contributes to the development of vascular and hemodynamic tolerance to NTG. We examined the in vivo validity of this hypothesis by measuring NTG-derived NO formation by in vivo spin-trapping of NO in vascular tissues from nitrate-tolerant and -nontolerant rats. METHODS AND RESULTS: Five groups (n = 6 to 8 each) of conscious chronically catheterized rats received NTG (0.2 or 1 mg/h IV) for 72 hours (nitrate-tolerant groups). Four other groups received either NTG vehicle (placebo, for 72 hours) or were left untreated (control). Nitrate tolerance was substantiated by a reduced (55% to 85%) hypotensive response to NTG in vivo and a reduced relaxation to NTG in isolated aortic rings. NTG-derived NO formation in aorta, vena cava, heart, and liver was measured as NOFe(DETC)2 and NO-heme complexes formed in vivo during 35 minutes combined with ex vivo cryogenic electron spin resonance spectroscopy. NO formation was significantly (P < .05) increased in all tissues in nitrate-tolerant rats in an NTG dose-dependent manner. Furthermore, the amount of NO formed from a bolus dose of NTG (6.5 mg/kg over 20 minutes) was similar in nitrate-tolerant and -nontolerant rats. CONCLUSIONS: The results suggest that vascular and hemodynamic NTG tolerance occurs despite high and similar rates of NO formation by NTG in tolerant and nontolerant target tissues. This finding is compatible with the assumption that reduced biological activity of NO, rather than reduced bioconversion of NTG to NO, contributes to in vivo development of nitrate tolerance.

Animals↗
PubMed1994

[Prehospital pain relief with nitrous oxide (Entonox)].

Many patients suffering from trauma or acute illness are in need of pain treatment in the prehospital phase, a treatment they seldom receive. In Denmark, it has been considered whether ambulance personnel should be allowed to administer pain treatment. Inhalation of 50% nitrous oxide and 50% oxygen has been administered for many years by non-physicians around the world. Therefore considerations concerning implementation of this treatment in Denmark are relevant. The aim of this paper was to evaluate the available knowledge about and experiences in using nitrous oxide outside the hospital for patients suffering from acute pain. The papers so far published are positive, but give no definite background for uncritical recommendation of prehospital pain treatment with nitrous oxide. There are no controlled studies concerning the effect of pain treatment in the prehospital phase. The few available controlled studies conducted inside the hospital have not shown significant pain-relieving effects of nitrous oxide for patients suffering from pain of acute medical of surgical origin when compared to other methods of pain treatment. Controlled studies of the effects of prehospital treatment with nitrous oxide need to be done. Technical problems and problems concerning indications, side effects, complications, pollution and possible addiction remain to be fully elucidated before prehospital treatment with nitrous oxide can be recommended for routine use in the Danish ambulances.

Administration, Inhalation↗
PubMed1986

Inflatable splints: do they cause tissue ischaemia?

The effect of increasing pneumatic splint pressure on cutaneous oxygen tension measured transcutaneously (TcPO2) was investigated in 12 subjects. The mean initial TcPO2 was 70.6 mmHg. TcPO2 decreased linearly on increasing the pressure within the splint. TcPO2 became zero at a mean splint pressure of 28 mmHg. Second, three accepted methods used by the ambulance crew to assess inflation pressures of the splint were investigated and found to be unreliable. In the light of these findings the risk of ischaemic complications as a result of applying pneumatic splints to a fractured limb is discussed. We advocate a recommended maximum splint pressure of 15 mmHg and that the splint should be manufactured with a security blow-off valve set at 15 mmHg.

Adult↗