Modeling of the heat distribution in the intervertebral disk

The heat transfer equation was used to model the heat distribution in an intervertebral disk during ultrasound (US) exposure. The influence of thermal and acoustic parameters was studied to get a quantitative understanding of the heat transfer in the system. Heating of collagen to 65 degrees C or above will lead to denaturation and is believed to stabilize and contract the outer part of the disk in a herniated disk. In our model, the US intensity was approximated by a Gaussian distribution and nonlinear propagation was excluded. The effect of self-heating and cooling of the transducer was also studied. The simulations were performed using the finite element method. From this model, it can be concluded that it is possible to heat parts of the disk to treatment temperature using a focused 5-mm diameter US probe. The physical constraints on the piezocrystal set the limit of the size of the treatment volume.

Development and use of fluorescent nanosensors for metabolite imaging in living cells

To understand metabolic networks, fluxes and regulation, it is crucial to be able to determine the cellular and subcellular levels of metabolites. Methods such as PET and NMR imaging have provided us with the possibility of studying metabolic processes in living organisms. However, at present these technologies do not permit measuring at the subcellular level. The cameleon, a fluorescence resonance energy transfer (FRET)-based nanosensor uses the ability of the calcium-bound form of calmodulin to interact with calmodulin binding polypeptides to turn the corresponding dramatic conformational change into a change in resonance energy transfer between two fluorescent proteins attached to the fusion protein. The cameleon and its derivatives were successfully used to follow calcium changes in real time not only in isolated cells, but also in living organisms. To provide a set of tools for real-time measurements of metabolite levels with subcellular resolution, protein-based nanosensors for various metabolites were developed. The metabolite nanosensors consist of two variants of the green fluorescent protein fused to bacterial periplasmic binding proteins. Different from the cameleon, a conformational change in the binding protein is directly detected as a change in FRET efficiency. The prototypes are able to detect various carbohydrates such as ribose, glucose and maltose as purified proteins in vitro. The nanosensors can be expressed in yeast and in mammalian cell cultures and were used to determine carbohydrate homeostasis in living cells with subcellular resolution. One future goal is to expand the set of sensors to cover a wider spectrum of metabolites by using the natural spectrum of bacterial periplasmic binding proteins and by computational design of the binding pockets of the prototype sensors.

Volume expansion of albumin, gelatin, hydroxyethyl starch, saline and erythrocytes after haemorrhage in the rat

OBJECTIVE

To compare the colloids 5% albumin, 4% gelatin and 6% hydroxyethyl starch (HES) 130/0.4 with each other and with saline, regarding their plasma-expanding effects after haemorrhage; these were also compared with the intravascular volume-expanding effect of re-transfusion with erythrocytes.

DESIGN

Controlled, prospective, randomised laboratory study.

SETTING

University research laboratory.

SUBJECTS

Thirty-five adult rats.

INTERVENTIONS

Plasma volume was determined (I(125) albumin tracer technique) after haemorrhage of 20 ml/kg and 3 h after a bolus infusion of 20 ml/kg of each of the colloids or 80 ml/kg of saline, or 6.7 ml/kg of erythrocytes diluted in 9 ml/kg of saline. Blood pressure, haematocrit (Hct), blood gases and physiological parameters were measured.

MEASUREMENTS AND RESULTS

Plasma volume after haemorrhage was 29.6+/-2.6 ml/kg (n=35). With the bolus infusion, plasma volume increased by 21.1+/-3.6 ml/kg in the albumin group (n=7), by 13.1+/-2.9 ml/kg in the gelatin group (n=7), by 13.8+/-2.2 ml/kg in the HES group (n=7), by 16.0+/-2.4 ml/kg in the saline group (n=7) and by 6.9+/-2.3 ml/kg in the erythrocyte group (n=7) 3 h after the infusion. In the latter group, there was a total increase in intravascular volume of 13.6+/-2.5 ml/kg including the erythrocyte volume. Arterial pressure was better preserved in the albumin and erythrocyte groups than in the other groups.

CONCLUSION

Albumin 5% was a more effective plasma volume expander than gelatin and HES. Saline, with a four times larger volume, and erythrocytes in about 1/3 of the volume had a similar volume-expanding effect to gelatin and HES.

Vasopeptidase inhibition with omapatrilat increases fluid and protein microvascular permeability in cat skeletal muscle

BACKGROUND

Vasopeptidase inhibition is a new antihypertensive approach combining inhibition of angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP), but severe oedema, mainly angio-oedema, has been reported. As ACE and NEP catalyse degradation of the permeability-increasing peptide bradykinin, and NEP also catalyses degradation of permeability-increasing peptides such as atrial natriuretic peptide, substance P, endothelin-1 and angiotensin II, vasopeptidase inhibition may increase microvascular permeability.

OBJECTIVE

To analyse the effects of vasopeptidase inhibition on permeability.

DESIGN

The study was performed on the autoperfused cat calf skeletal muscle, evaluating the effects on fluid and protein permeability of a clinically relevant dose of the vasopeptidase inhibitor, omapatrilat. The effects were compared with those of the vehicle, of selective ACE and NEP inhibition, and of omapatrilat during bradykinin receptor blockade.

METHODS

Effects on fluid permeability were determined with a capillary filtration coefficient (CFC) technique, and effects on protein permeability were assessed from changes in the osmotic reflection coefficient for albumin.

RESULTS

After 1.5 h of intravenous infusion of omapatrilat (0.35 mg/kg per hour), mean arterial pressure was reduced from 114 mmHg to 86 mmHg (P < 0.01) and skeletal muscle vascular resistance was reduced from 14.5 peripheral resistance units (PRU) to 11.5 PRU (P < 0.05). CFC was increased by 22% (P < 0.01) and the reflection coefficient was decreased by 17% (P < 0.01). Infusion of vehicle had no effects. Inhibition of NEP increased permeability without affecting blood pressure, whereas ACE inhibition decreased blood pressure without affecting permeability. The increase in permeability associated with omapatrilat was reduced by bradykinin blockade.

CONCLUSIONS

A clinically relevant antihypertensive dose of omapatrilat reduces vascular resistance and increases fluid and protein permeability, the permeability effect more by inhibition of NEP than by inhibition of ACE, by a mechanism involving bradykinin.

Should euthanasia be legal? An international survey of neonatal intensive care units staff

OBJECTIVE

To present the views of a representative sample of neonatal doctors and nurses in 10 European countries on the moral acceptability of active euthanasia and its legal regulation.

DESIGN

A total of 142 neonatal intensive care units were recruited by census (in the Netherlands, Sweden, Hungary, and the Baltic countries) or random sampling (in France, Germany, Italy, Spain, and the United Kingdom); 1391 doctors and 3410 nurses completed an anonymous questionnaire (response rates 89% and 86% respectively).

MAIN OUTCOME MEASURE

The staff opinion that the law in their country should be changed to allow active euthanasia "more than now".

RESULTS

Active euthanasia appeared to be both acceptable and practiced in the Netherlands, France, and to a lesser extent Lithuania, and less acceptable in Sweden, Hungary, Italy, and Spain. More then half (53%) of the doctors in the Netherlands, but only a quarter (24%) in France felt that the law should be changed to allow active euthanasia "more than now". For 40% of French doctors, end of life issues should not be regulated by law. Being male, regular involvement in research, less than six years professional experience, and having ever participated in a decision of active euthanasia were positively associated with an opinion favouring relaxation of legal constraints. Having had children, religiousness, and believing in the absolute value of human life showed a negative association. Nurses were slightly more likely to consider active euthanasia acceptable in selected circumstances, and to feel that the law should be changed to allow it more than now.

CONCLUSIONS

Opinions of health professionals vary widely between countries, and, even where neonatal euthanasia is already practiced, do not uniformly support its legalisation.

Endogenous nitric oxide reduces microvascular permeability and tissue oedema during exercise in cat skeletal muscle

Based on a proposed increase in the release of the vasodilators nitric oxide (NO) and prostacyclin during exercise, and the fact that these substances have vascular permeability-reducing properties, this study was designed to evaluate (1) possible effects of exercise on hydraulic permeability, (2) whether permeability and muscle swelling are reduced by an increased release of NO and prostacyclin during exercise and (3) whether NO and prostacyclin are involved in exercise hyperaemia. The study was performed on an autoperfused cat calf muscle preparation with ligated lymph vessels, and exercise was induced by somatomotor nerve stimulation. Change in microvascular hydraulic permeability was estimated by a capillary filtration coefficient (CFC) technique. We found that the marked muscle volume increase after the start of the exercise gradually decreased, reaching an isovolumetric state within 25 min where CFC had decreased by about 25% (p < 0.05). CFC recovered completely after exercise was stopped. The decrease in CFC was abolished during blockade of endogenous NO by the NO synthase inhibitor L-NAME, but was preserved during blockade of endogenous prostacyclin by tranylcypromine. The muscle volume increase during exercise was about 60% greater with L-NAME than during vehicle or tranylcypromine (p < 0.01). Neither L-NAME nor tranylcypromine had any effect on exercise hyperaemia. We conclude that microvascular hydraulic permeability is reduced during exercise, that this effect reduces exercise-induced muscle swelling, and that the effects are mediated via release of NO. NO and prostacyclin are not involved in exercise hyperaemia.

Cardiovascular autonomic neuropathy associated with carotid atherosclerosis in Type 2 diabetic patients

AIMS

To clarify if cardiovascular autonomic neuropathy is associated with carotid artery atherosclerotic plaques in Type 2 diabetic patients.

METHODS

Cardiovascular autonomic nerve function was related to carotid artery ultrasound in 61 Type 2 diabetic patients 5-6 years after diagnosis of diabetes.

RESULTS

Cardiovascular autonomic neuropathy [abnormal age corrected expiration/inspiration (E/I) ratio or acceleration index (AI)] was found in 13/61 (21%) patients. Patients with cardiovascular autonomic neuropathy showed increased degree of stenosis in the common carotid artery (24.6 +/- 13.2% vs. 14.7 +/- 9.2%; P = 0.014) and a tendency towards a higher plaque score (4.0 +/- 1.7 vs. 3.2 +/- 1.6; P = 0.064). Controlled for age, AI correlated inversely with degree of stenosis (r = -0.39; P = 0.005), plaque score (r = -0.39; P = 0.005), and mean (r = -0.33; P = 0.018) and maximum (r = -0.39; P = 0.004) intima-media thickness in the common carotid artery. In contrast, E/I ratio correlated only slightly with mean intima-media thickness in the common carotid artery (r = -0.28; P = 0.049).

CONCLUSIONS

Cardiovascular autonomic neuropathy was associated with carotid atherosclerosis in Type 2 diabetic patients. Abnormal E/I ratios reflect efferent structural damage to parasympathetic nerves whereas abnormal AI reflects afferent autonomic dysfunction possibly due to impaired baroreceptor sensitivity secondary to carotid atherosclerosis.

Nitric oxide and prostacyclin play a role in the regulation of microvascular protein and hydraulic permeability in cat skeletal muscle

OBJECTIVE

To evaluate a possible role of nitric oxide (NO) and prostacyclin in the regulation of basal microvascular protein and hydraulic permeability.

METHODS

The study was performed on the autoperfused cat calf muscle. Changes in the osmotic reflection coefficient for albumin, calculated from the extended Starling equation, were used as a measure of altered protein permeability, whereas changes in capillary filtration coefficient (CFC) were used as a measure of altered hydraulic permeability.

RESULTS

Inhibition of the endogenous NO production with L-nitro-arginine methyl ester given intra-arterially to the muscle decreased the reflection coefficient to 70% of the control (p < 0.05) and increased the CFC by 17% (p < 0.05). The addition of a simultaneous intra-arterial infusion of the NO precursor L-arginine restored both the reflection coefficient and the CFC back to control level. Blockade of the endogenous prostacyclin production with tranylcypromine given intra-arterially decreased the reflection coefficient to 72% of the control (p < 0.05) and increased the CFC by 24% (p < 0.05), and they were both restored to control levels by a simultaneous intravenous infusion of a nonvasodilating dose of prostacyclin (1.0 ng/kg per minute).

CONCLUSIONS

The results support the view that endogenous NO and prostacyclin decrease both protein and hydraulic permeability. Assuming a dynamic endogenous release of these substances, they may act as bidirectional regulators of protein and hydraulic permeability.

Thoracic epidural anesthesia and epidural hematoma

This report involves a 74-year-old-male who developed a thoracic epidural hematoma with paraparesis on the second postoperative day in conjunction with thoracic epidural anesthesia established before surgery for acute abdominal aortic dissection. The finding indicates that laminectomy can be performed successfully as late as three days after diagnosis of the hematoma, with a complete restitution of neurological function. High-dose steroid treatment may have been a contributing factor for the positive outcome.

Ultrasound nucleolysis: an in vitro study

Thermal intradiscal therapy for chronic low back pain, using a catheter inserted into the intervertebral disc, is becoming more popular in the treatment of low back pain. The aim of this study was to investigate the possibility of heating the nucleus pulposus of the intervertebral disc with high-intensity focused ultrasound (US) or HIFU. Two specific situations were considered, invasive transducers that would be in contact with the annulus fibrosus of the disc, and noninvasive transducers that could be used externally. Theoretical simulations were performed to find the optimal parameters of US transducers and then experimental studies were done using transducers made to these specifications. These experiments confirmed that it was possible to heat the discs with HIFU. Two orthogonal transducers resulted in a superior temperature distribution than using just one transducer. It is, therefore, feasible to consider thermal treatment of the nucleus pulposus of the disc using noninvasive US.

Pharmacokinetics and non-analgesic effects of S- and R-ketamines in healthy volunteers with normal and reduced metabolic capacity

OBJECTIVE

There is a growing interest in low-dose ketamine as an analgesic agent in different intractable pain conditions. Due to its narrow therapeutic window, well-defined pharmacokinetic parameters are essential for its successful use in these situations. Arterial data for ketamine or its enantiomers have not been reported before. The metabolic pathways involved in the metabolism of S- and R-ketamines are not known.

METHODS

Ten healthy male volunteers received 7 mg infusions of R- and S-ketamine-hydrochloride in a randomised order over 30 min on 2 separate days. Six were extensive metabolisers, two were poor metabolisers of debrisoquine (CYP2D6) and two were poor metabolisers of mephenytoin (CYP2C19). Arterial and venous concentrations and non-analgesic side effects were measured.

RESULTS

Subjective side effects were mild but more pronounced for S- than for R-ketamine. There were no salient differences between the subjects with reduced and normal metabolic capacity in pharmacokinetic parameters or in side effects. Volumes of distribution and mean residence times were 40% smaller for arterial than for venous data. The mean clearance of R-ketamine, 0.020 l min(-1) kg(-1), was slightly but significantly lower than of S-ketamine, 0.024 l min(-1) kg(-1).

CONCLUSIONS

There are large differences between arterial and venous data in the pharmacokinetic parameters that are heavily dependent on distribution processes. Parameters mainly reflecting elimination, such as clearance and area under the concentration time curve, are unchanged. The choice of sampling site could be important when computer-controlled infusions are used.

Isolated hypervariable regions derived from streptococcal M proteins specifically bind human C4b-binding protein: implications for antigenic variation

Antigenic variation in microbial surface proteins represents an apparent paradox, because the variable region must retain an important function, while exhibiting extensive immunological variability. We studied this problem for a group of streptococcal M proteins in which the approximately 50-residue hypervariable regions (HVRs) show essentially no residue identity but nevertheless bind the same ligand, the human complement regulator C4b-binding protein (C4BP). Synthetic peptides derived from different HVRs were found to retain the ability to bind C4BP, implying that the HVR corresponds to a distinct ligand-binding domain that can be studied in isolated form. This finding allowed direct characterization of the ligand-binding properties of isolated HVRs and permitted comparisons between different HVRs in the absence of conserved parts of the M proteins. Affinity chromatography of human serum on immobilized peptides showed that they bound C4BP with high specificity and inhibition experiments indicated that different peptides bound to the same site in C4BP. Different C4BP-binding peptides did not exhibit any immunological cross-reactivity, but structural analysis suggested that they have similar folds. These data show that the HVR of streptococcal M protein can exhibit extreme variability in sequence and immunological properties while retaining a highly specific ligand-binding function.

Binding of human C4BP to the hypervariable region of M protein: a molecular mechanism of phagocytosis resistance in Streptococcus pyogenes

The amino-terminal hypervariable region (HVR) of streptococcal M protein is required for the ability of this virulence factor to confer phagocytosis resistance. The function of the HVR has remained unknown, but the finding that many HVRs with extremely divergent sequences bind the human complement regulator C4b-binding protein (C4BP) has suggested that this ligand may play a role in phagocytosis resistance. We used the M22 system to study the function of bound C4BP and provide several lines of evidence that C4BP indeed contributes to phagocytosis resistance. First, the ability of anti-HVR antibodies to cause opsonization correlated with their ability to inhibit binding of C4BP. Secondly, a short deletion in the HVR eliminated C4BP binding and also reduced the ability of M22 to confer phagocytosis resistance. Thirdly, the addition of an excess of pure C4BP to a phagocytosis system almost completely blocked the effect of opsonizing anti-HVR antibodies. Together, our data indicate that binding of C4BP to the HVR of M22 plays an important role in phagocytosis resistance, but other properties of M22 also contribute. This study provides the first molecular insight into the mechanisms by which the HVR of an M protein confers phagocytosis resistance.

Neuropeptides in the duodenal mucosa of chronic alcoholic heavy drinkers

Previous studies have shown that patients with chronic alcohol ingestion may show a variety of morphological and functional alterations in the small intestine. In this study, we have focused on the neuroendocrine system in the duodenal mucosa in chronic alcoholics; an area little studied. Twenty-three defined chronic alcoholics admitted to the hospital for detoxification underwent clinical examination, followed by upper gastrointestinal endoscopy and blood tests on average 4 days after the most recent alcohol intake. Biopsy specimens were taken from the distal part of the descending duodenum for both immunohistochemical and routine histological examination. The control group consisted of 25 patients referred for upper endoscopy mainly because of dyspepsia (ulcer, reflux type), but who were otherwise healthy. A normal carbohydrate-deficient transferrin and a history of low alcohol consumption (<40 g/week) were required for inclusion in the control group. The tissue specimens were studied using antisera for the following neuropeptides: cholecystokinin, galanin, gastric inhibitory peptide (GIP), glucagon, motilin, neuropeptide Y, pituitary adenylyl cyclase activating peptide, secretin, serotonin, somatostatin, substance P, vasoactive intestinal polypeptide and protein gene product, as a general marker for neurones and cells of the diffuse neuroendocrine system. The density of nerve fibres was evaluated semi-quantitatively and the number of endocrine cells per unit length of mucosa was counted in sections cut perpendicularly to the mucosal surface. All the different peptidergic nerve fibres in the alcohol group showed higher densities than the corresponding controls. However, this was not a statistically significant difference. A slightly significant increase (P = 0.02) in the numbers of glucagon and GIP cells was seen in the alcohol group. Gastrointestinal symptoms were frequently present (87%) in chronic alcoholics. We suggest that chronic alcohol consumption in man may have a general effect on the peptidergic nerve system and some endocrine cell types in the duodenal mucosa.

An ultra-short perineal pad-test for evaluation of female stress urinary incontinence treatment

We assessed the reproducibility and feasibility of a rapid perineal pad-test designed for evaluation of stress urinary incontinence treatment. In an experimental study, we included 34 women with genuine stress incontinence, 13 with urge incontinence and 10 non-incontinent volunteers for a repeated pad-test with a standardized bladder volume (300 mL) and a standardized physical activity during one minute. The pad was weighed before and after the exercise to estimate the volume of any leaked urine. In order to find out the percentage of unselected, incontinent women who had been able to perform a preoperative pad-test, we identified all 120 women operated on for stress incontinence during a one-year period in a separate retrospective analysis. In another retrospective analysis, we compared the subjective outcome of laparoscopic colposuspension with the outcome of the test performed before and after the procedure among 93 women with genuine stress incontinence. Among stress incontinent women, the median of the differences in leakage between the first and the second test was 8.5 mL (range 0-60 mL) and the repeatability coefficient was 33.6 mL. None of the 13 women with urge incontinence leaked during the tests. One of the 10 controls leaked (during both tests). Of the unselected women, 104/120 (87%) were able to perform the test. Reduction of leaking after surgery was significantly associated with subjective report of outcome (P < 0.0001). In conclusion, the described pad-test has an acceptable reproducibility and feasibility making it suitable for follow-up studies.

Aqueous polymer two-phase systems formed by new thermoseparating polymers

A set of new polymers that can be used as phase forming components in aqueous two-phase systems is presented. All polymers studied have thermoseparating properties i.e. form one separate polymer enriched phase and one aqueous solution when heated above the critical temperature. This property makes the polymers attractive alternatives to the polymers used in traditional aqueous two-phase systems such as poly(ethylene glycol) (PEG) and dextran. The thermal phase separation simplifies recycling of the polymers, thus making the aqueous two-phase systems more cost efficient and suitable for use in large scale. Thermoseparating polymers studied have been copolymers of ethylene oxide and propylene oxide (EO-PO), poly (N-isopropylacrylamide) (poly-NIPAM), poly vinyl caprolactam (poly-VCL) and copolymers of N-isopropylacrylamide and vinyl caprolactam with vinyl imidazole (poly(NIPAM-VI) and poly(VCL-VI), respectively). In addition, the copolymer poly(NIPAM-VI) has the property to be uncharged at pH above 7.0 and positively charged at lower pH. This allows the partitioning of protein to be directed by changing the pH in the system instead of the traditional addition of salt to direct the partitioning. Hydrophobically modified EO-PO copolymer (HM-(EO-PO)) with alkyl groups (C14) at both ends forms two-phase system with for example poly(NIPAM-VI). The phase diagram for poly(NIPAM-VI)/HM-(EO-PO) was determined and the model proteins lysozyme and BSA were partitioned in this system. For BSA in poly(NIPAM-VI)/HM-(EO-PO) system a change in pH from 8.0 to 5.4 results in a change of partition coefficient from K = 0.8 to K = 5.1, i.e. BSA could be transferred from the HM-(EO-PO) phase to the poly(NIPAM-VI) phase. BSA partitioning in poly(NIPAM-VI)/HM-(EO-PO) system allows quantitative BSA recovery, and recoveries of poly(NIPAM-VI) and HM-(EO-PO) were 53% and 92%, respectively, after the thermoseparation step.

Anaerobic desulfurization of ground rubber with the thermophilic archaeon Pyrococcus furiosus--a new method for rubber recycling

The anaerobic sulfur-reducing archaeon Pyrococcus furiosus was investigated regarding its capacity to desulfurize rubber material. The microorganism's sensitivity towards common rubber elastomers and additives was tested and several were shown to be toxic to P. furiosus. The microorganism was shown to utilize sulfur in vulcanized natural rubber and an increase in cell density was obtained when cultivated in the presence of spent tire rubber. Ethanol-leached cryo-ground tire rubber treated with P. furiosus for 10 days was vulcanized together with virgin rubber material (15% w/w) and the mechanical properties of the resulting material were determined. The increase in the stress at break value and the decrease in swell ratio and stress relaxation rate obtained for material containing microbially treated rubber (compared to untreated material) show the positive effects of microbial desulfurization on rubber.

Neonatal end-of-life decision making: Physicians' attitudes and relationship with self-reported practices in 10 European countries

CONTEXT

The ethical issues surrounding end-of-life decision making for infants with adverse prognoses are controversial. Little empirical evidence is available on the attitudes and values that underlie such decisions in different countries and cultures.

OBJECTIVE

To explore the variability of neonatal physicians' attitudes among 10 European countries and the relationship between such attitudes and self-reported practice of end-of-life decisions.

DESIGN AND SETTING

Survey conducted during 1996-1997 in 10 European countries (France, Germany, Italy, the Netherlands, Spain, Sweden, the United Kingdom, Estonia, Hungary, and Lithuania).

PARTICIPANTS

A total of 1391 physicians (response rate, 89%) regularly employed in 142 neonatal intensive care units (NICUs).

MAIN OUTCOME MEASURES

Scores on an attitude scale, which measured views regarding absolute value of life (score of 0) vs value of quality of life (score of 10); self-report of having ever set limits to intensive neonatal interventions in cases of poor neurological prognosis.

RESULTS

Physicians more likely to agree with statements consistent with preserving life at any cost were from Hungary (mean attitude scores, 5.2 [95% confidence interval ¿CI¿, 4.9-5.5]), Estonia (4.9 [95% CI, 4.3-5.5]), Lithuania (5.5 [95% CI, 4.8-6.1]), and Italy (5.7 [95% CI, 5.3-6.0]), while physicians more likely to agree with the idea that quality of life must be taken into account were from the United Kingdom (attitude scores, 7.4 [95% CI, 7.1-7.7]), the Netherlands (7. 3 [95% CI, 7.1-7.5]), and Sweden (6.8 [95% CI, 6.4-7.3]). Other factors associated with having a pro-quality-of-life view were being female, having had no children, being Protestant or having no religious background, considering religion as not important, and working in an NICU with a high number of very low-birth-weight newborns. Physicians with scores reflecting a more quality-of-life view were more likely to report that in their practice, they had set limits to intensive interventions in cases of poor neurological prognosis, with an adjusted odds ratio of 1.5 (95% CI, 1.3-1.7) per unit change in attitude score.

CONCLUSIONS

In our study, physicians' likelihood of reporting setting limits to intensive neonatal interventions in cases of poor neurological prognosis is related to their attitudes. After adjusting for potential confounders, country remained the most important predictor of physicians' attitudes and practices. JAMA. 2000;284:2451-2459.

Treatment choices for extremely preterm infants: an international perspective

OBJECTIVE

To compare treatment choices of neonatal physicians and nurses in 11 European countries for a hypothetical case of extreme prematurity (24 weeks' gestational age, birth weight of 560 g, Apgar score of 1 at 1 minute).

STUDY DESIGN

An anonymous, self-administered questionnaire was completed by 1401 physicians (response rate, 89%) and 3425 nurses (response rate, 86%) from a large, representative sample of 143 European neonatal intensive care units. Italy, Spain, France, Germany, the Netherlands, Luxembourg, Great Britain, Sweden, Hungary, Estonia, and Lithuania participated.

RESULTS

Most physicians in every country but the Netherlands would resuscitate this baby and start intensive care. On subsequent deterioration of clinical conditions caused by a severe intraventricular hemorrhage, attitudes diverge: most neonatologists in Germany, Italy, Estonia, and Hungary would favor continuation of intensive care, whereas in the other countries some form of limitation of treatment would be the preferred choice. Parental wishes appear to play a role especially in Great Britain and the Netherlands. Nurses are more prone than doctors to withhold resuscitation in the delivery room and to ask parental opinion regarding subsequent treatment choices.

CONCLUSION

An extremely premature infant is regarded as viable by most physicians, whereas after deterioration of the clinical conditions decision-making patterns vary according to country. These findings have implications for the ethical debate surrounding treatment of infants of borderline viability and for the interpretation and comparison of international statistics.

Conjunction analysis of cortical activations common to encoding and retrieval

The notion of overlap between encoding and retrieval processes is central in cognitive theories of episodic memory, but to date most functional neuroimaging studies have emphasized differences between these processes. In the present study, overlap between encoding and retrieval processes was investigated by analyzing data from a positron emission tomography (PET) study of encoding and retrieval of different kinds of event information. Using a conjunction analysis, we specifically aimed at identifying overlap in activation patterns for encoding and retrieval of three classes of event information: item, temporal, and spatial. It was found that both encoding and retrieval of spatial information activated posterior parietal areas bilaterally. In addition, item encoding and retrieval were associated with increased activity in the right temporal pole, and temporal encoding and retrieval with left inferior frontal and left inferior temporal regions. These findings suggest that when specific episodic information is retrieved from memory, regions involved in encoding of the same information are engaged.

Obstetric risk factors for stress urinary incontinence: a population-based study

OBJECTIVE

To evaluate obstetric and maternal risk factors for stress urinary incontinence.

METHODS

We linked three national, Swedish, population-based registries with the use of unique personal identification numbers. All women born between 1932 and 1977 and operated on for stress urinary incontinence between 1987 and 1996 were identified from the Hospital Discharge Registry. This information was linked with the Medical Birth Registry (for the years 1973-1995), containing information on antenatal care, delivery, and the newborn, and the Fertility Registry (for the years 1932-1997), containing information on the number of children delivered by each Swedish woman. For determination of odds ratios (ORs) and approximate 95% confidence intervals (CIs), we used the Mantel-Haenszel method and a test-based method after suitable stratifications and exclusions.

RESULTS

Diabetes mellitus, body mass index (BMI), age at first delivery, parity, birth weight, and epidural analgesia were positively associated with incontinence surgery. In contrast, cesarean delivery, forceps/vacuum extraction, and episiotomy were negatively associated with incontinence surgery. No association was found between surgery for stress incontinence and age at last delivery, smoking during pregnancy, level of education, multiple birth, large perineal tear, or breech presentation at any vaginal delivery. The OR for incontinence surgery was similarly decreased for nulliparous women and for uniparous women delivered by elective cesarean.

CONCLUSION

Vaginal delivery, notably the first, is strongly associated with later surgery for stress incontinence, but the association is modified by maternal conditions and interventions during delivery. No association was found between surgery for stress incontinence and pregnancy per se.

Activity in motor areas while remembering action events

Episodic memory for simple commands is better following enacted than verbal encoding. This has been proposed to be due to the possibility to base retrieval on motor information. Here we used PET to test the hypothesis that motor brain areas show increased retrieval-related activity following enacted compared to verbal encoding. Brain activity was also monitored during retrieval after imaginary enactment during encoding. It was found that activity in the right motor cortex was maximal following encoding enactment, intermediate following imaginary encoding enactment, and lowest following verbal encoding. These findings provide support that one basis for the facilitating effect on memory performance of overt, and to a lesser degree covert, encoding enactment is the possibility to base retrieval on motor information.