"Virtual patch clamp analysis" for predicting the functional significance of pathogenic variants in sodium channels

OBJECTIVE

Opening of voltage-gated sodium channels is crucial for neuronal depolarization. Proper channel opening and influx of Na⁺ through the ion pore, is dependent upon binding of Na⁺ ion to a specific amino-acid motif (DEKA) within the pore. In this study we used molecular dynamic simulations, an advanced bioinformatic tool, to research the dysfunction caused by pathogenic variants in SCN1a, SCN2a and SCN8a genes.

METHOD

Molecular dynamic simulations were performed in six patients: three patients with Dravet syndrome (p.Gly177Ala,p.Ser259Arg and p.Met1267Ile, SCN1a), two patients with early onset drug resistant epilepsy(p.Ala263Val, SCN2a and p.Ile251Arg, SCN8a), and a patient with autism (p.Thr155Ala, SCN2a). After predicting the 3D-structure of mutated proteins by homology modeling, time dependent molecular dynamic simulations were performed, using the Schrödinger algorithm. The opening of the sodium channel, including the detachment of the sodium ion to the DEKA motif and pore diameter were assessed. Results were compared to the existent patch clamp analysis in four patients, and consistency with clinical phenotype was noted.

RESULTS

The Na⁺ ion remained attached to DEKA filter longer when compared to wild type in the p.Gly177Ala, p.Ser259Arg,SCN1a, and p.Thr155Ala, SCN2a variants, consistent with loss-of-function. In contrast, it detached quicker from DEKA than wild type in the p.Ala263Val,SCN2a variant, consistent with gain-of-function. In the p.Met1267Ile,SCN1a variant, detachment from DEKA was quicker, but pore diameter decreased, suggesting partial loss-of-function. In the p.Leu251Arg,SCN8a variant, the pore remained opened longer when compared to wild type, consistent with a gain-of-function. The molecular dynamic simulation results were consistent with the existing patch-clamp analysis studies, as well as the clinical phenotype.

SIGNIFICANCE

Molecular dynamic simulation can be useful in predicting pathogenicity of variants and the disease phenotype, and selecting targeted treatment based on channel dysfunction. Further development of these bioinformatic tools may lead to "virtual patch-clamp analysis".

Respiratory responses and rating of perceived exertion of severely obese adolescents during continuous and intermittent graded walking protocols: Application to cardiorespiratory field tests

During 20 m shuttle tests, obese adolescents may have difficulty achieving maximum cardiorespiratory performance due to the presence of braking-relaunch phases (BRP). Nineteen obese adolescents aged 15.2 ± 1.5 years (body mass index [BMI] = 39.7 ± 5.9 kg.m^-2) performed three graded walking exercises on a 50 m track at speeds between 3 and 6 km/h: a continuous-straight-line protocol (C), a continuous protocol that required turning back every 30 sec (C-BRP) and an intermittent protocol that consisted of successively walking then resting for 15 sec (15-15). Oxygen uptake (VO₂), aerobic cost of walking (Cw), ventilation (VE) and rating of perceived exertion (RPE) were measured at each stage during the protocols. During C-BRP, the responses were not significantly higher compared with C (p > 0.30). During 15-15, the VO₂, Cw and VE were ~ 15 to 25% lower than during C beginning at 4 km/h (p < 0.05). In obese adolescents, the respiratory impact of sudden directional changes during the 20 m shuttle-type test appeared to be minor at walking speeds. During the 15-15 test, the intensity increases more progressively, and this design may encourage obese adolescents to walk further than during a continuous test.

Acute cocoa flavanols intake improves cerebral hemodynamics while maintaining brain activity and cognitive performance in moderate hypoxia

INTRODUCTION

Acute cocoa flavanols (CF) intake has been suggested to modulate cognitive function and neurovascular coupling (NVC). Whether increased NVC is solely driven by improved vascular responsiveness or also by neuronal activity remains unknown. This study investigated the effects of acute CF intake on cognitive performance, NVC, and neuronal activity in healthy subjects in normoxia and hypoxia (4000 m simulated altitude; 12.7% O₂).

METHODS

Twenty healthy subjects (age 23.2 ± 4.3 years) performed four trials. Participants performed a Stroop task and "cognition" battery 2 h after acute CF (530 mg CF, 100 mg epicatechin) or placebo intake, and 30 min after initial exposure to hypoxia or normoxia. Electroencephalogram and functional near-infrared spectroscopy were used to analyze hemodynamic changes and neuronal activity.

RESULTS

CF enhanced NVC in the right prefrontal cortex during several tasks (risk decision making, visual tracking, complex scanning, spatial orientation), while neuronal activity was not affected. CF improved abstract thinking in normoxia, but not in hypoxia and did not improve other cognitive performances. Hypoxia decreased accuracy on the Stroop task, but performance on other cognitive tasks was preserved. NVC and neuronal activity during cognitive tasks were similar in hypoxia vs. normoxia, with the exception of increased β activity in the primary motor cortex during abstract thinking.

CONCLUSIONS

Acute CF intake improved NVC, but did not affect neuronal activity and cognitive performance in both normoxia and hypoxia. Most cognitive functions, as well as NVC and neuronal activity, did not decline by acute exposure to moderate hypoxia in healthy subjects.

Detection of copy number variations in epilepsy using exome data

Epilepsies are common neurological disorders and genetic factors contribute to their pathogenesis. Copy number variations (CNVs) are increasingly recognized as an important etiology of many human diseases including epilepsy. Whole-exome sequencing (WES) is becoming a standard tool for detecting pathogenic mutations and has recently been applied to detecting CNVs. Here, we analyzed 294 families with epilepsy using WES, and focused on 168 families with no causative single nucleotide variants in known epilepsy-associated genes to further validate CNVs using 2 different CNV detection tools using WES data. We confirmed 18 pathogenic CNVs, and 2 deletions and 2 duplications at chr15q11.2 of clinically unknown significance. Of note, we were able to identify small CNVs less than 10 kb in size, which might be difficult to detect by conventional microarray. We revealed 2 cases with pathogenic CNVs that one of the 2 CNV detection tools failed to find, suggesting that using different CNV tools is recommended to increase diagnostic yield. Considering a relatively high discovery rate of CNVs (18 out of 168 families, 10.7%) and successful detection of CNV with <10 kb in size, CNV detection by WES may be able to surrogate, or at least complement, conventional microarray analysis.

Insulin-based strategies to prevent hypoglycaemia during and after exercise in adult patients with type 1 diabetes on pump therapy: the DIABRASPORT randomized study

AIMS

To validate strategies to prevent exercise-induced hypoglycaemia via insulin-dose adjustment in adult patients with type 1 diabetes (T1D) on pump therapy.

METHODS

A total of 20 patients randomly performed four 30-min late post-lunch (3 h after lunch) exercise sessions and a rest session: two moderate sessions [50% maximum oxygen consumption (VO2 max)] with 50 or 80% basal rate (BR) reduction during exercise + 2 h and two intense sessions (75% VO2 max) with 80% BR reduction or with their pump stopped. Two additional early post-lunch sessions (90 min after lunch) were analysed to compare hypoglycaemia incidence for BR reduction versus bolus reduction.

RESULTS

In all, 100 late post-lunch sessions were analysed. Regardless of exercise type and BR reduction, no more hypoglycaemic events occurred in the period until the next morning than occurred after the rest sessions. In the afternoon, no more hypoglycaemic events occurred with 80% BR reduction/moderate exercise or with pump discontinuation/intense exercise than for the rest session, whereas more hypoglycaemic events occurred with 50% BR reduction/moderate exercise and 80% BR reduction/intense exercise. After early post-lunch exercise (n = 37), a trend towards fewer hypoglycaemic episodes was observed with bolus reduction versus BR reduction (p = 0.07). Mean blood glucose fell by ∼3.3 mmol/l after 30 min of exercise, irrespective of dose reduction, remaining stable until the next morning with no rebound hyperglycaemia.

CONCLUSION

In adults with T1D, to limit the hypoglycaemic risk associated with 30 min of exercise 3 h after lunch, without carbohydrate supplements, the best options seem to be to reduce BR by 80% or to stop the pump for moderate or intense exercise, or for moderate exercise 90 min after lunch, to reduce the prandial bolus rather than the BR.

The role of the endocannabinoid system in skeletal muscle and metabolic adaptations to exercise: potential implications for the treatment of obesity

The results of recent studies add the endocannabinoid system, and more specifically CB1 receptor signalling, to the complex mechanisms that negatively modulate insulin sensitivity and substrate oxidation in skeletal muscle. CB1 receptors might become overactive in the skeletal muscle during obesity due to increased levels of endocannabinoids. However, quite surprisingly, one of the most studied endocannabinoids, anandamide, when administered in a sufficient dose, was shown to improve muscle glucose uptake and activate some key molecules of insulin signalling and mitochondrial biogenesis. This is probably because anandamide is only a partial agonist at CB1 receptors and interacts with other receptors (PPARγ, TRPV1), which may trigger positive metabolic effects. This putative beneficial role of anandamide is worth considering because increased plasma anandamide levels were recently reported after intense exercise. Whether the endocannabinoid system is involved in the positive exercise effects on mitochondrial biogenesis and glucose fatty acid oxidation remains to be confirmed. Noteworthy, when exercise becomes chronic, a decrease in CB1 receptor expression in obese metabolically deregulated tissues occurs. It is then tempting to hypothesize that physical activity would represent a complementary alternative approach for the clinical management of endocannabinoid system deregulation in obesity, without the side effects occurring with CB1 receptor antagonists.

Intense exercise increases circulating endocannabinoid and BDNF levels in humans--possible implications for reward and depression

The endocannabinoid system is known to have positive effects on depression partly through its actions on neurotrophins, such as Brain-Derived Neurotrophic Factor (BDNF). As BDNF is also considered the major candidate molecule for exercise-induced brain plasticity, we hypothesized that the endocannabinoid system represents a crucial signaling system mediating the beneficial antidepressant effects of exercise. Here we investigated, in 11 healthy trained male cyclists, the effects of an intense exercise (60 min at 55% followed by 30 min at 75% W(max)) on plasma levels of endocannabinoids (anandamide, AEA and 2-arachidonoylglycerol, 2-AG) and their possible link with serum BDNF. AEA levels increased during exercise and the 15 min recovery (P<0.001), whereas 2-AG concentrations remained stable. BDNF levels increased significantly during exercise and then decreased during the 15 min of recovery (P<0.01). Noteworthy, AEA and BDNF concentrations were positively correlated at the end of exercise and after the 15 min recovery (r>0.66, P<0.05), suggesting that AEA increment during exercise might be one of the factors involved in exercise-induced increase in peripheral BDNF levels and that AEA high levels during recovery might delay the return of BDNF to basal levels. AEA production during exercise might be triggered by cortisol since we found positive correlations between these two compounds and because corticosteroids are known to stimulate endocannabinoid biosynthesis. These findings provide evidence in humans that acute exercise represents a physiological stressor able to increase peripheral levels of AEA and that BDNF might be a mechanism by which AEA influences the neuroplastic and antidepressant effects of exercise.

Wave analysis of Airy beams

The Airy beams are analyzed in order to provide a cogent physical explanation to their intriguing features which include weak diffraction, curved propagation trajectories in free-space, and self healing. The asymptotically exact analysis utilizes the method of uniform geometrical optics (UGO), and it is also verified via a uniform asymptotic evaluation of the Kirchhoff-Huygens integral. Both formulations are shown to fully agree with the exact Airy beam solution in the paraxial zone where the latter is valid, but they are also valid outside this zone. Specifically it is shown that the beam along the curved propagation trajectory is not generated by contributions from the main lobe in the aperture, i.e., it is not described by a local wave-dynamics along this trajectory. Actually, this beam is identified as a caustic of rays that emerge sideways from points in the initial aperture that are located far away from the main lobe. The field of these focusing rays, described h e by the UGO, fully agrees with the Airy beam solution. These observations explain that the "weak-diffraction" and the "self healing" properties are generated, in fact, by a continuum of sideways contributions to the field, and not by local self-curving dynamics. The uniform ray representation provides a systematic framework to synthesize aperture sources for other beam solutions with similar properties in uniform or in non-uniform media.

The stethoscope as a vector of infectious diseases in the paediatric division

AIM

Nosocomial infections are of great concern in hospital settings, and even more so in the paediatric ward. Health professionals and their medical equipment have long been known to act as vectors of infectious diseases. This study aimed at evaluating the presence of bacterial pathogens on the stethoscopes of medical personnel in the paediatric division.

METHODS

Forty-three stethoscopes belonging to senior physicians, residents, interns and medical students at the paediatric ward were sampled. Bacterial cultures and antibiotic sensitivity testing were carried out.

RESULTS

All but six bacterial cultures were positive (85.7%). Staphylococcal species were the most common contaminants (47.5%). One case of methicillin-resistant Staphylococcus aureus was encountered. Gram-negative organisms were isolated in nine different samples (21%) including one case of Acinetobacter baumannii in the neonatal intensive care unit.

CONCLUSION

Most stethoscopes harbour potential pathogens. The isolation of Gram-negative organisms pose a real risk of spreading potentially serious infections, especially in the setting of intensive care departments. Apparently, the current recommendations of regular disinfection of stethoscopes are not carried out by health personnel that participated in the study.

Ergonomics for children: an educational program for elementary school

Studies indicate that musculoskeletal discomfort and back pain problems are evident not only in adults, but also in children [11,13]. We believe that educating towards a balanced-posture, body-function and movement patterns, as well as their ergonomic implications, can minimize and even prevent these problems. Such an ergonomics awareness educational program has to start at childhood and should be an integral part of the curriculum in the schools. This article presents the educational program "Ergonomics, Movement and Posture" (EMP), which is taught in elementary schools by Physical Education (PE) students of the Kibbutzim College of Education in Israel, as part of their practicum. Although there has been no formal evaluation of the effectiveness of the program, so far, participating children, their parents, the teachers and the principles have offered positive feedback.

Accuracy of physical working capacity 170 to estimate aerobic fitness in prepubertal diabetic boys and in 2 insulin dose conditions

AIM

Exercise tests evaluate the effects of physical activity, which is one of the four recommendations for diabetes treatment. An adjusted and accurate measure of aerobic capacity in diabetic patients is thus needed. This study compared two estimates of aerobic fitness (maximal oxygen uptake vs physical working activity PWC170, i.e., the workload at a pulse of 170) and the usual versus a reduced insulin dose in preadolescent boys with type 1 diabetes mellitus.

METHODS

Sixteen prepubertal type 1 diabetic boys performed a submaximal test, the PWC(170). Gas exchange values and capillary blood glucose levels were monitored and, when possible, the test was extended to exhaustion. In 7 boys, the test was performed twice on separate days. On one day they received their usual insulin dose and on the other, their short-acting insulin was reduced by 1/3; the two tests were held in random order. The 9 other children were tested only once after receiving their usual insulin dose.

RESULTS

For the 16 boys who performed the test with the usual insulin dose, PWC(170) (W) and peak oxygen uptake (peak VO(2)) (L.min(-1)) correlated closely (r=0.81, P=0.002). Aerobic fitness did not change with insulin dose, but some hypoglycemic episodes occurred when insulin dose was not reduced.

CONCLUSIONS

Since maximal effort does not add more information, routine use of the submaximal peak VO(2)-correlated test, the PWC(170), seems sufficient, possibly in association with a planned insulin dose reduction. This dose change does not interfere with performance, but could reduce the risk of hypoglycemia.

Paroxetine Use Throughout Pregnancy: Does It Pose Any Risk to the Neonate?

A newborn of a SSRI-treated mother presented with lethargy, no crying, and no response to tactile stimulation. EEG findings were abnormal. Laboratory and clinical evaluations were normal. He recovered at the age of two weeks. Serotonin is a neurotransmitter that has an important roll in pain modulation during fetal neurodevelopment. We suspect these symptoms are attributed to the intrauterine exposure to paroxetine, through modulation of pain signals.

Copper and zinc blood levels among children with nonorganic failure to thrive

BACKGROUND AND AIMS

Copper and zinc deficiency are commonly reported among children with organic failure to thrive. In contrast, reports on copper and zinc status in children with non-organic failure to thrive are scarce. The goal of this study was to evaluate copper and zinc blood levels and nutritional intake among children with non-organic failure to thrive.

METHODS

A study group of 32 children with non-organic failure to thrive were investigated and compared with 32 healthy controls. Each child had copper and zinc blood level measurements. In addition, the study group underwent evaluation of thyroid function, immunoglobulins, endomesial antibodies and xylose test. A dietary questionnaire that included a diet history and a 24-h dietary recall was administered to parents by a dietician. Weight for height, height for age and mean daily intake of calories, protein, copper and zinc were calculated.

RESULTS

There were no significant differences between the two groups in either socioeconomic status or caloric, copper or zinc intake. Protein intake was significantly lower in the study group (P<0.0001). Plasma copper levels were within the normal range in both groups (P=0.3). Zinc plasma levels were significantly higher in the study group as compared to controls (P=0.03); however, they remained within the normal range in both groups.

CONCLUSIONS

Children with non-organic failure to thrive can maintain plasma copper and zinc levels within normal range and similar to normal controls.

Wave propagation in media having negative permittivity and permeability

Wave propagation in a double negative (DNG) medium, i.e., a medium having negative permittivity and negative permeability, is studied both analytically and numerically. The choices of the square root that leads to the index of refraction and the wave impedance in a DNG medium are determined by imposing analyticity in the complex frequency domain, and the corresponding wave properties associated with each choice are presented. These monochromatic concepts are then tested critically via a one-dimensional finite difference time domain (FDTD) simulation of the propagation of a causal, pulsed plane wave in a matched, lossy Drude model DNG medium. The causal responses of different spectral regimes of the medium with positive or negative refractive indices are studied by varying the carrier frequency of narrowband pulse excitations. The smooth transition of the phenomena associated with a DNG medium from its early-time nondispersive behavior to its late-time monochromatic response is explored with wideband pulse excitations. These FDTD results show conclusively that the square root choice leading to a negative index of refraction and positive wave impedance is the correct one, and that this choice is consistent with the overall causality of the response. An analytical, exact frequency domain solution to the scattering of a wave from a DNG slab is also given and is used to characterize several physical effects. This solution is independent of the choice of the square roots for the index of refraction and the wave impedance, and thus avoids any controversy that may arise in connection with the signs of these constituents. The DNG slab solution is used to critically examine the perfect lens concept suggested recently by Pendry. It is shown that the perfect lens effect exists only under the special case of a DNG medium with epsilon(omega)=mu(omega)=-1 that is both lossless and nondispersive. Otherwise, the closed form solutions for the field structure reveal that the DNG slab converts an incident spherical wave into a localized beam field whose parameters depend on the values of epsilon and mu. This beam field is characterized with a paraxial approximation of the exact DNG slab solution. These monochromatic concepts are again explored numerically via a causal two-dimensional FDTD simulation of the scattering of a pulsed cylindrical wave by a matched, lossy Drude model DNG slab. These FDTD results demonstrate conclusively that the monochromatic electromagnetic power flow through the DNG slab is channeled into beams rather then being focused and, hence, the Pendry perfect lens effect is not realizable with any realistic metamaterial.

Gaussian beam and pulsed-beam dynamics: complex-source and complex-spectrum formulations within and beyond paraxial asymptotics

Paraxial Gaussian beams (GB's) are collimated wave objects that have found wide application in optical system analysis and design. A GB propagates in physical space according to well-established quasi-geometric-optical rules that can accommodate weakly inhomogeneous media as well as reflection from and transmission through curved interfaces and thin-lens configurations. We examine the GB concept from a broad perspective in the frequency domain (FD) and the short-pulse time domain (TD) and within as well as arbitrarily beyond the paraxial constraint. For the formal analysis, which is followed by physics-matched high-frequency asymptotics, we use a (space-time)-(wavenumber-frequency) phase-space format to discuss the exact complex-source-point method and the associated asymptotic beam tracking by means of complex rays, the TD pulsed-beam (PB) ultrawideband wave-packet counterpart of the FD GB, GB's and PB's as basis functions for representing arbitrary fields, GB and PB diffraction, and FD-TD radiation from extended continuous aperture distributions in which the GB and the PB bases, installed through windowed transforms, yield numerically compact physics-matched a priori localization in the plane-wave-based nonwindowed spectral representations.

Asymmetric crying facies and associated congenital anomalies: prospective study and review of the literature

Congenital asymmetric crying facies, a minor congenital anomaly due to absence or hypoplasia of the depressor anguli oris muscle on one side of the mouth, is associated at times with major congenital anomalies, most commonly in the cardiovascular system. In a prospective study of 5532 infants born at the Assaf Harofeh Medical Center, Israel, during 12 months (January to December 1998), 17 infants (an incidence of 0.31%) had asymmetric crying facies. One of the affected infants had ventricular septal defect and another infant had VATER (vertebral defects, imperforate anus, tracheoesophageal fistula, and radial and renal dysplasia) syndrome. No noxious obstetric perinatal factors could be identified. Family history was unremarkable in all cases. Diagnostic work-up performed in all of the affected infants failed to reveal an additional congenital malformation. Asymmetric crying facies is a minor isolated finding in most of the cases; however, a thorough search for other congenital malformations, especially of the cardiovascular system, should be performed.

Physical source realization of complex source pulsed beams

Complex source pulsed beams (CSPB) are exact wave-packet solutions of the time-dependent wave equation that are modeled mathematically in terms of radiation from a pulsed point source located at a complex space-time coordinate. In the present paper, the physical source realization of the CSPB is explored. This is done in the framework of the acoustic field, as a concrete physical example, but a similar analysis can be applied for electromagnetic CSPB. The physical realization of the CSPB is addressed by deriving exact expressions for the acoustic source distribution in the real coordinate space that generates the CSPB, and by exploring the power and energy flux near these sources. The exact source distribution is of finite support. Special emphasis is placed on deriving simplified source functions and parametrization for the special case where the CSPB are well collimated.

Estimation of object location from wideband scattering data

We present a time domain algorithm for computation of the maximum likelihood estimate of the location of a known scattering object from wide-band scattering data acquired in a suite of scattering experiments. The algorithm consists of a three-step procedure: (1) data filtering, (2) time-domain backpropagation, and (3) coherent summation and is implemented via a number of forward and inverse Radon transforms integrated into a tomographic scheme. A computer simulation is included for illustration purposes.

Intussusception: a 9-year survey (1986-1995)

BACKGROUND

Acute intussusception has different clinical features in various parts of the world. The goal of this study was to determine the clinical presentation in different ethnic groups in Israel.

METHODS

A retrospective chart review of a 9-year period (1985-1995) was carried out at a university medical center. Data extracted included age, sex, ethnic origin, presenting symptoms and signs, the type of enema (barium or air), and the success rate of non-surgical reduction of the intussusception.

RESULTS

Ninety patients suffering from intestinal obstruction due to acute intussusception were admitted. The triad of intermittent screaming attacks, lethargy, and vomiting was observed in 37.5% of study subjects. The majority of patients were admitted during the warmer months of the year. The average age of the patients was 7.8 +/- 3.7 months; 70% of them were between the ages of 4 and 9 months and 92.5% under 1 year of age. The female-to-male ratio was 1:2.1. Air enema was superior to the barium enema in achieving reduction (p < 0.01). The incidence in the Jewish population was similar to that observed in other surveys, and twice that found in the Arab population in our region (p < 0.05).

CONCLUSIONS

The overall clinical presentation of acute intussusception found in our study does not differ from other studies. The lower incidence of acute intussusception found in the Arab population can be explained by ethnic, genetic, or nutritional factors.

The effect of aminophylline on the excursions of the diaphragm in preterm neonates. A randomized double-blind controlled study

Aminophylline is used to treat apnoea and to facilitate weaning from assisted ventilation in preterm infants. Aminophylline is thought to increase respiratory drive centrally. We performed a randomized controlled double-blind study to determine if aminophylline increases the excursions of the diaphragm indicating a possible direct peripheral effect. Twenty-two neonates were randomized to treatment with intravenous aminophylline (n = 11) or to no treatment (n = 11). An ultrasonographer, who was blinded to the group assignment, studied the diaphragmatic excursions using a real time sector scanner. The posterior one-third of the right hemidiaphragm was localized and M-mode was used to record the diaphragmatic excursions on paper. The neonates were studied in an awake but quiet state. Aminophylline resulted in an increase (43%) in the excursions of the diaphragm (p = 0.012) with no change in respiratory rate or pCO2. These findings indicate that aminophylline had a measurable effect on the diaphragmatic motion. Further studies combining this technique with other techniques are needed to determine if the main effect of aminophylline in the prevention of apnoea is mainly central or peripheral.

Is the hospital setting the place for teaching breast self-examination?

The purpose of this study was to investigate the effects of an instructional program for nurses educating them to teach breast self-examination (BSE) to hospitalized patients. Nurses' knowledge, attitudes, self-practice, and practice of teaching breast self-examination to patients were measured in a group who attended such a program and compared with those of a control group who did not attend. The researchers found that the instructional program increased nurses' teaching of BSE to their patients, but did not affect their own self-practice. Nurses' attitudes to teaching BSE were less favorable than for self-practice. Issues related to environments for teaching BSE are discussed.

The outcome of triplet, quadruplet, and quintuplet pregnancies managed in a perinatal unit: obstetric, neonatal, and follow-up data

Multifetal gestation is associated with increased frequency of maternal complications and higher perinatal morbidity and mortality. The need for contemporary data on the outcome of multifetal gestations is further underscored when selective reduction is considered. The present study details the obstetric management, neonatal outcome, and follow-up data of 24 triplet, five quadruplet, and one quintuplet pregnancies delivered in a perinatal center. The early neonatal mortality rate was 31.6, the late neonatal mortality rate was 21, and the perinatal mortality rate was 51.5. Survival to discharge was 93%. The incidence of respiratory distress syndrome was 43%, bronchopulmonary dysplasia 6%, retinopathy of prematurity 3%, intraventricular hemorrhage 4%, and cerebral palsy 2%. Follow-up from 1 to 10 years shows that only one child is moderately handicapped, whereas 99% have no significant medical problem. Early diagnosis by ultrasonography, meticulous antenatal care, early hospitalization, delivery by cesarean section, and on-site availability of a neonatologist for each baby at the time of delivery are the probable major determinants of improved outcome.

The outcome of triplet gestations complicated by fetal death

Intrauterine death in twin pregnancies has been reported to be associated with a very high incidence of morbidity and mortality in the surviving co-twin, mostly attributed to vascular disruption when vascular anastomosis exists between the twins' circulations. The present study describes the obstetric, neonatal, and follow-up data of five triplet gestations complicated by intrauterine death of one or two fetuses, compared with a control group of triplets matched for gestational age. Delivery occurred an average of 30 +/- 26 days after the diagnosis of intrauterine fetal death. Four of the five placentas were monochorionic. All nine infants survived, but four were small for gestational age (SGA). A comparison of study cases and controls revealed that monochorionic placentation was found only in the study group, that SGA infants were more likely (but not significantly so) to be in the study group, and that study infants required significantly less ventilatory support. Although the only case of long-term morbidity was in the study group, the cause of this complication was consistent with prematurity.

Elevated serum creatine kinase. Following febrile seizures

Serum creatine kinase (CK) was determined in 52 children admitted following an episode of febrile convulsions. Enzyme levels correlated with the estimated duration of the seizure. Twenty-four hour values were significantly higher than those observed 1 hour after the convulsive episode. Serum CK levels are frequently used for diagnostic purposes, so the questionable validity of this test when drawn after a convulsive episode must be considered.

Acute subdural hemorrhage: uncommon complication of vacuum extraction delivery

We report a term newborn who was delivered by vacuum extraction and subsequently developed signs of intracranial hemorrhage and in whom subdural hemorrhage was rapidly diagnosed and successfully removed.

Partial arthroscopic meniscectomy versus total open meniscectomy

One hundred sixteen patients who had undergone partial arthroscopic meniscectomy were reviewed in a short-term follow-up study (mean follow-up: 16 months). Their results were compared with those of a group of 402 patients who had been treated previously by conventional open meniscectomy in the same hospital. Average age in the arthroscopic group was 40 years, in the open group 34. Average sick leave was 4 weeks in the arthroscopic group, 10 weeks in the arthrotomy group. In the endoscopic group, there was virtually no sick leave for self-employed people, but 7 weeks if the lesion was sustained at work. Top-class sportsmen resumed competition 5 weeks after arthroscopy, 8 weeks after conventional meniscectomy. Still, most of them complained of prolonged synovial reaction resulting in a period of poor physical condition and performance. Of the patients treated by arthroscopy, 7.5% presented minor problems related to the approach (anteromedial-transpatellar), while 21.5% had similar problems after routine anteromedial incision in the open meniscectomy group. The overall results after arthroscopy were excellent in 49 cases (41.5%), good in 51 (43%), fair in 14 (12%), and poor in four (3.5%). These short-term results are comparable to those of the open meniscectomy group. The short-term results in the older patients confirm our belief that (partial) meniscectomy is useful for the older patient with a history of mechanical meniscal problems, with or without cartilage degeneration, provided one is not dealing with frank osteoarthrosis and secondary varus or valgus deformity.(ABSTRACT TRUNCATED AT 250 WORDS)

A quaternary anti-cholinesterase probe for determining the integrity of the blood--brain barrier

7-(Methylethoxyphosphinyloxy)-1-methyl quinolinium iodide (MEPQ), a new quaternary anti-cholinesterase (anti-ChE) compound was prepared and evaluated as a potential probe for assessing changes in the blood-brain barrier (B-BB) permeability. MEPQ was found to be 170 times more potent in its cholinesterase inhibitory activity than phospholine iodide, a previously reported anti-ChE probe in B-BB research. In rats and mice with impaired B-BB induced by osmotic opening, MEPQ readily penetrated through the damaged site as demonstrated by considerable reduction of ChE activity. In controls, brain ChE activity remained unaffected. It is suggested that MEPQ is a useful probe for both qualitative (histological staining) and quantitative (brain homogenated) assessment of permeability changes in the B-BB.

Infantile lethal neuraminidase deficiency (sialidosis)

An infant suffering from failure to thrive, hepatosplenomegaly, developmental retardation and early infantile death is described. The proposita demonstrated a type 2 early infantile sialidosis with onset at birth, and death at 4 months. A culture of the proband's fibroblasts showed neuraminidase deficiency, and low activity of the enzyme was found in the lymphocytes of both parents. A previous female child, born prematurely, died 6 h after birth and had hepatosplenomegaly and foam cells in the placenta. There is strong evidence that the inheritance of the disease is autosomal recessive.