Premature termination of the sympathetic chain

The sympathetic chain serves to distribute visceral efferents and afferents over the entire body. The sympathetic chain courses from the base of the skull to the coccyx and sends branches to distribute along spinal nerves and a number of visceral nerves that distribute to cardiac muscle, smooth muscle and glands. During dissection of the posterior abdominal wall, we identified a rare variation of the sympathetic chain. In this subject, the sympathetic chain failed to send grey rami to the L2-4 spinal nerves and terminated by joining the S1 anterior ramus. Such a variation has only been reported once in the literature in 1895. We provide both schematic and photographic documentation of this variation and propose a number of possible circuits whereby visceral axons can reach their target despite these anatomical barriers.

A tale of two arteries: dual posterior cerebral arteries with vascular bridges. A possible protective pattern?

Stroke is a common morbidity and a frequent cause of disability and even death. The impact of cerebrovascular events is dictated by the brain region involved and can be complicated by anatomical variations. One of the most common variations impacting the cerebral vasculature is the presence of a foetal posterior cerebral artery. This vessel arises from the internal carotid artery instead of the basilar artery and is often associated with more extensive injury in cerebrovascular events. Herein, we report the case of a 60-year-old male who had numerous arterial abnormalities, including a kink and a coil of the left internal carotid, two posterior communicating arteries on the right and two posterior cerebral arteries (PCA) on the left, one arising from the internal carotid (foetal PCA) and one from the basilar. The foetal PCA supplied the thalamus, splenium of the corpus callosum and primary visual cortex. The basilar PCA supplied the midbrain and parts of the occipital lobe. These PCA were connected to each other by a vascular bridge and the foetal PCA was connected to the middle cerebral artery by an additional vascular bridge. This vascular pattern would appear to provide collateral support around blockages in the internal carotid and main stem middle and PCA.

Artificial neural network for the classification of nanoparticles shape distributions

A new methodology, to the best of our knowledge, is developed to determine the shape distribution profile of gold nanoparticles (NPs) from optical spectroscopic measurements. Indeed, an artificial neural network (ANN) approach was introduced to classify Au NP shape distributions from their normalized absorption spectra. This ANN quantitatively analyzes the absorption spectra and provides the posterior probability to have a bimodal or unimodal shape distribution. Several colloidal suspensions were considered to investigate the robustness of the ANN approach. The comparison between ANN classification and TEM analysis was also given and discussed. We demonstrate that ANN classification is a suitable tool to inspect rapidly Au colloidal suspensions after their synthesis.

[Pleurisy induced by atorvastatin]

INTRODUCTION

Whereas numerous case reports have described statin-induced lung injuries, statin-induced pleural effusions are uncommon.

CASE REPORT

An 84-year-old man presented with bilateral pleural effusions two years after starting treatment with atorvastatin. No other cause of pleural effusion was found and all symptoms and radiological signs resolved rapidly after discontinuation of the drug. Furthermore, an accidental reintroduction of the treatment resulted in recurrence of the same clinical picture, reinforcing the hypothesis that atorvastatin was responsible for this pleural effusion.

CONCLUSION

Pleuropulmonary manifestations in a patient treated with atorvastatin should rapidly evoke an iatrogenic origin and the discontinuation of the drug should be discussed.

Periodontal response to all-ceramic crowns (IPS Empress) in general practice

OBJECTIVE

The purpose of this study was to investigate the periodontal response to the presence of all-ceramic crowns (IPS Empress) in general practice patients.

METHODS

The convenience sample included 82 IPS Empress crowns placed in 64 patients. These crowns had been in place for an average of 16.27 (SD 9.26) months and ranged from 6.2 to 48.87 months at the time of clinical examination. Periodontal health status (as determined by dental plaque, gingival health status, periodontal pockets) was assessed around all crowned teeth and around matched contralateral teeth by one calibrated examiner. Periodontal indices utilized included the Plaque Index (PI), Gingival Index (GI) and pocket depth (PD) with calibrated probes graduated in millimetres. Plaque, gingival and PD values for crowned teeth were compared with those for control teeth using Wilcoxon signed-rank test for each clinical parameters. Chi-square was used to test the significance of the difference in their distribution between crowns and control teeth.

RESULTS

Statistically, PI (0.35), GI (0.41) and mean PD scores (1.42) of IPS Empress crowned teeth compared less favourably with scores of the control teeth (0.27, 0.23 and 0.86 respectively).

CONCLUSION

Teeth with IPS Empress crowns had poorer periodontal health and more clinically evident plaque than uncrowned teeth.

Comparison of efficiency and preference of metal and plastic spacers in preschool children

BACKGROUND

The metal NebuChamber valved holding chamber (VHC) has gained wide acceptance among children with asthma. Due to its nonelectrostatic properties and larger volume, the 250-mL, metal NebuChamber delivers a greater mass of aerosol to a filter at the mouth compared with the commonly used 150-mL polypropylene AeroChamber VHC. Such in vitro results have been used to suggest that this may provide increased efficacy with the NebuChamber. No comparative efficacy data exist for preschool children with asthma.

OBJECTIVE

To compare efficiency and preference of metal and plastic spacers in preschool children.

METHODS

Children with mild-to-moderate persistent asthma received 200 microg of budesonide twice daily by NebuChamber or AeroChamber, both with the mask provided in a randomized, 2-month, crossover trial. Symptom diary cards, beta-agonist use, and preference by children and parents were compared.

RESULTS

Thirty children (mean +/- SD age, 4.3 +/- 0.3 years) completed the study. There was no difference between the AeroChamber and NebuChamber in clinical efficacy outcomes. There was no difference between the AeroChamber and NebuChamber in parents' view of ease of use, design, acceptability by the children, and overall satisfaction.

CONCLUSIONS

Despite a greater total dose delivered to the mouth, the NebuChamber appears no more effective than the AeroChamber and it is not preferred by patients or parents. More parents chose to continue to use the NebuChamber after the study.

Safety of inhaled corticosteroids delivered by plastic and metal spacers

BACKGROUND

Because of its non-electrostatic properties the metal Nebuchamber (NC) valved holding chamber (VHC) delivers a greater mass of aerosol to the mouth than the polypropylene Aerochamber (AC) VHC. Delivery of more aerosol to the lungs may also increase systemic absorption of inhaled corticosteroids (ICS) and hypothalamo-pituitary-adrenal (HPA) suppression.

METHODS

Thirty children (mean 4.3 (SD 0.3) years) received 200 micro g budesonide twice daily by NC or AC, both with the mask provided, in a randomised, two month crossover trial. Twenty four hour urinary free cortisol (UFC) was determined as a measure of HPA suppression.

RESULTS

UFC decreased from 42.3 (7.8) nmol UFC/nmol creatinine control to 26.2 (2.4) (p = 0.06 v control) after AC, and to 24.5 (2.5) (p = 0.04 v control) after NC (p = 0.4 AC v NC).

CONCLUSIONS

Despite a greater total dose delivered to the mouth, NC is not associated with greater HPA suppression when using 400 micro g/day budesonide under real life conditions in young children.

Transdermal estrogen replacement therapy decreases sympathetic activity in postmenopausal women

BACKGROUND

Menopause heralds a dramatic increase in incident hypertension, suggesting a protective effect of estrogen on blood pressure (BP). In female rats, estrogen has been shown to decrease sympathetic nerve discharge (SND) and BP. SND, however, has not been recorded during estrogen replacement therapy (ERT) in humans. Methods and Results-In 12 normotensive postmenopausal women, we conducted a randomized crossover placebo-controlled study to test whether chronic ERT caused a sustained decrease in SND and BP. Twenty-four-hour ambulatory BP, SND, and arterial baroreflex sensitivity were measured before and after 8 weeks of transdermal estradiol (200 microgram/d), oral conjugated estrogens (0.625 mg/d), or placebo. To test the acute effects of estrogen on SND, additional studies were performed in the same women receiving intravenous conjugated estrogens or sublingual estradiol. After 8 weeks of transdermal ERT, the basal rate of SND decreased by 30% (from 40+/-4 to 27+/-4 bursts per minute, P=0.0001) and ambulatory diastolic BP fell by 5+/-2 mm Hg (P=0.0003). In contrast, SND and BP were unaffected either by 8 weeks of oral ERT or by acute estrogen administration. Neither transdermal nor oral ERT had any effects on baroreflex sensitivity.

CONCLUSIONS

In normotensive postmenopausal women, chronic transdermal ERT decreases SND without augmenting arterial baroreflexes and causes a small but statistically significant decrease in ambulatory BP. Sympathetic inhibition is evident only with chronic rather than acute estrogen administration, implying a genomic mechanism of action. Because the effects of transdermal ERT are larger than those of oral ERT, the route of administration may be an important consideration in optimizing the beneficial effects of ERT on BP and overall cardiovascular health.

Sleep position, bedding and heating practices in high- and low-risk ethnic groups for unexpected death in infancy (UDI)

In a previous study, a significant increased risk for unexpected death in infancy (UDI) among Arab infants as compared to Jews (RR: 5.2) was found. The incidence has significantly decreased in both groups during the 'back to sleep' campaign. The objective of this study was to compare the prevalence of three risk factors, i.e. positioning, night dressing/covering and heating practices in these ethnic groups. A community sampling procedure was employed, resulting in the participation of 264 Jewish and 146 Arab mothers of infants between 1 and 4 months, born at term and with no chronic illness at the time of the study. A questionnaire in Arabic and Hebrew was designed, pertaining to sleep positioning at the time of the study and of the previous infant, prior to the SIDS prevention campaign, as well as clothing and heating practices. Significantly, more Arab infants were put to sleep in a supine or side position as compared to Jewish infants both during the study (p = 0.002) as well as prior to the SIDS campaign (p = 0.001). No ethnic difference was related to clothing practices. Open heating, however, was significantly more common in the Arab sector (p = 0.001). A logistic procedure for each of the practices indicated that ethnicity is related significantly to both sleep position (p = 0.002) and beating practices (p = 0.001). Prone sleep positioning was still prevalent (32.2%) more so among Jews (35.2%) than Arabs (27%).

CONCLUSION

Sleep positioning and overdressing do not appear to be the major attributable risk factors for UDI among Arab infants as compared to Jews. The compliance with positioning recommendations is lower than expected in both ethnic groups.

Cocaine stimulates the human cardiovascular system via a central mechanism of action

BACKGROUND

Cocaine is thought to stimulate the cardiovascular system by blocking peripheral norepinephrine reuptake. This study was designed to test the novel hypotheses that cocaine also stimulates the human cardiovascular system by (1) increasing central sympathetic outflow, or (2) decreasing parasympathetic control of heart rate.

METHODS AND RESULTS

In 14 healthy cocaine-naive humans, we measured blood pressure, heart rate, and skin sympathetic nerve activity (SNA) with intraneural microelectrodes before, during, and for 90 minutes after intranasal cocaine (2 mg/kg, n=7) or lidocaine (2 mg/kg, n=7). Intranasal cocaine caused an initial but transient 3. 3-fold increase in skin SNA during the period of intranasal administration followed by a sustained 2.4-fold increase lasting for up to 90 minutes after cocaine. Unlike cocaine, intranasal lidocaine caused only a small transient increase in skin SNA due to local nasal irritation. The cocaine-induced increase in SNA was accompanied by decreased skin blood flow, increased skin vascular resistance, and increased heart rate. In 11 additional subjects, we showed that the cocaine-induced increase in heart rate was eliminated by beta-adrenergic receptor blockade (propranolol) but unaffected by muscarinic receptor blockade (atropine), indicating sympathetic mediation.

CONCLUSIONS

These studies provide direct microneurographic evidence in humans that intranasal cocaine stimulates central sympathetic outflow. This central sympathetic activation appears to be targeted not only to the cutaneous circulation promoting peripheral vasoconstriction but also to the heart promoting tachycardia.

Effectiveness and safety of inhaled corticosteroids in controlling acute asthma attacks in children who were treated in the emergency department: a controlled comparative study with oral prednisolone

BACKGROUND

Inhaled corticosteroids have a greater antiinflammatory potency and fewer systemic effects than intravenous, intramuscular, or oral corticosteroids. However, their role in acute asthma has not been established. We prospectively investigated the efficacy and safety of inhaled corticosteroids in controlling moderately severe acute asthma attacks in children who were treated in the emergency department.

METHODS

Children who were treated in the emergency department with moderately severe asthma attacks after receiving treatment with inhaled terbutaline were allocated by double-blind design to receive 1 dose of either 1600 micro(g) budesonide turbohaler or 2 mg/kg prednisolone. The pulmonary index score and peak expiratory flow rate were measured hourly for the first 4 hours. After discharge the children were treated with the same initial doses given 4 times daily, followed by a 25% reduction in dose every second day for 1 week. Parents recorded asthma symptoms and use of beta-2 agonists on a daily diary card. Serum cortisol concentration was measured at the end of weeks 1 and 3.

RESULTS

Twenty-two children (11 in each group) with similar baseline parameters completed the study. There was a similar improvement in pulmonary index score and peak expiratory flow rate in the 2 groups. Children treated with budesonide showed an earlier clinical response than those given prednisolone, who also showed a decrease in serum cortisol concentration.

CONCLUSION

In children with moderately severe asthma attacks who were treated in the emergency department, a short-term dose schedule of inhaled budesonide turbohaler, starting with a high dose and followed by a decrease over 1 week, is at least as effective as oral prednisolone, without suppressing serum cortisol concentration.

The differences in health concerns between mothers and health care professionals in a preventive community set up

To assess the degree to which mothers, nurses and pediatricians share common concerns regarding infants' health and well-being a cross-sectional survey with stratified demographic sampling was conducted. A 12-item questionnaire pertaining to health concerns was administered to 22 mothers of infants between 1 and 18 months of age, treated at six Well Baby community clinics with 36 nurses and 25 pediatricians. Mothers and health care professionals expressed significantly different concerns. Pediatricians and nurses shared a more similar order of concerns. However, they too differed on the degree of concern related to some of the health issues, i.e. nurses perceived the issues related to feeding, behaviour, skin, sleep and daily routines as significantly more important than did pediatricians. Additional efforts should be devoted to improve and clarify communication between mothers and health care professionals.

Resolution of severe bronchiectasis after removal of long-standing retained foreign body

Saccular bronchiectasis secondary to the presence of a long retained foreign body is considered irreversible and an indication for resection of the diseased segment or lobe. We describe a 3 1/2 year-old girl with a retained organic foreign body for 18 months, and who was treated conservatively after laser resection and extraction of the inflammatory mass from the bronchus intermedius followed by complete resolution of the bronchiectasis. We suggest that even severe bronchiectasis following prolonged retention of a foreign body may be reversible after removal of the obstruction and reestablishment of airway patency.

Dynamic security contingency screening and ranking using neural networks

This paper summarizes BC Hydro's experience in applying neural networks to dynamic security contingency screening and ranking. The idea is to use the information on the prevailing operating condition and directly provide contingency screening and ranking using a trained neural network. To train the two neural networks for the large scale systems of BC Hydro and Hydro Quebec, in total 1691 detailed transient stability simulation were conducted, 1158 for BC Hydro system and 533 for the Hydro Quebec system. The simulation program was equipped with the energy margin calculation module (second kick) to measure the energy margin in each run. The first set of results showed poor performance for the neural networks in assessing the dynamic security. However a number of corrective measures improved the results significantly. These corrective measures included: 1) the effectiveness of output; 2) the number of outputs; 3) the type of features (static versus dynamic); 4) the number of features; 5) system partitioning; and 6) the ratio of training samples to features. The final results obtained using the large scale systems of BC Hydro and Hydro Quebec demonstrates a good potential for neural network in dynamic security assessment contingency screening and ranking.