[Exotic snake bites in Switzerland]. / Morsures de serpents exotiques en Suisse.

Exotic snake bites are not rare in Switzerland. Treatment can be challenging for medical staff particularly as rapid and focused management are critical to improve patient outcome. The case of a young herpetologist bitten by an exotic venomous snake is used to review measures to be taken before arrival at the emergency department and to highlight key points of management. Resources for the obtention of expert advice and antivenoms are also reported.

Dynamics of Trion formation in InxGa1-xAs quantum wells.

We show a double path mechanism for the formation of charged excitons (trions); they are formed through bi- and trimolecular processes. This directly implies that both negatively and positively charged excitons coexist in a quantum well, even in the absence of excess carriers. The model is substantiated by time-resolved photoluminescence experiments performed on a very high quality InxGa1-xAs quantum well sample, in which the photoluminescence contributions at the energy of the trion and exciton and at the band edge can be clearly separated and traced over a broad range of times and densities. The unresolved discrepancy between the theoretical and experimental radiative decay time of the exciton in a doped semiconductor quantum well is explained by the same model.

Determination of the exciton formation in quantum wells from time-resolved interband luminescence.

We present the results of a detailed time-resolved luminescence study carried out on a very high quality InGaAs quantum well sample where the contributions at the energy of the exciton and at the band edge can be clearly separated. We perform this experiment with a spectral resolution and a sensitivity of the setup, allowing us to keep the observation of these two separate contributions over a broad range of times and densities. This allows us to directly evidence the exciton formation time, which depends on the density as expected from theory. We also denote the dominant contribution of excitons to the luminescence signal, and the lack of thermodynamical equilibrium at low densities.

The Tourette's Disorder Scale (TODS): development, reliability, and validity.

To address the lack of a simple and standardized instrument to assess overall illness severity of Tourette's disorder (TD), the authors developed and tested a 15-item scale to measure a broad range of common symptoms including tics, inattention, hyperactivity, obsessions, compulsions, aggression, and emotional symptoms. Independent investigators used the 15-item Tourette's Disorder Scale (TODS) to assess 60 TD patients who were taking part in a double-blind placebo-controlled multicenter 8-week treatment study. Interrater reliability, internal consistency, convergent and discriminant validity, and sensitivity to change were examined. The TODS was associated with good interrater reliability, excellent internal consistency, and favorable levels of validity and sensitivity to change. Individual TODS items showed good convergent and discriminant validity against other measures. The TODS is a simple, efficient way for clinicians and parents to rate the severity of multiple symptoms commonly found in patients with Tourette's disorder.

A pilot controlled trial of transdermal nicotine in the treatment of attention deficit hyperactivity disorder.

OBJECTIVE: To test the hypothesis that transdermal nicotine would be efficacious for the treatment of children and adolescents with attention deficit hyperactivity disorder (ADHD). METHOD: This was a double-blind, placebo-controlled, randomized, pilot trial that compared the effects of daily transdermal nicotine (5 mg/16 hrs) to placebo in children and adolescents with ADHD. There was a three-day washout period of all psychotropic medication followed by a one-week treatment period. RESULTS: All 10 subjects enrolled (six males, four females; mean age = 10 years, SEM = 0.8) completed the study. As assessed by the 48-item Conners Parent Rating Scale at endpoint and during the trial, there was a significantly greater reduction in ADHD symptoms on "Learning Problems" and "Hyperactivity" subfactors. Nausea, stomach ache, itching under patch and dizziness were the most frequently reported adverse effects associated with transdermal nicotine. CONCLUSIONS: While the results of this study support previous research indicating that nicotinic receptor modulation may be a potentially useful strategy for the treatment of ADHD, therapeutic uses of nicotine are limited due to side effects. Thus, future research should investigate ways of improving the therapeutic index of nicotinic ligands in the treatment of ADHD, such as testing selective nicotinic antagonists alone or in combination with cholinergic agonists.

Appropriateness of indications for surgery of lumbar disc hernia and spinal stenosis.

STUDY DESIGN: This prospective study examines the appropriateness of indications for surgery of herniated intervertebral disc and spinal stenosis in patients undergoing surgery in a university hospital setting. OBJECTIVE: To evaluate the appropriateness of surgery using explicit criteria developed by an expert panel in the United States. SUMMARY OF BACKGROUND DATA: The use of surgery for herniated intervertebral disc and spinal stenosis varies widely within and among countries. It has been postulated that the main reason for treatment failure is poor selection of candidates for the procedure. METHODS: The authors prospectively evaluated appropriateness of surgical indications for herniated lumbar intervertebral disc or spinal stenosis in 328 consecutive patients undergoing the operation in two university neurosurgery departments. Outcome was measured 1 year after surgery by a standardized interview. RESULTS: Indications for surgery were considered to be appropriate or equivocal in 202 (62%) patients and inappropriate in 126 (38%). Among the 126 inappropriate procedures, 66 were so rated because of insufficient activity restriction before the procedure. One year after surgery, 74% of the patients perceived the results of the operation as good or very good. CONCLUSIONS: Appropriateness as measured by the criteria established by the American panel identified a large percentage of day-to-day practice in the two surgical units as inappropriate. However, use of criteria that include new findings about lack of efficacy of bed rest probably would lower this percentage. Criteria of appropriateness of medical and surgical procedures, developed through the panel process, need to be updated regularly.

[Pituitary adenoma secreting prolactin. Results of their surgical treatment]. / Les adénomes hypophysaires sécrétant de la prolactine. Les résultats de leur traitement chirurgical.

A retrospective study of 75 patients operated for pituitary prolactin-secreting adenomas between 1972 and 1992 is presented. 57 were women, 18 males. The major symptom was amenorrhea for women and impotence for men. Prolactinemia is correlated to the size of adenoma and thus permits a prediction of surgical results. Most of the patients with a prolactinemia under 300 ng/ml were cured by surgery alone. Surgical treatment alone at the-term follow-up cure 87% of the micro-adenomas, 17% of the enclosed adenomas, and none of the invasive adenomas. In this study there is only 7% of true recurrence. According to the high cure rate and low frequency recurrence after transphenoidal surgery for micro-adenomas we suggest this approach as the first choice treatment. On the other hand the best treatment for macro-prolactinomas is medicamentous.

Head injuries in children: a chronicle of a quarter of a century.

Children aged 0-15 years hospitalized in Geneva for head trauma during the last quarter of a century are reviewed. More than half of the severely injured children were not from Geneva area. New methods of management have been introduced progressively. The cases are divided in four successive time periods and classified according to their pathology. A continuous improvement in mortality is obvious, decreasing from 29.4% to 2.2%, but climbing again to 15.2% in the last period, probably due to more severe pathologies. For the Geneva area the mortality decreased progressively from 10.4/100,000 to 3.5/100,000 annually, due to better organization and management, but also to a drop in the incidence of severe cases from 35.5-13.5/100,000 per year. A decrease in the number of traffic accidents is responsible for this. However, the number of handicapped children has not changed.

Paediatric head trauma: influence of age and sex. I. Epidemiology.

A consecutive unselected series of 1812 children (up to 15 years old) admitted for head injuries over a period of 8.5 years was studied. The cases were divided up according to five categories of pathology: benign injury, extradural haematoma, subdural haematoma, open brain laceration and brain contusion in a broad sense. All cases of benign injury were from the Geneva area (57000 children) and 52% of the cases of severe injury were referred from other places. To these 1812 cases were added those of 23 children who died before admission recorded by the police. In the Geneva area the mortality was 6.8/100,000 per year. Patients were divided into three age groups: I (0-3 years), II (3-9 years), and III (9-15 years); group I was further subdivided into subgroups I a (0-1 year) and I b (1-3 years). The incidence of each type of accident was calculated for each age group, separately for girls and boys. Each type of pathology was correlated, sex by sex and for different ages, with the type of accident. Overall, two boys were injured for each girl. Road accidents were responsible for 15% of head injuries in group I girls, 17% in group I boys, 43% in group II girls, 45% in group II boys, 50% in group III boys and 61% in group III girls. They were responsible for 94% of all deaths and 85% of deaths of hospitalized patients. Falling was the most frequent cause of injury. Benign injuries were more frequent in group I. Only 1 of 25 patients with extradural haematomas died, and there were only 8 patients with subdural haematomas, 4 in subgroup I a (babies aged less than 1 year).

Paediatric head trauma: influence of age and sex. II. Biomechanical and anatomo-clinical correlations.

A consecutive, unselected series of 1812 cases of head trauma in children less than 15 years of age and admitted hospital over a period of 8.5 years was studied. Data concerning the grade of energy involved, the ages of the victims, the types of pathologies caused and the clinical features noted were collected and statistically analysed. Babies and toddlers (0-3 years) were shown to sustain rather low-energy trauma and suffer more skull fractures, more subdural haematomas and more benign injuries. They lost consciousness less frequently and were less frequently in coma than the other children. By contrast, they had more frequent signs of lateralization, and early seizures were much more frequent in babies than in other children. Young children (3-9 years) had rather higher-energy accidents, frequently lost consciousness, were more frequently in coma and have more frequently had a free interval associated with the development of brain swelling. They did not suffer subdural effusion or contrecoup lesions. Schoolchildren (9-15 years) were statistically more or less like young adults: the clinical sequences of trauma were more severe than in the other children, mortality was a little bit higher, the risk of extradural haematoma was higher, and they rarely suffered subdural haematomas or contrecoup lesions. Traffic accidents, with higher energy involved, were more severe.

[Computer alert and quality of care: application to the surveillance of hospital infections]. / Alertes informatiques et qualité des soins: application à la surveillance des infections hospitalières.

The Centre Informatique of Geneva University Hospital is developing, in the environment of its hospital information system, DIOGENE, a computerized alert system for surveillance of hospital infections. This hospital information system is based on an open distributed architecture and a relational database system, and covers many medical applications. This environment allows the development of alerts useful for detecting patients at risk. The alerts offer to clinicians a mean to control their efficacy in patient care. They are a new application of telematics for surveillance in clinical epidemiology, and are a tool for quality assurance. Two examples of alerts established for hospital infection control activities are presented. The first alert systematically detects all cases of patients colonized by or infected with methicillin-resistant Staphylococcus aureus (MRSA). The second alert helps to organize prospective surveillance of bloodstream infections in order to identify some risk factors for infection and propose preventive measures.

Chronic subdural haematomas. Results of a closed drainage method in adults.

This paper concerns 106 consecutive subdural haematomas in adults, 94 of whom were chronic and 12 subacute. Among these, 78 subdural haematomas were operated upon according to a new protocol--two burr holes, irrigation and closed drainage of the haematoma for 48 hours in the supine position. The others were treated by decompressive craniectomy according to the clinical judgement of the surgeon. The results are presented.

Effects of DNA topoisomerase II inhibitors on human bone marrow progenitor cells.

Topoisomerase II (topo II) is a target for many cytotoxic agents. Two observations, however, warrant caution in their therapeutic use: first, these agents can inhibit differentiation and second, perturbations in function render the enzyme error-prone. Illegitimate recombination events occurring at sites where topo II acts in differentiation could be particularly important in the development of secondary malignancies (relatively frequent after therapy with agents that target topo II). Topo II inhibitors are heterogeneous in mechanisms of action; in site-specificity of cleavable complex 'entrapment' (where present) and in the relative potency against the two topo II isoforms, all potentially influencing the site of maximum DNA damage. The object of this study was to examine the effect of topo II inhibitors on human haemopoietic precursor cells, to determine which have most impact on differentiation. We selected two which act via cleavable complex entrapment, but with different site preferences (m-AMSA and VP-16), and two acting via other mechanisms (merbarone and fostriecin). VP-16 and m-AMSA showed similar patterns with low dose stimulation of granulocyte-macrophage colony formation and high dose inhibition of all colony types. The stimulation was accompanied by an increase in colony size and blast content, consistent with a low dose inhibition of differentiation. Forstriecin, in contrast, stimulated predominantly mixed and erythroid colonies. Merbarone failed to increase colony formation. Neither produced substantial inhibition of colony formation. The effects on granulocyte-macrophage progenitors were confirmed using 7-day suspension cultures, using nitroblue tetrazolium (NBT) reduction and 3-4,5,dimethylthiazol 2,5-diphenyl tetrazolium bromide (MTT) assays for differentiated cells and total cell mass, respectively. These results demonstrate that the effects of topo II inhibitors on haemopoietic cell proliferation and differentiation are agent-specific and can involve lineage-restricted partial inhibition of differentiation.

[Prevention of infections of cerebrospinal fluid shunts for hydrocephalus]. / Prévention des infections des drainages ventriculaires pour hydrocéphalie.

Two consecutive series of patients operated for insertion or revision of a shunt for hydrocephalus have been followed for at least 18 months. The series are comparable. The first series (84 cases) did not receive antibiotic prophylaxis, whereas the second series (59 cases) received a unique dose of intravenous Vancomycin immediately before the operation. In the first series (168 operations), there were 18 infections, 8 in the group of 34 children and 10 in the group of 50 adults. In the second series, only one infection happened in the group of 27 adults (41 operations) and none among the 22 children (44 operations). The difference was significative. Bacteriological samples were taken during these operations. The positive cultures, mostly for sta. epidermidis, were as frequent among the cases of the first series than among those of the second series. The antibiotics are considered effective in protecting the shunting device against contamination during the surgical procedure by germs from the skin of the patient.

[Epidemiology of narrow spinal canal]. / Epidémiologie des canaux lombaires étroits.

During a period of 4.5 years, 199 patients have been operated on by laminectomy because of narrow lumbar canal. The incidence in Geneva is about 11.5 case/100000/year and the ratio between male and female is 1.28. The disease is strongly related to aging, but men are affected earlier in their life than women. Heavy work, particularly for men, has a part to play in the genesis, like the body mass calculated by BMI (Body Mass Index). A comparison between the epidemiology of lumbar disc prolapse and lumbar stenosis shows the differences.