Infection control for the otolaryngologist in the era of severe acute respiratory syndrome

OBJECTIVES: Severe acute respiratory syndrome (SARS) has affected more than 8400 persons in 28 countries, with more than 800 deaths. The current SARS outbreak, especially in North American health care centers, has motivated a re-evaluation of infection control practices in the hospital and clinic environment. These considerations are particularly important to otolaryngology, in which examination and diagnostic procedures often bring the otolaryngologist in close--if not direct--contact with the patient's upper airway, mucosa, and secretions. The otolaryngologist is at increased risk of contracting a respiratory pathogen. METHOD: A joint effort by the Department of Otolaryngology at Queen's University and the Infection Control Services of the Hotel Dieu Hospital, Kingston, Ontario, was carried out to develop specific infection control guidelines for the otolaryngologists using strategies from the Centers for Disease Control and Prevention in the United States and the Laboratory Center for Disease Control, Health Canada. RESULTS: A set of specific recommendations was developed for the otolaryngologists to augment current infection control, including diligent use of personal protective equipment with every patient encounter. Moreover, this equipment should be removed according to specific protocol, to avoid contamination of self, others, and surroundings. Finally, a number of practice modifications are being adopted as prudent precautionary measures. CONCLUSION: It is essential to adhere to these recommendations in order to protect the health and safety of clinicians, colleagues, and patients.     

Hypothalamic hamartoma and seizures: a treatable epileptic encephalopathy

Hypothalamic hamartomas may be associated with gelastic seizures, focal seizures, and a generalized epileptic encephalopathy, with severe seizures and cognitive and behavior decline. Despite earlier views to the contrary, good evidence now exists that all these clinical features are caused, directly or indirectly, by the hamartoma. Resection of these lesions was long regarded as too hazardous and unlikely to benefit seizure control. It is now clear that hypothalamic hamartomas can be effectively treated with a variety of surgical approaches with sustained seizure control and often seizure freedom. Qualitative observations suggest that behavior and cognition also improve with treatment, but quantitative validation is required. The specific approach should be tailored according to the surgical anatomy of the lesion and the experience of the surgeon. Choices include a transcallosal approach (good for intraventricular lesions), a pterional approach (useful for interpeduncular lesions), a transventricular endoscopic approach, or destruction of the lesion with radiofrequency probes or gamma knife radiosurgery. The previously dismal outlook for children with severe seizures associated with this lesion has now dramatically changed. These insights may have implications for other epileptic encephalopathies of childhood.     

Depression in Kraepelinian schizophrenia

In order to improve our understanding of depression in chronic schizophrenia, depressive symptoms were assessed in institutionalized, so called Kraepelinian, patients with schizophrenia (N = 43). The patients had been ill and dependent on others for at least 5 years. Depressive symptoms as measured by the Hamilton Depression (HAM-D) scale were less prevalent in this population compared to published data on non-Kraepelinian patients. Only 5% of our Kraepelinian patients had a HAM-D score >/= 16. There was also a low prevalence of core depressive symptoms (depressed mood, suicidal ideation, and guilt). The relationship of depression to other dimensions of schizophrenia was explored. Depression had a modest positive correlation (r = 0.44) with general psychopathology as measured by the Brief Psychiatric Rating Scale (BPRS), but not with positive symptoms as measured by BPRS positive subscale or negative symptoms as measured by the Scale for the Assessment of Negative Symptoms (SANS). Depression also showed a modest positive correlation (r =.48) using the Simpson-Angus Rating Scale (SAS) for extrapyramidal symptoms (EPS). These results indicate that in Kraepelinian schizophrenia, depression is not prevalent, even though patients are severely ill both in symptom and functioning domains. The results of our analysis support that Kraepelinian schizophrenia is a distinct subtype, and raise questions regarding the boundary between schizoaffective disorder and non-Kraepelinian schizophrenia. Finally, the low rate of depression observed revives the notion that preservation of core functional abilities is important for a depressive reaction to evolve in schizophrenia.     

Temporal profile of hilar basal dendrite formation on dentate granule cells after status epilepticus

Granule cells with hilar basal dendrites (HBDs) are found after status epilepticus (SE) in three rat models of temporal lobe epilepsy. These granule cells are commonly located at the hilar border and could be newly born granule cells based on their location. The aim of this study was to determine how long it takes for HBDs to form on granule cells after SE. Pilocarpine was injected to induce SE and rats were killed at different times: 3 days, 1, 2, and 3 weeks after SE. Biocytin was injected into CA3 stratum lucidum of hippocampal slices to label granule cells with HBDs. The number, morphology, and length of HBDs were analyzed at the different time points. Basal processes of granule cells from rats killed 3 days after pilocarpine injection were judged not to be HBDs because they were short in length and did not ramify in the hilus. "True" HBDs were detected as early as 7 and 8 days after pilocarpine-induced SE. Similar frequencies of granule cells with HBDs were observed at the later time points. This study shows that HBDs can form on granule cells as early as 1 week following SE. These results are consistent with the hypothesis that HBDs on granule cells may be generated from seizure-induced, de novo granule cells, however, alternative explanations that some or all HBDs arise from pre-SE generated granule cells cannot be ruled out at this time and will require further examination.     

Increased cerebral functional connectivity underlying the antinociceptive effects of hypnosis

The neural mechanisms underlying the antinociceptive effects of hypnosis are not well understood. Using positron emission tomography (PET), we recently showed that the activity in the anterior cingulate cortex (midcingulate area 24a') covaries with the hypnosis-induced reduction of affective and sensory responses to noxious thermal stimulation [Faymonville et al., Anesthesiology 92 (2000) 1257-1267]. In the present study, we assessed changes in cerebral functional connectivity related to the hypnotic state, compared to simple distraction and the resting state. Nineteen highly hypnotizable right-handed volunteers were studied using H2(15)O-PET. The experimental conditions were hot noxious or warm non-noxious stimulation of the right hand during resting state, mental imagery and hypnotic state. Using a psychophysiological interaction analysis, we identified brain areas that would respond to noxious stimulations under the modulatory action of the midcingulate cortex in, and only in, the hypnotic state. Hypnosis, compared to the resting state, reduced pain perception by 50%. Pain perception during rest and mental imagery was not significantly different. Analysis of PET data showed that the hypnotic state, compared to normal alertness (i.e., rest and mental imagery), significantly enhanced the functional modulation between midcingulate cortex and a large neural network encompassing bilateral insula, pregenual anterior cingulate cortex, pre-supplementary motor area, right prefrontal cortex and striatum, thalamus and brainstem. These findings point to a critical role for the midcingulate cortex in the modulation of a large cortical and subcortical network underlying its influence on sensory, affective, cognitive and behavioral aspects of nociception, in the specific context of hypnosis.     

Exosomes and anti-tumour immunotherapy

Exosomes are 60 to 90 nm membrane vesicles originating from late endosomes and secreted from most hematopoietic and epithelial cells in vitro. B cell derived-exosome antigenicity was first reported in 1996 in MHC class II restricted CD4+ T lymphocytes. In 1998, we reported that dendritic cell derived-exosomes are immunogenic in mice leading to tumor rejection. These findings have renewed the interest in exosomes. The current challenge consists in understanding the mechanisms and the physiological relevance of exosomes that could contribute to the design of the optimal exosome based-vaccination. Here, we will focus on the biological features pertaining to dendritic cell- and tumor cell derived-exosomes and will discuss their potential clinical implementation.     

Infection due to extended-spectrum beta-lactamase-producing Salmonella enterica subsp. enterica serotype infantis in a neonatal unit

OBJECTIVE: To describe the investigation and control of an outbreak of extended-spectrum beta-lactamase producing Salmonella enterica subsp. enterica serotype Infantis in a neonatal unit in Brazil. METHODS: A case-control study for risk factors for Salmonella Infantis systemic infection, environmental cultures, and evaluation of staffing and overcrowding and an assessment of infection control practices were performed. RESULTS: During July 1998 to June 1999, 140 Salmonella Infantis culture-positive patients were identified in the neonatal unit. Presence of a peripheral intravascular catheter was identified as an independent risk factor (odds ratio = 4.98; 95% CI = 1.59-19.31; P =.01) and each 250-g increase in birth weight as a protective factor (odds ratio = 0.76; 95% CI = 0.57-0.95; P =.03). Hospital stay was significantly longer and costs higher in case patients than in control patients. Salmonella Infantis was isolated from multiple environmental sources. Neonatal unit personnel were observed to make several breaks in infection control practices. The unit was understaffed and overcrowded. Prompt case identification, cohorting of patients, enhanced staff hand hygiene, and environmental cleaning terminated the outbreak. CONCLUSIONS: Inadequate infection control practices, nursery overcrowding, and understaffing can have an adverse effect on patient morbidity, mortality rates, and hospital cost.     

Evaluation in the design of health information systems: application of approaches emerging from usability engineering

This paper examines the role of evaluation in the design of health care information systems. A framework is presented for considering evaluation in the context of software development processes, in particular, the systems development life cycle (SDLC). Variations on standard design methodologies are then discussed, including methods based on rapid development and continual evaluation of prototype systems. Usability testing is presented as a key method for conducting evaluations during iterative system development. The emergence of design methodologies, where evaluation is viewed as a central part of the development cycle is also discussed. Evaluation methodologies are then considered along a continuum, ranging from studies involving a high degree of experimental control to observational approaches. A full cycle approach to evaluation of health care systems is argued for, involving deployment of new methods across the SDLC. Implications for future work exploring the integration of design and evaluation processes in health informatics are discussed.