Role of the nose in inspiration in mouth breathing: quantitative determination by analysis of expiratory gases

It is widely accepted that increased nasal resistance plays a major role in habitual mouth breathing. We investigated oronasal air flow distribution during voluntary mouth breathing in subjects without nasal obstruction. To determine whether nasal air flow contributes to total inspiratory flow, we administered 100% O2 by a nasal mask while the lips were kept apart by a mouth piece. Expired O2 concentrations measured at the mouth were a sensitive indicator of nasal admixture during inspiration. Theoretical considerations predict that mixed expired pO2 from two consecutive steady state periods should allow calculation of nasal admixture. Measurements made on 22 healthy volunteers revealed a very variable degree of nasal contribution to inspiratory air flow (mean +/- SD, 25 +/- 15%, range 3-70%). There was no correlation between this proportion and anthropometric data, smoking habits, nasal resistance, or presence of rhinitis. We suggest that changes in the position of the soft palate, tongue, and/or pharyngeal wall associated with respiration are mainly responsible for the within and between subject variation observed in this study. This explanation is consistent with recent experimental findings on the pharyngeal dilating muscles.     

Empiric immunization versus serologic screening: developing a cost-effective strategy for the use of hepatitis A immunization in travelers

BACKGROUND: Older individuals and those born overseas are thought at increased risk of prior exposure and thus have naturally acquired immunity to hepatitis A. Whether these individuals or other groups of international travelers should be screened for acquired immunity or empirically immunized is not clear. Hepatitis A serology and risk factor data was obtained prospectively in patients presenting for hepatitis A immunization and used to develop a cost-effective strategy for the use of serologic screening and empiric immunization in our traveler population. METHOD: Candidates for hepatitis A immunization were routinely screened for total hepatitis A serum antibody. Risk factor data including country of birth, travel history, and history of jaundice was collected. Cost-effectiveness was assessed by comparing the cost of serology to screen all patients plus cost to immunize those found to be seronegative with, the cost of empirically immunizing all patients. RESULTS: Analyses were conducted comparing age, travel history, country of birth, and history of jaundice for significance in predicting seropositivity in a group of 115 subjects. Country of birth was statistically a significant predictor of positive results with 80.0% of foreign-born patients positive for total antibody against hepatitis A compared with 35.6% of patients born in the United States. Living outside of the United States (defined as greater than 30 days) was also correlated with a higher prevalence of hepatitis A positive serology. Age was not predictive for the group as a whole. A lower prevalence (24.3%) was noted in the group of US born individuals aged 30 to 60. Travel and prior history of jaundice failed to demonstrate significance. CONCLUSIONS: Employing a simple cost-effectiveness equation using cost of serological testing, cost of vaccine, and prevalence of acquired immunity in the community, a strategy was developed. In our population it was cost-effective to screen all foreign-born individuals and those who had lived outside the United States.     

Genetics and cardiac arrhythmias

The identification of the first gene locus of hereditary arrhythmias was made over 10 years ago. In the last few years, considerable progress has been made and the number of culprit genes for cardiac arrhythmias has rapidly increased. This has been the fruit of close collaboration between clinicians, geneticists and physiologists. This work has demonstrated the heterogenous nature of genetics of diseases. It has led to a better understanding of underlying physiopathological mechanisms by the study of the relationship between gene and clinical abnormalities. In addition, analysis of phenotypes and genotypes has improved our knowledge of the clinical presentation of diseases and opened up new therapeutic approaches. These new diagnostic methods have enabled preventive measures to be taken to avoid potentially serious arrhythmias. The genetics of cardiac arrhythmias is still in its infancy: many culprit genes remain undetected and their identification should led to considerable progress in the understanding of the physiopathology of arrhythmias and their treatment.     

Disturbed sleep in children with Tourette syndrome: a polysomnographic study

OBJECTIVE: To evaluate objective data on sleep quantity/quality and motor activity during night sleep in children with Tourette syndrome (TS). METHOD: Polysomnography of 17 unmedicated TS children (ages: 7;11-15;5, mean: 11;10 years) without comorbid attention-deficit hyperactivity disorder (ADHD) was compared with 16 age-, sex- and IQ-matched healthy controls. Sleep analyses according to the procedure of Rechtschaffen and Kales were supplemented by counting epochs with short arousal-related movements (相似文献   

Percutaneous coronary intervention in the elderly: procedural success and 1-year outcomes

Clinical trials have found increased morbidity in elderly persons presenting for percutaneous coronary intervention for chronic stable angina. Long-term follow-up is limited for the elderly following percutaneous coronary intervention. The authors reviewed all coronary interventions performed from January 1998 to August 2001. One year following the procedure, subjects were screened for death, need for revascularization, and myocardial infarction. There were 401 subjects aged ≥65years (mean 73.4±6.0years) and 479 subjects aged <65years (mean 55.6±6.7 years). Although there was no difference in 1-year rate of subsequent myocardial infarction or in revascularization, the elderly were more likely to die during hospitalization (4.7% vs. 1.0%, p<0.01), and at 1 year (10.2% vs. 4.0%, p<0.01). When controlled for ejection fraction, age was no longer significant in either predischarge mortality or in 1-year mortality. Excess postpercutaneous coronary intervention mortality in the elderly may be due to underlying comorbidities and not due to subsequent myocardial infarction or revascularization.     

Input dysfunction and beyond--an evaluation of CPT components

The aim of our project is to analyze the functional meaning of neurocognitive components of the Continuous Performance Tests (CPT), which may be responsible for the well-documented performance deficit. Since the CPT can be considered as a vulnerability marker for schizophrenia, this question is of special interest. We set up a test battery testing five different cognitive processing modes: perceptual organization, selective attention, short-term memory (storing component), working memory (rehearsal component), and vigilance/sustained attention. In order to avoid the pitfall of interpreting results confounded by psychometric differences within tasks, we created psychometrically parallel versions within each experimental block (following the proposals of Chapman and Chapman [J. Nerv. Ment. Dis. 171 (1983) 658]). At the main experimental session, we tested newly admitted patients with a DSM diagnosis of schizophrenia during remission (N=30), patients with major depressive disorder (MD) (N=18), and healthy controls (N=20). Results showed that differences specific for schizophrenia are seen at the experimental block, which tests perceptual organization. However, all levels of perceptual organization performance were concerned, i.e., from processing organized to non-organized patterns. The regression analysis showed that 3-7 CPT version performances could be explained by problems with short-term memory, sustained attention, and perceptual organization. In light of these findings, we discussed whether etiology of schizophrenia could be conceptualized as a circumscribed neurocognitive deficit or a multifunctional, multilocal deficit.     

Hippocampal expression of the calcium sensor protein visinin-like protein-1 in schizophrenia

Hippocampal cytoarchitectural abnormalities may be part of the cerebral substrate of schizophrenia. Amongst the chemical components being abnormal in brains of schizophrenics are altered calcium concentrations and reduced expression of the neurotrophin receptor, trkB. We studied by immunohistochemical methods the distribution of visinin-like protein-1 (VILIP-1), which is a calcium sensor protein and at the same time a trkB mRNA binding protein, in hippocampi of nine schizophrenic patients and nine matched control subjects. In normal hippocampi VILIP-1 immunoreactivity was found in multiple pyramidal cells and interneurons. A portion of VILIP-1 immunoreactive interneurons co-express calretinin (60%) and parvalbumin (<10%). In schizophrenics fewer pyramidal cells but more interneurons were immunostained. Our data point to an involvement of the protein in the altered hippocampal circuitry in schizophrenia.     

Toward a more complete recognition of immunoreactive antigens in squamous cell lung carcinoma

There is very limited knowledge about the antibody response against tumor-expressed antigens in lung cancer. To arrive at a more complete picture of lung cancer antigens, we generated 2 cDNA libraries from squamous cell lung carcinoma and isolated 15 immunogenic antigens using autologous sera. Among the antigens most frequently identified were the lymphoid blast crisis oncogene (LBC), an unknown hypothetical protein and the p53-binding protein (TP53 BP), which have already been associated with tumor development. Of the immunogenic antigens, 6 map to chromosomes that are frequently altered in squamous cell lung carcinoma. SEREX database analysis showed that 7 of the identified immunogenic antigens have been associated with the humoral immune response in other human tumors. Screening with heterologous sera of patients with lung carcinoma identified 4 antigens, including human protein kinase C and TP53 BP, which have also been found by autologous screening. Only 1 of the 15 identified antigens reacted with any of the 36 control sera, which were taken from individuals without known disease. Sera from adenocarcinoma and large cell carcinoma of the lung were not reactive for the antigens. In summary, using 2 newly established cDNA libraries, we isolated 15 novel antigens, which were subsequently evaluated for the frequency of their corresponding antibodies in autologous, normal and heterologous sera; their chromosomal localization; and their correlation with survival after surgery.     

Docetaxel and carboplatin as second-line chemotherapy for metastatic non-small cell lung cancer

The aim of this pilot study was to evaluate the activity and toxicity of docetaxel plus carboplatin as second-line treatment in patients with metastatic non-small cell lung cancer (NSCLC). Patients received docetaxel 75 mg/m(2) followed by carboplatin AUC 5 on day 1 every 3 weeks in an out-patient setting. Twenty-six patients were enrolled; 23 patients were diagnosed stage IV disease and three patients had a IIIB disease with malignant pleural effusion. The median interval from first to second-line treatment was 3.5 months (range 1-13). Patients received a total of 101 cycles with a median number of four cycles per patient (range 1-6). Five patients achieved a partial remission (19.23%; 95% confidence interval (CI) 6.55-39.35%), 11 had stable disease (42.31%) and ten progressed (38.46%) after initiation of second-line therapy. Median survival was 243 days (95% CI 182-336 days), the median progression-free survival was 118 days (95% CI 89-170 days), and the 1-year survival rate was 25.98% (95% CI 6.33-45.63%). Moderate haematological and mild nonhaematological toxicities were observed. No treatment-related death occurred. In conclusion, docetaxel plus carboplatin as second-line regimen has a reasonable activity with good tolerance and encouraging survival data.