流行性出血热自然状态监测研究

１９８６年１０月至１９９０年３月，先后在贵州省ＥＨＦ野鼠型疫区遵义、安顺两县和家鼠型疫区凯里市选点，监测丘陵地区自然状态下影响ＥＨＦ流行的主要因素，连续两年的逐月监测结果表明，人间流行的强度、临床表现和流行特征的不同与主要宿主动物种类、密度和带病毒率以及病原体的毒力和型别有关。     

Assessment of dental health state utilities

The term "health state utility" implies the assigning of a numerical value to a state of health. Assessment of the success of health care procedures, using health state utilities, enables evaluation of available treatments and procedures in terms of differing health outcomes and therefore facilitates cost-benefit analyses. Although measurement of general health state utilities has become increasingly common in medicine using a variety of techniques, few attempts have as yet been made in dentistry to place valuations on different dental health states. The absence of tried and tested methods for measuring tooth quality make the benefits gained from preventive and restorative dental programmes difficult to quantify. The aim of this study was to assess the average utility values, held by a group of dentists and a group of members of the general public, for four different tooth states which it was hypothesised would have different values. These were 1) a decayed and painful posterior tooth; 2) a decayed and non-painful posterior tooth; 3) a posterior tooth which had been restored and would need further restorative treatment and 4) a permanently restored posterior tooth. A standard gamble questionnaire was used to elicit the utility values which were then substituted as "weightings" in a modified version of the "T-health" index (1). The results show that it is possible to assess dental health state utility values using the standard gamble method and that the average utility values of the dentists in the study were consistently higher than those of the general public.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hypoxia,energy state and pulmonary vasomotor tone

Vasomotor responses to hypoxia constitute a fundamental adaptation to a commonly encountered stress. It has long been suspected that changes in cellular energetics may modulate both hypoxic systemic artery vasodilatation (HSV) and hypoxic pulmonary artery vasoconstriction (HPV). Although limitation of energy has been shown to underlie hypoxic relaxation in some smooth muscles, the response to hypoxia in vascular smooth muscle does not appear to be a simple function of energy stores, but instead may involve perturbations of ATP or energy delivery to mechanisms controlling muscle force, and/or changes associated with anaerobic metabolism. Recent work in pulmonary vascular smooth muscle has demonstrated that energy stores are maintained during hypoxic pulmonary vasoconstriction, and that this is dependent on glucose availability and up-regulation of glycolysis. There is increasing evidence that glycolysis is preferentially coupled to a variety of membrane associated ATP dependent processes, including the Na(+) pump, Ca(2+)-ATPase, and possibly some protein kinases. These and other mechanisms may influence excitation-contraction coupling in both systemic and pulmonary arteries by effects on intracellular Ca(2+) and/or Ca(2+) sensitivity. Hypoxia has also been postulated to have major effects on other cytosolic second messenger systems including phosphatidylinositol pathways, cell redox state and mitochondrial reactive oxygen species production. This review examines the relationship between energy state, anaerobic respiration and hypoxic vasomotor tone, with a particular emphasis on hypoxic pulmonary vasoconstriction.     

The effect of intravenously administered salbutamol on serum potassium in asthmatic and nonasthmatic atopic subjects

The role of adrenergic mechanism in the pathogenesis of allergic disease is controversial. Recent experimental and clinical reports have suggested that -adrenergic blockade impairs and stimulation enhances extrarenal potassium uptake in humans. This led us to study the effect of the intravenous administration of salbutamol, a specific -2-adrenergic agonist, on serum potassium in 9 healthy subjects and in 23 patients with allergic asthma and/or rhinitis. Serum potassium fell significantly and reached a peak decline at the end of venous infusion in all the normal subjects. Seventeen atopic subjects showed a lower or absent serum K⁺ decrement: there was no difference between asthmatic and rhinitic patients. There was no relation among the salbutamol-induced serum potassium decrement, serum glucose increment, blood pressure and heart-rate changes, and nonspecific bronchial reactivity. These findings suggest that -2-adrenergic hyporesponsiveness is present only in some allergic patients.     

Packing and Uniaxial Alignment of Liquid Crystalline Oligofluorenes

Summary: Liquid crystalline oligomers of 9,9‐bis(2‐ethylhexyl)fluorene of defined degree of polymerization 4, 5, 6, and 7 were investigated by X‐ray diffraction in the non‐oriented and in the aligned state. The diffraction data give evidence for a smectic B type phase for all of the oligomers. Quenching below the glass transition does not change the structure of the liquid crystalline phase. This allows to align spin‐coated films of these oligomers on rubbed polyimide substrates to give monodomain films. These are stable against thermal disordering below T_g, e.g. at room temperature. The degree of alignment is characterized by the dichroic spectra and polarized fluorescence spectra. Dichroic ratios and polarization ratios increase substantially with the chain length and values as high as D = 23 and P = 41 are obtained for the heptamer. The type of packing of the oligomers in the LC phase is discussed based on the X‐ray single crystal structure of models. In one such model the packing of the 2‐ethylhexyl side chains could be fully resolved, while the other model reveals the torsional angle between adjacent fluorene units in the same molecule as 144.2° which corroborates earlier work based on fiber diffraction of corresponding polyfluorenes.

     

Structural Reasons for Restricted Backbone Motion in Poly(n‐alkyl methacrylates): Degree of Polymerization,Tacticity and Side‐Chain Length

Summary: The complex dynamics of poly(n‐alkyl methacrylates) is studied by advanced ¹³C NMR spectroscopy as well as mechanical and dielectric relaxation. Extended backbone conformations are identified as the molecular units involved in structural relaxation. From the variation in the degree of polymerization and a comparison with the presence of stereoregular sequences in the sample, the length of the extended units is determined to involve about five, at most ten monomeric units. Syndiotactic and isotactic sequences behave similarly. These findings are indicative of locally structured polymer melts.

     

Normal aging decreases regional homogeneity of the motor areas in the resting state

Our knowledge about aging modulation of the central motor system remains sparse and contradictory. In the current study, we used functional MRI (fMRI) to study the aging influence on regional homogeneity of the motor-related brain areas in the resting state. We found that regional homogeneity in extensive motor regions, like the cingulate motor area, cerebellum, primary motor cortex, premotor area, supplementary motor area, thalamus, globus pallidus and putamen was significantly decreased in aged subjects. Our study indicates that normal aging process may disrupt the function of motor areas in the resting state, which may contribute to the declined motor ability in aged population.     

The influence of the initial state of hydration on endocrine responses to exercise in the heat

Summary This study examines the effect of the initial state of hydration on hormone responses to prolonged exercise in the heat. Five subjects at two initial hydration levels (hypohydrated and hyperhydrated) were exposed to a 36°C environment for 3 h of intermittent exercise. During exercise, the subjects were either fluid-deprived, or rehydrated with water or an isotonic electrolyte sucrose solution (ISO). Both the stress hormones, adrenocorticotropic hormone and cortisol, and the main fluid regulatory hormones, aldosterone, renin activity (PRA) and arginine vasopressin (AVP), were measured in blood samples taken every hour. Prior hyperhydration significantly reduced initial AVP, aldosterone and PRA levels. However, except for AVP, which responded to exercise significantly less in previously hyperhydrated subjects (p<0.05), the initial hydration state did not influence the subsequent vascular and hormonal responses when the subjects were fluid-deprived while exercising. Concurrent rehydration, either with water or with ISO, reduced or even abolished the hormonal responses. There were no significant differences according to the initial hydration state, except for PRA responses, which were significantly lower (p<0.01) in previously hyperhydrated subjects who also received water during exercise. These results indicate that prior hydration levels influence only slightly the hormonal responses to prolonged exercise in the heat. Progressive rehydration during exercise, especially when extra electrolytes are given, is more efficient in maintaining plasma volume and osmolarity and in reducing the hormonal responses.     

Advanced 1H Solid‐State NMR Spectroscopy on Hydrogels, 1

Summary: The nature of the pH dependent collapse of poly(methacrylic acid) (PMAA) hydrogels is investigated using recent ¹H solid‐state NMR methods. In aqueous solution, PMAA changes from an expanded conformation at high pHs to a compact contracted form at low pHs, where hydrogen bonds play a central role. In solid‐state ¹H NMR spectra, recorded under fast magic angle spinning (MAS), dried PMAA samples previously collapsed at low pHs show characteristic signals in the spectral region of the carboxylic acid protons. With the aid of 2D ¹H‐¹H double‐quantum (DQ) MAS NMR spectra, three signals can be distinguished at 8, 10.5 and 12.5 ppm, which are attributed to free carboxylic groups and two different types of hydrogen bonded forms, respectively. The 12.5 ppm signal arises from the hydrogen bond with the shortest H? H distance, corresponding to the form that is most stable with respect to increasing temperature and pH. The weaker hydrogen‐bonded form (with a signal at 10.5 ppm) requires a slightly lower pH, while the free acid signal (at 8 ppm) emerges under the most acidic medium. Moreover, the stabilities of the hydrogen‐bonded carboxylic acid dimers can be inferred from the proton‐proton distances within the dimers, i.e. (275 ± 5) pm and (295 ± 15) pm for the protons at 12.5 and 10.5 ppm, respectively, which are determined by means of DQ MAS sideband patterns. Both the stability of the hydrogen bonds and the acidity of the protons may be related to the stereochemistry and the conformation of the PMAA chains.

     

Criteria for grading in the Ljubljana classification of epithelial hyperplastic laryngeal lesions. A study by members of the Working Group on Epithelial Hyperplastic Laryngeal Lesions of the European Society of Pathology

AIMS: To validate histological criteria for the grading of epithelial hyperplastic laryngeal lesions (EHHL) (dysplastic laryngeal lesions), we used a system that had been devised and tested in Ljubljana, Slovenia over many years and was felt to be more appropriate to laryngeal pathology than is the commonly-used model of intraepithelial neoplasia in the cervix. METHODS AND RESULTS: Vocal cord biopsies of 45 patients with a broad spectrum of EHLL were reviewed. Detailed histological criteria were formulated for each of the four grades of EHLL in the Ljubljana classification, comprising simple hyperplasia (benign spinous layer augmentation), abnormal hyperplasia (benign basal and parabasal layer augmentation), atypical hyperplasia (risky for malignancy) and carcinoma in situ (actually malignant, but without invasion). CONCLUSIONS: Using these criteria a high degree of concordance of histological diagnoses of grading levels for the Ljubljana classification was achieved between the pathologists of the Working Group. The system was found to be more precise for routine diagnostic work than the others in vogue. The different grades of the Ljubljana classification correspond to significantly different levels yielded in each grade by the semiobjective methods of quantitative morphometry and immunohistochemistry.