Socioeconomic determinants of rates of consultation in general practice based on fourth national morbidity survey of general practices.

OBJECTIVE--To identify the socioeconomic determinants of consultation rates in general practice. DESIGN--Analysis of data from the fourth national morbidity survey of general practices (MSGP4) including sociodemographic details of individual patients and small area statistics from the 1991 census. Multilevel modelling techniques were used to take account of both individual patient data and small area statistics to relate socioeconomic and health status factors directly to a measure of general practitioner workload. RESULTS--Higher rates of consultations were found in patients who were classified as permanently sick, unemployed (especially those who became unemployed during the study year), living in rented accommodation, from the Indian subcontinent, living with a spouse or partner (women only), children living with two parents (girls only), and living in urban areas, especially those living relatively near the practice. When characteristics of individual patients are known and controlled for the role of "indices of deprivation" is considerably reduced. The effect of individual sociodemographic characteristics were shown to vary between different areas. CONCLUSIONS--Demographic and socioeconomic factors can act as powerful predictors of consultation patterns. Though it will always be necessary to retain some local planning discretion, the sets of coefficients estimated for individual level factors, area level characteristics, and for practice groupings may be sufficient to provide an indicative level of demand for general medical services. Although the problems in using socioeconomic data from individual patients would be substantial, these results are relevant to the development of a resource allocation formula for general practice.     

不同育秧方式和插植密度下晚籼稻群体动态结构的研究

不同育秧方式和插植密度下晚籼稻群体动态结构存在差异。旱育秧群体分蘖速度快,分蘖能力强。稀植可促进个体分蘖多发、有效穗数增多,但旱育稀植并无分蘖早发的优势。旱育稀植使主茎基部叶片变短而上部叶片变长,生育后期叶面积消长平稳,地上部干物质积累较多。旱育秧、稀植都使主茎叶总数增多,全生育期延长。     

High Levels of Ascorbic Acid, Not Glutathione, in the CNS of Anoxia-Tolerant Reptiles Contrasted with Levels in Anoxia-Intolerant Species

Abstract: Ascorbic acid and glutathione (GSH) are antioxidants and free radical scavengers that provide the first line of defense against oxidative damage in the CNS. Using HPLC with electrochemical detection, we determined tissue contents of these antioxidants in brain and spinal cord in species with varying abilities to tolerate anoxia, including anoxia-tolerant pond and box turtles, moderately tolerant garter snakes, anoxia-intolerant clawed frogs (Xenopus laevis), and intolerant Long-Evans hooded rats. These data were compared with ascorbate and GSH levels in selected regions of guinea pig CNS, human cortex, and values from the literature. Ascorbate levels in turtles were typically 100% higher than those in rat. Cortex, olfactory bulb, and dorsal ventricular ridge had the highest content in turtle, 5–6 µmol g^?1 of tissue wet weight, which was twice that in rat cortex (2.82 ± 0.05 µmol g^?1) and threefold greater than in guinea pig cortex (1.71 ± 0.03 µmol g^?1). Regionally distinct levels (2–4 µmol g^?1) were found in turtle cerebellum, optic lobe, brainstem, and spinal cord, with a decreasing anterior-to-posterior gradient. Ascorbate was lowest in white matter (optic nerve) in each species. Snake cortex and brainstem had significantly higher ascorbate levels than in rat or guinea pig, although other regions had comparable or lower levels. Frog ascorbate was generally in an intermediate range between that in rat and guinea pig. In contrast to ascorbate, GSH levels in anoxia-tolerant turtles, 2–3 µmol g^?1 of tissue wet weight, were similar to those in mammalian or amphibian brain, with no consistent pattern associated with anoxia tolerance. GSH levels in pond turtle CNS were significantly higher (by 10–20%) than in rat for several regions but were generally lower than in guinea pig or frog. GSH in box turtle and snake CNS were the same or lower than in rat or guinea pig. The distribution GSH in the CNS also had a decreasing anterior-to-posterior gradient but with less variability than ascorbate; levels were similar in optic nerve, brainstem, and spinal cord. The paradoxically high levels of ascorbate in turtle brain, which has a lower rate of oxidative metabolism than mammalian, suggest that ascorbate is an essential cerebral antioxidant. High levels may have evolved to protect cells from oxidative damage when aerobic metabolism resumes after a hypoxic dive.     

Rapid Glutamate Decarboxylase Assay for Detection of Escherichia coli

Volume 59, no. 12, p. 4347, column 1, line 3 from bottom: "500 x g" should read "2,500 x g." [This corrects the article on p. 4347 in vol. 59.].     

Marine nematodes of the family Draconematidae (Nemata): a synthesis with phylogenetic relationships

The family Draconematidae is reviewed. Diagnoses of all taxa are updated or emended, basedupon an evaluation of diagnostic features. Aphylogenetic analysis at the genus level based onparsimony suggested that Tenuidraconema belongsto the Draconematinae. A new genus Bathychaetosoma is erected to accomodate B.uchidai (Kito, 1983). It is characterized by acephalic region with a smooth, non-thickened cuticleand numerous cephalic adhesion tubes located posteriorto the head region and extending over more than twohead diameters along the cervical region.     

Structural Comparisons of Muscle and Nonmuscle Actins Give Insights Into the Evolution of Their Functional Differences

Actin is a highly conserved protein although many isoforms exist. In vertebrates and insects the different actin isoforms can be grouped by their amino acid sequence and tissue-specific gene expression into muscle and nonmuscle actins, suggesting that the different actins may have a functional significance. We ask here whether atomic models for G- and F-actins may help to explain this functional diversity. Using a molecular graphics program we have mapped the few amino acids that differ between isoactins. A small number of residues specific for muscle actins are buried in internal positions and some present a remarkable organization. Within the molecule, the replacements observed between muscle and nonmuscle actins are often accompanied by compensatory changes. The others are dispersed on the protein surface, except for a cluster located at the N-terminus which protrudes outward. Only a few of these residues specific for muscle actins are present in known ligand binding sites except the N-terminus, which has a sequence specific for each isoactin and is directly implicated in the binding to myosin. When we simulated the replacements of side chains of residues specific for muscle actins to those specific for nonmuscle actins, the N-terminus appears to be less compact and more flexible in nonmuscle actins. This would represent the first conformational grounds for proposing that muscle and nonmuscle actins may be functionally distinguishable. The rest of the molecule is very similar or identical in all the actins, except for a possible higher internal flexibility in muscle actins. We propose that muscle actin genes have evolved from genes of nonmuscle actins by substitutions leading to some conformational changes in the protruding N-terminus and the internal dynamics of the main body of the protein. Received: 15 March 1996 / Accepted: 14 July 1996     

Formation of native hepatitis C virus glycoprotein complexes.

The hepatitis C virus (HCV) glycoproteins (E1 and E2) interact to form a heterodimeric complex, which has been proposed as a functional subunit of the HCV virion envelope. As examined in cell culture transient-expression assays, the formation of properly folded, noncovalently associated E1E2 complexes is a slow and inefficient process. Due to lack of appropriate immunological reagents, it has been difficult to distinguish between glycoprotein molecules that undergo productive folding and assembly from those which follow a nonproductive pathway leading to misfolding and aggregation. Here we report the isolation and characterization of a conformation-sensitive E2-reactive monoclonal antibody (H2). The H2 monoclonal antibody selectively recognizes slowly maturing E1E2 heterodimers which are noncovalently linked, protease resistant, and no longer associated with the endoplasmic reticulum chaperone calnexin. This complex probably represents the native prebudding form of the HCV glycoprotein heterodimer. Besides providing a novel reagent for basic studies on HCV virion assembly and entry, this monoclonal antibody should be useful for optimizing production and isolation of native HCV glycoprotein complexes for serodiagnostic and vaccine applications.     

Immunization with nonstructural proteins promotes functional recovery of alphavirus-infected neurons.

The encephalitic alphaviruses are useful models for understanding virus-neuron interactions. A neurovirulent strain of Sindbis virus (NSV) causes fatal paralysis in mice by infecting motor neurons and inducing apoptosis of these nonrenewable cells. Antibodies to the surface glycoproteins suppress virus replication, but other recovery-promoting components of the immune response have not been recognized. We assessed the effect on the outcome of NSV-induced encephalomyelitis of immunization of mice with nonstructural proteins (nsPs) by using recombinant vaccinia viruses. Mice immunized with vaccinia virus expressing nsPs and challenged with NSV initially developed paralysis similar to unimmunized mice but then recovered neurologic function. Mice preimmunized with vaccinia virus expressing structural proteins were completely protected from paralysis. Mice immunized with vaccinia virus alone showed paralysis with little evidence of recovery. Vaccinia virus expressing only nsP2 was as effective as vaccinia virus expressing all the nsPs. Protection provided by immunity to nsPs was not associated with a reduction in virus replication or with improved antibody responses to structural proteins. Protection could not be passively transferred with nsP immune serum. The depletion of T cells at the time of NSV infection decreased protection. The data show that antiviral immune responses can improve the ability of neurons to survive infection and to recover function without altering virus replication.     

Secondary structure determination of the conserved 98-base sequence at the 3' terminus of hepatitis C virus genome RNA.

The RNA genome of hepatitis C virus (HCV) terminates with a highly conserved 98-base sequence. Enzymatic and chemical approaches were used to define the secondary structure of this 3'-terminal element in RNA transcribed in vitro from cloned cDNA. Both approaches yielded data consistent with a stable stem-loop structure within the 3'-terminal 46 bases. In contrast, the 5' 52 nucleotides of this 98-base element appear to be less ordered and may exist in multiple conformations. Under the experimental conditions tested, interaction between the 3' 98 bases and upstream HCV sequences was not detected. These data provide valuable information for future experiments aimed at identifying host and/or viral proteins which interact with this highly conserved RNA element.