Predominance of capsular polysaccharide type 5 among oxacillin-resistant Staphylococcus aureus.

The relationship between capsular polysaccharide types 5 and 8 and resistance of Staphylococcus aureus to oxacillin was studied with a collection of 406 clinical isolates from six French hospitals. Of 175 type 5 isolates, 84 (48%) were resistant to oxacillin. In contrast, only 8 of 160 type 8 isolates (5%) and 5 of 71 nontypeable isolates (7%) were resistant to oxacillin. Therefore, capsular typing of clinical isolates of S. aureus may facilitate the choice of first-line antibiotic therapy.     

Japanese encephalitis virus-vaccinia recombinants produce particulate forms of the structural membrane proteins and induce high levels of protection against lethal JEV infection.

Four recombinant vaccinia viruses were engineered for expression of different portions of the Japanese encephalitis virus (JEV) open reading frame. All four recombinant vaccinias contained the NS1 and NS2A genes, and each of these viruses specified the synthesis, glycosylation, and secretion of the nonstructural glycoprotein (NS1). All four recombinants also contained the E gene, and each virus correctly directed the synthesis and glycosylation of the envelope glycoprotein (E). Interestingly, two of these viruses (vP555 and vP650), which expressed the prM gene in addition to E and NS1, produced an extracellular hemagglutinin containing M and E that migrated in sucrose gradients similarly to the slowly-sedimenting hemagglutinin found in the culture fluid of JEV-infected cells. Immunization of 3-week-old mice with the recombinant viruses vP555 and vP658 resulted in immune responses to NS1, whereas only the virus that directed the synthesis of extracellular forms of E (vP555) induced an immune response to E. Both viruses provided protection against lethal challenge with JEV. Animals given two inoculations with vP555 were fully protected from greater than 10,000 LD50 of JEV. This high level of protection was correlated with the production of high titers of neutralizing and hemagglutination-inhibiting antibodies.     

Fiber type composition of muscle units in the cat diaphragm

The fiber type composition of muscle units in the cat diaphragm was examined. As expected, slow-twitch units were composed of type I fibers and fast units were composed of type II fibers. Fast fatigable units were composed of type IIB fibers and fast fatigue resistant units were composed of type IIA fibers. Surprisingly, fast fatigue intermediate units were comprised of both type IIA and IIB fibers.     

Behavioral effects of severe and moderate early malnutrition

Rats with a history of prenatal and early postnatal undernutrition (6 or 8% casein diets) were "nutritionally rehabilitated" at weaning, and were compared to well-fed animals (25% casein) at maturity. The severely-malnourished (6%) animals were hyperactive in the open field and when tested in a stabilimeter. They also appeared to be highly active during the early trials in 8-arm radial maze testing where they made more arm entries and re-entry errors than the well-fed rats. In terms of trials to criterion, however, their scores on the radial maze and on a spatial alternation task fell within normal limits. The moderately-malnourished (8%) rats tended to perform at control levels on the learning measures, but these rats were not as active as the 6% rats on the measures of activity. Brain size and weight differences among the three groups of rats also are presented and discussed.     

Murine Immunoprotective Activity of Klebsiella pneumoniae Cell Surface Preparations: Comparative Study with Ribosomal Preparations

Cell surface preparations and ribosomal preparations were extracted from Klebsiella pneumoniae. Agar gel diffusion with antisera to cell surface preparations or ribosomal preparations indicated common antigenic components among the preparations. Lipopolysaccharide and capsular polysaccharide were identified in the cell surface preparations. These results and the previous identification of lipopolysaccharide and capsular polysaccharide in ribosomal preparations suggest that these antigens are responsible for the immunochemical cross-reactivity observed among these two bacterial extracts. Active protection could be induced in mice by these two preparations. On a dry-weight basis, cell surface preparations provided better immunoprotective activity than did ribosomal preparations. However, the 50% protective dose of both preparations is practically the same on the basis of their capsular polysaccharide content. These results are consistent with the hypothesis that the immunoprotective moiety of ribosomal preparations is the contaminating cell surface antigens. Furthermore, the low level of nucleotidic components detected in purified cell surface preparations led us to infer that the immunoprotective activity of capsular polysaccharide may not be dependent on the adjuvant activity of ribonucleic acid. The involvement of capsular polysaccharide in the immunoprotective capacity of cell surface preparations is demonstrated either by using a degradation of this antigen by K. pneumoniae bacteriophage K2-associated glycanase or by using a preparation extracted from a noncapsulated mutant of K. pneumoniae. Nevertheless, the low protective ability of purified capsular polysaccharides is in contrast to its greater activity when induced in bacterial cell surface preparations. The protective activity of K. pneumoniae capsular polysaccharide may be dependent on its association with other surface antigenic components present in cell surface preparations or may be dependent on its native form in the bacterial cell surface.     

Theoretical and practical problems in the measurement of the mental health of populations. Quebec health survey

The authors present the process of setting up a mental health inquiry. The "Enquête Santé Québec" was conducted at the request of the Ministry of Social Affairs in order to identify the problems, needs and priority intervention sectors in the health field. The inquiry was carried out on a large scale at the pilot stage, collecting information on 4,000 people in rural and urban areas. The principal options chosen are briefly discussed: type of mental health to be measured, sample methods, choice of instruments, validation work and some results.     

The response to exercise with constant energy intake in identical twins

Seven pairs of young adult male identical twins completed a negative energy balance protocol during which they exercised on cycle ergometers twice a day, 9 out of 10 days, over a period of 93 days while being kept on a constant daily energy and nutrient intake. The total energy deficit caused by exercise above the estimated energy cost of body weight maintenance reached 244 +/- 9.8 MJ (Mean +/- SEM). Baseline energy intake was estimated over a period of 17 days preceding the negative energy balance protocol. Mean body weight loss was 5.0 kg (SEM = 0.6) (p < 0.001) and it was entirely accounted for by the loss of fat mass (p < 0.001). Fat-free mass was unchanged. Body energy losses reached 191 MJ (SEM = 24) (p < 0.001) which represented about 78% of the estimated energy deficit. Subcutaneous fat loss was slightly more pronounced on the trunk than on the limbs as estimated from skinfolds, circumferences, and computed tomograply (CT). The reduction in CT-assessed abdominal visceral fat was quite striking, from 81 cm2 (SEM = 5) to 52 cm2 (SEM = 6) (p < 0.001). At the same submaximal power output level, subjects oxidized more lipids than carbohydrates after the program as indicated by the changes in the respiratory exchange ratio (p < or = 0.05). Intrapair resemblance was observed for the changes in body weight (p < 0.05), fat mass (P < 0.01), percent fat (p < 0.01), body energy content (p < 0.01), sum of 10 skinfolds (p < 0.01), abdominal visceral fat (p < 0.01), fasting plasma triglycerides (p < 0.05) and cholesterol (p < 0.05), maximal oxygen uptake (p < 0.05), and respiratory exchange ratio during submaximal work (p < 0.01). We conclude that even though there were large individual differences in response to the negative energy balance and exercise protocol, subjects with the same genotype were more alike in responses than subjects with different genotypes particularly for body fat, body energy, and abdominal visceral fat changes. High lipid oxidizers and low lipid oxidizers during submaximal exercise were also seen despite the fact that all subjects had experienced the same exercise and nutritional conditions for about three months.     

Contractile proteins in human fetoplacental vessels

OBJECTIVE: Our purpose was to compare the protein isoform composition of the contractile apparatus at different levels of the fetoplacental vessel musculature et term.STUDY DESIGN: Umbilical, chorionic, and stem villi vessel protein extracts were run on one- and two-dimensional gel electrophoresis; previously characterized human myometrium proteins were used as the smooth muscle proteins of reference.RESULTS: Fetoplacental vessel musculature exhibited a high ratio. The presence, in varying quantities, of myosin heavy chain and actin isoforms of smooth muscle type in the different vessels reflected their degree of differentiation. The presence of nonmuscle protein isoforms, particularly in stem villi vessels, indicated a certain degree of immaturity.CONCLUSIONS: The presence of smooth muscle contractile protein isoforms indicates that fetoplacental vessel musculature is highly differentiated. Regional modulation of fetoplacental blood flow could be, in part, the result of local differences in contractile apparatus protein composition.     

Predominant immunoglobulin A response to phase II antigen of Coxiella burnetii in acute Q fever

Diagnosis of acute Q fever is usually confirmed by serology, on the basis of anti-phase II antigen immunoglobulin M (IgM) titers of >/=1:50 and IgG titers of >/=1:200. Phase I antibodies, especially IgG and IgA, are predominant in chronic forms of the disease. However, between January 1982 and June 1998, we observed anti-phase II antigen IgA titers of >/=1:200 as the sole or main antibody response in 10 of 1,034 (0.96%) patients with acute Q fever for whom information was available. In order to determine whether specific epidemiological or clinical factors were associated with these serological profiles, we conducted a retrospective case-control study that included completion of a standardized questionnaire, which was given to 40 matched controls who also suffered from acute Q fever. The mean age of patients with elevated phase II IgA titers was significantly higher than that usually observed for patients with acute Q fever (P = 0.026); the patients were also more likely than controls to live in rural areas (P = 0.026) and to have increased levels of transaminase in blood (P = 0.03). Elevated IgA titers are usually associated with chronic Q fever and are directed mainly at phase I antigens. Although the significance of our findings is unexplained, we herein emphasize the fact that IgA antibodies are not specific for chronic forms of Q fever and that they may occasionally be observed in patients with acute disease. Moreover, as such antibody profiles may not be determined by most laboratories, which test only for total antibody titers to phase I and II antigens, the three isotype-specific Ig titers should be determined as the first step in diagnosing Q fever.