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To investigate the joint association of patient and strain characteristics with the outcome of meningococcal disease (MD), data were collected on 563 consecutive cases of MD reported between 1989 and 1990 in The Netherlands. The meningococcal isolates were characterized with regard to their surface characteristics. Sequelae occurred in 8.5% of the patients, and were only associated with the presence of bacteraemia. The case-fatality rate was 7.7%. Infants aged < or = 5 months and patients in the age-groups of 10-19 years and > or = 50 years had an increased risk for a fatal outcome compared with children from 6 months to 9 years old (Odds Ratios [ORs]: 5.1, 3.4 and 9.8, respectively). The OR for females versus males was 2.3. The ORs for patients with bacteraemia, or a combination of bacteraemia and meningitis, compared with meningitic patients, were 2.3 and 3.1. Meningococcal strain characteristics did not influence the case-fatality rate substantially. In conclusion, host factors were found to be determinants for a fatal outcome of MD in The Netherlands from 1989 to 1990.

A strong association between HLA-DR2, DQ1 and narcolepsy-cataplexy has been known since 1986. In 1990 a subdivision (HLA-DR15, DQ6) was shown to be equally associated. Narcolepsy symptoms include rapid eye movement (REM)-sleep intrusion hallucinations during the day. Some narcoleptics may be so hallucinated that they become delusional and receive a diagnosis of schizophrenia. Fifty-six inpatient schizophrenics and 56 normal controls were compared to see if there was an excess of the narcolepsy-associated antigens (NAA) among schizophrenics. Patients had frequency of the NAA 3.89 times higher than controls. After a subset was studied by night (n = 9) and day (n = 7) polysomnography, two patients were found to be true narcoleptics. Their psychosis improved with treatment for narcolepsy. When NAA(+) and NAA(-) schizophrenics were compared, the NAA(+) subgroup had significantly higher Brief Psychiatric Rating Scale (BPRS) scores and more hospitalizations. There were no effects attributable only to gender or race. We conclude that narcolepsy can simulate schizophrenia in some cases, and that even in nonnarcoleptic patients, the HLA-DR15,DQ6 antigens mark a group of severe schizophrenics that merits further study.

The ability to fabricate nanometer-sized structures that are stable in air has the potential to contribute significantly to the advancement of new nanotechnologies and our understanding of nanoscale systems. Laser light can be used to control the motion of atoms on a nanoscopic scale. Chromium atoms were focused by a standing-wave laser field as they deposited onto a silicon substrate. The resulting nanostructure consisted of a series of narrow lines covering 0.4 millimeter by 1 millimeter. Atomic force microscopy measurements showed a line width of 65 +/- 6 nanometers, a spacing of 212.78 nanometers, and a height of 34 +/-+ 10 nanometers. The observed line widths and shapes are compared with the predictions of a semiclassical atom optical model.

Objective: To assess the secondary attack rate (SAR) of meningococcal disease among the household contacts of primary patients and to describe the use of chemoprophylaxis in the Netherlands., Design: Descriptive, nation-wide survey., Methods: Information was collected of patients with meningococcal disease, reported between April 1st, 1989 and April 30th, 1990, and their household contacts. A household contact suffering from meningococcal disease between 24 hours and 1 month after hospital admission of the primary patient, was considered to be a secondary case. Chemoprophylaxis was considered appropriate if rifampicin or minocycline had been prescribed to all household contacts within a maximum of one day after admission of the primary patient., Results: There were 5 secondary cases (SAR: 0.3%). Chemoprophylaxis was prescribed to 627 of 1130 household contacts (55%). Of those the prophylaxis was considered appropriate in 46%. 2 secondary cases were not given any prophylaxis, 2 received penicillin and 1 rifampicin. Of the primary patients, 6% were given prophylaxis during their hospital stay. All meningococci, isolated from pairs of secondary and primary patients, were rifampicin sensitive., Conclusions: The SAR of meningococcal disease in the Netherlands is similar to that in other countries. Although prescription of chemoprophylaxis is not recommended by the government, it is prescribed to 55% of the household contacts, and in almost half of these instances it was considered to be appropriate. Chemoprophylaxis is rarely prescribed to primary patients. Recommendations concerning chemoprophylaxis in the Netherlands are in need of reappraisal. Based on the results from this study and the literature, the prescription of chemoprophylaxis to all household contacts of a patient with meningococcal disease, and to the index patient, is recommended.

In order to explain a threefold increase in the incidence of meningococcal disease in the Netherlands during the 1980s, we serotyped and subtyped Neisseria meningitidis isolates recovered between 1958 and 1990 from > 3,000 patients with systemic disease. No single strain could be held responsible for the increase. Apart from the newly introduced strain B:4:P1.4, which became the most prevalent phenotype in 1990 (21% of all isolates), the majority of the cases in 1990 were caused by many different strains that were already present in the Netherlands before 1980. For the period 1980-1990, a shift in the age distribution of patients with meningococcal disease from younger to older age categories was found, particularly with regard to cases due to meningococci of serogroup B; this shift is explained by the changing distribution of serotypes and subtypes within serogroup B. A polyvalent group B, class 1 outer-membrane-protein vaccine of a stable composition could theoretically have prevented approximately 80% of all group B meningococcal infections in the Netherlands during the past 30 years.

Many schizophrenic patients exhibit significant neuropsychological impairment, and age disorientation is considered to be one of the more extreme manifestations. To evaluate clinical correlates of age disorientation with reference to the course of schizophrenic illness, we compared 39 deteriorated chronic Kraepelinian schizophrenic patients and 39 nondeteriorated schizophrenic patients early in the course of illness. Age disorientation was observed in 36% of patients in the Kraepelinian group, but in no patient in the non-Kraepelinian group. In the Kraepelinian group, age disorientation was unrelated to positive/negative symptoms or illness duration. Our data suggest that age disorientation may be a function of aging in schizophrenia, but is not merely a function of chronicity.

An immunoassay was developed to detect Marek's disease virus (MDV) antigen on the tips of feathers obtained from MDV-infected chickens. MDV in follicular debris on the feather tip was demonstrated by use of a specific monoclonal antibody. The principle of an indirect ELISA was employed and the feather tip was used as the solid phase. Presence of MDV was reflected by a dark brown precipitate on the feather tip which could be observed by naked eye. This test system proved to be more sensitive than the agar-gel precipitation (AGP) test as all feather tips of MDV-infected animals gave a positive reaction in the feather tip-ELISA whereas about a half yielded a detectable precipitate in the AGP. Advantages of this feather tip-ELISA and applications are discussed.

Irritant contact dermatitis is common in metalworkers exposed to metalworking fluids (MWF). The irritancy of 3 commercially available water-based cutting fluids in maximal user's concentration and 2 neat oils was investigated in 23 healthy volunteers. Additionally, the irritancy of some groups of components of the cutting fluids was studied. After Sellotape stripping, repeated patch tests were performed over 5 days and evaluated by a visual score (VS) and by laser Doppler flowmetry (LDF). In general, the MWF caused marginal skin irritation. In a comparison of the MWF and water, the cutting fluids were ranked higher in irritancy than the neat oils, but the effect of only one cutting fluid could be distinguished from that of water. The components of the cutting fluids also caused no strong reactions. The LDF response showed that one emulsifier was more irritant than water and according to the VS, one corrosion inhibitor was the most irritant. The correlation coefficient between the VS and the LDF response was probably diminished by a strong adverse reaction to the fixing tape in many volunteers. From this experiment, it was concluded that MWF are generally only mildly irritant when used in proper concentrations. However, orthoergic contact dermatitis often develops as a result of repeated and cumulative subclinical insults, in which MWF, especially water-based, play a crucial role because exposure at work is often extensive.

Immuno- and enzyme-histochemical staining procedures were used to investigate in vivo the interaction of Marek's disease virus (MDV) with splenic non-lymphoid cells. The newly developed monoclonal antibody D-35.1, which recognizes all three MDV serotypes, was used to study the localization of MDV at various times after intramuscular inoculation of 1-day-old chicks with MDV strain K. The D-35.1-positive cells were detected in the bursa of Fabricius, spleen, thymus, proventriculus, and cecal tonsils, and the number of chickens showing the cells increased between days 4 and 10. From day 21, the skin of the chickens contained D-35.1-positive feather follicles. The D-35.1 monoclonal antibody did not stain any cells in peripheral blood, nerves, kidney, and gonads at any time. In addition, D-35.1-positive cells were not detected in lymphoproliferative lesions in visceral organs and peripheral nerves. Double staining procedures on serial sections using monoclonal antibody CVI-ChNL-68.2, specific for splenic ellipsoid-associated reticulum cells, revealed that the majority of D-35.1-positive cells were situated in the peri-capillary sheath of reticulum cells at day 10. The sheath of cells detected by monoclonal antibody CVI-ChNL-68.2 was disrupted, and they were clustered around D-35.1-positive cells. These results support the hypothesis that ellipsoid-associated reticulum cells are involved in the early pathogenesis of Marek's disease.

For the calculation of the forces in the hip, knee and ankle joints during walking the knowledge of the three-dimensional movements of the human body and of the forces between foot and ground is a prerequisite. It is shown how this information may be obtained and what accuracy is obtainable. For the calculation of the statically indeterminate system of the lower limbs, consisting of muscles, bones and joints an optimization method is applied. The optimization criterion is the minimization of the muscle forces. Measurements were taken with seventeen male and five female persons. The maximum joint forces are plotted against gait speed, body weight and body size. In addition some statistical distributions are presented.

The mechanical force flow distribution produced by the hip joint endoprosthesis in the remaining, living femur and its deviation from that of the natural bone have a considerable influence on the quality of the bone-endoprosthesis compound and its duration of life. The loads are calculated for the natural bone as the reference system as well as the compound with conventional endoprostheses and a new type, the Tension-band-Endoprosthesis (R-G). For the calculation the finite element method is used by application of three-dimensional tetrahedron elements. It becomes apparent that in the case of the R-G-Endoprosthesis the induced stresses within the medial range of the remaining bone are far less unphysiological than in the case of the conventional endoprosthesis.

A method is presented which allows survival and continued differentiation of male mouse germ cells for up to 12 days in culture. The system uses continuous flow perfusion at 20 degrees C in a completely chemically defined medium. To show differentiation through meiosis, mice were treated with hydroxyurea (HU) which creates a gap in the spermatogenic line. Suspensions of testicular cells of these mice, completely lacking pachytene/diplotene stages, were put into culture. After 7 or 10 days culturing, differentiation was demonstrated by the appearance of pachytene and diplotene stages and round spermatids. The velocity of the differentiation in vitro was found the same as would be expected in vivo. The number of cells which show differentiation throughout meiosis is less than would be expected in cultures of testicular cells of mice which were not treated with hydroxyurea.