The influence of latitude on the concentration of vitamin D3 and 25-hydroxy-vitamin D3 in Australian red meat

There is little information on the vitamin D content of Australian red meat or on the possible influence of latitude on this content. To determine the content of vitamin D₃ and 25-hydroxy-vitamin D₃ (25OHD₃), lamb and beef were analysed from 34° S with LC–IT-MS. To investigate the possible influence of latitude on vitamin D in meat, the lean meat and fat from five cuts of beef were analysed from 17° S and 41° S. Lamb contained 0.10 μg vitamin D₃/100 g and 0.20 μg 25OHD₃/100 g lean meat, while beef contained 0.12 μg vitamin D₃ and 0.27 μg 25OHD₃/100 g (lean meat). Latitude had no effect on the vitamin D₃ (P = 0.21) or 25OHD₃ (P = 0.29) content of lean beef, but fat from cattle in the 17° S latitude group contained significantly higher (P < 0.01) concentrations of vitamin D₃ than fat from the 41° S group of cattle.     

Complex serology and immune response of mice to variant high-molecular-weight O polysaccharides isolated from Pseudomonas aeruginosa serogroup O2 strains

The O antigen of the Pseudomonas aeruginosa lipopolysaccharide is the optimal target for protective antibodies, but the unusual and complex nature of their sugar substituents has made it difficult to define the range of these structures needed in an effective vaccine. Most clinical isolates of P. aeruginosa can be classified into 10 O-antigen serogroups, but slight chemical differences among O polysaccharides within a serogroup give rise to subtype epitopes. These epitopes could impact the reactivity of O-antigen-specific antibodies, as well as the susceptibility of a target strain to protective, opsonic antibodies. To define parameters of serogroup and subtype-epitope immunogenicity, antigenicity, and surface expression on P. aeruginosa cells, we prepared high-molecular-weight O-polysaccharide vaccines from strains of P. aeruginosa serogroup O2, for which eight structurally variant O antigens expressing six defined subtype epitopes (O2a to O2f) have been identified. A complex pattern of immune responses to these antigens was observed following vaccination of mice. The high-molecular-weight O polysaccharides were generally more immunogenic at low doses (1 and 10 microg) than at a high dose (50 microg) and usually elicited antibodies that opsonized the homologous strain for phagocytic killing. Some of the individual polysaccharides elicited cross-opsonic antibodies to a variable number of strains that express all of the defined serogroup O2 subtype epitopes. Combination into one vaccine of two antigens that individually elicited cross-reactive opsonic antibodies to most members of the O2 serogroup inhibited, instead of enhanced, the production of antibodies broadly reactive with most serogroup O2 subtype strains. Thus, immune responses to P. aeruginosa O antigens may be restricted to a limited range of epitopes on structurally complex O antigens, and combining multiple related antigens into a single vaccine formulation may inhibit the production of those antibodies best able to protect against most P. aeruginosa strains within a given O-antigen serogroup.     

Future of endoscopy in nonvariceal upper gastrointestinal bleeding. What remains to be done

The centennial of the American Gastroenterological Association provides an occasion for a critical appraisal of past developments and future directions in endoscopy. The relevance of recent technologic advances in endoscopy must be questioned, and practical management issues need to be considered. New strategies are being developed that permit physicians to impact on the incidence and recurrence of bleeding peptic ulcers.     

Bulk high-T c magnetometer

We report a study of a bulk YBCO magnetometer based on the detection of harmonics during nonlinear magnetization. For a low-DC field, the amplitude of the even harmonic appearing at the pickup coil depends linearly on the DC field intensity. The performance of the magnetometer depends on the quality of the sample, and the intensity and frequency of the AC field excitation. At higherH _ac, the fourth harmonic becomes more sensitive than the second harmonic. The hysteresis in the magnetometer for DC field measurement has been reported.     

A headache protocol for nurses: effectiveness and efficiency

To test the effectiveness and efficiency of a nurse-administered protocol for headache in the primary care setting, we conducted a prospective controlled trial. Two hundred three randomly allocated patients were evaluated by nurses using the protocol who managed independently 55.2% of the patients and received physician consultation on the others. A total of 193 patients were randomly allocated to the physician-control group. Nurse-protocol group patients experienced equivalent symptomatic relief and expressed significantly greater satisfaction with the care they had received than did patients in the physician-control group. A retrospective study of the presenting findings in patients with serious diseases of the CNS provided evidence supporting the safety of the protocol logic. We conclude that nurse-protocol management of headache in this primary care practice was effective and efficient.