Biomedical subjects
Publications and source records attributed to R Howard.
A maltose-negative variant of Neisseria meningitidis, Slaterus Y, was recovered from a patient with meningitis. A report of the case is presented and the medical-legal significance of such an isolate is briefly discussed.
Chinese hamster ovary (CHO) cells in culture were exposed in a nuclear magnetic resonance (NMR) imaging apparatus to a strong magnetic field, pulsed field gradients, and radio frequency emissions. No chromosomal aberrations were induced even after an exposure of approximately 14 hours. No sister chromatid exchanges were induced by four-hour exposures to either low (average 7.2 mW) or high (average 61.2 mW) radio frequency power. When HeLa cells were exposed for 16 hours to an average radio frequency power of 61.2 mW, no inhibition of DNA synthesis was detectable. These data indicate that the conditions used for NMR imaging do not cause genetic damage which is detectable by any of these methods.
Intramuscular nitrogen tensions in Tursiops truncatus after a schedule of repetitive ocean dives suggest a lung collapse depth of about 70 meters and suggest that intramuscular circulation is maintained during unrestrained diving in the open ocean. Therefore, the bottle-nosed dolphin is not protected by lung collapse from the decompression hazards of dives to depths shallower than 70 meters.
Nine subjects were given to breath 10%, 20%, 30% and 40% nitrous oxide in oxygen. The inhaled gas concentrations were monitored by a mass spectrograph. At each gas concentration the CNV was measured in a standard long S1-S2 CNV paradigm to a click and tone with a mandatory button press at S2. The results confirmed the previous observations of Lader and Morris (1974) that the cortical evoked potential decreases rapidly with increasing concentrations of nitrous oxide. The CNV, however, against prediction remains surprisingly well preserved up to the borders of unconsciousness. In this situation there is little correlation between CNV amplitude and attention, arousal or reaction time.
An improved operative technique for funnel chest is described in detail. The results of operation with this procedure on 229 cases over the past 10 years are compared with those obtained, using an earlier technique, on 319 cases over the preceding 16 years.
Explore the source record for details and available documents.
A double-blind controlled trial of a 14-valent pneumococcal polysaccharide vaccine was carried out in 11 958 adults at Tari in the Papua New Guinea Highlands. Pneumococcal infection, confirmed by blood-culture and lung aspirate, was less in the vaccinated group by 84%. Mortality from pneumonia was less by 44%.
Explore the source record for details and available documents.
Novikoff rat hepatoma cells were propagated in suspension cultures containing 0.5 to 10 muC of 3H-methyl-thymidine, 3H-5-uridine, 3H-G-adenosine or 3H-8-adenine. The presence of the 3H-labeled precursors caused an inhibition of cell replication which was due to a delay or arrest of the cells in G2 and M. The degree of inhibition was proportional to the amount of radioactivity incorporated into nucleic acids. Almost immediate and complete inhibition resulted from incubation with 10 muC 3H-thymidine/ml. The presence of 0.5 muC 3H-thmidine/ml caused a significant increase in the relative proportion of cells in G2+M, even though the population doubling time of the culture appeared to be unaltered.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Diverticulitis is a disease affecting patients in the fifth to sixth decades. The charts of 12 patients with cesicocolonic fistulas secondary to diverticulitis were reviewed. Their presentation was primarily urological with pneumaturia present in 10 of 12 patients and fecaluria present in 5 of 12. The process of fistulization occurs in stages. If the incipient stage can be identified early fistulization can be prevented and the morbidity and mortality rates will be reduced significantly. In older patients with bladder irritation (with or without positive urine cultures) a high degree of suspicion for diverticular disease will ensure an accurate diagnosis earlier. Patients with penumaturia or fecaluria present less of a diagnostic challenge. Cystoscopy is a reliable procedure and we recommend its use in discovering a vesicocolonic fistula. Surgical therapy should be individualized for each patient and good results were obtained with primary resection as well as staged repair.
Sixteen patients with severe peptic stricture of the oesophagus were treated by oesophagogastrostomy at the Royal Children's Hospital, Melbourne, during the period 1948 to 1968. It has been possible to obtain a follow up on all patients, so that the period of follow up has varied from seven to 24 years. Although the early postoperative results were promising, later problems occurred in over half of the patients, the major complication being recurrence of peptic stricture at the anastomotic site.