Biomedical subjects
Publications and source records attributed to B Harrison.
This paper demonstrates the necessity of a team approach in complicated cases; introduces an inexpensive yet stable appliance for postsurgical intra-arch fixation; and warns of the dangers of rehabilitation before total temporomandibular joint resolution.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
alpha-Dimethyltyrosine induces a phenocopy of the body color mutant yellow when fed to larvae of Drosophila melanogaster. The compound also induces changes in male courtship behavior which are similar to the effects of the mutant gene.
XK469 (NSC 656889) is a water-soluble member of the novel quinoxaline family of antitumor agents. In vitro, XK469 demonstrated selective cytotoxicity for several murine solid tumors including colorectal and mammary adenocarcinoma cell lines, when compared to both leukemia and normal epithelial cells. In vivo, XK469 was active against 7/7 murine tumors tested, including pancreatic ductal carcinomas #02 and #03, colon adenocarcinomas #38 and #51/A, mammary adenocarcinoma #16/C and the Adriamycin resistant mammary adenocarcinomas #16/C/ADR and #17/ADR. XK469 was efficacious both intravenously and orally. Regardless of dosing schedule, conventional mice tolerated higher total doses than SCID or nu/nu mice did. Despite these reduced doses, XK469 was active against xenografts of 4/6 human tumor lines including mammary adenocarcinoma MX-1, the small cell lung cancer DMS 273, the prostate model LNCaP and the CNS tumor SF295. The lower doses in the xenograft studies were below curative levels. The dose-limiting toxicity appeared to be myelosuppression with rapid host recovery (5-8 days), and in vitro assays of XK469 toxicity to murine bone marrow neutrophil progenitors CFU-GM (colony forming unit-granulocyte/macrophage) demonstrated concentration-dependent toxicity from 0.5-30 microg/mL. The difference in drug tolerance between BDF1 and SCID mice was detected in vitro as a 3-fold difference in the IC90 for CFU-GM, despite similar IC50 values. Comparative in vitro hematotoxicology studies revealed that human bone marrow CFU-GM tolerated XK469 as well as their SCID counterparts (IC90 values 5.7 vs. 7.4 microg/mL). Based on comparison with previously tested anti-cancer agents, these data suggest that humans will be able to tolerate XK469 doses that are efficacious against human tumor xenografts.
Eight dogs, divided into two groups of four by varying pin rigidity, underwent 15% left tibial lengthening by the Ilizarov method. In group I, "tensioned" 1.6-mm wires maintained a rigidity approaching that of 4.0-mm pins. In group II, the wires, maintained at half the tension, averaged 45% of the rigidity measured in group I. All dogs in group I filled the experimental gap with de novo osteogenesis, whereas all of the dogs in group II prematurely bridged the gap, arresting the process of osteogenesis. From these experimental results, clinical trials have been started using commercially available external fixation devices utilizing pins with equivalent rigidity.
Explore the source record for details and available documents.
This article is an account of an incident at a special school, involving a pupil, a young teacher, and two senior members of staff. The article offers some reflections and conclusions on the special challenges to be faced when making relationships with the young. Reference is made to Winnicott, Lomas, Bridgeland et al, in suggesting connections between the insights and skills of both therapy and of teaching.
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.
The animal model developed in the Soviet Union by Ilizarov has been reliably reproduced by us for the mechanical induction of osteogenesis using slow distraction. Our preliminary studies in six adult dogs indicate that this osteogenesis originates from well-structured intramembranous ossification, with rapid maturation to lamellar bone, indistinguishable from surrounding host bone. Mineralization increases steadily, reaching critical levels for radiographic visualization between Days 21 and 28. In this model, the osteogenic area then exceeds normal bone density temporarily but returns to normal density within three months. Distraction for 28 consecutive days (at 0.25 millimeters every six hours using rigid transfixion wires, as Ilizarov describes) reliably lengthened the tibiae by 12 percent, increasing mass by 27 percent, and volume by 26 percent with only a one percent change in overall density. The process required four months to add 24 millimeters of mature, lamellar bone capable of full weight-bearing by the dogs. This rate of osteogenesis, estimated at 202 microns per day, is four times faster than a human's fastest growth plate (child's distal femur at 50 microns per day). Calcium/collagen ratios did not differ significantly from normal bone controls.
Explore the source record for details and available documents.
Explore the source record for details and available documents.