PubMed Health⌕ Search

Biomedical subjects

R Lynch

Publications and source records attributed to R Lynch.

At least 55 records · Page 3Linked to original sources

Cerebral NMR imaging: early results with a 0.12 T resistive system.

Over a 6-month period, 157 patients, 89 of whom had central nervous system tumors, were examined on a prototype 0.12 T resistive nuclear magnetic resonance (NMR) imaging unit. All of the patients had computed tomography (CT), which was used as a standard to which the NMR findings were compared. Studies were done primarily by saturation-recovery technique with short repetition times. The signal intensity with saturation-recovery technique did not allow differentiation among most tumor types. Location, extent, and morphology helped to some extent in attempts at differentiation. In the multiplanar mode, NMR compared favorably to CT with regard to lesion detection. Limited early experience suggests that NMR also may detect some lesions when the CT is negative and may detect additional lesions when one or more are present. The NMR examination was well tolerated by selected patients.

Adolescent↗

Growth characteristics of MOPC-315 plasmacytoma and response to anticancer agents.

We examined the growth characteristics and response to anticancer agents of the murine plasmacytoma MOPC-315, a rapidly growing and widely disseminating tumor syngeneic in BALB/c mice. The doubling time for the tumor was approximately 24 hours, and about 1 in 100 cells was tumorigenic. We developed a spleen colony assay for the clonogenic component of the tumor and used it to define the dose-response relationships for various anticancer agents, including melphalan, cyclophosphamide, 1,3-bis(chloroethyl)-1-nitrosourea, 5-fluouracil, gamma-radiation, methotrexate, methylprednisolone, cytosine arabinoside, and vincristine.

Animals↗

Evaluation of three dry-sterilized hollow fiber artifical kidneys.

We investigated three new dry sterilized hollow fiber artificial kidneys (HFAK) (Cordis Dow CDAK 1.3, Travenol CF 1200, Extracorporeal Tri-Ex 1). Dry sterilization makes these dialyzers more economical by shortening set-up time. Dry sterilization also eliminates iatrogenic administration of residual sterilant. Water of imbibition can significantly increase the blood compartment volume of the dialyzer during dialysis. Consequently, a corrected blood volume for each dialyzer was established; these corrected volumes varied from 13--36% greater than the volume determined before dialysate flow. With low dose heparinization of these dialyzers there was between an 18 and 45% decrease in the post dialysis volume, presumably due to fiber clotting during dialysis. This volume added to the residual blood loss measured by a colorimetric technique accounted for a possible blood loss ranging between 26.9 and 53.9 ml per dialysis for these three dialyzers. Our results suggest that a relationship between dialyzer clotting and decreased dialyzer efficiency may exist. These three capillary flow dialyzers had a much lower platelet drop (0--9% pre to post) when compared to 30--40% drop of flat plate dialyzers. These dialyzers were found to be safe and easy to use but the high fiber clotting warrants further investigation in chronic dialysis patients on high dose heparin.

Kidneys, Artificial↗

Growth and rejection of leukemia cells in individual mice after combined treatment with amphotericin B and 1,3-bis(2-chloroethyl)-1-nitrosourea.

We assayed the femoral marrows of individual AKR mice for leukemia colony-units (LCFU) after treatment with amphotericin B (AmB) and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) or with BCNU alone. No differences between the groups were noted in the first 7 days after treatment. All the mice treated with BCNU alone were dead by day 8, and all the survivors among the animals receiving AmB and BCNU retained high levels of LCFU for 2 more days; these LCFU were subsequently rejected by the host. By day 12, LCFU were undetectable. Histologic examination of organs from the same mice on day 5 showed fewer leukemia cells in the mice treated with the combination of agents. In all treatment groups, mice dying of leukemia early (by day 9) had systemic leukemia and most had central nervous system (CNS) involvement. All animals dying between days 10 and 14 had CNS leukemia, but few had systemic leukemia; at later times, though few animals died, they invariably had CNS leukemia without systemic involvement.

Amphotericin B↗

Protective effects of amphotericin B against spontaneous and transplantable murine tumors.

Two tumor systems were used to test prophylactic effects of amphotericin B (AmB). When 0.5 mg AmB was given ip every 2 weeks to AKR mice beginning at 8 weeks of age, the 50% tumor incidence for spontaneous lymphoma development was delayed 2-3 months. In the second tumor system, BALB/c mice received injections of either 20 or 50 mug AmB before receiving MOPC-315-C cells sc. The mice given the low dose of AmB demonstrated a decreased tumor incidence and a reduced tumor growth rate, when compared with controls. Opposite effects were found for the group administered the high dose; tumor incidence and rate of growth were increased.

Adjuvants, Immunologic↗