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Biomedical subjects

R H Connors

Publications and source records attributed to R H Connors.

26 records · Page 2Linked to original sources
PubMed1987

The effects of perfluorochemicals on tumor growth and chemotherapy response.

Hypoxia, leading to cells in resting or slow replication phases may be a cause of chemotherapy and radiation therapy resistance in some tumors. Perfluorochemicals (PFC) may potentiate response to these therapies by increasing oxygen delivery to the tumor, forcing cells into more therapy-responsive replicating phases. To assess the effects of PFC on tumor growth and chemotherapy response, 91 ACI rats bearing 1 cc flank Morris hepatoma tumors were divided into groups: Group I, control; Group II, Adriamycin (ADR) 10 mg/kg intraperitoneally (IP); Group III, Cytoxan (CTX) 100 mg/kg IP; Group IV, PFC 20 mL/kg IV; Group V, ADR and PFC; Group VI, CTX and PFC. Animals were kept in 0.5 FiO2 for 24 hours after treatment, and mortality and tumor volumes determined 2 weeks later. Tumor DNA turnover was measured using opposing pathways assay of 14C-thymidine uptake and degradation. In a separate group, tumor tissue pO2 was measured polarographically with an oxygen microelectrode before and after injection of PFC (20 mL/kg). The survival was significantly reduced in group IV (4%) compared with group I, control (73%). Both ADR and CTX slowed the growth of the tumor, while PFC alone significantly accelerated tumor growth. The tumor response to ADR was potentiated by the addition of PFC. These results were confirmed by DNA synthesis evaluation. The mean pO2 level prior to injection was 6.6 +/- 1.96 mmHg compared with 18.92 +/- 1.00 mmHg after PFC injection (P less than or equal to .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Operative technique and results of subtotal splenectomy for Gaucher disease.

Patients with type 1 (adult form) Gaucher disease complicated by massive splenomegaly and hypersplenism have previously been treated by total splenectomy. Subtotal splenectomy in Gaucher disease will retain splenic tissue which may protect the patient from the risk of overwhelming sepsis. Removal of at least 85 per cent of the splenic mass is necessary to eliminate hypersplenism and to decrease splenic size. The surgical technique and outcome of four patients undergoing subtotal splenectomy for massive splenomegaly due to type 1 Gaucher disease are discussed.

Adult↗
PubMed1980

Corticosteroid therapy in hemorrhagic and septic shock in puppies.

The efficacy of corticosteroid therapy in the treatment of shock remains controversial. In order to evaluate this question, the following controlled experimental study was undertaken. There were 44 puppies (2-6 kg) used to examine the effects of methylprednisolone (30 mg/kg) in both hemorrhagic and live Escherichia coli septic shock. In order to isolate the effects of steroid treatment, no volume or antibiotic therapy was given. Arterial, venous, and pulmonary artery catheterization allowed continuous hemodynamic and metabolic monitoring. One control group received steroid treatment and was not subjected to shock. Septic shock was achieved by a rapid bolus infusion of 10(9) live E. coli organisms. Hemorrhagic shock was produced by bleeding the puppy an average of 43% of his blood volume. Four septic and four hemorrhagic shock groups received either no treatment, steroids at the time of shock, or steroids 30 min before or after shock. Cardiac outputs of less than 50% of control values and significant lactic acidosis were documented in all of the shock animals. The septic groups showed more profound alterations in these parameters and a decreased overall survival. No statistically significant differences could be found, however, in the hemodynamic, metabolic or survival figures among the different septic shock groups, or among the various hemorrhagic shock animals. The anticipated preservation of cardiac output and decrease in leakage of lysosomal acid phosphatase were not seen with any treatment schedule. The theoretical benefits of corticosteroid treatment in shock could not be documented in these two models of severe septic and hemorrhagic shock in puppies.

Acid Phosphatase↗
PubMedDate not supplied

Pediatric TPN: efficacy and toxicity of a new fat emulsion.

Fat emulsions are particularly valuable in pediatric total parenteral nutrition (TPN) because they provide an isotonic solution rich in calories. Little is known about the ideal composition of fatty acid emulsions, however, and very few formulations are commercially available. A new fat emulsion using a safflower oil base has recently been approved. We have used this new emulsion to provide a significant percentage of the nonprotein caloric requirements (24 to 42%) in 4 patients requiring TPN. These patients ranged in age from 1 to 15 years and received no enteral nutrition during the 3-week course of the study. Nutritional improvement without major toxic effects was documented in each patient.

Adolescent↗