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Biomedical subjects

J Hines

Publications and source records attributed to J Hines.

At least 55 records · Page 3Linked to original sources

Stability of heroin hydrochloride in infusion devices and containers for intravenous administration.

The stability of heroin hydrochloride in various drug-administration devices was studied. Heroin hydrochloride was supplied as the bulk powder by the National Institute on Drug Abuse and in the formulated dosage form by Evans Medical, Ltd. Stability was determined at concentrations of 1 and 20 mg/mL at room temperature (23-25 degrees C) and at 4 degrees C in a polyvinyl chloride (PVC) bag, a disposable glass syringe, and two disposable infusion devices. Studies at both concentrations also were conducted at 31 degrees C in the disposable infusion devices. All experiments were conducted in triplicate. A validated, stability-indicating, high-performance liquid chromatography assay was used. Heroin hydrochloride remained stable for a minimum of 15 days in the PVC bag and the Infusor infusion device at the tested temperatures and concentrations. In the glass syringe, heroin hydrochloride was shown to be stable for a minimum of 15 days at both 1 mg/mL and 20 mg/mL if refrigerated at 4 degrees C, whereas at room temperature it was stable for a minimum of 7 days at 1 mg/mL and for 12 days at 20 mg/mL. In the Intermate 200 infusion device, heroin hydrochloride was stable for a minimum of 15 days at both concentrations and all temperatures except for the 1 mg/mL concentration at 31 degrees C. In the latter case, stability was for a minimum of two days. No substantial changes in physical appearance or pH were observed in any of the containers under the conditions studied. Heroin hydrochloride can be repackaged in the disposable glass syringe, PVC bag, and each of the disposable infusion devices for routine clinical use.

Chromatography, High Pressure Liquid↗

The development of alpha-emitting radionuclide lead 212 for the potential treatment of ovarian carcinoma.

alpha-Emitting radionuclides may be an effective alternative treatment against ovarian carcinoma because they have short half-lives and are densely ionizing, with high linear energy transfer to a depth of several cell diameters without requiring cellular oxygenation. One radionuclide that has been generated and tested in our laboratory in vitro and in vivo is lead 212 (212Pb). Intraperitoneal instillation of 212Pb prolonged survival and totally eradicated tumor in 24% of mice inoculated with the extremely virulent Ehrlich ascites-producing tumor. In vitro 212Pb was two to four times more effective in killing human ovarian cancer cells than x-rays. Irradiation with 212Pb increased the radiosensitivity and chromosomal aberrations of cells. In dogs, intraperitoneal instillation of 2.6 mCi of ferrous hydroxide tagged with 212Pb caused no significant toxicity. It appears that alpha-emitting radionucides such as 212Pb have the potential to be a new and potent treatment of ovarian carcinoma and could be effective in cases that are resistant to conventional chemotherapy or x-ray therapy.

Animals↗

Comparison of short-lived high-LET alpha-emitting radionuclides lead-212 and bismuth-212 to low-LET X-rays on ovarian carcinoma.

We are investigating the potential use of short-lived alpha-emitting radionuclides for the treatment of ovarian carcinoma. These radionuclides transfer dense high ionizing linear energy (high LET) over a short path length without dependence upon cellular oxygen. The alpha-emitting radionuclides chosen were lead-212 and bismuth-212 which are readily available. The radiosensitivities of two ovarian carcinoma cell lines (OVC-1 and OVC-2) was greater with 212Pb and 212Bi than with X-ray therapy. D0, inversely related to the radiosensitivity, was 155 and 240 rads for OVC-1 and OVC-2, respectively. With 212Pb or 212Bi, the slope of the survival curves was steeper. The D0 was 75 and 70 rads after 212Pb and 85 and 95 rads after 212Bi treatment for OVC-1 and OVC-2, respectively. The relative biological effectiveness with alpha irradiation was two to four times greater than with X rays. Unlike low-LET irradiation (i.e., X rays and gamma emitters) the cells had no ability to accumulate or repair sublethal damage. From these experiments it is concluded that a greater therapeutic advantage may be gained with alpha-emitting radionuclides than X rays. Further development of these nuclides may provide for a new form of therapy.

Bismuth↗

The effect of the alpha-emitting radionuclide lead-212 on human ovarian carcinoma: a potential new form of therapy.

To improve response and survival of patients with ovarian carcinoma noncross-resistant forms of therapy must be developed. alpha-emitting radionuclides may be therapeutically useful since they can directly ionize with energies of 5 to 9 MeV, penetrate only a few cell diameters, and transfer a high amount of energy. The purpose of this study was to determine the effect of the alpha-emitter, lead-212 (212Pb), complexed to sulfur in a nude athymic mouse model (NIH:OVCAR-3) containing human ascites and solid epithelial ovarian carcinoma. Thirty-six nude mice 28 to 32 days old were injected with 10(7) to 10(8) carcinoma cells from donor mice. After 4 weeks, six groups of six nu/nu athymic BALB-C mice were intraperitoneally injected with 70, 50, 20, 5 microCi of 212Pb sulfur colloid, sulfur colloid, or saline. Tumor necrosis with a decrease in ascites and a dose-related survival were noted with doses of 50, 20, and 5 microCi. With 70 microCi acute gastrointestinal toxicity developed. These experiments form the basis for further investigations and the development of alpha-emitting radiocolloids which may be of therapeutic efficacy in the treatment of intraperitoneal ovarian carcinoma.

Animals↗

Cardiovascular results from a rhesus monkey flown aboard the Cosmos 1514 spaceflight.

Pressure and flow relationships to the head were measured before and during spaceflight by means of a chronically implanted cuff placed about the left common carotid artery in one of two rhesus monkeys flown aboard Cosmos 1514. Measurements were obtained daily for 4 min every 2 h during the 5-d spaceflight and compared to identical recordings obtained during a 35-h pre-flight control period 9 d before flight and a 12-h period while on the launch pad. Mean arterial pressure demonstrated a 10% increase compared to control levels immediately on insertion into orbit and maintained a 16-27% increase over the first few hours of flight before returning to baseline levels. Blood flow velocity showed a marked increase (approximately 8 cm/s) compared to pre-flight control while on the launch pad which was maintained over the duration of the flight. Blood flow showed reciprocal changes to pressure on orbital insertion. Cardiovascular system changes persisted into the second day of flight and were most clearly indicated by a decrease in relative differences between blood flow to the head and total cardiac output as measured by impedance plethysmography. Signs of adaptation appeared on days 3-5 of flight.

Animals↗

Comparison of the membrane-related effects of cytarabine and other agents on model membranes.

UNLABELLED: The membrane-associated effects of a series of chemotherapeutic and other drugs were examined via differential scanning calorimetry and by their modulation of the action of porcine phospholipase A2 (PLA2) on bilayer substrates. The drugs examined included: cytarabine, amino-glycoside antibiotics, adriamycin, dibucaine, butacaine, and VP-16. The bilayers employed were phase-separated ternary lipid mixtures containing dimyristoylphosphatidylcholine: palmitoyllysolecithin: and either hexadecanoic acid (fatty acid ternary mixture) or hexadecanol (alcohol ternary mixture). Effects of the more hydrophilic drugs (cytarabine and aminoglycoside antibiotics) on the calorimetric profiles of the negatively charged (fatty acid-containing) and the neutral (hexadecanol-containing) ternary lipid mixtures indicate that the interaction of these drugs with biomembranes is likely to be dominated by electrostatic interactions. All of the drugs investigated, including the more hydrophobic adriamycin, dibucaine, butacaine, and VP-16, affected the phase equilibrium in the membrane and exhibited apparent noncompetitive inhibition of the action of PLA2 on bilayers composed of ternary lipid substrates. In addition, cytarabine inhibited fusion of fatty acid-containing ternary mixtures. CONCLUSIONS: These drug:membrane interactions leading to a shift in the phase equilibria were apparently regiospecific. Hydrophilic drug:membrane interactions included an important electrostatic component. The effects of all of the drugs employed in this study on the action of PLA2 on a bilayer substrate (fatty acid-containing ternary lipid mixture) are hypothesized to be a result of the drug-mediated shift in phase equilibria away from the optimally active phase distribution. As a result, PLA2 binds with normal affinity to the membrane, but its membrane substrate is not catalytically turned over. It is evident that these drugs can directly affect cellular homeostasis in a manner that can show a dependence on the nature of the membrane surface.

Anti-Bacterial Agents↗

Public awareness of physically disabled persons.

Promoting public awareness that disabled people can function independently within society is seen by many as a necessary precursor to widespread changes in accessibility, housing, and social and economic opportunities for physically disabled people. The goal of the present investigation was to empirically assess the effectiveness of a major Canadian publicity campaign which was designed to sensitize people to the needs and concerns of physically disabled people and to promote favorable attitude change. Results indicate that while the visibility of the publicity campaign can be considered a modest success, the campaign was ineffective in promoting positive attitude change. The implications of the findings for the integration of disabled people into the larger community are discussed.

Adolescent↗

A comparison of children's electric wheelchairs.

During the past few years, the Occupational Therapists at the Kitchener-Waterloo Rotary Children's Centre have explored and prescribed electric wheelchairs for handicapped children from 2-19 years of age. This paper presents a comparison of three children's electric wheelchairs, the Bec, Solo, and Everest and Jennings.

Adolescent↗

Parotid neoplasms: a report of 250 cases and review of the literature.

A 25-year experience with parotid tumors was reviewed. From a total of 250 neoplasms, 173 were histologically benign and 77 were malignant. Benign mixed tumors accounted for 59% of all lesions. Clinical parameters used to diagnose parotid neoplasms were found to be unreliable in determining whether a given tumor was benign or malignant. The mean age for malignant lesions was 10 years greater than for benign lesions. The phenomenon of malignant transformation of a benign tumor was considered in four patients. Complete surgical excision is the safest and preferred method for diagnosis. Preoperative needle or incisional biopsy are associated with a high degree of local recurrence. The appropriate management of any parotid tumor is predicated on special histological type. Local excision or enucleation no longer have a place in the surgical management of benign parotid tumors. Postoperative tumor recurrence and morbidity are directly related to awareness of surgical anatomy and pursuit of correct surgical techniques for adequate resection. The five-year recurrence rate for 102 benign mixed tumors was 6%. Recurrence in malignant tumors varied with specific histological types but was generally high. Five-year survival for all malignant parotid tumors was 48%.

Adolescent↗