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Biomedical subjects

R J Ross

Publications and source records attributed to R J Ross.

At least 145 records · Page 8Linked to original sources
PubMed1982

Phospholipid-nucleoside conjugates. 3. Syntheses and preliminary biological evaluation of 1-beta-D-arabinofuranosylcytosine 5'-monophosphate-L-1,2-dipalmitin and selected 1-beta-D-arabinofuranosylcytosine 5-diphosphate-L-1,2-diacylglycerols.

Several new phospholipid-ara-C conjugates have been prepared and tested as prodrugs of the parent ara-C. The new derivative include ara-CMP-L-dipalmitin, ara-CDP-L-distearin, ara-CDP-L dimyristin, ara-CDP-L-diolein, and the radioactively labeled derivative ara-CDP-L-di[1-14C]palmitin. In addition, the unusually stable ara-CMP-L-dipalmitin-N-phosphoryldicyclohexylurea adduct was isolated as a crystalline solid (two diastereomers) in the reaction sequence to prepare ara-CMP-L-dipalmitin. The new prodrugs were solubilized by sonication methods and tested for their antiproliferative activity in vitro against mouse myeloma MPC-11 cells and against L1210 lymphoid leukemia. Such studies demonstrated that the antiproliferative activities of the prodrugs (as determined by ED50) were less that ara-C on a molar basis. In the mouse myeloma cell line some evidence was obtained that the antiproliferative activity was related to the chain length of the fatty acid side chains in the prodrugs. In in vivo studies against L1210 lymphoid leukemia in mice, the prodrugs were shown to be much more effective than ara-C, with the overall efficacy apparently being independent of the length of the fatty acid side chain. Some evidence was obtained in the vivo studies that the ara-CDP-L-dimyristin, which bears the shortest fatty acid side chain, was more toxic at the higher dosages than the longer chain length derivatives.

Animals↗
PubMed1982

Altered hydroxydesipramine concentrations in elderly depressed patients.

Recent reports demonstrate that hydroxy metabolites of desipramine (DMI) have pharmacologic activity and do not just produce side effects. In patients treated with DMI, we determined the ratio of 2-hydroxydesipramine (2-OH-DMI) to drug at steady state. The ratios in the elderly patients were higher than in younger patients, and whereas plasma levels of 2-OH-DMI increased with age, urinary clearances decreased. The known decrease in glomerular filtration with age may explain the selective increase of 2-OH-DMI concentration in the elderly.

Adult↗
PubMed1982

Nuclear magnetic resonance imaging and evaluation of human breast tissue: preliminary clinical trials.

In vivo clinical evaluations of human mammary tissue, including normal, dysplastic, and neoplastic breasts, were initiated using the FONAR method of nuclear magnetic resonance (NMR) imaging. Spin-lattice relaxation times (T1) were determined and correlated with other diagnostic modalities including mammography, xeroradiography, and sonography. Normal breasts and breasts with extensive fatty replacement were found to have the lowest T1 values, whereas T1 values of malignant tissue were elevated. T1 values for mammary dysplasia extended over a wide range, and NMR images exhibited lower proton density than normal tissue. In several patients with severely dysplastic breasts, T1 values overlapped those from patients with documented breast neoplasms. Markedly elevated T1 values were obtained from fluid-filled cysts that were well beyond the range of malignancy.

Breast↗
PubMed1982

Conversion from intravenous to oral dosing using sustained-release theophylline tablets.

Theophylline total body clearance was determined in asthmatic patients, from steady-state serum theophylline concentrations, measured during a constant-rate, intravenous aminophylline infusion. Theo-Dur dosing rates were calculated from the product of theophylline total body clearance and the desired steady-state theophylline concentration. After stopping the aminophylline infusion, oral doses of Theo-Dur were given every 12 hours. Blood samples were obtained 1, 3, 6,9, and 12 hours after the first oral dose and 12 hours after the second oral dose. Patients were evaluated for compliance and theophylline toxicity after receiving Theo-Dur for one week. Total body clearances and theophylline dosing rates varied more than threefold. The difference between the intravenous steady-state serum concentration and the average oral serum concentration was 1.2 micrograms/ml in patients with similar oral and intravenous dosing rates. The difference between peak and trough serum theophylline concentrations after the first oral dose averaged 7.8 micrograms/ml. Eight of nine patients evaluated after leaving the hospital were compliant, as determined from a tablet count during a clinic visit. Serum theophylline concentrations, determined 12 hours after the last Theo-Dur dose, averaged 10.4 micrograms/ml for the compliant patients.

Administration, Oral↗
PubMed1981

Concentrations of desipramine in elderly women.

Seven elderly depressed women were given desipramine, and plasma concentrations of the drug were measured from blood samples drawn after a single dose and during long-term use. The concentrations were no different from those found in younger patients. Aging does not seem to alter the plasma concentration of desipramine, and the authors conclude that the increased incidence and severity of the drug's side effects are probably not due to high drug concentrations.

Aged↗
PubMed1980

Priapism: review of simple surgical procedure.

For the surgical treatment of priapism we have created a percutaneous fistula between the glans penis and the corpus cavernosum with good results. This is our preferred method of management for all patients except those undergoing sickle cell crisis.

Adult↗
PubMed1980

The wandering spleen in infancy and childhood.

The wandering spleen is an unusual entity, which has been described rarely in infants and children. Although patients may be asymptomatic, some may present with torsion of the spleen with associated vovulus and vascular infarcation. Two asymptomatic patients with wandering spleen are described. Radiographic signs and isotopic scan findings of wandering spleen are discussed and the literature is reviewed.

Child↗
PubMed1978

Computed tomography in a private practice office.

Since 1975, the author examined over 6,000 outpatient and hospital inpatients with computed tomography in a private practice CT office. The patients were referred by 368 physicians and 26 hospitals. A CT center in a private radiology office available for immediate utilization by several hospitals and many physicians is an effective method of controlling costs and containing unnecessary capital equipment expenditures, and contributes to the preservation of the private practice of radiology and medicine.

Adolescent↗
PubMed1978

Developing role of sensorimotor cortex and pyramidal tract neurons in contact placing in kittens.

Unilateral or bilateral removal of kitten sensorimotor (SM) cortex prior to the fourth postnatal week was followed by recovery of contact placing (CP) to stimulation of any of the four forepaw cutaneous fields. However, immediately after a removal under ethyl chloride, CP was depressed contralaterally, especially to lateral stimulation (lateral CP). When the operated kitten aged to 5--9 weeks, the likelihood of CP secondarily declined contralateral to the SM cortical extirpation, but was restored by administration of d-amphetamine. An initial extirpation after the fifth postnatal week was followed by a severe deficit in CP. 2. Cooling the SM cortex, internal capsule or bulbar pyramid during the 2nd and 3rd week was followed by reversible, contralateral loss of lateral CP, extension of the forelimb and, later, by reduced movements. Lateral CPs were often hypermetric prior to loss. By contrast, cooling SM cortex in the first week was usually ineffective. Thus, during the 2nd week, lateral CP developed a dependence on SM cortex, and in particular on PT neurons. 3. After a delay usually of 1 or more min, cooling the SM cortex reduced the resting discharge of individual neurons in buried motor cortex; the antidromic conduction time in PT neurons was significantly increased and the spike height was reduced.

Animals↗
PubMed1977

Plaque of multiple sclerosis seen on computerized transaxial tomogram.

The spectrum of computerized transaxial tomographic lesions in multiple sclerosis is not yet known. Low density lesions have been reported. We are reporting contrast enhanced lesions, occurring at different times and neurologic sites in a patient with multiple sclerosis. Such CT lesions might be of diagnostic significance.

Adolescent↗
PubMed1975

Area Health Education Centers: what are they and where are they going?

Area Health Education Centers (AHECs) were one of the recommendations arising from the 1970 report of the Carnegie Commission on Higher Education, Higher Education and the Nation's Health: Policies for Medical and Dental Education. Subsequently, three separate federal programs were implemented. Since issuance of the commission's report, major changes have occurred in the health field. Many of the assumptions and predictions prevailing at the time of the report are now being questioned, leading to a need to reassess the policies underlying the AHEC concept. Enough time has elapsed that the AHEC programs can be evaluated in terms of the policies leading to their original recommendation, but they are still embryonic and diverse enough that they have not themselves become fixed policy. It is crucial at this stage of their development that the programs be assessed not only in relationship to each other but also in the context of the other programs and policies which together with AHECs presently comprise our unplanned national health strategy.

Delivery of Health Care↗