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Biomedical subjects

J Donohue

Publications and source records attributed to J Donohue.

At least 19 recordsLinked to original sources
PubMed1992

Clonal analysis of myelodysplastic syndrome: monosomy 7 is expressed in the myeloid lineage, but not in the lymphoid lineage as detected by fluorescent in situ hybridization.

Conflicting results have been published on whether or not myelodysplastic syndromes (MDS) affect all cell lineages. Involvement of myeloid and erythroid cell lineages has been regularly observed, but it remains controversial whether the different lymphoid cell lineages are involved. In this study of eight patients with MDS associated with monosomy 7, fluorescent in situ hybridization (FISH) was used to enumerate the chromosomes 7 in interphase cells. With the probe D7Z1, the rate of false-positive detection of monosomy 7 was 3% +/- 2% in normal cells. T- and B-cell lines were established from eight patients with MDS and monosomy 7. As determined by FISH in interphase cells, 1.9% (0% to 3%) of the cells in the B-cell lines showed one fluorescent spot and 1.1% (0% to 2.9%) of the cells in the T-cell lines. These values do not differ from normal values. However, the possibility that normal cells were selected when the T- and B-cell lines were established could not be excluded. Therefore, peripheral blood cells were obtained, separated according to surface markers specific for lymphoid and myeloid cell lineage with a cell sorter, and analyzed for the expression of monosomy 7 by FISH. Antibodies recognizing T cells (CD3), B cells (CD20), natural killer (NK) cells (CD57), monocytes and granulocytes (low and high expression of CD11b antigen), and myeloid progenitors (CD33) were used to separate cells. The expression of monosomy 7 in the T cells, NK cells, and B cells did not differ from control values. These results in the lymphoid subpopulations are in stark contrast with the observations in the myeloid populations; the percentage of cells with monosomy 7 ranged from 9% to 78% (controls: 6% +/- 2%) in cells with low CD11b expression, 20% to 89% in cells with a high expression of the CD11b antigen (controls: 7% +/- 3%), and 23% to 91% in the CD33 positive cells (controls: 5% +/- 3%). The results of this study suggest that monosomy 7 does not usually affect lymphoid subpopulations but is restricted to committed progenitor cells with the capacity to differentiate into mature myeloid cells.

Adolescent↗
PubMed1992

Heteroconjugated antibodies enhance lymphocyte-mediated tumour cell lysis in vitro and in vivo.

Covalent linkage of an antitumour antibody specific for a tumour cell surface antigen to an antilymphocyte antibody specific for the T lymphocyte receptor complex produces a heteroconjugated antibody that can activate and redirect cytotoxic T lymphocytes to lyse tumour cells. The ability of an antilymphocyte-antitumour heteroconjugate (500A2 x 96.5) to direct the lysis of murine melanoma cells by cultured murine lymphocytes was tested in vitro using a 4-h chromium release assay and in vivo with a tumour neutralization assay. In vitro, the addition of heteroconjugated antibody significantly increased tumour lysis by murine C3H/HeN lymphocytes (median specific lysis 82.7 per cent with lymphocytes plus heteroconjugate versus 9.5 per cent for lymphocytes alone, P less than 0.001). In vivo, treatment with heteroconjugated antibody plus lymphocytes significantly reduced the development of pulmonary metastases after intravenous tumour administration (median number of pulmonary metastases 28.5 for combined treatment versus 250 for heteroconjugate or lymphocytes alone, P less than 0.001).

Animals↗
PubMed1990

Heteroconjugate antibody-directed killing of autologous human renal carcinoma cells by in vitro-activated lymphocytes.

Tumor cell lysis can be enhanced significantly in vitro when heteroconjugate (HC) antibodies (anti-CD3 x anti-tumor mAb) are used to specifically direct lymphocyte effector cells to the tumor cell target. In order to effectively utilize HC antibodies in an immunotherapy protocol, methods must be identified for the optimum expansion, activation, and retargeting of lymphocyte-effector populations from cancer patients. In this study, we have compared the proliferative responses of different normal and renal cell carcinoma (RCC) patient lymphocyte preparations (PBL, tumor-infiltrating lymphocytes) stimulated in vitro for periods up to 12 days with a variety of growth factor combinations (anti-CD3, rIL-2, rIL-4). These activated lymphocyte preparations were then tested in vitro for their ability to kill RCC tumor cells and tumor cell lines in the presence of HC preparations (anti-CD3 mAb covalently linked to mAb reactive to different RCC tumor-associated Ag). RCC patient PBL cultured with anti-CD3 plus rIL-2 for 12 days resulted in a 3- to 160-fold expansion of effector cells. These cells, as well as tumor infiltrating lymphocytes, when retargeted with appropriate HC antibodies were capable of mediating high levels of killing of autologous tumor cells. No constitutive autologous anti-tumor cell response was detected in the absence of added HC antibodies. Of the five anti-RCC mAb tested (A6H, K29, K20, UR07, and URO 3), HC containing URO 3 x anti-CD3 and K20 x anti-CD3 elicited the highest level of tumor cell lysis by the activated lymphocyte effector cells. Together these results demonstrate that HC antibodies may be a useful imunotherapeutic reagent for directing the killing of RCC tumor cells by autologous lymphocytes.

Antibodies, Neoplasm↗
PubMed1990

The pharmacokinetics of dilevalol in renal impairment.

Dilevalol, 200 mg, was administered orally as seven daily doses to three groups of six participants, with differing degrees of renal impairment. Values of Cmax, Tmax, half-life or renal elimination did not significantly change with decreased renal function. Values of area under the plasma concentration-time curves and pre-dose concentrations tended to increase with renal impairment and there was a significant, if small, correlation between these and glomerular filtration rate. The practical clinical consequences of these results is that impairment is not likely to be associated with significant accumulation of dilevalol.

Administration, Oral↗
PubMed1989

Pharmacokinetics of amlodipine in renal impairment.

Amlodipine was administered as 14 single 5-mg oral daily doses to 27 male subjects with renal function ranging from normal to haemodialysis-dependent. Blood specimens were obtained for measurement of plasma amlodipine concentrations for 24 h following the first dose, for 168 h following the final dose and during daily administration of amlodipine. Amlodipine was well tolerated. Renal impairment had little effect on the pharmacokinetics of amlodipine. The elimination half-life was of the order of 50 h, similar to previously reported values and did not vary with renal function. Steady-state pre-dose concentrations were observed after the ninth dose. Accumulation of amlodipine was not significantly different from that expected on theoretical grounds and did not significantly change with renal function. These results suggest that once daily administration of amlodipine is suitable for all degrees of renal function and that dosage adjustment is not necessary in renal impairment.

Adult↗
PubMed1989

A longitudinal study of the contribution of dental experience to dental anxiety in children between 9 and 12 years of age.

Dental records of a group of children of both sexes were examined systematically over a period of 3 years to determine if the quantity and quality of their dental experience would be associated with increases in dental anxiety. The study was a follow-up of an earlier cross-sectional survey in which older children had demonstrated increases in dental anxiety with age. According to the evidence obtained from their dental records, the children were divided into four groups depending on their patterns of attendance (regular/irregular) and whether or not they had received invasive treatment. The results indicated that children who did not receive invasive treatment during the period under scrutiny were significantly more anxious than those who had. On the other hand, the dental anxiety of children who attended regularly and received invasive treatment did not change significantly. This applied to boys and girls alike.

Age Factors↗
PubMed1989

Enzyme immunoassay system for panel testing.

An immunoassay system based on enzyme immunoassay technology has been developed for quantitative panel testing. The system includes test card disposables, reagents, and an instrument. Patients' samples are processed semiautomatically in the instrument with minimum user intervention. The test card has multiple test areas at individual locations on a membrane solid phase so that simultaneous determinations from a single specimen are possible. Each panel also includes positive and negative reagent procedural controls. Factory-determined calibration curves for each analyte are provided in barcode form with each test kit. The reagents include a specimen dilution buffer, enzyme conjugate, and precipitogenic substrate. Up to 10 test cards at a time can be processed in random-access and continuous-access modes, with automated agitation of sample and reagents over the solid phase, temperature-controlled incubation, and membrane washing and reading, data reduction, and printout of results. The optical reader measures diffuse reflectance and features source intensity and wavelength compensation.

Chemistry, Clinical↗
PubMed1986

Pharmacokinetics of enalapril in normal subjects and patients with renal impairment.

The pharmacokinetics of enalaprilat were studied after administration of single and multiple doses of enalapril maleate to people with normal and impaired renal function. Renal impairment was associated with higher serum concentrations of enalaprilat, longer times to peak concentrations, slower decline of serum concentrations and with reduced urinary elimination. Urinary elimination of enalaprilat was closely related to renal function. In patients with severe renal impairment (GFR values below 30 ml min-1 1.73 m-2) significantly smaller doses of enalapril maleate will be required than in patients with normal or less severely impaired renal function.

Adult↗
PubMed1977

Cis-diamminedichloroplatinum, vinblastine, and bleomycin combination chemotherapy in disseminated testicular cancer.

Fifty patients with disseminated testicular cancer were treated with a three-drug combination consisting of cis-diamminedichloroplatinum, vinblastine, and bleomycin. Three patients were considered inevaluable due to early death. This chemotherapy regimen produced 74% complete and 26% partial remissions. Furthermore, five patients with partial remission became disease-free after surgical removal of residual disease, producing an overall 85% disease-free status. Toxicity, although significant during remission induction with cis-platinum, vinblastine, and bleomycin, was usually manageable, although there were two drug-related deaths during this period. Thirty-eight of these patients remain alive and 32 remain alive and disease-free at 6 + to 30 + months. We believe this regimen represents a major advance in the management of patients with disseminated testicular cancer.

Adolescent↗
PubMed1975

Improved radioimmunoassay of plasm cortisol.

We report a simplified radioimmunoassay procedure for determination of plasma cortisol. The method offers the advantage that tracer, antibody, and assay buffer are added in a single step with the use of semi-automated equipment. Thus, critical pipetting procedures are minimized, and assay time is reduced to 4 h. No prior extraction or chromatographic purification of cortisol is required. The procedure is simple, reliable, and accurate. For either between-assay or within-assay determinations, the coefficients of variation are about 6%. Our results compare well with those obtained from a procedure that included extraction and chromatographic purification of cortisol in several plasma samples. Conditions for optimizing the assay are also discussed.

Autoanalysis↗