Biomedical subjects

J M Parks

Publications and source records attributed to J M Parks.

6 recordsLinked to original sources

PubMed1991

Urokinase binding and receptor identification in cultured endothelial cells.

Recombinant human single-chain urokinase (rscu-PA), two-chain urokinase (tcu-PA), and diisopropyl-fluorophosphate-treated tcu-PA (DFP-tcu-PA) bound to cultured human and porcine endothelial cells in a rapid, saturable, dose-dependent and reversible manner. Analysis of specific binding results in cultured human umbilical vein endothelial cells (HUVECs) gave the following estimated values for Kd and Bmax: 0.57 +/- 0.08 nM (mean +/- S.E.) and 188,000 +/- 18,000 sites/cell for 125I-labeled rscu-PA; 0.54 +/- 0.10 nM and 132,000 +/- 23,900 sites/cells for 125I-labeled tcu-PA; 0.89 +/- 0.14 nM and 143,000 +/- 30,300 sites/cell for 125I-labeled DFP-tcu-PA, respectively. Values for Kd were similar for primary and subcultured (six passages) HUVECs, but Bmax values were lower in subcultured HUVECs. Similar Kd values were found in cultured porcine endothelial cells; however, Bmax values varied depending on the endothelial cell type. All 125I-labeled urokinase forms yielded similar cross-linked approximately 110-kDa ligand-receptor complexes with cultured HUVECs, and 125I-labeled DFP-tcu-PA bound to a single major approximately 55-kDa protein in whole-cell lysates (ligand blotting/autoradiography), suggesting the presence of a single major approximately 55-kDa urokinase receptor in cultured HUVECs. The approximately 55-kDa urokinase receptor, isolated from several separate batches of cultured HUVECs (3-5 micrograms of protein, approximately 1 x 10(9) cells), by ligand affinity chromatography, exhibited the following properties: retained biologic activity as evidenced by its ability to bind 125I-labeled rscu-PA by ligand blotting/autoradiography and formation of a cross-linked 125I-labeled approximately 110-kDa rscu-PA-receptor complex; single-chain approximately 55-kDa protein, following reduction; complete conversion to and formation of a single major deglycosylated approximately 35-kDa protein, following treatment with N-glycanase.

Animals↗

PubMed1990

Disseminated histoplasmosis in patients with AIDS.

Disseminated histoplasmosis was diagnosed in 36 (4%) of 980 patients with AIDS seen at Parkland Memorial Hospital in Dallas, Texas before September 30, 1989. Diagnostic sensitivity of blood culture plus examination of peripheral smear was 88%; sensitivity of bone marrow aspiration and blood culture was 80%. Median CD4 lymphocyte count at diagnosis was 33/cu mm. Median actuarial survival from the date histoplasmosis was diagnosed was 188 days. Thirteen (36%) of the 36 patients died before adequate antifungal therapy could be administered, while 13 survived long enough to receive 1,500 mg of amphotericin B; actuarial survival of the latter group from the date 1,500 mg of amphotericin B had been infused was 47% at 1 year. The substantial early mortality of AIDS-associated disseminated histoplasmosis and the modestly encouraging survival of those who were diagnosed in time to receive adequate therapy raise the issues of surveillance, prophylaxis, and empiric therapy for this infection in selected HIV-positive patients.

Acquired Immunodeficiency Syndrome↗

PubMed1989

Cocaine-associated rhabdomyolysis.

Three male patients developed a total of four episodes of acute rhabdomyolysis associated with documented cocaine intoxication (two caused "crack" and two caused by intravenous cocaine). Included is one patient who developed rhabdomyolysis after injecting cocaine and then redeveloped it 6 months later on "rechallenge." One of the four cases resulted in death related to severe hyperkalemia and ischemic bowel. The remaining three episodes followed a course of nonoliguric renal failure.

Acute Disease↗

PubMed1976

Cell volume and permeability of oxygen-and glucose-deprived retina in vitro.

Rabbit retina was deprived of O(2) and glucose in vitro for up to four hours at 37 C. Intracellular volume was measured, using inulin as an extracellular marker. After a 30-minute latency, cells swelled rapidly to more than twice normal volume while extracellular volume was unchanged. Intracellular accumulation of water was not reversed by resupply of oxygen and glucose. Permeability to small molecules was assessed with mannitol. The ratio of mannitol space to inulin space averaged 1.0 in controls. This ratio remained 1.0 up to 30 minutes of deprivation, but increased to 1.2 by 60 minutes. Permeability to large molecules was assessed from the rate of loss of isotopically labeled cell protein into the medium. There was no difference between control and deprived retinas up to three hours.

Animals↗

PubMed1966

Keeping current.

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Education, Medical, Continuing↗

PubMedDate not supplied

Mycobacterium kansasii infections in patients positive for human immunodeficiency virus.

The experience with Mycobacterium kansasii infections in patients who are infected with human immunodeficiency virus (HIV) at Parkland Memorial Hospital in Dallas is presented, and the literature on such infections is reviewed. The absolute and relative paucity of reports of M. kansasii infections in HIV-positive patients is emphasized. M. kansasii infections in HIV-positive patients are classified as either pulmonary or disseminated. Evidence of the lack of therapeutic response in patients with disseminated infections and of the potential for therapeutic response in patients with infections limited to the lung is reviewed and documented. Other unresolved diagnostic and therapeutic issues concerning M. kansasii infections in HIV-positive patients are reviewed.

Adult↗