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Biomedical subjects

S Parker

Publications and source records attributed to S Parker.

At least 217 records · Page 12Linked to original sources
PubMed1981

Recurrent unilateral lung disease.

A 25-year-old patient, with multiple pulmonary metastases from osteogenic sarcoma who two years ago developed respiratory failure with unilateral left lung involvement and was successfully treated with independent lung ventilation, was readmitted to an ICU with recurrent unilateral lung disease. Conventional therapy failed to reverse the respiratory failure; independent ventilation temporarily improved the patient's oxygenation. At autopsy, different involvement of the two lungs by the tumor was evident so that blood flow of the right lung and lymphatic flow of the left lung were impaired. When respiratory failure unresponsive to conventional therapy develops, anatomical abnormalities should be considered.

Adult↗
PubMed1981

Dopamine administration in oliguria and oliguric renal failure.

Oliguric renal failure significanlty worsens the prognosis of many critical illnesses, particularly in patients with respiratory failure. In 52 patients, a continuous infusion of dopamine, 1.5-2.5 micrograms/kg . min, was administered when creatine clearance (Ccr) fell below 40 ml/min and urinary output was less than 1 ml/kg . h despite normal intravascular volume. In 18 patients, a continuous infusion of furosemide (3-5 mg/kg . day) was also administered. Daily, two 3-h collections of urine and blood specimens were obtained to determine Ccr, osmolar clearance (Cosm), free water clearance (CH2O) and excreted fraction of filtered sodium (FENa); one collection was made during dopamine infusion and one while the infusion was suspended. Cardiac output and pulmonary venous admixture were also measured. The authors obtained 199 urine collections in 52 patients; considering the aggregate patient pouplation, urinary output increased by 42.3% (30.2 +/- 3.45 (SEM) ml/h), on dopamine infusion. Cosm, FENa, and Ccr were also higher on dopamine. CH2O and hemodynamic variables were not altered by dopamine infusion. When patients were startified on the basis of mechanical ventilatory support, Ccr and furosemide administration, dopamine infusion essentially caused the same changes in the variables studied as described for the aggregate patient population. Diuresis and sodium excretion increased significantly on dopamine even in those patients receiving furosemide infusion. The authors conclude that fluid and osmolar load can be eliminated more effectively in critically ill patients with continuous infusion of 1.5-2.5 micrograms/kg . min of dopamine.

Anuria↗
PubMed1979

Sacral dermal sinus: A report of 3 cases.

Three cases of sacral dermal sinus are reported. Although none of the patients developed meningitis, the danger of this serious complication and the need for early diagnosis and surgical excision are emphasized. Invasive radiological investigations may be dangerous and are seldom indicated. The relationship of sacral dermal sinus to other dermal lesions in this area is discussed.

Child↗
PubMed1979

Factors influencing in vitro production of colony-stimulating factor by mononuclear leukocytes from humans.

The purpose of this study was to identify factors that influence the production of colony-stimulating factor by leukocytes of humans. The use of nonadherent light-density bone marrow cells is semisolid agar cultures to assay the concentrations of colony-stimulating factor in the supernatant of monocyte and mononuclear leukocyte cultures made it possible to distinguish between colony-stimulating factor, which stimulates colony-forming cells directly, and monocyte-dependent stimulating activity, which acts indirectly, by increasing the monocyte production of colony-stimulating factor. Colony-stimulating factor was not detectable in the cytosol of monocytes; that detected in culture must, therefore, have been newly synthesized. Synthesis was enhanced independently by heat-inactivated human serum and by semipurified serum fractions enriched with monocyte-dependent stimulating activity. The kinetics of the production of colony-stimulating factor in the presence and absence of monocyte-dependent stimulating activity indicated that the latter facilitated monocyte production of the former. Factors released from neutrophils were shown to reduce the production of colony-stimulating factor and thr proliferation of colony-forming cells and thus may provide a feedback control mechanism limiting the proliferation of neutrophils.

Colony-Stimulating Factors↗
PubMed1979

Imidoester inhibition of lymphocyte DNA synthesis.

Imidoesters amidinate free amino groups and produce inter- and intramolecular covalent bonds. To determine whether imidoesters influenced lymphocyte transformation, human peripheral blood or calf lymph node lymphocytes were cultured with dimethyladipimate (DMA), a bifunctional (cross-linking) imidoester, or methyl acetimidate (MAC), a monofunctional (noncross-linking) imidoester. Both DMA and MAC decreased the rate of endogenous DNA synthesis in a dose-dependent fashion. In further work, lymphocytes were treated with Phaseolus vulgaris phytohemagglutinin, concanavalin A, or periodate. DMA (1 mM) decreased DNA synthesis in P. vulgaris phytohemagglutinin-stimulated human cells by 65%, Concanavalin A-stimulated cells by 98.2%, and periodate-stimulated cells by 85%. Similar results were obtained with 1 mM MAC. Inhibition by DMA was slightly greater than was the inhibition by MAC. Decreased DNA synthesis resulted if DMA was added to P. vulgaris phytohemagglutinin-stimulated human lymphocytes at initiation of culture (72%) or after 16 hr (75%); inhibition was less when DMA was added after 24 hr (43%) and was not apparent if added after 48 hr. Therefore, both monofunctional and bifunctional imidoesters inhibit endogenous and stimulated DNA synthesis in human and calf lymphocytes.

Cells, Cultured↗
PubMed1978

Response bias in category and magnitude estimation of difference and similarity for loudness and pitch.

Interval scales of sensory magnitude were derived from magnitude and category estimates of loudness differences, loudness similarities, pitch differences, and pitch similarities. In each of the four loudness experiments, a loudness scale was constructed from a nonmetric analysis of the rank order of the judgments. The four loudness scales so constructed were found to be equivalent to one another and indicated that loudness was a power function of sound pressure with an exponent of .29. A similar analysis for the four pitch experiments found the pitch scales derived in each case to be equivalent to one another and linear with the mel scale of pitch. Thus the same sensory and similarities for two distinct perceptual continua. For both pitch and loudness, these sensory scales were used to generate scales of sensory differences. A comparison of the category and magnitude estimates of sensory differences with the scale of sensory differences derived from the nonmetric analyses indicated the presence of significant response biases in both category and magnitude estimation procedures.

Acoustic Stimulation↗
PubMed1978

An autoradiographic study of the afferent innervation of the trachea, syrinx and extrapulmonary primary bronchus of Gallus gallus domesticus.

A method for injecting a small quantity of tritiated leucine directly into the nodose ganglion of the adult hen is described. The presence of an inner and an outer nerve plexus in the trachea and extrapulmonary primary bronchus is confirmed. Structures in the luminal epithelium of the trachea, syrinx and extrapulmonary primary bronchus having an afferent innervation are described and their possible function is discussed. The question of positive chemography in autoradiographic studies is discussed.

Animals↗
PubMed1977

Enhanced DNA synthesis in isolated calf lymph node lymphocyte cultures.

Calf sub-mandibular lymph node lymphocytes and human peripheral blood lymphocytes were oxidized by NaIO4. In liquid cell cultures, both types of cells were transformed with enhanced DNA synthesis. In mixed lymphocyte cultures, untreated human lymphocytes were transformed by irradiated-oxidized human cells. However, untreated calf lymphocytes were not transformed by irradiated-oxidized calf cells. Either human or calf lymphocytes were isolated from cell-cell interaction in agarose on slides. After 2-3 days of culture, cells were pulsed with tritiated thymidine. Autoradiography indicated greater numbers of cells with active DNA synthesis in NaIO4-oxidized calf cells and in calf cells incubated with Phaseolus vulgaris E-PHA compared to untreated lymphocytes. Similarly treated human cells did not show any increase in the numbers of cells with active DNA synthesis. No enhancement of DNA synthesis was seen in oxidized calf cells which were reduced with NaBH4 or cultured with hydroxyurea. In these restricted in vitro systems, calf cells are 'transformed' independent of cell-cell interaction, while human cells are not.

Animals↗