Biomedical subjects

P Sacks

Publications and source records attributed to P Sacks.

11 recordsLinked to original sources

PubMed1990

The analysis of natural killer cell activity by flow cytometry.

A flow cytometric assay was used to detect the lytic and binding capacities of both fresh peripheral blood lymphocytes and purified Leu-19+ natural killer cells against head and neck cancer cell lines. Results demonstrated that natural killer cell-mediated cytotoxicity and effector-target conjugate formation evaluated by flow cytometry was significantly correlated with the standard chromium 51 release assay and the single-cell microscopic assay, respectively. The sorted Leu-19+ natural killer cells demonstrated higher lytic capacity with a corresponding higher binding rate compared with the unsorted peripheral blood lymphocytes and sorted Leu-19- cells. Flow cytometric analysis of natural killer cell activity (a rapid, simple, and quantifiable procedure) is an alternative to the standard chromium 51 release assay.

Antigens, Differentiation, T-Lymphocyte↗

PubMed1989

Ca2+ absorption in the pars recta of cortical S2 rabbit proximal tubules: role of diffusion.

Individual partes rectae of cortical S2 proximal tubules were dissected from rabbit kidneys and perfused in vitro. The bath was a protein-free, plasmalike solution, whereas the perfusate simulated "late" proximal tubular fluid (high [Cl-], low [HCO3-], absence of Na+-cotransported solutes). Transepithelial voltages at the perfusion and collection ends were measured simultaneously in doubly cannulated tubules. Ionized calcium concentrations in perfusates, collectates, and the bath were calculated from measurements of calcium ion activities made in situ with Ca2+-selective microelectrodes. Epithelial calcium permeability was estimated from the bath-to-lumen movement of 45Ca. Total calcium concentrations of perfused and collected fluids were measured by continuous-flow microcolorimetry. Under these conditions there was a lumen-positive transepithelial voltage that was equal at both ends of the tubules. Luminal [Ca2+] [corrected], which decreased along the length of the tubule, was greater than that of the bath. Using the measured calcium permeability, we calculated the diffusional component of the net calcium absorptive flux from the mean transepithelial delta [Ca2+] and the measured transepithelial voltage. We found that ionic diffusion accounted for the net flux, suggesting that diffusion is the primary mechanism of calcium absorption in this segment of the rabbit nephron.

Absorption↗

PubMed1987

Recurrent reversible acute renal failure from amphotericin.

A patient with cryptogenic cirrhosis and disseminated sporotrichosis developed acute renal failure immediately following the administration of amphotericin B on four separate occasions. The abruptness of the renal failure and its reversibility within days suggests that there was a functional component to the renal dysfunction. We propose that amphotericin, in the setting of reduced effective arterial volume, may activate tubuloglomerular feedback, thereby contributing to acute renal failure.

Acute Kidney Injury↗

PubMed1985

Ventricular tachycardia in acute rheumatic fever.

A 19-year-old man presented with fever, migratory polyarthritis, and palpitations; a diagnosis of acute rheumatic fever was made. Twenty-four-hour ambulatory cardiac monitoring (Holter) performed during the patient's hospitalization revealed ventricular tachycardia. Although disturbances in cardiac conduction and rhythm are common during the acute phase of rheumatic fever, malignant ventricular arrhythmias, to our knowledge, have not been described. Recognition of this occurrence emphasizes the need for continuous cardiac monitoring in selected patients.

Acute Disease↗

PubMed1978