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Biomedical subjects

L M Pachman

Publications and source records attributed to L M Pachman.

At least 91 records · Page 5Linked to original sources

Effect of sodium salicylate on hamster cells in vitro.

Doses of sodium salicylate greater than 100 mug/ml increased the generation time of baby hamster kidney (BHK 21) cells in culture from 16 to 35 hr. Exposure to similar doses of salicylate for 18-44 hr resulted in a marked reduction of RNA synthesis. The species of RNA synthesized in the presence of sodium salicylate appeared to be similar to those synthesized by normal cells in the absence of sodium salicylate. Sodium salicylate did not alter the oxidative phosphorylation of BHK cells.

Animals↗

The effect of heat-killed streptococci on the survival of heart grafts in inbred strains of mice.

Studies with inbred strains of mice revealed that exposure to type 12, Group A, beta-hemolytic streptococci affects the host response to heart grafts implanted in the ear. Intraperitoneal injection of streptococci 10 days before grafting led to curtailed survival of syngrafts without altering the normal rejection time of allografts. Similar sensitization, combined with local injection of streptococci into the graft site at the time of grafting, was followed by rapid rejection of both syngrafts and allografts. The time interval between exposure and grafting was critical. Injection with streptococci 5 days before grafting led to a prolonged survival of allografts and no demonstrable effect on syngrafts. In contrast, injection of streptococci 15 days before grafting did not alter survival of either type of graft. The data indicate heart grafts implanted in the ear may serve as a useful model for the study of the host responses to streptococcal antigens.

Animals↗

The effect of parenteral alimentation fluid, undiluted with saline or fresh sera, on the growth of Candida albicans in vitro at 37 degrees C.

Parenteral alimentation is often complicated by Candida albicans infection which may be fatal. This study investigated the effect of alimentation fluid (Aminosol) on C. albicans' growth in vitro. It was found that concentrated Aminosol (1400 millisomoles) maintained C. albicans in a viable state but inhibited replication. Dilution of alimentation fluid to physiological concentrations (300 milliosmoles) with either saline or aged pooled normal sera promoted in vitro growth of C. albicans which was equivalent to that obtained in BHI broth and was slightly less than that obtained in Sabouraud's broth. The effects of fresh sera with full complement activity were also investigated. In fresh sera appropriately diluted with physiological saline, some clumping of the yeasts was observed and all formed germ tubes. Growth as defined by budding or the formation of hyphae was inhibited. When Aminosol was diluted to 300 milliosomoles with fresh sera, all yeasts were noted to be in clumps with germ tubes as well as continually growing hyphae. Growth was approximately equal to that seen in Aminosol similarly diluted with saline.

Blood Proteins↗

Chronic neutropenia: Response to plasma with high colony-stimulating activity.

A child with repeated infections was immunologically normal but was found to have neutropenia with periodic elevations of the absolute mature polymorphonuclear count at 21-day intervals. Immediately following the PMN rise, bone marrow morphology and in vitro cultures demonstrated a maturation arrest at the myelocyte stage with an increase in proliferative capacity. His cycle was not altered by infusions of normal plasma or by injections of epinephrine or typhoid vaccine. Infusion of 10 ml/kg of "stimulated" plasma from donors reactive to TV, obtained 60 minutes following immunization, resulted in an out-of-phase rise in PMN cells and clinical improvement. In vitro assays, using normal or patient marrow, detected high levels of colony-stimulating activity only in those plasma samples that were effective in the patient. These observations support a role of CSA as a physiologic regulator of granulopoiesis in man.

Agranulocytosis↗

Cor pulmonale secondary to upper airway obstruction. Cardiac catheterization, immunologic, and psychometric evaluation in nine patients.

Previous reports of cor pulmonale due to upper airway obstruction have not noted that chronic hypoxemia due to alveolar hypoventilation can lead to left as well as right ventricular failure in these patients. We found elevated left ventricular end-diastolic pressure in four of five patients. Although these patients have frequent respiratory infections, no investigation of their immune status has previously been reported. We performed such investigations but could not demonstrate an immunologic deficiency. Although nine of 44 patients previously reported were mentally retarded, no psychometric data were available. We studied five patients but could not determine the role of mental subnormality in this syndrome. Diagnosis of this syndrome should be suspected when clinical and roentgenographic findings of biventricular heart failure are associated with right ventricular hypertrophy on electrocardiogram. The diagnosis of alveolar hypoventilation is confirmed by blood gas findings and examination of the upper airways. Surgical removal of obstructive tissue reverses the cardiac involvement.

Adenoidectomy↗

The effect of salicylate on the metabolism of normal and stimulated human lymphocytes in vitro.

The effect of salicylate on the metabolism of peripheral blood lymphocytes in tissue culture was investigated. Lymphocytes incubated with sodium salicylate at a concentration of 30 mg/100 ml showed increased glucose consumption, lactic acid production, and oxygen consumption, evidence for uncoupling of oxidative phosphorylation. No decrease in cell number or viability (trypan blue dye exclusion) was noted in salicylate-treated cultures. Normal DNA, RNA, and total protein synthesis measured by radioisotope incorporation was depressed in the salicylate-treated cultures. Increased DNA synthesis after the addition of a mitogen (PHA) or antigen (PPD) to the culture was strikingly suppressed by salicylate. The degree of suppression was proportional to the concentration of salicylate used. The effect on RNA and protein synthesis in stimulated lymphocytes was much less pronounced. Acetylsalicylic acid was found to be as active as sodium salicylate in suppressing DNA synthesis, but the p-OH congener (p-OH benzoic acid) did not alter cell respiration, glycolysis, viability, or DNA synthesis. The salicylate effect was reversible as evidenced by return of cellular reactivity upon removal of the drug from the media.

Antigens↗