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Biomedical subjects

A S Klainer

Publications and source records attributed to A S Klainer.

At least 37 records · Page 2Linked to original sources
PubMed1976

The significance and mechanism of an increased serum phenylalanine-tyrosine ratio during infection.

Infections or inflammatory states often cause significant increases in serum phenylalanine and the phenylalanine-tyrosine ratio. More than 95% of samples obtained during inflammatory diseases in man showed phenylalanine-tyrosine ratio increases greater than the maximum normal values. An increase in this ratio also occurred in monkeys with induced Rocky Mountain spotted fever, viral encephalitis, yellow fever, or pneumococcal and Salmonella infections, as well as in rats with pneumococcal and Salmonella infections, as well as in rats with pneumococcal, Salmonella or tularemia infections. A similar ratio increase occurred in rats inoculated with unpurified mediator substances (released by activated leukocytes) that appear to initiate many of the secondary metabolic phenomena associated with infection and/or inflammation. To identify responsible mechanisms, rats were given lethal doses of Streptococcus pneumoniae; serum phenylalanine and phenylalanine-tyrosine ratios increased significantly. Hepatic phenylalanine hydroxylase activities were slightly decreased when compared to noninfected controls. Infected and noninfected rats showed comparable oxidation rates for 14C-phenylalanine given with an oral phenylalanine load, as a pulse-oral dose, or as an intraperitoneal injection. After 8 hr, both infected and control rats had similar amounts of radioactivity in total body protein, but tissue distributions were markedly altered during pneumococcal sepsis. Serum proteins of infected rats contained almost twice as much total radioactivity as that found in controls, while the amount of labeled phenylalanine in skeletal muscle protein was significantly reduced in the infected group. Isolated muscles from infected rats released more phenylalanine and less tyrosine than control muscles. Infection-related increases in serum phenlalanine could not be explained by decreased hydroxylation or oxidation. Rather, the data were consistent with an increased flux of phenylalanine into serum, most likely as the result of increased skeletal muscle catabolism. Elevations in the serum phenylalanine-tyrosine ratio have potential value for estimating the presence of an inflammatory fisease and the catabolic state of a patient.

Animals↗
PubMed1976

Edwardsiella tarda bacteremia.

Presented are two case reports of patients with Edwardsiella bacteremia who survived after chloramphenicol and gentamicin therapy in one case and cephalothin and kanamycin therapy in the other case. Of four previously reported patients, only one survived. One of our two patients presented with subarachnoid hemorrhage associated with bacterial endocarditis and, to our knowledge, this is the first reported case of E tarda endocarditis. The clinical and laboratory features of disease due to this unusual pathogen are reviewed.

Adult↗
PubMed1975

Transient bacteremia associated with barium enema.

A group of 175 patients had barium enema. Pour-plate blood cultures were obtained immediately before and after the procedure and 5, 10, 15, and 30 minutes later. Bacteremia was demonstrable in 20 (11.4%) patients. In some, blood cultures were positive for as long as 15 minutes after barium enema; all were negative at 30 minutes. Among the bacteria associated with the 20 episodes of bacteremia were Escherichia coli, Klebsiella, enterococci, Proteus morganii, Bacteroides, and Veillonella. The incidence of bacteremia among patients with ulcerative colitis, regional enteritis, rectal polyps, colonic or rectal carcinoma, nonspecific diarrhea, or other lower intestinal tract disorders was not much different from patients free of rectosigmoid disease. The results of this study suggest that a history of recent barium enema may be important in patients who have endocarditis.

Barium Sulfate↗
PubMed1975

Surface alterations due to endotracheal intubation.

The varied complication of prolonged endotracheal intubation, including tracheal stenosis, stricture and tracheomalacia, are thought to be directly related to lateral tracheal wall pressure. To investigate the initiation, relevance and duration of these changes, studies were undertaken to assess the effects of intubation on the surface anatomy of the trachea by scanning electron microscopy. Tracheal mucosal morphology was studies in (1) anesthetized "normal" dogs; (2) d-ogs sacrificed 2 hours after intubation with cuff deflated or inflated to the "just seal" point using a cuff system producing the lowest tracheal wall pressure; and (3) dogs intubated for 2 hours and then examined at 2 and 7 days after extubation. Intubation without cuff inflation resulted in distinct linear areas of nearly complete ciliary denudation along the tract of tubal insertion within 2 hours. Inflated cuffs produced similar but more widespread changes especially over tracheal rings, indicating that pressure in areas of least resiliency significantly contributes to these alterations. Regeneration of cilia could be seen 2 days after extubation, but many anatomic features remained distorted; at 7 days, regeneration was nearly complete, but isolated areas of denudation could still be identified. Scanning electron micrographs of human tracheas taken at autopsy from patients who had had prolonged intubation with the same cuff system correlated well with those obtained from dogs.

Animals↗
PubMed1975

The spectrum of colitis associated with lincomycin and clindamycin therapy.

Ten cases of protracted diarrheal illness after the oral administration of lincomycin or clindamycin in standard dosages were observed in previously healthy subjects. An abrupt onset of diarrhea, crampy abdominal pain, fever, and leukocytosis was observed one to 12 days after discontinuation of the drug. Proctoscopic examination revealed erythematous friable mucosa covered with small raised, yellowish-white plaques that were sometimes confluent. Barium contrast studies of the colon demonstrated irregular shaggy mucosa, ulcerations, cobblestone appearance, and thumb printing. Rectal bipsy showed acute inflammation with pseudomembranes with focal or superficial ulcerations. All patients had a protracted course but recovered with supportive management. Follow-up barium enemas and proctoscopy were done on all patients and were normal. A history of diarrhea, fever, and mucosal changes seen on proctoscopy in a patient who has recently received one of these antibiotics should raise the possibility of colitis associated with clindamycin and lincomycin therapy.

Adult↗
PubMed1975

Detection of a leukocytic endogenous mediator-like mediator of serum amino acid and zinc depression during various infectious illnesses.

Serum samples from patients with many different kinds of infection were shown to contain a substance characteristic of leukocytic endogenous mediator. Generalized bacterial infections produced more leukocytic endogenous mediator than did localized ones; viral infections produced very little. In typhoid fever, mediator concentrations increased before the onset of illness.

Abscess↗
PubMed1974

Effect of the inhibition of protein synthesis on the Escherichia coli cell envelope.

The consequences for cell envelope integrity of Escherichia coli K-12 of the inhibition of protein synthesis by a variety of means have been examined. Protein synthesis was blocked by the antibiotics chloramphenicol and streptomycin, by amino acid starvation of an amino acid auxotroph, and by inactivation of temperature-sensitive aminoacyl transfer ribonucleic acid synthetase and ribosomal mutations. Closely similar morphological and physiological effects were found irrespective of the means by which protein synthesis was blocked. Scanning electron microscopy revealed a spectrum of changes after protein inhibition, with granular material derived from cells and spheroplasts commonly seen. Streptomycin caused additional changes manifested in a collapsed appearance of treated cells. Measurements of the release of lipopolysaccharide from the cell surface, alterations in outer membrane penetrability, and lysis of lysozyme-ethylenediaminetetraacetic acid-treated cultures also showed that the various inhibitory treatments all had similar effects on cell envelope properties. The close correspondence between the effects seen with antibiotic-treated cultures and those in which protein synthesis inhibition was achieved by use of mutants indicates that the effects of chloramphenicol and streptomycin on the cell envelope are indirect consequences of ribosomal block, rather than due to multiple sites of action of the antibiotics.

Bacterial Outer Membrane Proteins↗