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Biomedical subjects

R Ehrlich

Publications and source records attributed to R Ehrlich.

At least 307 records · Page 17Linked to original sources

The elution of antibodies from viable murine tumor cells.

Several low pH buffers were used in order to dissociate radioiodinated antibodies from sensitized living tumor cells. Three buffers were further tested for their dissociation abilities under different conditions of time and temperature, and for their influence on the eluted antibodies. The cytotoxicity mediated by these low pH buffers was also determined by viability assays. Optimal results were obtained with 0.1 M citrate buffer at pH 3.5.

Animals↗

Effects of repeated exposures to peak concentrations of nitrogen dioxide and ozone on resistance to streptococcal pneumonia.

Exposures to various mixtures of nitrogen dioxide (NO2) and ozone (O3) reduced the resistance of mice to streptococcal pneumonia as evidenced by increased mortality rates and shortened survival time. Daily 3-h exposures (5 d/wk) for 2--6 mo to an air pollutant mixture consisting of 940 microgram/m3 (0.5 ppm) NO2 and 196 microgram/m3 (0.1 ppm) O3 were most effective in reducing the resistance to infection. The decrease in resistance to the infection occurred sooner than the mice continued to be exposed to the air pollutants instead of clean air for 14 d after the respiratory challenge with Streptococcus pyogenes aerosol. After 3 mo of exposure to the pollutant mixture, there was some decrease in the ability of mice to clear inhalated streptococci from their lungs. At the same time the total cell count in the fluid lavaged from the lungs of mice was markedly reduced, as were the viability and phagocytic activity of the alveolar macrophages. Exposure to the pollutants combined with challenge with Streptococcus aerosol resulted in marked morphological changes in lung tissues as seen by scanning electron microscopy.

Animals↗

Lack of correlation between affinity of the tRNA for the aminoacyl-tRNA synthetase and aminoacylation capacity as studied with modified tRNAPhe.

The interactions of several modified yeast tRNAPhe [tRNAPhe lacking 7-methylguanine; a fragment comprising about 3/4 of the whole molecule: tRNAPhe (18--76); tRNAPhe (18--76) lacking 7-methylguanine] with yeast phenylalanyl-tRNA synthetase were studied. Upon excision of the 5'-quarter of the tRNAPhe molecule, the residual fragment still tightly binds to the synthetase, but can no longer by aminoacylated. Surprisingly, upon removal of the 7-methylguanine base at position 46 in this fragment, althought the affinity drops by a factor 10, a significant aminoacylation is restored. These results are discussed in terms of molecular flexibility and a model is proposed for tRNA-enzyme interaction, involving multisite recognition.

Amino Acyl-tRNA Synthetases↗

Immunochemical analysis of the structure of eukaryotic ribosomes: antigenic properties of rat liver ribosomes and ribosomal proteins and characterization of the antisera.

Antibodies were prepared in rabbits and sheep to rat liver ribosomes, ribosomal subunits, and to mixtures of proteins from the particles. The antisera were characterized by quantitative immunoprecipitation, by passive hemagglutination, by immunodiffusion on Ouchterlony plates, and by immunoelectrophoresis. While all the antisera contained antibodies specific for ribosomal proteins, none had precipitating antibodies against ribosomal RNA. Rat liver ribosomal proteins were more immunogenic in sheep than rabbits, and the large ribosomal subunit and its proteins were more immunogenic than those of the 40S subparticle. Antisera specific for one or the other ribosomal subunit could be prepared; thus it is unlikely that there are antigenic determinants common to the proteins of the two subunits. When ribosomes, ribosomal subunits, or mixtures of proteins were used as antigens the sera contained antibodies directed against a large number of the ribosomal proteins.

Animals↗

Improved electrophoretic and immunochemical techniques for the identification and characterization of mutant proteins, applied to ribosomal protein S8 in Escherichia coli mutants.

The ribosomal proteins of 11 mutants which are sensitive to starvation at elevated temperature and of 36 transductants derived from them were studied with several electrophoretic, immunochemical and proteinchemical methods. The following results were obtained: (1) Ribosomal protein S8 is altered in three of these mutants. (2) The amino acid exchange in proteins S8 of mutant N4128 is Glu leads to Lys in position 59 of the protein chain. (3) Temperature sensitivity and inability to recover from starvation at elevated temperatures are caused by the same mutational event which is, however, unrelated to the alteration in protein S8. Several electrophoretic and immunological procedures were applied during the characterization of these mutants. A modified immunoelectrophoresis on cellulose acetate gels was developed, and proved to be the most applicable procedure for the detection of mutationally altered ribosomal proteins. This procedure may gain general importance for detecting mutational alterations in other proteins.

Amino Acid Sequence↗

Systemic candidiasis following cardiac surgery: an improved outlook.

Systemic candidiasis following cardiac surgery, previously regarded as fatal, has now a much improved prognosis. Prognosis depends largely on early diagnosis and treatment. Four of five patients we recently treated for this disease survived. The presence of several predisposing factors in a febrile patient following cardiac surgery should alert the physician to the possibility of this disease.

Amphotericin B↗

Trisomy 9 syndrome.

An infant is described with multiple congenital anomalies associated with mosaic trisomy 9. Review of the three previously reported cases of trisomy 9 shows that these patients have several common features which make trisomy 9 a clinically distinct syndrome. The frequently encountered findings are: upward-slanted eyes, small palpebral fissures, enophthalmos or microphthalmos, broad base and prominent tip of the nose, microcephaly, micrognathia, low-set malformed ears, high-arched palate, congenital heart disease, skeletal and genito-urinary anomalies, abnormal palmar creases, failure to thrive, hypotonia and retardation.

Abnormalities, Multiple↗

Ultrasound diagnosis of common bile duct dilatation.

The use of ultrasound in the differential diagnosis of obstructive jaundice has been previously reported. Although common bile duct dilatation has been demonstrated, criteria for its accurate identification have not been stressed. This report describes findings and relationships helpful in recognition of a dilated common bile duct. It is important to identify this structure, since it could otherwise be confused with surrounding vessels.

Adenocarcinoma↗

Granulomatous disease of male genitalia.

Five cases of granulomatous disease of the male genitalia are presented. Of these, 3 cases involved foreign-body reactions in which some form of hydrocarbon was the causative agent. In the other 2 cases, idiopathic granulomatous processes were found, and this condition may be secondary to endogenous lipoid degenerative processes.

Adult↗

Compression neuropathy subsequent to renal transplantation.

Compression neuropathy occurred in 7 patients who underwent renal transplantation. The neuropathy occurred on the same side as the surgery and was associated with the use of selfretaining retractors. Other contributing factors were presence and degree of uremia and diabetes. We suggest that self-retaining retractors be used carefully and length of application reduced to a minimum. Efficient dialysis prior to transplantation may decrease the incidence and severity of neurologic deficit by reducing the extent of uremia.

Adult↗

Radiographic findings in early acquired syphilis: case report and cirtical review.

The radiographic and pathophysiologic features of early acquired syphilis are discussed. Bone changes occur in early acquired syphilis and should not be confused with gummas of late syphilis. The radiographic findings are protean and may exist without a clinical history of a cutaneous lesion. The skull, clavicle, and tibia are the sites most frequently involved.

Adult↗