Donor/acceptor nature of radiation-induced interface traps

The conductance technique is used to study radiation-induced interface-traps on Sandia Laboratories' radiation-hardened technologies. The density of interface traps, the time constant for interface trap response, and the donor/acceptor nature of the interface traps are investigated. The donor/acceptor nature of interface traps is determined by comparing the theoretical and experimental values of the variance in the conductance peak. Results indicate the presence of both donor and acceptor traps in both parts of the bandgap after irradiation     

Blue nevus of the prostate: ultrastructural study

A case of blue nevus of the prostate in a sixty-five-year-old black patient was studied by light and electron microscopy. In the melanocytes only fully melanized melanosomes were present; melanosomes in early stages of development were entirely absent. It was concluded that the formation of melanosomes within the melanocytes in blue nevus of the prostate is probably under genetic control.     

Aerobically incubated thioglycolate broth disk method for antibiotic susceptibility testing of anaerobes

The anaerobic broth disk (AnBD) method of Wilkins and Thiel and a new modification, designated the thioglycolate broth disk method, were compared with an agar dilution technique. The thioglycolate broth disk method was incubated aerobically (AeTBD) or anaerobically (AnTBD). One hundred anaerobic bacteria representing 15 species were tested with clindamycin, chloramphenicol, erythromycin, penicillin, and tetracycline. Agreement of results by the two methods with minimal inhibitory concentration determinations were: AnBD, 95.2%; AnTBD, 91.5%; AeTBD, 94.5%. With clindamycin, chloramphenicol, and penicillin, the agreement of the AeTBD and agar dilution results was 100%, 100%, and 95%, respectively. Using the AeTBD method, only 1.1% of all tests gave false susceptible readings, whereas 4.4% gave false resistant readings. All susceptibility testing errors occurred with tetracycline, erythromycin, and, to a lesser extent, penicillin. For each method, the changes in designation of bacteria as being susceptible or resistant to an antibiotic between trials primarily involved strains with minimal inhibitory concentrations which were +/- one dilution of the respective breakpoint value. The same situation was true for most bacteria that yielded false resistant readings within each trial. False resistant readings with tetracycline were determined to be unrelated to excess cation content of test media. These results reaffirm the reliability of the AnBD method and indicate that the AeTBD modification is equally reliable. The greater convenience and lower cost of the AeTBD method should make possible more widespread performance of susceptibility testing for anaerobic bacteria in hospital laboratories.     

Method of long-term preservation of the cornea

Treatment results from 45 patients with neuroblastoma are reported. The total survival rate is 29%. In localized stages the survival rate is nearly 100% in patients under one year old and about 50% in patients more than one year old. The survival rate amounts to 50% in stage IV-S, and there is zero survival in stage IV. Comparison with results reported in literature shows the same influences of age, histology and tumor stage on the prognosis. The own results and the reported ones demonstrate that in the majority of the neuroblastoma-patients curative radiotherapy has definite indications.     

Penetration, distribution and retention of chlortetracycline in the body of pregnant rabbits and their fetuses

Chlortetracycline was administered to the rabbits per os in a single dose of 150000 Units/kg. After 29-30 days of pregnancy the rabbits were sacrificied 1--3--6--9--12--24-hours and 2--3--4 days after the drug administration. Three-four rabbits were examined in every experiment. The antibiotic levels were determined by the agar-diffusion method. It was found that chlortetracycline was present in bactericidal concentrations in all 60 tissues of the rabbits and fetus examined except the rabbits eye lens. In some tissues of the rabbit and fetus chlortetracycline persisted up to 3 and 2 days respectively. The antibiotic levels in the organs, tissues and fluids of the fetus were many times lower than those in the rabbits. The concentration peak in the fetus was attained somewhat later and the rate of the concentration decrease was lower as compared to the same indices in the rabbit. The highest concentrations of chlortetracycline in the fetus were registered in the amniotic membranes, joints, bones, urine and amniotic fluid.