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T Kasuga

Publications and source records attributed to T Kasuga.

194 records · Page 11Linked to original sources
PubMed1968

Drug resistance of staphylococci. VII. Genetic determinants responsible for the resistance to tetracycline, streptomycin, sulfanilamide, and penicillin.

A genetic analysis of resistance to tetracycline (TC), streptomycin (SM), sulfanilamide (SA), and penicillin G was carried out through transduction with phage lysates obtained from a multiply resistant strain of Staphylococcus aureus by ultraviolet irradiation. All transductants acquired resistance to both TC and SA, even when singly selected for either SA or TC resistance. The locus responsible for TC resistance could not be separated genetically from that for SA resistance. On the other hand, in transduction of SM resistance, about 30% of the transductants jointly acquired resistance to both TC and SA. These observations suggest that the loci governing resistance to TC, SA, and SM exist close together on a single genetic unit, this probably being the chromosome.

Chromosome Mapping↗
PubMedDate not supplied

Interaction between the short-wavelength cone and rod systems in the electroretinogram of the cynomolgus monkey.

We recorded electroretinograms from anesthetized cynomolgus monkeys by means of three monochromatic (435, 524 or 579 nm) full-field stimuli presented with a monochromatic background light. The color of the background light was changed with 29 interference filters (400-700 nm). Waveforms were analyzed by means of principal component analysis to investigate interaction between the short-wavelength cone and other systems. With the same test lights, responses were also recorded during dark adaptation after 20,000-lux full bleach. The shape of the short-wavelength cone electroretinogram changed as a function of the wavelength of monochromatic background light. The change was clearer around 500-nm background light, to which the rod system is highly sensitive. Further, short-wavelength cone responses developed during the first 15 min in the dark; however, they became smaller with the recovery of the rod system. These findings suggest that there is interaction between the short-wavelength cone and rod systems. In addition, the results of waveform analysis confirmed the interaction between the long-wavelength and middle-wavelength cone systems.

Animals↗
PubMedDate not supplied

Effects of a six-week exposure to excess iodide on thyroid glands of growing and nongrowing male Fischer-344 rats.

A 6-wk exposure to excess iodide intake (EII) via drinking water (260 mg potassium iodide/L) demonstrated different effects on growing (4-wk old) and nongrowing (45-wk old) male Fischer-344 rats. In growing rats, EII induced a significant increase in thyroid weight, pituitary weight, serum thyroid-stimulating hormone (TSH), and thyroxine (T4). The labeling index (LI) of thyroid follicular cells was slightly increased, although not statistically significant. Histologically, an increase in follicular cell height, an increase in colloid accumulation, and evidence of colloid absorption were noted. The effect of bovine TSH (bTSH) and protirelin tartrate (TRH-t) on LI was significantly augmented by EII. In nongrowing rats, EII induced a significant increase in thyroid weight and serum T4 but no increase in pituitary weight, serum TSH, and the LI of follicular cells. Histologically, an increase in colloid accumulation was found in small follicles. EII did not augment the effect of bTSH and TRH-t on the LI of follicular cells. This study suggests that growing rats are still susceptible to acute hypothyroidism even after 6 wk of continuous exposure to excess iodide, whereas nongrowing rats are refractory within an equivalent treatment period.

Aging↗
PubMedDate not supplied

Digital tomosynthesis imaging of the lung.

We report our preliminary results of pulmonary imaging by digital tomosynthesis, and describe some advantages of these digitally processed longitudinal tomographic images. Digital tomosynthesis of the lung was performed in 60 subjects, including 56 patients with a localized lesion or diffuse disseminated lesions, with a fluororadiographic TV unit with linear tomographic capability, in conjunction with an image processing unit. Dual energy subtraction digital tomosynthesis was also available in our system. Multiple longitudinal tomographs of the lung, which were reconstructed from a single set of tomographic image data, facilitated easy evaluation of the morphology of pulmonary abnormalities together with related broncho-vascular structures located in the same longitudinal plane as the lesion, and were immune from any problem caused by inconsistent depth of respiration. The image quality of the reconstructed tomographs was greatly improved by digital image processing to reduce tomographic blur and enhance image clarity. Dual energy subtraction digital tomosynthesis was effective in clearly showing the size, configuration, and distribution of calcification in the lesion. Digital tomosynthesis provided useful information in making the roentgenologic diagnosis of pulmonary lesions.

Adult↗