Purification and characterization of a ferredoxin from Haloarcula japonica strain TR-1

A ferredoxin (Fd) was purified from the extremely halophilic archaeon, Haloarcula japonica strain TR- 1, to electrophoretic homogeneity. The apparent molecular weight (M _r) of the Fd was estimated to be 24,000 on SDS-polyacrylamide gel electrophoresis. The amino acid composition analysis revealed that the Fd composed of a number of acidic amino acids (uncorrected for amides). The N-terminal amino acid sequence (30 residues) was determined to be: PTVEYLNYEVVDDNGWDMYDDDVFAEASDM. The iron content was 3.42±0.04 mol/mol-Fd on the basis of the apparent M _r value. The absorption and ESR spectra of the Fd showed similarity to those of Fds from plant and Halobacterium halobium. These results led us to conclude that the H. japonica Fd contained a [2Fe-2S] cluster.     

Effect of Tween 80 on the growth of Mycobacterium avium complex

The effect of Tween 80 on the growth of Mycobacterium avium complex (MAC) in liquid culture condition was investigated. Observation of the colony-forming units (CFU) and the morphology of MAC with transmission and scanning electron microscopy showed that Tween 80 at 0.05% in the medium (ca. 0.5 mg/ml) had bacteriostatic action and caused cell elongation. Tween 80 at 0.5% or more in the medium (ca. 5 mg/ml) reduced the quantity of MAC glycolipids and also led to false positive or positive results in biochemical tests for mycobacterial identification using nitrate reductase, urease, or arylsulfatase. To determine whether or not surfactants could reduce the MAC permeability barrier, the minimal inhibitory concentration (MIC) of antituberculosis drugs on MAC was determined in liquid medium with or without several kinds of surfactants including Tween 80. Five surfactants including Tween 80 increased the activity of antituberculosis drugs to MAC. These findings suggest that Tween 80 acts directly on the cell wall of MAC.     

Analytical study of repair cells

To establish the differential diagnosis of repair cells from malignant cells, 624 repair cells from 11 cases, 547 cells derived from 8 adenocarcinomas and 593 cells from 8 squamous-cell carcinomas were analyzed, with stress on the morphology of the nucleoli. Such planimetric data as mean cellular areas, mean nuclear areas, mean nucleolar areas, nuclear-cytoplasmic ratios and nucleolar-nuclear ratios were fairly similar among the three cell groups. However, the even distribution of nucleoli in the nuclei, the decrease in C-type nucleoli and nucleoli consistently linked with nucleolus-associated chromatin were noted to be reliable criteria for the diagnosis of repair cells along with such well-known morphologic characteristics as the sheetlike arrangement of repair cells, the lack of isolated forms, the finely granular chromatin pattern and the round, smooth nuclear configuration with a thin nuclear membrane.     

Presynaptic calcium concentration microdomains and transmitter release.

n-Aequorin J, a luminescent protein which responds to calcium concentration changes in the order of several hundred micromoles, was injected into the preterminal fiber in the squid giant synapse. The activation of the presynaptic terminal leading to release of transmitter was accompanied by light emission at well-defined sites at the active zone in the presynaptic terminal. Location of these light emission sites was very much the same from one stimulus to the next, indicating that light emission was triggered by the inward calcium current occurring at specific and invariant locations. The distribution, size and number of these QEDs (quantum emission domains) coincides well with the location and number of active zones in the presynaptic terminal. The results imply that transmitter release is triggered by very well-localized calcium concentration changes that may be as high as several hundred micromoles.     

Experimental studies on vertical infection of mice with Japanese encephalitis virus III. Effect of gestation days at the time of inoculation on placental and fetal infection

An experiment was carried out on the effect of gestation days at the time of inoculation on the establishment of experimental vertical infection with Japanese encephalitis virus in mice. In it, mice of the CFW strain in a closed colony were inoculated intravenously with a field strain at different times over a period from 3 to 12 days of gestation. After that, an attempt was made to recover the virus from the placenta and fetus to estimate the rate of infection. As a result, placental infection was established not when the virus was inoculated at 3 days of gestation, but when it was inoculated at 4 days of gestation or later. The rate of infection was relatively high when the virus was inoculated at 6 days of gestation or later. Fetal infection was established relatively frequently when the virus was inoculated some time between 7 and 10 days of gestation, but quite infrequently when the virus was inoculated at any other time than this. There was a difference in rate between placental and fetal infection at a given time of inoculation in days of gestation. This difference seemed to have been induced not by a difference in intensity of viremia appearing after inoculation, but by a difference in degree of development between placental and fetal tissues at the time of inoculation.     

Papillary carcinoma of the thyroid occurring during pregnancy. Report of a case diagnosed by fine needle aspiration cytology

A case of papillary carcinoma of the thyroid gland occurring during pregnancy in a 29-year-old woman is described. The enlarged thyroid nodule was first detected at 10 weeks of gestation; fine needle aspiration (FNA) of the nodule showed no cytologic evidence of malignancy. Repeat FNA at 30 weeks of gestation produced inadequate material for diagnosis. A final FNA at 38 weeks of gestation showed classic cytologic features of papillary carcinoma, including papillary structures, grooved nuclei and intranuclear cytoplasmic inclusions. After delivery, the patient was treated with total thyroidectomy and cervical lymph node dissection. The enlargement of the nodule in this case during the course of the pregnancy suggests a relationship between pregnancy and the malignant development of thyroid nodules; this is discussed along with the utility of FNA cytology for diagnosing thyroid cancers during pregnancy.