Nonhistone nuclear proteins specific to certain mouse embryonal carcinoma clones having an inactive X chromosome

By means of one-dimensional polyacrylamide slab gel electrophoresis nonhistone nuclear proteins were compared in murine embryonal carcinoma cell clones with two X chromosomes; both are active in some clones and one of them is inactive in others and in a population of cells having only one X chromosome. Under our experimental conditions, we succeeded in finding two extra bands at approximately 46,000 Da in cells having an inactive X chromosome. Furthermore, a band at approximately 71,000 Da was significantly heavier in cells having an inactive X chromosome than in those having two active X or those having only one X chromosome.     

The changes in plasma cortisol and urinary free cortisol by an overnight dexamethasone suppression test in patients with Cushing's disease

We studied the suppressibility of cortisol secretion in 15 patients with Cushing's disease by measuring morning plasma cortisol level as well as the 24-hour urinary free corisol (UFC) excretion following single doses of increasing amounts of dexamethasone (ranging from 0.5 to 32 mg) given at 11 p.m. The mean plasma cortisol level in patients with Cushing's disease was twice as high as in normal subjects, whereas the mean UFC in these patients was 6 times as high. Plasma cortisol in seven patients were suppressed by less than 4 mg of dexamethasone (in 2 cases, less than 0.5 mg; in 3 cases, less than 2 mg; and in 2 cases less than 4 mg). In these cases, basal plasma cortisol and UFC were less than 25 micrograms/dl and 350 micrograms/day, respectively. Among the other eight patients, plasma cortisol was partially suppressed in 5 cases and not suppressed in 3 cases by high doses of dexamethasone (16-32 mg). In these cases the basal plasma cortisol and UFC were more than 25 micrograms/dl and 350 micrograms/day, respectively. There was a significant correlation between the basal plasma cortisol and UFC (r = 0.687, p less than 0.01). These data suggest that the suppression by increasing amounts of dexamethasone in most cases with Cushing's disease was related to the severity of hypercortisolism.     

Sotos syndrome with a balanced reciprocal translocation t(2;12)(q33.3;q15)

A balanced reciprocal translocation, 46,XY, t(2;12), was detected in a male infant who had the characteristic features of Sotos syndrome. His father's karyotype was normal, but his mother and an older brother had the same chromosomal abnormality without a history or clinical features of Sotos syndrome.     

Endothelin-induced Ca-independent contraction of the porcine coronary artery

Front surface fluorometry and porcine coronary arterial strips loaded with fura-2 were used to investigate the effect of endothelin on cytosolic Ca concentrations, [Ca]i, and on contractile force, the objective being to elucidate the mechanism of action. Both in the presence and absence of extracellular Ca, endothelin induced rapid and dose-dependent increases in [Ca]i and in contraction. When caffeine-sensitive and histamine-sensitive intracellular Ca stores were depleted, in Ca-free medium, a transient contraction but no increase in [Ca]i followed the subsequent application of endothelin. This Ca-independent component was largely inhibited by the relative protein kinase C inhibitor, H-7, but not inhibited by W-7, calmodulin antagonist. This component is probably linked to activation of protein kinase C.     

Molecular cloning of an ice nucleation gene from Erwinia ananas and its expression in Escherichia coli

Abstract An approximately 7 kbp genomic DNA fragment was cloned from an ice nucleation-active (ina) strain of Erwinia ananas and defined as to its restriction enzyme site. When the DNA fragment was introduced into E. coli MM294, a potent ice nucleation activity was expressed. Both 0.7 kbp truncation from the 5'-end and 1.7 kbp truncation from the 3'-end were also effective in expressing the ice nucleation activity in E. coli . Therefore, the resulting DNA fragment of approximately 5 kbp was considered to be an ina gene and named ina A. It existed as a unique gene in this strain of E. ananas . No corresponding ina gene existed in an ice nucleation-inactive strain of E. milletiae .     

Immunocytochemical demonstration of GAP-like immunoreactive neuronal elements in the human hypothalamus and pituitary

Summary GnRH-associated peptide (GAP)-like immunoreactive elements located in the human hypothalamus were investigated by PAP immunocytochemistry using specific antiserum against [pro-GnRH (14–69) OH]. Immunoreactive neuronal perikarya were distributed in the MPOA, PVN and infundibular nucleus, with the largest numbers of GAP-like immunoreactive perikarya found in the infundibular nucleus. We also detected the coexistence of GAP-like and GnRH-like immunoreactivities in the same neuronal perikarya in the MPOA by using a double immunolabelling procedure. In addition to the above regions immunoreactive neuronal perikarya were present in the region dorsal to the medial mammillary nucleus. GAP-like immunoreactive fibers were distributed in same areas that immunoreactive perikarya were observed. Many immunoreactive terminals were found adjacent to capillaries in the infundibulum. Immunoreactive dots, presumably terminals, were observed in the posterior pituitary and these were particularly evident along the margin adjacent to the anterior pituitary. The distribution pattern and density of GAP-like immunoreactive neuronal elements are compared with those of other mammalian species. We also compared GAP-like immunoreactive elements with that of GnRH as has been previously observed in the human hypothalamus.     

Enhanced superoxide anion generation but reduced leukotriene B4 productivity in thioglycollate-elicited peritoneal macrophages

Lipoxygenase metabolism of arachidonic acid was compared between peritoneal macrophages from untreated rats and those from rats on day 7 after intraperitoneal injection of thioglycollate broth (TG). Resident macrophages (M phi) from untreated rats produced mainly LTB4 (303 +/- 25 pmol/5 x 10(6) cells) and 5-HETE (431 +/- 56 pmol/5 x 10(6) cells) when stimulated with 5 micrograms/ml calcium ionophore A23187 for 20 min at 37 degrees C. On the other hand, TG-elicited M phi generated less amounts of lipoxygenase metabolites (157 +/- 10 pmol LTB4 and 319 +/- 19 pmol 5-HETE/5 x 10(6) cells) with the same stimulus. Then, leukotriene productivity was examined by using subcellular fractions of each M phi lysate and an unstable epoxide intermediate, leukotriene A4. LTA4 hydrolase activity was mainly contained in soluble fractions from the both groups of M phi. The cytosol fraction from the resident M phi exhibited the following specific and total activity; 2.2 +/- 0.1 nmol LTB4/mg protein/5 min and 12.2 +/- 0.5 nmol LTB4/5 min per 10(8) cells. On the contrary, the cytosol fraction from the TG-elicited M phi showed 1.9 +/- 0.1 nmol LTB4/mg protein/5 min and 9.6 +/- 0.3 nmol LTB4/5 min per 10(8) cells. The resident M phi, however, generated 0.14 +/- 0.04 nmol O2-/min/4 x 10(5) cells whereas the TG-elicited M phi did 0.49 +/- 0.13 nmol O2-/min/4 x 10(5) cells when stimulated with wheat germ lectin. These results suggest that the TG-elicited macrophages show enhanced superoxide production but generate less lipoxygenase metabolites.(ABSTRACT TRUNCATED AT 250 WORDS)     

Isolation of Rickettsia tsutsugamushi antigenically different from Kato, Karp, and Gilliam strains from patients

Rickettsia tsutsugamushi strains from three recent patients of Tsutsugamushi disease in Niigata Prefecture were isolated primarily in mice and then in L cell cultures. By this procedure, low virulent strains to mice, as well as high virulent ones, could be isolated and cultivated serially in L cell cultures, suggesting the usefulness of L cells for isolation of this species of rickettsia. Each newly isolated strain was identified as a member of R. tsutsugamushi from the results of cross immunological tests and morphological observation. On the other hand, it was recognized that one of these rickettsiae showed immunological properties distinguishable from the prototype strains of Kato, Karp, and Gilliam by the cross complement fixation test, and also had low virulence in mice.     

Studies on defense mechanisms against Candida albicans infection in congenitally athymicnude (nu/nu) mice

The defense mechanisms against Candida albicans infection were studied by using a mouse thigh lesion model in congenitally athymic nude (nu/nu) mice and their normal littermates (nu/+). Nu/nu mice were more resistant to C. albicans infection than nu/+ mice judging from the course of the thigh lesion, the results of CFUs (colony-forming units) of C. albicans in the lesion, and histopathological observations. Histopathological and serological studies revealed that granulocytic cellular infiltration was predominant, and there were few indications of development of cell-mediated immunity to protect Candida infection in Candida-infected nu/nu and nu/+ mice. These results confirmed that lower susceptibility of nu/nu mice to C. albicans infection as compared with nu/ + mice was due to accelerated non-specific defense mechanisms in nu/nu mice, and that cell-mediated or humoral immunity played a minor role in the defense against Candida infection in this experimental model.Furthermore, treatment with high titer of rabbit anti-C. albicans serum was effective to control the number of Candida cells in thigh lesions of BALB/c mice.Above experimental results seem to clearly indicate the great variability of defense manifestation according to the experimental model exployed.     

Release of Citric Acid into the Medium by Aluminum-Tolerant Carrot Cells

One physiological characteristic of an Al-tolerant cell line(TA-1) selected from a cultured carrot cell line (SO-1) wasthe release of more citric acid into the medium than the parentalSO-1 line. Aluminum chloride was added to the media at a concentration,at which SO-1 as well as TA-1 could grow normally without inhibition.The amounts of citric acid and the soluble Al present in themedium were determined during the growth period. Much citricacid was released from TA-1 cells into the medium in the firsthalf of the culture period. At the time of maximum growth, theamount of citric acid in the medium of TA-1 cells was twiceas much as in the medium of SO-1 cells. The precipitates ofAl compound(s), which were formed in the medium by the additionof AlCl₃ as the Al source, became soluble as culture proceeded,depending on the amount of citric acid present in the medium. (Received September 3, 1983; Accepted May 9, 1984)