Changes in the nitrogen localized in the lamellae systems and stroma of rice chloroplast accompanying the stages of growth

The change in the nitrogen localized in the lamellae systems and stroma region of the rice chloroplast was pursued throughout the stages of growth and, further, the relationship between the composition of the chloroplast and leaf N content was examined. A common trend accompanying the stages of growth is recognized: that in the early stages of growth the amount of nitrogen existing as a form of stroma N is larger than that of lamellae N. Thereafter, stroma N tends to decrease in relation to lamellae N and finally, lamellae N becomes a dominant nitrogenous fraction in the chloroplast. The change in the composition of the chloroplast seems to be brought about by a change in the nitrogen metabolism of the chloroplast by which the distribution of absorbed nitrogen among the nitrogenous fractions of the chloroplast differs.     

Tea plant (Camellia sinensis L.) roots secrete oxalic acid and caffeine into medium containing aluminum

We examined the response of the tea plant (Camellia sinensis L.) to aluminum (Al) exposure under sterile conditions, focusing specifically on the secretion of low molecular mass organic compounds from roots. After germination in agar medium, tea seedlings together with medium were placed on agar containing 0.4?mM Al with 0.2% hematoxyline (hematoxylin-Al medium). The purple color of the hematoxylin-Al medium was observed to fade gradually, until none of the color remained 6 days later. The tea seedlings were then treated with simple calcium solution (0.2?mM, at pH 4.2) containing AlCl₃, which ranged in concentration from 0 to 0.8?mM, for 24?hrs. The amount of oxalate secreted into the medium increased as the external Al concentration increased, while the concentrations of malate and citrate in the medium remained unchanged. Oxalate secretion started within 30?min after Al exposure and increased linearly thereafter. The findings demonstrated that oxalate was a key compound in the Al-tolerance mechanism employed by the tea plant, which detoxifies Al³⁺ externally in the rhizosphere. In addition to oxalate, caffeine was also secreted by tea roots in response to Al exposure. It is possible that caffeine excretion from the roots of tea plants may stimulate root growth through the inhibition of callose deposition in root tips.     

Inositol 1,4,5-triphosphate receptor protein immunohistochemistry of cerebellar Purkinje cells in two dogs with hypoglycemia

Immunohistochemical study was performed on cerebellar Purkinje cells of two dogs with hypoglycemia using an antibody against the inositol 1,4,5-triphosphate receptor that is identical to the cerebellar Purkinje cell glycoprotein P(400) (P(400)/InsP(3)R). In the cerebellar neocortex of an acute case of hypoglycemia, the P(400)/InsP(3)R staining of hypoglycemic Purkinje cells was heterogeneous: some peripheral dendrites, including spiny branchlets, were negative and others were stained with various intensities, although Purkinje cells were morphologically intact by hematoxylin and eosin (HE) stain. In a chronic case of hypoglycemia, almost all the dendrites of Purkinje cells of both the neo- and archicortex of the cerebellum were not stained with the P(400)/InsP(3)R antibody. This is in contrast to the normal dog where Purkinje cell bodies, axons, and dendrites, including spiny branchlets, are intensely stained by the P(400)/InsP(3)R antibody. These results suggest that P(400)/InsP(3)R immunolabeling of Purkinje cells decreased, despite their morphology being preserved by HE stain, and that the function of P(400)/InsP(3)R, especially in spiny branchlets that receive inputs originating from axon terminals of parallel fibers, may be impaired in hypoglycemia.     

Rumen ciliate protozoal fauna of reindeer in Inner Mongolia, China

Rumen ciliate species and composition were surveyed on the reindeer kept in Inner Mongolia, China. As a result of survey, all the reindeer had the same 18 species of 8 genera of the ciliates in their rumen. Appearance of Entodinium parvum is the first record in this host species. Of the species detected, 15 species including Entodinium anteronucleatum, E. bicornutum, Enoploplastron confluens and Epidinium gigas which have been detected only from reindeer were common with those in the reindeer kept in the other areas, such as Alaska, Russia and Finland, indicating that every rumen ciliate faunae in reindeer has high similarity to each other, and suggesting that these hosts have been isolated from the other ruminants for long time and established characteristic ciliate fauna. The ciliate density was estimated as 1.1-2.5 x 10 (6)/ml, which value was fairly higher than those in domestic ruminants. Surface structures of characteristic species were observed by SEM.     

Connective tissue-type mast cell leukemia in a dog

An unusual case diagnosed as connective tissue-type mast cell leukemia with marked mastocyte infiltration into visceral organs in a seven-year-old female Curly-Coated retriever is presented. Acute circulatory collapse, emesis, diarrhea, abdominal enlargement, icterus, cyanosis, dyspnea, pulmonary edema, hepatomegary, ascites, and right ventricular enlargement were observed. Hematologic and biochemical examinations revealed mast cell leukemia, mature neutrophilia, monocytosis, thrombocytopenia, hemolytic hyperbilirubinemia, hyperhistaminemia, renal and hepatic injuries. Mast cells were distributed systemically, but predominantly in the diaphragm and liver with a large mass among the serosa of ileum, cecum and colon. Mast cells were stained intensely by both safranin and berberine sulfate.     

Seroprevalence of Bartonella henselae and Toxoplasma gondii among healthy individuals in Thailand

The seroprevalence of Bartonella henselae and Toxoplasma gondii among apparently healthy individuals, mainly blood donors, in Thailand was investigated by an indirect fluorescent antibody technique and by a latex agglutination test, respectively. Of 163 serum samples examined, 9 (5.5%) were found to be positive for B. henselae-IgG, 2 (1.2%) for B. henselae-IgM, and 5 (3.1%) for the T. gondii antibody. No significant difference was observed between male and female samples in the serological test with either B. henselae or T. gondii. The age of individuals with B. henselae-IgG was distributed from the 20s to the 70s, and B. henselae-IgM was found in the individuals of the 30s and 60s. The age of T. gondii positive samples ranged from the 20s to the 60s. In this study, the prevalence of B. henselae infection among healthy individuals in Thailand was serologically demonstrated for the first time.     

Neospora caninum infected the alimentary tract of nude mice and was transmitted to other mice by intraperitoneal inoculation with the intestinal contents

Neospora caninum (BT-2 strain) that originated from the brain of a Holstein calf was serially passaged through 10 generations of BALB/c nude mice by intraperitoneal inoculation. Histological examination of the mice revealed that numerous clusters of tachyzoites appeared in the pancreas, stomach and small intestine as well as in the central nervous system (CNS) and skeletal muscles. Intestinal contents of the infected mice were inoculated intraperitoneally into uninfected nude mice and 3 of the 17 inoculated mice showed clinical signs at post inoculation days 3 to 10. The present experiments demonstrated a proliferation of N. caninum tachyzoites in the mucosa of the alimentary tract and pancreas of the nude mice and the intestinal contents of the mice were infective to other nude mice.     

Adaptive immune response of Vgamma2Vdelta2+ T cells during mycobacterial infections

To examine the role of T cell receptor (TCR) in gammadelta T cells in adaptive immunity, a macaque model was used to follow Vgamma2Vdelta2+ T cell responses to mycobacterial infections. These phosphoantigen-specific gammadelta T cells displayed major expansion during Mycobacterium bovis Bacille Calmette-Guérin (BCG) infection and a clear memory-type response after BCG reinfection. Primary and recall expansions of Vgamma2Vdelta2+ T cells were also seen during Mycobacterium tuberculosis infection of naive and BCG-vaccinated macaques, respectively. This capacity to rapidly expand coincided with a clearance of BCG bacteremia and immunity to fatal tuberculosis in BCG-vaccinated macaques. Thus, Vgamma2Vdelta2+ T cells may contribute to adaptive immunity to mycobacterial infections.     

An LRR receptor kinase involved in perception of a peptide plant hormone,phytosulfokine

The sulfated peptide phytosulfokine (PSK) is an intercellular signal that plays a key role in cellular dedifferentiation and proliferation in plants. Using ligand-based affinity chromatography, we purified a 120-kilodalton membrane protein, specifically interacting with PSK, from carrot microsomal fractions. The corresponding complementary DNA encodes a 1021-amino acid receptor kinase that contains extracellular leucine-rich repeats, a single transmembrane domain, and a cytoplasmic kinase domain. Overexpression of this receptor kinase in carrot cells caused enhanced callus growth in response to PSK and a substantial increase in the number of tritium-labeled PSK binding sites, suggesting that PSK and this receptor kinase act as a ligand-receptor pair.