Analysis of effector T cells against the murine syngeneic tumor MethA in mice orally administered antitumor polysaccharide SPR-901

The growth of MethA tumor was significantly inhibited by oral administration of the -glucan SPR-901 in BALB/c (+/+) mice but not in nude mice. Mice treated orally with SPR-901 exhibited an augmentation of antigen-specific resistance against rechallenge with the tumor cells. The tumor-neutralizing activity of regional lymph node cells from MethA-bearing mice against the tumor was augmented by oral administration of SPR-901. The tumor-neutralizing activity of lymph node cells from SPR-901-treated mice mainly appeared in Lyt2+cells. Furthermore, lymphokine-activated killer activity of these cells was enhanced by administration of SPR-901. The antitumor effect of SPR-901 was abrogated in mice depleted of either L3T4+ or Lyt2+ cells, and in cyclosporin-A-treated mice. These results suggest that Lyt2+ cells are important effector cells in MethA-bearing mice orally adminstered SPR-901 and that functional exertion of both Lyt2+ and L3T4+T cells is necessary for the antitumor effect of orally administered SPR-901 in vivo.     

Diversity and distribution of hidden cultivable fungi associated with marine animals of Antarctica

In the present study, we surveyed the distribution and diversity of fungal assemblages associated with 10 species of marine animals from Antarctica. The collections yielded 83 taxa from 27 distinct genera, which were identified using molecular biology methods. The most abundant taxa were Cladosporium sp. 1, Debaryomyces hansenii, Glaciozyma martinii, Metschnikowia australis, Pseudogymnoascus destructans, Thelebolus cf. globosus, Pseudogymnoascus pannorum, Tolypocladium tundrense, Metschnikowia australis, and different Penicillium species. The diversity, richness, and dominance of fungal assemblages ranged among the host; however, in general, the fungal community, which was composed of endemic and cold-adapted cosmopolitan taxa distributed across the different sites of Antarctic Peninsula, displayed high diversity, richness, and dominance indices. Our results contribute to knowledge about fungal diversity in the marine environment across the Antarctic Peninsula and their phylogenetic relationships with species that occur in other cold, temperate, and tropical regions of the World. Additionally, despite their extreme habitats, marine Antarctic animals shelter cryptic and complex fungal assemblages represented by endemic and cosmopolitan cold-adapted taxa, which may represent interesting models to study different symbiotic associations between fungi and their animal hosts in the extreme conditions of Antarctica.     

Nymphs of the Oriental cockroach (Blatta orientalis) as passive vectors of causal agents of avian tuberculosis and paratuberculosis

The potential transmission of the causal agent of paratuberculosis Mycobacterium avium ssp. paratuberculosis and avian tuberculosis Mycobacterium avium ssp. avium (Actinomycetales: Mycobacteriaceae) by nymphs of the Oriental cockroach Blatta orientalis L. (Blattodea: Blattidae) was investigated by oral infection with mycobacterial suspensions and examination of their droppings and bodies. Both the subspecies of M. avium were isolated from droppings at 3 days post-infection and M. a. avium was found in homogenized bodies at 10 days post-infection. The identity of M. a. avium and M. a. paratuberculosis isolates was demonstrated by Restriction Fragment Length Polymorphism (RFLP) analysis. The M. a. avium isolate used as the inoculum and the isolates from the bodies and droppings of the nymphs were shown to be virulent in chickens. The results show that orally infected nymphs of B. orientalis can harbour and shed viable and virulent mycobacteria. This hazard should be considered in the implementation of control measures against mycobacterial infections of animals and humans, which should include destruction of all developmental stages of cockroaches and prevention of their access to materials that can be contaminated by mycobacteria.     

Anti-proliferation and apoptosis induced by a novel intestinal metabolite of ginseng saponin in human hepatocellular carcinoma cells

20-O-(beta-D-glucopyranosyl)-20(S)-protopanaxadiol (IH-901), a novel intestinal bacterial metabolite of ginseng protopanaxadiol saponins, is reported to induce apoptosis in a variety of cancer cells. We purified the compound and measured its in vitro anti-tumor activity. IH-901 inhibited cell growth of human hepatocellular carcinoma SMMC7721 cells in a dose- and time-dependent manner. We also found that IH-901 induced apoptotic cell death concurrent with cell cycle arrest in G0-G1 phase in SMMC7721 cells. At the molecular level, we show that IH-901 upregulates cytochrome c, p53, and Bax expression, and downregulates pro-caspase-3 and pro-caspase-9 expressions in a dose-dependent manner, while the levels of Bcl-2 and Bcl-X(L) were unchanged in IH-901-treated SMMC7721 cells. These results provide significant insight into the anticarcinogenic action of IH-901.     

Increased activity of brain and platelet monoamine oxidase in dementia of Alzheimer type

Two groups of patients with dementia of Alzheimer type were studied with respect to monoamine oxidase (MAO) activity. In one group of 11 patients MAO activity was determined in platelets and in the other group of 14 patients in the brain (hypothalamus, caudate nucleus, hippocampus and cortex gyrus cinguli) post mortem. The results were compared to controls matched for age and sex. Platelet MAO activity was significantly higher in patients with dementia of Alzheimer type compared to controls. Brain MAO-B activity but not MAO-A activity was significantly higher in the dementia group in hyppocampus and cortex gyrus cinguli. In the controls there were positive correlations for MAO-B activity with age in the four brain regions, but these correlations were absent in the dementia group. This could be explained by differences in age of onset of dementia and that the disease process does not develop homogeneously in different brains.     

Isolation and characterization of toluene-sensitive mutants from Pseudomonas putida IH-2000

Two toluene-sensitive mutants were generated from Pseudomonas putida IH-2000, the first known toluene-tolerant isolate, by Tn5 transposon mutagenesis. These mutants were unable to grow in the presence of toluene (log P_ow 2.8) but they could grow in medium overlaid with organic solvents having a log P_ow value higher than that of toluene such as p-xylene (log P_ow 3.1), cyclohexane (log P_ow 3.4) and n-hexane (log P_ow 3.9). The Tn5 transposable element knocked out a cyoB-like gene in one mutant and a cyoC-like gene in the other mutant. Seven open reading frames were found in a 5.5-kb region containing the cyoB- and cyoC-like genes of strain IH-2000. ORFs 3–7 showed significant identity to the cyoABCDE gene products of Escherichia coli, but ORFs 1 and 2 showed no significant homology to any protein reported so far. The growth patterns of the Tn5 mutants with the inactivated cyo-like gene were similar to that of the wild-type strain in the absence of organic solvents, although the doubling times were slightly longer than that of the wild-type strain. Our findings indicate that cyo is an important gene for toluene tolerance, although its role is still unclear.     

Transmitter deficits in Alzheimer's disease

The pattern of neurotransmitter pathway losses in Alzheimer's disease are reviewed. Deficits of the cholinergic pathway from the nucleus basalis, the noradrenergic pathway from the locus coeruleus and the serotoninergic pathway from the raphe nuclei are established. Cortical somatostatin interneurons are affected and dopaminergic neurons may be affected although these may be late or secondary phenomena in the disease process. Other neuronal systems, particularly in the hippocampus and temporal cortex, are also damaged. However, the disease is not one of generalised neuronal atrophy since some neurons are selectively spared. The established pathway-specific losses are discussed in relation to the clinical symptomatology and the pathology of the disorder. The biochemical and histological findings are compared with similar measurements made on tissues from other dementing disorders in an attempt to trace features common to dementias. Finally, as an addendum, a hypothesis is briefly outlined which attempts to explain the common features of the affected neurons and the pathogenesis of the disorder.     

Characterization and functional analysis of a pollen-specific gene st901 in Solanum tuberosum

A pollen-specific gene, sb401, which was isolated from a cDNA library of in vitro geminated pollen of the diploid potato species Solanum berthaultii, belongs to the class of genes expressed late during pollen development. Using sb401 as a probe, a pollen-specific gene st901 was isolated from the genomic library of a potato species Solanum tuberosum cv. Desiree. Sequencing and RT-PCR analysis showed that the st901 genomic gene is 2,889 bp long, contains three exons and two introns, and encodes a putative polypeptide of 217 residues. The predicted protein sequence contains four imperfect repeated motifs of V–V–E–K–K–N/E–E; the core sequence of the repeats (K–K–N/E–E) resembles a microtubule-binding domain of the microtubule-associated protein MAP1B from mouse. The examination of a promoter–reporter construct in transgenic potato plants revealed that the st901 is expressed exclusively in mature pollen grains, which is consistent with the results of Northern blot and RT-PCR. For analysis of the function of st901, transgenic plants harboring antisense copies of st901 cDNA driven by a native st901 promoter were generated. Suppression of st901 gene in potato resulted in aberrant pollen at maturation and pollen viability of transgenic plants ranged from 4.4 to 14.8%, while that of control plants were more than 90%. These results strongly suggest that st901 has an essential role in pollen development.The st901 gene sequence has been deposited in GenBank under accession number AY526087. Accession number for SB401 is X95984.1     

Germ cell proliferation and apoptosis during testicular regression in a seasonal breeding fish kept in captivity

Cell proliferation and apoptosis regulate germ cells stock and sperm production, eliminate anomalous gametes, and are essential parameters to consider in fish farming. Herein, spermatogenic activity as well as germ cell proliferation and apoptosis were assessed in Leporinus taeniatus, a seasonal breeding species from the São Francisco River basin, Brazil. Testes of 24 adult fishes from a farming station were sampled between December and July and processed for light and transmission electron microscopy and immunohistochemistry for PCNA and TUNEL assay. The gonadosomatic index and seminiferous tubule diameters presented higher values during the breeding season (December/January and February/March), and then significantly reduced during the regression and resting stages (April/May and June/July). Phagocytosis of spermatozoa by Sertoli cells was evident during gonadal regression, but a significant number (up to 30%) remained at the tubular lumen during the resting stage. A higher PCNA/TUNEL ratio occurred in the breeding period, leading to an elevated proportion (%) of spermatogonia (G_A and G_B) in resting. Moreover, a higher TUNEL/PCNA ratio indicates the contribution of apoptosis to the reduction of germ cells during testicular regression. Together, these results indicate a shift in the balance between cell proliferation and apoptosis that contributes to the regulation of the spermatogenic cycle and germ cells pool of L. taeniatus kept in captivity.     

稀有人参皂苷IH901酶法转化与制备研究

本研究利用酶制剂蜗牛酶,酶法转化三七二醇组皂苷制备稀有人参皂苷IH901,正交实验优化酶解条件,建立酶法转化工艺.结果表明:超声法提取三七总皂苷正交实验优化条件为用75%乙醇溶液,15倍溶剂用量,超声波提取210 min作为最佳条件,三七总皂苷得率为12.21%;酶法转化二醇组人参皂苷制备稀有人参皂苷IH901,正交实验优化的条件为物料比为6/1、反应时间9 h、反应温度为45℃、pH值为3.0,酶解得率为54.24%;经硅胶柱分离获得IH901单体化合物,HPLC测定纯度达98%.酶法转化制备皂苷IH901的工艺方法简便,切实可行,可为中试生产提供参考.