试论生态分类系统在我国天然林保护与经营中的应用

我国林业的发展正面临前所未有的机遇和挑战,现有资料表明,一方面,我国林业的宏观政策以及森林的采伐更新过程缺乏基本生态学原理的支持;另一方面,仅研究生态学理论还不够,还要研究生态学理论转化为生产力的工具,生产态分类系统是确定、描述和纵制生态系统类型图的方法。应用这种多层次系统的目的是用图的形式是把森景观的生物和环境特征抽象化,综合化、标准化和整体化,以实现生态系统管理的目标。通过纵绘制各种景观特征、林业人员可以根据土地承载力及适应性 确定森林的经营方向和经营措施,生态分类系统在吉林省东部针阔混交林区试验应用。     

Neuroprotection by methanol extract of Uncaria rhynchophylla against global cerebral ischemia in rats

In traditional Oriental medicine, Uncaria rhynchophylla has been used to lower blood pressure and to relieve various neurological symptoms. However, scientific evidence related to its effectiveness or precise modes of action has not been available. Thus, in the current study, we evaluated neuroprotective effects of U. rhynchophylla after transient global ischemia using 4-vessel occlusion model in rats. Methanol extract of U. rhynchophylla administered intraperitoneally (100-1000 mg/kg at 0 and 90 min after reperfusion) significantly protected hippocampal CA1 neurons against 10 min transient forebrain ischemia. Measurement of neuronal cell density in CA1 region at 7 days after ischemia by Nissl staining revealed more than 70% protection in U. rhynchophylla-treated rats compared to saline-treated animals. In U. rhynchophylla-treated animals, induction of cyclooxygenase-2 in hippocampus at 24 hr after ischemia was significantly inhibited at both mRNA and protein levels. Furthermore, U. rhynchophylla extract inhibited TNF-alpha and nitric oxide production in BV-2 mouse microglial cells in vitro. These anti-inflammatory actions of U. rhynchophylla extract may contribute to its neuroprotective effects.     

Effect of vaccinations with recombinant fusion proteins on Ancylostoma caninum habitat selection in the canine intestine

Laboratory dogs were vaccinated subcutaneously with 3 different recombinant fusion proteins, each precipitated with alum or calcium phosphate. The vaccinated dogs were then challenged orally with 400 third-stage infective larvae (L3) of the canine hookworm, Ancylostoma caninum. The 3 A. caninum antigens selected were Ac-TMP, an adult-specific secreted tissue inhibitor of metalloproteases; Ac-AP, an adult-specific secreted factor Xa serine protease inhibitor anticoagulant; and Ac-ARR-1, a cathepsin D-like aspartic protease. Each of the 3 groups comprised 6 male beagles (8 +/- 1 wk of age). A fourth group comprised control dogs injected with alum. All of the dogs vaccinated with Ac-TMP or Ac-APR-1 exhibited a vigorous antigen-specific antibody response, whereas only a single dog vaccinated with Ac-AP developed an antibody response. Dogs with circulating antibody responses exhibited 4.5-18% reduction in the numbers of adult hookworms recovered from the small intestines at necropsy, relative to alum-injected dogs. In contrast, there was a concomitant increase in the number of adult hookworms recovered from the colon. The increase in colonic hookworms was as high as 500%, relative to alum-injected dogs. Female adult hookworms were more likely to migrate into the colon than were males. Anti-enzyme and anti-enzyme inhibitor antibodies correlated with an alteration in adult hookworm habitat selection in the canine gastroinntestinal tract.     

Distribution of mating type alleles in the wheat pathogen Mycosphaerella graminicola over spatial scales from lesions to continents

A total of 2035 Mycosphaerella graminicola strains collected from 16 geographic locations on four continents were assayed for the mating type locus. RFLP fingerprints were used to identify clones in each population. At the smallest spatial scale analyzed, both mating types were found among fungal strains sampled from different lesions of the same leaf as well as from different pycnidia in the same lesion. At larger spatial scales, the two mating types were found at equal frequencies across spatial scales ranging from several square meters to several thousand square kilometers. Though the absolute frequencies of the two mating types sometimes varied for different sampling units within the same spatial scale in the hierarchy (plots within a field, fields within a country, or different continents of the world), none of the differences were statistically significant from the null hypothesis of equal frequencies for the two mating types. The evolutionary forces likely to maintain the even distribution of the two mating types in this pathogen were discussed.     

Endoenzymes associated with haemocyte types in the scallop (Chlamys farreri)

Haemocyte types of the scallop (Chlamys farreri) were identified by Giemsa stain and flow cytometry (FCM). Additionally, the activities of peroxidase (POD), phenoloxidase (PO) and alkaline phosphatase (ALP) in haemocytes were analysed by immunocytochemical and biochemical methods. The results indicate that there were two types of haemocytes in the scallop, hyalinocytes and granulocytes, and that POD, PO and ALP were more abundant and more active in granulocytes than in hyalinocytes.     

A data review and re-assessment of ovarian cancer serum proteomic profiling

Background

The early detection of ovarian cancer has the potential to dramatically reduce mortality. Recently, the use of mass spectrometry to develop profiles of patient serum proteins, combined with advanced data mining algorithms has been reported as a promising method to achieve this goal. In this report, we analyze the Ovarian Dataset 8-7-02 downloaded from the Clinical Proteomics Program Databank website, using nonparametric statistics and stepwise discriminant analysis to develop rules to diagnose patients, as well as to understand general patterns in the data that may guide future research.

Results

The mass spectrometry serum profiles derived from cancer and controls exhibited numerous statistical differences. For example, use of the Wilcoxon test in comparing the intensity at each of the 15,154 mass to charge (M/Z) values between the cancer and controls, resulted in the detection of 3,591 M/Z values whose intensities differed by a p-value of 10^-6 or less. The region containing the M/Z values of greatest statistical difference between cancer and controls occurred at M/Z values less than 500. For example the M/Z values of 2.7921478 and 245.53704 could be used to significantly separate the cancer from control groups. Three other sets of M/Z values were developed using a training set that could distinguish between cancer and control subjects in a test set with 100% sensitivity and specificity.

Conclusion

The ability to discriminate between cancer and control subjects based on the M/Z values of 2.7921478 and 245.53704 reveals the existence of a significant non-biologic experimental bias between these two groups. This bias may invalidate attempts to use this dataset to find patterns of reproducible diagnostic value. To minimize false discovery, results using mass spectrometry and data mining algorithms should be carefully reviewed and benchmarked with routine statistical methods.

     

Authentic and recombinant bilirubin oxidases are in different resting forms

Myrothecium verrucaria bilirubin oxidase expressed in Aspergillus oryzae is in a resting form different from that of the authentic bilirubin oxidase, but reaches the resting form of the authentic enzyme after one cycle of reduction and reoxidation with dioxygen as shown by the absorption and electron paramagnetic resonance spectra.