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The efficacy of six chemicals as selective male gametocideson perennial ryegrass plants was studied by making use of agenetic marker technique. In a preliminary screening experimenteach of the chemicals was used in five concentrations and infive treatments at several stages of development at or nearear emergence. Promising treatments from within this experimentwere assessed in more detail subsequently. In most treatmentsfemale fertility was impaired more than male fertility. In thetreatments in which the desired effect was found, i.e. malefertility was depressed appreciably more than female fertility,the differential gametocidal selectivity of the chemicals couldnot be considered distinct enough to merit application on afield scale. 相似文献
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45.
On the nature of sporogenesis in some aerobic bacteria 总被引:30,自引:0,他引:30
Washed vegetative cells of various species of aerobic spore-forming bacteria sporulate abundantly when shaken in distilled water in air. The spores thus formed possess the same heat resistance as spores formed in a complete growth medium. Various factors influencing sporogenesis in water are described. Glucose in low concentration completely suppresses sporogenesis under these conditions and the suppression is relieved by the presence of ammonia as an exogenous source of nitrogen. Various amino acid and purine antimetabolite analogues inhibit sporogenesis and their inhibitory effects are completely reversed by much smaller amounts of the corresponding metabolites. Sporogenesis is thus regarded as a de novo synthesis of spore proteins from preexisting endogenous (enzyme) proteins. Cells low in protein fail to sporulate and the capacity of the cell to adaptively attack maltose and trehalose is strongly interfered with after the cell is irreversibly committed to sporulation, but not before that. Evidence is advanced supporting the hypothesis that sporogenesis is an endogenous process which commences when the supply of exogenous energy and carbon is depleted. It utilizes low molecular weight nitrogenous substances liberated by the degradation of preexisting enzyme proteins of the vegetative cell. Sporogenesis and adaptive enzyme formation are regarded as competitive synthetic processes, both utilizing endogenous enzyme proteins. The events of sporogenesis suggest that this process may be an adaptive protein synthesis, analogous to adaptive enzyme synthesis. 相似文献
46.
Teng YK Verburg RJ Verpoort KN Diepenhorst GM Bajema IM van Tol MJ Jol-van der Zijde EC Toes RE Huizinga TW van Laar JM 《Arthritis research & therapy》2007,9(5):R106
In order to identify pathogenic correlates of refractory rheumatoid arthritis (RA), antibodies against anti-cyclic citrullinated
protein (ACPAs) were investigated in RA patients in whom the dysregulated immune system had been ablated by high-dose chemotherapy
(HDC) and autologous haematopoietic stem cell transplantation (HSCT). Six patients with refractory RA were extensively characterized
in terms of levels of total immunoglobulins, RA-specific autoantibodies (ACPAs and rheumatoid factor) and antibodies against
rubella, tetanus toxoid (TT) and phosphorylcholine before and after HDC plus HSCT. Additionally, the avidity of ACPAs was
measured before and after treatment and compared with the avidity of TT antibodies following repeated immunizations. Synovial
biopsies were obtained by arthroscopy before HDC plus HSCT, and analyzed by immunohistochemistry. In the three patients with
clinically long-lasting responses to HDC plus HSCT (median 423 days), significant reductions in ACPA-IgG levels after therapy
were observed (median level dropped from 215 to 34 arbitrary units/ml; P = 0.05). In contrast, stable ACPA-IgG levels were observed in three patients who relapsed shortly after HDC plus HSCT (median
of 67 days). Clinical responders had ACPA-IgG of lower avidity (r = 0.75; P = 0.08) and higher degree of inflammation histologically (r = 0.73; P = 0.09). Relapse (after 38 to 530 days) in all patients was preceded by rising levels of low avidity ACPA-IgG (after 30 to
388 days), in contrast to the stable titres of high avidity TT antibodies. In conclusion, humoral autoimmune responses were
differentially modulated by immunoablative therapy in patients with synovial inflammation and low avidity ACPA-IgG autoantibodies
as compared with patients with high levels of high avidity ACPA-IgG. The distinct clinical disease course after immunoablative
therapy based on levels and avidity of ACPA-IgG indicates that refractory RA is not a single disease entity. 相似文献
47.
EM Tazi I Lalya MF Tazi Y Ahellal H M'rabti H Errihani 《World journal of surgical oncology》2010,8(1):1-3
Goblet cell carcinoid of the large intestine is a rare neoplasm, usually located in ascending colon and rectum. A 60-year-old male patient underwent surgery after the diagnosis of acute abdomen. Exploratory laparotomy revealed perforation with a diameter of 1 cm at the site of the previously performed gastroenterostomy and dilatation of the right colic flexure, secondary to a solid obstructive mass located in the mid-portion of transverse colon. Histopathological investigation of the biopsies, taken from the gastroenterostomy site and the tumor, revealed mixed carcinoid-adenocarcinoma with carcinoid component, predominantly composed of goblet cells. Three cycles of FOLFOX-4 protocol was administered. Following respiratory distress secondary to pulmonary metastasis, the patient's condition deteriorated and subsequently died in the fourth postoperative month. Our aim with this paper is to point out that more cases should be reported for more effective diagnosis, histopathological study, clinical investigation, treatment and prognosis of this specific neoplasm. 相似文献
48.
Irene EM Bultink 《Arthritis research & therapy》2010,12(1):107
Cardiovascular disease (CVD) has been identified as a major contributor to morbidity and mortality in patients with systemic
lupus erythematosus (SLE). The etiology of premature CVD in SLE is supposed to have many factors, including traditional coronary
artery disease (CAD) risk factors, antiphospholipid antibodies, and metabolic and inflammatory factors. Despite the overwhelming
interest in CVD in SLE research, prospective studies evaluating risk factors for hard endpoints (that is, cardiovascular events)
are relatively scarce. The article by Gustafsson and colleagues suggests that prothrombotic factors play an important role
in SLE-related CVD and that the influence of traditional CAD risk factors might be limited. 相似文献
49.
Asymptotic calibration 总被引:5,自引:0,他引:5
50.
Polygalacturonase inhibiting protein (PGIP) is localized in plant cell walls and plays an important role both in pectic substance metabolism and in prevention of the penetration of phytopathogenic microorganisms. Apparently, PGIP is responsible for the specificity of cell--cell interactions during pollination or inoculation by fungi nonpathogenic for the particular plant. PGIPs from different plants share a basic common structure. They are rather thermostable glycoproteins enriched with leucine and contain about 20% carbohydrates; the molecular weight varies between 37-54 kD. The synthesis of PGIP is encoded by one gene, and its expression is stimulated by injury and fungal infection. The resistance of plant tissues to infection frequently correlates with PGIP expression and with inhibiting action on fungal PG. Thus, PGIP is believed to be useful for gene engineering to obtain transgenic plants resistant to fungal infection or retaining commercial value during storage. 相似文献