Effect of peroral immunization of humans with Streptococcus mutans on induction of salivary and serum antibodies and inhibition of experimental infection

Naturally occurring antibodies reactive with Streptococcus mutans whole cells were assayed in whole saliva, parotid saliva, and blood samples collected from eight human volunteers. The levels and serotypes of indigenous S. mutans in plaque and whole saliva samples were also determined. After baseline sampling the teeth were cleaned and the subjects were inoculated with streptomycin-resistant S. mutans strains Ingbritt (serotype c) and OMZ65 (serotype g). The level of implantation and duration of colonization were determined in plaque and saliva, and antibodies reactive with these strains were monitored in saliva and serum. After the implanted bacteria were shed, the subjects wee immunized by the daily ingestion of an enteric-coated capsule containing 25 mg of Formalin-killed, freeze-dried OMZ65 cells for 3 days and inoculation was repeated. The levels of antibodies and of implantation and the duration of colonization were monitored as before. One month after the bacteria could no longer be detected, the immunization and inoculation cycle was repeated except that the subjects were immunized for 7 days. Five of the eight subjects were successfully colonized by strains Ingbritt and OMZ65. The remaining three did not become colonized with either strain. Strain OMZ65 implanted at a higher level than did strain Ingbritt. Oral immunization did not result in a detectable antibody response in saliva or serum to whole bacterial cells. However, after both the first and second immunizations there were marked reductions in the peak levels of infection and the duration of colonization of both OMZ65 and Ingbritt.     

Relationship between dose of methotrexate, apoptosis, p53/p21 expression and intestinal crypt proliferation in the rat

Abstract Previous studies have shown that apoptosis is induced by cytotoxic chemotherapy and precedes hypoproliferation of intestinal crypt cells. However, the relationship between the degree of intestinal apoptosis and crypt cell hypoproliferation may not be directly related. The purpose of this study was to investigate the relationship between apoptosis and hypoproliferation with increasing doses of chemotherapy. Eleven groups of breast cancer-bearing DA rats were treated with two doses of methotrexate (MTX) i. m. at varying concentrations (0.5, 1.5, 2.5 and 5.0 mg/kg) or saline (control). Animals were killed at 6 or 24 h following treatment. The small and large intestines were examined for apoptosis, villous area (small intestine), crypt length and mitotic count per crypt. Immunohistochemical expression of p53 and p21^waf1/cip1 (p21) were examined quantitatively. Data were analysed using Peritz F-test. Low dose MTX (0.5 mg/kg) did not change p53 expression at 6 h but induced a 15-fold increase in apoptosis in the crypts of the small intestine. This was associated with only a minor reduction in crypt cell proliferation. Higher doses of MTX increased p53 expression and caused a lower (7-fold) but more prolonged peak of apoptosis that was accompanied by reduced villous area, shortened crypts and a more profound reduction in crypt cell proliferation. Unlike the small intestine, apoptosis in the colon was 10-fold lower, proportional to the dose of MTX and did not induce overt damage. Expression of p21 did not change with any dose at either timepoint. We conclude that apoptosis is not always associated with crypt cell hypoproliferation and that the small intestine can recover after low dose MTX despite a heightened peak of apoptosis of crypt cells.     

Unraveling human cancer in the mouse: recent refinements to modeling and analysis

The ability to manipulate the mouse genome has made the mouse the primary mammalian genetic model organism. It has been possible to model human cancer in the mouse by overexpressing oncogenes or inactivating tumor suppressor genes, and these experiments have provided much of our in vivo understanding of cancer. However, these transgenic approaches do not always completely and accurately model human carcinogenesis. Recent developments in transgenic and knockout approaches have improved the accuracy of modeling somatic cancer in the mouse and analyzing the genomic instability that occurs in murine tumors. It is possible to use retroviral gene delivery, chromosome engineering and inducible transgenes to selectively manipulate the genome in a more precise spatial and temporal pattern. In addition, the development of powerful cytogenetic tools such as spectral karyotyping, fluorescence in situ hybridization and comparative genome hybridization have improved our ability to detect chromosomal rearrangements. Finally, global patterns of gene expression can be determined by microarray analysis to decipher complex gene patterns which occur in cancers. Several of these advances in mouse modeling of human cancer are discussed in this review.     

Variations in food preference and consumption across the menstrual cycle

There is some evidence that food consumption changes across the menstrual cycle. However, archived studies tend to rely on self-report data and do not differentiate among types of food eaten. The present laboratory study was designed to measure women's taste preferences and specific food consumption across the menstrual cycle. Women came into the laboratory, consumed everyday foods, and rated them on taste judgment scales. The foods were weighed before and after the tasting session to determine amount eaten. After the tasting session, subjects completed several questionnaires (e.g., measures of affect, restrained eating, menstrual cycle and menstrual symptoms). Physical measurements (e.g., height, weight) were taken at the end of the session. Sweet food consumption and preference ratings were significantly higher during the premenstrual period. Consumption and ratings of other foods did not differ. There were no differences in levels of mood, obesity, or restrained eating across the menstrual cycle. Low restraint was associated with reporting fewer menstrual symptoms, in general, and slightly better mood. These results support the idea that specific taste preferences change over the menstrual cycle, and that endocrinological factors could be involved in this phenomenon.     

小巨核细胞免疫酶标染色在鉴别骨髓增生异常综合征和巨幼细胞贫血中的意义

①目的探讨小巨核细胞免疫酶标染色在鉴别骨髓增生异常综合征(MDS)和巨幼细胞贫血(MegA)中的意义.②方法采用碱性磷酸酶-抗碱性磷酸酶桥联免疫酶标(APAAP)法,对30例MDS和34例MegA病人骨髓涂片染色,观察巨核细胞阳性率并计数,并与33例正常骨髓进行比较.③结果小巨核细胞在MDS中的阳性率为93.3%,在MegA中的阳性率为23.8%,差异有极显著意义(x2=31.56,P＜0.01);二者均明显高于正常对照组(12.3%),差异有显著性(x2=48.94,13.69,P＜0.01).MDS中小巨核细胞数量为每片34个,MegA中小巨核细胞数量为每片4.8个,两者比较,差异有显著性(u=78.24,P＜0.01);两组与正常对照组(每片0.3个)比较,差异均有极显著性(u=648.56,432.78,P＜0.01).MDS中的小巨核细胞以淋巴样小巨核细胞、单圆核小巨核细胞为主;MegA中的小巨核细胞为单圆核、多核小巨核细胞,未见淋巴样小巨核细胞.④结论小巨核细胞免疫酶标染色在MDS和MegA的鉴别诊断中有重要意义.     

骶管阻滞配用周围神经阻滞治疗腰椎间盘突出症的疗效

[目的 ]探讨非手术方法治疗腰椎间盘突出症的疗效 .[方法 ]将 98例腰椎间盘突出症患者分成腰痛组和腿痛组 ,前者采用骶管阻滞加严氏椎间隙阻滞法 ,后者采用骶管阻滞加腰大肌肌沟阻滞法 .[结果 ]两组治疗前后分值相比较均有显著性差异 ,其优良率分别为 88%和 84% .[结论 ]采用骶管阻滞加严氏椎间隙阻滞或腰大肌肌沟阻滞法治疗腰椎间盘突出症具有疗效     

葛根素对兔脊髓缺血再灌注损伤的保护作用

目的：研究葛根素对兔脊髓缺血再灌注损伤的作用。方法：20只雄性新西兰大白兔随机分成缺血组（A组,n=10）及葛根素组（B组,n=10),夹闭腹主动脉肾下段20min,建立兔脊髓腰尾段血模型,B组于夹闭前10min静脉注射葛根素30mg.kg^-1,A组则静脉注射生理盐水,测定夹闭前、后及再灌注后血浆中丙二醛（MDA）浓度及超氧化物歧化酶（SOD)活性,再灌注4,8,12,24及48h分别对动物后肢运动功能评分;再灌注48h后,处死动物,制作切片,观察其组织病理变化。结果缺血及再灌注后B组MDA值明显低于A组（P＜0．05）,而OD活性明显高于A组（P＜0．05）;再灌注后4,8,12,24及48h时的神经功能评分B组明显高于A组（P＜0．05）;光镜下,与A组相比,B组脊髓组织损伤显著减轻,形态基本正常的前角细胞较多。结论葛根素对兔脊髓缺血再灌注损伤有显著的保护作用。     

愈肝汤对慢性乙肝患者脂质过氧化的影响

目的　探讨愈肝汤对慢性乙肝患者的脂质过氧化作用。方法　 43例慢性乙肝患者服愈肝汤治疗 3mo ,观察其治疗前后超氧化物歧化酶 (SOD)、谷胱甘肽过氧化物酶 (GSH -Px)活力和过氧化脂质(LPO)水平的变化 ,并与 38例健康对照组比较。结果　慢性乙肝患者SOD、GSH -Px活力降低 (P <0 .0 5 ) ,LPO水平升高 (P <0 .0 5 ) ;愈肝汤可升高SOD和GSH -Px酶活性 (P <0 .0 1) ,降低LPO水平 (P <0 .0 5 )。结论　愈肝汤对慢性乙肝患者有明显的抗脂质过氧化作用 ,这是其治疗慢性乙型肝炎、减轻肝细胞损伤的重要机理之一。