Vascular Leakage Through Intraendothelial Channels Induced by Cholera Toxin in the Skin of Guinea Pigs

Guinea pigs were injected intravenously with Evans blue solution ½, 1, 5 and 22 hours after intradermal injection of Vibrio cholerae 569B toxin. Then they were fixed by perfusion with diluted Karnovsky's aldehyde mixture 1½, 5, 10, 15 and 90 minutes later. In some cases, horseradish peroxidase was mixed in the dye solution, and chopped tissue slices were incubated histochemically. Dermal blood vessels from these samples were examined under the electron microscope. The fine structure of the endothelial junctions remained unchanged as compared with controls. However, extended rough surfaced endoplasmic reticulum was observed in the endothelial cells at 30 minutes after the toxin injection, when cutaneous bluing was not marked yet. At 22 hours after toxin injection, endothelial perikarya were filled with prominent Golgi complexes, multivesicular bodies and systems of caveolae and vesicles which coalesced, forming intraendothelial channels after diaphragms disappeared. Endothelial fenestrae were numerous in the attenuated portions.     

Platelet Kinetics in Canine Ehrlichiosis: Evidence for Increased Platelet Destruction as the Cause of Thrombocytopenia

A significant (P < 0.025) increase in the mean platelet diameter occurred in five Ehrlichia canis-infected dogs when platelet numbers decreased to 100,000/mul or less. Maximal incorporation of [(75)Se]selenomethionine into platelets of six uninfected dogs was 0.080 +/- 0.019% (mean +/- standard error) and occurred 5 to 6 days after dosage, whereas maximal incorporation was 0.036 +/- 0.004% within 2 to 3 days after dosage in seven chronically infected dogs that had thrombocytopenia. Analysis of the [(75)Se]selenomethionine curves yielded a platelet lifespan of 9 days in uninfected dogs versus 4 days in chronically infected dogs. Thus, megakaryocyte maturation and/or platelet release occurred at an accelerated rate in infected dogs, whereas increased destruction of newly produced labeled platelets diminished their number of peripheral blood. [(51)Cr]sodium chromate-labeled platelet survival was exponential, with a half-life of approximately 1 day in two dogs at 2 to 4 days postinfection and three chronically infected dogs. Platelet survival time was 8 days and rectilinear in four uninfected dogs. Platelet recovery was 39.43 +/- 2.86% in infected dogs as compared with 68.2 +/- 10.72% in uninfected dogs. Whole-body scans of one dog prior to and 7 days after infection showed that labeled platelets were destroyed primarily in the spleen. It is concluded that the thrombocytopenia in E. canis-infected dogs is the result of increased platelet destruction which begins within a few days after infection.     

Vestibular Influences on Postural Instability Induced by Movements of the Visual Environment and Support

Subjects were maintained in a vertical posture standing on a hard support with a limited degree of freedom in the frontal plane. The stability of the vertical posture was assessed on the basis of the standard deviations (σ) from the mean amplitude of head oscillations (in the frontal and sagittal planes) relative to the origin of the coordinate system. Sinusoidal rotations of the optokinetic cylinder in which subjects stood, sinusoidal rotations of the support, and combination of these rotations, with phase discordance between movements of the cylinder and the support, led to increases in σ in all subjects. Feedback via the vestibular input was created using transmastoid galvanic vestibular stimulation. Changes in the feedback current showed a linear function relating to the amplitude and speed of head movement. Introduction of variations in the feedback function could be used to decrease σ for lateral oscillations; increases (compared with values on calm standing in the dark) resulted from the use of any of the destabilizing treatments. Changes in σ for oscillations in the sagittal plane were not systematic. __________ Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 91, No. 3, pp. 246–258, March, 2005.     

Role of Biological Mimicry in the Pathogenesis of Rat Arthritis Induced by Mycoplasma arthritidis

Complement fixation (CF), immunofluorescence, and agar gel double-diffusion tests were used to demonstrate an antigenic relationship between rat tissues and Mycoplasma arthritidis. Rabbit antisera against six strains of M. arthritidis exhibited positive reactions in the CF test with an ethyl alcohol-saline extract of rat muscle, whereas only 6 of 18 antisera against other Mycoplasma species were positive. With the use of gel diffusion techniques, absorption of various M. arthritidis antigens with antiserum against rat muscle removed at least one precipitin band when the absorbed mycoplasma antigens were reacted against homologous antisera. Rabbit antiserum against M. arthritidis was conjugated with fluorescein isothiocyanate and reacted against frozen sections of muscle tissues of various animals. As controls, unlabeled normal rabbit serum and rabbit anti-M. arthritidis serum were included to determine the specificity of the reaction. Rat, hamster, and mouse skeletal muscle exhibited specific fluorescence, whereas chicken, beef, frog, and turtle muscles exhibited no specific fluorescence. Mice injected at birth with rat lymphocytes were found to be more susceptible to subsequent infection by M. arthritidis than were normal mice or mice injected at birth with mouse lymphocytes. These results indicate the occurrence of a heterogenetic antigen(s) common to M. arthritidis and rat tissues. Preliminary evidence suggests that this heterogenetic antigen(s) may enable the mycoplasmas to become established in their host.     

Tamm－Horsfall蛋白糖基组分的致肾炎作用

我们在体外试验中证实：Ｔａｍｍ－Ｈｏｒｓｆａｌｌ蛋白（ＴＨＰ）刺激人单核细胞产生肿瘤坏死因子和ＩＬ－１的作用依赖其糖基组分的完整。为了探讨糖基组分在ＴＨｐ所致肾小管间质肾炎（ＴＩＮ）发病机制中的作用。我们给Ｗｉｓｔａｒ大鼠肾内直接注射ＴＨＰ制成ＴＩＮ模型。该模型在发病第４ｄ即有明显的肾间质巨噬细胞（ＭΦ）浸润。用高碘酸氢化去除ＴＨＰ的糖基组分明显破坏了ＴＨＰ诱发ＴＩＮ的能力。注射去糖基ＴＨＰ的动物只有轻微的组织学和超微结构改变。肾间质浸润的ＭΦ数量明显减少，亦无肾小管功能障碍。由此表明：ＴＨＰ的糖基组分在其导致ＴＩＮ的发生、发展中具有关键作用。     

Smoothelin在氯化镉致16HBE细胞损伤中的作用

目的 研究氯化镉致16HBE细胞损伤后smoothelin基因mRNA表达变化,探讨SMTN在镉致细胞损伤中的作用.方法 分别用10、20、30、40 μmol/L CdCl2 处理16HBE细胞24 h,用30 μmol/L CdCl2处理16HBE细胞12、24、48和72 h,利用MTT法检测细胞存活率,qRT-PCR法检测细胞SMTN基因表达变化.结果 与CdCl2浓度为0 μmol/L对照组相比,10、20、30、40 μmol/L组细胞存活率分别为(84.2±9.7) %、(54.6±6.0) %、(30.2±2.9)%、(10.9±2.1) %,皆有显著性差异(P<0.01);而20、30、40 μmol/L组细胞SMTN mRNA相对表达分别2.943±0.212,10.602±1.330,43.782±4.571,与CdCl2浓度为0 μmol/L对照组比较有显著性差异(P<0.01),且随着CdCl2染毒剂量的上升,SMTN表达逐渐升高.与CdCl2浓度为0 μmol/L对照组比较,30 μmol/L CdCl2处理16HBE细胞12、24、48和72 h,细胞生存率分别为(76.3±7.2) %,(35.2±4.0) %,(18.8±2.1) %,(7.0±0.9) %,有显著性差异(P<0.01),12、24、48和72 h处理细胞SMTN mRNA相对表达分别为11.419±1.441,12.030±1.402,10.420±1.114,8.953±0.987,有显著性差异(P<0.01).结论 SMTN mRNA在氯化镉处理细胞中表达明显升高,有明显的剂量-反应关系,可能在镉致细胞死亡或凋亡中发挥作用.     

Tubular complexes as a source for islet neogenesis in the pancreas of diabetes-prone BB rats

Tubular complexes (TC) in the pancreas contain duct-like structures with low cuboidal or flattened cells surrounding a large lumen and are thought to be a response to pancreatic injury. TC have been studied in animal models of chemical or surgically induced pancreatic damage but their occurrence has not been reported in rodent models of spontaneous autoimmune type I diabetes. We hypothesized that TC would be increased during the active phase of islet destruction in autoimmune diabetes and could contain islet progenitor cells. We analyzed TC in pancreas of Wistar Furth (WF), control (BBc) and diabetes-prone BioBreeding (BBdp) rats using immunohistochemistry and morphometry. TC were observed in all rat strains during active pancreas remodeling ( approximately 13 days). They increased between 60 and 93 days only in BBdp rats coincident with the increase in diabetes cases. Most TC were infiltrated with CD3(+) T-cells. Duct-like cells in the TC had low expression of the exocrine marker amylase, increased expression of epithelial cell markers, keratin and vimentin, and remarkably high cell proliferation and cell death. TC islets contained cells stained positive for insulin, glucagon, somatostatin, pancreatic polypeptide, as well as PDX-1, chromogranin, and hepatocyte-derived growth factor receptor, c-met. Transitional cells that were keratin(+)/insulin(+) and keratin(+)/amylase(+) cells were present in TC. The stem cell marker, nestin was upregulated in the TC region. Duct-like cells in TC of BBdp rats expressed markers of committed endocrine precursors: PDX-1, neurogenin 3 and protein gene product 9.5. This study demonstrates that TC are upregulated during beta-cell destruction and contain potential endocrine progenitors.     

Evidence against a Role for Neutrophils in the Clearance of Small Immune Complexes

The activation of human neutrophils (PMN) by immune complexes (IC) consisting of tetanus toxoid and the corresponding human antibodies was studied by varying IC properties like size, antigen: antibody ratio, Fc density, etc. While Ag: ab ratio seemed to have some importance, especially when complement activation was allowed, size appeared to be the decisive factor. Surprisingly, good stimulation of PMN was obtained only with very large IC and no plateau was reached with increasing size. PMN activation even by these very large complexes was inhibited in the presence of physiological IgG concentrations, but only if complement was omitted. Generation of IC in the presence of serum, on the other hand, prevented the formation of IC sufficiently large for PMN activation. Finally, in an IC clearance experiment in mice using ¹²⁵I-labelled human serum albumin and mouse antibody, no radioactivity was found associated with blood PMN in spite of a rapid clearance. It is concluded that PMN are probably not involved in the physiological clearance of IC if these are considerably smaller than opsonized microorganisms.     

Mechanism of B-Lymphocyte Activation: Failure to Obtain Evidence of a Direct Role of the Ig Receptors in the Triggering Process

Experiments were designed to test two hypotheses of B-cell activation by antigen: the cross-linking concept, postulating that a suitable degree of antigen-induced cross-linking of the Ig receptors is sufficient for immunocyte triggering, and the two-signal hypothesis, suggesting that a first signal delivered by antigen interacting with the Ig receptors followed by a second signal given by, for example, a polyclonal B-cell activator is necessary for activation. The results did not support either of these hypotheses. Thus, the hapten FITC coupled to human serum albumin and human gammaglobulin in different conjugation ratios failed to activate B cells, whether the hapten-protein conjugates were soluble or precipitated, whether the experiments were carried out in the presence or absence of different concentrations of sera from different species, and irrespective of the day of assay. Furthermore, the same FITC-protein conjugates or FITC itself coupled to Sepharose particles failed to induce a specific anti-FITC response, even though a range of 10-9-fold concentrations of FITC were used. In contrast, FITC coupled to lipopolysaccharide (LPS) regularly induced a primary anti-FITC response in all the above systems, whether FITC-LPS was soluble or coupled to Sepharose particles. The conjugation ratio of FITC to LPS was within the range of epitope densities used with FITC-protein conjugates. Analogous studies were performed with the above compounds and, in addition, NNP-cap and fowl gammaglobulin, added alone or together with LPS to lymphocyte cultures. In no case did the antigen plus LPS give a better specific anti-FITC response than LPS alone, irrespective of the culture conditions, the epitope densities, the physical form of the conjugates, and whether they were bound to Sepharose particles or not, although this would be expected in terms of the two-signal concept. The results are compatible with the one nonspecific signal hypothesis, ascribing a passive role to the Ig receptors and an active triggering function to thymus-independent antigens. Therefore, the ability to trigger B cells directly will depend on the nature of the carrier, triggering being achieved if the carrier is a polyclonal B-cell activator; the epitope density and the degree of cross-linking of Ig receptors are unimportant for delivering the triggering signal, although they can facilitate the binding of the conjugate to the specific B cells.     

Allergy to Storage Mites or Cow Dander as a Cause of Rhinitis among Finnish Dairy Farmers

The role of storage mites Acarus siro, Lepidoglyphus destructor, and Tyrophagus putrescentiae, compared with that of cow dander, as a cause of allergic rhinitis was studied by nasal challenges in a population of 106 non-smoking dairy farmers. Thirty-six of the subjects were challenged with storage mites alone, each with only one of the three species in consecutive order, 43 with cow dander alone, and 27 with both. Thus mite challenges were performed on 63 farmers and cow dander challenges on 70. Challenges with any one of the storage mite species were positive in 18% and with cow dander in 20% of farmers with allergic rhinitis. All challenges to asymptomatic farmers were negative. Five of the eight positive reactions to storage mites were due to Lepidoglyphus destructor, and three to Tyrophagus putrescentiae. Acarus siro was not responsible for any of the positive reactions. The results indicate that, among dairy farmers, storage mites are as common as cow dander as a cause of allergic occupational rhinitis.     

The Psychotherapist as a Neglected Variable in Psychotherapy: An Illustration by Reference to the Role of Therapist Experience and Training

Over the past two decades, research has turned its attention from studies of therapist and patient traits to studies of manualized therapy models and technical procedures. Randomized clinical trials designs, while making many contributions to understanding psychotherapy and even increasing the available evidence of its efficacy, have not adequately addressed the unique contributions of patient and therapist characteristics. Indeed, in some ways, the adoption of randomized clinical trials as the "gold standard" of research methodology may have inadvertently obscured the roles of therapist and patient variables in effective psychotherapy. This article uses therapist experience and training as examples of variables whose contributions cannot be assessed by using diagnosis as a standard of patient uniformity or manual adherence as a standard of therapy purity.