Transforming growth factor beta (TGF-beta), a potent inhibitor of erythropoiesis: neutralizing TGF-beta antibodies show erythropoietin as a potent stimulator of murine burst-forming unit erythroid colony formation in the absence of a burst-promoting activity

Transforming growth factor beta (TGF-beta) is a bifunctional regulator of the growth of myeloid progenitors and is here demonstrated to directly inhibit the growth of primitive erythroid progenitors by 95% to 100% regardless of the cytokines stimulating growth. Autocrine TGF- beta production of primitive hematopoietic progenitors has previously been reported. In the present study, a neutralizing TGF-beta antibody (anti-TGF-beta) added to serum-containing cultures, resulted in a 3-, 4- , and 25-fold increase in burst-forming unit erythroid (BFU-E) colony formation in response to interleukin-4 (IL-4) plus erythropoietin (Epo), SCF plus Epo, and IL-11 plus Epo, respectively. The growth of BFU-E progenitors has been suggested to require a burst-promoting activity in addition to Epo. Accordingly, we observed no BFU-E colony formation in serum-containing cultures in response to Epo alone. In contrast, 50 BFU-E colonies were formed when anti-TGF-beta was included in the culture. In serum-free cultures, Epo also stimulated BFU-E colony formation in the absence of other cytokines, whereas anti-TGF- beta had no effect on the number of colonies formed. Quantitation of TGF-beta 1 in serum by an enzyme-linked immunosorbent assay method showed predominantly the presence of precursor (latent) TGF-beta 1, but also showed active TGF-beta 1 at a concentration sufficient to potently inhibit erythroid colony formation. Thus, neutralization of active TGF- beta 1 in serum shows that Epo alone is sufficient to stimulate the growth of murine BFU-E progenitors.     

Fluorescent in vivo tracking of hematopoietic cells. Part I. Technical considerations

We report a new technology for in vivo tracking of hematopoietic cells, using fluorescent lipophilic probes. Because the probe is irreversibly bound in the lipids of the cell membrane; substantial numbers of dye molecules can be incorporated per cell and thus substantial signal to noise can be achieved. Although this technology can be used for all hematopoietic cells, these first findings are reported on red blood cells (RBCs) owing to the importance of the membrane to RBC function and integrity. We demonstrated that labeling 10% of the RBCs of a rabbit and reinjecting them into the animal makes possible the tracking of these cells at various times after injection. Furthermore, the labeling appears not to affect in vivo cell lifetime or cellular volume changes in response to hypotonic shock. The single cell fluorescence intensity of the labeled RBCs remains relatively constant for 60 days, and an immune response appears not to be generated against labeled cells. That labeled RBCs have lifetime kinetics in vivo, as shown in other studies, indicates that the membranes are functioning normally and are unaltered by the labeling technology. The technology we present is also applicable to white blood cells, bone marrow, and platelets.     

Detection of non-A, non-B hepatitis antigen by immunocytochemical staining.

Liver tissue obtained from a chimpanzee during the acute phase of an experimental non-A, non-B (NANB) hepatitis virus infection was studied by a sensitive immunocytochemical staining procedure for the presence of NANB viral antigens. Initial investigations were conducted with a model system of hepatitis B virus (HBV) antigens for purposes of comparing two immunocytochemical staining methods. Of these two procedures, an immunoperoxidase procedure, utilizing an avidin-biotinylated enzyme complex, was at least 40-fold more sensitive than a conventional immunoperoxidase technique for the detection of HBV-specific tissue antigens. Utilization of the avidin-biotin-amplified immunoperoxidase staining procedure, in conjunction with four primary convalescent antisera obtained from NANB hepatitis-implicated donors, resulted in the observation of NANB virus-associated antigen in the cytoplasm of hepatocytes from an infected chimpanzee liver. These same human antisera were not reactive with a number of uninfected control cells nor with cells infected with HBV, hepatitis A virus, or cytomegalovirus. Preincubation of one of these convalescent NANB sera, or IgG derived thereof, with an acute-phase serum obtained from a NANB hepatitis virus-infected chimpanzee abolished the antibody reactivity. We conclude from these observations that selected convalescent sera from NANB hepatitis virus-infected patients contain low levels of antibody that specifically react with a cytoplasmic antigen associated with NANB virus-infected hepatocytes.     

肺应力和应变在肺损伤家猪机械通气中的作用

目的 研究不同平台压参数设置下,急性肺损伤(acute lung injury, ALI)家猪的跨肺压(transpulmonary pressure)等呼吸力学参数,明确平台压30cmH₂O能否全面准确反应ARDS呼吸力学情况。方法 将6只健康家猪麻醉、进行外科手术后,按照以下不同实验状态进行机械通气: A组平台压＜30cmH₂O、B组平台压＞30cmH₂O伴腹内高压(intra-abdominal hypertension, IAH)。观察不同分组通气参数设置下,肺应力、平台压等呼吸力学标。结果呼吸力学: A组肺应力为(15.07±1.47)cmH₂O高于 B组(10.92±1.28)cmH₂O;B组胸壁弹性阻力与呼吸系统弹性阻力之比(Ecw/Ers)为(0.36±0.06)高于A组(0.24±0.05);B组肺顺应性(Cdyn)为(13.38±2.79)ml/cmH₂O,明显高于A组(10.26±1.18)ml/cmH₂O ;差异均有统计学意义(P<0.01)。B组胸壁顺应性(Ccw)为(43.12±8.00)ml/cmH₂O,低于A组(63.28±36.71)ml/cmH₂O,差异均有统计学意义(P<0.01)。结论 单纯以平台压30cmH₂O作为机械通气的标准,不能准确地反映ARDS患者肺部的呼吸力学。腹内高压时,需要更高的平台压来改善氧合状况。肺应力和应变是真正反应ARDS肺呼吸力学的指标,将肺应力和应变理论引入临床,有利于为ARDS患者制定更加安全、合理的通气策略。     

Selenoprotein levels in patients with colorectal adenomas and cancer

OBJECTIVES: Selenium is a trace mineral that, as a constituent of certain selenoproteins, acts as an antioxidant. Results of studies addressing a cancer protective effect of selenium have been controversial. The present study measured selenoprotein-P, extracellular glutathione peroxidase, and plasma selenium in patients with colon cancer and adenomatous colon polyps to determine whether patients who develop colorectal adenomas or cancer are selenium deficient. METHODS: Patients who presented to an endoscopy center for colonoscopy or who were referred to our institution with a newly diagnosed colorectal cancer were offered enrollment in the trial. Each patient underwent phlebotomy, usually immediately after colonoscopy. In all, 103 patients were enrolled in the study. Of these, 33 patients were found to have colorectal cancer, 35 adenomatous colon polyps, and 17 normal examinations. A total of 18 patients had other diagnoses and were not included in the study group. RESULTS: The mean age for the colorectal cancer group was 69 yr, for the adenomatous colon polyp group 62 yr, and for the normal group was 56 yr. The adenomatous colon polyp and normal groups were predominantly female. Based on one way analysis of variance tests, there was no significant difference in selenoprotein-P or plasma selenium levels or extracellular glutathione peroxidase activity among the three groups (p = 0.28, 0.098, and 0.35 respectively). CONCLUSIONS: The present data suggest that patients with adenomatous colon polyps and those with colorectal cancer are not selenium deficient.     

The Mr 95,000 gelatin-binding protein in differentiated human macrophages and granulocytes

Cultured adherent human macrophages and a promonocytic cell line, U 937, were previously shown to produce a Mr 95,000 gelatin-binding protein. The protein has no immunologic cross-reactivity with the well- characterized gelatin-binding protein fibronectin and the Mr 70,000 gelatin-binding protein produced by a variety of mesenchymal or epithelial cell types (T. Vartio et al, J Biol Chem 257:8862, 1982). In the present study the Mr 95,000 protein was found in Triton X-100 extracts of granulocytes purified from human blood buffy coat. The protein, as isolated by gelatin-agarose, was immunologically cross- reactive with the corresponding macrophage protein in immunoblotting assay. When peripheral blood and bone marrow cells were examined for the presence of the Mr 95,000 protein by indirect immunofluorescence, positive staining was detected only in differentiated granulocytes but not to any significant extent in metamyelocytes, myelocytes, promyelocytes, or in normal or leukemic blasts. In granulocytes the protein had a granular cytoplasmic distribution. In freshly prepared monocyte cultures, the Mr 95,000 protein was detected in low amounts in the cytoplasm, while along with differentiation of the cells into macrophages, the immunofluorescence increased in a reticular and vesicular cytoplasmic pattern and in a juxtanuclear cap, probably representing the Golgi complex. In conclusion, the Mr 95,000 gelatin- binding protein was specifically detected in macrophages and granulocytes and may thus serve as a differentiation marker for these phagocytic cells.     

Effects of bacterial vaginosis and other genital infections on the natural history of human papillomavirus infection in HIV-1-infected and high-risk HIV-1-uninfected women

BACKGROUND: Whether the natural history of human papillomavirus (HPV) infection is affected by bacterial vaginosis (BV) or Trichomonas vaginalis (TV) infection has not been adequately investigated in prospective studies. METHODS: Human immunodeficiency virus 1 (HIV-1)-infected (n=1763) and high-risk HIV-1-uninfected (n=493) women were assessed semiannually for BV (by Nugent's criteria), TV infection (by wet mount), type-specific HPV (by polymerase chain reaction with MY09/MY11/HMB01 HPV primers), and squamous intraepithelial lesions (SIL) (by cytological examination). Sexual history was obtained from patient report at each visit. Risk factors for prevalent and incident HPV infection and SIL were evaluated by use of multivariate models. RESULTS: BV was associated with both prevalent and incident HPV infection but not with duration of HPV infection or incidence of SIL. TV infection was associated with incident HPV infection and with decreased duration and lower prevalence of HPV infection. TV infection had no association with development of SIL. Effects of BV and TV infection were similar in HIV-1-infected and high-risk HIV-1-uninfected women. HIV-1 infection and low CD4(+) lymphocyte count were strongly associated with HPV infection and development of SIL. CONCLUSIONS: BV and TV infection may increase the risk of acquisition (or reactivation) of HPV infection, as is consistent with hypotheses that the local cervicovaginal milieu plays a role in susceptibility to HPV infection. The finding that BV did not affect persistence of HPV infection and that TV infection may shorten the duration of HPV infection helps explain the lack of effect that BV and TV infection have on development of SIL.     

The moderating role of working memory capacity and alcohol-specific rule-setting on the relation between approach tendencies and alcohol use in young adolescents

Background: Dual process models of alcohol addiction propose that the transition from normative alcohol consumption to heavy drinking is the result of an imbalance in interplay between relatively impulsive or automatic and reflective or controlled processes. The current study examines whether impulsive and reflective processes are also detectable in a sample of adolescents with limited alcohol use. Methods: Specifically, we tested the interaction between alcohol approach tendencies and 2 types of reflective processes, working memory capacity (WMC) and alcohol‐specific rule‐setting, on changes in alcohol use of 238 young adolescents (mean age: 13.82 years). Gender differences in these associations were also explored. Results: Results showed that WMC did not moderate the relation between approach tendencies and subsequent alcohol use, whereas rule‐setting did, with stronger associations between approach tendencies and alcohol use for male adolescents reporting more permissive parents than male adolescents with parents enforcing stricter rules involving alcohol use. Associations between approach tendencies and subsequent alcohol use did not emerge for female adolescents. Conclusions: Results indicate that even in a sample of adolescents with limited drinking experience, automatic processes are positively associated with alcohol use for male adolescents that are not motivated by parents to control their drinking.     

The process of cognitive behaviour therapy for chronic fatigue syndrome: Which changes in perpetuating cognitions and behaviour are related to a reduction in fatigue?

Objective

Cognitive behaviour therapy (CBT) can significantly reduce fatigue in chronic fatigue syndrome (CFS), but little is known about the process of change taking place during CBT. Based on a recent treatment model (Wiborg et al. J Psych Res 2012), we examined how (changes in) cognitions and behaviour are related to the decrease in fatigue.

Methods

We included 183 patients meeting the US Centers for Disease Control criteria for CFS, aged 18 to 65 years, starting CBT. We measured fatigue and possible process variables before treatment; after 6, 12 and 18 weeks; and after treatment. Possible process variables were sense of control over fatigue, focusing on symptoms, self-reported physical functioning, perceived physical activity and objective (actigraphic) physical activity. We built multiple regression models, explaining levels of fatigue during therapy by (changes in) proposed process variables.

Results

We observed large individual variation in the patterns of change in fatigue and process variables during CBT for CFS. Increases in the sense of control over fatigue, perceived activity and self-reported physical functioning, and decreases in focusing on symptoms explained 20 to 46% of the variance in fatigue. An increase in objective activity was not a process variable.

Conclusion

A change in cognitive factors seems to be related to the decrease in fatigue during CBT for CFS. The pattern of change varies considerably between patients, but changes in process variables and fatigue occur mostly in the same period.