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991.
BACKGROUND: the effects of long-term administration of beta-blockers on left ventricular (LV) function during exercise in patients with ischemic heart disease (IHD) and idiopathic dilated cardiomyopathy (DCM) are controversial. PATIENTS AND METHODS: patients with stable congestive heart failure (CHF) (New York heart association [NYHA] class II and III) and ejection fraction (EF) < or =0.40 were randomized to metoprolol, 50 mg t.i.d. or placebo for 6 months. Patients were divided into two groups: ischemic heart disease (IHD) and idiopathic dilated cardiomyopathy (DCM). The mean EF was 0.29 in both groups and 92% were taking angiotensin-converting enzyme (ACE) inhibitors. In the IHD group, 84% had suffered a myocardial infarction (MI) and 64% had undergone revascularization at least 6 months before the study. LV volumes were measured by equilibrium radionuclide angiography. Mitral regurgitation was assessed by Doppler echocardiography. All values are changes for metoprolol subtracted by changes for placebo. RESULTS: metoprolol improved LV function markedly both at rest and during sub-maximal exercise in both groups. The mean increase in EF was 0.069 at rest (P<0.001) and 0.078 during submaximal exercise (P<0.001). LV end-diastolic volume decreased by 22 ml at rest (P=0.006) and by 15 ml during exercise (P=0.006). LV end-systolic volume decreased by 23 ml both at rest (P=0.001) and during exercise (P=0.004). Exercise time increased by 39 s (P=0.08). In the metoprolol group, mitral regurgitation decreased (P=0.0026) and only one patient developed atrial fibrillation vs. eight in the placebo group (P=0.01). CONCLUSION: metoprolol improves EF both at rest and during submaximal exercise and prevents LV dilatation in mild to moderate CHF due to IHD or DCM.  相似文献   
992.
The immunostimulatory activity of viridans streptococcal strains isolated from neutropenic patients with severe sepsis (n=9) or uncomplicated bacteraemia (n=10) was compared. Peripheral blood mononuclear cells from healthy individuals were stimulated with heat-killed bacteria or culture supernatants, and cytokine production assessed. All strains were potent inducers of IL1beta, IL8, and TNFalpha production. Heat-killed bacteria induced consistently higher IL1beta and TNFalpha production than did the cell-free bacterial supernatants (P<0.01). The strains did not induce any proliferative response, nor any significant TNFbeta or IFNgamma production. No difference in cytokine-inducing capacity could be detected between the cohorts of severe and nonsevere isolates. Comparison of strains causing severe and nonsevere episodes in the same patient (n=2) revealed a significantly higher induction of IL1beta by the severe episodes associated isolates as compared to the nonsevere (P<0.04). The study underscores the importance of the host-pathogen interplay in determining the level of inflammation, and hence the severity of disease.  相似文献   
993.
OBJECTIVE: To investigate the effects of a selective serotonin reuptake inhibitor (SSRI) on the neuroendocrine and autonomic nervous system perturbations found in abdominal obesity. DESIGN: Treatment for 6 months with citalopram and for 6 months with placebo using a double-blind, cross-over design, with a 2-month wash-out period between treatment periods. SUBJECTS: Sixteen healthy men, 45-60 years, moderately obese and with an abdominal fat distribution. MEASUREMENTS: Anthropometry, three different depression rating scales, serum lipids, testosterone, IGF-I, oral glucose tolerance test (OGTT), pituitary stimulation with corticotropin releasing hormone (CRH), arithmetic stress test, and excretion of cortisol and metoxycatecholamines in urine, collected during 24 h. RESULTS: Cortisol concentrations in the morning were low before treatment, indicating a perturbed function of the hypothalamic-pituitary-adrenal (HPA) axis. After treatment with citalopram morning cortisol concentrations rose to normal. Cortisol concentrations after stimulation with CRH or stress were elevated by citalopram treatment, but urinary cortisol excretion was unchanged. The glucose concentrations after OGTT (120 min) tended to be reduced, with unchanged insulin concentrations, whilst other metabolic values did not change during treatment. Heart rate after administration of CRH, and during laboratory stress test, decreased by treatment with citalopram. Diurnal urinary excretion of metoxycatecholamines tended to decrease. Neither body mass index nor waist/hip circumference ratio decreased. Depression scores were within normal limits before treatment and did not change. CONCLUSION: The results of this pilot study indicate improvements in the regulation of neuroendocrine-autonomic systems as well as metabolism in abdominal obesity during treatment with an SSRI.  相似文献   
994.
BACKGROUND: This study describes how surgery for Crohn colitis developed between 1970 and 1997, towards the end of which period limited resection and medical maintenance treatment was introduced. METHODS: A cohort of 211 patients with Crohn colitis (115 population-based), of which 84 had a primary colonic resection (42 population-based), was investigated regarding indication for surgery, the time from diagnosis to operation, type of primary colonic resection, risk for permanent stoma and medication over four 7-year periods. RESULTS: Comparison of the periods 1970-90 and 1991-97 revealed that active disease as an indication for surgery decreased from 64% to 25% (P<0.01) while stricture as an indication increased from 9% to 50% (P < 0.001). Median time from diagnosis to operation increased from 3.5 to 11.5 years (P < 0.01). Proctocolectomy or colectomy fell from 68.8% to 10% of the primary resections, whereas segmental resection increased from 31.2% to 90%. At the end of the first 7-year period, 26% had medical maintenance treatment, steroids or azathioprine taken by 7%. Corresponding figures for the last period were 70% and 49%. Patients diagnosed during the last two time-periods had less risk for surgery (P = 0.017), permanent stoma (P < 0.01) and total colectomy (P < 0.01). Findings were similar in the population-based cohort. CONCLUSIONS: Current management of Crohn colitis implies a longer period between diagnosis and surgery, a reduced risk for surgery and permanent stoma, and the replacement of total colectomy by segmental resection.  相似文献   
995.
We investigated whether the described immune evasion of Epstein-Barr virus (EBV)-infected malignant Hodgkin and Reed-Sternberg (HRS) cells in Hodgkin's disease (HD) is paralleled by a disturbed expression of the signal transduction molecule zeta associated with CD3 and CD16 in tumour-associated T lymphocytes (TAL). Flow cytometric analysis revealed a significantly lower zeta expression in CD3+/4+, CD3+/8+ and CD16+ patient peripheral blood lymphocytes (PBL; n = 10) compared with normal donor PBLs (n = 11). When patient PBLs were compared with the corresponding TAL, the latter showed a significantly higher (CD3+/4+) or equal (CD3+/8+) zeta expression. The EBV status of the tumours did not correlate with zeta expression in the TAL. Immunohistochemical staining revealed zeta-positive lymphocytes among the adjacent bystander cells of the HRS cells in all analysed tumours (n = 8), irrespective of tumour EBV status. In conclusion, these results do not support downregulation of zeta in TAL as a critical mechanism contributing specifically to the immune escape of EBV+ HRS cells.  相似文献   
996.
BACKGROUND: Several studies have indicated that cryptorchidism is associated with degenerative changes in both Sertoli cells and germ cells. The gonadal peptide hormone inhibin B reflects Sertoli cell function. Low inhibin B levels are found in a large portion of formerly cryptorchid men who show compromised seminiferous tubule function. It is not known if inhibin B can be used to demonstrate early damage of seminiferous tubules in prepubertal boys with cryptorchidism. METHODS: We investigated the relationship between serum levels of inhibin B, testosterone, FSH and LH in 62 prepubertal boys with uni- and bilateral cryptorchidism. Furthermore, we investigated the changes in serum levels of inhibin B and the corresponding changes in serum levels of FSH, LH and testosterone during a short course (3 weeks) of human chorionic gonadotropin (hCG) injections in 18 of these cryptorchid boys. RESULTS: In the 62 prepubertal boys with uni- or bilateral cryptorchidism there were no significant differences in baseline levels (median and range) of inhibin B (88 (20-195) pg/ml vs 78 (35-182) pg/ml; not significant), LH (0.08 (<0.05-0.99) IU/l vs 0.06 (<0.05-1.61) IU/l; not significant) and FSH (0.60 (0.08-3.73) IU/l vs 0.85 (0.25-2.55); not significant) compared with 156 healthy prepubertal boys, and there were no differences in hormonal levels between boys with uni- or bilateral cryptorchidism. There was no correlation between baseline levels of inhibin B and FSH. In boys younger than 9 years, we found no correlation between baseline levels of inhibin B and LH whereas, in boys older than 9 years, baseline levels of inhibin B were positively correlated to baseline LH (Spearman rank correlation coefficient ((R(s))=0.58, P=0.03). Treatment with hCG (1500 IU intramuscularly twice weekly for 3 weeks) resulted in descensus of testes in 9 out of 18 patients. In all boys but one, irrespective of age, hCG induced a marked increase in testosterone into the adult range (from undetectable to 21.8 (7.0-35.4) nmol/l; P<0.001) and completely suppressed FSH and LH levels. Serum levels of inhibin B increased significantly from 116 (50-195) pg/ml to 147 (94-248) pg/ml (P<0.05), but not uniformly. The increase in serum levels of inhibin B was inversely correlated to baseline inhibin B (Rs=-0.52, P=0.03) and baseline FSH (R(s)=-0.59, P<0.01). CONCLUSIONS: We therefore suggest that, in the prepubertal testes, inhibin B is secreted from the prepubertal Sertoli cells following hCG, whereas early pubertal testes with more differentiated Sertoli cells are not able to secrete inhibin B in response to hCG stimulation, perhaps due to lack of germ cell-derived betaB-subunits. We found (a) normal inhibin B levels in prepubertal boys with uni- or bilateral cryptorchidism, (b) that hCG stimulated testosterone markedly and suppressed FSH and LH levels and (c) that hCG treatment stimulated inhibin B levels in the youngest cryptorchid boys. In the oldest prepubertal boys no hCG-induced changes in inhibin B were shown.  相似文献   
997.
Human immunodeficiency virus (HIV)-specific cytotoxic T lymphocyte (CTL) responses are detectable shortly after the acute phase of HIV infection, but they cannot control viral replication and prevent development of chronic immune suppression. This article describes a defect in the coexpression of perforin in granzyme A-positive CD8(+) T cells in lymphoid tissue from patients with acute HIV infection and a reduction in the perforin-dependent nuclear translocation of granzyme A. Furthermore, intracellular levels of HIV DNA and RNA found in lymphoid tissue were higher (10-100 times) than those found in blood, and blood samples showed more-coordinated cellular perforin/granzyme A expression. This suggests that mechanisms inhibiting CTL-mediated cytotoxicity are operative in lymphoid tissue early in the course of HIV infection.  相似文献   
998.
The aim of the present study was to test whether cimetidine (Cim) influences PIF (prolactin inhibitory factor), and thereby indirectly affects the release of prolactin (PRL) from the pituitary lactotrophs. For that purpose 10 mg metoclopramide (Met), known for its dopamine-receptor blocking properties, were first given orally to 6 subjects. This raised the PRL level from 13 ± 2 to 97 ± 12 ng/ml in 60 min (p < 0.001). PRL tended to plateau at this level until 120 min. An additional 7 subjects were then injected iv with 400 mg Cim, 90 min after oral administration of placebo. Placebo did not change the basal PRL level, but the subsequent Cim injection raised the PRL level from 14 ± 4 to 66 ± 9 ng/ml (p < 0.01). When, in the same subjects, an oral dose of Met was given (10 mg) PRL increased from 19 ± 4 to 112 ± 10 ng/ml (p < 0.001). A subsequent Cim injection, given on top of the PRL plateau, 90 min after the Met ingestion, however, failed to induce any further increase in PRL. To exclude that this failure was not merely a reflection of a Met-induced depletion of the PRL stores, 25 μg thyrotropin-releasing hormone (TRH) were given iv to an additional 6 subjects, 90 min after ingestion of either placebo or Met. Also in these subjects placebo left basal PRL unaffected. The subsequent TRH injection, however, raised PRL from 10 ± 2 to 55 ± 6 ng/ml (p < 0.001). Met increased PRL from 17 ± 4 to 133 ± 19 ng/ml (p < 0.01) in these subjects, and TRH, subsequently injected, induced a further PRL increase to 174 ± 18 ng/ml (p < 0.01). The observation that Cim fails to elicit an increase in PRL after priming with Met thus indicates that Cim, under normal conditions, stimulates the PRL release via a reduced dopaminergic inhibition of the lactotrophs.  相似文献   
999.
Cloned lines of helper thymus-derived (T) cells produce help for bone marrow-derived (B) cell growth and Ig secretion in the presence of histocompatible adherent cells and of specific antigen. This help stimulates histocompatible as well as histoincompatible B-cell blasts polyclonally. Thus, neither antigen nor histocompatibility, but antigen-unspecific factor(s) for growth and Ig secretion are required to stimulate a B-cell blast through the next round of division. On the other hand, only histocompatible, resting, small B cells, and only those binding their specific antigen, can be stimulated by antigen-activated T-cell help to initiate growth and Ig secretion. The preference of the resting B cells for such collaboration with T-cell help is mapped to the K end of the H-2 histocompatibility locus, and probably constitutes the antigen expressed on B cells by the immune response (I) region. It appears that a resting B cell is excited by the binding of specific antigen to surface Ig and by the interaction of its surface Ia antigen with helper T cells. After this dual recognition the excited B cell can be stimulated by the antigen-unspecific factor(s) generated by the interaction of helper T-cells, adherent cells, and antigen to initiate replication.  相似文献   
1000.
Objectives: Fecal immunochemical test (FIT) is used in colorectal cancer (CRC) screening, but evaluations of multiple sample strategies in colonoscopy screening cohorts are rare. The aim of this study was to assess accuracy of FIT for advanced neoplasia (AN) with two fecal samples in a colonoscopy screening cohort.

Materials and methods: The study comprised 1155 participants of the colonoscopy arm in SCREESCO (Screening of Swedish Colons, NCT02078804), a randomized controlled study on CRC screening of 60-year-olds from the Swedish average-risk population. Participants provided two FIT samples prior to colonoscopy. First sample, mean of two, and any of the two samples above cut off level were assessed. Colonoscopy findings (CRC, advanced adenoma (AA), AN (CRC?+?AA) and adenoma characteristics) were evaluated in uni- and multivariable analysis in relation to FIT positivity (at ≥10?µg hemoglobin (Hb)/g).

Results: Of 1155 invited, 806 (416 women, 390 men) participated. CRC, AA and non-AA were found in one (0.1%), 80 (9.9%) and 145 (18%), respectively. Sensitivity and specificity for AN were 20%/93%, 25%/92% and 26%/89% for first, mean of two and any of the two samples respectively at cut off level 10?µg/g, corresponding to 60 (74%)–65 (80%) participants with missed AN. The difference in sensitivity between screening strategies was non-significant. The specificity for first sample was significantly higher than for any of the two samples at cut off 10?µg/g (p?=?.02) and 20?µg/g (p?=?.04). FIT positivity in participants with adenoma was associated with pedunculated shape (p?=?.007) and high-risk dysplasia (p?=?.009).

Conclusions: In an average-risk colonoscopy screening cohort of 60-year-olds, sensitivity for AN was modest and did not increase when using two samples instead of one. FIT predominantly detected adenomas with pedunculated shape and high-risk dysplasia, and participants with flat or broad based adenomas may thus be missed in screening.  相似文献   

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