Trans activation of the Escherichia coli ato structural genes by a regulatory protein from Bacillus megaterium: potential use in polyhydroxyalkanoate production

A Bacillus megaterium genomic fragment, which encoded an activator homologous to sigma 54 regulators and which was capable of activating Escherichia coli ato genes in trans, was detected in a gene library of B. megaterium screened for beta-ketothiolase activity. The fragment presented only one complete open reading frame (ORF1), which encoded a protein of 398 amino acids. The recombinant plasmid complemented mutations in the Escherichia coli atoC regulatory gene. The constitutive expression of the E. coli ato operon mediated by ORF1 could be useful for the synthesis of polyhydroxyalkanoates with different flexibility properties by recombinant E. coli strains.     

Cadmium inhibits proteoglycan and procollagen production by cultured human lung fibroblasts

OBJECTIVE: Previously, we showed that 15-20% of patients with rheumatoid arthritis (RA) have oligoclonal expansions of peripheral blood CD8+ T cells expressing T cell receptors encoded by the V(alpha)12 (AV12S1) gene. To better understand the significance of these expansions, the present study was undertaken to determine their specificity. METHODS: We cloned and characterized V(alpha)12+,CD8+ T cells from the peripheral blood of 1 RA patient with a clonal expansion of these T cells. RESULTS: The T cell clones were autoreactive since they recognized autologous, but not allogeneic, antigen-presenting cells. Upon activation, these T cells secreted interleukin-4 and interleukin-10. The autoreactive T cell clones were class I major histocompatibility complex (MHC) restricted, by either HLA-B60 or HLA-Cw3. CONCLUSION: A large population of class I MHC-restricted CD8+ T cells in a patient with RA is clonally expanded and autoreactive. These cells define a novel immune aberration in RA and provide a tool for defining the autoantigens that activate expanded T cell populations in vivo.     

Cardioprotective effects of the novel adenosine A1/A2 receptor agonist AMP 579 in a porcine model of myocardial infarction

This study examined the cardioprotective effects and pharmacology of the novel adenosine A1/A2 receptor agonist ([1S-[1a,2b,3b, 4a(S*)]]-4-[7-[[2-(3-chloro-2-thienyl)-1-methylpropyl]amino]-3H-imida zo[4,5-b] pyridyl-3-yl] cyclopentane carboxamide) (AMP 579), in a model of myocardial infarction. Experiments were performed in pentobarbital-anesthetized pigs in which myocardial infarction was induced by a 40-min occlusion of the left anterior descending coronary artery, followed by 3 hr of reperfusion. This procedure resulted in approximately 20% of the left ventricle being made ischemic in all test groups. In untreated animals, an infarct size equal to 56 +/- 5% of the ischemic area was observed. Preconditioning, with two cycles of 5 min of ischemia followed by 10-min reperfusion, resulted in a 70% reduction in infarct size (17 +/- 5%) relative to risk area. Administration of AMP 579 30 min before ischemia (3 microg/kg i.v. followed by 0.3 microg/kg/min i.v. through 1 hr of reperfusion) did not change blood pressure, HR or coronary blood flow but resulted in marked cardioprotection: a 98% reduction in infarct size (1 +/- 1%) relative to risk area. Moreover, whereas approximately 90% of control pigs suffered ventricular fibrillation during ischemia, no fibrillation was observed in animals treated with AMP 579. Further experiments determined the effects of AMP 579 when administered 30 min after the onset of myocardial ischemia, 10 min before reperfusion. Two doses were studied: a low hemodynamically silent dose (3 microg/kg + 0.3 microg/kg/min through 1 hr of reperfusion) and a 10-fold higher dose that did cause reductions in blood pressure and HR. Both doses of AMP 579 produced a comparable cardioprotective effect, reducing infarct size to approximately 50% of that observed in control animals. The cardioprotective effect of AMP 579 was a consequence of adenosine receptor stimulation, because it was completely inhibited by pretreatment with the specific adenosine receptor antagonist CGS 15943 (1 mg/kg i.v.). However, the selective A1 receptor agonist GR 79236 (3 microg/kg + 0.3 microg/kg/min i.v.) did not reduce infarct size, which suggests that under these experimental conditions, stimulation of adenosine A2 receptors is important for the cardioprotective effect of AMP 579. The adenosine-regulating agent acadesine (5 mg/kg + 0.5 mg/kg/min i.v.) also failed to reduce infarct size. In conclusion, the novel adenosine A1/A2 receptor agonist AMP 579 produces marked cardioprotection whether administered before myocardial ischemia or reperfusion. Cardioprotection is not dependent on changes in afterload or myocardial oxygen demand and is a consequence of adenosine receptor stimulation. The pharmacological profile of AMP 579 in this model is consistent with its potential utility in the treatment of acute myocardial infarction.     

Carcinoma of the tonsillar fossa: prognostic factors and long-term therapy outcome

PURPOSE: To identify prognostic parameters and evaluate the therapeutic outcomes for patients with carcinoma of the tonsillar fossa treated with three treatment modalities. METHODS AND MATERIALS: The results of therapy are reported in 384 patients with histologically proven epidermoid carcinoma of the tonsillar fossa; 154 were treated with irradiation alone (55-70 Gy), 144 with preoperative radiation therapy (20-40 Gy), and 86 with postoperative irradiation (50-60 Gy). The operation in all but four patients in the last two groups consisted of an en bloc radical tonsillectomy with ipsilateral lymph node dissection. RESULTS: Treatment modality and total irradiation doses had no impact on survival. Actuarial 10-year disease-free survival rates were 65% for patients with T1 tumors, 60% for T2, 60% for T3, and 30% for T4 disease. Patients with no cervical lymphadenopathy or with a small metastatic lymph node (N1) had better disease-free survival (60% and 70%, respectively) at 5 years than those with large or fixed lymph nodes (30%). Primary tumor recurrence (local, marginal) rates in the T1, T2, and T3 groups were 20-25% in patients treated with irradiation and surgery and 31% for those treated with irradiation alone (difference not statistically significant). In patients with T4 disease treated with surgery and postoperative irradiation, the local failure rate was 32% compared with 86% with low-dose preoperative irradiation and 47% with irradiation alone (p = 0.03). The overall recurrence rates in the neck were 10% for N0 patients, 25% for N1 and N2, and 35-40% for patients with N3 cervical lymph nodes, without significant differences among the various treatment groups. The incidence of contralateral neck recurrences was 8% with the various treatment modalities. On multivariate analysis the only significant factors for local tumor control and disease-free survival were T and N stage (p = 0.04-0.001). Fatal complications were noted in 7 of 144 (5%) patients treated with preoperative irradiation and surgery, 2 of 86 (2%) of those receiving postoperative irradiation, and 2 of 154 (1.3%) patients treated with radiation therapy alone. Other moderate or severe nonfatal sequelae were noted in 30% of the patients treated with preoperative irradiation and surgery, in 53% treated with postoperative irradiation, and in 19% receiving radiation therapy alone. CONCLUSION: Primary tumor and neck node stage are the only significant prognostic factors influencing locoregional tumor control and disease-free survival. Treatment modality had no significant impact on outcome. Radiation therapy remains the treatment of choice for patients with stage T1-T2 carcinoma of the tonsillar fossa. In patients with T3-T4 tumors and good general condition, combination surgery and postoperative irradiation offers better tumor control than single-modality and preoperative irradiation procedures, but with greater morbidity.     

Prenatal diagnosis of trisomy 13 on fetal cells obtained from maternal blood after minor enrichment

In a pilot study to establish fetal nucleated red blood cell (NRBC) detection in maternal blood, trisomy 13 was diagnosed by FISH analysis at 11 weeks' gestation. The NRBCs were detected after a single-step ficoll density gradient enrichment. In blood samples taken both before and after CVS, 52 and 80 NRBCs, respectively, were found to be positive for fetal haemoglobin. In 47 per cent of these cells, FISH analysis for X and Y chromosomes confirmed the fetal sex. Moreover, 48 per cent of these NRBCs showed three fluorescent signals for a chromosome 13 probe, which confirmed the diagnosis of trisomy 13, previously detected at CVS karyotyping. This is the first report of non-invasive prenatal diagnosis of trisomy 13, i.e., pre-CVS, in the first trimester. The high number of fetal NRBCs detected indicates a connection with aneuploidy, probably due to early impairment of the feto-maternal barrier.     

Randomized clinical trial on the combination of preoperative irradiation and surgery in the treatment of adenocarcinoma of gastric cardia (AGC)--report on 370 patients

PURPOSE: An attempt was made to define the role of radiotherapy before operation for AGC. METHODS AND MATERIALS: From January 1978 to May 1989, a prospective randomized trial on preoperative radiotherapy (R+S) vs. surgery alone (S) for AGC was carried out in 370 patients. Patients were randomized into a combined group (R+S, 171 patients) or a surgery alone group (S, 199 patients) by the envelope method. 8-MV photon or telecobalt was used for the preoperative radiation therapy, using anterior-posterior opposing parallel fields to deliver 40 Gy to the cardia, lower segment of the esophagus, fundus, lesser curvature, and hepatogastric ligament. Surgery was performed after 2 to 4 weeks rest. RESULTS: The 5- and 10-year survival rates of the R+S Group and the S Alone Group were 30.10% and 19.75%, 20.26% and 13.30%, respectively. The survival curves of these two groups diverged right from the beginning after the operation over the ninth year. Statistics by Kaplan-Meier log rank test proves that the difference is significant (chi2 = 6.74, p = 0.0094). The immediate results were: resection rate 89.5% and 79.4% (p < 0.01); pathologic stage after resection T2 12.9% and 4.5% (p < 0.01), T4 40.3% and 51.3% (p < 0.05), lymph node metastasis rates 64.3% and 84.9% (p < 0.001); operative mortality rates 0.6% and 2.5%; intrathoracic leak rates 1.8% and 4.0%, respectively. The causes of failure were: local uncontrol and recurrence 38.6% vs. 51.7% (p < 0.025), regional lymph node metastasis 38.6% vs. 54.6% (p < 0.005), distant metastasis 24.3% vs. 24.7%. CONCLUSION: Preoperative radiation therapy is able to improve the results of surgery for adenocarcinoma of the gastric cardia.     

Preferential benefit of implementation of a statewide trauma system in one of two adjacent states

BACKGROUND: Implementation of Oregon's trauma system was associated with a reduction in the risk of death for hospitalized injured patients. An alternative explanation for improved outcome, however, is favorable concurrent temporal trends, e.g., new technologies and treatments. PATIENTS AND METHODS: To control for temporal trends, seriously injured hospitalized patients in Oregon and Washington were compared before either state had a trauma system (1985-1988) and when only the Oregon trauma system had been implemented (1990-1993). The study group consisted of hospitalized injured patients aged 16 to 79 years with one or more index injuries in six body regions, i.e., head, chest, spleen/liver, femur or pelvis fracture, and burns. Hospital discharge claims data were analyzed, converting International Classification of Diseases, Ninth Revision, Clinical Modification, discharge diagnosis codes to Abbreviated Injury Scale scores and Injury Severity Scores using a conversion algorithm. Multivariate logistic regression models were used to estimate the differential risk-adjusted odds of death in Oregon compared with Washington after adjustment for demographics, injury type, and injury severity. RESULTS: Findings indicated no difference in the risk-adjusted odds of death between Oregon and Washington while both states functioned under an ad hoc trauma system (1985-1988). A significant reduction in the risk of death, however, was noted in Oregon for patients with an index injury and an Injury Severity Score > 15 compared with Washington (adjusted odds ratio (OR) = 0.80, 95% confidence interval (CI) = 0.70-0.91) after trauma system implementation in Oregon (1990-1993). Specifically, reductions in the risk of death were demonstrated for patients with head injuries (adjusted OR = 0.70, 95% CI = 0.59-0.82) or liver/spleen injuries (adjusted OR = 0.73, 95% CI = 0.54-0.99). CONCLUSION: Assuming that the two states demonstrated similar concurrent temporal trends, the findings support the conclusion that improved outcomes among injured patients in Oregon may be attributed to the institution of a statewide trauma system.     

Oral health of children undergoing allogeneic bone marrow transplantation

BACKGROUND: Mixed bone marrow chimerism reliably produces donor-specific transplantation tolerance for a variety of solid organ and cellular grafts. We used a rat heterotopic tracheal transplant model for chronic rejection to investigate whether mixed chimerism could successfully prevent obstructive airway disease. METHODS: Mixed allogeneic chimeras were prepared by reconstituting lethally irradiated Wistar-Furth (WF) recipients with a mixture of 5 x 10(6) T-cell-depleted syngeneic (WF) and 100 x 10(6) T-cell-depleted allogeneic (ACI) bone marrow cells (ACI + WF --> WF). Mixed chimerism was present in all animals 28 days after bone marrow transplantation. Donor-specific, syngeneic, or major histocompatibility complex (MHC)-disparate allogeneic tracheas were implanted in recipient's omentum and removed for histologic analysis 30 to 150 days after transplantation. RESULTS: At 30 days after implantation, median luminal obstruction grades (0=none, 4=complete) of syngeneic and allogeneic tracheas were 0 and 4, respectively. Donor-specific (ACI) tracheas implanted in chimeric (ACI + WF --> WF) recipients were remarkably free of obstruction (median luminal obstruction grade=0 at 150 days) and had excellent preservation of respiratory epithelium. Third-party F344 tracheas implanted in chimeric recipients developed progressive luminal obstruction (grade 2 at 30 days, grade 3 at 90 days). CONCLUSIONS: Mixed allogeneic chimerism induces donor-specific tolerance and prevents development of the characteristic fibroproliferative obstructive lesion of bronchiolitis obliterans in a rat heterotopic tracheal transplant model. Excellent preservation of tracheal structure and morphology was achieved across major and minor histocompatibility barriers.     

Lipopolysaccharide-binding protein is present in effluents of patients with Gram-negative and Gram-positive CAPD peritonitis

BACKGROUND: Bacterial peritonitis is a frequent complication during treatment of end-stage renal failure by continuous ambulatory peritoneal dialysis. Local host defence mechanisms including the secretion of proinflammatory cytokines by peritoneal macrophages are of particular importance in the pathogenesis of infectious complications. LPS-binding protein (LBP) and soluble CD14 (sCD14) are serum factors known to regulate the endotoxin-induced cellular immune response. However, it is still unknown whether LBP and sCD14 are also present in the peritoneal effluent of CAPD patients. METHODS: Using specific immunoassays, we examined the concentration of LBP, sCD14 and the proinflammatory cytokines TNF-alpha, IL-1beta and IL-6 in the dialysis effluents of 31 patients with CAPD-associated peritonitis. Twenty patients without peritonitis served as controls. Intraperitoneal LPS concentrations were determined using the limulus amebocyte lysate assay. RESULTS: Bacterial lipopolysaccharide could be detected in 42% of the infected dialysis effluents. In comparison to controls (0.2 +/- 0.05 microg/ml), LBP was significantly elevated in both gram-negative/LPS-positive (1.03 +/- 0.3 microg/ml) and gram-positive infections (0.5 +/- 0.14 microg/ml) (P<0.05). No significant differences were detected concerning the intraperitoneal sCD14 levels in the three patient groups. Levels of TNF-alpha, IL-1beta and IL-6 were significantly increased in the effluents of patients with bacterial peritonitis compared to noninfected controls. Moreover the respective cytokine concentrations were significantly higher in the gram-negative/LPS-positive compared to the gram-positive bacterial infections (P<0.01). CONCLUSION: Our data demonstrate that LBP is significantly elevated in the dialysis effluents of patients with CAPD-associated peritonitis caused by both gram-negative and gram-positive bacteria and might be used as a marker of intraperitoneal infection. Moreover, our findings support the concept that LBP enhances the effects of LPS on cytokine production by peritoneal macrophages. The function of LBP in gram-positive infection remains to be further elucidated.