Structure of phage phi 29 connector protein assembled in vivo

The protein p10 that forms the connector of phage phi 29, has been produced in Escherichia coli harboring a plasmid that carried the gene coding for this protein. The connector protein is assembled in a 13.4-S oligomer that has an apparent molecular weight of 460,000, suggesting that it is a dodecamer. The purified oligomers have been studied by electron microscopy of the isolated particles as well as by image-processing techniques (Fourier and rotational filtering) of artificially induced two-dimensional aggregates. The results show that the purified p10 is assembled in a circular structure with a hole in its center and 12 morphological units in the periphery. Both the morphology and the dimensions of this p10 oligomer are very similar to those of the upper neck collar extracted from phi 29 viral particles. The results strongly suggest the close relationship between the p10 oligomers assembled in E. coli and the ones produced in phi 29 infected Bacillis subtilis.     

Treatment of thoracoabdominal gunshot wounds in civilian practice. Experience with forty-four cases

Forty-four acute cases of thoracoabdominal injuries in civilian practice are presented. Injury to multiple abdominal organs occurred in 50 per cent. The mortality in those with multiple organ injuries was 33 per cent whereas among those with injury to a solitary organ it was 4.5 per cent. The liver was injured in 61 per cent of cases. Although intercostal tube drainage (50 per cent) usually suffices in the management of the chest injury, thoracotomy was indicated in a number of cases. We advocate preservation of the thoracoabdominal barrier, by making a separate thoracic and abdominal wound, to prevent thoracic contamination, diaphragmatic hernia, and to achieve a thorough abdominal exploration. The total complication rate is 25 per cent. There were nine deaths (20 per cent) in the entire series, eight of which were directly related to the thoracoabdominal injury, yielding a corrected mortality of 18 per cent. One patient died from a separate gunshot wound to the brain.     

The anti-inflammatory prostaglandin 15d-PGJ<Subscript>2</Subscript> decreases oxidative/nitrosative mediators in brain after acute stress in rats

Rationale Immobilisation stress is followed by accumulation of oxidative/nitrosative mediators in brain after the release of tumour necrosis factor-alpha (TNF) and other cytokines, nuclear factor kappa B (NFB) activation, nitric oxide synthase-2 (NOS-2) and cyclooxygenase-2 (COX-2) expression in the brain.Objectives This study was conducted to assess if some of the anti-inflammatory products of COX can modify the accumulation of oxidative/nitrosative species seen in brain after stress and to study the mechanisms by which this effect is achieved.Methods Young-adult male Wistar rats were subjected to a single session of immobilisation during 6 h.Results In stressed animals, brain levels of the anti-inflammatory 15d-PGJ₂ increases concomitantly with COX-2 expression. Inhibition of COX-2 with NS-398 prevents stress-induced 15d-PGJ₂ increase. Injection of supraphysiological doses of 15d-PGJ₂ (80–120 g/kg) decreases stress-induced increase in NOS-2 activity as well as the stress-induced increase in NO metabolites. On the other hand, 15d-PGJ₂ decreases stress-induced malondialdehyde (an indicator of lipid peroxidation) accumulation in cortex and prevents oxidation of the main anti-oxidant glutathione. The mechanisms involved in the anti-oxidative properties of 15d-PGJ₂ in stress involve NFB blockade (by preventing stress-induced IB decrease) as well as inhibition of TNF release in stressed animals. At the doses tested, 15d-PGJ₂ decreases COX-2 expression and PGE₂ release during stress, suggesting an alternative mechanism for this endogenous compound.Conclusions These findings demonstrate a role for this anti-inflammatory pathway in the brain response to stress and open the possibility for preventing accumulation of oxidative/nitrosative species and subsequent brain damage.     

Cortical distinction between the neural encoding of objects that appear to glow and those that do not

Objects that appear to glow appear very different from those that do not. However, the neural representation of glow has not been investigated. We present data from an fMRI study which suggest that an extra-striate visual area is involved in the encoding of glowing stimuli, and that this activation does not arise from luminance or contrast factors. Possible functional reasons for the existence of such an area are discussed.     

Transplantation of monocytes: a novel strategy for in vivo augmentation of collateral vessel growth

Therapeutic augmentation of collateral vessel growth (arteriogenesis) is of particular clinical interest. Because monocytes localize to areas of collateral growth and create a highly arteriogenic environment through secretion of multiple growth factors, we tested the hypothesis that monocyte "homing" can therapeutically be exploited. We have used a rabbit model of arteriogenesis to investigate the therapeutic potential of transplanted rabbit monocytes that were either ex vivo stimulated or adenovirally transduced to express a transgene encoding an arteriogenic growth factor. The monocytes were intravenously injected 24 hr or 7 days after ligation of the animal's right femoral artery. Seven days after transplantation collateral flow was determined with a doppler flow probe and collateral vessels were quantified angiographically. Whereas transplantation of allogeneic cells (same species) resulted in a strong promotion of arteriogenesis, most likely through induction of local inflammation and recruitment of recipient monocytes, transplantation of autologous cells (same animal) was not able to significantly augment collateralization. However, when autologous monocytes were used as vehicles to deliver granulocyte macrophage-colony stimulating factor as therapeutic transgene, collateralization was strongly augmented. Their localization to the site of collateral development posttransplantation was demonstrated by ex vivo transduction with beta-galactosidase. Because isolation of monocytes is clinically widely available their ex vivo engineering and transplantation represents an intriguing new strategy for therapeutic arteriogenesis.     

Ethical Issues Pertaining to Research in the Aftermath of Disaster

In January 2003, The New York Academy of Medicine and the National Institute of Mental Health sponsored a meeting entitled "Ethical Issues Pertaining to Research in the Aftermath of Disaster." The purpose of the meeting was to bring together various experts to examine evidence concerning the impact of research on trauma-exposed participants, review the applicable ethical principles and policies concerning protection of human subjects, and offer guidance to investigators, IRBs, public health and local officials, and others interested in assuring that research in the aftermath of a disaster is conducted in a safe and ethical manner. This article summarizes the group's key findings and outlines potential considerations for those working in this field.     

Tumor cell-specific BRCA1 and RASSF1A hypermethylation in serum, plasma, and peritoneal fluid from ovarian cancer patients

Because existing surgical and management methods can consistently cure only early-stage ovarian cancer, novel strategies for early detection are required. Silencing of tumor suppressor genes such as p16INK4a, VHL, and hMLH1 have established promoter hypermethylation as a common mechanism for tumor suppressor inactivation in human cancer and as a promising target for molecular detection in bodily fluids. Using sensitive methylation-specific PCR, we screened matched tumor, preoperative serum or plasma, and peritoneal fluid (washes or ascites) DNA obtained from 50 patients with ovarian or primary peritoneal tumors for hypermethylation status of the normally unmethylated BRCA1 and RAS association domain family protein 1A tumor suppressor genes. Hypermethylation of one or both genes was found in 34 tumor DNA (68%). Additional examination of one or more of the adenomatous polyposis coli, p14ARF, p16INK4a, or death associated protein-kinase tumor suppressor genes revealed hypermethylation in each of the remaining 16 tumor DNA, which extended diagnostic coverage to 100%. Hypermethylation was observed in all histologic cell types, grades, and stages of ovarian tumor examined. An identical pattern of gene hypermethylation was found in the matched serum DNA from 41 of 50 patients (82% sensitivity), including 13 of 17 cases of stage I disease. Hypermethylation was detected in 28 of 30 peritoneal fluid DNA from stage IC-IV patients, including 3 cases with negative or atypical cytology. In contrast, no hypermethylation was observed in nonneoplastic tissue, peritoneal fluid, or serum from 40 control women (100% specificity). We conclude that promoter hypermethylation is a common and relatively early event in ovarian tumorigenesis that can be detected in the serum DNA from patients with ovary-confined (stage IA or B) tumors and in cytologically negative peritoneal fluid. Analysis of tumor-specific hypermethylation in serum DNA may enhance early detection of ovarian cancer.     

TNF-alpha accounts for short-term persistence of oxidative status in rat brain after two weeks of repeated stress

Inducible nitric oxide synthase (NOS-2) accounts for the accumulation of oxidative and nitrosative mediators in brain after stress. To determine whether and when repeated exposure to immobilization stress leads to persistent oxidative status in rat brain, male Wistar rats were immobilized for 6 h/day for 7 or 14 days (S7, S14). Cerebral cortices were obtained immediately after the last session of stress or 1 day later. Stress increased NOS-2 activity after S7 or S14. This enzymatic activity returned to basal values 1 day after S7, but not 1 day after S14. Stress increased malondialdehyde (MDA) accumulation in cortex after S7 and S14. MDA levels returned to basal values 1 day after S7 but not 1 day after S14. In order to elucidate the possible mechanisms involved in this short-term persistence of oxidative status, brain levels of the cytokine tumour necrosis factor alpha (TNF-alpha) were determined. TNF-alpha levels did not increase after S7 or 1 day after S7, but increased after S14 and 1 day after S14. This was paralleled by an increase in TNF-alpha converting enzyme (TACE) activity in brain. When the increase in TNF-alpha at S14 was blocked by BB1101, an inhibitor of TACE, or its effects were blocked with anti-TNF-alpha, the accumulation of MDA and NOS-2 activity 1 day after S14 did not take place. These findings indicate that TACE and TNF-alpha account for stress-induced short-term persistence of NOS-2 activity and MDA accumulation after 14 days of repeated exposure and support a possible neuroprotective role for specific blockers of TNF-alpha in this situation.