Resolution of inflammation

Acute inflammatory reactions, in contrast to chronic inflammatory reactions, are usually self-limiting and resolve. We have investigated the resolving phase of a number of immune and non-immune inflammatory reactions induced in the pleural cavity of rats. COX-2 is expressed during resolution of these models. Using carrageenan pleurisy, we showed that this enzyme has a proinflammatory role as the reaction develops but an antiinflammatory role as the lesion resolves. This antiinflammatory role is associated with production of cyclopentenone prostaglandins and the absence of PGE2. Dual COX-1/COX-2 inhibitors or COX-2 inhibitors when given at the peak of the inflammatory response delay resolution, an effect reversed by replacing CyPGs into the pleural space. PGF2alpha like the CyPGs appears to have a role in resolving this reaction. Stress proteins are also induced in a variety of acute inflammatory models during resolution. Heme oxygenase-1 (HO-1) is one such protein so too are members of the hsp70 family. An inducer of HO-1 promotes resolution whereas an inhibitor is proinflammatory. In most cases it appears to be the macrophage that is the source of proteins necessary for resolution to occur. Understanding how proinflammatory pathways switch to the antiinflammatory pathways necessary for resolution to take place may eventually allow the exploitation of endogenous antiinflammatory pathways in the treatment of chronic inflammation.

Kinetic phases in the electron transfer from P+QA-QB to P+QAQB- and the associated processes in Rhodobacter sphaeroides R-26 reaction centers

Electron transfer from P+QA-QB to form P+QAQB- was measured in Rhodobacter sphaeroides R-26 reaction centers (RCs) where the native primary quinone, ubiquinone-10 (UQA), was replaced by 2-methyl-3-phytyl-1,4-naphthoquinone (MQA). The native secondary quinone, UQ-10, was retained as UQB. The difference spectrum of the semiquinone MQA- minus UQB- absorption is very similar to that of MQ- minus UQ- in solution (398-480 nm). Thus, the absorption change provides a direct monitor of the electron transfer from MQA- to UQB. In contrast, when both QA and QB are UQ-10 the spectral difference between UQA- and UQB- arises from electrochromic responses of RC chromophores. Three kinetic processes are seen in the near UV (390-480 nm) and near-IR (740-820 nm). Analysis of the time-correlated spectra support the conclusion that the changes at tau1 approximately 3 micros are mostly due to electron transfer, electron transfer and charge compensation are mixed in tau2 approximately 80 micros, while little or no electron transfer occurs at 200-600 micros (tau3) in MQAUQB RCs. The 80-micros rate has been previously observed, while the fast component has not. The fast phase represents 60% of the electron-transfer reaction (398 nm). The activation energy for electron transfer is DeltaG approximately 3.5 kcal/mol for both tau1 and tau2 between 0 and 30 degrees C. In isolated RCs with UQA, if there is any fast component, it appears to be faster and less important than in the MQA reconstituted RCs.

Genomic comparisons of Salmonella enterica serovar Dublin, Agona, and Typhimurium strains recently isolated from milk filters and bovine samples from Ireland, using a Salmonella microarray

Salmonella-induced enterocolitis is the leading food-borne illness with a lethal outcome and causes millions of cases of gastroenteritis each year. We examined genomic variation among 12 environmental, veterinary, and clinical Salmonella enterica serovar Dublin, Agona, and Typhimurium strains isolated in Ireland between 2000 and 2003, as well as two clinical isolates from Canada and four archival isolates, which belonged to serovars Dublin and Agona. Using DNA-DNA hybridization to a microarray consisting of most of the predicted protein-encoding sequences of the S. enterica serovar Typhimurium LT2 genome, we identified a number of genomic regions that were absent in one or more serovars. The 34 genomic regions encoded proteins involved in sugar metabolism, transport, fimbrial and phage biogenesis, and transcriptional regulation, as well as inner and outer membrane-associated proteins. Two of the four prophages identified in strain LT2, prophages Gifsy-1 and Gifsy-2, were present in all six serovar Typhimurium strains examined. Prophage Fels-1 was absent from all 18 isolates examined, and Fels-2 was completely absent from the serovar Typhimurium isolates and the Salmonella Reference Collection B serovar Dublin strain Du2. All five Salmonella pathogenicity islands were present in all isolates. Plasmid pSLT was absent from all serovar Agona isolates, and only homologues of the spv genes were present in eight of the nine serovar Dublin strains. Only limited intraserovar diversity was found among the nine serovar Dublin, three serovar Agona, and six serovar Typhimurium isolates examined even though these isolates had extensive geographic, temporal, and source differences.

X-ray diffraction studies of cross-bridges weakly bound to actin in relaxed skinned fibers of rabbit psoas muscle

X-ray diffraction patterns were obtained from skinned rabbit psoas muscle under relaxing and rigor conditions over a wide range of ionic strengths (50-170 mM) and temperatures (1 degree C-30 degrees C). For the first time, an intensification of the first actin-based layer line is observed in the relaxed muscle. The intensification, which increases with decreasing ionic strength at various temperatures, including 30 degrees C, parallels the formation of weakly attached cross-bridges in the relaxed muscle. However, the overall intensities of the actin-based layer lines are low. Furthermore, the level of diffuse scattering, presumably a measure of disorder among the cross-bridges, is little affected by changing ionic strength at a given temperature. The results suggest that the intensification of the first actin layer line is most likely due to the cross-bridges weakly bound to actin, and that the orientations of the weakly attached cross-bridges are hardly distinguishable from the detached cross-bridges. This suggests that the orientations of the weakly attached cross-bridges are not precisely defined with respect to the actin helix, i.e., nonstereospecific. Intensities of the myosin-based layer lines are only marginally affected by changing ionic strength, but markedly by temperature. The results could be explained if in a relaxed muscle the cross-bridges are distributed between a helically ordered and a disordered population with respect to myosin filament structure. Within the disordered population, some are weakly attached to actin and others are detached. The fraction of cross-bridges in the helically ordered assembly is primarily a function of temperature, while the distribution between the weakly attached and the detached within the disordered population is mainly affected by ionic strength. Some other notable features in the diffraction patterns include a approximately 1% decrease in the pitch of the myosin helix as the temperature is raised from 4 degrees C to 20 degrees C.

Control of life-threatening haemorrhage from the neck: a new indication for balloon tamponade

We report the use of a Foley catheter, placed through the wound, to provide balloon tamponade of major bleeding from the neck and supraclavicular fossae. In 10 consecutive explorations for exsanguinating injury in these regions balloon tamponade was used eight times, and was judged to be fully effective in four patients, partly effective in one, and ineffective in three patients.

Influence of extraction technique on the anti-oxidative potential of hawthorn (Crataegus monogyna) extracts in bovine muscle homogenates

Six extracts were prepared from hawthorn (Crataegus monogyna) leaves and flowers (HLF) and berries (HB) using solid-liquid [traditional (T) (HLFT, HBT), sonicated (S) (HLFS, HBS)] and supercritical fluid (C) extraction (HLFC, HBC) techniques. The antioxidant activities of HLF and HB extracts were characterised using in vitro antioxidant assays (TPC, DPPH, FRAP) and in 25% bovine muscle (longissimus lumborum) homogenates (lipid oxidation (TBARS), oxymyoglobin (% of total myoglobin)) after 24h storage at 4°C. Hawthorn extracts exhibited varying degrees of antioxidant potency. In vitro and muscle homogenate (TBARS) antioxidant activity followed the order: HLFS>HLFT and HBT>HBS. In supercritical fluid extracts, HLFC>HBC (in vitro antioxidant activity) and HLFC≈HBC (TBARS). All extracts (except HBS) reduced oxymyoglobin oxidation. The HLFS extract had the highest antioxidant activity in all test systems. Supercritical fluid extraction (SFE) exhibited potential as a technique for the manufacture of functional ingredients (antioxidants) from hawthorn for use in muscle foods.

Detection of a vasoconstrictor factor in stroma-free haemoglobin solutions

Polymerised pyridoxylated haemoglobin solution (PPSFH) is a modified haemoglobin solution which has a normal oxygen carrying capacity, long half-life, and reasonable oxygen affinity, and is a leading candidate for use as an oxygen carrying blood substitute. Previous work has given indications that vasoactive factors may be present. A bioassay sensitive to vasoconstrictors was constructed. PPSFH prepared by chloroform extraction produced a mean pressure rise of 24.3 mm Hg. PPSFH prepared by a crystallisation method showed a mean rise of 2 mm Hg (p = 0.0004). Unmodified stroma-free haemoglobin (SFH) prepared from platelet- and white cell-free red blood cells showed a mean rise of 32.5 mm Hg. These data indicate that both PPSFH and SFH contain a vasoconstrictor factor which is of low molecular weight, is hydrophilic, and is derived from red blood cells.

Penetrating injury to the gluteal region

Eight cases of life-threatening sequelae of relatively minor penetrating injuries of the gluteal region, involving the gluteal or internal pudendal arteries, are reported. The modes of presentation included exsanguinating external hemorrhage (two), acute false aneurysm (one), and chronic false aneurysm (five). Failure to appreciate the nature of the lesion led to inappropriate initial management in seven instances. This series emphasizes the danger of direct incision of lesions in this region which are suspected of being abscesses that are in fact false aneurysms ("pulsatile abscesses") and demonstrates the need for a high index of suspicion for problems related to these vessels following penetrating trauma to the gluteal region, even if seemingly minor, and the need for adequate investigation and planning before surgery.

Dimensions of pain and analgesic administration associated with coronary artery bypass grafting in an Australian intensive care unit

This descriptive correlation study evaluated the pain intensity, pain distress and morphine consumption in patients recovering from coronary artery bypass grafting (CABG) surgery in an Australian intensive care unit (ICU) and compared patients' pain intensity ratings with ratings of the nursing staff. Forty-three patients and their attending nurses rated patients' pain intensity and pain distress levels at 8-hourly intervals throughout their stay in ICU. A maximum of five assessments was obtained in the first 48 post-operative hours from patients and their nurses. Pain intensity and pain distress were measured using separate 10-point numerical rating scales (NRS). Patients' worst pain intensity scores increased over time in ICU; the amount of opioids they received was small and decreased over time. Significant differences occurred between patients' and nurses' average pain intensity scores at each time point and, except for worst pain intensity measures at the first assessment, nurses consistently underestimated patients' pain. These results indicate that patients in ICU following CABG can experience considerable pain, which is not always relieved. The application of regular systematic pain assessment and improved communication, together with the administration of adequate pain relief are necessary if nurses are to manage patients' pain effectively.

Age-specific haemosporidian infection dynamics and survival in Seychelles warblers

Parasites may severely impact the fitness and life-history of their hosts. After infection, surviving individuals may suppress the growth of the parasite, or completely clear the infection and develop immunity. Consequently, parasite prevalence is predicted to decline with age. Among elderly individuals, immunosenescence may lead to a late-life increase in infection prevalence. We used a 21-year longitudinal dataset from one population of individually-marked Seychelles warblers (Acrocephalus sechellensis) to investigate age-dependent prevalence of the GRW1 strain of the intracellular protozoan blood parasite Haemoproteus nucleocondensus and whether infections with this parasite affect age-dependent survival. We analyzed 2454 samples from 1431 individuals and found that H. nucleocondensus infections could rarely be detected in nestlings. Prevalence increased strongly among fledglings and peaked among older first year birds. Prevalence was high among younger adults and declined steeply until ca 4 years of age, after which it was stable. Contrary to expectations, H. nucleocondensus prevalence did not increase among elderly individuals and we found no evidence that annual survival was lower in individuals suffering from an infection. Our results suggest that individuals clear or suppress infections and acquire immunity against future infections, and provide no evidence for immunosenescence nor an impact of chronic infections on survival.

Deaths from blunt trauma, after arrival at hospital: plus ça change, plus c'est la même chose

In this retrospective review of 94 deaths from blunt trauma occurring after admission to the hospital, in the region of Northern Ireland, for the year of 2001, data is presented with reference to preventable deaths (10%). Comparison is made with previous audit from the year of 1981 (preventable death rate 16%). Adverse events continue to occur in relation to abdominal haemorrhage, and issues pertaining to multidisciplinary care.

Deaths from blunt trauma: a review of 105 cases

This paper reviews 105 fatal cases of blunt trauma, in which death occurred after arrival at hospital. Data are presented with reference to age, sex, nature of injuries and length of stay. An assessment was made as to whether any major lesions remained undiagnosed or were undertreated; 16 per cent of these deaths were found to be due, at least in part, to such lesions.

Toll-like receptor variation in the bottlenecked population of the Seychelles warbler: computer simulations see the 'ghost of selection past' and quantify the 'drift debt'

Balancing selection can maintain immunogenetic variation within host populations, but detecting its signal in a postbottlenecked population is challenging due to the potentially overriding effects of drift. Toll-like receptor genes (TLRs) play a fundamental role in vertebrate immune defence and are predicted to be under balancing selection. We previously characterized variation at TLR loci in the Seychelles warbler (Acrocephalus sechellensis), an endemic passerine that has undergone a historical bottleneck. Five of seven TLR loci were polymorphic, which is in sharp contrast to the low genomewide variation observed. However, standard population genetic statistical methods failed to detect a contemporary signature of selection at any TLR locus. We examined whether the observed TLR polymorphism could be explained by neutral evolution, simulating the population's demography in the software DIYABC. This showed that the posterior distributions of mutation rates had to be unrealistically high to explain the observed genetic variation. We then conducted simulations with an agent-based model using typical values for the mutation rate, which indicated that weak balancing selection has acted on the three TLR genes. The model was able to detect evidence of past selection elevating TLR polymorphism in the prebottleneck populations, but was unable to discern any effects of balancing selection in the contemporary population. Our results show drift is the overriding evolutionary force that has shaped TLR variation in the contemporary Seychelles warbler population, and the observed TLR polymorphisms might be merely the 'ghost of selection past'. Forecast models predict immunogenetic variation in this species will continue to be eroded in the absence of contemporary balancing selection. Such 'drift debt' occurs when a gene pool has not yet reached its new equilibrium level of polymorphism, and this loss could be an important threat to many recently bottlenecked populations.

The impact of conservation-driven translocations on blood parasite prevalence in the Seychelles warbler

Introduced populations often lose the parasites they carried in their native range, but little is known about which processes may cause parasite loss during host movement. Conservation-driven translocations could provide an opportunity to identify the mechanisms involved. Using 3,888 blood samples collected over 22 years, we investigated parasite prevalence in populations of Seychelles warblers (Acrocephalus sechellensis) after individuals were translocated from Cousin Island to four new islands (Aride, Cousine, Denis and Frégate). Only a single parasite (Haemoproteus nucleocondensus) was detected on Cousin (prevalence = 52%). This parasite persisted on Cousine (prevalence = 41%), but no infection was found in individuals hatched on Aride, Denis or Frégate. It is not known whether the parasite ever arrived on Aride, but it has not been detected there despite 20 years of post-translocation sampling. We confirmed that individuals translocated to Denis and Frégate were infected, with initial prevalence similar to Cousin. Over time, prevalence decreased on Denis and Frégate until the parasite was not found on Denis two years after translocation, and was approaching zero prevalence on Frégate. The loss (Denis) or decline (Frégate) of H. nucleocondensus, despite successful establishment of infected hosts, must be due to factors affecting parasite transmission on these islands.

Deaths (144) from road traffic accidents occurring before arrival at hospital

One hundred and forty-four deaths occurring as a result of road traffic accidents are reported, with reference to circumstance of accident, cause of death, severity of injury and blood alcohol levels. In seven cases there may have been a contribution to death from aspiration of blood or vomit. In two other cases there were lesions which might have responded to the very early provision of full medical care.

Oxygen transport by a modified haemoglobin solution (PPSFH) in a dog model of acute anaemia following hypovolaemia

Polymerised pyridoxylated stroma free haemoglobin (PPSFH) is a potential red cell substitute. We compared PPSFH to Succinylated Gelatin (SG) and autologous fresh blood (AFB) in a dog model. Three groups of dogs were subjected to a period of fluctuating hypovolaemia. Eight received AFB and had a final haematocrit (Hct) of 54% and total active haemoglobin level (WBod Hb) of 16.5 g/dl. Eight received SG, had a final Hct of 20% and WBod Hb of 5.6 g/dl. Eight received PPSFH, had a final Hct of 20% and a WBod Hb of 10.4 g/dl. Those dogs receiving AFB responded to the hypovolaemic stress by raising oxygen consumption by 27%, whereas in both those receiving SG and PPSFH, oxygen consumption fell by 15% (p = 0.007). In the PPSFH group the PPSFH carried 43% of oxygen consumed. Thus, although PPSFH provided a higher circulating haemoglobin level than SG and carried a high proportion of oxygen consumed, it did not confer any advantage in terms of bulk oxygen transport.

Surgical trainees' attitudes to laparoscopic cholecystectomy: a regional survey

BACKGROUND AND STUDY AIMS

Since the introduction of laparoscopic cholecystectomy (LC), numerous articles have been written emphasising its many advantages over open cholecystectomy (OC). However, reports also highlight increased complications following LC such as bile-duct, vascular and bowel injuries. We aimed to study surgical trainees as a defined population of individuals who, with increasing exposure to cholecystectomy, would become fully aware of LC's advantages and controversies. We wished to test the hypothesis that, with increasing in-depth knowledge, they might opt for OC rather than LC if they themselves required cholecystectomy.

MATERIALS AND METHODS

We conducted a postal survey of all 133 Northern Ireland surgical trainees identified as having exposure to LC during their training. Trainees were asked whether they would undergo LC and if so with which preconditions. Similarly, if they stated a preference for open cholecystectomy they were asked to state the reason. A minimum time period of 18 months was considered adequate for trainees to become relatively more experienced in this field compared with their more junior counterparts.

RESULTS

A response rate of 80.5% (107/133) was achieved. A total of 51 of 107 trainees had at least 18 months' experience. Of the 107 who replied, 88.8% (95/107) would be willing to undergo LC. A total of 12 of 107 trainees would opt for OC, with twice as many experienced trainees (8 vs. 4) opting for this approach (n.s. [not significant]). Significantly more experienced trainees cited the use of laparoscopic cholangiography as a precondition for LC compared with their inexperienced counterparts (7 vs. 1, p = 0.020). Of 107 trainees, 19 would request use of the open first port (Hasson) technique; 14 of these had at least 18 months' experience (p = 0.009).

CONCLUSION

Our survey confirms that the majority of trainees would be willing to undergo LC. However, increased experience of LC may alter an individual's expectations about how LC should ideally be performed.

Adenocarcinoma of the distal duodenum: two cases managed by pylorus preserving pancreatico-duodenectomy and adjuvant chemotherapy

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