Enhancement of Fas ligand-induced inhibition of neointimal formation in rabbit femoral and iliac arteries by coexpression of p35

Adenovirus-mediated gene transfer of Fas ligand (FasL) inhibits neointimal formation in balloon-injured rat carotid arteries. Vascular smooth muscle (VSM) cells coexpressing murine FasL and p35, a baculovirus gene that inhibits caspase activity, are not susceptible to FasL-mediated apoptosis in vitro but are capable of inducing apoptosis of VSM cells that do not express p35. We reasoned that coexpression of p35 in FasL-transduced VSM cells in vivo would promote their survival, enhance FasL-induced apoptosis of adjacent VSM cells, and thereby facilitate a greater inhibition of neointimal formation. In balloon-injured rabbit femoral arteries, either Ad2/FasL/p35 or Ad2/FasL was infused into the injured site and withdrawn 20 min later. Both vectors induced a dose-dependent reduction (p < 0.05) of the neointima-to-media ratio when assessed 14 days later. However, Ad2/FasL/p35 exhibited a significantly greater inhibition of neointimal formation than Ad2/FasL. In a more clinically relevant model of restenosis, rabbit iliac arteries were injured with an angioplasty catheter under fluoroscopic guidance. Adenoviral vectors were delivered locally to the injured site over a period of 2 min, using a porous infusion balloon catheter. Twenty-eight days after gene transfer angiographic and histologic assessments indicated a significant (p < 0.05) inhibition of iliac artery lumen stenosis and neointimal formation by Ad2/FasL/p35 (5 x 10(11) particles per artery). The extent of inhibition was comparable to that achieved with Ad2/TK, an adenoviral vector encoding thymidine kinase (5 x 10(11) particles per artery) and coadministration of ganciclovir for 7 days. These data suggest that coexpression of p35 in FasL-transduced VSM cells is more potent at inhibiting neointimal formation and as such represents an improved gene therapy approach for restenosis.

Gastric lipoma causing gastroduodenal intussusception

A case of gastroduodenal intussusception caused by a submucosal gastric lipoma in a 48-year-old man is presented. He had intermittent symptoms of regurgitation and heartburn for a period of three years. Barium meal and CT scan showed a mass in the first part of duodenum. At laparotomy there was intussusception of gastric antrum into the duodenum with a submucosal lipoma in the antrum which formed the apex of the intussusception.

Quasi-periodic substructure in the microvessel endothelial glycocalyx: a possible explanation for molecular filtering?

The luminal surface of endothelial cells is lined with the glycocalyx, a network structure of glycoproteins probably 50 to 100 nm thick. It has been suggested that a relatively regular fibre-matrix structure may be responsible for the ultrafiltration properties of microvascular walls, both when the endothelium is continuous and when it is fenestrated. Positive structural evidence demonstrating an underlying periodicity in the glycocalyx has been hard to obtain. Here we present structural analysis of glycocalyx samples prepared in a variety of ways for electron microscopy. Using computed autocorrelation functions and Fourier transforms of representative areas of the electron micrograph images, we show that there is an underlying three-dimensional fibrous meshwork within the glycocalyx with characteristic spacings of about 20 nm. Together with a fibre diameter consistent with our observations of about 10-12 nm, the 20-nm spacing provides just the size regime to account satisfactorily for the observed molecular filtering; the observations are consistent with the fibre matrix model. We also show that the fibrous elements may occur in clusters with a common intercluster spacing of about 100 nm and speculate that this may reveal organisation of the glycocalyx by a quasi-regular submembranous cytoskeletal scaffold.

Prevalence of antibodies to hepatitis B, hepatitis C, and HIV and risk factors in entrants to Irish prisons: a national cross sectional survey

OBJECTIVES

To determine the prevalence of antibodies to hepatitis B core antigen, hepatitis C virus, and HIV in entrants to Irish prisons and to examine risk factors for infection.

DESIGN

Cross sectional, anonymous survey, with self completed risk factor questionnaire and oral fluid specimen for antibody testing.

SETTING

Five of seven committal prisons in the Republic of Ireland.

PARTICIPANTS

607 of the 718 consecutive prison entrants from 6 April to 1 May 1999.

MAIN OUTCOME MEASURES

Prevalence of antibodies to hepatitis B core antigen, hepatitis C virus, and HIV in prison entrants, and self reported risk factor status.

RESULTS

Prevalence of antibodies to hepatitis B core antigen was 37/596 (6%; 95% confidence interval 4% to 9%), to hepatitis C virus was 130/596 (22%; 19% to 25%), and to HIV was 12/596 (2%; 1% to 4%). A third of the respondents had never previously been in prison; these had the lowest prevalence of antibodies to hepatitis B core antigen (4/197, 2%), to hepatitis C (6/197, 3%), and to HIV (0/197). In total 29% of respondents (173/593) reported ever injecting drugs, but only 7% (14/197) of those entering prison for the first time reported doing so compared with 40% (157/394) of those previously in prison. Use of injected drugs was the most important predictor of antibodies to hepatitis B core antigen and hepatitis C virus.

CONCLUSIONS

Use of injected drugs and infection with hepatitis C virus are endemic in Irish prisons. A third of prison entrants were committed to prison for the first time. Only a small number of first time entrants were infected with one or more of the viruses. These findings confirm the need for increased infection control and harm reduction measures in Irish prisons.

Structure of a variant of lac repressor with increased thermostability and decreased affinity for operator

A single amino acid substitution, K84L, in the Escherichia coli lac repressor produces a protein that has substantially increased stability compared to wild-type. However, despite the increased stability, this altered tetrameric repressor has a tenfold reduced affinity for operator and greatly decreased rate-constants of inducer binding as well as a reduced phenotypic response to inducer in vivo. To understand the dramatic increase in stability and altered functional properties, we have determined the X-ray crystal structures of a dimeric repressor with and without the K84L substitution at resolutions of 1.7 and 3.0 A, respectively. In the wild-type dimer, K84-11, Lys84 forms electrostatic interactions at the monomer-monomer interface and is partially exposed to solvent. In the K84L-11 substituted protein there is reorientation of the N-subdomains, which allows the leucine to become deeply buried at the monomer-monomer interface. This reorientation of the N-subdomains, in turn, results in an alteration of hydrogen bonding, ion pairing, and van der Waals interactions at the monomer-monomer interface. The lysine residue at position 84 appears to exert its key effects by destabilizing the "optimal" conformation of the repressor, effectively loosening the dimer interface and allowing the repressor to adopt the conformations necessary to function as a molecular switch.

Psychological model for judicial decision making in emergency or temporary child placement

In emergencies, family court judges must often make rapid decisions, without benefit of thorough information, that have significant impact on people's lives. Action-oriented research was used to develop a model that would bring psychosocial factors to the legal system for the purpose of enhancing the judicial decision-making process in emergency and temporary child placement cases.

Syringe borrowing persists in Dublin despite harm reduction interventions

AIMS

To measure the frequency of syringe borrowing in young Irish injecting drug users (IDUs) and identify associated characteristics.

DESIGN

Cross-sectional survey.

SETTING

Addiction treatment services in Dublin.

PARTICIPANTS

Treated IDUs (N = 246).

MEASUREMENTS

Data on drug injecting and syringe borrowing in the previous 6 months.

FINDINGS

The median age was 22 years and the median length of injecting history was 19 months. Syringe borrowing was reported by 173 (70.3%) participants. A multivariate analysis identified seven characteristics significantly associated with syringe borrowing. These included early school leaving and parental unemployment. IDUs with long injecting histories who had injected less frequently were more likely to borrow. Injection of more than one substance was significantly associated with borrowing of syringes. Syringe borrowing was associated with having more intimate social relationships with other IDUs, less perceived risk in borrowing from acquaintances and usually opting to inject in the company of other IDUs.

CONCLUSIONS

Syringe borrowing is commonly practised by young IDUs. Those with a background of social deprivation are more likely to engage in this risk behaviour. IDUs who report borrowing are more intimately involved with other IDUs and tend to perceive less risk or dangerousness in borrowing. In addition to syringe exchange, there is a need to work cognitively with IDUs to identify and challenge assumptions that they may have regarding the safety involved in borrowing from others, particularly from those with whom they have close social relationships.

Epidemiological studies of human and animal Salmonella typhimurium DT104 and DT104b isolates in Ireland

A total of 122 human and animal Salmonella Typhimurium DT104 isolates and 6 epidemiologically related DT104b isolates from human and animal products were analysed by pulsed-field gel electrophoresis (PFGE). Genomic DNA was subjected to macrorestriction with three enzymes, SpeI, SfiI and XbaI. A total of 14 restriction fragment length polymorphism (RFLP) profiles were identified when the PFGE patterns from the three enzymes were combined. The majority of isolates (81.2%) exhibited the same RFLP profile. Six animal DT104 isolates, susceptible to enrofloxacin and resistant to naladixic acid, were identified from the antibiotic susceptibility test. Four of these isolates had a different PFGE profile from the common RFLP. In addition, 4 of the 6 isolates were geographically clustered in one region. It was concluded that there was one predominant strain of S. Typhimurium DT104 in Ireland and that the potential and selection pressures for emergence of fluoroquinolone-resistant isolates were present.

A two-platform task reveals a deficit in the ability of rats to return to the start location in the water maze

The ability of rats to return to the start location was examined with a 4-arm radial water maze. The task required rats to find 2 hidden platforms in sequence. Rats were released from 1 of 3 arms and there was a platform located in the fourth arm. Once a rat found this platform, a 2nd platform was raised in another location, which was either the start location, for 1 group, or another fixed location, for a control group. Across 3 experiments, all rats learned the location of the 1st fixed platform in 80 to 120 trials. However, rats had difficulty finding a 2nd platform if it was at the start location. Control groups revealed that rats could learn 2 platform locations and that the difficulty in learning to return to the start location did not seem to be attributable to its aversive nature. In separate groups, exposure to the start location was increased by starting the rats from an initially stable platform. Rats still did not readily learn to return to the start location. The authors suggest that start location, when varied, cannot readily be used to define the location of a hidden platform.

An analysis of 15-19-year-old first attenders at the Dublin Needle Exchange, 1990-97

AIMS

Identification of characteristics and trends over time in young injecting drug users at first attendance at needle exchange.

DESIGN

Retrospective cross-sectional survey of routinely collected data.

SETTING

Dublin needle exchange programme which consists of 11 sites in the greater Dublin area.

PARTICIPANTS

First-time attenders (n = 1224) at the needle exchange from 1990 to 1997, between the ages of 15 and 19.

MEASUREMENT

Factors associated with a likelihood of needle sharing and condom use were tested using logistic regression.

FINDINGS

Increases in both the number and proportion of young injectors, particularly young female injectors, have occurred over the 8 years. Forty-eight per cent of the young injectors were injecting for less than 1 year. Needle sharing prevalence in the year previous to first attendance was 39% and condom use was 61%. The proportion of females not using a condom during sexual relationships was significantly higher than males. Very few of the young attenders had received any treatment for drug dependence.

CONCLUSIONS

After the first year of injecting drug use the likelihood of needle sharing increased and we recommend that interventions occur early on and are targeted to the needs of young injecting drug users, in particular young females. It is essential that services are accessible to the young injecting drug user and that barriers to contact with services are minimized or eliminated. Some high-risk behaviours are occurring in the context of the sexual relationship and this should be taken into account when designing prevention programmes, especially for young females.

Opiate-related deaths in Dublin

BACKGROUND

Intravenous drug misuse, principally heroin, occurs primarily in the Greater Dublin area. Methadone maintenance treatment has been an important part of the response to opiate misuse in Dublin since 1992.

AIMS

To determine the number of opiate-related deaths in Dublin City and County during 1999, to establish the number of methadone-related deaths and determine the proportion of deaths associated with methadone prescribed according to guidelines.

METHODS

A retrospective review of all coroners' inquest files in Dublin City and County during 1999 was undertaken.

RESULTS

There were 84 opiate-related deaths. Seventy-eight (92.9%) were male. Seventy-three (86.9%) had two or more drugs identified toxicologically. There were 45 methadone-related deaths, of which 15 (33.3%) were receiving methadone prescribed according to guidelines.

CONCLUSION

Opiate-related deaths occur primarily in males in the 25-34 year age group and are associated with a high level of polydrug use. Diverted methadone accounted for the majority of deaths involving

Blood-borne infections in Dublin's opiate users

BACKGROUND

Injecting drug users are at high risk of acquiring blood-borne infections. Ireland has had a harm reduction policy of methadone maintenance and needle exchange since 1992.

AIM

To estimate prevalence of hepatitis B, hepatitis C and HIV infection and appropriate uptake of hepatitis B vaccine in methadone attendees and to make recommendations for a simple record-based surveillance system.

METHOD

Retrospective study of 138 client records for evidence of laboratory tests or test results for blood-borne viruses and appropriate immunisation against hepatitis B.

RESULTS

A total of 60% of clients had evidence of one or more laboratory tests in their notes. Of those tested for individual viruses, 5.1% were positive for hepatitis B surface antigen, 78.8% had antibodies to hepatitis C and 16.7% were HIV positive. Nearly two-thirds of clients had no evidence of vaccination or information on prior immunity in their records.

CONCLUSIONS

A standardised written protocol for screening for blood-borne viruses and for immunisation against hepatitis B in methadone service attendees was clearly needed, and was subsequently introduced by the Eastern Region Health Authority.

Comparison between self-reported hepatitis B, hepatitis C, and HIV antibody status and oral fluid assay results in Irish prisoners

Self-reported hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV infection status was compared with the results of oral fluid assays of antibodies to these viruses in prisoners from nine of the 15 prisons in the Republic of Ireland. A total of 1205 out of 1366 prisoners completed a confidential questionnaire and 1193 provided analysable oral fluid specimens for testing for antibodies to HBV core antigen (anti-HBc), HCV (anti-HCV), and HIV (anti-HIV). The self-reported prevalence of hepatitis infection (hepatitis B: 5%; hepatitis C: 19%) was lower than that derived from oral fluid assays (anti-HBc: 9%; anti-HCV: 37%). The self-reported prevalence of HIV infection was similar to that found by oral fluid assay (2%). Many discrepancies were found between self-reported results and the results of oral fluid assays. Of those who reported being positive for HBV, HCV, or HIV, 48%, 5%, and 58%, respectively, tested negative on the oral fluid assay. Of those who reported a previous negative test result for HBV, HCV, or HIV, 10%, 37%, and 2%, respectively, had positive oral fluid assays. Self-reports of hepatitis and HIV infection status are unreliable and should not be used as a basis for planning preventive and treatment services for prisoners. All prisoners should have the opportunity to be tested for HBV, HCV, and HIV infection.

Drug users attending general practice in Eastern Regional Health Authority (ERHA) area

Dublin has an estimated 13,460 opiate drug users. The role of general practice in providing care for this group has increased over the last four years. A Central Methadone Treatment List (CMTL) registers all clients currently on treatment. To obtain a social, demographic and drug using profile of opiate users attending general practitioners (GPs) for methadone maintenance. A cross sectional survey of opiate users attending general practice for methadone maintenance in the Dublin area in early 1999. Data was collected on 571 clients (62% of total number attending general practice), of whom 97% had used heroin in the past and 12% had never injected. Although clients had been receiving methadone maintenance in general practice for a mean of 14 months, 16% were still using heroin, of whom 31% were still injecting. The mean age of first drug use was 15.5 years and of first injecting was 19.4 years. Younger clients are starting both to use drugs and inject drugs at an earlier age. Record keeping was good, with most items of information present in over 70% of the charts surveyed. A total of 17% of clients recorded on the CMTL could not be traced to the GP recorded as providing care. Despite treatment with methadone maintenance, there is a high level of continued risk activity in this group. Furthermore, a trend towards earlier initiation to drug use is apparent. The CMTL registration process requires further exploration.

The laryngeal mask for percutaneous endoscopic gastrostomy

IMPLICATIONS

We report the successful use of the laryngeal mask airway for percutaneous endoscopic gastrostomy in an adult patient with a known difficult airway and severe cerebral palsy.

Trends in treated opiate misuse in Dublin: the emergence of chasing the dragon

AIMS

To examine trends in treated opiate misuse and identify factors associated with route of heroin use.

DESIGN

Cross-sectional survey.

SETTING

Services providing addiction treatment in Dublin.

PARTICIPANTS

Individuals making their first ever contact seeking treatment for current opiate misuse, between January 1991 and December 1996.

MEASUREMENTS

Data on socio-demographics and current drug use.

FINDINGS

The study population was 3981. Over the 6-year period, there was a 330% increase in the number of new attenders. The proportion of females increased. The mean age of first opiate use declined and users began presenting earlier in their opiate-using careers, causing a decline in the age profile of new attenders. Heroin users were more likely to smoke (chase) rather than inject after 1994 (odds ratio 3.3, 95% confidence interval 2.4-4.5). Apart from year of presentation, the other significant independent predictors of chasing as the preferred route of heroin use were being in employment, shorter history of use, less frequent use, younger age, longer period in education and absence of polydrug use. Gender did not independently predict route of use.

CONCLUSIONS

Ireland has joined the growing number of European countries witnessing a movement towards heroin chasing. This has coincided with a surge in the number of people entering treatment. We are concerned that the greater acceptability of this route of use may be drawing increased numbers of individuals into heroin use.

Prevalence of antibodies to hepatitis B, hepatitis C, and HIV and risk factors in Irish prisoners: results of a national cross sectional survey

OBJECTIVES

To determine the prevalence of antibodies to hepatitis B core antigen, hepatitis C virus, and HIV in the prison population of the Republic of Ireland and to examine risk factors for infection.

DESIGN

Cross sectional, anonymous, unlinked survey, with self completed risk factor questionnaire and provision of oral fluid specimen for antibody testing.

SETTING

Nine of the 15 prisons in the Republic of Ireland.

PARTICIPANTS

1366 prisoners, of whom 1205 (57 women) participated. In the smaller prisons all prisoners were surveyed, while in the three largest prisons one half of the population was randomly sampled. Three small prisons believed not to have a problem with injecting drug use were excluded.

MAIN OUTCOME MEASURES

Prevalence of antibodies to hepatitis B core antigen, antibodies to hepatitis C virus, and antibodies to HIV. Self reported risk factor status.

RESULTS

Prevalence of antibodies to hepatitis B core antigen was 104/1193 (8.7%; 95% confidence interval 7.2% to 10.5%), to hepatitis C virus, 442/1193 (37%; 34.3% to 39.9%), and to HIV, 24/1193 (2%; 1.3% to 3%). The most important predictor of being positive for hepatitis B and hepatitis C was a history of injecting drug use. Thirty four women (60%) and 474 men (42%) reported ever injecting drugs. A fifth (104) of 501 injecting drug users reported first injecting in prison, and 347 (71%) users reported sharing needles in prison.

CONCLUSIONS

Infection with hepatitis C secondary to use of injected drugs is endemic in Irish prisons. Better access to harm reduction strategies is needed in this environment.

Pharyngolaryngeal, neck, and jaw discomfort after anesthesia with the face mask and laryngeal mask airway at high and low cuff volumes in males and females

BACKGROUND

There is controversy over (1) the relative incidence of sore throat between the face mask (FM) and laryngeal mask airway (LMA), (2) the efficacy of LMA intracuff pressure reduction as a mechanism for minimizing sore throat, and (3) the relative incidence of sore throat with the LMA between males and females. In a randomized double-blind study, the authors compared laryngopharyngeal, neck, and jaw discomfort with the FM and LMA at high and low cuff volumes in males and females.

METHODS

Three hundred adult patients were randomly assigned to three equal-sized groups for airway management: (1) the FM, (2) the LMA with a fully inflated cuff (LMA-High), or (3) the LMA with a semi-inflated cuff (LMA-Low). Anesthesia was administered with propofol, nitrous oxide, oxygen, and isoflurane. In the FM group, a Guedel-type oropharyngeal airway and jaw thrust were used only if necessary. In the LMA groups, cuff inflation was achieved with either 15 or 30 ml for the size 4 (females) and 20 or 40 ml for the size 5 (males). The LMA was removed when the patient was awake. Patients were questioned 18-24 h postoperatively about surgical pain, sore throat, sore neck, sore jaw, dysphonia, and dysphagia, and about whether they were satisfied with their anesthetic.

RESULTS

The incidence of sore throat was lower in the FM (8%) than the LMA-High (42%) and LMA-Low (20%) groups (both: P < or = 0.02). The incidence of sore neck was higher for the FM (14%) than the LMA-High group (6%; P = 0.05) but similar to the LMA-Low group (8%). The incidence of sore jaw was higher in the FM (11%) than the LMA-High (3%) and LMA-Low (3%) groups (both: P = 0. 02). There were no differences among groups for surgical pain or dysphonia. The incidence of dysphagia was lower in the FM (1%) than the LMA-High group (11%; P = 0.003), but similar to the LMA-Low group (1%). The incidence of sore throat and dysphagia was lower in the LMA-Low group than the LMA-High group for both males and females (all: P < or = 0.04). There were no differences in discomfort levels between males and females in any group. Two patients from the FM group and one from the LMA-High group were not satisfied with their anesthetic. These complaints were unrelated to postoperative morbidity.

CONCLUSION

The LMA causes more sore throat and dysphagia but less jaw pain than the FM. Sore throat and dysphagia are more common with the LMA if the initial cuff volume is high. There are no differences in discomfort levels between males and females. However, these discomforts do not influence patient satisfaction after LMA or FM anesthesia.

Emergence characteristics and postoperative laryngopharyngeal morbidity with the laryngeal mask airway: a comparison of high versus low initial cuff volume

In this study we tested the hypothesis that the initial cuff volume of the laryngeal mask airway influences emergence characteristics and postoperative laryngopharyngeal morbidity. One hundred and sixty adult patients undergoing minor surgery were randomly assigned for airway management with the laryngeal mask airway with either a fully inflated cuff (LMA-High) or a semi-inflated cuff (LMA-Low). Anaesthesia was with propofol, nitrous oxide, oxygen and isoflurane. Following insertion, the cuff was inflated with either 15 or 30 ml for the size 4 (females) and 20 or 40 ml for the size 5 (males). At the end of surgery, a blinded observer documented the presence or absence of adverse airway events (hypoxia, hypercapnea, coughing, retching, regurgitation/vomiting, airway obstruction, hypoventilation, hiccupping, biting, body movement or shivering) during every 1 min epoch and cardiorespiratory variables (heart rate, mean blood pressure, arterial oxygen saturation, end-tidal carbon dioxide and respiratory rate) every 5 min until the patient was awake and the laryngeal mask airway removed. Patients were interviewed about pharyngolaryngeal morbidity (sore throat, dysphonia and dysphagia) immediately before leaving the postanaesthesia care unit and 18-24 h following surgery. Analysis by epoch showed more partial airway obstruction in the LMA-High group, but analysis by patient numbers revealed no difference. Heart rate was slightly higher in the LMA-High group upon arrival in the postanaesthesia care unit, but otherwise there were no differences in cardiorespiratory responses. Sore throat and dysphagia were more common in the LMA-High group. We conclude that, in general, emergence characteristics with the laryngeal mask airway are not influenced by the volume of air used to inflate the cuff, but that postoperative sore throat and dysphagia are more likely at high initial cuff volumes.