Self-recognition in corals facilitates deep-sea habitat engineering.

The ability of coral reefs to engineer complex three-dimensional habitats is central to their success and the rich biodiversity they support. In tropical reefs, encrusting coralline algae bind together substrates and dead coral framework to make continuous reef structures, but beyond the photic zone, the cold-water coral Lophelia pertusa also forms large biogenic reefs, facilitated by skeletal fusion. Skeletal fusion in tropical corals can occur in closely related or juvenile individuals as a result of non-aggressive skeletal overgrowth or allogeneic tissue fusion, but contact reactions in many species result in mortality if there is no 'self-recognition' on a broad species level. This study reveals areas of 'flawless' skeletal fusion in Lophelia pertusa, potentially facilitated by allogeneic tissue fusion, are identified as having small aragonitic crystals or low levels of crystal organisation, and strong molecular bonding. Regardless of the mechanism, the recognition of 'self' between adjacent L. pertusa colonies leads to no observable mortality, facilitates ecosystem engineering and reduces aggression-related energetic expenditure in an environment where energy conservation is crucial. The potential for self-recognition at a species level, and subsequent skeletal fusion in framework-forming cold-water corals is an important first step in understanding their significance as ecological engineers in deep-seas worldwide.

Mitochondrial gene rearrangements confirm the parallel evolution of the crab-like form.

The repeated appearance of strikingly similar crab-like forms in independent decapod crustacean lineages represents a remarkable case of parallel evolution. Uncertainty surrounding the phylogenetic relationships among crab-like lineages has hampered evolutionary studies. As is often the case, aligned DNA sequences by themselves were unable to fully resolve these relationships. Four nested mitochondrial gene rearrangements--including one of the few reported movements of an arthropod protein-coding gene--are congruent with the DNA phylogeny and help to resolve a crucial node. A phylogenetic analysis of DNA sequences, and gene rearrangements, supported five independent origins of the crab-like form, and suggests that the evolution of the crab-like form may be irreversible. This result supports the utility of mitochondrial gene rearrangements in phylogenetic reconstruction.

Multiple origins of eusociality among sponge-dwelling shrimps (Synalpheus).

As the most extreme expression of apparent altruism in nature, eusociality has long posed a central paradox for behavioral and evolutionary ecology. Because eusociality has arisen rarely among animals, understanding the selective pressures important in early stages of its evolution remains elusive. Employing a historical approach to this problem, we used morphology and DNA sequences to reconstruct the phylogeny of 13 species of sponge-dwelling shrimps (Synalpheus) with colony organization ranging from asocial pair-bonding through eusociality. We then used phylogenetically independent contrasts to test whether sociality was associated with evidence of enhanced competitive ability, as suggested by hypotheses invoking an advantage of cooperation in crowded habitats. The molecular, morphological, and combined data each strongly supported three independent origins of monogynous, multigenerational (eusocial) colony organization within this genus. Phylogenetically independent contrasts confirmed that highly social taxa, with strong reproductive skew, have significantly higher relative abundance within the host sponge than do less social taxa, a result that was robust to uncertainty in tree topology and varying models of character change. A similar tendency for highly social species to share their sponge with fewer congener species was suggestive, but not significant. Because unoccupied habitat appears to be limiting for many sponge-dwelling shrimp species, these data are consistent with hypotheses that cooperative social groups enjoy a competitive advantage over less organized groups or individuals, where independent establishment is difficult, and that enemy pressure is of central importance in the evolution of animal sociality.

Hepatitis B and hepatitis C virus infections: risk factors among drug users in Northwest England.

OBJECTIVES: to identify the risk factors for hepatitis B (HBV) and hepatitis C (HCV) virus infections in drug users attending two drug treatment centres in Northwest England, and to evaluate the effect of both needle exchange and hepatitis B vaccination on the prevalence of hepatitis B and hepatitis C infections. METHODS: a retrospective, cross-sectional study performed at the Regional Infectious Disease Unit and a Primary Care Centre for drug users in Liverpool. The study population included 773 drug users who had hepatitis serology performed between January 1992 and April 1996. Information on risk factors was obtained from clinical records; hepatitis serology data were obtained from the Liverpool Public Health Laboratory database. RESULTS: the overall seroprevalences of exposure markers for HBV (anti-HBc antibody) and HCV (anti-HCV antibody) were 48% and 67%, respectively. Duration of injecting drug use was the strongest predictor of HCV infection, with a crude odds ratio of 8.9 (95% confidence interval (CI): 4.5-17) for >10 compared to <3 years of injecting, and was also a strong predictor of HBV infection, with an adjusted odds ratio (controlled for the effects of HBV vaccination) of 5.7 (95% CI: 3.2-10) for >10 compared to <3 years' injecting. Vaccination against HBV was associated with greatly reduced HBV seroprevalence (crude odds ratio 0.11, 95% CI: 0.06-0.18). Overall, HCV was acquired earlier in the injecting career than HBV, but drug users who were not vaccinated against HBV acquired markers for HBV even more rapidly than for HCV. We found no independent protective effect for either anti-HBc or anti-HCV acquisition after the introduction of a needle-exchange scheme. CONCLUSIONS: hepatitis C is highly prevalent among Merseyside drug users and is likely to prove difficult to control because of rapid acquisition early in the injecting career. Vaccination against hepatitis B is the best means of protecting drug users from hepatitis B, and should be offered before injecting is commenced.

Serological survey of chlamydial antibody in post-natal sera.

Questionnaires (3426; 72.8%) and blood samples (3890; 82.6%) were analysed from 4704 women post-natally. The answers to the questionnaire confirmed that those patients living in areas with the highest percentage employed in agriculture were most likely to be in direct or indirect contact with sheep or sheep products. When the 788 (20.3%) of the sera with group specific antibody were examined for type-specific antibody, 291 (7.5%) reacted with Chlamydia trachomatis, 153 (3.9%) with Chlamydia pneumoniae, but only one (0.03%) with Chlamydia psittaci. Thus, it would appear that C. psittaci was not an important pathogen in this survey, despite the largest proportion of blood samples being submitted from those most likely to be employed in agriculture. However, in the course of this survey the three patients who had previously suffered chlamydia-associated abortion had successful pregnancies and submitted blood specimens. Serological studies on the serial bloods from these patients showed that, despite developing antibody to the C. psittaci pool and the ovine abortion strain of C. psittaci following abortion, this antibody waned. At the time of the subsequent successful pregnancy, serological results would not have detected a previous C. psittaci infection, but one due to C. pneumoniae. Thus, the results of a survey such as this must be interpreted with caution.

A survey of the management of neonatal opiate withdrawal in England and Wales.

UNLABELLED: This report details the results of a survey of 213 maternity units in England and Wales concerning the use of neonatal opiate withdrawal (NOW) charts and the drug therapy management of babies born to drug using mothers. There was a response rate of 89.6%. NOW charts were used in 36.6% of units. There were eight different charts in use in which over 35 different signs of NOW were recorded, ranging from 10 to 22 on individual charts. Nine different drugs were used to manage NOW, with chlorpromazine most commonly used. CONCLUSION: Drug misuse increasing in women of childbearing age and the management of the drug affected neonate varies widely, with inconsistent policies on determining the presence of NOW and how to treat it.

The development of healthcare services for drug misusers and prostitutes.

With the advent of human immunodeficiency virus (HIV) and the increase of drug misuse in the UK, the Government wishes primary care to play a greater part in treating drug problems in the hope of preventing the spread of HIV. Drug misusers do not avail themselves of traditional services and many are not registered with general practitioners. In response to this Liverpool Health Authority and Family Health Service Authority commenced a new salaried post to provide primary care services to special groups such as injecting drug misusers and prostitutes. Judgemental attitudes towards drug misusers, their high mobility and being a transient population play a part in the reasons why drug misusers find it difficult to access primary healthcare. Drug misusers have high morbidity related to their drug misuse. Many of these conditions, if treated early, can prevent the need for more intensive intervention. Although drug misusers may present with a condition requiring immediate treatment, the opportunity is used to provide other healthcare such as hepatitis B vaccinations, sexually transmitted infection screening, contraception and HIV/hepatitis B testing. The sero prevalence of anti-HBc in injecting drug misusers is 45.5%. Due to their high morbidity and associated costs, the requirements of these groups may conflict with the objectives of budget-holding practices. If general practitioners are unable to respond to their problems, then health care providers and purchasers will have to consider similar schemes in areas which have a higher prevalence of drug misuse in order to provide appropriate healthcare for these vulnerable groups.

Female sexual health problems in a drug dependency unit.

The Government of the United Kingdom has produced a strategic plan called the Health of the Nation aimed at achieving better health in key areas including a reduction in rates of unwanted pregnancies, sexually transmitted diseases and cervical cancer. Conventional health care systems fail some groups with special needs. This cross-sectional interview study was undertaken to determine the level and type of contraceptive use, and the attitudes of female opiate abusers to the use and availability of contraceptives and cytology services. The subjects were 201 opiate-dependent women enrolled in a methadone maintenance programme in a large drug dependency unit: 169 (84.5%) were sexually active and 65 (44.2%) of non-pregnant sexually active women did not use a contraceptive method. Thirty-six (43.9%) of those using a contraceptive were using condoms, with which the majority were dissatisfied. Sixty-one (30.3%) had never had a cervical cytology smear and of those who had, 21.4% reported an abnormal result. The contraceptive practices and uptake of cervical screening services by the women studied are inadequate, reflecting poor use of conventional health care services. In addition to providing information on safer sexual practices, particularly promotion of condom use, we suggest that drug dependency units should expand their role to provide educational and preventative services to include aspects of women's health.

Anabolic steroid users identified by needle and syringe exchange contact.

The increasing prevalence in the extent of misuse of anabolic-androgenic steroids has been well recognised in the United States and more recently in Great Britain. The injecting misuse of steroids carries with it considerable risks in relation to liver damage, lipid metabolism disturbance and the potential of HIV and viral hepatitis transmission. This study of 21 steroid users contacted at a needle and syringe exchange showed that 42.8% had abnormal liver function tests and 28.5% had lowered high-density lipoprotein concentrations. None of this group reported engaging in high risk behaviour through sharing injecting equipment. The group did contain a bisexual and a previous injecting amphetamine user. Needle and syringe exchanges offering health examination facilities will provide a valuable role in contacting steroid users who will then be in a position to make informed decisions about their own drug use and the potential harm from steroids.

Use of a commercial PCR kit for detecting Chlamydia trachomatis.

AIMS: To evaluate a commercial polymerase chain reaction (PCR) kit for the detection of Chlamydia trachomatis. METHODS: Two hundred and fifty seven genital specimens, which had been submitted in 2SP medium for chlamydial isolation and subsequently stored at -70 degrees C, were retrospectively examined by a commercial PCR kit which detects chlamydial plasmid DNA. Culture negative, PCR positive specimens were examined by immunofluorescence and an in-house major outer membrane protein (MOMP)-PCR. RESULTS: All 49 specimens which were culture positive were also PCR positive. Another 14 specimens were also PCR positive. After resolution of these results by immunofluorescence and a PCR assay for MOMP the sensitivity for PCR was 98.4% and that of culture 79%. The specificities were 99.5% and 100%, respectively. CONCLUSIONS: This kit, which is highly sensitive and specific, is straightforward to use and has a built-in safeguard against cross contamination. The role of this test in the examination of routine genital specimens from patients with uncomplicated chlamydial infection is questionable due to its expense. It may have a place in the investigation of trachoma or infertility, however, where it has been shown that DNA can be detected when culture is unsuccessful.

Temazepam misuse in a group of injecting drug users.

It is well recognized that many injecting drug users are poly-drug users. The intravenous use of Temazepam has become popular recently. In response to the ease of misuse, the pharmaceutical industry produced a formulation that would be as 'resistant' as possible to injecting. The preparation is a gel-filled formulation, one proprietary name being Temazepam Gelthix. General Practitioners have been encouraged to prescribe gel-filled capsules to potential drug misusers in order to reduce the harm Temazepam can cause by its misuse. This study of 23 Temazepam injectors shows that the group still find the gel-filled preparation readily injectable. It appears to be more problematic in causing medical complications including superficial thrombophlebitis, abscesses and deep venous thrombosis. Temazepam misuse can cause drug users to become more chaotic. The study group recognize this and suggest there should be stricter control on the supply of Temazepam to drug dependents. General Practitioners, who are the main source of Temazepam prescribing, require additional training in prescribing to drug users.

Determinants of pediatric injuries.

Injuries are an important health issue for children. Previous research, however, has presented confusing and conflicting results on the determinants of childhood injuries, particularly psychosocial predictors, largely due to methodologic problems. The purpose of this analysis, based on a prospective follow-up study of 532 children, was to identify factors related to injuries encountered in a prepaid group practice during a 12-month period. Using logistic regression, we found four factors independently associated with the risk of at least one treated injury: high activity level, high rate of pediatric utilization for non-injury-related visits during the follow-up period, occurrence of a treated injury during the year preceding the follow-up period, and negative attitude toward medical care providers by the child's mother. In addition, four factors were found to be independent predictors of injuries judged severe enough to always warrant medical care: occurrence of a treated injury in the preceding year, high rate of pediatric utilization for non-injury-related visits during the follow-up period, working more than 15 hours a week outside the home by the child's mother, and more life events reported by the mother for the year preceding the follow-up period. Since family stressors are related specifically to the risk of more severe injuries, which are unlikely to escape medical attention, we conclude that these factors probably are related to the occurrence of common injuries of early childhood and not exclusively to utilization behavior. We therefore suggest that children from families with these characteristics be targeted for injury prevention strategies.