Hidden need for drug treatment services: measuring levels of problematic drug use in the North West of England

BACKGROUND

In the North West of England, data on drug users are routinely collected from a variety of agencies including specialist treatment centres, police and probation services. However, the covert nature of drug use means that alone, these conventional monitoring systems cannot provide the epidemiology required to target and develop drug treatment and prevention initiatives.

METHODS

Utilizing surveillance data and capture-recapture techniques we estimate the rates of problematic drug users by age and sex in five North West health authorities and one local authority.

RESULTS

Analyses show concentrations of problematic drug use in large metropolitan areas (Liverpool and Manchester) with levels as high as 34.5 and 36.5 per 1000 population (ages 15-44), respectively, and, for males, levels exceed 50 per 1000 in three authorities. Patterns of prevalence for those aged 25 and over differed from those in the younger age groups, with disproportionate levels of young users outside metropolitan areas. The proportion of young users already in treatment (21.3 per cent) was lower (older users, 35.3 per cent), with overall proportions in treatment varying between health authorities (range 26.2-46.5 per cent).

CONCLUSION

With a multi-agency approach, established monitoring systems can be used to measure hidden populations of drug users. Estimates of the current populations of such users in the North West of England suggest that planned increases of people in treatment by 100 per cent would fail to accommodate even current level of problematic users. A holistic approach to new initiatives must ensure that the high level of relapse once drug users are discharged are reduced and that the needs of young users are addressed before prolonged treatment is required.

Long-term use of a left ventricular assist device for end-stage heart failure

BACKGROUND

Implantable left ventricular assist devices have benefited patients with end-stage heart failure as a bridge to cardiac transplantation, but their long-term use for the purpose of enhancing survival and the quality of life has not been evaluated.

METHODS

We randomly assigned 129 patients with end-stage heart failure who were ineligible for cardiac transplantation to receive a left ventricular assist device (68 patients) or optimal medical management (61). All patients had symptoms of New York Heart Association class IV heart failure.

RESULTS

Kaplan-Meier survival analysis showed a reduction of 48 percent in the risk of death from any cause in the group that received left ventricular assist devices as compared with the medical-therapy group (relative risk, 0.52; 95 percent confidence interval, 0.34 to 0.78; P=0.001). The rates of survival at one year were 52 percent in the device group and 25 percent in the medical-therapy group (P=0.002), and the rates at two years were 23 percent and 8 percent (P=0.09), respectively. The frequency of serious adverse events in the device group was 2.35 (95 percent confidence interval, 1.86 to 2.95) times that in the medical-therapy group, with a predominance of infection, bleeding, and malfunction of the device. The quality of life was significantly improved at one year in the device group.

CONCLUSIONS

The use of a left ventricular assist device in patients with advanced heart failure resulted in a clinically meaningful survival benefit and an improved quality of life. A left ventricular assist device is an acceptable alternative therapy in selected patients who are not candidates for cardiac transplantation.

Effects of charged water-soluble polymers on the stability and activity of yeast alcohol dehydrogenase and subtilisin Carlsberg

Remarkable increases in enzyme catalytic stability resulting from addition of charged water-soluble polymers have recently been reported, suggesting that use of these polymers may be an attractive general strategy for enzyme stabilization. To test the proposed hypothesis that coulombic forces between water-soluble polymers and enzymes are primarily responsible for enzyme stabilization, we examined the catalytic stability and activity of two enzymes in the presence of polymers differing in net charge. All polymers tested increased enzyme lifetimes, regardless of their net charge, suggesting that stabilization of these enzymes by water-soluble polymers is not solely dependent on simple electrostatic interactions between the polymers and enzymes.

Pars plana lentectomy for treatment of congenital cataract

BACKGROUND

Congenital cataract surgery can be performed using a pars plicata/plana or a limbal approach, if placement of an intraocular lens at the time of cataract removal is not a consideration. Because of the high incidence of secondary cataract formation in children the operation should be combined with capsulotomy and anterior vitrectomy.

METHODS

The series consisted of 30 eyes from 20 consecutive children who suffered from congenital cataract and underwent cataract surgery between May 1995 and June 2000. The inclusion criterion was congenital cataract affecting the visual axis. We performed the operations as lens aspiration with anterior and posterior capsulotomy and anterior vitrectomy via the pars plana or plicata. We used contact lenses to rehabilitate vision. All patients received intensive orthoptic and pleoptic treatment.

RESULTS

This surgical technique provided in all eyes a clear visual axis. During follow-up of 3 months to 4.5 years, secondary cataract developed in five eyes. Retinal detachment, glaucoma and endophthalmitis did not occur. One patient developed contact lens intolerance and a secondary intraocular lens was placed in the ciliary sulcus.

DISCUSSION

Lentectomy via a pars plana or pars plicata approach is a suitable and safe method for treating cataract in children. Our chosen method of lentectomy is an alternative to early implantation of an intraocular lens. It is possible to perform uncomplicated secondary implantation of an intraocular lens in the ciliary sulcus.

The natural transformation of the soil bacteria Pseudomonas stutzeri and Acinetobacter sp. by transgenic plant DNA strictly depends on homologous sequences in the recipient cells

The nptII(+) gene present in the genome of transgenic potato plants transforms naturally competent cells of the soil bacteria Pseudomonas stutzeri and Acinetobacter BD413 (both harboring a plasmid with an nptII gene containing a small deletion) with the same high efficiency as nptII(+) genes on plasmid DNA (3x10(-5)-1x10(-4) transformants per nptII(+)) despite the presence of a more than 10(6)-fold excess of plant DNA. However, in the absence of homologous sequences in the recipient cells the transformation by nptII(+) dropped by at least about 10(8)-fold in P. stutzeri and 10(9)-fold in Acinetobacter resulting in the latter strain in < or =1x10(-13) transformants per nptII(+). This indicated a very low probability of non-homologous DNA fragments to be integrated by illegitimate recombination events during transformation.

Apoptosis in development

Essential to the construction, maintenance and repair of tissues is the ability to induce suicide of supernumerary, misplaced or damaged cells with high specificity and efficiency. Study of three principal organisms--the nematode, fruitfly and mouse--indicate that cell suicide is implemented through the activation of an evolutionarily conserved molecular programme intrinsic to all metazoan cells. Dysfunctions in the regulation or execution of cell suicide are implicated in a wide range of developmental abnormalities and diseases.

One-year immunological evaluation of chronic hemodialysis in end-stage renal disease patients

BACKGROUND

Much research has been devoted to the determination of acute leukocyte activation as well as acute cytokines production during and after blood hemodialysis membrane interaction. In contrast, few studies deal with chronic immunological evaluation of T-cell activation markers in hemodialysis.

METHODS

We evaluated different immune parameters using a modified cellulose low-flux hemophan vs. synthetic high-flux polyamide membrane during 1 year in 35 stable chronic hemodialysis patients. Leukocyte counts, lymphocyte subpopulations, T-cell activation markers (CD69, CD25, HLA-DR, CD54, CD62L, CD45RO, CD11a, CD28), complement-activation products (C3a) and serum elastase were measured at 0, 3, 6 and 12 months in the two patient groups and compared to 13 healthy control subjects.

RESULTS

Over dialysis time, all patients showed a significant level elevation of CD69/CD3 (p < 0.005) and CD25/ CD3 (p < 0.005) phenotypes. In contrast, HLA-DR and CD45RO remained unchanged suggesting a truncated pattern of activation. T lymphocyte subset analysis showed in both hemodialyzed groups a significant decrease in the expression of CD54 (ICAM-1) when compared to controls (p < 0.005). C3a and elastase measurements showed a significant upward trend with dialysis time in both hemodialyzed groups.

CONCLUSION

Although the immunological changes seen in chronic hemodialyzed patients must be interpreted in conjunction with their basal uremic states and the membrane permeability properties, our study suggests that 1-year immunological evaluation of hemodialysis membranes biocompatibility is associated with changes in the pattern of chronic T-cell activation, which is in part related to the use of a particular membrane type. Moreover, some key molecules (CD54) are affected in patients with end-stage renal disease undergoing hemodialysis.

A finite-element model for the mechanical analysis of skeletal muscles

In the present paper, a finite-element model for simulating muscle mechanics is described. Based on nonlinear continuum mechanics an algorithm is proposed that includes the contractile active and passive properties of skeletal muscle. Stress in the muscle is assumed to result from the superposition of a passive and an active part. The passive properties are described by a hyperelastic constitutive material law whereas the active part depends on the fibre length, shortening velocity and an activation function. The constraint of approximate incompressibility of the muscle element is satisfied as a property of the constitutive equations. Because of the nonlinear behaviour of the material and the highly dynamical performance an incremental procedure including iterative methods is used. The advantage of the model over previous formulations is the possibility to integrate the element into an engineering standard finite-element programme ANSYS using advanced numerical tools. The model allows simulations of muscle recruitment, calculations of stress and strain distributions and predictions of muscle shape. Other possible applications are studies of the muscle architecture, the effect of inertia and impacts. First, simple examples are presented.

Cysteine 230 is essential for the structure and activity of the cytotoxic ligand TRAIL

Unlike other tumor necrosis factor family members, the cytotoxic ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/Apo-2L contains an unpaired cysteine residue (Cys(230)) in its receptor-binding domain. Here we show that the biological activity of both soluble recombinant TRAIL and cell-associated, full-length TRAIL is critically dependent on the presence of Cys(230). Mutation of Cys(230) to alanine or serine strongly affected its ability to kill target cells. Binding to its receptors was decreased by at least 200-fold, and the stability of its trimeric structure was reduced. In recombinant TRAIL, Cys(230) was found engaged either in interchain disulfide bridge formation, resulting in poorly active TRAIL, or in the chelation of one zinc atom per TRAIL trimer in the active, pro-apoptotic form of TRAIL.