Effect of memantine on CBF and CMRO2 in patients with early Parkinson's disease

OBJECTIVES

Parkinson's disease (PD) may be associated with increased energy metabolism in overactive regions of the basal ganglia. Therefore, we hypothesized that treatment with the N-methyl-d-aspartate receptor (NMDAR) antagonist memantine would decrease regional cerebral blood flow (rCBF) and oxygen metabolism in the basal ganglia of patients with early-stage PD.

METHODS

Quantitative positron emission tomography (PET) recordings were obtained with 15O]water and 15O]oxygen in 10 patients, scanned first in a baseline condition, and again 6 weeks after treatment with a daily dose of 20 mg memantine. Dynamic PET data were analyzed using volume of interest and voxel-based approaches.

RESULTS

The treatment evoked rCBF decreases in basal ganglia, and in several frontal cortical areas. The regional cerebral metabolic rate of oxygen (rCMRO2) did not decrease in any of the a priori defined regions, and consequently the oxygen extraction fraction was increased in these regions. Two peaks of significantly decreased rCMRO2 were detected near the frontal poles in both hemispheres, using a posteriori voxel-based analysis.

CONCLUSIONS

Although we did not find the predicted decrease in basal ganglia oxygen consumption, our data suggest that treatment with memantine actively modulates neuronal activity and/or hemodynamic response in basal ganglia of PD patients. This finding may be relevant to the putative neuroprotective properties of NMDAR antagonists.

Role of molecular shape on bent-core liquid-crystal structures

We show how frustrations in molecular packing generated by molecular substitutions and electrostatic potentials necessitate a local C1 symmetry and lead to spontaneous polarization splay and layer bending in bent-core liquid crystals. By estimation of the entropic changes due to curvature, we calculated the elastic constants that drive the spontaneous layer bend and polarization splay and obtained length scales of these deformations. Finally, we propose a structural phase diagram which describes how the experimentally observed helical superstructures, layer undulation, polarization splay, and spontaneous fiber formation depend on the direction and magnitude of the spontaneous polarization.

Structure and stability of bent core liquid crystal fibers

Recently it was found that fluid smectic phases of bent core liquid crystals formed freestanding fibers of extremely high slenderness ratios. Studies of these fibers showed that their structure was composed of concentric cylindrical smectic layers. For this configuration to be stable there must be an energy term that desires bending of the smectic layers. We show that an energy term that deals with the divergence of the dipolar direction can encourage layer bending if the layer chirality value is allowed to vary. The energy term associated with holding the layer chirality is closely related to layer compressions and electrical self-interactions. For our model, we assumed a simple smectic-C geometry with constant molecular tilt and cone angle defined by the director with respect to the layer normal, but allowed a constant variation of the polar direction about the director. Applying this simplified model to a free energy which accounts for director distortions, divergence of the polar direction, biaxial layer strain, surface tension, and electrical self-interactions, we were able to show consistency between the stable fiber radius and other properties predicted in our model to results from experimental studies.

The new 4DDome prosthesis: an original light and partially absorbable composite mesh for hernia repair

INTRODUCTION

The use of non-absorbable meshes for the repair of inguinal hernias has become standard; however, these meshes have been associated with complications including long-term postoperative pain. To this end, a new partially absorbable composite mesh has been developed, and the aim of this study was to investigate its efficacy in animal and human trials.

MATERIALS AND METHODS

Sixty male Wistar rats were used to evaluate the behavior of the newly designed composite mesh. Composite meshes were implanted in the extra-peritoneal plane for 2, 4 and 8 weeks and compared to a standard polypropylene mesh. Forty patients with symptomatic inguinal hernias were treated using a new 4DDome designed prosthesis. Follow-up was by clinical and ultrasound examination at 1, 6 and 12 months.

RESULTS

The animal study demonstrated that the inflammatory reaction associated with the new composite mesh was significantly lower than a standard polypropylene mesh, characterized by a lower macrophage infiltrate (P < 0.001). The mesh did not shrink over the 8-week period, unlike the polypropylene mesh (P < 0.05). The human study showed that there were three minor postoperative complications, no recurrences and the mesh was well tolerated. Follow-up with serial ultrasound showed that at 10 days and 1 month the dome was clearly visible in position; however, by 6 months it had flattened out, been partially absorbed and become incorporated into the repair.

CONCLUSION

These experimental and clinical studies have validated the concept of the new 4DDome composite mesh. It was well tolerated and was associated with good short-term results. The combination of the dome shape and the new composite mesh means that less polypropylene is required and represents a significant advance in anterior hernia repair.

Reported symptoms and quality-of-life impacts in patients having laser treatment for sight-threatening diabetic retinopathy

AIMS

To explore the patient experience of symptoms of eye disease related to diabetes and its treatment, including increase of symptoms over time and their relation to severity of the condition and the effect of multiple treatments and symptoms on quality of life.

METHODS

A qualitative interview study was implemented at four eye clinics in the UK. This study design was intended to yield 240 interviews in patients having their first laser treatment or first follow-up and in multi-treatment patients with a clinically documented loss of visual function in at least one eye (VA </= 6/12). The intention was to have an approximately equal number of patients with proliferative diabetic retinopathy (PDR) or macular oedema (MO).

RESULTS

A total of 227 interviews were completed (54% PDR and 46% MO). The most frequently reported symptom prior to initial treatment was blurred vision (55%). First-time-treatment patients reported fewer symptoms than the multi-treatment patients. After a pronounced reduction of quality-of-life impacts after the first laser treatment, results all demonstrate an increasing impact as patients move from first treatment to multiple treatments. The main responses regarding satisfaction with laser treatment were that, although patient expectations were basically met, the treatment had less of an impact than they hoped for, and they would have the treatment again if needed.

CONCLUSIONS

The current study provides a qualitative exploration of visual symptoms, levels of self-reported visual impairment, and general description of the areas of impact or restriction that patients experienced due to their eye disease, both pre- and post-laser treatment.

Older patients' experiences of treatment for colorectal cancer: an analysis of functional status and service use

Age and ageing are an important part of the context within which the care and treatment of people with cancer is provided. More information is needed about the effects of cancer treatment on the lives of older people following inpatient care. We conducted a 3-year study in which older people with colorectal cancer completed a detailed questionnaire on multidimensional function and service use before and after elective treatment. Here we present an analysis of changes in functional status and service use over the pre- to post-treatment period, and set out a detailed picture of older people's experiences before and after treatment. In total, 337 patients with colorectal adenocarcinoma aged 58-95 years were interviewed before treatment using the OARS Multidimensional Functional Assessment Questionnaire (OMFAQ), Rotterdam Symptom Checklist (RSCL) and a severity of morbidity score. Study end points were defined as post-treatment functional status, symptom distress, severity of morbidity and frequency of service use. Pre- and post-treatment data were compared using matched analyses. Logistic regression was used to assess associations between age and the main outcome measures, and frequency of service use after treatment was compared between age groups using the chi2 test. Overall, patients experienced both positive and negative outcomes following treatment. It was notable that patients aged > or = 75 years showed improvement in only one of the principal outcome measures. Patterns of service use following treatment suggest that support at home is a key issue for patients. With the exception of nursing care, however, help at home is provided on a majority of occasions by families themselves. This raises important questions about how much preparation patients and families receive or would like before they leave hospital after treatment for cancer. A collaborative, family-centred approach to meeting people's needs is called for in the months following inpatient care.

Serious lead poisoning in childhood: still a problem after a century

OBJECTIVE

To describe a series of patients with clinically significant lead poisoning.

METHODOLOGY

A case series of nine patients with lead poisoning who required inpatient management, identified through a Clinical Toxicology Service.

RESULTS

Nine children presented with clinically significant lead poisoning. The median serum lead was 2.5 micro mol/L (range 1.38-4.83). Eight of the children were exposed to lead-based paint, with seven due to dust from sanded lead paint during house renovations. Serial blood determinations suggested re-exposure in four of the patients, and in one of these patients the re-exposure was from a different source of lead. Eight of the patients required chelation therapy.

CONCLUSIONS

Serious lead poisoning continues to occur and there appears to be complacency regarding the hazard posed by lead paint in old houses.

Treatment decisions in older patients with colorectal cancer: the role of age and multidimensional function

The aim of the study was to investigate the role of age and multidimensional functional status in treatment decisions in older patients with colorectal cancer. Three hundred and thirty-seven patients aged 58-95 years with adenocarcinoma of the colon or rectum were interviewed before and after treatment using the OARS Multidimensional Functional Assessment Questionnaire (OMFAQ), a self-reported severity of morbidity scale, and the Rotterdam Symptom Checklist (RSCL). The OMFAQ rates five dimensions of function: social resources, economic resources, mental and physical health and self-care capacity. The likelihood of patients with Duke's C colorectal cancer receiving adjuvant chemotherapy decreased significantly with age (P = 0.001, trend). Differences in treatment received were not explained by differences in morbidity, economic, mental or physical function, self-care capacity, or any of the RSCL measures. After controlling for age, Duke's C patients who received adjuvant chemotherapy were less impaired in social resources than Duke's C patients who did not (P = 0.06). No other significant pre-treatment differences in functional status were found. Differences in age and social resources exist between patients who do and do not receive adjuvant chemotherapy. Care should be taken to ensure that patients are not excluded from treatment with known survival benefits because of their age, and the question of providing appropriate social support during adjuvant chemotherapy should be re-examined.

'Fit for purpose' health impact assessment: a realistic way forward

The UK government is committed to health impact assessment (HIA) as a means of ensuring that health will be a key consideration in policy formulation and other public decision making. However there has been some debate about whether current HIA practice can reliably inform decision making. In particular consultation with stakeholders and literature reviewing, key tools used in HIA, are said to suffer from a number of conceptual and methodological problems, which can undermine the validity of the assessment. In this paper, we argue that the philosophical nature of HIA, its purpose and its contribution to the promotion of public health is still being established. We outline our own HIA practice, which is based on a broad philosophy of 'fit for purpose' i.e. what is this HIA for and what is its spatial, temporal, social and political context. We suggest that it is important to guard against unrealistic expectations and illusions of total objectivity and precision in the HIA process. HIA 'screening' is capable of delivering benefits by making policies, programmes and projects, more health conscious. Once we move beyond this basic expectation and wish to be able to make judgements about the relative health benefits of alternative courses of action, the potential resource intensiveness of the process increases considerably. Even at a high level of resource usage any conclusions reached through the HIA process will always be, in part, subjective and therefore likely to be contested. We must decide what we want, what we are prepared to legislate for and what we are prepared to pay for in the HIA process.

Care and the older person with cancer

Care of older people with cancer has received relatively little attention in the literature and this area of caring practice has yet to be firmly established in professional discourse. References to the increasing proportion of older people in the population are common, as are references to the problems associated with old age, whether these are seen as medical, or as inevitable consequences of natural processes. Health care for older people has sometimes been reported to be routinized or basic, and as taking little account of individual perspectives, and the 'discourse of senescence' represents a tendency to understand old age and the aged body in terms of degeneration and deterioration. Here, it is argued that older people are often portrayed as separate and diminished, and have little control over the definition of themselves as users of health services. This represents a constraint upon the possibilities of caring practice. Divesting ourselves of the 'discourse of senescence' may be a fundamental part of developing caring practice for older people with cancer in the future.

A dose-comparison trial of topiramate as monotherapy in recently diagnosed partial epilepsy

OBJECTIVE

To evaluate topiramate as monotherapy in adults and children with recently diagnosed, localization-related epilepsy, comparing two dosages of topiramate in a multicenter, randomized, double-blind study.

METHODS

Adults and children (>/=3 years of age) were eligible if the maximum interval since epilepsy diagnosis was 3 years and patients had one to six partial-onset seizures during a 3-month retrospective baseline. At study entry, patients (N = 252) were untreated or receiving one antiepileptic drug for less than 1 month. After randomization to 50 or 500 mg/d topiramate (25 or 200 mg/d if weight </= 50 kg), patients remained in the study until 4 months after the last patient was randomized or until patients met seizure-related exit criteria (e.g., had two seizures). The primary efficacy outcome was a univariate analysis of time-to-exit, which was time to second seizure in 96% of patients.

RESULTS

The time-to-exit (median, 422 days vs 293 days) favored the higher dose of topiramate, but this difference was not significant. When time-to-exit was analyzed with time-to-first-seizure as a covariate, the difference between dosage groups was significant (p = 0.01), reflecting the higher seizure-free rates (54% vs 39%, p = 0.02) and longer time-to-first-seizure (median 317 days vs 108 days; p = 0.06) in patients receiving 200 or 500 mg/d topiramate. Higher plasma concentration was associated with increased time-to-first seizure (p < 0.01). Dose-related adverse events included paresthesia, weight loss, diarrhea, and hypoesthesia.

CONCLUSIONS

Although the primary efficacy analysis was negative, time-to-exit analyses that included time-to-first-seizure as a covariate, between-group differences in seizure-free rates, and longer time-to-first-seizure with higher serum concentration provide evidence that topiramate is effective as monotherapy in patients with localization-related epilepsy.

Effects of metformin on bile salt transport by monolayers of human intestinal Caco-2 cells

The antidiabetic biguanide metformin has been shown to increase faecal excretion of bile salts in type 2 diabetes. Cultured human intestinal Caco-2 cell monolayers provide a model of human enterocytes. These monolayers are used here to determine the effect of metformin on the secondary-active, sodium-linked transfer of 14C-glycocholate from the apical (brush border) to the basolateral (serosal) surface. During 24-h incubations, 10-2 mol/l metformin significantly reduced 14C-glycocholate transfer. This could not be attributed to alterations of monolayer integrity or Na+-K+ ATPase pump activity. For example, the secondary-active transport of glucose and proline was not interrupted, and the inhibitory effect of metformin on bile salt transport was additive to the inhibitory effect of ouabain. The results suggest that metformin can act directly on intestinal enterocytes to reduce the active transfer of bile salts by a mechanism that is independent of Na+-K+ ATPase activity.

Cochlear implants in children with craniofacial syndromes: assessment and outcomes

The aim of this retrospective study was to review the outcomes for children with craniofacial syndromes who had received a cochlear implant. The group comprised four children (three girls, one boy) aged between 3.3 and 10.1 years (mean 6.3 years) at time of implantation with the Cochlear CI-22M device. Two children had the CHARGE association. one had Goldenhar's syndrome and one had brachio-oculo-facial syndrome. All had full electrode insertion at time of surgery. At follow-up, three of the children demonstrated benefit in detection, recognition and identification of environmental sounds, and they continued to gain receptive spoken language skills, although none had intelligible speech. The group required careful mapping and higher levels of electrical stimulation of the implant compared to normal child implantees. Stimulation of the facial nerve was a problem with one child. The pre-implantation assessment of these children requires extensive interdisciplinary discussion and careful radiological investigation. Cases should be carefully selected. Parents should receive realistic counselling about outcomes and the time commitment necessary, as habilitation of these children can take twice as long as that of children without additional special needs. Post-implantation, these children continue to require well-coordinated medical and interdisciplinary management.

A novel, recombinant triple antigen hepatitis B vaccine (Hepacare)

Infection with hepatitis B virus (HBV) continues to be a major problem in the human population. There remains a specific requirement for HBV vaccines capable of circumventing the non-responder/inadequate responder status of some vaccinees. Hepacare has been primarily developed to (1) improve anti-SHBs antibody titres in low responders, to conventional SHBsAg vaccinees, (2) overcome difficulties of non-compliance seen with existing SHBsAg vaccine regimens. Hepacare is a novel recombinant particle produced in eukaryotic cells, consisting of pre-S1, pre-S2 and S proteins of HBV and is adjuvanted with alhydrogel. It has been demonstrated to be highly immunogenic for both B and T cells in mice, chimpanzees and humans and induces higher anti-S 'a' determinant antibody titres than SHBsAg vaccines in mice and humans. Hepacare has proven to be at least as efficacious as current SHBsAg vaccines in chimpanzees. Clinical trials in both Europe and the USA have clearly demonstrated its superior ability to induce anti-SHBs antibody seroconversion in low-responder groups, compared with SHBsAg vaccines.