Electrophysiological confirmation of the zona incerta as a target for surgical treatment of disabling involuntary arm movements in multiple sclerosis: use of local field potentials

Lesioning or chronic deep brain stimulation (DBS) of the nucleus ventralis intermedius results in abolition of tremor in the contralateral limbs in Parkinson's disease (PD) and also in essential tremor. Recently, chronic DBS of the subthalamic nucleus has also proved to be very effective in reducing contralateral limb tremor in PD. These targets have been less effective in controlling the complex limb tremor often seen in multiple sclerosis (MS). Consequently, other targets have been sought in cases of MS with tremor. We describe a patient with MS with disabling proximal and distal involuntary arm movements in whom we were able to obtain sustained control of contralateral arm tremor and achieve functional improvement of the affected arm by chronic DBS of the region of the zona incerta. We also highlight the important role played by local field potentials recorded from the brain, with simultaneous recording of corresponding EMGs, in target localisation.

Testing a structured decision approach: value-focused thinking for deliberative risk communication

Public participation is now part of many decision making processes for managing environmental and technical risks. This article describes a test of a strategy to improve the quality of public input by combining themes from risk communication with the prescriptive decision process of value-focused thinking. It was hypothesized that participating in a structured, value-focused risk communication approach would lead people to make more thoughtful, better informed, and hence higher quality decisions by helping them to consider and discuss a wider array of decision-relevant issues and address key value trade-offs. It is also anticipated that utilizing a value-focused decision structure would make participants feel more comfortable with their decisions; more satisfied that their selected alternative reflected their key concerns; and, in the end, more satisfied with their decisions. To test these hypotheses, six groups comprised of 7 to 10 people participated in conventional "alternative-focused" risk communication workshops and eight groups participated in similar "value-focused" workshops. All workshops dealt with the management of risks to riverine salmon habitat from hydroelectric electricity generation. The results provided support for the hypotheses: the value-focused decision structure led to more thoughtful and better informed risk management decisions.

Performance measurement for ambulatory care: moving towards a new agenda

Despite a shift in care delivery from inpatient to ambulatory care, performance measurement efforts for the different levels in ambulatory care settings such as individual physicians, individual clinics and physician organizations have not been widely instituted in the United States (U.S.). The Health Plan Employer Data and Information Set (HEDIS), the most widely used performance measurement set in the U.S., includes a number of measures that evaluate preventive and chronic care provided in ambulatory care facilities. While HEDIS has made important contributions to the tracking of ambulatory care quality, it is becoming increasingly apparent that the measurement set could be improved by providing quality of care information at the levels of greatest interest to consumers and purchasers of care, namely for individual physicians, clinics and physician organizations. This article focuses on the improvement opportunities for quality performance measurement systems in ambulatory care. Specific challenges to creating a sustainable performance measurement system at the level of physician organizations, such as defining the purpose of the system, the accountability logic, information and reporting needs and mechanisms for sustainable implementation, are discussed.

Comparative incidence of Type I diabetes in children aged under 15 years from South Asian and White or Other ethnic backgrounds in Leicestershire, UK, 1989 to 1998

AIMS/HYPOTHESIS

Estimates of incidence of Type I (insulin-dependent) diabetes mellitus in childhood populations vary around the world. This study aimed to estimate and compare the incidence of Type I diabetes in Leicestershire of children of South Asian and White or Other ethnic backgrounds.

METHODS

All new cases of childhood-onset Type I diabetes diagnosed before 15 years of age in Leicestershire during the period 1989-98 were studied. Population data for Leicestershire from the 1991 census was used. Ethnicity was assigned to all children in the study according to their surnames. Incidence rates (95%-Confidence limits) for the South Asian and white or other ethnic group were estimated and compared.

RESULTS

Over the 10-year period, 46 South Asian children and 263 children who were white or from another ethnic group fulfilled the criteria for inclusion in the study. Crude incidence rates per 100,000 person-years were 19.2 (12.0, 29.1) girls and 20.3 (13.0, 30.3) boys for South Asians and 17.7 (14.8, 21.1) girls and 17.7 (14.8, 20.9) boys for whites/others. Age and sex-specific rates were higher for South Asians over 5 years of age but differences were not statistically significant.

CONCLUSION/INTERPRETATION

Type I diabetes incidence rates for South Asian children in Leicestershire were very similar to those for children who were in the white/other ethnic group, in contrast to very low rates reported from Asia. The convergence of rates for South Asians with other ethnic groups in Leicestershire suggests that environmental factors are more important than genetic predisposition in causing Type I diabetes in people of South Asian ethnic background.

Bilateral internal globus pallidus stimulation for the treatment of spasmodic torticollis

Three patients with spasmodic torticollis (ST) obtained substantial benefit from bilateral globus pallidus internus (GPi) stimulation. Progressive improvement in ST occurred over several months but residual cervical dystonia remained. These results corroborate those obtained by Krauss et al. on three patients with ST.

Active repression and E2F inhibition by pRB are biochemically distinguishable

To understand mechanistically how pRB represses transcription, we used a reconstituted transcription assay and compared pRB activity on naked versus chromatin templates. Surprisingly, when pRB was directly recruited to a naked template, no transcriptional repression was observed. However, we observed active repression when the same promoter was assembled into chromatin. Histone deacetylases do not appear to play a role in this observed repression. Further experiments showed repression could occur after preinitiation complex assembly, in contrast with pRB inhibition of E2F, suggesting discrete mechanisms by which pRB directly inhibits an activator such as E2F or actively represses proximally bound transcription factors.

The effect of a venous anastomosis Tyrell vein collar on the primary patency of arteriovenous grafts in patients undergoing hemodialysis

PURPOSE

Vein collars and patches are used at the distal anastomoses of infrainguinal prosthetic grafts to improve graft patency. We initiated a randomized, prospective study to determine whether a Tyrell vein collar at the venous anastomosis of forearm loop arteriovenous grafts (AVGs) would improve patency.

METHODS

Patients who required new forearm AVGs were randomized to (1) a standard end-to-side graft-vein anastomosis (control group) or (2) a Tyrell vein collar between the graft and the vein (study group). End points were (1) graft thrombosis, (2) graft removal and ligation, or (3) inadequate graft function. Randomization of 75 subjects was planned. The study was terminated early for ethical reasons.

RESULTS

Seventeen patients (eight men, nine women) with a mean age of 52.8 years (range, 31-79 years) had 17 grafts placed (control group, n = 10; study group, n = 7). Comorbidities were not different between the groups (P>.05). Six (86%) of seven study grafts failed by 9 months (mean, 4.6 months). Four (66%) failed study grafts had venous outflow tract stenosis from intimal hyperplasia. This was confirmed at surgery in three and by angiography in one. The 9-month primary patency was 80% for the control group versus 17% for the study group (P =.015). Smaller outflow vein diameter in the study group (P =. 048) did not account for this inferior graft patency.

CONCLUSION

A Tyrell vein collar at the venous anastomosis of a forearm AVG resulted in premature graft failure. The use of a Tyrell vein collar may accelerate venous anastomosis intimal hyperplasia.

A case of isolated ACTH deficiency presenting with hypercalcaemia

A 76-year-old man presented with a subacute history of weight loss, malaise and anorexia. Laboratory investigations revealed serially increasing hypercalcaemia, correlating with deterioration in his clinical status. He was subsequently shown to have hypocortisolaemia, which improved with the administration of intravenous steroids. Subsequent biochemical testing revealed the endocrinological defect to be one of isolated ACTH deficiency, which, unlike Addison's disease, does not classically include hypercalcaemia in its presentation.

Acute isolated cerebral mucormycosis in a patient with high grade non-Hodgkins lymphoma

A 57-year-old female in complete remission of grade IV non-Hodgkin lymphoma whilst on intensive chemotherapy, suddenly developed unilateral hemispheric stroke with a fatal outcome in 3 days. She was apyrexial and had received antifungal prophylaxis during her treatment. Post-mortem examination showed complete thrombosis of the internal carotid artery leading to infarction in the territory of the middle and anterior cerebral arteries. Microscopic examination of the brain showed involvement of intra-cranial vessel walls and brain parenchyma by mucormyces, with no evidence of systemic mucormycosis. Isolated cerebral mucormycosis is a rare occurrence, more commonly found in intravenous drug abusers, but can occur in patients with haematological malignancy.

Anti-Gal antibodies in humans and 1, 3alpha-galactosyltransferase knock-out mice

BACKGROUND

Due to the absence of alphaGAL epitopes, humans and galactosyltransferase knock-out (GALT/ KO) mice express high levels of anti-Gal antibodies. We describe the properties of mouse anti-GAL antibodies.

METHODS

Anti-GAL IgG antibodies were quantified by affinity purification. Antibody affinities and avidities were determined in direct binding and competition assays. Antibody-mediated rejection was investigated using hyperimmunized GALT/KO mice as recipients of GAL+ heart allografts.

RESULTS

In young GALT/KO mice the levels of anti-GAL antibodies were low. Immunization of GALT/KO mice resulted in increased anti-GAL antibody expression. In mouse serum 0.6% of IgG was specific for alphaGAL compared to 0.5% in human serum. The avidity of purified mouse and human anti-GAL IgG was 30 and 6 nM, the affinity 15 and 50 microM, respectively. The isotype distribution in mouse and human anti-GAL IgG appeared to be similar to the isotype distribution in normal sera. The affinity of mouse and human anti-GAL IgM was 150 and 750 microM, respectively. Immunized GALT/KO recipients of GAL+ heart transplants rejected their grafts within 2 hr although nonimmunized GALT/KO mice retained their grafts for up to 6 days. Immunohistological examination of the rejected GAL+ hearts revealed massive deposition of IgM and IgG on endothelial cells of the graft with a concomitant deposition of complement.

CONCLUSIONS

Our studies demonstrate that anti-GAL antibodies from immunized GALT/KO mice bind alphaGAL with an avidity/affinity similar to human anti-GAL antibodies and are able to induce hyperacute rejection of GAL+ heart allografts.

Opening up extra dimensions at ultralarge scales

The standard picture of viable higher-dimensional theories is that direct manifestations of extra dimensions occur at short distances only, whereas long-distance physics is effectively four-dimensional. We show that this is not necessarily true in models with infinite extra dimensions. As an example, we consider a five-dimensional scenario with three 3-branes in which gravity is five dimensional at both short- and very long-distance scales, with conventional four-dimensional gravity operating at intermediate length scales. A phenomenologically acceptable range of validity of four-dimensional gravity extending from microscopic to cosmological scales is obtained without strong fine-tuning of parameters.

Nonsingular global string compactifications

We consider an exotic "compactification" of spacetime in which there are two infinite extra dimensions, using a global string instead of a domain wall. By having a negative cosmological constant we prove the existence of a nonsingular static solution using a dynamical systems argument. A nonsingular solution also exists in the absence of a cosmological constant with a time-dependent metric. We compare and contrast this solution with the Randall-Sundrum universe and the Cohen-Kaplan spacetime and consider the options of using such a model as a realistic resolution of the hierarchy problem.