Multiple sclerosis and cognitive decline: is ApoE-4 a surrogate marker?

BACKGROUND - The role of the apolipoprotein E (ApoE) polymorphism has been well demonstrated in neurodegenerative disorders such as Alzheimer. However, its role in multiple sclerosis (MS) remains unclear. AIMS - The aims of our study were as follows: (i) to assess whether ApoE-4 might be a surrogate marker of cognitive decline in MS; (ii) to confirm the presence of cognitive impairment in mildly disabled patients treated with interferon-beta; and (iii) to analyse the correlation between cognitive disturbances and clinical variables. MATERIAL AND METHODS -  Fifty relapsing-remitting MS patients underwent a battery of neuropsychological tests and were genotyped for ApoE. Their scores were compared with those of 35 controls. RESULTS - No association was found between ApoE-4 and cognitive impairment. Significant differences in most domains were observed between MS and the control group. Cognitive decline was not related to disability progression. CONCLUSION - No association between cognitive impairment and ApoE-4 or clinical markers was detected in our MS patients.

New strategies and patent therapeutics in EBV-associated diseases

Epstein-Barr virus (EBV) is a virus present all throughout the world that causes infectious mononucleosis (IM) and is highly associated with certain malignancies. This study is a review of current knowledge concerning the pathogenic mechanisms of EBV in tumor and auto-immune diseases and the different new strategies to treat EBV associated pathologies. Phenomena surrounding the proliferation and immortalization of B lymphocytes, the mechanisms of immune escape and the role of CD8+ and CD4+ T cells in the infection by EBV are explained. An analysis is made of the role of EBV proteins during the biological events that take place in primary infection, persistent chronic infection together with an update of the approaches of novel patented therapeutics. Currently there is no vaccine protecting against EBV-associated disorders and no treatment that may inhibit or eliminate their progression. Thus, it is crucial to obtain additional information on the function and importance of genes that play a role on the development of those diseases with which it is associated, as well as on the humoral and cellular immune processes involved in them.

Specificity of frontal dysfunctions in relapsing–remitting multiple sclerosis

Various studies have reported deficits in frontal cognitive functions in patients with multiple sclerosis (MS). However, the frontal deficit is not uniform and is often very subtle. The aim of this study was to assess frontal functions in a broad sample of patients with relapsing-remitting multiple sclerosis at the mild-to-moderate stage. The sample included a series of 165 patients. We used a test battery covering the frontal functions that have been described as being altered in MS. Significant differences were found between the patient group and healthy controls on the WAIS Arithmetic subtest, the PASAT, category word recall and the number of trials required to reach the first category of the WCST. In conclusion, we observed significant differences with respect to the control group in terms of information processing speed and working memory. These functions involve connections between the frontal lobe and other brain regions.

Effects of liraglutide (NN2211), a long-acting GLP-1 analogue, on glycaemic control and bodyweight in subjects with Type 2 diabetes

AIMS

Liraglutide (NN2211) is a long-acting GLP-1 analogue, with a pharmacokinetic profile suitable for once-daily administration. This multicentre, double-blind, parallel-group, double-dummy study explored the dose-response relationship of liraglutide effects on bodyweight and glycaemic control in subjects with Type 2 diabetes.

METHODS

Subjects (BMI 27-42 kg/m(2)) with Type 2 diabetes who were previously treated with an OAD (oral anti-diabetic drug) monotherapy (69% with metformin), and had HbA(1c) < or = 10% were enrolled. After a 4-week metformin run-in period, 210 subjects (27-73 years, 60% female) were randomised to receive liraglutide (0.045-0.75 mg) once daily or continued on metformin 1000 mg b.d. for 12 weeks.

RESULTS

Mean baseline values for the six treatment groups ranged from 6.8 to 7.5% for HbA(1c), and 8.06-9.44 mmol/l (145-170 mg/dl) for fasting plasma glucose. After 12-week treatment, a weight change of -0.05 to -1.9% was observed for the six treatment groups. Mean HbA(1c) changes from baseline for 0.045, 0.225, 0.45, 0.6, 0.75 mg liraglutide and metformin were +1.28%, +0.86%, +0.22%, +0.16%, +0.30% and +0.09%, respectively. No significant differences in HbA(1c) were observed between liraglutide and metformin groups at the three highest liraglutide dose levels (0.45, 0.6 and 0.75 mg). The lowest two liraglutide doses (0.045 mg and 0.225 mg) were not sufficient to maintain the fasting plasma glucose values achieved by metformin. No major hypoglycaemic episodes were reported. Episodes of nausea and/or vomiting were reported by 11 patients (6.3%) receiving liraglutide and three (8.8%) receiving metformin.

CONCLUSIONS

Once-daily liraglutide improved glycaemic control and weight, in a comparable degree to metformin. Liraglutide appeared to be safe and generally well tolerated. Higher doses of liraglutide merit study in future clinical trials.

Parenteral magnesium sulphate restores regional contractile function in the post-ischaemic canine myocardium

The effects of parenteral magnesium sulphate (MS) on the regional contractile response of stunned myocardium was examined in 45 pentobarbital anaesthetized dogs. The hearts were instrumented to measure left ventricular pressure (LVP), coronary flow velocity (CFV), mean arterial blood pressure (MAP), and regional contractile function (percent segment shortening, %S; and end-diastolic segment length, EDL). Stunning was produced by a 10 min occlusion of the first descending branch of the left circumflex coronary artery. Immediately upon release of the occlusion, either magnesium sulphate or a dextrose vehicle (D5W, n = 15) was infused. Magnesium sulphate was given intravenously (IV-MS, 100 mg/kg, n = 15) or intracoronarily (IC-MS, 1.5 mg/kg, n = 15). Coronary occlusion was consistently associated with significant decreases in coronary flow velocity and %S in all groups. Following IV-MS, heart rate (HR) and mean arterial blood pressure decreased significantly from preocclusion values, whereas end-diastolic segment length tended to increase and left ventricular pressure remained constant. IC-MS did not produce any changes in heart rate, mean arterial blood pressure, end- diastolic segment length or left ventricular pressure. At the end of the magnesium sulphate infusion (IV or IC), and for the next 60 min, %S returned to or above pre-occlusion values (P < 0.05 vs. D5W). Dyskinesia and hypokinesia were abolished in the magnesium sulphate groups, but were still present in the D5W group at the end of the 60 min period (P < 0.05 vs. pre-occlusion). We conclude that parenteral magnesium sulphate significantly improves regional contractile function in the stunned myocardium. Data from the IC-MS group would suggest a direct myocardial effect, independent of changes in preload, afterload, heart rate or flow.

Preliminary observations on the use of the Palmaz stent in the distal portion of the abdominal aorta

The opportunities to avoid surgical treatment of distal abdominal aortic occlusive disease are expanding because of the proliferation in catheter-based techniques. Since January 1990, 24 symptomatic patients with distal abdominal disorders have been treated percutaneously with balloon angioplasty and intraluminal stenting. A total of 38 Palmaz stents were deployed at distal abdominal aortic sites; 21 additional iliac stents were implanted. After the procedure all patients improved clinically, and 83% (21/24) improved by objective measurement (average ABI 0.93 +/- 0.21). Three access-related complications occurred (two hematomas, one thrombus), but no complications were related to the stents. At up to 29 months of follow-up (average 10.3 +/- 6.7 months), clinical improvement persists in all patients (average ABI 0.93 +/- 0.22). In 11 patients eligible for follow-up aortography, all aortic stents are patent without evidence of restenosis. With the low likelihood for restenosis in the abdominal aorta, the long-term outcome of aortic stenting looks promising and may equal or surpass that found in the iliac region.

Hemodynamics of heartworm infection

To determine the hemodynamic responsiveness of dogs testing positive for heartworms (direct blood smear), we compared the response of control and heartworm-infected animals to stellate stimulation (SS). Using the anesthetized, open-chest model, twenty dogs (10 control and 10 heartworm-positive) were instrumented to measure left ventricular pressure (LVP), arterial pressure (AP), and coronary flow velocity (CFV) of the left circumflex coronary artery. CFV was converted to flow per gram tissue (CBFG) by weighing the perfusion area of the circumflex artery. The average wet weight of the worm mass infecting the dogs was 1.0 +/- 0.1 g, which represented an average of 5% of the right ventricular free wall weight. Overall heart size and right ventricular weights were greater in the heartworm-positive animals, as well as heart weight to body weight ratios. Prior to SS, LVP was the same for both groups. However, dP/dt and CBFG were 21% and 19% lower, respectively, in the heartworm-positive animals. Stellate stimulation sufficient to produce a 30-mmHg rise in AP led to 25%, 13%, and 40% increases in LVP, dP/dt, and CBFG, respectively, in the control animals. Increases of 22%, 10%, and 52% in the same parameters were observed in the heartworm-positive animals. Although control dP/dt and CBFG in the heartworm-positive animals were lower than in the heartworm-negative animals, heartworm infection at this level did not hinder myocardial responsiveness to SS.

Angioscopy in endovascular surgery: recent technical advances to enhance intervention selection and failure analysis

Recent technical and procedural modifications have greatly enhanced the usefulness of angioscopy during angioplasty. A pulsed irrigation system, proximal and distal blood flow control by pressure, and attention to sheath/vessel diameter ratio were incorporated into a study in which angioscopy was used for pretreatment assessment in 23 patients with symptomatic peripheral vascular disease presenting for initial (8 patients) evaluation or repeat treatment (15 patients) following a previous vascular procedure. Twenty-five lesions were examined with a 2.3 mm flexible angioscope equipped with an irrigating lumen; there were no complications attributable to angioscopy. The angioscope was useful in the characterization of lesions for selection of the recanalization technique. Lesions more amenable to initial atherectomy were visualized in 12 patients; 7 occlusions were successfully treated with laser/balloon angioplasty, with angioscopy assisting in probe and/or wire passage in 4 cases. Three late reocclusions were identified angioscopically as due solely to thrombosis, indicating the need for thrombolytic therapy. Angioscopy also identified 4 cases of incomplete recanalization despite a satisfactory arteriographic image. Angioscopy was also used to evaluate stenotic lesions unaccompanied by thrombus formation in patients previously treated with laser-assisted angioplasty. Histologic evaluation of the biopsied plaques identified intimal hyperplasia as the etiology, matching identically similar specimens harvested from a lesion treated with balloon dilation only.

Laser-assisted angioplasty in the treatment of prosthetic graft stenosis

Late failure of peripheral bypass grafts has been treated primarily by secondary reconstruction. Laser-assisted angioplasty is an optional therapy that the authors investigated in 28 prosthetic grafts over a two-year period. Twenty-five symptomatic patients with 28 peripheral prosthetic arterial bypass grafts (25 polytetrafluoroethylene [PTFE] grafts and 1 each of knitted Dacron, Teflon, and umbilical vein) demonstrated graft occlusion (25) or high-grade stenoses (3). All patients underwent standard laser-assisted angioplasty using a continuous wave Nd:YAG laser source and hybrid probe. Twenty-one grafts (75%) were successfully recanalized with adequate restoration of flow through the conduit. All 7 failures were in occluded PTFE grafts that presented with either recalcitrant lesions (5) or perforations (2) at the distal anastomoses. There have been 3 long-term failures (14%) to date in the successfully treated group, all in PTFE grafts. Two patients suffered recurrent thrombosis and 1 developed an inexplicable graft infection five months after laser treatment. Laser-assisted angioplasty appears to be a clinically viable alternative treatment for prosthetic graft stenosis and recanalization of grafts occluded at their distal anastomosis.