Current distribution under electrodes in relation to stimulation current and skin blood flow: are modern electrodes really providing the current distribution during stimulation we believe they are?

Carbonized rubber electrodes were tested extensively when they were first developed 30 years ago, but modern carbonized rubber electrodes have not received the type of scrutiny that the first electrodes received. Modern electrodes differ from the original electrodes in that they come with a self-adhesive electrode gel called hydrogel as part of their composition. The present study was undertaken to examine the current distribution and impedance characteristics of five brands of carbonized rubber electrodes and to examine the current distribution between electrodes during electrical stimulation in six subjects. Several different electrode sizes were tested between 3 and 10 cm. The current flow between the electrodes was determined by measuring the voltage across the skin on human subjects in 15 discrete locations between the electrodes. Blood flow was also measured between the electrodes with a laser Doppler flow meter to assess the physiological effect of current distribution on the skin at several skin temperatures. The results of these studies showed that at low currents, such as is used in TENS, very little current is actually applied through the skin due to the high impedance of the electrodes. At current levels normally used for electrical stimulation for functional movement, while current flow is better in most electrodes, it is very uneven, resulting in high current density in the centre of the electrodes and a fall off of at least 50% in current intensity at the edges of the electrode. There was very little difference in current density between small and large electrodes due to the high current density in the centre. Skin blood flow altered the movement of current between the electrodes and also may contribute to electrode performance. The implication of these studies is that electrode design needs to be altered for better current distribution, especially at low stimulation currents.

Voodoo dolls and the cancer patient: patients do trust their doctors

OBJECTIVES

To determine oncology patients' pattern and rationale of complementary and alternative medicine (CAM) use, and canvass their views on the relative merits of allopathic and alternative medicine.

DESIGN

Observational study of opinions from a cohort of patients using self-completion questionnaires.

SETTING

Oncology departments of two UK teaching hospitals.

PARTICIPANTS

Voluntary participation of 200 oncology patients attending clinic.

MAIN FINDINGS

Twenty-two percent of patients used CAM, with a preponderance towards younger, female patients. The commonest reasons for CAM use is to make the patient feel better and to help with their cancer. However, patients seldom believe there is more evidence for CAM or that CAM will cure them, indeed often noticing no benefits from the treatment. CAM users do not resort to complementary medicine due to dissatisfaction with their doctor but instead have considerable trust in their physicians. Only a minority believes their doctor knows about their CAM use.

CONCLUSION

CAM use by oncology patients in the UK is less common than that reported elsewhere. Although patients try CAM in the hope that it will help with their treatment, they are realistic about its likely benefits. It uptake is not as an indication of lack of faith in doctors, yet physicians are frequently unaware of use. Therefore, the medical profession should not feel threatened by patients resorting to CAM but instead focus on understanding the reasons behind it.

Disseminated Penicilium marneffei infection

This is a case report of disseminated Penicillium marneffei infection in a patient with leprosy, responding to antifungal therapy. Radiologically there were nodules in the left lung, right pleural effusion, lymphadenopathy in neck, mediastinum and upper abdomen and abscesses in the liver and right parietal lobe. This case highlights a rare infection in a non-HIV related immunocompromised patient, and its nonspecific radiologic manifestations.

The prediction of coronary atherosclerosis employing artificial neural networks

BACKGROUND

Atherosclerosis is a complex histopathologic process that is analogous to chronic inflammatory conditions. Several factors have been shown to correlate with the extent of atherosclerosis. Whereas hypertension, obesity, hyperlipidemia, diabetes, smoking, and family history are all well documented, recent literature points to additional associated factors. Thus, antibodies to oxidized low-density lipoprotein (oxLDL), cytomegalovirus (CMV), Chlamydia pneumonia, Helicobacter pylori, as well as homocysteine and C-reactive protein (CRP) levels have all been implicated as independent markers of accelerated atherosclerosis.

HYPOTHESIS

In the current study we attempted to formulate a system by which to predict the extent of coronary atherosclerosis as assessed by angiographic vessel occlusion.

METHODS

The 81 patients were categorized as having single-, double-, triple-, or no vessel involvement. The clinical data concerning the "classic" risk factors were obtained from clinical records, and sera were drawn from the patients for determination of the various parameters that are thought to be associated with atherosclerosis.

RESULTS

Using four artificial neural networks, we have found the most effective parameters predictive of coronary vessel involvement were (in decreasing order of importance) antibodies to oxLDL, to cardiolipin, to CMV, to Chlamydia pneumonia, and to beta 2-glycoprotein I (beta 2GPI). Although important in the prediction of vessel occlusion, hyperlipidemia, hypertension, CRP levels, and diabetes were less accurate.

CONCLUSION

The results of the current study, if reproduced in a larger population, may establish an integrated system based on the creation of artificial neural networks by which to predict the extent of atherosclerosis in a given subject fairly and noninvasively.

Neuroglycopenia and adrenergic responses to hypoglycaemia: insights from a local epidemic of serendipitous massive overdose of glibenclamide

AIMS

Recently, an unlicensed aphrodisiac formulation originating from China known as 'Power 1 Walnut' penetrated the illicit markets of South East Asia including Singapore. Subsequent toxicological analyses revealed that each 'Power 1 Walnut' pill was illegally adulterated with two prescription drugs--sildenafil 1 mg (a PDE5 inhibitor) and glibenclamide 93-98 mg (a long-acting sulphonylurea). As the drug was peddled to numerous people, a local 'hypoglycaemia epidemic' ensued, of which a small cluster presented to our hospital with severe hypoglycaemia. The aim is to characterize the demographics, clinical and labouratory aspects and postulate mechanisms for the relatively atypical presentation.

METHODS

A retrospective study of all the patients admitted between 13th January to 15th June 2008 with hypoglycaemia was done with acquisition of all relevant data after ethical approval from our DSRB.

RESULTS

15 patients (25-73 years old) presented with severe hypoglycaemia. All of them presented with neuroglycopenic symptoms (5-confusion, 6-drowsiness to loss of consciousness, 4-seizures and 1-coma) 12-36 h after ingestion of 'Power 1 Walnut'. Liquid chromatography-mass spectrometry (LC/MS) confirmed the presence of glibenclamide in the urine. None experienced a full-blown hypoglycaemia-associated autonomic response defined as sweating, sensation of warmth, anxiety, tremor, nausea, palpitations, tachycardia, and hunger. Only 4/16 patients had symptoms of a partial autonomic response, and 3/16 patients had tachycardia and/or hypertension.

CONCLUSIONS

The above suggests an inappropriate autonomic and catecholamine response to severe hypoglycaemia in these cases of serendipitous glibenclamide overdose. Possible reasons for the blunted autonomic responses and apparent autonomic failure are reviewed.

Clinical significance of precore and core promoter mutations in genotype D hepatitis B-related chronic liver disease

The impact of mutations in the precore and basal core promoter (BCP) regions of the hepatitis B virus on the course of chronic liver disease is not well established. We sought to examine the relationship of these characteristics to the clinical expression of liver disease in patients infected with genotype D chronic hepatitis B (CHB). BCP and precore mutations in 110 patients with genotype D1 CHB were determined and correlated with clinical phenotype. Of 110 patients, 95 (86.5%) were HBeAg-negative. Compared with HBeAg-positive subjects, HBeAg-negative patients were over a decade older and had lower viral loads (3.70 +/- 0.98 vs 5.77 +/- 0.69 log copies/ml, P < 0.001). The double mutation A1762T-G1764A was more prevalent in patients with advanced liver disease (AdLD) and was associated with higher alanine aminotransferase and viral load. After adjusting for age, there was a more than fourfold increase in the risk of AdLD with this mutation (OR = 4.4; 95% CI: 1.13-16.92, P < 0.03). Conversely, the G1757A substitution was associated with protection, being 90% less frequent among patients with AdLD (P = 0.001). The results indicate that in genotype D CHB, the presence of the A1762T-G1764A mutation was associated with more aggressive liver disease while the G1757A substitution was associated with protection from advanced disease.

Tubercular synovitis mimicking rheumatoid nodules

Tubercular tenosynovitis is an uncommon condition and usually affects the upper limb. We report a case of a patient with Systemic Lupus Erythematosus who presented with wrist swelling. The clinical findings were suggestive of rheumatoid nodules, but the radiographic finding of calcification associated with the nodules and marked erosive changes primarily of the radio-carpal joint with sparing of the metacarpal joints led the radiologist to believe that the nodules may not be rheumatoid nodules. The presence of solid and fluid nature of the nodule and hyperechoic small echogenic foci (matted rice bodies within thickened synovium) on ultrasound suggested the presence of chronic synovitis of tuberculous infection rather than rheumatoid nodule as in our case. We recommend the use of ultrasound to determine the nature of nodular swellings seen clinically in patients with arthropathy.

Spironolactone for poorly controlled hypertension in type 2 diabetes: conflicting effects on blood pressure, endothelial function, glycaemic control and hormonal profiles

AIMS/HYPOTHESIS

Aldosterone antagonism improves endothelial function (and reduces deaths) in chronic heart failure. It is not known whether similar effects occur in other high-risk groups such as patients with diabetes and hypertension. We therefore assessed the full effects of aldosterone blockade in poorly controlled hypertensive patients with type 2 diabetes, focussing on blood pressure, endothelial function, glycaemic control and key hormones.

METHODS

We performed a randomised, placebo-controlled, double-blind, crossover study on 50 patients with type 2 diabetes and treated but poorly controlled hypertension, comparing spironolactone versus placebo. Patients had their endothelial function assessed by standard forearm venous occlusion plethysmography.

RESULTS

There was no significant improvement in endothelium-dependent vasodilatation in response to acetylcholine, despite highly significant reductions in systolic and diastolic blood pressure. However, spironolactone significantly worsened glycaemic control, plasma angiotensin II and cortisol.

CONCLUSIONS/INTERPRETATION

Spironolactone is highly effective in lowering blood pressure in patients with type 2 diabetes and poorly controlled hypertension on standard treatment, but does not improve vascular endothelial function in this group. We speculate that any tendency for the spironolactone-induced lowering of blood pressure to improve endothelial function is offset by its tendency to worsen glycaemic control and increase the levels of angiotensin II and even possibly cortisol.

Elevated serum β-glucuronidase reflects hepatic lysosomal fragility following toxic liver injury in rats

The level of serum β-glucuronidase increases in various pathological conditions, including liver disorders. The aim of this investigation was to study the changes in liver lysosomal membrane stability during experimentally induced hepatic fibrosis that may result in the elevation of serum β-glucuronidase. Liver injury was induced by intraperitoneal injections of N-nitrosodimethylamine (NDMA) in adult male albino rats over 3 weeks. The progression of fibrosis was evaluated histopathologically as well as by monitoring liver collagen content. Lipid peroxides and β-glucuronidase levels were measured in the liver homogenate and subcellular fractions on days 0, 7, 14, and 21 after the start of NDMA administration. Serum β-glucuronidase levels were also determined. A significant increase was observed in β-glucuronidase levels in the serum, liver homogenate, and subcellular fractions, but not in the nuclear fraction on days 7, 14, and 21 after the start of NDMA administration. Lipid peroxides also increased in the liver homogenate and the lysosomal fraction. The measurement of lysosomal membrane stability revealed a maximum lysosomal fragility on day 21 during NDMA-induced fibrosis. In vitro studies showed that NDMA has no significant effect on liver lysosomal membrane permeability. The results of this investigation demonstrated that lysosomal fragility increases during NDMA-induced hepatic fibrosis, which could be attributed to increased lipid peroxidation of lysosomal membrane. In this study, we also elucidated the mechanism of increased β-glucuronidase and other lysosomal glycohydrolases in the serum during hepatic fibrosis.

Bcl-2 siRNA augments taxol mediated apoptotic death in human glioblastoma U138MG and U251MG cells

The anti-neoplastic drug taxol binds to beta-tubulin to prevent tumor cell division, promoting cell death. However, high dose taxol treatment may induce cell death in normal cells too. The anti-apoptotic molecule Bcl-2 is upregulated in many cancer cells to protect them from apoptosis. In the current study, we knocked down Bcl-2 expression using cognate siRNA during low-dose taxol treatment to induce apoptosis in two human glioblastoma U138MG and U251MG cell lines. The cells were treated with either 100 nM taxol or 100 nM Bcl-2 siRNA or both for 72 h. Immunofluorescent stainings for calpain and active caspase-3 showed increases in expression and co-localization of these proteases in apoptotic cells. Fluorometric assays demonstrated increases in intracellular free [Ca(2+)], calpain, and caspase-3 indicating augmentation of apoptosis. Western blotting demonstrated dramatic increases in the levels of Bax, Bak, tBid, active caspases, DNA fragmentation factor-40 (DFF40), cleaved fragments of lamin, fodrin, and poly(ADP-ribose) polymerase (PARP) during apoptosis. The events related to apoptosis were prominent more in combination therapy than in either treatment alone. Our current study demonstrated that Bcl-2 siRNA significantly augmented taxol mediated apoptosis in different human glioblastoma cells through induction of calpain and caspase proteolytic activities. Thus, combination of taxol and Bcl-2 siRNA offers a novel therapeutic strategy for controlling the malignant growth of human glioblastoma cells.