Skin photoplethysmography--a review

The photoplethysmograph has been used for over 50 years but there are still misconceptions in how and what is the information obtained. A photoplethysmograph signal from any site on the skin can be separated into an oscillating (a.c.) and a steady-state (d.c.) component, their amplitudes dependent upon the structure and flow in the vascular bed. Many simple applications are available: pulse counters, using the a.c. component, skin colour and haemoglobin saturation meters, using the d.c. component. The d.c. component of the photoplethysmograph signal is a function of the blood flux beneath the device. A good emitter for use in a photoplethysmograph of skin blood flow is one in the frequency range 600-700 nm and the best signal for a.c. analysis is obtained from the finger pulp. The frequency range of the electronic circuitry should be from 0.01 to 15 Hz, then all the information in the signal can be extracted about the autonomic nervous system control of the cardiovascular system, particularly between 0.01 and 2 Hz. Comparative studies may be drawn between similar skin sites on a subject or between subjects if the afferent inputs to the brain stem are controlled or driven at a known frequency. These afferents, inputs, will modulate the efferents, outputs, which generate variations in the a.c. component of the detected photoplethysmograph signal.

Effects of docosahexaenoic acid-rich n-3 fatty acid supplementation on cytokine release from blood mononuclear leukocytes: the OmegAD study

BACKGROUND

Dietary fish or fish oil rich in n-3 fatty acids (n-3 FAs), eg, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), ameliorate inflammatory reactions by various mechanisms. Whereas most studies have explored the effects of predominantly EPA-based n-3 FAs preparations, few have addressed the effects of n-3 FAs preparations with DHA as the main FA.

OBJECTIVE

The objective was to determine the effects of 6 mo of dietary supplementation with an n-3 FAs preparation rich in DHA on release of cytokines and growth factors from peripheral blood mononuclear cells (PBMCs).

DESIGN

In a randomized, double-blind, placebo-controlled trial, 174 Alzheimer disease (AD) patients received daily either 1.7 g DHA and 0.6 g EPA (n-3 FAs group) or placebo for 6 mo. In the present study blood samples were obtained from the 23 first randomized patients, and PBMCs were isolated before and after 6 mo of treatment.

RESULTS

Plasma concentrations of DHA and EPA were significantly increased at 6 mo in the n-3 FAs group. This group also showed significant decreases of interleukin (IL)-6, IL-1beta, and granulocyte colony-stimulating factor secretion after stimulation of PBMCs with lipopolysaccharide. Changes in the DHA and EPA concentrations were negatively associated with changes in IL-1beta and IL-6 release for all subjects. Reductions of IL-1beta and IL-6 were also significantly correlated with each other. In contrast, this n-3 FA treatment for 6 mo did not decrease tumor necrosis factor-alpha, IotaL-8, IL-10, and granulocyte-macrophage colony-stimulating factor secretion.

CONCLUSION

AD patients treated with DHA-rich n-3 FAs supplementation increased their plasma concentrations of DHA (and EPA), which were associated with reduced release of IL-1beta, IL-6, and granulocyte colony-stimulating factor from PBMCs. This trial was registered at clinicaltrials.gov as NCT00211159.

Effects of DHA-rich n-3 fatty acid supplementation on gene expression in blood mononuclear leukocytes: the OmegAD study

BACKGROUND

Dietary fish oil, rich in n-3 fatty acids (n-3 FAs), e.g. docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), regulate inflammatory reactions by various mechanisms, e.g. gene activation. However, the effects of long-term treatment with DHA and EPA in humans, using genome wide techniques, are poorly described. Hence, our aim was to determine the effects of 6 mo of dietary supplementation with an n-3 FA preparation rich in DHA on global gene expression in peripheral blood mononuclear cells.

METHODS AND FINDINGS

In the present study, blood samples were obtained from a subgroup of 16 patients originating from the randomized double-blind, placebo-controlled OmegAD study, where 174 Alzheimer disease (AD) patients received daily either 1.7 g of DHA and 0.6 g EPA or placebo for 6 months. In blood samples obtained from 11 patients receiving n-3 FA and five placebo, expressions of approximately 8000 genes were assessed by gene array. Significant changes were confirmed by real-time PCR. At 6 months, the n-3 FAs group displayed significant rises of DHA and EPA plasma concentrations, as well as up- and down-regulation of nine and ten genes, respectively, was noticed. Many of these genes are involved in inflammation regulation and neurodegeneration, e.g. CD63, MAN2A1, CASP4, LOC399491, NAIP, and SORL1 and in ubiqutination processes, e.g. ANAPC5 and UBE2V1. Down-regulations of ANAPC5 and RHOB correlated to increases of plasma DHA and EPA levels.

CONCLUSIONS

We suggest that 6 months of dietary n-3 FA supplementation affected expression of genes that might influence inflammatory processes and could be of significance for AD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00211159.

Behaviour change, weight loss and remission of Type 2 diabetes: a community-based prospective cohort study

AIM

To quantify the association between behaviour change and weight loss after diagnosis of Type 2 diabetes, and the likelihood of remission of diabetes at 5-year follow-up.

METHOD

We conducted a prospective cohort study in 867 people with newly diagnosed diabetes aged 40-69 years from the ADDITION-Cambridge trial. Participants were identified via stepwise screening between 2002 and 2006, and underwent assessment of weight change, physical activity (EPAQ2 questionnaire), diet (plasma vitamin C and self-report), and alcohol consumption (self-report) at baseline and 1 year after diagnosis. Remission was examined at 5 years after diabetes diagnosis via HbA1c level. We constructed log binomial regression models to quantify the association between change in behaviour and weight over both the first year after diagnosis and the subsequent 1-5 years, as well as remission at 5-year follow-up.

RESULTS

Diabetes remission was achieved in 257 participants (30%) at 5-year follow-up. Compared with people who maintained the same weight, those who achieved ≥ 10% weight loss in the first year after diagnosis had a significantly higher likelihood of remission [risk ratio 1.77 (95% CI 1.32 to 2.38; p<0.01)]. In the subsequent 1-5 years, achieving ≥10% weight loss was also associated with remission [risk ratio 2.43 (95% CI 1.78 to 3.31); p<0.01].

CONCLUSION

In a population-based sample of adults with screen-detected Type 2 diabetes, weight loss of ≥10% early in the disease trajectory was associated with a doubling of the likelihood of remission at 5 years. This was achieved without intensive lifestyle interventions or extreme calorie restrictions. Greater attention should be paid to enabling people to achieve weight loss following diagnosis of Type 2 diabetes.

Patterns of cognitive asymmetry and syndromes of schizotypal personality

The Schizotypal Personality Questionnaire, modeled on the nine components of DSM-III-R schizotypy, was administered to 122 medical students along with the Thayer Activation-Deactivation Adjective Checklist and the Warrington Recognition Memory Test for words and faces. Close affinities were found between a three-factor schizotypal personality structure and a three-syndrome model of schizophrenia. Different patterns of cognitive asymmetry (word-face discrepancy scores) were related to Active and Withdrawn syndromes as in schizophrenia, and were related to high activation and general deactivation differences as predicted. A prospective single case study showed that a face-word discrepancy before a first episode of schizophrenia accurately predicted a Withdrawn presenting syndrome. The consistency between syndromes of schizophrenia and schizotypal personality in a normal population suggests possible etiological links between the two, and it supports a dimensional view of psychosis and subclinical predispositions.

Reduced prostaglandin F2 alpha release from blood mononuclear leukocytes after oral supplementation of omega3 fatty acids: the OmegAD study

Omega-3 fatty acids, e.g., dokosahexaenoic acid (DHA) and eikosapentaenoic acid (EPA), ameliorate inflammatory reactions by various mechanisms, but the role of prostaglandins remains unclear. Our aim was to determine if dietary supplementation with a DHA-rich fish oil influenced the release of PGF(2alpha) from peripheral blood mononuclear cells (PBMC). In the OmegAD study, 174 Alzheimer disease patients received either 1.7 g DHA plus 0.6 g EPA or a placebo daily for six months. PBMCs from the 21 (9 on fish oil and 12 on placebo) first-randomized patients were stimulated with either lipopolysaccharide (LPS) or phytohemagglutinin (PHA) before and after 6 months. Our results showed that plasma concentrations of DHA and EPA increased significantly at 6 months in the omega-3 group. PGF(2alpha) release from LPS- (but not from PHA-) stimulated PBMC was significantly diminished in this group; no change was noted in the placebo group. PGF(2alpha) changes correlated inversely with changes in plasma DHA and EPA. Decreased IL-6 and IL-1(beta) levels correlated with decreased PGF(2alpha) levels. The stimulus-specific PGF(2alpha) release from PBMC after 6 months of oral supplementation with the DHA-rich fish oil might be one event related to reduced inflammatory reactions associated with omega-3 fatty acid intake.

Prevalence and Risk of Protein-Energy Wasting Assessed by Subjective Global Assessment in Older Adults With Advanced Chronic Kidney Disease: Results From the EQUAL Study

OBJECTIVES

Prevalence and risk factors for protein-energy wasting (PEW) are poorly studied in the nondialysis, older population with advanced chronic kidney disease (CKD). Our aim was to evaluate the prevalence of PEW in advanced stage CKD patients aged greater than 65 years. Furthermore, we aimed to describe risk factors for PEW in the overall study population and among obese individuals.

DESIGN

Prospective observational cohort study.

METHODS

The EQUAL study, a European Quality Study on treatment in advanced chronic kidney disease, is a multicenter prospective observational cohort study in six European countries. We included patients aged ≥65 years with incident glomerular filtration rate <20mL/min/1.73m² not on dialysis attending nephrology care. PEW was assessed by 7-point Subjective Global Assessment (7-p SGA).

RESULTS

In general, the study cohort (n = 1,334) was overweight (mean body mass index [BMI] 28.4 kg/m²). The majority of the patients had a normal nutritional status (SGA 6-7), 26% had moderate PEW (SGA 3-5), and less than 1% had severe PEW (SGA 1-2). Muscle wasting and loss of fat tissue were the most frequent alterations according to the SGA subscales, especially in those aged >80 years. The prevalence of PEW was higher among women, increased with age, and was higher in those with depression/dementia. PEW was the most common in those with underweight (BMI <22 kg/m²), 55% or normal weight (BMI 22-25 kg/m²), 40%. In obese individuals (BMI >30 kg/m²), 25% were diagnosed with protein wasting. Risk factors for SGA ≤5 in obese people were similar to those for the overall study population.

CONCLUSION

This European multicenter study shows that the prevalence of PEW is high in patients with advanced CKD aged >65 years. The risk of PEW increases substantially with age and is commonly characterized by muscle wasting. Our study suggests that focus on nutrition should start early in the follow-up of older adults with CKD.

DHA-rich n-3 fatty acid supplementation decreases DNA methylation in blood leukocytes: the OmegAD study

Background: Dietary fish oils, rich in long-chain n-3 (ω-3) fatty acids (FAs) [e.g., docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3)], modulate inflammatory reactions through various mechanisms, including gene expression, which is measured as messenger RNA concentration. However, the effects of long-term treatment of humans with DHA and EPA on various epigenetic factors-such as DNA methylation, which controls messenger RNA generation-are poorly described.Objective: We wanted to determine the effects of 6 mo of dietary supplementation with an n-3 FA preparation rich in DHA on global DNA methylation of peripheral blood leukocytes (PBLs) and the relation to plasma EPA and DHA concentrations in Alzheimer disease (AD) patients.Design: In the present study, DNA methylation in four 5'-cytosine-phosphate-guanine-3' (CpG) sites of long interspersed nuclear element-1 repetitive sequences was assessed in a group of 63 patients (30 given the n-3 FA preparation and 33 given placebo) as an estimation of the global DNA methylation in blood cells. Patients originated from the randomized, double-blind, placebo-controlled OmegAD study, in which 174 AD patients received either 1.7 g DHA and 0.6 g EPA (the n-3 FA group) or placebo daily for 6 mo.Results: At 6 mo, the n-3 FA group displayed marked increases in DHA and EPA plasma concentrations (2.6- and 3.5-fold), as well as decreased methylation in 2 out of 4 CpG sites (P < 0.05 for all), respectively. This hypomethylation in CpG2 and CpG4 sites showed a reverse correlation to changes in plasma EPA concentration (r = -0.25, P = 0.045; and r = -0.26, P = 0.041, respectively), but not to changes in plasma DHA concentration, and were not related to apolipoprotein E-4 allele frequency.Conclusion: Supplementation with n-3 FA for 6 mo was associated with global DNA hypomethylation in PBLs. Our data may be of importance in measuring various effects of marine oils, including gene expression, in patients with AD and in other patients taking n-3 FA supplements. This trial was registered at clinicaltrials.gov as NCT00211159.

Psychological factors associated with recurrent vaginal candidiasis: a preliminary study

OBJECTIVE

To identify psychological factors associated with chronic recurrent vaginal candidiasis.

DESIGN

A cross sectional exploratory study of women with chronic, recurrent vaginal candidiasis.

PATIENTS

28 women found culture positive and treated for vaginal candidiasis by a clinic physician at least twice within the past 6 months. All women reported that they had experienced vaginal thrush six or more times within 1 year. A comparison group comprised 16 women with no history of recurrent vaginal candidiasis, of similar age range, and recruited from a women's family planning service.

METHODS

Both groups were compared on demographic criteria, sexual health histories, mental health, and psychological health characteristics. A purpose designed structured interview was administered alongside a battery of standardised psychometric instruments measuring mood, satisfaction with life, self esteem, and perceived stress.

RESULTS

The two groups showed considerable similarities, with no significant differences in demographic characteristics and most sexual health issues. However, women with recurrent vaginal candidiasis were significantly more likely to suffer clinical depression, to be less satisfied with life, to have poorer self esteem, and to perceive their lives as more stressful. Additionally, women with recurrent vaginal candidiasis reported that their candidiasis seriously interfered with their sexual and emotional relationships.

CONCLUSIONS

Overall, this study identified many areas of psychological morbidity associated with chronic vaginal candidiasis, and indicates that development of appropriate psychological treatment initiatives in this area is long overdue.

Progesterone concentration in the peripheral plasma of pregnant goats

Plasma progesterone concentration was measured by a competitive protein-binding method in serial samples of jugular venous blood from 21 pregnant goats, 11 with twin and 10 with single foetuses.

Progesterone levels in twin pregnancies were significantly greater than in singletons. The mean progesterone concentration (ng/ml plasma) in the twin pregnancies was greatest during the 3rd month of gestation (10·7 ± 0·4 (s.e.m.)) and in the singletons during the 4th month (7·8 ± 0·2 (s.e.m.)). There was a significant decrease in mean progesterone concentration in the last month of pregnancy due to a steady decline in the last 7 days before parturition.

The mean progesterone concentrations at parturition in five twin and eight single pregnancies were 2·2 ± 0·4 and 1·5 ± 0·2 (s.e.m.) ng/ml plasma respectively; there was no significant difference between these values. In cord blood from nine kids immediately after delivery the progesterone concentration was 0·9 ± 0·1 ng/ml.

Prospective associations between lateralised brain function and immune status in HIV infection: analysis of EEG, cognition and mood over 30 months

Prospective relations between individual differences in both lateralised neuro-psychophysiological functions and mood ratings with immune status (CD4 and CD8 counts) were examined in asymptomatic HIV-positive men (n = 27) over thirty months. They participated in a controlled study of zidovudine versus placebo (results published elsewhere). Measures included EEG spectra, neuropsychological tests and mood ratings. A model of reciprocal lateralised influences on the immune system was tested whereby patients with left superior to right hemispheric functions were predicted to show a less deleterious outcome than those with the opposite asymmetry pattern. Prospective relations with immune status were found in the EEG with lateralised theta, alpha and beta activity; among cognitive measures with word fluency, semantic processing, and lateralised motor and recognition memory (word/face) processes; with mood ratings including depression, confusion and the total mood score. The nature of the effects supported the laterality predictions. These unique data, showing that neuro-psychophysiological factors in HIV+ but otherwise healthy subjects predict immune competence and compromise present 2-3 years later, warrant replication in a larger cohort.

Psychological distress among gay men supporting a lover or partner with AIDS: a pilot study

To date, there has been little research to examine how much psychological distress is caused to people providing care and support to a lover or partner with AIDS. This study aimed to determine the level of psychological distress experienced by a sample of gay men providing care and support to a lover or partner with AIDS. It was conducted as a cross-sectional questionnaire survey. A control group was not enlisted, thus the study was descriptive in nature. The experimental hypothesis proposed that providing care and support would result in a high level of psychological distress. Thirty-eight gay men, some of whom themselves were infected with HIV, who were the primary carer of a lover or partner with an AIDS diagnosis were assessed using a self-report questionnaire. The 28-item General Health Questionnaire was used as a measure of global psychological distress. In addition, Martin's (1988) Traumatic Stress Response Scale was used as a measure of psychological distress arising specifically from AIDS. The sample reported high levels of global and AIDS-specific psychological distress. The levels of distress reported were of such a degree to indicate that the majority of the sample were probably suffering from significant psychiatric problems. The results strongly suggest that providing care and support to a lover or partner with AIDS may have an adverse affect on the carer's own psychological health: however, because of the design of the study it is impossible to state this conclusively.

A national study examining the effect of making emergency hormonal contraception available without prescription

BACKGROUND

In January 2001, emergency hormonal contraception was made available for women over the age of 16 years directly from a pharmacist without prescription. It is of interest whether this change in the UK has led to any improvements or deterioration in the service provided for the women who need it.

METHODS

Self- completed, anonymous questionnaires were distributed to women requesting emergency hormonal contraception through a single group of pharmacies located throughout England, Wales and Scotland.

RESULTS

A total 419 women returned completed questionnaires. A greater proportion of women were able to take emergency contraception within 24 h when they obtained their tablets directly from a pharmacy without a prescription (64% versus 46%, P = 0.029). Women who obtained their drugs directly from the pharmacist were just as well informed, just as likely to arrange regular follow-up and generally preferred this system, although they disliked having to pay.

CONCLUSION

Making emergency hormonal contraception available without prescription has improved services to women who need them, but these improvements are quantitatively minimal, preventing only five additional pregnancies per 10,000 users.

Auditory and visual event-related potentials in a controlled investigation of HIV infection

Auditory and visual event-related brain potentials (ERPs) were used to complement neuropsychological and medical assessment in neurologically healthy subjects with asymptomatic and symptomatic human immunodeficiency virus type 1 (HIV-1) infection. Auditory and visual ERPs, recorded using standard oddball paradigms, disclosed delays in late waves (N2 and P3) in symptomatic subjects (CDC stage IV) when compared with matched controls. Abnormally delayed P3 waves in at least one modality were recorded in 41% of symptomatics and this was associated with deficits in neuropsychological performance, particularly psychomotor slowing. However, no differences in late wave latencies between asymptomatic and control subjects were found, though asymptomatics showed delays in auditory N1 and P2 latencies. The number of morphological abnormalities, such as indiscernible late waves as well as topographical variability of the P3 wave, was increased in both HIV seropositive groups and possibly indicates a distinct mechanism of impairment, different from latency delay. Whilst P3 delay in symptomatics was not associated with changes in immune function (T4 cells) there was, however, a link with anaemia and subclinical hepatic dysfunction.

Nutritional and cognitive status in elderly subjects living in service flats, and the effect of nutrition education on personnel

BACKGROUND

There is limited knowledge about the nutritional and cognitive status in elderly and chronically ill subjects living in sheltered housing.

OBJECTIVE

To perform a 6-month follow-up study in order to investigate (1) nutritional status and its relationship to cognitive function in elderly people living in service flats, and (2) the effect of a 9-hour educational program given to personnel working in the service flats.

METHODS

Of 93 eligible subjects, 28 agreed to participate (age 81 +/- 7 years, 75% women). Body mass index (BMI), triceps skin fold (TSF), arm muscle circumference (AMC), appetite, Subjective Global Assessment (SGA), serum albumin, serum insulin-like growth factor-1 (IGF-1) and Mini Mental Test (MMT) were assessed on two occasions with a 6-month interval. The staff of the service flats answered a questionnaire before and 6 months after an educational program.

RESULTS

At the start, BMI, TSF and AMC were within the normal ranges, e.g. BMI 26.6 +/- 3.1 for men and 25.6 +/- 3.2 for women. Three subjects were suspected to be malnourished and 2 were malnourished according to SGA. Among 20 randomly selected subjects who chose not to participate in the investigation, age, sex, BMI, weight loss and appetite were not significantly different from those values in participants. However, none of the latter had a BMI <20 compared to 10% in non-participants. The MMT results suggested cognitive dysfunction in 41% of the subjects. On the first test occasion, MMT correlated with BMI (r = 0.43, p < 0.03), weight loss (r = 0.4, p < 0.05) and age (r = -0.38, p < 0.05). The ability of the personnel to suggest suitable nutrition for fictitious patient cases appeared to have improved after the educational program. At the 6-month follow-up, the BMI in men rose to 27.0 +/- 3.4 (p < 0. 05), while other anthropometric measurements remained unchanged. Serum IGF-1 lay within the normal range, as did serum albumin which, however, rose from 39.1 +/- 2.9 to 41.2 +/- 3.5 g/l (p < 0.01).

CONCLUSION

Fifteen to twenty percent of the individuals studied in the service flats displayed definite or possible signs of malnutrition. Cognitive function correlated with BMI, weight loss and age. The educational program appeared to increase the nutritional knowledge in personnel working in the service flats. At the 6-month follow-up, the nutritional status of the residents had not deteriorated.

Comparative safety and tolerability of duloxetine vs. pregabalin vs. duloxetine plus gabapentin in patients with diabetic peripheral neuropathic pain

OBJECTIVE

The safety and tolerability of three treatments for diabetic peripheral neuropathic pain (DPNP) were compared.

METHODS

A 12-week, randomized, open-label study confirming the non-inferiority of duloxetine (N = 138) vs. pregabalin (N = 134) and the combination of duloxetine plus gabapentin (N = 135) as the primary outcome was previously published. Patients had an inadequate pain response to a stable dose of gabapentin (≥ 900 mg/day) for ≥ 5 weeks prior to study enrolment. Data from that study were assessed in this current analysis for a detailed report of safety and tolerability.

RESULTS

Completion rates did not differ significantly between the groups. Discontinuation because of adverse events was significantly greater in the duloxetine (19.6%) vs. pregabalin group (10.4%; p = 0.04); no differences emerged between the duloxetine vs. duloxetine plus gabapentin (13.3%) groups (p = 0.19) or pregabalin vs. duloxetine plus gabapentin groups (p = 0.57). Adverse event rates varied: nausea, insomnia, hyperhidrosis and decreased appetite were reported significantly more often in patients treated with duloxetine vs. patients treated with pregabalin (each p ≤ 0.01); insomnia significantly more in patients treated with duloxetine vs. duloxetine plus gabapentin (p = 0.01); peripheral oedema significantly more in patients treated with pregabalin vs. duloxetine and duloxetine plus gabapentin (p ≤ 0.001 each) and nausea, hyperhidrosis, decreased appetite and vomiting significantly more in patients treated with duloxetine plus gabapentin vs. pregabalin (each p ≤ 0.05). At end-point, weight change differed significantly among treatment groups: patients in the pregabalin group on average gained weight (1.0 ± 0.04 kg); while, patients in the duloxetine and duloxetine plus gabapentin groups on average lost weight (-2.39 ± 0.04 and -1.06 ± 0.04 kg, respectively) (pregabalin vs. duloxetine, p ≤ 0.001; pregabalin vs. duloxetine plus gabapentin, p ≤ 0.001; duloxetine vs. duloxetine plus gabapentin, p = 0.01).

CONCLUSION

Duloxetine, pregabalin and duloxetine plus gabapentin were generally safe and tolerable for the treatment of DPNP.

Neurophysiological evaluation of zidovudine in asymptomatic HIV-1 infection: a longitudinal placebo-controlled study

The effect of early antiretroviral medication with zidovudine on neurophysiological functions was evaluated in subjects with asymptomatic HIV-1 infection. Patients were recruited participants of a larger double-blind randomised placebo-controlled treatment trial with zidovudine (Concorde). The main outcome measures included: quantitative electroencephalography (QEEG), auditory event-related potentials (AEP) and pattern-reversal visual evoked potentials (PRVEP), as well as standard clinical, virological and immunological markers. No significant impairment and no difference between treatment groups was found in visual P100 latency and auditory long-latency P3 responses which is in agreement with the absence of neurological and neuropsychological impairment over the study period. Significant treatment effects were revealed by quantitative electroencephalography (QEEG). While the placebo group showed a significant increase in delta and theta slow frequency QEEG activity over the study period, slow wave amplitude remained unchanged in the zidovudine group after a mean follow-up period of 28 months. In summary, the data provide evidence for a low level neuropathological process in asymptomatic HIV-1 infection which can be effectively suppressed by antiretroviral medication.

Painless electrodiagnostic current perception threshold and pain tolerance threshold values in CRPS subjects and healthy controls: a multicenter study

The purpose of this study is to evaluate both painless and painful sensory transmission in patients with Complex Regional Pain Syndrome (CRPS) using the automated electrodiagnostic sensory Nerve Conduction Threshold (sNCT) test. This test generates reliable, painless Current Perception Threshold (CPT) and atraumatic Pain Tolerance Threshold (PTT) measures. Standardized CPT and PTT measures using constant alternating current sinusoid waveform stimulus at 3 different frequencies 5 Hz, 250 Hz, and 2 kHz (Neurometer CPT/C Neurotron, Inc. Baltimore, MD) were obtained from CRPS subjects at a distal phalange of the affected extremity and at an ipsilateral asymptomatic control site. Matched sites were tested on healthy subjects. Detection sensitivities for an abnormal PTT and CPT test were calculated based on specificity of 90% as determined from data obtained from healthy controls. A Spearman rank correlation was used to test for a significant association between presence of allodynia and an abnormal PTT or CPT at any frequency tested. Thirty-six CRPS subjects and 57 healthy controls were tested. The highest detection sensitivity of the PTT test from symptomatic test sites was 63% for the finger and 71% for the toe. PTT abnormalities were also detected, to a lesser degree, at the asymptomatic control site (41% finger control site, 16% toe control site). The highest CPT detection sensitivity at the symptomatic site was 37% for the finger site and 53% for the toe site. CPT abnormalities were also detected at the asymptomatic control site (29% finger control site, 37% toe control site). Eighty-six percent of the CRPS subjects had either a PTT or CPT abnormality at any frequency at the symptomatic site. There was a significant correlation between presence of allodynia and presence of an abnormal CPT and PTT, respectively (P < .01). The correlation coefficient was lower for CPT than for PTT, ie, 0.34 versus 0.6 for the finger and 0.48 versus 0.67 for the toe, respectively. In studied CRPS patients an abnormal PTT was detected with higher sensitivity than an abnormal CPT. Assessing PTT may become a useful electrodiagnostic quantitative sensory test for diagnosing and following the course of neuropathic pain conditions.

Chronic heart failure guidelines: do they adequately address patient need at the end-of-life?

INTRODUCTION

A number of international guidelines have been developed to support primary care clinicians improve the quality of care for patients with chronic heart failure at the end of life. The objective of this study was to undertake a systematic evaluation of such guidelines in relation to end-of-life care.

METHODS

A systematic literature search of research databases and guideline clearing houses was undertaken. The selected guidelines were independently assessed by two researchers using the AGREE II quality criteria. A data-extraction framework was devised based on the holistic needs assessment tool of the Gold Standards Framework. The content of each guideline was then analysed using an approach similar to that used for thematic analysis.

RESULTS

A total of 19 guidelines were included. Those guidelines with lower overall AGREE II scores covered fewer domains on the holistic needs assessment. Across all guidelines the lowest scoring domain was applicability and stakeholder involvement. Qualitative assessment showed that some guidelines adopt an unwavering disease orientated approach to assessing patient need. Guidance around continuity of care, out of hours care and after care was particularly poor in several guidelines. There was considerable heterogeneity in the evidence presented even amongst those guidelines that achieved high AGREE II scores.

CONCLUSION

Combined quantitative and qualitative assessment demonstrates the importance of rigorous guideline development. Whilst the variation in evidence presented could be a result of methodological heterogeneity in the development of guidelines, it raises important questions about the processes by which evidence, information and knowledge become transformed into clinical guidelines.

Beta-adrenergic blockade restores glucose's antiketogenic activity after exercise in carbohydrate-depleted athletes

1. The development of post-exercise ketosis is not abolished by the ingestion of glucose immediately after exercise, despite inducing high insulin/glucagon ratios in the peripheral (and therefore by implication in the portal) blood. 2. To investigate the possibility of autonomic control of the liver influencing its sensitivity to the major counter-regulatory hormones, we administered 50 g glucose, either on its own, or together with 0.5 mg prazosine, 40 mg propranolol, or 15 mg propantheline, to forty-seven 48 h carbohydrate-starved athletes who had just run 25 km. 3. The blood 3-hydroxybutyrate concentration rose from 0.30 +/- 0.05 (mean +/- S.E. of mean) to 0.52 +/- 0.08 mmol/l with exercise, and then to 1.32 +/- 0.40 mmol/l at 6 h after exercise in subjects who had ingested only glucose after exercise. 4. The effects of prazosine and propantheline on the blood ketone body concentration at 2 h after exercise was not statistically significant. Propranolol, on the other hand, significantly lowered the blood 3-hydroxybutyrate concentration (compared with controls) to 0.09 +/- 0.03 mmol/l at 3 h (P less than 0.01), and 0.35 +/- 0.08 mmol/l at 6 h (P less than 0.01) after exercise. 5. The plasma insulin, glucagon, glucose and free fatty acid concentrations were unaffected by propranolol, indicating that the antiketogenesis was the result of a direct effect on ketone body metabolism. 6. Since beta-adrenergic blockade has not previously been shown to have antiketogenic activity, except in somatostatin-induced hyperketonaemia, it is concluded that its effectiveness in post-exercise ketosis can probably be ascribed to a functional hepatic insulin and glucagon deficiency.

Quantitative assessment of differential sensory blockade after lumbar epidural lidocaine

A cutaneous current perception threshold (CPT) sensory testing device measures both large and small diameter sensory nerve fiber function and may be useful in evaluating differential neural blockade. Eight subjects received both lumbar epidural saline and lumbar epidural lidocaine. Five milliliters of normal saline was administered and the CPTs were measured. After the saline, 10 mL of 2% plain lidocaine was administered. CPTs, and sensation to touch, pinprick, and cold were subsequently measured. Saline had no effect on any measurements. Lidocaine caused an increase in all CPTs at the umbilicus and the knee reaching a statistical significance at 5 Hz for the umbilicus only. The great toe showed a slight increase of the 5 Hz stimulus and no increase of the 2000 or 250 Hz stimulus. There was a significant decrease in touch, pinprick, and cold sensation at the umbilicus and knee and a significant decrease in the cold sensation at the great toe. There was no effect on any measurements made at the mastoid. Epidural lidocaine resulted in a differential neural blockade as measured by a CPT monitor but not with crude sensory measurements.

Methods for objectively assessing clinical masticatory performance: protocol for a systematic review

BACKGROUND

Chewing and masticatory function constitutes one of the most important oral health factors that affect quality of life, especially in older individuals. Little consensus currently exists regarding ways to objectively assess clinical masticatory performance (in this context, performance refers an individual's objective ability to mix or comminute food bolus). That said, many methods were developed to assess masticatory performance. Consequently, systematic review of the literature would be of great value when it comes to identifying various methods for objectively assessing clinical masticatory performance and for evaluating these methods.

DESIGN

This study protocol describes a systematic review that intends to (i) identify methods to objectively assess clinical masticatory performance and (ii) evaluate psychometric properties (such as validity and reliability) of the identified methods. A systematic literature search is required to do so in these sources: MEDLINE (Ovid), Embase (embase.com), Web of Science Core Collection (Thomson Reuters), Cochrane (Wiley), and Cinahl (Ebsco).

INCLUSION CRITERIA

studies in scientific, full-text articles; development articles; validation articles; studies of the general adult population, ages ≥18.

EXCLUSION CRITERIA

topics and article types that cover interview methods and self-reported questionnaires; methods/instruments that measure subjective masticatory performance; qualitative studies and case studies; opinion and editorial pieces; animal studies; studies of humans with severe oral health complications.

DISCUSSION

This systematic review will result in a comprehensive assessment of various methods designed to objectively measure clinical masticatory performance. This systematic review will rate these methods, assess their reliability and validity, and identify one or more methods that can be recommended for use in clinical and scientific environments. From what is currently known, no systematic evaluation of various methods for objectively assessing clinical masticatory performance has been published.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016037700.

The reliability and validity of a symptom checklist for use in HIV infection: a preliminary analysis

The aim of the study was to determine the reliability and validity of a self-report symptom checklist designed for use in HIV infection. One hundred and seventy-one gay men completed a 28-item symptom checklist which produces 3 dimensions: physical, cognitive and psychological. The validity of each dimension was examined by comparing scores on the checklist with indices of disease progression and previously validated psychological scales. People with more advanced HIV disease had higher scores on the physical and cognitive checklists, though the psychological scale was not related to disease stage. All the scales showed moderate correlations with measures of psychological health. Examination of individual item responses suggested that patients over-reported the presence of some symptoms. Although individual items should be interpreted with caution, the overall scores of the RSC are reliable and valid as measures of subjective health status in HIV infection. The importance of psychological factors in the reporting of symptoms suggests that symptom checklists should be interpreted in the light of adequate measures of psychological state.

To eat or not to eat: dietary fat in uremia is the question

Although a diet low in protein is well known to reduce the risk of progression in patients with chronic kidney disease (CKD), the impact of dietary fat content and fat quality has largely been ignored. As a reduced protein intake results in an obligatory reduction in energy intake, and as CKD patients often suffer from energy malnutrition, this issue deserves greater attention. The present review aims to summarize what is currently known about dietary fat intake in CKD and suggests areas for further study. We conclude that although overweight per se is an important risk factor for the development of CKD, the role of obesity as a risk factor for complications in manifest CKD remains unclear. Current data support a balanced increase in dietary fat intake in patients with CKD to compensate for reduced energy intake in protein-restricted diets and anorexic patients. However, patients who are obese should be encouraged to lose weight while maintaining or, preferably, increasing muscle mass.