High-fidelity encoding of mechanostimuli by tactile food-sensing neurons requires an ensemble of ion channels

The nematode C. elegans uses mechanosensitive neurons to detect bacteria, which are food for worms. These neurons release dopamine to suppress foraging and promote dwelling. Through a screen of genes highly expressed in dopaminergic food-sensing neurons, we identify a K2P-family potassium channel-TWK-2-that damps their activity. Strikingly, loss of TWK-2 restores mechanosensation to neurons lacking the NOMPC-like channel transient receptor potential 4 (TRP-4), which was thought to be the primary mechanoreceptor for tactile food sensing. The alternate mechanoreceptor mechanism uncovered by TWK-2 mutation requires three Deg/ENaC channel subunits: ASIC-1, DEL-3, and UNC-8. Analysis of cell-physiological responses to mechanostimuli indicates that TRP and Deg/ENaC channels work together to set the range of analog encoding of stimulus intensity and to improve signal-to-noise characteristics and temporal fidelity of food-sensing neurons. We conclude that a specialized mechanosensory modality-tactile food sensing-emerges from coordination of distinct force-sensing mechanisms housed in one type of sensory neuron.

High-flow nasal cannula versus non-invasive ventilation for acute hypercapnic respiratory failure in adults: a systematic review and meta-analysis of randomized trials

Background

Non-invasive ventilation (NIV) with bi-level positive pressure ventilation is a first-line intervention for selected patients with acute hypercapnic respiratory failure. Compared to conventional oxygen therapy, NIV may reduce endotracheal intubation, death, and intensive care unit length of stay (LOS), but its use is often limited by patient tolerance and treatment failure. High-flow nasal cannula (HFNC) is a potential alternative treatment in this patient population and may be better tolerated.

Research question

For patients presenting with acute hypercapnic respiratory failure, is HFNC an effective alternative to NIV in reducing the need for intubation?

Methods

We searched EMBASE, MEDLINE, and the Cochrane library from database inception through to October 2021 for randomized clinical trials (RCT) of adults with acute hypercapnic respiratory failure assigned to receive HFNC or NIV. The Cochrane risk-of-bias tool for randomized trials was used to assess risk of bias. We calculated pooled relative risks (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with corresponding 95% confidence intervals (CI) using a random-effects model.

Results

We included eight RCTs (n = 528) in the final analysis. The use of HFNC compared to NIV did not reduce the risk of our primary outcome of mortality (RR 0.86, 95% CI 0.48–1.56, low certainty), or our secondary outcomes including endotracheal intubation (RR 0.80, 95% CI 0.46–1.39, low certainty), or hospital LOS (MD − 0.82 days, 95% CI − 1.83–0.20, high certainty). There was no difference in change in partial pressure of carbon dioxide between groups (MD − 1.87 mmHg, 95% CI − 5.34–1.60, moderate certainty).

Interpretation

The current body of evidence is limited in determining whether HFNC may be either superior, inferior, or equivalent to NIV for patients with acute hypercapnic respiratory failure given imprecision and study heterogeneity. Further studies are needed to better understand the effect of HFNC on this population.

Parameters of Spinal Cord Stimulation in Complex Regional Pain Syndrome: Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Complex Regional Pain Syndrome (CRPS) is a chronic debilitating neuropathic pain condition characterized by autonomic and inflammatory features that typically occurs after a traumatic event. Spinal cord stimulation (SCS) has been shown to be effective in the treatment of chronic CRPS refractory to conventional treatment modalities. The collective evidence of novel parameters of SCS for treating CRPS has not been characterized extensively.

OBJECTIVE

To provide evidence for the use of SCS to treat CRPS and characterize the additional benefits of various SCS waveforms.

STUDY DESIGN

Systematic Review and Meta-analysis.

METHODS

PubMed, Embase and CINHLA were screened for all randomized controlled trials (RCT) comparing SCS parameters for the treatment of CRPS.

RESULTS

Four RCTs were identified that included SCS as a treatment arm for CRPS. Of these, one study compared low frequency tonic SCS (LF-SCS) versus conventional physical therapy, 2 studies compared placebo/sham SCS with LF-SCS and a multitude of waveforms, and one study compared LF-SCS with high-frequency SCS (HF-SCS). Two of the studies were rated as having a low risk of bias, one study was rated as having some concerns for bias, while the final study was rated as having a high risk of bias. A meta-analysis of 4 studies comparing conventional therapy/placebo SCS stimulation against LF-SCS revealed increased benefit of LF-SCS in pain reduction up to a month (mean difference [MD] = -1.17 points; 95% CI = -1.61 to -0.73; P < 0.001, I2 = 42%). Another meta-analysis of 2 studies showed that LF-SCS results in higher global perceived effect scores relative to conventional therapy/placebo SCS stimulation (MD = 1.58; 95% CI = 1.00 to 2.15; P < 0.001, I2 = 0%).

LIMITATIONS

A pooled analysis using different designs for RCTs was conducted. Some studies folded in multiple neuropathic pain pathologies in addition to CRPS. One study was at a high risk for bias in at least one domain.

CONCLUSION

LF-SCS is superior to conventional therapy/placebo SCS stimulation. However, more evidence is required to demonstrate that novel SCS parameters are superior to LF-SCS in improving pain scores and functional outcomes.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Effect of Diet, Exercise, or Both on Biological Age and Healthy Aging in Older Adults with Obesity: Secondary Analysis of a Randomized Controlled Trial

OBJECTIVES

To determine the effect of diet, exercise, and diet-exercise in combination on measures of biological age.

DESIGN

Secondary analysis of a 1-year randomized, controlled trial.

SETTING

University-based Medical Center.

PARTICIPANTS

One-hundred-seven older (age≥65 yrs.) adults with obesity (BMI≥30 kg/m2) were randomized and 93 completed the study. Analyses used intention-to-treat.

INTERVENTIONS

Participants were randomized to a control group, a weight-management (diet) group, an exercise group, or a weight-management-plus-exercise (diet-exercise) group.

MAIN OUTCOME MEASURES

We calculated Klemera-Doubal Method (KDM) biological age, Homeostatic Dysregulation (HD) score, and Health Aging Index (HAI) score at baseline, and changes at 6- and 12-months.

RESULTS

Diet and diet-exercise decreased KDM biological age more than exercise and control (-2.4±0.4, -2.2±0.3, -0.2±0.4, and 0.2±0.5, respectively, P<0.05 for the between group-differences). Diet and diet-exercise also decreased HD score more than exercise and control (-1.0±0.3, -1.1±0.3, 0.1±0.3, and 0.3±0.3 respectively, P<0.05). Moreover, diet-exercise decreased HAI score more than exercise, diet, or control (-1.1±0.2, -0.5±0.2, -0.5±0.2, and 0.0±0.2, respectively, P<0.05).

CONCLUSIONS

These findings suggest that diet and diet-exercise are both effective methods of improving biological age, and that biological age may be a valuable method of assessing geroprotective interventions in older humans.

P1500Effects of empagliflozin on cardiac function in patients with type 2 diabetes mellitus: echocardiographic substudy of the EMPA-HEART cardiolink-6 trial

Background

The EMPA-HEART trial showed a reduction in left ventricular (LV) mass index by cardiac MRI at 6 months in patients treated with Empagliflozin vs placebo. A secondary analysis of key echocardiographic parameters was performed to provide further insight into the mechanism of LV remodeling.

Methods

All patients enrolled prospectively underwent transthoracic echocardiography (TTE) at baseline and at 6 months. Measurements were performed according to the American Society of Echocardiography guidelines. Key outcomes of interest included changes in diastolic function and right ventricle parameters at 6 months in patients treated with Empagliflozin vs placebo.

Results

A total of 97 patients were enrolled (49 treated with Empagliflozin and 48 in the placebo group). There was no significant difference in the change in average E/E' at 6-months in the Empagliflozin group vs placebo (−0.4 vs +0.2, adjusted difference −0.2, 95% CI [−1.3 to 0.82], p=0.7) Similarly, there was no difference between the groups in secondary TTE parameters (Table 1). Subgroup analyses showed no benefit among patients with baseline LVEF >50% vs. ≤50%, and baseline LV mass index ≥60 g/m2 vs <60 g/m2.

Echocardiographic Parameter Placebo (n=48) Empagliflozin (n=49) Adjusted Difference Between Groups 95% CI P-Value Baseline 6 months Change Baseline 6 months Change LVEF (%)* 55.5 (8.7) 54.3 (8.9) −1.0 (6.5) 58.0 (7.5) 59.1 (8.57) 0.72 (5.1) 2.2 (−0.2, 4.7) 0.1 Diastolic Parameters:   Average E/e' 10.1 (3.1) 10.3 (2.5) 0.2 (3.0) 10.6 (3.0) 10.5 (3.6) −0.4 (2.5) −0.2 (−1.3, 0.8) 0.7   Medial E/e' 12.3 (3.9) 12.5 (3.6) 0.1 (3.7) 12.6 (4.2) 12.6 (5.2) −0.3 (3.3) −0.3 (−1.7, 1.1) 0.7   Lateral E/e' 8.0 (2.8) 8.2 (2.2) 0.2 (2.7) 8.7 (2.6) 8.4 (2.5) −0.4 (2.7) −0.1 (−1.0, 0.8) 0.8   E velocity (cm/sec) 68.6 (15.2) 70.6 (14.7) 1.8 (15.4) 74.4 (18.2) 71.2 (16.8) −3.2 (15.1) −2.3 (−7.9, 3.3) 0.4   A velocity (cm/sec) 74.7 (17.9) 77.9 (18.8) 2.9 (15.9) 76.2 (16.5) 75.8 (14.5) −1.4 (11.7) −3.5 (−8.9, 1.6) 0.2   LA volume index (mL/m2) 32.7 (7.9) 30.8 (8.1) −2.0 (6.7) 30.2 (6.7) 28.7 (5.5) −1.6 (6.5) −0.9 (−3.4, 1.6) 0.5 RV Parameters:   TAPSE (cm) 1.8 (0.5) 1.8 (0.4) 0.1 (0.4) 2.0 (1.2) 1.8 (0.4) −0.3 (1.4) −0.1 (−0.3, 0.1) 0.3   RV S' TDI (cm/sec) 10.9 (2.9) 10.6 (2.5) −0.1 (2.2) 10.4 (2.7) 10.2 (2.6) −0.4 (2.0) −0.3 (−1.2, 0.5) 0.4 *Measured by cardiac MRI. LA, left atrium; LVEF, left ventricular ejection fraction; RV, right ventricle; TAPSE, tricuspid annular plane systolic excursion; TDI, tissue Doppler imaging. Data expressed as mean (standard deviation).

Conclusion

This study showed no significant change in key echocardiographic parameters in patients treated with Empagliflozin, suggesting that changes in loading conditions induced by empagliflozin (i.e. preload) do not mediate the reduction in LV mass.

Inhibitory peptidergic modulation of C. elegans serotonin neurons is gated by T-type calcium channels

Serotonin is an evolutionarily ancient molecule that functions in generating and modulating many behavioral states. Although much is known about how serotonin acts on its cellular targets, how serotonin release is regulated in vivo remains poorly understood. In the nematode C. elegans, serotonin neurons that drive female reproductive behavior are directly modulated by inhibitory neuropeptides. Here, we report the isolation of mutants in which inhibitory neuropeptides fail to properly modulate serotonin neurons and the behavior they mediate. The corresponding mutations affect the T-type calcium channel CCA-1 and symmetrically re-tune its voltage-dependencies of activation and inactivation towards more hyperpolarized potentials. This shift in voltage dependency strongly and specifically bypasses the behavioral and cell physiological effects of peptidergic inhibition on serotonin neurons. Our results indicate that T-type calcium channels are critical regulators of a C. elegans serotonergic circuit and demonstrate a mechanism in which T-type channels functionally gate inhibitory modulation in vivo.

Cesarean section under combined spinal epidural in parturient with frontal glioma

Our patient presented to hospital in acute asthma exacerbation and foetal distress. Past history was remarkable for pregnancy at 35 weeks, morbid obesity, uncontrolled asthma, seizure disorder and known frontal glioma. Here we highlight the neuraxial management of this patient for cesarean section and discuss the central dogma of neuraxial technique in the face of known intracranial neoplasm.

Sonography for the investigation of a child with a limp

Hip pain is a common paediatric presentation and is potentially serious. While hip pain can be attributed to primary hip pathology, the hip area is also a common site for referred pain. This often poses a diagnostic challenge particularly in the young child who may not verbalise the point of pain and may not report an injury.

Differential diagnoses for paediatric hip joint pain range from fracture, transient synovitis, septic arthritis with or without osteomyelitis, juvenile idiopathic arthritis (JIA, previously juvenile rheumatoid arthritis JRA), Legg‐Calve‐Perthes' disease (LCP), slipped capital femoral epiphysis (SCFE) to haemarthrosis in patient with a clotting disorder. Referred pain from abdominal pathology, for example; appendicitis, psoas abscess or haematoma should also be considered.

The evaluation and management of hip pain requires a thorough history and physical examination. A radiograph is usually indicated to rule out any bony injury. Septic arthritis is a medical emergency requiring urgent surgical as well as medical treatment. Ultrasound of the hip joint plays a role in helping to differentiate which hips require early intervention and to guide a needle aspiration of joint fluid if indicated.

In this article, we aim to review the anatomy of the hip, techniques in ultrasonographic examination and some common pathologies in the paediatric hip.

Yunis-varon syndrome: further delineation of cardiovascular and endocrine outcome

Yunis-Varon syndrome is a rare autosomal recessive condition initially characterized by specific skeletal and ectodermal abnormalities, and a poor prognosis, due to neurological and cardiovascular involvement. We describe the cardiovascular and endocrine complications in a 26-year-old man who had been reported previously, adding dilated cardiomyopathy to the clinical features consistent with Yunis-Varon syndrome. Short stature, successfully treated with growth hormone, and hypertension secondary to bilateral renal artery stenosis expand the phenotype.

Coinfection of hepatitis B and hepatitis delta virus in Belgium: a multicenter BASL study. Prospective epidemiology and comparison with HBV mono-infection

Epidemiological data on hepatitis delta virus (HDV) infection in Belgium are lacking. A multicenter questionnaire-based registry on HDV infection was collated between March 1, 2008 and February 28, 2009. It consisted of patients coinfected with hepatitis B virus (HBV) and HDV. The data samples were compared to those of a concurrent registry on HBV infection. Prospective data of patients with HBV-HDV coinfection were collected. Active HBV replication is defined as HBeAg positivity or HBV DNA > 2,000 IU/ml. Forty-four patients from 15 centers were registered. A comparison of 29 patients infected with HDV (registered in the concurrent HBV registry) was made against 785 HBV mono-infected patients. The seroprevalence of patients coinfected with HBV and HDV in Belgium is reported to be 3.7% (29/785), consisting solely of the HBV-HDV coinfected patients in the HBV registry. This rises to 5.5% (44/800) if all patients infected with HDV from the two registries combined are included. The patients coinfected with HBV and HDV had higher (P < 0.05) ALT values and more advanced liver disease (Metavir score ≥F2), but had less active HBV replication and lower HBV DNA titers when compared with the patients infected only with HBV. Additionally, the majority of HBV-HDV coinfected patient was male, and 13.6% (6/44) of the patients that were coinfected HBV and HDV were also infected with HCV. In conclusion, this study provided much needed epidemiological data on the current state of HDV infection in Belgium.

Glycoengineered factor IX variants with improved pharmacokinetics and subcutaneous efficacy

BACKGROUND

The rapid clearance of factor IX (FIX) necessitates frequent intravenous administration to achieve effective prophylaxis for patients with hemophilia B. Subcutaneous administration would be a preferred route of administration but is limited by bioavailability.

OBJECTIVES

To improve the pharmacokinetics (PK) and bioavailability of FIX, a screen was performed to identify positions for the introduction of novel glycosylation sites with maximal effect on PK and maintenance of coagulation activity.

METHODS

Two hundred fifty-one variants, each containing one additional N-linked glycosylation site, were screened in vitro, and the PK profiles of selected variants mapping to spatially distinct regions of FIX were evaluated in mice. Optimal variants were combined, and their PK and efficacy were determined in mice with hemophilia B.

RESULTS

Variants that mapped to spatially distinct regions of the FIX structure exhibited different degrees of improved PK and enabled selection of optimized sites while minimizing the loss of FIX activity. Combining the most effective N-glycan sites in the same FIX molecule resulted in further improvements in PK. An optimized variant containing three novel N-glycan sites (at amino acids 103, 151, and 228), and the activity enhancing 338A variant had double the specific activity of wild-type FIX, exhibited 4.5-fold reduced clearance and 2.4-fold increased subcutaneous bioavailability, and was efficacious at a fivefold lower mass dose than wild-type FIX after subcutaneous injection in a bleeding model in mice with hemophilia B.

CONCLUSIONS

Glycoengineering was used to significantly improve the subcutaneous PK and efficacy of FIX and may have advantages for subcutaneous dosing.

Cardiovascular risk and bone loss in men undergoing androgen deprivation therapy for non-metastatic prostate cancer: implementation of standardized management guidelines

Our objective was to evaluate the effectiveness of implementing standardized guidelines to mitigate metabolic and bone side effects of androgen deprivation therapy (ADT) in men with non-metastatic prostate cancer. We conducted a 2-year prospective cohort study at a tertiary referral teaching hospital. Overall, 236 men (mean age 69.8 ± 7.1) commencing ADT for non-metastatic prostate cancer attended a baseline clinic visit between 2007 and 2011, and 153 men were eligible for follow-up after 2 years of continuous ADT. Of these, 113 men had data available for analysis at 2 years. At baseline, 87% of the men were overweight or obese, 61% had hypertension, 56% had hypercholesterolaemia, 27% prior cardiovascular disease, 11% osteoporosis and 40% osteopaenia. After 2 years of ADT, there was an increase in waist circumference (+2.8 ± 6.3 cm, p = 0.002), and, in men without diabetes, in HbA1c (+0.13 ± 0.34%, p = 0.019). Despite this, due to treatment, there were significant reductions in total cholesterol (-0.35 ± 1.00 mmol/L, p < 0.001), and blood pressure (systolic -7.6 ± 19.3 mmHg; diastolic -4.7 ± 11.6 mmHg, p < 0.001). After 2 years, men not receiving anti-resorptive therapy experienced a significant decline in lumbar spine (-0.042 ± 0.134 g/cm(2) , p = 0.012) and total hip bone mineral density (BMD) (-0.026 ± 0.036 g/cm(2) , p < 0.001), whereas bisphosphonate treatment maintained stable BMD. Prevalence of anaemia increased from 13.8 to 32.5%. Older age independently predicted a greater drop in haemoglobin (p = 0.005). We conclude that a structured approach to assess and treat men undergoing ADT effectively improves cardiovascular risk factors and prevents bone decay. Larger studies are needed to determine effects on cardiovascular outcomes, fracture prevention and survival.

Does antiviral therapy reduce the risk of hepatocellular carcinoma in patients with chronic hepatitis C?

Infection with the Hepatitis C virus (HCV) affects nearly 200 million people in the world. It is a leading cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC). It is estimated that 25% of HCC worldwide is related to HCV, being the main cause in Western Europe, North America and Japan. HCV can be implicated in the development of HCC in an indirect way through induction of chronic inflammation, or directly by means of viral proteins activating several signaling pathways. For patients with clinically significant hepatic fibrosis there is widespread agreement that antiviral therapy is indicated in order to eliminate the virus. It is generally accepted that sustained virologic response (SVR), i.e. undetectable HCV RNA at 24 weeks after treatment withdrawal, is associated with resolution of liver disease in patients without cirrhosis. In the last decades, results of treatment for chronic hepatitis C have improved substantially. The current standard of care is a combination of pegylated interferon and ribavirin for 24 to 48 weeks, depending on the genotype. In the near future, this standard of care will include addition of directly-acting antivirals. In 2011 two protease inhibitors (boceprevir and telaprevir) have been registered for use in adults with genotype 1 chronic hepatitis C, increasing the SVR rates from less than 50% to about 70% in patients treated with a triple combination. There is limited evidence for the role of interferon-based therapy in primary, secondary and tertiary prophylaxis of HCC in patients with chronic Hepatitis C, as most studies were primarily designed to assess the antiviral effect of treatment and not the long-term impact on the natural history of the disease. Further prospective studies using the more successful emerging treatments of chronic hepatitis C are to be conducted to evaluate the risk of HCC.

Viral hepatitis B and hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common cancer in the world, some 630,000 new cases being diagnosed each year. 82% of cases are related to viral hepatitis, 55% to hepatitis B virus (HBV), 89% of those in regions where HBV is endemic. There is a striking parallel between the geographical distribution of the rates of chronic HBV infection and that of HCC. In the majority of HCC cases (70-90%) there is underlying liver cirrhosis. However, because HBV is an oncogenic virus, it can cause HCC in the absence of cirrhosis. The annual risk of HBV-induced HCC varies according to the presence or absence of concomitant cirrhosis. In HBV carriers without cirrhosis, the risk is 0.02-03% in Caucasians and 0.4-0.6% per year in Asians. In those with cirrhosis, the risk is 2.2% and 3.7% respectively in Caucasians and Asians. HBV likely causes HCC via both indirect (necro-inflammation and regeneration injury) and direct (by integration of its DNA in the host genome) pathways. During recent years it has become evident that HBV viral load >2000 IU/mL is associated with a high risk of malignant transformation. The most effective measure of prevention of HBV-related HCC is prevention of HBV infection by vaccination. A universal vaccination program in Taiwan was shown to be effective in reducing the rate of childhood and early adulthood HCC. In patients already infected with HBV, antiviral therapy remains the best strategy. Interferon-alfa therapy appears to be effective in preventing HCC in cirrhosis in Asia but not in Europe. Medium-term nucleos/tide-analogue therapy significantly reduces but does not eliminate the risk of HCC, especially in patients with pre-existing cirrhosis. Maintenance of virological remission is important for the reduction of HCC risk. With more potent antiviral drugs currently available (entecavir, tenofovir), long-term HBV DNA suppression is now possible with very low risk of drug resistance.

Assessing kidney function in Asia

An equation for accurate estimation of the glomerular filtration rate (GFR) is vital for staging and directing the treatment of chronic kidney disease (CKD), which is a source of considerable morbidity and mortality around the world. The Modification of Diet for Renal Disease (MDRD) equation, which includes a racial coefficient, is commonly used. The MDRD equation has been validated in Caucasian populations, but modifying the racial coefficient for Asian countries has resulted in substantially different values that may not be due to race alone. Moreover, it is sometimes difficult to define race, particularly in multi-ethnic populations and among offspring of inter-ethnic marriages. Furthermore, the precision of the MDRD equation is poorer at the early stages of CKD. New markers, such as cystatin C, and new equations may be needed to accurately assess wider ranges of GFR in multi-ethnic countries. We review the development of GFR-estimating equations from an Asian perspective.

Is routine urine cytology useful in the haematuria clinic?

INTRODUCTION

The objective of this study was to determine the value of routine urine cytology in the initial evaluation of patients presenting to a one-stop haematuria clinic.

PATIENTS AND METHODS

A total of 1000 consecutive patients who attended the haematuria clinic between June 2003 and November 2004 were studied prospectively. A standard protocol was used to investigate these patients. This included urine cytology, upper tract imaging and flexible cystoscopy.

RESULTS

Overall, 986 samples of urine were sent for cytology. In 126 patients, the report was abnormal; of these, 71 patients were found to have bladder transitional cell carcinoma by flexible cystoscopy and a further 3 had upper tract transitional cell carcinoma diagnosed radiologically. The remaining 52 patients with abnormal cytology were not found to have cancer on further investigations. The total cost for urine cytology and additional investigations was pound50,535.

CONCLUSIONS

In this study of the initial evaluation of patients with haematuria, no case of urothelial malignancy was diagnosed on the basis of urine cytology alone. Therefore, urine cytology need not be used routinely in the initial diagnostic work-up for haematuria.

Impaired osteoinduction in a rat model for chronic alcohol abuse

Alcohol abuse is a risk factor for bone fractures. Following a fracture, alcoholics have a higher risk for impaired fracture healing. However, the specific alcohol-induced defect(s) in bone healing are not known. Alcohol is a potent inhibitor of bone formation during bone growth and turnover. Thus, the purpose of this study was to determine the effects of alcohol consumption on induction of new bone formation. Demineralized allogeneic bone matrix (DABM) cylinders were used to model osteoinduction in a rat model for chronic alcohol abuse. DABM cylinders, prepared from femurs and tibiae of rats fed a normal diet, were implanted into sexually mature male rats adapted to alcohol (ethanol contributed 35% of caloric intake) or control liquid diets. Food intake in the control rats was restricted to match food intake of alcohol-fed animals. The implants were recovered 6 weeks later and analyzed by histology, muCT and chemical analysis. Histological evaluation revealed a robust osteoinductive response, resulting in mature bone ossicle formation, in DABM implants in rats fed the control diet. Alcohol consumption affected bone mass and architecture of the DABM implants but not volumetric density or mineral composition. Specifically, alcohol consumption resulted in significant decreases in DABM-induced bone volume, bone volume/mg original cylinder weight, connectivity density, trabecular number and thickness, ash weight and % ash weight. There were no changes in mineral (ash) density nor in the relative amounts of calcium, magnesium, iron, selenium and zinc (microg/mg ash), indicating that alcohol consumption did not impair mineralization. Taken together, these results show that alcohol abuse resulted in decreased bone formation within the DABM implant. We conclude that reduced osteoinduction may contribute to impaired bone healing in alcoholics.

Is wheezing associated with decreased sleep quality in Sri Lankan children? A questionnaire study

AIM

To investigate the association between wheezing and impaired sleep in Sri Lankan children, aged 6-12 years; and, to report the prevalence of asthma-related symptoms in these subjects.

METHODS

The International Study of Asthma and Allergies in Childhood questionnaire and a separate sleep questionnaire were completed.

RESULTS

Of 800 originally distributed questionnaires, 652 were analyzed. Wheezing was present in 89 children (14%). Within this group, 66% reported wheezing in the last 12 months. Wheezing children had a significantly higher presence of snoring, restless sleep, nocturnal awakenings and daytime tiredness. Wheezing was found to be independently associated with restless sleep (odds ratio (OR) = 2.4). There was no association between wheezing and difficulties falling asleep, nocturnal awakenings, apneas, and daytime sleepiness and tiredness. After adjusting for possible confounders, the following significant associations were present: snoring and apneas (OR = 1.6), chronic rhinitis and apneas (OR = 1.6), snoring and restless sleep (OR = 3.2), chronic rhinitis and restless sleep (OR = 2.1), and hayfever and daytime tiredness (OR = 4.3). Wheezing was related to an increased risk of snoring (OR = 2.8) and subjects with chronic rhinitis had also an increased risk of snoring (OR = 1.7), adjusting for possible confounders.

CONCLUSION

The sleep of wheezing children was impaired compared with their non-wheezing peers, resulting in an increased prevalence of daytime tiredness. Upper airway symptoms, such as chronic rhinitis or hayfever, should be carefully considered in these children, as they might be responsible for these sleep problems.

Acupuncture for the alleviation of lateral epicondyle pain: a systematic review

OBJECTIVES

Lateral epicondyle pain is a common complaint in North America. In the past 10 yr acupuncture has become increasingly recognized as an alternative treatment for pain, including epicondyle pain. This review evaluates the effectiveness of acupuncture as a treatment for lateral epicondylitis using the appropriate analysis.

METHODS

Online bibliographic database searches in any language from Medline, PsychINFO, CINAHL, Healthstar, PMID, CAM, EMBASE, Cochrane Database of Systematic Review (3rd quarter 2003), articles listed in reference lists of key articles and the author's personal files were performed. Randomized and quasi-randomized controlled trials examining the effects of acupuncture on lateral epicondyle pain were selected. From the six studies that met inclusion criteria, the first author, year of publication, population studied, dropout rate, treatment plan, assessment scale and outcome measures were extracted. Study quality was determined by using the Jadad scale, in which all studies were rated as high quality. A best evidence synthesis approach was used to analyse the data presented in the six studies.

RESULTS

All the studies suggested that acupuncture was effective in the short-term relief of lateral epicondyle pain. Five of six studies indicated that acupuncture treatment was more effective compared to a control treatment.

CONCLUSIONS

There is strong evidence suggesting that acupuncture is effective in the short-term relief of lateral epicondyle pain.

Automated detection of malaria-associated intraleucocytic haemozoin by Cell-Dyn CD4000 depolarization analysis

Laboratory tests for malaria are only performed if there is clinical suspicion of the disease, and a missed diagnosis contributes substantially to morbidity and mortality. Malaria parasites produce haemozoin, which is able to depolarize light and this allows the automated detection of malaria during routine complete blood count analysis (CBC) with some Abbott Cell-Dyn instruments. In this study, we evaluated the Cell-Dyn CD4000 with 831 blood samples submitted for malaria investigations. Samples were categorized as malaria negative (n = 417), convalescent malaria (n = 64) or malaria positive (n = 350) by reference to thin/thick film microscopy, 'rapid test' procedures, polymerase chain reaction analysis and clinical history. With regard to CD4000 depolarization analysis, a malaria positive CD4000 pattern was ascribed to samples that showed one or more abnormal depolarizing purple events, which corresponded to monocytes containing ingested malaria pigment (haemozoin). Positive CD4000 patterns were observed in 11 of 417, 50 of 64 and 281 of 350 of malaria negative, convalescent malaria and malaria positive samples respectively. The specificity and positive predictive values for malaria (active and convalescent) were very high (97.4 and 96.8%, respectively), while sensitivity and negative predictive values were 80.0 and 83.0% respectively. Depolarization analysis was particularly effective for Plasmodium falciparum malaria but there was lower detection sensitivity for White compared with Black African patients. CD4000 90 degrees depolarization vs 0 degrees analysis revealed a proportion of samples with small nonleucocyte-associated depolarizing particles. Appearance of such events in the form of a discrete cluster was associated with P. vivax rather than P. falciparum infection.

Thrombocytopenia in patients with malaria: automated analysis of optical platelet counts and platelet clumps with the Cell Dyn CD4000 analyser

Platelet counts and automated detection of platelet clumps were evaluated by optical analysis with the Abbott CD4000 analyser (Abbott Diagnostics, Santa Clara, CA, USA) in this South African study of 828 samples referred for malaria investigations. Based on microscopy (Micro) and rapid tests (RT) for HRP2 protein and parasite-associated LDH, malaria negative samples (n = 417) were defined as Micro-, RT-. Convalescent cases (n = 64) were Micro-, RT+ and had a recent record of positive microscopy. Malaria positive cases were subdivided into Micro+ (n = 315) and Micro-, RT+, PCR+ (polymerase chain reaction) (n = 32) subgroups. The mean platelet count for Micro+ cases (89.7 x 10(9)/l) was significantly lower than both the malaria negative (mean 212.6 x 10(9)/l) and convalescent malaria (mean 152.8 x 10(9)/l) groups; 89% of microscopy positive cases were thrombocytopenic (< 150 x 10(9)/l) and 30% had severe thrombocytopenia (< 50 x 10(9)/l). For comparison, 32% of the 417 malaria negative samples were thrombocytopenic and 6% of these were severe. Two thirds of samples with parasitaemia above 10% had platelet counts of < 50 x 10(9)/l while the counts were largely independent of parasite numbers when the parasitaemia was below 10%. Thirty percent of samples with microscopically detectable parasites had a PltClmp flag compared to 13% of the malaria negative group but, when the actual platelet count was taken into account, it became apparent that appearance of the flag was primarily associated with thrombocytopenia per se rather than malaria status. In most samples with a PltClmp flag, the CD4000 optical platelet clump 'signature' was indicative of small platelet aggregates and giant platelets. Morphological examination confirmed the presence of varying numbers of small platelet aggregates (3-12 individual platelets), often together with increased giant platelets, in many samples with a PltClmp flag. The observations suggest that while patients with malaria may be predisposed to the development of thrombocytopenia, a reduced platelet count in some patients may also be due in part to pseudo-thrombocytopenia.