Frequent microbiological surveillance during inpatient cystic fibrosis pulmonary exacerbations has limited clinical value

BACKGROUND

No evidence exists to guide the frequency of obtaining bacterial respiratory cultures during inpatient treatment of pediatric cystic fibrosis (CF) pulmonary exacerbations (PEx). At our institution, admission and weekly respiratory cultures are routinely collected to guide antimicrobial selection. This study evaluates the extent that this practice informs clinical management and the healthcare-related costs associated with routinely repeating cultures.

METHODS

All children with CF with at least one hospital admission for IV antibiotics from January 2015 to December 2019 were included. Data collected included patient demographics, culture results, and antibiotic history. Respiratory cultures were numbered from the last clinic culture (`Culture 1'), culture on admission (`Culture 2'), and so on (`Cultures 3-6'). Outcomes assessed were microbiological results, frequency and timing of antibiotic change, and total microbiological laboratory costs.

RESULTS

Seventy-eight children with 224 admissions and 695 bacterial cultures were analyzed. Repeated microbiology sampling revealed 118 new bacterial species in 82 admissions.  Culture 2 was most likely to identify a new bacterial species (91/115, 79.1 %) and most likely to be followed by a change in antibiotic (33/37; 89.2 %). The total cost of all cultures was $18,264.79. Eliminating Cultures 3-6 from routine practice could represent a 51 % cost-savings ($9,362.89), without significant impact on identification of new clinically relevant isolates.

CONCLUSION

Ongoing bacterial surveillance during a CF PEx beyond admission culture provides minimal information, rarely impacts clinical management, and can increase healthcare costs. An optimized approach would be to routinely obtain admission cultures and to obtain further cultures only if clinically indicated.

Effect of a financial incentive on the acceptance of a smoking cessation programme with service charge: a cluster-controlled trial

INTRODUCTION

Frontline health care professionals in Hong Kong may encounter high refusal rates for the Hospital Authority's Smoking Counselling and Cessation Programme (SCCP) when smokers know it is subject to a service charge. We compared SCCP booking and attendance rates among smokers with or without a financial incentive.

METHODS

In this multicentre non-randomised cluster-controlled trial, adult smokers who attended one of six general out-patient clinics between November 2015 and April 2016 were invited to join an SCCP. Attendees in the three intervention-group centres but not the three control-group centres received a supermarket coupon to offset the service charge.

RESULTS

A total of 173 smokers aged 18 years or older (92 in the intervention group and 81 in the control group) were recruited into the study. In the intervention group, 47 smokers (51%) agreed via a questionnaire that they would join the SCCP, compared with only 23 smokers in the control group (28%). The booking rates were 83% (n=39) in the intervention group and 83% (n=19) in the control group. Among those who had booked a place, 19 (49%) intervention-group participants and 11 (58%) control-group participants attended an SCCP session. Multivariable logistic regression revealed that offering a coupon was associated with agreeing to join an SCCP (odds ratio=4.963, 95% confidence interval=2.173-11.334; P<0.001) and booking an SCCP place (odds ratio=4.244, 95% confidence interval=1.838-9.799; P<0.001).

CONCLUSION

Provision of a financial incentive was positively associated with agreement to join an SCCP and booking an SCCP place. Budget holders should consider providing the SCCP free of charge to increase smokers' access to the service.

Translesional pressure gradient and leptomeningeal collateral status in symptomatic middle cerebral artery stenosis

BACKGROUND AND PURPOSE

Leptomeningeal collateral (LMC) status governs the prognosis of large artery occlusive stroke, although factors determining LMC status are not fully elucidated. The aim was to investigate metrics affecting LMC status in such patients by using computational fluid dynamics (CFD) models based on computed tomography angiography (CTA).

METHODS

In this cross-sectional study, patients with recent ischaemic stroke or transient ischaemic attack attributed to atherosclerotic M1 middle cerebral artery (MCA) stenosis (50%-99%) were recruited. Demographic, clinical and imaging data of these patients were collected. Ipsilesional LMC status was graded as good or poor by assessing the laterality of anterior and posterior cerebral arteries in CTA. A CFD model based on CTA was constructed to reflect focal hemodynamics in the distal internal carotid artery, M1 MCA and A1 anterior cerebral artery. Pressure gradients were calculated across culprit MCA stenotic lesions in CFD models. Predictors for good LMC status were sought in univariate and multivariate analyses.

RESULTS

Amongst the 85 patients enrolled (mean age 61.5 ± 10.9 years), 38 (44.7%) had good ipsilesional LMC status. The mean pressure gradient across MCA lesions was 14.8 ± 18.1 mmHg. Advanced age (P = 0.030) and a larger translesional pressure gradient (P = 0.029) independently predicted good LMCs. A lower fasting blood glucose level also showed a trend for good LMCs (P = 0.058).

CONCLUSIONS

Our study suggested a correlation between translesional pressure gradient and maturation of LMCs in intracranial atherosclerotic disease. Further studies with more exquisite and dynamic monitoring of cerebral hemodynamics and LMC evolution are needed to verify the current findings.

The prognosis of acute symptomatic seizures after ischaemic stroke

OBJECTIVE

Acute symptomatic seizure (AS) after ischaemic stroke is defined as a seizure occurring ≤7 days of the stroke. There remains a lack of information on the prognosis of AS after ischaemic stroke and how it should be treated.

METHODS

We prospectively recruited patients after their incidents of ischaemic stroke from a population-based stroke registry. Stroke aetiology was defined according to Trial-of-ORG-10172 in acute-stroke treatment (TOAST). Patients were examined for any transient complete-occlusion with recanalisation (TCOR) and haemorrhagic transformation. The seizure outcomes were (1) acute clustering of seizures ≤7 days, (2) seizure recurrence associated with stroke recurrence beyond the 7-day period and (3) unprovoked seizure (US) >7 days.

RESULTS

104 patients (mean age 65 years/55% female) with AS after ischaemic stroke were identified (mean follow-up 6.17 years). Comparison of the group of patients with AS and those without seizures showed that patients with AS had significantly less large-vessel and small-vessel disease but more cardioembolisms (p<0.05) and a higher proportion of TCOR (p<0.01), multiple territory infarcts (p=0.007) and haemorrhagic transformations (p<0.01). Using Kaplan-Meier statistics, the risk of acute clustering of seizures ≤7 days was 22%, with a statistical trend for TCOR as a predictive factor (p=0.06). The risk of seizure recurrence associated with worsening/recurrence of stroke beyond 7 days was 13.5% at 2 years, 16.4% at 4 years and 18% at 8 years. Presence of >2 cardiovascular risk factors (p<0.05) and status epilepticus (P<0.05) are predictive risk factors on Cox regression model. The risk of US was 19% at 2 years, 25% at 4 years and 28% at 8 years with epileptiform EEG as a predictive factor (p<0.05).

CONCLUSIONS

Seizure recurrence following AS after ischaemic stroke may appear as acute clustering. Afterwards, seizures may occur as often with a recurrent stroke as without one within 4.2 years. We recommend the use of antiepileptic agents for up to 4 years if the underlying stroke aetiology cannot be fully treated.

Good collateral circulation predicts favorable outcomes in intravenous thrombolysis: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Baseline collateral status has been correlated with outcomes of acute ischaemic stroke patients receiving intravenous thrombolysis (IVT) in previous studies. We carried out the current systematic review and meta-analysis to synthesize currently available evidence regarding such correlations.

METHODS

Full-text articles published since 2000 were retrieved and screened. The overall effect sizes of good versus poor collateral status over a series of outcomes and certain baseline features were estimated by random-effects models and presented in risk ratios (RRs) or mean differences.

RESULTS

Overall, 28 (3057 patients) and 14 (1584 patients) studies were included in qualitative and quantitative synthesis, respectively. Compared with poor pre-treatment collateral status, good collaterals showed a beneficial effect over the primary outcome of a favorable functional outcome at 3 or 6 months [RR, 2.45; 95% confidence interval, 1.94-3.09; P < 0.001] in acute ischaemic stroke patients receiving IVT treatment. However, such an effect tended to be different between studies with prescribed time windows of 3, 4.5 and > 4.5 h (up to 7 h), with the RRs being 2.21, 2.48 and 5.00, respectively (I²  = 53%). Good pre-treatment collaterals were also associated with a smaller infarct size at baseline, and a lower rate of symptomatic intracranial hemorrhage and a higher rate of neurological improvement early after IVT treatment.

CONCLUSIONS

The present study has demonstrated the prognostic value of baseline collateral circulation for outcomes of acute ischaemic stroke patients receiving intravenous reperfusion therapies, studied with different time windows of up to 7 h after ictus for IVT therapy.

Pontine microbleeds and depression in stroke

OBJECTIVES

Depression is the most common affective disorder following stroke yet the neuroanatomical model of poststroke depression (PSD) remains unclear. This study examined the association between PSD and cerebral microbleeds (CMBs) and hypothesized that CMBs in specific regions would be associated with PSD.

METHODS

Of the 4766 patients with first ever or recurrent acute ischemic stroke admitted to the Acute Stroke Unit of the Prince of Wales Hospital between June 2004 and October 2010, 229 met the entry criteria and formed the study sample. Patients with a Geriatric Depression Scale score of 7 or above were classified as having PSD. The presence and location of CMBs were evaluated with magnetic resonance imaging.

RESULTS

Compared to the non-PSD group, patients with PSD were more likely to have pontine CMBs (32.0% vs 18.2%; P = .019). The presence of pontine CMBs remained an independent predictor of PSD in the multivariate analysis, with an odds ratio of 2.2 (P = .016).

CONCLUSION

The results suggest that pontine CMBs are associated with a higher risk of developing PSD.

Location of infarcts and apathy in ischemic stroke

BACKGROUND

Apathy is common in stroke survivors. Unlike poststroke depression, apathy after stroke has not been extensively investigated and the significance of the location of infarcts in the development of apathy following a stroke is unknown. This study examined the association between poststroke apathy (PSA) and the location of infarcts.

METHODS

A cohort of 185 patients with acute ischemic stroke admitted to the Stroke Unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the index stroke, a psychiatrist administered the Apathy Evaluation Scale (AES). PSA was defined as an AES score of 37 or above. The presence and location of infarcts were evaluated with magnetic resonance imaging.

RESULTS

Altogether 185 patients met the entry criteria and formed the study sample; 20 (10.8%) had PSA. PSA patients were older and had higher stroke severity and more depressive symptoms. The PSA group also had lower levels of physical and cognitive functioning. Compared with the non-PSA group, PSA patients were more likely to have acute pontine infarcts (35.0% vs. 11.5%; p = 0.011). They had a higher mean number (0.5 ± 0.7 vs. 0.1 ± 0.3; p = 0.003) and larger volume (0.6 ± 1.4 vs. 0.1 ± 0.3 ml; p = 0.002) of acute pontine infarcts. Six variables were entered into the predictive regression model: age, the presence, number and volume of acute pontine infarcts, the number of old infarcts and periventricular white matter hyperintensities scores. The volume of infarcts remained an independent predictor of PSA in the multivariate analysis, with an odds ratio of 3.9 (p = 0.007). The Geriatric Depression Scale, National Institutes of Health Stroke Scale, Barthel Index and Mini-Mental State Examination scores were also entered into the subsequent associative regression model; the volume of acute pontine infarcts remained a significant predictor (odds ratio = 3.8).

CONCLUSIONS

This is the first report of an association between pontine infarcts and the risk of PSA. The results suggest that pontine infarcts may play a role in the development of PSA. The importance of acute pontine infarcts in the pathogenesis of PSA warrants further investigation.

Serotonin receptor 2C gene polymorphism associated with post-stroke depression in Chinese patients

The serotonin receptor 2C (HTR2C) gene has been shown to play a pivotal role in major depression. We examined the association between post-stroke depression (PSD) and polymorphism in HTR2C. A cohort of 223 patients with acute lacunar stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the onset of the index stroke, a research assistant administered the locally validated 15-item Geriatric Depression Scale. PSD was defined as a geriatric depression scale score of 7 or above. Possible confounding factors, including previous history of stroke, severity of stroke, level of social support, and recent life events, were investigated. All patients were genotyped for polymorphisms of HTR2C. Separate analyses were performed for males and females. Sixty-one patients were found to have PSD. There were significant associations between the HTR2C gene and PSD status in the male patients, but not in the female ones. After adjusting for possible confounders, the rs12837651 T allele (odds ratio = 4.020) and the rs2192371 G allele (odds ratio = 2.866) were found to be significantly associated with PSD in males. Genetic variation in HTR2C receptors appears to be involved in the pathogenesis of PSD in Chinese males.

Poststroke fatigue is associated with caudate infarcts

OBJECTIVE

The caudate nucleus may be involved in the pathogenesis of the fatigue observed in neurological disorders. However, the significance of caudate lesions in poststroke fatigue (PSF) is unknown. This study examined the association between caudate infarcts and PSF.

METHODS

Five hundred Chinese patients with acute ischemic stroke admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong participated in the study. All participants were assessed for PSF with the Fatigue Severity Scale (FSS) three months after their index stroke. PSF was defined as a mean FSS score of 4.0 or more. Physical functioning and depressive symptoms were measured by the Barthel Index (BI) and the Geriatric Depression Scale (GDS).

RESULTS

One hundred and twenty-five (25.0%) of the patients had PSF. Compared to the non-fatigue group, the PSF patients were more likely to be women and had hyperlipidemia, lower BI and higher GDS scores. Caudate (8.0% versus 1.3%, p=0.001) and putamen (19.2% versus 12.0%, p=0.043) acute infarcts were more common in the PSF group, whereas pons infarcts (13.6% versus 22.2%, p=0.038) were less common. Acute caudate infarcts remained an independent predictor of PSF in the multivariate analysis, with an odds ratio of 6.4.

CONCLUSIONS

The results suggest that patients with PSF are more likely to have caudate infarcts.

Autonomic dysfunction in ischemic stroke with carotid stenosis

OBJECTIVES

Impaired autonomic function is common in acute ischemic stroke. Previous limited studies have suggested that atherosclerosis may affect the distensibility of the carotid sinus and then impair the cardiovascular autonomic function. This study sought to investigate cardiovascular autonomic function in patients with ischemic stroke with carotid stenosis.

METHODS

Eighty-five patients with ischemic stroke (58 ones without carotid stenosis and 27 ones with carotid stenosis, average 6 months after stroke onset) and 37 elderly controls were recruited. All performed Ewing's battery autonomic function tests.

RESULTS

From Ewing's battery of autonomic function tests, atypical, definite, or severe autonomic dysfunction was identified in 69.0% patients without carotid stenosis and 88.9% with carotid stenosis, with significant difference between the two groups, and the prevalence of autonomic dysfunction in both groups was higher than that in controls (21.6%). Patients with carotid stenosis showed impairment of all parasympathetic tests (all P < 0.05) and one of the sympathetic tests [Mean fall in systolic blood pressure (BP) on standing: P = 0.051], and those without carotid stenosis only showed impairment in two parasympathetic tests (Valsalva ratio: P = 0.014; heart rate response to deep breathing: P < 0.001) in comparison with controls. Patients with carotid stenosis had significantly more impairment than those without carotid stenosis in some autonomic parameters (Valsalva ratio: P < 0.05; mean fall in systolic BP on standing: P < 0.05).

CONCLUSIONS

Cardiovascular autonomic function is impaired in patients with ischemic stroke, but patients with carotid stenosis show more severely impaired parasympathetic and sympathetic functions.

Predictors of the depressive symptomatology of the family caregivers of Chinese stroke patients in Hong Kong

The aim of this cross-sectional study was to determine the socio-demographic and clinical factors associated with depressive symptoms in the family caregivers of Hong Kong Chinese stroke patients. One hundred and twenty-three patients at a stroke clinic and their family caregivers formed the study sample. The depressive symptoms of both the patients and their family caregivers were rated with the Chinese version of the 15-item Geriatric Depression Scale (GDS). Participants' socio-demographic data and clinical characteristics served as the independent variables in relation to the caregivers' GDS scores. Patients' and caregivers' somatic and psychological conditions were measured with 10 scales. In univariate analysis, caregivers' GDS scores were significantly correlated with certain of their characteristics [Modified Life Event Scale (MLES), Cumulative Illness Rating Scale (CIRS) and Lubben Social Network Scale (LSNS) scores, sex and being a housewife] and those of the patients (GDS score and being a housewife). Multiple regression analysis showed caregivers' MLES and CIRS scores and patients' GDS scores to be independent correlates of caregivers' GDS scores. Adverse events encountered by caregivers in the past 6 months, their current health problems and patients' depressive symptoms were found to be the principal factors associated with caregivers' depressive symptoms.

Intracranial electroencephalogram to evaluate refractory temporal and frontal lobe epilepsy

OBJECTIVE

We undertook a collaborative study in a multidisciplinary team to channel refractory epilepsy patients to test a hypothesis about placement of intracranial electroencephalography arrays.

DESIGN

This was a descriptive case series. Prospective non-invasive presurgical evaluations were based on clinical semiology, magnetic resonance imaging, video-electroencephalography findings and neuropsychological assessments. If the results were discordant, a hypothesis was generated using individualised combinations of positron emission tomography, single-photon emission computed tomography, functional magnetic resonance imaging and Wada tests. The indications for intracranial electroencephalography were: (a) focal magnetic resonance imaging, ictal/interictal scalp electroencephalography with variable results (group A); (b) multi-focal magnetic resonance imaging, focal/multi-focal ictal scalp electroencephalography (group B); (c) non-lesional magnetic resonance imaging, focal/multi-focal ictal scalp electroencephalography (group C). We evaluated whether the seizure-onset zones and eloquent areas were delineated, surgical outcomes (if operated on), and pathology results.

SETTING

A tertiary referral centre for neurology in Hong Kong.

PATIENTS

A total of 105 refractory epilepsy patients completed non-invasive presurgical evaluations over the period 2007 to 2009. Thirty-two patients were eligible for direct resective surgery, and another 25 patients had a testing hypothesis formulated. Of these 25 patients, 10 were eligible for intracranial electroencephalography based on technical/financial considerations.

RESULTS

All 10 patients (group A=2, group B=4, group C=4) had their epileptogenic zones defined. Six patients underwent functional mapping, all of whom had their eloquent areas defined. Seven of the 10 patients underwent resective surgery; four of them achieved Engel class I/II outcomes. The dichotomised outcomes were 100% (group A), 50% (group B), and 33% (group C) achieving Engel class I/II. Two patients had asymptomatic subdural haematoma. There was no intracranial infection or operative mortality. In five (71%) of seven of the patients, a histological diagnosis was established.

CONCLUSION

Proper deployment of intracranial electroencephalography is useful in the presurgical evaluation of patients with refractory epilepsy. This modality of management is potentially of benefit for patients with refractory epilepsy, but is underutilised locally.

ACE gene sequence and nucleotide variants in IgA nephropathy

INTRODUCTION

Association studies with single nucleotide polymorphisms (SNPs) have been contradictory. Haplotypes may be more helpful. With gene sequencing, all SNPs can be found for construction of haplotypes.

METHODS

The ACE gene was sequenced in four healthy Chinese subjects and 20 patients with IgA nephropathy (IgAN) to observe if differences exist among SNPs and haplotypes. 20 patients on angiotensin 1-converting enzyme inhibitor/angiotensin receptor antagonist (ACEI/ATRA) therapy were then compared with another 20 patients not treated with ACEI /ATRA to determine their renal outcome in response to ACEI/ATRA therapy and whether their genetic profile of ACE gene could play a role in determining their outcome to ACEI /ATRA therapy and progression to end-stage renal failure (ESRF).

RESULTS

IgAN patients had 53 variants, of which 17 were unique, whereas normal subjects had 38 variants, of which two were unique (p less than 0.005). No unique variant was a significant risk factor for IgAN. Significant genotype and allele frequency differences in five variants were observed between IgAN patients with renal impairment and those with ESRF (p less than 0.02).

CONCLUSION

Our data suggests that at least in the ACE gene, haplotyping SNPs within a single gene seems to have no added advantage over genotyping the individual component SNPs. The D allele and haplotype 3 confer an adverse prognosis, while the I allele and haplotype 5 appear to be renoprotective. The data suggests that genotypes of the ACE gene are linked to certain haplotypes, which could influence IgAN patients' response to ACEI/ATRA therapy.

Cerebral microbleeds and depression in lacunar stroke

BACKGROUND AND PURPOSE

Cerebral microbleeds (CMB) are common in stroke survivors and the community-dwelling elderly. The clinical significance of CMB in the development of depression after a stroke is unknown. This study examined the association between poststroke depression (PSD) and CMB.

METHODS

A cohort of 235 patients with acute lacunar stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the onset of the index stroke, a research assistant administered the locally validated 15-item Geriatric Depression Scale. PSD was defined as a Genetic Depression Scale score of ≥7. The presence and location of CMB were evaluated with MRI.

RESULTS

In comparison with the non-PSD group, PSD patients were more likely to have lobar CMB (33.3% versus 19.9%; P=0.022). Lobar CMB remained an independent predictor of PSD in the multivariate analysis, with an odds ratio of 2.08 (P=0.032).

CONCLUSIONS

The results suggest that lobar CMB may play a role in the development of PSD. The importance of CMB in the pathogenesis of depression in stroke survivors and the general elderly population warrants further investigation.

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of urinary protein in acute kidney injury

Recent experimental and clinical studies have shown the importance of urinary proteomics in acute kidney injury (AKI). We analyzed the protein in urine of patients with clinical AKI using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) for its diagnostic value, and followed them up for 40 months to evaluate prognosis. Urine from 31 consecutive cases of AKI was analyzed with SDS-PAGE to determine the low, middle and high molecular weight proteins. Fractional excretion of sodium (FENa) was estimated from serum and urine creatinine and sodium (Na). The cases were followed-up for 40 months from the end of the recruitment of study cases. Glomerular protein was higher in the hematuria group when compared with the non-hematuria group (P <0.04) and in the AKI group than in the acute on chronic renal failure (AKI-on-CRF) group (P <0.002). Tubular protein was higher in the AKI-on-CRF group (P <0.003) than in the AKI group. Tubular protein correlated with FENa in groups with diabetes mellitus (DM), AKI-on-CRF, and without hematuria (P <0.03, P <0.02 and P <0.004, respectively). Pattern of protein did not differ between groups with and without DM and clinical acute tubular necrosis (ATN). At the end of 40 months follow-up, category with predominantly glomerular protein progressed to chronic renal failure (CRF) or end-stage renal failure in higher proportion (P <0.05). In clinical AKI, we observed that glomerular protein dominated in cases with glomerular insult, as indicated by hematuria. Tubular protein was common in the study cases with CRF, DM and cases without hematuria. This indicates tubulo-interstitial injury for AKI in these cases. Patients with predominantly glomerular protein had an adverse outcome.

Cerebral microbleeds and symptom severity of post-stroke depression: a magnetic resonance imaging study

BACKGROUND

Cerebral microbleeds (CMBs) are common in stroke survivors, although their clinical significance in the development of psychiatric conditions following stroke remains unknown. This study examines the association between post-stroke depression (PSD) symptom severity and CMBs.

METHODS

Amongst the 4088 patients with acute ischemic stroke who had been admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong, between December 2004 and May 2009, 994 patients were recruited. A psychiatrist administered the Structural Clinical Interview for DSM-IV to all 994 patients and made a diagnosis of PSD three months after the index stroke. PSD symptom severity was assessed with the 15-item Geriatric Depression Scale (GDS). Seventy-eight patients were found to have PSD. The presence and location of CMBs were evaluated with magnetic resonance imaging (MRI).

RESULTS

Seventy-eight patients (7.8%) had PSD. CMBs were identified in 20 PSD patients. Relative to the no-CMB group, the mean GDS score of patients with lobar CMBs was significantly higher (12.6±2.6 versus 10.4±2.5, p=0.01 after adjusting for age, sex, global cognitive functions, neurological deficits and white matter hyperintensities).

LIMITATIONS

Patients with more severe stroke, those who died before the three-month follow-up and those who became depressed later were excluded, as were those unable to give their consent due to dementia or aphasia. These selection biases may limit the generalizability of the findings.

CONCLUSIONS

The results suggest that lobar CMBs may contribute to PSD symptom severity. The importance of CMBs in the pathogenesis of other psychiatric disorders in stroke survivors and other patient populations warrants further investigation.

Impact of patterns of proteinuria on renal allograft function and survival: a prospective cohort study

BACKGROUND

Proteinuria is an important complication in renal transplant recipients. The aim of this prospective study was to evaluate the long-term impact of transplant proteinuria patterns on allograft function and survival.

METHODS

We analyzed urinary protein of a cohort of 83 renal transplants with proteinuria ≥0.5 g/d by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and radial immunogel diffusion assay. After initial stratification and analysis, the cohort was followed up for 16 yr. The graft outcome and survival were analyzed using Cox regression model to determine their association with different patterns of initial transplant proteinuria.

RESULTS

Group with predominantly glomerular (middle- and high-molecular-weight with or without low-molecular-weight) proteinuria (61%) had higher serum creatinine (p < 0.001) than the group with predominantly tubular (low-molecular-weight) proteinuria (39%). The incidences of chronic graft dysfunction and graft loss had increased in the glomerular proteinuria group (p < 0.001, hazard ratio 3.6, 95% confidence interval 1.7-7.5 and p < 0.001, hazard ratio 4.9, 95% confidence interval 1.9-12.1, respectively). Patient death did not differ (p = 0.434, hazard ratio 1.5, 95% confidence interval 0.5-4.5).

CONCLUSION

  Proteinuria in renal transplants can be differentiated into glomerular and tubular types based on molecular weight. Glomerular proteinuria is associated with significant increase in graft dysfunction and graft loss.

Operational definitions improve reliability of the age-related white matter changes scale

BACKGROUND AND PURPOSE

Although the age-related white matter changes (ARWMC) scale has been advocated to be applicable to both MRI and CT for assessing the severity of WMC, its inter-rater reliability on CT is only fair. We aimed to operationalize the ARWMC scale and investigate the effect of this operationalization on the reliability and validity on MRI and CT.

METHODS

Operational definitions of the ARWMC scale were derived from Erkinjuntti research criteria for subcortical vascular dementia and Scheltens scale. Using original and operationalized ARWMC scale, eight observers recorded the time for rating per MRI and per CT. We investigated the inter-rater and intrarater reliability as well as validity against volume using data from 97 stroke patients.

RESULTS

Inter-rater reliability of the operationalized scale on CT (0.874, 95% confidence interval [0.780-0.934]) was better than the original scale (0.569, 95% confidence interval [0.247-0.775]). Its intrarater reliability on CT (0.869) and reliability on MRI (inter-rater: 0.860; intrarater: 0.838) was comparable with the original scale (CT intrarater: 0.750 and on MRI inter-rater: 0.845; intrarater: 0.853). The time required to administer the operationalized scale (4'2″ for MRI and 1'18″ for CT) was similar to that of the original scale (3'56″ for MRI and 1'16″ for CT). The original scale and operationalized scale also significantly correlated with WMC volume (operationalized scale ρ = 0.613, P < 0.001, original scale ρ = 0.638, P < 0.001).

CONCLUSION

Operational definitions improve the inter-rater reliability of ARWMC scale on CT, and it correlates with volumetric measurement.

White matter hyperintensities in post-stroke depression: a case control study

OBJECTIVE

Despite extensive research on post-stroke depression (PSD), the role of white matter hyperintensities (WMHs) in its pathogenesis remains uncertain. The aim of this study was to evaluate the relationship between WMHs and PSD in Chinese patients with first or recurrent stroke.

METHODS

A cohort of 994 patients with acute ischaemic stroke admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. A psychiatrist administered the Structural Clinical Interview for DSM-IV to all patients and made a diagnosis of PSD 3 months after the index stroke. 78 (7.8%) patients had PSD; 78 stroke patients matched according to age and sex but without PSD served as a control group. The severity and location of WMHs were evaluated with MRI.

RESULTS

In comparison with the non-PSD group, patients in the PSD group were more likely to have severe deep WMHs (12.8% vs 1.3%; p=0.009). Severe deep WMHs remained an independent predictor of PSD in the multivariate analysis with an OR of 13.8 (p=0.016).

CONCLUSION

The results suggest that WMHs may play a role in the development of PSD. The importance of WMHs in the treatment and outcome of PSD warrants further investigation.

Genetic polymorphisms of Chinese patients with ischemic stroke and concurrent stenoses of extracranial and intracranial vessels

The etiology of concurrent stenoses of extracranial and intracranial vessels in patients with ischemic stroke is poorly understood, but hereditary factors are believed to be important. We aimed to determine whether genetic polymorphisms affecting homocysteine and lipid metabolism are associated with concurrent stenoses. The genotypes of 191 Han Chinese patients with acute ischemic stroke, of whom 47 (25%) had concurrent stenoses, and 167 healthy control patients in Hong Kong were examined for the following polymorphisms: paraoxonase 1 (PON1) Q192R, methylenetetrahydrofolate reductase (MTHFR) A222V, glutamate-cysteine ligase catalytic-subunit (GCLC)-129C>T, and oxidized low-density lipoprotein receptor (OLR) 3' untranslated region C>T (rs1050283). The genotype distributions of PON1 Q192R and MTHFR A222V, which affect lipid and homocysteine metabolism, differed significantly between patients with stroke and healthy controls. The presence of at least one R allele in PON1 Q192R and a TT allele in OLR rs1050283 were associated with concurrent stenoses. We also identified a possible association between the presence of at least one V allele in MTHFR A222V and concurrent stenoses. This study shows that genetic polymorphisms affecting homocysteine and lipid metabolism are possible risk factors for stroke and concurrent stenoses.

Microbleeds and post-stroke emotional lability

OBJECTIVE

The clinical significance of microbleeds (MBs) in the development of psychiatric conditions following a stroke is unknown. Lesions located in various cortical and subcortical areas are thought to be involved in the pathophysiology of post-stroke emotional lability (PSEL). This study examined the association between PSEL and MBs.

METHODS

A total of 519 Chinese patients with acute ischaemic stroke consecutively admitted to the acute stroke unit of a university affiliated regional hospital in Hong Kong were screened for PSEL 3 months after their index stroke. The number and location of MBs were evaluated with MRI.

RESULTS

According to Kim's criteria, 74 (14.3%) patients had PSEL. In comparison with the non-PSEL group, patients in the PSEL group were more likely to have MBs in the thalamus as a whole (16.2% vs 6.5%; p = 0.004), its anterior (6.9% vs 2.0%, p = 0.02) and paramedian territories (8.1% vs 3.1%; p = 0.04), and a higher number of MBs in the entire brain (1.7+3.4 vs 1.3+5.0; p = 0.031). MBs in the thalamus remained an independent predictor of PSEL in the multivariate analysis, with an odds ratio of 4.7 (p = 0.002).

CONCLUSION

Our results suggest that MBs in the thalamus may play a role in the development of PSEL. The importance of MBs in PSEL and other psychiatric conditions in stroke survivors warrants further investigation.

Use of magnetic resonance angiography to predict long-term outcomes of ischemic stroke patients with concurrent stenoses in Hong Kong

PURPOSE

To determine the long-term outcome of ischemic stroke patients with concurrent intracranial and extracranial atherosclerosis using magnetic resonance angiography.

METHODS

A prospective cohort of patients in Hong Kong with acute ischemic stroke was studied with magnetic resonance angiography of the brain and carotid duplex. All patients were followed up regularly for the development of recurrent stroke, cardiac events, or death.

RESULTS

Totally 343 patients with acute ischemic stroke were included, of whom 104 (30%) had concurrent intracranial and extracranial lesions. The follow-up period was up to 76 months (mean 44.5 months). Overall, 55 patients (15.5%) died of any cause and 91 patients (26.5%) suffered a further nonfatal vascular event. The overall 5-year cumulative rates of mortality, restroke and poor outcomes (combined death and further vascular events) were 18, 27 and 37%, respectively. In patients with concurrent lesions, these rates were 31, 41 and 51%, respectively. The corresponding rates were 13, 22 and 31% in patients without concurrent lesions. The risks were highest in the first year after stroke. More deaths (log rank, 16.3; p = 0.0001), restrokes (log rank, 9.71; p = 0.002) and poor outcomes (log rank, 13.87; p = 0.0001) were found among patients with concurrent lesions. The presence of concurrent vascular lesions, advanced age, smoking, hyperlipidemia and previous history of stroke were independent predictors of poor outcomes.

CONCLUSIONS

The long-term prognosis of ischemic stroke patients with concurrent atherosclerosis of intracranial and extracranial vessels is poor. They are at high risk of further vascular events or death.

Hand-assisted laparoscopic colectomy versus standard laparoscopic colectomy: a cost analysis

OBJECTIVE

There is a relative dearth of literature comparing hand-assisted (HALC) to standard (SLC) laparoscopic colectomies. HALC seems beneficial in terms of shorter operative times and lower conversion rates, but this is counterbalanced by a greater inflammatory response, larger incisions and higher direct costs. Nevertheless, these results are not consistent throughout existing studies and there are to date no detailed cost comparisons. Our hypothesis was that HALC would not incur significantly higher institutional costs compared with standard laparoscopic techniques.

METHOD

Patients undergoing either SLC or HALC between August 2004 and September 2006 were retrospectively reviewed. All patients were managed using a standard protocol. Outcomes assessed included operative times, conversion rates, pain scores, time to resolution of ileus, length of stay and complications. Total costs were calculated from the day of surgery. Statistical analyses included chi(2), Fisher's exact test, the Mann-Whitney U-test or nonparametric bootstrapping method.

RESULTS

Seventy-three patients underwent SLC while 101 had HALC. Demographics and indications for surgery in both groups were similar; the majority were performed for colorectal cancers. Operative times were shorter (147.5 vs 172.5 min, P < 0.05) and complication rates lower (28.7%vs 45.2%, P < 0.025) for HALC. There was no significant difference in the other clinical outcomes. Operative costs and cost of consumables were higher for HALC (US$4024.2 vs US$3568.1, P = 0.01 and US$1724.7 vs US$1302.7, P < 0.001, respectively). However, total costs were not significantly different (HALC US$8999.8, SLC US$7910.7, P = 0.11).

CONCLUSION

Institutional costs are not significantly higher for HALC compared with SLC.

Multiple matching scheme for broadband 0.72Pb(Mg(13)Nb(23))O(3)-0.28PbTiO(3) single crystal phased-array transducer

Lead magnesium niobate-lead titanate single crystal 0.72Pb(Mg(13)Nb(23))O(3)-0.28PbTiO(3) (abbreviated as PMN-PT) was used to fabricate high performance ultrasonic phased-array transducer as it exhibited excellent piezoelectric properties. In this paper, we focus on the design and fabrication of a low-loss and wide-band transducer for medical imaging applications. A KLM model based simulation software PiezoCAD was used for acoustic design of the transducer including the front-face matching and backing. The calculated results show that the -6 dB transducer bandwidth can be improved significantly by using double lambda8 matching layers and hard backing. A 4.0 MHz PMN-PT transducer array (with 16 elements) was fabricated and tested in a pulse-echo arrangement. A -6 dB bandwidth of 110% and two-way insertion loss of -46.5 dB were achieved.

Star fruit intoxication successfully treated by charcoal haemoperfusion and intensive haemofiltration

We report on a case of an elderly woman with chronic renal impairment, secondary to diabetic nephropathy, who developed a deep coma and seizure shortly after consumption of star fruit. She was managed in the intensive care unit, and her consciousness level improved dramatically after an 8-hour charcoal haemoperfusion and 30 hours of continuous haemofiltration. There were no long-term neurological or renal sequelae 9 months later. Early recognition of this condition, intensive dialytic therapy and supportive measures, as well as early initiation of charcoal haemoperfusion may improve the management of this potentially treatable condition.

Agreement between initial and final diagnosis of first seizures, epilepsy and non-epileptic events: a prospective study

BACKGROUND

Differentiating between first seizure, epilepsy and a non-epileptic event is a challenging clinical exercise for many physicians as it may lead to different therapeutic implications. This study aims to investigate the agreement between the initial diagnosis at the accident and emergency (A&E) department and the final diagnosis following inpatient neurological evaluation of seizure disorders.

METHOD

A prospective observational study between April 2004 and June 2005 in a regional hospital in Hong Kong recruited 1701 patients from the A&E to neurology/medical wards with initial diagnoses/labels matching any one of 12 predefined keywords which were categorised as either "seizure specific" or "non-specific".

RESULTS

Among the 1170 patients with "non-specific" initial diagnoses/labels, 58 (5%) were finally diagnosed as having had a first seizure or epilepsy. Among 531 patients with "seizure specific" initial diagnoses/labels, 27 (5.1%) were subsequently diagnosed as having had non-epileptic events. The kappa value for agreement between the initial and final diagnosis was 0.88. Of the 154 patients with a final diagnosis of first seizure, 34 (22%) had "non-specific" initial labels. Among these patients, components of the evaluation contributing to revision of diagnosis included retrieval of witness accounts (47%), epileptiform discharges on EEG (47%), short term monitoring in patients suspected of acute symptomatic seizures (28%) and panel discussion of cases (22%).

CONCLUSION

There was generally a high degree of agreement between the initial and final diagnosis, but first seizures were often missed initially. Careful history taking, judicious use of EEG, selective short term monitoring and liaison with specialists are important in reaching an accurate diagnosis.

Ferroelectric domain in PMN-xPT single crystal studied by piezoresponse force microscopy and finite-element analysis

Ferroelectric domain structures in (001)-cut Pb(Mg(1/3)Nb(2/3))O(3)-38%PbTiO(3) and (011)-cut Pb(Mg(1/3) Nb(2/3))O(3)-60%PbTiO(3) single crystals are studied by means of piezoresponse force microscopy (PFM). The out-of-plane- polarization (OPP) and in-plane-polarization (IPP) domain piezoresponse imaging reveals the domain and domain boundary configurations in these two different PbTiO(3)-content crystals. Finite-element analysis is carried out to illustrate the OPP and IPP-PFM imagings mechanism and interpret the domains superposition phenomenon during PFM imaging.

Refractory epilepsy in a Chinese population

OBJECTIVES

To investigate the proportion of Chinese patients with intractable seizures and the risk factors leading to refractory epilepsy.

METHODS

Consecutive patients over 14 years of age attending a Neurology clinic were evaluated. Patients with epilepsy were classified into two groups according to their seizure control: refractory or seizure-free. Epilepsy was classified as idiopathic as defined by age-related onset and typical electroclinical characteristics, symptomatic if secondary to a structural abnormality and cryptogenic if the cause was unknown. Age, sex, epilepsy syndrome classification, aetiology, presence of mental retardation and the number of drugs used were compared between patients with refractory epilepsy and those in remission.

RESULTS

Among 260 adolescent and adult patients with a mean age of 34 years (range 15-79), complete seizure control was achieved in 157 (60%) cases. Multivariate binomial logistic regression analysis showed that patients with mesial temporal sclerosis (OR=7.6, 95% CI 3.53-16.4, p<0.01) and the presence of mental retardation (OR=9.39, 95% CI 3.98-22.12, p<0.01) were more likely to develop pharmacoresistant epilepsy.

CONCLUSION

In adults the underlying aetiology is an important factor as to whether patients develop intractable seizures. Poor control was also associated with the presence of mesial temporal sclerosis and mental retardation.

Prevalence of asymptomatic intracranial atherosclerosis in high-risk patients

We used transcranial Doppler to screen 3,057 patients who had at least one vascular risk factor of hypertension, diabetes, or hyperlipidemia and found 385 (12.6%) had middle cerebral artery stenosis. Elderly, hypertension, diabetes, and hyperlipidemia were associated factors. The prevalence escalated quadratically with increasing number of associated factors: from 7.2% for one, to 29.6% for four associated factors. Asymptomatic middle cerebral artery stenosis is common in patients with vascular risk factors.

A door-to-door survey of intracranial atherosclerosis in Liangbei County, China

We studied 590 asymptomatic villagers aged > or =40 years in Liangbei County in central rural China and found 41 subjects (prevalence 6.9%) with intracranial atherosclerosis. In a multivariate analysis, the significant risk factors for intracranial stenosis were hypertension (OR 2.53; 95% CI 1.12 to 5.72), glycosuria (OR 3; 1.19 to 7.97), heart disease (OR 4; 1.39 to 11.6), and family history of stroke (OR 5.2; 1.38 to 20). Intracranial atherosclerosis is not uncommon among asymptomatic Chinese subjects.

Spontaneous basilar artery dissection

Dissection of the basilar artery is rare. We report a 51-year-old man who developed acute pontine infarction associated with dissection of the distal basilar artery. There was no trauma or unaccustomed movement of the head and neck prior to the stroke. The dissection was diagnosed non-invasively by magnetic resonance imaging and magnetic resonance angiography. Cervicocerebral artery dissection is a common cause of stroke in young patients particularly when conventional cardiovascular risk factors are absent. Magnetic resonance angiography combined with magnetic resonance imaging is a useful diagnostic tool prior to invasive angiography.

Adsorption of copper ion on magnetite-immobilised chitin

The adsorption of Cu2+ from aqueous solution by magnetite-immobilised chitin (MC) was studied in batch mode. Two conventional adsorbents, cation exchange resin (CER) and activated carbon (AC) were used for the comparison. The physicochemical parameters including pH, concentration of adsorbent, temperature and initial Cu2+ concentration were optimised. Under the optimised conditions, the removal efficiencies of Cu2+ for MC, CER and AC were 91.67, 93.36 and 89.16%, respectively. In addition, the removal capacities of Cu2+ for MC, CER and AC were 56.71, 74.84 and 6.55 mg/g, respectively. The adsorption isotherm studies indicated that the adsorptive behaviour of Cu2+ on three adsorbents could be well described by the Langmuir model. The maximum adsorption capacities (qmax) for MC, CER and AC were 53.19, 89.29 and 5.82 mg/g, respectively. The applicability of the kinetic model has been investigated for MC. Experimental results indicated that a pseudo-second-order reaction model provided the best description of the data with a correlation coefficient 0.999 for different initial Cu2+ concentrations. The rate constants were also determined. Various thermodynamic parameters such as standard free energy (DeltaG 0), enthalpy (DeltaH 0) and entropy (DeltaS 0) were calculated for predicting the adsorption nature of MC. The results indicated that this system was a spontaneous and endothermic process.

Prospective randomized, double-blind, placebo-controlled study of pre- and postoperative administration of a COX-2-specific inhibitor as opioid-sparing analgesia in major colorectal surgery

PURPOSE

To demonstrate the opioid-sparing effect and reduction in postoperative ileus obtained with valdecoxib 40 mg administered pre- and postoperatively in patients undergoing colorectal resection.

METHODS

Patients for elective colorectal resection from December 2002 to June 2004 were randomized to receive either valdecoxib or placebo with standard patient-controlled analgesia (PCA) morphine. In the study arm, the first dose of valdecoxib 40 mg was administered orally as close as possible to 1 h prior to the start of surgery. Each subsequent dose was administered at 24-h intervals up to 120 h. Patients in the control arm were served placebos at the same time-points.

RESULTS

Forty patients were enrolled in the study arm and 39 (excluding one protocol violation) in the control arm. The groups were comparable in age, sex, American Society of Anesthesiology status, body mass index, incision length, and duration and types of operations. Mean PCA doses at 12 and 24 h were 18.6 and 28.3 mg in the study arm vs 26.2 and 41.2 mg in controls, representing a one-third opioid reduction. Bowel sound and movement first appeared at medians of 12 and 72 h in the study arm vs 24 and 84 h, respectively, in controls (P < 0.05). Tolerance of solid diet was at a median of 60 h and discharge at a median of 4 days in the study arm vs 72 h and 6 days in controls (P < 0.05 and P < 0.01, respectively). Seven (18%) morbidities occurred in the control vs six (15%) in the study arm.

CONCLUSIONS

Patients treated with a cyclo-oxygenase 2-specific inhibitor have a shorter recovery time when compared with patients on a standard postoperative PCA morphine-only regimen after colorectal resection.

Apolipoprotein E ?4 allele is associated with the volume of white matter changes in patients with lacunar infarcts

The relationship between the apolipoprotein E (APOE) exon 4 polymorphism and white matter changes (WMC) in elderly subjects or patients with Alzheimer's disease is controversial. To investigate this polymorphism in relation to WMC in patients with lacunar infarcts, we prospectively observed 67 patients with acute lacunar infarct and 134 age- and sex-matched controls. Genotypes were determined using a nested polymerase chain reaction. WMC were measured quantitatively and were divided into two groups, severe and mild, with the mean volume of WMC as the cut point. Twenty-two patients (33%) had severe WMC. There was a significant difference in the distribution of APOE epsilon2, epsilon3, and epsilon4 alleles between severe and mild WMC groups (P = 0.002). The frequency of epsilon4 alleles was higher in patients with severe WMC than in those with mild WMC (25% vs. 7%, P = 0.003). These results suggest that APOE epsilon4 may exacerbate WMC in patients with lacunar infarcts. Further studies are required to confirm this finding.

Sublingual misoprostol compared to artificial rupture of membranes plus oxytocin infusion for labour induction in nulliparous women with a favourable cervix at term

OBJECTIVES

To compare the efficacy of labour induction using sublingual misoprostol versus combined artificial rupture of membranes and oxytocin infusion for nulliparous women with a favourable cervix at term.

DESIGN

Open randomised controlled trial.

SETTING

Regional hospital, Hong Kong.

PATIENTS

Fifty nulliparous women with a favourable cervix (Bishop score 6 or more) at term and indications for labour induction.

INTERVENTIONS

With their informed consent, 100 eligible women were to be randomised to receive either sublingual misoprostol 50 micrograms every 4 hours for up to five doses or oxytocin infusion after artificial rupture of membranes. Interim analysis was planned at a sample size of 50.

MAIN OUTCOME MEASURES

Vaginal delivery within 24 hours of induction.

RESULTS

The study was terminated when interim analysis of the first 50 recruits showed that a significantly smaller proportion of misoprostol-treated women delivered vaginally within 24 hours of induction than in the conventional treatment group (68% vs 100%; relative risk, 0.68; 95% confidence interval, 0.51-0.91; P=0.009), although comparable numbers of women eventually delivered vaginally. The mean induction to vaginal delivery interval was 4.5 hours longer in the misoprostol group (P=0.027). After misoprostol treatment, all women went into labour. Forty percent of them delivered without oxytocin. There was no significant difference in uterine hyperstimulation rate, operative delivery rate, and neonatal outcomes. Maternal satisfaction was higher in the misoprostol group (92% vs 60%; relative risk, 1.53; 95% confidence interval, 1.09-2.16; P=0.008).

CONCLUSIONS

Despite being well accepted by women, labour induction using this regimen of sublingual misoprostol is less effective in achieving vaginal delivery within 24 hours.

Association of smoking with increasing vascular involvement in type 2 diabetic Chinese patients

PURPOSE

To identify the relationship between smoking and the metabolic profile and existing vascular disease in Chinese type 2 diabetic patients.

METHODS

1710 diabetic patients were screened for complications, and biochemical and anthropometric vascular risk factors. As most smokers were male, differences were only compared between male current (n = 196) and never smoking patients (n = 300).

RESULTS

The smokers had higher glycosylated haemoglobin levels (8.2 +/- 2.0 vs. 7.6 +/- 1.8%, p < 0.001) than never smokers, despite a greater proportion receiving hypoglycaemic agents (87.5 vs. 79.6%, p = 0.003). Male smokers compared to never smokers had lower HDL-cholesterol levels (1.12 +/- 0.31 vs. 1.20 +/- 0.30 mmol/L, p = 0.006), and elevated albumin-to-creatinine ratio (3.57 [2.68-4.75] vs. 2.47 [1.99-3.05] mg/mmol, p = 0.040). However, diastolic blood pressure was lower in the smoking group (78 +/- 12 vs. 82 +/- 12 mmHg, p = 0.001) even though they received less blood pressure-lowering treatments (23.8 vs. 33.2%, p = 0.034). The prevalence of peripheral vascular disease was increased in the diabetic patients who smoked compared to nonsmokers (7.1 vs. 2.8%, p = 0.039).

CONCLUSIONS

Smoking was associated with a more adverse metabolic profile and peripheral vascular disease. As mainland China undergoes rapid modernisation and urbanisation, the observed effects of smoking means tobacco control becomes increasingly important to prevent or minimise potential health impacts and chronic disease.

Microfabricated discontinuous-edge surface topographies influence osteoblast adhesion, migration, cytoskeletal organization, and proliferation and enhance matrix and mineral deposition in vitro

The fabrication of surfaces that stimulate increased adhesion, migration, and differentiated function of osteoblasts has been viewed as being desirable for many orthopedic applications. Previous studies have shown that microfabricated pits and grooves alter adhesion, spreading, matrix secretion, and production of mineral by rat calvarial osteoblasts (RCOs). The mechanisms underlying these effects are unknown, although microenvironment and cell alignment are considered to play a role. The aim of this work was to investigate the behavior of RCOs on microfabricated discontinuous-edge surfaces (DESs), which could provide an alternative means to control both the microenvironment and cellular alignment. Two types of discontinuous-type structures were employed, gap-cornered boxes and micron scale pillars. DES gap-cornered boxes and the pillars influenced the arrangement of F-actin, microtubules, and vinculin. Osteoblasts were guided in their direction of migration on both types of substrata. Both box DESs and pillars altered the staining intensity and localization pattern of phosphotyrosine and src-activated FAK localization. Cell multilayering, matrix deposition, and mineralization were enhanced on both discontinuous topographies when compared with smooth controls. This study shows that DESs alter adhesion, migration, and proliferative responses from osteoblasts at early time points (<1 week) and promote multilayering, matrix deposition, and mineral deposition at later times (2-6 weeks). Such topographical patterns could potentially be employed as effective surface features on bone-contacting implants or in membrane-based periodontal applications.

Potential Value of Poststroke Extracranial Arterial Blood Flow Volume in the Prediction of Stroke Functional Outcome

BACKGROUND AND PURPOSE

Cerebral vasoreactivity and collateral circulation are important protective mechanisms against cerebral ischemia. Previous studies suggest that the efficiency of these mechanisms can be reflected by extracranial arterial blood flow volume. Brain damage leading to neurological impairments can influence patients' functional recovery after stroke. This study attempted to explore the potential value of post stroke extracranial arterial blood flow volume in the prediction of stroke patients' functional outcome.

METHODS

We prospectively studied 362 consecutive patients who were hospitalized for recent acute strokes. All patients underwent extracranial arterial blood flow volume measurement of the carotid and vertebral arteries by color velocity imaging quantification within 3 days after admission. Their functional recovery was assessed 6 months after stroke. The effect of post stroke extracranial arterial blood flow volume on patients' functional outcome was tested by multivariate ordinal regression after controlling for other independent variables. Significance was at p<0.05.

RESULTS

Post stroke extracranial arterial blood flow volume together with age, pre-stroke modified Rankin scale, the National Institutes of Health Stroke Scale and diabetes mellitus had significant effects on the patients' 6-month functional outcome as measured by the modified Rankin scale after controlling for other independent variables (p<0.05).

CONCLUSIONS

Post stroke extracranial arterial blood flow volume is an independent outcome predictor. The graded predictive power of this parameter is potentially more superior than other outcome predictors by allowing classification of stroke outcome according to the degree of severity. A large prospective study is thus warranted to investigate its clinical value in the management of stroke patients.

Scoring system for empyema thoracis and help in management

OBJECTIVE

To evaluate the implications of a newly defined severity scoring of empyema in children for the prediction of surgical management and to compare the length of hospitalization as an outcome measure of patients treated using medical therapy, salvage video-assisted thoracoscopic surgery (VATS) vs early elective VATS.

METHODS

A retrospective chart review of parapneumonic empyema of patients below 18 years of age admitted to a tertiary children's hospital in northern Taiwan from April 1993 to December 2002 was performed. Patients were categorized into a medical group who received antibiotic therapy, needle aspirations with/without tube thoracostomy; a salvage VATS group when the patients required surgery for the relief of persistent fever > 38 degrees C, chest pains or dyspneic respirations despite initial medical therapy; an early VATS group when the patients received elective surgery early after admission. The demographic data, clinical features, laboratory findings, and duration of hospitalization were compared using a severity score of empyema (SSE).

RESULTS

Streptococcus pneumoniae was the most common infecting organism, followed by Staphylococcus aureus, Pseudomonas aeruginosa. No organisms were recovered in 39% of patients. A pleural pH < 7.1 increases the odds of requiring surgical intervention by 6 times among this cohort. Children who required decortication of empyema had a higher severity score (mean 4.8 vs 3.0, p < 0.005). The duration of hospitalization for patients having early VATS showed a shortening stay (mean 18 vs 28 days) as compared to salvage VATS.

CONCLUSION

A pleural pH < 7.1 and a newly designed clinical severity score of empyema 4 are two predictors of surgical intervention for fibrinopurulent empyema in the present study. Early elective VATS may be adopted not later than 7 days after failure of appropriate antibiotic therapy and adequate drainage of empyema to decrease the length of stay and minimize morbidity.

Appropriate use of personal protective equipment among healthcare workers in public sector hospitals and primary healthcare polyclinics during the SARS outbreak in Singapore

BACKGROUND

Singapore was affected by an outbreak of severe acute respiratory syndrome (SARS) from 25 February to 31 May 2003, with 238 probable cases and 33 deaths.

AIMS

To study usage of personal protective equipment (PPE) among three groups of healthcare workers (HCWs: doctors, nurses, and administrative staff), to determine if the appropriate PPE were used by the different groups and to examine the factors that may determine inappropriate use.

METHODS

A self-administered questionnaire survey of 14,554 HCWs in nine healthcare settings, which included tertiary care hospitals, community hospitals, and polyclinics, was carried out in May-July 2003. Only doctors, nurses, and clerical staff were selected for subsequent analysis.

RESULTS

A total of 10 236 valid questionnaires were returned (70.3% response); 873 doctors, 4404 nurses, and 921 clerical staff were studied. A total of 32.5% of doctors, 48.7% of nurses, and 77.1% of the administrative staff agreed that paper and/or surgical masks were "useful in protecting from contracting SARS". Among this group, 23.6% of doctors and 42.3% of nurses reported working with SARS patients. The view that a paper and/or surgical mask was adequate protection against SARS was held by 33.3% of doctors and 55.9% of nurses working at the A&E unit, 30.5% of doctors and 49.4% of nurses from medical wards, and 27.5% of doctors and 37.1% of nurses from intensive care units. Factors which predicted for agreement that paper and/or surgical masks were protective against SARS, included HCW's job title, reported contact with SARS patients, area of work, and Impact Events Scale scores.

CONCLUSION

A variety of factors determine appropriate use of personal protective equipment by HCWs in the face of a major SARS outbreak.

Storage and release of femtosecond laser pulses in a resonant photonic crystal

Femtosecond laser pulses with suitable pulse areas are shown to decelerate and stop inside a resonant photonic crystal. The release of the stored fields can be achieved through pulse collision by use of an external optical pulse as a control field. The duty cycle efficiency of the storage and release of light is shown to be as much as 96%. The proposed technique is applied to a real photonic system with finite thickness of atomic layers.

Extent of white matter lesions is related to acute subcortical infarcts and predicts further stroke risk in patients with first ever ischaemic stroke

OBJECTIVE

To investigate whether the extent of white matter lesions (WML) on fluid attenuated inversion recovery (FLAIR) MRI sequences is an independent risk factor for recurrent stroke, and to document the pattern of acute cerebral infarcts using diffusion weighted imaging (DWI) in patients with different severities of WML.

METHODS

In a prospective cohort study, 228 consecutive stroke patients were studied between 1999 and 2001 in a community hospital. The severity of WML was graded as 0 (no WML), 1 (mild), 2 (moderate), or 3 (severe) according to the FLAIR appearances. DWI was used to document the location and size of the infarct.

RESULTS

31 patients had grade 0 WML, 69 had grade 1, 59 had grade 2, and 69 had grade 3. Age was independently associated with WML on logistic regression analysis (p = 0.0001). Acute cerebral infarcts in deep white matter were correlated with increasing severity of WML. On a median follow up of 23.0 months, life table analysis showed that recurrent stroke was related to the severity of WML (recurrence rate 7.8% in grade 0, 9.3% in grade 1, 17.7% in grade 2, 43.7% in grade 3; p = 0.0001). Survival was reduced in patients with severe WML (p = 0.0068). A Cox proportional hazards model showed WML to be predictive of recurrent stroke (p = 0.000, hazard ratio = 4.177 (95% confidence interval, 2.038 to 8.564)) and also for survival (p = 0.040, hazard ratio = 2.021 (1.032 to 3.960)).

CONCLUSIONS

Patients with severe leukoaraiosis have increased risk of deep subcortical stroke and a higher risk of recurrent stroke.

Cushing's syndrome in a patient with a corticotropin-releasing hormone-producing pheochromocytoma

OBJECTIVE

To present the first case of Cushing's syndrome attributable solely to ectopic production of corticotropin-releasing hormone by a pheochromocytoma.

METHODS

We summarize the clinical features and results of laboratory investigations in a patient with symptoms characteristic of Cushing's syndrome.

RESULTS

Although Cushing's syndrome is usually caused by ectopic production of adrenocorticotropic hormone (ACTH), our current patient had clinical and biochemical evidence of hypercortisolism in conjunction with "normal" ACTH levels and nonsuppressible serum and urinary cortisol levels on low-dose and high-dose dexamethasone suppression testing. An abdominal computed tomographic scan revealed a 7.7-cm mass in the left adrenal gland. Light microscopic examination and immunohistochemical staining showed a pheochromocytoma with mild cortical hyperplasia. Immunostaining was positive for corticotropin-releasing hormone but negative for ACTH.

CONCLUSION

To our knowledge, this is the first case of Cushing's syndrome in a patient with pheochromocytoma caused only by ectopic secretion of corticotropin-releasing hormone without accompanying secretion of ACTH.

Laparoscopic-assisted colon and rectal surgery - lessons learnt from early experience

INTRODUCTION

Current evidence shows that laparoscopic bowel surgery is associated with a lower incidence of postoperative ileus, lower postoperative pulmonary and wound complication rates, shorter hospital stays and a quicker return to activity than open surgery. This paper aims to report our early experience with laparoscopic-assisted colorectal procedures in our Centre for Advanced Laparoscopic Surgery and the important lessons we have learnt from this.

MATERIALS AND METHODS

All laparoscopic-assisted colon and rectal surgical (LAC) procedures performed between January 2000 and December 2003 were reviewed. Clinical and operative records of these patients were reviewed. Data retrieved included patient demographics, selected intraoperative parameters, and postoperative outcomes. In order to provide a comparable reference, an equal number of matched open procedures over the same period were accrued and similarly analysed. All patients were managed on a standard carepath. All data were entered into a database and analysed using a statistical software package.

RESULTS

Forty-two laparoscopicassisted colorectal procedures were performed from June 2000 to December 2003. A similar number of diagnosis-matched patients with open colorectal procedures were used as comparison. The diagnoses included cancer (68.5% versus 73.8%), diverticulosis (5.7% versus 9.5%) and polyps (14.3% versus 9.5%). Seven were converted to open surgery because of bleeding, adhesions and locally advanced disease. Laparoscopic-assisted procedures performed included 1 right hemicolectomy, 5 left hemicolectomies, 9 anterior resections, 1 abdominal-perineal resection, 3 sigmoid colectomies, 11 colostomies and 1 Hartmann's procedure. Mean perioperative time (146 min versus 125 min, P = 0.173) was comparatively longer. Mean duration for analgesic requirement (2.25 days versus 2.64 days, P = 0.05), mean length of stay (5.31 days versus 9.07 days, P < 0.05), mean time to commencement of diet (2.91 days versus 4.05 days, P < 0.001) and mean time to first bowel movement (2.57 days versus 4.10 days, P < 0.001) were all comparatively shorter. General morbidity rates (17.1% versus 21.4%, P = 0.35) were lower. No local wound complications were found in our laparoscopic-assisted group. Patients who had undergone open surgery instead of the planned laparoscopic-assisted procedures fared more poorly.

CONCLUSIONS

Laparoscopic-assisted colorectal procedures performed in well-selected patients are associated with shorter hospital stays, quicker return of bowel function and lower morbidity when compared to the matched open procedures. Early experience should be acquired from performing technically simple procedures in patients with benign conditions before progressing to definitive resections in those with cancer.

Electrophysiological, clinical and epidemiological study of Guillain–Barré Syndrome in Hong Kong Chinese

The authors reviewed the clinical and electrophysiological features in 20 consecutive adult patients with Guillain-Barre Syndrome (GBS) admitted to a regional hospital in Hong Kong from 1993 to 1998. The majority of cases in this locality consists of the demyelinating form of GBS; epidemic, acute motor axonal neuropathy is not the predominant form. The incidence of GBS in this region of China was 0.44 per 100,000.