Chinese version of the Rotator Cuff Quality of Life questionnaire: Cross-cultural adaptation and validation in rotator cuff-impaired patients in Hong Kong

Purpose:

To adapt the Rotator Cuff Quality of Life (RC-QOL) questionnaire into traditional Chinese (Chi-RC-QOL) and to evaluate the validity and reliability in patients suffering from rotator cuff pathologies in Hong Kong.

Methods:

The Chi-RC-QOL will be constructed using the forward-translation followed by the backward-translation method. Thirty consecutive patients with clinically and radiologically confirmed rotator cuff pathology were recruited. Descriptive statistics will be followed by validity assessment using comparison with the Constant Shoulder (CS) score, University of California Los Angeles (UCLA) Shoulder Rating Scale, and Western Ontario Rotator Cuff (WORC) score. Parametric data will be tested using Pearson’s correlation coefficient for the total scores. Reliability was assessed using a test–retest interval of 30 min. The Cronbach’s α and intraclass correlation coefficient were calculated.

Results:

Cronbach’s α and internal consistency scores were high for all parts of the Chi-RC-QOL, with Cronbach’s α ranging between 0.89 and 0.98. Internal consistency scores range from 0.82 to 0.92, which can be regarded as an excellent correlation. Test–retest reliability was excellent for all parts of the Chi-RC-QOL with good absolute reliability. Chi-RC-QOL correlates well with the CS score, UCLA Shoulder Rating Scale, and the WORC score, with all being statistically significant.

Conclusions:

The current study adapted the RC-QOL to traditional Chinese version. The analysis confirmed the validity and reliability of the Chi-RC-QOL questionnaire.

Level of Evidence:

III.

A Case of Acute Calcific Tendinitis of the Hand: An Uncommon Condition that is Easily Overlooked and Misdiagnosed

Acute calcific tendinitis of the hand is uncommon, yet it has a high rate of misdiagnosis as it resembles other conditions such as fractures, inflammatory and infectious causes that give rise to pain and swelling in the hand. We present a case of acute calcific tendinitis in a middle age woman affecting the extensor pollicis longus to raise awareness of this uncommon, but easily treatable cause of pain and swelling. This case was first diagnosed as septic arthritis of the interphalangeal joint of the thumb. Correct diagnosis was made after careful review of history, physical examination findings, laboratory results and radiographs. (Hong Kong j. emerg.med. 2015;22:316-319)

Can Emergency Medicine Ward Shorten Hospital Length of Stay in Patients with Nasogastric Tube Related Coffee Ground Aspirate?

Introduction

The aim of this study was to determine whether elderly patients on nasogastric (NG) tube feeding who presented with coffee ground aspirate could be effectively and safely managed in a local setting of Emergency Medicine Ward (EMW).

Method

A retrospective study with data retrieved from all the cases admitted with a diagnosis of coffee ground aspirate or vomiting who were on NG tube feeding during three years before and after EMW was launched. Data including patient demographics, length of stay (LOS), types of pharmaceutical treatment received, need of upper endoscopy, in-hospital death and readmission rate within fourteen days were studied. Patients who were haemodynamically unstable, having melaena on per rectal examination, on warfarin or with underlying gastrointestinal malignancy were excluded.

Results

A total of 223 patients matching the studied criteria were included in the study, with 103 of them being admitted before the opening of EMW. For the 120 cases admitted after EMW was launched, 70 cases were admitted to EMW and 50 admitted to Medical Ward. The LOS for elderly patients on NG tube feeding presented with coffee ground aspirate was significantly shortened after EMW was launched (5.2 days vs. 4.2 days, p=0.046). In-hospital mortality and 14-day readmission rate were similar in the two studied period. Patients admitted to EMW and Medical Ward in the second study period were also analysed. Those admitted to EMW had a shorter LOS than those admitted to Medical ward during the same period (3.4 days vs. 5.3 days, p=0.001).

Conclusion

The establishment of EMW in local setting can achieve a significant reduction in hospital LOS without jeopardizing patient outcome for elderly patients who are on NG tube feeding presenting with coffee ground aspirate.

A Retrospective Study of Geriatric Patients Presenting with Fever to an Accident and Emergency Department in Hong Kong

Objectives

To study the characteristics and outcome of geriatric patients presenting with fever to an emergency department in Hong Kong and to analyse the factors affecting their length of stay.

Methods

Retrospective study. Patients aged ≥65 who complained of fever, or with temperature ≥37.5°C (aural) presenting to the Accident and Emergency Department (AED) of Caritas Medical Centre in Hong Kong from 14 November 2006 to 13 December 2006 were enrolled. The demographic data, clinical information and outcomes were studied. The characteristics of short stay and long stay patients were compared.

Results

There were 370 patients in the study. Their median age was 80. Of these patients, 64.9% were category 3 or above, i.e. urgent, emergent or critical. The most common chief complaints were fever, shortness of breath, dizziness and cough. The admission rate was 81.9%. The median length of stay in hospital was 4.3 days. The most common hospital discharge diagnoses were chest infection, urinary tract infection, and fever with unknown cause. The discharge rate within 48 hours was 24.6%. With further analysis, temperature, walking ability, triage category and neutrophil count were significantly different between short stay (≤48 h) and long stay (>48 h) patients. For those discharged alive either from the AED or ward, 20.1% re-attended the AED within 14 days of discharge, and 17.5% of those previously discharged were admitted again for fever or other problems.

Conclusion

Elders with fever are a major challenge to the AED and health care facilities. The admission rate for this group of patients is usually high. Elders with poor walking ability, high triage category, high temperature and neutrophil count were prone to have longer stay.

Atypical periprosthetic femoral fracture: a case report

We report an 82-year-old woman who underwent fixation with a long-spanning cable-plate for a bisphosphonate-induced Vancouver B1 periprosthetic femoral fracture. Non-union and breakage of the plate occurred at 16 months and necessitated revision surgery using a long-stem femoral prosthesis augmented with a cable-plate construct. Bone union was achieved eventually after 10 months.

Efficacy and safety of hylan G-F 20 injection in treatment of knee osteoarthritis in Chinese patients: results of a prospective, multicentre, longitudinal study

OBJECTIVE

To study the efficacy and safety of single intra-articular injection of 6-mL hylan G-F 20 in Chinese patients with symptomatic knee osteoarthritis.

DESIGN

Prospective case series.

SETTING

Six government hospitals in Hong Kong.

PATIENTS

Patients with primary knee osteoarthritis were recruited from six government hospitals from 1 October 2010 to 31 May 2012. All patients received 6-mL intra-articular injection of hylan G-F 20.

MAIN OUTCOME MEASURES

Pain visual analogue scale, functional visual analogue scale, and 5-point Likert scale on change of pain and function were assessed. Adverse events were checked. Radiographs were taken pre-injection and at 3 months and 1 year.

RESULTS

A total of 110 knees of 95 patients with primary knee osteoarthritis were treated. The mean age of the patients was 62 (standard deviation, 9.8) years. All patients completed 1 year of follow-up. The mean pain visual analogue scale, functional visual analogue scale, and Likert value for pain and function showed statistically significant improvements at 6 weeks, 3 months, 6 months, and 1 year compared with the pre-injection values. No significant correlations were found between changes in visual analogue scale and age, body mass index, pre-injection radiological osteoarthritis severity, serum erythrocyte sedimentation rate, or C-reactive protein. Serial radiographs did not show any changes in the radiological severity of knee osteoarthritis. Overall, 16.4% of the patients experienced mild and self-limiting adverse events.

CONCLUSION

Hylan G-F 20 is a safe and effective therapy to relieve pain and improve function for up to 1 year in Chinese patients with knee osteoarthritis.

A combined method to estimate parameters of the thalamocortical model from a heavily noise-corrupted time series of action potential

A combined method composing of the unscented Kalman filter (UKF) and the synchronization-based method is proposed for estimating electrophysiological variables and parameters of a thalamocortical (TC) neuron model, which is commonly used for studying Parkinson's disease for its relay role of connecting the basal ganglia and the cortex. In this work, we take into account the condition when only the time series of action potential with heavy noise are available. Numerical results demonstrate that not only this method can estimate model parameters from the extracted time series of action potential successfully but also the effect of its estimation is much better than the only use of the UKF or synchronization-based method, with a higher accuracy and a better robustness against noise, especially under the severe noise conditions. Considering the rather important role of TC neuron in the normal and pathological brain functions, the exploration of the method to estimate the critical parameters could have important implications for the study of its nonlinear dynamics and further treatment of Parkinson's disease.

Patients with nonalcoholic fatty liver disease have higher risk of colorectal adenoma after negative baseline colonoscopy

AIM

The study aimed to determine whether nonalcoholic fatty liver disease (NAFLD) is an independent risk factor of adenoma after negative baseline colonoscopy.

METHOD

A retrospective cohort study was conducted on 1522 health-check individuals who underwent two consecutive colonoscopies at Taipei Veterans General Hospital between 2003 and 2010. Those developing an adenoma after an initial negative baseline colonoscopy (adenoma group) were compared with those in whom the second colonoscopy was negative (nonadenoma group). Anthropometric measurements, biochemical tests and the presence of NAFLD were compared between the two groups.

RESULTS

The adenoma group had a higher prevalence of NAFLD than the nonadenoma group (55.6% vs 38.8%; P < 0.05). On multivariate logistic regression analysis, NAFLD was an independent risk factor (OR = 1.45, 95% CI: 1.07-1.98) for adenoma formation after a negative baseline colonoscopy. The risk of colorectal adenoma increased when NAFLD patients had other morbidities including metabolic syndrome, hypertension or smoking (OR = 2.85, 4.03 and 4.17).

CONCLUSION

NAFLD is an independent risk factor for colorectal adenoma formation after a negative baseline colonoscopy. The risk is higher in individuals with NAFLD and other comorbidities, such as hypertension, smoking or metabolic syndrome.

Cirrhotic patients at increased risk of peptic ulcer bleeding: a nationwide population-based cohort study

BACKGROUND

Few large population-based studies have compared the occurrence of peptic ulcer bleeding (PUB) in cirrhotic and noncirrhotic patients.

AIMS

To investigate if cirrhotic patients have higher risk of PUB than the general population and to identify possible risk factors of PUB in cirrhotic patients.

METHODS

Using the National Health Insurance Research Database, a nationwide population-based dataset in Taiwan and matching age, gender, comorbidities and ulcerogenic medication by propensity score, 4013 cirrhotic patients, 8013 chronic hepatitis patients and 7793 normal controls were compared. The log-rank test was used to analyse differences in accumulated PUB-free survival rates between the groups. Cox proportional hazard regressions were performed to evaluate independent risk factors for PUB in all patients and identified risk factors of PUB in cirrhotic patients.

RESULTS

During the 7-year follow-up, cirrhotic patients had significantly higher incidences of PUB than chronic hepatitis patients and controls, respectively (P < 0.001 by log-rank test). By Cox proportional hazard regression analysis, cirrhosis was independently associated with increased risk of PUB (hazard ratio: 4.22; 95% CI 3.37-5.29, P < 0.001) after adjusting for age, gender, economic status, underlying comorbidities and ulcerogenic medication. Age, male, diabetes, chronic renal disease, history of gastro-oesophageal variceal bleeding and use of nonsteroidal anti-inflammatory drugs were risk factors for PUB in cirrhotic patients.

CONCLUSION

Cirrhotic patients have a significantly higher risk of peptic ulcer bleeding after adjustments for possible confounding factors like age, gender, economic status, underlying comorbidities and ulcerogenic medication.

Updated thresholds for serum alanine aminotransferase level in a large-scale population study composed of 34 346 subjects

BACKGROUND

The sensitivity of current upper limit of normal (ULN) of serum alanine aminotransferase (ALT) levels for detecting chronic liver disease has been challenged recently.

AIM

To identify modulating factors for serum ALT levels and to refine its ULN threshold.

METHODS

We enrolled 34 346 consecutive subjects who completed the health check-up at Taipei Veterans General Hospital from 2002 to 2009. ULN was set for healthy ALT level to the 95th percentile of the reference healthy population.

RESULTS

A group of 21 282 subjects were used as a training set to define an ULN with the highest sensitivity; afterwards, this ULN was validated in another set of 13 064 subjects. A reference healthy population was selected from the training set after excluding subjects with any abnormalities in independent risk factors associated with elevated serum ALT level (>40 IU/L) by multivariate analysis like body mass index, waist circumference, glucose, cholesterol, high-density lipoprotein-cholesterol, triglyceride, hepatitis B virus surface antigen, anti-hepatitis C virus antibody and fatty liver. The new ULN of serum ALT level defined as the 95% percentile in the healthy population were 21 IU/L and 17 IU/L for men and women respectively. These cut-off values had the highest Youden's index and areas under the corresponding receiver operating curves among four widely applied thresholds in both the training and validation sets.

CONCLUSIONS

The suggested threshold of upper limit of normal provides better discrimination between healthy and unhealthy status. Viral hepatitis, metabolic syndrome and fatty liver are the major risk factors of elevated serum alanine aminotransferase levels.

Hyaluronic acid instillation following arthroscopic anterior cruciate ligament reconstruction: a double-blinded, randomised controlled study

PURPOSE

To assess the effect of hyaluronic acid instillation after arthroscopic anterior cruciate ligament (ACL) reconstruction for improving pain, range of movement, and function of the knee.

METHODS

28 men and 4 women underwent arthroscopic ACL reconstruction for isolated ACL rupture (partial or complete) and instability after recreational sports injury 2 to 120 months earlier. They were randomised to undergo arthroscopic ACL reconstruction followed by intra-articular viscoseal instillation (13 men and 3 women) or arthroscopic ACL reconstruction alone (15 men and 1 woman). The knee injury osteoarthritis outcome score (for pain, symptoms, activities of daily living, sport and recreation function, and quality of life), range of movement, knee circumference, and analgesic use were assessed on days -1, 1, and 2, and weeks 2, 6 and 12.

RESULTS

Patient demographics were similar at baseline. At postoperative days 1 and 2, all subscales of the knee injury osteoarthritis outcome score (except for quality of life) were significantly higher in the viscoseal group. At weeks 2, 6, and 12, improvement in both groups equalised. Knee swelling (change in knee circumference) was significantly less in the viscoseal group at days 1 and 2 (p=0.009 and p=0.038, respectively, Mann-Whitney U test). Only one patient in the viscoseal group had a limited range of movement. No patient developed any adverse reaction.

CONCLUSION

Intra-articular viscoseal instillation improved pain control and swelling 2 days after arthroscopic ACL reconstruction.

Cirrhotic patients at increased risk of peptic ulcer bleeding: a nationwide population-based cohort study

BACKGROUND

Few large population-based studies have compared the occurrence of peptic ulcer bleeding (PUB) in cirrhotic and noncirrhotic patients.

AIMS

To investigate if cirrhotic patients have higher risk of PUB than the general population and to identify possible risk factors of PUB in cirrhotic patients.

METHODS

Using the National Health Insurance Research Database, a nationwide population-based dataset in Taiwan and matching age, gender, comorbidities and ulcerogenic medication by propensity score, 4013 cirrhotic patients, 8013 chronic hepatitis patients and 7793 normal controls were compared. The log-rank test was used to analyse differences in accumulated PUB-free survival rates between the groups. Cox proportional hazard regressions were performed to evaluate independent risk factors for PUB in all patients and identified risk factors of PUB in cirrhotic patients.

RESULTS

During the 7-year follow-up, cirrhotic patients had significantly higher incidences of PUB than chronic hepatitis patients and controls, respectively (P < 0.001 by log-rank test). By Cox proportional hazard regression analysis, cirrhosis was independently associated with increased risk of PUB (hazard ratio: 4.22; 95% CI 3.37-5.29, P < 0.001) after adjusting for age, gender, economic status, underlying comorbidities and ulcerogenic medication. Age, male, diabetes, chronic renal disease, history of gastro-oesophageal variceal bleeding and use of nonsteroidal anti-inflammatory drugs were risk factors for PUB in cirrhotic patients.

CONCLUSION

Cirrhotic patients have a significantly higher risk of peptic ulcer bleeding after adjustments for possible confounding factors like age, gender, economic status, underlying comorbidities and ulcerogenic medication.

Chronic obstructive pulmonary disease: an independent risk factor for peptic ulcer bleeding: a nationwide population-based study

BACKGROUND

Peptic ulcer bleeding remains a major healthcare problem despite decreasing prevalence of peptic ulcer disease. The role of chronic obstructive pulmonary disease (COPD) in the risk of peptic ulcer bleeding has not yet been established.

AIM

To determine if COPD patients have a higher risk of peptic ulcer bleeding than the general population and to identify the risk factors of peptic ulcer bleeding in COPD patients.

METHODS

From Taiwan's National Health Insurance research database, 62,876 patients, including 32,682 COPD and 30,194 age-gender-matched non-COPD controls, were recruited. Cox proportional hazard regression was performed to evaluate independent risk factors for ulcer bleeding in all patients and to identify risk factors in COPD patients.

RESULTS

During the 8-year follow-up, COPD patients had a significant higher rate of peptic ulcer bleeding than the control group (P < 0.001, by log-rank test). By Cox proportional hazard regression analysis, COPD [hazard ratio (HR) 1.93, 95% CI 1.73-2.17] was an independent risk factor after adjusting for age, gender, underlying comorbidities and ulcerogenic medication. Age > 65 years, male, comorbidities of hypertension, diabetes, heart failure, history of peptic ulcer disease, and chronic renal disease and use of nonsteroidal anti-inflammatory drugs were risk factors of ulcer bleeding in COPD patients.

CONCLUSION

Patients with chronic obstructive pulmonary disease have a higher risk of peptic ulcer bleeding after adjustments for possible confounding factors like underlying comorbidities and ulcerogenic medication.

Chronic obstructive pulmonary disease: an independent risk factor for peptic ulcer bleeding: a nationwide population-based study

BACKGROUND

Peptic ulcer bleeding remains a major healthcare problem despite decreasing prevalence of peptic ulcer disease. The role of chronic obstructive pulmonary disease (COPD) in the risk of peptic ulcer bleeding has not yet been established.

AIM

To determine if COPD patients have a higher risk of peptic ulcer bleeding than the general population and to identify the risk factors of peptic ulcer bleeding in COPD patients.

METHODS

From Taiwan's National Health Insurance research database, 62,876 patients, including 32,682 COPD and 30,194 age-gender-matched non-COPD controls, were recruited. Cox proportional hazard regression was performed to evaluate independent risk factors for ulcer bleeding in all patients and to identify risk factors in COPD patients.

RESULTS

During the 8-year follow-up, COPD patients had a significant higher rate of peptic ulcer bleeding than the control group (P < 0.001, by log-rank test). By Cox proportional hazard regression analysis, COPD [hazard ratio (HR) 1.93, 95% CI 1.73-2.17] was an independent risk factor after adjusting for age, gender, underlying comorbidities and ulcerogenic medication. Age > 65 years, male, comorbidities of hypertension, diabetes, heart failure, history of peptic ulcer disease, and chronic renal disease and use of nonsteroidal anti-inflammatory drugs were risk factors of ulcer bleeding in COPD patients.

CONCLUSION

Patients with chronic obstructive pulmonary disease have a higher risk of peptic ulcer bleeding after adjustments for possible confounding factors like underlying comorbidities and ulcerogenic medication.

Direct mapping of hot-electron relaxation and multiplication dynamics in PbSe quantum dots

How hot electrons relax in semiconductor quantum dots is of critical importance to many potential applications, such as solar energy conversion, light emission, and photon detection. A quantitative answer to this question has not been possible due in part to limitations of current experimental techniques in probing hot electron populations. Here we use femtosecond time-resolved two-photon photoemission spectroscopy to carry out a complete mapping in time- and energy-domains of hot electron relaxation and multiexciton generation (MEG) dynamics in lead selenide quantum dots functionalized with 1,2-ethanedithiols. We find a linear scaling law between the hot electron relaxation rate and its energy above the conduction band minimum. There is no evidence of MEG from intraband hot electron relaxation for excitation photon energy as high as three times the bandgap (3E(g)). Rather, MEG occurs in this system only from interband hot electron transitions at sufficiently high photon energies (~4E(g)).

TENOSYNOVIAL OSTEOCHONDROMATOSIS OF BOTH FLEXOR AND EXTENSOR TENDONS

An unusual case of a 52-year-old woman with tenosynovial osteochondromatosis involving both of the wrist flexor and extensor tendons is reported.

Chaotic phase synchronization in small-world networks of bursting neurons

We investigate the chaotic phase synchronization in a system of coupled bursting neurons in small-world networks. A transition to mutual phase synchronization takes place on the bursting time scale of coupled oscillators, while on the spiking time scale, they behave asynchronously. It is shown that phase synchronization is largely facilitated by a large fraction of shortcuts, but saturates when it exceeds a critical value. We also study the external chaotic phase synchronization of bursting oscillators in the small-world network by a periodic driving signal applied to a single neuron. It is demonstrated that there exists an optimal small-world topology, resulting in the largest peak value of frequency locking interval in the parameter plane, where bursting synchronization is maintained, even with the external driving. The width of this interval increases with the driving amplitude, but decrease rapidly with the network size. We infer that the externally applied driving parameters outside the frequency locking region can effectively suppress pathologically synchronized rhythms of bursting neurons in the brain.

Silver Nitrate Stain Masquerading as an Avulsion Fracture of the Finger

We report a case of silver nitrate stain on the finger that masqueraded as an avulsion fracture on radiograph. Radiopacity in the proximal phalanx was demonstrated on radiograph after topical silver nitrate was applied to achieve haemostasis to a bleeding laceration on that area. The radiopacity was initially diagnosed as an avulsion fracture. The correct diagnosis of radiopacity corresponding to silver nitrate application was confirmed by correlation of physical examination with radiographic finding. The lesion spontaneously resolved with conservative management. The importance of correlating the clinical site of silver nitrate application with radiographic finding for accurate diagnosis and avoidance of unnecessary surgical intervention is emphasized.

Experience of a screening centre for influenza A/H1N1: the first 50 days

BACKGROUND

The authors' emergency department (ED) served as Singapore's screening centre for influenza H1N1 cases. The aims of the study were to describe their screening experience and to compare clinical and laboratory features of H1N1 versus seasonal flu cases.

METHODOLOGY

The authors conducted a prospective observational study on consecutive patients aged 16 years and above presenting to a busy, urban ED for H1N1 screening over 50 days. Clinical, laboratory, radiological and PCR data were collected from the hospital electronic databases. Primary outcomes were proportions of confirmed H1N1 cases and their distribution of clinical, laboratory and radiological features. Secondary outcomes were comparison of clinical and laboratory features of H1N1 versus seasonal flu cases. Data were analysed using descriptive statistics and univariate analysis was used to compare factors between the two groups. A p value <0.05 was considered statistically significant.

RESULTS

1205 patients were screened. 31 (2.6%) and 133 (11%) of them had H1N1 and seasonal flu infections, respectively. The two groups had similar symptoms. There were six clinical and two laboratory features with statistically significant differences between H1N1 and seasonal flu cases. Clinical factors were travel or contact history, median age, respiratory rate, diastolic blood pressure and length of hospital stay. Laboratory factors were median platelet and lymphocyte counts.

CONCLUSIONS

The authors report their experience as the nation's H1N1 screening centre. They identified factors that were different between H1N1 and seasonal flu cases. Future research is needed to elucidate if and how this information can be used as a screening tool for H1N1.

Vibrational resonance in neuron populations

In this paper different topologies of populations of FitzHugh-Nagumo neurons have been introduce to investigate the effect of high-frequency driving on the response of neuron populations to a subthreshold low-frequency signal. We show that optimal amplitude of high-frequency driving enhances the response of neuron populations to a subthreshold low-frequency input and the optimal amplitude dependences on the connection among the neurons. By analyzing several kinds of topology (i.e., random and small world) different behaviors have been observed. Several topologies behave in an optimal way with respect to the range of low-frequency amplitude leading to an improvement in the stimulus response coherence, while others with respect to the maximum values of the performance index. However, the best results in terms of both the suitable amplitude of high-frequency driving and high stimulus response coherence have been obtained when the neurons have been connected in a small-world topology.

Harmonics and intermodulation in subthreshold FitzHugh-Nagumo neuron

Intermodulation and harmonics are important in frequency analysis of nonlinear systems. In neuron research, most investigations are taken in studying synchronization between the external stimuli and the output of neuron, but harmonics and intermodulation are often ignored. In this paper, harmonics and intermodulation of the subthreshold FitzHugh-Nagumo neuron are investigated and their magnitudes are used to predict frequency response of the neuron. Furthermore, through analyzing the magnitudes of harmonics, the intrinsic frequencies of the neuron could be identified.

Comparison of total knee arthroplasty using computer-assisted navigation versus conventional guiding systems: a prospective study

PURPOSE

To compare knee alignments in total knee arthroplasty (TKA) using computer-assisted navigation versus conventional guiding systems.

METHODS

Five men and 49 women aged 49 to 79 years underwent TKA for primary osteoarthritis of the knee with varus deformity. All valgus knees were associated with inflammatory arthritis and thus excluded. Computer-assisted navigation was used for the first 35 TKAs, whereas conventional extramedullary tibial and intramedullary femoral guiding systems were used for the next 35 TKAs. The mechanical axis, coronal tibial and femoral angles, sagittal tibial and femoral angles in the 2 groups were compared.

RESULTS

Sagittal tibial and femoral angles aligned more optimally in TKAs using computer-assisted navigation. In the respective computer-assisted navigation and conventional guiding systems, 33 (94%) and 26 (74%) of the TKAs attained a postoperative mechanical axis of <3 degrees varus/valgus.

CONCLUSION

Computer-assisted navigation gives a more consistent alignment correction and reduces outliers during implant positioning.

Kinetic Monte Carlo simulations compared with continuum models and experimental properties of pattern formation during ion beam sputtering

Kinetic Monte Carlo simulations model the evolution of surfaces during low energy ion bombardment using atomic level mechanisms of defect formation, recombination and surface diffusion. Because the individual kinetic processes are completely determined, the resulting morphological evolution can be directly compared with continuum models based on the same mechanisms. We present results of simulations based on a curvature-dependent sputtering mechanism and diffusion of mobile surface defects. The results are compared with a continuum linear instability model based on the same physical processes. The model predictions are found to be in good agreement with the simulations for predicting the early-stage morphological evolution and the dependence on processing parameters such as the flux and temperature. This confirms that the continuum model provides a reasonable approximation of the surface evolution from multiple interacting surface defects using this model of sputtering. However, comparison with experiments indicates that there are many features of the surface evolution that do not agree with the continuum model or simulations, suggesting that additional mechanisms are required to explain the observed behavior.

Stress-enhanced pattern formation on surfaces during low energy ion bombardment

Ion-induced surface patterns (sputter ripples) are observed to grow more rapidly than predicted by current models, suggesting that additional sources of roughening may be involved. Using a linear stability analysis, we consider the contribution of ion-induced stress in the near surface region to the formation rate of ripples. This leads to a simple model that combines the effects of stress-induced roughening with the curvature-dependent erosion model of Bradley and Harper. The enhanced growth rate observed on Cu surfaces appears to be consistent with the magnitude of stress measured from wafer curvature measurements.

Compositionally modulated ripples induced by sputtering of alloy surfaces

Sputtering of an amorphous or crystalline material by an ion beam often results in the formation of periodic nanoscale ripple patterns on the surface. In this Letter, we show that, in the case of alloy surfaces, the differences in the sputter yields and surface diffusivities of the alloy components will also lead to spontaneous modulations in composition that can be in or out of phase with the ripple topography. The degree of this kinetic alloy decomposition can be altered by varying the flux of the ion beam. In the high-temperature and low-flux regime, the degree of decomposition scales linearly with the ion flux, but it scales inversely with the ion flux in the low-temperature, high-flux regime.

Thumb polydactyly: clinical outcome after reconstruction

PURPOSE

To evaluate clinical and cosmetic outcomes of reconstruction in thumb polydactyly and prognostic value of the Wassel classification.

METHODS

Between 1993 and 2000 inclusive, out of the patients with thumb polydactyly (involving 80 thumbs) operated on, 34 patients (36 thumbs) were available for review and underwent clinical and radiological assessment. Outcomes in terms of the Tada score and complications were recorded.

RESULTS

The mean age of patients at the time of operation was 2.8 (range, 0.6-47) years. The mean follow-up period was 5 (range, 2.4-10) years. According to the Wassel classification, 12 were type-II thumb polydactyly, 3 type-III, 11 type-IV, 6 type-V, one type-VI, and 3 type-VII. There was no perioperative mortality or wound infection. More than 88% of the patients were satisfied or very satisfied with functional and cosmetic outcomes. Postoperative complications such as scar hypertrophy, pulp atrophy, joint deformity, and instability were common but minor. Ridge nail deformity after the Bilhaut Cloquet procedure was amenable to secondary corrective procedures. All types of operated thumb polydactyly achieved similar mean Tada scores (14.7- 16.6 out of 20). The Wassel classification category, age, and surgical procedures were found to have no prognostic value with regard to the Tada score and presence of complications.

CONCLUSION

Surgery on thumb polydactyly is rewarding. The Wassel classification category can be used as a guide for treatment, although it fails to predict the occurrence of postoperative complications or Tada scores. Our patients' results can serve as guidelines of expected outcomes after reconstructive procedures in different sub-types of thumb polydactyly.

Breakage of intramedullary femoral guide rod during total knee arthroplasty: a case report

We report a rare complication during primary total knee arthroplasty. An intramedullary femoral guide rod was broken during insertion. The broken part jammed into the isthmus of the femur. An initial attempt to push the broken rod via the proximal femur by a guide wire to the distal femur was unsuccessful because the broken rod was lodged in the isthmus. Ultimately, the isthmus was opened using a flexible 9-mm end-cutting reamer, and the broken rod was pushed down to the distal femoral entry site in an antegrade fashion under image intensification. Selecting a more medial entry site on the intercondylar notch with a smaller valgus cutting angle and using a shorter guide rod can avoid such a breakage.

Feasibility and accuracy of 64-row MDCT coronary imaging from a centre with early experience: a review and comparison with established centres

The accuracy of multi-detector computed tomographic (MDCI) coronary angiography (CTA) is dependant on image quality as well as the experience of the operator. Established centers have reported negative predictive values of over 95%. The aim of our study was to investigate the accuracy and feasibility of CTA for the assessment of haemodynamically significant coronary stenosis in a center with very early experience (<6 months) utilizing the improved spatial and temporal resolutions of the latest generation 64-row MDCI scanner. One hundred and twenty eight patients (93 male, 35 female; mean age 56.2 +/- 9.5 years) with suspected or known coronary artery disease underwent both CIA and conventional coronary angiographv (CCA). The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values for stenoses > or =50% by CIA compared to CCA were 70%, 97%, 70% and 97% respectively. Evaluation of main and proximal segments in patients with good quality images (78% of patients) produced values of 94%, 95%, 74% and 99% respectively. The improved spatial and temporal resolutions of 64-row MJ) CT provided a high negative predictive value in assessing significant coronary artery stenosis even in a centre with very early experience. However, new centers embarking on CTA might not be able to reproduce the results reported by more experienced centers.

Influence of step-edge barriers on the morphological relaxation of nanoscale ripples on crystal surfaces

We show that the decay of sinusoidal ripples on crystal surfaces, where mass transport is limited by the attachment and detachment of atoms at the step edges, is remarkably different from the decay behavior that has been reported until now. Unlike the decreasing or at most constant rate of amplitude decay of sinusoidal profiles observed in earlier work, we find that the decay rate increases with decreasing amplitude in this kinetic regime. The rate of shape invariant amplitude relaxation is shown to be inversely proportional to both the square of the wavelength and the current amplitude. We have also carried out numerical simulations of the relaxation of realistic sputter ripples.

Autotuning positive feedback time delay controller for dead time processes

Biased relay feedback tests are applied to dead time processes to obtain their ultimate gains and ultimate frequencies. First-order process with dead time models are then fitted to the estimated gains and frequencies. A time delay controller that incorporates a simple compensator with a delay element in positive feedback can be derived from the fitted model. The time delay controller gives better performance comparing with classical Ziegler and Nichols tuned PID controller. Experimental study is included to demonstrate the effectiveness of the proposed tuning scheme and the time delay control algorithm.

Leukocyte mitochondria depolarization and apoptosis in advanced heart failure: clinical correlations and effect of therapy

OBJECTIVES

The purpose of this study was to examine the changes in leukocyte mitochondrial transmembrane potential (MTP) and its association with apoptosis in congestive heart failure (CHF).

BACKGROUND

Congestive heart failure is a heterogeneous syndrome with multiple hemodynamic, neuroendocrine and immune abnormalities. Although edematous CHF may be associated with endotoxemia and increased cytokine production, peripheral blood leukocyte functions in advanced CHF remain unclear.

METHODS

Thirty patients with acute decompensated CHF (mean age [+/- SEM] 74.9 +/- 3.1 years) and 20 healthy controls underwent determination of MTP, intracellular oxidants and apoptosis in three subsets of peripheral blood leukocytes. The measurements were repeated after the time of recompensation.

RESULTS

Patients with acute CHF showed marked MTP reduction and increased intracellular oxidant formation in three subsets of leukocytes upon entry into the study. These changes were more prominent in patients with peripheral edema. The decline in MTP was correlated with the severity of the peripheral edema and plasma concentration of cortisol, nitrogen metabolites and tumor necrosis factor-alpha (p < 0.01). After clinical stabilization, MTP gradually recovered. Leukocytes underwent increased propensity of apoptosis one week after the time of recompensation.

CONCLUSIONS

The mitochondrial depolarization and apoptosis of leukocytes in decompensated heart failure suggest that CHF is associated with severity-dependent impairments in leukocyte function. Accentuated hormonal and cytokine abnormalities and increased circulating oxidants may contribute to these changes. Early and aggressive management of advanced heart failure is helpful in the recovery of these immune abnormalities.

Coincidence detection FDG PET in the management of oncological patients: attenuation correction versus non-attenuation correction

The aim of this study was to determine if attenuation correction (AC) in a dual-head, coincidence, positron emission tomography imaging system (Co-PET) improved image quality, lesion detection, patient staging and management of various malignant neoplasms, compared to non-attenuation corrected (NAC) images. Thirty patients with known or suspected malignant neoplasms underwent fluorodeoxyglucose (FDG) Co-PET, which was correlated with histopathology, computed tomography (CT) and other conventional imaging modalities and clinical follow-up. The number and location of FDG avid lesions detected on the AC images and NAC Co-PET images were blindly assessed by two independent observers. Semi-quantitative grading of image clarity and lesion-to-background quality was performed. This revealed markedly improved image clarity and lesion-to-background quality in the AC versus NAC Co-PET images. AC Co-PET was statistically superior to NAC Co-PET in relation to lesion detection (P<0.01) and tumour staging (P<0.01). NAC Co-PET demonstrated 51 of the 65 lesions (78%) detected by AC Co-PET. AC Co-PET altered tumour staging in five additional patients (16%) compared to NAC Co-PET. Management was altered in two of these five patients.

Regulation of ST2L expression on T helper (Th) type 2 cells

T1/ST2L, an IL-1 receptor homologue, is selectively expressed on murine Th2 cells and specific anti-ST2L antibodies can profoundly modulate the Th1/Th2 balance in vivo. Naive CD4+ T cells do not express ST2L but do so on activation with specific antigen in the presence of IL-4 or when stimulated with low doses of antigen in the absence of exogenously added IL-4. Similarly enhanced ST2L expression occurred after stimulation of Th2 cells with antigen or the mitogen ConA in the presence of APC. Restimulation of Th2 cells in the presence of IFN-gamma led to a decreased expression of ST2L to below basal levels. Conversely, Th2 cells cultured with IL-4 led to increased ST2L expression. The reduced expression of ST2L in response to high doses of antigen is also reversed by the neutralization of IFN-gamma. Using an ST2L promoter/luciferase reporter gene construct, we show that the distal but not proximal ST2L promoter is responsible for specific gene expression in Th2 cells. IL-4 enhances, whereas IFN-gamma suppresses ST2L expression via direct modulation of the distal promoter of the ST2L gene. These data provide a mechanistic explanation for the selective expression of ST2L on Th2 cells.

Human IL-18 receptor and ST2L are stable and selective markers for the respective type 1 and type 2 circulating lymphocytes

CD4(+) (Th) and CD8(+) (Tc) T and NK lymphocytes can be divided into type 1 and 2 subsets according to their cytokine secretion profile. Studies on the role of lymphocyte subsets in human diseases have been hampered by the lack of stable surface markers to define them. Recently, we reported that ST2L and IL-18R are stably expressed on murine Th2 and Th1 cells, respectively. In this study, we generated Abs to human homologues of ST2L and IL-18R and tested them against Th1/Th2, Tc1/Tc2, and NK1/NK2 lines and PBMCs from healthy individuals. We show for the first time that ST2L and IL-18R are stable selective cell surface markers for human Th2/Tc2/NK2 and Th1/Tc1/NK1 lymphocytes, respectively. We then investigated PBMCs from HIV-infected patients and HIV-negative individuals, to test whether Abs to these two surface markers could be used directly to monitor lymphocyte subset distribution in human diseases. We found a clear Th1 to Th2 shift in the HIV-infected individuals, thus settling a long-standing controversy and include, for the first time, Tc and NK cells as well. Therefore, these cell surface molecules could serve as important determinants of the immune status of human diseases in general, and thereby could be useful for therapeutic monitoring and intervention.

Enhancement of the anti-herpetic effect of trichosanthin by acyclovir and interferon

Trichosanthin (TCS) is a type I ribosome-inactivating protein that has a wide range of pharmacological activities. The present study investigated the effectiveness of TCS on herpes simplex virus (HSV-1). The anti-viral activity and toxicity of TCS on Vero cells were measured. Results showed that the ED(50), TD(50) and the therapeutic indices were 38.5, 416.5 and 10.9 microg/ml, respectively. Anti-viral activity of TCS was substantially potentiated when it was used in conjunction with other anti-viral agents. The ED(50) of TCS was reduced 125-fold by acyclovir at a concentration of 0.001 microg/ml, which was practically devoid of significant anti-viral activity. Similarly, the ED(50) of TCS was reduced 100-fold by interferon-alpha2a at a concentration of 100 IU/ml. In conclusion, TCS is effective against HSV-1 and other anti-viral agents such as acyclovir or interferon can potentiate its action substantially.

Integrin mobilizes intracellular Ca(2+) in renal vascular smooth muscle cells

Peptides with the Arg-Gly-Asp (RGD) motif induce vasoconstriction in rat afferent arterioles by increasing the intracellular Ca(2+) concentration ([Ca(2+)](i)) in vascular smooth muscle cells (VSMC). This finding suggests that occupancy of integrins on the plasma membrane of VSMC might affect vascular tone. The purpose of this study was to determine whether occupancy of integrins by exogenous RGD peptides initiates intracellular Ca(2+) signaling in cultured renal VSMC. When smooth muscle cells were exposed to 0.1 mM hexapeptide GRGDSP, [Ca(2+)](i) rapidly increased from 91 +/- 4 to 287 +/- 37 nM and then returned to the baseline within 20 s (P < 0.05, 34 cells/5 coverslips). In controls, the hexapeptide GRGESP did not trigger Ca(2+) mobilization. Local application of the GRGDSP induced a regional increase of cytoplasmic [Ca(2+)](i), which propagated as Ca(2+) waves traveling across the cell and induced a rapid elevation of nuclear [Ca(2+)](i). Spontaneous recurrence of smaller-amplitude Ca(2+) waves were found in 20% of cells examined after the initial response to RGD-containing peptides. Blocking dihydropyridine-sensitive Ca(2+) channels with nifedipine or removal of extracellular Ca(2+) did not inhibit the RGD-induced Ca(2+) mobilization. However, pretreatment of 20 microM ryanodine completely eliminated the RGD-induced Ca(2+) mobilization. Anti-beta(1) and anti-beta(3)-integrin antibodies with functional blocking capability simulate the effects of GRGDSP in [Ca(2+)](i). Incubation with anti-beta(1)- or beta(3)-integrin antibodies inhibited the increase in [Ca(2+)](i) induced by GRGDSP. We conclude that exogenous RGD-containing peptides induce release of Ca(2+) from ryanodine-sensitive Ca(2+) stores in renal VSMC via integrins, which can trigger cytoplasmic Ca(2+) waves propagating throughout the cell.

New features of renal lesion induced by stroma free hemoglobin

This study focused on the subacute renal lesions resulting from the infusion of stroma free hemoglobin (SFH), which remains under evaluation as a potential blood substitute despite limited renal toxicity observed in acute infusion. Four groups of rats received different doses of SFH (0.03, 0.48, 0.96, and 1.46 g, respectively) and were monitored, on alternate days, for their glomerular filtration rate over the course of 10 days. Another group of 6 rats receiving 0.96 g SFH was sacrificed at day 10 for examination of renal morphology. The low dose (0.03 g) of SFH infusion did not alter the creatinine clearance (Clcr) over 10 days. The Clcr decreased in rats receiving 0.48 g SFH but fully recovered at day 10. A persistent decrease in Clcr was observed in the groups of rats receiving 0.96 and 1.68 g of SFH. Tubular necrosis was the most prominent renal lesion distributed in the proximal tubules, especially in the convoluted segment of the juxtamedullary nephrons. Pearls' stained cytoplasmic granules and electron-dense lysosomal granules were found in surviving proximal tubules. Necrosis was the predominant mechanism of cell death. This study revealed for the first time proliferation of smooth endoplasmic reticulum in the proximal tubules after SFH treatment, where it appeared as nodular aggregates of tubulovesicular structures. The effect of SFH on the proximal tubule appeared to be a direct toxicity, and this toxicity was shown to be dose dependent. The presence of reversible toxicity indicated that a safety limit dosage for SFH infusion exists and that tolerance dose of SFH can be determined for clinical applications.

Mechanical strain memory in airway smooth muscle

We investigated the effect of a single rapid stretch on poststretch force and myosin phosphorylation in bovine tracheal smooth muscle. When unstimulated muscle strips were stretched from suboptimal length to optimal length (L(o)), poststretch steady-state force was not significantly different from that of unstretched control at L(o). However, when carbachol-activated muscle strips were stretched from suboptimal length to L(o), poststretch force and myosin phosphorylation were lower than control and significantly correlated with initial length. When poststretch muscle strips were allowed to relax for 1 h and then activated by K(+) depolarization, the developed force remained significantly correlated with initial length. When the same strain was applied in 23 increments to minimize peak stress, poststretch force and myosin phosphorylation increased significantly, approaching the levels expected at L(o). Furthermore, poststretch force development increased after each cycle of contraction and relaxation, approaching the control level after four cycles. These results suggest that activated airway smooth muscle cells can retain relatively precise memory of past strain when they are stretched rapidly with high stress.

Trichosanthin interacts with and enters cells via LDL receptor family members

The type-I ribosome-inactivating protein trichosanthin displays selective cytotoxicity, suggesting specific mechanisms for entry into cells. Here we show that trichosanthin binds specifically to the endocytic receptors LRP and megalin, and that binding as well as uptake into cells is inhibited by the receptor-associated protein (RAP). The results suggest that the known abortifacient and renotoxic actions of trichosanthin are caused by LRP-mediated uptake in trophoblasts and megalin-mediated uptake in proximal tubule epithelial cells, respectively.

Engineering of a mini-trichosanthin that has lower antigenicity by deleting its C-terminal amino acid residues

Trichosanthin is a ribosome-inactivating protein that possesses antitumor and antiviral activities. Clinical trials of trichosanthin on AIDS patients, however, elicit anaphylactic reactions. To reduce the antigenicity of trichosanthin as a drug while preserving its biological activity, the C-terminal domain (residues 203 to 247), which contains a putative antigenic site, was systemically deleted. We have found that the minimum length of trichosanthin that can fold into an active conformation is residue 1 to 240. The mini-trichosanthin (C7) generated by deleting the last seven C-terminal amino acid residues has 2.7-fold decrease in antigenicity, 10-fold reduction in in vitro ribosome-inactivation activity, and in vivo cytotoxicity toward K562 cells, and 2-fold reduction in abortificient activity. Structural analyses of C7 indicate decrease in the helix content, increased exposure of Trp192, and lower thermodynamic stability. The deletion of the C-terminal residues (Leu241 to Ala247) probably perturbs local structure of the C-terminal antigenic epitope that results in the decrease in antigenicity and activities of C7.

Planar versus SPET imaging in the assessment of condylar growth

The aim of this study was to compare two methods of quantifying 99Tc(m)-methylene diphosphonate uptake in the mandibular condyle. The study groups consisted of 23 patients with mandibular asymmetry and 16 normal volunteers aged 10-30 years. The accuracy and reproducibility of SPET using condyle-to-clivus ratios was compared with planar analysis using condyle-to-L4 (fourth lumbar vertebra) ratios. Quantitative analysis was correlated with semi-quantitative grading by three observers. Normal ranges for condyle-to-L4 and condyle-to-clivus ratios in individuals aged 11 years or over were determined. These ratios are useful in the serial monitoring of patients with condylar hyperplasia to establish when condylar growth has ceased and hence the type of surgery performed. Visual interpretation of condylar activity should use a combination of planar and SPET images and be performed in conjunction with quantitative analysis. Semi-quantitative grading on SPET images detected more subtle differences in condylar activity than planar images (using quantitative analysis as a standard).

Magnolol attenuates peroxidative damage and improves survival of rats with sepsis

Reactive oxygen species and peroxidative damage are implicated in the pathophysiology of sepsis. Magnolol is a compound extracted from the Chinese medicinal herb Magnolia officinalis and has multiple pharmacological effects, notably antioxidant functions. To determine whether magnolol can modulate the course of sepsis, survival rate and biochemical parameters were analyzed in rats with sepsis with various treatment protocols. Magnolol at doses ranging from 10(-9) g/kg to 10(-5) g/kg was administered either before or after induction of sepsis by cecal ligation and puncture. Magnolol did not modulate the course of sepsis induced by two cecal punctures. When one cecal puncture was performed, a moderately evolving type of sepsis was induced, and the survival rate of affected rats was significantly improved by pretreatment with 10(-7) g/kg magnolol. The beneficial effect was partially retained if magnolol was administered 6 hours after onset of sepsis when a higher dose (10(-5) g/kg) was used. The intensity of lipid peroxidation in plasma, liver, and lung of septic rats was also attenuated in a treatment-dependent manner. Magnolol at this dose range exerted these beneficial effects probably through its antioxidant efficacy. These significant results may suggest magnolol as a candidate agent for the treatment of sepsis.

Retropharyngeal abscess on a Ga-67 scan: a case report

A retropharyngeal abscess is a potentially fatal deep neck infection. Classical symptoms include fever, neck swelling, sore throat, dysphagia, and cervical rigidity. Sometimes small children present with nonspecific symptoms. We report a rare case whereby the Ga-67 citrate scan was the first investigation to reveal an inflammatory process in the retropharyngeal or submastoid region of a 3-year-old child with sepsis. This directed the line of investigation to a more precise anatomic imaging modality, CT scanning, to localize the abscess. With prompt administration of intravenous antibiotics, the child recovered quickly and did not require surgery. The Ga-67 scan is thus a useful screening test to detect inflammatory foci because of its high sensitivity. It is also valuable in the follow-up of the patient's response to therapy.

A proinflammatory role for IL-18 in rheumatoid arthritis

IL-18 is a novel cytokine with pleiotropic activities critical to the development of T-helper 1 (Th1) responses. We detected IL-18 mRNA and protein within rheumatoid arthritis (RA) synovial tissues in significantly higher levels than in osteoarthritis controls. Similarly, IL-18 receptor expression was detected on synovial lymphocytes and macrophages. Together with IL-12 or IL-15, IL-18 induced significant IFN-gamma production by synovial tissues in vitro. IL-18 independently promoted GM-CSF and nitric oxide production, and it induced significant TNF-alpha synthesis by CD14(+) macrophages in synovial cultures; the latter effect was potentiated by IL-12 or IL-15. TNF-alpha and IFN-gamma synthesis was suppressed by IL-10 and TGF-beta. IL-18 production in primary synovial cultures and purified synovial fibroblasts was, in turn, upregulated by TNF-alpha and IL-1beta, suggesting that monokine expression can feed back to promote Th1 cell development in synovial membrane. Finally, IL-18 administration to collagen/incomplete Freund's adjuvant-immunized DBA/1 mice facilitated the development of an erosive, inflammatory arthritis, suggesting that IL-18 can be proinflammatory in vivo. Together, these data indicate that synergistic combinations of IL-18, IL-12, and IL-15 may be of importance in sustaining both Th1 responses and monokine production in RA.