Lentivirus-mediated carboxyl-terminal modulator protein gene transfection via aerosol in lungs of K-ras null mice

The low efficiency of conventional therapies in achieving long-term survival of lung cancer patients calls for development of novel options. Aerosol gene delivery may provide the alternative for safe and effective treatment for lung cancer. Therefore, current study was performed to elucidate the potential effects of C-terminal modulator protein (CTMP) via aerosol on lung tumorigenesis. Lentiviral vector-CTMP was delivered into K-ras null lung cancer mice through the nose-only inhalation system for 30 min. After 48 h, the potential effects of CTMP on Akt1-related signals and cell cycle regulation in the lungs were evaluated by western blot, immunohistochemistry and zymography. Lentivirus-based CTMP delivery inhibited the Akt1 activity through selective suppression of Akt1 phosphorylation at Ser473. Aerosol delivery of CTMP inhibited proteins important for Akt1 signals, cell cycle and tumor metastasis in lungs of K-ras null mice. Together, our results suggest that lentivirus-mediated aerosol delivery of CTMP may be compatible with noninvasive in vivo gene therapy. Our results emphasize the importance of noninvasive-targeted delivery of CTMP for lung cancer therapy in the future. While the studies are conducted in mice, it is envisioned that noninvasive targeting the specific genes responsible for cancer progression is an attractive strategy for effective anticancer therapeutics.

Preoperative endoscopic retrograde cholangiopancreatographic treatment of complicated choledochal cysts in children: a retrospective case series

We report our experience with endoscopic retrograde cholangiopancreatography-(ERCP-)based interventions in children with complicated choledochal cysts that are refractory to conservative management. Between 1999 and 2006, 42 children (12 boys, 30 girls; median age 3 years, range 2-14.5 years) were admitted for surgical treatment of choledochal cysts. Seven of these patients (16.7%; one boy, six girls; median age 3 years, range 2-12 years) showed signs of complicated choledochal cysts, and presented with pancreatitis/cholangitis (n = 4) and obstructive jaundice (n = 3). The anatomical classification of the cysts was type Ic (n = 3), type If (n = 3), and type IV (n = 1). ERCP was successfully performed in 6/7 patients, and therapeutic interventions included removal of debris (n = 3), sphincterotomy (n = 3), and stent placement (n = 4). One patient required blood transfusion for post-sphincterotomy bleeding. The patient in whom the ERCP failed underwent ultrasound-guided percutaneous transhepatic biliary drainage. Definitive surgery was performed after a median interval of 10 days (range 7-68 days) after the ERCP intervention.

Oral hairy leukoplakia arising in an oral lichen planus lesion in an otherwise immune-competent patient

Oral hairy leukoplakia (OHL) presents clinically as thickened white plaques which cannot be rubbed off, and is most often found on the lateral margin of the tongue. The name is derived from its often hairy appearance. OHL has clinical significance because of its association with HIV infection, and it is rare in immune-competent people. We report on a case of unilateral OHL which arose in an oral lichen planus lesion in an immune-competent patient.

Factors influencing pain during transrectal ultrasonography-guided prostate biopsy

We prospectively investigated the clinical parameters that influenced pain during prostate biopsies. From 12 hospitals 1781 patients were enrolled. The patients completed a visual analogue scale questionnaire for the pain during the procedure. Age, enema preparation, analgesia use and number of biopsy punctures influenced the level of pain during prostate biopsy in univariate linear regression analysis. However, multivariate analysis showed enema preparation, analgesia use and number of biopsy punctures were independent factors associated with the pain during the procedure. Our study confirmed enema preparation before biopsy and the number of biopsy punctures were associated with the pain during prostate biopsy.

Inflammatory myofibroblastic tumor of the bladder in children: what can be expected?

Inflammatory myofibroblastic tumor of the bladder is an uncommon condition of unknown neoplastic potential. In adults the tumor is seen in association with instrumentation of the lower genitourinary tract, while in children it appears to run an idiopathic course. Its clinical and radiological presentation in children resembles sarcoma. The case of a 10-year-old girl with inflammatory myofibroblastic tumor is presented, outlining the histological and immunhistochemical features to allow differentiation between sarcomas, the most important differential diagnosis. An outcome meta-analysis of the literature identified 35 cases of inflammatory myofibroblastic tumor in the bladder of children. Conservative surgery is the strategy of choice. There is no evidence of recurrence or metastasis at a median follow up of 1.5 years.

Adiponectin levels in patients with intracranial atherosclerosis

BACKGROUND

Adiponectin is a protein secreted by adipose cells that improves insulin sensitivity and possesses antiatherogenic properties. In this study, we investigated the relationship between adiponectin levels and ischemic stroke subtype.

METHODS

Using clinical, imaging, and laboratory data, 231 consecutive patients admitted to a university medical center over a 2-year period with acute cerebral infarcts were categorized into four subtypes: intracranial atherosclerosis (n = 67), extracranial atherosclerosis (n = 61), small arterial occlusion (n = 63), and cardioembolic (n = 40). Clinical features, risk factors including the presence of metabolic syndrome, and levels of s-adiponectin were compared between groups.

RESULTS

Patients with more severe metabolic abnormalities were more likely to have lower s-adiponectin levels (p = 0.002). S-adiponectin levels differed by stroke subtype: highest in the cardioembolic group and lowest in the intracranial atherosclerosis group (8.42 +/- 5.07 vs 5.60 +/- 2.79 microg/mL, p = 0.01). Extracranial atherosclerosis (6.45 +/- 4.10 microg/mL) and small arterial occlusion (6.07 +/- 3.44 microg/mL) groups were intermediate. Patients with advanced intracranial atherosclerosis (> or =1 additional lesion outside the symptomatic arterial territory) had lower s-adiponectin levels than those with isolated intracranial atherosclerosis (4.95 +/- 2.63 vs 6.13 +/- 2.84 microg/mL, p = 0.003). In multiple regression analysis, s-adiponectin levels, but not metabolic syndrome, were independently associated with intracranial atherosclerosis.

CONCLUSIONS

Symptomatic intracranial atherosclerosis is associated with lower s-adiponectin levels vs other ischemic stroke subtypes.

Aerosol-delivered programmed cell death 4 enhanced apoptosis, controlled cell cycle and suppressed AP-1 activity in the lungs of AP-1 luciferase reporter mice

The long-term survival of lung cancer patients treated with conventional therapies remains poor and therefore the need for novel approaches remains high. This has led to the re-emergence of aerosol delivery as a therapeutic intervention. In this study, glucosylated polyethylenimine (GPEI) was used as carrier to investigate programmed cell death 4 (PDCD4) and PDCD4 mutant (D418A), an eIF4A-binding mutant, on PDCD4-related signaling and activator protein-1 (AP-1) activity in the lungs of AP-1 luciferase reporter mice. After confirming the efficiency of GPEI as a carrier in lungs, the effects of aerosol-delivered PDCD4 were investigated in AP-1 luciferase reporter mice. Aerosol delivery of GPEI/PDCD4 through a nose-only inhalation facilitated the apoptosis of lungs whereas aerosol PDCD4 mutant did not. Also, such aerosol delivery regulated proteins relevant to cell-cycle control and suppressed AP-1 activity. Results obtained by western blot analysis, immunohistochemistry, luciferase assay and deoxynucleotidyl-transferase-mediated nick end labeling study suggest that combined actions such as facilitating apoptosis, controlling cell cycle and suppression of AP-1 activity by PDCD4 may provide useful tool for designing lung tumor prevention and treatment by which PDCD4 functions as a transformation suppressor in the future.

Ablation of paternal accessory sex glands imparts physical and behavioural abnormalities to the progeny: an in vivo study in the golden hamster

The functional significance of male accessory sex glands (ASG) remains unclear. This study explored their importance in reproduction. In previous investigations, embryos sired by males with ASG either totally or partially removed had a shift in the cell cycle and delayed cleavage during preimplantation development, higher incidence of apoptosis, early oviductal-uterine transit, higher proportion of embryo degeneration, lower implantation rate, and ultimately reduced fertility and fecundity. Some pups were born alive; but would they be normal? We hypothesized that the first generation offspring (F1) could also bear undesirable traits. To test our hypothesis, we raised and studied these F1 pups from birth to 8 weeks. We monitored physical growth and assessed behaviour such as nest patch odor preference, acoustic startle response (ASR) and exploratory activity. We detected deviations from the norm in physical growth, a premature cessation of nest patch odor preferences, accelerated acoustic startle habituation and more frequent rearing when exposed to a novel environment. In terms of structure, we found one incidence of diphallus with duplicated urethra. We concluded that sperm lacking contact with ASG secretions gave rise to progeny with abnormal traits.

Association of extracellular cleavage of E-cadherin mediated by MMP-7 with HGF-induced in vitro invasion in human stomach cancer cells

BACKGROUND

Proteolytic shedding of the ectodomain of a variety of transmembrane proteins, including cell-to-cell adhesion molecules, has been observed in solid cancers. We have investigated whether extracellular cleavage of E-cadherin mediated by matrix metalloproteinase-7 (MMP-7) is involved in hepatocyte growth factor (HGF) induced in vitro invasion in stomach cancer cells.

METHODS

The effects of HGF on the expression of E-cadherin/beta-catenin and MMP-7 at both the protein and mRNA levels were assessed in stomach cancer cells, NUGC-3 and MKN-28, and in cells in which the expression of MMP-7 was downregulated by transfection with a MMP-7 short hairpin RNA plasmid.

RESULTS

Treatment with HGF increased the extracellular cleavage of E-cadherin and the release of MMP-7 and reduced the level of E-cadherin in a dose- and time-dependent manner. HGF treatment repressed the phosphorylation of beta-catenin in a Triton-soluble fraction, but enhanced this phosphorylation in a Triton-insoluble fraction. The association of E-cadherin with beta-catenin was decreased by HGF treatment in the Triton-soluble fraction. In addition, treatment of MMP-7 short hairpin RNA transfected NUGC-3 cells with HGF resulted in no extracellular cleavage of E-cadherin and also decreased the in vitro cell invasion.

CONCLUSIONS

These results suggest that incubation with HGF mediated the release of MMP-7, resulting in extracellular cleavage of E-cadherin from stomach cancer cells. This might be a key mechanism in HGF-induced in vitro invasion and metastasis.

Investigation of the corticotropin-releasing hormone-proopiomelanocortin axis in various skin tumours

BACKGROUND

Various types of external stress cause the skin and central neuroendocrine system to express corticotropin-releasing hormone (CRH)-proopiomelanocortin (POMC) axis-related hormones. However, the precise role of the CRH-POMC axis-related hormones in various skin tumours is unclear.

OBJECTIVES

This study examined expression patterns of the CRH-POMC axis-related hormones in skin tumours.

METHODS

The production of CRH, adrenocorticotropic hormone (ACTH) and alpha-melanocyte-stimulating hormone (alpha-MSH) in various tumour cell lines including HaCaT and primary keratinocytes was examined using an enzyme-linked immunosorbent assay. Immunohistochemical analysis of the skin tumours was also performed.

RESULTS

CRH, ACTH and alpha-MSH were strongly expressed in malignant skin tumour cell lines such as G-361 and DX-3 (both malignant melanoma, MM). However, normal and haematological malignancy cell lines did not express the CRH-POMC axis-related hormones. Immunohistochemical analysis of the skin tumours showed that MM (80%), squamous cell carcinoma (SCC, 70%) and basal cell carcinoma (BCC, 10%) had strong immunoreactivity (++/+++) for CRH. Strong ACTH and alpha-MSH expression was observed in MM (70% and 50%, respectively), SCC (80% and 60%, respectively) and BCC (70% and 50%, respectively).

CONCLUSIONS

We report that an increase in the level of the CRH-POMC axis-related hormones is associated with malignant skin tumours such as MM. These results highlight the importance of the CRH-POMC axis-related hormones in the malignant tendency of skin tumours.

Polymeric nanofiber web-based artificial renal microfluidic chip

In this paper, we present a new method for the creation of a smaller dialyzer and do so by incorporating polymeric nanofiber web, which is known to have good filtration efficiency for broad particle sizes, into a poly (dimethylsiloxane)-based microplatform. We have developed a process that makes possible the efficient production of polyethersulfone and polyurethane nanofiber web and that, itself, incorporates an electrospinning method. We have combined the nanofiber web with the PDMS-based microfluidic platform to create a chip-based portable hemodialysis system. With the dialyzing chip, we evaluated the filtration capability of molecules in broad ranges of sizes and compared the filtration capability of nanofiber membranes with that of PES and polyvinylidene fluoride porous membranes (sheet type): we discovered that the nanofiber membranes have better filtration performance than the other membranes. Blood cells were not mechanically affected during their filtration and their transportation through the chip. In conclusion, we have demonstrated the feasibility of chip-based hemodialysis, and we expect that our method suggested in this paper will be applied to the development of small light-weight dialyzers for the realization of portable hemodialysis systems.

Mineral loss from bovine enamel by a 30% hydrogen peroxide solution

This study investigated the effect of a 30% hydrogen peroxide bleaching agent on bovine enamel in terms of mineral loss. Contents of mineral elements both in the teeth and bleaching agent were evaluated to estimate the effect of hydrogen peroxide on teeth. Finely polished non-carious bovine incisors (n = 5) were immersed in a 30% hydrogen peroxide solution for 120 h. The amounts of concentrated elements in the bleaching agent (5 mL) were measured using inductively coupled plasma-atomic emission spectrometer and ion chromatograph. The contents of mineral elements in the teeth were measured using an electron probe microanalyzer. The Ca/P ratio in the bleaching agent was approximately 1.99. The amount of Zn in the bleaching agent was below the detection limit. The total content of mineral elements of the unbleached enamel (90.75 +/- 1.58) was slightly greater than that of the bleached enamel (87.44 +/- 0.77). The Ca/P ratio of the bleached enamel was 2.06. The amount of Ca loss from the bleached enamels after 120 h was similar to the amount of Ca loss from teeth exposed to a soft drink or juice for a few minutes. Therefore, mineral loss caused by the bleaching process may not be a threatening factor to teeth.

A hepaticojejunostomy: technical errors with 'twists and turns'

Excision of a choledochal cyst followed by biliary reconstruction with a Roux-en-Y hepaticojejunostomy is the treatment of choice for type I and IV choledochal cysts. We present a rare complication which was identified 8 years after the original reconstructive surgery. Conventional imaging modalities failed to identify the pathology. Only a contrast enhanced CT scan supported by image rendering software allowed for the visualization of the underlying chronic obstruction of part of the mesentery.

Reversed discrepancy between CT and diffusion-weighted MR imaging in acute ischemic stroke

PURPOSE

We sought to determine whether an early CT ischemic lesion showing parenchymal hypoattenuation might be undetectable on diffusion-weighted imaging (DWI) in acute cerebral ischemia.

MATERIALS AND METHODS

We retrospectively evaluated CT and MR images of 70 consecutive patients with acute middle cerebral artery (MCA) infarction. All patients underwent CT and MR imaging within 6 hours of symptom onset. We determined the presence of reversed discrepancy (RD), defined as an early ischemic lesion showing parenchymal hypoattenuation on CT but no hyperintensity on DWI. CT Hounsfield units (HU), apparent diffusion coefficients (ADCs), and perfusion parameters were calculated for RD lesions.

RESULTS

RD was found in 9 (12.9%) patients and at basal ganglia (89%). The mean HU of RD lesion was lower than that of normal tissue (DeltaHU, 2.33 +/- 0.74, P < .001). RD lesions showed no significant decrease of ADC (ADC ratio, 0.97 +/- 0.07, P = .059) and cerebral blood flow (relative CBF, 0.87 +/- 0.20, P > 0.05). Delayed DWI hyperintensity occurred in 8 (88.8%) RD lesions, and all lesions progressed to infarction. In 6 (66%) of 9 patients with RD, Alberto Stroke Program Early CT scores of ischemic lesions were lower on CT than those on DWI.

CONCLUSION

RD was uncommonly found mainly in basal ganglia, and all RD lesions progressed to infarction at follow-up. Early CT ischemic lesion showing parenchymal hypoattenuation may be undetectable on DWI, and DWI may underestimate extent of severe ischemic tissue in patients with acute MCA infarction.

Seven-day is more effective than 4-day ranitidine bismuth citrate-based triple therapy in eradication of Helicobacter pylori in children: a prospective randomized study

BACKGROUND

Helicobacter pylori infection is common in paediatric population. To date, there is still no universally accepted recommendation on the treatment of this infection in children. Ranitidine bismuth citrate-based triple therapy has been shown to be effective in H. pylori eradication in adults but its use has rarely been validated in children.

AIM

To investigate the efficacy of ranitidine bismuth citrate-based triple therapy in eradication of H. pylori in children and to determine the shortest duration of treatment required.

PATIENTS AND METHODS

We conducted a prospective randomized study comparing ranitidine bismuth citrate plus amoxicillin plus clarithromycin given for 4 days vs. 7 days in H. pylori-infected children diagnosed by (13)C-urea breath test. Eradication was evaluated by repeat (13)C-urea breath test at 6 weeks after treatment.

RESULTS

A total of 206 children were recruited (median age 12 years, 97 boys and 109 girls). Ninety-eight (47.6%) and 108 (52.4%) children were randomized to receive 7-day and 4-day regimen respectively. The eradication rate of 4-day treatment arm was 77.8% (both intention-to-treat and per protocol) compared with 88.8% (intention-to-treat, P = 0.036) and 89.7% (per protocol, P = 0.022) of 7-day regimen. There was no statistical difference in terms of side effects between the two groups.

CONCLUSIONS

Seven-day ranitidine bismuth citrate-based triple therapy is an effective and well-tolerated treatment for eradication of H. pylori in children.

Referral patterns and waiting times for liver transplantation in Singapore

INTRODUCTION

Referral patterns, waiting times, waiting list, and mortality provide information on how effectively a transplant programme deals with referred patients. This paper aims to review these parameters in the Singapore National Liver Transplant Programme.

METHODS

Data of all patients referred to the Singapore National Liver Transplant Programme since its inception were captured and outcomes were retrieved and described.

RESULTS

562 patients were referred for liver transplant evaluation from 1990-2004, consisting of 457 adults and 105 children. The main indications for referral were hepatitis B liver disease and hepatocellular carcinoma in adults, and biliary atresia in children. Most patients were of United Network of Organ Sharing (UNOS) status 3 or 4 at the time of referral. 114 (20.28 percent) patients had transplants, consisting of 66 adults (14.44 percent) and 48 (45.71 percent) children. 138 adults and ten children were rejected for transplant, mainly for the reason of being "too early". The median waiting time for adults who had transplants was 3.3 months while adults still on the waiting list had been waiting for 16.2 months. The overall waiting list mortality was 44.3 percent, being 52.5 percent in adults and 23.2 percent in children.

CONCLUSION

The overall transplantation rate is low and the waiting list mortality is high as a result of low availability of organs, particularly in adults. Paediatric liver transplant appears to have been better at dealing with referred patients but this is probably due to availability of living-related liver transplant. Improvement in these may result from the Human Organ Transplant Act.

Long-term post-liver transplant complications of renal impairment and diabetes mellitus: data from Singapore

INTRODUCTION

Patients who survive the initial post-liver transplantation period face the development of chronic diseases in the long run. We studied two important complications of liver transplantation, namely: renal impairment and diabetes mellitus.

METHODS

We analysed adult patients followed-up for more than one year using data from our liver transplant clinical records. Long-term post-transplant renal impairment (RI) was defined as glomerular filtration rate (GFR) less than 60 ml/min/1.73 square metres and long-term post-transplant diabetes mellitus (DM) was defined as fasting blood glucose more than 7.8 mmol/L, that existed at least one year after liver transplantation. Pre- and post-transplant factors that could be associated with these conditions were examined.

RESULTS

Altogether, 35 patients were evaluated. Mean age at transplant was 50 years. Mean duration of follow-up was 58.4 months. There was 11.4 percent of pre-transplant RI and 17.0 percent of pre-transplant DM. Prevalence of post-transplant RI was 43.5 percent at one year and 45.0 percent at four years. Long-term post-transplant RI was associated with renal impairment at six months post-transplant (p-value is 0.033). Prevalence of severe post-transplant RI (GFR is less than 30 ml/min/1.73 square metres) at four years was 5.7 percent. Prevalence of post-transplant DM was 45.5 percent at two years but declined to 5.3 percent at four years.

CONCLUSION

Post-transplant renal impairment appears to be a potential long-term problem while post-transplant diabetes mellitus appears to improve with time.

MELD may not be the better system for organ allocation in liver transplantation patients in Singapore

INTRODUCTION

The Model for End-Stage Liver Disease (MELD) score is a good predictor of mortality on the liver transplant waiting list and is the current system of organ allocation in the USA. However, a higher MELD may be associated with poorer outcome post-liver transplantation. The aim of this study was to determine if MELD should be implemented as the system for organ allocation for liver transplantation in Singapore.

METHODS

There were 46 adult patients who underwent primary liver transplantation at the National University Hospital, Singapore from January 1996 to December 2002. We applied the MELD score to patients who were transplanted and looked for a correlation with survival post-transplant. Patients were followed-up until the most recent visit or death. Survival analysis was performed using Cox regression and Kaplan-Meier method.

RESULTS

The mean age at transplant was 52.7 (SD 2.34) years. The majority of the patients transplanted had Hepatitis B (43 percent). The median MELD score at transplantation was 17 (7-42) and the median Child's score was 11 (6-15). There was a significant correlation between pre-transplant MELD and survival at six months (p-value is 0.037, 95 percent confidence interval [CI] is 1.004-1.13) but not at one year (p-value is 0.065, 95 percent CI is 0.99-1.12). There were no differences in the pre-transplant MELD (odds-ratio [OR] 1, 95 percent CI 0.9-1) as well as survival for patients with and without Hepatitis B (OR 0.72, 95 percent CI 0.22-2.35).

CONCLUSION

MELD allows livers to be allocated to the patients with the greatest medical urgency but its influence on post-transplant survival should be further clarified so that post-transplant survival is not compromised.

Liver transplantation in Singapore 1990-2004

INTRODUCTION

Liver transplantation is the accepted standard of care for patients with hepatocellular carcinoma, decompensated liver cirrhosis, and acute liver failure. Since the first liver transplant done in Singapore in 1990, results have been improving. We review the overall results of liver transplantation over the last 15 years.

METHODS

All transplant cases from 1990 to 2004 were reviewed retrospectively.

RESULTS

100 liver transplants were performed over the last 15 years; four in the first five years and 96 in the subsequent ten years. Overall one- and five-year survival rates were 80 percent and 78 percent, respectively. 44 were paediatric transplants, of which biliary atresia was the commonest indication for paediatric transplant. 56 were adult transplants of which hepatocellular carcinoma and decompensated hepatitis B cirrhosis were the commonest indications for adult transplant. Infection remained the commonest cause of mortality.

CONCLUSION

The number of transplants carried out per year was small due to the low cadaveric donation rate, but the survival of liver transplant patients was comparable to well-established liver transplant centres.

Long-term results of liver transplant in patients with chronic viral hepatitis-related liver disease in Singapore

INTRODUCTION

Liver disease from chronic hepatitis B (CHB) and C (CHC) constitutes 57 percent of adult liver transplant in Singapore. Their long-term results post-transplant may be affected by recurrence of the viral illness. This study aims to evaluate the long-term results and survival in patients transplanted for CHB- and CHC-related liver disease.

METHODS

Patients transplanted for CHB- and CHC-related disease from 1990 until March 2004, which included decompensated cirrhosis and hepatocellular carcinoma (HCC), were reviewed and analysed.

RESULTS

25 patients were transplanted for CHB-related liver disease, with mean follow-up of 153 +/- 25 weeks. Two- and four-year survival rates were 75 percent and 69 percent, respectively. Hepatitis B recurrence from YMDD mutants occurred in five patients, and four were treated successfully with adefovir dipivoxil, with resolution in transaminases and/or improvement in histology. One patient became non-compliant with follow-up and medications, and died 173 weeks post-transplant from reactivation of the wild-type hepatitis B virus. Nine patients were transplanted for CHC-related liver disease, with mean follow-up of 188 +/- 40 weeks, and two- and four-year survival rates of 89 percent and 76 percent, respectively. Two patients developed hepatitis C recurrence and were treated with interferon and ribavarin. One responded with sustained response but the other remained viraemic and died of HCC recurrence two years post-transplant.

CONCLUSION

Long-term results from CHB- and CHC-related liver diseases were satisfactory and comparable to major transplant centres in the USA and Europe. Recurrence of viral hepatitis post-transplant is controllable with current antiviral therapy.

Fatal bacteraemic pneumonia due to community-acquired methicillin-resistant Staphylococcus aureus

The recent worldwide surge in the incidence of fatal pneumonia caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has generated renewed interest in this well-known organism. We describe two cases of fulminant bacteraemic pneumonia due to CA-MRSA at the National University Hospital in Singapore and provide further epidemiological descriptors of this potentially-deadly disease. The first patient was an 83-year-old woman while the second was a 71-year-old man, none of whom had risk factors for hospital-acquired MRSA colonisation. Clinicians should be aware of the possibility of severe community-acquired pneumonia caused by this organism. Adequate empirical antimicrobial coverage for this important pathogen should be considered.

CT colonography in a Korean population with a high residue diet: Comparison between wet and dry preparations

AIM

To compare wet and dry preparation methods for computed tomography colonography (CTC) in terms of preparation quality, interpretation time, and diagnostic performance for polyp detection in a population with a high residue diet.

MATERIALS AND METHODS

Eighty-six patients were divided into two groups. Group 1 (n=24) received a wet preparation of 4l polyethylene glycol (PEG) solution, and group 2 (n=62) received a dry preparation of phosphor-soda. Abnormal findings, including polyps, and the time required to interpret the CTC images in both groups were documented by a radiologist. CTC findings were compared to those of colonoscopy as a reference standard. Two radiologists evaluated the quality of CTC with regard to residual fluid, faeces, and colonic distension using a four-point scale in consensus. Statistical differences for residual fluid, faeces, distensibility on CTC, and interpretation time between the two groups were analysed. The diagnostic performance of CTC in both groups was also compared.

RESULTS

One-hundred and ninety polyps in 70 patients were identified using colonoscopy. Regarding the quality of images produced the wet preparation was significantly better than the dry preparation (p<0.05). The average interpretation time was significantly shorter for the wet group (11.7 min) than the dry group (16.4 min) (p<0.05). For per-patient analysis, the positive predictive value (PPV) was significantly better for the wet (100%) than the dry group (79.6%; p=0.025). Sensitivities and PPV for >or=10 mm polyps were comparable between two groups (p>0.05).

CONCLUSION

In a population with a high-residue diet, CTC with wet preparation can be interpreted in a time-efficient manner and is comparable with CTC with dry preparation.

Total knee arthroplasty without patellar resurfacing

One hundred and eleven total knee replacements without patellar resurfacing were followed-up for a minimum of 48.8 months (range 48.8-108.2 months; average 78.2 months). Evaluation was performed using the Knee Society Clinical Rating System (KS-CRS). Preoperatively, the mean knee score was 34.3 points and the mean function score was 42.2 points. Postoperatively, this knee score improved to a mean of 91.1 points and the function score improved to mean of 89.6 points at the most recent follow-up. There were no significant differences among the knees with mild, moderate, or severe degenerative change to the patella with regard to the preoperative (p=0.83) and postoperative (p=0.39) knee pain score. It seems likely that the postoperative knee pain is not related to the severity of degenerative change to the patella in total knee arthroplasties performed without patellar resurfacing, and none of those patients required patellar resurfacing to achieve knee pain relief.

Deafferentation-disconnection neglect induced by posterior cerebral artery infarction

OBJECTIVE

To investigate patients with posterior cerebral artery (PCA) infarctions to learn whether hemispatial neglect is more frequent and severe after right than left PCA infarction; whether visual field defects (VFDs) influence the presence or severity of hemispatial neglect; and the anatomic loci of lesions that are associated with hemispatial neglect.

METHODS

The authors recruited 45 patients with PCA infarction that involved only the occipital lobe or the occipital lobe plus other areas served by the PCA. All subjects received seven neglect tests within 2 months after onset.

RESULTS

Overall, the frequency of hemispatial neglect was 42.2%. The frequency did not significantly differ between the right (48.0%) and left (35.0%) PCA groups, but the severity of hemispatial neglect was significantly greater in the right group. VFD alone did not influence the frequency or severity of neglect after controlling other variables. Isolated occipital lesions were rarely associated with hemispatial neglect, and it was only the occipital plus splenial lesion that significantly influenced the frequency and severity of neglect.

CONCLUSIONS

This study suggests that after excluding such confounding factors as aphasia or hemiplegia, neglect frequency does not differ between the right and left posterior cerebral artery (PCA) groups, but the severity of neglect is greater after right PCA infarctions; even in the acute stage of PCA infarction; visual field defect from an isolated occipital lesion does not cause hemispatial neglect; and the injury to both the occipital lobe and the splenium of the corpus callosum is important for producing hemispatial neglect with PCA infarction.

Sleep-related nocturnal erections and erections during midazolam-induced sedation in healthy young men

This study was performed to evaluate the characteristics of penile erection during midazolam-induced sedation after nocturnal sleep deprivation (NSD) and to determine the effect of NSD on erectile episodes in healthy, sexually functional young men. This procedure might possibly prove to be a brief office-based method of assessing whether erectile dysfunction is psychogenic or biogenic. Nineteen volunteers between the ages of 20 and 29 years participated in this study. We measured the morning penile erection after midazolam (3-5 mg) administration intravenously and all subjects completed 42 tests. Of 42 test, 28 tests revealed erectile episodes, whereas no erectile episodes were observed in 14 tests. Nocturnal sleep deprivation rate was significantly higher in tests with erectile episodes than in tests without erectile episode (P=0.030). Test order or duration of test was not different between two test results. Number of erectile episodes (r=0.374, P=0.015), tip radial rigidity (r=0.412, P=0.007), base radial rigidity (r=0.366, P=0.017) and tip tumescence (r=0.447, P=0.003) correlated with the degree of NSD. When we determined whether NSD was discriminative with regard to erectile episodes, the area under the receiver operating characteristic curve was calculated at 0.705 (95% confidence interval, 0.527-0.883; P=0.032) for the possibility of erectile episodes. Nocturnal sleep deprivation might recover the inhibited rapid eye movement sleep during midazolam-induced sedation. Our findings suggest that erection monitoring during midazolam-induced sedation after NSD may be convenient. However, validation of midazolam-induced morning penile tumescence monitoring with a large population is mandatory.

Anti-endothelial cell antibodies and antiphospholipid antibodies in Takayasu's arteritis: correlations of their titers and isotype distributions with disease activity

OBJECTIVE

To investigate the prevalence of anti-endothelial cell antibodies (AECA) and antiphospholipid antibodies, and the correlations of their isotype distributions and titers with disease activity in patients with Takayasu's arteritis (TA).

METHODS

Forty-seven patients with TA and 30 age- and sex-matched controls were studied. Blood samples were obtained from all patients and they were divided into either active or stable disease groups. Paired samples were available in 18 patients at both active and stable stage, respectively. AECA against human umbilical vein endothelial cells and antiphospholipid antibodies were measured.

RESULTS

Forty-two (89.4%) TA patients had AECA, and positivity rates of IgM and IgG AECA were 83.0% and 68.1%, respectively, while those for controls were both 3.3%. The titers of IgM and IgG AECA in patients were significantly higher than those in controls. IgM AECA titers of the active group were significantly higher than those of the stable group, but IgG AECA titers were not. In 18 patients with paired samples, IgM AECA titers at active stage were significantly higher than those at stable stage, but IgG AECA titers were not different between stages. The changes of IgM AECA titers correlated well with those of ESR levels between stages. Antiphospholipid antibodies were detected in only 4 patients with TA, but not in controls.

CONCLUSION

IgM AECA and IgG AECA were more prevalent and their titers were higher in patients with TA than in controls, and IgM AECA titers correlated well with the disease activity of TA. Antiphospholipid antibodies were not found significant.

Brain activation by visual erotic stimuli in healthy middle aged males

The objective of the present study was to identify brain centers, whose activity changes are related to erotic visual stimuli in healthy, heterosexual, middle aged males. Ten heterosexual, right-handed males with normal sexual function were entered into the present study (mean age 52 years, range 46-55). All potential subjects were screened over 1 h interview, and were encouraged to fill out questionnaires including the Brief Male Sexual Function Inventory. All subjects with a history of sexual arousal disorder or erectile dysfunction were excluded. We performed functional brain magnetic resonance imaging (fMRI) in male volunteers when an alternatively combined erotic and nonerotic film was played for 14 min and 9 s. The major areas of activation associated with sexual arousal to visual stimuli were occipitotemporal area, anterior cingulate gyrus, insula, orbitofrontal cortex, caudate nucleus. However, hypothalamus and thalamus were not activated. We suggest that the nonactivation of hypothalamus and thalamus in middle aged males may be responsible for the lesser physiological arousal in response to the erotic visual stimuli.

Severe Sepsis and Septic Shock in Adult Patients: An Approach to Management and Future Trends

Severe sepsis is sepsis associated with acute organ dysfunction. Septic shock in turn, implies severe sepsis that has led to circulatory shock refractory to fluid resuscitation alone. The immediate approach to severe sepsis follows the ABCs of resuscitation: Airway, Breathing, and Circulation. Special emphasis on the circulation involves early goal-directed therapy, adequate fluid resuscitation, and vasopressor/inotropic support. Once the patient's cardiorespiratory status is stabilized, efforts must be directed at uncovering the source and empirically yet accurately treating the infective underpinnings of severe sepsis. Following that, each of the patient's other organ systems at risk needs to be addressed: Renal/metabolic, gastrointestinal, hematological, and endocrine. Novel treatments will target both the proinflammatory and procoagulation cascades of sepsis.

Basin hopping simulations for all-atom protein folding

We investigate different protocols of the basin hopping technique for de novo protein folding. Using the protein free-energy force field PFF01 we report the reproducible all-atom folding of the 20-amino-acid tryptophan-cage protein [Protein Data Bank (PDB) code: 112y] and of the recently discovered 26-amino-acid potassium channel blocker (PDB code: 1wqc), which exhibits an unusual fold. We find that simulations with increasing cycle length and random starting temperatures perform best in comparison with other parametrizations. The basin hopping technique emerges as a simple but very efficient and robust workhorse for all-atom protein folding.

Improved therapeutic outcomes of DLBCL after introduction of rituximab in Korean patients

The addition of rituximab to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) has been shown to improve the outcome in all age groups with newly diagnosed diffuse large B-cell lymphoma (DLBCL). We conducted a retrospective analysis to evaluate the impact of this combination therapy on DLBCL outcomes in Korea. From October 2001 to June 2004, newly diagnosed DLBCL patients in nine Korean institutes were included. All of these 81 patients were treated with three or more cycles of rituximab plus CHOP (R-CHOP) combination chemotherapy (R group), and followed for a minimum of 12 months. For comparison, a historical cohort of patients was used and analyzed for "Clinicopathologic characteristics of Korean non-Hodgkin's lymphomas (NHLs) based on Revised American Lymphoma (REAL) classification" in 1999. Among the 1,098 NHL patients, the data of 214 DLBCL patients, who were treated with CHOP chemotherapy in first-line, were analyzed (C group). We compared outcomes between the C group and the R group. A total of 295 patients were evaluated (C group, 214; R group, 81). The complete response (CR) rate was higher in R group (73 vs 91%, p=0.001). The 2-year event-free survival (EFS) rate was significantly higher in R group (78 vs 85%, p=0.0194). This survival benefit was maintained in high-risk patients according to the international prognostic index (IPI) (p=0.0039), regardless of age. However, there was no significant difference in low-risk patients. The addition of rituximab to CHOP combination chemotherapy for DLBCLs showed improved outcomes, particularly in high-risk group according to the IPI. Long-term follow-up results will be needed to confirm these results.

Effect of human mesenchymal stem cell transplantation combined with growth factor infusion in the repair of injured spinal cord

Recently, bone marrow stromal cells have been shown to have the capacity to differentiate into neural cell under experimental cell culture conditions. Some investigators suppose that these cells, when placed into an environment of injury, express factors that promote repair or active compensatory mechanisms and endogeneous stem cells within the injured tissue. Rats were subjected to a weight driven implant spinal cord injury. After one week, the rats were treated with cultured human mesenchymal stem cells (MSCs) transplantation and basic fibroblast growth factor (bFGF) infusion into the CSF space. Functional outcome and histologic evaluation were performed. The data showed improved functional outcome in the group treated with MSCs transplantation and bFGF administration compared with the group of MSCs transplantation and control, which means bFGF might take an additional role to improve functional outcome. Glial differentiation of MSCs was noted but neuronal differentiation was doubtful. In this study, we did not demonstrate the mechanism of the neurotrophic factor affecting neural repair. However, this study is consistent with growing literature that MSCs and neurotrophic factor promote tissue repair and functional recovery after spinal cord injury and suggests that MSCs transplantation and bFGF warrants investigation as a therapeutic intervention after spinal cord injury.

The behavioral effect of human mesenchymal stem cell transplantation in cold brain injured rats

We investigated the effect of stereotaxically transplanted human mesenchymal stem cells (hMSCs) on behavioral change after traumatic cold brain injury in adult rats. Cortical lesions (n= 20) were induced by touching a metal stamp, cooled with liquid nitrogen, to the dura over the forelimb motor cortex of adult rats. The procedure produced a localized lesion, and the animals showed significant motor deficits. hMSCs were freshly isolated from human iliac bone and cultured in tissue culture flasks with 10 ml Dulbecco's modified Eagle's medium. The animals received hMSC grafts (3 x 10(5) hMSCs) 6 days after cold lesion (n = 10). All rats were sacrificed 3 or 7 weeks after cold injury, and immunohistochemical staining was performed on brain sections to identify donor hMSCs. Neurological evaluations were performed with the forepaw adjusting step test and modified neurological scoring. Treatment with 3 x 10(5) hMSCs improved the rat's neurological functions. We also found that the transplanted cells successfully migrated into the injured brain, preferentially localized around the injury site, and expressed the neuronal and astrocyte marker. These data suggest that hMSCs may be a potential therapeutic tool for brain injuries.

Asthma attack associated with oxidative stress by exposure to ETS and PAH

Asthma is primarily an airways inflammatory disease, and the bronchial airways have been shown to be particularly susceptible to oxidant-induced tissue damage.

OBJECTIVE

The purpose of this study was to investigate whether pulmonary inflammation in asthma is associated with exposure to environmental oxidants such as polycyclic aromatic hydrocarbon (PAH) and environmental tobacco smoke (ETS).

METHOD

We assessed the exposure level of PAH and ETS by using urinary 1-hydroxypyrene glucuronide (1-OHPG) and cotinine. We estimated oxidative damage and inflammatory cytokine levels from 16 asthma patients and 16 patients in stable conditions 1 to 2 months later.

RESULTS

Our study showed that the levels of oxidative damage, as measured by malondialdehyde (MDA), were significantly increased (p = 0.006) during the asthma attacks. Proinflammatory and anti-inflammatory cytokines were both increased during the asthma attacks compared to the stable conditions at follow-up. Interleukin (IL-6) and IL-10 were especially increased significantly (p = 0.015 and p < 0.001, respectively). Correlations were observed between inflammatory cytokines such as IL-6 and IL-1beta (p = 0.034).

CONCLUSION

This study supports the results of in vitro studies that oxidative stress, specifically lipid peroxidation, contributes to the pathophysiology of asthma. Therefore, environmental interventions based on this better understanding are needed to significantly reduce oxidant stress and prevent or minimize the development of asthmatic symptoms.

The statistical mechanics of complex signaling networks: nerve growth factor signaling

The inherent complexity of cellular signaling networks and their importance to a wide range of cellular functions necessitates the development of modeling methods that can be applied toward making predictions and highlighting the appropriate experiments to test our understanding of how these systems are designed and function. We use methods of statistical mechanics to extract useful predictions for complex cellular signaling networks. A key difficulty with signaling models is that, while significant effort is being made to experimentally measure the rate constants for individual steps in these networks, many of the parameters required to describe their behavior remain unknown or at best represent estimates. To establish the usefulness of our approach, we have applied our methods toward modeling the nerve growth factor (NGF)-induced differentiation of neuronal cells. In particular, we study the actions of NGF and mitogenic epidermal growth factor (EGF) in rat pheochromocytoma (PC12) cells. Through a network of intermediate signaling proteins, each of these growth factors stimulates extracellular regulated kinase (Erk) phosphorylation with distinct dynamical profiles. Using our modeling approach, we are able to predict the influence of specific signaling modules in determining the integrated cellular response to the two growth factors. Our methods also raise some interesting insights into the design and possible evolution of cellular systems, highlighting an inherent property of these systems that we call 'sloppiness.'

Treatment of steroid-resistant acute liver transplant rejection with basiliximab

Current rescue therapies for acute steroid-resistant rejection, such as OKT3 and high-dose tacrolimus, are not uncommonly associated with side effects that contribute to significant morbidity of the patient. Basiliximab is a chimeric monoclonal antibody that acts as an interleukin-2 receptor antagonist on the surface of activated T lymphocytes. It has until now only been used as immunoprophylaxis in adult liver transplant patients. In this report, we describe the use of Basiliximab as rescue therapy in a case of acute steroid-resistant rejection in an adult living related liver transplant recipient.

Hyaline Cartilage Regeneration Using Mixed Human Chondrocytes and Transforming Growth Factor-β1- Producing Chondrocytes

The purpose of this study was to investigate the efficacy of cartilage regeneration when using a mixture of transforming growth factor-beta1 (TGF-beta1)-producing human chondrocytes (hChon-TGF-beta1) and primary human chondrocytes (hChon) ("mixed cells"), compared with either hChon-TGF-beta1 or hChon cells alone. Specifically, mixed cells or hChon cells were first injected intradermally into the backs of immune-deficient nude mice to test the feasibility of cartilage formation in vivo. Both the mixed cells and the hChon-TGF-beta1 cells alone induced cartilage formation in nude mice, whereas hChon cells alone did not. To further test the efficacy of the cells in generating cartilage, an artificially induced partial thickness defect of the femoral condyle of a rabbit knee joint was loaded with hChon-TGF-beta1 cells with or without mixing additional untransduced hChon cells, and hyaline cartilage regeneration was observed at 4 or 6 weeks. The efficiency of complete filling of the defect and the quality of tissue generated after implanting were evaluated on the basis of a histological grading system modified from O'Driscoll et al. (J. Bone Joint Surg. 70A, 595, 1988). Significantly, mixed cells (14.2 +/- 0.9) produced significantly better results than hChon-TGF-beta1 (9.0 +/- 1.7) or hChon (8.0 +/- 1.8) cells alone. Histological and immunohistochemical staining of the newly repaired tissues produced after treatment with either mixed cells or hChon-TGF-beta1 cells alone showed hyaline cartilage- like characteristics. These results suggest that the implantation of mixed cells may be a clinically efficient method of regenerating hyaline articular cartilage.

Genetic polymorphisms of OPG, RANK, and ESR1 and bone mineral density in Korean postmenopausal women

To evaluate the effects of genetic polymorphisms of OPG, RANK, and ESR1, which regulate osteoclastogenesis, on bone mineral density (BMD), a cross-sectional study was conducted in 650 Korean postmenopausal women. BMDs of the distal radius and the calcaneus were measured by dual energy X-ray absorptiometry (DXA). Genetic polymorphisms of OPG 163 A > G, 1181 G > C; RANK 421 C > T, 575 T > C; and ESR1 1335 C > T, 2142 G > A were determined by matrix-assisted laser desorption/ionization-time of flight (MALDI-ToF) mass spectrometry. The differences between the BMDs of the genotypes of OPG, RANK, and ESR1 were analyzed by multiple linear regression model adjusted for age and body mass index. Women with the OPG 1181 CC genotype had higher BMDs at the distal radius (7%) and calcaneus (10%) than those with the GG genotype; and these differences were statistically significant (P = 0.001 and P = 0.007, respectively). A significant association was also observed between RANK 575 T > C and calcaneus BMD (P for trend = 0.017). No significant association was observed between BMDs and the polymorphisms of ESR1. The association between OPG 1181 G > C and BMD was profound in subjects with the RANK 575 TT or ESR1 2142 GG genotypes; women with OPG 1181 CC had higher BMDs at the distal radius (11%) and calcaneus (11%) than those with OPG 1181 GG only in women with RANK 575 TT genotype (P = 0.002 and P = 0.021, respectively). These results suggest that OPG genetic polymorphisms, especially with the RANK 575 TT or ESR1 2142 GG genotypes, are related to low BMD in postmenopausal Korean women.

Role of combined modality treatment of buccal mucosa squamous cell carcinoma

BACKGROUND

Squamous cell carcinoma of the buccal mucosa is an oral cancer reported as having a poor prognosis. In many patients combined modality treatment incorporating surgery and adjuvant radiotherapy should be considered best practice.

METHODS

Patients treated for buccal mucosa squamous cell carcinoma were identified through the computer database in the Department of Radiation Oncology, Westmead Hospital, Sydney. All eligible patients were treated with curative intent. Survival was calculated using the Kaplan-Meier product limit method.

RESULTS

A total of 32 eligible patients were identified. There were 20 males and 12 females. Median age at diagnosis was 67 years (range 44-82 years). Median duration of follow-up was 42 months (6-205 months). More than half (59 per cent) presented with early stage disease (stage I/II) with 35 per cent presenting with advanced (stage III/IV) disease. Most patients (28/32; 88 per cent) underwent surgery with eight patients also undergoing adjuvant radiotherapy. Four patients underwent definitive radiotherapy alone. A total of 15/32 (47 per cent) patients developed recurrence: four locally, eight regionally and three with locoregional recurrence. Patients treated with surgery and adjuvant radiotherapy had the lowest rate of recurrence. Median time to recurrence was five months. The three-year overall and disease free survival was 55 and 47 per cent, respectively.

CONCLUSION

Buccal mucosa squamous cell carcinoma is an aggressive squamous cell carcinoma of the oral cavity. Despite treatment patients remain at risk of locoregional recurrence especially in the untreated ipsilateral neck. In many cases patients will benefit from multimodality treatment.

Complete sequence and structure of the mitochondrial genome of the human tapeworm, Taenia asiatica (Platyhelminthes; Cestoda)

The complete Taenia asiatica mitochondrial genome was amplified by long extension polymerase chain reaction (long PCR) to yield overlapping fragments that were then completely sequenced. The whole mitochondrial genome was 13 703 bp long and contained 12 protein-encoding, 2 ribosomal RNA (small and large subunits), 22 transfer RNA genes and a short non-coding region. Thus, its gene contents are like those typically found in metazoan animal mitochondrial genomes (apart from the absence of atp8). All the genes were transcribed from the same strand. The 3' end 34 bp region of nad4L overlapped with the 5' end portion of nad4. The tRNA genes were 61-69 bp long, and the secondary structures of 18 tRNAs had typical clover-leaf shapes with paired DHU arms. However, trnC, trnS1, trnS2 and trnR had unpaired DHU arms that were 7-12 bp in length. The tRNAs that transferred serine lacked a DHU arm, as is also observed in a number of parasitic platyhelminths and metazoans. However, the trematode trnRs have paired DHU arms. The T. asiatica mtDNA non-coding region was like that in other cestodes since it was composed of a short non-coding region of 72 nucleotides and a long non-coding region of 176 nucleotides separated by a trnL1/, trnS2/, trnL2/, trnR/, nad5 gene cluster. The sequences of the cox1 genes between T. asiatica and T. saginata differ by 4.6%, while the T. asiatica cob gene differs by 4.1% and 12.9% from the cob genes of T. saginata and T. solium, respectively. In conclusion, the T. asiatica mitocondrial genome should provide a resource for comparative mitochondrial genomics and systematic studies of parasitic cestodes.

Continuous transforming growth factor beta1 secretion by cell-mediated gene therapy maintains chondrocyte redifferentiation

One of the most important factors in the production of cartilage is transforming growth factor beta1 (TGF-beta1). To obtain sustained release of TGF-beta1, a cell-mediated gene therapy technique was introduced. We infected chondrocytes with a retroviral vector carrying the TGF-beta1 gene. The single clone derivative showed sustained TGF-beta1 secretion. It also showed constitutive type II collagen expression. Whereas the TGF-beta1 protein itself is unable to induce formation of cartilage in vivo, human chondrocytes engineered to express a retroviral vector encoding TGF-beta1 showed cartilage formation in vivo when cells were injected into nude mice intradermally. These data suggest that cell-mediated gene therapy using TGF-beta1 as a transgene would be a promising treatment for osteoarthritis.

Retroviral gene therapy: safety issues and possible solutions

The recent incidents of leukemia development in X-SCID patients after a successful treatment of the disease with retroviral gene therapy raised concerns regarding the safety of the use of retroviral vectors in clinical gene therapy. In this review, we have tried to re-evaluate the safety issues related to the use of retroviral vectors in human clinical trials and to suggest possible appropriate solutions to the issues. As revealed by the X-SCID incident, oncogenesis caused by retroviral insertional activation of host genes is one of the most prominent risks. An ultimate solution to this problem will be in re-engineering retroviral vectors so that the retroviral insertion takes place only at the desired specific sites of the host cell chromosome. This is, however, a technically demanding tasks, and it will take years to develop retroviral vectors with targeted insertion capability. In the mean time, the use of chromatin insulators can reduce chances for retrovirus-mediated oncogenesis by inhibiting non-specific activation of nearby cellular proto-oncogenes. Co-transduction of a suicidal gene under the control of an inducible promoter could also be one of the important safety features, since destruction of transduced cells can be triggered if abnormal growth is observed. Additionally, conditional expression of the transgene only in appropriate target cells via the combination of targeted transduction, cell type-specific expression, and targeted local administration will increase the overall safety of the retroviral systems. Finally, splitting of the viral genome, use of self-inactivating (SIN) retroviral vectors, or complete removal of the coding sequences for gag, pol, and env genes is desirable to virtually eliminate the possibility of generation of replication competent retroviruses (RCR).

Glucose metabolism in early onset versus late onset Alzheimer's disease: an SPM analysis of 120 patients

The aims of this cross-sectional study were (i) to compare the overall glucose metabolism between early onset and late onset Alzheimer's disease in a large sample of patients; and (ii) to investigate the pattern of glucose metabolism as a function of dementia severity in early onset versus late onset Alzheimer's disease, using a statistical parametric mapping (SPM) analysis. Subjects consisted of four groups: 74 patients with early onset Alzheimer's disease, 46 patients with late onset of the disease, and two control groups age matched to each patient group. All the subjects underwent 2-[(18)F]fluoro-2-deoxy-d-glucose (FDG)-PET under the same scanning conditions. Severity of dementia was rated with the Clincial Dementia Rating (CDR). Voxel-based SPM99 was used for statistical analyses. Overall glucose hypometabolism of early onset Alzheimer's disease patients was much greater in magnitude and extent than that of late onset patients, though both groups were similar in dementia severity: the early onset group showed more severe hypometabolism in parietal, frontal and subcortical (basal ganglia and thalamus) areas. When the decline of glucose metabolism was compared as a function of CDR stage, the slope was steeper in early onset than in late onset Alzheimer's disease. The rapid decline occurred at CDR 0.5-1 in the early onset group, whereas similar changes occurred at CDR 2-3 in the late onset group. The greater hypometabolism in early onset than in late onset patients is required to reach the same severity of dementia, probably reflecting greater functional reserve in younger than in older subjects. Alternatively, the metabolic decline curve suggests that the early onset patients may take a more rapid course in the reduction of glucose metabolism than the late onset patients.

Successful listing of patients for liver transplant was related to participation of referring doctor in the transplant program

INTRODUCTION

Experience with liver transplantation is limited in many parts of Asia. Therefore, patients from nontransplant centers may not be referred in a timely fashion for transplants. Our aim was to evaluate the pattern of referral for liver transplantation and their outcomes in Singapore.

METHODS

Consecutive patients referred from 1990 to 2001 were reviewed. Patients from any hospital in Singapore (or the region) could be referred to the program. They were discussed at the weekly meetings. Appropriate patients were placed on the waiting list. "Pending" indicated that the disease was early or there were unsettled medical or social issues. Unsuitable patients were "rejected" for transplant.

RESULTS

There were 385 patients referred over a 12-year period. Hepatitis B cirrhosis and hepatocellular carcinoma (HCC) were the most common indications among adults, whereas biliary atresia was the most common for children. Pediatric patients were more likely than adult patients to be listed for transplant (53/76 vs 106/309, P < .001). Patients referred by regular attendees of the program were more likely to be accepted than nonattendees (38% vs 25%, P = .04). "Disease too early", "advanced HCC", and "refusal by family members" were the most common reasons for rejection.

CONCLUSION

Members of the Liver Transplant Program were more likely to refer suitable patients for transplant at the appropriate time. Better interaction between gastroenterologists inside and outside the transplant program would help to improve the timing of referrals for liver transplantation, and hence, patient survival.