Amyloid-ß(1-42) oligomer accelerates senescence in adult hippocampal neural stem/progenitor cells via formylpeptide receptor 2.

The failure of adult hippocampal neurogenesis is increasingly considered as an important factor in the pathological correlates for memory decline in Alzheimer's disease (AD). Loss of adult-born neurons and abnormalities of neural stem/progenitor cells (NSPCs) within the dentate gyrus (DG) of adult hippocampus might contribute to this process. In this study, we showed that amyloid-ß(1-42) (Aß42) oligomer triggers senescent phenotype of NSPCs in vitro. Oligomerized Aß42 induced the production of senescence-associated biomarkers p16 and senescence-associated ß-galactosidase (SA-ß-gal) in adult mouse hippocampal NSPCs, as well as inhibited cells proliferation and differentiation. In the DG of amyloid precursor protein/presenilin1 (APP/PS1) transgenic mice, the number of senescent NSPCs was significantly increased and senescence-associated protein p16 was upregulated. Formylpeptide receptor 2 (FPR2), one of Aß42 functional receptors, may be involved in NSPCs senescence. The FPR2 antagonist WRW4 significantly inhibited NSPCs senescence induced by Aß42. In addition, the activation of p38 mitogen-activated protein kinase (MAPK) in response to the accumulation of reactive oxygen species (ROS) was involved in NSPCs senescence induced by Aß42. WRW4 inhibited the accumulation of ROS and the activation of p38 MAPK in NSPCs. Our data suggest that Aß42 accelerates NSPCs senescence via FPR2-dependent activation of its downstream ROS-p38 MAPK signaling, which limits the function of NSPCs and contributes to failure of neurogenesis. This is the first demonstration of NSPCs senescence response to Aß42.

An unusual cause of obstructive jaundice.

Small-cell carcinomas of lung origin have been well characterised for their clinico-histopathological features. However, extrapulmonary small-cell carcinomas are rare, and in particular, they are extremely rare at the ampullary region. We report herein a case of small-cell carcinoma of ampulla of Vater and review its clinical, histological, and immunohistochemical features.

Hepatocarcinogenesis of regenerative and dysplastic nodules in Chinese patients.

OBJECTIVES: To determine the development rate of hepatocellular carcinoma and survival of patients diagnosed to have regenerative, and low-grade and high-grade dysplastic liver nodules. DESIGN: Retrospective descriptive study. SETTING: Acute public hospital, Hong Kong. PATIENTS: Patients with non-malignant liver nodules confirmed by imaging-guided liver biopsy between January 1997 and December 2008. MAIN OUTCOME MEASURES: Rates of hepatocellular carcinoma development and survival. RESULTS: A total of 147 patients with non-malignant liver nodules were followed up over a median duration of 29 months. The initial histological diagnosis included regenerative nodules (n=74), low-grade dysplastic nodules (n=34), and high-grade dysplastic nodules (n=39). The respective cumulative hepatocellular carcinoma development rate during the first, second, third, and fourth year were 3%, 5%, 9% and 12% for simple regenerative nodules, 29%, 35%, 38% and 44% for low-grade dysplastic nodules, and 38%, 41%, 51% and 51% for high-grade dysplastic nodules. The hepatocellular carcinoma development rate was highest in those with high-grade dysplastic nodules. Multivariate analysis showed that histological dysplastic changes were associated with increased alpha-fetoprotein levels and advanced age, which were both independent predictors of hepatocellular carcinoma development. Histological dysplastic changes, male sex, advanced age, prolonged prothrombin time, and ultrasound appearances were independent predictors of mortality. CONCLUSION: The presence of dysplastic change in liver nodules increased the risk of hepatocellular carcinoma development and death.

Ten-year review of epidemiology, clinical features, and treatment outcome of achalasia in a regional hospital in Hong Kong.

OBJECTIVE: To describe the epidemiology, clinical features, and treatment outcome of achalasia in Chinese patients. DESIGN: Retrospective study. SETTING: Major regional hospital, Hong Kong. PATIENTS: Clinical records of patients with the diagnosis of achalasia from July 1997 to June 2007 were reviewed. RESULTS: Thirty-two patients were diagnosed with achalasia during the study period. The mean age at diagnosis was 50 years (standard deviation, 20 years). The female-to-male ratio was 1.3:1. The main presenting symptoms were dysphagia (78%) and vomiting (50%). Nine laparoscopic and two open Heller's operations had been performed and 16 patients had undergone endoscopic dilatations. Four patients had botulinum toxin injection and four were taking calcium channel blocker (nifedipine) medications. Botulinum toxin injection and medical therapy had poor short- and long-term responses. Laparoscopic myotomy and pneumatic dilatation had comparable good short- and long-term responses. CONCLUSION: Achalasia affected all age-groups but there was a peak at middle age. Pneumatic dilatation and Heller's myotomy (open or laparoscopic approach) appeared able to maintain longer symptom responses than medical therapy and botulinum toxin injection.

Outcome of inoperable hepatocellular carcinoma patients receiving transarterial chemoembolisation: a real-life retrospective analysis in a Hong Kong regional hospital.

OBJECTIVE: To evaluate survival and prognostic factors in patients with advanced hepatocellular carcinoma treated by transarterial chemoembolisation in a real-life clinical practice setting. DESIGN: Retrospective study. SETTING: Regional hospital, Hong Kong. PATIENTS: Patients with inoperable hepatocellular carcinoma diagnosed from January 1998 to December 2003 who received transarterial chemoembolisation. RESULTS: A total of 74 patients were identified, and had a median survival of 214 days. The cumulative survival rates at 1, 2, and 3 years were 28%, 12%, and 7%, respectively. By multivariate analysis, superselective cannulation performed in transarterial chemoembolisation (hazard ratio=0.47; 95% confidence interval, 0.23-0.95; P=0.034), embolisation with gelfoam (0.30; 0.11-0.80; P=0.017), and treatment intervals of more than 45 days (0.33; 0.15-0.72; P=0.006) were independent predictors of good survival. Child-Pugh grade B cirrhosis (hazard ratio=5.62; 95% confidence interval, 2.11-14.97; P=0.001), and high pre-treatment serum alpha-fetoprotein level (2.93; 1.50-5.73; P=0.002) were independent predictors of poor survival. CONCLUSIONS: In real-life clinical practice, survival of patients with inoperable hepatocellular carcinoma remains grave despite treatment. Patients with Child-Pugh grade A cirrhosis or with low pretreatment alpha-fetoprotein level are more suitable for this form of treatment. The procedure should be performed with superselective cannulation and embolisation with gelfoam.

The epidemiology and clinical characteristics of Crohn's disease in the Hong Kong Chinese population: experiences from a regional hospital.

OBJECTIVE: To study the descriptive epidemiology and clinical profile of patients with Crohn's disease. DESIGN: Retrospective study. SETTING: Regional hospital, Hong Kong. PATIENTS: Patients with Crohn's disease diagnosed between January 1991 and December 2006 inclusive. RESULTS: Over the period studied, 27 Chinese patients were diagnosed with Crohn's disease in our hospital. Our hospital-based incidence and prevalence rate had increased more than 2- and 5-fold, respectively over that period. The mean age at diagnosis was 26 years and median duration of disease was 81 months. Most patients had ileocolonic disease (67%) followed by Crohn's colitis (22%) and ileal disease (11%); more patients had non-stricturing and non-penetrating disease (63%) than stricturing (15%) or penetrating disease (22%). Peri-anal disease occurred in 37% of our patients. At diagnosis, many of the patients (41%) had mild-moderate disease, but 30% each had moderate-severe and severe-fulminant disease. At the time of this study, 85% of the patients were in disease remission with medical treatment. However, 48% had undergone surgery for diagnosis or complications. No patient had developed colorectal cancer or died. CONCLUSIONS: The incidence and prevalence of Crohn's disease are increasing in the Chinese population. It usually affects young persons with a substantial proportion of patients presented with severe-fulminant disease. More epidemiological and clinical studies are needed for this emerging disease in Asian regions.

Value of Mycobacterium tuberculosis fingerprinting as a tool in a rural state surveillance program.

OBJECTIVE: This study demonstrates the value of Mycobacterium tuberculosis fingerprinting used in conjunction with traditional epidemiologic methods to identify smoldering outbreaks of tuberculosis in endemic areas where background rates of tuberculosis are high. METHODS: IS6110 DNA fingerprinting was performed on isolates of M tuberculosis from verified cases of tuberculosis in Alabama from 1994 to 1998. A statewide database groups isolates into "clusters" and tracks them cumulatively over time. A large cluster was identified and was secondarily investigated using traditional epidemiologic methods. RESULTS: Twenty-five isolates were found to be identical by fingerprinting analysis. Patients were living within 10 counties across the state, and 12 cases were localized to a single county. This represented an ongoing, statewide tuberculosis outbreak previously unrecognized by local and state health officials. Secondary investigation of the cases revealed the primary sites of transmission to be a correctional facility and two homeless shelters. CONCLUSIONS: Population surveillance using M tuberculosis fingerprinting was successfully utilized to detect a significant and smoldering tuberculosis outbreak. Measures are currently in place to identify and prevent further transmission in the involved locations.

Identification of a contaminating Mycobacterium tuberculosis strain with a transposition of an IS6110 insertion element resulting in an altered spoligotype.

Molecular fingerprinting with the IS6110 insertion sequence is useful for tracking transmission of Mycobacterium tuberculosis within a population or confirming specimen contamination in the laboratory or through instrumentation. Secondary typing with other molecular methods yields additional information as to the relatedness of strains with similar IS6110 fingerprints. Isolated, relatively rare, random events within the M. tuberculosis genome alter molecular fingerprinting patterns with any of the methods; therefore, strains which are different by two or more typing methods are usually not considered to be closely related. In this report, we describe two strains of M. tuberculosis, obtained from the same bronchoscope 2 days apart, that demonstrated unique molecular fingerprinting patterns by two different typing methods. They were closely linked through the bronchoscope by a traditional epidemiologic investigation. Genetic analysis of the two strains revealed that a single event, the transposition of an IS6110 insertion sequence in one of the strains, accounted for both the differences in the IS6110 pattern and the apparent deletion of a spacer in the spoligotype. This finding shows that a single event can change the molecular fingerprint of a strain in two different molecular typing systems, and thus, molecular typing cannot be the only means used to track transmission of this organism through a population. Traditional epidemiologic techniques are a necessary complement to molecular fingerprinting so that radical changes within the fingerprint pattern can be identified.

Spot sputum screening: evaluation of an intervention in two homeless shelters.

SETTING: Two homeless shelters in Birmingham, Alabama. OBJECTIVE: To interrupt tuberculosis transmission and evaluate the utility of spot sputum screening. DESIGN: Two shelters participated in the study between May 1996 and February 1997. A spot sputum specimen was collected on a given evening from each overnight client. Information was obtained regarding symptoms and tuberculin skin test (TST) status. There were four screenings during two rounds, with TST in round one only. RESULTS: Of 127 persons involved in the study, 120 (95%) provided specimens, and four tuberculosis cases were identified (4/127, 3.1%). Symptoms were infrequently reported. RFLP analysis (IS6110) confirmed a two-band cluster in three of the four cases; another matching two-band strain was found in a drug rehabilitation client staying in one shelter. Secondary RFLP typing (pTBN12) confirmed the homeless cluster. Costs were $1311 per case identified. Among 92 clients with a prior TST, 40% reported a positive result (37/92). Of 21 PPD tests read, 11 were > or =10 mm (52%). CONCLUSION: Spot sputum screening is effective in identifying unsuspected tuberculosis cases in shelters. It has acceptable costs, is logistically simple and efficient. Symptom screening was not useful in this general homeless population. RFLP analysis showed cloning of the two-band strain. Given the evidence for ongoing transmission, sputum screening should be considered in shelter settings.

Restriction fragment length polymorphism screening of Mycobacterium tuberculosis isolates: population surveillance for targeting disease transmission in a community.

SETTING: Alabama State Tuberculosis Control Program, USA. OBJECTIVE: To combine molecular screening data with routine information to assess transmission of Mycobacterium tuberculosis and improve control efforts. DESIGN: Since January 1994, samples from tuberculosis cases statewide have been systematically analyzed by IS6110 restriction fragment length polymorphism (RFLP). All cases during 1994-1995 with a predominate RFLP pattern were evaluated and risk factors assessed. pTBN12 was used to evaluate a large cluster in the Birmingham-Jefferson County (BJC) area. RESULTS: Statewide, a common two-band pattern was found, named JH2 (99/566, 17.5%). The most important risk associated with this pattern was homelessness (odds ratio, 8.9; P < 0.001). In the BJC area, the homeless accounted for 29% (51/175) of new cases diagnosed during the study period. For the BJC homeless, there were 13 unique RFLP patterns, and JH2 was predominant (29/33, 88%) among three clusters. Secondary analysis of the homeless JH2 cluster revealed a large group that included 19 of 24 (79%) isolates analyzed. Compared with the BJC non homeless (n = 124), the homeless were younger (P < 0.001), of male gender (P < 0.001), black race (P = 0.002), and were heavy alcohol (P < 0.001) and non-injection drug (P = 0.001) users. CONCLUSIONS: By screening tuberculosis cases statewide, a common two-band RFLP pattern was identified. Its predominance is explained by an ongoing tuberculosis epidemic among Birmingham's homeless population, highlighting RFLP as a tool for population surveillance. The pattern differences observed by pTBN12 typing clearly demonstrate that the isolates might be related but are not clonal.