Synthesis and Structure-Activity Relationships of Inhibitors That Target the C-Terminal MEEVD on Heat Shock Protein 90.

Herein, we describe the synthesis and structure-activity relationships of cyclic peptides designed to target heat shock protein 90 (Hsp90). Generating 19 compounds and evaluating their binding affinity reveals that increasing electrostatic interactions allows the compounds to bind more effectively with Hsp90 compared to the lead structure. Exchanging specific residues for lysine improves binding affinity for Hsp90, indicating some residues are not critical for interacting with the target, whereas others are essential. Replacing l- for d-amino acids produced compounds with decreased binding affinity compared to the parent structure, confirming the importance of conformation and identifying key residues most important for binding. Thus, a specific conformation and electrostatic interactions are required in order for these inhibitors to bind to Hsp90.

Inverse relationship between body mass index and mortality in older nursing home residents: a meta-analysis of 19,538 elderly subjects.

Body mass index (BMI) and mortality in old adults from the general population have been related in a U-shaped or J-shaped curve. However, limited information is available for elderly nursing home populations, particularly about specific cause of death. A systematic PubMed/EMBASE/CINAHL/SCOPUS search until 31 May 2014 without language restrictions was conducted. As no published study reported mortality in standard BMI groups (<18.5, 18.5-24.9, 25-29.9, ≥30 kg/m(2)), the most adjusted hazard ratios (HRs) according to a pre-defined list of covariates were obtained from authors and pooled by random-effect model across each BMI category. Out of 342 hits, 20 studies including 19,538 older nursing home residents with 5,223 deaths during a median of 2 years of follow-up were meta-analysed. Compared with normal weight, all-cause mortality HRs were 1.41 (95% CI = 1.26-1.58) for underweight, 0.85 (95% CI = 0.73-0.99) for overweight and 0.74 (95% CI = 0.57-0.96) for obesity. Underweight was a risk factor for higher mortality caused by infections (HR = 1.65 [95% CI = 1.13-2.40]). RR results corroborated primary HR results, with additionally lower infection-related mortality in overweight and obese than in normal-weight individuals. Like in the general population, underweight is a risk factor for mortality in old nursing home residents. However, uniquely, not only overweight but also obesity is protective, which has relevant nutritional goal implications in this population/setting.

Hospital diagnostic aggregation and risk-adjusted quality.

OBJECTIVE: To demonstrate the importance of diagnostic aggregation when assessing hospitals. DATA SOURCES: Patient data from the Victorian Admitted Episodes Database (VAED), 1999/2000 to 2004/2005. Financial statements from public hospitals, 2002/2003 to 2004/2005. STUDY DESIGN: Risk-adjusted quality computed for each hospital using two aggregation levels. Each is then used to estimate the relationship between hospital efficiency and quality using two-stage DEA/Tobit model by Wilson and Simar (2006). DATA COLLECTION: Selected variables from the VAED were obtained from the Department of Health in Victoria, then linked anonymously with financial statements. PRINCIPAL FINDINGS: Hospital quality and, in some cases, its relationship with efficiency differs depending on aggregations. CONCLUSIONS: Patient risk adjustment should be conducted using more than one aggregation level whenever possible.

Novel ethyl methanesulfonate (EMS)-induced null alleles of the Drosophila homolog of LRRK2 reveal a crucial role in endolysosomal functions and autophagy in vivo.

Mutations in LRRK2 cause a dominantly inherited form of Parkinson's disease (PD) and are the most common known genetic determinant of PD. Inhibitor-based therapies targeting LRRK2 have emerged as a key therapeutic strategy in PD; thus, understanding the consequences of inhibiting the normal cellular functions of this protein is vital. Despite much interest, the physiological functions of LRRK2 remain unclear. Several recent studies have linked the toxicity caused by overexpression of pathogenic mutant forms of LRRK2 to defects in the endolysosomal and autophagy pathways, raising the question of whether endogenous LRRK2 might play a role in these processes. Here, we report the characterization of multiple novel ethyl methanesulfonate (EMS)-induced nonsense alleles in the Drosophila LRRK2 homolog, lrrk. Using these alleles, we show that lrrk loss-of-function causes striking defects in the endolysosomal and autophagy pathways, including the accumulation of markedly enlarged lysosomes that are laden with undigested contents, consistent with a defect in lysosomal degradation. lrrk loss-of-function also results in the accumulation of autophagosomes, as well as the presence of enlarged early endosomes laden with mono-ubiquitylated cargo proteins, suggesting an additional defect in lysosomal substrate delivery. Interestingly, the lysosomal abnormalities in these lrrk mutants can be suppressed by a constitutively active form of the small GTPase rab9, which promotes retromer-dependent recycling from late endosomes to the Golgi. Collectively, our data provides compelling evidence of a vital role for lrrk in lysosomal function and endolysosomal membrane transport in vivo, and suggests a link between lrrk and retromer-mediated endosomal recycling.

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.

Intravenous immunoglobulin suppresses NLRP1 and NLRP3 inflammasome-mediated neuronal death in ischemic stroke.

Multi-protein complexes called inflammasomes have recently been identified and shown to contribute to cell death in tissue injury. Intravenous immunoglobulin (IVIg) is an FDA-approved therapeutic modality used for various inflammatory diseases. The objective of this study is to investigate dynamic responses of the NLRP1 and NLRP3 inflammasomes in stroke and to determine whether the NLRP1 and NLRP3 inflammasomes can be targeted with IVIg for therapeutic intervention. Primary cortical neurons were subjected to glucose deprivation (GD), oxygen-glucose deprivation (OGD) or simulated ischemia-reperfusion (I/R). Ischemic stroke was induced in C57BL/6J mice by middle cerebral artery occlusion, followed by reperfusion. Neurological assessment was performed, brain tissue damage was quantified, and NLRP1 and NLRP3 inflammasome protein levels were evaluated. NLRP1 and NLRP3 inflammasome components were also analyzed in postmortem brain tissue samples from stroke patients. Ischemia-like conditions increased the levels of NLRP1 and NLRP3 inflammasome proteins, and IL-1ß and IL-18, in primary cortical neurons. Similarly, levels of NLRP1 and NLRP3 inflammasome proteins, IL-1ß and IL-18 were elevated in ipsilateral brain tissues of cerebral I/R mice and stroke patients. Caspase-1 inhibitor treatment protected cultured cortical neurons and brain cells in vivo in experimental stroke models. IVIg treatment protected neurons in experimental stroke models by a mechanism involving suppression of NLRP1 and NLRP3 inflammasome activity. Our findings provide evidence that the NLRP1 and NLRP3 inflammasomes have a major role in neuronal cell death and behavioral deficits in stroke. We also identified NLRP1 and NLRP3 inflammasome inhibition as a novel mechanism by which IVIg can protect brain cells against ischemic damage, suggesting a potential clinical benefit of therapeutic interventions that target inflammasome assembly and activity.

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.

Synthetic colourings of some snack foods consumed by primary school children aged 8-9 years in Hong Kong.

An HPLC method with photodiode array detection was used for the quantification of 11 synthetic dyes in 87 snack food products commonly consumed by children in Hong Kong, China. Dietary exposure to synthetic colours was estimated using food-frequency questionnaire data obtained from 142 primary school children aged 8-9 years in three districts of Hong Kong. Dietary exposure to synthetic colours for an average primary school student was considerably lower than the threshold for acceptable daily intake (ADI) for their ages, except for sunset yellow FCF. Data obtained showed that the average daily intake of sunset yellow FCF (E110) was 51% over the ADI threshold in 9-year-old boys. The higher intakes of sunset yellow FCF were mainly due to the high consumption of soft drinks and desserts such as jellies, which have high concentrations of this synthetic colour additive.

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.

Usefulness of the Chinese Nutrition Screening (CNS) tool in predicting 12 month mortality in elderly Hong Kong Chinese living in institutions.

OBJECTIVES: To determine the cut off score of the CNS in predicting 12 months mortality. DESIGN: Data was collected and followed up from a previous study among elderly subjects (n = 515) living in community institutional setting. The risk of malnutrition and 12 months mortality was ranked by the CNS and compared with that by SGA. Reliability was assessed by the sensitivity and specificity of the prediction with SGA as well as BMI alone. Sensitivity and specificity was calculated to determine validity as well as using positive and negative predictive values in predicting mortality at 12 months. RESULTS: All three tools (BMI, SGA, CNS) demonstrated significant difference of higher mortality rate (P < .001) in the malnourished group. CNS at score < or = 21 showed comparable results to SGA tool and BMI at classifying malnutrition. And using cut off score > or = 22 also show significant results with SGA in classifying patients with normal nutrition. CNS score at > or = 22 sensitivity was 60.9% and specificity was 72.9% with a Negative Predictive value of 92.3% and a Positive Predictive value of 25.8%. CONCLUSION: CNS tool at cut off > or = 22 is just as good as using BMI or SGA in identifying those who have a normal nutritional status. This is useful in particular, when biochemical or anthropometric data is not available. This further validates the use of > or = 22 as the best cut off point with the CNS tool and just as good at predicting of mortality when compared with SGA and BMI assessments.

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.

Expression of G protein beta subunits in rat skeletal muscle after nerve injury: Implication in the regulation of neuregulin signaling.

Tight regulation of gene transcription is critical in muscle development as well as during the formation and maintenance of the neuromuscular junction (NMJ). We previously demonstrated that the transcription of G protein beta1 (Gbeta1) is enhanced by treatment of cultured myotubes with neuregulin (NRG), a trophic factor that plays an important role in neural development. In the current study, we report that the transcript levels of Gbeta1 and Gbeta2 subunits in skeletal muscle are up-regulated following sciatic nerve injury or blockade of nerve activity. These observations prompted us to explore the possibility that G protein subunits regulate NRG-mediated signaling and gene transcription. We showed that overexpression of Gbeta1 or Gbeta2 in COS7 cells attenuates NRG-induced extracellular signal-regulated kinase (ERK) 1/2 activation, whereas suppression of Gbeta2 expression in C2C12 myotubes enhances NRG-mediated ERK1/2 activation and c-fos transcription. These results suggest that expression of Gbeta protein negatively regulates NRG-stimulated gene transcription in cultured myotubes. Taken together, our observations provide evidence that specific heterotrimeric G proteins regulate NRG-mediated signaling and gene transcription during rat muscle development.

Homeopathically prepared gibberellic acid and barley seed germination.

The potentisation process by which homeopathic preparations are produced raises the concern that these medicines have placebo effects only, since they theoretically no longer contain active molecules of the diluted substance. Plant models offer a method of examining the efficacy of homeopathically prepared solutions. This study examined the effects of homeopathically prepared gibberellic acid (HGA3) on the germination performance of barley (Hordeum vulgare L.) seeds. The effect of HGA3 (4-200 cH) on seed germination rate and seedling development was compared to that of the most commonly used form of gibberellic acid (GA3), 0.5 g l(-1), and control (distilled water). The extent and type of response was dependent on the vigour level of the seedlot. Treating seeds from three vigour groups in HGA3 consistently resulted in larger seedlings. High-vigour seeds treated with HGA3 4, 30 and 200 cH germinated faster, and roots of medium-vigour seedlots treated in HGA3 15 cH were longer. Biphasic effects of HGA3 were also demonstrated. As a plant model, germinating barley seeds successfully demonstrated the ability of HGA3 to produce a biological response.