Better induction and differentiation strategy for rat pancreatic stem cells: transplant in liver niche

Current in vitro induction protocols cannot generate mature islet cells from stem cells. Transplantation into the liver niche may greatly contribute to the maturity of pancreatic stem cells (PSCs) due to its similarity to the pancreas. To determine the effect of the liver niche on the differentiation of PSCs, we used neonatal Wistar rat pancreata for cultivation of PSCs, which were transplanted into diabetic Wistar rats via the portal vein or beneath the renal capsule. After transplantation, we measured random blood glucose, weight, and serum insulin and performed an intraperitoneal glucose tolerance test. Specimens were examined by immunofluorescence. As a result, highly proliferating harvested cells showed the characteristics of stem cells. The PSCs could be induced to form large islet-like structures (150-200 mum diameter) in the liver, which resulted in better therapeutic efficacy. In contrast, there were smaller islet-like structures (about 50 mum diameter) when PSCs were transplanted beneath the renal capsule. These findings demonstrated that the liver niche benefits the in vivo differentiation of PSCs into endocrine and exocrine cells that may contribute to the generation of insulin producing cells.

Insight into the dicrotic notch in photoplethysmographic pulses from the finger tip of young adults

This study aims to investigate arterial stiffness in selected young adults by non-invasively determining the characteristics of the photoplethysmographic dicrotic notch. A total of 15 volunteers participated in this study, divided into four groups by age and gender. Contour analysis was applied to analyse the photoplethysmographic dicrotic notch, including time-related and height-related parameters. The height of reflected wave, mirrored by the notch relative amplitude (NRA), was found to be significantly larger in the older group compared to the younger group (p = 0.016). The timing of the reflected wave, measured by three parameters, i.e. notch index (NI), notch latency (NL) and peak-to-notch latency (PTNL), significantly increased in the female group compared to the male group (all p < 0.02). The results confirm that arterial stiffness occurs in young adults, and demonstrate that a difference of arterial stiffness exists between young male and female. This study indicates that examining the characteristic notch of the PPG pulse could help in identifying differences of vascular activities.

Reoperation of biliary tract by laparoscopy

BACKGROUND

Patients with previous operation of biliary tract were considered in the past as a contraindication to perform reoperation by laparoscopy. As experience with laparoscopic techniques and instrumentation has expanded, laparoscopic reoperation of biliary tract has become an accepted procedure in the management of cholelithiasis. Here we introduce our interesting experience with regard to reoperation of biliary tract by laparoscopy.

METHODS

Laparoscopic operation of biliary tract was performed on 3,674 consecutive patients from April 1992 to June 2005. Among these patients, 26 had a previous open operation of biliary tract whose clinical data were analyzed retrospectively : seven cases had complicated intrahepatic bile duct stones (restricted at hepatic duct of the first and the 2nd order); Diameter of common bile duct in patients with common duct stones was above 1.2 cm and the numbers of stones from each patient was more than 3 and the biggest stone exceeded 1 cm. All 26 patients were preoperatively excluded to present stenosis of bile duct and malignant tumor by both radiological examination and detection of serological tumor markers.

RESULTS

The mean operative time was 125 min (75-190 min). Reoperations of biliary tract by laparoscopy were successfully accomplished in 25 patients. One patient was converted to open operation whose common duct stones were taken out by right angle forceps through a short incision. None of the patients developed any severe complication and all of them recovered and were discharged. Three cases with retained calculus were successfully cured by taking them out through the sinus tract of T tube.

CONCLUSIONS

Laparoscopic procedure is minimally invasive, is safe and feasible for reoperation of the biliary tract. And it is a first choice method for cases to whom endoscopic sphincterotomy is contraindicated.

Aspirin induces apoptosis in mesenchymal stem cells requiring Wnt/beta-catenin pathway

BACKGROUND AND OBJECTIVES

Mesenchymal stem cells (MSC) are multipotent progenitor cells that are have found use in regenerative medicine. We have previously observed that aspirin, a widely used anti-inflammatory drug, inhibits MSC proliferation. Here we have aimed to elucidate whether aspirin induces MSC apoptosis and whether this is modulated through the Wnt/beta-catenin pathway.

MATERIALS AND METHODS

Apoptosis of MSCs was assessed using Hoechst 33342 dye and an Annexin V-FITC/PI Apoptosis Kit. Expression of protein and protein phosphorylation were investigated using Western blot analysis. Caspase-3 activity was detected by applying a caspase-3/CPP32 Colorimetric Assay Kit.

RESULTS

In these MSCs, aspirin induced morphological changes characteristic of apoptosis, cytochrome c release from mitochondria, and caspase-3 activation. Stimulating the Wnt/beta-catenin pathway by both Wnt 3a and GSK-3beta inhibitors (LiCl and SB 216763), blocked aspirin-induced apoptosis and protected mitochondrial function, as demonstrated by decreased cytochrome c release and caspase-3 activity. Aspirin initially caused a time-dependent decrease in COX-2 expression but subsequently, and unexpectedly, elevated the latter. Stimulation of COX-2 expression by aspirin was further enhanced following stimulation of the Wnt/beta-catenin pathway. Application of the COX-2 inhibitor NS-398 suppressed elevated COX-2 expression and promoted aspirin-induced apoptosis.

CONCLUSION

These results demonstrate that the Wnt/beta-catenin pathway is a key modulator of aspirin-induced apoptosis in MSCs by regulation of mitochrondrial/caspase-3 function. More importantly, our findings suggest that aspirin may influence MSC survival under certain conditions; therefore, it should be used with caution when considering regenerative MSC transplantation in patients with concomitant chronic inflammatory diseases such as arthritis.

A comparison of regional and general anaesthesia for total replacement of the hip or knee: a meta-analysis

We performed a meta-analysis to evaluate the relative efficacy of regional and general anaesthesia in patients undergoing total hip or knee replacement. A comprehensive search for relevant studies was performed in PubMed (1966 to April 2008), EMBASE (1969 to April 2008) and the Cochrane Library. Only randomised studies comparing regional and general anaesthesia for total hip or knee replacement were included. We identified 21 independent, randomised clinical trials. A random-effects model was used to calculate all effect sizes. Pooled results from these trials showed that regional anaesthesia reduces the operating time (odds ratio (OR) -0.19; 95% confidence interval (CI) -0.33 to -0.05), the need for transfusion (OR 0.45; 95% CI 0.22 to 0.94) and the incidence of thromboembolic disease (deep-vein thrombosis OR 0.45, 95% CI 0.24 to 0.84; pulmonary embolism OR 0.46, 95% CI 0.29 to 0.80). Regional anaesthesia therefore seems to improve the outcome of patients undergoing total hip or knee replacement.

Filamin A is essential for active cell stiffening but not passive stiffening under external force

The material properties of a cell determine how mechanical forces are transmitted through and sensed by that cell. Some types of cells stiffen passively under large external forces, but they can also alter their own stiffness in response to the local mechanical environment or biochemical cues. Here we show that the actin-binding protein filamin A is essential for the active stiffening of cells plated on collagen-coated substrates. This appears to be due to a diminished capability to build up large internal contractile stresses in the absence of filamin A. To show this, we compare the material properties and contractility of two human melanoma cell lines that differ in filamin A expression. The filamin A-deficient M2 cells are softer than the filamin A-replete A7 cells, and exert much smaller contractile stresses on the substratum, even though the M2 cells have similar levels of phosphorylated myosin II light chain and only somewhat diminished adhesion strength. In contrast to A7 cells, the stiffness and contractility of M2 cells are insensitive to either myosin-inhibiting drugs or the stiffness of the substratum. Surprisingly, however, filamin A is not required for passive stiffening under large external forces.

Imaging considerations for in vivo 13C metabolic mapping using hyperpolarized 13C-pyruvate

One of the challenges of optimizing signal-to-noise ratio (SNR) and image quality in (13)C metabolic imaging using hyperpolarized (13)C-pyruvate is associated with the different MR signal time-courses for pyruvate and its metabolic products, lactate and alanine. The impact of the acquisition time window, variation of flip angles, and order of phase encoding on SNR and image quality were evaluated in mathematical simulations and rat experiments, based on multishot fast chemical shift imaging (CSI) and three-dimensional echo-planar spectroscopic imaging (3DEPSI) sequences. The image timing was set to coincide with the peak production of lactate. The strategy of combining variable flip angles and centric phase encoding (cPE) improved image quality while retaining good SNR. In addition, two aspects of EPSI sampling strategies were explored: waveform design (flyback vs. symmetric EPSI) and spectral bandwidth (BW = 500 Hz vs. 267 Hz). Both symmetric EPSI and reduced BW trended toward increased SNR. The imaging strategies reported here can serve as guidance to other multishot spectroscopic imaging protocols for (13)C metabolic imaging applications.

Phase I study of pemetrexed (P) and pegylated liposomal doxorubicin (PLD) in patients with refractory breast, ovarian, primary peritoneal, or fallopian tube cancer

e13515

Background: P and PLD are clinically active as single agents and synergistic in preclinical models. This phase I, open-label trial determined the maximum tolerated dose (MTD) and safety profile of P followed by PLD in patients (pts) with breast or gynecologic cancers. Methods: Using standard phase I (3+3 dose escalation) study design, cohorts of 3–9 pts received escalating doses of P followed by PLD in 28-day cycles: P 400–500 mg/m2 on Days 1 and 15 and PLD 30–45 mg/m2 on Day 1. All pts received folic acid (350–1000 μg daily) and vitamin B12 (1000 μg) until 21 days after last dose of P. Pts continued until dose-limiting toxicity (DLT) or disease progression (PD) occurred. Results: From 11/05 to 1/08, 29 pts were registered/treated. Median age: 60.6 years (range, 47.5–80.1); ECOG performance status 0/1: 28%/72%; primary disease sites: ovarian (55%), breast (35%), peritoneal (10%); prior therapies: chemotherapy (100%), surgery (72%), hormones/biologics (35%), radiation (21%). Dosing results are shown below. At dose level (L) 2 and L3, 1 pt/cohort had DLTs; L5 was added and 3/3 pts had DLTs; 4 more pts were treated at L4 (1 pt replaced). Most frequent drug-related Grade 3–4 hematologic toxicities: neutropenia (86%), leukopenia (59%), thrombocytopenia (48%), anemia (41%). Most frequent drug-related Grade 3–4 nonhematologic toxicities: hand-foot syndrome (14%), hypokalaemia (10%). Major reasons for discontinuation: PD (48%), toxicity (28%), pt request (14%). Overall best responses (n=24): 5 pts (21%) had partial response (PR), 14 pts (58%) had stable disease (SD), 2 pts (8%) had PD, 3 pts (13%) were not evaluable. All 5 PR and 8 SD pts were ovarian; 5 SD and both PD pts were breast. Conclusions: P followed by PLD was reasonably tolerated in this heavily-pretreated population. The MTD was P 500 mg/m2 and PLD 40 mg/m2. These dose levels may be carried forward to phase II studies in more specific patient populations.

[Table: see text]

[Table: see text]

Preliminary results of a randomized phase II study of paclitaxel and bevacizumab ± gemcitabine as first-line treatment for metastatic breast cancer

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Background: The addition of bevacizumab (B) to paclitaxel (P) results in a significant improvement in PFS in pts with metastatic breast cancer (MBC) (Miller K, et al. New Engl J Med 2007). A randomized Phase II trial examining the efficacy and safety of adding gemcitabine (G) to the PB doublet has completed enrollment. Reported here are preliminary efficacy and safety results. Methods: This is a US, multicenter, randomized, superiority trial. Eligible pts have locally advanced or metastatic breast cancer, ECOG PS 0 or 1, and no prior cytotoxic therapy for metastatic disease. Prior adjuvant or neoadjuvant treatment with a taxane or endocrine therapy is allowed. Pts are randomized to receive P 90 mg/m2 on Days 1, 8, and 15, followed by B 10 mg/kg on Days 1 and 15 of a 28-day cycle, or the same regimen plus G 1,500 mg/m2 on Days 1 and 15. Primary endpoint is response rate according to RECIST criteria. Results: Between May 2006 and February 2008, 189 women were randomized to treatment. The table below summarizes currently available results. Grades 1–2 alopecia occurred in 28% of pts in the PB arm and in 38% of pts in the PB+G arm. One pt (2%) in the PB arm experienced a Grade 3 nosebleed. Grades 3 and 4 thrombotic events occurred respectively in 0% and 2% of pts in the PB arm, and in 3% and 2% of pts in the PB+G arm. Four pts (7%) in the PB arm and 3 pts (5%) in the PB+G arm discontinued due to treatment-related AEs. Three on-study deaths have occurred, none deemed related to study treatment. Conclusions: Study follow-up is ongoing. Full results will be available at the time of the meeting. Therapy with PB ± G is feasible and does not appear to be associated with significant bleeding or thrombotic events. As expected, the addition of G to the PB doublet appears to increase the incidence of neutropenia in pts with MBC.

[Table: see text]

[Table: see text]

Multiplexed immunobead-based assay for detection of oral cancer protein biomarkers in saliva

OBJECTIVE

For clinical applications of biomarkers, there is a need for multiplex assays using high throughput platforms. The objective of this study was to determine the efficacy of Luminex Multianalyte Profiling (xMAP) technology for measurement of salivary proteins and to evaluate whether multiplex assays are as effective as single-plex assays and enzyme-linked immunosorbent assay (ELISA).

RESULTS

The average levels of interleukin-8 (IL-8) from the single-plex assay were 3313.2 +/- 3759.8 pg ml(-1) [oral squamous cell carcinoma (OSCC), n = 20] and 1061.7 +/- 1978.8 pg ml(-1) (control, n = 20). The IL-1beta average levels from the single-plex assay were 945.2 +/- 1134.8 pg ml(-1) (OSCC, n = 20) and 314.2 +/- 444.8 pg ml(-1) (control, n = 20). The average levels of IL-8 from the multiplex assay were 2834.9 +/- 3385.6 pg ml(-1) (OSCC, n = 20) and 947.3 +/- 2036.8 pg ml(-1) (control, n = 20). The IL-1beta average levels from the multiplex assay were 1013.5 +/- 1221.1 pg ml(-1) (OSCC, n = 20) and 376.3 +/- 576.3 pg ml(-1) (control, n = 20). The correlation coefficient between Luminex and ELISA assay for IL-8 (n = 19) and IL-1beta (n = 19) was 0.91 and 0.84, respectively.

CONCLUSION

Luminex xMAP single-plex and multiplex assays are as effective as ELISA assays for quantification of proteins in saliva. Both IL-8 and IL-1beta were expressed at significantly higher levels in OSCC subjects than in the matched healthy control subjects.

Monophyletic origin of domestic bactrian camel (Camelus bactrianus) and its evolutionary relationship with the extant wild camel (Camelus bactrianus ferus)

The evolutionary relationship between the domestic bactrian camel and the extant wild two-humped camel and the factual origin of the domestic bactrian camel remain elusive. We determined the sequence of mitochondrial cytb gene from 21 camel samples, including 18 domestic camels (three Camelus bactrianus xinjiang, three Camelus bactrianus sunite, three Camelus bactrianus alashan, three Camelus bactrianus red, three Camelus bactrianus brown and three Camelus bactrianus normal) and three wild camels (Camelus bactrianus ferus). Our phylogenetic analyses revealed that the extant wild two-humped camel may not share a common ancestor with the domestic bactrian camel and they are not the same subspecies at least in their maternal origins. Molecular clock analysis based on complete mitochondrial genome sequences indicated that the sub-speciation of the two lineages had begun in the early Pleistocene, about 0.7 million years ago. According to the archaeological dating of the earliest known two-humped camel domestication (5000-6000 years ago), we could conclude that the extant wild camel is a separate lineage but not the direct progenitor of the domestic bactrian camel. Further phylogenetic analysis suggested that the bactrian camel appeared monophyletic in evolutionary origin and that the domestic bactrian camel could originate from a single wild population. The data presented here show how conservation strategies should be implemented to protect the critically endangered wild camel, as it is the last extant form of the wild tribe Camelina.

SNP deserts of Asian cultivated rice: genomic regions under domestication

When performing a genome-wide comparison between indica (93-11) and japonica (Nipponbare), we find 8% of the genome, which have an extremely low SNP rate (< 1 SNP/kb). Inside these 'SNP deserts', experimentally confirmed genes show increased K(a)/K(s) that indicate adaptive selection. To further elucidate this connection, we survey the level and pattern of genetic variation in both cultivated and wild rice groups, using 155 noncoding regions located within SNP deserts. The results suggest that cultivated rice has greatly reduced genetic variation within SNP deserts as compared to either the nondesert or corresponding genomic regions in wild rice. Consistent with this reduction in genetic variation, we find a biased distribution of derived allele frequency in the cultivated group, indicative of positive selection. Furthermore, over half of the confirmed, domestication-related genes are found within SNP deserts, also suggesting that SNP deserts are strongly related to domestication, and might be the key sites in the process of domestication.

The epidemiology and surgical outcomes of patients undergoing primary total hip replacement: an Asian perspective

INTRODUCTION

The number of total knee replacements far exceeds the number of primary total hip replacements (THR) in Singapore. There is a paucity of data regarding patients who undergo THR in Singapore. This paper aimed to study the epidemiology and early postoperative outcomes of patients receiving primary THR in a single tertiary institution.

METHODS

This is a retrospective study of all patients undergoing primary THR between January 2003 and December 2005. The following variables were analysed: patient demographics, surgical approach, mode of implant fixation, postoperative complications and functional outcomes using D'Aubigne and Postel scoring.

RESULTS

There were a total of 115 patients who underwent primary THR over a 36-month period. The mean age of patients was 55 (range 23-80) years. The male-to-female ratio was 1:2. The most common diagnoses in descending order were as follows: inflammatory arthritis, osteoarthritis, avascular necrosis, hip dysplasia and post-traumatic osteoarthritis. Patients were evaluated at a mean follow-up of 41 months, with 90.8 percent having excellent and good outcomes. There were no statistical differences between the surgical approach and implant fixation with regard to postoperative outcome.

CONCLUSION

In Asian patients, the three commonest aetiologies for degenerative hip arthritis were inflammatory arthropathies, primary osteoarthritis and avascular necrosis. Regardless of diagnosis, the patient groups had comparable functional outcomes following THR.

Interleukin-1beta release in the supraoptic nucleus area during osmotic stimulation requires neural function

Interleukin (IL)-1beta is present throughout the magnocellular neuroendocrine system and co-depletes with oxytocin and vasopressin from the neural lobe during salt-loading. To examine whether IL-1beta is released from the dendrites/soma of magnocellular neurones during osmotic stimulation, microdialysis adjacent to the supraoptic nucleus (SON) in conscious rats was combined with immunocapillary electrophoresis and laser-induced fluorescence detection to quantify cytokine in 5-min dialysates collected before (0-180 min; basal), and after (180-240 min), hypertonic saline injected s.c. (1.5 m NaCl). Osmotic release of IL-1beta was compared after inhibiting local voltage-gated channels for Na+ (tetrodotoxin) and Ca2+ (cadmium and nickel) or by reducing intracellular Ca2+ stores (thapsigargin). Immunohistochemistry combined with microdialysis was used to localise cytokine sources (IL-1beta+) and microglia (OX-42+). Under conditions of microdialysis, the basal release of IL-1beta+ in the SON area was measurable and stable (pg/ml; mean +/- SEM) from 0-60 min (2.2 +/- 0.06), 60-120 min (2.32 +/- 0.05) and 120-180 min (2.33 +/- 0.06), likely originating locally from activated microglia (OX42+; IL-1beta+; ameboid, hypertrophied) and magnocellular neurones expressing IL-1beta. In response to osmotic stimulation, IL-1beta increased progressively in dialysates of the SON area by a mechanism dependent on intracellular Ca2+ stores sensitive to thapsigargin and, similar to dendritic secretion of oxytocin and vasopressin, required local voltage-gated Na+ and Ca2+ channels for activation by osmoregulatory pathways from the forebrain. During osmotic stimulation, neurally dependent release of IL-1beta in the SON area likely upregulates osmosensitive cation currents on magnocellular neurones (observed in vitro by others), to facilitate dendritic release of neurohypophysial hormones.

Prosaposin is an AR-target gene and its neurotrophic domain upregulates AR expression and activity in prostate stromal cells

Recent studies have introduced prosaposin (PSAP) as a pleiotrophic growth factor for prostate cancer (PCa). We have previously reported that PSAP or one of its known active molecular derivatives, saposin C functions as an androgen-agonist and androgen-regulated gene (ARG) for androgen-sensitive (AS) PCa cell lines. Due to the potential significance of androgen receptor (AR)-expressing stroma in PCa, we evaluated a possible bi-directional paracrine regulatory interactions between DHT and PSAP in AR-positive prostate stromal (PrSt) cells. We report that saposin C in a ligand-independent manner increased AR expression, its nuclear content, and tyrosine phosphorylation. DHT treatment of PrSt cells increased PSAP expression. We also demonstrated both serum- and androgen-inducibility of a previously characterized hormone-responsive element (HRE) located in the proximal region of PSAP promoter. In addition, conditioned-media derived from PrSt cells and bone fibroblasts (i.e., MSF) differentially increased PSAP-promoter activity in androgen-independent (AI) PC-3 and AS LNCaP cells. Our data for the first time demonstrate that not only saposin C or PSAP regulates AR expression/activity, but also function as an ARG in PrSt. Ligand-independent activation of AR by PSAP or saposin C in PCa and stromal cells may contribute not only to prostate carcinogenesis at an early stage, but also in AI progression of the disease in an androgen-deprived tumor microenvironment.