Xsox17alpha and -beta mediate endoderm formation in Xenopus

We have isolated two Xenopus relatives of murine Sox17 expressed in gastrula presumptive endoderm. Xsox17alpha and -beta expression can be induced in animal caps by activin, but not by FGF. Ectopic expression of these genes in animal caps induces the expression of endoderm markers; this induction is blocked by overexpression of a fusion of the Xsox17beta HMG domain to the Drosophila Engrailed repressor domain, as is induction of endoderm markers by activin and the expression of endodermal markers in whole embryos and isolated vegetal poles. These experiments, as well as the effects of the mRNAs on embryo phenotypes, suggest that the Xsox17 genes mediate an activin-induced endoderm differentiation pathway in animal caps and are involved in normal endoderm differentiation in embryos.

Biomarkers of oxidative stress are significantly elevated in Down syndrome

There is convincing epidemiological and in vitro evidence of chronic oxidative stress in individuals with Down syndrome (DS). These individuals develop Alzheimer like changes in the brain in their 30s and 40s. The incidence of autoimmune diseases and cataracts is significantly increased, and the overall ageing process is accelerated. In vitro studies show that impaired viability of DS neurons may be amended by simple chemical antioxidants, such as vitamin E, BHT and propyl gallate, clearly indicative of oxyl radical involvement. However, because of the lack of in vivo experiments, the role of oxidative stress in DS remains controversial. We report here on the results of the chemical analyses of urine samples of 166 individuals, where DS subjects were matched by their siblings. The levels of 8-hydroxy-2'-deoxyguanosine (2.35 +/- 1.69 in DS vs. 1.35 +/- 1.04 in controls, P = 0.00011), a biomarker of oxidative damage to DNA, and malondialdehyde (0.255 +/- 0.158 in DS vs. 0.204 +/- 0.128 in controls, P = 0.033), a biomarker of lipid peroxidation, are significantly elevated in individuals with DS. Dietary influences failed to show any significant correlation with the oxidative stress biomarkers. These results provide direct evidence for increased oxidative stress in individuals with DS.

Mode of action of VegT in mesoderm and endoderm formation

mRNA encoding the T-box transcription factor VegT is located throughout the vegetal pole of the Xenopus egg and is believed to play an important part in endoderm and mesoderm formation. We find that VegT generates endoderm both by cell-autonomous action and by generating TGF-beta family signals, the latter being entirely responsible for its mesoderm-inducing activity. Signalling molecules induced cell-autonomously by VegT include derriere, Xnr4 and activin B. Xnr1 and Xnr2 are also induced, but primarily in a non-autonomous manner. All of these signalling molecules are found in the blastula and gastrula vegetal pole and induce both endoderm and mesoderm in the animal cap assay, and hence are good candidates both for the endogenous zygotic mesoderm-inducing signal and for reinforcing the vegetal expression of endoderm markers.

Hormone replacement therapy prevents bone loss in patients with inflammatory bowel disease

Patients with inflammatory bowel disease have an increased prevalence of osteoporosis, and suffer high rates of spinal bone loss. Hormone replacement therapy (HRT) is effective in the treatment and prevention of osteoporosis but has not been studied in patients with inflammatory bowel disease. A two year prospective study of HRT in inflammatory bowel disease was performed in 47 postmenopausal women aged 44 to 67 years with ulcerative colitis (25) or Crohn's disease (22). Patients had radial and spinal bone density measured annually by single photon absorptiometry and quantitative computed tomography respectively. The mean (95% confidence intervals) annual change in radial bone density was +1.42%/yr (+0.58 to +2.26; P < 0.005) and for spinal bone +2.60%/yr (+1.06 to +4.15; p < 0.005). There was no significant correlation between rates of change of bone density at the two sites, or between the rates of change and the initial bone density either in the radius or spine. Twelve patients were given prednisolone during the study, and their rates of change for spinal bone density were lower, but values were not statistically significantly different from those who did not receive corticosteroids. Changes in bone density for patients with ulcerative colitis and Crohn's disease were not significantly different. The change in bone density did not correlate with the patients' age or number of years after the menopause. It is concluded that HRT is effective in prevention of bone loss in postmenopausal women with inflammatory bowel disease.

Semirigid instrumentation in the management of lumbar spinal conditions combined with circumferential fusion. A multicenter study

STUDY DESIGN

Patients with the diagnosis of degenerative disc conditions or spondylolisthesis undergoing circumferential fusion with posterior pedicle screw fixation using a semirigid rod were reviewed.

OBJECTIVES

To determine the effectiveness of this approach in achieving a spinal fusion and satisfactory clinical outcome, and to determine the complications associated with the procedure.

SUMMARY OF BACKGROUND DATA

The use of instrumentation to stabilize the lumbar motion segments and thereby enhance the fusion rate has been proposed in a number of studies. Semirigid fixation was believed to be effective in achieving these objectives without concern for stress-shielding, which was suggested by some authors using rigid fixation systems.

METHODS

Patients who required spinal fusion with anterior and posterior approaches because of specific lumbar pathology or previous surgeries were selected. The surgery consisted of an anterior interbody fusion using allograft, followed by a posterolateral fusion and pedicle screw fixation. Fusion was determined by continuity of trabecular bridging, and outcomes were determined by pain reduction and return to previous levels of activity. Fusion was considered solid if the two posterolateral areas were fused (Zones one and two), if the anterior interbody area was fused (Zone three), or if all three zones were fused. Complications were documented during and after surgery.

RESULTS

Sixty-two percent of patients had previous surgery with 25% of these patients having a diagnosis of pseudarthrosis. Fifty-five percent of patients had two or more levels fused, and 43% were heavy smokers. Ninety-seven percent of patients had successful fusions. Pain was significantly reduced on a pain analogue scale from 7.1 to 2.1 in the back and from 5.8 to 1.5 in the leg (p < 0.006 and 0.0001, respectively). Fifty-nine percent of patients returned to their previous level of activity, and 18% returned to lighter work or job retraining, for a total of 77% returning to the same or lighter levels of activity. Complications included metal failure, 4.9%; neurologic deficit, 1.2%; deep infection, 1.2%; deep venous thrombosis, 4.9%; and vascular injury, 2.4%. Fatal pulmonary embolus occurred in one patient.

CONCLUSION

This technique produces a satisfactory fusion rate (97%) and a good clinical outcome based on pain reduction and return to a satisfactory level of activity (77%). It is associated with few, but significant, complications that compare well with other reported series in a difficult group of patients. This procedure should be reserved for patients who are considered to be at high risk for not achieving spinal fusion.

Orthotopic liver transplantation: postoperative complications and their management

The Birmingham liver transplant programme started in 1982. Forty-six patients have been transplanted with a follow-up of 3 months or longer. Twenty-seven patients are still alive, of whom sixteen have lived for more than one year. The 30 day hospital mortality was 30.4 per cent and the actuarial predicted one year survival 55.5 per cent. Four patients have been regrafted for chronic rejection and graft failure. Thirteen patients have required surgery in the postoperative period for: bleeding (two), removal of abdominal packs (four), biliary leaks and obstruction (five), duodenal perforation (one) and small bowel obstruction (one). Acute rejection was common, occurring in 30 patients and progressing to chronic rejection in 4. Ten patients developed renal failure with an 80 per cent mortality and eleven patients developed grand mal fits. Severe bleeding (greater than 70 units) was associated with previous abdominal surgery and a high mortality (88.9 per cent). Opportunistic fungal infection carried a 100 per cent mortality. Although more than half of all transplanted patients will survive for more than one year, the postoperative period is still one of high morbidity and mortality.

Distinct regulatory control of the Brachyury gene in axial and non-axial mesoderm suggests separation of mesoderm lineages early in mouse gastrulation

Brachyury is required for the normal extension of the anteroposterior axis during mouse embryogenesis. A transgene comprising sequences from -500 to +150 relative to the start of Brachyury transcription, and the reporter gene lacZ, recapitulates some, but not all elements of Brachyury expression. Beta-Galactosidase expression is seen in the primitive streak from 6.5 d.p.c. but there is no detectable reporter expression in the node or notochord. Thus, the regulatory sequences required for the expression of Brachyury in the cells traversing the primitive streak are distinct from those required for the initiation of expression in the node. This suggests that different or additional signals are involved in activation of Brachyury in the node and notochord than those inducing Brachyury in the primitive streak. Additionally, the data suggest the possibility that axial and non-axial mesoderm are distinct from the earliest stages of Brachyury expression.

A four-year longitudinal study of bone loss in patients with inflammatory bowel disease

Serial measurements of spinal trabecular and radial cortical bone density were made over 4 years in 70 patients with inflammatory bowel disease. Mean rates of bone loss for the cohort differed little from rates reported in normal populations; however, some patients showed increased rates of loss, including patients whose bone density at entry to the study was already well below normal. There was a significant correlation between the amount of corticosteroid prescribed and spinal trabecular bone loss in males, but no significant correlation with other clinical parameters. Increased rates of bone loss emphasise the need for bone densitometry and prophylactic measures in patients with inflammatory bowel disease.

High incidence of poor sulfoxidation in patients with primary biliary cirrhosis

An impaired sulfoxidation pathway has been implicated in the pathogenesis of chlorpromazine-induced hepatotoxicity. Since some patients with chronic chlorpromazine-induced cholestasis may have features of primary biliary cirrhosis, we studied the ability to sulfoxidate the amino acid analogue S-carboxymethyl-cysteine in 44 patients with primary biliary cirrhosis and in two control groups--one without liver disease and one with a variety of liver diseases other than primary biliary cirrhosis. Poor sulfoxidation was observed in 84 percent of the patients with primary biliary cirrhosis, as compared with 24 percent of patients with other liver diseases and 22 percent of normal controls (P less than 0.0005 for both comparisons). Poor sulfoxidation did not correlate with the degree of hyperbilirubinemia or histologic severity of liver disease in any of the groups studied. There was an inverse correlation with age only in the patients with primary biliary cirrhosis (r = -0.44, P less than 0.001). Liver transplantation was performed in six of the patients and improved sulfoxidation in five; in the four with primary biliary cirrhosis, sulfoxidation improved from poor to good or intermediate. We conclude that poor sulfoxidation is closely associated with primary biliary cirrhosis but not with the other liver diseases we studied.

Biopsy findings in cases of rejection of liver allograft

Features of rejection were found in 21 needle biopsies obtained from seven patients after liver transplantation. Wedge biopsies taken peroperatively were used as a baseline for comparison. Rejection was diagnosed by excluding other known causes of graft dysfunction using appropriate methods. In cases in which these criteria were fulfilled a consistent picture of rejection was seen, and this was useful in clinical management. Two features constantly present in cases of acute rejection were: a dense mixed portal inflammatory infiltrate; and polymorphonuclear infiltration of biliary epithelium.

Longitudinal study of cortical bone loss in patients with inflammatory bowel disease

Bone mineral density of the radius was measured by single-photon absorptiometry in 50 patients with inflammatory bowel disease. Thirty-three had Crohn's disease and 17 ulcerative colitis; 25 were women. The mean age was 45 years (range, 18-70 years). Measurements were repeated in 39 of them after a mean follow-up period of 7.9 years (range, 7.1-8.2 years). In female patients the mean (95% confidence interval) annual change in radial bone mineral density was -0.74% (-1.34% to -0.14%) (P = 0.022), the greatest bone loss occurring in postmenopausal women (mean, -1.16% (-2.01% to -0.30%)). In male patients the mean annual rate of bone loss was -0.07% (-0.41% to 0.28%) (P = NS). Patients with abnormally low values at the first measurement remained osteopenic at the second measurement, whilst some others with normal values initially showed increased rates of bone loss and had a subnormal bone mineral density after the follow-up period. These results show increased rates of cortical bone loss in some patients with inflammatory bowel disease and emphasize the need to monitor bone mass in these patients so that prophylactic measures can be instituted.

Gemcitabine enhances the efficacy of reovirus-based oncotherapy through anti-tumour immunological mechanisms

BACKGROUND

Reovirus preferentially infects and kills cancer cells and is currently undergoing clinical trials internationally. While oncolysis is the primary mode of tumour elimination, increasing evidence illustrates that reovirus additionally stimulates anti-tumour immunity with a capacity to target existing and possibly relapsing cancer cells. These virus-induced anti-tumour immune activities largely determine the efficacy of oncotherapy. On the other hand, anti-viral immune responses can negatively affect oncotherapy. Hence, the strategic management of anti-tumour and anti-viral immune responses through complementary therapeutics is crucial to achieve the maximum anti-cancer benefits of oncotherapy.

METHODS

Intra-peritoneal injection of mouse ovarian surface epithelial cells (ID8 cells) into wild-type C57BL/6 mice was treated with a therapeutic regimen of reovirus and/or gemcitabine and then analysed for prolonged survival, disease pathology, and various immunological parameters. Furthermore, in vitro analyses were conducted to assess apoptosis, viral spread, and viral production during reovirus and/or gemcitabine treatment.

RESULTS

We demonstrate that reovirus and gemcitabine combination treatment postpones peritoneal carcinomatosis development and prolongs the survival of cancer-bearing hosts. Importantly, these anti-cancer benefits are generated through various immunological mechanisms, including: (1) inhibition of myeloid-derived suppressor cells recruitment to the tumour microenvironment, (2) downmodulation of pro-MDSC factors, and (3) accelerated development of anti-tumour T-cell responses.

CONCLUSION

The complementation of reovirus with gemcitabine further potentiates virus-initiated anti-cancer immunity and enhances the efficacy of oncotherapy. In the context of ongoing clinical trials, our findings represent clinically relevant information capable of enhancing cancer outcomes.

Short-term outcomes with intrathecal versus epidural analgesia in laparoscopic colorectal surgery

BACKGROUND

Epidural analgesia is the mainstay of perioperative pain management in enhanced recovery programmes. This study compared short-term outcomes following epidural or intrathecal analgesia in patients undergoing elective laparoscopic colorectal surgery.

METHODS

A single-centre observational study was carried out in 175 consecutive patients who had elective laparoscopic colorectal surgery for benign or malignant disease within an enhanced recovery programme. Seventy-six patients received epidural analgesia and 99 had a single injection of intrathecal analgesia to provide perioperative pain control.

RESULTS

Patients who had intrathecal analgesia had a reduced median postoperative pain score compared with those receiving epidural analgesia (0 versus 3.5; P < 0.001), an earlier return to mobility (1 versus 4 days; P < 0.001) and a shorter hospital stay (4 versus 5 days; P < 0.001). Return to normal gut function and postoperative nausea and vomiting were similar in the two groups.

CONCLUSION

Intrathecal analgesia may have advantages over epidural analgesia in patients undergoing laparoscopic colorectal surgery.

Safety and cellular and humoral immune responses of a booster dose of varicella vaccine 6 years after primary immunization

Four hundred nineteen children and adolescents immunized with live varicella vaccine 4-6 years earlier were enrolled in a study to evaluate the safety and immune response to a booster dose containing approximately 3300 pfu of virus. Of the subjects, 99% (414/419) maintained antibody to varicella zoster virus (VZV) with a geometric mean titer of 25.7 and mean stimulation index (SI) for VZV-specific lymphoproliferation response of 40.3 +/- 5.3 (SE). Some 7-10 days after the booster immunization, seropositivity rates increased to 100% (302/302), and GMT was 143.6 (anamnestic response). At 6 weeks after the booster inoculation, a subset of subjects had 100% seropositivity (74/74) with a GMT of 218.8 and an SI of 58.6. After 3 months, seropositivity was 100% (358/358), GMT was 119.0, and SI was 61.4.

The NAD(+) salvage pathway modulates cancer cell viability via p73

The involvement of the nicotinamide adenine dinucleotide (NAD(+)) salvage pathway in cancer cell survival is poorly understood. Here we show that the NAD(+) salvage pathway modulates cancer cell survival through the rarely mutated tumour suppressor p73. Our data show that pharmacological inhibition or knockdown of nicotinamide phosphoribosyltransferase (NAMPT), a rate-limiting enzyme in the NAD(+) salvage pathway, enhances autophagy and decreases survival of cancer cells in a p53-independent manner. Such NAMPT inhibition stabilizes p73 independently of p53 through increased acetylation and decreased ubiquitination, resulting in enhanced autophagy and cell death. These effects of NAMPT inhibition can be effectively reversed using nicotinamide mononucleotide (NMN), the enzymatic product of NAMPT. Similarly, knockdown of p73 also decreases NAMPT inhibition-induced autophagy and cell death, whereas overexpression of p73 alone enhances these effects. We show that the breast cancer cell lines (MCF-7, MDA-MB-231 and MDA-MB-468) harbour significantly higher levels of NAMPT and lower levels of p73 than does the normal cell line (MCF-10A), and that NAMPT inhibition is cytotoxic exclusively to the cancer cells. Furthermore, data from 176 breast cancer patients demonstrate that higher levels of NAMPT and lower levels of p73 correlate with poorer patient survival, and that high-grade tumours have significantly higher NAMPT/p73 mRNA ratios. Therefore, the inverse relationship between NAMPT and p73 demonstrable in vitro is also reflected from the clinical data. Taken together, our studies reveal a new NAMPT-p73 nexus that likely has important implications for cancer diagnosis, prognosis and treatment.

Determining the spatial distribution of viable and nonviable bacteria in hydrated microcosm dental plaques by viability profiling

AIMS

The aim of this study was to use confocal laser scanning microscopy (CLSM) to examine the spatial distribution of both viable and nonviable bacteria within microcosm dental plaques grown in vitro. Previous in vivo studies have reported upon the distribution of viable bacteria only.

METHODS AND RESULTS

Oral biofilms were grown on hydroxyapatite (HA) discs in a constant-depth film fermenter (CDFF) from a saliva inoculum. The biofilms were stained with the BacLight LIVE/DEAD system and examined by CLSM. Fluorescence intensity profiles through the depth of the biofilm showed an offset between the maximum viable intensity and the maximum nonviable intensity. Topographical differences between the surface properties of the viable and nonviable biofilm virtual surfaces were also measured.

CONCLUSIONS

The profile of fluorescence intensity from viable and nonviable staining suggested that the upper layers of the biofilm contain proportionally more viable bacteria than the lower regions of the biofilm.

SIGNIFICANCE AND IMPACT OF STUDY

Viability profiling records the transition from predominantly viable to nonviable bacteria through biofilms suggesting that this technique may be of use for quantifying the effects of antimicrobial compounds upon biofilms. The distribution of viable bacteria was similar to that found in dental plaque in vivo suggesting that the CDFF produces in vitro biofilms which are comparable to their in vivo counterparts in terms of the spatial distribution of viable bacteria.

A proposed mechanism for chlorpromazine jaundice--defective hepatic sulphoxidation combined with rapid hydroxylation

On the basis of previous experimental studies we postulated that individuals who were phenotypically good hydroxylators but poor sulphoxidisers would be susceptible to chlorpromazine jaundice. Sulphoxidation capacity was assessed in 12 subjects with a history of chlorpromazine jaundice, using S-carboxymethyl-L-cysteine as an in vivo probe. Following an oral dose of 750 mg, unchanged compound and sulphoxide metabolites were measured in urine. All 12 subjects (100%) were shown to be poor sulphoxidisers compared to 22% of normal controls (P less than 0.001) and 23.8% of liver disease controls (P less than 0.001). No subjects with a history of chlorpromazine jaundice had an impaired hydroxylation capacity as assessed by recovery of 4-hydroxydebrisoquine in urine following oral debrisoquine. The results support the hypothesis and demonstrate an inherent metabolic basis of susceptibility to chlorpromazine jaundice.

Epithelioid haemangioendothelioma. A case report

Epithelioid haemangioendothelioma of the liver is an extremely rare tumour which has only recently been recognised. This report describes the clinical, radiological and histological findings in a case of a primary epithelioid haemangioendothelioma of the liver. The case highlights some of the difficulties in establishing the diagnosis, and in its differentiation from Budd-Chiari syndrome and veno-occlusive disease. The patient has subsequently undergone successful orthotopic hepatic transplantation.

Changes in embryonic cell fate produced by expression of an endodermal transcription factor, Xsox17

Many molecules induce the ectopic expression of tissue-specific genes in Xenopus embryos. Conversely, interfering with their activity disrupts patterns of gene expression, implicating them in normal development. Does this mean that they control cell fate (i.e. position, as well as differentiation)? Xsox17alpha and beta can induce ectopic expression of endodermal markers; inhibiting their function suppresses expression of endodermal marker genes in the developing gut (Cell 91 (1997) 397). Here we show the effect of these manipulations on cell lineage. Expressing Xsox17 in a cells normally fated to become ectoderm causes their descendants either to relocate into the embryonic gut or to die at a late developmental stage. Conversely, disrupting Xsox17 activity in cells normally fated to be endodermal causes them to enter mesodermal and ectodermal lineages.

Rectus abdominis myocutaneous flaps for perineal reconstruction: modifications to the technique based on a large single-centre experience

INTRODUCTION

Perineal wound breakdown with delayed wound healing represents a significant cause of morbidity following surgery and radiotherapy to the perineum. The rectus abdominis myocutaneous (RAM) flap has been used increasingly to reconstruct the perineum with good effect. We describe our six-year experience of reconstruction of the perineum with the RAM flap and share some surgical adjuncts we believe are useful.

METHODS

We conducted a retrospective case note review of all patients who underwent a reconstruction of the perineum using the RAM flap between August 2003 and October 2009. Indications for the flap, complication rates and outcomes were all observed.

RESULTS

We conducted 16 RAM flap procedures, 15 of which (94%) were primary repairs and 1 (6%) a secondary repair. Three (19%) developed donor site hernias, two (12.5%) developed minor perineal wound infections, eight (50%) developed minor perineal wound breakdown and in one (6%) flap failure was observed. No perineal hernias were observed. There were no surgical mortalities.

CONCLUSIONS

The RAM flap has a high success rate and an acceptable morbidity rate and is a useful tool in the reconstruction of complex perineal wounds. Modifications to the standard surgical technique may reduce complications and improve the versatility of this flap.

Indocyanine green clearance in acute rejection after liver transplantation

Previous animals studies have demonstrated a fall in liver blood flow associated with acute rejection after liver transplantation. To study the relationship between rejection and liver blood flow in humans after liver transplantation indocyanine green (ICG) clearance was measured serially in 7 patients with clinical and histological features of acute rejection. There was a consistent pattern of satisfactory initial ICG clearance that fell in association with acute rejection and rose with successful treatment of the episode of rejection. In one patient there was no improvement in ICG clearance after treatment with additional immunosuppression, and she subsequently required retransplantation for chronic rejection. The volume of distribution of ICG was also estimated and fell considerably during the first weeks after transplantation. These results show that rejection is associated with a reduction in ICG clearance that may be due to a fall in liver blood flow, and that graft ischemia and rejection may therefore be interrelated, and important in one another's etiology.

Interference of antibody production to hepatitis B surface antigen in a combination hepatitis A/hepatitis B vaccine

A randomized trial comparing 3 manufacturing consistency lots of a combination hepatitis A/hepatitis B vaccine to each other and to hepatitis A vaccine and hepatitis B vaccine given separately and concurrently was done to evaluate safety, tolerability, and immunogenicity. Healthy volunteers >/=11 years of age were divided into 4 groups. Each of 3 groups received a separate consistency lot of the combination vaccine, and 1 group received separate but concurrent injections of hepatitis A and hepatitis B vaccines. Injections were given at weeks 0 and 24. The combination vaccine was generally well tolerated. The hepatitis A portion of the combination vaccine produced clinically acceptable high seropositivity rates 4 and 52 weeks after the first injection. The hepatitis B portion of the vaccine did not produce clinically acceptable seropositivity rates 4 weeks after the second injection. Lack of antibody production may be attributed, at least in part, to immunologic interference.

Effect of somatostatin on oesophageal variceal pressure assessed by direct measurement

The effect of a single bolus of somatostatin on oesophageal variceal pressure has been studied in 7 patients with cirrhosis and 5 patients with non-cirrhotic portal hypertension using a non-invasive variceal pressure gauge. Both groups of patients demonstrated similar reductions in variceal pressure with all subjects demonstrating a fall. The timing, duration and magnitude of this reduction in variceal pressure in response to somatostatin showed considerable individual variation which may explain the previous reports of a variable response to treatment of variceal haemorrhage with somatostatin. This individual variation should be borne in mind in the planning of future studies in the treatment of oesophageal variceal haemorrhage. The pneumatic pressure gauge allows the non-invasive study of the effects of drugs on variceal and portal pressure.