Dinoprostone vaginal pessary for induction of labour: safety of use for up to 24 h.

BACKGROUND: Cervidil(®) (dinoprostone) intravaginal pessaries are used for induction of labour and maintain serum prostaglandin levels for up to 24 h. The Therapeutic Goods Administration approves Cervidil(®) for 12-h use. However, twenty-four-hour use of Cervidil(®) is supported in Europe, New Zealand, America and some Australian hospitals. AIM: To assess the safety of Cervidil(®) use for up to 24 h for induction of labour in nulliparous women. METHODS: A retrospective cohort study of 269 consecutive women receiving Cervidil(®) at the Royal Brisbane and Women's Hospital (RBWH) between July 2007 and December 2008 was performed. The primary outcome measures were frequency of, and time to, uterine tachysystole with or without fetal heart rate (FHR) changes. Secondary outcome measures included frequency of maternal (intrapartum temperature, postpartum haemorrhage) and neonatal (low Apgars, resuscitation, nursery admission) morbidity. Morbidity outcomes of those who received Cervidil(®) for less than or equal to 12 h were compared with those who received Cervidil(®) for more than 12 h. RESULTS: Uterine tachysystole occurred in 9.3% of patients receiving Cervidil(®) , with a mean time to tachysystole of 10 h. The majority of cases (68%) occurred within 12 h of use. There was no increase in maternal or neonatal morbidity for those who received Cervidil(®) for longer than 12 h. CONCLUSION: Twenty-four-hour use of Cervidil(®) is likely as safe as 12-h use for induction of labour in nulliparous women.

The role of hypoxia in stem cell differentiation and therapeutics.

Stem cells differentiate into a variety of cell lines, making them attractive for tissue engineering and regenerative medicine. Specific microenvironmental cues regulate self-renewal and differentiation capabilities. Oxygen is an important component of the cellular microenvironment, serving as both metabolic substrate and signaling molecule. Oxygen has been shown to have a variety of effects on embryonic and adult stem cells. This review examines the role of hypoxia in regulating stem cell biology, specifically focusing on growth, maintenance of pluripotency, differentiation, and production of growth factors. Particular attention is paid to hypoxia and stem cells in relation to therapeutic angiogenesis. We conclude that further study is needed to optimize the use of hypoxia as a stimulus for various stem cell functions, including its potential role in therapeutic angiogenesis.

Differentiation of adult stem cells into smooth muscle for vascular tissue engineering.

BACKGROUND: Herein we evaluate the potential of adipose-derived stem cells (ASC) to differentiate into smooth muscle cells (SMC) and their potential for use in a tissue-engineered vascular graft. MATERIALS AND METHODS: We isolated ASC (CD13+29+90+) from the peri-umbilical adipose tissue of patients undergoing vascular surgery, and cultured them in media containing angiotensin II (AngII), sphingosylphosphorylcholine (SPC), or transforming growth factor-beta 1 (TGFß1) for up to 3 weeks. SMC differentiation was assessed by (1) expression of early (calponin, caldesmon) and late (myosin heavy chain, MHC) SMC markers by RT-PCR, qPCR and Western blot, and (2) contraction upon plating on collagen gel. Differentiated ASCs were seeded onto a vascular graft (decellularized saphenous vein) within a bioreactor, and cell attachment was determined using confocal microscopy. RESULTS: Prior to differentiation, ASC expressed low levels of all three molecular markers. After culture in each differentiating medium, the extent of up-regulation of calponin, caldesmon, and MHC was variable across all cell lines. After seeding onto collagen gel, ASCs differentiated in SPC and TGFß1 exhibit contractile properties, similar to smooth muscle cell controls. Differentiated stem cells adhered and proliferated on the vascular graft. CONCLUSION: These data suggest that human adipose-derived stem cells (1) exhibit variable expression of SMC molecular markers after differentiation, (2) exhibit a contractile phenotype after differentiation with SPC and TGFß1, and (3) proliferate on a vascular graft scaffold. Thus, ASCs are potentially useful in the construction of autologous arteries.

Anastomotic leak rate after low anterior resection for rectal cancer after chemoradiation therapy.

Anastomotic leak may be the most concerning complication after colorectal anastomosis. To compare open with laparoscopic rectal resection, we must have accurate leak rates in patients who have received neoadjuvant chemoradiation therapy to serve as a benchmark for comparison. All patients who had preoperative chemoradiation therapy with rectal resection and low pelvic anastomosis for cancer in a single colorectal practice over a 7-year period were retrospectively reviewed. All patients had proximal diversion and a contrast enema study before stoma reversal. Eighty-seven consecutive patients were included in the study. Average age was 58 years. Fifty-nine per cent of patients were male. Sixty-six per cent were smokers. Pathologic T stage was 5 per cent T0, 16 per cent T1, 28 per cent T2, 47 per cent T3, and 5 per cent T4. Seventy-five per cent of patients were pathologically lymph node-negative. Average time to stoma reversal was 122 days. Total anastomotic leak rate was 10.3 per cent (8% clinical leaks). Five (56%) patients with leak successfully underwent reversal of their diverting stoma (average time to reversal, 290 days). Patients who had the complication of anastomotic leakage had less likelihood of stoma reversal and a significantly prolonged time to stoma reversal.

Outcomes of low anterior resection anastomotic leak after preoperative chemoradiation therapy for rectal cancer.

Anastomotic leak remains a major cause of morbidity and mortality after colorectal surgery, especially with low anastomoses. The aim of this study was to assess outcomes of patients who developed an anastomotic leak after low anterior resection of the rectum for rectal cancer. An Institutional Review Board-approved retrospective review of 89 consecutive patients undergoing open low anterior resection with primary anastomosis for cancer of the mid/lower rectum at a single institution between January 2001 and December 2008 was performed. All patients received neoadjuvant chemotherapy and radiation therapy. Proximal diversion was performed in all patients. Perioperative data were collected and analyzed with attention to management and outcomes after development of anastomotic leak. Nine patients (10.1%) developed anastomotic leak. Mean age was 62 years. Mean tumor level was 4.8 cm above the anal verge. Symptomatic anastomotic leak developed in seven (78%) patients. Percutaneous drainage was performed in five (55.6%) patients with an average of 4.4 procedures required for management of anastomotic leak. Five (55.6%) patients required reoperation. Only two procedures (25%) involved laparotomy. No operative procedures were performed emergently. There were no mortalities. Excluding one patient who received completion proctectomy for local recurrence, restoration of intestinal continuity was achieved in five (63%) of eight patients. Mean time to stoma closure was 289 days. The potentially lethal complication of anastomotic leak after low anterior resection for rectal cancer can be managed expectantly and electively in patients who are proximally diverted with the expectation of stoma reversal in the long term.

Availability of adipose-derived stem cells in patients undergoing vascular surgical procedures.

BACKGROUND: Most research evaluating adipose-derived stem cells (ASC) uses tissue obtained from young, healthy patients undergoing plastic surgical procedures. Given the propensity of other adult stem cell lines to diminish with increasing patient age and co-morbidities, we assess the availability of ASC in elderly patients undergoing vascular surgical procedures, and evaluate their acquisition of endothelial cell (EC) traits to define their potential use in vascular tissue engineering. METHODS AND METHODS: Adipose tissue obtained by liposuction from patients undergoing vascular procedures (n = 50) was digested with collagenase and centrifuged to remove mature adipocytes. The resultant number of cells, defined as the stromal-vascular (SV) pellet, was quantified. Following a 7-d culture period and negative selection for CD31 and CD45, the resultant number of ASC was quantified. After culture in differentiating media (EMG-2), ASCs were tested for the acquisition of endothelial-specific traits (expression of CD31, realignment in shear, cord formation on Matrigel). RESULTS: The SV pellet contained 2.87 ± 0.34 × 10(5) cells/g fat, and the resultant number of ASCs obtained was 1.41 ± 0.18 × 10(5) cells/g fat. Flow cytometry revealed a homogeneous ASC population (>98% positive for CD13, 29, 90). Advanced age or co-morbidity (obesity, diabetes, renal or peripheral vascular disease) did not significantly alter yield of ASC. After culture in differentiating media (EMG-2), ASCs acquired each of the endothelial-specific traits. CONCLUSION: ASC isolation appears independent of age and co-morbidities, and ASCs harvested from patients with vascular disease retain their ability to differentiate into endothelial-like cells. Adipose tissue, therefore, is a practical source of autologous, adult stem cells for vascular tissue engineering.

Optimal technical management of stump closure following distal pancreatectomy: a retrospective review of 215 cases.

BACKGROUND: Pancreatic fistula (PF) is a major source of morbidity following distal pancreatectomy (DP). Our aim was to identify risk factors related to PF following DP and to determine the impact of technique of transection and stump closure. METHODS: We performed a retrospective review of 215 consecutive patients who underwent DP. Perioperative and postoperative data were collected and analyzed with attention to PF as defined by the International Study Group of Pancreatic Fistula. RESULTS: PF developed in 36 patients (16.7%); fistulas were classified as Grade A (44.4%), B (44.4%), or C (11.1%). The pancreas was transected with stapler (n = 139), cautery (n = 70), and scalpel (n = 3). PF developed in 19.8% of remnants which were stapled/oversewn and 27.7% that were stapled alone (p = 0.4). Of the 69 pancreatic remnants transected with cautery and oversewn, a fistula developed in 4.3% (p = 0.004 compared to stapled/oversewn; p = 0.006 compared to stapled/not sewn). The median length of postoperative hospital stay was significantly increased in patients who developed PF (10 vs. 6 days, p = 0.002) CONCLUSION: The method of transection and management of the pancreatic remnant plays a critical role in the formation of PF following DP. This series suggests that transection using electrocautery followed by oversewing of the pancreatic remnant has the lowest risk of PF.

Incidence of anastomotic leak in patients undergoing elective colon resection without mechanical bowel preparation: our updated experience and two-year review.

Mechanical bowel preparation before elective colon resection has recently been questioned in the literature. We report a prospective study evaluating the anastomotic leak rate in patients undergoing elective colorectal surgery without preoperative mechanical bowel preparation. One hundred fifty-three patients undergoing elective colon resection from July 2006 to June 2008 were enrolled into this Institutional Review Board-approved study. All patients were operated on by a single surgeon at a single institution. No patients received mechanical bowel preparation. Of the 153 patients enrolled, 51.6 per cent had a colorectostomy, 32 per cent had an ileocolostomy, 10.4 per cent had a colocolostomy, 5.2 per cent had an ileoanal anastomosis, and 0.6 per cent had an ileorectostomy performed. A total of eight patients (5.2%) developed an anastomotic leak. Of these patients, four required reoperation, three were managed with percutaneous drainage, and one was managed with antibiotics alone. Five of the eight patients who developed an anastomotic leak had significant preoperative comorbidities, including neoadjuvant radiation therapy, diabetes mellitus, end-stage renal disease, prior anastomotic leak, and tobacco use. Elective colon resection can be performed safely without preoperative mechanical bowel preparation. Vigilance for anastomotic leak must be maintained at all times, especially in patients with comorbidities that predispose to anastomotic leak.

Overexpression, purification and characterization of the Trichoderma atroviride endochitinase, Ech42, in Pichia pastoris.

The endochitinase gene ech42 from Trichoderma atroviride was cloned and expressed in Pichia pastoris using a constitutive expression system. Over 98% of the recombinant protein was secreted into the culture medium as glycoprotein. A high endochitinase concentration, 186 mg/L with a specific enzyme activity of 14,128 Umg(-1) was produced. The optimal enzyme kinetic parameters for the recombinant protein were identical to those reported for the enzyme isolated from T. atroviride. The recombinant endochitinase possesses suitable features for biotechnological applications, such as activity at acidic pH and thermostability.

Crystals of the beta-subunit of bovine luteinizing hormone and indicators for the involvement of proteolysis in protein crystallization.

The beta-subunit of luteinizing hormone (LH), the subunit responsible for the physiological response, has been crystallized beginning with the intact alphabeta-heterodimeric hormone purified from bovine pituitary glands. The crystals were grown at 310 K in the presence of neutral detergents along with trypsin. The tetragonal bipyramidal crystals diffract to 3 A resolution and belong to space group I4(1)22, with unit-cell parameters a = b = 57, c = 207 A. It is noted that proteins exposed to proteases sometimes yield products that crystallize better than the native molecule and that the beta-subunit of LH represents yet another example. Some indicators of when proteolysis may be a factor in crystallization, as well as some consequences, are described.

A functional interaction between CD46 and DLG4: a role for DLG4 in epithelial polarization.

Using a yeast two-hybrid screen, we identified a physical interaction between CD46 and DLG4. CD46 is a ubiquitous human cell-surface receptor for the complement components C3b and C4b and for measles virus and human herpesvirus 6. DLG4 is a scaffold protein important for neuronal signaling and is homologous to the Drosophila tumor suppressor DLG. We show that an interaction between CD46 and DLG4 is important for polarization in epithelial cells. Specifically, we show (i) biochemical evidence for an interaction between CD46 and DLG4, (ii) that this interaction is specific for the Cyt1 (but not Cyt2) domain of CD46, (iii) that both CD46 and an alternatively spliced isoform of DLG4 are polarized in normal human epithelial cells, and (iv) that the polarized expression of CD46 in epithelial cells requires the DLG4-binding domain and alters with expression of a truncated form of DLG4. This is the first identification of a direct and cytoplasmic domain-specific interaction between CD46 and an intracellular signaling molecule and provides a molecular mechanism for the polarization of CD46. These data also indicate that, in addition to the known role for DLG4 in neuronal cells, DLG4 may be important for polarization in epithelial cells.