Antiproliferative triterpenes from Melaleuca ericifolia

Three new 28-norlupane triterpenes, 28-norlup-20(29)-en-3beta-hydroxy-17beta-hydroperoxide (1), 28-norlup-20(29)-en-3beta-hydroxy-17alpha-hydroperoxide (2), and 20 S-17beta,29-epoxy-28-norlupan-3beta-ol (3), were isolated from the leaves of Melaleuca ericifolia along with eight known pentacyclic triterpenes. The structures of the new compounds were elucidated by spectroscopic methods including 1D and 2D NMR spectroscopy and mass spectrometry. The isolated triterpenes were evaluated for antiproliferative activity against the malignant +SA mammary epithelial cell line.     

Glyburide metabolism by placentas of healthy and gestational diabetics

The aim of this investigation was to determine the metabolism of glyburide (GL) by microsomes prepared from placentas obtained from uncomplicated pregnancies (UP), women with gestational diabetics (GD) on a diabetic diet, and those on a diet and GL. Term placentas were obtained from UP and GD. Crude microsomal fractions were prepared by differential centrifugation and stored at -80 degrees C. The activity of the microsomes in metabolizing glyburide to the trans-4-hydroxycyclohexyl glyburide (THCGL) and cis-3-hydroxycyclohexyl glyburide (CHCGL) was determined and quantified using high-performance liquid chromatography-mass spectrometer (HPLC-MS). The activity of the placental microsomes varied widely between individual placentas in each group. The median values (pmol.mg (-1) P.min (-1)) for the rates of THCGL formation were 0.34, 0.3, and 0.23 for placentas of UP, GD on diet, and GD on GL and a diet, respectively. The median values for CHCGL formation were 0.13 for UP, 0.11 for GD on a diet, and 0.10 (pmol.mg (-1) P.min (-1)) for GD on GL and a diet. A pool of individual microsomal fractions from each group was prepared and its activity revealed the following: greater formation of THCGL in the UP (0.36 +/- 0.10) than GD (0.22 +/- 0.03) ( P = 0.058 for GD on a diet, 0.04 for GD on GL). There was greater formation of CHCGL in UP (0.26 +/- 0.04) than GD (0.12 +/- 0.003) ( P < 0.006). There was no difference in GD on a diet and GD on GL plus diet. We concluded that the apparent differences in the formation of metabolites may be statistically significant, but it is unlikely to be of physiological importance, given the sample size and other experimental factors. Therefore, a more comprehensive investigation is underway.     

Risk factors of the failure of surfactant treatment by transient intubation during nasal continuous positive airway pressure in preterm infants

We sought to identify risk factors and neonatal outcomes associated with the failure of the INSURE method ( INtubation- SURfactant- Extubation) during nasal continuous positive airway pressure for preterm infants with respiratory distress syndrome. We used a retrospective analysis of the prenatal histories, clinical courses, and laboratory data of all inborn infants with gestational age 27 to 34 weeks and respiratory distress syndrome treated with INSURE method. Infants were categorized into two groups: INSURE failure group and INSURE success group. One hundred nine infants were eligible to the study. INSURE failure was registered in 35 infants (32.1%). After control for confounding variables, INSURE failure was significantly associated with arterial partial pressure of carbon dioxide (adjusted odds ratio [OR] = 1.82; 95% confidence interval [CI] = 1.76 to 90.56), mean arterial-to-alveolar oxygen tension ratio (adjusted OR = 1.13; 95% CI = 1.06 to 85.34) and severe radiological grade (adjusted OR = 1.31; 95% CI = 1.15 to 70.16). Positive predictive values of these variables were 70, 75, and 55%, respectively. Patent ductus arteriosus and mortality rates were significantly higher in INSURE failure group. Arterial partial pressure of carbon dioxide, arterial-to-alveolar oxygen tension ratio, and severe radiological grade are predictors of the failure of INSURE method in preterm infants with respiratory distress syndrome. However, a prospective randomized controlled trial is needed to determine whether or not infants at risk for INSURE failure are better off being treated with mechanical ventilation.     

Magnetic resonance imaging and hysteroscopy to diagnose colo-uterine fistula: a rare complication of diverticulitis

Colo-uterine fistula of diverticular origin is an extremely rare disease due to the resistance of uterine tissue. Methods for diagnosis remain to be established. Non-invasive imaging like magnetic resonance imaging (MRI) may help to establish a proper diagnosis, but confirmation may be reached by diagnostic hysteroscopy or even surgical exploration. We report a 78-year-old female who presented with continuous dull aching pain associated with increasing constipation. MRI suspected a fistula between the posterior aspect of the uterine body and the sigmoid colon which contained extensive diverticulosis. Hysteroscopy confirmed the fistulous opening, but colonoscopy confirmed diverticular disease with no evidence of malignancy. The patient had en block surgical treatment of the uterus and the adjacent colon, followed by an uneventful recovery. The sensitivity and specificity of non-invasive imaging procedures to diagnose such cases remain to be established. As imaging procedures cannot rule out neoplasia, endoscopic procedures need to be added.     

Effect of passive uterine straightening during embryo transfer: a systematic review and meta-analysis

BACKGROUND: Part of the success of ultrasound-guided embryo transfer has been associated with the beneficial effect of uterine straightening by passive bladder distention. Even so, this has not been properly analysed in the literature. METHODS: This is a systematic review and meta-analysis of prospective, randomised, controlled trials, comparing embryo transfer with a full versus empty bladder. Electronic (e.g. PubMed, EMBASE, Cochrane Library) and hand searches were performed to locate trials. Primary outcomes were live-birth, ongoing and clinical pregnancy rates. Secondary outcomes were rates of implantation, miscarriage, multiple and ectopic pregnancies, and retained embryos. Also, the ease of transfer, need for instrumental assistance, and presence of blood on the catheter tip were evaluated. Four studies were identified, of which 1 study was excluded. Meta-analysis was conducted with the Mantel-Haenszel method, utilising the fixed-effect model. RESULTS: For the primary outcome measures, no data was available for the LBR rate. There was a significantly higher chance of an ongoing pregnancy [OR=1.44 (95% CI=1.04-2.04)] and clinical pregnancy [OR=1.55 (95% CI=1.16-2.08)] with a full bladder. For the secondary outcomes, there was a significantly greater incidence of difficulty, or need for instrumental assistance, with an empty bladder. Other outcome measures were not significantly different. CONCLUSION: There is evidence in the literature advising to fill the bladder prior to embryo transfer.     

Prenatal diagnosis of beta-thalassemia: 12 years' experience at a single laboratory in Pakistan

OBJECTIVE: To evaluate the service for prenatal diagnosis of beta-thalassemia in Pakistan. METHODS: All prenatal diagnoses (PNDs) for beta-thalassemia since the introduction of the service in 1994 were studied. PND was done by the Amplification Refractory Mutation System (ARMS), or linkage analysis, when required. The reported errors in PND were investigated for clerical mistakes, technical problems with PCR, maternal contamination and nonpaternity. RESULTS: In the 12 years 2174 PNDs were done for beta-thalassemia at the country's main referral center. The use of PND has increased from 26 in 1994 to 381 in 2006. Over 97% of the couples who requested PND already had an affected child. In over 97% of the cases PND was done by direct mutation analysis. The reported rate of misdiagnosis was 0.37%. The causes of misdiagnoses included one clerical mistake, three false positive PCR results, and two maternal contaminations in the chorionic villus sampling (CVS). CONCLUSION: PND for beta-thalassemia is technically feasible by direct mutation analysis in most cases in Pakistan. The procedure is quick and cost effective. Strict quality assurance can achieve an acceptably low error rate.     

Microstructural Evolution,Tensile Failure,Fatigue Behavior and Wear Properties of Al2O3 Reinforced Al2014 Alloy T6 Heat Treated Metal Composites

The paper focused on an experimental study on the microstructural, mechanical, and wear characteristics of 15 wt.% alumina (Al₂O₃) particulates with an average particle size of 20 µm, reinforced in Al2014 alloy matrix composite as-cast and heat-treated samples. The metal matrix composite (MMC)samples were produced via a novel two-stage stir-casting technique. The fabricated composite samples were subjected to evaluate hardness, tensile strength, fatigue behavior and wear properties for both as cast and T6 heat-treated test samples. The Al2014 alloy and Al2014-15 wt.% Al₂O₃ MMCs were in solution for 1 h at a temperature of 525 °C, quenched instantly in cold water, and then artificially aged for 10 h at a temperature of 175 °C. SEM and X-ray diffraction analyses were used to investigate the microstructure and dispersion of the reinforced Al₂O₃ particles in the composite and the base alloy Al2014. The obtained results indicated that the hardness, tensile and fatigue strength and wear resistance increased when an amount of Al₂O₃ particles was added, compared to the as-cast Al2014 alloy and it was observed that after subjecting the same composite samples to heat treatment, there was further enhancement in the mechanical and wear properties in the Al2014 matrix alloy and Al2014-15 wt.% Al₂O₃ composite samples.