An open-label, acute clinical trial in adults to assess ketone levels, gastrointestinal tolerability, and sleepiness following consumption of (R)-1,3-butanediol (Avela™)

Introduction: A study was undertaken to determine the acute effects of a beverage made with Avela™ (R)-1,3-butanediol, on blood beta-hydroxybutyrate (BHB) levels (using the Keto-Mojo monitor), gastrointestinal (GI) tolerability (using the modified visual analogue scale GI Symptoms Tool), and sleepiness (using the Stanford Sleepiness Scale). Methods: Following a 12-h overnight fast, 26 healthy adults consumed one beverage containing 11.5 g of (R)-1,3-butanediol at each of 0, 30, and 60 min, culminating in a total intake of 34.5 g of (R)-1,3-butanediol. Blood BHB levels, GI tolerability, and sleepiness were assessed at baseline (0 min), and at 30, 60, 90, 120, 180, 240, and 300 min. At 240 min, a protein bar was consumed. Results: The mean (±SD) BHB fasting baseline level, maximal concentration, time at maximal concentration, and incremental area under the curve over 300 min were 0.23 ± 0.21 mmol/L, 2.10 ± 0.97 mmol/L, 133.85 ± 57.07 min, and 376.73 ± 156.76 mmol/L*min, respectively. BHB levels at each time point were significantly increased relative to baseline. In females, BHB T_max was significantly greater (p = 0.046), and BHB iAUC_0-300 min nearly significantly greater (p = 0.06) than in males. Discussion: The beverage formulated with Avela™ had no impact on sleepiness and was generally well-tolerated, with no or mild GI symptoms reported in most participants. Mild headaches were reported as an adverse event by five participants and judged possibly related to the study product in two of the participants.

EXPRESSION LEVELS OF FOXO-1, P27KIP1, MIR-27, MIR-186 AND AKT1/AKT-P PROTEINS IN WOMEN WITH ENDOMETRIAL CANCER AND HYPERPLASIA: IMPLICATIONS FOR THE HUMAN REPRODUCTIVE SYSTEM

Objectives

Despite extensive research on endometrial cancer (EC) and endometrial hyperplasia, there is still a gap in understanding the molecular mechanisms underlying their development and progression. The aim of this study was to investigate the expression levels of FOXO-1, P27Kip1, miR-27, and miR-186, and Akt1, Akt-P proteins in patients with EC and endometrial hyperplasia compared to control subjects.

Subjects and methods

Samples of the endometrial tumor (n=30), normal (control) (n=30) and endometrial hyperplastic (n=30) tissue were obtained from patients referring to Arash and Imam Khomani hospitals, Tehran, Iran. Expression levels of genes and microRNAs were evaluated by qRT- PCR. Western blot analysis was applied for protein evaluation. The data were analyzed using t-test, Mann -Whitney U, Pearson correlation coefficient analysis, ANCOVA and ANOVA.

Results

There was significant decrease in FOXO-1 in EC tissue compared to control tissue (p<0.05). Significant increase was observed in expression of miR-27 in patients with EC (p<0.001) and hyperplasia (p<0.01), whereas miR-186 expression level increased significantly only in patients with EC (p<0.05). P27Kip1 expression level did not significantly change in patients with EC and hyperplasia. There was a significant association between expression levels of miR-27 with FOXO-1 and P27Kip1 in patients with EC. Western blot analysis revealed higher endometrial AKT1-P protein levels in patients with EC and hyperplasia than control subjects (p<0.05).

Conclusions

Our findings suggest that FOXO-1, miR-27, miR-186, and Akt1-P/Akt1 protein have the potential to serve as tissue biomarkers for early diagnosis, prognosis, and progression of EC in the human reproductive system.

Low- and no-calorie sweetener intakes in the Brazilian population estimated using added sugar substitution modelling

This research examined the intakes of six low- and no-calorie sweeteners (LNCS) (acesulfame-K, aspartame, cyclamate, saccharin, steviol glycosides, and sucralose) by the Brazilian population using an added sugar substitution approach. Detailed exposure modelling requires the use of proprietary concentration data, which can be difficult to obtain. Two exposure models were conducted using nationally representative food consumption data. The first model ('per person') estimated added sugar intakes on an individual person basis, replacing 50% of added sugar intakes >10% total energy with each LNCS considering sucrose sweetness equivalence. The second model ('per food') replaced 50% of the added sugar content in foods and beverages with each LNCS, incorporating sucrose sweetness equivalence and Brazilian tonnage data. Both models predicted that intakes would be below the JECFA ADI for five of the six LNCS in all population groups examined (≥10 years) for average and heavy consumers. For cyclamate, exceedance of the ADI was determined for all age groups amongst heavy consumers in the 'per person' model, while estimated intakes in the 'per food' model were below or reached the ADI for the cohort. Additional research is needed for younger age groups to confirm whether these findings are applicable to the entire Brazilian population.

Liver biomarkers in adults: Evaluation of associations with reported green tea consumption and use of green tea supplements in U.S. NHANES

Some events of hepatotoxicity have been linked to consumption of green tea supplements. The association between consumption of green tea or green tea supplements and abnormal liver biomarkers in adults was investigated using cross-sectional data from the 2009-2014 United States National Health and Nutrition Examination Survey (U.S. NHANES). Individuals with levels of either bilirubin or GGT, ALT, AST, and/or ALP in excess of the age- and gender-specific upper limits of normal ranges were classified as having abnormal liver biomarkers. Associations between green tea or green tea supplement use (consumption vs. not) and liver function were determined using multiple logistic regression modelling. 12,289 persons were included in the green tea analyses and 12,274 in the green tea supplement analyses. The odds of having one or more abnormal liver biomarkers were significantly reduced (p = 0.01) with consumption of green tea (OR: 0.49; 95% CI: 0.28, 0.85), while no significant association (p = 0.78) was determined for consumption of green tea supplements (OR: 0.92; 95% CI: 0.52, 1.64). Based on data from the 2009-2014 U.S. NHANES, green tea consumption was associated with reduced odds of having one or more abnormal liver biomarkers; whereas, no significant association was determined with consumption of green tea supplements.

A83 INTESTINAL EPITHELIAL CELL STEMNESS AND DIFFERENTIATION ARE REGULATED BY THE HIPPO PATHWAY EFFECTOR YAP1

Background

The high rate of cell turnover in the intestinal epithelium is supported by the LGR5+ crypt base columnar (CBC) stem cells, which are located at the lower part of the gland. Among of the various factors and signals like Wnt and Notch, YAP1 (yes associated protein) also plays an important role in stemness of CBC stem cells. YAP1 is the effector of the Hippo pathway. Hippo Pathway restricts the cells proliferation, tissues overgrowth and cancer formation through the phosphorylation and inactivation of the YAP1 protein. When active, YAP1 transfers into nucleus, forms the complex with TEADs transcription factors and promotes the transcription of genes involved in cell growth and proliferation.

Aims

In the present study, we investigated the role of the YAP1 in the colorectal cancer multipotent HT29 cell line, which contain cancer stem cells (CSC).

Methods

For approaching to this goal, YAP1 expression was knocked down using shRNAs in HT29 cells. Then stem cells and intestinal cell lineages (secretory goblet, Paneth and enteroendocrine and absorptive) markers expression was analyzed using qPCR and Western blot.

Results

The results showed the reduction of the expression of stem cells markers including LGR5 in YAP1 knockdown HT29 cells compare with control. Expression of the goblet cells markers (MUC2 and trefoil factor 3) and absorptive cells markers (sucrase-isomaltase and dipeptidylpeptidase IV) were significantly increased in YAP1 knockdown cells but Paneth (DEFA5 and lysozyme) and enteroendocrine (CHGA) were not detected. Finally, examination of the main transcription factors for intestinal differentiation revealed an increase in CDX2 expression.

Conclusions

These results suggest that YAP1 is involved in the maintenance of colorectal cancer stem cells while preventing intestinal differentiation in both secretory and absorptive lineages through the repression of CDX2.

Funding Agencies

CIHR

'Accepting where I'm at' - a qualitative study of the mechanisms, benefits, and impact of a behavioral memory intervention for community-dwelling older adults

OBJECTIVE

Gain novel, in-depth insight into therapeutic mechanisms, benefits, and impact of a multi-modal behavioral memory intervention for older adults with concerns about memory.

METHODS

Participants were11 community-dwelling older adults (aged 63-88) who completed the Memory and Aging Program, an evidence-based multi-modal group intervention for normal age-related memory change. Semi-structured interviews were administered post-intervention. Responses were analyzed using qualitative content analysis until meaningful themes were agreed upon.

RESULTS

Analyses revealed a main theme of normalization as the overarching benefit of participation. The mechanism for this comprised both specific intervention content and the process of participating with others. A positive impact of the intervention was demonstrated at emotional (feelings of reassurance, hope, and confidence) and functional (increasing motivation for lifestyle change) levels; for some, there was a direct link between emotion and function.

CONCLUSION

This study highlighted a single, prominent therapeutic benefit of normalization, illustrated a dual mechanism for achieving this, and characterized a nuanced inter-relationship of the emotional and functional impact of the intervention for participants. Results support the notion that group behavioral interventions can educate, empower, and promote psychological well-being in older adults and may be an effective avenue to reduce risk of disease and promote sustained functional independence.

Helicobacter pylori infection and iron deficiency in patients with coronary artery disease

The aim of this study was to investigate whether impact of the seropositivity to Helicobacter pylori (H pylori) infection on ferritin and iron levels is an independent risk factor for atherosclerosis in patients with cardiovascular disease. The anti H pylori IgG, IgA levels, serum ferritin and iron concentration of 86 patients with cardiovascular disease and 64 participants free of cardiovascular disease as control subjects were determined by ELISA assay. The results of present study showed that seropositivity to H pylori IgG and IgA levels of coronary artery disease (CAD) patients was higher than controls and CAD patients with negative anti H pylori IgG and IgA significantly. A significant negative correlation was found between seropositivity to H pylori IgG and IgA, ferritin and iron levels of CAD patients with seronegativity and seronegativity to H pylori IgG and IgA in comparison with controls. The achieved results from present study suggest that the involvement of H pylori infection in atherosclerosis process is based on the chronic inflammation which might facilitate the CAD-related pathologies. Moreover, impact of the presence of H pylori infection on reduction of the ferritin and iron levels of CAD patients as a risk factor independent of other classic factors including lipid profiles and inflammatory factors was remarkable.

The effect of Morus alba leaves extract and powder on resistin levels and liver transaminase enzymes activities in diabetes

The current study was designed to investigate the changes of the resistin, aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels of diabetic rats after treatment with Morus alba leaves flavonoid extract (MLE) and Morus alba leaves powder (MLP). Thirty male wistar rats in five groups including control and diabetic groups were included. Diabetic groups consisted of diabetic control, sham and treated group with MLE and MLP. Type 2 diabetes was induced in rats by administration of streptozotocin (STZ) and - nicotinamide. The serum concentrations of resistin and insulin in the study groups were identified by ELISA. ALT and AST activities were assayed by spectrophotometer. For the first time, it was shown that the uptake of MLE and MLP by diabetic rats could significantly decrease the serum fasting blood sugar (FBS), resistin levels and enzymes activity of ALT and AST and increases the concentration of serum insulin significantly (P<0.05). in comparison with the sham group and diabetic control. The results showed that there was no significant difference between the anti-diabetic and inflammatory properties of MLE and MLP. In this study, the possible protective effect of MLE and MLP administration was evaluated against destructive effect of STZ on liver and pancreas function in diabetic rats. The results showed that these effects may play an important role in the regulating of adipokines secretion such as resistin and insulin secretion which are involved in the control of diabetes and obesity. MLE and MLP treatment could be useful agents in combination with other therapies in diabetes improvement.

Human colon cancer HT-29 cell death responses to doxorubicin and Morus Alba leaves flavonoid extract

The mechanistic basis for the biological properties of Morus alba flavonoid extract (MFE) and chemotherapy drug of doxorubicin on human colon cancer HT-29 cell line death are unknown. The effect of doxorubicin and flavonoid extract on colon cancer HT-29 cell line death and identification of APC gene expression and PARP concentration of HT-29 cell line were investigated. The results showed that flavonoid extract and doxorubicin induce a dose dependent cell death in HT-29 cell line. MFE and doxorubicin exert a cytotoxic effect on human colon cancer HT-29 cell line by probably promoting or induction of apoptosis.

Prevalence of beta lactamase producing species of pseudomonas and acinetobacter in pediatric burn patients

Burn wound infection is a major cause of morbidity and mortality in burn victims. Pseudomonas and Acinetobacter species are among the most common organisms complicating burn wounds. Presence of extended spectrum ß-lactamase (ESBL) and metallo-ß-lactamase (MBL) genes plays an important role in spreading ß-lactam resistant strains of these organisms and is a serious condition in the treatment of the affected patients. As a result, we aimed to determine the prevalence of SHV, TEM, PER and VIM ß-lactamases in Pseudomonas and Acinetobacter species isolates from burn wound swabs of children with burn injury. In this descriptive observational study, 107 Pseudomonas and Acinetobacter isolates collected from burn patients were subjected to PCR assay. Using PCR method and DNA sequencing, the existence of SHV-, TEM-, PER- and VIM-type ß-lactamase encoding genes were determined. Out of the 107 Pseudomonas and Acinetobacter isolates, 66 (77.6%) were ESBL positive, 26.2% were positive for SHV gene, 37.4% were positive for TEM gene, 14% were positive for PER gene and 15.9% of them harbored VIM gene. More than half of the Pseudomonas and Acinetobacter strains in our pediatric burn unit harbor ß-lactamase encoding genes that make them resistant to a wide range of ß-lactam antibiotics. Consequently, it is suggested to choose an appropriate antibiotic regimen based on the antibiogram pattern of the strains.

Babies admitted to NICU/ICU: province of birth and mode of delivery matter

Neonatal intensive care units (NICUs) and intensive care units (ICUs) provide care for newborns in need of specialized medical attention. Across Canada, rates of NICU/ICU admission vary. Due to the high cost of monitoring and interventions these admissions cost more than general newborn stays - whether the newborn is in a specialized NICU or in an ICU in those facilities without specialized units for newborns. This study explores the variation in NICU/ICU admissions and the characteristics of mothers and newborns associated with an increased likelihood of NICU/ICU admission. We focus further on the association between NICU/ICU admission and Caesarean section (C-section). After excluding multiple births, preterm births, small for gestational age births and those delivered by women with select complications, we find an increased risk for NICU/ICU admission for babies born by C-section as their only indication. NICU/ICU admission following C-section alone may not represent the most desirable pathway of care for these newborns.

Bariatric surgery in Canada: a focus on day surgery procedures

Given the rise in obesity rates, increasing capacity for bariatric surgery has become a focus for some provincial planners. Four types of bariatric procedures are now performed in Canada; however, funding for the procedures varies by jurisdiction. This article provides an update to our previous article documenting the volume of in-patient bariatric procedures but focuses on the extent to which Canadians are increasingly receiving bariatric procedures in day surgery settings.

CIHI survey: bariatric surgery in Canada

Bariatric surgery is a treatment option for obese patients when weight-reduction strategies such as lifestyle modifications and pharmacotherapy fail. To date, bariatric surgery has resulted in sustained weight loss; the resolution of diabetes for some patients has also been observed. The objective of this study was to explore changes in-patient bariatric surgery delivery in Canada between 2004-2005 and 2008-2009.

Complications of Exteriorized Compared With In Situ Uterine Repair at Cesarean Delivery Under Spinal Anesthesia

OBJECTIVE

To compare intraoperative complications of exteriorized and in situ uterine repair during elective cesarean delivery under spinal anesthesia.

METHODS

This study was a randomized, single-blinded trial in 80 women undergoing elective cesarean delivery under spinal anesthesia. Patients were randomly assigned to exteriorized or in situ uterine repair. Obstetricians were asked to perform assisted delivery of the placenta. Spinal anesthesia and oxytocin management were standardized. Phenylephrine was used to maintain systolic blood pressure within 10% of the baseline. The primary outcome was intraoperative, postdelivery nausea or vomiting.

RESULTS

Postdelivery nausea or vomiting (18% compared with 38%; P=.04) and tachycardia (3% compared with 18%; P=.03) were significantly reduced in the in situ group compared with the exteriorized group. The duration of uterine repair was significantly shorter in the exteriorized group (median 10 minutes [first and third quartiles 9, 13], compared with 11 minutes [9, 15]) (P=.04). The duration of surgery (36 minutes [30, 41] compared with 37 minutes [30, 45]) and estimated blood loss (mean+/-standard deviation 625+/-489 mL compared with 653+/-416 mL) were similar between the in situ and the exteriorized groups. There was no correlation between duration of uterine repair and estimated blood loss.

CONCLUSION

Exteriorization of the uterus for repair is associated with an increased incidence of nausea and vomiting and tachycardia during cesarean delivery under spinal anesthesia. Uterine repair should be done in situ where possible.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, www.clinicaltrials.gov, NCT00452972

LEVEL OF EVIDENCE

I.

Safety profile of morphine following surgery in neonates

OBJECTIVE

To determine the effect of morphine on duration of mechanical ventilation, apnoea and hypotension among full-term neonates who underwent thoracic or abdominal surgery in a level III neonatal intensive care unit.

METHOD

Medical records of 82 infants were reviewed retrospectively and data including patient demographics, clinical diagnosis, type of surgery, postoperative opioid administration, duration of mechanical ventilation, hypotension, apnoea and pain scores (premature infant pain profile (PIPP) score) were collected.

RESULT

Sixty-two neonates (76%) received morphine following surgery as a continuous intravenous infusion during the postoperative period. Linear regression analysis showed that morphine dosage and duration were significantly associated with the duration of mechanical ventilation. An increase in morphine infusion rate by 10 microg kg(-1) h(-1) was associated with an increase in the duration of mechanical ventilation by 24 h (P<0.0001) and an increase in morphine duration of 1 hour was associated with a longer duration of mechanical ventilation by 38 min (P<0.0001). Logistic regression analysis showed no association between morphine infusion rate or duration and hypotension. Apnoea was not associated with morphine dosage or duration of infusion in neonates receiving morphine following extubation. Score on the PIPP correlated significantly with morphine infusion rate across time (r=0.47, P<0.01).

CONCLUSION

Postoperative morphine dose and duration may prolong the duration of mechanical ventilation but there are no significant dose-dependent effects on other parameters including apnoea or hypotension following extubation in term neonates. More research is needed to determine the safety profile of morphine for management of pain in non-ventilated neonates.

Usefulness of a placental profile in high-risk pregnancies

OBJECTIVE

Test the hypothesis that a placental function profile can reassure most high-risk women with normal test results yet accurately can identify a subset of women who are destined for major complications that will be attributable to placental disease.

STUDY DESIGN

This was a prospective study of 212 high-risk pregnancies that used the placental profile (16- to 18-week maternal serum screening, 18- to 23-week uterine artery Doppler imaging, and placental morphologic condition). Odds ratios (95% CI) were derived for intrauterine fetal death (IUFD), preterm delivery at < 34 weeks of gestation, preeclampsia/hemolysis, elevated liver enzymes, and low platelet count syndrome (HELLP) syndrome, small for gestational age delivery, and early-onset intrauterine growth restriction (IUGR); all normal test results (n =125) were compared with > or = 1 abnormal test results.

RESULTS

The odds of the development of adverse outcomes were significantly less in women with all normal test results (preeclampsia/HELLP [odds ratio, 0.2; 95% CI, 0.1-0.4]), preterm delivery (odds ratio, 0.1; 95% CI, 0.06-0.3), small for gestational age delivery (odds ratio, 0.2; 95% CI, 0.09-0.3), early-onset IUGR (0), and IUFD (odds ratio, 0.05 [0.01-0.2]). Combining those women with two (n = 21) of 3 (n = 15) abnormal test results together predicted 14 of 19 severe IUGR and 15 of 22 IUFD cases.

CONCLUSION

This placental function profile at 16-23 weeks of gestation can reassure women with normal test results by identifying a smaller subset of women who are at reduced risk of perinatal morbidity or death from severe IUGR.

A Randomized Controlled Trial of a Bedside Partogram in the Active Management of Primiparous Labour

OBJECTIVE

The partogram is a pictorial representation of the progress of labour, used in an effort to enhance early recognition of dystocia and help avoid Caesarean section (CS). The objective of this study was to evaluate the effect of partogram use on the CS and obstetric intervention rates.

METHODS

We conducted a randomized controlled trial of use of the partogram in 1932 primiparous women with uncomplicated pregnancies at term. Patients were randomly assigned to one of two groups: the standard group, who had the progress of labour charted in written notes, or the partogram group, whose progress in labour was recorded using a bedside graphical partogram as well as in written notes. Outcomes were stratified according to whether labour was spontaneous or induced and whether membranes were initially intact or ruptured. The primary outcome was the rate of CS; secondary outcome measures were rates of obstetric intervention for dystocia.

RESULTS

There was no significant difference between the groups in rates of CS (partogram 24%, standard notes 25%), rates of other interventions, amniotomy, oxytocin use, or the mean cervical dilatation in labour.

CONCLUSION

In this study, the use of a partogram without a mandatory management of labour protocol had no effect on rates of CS or other intrapartum interventions in healthy primiparous women at term.

Intrathecal plainvs hyperbaric bupivacaine for labour analgesia: efficacy and side effects

PURPOSE

Baricity is an important determinant of block characteristics of the spinal component of a combined spinal epidural (CSE) for labour analgesia. This study compares the analgesic efficacy and side effects of intrathecally administered plain and hyperbaric bupivacaine (both with fentanyl) during active labour.

METHODS

Sixty-two women in active labour (cervical dilatation >or=5 cm and pain score > 5) were randomized in a prospective, single-blinded fashion to receive 2.5 mg of either hyperbaric or plain bupivacaine both combined with 15 microg of fentanyl as the spinal component of a CSE. The primary outcome was failure of satisfactory analgesia within ten minutes of the intrathecal injection as defined by a verbal pain score > 3. Secondary outcomes included need for rescue analgesia, hypotension, respiratory depression, nausea and vomiting, pruritus and sustained fetal bradycardia.

RESULTS

Sixty patients were analyzed. The failure rates were 20% in the hyperbaric group vs 0% in the plain group (P=0.024). The plain solution provided faster onset, higher sensory levels and less motor block at all times during the first 30 min. The incidence of both pruritus and sustained fetal bradycardia was 33% in the plain group and 10% in the hyperbaric group (P=0.03).

CONCLUSION

A plain rather than hyperbaric solution of bupivacaine 2.5 mg with fentanyl 15 microg provides a faster onset of analgesia, higher sensory levels and less motor block, while demonstrating an increased incidence of pruritus and sustained fetal bradycardia.

Minimum Oxytocin Dose Requirement After Cesarean Delivery for Labor Arrest

OBJECTIVE

To estimate the minimum effective intravenous dose of oxytocin required for adequate uterine contraction after cesarean delivery for labor arrest.

METHODS

A randomized single-blinded study was undertaken in 30 parturients undergoing cesarean deliveries under epidural anesthesia for labor arrest despite intravenous oxytocin augmentation. Oxytocin was administered as a slow intravenous bolus immediately after delivery of the infant, according to a biased coin up-down sequential allocation scheme. After assisted spontaneous delivery of the placenta, the obstetrician, blinded to the oxytocin dose, assessed uterine contraction as either satisfactory or unsatisfactory. Additional boluses of oxytocin were administered as required, followed by a maintenance infusion. Data were interpreted and analyzed by a logistic regression model at 95% confidence intervals.

RESULTS

All patients received oxytocin infusions at a mean +/- standard deviation of 9.8 +/- 6.3 hours before cesarean delivery (maximum infusion dose 10.3 +/- 8.2 mU/min). The minimum effective dose of oxytocin required to produce adequate uterine response in 90% of women (ED90) was estimated to be 2.99 IU (95% confidence interval 2.32-3.67). The estimated blood loss was 1,178 +/- 716 mL.

CONCLUSION

Women requiring cesarean delivery for labor arrest after oxytocin augmentation require approximately 3 IU rapid intravenous infusion of oxytocin to achieve effective uterine contraction after delivery. This dose is 9 times more than previously reported after elective cesarean delivery in nonlaboring women at term, suggesting oxytocin receptor desensitization from exogenous oxytocin administration during labor. Therefore, alternative uterotonic agents, rather than additional oxytocin, may achieve superior uterine contraction and control of blood loss during cesarean delivery for labor arrest.

LEVEL OF EVIDENCE

I.

Fetal response to maternal exercise in pregnancies with uteroplacental insufficiency

OBJECTIVE

The purpose of this study was to determine the fetal response to submaximal maternal exercise at 22 to 26 weeks in pregnancies with abnormal uterine artery Doppler.

STUDY DESIGN

This was a prospective comparison of singleton pregnancies with uteroplacental vascular insufficiency (UPVI) (mean uterine pulsatility index [PI] values >1.45 [n = 12]) and those with normal uterine artery Doppler (n = 23). Maternal and fetal cardiovascular responses to 5 minutes of steady state cycling at 10% and at 15% of predicted work rate maximum were studied.

RESULTS

Umbilical artery Doppler deteriorated after exercise in patients with UPVI (pre PI 1.4 [0.35-2.14], post PI 1.64 [0.45-2.18]). Three (25%) had transient absent-end diastolic flow (AEDF) in umbilical artery, 2 of which developed early-onset intrauterine growth restriction (IUGR) with AEDF. Fetal cardiac output studies remained stable during the examinations.

CONCLUSION

Submaximal steady state exercise had a transient deleterious effect in a subset of women with uteroplacental vascular insufficiency destined to develop early-onset IUGR.

Agreement of carbon dioxide levels measured by arterial, transcutaneous and end tidal methods in preterm infants < or = 28 weeks gestation

OBJECTIVE

To assess the agreement of transcutaneous carbon dioxide (TcPCO(2)) and end tidal carbon dioxide (PetCO(2)) with arterial carbon dioxide (PaCO(2)) values in infants < 28 weeks gestational age.

STUDY DESIGN

In all, 27 ventilated preterm infants were prospectively studied. PaCO(2) was compared with TcPCO(2) and PetCO(2) measured at three similar time points within first 24 hours after birth.

RESULTS

The Intraclass correlation coefficients for TcPCO(2) and PaCO(2) were 0.45, 0.73 and 0.53; and for PetCO(2) and PaCO(2) were 0.61, 0.56 and 0.57 at 4, 12 and 24 hours after birth, respectively.

CONCLUSION

A moderate agreement with a wide variation in individual values was observed between noninvasive methods and PaCO(2) in preterm infants in the first 24 hours. Noninvasive monitoring methods cannot be substituted for PaCO(2) analyses in preterm infants during this critical period.

Genome-wide linkage analysis of systolic blood pressure slope using the Genetic Analysis Workshop 13 data sets

Systolic blood pressure (SBP) is an age-dependent complex trait for which both environmental and genetic factors may play a role in explaining variability among individuals. We performed a genome-wide scan of the rate of change in SBP over time on the Framingham Heart Study data and one randomly selected replicate of the simulated data from the Genetic Analysis Workshop 13. We used a variance-component model to carry out linkage analysis and a Markov chain Monte Carlo-based multiple imputation approach to recover missing information. Furthermore, we adopted two selection strategies along with the multiple imputation to deal with subjects taking antihypertensive treatment. The simulated data were used to compare these two strategies, to explore the effectiveness of the multiple imputation in recovering varying degrees of missing information, and its impact on linkage analysis results. For the Framingham data, the marker with the highest LOD score for SBP slope was found on chromosome 7. Interestingly, we found that SBP slopes were not heritable in males but were for females; the marker with the highest LOD score was found on chromosome 18. Using the simulated data, we found that handling treated subjects using the multiple imputation improved the linkage results. We conclude that multiple imputation is a promising approach in recovering missing information in longitudinal genetic studies and hence in improving subsequent linkage analyses.

A test of linkage for complex discrete and continuous traits in nuclear families

This article presents a score test for genetic linkage in nuclear families which applies to any trait having a distribution belonging to the exponential family, which includes binary and normal distributions, and distributions which are skewed or have nonnormal kurtosis. The specific distribution need not be specified and the method applies to sibships of arbitrary size. Tests of complex genetic effects are given, including unspecified mode of inheritance or additive, dominant, overdominant, and recessive modes of inheritance, covariates, multiple-locus models, including gene-gene interactions, and gene-environment interactions. The relation of our method to the Haseman-Elston methods is studied theoretically and by simulation.

Interaction of a low mobility group protein, LMG160, with deoxyribonucleic acid

A fraction of low mobility group (LMG) nonhistone protein designated LMG(160) was isolated from rat liver chromatin by preparative gel electrophoresis and its interaction with DNA was studied using thermal denaturation and DNA-cellulose affinity chromatography techniques. The results showed that LMG(160) with an isoelecteric point of 5-5.5 was bound to DNA and decreased its melting temperature. Increasing ionic strengths decreased this effect. DNA-cellulose affinity chromatography showed the affinity of LMG(160) to double stranded DNA was higher than that to single stranded DNA, since it required 0.6 M NaCl for elution. The results suggest that LMG(160) protein preferentially binds to double stranded DNA destabilizes it and the binding is electrostatic.

Modeling complex disease with demographic and environmental covariates and a candidate gene marker

We randomly chose replicates 28 and 29 of the simulated data sets of Genetic Analysis Workshop 12 to model the dependence of affection status on covariates, quantitative traits, and genes using all living pedigree members. First we explored the relationship of affection status to demographic and environmental factors using logistic regression and the Cox proportional hazards models. In the second stage of our analyses the generalized transmission disequilibrium test (GTDT) was applied to nuclear families with at least two affected siblings to select single markers and high-risk alleles, which were tested in the population association analyses including all pedigree members. Multiple logistic regression models were fitted to investigate the joint contributions of genetic and nongenetic factors and a block-recursive modeling approach was adopted to study inherent hierarchical dependence structure in the data. We found that allele 2 on marker 35 of chromosome 6 is associated with higher risk compared with the other 3 alleles of this marker. In addition to this significant genetic effect, age at exam and four of the five quantitative traits (QT1, QT2, QT4, and QT5) had a significant association with the disease. Our results were obtained without knowledge of the true disease generating models.

Evaluation of the contribution of environmental factors

For the simulated data of GAW11, the roles of two environmental factors, E1 and E2, were investigated. Logistic regression analyses measuring the association between outcome (either mild or severe disease versus no disease) and E1 and E2 exposure indicated that E1 was a risk factor for disease (either mild or severe) but that E2 was not associated with outcome. Linkage analyses were performed for strata defined by E1 and E2 exposure. A specific disease locus was identified in these stratified analyses where this locus would not have been identified with an unstratified linkage analysis. Finally, stratified generalized transmission disequilibrium test analyses yielded several false positive results.

A comparison of some allele-sharing based linkage analysis methods for detecting complex trait loci

Using randomly selected sib pairs from a subset of the GAW11 simulated data in Problem 2, we compared the results of some linkage analysis methods based on allele sharing. One method was the Haseman-Elston test for a binary disease outcome (unaffected vs. mild or severe). The other methods, which analyzed the trinary ordered outcome unaffected/mild/severe were the Haseman-Elston test, an extended Haseman-Elston incorporating sib-pair sums, variance components analysis, and regression analysis. Our analysis was done without knowledge of the generating model.