Transnational prenatal care among migrant women from low-and-middle-income countries who gave birth in Montreal, Canada

OBJECTIVES

There is little research examining transnational prenatal care (TPC) (i.e., prenatal care in more than one country) among migrant women. Using data from the Migrant-Friendly Maternity Care (MFMC) - Montreal project, we aimed to: (1) Estimate the prevalence of TPC, including TPC-arrived during pregnancy and TPC-arrived pre-pregnancy, among recently-arrived migrant women from low- and middle-income countries (LMICs) who gave birth in Montreal, Canada; (2) Describe and compare the socio-demographic, migration and health profiles and perceptions of care during pregnancy in Canada between these two groups and migrant women who received no TPC (i.e., only received prenatal care in Canada); and (3) Identify predictors of TPC-arrived pre-pregnancy vs. No-TPC.

METHODS

The MFMC study used a cross-sectional design. Data were gathered from recently-arrived (< 8 years) migrant women from LMICs via medical record review and interview-administration of the MFMC questionnaire postpartum during the period of March 2014-January 2015 in three hospitals, and February-June 2015 in one hospital. We conducted a secondary analysis (n = 2595 women); descriptive analyses (objectives 1 & 2) and multivariable logistic regression (objective 3).

RESULTS

Ten percent of women received TPC; 6% arrived during pregnancy and 4% were in Canada pre-pregnancy. The women who received TPC and arrived during pregnancy were disadvantaged compared to women in the other two groups (TPC-arrived pre-pregnancy and No-TPC women), in terms of income level, migration status, French and English language abilities, access barriers to care and healthcare coverage. However, they also had a higher proportion of economic migrants and they were generally healthier compared to No-TPC women. Predictors of TPC-arrived pre-pregnancy included: 'Not living with the father of the baby' (AOR = 4.8, 95%CI 2.4, 9.8), 'having negative perceptions of pregnancy care in Canada (general experiences)' (AOR = 1.2, 95%CI 1.1, 1.3) and younger maternal age (AOR = 1.1, 95%CI 1.0, 1.1).

CONCLUSION

Women with more capacity may self-select to migrate during pregnancy which results in TPC; these women, however, are disadvantaged upon arrival, and may need additional care. Already-migrated women may use TPC due to a need for family and social support and/or because they prefer the healthcare in their home country.

Validation of the Student-Rated Parental School Involvement Questionnaire: Factorial Validity and Invariance Across Time and Sociodemographic Characteristics

Studies highlighting the importance of parental involvement in schooling have multiplied over the past years. However, well-validated tools assessing the different dimensions of parental involvement are lacking, especially when addressing young students’ perception of their parents’ involvement. This study offers a preliminary validation of the Student-Rated Parental School Involvement Questionnaire (SR-PSIQ); factor structure, measurement invariance, and predictive validity were assessed. Data collected on four measurement occasions from 923 French-Canadian primary school students was used. Results favored a four-factor model (parental expectations, parent–child communication, homework supervision, and school-based involvement). The SR-PSIQ was invariant across time, student gender, parental immigration status, and socioeconomic status. Regarding predictive validity, all dimensions of parental involvement were associated with later student engagement. Overall, the SR-PSIQ is a brief, valid, and reliable instrument that can easily be used by researchers or partitioners who want to understand how parents are involved in their child’s schooling.

Development and pretest of key visual imagery in a campaign for the prevention of child maltreatment

INTRODUCTION

This article discusses the development and pretesting of key visual imagery in a promotional campaign developed in Quebec, Canada. This campaign is the media-based component of a broader prevention strategy involving the use of the Triple P program (Sanders, 1999).

OBJECTIVES

The purpose was to pretest with parents the preliminary version of a poster that uses the campaign's key visual imagery prior to final production.

METHOD

In total, 26 parents from the regions of Quebec City and Montreal participated in four focus groups.

RESULTS

Two general themes emerged from the focus groups: (i) emotions and reactions arising from the key visual imagery; and (ii) comprehension of the message being conveyed.

CONCLUSION

Based on this information, recommendations were made to the marketing agency, which then modified the campaign's key visual imagery and proposed a final layout.

How Internally Coupled Ears Generate Temporal and Amplitude Cues for Sound Localization

In internally coupled ears, displacement of one eardrum creates pressure waves that propagate through air-filled passages in the skull and cause displacement of the opposing eardrum, and conversely. By modeling the membrane, passages, and propagating pressure waves, we show that internally coupled ears generate unique amplitude and temporal cues for sound localization. The magnitudes of both these cues are directionally dependent. The tympanic fundamental frequency segregates a low-frequency regime with constant time-difference magnification from a high-frequency domain with considerable amplitude magnification.

Temporal precision and reliability in the velocity regime of a hair-cell sensory system: the mechanosensory lateral line of goldfish, Carassius auratus

Fish and aquatic frogs detect minute water motion by means of a specialized mechanosensory system, the lateral line. Ubiquitous in fish, the lateral-line system is characterized by hair-cell based sensory structures across the fish's surface called neuromasts. These neuromasts occur free-standing on the skin as superficial neuromasts (SN) or are recessed into canals as canal neuromasts. SNs respond to rapid changes of water velocity in a small layer of fluid around the fish, including the so-called boundary layer. Although omnipresent, the boundary layer's impact on the SN response is still a matter of debate. For the first time using an information-theoretic approach to this sensory system, we have investigated the SN afferents encoding capabilities. Combining covariance analysis, phase analysis, and modeling of recorded neuronal responses of primary lateral line afferents, we show that encoding by the SNs is adequately described as a linear, velocity-responsive mechanism. Afferent responses display a bimodal distribution of opposite Wiener kernels that likely reflected the two hair-cell populations within a given neuromast. Using frozen noise stimuli, we further demonstrate that SN afferents respond in an extremely precise manner and with high reproducibility across a broad frequency band (10-150 Hz), revealing that an optimal decoder would need to rely extensively on a temporal code. This was further substantiated by means of signal reconstruction of spike trains that were time shifted with respect to their original. On average, a time shift of 3.5 ms was enough to diminish the encoding capabilities of primary afferents by 70%. Our results further demonstrate that the SNs' encoding capability is linearly related to the stimulus outside the boundary layer, and that the boundary layer can, therefore, be neglected while interpreting lateral line response of SN afferents to hydrodynamic stimuli.

The mechanisms for compression and reflection of cortical waves

Waves are common in cortical networks and may be important for carrying information about a stimulus from one local circuit to another. In a recent study of visually evoked waves in rat cortex, compression and reflection of waves are observed as the activation passes from visual areas V1 to V2. The authors of this study apply bicuculline (BMI) and demonstrate that the reflection disappears. They conclude that inhibition plays a major role in compression and reflection. We present several models for propagating waves in heterogeneous media and show that the velocity and thus compression depends weakly on inhibition. We propose that the main site of action of BMI with respect to wave propagation is on the threshold for firing which we suggest is related to action on potassium channels. We combine numerical and analytic methods to explore both compression and reflection in an excitable system with synaptic coupling.

Coding of Stimuli by Ampullary Afferents in Gnathonemus petersii

Weakly electric fish use electroreception for both active and passive electrolocation and for electrocommunication. While both active and passive electrolocation systems are prominent in weakly electric Mormyriform fishes, knowledge of their passive electrolocation ability is still scarce. To better estimate the contribution of passive electric sensing to the orientation toward electric stimuli in weakly electric fishes, we investigated frequency tuning applying classical input-output characterization and stimulus reconstruction methods to reveal the encoding capabilities of ampullary receptor afferents. Ampullary receptor afferents were most sensitive (threshold: 40 μV/cm) at low frequencies (<10 Hz) and appear to be tuned to a mix of amplitude and slope of the input signals. The low-frequency tuning was corroborated by behavioral experiments, but behavioral thresholds were one order of magnitude higher. The integration of simultaneously recorded afferents of similar frequency-tuning resulted in strongly enhanced signal-to-noise ratios and increased mutual information rates but did not increase the range of frequencies detectable by the system. Theoretically the neuronal integration of input from receptors experiencing opposite polarities of a stimulus (left and right side of the fish) was shown to enhance encoding of such stimuli, including an increase of bandwidth. Covariance and coherence analysis showed that spiking of ampullary afferents is sufficiently explained by the spike-triggered average, i.e., receptors respond to a single linear feature of the stimulus. Our data support the notion of a division of labor of the active and passive electrosensory systems in weakly electric fishes based on frequency tuning. Future experiments will address the role of central convergence of ampullary input that we expect to lead to higher sensitivity and encoding power of the system.

Social-economic status and rates of hospital admission for chronic disease in urban Canada

Socio-economic status (SES) is recognized as an important factor that influences the utilization of health-care services. We set out to explore this association in the context of hospital admissions for the treatment of ambulatory care sensitive conditions (ACSCs)--chronic conditions normally managed on an outpatient basis. We examined rates of hospital admission for the treatment of ACSCs overall and for three specific conditions: chronic obstructive pulmonary disease (COPD), diabetes and asthma in children. Data were obtained from the Canadian Institute for Health Information, the Institut national de santé du Québec, and Statistics Canada. SES was determined using a measure known as the Deprivation Index, applied at the level of the census dissemination area (DA), the smallest geographical unit for which population statistics are available. This study accounted for 46,173 urban DAs classified into low, average and high SES groups. Statistically significant variations in rates of hospital admission were found across the three SES groups for all four ACSC categories examined. For example, hospital admission rates for COPD and diabetes in the low SES group were about 3.0 and 2.7 times higher, respectively, than those in the high SES group. Further research is needed to understand the mechanisms and underlying causes of higher rates of hospital admission for the treatment of chronic disease among people with low SES.

Wake tracking and the detection of vortex rings by the canal lateral line of fish

Research on the lateral line of fish has mainly focused on the detection of oscillating objects. Yet many fish are able to track vortex wakes that arise from other fish. It is not yet known what the sensory input from a wake looks like and how fish can extract relevant information from it. We present a mathematical model to determine how vortices stimulate the canal lateral line and verify it by neuronal recordings. We also show how the information about the orientation of a vortex ring is captured by the lateral-line sensors so as to enable fish to follow a vortex street.

A nutritional intervention promoting a Mediterranean food pattern does not affect total daily dietary cost in North American women in free-living conditions

The purpose of this study was to evaluate the impact of adopting a Mediterranean diet on dietary cost and energy density in free-living conditions. The 12-wk nutritional intervention consisted of 2 group courses and 7 individual sessions with a dietician in a sample of 73 healthy women. To evaluate the dietary response to the nutritional intervention, a registered dietician administered a FFQ at 0, 6, 12, and 24 wk. Total daily dietary cost was calculated using a price list including all items from the FFQ. Our findings indicated that daily energy cost evaluated at wk 12 vs. wk 0 [1046 +/- 217 vs. 967 +/- 192 kJ/Canadian dollars (CAN$), respectively, P = 0.18] and total daily dietary cost (8.61 +/- 2.13 vs. 8.75 +/- 2.50 CAN$/d per participant, respectively, P = 0.58) did not change. Total daily energy density at wk 12 decreased compared with wk 0 (2.56 +/- 0.76 vs. 2.20 +/- 0.67 kJ/g; P < 0.0001). Adherence to the Mediterranean diet led to increased cost related to vegetables, fruits, legumes, nuts and seeds, canola/olive oil, whole grains, poultry, and fish (P < or = 0.01) and to reduced dietary cost for red meat, refined grains, desserts and sweets, and fast food (P < or = 0.008). In conclusion, these data suggest that adherence to a nutritional intervention program promoting the Mediterranean food pattern is not associated with increased daily dietary cost or energy cost but led to a reduction in energy density. Consequently, increased cost should not be considered a barrier to the promotion and adoption of a Mediterranean diet.

Factors influencing the dietary response to a nutritional intervention promoting the Mediterranean food pattern in healthy women from the Quebec City metropolitan area

The purpose of this study was to evaluate the influence of sociodemographic characteristics and baseline food habits on the dietary response to a nutritional intervention promoting the Mediterranean food pattern and maintenance of dietary modifications in 73 healthy women. The 12-week nutritional intervention in free-living conditions consisted of two group courses and seven individual sessions with a dietitian. A follow-up visit was performed 12 weeks after the end of the intervention (week 24). A Mediterranean dietary score was derived from a food frequency questionnaire, administered at 0, 6, 12 and 24 weeks. Marital status, socioeconomic level, educational level and household size did not seem to influence the dietary response, whereas women without children followed more closely dietary advice than women with children (OR, 3.6; 95% CI, 1.3-10.0). Planning food purchases in function of weekly discounts was also associated with better dietary response to the intervention (OR, 3.3; 95% CI, 1.3-8.8). Nutritional intervention promoting the Mediterranean food pattern was effective in modifying food habits of healthy women. The fact of having children or not and food purchase habits seem to influence the response to a nutritional intervention promoting the Mediterranean food pattern.

Effect of a nutritional intervention promoting the Mediterranean food pattern on electrophoretic characteristics of low-density lipoprotein particles in healthy women from the Québec City metropolitan area

The objective of the present study was to evaluate the effect of a nutritional intervention promoting the Mediterranean food pattern in free-living conditions on LDL electrophoretic characteristics in a group of seventy-one healthy women, aged between 30 and 65 years. The 12-week nutritional intervention consisted of two courses on nutrition and seven individual sessions with a dietitian. The first course provided information on the Mediterranean food pattern and the second was a cooking lesson. LDL peak particle diameter (LDL-PPD) and cholesterol levels in small (LDL-cholesterol<255?Å) and large LDL fractions (LDL-cholesterol>260?Å) were obtained by 2–16% polyacrylamide gel electrophoresis of whole plasma. The sample was divided on the basis of baseline LDL-PPD using tertiles of the distribution (258·4 Å and 260·0 Å). Among the total sample of women, no significant change in LDL-PPD was observed in response to the nutritional intervention. However, subjects who at baseline were in the first tertile of the LDL-PPD distribution (>258·4 Å) showed a significant increase in LDL-PPD and in the proportion of LDL%>260?%uest;Åin response to the 12-week nutritional intervention (P>0·05). In contrast, LDL-PPD decreased significantly (P=0·007) among women with large LDL particles at baseline (LDL-PPD >260 Å) while the proportion of LDL%<255 Åand of LDL%>260 Åremained unchanged. To conclude, changes in the food pattern, in response to a nutritional intervention promoting the Mediterranean food pattern, were accompanied by beneficial modifications in LDL electrophoretic characteristics in women who were characterised at baseline by smaller LDL particles.

Effect of a nutritional intervention promoting the Mediterranean food pattern on anthropometric profile in healthy women from the Québec city metropolitan area

OBJECTIVE

To evaluate the impact of a nutritional intervention promoting a Mediterranean food pattern on anthropometric profile in healthy women.

DESIGN

Nutritional intervention study.

SETTING

Laval University, Canada.

SUBJECTS

Seventy-seven healthy women started the study and four did not complete the study.

METHODS

A 12-week nutritional intervention in free-living conditions consisted of two group courses on nutrition and seven individual sessions with a dietitian. A follow-up visit was performed 12 weeks after the end of the intervention (week 24). A Mediterranean dietary score (MedScore), based on the 11 components of the Mediterranean pyramid, was established to evaluate the adherence to the Mediterranean food pattern.

RESULTS

Small but significant decreases in body weight and waist circumference were observed after 12 weeks of intervention (0.5 kg and 1.2 cm, respectively (P<0.01)). Increase in partial MedScore for legumes, nuts and seeds (increase in consumption) as well as increase in partial MedScore for sweets (decrease in consumption) were significantly associated with changes in waist circumference (r=-0.36, P=0.001; r=0.24, P=0.05, respectively). No association was observed between changes in anthropometric profile and changes in the consumption of olive oil.

CONCLUSION

Changes in dietary food pattern, more specifically an increase in the consumption of legumes, nuts and seeds, and a decrease in the consumption of sweets, were associated with some beneficial changes in anthropometric profile.

A nutritional intervention promoting the Mediterranean food pattern is associated with a decrease in circulating oxidized LDL particles in healthy women from the Québec City metropolitan area

The aim of the present study was to evaluate the effect of a nutritional intervention promoting the Mediterranean food pattern under free-living conditions on circulating oxidized LDL (ox-LDL) in a group of 71 healthy women from the Quebec City metropolitan area. The 12-wk nutritional intervention consisted of 2 courses on nutrition and 7 individual sessions with a dietitian. A score based on the 11 components of the Mediterranean pyramid was established to determine the women's adherence to the Mediterranean food pattern. Plasma ox-LDL concentrations were measured by a monoclonal antibody mAb-4E6-based competition ELISA. Among all women, plasma ox-LDL decreased by 11.3% after 12 wk of nutritional intervention (P < 0.0001) despite a lack of change in plasma LDL cholesterol (LDL-C). Also, an increase in the Mediterranean dietary score was significantly correlated with a decrease in ox-LDL concentrations (r = -0.30; P = 0.01). More specifically, increases in servings of fruits (r = -0.25; P < 0.05) and vegetables (r = -0.24; P < 0.05) were associated with decreases in ox-LDL concentrations. Changes in the food pattern in response to a nutritional intervention promoting the Mediterranean food pattern were accompanied by beneficial effects in circulating ox-LDL concentrations in healthy women.

Validity and reproducibility of an interviewer-administered food frequency questionnaire for healthy French-Canadian men and women

Objective

To evaluate the validity (study 1) and the reproducibility (study 2) of an interviewer-administered food frequency questionnaire (FFQ).

Method

The FFQ was designed at Laval University and contains 91 items and 33 subquestions. Study 1: The FFQ was compared against a 3-day food record (2 week-days and 1 weekend-day), at week 0, 6 and 12 of a nutritional intervention. Study 2: In order to evaluate the reproducibility of the FFQ, 2 registered dietitians administered the FFQ 4-weeks apart among subjects who were not part of the nutritional intervention.

Results

Study 1: Mean values for intake of most nutrients assessed by the FFQ and by the 3-day food record were not statistically different. Energy-adjusted correlation coefficients for major macronutrients ranged from 0.36 for proteins to 0.60 for carbohydrates (p ≤ 0.01). Agreement analysis revealed that on average, 35% of the subjects were classified in the same quartile when nutrients were assessed by either the 3-day food record or the FFQ. Study 2: Significant associations were observed between dietary measurements derived from the two FFQs administered 4 weeks apart. Correlation coefficients for the reproducibility of macronutrients ranged from 0.66 for carbohydrates to 0.83 for lipids after energy adjustment. On average, 46% of the subjects were classified in the same quartile when nutrient intakes were assessed by either FFQ.

Conclusion

These data indicated that the FFQ developed has a good validity and is reproducible.

Effect of a nutritional intervention promoting the Mediterranean food pattern on plasma lipids, lipoproteins and body weight in healthy French-Canadian women

The present study examined the effect of a nutritional intervention promoting the Mediterranean food pattern in uncontrolled 'real life' conditions among a group of 77 French-Canadian women. The principal objective was to document changes in the plasma lipid-lipoprotein profile and in body weight that occurred in response to the intervention. The 12-week nutritional intervention included two group sessions, three individual sessions and four 24-h recalls (phone interview) with a registered dietitian. A score based on the 11 components of the Mediterranean pyramid, ranging from 0 to 44 points, was established to evaluate the adhesion to the Mediterranean food pattern. The Mediterranean score increased from 21.1+/-3.6 at baseline to 28.6+/-4.4 after 6 weeks of intervention (P<0.0001) with no further increase at week 12. Small but significant decreases in total cholesterol and apolipoprotein B (apoB) as well as in body mass index (BMI) were observed after 6 weeks of intervention. No significant change in plasma concentrations of high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and triglycerides (TG) were observed in response to the nutritional intervention. In conclusion, a nutritional intervention program promoting the Mediterranean food pattern was effective in modifying food habits of healthy women from the Québec City metropolitan area and resulted in small but significant effects on specific cardiovascular risk factors.

New competition in the realm of renin-angiotensin axis inhibition; the angiotensin II receptor antagonists in congestive heart failure

OBJECTIVE

To critically review the studies comparing angiotensin II (AgII) receptor antagonists with placebo or angiotensin-converting enzyme (ACE) inhibitors in patients with congestive heart failure (CHF).

DATA SOURCES

A MEDLINE search (1988 to January 2000) was used to identify pertinent literature. Additional references were also retrieved from selected articles.

STUDY SELECTION

As most published CHF studies were performed with candesartan and losartan, these agents are the main focus of this article. However, all identified comparative clinical studies were reviewed and included, regardless of the agent used.

DATA SYNTHESIS

AgII receptor antagonists inhibit the effects of AgII at its sub-type 1 receptor, independently of AgII's synthesis pathway. They present a hemodynamic profile similar to that of ACE inhibitors, without reflex neurohormonal activation. They have been shown to be at least as effective as ACE inhibitors in improving symptoms, exercise capacity, and New York Heart Association functional class in CHF patients. Although the ELITE (Evaluation of Losartan in the Elderly) trial suggested that losartan improved survival compared with captopril, this study was not designed to look at mortality. ELITE-II, an adequately powered study, showed no difference in mortality rates between patients taking captopril and those taking losartan. The combination of AgII receptor antagonists and ACE inhibitors provides additional benefit on blood pressure lowering and prevention of ventricular remodeling. AgII receptor antagonists are well tolerated, with an incidence of adverse effects similar to or lower than that of ACE inhibitors. Their lack of effect on bradykinin degradation might explain their lower incidence of cough.

CONCLUSIONS

The data cumulated thus far in patients with CHF highlight that ACE inhibitors must remain the treatment of choice and that AgII receptor antagonists may be considered as an acceptable alternative for patients who are intolerant to ACE inhibitors.

Antiretroviral prophylaxis of health care workers at two urban medical centers

We examined the influence of job category, source patient HIV status, and exposure type as predictors of whether health care workers initiated antiretroviral prophylaxis after potential blood-borne pathogen exposures. Of 639 exposures over an 18-month period, 82 individuals (13%) elected to receive prophylaxis, of whom 66% took medications for fewer than 96 hours and 12% completed a 4-week course. Reasons for early drug discontinuation included confirmation of source patient HIV-negative serological status (65%), gastrointestinal side effects (13%), headache (4%), and personal decision after counseling/other input (18%). Individuals exposed to HIV-positive source patients were more likely to initiate prophylaxis (odds ratio [OR], 5.1; 95% confidence interval [CI] 2.6 to 9.9). Licensed nurses were less likely than others to accept prophylaxis (OR, 0.5; 95% CI, 0.3 to 0.8), whereas physicians and medical students were more likely to accept prophylaxis (OR, 1.9; 95% CI, 1.1 to 3.3).

Effect of branch position and light availability on shoot growth of understory sugar maple and yellow birch saplings

Phenotypic plasticity enables tree saplings to change their morphology according to their environment to grow toward a better light micro-habitat. Therefore, processes of crown development could be expected to vary as a function of light. The objectives of this study were to (i) evaluate the effects of position and light availability on shoot growth within the crowns of understory saplings of sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britton.); (ii) develop a new vigour index for shoots; and (iii) evaluate the possible factors relating to branch mortality in the crown of sugar maple saplings. The results revealed that there is a clear branch position effect on shoot growth in the crown for yellow birch saplings and that it is partly related to the presence of two types of shoots. Dead branches were located at the bottom of the crown of sugar maple saplings; they were smaller in size, had wider angles and had lower indexes of vigour than live branches found nearby. Preliminary results obtained on the vigour index indicate that it is a potentially useful tool for predicting the growth and vigour status of a branch.Key words: shoot growth, branch position, light availability, branch mortality, sugar maple, yellow birch.

Biomechanical evaluation of calcium phosphate cement-augmented fixation of unstable intertrochanteric fractures

OBJECTIVE

The purpose of this study was to evaluate the mechanical effects of using an injectable calcium phosphate cement, Norian Skeletal Replacement System (SRS), which is replaced by the native remodeling process, to augment sliding hip screw fixation of unstable intertrochanteric fractures in a cadaver model.

DESIGN

Ten matched pairs of human cadaver femora were used. One randomly selected femur from each pair was designated as experimental, whereas the contralateral femur served as the control.

SETTING

Testing was performed in the Orthopaedic Research Laboratories, The University of Michigan, Ann Arbor, Michigan, U.S.A.

PATIENTS/PARTICIPANTS

Femora with no radiographic evidence of pathology and with below-normal bone mineral density in the neck region were accepted into the study.

INTERVENTION

Three-part, intertrochanteric fractures were repaired by using a sliding hip screw and sideplate, without replacement of the posteromedial fragment. In the experimental side of each pair, SRS was used to grout the hip screw and to fill the posteromedial defect.

MAIN OUTCOME MEASUREMENTS

Femora were subjected to simulated single-leg stance loading to approximately one body weight in a servohydraulic testing machine. Measurements of stiffness, medial bone surface strain, hip screw displacement, and sideplate strain were made in fractured femora. Stiffness and medial bone surface strain baseline data were obtained in the intact bone before fracture creation as well.

RESULTS

Augmenting fixation with Norian SRS increased the fracture construct stiffness and minimized sliding hip screw displacement. It also maintained medial bone surface strain closer to the intact state and lowered sideplate strain relative to controls. However, there was no difference in the load to failure between SRS-augmented and control femora.

CONCLUSIONS

SRS augmentation of unstable, intertrochanteric fractures significantly improved overall stability, facilitated load transfer across the fracture, and decreased both shortening of the proximal femur and stress on the sliding hip screw.

Identification of specific EP receptors responsible for the hemodynamic effects of PGE2

To identify the E-prostanoid (EP) receptors that mediate the hemodynamic actions of PGE2, we studied acute vascular responses to infusions of PGE2 using lines of mice in which each of four EP receptors (EP1 through EP4) have been disrupted by gene targeting. In mixed groups of males and females, vasodepressor responses after infusions of PGE2 were significantly diminished in the EP2 -/- and EP4 -/- lines but not in the EP1 -/- or EP3 -/- lines. Because the actions of other hormonal systems that regulate blood pressure differ between sexes, we compared the roles of individual EP receptors in males and females. We found that the relative contribution of each EP-receptor subclass was strikingly different in males from that in females. In females, the EP2 and EP4 receptors, which signal by stimulating adenylate cyclase, mediate the major portion of the vasodepressor response to PGE2. In males, the EP2 receptor has a modest effect, but most of the vasodepressor effect is mediated by the phospholipase C-coupled EP1 receptor. Finally, in male mice, the EP3 receptor actively opposes the vasodepressor actions of PGE2. Thus the hemodynamic actions of PGE2 are mediated through complex interactions of several EP-receptor subtypes, and the role of individual EP receptors differs dramatically in males from that in females. These differences may contribute to sexual dimorphism of blood pressure regulation.

Development of bacterial contamination during production of yeast extracts

Baker's yeast suspensions having bacterial populations of 10(6) and 10(8) CFU/ml were subjected to autolysis processes designed to obtain yeast extracts (YE). The bacterial contaminants added to the yeast cell suspensions were produced with spent broths obtained from a commercial yeast production plant and contained 59% cocci (Leuconostoc, Aerococcus, Lactococcus) as well as 41% bacilli (Bacillus). Autolyses were conducted at four different pH levels (4.0, 5.5, 7.0, and 8.5) and with two autolysis-promoting agents (ethyl acetate and chitosan). Processing parameters were more important than the initial bacterial population in the development of contaminating bacteria during manufacture of YE. Drops in the viable bacterial population after a 24-h autolysis were observed when pH was adjusted to 4.0 or when ethyl acetate was added. A significant interaction was found between the effects of pH and autolysis promoters on the bacterial population in YE, indicating that the activity of ethyl acetate, as opposed to that of chitosan, was not influenced by pH.

Urinary concentrating function in mice lacking EP3 receptors for prostaglandin E2

The actions of prostaglandin (PG) E2 are mediated by four distinct classes of PGE2 E-prostanoid (EP) receptors (EP1 through EP4). However, the in vivo functions of the individual EP receptor subtypes have not been delineated. To study the functions of one of these subtypes, the EP3 receptor, we generated EP3-deficient (-/-) mice by gene targeting. EP3 -/- animals survived in expected numbers, reproduced, and had no obvious abnormalities in their major organ systems. Because the EP3 receptor is expressed at high levels in the renal medulla and cortical collecting duct, and because previous studies have suggested that the EP3 receptor might antagonize the effects of vasopressin in the distal nephron, we examined urinary concentrating functions in EP3 -/- mice. Basal urine osmolality (UOsm) was similar in groups of EP3 -/- and wild-type (EP3 +/+) mice. However, after inhibition of endogenous PGE2 production by indomethacin, UOsm increased significantly in EP3 +/+ but not in EP3 -/- mice. Despite this insensitivity to acute inhibition of prostanoid production, EP3 -/- mice concentrated and diluted their urine normally in response to a series of physiological stimuli. This suggests that PGE2 acts through the EP3 receptor to modulate urinary concentrating mechanisms in the kidney, but these effects are not essential for normal regulation of urinary osmolality.

Familial transmission of substance use disorders

BACKGROUND

There is increasing evidence that substance use disorders are familial and that genetic factors explain a substantial degree of their familial aggregation. To perform a controlled family study of probands with several different predominant drugs of abuse, including opioids, cocaine, cannabis, and/or alcohol.

METHODS

The subjects for the present study included 231 probands with dependence on opioids, cocaine, cannabis, and/or alcohol and 61 control probands, and their 1267 adult first-degree relatives. Diagnostic estimates were based on semistructured diagnostic interviews and/or structured family history interviews regarding each proband, spouse, and adult first-degree relative. The interview data were reviewed blindly and independently by clinicians with extensive experience in the evaluation and treatment of substance use disorders.

RESULTS

There was an 8-fold increased risk of drug disorders among the relatives of probands with drug disorders across a wide range of specific substances, including opioids, cocaine, cannabis, and alcohol, which is largely independent from the familial aggregation of both alcoholism and antisocial personality disorder. There was also evidence of specificity of familial aggregation of the predominant drug of abuse.

CONCLUSIONS

Elevation in risk of this magnitude places a family history of drug disorder as one of the most potent risk factors for the development of drug disorders. These results suggest that there may be risk factors that are specific to particular classes of drugs as well as risk factors that underlie substance disorders in general.

Antimutagenic effects of milk fermented by Lactobacillus helveticus L89 and a protease-deficient derivative

The antimutagenic effects of whey, acetone extracts, and protein fractions isolated from milk that had been fermented by Lactobacillus helveticus L89 were investigated using the mutagen 4-nitroquinoline-N'-oxide in the Ames test (Salmonella typhimurium TA 100). Fermented milk significantly inhibited mutagenesis induced by 4-nitroquinoline-N'-oxide. However, milk fermented by a nonproteolytic variant of the same strain showed no inhibitory effects. Results were similar for the whey fractions and acetone extracts of the fermented milks. After fermentation, milk proteins were fractionated by size-exclusion HPLC and were tested for antimutagenicity. The fraction showing the greatest activity was further analyzed by reverse-phase HPLC. Our results indicate that antimutagenic compounds are produced in milk during fermentation by L. helveticus, and the release of peptides is one possible contributing mechanism.

Internal fixation of displaced fractures of the sacrum

The results of internal fixation in 30 patients with displaced fractures of the sacrum were retrospectively reviewed. All fractures were displaced at least 1 cm. Neurologic injuries occurred in 40% (12 of 30) patients. In 17 patients who underwent open reduction, the preoperative displacement averaged 24 mm and the postoperative displacement averaged 4 mm. In the 13 patients in whom percutaneous fixation was done, the preoperative displacement averaged 15 mm and the postoperative displacement averaged 5 mm. All 30 fractures united. This review of 30 patients with displaced sacral fractures suggests that open reduction and iliosacral screw fixation leads to better reduction of the fracture site than does closed reduction and percutaneous fixation. Functional assessment indicated that the presence of a neurologic injury is the most important predictor of compromised outcome in patients with displaced sacral fractures.

The effect of milk fermentation by Lactobacillus helveticus on the release of peptides during in vitro digestion

This study evaluated the effect of protein hydrolysis by lactic acid bacteria during milk fermentation on the release of amino acids and peptides duing subsequently simulated peptic and pancreatic digestion. After digestion with trypsin, we compared the elution patterns of proteins and peptides obtained from unfermented milk and from milk fermented by Lactobacillus helveticus under pH control, using HPLC gel filtration and reverse-phase HPLC. The results indicate that milk fermentation affects the release of some amino acids during simulated gastrointestinal digestion and has a major impact on the modification of protein elution profiles obtained after digestion with trypsin. We conclude that proteolysis during fermentation may lead to the formation of novel peptides during gastrointestinal digestion.

Effect of feeding fermented, ammoniated, condensed whey permeate on intake, digestibility, rumen fermentation, and acid-base balance in sheep

Nine DLS rumen-cannulated wethers (69 kg avg BW) were used to study the effects of dietary supplementation with two types of fermented, ammoniated, condensed whey permeate on performance, rumen physiology and acid-base status in sheep fed high-grain diets. Sheep were fed three isonitrogenous (16% CP) diets according to a triple 3 × 3 Latin square design, with three 21-d periods each. One whey permeate contained ammonium lactate (AL) while the other contained ammonium propionate (AP). Urea was used as a source of NPN in the control diet (C). Diets, offered ad libitum, contained 78% barley and 18% dehydrated alfalfa meal. Dry matter and digestible energy intakes were about 15% higher for diets AL and AP than for diet C (P < 0.05). Dry matter digestibility was not affected by the treatments, whereas organic matter and energy digestibilities tended to be higher for diet AP than for diet AL (P < 0.07). Rumen fermentation was not affected by the treatments. Over a 4-h post-feeding period, sheep fed diet C had higher plasma concentrations of lactate (P < 0.06) and acetate (P < 0.04) but lower levels of plasma propionate (P < 0.06) than sheep fed the AL and AP diets. Plasma propionate 2 h after feeding was higher in sheep fed the AL diet versus the AP diet (P < 0.01). Sheep blood was mildly alkalotic despite the fact that sheep were fed a high-grain diet. The two types of fermented, ammoniated and condensed whey permeate were found to be good sources of NPN. Key words: Whey, rumen fermentation, acid-base balance, sheep

Influence of Ammonium Salts and Cane Molasses on Growth of Alcaligenes eutrophus and Production of Polyhydroxybutyrate

The production of polyhydroxybutyrate (PHB) by Alcaligenes eutrophus DSM 545 was studied in a synthetic medium with 3% glucose at pH 7.0 supplemented with several ammonium substrates and cane molasses. Growth was measured by dry cell weight, and the PHB content was measured by gas chromatography. The effects of ammonium sources such as sulfate, nitrate, phosphate, and chloride salts and those of different ammonium sulfate concentrations were evaluated. The best growth and PHB production were obtained with ammonium sulfate; however, NH(inf4)(sup+) concentrations between 0.5 and 1.5 g/liter showed no significant difference. Ammonium sulfate was therefore used as the sole source of NH(inf4)(sup+) for experiments with cane molasses as the growth activator. Optimal growth and PHB production were obtained with 0.3% molasses. However, the yields of biomass (39 to 48%) and PHB (17 to 26%) varied significantly among the different ammonium substrates and cane molasses concentrations.

Ethical issues involved in establishing a registry for familial Alzheimer's disease

In January 1992, the IMAGE Project extended the establishment of its registry of familial Alzheimer cases to all areas of the province of Quebec, for collection of epidemiological and clinical data, as well as biological samples. The aim is to study genetic transmission patterns of Alzheimer's disease (AD) and to provide a sampling framework for further etiologic and risk factor studies. The IMAGE registry already includes data of a population-based study in the Saguenay-Lac-St-Jean area; the project to collect data on familial AD (FAD) cases across the province of Quebec is known as the ALGENE Initiative. The registry is thus a collection of "AD families" for both familial and sporadic cases. The establishment of the registry involves several steps in the field work: recruitment and selection of families; collection of information on family medical history; selection of informative families and genetic testing for AD/FAD by linkage analysis. As AD is not homogeneous in its etiology and since we do not know if, in the event that genetics is involved in AD whether or not penetrance of the gene(s) is high, we must be aware of the "genetic horizons" of AD in collecting and conserving data on families of cases, and in the genetic testing for AD/FAD by linkage analysis. Families who choose genetic testing must be aware of the implications of our undertaking, assured of the confidentiality of the test and, at the same time, they must understand its limitations. The experimental nature of our research project raises ethical dilemmas. This article examines these initial considerations of the field work involved in developing a registry pertaining to genetic testing for AD/FAD by linkage analysis and offers some preliminary observations on the experience of the first year of this project.

[Effect of patient education on neuroleptic treatment of young psychotic patients]

This study verifies the effect of the neuroleptic treatment teaching module, the French translation of the Medication Management Module produced by the social skills training programs. Twenty patients from an outpatient clinic (with schizophreniform or schizoaffective schizophrenia) were assigned at random to a test group (n = 10) or a control group (n = 10). The pre-test evaluation found that the two groups were the same with regard to 13 significant parameters. The experimenters used French translations of well-known instruments, and the double-blind method was applied to their respective observations throughout the study. Results were obtained by applying the neuroleptic treatment teaching module three hours per week for two to three months. The post-test evaluation revealed that patients who had been exposed to the education module had an improved understanding of schizophrenia and the medication required to treat it than patients who had not been exposed. The dose of medication prescribed between pre- and post-test evaluations were able to more effectively stabilize patients who had received education than patients who had not. Nevertheless, the education module continues to have no significant effect on the symptomatology (according to the Brief Psychiatric Rating Scale) and final SAS-II social scores of schizophrenics.

Biological inactivation of adhering Listeria monocytogenes by listeriaphages and a quaternary ammonium compound

The use of listeriaphages as a means of disinfecting contaminated stainless-steel and polypropylene surfaces was investigated. Surfaces artificially contaminated with L. monocytogenes 10401 and 8427 were sanitized with suspensions of listeriaphages (H387, H387-A, and 2671), all belonging to the Siphoviridae family. Phage suspensions at concentrations of up to 3.5 x 10(8) PFU/ml were at least as efficient as a 20 ppm solution of a quaternary ammonium compound (QUATAL) in reducing L. monocytogenes populations. A synergistic activity was observed when two or more phages were used in combination and when phages were suspended in QUATAL. The biological activity of the three phages was not affected by QUATAL concentrations of 50 ppm and a contact time of 4 h.

Two-year follow up of bipolar hemiarthroplasty

Forty-seven bipolar hemiarthroplasties were performed from January 1985 to December 1986. Twenty-three patients (24 hips) returned for a history, physical, and repeat radiographs. Ten primary press-fit and two cemented primary bipolar hemiarthroplasties were performed. Four patients underwent cemented and eight received press-fit revision bipolar hemiarthroplasties. Fourteen patients had simultaneous cancellous, reamed femoral head autograft, or allograft acetabular bone augmentation. Omitting one patient who had replacement for Lévi's pleonosteosis, the average acetabular migration among the remaining 23 patients was 4 mm of superior and 1.5 mm of medial progression. The mean modified d'Aubigne hip score was 33 for primary press-fit arthroplasty, 30 for primary cemented arthroplasty, 22 for press-fit revisions, and 32 for cemented bipolar revision arthroplasty. Morcellized bone graft tended to variably resorb with time. Among the press-fit stems, all but two patients complained of at least occasional thigh pain. All but one patient with primary press-fit hemiarthroplasty walked with a limp. We conclude that, although good early results can be obtained, significant number of patients will have groin and thigh pain. We have found no evidence either radiologically or clinically that nonstructural bone grafting with reamed femoral head will reliably incorporate or prevent further acetabular migration.

Effect of Feeding Lactic Acid Bacteria and Fermented Milk on Specific and Nonspecific Immune Reponses of Mice Infected With Klebsiella pneumoniae AD-1

The diets of six groups of weaned mice were supplemented with ultra high temperature (UHT) milk containing a washed suspension of lactic acid bacteria (mixture of 8 strains) or with UHT milk fermented by the same strains and heat-treated or not. Control groups received physiological saline or UHT milk only. The mice were infected intranasally by Klebsiella pneumoniae AD-1 on the 13th d of feeding. The effect on the immune system (specific and nonspecific) before and after infection was evaluated by measuring the phagocytosis of alveolar macrophages (using zymosan particles) and by measuring of total immunoglobulin G and A levels in serum and in pulmonary fluid (using the enzyme-linked immunosorbent assay method). Postinfection survival was 0.7 d longer for mice receiving fermented milk than for the saline control group. The percent phagocytosis did not vary significantly, while serum immunoglobulin G levels differed between mice fed fermented milk and those fed bacterial suspensions in unfermented milk. Fermentation appears to be essential for the beneficial effects on the immune system and survival time; this effect no longer occurs after pasteurization of fermented milk.

Burden of care of families not living with young schizophrenic relatives

A program that provides comprehensive support services to young schizophrenic adults and their families in Montreal was evaluated after one year to assess the needs of families, especially single-parent families, after the young adult patient left home. Results of the evaluation, which employed a case-control design, showed that compared with families receiving the usual services, families in the program reported feeling less burdened by the patients' personal problems. They also received more services and had more contact with professionals. Patients living away from home spent more than 18 hours a week in face-to-face contact with their families. Single parents of mentally ill young adults spent much less time with their offspring and expressed more need for services and a greater burden of care than married parents.

Characterization of physicochemical forces involved in adhesion of Listeria monocytogenes to surfaces

This study investigated the physicochemical forces involving the adhesion of Listeria monocytogenes to surfaces. A total of 22 strains of L. monocytogenes were compared for relative surface hydrophobicity with the salt aggregation test. Cell surface charges and hydrophobicity of L. monocytogenes Scott A were also determined by electrophoretic mobility, hydrophobic-interaction chromatography, and contact angle measurements. Electrokinetic measurements indicated that the strain Scott A has a negative electrophoretic mobility. Physicochemical characterization of L. monocytogenes by various methods indicates that this microorganism is hydrophilic. All L. monocytogenes strains tested with the salt aggregation test method aggregated a at very high ammonium sulfate molarities. The hydrophobicity-interaction chromatography results show that L. monocytogenes Scott A cells do not adhere to octyl-Sepharose unless the pH is low. Results from contact angle measurements showed that the surface free energy of strain Scott A was 65.9 mJ.m-2, classifying this microorganism as a hydrophilic bacterium. In addition, the interfacial free energy of adhesion of L. monocytogenes Scott A estimated for polypropylene and rubber was lower than that for glass and stainless steel. However, these theoretical implications could not be correlated with the attachment capabilities of L. monocytogenes.

Bioluminescence assay for estimating the hydrophobic properties of bacteria as revealed by hydrophobic interaction chromatography

The luciferin-luciferase bioluminescence method was used to estimate the number of bacteria retained in neutral and amphiphilic gels and those in the eluate to determine the hydrophobic surface properties of bacteria by using hydrophobic interaction chromatography. Good correlations were found between viable counts and ATP content for Escherichia coli, Pseudomonas fragi, and Listeria monocytogenes. ATP determination was more rapid than viable counts for characterizing the relative hydrophobicity of L. monocytogenes. Quantitative estimations of adsorption of L. monocytogenes on octyl-Sepharose indicate that this microorganism is hydrophilic.

Rapid and sensitive sandwich enzyme-linked immunosorbent assay for detection of staphylococcal enterotoxin B in cheese

A rapid and sensitive screening sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the detection of staphylococcal enterotoxin B (SEB) in cheese by using a highly avid anti-SEB antibody (Ab) as the capture Ab (CAb) and as the biotinylated Ab conjugate. The glutaraldehyde fixation method for the immobilization of CAb on polystyrene dipsticks was superior to the adsorption fixation and the adsorption-glutaraldehyde fixation methods. The glutaraldehyde fixation method resulted in a higher surface-saturating CAb concentration as evaluated by the peroxidase saturation technique and by the ability of the CAb-coated dipstick to discriminate between positive and negative controls (index of discrimination). Of nine blocking agents used alone or in pairs, lysine-human serum albumin, bovine serum albumin, human serum albumin, and gelatin effectively saturated available sites on the CAb-coated dipsticks without causing interference with the antigen-Ab reactions. The addition of 1% polyethylene glycol to the diluent of the biotinylated anti-SEB Ab conjugate improved the detection of SEB. A concentration of 4% polyethylene glycol allowed a 5-min reaction time for the streptavidin-biotin-horseradish peroxidase conjugate. Cheddar cheese homogenate reduced the sensitivity of the SEB assay; however, the sensitivity was restored when 1.6% (wt/vol) of either a nonionic detergent (Mega-9) or two zwitterionic detergents (Zwittergent 3-10 and 3-12 detergent) was added to the diluent. By using the rapid sandwich ELISA, a minimum of 0.5 to 1.0 ng of SEB per ml was detected within 45 min. The whole procedure for the analysis of the cheddar cheese samples was completed within 1 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipid Content and Cryotolerance of Bakers' Yeast in Frozen Doughs

The relationship between lipid content and tolerance to freezing at −50°C was studied in Saccharomyces cerevisiae grown under batch or fed-batch mode and various aeration and temperature conditions. A higher free-sterol-to-phospholipid ratio as well as higher free sterol and phospholipid contents correlated with the superior cryoresistance in dough or in water of the fed-batch-grown compared with the batch-grown cells. For both growth modes, the presence of excess dissolved oxygen in the culture medium greatly improved yeast cryoresistance and trehalose content (P. Gélinas, G. Fiset, A. LeDuy, and J. Goulet, Appl. Environ. Microbiol. 26:2453-2459, 1989) without significantly changing the lipid profile. Under the batch or fed-batch modes, no correlation was found between the cryotolerance of bakers' yeast and the total cellular lipid content, the total sterol content, the phospholipid unsaturation index, the phosphate or crude protein content, or the yeast cell morphology (volume and roundness).