Technology implementation in care practices for community-dwelling older adults with mild cognitive decline: Perspectives of professional caregivers in Quebec and Brussels.

Objective: As worldwide population aging is accelerating, innovative technologies are being developed to support independent living among community-dwelling older adults with mild cognitive decline. However, the successful implementation of these interventions is often challenging. Until now, literature on implementation issues related to the specific context of older adults with mild cognitive decline is lacking and the few studies available do not focus specifically on the perspective of professional caregivers. Yet the perspective of these caregivers is important as they can be considered a key facilitator for technology implementation among this population. Therefore, this study was the first to examine technology implementation among community-dwelling older adults with mild cognitive decline from the broader perspective of professional caregivers. Methods: In this qualitative study, two focus groups consisting of a heterogeneous pool of professional caregivers were conducted: one in Quebec (Canada, n = 6) and one in Brussels (Belgium, n = 8). Braun and Clarke' method for thematic analysis, guided by a qualitative descriptive approach was applied to inductively identify themes from the data. Results: We identified factors influencing technology implementation in older adults with mild cognitive decline on three levels: an individual level (e.g., characteristics of older adults with mild cognitive decline and professional caregivers' attitude), an organizational level (e.g., lack of training among professional caregivers) and a level referring to the broader context (e.g., ethical considerations). Conclusions: This study contributes to the research gap in knowledge on the needs of professional caregivers to facilitate technology implementation among the population of older adults with cognitive decline. Future directions for research, practice, and policy are given, more specifically to improve knowledge among caregivers and on the development of decision support to retrieve safe and effective technologies that suit patient-centered care.

Nutrition and Physical Activity Clinical Practice Guidelines for Older Adults Living with Frailty.

BACKGROUND: We developed clinical practice guidelines to provide health care providers with evidence-based recommendations for decisions related to the effective management of frailty and pre-frailty using nutrition and physical activity interventions. METHODS: We based the recommendations on two systematic reviews with meta-analyses. Nutrition, physical activity, and combined nutrition and physical activity interventions for adults ≥65y were considered if study populations were identified as frail using a frailty tool or assessment. Risk of bias and certainty of evidence were evaluated. We included physical outcomes, mobility, frailty, cognitive function, activities of daily living, falls, quality of life, diet quality, energy/fatigue levels, health services use, and caregiver outcomes. RESULTS: Overall, mobility improvements were moderate with nutritional strategies that optimize dietary intake, various types of physical activity interventions, and interventions that combine nutrition and physical activity. Physical outcomes, such as body mass and muscle strength, improved moderately with nutritional strategies and interventions that combined nutrition with physical activity. Frailty status improved with multi-component physical activity interventions. Strong recommendations include optimizing dietary intake, performing physical activity, and adopting interventions that combine nutrition and physical activity. We strongly recommend various types of physical activity including muscle strengthening activities, mobilization or rehabilitation exercises, and multi-component physical activity interventions. INTERPRETATION: Tailored nutrition and physical activity interventions based on individual goals and health status are associated with improved clinical and physical outcomes. While the recommendations facilitate shared decision-making, we identified sparse application of validated frailty assessments and lack of standardized research outcomes as critical gaps in knowledge.

[Promoting home support for elderly people with neurocognitive disorders: Caregiver perception of the help-seeking process]. / Favoriser le maintien à domicile des personnes âgées atteintes de troubles neurocognitifs. Perception par les proches aidants de leur processus de recherche d'aide.

BACKGROUND: Caregivers play an essential role in maintaining home care for elderly people with dementia. However, it is difficult for caregivers to target their own needs as well as those of the person with neurocognitive disorders they support on a daily basis. Identifying the needed resources can also be difficult. In order to better assist caregivers in identifying resources needed to support their role, this study aims to understand the factors that influence their help-seeking process. METHODS: This qualitative and descriptive study focuses on the point of view of the main people affected by this problem: caregivers. Eleven caregivers of elderly people with dementia living at home were recruited by convenience sampling. Semi-structured interviews were conducted, and the data were analyzed according to Mast's typology. RESULTS: The factors influencing caregivers help-seeking process were categorized into five themes: 1) service-related (e.g. wait times); 2) personal (e.g. feeling intrusive); 3) experiential (e.g. positive use of a service); 4) relational (e.g. rejection of the elder), and 5) informational (e.g. directed to the right service). CONCLUSION: Caregivers face many challenges in their help-seeking process and want to be more proactively accompanied in a way adapted to their changing needs.

Social and societal implications of frailty, including impact on Canadian healthcare systems.

Frailty has many social and societal implications. Social circumstances are key both as contributors to frail older adults' health outcomes and as practical facilitators or barriers to intervention and supports. Frailty also has important societal implications for health systems and social care policy. In this discussion paper, we use a social ecology framework to consider the social and societal implications and impact of frailty at each level, from the individual, through relationships with family and friend caregivers, institutions, health systems, neighborhoods and communities, to society at large. We conclude by arguing that attention to these issues at a policy level is critical. We identify three target actions: 1) Social dimensions of frailty should be systematically considered when frailty is assessed. 2) Action is needed at the level of policies and programs to improve support for caregivers. 3) Policy review across all portfolios will benefit from a social frailty lens.

Developing a two-sided intervention to facilitate shared decision-making in haemophilia: decision boxes for clinicians and patient decision aids for patients.

BACKGROUND: People with haemophilia face many treatment decisions, which are largely informed by evidence from observational studies. Without evidence-based 'best' treatment options, patient preferences play a large role in decisions regarding therapy. The shared decision-making (SDM) process allows patients and health care providers to make decisions collaboratively based on available evidence, and patient preferences. Decision tools can help the SDM process. The objective of this project was to develop two-sided decision tools, decision boxes for physicians and patient decision aids for patients, to facilitate SDM for treatment decisions in haemophilia. METHODS: Development of the decision tools comprised three phases: topic selection, prototype development and usability testing with targeted end-users. Topics were selected using a Delphi survey. Tool prototypes were based on a previously validated framework and were informed by systematic literature reviews. Patients, through focus groups, and physicians, through interviews, reviewed the prototypes iteratively for comprehensibility and usability. RESULTS: The chosen topics were: (i) prophylactic treatment: when to start and dosing, (ii) choosing factor source and (iii) immunotolerance induction: when to start and dosing. Intended end users (both health care providers and haemophilia patients and caregivers) were engaged in the development process. Overall perception of the decision tools was positive, and the purpose of using the tools was well received. CONCLUSIONS: This study demonstrates the feasibility of developing decision tools for haemophilia treatment decisions. It also provides anecdotal evidence of positive perceptions of such tools. Future directions include assessment of the tools' practical value and impact on clinical practice.

Effect of dietary organic and inorganic selenium on antioxidant status, embryo development, and reproductive performance in hyperovulatory first-parity gilts.

This project aimed to determine the effect of Se as inorganic Na-selenite (MSe) or organic Se-yeast (OSe) on antioxidant status, hormonal profile, reproductive performance, and embryo development in first-parity gilts. Forty-nine gilts were allocated to 1 of the 3 dietary treatments starting at first pubertal estrus and lasting up to 30 d after AI: control [CONT: basal diet (Se = 0.2 mg/kg) without added Se; n = 16], MSe (CONT + 0.3 mg/kg of MSe; n = 16), and OSe (CONT + 0.3 mg/kg of OSe; n = 17). Blood was collected from all gilts on the day after each onset of estrus and on d 30 after AI. Blood was also collected daily from d -4 to d +4 of the third onset of estrus (d 0) in 8 CONT, 9 MSe, and 8 OSe cannulated gilts. Gilts had received, after d 14 and 15 of their third estrus, a hormonal challenge to induce super-ovulation. At slaughter, embryos and corpora lutea (CL) were weighed and measured. Blood Se was less (P < 0.01) in CONT than in Se gilts and greater in OSe than in MSe (P < 0.01) from the first estrus until d 30 of gestation. At the same time, blood Se-dependent glutathione peroxidase (GSH-Px) decreased for CONT gilts, whereas it increased for both Se groups. The increase was greater in MSe than in OSe gilts (treatment × time, P = 0.02). Plasma 3,3',5-triiodothyronine and thyroxine concentrations for MSe tended to be less than for OSe gilts (P < 0.06). In cannulated gilts, plasma FSH tended to change among treatments (treatment × time, P = 0.06), and plasma estradiol-17ß (E(2)) was less (P = 0.01) for MSe than for OSe. There was no treatment effect on mean litter size or embryonic antioxidant status. The Se content of individual embryos was greater for Se-treated than for CONT gilts (P = 0.03), and Se content of individual embryos and total litter was greater for OSe than for MSe gilts (P < 0.01). The length, weight, and protein content of embryos were greater in OSe than in MSe gilts (P < 0.05). There was no treatment effect on weight, length, Se content, and ferric reducing antioxidant power of CL, but GSH-Px in CL was greater for Se than for CONT gilts (P = 0.02). In summary, the Se status response of gilts to dietary Se was affected by both the quantity and the source of Se dietary supplements. Moreover, the uterine transfer of Se to embryos was improved with OSe as compared with MSe, and this was concomitant with an enhanced development of embryos.

Treatment of hepatitis C virus infection in patients on maintenance hemodialysis: a single United Arab Emirates center experience.

BACKGROUND: Hepatitis C is prevalent among hemodialysis patients. In patients with normal kidney function, treatment with pegylated interferon and ribavirin can lead to eradication of HCV (hepatitis C virus). But the treatment is more problematic in patients with impaired kidney function, in part due to the altered pharmacokinetics of these medications. Despite recent guidelines, the optimal strategy in this group of patients is not well defined. METHOD: In a retrospective study, we reviewed all patients with chronic hepatitis C on hemodialysis treated at Sheikh Khalifa Medical City, in the United Arab Emirates between 2003 and 2009. The aim of our study was to determine the rate of sustained viral response (SVR) and to establish the safety and rate of dropouts in the different treatment regimens used (patients treated with peginterferon only and patients treated with peginterferon and low dose ribavirin). RESULTS: 22 patients were treated during this period. 5 patients received monotherapy with a reduced dose of peginterferon alfa 2b s.c. once weekly while 17 patients were treated with a combination of reduced dose of peginterferon alfa 2a or 2b s.c. once weekly and a low dose ribavirin (200mg/day). A SVR was achieved in 73% (16/22 patients) of the total patient population and in 76% (13/17 patients) in the sub-group of patients treated with a combination therapy. The tolerability was high. No patients had to discontinue their treatment. The use of ESA (erythropoietin stimulating agents) and G-CSF was common in the combination therapy (94% and 53% respectively). CONCLUSION: In our study of patients on hemodialysis with chronic hepatitis C, the use of peginterferon or a combination of peginterferon with a low daily dose of ribavirin achieved a high rate of SVR and the rate of dropout was low after pursuing an aggressive management of side effects.

Dietary supplementation with different forms of flax in late gestation and lactation: Effects on sow and litter performances, endocrinology, and immune response.

The impact of feeding flax as seed, meal, or oil to late-pregnant and lactating sows on hormone concentrations, immune responses, and sow and litter performances was studied. Sixty sows were fed 1 of 4 diets from 68 d of gestation until 21 d of lactation. Diets were standard (CTL; n = 15); 10% flaxseed supplementation (FS; n = 16); 6.5% flaxseed meal supplementation (FSM; n = 14); and 3.5% flaxseed oil supplementation (FSO, n = 15). On d 88 and 101 of gestation, sows were immunized against ovalbumin (OVA). Jugular blood samples were obtained on d 62, 88, and 110 of gestation and on d 2 and 21 of lactation to measure concentrations of estradiol, prolactin, and progesterone as well as antibody (Ab) against OVA (anti-OVA), lymphocyte proliferation, and lymphocyte production of interferon-gamma (IFN-gamma). Milk samples were obtained on d 3 and 20 of lactation. One piglet per litter was slaughtered on d 1 for compositional analyses, and a jugular blood sample was obtained for anti-OVA analyses. Remaining piglets were weighed on d 2, 7, 14, 21 (weaning), 28, and 56. Circulating hormone concentrations in sows were not affected by treatment overall (P > 0.1). On d 20 of lactation, milk from FS, FSM, and FSO sows had more protein than that from CTL sows (P < 0.01). The FSM piglets weighed more on d 56 (P < 0.05) than FS and FSO piglets. Carcasses of 1-d-old FSM piglets also had greater glycogen (P < 0.001) and DM (P = 0.05) contents than FS and FSO piglets, but organ weights and circulating concentrations of glucose and IGF-I did not differ (P > 0.1). In CTL sows, IFN-gamma production decreased between d 101 of gestation and d 2 of lactation, whereas, in FS sows, IFN-gamma production increased (P < 0.01). Anti-OVA for the whole experimental period was greater in FS than in FSO sows (P < 0.05). Concentrations of anti-OVA in milk on d 3 of lactation and lymphocyte proliferative responses were not affected by treatments (P > 0.1). Serum concentrations of anti-OVA in 2-d-old piglets that gained BW during the first 24 h after birth were greater (P < 0.01) in FS, FSM, and FSO litters than in CTL litters and percent mortality on d 2 and 21 postpartum was less (P < 0.05) for FS, FSM, and FSO litters compared with CTL. Therefore, feeding flax to sows may have beneficial effects on immune resistance of piglets and feeding FSM improved postweaning growth of piglets.

Effects of concentrations of cyanocobalamin in the gestation diet on some criteria of vitamin B12 metabolism in first-parity sows.

In swine nutrition, little is known about the role of vitamin B(12) in the reproductive processes. The current study was undertaken to obtain information on the dose-response pattern of different metabolic criteria related to the homeostasis of vitamin B(12) and homocysteine in gestating sows receiving various concentrations of dietary vitamin B(12) (cyanocobalamin). Homocysteine is a detrimental intermediate metabolite of the vitamin B(12)-dependent remethylation pathway of Met. Forty nulliparous (Large White x Landrace) sows were randomly assigned during gestation to dietary treatments containing 5 concentrations of cyanocobalamin (0, 20, 100, 200, or 400 microg/kg). During lactation, a diet containing 25 microg of cyanocobalamin/kg (as-fed) was given to all sows. During gestation, plasma vitamin B(12) increased as concentrations of dietary cyanocobalamin increased (linear and quadratic, P < 0.01) and the effect persisted during lactation (21 d postpartum) both in plasma (linear and quadratic, P < 0.05) and the liver (linear and quadratic, P < 0.04). Plasma homocysteine decreased with concentrations of cyanocobalamin provided to sows during gestation (linear, quadratic, and cubic, P < 0.01). At parturition, vitamin B(12) in colostrum increased as concentrations of cyanocobalamin increased (linear and quadratic, P < 0.01), but the treatment effect persisted (linear, P = 0.01) only up to 1 d postfarrowing. However, in piglets there was no treatment effect (P = 0.59) on plasma vitamin B(12) before colostrum intake, but a linear effect of concentrations of cyanocobalamin (P = 0.04) was observed 1 d later. Plasma homocysteine in piglets during lactation decreased with increasing concentrations of cyanocobalamin given to sows in gestation (linear and quadratic, P < 0.01). Based on a broken-line regression model, the concentrations of dietary cyanocobalamin that maximized plasma vitamin B(12) and minimized plasma homocysteine of sows during gestation were estimated to be 164 and 93 microg/kg, respectively. The maximal residual responses in sows and piglets during lactation were observed with treatments of 100 or 200 microg of cyanocobalamin/kg. The dietary cyanocobalamin concentration necessary to optimize the response of these metabolic criteria remains to be refined within lower and narrower ranges of cyanocobalamin concentrations (i.e., <200 mg/kg). Moreover, the biological significance of such concentrations of cyanocobalamin needs to be validated with performance criteria by using greater numbers of animals during several parities.

Effect of feed texture, meal frequency and pre-slaughter fasting on carcass and meat quality, and urinary cortisol in pigs.

Carcass and meat quality traits, and urinary cortisol variation was studied in 96 barrows assigned to the following treatments: feed texture (FT; mash vs. pellets), meal frequency (MF; 2 vs. 5 meals per day) and fasting time (F; 4, 14 and 24h) according to a 2×2×3 factorial design. Pigs fed mash, receiving feed five times a day and fasted for 24h before slaughter had lower carcass dressing yield (P<0.001). A higher (P<0.05) bruise score was found on carcasses from pigs fasted for 14 and 24h and fed either pelleted or mashed feed five times per day. The pH(u) value in the Longissimus muscle increased (P<0.05) with increasing fasting time, whereas in the Adductor muscle it was higher (P<0.05) in pigs fed with pellets in two meals per day and fasted for 24h. Urinary cortisol tended to be higher in pigs fasted for 14h compared to those fasted for 4 (P=0.10) and 24h (P=0.06). The results of this study show a significant influence of pellet feeding on carcass yield in fasted pigs, while the effects of pre-slaughter fasting time on meat quality traits were limited.

Some aspects of the pyridoxine (vitamin B6) requirement in weanling piglets.

Four trials were carried out to determine the optimal level of dietary pyridoxine (vitamin B6) and its interaction with riboflavin (vitamin B2) in early-weaned piglets. In Trial 1, twelve piglets were tube-fed graded supplements of B6, 0, 10, 50 or 100 mg/kg. The level of 50 mg/kg maximized B6 in red blood cells (P<0.05). In Trial 2, thirty-six piglets were tube-fed with four combinations of B6 (0 v. 50 mg/kg) and B2 (0 v. 25 mg/kg). The B6 supplement increased (P<0.01) B6 in red blood cells. C-peptide and insulin responses to intravenous glucose tended (P<0.08) to or decreased (P<0.03) with B2 while no effect was observed on glucose. After gastro-enteral glucose, dietary B2 depressed C-peptide and insulin responses in B6-unsupplemented piglets and increased them in B6-supplemented piglets (P<0.03). The glucose response tended to be higher in B6-supplemented piglets (P<0.06). Trials 3 and 4 were carried out in commercial conditions using either B6 and/or B2 supplements given during 2 weeks after weaning (Trial 3) or a B6 supplement alone (50 mg/kg) given between 2 (weaning) and 10 weeks of age. Despite a marked and persistent increase (P<0.01) of B6 in red blood cells in B6-supplemented piglets, the effect on growth performance was either none (P>0.39; Trial 3) or marginally lower (<-2 %; P<0.03; Trial 4). In conclusion, it appears that a dietary supplement of 50 mg/kg B6 saturated the red blood cell pool in B6 and influenced, along with B2, the glucose homeostasis through the entero-insular axis. Nevertheless, such metabolic effects are not reflected on growth performance.

Effect of dietary fat sources on systemic and intrauterine synthesis of prostaglandins during early pregnancy in gilts.

The present experiment was conducted to determine the influence of dietary fatty acids C18:2n-6 and C18:3n-3 on the modulation of intrauterine synthesis of prostaglandin E2 (PGE2) and F2alpha (PGF2alpha) during early pregnancy in pigs. Prostaglandin E2 in uterine fluid has been previously reported to be associated with embryo survival and development. Thirty-two Yorkshire-Landrace nulliparous gilts were randomly allocated to four diets containing 5% supplemental fat. The four dietary treatments were: HT, hydrogenated tallow (26.5% C16:0 and 54.8% C18:0); SO, sunflower oil (61.3% C18:2n-6); LO, linseed oil (50.4% C18:3n-3); and SO(CLA), a mixture of sunflower oil and conjugated linoleic acids to provide 20% CLA. Treatments started 2 d after the first pubertal estrus (d -21) and lasted for 36 d (slaughter), which was 15 d after the second estrus (d 0; insemination). Fatty acids and PGE2 were measured in the peripheral blood plasma on d -19, d -7, d 0, and d 14. Fatty acids in endometrial tissues and PGE2 and PGF2alpha in the uterine fluid collected on d 15 were also measured. Concentrations of fatty acids in the plasma reflected the content of fatty acids in the diet as early as d -7. From d -7, PGE2 concentrations in the plasma were higher in gilts fed SO compared with HT (P < 0.05). Plasma PGE2 concentrations were lower (P < 0.01) on d 14 in gilts fed LO compared with HT. Total PGF2alpha contents in the uterine fluid of gilts fed LO were more than 70% lower (P < 0.05) than for the HT group. A similar trend was observed for total PGE2 content and for the ratio PGF2alpha:PGE2, but the effect (LO vs HT) was less marked (P < 0.07 and P < 0.10, respectively). There was no effect of SO or SO(CLA) on total PGE2 contents in the uterine fluid. Dietary enrichment in C18:2n-6 and/or C18:3n-3 for early pregnant gilts can influence fatty acids in plasma and endometrial tissue and can modulate circulatory and intrauterine prostaglandins.

Effect of folic acid and glycine supplementation on embryo development and folate metabolism during early pregnancy in pigs.

The present work aimed to determine if different levels of prolificacy either by parity or by genetic origin are linked to folate metabolism. Nulliparous Yorkshire-Landrace (YL) and multiparous YL, and multiparous Meishan-Landrace (ML) sows were randomly assigned to two treatments: 0 ppm or 15 ppm folic acid+0.6% glycine. Supplements were given from the estrus before mating until slaughter on d 25 of gestation. At slaughter, embryo and endometrial tissues were collected to determine concentrations of DNA, protein, and homocysteine. Allantoic fluid samples were also collected to determine concentrations of folates, vitamin B12 and amino acids. Blood samples were taken at first estrus, at mating, and on d 8, 16, and 25 of gestation to determine serum concentrations of folates, vitamin B12, and relative total folate binding capacity (TFBC). Over the entire experiment, multiparous YL sows had higher average serum concentrations of folates than nulliparous YL sows (P < 0.05) but had similar serum concentrations of relative TFBC. Concentrations of folates and relative TFBC averaged higher in ML measured over the entire experiment than in multiparous YL sows (P < 0.05). Concentrations of serum vitamin B12 were higher in multiparous YL than in ML sows or YL nulliparous sows (P < 0.05) over the entire experiment. In allantoic fluid, folates, vitamin B12, and essential amino acids contents were significantly lower in ML than in YL multiparous sows (P < 0.05). The folic acid+glycine supplement increased concentrations of serum folates, but the increase was more marked in nulliparous YL sows (nulliparous x folic acid+glycine, P < 0.05). The folic acid+glycine supplement had no effect on litter size and embryo survival, but it tended to increase embryo DNA in multiparous YL sows (P = 0.06) but not in ML and nulliparous YL sows. Homocysteine was decreased by folic acid+glycine supplement in embryos from all sows, but in endometrium, the folic acid+glycine effect was dependent on parity (nulliparous x folic acid+glycine, P < 0.05). The effects of folic acid+glycine on litter size and embryo development and survival and some aspects of folate metabolism suggest that the basal dietary content of folic acid+glycine was adequate for ML and nulliparous YL sows but not to optimize embryo development in YL multiparous sows.

Cadmium accumulation and metallothionein synthesis in freshwater bivalves (Pyganodon grandis): relative influence of the metal exposure gradient versus limnological variability.

The relative influence of limnological confounding factors on cadmium (Cd) bioaccumulation and metallothionein (MT) synthesis was quantified in natural populations of freshwater bivalves (Pyganodon grandis) living in lakes along a Cd concentration gradient. During the ice-free period, we measured 15 environmental variables in the water compartment and determined total concentrations of Cd and MT in the gills of bivalves at 37 littoral stations in 20 lakes distributed across the mining area of Rouyn-Noranda in northwestern Quebec. A multiple linear regression model including pH (+), dissolved Ca concentrations (-) and free Cd2+ concentrations at the sediment-water interface (+) explained 74% of the variability in Cd concentrations in the bivalve gills. Dissolved Ca (-) and free Cd2+ (+) together explained 62% of the variation in MT concentrations in the bivalve gills. Partial linear regression analyses indicated that the limnological factors' pure and shared effects together accounted for 48 and 45% of the total variation in Cd and MT concentrations in the gills, respectively. A lake selection procedure that could be applied in monitoring programs is proposed to minimise the relative influence of these confounding variables.

Erythrocyte glutathione reductase activity and riboflavin nutritional status in early-weaned piglets.

The reliability of erythrocyte glutathione reductase activity (EGRAC) as an indicator of riboflavin (vitamin B2) status was determined in 36 piglets weaned at two weeks of age. Total B2 metabolites determined by high-performance liquid chromatography (HPLC) in plasma, red blood cells, and liver were used as reference values. There was no correlation between EGRAC values and total B2 metabolites either in circulation (r < 0.15, p > 0.08) or in liver (r < 0.01, p > 0.95). EGRAC does not appear to be a reliable biochemical indicator of vitamin B2 status in the pig.

Evaluation of gastric emptying function in clinical practice.

In this retrospective analysis, we compared different methods to evaluate gastric emptying function, aiming to improve the sensitivity and the clinical availability of our diagnostic testing. In the first study, we compared, in 72 patients clinically suspected of gastroparesis, the emptying of a meal containing two solid nutrients with different disintegration rates: 111In-labeled scrambled eggs and 99Tc-labeled liver cubes. Gastric emptying of 111In-labeled egg was delayed in 12 of our patients and the evacuation of the 99Tc-labeled liver was prolonged in 19 patients. The choice of the nutrient was not important for the identification of diabetic gastroparesis (43% vs 57%; NS), but it was determinant in the case of patients suspected of idiopathic gastroparesis (12% were positive with the egg and 25% with the liver; P < 0.05). In the second study, we compared two different diagnostic methods in 46 patients: a simple radiological detection of the gastric emptying of radiopaque pellets, and the scintigraphic emptying of a solid meal containing 99Tc-labeled liver cubes. Both tests correlated perfectly in 78% of our patients. In 15% of the population (six of these seven patients were diabetics suspected of gastroparesis) the scintigraphic method was normal, while the evacuation of radiopaque pellets was delayed. For clinical purposes, we therefore propose: (1) the scintigraphic method should use liver rather than egg as a radiolabeled tracer in order to improve the sensitivity of the test for detection of gastroparesis; and (2) the radiological detection of radiopaque markers is a reliable and convenient method for the detection of gastroparesis in clinical practice. It is possibly more sensitive than scintigraphy.

Effect of thyroid hormones on G proteins in synaptosomes of chick embryo.

We have described a thyroid hormone receptor in synaptosomes of the chick embryo brain. To understand how the hormones exert their actions at this level, we performed a series of studies to demonstrate that this receptor could be linked to G proteins. Guanosine 5'-[gamma-thio]triphosphate (GTP gamma S)(100 muM) lowered the binding capacity of the receptor high affinity site from 8.9 +/- 1.3 to 3.4 +/- 1.3 ng T3/mg protein, a finding consistent with the coupling of receptor to G proteins. Furthermore, ADP ribosylation with pertussis toxin showed that thyroid hormones induced a dose-dependent increase in the inactive alpha 0-subunit of the G0 protein. This effect was detected at 10 pM, with a maximal increase (mean +/- SEM, 50 +/- 3.6%) at 100 nM, and T4 was as effective as T3. Both hormones also decreased the intrinsic guanine triphosphatase activity of G proteins by lowering the binding of GTP to the alpha-subunit and their rate of hydrolysis. This inhibition was greater with T4 (25 +/- 5%) than with T3 (14 +/- 2%), suggesting that the former could be the more active hormone at the synaptosomal level. The effect on guanine triphosphatase activity confirms that the synaptosomal thyroid hormone receptor is coupled to a G(zero) protein. These results demonstrate that thyroid hormones increase or favor the ADP ribosylation of G alpha(zero) by pertussis toxin. Thus, they enhance the alpha(zero)-GDP form of the G(zero) protein, namely its inactive conformation. By decreasing the activity of this protein, these hormones may modulate the formation of second messengers in synaptosomes and intervene in the regulation of neuronal proliferation and differentiation induced by several factors. Therefore, thyroid hormones may exert their action on brain maturation at least in part by modulating G alpha(zero) through their synaptosomal receptor.

3,5,3'-Triiodothyronine binding sites in synaptosomes from brain of chick embryo. Properties and ontogeny.

In this study we have demonstrated the presence of specific 3,5,3'-L-triiodothyronine (T3) binding sites in the synaptosomes of chick embryo cerebral cortex and described their ontogeny. Scatchard analyses of binding data obtained with synaptosomal preparations from 17-day-old embryos revealed two T3 binding sites. The first site (N1) had a high affinity and low capacity since its dissociation constant (Kd) was 68 +/- 1.3 nM T3 (mean +/- S.D.; n = 3-5) and its maximal binding capacity (Bmax) was 8.63 +/- 1.59 ng T3/mg of protein, whereas the second site (N2) had a higher Kd of 5.04 +/- 0.5 microM T3 and a larger Bmax of 405 +/- 49 ng T3/mg of protein. The relative affinity of the synaptosomal fraction for T3 and other analogs was the following: T3 greater than T4 (thyroxine) greater than D-T3 (3,5,3'-D-triiodothyronine) = TRIAC (triiodothyroacetic acid) greater than rT3 (reverse T3). Gel chromatography of the [125I]T3 labeled fraction revealed a partially saturable peak with an estimated MW of more than 100 kDa. The ontogenic pattern showed a progressive increase of Kd and Bmax of N1, occurring mainly between the 12 and 19 days of incubation, and a marked fall, particularly of the Bmax, after hatching. The second site did not show any important variation during the embryogenesis. These data indicate the existence of specific T3 binding sites in synaptosomes from cerebral cortex of chick embryo, whose properties and ontogeny are completely different from those of the nuclear receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

[The capitalist development of regions and labor force mobility in Quebec, from 1966 to 1976]. / Le developpement capitaliste des regions et la mobilite de la force de travail au Quebec, de 1966 a 1976.

"In this paper the author presents a study of the spatial mobility of the Quebec population between 1966 and 1976, in the light of regional capitalist development. Based on an empirical operationalization of the concepts of mobility and development, the author demonstrates that Quebec presents a very irregular distribution of its poles of development over its territory, and that the mobility of the work force is in the image of this distribution. A few regions within the Montreal metropolitan area have attained a relatively evolved state of capitalist development and consequently are able to attract within their limits a large majority of migrants moving inside of or toward Quebec. In contrast, it can be observed that the majority of the regions in Quebec may be qualified as 'underdeveloped', and that their net mobility figures are negative." (SUMMARY IN ENG AND SPA)