Single layer centrifugation of fresh dromedary camel semen improves sperm quality and in vitro fertilization capacity compared with simple sperm washing.

Single layer centrifugation (SLC) through a colloid is a tool for selecting viable mammalian spermatozoa but has not been used previously for fresh dromedary camel sperm. Semen from six camels (2 ejaculates/male) was diluted 1:5 (v:v) or 1:10 (v:v) in a Tris-citrate-fructose buffer for mechanical liquefaction by gentle pipetting. Following liquefaction, semen was processed either by SLC or by centrifugation without a colloid (control). Total and progressive motilities, CASA kinematics, vitality and acrosome integrity (eosin-nigrosin) and plasma membrane integrity (Hypo-osmotic swelling test; HOST), and fertilizing ability in a heterologous assay (zona-free goat oocytes) were evaluated. Both total (p = .003) and progressive motilities (p = .003) were higher in SLC-processed than in control semen samples, irrespective of dilution. Positive HOST values increased when using colloid in 1:5 (p = .001) and 1:10 dilution (p = .010). Colloid-selected sperm had higher penetration rates than controls (p < .001 and p = .02 for 1:5 and 1:10 dilutions, respectively). However, only the SLC sperm at 1:5 dilution showed higher percentages of pronuclear formation (p = .02) than controls. Dilution effect was only significant for total motility before in vitro fertilization, with higher values for the 1:5 dilution (p = .033). The recovery rates of motile sperm between dilutions were similar (26.1% vs 35.4%; p = .226). In conclusion, SLC is a promising tool for selecting functional dromedary camel sperm and warrants more research.

Effect of Camellia sinensis supplementation and increasing holding time on quality of cryopreserved boar semen.

Cryopreservation of boar semen is still considered suboptimal due to the low fertility when compared with fresh semen. This study was performed to evaluate the effects of green tea (Camellia sinensis) supplementation of the freezing extender at different concentration (0, 2.5%, 5%, 10%) and also to determine the influence of increasing holding time from 2 to 24 h at 15 °C. Seventeen ejaculates from nine boars were used to make pools of three of them and then cryopreserved. Sperm motility, viability, acrosome integrity, membrane functionality (HOST) and capacitation status were determined before freezing and at 0, 30, 60, 90 and 120 min after thawing. Lipid peroxidation was evaluated just after thawing. The main findings emerging from this study were the following: (i) no improvement in quality of thawed spermatozoa with addition of tea to the freezing extender, (ii) no improvement in quality of thawed spermatozoa with prolonged holding time, (iii) lower peroxidation rate in presence of tea 5% and (iv) a decrease in the number of uncapacited viable spermatozoa with any tea supplementation. We conclude that amplification of holding time in semen cryopreservation process does not vary results, facilitating freezing protocol. Tea supplementation reduces lipoxidation but did not improve quality parameters.

Sage (Salvia officinalis) and fennel (Foeniculum vulgare) improve cryopreserved boar epididymal semen quality study.

The aim of this study was to evaluate the effect of fennel and sage extracts and the influence of the egg yolk source (fresh or pasteurized) on the success of freezing boar epididymal spermatozoa. In experiment 1, epididymal sperm was recovered by flushing and cryopreserved in a lactose-egg yolk solution supplemented with various concentrations (10, 5 and 2.5 g/L) of sage or fennel. Sperm quality was evaluated (motility, viability, HOST and acrosome integrity) at 0 h and 2 h after thawing. Fennel 10 g/L and sage 5 g/L and control (no extracts) were selected for experiment 2 which also compared fresh or pasteurized egg yolk in the freezing extender and measured DNA integrity of the frozen sperm. Results showed that the interaction between fennel and sage antioxidants with fresh egg yolk significantly improved post thaw sperm quality and protected boar epididymal spermatozoa from cryopreservation damage as a result of oxidative stress.

Current status of freeze-drying technology to preserve domestic animals sperm.

In recent years, there has been an increased interest in new preservation techniques that facilitate sperm storage and distribution, with freeze-drying (FD) having been proposed as an alternative method for sperm preservation and maintenance of genetic resources in different animal species. FD is a method in which frozen material is dried by sublimation of ice, thereby involving a direct transition from a solid (ice) to a vapour (gas) phase. One of the main advantages of FD is that nitrogen and dry ice are no longer required for the storage and shipment of frozen sperm, which can be stored at room temperature or 4°C, thereby resulting in enormous reductions in storage and shipping costs. Unlike sperm cryopreserved after gradual freezing, the sperm membrane may be further damaged by both snap-freezing and drying stresses during the FD procedure. As mammalian spermatozoa lose their motility, viability and, at least partially, their DNA integrity when freeze-dried, they must be microinjected into an oocyte by intracytoplasmic sperm injection (ICSI). Although the efficiency of ICSI is limited when freeze-dried spermatozoa are used, embryos and live offspring can be produced. DNA fragmentation in freeze-dried spermatozoa is one of the main causes of failure of embryonic development and successful pregnancy. In this regard, it has been suggested that endonucleases are among the leading causes of DNA fragmentation in spermatozoa along with oxidative stress caused by the release of reactive oxygen species (ROS). Many factors influence the FD process, and it is not clear how FD affects specific components of sperm from different animal species. As such, a sound understanding of the FD process would result in increased production of embryos and/or live offspring. The aim of this review was to study the various stages and techniques used in the FD process and to further evaluate the results obtained.

Effect of different disaccharides on the integrity and fertilising ability of freeze-dried boar spermatozoa: a preliminary study.

Freeze-drying spermatozoa is a developing technique that facilitates semen storage and transport. However, freeze-dried sperm exhibits impaired DNA integrity, which is associated with reduced fertilizing ability. Boar spermatozoa were freeze-dried in three different freeze-drying EDTA buffers with trehalose (75mM) and lactose (75mM) (EDTA-TL), (2) with sucrose (75mM) and lactose (75mM) (EDTA-SL) or just lactose (150mM) (EDTA-LL) using two freeze-drying protocols. In experiment 1 a one-step protocol was used and in experiment 2 a two-steps protocol was used. Spermatozoa were stored in1.5 mL cryo-tubes and 1.5 mL glass ampules at both 16 degree C and 25 degree C for 1 month. Successfully freeze-dried spermatozoa were stained with acridine-orange to assess chromatin stability. Freeze-drying was most successful when the 2-step protocol was used (experiment 2). Chromatin stability was greater in samples stored in glass ampules compared to cryo tubes. Chromatin stability was also greater in samples freeze-dried in EDTA-LL compared to EDTA-SL or EDTA-TL buffers. Spermatozoa freeze-dried in EDTA-LL and stored for 14 and 28 days at either 16 degree C or 25 degree C were utilized for ICSI. Two pronuclear formation wasgreatest using spermatozoa stored at 25 degree C (69.23%) and for 28 days (50%). Although 16 degree C spermatozoa samples had better stable chromatin, 25 degree C spermatozoa samples offered better two pronuclear formation results. In conclusion, boar spermatozoa freeze-dried using media containing disaccharides exhibit high chromatin stability and are able to fertilise oocytes following ICSI. Disaccharides may therefore advance the development of freeze-drying techniques for spermatozoa enabling ease of sperm storage and transportation.

Comparing sex steroid levels during the annual cycles of rainbow trout (Oncorhynchus mykiss) diploid female (XX) and triploid female (XXX) genotypic sex.

In this study, the annual cycle of the gonadal steroids testosterone (T), 11-ketotestosterone (11-KT), 17ß-estradiol (E2) and 17α, 20ß-dihydroxy-4-pregnen-3-one (DHP) was determined using radioimmunoassay and then compared for two populations of rainbow trout, XX diploid females (n = 40) and XXX triploid females (n = 15). In females, E2 and DHP levels were found to be significantly related to body weight (r = 0.22513; p < 0.0001 and r = 0.15831; p > 0.001, respectively). In this group, E2 concentrations peaked in November (25.05 ng/ml), while maximum DHP levels, only measurable from October to April, were attained in February (64.14 ng/ml). No significant differences in hormone ranges related to egg output ability were observed. Finally, sex steroid concentrations were low in the triploid female XXX fish compared to the female XX population. Nevertheless, maximum T (33.85 ng/ml) and 11-KT (32.35 ng/ml) levels were recorded in January, for XXX. The levels for these two hormones are relatively high and are also significantly associated (r = 0.8430; p < 0.0001). Diploid females showed significantly higher levels of E2 than triploids over the 12-month study period. The female triploid fish produced the lowest steroid hormone levels, such that these would be the most suitable for human consumption.

Effect of pasteurized egg and Rosmarinus officinalis supplementation on quality of cryopreserved ram semen.

The aim was to assess the in vitro effect of pasteurized egg (PE) and rosemary (Rosmarinus officinalis) on frozen-thawed ram semen. Ejaculates from three mature rams of the Rasa Aragonesa breed were cryopreserved using a 2-step dilution method (Fraction 1: F1; Fraction 2: F2). In Experiment 1, semen was frozen in egg yolk (EY) or PE extenders. After thawing, similar results were obtained in terms of total and progressive motility, viability, hypo-osmotic swelling test (HOST) and acrosome integrity after 2 h incubation. In Experiment 2, addition of rosemary to F1, F2 or both fractions to EY extenders was evaluated. Rosemary in F1 decreased progressive motility (p = 0.013) after 2 h incubation. Finally, PE can be used as a substitute for EY to reduce hygienic risks in extenders and is easier to standardize. Supplementation of EY extender with rosemary in F1 reduced progressive motility. Rosemary supplementation in F2 does not affect semen quality.

Fennel (Foeniculum vulgare) provides antioxidant protection for boar semen cryopreservation.

Boar semen is extremely vulnerable to cold shock and it is also sensitive to peroxidation due to the high content of unsaturated fatty acids in the plasma membrane. Antioxidants exert a protective effect on the plasma membrane of frozen boar sperm. Fennel has been shown to contain antioxidant substances. Therefore, this study was performed to evaluate the effect of different concentrations of fennel added to the freezing extender on boar semen quality and lipid peroxidation after thawing. Semen collected from four boars was cryopreserved in lactose-egg-yolk extender or in the same extender with varying concentration of fennel essences: low (LF); medium (MF); high (HF). Analysis of data clearly indicated that higher concentrations of fennel produced significant improvement in total motility. Moreover, when fennel was included in the extender, a dose-dependent tendency to increase sperm viability was observed. In contrast, the addition of fennel had no effect on acrosome integrity or hypoosmotic swelling test (HOST) compared with the control. Malondialdehyde (MDA) formation decreased significantly in fennel groups, yielding similar results for MF and HF. Fennel seems a new antioxidant for use in sperm cryopreservation, but its particular effects on sperm physiology must be further studied, especially the causes of motility stimulation and its effect on lipoxidation.

Dimethylformamide is not better than glycerol for cryopreservation of boar semen.

To improve the boar sperm cryopreservation process, the influence of the sugar (lactose, trehalose) source and the cryoprotectant [glycerol, dimethylformamide (DMF)] on the success of freezing was investigated. Sperm samples were frozen in one of six extenders: lactose plus 3% glycerol (LG); lactose plus 1.5% glycerol and 1.5% DMF (LGD); lactose plus 3% DMF (LD); trehalose plus 3% glycerol (TG); trehalose plus 1.5% glycerol and 1.5% DMF (TGD); trehalose plus 3% DMF (TD). Effects on motility, viability, acrosome integrity and hypoosmotic test (HOST) were measured. The results showed that extender containing 3% glycerol retained the highest motility percentages. In regard to viability and acrosome integrity, all extenders yielded similar rates except for the decreasing values of TD. Endosmosis was diminished in TD and LD at 2 h (P = 0.0018), as compared with the others. The results of the study demonstrated that the use of DMF as a cryoprotectant adversely affected boar sperm quality after cryopreservation.

[Sevoflurane sedation protocol in children with cerebral palsy undergoing botulinum toxin-A injections]. / Protocolo de sedación con sevoflurano para la infiltración de toxina botulínica tipo A en parálisis cerebral infantil.

OBJECTIVE: This study aimed to describe our experience with a protocol based on sevoflurane sedation to control pain and agitation during botulinum toxin-A (BoNT-A) infiltration in children with cerebral palsy (CP), especially in terms of safety and efficacy. MATERIAL AND METHODS: We conducted a retrospective observational study of patients diagnosed with CP who underwent BoNT-A infiltration with sevoflurane sedation from November 2012 to December 2019. Demographic, clinical and functional characteristics, the effectiveness of sedation, adverse events (AE) and professional satisfaction were reviewed. RESULTS: A total of 387 sedations were successfully performed in 74 patients. Effective sedation was achieved in 100% of procedures, facilitating collaboration during infiltration and improving professional satisfaction. AE were reported in 6.02% of the procedures, the most frequent being nausea and vomiting (3.88%) and transient hypoxemia (2.07%). There were no severe AE. No association was found between the incidence of AE and the clinical and functional variables or risk before anaesthesia. CONCLUSION: Sevoflurane sedation shows promising results in terms of safety and effectiveness for the management of agitation and pain during BoNT-A infiltration in our daily clinical practice. In addition, it can facilitate infiltration, allowing examination under sedation and multilevel infiltration with good tolerance.

Comparing sugar type supplementation for cryopreservation of boar semen in egg yolk based extender.

Cryopreservation of boar semen is still considered suboptimal due to lower fertility when compared to fresh semen. The aim of this study was to evaluate the effects of the addition of different sugars (lactose, trehalose and glucose) on boar spermatozoa cryopreserved in an egg yolk based extender. Ejaculates were collected from a boar previously selected and semen samples were processed using the straw freezing procedure. In experiment 1, subsamples of semen were frozen in three different extenders: recommended lactose egg yolk extender (LEY); trehalose egg yolk extender (TEY) and glucose egg yolk extender (GEY). Sperm quality was assessed for motility, viability, acrosome integrity and hypoosmotic swelling test response upon collection, after freezing and thawing and then every hour for 3h. Results showed that total motility at 1 and 3h, progressive motility at 3h, positive hypoosmotic response at 2 and 3h and acrosome integrity at all times were significantly improved when trehalose was added to the extender. In experiment 2, sugar influence was also demonstrated in vitro fertilization. A total of 1691 oocytes were in vitro matured and inseminated with frozen-thawed sperm at 2000:1 sperm:oocyte ratio and coincubated for 6h. Presumptive zygotes were cultured in NCSU-23 medium to assess fertilization parameters and embryo development. Both penetration and monospermy rates were significantly higher for trehalose frozen semen. A significant increase was observed in efficiency and blastocyst formation rates from TEY to the other groups. Our results demonstrated that trehalose extender enhances spermatozoa viability and its in vitro fertilization parameters in boar ejaculates with good sperm freezability. Further studies are necessary to assess the impact of sugars on the entire population.

Anti-oxidant supplementation improves boar sperm characteristics and fertility after cryopreservation: comparison between cysteine and rosemary (Rosmarinus officinalis).

Anti-oxidants partially ameliorated the detrimental effects of reactive oxidative substances produced during cryopreservation. The objective of the study was to determine the effect of anti-oxidant addition to the freezing extender on boar semen qualities and fertility capacity. Ejaculates were collected from a previously selected boar and semen samples were processed using the straw freezing procedure. In experiment 1, semen samples were cryopreserved in lactose-egg yolk solution supplemented with various concentrations of cysteine (0, 5 and 10mM) to determinate a cysteine concentration capable of producing a protective effect during cryopreservation. Semen quality (total motility, progressive motility, viability, acrosome integrity and hypoosmotic swelling test) was evaluated after freezing and thawing and then every hour for 3h. In experiment 2, ejaculates were cryopreserved with lactose-egg yolk extender with or without the following anti-oxidants: cysteine, rosemary (Rosmarinus officinalis) and cysteine plus rosemary. Semen quality was evaluated. In the experiment 3, fertility capacity of semen frozen in anti-oxidant supplementation extenders was examined in vitro. A total of 2232 oocytes were in vitro matured and inseminated with frozen-thawed sperm. In summary: (i) the effective concentration of cysteine in freezing extender was 10mM; (ii) the addition of exogenous rosemary or cysteine to the freezing extender positively affected post-thawed viability and acrosome integrity. Only rosemary supplementation improved total motility at 3h and progressive motility at any time; (iii) the inclusion of rosemary into the extender was effective in penetration and cleavage rate and also in the efficiency of the fertilization system.

Preservation of the spermatozoa of the dromedary camel (Camelus dromedarius) by chilling and freezing: The effects of cooling time, extender composition and catalase supplementation.

This study sought to determine the characteristics of dromedary camel sperm following 24 h chilling and cryopreservation, testing two different buffers and cryoprotectants and the presence of catalase (500 IU/mL). Ejaculates were liquefied in Tris-Citric acid-Fructose buffer, and centrifuged through a colloid. For Experiment 1 (n = 5) sperm were cooled 24 h in Green Buffer or INRA-96® containing 0 or 3% glycerol or ethylene glycol. Experiment 2 (n = 5) used the same six treatments to evaluate sperm cryopreserved after 24 h cooling. A test of fertility was run (n = 12 recipients) with split ejaculates of fresh semen cooled 24 h in Green Buffer with and without glycerol. Experiment 3 (n = 7) cryopreserved sperm cooled 2 and 24 h in Green Buffer without cryoprotectant and with and without catalase. Sperm parameters measured before and after treatments included motility, viability and acrosome integrity. Experiment 1 showed no reduction in all sperm parameters after 24 h and no differences between buffers or presence or not of either cryoprotectant. Experiment 2 showed Green Buffer to be better than INRA for supporting sperm frozen after 24 h cooling while, for both buffers, there were few differences in sperm parameters if cryoprotectant was present or absent. Pregnancies were confirmed in 4/6 animals (67%) while no recipients receiving sperm chilled with glycerol were pregnant. In Experiment 3, catalase-supplemented sperm had maintained better motility 2 h post thaw; there were no differences between 2 or 24 h cooled sperm parameters for presence or absence of catalase. There was neither advantage nor disadvantage to coooling sperm 24 h prior to cryopreservation. We concluded that dromedary sperm can be chilled (24 h) and then either inseminated or cryopreserved. While glycerol presence in Green Buffer during chilling did not interfere with cryosurvival it may be toxic to the fertility of fresh chilled sperm. Catalase supplementation during cooling helps maintain sperm motility post thaw.

Optimization of a vitrification protocol for hatched blastocysts from the dromedary camel (Camelus dromedarius).

The objective of this study was to modify and optimize a vitrification protocol (open pulled straw) that was originally designed for human oocytes and embryos, to make it suitable for the cryopreservation of camel hatched blastocysts. The original open pulled straw protocol was a complex process with 15-minute exposure of oocytes/embryos in 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (Me2SO) for equilibration, and cooling in 16% EG + 16% Me2SO + 1 M sucrose. Recognizing a need to better control the cryoprotectant (CPA) concentrations, while avoiding toxicity to the embryos, the effects on the survival rate and developmental potential of camel embryos in vitro were investigated using two different methods of loading the CPAs into the embryos (stepwise and semicontinuous increase in concentration), two different loading temperature/time (room temperature ∼24 °C/15 min and body 37 °C/3 min), and the replacement of Me2SO with EG alone or in combination with glycerol (Gly). A total of 145 in vivo-derived embryos were subjected to these processes, and after warming their morphological quality and integrity, and re-expansion was assessed after 0, 2, 24, 48, 72, and 96 hours of culture. Exposure of embryos in a stepwise method was more beneficial to the survival of embryos than was the semicontinuous process, and loading of CPAs at 37 °C with a short exposure time (3 minutes) resulted in an outcome comparable to the original processing at room temperature with a longer exposure time (15 minutes). The replacement of the Me2SO + EG mixture with EG only or a combination of EG + Gly in the vitrification medium significantly improved the outcome of all these evaluation criteria (P < 0.05). The modified protocol of loading EG at 37 °C for 3 minutes has increased the embryo survival of the original protocol from 67% to 91% and the developmental rate from 57% to 83% at 5-day culture. These results were comparable to or better than those reported in human or other species, indicating that this optimized method is well suited to any commercial embryo transfer program in the dromedary camel.

Ontogeny of Na+/D-glucose cotransport in guinea-pig jejunal vesicles: only one system is involved at both 20 degrees C and 35 degrees C.

The kinetic parameters of Na+/D-glucose cotransport were examined in fetal, newborn and adult guinea-pig jejunal brush-border membrane vesicles using a displacement curve and non-linear regression procedure. Our data indicated the presence of a single system with a Km of 0.34 +/- 0.04 mM at both 20 degrees C and 35 degrees C. Vmax was increased by about 4-fold when the kinetic experiments were performed at 35 degrees C. Since our results were not in agreement with the findings of Brot-Laroche et al. (J. Biol. Chem. (1986) 261, 6168-6176) which indicated the existence of a distinct D-glucose transport system in the adult guinea-pig jejunum at 35 degrees C, we verified the influence of their experimental conditions on initial rate uptake measurements. In the presence of D-sorbitol instead of D-mannitol in the transport media, 70% inhibition of D-glucose uptake was observed, an effect which was attributable to contamination of sorbitol preparations by D-glucose. After removal of glucose contamination D-sorbitol did not significantly reduce the initial rate of D-glucose transport. These results led us to conclude the existence of a single D-glucose transport system in the guinea-pig small intestine and to stress the choice of experimental conditions as being crucial for an accurate estimation of kinetic parameters.

Kinetic evidence for heterogeneity in Na+-D-glucose cotransport systems in the normal human fetal small intestine.

Zero-trans kinetic studies of Na+-D-glucose cotransport have been performed under voltage-clamped conditions in brush-border membrane vesicles isolated from both jejunum and ileum of 17-20-week-old normal human fetuses. Varying glucose concentrations in the incubation medium led to curvilinear Eadie-Hofstee plots in the jejunum only, thus suggesting the presence of both high-affinity, low-capacity (Km 0.37 mM; Vmax 8.3 nmol/min per mg protein) and low-affinity, high-capacity (Km 4.2 mM; Vmax 30.9 nmol/min per mg protein) systems in the proximal small intestine, and of a single carrier (Km 1.2 mM; Vmax 4.9 nmol/min per mg protein) in the distal small intestine. Sodium activation curves provide further evidence for heterogeneity in glucose transport systems in the fetal small intestine: Hill coefficients of 2 and 1 were found for the jejunal high-affinity and ileal systems, and for the jejunal low-affinity system, respectively. It is concluded that there is early differentiation of a functional heterogeneity in glucose transport capacity along the human fetal small intestine.

Separation of two distinct Na+/D-glucose cotransport systems in the human fetal jejunum by means of their differential specificity for 3-O-methylglucose.

Based on kinetic arguments, we have recently proposed the existence of two distinct Na+/D-glucose cotransporters in brush-border membrane vesicles isolated from the human fetal jejunum (Biochim. Biophys. Acta 938 (1988) 181-188). In order to further test this hypothesis, inhibition studies of the zero-trans influx of substrate have been performed under Na(+)-gradient and voltage-clamped conditions. Initial rates of D-glucose uptake were totally abolished by D-glucose, D-galactose, alpha-methylglucose and phlorizin while 3-O-methylglucose and phloretin induced only a 65% inhibition even at the highest concentrations used. The residual activity of D-glucose uptake is thus compatible with substrate flux through a low-affinity transport system which is insensitive to phloretin and does not accept 3-O-methylglucose as substrate. This substrate specificity has been used to separate kinetically the two putative pathways for glucose transport. The data obtained are compatible with the existence of the following two systems: (i) a low-affinity, high-capacity system with a Km of 4.7 mM and a Vmax of 22 nmol/min per mg of protein, and; (ii) a high-affinity, low-capacity system with a Km of 0.57 mM and a Vmax of 10.7 nmol/min per mg of protein. These data thus demonstrate clearly the existence of two distinct Na(+)-dependent D-glucose carriers in the human jejunum during the early gestation period since these systems can be differentiated not only by their kinetic properties but also by their differences in both substrate and inhibitor specificities.

Proximo-distal gradient of Na+-dependent D-glucose transport activity in the brush border membrane vesicles from the human fetal small intestine.

Brush-border membrane vesicles were isolated from the jejunum and ileum of 17-20-week-old normal human fetuses and found to be highly enriched in sucrase activity with less than 5% contamination by basolateral membranes. Time course studies of D-glucose uptake clearly showed a transient, phlorizin-sensitive, and Na+-dependent accumulation of sugar into these vesicles. Higher maximum overshoot values and initial rates of D-glucose uptake were recorded in jejunal as compared to ileal vesicles while low substrate binding to the membranes, identical intravesicular volumes and equivalent dissipation of the Na+-gradient were found in the two preparations. It was concluded that a fully functional Na+-D-glucose cotransport system is present with a proximo-distal gradient of activity during the early gestation period.

The Quebec Adolescent Refugee Project: psychopathology and family variables in a sample from 35 nations.

OBJECTIVE: This study presents the results of a psychiatric epidemiological survey using a sample of adolescents from refugee families. METHOD: The sample included 203 adolescents, aged 13 to 19 years, coming from 35 countries. Psychopathology was assessed with the Diagnostic Interview Schedule for Children Version 2.25 and general functioning with the Children's Global Assessment Scale (CGAS). RESULTS: The total rate of psychopathology excluding simple phobia was 21% compared with 11% in a province-wide survey of young adolescents. Overanxious disorder had a high prevalence of 13%. The rates of major depression and conduct disorders were also high, at 5% and 6%. The rate of 3% of attempted suicide was similar to the rate found in Montreal high schools. Girls had a higher rate of psychopathology than boys, with a gender ratio similar to the one found in the provincial survey. Father's long-term unemployment in the first year of settlement was associated with psychopathology for the whole sample, and family structure was associated with psychopathology for boys only. CONCLUSIONS: The high rate of psychopathology in this group confirmed results from other surveys with similar samples. On the other hand, the CGAS scores indicated that many of the adolescents with a diagnosis had good social adaptation.

Alkaline phosphatase and peptidase activities in Caco-2 cells: differential response to triiodothyronine.

Caco-2 cell human colon adenocarcinoma cell line was used to study the hormonal regulation of small intestinal epithelial cell differentiation. We had previously shown that insulin-transferrin-selenium and triiodothyronine (5 x 10(-8) M)-supplemented medium can best replace serum after 2 days of culture for both the maintenance and differentiation of Caco-2 cells. The present study demonstrates that precoating petri dishes with complete serum allows the growth and differentiation of Caco-2 cells seeded directly in serum-free medium. On the other hand, precoating with dialyzed serum inhibits alkaline phosphatase and dipeptidyl-dipeptidase IV activities by more than 50%. The results obtained with complete serum-precoated culture plates indicate that there is no synergy between insulin and triiodothyronine because cells maintained in transferrin-selenium and triiodothyronine-supplemented medium, with or without insulin, express comparable enzyme activities. Moreover, large increases in alkaline phosphatase and dipeptidyl-dipeptidase IV activities were observed when triiodothyronine was added to the culture medium by the time confluency was reached. In contrast, gamma-glutamyltransferase was lowered to a greater extent when triiodothyronine was present from the beginning of culture. These findings show that triiodothyronine preferentially stimulates alkaline phosphatase and dipeptidyl-dipeptidase IV activities during the differentiation period whereas it selectively inhibits gamma-glutamyltransferase during the proliferation phase. Triiodothyronine acts in a dose-dependent manner.