Novel axial dynamic mechanical analysis setup for thermo-analytical study and curing kinetics optimization of thermoset adhesives.

Thermo-analytical studies of thermoset adhesives, either during research and development or in quality assurance activities, involve the application of various analytical equipment for adhesive characterization, from initial mixing to final product decomposition. Gelation is usually measured with rheometers or dynamic mechanical analyzers (DMAs); curing, post-curing, and curing kinetics are often studied using differential scanning calorimetry (DSC). Glass transition temperature (Tg) is measured via DSC or DMA, and finally, thermal decomposition measurements are done using thermal gravimetric analysis. Here, we present a new curing kinetics optimization module (C-KOM), an extension to an axial DMA, and a protocol for its usage, which combines elements from all of the above thermo-analytical techniques into one tool. As a case study, we apply C-KOM to investigate the effect of the curing temperature on the physical properties of an epoxy adhesive including gelation and end of cure points as well as its Tg. The data collected via C-KOM were used to extract the adhesive's curing reaction rates and its activation energy. Our research allowed us to compare and evaluate previously suggested curing procedures and assess their validity. As a final step, the thermal decomposition temperature of the epoxy adhesive was also identified via C-KOM. The newly suggested C-KOM setup provides a fast path toward characterization and optimization of the curing processes of thermoset materials in a way that was not available before.

Arthrogryposis in children: Etiological assessments and preparation of a protocol for etiological investigations.

INTRODUCTION: Arthrogryposis is a descriptive term defining a sign. It describes a set of joint contractures, sometimes identifiable in utero, present from birth and nonprogressive. This term includes a heterogeneous group of diseases, of neurological, neuromuscular, genetic or mechanical origin. The common physiopathological mechanism is fetal immobility syndrome. Two types of classification have been developed: a clinical one (types I, II and III) and an etiological one. The main aim of this study was to define a standardized protocol for etiological investigation based on a descriptive analysis of the various etiologies identified in a population of children followed up for arthrogryposis. Its secondary aim was to assess first the comprehensiveness and relevance of the complementary assessment and second the way in which the classifications proposed by Professor Judith Goslin Hall are applied. MATERIAL AND METHODS: Retrospective multicenter observational study. We enrolled pediatric patients with arthrogryposis being treated at a reference center for neuromuscular diseases, i.e., in three university hospital pediatric neurology units, between February 1997 and January 2017. RESULTS: Forty-two patients (25 boys and 17 girls) were enrolled. According to the clinical classification (Hall et al.), this population consisted of eight cases of type 1 arthrogryposis (19.1%), 14 type II (33.3%) and 20 type III (47.6%). The main etiology was neurological (19.1%), predominantly involving problems with gyration of a polymicrogyria type. Myopathic origin accounted for 9.5% of the population, predominantly involving genotyped distal arthrogryposis (ECEL1 gene). Additional tests produced a diagnosis of 25% type I, 43% type II and 75% type III. CONCLUSION: Arthrogryposis is a sign suggesting multiple etiologies. The main ones are neurological. Several genes have recently been identified, explaining the physiopathological mechanisms. The diagnostic process must be rigorous and coordinated within a multidisciplinary team, following a shared protocol for analysis.

[Fragile X syndrome and white matter abnormalities: Case study of two brothers]. / Syndrome de l'X fragile et anomalies de la substance blanche : à propos d'une fratrie.

Fragile X syndrome is the most usual cause of hereditary intellectual deficiency. Typical symptoms combine intellectual deficiency, social anxiety, intense emotional vigilance, and a characteristic facial dysmorphy. This is subsequent to a complete mutation of the FMR1 gene, considering a semidominant transmission linked to the unstable X. The expansion of the CGG triplet greater than 200 units combined with a high methylation pattern lead to a transcriptional silence of the FMR1 gene, and the protein product, the FMRP, is not synthesized. This protein is involved in synaptic plasticity. Brain MRI can show an increased volume of the caudate nucleus and hippocampus, combined with hypoplasia of the cerebellar vermis. Fragile X Associated Tremor Ataxia Syndrome (FXTAS) syndrome is a neurodegenerative disorder occurring in carriers of the premutation in FMR1. Brain MRI shows an increased T2 signal in the middle cerebellar peduncles. This syndrome is linked to a premutation in the FMR1 gene. We report here the case of two brothers presenting a typical fragile X symptomatology. Brain MRI showed hyperintensities of the middle cerebellar peduncles. Such MRI findings support the assumption of a genetic mosaicism.

An oocyte donation protocol using the GnRH antagonist ganirelix acetate, does not compromise embryo quality and is associated with high pregnancy rates.

PURPOSE: To evaluate the effect of the GnRH antagonist, ganirelix acetate, on oocyte quality. METHODS: Stimulation characteristics, implantation rates and clinical pregnancy rates were compared between 29 oocyte donors 21-31 years of age who underwent 31 cycles of ovarian stimulation with gonadotropins and ganirelix acetate, and 36 infertile couples of similar age range who underwent 51 cycles of ovarian stimulation using the same protocol. RESULTS: A significantly lower number of embryos were transferred in the donor/recipient group as compared to the infertile group (2.32+/-0.54 vs. 2.82+/-0.71, P<0.05). In contrast, implantation and clinical pregnancy rates per transfer, were significantly higher in the donor/recipient group (38.1% vs. 10.4%, P<0.01) and (61.3% vs. 23.1%, P<0.05) respectively, as compared to the infertile group. CONCLUSIONS: Incorporation of ganirelix acetate for pituitary suppression in stimulation protocols for oocyte donation is associated with high pregnancy rates suggesting that ganirelix acetate does not exert an adverse effect on oocyte or embryo quality.

Successful management of infertility due to retrograde ejaculation using assisted reproductive technologies: a report of two cases.

Although retrograde ejaculation is a relatively uncommon cause of infertility, it is nonetheless the most common cause of ejaculatory dysfunction. Retrograde ejaculation is characterized by either all or part of the seminal fluid going into the bladder. The initial management of patients with ejaculatory dysfunction is medical therapy. In couples who have failed medical therapy, assisted reproductive techniques using sperm harvested from either the urine or the male reproductive tract would be the ultimate option. We report successful management of two couples, both men with advanced age and complete retrograde ejaculation, by intrauterine insemination in one and in vitro fertilization (IVF) using intracytoplasmic sperm injection (ICSI) in the other using sperm harvested from urine. The cases reported herein suggest that male infertility due to retrograde ejaculation may be successfully treated in men significantly older than the usual reproductive age and that traditional methods of hydration and urine alkalinization allow for the successful recovery of fertile sperm for ART. The selection of the method of ART must be individualized to the needs of each couple based upon both male and female factors.

The human pluripotent stem cell: impact on medicine and society.

OBJECTIVE: To discuss the current state of the science surrounding human pluripotent stem cells and to show that the derivation of such cells from donated preimplantation human embryos should be eligible for federal funding provided that certain protections are met. DESIGN: A literature search focusing on the scientific aspects of pluripotent stem-cell research and analyses of current and past legislation and federal panel recommendations. CONCLUSION(S): The current federal laws regulating the permission necessary to obtain fetal tissue from elective pregnancy terminations are intended to insulate the decision to terminate a pregnancy from the potential positive influence of fetal tissue transplantation. A similar situation can be created for the derivation of cells from excess preimplantation human embryos produced by IVF programs. If, as in fetal tissue research, assurances can be made that the research will have no influence on the decision to dispose of the embryo, the derivation of pluripotent stem cells from embryo should proceed with federal funding.

Clinical significance of the qualification of atypical squamous cells of undetermined significance: An analysis on the basis of histologic diagnoses.

OBJECTIVE: This study was undertaken to evaluate the significance of further qualification of atypical squamous cells of undetermined significance in routine Papanicolaou smears. STUDY DESIGN: A retrospective medical records review was conducted on 316 women whose Papanicolaou smears yielded diagnoses of either atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion or atypical squamous cells of undetermined significance suggestive of a reactive process. RESULTS: The overall incidence of a squamous intraepithelial lesion (cervical intraepithelial neoplasia grades I, II, and III) was higher in the group with atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion than in the group with results suggestive of a reactive process (41.1% vs 22.3%; P =.0344). Women with atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion were 9.7 times more likely to have high-grade squamous intraepithelial lesion (cervical intraepithelial neoplasia III) develop than were women with atypical squamous cells of undetermined significance suggestive of a reactive process (95% confidence interval, 1.26-74.64). The incidence of high-grade squamous intraepithelial lesion was higher among women 35 years old (17.8% vs 6.3%; P =.0378). CONCLUSION: Women with a diagnosis of atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion are more likely to have intraepithelial lesions develop than are those with atypical squamous cells of undetermined significance suggestive of a reactive process. Aggressive evaluation of cases of atypical squamous cells of undetermined significance suggestive of the presence of an intraepithelial lesion with colposcopy and cervical biopsies may be appropriate. Age should be considered as an independent factor in the plan of management.

Reproductive function in female mice lacking the gene for endothelial nitric oxide synthase.

Nitric oxide (NO) acts as a neuronal messenger in both the central and peripheral nervous systems and has been implicated in reproductive physiology and behavior. Pharmacological inhibition of nitric oxide synthase (NOS) with the nonspecific NOS inhibitor, l-N(G)-nitro-Arg-methyl ester (l-NAME), induced deficits in both the number of ovarian rupture sites and the number of oocytes recovered in the oviducts of mice. Female neuronal NOS knockout (nNOS-/-) mice have normal numbers of rupture sites, but reduced numbers of oocytes recovered following systemic injections of gonadotropins, suggesting that NO produced by nNOS accounts, in part, for deficits in ovulatory efficiency observed after l-NAME administration. Additionally, endothelial NOS knockout (eNOS-/-) mice have reduced numbers of ovulated oocytes after superovulation. Because endothelial NOS has been identified in ovarian follicles, and because of the noted reduced breeding efficiency of eNOS-/- mice, the present study sought to determine the role of NO from eNOS in mediating the number of rupture sites present after ovulation. Estrous cycle length and variability were consistently reduced in eNOS-/- females. The number of rupture sites was normal in eNOS-/- mice under natural conditions and after administration of exogenous GnRH. After exogenous gonadotropin administration, eNOS-/- females displayed a significant reduction in the number of ovarian rupture sites. Female eNOS-/- mice also produced fewer pups/litter compared to WT mice. These data suggest that NO from endothelial sources might play a role in mediating rodent ovulation and may be involved in regulation of the timing of the estrous cycle.

Impaired ovulation in mice with targeted deletion of the neuronal isoform of nitric oxide synthase.

BACKGROUND: Nitric oxide (NO) plays an important role in numerous reproductive processes. To date, most studies have assessed the role of NO by using nonspecific pharmacological inhibitors of the precursor to NO, nitric oxide synthase (NOS). These pharmacological NOS inhibitors suppress all isoforms of NOS; thus, the precise contribution of each isoform to female reproductive physiology is unknown. The purpose of this study was to determine the specific role of neuronal NOS (nNOS) in the regulation of ovulation in female mice lacking the gene that encodes for nNOS (nNOS-/-). MATERIALS AND METHODS: Ovulation was assessed in wild-type (WT) and nNOS-/- female mice by examining the number of ovarian rupture sites and number of oocytes recovered from the oviducts following mating or exposure to exogenous gonadotropins (i.e., 5 IU pregnant mares serum gonadotropin [PMSG] and 5 IU human chorionic gonadotropin [hCG]). Ovulatory efficiency was determined as the number of ovulated oocytes per number of ovarian rupture sites. To examine whether ovulatory deficits in nNOS-/- mice were due to alternations in central mechanisms, plasma luteinizing hormone (LH) concentrations were assessed in WT and nNOS-/- mice that were challenged with 25 ng of gonadotropin-releasing hormone (GnRH). To determine whether ovulatory deficits in nNOS-/- mice were due to local ovulation processes, nerves innervating the reproductive tract of WT and nNOS-/- females were examined for the presence of nNOS protein. RESULTS: There were substantial fertility deficits in nNOS-/- female mice; the nNOS-/- mice had fewer oocytes in their oviducts following spontaneous and gonadotropin-stimulated ovulation. Pituitary responsiveness to exogenous GnRH challenge was intact in nNOS-/- mice. Dense nNOS protein staining was observed in nerves innervating the reproductive tracts of WT mice. CONCLUSIONS: The reproductive deficits in nNOS-/- females are most likely due to alternations in the transfer of oocytes from the ovaries to the oviducts during ovulation. These results suggest that defects in neuronally derived NO production may contribute to female infertility.

Day 4 estradiol levels predict pregnancy success in women undergoing controlled ovarian hyperstimulation for IVF.

OBJECTIVE: To evaluate the usefulness of serum estradiol levels obtained on the fourth day of gonadotropin stimulation in predicting the likelihood of pregnancy during controlled ovarian hyperstimulation (COH) using luteal phase leuprolide acetate (LA). DESIGN: A 4-year retrospective analysis of day 4 estradiol levels and subsequent clinical pregnancy and delivery rates. SETTING: A university hospital tertiary referral center. PATIENT(S): Couples undergoing IVF treatment. MAIN OUTCOME MEASURE(S): Primary outcome measures included clinical pregnancy and delivery rates. Secondary outcome measures included the number of oocytes retrieved and the number of embryos available for transfer per COH cycle. RESULT(S): The clinical pregnancy and delivery rates for cycles with day 4 estradiol levels of >75 pg/mL were 42.3% (30/71) and 32.4% (23/71), respectively. These rates differed significantly from those for cycles with day 4 estradiol levels of < or = 75 pg/mL, which were only 9.1% (4/44) and 6.8% (3/44), respectively. The number of oocytes retrieved and the number of embryos available for transfer for cycles with day 4 estradiol levels of >75 pg/mL also differed significantly from those for cycles with day 4 estradiol levels of < or = 75 pg/mL (11.4 and 7.8 versus 6.8 and 4.3, respectively). CONCLUSION(S): Estradiol levels obtained on the fourth day of gonadotropin therapy are highly predictive of successful ovulation induction and pregnancy outcome in cycles using luteal phase LA.

Nitric oxide modulates human chorionic gonadotropin-induced ovulation in the rabbit.

OBJECTIVE: To examine the potential role of the L-arginine:nitric oxide pathway in hCG-induced ovulation in the rabbit. DESIGN: Randomized, controlled animal study. SETTING: University research laboratory. INTERVENTION(S): Nitric oxide synthase, the enzyme that produces nitric oxide (NO), was immunohistochemically localized in the ovary. NG-nitro-L-arginine methyl ester (L-NAME), an analogue of L-arginine, which inhibits the enzyme NO synthase, and the inactive D-enantiomer were administered in vivo and/or in vitro via an isolated, perfused ovary preparation during the periovulatory period. MAIN OUTCOME MEASURE(S): Rate of follicular rupture (ovulatory efficiency). RESULT(S): Immunohistochemical staining for NO synthase was localized specifically to the granulosa cell layer of the follicle and the endothelium and adventitia of ovarian blood vessels. In vivo administration of L-NAME significantly reduced the percentage of large follicles that ovulated in response to hCG (treated 24.6%, control 68.1%). Similarly, exposure of the in vitro-perfused ovary to L-NAME significantly reduced follicular rupture (treated 32.8%, control 64.2%). In contrast, addition of an equimolar concentration of D-NAME to the perfusion medium had no significant effect on the rate of ovulation (treated 83.3%, control 61.3%). CONCLUSION(S): The stereospecific inhibition of follicular rupture by the arginine analogue suggests that NO production by the ovary is an important feature of the normal physiologic processes of the periovulatory period.

Effects of a gonadotropin-releasing hormone analog on rabbit ovarian function.

This study was undertaken to elucidate the effects of a GnRH analog (GnRH-a) on rabbit ovulation, oocyte maturation, and steroidogenesis, and to verify whether treatment with a GnRH-a interferes with ovarian response to exogenous gonadotropin (hCG), both in vivo and in vitro. Three approaches were used. In the first, adult New Zealand White (NZW) rabbits were divided into two groups. Both received PMSG and hCG administered 72 h after PMSG. In the test group a GnRH-a, leuprolide acetate (LA; 20 microg/kg) was administered s.c. every 24 h. Treated rabbits showed a significant decrease in ovulatory efficiency (control = 88%; treated = 72%), and an increase in degeneration rate of preimplantation embryos (control = 30% vs. treated = 40%). For the second approach, in vitro perfusion experiments were designed to compare the direct effects of LA (10.000 ng/ml) and hCG (50 IU) on ovarian function and to verify whether the presence of a GnRH-a in the perfusate modifies the actions of hCG. LA reduced the ovulatory efficiency of hCG-treated ovaries perfused in vitro (hCG-treated = 87%; hCG-treated LA-perfused = 70%), reduced the potential for preimplantation development (morula stage: hCG-treated = 53%; hCG-treated LA-perfused = 31%; LA-perfused = 12%), and increased the degeneration rate of early embryos (21%, 48%, and 56% respectively). In the third approach, the direct effect of LA (Group I: control, Group II:1.000 ng/ml, and Group III:10.000 ng/ml) on the in vitro maturation of denuded rabbit oocytes was evaluated. LA induced meiotic maturation, but increased oocyte degeneration rate. The potential for preimplantation development was reduced (Morula stage: control = 16%, Group II = 8%, and Group III = 6%), and degeneration rate was increased (38%, 65%, 63% respectively). This study suggests that pharmacological doses of LA may exert a negative effect on oocyte function by direct action on the oocyte, indirectly via alteration of the intrafollicular environment and/or through interference with gonadotropin-induced biological effects within the ovary.

Anti-islet autoantibodies detected by monoclonal antibody 1A2: further studies suggesting a role in the pathogenesis of IDDM.

Insulin-dependent diabetes mellitus (IDDM) is associated with autoantibodies to several pancreatic islet antigens. We have described an assay in which autoantibodies displace a radiolabelled monoclonal anti-islet antibody. Sera from 87% of 429 children at time of diagnosis of IDDM were positive, while sera from control groups had much lower prevalences (1.3-19%). Sera from 41.9% of diabetic subjects remained positive after 20 years duration of IDDM. Sera from 23.6% of parents and 37.9% of non-diabetic siblings were positive. Twenty relatives who subsequently developed IDDM had the same prevalence of the antibodies (85%) as did the patients at time of diagnosis. These findings confirm that the autoantibodies detected by monoclonal antibody (mAb) 1A2 are common at the onset of IDDM and their presence prior to the onset of hyperglycaemia suggests that this method may be useful in screening non-diabetic populations. The high prevalence of antibodies in relatives reduces the efficacy for diabetes prediction, but suggests either that generation of these antibodies is an autosomal dominant trait, or that the antigen detected by these antibodies is cross-reactive with a common environmental antigen. Differentiation between these hypotheses will await the identification of the specific islet-cell antigen detected by mAb 1A2.

Effects of acetylsalicylic acid (aspirin) and naproxen sodium (naproxen) on ovulation, prostaglandin, and progesterone production in the rabbit.

OBJECTIVE: To determine the effects of acetylsalicylic acid (aspirin) and naproxen sodium (naproxen) on ovulation, ovarian prostaglandins (PG), and P production in the rabbit via in vivo and in vitro studies. DESIGN: Aspirin and naproxen were administered i.v. 6.5 and 7 hours, respectively, after hCG administration to New Zealand White adult female rabbits. Laparotomy was performed 24 hours after hCG administration. For in vitro experiments, control animals underwent laparotomy 6.5 (aspirin) and 7 hours (naproxen) after hCG administration. The treated animal received aspirin and naproxen; laparotomy was performed 1 hour later. One ovary was perfused for 6 hours with aspirin or naproxen whereas the contralateral ovary served as a control and was perfused with control medium (M199; GIBCO, Grand Island, New York). Perfusate samples were collected at 1-hour intervals for PG and P determination. SETTING: A conventional laboratory setting. INTERVENTIONS: In vivo experiments used i.v. administration of 100 mg/kg aspirin and 10 and 50 mg/kg naproxen. In vitro perfusion was also carried out with 100 micrograms/mL aspirin and 10 and 50 micrograms/mL naproxen added to the perfusate. MAIN OUTCOME MEASURES: Ovulatory efficiency (no. of ovulations/no mature follicles) and ovarian vein PG and P concentration were determined. RESULTS: Ovulatory efficiency was 88% for control, 41% for in vivo aspirin-treated, and 40% (10 mg/kg) and 0% (50 mg/kg) for naproxen-treated rabbits. Aspirin and naproxen were associated with decreased ovulatory efficiency when administered in vitro to both in vivo control and in vivo treated ovaries (control-medium = 70%; control-aspirin = 14%; aspirin-medium = 34%; aspirin-aspirin = 0%; control-naproxen = 25%; naproxen-medium = 38%; naproxen = 0% with 10 microgram/mL, and control-naproxen = 13%; naproxen-medium = 0%; naproxen = 0% with 50 micrograms/mL). Prostaglandin F2 alpha was undetectable in the perfusate of those ovaries perfused of those ovaries perfused either with aspirin or naproxen. Ovarian venous concentration of P in the perfusate was similar in all groups. CONCLUSIONS: Aspirin and naproxen significantly reduced ovulatory efficiency and PG production both in vivo and in vitro in hCG-treated rabbits. A critical period of 6.5 and 7 hours after hCG administration was established.

RU486 inhibits ovulation, fertilization and early embryonic development in rabbits: in vivo and in vitro studies.

OBJECTIVE: To clarify the role of P in ovulation, fertilization, and early embryonic development using RU486, a potent P receptor blocker. DESIGN: Ovulatory efficiency, IVF, and early embryonic development were evaluated after RU486 administration in vivo and in vitro. SETTING: Research laboratory of a university hospital. PARTICIPANTS: Mature male and female New Zealand white rabbits. INTERVENTIONS: Animals were treated with RU486 or vehicle for 3 days before hCG-induced ovulation. Ovaries treated with hCG to induce ovulation were perfused for 6 hours in vitro with RU486 or vehicle. In vitro fertilization was performed in the presence or absence of RU486. MAIN OUTCOME MEASURES: The percentage of mature follicles ovulating (ovulatory efficiency) was determined after in vivo and in vitro treatment. Fertilization, morula, and blastocyst development were evaluated every 24 hours for 120 hours. RESULTS: RU486 significantly inhibited ovulation, fertilization, and early embryonic development. CONCLUSIONS: Progesterone plays a significant role in ovulation, fertilization, and preimplantation embryonic development.