Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “In Vitro”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 775 records · Page 43Linked to original sources
PubMed1999

Deliveries and children born after in-vitro fertilisation in Sweden 1982-95: a retrospective cohort study.

BACKGROUND: In-vitro fertilisation is an effective treatment for infertility, but there is concern about the health of children. We investigated, in a retrospective registry study, malformations, cancers, and deaths in the complete Swedish in-vitro-fertilisation birth cohort compared with the general population. METHODS: We collected data from all in-vitro-fertilisation clinics in Sweden and compared the obstetric outcomes of babies (n=5856) born between 1982 and 1995 with all babies born in the general population (n=1,505,724) during the same period, according to data from the Swedish Medical Birth Registry and the Registry of Congenital Malformations. We investigated the incidence of childhood cancer through the Swedish Cancer Registry. Data were stratified for maternal age, parity, previous subfertility, year of birth, and multiple of pregnancies. FINDINGS: Multiple births occurred in 27% of pregnancies compared with 1% in the control group. In the in-vitro-fertilisation group, more babies were born preterm (<37 weeks) than controls (30.3 vs 6.3%) and more had low birthweights (<2500 g, 27.4 vs 4.6%). The perinatal mortality was 1.9% in the in-vitro fertilisation group and 1.1% in the controls. For in-vitro-fertilisation singletons, the risk ratios, adjusted for year of birth, for very preterm birth (<32 weeks) and very low birthweight (<1500 g) were 3.54 (95% CI 2.90-4.32) and 4.39 (3.62-5.32), respectively. Malformations occurred in 5.4% of all babies in the in-vitro-fertilisation group (1.39 [1.25-1.54]), and the rates of neural-tube defects and oesophageal atresia were higher than those in the controls. There was no increase in childhood cancer in the in-vitro-fertilisation group. INTERPRETATION: A high frequency of multiple births and maternal characteristics were the main factors that led to adverse outcomes, and not the in-vitro-fertilisation technique itself. The clinical practice of in-vitro-fertilisation needs to be changed to lower the rate of multiple pregnancy.

Cohort Studies↗
PubMed2002

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗
PubMed1994

The cost of a successful delivery with in vitro fertilization.

BACKGROUND: The use of in vitro fertilization has engendered considerable debate about who should have the procedure, whether health insurance should cover the cost, and if so, to what extent. We investigated the cost of a successful delivery with in vitro fertilization. METHODS: We calculated the cost per successful delivery with in vitro fertilization (defined as at least one live birth) for a general population of couples undergoing in vitro fertilization and for two subgroups: couples with a diagnosis of tubal disease (who have a better chance of success), and couples in which the woman is over the age of 40 years and the man has a low sperm count (who have a lower chance of success). Information on charges per cycle of in vitro fertilization was obtained from six facilities across the country; delivery rates with this procedure were estimated from the literature. RESULTS: On average, the cost incurred per successful delivery with in vitro fertilization increases from $66,667 for the first cycle of in vitro fertilization to $114,286 by the sixth cycle. The cost increases because with each cycle in which fertilization fails, the probability that a subsequent effort will be successful declines. Sensitivity analyses indicated that the cost per delivery ranges from $44,000 to $211,940. For couples with a better chance of successful in vitro fertilization (i.e., those with a diagnosis of tubal disease), it costs $50,000 per delivery for the first cycle and $72,727 for the sixth. For couples in which the woman is older and there is a diagnosis of male-factor infertility, the cost rises from $160,000 for the first cycle to $800,000 for the sixth. CONCLUSIONS: The debate about insurance coverage for in vitro fertilization must take into account ethical judgments and social values. But analyses of costs and cost effectiveness help elucidate the economic implications of using in vitro fertilization and thus inform the policy discussion.

Adult↗
PubMed2003

Causes of developmental failure of in-vitro matured rhesus monkey oocytes: impairments in embryonic genome activation.

BACKGROUND: Understanding the causes of developmental failure of in-vitro matured primate oocytes may lead to viable strategies for improving their developmental competence. The aims of this study were to determine whether the timely onset of embryonic genome activation among individual blastomeres of preimplantation macaque embryos is impaired by in-vitro maturation (IVM) of oocytes and whether these impairments are associated with developmental failure during the embryonically controlled period of preimplantation development. METHODS: Genome activation among individual blastomeres was assessed using expression of fibrillarin as a marker of nucleolar transcription. Immature oocytes were obtained from rhesus monkeys following treatment with recombinant human FSH and matured in-vitro in one of two IVM media (CMRLa or CMRLb). In-vivo matured oocytes were obtained from FSH treated monkeys following administration of hCG. Oocytes were fertilized in vitro and either cultured for developmental studies or processed at the 8-12-cell stage for expression of fibrillarin. RESULTS: Developmental competence of embryos derived from in-vitro matured CMRLa oocytes was markedly (P < 0.05) impaired compared with those derived from in-vivo matured or in-vitro matured CMRLb oocytes. Developmental profiles were similar among the groups prior to the 8-cell stage. However, in embryos derived from in-vitro matured CMRLa oocytes, developmental failure increased significantly (P < 0.05) after the time of genome activation compared with those derived from in-vivo matured or in-vitro matured CMRLb oocytes. The mean percentages of non-activated blastomeres per embryo, as well as the proportions of embryos with at least one non-activated blastomere, or with no activated blastomeres, were all significantly (P < 0.05) greater in embryos derived from in-vitro matured CMRLa oocytes than in those derived from in-vivo matured or CMRLb oocytes. CONCLUSIONS: The relatively poor developmental competence of in-vitro matured primate oocytes is likely caused in part by failure in the timely onset of embryonic genome activation resulting from incomplete cytoplasmic maturation.

Animals↗
PubMed1999

Intercellular communication in in vivo- and in vitro-produced bovine embryos.

In vivo bovine embryos were obtained by nonsurgical flushing of uterine horns of cows submitted to superovulatory treatment, while in vitro embryos were generated from oocytes collected from slaughtered donors. Lucifer Yellow injected into single blastomeres did not diffuse into neighboring cells until the morula stage in in vivo embryos and the blastocyst stage in in vitro embryos. In both cases diffusion was limited to a few cells. In contrast, diffusion was extensive in microsurgically isolated inner cell mass (ICM) but absent in the trophectoderm (TE). At the blastocyst stage, diffusion was always more extensive in in vivo than in in vitro embryos. Ultrastructural analyses confirmed these functional observations, and gap junction-like structures were observed at the blastocyst stage. These structures were diffuse in the ICM of in vivo embryos, scarce in the ICM of in vitro embryos and in the TE of in vivo embryos, and not observed in the TE of in vitro embryos. Blastomeres at all stages of development from the 2-cell stage to the blastocyst stage in in vitro embryos and at the morula and blastocyst stage in in vivo embryos were electrically coupled, and the junctional conductance (Gj) decreased in in vitro embryos from 4.18 +/- 1.70 nS (2-cell stage) to 0.37 +/- 0.12 nS (blastocyst stage). At each developmental stage, in vivo embryos showed a significantly (P < 0. 05) higher Gj than in vitro-produced embryos. Moreover, a significantly (P < 0.01) higher Gj was found in isolated ICM than in the respective blastocyst in both in vivo- and in vitro-produced embryos (3.5 +/- 1.4 vs. 0.7 +/- 0.3 and 2.6 +/- 1.6 vs. 0.37 +/- 0. 12 nS, respectively). The electrical coupling in absence of dye coupling in the early bovine embryo agrees with observations for embryos from other phyla. The late and reduced expression of intercellular communicative devices in in vitro-produced embryos may be one of the factors explaining their developmental low efficiency.

Animals↗
PubMed2002

Oocyte maturation in vitro.

In contrast to conventional assisted reproduction techniques in which metaphase II oocytes are retrieved for fertilization in vitro, during the in-vitro maturation of oocytes, immature germinal vesicle stage oocytes are retrieved and matured in the laboratory before fertilization and embryo transfer. Whereas in-vitro maturation is technically more demanding than in-vitro fertilization it carries many potential advantages in terms of lower treatment costs and greater safety, as a result of reducing both the number of clinical consultations and the amount of pharmacological intervention. Although the technology is still experimental, in-vitro maturation has been successfully used for the treatment of patients with polycystic ovarian syndrome, and a number of pregnancies and live births have been reported. Despite these successes and much continuing research effort, the overall efficiency of in-vitro maturation remains low, and neither clinical nor laboratory procedures can be considered to be as robust and routinely feasible as conventional in-vitro fertilization techniques. The immediate goals for in-vitro maturation programmes are therefore to increase germinal vesicle oocyte recovery rates, optimize culture conditions, improve oocyte maturation potential, and after fertilization to produce pregnancy rates that are at least equivalent to those obtained using conventional in-vitro fertilization. This review focuses on the physiology and application of human oocyte maturation in vitro, and will detail the recent advances reported in this rapidly advancing field.

Cell Culture Techniques↗
PubMed1994

Comparison of in vivo and in vitro adjacent segment motion after lumbar fusion.

STUDY DESIGN: For in vitro studies, there is no basis for choosing a "load control study" over a "displacement control" study. This study qualitatively compared results from in vitro and in vivo tests, allowing the authors to address the experimental assumptions that in vitro testing contributes to the understanding of the in vivo condition. OBJECTIVES: To compare motion changes at segments adjacent to fusions for in vitro and in vivo tests. SUMMARY OF BACKGROUND DATA: Investigators have measured the effects of spinal fusions on the adjacent segment in a human cadaver model and found greater adjacent facet joint load after fusions. Others have found significant increases in motion and facet loads at segments adjacent to in vitro lumbosacral and long fusions, when the same range of motion was repeated before and after immobilization of lumbar segments. METHODS: L2-L3 motion was measured in vitro by an instrumented spatial linkage under load and displacement control before and after immobilization of segments (L3-L7). In vivo, L2-L3 motion was measured while animals walked on a treadmill. L3-L7 was fused and the L2-L3 motion testing was repeated. The change in in vivo adjacent segment motion was qualitatively compared with the in vitro change under "load" and "displacement" control. RESULTS: Under "load" control, in vitro facet motion did not significantly change after immobilization, whereas under "displacement" control, the facet motion significantly increased from 2.2 +/- 0.4 mm to 4.1 +/- 0.6 mm. Post-instrumentation, in vivo L2-L3 facet motion increased significantly. This change in vivo related better to the changes seen in the in vitro "displacement" control test than to the in vitro "load" control test.

Animals↗
PubMedDate not supplied

Development of a dry powder inhaler, the Ultrahaler, containing triamcinolone acetonide using in vitro-in vivo relationships.

Triamcinolone acetonide (TAA) is safe and effective corticosteroid that is marketed as an MDI (metered dose inhaler) (Azmacort) for the treatment of asthma. A novel dry powder inhaler (DPI), the Ultrahaler, has been developed to deliver Azmacort as another alternative to provide non-CFC formulation for the asthmatic patients. The Ultrahaler is breath actuated and, unlike MDI, does not require coordination of inhalation with the actuation of the device. However, with the Ultrahaler device, like any dry powder inhalation device, the challenge was the on-target and uniform delivery of the drug at the site of action (lungs) with different dose strengths. Due to the complexities of oral inhaled formulations and the topical nature of drug delivery to the lung for efficacy, the reformulation requires careful consideration and support throughout their development, using a combination of in vitro and in vivo studies. This paper describes in vitro studies and two clinical pharmacokinetic studies conducted in a sequence that helped to establish optimum doses for the Ultrahaler. In vitro data were used to guide the initial selection of doses that were then compared in vivo using a pharmacokinetic study with a charcoal block. The in vitro tests included quantifying the target-delivered dose, dose uniformity throughout the life of the device, and the particle size distribution. Particle size distribution was measured using multistage liquid impinger (MSLI) or the Andersen Cascade Impactor (ACI). For in vitro testing, TAA was measured by HPLC methods. Based on the preliminary in vitro data for the respirable fraction, dose strengths with an MDI and the Ultrahaler for the first study were determined. The in vivo assessment consisted of a four-way crossover study following oral inhalation using both MDI (75 and 225 microg/actuation, reference treatment) and comparable respirable doses in the DPI (130 and 360 microg/actuation) devices in healthy volunteers in the presence (lung deposition) and absence (lung and oropharynx deposition) of the charcoal block. Plasma TAA concentrations were determined using a radioimmunoassay (RIA) method. The in vitro data also showed dose proportionality with DPI formulation, and the doses delivered were within 13% of the target doses. A measure of dose uniformity, the relative standard deviation (%RSD) of dose, was less than 15%. Plasma TAA exposure of DPI formulations was compared with that of MDI formulations. Mean ratios (DPI/MDI) of the AUCinf were close to unity for the lower dose strength. However, for the higher dose strength, plasma exposure was higher with the Ultrahaler formulation as compared with the MDI formulation (mean AUCinf DPI/MDI ratios: 1.96). These differences seem to be due to less than proportional increases in the MDI formulation. Based on these results and using the higher dose strength of the MDI as the comparator, the new dose strengths of the Ultrahaler were chosen, ie, 100, 225, and 450 mug/actuation. Plasma TAA concentrations were measured by LC/MS/MS methods. The mean TAA concentrations and AUCinf and Cmax values increased in a dose-proportional manner with an increase in dose for the DPI formulation. The pharmacokinetic parameters showed low variability (10%-33%). Fine particle mass (in vitro testing) and TAA exposure in plasma following DPI administration were compared. Fine particle performance in vitro related well with in vivo pharmacokinetic performance (R=AUCinf-0.9998, Cmax-0.9956). In conclusion, in vitro and in vivo data were in agreement and good control over the target-dose delivery and dose proportionality could be achieved in the early stages of the development of the Ultrahaler device and were critical in guiding and ensuring the success of the reformulation efforts for Azmacort.

Administration, Inhalation↗
PubMed1995

Cyclosporine effects on in vitro responsiveness of anterior pituitary hormone release to dopamine and thyrotropin-releasing hormone in young female rats.

Endocrine side effects of the immunosuppressive drug cyclosporine (CyA) include changes in anterior pituitary hormone secretion. The aim of the present study was to examine the effects of CyA on the responsiveness of in situ and ectopic anterior pituitary prolactin (PRL), growth hormone (GH) and luteinizing hormone (LH) release response to dopamine (DA) and thyrotropin-releasing hormone (TRH) treatment in young female rats, and to evaluate the possible PRL participation in these effects. Thirty day old rats were rendered hyperprolactinemic by transplanting an anterior pituitary gland of a littermate donor, under the kidney capsule, and were then injected with CyA or vehicle for 2 or 8 days. Sham-operated rats were used as controls and treated in the same way. CyA treatment prevented the increase in plasma PRL levels which occurred in controls after pituitary grafting. In vitro basal PRL release of in situ pituitaries from either sham-operated and/or pituitary-grafted animals was decreased by CyA treatment at any point studied. Basal in vitro secretion of GH was only decreased in the in situ pituitaries from grafted animals after 2 days of CyA therapy. The presence of an ectopic pituitary lead to an increase in the in vitro basal LH secretion from in situ pituitaries as compared to those from sham-operated rats. Basal LH release rates were not changed by CyA treatment, although the LH release in vitro did increase in the in situ pituitaries from sham-operated animals treated with the drug for 2 days. DA addition to the incubation media decreased the in vitro release of PRL, GH and LH from the in situ pituitaries of sham-operated and pituitary-grafted animals treated with vehicle. In CyA treated animals, DA decreased in vitro PRL release from the in situ pituitaries of animals, independently of the presence or absence of an ectopic pituitary. Reductions of the in vitro GH and LH release release after DA treatment were higher in the in situ pituitaries from grafted animals on day 8 of CyA or vehicle treatment. TRH increased the in vitro release of the three hormones with differential effects related to the length of the treatment with CyA and/or the presence of an ectopic pituitary. In vitro release of PRL and GH by ectopic pituitaries was inhibited by previous treatment with CyA and this effect was decreased proportional to the duration of the treatment with the drug, while LH secretion was not modified. Addition of DA to the incubation media resulted in a marked reduction of in vitro PRL and GH release, but only at day 8 of vehicle treatment on GH release did DA addition to media further decrease the release of both hormones from ectopic pituitaries from animals treated for 2 or 8 days with the drug, whereas LH secretion was not modified. TRH addition to the incubation media of ectopic pituitaries surprisingly reduced PRL and GH secretion on day 8 of CyA treatment or after surgery. The results of these studies suggest that CyA can act directly at the hypophyseal level modifying pituitary responsiveness to external stimuli. CyA seems to exert its main effects on lactotroph activity while its effects on somatotrophs and gonadotrophs are less.

Animals↗
PubMed2004

Differentiation and developmental potential of rat post-implantation embryo without extra-embryonic membranes cultured in vitro or grafted in vivo.

Different experimental systems are used to study developmental processes in mammals. In this study, three experimental models were analysed and correlated: (1) cultivation of rat embryos in vitro; (2) cultivation in vitro and then transplantation in vivo; (3) direct transplantation in vivo. When embryos were cultivated in vitro and then transplanted in vivo, after the initial in vitro restriction, developmental potential was recovered. The in vitro restriction depended on medium used and duration of culture. Pre-cultivation in serum-free medium for 7 days restricted developmental potential for nervous tissue, and for 14 days restricted developmental potential for skeletal muscles, adipose tissue and glandular epithelia. Transferrin addition improved in vitro differentiation of neuroblasts, cartilage and columnar epithelium. In the combined in vitro and in vivo method, transferrin preserved developmental potential in comparable extent to the addition of the serum. Even in serum-free conditions in vitro, the subsequent in vivo wide expression of developmental potential was possible. Therefore, the combination of in vitro and in vivo methods turned to be advantageous than the isolated approaches (in vitro or in vivo only), and enabled testing in more detail the influence of a single substance on developmental course and potential.

Animals↗
PubMed2001

Mechanisms underlying the depression of evoked fast EPSCs following in vitro ischemia in rat hippocampal CA1 neurons.

The mechanisms underlying the depression of evoked fast excitatory postsynaptic currents (EPSCs) following superfusion with medium deprived of oxygen and glucose (in vitro ischemia) for a 4-min period in hippocampal CA1 neurons were investigated in rat brain slices. The amplitude of evoked fast EPSCs decreased by 85 +/- 7% of the control 4 min after the onset of in vitro ischemia. In contrast, the exogenous glutamate-induced inward currents were augmented, while the spontaneous miniature EPSCs obtained in the presence of tetrodotoxin (TTX, 1 microM) did not change in amplitude during in vitro ischemia. In a normoxic medium, a pair of fast EPSCs was elicited by paired-pulse stimulation (40-ms interval), and the amplitude of the second fast EPSC increased to 156 +/- 24% of the first EPSC amplitude. The ratio of paired-pulse facilitation (PPF ratio) increased during in vitro ischemia. Pretreatment of the slices with adenosine 1 (A1) receptor antagonist, 8-cyclopenthyltheophiline (8-CPT) antagonized the depression of the fast EPSCs, in a concentration-dependent manner: in the presence of 8-CPT (1-10 microM), the amplitude of the fast EPSCs decreased by only 20% of the control during in vitro ischemia. In addition, 8-CPT antagonized the enhancement of the PPF ratio during in vitro ischemia. A pair of presynaptic volleys and excitatory postsynaptic field potentials (fEPSPs) were extracellularly recorded in a proximal part of the stratum radiatum in the CA1 region. The PPF ratio for the fEPSPs also increased during in vitro ischemia. On the other hand, the amplitudes of the first and second presynaptic volley, which were abolished by TTX (0.5 microM), did not change during in vitro ischemia. The maximal slope of the Ca(2+)-dependent action potential of the CA3 neurons, which were evoked in the presence of 8-CPT (1 microM), nifedipine (20 microM), TTX (0.5 microM), and tetraethyl ammonium chloride (20 mM), decreased by 12 +/- 6% of the control 4 min after the onset of in vitro ischemia. These results suggest that in vitro ischemia depresses the evoked fast EPSCs mainly via the presynaptic A1 receptors, and the remaining 8-CPT-resistant depression of the fast EPSCs is probably due to a direct inhibition of the Ca(2+) influx to the axon terminals.

Animals↗
PubMed1997

In vivo/in vitro comparison of rat abdominal aorta wall viscosity. Influence of endothelial function.

Arterial wall viscosity (AWV) is a potential source of energy dissipation in circulation. That arteries, which are known to be markedly viscous in vitro, have lower viscosity in vivo has been suggested but not demonstrated under similar pressure conditions. Endothelium, which may modulate AWV through smooth muscle tone, could contribute to the low level of viscosity in vivo. Our objectives were first to compare AWV of the rat abdominal aorta, in vivo and in vitro, with similar pulse-pressure waves, and second, to determine whether endothelial function influences AWV in vivo and in vitro. The diameter of the abdominal aorta and distending pressure were measured in vivo and in vitro with a high-resolution echotracking system and a micromanometer, respectively. AWV was calculated as the area of the pressure-volume curve hysteresis. After in vivo examination, the arterial segments were isolated in vitro and submitted to resynthesized pressure waves identical to those recorded in vivo. Deendothelialization was performed in vivo by balloon rubbing; then arteries were examined either in vivo or in vitro. AWV was markedly lower in vivo than in vitro (6.6 +/- 0.7 versus 22.7 +/- 3.7 J.m-1.10(-5), respectively; P < .001). After deendothelialization, a sustained 40% increased AWV was observed during a 15-minute follow-up (P < .01). In vitro, deendothelialized arteries have a 64% higher AWV than segments with endothelium (P < .01). Our results indicate that the physiological effective viscosity, measured in vivo in intact animals, is threefold lower than the intrinsic viscosity of the arterial wall, measured in vitro. Endothelium removal determines a sustained increase in AWV, either in vivo or in vitro. These results suggest that active mechanisms compensate for intrinsic viscosity under physiological conditions. One of these energy-saving mechanisms might be dependent on normal endothelial function.

Animals↗
PubMed2001

Transmission electron microscopy studies of the zona reaction in pig oocytes fertilized in vivo and in vitro.

The aim of this study was to determine the ultrastructure of cross-sectioned zonae pellucidae of in vitro-matured and ovulated pig oocytes before or after sperm penetration in vitro and in vivo, respectively. The in vitro and in vivo (ovulated) oocytes and zygotes (fertilized in vitro and in vivo) were fixed with glutaraldehyde either directly or after pretreatment with ruthenium red and saponin, processed and then examined using transmission electron microscopy. The thickness of the zona pellucida, as measured on the section of the specimens with largest diameter fixed with glutaraldehyde, differed between the in vivo (9.19 +/- 0.47 microm) and in vitro (5.95 +/- 0.51 microm) oocytes. The in vivo oocytes had a rather thick external mesh-like structure, whereas it was much thinner in the in vitro oocytes. This mesh-like external rim was less apparent in both in vivo and in vitro zygotes. Obvious differences in the density of the lattice formed by the fixed zonae pellucidae were visible between the outer and inner (ad-oolemmal) zonae. The outer area always formed a concentrically arrayed fibrillar network, whereas the inner area showed a much more compact, trabecule-like mesh. However, both areas, but particularly the outer network, were much more compacted after the zona reaction. Clear differences in the degree of fibrillar aggregation of the inner zona area were also observed between in vitro and in vivo zygotes, being much higher in the latter. This fibrillar network was more clearly visible in the zygotes pretreated with ruthenium red and saponin; the in vitro zygotes had a fibrillar, radially oriented set of parallel fibrils, whereas it was much more aggregated and trabecule-like in the in vivo zygotes. These results demonstrate that the fine structure of the zona pellucida and the zona reaction at sperm penetration differ between pig oocytes fertilized in vivo and in vitro. Moreover, the ultrastructure of the outer and inner pig zonae pellucidae has a different network organization.

Animals↗
PubMed2006

Cerebral palsy among children born after in vitro fertilization: the role of preterm delivery--a population-based, cohort study.

OBJECTIVE: Our aim was to assess the incidence of cerebral palsy among children conceived with in vitro fertilization and children conceived without in vitro fertilization. METHODS: A population-based, cohort study, including all live-born singletons and twins born in Denmark between January 1, 1995, and December 31, 2000, was performed. Children conceived with in vitro fertilization (9255 children) were identified through the In Vitro Fertilization Register; children conceived without in vitro fertilization (394,713) were identified through the Danish Medical Birth Register. Cerebral palsy diagnoses were obtained from the National Register of Hospital Discharges. The main outcome measure was the incidence of cerebral palsy in the in vitro fertilization and non-in vitro fertilization groups. RESULTS: Children born after in vitro fertilization had an increased risk of cerebral palsy; these results were largely unchanged after adjustment for maternal age, gender, parity, small-for-gestational age status, and educational level. The independent effect of in vitro fertilization vanished after additional adjustment for multiplicity or preterm delivery. When both multiplicity and preterm delivery were included in the multivariate models, preterm delivery remained associated strongly with the risk of cerebral palsy. CONCLUSIONS: The large proportions of preterm deliveries with in vitro fertilization, primarily for twins but also for singletons, pose an increased risk of cerebral palsy.

Adult↗
PubMed2006

Health of children born as a result of in vitro fertilization.

OBJECTIVE: The purpose of this study was to use nationwide registries to examine the health of children up to 4 years of age who were born as a result of in vitro fertilization. METHODS: Children born after in vitro fertilization (N = 4559) from 1996 to 1999 were monitored until 2003. Two control groups were selected from the Finnish Medical Birth Register as follows: all other children (excluding children born after ovulation induction) from the same period (N = 190,398, for study of perinatal health and hospitalizations) and a random sample of those children (n = 26,877, for study of health-related benefits). Mortality rates and odds ratios for perinatal outcomes, hospitalizations, health-related benefits, and long-term medication use were calculated. RESULTS: Although the health of most in vitro fertilization children was good, such children had more health problems than other children. A total of 35.7% of in vitro fertilization children and 2.2% of control children were multiple births, and the health of multiple births was worse than that of singletons. Perinatal outcomes of in vitro fertilization children were worse and hospital episodes were more common than among control children. Risks for cerebral palsy and psychological and developmental disorders were increased. Among in vitro fertilization singletons, worse results for perinatal outcomes and hospitalizations, but no increased risk for specific diseases, were found. The health of in vitro fertilization multiple births was comparable to the health of control multiple births. CONCLUSIONS: Reducing the number of transferred embryos would improve the health of in vitro fertilization children. Additional studies are needed to explain the poorer health of in vitro fertilization singletons, as well as follow-up studies to examine the health of in vitro fertilization children from 4 years onward.

Child, Preschool↗
PubMed1986

Comparison of plasma free-fatty-acid and blood-glycerol concentrations with measurement of lipolysis in porcine adipose tissue in vitro.

Rates of adipose tissue lipid metabolism in vitro are often measured to evaluate the function in vivo of metabolic pathways and thus appraise the accretion or loss of depot fat. This study directly addressed the comparison of degradative metabolism in vitro and in vivo. The concentrations of plasma free-fatty-acids and blood-glycerol as putative representatives of lipolysis in vivo and the lipolytic rate in adipose tissue in vitro obtained at the time of blood sampling were both measured in the same pig. Concentrations of plasma free-fatty-acids and blood-glycerol were increased or decreased by infusion of the norepinephrine analog, isoproterenol or by infusion of the adrenergic antagonist, propranolol, respectively. Although lipolytic rates and sensitivity to isoproterenol in vitro changed during some acute hormonal manipulations of the pig, the modulation in vitro was usually small relative to the large changes observed in plasma free-fatty-acid and blood-glycerol concentrations. Some of the subtle changes in vitro may reflect biological responses to hormone infusion, e.g., desensitization of the response to adrenergic agonists, but the magnitude of rate changes in vitro negates prediction of the rates in vivo from rates in vitro. Extrapolation of lipolytic rates in vitro and several adipose tissue anabolic rates obtained from the literature indicate the improbability for prediction of rates and degree of fat accretion in pigs from metabolic rates in vitro.

Adipose Tissue↗
PubMed1999

Study of evaluation criteria used for in vitro bovine oocyte selection and maturation.

Production of bovine preimplantation embryos in vitro requires beneficial maturation conditions and high quality oocytes at the germinal vesicle stage. The current classification of oocytes is based on character of the cumulus cell investment around the oocyte. We wished to study the nuclear stage of immature oocytes selected for in vitro maturation according to cumulus cell character and, in the other hand, to compare the relationship among 3 parameters utilized to evaluate in vitro maturation of bovine oocytes (degree of cumulus expansion, meiotic maturation rate and in vitro fertilization rate) when fetal calf serum, steer serum and bovine follicular fluid supplementation were used. Ovaries were collected at an abattoir and the oocytes harvested. As regards selection criteria, immature oocytes were classified as Class A, B, C and D according to the character of the cumulus cells. A high percentage of Class A oocytes (87.7%) were in the germinal vesicle stage with respect to the other classes (p < 0.05). Significant differences were found in the meiotic maturation rate in Class A oocytes (76.5%) versus those of the other classes (p < 0.05). The meiotic maturation rate diminished to 47.5% when Class A oocytes were denuded and then matured in vitro (p < 0.05). As regards maturation criteria, there was no cumulus expansion when oocytes were matured in TCM-199 without supplementation, partial expansion with the addition of fetal calf serum and full expansion when supplemented with steer serum or bovine follicular fluid. No significant differences were found in the meiotic maturation rate for the various treatments. In vitro fertilization rate was significantly lower in media without supplementation versus supplemented media (p < 0.05), but no significant differences were found between the supplemented media inter se. There is no direct relationship between the three studied parameters to evaluate in vitro maturation. Class A oocytes are the most likely to mature in vitro as they not only have a close association with their surrounding cumulus cells, but are also very numerous in the germinal vesicle stage. The degree of cumulus expansion and the meiotic maturation rate have a relative importance in evaluating in vitro maturation, as oocyte maturation implies not only nuclear events but also at other cellular levels, as evaluated by in vitro fertilization.

Animals↗
PubMed2002

Changes in the immunologic phenotype of human malignant glioma cells after passaging in vitro.

Although immunotherapeutic strategies against glioblastomas have been promising both in vitro and in animal models, similar successes have not been realized in human clinical trials. One reason may be that immunotherapeutic strategies are based on prior studies that primarily have used human glioblastoma cell lines passaged in vitro, which may not accurately reflect the in vivo properties of glioblastoma cells. In this report, we used flow cytometry to quantify the expression of immunological cell surface molecules on human glioblastomas directly ex vivo (prior to any in vitro culturing) and after varying passages in vitro. Furthermore, we used ELISA to quantitate cytokine secretion after various passages in vitro. We demonstrate that in vitro culturing of established cell lines led to increases in the cell surface expression of MHC class I and ICAM-1 and secretion of IL-6 and TGF-beta(2). Furthermore, there were significant changes in the expression of MHC class I, MHC class II, B7-2, ICAM-1, and FasL when comparing ex vivo tumor cells to those after a single passage in vitro. After passaging once in vitro, there were also significant changes in the secretion of TGF-beta(2) and IL-10. This report indicates that in vitro culturing leads to significant changes in both cell surface molecules and secreted cytokines, which are known to affect the ability of immune cells to initiate an anti-tumor immune response. These changes in the immunological phenotype of glioblastomas after in vitro culturing may in part explain the limited success of immunotherapeutic strategies against glioblastomas in human clinical trials.

Antigens, CD↗