bluuebunny/crossref_metadata_2025_split huggingface dataset:
Digital examination and transperineal ultrasonographic measurement of cervical length to assess risk of preterm delivery
Authors: Önderoğlu L.S 
Published: July 2002

AbstractObjective: To compare the diagnostic performance of cervical length measurement determined with transperineal ultrasonography and digital assessment of the cervix for the prediction of preterm delivery in patients with preterm labor. Method: 90 patients admitted to the hospital with the diagnosis of preterm labor and intact membrane underwent cervical length measurement by transperineal ultrasonography along with digital examination for cervical dilatation and effacement. The main outcome measure was delivery before 37 weeks' gestation. Results: 32 patients (35.5%) delivered preterm. Receiver operative characteristic curve analysis revealed that cervical canal length ≤28 mm measured by transperineal sonography had the highest diagnostic performance with a sensitivity of 78.1% and specificity of 82.7%. The sensitivity and specificity of digital examination were found to be 65.5%, 72.4% and 62.5%, 68.9% for the cervical dilatation>2 cm and effacement≥40%, respectively. Conclusion: Transperineal ultrasonographic examination for cervical length is more accurate than digital examination for prediction of preterm delivery in patients presenting with preterm labor. Transperineal ultrasonographic examination of cervix is invaluable in the prediction of preterm delivery where transvaginal transducers are lacking or skilled staff are unavailable.
Fetal blood flow redistribution in term intrauterine growth retardation (IUGR) and post‐natal growth
Authors: Yoshimura S. , Masuzaki H. , Miura K. , Gotoh H. , Ishimaru T. 
Published: July 2002

AbstractObjective: The purpose of the present study was to evaluate the relationship between intrauterine growth retardation, represented by fetal blood flow redistribution and infantile growth. Methods: The blood flow velocity waveform of umbilical and middle cerebral arteries was recorded by Doppler ultrasonography in 77 growth‐retarded fetuses. We recorded the pulsatility index (PI) of the umbilical artery and middle cerebral and calculated the PI ratio of the middle cerebral to umbilical artery (C/U ratio). We selected a cutoff value of 1.0 to distinguish between normal and abnormal C/U ratios. To evaluate the development of infants, height, body weight and head circumference were measured serially at 3, 6 and 12 months of age. Results: Birth weight was significantly lower in newborns who had abnormal C/U ratios (2021 ± 295 g vs. 2294 ± 236 g). The number of cases admitted to NICU was higher and the duration of admission was longer in abnormal C/U ratio group (15/29 and 33.7 ± 13.5 days) than normal C/U ratio group (7/48 and 26.6 ± 5.6 days). Body weight was lower in infants of abnormal C/U ratio group at 3 months, but was not different at 6 and 12 months. The height was shorter in abnormal C/U ratio group at birth, there were no significant differences at 3, 6 and 12 months. The number of newborn infants with growth retardation was slightly higher in abnormal C/U ratio group, but the difference was not significant at 6 and 12 months. There was no relationship between C/U and growth variables recorded at birth and follow‐up in infants. Conclusion: Intrauterine growth‐retardation, represented by abnormal fetal blood redistribution was associated with adverse perinatal outcome, but the influence was not found at the first year of life.
Collaboration between industry and academia — prospects for male fertility control
Authors: Stock G. , Habenicht U.‐F. 
Published: July 2002

AbstractDrug development within the pharmaceutical industry is probably the field with the highest level of regulations. Due to the complexity of the different components of drug development and drug surveillance the need for a sophisticated organization and infrastructure is obvious. In addition, there is a necessity for sufficient resources and long‐term commitment as well as logistic and long‐term knowledge management. In order to secure high professional standards at all levels of this highly complex value creating chain, the number of cooperative arrangements in the pharmaceutical industry are increasing. The identification of new targets in the drug finding process calls in particular for outside partners. At the same time the preparedness of non‐industrial researchers to cooperate with industry has also increased significantly. The area of fertility control, especially male fertility control, provides an excellent example for this kind of cooperation between industrial and non‐industrial partners. Here a cooperative network is described which probably meets practically all relevant criteria for both the non‐industrial but also the industrial partner. Some principles for the management of such a cooperative network are discussed. We believe that this kind of network can serve as a model for similar networks in other fields.
The past, present and future
Authors: Diczfalusy E. 
Published: July 2002

AbstractMy generation has seen more progress in science and technology than all preceding generations together. We have also witnessed several intellectual, technological, medical and social revolutions spearheaded by the contraceptive revolution and followed by those in reproductive health, gender equity, information, communication, globalization, international assistance, etc. The results of the first contraceptive revolution were spectacular, by 1990 some 900 million couples used contraception, which became a global lifestyle. When this revolution lost momentum, a new departure took place: the Rockefeller Foundation's Contraception‐21 initiative. The major achievements of this initiative are presented in this volume. All papers represent a significant contribution also to the ultimate objective: the achievement of human dignity for every woman. The revolutions mentioned above profoundly changed the world and our perception of it. They will also assist humankind in deconstructing the deterministic worldview of past centuries and replacing it with a science‐driven anthropocentric philosophy.
Intrapartum fetal distress and magnesium sulfate
Authors: Vigil‐De Gracia P , Simitı́ E , Lora Y 
Published: July 2002

AbstractObjective: Intrapartum fetal distress is an obstetric emergency traditionally managed by immediate delivery by either the vaginal route or cesarean section. However, there is usually time to attempt intrauterine resuscitation. The purpose of this study was to report the utilization of magnesium sulfate for intrauterine resuscitation. Method: Twenty‐one fetuses received magnesium sulfate 4‐g intravenous bolus in mothers awaiting cesarean section for fetal distress in the labor room of the Complejo Hospitalario Metropolitano de la Caja de Seguro Social de Panamá, from March through August 1997. Fetal distress in labor was defined as the presence of repetitive late decelerations, persistent loss of baseline variability, severe variable decelerations, or bradycardia. Results: Twenty‐one fetuses received magnesium sulfate 4‐g intravenous bolus in mothers awaiting cesarean section for fetal distress. Uterine activity ceased in seven patients, diminished in 13 patients and did not change in one. In all cases, but one, there was recovery of the FHR within 4 min; furthermore there was rose reactive of FHR in nine patients. The 1‐min Apgar scores were 7 or above in 18 cases and the 5‐min Apgar scores were 7 or above in 20 patients. Conclusions: In summary, magnesium sulfate may be useful in the management of acute intrapartum fetal distress when there is evidence of increased uterine activity.
Depletion of cortical target induced by prenatal ionizing irradiation: effects on the lateral geniculate nucleus and on the retinofugal pathways
Authors: Schmidt Sergio L. , Vitral Renan W.F. , Linden Rafael 
Published: July 2002

AbstractStudies using neonatal surgical lesions to reduce the target area of the retina have supported the idea that developing axons show only a limited specificity in their targeting. This investigation tested whether retinogeniculate axons adjust for partial target depletion by repositioning of axons. We used adult Swiss mice exposed to γ rays at the time when layer IV cells are generated in the ventricular zone (16 days of gestation). Nissl‐stained brain sections were used for histological analyses in thalamus and cortex. Retinal ganglion cells were backfilled from the optic tract with horseradish peroxidase. Intraocular injections of horseradish peroxidase were used to study the retinal projections. In the posterior cortex there was a nearly complete absence of layer IV. The irradiated animals showed a 75% reduction of the dorsal lateral geniculate nucleus. The ventral division, superior colliculus, and other visually related nuclei were not affected. The loss in the ganglion cells (15.7%) was significant but clearly smaller than that observed in the dorsal lateral geniculate nucleus (75%). Therefore, the shrinkage of the dorsal lateral geniculate nucleus led to a reduction in the area available for retinal projections. Despite partial target loss, pattern of retinal projections did not differ from that of the controls. The effect on the dorsal lateral geniculate nucleus is discussed in the light of differences between prenatal and neonatal damage of the presumptive visual cortex. The absence of aberrant retinal projections suggests that repositioning of axons is not the first mechanism employed by retinal axons to match connections in numerically disparate populations.
Disturbance of neuronal plasticity is a critical pathogenetic event in Alzheimer's disease
Authors: Arendt Thomas 
Published: July 2002

AbstractBrain areas affected by AD pathology are primarily those structures that are invovled in the regulation of “higher brain functions”. The functions these areas subserve such as learning, memory, perception, self‐awareness, and consciousness require a life‐long re‐fittng of synaptic contacts that allows for the acquistion of new epigenetic information, a process based on a particularly high degree of structural plasticity. Here, we outline a hypothesis that it is the “labile state fo differentiation” of a subset of neurons in the adult brain that allows for ongoing neuroplastic processes after development is completed but at the same time renders these neurons particularly vulnerable. Mechanisms of molecular and cellular control of neuronal differentiation and proliferation might, thus, not only play a role during development but critically involved in the pathogenesis of neurodegeneration.
Time course of the effects of prenatal gamma irradiation on the dorsal lateral geniculate nucleus of Swiss mice
Authors: Abreu‐Villaça Yael , Schanuel Sheine Menezes , Schmidt Sergio Luis 
Published: July 2002

AbstractA previous study reported that adult mice irradiated at the 16th embryonic day present a severe neuronal number reduction in the dorsal lateral geniculate thalamic nucleus. In the present study, we investigated the time course of the effects of prenatal irradiation on this thalamic nucleus. One day after irradiation, a great number of pyknotic figures were seen mainly in the cerebral proliferative zones. In the geniculate nucleus, only scattered pyknotic figures were identified. On the first week after birth, the geniculate nucleus presented frequent pyknotic figures. From five days after birth onwards, a severe shrinkage of the occipital cortex and a great reduction in the geniculate nucleus neuronal number were found. On the second week after birth this neuronal number reduction reached as high as 75%. At each postnatal analyzed age, severe volumetric geniculate nucleus shrinkage was combined to non‐significant neuronal density variations. The presence of few pyknotic figures in the geniculate nucleus one day after irradiation and its delayed neuronal loss indicate an indirect effect of irradiation. We suggest that the effect upon the geniculate nucleus is secondary to the damage of the occipital cortex. A possible interpretation for thalamic neuronal loss is that geniculate neurons fail to establish cortical arbors after major target loss. In this case, the loss of trophic support should also be considered.
Development and maturation of noradrenaline‐containing nerves of the rat uterine artery. Effects of acute and chronic oestrogen treatment.
Authors: Corbacho A.M. , Brauer M.M. , Pérez T. 
Published: July 2002

AbstractThe development and maturation of noradrenaline‐containing nerves of the rat uterine artery was investigated, histochemically and biochemically, at seven different postnatal age‐stages and following acute and chronic treatment with oestradiol. Morphological changes in the vessel were quantitatively evaluated on toluidine blue‐stained semithin sections and low magnification electronmicrographs. In summary, the uterine artery is innervated at birth; the adult pattern of innervation is established at two weeks of age; the innervation density increases progressively between the infantile and prepubertal periods, accompanying proliferation and growth of smooth muscle cells in the tunica media; changes in the innervation are followed by an increase in the tissue concentration of noradrenaline and neither the endocrine changes characterizing puberty nor acute or chronic treatment with oestradiol have an effect on the pattern of development of the uterine artery and associated noradrenaline‐containing nerves. Results are interpreted considering the differential susceptibility of urinogenital organs to sex hormones.
Identifying the G protein, Gzα, and its associated proteins in nervous tissue using mass spectrometry and microsequencing techniques
Authors: Bartlett Selena E. , Hendry Ian A. 
Published: July 2002

AbstractThe signalling pathway associated with pertussis and cholera toxin sensitive G proteins have been extensively investigated. In contrast, the function and associated signal transduction cascade for the pertussis toxin insensitive G protein, Gzα, has remained elusive. Therefore, the aim of this study was to identify the signal transduction pathway associated with Gzα by using the protein identification techniques of matrix assisted laser desorption ionization‐time of flight mass spectroscopy and N‐terminal Edman sequencing. We have chosen this technique to identify proteins that Gzα associates with and to gain insights into the potential role this G protein plays in cells. As Gzα is predominantly localized in neuronal tissues, homogenates of whole brain tissue were used. Gzα and its associated proteins were immunoprecipitated from brain tissue and identified. The immunoprecipitation of four proteins (140, 46, 41 and 36 kDa) was shown to be inhibited in the presence of the Gzα peptide. These proteins were subsequently identified as phospholipase C (PLC)‐γ, β or γ‐actin, Gzα and Gβ, the β subunit of heterotrimeric G proteins, respectively. These results suggest that Gzα exists in a protein complex with the actin cytoskeleton and an important intracellular signalling enzyme, PLC‐γ. These methods are powerful techniques for determining protein–protein interactions, and provides the first step to the identification of signalling proteins that Gzα associates with. However further experimentation will be required to determine the biological relevance of these protein interactions.
Temporal pattern of plasminogen activator activity in the developing chick cerebellum
Authors: Scicolone G. , Pereyra‐Alfonso S. , Sanchez V. , Flores V. 
Published: July 2002

AbstractPlasminogen activators are considered to be involved in several developmental events. The present work aims at characterizing the developmental pattern of expression of plasminogen activators in the chick cerebellum.Soluble fractions derived by ultracentrifugation from Triton X‐100 treated membrane fractions were used for determination of the enzyme activity with a radial fibrinolytic assay. By using specific inhibitors and different anti‐plasminogen activators antibodies it is shown that only one type of the enzyme, the urokinase‐type plasminogen activator, is expressed during the cerebellum ontogeny. Our results show the existence of a bimodal pattern of enzyme activity with two peaks that temporally coincide with the processes of massive neuronal migration, neurite outgrowth and synapse formation and plasticity. It is proposed that plasminogen activator could play a role in these developmental events and that its pattern of variability is developmentally regulated.
Expression of the low affinity neurotrophin receptor, P75NGFR, in the rat forebrain, following unilateral bulbectomy
Authors: Turner Christopher P. , Perez‐polo J.Regino 
Published: July 2002

AbstractIt has been hypothesized that the main olfactory bulb, with its relatively rich source of neurotrophins, may provide trophic support for neurons that project to the bulb. We monitored expression of the common, low affinity receptor for neurotrophins, p75NGFR, in the olfactory bulb and basal forebrain of unilaterally bulbectomized and sham‐treated rats, 1–16 weeks post‐surgery, using the monoclonal antibody MAb192. An induction of p75NGFR‐immunoreactivity was observed in both the glomerular and olfactory nerve layers of the right, contralateral main olfactory bulb of lesioned animals. The naturally occurring regeneration taking place in the olfactory neuroepithelium is known to be altered by olfactory bulbectomy, with subsequent changes in the sensory input to the remaining bulb. These changes in expression of p75NGFR in the olfactory bulb support the hypothesis we have developed in previous papers, that changes in the extent of the peripheral input from the olfactory neuroepithelium to the main olfactory bulb regulate p75NGFR expression in both the glomerular and the olfactory nerve layers. Expression of p75NGFR in the basal forebrain of bulbectomized animals was found to be no different than sham‐treated controls and does not support the hypothesis that the olfactory bulb provides trophic support to this region of the central nervous system.
Stress and the adaptive self‐organization of neuronal connectivity during early childhood
Authors: Huether Gerald 
Published: July 2002

AbstractA conceptual framework is proposed for a better understanding of the biological role of the stress‐response and the relationship between stress and brain development. According to this concept environmental stimuli (in children mainly psychosocial challenges and demands) exert profound effects on neuronal connectivity through repeated or long‐lasting changes in the release of especially such transmitters and hormones which contribute, as trophic, organizing signals, to the stabilization or destabilization of neuronal networks in the developing brain. The increased release of noradrenaline associated with the repeated short‐lasting activation of the central stress‐responsive systems in the course of the stress‐reaction‐process to psychosocial challenges which are felt to be controllable acts as a trigger for the stabilization and facilitation of those synaptic and neuronal pathways which are activated in the course of the cognitive, behavioral and emotional response to such stressors. The long‐lasting activation of the central stress‐responsive systems elicited by uncontrollable psychosocial conflicts in conjunction with the activation of glucocorticoid receptors by the sustained elevation of circulating glucocorticoid levels favors the destabilization of already established synaptic connections and neuronal pathways in associative cortical and limbic brain structures. The facilitation and stabilization of neuronal pathways triggered by the experience of controllable stress is thus opposed, attenuated or even reversed in the course of long‐lasting uncontrollable stress. This destabilization of previously established synaptic connections and neuronal pathways in cortical and limbic brain structures is a prerequisite for the acquisition of novel patterns of appraisal and coping and for the reorganization of the neuronal connectivity in the developing brain. Alternating experiences of repeated controllable stress and of long‐lasting uncontrollable stress are therefore needed for the self‐adjustment of neuronal connectivity and information processing the developing brain to changing environmental (psychosocial) demands during childhood. The brain structures and neuronal circuits involved in the regulation of behavioral responding become thus repeatedly reoptimized and refitted, not the changing conditions of life per se but rather to those conditions which are still able to activate the central stress responsive systems of an individual at a certain developmental stage.
Emigration of neuroepithelial cells from the hindbrain neural tube in the chick embryo
Authors: Sohal G.S. , Ali M.M. , Galileo D.S. , Ali A.A. 
Published: July 2002

AbstractIt is generally believed that after the emigration of neural crest, the neuroepithelial cells of the neural tube are committed to differentiate only as neurons and supporting cells of the central nervous system. Neural crest cells arise from the dorsal portion of the developing neural tube and contribute to the formation of the peripheral nervous system and a variety of non‐neural structures. In contrast to this view we have recently shown, by focal application of the vital dye Dil in duck embryos, that an additional population of cells emigrates from the neural tube. By using an entirely different technique we confirm and extend these observations in the chick embryo. Replication‐deficient retroviral vector LZ12 containing the gene LacZ was utilized to label the neural tube cells. The viral concentrate was microinjected into the lumen of the rostral hind‐brain neural tube, considerably after the completion of emigration of neural crest cells. The labeled cells were monitored in whole mounts and histological sections. Initially, the labeled cells were restricted to the neuroepithelium of the hindbrain neural tube. Subsequently, they were seen in the neural tube and in the ganglion of the fifth cranial nerve (trigeminal ganglion). Later, they migrated beyond the trigeminal ganglion, i.e., into the mesenchyme of the first pharyngeal arch. Immunostaining with the neural crest cell marker, HNK‐1, indicated that the emigrated neuroepithelial cells were HNK‐1 negative. It is concluded that in the chick embryo some neuroepithelial cells emigrate at the site of attachment of the trigeminal nerve, migrate into the ganglion and then into the mesenchyme of the first arch. This cell population differs antigenically from the neural crest cells.