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In the present study, we have examined the origin and growth pattern of the β cells in pancreatic islets, to determine whether a single progenitor cell gave rise to all the precursors of the islets, or if each of a few progenitor cells is the founder of a different islet, or if each islet is a mixture of cells originating from a pool of progenitor cells. Aggregation mouse chimaeras where the pancreatic β cells derived from each embryo can be identified in the islets on histological sections were analyzed. In two chimaeras, all the islets contained cells from both the aggregated embryo. This clearly demonstrates that each islet resulted from several independent cells. In addition, the β cells derived from either embryo component were in very small clusters in the islets, suggesting that in situ cell division did not account significantly for islet growth.

Vaginal bleeding in childhood is not a common complaint. Serious medical or sociological problems can underly this irregular symptom in young girls. Therefore it requires careful medical investigation followed by appropriate sociologic and psychologic support. The variable etiologies of vulvovaginitis are the most common causes of vaginal bleeding during the prepubertal period. External blood loss can be related to trauma or urologic factors. It can be the presenting sign of relatively rare benign and malignant neoplasms of the genital tract. Precocious menstruation in itself or as a part of precocious puberty must be suspected in these cases. Vaginal bleeding in prepubertal girls is uncommon but warrants careful evaluation because of the special status of the young patient.

A cross-sectional transvaginal ultrasound study was conducted in 137 normal pregnancies with gestational ages ranging from 5-12 weeks. Several biometric measurements were obtained throughout pregnancy, including the three diameters of the gestational sac, the crown-rump length, and the yolk sac. In addition, the appearance of the embryo heartbeat and embryo body movements were evaluated. Linear relationships were found between the mean gestational sac diameters and gestational age (r = 0.911; P less than .00001) and between mean gestational sac growth and crown-rump length growth (r = 0.926; P less than .0001). A gestational sac could be identified at 5 weeks' gestation; embryo heartbeat was imaged when the mean gestational sac diameter measured 2 cm, and embryo body movements could be seen when the mean gestational sac diameter reached 3 cm. In the present study, embryo heartbeat was identifiable after 6 weeks and 4 days with a sensitivity of 100%, specificity of 93.1%, positive predictive value of 96.9%, and negative predictive value of 100%. The embryo body movements, which were absent before 7 weeks' gestation, were observed after 8 weeks' gestation with a sensitivity of 100%, specificity of 92.8%, positive predictive value of 94.3%, and negative predictive value of 100%. With identification by transvaginal sonographic evaluation, the following can serve as markers of normal embryo growth: a mean gestational sac diameter greater than 2 cm in the presence of the embryo heartbeat, or a mean sac diameter measurement greater than 3 cm in the presence of embryo movement.

Embryos receiving either the Thp or the twLub2 mutation from their mother die during gestation. In contrast, heterozygous embryos receiving the mutant chromosome from the father are completely viable. In both Thp and twLub2 mutants, one chromosome 17 carries a deletion, which suggests the existence of a discrete maternal lethality effect locus (Tme). In the region whose deletion is responsible for the Thp or twLub2 mutation, a single gene has been cloned so far, the Tcp-1 gene. In the present study, we examined the expression of Tcp-1 gene in mutant embryos carrying either a maternal or a paternal Thp chromosome to test whether this gene could be involved in the Tme effect. We found that the levels of Tcp-1-specific transcripts were similar in both mutant embryos from reciprocal crosses and corresponded to half the levels found in the normal littermates. In addition, the paternal and maternal Tcp-1 alleles had identical methylation patterns. These results indicate that Tcp-1 is not responsible for the maternal lethality effect, and therefore is not located at the Tme locus.

By imposing mild restrictions on the analytic form of the probability density functions (PDFs) characterizing the model, the family of filtering problems for which exact recursive solutions are known is extended. It is shown that the recursive computation can be done with bounded complexity per iteration on the new family. This family has the potential to model many filtering problems. >

A total of 157 consecutive patients were studied in an effort to examine prospectively the incidence of asymptomatic intraamniotic infection in the early phase of the second trimester. All patients were referred for amniotic fluid karyotyping. In addition, the amniotic fluids were examined for Gram stain and were directly cultured on blood agar and MacConkey agar as well as in thioglycollate broth. We found positive amniotic fluid cultures in eight cases (5.09%); however, results of Gram stain examinations were negative in all amniotic fluid samples. The data indicate that there is no correlation between white blood cells in the amniotic fluid and positive amniotic fluid culture results. Only one pregnancy with positive amniotic fluid culture resulted in a septic abortion. Therefore we can suggest that intraamniotic infection can exist early in pregnancy, even with intact membranes, and in most cases without any clinical symptoms.

Sonographic growth curves of biparietal diameter (BPD), head circumference, abdominal circumference, head circumference/abdominal circumference ratio, and femur length were generated from 24 uncomplicated, concordant triplet pregnancies. These were compared with the standard curves derived for singletons used in our medical center. Slowing of BPD, head circumference, and abdominal circumference growth was noted in triplets from the 28th week of gestation, whereas the head circumference/abdominal circumference ratio was similar to that of singletons. Femur growth was parallel to that of singletons, although on the low margin of the two standard deviations. We conclude that the growth patterns of triplets are different from those of singletons. We suggest that femur length derived for singletons may be suitable for the follow-up of triplets. However, when growth retardation is suspected, the growth curves presented herein may be used to identify the growth-retarded fetus.

Free digoxin-like immunoreactive factor(s) (DLIF) which may have a homeostatic role, as documented in different physiological conditions, but is generally undetectable in plasma from normal population. Total digoxin-like immunoreactive factor(s) (protein bound and free) can be estimated after plasma is heated. In this study, total digoxin-like immunoreactive factor(s) as measured in plasma in a well defined control population and compared to healthy term pregnant women and neonates, categories known to be associated with increased free digoxin-like immunoreactive factor(s) concentrations. The mean level of this factor(s) in the control group was 706 +/- 129 pg digoxin equivalent/ml (pg/ml) and was unaffected by age and sex. Significantly increased levels of total digoxin-like immunoreactive factor(s) were found in pregnant women and neonates (928 +/- 127 and 1242 +/- 367 pg/ml, respectively). We conclude that levels of total digoxin-like immunoreactive factor(s) are increased in term pregnancies and neonates, similarly to its free form. However total digoxin-like immunoreactive factor(s) is detected in the normal population as a plasma component, contrary to its free form, which is generally undetectable.

Poly (ADP-ribosyl)ation is a covalent modification of many nuclear proteins. It has a strong chromatin modifying potential involved in DNA repair, transcription and replication. Its role during preimplantation development is unknown. We have observed strong but transient synthesis of poly ADP-ribose polymers on decondensing chromosomes of fertilized and parthenogenetically activated mouse oocytes. Inhibition of this transient upregulation with a specific enzyme inhibitor, 3-aminobenzamide, has long-term effects on the postimplantation development of the embryos. In addition, inhibition of poly (ADP-ribosyl)ation at the 4–8 cell stage selectively blocks morula compaction. These observations suggest that poly (ADP-ribosyl)ation is involved in the epigenetic chromatin remodeling in the zygote.

In mammals, the dynamic of Ca2+ oscillations induced by fertilization causes the remodeling of the parental chromosomes and activates the developmental processes. The objective of the present study was to evaluate whether the modulation of the regime of Ca2+ oscillations during the process of egg activation is capable of inducing specific chromatin modification. The sensitivity of chromatin modification during oocyte activation was evaluated by comparison of the methylation profile of Igf2r, the maternal allele of which is methylated, and H19, the maternal allele of which is unmethylated. Freshly ovulated mouse oocytes were parthenogenetically activated by a series of repetitive Ca2+ ion influxes induced by electropermeabilization of the plasma membrane in a microfluidic processor. The first treatment (T1) consisted of 24 electrical pulses (1.45kVcm−1) given every 8min for 3h in the presence of 100μM of Ca2+. The treated oocytes were almost all activated, 98% (328/338), and formed pronuclei 3 or 4h after the first pulse. The second treatment (T2) was made up of 16 electrical pulses of lower amplitude (1.12kVcm−1), given every 8 min for 2h under the same conditions. The rate of egg activation dropped to 29%, (86/298), and the time course of pronucleus formation was completed 7h after the first pulse. The remaining oocytes, 71% (212/298), extruded the second polar body, but their chromatin did not undergo full decondensation and then did not proceed further to pronucleus formation. The methylation profiles of the two imprinted genes were analyzed by using the bisulfite sequencing method. Oocytes that formed pronuclei after being subjected to either the T1 or the T2 treatment displayed methylation profiles of the two alleles similar to those of the non-treated oocytes. The Igf2r-DMR was found fully methylated on all 13 copies examined, and the H19 DMR was found mostly unmethylated (13 out of 19 copies; 6 were partially methylated). Thus, when parthenogenetic activation results in formation of a pronucleus the methylation profile of these two genes is maintained. In contrast, those from oocytes that responded by PB extrusion showed the following: fully unmethylated Igf2r-DMR copies (9/9) and partially methylated H19-DMR copies (4/11). These results reveal that rapid de novo methylating and demethylating activity are present when cells are subjected to partial activation. Thus, when the biological response of the oocyte is incomplete, that is to say, when the chromatin remains partially decondensed after suboptimal activation, both active demethylation and de novo methylation can be remarkably dynamic. While the molecular mechanism needs to be clarified, these results reveal that modulation of the process of egg activation might give new opportunities to better understand the epigenetic chromatin changes caused by fertilization.