Frequency Of Abortion Research Articles

Evidence that primary infection of Charollais sheep withToxoplasma gondiimay not prevent foetal infection and abortion in subsequent lambings

A study carried out on a sheep farm examined whether Toxoplasma gondii foetal infection and associated abortion occur in successive lambings. We identified 29 ewes that gave birth to lambs on at least 2 successive years over our study period, 2000-2003. Tissue samples from the progeny of these ewes were analysed by PCR to determine infection status with T. gondii. T. gondii-infected lambs were born in 31% of successive pregnancies. T. gondii-positive lambs were aborted in successive pregnancies in 21% of lambings during study period, 2000-2003. The frequency of successive abortions within this flock over the period 1992-2003 was 18%. If a lamb was congenitally infected there was a high risk (69%) that the successive lamb from that ewe would also be congenitally infected. Similarly, if a lamb was aborted there was a high risk (55%) of abortion in the next lamb produced. These data suggest that life-long immunity to T. gondii infections may not always be acquired following an initial infection and raises the question as to whether the mechanisms of T. gondii transmission prior to and during ovine pregnancies are fully understood.

History of spontaneous abortion increases the risk of oocyte donation pregnancy loss

A history of live birth may be an advantage to women who later need to undergo fertility treatments, although supporting data is lacking. We sought to see if pregnancy history, including live birth and frequency of spontaneous abortion (SAB) would relate to the incidence of pregnancy and miscarriage in women undergoing oocyte donation. Retrospective chart review of 606 donor oocyte transfers from January 2001– December 2004. All recipients were screened and treated for correctable anatomic causes of infertility prior to enrolling in donor egg (DE). Pre-embryo transfer data collected included the number of full term deliveries, pre-term deliveries, SAB, elective terminations and ectopic pregnancies. Post DE transfer data included delivery, no successful implantation, SAB, elective termination and ectopic pregnancy. Each cycle was assigned to three main groups; GxPx (x ≥ 1), GxP0 and G0P0. GxP0 was subdivided into those with history of (1) elective abortion only and (2) SAB and elective abortion or SAB only. Data was analyzed using chi square. 606 recipient cycles resulted in 369 pregnancies, 322 live births and 40 SAB. There was a significant difference between SAB rates in those with a history of successful pregnancy vs. those with history of SAB only (2.78% vs. 8.14% P<0.05). There was also a significant difference in the DE live birth rate of patients with previous history of live birth compared to those with history of spontaneous abortion only (61.81% vs. 44.19% P<0.01). There was no significant difference in the pregnancy or live birth rate in the GxPx group compared to the G0P0 group. Patients with history of elective abortion only had a pregnancy rate of 65.51% and a DE live birth rate of 54.10%, comparable to G0P0 group. Table 1Pregnancy outcomes after donor oocyte transferGestational HistoryGxPx N = 144GxP0 N = 172G0P0 N = 229Pregnancy rate (%)61.81 (89/144)44.19 (76/172)54.15 (124/229)Live birth rate (%)64.58 (93/144)54.10 (93/172)62.45 (143/229)Spontaneous abortion rate (%)2.78 (4/144)8.14 (14/172)6.55 (15/229) Open table in a new tab Women with a previous history of SAB have an increased risk of miscarriage and decreased live birth rate when compared to women who have had a live birth and who have never been pregnant. This model confirms that some women with anatomically normal uteri have intrinsic factors, uterine or systemic, that increase their risk for miscarriage. Oocyte donation provides an excellent model to study the etiology of pregnancy loss.

Characteristics of Induced Abortion in China in the 1990s

To understand the characteristics of induced abortion in China in the 1990s, and to find out the influential factors. The overall number of induced abortions, calculate cohort induced abortion frequency, explore the impact of a child's sex and the number of previous children on induced abortions were estimated by using the data from the “National Population and Reproductive Health Survey” conducted by the National Family Planning Commission in November 1997. Induced abortions in China had their own characteristics, which were far different from other countries. The main difference was led by the fact that the country was driven by an implemented family planning program and nationwide population policies. The key cause of induced abortions was due to an inconsistency with the requirements of the family planning policy. However, as a result of effective and preva-lent contraception, the rates of induced abortions were not quite high in the 1990s, when compared with other countries. Even though, in the early 1990s, the govern-ment had reinforced the family planning program through administration and legislation, unlike during the early 1980s when the one-child policy was implemented, the induced abortion rate and the number of induce abortions did not increase as the fertility rate substantially decreased. This finding implies that the fertility declines in the 1990s were not caused by the number of induced abortions. The transition of the fertility ideology of the people has played an important role in the fertility decline, as institutional reform and socioeconomic development are implemented.

Induced abortion frequency in Ankara, Turkey, before and after the legal regulation of induced abortion

Objective To determine the effects of the 1983 law that legalized induced abortion on the number and place of abortions, and on the use of family planning (FP) methods before and after abortion, and to determine the demographic characteristics and reproductive health features according to the order of abortion.Method This study included 2455 married, widowed or divorced women presenting at Mother and Child Health-Family Planning Centres in Ankara. A questionnaire was used for data collection.Result Nearly three out of 10 (28.7%) of the women had undergone at least one induced abortion. In the age groups 45–54 and 55–64, 49 and 37.3%, respectively, had had one or more terminations of pregnancy (TOPs). The induced abortion rate increased following the enacting of the law. In the 15–24 and in the 55–64 age group, 55.6 and 89%, respectively, of the women had been aborted by a private physician. Before the index pregnancy, 63.1% were not using contraception compared with 37.3% thereafter. The rate of use of FP increased after the law was passed.Conclusion Although the most common reason for having an abortion was unwanted pregnancy in all age groups and nearly 60.0% of the women aged less than 55 reported that they were not using any FP method at the time of the TOP, the proportion of women having undergone at least one of these procedures increased after the law was passed, indicating that abortion is used as a FP method.

97 CLONED CALF PRODUCTION BY AGGREGATION OF SOMATIC CELL NUCLEAR-TRANSFERRED EMBRYOS

A low pregnancy rate and high frequency of abortion are observed in bovine somatic cell cloning. It is suggested that one of the factors is the low cell number of nuclear-transferred (NT) embryos at the blastocyst stage compared with that of in vivo-derived embryos. We reported that aggregation of bovine NT embryos can develop to blastocysts with cell numbers that are equivalent to in vivo-derived embryos (Akagi et al. 2005 Reprod. Fertil. Dev. 17, 162 abst). In this study, we examined the in vivo development of aggregates of NT embryos after embryo transfer (ET). Following culture in serum-starved medium for 5 to 7 days, fibroblast cells were used as donor cells for NT. NT was performed as previously described (Akagi et al. 2003 Mol. Reprod. Dev. 66, 264–272). Eight-cell stage embryos on Day 2 or 16- to 32-cell stage embryos on Day 4 were used for embryo aggregation after removal of the zona pellucida. Three NT embryos were placed into the depression in a drop of TCM-199 with 50 µg mL−1 phytohemagglutinin for 20 min, and NT aggregates were then moved into the depression in a drop of IVD-101 (Akagi et al. 2005). On Day 7 after NT, ET was performed nonsurgically. Results are summarized in Table 1. Pregnancy rates obtained with the aggregated NT embryos tended to be high compared with the single NT embryos. All pregnant cows in the single NT embryos and 6 of 8 pregnant cows in the aggregated NT embryos were aborted within 90 days. One cow carrying an aggregate of 3 Day 2 NT embryos went to term, and one carrying an aggregate of 3 Day 4 NT embryos is still pregnant at more than 7 months. These results demonstrate that aggregates of 3 NT embryos can develop to term in cattle. Table 1.In vivo development of aggregated NT embryos

The Effect of Inbreeding on Mortality and Morbidity among Telugu-speaking Populations of Kharagpur, West Bengal, India

Increased mortality and morbidity including congenital malformations among the offspring of consanguineous marriages have been widely reported in human populations from different parts of the world. However, there are few studies on the effect of the intensity of inbreeding and different degrees of inbreeding on mortality and morbidity. The present study is an attempt to examine the effects of inbreeding on mortality and morbidity including congenital disorders in different levels of inbreeding among Telugu-speaking populations of Kharagpur, West Bengal, India, based on data collected through extensive pedigrees. The study reveals that the frequency of spontaneous abortions and stillbirths is higher in the offspring of consanguineous marriages than in that of non-consanguineous marriages. A similar effect is also observed in the infant mortality rate, which is known to have a genetic component, but is not seen in the mortality rate of children and juveniles. The rate of morbidity is consistently higher in the offspring of consanguineous marriages with a sex bias in favour of inbred females. The increased morbidity rates in inbred individuals tend to be inversely correlated with the increase in average autosomal inbreeding coefficient. This appears to strengthen Sanghvi’s hypothesis of a decline in the frequency of deleterious genes with intensification of inbreeding through generations. The present study also confirms an increase in genetic disorders with an increase in inbreeding in almost all populations.

A molecular approach to the identification of cytotoxic T-lymphocyte epitopes within equine herpesvirus 1

Equine herpesvirus 1 (EHV-1) causes respiratory and neurological disease and abortion in horses. Animals with high frequencies of cytotoxic T lymphocytes (CTL) show reduced severity of respiratory disease and frequency of abortion, probably by CTL-mediated control of cell-associated viraemia. This study aimed to identify CTL epitopes restricted by selected major histocompatibility complex (MHC) class I alleles expressed in the equine leukocyte antigen (ELA) A3 haplotype. Effector CTL were induced from EHV-1-primed ponies and thoroughbreds with characterized MHC class I haplotypes and screened against P815 target cells transfected with selected EHV-1 genes and MHC class I genes. Targets that expressed EHV-1 gene 64 and the MHC B2 gene were lysed by effector CTL in a genetically restricted manner. There was no T-cell recognition of targets expressing either the MHC B2 gene and EHV-1 genes 2, 12, 14, 16, 35, 63 or 69, or the MHC C1 gene and EHV-1 genes 12, 14, 16 or 64. A vaccinia virus vector encoding gene 64 (NYVAC-64) was also investigated. Using lymphocytes from ELA-A3 horses, the recombinant NYVAC-64 virus induced effector CTL that lysed EHV-1-infected target cells; the recombinant virus also supplied a functional peptide that was expressed by target cells and recognized in an MHC-restricted fashion by CTL induced with EHV-1. This construct may therefore be used to determine the antigenicity of EHV-1 gene 64 for other MHC haplotypes. These techniques are broadly applicable to the identification of additional CTL target proteins and their presenting MHC alleles, not only for EHV-1, but for other equine viruses.

Spontaneous and therapeutic abortions and the risk of breast cancer among BRCAmutation carriers

IntroductionBRCA1 and BRCA2 mutation carriers are at increased risk for developing both breast and ovarian cancer. It has been suggested that carriers of BRCA1/2 mutations may also be at increased risk of having recurrent (three or more) miscarriages. Several reproductive factors have been shown to influence the risk of breast cancer in mutation carriers, but the effects of spontaneous and therapeutic abortions on the risk of hereditary breast cancer risk have not been well studied to date.MethodsIn a matched case-control study, the frequencies of spontaneous abortions were compared among 1,878 BRCA1 mutation carriers, 950 BRCA2 mutation carriers and 657 related non-carrier controls. The rates of spontaneous and therapeutic abortions were compared for carriers with and without breast cancer.ResultsThere was no difference in the rate of spontaneous abortions between carriers of BRCA1 or BRCA2 mutations and non-carriers. The number of spontaneous abortions was not associated with breast cancer risk among BRCA1 or BRCA2 mutation carriers. However, BRCA2 carriers who had two or more therapeutic abortions faced a 64% decrease in the risk of breast cancer (odds ratio = 0.36; 95% confidence interval 0.16–0.83; p = 0.02).ConclusionCarrying a BRCA1 or BRCA2 mutation is not a risk factor for spontaneous abortions and spontaneous abortions do not appear to influence the risk of breast cancer in carriers of BRCA1 or BRCA2 mutations. However, having two or more therapeutic abortions may be associated with a lowered risk of breast cancer among BRCA2 carriers.

Nerve Growth Factor Translates Stress Response and Subsequent Murine Abortion via Adhesion Molecule-Dependent Pathways1

Spontaneous abortion is a frequent threat affecting 10%-25% of human pregnancies. Psychosocial stress has been suggested to be attributable for pregnancy losses by challenging the equilibrium of systems mandatory for pregnancy maintenance, including the nervous, endocrine, and immune system. Strong evidence indicates that stress-triggered abortion is mediated by adhesion molecules, i.e., intercellular adhesion molecule 1 (ICAM1) and leukocyte function associated molecule 1, now being referred to as integrin alpha L (ITGAL), which facilitate recruitment of inflammatory cells to the feto-maternal interface. The neurotrophin beta-nerve growth factor (NGFB), which has been shown to be upregulated in response to stress in multiple experimental settings including in the uterine lining (decidua) during pregnancy, increases ICAM1 expression on endothelial cells. Here, we investigated whether and how NGFB neutralization has a preventive effect on stress-triggered abortion in the murine CBA/J x DBA/2J model. We provide experimental evidence that stress exposure upregulates the frequency of abortion and the expression of uterine NGFB. Further, adhesion molecules ICAM1 and selectin platelet (SELP, formerly P-Selectin) and their ligands ITGAL and SELP ligand (SELPL, formerly P selectin glycoprotein ligand 1) respectively increase in murine deciduas in response to stress. Subsequently, decidual cytokines are biased toward a proinflammatory and abortogenic cytokine profile. Additionally, a decrease of pregnancy protective CD8alpha(+) decidual cells is present. Strikingly, all such uterine stress responses are abrogated by NGFB neutralization. Hence, NGFB acts as a proximal mediator in the hierarchical network of immune rejection by mediating an abortogenic environment comprised of classical signs of neurogenic inflammation.

Prävalenz kindlicher Fehlbildungen bei Frauen mit einem präexistenten Diabetes mellitus in Abhängigkeit von der Stoffwechseleinstellung

Fragestellung: Die Studie sollte klären, ob in Thüringen bei Frauen mit Diabetes mellitus (DM) die Forderung der St.-Vincent-Deklaration von 1990 nach einem mit nicht diabetischen Schwangeren vergleichbaren Geburtsergebnis umgesetzt werden konnte. Patienten und Methodik: Bei 77 Schwangerschaften bei DM Typ 1 und 8 bei DM Typ 2 wurden die mütterliche Stoffwechseleinstellung (HbA1c präkonzeptionell und bei Bekanntwerden der Schwangerschaft, Blutglukosemittelwerte in jedem Schwangerschaftsmonat) und die Häufigkeit von Aborten, Totgeburten und kongenitalen Fehlbildungen analysiert. Ergebnisse: Nur 43,5 % der Frauen konsultierten präkonzeptionell (1 - 6 Monate) einen Diabetologen. Die erste diabetologische Konsultation während der Schwangerschaft erfolgte in der 9. SSW (3. - 33. SSW). Die Prävalenz der Totgeburten unterschied sich nicht von stoffwechselgesunden Frauen (1,2 % vs. Perinatalerhebung Universität Jena 0,7 %; n. s.). 4,7 % der Schwangerschaften endeten mit einem Abort; der HbA1c (Normbereich: 4,58 - 5,90 %) lag während der Organogenese signifikant höher (HbA1c bei Abort: 10,5 ± 3,6 vs. kein Abort: 7,2 ± 1,5 %; p < 0,001), keine Frau mit Abort konsultierte präkonzeptionell einen Diabetologen. Die Prävalenz von kongenitalen Fehlbildungen lag bei Frauen mit DM im Vgl. zu Stoffwechselgesunden signifikant höher (17,6 vs. 3,1 %; p < 0,001). Frauen, deren Kind eine Fehlbildung aufwies, lagen präkonzeptionell mit dem HbA1c signifikant höher als Frauen mit gesundem Kind (8,7 ± 1,7 vs. 7,5 ± 1,7 %; p < 0,03), zeigten signifikant höhere mittlere Blutglukosewerte (5. - 8. SSW: 8,0 ± 1,7 vs. 6,4 ± 1,4 mmol/l; p < 0,01. 9. - 12. SSW: 5,8 ± 1,0 vs. 7,1 ± 1,8 mmol/l; p < 0,01) und hatten sich nach Bekanntwerden der Schwangerschaft später in diabetologische Behandlung begeben (17.± 9 SSW vs. 10.± 6 SSW; p < 0,001). Schlussfolgerung: Die Ursache der Aborte und der hohen kongenitalen Fehlbildungsrate bei Frauen mit DM liegt in einer Hyperglykämie zum Zeitpunkt der Konzeption und im Verlauf des 1. Trimenons sowie einer fehlenden diabetologischen Mitbetreuung in dieser Zeit. Als Empfehlungen für Stoffwechselzielwerte lassen sich für die Zeit der Organogenese aus der Untersuchung folgende Zielbereiche ableiten: HbA1c < 6,3 %, Blutglukosemittelwert < 6,4 mmol/l.

Aspectos epidemiológicos, clínicos e parasitológicos da doença de Chagas em Mato Grosso do Sul

With the objective of evaluating epidemiologic, clinical and parasitologic aspects of chronic Chagas' disease in patients from the University Hospital of the Federal University of Mato Grosso do Sul, a cross-sectional study was performed with groups of 120 chagasic and non-chagasic patients aged from 16 to 82 years. Epidemiologic aspects were evaluated by means of a questionnaire, cardiopathy by clinical examination, conventional electrocardiogram, radiology and Doppler echocardiograms (only in chagasic patients) and the presence of Trypanosoma cruzi in the blood stream by way of xenodiagnosis and polymerase chain reaction test. The results obtained indicated that the chagasic patients are predominantly alloctones with low-grade schooling, and were exposed to triatomines. The frequency of spontaneous abortion was higher in chagasic women. Chronic chagasic cardiopathy, estimated to occur in 20.2% of the patients, showed 7.5% cardiomegaly, 6.2% aneurysm of the left ventricle, and with a predominance of dyspnea, palpitations and arterial hypertension. Xenodiagnosis was positive for 26.1% of the chagasics and the PCR was positive for 53.7%, and was significantly higher in males and alloctones. An analysis of the results shows that Chagas' disease, in the group studied, presented clinical and parasitologic characteristics demonstrating significant regional differences.

The biological aspects of risks of infertility due to age: the female side

When women reach their forties, and despite strong inter-individual variations, their fecundity, either spontaneous or assisted, is impaired then falls down from the age of 45 onwards. In humans the size of the ovarian reserve is definitely fixed at birth and decreases drastically with age. Follicles leave the stock of resting follicles in a continuous stream, either disappearing by apoptosis or entering the growth phase. From the age of about 38 years onwards, the rate of follicular depletion accelerates leading to a decreasing number of selectable follicles. As these follicles produce inhibin B, its circulating levels drop, resulting in an increase in circulating FSH concentration. The higher rate of growth of large follicles in women over the age of 40 than in younger women, likely due to high FSH levels, and/or an early selection of the preovulatory follicle seem responsible for the shortening of the follicular phase in women in their late thirties and early forties. An impaired endometrial receptivity and/or a decrease in oocyte quality, or both may be responsible for the increase of the frequency of spontaneous abortion when women reach their forties. In conclusion, it can be predicted that, although apparently inescapable, the fertility impairment due to ageing could be, at least partly, counteracted by the use of molecules preventing attrition of the ovarian reserve.

Significant familial differences in the frequency of abortion and Toxoplasma gondii infection within a flock of Charollais sheep

A study was carried out to investigate the frequencies of abortion and congenital Toxoplasma gondii infection within 27 families (765 individuals) of a pedigree Charollais sheep flock maintained on a working farm in Worcestershire, UK, since 1992. Pedigree lambing records were analysed to establish the frequency of abortion for each family. The frequency of congenital infection was determined for each family by PCR analysis of tissue samples taken from newborn lambs. A total of 155 lambs were tested for congenital T. gondii infection, which were all born during the study period 2000-2003. Significant differences in the frequency of abortion between sheep families within this flock were observed with frequencies ranging between 0% and 48% (P < 0.01). Significantly different infection frequencies with T. gondii were also observed for different families and ranged between 0% and 100% (P<0.01). Although the actual cause of each abortion was not verified, a highly significant positive correlation was found to exist between the frequency of abortion and the frequency of T. gondii infection in the same families (P<0.01). The data presented here raise further questions regarding the significance of congenital transmission of T. gondii within sheep populations, the possible successive vertical transmission of T. gondii within families of sheep, and the potential role of inherited genetic susceptibility to abortion with respect to T. gondii infection. This work invites further study into the epidemiology of ovine toxoplasmosis and may have implications for sheep husbandry methods in the future.

Ultrasonographic signs of poor pregnancy outcome

The advantages of high resolution ultrasonography are that it allows more precise diagnosis of any abnormalities in early pregnancy. The frequency of spontaneous interruptions of the development of the reproductive process is very high, especially during the initial stages. It is calculated that, considering the shortcoming of the fecundation, of each 100 potential pregnancies, only 31 will reach full term with a live fetus. The frequency of abortion, considering this as the spontaneous interruption of a pregnancy before the fetus has reached viability, depends therefore on the approach that we use to define that pregnancy exists.

Living in high natural background radiation areas in Ramsar, Iran. Is it dangerous for health?

The main goal of the present study is to examine the health effects of high natural background radiation among the residents of Ramsar, one of the inhabited areas with highest natural background radiation. This report summarizes the data obtained from 402 residents of high background radiation area and 374 residents from an adjacent normal radiation area. Overall data showed no significant differences in the frequencies of any mental and physical disabilities as well as malignancies between residents of normal and high background radiation areas. Results also showed no significant increase in the frequency of death, abortion and mental depression among inhabitants in high background radiation area. We plan to extend our work, using more clinical and paraclinical tests on these populations in the next phase of the study.

Praziquantel for the treatment of schistosomiasis mansoni during pregnancy

In a prospective study carried out in New Halfa Teaching Hospital, in eastern Sudan, between June 2001 and April 2003, 25 pregnant Sudanese women with schistosomiasis mansoni were each treated with a single oral dose of praziquantel (PZQ), at 40 mg/kg. The drug was given to six (24%), 12 (48%) and seven (28%) of the women during the first, second and third trimesters of their pregnancies, respectively. The patients were followed-up until delivery and their babies were followed-up until they were 1 year old. Although one patient, who received PZQ after 10 weeks of gestation, aborted (3 weeks post-treatment), this frequency of abortion is similar to that seen in the local community. None of the treated women died, and there were no stillbirths or congenital abnormalities in the newborn babies. Although this is a small trial, it appears that PZQ is a safe drug to use against schistosomiasis mansoni, even during the first trimester of pregnancy.

Abort- und Frühgeburtenrate nach akuter Mumpsinfektionin der Schwangerschaft

Fragestellung: Aufgrund der hohen Durchseuchungsraten treten akute Mumpsinfektionen in der Schwangerschaft nur selten auf. Daher ist die Datenlage zu möglichen negativen Auswirkungen der Mumpsinfektion auf den Schwangerschaftsausgang begrenzt. Patientinnen und Methoden: In unserem Labor wurde zwischen Januar 1985 und Dezember 2002 bei 79 Schwangeren die klinische Diagnose einer Mumpsinfektion serologisch bestätigt. Die uns vorliegenden Daten zum Schwangerschaftsausgang wurden durch die behandelnden Gynäkologen oder Geburtshelfer im Rahmen der Diagnostik und Beratung übermittelt. Nabelschnurblutproben von 26 der 57 lebend geborenen Kinder wurden mittels Enzymimmunoassay auf das Vorliegen mumpsspezifischer IgM- und IgG-Antikörper untersucht. Ergebnisse: Zweiundsechzig Patientinnen wurden prospektiv bis zum Ende der Schwangerschaft verfolgt. In 2 Fällen erfolgte eine Interruptio aus sozialer Indikation. Die fetale Verlustrate betrug bezogen auf das Gesamtkollektiv 6,6% (4/60). Nur 2 Aborte traten im ersten Trimenon auf. Alle Aborte wurden jedoch bei Patientinnen beobachtet, die im ersten Trimenon an Mumps erkrankten. Ein konstantes Zeitintervall zwischen Mumpsinfektion und Schwangerschaftsverlust war nicht zu verzeichnen. Das mediane Gestationsalter lag zum Zeitpunkt der Entbindung bei 40 Schwangerschaftswochen (SSW). Zwei der 57 lebend geborenen Kinder (3,5%) wurden vor der vollendeten 37. SSW entbunden. In keiner der 26 untersuchten Nabelschnurblutproben waren mumpsspezifische IgM-Antikörper nachweisbar. Schlussfolgerungen: Der fehlende Nachweis mumpsspezifischer IgM-Antikörper im Nabelschnurblut spricht bei den untersuchten Fällen gegen eine pränatale Mumpsinfektion. Die beobachtete Frühgeburten- und Abortrate erscheint nach Mumpsinfektion in der Schwangerschaft im Vergleich zum Normalkollektiv nicht erhöht.

Is amniotic fluid interleukin-6 determination of value before the placement of a “rescue cerclage”?

Is amniotic fluid interleukin-6 determination of value before the placement of a “rescue cerclage”?

Chromosome Instabilities and Programmed Cell Death in Tapetal Cells of Maize With B Chromosomes and Effects on Pollen Viability

Abstract B chromosomes (B’s), knobbed chromosomes, and chromosome 6 (NOR) of maize undergo nondisjunction and micronucleus formation in binucleate tapetal cells. These chromosome instabilities are regular events in the program of tapetal cell death, but the B’s strongly increase A chromosome instability. We studied 1B and 0B plants belonging to selected lines for high or low B transmission rate and their F1 hybrids. These lines are characterized by meiotic conservation or loss of B chromosomes, respectively. The female B transmission (fBtl) allele(s) for low B transmission is dominant, inducing micronucleus formation and B nondisjunction. We hypothesize that the fBtl allele(s) induces knob instability. This instability would be sufficient to produce B loss in both meiocytes and binucleate tapetal cells. B instability could, in turn, produce instabilities in all chromosomes of maize complement. To establish whether the chromosomal instabilities are related to the tapetal programmed cell death (PCD) process, we applied the TUNEL technique. PCD, estimated as the frequency of binucleate tapetal cells with TUNEL label, was significantly correlated with the formation of micronuclei and the frequency of pollen abortion. It can be concluded that the observed chromosome instabilities are important to the PCD process and to the development of microspores to form viable pollen grains.

Chromosome instabilities and programmed cell death in tapetal cells of maize with B chromosomes and effects on pollen viability.

B chromosomes (B's), knobbed chromosomes, and chromosome 6 (NOR) of maize undergo nondisjunction and micronucleus formation in binucleate tapetal cells. These chromosome instabilities are regular events in the program of tapetal cell death, but the B's strongly increase A chromosome instability. We studied 1B and 0B plants belonging to selected lines for high or low B transmission rate and their F1 hybrids. These lines are characterized by meiotic conservation or loss of B chromosomes, respectively. The female B transmission (fBtl) allele(s) for low B transmission is dominant, inducing micronucleus formation and B nondisjunction. We hypothesize that the fBtl allele(s) induces knob instability. This instability would be sufficient to produce B loss in both meiocytes and binucleate tapetal cells. B instability could, in turn, produce instabilities in all chromosomes of maize complement. To establish whether the chromosomal instabilities are related to the tapetal programmed cell death (PCD) process, we applied the TUNEL technique. PCD, estimated as the frequency of binucleate tapetal cells with TUNEL label, was significantly correlated with the formation of micronuclei and the frequency of pollen abortion. It can be concluded that the observed chromosome instabilities are important to the PCD process and to the development of microspores to form viable pollen grains.