PROBLEM : To determine if patients with unexplained recurrent miscarriage have a deficiency of decidual immunosuppressor cells that produce transforming growth factor β type 2, as has been found in mice with abortion due to rejection and/or trophoblast failure. METHODS : Decidual biopsy specimens were taken as near to the placental attachment site as possible under ultrasound guidance from first trimester legal termination (control) patients with recurrent miscarriage and non-viable pregnancy, and from patients with sporadic missed abortion. The tissue was tested for TGFβ-2+ suppressor cells by in situ hybridization, immunohistochemistry, and analysis of supernatants. RESULTS : TGFβ-2-related suppressor molecules similar but not identical to those identified in pregnant mice were released by decidual lymphoid cells. Fifty percent of 14 recurrent miscarriage patients showed a lack of suppressor cells and 59% were subnormal in comparison to 20 controls and 5 sporadic miscarriage patients, where 80–85% of the patients had detectable suppressor cells. CONCLUSIONS : Suppressor cell deficiency is compatible with a role for rejection and/or trophoblast failure in some patients with recurrent miscarriage. Presence of suppressor cells in most patients with missed abortion (4/5) is compatible with an alternative cause of fetal death, similar to findings reported in genetic fetal death mice. 相似文献
PURPOSE: This study examined the association between maternal smoking before and during the first trimester of pregnancy and spontaneous abortion.
METHODS: We have been conducting a hospital-based case-control study on risk factors for spontaneous abortion in the greater Milan area. We collected information from 782 cases of spontaneous abortions and 1543 controls (women who delivered at term healthy infants).
RESULTS: With respect to never smokers, the odds ratio (OR) were 0.7 (95%, confidence interval (CI), 0.5–1.0) for women who quit smoking and 1.3 (95% CI, 1.0–1.6) for those who continued during pregnancy. Women who smoked more than 10 cigarettes/day in the first trimester were at increased risk of miscarriage, with an OR of 1.4 (95% CI, 1.0–2.1). No relationship was evident between the number of cigarettes smoked before conception and the risk of abortion. Likewise, no association emerged between paternal smoking and miscarriage. Moreover, no significant interaction or modification effect was obtained when strata of age and other major characteristics were investigated.
CONCLUSIONS: The risk of abortion associated with cigarette smoking during the first trimester of pregnancy was measurable and noticeable in this population, and accounted for 9% (95% CI, 6–13%) of all cases. The increased risk of spontaneous abortion in women smoking during pregnancy is a further reason to encourage pregnant women to quit. 相似文献
The distribution of mannan binding protein (MBP) in blood donorsera was determined by enzyme-linked immunosorbent assay toestablish normal concentrations. Abnormally low MBP concentrationswere found in 16% (21 out of 135) of female partners and 14%(15 out of 108) of male partners of couples experiencing recurrentmiscarriage, compared with <5% of obstetrically normal controls(P < 0.005). This relationship was even stronger (9.5 versus1.0%) and more significant (P < 0.002) when only subjectspresumed to be homozygous for the mutant allele responsiblefor MBP deficiency were considered. By immunohistochemistry,MBP could be demonstrated in first trimester placenta. We suggestthat low concentrations of MBP within the feto-placental unitincrease susceptibility to fetal loss, possibly via an infection-inducedplacental cytokine imbalance. 相似文献
The inhibitory effect of a high external Ca2+ ([Ca2+]o) on spontaneous transmitter release in a high K+ solution (Gage and Quastel 1966; Birks et al. 1968) was studied at the frog neuromuscular junction, based on the hypothesis that an increased intracellular free Ca2+ ([Ca2+]i) in the nerve terminal plays a key role in the depression. Three procedures were employed to increase [Ca2+]i; increasing [Ca2+]o, application of caffeine and tetanic nerve stimulation. All of these procedures increased m.e.p.p. frequency in normal Ringer. However, as the basic m.e.p.p. frequency was increased by raising the external K+ concentration (7–15 mM), their facilitatory effects on m.e.p.p. frequency decreased, disappeared and eventually reversed to depressant actions. Since a rise in the external K+ concentration would increase the steady state level of [Ca2+]i, it is suggested that when the [Ca2+]i is preset at a high level, manipulations so as to further increase [Ca2+]i depress spontaneous release of transmitter. Possible mechanisms for this inhibition was discussed in relation to a question whether or not the rate of spontaneous transmitter release is a monotonic function of [Ca2+]i. 相似文献
Single myocytes were dissociated from the sino-atrial (SA) node of guinea-pig hearts. Only a quite small fraction of the
cell population showed spontaneous action potentials and these cells were characterized by the presence of the hyperpolarization-activated
cation current If , the delayed rectifier K+ current IK and the L-type Ca2+ current ICa,L as well as by the absence of both the transient outward current Ito and the inward rectifier K+ current IK,1. After blocking If and IK, depolarizing pulses from –80 mV revealed a large nicardipine-sensitive late current (NSLC). The NSLC was scarcely affected
by decreasing extracellular [Ca2+] ([Ca2+]o) from 1.8 to 0.1 mM, while it was decreased significantly by depleting [Na+]o, differently from ICa,L. NSLC was blocked by nicardipine and was increased by Bay K 8644. NSLC was increased by isoprenaline and the additional application
of acetylcholine reversed the increase of this current. We conclude that NSLC is largely composed of Ist described in the rabbit SA node pacemaker cells, and that Ist is unique for the pacemaker cells in mammalian SA node cells. Most of the quiescent cells showed neither If nor Ist.
Received: 22 July 1996 / Received after revision: 30 September 1996 / Accepted: 9 October 1996 相似文献
Oxytocin treatment in rats induces long-lasting antistress and growth promoting effects. This study investigated whether prolyl-leucyl-glycinamide (PLG) (the c-terminal tripeptide of oxytocin) or tocinoic acid (the ring structure of oxytocin) could induce some of these effects in male rats. For this purpose, PLG (2 or 10 mg/kg, s.c.) or tocinoic acid (1 mg/kg, s.c.) was administered to rats once a day for 3 or 5 days. Blood pressure, heart rate, spontaneous motor activity, nociceptive thresholds, and the survival of ischaemic musculocutaneous flaps were measured. In addition, endogenous oxytocin levels and plasma levels of some hormones known to be influenced by oxytocin were determined. PLG (2 mg/kg, s.c., but not 10 mg/kg, s.c.) decreased diastolic blood pressure (p<0.05) and locomotor activity (p<0.05). PLG (10 mg/kg, s.c.) decreased gastrin (p<0.05) and endogenous oxytocin levels in plasma (p<0.01). Tocinoic acid decreased locomotor activity (p<0.05), but did not affect any of the other parameters measured. In conclusion, this study showed that both PLG and tocinoic acid decrease locomotor activity. In addition, PLG also induced some other effects similar to those induced by oxytocin treatment but when administered in high doses it decreased oxytocin levels. 相似文献
A 51-year-old woman suffered rapidly irreversible cardiogenic shock with left hemiparesis. Transesophageal echocardiography, which represents an essential imaging tool in the emergency room, ruled out aortic dissection involving branch vessels but did not allow an in vivo diagnosis of spontaneous coronary dissection. The in vivo diagnosis of spontaneous coronary dissection is rather difficult because of the dramatic clinical presentation and selective coronary angiography requirement. 相似文献
PROBLEM: Infection has been proposed to initiate abortion, and the role of viruses in spontaneous resorption in mice has not been tested. METHOD: The anti-viral drug ribavirin (1-β-D-ribofuranosyl-1,2,4-triazole-3-carboxamide) was fed to CBA/J and C3H/HeJ female mice beginning on the morning after mating with DBA/2J males. RESULTS: Ribavirin treatment increased the rate of abortion (resorption) on day 13.5, and this was associated with retardation of the rate of embryo development and hypoplasia of the trophoblast. There was a reduction in trophoblast-dependent decidua-associated soluble suppressor activity, but there was no maternal mononuclear cell infiltrate of the type reported in association with resorption of semiallogeneic and xenogeneic mouse embryos. This may be due to an immunosuppressive effect of ribavirin. Ribavirin was able to potently suppress proliferation of mouse trophoblast and mastocytoma cell lines in vitro. CONCLUSIONS: There are several drug-induced murine abortion models that provide useful insights into potential mechanisms underlying spontaneous pregnancy failure, but in the ribavirin model, a direct impairment of trophoblast development appears to be responsible. 相似文献