The effects of ionizing radiation, microwaves, and ultrasound on the developing embryo: clinical interpretations and applications of the data

The clinical characteristics and treatment of cerebral AVM in pregnancy

Cerebral arteriovenous malformation (AVM) in pregnancy is a complex situation and there is no agreement on its hemorrhage risk and treatment. Although studies on bleeding risk of cerebral AVMs in pregnancy are very few and there are different results between them, pregnancy will increase the hemorrhagic risk of AVM, and ruptured cerebral AVM in pregnancy should be treated actively. After intracranial hemorrhage, cerebral angiography should be performed for pregnant women shielded correctly. Cerebral angiography could clearly demonstrate the characteristics of cerebral AVM. The results from the literature show that the radiation dose of endovascular and stereotactic radiotherapy for cerebral AVM in pregnancy is below the safety value and is safe. Unruptured AVM in pregnancy, if there is no bleeding factor, such as no coexisting aneurysm, smooth venous drainage, no venous ectasia, or high risk of treatment, should be observed conservatively.

The clinical characteristics and treatment of cerebral AVM in pregnancy

Cerebral arteriovenous malformation (AVM) in pregnancy is a complex situation and there is no agreement on its hemorrhage risk and treatment. Although studies on bleeding risk of cerebral AVMs in pregnancy are very few, and they provide different results, pregnancy will increase the hemorrhagic risk of AVM and ruptured cerebral AVM in pregnancy should be actively treated. After intracranial hemorrhage, cerebral angiography should be performed for pregnant women shielded correctly. Cerebral angiography could clearly demonstrate the characteristics of cerebral AVM. Results from the literature show that the radiation dose of endovascular and stereotactic radiotherapy for cerebral AVM in pregnancy was below the safety value and was safe. For an unruptured AVM in pregnancy, if there are no bleeding factors, e.g. no coexisting aneurysm, smooth venous drainage, no venous ectasia, or high risk of treatment, then it should be observed conservatively.

Lack of adaptive response of gamma radiation for protection against neutron-induced teratogenesis

BACKGROUND

Although there are some reports on neutron teratology, there is little information on the adaptive response of gamma radiation for protection against neutron-induced teratogenesis. This study examined whether or not a low dose of gamma radiation can induce an adaptive response in mouse fetuses exposed to a subsequent dose of neutrons in vivo.

METHODS

Pregnant ICR mice were exposed to a priming dose of 0.3 Gy (0.9 Gy/min) of gamma rays on day 10.5 of gestation and challenged with 0.8 Gy (0.94 Gy/minute) of neutrons 24 h later. The mice were sacrificed on day 18.5 of gestation. The fetuses were examined for mortality, growth retardation, and other morphologic abnormalities.

RESULTS

The tail length in the 0.3 Gy of gamma rays + 0.8 Gy of neutrons group was significantly shorter than in the 0.8 Gy of neutrons group. Although there was no significant difference compared with the 0.8 Gy of neutrons group, the number of live fetuses in the 0.3 Gy of gamma rays +0.8 Gy of neutrons group was lower. There was no evidence of primed exposure-related reductions in the malformed fetuses. Although there was no significant difference compared with the unprimed group, the number of malformed offspring in the primed group was higher. Furthermore, the incidence of kinked tail and adactyly was significantly higher in the primed mice than in the unprimed mice.

CONCLUSIONS

Overall, this study shows that exposure to 0.3 Gy of gamma rays failed to induce an adaptive response of fetogenesis to a neutron challenge dose.

Breast cancer and pregnancy

Pregnancy-associated breast cancer has an overall worse prognosis than nonpregnancy-associated breast cancers because a large proportion present with more advanced disease. Stage for stage, however, the prognosis is similar. The various modalities used for screening, diagnosis, and staging of breast cancer are not always applicable during pregnancy. Often, a delay in diagnosis may contribute to a more advanced stage at presentation. The management of pregnant women with breast cancer is also different because it involves assessing the possible risks to the fetus versus the maternal benefits.

Management of choledocholithiasis during pregnancy: a new protocol in the laparoscopic era

The management of symptomatic cholelithiasis during pregnancy remains a serious and difficult problem. This condition may be further complicated by the presence of common bile duct stones (CBDS). Two cases of CBDS in pregnancy are presented. During the period from August 1990 to June 1994, 1127 consecutive patients underwent LC by a single surgical team. Two (0.2%) of these patients were pregnant and both were found to have choledocholithiasis. One patient's stones were lavaged into the duodenum via the cystic duct and the other patient had transcystic choledochoscopy and transcystic duct tube drainage. The patients were discharged from the hospital on postoperative days 4 and 6, respectively. There were no complications and both successfully carried their pregnancies to term. Laparoscopic cholecystectomy (LC) with transcystic common bile duct exploration (TCDE) was advantageous in both patients. Neither patient required an abdominal incision or choledochotomy. Laparoscopic TCDE with or without cystic tube drainage is a viable option in the management of CBDS in the pregnant patient.

Interaction between radiation and cadmium or mercury in mouse embryos during organogenesis

The response of mouse embryos to different concentrations of cadmium or mercury with or without low LET radiation was measured in terms of gross morphological anomalies and cellular changes. Single doses of the heavy metals (2 mg/kg body weight) were injected i.p. on day 8 of gestation 30 min before whole-body irradiation. Combined exposures to CdCl2 and X-rays led to a significant reduction in the rate of exencephaly compared with the high frequency after cadmium alone. The hypothesis that metallothionein, a sulphur-rich and metal-binding protein, may be responsible for the antagonism observed could not be confirmed. Mercuric chloride alone induced a low rate of exencephaly and the data on combined treatment suggest additivity with 0.5 and 1.0 Gy X-rays. Regarding cellular criteria, cell death in the eye anlage on day 9 of gestation was significantly suppressed after 0.5 Gy and especially after CdCl2 plus 0.5 Gy compared to cadmium alone. It is assumed that the reduction of cell lethality is correlated with the low occurrence of exencephaly. Concerning the proliferation of neuroblasts, cadmium stimulated the mitotic activity whereas X-rays depressed the proliferation capacity. After the combined treatment a distinct antimitotic effect was established.