Nuclear lamins are differentially expressed in retinal neurons of the adult rat retina.

Lamins are type V intermediate filament proteins that support nuclear membranes. They are divided into A-type lamins, which include lamin A and C, and B-type lamins, which include lamin B1 and B2. In the rat brain, lamin A and C are expressed in relatively equal amounts, while the expressions of lamin B1 and B2 vary depending on the cell type. Lamins play important roles in normal morphogenesis and function. In the nervous system, their abnormal expression causes several neurodegenerative diseases such as peripheral neuropathy, leukodystrophy and lissencephaly. The retina belongs to the central nervous system (CNS) and has widely been used as a source of CNS neurons. We investigated the expression patterns of lamin subtypes in the adult rat retina by immunohistochemistry and found that the staining patterns differed when compared with the brain. All retinal neurons expressed lamin B1 and B2 in relatively equal amounts. In addition, horizontal cells and a subpopulation of retinal ganglion cells expressed lamin A and C, while photoreceptor cells expressed neither lamin A nor C, and all other retinal neurons expressed lamin C only. This differential expression pattern of lamins in retinal neurons suggests that they may be involved in cellular differentiation and expression of cell-specific genes in individual retinal neurons.

Factors associated with the development of spontaneous intertwin membrane separation in dichorionic twin pregnancy.

OBJECTIVE: We examined factors associated with the development of spontaneous intertwin membrane separation in dichorionic twin pregnancy. METHODS: Medical charts of 618 dichorionic twin pregnancies without the history of amniocentesis managed after 22 weeks' gestation at Japanese Red Cross Katsushika Maternity Hospital between 2002 and 2017 were reviewed. RESULTS: Twenty-four cases (3.9%) were diagnosed with spontaneous intertwine membrane separation. The presence of different fetal sex and separated placentae were associated with the development of spontaneous intertwin membrane separation in dichorionic twin pregnancy (different fetal sex: crude odds ratio 2.44, 95% confidence interval, 1.1-5.5, p = .03; separated placentae: crude odds ratio 4.14, 95% confidence interval, 1.3-13, p = .01). CONCLUSION: The development of spontaneous intertwin membrane separation in dichorionic twin pregnancies seemed to be associated with dizygotic.

Unique Clinical and Histological Features of Placental Mesenchymal Dysplasia Complicated by Severe Preeclampsia in the Midtrimester.

Detailed clinical and pathological features of placental mesenchymal dysplasia (PMD) complicated by preeclampsia (PE) are unknown. A 39-year-old nulliparous woman was referred at 19 weeks gestation. Ultrasound examination identified a fetus with severe growth restriction (-2.8 SD) and a markedly thickened placenta with many cystic structures suggestive of PMD. At 21 weeks, the patient developed severe hypertension (180/95 mm Hg) with marked proteinuria and an elevated serum soluble fms-like tyrosine-kinase-1 (sFlt-1) level (47,000 pg/L). The pregnancy was terminated to protect maternal health. Placental weight was 450 g and no histopathological findings of either proliferation or dysplasia were observed in the trophoblast. Villous chromosome examination revealed a 46XX karyotype, consistent with the diagnosis of PMD. In addition to the pathological findings of vascular endothelial dysfunction characteristic of the placenta in PE cases, enhanced expression of sFlt-1 in the syncytiotrophoblast of the enlarged villi was confirmed by immunohistochemistry as a novel finding in this condition. Monitoring of the serum sFlt-1 value is suggested to be a useful predictor of the pathological change associated with extremely early severe PE in PMD cases.