Cell death in retinoblastoma: electron microscopic, immunohistochemical, and DNA fragmentation studies

Apparent cell loss by apoptosis occurs in carcinomatous tissue. To investigate cell death in retinoblastoma (Rb), ultrastructural examination, ApopTag staining, electrophoresis to detect apoptotic DNA fragmentation, and flow cytometric studies were performed. Immunostaining for the oncogenic products bcl-2 and p53 was also carried out. Relationships between the proliferation fraction (PF), apoptotic index (AI), and the distribution of bcl-2 and p53 were investigated according to the degree of histologic differentiation of Rb. Ultrastructurally, two patterns of cell death were seen. Necrotic cells exhibited vacuolation of cytoplasmic organelles with a marked lytic change in the karyoplasm and cytoplasm. In contrast, apoptotic cells were characterized by crescentic margination of chromatin, condensation of karyoplasm and cytoplasm, and fragmentation of the nucleus. Differentiated Rb had a low AI value (< 1%), whereas undifferentiated Rb had a high AI value (> 8%). The PF of undifferentiated RB (31%) was significantly higher than that of differentiated RB (14%). Analysis of DNA fragmentation using 3'-end labeling with terminal transferase indicated that undifferentiated Rb has increased DNA cleavage. The distribution of apoptotic bodies within Rb was inversely correlated with the expression of bcl-2. A majority of tumor cells of differentiated Rb were negative for p53, whereas 20-40% of tumor cells of undifferentiated Rb showed a positive reaction for p53. These findings suggest that the degree of susceptibility to apoptosis is closely related to PF, is inversely related to the degree of differentiation of Rb, and is protected by oncogene bcl-2.     

Family Belongingness Attenuates Entrapment and Buffers Its Association with Suicidal Ideation in a Sample of Dutch Sexual Minority Emerging Adults

Sexual minority emerging adults are more likely to engage in suicidal ideation than their heterosexual counterparts. Experiences of homophobic violence are associated with suicidal ideation. Yet, the specific mechanisms linking homophobic violence to suicidal ideation remain unclear. Entrapment and social belongingness were tested to determine their relevance for understanding the link between homophobic violence and suicidal ideation. A sample of sexual minority Dutch emerging adults (N?=?675; ages 18–29, M?=?21.93 years, SD?=?3.20) were recruited through online platforms and flyers. Homophobic violence was expected to be positively associated with suicidal ideation and entrapment. The association between homophobic violence and suicidal ideation was expected to be indirectly linked through entrapment. We explored whether various sources of social belongingness moderated the path between entrapment and suicidal ideation and whether those sources of social belongingness moderated the indirect effect of homophobic violence on suicidal ideation through entrapment. Results showed that homophobic violence and entrapment were positively associated with suicidal ideation and that family belongingness was negatively associated with suicidal ideation. Homophobic violence and suicidal ideation were not indirectly linked through entrapment. The interaction effect between entrapment and family belongingness was significant, suggesting that, on average, the effect of entrapment on suicidal ideation decreased when family belongingness was high. These results suggest that family belongingness may reduce the association between entrapment and suicidal ideation while adjusting for homophonic violence. Reducing entrapment and improving family belongingness may be useful targets for programs aimed at preventing suicidal ideation among sexual minority emerging adults.

     

合心爽,硝酸甘油治疗不稳定型心绞痛对比研究

目的 比较用硝酸甘油和合心爽治疗９８例不稳定型心绞痛的疗效。方法 随机分组,分别静滴合心爽和硝酸甘油,以难治性心绞痛、心肌梗塞或缺血性猝死为治疗终点。结果 发展为难治性心绞痛或心肌梗塞病例在合心爽组为５人,硝酸甘油组为１１人,发生心肌梗塞者合心爽组３人,硝酸甘油８人,缺血性猝死者合合爽组无,硝酸甘油组１人。结论 静脉用合心爽治疗不稳定型心绞痛疗效优于硝酸甘油（Ｐ〈０．００１）。     

Intranuclear inclusions in subtypes of striatal neurons in Huntington's disease transgenic mice

R6/2 transgenic mice express exon 1 of an abnormal human Huntington's disease (HD) gene and develop a neurological phenotype similar to HD. These mice develop ubiquitinated neuronal intranuclear inclusions (NII) which might play a central role in the pathophysiology of HD. We studied the distribution of NII in subpopulations of striatal neurons in 12-week-old R6/2 transgenic mice using fluorescent double label immunohistochemistry. We observed that most of the Calbindin-D28K positive projection neurons (89%) and the Parvalbumin positive interneurons (86%) showed ubiquitinated NII. In interneurons, however, which contain either choline acetyltransferase, neuronal nitric oxide synthase, or Calretinin, the frequency of NII was much lower (22%, 8%, 9%, respectively). Our data suggest that subpopulations of striatal neurons differ remarkably in their capability of forming ubiquitinated NII. Interneurons which are known to resist neurodegeneration in HD show less NII.     

Reactive astrocytes express p53 in the spinal cord of transgenic mice expressing a human Cu/Zn SOD mutation

In a previous study, we reported increased NOS expression in the astrocytes in the spinal cord of SOD mutant transgenic mice that are used as ALS animal model. Recently, Messmer and Brune suggested that nitric oxide-induced apoptosis is intimately related with p53-dependent signaling pathway, and de la Monte et al. reported increased p53-immunoreactivity in the spinal cord of ALS patients. In the present study, we performed immunocytochemical studies to investigate the changes of p53-immunoreactivity in the brains of the mutant transgenic mice expressing a human Cu/Zn SOD mutation. Immunocytochemistry showed intensely stained p53-IR glial cells with the appearance of astrocytes in all levels of the spinal cord of the mutant transgenic mice, but no p53-IR glial cells were observed in the spinal cord of the control mice. P53-IR astrocytes were also detected in the brain stem of the mutant transgenic mice. In the medulla, they were observed in the medullary reticular formation, hypoglossal nucleus, vestibular nucleus, dorsal motor nucleus of the vagus and nucleus ambiguus. In the pons, their presences were noted in the pontine reticular formation, and trigeminal and facial nuclei. In the midbrain, astrocytes were detected in the mesencephalic reticular formation, red nucleus and periaqueductal gray matter. In the cerebellum, intensely stained p53-IR astrocytes were detected in the intracerebellar nuclei. In contrast to the mutant transgenic mice, no p53-IR astrocytes were detected in the brain stem and spinal cord of the control mice. Further multidisciplinary investigations involving p53-mediated cellular damage and pathogenesis of ALS are needed to clarify the importance of these results.     

c-Fos basal immunoreactivity decreases in rat spinal cord during normal ageing

The pattern of distribution in rat spinal cord and changing pattern during normal ageing of c-Fos expression were investigated by immunohistochemical staining in male Sprague-Dawley rats at the age of 1 week, 5 months and 2 years. c-Fos immunoreactivity was observed diffusely in gray matters in neonatal rats, preferentially located in deep dorsal horn and around central canal. Compared with those of neonatal rats, these cells decreased prominently in adult rats. In aged rats, immunoreactive cells were not seen in any segments. c-Fos immunoreactivity in spinal cord may be related to stress response, functional differentiation, and in part, neuronal death with target dependence. In conclusion, we demonstrated for the first time that c-Fos expression patterns change during normal ageing.     

儿童消化性溃疡与幽门螺杆菌感染临床治疗探讨

为探讨儿童消化性溃疡(PU)与幽门螺杆菌(H.pylori)感染的关系,观察274例(4～14岁)有上消化道症状的儿童,男174例,女100例,电子胃镜证实PU。病理及H.pylori检测后,随机分为7组根除H.pylori。A、B组应用枸橼酸铋钾(CBS)和克拉霉素(CLA),A组加甲硝唑(MET)、B组加呋喃唑酮(FUR),疗程7d。D组标准三联疗程14d。A、D两组再加泰胃美6周。质子泵抑制剂(PPI)组洛赛克和CLA,加另一抗生素AMO(C组)、MET(E组)、FUR(F组)疗程7d。G组Smecta、AMO和MET疗程14d。停药4周以上复查胃镜和/或~(13)C-尿素呼气试验(~(13)C-UBT)。结果:①274例患儿H.pylori检出率79.93％,胃镜见十二指肠溃疡95.26％,慢性浅表性胃炎(CSG)89.42％,胃粘膜炎症和溃疡活动度与H.pylori感染有显著相关(P<0.01)。②治疗后1周内PPI组和铋剂A、B两组腹痛缓解均≥90％,各组腹痛消退时问比较差异有显著性(P<0.01);停药4周以上复胃镜53例,溃疡愈合和消失88.68％。③随访210例,H.pylori转阴81.43％、耐药14.29％,复燃2.86％,再感染1.43％,各组转归之间差异无显著性(P>0.05)。用胃镜复查H.pylori转阴75.76％;用~(13)C-UBT检测H.pylori转阴82.17％;胃镜联合~(13)C-UBT检查20例,H.pylori转阴90％,随访方式与转归之间有显著相关(P<0.01)。表明H.pylori是小儿PU的     

Developmental changes in multispecific organic anion transporter 1 expression in the rat kidney

BACKGROUND: The cDNA of the multispecific organic anion transporter 1 (OAT1) responsible for the tubular secretion of organic anions was recently isolated. In the current study, we investigated the developmental changes in OAT1 expression in the rat kidney. METHODS: Ontogenic expression of rat OAT1 was investigated by Northern blot, in situ hybridization, Western blot, and immunohistochemical analysis. In addition, para-aminohippurate (PAH) accumulation was measured using fetal, neonatal, and adult rat kidney slices. RESULTS: In Northern blot analysis, OAT1 was detected as early as on embryonic day 18 in the fetal kidney. The expression level of OAT1 mRNA increased remarkably just after birth (postnatal day 0). In situ hybridization revealed OAT1 expression on embryonic day 19. In both the fetal and neonatal kidneys, OAT1 mRNA was localized in a relatively deep region in the cortex. Western blot analysis detected OAT1 protein on embryonic day 20, and the expression level increased after birth. Immunohistochemical analysis did not reveal OAT1 staining in the fetal kidneys. A faint signal of OAT1 protein was detected on postnatal day 0; thereafter, the expression level increased. In the functional study using kidney slices, low but definite probenecid-sensitive PAH accumulation was noted in fetal rat kidney on embryonic day 20. After birth, probenecid-sensitive PAH uptake was increased. CONCLUSIONS: The present study consistently demonstrates the remarkable increase of OAT1 expression after birth, and the immature excretory capacity of the proximal tubules of the neonatal kidney can be attributed, at least in part, to the low expression level of OAT1.