Expression of Proliferating Cell Nuclear Antigen(PCNA) in biopsy and autopsy specimens of gastric carcinoma

Although proliferating cell nuclear antigen (PCNA) is known to be an indicator of malignant potential in tumors, the biological and clinicopathological significance of PCNA in tumor tissue is controversial. Methods : Immunohistochemical expression of PCNA was examined in 58gastric carcinoma tissues obtained at autopsy to test the clinicopathological significance. In addition, in 24 of the 58 tumor tissues we compared immunohistochemical expression of PCNA in biopsy and autopsy specimens from the same patient in order to know whether the proliferating activity of tumor cells is stationary from the early stage to the end of tumor growth. Results : 1. PCNA was undetectable in some tumor tissues (12.5% in biopsy and 10.3% in autopsy specimens). 2. the frequency of PCNA positive cases and labeling index (LI) (%) of PCNA in tumor tissues were not significantly different between biopsy and autopsy specimens. 3. the intensity of PCNA reaction was not related to prognosis. 4. PCNA positive cases and LI did not correlate with survival condition. Conclusion : It is hard to say whether PCNA is a reliable indicator in predicting malignancy and prognosis of gastric cancer

FAMILIAL ALZHEIMER’S DISEASE

Five different types of point mutation of the β-amyloid precursor gene (APP) have been reported to cosegregate with familial Alzheimer’s disease (FAD) in each of examined pedigrees (Table 1). Here we report a screening result of the APP gene mutations in two Japanese pedigrees with FAD of an early onset type which have previously been reported (2, 3). Primer pairs corresponding respectively to each of 19 exons of the APP gene were designed. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis was performed on genomic DNA of one affected member from each of these two pedigrees. In addition, a pair of primers was designed to assess specifically codon 717 of the APP gene even in the poorly-preserved sample of genomic DNA. PCR-SSCP analysis of all 19 exons of the APP gene of both patients did not show any mutations, but disclosed one polymorphism in the intron 9. Sequencing of exons 16 and 17 of the APP gene in both patients, where all reported pathogenic mutations are located, revealed normal sequences. The results support that the genetic defect causing FAD is heterogeneous and that most cases with FAD are apparently due to the gene-defect of other than the APP gene

Vital immunohistochemical staining for a novel method of diagnosing micro-cancer -examination of immuno-histochemical staining of non-fixed fresh tissue-

It becomes possible to establish a novel diagnostic method for micro-cancer by modulating the signals from the lesion, if lesions can be labeled with substances which can be detected by video endoscopy. The authors have already succeeded in synthesizing indocyanine green (ICG) derivatives for a fluorescent labeling substance which emits near-infrared rays. Before the antibodies labeled by these substances can be used, it is necessary to establish a method of vital immunohistochemical staining. So, we inves-tigated the responses of antibodies exposed to non-fixed fresh tissue specimens as a basic study on vital immunohistochemical staining. The responses of fresh esophageal and gastric specimens (biopsied or surgically resected) to immunohistochemical staining with anti-epithelial membrane antigen (EMA) antibodies under various conditions using the ABC method were examined. These tissue specimens were stained immunohistochemically, and incubated with anti-EMA antibodies for 10 and 30 minutes (esophagus), and for 60 and 120 minutes (stomach) at 37°C. These results suggest that vital immunohistochemical staining is possible under optimum conditions. If an infrared fluorescent endoscopy catching this excited fluorescence can be developed, it will be possible to establish a new endoscopic diagnostic method on the basis of vital immunohistochemical staining

Histological reaction of auditory bulla bone to synthetic auditory ossicle (Apaceram®) in rats

To investigate the biocompatibility of a synthetic auditory ossicle to host bone, small thin Apaceram® disks composed of dense hydroxyapatite were implanted under the periosteum of the left auditory bulla in 32 rats for periods ranging from 1 day to 270days. A sham operation performed on 10 rats served as a control. Decalcified histological sections stained with hematoxylin and eosin were observed using light microscopy. The experiment showed:1) a time-dependent mature fibrous connective tissue surrounding the Apaceram® disk, 2) no evidence of inflammatory reaction caused by the implant from 90 days after implantation until the end of the experiment, 3) no evidence of osteolysis by osteoclasts caused by the implant, and 4) direct contact of bone to the implant on the bone-disk interface at 180 and 270 days after implantation. The findings suggest that Apaceram® has a high degree of implant biocompatibility, making it a satisfactory substitute biomaterial for otological reconstructive surgeries

Inhibitory Effect of 1α-Hydroxyvitamin D3 on N-nitrosobis (2-oxopropyl)Amine-induced Cholangiocarcinogenesis in Syrian Hamsters

Sixty-three male 5-week-old Syrian hamsters received the carcinogen N-nitrosobis(2-oxopropyl)amine (BOP) s.c. in 5 weekly injections (the first, 70mg/kg body, and the remaining, 20mg/kg each). The hamsters that received BOP were given intragastric administration of 0.2ml of medium chain triglyceride (MCT) with or without 0.04μg of 1α-hydroxyvitamin D3 [1α(OH)D3] through a feeding tube for 12 weeks. Thus, 3 groups were assigned:Group 1;BOP alone (n＝20), Group 2;BOP＋MCT (n＝18) and Group 3;BOP＋1α(OH)D3 (n＝25). The mean body weight of Group 3 was lower than those of Groups 1 and 2 at the end of the experiment (p＜0.001,Tukey-Kramer HSD test). At the end of week 12, all surviving hamsters were put to sleep. The incidences of liver tumors were 80%, 72% and 32% in Groups 1, 2 and 3, respectively. The incidence of tumors in Group 3 was significantly lower than in Group 1 and Group 2 (p＜0.05, χ2-test). All tumors were cholangiocarcinoma. These results indicated that BOP-induced cholangiocarcinogenesis was suppressed by the supplemental administration of 1α(OH)D3

A subcutaneous tissue reaction in the early stage to a synthetic auditory ossicle (Bioceram®) in rats

The discs of synthetic auditory ossicle (Bioceram®), which are composed of aluminium oxide (Al2O3), were implanted subcutaneously in the interscapular region of 16 rats. The implanted specimens were removed at 1, 3, 7 and 14 days after implantation. The decalcified 6 μm thick sections were stained with H.E. and cell types around the implants were counted microscopically. We found that an acute inflammatory reaction occurred at one day, in which macrophages and neutrophils predominated, and almost disappeared at about 7 days after implantation. Fibrosis began to be observed at 3 days. During this early stage, foreign body giant cells were found in only one specimen at 3 days. These findings, in comparison with those in the controls, showed that the chemical irritation of Bioceram® to the subcutaneous tissue is slight, although the physical and/or chemical irritation of Bioceram® lasts continuously and induces fibrosis around the bioimplant. The results so far suggest that Bioceram® seems to be a satisfactorily biocompatible material, at least within the extent of 2 weeks

Long-term observation of subcutaneous tissue reaction to synthetic auditory ossicle (Bioceram®) in rats

To evaluate biocompatibility to tissue in long-term implantation, Bioceram® discs made of aluminum oxide (Al2O3) were implanted subcutaneously within the interscapular region of 64 rats for six to 20 months. Histological sections stained with haematoxylin and eosin (H&E) and the surface of the implant material were observed using light micros-copy. Different cell types and the thickness of fibrous capsules surrounding the implants were examined quantitatively by light microscopy. Small numbers of macrophages (2.8±0.7%) and lymphocytes (2.7±0.9%) were observed at six months after implantation, gradually decreasing to zero at 16, 18 and 20 months. Neither neutrophils nor foreign body giant cells were seen in any specimens. The thickness of fibrous capsules surrounding the implants was closely related to the shape of the implant, but there was no significant change between six and 20 months after implantation. No change in Bioceram® surfaces were observed under stereoscopic microscopy from six to20months after implantation. The study results indicate that Bioceram® is a satisfactory biocompatible material for reconstructive surgery from the viewpoint of long-term tissue response. Present results of experiments with Bioceram® are also compared to previous results with Apaceram® and different tissue responses of the two materials are discussed