Hironobu Adachi

Apoptosis in the human allografted kidney. Analysis by terminal deoxynucleotidyl transferase-mediated DUTP-botin nick end labeling.

Apoptosis is a distinct form of cell death and occurs under a variety of physiological and pathological conditions. This study was conducted to examine the occurrence of apoptotic cell death in 44 formalin-fixed, paraffin-embedded biopsy specimens from allografted kidneys by the terminal deoxynucleiotidyl transferase (TdT)-mediated D-UTP-biotin nick end labeling (TUNEL) method. Careful observation of routine hematoxylin and eosin sections revealed a few apoptotic cells in cortical tubules. TUNEL signal was detected variably in tubular epithelia, and occasionally in lymphocytic cells and endothelium. The number of tubular epithelia demonstrating TUNEL signals was highest for cyclosporine tubulopathy, followed by acute rejection of very mild or mild grade, and then by chronic allograft nephropathy. Protocol biopsies from normally functioning grafts showed the least apoptotic cells, with the number being significantly lower than that of both cyclosporine tubulopathy (P<0.01) and acute rejection (P<0.05). Two specimens of acute accelerated rejection with diffuse hemorrhagic necrosis showed nonspecific signals in a few epithelia. These findings suggest that acute rejection or cyclosporine nephropathy not infrequently induces apoptosis of tubular epithelia, which might lead to tubular atrophy or loss, resulting in chronic transplant nephropathy.

Expression of cyclo-oxygenase-2 is correlated with high intratumoral microvessel density and low apoptotic index in human esophageal squamous cell carcinomas

Abstract. Cyclo-oxygenase (COX) is a key enzyme in the conversion of arachidonic acid to prostanoids. COX-2 expression has been found in many malignancies. This study analyzed the correlation between COX-2 expression and angiogenesis or apoptosis in human esophageal carcinomas. The study examined the expression of COX-2 in six esophageal carcinoma cell lines and in 100 esophageal squamous cell carcinomas, comparing intratumoral microvessel density (IMVD) and apoptotic index (AI) by immunohistochemistry and TUNEL methods. COX-2 was variably expressed in all the cell lines examined. COX-2 immunoreactivity was observed mainly in the cytoplasm of carcinoma cells. Significantly higher mean IMVD and lower AI were noted in the 51 strong COX-2 expressing cases than in the 49 weak cases. IMVD and AI were negatively correlated. COX-2 expression was higher in the tumors with lymphatic invasion than in the others. These data indicate that COX-2 expression is associated with increased intratumoral microvessels and suppression of tumor cell apoptosis. Thus COX-2 might play an important role in the angiogenesis and regulation of apoptosis in esophageal squamous cell carcinomas.

Expression of RUNX3 protein in human gastric mucosa, intestinal metaplasia and carcinoma.

Background  Human runt‐related transcription factor gene 3 (RUNX3) is considered as a possible candidate of tumour suppressor gene in human gastric carcinoma.

Human herpesvirus‐6 infection in renal allografts: retrospective immunohistochemical study in Japanese recipients

This study was conducted to determine the incidence and clinical significance of human herpesvirus-6 (HHV-6) infection in renal allografts. A total of 105 biopsy specimens from 72 recipients were immunohistochemically examined for the presence of HHV-6 antigen, which localized in the distal tubular epithelial cells and in a few lymphocytes infiltrating into the interstitium. HHV-6 antigen in the tubular epithelia was detected in 63 (61.2%) specimens. Categorically, a higher incidence of the antigen was noted in specimens of accelerated rejection (3/4, 75.0%), acute rejection (28/3, 73.7%), and cyclosporin nephropathy (8/11, 72.7%). The antigen was present and absent an almost equal number of times in the categories of chronic rejection, intraoperative and routine protocol biopsies. Repeated biopsies were performed in six cases showing HHV-6 antigen, only one of which underwent transplant nephrectomy due to severe chronic rejection. Single or multinucleated giant cells in distal tubuli occurred in 10 (9.5%) specimens in a scattered manner. All of them were diagnosed as acute or chronic rejection. The giant cells showed no immunoreactivity for HHV-6, cytomegalovirus, or herpes simplex virus. These results indicate overall that HHV-6 infection is common in renal allografts and might be reactivated in acute rejection or cyclosporin nephropathy. The presence of HHV-6 antigen, however, does not necessarily correlate with a poor prognosis for the renal graft nor with the occurrence of giant cells in distal tubuli.

Expression of Fas and Fas ligand in human gastric adenomas and intestinal-type carcinomas: correlation with proliferation and apoptosis

Background. Fas (APO-1/CD95), a member of the tumor necrosis factor/nerve growth factor receptor superfamily, mediates apoptosis in response to agonistic antibodies or Fas ligand (FasL) binding. Previous reports indicated an upregulation of FasL in gastric carcinomas to evade host immune attack. Fas/FasL expression, however, has not been analyzed in terms of apoptosis and proliferation in gastric adenoma and carcinoma. Methods. This study was conducted on seven human gastric carcinoma cell lines, 47 gastric adenomas, and 75 intestinal-type adenocarcinomas (48 early and 27 advanced carcinomas). Fas/FasL expression was examined by immunohistochemistry, apoptosis by the terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling (TUNEL) method, and Fas gene mutation by a reverse transcriptase (RT) polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and sequencing method. Results. Fas and FasL expressions were noted in 18 (38.3%) and 17 (36.2%) adenomas, in 21 (43.8%) and 33 (68.8%) early carcinomas, and in 10 (37.0%) and 19 (70.4%) advanced carcinomas, respectively. The frequency of FasL expression was significantly higher in advanced carcinomas than in the early carcinomas and adenomas; in contrast, there was no significant difference in Fas expression among the three groups. The mean apoptotic index (AI) was 4.96 ± 0.51 in the adenomas, 2.96 ± 0.23 in the early carcinomas, and 1.67 ± 0.17 in the advanced carcinomas. A significantly higher AI was noted in the lesions with Fas expression than in those without Fas expression in all three groups. No missense mutations of the Fas gene were detected in any of the gastric carcinoma cell lines, or in the gastric adenomas or carcinomas. Conclusions. Upregulation of FasL may correlate with the progression of gastric carcinoma. Apoptosis in gastric adenoma and carcinoma cells may occur via Fas-dependent and -independent pathways, but further clarification is needed.

Expression of Cyclooxygenase-1 and Cyclooxygenase-2 in Human Esophageal Mucosa, Dysplasia and Carcinoma

Objective: COX (cyclooxygenase), a prostaglandin H synthase, catalyzes the rate-limiting step in prostaglandin biosynthesis. Two isoforms of COX have been identified: COX-1 and COX-2. We examined the expression of COX-1 and COX-2 in esophageal normal mucosa, dysplasia and squamous cell carcinoma (SCC). Methods: The expression of COX-1 and COX-2 in 80 surgically removed esophagi due to SCC, as well as in 5 human esophageal SCC cell lines was analyzed, using immunohistochemistry and Western blot analyses. Results: COX-1 and COX-2 were variably expressed in the SCC cell lines. Higher COX-1 expression was noted in 31 (41.9%) of the 74 specimens of normal mucosa, in none of the 40 specimens of dysplastic mucosa and in 15 (18.8%) of the 80 specimens of SCC, the frequency being significantly higher in normal mucosa than in dysplasia or SCC (p < 0.0001, p = 0.0018, respectively). COX-1 expression was significantly higher in well-differentiated SCC than in moderately or poorly differentiated SCC (p < 0.01). Higher COX-2 expression was noted in none (0.0%) of the specimens of normal mucosa, in 12 (30%) of the specimens of dysplastic mucosa, and in 41 (51.3%) of the speciments of SCC, the frequency being significantly higher in SCC than in normal mucosa or dysplasia (p < 0.0001, p = 0.0278, respectively). Conclusions: COX-1 is expressed in normal esophageal mucosa and is occasionally induced in well-differentiated SCC, whereas COX-2 expression is more characteristic of dysplasia and carcinoma than of normal mucosa, implying a possible association with cell differentiation in the former, and esophageal tumorigenesis in the latter.

Thymidine phosphorylase expression causes both the increase of intratumoral microvessels and decrease of apoptosis in human esophageal carcinomas

Thymidine phosphorylase (dThdPase)/platelet‐derived endothelial cell growth factor, is expressed at higher levels in tumor tissues compared to the adjacent normal tissues in a variety of human carcinomas. The higher expression is associated with an increase of intratumoral microvessel density (IMVD) and an unfavorable patient prognosis. We examined the role of dThdPase in apoptosis, IMVD, P53 expression and patient prognosis of human stages II and III esophageal squamous cell carcinomas (SCC). dThdPase expression was noted in 52 of the 78 esophageal SCC (66.7%), regardless of tumor stages and histologic grades. Mean IMVD was 117.9 ± 32.6 in the dThdPase‐positive cases and 103.1 ± 21.5 in the dThdPase‐negative cases, the value being significantly higher in the former (P < 0.05). Similarly, median (range) apoptotic index (AI: percentage of apoptotic cells) was significantly lower in the dThdPase‐positive SCC, 1.8 (0.4–6.5), than in the dThdPase‐negative SCC, 3.7 (0.6–7.0) (P < 0.01). AI and IMVD showed a significant inverse correlation (r= − 0.31, P = 0.005). There was also no significant difference in the frequency of P53 expression between the dThdPase‐positive SCC and the negative SCC. No statistical difference was noted regarding the postoperative survival rate between the dThdPase‐positive and the negative SCC. Although dThdPase expression was not associated with patient prognosis, the expression provided an advantage for tumor growth of human esophageal SCC, not only by increasing the intratumoral microvessels, but also attenuation of apoptosis, which might occur via a p53 gene‐independent pathway.

Thymidine phosphorylase expression results in a decrease in apoptosis and increase in intratumoral microvessel density in human gastric carcinomas.

Abstract Thymidine phosphorylase (dThdPase) / platelet- derived endothelial cell growth factor (PD-ECGF) is expressed at higher levels in a variety of human carcinomas than in adjacent normal tissue. The higher expression is associated with an increase in intratumoral microvessel density (IMVD) and an unfavorable patient prognosis. This study examined the role of dThdPase in apoptosis, IMVD and p53 expression in human gastric carcinomas. dThdPase expression was noted in 12 (35.3%) of 34 early carcinomas, and in 20 (55.6%) of 36 advanced carcinomas. At least 10 areas consisting of carcinoma cells with diffuse dThdPase expression from the 32 dThdPase-positive tumors (category I), and 10 areas without dThdPase expression from the 38 negative tumors (category II) were selected from each case. For early gastric carcinoma, the mean IMVD was 88.8±19.4 in category I and 61.4±17.3 in category II carcinomas, while for advanced gastric carcinoma, the mean IMVD was 98.8±21.0 in category I and 76.0±27.1 in category II carcinomas. The mean IMVD was significantly higher in category I than in category II tumors (P<0.05). The mean apoptotic index (AI: percentage of apoptotic cells) was 1.95±1.30 in category I, and 3.76±1.49 in category II carcinomas for early gastric carcinoma, and 1.51±0.98 in category I and 2.14±0.66 in category II carcinomas for advanced gastric carcinoma, the value of the mean AI being significantly (P<0.05) higher in dThdPase- negative tumors (category II) than in the positive tu-mors (category I), regardless of tumor stage or histological type. There was a significant inverse correlation (P<0.001) between AI and IMVD. These results indicate that dThdPase expression is associated with both an increase in intratumoral microvessels and a decrease in apoptosis in human gastric carcinomas.

Elastofibroma of the sigmoid colon.

A case of elastofibroma occurring in the sigmoid colon of a 69 year-old woman is reported. The woman presented for survey of her gastrointestinal tract. Colonoscopy disclosed two polyps in the sigmoid colon, one of which was clinically considered to be recurrent adenoma. Histologically, the lesion had characteristic eosinophilic fibers and globules, termed elastofibroma fibers with hematoxylin and eosin stain. In addition, these elastinophilic materials were digested by elastase. Histological evaluation confirmed the diagnosis of elastofibroma. Our case might suggest that it is the result of long-term fibrosis after previous endoscopic resection of a sigmoid colonic adenoma.

Mast cells in human allografted kidney: correlation with interstitial fibrosis

Abstract: Introduction: Chronic allograft nephropathy is the major cause of long‐term graft failure in human allografted kidney transplantation. In addition to macrophages and T lymphocytes, mast cells have been shown to increase in chronic allograft nephropathy. The present study examined tryptase‐positive mast cells and microvessels in the allografted kidney.