Analysis of side population cells derived from dental pulp tissue.

AIM: To investigate the characteristics of side population (SP) cells derived from the dental pulp of young and aged rats. METHODOLOGY: Maxillary and mandibular incisors were extracted from 5-week-old (young) rats and 60- to 80-week-old (aged) rats. Coronal pulp tissue was removed mechanically, and single-cell suspensions were prepared using collagenase and dispase. Cells were stained with Hoechst 33342 and sorted with an fluorescence-activated cell sorter (FACS). Isolated SP and main population (MP) cells were analysed by real-time reverse transcription polymerase chain reaction, immunohistochemical localization and cell cycle determination. Two-way analysis of variance and the multiple comparison Scheffè test were used for statistical analysis (P<0.05). RESULTS: Approximately 0.40% of pulp cells in young rats and 0.11% in aged rats comprised SP cells. SP cells expressed a higher mRNA level of ATP-binding cassette transporter G2 (ABCG2), but lower mRNA levels of nestin, alkaline phosphatase, p16 and p57 than MP cells in both age groups. Immunohistochemical observation revealed ABCG2-positive cells localized in the cell-rich zone and nestin in the odontoblastic layer in both groups. Furthermore, the majority of both young and aged SP and MP cells were in growth arrest of the G(0) /G(1) phase. CONCLUSION: The FACS analysis revealed a decrease in the proportion of SP cells with age, whilst p16 mRNA expression indicated an increase in cell senescence. The cell cycles of SP and MP cells from both young and aged dental pulp were generally in the G0/G1 phase.

Schedule-dependent combined sensitivity testing of anti-cancer agents in human gastric carcinoma cell lines.

The efficacy of combination chemotherapy for gastric carcinoma has been unsatisfactory, although the prognosis of advanced and recurrent disease has improved with the introduction of cisplatin (CDDP). This study examines the effect of the anti-cancer therapies CDDP, doxorubicin (ADM) and etoposide (VP-16) on the cell cycle and their cytotoxicity against two gastric carcinoma cell lines: MKN-28 (well differentiated) and MKN-45 (poorly differentiated). The treatments have different cytocidal mechanisms, and they were studied in dual combinations. For all combinations studied, cytotoxicity against MKN-45 was higher than against MKN-28. For ADM plus CDDP, or ADM plus VP-16, cytotoxicity was higher in patients pretreated with ADM than other regimens. The highest anti-tumour activity against both cell lines was obtained with ADM followed by CDDP (we have obtained good clinical results with this regimen). Schedule-dependent combined sensitivity testing of anti-cancer agents will be useful for the clinical application of therapies.

Endoscopic submucosal tumor biopsy using Stiegmann-Goff endoscopic ligator.

Endoscopic biopsy is an important tool for histological diagnosis of lesions residing in gastrointestinal tracts. However, it is less useful in submucosal lesions due to the existence of normal overlying mucosa. We developed a new and safe technique for the diagnosis of submucosal tumor using Stiegmann-Goff endoscopic ligator. After removing surface mucosa to expose submucosal tissue by this method, conventional secured histological diagnosis could be performed. To determine definitive histological diagnosis, this technique is useful as well as Endoscopic Ultrasound (EUS) with fine needle aspiration biopsy and other modalities.

A case of rectal Dieulafoy's ulcer and successful endoscopic sclerotherapy.

A 54-year-old woman presented a massive hematochezia 7 days after sigmoidectomy. Repeated colonoscopy and angiography failed to locate the site of bleeding and Hartman's operation was performed. Rebleeding from the rectum on the day of operation occurred and pulsate arterial bleeding with minimal surrounding ulcer 1 cm above the pectinate line was observed. Screlotherapy with ethanol and electro coagulation was successfully performed to achieve permanent hemostasis. The importance of detailed rectal examination and an awareness of this clinical entity in life-threatening lower intestinal bleeding is discussed.

Lymphovascular and neural invasion in low-lying rectal carcinoma.

We have previously demonstrated that lymphovascular infiltration was correlated with an increased risk for developing lymph node metastasis in rectal adenocarcinomas confined within the submucosal layer. In another study, lymphovascular infiltration was also correlated with poor prognosis for patients with advanced rectal cancers. Considerations that low rectal tumors have an increased risk to develop recurrence and neural invasion have been recently implicated with a more localized pattern of tumor spread. We therefore assessed the lymphovascular and neural invasion in 65 specimens from patients with low rectal cancers who underwent curative operation to determine its implications in the treatment and prognosis. Lymphovascular invasion was noted in 60%, and neural invasion was found in 27% of the cases. Five-year survival rates (Kaplan-Meier method) were significantly decreased in patients with lymphovascular invasion (31 vs. 67%; p < 0.01) or neural invasion (30 vs. 58%; p < 0.01). Neither lymphovascular nor neural invasion was noted in Dukes' stage A tumors. There was no recurrence or distant metastasis in these patients. However, lymphovascular and neural invasion increased with tumor stage. Local recurrence and distant metastasis occurred respectively in three and four, and five and five patients with Dukes' B and C tumors, respectively. Both Dukes' B and C cases with local recurrence had a higher incidence of neural invasion as compared with the disease-free group. These results suggest that postoperative assessment of venous and neural invasion may provide valuable information to better determine which patients with low rectal cancers would benefit from adjuvant treatment.

[A case of pancreatic cancer surviving for 7 years 11 months following intra-arterial and portal infusion chemotherapy].

A case of unresectable pancreatic cancer in a 76-year-old female was reported, in which a tumor had liver involvement. She was treated with infusion chemotherapy of mitomycin C (MMC) from gastroduodenal artery and portal vein after palliative operation. A drug was administered via an extracorporeal infusion catheter. MMC was given totally 47 mg from artery and 27 mg from portal vein for 9 months. Then, the serum CA 19-9 level gradually decreased, the metastatic liver tumor disappeared and the pancreatic tumor became smaller. After that, the tumor did not grow. The patient survived for 7 years 11 months until she died from other causes. Thus, it seems that infusion chemotherapy might be tried in some cases of pancreatic cancer.

[The expression of neural cell adhesion molecule (NCAM), neural invasion and recurrence patterns in rectal cancer--a study using anti-NACM (neural cell adhesion molecule) antibody].

Neural invasion may be one of the main causes of local recurrence, but its mechanism has not been sufficiently clarified. We previously reported that the expression of NCAM on cancer cells was correlated with neural invasion in pancreatic cancer. In this study, we examined the neural affinity of rectal cancer cells and the relationship between neural invasion and recurrence patterns of rectal cancers. A total of 64 rectal adenocarcinoma were examined. Specimens from 17 patients (27%) revealed perineural invasion. The incidence of neural invasion increased with the frequency of venous invasion and the degree of lymph node metastasis, but not significantly. The incidence of the expression of NCAM in rectal cancer cell was 45.3 percent. Neural invasion of rectal carcinoma was significantly related to the expression of NCAM (p < 0.05). NCAM immunocytolocalization was classified into the focal type, and the diffuse type. Concerning the recurrence type, 8 of 9 cases that developed local recurrence showed either presence of neural invasion or expression of NCAM. Liver metastasis was associated with absence of neural invasion or NCAM expression. The expression of NCAM may contribute to local recurrence, whereas the absence of NCAM may predict liver metastasis.

[Flow cytometric DNA analysis of papillary carcinoma of the thyroid using paraffin-embedded specimens].

A flow cytometric DNA analysis of papillary thyroid carcinomas has been performed on paraffin-embedded specimens, in order to determine the clinical usefulness of this method by defining the degree of the biological malignancy. Fifty-eight patients with papillary carcinomas were followed from 2 to 8 years. They were classified according to their prognosis into three groups: non-recurrent (47 patients), recurrent (5 patients), and a deceased group (6 patients). Aneuploidy was found in 6 (10.3%) of the total 58 patients. It was more frequently detected in the recurrent (40%) and in the deceased (33.3%) groups than in the non-recurrent group (4.3%). Higher proliferating index values were observed in the deceased group than in the recurrent and non-recurrent groups. These results indicate that a DNA analysis, using routine paraffin-embedded materials, is a useful adjunct in the determination of the degree of the biological malignancy of a papillary carcinoma.

Clinical availability of serum fructosamine measurement in diabetic patients with uremia. Use as a glycemic index in uremic diabetes.

Serum fructosamine levels were investigated in patients with uremia undergoing various modes of treatment. The serum fructosamine levels correlated positively with the blood glucose levels determined a week or two earlier. The fructosamine levels were significantly affected by the protein concentration, and those corrected for protein concentrations had a closer correlation to the blood glucose levels than did the uncorrected levels. The corrected fructosamine levels were not significantly different between healthy volunteers and nondiabetic patients with uremia on conservative treatment. In an in vitro system, fructosamine concentrations were hardly affected by urea, which is known to influence the level of hemoglobin A1. These results suggest that serum fructosamine measurement can provide us with reliable information on a short-term glycemic condition, even in azotemic patients. To be more precise, the serum level of fructosamine corrected for protein concentration can be an excellent glycemic index which is not susceptible to over- or dehydration and is of high clinical value, especially in the management of diabetic patients with chronic renal failure.

X-ray diffraction studies of enkephalins. Crystal structure of [(4'-bromo) Phe4,Leu5]enkephalin.

In order to investigate the structure-activity relationship of [Leu5]- and [Met5]enkephalins, [(4'-bromo)Phe4, Leu5]-, [(4'-bromo)Phe4, Met5]- and [Met5] enkephalins were synthesized and crystallized. The crystal structure of [(4'-bromo) Phe4, Leu5]- enkephalin was determined by X-ray diffraction method using the heavy atom method and refined to R = 0.092 by the least-squares method. The molecule in this crystal took essentially the same type I' beta-turn conformation found in [Leu5]enkephalin [Smith & Griffin (1978) Science 199, 1214-1216). On the other hand, the preliminary three-dimensional Patterson analyses showed that the most probable conformations of [(4'-bromo)Phe4,Met5]- and [Met5]enkephalins are both the dimeric extended forms. Based on these insights, the biologically active conformation of enkephalin was discussed in relation to the mu- and delta-receptors.

Isolation of Rickettsia tsutsugamushi antigenically different from Kato, Karp, and Gilliam strains from patients.

Rickettsia tsutsugamushi strains from three recent patients of Tsutsugamushi disease in Niigata Prefecture were isolated primarily in mice and then in L cell cultures. By this procedure, low virulent strains to mice, as well as high virulent ones, could be isolated and cultivated serially in L cell cultures, suggesting the usefulness of L cells for isolation of this species of rickettsia. Each newly isolated strain was identified as a member of R. tsutsugamushi from the results of cross immunological tests and morphological observation. On the other hand, it was recognized that one of these rickettsiae showed immunological properties distinguishable from the prototype strains of Kato, Karp, and Gilliam by the cross complement fixation test, and also had low virulence in mice.