Association of tumor cell proliferation with lymph node metastasis in early gastric cancer

Recently, many studies have reported on the relationship between malignant potential of neoplasms and cell proliferation. Proliferating cell nuclear antigen (PCNA) is an auxiliary protein of DNA polymerase delta and is considered to correlate with the cell's proliferative state. In this study, we investigated the correlation between tumor cell proliferation and nodal status of early gastric carcinoma. One hundred two endoscopically biopsied specimens from patients with early gastric carcinoma prior to operation were investigated by an immunohistochemical study, using anti-PCNA monoclonal antibody. Correlation of PCNA labeling index (percentage of positive cells per over 500 tumor cells) with nodal status were studied. PCNA labeling index in patients with lymph node metastasis was significantly higher in those without metastasis. Moreover, multivariate analysis indicated that PCNA labeling index is an independent significant factor for lymph node metastasis. As a result of this study, PCNA labeling index was suggested to be effective as one of the predictors of lymph node metastasis.

Immunocytochemical localization of phenylalanine ammonia-lyase in tissues of Populus kitakamiensis

The polypeptide encoded by the partial fragment of cDNA of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), PALcDNA1 (Osakabe et al., 1995, Plant Sci. 105: 217-226), isolated from Populus kitakamiensis (P. sieboldii x P. grandidentata), was expressed in Escherichia coli cells. The polypeptide was purified and an antiserum raised against it. The antiserum recognized a protein of 77 kDa on nitrocellulose blots after sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total protein and the partially purified PAL protein from P. kitakamiensis. Moreover, the antiserum recognized a protein on the blot after non-denaturing polyacrylamide gel electrophoresis of P. kitakamiensis proteins and this protein had PAL activity. Furthermore, the antibody inhibited PAL activity of extracts from stem tissues. These results showed that the antiserum against the partial PAL peptide recognized only the PAL subunits in extracts of P. kitakamiensis. Immunolocalization studies of P. kitakamiensis tissues revealed that the PAL protein was specifically localized in the xylem and the phloem fibers and no immunogold signal was found in the epidermis, the cortex, the pith, or the cambium of either stems or leaves.

Age-related changes in composition of transcription factor, AP-1 complex in the rat brain

We examined age-related changes in composition of transcription factor, activator protein-1 (AP-1) which binds to TPA responsive element (TRE) in the non-stimulated rat brain, using electrophoretic mobility-shift assay with immunodepletion/supershift assay. The total TRE-binding activity in the frontal cortex and the hippocampus of the aged rats markedly decreased to 66% and 43%, respectively, and TRE-bindings of AP-1 in both regions also decreased to 82% and 66%, respectively, with aging. Jun-Jun dimers accounted for approximately half of the total TRE-bindings and 80-90% of the AP-1 bindings, while there were fewer Fos-Jun dimers, in both examined regions of the non-stimulated adult. The proportion of active Fos-Jun heterodimers in the frontal cortex increased to up to half of the AP-1 bindings in the aged rats, indicating that cortical AP-1-related transcription may increase with aging even under the non-stimulated condition. In the hippocampus, inactive Jun-Jun homodimers became predominant in AP-1 with aging. This regional diversity of age-related changes in the composition of AP-1 in the brain may be related to changes or dysfunction in neuronal signal transduction in the aged.

Pertussis toxin inhibits phospholipase C activation and Ca2+ mobilization by sphingosylphosphorylcholine and galactosylsphingosine in HL60 leukemia cells. Implications of GTP-binding protein-coupled receptors for lysosphingolipids

Extracellular sphingosylphosphorylcholine (SPC) and galactosylsphingosine (psychosine) induced Ca2+ mobilization in a dose-dependent manner in HL60 leukemia cells. The rapid and transient increase in intracellular Ca2+ concentration ([Ca2+]i) elicited by SPC and psychosine at concentrations lower than 30 microM was inhibited by treatment of the cells with pertussis toxin (PTX) and U73122, a phospholipase C inhibitor, as was the case for UTP, a P2-purinergic agonist. The increase in [Ca2+]i induced by these lysosphingolipids was associated with inositol phosphate production, which was also sensitive to PTX and U73122. The inositol phosphate response is not secondary to the increase in [Ca2+]i as evidenced by the observation that thapsigargin and ionomycin, Ca2+ mobilizing agents, never induced inositol phosphate production and, unlike lysosphingolipids, the [Ca2+]i rise by these agents was totally insensitive to PTX and U73122. When HL60 cells were differentiated into neutrophil-like cells by dibutyryl cyclic AMP, inositol phosphate and Ca2+ responses to AlF4- were enhanced, probably reflecting an increase in the amount of Gi2 and Gi3 compared with undifferentiated cells. In the neutrophil-like cells, however, the responses to SPC and psychosine were markedly attenuated. This may exclude the possibility that the lysosphingolipids activate rather directly PTX-sensitive GTP-binding proteins or the phospholipase C itself. Other lysosphingolipids including glucosylsphingosine (glucopsychosine) and sphingosylgalactosyl sulfate (lysosulfatides) at 30 microM or lower concentrations also showed PTX- and U73122-sensitive Ca2+ mobilization and inositol phosphate response in a way similar to SPC and psychosine. However, platelet-activating factor and lysoglycerophospholipids such as lysophosphatidylcholine and lysophosphatidic acid were less effective than these lysosphingolipids in the induction of Ca2+ mobilization. Taken together, the results indicate that a group of lysosphingolipids at appropriate doses induces Ca2+ mobilization through inositol phosphate production by phospholipase C activation. The lysosphingolipids-induced enzyme activation may be mediated by PTX-sensitive GTP-binding protein-coupled receptors, which may be different from previously identified platelet-activating factor receptor or lysophosphatidic acid receptor.

Intratumoral injection of an adriamycin immunoconjugate against human pancreatic cancer xenografts

We have evaluated the effect of an adriamycin conjugate of monoclonal antibody Nd2 (ADM-Nd2) on the growth rate of SW1990 xenografts grown subcutaneously in athymic nude mice. Intravenous or intraperitoneal administration of radiolabeled Nd2 resulted in a maximum tumor accumulation of approximately 45% of the initial dose/g of tumor 3-7 days after administration. However, administration into the tumor produced retention of 1200%ID/g 1 day after, with 50% of this high value remaining even at 7 days after administration. In contrast, intratumoral administration of a non-specific immunoglobulin showed a lower initial retention and rapid loss of label. Both intravenously and intratumorally administered ADM-Nd2 reduced the growth rate of SW1990 xenografts. While a single intravenous administration arrested growth for about two weeks, a single intratumoral injection prevented any increase in tumor size even 45 days after administration. Xenografts treated with ADM-Nd2 showed degenerative changes at the histological level. Neither Nd2 alone nor Adriamycin alone inhibited growth when administered at the same dose as the conjugate.

Nucleolar organizer regions in hepatocellular carcinoma related to the cell cycle, cell proliferation and histologic grade

In order to clarify factors which relate to AgNOR in hepatocellular carcinoma (HCC), AgNOR numbers and the expression of Ki-67 using MIB-1 antibody have been studied in paraffin-embedded specimens of 20 HCCs by means of a double staining method. We found that in individual cases the AgNOR number of MIB-1-positive cells was significantly higher than that of MIB-1-negative cells (p < 0.001). In addition, a significant correlation was seen between MIB-1 labelling index and the total mean AgNOR number (t-AgNOR) (r = 0.882, p < 0.001). The value of t-AgNORs was significantly higher in histologically less differentiated HCC (p < 0.005). The mean AgNOR number of MIB-1-negative cells (n-AgNOR) was also significantly higher in histologically less differentiated HCC (p < 0.04). By contrast, the mean AgNOR number of MIB-1-positive cells (p-AgNOR) did not significantly correlate with histologic grades (p = 0.265). However, the number of t-AgNORs was not significantly different between diploid and aneuploid tumours. In HCCs, it appears that AgNOR numbers were variably influenced by proliferative activities of tumour cells, phases of cell cycle and cell differentiation.

Effects of single cyclosporin A pretreatment on pentylenetetrazol-induced convulsion and on TRE-binding activity in the rat brain

Using electrophoretic mobility-shift assay (EMSA), we examined changes in DNA-binding activities of transcriptional factor-activated protein-1 (AP-1), which is a Fos-Jun protein complex, onto its responsive element TRE in the hippocampus and amygdaloid nucleus of rats stimulated with pentylenetetrazol (PTZ) injection, and also investigated the effects of a single administration of the immunosuppressant cyclosporin A (CsA). In EMSA with nuclear extracts from the rat brain, the TRE-binding activity of AP-1 in the hippocampus and amygdaloid nucleus markedly increased 2 h after the PTZ injection (75 mg/kg, i.p.). These PTZ-induced increases of the TRE-binding protein in these regions were completely suppressed, by pretreatment with CsA (5 mg/kg, s.c.) 1 h before the PTZ injection. In addition, the administration of CsA significantly ameliorated PTZ-induced convulsion. This therapeutic effect of single CsA pretreatment may be based, in part, on the effects on the TRE-binding activity of AP-1 in the brain. Since single pretreatment of CsA in the present study had no effect on the PTZ-induced induction of c-fos mRNA, c-jun mRNA, Fos protein nor Jun protein, the inhibitory effects of single CsA administration on PTZ-induced TRE-binding activity in the brain may be related to the effects of CsA on AP-1 itself. These results suggest that an immune response via activation of transcriptional factor in the brain tissue is involved in the convulsion.

[A study on the relationship between sensitivity to CDDP and inducibility of metallothionein and glutathione of genitourinary tumors]

BACKGROUND

In this paper we demonstrate the relationship between the antitumor activity of cis-diamminedichloroplatinum (II) (CDDP) and inducibility of metallothionein (MT) and glutathione (GSH) of genitourinary tumors.

METHODS

The chemosensitivity test was performed in athymic mice bearing tumors derived from the human tumor cell lines: ACHN (renal cell carcinoma), NMB-1 (urinary bladder transitional cell carcinoma), and NMT-1 (testicular embryonal cell carcinoma). A single dose of CDDP (25 mumol/kg body weight), was administered i.p. to athymic tumor bearing mice. Concentrations of platinum, MT, and GSH were measured in organ and tumor homogenates 24 h after CDDP administration.

RESULTS

We observed that tumors derived from NMB-1 and NMT-1 were very sensitive to CDDP, but ACHN derived tumors were resistant to CDDP. Measurement of platinum concentrations in tumor tissues revealed no correlation to the observed chemosensitivities of the tumors. Furthermore, 24 h after CDDP administration, the levels of MT and GSH in NMB-1 and NMT-1 derived tumors were lower them or equal to those of control mice. In contrast, mice bearing tumors derived from ACHN exhibited a 1.7-fold and a 2.1-fold increase in MT and GSH, respectively, as compared to control mice.

CONCLUSION

These findings suggest that the inducibility of MT and GSH in tumor tissues following CDDP administration may be a contributing factor in the development of CDDP resistance in renal cell carcinoma.

Comparative morphometric studies of benign and malignant intraductal proliferative lesions of the breast by computerized image analysis

Using computerized image analysis, we newly devised a method for automatic quantitative evaluation of nuclear arrangements in variable proliferative intraductal (cribriform) lesions of the breast, by calculating angles of longest nuclear diameter to a horizon (LNDA). Internuclear correlation in the cribriform lesions was thus examined, comparing 22 benign and 62 malignant cases. In the malignant lesions, nuclear arrangements tended to be multidirectional, probably because of vertical nuclear arrangements toward acinar lumens as reflected by the wide distribution of LNDAs. Conversely, in the benign lesions, groups of nuclei tended to arrange toward one certain direction, forming a complex streaming pattern with the distribution of LNDAs usually producing a distinctive peak. Other conventional nuclear features, such as nuclear area, nuclear perimeter, shortest nuclear diameter (SND), and leading variables were also quantitatively assessed for multivariate analysis. It was noted that nuclear arrangements could represent a favorable discriminator. Linear discriminant function could classify 66 of the total 84 cases (78.6%) as being consistent with the diagnosis of pathologists. We conclude that internuclear arrangement could be a useful discriminating variable in benign and malignant breast lesions for the further development of an automatic analytic system.

Tumour angiogenesis and tumour cell proliferation as prognostic indicators in gastric carcinoma

Tumour growth depends on neovascularisation and tumour cell proliferation. Factor VIII-related antigen (F-VIII RA) localises to vascular endothelium. Expression of proliferating cell nuclear antigen (PCNA) is correlated with cell proliferation. We investigated the correlation between the expression of these antigens and prognosis in gastric carcinoma. A total of 108 specimens resected from patients with gastric carcinoma were investigated by staining with monoclonal antibodies against F-VIII RA and PCNA. Microvessel count (MVC; the mean number of microvessels in the five areas of highest vascular density at 200 x magnification) and PCNA labelling index (PCNA LI; percentage of positive cells in more than 500 tumour cells) were determined. The results showed that prognosis was significantly worse in patients who had a tumour with a high MVC (16 or greater) or a high PCNA LI (42% or greater) than in those patients who had a tumour with a low MVC (less than 16) or a low PCNA LI (less than 42%). Furthermore, MVC was significantly associated with the risk of hepatic recurrence. In conclusion, both MVC and PCNA LI may be good prognostic indicators in patients with gastric carcinoma.

Six cases of microscopic polyarteritis exhibiting acute interstitial pneumonia

Out of 21 autopsy cases of microscopic polyarteritis (MPA), six cases that died of acute respiratory failure are described. All of these six cases exhibited pauci-immune necrotizing glomerulonephritis. Of these six cases, systemic vasculitis and respiratory failure occurred almost simultaneously in two, whereas respiratory failure developed when vasculitis recurred in the other four. Pathologically, pulmonary changes were diffuse and almost uniform in each case. Interstitial inflammatory cells (alveolitis), hyaline membrane, restructuring, and fibrosis were observed. The degrees of these changes differed from case to case; four cases showed predominantly exudative changes and two cases exhibited proliferative or organizing ones. Clinical and pathological features were consistent with acute interstitial pneumonia (AIP). Immunofluorescent and ultrastructural studies did not suggest deposition of immune complexes at the lesions of alveolitis. An etiologic agent could not be identified in these cases. Some lung lesions including pulmonary hemorrhage have been described in association with MPA; however, cases such as those presented here have rarely been reported. It was considered that AIP could be one of the pulmonary disorders in MPA. Furthermore, the possible pathogenetic role of antineutrophil cytoplasmic antibodies (ANCA) in the evolution of present lung lesion is discussed. Although ANCA were not examined in the present cases, these antibodies should be investigated in future cases.

Role of calcium in insulin-stimulated NaC1 transport in medullary thick ascending limb

It has been reported that insulin stimulates directly NaCl transport in the rabbit medullary thick ascending limb (MTAL) [O. Ito, Y. Kondo, N. Takahashi, K. Kudo, Y. Imai, K. Omata, and K. Abe. Am. J. Physiol. 267 (Renal Fluid Electrolyte Physiol. 36): F265-F270, 1994]. In the present investigation, we evaluated the role of Ca2+ in insulin-stimulated NaCl transport in rabbit MTAL by in vitro microperfusion methods. In control experiments, insulin increases transepithelial voltage (Vte) and net lumen-to-bath Cl-flux (JCl). The effects of insulin on Vte and JCl in a Ca2+ -free solution containing ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N' -tetraacetic acid did not differ from those in a Ca2+ -containing control solution. Direct measurements of cytosolic free Ca2+ ([Ca2+]i) with fura 2 fluorescence showed that insulin caused no detectable change in [Ca2+]i in MTAL cells. Chelation of intracellular Ca2+ with the acetoxymethyl ester of 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid inhibited the actions of insulin in Vte and JCl without affecting basal values. We examined further whether calmodulin is also involved in insulin-stimulated NaCl transport in MTAL using two dissimilar inhibitors of calmodulin, trifluoperazine (TFP) and N-(6-aminohexyl)-5-chloro-1-naphthalene-sulfonamide (W-7). TFP and W-7 inhibited the action of insulin in a dose-dependent manner, with maximal inhibition of both agents of > 90%. The half-maximal inhibition by TFP and W-7 was approximately 50 and 100 microM, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

[Electrolyte metabolism in renal tubules]

Obese, diabetic and hypertensive populations have an increased prevalence of hyperinsulinemia and insulin resistance with respect to glucose metabolism. Insulin is thought to contribute to hypertension by sodium retention in the kidney. Here we describe the direct effect of insulin on renal tubular transport. The ascending thin limb of Henle's loop (ATL) plays an important role in concentrating urine. However, it is still controversial whether Na+ reabsorption in this nephron segment is an active process or a passive one. Moreover hormonal regulation of Cl- transport in the ATL is completely unknown. Therefore we also describe the mechanism of Na+ transport and hormonal regulation of Cl- transport in the ATL.

Involvement of prostaglandin E2 synthesis in the intestinal secretory action of Escherichia coli heat-stable enterotoxin II

The prostaglandin response of mouse intestinal epithelial cells after exposure to Escherichia coli heat-stable enterotoxin II was examined. The quantity of prostaglandin E2 produced by the intestinal cells was directly related to the dose of heat-stable enterotoxin II. The change in the amount of prostaglandin E2 over time correlated to that of the volume of fluid released into the intestinal lumen. We then demonstrated that administration of heat-stable enterotoxin II into the intestinal loops of mice induced elevation of arachidonic acid and phosphatidic acid levels in intestinal epithelial cells. These results show that heat-stable enterotoxin II stimulates arachidonic acid metabolism in intestinal epithelial cells and that the synthesized prostaglandin E2 functions as a mediator of fluid secretion induced by this enterotoxin.