Current status of renal replacement therapy in Japan: results of the annual survey of the Japanese Society for Dialysis Therapy

Beginning in 1966, the Patient Registration Committee of the Japanese Society for Dialysis Therapy has conducted a survey once a year on renal replacement therapy in Japan. As of 1983, the survey covered the life/death of patients in the survey years, as well as the case mix of individual patients. In 1990 several laboratory variables were added to the survey items. The present report summarizes the data from the 1993 and 1994 surveys. The Committee mailed out questionnaire forms at the end of the survey year to the heads of all dialysis facilities. Survey forms were returned from 99.6% of the dialysis facilities in the 1993 survey, and from 99.8% of the facilities in the 1994 survey. Some 143709 patients were treated by renal replacement therapy in 1994 (7509 were treated by CAPD, and 131016 by extracorporeal haemopurification). The gross mortality rate was 9.5% in the same year. The mean values of the laboratory variables among 88693 patients undergoing thrice weekly haemodialysis were as follows in 1993: Kt/V, 1.31 +/- 0.30; protein catabolic rate, 1.04 +/- 0.30 g/kg/day; haemodialysis time, 4.12 +/- 0.50 h. In 1994, the variables were: predialysis serum creatinine concentration, 11.54 +/- 2.85 mg/dl; predialysis serum albumin concentration, 3.91 +/- 0.55 g/dl; predialysis haematocrit, 28.69 +/- 4.36%.

Chloroquine induces basophilic differentiation of HL-60 cells

Many agents have been known to induce the differentiation of HL-60 cells. However, only a small number of reports on the basophilic differentiation of this cell line are known. In this study we show that the exposure of HL-60 cells to chloroquine induces to differentiate into basophils. This chloroquine-induced change suggests that the increase in intracellular pH and the upregulation of p21 with subsequent downregulation of cdc2 kinase are triggers for basophilic differentiation of this cell line.

B cell malignancy and hepatitis C virus infection

Italian authors report that hepatitis C virus (HCV) infection may be one of the causes of lymphoid malignancy such as non-Hodgkin's lymphoma (NHL) and Waldenström's macroglobulinemia (WM). To assess the relationship between HCV infection and B cell malignancy (BCM) in Japan, we analyzed HCV-RNA in 50 patients with BCM [25 cases of NHL, 4 of WM and 21 of multiple myeloma (MM)] and determined genotype of infected HCV(Okamoto's classification) using reverse transcription-polymerase chain reaction assay. Eight (16.0%) of 50 patients with BCM were HCV-RNA positive [HCV(+)], while no patients were HCV(+) in control group (18 patients of non-B cell NHL). Numbers of HCV(+) cases in each group examined were as follows; four (16.0%) in B cell NHL (genotype II/III/IV were 3/1/0, respectively), one (25.0%) in WM (genotype III) and three (14.3%) in MM (genotype II/III/IV were 1/1/1, respectively). All patients examined had no symptoms and signs suggesting vasculitis. The incidence of HCV infection in the patients with BCM was markedly higher than that (approximately 1%) of healthy blood donors in Japan. We also experienced four B cell NHL cases with splenic or hepatic origin in the course of chronic hepatitis C. These results implicate the association between persistent HCV infection and the occurrence of BCM.

Secretory production of erythropoietin and the extracellular domain of the erythropoietin receptor by Bacillus brevis: affinity purification and characterization

Bacillus brevis secretes a large amount of cell wall proteins into the culture medium. For construction of Bacillus brevis expression-secretion vectors of human erythropoietin (EPO) and the extracellular domain of mouse erythropoietin receptor (sEPOR), cDNA for each mature form was inserted into a plasmid containing the promoter region and the signal-peptide encoding region of a cell wall protein. Culture supernatants of transformants were affinity purified using a monoclonal antibody-fixed gel for EPO and and EPO-fixed gel for sEPOR. The affinity purification efficiently removed unwanted proteins, giving samples with sufficiently high purity to analyze amino acid sequences of N-terminal regions and biological activities. Combination of this secretory production and affinity purification may facilitate isolation of a large amount of pure EPO and sEPOR, and is useful for further understanding the molecular mechanism of interaction between EPO and EPOR.

Structural changes of immunoglobulin G oligosaccharides with age in healthy human serum

Age-related changes of IgG N-linked oligosaccharides isolated from normal human serum are reported for 403 individuals (male 227 and female 176), varying in age from 0 to 85 years. The IgG N-linked oligosaccharides were released from the protein by digestion with a glycoamidase and reductively aminated with the fluorescent reagent, 2-aminopyridine. The mixture of pyridylaminated oligosaccharides was separated at high resolution by HPLC using a reverse-phase column. From the results of neutral oligosaccharide analysis, agalactosyl glycoform and bisecting GlcNAc-containing glycoform were shown to increase with increasing age. Spearman's correlation coefficients were 0.503 and 0.473, respectively. Thus, in healthy people, an increase of both types of glycoforms correlates weakly with age. In addition, differences were demonstrated between male and female groups in their twenties. The quantity of agalactosyl glycoform was found to be lower in females than in males. No significant differences, however, were observed in the quantity of bisecting GlcNAc-containing glycoforms between males and females.

[Experience in treatment of patients with locally advanced or recurrent breast cancer: intraarterial infusion chemotherapy combined with radiotherapy]

For the purpose of local control and breast conservation, intraarterial infusion chemotherapy combined with radiotherapy has been indicated in patients with locally advanced breast cancer both in primary and recurrent cases. The present series, evaluated during the past 4 years, consisted of 15 patients 35-83 years of age, with invasive ductal carcinoma, including 10 with primary breast cancer (stage IIIb: 1; IV: 9) and 5 with postoperative recurrence (stage IIIb: 2, IV: 3). Intraarterial chemotherapy is started, basically infusing ADM 50 mg, MMC 10 mg and CDDP 50 mg into the internal thoracic and/or subclavian artery 1-3 times, followed by reduction surgery (quadrantectomy: 4, wide resection: 2) and radiotherapy to the breast, supraclavicular, parasternal and cervical regions according to tumor extent. Local response after arterial infusion was CR: 2, PR: 10, NC: 3 (response rate: 73%). The response rate of distant metastases after arterial infusion was 73%. Of 10 patients with primary breast cancer, recurrence was noted in 1. Breast conservation was successful in 8 of 10 patients. One of them, in stage IIIb, has survived for 4.5 years with no evidence of disease and with breast conservation. Five patients with postoperative recurrence showed CR with no recurrence after intraarterial chemotherapy and radiotherapy. Acute skin reaction occurred in 6 patients, and was especially frequent in patients with postoperative recurrence (4 of 5). According to these results, combined therapy affords breast conservation even in patients with locally advanced breast cancer, and improves patient's QOL in stage IV.

Relationship between serum carotenoid levels and cancer death rates in the residents, living in a rural area of Hokkaido, Japan

The relationship between serum carotenoid levels and cancer death in rural Japanese residents, aged more than 39 years, was examined epidemiologically. The follow-up subjects participated in the comprehensive health examinations, every August from 1986 to 1989, were 929 males and 1424 females, living in a rural area of Hokkaido, Japan. During 2-8 years to December 1994, the ninety-eight deaths were observed among the cohort; that is, deaths from all causes were 67 males and 31 females, and cancer deaths were 34 males and 10 females. Serum samples at fasting were collected at the entry of the cohort and serum levels of beta-carotene, alpha-carotene and lycopene were measured by the HPLC method. The relation between the mortality rates and serum carotenoid levels was estimated statistically using the Cox's proportional hazard model. The results were as follows; the hazard ratio with the overall on high serum beta-carotene levels to those of lower was 0.46 (95% C.I.: 0.27-0.78) for all causes and 0.33 (95% C.I.: 0.14-0.75) for cancer deaths. This result suggested that high levels of serum beta-carotene may play some roles on preventing cancer death.

Insulin-like growth factors and insulin stimulate erythropoietin production in primary cultured astrocytes

Erythropoietin (EPO) is established as a major regulator of erythropoiesis. However, we and others have shown that neurons express erythropoietin receptor (EPO-R), that astrocytes produce EPO and that EPO may act as a neurotrophic factor in the CNS. We also found that EPO production is activated by insulin and insulin-like growth factors (IGFs) in astrocytes in a dose-dependent manner and that IGF-I was the most potent activator. The concentrations required for half-maximal activation were 3 nM IGF-I, 10 nM IGF-II and 100 nM insulin. The oxygen concentration regulates EPO production; hypoxia stimulates EPO production in astrocytes. The stimulatory effect of IGFs and insulin on EPO production in astrocytes was not affected by the oxygen concentration of astrocyte culture. Insulin and IGFs did not increase the total protein synthesis of astrocytes but increased EPO mRNA levels, indicating that EPO production is stimulated at the mRNA level. It appeared that the growth factor-induced accumulation of EPO mRNA in astrocytes was caused by activation of the tyrosine kinase-signal transduction pathway, because tyrosine phosphorylation of receptors for IGF-I and insulin was activated when astrocytes were stimulated by these growth factors.

Erythropoietin receptor is expressed in rat hippocampal and cerebral cortical neurons, and erythropoietin prevents in vitro glutamate-induced neuronal death

Recently, erythropoietin has been shown to be produced by astrocytes and its production is hypoxia-inducible. In the present study, we demonstrated, using a reverse transcription-polymerase chain reaction assay and immunostaining of the cells, that the erythropoietin receptor was expressed in cultured hippocampal and cerebral cortical neurons of day 19 rat embryo. Erythropoietin protected the cultured neurons from glutamate neurotoxicity. Neurons cultured for seven to 10 days were exposed to glutamate for 15 min and after culture for a further 24 h in the absence of glutamate the neuron survival was assayed. Significant protection was observed with erythropoietin from 3 pM (c. 100 pg/ml) in a dose-dependent manner. The protection was completely reversed by co-application of a soluble erythropoietin receptor, an extracellular domain capable of binding with erythropoietin. For exhibition of the neuroprotective effect, exposure of neurons to erythropoietin approximately 8 h prior to exposure to glutamate was required. Experiments with the inhibitors indicated that RNA and protein syntheses were necessary for the protection. However, exposure to erythropoietin for a short period (5 min or less) was sufficient to elicit the protective effect. The protective effect of erythropoietin was blocked by the simultaneous addition of EGTA. These findings and the previous finding that erythropoietin induces a rapid and transient increase in intracellular Ca2+ concentration in neuronal cells suggest that erythropoietin plays a neuroprotective role in brain injury caused by hypoxia or ischemia and that erythropoietin-induced Ca2+ influx from outside of the cells is a critical initial event yielding an enhanced resistance of the neurons to glutamate toxicity.

Identification of casoxin C, an ileum-contracting peptide derived from bovine kappa-casein, as an agonist for C3a receptors

Casoxin C (Tyr-Ile-Pro-Ile-Gln-Tyr-Val-Leu-Ser-Arg) is a bioactive peptide that was isolated from a tryptic digest of bovine kappa-casein as an anti-opioid peptide in longitudinal strips of guinea pig ileum. Casoxin C also evokes contraction of the ileal strips, and we found that this process was biphasic with rapid and slow components. The contractile profile was very similar to that of human complement C3a(70-77), which is the COOH-terminal octapeptide of C3a and has, although less potent, qualitatively the same biological activities as C3a. Casoxin C also has homology with C3a(70-77). The rapid contraction was mediated by histamine release and the slow contraction was mediated by a prostaglandin E2-like substance, judging from the effects of various pharmacological inhibitors and antagonists on the ileal contraction. Casoxin C had affinity for C3a receptors (IC50 = 40 microM) in the radioreceptor assay. In addition, casoxin C showed phagocyte-stimulating activities. Casoxin C is therefore the first milk-derived peptide identified, that acts through complement C3a receptors.

In vitro neurotoxicity of amyloid β-peptide cross-linked by transglutaminase

Transglutaminase catalyzes the intermolecular cross-linking of peptides between Gln and Lys residues, forming an ε-(γ-glutamyl) lysine bond. Amyloid β-peptide, a major constituent of the deposits in Alzheimer disease, contains Lys16, Lys28, and Gln15 which may act as substrates of transglutaminase. Transglutaminase treatment of amyloid β-peptide (1-28) and amyloid β-peptide (1-40) yielded cross-linked oligomers. Transglutaminase-treated Aβ retarded neurite extension of PC12 cells, and rat cultured neurons of hippocampus and septum, brain areas severely affected by Alzheimer disease, and subsequently caused cell death, whereas the transglutaminase-untreated counterparts did not show harmful effects. The transglutaminase-catalyzed oligomers of amyloid β-peptide and their neurotoxicity may be involved in two characteristics in Alzheimer disease, neuronal degeneration and formation of the insoluble deposits.

ABBREVIATIONS

AD - Alzheimer disease, Aβ - amyloid β-peptide, DMEM - Dulbecco's modified Eagle's medium, DMEM/F-12-1:1 mixture of DMEM and Ham's F-12 medium, FCS - fetal calf serum, HS - horse serum, PAGE - polyacrylamide gel electrophoresis, MTT - 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, NGF - nerve growth factor, TGase - transglutaminase.

Analysis of catalytic action of transglutaminase induced in human promyelocytic leukemia (HL-60) and human hepatoblastoma (HepG2) cells

Transglutaminase is a calcium-dependent enzyme that catalyzes an amine incorporation and a cross-linking of proteins. Intracellular transglutaminase is induced when human promyelocytic leukemia HL-60 cells are treated with retinoic acid and human hepatoblastoma HepG2 cells, with interleukin-6. To find whether the intracellular reaction catalyzed by transglutaminase increased when the enzyme is induced in these cells, the transglutaminase-catalyzed incorporation of 14C-labeled methylamine into cellular proteins was measured. The incorporation level of the labeled methylamine into proteins of HL-60 and HepG2 cells did not increase after the transglutaminase had been induced. The presence of the calcium ionophore A23187 did not affect these results. These findings suggested that even after the enzyme induction the catalytic action of intracellular transglutaminase is maintained at a constant level in these cells by unknown regulatory mechanism(s).

Erythropoietin in mouse avascular yolk sacs is increased by retinoic acid

Erythropoiesis begins first in the visceral yolk sac (VYS) of the embryo; however, the involvement of erythropoietin (EPO) in yolk-sac erythropoiesis has not been studied adequately. This study reports the expression of EPO in normal and hypoxic VYSs and alterations in yolk sac components induced by retinoic acid (RA) in mice. Gravid mice (plug day = day 0 of gestation) were given one oral dose of 60 mg/kg of RA in olive oil on days 6, 6.5, 7, 7.5, or 8 of gestation and were sacrificed 2.5, 3, or 3.5 days later. Control mice received olive oil without RA. None of the dams developed anemia, but more than 80% of the embryos of the dams that received RA on day 6, 6.5, or 7 of gestation had avascular yolk sacs (AVYs) and anemia. In these AVYs, the adenosine triphosphate (ATP) level was as low as 18-59% of that in the control VYSs. Reverse transcription-polymerase chain reaction and Southern analysis of products demonstrated that mRNA for EPO receptor (EPR) was expressed in both VYSs and AVYs on days 9-11 of gestation, and EPO mRNA was present in VYSs and AVYs on days 9 and 10 of gestation and in vehicle-exposed VYSs on day 11 of gestation. Furthermore, enzyme immunoassay of EPO indicated that AVYs contained more EPO protein than control VYSs. Light microscopy revealed that, in AVYs, in addition to the defective hemopoietic cells, the endodermal layer was exclusively altered: The presence of focal proliferated regions and the separation from the mesenchyme led to a single layer from which some immature cells seemed to be migrating. Immunolocalization of EPO showed its presence in all components of VYSs with a characteristic distribution pattern: In the endodermal layer, cells with positive EPO staining decreased as gestation advanced, and erythroid precursor cells showed positive staining. In AVYs, the proliferated endodermal cells had EPO in abundance; in the separated regions, the distinction between positive and negative EPO staining became clearer than that in the control VYSs, and the immature cells in the lumens also had EPO. EPR was seen on the cell surface of the corresponding cells that reacted to EPO. These findings suggest that VYSs not only produce EPO temporarily but also respond to the oxygen content in situ. EPO and EPR appear to be synthesized in the endodermal cells of the VYSs that are likely to respond to the circumstances induced by RA.

[Microvessel count and vascular endothelial growth factor in renal cell carcinoma]

BACKGROUND

Angiogenesis plays an important role in the growth of solid tumors. The objective of this study is to investigate the relationship between microvessel density and mRNA measurement for vascular endothelial growth factor (VEGF) as well as the kinase domain receptor (KDR) in renal cell carcinoma (RCC).

METHODS

From 1992 to 1994, expression of mRNAs of VEFG, KDR and microvessel count by Factor VIII immunohistochemical staining were examined in 22 cases of RCC.

RESULTS

Northern blot hybridization demonstrated that 18 tumors (82%) expressed a higher level of VEGF gene than corresponding normal renal tissues (T/N > 1) and that the expression of VEGF gene in the tumors correlated well with that of KDR gene (r = 0.780, p = 0.001). Most of the tumor cells positively reacted to immunohistochemical staining for VEGF, but all of the normal renal tissue elements did not. RT-PCR analysis revealed that mRNAs of VEGF expressed in the tumors were of soluble subclasses. The mean number of microvessels (< 50 micrometers in diameter) in the tumors was 62.7 +/- 39.1/mm2 (range 13.7-133.1) and significantly correlated with the expression of VEGF gene (r = 0.636, p = 0.001).

CONCLUSIONS

The results indicate that RCC cells actively produce soluble VEGF and strongly suggest that VEGF and its receptor KDR cooperate to enhance the angiogenesis of this tumor.

Sensitivity and applicability of different methods for detection of terminal transferase in leukemia

The sensitivity of terminal deoxynucleotidyl transferase (TdT) assay methods was examined by using a mixture of the TdT-positive lymphoblastic leukemia cell line NALM-18 and the TdT-negative erythroleukemia cell line K-562. The biochemical assay could detect TdT activity in the mixture containing NALM-18 cells at concentrations of more than 10 percent. The immunofluorescent (IF) method could detect positive cells in the mixture containing NALM-18 cells at concentrations of more than 1 percent. Furthermore, an approximately 10(5)-fold increase in sensitivity was obtained by the combination of RT-PCR and subsequent Southern blotting, as compared to biochemical assay. In many leukemia cases the expression of TdT-mRNA corresponded well to that of TdT protein. However, in some patients with leukemia, only TdT-mRNA was detectable by RT-PCR without any expression of TdT protein. A PCR-based technique enables us to detect TdT transcripts at the highest sensitivity, but does not allow the characterization of each positive cell. IF analysis is simple and sensitive, but may sometimes cause nonspecific reactions. All these techniques have some advantages and some faults, therefore, the results obtained from clinical studies using these techniques should be interpreted with caution.

Anti-erythropoietin receptor monoclonal antibody: epitope mapping, quantification of the soluble receptor, and detection of the solubilized transmembrane receptor and the receptor-expressing cells

A hybridoma cell line producing the monoclonal antibody against erythropoietin receptor (EpoR) was established using the soluble ectodomain of mouse erythropoietin receptor (sEpoR) as an antigen. The monoclonal antibody termed 1G3 bound to the denatured sEpoR. Epitope mapping with peptide library revealed that 1G3 recognized the amino terminal region including the hexapeptide (positions 6 to 11; LeuProAspProLysPhe). The amino acid sequence in this hexapeptide was identical in mice, rats, and humans, and therefore 1G3 bound to EpoR from all of these sources. Using 1G3, we evaluated sEpoR by a sandwich enzyme-linked immunoassay, and EpoR in the solubilized membrane preparation was detected by Western blotting. The cells expressing EpoR were identified with immunochemical staining. We confirmed the presence of EpoR in a neuronal cell line and PC12 cells, and EpoR was expressed in primary cultured hippocampal neurons.

[Prognostic importance of prostate specific antigen in patients with hormonally treated stage D2 prostate carcinoma]

BACKGROUND

The objective of this study is to evaluate the relationship between PSA value and prognosis of the patients with stage D2 prostate carcinoma.

METHODS

Serum prostate specific antigen was analyzed in 61 patients with stage D2 prostate carcinoma submitted to hormone therapy.

RESULTS

The median values of PSA parameters were 77.6 ng/ml for the initial PSA, 91.8% for the maximal decrease, 2.7 ng/ml for the nadir, 1.1 months for the half-time time, 3.0 months for the time to nadir, 3.2 months for the doubling time after progression and 0.39 for the ratio of antemortem versus initial PSA. The median biochemical progression-free time was 15.0 months and the median actuarial survival after progression was 24.9 months. The progression-free time was significantly correlated with the normalization of PSA (p < 0.001) and the initial PSA of less than 100 ng/ml (p < 0.05), and the survival time after progression was significantly correlated with the doubling time (p < 0.05). The normalization of PSA was affected by initial value, maximal decrease rate and half-life time of PSA respectively, but not by the histological grade of the primary tumors. The doubling time was not correlated with these factors nor with the progression-free time.

CONCLUSION

The results show that the initial value, nadir level and doubling time of PSA can be used as prognostic parameters for prostatic carcinoma. Both the low ratio of premortem versus initial PSA, which may reflect an increase of stem cell fraction, and the PSA doubling time after relapse, which seems similar to or shorter than that of untreated cases, will indicate an aggressive potential of hormone-refractory tumors.

Measurement of airborne mite allergen exposure in individual subjects

To evaluate the extent of personal exposure to airborne mite allergens, subjects were asked to carry a personal air sampler when in their houses. The level of Der 1 allergen trapped by the sampler was measured with a highly sensitive immunoassay. There were great variations in airborne Der 1 exposure in each subject. When used bedding was replaced with new allergen-free bedding, we detected a decrease in the allergen level. The use of new bedding seems to be an effective measure for reducing airborne mite allergen exposure.