Superconductivity in 5d transition metal Laves phase SrIr2

We report here the superconducting properties of a Laves phase superconductor SrIr₂, which has a cubic MgCu₂ structure. SrIr₂ is a type-II superconductor, with a T _c of 5.9 K. The estimated superconducting parameters of lower critical field µ ₀ H _c1 and upper critical field µ ₀ H _c2, coherence length ξ(0), penetration depth λ(0) and Ginzburg-Landau (GL) parameter κ(0) are approximately µ ₀ H _c1  =  101 Oe, µ ₀ H _c2(0)  =  5.9 T, ξ(0)  =  7.47 nm, λ(0)  =  237 nm, and κ(0)  =  31.7, respectively. The specific-heat data indicate that SrIr₂ is a strong-coupling superconductor because the value of ΔC/γT _c is approximately 1.71, which is larger than the value of 1.43 that is expected from the BCS theory. The physical properties obtained in this study are explained well by theoretical calculations including spin-orbit coupling (SOC). This result indicates that the physical properties of SrIr₂ are strongly affected by the presence of SOC.

Inhibition of Bach1 ameliorates indomethacin-induced intestinal injury in mice

BTB and CNC homolog 1 (Bach1) is a transcriptional repressor of heme oxygenase-1 (HO-1). It plays an important role in the feedback regulation of HO-1 expression, which protects cells from various insults including oxidative stress and inflammatory cytokines. However, the role of Bach1 in intestinal inflammation remains unclear. In this study, the role of Bach1 in intestinal mucosal injury was elucidated using 8-week-old female C57BL/6 (wild-type) and homozygous Bach1-deficient C57BL/6 mice. Intestinal mucosal injuries induced by a single subcutaneous administration of indomethacin were evaluated macroscopically, histologically, and biochemically. Mucosal protein content and chemokine mRNA levels were determined by real-time PCR. Our results showed that the indomethacin-induced intestinal injury was remarkably improved in Bach1-deficient mice. Histological examination showed that the area of injured lesion was decreased in Bach1-deficient mice compared to wild-type mice. Administration of indomethacin induced expression of inflammatory chemokines such as KC, MIP1alpha and MCP1, which was suppressed in Bach1-deficient mice. Myeloperoxidase activity in the intestinal mucosa was also significantly decreased in Bach1-deficient mice. Additionally, Bach1 deficiency enhanced immunopositivity of HO-1 in the intestinal mucosa after indomethacin administration. Disruption of the Bach1 gene thus caused inhibition of mucosal injury, indicating that inhibition of Bach1 may be a novel therapeutic strategy for treating indomethacin-induced intestinal injury.

Phase II: Combination of cladribine, cyclophosphamide, mitoxantrone, rituximab (R-CCM) in patients with relapsed and refractory follicular and mantle cell lymphoma, results of a prospective study at Kitasato University

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Background: Indolent non-Hodgkin’s lymphoma (I-NHL) account for 20% of all of NHL in Japan, and they are increasing in number. More than 80% of the patients who achieve a complete remission with the initial treatment, will require salvage therapy. Recently, cladribine (2-CdA), a purine analogue is receiving much attention, because, even as a single agent, it has shown a high efficacy for I-NHL. The aim of our study was to determine the effectiveness and toxicity of combined chemotherapy consisting of 2-CdA, cyclophosphamide (CYP), mitoxantrone (MIT), rituximab (R-CCM) in the treatment of refractory or relapsed I-NHL. Methods: Patient eligibility criteria were: Previously treated patients with I-NHL, refractory or relapsed disease, no chemotherapy or irradiation within 4 weeks prior to the study, life expectancy of at least 3 months, age: 20–75, perfomance status of 0–3, adequate function ( bone marrow, liver, kidney, lung, heart) and written informed consent. The treatment regimen was: 2-CdA given at a dose of 0.09 mg/kg/day in a 2-h intravenous infusion from day 2–4, CYP 200 mg/m2/day from day 2–4, MIT 8 mg/m2/day on day 2 and rituximab 375 mg/m2/day on day .Primary end point was overall response rate. Results: 9 patients were enrolled, 7 (2 with mantle cell lymphoma, MCL; and 5 with follicular lymphoma, FL) were eligible. Mean Age was 63(51–72). The mean observation time was 121 days(47–314). Overall response rate (complete and partial) just after this therapy was 85.7%, one was progressive disease. One of PR one relapsed and died ten months after this regimen. The major toxicity was myelosuppression. Grade-III and -IV neutropenia was seen in 7 patients, grade-III thrombocytopenia in one and grade-III hemorrhagic cystitis in one, but all of them recovered from these toxicity. After the treatment, Grade-IV pneumonia and grade-III left-ventricular diastolic dysfunction was seen in the PD patient and passed away. Conclusions: the R-CCM is effective and safe in a combined regimen for relapsed and refractory I-NHL patients. We have just begun this new regimen, therefore, further investigations with larger population are warranted.

No significant financial relationships to disclose.

DHMEQ, a new NF-κB inhibitor, induces apoptosis and enhances fludarabine effects on chronic lymphocytic leukemia cells

Chronic lymphocytic leukemia (CLL) is a low-grade lymphoid malignancy incurable with conventional modalities of chemotherapy. Strong and constitutive nuclear factor kappa B (NF-kappaB) activation is a characteristic of CLL cells. We examined the effects of a new NF-kappaB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), on CLL cells. Dehydroxymethylepoxyquinomicin completely abrogated constitutive NF-kappaB activity and induced apoptosis of CLL cells. Apoptosis induced by DHMEQ was accompanied by downregulation of NF-kappaB-dependent antiapoptotic genes: c-IAP, Bfl-1, Bcl-X(L) and c-FLIP. Dehydroxymethylepoxyquinomicin also inhibited NF-kappaB induced by CD40 and enhanced fludarabine-mediated apoptosis of CLL cells. Results of this study suggest that inhibition of constitutive and inducible NF-kappaB by DHMEQ in combination with fludarabine is a promising strategy for the treatment of CLL.

Homogenous simultaneous detection of HCV RNA and internal control by two-color fluorescence real-time monitoring of isothermal sequence amplification with INAF probes

We demonstrated the homogenous simultaneous detection of HCV RNA and internal control by two-color fluorescence real-time monitoring of isothermal sequence amplification with INAF probes.

Primary gastric T-cell lymphoma not associated with human T-lymphotropic virus type I: a case report and review of the literature

Primary gastric T-cell lymphoma (PGTL) not associated with human T-lymphotropic virus type I (HTLV-I) is extremely rare and such a case is reported herein. The patient was a 58-year-old Japanese male presenting with submucosal tumor of the stomach identified on endoscopic examination. The lesion was diagnosed as non-Hodgkin's lymphoma by endoscopic biopsy and classified as peripheral T-cell lymphoma, unspecified, due to clonal rearrangement of the T-cell receptor beta (TCR) gene and expression of TCR beta protein in the absence of B-cell genotypes and phenotypes. Unlike previously reported cases of HTLV-I-unassociated PGTL, lymphoma in the current case was characterized histologically as "low grade" and phenotypically as CD4+, TIA-1+, granzyme B+, and CD103-. The lymphoma responded well to chemotherapy and radiation, and the patient was well with no detectable disease 10 months after initiation of therapy. A review of patients with PGTL in the literature revealed a few long-term survivors, and the investigation of therapeutic strategies for PGTL is, therefore, necessary.

White matter lesions and alteration of vascular cell composition in the brain of spontaneously hypertensive rats

There have been few studies on the white matter lesions of spontaneously hypertensive rats (SHR). From the point of view of hypertension and arteriosclerosis, white matter lesions were examined in SHR and stroke-prone SHR (SHRSP), and were then compared with Wistar-Kyoto (WKY) rats. The vasculopathy was analyzed by morphometric immunohistochemistry for collagen and smooth muscle actin. Both SHR and SHRSP had hypertension at > or = 12 weeks of age, and the latter developed severe white matter lesions at 20 weeks. Immuno- histochemistry revealed proliferation of microglia in the white matter and an increase in smooth muscle actin in the vessels of SHRSP compared with the WKY rats and SHR, but there were no changes in the collagen. These results indicate a role of hypertension in the pathogenesis of white matter lesions. However, genetic difference may also be responsible since SHR and SHRSP showed similar hypertension.

[Role of ultrasonography in diagnosis of neutropenic enteritis: a study of 4 cases]

Neutropenic enteritis is a septic or inflammatory disease of the colon. It is usually encountered in patients with hematological malignancy who have undergone chemotherapy, and it presents as fever, diarrhea, and abdominal pain, although the symptoms are not always specific. The diagnostic features of neutropenic enteritis revealed by barium enema, CT and ultrasonography have been reported previously. Here we report 4 cases of neutropenic enteritis in which ultrasound was used for diagnosis, and also for monitoring the clinical course of the disease. Because neutropenic enteritis is rapidly progressive, early diagnosis and therapeutic intervention are required. We believe that ultrasonography is a useful method for examining patients with neutropenic enteritis, being noninvasive, mobile, and providing rapid results in real time, thus aiding early diagnosis and clinical follow-up.

Molecular cloning and sequencing of myosin light chains in human megakaryoblastic leukemia cells

Myosin light chain genes of hematopoietic cells have yet to be characterized. We cloned the full-length cDNAs of 20 kDa regulatory myosin light chain (MLC-2) and 17 kDa essential myosin light chain (MLC-3) from Meg-01, a human megakaryoblastic leukemia cell line. Both MLC-2 and MLC-3 gene are transcribed ubiquitously in various hematopoietic cells. The MLC-2 open reading frame of 516 nucleotides encoding a protein of 172 residues was detected in cloned cDNA of 967 nucleotides. The Ca2+-binding domain and five phosphorylation sites were highly conserved. The deduced amino acid sequence has a 99.4% and 100% homology with that of human fetus brain and human lymphocyte, respectively. The MLC-3 open reading frame of 453 nucleotides encoding a protein of 151 residues was detected in cloned cDNA of 742 nucleotide. The MLC-3 protein is 99.3% identical to that of human fibroblasts. These results suggest that hematopoietic myosin light chain proteins are similar to those of other nonmuscle cells and smooth muscle, thus differing from skeletal and cardiac muscles.

Frequent expression of the variant CD30 in human malignant myeloid and lymphoid neoplasms

We earlier identified a variant of CD30 (CD30v) that retains only the cytoplasmic region of the authentic CD30. This variant is expressed in alveolar macrophages. CD30v can activate the nuclear factor-kappaB (NF-kappaB) as CD30, and its overexpression in HL-60 induced a differentiated phenotype. To better understand the physiological and pathological functions of CD30v, expression of this variant was examined using a multiple approach to examine 238 samples of human malignant myeloid and lymphoid neoplasms. Screening by reverse transcriptase-polymerase chain reaction (RT-PCR) revealed expression of CD30v transcripts in 52 of 72, 7 of 11, 63 of 90, and 7 of 30 samples of acute myeloid leukemia (AML), myeloid blast crisis of myeloproliferative disorders (MBC), and lymphoproliferative disorders (LPDs) of B- and T-cell origin, respectively. CD30v expression was high in monocyte-oriented AMLs (FAB M4 and M5), B-cell chronic lymphocytic leukemia (B-CLL), and multiple myeloma (MM). Using the specific antibody HCD30C2, prepared using a peptide corresponding to the nine amino acids of the amino-terminal CD30v, expression of CD30v protein was detected in 10 of 25 and 2 of 10 AML and ALL samples, respectively. In AMLs, immunocytochemical detection of CD30v revealed the presence of loose clusters of CD30v-expressing cells dispersed amid a population of CD30v-negative blasts. Finally, the parallel expression of CD30v mRNA and protein, as evidenced by Northern and Western blotting, was confirmed in selected cases of AMLs and LPDs. A significant correlation was found between expressions of CD30v and CD30 ligand transcripts in AML and LPD (P = 0.02, odds ratio = 3.2). The association of CD30v with signal-transducing proteins, tumor necrosis factor receptor-associated factor (TRAF) 2, and TRAF5 was demonstrated by coimmunoprecipitation analysis, as was demonstrated for authentic CD30 protein. Expression of transcripts for TRAF1, TRAF2, TRAF3, and TRAF5, as demonstrated by RT-PCR, was noted in leukemic blasts that express CD30v. Collectively, frequent expression of CD30v along with TRAF proteins in human neoplastic cells of myeloid and lymphoid origin provide supportive evidence for biological and possible pathological functions of this protein in the growth and differentiation of a variety of myeloid and lymphoid cells.

Primary gastric T-cell lymphomas: report of two cases and a review of the literature

To understand more fully the clinicopathological features of primary gastric T-cell lymphomas (PGTL), we report two cases of PGTL and review the literature. The present cases were not associated with human T-cell leukemia virus type 1 (HTLV-1) and were at clinical stage IIE. In both cases, T-cell origin of the lymphoma cells was diagnosed immunohistochemically. The clinical courses of these two cases were different: one followed a very aggressive clinical course and the patient died 6 months after the diagnosis, whereas the other patient survived more than 2 years without adjuvant chemotherapy. Clinicopathological features of 23 patients with PGTL are summarized with regard to their differences from primary small intestinal T-cell lymphomas (PSITL) and by association with HTLV-1. The median age at onset of PGTL was 58 years. The gender ratio was male-dominant (M:F = 2.3:1). About two-thirds (10 of 17) of PGTL cases had evidence of HTLV-1 infection. The most common presenting symptom for PGTL was upper abdominal discomfort and/or pain (76%), whereas that in PSITL was weight loss (61%) and diarrhea (42%). Typical lesions for PGTL were large ulcerations at the corpus to antrum. Neoplastic cells had no typical morphological characteristics for PGTL including HTLV-1-associated cases. CD3+4+8- was the most frequently observed surface phenotype of PGTL cells. Laboratory findings at diagnosis were not informative. Most patients were treated by gastrectomy with or without chemotherapy. PGTL, excluding that with HTLV-1, showed better prognosis than PSITL, although PGTL with HTLV-1 had a poorer prognosis.

CD30: expression and function in health and disease

CD30 was originally described as a marker of Hodgkin's and Reed-Sternberg cells in Hodgkin's lymphoma. Cloning and characterization of cDNAs encoding CD30 and its ligand (CD30L) established these proteins as members of the tumor necrosis factor receptor (TNFR) and tumor necrosis factor (TNF) superfamilies, respectively. Expression of CD30 is mostly restricted to virus-infected lymphocytes, neoplasms of lymphoid origin and a subset of activated T cells which produce Th2-type cytokines. The ligand is present on activated T cells, resting B cells, granulocytes, and the medulla of the thymus (epithelial cells and Hassal's corpuscles) as well as in various leukemia cells. The biological function of CD30 is pleiotropic but has come to be understood in the context of co-stimulatory signals. Signal transduction of CD30 utilizes signal transducers, TNFR-associated factors (TRAF1, 2, 3 and 5), which are shared by other TNFR family members. Mechanisms of signal transduction leading to diverse biological functions remain to be elucidated.

Evaluation of thrombopoiesis in thrombocytopenic disorders by simultaneous measurement of reticulated platelets of whole blood and serum thrombopoietin concentrations

To evaluate thrombopoiesis in thrombocytopenic disorders, we simultaneously determined reticulated platelet counts in whole blood by FACScan flow cytometry and serum thrombopoietin (TPO) concentrations by a sensitive sandwich ELISA. The subjects were 40 healthy volunteers and 45 thrombocytopenic patients. In idiopathic thrombocytopenic purpura (ITP), the percentage of reticulated platelets was significantly elevated (5.61 +/- 2.02%: mean +/- SD) relative to normal controls (2.17 +/- 0.90%), but serum TPO concentrations (1.91 +/- 1.27 fmol/l) did not differ significantly from the normal range (1.43 +/- 0.62 fmol/l). The patients with aplastic anemia (AA) had decreased reticulated platelet counts and markedly increased serum TPO concentrations (13.65 +/- 10.64 fmol/l). In thrombocytopenic patients with liver cirrhosis (LC), the absolute number of reticulated platelets (1.65 +/- 1.11 x 10(9)/l) decreased similarly that in AA. However, serum TPO concentrations (1.38 +/- 0.50 fmol/l) did not increase in contrast to AA. Our findings suggested a possible dual mechanism of thrombocytopenia in LC; that is, thrombocytopenia in LC results from the decreased TPO production primarily in the liver adding to an increase in platelet sequestration in the spleen.

A novel domain in the CD30 cytoplasmic tail mediates NFkappaB activation

About 100 amino acid residues in the C-terminal region are conserved among human, rat and murine CD30, a member of the tumor necrosis factor receptor (TNFR) superfamily, and can be separated into three subdomains with relatively higher conservation (D1, D2 and D3). Activation of NFkappaB by CD30 was shown to be mediated through interaction of TNFR-associated factor (TRAF) 1, 2 and 5 with the D2 and D3 subdomains. However, the function of the other conserved subdomain, D1, remained to be determined. Deletion of the D2 and D3 subdomains abolished interactions with TRAF2 and 5 but it did not affect NFkappaB activation. Reporter gene assays using deletion and mutant constructs of CD30 revealed that the D1 subdomain is sufficient for NFkappaB activation, without interaction with TRAF2 or 5, and that each subdomain alone can activate NFkappaB. Electrophoretic mobility shift assays revealed constitutive and CD30-induced NFkappaB activation in stable transformants of 293 cells expressing CD30 or a deletion mutant lacking D2 and D3 subdomains. Deletion of C-terminal 19 amino acid residues of the D1 subdomain abolished activation of NFkappaB. Substitution of alanine for one of the two threonine residues (amino acid position 524 and 529), one of which is a potential phosphorylation site in the D1 subdomain, also abolished the NFkappaB activation. Overexpression of the TRAF domain of TRAF2 or 5 had a dominant negative effect on the NFkappaB activation mediated by the D1 subdomain, thereby suggesting involvement of TRAF proteins in the signaling. Thus, the C-terminal 100 amino acid region of CD30 is composed of three independent functional subdomains, two of which contain binding sites for TRAF proteins. A novel domain in the cytoplasmic tail mediates NFkappaB activation, without direct interaction of TRAF2 or 5. Our observations suggest involvement of an unknown TRAF protein(s) in the signal transduction pathway of CD30.

F1 alpha: a novel mucin antigen associated with gastric carcinogenesis

In a previous study, we obtained a novel monoclonal antibody (F1 alpha-75) directed against a synthetic mucin antigen termed F1 alpha, and demonstrated that this antigen was expressed in a high percentage (80.2%; 89/111) of gastric carcinomas. In the present study, we compared the expression of F1 alpha with that of sialyl-Tn antigen, a mucin antigen similar to F1 alpha, in 54 human early gastric carcinomas, intestinal metaplasia and adenomatous polyps of the stomach to determine how differences in the expression of these antigens correlated with gastric carcinogenesis. The rate of expression of F1 alpha in early gastric carcinoma tissues, 81.5%, was higher than that of sialyl-Tn antigen, 57.4%. No correlation was found between the rate of expression and histological type, depth of cancerous invasion or lymph node metastasis. Sialyl-Tn antigen was extensively expressed in 77.5% of specimens of complete intestinal metaplasia and in 78.6% of those of incomplete intestinal metaplasia; however, the expression of F1 alpha in those specimens was rare and sporadic, with rates of only 25.0 and 27.7%, respectively. In adenomatous polyps, the rate of expression of F1 alpha is 6.25% and that of sialyl-Tn antigen is 43.8%. Our findings indicate that F1 alpha is a more specific antigen for gastric cancer than sialyl-Tn antigen, and that F1 alpha is an antigen associated with carcinogenesis of the stomach.

Tumor necrosis factor receptor-associated factor (TRAF) 5 and TRAF2 are involved in CD30-mediated NFkappaB activation

Signals emanated from CD30 can activate the nuclear factor kappaB (NFkappaB). The two conserved subdomains, D1 and D2, in the C-terminal cytoplasmic region of CD30 were tested for interaction with two tumor necrosis factor receptor-associated factor (TRAF) proteins with NFkappaB activating capacity, TRAF2 and TRAF5. TRAF5 is the newest member of the TRAF family that binds to lymphotoxin beta receptor and CD40. TRAF5, as well as TRAF2, interacted with the D2 subdomain of CD30 in vitro and in vivo. Deletion analysis by the yeast two-hybrid system revealed that the C-terminal 22 and 30 amino acid residues are dispensable for interaction of TRAF5 and TRAF2 with CD30, respectively. Substitution of alanine for threonine at 463 abolished the interaction with TRAF2. Overexpression of the TRAF domain of TRAF2 or TRAF5 showed a dominant negative effect on CD30-mediated NFkappaB activation. Simultaneous expression of these TRAF domains further suppressed the NFkappaB activation, suggesting an interplay of these TRAF proteins. Expression of TRAF2 and TRAF5 mRNA was demonstrated in T- and B-cell lines that express CD30. Taken together, our results indicate that TRAF2 and TRAF5 directly interact with CD30 and are involved in NFkappaB activation by CD30 signaling.

Cloning and characterization of a cDNA for rat CD30 homolog and chromosomal assignment of the genomic gene

CD30 is a member of the tumor necrosis factor receptor superfamily, which is expressed on some activated lymphocytes, virus-infected cells and transformed lymphocytes. To facilitate our understanding of biological functions and functional domains, we isolated rat cDNA clones encoding the rat homolog of human CD30 from a cDNA library of a rat T-cell line, TARL-2. The nucleotide sequence of the cDNA showed 73% homology with that of human CD30. The deduced rat CD30 protein consisted of 493 amino acids with an M(r) of 59 160 and contained a single transmembrane domain. It lacked the second repeat of the cysteine-rich motif in the extracellular domain found in human CD30. The amino acid sequence showed 51.8 and 61.2% identity with the cysteine-rich and the cytoplasmic domains, respectively. In the cytoplasmic domain, however, the amino acid sequence was highly conserved in about 100 residues near the C-terminus showing 77.7% identity, whereas the rest of the cytoplasmic domain showed 45.2% identity. This conservation suggests the functional importance of this region. Comparison with the recently reported mouse CD30 revealed 83.7% conservation of the amino acid sequence and a common structure of the extracellular domain which lacks the second cysteine-rich motif. Northern blots revealed a 3.4-kb mRNA in the PHA-activated spleen cells and human T-cell leukemia virus type 1 (HTLV-1)-infected rat T-cell lines, whereas smaller transcripts of 2.3 kb were found in the lung. A rabbit polyclonal antibody raised against GST-fusion protein of the cytoplasmic domain detected bands with an apparent M(r) of 80 kDa and 100- 110 kDa expressed in TARL-2 and spleen cells. Transient overexpression of rat CD30 in TARL-2 cells activated HIV LTR in a NF-kappa B site-dependent manner, indicating that CD30 signals activate NF-kappa B. The chromosomal location of the gene was identified by fluorescence in situ hybridisation at 5q36.2, and appeared to correspond to human 1p36, where human CD30 has been mapped. The identification and characterization of the rat counterpart of human CD30 will facilitate studies of the biological function of this molecule.

A variant CD30 protein lacking extracellular and transmembrane domains is induced in HL-60 by tetradecanoylphorbol acetate and is expressed in alveolar macrophages

We identified and cloned cDNAs for two novel CD30 mRNAs of 2.3 kb that are induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) in the human myeloid leukemia cell line HL-60. These transcripts were transcribed from the intronic region just upstream of the exon coding for the transmembrane domain of the CD30 protein. The shorter cDNA had a deletion of 54 nucleotides corresponding to the 3' region of the transmembrane domain of the CD30 and which was probably caused by alternative splicing. Translation of these transcripts appeared to start from the internal methionine codon at nucleotide position 289 that corresponds to that of 1612 in the CD30 cDNA, and encode a protein of 132 amino acid residues which corresponds exactly to the C-terminal cytoplasmic domain of CD30 protein. The calculated molecular mass of this variant CD30 (CD30v) protein was 14,087. Thus, the predicted CD30v protein retains most of the cytoplasmic region, but lacks the extracellular and transmembrane domains. Northern blots detected the expression of CD30v transcripts only in the lung and the TPA-stimulated HL-60 cell line. Translation of this mRNA in vitro produced a protein of 25 kD. Immunoblotting analysis with HCD30C1, a rabbit polyclonal antibody raised against the cytoplasmic domain of CD30 protein, detected proteins with an apparent Mr 25 kD expressed in TPA-stimulated HL-60 and COS-7 cells that were transfected with both types of CD30v cDNAs. Constitutive phosphorylation of the CD30v protein was demonstrated by in vitro labeling with [32P]. Immunohistochemical studies demonstrated CD30v protein was in alveolar macrophages. Cotransfection experiments using a kappa B-site-dependent reporter construct showed that CD30v can transactivate gene expression through activation of NF kappa B, as was noted on the authentic CD30 protein. Overexpression of the CD30v induced differentiation of HL-60 cells as evidenced by an increased NBT reduction activity. These observations provided new insights into the molecular heterogeneity and biological function of CD30 in myeloid cells.

Alterations in gastric mucin with malignant transformation: novel pathway for mucin synthesis

BACKGROUND

Mucins are high-molecular-weight glycoproteins produced by both normal and cancer cells. However, in cancer cells, abnormal mucins are synthesized and potentially can be used as markers for the development and progression of certain malignancies. In a previous study, we reported the production of a new monoclonal antibody directed against a mucin antigen termed F1 alpha, an O-linked oligosaccharide similar to sialyl Tn and Thomsen-Friedenreich (T) antigens, that has not been previously detected in human cancers. F1 alpha is expressed in a high percentage (80.2%; 89/111) of gastric cancers.

PURPOSE

In the present study, we compared the expression of F1 alpha with that of sialyl Tn and T antigens in human gastric cancer tissues to determine how differences in the expression of these cancer-associated antigens correlated with the biological properties of cancer cells.

METHODS

A total of 141 cases of gastric cancer were studied. Sections of formalin-fixed, paraffin-embedded tissue were immunostained for F1 alpha, sialyl Tn, and T antigens. The relationship between the expression of these antigens and the patient's clinicopathologic characteristics was studied. The chi-square test (two-sided) was used for statistical analyses.

RESULTS

F1 alpha was expressed in a high percentage of the cases of early to advanced cancers, irrespective of the degree of malignant progression. The rate of expression of sialyl Tn antigen in early carcinoma was low, but it increased significantly as depth of invasion increased (P < .05) and was significantly higher in patients with hepatic or lymph node metastasis than in those without such metastasis (P < .01). Expression of T antigen significantly increased with depth of invasion (P < .01) and was significantly higher in patients with hepatic metastasis (P < .05), lymph node metastasis (P < .05), or peritoneal dissemination (P < .01) than in those without such metastasis or dissemination. In consecutive sections of the same specimen, the sites of staining for F1 alpha and sialyl Tn antigens seldom coincided. In many cases, F1 alpha staining was predominant, but the sialyl Tn-dominant region tended to increase as gastric cancer progressed. Regions of T-antigen staining were usually circumscribed by those of F1 alpha staining.

CONCLUSION

Our findings indicate that the expression of F1 alpha begins almost at the same time as does carcinogenesis in gastric epithelial cells. Moreover, in association with progression of gastric carcinoma, synthetic pathways for sialyl Tn antigen and T antigen probably are activated independently.

Synthesis of neoglycolipids containing a mucin-type core unit

The unnatural glycolipids O-beta-D-galactopyranosyl-(1-->4)-O-(2-acetamido- 2-deoxy-beta-D-glucopyranosyl)-(1-->3)-O-(2-acetamido-2-deoxy-alpha-D- galactopyranosyl)-(1-->1)-ceramide (1), O-beta-D-galactopyranosyl-(1-->4)-O-(2-acetamido-2-deoxy-beta-D-glucopyr anosyl) - (1-->6)-O-(2-acetamido-2-deoxy-alpha-D-galactopyranosyl)-(1-->1)-ceramid e (2), and O-beta-D-galactopyranosyl-(1-->4)-O-(2-acetamido-2-deoxy-beta-D- glucopyranosyl)-(1-->3)-O-[O-beta-D-galactopyranosyl-(1-->4)-(2-acetamid o-2- deoxy-beta-D-glucopyranosyl)-(1-->6)]-O-(2-acetamido-2-deoxy-alpha-D- galactopyranosyl)-(1-->1)-ceramide (3), and their beta-(1-->1)-linked isomers, were synthesized. The precursor oligosaccharides for 1, 2, and 3 were made by coupling O-2,3,4,6- tetra-O-acetyl-beta-D-galactopyranosyl)-(1-->4)-3,6-di-O-acetyl-2- deoxy-2-phthalimido-alpha,beta-D-glucopyranosyl trichloroacetimidate with tert-butyldiphenylsilyl 2-azido-4,6-O-benzylidene-2-deoxy-beta-D-galactopyranoside, tert-butyldiphenylsilyl 2-azido-3-O-benzoyl-2-deoxy-beta-D-galactopyranoside, and tert-butyl-diphenylsilyl O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1-->4)-O-(3,6-di-O-a cetyl-2 - deoxy-2-phthalimido-beta-D-glucopyranosyl)-(1-->3)-2-azido-2-deoxy-beta- D- galactopyranoside, respectively. These oligosaccharides were converted into their trichloroacetimidates, which were coupled with 3,2'-di-O-benzoyl ceramide. Deprotection of the coupling products gave the title compounds 1, 2, and 3.

High expression of the CD30 molecule in human decidual cells

CD30 is a receptor-type membrane protein that belongs to the nerve growth receptor superfamily. It is expressed on Hodgkin's cells and activated lymphocytes, as well as in some human malignancies including malignant lymphomas, embryonal carcinomas, and other mesenchymal tumors. However, whether it is expressed in normal tissues remains unclear. To study the expression and biological function of CD30, we first examined various human tissues by immunohistochemistry. The monoclonal antibody Ber-H2 intensely stained the membranes of decidual and endometrial cells with decidual change in frozen sections. Western blots of these tissues with Ber-H2 revealed bands of 120, 105, and 90 kd as found on CD30-expressing cells. Northern blots of these tissues using a CD30 cDNA probe detected mRNAs of the same molecular mass and variety as those in the positive control cell line HUT 102. These results indicated that CD30 is expressed in human endometrial tissue with decidual change and imply that CD30 expression in endometrial tissue is induced by hormonal control.

A new cancer-associated antigen defined by a monoclonal antibody against a synthetic carbohydrate chain

Carbohydrate antigens can be designed by referring to previously defined carbohydrate structures. We have generated a novel monoclonal antibody (MAb) (F1 alpha-75) against an artificially designed antigen (F1 alpha), using organic-synthetic chemistry methods and hybridoma technology. F1 alpha (Gal beta 1-->4GlcNAc beta 1-->6GalNAc alpha 1-->Ser/Thr) belongs to core type 6 of O-linked glycans, which has not been previously reported in human cancers. To produce antibodies against F1 alpha, a glycolipid was synthesized which carries the carbohydrate portion of F1 alpha on a ceramide foundation (Gal beta 1-->4GlcNAc beta 1-->6GalNAc alpha 1-->Cer). The MAbs we obtained (F1 alpha-75, F1 alpha-87) specifically recognized F1 alpha and had only a very weak or no cross-reactivity with other glycolipids similar to F1 alpha. We investigated the expression of F1 alpha in human tissues, including 110 gastric cancers, 73 colon cancers and 42 pancreatic cancers. F1 alpha was found in human cancerous tissues but not in normal adult tissues. The rate of positive staining with F1 alpha-75 was 80.0% for gastric cancer, 52.4% for pancreatic cancer and 38.4% for colon cancer. F1 alpha-75 also reacted with the tissues neighboring gastric and pancreatic tumors but not intensely. Among fetal tissues, F1 alpha-75 reacted with the pyloric glands of the stomach, the centro-acinar cells of the pancreas, the convoluted tubules of the kidney and the terminal bronchioles of the lung.

Intralymphocytic free calcium and magnesium in stroke-prone spontaneously hypertensive rats and effects of blood pressure and various antihypertensive agents

1. Free Ca2+ ([Ca2+]i) and Mg2+ ([Mg2+]i) were measured in peripheral lymphocytes from stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar-Kyoto rats (WKY) at the age of 5, 7 and 17 weeks, from various antihypertensive agents-treated SHRSP, and from secondary hypertensive WKY. 2. At the age of 5 weeks, no difference was observed in systolic blood pressure (SBP), or lymphocyte [Ca2+]i and [Mg2+]i between SHRSP and WKY. At the age of 7 or 17 weeks, SBP and [Ca2+]i of SHRSP were significantly higher than in WKY, and at the age of 17 weeks, [Mg2+]i of SHRSP was significantly lower than in WKY. Further, [Ca2+]i or [Mg2+]i was positively or negatively correlated to SBP, and [Mg2+]i was negatively correlated to [Ca2+]i. 3. SBP of SHRSP fell significantly after antihypertensive treatment with calcium antagonist, angiotensin-converting enzyme (ACE) inhibitor or hydralazine for 40 days. [Ca2+]i was significantly lower in calcium antagonist and hydralazine groups, and tended to be low in ACE inhibitor group. These four groups showed no difference in [Mg2+]i. 4. After 40-day administration of NG-nitro-L-arginine (L-NNA), WKY developed severe hypertension, but there were no significant differences in lymphocyte [Ca2+]i and [Mg2+]i between the L-NNA treated and non-treated groups. 5. These results suggested that increased lymphocyte [Ca2+]i and decreased [Mg2+]i observed in SHRSP are not only secondary to hypertension but possibly related to a basic genetic abnormality of divalent cation handling.

Cerebrovascular protection by sequential bilateral carotid artery ligation in aged spontaneously hypertensive rats

1. Sequential bilateral carotid artery ligation (BCL) separated by a 1 week interval was performed on 5 month spontaneously hypertensive rats (SHR) (i.e. SHRSR-B1/Izm) and the developmental course of hypertension and cerebrovascular lesions in advanced age were analysed as compared with those in age-matched sham-operated controls. 2. Behavioural activity and behavioural reaction to light were also investigated in the above-mentioned SHR, young and adult stroke-prone SHR (i.e. SHRSP-A3/Izm), SHR (i.e. B1/Izm) and Wistar-Kyoto rats (i.e. WKY/Izm). 3. All of the control SHR developed severe hypertension resulting in cerebral stroke with focal oedema due to cerebral haemorrhage and infarction as a result of arterionecrosis 18 months after birth. 4. SHR usually die within a few days of BCL. In the present study, however, they successfully survived without cerebrovascular damage for a long time, although they developed a similar severe hypertension in a significantly shorter period of time (P < 0.05) and showed behavioural abnormalities that were probably due to severe cerebral ischaemia. 5. These experimental results suggest an ischaemic tolerance phenomenon in a hypertensive model that was exposed to mild ischaemic stress by unilateral carotid artery ligation (UCL) before the subsequent induction of severe ischaemia by BCL. The results also suggest that an aggravation of hypertensive cerebrovascular changes due to long-lasting ischaemia after BCL was prevented through a possible cumulative effect of ischaemic stress.

Potassium accelerates urinary sodium excretion during salt loading without stimulating atrial natriuretic polypeptide secretion

1. Effects of potassium (K) supplementation (100 mEq/day) on urinary sodium (Na) excretion and on the secretion of atrial natriuretic polypeptide (ANP) during salt loading (350 mEq/day) were studied in 12 healthy salt-resistant normotensives under strictly controlled metabolic ward conditions. 2. Urinary volume and Na excretion on the first day of the high salt period (HSP) were significantly greater in the K-supplemented group (KG) than in the control group (CG). 3. There was a significant gain in bodyweight after salt loading in both groups, with a significantly greater gain in CG on the second day of HSP. Haematocrit decreased significantly during salt loading in both groups, the degree of which was significantly greater in CG. 4. Plasma norepinephrine decreased significantly during salt loading in both groups, the degree of which was significantly less in KG than in CG. A significant increase in plasma ANP was observed in CG on and after the second day of HSP, while a significant increase in plasma ANP was observed on the fifth day of HSP in KG. 5. These findings indicate that K supplementation accelerates diuresis and natriuresis, resulting in moderate suppression of volume expansion induced by salt loading and that this accelerated diuresis and natriuresis is not a result of the action of ANP.

International cooperative study on the relationship between dietary factors and blood pressure: a preliminary report from the Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. The CARDIAC Cooperative Study Research Group

1. To investigate the epidemiological relationship of dietary factors to blood pressure (BP) and major cardiovascular diseases, we carried out the international cooperative Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study, which so far involves 48 centers in 20 countries as of August 1991. From each population, 100 men and 100 women aged 50-54 years were randomly selected for BP measurement, 24-h urine collection, blood tests, and medical interview. Various biological markers of diets from urine and blood were analyzed centrally in the Izumo CARDIAC center. 2. Cross center analysis using simple linear regression revealed strong significant correlations of body mass index (BMI) to systolic BP (SBP; p < 0.01) and diastolic BP (DBP; p < 0.001) in men. 24-h urinary sodium (Na) excretion in men also showed significant correlations with SBP (p < 0.05) and DBP p < 0.05) even after controlling for the effect of BMI (SBP; p < 0.05, DBP; p < 0.05). 3. Within center analysis using multiple linear regression implied that BMI and Na strongly adversely affect BP, whereas magnesium may have beneficial influence on BP. 4. Multicolinearities among 24h urinary sodium, calcium, and urea nitrogen were noted in men.

[Acute leukemia successfully treated with natural interferon-alpha]

Natural interferon-alpha (IFN-alpha) alone was administered to a 42-year-old man with acute leukemia, whose bone marrow revealed hypocellularity (NCC = 6 X 10(4)/microliters) and a 50% increase in blasts. Initial chemotherapy regimens, including BHAC-DMP or low dose Ara-C were ineffective. One month after starting nIFN-alpha therapy, the blasts in his bone marrow decreased below 3% and peripheral blood cell counts became normal. He has been in remission for at least 7 months.

Aggravating effects of isolated caging on the development of hypertension and its complications in stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto rats (WKY)

Stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar-Kyoto rats (WKY) were maintained in isolation or in group to analyze the effect of isolation, one type of emotional stress, on the development of hypertension and its complications. SHRSP kept isolated during the whole or a half of the experimental period developed severer hypertension within a shorter period than those kept together with other animals throughout the experiment, and showed significantly higher incidences of cerebral stroke (40 or 33%) than the latter (8.3%). Histological and pathophysiological studies revealed pituitary-adrenal and cardiac hypertrophy accompanying more accelerated urinary epinephrine (E) excretion which indicated emotional stress caused by isolation might aggravate pathological lesions in hypertension. Neither WKY in isolation nor in groups developed hypertension, although isolated WKY had significantly heavier pituitary and adrenal glands accompanied with more accelerated urinary E and calcium excretions than WKY kept in groups.

Effects of long-term cerebral ischemia caused by bilateral carotid artery ligation on the acceleration or the development of hypertension in spontaneously hypertensive rats (SHR) or Wistar-Kyoto rats (WKY)

Bilateral carotid artery ligation (BCL) was performed with one week interval between the each operation in male spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) aged 4 months. BP rose immediately after unilateral carotid artery ligation (UCL) and BCL in both WKY and SHR due to carotid sinus reflex. Once returning to preoperative levels after both UCL and BCL, BP of SHR and WKY increased again gradually one and 4 months after BCL and thereafter, respectively. BP was significantly higher than that in the controls of each strain, and the BP increment was significantly greater in SHR than in WKY. A significant regional cerebral blood flow (rCBF) increase on the contralateral side of carotid ligation was observed in SHR in contrast to a little change in that of WKY and a reduction of rCBF after BCL was significantly greater in SHR than in WKY. Behavioral activities in SHR were also reduced after BCL. Cerebral edema with nerve cells damage was recognized in SHR. In contrast, little change was found in WKY. On the other hand, upper cervical sympathectomy attenuated convulsive seizures after BCL more markedly in SHR, which survived longer than non-denervated SHR. These results suggest that chronic mild cerebral ischemia caused by BCL with one week interval accelerates the development of severe hypertension in SHR and developed mild hypertension in WKY. Sympathetic innervation might play much more important role in collateral circulation through the vertebrobasilar system in SHR.

Stroke-prone SHR (SHRSP) as a model for osteoporosis

Since previous studies on SHRSP showed various abnormalities in Ca metabolism, aged SHRSP together with age-matched Wistar-Kyoto (WKY) were examined for bone mineral density and contents as well as bone histomorphometry and mechanical properties. SHRSP and WKY, 10 rats of each group at the age of 7 to 8 months were sacrificed with or without tetracycline and calcein labellings for the estimation of mineral appositional rate. Both femurs, tibia and the 1st lumbar vertebra were extirpated from each rat; one femur was used for mineral density and content analyses and the other was used for analyzing mechanical properties by three point-bending and torque methods (Maruto, MZ500D). Mineral density and cortical thickness index were decreased significantly in SHRSP compared with WKY, and Ca contents were decreased as well. Correspondingly femurs from SHRSP were proven to be fragile in the maximum bending stress. Undecalcified histological sections of tibial proximal epiphysis histomorphometrically indicated bone volume and trabecular thickness were significantly decreased in SHRSP. These findings together with others indicate SHRSP can be a good model for spontaneous osteoporosis in man.

Relative frequencies of dementia of the Alzheimer type and vascular dementia in Japanese nursing homes

We have studied neuropathologically 200 aged nursing home residents (101 men and 99 women) autopsied between 1976 and 1985. Seventy-three of the 200 showed dementia during life, that is, 27% and 55% of the residents in nursing homes and special nursing homes, respectively. The relative frequencies of SDAT and VD in nursing homes as a whole were the same (34%). The relative frequencies of SDAT and VD in special nursing homes, where usually high concentrations of VD have been noted, were 21% and 52%, respectively. A comparison of the results of our special nursing homes (SDAT:VD = 1:2.5) and nursing homes as a whole (SDAT:VD = 1:1) with those of Barnes and Raskind (SDAT:VD = 2:1) and Rovner et al. (SDAT:VD = 3:1) showed that the frequencies of VD in Japanese nursing homes are considerably higher than those in their American counterparts.

Stroke-prone spontaneously hypertensive rats as a model for toxemia of pregnancy and aggravating and preventive effects of maternal modifications during pregnancy on offspring's growth

Genetical differences in changes in blood pressure (BP) were chronologically investigated during pregnancy in stroke-prone spontaneously hypertensive rats (SHRSP), Wistar-Kyoto rats (WKY) and Sprague-Dawley (SD) rats. Especially, the early stages were carefully studied. Maternal conditions in SHRSP were modified by the treatments with NaCl and taurine, respectively. BP in SHRSP and WKY rose significantly at the early stage of pregnancy compared to prepregnancy levels (SHRSP; 208 +/- 2 mmHg vs 197 +/- 5 mmHg, WKY; 133 +/- 2 mmHg vs 126 +/- 1 mmHg) (p less than 0.05). In contrast, no such changes were observed in SD rats. Differences in 24-hour urinary epinephrine excretion before and during pregnancy ran parallel with such BP changes among these strains. NaCl-loaded SHRSP died during pregnancy with severe pathohistological changes in their kidneys and severe proteinuria. Taurine treatment had a marked prophylactic effect on these maternal pathological changes during pregnancy, resulting in better growth in offsprings. These results suggest that SHRSP could be one of the suitable animal models for the studies on toxemia of pregnancy and also suggest an important role of hypertensive genetical disposition in the development of toxemia of pregnancy.

A new view of the arterial smooth muscle cells and autonomic nerve plexus by scanning electron microscopy in spontaneously hypertensive rats

Mesenteric artery smooth muscle cells and their associated autonomic nerve plexus were simultaneously studied by scanning electron microscopy in 3-month-old spontaneously hypertensive rats. The adventitial surface of the outermost muscle layer revealed numerically more protrusions accompanied by a denser network of nerve fibers in spontaneously hypertensive rats vs normotensive Wistar-Kyoto rats.

A new approach to the prevention of hypertensive cardiovascular diseases by controlling the proliferation of vascular smooth muscle cells

Cholera toxin subunit B suppressed the proliferation of cultured vascular smooth muscle cells from the thoracic aorta of Wistar-Kyoto rats (WKY), stroke-resistant spontaneously hypertensive rats (SHR) and stroke-prone SHR (SHRSP). Since cholera toxin subunit B did not stimulate cyclic AMP accumulation in vascular smooth muscle cells, the effect of cholera toxin subunit B might be due to another mechanism. Cholera toxin subunit B bound to the surface of vascular smooth muscle cells and was rapidly incorporated into them. The morphological structure of vascular smooth muscle cells was transformed from the synthetic type to the non-synthetic type, in which microfilaments and intermediate filaments were abundantly formed, while rough endoplasmic reticulum was decreased after CTB treatment.

Effects of low-dose chronic diltiazem treatment on hemodynamic changes in spontaneously hypertensive rats

The effects of long-term diltiazem treatment on hemodynamic and cardiovascular characteristics were investigated in young spontaneously hypertensive rats (SHR), Wistar-Kyoto rats (WKY) and their respective untreated controls. The drug was administered to treated rats over a period of 24 weeks. Body weight, left ventricular weight, mean arterial pressure (MAP), heart rate, max dp/dt or maximum velocity of the contractile element (Vmax) were not significantly different in diltiazem-treated SHR and untreated SHR. In diltiazem-treated SHR, cardiac index (CI) and stroke volume index (SI) were significantly increased and total peripheral resistance and the index of left ventricular compliance (delta P/delta V) were significantly decreased compared with untreated SHR. Left ventricular pumping ability in treated SHR was higher than that in untreated SHR, despite the low dose of diltiazem given. However, there was no significant difference between treated and untreated WKY. Long-term diltiazem treatment did not affect left ventricular function or biochemical properties in SHR and WKY. These data suggest that long-term diltiazem treatment improves pump function in SHR without changing blood pressure.

Effects of sulphur amino acids on the development of hypertension and atherosclerosis in stroke-prone spontaneously hypertensive rats

We investigated the effects on blood pressure of 5% taurine administered prenatally or postnatally via maternal parents in stroke-prone spontaneously hypertensive rats (SHRSP). Prenatal and/or postnatal administration of taurine produced a blood pressure reduction in the offspring until at least 3 months of age. Furthermore, offspring exposed to high concentrations of taurine through the placenta during the prenatal period and also for 1 month after birth via maternal milk, showed a greater reduction in blood pressure than the group given taurine prenatally but not postnatally. The stroke-prone SHR were fed a high-fat cholesterol and low-protein diet containing 1% methionine or with 3% lysine in drinking water, and effects of the dietary amino acids on the development of atherogenesis were investigated. Intake of additional 1% methionine or 3% lysine had marked preventive effects on atherogenesis in the cerebral and mesenteric arteries in SHRSP. Therefore, early dietary intake of sulphur amino acids delays the onset of hypertension and attenuates the development of both severe hypertension and atherosclerosis in SHRSP.

Effect of milk protein and fat intake on blood pressure and the incidence of cerebrovascular diseases in stroke-prone spontaneously hypertensive rats (SHRSP)

The intake of two milk protein-rich diets containing casein and whey protein attenuated the development of severe hypertension in stroke-prone spontaneously hypertensive rats (SHRSP), and extended their life span in comparison with SHRSP on a regular stock diet. Milk fat-rich diet intake reduced the incidence of cerebrovascular disease in SHRSP without a significant fall in blood pressure. These results suggest that certain milk components have a preventive effect on hypertension and cerebrovascular disease in SHRSP.

Catecholamine-induced polyploidization in vascular smooth muscle cells

Polyploidy formation of vascular smooth muscle cells was observed in vivo by intravenous infusion of norepinephrine or epinephrine in Wistar-Crea rats for 12 days at the rate of 0.02 mumol/hr with an osmotic minipump and in vitro by exposing cultured vascular smooth muscle cells obtained from normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) to norepinephrine (10(-7)M to 10(-5)M) in the cultured medium. Infusion in vivo of norepinephrine but not epinephrine increased blood pressure slightly. However, both agents increased significantly the frequency of tetraploidy of smooth muscle cells up to 14.9 +/- 0.6% (mean +/- SE) and 9.2 +/- 0.5% compared with saline (6.5 +/- 0.7%). Exposure in vitro to norepinephrine (10(-6)M) increased the frequency of tetraploidy and octaploidy of smooth muscle cells from SHR up to 14.2% and 2.1%, respectively, compared with nonexposed cells (8.1% and 0.2%). These results appear to indicate that norepinephrine and epinephrine induce polyploidy of smooth muscle cells independently from blood pressure elevation.

Dietary prevention of stroke and its mechanisms in stroke-prone spontaneously hypertensive rats--preventive effect of dietary fibre and palmitoleic acid

Previously it was reported that dietary protein, some amino acids and potassium are effective in preventing stroke in stroke-prone spontaneously hypertensive rats (SHRSP). The present study revealed that other dietary factors could also prevent cerebral lesions, and the mechanism of this effect was studied. In SHRSP given 1% NaCl in their drinking water, a diet containing 10% active fibre (powdered brown seaweed converted to K+ form) significantly lowered blood pressure (BP) and markedly reduced the incidence of stroke (0 versus 100% in controls on the 30th day of experiment). Since the faecal to urinary sodium (Na) excretion ratio was increased in this group and a similar increase in faecal Na content was noted in SHRSP given a diet containing 10% alginic acid, the inhibition of intestinal Na absorption by alginic acid in the seaweed fibre was considered to be a possible preventive mechanism. Among SHRSP given various fatty acids, a diet containing 1% palmitoleic acid (POA) significantly improved the survival rate, with concomitant reduction in the incidence of stroke in spite of their excess NaCl intake through 1% NaCl water for drinking. Since neither BP nor urinary Na excretion was changed by POA which had high affinity for the vascular wall, the preventive effect was ascribed to the possible direct metabolic improvement of vascular smooth muscle cells.