Increased Survival Benefit of Adjuvant Intra-arterial Infusion Chemotherapy in HCC Patients with Portal Vein Infiltration after Hepatectomy.

BACKGROUND: The role of adjuvant hepatic intra-arterial infusion chemotherapy (HAI) is considered to be a promising option. METHODS: We examined treatment effects of adjuvant HAI using cisplatin in 37 hepatocellular carcinoma (HCC) patients with portal vein infiltration (PVI) who underwent hepatectomy in comparison with those in 85 patients who did not. RESULTS: PVI in 89 patients. Increased levels of aspartate transaminase, tumor markers, size and microvessel tumor infiltration (MVI) or cirrhosis, poorly differentiation, non-adjuvant HAI was associated with lower overall survival (p = 0.09). Poor differentiation, MVI and HAI were independently risk factors associated with tumor-free and overall survivals by the multivariate analysis (p < 0.05). Adjuvant HAI tended to show longer survivals in comparison with no-HAI (p = 0.08) and the multivariate analysis revealed significant efficacy of HAI for better prognosis. CONCLUSION: Adjuvant HAI showed effectiveness on prolonging tumor-free and patient survival in HCC with PVI and is a promising option in the daily clinical practice.

Development of thymic lymphomas by oral administration of N-nitroso-N-propylurea and establishment of transplantable lines of thymic lymphoma in F344 rats.

Forty-eight female F344/DuCrj rats were given a 400-ppm solution of N-nitroso-N-propylurea (CAS: 816-57-9) continuously in their drinking water. Thymic lymphomas were induced most frequently (85%) followed by duodenal tumors (48%). Sixteen tumors were examined by the immunofluorescence inhibition test for murine leukemia virus-related antigens; 15 were negative and the other was weakly positive. Twenty-six tumors were intraperitoneally and subcutaneously transplanted syngeneically; 25 (96%) were successfully transplanted intraperitoneally and 24 (92%) subcutaneously. The serial intraperitoneal transplantation was continued, and 22 lines of transplantable lymphoma in an ascites form were established. In almost all tumor lines, tumor cells took in a high percentage of recipient rats and caused the death of the recipients within 12-23 days. The thymus, liver, spleen, greater omentum, and lymph nodes were frequently invaded by transplanted tumor cells. The tumor lines were considered to be of T-cell lineage.

Different expression of CD36 antigen molecule on the surface of megakaryocyte lineage leukemias and megakaryocyte leukemia cell lines MEG-01 and HEL.

Peripheral blood leukemic cells from four patients with peroxidase negative acute leukemia, which expressed neither myeloid nor lymphoid cell surface antigens, were analyzed by using monoclonal antibodies (MoAb) capable of recognizing megakaryocyte-platelet-related antigens. Leukemic cells from one case reacted with 5F1 MoAb, whereas cells from all the tested cases reacted with OKM5 MoAb, which belongs to the same CD group as 5F1 (CD36). Also, culture cells from megakaryoblastic leukemia cell line, MEG-01, and human erythroleukemia cell line, HEL, showed a different pattern of expression for the CD36 antigen molecule detected by 5F1 and OKM5 MoAb, individually. Furthermore, we have demonstrated that the epitopes recognized by 5F1 and OKM5 MoAb appear on the same CD36 molecule on the surface of HEL cells by means of the two-color analysis using FACS-IV. On the basis of our experiments, we conclude that, CD36 molecule, a receptor for TSP, is synthesized and expressed in at least two ways, inside the cells and on the surface of megakaryocyte lineage leukemias and megakaryocytic leukemia cell lines MEG-01 and HEL. This is strongly suggestive that thrombospondin (TSP)-mediated adhesion represents an alternative pathway for cytoadherence, and that CD36 expression on various kinds of cells may lack some essential modifications or components necessary for the TSP receptor activity.

No concomitant occurrence of the N-ras and p53 gene mutations in myelodysplastic syndromes.

Mutations of the N-ras oncogene and p53 tumor suppressor gene were simultaneously investigated in bone marrow cells from 44 patients with myelodysplastic syndrome (MDS) or MDS-derived leukemia by single-strand conformation polymorphism (SSCP) analysis followed by direct sequencing. The mutations of the N-ras gene were detected only in two cases with MDS-derived leukemia. Three patients with MDS-derived leukemia and one with refractory anemia with excess of blasts exhibited five mutations of the p53 gene. No concomitant mutations of both genes were observed in our study, suggesting that alterations of both genes could play an important role in the progression of MDS in a non-cooperative manner.

Genetic evidence of "American" and "European" type symbiotic algae of Paramecium bursaria Ehrenberg.

Paramecium bursaria is composed of a "host" ciliate and a "symbiont" green alga. Based upon physiology, DNA hybridization and virus infection, two types of symbionts, called "American" type and "European" type, have been reported to date. Here, we determined the 18S rDNA and internal transcribed spacer 2 (ITS2) regions for both "American" and "European" types. Sequence features clearly separated into two lineages; NC64A (USA), Syngen 2-3 (USA), Cs2 (Chinese), MRBG1 (Australian), and Japanese strains belong to the "American", whereas PB-SW1 (German) and CCAP 1660/11 (British) strains belong to the "European". In "American" 18S rDNA, three introns were inserted in the same positions as for previously described Japanese symbionts. In "European" 18S rDNA, a single intron occurred in a different position than in the "American". Between the types, sequence differences were seven or eight nucleotides (0.39 %) in the 18S rDNA exon, and more than 48 nucleotides (19.2 %) in ITS2 regions. We subsequently sequenced the host 18S rDNA. As a result, two groups: Cs2, MRBG1, and Japanese strains, and PB-SW1 and CCAP 1660/11 strains, were separated (with 23 substitutions and 4 insertions or deletions between the groups). The congruent separations between hosts and symbionts may imply that the type of symbiont depends on the host type.

Synthesis and antitumor evaluation in mice of certain 7-deazapurine (pyrrolo[2,3-d]pyrimidine) and 3-deazapurine (imidazo[4,5-c]pyridine) nucleosides structurally related to sulfenosine, sulfinosine, and sulfonosine.

7-Deaza (pyrrolo[2,3-d]pyrimidine) and 3-deaza (imidazo[4,5-c]pyridine) congeners of sulfenosine (5a and 9), sulfinosine (6a and 10), and sulfonosine (7a) have been prepared and evaluated for their antileukemic activity in mice. Amination of 2-amino-7-beta-D-ribofuranosylpyrrolo[2,3-d]pyrimidine-4(3H)-th ion e (4a) and its 2'-deoxy analogue (4c) with a chloramine solution gave the corresponding 4-sulfenamides (5a and 5c, respectively), which on selective oxidation with m-chloroperoxybenzoic acid (MCPBA) gave the respective diastereomeric 2-amino-7-beta-D-ribofuranosyl-pyrrolo[2,3-d]pyrimidine-4-sulfinamide (7-deazasulfinosine, 6a) and its 2'-deoxy derivative (6c). A similar amination of 7-(2-deoxy-beta-D-erythro-pentofuranosyl)pyrrolo[2,3-d]pyrimidine-4(3H)- thione (4b) gave the corresponding 4-sulfenamide derivative (5b). Oxidation of 5b with 1 molar equiv of MCPBA furnished (R,S)-7-(2-deoxy-beta-D-erythro-pentofuranosyl)pyrrolo[2,3-d]pyrimidine- 4- sulfinamide (6b), whereas use of excess of MCPBA afforded the corresponding sulfonamide derivative (7b). Treatment of 3-deaza-6-thioguanosine (8) with a chloramine solution gave 3-deazasulfenosine (6-amino-1-beta-D- ribofuranosylimidazo[4,5-c]pyridine-4-sulfenamide, 9). Controlled oxidation of 9 with MCPBA afforded 3-deazasulfinosine (10). As gauged by increases in the mean postinoculation life spans of L1210 inoculated mice, none of these nucleosides exhibited biologically significant activity (T/C greater than or equal to 125). Even so, antileukemic activity appeared to be influenced, albeit not uniformly, by structural modifications in the base and carbohydrate moieties of sulfenosine and sulfinosine. Thus, while several of the compounds were lacking in cytotoxic activity, eight others (4c, 5a, 5c, 6a, 6b, 7b, 9, and 10) were estimated to have reduced body burdens of viable L1210 cells by 16-77%.

Synthesis and in vivo antitumor activity of 2-amino-9H-purine-6-sulfenamide, -sulfinamide, and -sulfonamide and related purine ribonucleosides.

A number of 6-sulfenamide, 6-sulfinamide, and 6-sulfonamide derivatives of 2-aminopurine and certain related purine ribonucleosides have been synthesized and evaluated for antileukemic activity in mice. Amination of 6-mercaptopurine ribonucleoside (7a) and 6-thioguanosine (7b) with chloramine solution gave 9-beta-D-ribofuranosylpurine-6-sulfenamide (8a) and 2-amino-9-beta-D-ribofuranosylpurine-6-sulfenamide (sulfenosine, 8b), respectively. Selective oxidation of 8a and 8b with 3-chloroperoxybenzoic acid (MCPBA) gave (R,S)-9-beta-D-ribofuranosylpurine-6-sulfinamide (9a) and (R,S)-2-amino-9-beta-D-ribofuranosylpurine-6-sulfinamide (sulfinosine, 9b), respectively. However, oxidation of 8a and 8b with excess of MCPBA gave 9-beta-D-ribofuranosylpurine-6-sulfonamide (10a) and 2-amino-9-beta-D-ribofuranosylpurine-6-sulfonamide (sulfonosine, 10b), respectively. Similarly, amination of 5'-deoxy-6-thioguanosine (7c) afforded the 6-sulfenamide derivative (8c), which on controlled oxidation gave (R,S)-2-amino-9-(5-deoxy-beta-D-ribofuranosyl)purine-6-sulfinamide (9c) and the corresponding 6-sulfonamide derivative (10c). Treatment of 6-thioguanine (12) with aqueous chloramine solution gave 2-amino-9H-purine-6-sulfenamide (13). Oxidation of 13 with 1 molar equiv of MCPBA afforded (R,S)-2-amino-9H-purine-6-sulfinamide (14), whereas the use of 4 molar equiv of MCPBA furnished 2-amino-9H-purine-6-sulfonamide (15). The resolution of R and S diastereomers of sulfinosine (9b) was accomplished by HPLC techniques. The structures of (R)-9b and 10b were assigned by single-crystal X-ray diffraction studies. (R)-9b exists in the crystal structure in four crystallographically independent conformations. Of the 18 compounds evaluated, 13 exhibited very significant anti-L1210 activity in mice. Sulfenosine (8b) at 22 mg/kg per day X 1 showed a T/C of 170, whereas sulfinosine (9b) at 173 mg/kg per day X 1 showed a T/C of 167 against L1210 leukemia. The 5'-deoxy analogue of sulfinosine (9c) at 104 mg/kg per day also showed a T/C of 172. A single treatment with 8b, 9b, and 9c reduced body burdens of viable L1210 cells by more than 99.8%.

Effects of a titratable oral appliance on supine airway size in awake non-apneic individuals.

STUDY OBJECTIVES: To define morphological changes in the upper airway and its surrounding structures after the insertion of a titratable mandibular repositioner. DESIGN: Ten non-apneic adult males participated in this study. A set of supine lateral cephalograms was taken for each subject at the end of expiration with a titratable oral appliance in place in four mandibular positions: most retruded (RP), maximum protrusion (MAX), 33% of MAX (MAX33), and 67% of MAX (MAX67). Changes in the anteroposterior width of the upper airway, positions of the hyoid bone and the third cervical vertebra were compared between the four mandibular positions. An ANOVA was used to test for statistical significance. SETTING: N/A. PATIENTS OR PARTICIPANTS: N/A. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: The anteroposterior width of the velopharynx significantly increased when the mandible was advanced from RP to MAX67 and MAX. However, there were no significant changes in the anteroposterior width of the oropharynx. Significant forward displacement of the hyoid bone and third cervical vertebra together with the mandible was found in MAX67 and MAX compared to RP. CONCLUSION: Especially in MAX67 and MAX, the titratable oral appliance significantly enlarges upper airway size in the velopharynx and results in a forward displacement of the hyoid bone and the third cervical vertebra.

Flow cytometric analysis of peroxidase negative acute leukemias by monoclonal antibodies--II. Acute megakaryoblastic and acute pro-megakaryocytic leukemias.

In this report, we have described three cases of acute megakaryoblastic leukemia (AMKL) which were demonstrated by the presence of megakaryocyte-platelet-related cell-surface antigens detected by utilizing flow cytometry and monoclonal antibodies in addition to both PPO activity which was shown by ultrastructural cytochemistry and emergence of differentiation antigens while culturing these leukemic cells. The blasts of one case possessed both platelet GpIb and GpIIb/IIIa cell-surface antigens detected by 5F1 (CD36), AN51 (CDw42), and J15, P2 and HPL2 (CDw41), respectively, whereas the remaining two cases almost completely lacked Gp1b cell-surface antigen. Hence, the former was diagnosed as immature (pro) megakaryocytic leukemia and the latter as AMKL from the viewpoint of immunophenotypic analysis as discussed in this article.

Single- and multiple-dose pharmacokinetics of intravenous cefpirome (HR810) to healthy volunteers.

The safety and pharmacokinetics of single and multiple administrations of cefpirome (HR810), a new cephalosporin antibiotic agent with a broad antibacterial spectrum, were studied in healthy male volunteers. The single administration protocols included a 3-minute intravenous injection of 0.5 g or 1 g, and a 1-hour intravenous drip infusion of 0.5 g, 1 g, or 2 g. The multiple administration protocols included nine intravenous injections and 1-hour intravenous drip infusions of 1 g of cefpirome twice a day at intervals of 12 hours. Cefpirome was tolerated, and only a few mild, subjective and hepatic-function side effects were observed. There were no severe abnormalities. The drug concentrations in the plasma and the urine were determined by means of HPLC and bioassay, and the results correlated well (r = 0.99). The pharmacokinetic parameters were calculated using a two-compartment model. The elimination half-life (t1/2 beta) was about 1.7 hours for both intravenous injection and intravenous drip infusion and was not dose-dependent. AUC and Cmax were dose-dependent in this study, although an accumulation due to multiple administrations was not observed, and there were no changes in the pharmacokinetic parameters after the initial and the final administrations. The recovery rate of the unchanged compound in the urine was more than 80% in the 24 hours after a single administration and was the same after multiple administrations. Bioautography did not show any active metabolites in the plasma or the urine. The results, for safety and pharmacokinetics, show that cefpirome can be expected to have excellent clinical efficacy for bacterial infections.

Acute myelogenous leukemia with PIG-A gene mutation evolved from aplastic anemia-paroxysmal nocturnal hemoglobinuria syndrome.

We report a patient with aplastic anemia (AA)-paroxysmal nocturnal hemoglobinuria (PNH) syndrome who developed acute myelogenous leukemia (AML). Flow cytometric analysis showed that the leukemic cells in the bone marrow lacked CD59 antigen on their surface and were positive for P-glycoprotein. Heteroduplex and single-strand conformation polymorphism analysis followed by sequencing of the leukemic cells in the bone marrow disclosed 1 frameshift-type mutation in exon 2 of the phosphatidylinositol glycan-class A (PIG-A) gene, which deductively produces truncated PIG-A protein. These findings provide direct evidence that the leukemic cells evolved from the affected PNH clone. Cytogenetic analysis in the bone marrow in each stage of AA-PNH, AML, and at relapse of AML showed normal, -7, and -7 plus -20, respectively, showing evidence of a clonal evolution. Because complete remission of AML was not achieved by intensive chemotherapies, allogeneic peripheral blood stem cell transplantation (PBSCT) from the patient's HLA-matched sister was performed successfully with recovery of CD59 antigen on bone marrow hematopoietic cells; however, leukemia relapsed 4 months after PBSCT. Leukemia derived from PNH may be resistant to intensive chemotherapy, and a highly myeloablative regimen may be required for stem cell transplantation to eradicate the PNH-derived leukemia clone.

Effect of ubenimex (Bestatin) on the cell growth and phenotype of HL-60 and HL-60R cell lines: up-and down-regulation of CD13/aminopeptidase N.

Ubenimex (Bestatin), a low-molecular-mass dipeptide, has been demonstrated to have anti-tumor activities and immunomodulating activities. We here report cell growth inhibition and phenotypic changes of HL-60 and HL-60R cell lines induced by Bestatin treatment. Bestatin (0.1 microg/ml) showed remarkable cell growth inhibition against HL-60 cells, whereas it was ineffective for HL 60R cells. Bestatin also showed growth inhibition in the concentration of 1 microg/ml against HL-60R cells which are resistant to differentiation induction by DMSO and TPA. In both cell types, the effect of growth inhibition by Bestatin treatment was dose dependent. We found a low level expression of CD13 and a low number of CD13 positive cells in HL-60R cells compared with that of HL-60. We also observed phenotypic changes of HL-60 and HL-60R cells following incubation with Bestatin (10 microg/ml) for 1 and 3 hrs, respectively. With HL-60 cells, the upregulation of CD13/aminopeptidase N was found after 1 hr, however, the downregulation was observed after 3 hrs incubation with Bestatin. On the other hand, the downregulation of CD15 and CD33 was observed after both one and 3 hrs incubation. Similarly, in HL-60R cells, the upregulation of CD13/aminopeptidase N was found temporarily (1hr), and then CD13 downregulation was observed after 3 hrs incubation with Bestatin. No notable change was observed for expression of other myeloid-related antigens, e.g. CD14 (My4, LeuM3), CD11b (OKM1), and CD34 (My10). On the basis of these observations of in vitro activity, we suggest that Bestatin may also be an effective anti-leukemic agent in vivo.

Aggressive Diffuse Lymphoma Coexpressing NRAS p21 and C-erbB-2 (neu) Oncogene Products, and CALL A (CD 10).

We describe here a case of malignant lymphoma (ML) which coexpressed common acute lymphoblastic leukemia antigen (CALLA:CD10) and NRAS p21 and c-erbB-2 (neu) oncogene products. The patient, an 83 year-old man, had massive generalized lymphadenopathy and pleural effusions. Serum LDH levels were elevated to 801 IU/L. Surface phenotypes were analysed by a fluorescent-activated cell sorter with a panel of monoclonal antibodies (MAbs). The ML cells coexpressed antigens detected by MAbs CD10, CD19, CD20, CD22, CD24, CD38, Ia (HLA-DR), c-neu and surface immunoglobulin (Ig) G, Kappa. Gene rearrangements for the Ig JH and JK were found. Overexpression of NRAS p21 was shown by gene amplification using Southern blot analysis, while gene amplification of c-erbB-2 oncogene was also demonstrated. To our knowledge, this is the first report to demonstrate an overexpression of p185 c-neu on ML cells. These findings suggest that the p185 neu may be a prognostic indicator not only for breast adenocarcinomas but also for lymphoproliferative disorders, and that the transforming p185 protein may be involved in the mechanisms of aggressive expansion of lymphoid neoplasias.

CD4+, CD45RA+, CD29- T-cell lymphocytic leukemia functioning as T suppressor inducer for B-cell immunoglobulin synthesis.

We describe here a case of T-cell lymphocytic leukemia (T-CLL) which coexpressed CD4 and CD45RA cell-surface antigens and functioned as suppressor inducer cells. The patient, an 81 year-old man, had massive generalized lymphadenopathy. His hemoglobin was 9.4g/dl, the platelet count 94,000, and the WBC was 895,000/microliters with 98% abnormal lymphoid cells. He had massive hepatosplenomegaly. Serum LDH was elevated to 3,990 u/l. The T-CLL cells coexpressed antigens detected by MAbs CD2, CD3, CD4, CD5, Ti(TcR alpha/beta; WT31) CD45 and CD45RA, but did not express any other antigens including CD1, CD8, CD29, and TCR gamma/delta, Ti gamma A and TQ-1. The cell-surface phenotypes of the cultured cells established by utilizing recombinant interleukin 2 were basically the same as those of the uncultured peripheral blood lymphoid cells. Both the peripheral blood and cultured cells clearly showed gene rearrangement for T cell receptors, TcR beta and TcR gamma. No association with human T-cell leukemia virus-1 (HTLV-1) was found by means of electron microscopic studies or the application of MAbs to p19 and p24 of HTLV-1. No anti-HTLV-1 antibody was detected. By the means of two color fluorescence, it was clearly demonstrated that the leukemic cells possessing CD4 in the peripheral blood and cell cultures coexpressed CD45RA, but did not express either CD29 or TQ-1. In vitro immunoglobulin synthesis by normal T and B cells was remarkably reduced in the presence of CD8+ T and leukemic cells. This suggests suppressor inducer T cell activity for the leukemic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Survival of T- and B-Phenotype Diffuse Aggressive Non-Hodgkin's Lymphomas.

Survival of immunophenotyped non-Hodgkin's lymphomas (NHLs) diagnosed as diffuse mixed, diffuse large and large cell immunoblastic by the working formulation was evaluated based on phenotypic categories. These subtypes were grouped as diffuse aggressive NHLs due to their similarities, and categorized into T- and B-phenotype NHLs. There were 45 (57.7%) cases of T-NHL and 33 (42.3%) B-NHL. Major clinical factors such as sex, age, stage, B-symptoms and site of disease, as well as performance status (PS), LDH, primary site and number of extra-nodal sites involved showed equal distributions between T- and B-NHLs. Combination chemotherapeutic regimens based on doxorubicin were used in 84% of these cases. Complete remission was achieved in 73.6% of T-NHL and 74.1% of B-NHL. Median survival for the T- and B-NHL was the same over 30 months. Projected survival at 5 years was also similar, T-NHL (35%) and B-NHL (38%). Unilaterally, survival was adversely affected in stage III/IV of T-NHL and for age over 65 years for B-NHL. Survival was unfavorable for the B-NHL without B-symptoms when compared to T-NHLs. Multivariately, only sex, B-symptoms and PS significantly (P < 0.05) affected the survival of T-NHL. Although the overall results indicate that the response and survival of T- and B-NHL are similar, the differences observed on the effect of sex, age, stage, B-symptoms and PS on survival of T- and B-NHLs imply that, their influence on T-NHLs was different from that for B-NHLs. Therefore we suggest that separate prognostic models are needed for the T- and B-phenotype NHLs.

Long-term maintenance combination chemotherapy with OPEC/MPEC (vincristine or methotrexate, prednisolone, etoposide and cyclophosphamide) or with daily oral etoposide and prednisolone can improve survival and quality of life in adult T-cell leukemia/lymphoma.

Acute leukemia and lymphoma varieties of adult T-cell leukemia/lymphoma (ATL) usually carry a poor prognosis. While etoposide is generally useful for treating ATL, especially as a daily oral maintenance regimen, etoposide has not proven effective in severe types of ATL efficient in some patients. Of 87 ATL patients whom we have treated, 51 had acute leukemia, 22 lymphoma and 14 progressive chronic leukemia. Seventy-nine patients were treated with a long term maintenance combination protocol, OPEC/MPEC (weekly doses of vincristine, 0.7 mg/m2 or methotrexate, 14 mg/m2; prednisolone, 20 mg/m2; etoposide, 70 mg/m2 and cyclophosphamide, 200 mg/m2). The other 8 patients, 3 with acute leukemia, 2 with lymphoma and 3 with progressive chronic leukemia, were treated with daily oral administration of 25 mg of etoposide and 10 mg of prednisolone (DOEP). The dose administered was modified in individual cases to maintain the granulocyte count and reduce the number of ATL cells. Considering both protocols, a complete response and a partial response were achieved in 31.0% and 58.6% patients, respectively. Median survival times (MST) of all patients and, acute leukemia, lymphoma and progressive chronic leukemia types were 7.5, 6.7, 9.6 and 12.4 months, respectively. Respective MST of patients treated with OPEC/MPEC or DOEP protocols were 7.1 and 18.0 months. Relatively normal WBC counts, lower lactate dehydrogenase concentration and normal calcium concentration, limited numbers of anatomic sites involved, good performance status and good response to chemotherapy were significantly associated with long survival time. Drug toxicity was not apparent, and about half of patients were treated in an outpatient setting.

Relationships between attention effects and intensity effects on the cognitive N140 and P300 components of somatosensory ERPs.

OBJECTIVES: This study attempts to elucidate the relative contributions of exogenous and endogenous components to the N140 and P300 potentials elicited by somatosensory stimulation. METHODS: Somatosensory event-related potentials (ERPs) were evoked using an odd-ball paradigm with the frequent (80%) stimuli delivered to the left index finger and the infrequent (20%) stimuli delivered to the right index finger. Both types of stimuli had the same intensity within each experiment. The experiment was repeated using 6 different stimulus intensities ranging from the sensory threshold to 3 times the threshold. Each experiment was done under two conditions. In one, the subjects were asked to count and respond to the infrequent stimuli. In the other, the subjects were instructed to ignore the stimuli whether frequent or infrequent. In addition, the compound sensory potential of the right median nerve was separately recorded from electrodes at the wrist using the same range of stimulus intensities applied to the right index finger. RESULTS: Amplitudes of the N140 and P300 elicited by both attended and unattended infrequent stimuli increased in a parallel fashion as a function of stimulus intensity, so that the amplitude difference between attended and unattended responses was independent of the stimulus intensity. The amplitude of the compound sensory nerve potential at the wrist exhibited a similar slope to those of the N140 and P300. CONCLUSIONS: Thus, it is concluded that the scalp N140 and P300 consist of two components: an endogenous component, which is independent of the stimulus intensity, and an exogenous component, which increases as a function of stimulus intensity. The relative contribution of these components to the N140 and P300 amplitudes is also discussed.

Circadian rhythm in the retinal pigment epithelium related to vitamin B12.

The wake-sleep rhythm is a typical circadian rhythm. It has been reported that severely disturbed wake-sleep rhythms are improved by the administration of vitamin B12. This study was designed to clarify whether vitamin B12 is universally related to the circadian rhythm. Three-week-old male Wistar Kyoto rats were fed a vitamin B12 deficient diet for 3 months. Then some of them were given intraperitoneal injections of vitamin B12. We counted phagocytized lamellar structures in the retinal pigment epithelium after the start of exposure to light in negative electron microscopic films. In vitamin B12 deficient rats, the maximum number of phagocytized lamellar structures in the retinal pigment epithelium appeared 3 hours after the start of light exposure, while in the control and vitamin B12 injected groups the peak occurred at 2 hours. This difference suggests that the retinal circadian rhythm is closely related to the level of vitamin B12.

Phylogenetic position of endosymbiotic green algae in Paramecium bursaria Ehrenberg from Japan.

Endosymbiotic green algae of Japanese Paramecium bursaria were phylogenetically analyzed based on DNA sequences from the ribosomal DNA operon (18S rDNA, ITS1, 5.8S rDNA, and ITS2). Phylogenetic trees constructed using 18S rDNA sequences showed that the symbionts belong to the Chlorella sensu stricto (Trebouxiophyceae) group. They are genetically closer to the C. vulgaris Beijerinck group than to C. kessleri Fott et Nováková as proposed previously. Branching order in C. vulgaris group was unresolved in 18S rDNA trees. Compared heterogeneities of 18S rDNA, ITS1, 5.8S r, and ITS2 among symbionts and two Chlorella species, indicated that the ITS2 region (and probably also ITS1) is better able to resolve phylogenetic problems in such closely related taxa. All six symbiotic sequences obtained here (approximately 4000-bp sequences of 18S rDNA, ITS1, 5.8S rDNA, and ITS2) were completely identical in each, strongly suggesting a common origin.

A novel chitinase inhibitor from a marine bacterium, Pseudomonas sp.

A new chitinase inhibitor, CI-4, was isolated from the culture broth of a marine bacterium Pseudomonas sp. IZ208. The structure of CI-4 was determined to be cyclo(L-Arg-D-Pro) by spectral studies and comparison with a synthetic sample. CI-4 showed inhibitory activity against chitinase.