Origin and evolution of the colonial volvocales (Chlorophyceae) as inferred from multiple, chloroplast gene sequences

A combined data set of DNA sequences (6021 bp) from five protein-coding genes of the chloroplast genome (rbcL, atpB, psaA, psaB, and psbC genes) were analyzed for 42 strains representing 30 species of the colonial Volvocales (Volvox and its relatives) and 5 related species of green algae to deduce robust phylogenetic relationships within the colonial green flagellates. The 4-celled family Tetrabaenaceae was robustly resolved as the most basal group within the colonial Volvocales. The sequence data also suggested that all five volvocacean genera with 32 or more cells in a vegetative colony (all four of the anisogamous/oogamous genera, Eudorina, Platydorina, Pleodorina, and Volvox, plus the isogamous genus Yamagishiella) constituted a large monophyletic group, in which 2 Pleodorina species were positioned distally to 3 species of Volvox. Therefore, most of the evolution of the colonial Volvocales appears to constitute a gradual progression in colonial complexity and in types of sexual reproduction, as in the traditional volvocine lineage hypothesis, although reverse evolution must be considered for the origin of certain species of Pleodorina. Data presented here also provide robust support for a monophyletic family Goniaceae consisting of two genera: Gonium and Astrephomene.

Gibbestatin B inhibits the GA-induced expression of alpha-amylase expression in cereal seeds

The expression of alpha-amylase in aleurone layers of barley is known to be induced by gibberellin A3 (GA). In the present study, gibbestatin B (GNB) was isolated from Streptomyces sp. C-39 as an inhibitor of the GA-induced expression of alpha-amylase in barley and rice, with IC50 values of 125 and 70 microM, respectively. GNB suppressed accumulation of GA-induced barley high-pI type B and rice RAmylA alpha-amylase transcripts. However, GNB showed no inhibitory activity on GUS expression in transgenic tobacco harboring the auxin-inducible par B promoter:: GUS fusion gene. The transcription of an abscisic acid (ABA)-inducible gene, HVA1, was unaffected by GNB. In addition, GNB prevented aleurone cells from cell death induced by GA. In tobacco and Arabidopsis plants, GNB suppressed the germination and retarded the growth of seedlings without toxicity. The growth of gai, spy and abi mutants was also retarded by GNB. Normal plants treated with GA-biosynthesis inhibitors and GA-defective and GA-signaling mutants normally have dwarf dark green leaves. However, dwarfed healthy green leaves were observed in normal plants treated with GNB. GA-induced stem elongation of plants was also detected in the presence of GNB. These analyses indicate that GNB inhibits the GA-induced expression of alpha-amylase by regulating one of the steps involved in ABA signaling, but not by acting as a weak ABA analog.

A Japanese logographic character frequency list for cognitive science research

This paper describes a Japanese logographic character (kanji) frequency list, which is based on an analysis of the largest recently available corpus of Japanese words and characters. This corpus comprised a full year of morning and evening editions of a major newspaper, containing more than 23 million kanji characters and more than 4,000 different kanji characters. This paper lists the 3,000 most frequent kanji characters, as well as an analysis of kanji usage and correlations between the present list and previous Japanese frequency lists. The authors believe that the present list will help researchers more accurately and efficiently control the selection of kanji characters in cognitive science research and interpret related psycholinguistic data.

Energy correction for isolated impurities under periodic boundary conditions

The Coulomb energy of aperiodic systems was investigated. To treat completely isolated disorder in infinite systems, energy correction for a supercell method is presented. We discuss a definition of the correction term, and then consider a direct approach taking into account interactions between charge distribution and an indirect approach based on a multipole expansion. In test calculations for isotropic-charged, anisotropic-charged, and neutral impurities, impurity energies independent of supercell sizes were obtained. The present energy correction can be applied to arbitrary systems and is expected to realize more practical simulations for aperiodic systems.

[Epileptogenesis of acute encephalitis and acute encephalopathy: epilepsy with its onset in the acute phase and without a latent period]

Epileptogenesis was evaluated in 60 patients with acute encephalitis and in 10 patients with acute encephalopathy. Forty-seven patients have been seizure-free during for more than three years' follow-up (Group III). On the other hand, 23 patients developed epilepsy. Among them, 18 patients developed epilepsy after a latent period of 1 month to 2 3/12 years (Group I). In Group I, a younger age of the onset, a long period of disturbed consciousness and a high activity of CSF neuron-specific enolase (NSE) was associated with refractory epilepsy. The other five patients had continuous seizures from the acute phase of encephalitis without a latent period (Group II). They had more than 2 types of partial motor seizures which occurred frequently during the acute phase of encephalitis. The NSE activity in the CSF of patients in Group II was less than 50 ng/ml, being similar to those in Group III. The epilepsy in Group II, however, was the most refractory. The reason for the development of this continuous refractory epilepsy remained obscure.

[Liver function of the most elderly patients]

To determine the decision level of liver function in the most elderly patients, we compared serum albumin, aspartate aminotransferase(AST), alanine aminotransferase(ALT) and alkaline phosphatase(ALP) values of the most elderly patients > 85 years with those of healthy young adults. Two hundred fifty five elderly people, aged 88-106 years and average 96.6 years(171 women, 84 men), were included in this study. Elderly people were divided into four groups according to their activities of daily living(ADL), 114 Rank-J: free living, 62 Rank-A: unable to go outside without help, 39 Rank-B: bedridden but able to sit up in bed and 40 Rank-C: completely bedridden. Serum albumin values for the most elderly patients in Rank-J were 4.2 +/- 0.3 g/dl for women and 4.0 +/- 0.3 g/dl for men, showing marked decrease from those of young healthy adults aged 19-59 years(p < 0.0001). In 22.2% of elderly women and 44.2% of elderly men, albumin values deviated from the reference interval of young adults. ALT value for the most elderly patients also showed a decrease in both sexes and AST and ALP values for the most elderly patients showed an increase in women compared with young adults. However, these were minor deviations from the reference interval for young adults. In ADL-stratified groups of the most elderly patients, serum albumin values showed marked decrease with decline in ADL, whereas AST, ALT and ALP values remained constant in both sexes regardless of ADL.

New paralytic alkaloids, asperparalines A, B and C, from Aspergillus japonicus JV-23

New paralytic alkaloids, asperparalines A (1), B (2) and C (3), were isolated from okara (the insoluble residue of whole soybean) that had been fermented with Aspergillus japonicus JV-23. Their structures were elucidated by spectroscopic methods and X-ray crystallography. These asperparalines showed paralytic activity against silk worms.

Evaluation of human tooth structure with the ultrasonic imaging technique

In recent years, ultrasonic waves have been an interesting subject for studies due to their wide range of applications in medical diagnoses. In this study, the acoustic properties of the structure of human teeth was determined with the ultrasonic imaging technique. This study may offer some fundamental findings related to the clinical application of the ultrasonic imaging technique in the further development of a virtual system for dental education and research. Twenty freshly-extracted permanent human teeth (10 molars and 10 premolars) were used to investigate their acoustic velocity and impedance by the ultrasonic image analyzing system with a high-resolution focusing probe. Additionally, the relationship between the acoustic properties and the hardness of the teeth was evaluated. It was found that the acoustic properties of the human teeth were influenced by factors related to their structure, such as degree of calcification, distribution of dentinal tubules, and volume of the dentin matrix. The acoustic velocity and impedance showed an apparent correspondence to the hardness of tooth. This analyzing system provides visual information related to tooth structure that can easily quantitatively evaluate their acoustic properties. It is expected that this system will have a wide range of applications and be further developed for clinical uses.

[Alteration of cAMP-mediated signal transduction in cerebral ischemia--binding activity of PKA and phosphorylation of CREB]

Binding of cAMP to the regulatory subunit of cAMP-dependent protein kinase (PKA) is an essential step for cAMP-mediated signal transduction including phosphorylation of cAMP response element binding protein (CREB). In the present study, binding activity of PKA with cAMP and CREB phosphorylation were examined in rat focal brain ischemia induced by occlusion of the middle cerebral artery for 1.5 hours followed by various time of recirculation. Binding activity of PKA with cAMP was progressively inhibited during the acute phase of ischemia from the ischemic core to peri-ischemia area. Phosphorylated CREB-positive cells in the ischemic core revealed a significant, but transient increase in number at 3.5 hours of recirculation, followed by a rapid decrease below the control level during the subsequent period. On the other hand, in the peri-ischemia area, the number of phosphorylated CREB-positive cells showed a more marked increase as compared to that in the ischemic core, and the increase continued until 48 hours of recirculation with a tendency for gradual decline. Persistent enhancement of CREB phosphorylation may thus be closely related to the neuronal viability and neuroprotective mechanisms, whereas rapid disappearance of CREB phosphorylation following ischemic insult may clearly precede neuronal death.

[Short interval change of 99mTc-ethyl cysteinate dimer single photon emission computed tomography in Wilson's disease]

We studied short interval change of cranial computed tomography (CT), magnetic resonance imaging (MRI) and 99mTc-ethyl cysteinate dimer single photon emission computed tomography (99mTc-ECD SPECT) in a case of Wilson's disease. Before treatment, CT scan showed low density changes in the bilateral thalamus and basal ganglia, and MRI demonstrated high intensity in same lesions. 99mTc-ECD SPECT study revealed a hypoperfusion in bilateral thalamus. After 2 months under D-penicillamine therapy, neurological findings had improvement. Hypoperfusion in the thalamus with 99mTc-ECD SPECT significantly improved, whereas abnormal findings of CT scan and MRI persisted. 99mTc-ECD SPECT study may be useful for the planning of the treatment of Wilson's disease.

[A case of breast cancer with liver metastases responding remarkably to combination therapy of mitoxantrone (MIT), doxifluridine (5'-DFUR) and medroxyprogesterone acetate (MPA)]

A 60-year-old woman with her right breast cancer showing simultaneous and multiple liver metastases was initially treated with CEFT [cyclophosphamide (CPA), epirubicin (epi-ADM), 5-fluorouracil (5-FU), tamoxifen (TAM)]. After one treatment course the primary lesion did not decrease while tumor markers and liver lesion size increased. Therefore, the foul-smelling primary lesion was resected followed by treatment with mitoxantrone (MIT), 10 mg intravenously every 4 weeks as well as daily/oral administrations of doxifluridine (5'-DFUR) and medroxyprogester-one acetate (MPA). Following MIT administration, the tumor markers decreased markedly, so treatment was continued. After the third course, therapy was continued on an outpatient basis. During treatment WBC reduction to about 3,000/microliter was the only adverse reaction. After 10 courses, the tumor markers were normal, and after 15 courses there were no liver metastases on abdominal CT. Generally, patients with resistance to standard anthracycline chemotherapy are difficult to treat. Those with liver metastasis especially have a poor response which results in a poor prognosis. However, therapy with MIT, 5'-DFUR and MPA may be useful in previously treated, advanced and recurrent breast cancer. Furthermore, this therapy can be done on an outpatient basis, which presumably improves the quality of life (QOL).

Role of the ryanodine receptor in ischemic brain damage--localized reduction of ryanodine receptor binding during ischemia in hippocampus CA1

1. The ryanodine receptor has recently been shown to play a pivotal role in the regulation of intracellular Ca2+ concentration via Ca(2+)-induced Ca2+ release (CICR). Effects of ischemia on CICR in the brain tissue, however, remain largely unknown since only a few reports have been published on this subject. In this paper we report on work in this area by our group and review related progress in this field. 2. We examined alterations of ryanodine receptor binding and local cerebral blood flow (LCBF) at 15 min, 30 min, and 2 hr after occlusion of the right common carotid artery in the gerbil brain. A quantitative autoradiographic method permitted simultaneous measurement of these parameters in the same brain. The LCBF was significantly reduced in most of the cerebral regions on the occluded side during each time period of ischemia. In contrast, only in the hippocampus CA1 on the occluded side was a significant reduction in ryanodine binding found at 15 min, 30 min and 2 hr after the occlusion. 3. These findings suggest that suppression of ryanodine binding in the hippocampus CA1 may be attributable to a regionally specific perturbation of CICR and that this perturbation may be closely associated with the pathophysiological mechanism that leads to be selective ischemic vulnerability of this region. 4. Other recent studies have also reported an important role for ryanodine receptors in neuronal injury such as the delayed neuronal death in the hippocampus CA1. These data suggest that derangement of CICR is likely to be involved in acute neuronal necrosis as well as in delayed neuronal death in ischemia. 5. Further studies on clarifying the role of CICR in ischemic brain damage are needed in order to develop new therapeutic strategies for stroke patients.

Role of cortical microtubules in the orientation of cellulose microfibril deposition in higher-plant cells

Cortical microtubules (MTs) have been implicated in the morphogenesis of plant cells by regulating the orientation of newly deposited cellulose microfibrils (CMFs). However, the role of MTs in oriented CMF deposition is still unclear. We have investigated the mechanism of CMF deposition with cultured tobacco protoplasts derived from taxol-treated BY-2 cells (taxol protoplasts). The BY-2 protoplasts regenerated patches of beta-l,3-glucan (callose) and fibrils of beta-l,4-glucan (cellulose). Taxol protoplasts possessed the same ordered MT arrays as material cells and regenerated CMFs with patterns almost coincidental with MTs. Electron microscopy revealed that, on the surface of cultured taxol protoplasts, each CMF bundle appeared to be deposited on each cortical MT. These results suggest that MTs may attach directly to the cellulose-synthesizing complexes, by some form of linkage, and regulate the movement of these complexes in higher-plant cells.

[A case of giant advanced breast cancer responding remarkably to chemo-endocrine therapy chiefly with doxifluridine]

A 68-year-old woman presented with advanced ulcerative breast cancer of the precordium; edema of the face, cervix and bilateral upper extremities; dyspnea from carcinomatous pleurisy; and multiple bone metastases, which suggested a terminal state. Her general condition improved with symptomatic therapies; thus, doxifluridine (5'-DFUR) and an endocrine therapeutic drug were given to reduce the primary focus, eliminate the edemas and decrease the plural effusion. When the tumor markers increased again, CEFT therapy [cyclophosphamide (CPA), epirubicin (epi-ADM), 5-fluorouracil (5-FU) and tamoxifen (TAM)] was conducted. This resulted in no adverse drug reaction, further reduction of the primary focus, and extremely improved Performance status (PS). The patient was discharged on 5'-DFUR and TAM therapy, which resulted in scarring of the ulcer, normalization of tumor marker levels, disappearance of the pleural effusion, and a reduction of metastatic bone foci. The findings suggest 5'-DFUR and endocrine therapeutic drugs can have a favorable clinical effect without impacting QOL and should be employed in patients with advanced cancer and poor general condition.

[Central nervous system tuberculosis: diagnosis and therapy]

Tuberculous meningitis is the most serious form of tuberculosis, but often the only manifestation of tuberculosis with non-specific initial signs and symptoms. Therefore, delayed diagnosis occasionally results into rapid progression of neurologic deficits and a poor prognosis. So, it is needless to mention that appropriate chemotherapy should be started as fast as possible under swift diagnosis. According to recent progression of molecular biological technique, PCR and other nucleic acid amplification methods are becoming to be quite useful for rapid detection of Mycobacterium tuberculosis in the cerebrospinal fluid. If diagnostic tests are not definitely positive but there is a strong clinical suspicion for tuberculous meningitis, it is advisable to start the antituberculous chemotherapy as soon as possible. The combination chemotherapy with isoniazid, rifampicin, pyrazinamide, and streptomycin (or ethambutol) is a standard treatment for tuberculous meningitis. The administration of corticosteroids with adequate antituberculous chemotherapy should be considered in severe cases for reduction in mortality and neurologic sequelae, especially when there is the indication of subarachnoid block or impending brain herniation.

Successful surgical treatment for hepatic encephalopathy caused by a pancreatic siphon: report of a case

We report herein the case of a 39-year-old man with cirrhosis of the liver who developed hepatic encephalopathy and progressive diabetes caused by a pancreatic siphon after undergoing a distal splenorenal shunt (DSRS) for a variceal hemorrhage. Radiologic occlusion was judged to be inappropriate because of the extensive DSRS. The DSRS was surgically closed 6 years after the operation to restore portal perfusion. To alleviate the portal hypertension, splenectomy and gastric devascularization were performed, which proved successful, as the encephalopathy disappeared completely, the ammonia levels decreased, liver function improved, and the diabetes subsided. Our experience indicates that a small percentage of cirrhotic patients who undergo DSRS with longterm followup may develop various undesirable complications, although some of these patients benefit from a combination of surgical shunt occlusion, splenectomy, and gastric devascularization.

Phylogenetic position of the Phacotaceae within the Chlamydophyceaeas revealed by analysis of 18S rDNA and rbcL sequences

Four genera of the Phacotaceae (Phacotus, Pteromonas, Wislouchiella, Dysmorphococcus), a family of loricated green algal flagellates within the Volvocales, were investigated by means of transmission electron microscopy and analysis of the nuclear encoded small-subunit ribosomal RNA (18S rRNA) genes and the plastid-encoded rbcL genes. Additionally, the 18S rDNA of Haematococcus pluvialis and the rbcL sequences of Chlorogonium elongatum, C. euchlorum, Dunaliella parva, Chloromonas serbinowii, Chlamydomonas radiata, and C. tetragama were determined. Analysis of ultrastructural data justified the separation of the Phacotaceae into two groups. Phacotus, Pteromonas, and Wislouchiella generally shared the following characters: egg-shaped protoplasts, a single pyrenoid with planar thylakoid double-lamellae, three-layered lorica, flagellar channels as part of the central lorica layer, mitochondria located in the central cytoplasm, lorica development that occurs in mucilaginous zoosporangia that are to be lysed, and no acid-resistant cell walls. Dysmorphococcus was clearly different in each of the characters mentioned. Direct comparison of sequences of Phacotus lenticularis, Pteromonas sp., Pteromonas protracta, and Wislouchiella planctonica revealed DNA sequence homologies of >/=98. 0% within the 18S gene and 93.9% within the rbcL gene. D. globosus was quite different from these species, with a maximum of 92.9% homology in the 18S rRNA and </=86.6% in the rbcL gene. It showed major similarities to the 18S rDNA of Dunaliella salina, with 95.3%, and to the rbcL sequence of Chlamydomonas tetragama, with 90.3% sequence homology. Additionally, the Phacotaceae sensu stricto exclusively shared 10 (rbcL: 4) characters which were present neither in other Chlamydomonadales nor in Dysmorphococcus globosus. Different phylogenetic analysis methods confirmed the hypothesis that the Phacotaceae are polyphyletic. The Phacotaceae sensu stricto form a stable cluster with affinities to the Dunaliellaes and possibly Haematococcus pluvialis. Dysmorphococcus globosus represented an independent lineage that is possibly related to Chlamydomonas moewusii and C. tetragama.

[Serum albumin level and activities of daily living in centenarians]

The relationship between serum albumin level and activities of daily living was studied in 95 centenarians. There were 73 women (12 rank J: free-living, 18 rank A: unable to go outside without help, 20 rank B: bedridden but able to sit on the bed, 23 rank C: completely bedridden) and 22 men (9 rank J, 7 rank A, 6 rank B or C). The serum albumin level (mean +/- S.D. 4.0 +/- 0.4 g/dl) of the rank J women was at the lower limit of normal for young adults. The albumin levels of rank A, rank B, and rank C were 3.7 +/- 0.4 g/dl, 3.5 +/- 0.3 g/dl, and 3.4 +/- 0.4 g/dl, respectively. The levels of rank B and rank C women were significantly lower than that of rank J women. The albumin level of rank J men (3.9 +/- 0.3 g/dl) was lower than that of young adults. The albumin level of ranks B and C men (3.1 +/- 0.3 g/dl) was significantly lower than that of rank J men. The A/G ratio or albumin fraction (%) measured by serum electrophoresis was similar to that of the serum albumin level of centenarians of both sexes. There were no significant differences in the serum protein level or in the peripheral hemoglobin level between rank J centenarians and those of other ranks, for both sexes. The serum albumin level is a valuable indicator of the ability to perform activities of daily living and may be a useful prognostic index in centenarians.

[Serum globulin levels and activities of daily living in centenarians]

Serum globulin levels in 101 centenarians (77 women, 24 men) were analyzed by zonal electrophoresis and immunoglobulin assays. Six subjects showed an M band in electrophoretograms. Five M bands were immunoglobulin G (IgG) type and one was IgA. One subject was suspected to suffer from IgG-type multiple myeloma, and the others were thought to have essential (benign) monoclonal gammopathy. The relationship between serum globulin levels and activities of daily living (ADL) was studied in remaining 95 subjects. There were 21 rank-J (free-living), 25 rank-A (unable to go outside without help), 23 rank-B (bedridden but able to sit on the bed), and 26 rank-C (completely bedridden) centenarians. The mean serum alpha 1-, alpha 2-, and beta-globulin level in the rank-J centenarians was at the upper limit of the normal adult range. The mean alpha 1-globulin levels in rank-B (3.3 +/- 0.4%) and C (3.4 +/- 0.5%) subjects were significantly higher than those in rank-J (2.9 +/- 0.3%) centenarians. The mean serum gamma-globulin level of rank-J centenarians (16.9 +/- 3.7%) was within the normal range. The mean gamma-globulin levels in rank-B (21.0 +/- 2.7%) and C (22.8 +/- 4.9%) subjects were significantly higher than that in rank-J centenarians. The mean immunoglobulin G concentrations in rank-B (1.620 +/- 304 mg/dl) and C (1.720 +/- 392 mg/dl) subjects were significantly higher than those in rank-J centenarians (1.320 +/- 361 mg/dl) and in normal adults (1.150 +/- 235 mg/dl). IgA concentrations in all centenarians were higher than in normal controls. There was no significant difference in IgA or IgM concentration between rank-J subjects and those in other ranks. Serum globulin levels measured with electrophoresis, and the immunoglobulin concentrations, can be valuable indicators of the ability to perform activities of daily living, and may be useful predictors of subclinical diseases or morbidity in centenarians.

Biotransformation of shiromodiol diacetate, myli-4(15)-en-9-one and myliol by Aspergillus niger

Microbiol biotransformation of shiromodiol diacetate from Neolitsea serisea koids, and of myli-4(15)-en-9-one and myliol from the liverwort Mylia taylorii, were carried out with Aspergillus niger IFO 4407. A. niger hydroxylated the allyl position (C-2) of shiromodiol diacetate, and one of the geminal dimethyl groups of myli-4(15)-en-9-one and myliol regioselectively. The structures of these transformants were elucidated by spectral analysis and confirmed by X-ray analysis.

Anthraquinones from Neonauclea calycina and their inhibitory activity against DNA topoisomerase II

In a series of searches for DNA topoisomerase II inhibitors from naturally occurring compounds, a wood extract of Neonauclea calycina MERR. (Rubiaceae) showed a moderate effect in vitro. Purification of the extract resulted in the isolation of seven known anthraquinones. The structures were characterized as damnacanthal, rubiadin 1-methyl ether, nordamnacanthal, morindone, damnacanthol, lucidin 3-O-primeveroside and morindone 6-O-primeveroside by spectral analysis, respectively. Damnacanthal and morindone showed an intensive inhibitory effect against topoisomerase II (IC50: 20 micrograms/ml and 21 micrograms/ml).

Characterization of rbcL group IA introns from two colonial volvocalean species (Chlorophyceae)

Group I introns were reported for the first time in the large subunit of Rubisco (rbcL) genes, using two colonial green algae, Pleodorina californica and Gonium multicoccum (Volvocales). The rbcL gene of P. californica contained an intron (PIC intron) of 1320 bp harboring an open reading frame (ORF). The G. multicoccum rbcL gene had two ORF-lacking introns of 549 (GM1 intron) and 295 (GM2 intron) base pairs. Based on the conserved nucleotide sequences of the secondary structure, the PIC and GM1 introns were assigned to group IA2 whereas the GM2 intron belonged to group IA1. Southern hybridization analyses of nuclear and chloroplast DNAs indicated that such intron-containing rbcL genes are located in the chloroplast genome. Sequencing RNAs from the two algae revealed that these introns are spliced out during mRNA maturation. In addition, the PIC and GM1 introns were inserted in the same position of the rbcL exons, and phylogenetic analysis of group IA introns indicated a close phylogenetic relationship between the PIC and GM1 introns within the lineage of bacteriophage group IA2 introns. However, P. californica and G. multicoccum occupy distinct clades in the phylogenetic trees of the colonial Volvocales, and the majority of other colonial volvocalean species do not have such introns in the rbcL genes. Therefore, these introns might have been recently inserted in the rbcL genes independently by horizontal transmission by viruses or bacteriophage.

Presence of the CO2-concentrating mechanism in some species of the pyrenoid-less free-living algal genus Chloromonas (Volvocales, Chlorophyta)

Physiological and morphological characteristics related to the CO2-concentrating mechanism (CCM) were examined in several species of the free-living, unicellular volvocalean genus Chloromonas (Chlorophyta), which differs morphologically from the genus Chlamydomonas only by lacking pyrenoids. The absence of pyrenoids in the chloroplasts of Chloromonas (Cr.) rosae UTEX 1337, Cr. serbinowii UTEX 492, Cr. clatharata UTEX 1970, Cr. rosae SAG 26.90, and Cr. palmelloides SAG 32.86 was confirmed by light and electron microscopy. In addition, immunogold electron microscopy demonstrated that ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39) molecules were distributed almost evently throughout the chloroplasts in all five Chloromonas strains. However, Chloromonas exhibited two types of physiological characteristics related to the CCM depending on the species or strains examined. Chloromonas rosae UTEX 1337 and Cr. serbinowii had high photosynthetic affinities for CO2 in cells grown in culture medium bubbled with air (low-CO2 cells), compared with those grown in medium bubbled with 5% CO2 (high-CO2 cells), indicating the presence of the low-CO2-inducible CCM. In addition, these two Chloromonas strains exhibited low-CO2-inducible carbonic anhydrase (CA; EC 4.2.1.1) activity and seemed to have small intracellular inorganic carbon pools. Therefore, it appears that Cr. rosae UTEX 1337 and Cr. serbinowii possess the CCM as in pyrenoid-containing microalgae such as Chlamydomonas reinhardtii. By contrast, Cr. clatharata, Cr. rosae SAG 26.90 and Cr. palmelloides showed low photosynthetic affinities for CO2 when grown under both CO2 conditions. Moreover, these three strains exhibited an apparent absence of intracellular inorganic carbon pools and lacked low-CO2-inducible CA activity. Thus, Cr. clatharata, Cr. rosae SAG 26.90 and Cr. palmelloides, like other pyrenoid-less algae (lichen photobionts) reported previously, seem to lack the CCM. The present study is the first demonstration of the CCM in pyrenoid-less algae, indicating that pyrenoids or accumulation of Rubisco in the chloroplasts are not always essential for the CCM in algae. Focusing on this type of CCM in pyrenoid-less algae, the physiological and evolutionary significance of pyrenoid absence is discussed.

Binding capacity of FK506 binding protein after 2-hour hemispheric ischemia in gerbil brain

The binding capacity of FK506 binding protein (FKBP) was examined after 2-h hemispheric ischemia in the gerbil brain in order to clarify the precise mechanism of the neuroprotective effects of FK506. Firstly, the FK506 binding was evaluated in vitro in the normal gerbil brain using 1 nM [3H]dihydro-FK506 as a specific ligand. FK506 binding sites were distributed in a rather homogeneous manner, although the greatest binding was noted in the hippocampus CA1. Secondly, Scatchard analysis demonstrated that the binding sites of FK506 could be composed of two components in each brain region. Thirdly, 18 Mongolian gerbils were divided into two groups: an ischemia group (n = 12) and a sham group (n = 6). The right common carotid artery was ligated to induce hemispheric ischemia for 2 h in the ischemia group. The local cerebral blood flow was measured at the end of the experiment by the [14C]iodoantipyrine method. The ligated animals with levels of local cerebral blood flow in the lateral nuclei of the thalamus of less than 50 ml/100 g/min were utilized as the ischemia group (n=6) for further data analysis. No significant differences in FK506 binding between the ischemia and sham groups were observed in any regions. The above data indicate that the binding capacity of FKBP tends to remain normal during 2-h ischemia, suggesting that FK506 may exert its neuroprotective effects through its binding to FKBP in the brain during the early phase of cerebral ischemia.

Analysis of the cluster of ribosomal protein genes in the plastid genome of a unicellular red alga Cyanidioschyzon merolae: translocation of the str cluster as an early event in the rhodophyte-chromophyte lineage of plastid evolution

The nucleotide sequence of a cluster of ribosomal protein genes in the plastid genome of a unicellular red alga, Cyanidioschyzon merolae, which has been supposed to be the most primitive alga, was determined. The phylogenetic tree inferred from the amino acid sequence of ribosomal proteins of two rhodophytes, a chromophyte, a glaucophyte, two chlorophytes (land plants), a cyanobacterium, and three eubacteria suggested a close relationship between the cyanobacterium Synechocystis PCC6803 and the plastids of various species in the kingdom Plantae, which is consistent with the hypothesis of the endosymbiotic origin of plastids. In this tree, the two species of rhodophytes were grouped with the chromophyte, and the glaucophyte was grouped with the chlorophytes. Analysis of the organization of the genes encoding the ribosomal proteins suggested that the translocation of the str cluster occurred early in the lineage of rhodophytes and chromophytes after these groups had been separated from chlorophytes and glaucophytes.

Numerical and functional characteristics of lymphocyte subsets in centenarians

The immune system in the aged is a very interesting subject for study. In this study, analysis was extended to extrathymic T cells as well as NK cells and "conventional" T cells (i.e., thymus-derived T cells) in terms of their constitution and function in both healthy and unhealthy centenarians. Middle-aged persons were used as controls. Healthy and unhealthy centenarians showed lower levels in the proportion and absolute number of lymphocytes. The major change in the constitution of lymphocyte subsets was increased levels in the proportion of NK cells (CD56+/CD57+) and extrathymic T cells (CD3+CD57+). Inversely, conventional T cells decreased in proportion and function (i.e., proliferative response to mitogen). Although NK cells increased in centenarians, NK activity by whole lymphocytes and the purified NK fraction decreased. The difference between healthy and unhealthy centenarians was small in all parameters, the only difference being a lower level of expression of CD56 antigens on CD57+ T cells in unhealthy centenarians. These results indicate that there is a major shift in lymphocyte population from conventional T cells to NK cells and extrathymic T cells with aging. Concerning the age-associated increases in CD56+ T and CD57+ T cells, these cells correspond to NK1+ T cells in mice.

Collection of anopheline mosquitos in three villages endemic for malaria in Khammouane, Lao PDR

Anopheline mosquito collections were made during the months of May and June (dry season) and August (rainy season), 1996 at villages, Nakham, Namdik and Hinboon Neua in Khammouane Province. Larval collections were also made in 3 slow running streams around Nakham villages in May 1996. Altogether, 3,549 adult females consisting 19 Anopheles species were collected by 3 nights of human and 6 animal bait traps and 3 resting collections. Among them, Anopheles vagus (19.75%), An. philippinensis (15.02%), An. nivipes (11.55%), An. pallidus (11.27%), An. peditaeniatus (8.34%), An. kochi (8.00%) and An. barbirostris (7.27%) were predominant species. The immatures of An. barbirostris, An. minimus, An. maculatus sensu lato, and An. culicifacies were found in the streams of Nakham. It is noteworthy that An. minimus, An. dirus and An. maculatus sensu lato, which are well known malaria vectors in Thailand, were recorded for the first time in this area.

Relationship between pupil size and acetylcholinesterase activity in patients exposed to sarin vapor

OBJECTIVE

To elucidate the effect of sarin vapor on pupil size and erythrocyte acetylcholinesterase activity (AchE).

DESIGN

Retrospective observational survey.

SETTING

Emergency department of an urban teaching hospital.

PATIENTS

80 patients who were exposed to sarin in a terrorist attack in Tokyo subways.

MEASUREMENTS AND RESULTS

Pupil size and AchE activity on the day of exposure were measured. Among the 80 patients, the pupils were miotic (< 3 mm) in 50 patients (62.5%), while AchE activity was below the normal range (< 1.2 U) in 34 patients (42.5%). AchE was significantly lower in the miotic group than in the group with normal pupils (1.0 +/- 0.5 U vs 1.5 +/- 0.3 U, p < 0.01). In the miotic group, AchE activity was lower than normal in 32 patients (64.0%) but was decreased in only 2 patients in the normal pupil group (6.7%) (p < 0.01).

CONCLUSIONS

Miosis is a more sensitive index of exposure to sarin vapor than erythrocyte AchE. Systemic poisoning is apparently less likely to develop if the patient's pupil size is normal on arrival at the hospital.

Acute ischemic vulnerability of PKA in the dendritic subfields of the hippocampus CA1

Alterations of [3H]cyclic AMP (cAMP) binding, an indicator of the binding activity of particulate cyclic AMP-dependent protein kinase (PKA), were examined after 15 and 30 min of ischemia in the gerbil brain. Severe hemispheric cerebral ischemia was induced by occluding the right common carotid artery. Significant reductions in cAMP binding were noted only in the dendritic subfields of the hippocampus CA1 such as the strata oriens, radiatum and lacunosum-moleculare, on the ischemic side after 15 min of ischemia. After 30 min ischemia cAMP binding was significantly decreased not only in each dendritic subfield of the hippocampus CA1, but also in the layer of pyramidal cell bodies (stratum pyramidale) on the occluded side; other brain regions such as the hippocampus CA3, dentate gyrus and cerebral cortices revealed no significant changes in cAMP binding. These findings suggest that derangement of PKA may begin in the dendritic subfields of the hippocampus CA1 after as little as 15 min of severe ischemia, and proceed centrally to the neuronal cell bodies of the hippocampus CA1.

Tissue and subcellular distributions, and characterization of rat brain protein phosphatase 2A containing a 72-kDa delta/B" subunit

A 74-kDa delta/B" subunit was isolated by heparin-Sepharose column chromatography from human erythrocyte protein phosphatase 2A (PP2A) consisting of a 34-kDa catalytic subunit (alpha/C) and 63- and 74-kDa regulatory subunits (beta/A and delta/B") in a ratio of 1:1:1. The purified delta/B" was used as an immunogen in mice, to prepare specific antisera against delta/B". Immunoblot analyses with the antisera detected an immunoreactive 72-kDa protein in the cytosol from various rat tissues including erythrocytes, brain, lung, testis, adrenal gland, heart, spleen, kidney, and liver. The 72-kDa protein was highly abundant in brain and was distributed evenly in cerebral cortex, cerebellum, and brain stem. The 72-kDa protein was also detected in mitochondria and microsome fractions. An immunoreactive 68-kDa protein was detected mainly in nuclear and microsome fractions. The 72-kDa protein from rat brain cytosol copurified with phosphorylated H2B histone phosphatase activity during successive chromatographies on DEAE-Toyopearl, AH-Sepharose, Sephadex G-150, H1 histone-Toyopearl, TSK DEAE-5PW, protamine-Toyopearl, and TSK G3000SW columns. The purified enzyme migrated as a single protein band on nondenaturing PAGE and as three protein bands of 34, 63, and 72 kDa in a ratio of 1:1:1 on SDS-PAGE. The molecular weight of the enzyme was estimated to be 170,000 from the s20,W value of 7.2 +/- 0.3 S and the Stokes radius of 5.5 +/- 0.1 nm. The rat brain enzyme was classified as PP2A, based on the following properties; (1) an IC50 for okadaic acid of 10(-9) M; (2) its preferential dephosphorylation of the a subunit of phosphorylase kinase; (3) its insensitivity to protein inhibitor 2; and (4) its heterotrimeric subunit structure. The Km value and the molecular activity of the enzyme for phosphorylated H2B histone were 72.3 +/- 0.3 microM and 192 +/- 2 mol Pi released/min/mol enzyme, respectively, and were comparable to those of human erythrocyte PP2A (alpha1 beta1 delta1/ CAB"). The 72-kDa subunit in the purified rat brain PP2A was phosphorylated in vitro by cAMP-dependent protein kinase.

Rapid reduction in ryanodine binding of hippocampus CA1 in cerebral ischemia

Ryanodine receptors located on the sarcoplasmic or endoplasmic reticulum, play an important role in the regulation of the intracellular Ca2+ level via the mechanism of Ca(2+)-induced Ca2+ release (CICR). Perturbation of intracellular Ca2+ regulation has been considered to be one of the most important mechanisms underlying acute ischemic neuronal damage. The ryanodine binding, an indicator of intracellular channels of CICR, and local cerebral blood flow (LCBF) were therefore examined at 15 min post-ischemia in the gerbil brain. The autoradiographic method developed in our laboratory enabled us to determine both parameters within the same brain. Severe hemispheric cerebral ischemia was induced by occluding the right common carotid artery. LCBF was measured at the end of the experiment using [14C]iodoantipyrine method. The ryanodine binding was evaluated autoradiographically in vitro using [3H] ryanodine. A group of gerbils who underwent a sham procedure served as controls. LCBF was found to be significantly decreased in most cerebral regions on the occluded side. In contrast, a significant reduction in ryanodine binding was noted only in the hippocampus CA1 on the occluded side. Taken together, these findings indicate that the CICR in the hippocampus CA1 may be especially susceptible to acute ischemic stress, and be closely associated with the pathophysiological mechanisms of the selective vulnerability of this region.

Calcineurin inhibitor, FK506, prevents reduction in the binding capacity of cyclic AMP-dependent protein kinase in ischemic gerbil brain

We examined the effects of FK506, a specific inhibitor of calcineurin, on the binding capacity of cyclic AMP-dependent protein kinase (cAMP-DPK) in gerbils subjected to 2-h cerebral hemispheric ischemia. FK506 (0.1 mg/kg) was infused intravenously at 15 min prior to the induction of ischemia by common carotid artery occlusion. The binding capacity of cAMP-DPK was evaluated by autoradiographic analysis of the cAMP binding, and cerebral blood flow (CBF) was measured by the [14C] iodoantipyrine method. In the sham-operated gerbils. FK506 significantly increased mean arterial blood pressure and tended to decrease CBF, suggesting that FK506 may constrict systemic blood vessels as well as cerebral blood vessels. On the other hand, cAMP binding was not altered by FK506 in the sham-operated gerbils. In the ischemia group of gerbils, FK506 prevented any significant reduction of cAMP binding in the hippocampus CA1 and cerebral cortices on the ischemic side, whereas it exerted no significant influence on the cAMP binding of the nonischemic side. The values of CBF were comparable between the vehicle-treated gerbils and FK506-treated gerbils in the ischemic regions. Preservation of cAMP binding indicates that intracellular signal transduction via cAMP-DPK can be maintained by FK506 despite ischemia, suggesting that this agent may be beneficial for reducing ischemic tissue damage.

[Clinical features of 5 cases of tuberculous meningitis--with special reference to brain CT and MRI findings]

We evaluated the clinical features of 5 cases of tuberculous meningitis who had been admitted to our department from 1987 to 1994. Three patients were male and two were female. Their age ranged from 17 to 74 years old. All cases were examined by both CT and MRI before and during antituberculous treatment. Before the treatment, CT scan revealed abnormal findings such as nodular lesion suggesting tuberculoma, subarachnoid contrast enhancement or cerebral infarction in 2 cases, while MRI revealed abnormal findings such as inflammatory lesions with Gd-enhancement in 4 out of 5 patients. During the treatment, all abnormal findings except cerebral infarction disappeared. No abnormal findings were detected by CT. MRI and SPECT in one case who showed right hemiparesis and motor aphasia. In summary, CT scan could demonstrate abnormal findings in only a small portion of patients with tuberculous meningitis. One the other hand, MRI revealed various abnormal findings in most patients, and could reveal some lesions which could be responsible for the symptoms of patients. In a few patients, however, MRI could not show any lesion in spite of obvious focal neurological signs. MRI is considered to be useful for detecting the lesions in most patients with tuberculous meningitis, although its findings are not always specific for the disease.

Respiratory stimulation and generation of superoxide radicals in Pseudomonas aeruginosa by fungal naphthoquinones

The mechanism of action of antimicrobial naphthoquinones from the fungus Fusarium was studied by using Pseudomonas aeruginosa. Bostricoidin, methyl ether fusarubin, and fusarubin stimulated the oxygen consumption of bacterial cells and induced cyanide-insensitive oxygen consumption. These activities of the tested compounds were also observed in bacterial membrane preparations in a dose-dependent manner. Naphthoquinones stimulated the generation of superoxide anion and hydrogen peroxide. The naphthoquinone effectively acted as the electron acceptors for bacterial diaphorase, which could explain the antibacterial activity of Fusarium naphthoquinones since electron acceptors lead to the stimulation of respiratory activity and the generation of oxygen radical species.

Mitochondrial encephalomyopathies preceded by de-Toni-Debré-Fanconi syndrome or focal segmental glomerulosclerosis

We report two rare cases of mitochondrial encephalomyopathies which were preceded by renal diseases. One occurred in an 11-year-old girl diagnosed with Kearns-Sayre syndrome, which was preceded by de-Toni-Debré-Fanconi syndrome 8 years previously. The other occurred in a 14-year-old girl diagnosed with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes, who developed focal segmental glomerulosclerosis 3 years prior to confirmation of the diagnosis. Tissue from both patient demonstrated morphological abnormalities of the mitochondria in the distal renal tubular epithelium and leiomyocytes of the small renal artery. The present cases illustrate various clinical and morphologic evidence of renal diseases which may further our understanding of mitochondrial encephalomyopathies.

Alteration of ryanodine receptor in the hippocampus CA1 after hemispheric cerebral ischemia

Alterations in ryanodine binding and local cerebral blood flow (LCBF) were examined at 30 minutes and 2 hours post-ischemia in the gerbil brain in order to evaluate the influence of cerebral ischemia on the intracellular channels of Ca2+-induced Ca2+ release (CICR). Severe hemispheric cerebral ischemia was induced by occluding the right common carotid artery. LCBF was measured at the end of the experiment using [14C]iodoantipyrine method, and the ryanodine binding was evaluated in vitro using [3H]ryanodine as a specific ligand for CICR channels. An autoradiographic method developed in our laboratory enabled us to determine both parameters within the same brain. A group of gerbils who underwent a sham procedure served as controls. LCBF was found to be significantly reduced in most of the cerebral regions on the occluded side at both 30 minutes as well as 2 hours post-ischemia. In contrast, a significant reduction in ryanodine binding was noted only in the hippocampus CA1 on the occluded side at 30 minutes and 2 hours after the occlusion. These findings suggest that regionally specific changes of CICR may be the cause of decreased ryanodine binding in the hippocampus CA1, and that these changes may be related to the pathophysiological mechanisms that cause this region to be particularly vulnerable to ischemia.

Phaeophytins from a cell suspension culture of the liverwort Plagiochila ovalifolia

A suspension culture of the liverwort Plagiochila ovalifolia was established from callus tissue induced by culturing spores. From the cultured cells, four phaeophytins were isolated as major components and their structures determined by spectroscopic methods. The phaeophytin derivatives showed antibacterial activity. A major sesquiterpenoid, ovalifoliene, found in the mother plant, was detected in the cultures by GC-mass spectrometry.

Flow threshold for reduction of cyclic AMP binding in the hippocampus CA1 and other brain regions during stroke development in gerbils

The flow threshold for alterations of the in vitro [3H]cyclic AMP (cAMP) binding, an indicator of the total amount of particulate cAMP-dependent protein kinase, was evaluated in the gerbil brain after 30 min, 2 h, and 6 h of unilateral common carotid artery occlusion, respectively. The autoradiographic method developed in our laboratory enabled us to measure the [3H]cAMP binding and local CBF in each region of the same brain. The ischemic flow thresholds for reduction of the cAMP binding in the hippocampus CA1 were 18, 34, and 49 ml 100 g-1 min-1 after 30-min, 2-h, and 6-h ischemia, respectively. These values were higher than those in other regions such as the hippocampus CA, and temporal cerebral cortex in each duration of ischemia. These findings indicate that (a) the ischemic flow threshold for perturbation of the cAMP system may be higher in the hippocampus CA1 than in other brain regions, suggesting that the hippocampus CA1 could be especially vulnerable to acute ischemic stress; and (b) the level of the aforementioned threshold may increase progressively during the time course of ischemia in particular regions such as the hippocampus CA1 and CA3, suggesting that the duration of ischemia exerts a definite influence on the viability of the ischemic neuronal cells in these regions.

[-Clinical features of 10 cases of tuberculous meningitis--with special reference to patient's delay and doctor's delay]

We retrospectively evaluated the clinical findings of 10 cases of tuberculous meningitis who had been admitted to our department from 1987 to 1994. Four patients were male and six were female. All of them were Japanese, and their age ranged from 17 to 74 years old. Regarding the patient's delay, nine patients visited a doctor in 1 to 20 days after the onset of headache, and one patient visited a doctor in 14 days after the onset of general malaise. It is suggested that the patient's delay could not be longer than 3 weeks because of progressively worsening symptoms of tuberculous meningitis such as severe headache and fever. The time interval between the first contact of the patient to a doctor and the commencement of antituberculous therapy (doctor's delay), ranged from 14 to 66 days. When the diagnosis of meningitis was obtained based on the findings of the cerebrospinal fluid (CSF), focal neurological signs including psychological symptoms, cranial nerve palsies and seizure were noted besides meningeal signs or the disturbance of consciousness in 4 patients. The CSF revealed an increase in cell counts with mononuclear cell dominance in 9 patients, but the findings typical for tuberculous meningitis such as increase in total protein content and a decrease in glucose concentration were obtained in only 5 patients. Mycobacterium tuberculosis had not been detected in all cases when the antituberculous chemotherapy was started. Later, it was found to be positive in the CSF sample from only three patients by culture or polymerase chain reaction (PCR) method. When the antituberculous therapy was completed, meningitis was cured without remaining any symptom or sign in all patients. All patients had no active pulmonary tuberculosis when the meningitis was diagnosed, and only one of them had sequels of lung tuberculosis. Four patients had the past history of tuberculosis, and 1 had the familial history of pulmonary tuberculosis. At the first contact to a doctor, seven patients were diagnosed as having common cold or headache related with fever because of the lack of typical signs of meningitis. Similarly three other patients were initially diagnosed as having meningitis due to viral infection or unknown etiology. In summary, it was difficult to obtain the solid diagnosis of tuberculous meningitis at the initial stage of this disease, since the symptoms and signs at its onset often similar to those of common cold or non-specific headache. Therefore, when we see the patients with subacute onset of headache and fever followed by the meningeal signs, tuberculous meningitis should always be included in the list of diseases requiring differential diagnosis. In addition, when tuberculous meningitis is suspected, the antituberculous therapy should be started without any delay.

Regulation of NK activity by the administration of bromocriptine in haloperidol-treated mice

Haloperidol (HPD) is a dopamine receptor blocker and a major causative agent of neuroleptic malignant syndrome. To investigate the influence of HPD on immune responsiveness, the natural killer (NK) cell activity of mice was examined after intraperitoneal administration of HPD for 5 days. NK cell activity was markedly decreased without a depletion of NK cells. Bromocriptine (BROMO), which is used for the treatment of neuroleptic malignant syndrome, also decreased NK cell activity. The suppressive effect on NK cell activity was inhibited by injecting both HPD and BROMO simultaneously. Serum levels of prolactin (PRL) decreased after BROMO injection, although serum PRL level was not decreased after the combined administration of HPD and BROMO agents. The reduction of NK cell activity caused by BROMO and by HPD was prevented by the co-injection of PRL and by a beta-adrenergic blocker, respectively. These results indicate that HPD decreases NK cell activity in a PRL-independent manner and that BROMO decreases it via PRL reduction. It seems that the PRL-independent suppressive effect of HPD on NK cells, which is neutralized by BROMO, is mediated by splenic sympathetic function via the beta-adrenergic receptor system. Therefore, BROMO helps to alleviate the depressed NK cell activity caused by HPD therapy.

Molecular cloning of a 74-kDa regulatory subunit (B" or delta) of human protein phosphatase 2A

Based on amino acid sequence data of a 74-kDa regulatory subunit (B" or delta) of a human heterotrimeric protein phosphatase 2A, a cDNA encoding the subunit was isolated from a human cerebral cortex library. The cDNA had an open reading frame encoding an M(r) 66,138 protein of 570 amino acids. Bacterial expression of the cDNA yielded a protein immunoreactive with antisera specific to the 74-kDa subunit. The predicted primary structure of the subunit had no similarity to already reported sequences of PP2A regulatory subunits including A, B, and PR72. Potential phosphorylation sites for protein kinases A and C, a bipartite motif of putative nuclear localization signal, and SH3 accessible proline-rich domain, and a unique PQ repeat were found in the sequence. The subunit mRNA of about 2.9 kb was ubiquitously expressed in rat tissues.