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Makoto Kato

Publications and source records attributed to Makoto Kato.

At least 19 recordsLinked to original sources
PubMed2007

The input-output balance of cadmium in a paddy field of Tokyo.

Field monitoring was practiced from 2001 to 2003 to evaluate the input (irrigation, atmospheric deposition, and fertilizer application) and the output (uptake and accumulation into the above-ground biomass of rice plants and leaching) of cadmium (Cd) in a contaminated paddy field in Tokyo. The cadmium concentrations of irrigated water, open-bulk precipitation, soil solution (leaching water), rice plants collected at the harvesting stage and the chemical fertilizer and the cow manure compost applied were determined. The Cd flux of each factor was calculated by multiplying the Cd concentration by the volume or mass of the media. The annual input-output balance of Cd in the paddy field in 2001 and 2002 was estimated to be -5.44 [corrected] g ha(-1) and -2.01 [corrected] g ha(-1), respectively, indicating the loss of Cd from the paddy field, although the losses accounted for only 0.24% [corrected] and 0.089% [corrected] of the total amount of Cd in the ploughed layer soil in 2001 and 2002, respectively. Among the factors involved, the input from fertilizers (including manure compost) and the output due to the uptake by rice plants played a major role in the balance. The former largely depended on the types and amounts of fertilizers applied, and the latter on the water management practices in the paddy field, such as flooding and drainage of the surface water.

Animals↗
PubMed2006

A novel obligate cultivation mutualism between damselfish and Polysiphonia algae.

In cultivation mutualisms, farming animals prepare fields for cultivars, enhance their growth and harvest them. For example, in terrestrial ecosystems, plant-herbivore cultivation mutualisms arose between humans and their crops only relatively recently. We discovered an obligate cultivation mutualism between a damselfish and an alga in a coral reef ecosystem. The damselfish, Stegastes nigricans, manages algal farms through territorial defence against the invading grazers and through weeding of unpalatable algae. As a result, the algal farms of S. nigricans are dominated by one species, Polysiphonia sp. We performed an exhaustive survey of algal assemblages inside and outside the territories of five damselfish species around the Ryukyu Islands, Japan, using molecular and morphological characteristics. Polysiphonia sp. 1 grew exclusively inside the farms of S. nigricans, and never elsewhere. Since only Polysiphonia sp. 1 is harvested and consumed by the damselfish as a staple food, this interdependent relationship is an obligate cultivation mutualism. This is the first record of an obligate plant-herbivore cultivation mutualism in a marine ecosystem. Our data also suggest that three other Polysiphonia species are facultatively mutual with, commensal with, or parasitic on other damselfish species.

Animals↗
PubMed2006

Assessment of the diversity and species specificity of the mutualistic association between Epicephala moths and Glochidion trees.

The obligate mutualisms between flowering plants and their seed-parasitic pollinators constitute fascinating examples of interspecific mutualisms, which are often characterized by high levels of species diversity and reciprocal species specificity. The diversification in these mutualisms has been thought to occur through simultaneous speciation of the partners, mediated by tight reciprocal adaptation; however, recent studies cast doubt over this general view. In this study, we examine the diversity and species specificity of Epicephala moths (Gracillariidae) that pollinate Glochidion trees (Phyllanthaceae), using analysis of mitochondrial and nuclear gene sequences. Phylogenetic analysis of Epicephala moths associated with five Glochidion species in Japan and Taiwan reveal six genetically isolated species that are also distinguishable by male genital morphology: (i) two species specific to single host species (G. acuminatum and G. zeylanicum, respectively); (ii) two species that coexist on G. lanceolatum; and (iii) two species that share two, closely-related parapatric hosts (G. obovatum and G. rubrum). Statistical analysis shows that the two species associated with G. lanceolatum are not sister species, indicating the colonization of novel Glochidion host in at least one lineage. Behavioural observations suggest that all six species possess the actively-pollinating habit, thus none of the studied species has become a nonmutualistic 'cheater' that exploits the benefit resulting from pollination by other species. Our results parallel recent findings in ecologically similar associations, namely the fig-fig wasp and yucca-yucca moth mutualisms, and contribute to a more general understanding of the factors that determine ecological and evolutionary outcomes in these mutualisms.

Adaptation, Physiological↗
PubMed2006

Altered allergic cytokine and antibody response in mice treated with Bisphenol A.

The objective of this study was to elucidate if Bisphenol A (BPA) administration modulates T helper (Th) cell component of immune responses in a mouse challenged with ovalbumin (OVA), a major food antigen. BALB/c mice, (6 weeks old, female) were orally given either OVA (OVA-fed) or water (Water-fed), immunized intraperitoneally with OVA and injected with either BPA in corn oil or the vehicle alone. After subsequent 2nd immunization, serum titers of total IgE, OVA-specific IgE, IgG, IgG1 IgG2a and ability of their splenocytes for production of interferon (IFN) -gamma, interleukin (IL) -4 and IL-12 were examined by ELISA. Lymphocyte proliferation assay against concanavalin A (Con A) or OVA was also performed for 3H-Thymidine incorporation. In Water-fed groups, treatment with BPA resulted in lower titers of total IgE (P<0.01) and higher levels IgG2a (P<0.05) followed by a higher IFN-gamma (P<0.05) and IL-12 (P<0.05) with an intact IL-4. When OVA-fed groups were examined, the compound did not change production of total and OVA-specific IgE and -IgG2a but resulted in lower production of IFN-gamma (P<0.05). Also, BPA resulted in impaired lymphocyte proliferation to Con A in Water-fed groups (P<0.05) but not in tolerated animals. The findings indicate that BPA results in augmentation of Th1 immune responses but no significant effect on an established tolerance to OVA.

Animals↗
PubMed2006

Non-palpable and non-invasive ductal carcinoma with bloody nipple discharge successfully resected after cancer spread was accurately diagnosed with three-dimensional computed tomography and galactography.

A case of ductal carcinoma in situ (DCIS) that was treated by partial mastectomy is reported. The operation was performed after accurate estimation of cancer spread by three-dimensional computed tomography (3D-CT). The patient was a 39-year-old woman without a palpable lump who had a bloody nipple discharge. Ultrasonography showed distended mammary ducts with intraductal components. Fine needle aspiration cytology revealed ductal carcinoma. Galactography showed two subsegmental ducts and peripheral branches in the upper-inner quadrant of the right breast. 3D-CT depicted a well enhanced segmental-clumped lesion including two subsegments of a duct lobular system shown in galactograms. DCIS was diagnosed and partial mastectomy following the video assisted thoracoscopic surgery (VATS) marker insertion was performed, after cancer spread was accurately diagnosed by 3D-CT guidance. DCIS resected by minimally sufficient partial mastectomy with negative surgical margins was diagnosed histopathologically.

Adult↗
PubMed2004

The sensorimotor transformation of cross-modal spatial information in the anterior intraparietal sulcus as revealed by functional MRI.

The parietal cortex in monkeys and humans has been shown to play an important role in the transformation of sensory information to motor commands. However, it is still unclear whether in humans, these areas are divided functionally into subregions based on different combinations of sensory and motor modalities. To identify subregions in the parietal cortex involved in the sensorimotor information transformation between different modalities, functional MRI was used to examine brain areas activated during tasks requiring different sensorimotor transformations--i.e., various combinations of eye (saccade) or finger movements triggered by visual or somatosensory cues. We then compared the activations between cross-modal conditions (eye movements triggered by somatosensory cues and finger movements triggered by visual cues) and intramodal (eye movements triggered by visual cues and finger movements triggered by somatosensory cues) conditions. Although the parietal cortex was involved in all tasks regardless of sensorimotor combinations, the only region activated to a greater degree in the cross-modal conditions compared to the intramodal conditions was the anterior portion of the intraparietal sulcus (a-IPS). The results suggest that the a-IPS plays an important role in the sensorimotor transformation of cross-modal spatial information.

Adult↗
PubMed2004

Nonuniform concerted evolution and chloroplast capture: heterogeneity of observed introgression patterns in three molecular data partition phylogenies of Asian Mitella (saxifragaceae).

Interspecific hybridization is one of the major factors leading to phylogenetic incongruence among loci, but the knowledge is still limited about the potential of each locus to introgress between species. By directly sequencing three DNA regions: chloroplast DNAs (matK gene and trnL-F noncoding region), the nuclear ribosomal external transcribed spacer (ETS) region, and internal transcribed spacer (ITS) regions, we construct three phylogenetic trees of Asian species of Mitella (Saxifragaceae), a genus of perennials in which natural hybrids are commonly observed. Within this genus, there is a significant topological conflict between chloroplast and nuclear phylogenies and also between the ETS and the ITS, which can be attributed to frequent hybridization within the lineage. Chloroplast DNAs show the most extensive introgression pattern, ITS regions show a moderate pattern, and the ETS region shows no evidence of introgression. Nonuniform concerted evolution best explains the difference in the introgression patterns between the ETS region and ITS regions, as the sequence heterogeneity of the ITS region within an individual genome is estimated to be twice that of an ETS in this lineage. Significant gene conversion patterns between two hybridizing taxa were observed in contiguous arrays of cloned ETS-ITS sequences, further confirming that only ITS regions have introgressed bidirectionally. The relatively slow concerted evolution in the ITS regions probably allows the coexistence of multiple alleles within a genome, whereas the strong concerted evolution in the ETS region rapidly eliminates heterogeneous alleles derived from other species, resulting in species delimitations highly concordant with those based on morphology. This finding indicates that the use of multiple molecular tools has the potential to reveal detailed organismal evolution processes involving interspecific hybridization, as an individual locus varies greatly in its potential to introgress between species.

Asia↗
PubMed2004

Cospeciation analysis of an obligate pollination mutualism: have Glochidion trees (Euphorbiaceae) and pollinating Epicephala moths (Gracillariidae) diversified in parallel?

Species-specific obligate pollination mutualism between Glochidion trees (Euphorbiaceae) and Epicephala moths (Gracillariidae) involves a large number of interacting species and resembles the classically known fig-fig wasp and yucca-yucca moth associations. To assess the extent of parallel cladogenesis in Glochidion-Epicephala association, we reconstruct phylogenetic relationships of 18 species of Glochidion using nuclear ribosomal DNA sequences (internal and external transcribed spacers) and those of the corresponding 18 Epicephala species using mitochondrial (the cytochrome oxidase subunit I gene) and nuclear DNA sequences (the arginine kinase and elongation factor-1alpha genes). Based on the obtained phylogenies, we determine whether Glochidion and Epicephala have undergone parallel diversification using several different methods for investigating the level of cospeciation between phylogenies. These tests indicate that there is generally a greater degree of correlation between Glochidion and Epicephala phylogenies than expected in a random association, but the results are sensitive to selection of different phylogenetic hypotheses and analytical methods for evaluating cospeciation. Perfect congruence between phylogenies is not found in this association, which likely resulted from host shift by the moths. The observed significant discrepancy between Glochidion and Epicephala phylogenies implies that the one-to-one specificity between the plants and moths has been maintained through a complex speciation process or that there is an underestimated diversity of association between Glochidion trees and Epicephala moths.

Animals↗
PubMed2003

An obligate pollination mutualism and reciprocal diversification in the tree genus Glochidion (Euphorbiaceae).

Highly coevolved pollination mutualism accompanied by reciprocal diversification has been known in only two plant genera, Ficus (Moraceae) and Yucca (Agavaceae), which are pollinated exclusively by obligate seed-parasitic wasps and moths, respectively. An additional, highly diversified, species-specific pollination mutualism between a monoecious tree genus, Glochidion (Euphorbiaceae), and a moth genus, Epicephala (Gracillariidae), is presented here. At night, the small female moth actively deposits pollen on the cryptic stigma of the female flower by using its proboscis, then oviposits into the style. The moth larva infests only a portion of the developing seeds within fruit. We confirmed that at least three Glochidion species are pollinated only by their respective seed-parasitic moth species, which could be distinguished by genitalic morphology and mitochondrial DNA sequences. These results and widespread evidence of limited seed infestation by the moths associated with Glochidion species suggest that speciation based on the highly specialized Glochidion stylar structure and moth oviposition behavior have promoted species diversification in Glochidion and its pollinators.

Animals↗
PubMed2003

Mucocele-like tumor of the breast caused by ductal carcinoma in situ: a case report.

A mucocele-like tumor (MLT) of the breast caused by clinging and micropapillary carcinoma in situ is reported. The tumor was a smooth-contoured mass located near the nipple in the lower inner quadrant of the left breast. Ultrasonography showed a cystic tumor and distended ducts. An aspiration specimen contained abundant mucinous material and a small amount of epithelial cell components, but was insufficient for cytological diagnosis. An excisional biopsy specimen disclosed multiple cysts containing mucin with extravasation into the stroma. Additional pathologic diagnosis using consecutive microscopic sections demonstrated ductal carcinoma in situ. Subcutaneous mastectomy was subsequently performed. Histopathologic findings in the resected and biopsy specimens indicated a diagnosis of MLT caused by widely spreading clinging and micropapillary ductal carcinoma in situ. The ductal epithelium of the MLT in an open biopsy specimen must be carefully examined using consecutive microscopic sections to detect occult DCIS.

Adult↗
PubMed2003

Information flow related to visual search assessed using magnetoencephalography.

The sequence of neural activation during a visual search task was investigated using magnetoencephalography and the source locations for the activations were analyzed using a single-dipole algorithm. Five components (M1-5) were detected at mean latencies of 110, 146, 196, 250 and 333 ms in both of two different stimulus conditions; a target popped out in one stimulus condition (pop-out), while it did not in the other condition (non-pop-out). Statistical analysis showed that the M3 amplitude was larger and the M5 latency was shorter in the pop-out condition than in the non-pop-out condition, while there was no difference in the other components between the conditions. Neural sources were localized in the calcarine sulcus (M1) and the posterior fusiform gyrus (M2) of the hemisphere contralateral to the stimuli, the intraparietal sulcus and the posterior superior temporal sulcus (M3) in either of the hemispheres, and the calcarine sulcus (M4) of the same hemisphere in which the early processing (M1 and M2) occurred. The criteria for source localization were not satisfied for M5. The results suggest that the processing for pop-out and non-pop-out stimuli share a common mechanism; after early feature processing in the occipital cortex (M1 and M2), visual information is processed in the parietal and temporal regions (M3) and then some of this information is fed back to the occipital cortex (M4).

Adult↗
PubMed2003

Functional MRI of brain activation evoked by intentional eye blinking.

Eye blinking is not only a reflexive action to protect the ocular surface from injury and desiccation; it can also be done intentionally. However, only a few studies have investigated the brain mechanism controlling intentional blinking, and there are still inconsistencies among the reported activation patterns in the human brain evoked by intentional blinking. In monkeys, some areas where blinking is evoked by electrical microstimulation have been found in the premotor areas and in the posterior parietal cortex. But there have been no reports about neuronal activity related to blinking in the cerebral cortex. In the present study, the brain activation evoked by intentional blinking was examined in humans by using fMRI, and the activations were found in the middle precentral gyrus, but not in the posterior parietal cortex, suggesting that the premotor areas, rather than the posterior parietal cortex, are important for controlling intentional blinking.

Adult↗
PubMed2003

Human precentral cortical activation patterns during saccade tasks: an fMRI comparison with activation during intentional eyeblink tasks.

Some fMRI studies in humans have located the frontal eye field (FEF) in two distinct regions along the precentral sulcus (PCS): one localized more medically, in the superior precentral sulcus (supPCR) at the junction with the superior frontal sulcus, and the other localized more laterally, along the medial part of the inferior precentral sulcus (infPCR). However, there has been no evidence of any different task activations between the regions. In the present study using fMRI, we have compared activation patterns in the regions near the PCS during saccade, fixation, and eyeblink tasks. We found that only the supPCR was activated specifically by the saccade task, while the infPCR was activated by both the saccade and eyeblink tasks. This result provides evidence that the supPCR is the human FEF homologous to the monkey FEF and that the infPCR may be homologous to the monkey premotor area.

Adult↗
PubMed2003

Evolution and phylogenetic utility of alignment gaps within intron sequences of three nuclear genes in bumble bees (Bombus).

To test whether gaps resulting from sequence alignment contain phylogenetic signal concordant with those of base substitutions, we analyzed the occurrence of indel mutations upon a well-resolved, substitution-based tree for three nuclear genes in bumble bees (Bombus, Apidae: Bombini). The regions analyzed were exon and intron sequences of long-wavelength rhodopsin (LW Rh), arginine kinase (ArgK), and elongation factor-1alpha (EF-1alpha) F2 copy genes. LW Rh intron had only a few uninformative gaps, ArgK intron had relatively long gaps that were easily aligned, and EF-1alpha intron had many short gaps, resulting in multiple optimal alignments. The unambiguously aligned gaps within ArgK intron sequences showed no homoplasy upon the substitution-based tree, and phylogenetic signals within ambiguously aligned regions of EF-1alpha intron were highly congruent with those of base substitutions. We further analyzed the contribution of gap characters to phylogenetic reconstruction by incorporating them in parsimony analysis. Inclusion of gap characters consistently improved support for nodes recovered by substitutions, and inclusion of ambiguously aligned regions of EF-1alpha intron resolved several additional nodes, most of which were apical on the phylogeny. We conclude that gaps are an exceptionally reliable source of phylogenetic information that can be used to corroborate and refine phylogenies hypothesized by base substitutions, at least at lower taxonomic levels. At present, full use of gaps in phylogenetic reconstruction is best achieved in parsimony analysis, pending development of well-justified and generally applicable methods for incorporating indels in explicitly model-based methods.

Animals↗
PubMed2002

Prognostic power of ventilatory responses during submaximal exercise in patients with chronic heart disease.

BACKGROUND: Although parameters obtained during submaximal exercise are known to be useful for predicting mortality in cardiac patients, it has been a matter of debate whether the submaximal parameters are superior to peak oxygen uptake (VO(2)). For this purpose, we aimed to determine the best index among exercise variables in predicting long-term mortality in patients with chronic heart disease. METHODS: The study population consisted of 385 consecutive patients with chronic heart disease who performed a symptom-limited incremental exercise test on a cycle ergometer. Breath-by-breath respiratory gas analysis was used to estimate the peak VO(2), the ratio of the increase in VO(2) to the increase in work rate (WR) [VO(2)/Delta WR], and the ratio of the increase in minute ventilation E to the increase in carbon dioxide output (VCO(2)) [Delta VE/Delta VCO(2)]. RESULTS: After 1,899 +/- 495 days of follow-up (mean +/- SD), 33 cardiovascular-related deaths occurred. Nonsurvivors achieved lower peak VO(2), lower VO(2)/Delta VWR, and higher Delta VE/Delta VCO(2) compared to the survivors. In the univariate Cox proportional hazards analysis, peak VO(2), VO(2)/Delta VWR, and Delta VE/Delta VCO(2) were found to be significant prognostic indexes of survival. However, multivariate analysis revealed O(2)/Delta VWR as an independent predictor of mortality and Delta VE/delta VCO(2) as a slightly weaker predictor. In this analysis, the prognostic power of peak O(2) was insignificant. CONCLUSION: Submaximal respiratory gas indexes are very likely to be more sensitive than peak VO(2) for predicting poor survival in ambulatory patients with chronic heart disease.

Carbon Dioxide↗
PubMedDate not supplied

Preparation of aliphatic poly(thioester) by the lipase-catalyzed direct polycondensation of 11-mercaptoundecanoic acid.

An aliphatic polythioester was enzymatically prepared by the direct polycondensation of mercaptoalkanoic acid using immobilized lipase of Candida antarctica (lipase CA) in bulk. The commercially available 11-mercaptoundecanoic acid was polymerized by lipase CA in bulk in the presence of molecular sieves 4A as a water absorbent at 110 degrees C for 48 h to produce poly(11-mercaptoundecanoate) with an M(w) of 34 000 in high yield. The 104.5 degrees C melting temperature (T(m)) of poly(11-mercaptoundecanoate) was about 20 degrees C higher than that of the corresponding polyoxyester, poly(11-hydroxyundecanoate). The polythioester was readily transformed by lipase into the corresponding cyclic oligomers mainly consisting of the dimer, which were readily repolymerized by the ring-opening polymerization using lipase as a sustainable chemical recycling.

Candida↗