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N Hatanaka

Publications and source records attributed to N Hatanaka.

At least 19 recordsLinked to original sources
PubMed2004

Organization of prefrontal outflow toward frontal motor-related areas in macaque monkeys.

Linkage between the prefrontal cortex and the primary motor cortex is mediated by nonprimary motor-related areas of the frontal lobe. In an attempt to analyse the organization of the prefrontal outflow from area 46 toward the frontal motor-related areas, we investigated the pattern of projections involving the higher-order motor-related areas, such as the presupplementary motor area (pre-SMA) and the rostral cingulate motor area (CMAr). Tracer injections were made into these motor-related areas (their forelimb representation) on the medial wall that had been identified electrophysiologically. The following data were obtained from a series of tract-tracing experiments in Japanese monkeys. (i) Only a few neurons in area 46 were retrogradely labelled from the pre-SMA and CMAr; (ii) terminal labelling from area 46 occurred sparsely in the pre-SMA and CMAr; (iii) a dual labelling technique revealed that the sites of overlap of anterograde labelling from area 46 and retrograde labelling from the pre-SMA and CMAr were evident in the rostral parts of the dorsal and ventral premotor cortices (PMdr and PMvr); (iv) and tracer injections into the PMdr produced neuronal cell labelling in area 46 and terminal labelling in the pre-SMA and CMAr. The present results indicate that a large portion of the prefrontal signals from area 46 is not directly conveyed to the pre-SMA and CMAr, but rather indirectly by way of the PMdr and PMvr. This suggests that area 46 exerts its major influence on the cortical motor system via these premotor areas.

Animals↗
PubMed2001

Metabolic activation of carcinogenic 1-nitropyrene by human cytochrome P450 1B1 in Salmonella typhimurium strain expressing an O-acetyltransferase in SOS/umu assay.

Metabolic activation of 1-nitropyrene (1-NP) by human cytochrome P450 (P450) family 1 enzymes co-expressed with NADPH-cytochrome P450 reductase (NPR) in Escherichia coli membranes was investigated. 1-NP induced umu gene expression in Salmonella typhimurium TA1535/pSK1002 in the absence of any P450 system, but the activities were influenced by the levels of bacterial O-acetyltransferase (OAT) and nitroreductase. Metabolic activation of 1-NP by human P450 1B1/NPR membranes was observed and was influenced by the levels of OAT levels in tester strains. Metabolic activation of 1-NP (0.3microM) by P450 1B1 was 750 umu units/min/nmol P450 1B1 in an OAT-overexpressing strain NM2009. The metabolic activation of 1-NP (3-30microM) was similar (approximately 300 umu units/min/nmol P450 1B1) using TA1535/pSK1002 or OAT-deficient strain NM2000. P450 1B1 had the highest catalytic activities among P450 family 1 enzymes for the activation of 1-aminopyrene (1-AP) in the OAT-overexpressing strain NM2009, suggesting nitrenium ion formation via N-hydroxylation/O-acetylation. High-performance liquid chromatography (HPLC) analyses revealed the formation of 1-nitropyrene-6-ol and also 1-nitropyrene-3-ol, 1-nitropyrene-8-ol, and trans-4,5-dihydroxy-4,5-diol-1-nitropyrene from 1-NP (10microM), catalyzed by P450 1B1. These results indicate that 1-NP can be activated by human P450 1B1 to a genotoxic agent by nitroreduction/O-acetylation at low substrate concentrations and probably by epoxidation (independent of OAT) at high concentrations.

Acetyltransferases↗
PubMed2001

Distribution of median, ulnar and radial motoneurons in the monkey spinal cord: a retrograde triple-labeling study.

Topographic distribution of motoneurons innervating hand muscles through the median (Mn), ulnar (Ul), or radial (Rd) nerves was examined using a retrograde multiple-labeling technique in the macaque monkey. The Mn and Ul motoneurons, i.e. flexor motoneurons, were distributed from C6 to T2 and from C7 to T2 segments of the spinal cord, respectively, while the Rd motoneurons, i.e. extensor motoneurons, were distributed from C4 to T2. The present study further revealed partial intermingling of the cell bodies and partial overlap of the dendritic fields among the motoneurons projecting through different nerves, indicating that subregions of motoneuronal pool participate in coordination between the flexor and extensor, or among the flexor muscles. It was suggested that there exists a control mechanism for precise hand movements in the spinal cord.

Animals↗
PubMed2001

Somatotopic arrangement and corticocortical inputs of the hindlimb region of the primary motor cortex in the macaque monkey.

Using Japanese monkeys, we examined the somatotopic organization of the hindlimb region of the primary motor cortex (MI) with intracortical microstimulation. In the hindlimb region of the MI, areas representing distal movements (digits and ankle joints) were basically surrounded by those representing proximal movements (knee and hip joints). Thus, the hindlimb region of the MI has a nested or horseshoe-like somatotopic representation. We then examined the topographic organization of corticocortical projections to the hindlimb region of the MI by the retrograde double-labeling technique: one monkey received paired injections of Fast blue (FB) and Diamidino yellow (DY) into hindlimb or forelimb representation of the MI, respectively, while two monkeys received those of FB and DY into proximal or distal representation of the hindlimb region of the MI, respectively. The neurons projecting to the hindlimb region of the MI were located in cortical areas largely separate from those projecting to the forelimb region of the MI. On the other hand, we found a substantial overlap of corticocortical neurons projecting to the proximal and distal parts of the hindlimb region of the MI in the dorsal division of the premotor cortex and the cingulate motor areas.

Animals↗
PubMed2001

Organization of inputs from cingulate motor areas to basal ganglia in macaque monkey.

The cingulate motor areas reside within regions lining the cingulate sulcus and are divided into rostral and caudal parts. Recent studies suggest that the rostral and caudal cingulate motor areas participate in distinct aspects of motor function: the former plays a role in higher-order cognitive control of movements, whereas the latter is more directly involved in their execution. Here, we investigated the organization of cingulate motor areas inputs to the basal ganglia in the macaque monkey. Identified forelimb representations of the rostral and caudal cingulate motor areas were injected with different anterograde tracers and the distribution patterns of labelled terminals were analysed in the striatum and the subthalamic nucleus. Corticostriatal inputs from the rostral and caudal cingulate motor areas were located within the rostral striatum, with the highest density in the striatal cell bridges and the ventrolateral portions of the putamen, respectively. There was no substantial overlap between these input zones. Similarly, a certain segregation of input zones from the rostral and caudal cingulate motor areas occurred along the mediolateral axis of the subthalamic nucleus. It has also been revealed that corticostriatal and corticosubthalamic input zones from the rostral cingulate motor area considerably overlapped those from the presupplementary motor area, while the input zones from the caudal cingulate motor area displayed a large overlap with those from the primary motor cortex. The present results indicate that a parallel design underlies motor information processing in the cortico-basal ganglia loop derived from the rostral and caudal cingulate motor areas.

Action Potentials↗
PubMed2001

Induction of cytochrome P450 1B1 in lung, liver and kidney of rats exposed to diesel exhaust.

We have shown previously that diesel exhaust particle (DEP) extracts (DEPE) and 1-nitropyrene were genotoxically activated by human cytochrome P450 1B1 in SOS/umu assay. In this study, the in vivo induction of P450 family 1 enzymes in rats by exposure to diesel exhaust was investigated with regard to mRNA levels, P450 enzyme content, drug oxidation activities in the microsomes and umu gene expression of typical P450 substrates and DEPE itself catalyzed by the microsomes. Male Fischer 344 rats (4 weeks old) were exposed to 0.3 and 3.0 mg/m(3) DEP for 12 h per day for 4 weeks; the former dose corresponded to the typical daily airborne particle concentration. The levels of mRNA of rat P450 1B1 and P450 1A1 in the lung and liver were significantly increased 1.1-1.4-fold by exposure to 0.3 mg/m(3) DEP. Diesel exhaust particle extracts induced umu gene expression in Salmonella typhimurium TA1535/pSK1002 in the absence of a functional P450 system and were further activated by human recombinant P450 1B1. Using an O-acetyltransferase overexpressing Salmonella strain, genotoxic activation of P450 1B1 marker chemicals (1-nitropyrene, 1-aminopyrene and DEPE) by lung, liver and kidney microsomes was increased 1.7-4.2-, 1.4-1.5- and 1.0-1.3-fold, respectively, by exposure to 0.3 mg/m(3) DEP. Activation of 3-amino-1,4-dimethyl-5H-pyrido [4,3-b]indole (Trp-P-1; marker for P450 1A1) by lung microsomes and the P450 1A2 content in liver microsomes were slightly increased by exposure to 3.0 mg/m(3) DEP. This is the first report to suggest that typical daily contaminant levels (0.3 mg particle/m(3)) of diesel exhaust can induce P450 1B1 in rats and that the induced P450 1B1 may catalyze the genotoxic activation of DEP.

Animals↗
PubMed2000

Bioactivation of diesel exhaust particle extracts and their major nitrated polycyclic aromatic hydrocarbon components, 1-nitropyrene and dinitropyrenes, by human cytochromes P450 1A1, 1A2, and 1B1.

The genotoxicities of four samples of diesel exhaust particle (DEP) extracts (DEPE) and nine nitroarenes found in DEPE were investigated after activation catalyzed by human cytochrome P450 (P450) family 1 enzymes co-expressed with NADPH-cytochrome P450 reductase (NPR) in Escherichia coli membranes. The DEPE samples induced umu gene expression in Salmonella typhimurium TA1535/pSK1002 without any P450 system and were further activated by human P450 1B1/NPR membranes. Moderate activation of the DEPE sample by P450 1A2/NPR membranes was also observed, but not by either P450 1A1/NPR or NPR membranes. 1-Nitropyrene (1-NP) was strongly activated by human P450 1B1/NPR membranes. 1,8-Dinitropyrene (1,8-DNP) was most highly activated by P450 1A1 and 1B1 systems for the three DNPs tested. In contrast, 1, 3-DNP was inactivated by P450 1A1/NPR, 1A2/NPR, and 1B1/NPR systems and slightly activated by NPR membranes. 2-Nitrofluoranthene (2-NF) and 3-nitrofluoranthene (3-NF) showed activities similar to 1-NP after bioactivation by P450 1B1/NPR membranes. However, the genotoxicities of 6-nitrochrysene, 7-nitrobenz[a]anthracene, and 6-nitrobenzo[a]pyrene were all weak in the present assay system. Apparent genotoxic activities of DEPE were very low compared with standard nitroarenes in the presence of P450s, possibly because unknown component(s) of DEPE had inhibitory effects on the bioactivation of 1-NP and 1,8-DNP catalyzed by human P450 1B1. These results suggest that environmental chemicals existing in airborne DEP, in addition to 1-NP, 1,6-DNP, 1,8-DNP, 2-NF, and 3-NF, can be activated by human P450 1B1. Biological actions of air pollutants such as nitroarenes to human extrahepatic tissues may be of concern in tissues in which P450 1B1 is expressed.

Aryl Hydrocarbon Hydroxylases↗
PubMed2000

A cortical motor region that represents the cutaneous back muscles in the macaque monkey.

A cortical motor region that represented the cutaneous muscles on the back was identified on the medial wall of the frontal lobe in the macaque monkey. In this region, neurons responded to somatosensory stimuli such as light touch or squeezing of the back skin, and intracortical microstimulation elicited contraction of the back skin. Such a region was located primarily on the dorsal bank of the cingulate sulcus, corresponding to the dorsal cingulate motor area.

Animals↗
PubMed2000

Direct projections from the magnocellular division of the basal nucleus of the amygdala to the principal part of the cortical masticatory area in the macaque monkey.

Direct projections from the amygdala to the cortical masticatory area were found in the macaque monkey. Under the guidance of intracortical microstimulation, retrograde tracers were injected into multiple jaw movement-related regions of the frontal lobe. The cortical masticatory area, especially its principal part, stimulation of which elicited rhythmic jaw movement, was the only site of injection that produced neuronal labeling in the amygdala. The cells of origin of such projections were localized in the medial aspect of the magnocellular division of the basal nucleus through its rostral level. No labeled neurons were observed in the amygdala after tracer injection into any other cortical jaw movement-related region. The present results suggest that the amygdaloid input to the cortical masticatory area may exert some modulatory influence on the generation of masticatory rhythm.

Amygdala↗
PubMed2000

B-mode and color Doppler ultrasound imaging for localization of microelectrode in monkey brain.

Using alert monkeys, we attempted ultrasound imaging after partial craniotomy to localize a metal microelectrode in the brain. B-mode ultrasonography provided images of sulcus and gyrus patterns of the cerebral cortex, and locations of the ventricles and subarachnoid cisterns. As the microelectrode proceeded in the brain, the position of the microelectrode was clearly identified. Electrolytic microlesions generated by delivering direct currents via the microelectrode could also be detected. Color Doppler imaging of blood vessels of the brain was helpful to demarcate deep brain structures and to avoid accidental injury of the blood vessels by the microelectrode. The ultrasonography will make it possible to place recording microelectrodes or injection needles accurately in target regions of the brain in physiological, anatomical or behavioral experiments.

Animals↗
PubMed2000

Selenium kinetics and changes in glutathione peroxidase activities in patients receiving long-term parenteral nutrition and effects of supplementation with selenite.

Selenium (Se) is an essential trace element in humans. Patients receiving long-term parenteral nutrition (PN) are at risk for Se deficiency. We investigated changes in Se levels and glutathione peroxidase (GSH-Px) activity in serum and tissue (red blood cells, RBC) in addition to urinary excretion of Se in patients receiving long-term PN with and without Se supplementation. In patients without Se supplementation, both Se levels and GSH-Px activity in serum decreased with duration of PN. The serum Se levels were below the lower limits of the control values in 19 of 33 patients (58%) who received PN for less than 1 mo. Conversely, RBC GSH-Px activity remained at a sufficient level in 9 of 12 patients (75%) who received PN for 3-6 mo. The RBC Se levels in all of these patients were lower than the control levels. Urinary Se concentrations were significantly correlated with serum Se concentrations by linear regression analysis (r = 0.707, P < 0.05). In patients with Se supplementation, urinary Se concentrations increased exponentially with increases in serum Se levels. These findings indicate that a time lag precedes the decrease in levels of serum Se, RBC Se, serum GSH-Px, and RBC GSH-Px in patients without Se supplementation and the increase in excretion of urinary Se in patients with Se supplementation. The monitoring of not only serum Se levels but also RBC GSH-Px activity and urinary Se levels is required for optimal Se supplementation during long-term PN.

Adolescent↗
PubMed2000

[A patient with dysphagia treated successfully and discharged without nutritional support].

One of the main targets of medical care provided in our ward, which specializes in the cooperative practice of hospital- and home-doctors, is to maintain the quality of patients' lives after they are discharged from our hospital through home medical care by home-doctors. Intravenous hyperalimentation and tube-feeding at home are suitable solutions for some patients with dysphagia after cerebral infarction. However, the difficulties faced in their management are the burden on the families, which tends to be an obstacle for at-home-practice. We describe herein a case of severe dysphagia treated successfully through our rehabilitation program and discharged without nutritional supports. An 82-year-old man was admitted to our hospital suffering from pyrexia and dysbasia. The man, who lives with his wife and his son's family, was diagnosed with aspiration pneumonia and multiple cerebral infarctions. The test for swallowing reflex revealed an impaired first phase reflex and intravenous hyperalimentation was performed for his nutritional support. He was still suffering from dysphagia but had the desire to eat orally after his dysbasia and aspiration pneumonia were cured. A rehabilitation program was scheduled with the aims of 1) recovery of ingestion and 2) sufficient expectoration, with an ongoing teaching program for the management of intravenous hyperalimentation. After one month of rehabilitation (ice-massaging, muscle rehabilitation of the tongue and neck and expectoration training in a prone position and after gorging), his ability to swallow was gradually recovered. With the frequent confirmation of absence of aspiration, special forms of diets were served and upgraded from jelly, paste-like-food to soft-cooked steamed rice. The patient is now at home without any nutritional support. Nutritional management without intravenous hyperalimentation or tube-feeding is important or even essential for some families providing home-care for patients. The problem of aging requires us to reduce the burden that families (who may be also getting older) should carry. We try to support patients and families for better home-care through cooperation with society and home-doctors.

Aged↗
PubMed1998

[Mediastinal bronchogenic cyst associated with high serum level of CA19-9--a surgical case report].

We reported a case of mediastinal bronchogenic cyst in a patient with a high serum level of CA19-9. The patient, a 41-year-old man, presented with a complaint of persistent fever. Chest X-ray examination, computed tomography and magnetic resonance imaging showed a subcarinal mass shadow which was diagnosed preoperatively as a bronchogenic cyst. The serum level of CA19-9 was 73 U/ml. The cyst was partially removed via right thoracotomy. Histopathological findings were compatible with bronchogenic cyst. The CA19-9 level in the specimen was 134,00 U/ml. The serum level of CA19-9 decreased to normal postoperatively. The postoperative course was uneventful.

Adult↗
PubMed1998

[Mediastinoscopic diagnosis and drainage of pericardial diverticulum--a case report].

A 38-year-old male was suspected of having an enlarged pretracheal lymph node on chest CT scan. At mediastinoscopy, a cystic lesion was recognized, and showed repeated dilatation and contraction synchronously with the cardiac beat. Pneumopericardium was demonstrated by intraoperative pneumocystography. The cystic lesion was diagnosed as pericardial diverticulum. The diverticular wall was partially resected for drainage of the pericardial fluid. Mediastinoscopy as a less invasive procedure may be useful for the differential diagnosis of adenopathies, and in case of lesion such as a small pericardial diverticulum may allow treatment.

Adult↗
PubMed1998

[A successfully treated case of empyema with a large tracheal fistula after subtotal esophagotomy by mediastinoscopy].

We reported a successfully treated case of empyema with a large tracheal fistula after subtotal esophagotomy. This 59-year-old male was treated by drainage with mediastinoscopy and repeated wash-out under bronchoscopy, because we could not use the omentum and he was the poor-risk patient. The trancheal fistula was obliterated bronchoscopically, 4 months after the mediastinoscopy. We believe that this method (abscess drainage with mediastinoscope and wash-out repeatedly) is useful for those who has broncheal fistula after esophagectomy.

Bronchial Fistula↗
PubMed1998

[Mediastinoscopic drainage for descending necrotizing mediastinitis].

A case of descending necrotizing mediastinitis that was treated by mediastinoscopic drainage is reported. The patient was a 56-year-old diabetic woman. A hypopharyngeal abscess extended to the mediastinum through the neck. No septic condition was noted. Chest CT showed that the abscess reached 4 cm below the tracheal bifurcation. Pus was drained under direct observation by mediastinoscopy, and a drain was placed in an appropriate position. After operation, lavage was performed through the drain, and cure was achieved on the 42nd postoperative day. This technique should be considered as surgical treatment for descending necrotizing mediastinitis in the absence of serious complication such as sepsis, because it has a more reliable drainage effect than the conventional transcervical method, and because it is less invasive than thoracotomy.

Drainage↗