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Biomedical subjects

S Matsuoka

Publications and source records attributed to S Matsuoka.

At least 37 records · Page 2Linked to original sources
PubMed2001

Positivity of extrapulmonary Ga-67 uptake in sarcoidosis: thyroid uptake due to chronic thyroiditis and bone uptake due to fibrous dysplasia.

Ga-67 citrate scintigraphy was performed on a 29-year-old man who had been diagnosed as having pulmonary sarcoidosis by a transbronchial lung biopsy. A Ga-67 citrate scintigram showed increased uptake not only in the pulmonary hilum and mediastinum, but also in the thyroid gland and the right ilium. Chronic thyroiditis was confirmed by aspiration biopsy of the thyroid gland, and fibrous dysplasia was confirmed by CT guided biopsy of the right ilium. Extrapulmonary Ga-67 uptake in patients with sarcoidosis does not necessarily indicate the involvement of other tissues and organs.

Adult↗
PubMed2001

Unusual early bile excretion from the liver in patients with fulminant hepatic failure as detected by Tc-99m-PMT hepatobiliary scintigraphy; comparison with Tc-99m-GSA scintigraphy.

In two females (58 and 14 years old) with fulminant hepatic failure, Tc-99m-PMT hepatobiliary scintigraphy was used to evaluate intrahepatic bile stagnation, and Tc-99m-GSA scintigraphy to evaluate hepatic functional reserve. In both patients, Tc-99m-PMT hepatobiliary scintigraphy showed unusual early bile excretion into the extrahepatic bile duct and small intestine within the first 30 min of imaging. These findings contradicted typical findings of intrahepatic bile stagnation of fulminant hepatic failure. The receptor index and blood clearance index determined from dynamic acquisition data on Tc-99m-GSA scintigraphy suggested a markedly decreased hepatic functional reserve. These findings were compatible with fulminant hepatic failure. A discrepancy was observed between the findings of hepatobiliary scintigraphy and those of Tc-99m-GSA scintigraphy. The pathological state of early bile excretion from the liver into the bile duct should be considered in fulminant hepatic failure.

Adolescent↗
PubMed2001

Functioning adrenal black adenoma with pulmonary and cutaneous cryptococcosis: a case report and review of English literature.

A 53-year-old woman experienced progressive general weakness and lumbago in the 2 years prior to a physical examination which disclosed cushingoid manifestations and a skin ulcer on the back of her right knee joint. Her plasma cortisol concentration ranged from 24.7 to 31.1 microg/dl, with an ACTH level <5 pg/ml. Urinary excretions of 17-hydroxycorticosteroid (17-OHCS) and 17-ketosteroid (17-KS) were 20.5 mg/day and 5.1 mg/day, respectively, and urinary cortisol was also increased (421 microg/day). Cortisol was not suppressed after the administration of 8 mg dexamethasone. Abdominal ultrasound sonography, computed tomography (CT) scan, and magnetic resonance imaging (MRI) studies demonstrated a left adrenal tumor and further, a chest X-ray examination showed a cavitary lesion containing a fungus ball-like mass in the left lower lung field. The serum cryptococcal antigen titer was positive at 1:128 and a bronchoalveolar lavage fluid culture yielded a growth of Cryptococcus neoformans. A biopsy specimen of the skin ulcer also suggested cryptococcosis. As a result, a left adrenectomy was performed, and the excised specimen was shown to be an adenoma consisting of compact cells with abundant pigmentation (black adenoma). A diagnosis of functioning black adenoma of the adrenal gland, complicated with pulmonary and cutaneous cryptococcosis was made.

Adrenal Gland Neoplasms↗
PubMed2001

The crystal structure of the complex of non-peptidic inhibitor of human neutrophil elastase ONO-6818 and porcine pancreatic elastase.

The crystal structure of a new inhibitor of human neutrophil elastase (HNE), N-[2-[5-(tert-butyl)-1,3,4-oxadiazol-2-yl]-(IRS)-1-(methylethyl)-2-oxoethyl]-2-(5-amino-6-oxo-2-phenyl-6H-pyrimidin-1-ly)acetamide (ONO-6818, 1) complexed to porcine pancreatic elastase (PPE) has been determined at 1.86 A resolution. Analytical results provided evidence of a 1:1 complex in which the electrophilic ketone of 1 covalently bound to O gamma of Ser195 at the active site of PPE. The role of the unique electron-withdrawing ketone of 1 has been elucidated.

Animals↗
PubMed2001

Intense immunosuppression followed by purified blood CD34+ cell autografting in a patient with refractory juvenile rheumatoid arthritis.

A 15-year-old boy with refractory juvenile rheumatoid arthritis (JRA) underwent intense immunosuppressive therapy followed by purified blood CD34+ cell autografting. He had been taking prednisolone (PDN) daily or every other day combined with methotrexate once a week to control the disease for 7 years. He suffered from psychological complications and a very short stature due to the adverse effects of these drugs. CD34+ cells were purified in bulk from G-CSF-mobilized PBSC using an Isolex 300. After the administration of cyclophosphamide (200 mg/kg) and anti-lymphocyte globulin (45 mg/kg), 3.6 x 10(6)/kg purified CD34+ cells were infused. His post-transplant course was uneventful except for herpes-zoster infection. He is now more than 1 year post transplant and has not taken any immunosuppressive medication. His rate of growth has increased (>10 cm/year) due to the effects of the cessation of PDN and the administration of recombinant human growth hormone (rGH), in contrast to the gain of 2 cm in the preceding 3 years with rGH treatment. Although the durability of this remission is unknown, intense immunosuppressive therapy followed by purified blood CD34+ cell autografting might be acceptable for adolescent patients with refractory JRA to achieve a drug-free period for physical and psychological maturation.

Adolescent↗
PubMed2001

Sleep patterns during 30-m nitrox simulated saturation dives.

The sleep patterns were examined during the simulated 30-m nitrox saturation dives. The standard polysomnography of 15 divers was recorded for a total of 255 nights, as were patterns of change or consistency in sleep variables. A reduction of total sleep time in accordance with the lengthening of sleep latency and the wake after sleep onset was observed through the latter part of the bottom period to the post-dive period, but the other sleep variables did not show any changes. These findings suggest that decompression and the psychological stress due to being in the closed environment of a hyperbaric chamber for a long time have effects on divers' sleep.

Adult↗
PubMed2001

[Estimation of daily dietary intake of aluminum].

The daily dietary intake of aluminum was estimated through a total diet study from 1996 to 1998. In ten institutes, total diet study samples were prepared and their aluminum concentration was determined. The average daily intake of aluminum was 3.5 mg and the range was 1.8-8.4 mg. The validity of the analytical result was supported by analyses of certified reference materials.

Aluminum↗
PubMed2001

[A juvenile case of locked-in syndrome living long after pontine infarction].

A juvenile case of locked-in syndrome (LiS) caused by pontine infarction was reported. A 26-year-old woman suddenly complained of speech disturbance, weakness of the left upper and lower limbs, and occipital headache. She was admitted to an emergency hospital. Magnetic resonance imaging (MRI) showed a high intensity area on T2-weighted image at the ventral portion of the pons. She was transferred to our hospital for further treatment. On admission, she was mute and quadriplegic, but responded to our questions with vertical eye movements and blinks. Vertebral and carotid angiography demonstrated complete occlusion of the basilar artery between the bilateral superior cerebellar artery and the bilateral anterior inferior cerebellar artery. As she was able to move her head, she began training to use a personal computer equipped with a special device as a communication tool. Three years from the onset, she stays at her home, takes her favorite foods, and enjoys her life.

Adult↗
PubMed2000

Regulation kinetics of Na+-Ca2+ exchange current in guinea-pig ventricular myocytes.

To investigate the regulation of native cardiac Na+-Ca2+ exchange by cytoplasmic Na+ (Na+i) and Ca2+ (Ca2+i), we recorded the Na+-Ca2+ exchange current (INa-Ca) from inside-out 'macro patches' excised from intact guinea-pig ventricular cells. The half-maximal concentration (Kh) of Ca2+i required to induce an inward INa-Ca was 7 µM. The Kh of Na+i required to induce an outward INa-Ca was 21 mM, and tended to decrease at the steady state of Na+-dependent inactivation. The time constant (tau) of Na+-dependent inactivation was ~1.5 s at 100 mM Na+i and 1 µM Ca2+i. The Kh for Na+i was 14 mM. Ca2+i augmented the peak outward INa-Ca (Kh = 0.2 µM) and attenuated Na+-dependent inactivation (Kh = 2.2 µM). The outward INa-Ca was activated by 5 µM Ca2+i with a half-time to reach steady state (t½) of ~0.4 s. This activation was composed of two exponential processes. Deactivation of the current upon Ca2+i removal also consisted of two exponential processes and had a t½ of ~0.5 s. A Na+-Ca2+ exchange model, consisting of one consecutive 4Na+:1Ca2+ exchange cycle and two inactive states, well mimicked the experimental data with regard to ion dependencies and regulation kinetics. These data provide detailed information on the kinetics of the Na+i- and Ca2+i-dependent regulation of native Na+-Ca2+ exchange. They also indicate that the regulation kinetics operate faster in macro patches than in the giant membrane patch from cardiac 'blebs', or in Xenopus oocytes expressing a cloned exchanger (NCX1.1).

Journal Article↗
PubMed2000

Regulation kinetics of Na+-Ca2+ exchange current in guinea-pig ventricular myocytes.

To investigate the regulation of native cardiac Na+-Ca2+ exchange by cytoplasmic Na+ (Na+i) and Ca2+ (Ca2+i), we recorded the Na+-Ca2+ exchange current (INa-Ca) from inside-out 'macro patches' excised from intact guinea-pig ventricular cells. The half-maximal concentration (Kh) of Ca2+i required to induce an inward INa-Ca was 7 microM. The Kh of Na+i required to induce an outward INa-Ca was 21 mM, and tended to decrease at the steady state of Na+-dependent inactivation. The time constant (tau) of Na+-dependent inactivation was approximately 1.5 s at 100 mM Na+i and 1 microM Ca2+i. The Kh for Na+i was 14 mM. Ca2+i augmented the peak outward INa-Ca (Kh = 0. 2 microM) and attenuated Na+-dependent inactivation (Kh = 2.2 microM). The outward INa-Ca was activated by 5 microM Ca2+i with a half-time to reach steady state (t1/2) of approximately 0.4 s. This activation was composed of two exponential processes. Deactivation of the current upon Ca2+i removal also consisted of two exponential processes and had a t1/2 of approximately 0.5 s. A Na+-Ca2+ exchange model, consisting of one consecutive 4Na+:1Ca2+ exchange cycle and two inactive states, well mimicked the experimental data with regard to ion dependencies and regulation kinetics. These data provide detailed information on the kinetics of the Na+i- and Ca2+i-dependent regulation of native Na+-Ca2+ exchange. They also indicate that the regulation kinetics operate faster in macro patches than in the giant membrane patch from cardiac 'blebs', or in Xenopus oocytes expressing a cloned exchanger (NCX1.1).

Animals↗
PubMed2000

Ataxia telangiectasia-mutated phosphorylates Chk2 in vivo and in vitro.

The protein kinase Chk2, the mammalian homolog of the budding yeast Rad53 and fission yeast Cds1 checkpoint kinases, is phosphorylated and activated in response to DNA damage by ionizing radiation (IR), UV irradiation, and replication blocks by hydroxyurea (HU). Phosphorylation and activation of Chk2 are ataxia telangiectasia-mutated (ATM) dependent in response to IR, whereas Chk2 phosphorylation is ATM-independent when cells are exposed to UV or HU. Here we show that in vitro, ATM phosphorylates the Ser-Gln/Thr-Gln (SQ/TQ) cluster domain (SCD) on Chk2, which contains seven SQ/TQ motifs, and Thr68 is the major in vitro phosphorylation site by ATM. ATM- and Rad3-related also phosphorylates Thr68 in addition to Thr26 and Ser50, which are not phosphorylated to a significant extent by ATM in vitro. In vivo, Thr68 is phosphorylated in an ATM-dependent manner in response to IR, but not in response to UV or HU. Substitution of Thr68 with Ala reduced the extent of phosphorylation and activation of Chk2 in response to IR, and mutation of all seven SQ/TQ motifs blocked all phosphorylation and activation of Chk2 after IR. These results suggest that in vivo, Chk2 is directly phosphorylated by ATM in response to IR and that Chk2 is regulated by phosphorylation of the SCD.

Amino Acid Sequence↗
PubMed2000

Evaluation of arid region browse species from north eastern Nigeria using pen fed goats.

Four 18-26 months old castrated Borno whitexSokoto Red goats were used in a 4x4 Latin square design to measure the dry matter intake (DMI), daily body weight change and dry matter digestibility (DMD) of four native Nigerian browse species, (Ziziphus spinochrist, Wild., Acacia albida, Del., Sterculia satigera, Guill. and Anogeissus licocarpus, Guill.) native to the semi-arid regions. The mean DMI of Z. spinochrist, Wild. and A. albida, Del. were similar but higher than for S. satigera, Guill. and A. licocarpus, Guill. The DMD of A. licocarpus,Guill. was lower (p<0.05) than for Z. spinochrist, Wild., Acacia licocarpus, Del. or S. satigera, Guill. The lowest body weight gain recorded was for A. licocarpus, Guill.; this was attributed to the larger amount of fibre in the forage resulting in a slow rate of cell wall degradation and rumen digestibility. Goats showed no visual signs of toxicosis. This study suggests that A. albida, Del. has the highest forage value for goats followed by Z. spinochrist, Wild., S. satigera, Guill. and A. licocarpus, Guill. Potentially the species examined can provide feed for goats as well as for other small ruminants during long dry periods when other feed is unavailable.

Journal Article↗
PubMed2000

Chk1 is an essential kinase that is regulated by Atr and required for the G(2)/M DNA damage checkpoint.

Chk1, an evolutionarily conserved protein kinase, has been implicated in cell cycle checkpoint control in lower eukaryotes. By gene disruption, we show that CHK1 deficiency results in a severe proliferation defect and death in embryonic stem (ES) cells, and peri-implantation embryonic lethality in mice. Through analysis of a conditional CHK1-deficient cell line, we demonstrate that ES cells lacking Chk1 have a defective G(2)/M DNA damage checkpoint in response to gamma-irradiation (IR). CHK1 heterozygosity modestly enhances the tumorigenesis phenotype of WNT-1 transgenic mice. We show that in human cells, Chk1 is phosphorylated on serine 345 (S345) in response to UV, IR, and hydroxyurea (HU). Overexpression of wild-type Atr enhances, whereas overexpression of the kinase-defective mutant Atr inhibits S345 phosphorylation of Chk1 induced by UV treatment. Taken together, these data indicate that Chk1 plays an essential role in the mammalian DNA damage checkpoint, embryonic development, and tumor suppression, and that Atr regulates Chk1.

Alleles↗
PubMed2000

DNA damage-induced activation of p53 by the checkpoint kinase Chk2.

Chk2 is a protein kinase that is activated in response to DNA damage and may regulate cell cycle arrest. We generated Chk2-deficient mouse cells by gene targeting. Chk2-/- embryonic stem cells failed to maintain gamma-irradiation-induced arrest in the G2 phase of the cell cycle. Chk2-/- thymocytes were resistant to DNA damage-induced apoptosis. Chk2-/- cells were defective for p53 stabilization and for induction of p53-dependent transcripts such as p21 in response to gamma irradiation. Reintroduction of the Chk2 gene restored p53-dependent transcription in response to gamma irradiation. Chk2 directly phosphorylated p53 on serine 20, which is known to interfere with Mdm2 binding. This provides a mechanism for increased stability of p53 by prevention of ubiquitination in response to DNA damage.

Animals↗
PubMed2000

Stoichiometry of Na+-Ca2+ exchange in inside-out patches excised from guinea-pig ventricular myocytes.

1. The stoichiometry (nx) of cardiac Na+-Ca2+ exchange was examined by measuring the reversal potential of the Na+-Ca2+ exchange current (INa-Ca) in large inside-out patches, 'macro patches', excised from intact guinea-pig ventricular cells. 2. Cytoplasmic application of Na+ (Na+i) or Ca2+ (Ca2+i) induced INa-Ca which showed properties similar to INa-Ca in the giant membrane patch. The outward INa-Ca was depressed by an exchanger inhibitory peptide, XIP. 3. The reversal potential of the XIP-sensitive current indicated that nx was approximately 4 (3.6-4.2) at 9-40 mM Na+i, and nx tended to increase as Na+i was increased. Proteolysis by trypsin did not significantly affect the stoichiometry. Similar results were obtained from the reversal potential of INa-Ca that was induced by application of both Na+i and Ca2+i. 4. At 0.1 microM Ca2+i, nx was approximately 4 (3.7-4. 4) at 6-25 mM Na+i and tended to increase as Na+i was increased. When Ca2+i was changed from 0.1 to 1 and 1000 microM at constant 50 mM Na+i, the value was approximately 4 (3.6-4.4). 5. When the extracellular Na+ (Na+o) and Ca2+ (Ca2+o) concentrations were varied in the presence of 25 or 9 mM Na+i and 1 microM Ca2+i, nx was almost constant ( approximately 4) over the range 0.3-20 mM Ca2+o and 10-145 mM Na+o. 6. These results indicated that the stoichiometry of Na+-Ca2+ exchange is different from generally accepted 3Na+:1Ca2+, and suggested that the stoichiometry is either 4Na+:1Ca2+ or variable depending on Na+i and Ca2+i.

Animals↗
PubMed2000

Absent circadian variation of blood pressure in patients with anorexia nervosa.

OBJECTIVE: To examine whether circadian rhythm of blood pressure (BP) is altered in patients with anorexia nervosa (AN), and if so, to determine whether it is reversible after refeeding. STUDY DESIGN: Ambulatory BP monitoring was performed on 17 female inpatients with AN (mean age, 13.3 +/- 1.9 years) at the time of admission and serially during refeeding; 17 age-matched normal weight, normotensive female inpatients served as control subjects. RESULTS: Patients with AN had lost an average of 23.4% +/- 11.5% of body weight before the illness. Weight after refeeding was 105.6% +/- 9. 2% of that before illness. Mean 24-hour systolic BP (SBP) (96.5 +/- 8.6 mm Hg) and diastolic BP (DBP) (53.4 +/- 5.8 mm Hg) were significantly lower in patients with AN compared with those of control subjects (SBP, 106.1 +/- 6.5 mm Hg; DBP, 60.2 +/- 5.8 mm Hg). Although awake SBP and DBP were also lower in patients with AN, asleep SBP and DBP were not statistically different from those of control subjects. Night/day BP ratio in the control group was 0.93 +/- 0.06 in systolic and 0.92 +/- 0.09 in diastolic. Those values were significantly elevated in patients with AN (systolic 1.00 +/- 0. 09 and diastolic 1.00 +/- 0.09). After refeeding, the ratio decreased to 0.88 +/- 0.09 and 0.90 +/- 0.08,respectively (both P <. 05 vs baseline). CONCLUSIONS: In patients with AN, circadian variation of BP is absent. This reverts to normal after refeeding.

Adolescent↗
PubMed2000

Risk-adapted pre-emptive therapy for cytomegalovirus disease in patients undergoing allogeneic bone marrow transplantation.

We prospectively evaluated a risk-adapted pre-emptive treatment with ganciclovir for CMV diseases in patients undergoing allogeneic bone marrow transplantation (BMT). High-level CMV antigenemia (10 or more positive cells on two slides) or CMV antigenemia at any level in patients with grade II-IV acute graft-versus-host disease (aGVHD) were chosen as risk factors. We also retrospectively evaluated virus reactivation in plasma using quantitative real-time polymerase chain reaction (PCR). Fifty patients were evaluable. None of the 27 patients with or without grade I aGVHD developed high-level CMV antigenemia or CMV disease. Among the 23 patients with grade II-IV aGVHD, 12 patients (52%) developed CMV antigenemia and were treated pre-emptively, of whom two developed CMV gastroenteritis or retinitis in spite of therapy. Six of the remaining 11 patients developed CMV gastroenteritis before CMV antigenemia was detectable. All of the eight patients with CMV diseases were successfully treated with ganciclovir and no deaths directly related to CMV disease occurred. In four of the seven evaluable patients with CMV gastroenteritis, real-time PCR was able to detect virus reactivation earlier than CMV antigenemia. Although our risk-adapted pre-emptive therapy effectively reduced CMV-related mortality, further refinements of this approach, particularly in the prevention of CMV gastroenteritis, may be achieved by incorporating real-time PCR.

Adolescent↗