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Biomedical subjects

K Katoh

Publications and source records attributed to K Katoh.

At least 199 records · Page 11Linked to original sources
PubMed1991

[Examination medicine in the industrial health--aspects of biological monitoring].

The data of the health examinations for workers during the last few decades show two changes on the health level of labor. One is the reincrease of the prevalence rate of the detected diseases in the periodic health examinations (PHE) after once decrease, the other is the continuous decrease of the prevalence rate of the clinical findings owing to harmful work in the special health examinations (SHE). The first change requires us to consider the PHE as not only the mass screening method of the adult diseases but also the health-check to collect the information provided for the preparation and the evaluation of the health instruction by which the worker tries to promote his own health. The second change suggests that the SHE for the workers employed for harmful work should not be regarded hereafter as the screening method for the occupational diseases but as the biological monitoring for the exposure and the effect of the low level of the harmful compounds to workers. In the case of lead workers, for instance, the lead concentration in blood (B-Pb) and in urine (U-Pb) and the delta-amino levulinic acid in urine (U-ALA) are employed in SHE as the biological monitoring, and these have been considered to correlate well with the lead level in the air (A-Pb). However, A-Pb in workshops B-Pb, U-Pb and U-ALA level in the lead workers are decreasing year by year.(ABSTRACT TRUNCATED AT 250 WORDS)

Environmental Monitoring↗
PubMed1991

A case of glomerulocystic kidney disease associated with hypothyroidism in man.

Glomerulocystic kidney (GCK), a rare disease mostly seen in infants and small children, is characterized by dilatation of Bowman's space. We report about a 32-year-old Japanese male with GCK. Although radiologic studies including computed tomography of the kidneys failed to show cysts in the corticomedullary regions, renal biopsy specimens revealed diffuse glomerular cystic lesions. Extrarenal malformations were not determined, but the patient was found to have hypothyroidism presumably due to a functional disorder of the hypothalamus (tertiary hypothyroidism). This is probably the fifth documented case of the disease in an adult. To our best knowledge, the association with hypothyroidism is rare. Although its pathogenic relevance to GCK is unknown, the endocrine dysfunction seems to have occurred as part of the extrarenal conditions of GCK, which calls further attention to this entity.

Adult↗
PubMed1990

Mutations in the alpha 1 domain of a class I gene define residues important for specific allorecognition.

Our strategy to use saturation mutagenesis to produce an unbiased collection of major histocompatibility class I mutants has resulted in unpredicted mutant phenotypes. First, we have shown data supporting our earlier work of the Dp20(Y27N) mutant. Allorecognition is altered at the clonal level while no variation in lymphocytic choriomeningitis virus (LCMV)-restricted recognition is observed. The defect does not destroy the integrity of this class I protein on the basis of three observations: (i) LCMV self-restricted recognition is not impaired, (ii) beta 2 microglobulin still associates with Dp20(Y27N) at the cell surface, and (iii) this mutant can stimulate a primary MLR. Thus, we believe Dp20(Y27N) specifically affects allorecognition, perhaps by altering self peptide associations. The Dp14(A11V;E32Q) mutant appears to interact with T cell receptors (TCR) from a cloned cytotoxic T lymphocyte, but is altered in inducing a wild type signal into the responding cell. This is presumably due to decreased interaction at the cell surface between Dp14(A11V;E32Q) and wild type-specific TCR such that variations are detected in how a cell perceives extracellular signals. Analysis of additional mutants suggests that mutant Dp163(N66S) alters the binding site for monoclonal antibodies 7-16.10 and 135, while leaving unaltered the binding site for monoclonal antibodies 34-1.2 and 11-20.3. This maps the residue responsible for 7-16.10 and 135 binding to the region of Dp163(N66S).

Animals↗
PubMed1990

Effects of age on susceptibility of chickens to delayed neurotoxicity due to triphenyl phosphite.

Triphenyl phosphite (TPP), which is widely used in the chemical industry, is known to produce delayed neurotoxicity in some experimental animals. The effects of aging on the susceptibility to TPP, its disposition and pharmacokinetics, and its in vitro degradation by liver homogenate were studied in chickens. Chickens aged 60 days or less at administration were not affected, but 10 of 15 chickens aged 90 to 180 days developed ataxia 10 to 12 days after the intravenous injection of TPP (50 mg/kg). TPP clearance from the blood and most of the tissues examined was faster in 45-day-old chickens than in 135-day-old chickens. The biological half-life of TPP in the blood was 23.2 min. in the younger group and 30.5 min. in the older group. In the in vitro experiment, the initial TPP concentration of 1.6 x 10(-5) M fell to less than half this level within 60 min. during incubation with liver homogenates from 45-day-old chickens, whereas with homogenates from 135-day-old chickens the level remained high. These results suggested that the age-specific susceptibility to TPP was related to the differences of the tissue load, which derived in part from differing levels of metabolic activity in the liver.

Aging↗
PubMed1990

Blood pressure, obesity and urine cation excretion in two populations of the Cook Islands.

As part of a physical anthropological and linguistic research in the Cook Islands, blood pressure levels, the degree of obesity, and urine cation excretion were measured in the residents of Rarotonga (the most westernized) and Mangaia (a less westernized island) in 1986. The rise of blood pressure with age was observed in both sexes in each island, with the mean systolic pressures of the oldest male group (155.8 vs. 137.3 mmHg) significantly higher, and those of older female groups (137.4 vs. 127.1 and 154.7 vs. 145.9 mmHg) relatively higher in Rarotonga than in Mangaia. The mean body mass index was much the same between the two islands, but mean skinfolds at triceps and subscapular sites were thicker in Rarotonga than in Mangaia in each sex and age group. The mean sodium to potassium excretion ratio fell with age (2.97 to 0.94 in males, 2.24 to 1.09 in females) in Rarotonga, and was consistently low (1.09 to 0.73) in Mangaia. Body mass index correlated with both systolic and diastolic pressures in each sex and island group but indeces of sodium excretion did not. Obesity was considered a more important risk factor for hypertension than sodium-intake in the surveyed population, and skinfolds, related to daily physical activity, probably associated with the difference in blood pressure levels observed between the two islands.

Adolescent↗
PubMed1990

Hb Fukutomi [alpha 126(H9)Asp----Val]: a new hemoglobin variant with high oxygen affinity.

Hb Fukutomi [alpha 126(H9)Asp----Val], a new hemoglobin variant with a high affinity for oxygen (log P50 = 0.201 at pH 7.0, normal = 1.087) was detected in a Japanese male during a screening survey. The amino acid substitution is located in the alpha 1 beta 1 contact of the tetramic molecule. Like other variants of the high oxygen affinity type Hb Fukutomi showed increased resistance to auto-oxidation. The tryptic peptide alpha T-13, that usually forms part of the trypsin-resistant core of the alpha chain, was cleaved off by trypsin in the new variant and released into the soluble fraction.

Amino Acid Sequence↗
PubMed1990

Low-dose endothelin stimulates release of prostaglandin I2 from isolated perfused hind legs in the rat.

A direct measurement of 6-keto-prostaglandin F1a (6-keto-PGF1a), a stable metabolite of prostaglandin I2, was made in the perfusate from isolated rat hind legs perfused with Krebs-Ringer solution. The rate of release of 6-keto-PGF1a was 5.28 +/- 0.24 ng during the first perfusion period of two min, and it remained stable at least for 40 min. The biological integrity of the preparation was confirmed by inhibition (52%) of 6-keto-PGF1a release by indomethacin (5 X 10(-5) M) in the perfusion medium. Low-dose infusion (5, 10, and 20 pM, for 10 min each) of endothelin (ET) elicited small but significant increment in the release of 6-keto-PGF1a in a dose-dependent fashion; the maximal per cent increase of 6-keto-PGF1a release evoked by ET (20 pM) was approximately +40% over the basal rate. These results taken together with the previous observations of synthesis of ET in the vascular tissue suggest an intriguing relationship between vasoconstrictive ET and vasodilatory prostaglandins in the local control of vascular tone.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

[Digital plethysmogram in women with climacteric disturbance after cold-water challenge test and effect of estrogen].

Immediately after a cold-water challenge test (C-W test) the pulse height to the digital plethysmogram descended (descent wave: D wave), and a congestion wave (C wave) occurred after the D wave. Then the recovery wave (R wave) continued after the C wave. The effects of estrogen on the digital plethysmogram under the C-W test are as follows. (1) The D wave was less than 25% in young women and women without climacteric disturbance. (2) The recovery rate of the C wave in young women was better than in climacteric women without climacteric disturbance. (3) The before value for A1B'1/B'1C1 in the C-W test of young women was 1.0, and the other values during the C-W test did not change significantly compared with the before values. (4) U-time rose only temporarily in the former case. In addition the recovery rate of the R wave after the administration of premarin in women with climacteric disturbance was 19.3%, and this was a significant improvement over the cases without administration. The recovery rate of the R wave in the same women after the administration of premarin and cercine increased to 48.3% (p less than 0.01). These data suggested that estrogen may be able to control the function of the autonomic nervous system in climacteric woman.

Adolescent↗
PubMed1990

[Assessment of ischemic damage of the cardiac sympathetic nerve function by semiquantitative analysis of 123I-MIBG (metaiodobenzylguanidine)-SPECT--comparison with 201Tl-Cl-SPECT].

Recently 123I-MIBG scintigraphy has been developed for evaluating the function of cardiac sympathetic nerve. To assess its ischemic damage, dual SPECT with 123I-MIBG and 201Tl-Cl were performed in 24 patients with ischemic heart disease and 8 normal subjects. In order to evaluate extent and severity of ischemic damage, Tl and MIBG abnormal scores were calculated by Bull's eye map. In patients with Non-Q wave myocardial infarction (NQMI), MIBG abnormal scores were significantly higher than Tl scores (p less than 0.01). In the regions where regional wall motion showed hypokinesis, MIBG abnormalities were detected in all cases whereas Tl abnormalities existed only in 42%. MIBG abnormality score in NQMI group with negative T wave and wall motion asynergy was significantly higher than that of NQMI group without T wave abnormality and asynergy (p less than 0.01). Ischemic damage of cardiac sympathetic nerve seemed to contribute to negative T wave and stunned myocardium. 123I-MIBG scintigraphy was thought to be a sensitive and useful method for clinical evaluation of ischemic heart disease.

3-Iodobenzylguanidine↗
PubMed1990

[The anesthesiologist's role in the French emergency medical system].

The present system of French emergency medicine and its philosophy were described from my experience at SAMU (service d'aide medicale urgente). Three factors of emergency medicine; pre-hospital care, emergency transport and emergency information service are managed by anesthesiologists. Anesthesiologists on duty at the tele-medicine center give medical team instructions to start at once. The team is composed of an anesthesiologist, a nurse and an ambulancier. They start to give intensive care medicine to critically ill patients on the spot. The philosophy of SAMU is that doctors should go out of the hospital. Anesthesiologists in the area organize the emergency medical system in France.

Anesthesiology↗
PubMed1990

[Effects of cigarette smoking on I-123 IMP clearance from the lung].

N-isopropyl-p-I-123-iodoamphetamine (I-123 IMP), originally developed as a brain scanning agent, is also taken up by the lung. To evaluate the cigarette smoking on the uptake of IMP by the lung, we studied I-123 IMP clearance from the lung of 14 volunteers; 5 non-smokers and 9 smokers. After the injection of 111 MBq (3 mCi) of I-123 IMP into the medial cubital vein, the time-activity curve for 60 minutes and the regional activity using 1 frame per minute and a 64 x 64 matrix was obtained. I-123 IMP clearance curve was described as follows: C(t) = A1e-k1t + A2e-k2t (A1, A2: intercepts, and k1, k2: slopes of the exponential components). I-123 IMP clearance was delayed in smokers, and k2 was smaller in smokers. Also a significant correlations between k1, k2, and the number of cigarettes smoked per day were found. In conclusion, this study suggests that the delayed clearance and retention of I-123 IMP in the lung indicate the lung metabolic disorders due to cigarette smoking.

Adult↗
PubMed1990

[A case report of postoperative thyroid crisis accompanied with struma ovarii].

A 39-year-old female without any specific past history was scheduled to receive an operation for myoma uteri and ovarian cyst. She was premedicated with atropine. Anesthesia was induced with thiopental and was maintained with nitrous oxide and enflurane. Tachycardia shortly after premedication with atropine and remarkable sweat during the operation were observed. On the 1st postoperative day an outbreak of thyroid crisis as well tachycardia of 180.min-1 and fever (39.3 degrees C) were observed. Such outbreak of thyroid crisis indicated that the patient had been suffering from Grave disease. Pathological diagnosis of extirpated ovarian cyst was struma ovarii. It is, however, still uncertain whether struma ovarii induced thyroid crisis in this case. It might be concluded that screening of hyperthyroidism at preoperative rounds is essential for prevention of thyroid crisis.

Adult↗
PubMed1989

[The role of Na+-K+ ATPase activity on blood pressure regulation and sodium metabolism in DOCA-treated rats].

In this study, we attempt to clarify the role of sodium-potassium adenosine 5'-triphosphatase (N+-K+ ATPase) on the regulation of systemic blood pressure and renal sodium metabolism. Male Wistar rats (n=20) were divided into four groups: 1) controls (n=5), 2) sodium loading rats (NaCl group, n=5), 3) deoxycorticosterone (DOCA group, n=5) injected rats with intact kidneys (DOCA group, n=5), 4) DOCA and ouabain-injected rats with intact kidneys (ouabain groups) and raised for six weeks. The changes in urine volume and urinary sodium were determined, and urinary excretions of norepinephrine (NE), epinephrine (E) and dopamine were measured in week six. Then blood samples were obtained from the inferior vena cava, and plasma cyclic AMP (cAMP) and cyclic GMP (cGMP) concentration were measured. At the time of sacrifice, systolic blood pressure of the ouabain group (157.3 +/- 24.8 mmHg) was significantly higher than the control group (124.5 +/- 6.9 mmHg) (p less than 0.05), but no significant differences were observed between the control group, NaCl group (123.7 +/- 7.0 mmHg), and DOCA group (128.1 +/- 4.5 mmHg). Urine volume and sodium excretion in the NaCl, DOCA and ouabain groups all increased, but the natriuretic response in the NaCl group was smaller than in either the DOCA and ouabain groups. Urinary NE in the NaCl, DOCA and ouabain groups was 1396 +/- 1025 ng/day, 640 +/- 351 ng/day, 607 +/- 177 ng/day, respectively, and NE excretions in these groups were higher than in the control group (138 +/- 104 ng/day). Urinary E in the NaCl group was higher than in the control group, but there were no significant differences among the control, DOCA and ouabain groups. Urinary dopamine in the NaCl (5723 +/- 2028 ng/day), DOCA (7661 +/- 5992 ng/day) and ouabain (4077 +/- 1984 ng/day) groups was higher than in the control group (2081 +/- 483 ng/day). Plasma cAMP in the DOCA and ouabain groups was slightly higher than in the control group, while no significant differences in plasma cAMP between the control and NaCl groups were observed. Plasma cGMP in the DOCA group was slightly higher than in either of the other three groups. These results suggest that Na+-K+ ATPase may play an important role in the maintenance of blood pressure through sodium efflux and that ouabain, Na+-K+ ATPase inhibitor, may change the renal sodium excretion and vascular responsiveness to endogenous pressor substances, leading to higher blood pressure after the administration of sodium and mineralocorticoid.

Animals↗
PubMed1989

Delayed neurotoxicity of triphenyl phosphite in hens: pharmacokinetic and biochemical studies.

The organophosphorus compound, triphenyl phosphite (TPP), caused ataxia in chickens 8-14 days after single po or iv administration. The po and iv ED50 values were 1414 and 35.4 mg/kg, respectively. Chickens which developed ataxia lost 14.4 +/- 2.5% (mean +/- SEM, n = 14) of their initial weight at 28 days and the paralyzed birds showed a severe reduction of 29.3 +/- 2.9% (n = 13) of their initial weight at death or at 28 days after dosing. For the first 4-hr interval after iv injection of 50 mg/kg, the elimination of TPP from plasma consisted of at least two exponential phases; the half-lives of the first and second phases were approximately 30 and 60 min, respectively. When the birds received 100 mg/kg (iv) fatty tissue showed the highest TPP concentration, e.g., 215 micrograms/g fresh wt at 6 hr postdosing. The half-life was approximately 24 hr. Among neural tissues, the sciatic nerve had the highest concentration, followed by the spinal cord, the cerebellum, and the cerebrum. The red muscles, such as adductor magnus, contained about 4-30 times as much TPP as did the white muscles, such as biceps brachii, 6 hr after treatment. Time course effects of TPP treatment on mitochondrial enzymes in leg skeletal muscles were examined by treating hens with 50 mg/kg (iv) and euthanizing the birds at 6 hr to 8 days postdosing. The creatine kinase (CK) activities of the adductor and the soleus were significantly decreased at 2 (48 hr), 4, and 8 days, and at 4 and 8 days postdosing, respectively. Adductor magnus and soleus succinate dehydrogenase (SDH) activities were decreased markedly at 24 and 48 hr, and at 2 (48 hr), 4, and 8 days, respectively. Cytochrome oxidase (COD) activity in adductor magnus and soleus did not decrease during the time course. Biceps femoris CK, SDH, and COD activities were not affected by TPP treatment at this dosage. These results suggest that TPP administration affects the mitochondrial metabolism in skeletal muscle, especially red muscle of chickens.

Animals↗