Search PubMed⌕ Search

Biomedical subjects

K Sugimoto

Publications and source records attributed to K Sugimoto.

At least 541 records · Page 30Linked to original sources
PubMed1988

Role of actin filaments in shape formation of mesenteric mesothelial cells of the bullfrog.

The role of actin filaments in the development of cellular shape in the mesenteric mesothelium of the bullfrog was studied by using a simple, new technique for making en face preparations of mesothelial sheets. By using these mesothelial cell preparations, the distribution of actin was determined by means of fluorescence microscopy with 7-nitrobenz-2-oxa-1,3-diazole (NBD)-phallacidin and that of myosin by means of immunofluorescence microscopy. Although fluorescence produced by both NBD-phallacidin and antimyosin staining was found exclusively along the margins of the cells, its intensity was altered in correspondence with changes in cell shape. For instance, tadpole-type mesothelial cells with either an irregular or very slender cell shape showed very weak fluorescence. On the other hand, frog-type mesothelial cells with a polygonal shape showed intense fluorescence at their margins and had circumferential bundles of actin filaments at their apices. Furthermore, intercellular junctions between the mesothelial cells developed as the cell shape became polygonal during metamorphosis. The present study showed that development of circumferential bundles of actin filaments and intercellular junctions may serve to establish and maintain the definitive polygonal cellular pattern in the mesenteric mesothelium of the bullfrog.

Actins↗
PubMed1988

Comparison between the fluorometric HPLC method and the conventional method for determining urinary delta-aminolevulinic acid and coproporphyrin as indices of lead exposure.

Fluorometric methods for determining delta-aminolevulinic acid (ALA) and coproporphyrin (CP) in urine have been recently developed by using high-performance liquid chromatography (HPLC). In the present study, urinary ALA and CP in lead-exposed workers were determined with these fluorometric HPLC methods and the conventional methods, and the results obtained were compared. In lead workers with a urinary ALA greater than or equal to 5 mg/l, the values obtained with the fluorometric HPLC method corresponded well with those measured with the conventional colorimetric method. In contrast, in lead workers with ALA less than 5 mg/l, ALA values obtained with the fluorometric HPLC method were lower than those measured with the conventional method, suggesting the possibility of matrix interference in urine. The urinary CP values obtained with the conventional method of Rimington (1971) were higher than those measured with the fluorometric HPLC method, though the correlation was good.

Adult↗
PubMed1988

Relationship between inhibition of erythrocyte pyrimidine 5'-nucleotidase activity and biological response for porphyrin metabolism in workers occupationally exposed to lead.

A rapid determination of erythrocyte pyrimidine 5'-nucleotidase (P5N) activity in lead workers was carried out using a high-performance liquid chromatograph (HPLC). The P5N activity had a good negative correlation with the concentration of lead in blood (PbB) ranging from 16 to 96 micrograms/dl (r = -0.82, n = 77). Further, the P5N was compared with other biological parameters: erythrocyte delta-aminolevulinic acid dehydratase (ALAD) activity, erythrocyte protoporphyrin (PROTO), urinary delta-aminolevulinic acid (ALA) and urinary coproporphyrin (COPRO). The correlation coefficients between P5N and ALAD, log PROTO, log ALA, and log COPRO were 0.59, -0.72, -0.65, and -0.61, respectively. On the other hand, the normal value of P5N obtained from 72 healthy subjects was 11.9 +/- 2.1 units; mumol uridine/h/g Hb (mean +/- SD), indicating that the lower limit of 95% confidence interval for normal P5N was about 8 units. When P5N was cut off at less than or equal to 8 units in 77 lead workers, the validity (sensitivity + specificity) for PbB greater than or equal to 40 micrograms/dl, PbB greater than or equal to 60 micrograms/dl, erythrocyte PROTO greater than or equal to 150 micrograms/dl RBC, urinary ALA greater than or equal to 6 mg/l, and urinary COPRO greater than or equal to 150 micrograms/l was 1.66, 1.76, 1.57, 1.68, and 1.60, respectively. From these results, it was confirmed that the erythrocyte P5N test is suitable for the biological monitoring of exposure to lead in a wide range, and its activity is useful in predicting the disturbance of porphyrin metabolism induced by lead.

5'-Nucleotidase↗
PubMed1988

Change in priming sites for discontinuous DNA synthesis between the monomeric and concatemeric stages of phage T7 replication.

We have analyzed the transition sites between primer RNA and DNA in a 589 bp segment of the bacteriophage T7 genome. In the monomeric replication stage, RNA-DNA transition sites are predominantly on the light (L) strand (with 5'----3' polarity on the genetic map) but rarely on the heavy (H) strand, indicating that replication proceeds semidiscontinuously with the H and L strands corresponding to the leading and lagging strands, respectively. The direction of replication is that expected from the position of the primary origin and also indicates that secondary origins are seldom if ever used. In the concatemeric stage of replication, RNA-DNA transition sites are instead distributed on both strands of the segment with equally high frequency, showing that initiation occurs within the concatemeric molecule per se and by a different mechanism.

Base Sequence↗
PubMed1988

Improved sodium hydroxide digestion method without homogenization for extraction of gentamicin from renal tissue.

Recovery of gentamicin from renal cortical tissue (assayed by fluorescence polarization immunoassay) was highest (P less than 0.05) when using a sodium hydroxide (NaOH) digestion procedure without homogenization (90.0 +/- 5.4%), followed by homogenization with NaOH digestion (85.8 +/- 7.7%) and homogenization with trichloroacetic acid precipitation (84.4 +/- 3.3%). Simple homogenization recovered the least gentamicin (59.0 +/- 5.2%; P less than 0.05).

Animals↗
PubMed1988

[Effects of flutropium bromide, a new antiasthma drug, on mediator release from mast cells and actions of mediators].

The effects of flutropium bromide (Ba598Br), a new antiasthma drug possessing the quarternary ammonium structure of atropine derivatives, on mediator release from mast cells and on actions of leukotriene (LT) D4 and serotonin were investigated. Flutropium bromide (3 and 10 mg/kg, i.v.) showed an inhibitory action on the 48 hr homologous PCA in guinea pigs. Atropine showed no inhibitory effect. Flutropium bromide also inhibited the release of histamine from isolated rat mast cells stimulated by antigen, although the inhibitory action was weaker than that of disodium cromoglycate. Atropine also had no inhibitory action in this case. Flutropium bromide and atropine showed no antagonistic action against LTD4-induced contraction of isolated tracheal smooth muscle of guinea pigs. Inhalation of flutropium bromide (0.3%) also showed no antagonistic action against serotonin-induced bronchoconstriction in dogs. From the above results, it is indicated that flutropium bromide has a weak mast cell stabilizing action, but no antagonistic action against LTD4 and serotonin.

Animals↗
PubMed1988

[Assessment of occupational exposures to industrial hazardous substances. I. A proposed method based on interday fluctuation of contaminant concentrations for evaluating employee's exposure averages (TWAs)].

Occupational exposures to potentially hazardous substances may vary considerably because of factors such as sampling and analytical errors, and intraday and interday environmental fluctuations in contaminant concentration. Of these factors, day-to-day environmental fluctuations most likely affect daily exposure averages over days, weeks, months or years. A new method based on day-to-day fluctuations of daily exposure averages (geometric standard deviation) was developed for making reliable assessment of the employee's exposure situation. It is assumed that daily exposure averages of a worker are lognormally and independently distributed statistically. Finally, a classification scheme on the basis of n days measurements is presented. 95% upper limit or arithmetic mean of individual exposure averages (8-h TWAs) can be evaluated in comparison with an established standard. The method may provide an approximate estimate because of statistical premise, but it can be utilized for practical purposes, particularly, in case where only one or two days are being monitored. An action level concept based on random sampling and analytical errors and interday variations developed by OSHA/NIOSH, and a sampling and decision scheme based on one-sided tolerance limits proposed by Tuggle (1982) are also discussed.

Data Interpretation, Statistical↗
PubMed1988

[Assessment of occupational exposures to industrial hazardous substances. II. Interday fluctuations of the daily exposure averages among workers exposed to lead].

An assessment of the employee's exposures to industrial hazardous substances using the proposed method described earlier was conducted on 49 workers exposed to lead. As it is assumed that the daily exposure averages are lognormally distributed, geometric standard deviation (sigma g) representing true interday fluctuations of the daily exposures was estimated by personal exposure measurements of every worker for two consecutive days. The estimates (Sg) ranged from 1.00 to 5.35 with a median of 1.4 and a 90% upper limit of 2.4. According to a classification scheme in the proposed method, exposure levels (I to III) were calculated using sigma g of 1.4 and 2.4. An exposure class based on a single day measurement was evaluated and compared to that based on measurements for two consecutive days. As a result, the decision of the exposure levels and classes from only one day monitoring could be made by using both sigma g of 1.4 and 2.4, representing ordinary and high interday fluctuations, respectively. More accurate estimate of geometric standard deviation of interday fluctuations by exposure monitorings would provide a more reliable assessment of the worker's long-term exposure situation.

Data Interpretation, Statistical↗
PubMed1988

[The method for stress assessment of workers (Part 1). Stress score by self-rating method].

In order to evaluate the grade of reaction to stressors, especially those on occupational life of workers, the following stress survey was conducted. Eighteen new items of occupational life stressors were proposed in addition to the social readjustment rating scale (S.R.R.S.) prepared by Holmes. Furthermore, two items, "own stress tolerance" and "own stress at present," were designed in addition to the foregoing 65 stressors. Marriage is given a score of 50 in reference-standard of stress strength. These 67 items of 1,630 workers were evaluated by the self-rating method ranging in score from 0 to 100. The results can be summarized as follows: 1. As for each item, we examined the average value of the total sample and analyzed them by sex, age, kind of occupation, position, and length of service. We named these stress scores and analyzed the ranking of 65 stress scores. The item with the highest score was "death of spouse (score 82.7)" and the item with the lowest one was "income increase (score 24.7)." The scores of 27 out of 65 items were higher than 50. Next, 65 items were classified into 4 groups, that is, individual life, family life, occupational life, and social life. 2. Scores of the newly designed items to examine the ability to adjust oneself to place of work were "own stress tolerance (score: 73.7)" and "own stress at present (48.8)," respectively. 3. We examined the difference by sex, age, kind of occupation, position, and length of service based on the average value of stress score by t-test and the following results were obtained. 1) Scores of those in the thirties were higher than those in the twenties. 2) Section heads and leaders were under greater stress than division heads. In the same way, the differences among the four groups were analyzed and the following results were observed. 1) The only significant difference was seen in the occupational life stress group. 2) In the occupational life stress group, the scores of those in the thirties, forties, and fifties were higher than those in the twenties. Section heads and leaders were under greater stress than the staff. Workers in service for more than 21 years had higher scores than workers in service for less than 10 years. 4. The practical uses of our stress survey are also discussed in this report.

Adult↗
PubMed1988

[Long-term survival in malignant atrophic papulosis: a case report and review of the Japanese literature].

Malignant atrophic papulosis (MAP) is characterized by skin lesion and high mortality rate caused by perforation of the GI tract or involvement of the central nervous system. Approximately 100 cases have been reported in the world literatures, but etiology is unknown. A 44-year-old female patient was admitted for chest and abdominal pain with characteristic papuloses, which had been noted by the patient seven years ago. Because of positive peritoneal irritation and intraabdominal free air, exploratory laparotomy was done. Multiple red inflammatory or yellow atrophic maculae on the entire intestine with no obvious perforation but with air-leak were found. Those perforations were closed with seromuscular sutures. The patient is doing well sixteen months after surgery. Fourteen MAP cases have been reported in the Japanese literature. As is found in the world literature, the mortality rate is extremely high. All of reported cases were initially diagnosed because of the particular skin lesions. Abdominal symptoms developed in 10 cases and six of these died. Three cases died within three weeks after bowel resection. There are three surviving cases. One was treated conservatively even though intraabdominal free air was present. Two had three operations, including one simple closure and two intraabdominal explorations. According to this result, a bowel resection should not be performed on MAP patients because of this high mortality. Administration of anticoagulants, i.e., heparin, prostaglandin E1 and ticlopidine seems to be effective in alleviating symptoms and might prevent further deterioration.

Adult↗