PubMed Health⌕ Search

Biomedical subjects

Y Tasaki

Publications and source records attributed to Y Tasaki.

At least 37 records · Page 2Linked to original sources
PubMed1995

The rat saphenous flap: a fasciocutaneous free flap model without panniculus carnosus.

The rat saphenous flap is described as a new experimental model for free flap studies. This is a fasciocutaneous free flap based on the saphenofemoral vascular pedicle. The flap may include the entire medial aspect of the lower leg between the knee and ankle. Thirty flaps were harvested from 15 inbred rats. Each flap was transferred to the anterior neck of a recipient rat of the same inbred strain so that 15 flaps were vascularized free flaps using the standard end-to-end microvascular technique and the other 15 flaps were nonvascularized free grafts. All but two (technical failure) of the vascularized flaps showed complete survival, whereas all nonvascularized flaps completely necrosed 2 weeks after transfer. It was concluded that the rat saphenous flap has several advantages such as a long and consistent vascular pedicle, ease of harvest, and an all-or-none survival pattern. Furthermore, as a unique feature of this flap, histological analysis revealed that the rat saphenous flap is composed of the skin and underlying fascia without panniculus carnosus. We therefore suggest that the rat saphenous flap is the first true fasciocutaneous free flap model in the rat. In this paper, in addition to illustrating the anatomy of the saphenous vessels and describing a new fasciocutaneous free flap model based on these vessels, we have documented some anatomical details of the rat leg that have never been described in the literature related to the rat anatomy.

Animals↗
PubMed1995

A true osteomyocutaneous free-flap model in rats: the saphenous artery osteomyocutaneous flap.

A new composite free-flap model, namely, the saphenous artery osteomyocutaneous flap, is described in the rat. This is a true osteomyocutaneous flap composed of a skin island from the medial aspect of the lower leg, the gracilis and semitendinosus muscles, and a bone segment from the tibia based on the saphenous vascular pedicle. After anatomic studies in 10 rats, 20 flaps were transplanted microsurgically to the abdominal region in the recipient rats with a 90 percent success rate. In selected animals, arteriography was carried out. The results from gross observation of the flap survival and histologic and fluorochrome bone-labeling studies revealed a complete survival for each component of the flap in all animals with a patent vascular pedicle at 2 weeks after transfer. The model seems to be suitable for use in metabolic, vascular, and immunologic experimental studies on composite free flaps.

Animals↗
PubMed1995

Reversal by a dihydropyridine derivative of non-P-glycoprotein-mediated multidrug resistance in etoposide-resistant human prostatic cancer cell line.

PURPOSE: We have isolated etoposide-resistant prostatic cancer cell lines, P/VP10 and P/VP20, to investigate the multidrug resistance (MDR) mechanism and to find MDR reversal agents. MATERIALS AND METHODS: We examined expression of MDR-related genes and screened reversal agents of MDR in P/VP20 cells. RESULTS: These cells demonstrated a non-P-glycoprotein (P-gp)-mediated MDR phenotype with overexpression of MDR-associated protein (MRP) mRNA due to MRP DNA amplification. A 1,4-dihydropyridine derivative, bis(4-pyridylmethyl)4-[2-(3-methyl-5,6- dihydro-1,4-dithiinyl)]-2,6-dimethyl-1,4-dihydropyridine-3,5-dicar boxylate (NIK250), was found to overcome MDR in P/VP20 cells. CONCLUSIONS: NIK250 might be useful in reversing MDR, which often develops during chemotherapy of advanced or hormone-resistant prostatic cancer.

Cell Line↗
PubMed1994

Muscle glycogen repletion and pre-exercise glycogen content: effect of carbohydrate loading in rats previously fed a high fat diet.

We have recently reported that rates of muscle glycogen repletion during the early period of recovery were increased by carbohydrate (CHO) loading in rats previously fed a high fat diet. However, the reason for this remained unanswered. The purpose of this study was to examine whether an increase of glycogen utilization due to an elevated pre-exercise glycogen store would enhance rates of glycogen repletion in muscle. Despite an equal degree of glycogen depletion, the rates of glycogen repletion of soleus, red and white gastrocnemius muscles by postexercise administration of glucose (3.0 g.kg-1 body mass) and citrate (0.5 g.kg-1 body mass) were faster in the CHO loaded (3 days) rats than in the nonloaded rats, as a result of elevated pre-exercise glycogen content and consequently the greater glycogen utilization. The higher rate of muscle glycogen repletion may in part be explained by increased postexercise glycogen synthase activity.

Animal Feed↗
PubMed1994

Is bed isolation necessary during flap prefabrication? An experimental study in rats.

This study was designed to investigate whether isolation of the bed is necessary during flap prefabrication. A fasciovascular carrier was used to prefabricate a 3 x 8-cm epigastric flap in rats. The animals were divided into three groups of 42 each. During flap prefabrication, in group 1 (control), no bed isolation was done, whereas in groups 2 and 3, a thin silicone sheet was used to isolate the underlying bed from the flap and fasciovascular carrier partially or completely, respectively. In each group, 14 prefabricated flaps were raised at 3, 7, and 14 days after prefabrication. Flap survival was assessed at day 7 after flap elevation. In comparing to the survival rates of the prefabricated flaps for each time interval, there was no significant statistical difference between the control and experimental groups (p > 0.05). With further studies, including india ink injection study and microangiographical and histological examinations of the prefabricated flaps, it was concluded that, during flap prefabrication, isolation of the bed with a silicone sheet does not improve the survival of prefabricated skin flaps. Moreover, it may cause some complications, such as extensive seroma, infection, and exposure of the sheet, which further interfere with the evaluation of experimental results.

Angiography↗
PubMed1992

Effect of short-term exercise training on muscle glycogen in resting conditions in rats fed a high fat diet.

It has been reported that exercise training increases muscle glycogen storage in rats fed a high carbohydrate (CHO) diet in resting conditions. The purpose of this study was to examine whether a 3-week swimming training programme would increase muscle glycogen stores in rats fed a high-fat (FAT) diet in resting conditions. Rats were fed either the FAT or CHO diet for 7 days ad libitum, and then were fed regularly twice a day (between 0800 and 0830 hours and 1800 and 1830 hours) for 32 days. During this period of regular feeding, half of the rats in both dietary groups had swimming training for 3 weeks and the other half were sedentary. The rats were not exercised for 48 h before sacrifice. All rats were killed 2 h after their final meal (2030 hours). The glycogen contents in red gastrocnemius muscle, heart and liver were significantly higher in sedentary rats fed the CHO diet than in those fed the FAT diet. Exercise training clearly increased glycogen content in soleus, red gastrocnemius and heart muscle in rats fed the CHO diet. In rats fed the FAT diet, however, training did not increase glycogen content in these muscles or the heart. Exercise training resulted in an 87% increase of total glycogen synthase activity in the gastrocnemius muscle of rats fed the CHO diet. However, this was not observed in rats fed the FAT diet. The total glycogen phosphorylase activity in the gastrocnemius muscle of the rats of both dietary groups was increased approximately twofold by training.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

A new experimental model: the vascular pedicle cutaneous flap over the dorsal aspect (flank and hip) of the rat.

Cutaneous vascular anatomy of the flank and the hip was studied in the rat. Investigation was done by anatomical dissection, ink injection to the axial artery and flap harvesting in living rats. Anatomical dissection and India ink injection revealed that the rat's flank and hip skin derives its blood supply from the iliac branch of the iliolumbar artery, which originates from the lateral aspect of the abdominal aorta. The vascular territory of the iliac branch of the iliolumbar artery was defined as follows: the medial border--along the midline of the back from the 12th rib to the proximal part of the tail; the lateral border-anterior axillary line corresponding with the length of the medial border; the cephalic border--a line joining the medial and lateral border at the level of the 12th rib; and the caudal border--the posterior lateral line of the hip. On the basis of the vascular territory demarcated by India ink injection, bilateral vascular pedicle island cutaneous flaps were harvested in living rats. Results showed total survival of all flaps. This flap is easily made, and it could be used as a reliable model for flap research.

Animals↗
PubMed1992

Cutaneous vascular anatomy of the thoracic region of the dorsum and its role in flap design in the rat.

The cutaneous vascular anatomy of the proximal one-half of the dorsum (the thoracic region) and its role in flap design was studied in the rat. The investigation included anatomical dissection, ink injection into the axial artery, and flap harvesting in live animals. Anatomical dissection and india ink injection of the thoracic region revealed that the skin derives its principal blood supply from the lateral thoracic artery. The cutaneous vascular territory of the lateral thoracic artery was defined as follows: the medial border, along the midline of the back from the level of the inferior angle of the scapula to the lower border of the last rib; the lateral border, anterior axillary line corresponding with the length of the medial border; the cephalic border, a line joining the medial and lateral border at the level of the inferior angle of the scapula; and the caudal border, a line corresponding to the lower border of the last rib. Bilateral vascular pedicle island cutaneous flaps were harvested in living rats based on the vascular territory demarcated by India ink injection. All flaps survived; hence, this flap is reliable, with consistent vascularity, and is easy to harvest, and therefore, can be used as a vascular pedicle experimental model to study flap hemodynamics.

Animals↗
PubMed1991

Prostaglandin D2 metabolite stimulates collagen synthesis by human osteoblasts during calcification.

We investigated the effect of the prostaglandin D2 metabolite delta 12-PGJ2 (9-Deoxy-delta 9, delta 12-13,14-dihydroprostaglandin 2D) on collagen synthesis in human osteoblasts. delta 12-PGJ2 at 10(-5) M enhanced collagen synthesis in the presence of 2 mM alpha-glycerophosphate-2Na. The stimulative effect appeared as early as 3 days after addition and continued until 22 days. The enhancement of type I collagen synthesis was confirmed by polyacrylamide gel electrophoresis. The potency was the same as 10(-8) M 1 alpha, 25 dihydroxy vitamin D3 (1,25(OH)2D3). Northern blot analysis showed that 10(-5) M delta 12-PGJ2 and 10(-8) M 1,25(OH)2D3 enhanced the transcription of type I procollagen (alpha 1) mRNA levels in osteoblasts.

Blotting, Northern↗
PubMed1991

Isozyme polymorphisms in human diploid cell strains for research on cellular aging.

Six human lung diploid cell strains established for the study of in vitro cellular aging (TIG-1, TIG-7, WI-38, IMR-90, MRC-5, MRC-9, and HeLa cells as a control) were studied by cellulose acetate membrane electrophoresis for allozymic differences at 18 enzyme loci. Eight enzyme loci (G6PD, PGM1, PGM3, PepA, PGD, ADA, GLO1, and ME), proved to be informative in establishing unique allozyme genetic signatures for all of the cell strains established from the same species and from the same organ. Changes in the allozyme genetic signatures were not observed throughout the life span of TIG-1 and MRC-9 cells. The allozyme genetic signatures can be used as a quick monitor of cell identification and intraspecific cell contamination.

Cell Line↗
PubMed1991

A new human male diploid cell strain, TIG-7: its age-related changes and comparison with a matched female TIG-1 cell strain.

A new human diploid cell strain, TIG-7, which has the male karyotype, was established and characterized. Isozyme and histocompatibility typing of the cell strain was performed. The average in vitro life span of the cells is 73 population doublings. Changes in cell volume, doubling time, saturation density, the efficiency of cell attachment, plating efficiency, and relative DNA content were examined during in vitro cellular aging. Hydrocortisone slightly prolongs the life span of the cell strain when the hormone is administered to the cultures during middle passages. The age-related changes in the parameters of TIG-7 are not appreciably different from those of the previously established TIG-1 cell strain. These results show that this cell strain is useful for research on cellular aging; further profit is anticipated from research using a combination of these two sexually different cell strains.

Cell Line↗
PubMed1991

Nutritional status and daily physical activity of handicapped students in Tokyo metropolitan schools for deaf, blind, mentally retarded, and physically handicapped individuals.

Heights, weights, and skinfold thicknesses of 2222 handicapped students aged 3-22 y were measured in the 1984 nutritional survey for handicapped students in Tokyo metropolitan schools for deaf, blind, mentally retarded, and physically handicapped individuals. Although delayed growth was most obvious in physically handicapped students, obesity was already prevalent in many different types of handicapped students, especially those who were mentally handicapped. To estimate daily physical activity, 473 males and 329 females wore a pedometer for 24 h. There were considerable differences in the mean pedometer scores among the four groups of students: deaf greater than blind = mentally retarded greater than physically handicapped. In the female students who could walk normally, pedometer scores were negatively related with both body mass index and percent body fat. The nutritional status in the handicapped students is discussed in relation to daily physical activity.

Activity Cycles↗
PubMed1991

1-Methyl-1,2,3,4-tetrahydroisoquinoline, decreasing in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated mouse, prevents parkinsonism-like behavior abnormalities.

In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mouse brain, there was no significant increase or decrease in the content of an endogenous amine, 1,2,3,4-tetrahydroisoquinoline (TIQ), which is well noted for inducing parkinsonism, whereas another endogenous amine, 1-methyl-1,2,3,4-tetrahydroisoquinoline (1-MeTIQ), was markedly reduced. This result agrees with the finding in human idiopathic parkinsonianism, confirmed by our previous research. In addition, pretreatment with 1-MeTIQ completely prevented MPTP- or TIQ-inducing bradykinesia, a symptom of parkinsonism. This study confirmed that 1-MeTIQ plays an important role in preventing the pathogenesis of parkinsonism and is a possible leading compound of anti-parkinsonism agents.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1991

[Multi-center evaluation of Showa disk susceptibility to presumptively determine minimum inhibitory concentrations through linear regression analysis].

To confirm the reliability of minimum inhibitory concentrations (MICs) determined by use of predefined linear regressions to bacterial growth inhibitory zone diameter on Showa disk susceptibility test, the multi-center evaluation along daily routines was performed in comparison with the standard agar dilution method. In total, 4,107 (89.0%) of 4,613 testings gave comparable MICs with 4-fold or less differences to those determined by the standard agar dilutions. The agreement of MICs (less than or equal to 4-fold differences) for gram-negative rods, excluding Pseudomonas aeruginosa, against 10 antimicrobial agents was estimated to 92.1%, and those for gram-positive cocci against 9 agents and for the strains of Pseudomonas aeruginosa against 8 agents were 84.5% and 81.7%, respectively. With these results, we can conclude that, under the well-controlled test procedures, the MIC correlates determined by Showa disk susceptibility test are enough comparable to those determined by the standard agar dilution method.

Anti-Bacterial Agents↗
PubMed1990

Confirmation of the enantiomers of 1-methyl-1,2,3,4-tetrahydroisoquinoline in the mouse brain and foods applying gas chromatography/mass spectrometry with negative ion chemical ionization.

With the aid of a new chiral derivatizing reagent and a sensitive and specific assay using capillary gas chromatography/negative ion chemical ionization mass spectrometry, the proportions of R and S enantiomers of 1-methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ) in mammalian tissues and foods were studied. R- and S-1MeTIQ enantiomers derivatized with a chiral derivatizing reagent, perfluoro-2-propoxypropionylchloride, were clearly separated. The ratio of enantiomers was R/S = 0.24, 0.55 and 0.60 in wine, cocoa and mouse brain. S-1MeTIQ predominated in all samples. This result suggested that 1MeTIQ could be formed at least partially through an enzymatic mechanism.

Animals↗
PubMed1990

Metabolism and brain accumulation of tetrahydroisoquinoline (TIQ) a possible parkinsonism inducing substance, in an animal model of a poor debrisoquine metabolizer.

4-Hydroxytetrahydroisoquinoline (4OH-TIQ) was detected as a metabolite of a possible parkinsonism-inducing substance, tetrahydroisoquinoline (TIQ), in rat liver microsomes and rat urine. Urinary excretion of 4OH-TIQ was significantly reduced in female DA rat, an animal model of a poor debrisoquine metabolizer. The female DA rat also showed significantly higher brain accumulation of TIQ. These results suggest that the metabolic detoxication process is depressed and TIQ accumulation in the brain is enhanced in a poor debrisoquine metabolizer, which may be one possible explanation for poor debrisoquine metabolizers being susceptible to Parkinson's disease.

Animals↗
PubMed1990

A novel and neurotoxic tetrahydroisoquinoline derivative in vivo: formation of 1,3-dimethyl-1,2,3,4-tetrahydroisoquinoline, a condensation product of amphetamines, in brains of rats under chronic ethanol treatment.

Repeated amphetamine administration to rats under chronic ethanol intoxication resulted in the formation of 1,3-dimethyl-1,2,3,4-tetrahydroisoquinoline (1,3-DiMeTIQ), a novel metabolite of amphetamines. 1,3-DiMeTIQ was quantified with a sensitive, specific assay using gas chromatography-mass spectrometry. It was not found in the brains of rats given repeated amphetamine administration but no ethanol. The chronic ethanol-intoxicated rats subjected to repeated amphetamine administration exhibited behavioral abnormalities, such as repeated convulsions and curving of the back. 1,3-DiMeTIQ contents were markedly higher in the brain or plasma of rats manifesting abnormal behavior in comparison with those in rats behaving normally. Thus, the 1,3-DiMeTIQ content in the rat brain seems to have some relationship with behavioral abnormalities. This study also confirmed that 1,3-DiMeTIQ can cross the blood-brain barrier in the rat. Intraperitoneal 1,3-DiMeTIQ injections to rats caused behavioral symptoms similar to those observed in rats with chronic ethanol intoxication and repeated amphetamine administration. The effect of toxic doses of 1,3-DiMeTIQ on dopaminergic and serotonergic metabolism in the whole rat brain was also investigated.

Alcoholism↗