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Biomedical subjects

Y Ikuta

Publications and source records attributed to Y Ikuta.

At least 109 records · Page 6Linked to original sources
PubMed1996

Permeation from the synovial fluid as nutritional pathway for the anterior cruciate ligament in rabbits.

The anterior cruciate ligament of the knee receives its nutrition from a direct vascular supply and by permeation of nutrients from synovial fluid. In order to quantitate the relative importance of these two routes and to compare the anterior cruciate ligament with the medial collateral ligament, we injected [3H]methyl-glucose as a tracer intravenously or directly into the knee in rabbits. Tracer concentrations in plasma, synovial fluid, the anterior cruciate ligament and the medial collateral ligament were analysed by a pharmacokinetic compartment model developed for this study. The contribution of [3H]methyl-glucose permeation from the synovial fluid was calculated at 59.7% in the anterior cruciate ligament and at 18.1% in the medial collateral ligament. We concluded from these results that the nutrition for the medial collateral ligament, which is an extraarticular structure, is provided mainly by its vascular supply. In contrast, synovial fluid permeation is an important transport route for small molecules for the normal anterior cruciate ligament.

Animals↗
PubMed1996

Penile replantation after self-inflicted complete amputation: case report.

A case of penile replantation is reported in which a 37-year-old man suffered a self-inflicted complete penile amputation. Replantation was successfully performed; at 3 months after surgery, a urethrocystogram demonstrated the absence of urethral stricture. Although complete erection has yet to be obtained, no other functional impairments have been encountered at 7 months after replantation. Reconstruction of the venous system is considered to be one of the most important factors in achieving a successful penile replantation.

Adult↗
PubMed1996

Delay of the denervation process in skeletal muscle by sensory ganglion graft and its clinical application.

We examined the effects of dorsal root ganglion isografts on the denervation process of skeletal muscle. A segment of sciatic nerve was removed from each of 25 inbred Wistar-Kyoto rats. Fifteen were set aside as controls. In the remaining 10 rats, isogeneic cervical dorsal root ganglia were grafted to the severed distal stump of the common peroneal nerve. Between day 72 and day 286 postoperatively, both controls and recipients were killed after twitch and tetanic tension recording of the extensor digitorum longus was performed. The wet muscle weight and the twitch and tetanic tensions of the denervated extensor digitorum longus in the graft group were significantly greater than those in the control group. The mean area of the denervated tibialis anterior muscle fibers in the graft group also was significantly larger than that in the control group. In electron and light microscopic images, nerve cells along the periphery of each dorsal root ganglion were found surviving with regenerating axons throughout the experimental period. Numerous myelinated axons were observed in the common peroneal nerve of the graft group, and there were significantly more axonal branches in the extensor digitorum longus of the graft group than in the extensor digitorum longus of the control group. Thus sensory nerve fibers from the grafted dorsal root ganglia had certain beneficial effects to slow the denervation process, presumably secreting trophic factors into the denervated muscle. Clinically, we have transferred avulsed dorsal root ganglia in cases of total brachial plexus avulsion directly into denervated skeletal muscle. This procedure, accompanied by nerve crossing procedures, will probably keep denervated skeletal muscle in a better condition until regenerating motor axons from the repair site reach their target muscle.

Animals↗
PubMed1996

Serum markers for fibrosis and plasma transforming growth factor-beta 1 in patients with hepatocellular carcinoma in comparison with patients with liver cirrhosis.

In order to elucidate collagen metabolism in hepatocellular carcinoma (HCC) tissue, we compared levels of different potential markers of collagen metabolism and plasma transforming growth factor-beta 1 in patients with HCC and in patients with liver cirrhosis. Serum levels of prolyl hydroxylase and the tissue inhibitor of metalloproteinase-1 in patients with HCC were significantly higher than those in patients with liver cirrhosis and increased with the size of the HCC tumour, whereas the serum levels of procollagen type III propeptide and type IV collagen 7S domain were similar in the two groups. In HCC, the increased plasma transforming growth factor-beta 1 levels were closely correlated with serum levels of prolyl hydroxylase and the tissue inhibitor of metalloproteinase-1. These findings suggest that, in HCC tissue, the intracellular biosynthesis of collagen is enhanced, whereas the secretion of procollagen is disturbed and the degradation of collagen is suppressed by the excess production of the tissue inhibitor of metalloproteinase-1. The results also suggest that plasma transforming growth factor-beta 1 plays an important role in the altered metabolism of collagen in HCC.

Aged↗
PubMed1996

Clinical significance of serum hyaluronan in patients with chronic viral liver disease.

In order to elucidate the clinical significance of serum hyaluronan in chronic viral hepatitis, serum hyaluronan concentrations were measured using a sandwich enzyme binding assay in 115 patients with chronic viral hepatitis. These findings were examined in relation to the results of laboratory liver tests, levels of serum markers for fibrosis and liver histological findings. Serum hyaluronan levels increased with the progress of liver disease, particularly in liver cirrhosis. There were no significant differences in serum hyaluronan levels among the cirrhotic patients according to Child's grade. Multivariate analysis showed that the significant independent predictors of serum hyaluronan were serum aspartate aminotransferase (P = 0.020), serum alanine aminotransferase (P = 0.008), serum cholinesterase (P < 0.001), particularly serum type IV collagen 7S domain (P < 0.0001), and the histological degree of liver fibrosis (P < 0.0001). These findings suggest that elevated serum hyaluronan levels are closely related to the severity of liver fibrosis. We assessed the predictive value of serum hyaluronan in differentiating cirrhosis from chronic hepatitis, constructing receiver operating curves; we found that serum hyaluronan was a better test for diagnosing cirrhosis than serum type IV collagen 7S domain and laboratory liver tests.

Adult↗
PubMed1996

Transdermal iontophoretic delivery of triamcinolone acetonide: a preliminary study in hairless rats.

Transdermal iontophoretic delivery of triamcinolone acetonide was examined using a commercially available iontophoretic system (Phoresor, Iomed) in hairless rats. A drug electrode containing triamcinolone acetonide 10 mg dissolved in 1 ml of N,N-dimethylacetamide and water (7/3 v/v) was connected to the positive pole of a Phoresor (set at 4 mA) and direct current was applied for 10, 30, or 90 minutes. The amount delivered to the skin tissues increased with time at a constant rate. Even after the drug electrode had been removed, triamcinolone acetonide was retained in the local skin tissues beneath where it had been for about 24 hours after 30 minutes iontophoresis. These results suggest that the iontophoresis with an organic solvent used as a drug vehicle is useful to increase transdermal absorption of compounds that do not dissolve completely in water.

Administration, Topical↗
PubMed1996

[Clinical treatment with cisplatin (CDDP) in pleural cavity for carcinomatous pleurisy--study of intraarterial concentration].

We investigated the intraarterial concentration of CDDP following continuous hyperthermic pleural perfusion (CHPP, 43 degrees C for 30 to 60 minutes) with 100 mg CDDP diluted in distilled water or saline in 6 lung cancers (2 pleural dissemination, 1 malignant pleural effusion, 3 positive wash cytology), 2 metastatic lung cancer (from breast cancer, 1 rhabdomyosarcoma with pleural dissemination), and 1 metastatic pleural tumor (adenocarcinoma, unknown origin). The level of CDDP was 9.16 to 24.1 micrograms/ml (average 16.1) in perfusion fluid, 0.3 after 5 minutes, 0.41 to 0.85 after 60 minutes and 0.15 to 0.27 (average 0.22) after 24 hours. There were no severe side effects nor any difference in effects by dilution fluid between distilled water and saline. Only 1 patient suffered pleural effusion after this treatment. The results suggested that CHPP with CDDP diluted by saline was effective for prevention and treatment of pleural dissemination.

Aged↗
PubMed1995

Clinical evaluation of a monoclonal antibody to serum KM01 for the diagnosis of hepatocellular carcinoma.

In order to evaluate a monoclonal antibody KM01 which was developed in mice immunized against a human colon carcinoma cell line, serum levels of KM01 and other tumor markers were studied in patients with both hepatocellular carcinoma and liver cirrhosis and in patients with liver cirrhosis alone. The KM01 levels in the sera of 50 patients with hepatocellular carcinoma plus liver cirrhosis and 50 patients with liver cirrhosis were measured using an enzyme immunoassay method and compared with various tumor markers including alpha-fetoprotein (AFP), DUPAN-2, and protein induced vitamin K absence or antagonist-II (PIVKA-II). The mean serum level (+/- S.D.) and sensitivity of KM01 in patients with hepatocellular carcinoma plus liver cirrhosis were 734 (+/- 716) units/ml and 64%, respectively, and they were significantly higher than those of liver cirrhosis patients (P < 0.001). Three out of 9 cases showing negative serum AFP levels had positive serum KM01 levels. Although the sensitivity of serum KM01 level for hepatocellular carcinoma was inferior to serum AFP and plasma PIVKA-II values, the sensitivity of a combination assay of serum KM01 or AFP was increased to 88%. Clinical data of the patients with markedly elevated serum KM01 levels (more than 1000 units/ml) were compared with patients with moderately elevated levels (530-1000 units/ml); serum bilirubin and alkaline-phosphatase were statistically higher in the former group (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Quantitative assessment of the autonomic nervous system activities during atropine-induced bradycardia by heart rate spectral analysis.

Using power spectral analysis of heart rate fluctuation, autonomic nervous system activities in bradycardia appearing in the initial phase of atropine administration were evaluated quantitatively in 16 healthy females. Atropine sulfate (10 micrograms/kg), diluted in 100 ml of 0.9% NaCl solution, was intravenously infused at a rate of 0.5 micrograms/kg per min. Electrocardiograms were sampled for 4 min for later analysis before and 0, 5, 10, 15 and 20 min after initiation of atropine infusion. Powers of low (LFC, 0.05-0.15 Hz) and high-frequency (HFC, 0.15-0.4 Hz) components in the power spectrum of R-R interval variations, and the LFC/HFC ratio were determined at each sampling point. HFC power at 0-4 min increased from 1.11 +/- 0.18 ms2 (mean) of baseline value to 1.37 +/- 0.19 ms2 (P < 0.05). The next 5-9-min value of 1.48 +/- 0.14 ms2 was the maximum, and the amount of atropine infused by 9 min was 4.5 micrograms/kg. The HFC powers following this point decreased. The 20-24-min value after 10 micrograms/kg atropine decreased to 0.21 +/- 0.03 ms2 (P < 0.01), which was lower than the previous 15-19-min value of 0.36 +/- 0.04 ms2 (P < 0.01). The LFC/HFC ratios showed no significant change for the initial 9 min of the atropine infusion. However, these ratios at 15-19 min and 20-24 min were increased from 0.50 +/- 0.04 (mean) of baseline value to 0.75 +/- 0.09 and 0.81 +/- 0.09, respectively (P < 0.01). A transient vagotonic state after atropine administration, followed by the well-known vagolytic state, was quantitatively detected by non-invasive spectral analysis of heart-rate fluctuation.

Adolescent↗
PubMed1995

Superior nerve anastomosis using a low-output CO2 laser on fibrin membrane.

BACKGROUND AND OBJECTIVE: To date, no procedure of laser-aided nerve anastomosis has yet proved to be consistently superior to suture nerve repair. This study examines a new method for nerve repair using a low output CO2 laser and fibrin membrane to ascertain the efficacy of this method for nerve regeneration in comparison with the suture method. STUDY DESIGN/MATERIALS AND METHODS: Both sciatic nerves of 42 Wister rats were used. The left sciatic nerves were cut and reconnected using 70 mW of irradiation on fibrin membrane bridging the nerve stumps, whereas the right sciatic nerves were repaired with two stitches of epineuro-fascicular sutures. RESULTS: No deleterious effect of the irradiation on nerve regeneration was demonstrated at any time after surgery. The number of myelinated axons larger than 5 microns in diameter and the mean diameter of mylinated axons 8 weeks after surgery were significantly larger in the laser group than those in the suture group (P < 0.05). CONCLUSION: The results suggest this new method may be useful and effective for clinical nerve repair.

Anastomosis, Surgical↗
PubMed1995

Immune response to fresh meniscal allografts in mice.

To date, no study of allogeneic meniscal transplantation has investigated both the host cellular immune response and the humoral immune response. Using inbred mice, we examined cellular and humoral immunity to meniscal allografts through the mixed lymphocyte culture reaction and a complement-dependent cytotoxicity test. We also examined the histology of an allogeneic meniscus transplanted subcutaneously. The stimulation index of the mixed lymphocyte culture seen after placing fresh meniscal allografts subcutaneously was not significantly higher than when isograft controls were similarly placed. Following placement of the allografts, no specific antibodies were detected in serum throughout the 24-week period after grafting. Although viable fibrochondrocytes in the allogeneic meniscus decreased in number and lymphocyte infiltration around the allogeneic meniscus was noted at Week 2, no remarkable infiltration of lymphocytes into the meniscus was observed. These results indicate that in our experimental mouse model, a fresh meniscus apparently is not sufficiently immunogenic to induce a systemic reaction. Our results suggest that a fresh allogeneic meniscus can be transplanted without any special treatment to decrease its immunogenicity.

Animals↗
PubMed1995

Allogeneic deep frozen meniscal graft for repair of osteochondral defects in the knee joint.

Osteochondral defects in the knee joints of five patients caused by trauma or osteochondritis dissecans were repaired using deep-frozen allogeneic meniscal grafts. Three patients were male and two were female, with a mean age of 26.4 years. The mean follow-up period was 31 months. Postoperative magnetic resonance imaging (MRI) at all periods clearly showed a smooth and congruous articular surface, although the signal intensity of the grafted meniscus was not the same as that of the articular cartilage. Second-look arthroscopy performed approximately 1 year after surgery demonstrated that the grafted meniscus was well bonded to the grafted site, not sunken; there was no gap between the grafted meniscus and the surrounding articular cartilage, indicating that the grafted meniscus functions as a part of the articular surface. Histologic examination revealed that host cells had infiltrated into the meniscus and that cells surrounded by thin collagen fibrils were morphologically similar to fibrochondrocytes. Thus, the acellular grafted meniscus regenerated as meniscal tissue and formed an articular surface, although hyalinization did not occur. Our results suggest that deep-frozen allogeneic meniscal grafting is a useful method to repair osteochondral defects in the knee joint.

Adolescent↗
PubMed1995

Serum markers for connective tissue turnover in patients with chronic hepatitis B and chronic hepatitis C: a comparative analysis.

BACKGROUND/AIMS: Clinical and pathological differences between chronic hepatitis B and chronic hepatitis C have now been established. METHODS: To compare hepatic connective tissue metabolism in chronic hepatitis B and C, we determined serum levels of prolyl 4-hydroxylase beta-subunit, procollagen III aminoterminal peptide, type IV collagen 7S domain, the central helix region of type IV collagen, tissue inhibitor of metalloproteinase, and hyaluronan in 55 patients with chronic hepatitis B and 83 patients with chronic hepatitis C. RESULTS: There were no significant differences in the above markers for connective tissue turnover between the chronic hepatitis B group and the chronic hepatitis C group. CONCLUSIONS: These results suggest that the accelerated connective tissue metabolism observed in chronic viral hepatitis is independent of the causative virus.

Adult↗
PubMed1995

Promotion of sciatic nerve regeneration in rats by a new neurotrophic pyrimidine derivative MS-430.

1. The effects of a new neurotrophic pyrimidine derivative of MS-430 on nerve regeneration was examined using Wistar rats whose left sciatic nerve had been subjected to controlled injury. 2. The functional recovery and the packing density of common peroneal nerve axons were significantly enhanced with the administration of 3 mg/kg/day of MS-430. 3. These results suggest that MS-430 is a promising candidate as a neurotrophic drug for clinical use.

Animals↗
PubMed1995

Treatment of articular defects with meniscal allografts in a rabbit knee model.

Deep-frozen allogeneic meniscal grafts for the treatment of articular cartilage defects were performed experimentally. Osteochondral defects 3 mm in diameter were created bilaterally on the medial femoral condyles of 50 Japanese white rabbits. A meniscus was then grafted into the defect in the left knee, and the right knee was left untreated. At various periods from 2 to 24 weeks postoperatively, the rabbits were killed and macroscopic and histologic examinations were performed. Two weeks after operation, the grafted meniscus was bonded to the floor of the defect. After 12 weeks, chondrocytes producing matrix granules was shown by electron microscopy. After 24 weeks, a congruous articular surface was formed. With time, cellular elements infiltrated into the graft from the surrounding tissues, and gradually increased in penetration. Weight bearing in the early stage after operation did not degrade the grafted menisci, and no changes were shown in the opposing cartilage of the tibia. Deep-frozen allogeneic menisci may be useful as a biological implant to repair articular cartilage defects in this model.

Animals↗
PubMed1995

Survival and development of reimplanted fetal epiphyses. An experimental study.

An experiment was undertaken to study the survival and development of fetal epiphyses after excision and reimplantation in rats. The proximal part of fibula in the hindlimb was dissected free from surrounding tissues and then reimplanted again. Of 80 fetuses that were operated on, nine that had been operated on survived to birth. Histological examination on the hindlimbs of these rats at four and six weeks after birth showed that the reimplanted segments survived, and the bony nuclei of the epiphyses were present. Radiographically, at 6 weeks old, secondary centres of ossification at proximal ends of the fibulas could be seen in both operated and normal limbs. These results indicate the clinical possibility of correcting congenital musculoskeletal abnormalities in the future by in utero transplantation of epiphyses.

Animals↗
PubMed1995

High intrinsic healing potential of human anterior cruciate ligament. Organ culture experiments.

We studied the intrinsic healing capacity of human semitendinosus tendon specimens, comparing them to human anterior cruciate ligament specimens collected at the time of ligament reconstructions, and using an organ culture model. On the day after cultivation, migration of cells and synthesis of collagen fibers were observed in the ligament group with preserved synovium (PS), the ligament group with resected synovium (RS), and the semitendinosus tendon group (ST). Migrating cells and newly-formed collagen fibers were most prominent in the PS group, followed by the RS, and ST groups. When the area occupied by the migrating cells and newly-formed collagen fibers in the prepared hole was measured, no differences were observed between the groups at week 2. However, differences were noted between the ST and PS or RS groups at weeks 4 and 6. Our findings indicate that the human anterior cruciate ligament possesses a high intrinsic healing capacity. It is also suggested that the synovium plays an important role in enhancing ligament healing capacity.

Adolescent↗