Biomedical subjects

Y Nihei

Publications and source records attributed to Y Nihei.

At least 19 recordsLinked to original sources

PubMed2006

Simultaneous colorectal and liver resections for synchronous colorectal metastases.

BACKGROUND: The surgical strategy for the treatment of colorectal cancer and synchronous hepatic metastases remains controversial. Many surgeons fear anastomotic leakage and intraperitoneal abscesses when performing a one-step procedure. They prefer a two-step procedure with a liver resection 2 to 3 months after resection of the colorectal primary lesion. SUBJECTS AND METHODS: We analysed medical records from April 1994 to April 2002 for a total of 42 patients with colorectal cancer and synchronous liver metastases who underwent simultaneous liver and colorectal resections with a primary anastomosis. Special attention was paid to data on surgical procedures, postoperative morbidity, and mortality. RESULTS: Forty-two patients, 24 men and 18 women, were studied. Median operating time was 6.50 hours (3.75-11.0 hours), and median blood loss was 1522 ml (range 288 to 5650 ml). Postoperative complications included pleural effusion in 4 patients, ileus in 3, anastomotic leakage in 2, intraperitoneal pelvic abscesses in 1, pneumonia in 1, bile leakage in 1, atelectasis in 1, and wound infection in 1. There was no perioperative mortality. CONCLUSION: Simultaneous colorectal resection with a primary anastomosis and hepatectomy for synchronous liver metastases is considered a safe procedure.

Adult↗

PubMed2002

Differential photoelectron holography: a new approach for three-dimensional atomic imaging.

We propose differential holography as a method to overcome the long-standing forward-scattering problem in photoelectron holography and related techniques for the three-dimensional imaging of atoms. Atomic images reconstructed from experimental and theoretical Cu 3p holograms from Cu(001) demonstrate that this method suppresses strong forward-scattering effects so as to yield more accurate three-dimensional images of side- and backscattering atoms.

Journal Article↗

PubMed1999

Stahl's ear caused by an abnormal intrinsic auricular muscle.

Stahl's ear in a 12-year-old girl was treated surgically. During the operation, we discovered that the transverse muscle had an abnormal course, and we concluded that this muscle had caused the deformity. Treatment was accomplished by cartilage incision and transposition of the muscle to its normal position. After 3 years of follow-up, the reconstructed ear has maintained a good appearance. The etiology of Stahl's ear is unknown. Although various techniques have been reported for the reconstruction of Stahl's ear, the course of the intrinsic auricular muscles have not been confirmed by surgeons during the operation. We think that this case provides insight into the etiology of Stahl's ear and provides guidance for a new surgical treatment.

Child↗

PubMed1999

Functional reconstruction using a depressor anguli oris musculocutaneous flap for large lower lip defects, especially for elderly patients.

Described here is a new technique to reconstruct large lower lip defects using one or two musculocutaneous island flaps, which includes an innervated depressor anguli oris muscle and has a facial artery in its pedicle. Vermilion is simultaneously reconstructed using a mucosal transposition flap. Three patients who had a total lower lip defect and five patients who had a defect larger than one-half of the lower lip were treated by our procedure. All the flaps survived completely without any signs of vascular stasis. In six patients, sphincter function and sensation appeared within 3 months after surgery. In one patient who needed a total lower lip reconstruction, the depressor anguli oris muscle was atrophic and the motor nerve could not be found. This patient could not regain motion. One other patient complained of a sialorrhea accompanied by sensory loss; however, his sensation improved within 6 months after surgery. All of the reconstructed lower lips were large enough to enable the patient to wear dentures and were of a cosmetically acceptable appearance 1 year after surgery.

Aged↗

PubMed1999

Cutaneous mucinous nodules associated with proliferating synovitis of rheumatoid arthritis.

Rheumatoid arthritis (RA) is occasionally associated with specific or non-specific cutaneous conditions. In this report, we describe unusual cutaneous nodules arising on the skin overlying the inflamed joints of two patients with RA. The nodules were histopathologically characterized by mucinous granulation tissue associated with neutrophilic infiltration and proliferation of starry-shaped mesenchymal cells. The affected joints of both cases showed synovitis with synovial tissue hyperplasia due to RA. Because hyaluronic mucin, which is the major component of synovial fluids, was deposited in the nodules, intradermal inoculation of synovial cells seemed to be responsible for the nodular development. The nodules of one patient spontaneously resolved in several months. We are unaware of any report describing similar cases. Such nodules should be included as a cutaneous complication of RA, distinct from neoplasias.

Aged↗

PubMed1999

Evaluation of antivascular and antimitotic effects of tubulin binding agents in solid tumor therapy.

Tubulin binding agents (TBAs) reduce tumor perfusion and inhibit mitosis of tumor cells in solid tumors, but it is not clear which effects contribute to the suppression of solid tumor growth. We evaluated the antivascular and antimitotic effects of several TBAs, combretastatin A-4 (CS A-4) phosphate, AC-7700, a novel CS A-4 derivative, colchicine, E7010, and vinblastine, on subcutaneous (s.c.) murine colon26 adenocarcinoma (c26). Tolerable doses of vinblastine and E7010) strongly inhibited tumor growth and induced mitotic arrest of tumor cells without affecting tumor perfusion. Colchicine had no effect on tumor growth and perfusion. When the injected dose was increased to the lethal range, however, these drugs markedly reduced tumor perfusion and caused necrosis of tumor tissue. Within the tolerable dose range, AC-7700 both strongly suppressed tumor growth and reduced tumor perfusion, and CS A-4 phosphate also exhibited a moderate antivascular effect. To evaluate the contribution of antivascular activity of TBAs to tumor growth suppression, excluding their direct cytotoxic effect on tumor cells, we established c26/acr, which is resistant to TBAs in vitro. Although E7010 showed a reduced suppressive effect on s.c. c26/acr tumor growth as compared with its effect on wild-type c26, AC-7700 remained potent against both cell lines. These results indicate that TBAs exert antivascular and antimitotic effects on solid tumors with marked differently effective dose ranges from agent to agent, and that the antivascular effect of TBAs inhibits solid tumor growth independently of the direct cytotoxic effect on tumor cells.

Adenocarcinoma↗

PubMed1999

A novel combretastatin A-4 derivative, AC-7700, shows marked antitumor activity against advanced solid tumors and orthotopically transplanted tumors.

AC-7700, a novel combretastatin A-4 derivative, suppresses the growth of solid tumors by inhibiting tumor perfusion. We evaluated the antitumor activity of AC-7700 on solid tumors in two experimental models, an advanced tumor model (murine colon 26 (c26) adenocarcinoma, colon 38 (c38) adenocarcinoma, MethA fibrosarcoma, Sarcoma 180 (S180), Lewis lung carcinoma (3LL), human LS180 adenocarcinoma) and an orthotopically transplanted tumor model (c26), compared with that of cisplatin (CDDP). The maximum tolerable dose (MTD) of CDDP suppressed early-stage c26 and c38 tumor growth when treatment was started after the tumor volume (TV) reached 0.2-0.5 cm3, but it showed reduced activity against the same tumors at an advanced growth stage when TV exceeded 2 cm3. At its MTD, AC-7700 was active against all tumors tested except 3LL in both early and advanced growth stages, reducing the tumor mass and having a curative effect in advanced c38 tumors. AC-7700 was also effective on orthotopically transplanted c26 tumors, showing a comparable activity to that on subcutaneous tumors. Unlike flavon acetic acid, which damages tumor vasculature by inducing endogenous tumor necrosis factor-alpha production, AC-7700 potently suppressed the growth of advanced c26 tumors in athymic as well as euthymic mice. These results suggest that AC-7700 is a novel antivascular agent that may have potent activity against advanced-stage cancer in the clinical setting.

Animals↗

PubMed1999

Antitumor effects due to irreversible stoppage of tumor tissue blood flow: evaluation of a novel combretastatin A-4 derivative, AC7700.

The relation between tumor tissue blood flow (tBF) reduction and antitumor effects was investigated. Changes in tBF of normal tissues (liver, kidney cortex, bone marrow and brain cortex) and tumors (Yoshida sarcoma subline, LY80 and Sato lung carcinoma, SLC) due to i.v. administration of AC7700 (1, 3, 10 mg/kg), one of the combretastatin A-4 derivatives, were measured with the hydrogen clearance method. The change in blood flow in tumor microfoci was also observed directly using a rat transparent chamber. Chemotherapy against the solid tumors (LY80, SLC) was performed by administering AC7700 7 times at intervals of 3 days and the effect on the tumor growth, the histological effect, the effect on lymph node metastasis and the survival rate were investigated. Tumor tBF showed a dose-dependent response to AC7700. Although tumor tBF decreased markedly at a dose of 1 mg/kg, it tended to recover partly within several hours. At 10 mg/kg, however, tumor tBF completely stopped within approximately 30 min and never recovered in many regions. The irreversible stoppage of tumor tBF was observed in large s.c. tumors and in microfoci as well. On the other hand, in normal tissues, tBF changes due to AC7700 were not uniform. In the liver, although tBF decreased by approximately 50% at 10 mg/kg AC7700, it recovered within 8 h. In the brain, although the mean maximum reduction was 35%, the blood flow recovered to the original level within 24 h. The blood flow in the kidney cortex did not change at all. In the bone marrow, tBF decreased by approximately 80%. Generally, the blood flow reduction in normal tissues tended to be reversible. The effect on tumor growth and the histological effect were also dependent on the dose of AC7700. The tumor growth was markedly inhibited by 10 mg/ kg AC7700 and extensive necrosis was induced. Lymph node metastases were significantly inhibited and survival was prolonged significantly. In the control group, all 8 SLC tumor-bearing rats died of cancer, the presence of which was verified by gross and microscopic evaluation, within 45 days after tumor implantation. On the other hand, in the treated group, 2 of 8 rats recovered completely and survived. No obvious side effects such as body weight loss, anemia or diarrhea were observed at the dose used in this experiment. From these results, we conclude that strong antitumor effects are obtained by stopping tumor tBF irreversibly and by shutting off the nutritional supply into tumor tissue. AC7700 has been demonstrated to be a promising anticancer compound which has such an action.

Animals↗

PubMed1999

Cytophagic histiocytic panniculitis improved by combined CHOP and cyclosporin A treatment.

In a 31-year-old Japanese man with cytophagic histiocytic panniculitis (CHP) remission was achieved by a combination of combined chemotherapy CHOP and cyclosporin A treatment. He was admitted to our hospital in January 1994 with recurrent high fever of 40.2 degrees C and tender and violaceous subcutaneous nodules on his trunk, arms and legs. He developed pancytopenia, hemorrhagic diathesis, liver dysfunction. Histological examination of the biopsied subcutaneous nodule revealed a lobular panniculitis with fat necrosis and a massive infiltration of histiocytes phagocytosing nuclear debris. He was treated initially with 40 mg/day prednisolone. However, following a reduction in prednisolone dosage, his symptoms reappeared. CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) therapy was then initiated. Three courses of CHOP treatment alleviated his symptoms and cyclosporin A was used to maintain his condition for 15 months. His medication was then discontinued and he has been in complete remission for 10 months. Combined treatment of cyclosporin A and CHOP combined chemotherapy was shown to be effective for this patient with severe CHP.

Adult↗

PubMed1999

Management of the hairline using a local flap in total reconstruction for microtia.

In cases of microtia with a low hairline, the manner in which hair is removed from the reconstructed auricle must be taken into consideration. This is one of the most common but difficult problems with reconstruction for microtia. The authors describe a new technique that uses a simple regional flap to resolve this problem. The hair-bearing skin in the estimated auricular region and its covering are removed using a local flap from the hairless mastoid region. This is done in the first stage of auricular reconstruction, the costal cartilage grafting is done in the second stage, and elevation of the auricle is done in the last stage. In 38 auricles of 36 patients who were treated from 1993 to 1995, eight auricles of eight patients were treated with this technique. In all cases, the hairless flap healed well, without vascular stasis or skin necrosis. In addition, no complications from using this technique occurred in the later stages of auricular reconstruction. With this technique, the skin of the flap provides a good texture and color match to the auricle. In addition, the skin of the flap has good elasticity for the cutaneous pocket for cartilage grafting. The harvested area of the flap can be hidden behind the reconstructed auricle. The authors initially wondered whether the marginal scar of the transposed flap's position in the auricle would be conspicuous. However, all of the scar became inconspicuous because it was positioned in the scaphoid fossa.

Adolescent↗

PubMed1999

Synthesis and antitumor activities of amino acid prodrugs of amino-combretastatins.

The synthesis and antitumor activity of water-soluble amino acid prodrugs of amino-combretastatins were reported. Among the synthesized compounds, 7e (CS-39-L-Ser HCI, AC-7700) showed enhanced antitumor activity and decreased toxicity in a Colon 26 murine adenocarcinoma model. Compound 7e showed improved solubility and was easily formulated for in vivo administration. Compound 7e was cleaved to generate the parent compound, CS-39, in the whole blood of mice as well as man, possibly by the action of amino peptidase on the erythrocyte membrane.

Animals↗

PubMed1998

Novel B-ring modified combretastatin analogues: syntheses and antineoplastic activity.

A series of B-ring modified combretastatin analogues were synthesized and their inhibitory activity against microtubule assembly, cytotoxic activity against Colon 26 adenocarcinoma cancer cell line were evaluated. Among these, pyridone derivative (19) showed strong antimitotic activity and cytotoxicity, along with excellent water-solubility.

Antineoplastic Agents, Phytogenic↗

PubMed1998

Syntheses and antitumor activity of cis-restricted combretastatins: 5-membered heterocyclic analogues.

A series of cis-restricted combretastatin analogues with 5-membered heterocycles were synthesized and their inhibitory activity against microtubule assembly and cytotoxic activity against the colon 26 adenocarcinoma cancer cell line were evaluated. Some of the heterocyclic analogues showed potent antitubulin activity and cytotoxicity. Compounds 16 and 35 showed marked tumor growth suppression in the colon 26 murine tumor model.

Animals↗

PubMed1998

Molecular cloning and developmental expression patterns of the MyoD and MEF2 families of muscle transcription factors in the carp.

cDNA clones encoding the myogenic regulatory factors (MRFs) myogenin, MyoD and myf-5 were isolated by reverse-transcription polymerase chain reaction from larvae and embryos of the common carp (Cyprinus carpio L.). Myocyte-specific enhancer factor 2 (MEF2) cDNAs were identified from a cDNA library from adult carp. Northern blot analysis showed that MyoD, myf-5 and MEF2C transcripts were present in three-somite embryos, whereas myogenin and MEF2A transcripts were not detected until the 15-somite stage. Intense signals of myogenin and MyoD transcripts were observed even in 1-month-old juveniles. Levels of MyoD, myogenin and MEF2A transcripts declined between 1 and 7 months after hatching, and myf-5 gave only a weak signal in the oldest fish. In contrast, levels of MEF2C transcripts were considerably higher in 7-month-old juveniles than in 1-month-old larvae. mRNAs encoding carp myosin heavy chain and -actin were first detected at approximately the time of the first heartbeat, and levels were maximal in juveniles 1 month post-hatching. The relatively high levels of MRF mRNA in juvenile fish probably reflect the recruitment of new muscle fibres from the satellite cell population. It was concluded that the relative importance of the different members of the MyoD and MEF2 families of transcription factors for muscle differentiation changes during ontogeny in the carp.

Journal Article↗

PubMed1998

Novel combretastatin analogues effective against murine solid tumors: design and structure-activity relationships.

A series of combretastatin A-4 (CA-4) analogues were synthesized, and their cytotoxic effects against murine Colon 26 adenocarcinoma and inhibitory activity on tubulin polymerization were evaluated. Since CA-4 has limited aqueous solubility, the target compounds were designed to improve solubility by introduction of a nitrogen-containing group. Among the compounds synthesized, those with an amino moiety in place of the phenolic OH of CA-4 showed potent antitubulin activity and cytotoxicity against murine Colon 26 adenocarcinoma in vitro. Some of the compounds which were potent in vitro were evaluated in the murine tumor model Colon 26 in vivo. Among these, 13bHCl, 21aHCl, and 21bHCl showed significant antitumor activity in the animal model, while CA-4 was ineffective. 13bHCl and 21aHCl were further evaluated in two murine tumor models (Colon 38 and 3LL) and human xenografts HCT-15. These compounds showed potent antitumor activity comparable or superior to that of CDDP. The structure-activity relationships of this series of compounds are also discussed.

Acrylonitrile↗

PubMed1998

Different growth properties in response to epidermal growth factor and interleukin-6 of primary keratinocytes derived from normal and psoriatic lesional skin.

Epidermal growth factor (EGF) family members and its receptor (EGFR) are thought to have an important role in the proliferation of epidermal keratinocytes. In this report, we investigated the EGF/EGFR system in primary keratinocytes derived from normal and psoriatic lesional skin. EGF elicited the growth of both normal human keratinocytes (NHKs) and psoriatic lesional keratinocytes (PLKs). Interleukin-6 (IL-6) potentiated the EGF-dependent growth of NHKs, but has no observable effect on PLKs, while IL-6 itself showed no growth-stimulating activities in both cell types. Immunodetection and in situ hybridization analyses revealed that IL-6 induces EGFR expression in NHKs in a time- and dose-dependent manner. This EGFR expression decreased reversibly to an undetectable level when IL-6-treated NHKs were re-cultured in IL-6-free conditions. On the other hand, PLKs expressed high levels of EGFR even when unstimulated and the expression level was not affected by IL-6 stimulation. These results suggest that the EGF/EGFR system is involved in the growth of NHKs and PLKs and that IL-6 potentiates NHK growth partly through the induction of EGFR. The different EGFR regulatory system may contribute to the pathogenesis of psoriasis.

Adult↗

PubMed1998

Non-traumatic rhabdomyolysis with gluteal ulcer.

The case is presented of a 34-year-old woman with rhabdomyolysis due to massive intake of nimetazepam, a benzodiazepine hypnotic. On admission, the patient had numerous blisters all over the body. One of the blisters in the gluteal region developed into a deep ulcer accompanied by muscle necrosis although it was not at a pressure point. The ulcer needed surgical intervention. Rhabdomyolysis is caused by the lysis and necrosis of muscle due to direct or indirect injury, high fever, ischaemia, hypoxia or enzyme defects. Release of myocyte components into the circulation then may induce major problems, especially acute renal failure associated with hypermyoglobinaemia. However, there have been few reports of cutaneous ulcer formation in non-traumatic rhabdomyolysis.

Adult↗

PubMed1998

Hydration and occlusive treatment of a sutured wound.

To evaluate the effects of surgical tape application to an incised wound after suture removal, a test using Micropore and Blenderm tape (3M, St. Paul, MN) was carried out. Eighteen patients with a sutured wound following surgery in the groin and extremities were divided into two groups. Each group was treated in one of the following ways for a period of 3 months: with Micropore, Blenderm, or with no treatment at all. After 3 months the plaster was removed and no further treatment was rendered. Evaluation of the scar was carried out for 6 to 9 months after surgery and the two areas were compared in each patient. In 13 groin wounds, better cosmetic results were achieved in the areas treated with Blenderm compared with the areas treated with Micropore or no treatment, although the difference was not significant. Better results were also observed on areas treated with Blenderm in 5 patients with scars on the extremities. The areas treated with Blenderm were less red and less hypertrophic than the areas treated with Micropore.

Abdomen↗