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Biomedical subjects

Kenji Kawamura

Publications and source records attributed to Kenji Kawamura.

At least 37 records · Page 2Linked to original sources
PubMed2005

Anatomy of Y-shaped configurations in the subscapular arterial system and clinical application to harvesting flow-through flaps.

BACKGROUND: A flow-through flap is useful in cases where the recipient artery must not be sacrificed. The aim of this study was to investigate Y-shaped configurations in the subscapular arterial system that can safely be used in harvesting a flow-through flap from the scapular region. METHODS: Sixteen dissections of the subscapular arterial system were carried out in eight embalmed cadavers. The origins and external diameters of branches in the subscapular arterial system were recorded. The distances between the origins of each branch were measured. RESULTS: The branches that showed a consistent presence and had a reliable diameter of more than 1.0 mm were the circumflex scapular artery, the bony branch of the circumflex scapular artery, the thoracodorsal artery, the angular branch, and branches to the serratus anterior and latissimus dorsi muscles. It was demonstrated that using the Y-shaped configuration between these branches enables the harvesting of a flow-through flap in various length versions of the Y-shaped vascular pedicles. A significant anatomical variation (i.e., both the thoracodorsal and circumflex scapular artery arose directly from the axillary artery) was found in three of 16 dissections. In this vascular variation, sacrificing the axillary artery must be avoided, so Y-shaped pedicles using the origin of the thoracodorsal or circumflex scapular artery cannot be created. On the basis of these results, flow-through flaps using this arterial system were applied in 10 patients for reconstruction of lower extremities, and satisfactory results were obtained. CONCLUSIONS: The results of our study are available for determining preoperatively and intraoperatively which Y-shaped configuration to use in harvesting a flow-through flap from the scapular region.

Adolescent↗
PubMed2005

Coverage of big toe defects after wrap-around flap transfer with a free soleus perforator flap.

In thumb reconstruction, a wrap-around flap transfer from the big toe gives excellent results aesthetically and functionally; however, there may be some problems at the donor site, such as delayed wound healing and skin ulceration. In 10 patients, a free soleus perforator flap was used for immediate coverage of defects of the big toe with wrap-around flap procedures. Eight flaps survived completely, and the time required for wound healing was less than 1 month. Two flaps developed partial necrosis and required additional skin grafts. The average follow-up period was 46 months. There were no patients requiring defatting of the flaps. There were no patient complaints, such as postoperative skin erosion or ulceration. All patients were satisfied with the outcome. A free soleus perforator flap is an available method for covering defects of the big toe after wrap-around flap transfer.

Adolescent↗
PubMed2005

Plexiform schwannoma of the ulnar nerve.

Plexiform schwannoma is a rare benign neurogenic tumour; we report a case that arose in the ulnar nerve of a 59-year-old woman. Exploration showed a continuous multinodular tumour that involved the ulnar nerve from the hand to the upper arm; the length of the tumour was 35 cm.

Biopsy, Needle↗
PubMed2005

Treatment of Kienböck disease in an 11-year-old girl with temporary fixation of the scaphotrapeziotrapezoidal joint.

An 11-year-old girl with Kienböck disease (stage IIIA) was treated by temporary scaphotrapeziotrapezoidal fixation. It was fixed in a cast for four weeks and wires removed after eight weeks. Follow up examinations showed that movement of the wrist and grip strength were improved, and she had no pain while revascularisation of the lunate could be seen on magnetic resonance imaging.

Arthrodesis↗
PubMed2005

Pisiform and hamate coalition: case report and review of literature.

Pisiform and hamate coalition is a rare anomaly of the carpal bones; a symptomatic case is an especially rare condition. We report a case of symptomatic pisiform and hamate coalition in a 15-year-old Japanese male. The literature of pisiform and hamate coalition is reviewed.

Accidental Falls↗
PubMed2005

Clinical applications of free soleus and peroneal perforator flaps.

Clinical applications of two free lateral leg perforator flaps are described: a free soleus perforator flap that is based on the musculocutaneous perforator vessels from one of the three main arteries in the proximal lateral lower leg, and a free peroneal perforator flap that is based on the septocutaneous or direct skin perforator vessels from the peroneal artery in the distal and middle thirds of the lateral lower leg. The authors applied free soleus perforator flaps to 18 patients and free peroneal perforator flaps to five patients with soft-tissue defects. The recipient site was the great toe in 14 patients, the hand and fingers in five patients, the leg in two patients, and the upper arm and the jaw in one patient each. The largest soleus perforator flap was 15 x 9 cm, and the largest peroneal perforator flap was 9 x 4 cm. Vascular pedicle lengths ranged from 6.5 to 10 cm in soleus perforator flaps and from 4 to 6 cm in peroneal perforator flaps. All flaps, except for the flap in one patient in the peroneal perforator flap series, survived completely. Advantages of these flaps are that there is no need to sacrifice any main artery in the lower leg, and there is minimal morbidity at the donor site. For patients with a small to medium soft-tissue defect, these free perforator flaps are useful.

Accidents, Occupational↗
PubMed2004

Heat shock induces neurite outgrowth in PC12m3 cells via the p38 mitogen-activated protein kinase pathway.

We investigated the role of the p38 mitogen-activated protein kinase (MAPK) pathway in heat-shock-induced neurite outgrowth of PC12 mutant cells in which nerve growth factor (NGF)-induced neurite outgrowth is impaired. When cultures of the PC12 mutant (PC12m3) cells were exposed to heat stress at 44 degrees C for 10 min, activity of p38 MAPK increased and neurite outgrowth was greatly enhanced. The neurite extension was inhibited by the p38 MAPK inhibitor BS203580. Longer heat treatment of PC12m3 cells provoked cell death, which was enhanced by SB203580. These findings suggest that heat-induced activation of p38 MAPK is responsible for the neurite outgrowth and survival of PC12m3 cells.

Animals↗
PubMed2004

Induction of centrosome amplification and chromosome instability in human bladder cancer cells by p53 mutation and cyclin E overexpression.

Centrosome amplification frequently occurs in human cancers and is a major cause of chromosome instability (CIN). In mouse cells, centrosome amplification can be readily induced by loss or mutational inactivation of p53. In human cells, however, silencing of endogenous p53 alone does not induce centrosome amplification or CIN, although high degrees of correlation between p53 mutation and CIN/centrosome amplification in human cancer can be detected, suggesting the presence of additional regulatory mechanism(s) in human cells that ensures the numeral integrity of centrosomes and genomic integrity. Cyclin E, a regulatory subunit for CDK2 that plays a key role in centrosome duplication, frequently is overexpressed in human cancers. We found that cyclin E overexpression, together with loss of p53, efficiently induces centrosome amplification and CIN in human bladder cancer cells but not by either cyclin E overexpression or loss of p53 alone. We extended these findings to bladder cancer specimens and found that centrosome amplification is strongly correlated with concomitant occurrence of cyclin E overexpression and p53 inactivation but not with either cyclin E overexpression or p53 inactivation alone. Because cyclin E expression is strictly controlled in human cells compared with mouse cells, our findings suggest that this stringent regulation of cyclin E expression plays an additional role underlying numeral homeostasis of centrosomes in human cells and that deregulation of cyclin E expression, together with inactivation of p53, results in centrosome amplification.

Aged↗
PubMed2004

Lack of evidence for reovirus infection in tissues from patients with biliary atresia and congenital dilatation of the bile duct.

BACKGROUND/AIMS: To clarify the association between the reovirus infection of the hepatobiliary tree and the development of infantile obstructive cholangiopathy (IOC) including biliary atresia (BA) and congenital dilatation of the bile duct (CBD). METHODS: We designed reovirus common primers for nested RT-PCR based on the L3 gene segment. The spectrum and the sensitivity of common primers were evaluated with purified reoviral RNAs and reovirus mixed with stool samples. Then, nested RT-PCRs were performed with hepatobiliary and fecal samples obtained from patients with BA, CBD, and control diseases. Additionally, electron microscopy of stool samples was performed. RESULTS: The L3 common primers could amplify cDNAs synthesized from RNAs of three prototypes of reovirus, and detect as much as 5.0x10(3) plaque forming unit of serotype 3 Dearing strain in 100 mg of fecal samples. However, no amplification product was detected in 136 hepatobiliary tissues taken from 67 patients including 26 BAs and 28 CBDs, or in 65 fecal samples obtained from 15 patients including 10 BAs and 1 CBD. Additionally, viral particles were not found in any stool specimens by the electron microscope. CONCLUSIONS: These data do not suggest that reoviruses play a major role in the etiology of IOC or BA.

Bile Ducts↗
PubMed2004

Vascularized fibular grafting in the treatment of methicillin-resistant Staphylococcus aureus osteomyelitis and infected nonunion.

Twenty patients with methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis and bone infection were treated with vascularized fibular grafts. There were 16 males and four females, and the patient ages at operation ranged from 17 to 73 years. Nine of the lesions affected the femur, eight the tibia, and there were three others. All of the patients were treated with extensive debridement of the lesions and local antibiotic therapy. Continuous local irrigation was applied in two patients, antibiotic-formulated bone cement in five, and both in 10 patients. Recurrence of local infection occurred in six patients, including one failed graft. Eventually, 18 of the 20 cases attained successful subsidence of the inflammation. The mean period required to obtain radiographic bone union was 7 months in the femoral reconstruction group, 6.1 months in the tibial reconstruction group, and 6 months in the remaining patients. The authors believe that vascularized fibular grafting is the most reliable procedure for the treatment of MRSA osteomyelitis and infected nonunion.

Adolescent↗
PubMed2004

Dysvascular lower extremity reconstruction using free flaps with a "Y" configuration of the arterial pedicle.

For patients with a dysvascular lower extremity, free flaps have been transferred by end-to-side anastomosis, in order to maintain peripheral circulation. For such patients, the authors have applied free flap transfers with a "Y" configuration of the arterial pedicle. Eight free flaps with a Y configuration of the arterial pedicle were used in seven patients: latissimus dorsi musculocutaneous flaps in six, and scapular flaps in two. For the former, flaps were harvested with the subscapular and circumflex scapular arteries forming a Y pedicle in three cases, and with the thoracodorsal artery and the branch of the serratus anterior muscle in three. For the scapular flap transfers, the flap was harvested with the subscapular and thoracodorsal arteries forming a Y pedicle in one case, and with the circumflex scapular artery and the descending branch in the other. This procedure was performed for single-artery extremities in two cases. One developed arterial thrombosis of the branch to the foot, but removal of the thrombus and reanastomosis resulted in peripheral blood circulation being maintained. Eventually, all flaps survived. This procedure is indicated in patients with lower-leg reconstruction, especially with vascular disease.

Adult↗
PubMed2004

Radial forearm flaps for reconstruction in hand surgery.

Thirty-seven patients were treated using distally-based island radial forearm flaps. There were 31 men and six women. Reconstructed sites involved the dorsum of the hand (n = 17), the thumb (n = 11), the fingers (n = 5), the first web (n = 3), and the palm (n = 1). Sensory flaps were transferred in 15 cases, osteocutaneous flaps in six, and tendocutaneous flaps in eight. All the flaps survived. There were five donor-site complications, but no functional disturbances. Three patients had symptoms of cold intolerance. There were no radial fractures. In the six cases with osteocutaneous flaps, a mean of 2.6 months (range 2-3) was needed to obtain bony union. Among the eight cases with tendocutaneous flaps, postoperative tenolysis was required in two cases, and finally seven achieved a satisfactory outcome. The mean moving 2-point discrimination of the sensory flaps was 13 mm.

Adult↗
PubMed2004

Radiocarpal arthrodesis for osteoarthritis following fractures of the distal radius.

To compare the radioscapholunate (RSL) arthrodesis and radiolunate (RL) arthrodesis as a treatment for radiocarpal osteoarthritis following fractures of the distal radius, nine patients, 23 to 70 years old (average 41) at the time of surgery, were assessed two to 33 years after surgery. The periods between injury and surgery ranged from four months to 30 years. RSL arthrodesis was performed in three cases and RL arthrodesis in six. Post-operative wrist pain disappeared in six and was decreased in the other three. In the RSL group, the total arc of wrist flexion and extension was reduced from 50 degrees pre-operatively to 35 degrees post-operatively. In the RL group, it was increased from 72 degrees to 76 degrees after surgery. Grip strength improved in most patients, from 7 to 18 kg in the RSL group, and from 16 to 27 kg in the RL group. On roentogenogram, three patients showed arthritic changes in the adjacent joints, but there were no symptoms in two of the three patients. We concluded that partial radiocarpal arthrodesis (preferably RL arthrodesis) is a reliable procedure for radiocarpal osteoarthritis following fractures of the distal radius.

Adult↗
PubMed2003

Electromyographic analysis of a modified maneuver for quadriceps femoris muscle setting with co-contraction of the hamstrings.

A "quadriceps femoris muscle setting" is isometric quadriceps femoris exercise which can be widely used in early knee rehabilitation. However this exercise cannot obtain enough co-contraction of the hamstrings. Isolated quadriceps femoris contraction in knee extension imposes severe strain to anterior cruciate ligament. We succeeded in developing a simple training maneuver that is effective in obtaining co-contraction of the hamstrings--a modified maneuver for the quadriceps femoris muscle setting with the contralateral lower limb raised (MQS). In this study, we analyzed the effect of this maneuver by EMG quantification. Twenty-eight healthy young adult men performed sequential trials consisting of normal quadriceps femoris muscle setting (NQS) and MQS. Electromyographic activity was recorded from surface electrodes on the gluteus maximus, vastus medialis, rectus femoris, vastus lateralis, semitendinosus and biceps femoris (long head), and normalized to values derived from maximal isometric trials. The % maximal voluntary isometric contraction (%MVIC) of the vastus medialis, vastus lateralis and rectus femoris did not vary in the each maneuver. However, the %MVIC of the hamstrings varied significantly in the MQS. This study suggests that effective co-contraction of the hamstrings can be obtained in MQS by adjusting the load to the raised lower limb.

Adult↗
PubMed2003

[Centrosome isolation from cultured bladder cancer cells--p53 mutation and centrosome hyperamplification].

Centrosome hyperamplification occurs frequently in human cancers, and is the major contributing factor for chromosomal instability and aneuploidy. We examined centrosome hyperamplification in bladder cancer cell lines. Samples were incubated with antibodies to the centrosome protein gamma-tubulin. The cell line (RT-4), which has a wild-type p53 status, showed a well-regulated centrosome replication cycle. On the other hand, centrosome hyperamplification was observed in HT-1197 and HT-13r cancer cells by discontinuous sucrose gradient fractionation. We used sucrose gradient fractions enriched for centrosomes by the immunoblot analysis for the presence of gamma-tubulin, a major component of centrosomes. The fractions were then immunoblotted with anti-nucleophosmin/B23 (NPM) antibody. NPM is a primary target of CDK2-cyclin E in the initiation of centrosome duplication. The profile of NPM closely paralleled that of gamma-tubulin, suggesting the association of NPM with the centrosome. Identification of the mechanism underlying the replication of the centrosome should lead to the understanding of the mechanism of chromosomal instability in bladder cancer, and enable us to develop cancer therapeutics targeted to centrosome replication.

Centrosome↗
PubMed2002

Immunosuppressant FK506 induces neurite outgrowth in PC12 mutant cells with impaired NGF-promoted neuritogenesis via a novel MAP kinase signaling pathway.

We obtained a drug-hypersensitive PC12 mutant cell (PC12m3), in which neurite outgrowth was strongly stimulated by various drugs such as FK506, calcimycin and cAMP, under the condition of NGF treatment. The frequency of neurite outgrowth stimulated by FK506 was approximately 40 times greater than by NGF alone. The effects of FK506 on neurite outgrowth in PC12m3 cells were inhibited by rapamycin, an FK506 antagonist, and by calcimycin, a calcium ionophore. PC12m3 cells had a strong NGF-induced MAP kinase activity, the same as PC12 parental cells. However, FK506-induced MAP kinase activity was detected only in PC12m3 cells. The activation of MAP kinase by FK506 in PC12m3 cells was markedly inhibited by rapamicin and calcimycin. FK506-induced MAP kinase activity was also inhibited by MAP kinase inhibitor U0126. These results demonstrate that drug-hypersensitive PC12m3 cells have a novel FK506-induced MAP kinase pathway for neuritogenesis.

Animals↗
PubMed2002

Proliferative activity of renal cell carcinoma associated with acquired cystic disease of the kidney: comparison with typical renal cell carcinoma.

To assess the proliferative activity of renal cell carcinoma (RCC-A) in patients with acquired cystic disease of the kidney (ACDK) after long-term hemodialysis, we analyzed cell cycle, DNA ploidy, and S-phase fraction by flow cytometry (FCM) and proliferating cell nuclear antigen (PCNA) labeling index by immunohistochemistry. The data were compared with those of typical RCC (tRCC). Sixteen (88.9%) of 18 RCC-As showed a diploid pattern. The values of cells at each phase in the cell cycle in RCC-A group (S, 4.36% + 2.16%; G2M, 5.06% + 1.90%; S+G2M, 9.41% + 2.81%; P <.05) were significantly different from those of tRCCs (S, 8.91% + 6.58%; G2M, 8.77% + 5.73%; S+G2M; 17.67% + 7.61%). The PCNA labeling index was statistically significantly lower in the RCC-As (24.01% +/- 13.4%; P <.05) than in tRCCs (42.27% +/- 26.1%). These results indicate that the RCC-As are less proliferative than tRCC and are consistent with the observation that RCC-As are less aggressive neoplasms.

Adult↗