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Biomedical subjects

K Ohmori

Publications and source records attributed to K Ohmori.

At least 181 records · Page 10Linked to original sources
PubMed1998

[Two cases of delayed ureteral fistulas following rectal amputation].

We report two rare cases of delayed ureteral fistulas which occurred one month following rectal amputation. Case 1 was a 52-year-old male who underwent abdominal perineal resection of the rectum. One month after surgery, the patient had a paralytic ileus. Computed tomographic (CT) scan and drip infusion pyelography showed left ureteral fistula and a large pelvic urinoma. Because retrograde placement of a double-J stent was unsuccessful, antegrade placement of the double-J stent was performed. The fistula and urinoma healed soon after the placement of the double J stent. Case 2 was a 43-year-old male who underwent abdominal sacral resection of the rectum. One month after surgery, a large amount of urine began to drain from the perineal wound. CT scan and retrograde pyelography showed a right ureteral fistula and a large pelvic urinoma. There had been temporary improvement in the discharge without the treatment of the ureteral fistula, only for it to return more profusely. Because placement of a double-J stent was unsuccessful, right percutaneous nephrostomy was performed, after which, a right ureterocysto-neostomy (Boari flap method) was performed. We advocate the initial use of the double-J stent or percutaneous nephrostomy in ureteral fistula. This approach is simple and may cure the fistula. If unsuccessful, it will not hinder subsequent open surgery.

Anastomosis, Surgical↗
PubMed1998

[A case of clear cell adenocarcinoma of the female urethra].

Clear cell adenocarcinoma of the female urethra is a rare disease. We herein report the 23rd case of clear cell adenocarcinoma of the female urethra in Japan. A 75-year-old female visited our hospital because of pollakisuria. Pelvic CT revealed a 2.2 cm tumor surrounding the entire circumference of the urethra with pelvic lymph node metastases. Chest CT revealed mediastinal lymph node metastases. She underwent anterior pelvic exenteration and ileal conduit urinary diversion. Pathological diagnosis of the tumor was clear cell adenocarcinoma. She has been alive 11 months after surgery in spite of enlarged mediastinal lymph node metastases.

Adenocarcinoma, Clear Cell↗
PubMed1998

Finite element analysis of the lower lumbar neural arch under facet loading.

To evaluate the mechanical effect of the direction of facet load on the isthmus stresses of the lower lumbar neural arch, stress analyses were performed by using three-dimensional finite element models of isolated L4 and L5 vertebrae with particular emphasis on accurate discretization of the posterior elements. The bilateral symmetric or unilateral facet loads, with a constant magnitude, were applied within the sagittal and transverse planes. The largest maximal principal stress in the neural arch (the largest sigma(max)) tended to be qualitatively similar in L4 and L5. At the physiologic range, the largest sigma(max), observed on the anterior surface of the isthmus, was relatively insensitive to the sagittal plane loadings but sensitive to the transverse plane loadings. The values of the largest sigma(max) of L4 and L5 were low at the more frontally directed facet load. The magnitude and direction of the largest sigma(max) depended upon the facet loadings mainly on the ipsilateral side and partly on the opposite side. The results suggest that the direction of facet load, which may be characterized by the facet orientation, can have mechanical effects on the occurrence and direction of isthmic crack.

Computer Simulation↗
PubMed1998

[Clinical results of transurethral electrovaporization of prostate (TVP) with two vaporization electrodes].

Transurethral electrovaporization of the prostate (TVP) is a new minimally invasive procedure for treatment of enlargement of prostate. Between April 1996 and September 1997, TVP was carried out in 109 cases with symptoms of lower urinary tract obstruction. A Stortz spike electrode and a Stortz vapor cutting electrode were used for vaporization electrodes. Efficacy parameters evaluated included International Prostate Symptom Score, peak uroflow and postvoid residual volume. By September 1997, 32 cases (spike electrode) and 33 cases (vapor cutting electrode) could be followed up and evaluated. They have shown both subjective and objective voiding improvement. The improvements in subjective symptom scores and objective voiding parameters were not significantly different between the two electrode groups. Early complications included urinary retention, intraoperative burn, stress incontinence, blood transfusion and postoperative hemorrhage. Late complications included urethral stricture, bladder neck contracture and bladder stone. TVP was found to have several advantages, particularly minimal bleeding and the low incidence of postoperative morbidity. The technique is simple and symptoms improve at an early stage following surgery. This study demonstrates that TVP is a safe and effective modality for treatment of BPH. However, long-term studies with larger numbers of patients are needed.

Aged↗
PubMed1998

[Primary adenocarcinoma of the renal pelvis in a young male: a case report].

The patient was a 16-year-old male who visited our hospital with the chief complaint of microhematuria. Computed tomography revealed left hydronephrosis, renal stones and left renal tumor. Needle biopsy was performed under ultrasonography. The histological diagnosis was adenocarcinoma and left radical nephrectomy was performed. The histological diagnosis was mucinous adenocarcinoma of the renal pelvis. Postoperative chemotherapy was not given. The patient has had neither recurrence nor metastasis for 1 year following surgery. This is the 92nd reported case in the literature.

Adenocarcinoma↗
PubMed1997

Adenovirus-mediated gene transfer of C-type natriuretic peptide causes G1 growth inhibition of cultured vascular smooth muscle cells.

We have proposed the "vascular natriuretic peptide system", in which C-type natriuretic peptide (CNP), the third member of the natriuretic peptide family, can control vascular tone and growth as an endothelium-derived relaxing peptide. We aimed at overexpression of CNP gene in vascular smooth muscle cells (SMCs) by adenovirus-mediated gene transfer to examine the growth characteristics of SMCs via the augmentation of cGMP production. Rat aortic SMCs infected with Ad.CNP, a replication-deficient adenovirus driving rat CNP cDNA, produced 162 +/- 55 fmol/mL of CNP, which was 4,000 times higher than that produced by endothelial cells. cGMP production was also augmented in Ad.CNP-infected SMCs (2200 +/- 270 fmol/10(4) cells). Accordingly, significant growth inhibition was observed in SMCs infected with Ad.CNP. The flow cytometry analysis revealed that the population of the S and G2 + M phases was reduced by 60% of the control in Ad.CNP-infected SMCs. The gene expression of ANP-B receptor, which is expressed abundantly in SMCs with the synthetic phenotype, was suppressed in Ad.CNP-infected SMCs, while the gene expression of ANP-A receptor, which is expressed predominantly in SMCs with the contractile phenotype, became detectable in Ad.CNP-infected SMCs. In addition, the gene expression of smooth muscle myosin heavy chain-2 (SM-2), which is the molecular marker of highly-differentiated SMCs, was also induced in Ad.CNP-treated SMCs. These results suggest that cGMP cascade activation induces re-differentiation of SMCs. The present study demonstrated that overexpression of CNP induced growth inhibition of SMCs at the G1 phase with possible alteration of the phenotype.

Adenoviridae↗
PubMed1997

Anti-inflammatory and bronchodilator properties of KF19514, a phosphodiesterase 4 and 1 inhibitor.

We investigated the effects of KF19514 (5-phenyl-3-(3-pyridyl)methyl-3H-imidazo[4,5-c][1,8]naphthyridin-4 (5H)-one) on bronchoconstriction and allergic inflammation in guinea pigs and on tumor necrosis factor-alpha production in mice. KF19514 inhibited phosphodiesterase 4 (IC50 = 0.40 microM) and phosphodiesterase 1 (IC50 = 0.27 microM) derived from canine tracheal smooth muscles. KF19514 relaxed contracted tracheal smooth muscle and had a potent inhibitory effect on antigen-induced bronchoconstriction (EC50 = 0.058 microM) in vitro. Intravenous administration of KF19514 inhibited histamine-induced bronchoconstriction (ID50 = 2.8 microg/kg i.v.). Moreover, oral administration of KF19514 inhibited anaphylactic bronchoconstriction (ID50 = 0.2 mg/kg p.o.), and eosinophil infiltration in airway stimulated with platelet-activating factor (PAF) or antigen. KF19514 also produced a significant inhibition of tumor necrosis factor-alpha production in mice (ID50 = 0.023 mg/kg p.o.). Finally, KF19514 completely inhibited antigen-induced hyperreactivity at 0.1 mg/kg p.o. These results demonstrate that KF19514 may have efficacy in the treatment of asthma.

Anaphylaxis↗
PubMed1997

Depressive symptoms in acute schizophrenic inpatients.

Prospective and longitudinal assessment of depressive, positive, and negative symptoms were performed on 86 newly admitted schizophrenic patients. The improvement of depressive symptoms was significantly correlated with the improvement in positive symptoms, but did not correlate with the improvement in negative symptoms. However, depressive symptoms were heterogeneous. Principal components analysis was used to subdivide depressive symptoms into five factors. The improvement of the depression-anxiety factor was significantly associated with improvement of positive symptoms. On the other hand, improvement of negative symptoms was significantly related to that of the reduced activity factor. The change in hypochondriasis had a significant positive correlation with the change in positive symptoms and had a significant negative correlation with the change in negative symptoms. Changes in the other factors of depressive symptoms did not appear to be associated with changes in positive or negative symptoms. The present findings suggest that the various depressive symptoms associated with acute schizophrenia may have different pathophysiological origins.

Adult↗
PubMed1997

Relation of contrast echo intensity and flow velocity to the amplification of contrast opacification produced by intermittent ultrasound transmission.

Intermittent ultrasound transmission during contrast echocardiography, so-called transient response imaging (TRI), amplifies contrast intensity. This effect of TRI is attributed to decreased microbubble destruction by reduced exposure time to ultrasound energy. The present study examined the hypothesis that the signal amplification produced by TRI is related to the baseline intensity present in the image and the velocity of flow. We performed second harmonic (2.5/5.0 MHz) imaging during both continuous (frame rate 55 Hz) and electrocardiogram-triggered TRI mode. Contrast images produced by perfluorohexane microbubbles (AF0150) in a steady flow model were obtained every minute throughout the decay phase at transit velocities of 8.1, 6.2, 3.4, 1.9, and 0.7 cm/sec. The decay of videointensity over time could be fitted to a sigmoid curve for both imaging modes with r > 0.99 for individual velocities. The intensity with TRI was greater than that with continuous imaging (CI) at any time and velocity. The mean increase in intensity between modes throughout decay was 8.2 +/- 3.7, 12.8 +/- 4.2, 25.7 +/- 5.8, 49.5 +/- 8.0, and 64.0 +/- 14.4 gray levels for the respective velocity levels studied (p < 0.0001). Although varying with baseline intensity at early and late phases, the TRI amplification plateaued during middecay, and within the intensity range of 16 to 143 gray levels for CI and 67 to 186 gray levels for TRI, it showed no overlap among the different velocity levels. Thus the ability of TRI to enhance contrast opacification is much greater at low flow velocities, which has implications regarding the mechanism of TRI effect and preferential visualization of intramyocardial coronary arteries by this agent. Although this effect was influenced by the baseline intensity, it was relatively constant for each velocity level within an optimal intensity range during middecay, providing the basis for flow velocity measurement by contrast echo.

Blood Flow Velocity↗
PubMed1997

Colour Doppler flow imaging of postauricular arteries and veins.

The posterior auricular vessels of both ears in 15 normal human adults were examined using a colour Doppler flow imager to investigate whether the imager might be helpful in preoperative assessment of the blood supply of the retroauricular skin. Thirty posterior auricular arteries and 23 posterior auricular veins were identified. A reversed arterial flow was observed in 15 out of 30 ears and a reversed venous flow was observed in 4 out of 30 ears after the blood flow of the vessel was stopped by applying pressure manually at the level of the mastoid process. The assessment of the size and location of the posterior auricular vessels with a colour Doppler flow imager is valuable in the planning of flaps based on these vessels. Furthermore, the observation of the reversed flow confirms the possibility of safe elevation of a posterior auricular flap based on the tributaries of the superficial temporal vessels.

Adult↗
PubMed1997

Reducing environment protects sinusoidal lymphocytes isolated from normal human liver from apoptosis.

BACKGROUND/AIMS: We previously reported that the populations of lymphocytes and the expression of activated antigens in human sinusoidal mononuclear cells were different from those in peripheral blood mononuclear cells. Attempts to culture these cells for further study failed because they died rapidly under standard culture conditions in vitro after isolation from the liver. In this study, we evaluated the characteristics of cell death and the effects of various culture conditions on the viability of these cells. METHODS: Sinusoidal mononuclear cells were isolated from University of Wisconsin solution that had been perfused through the portal veins of normal healthy human livers harvested for transplantation into living related recipients. RESULTS: 70% of sinusoidal mononuclear cells cultured in vitro were nonviable within 48 h after isolation, while only 10% of peripheral blood mononuclear cells died under the same conditions. Sinusoidal mononuclear cells showed DNA ladder formation of DNA on electrophoresis and characteristic morphological pattern on electron microscopic examination that suggested they had died in an apoptotic manner. The addition of human liver extracts or 2-mercaptoethanol and reduced glutathione to the cultures rescued the sinusoidal mononuclear cells from apoptosis. Furthermore, diamide, a sulfhydryl group specific oxidant, negated the effect of the liver extract. CONCLUSION: In comparison with peripheral blood mononuclear cells, human sinusoidal mononuclear cells were more subject to death by apoptosis ex vivo, which was reversed by exogenous agents producing reducing conditions. These results suggested that hepatic sinusoidal mononuclear cells might express a different sensitivity to redox environment than peripheral blood mononuclear cells.

Apoptosis↗
PubMed1997

Involvement of hepatocyte growth factor in increased integrin expression on HepG2 cells triggered by adhesion to endothelial cells.

Adhesion of cancer cells to vascular endothelium is an important step in haematogenous metastasis of cancer. A human hepatocellular carcinoma cell line, HepG2, strongly adheres to human umbilical vein endothelial cells (HUVECs) through the interaction of E-selectin and its carbohydrate ligand sialyl Lewis X. In this study, we investigated alteration in integrin expression on HepG2 cells, which follows the selectin-mediated initial adhesion of HepG2 cells to HUVECs. Expression of alpha2beta1 integrin was markedly increased when the HepG2 cells adhered to HUVECs. Among the tested cytokines that are known to be produced by endothelial cells, recombinant hepatocyte growth factor (rHGF) could replace the effect of HUVECs, and a similar increase in integrin expression was observed by the addition of 20 ng ml-1 rHGF to HepG2. The increment of alpha2beta1 integrin expression was significantly inhibited by anti-HGF neutralizing antibody treatment. HepG2 cells expressed alpha2, alpha6, beta1, and beta4 integrin subunits, but expression of integrins other than alpha2beta1 was not affected by the rHGF treatment. The rHGF treatment of HepG2 cells resulted in augmented adhesion to immobilized collagen. This augmentation in adhesion to collagen was completely blocked by the addition of anti-alpha2- or anti-beta1-integrin antibody. In double-chamber chemoinvasion experiments, transmigration of the HepG2 cells through extracellular matrix (ECM) gel was significantly accelerated by co-cultivation with HUVECs. A similar level of enhancement in transmigration activity of the cancer cells was observed by the addition of rHGF. Our interpretation of the results described above is that the cancer cells received stimulation from cytokines, such as HGF, presented by vascular endothelial cells, following the initial adhesion of cancer cells via selectins. This resulted in the secondary increment in the expression of cell adhesion molecules, such as the alpha2beta1 integrin, and led to the augmented adhesive activities of cancer cells towards extracellular matrices at vascular walls. We suggest that this sequence of events is involved in the facilitated migration of some cancer cells to extravascular tissues.

Antibodies↗
PubMed1997

Preferential localization of human CD5+ B cells in the peritoneal cavity.

In a transgenic mouse model of autoimmune haemolytic anaemia, CD5+ B lymphocytes localized in the peritoneal cavity are shown to play an important role in the onset of autoimmune disease. The authors have examined whether CD5+ B cells are present in the peritoneal cavity of 12 human individuals with non-invasive gastrointestinal tumours and found that in humans CD5+ B cells preferentially lodge in the peritoneal cavity as compared to the peripheral blood and spleen while the numbers of the peritoneal B lymphocytes in humans are much lower than in mice and vary widely between individuals.

Animals↗
PubMed1997

Evaluation of the prognosis of cancer patients with metastatic bone tumors based on serial bone scintigrams.

We counted the lesions at the time of detection of bone metastases and calculated the rate of increase in the number of bone metastases from changes in serial bone scintigrams, and investigated the usefulness of serial scintigrams as a prognostic indicator in patients with metastatic bone tumors. Subjects were 112 patients with bone metastases from four types of primary lesion: 21 with prostate cancer, 27 breast cancer, 39 lung cancer and 25 stomach cancer. Of these, 18 (prostate), 19 (breast), nine (lung) and eight (stomach) underwent serial bone scintigrams in which bone metastases were first detected and identified as progressing. The numbers of lesions at the time of detection of bone metastases for prostate and stomach cancers were significantly greater than those for lung cancer. The rate of increase in the number of bone metastases for stomach cancer was significantly higher than that for prostate or breast cancers. There was no correlation between the survival time after the detection of bone metastases and the number of lesions at the time of detection in the four types of cancer. However, in prostate cancer, a negative correlation existed between the survival time after the detection of bone metastases and the rate of increase in the number of bone metastases. Thus, in patients with bone metastases from prostate cancer, it appears that the rate of increase in the number of bone metastases, estimated from serial bone scintigrams, was indicative of prognosis.

Adult↗
PubMed1997

Medical canthoplasty with the Mitek Anchor System.

A variety of surgical techniques have been described for medial canthal tendon reattachment. They generally require technical skill and prolonged operating time. We have applied a new device, the Mitek Anchor System, in reattaching the medial canthal tendon to the medial orbital wall in 3 patients, and got excellent tendon fixation with this rapid and simple method. No complications, such as local infection or exposure, have occurred in any of the patients up to the present. Medial canthoplasty using the Mitek Anchor System has the advantage of being an easy technique with very accurate placement of the anchor and, consequently, reduced operating time. The operation can be performed through a small incision as well, and may not be so invasive as with other conventional procedures. This new technique of medial canthoplasty offers an excellent alternative to conventional techniques.

Adult↗
PubMed1997

Anatomic evaluation of the facial artery and vein using color Doppler ultrasonography.

Despite the importance of preoperative evaluation of small vessels in flap elevation, the conventional methods such as palpation or Doppler probes are technically insufficient. These two methods do not detect varying venous patterns that would be identified during the operation in a "trial-and-error" manner. In order to overcome this problem in the facial vessels, an anatomic study was done using color Doppler ultrasonography in 12 adults. The artery and the vein were located together at the lower border of the mandible. On the other hand, around the oral commissure, they were located apart from each other with variable distances and variable size of vein. This divergence of the facial vein from the artery is important information in the planning of axial pattern flaps. It is suggested that color Doppler ultrasonography is a useful tool for venous identification in every body region.

Adult↗
PubMed1997

Reconstruction of a short nose by full-thickness tissue transfer with osteotomy.

A severely shortened nose secondary to fracture of the middle third of the face was reconstructed by full-thickness tissue transfer with osteotomy. A nasalis musculocutaneous island flap, including the scar located in the nasal dorsum, was harvested for the lining. It was elevated based on the lateral nasal artery. The donor site defect of the flap and the covering defect were reconstructed with a forehead flap. The platform and framework of the nose were corrected with an en bloc osteotomy of the nasal bone, including the piriform aperture with a vascularized calvarial bone graft. Satisfactory and stable results were obtained in one stage along with the restoration of the relationships between the nose and the surrounding structures.

Adult↗