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Biomedical subjects

T Koyanagi

Publications and source records attributed to T Koyanagi.

At least 109 records · Page 6Linked to original sources
PubMed1997

Feasibility of urodynamic study (combined cystometry and electromyography of the external urethral sphincter) under general anesthesia in children.

BACKGROUND: To assess the feasibility of urodynamic study under general anesthesia (GA) we performed electromyography of the external urethral sphincter (EUS-EMG) on 73 children and cystometry (CM) alone on 10 children. METHODS: Subjects were divided into 3 groups. Those in groups I and II were suspected of having voiding dysfunction with (group I) or without (group II) overt neurospinal defects, while those in group III were thought to be functionally normal. EUS-EMG was performed under light anesthesia following cystourethroscopy to examine structural abnormalities. Atropine sulfate premedication was not used for the anesthetic procedure; muscle relaxants were used only for tracheal intubation. RESULTS: Voiding was observed in 83% of the patients. Among patients who voided, detrusor-external sphincter dyssynergia (DSD) was noted in 7 (38%) group I patients and 6 (19%) group II patients; in group III, voiding was synergic in all patients. In 10 cases, CM alone was carried out both under anesthesia and in the waking state; anesthesia suppressed detrusor hyperreflexia (DH) in all 9 patients but produced no change in bladder compliance. CONCLUSIONS: In children with urinary disorders, urodynamic study under GA following cystourethroscopy is a feasible method for assessing EUS function and documenting DSD; DH is not evaluable, however. Stratifying urinary management on the basis of these examinations resulted in satisfactory clinical outcomes.

Adolescent↗
PubMed1997

Idiopathic and spontaneously regressing thrombus in right renal vein and inferior vena cava.

We present the case of a 57-year-old woman with a thrombus in the right renal vein and the inferior vena cava that disappeared spontaneously during 6 months of observation. She had no thrombus-related disease such as kidney cancer, dehydration, multiple myeloma, nephrotic syndrome, or abnormal coagulability. While various examinations were being performed over a 2 month period the thrombus regressed spontaneously. After 6 months of follow-up the thrombus could not be seen on abdominal computerized tomography scan. Twenty months after disappearance of the thrombus the patient is doing well and has no recurrence of thrombus.

Abdomen↗
PubMed1997

Kidney-alone transplantation in diabetic patients with end-stage renal disease.

From January 1989 to December 1995, 5 diabetic patients with end-stage renal disease (1 woman, 4 men) underwent kidney-alone transplantation. The mean age of the recipients at the time of transplantation was 37.4 years (range, 32 to 43). Craft function and glucose tolerance was evaluated for 5 to 72 months after surgery. Postoperative complications were seen in 2 patients; nonspecific subcutaneous infections and an asymptomatic partial allograft infarction. All renal allografts were functioning 1 year after transplantation, with a mean serum creatinine level of 1.10 mg/dL (range, 0.8 to 1.8 mg/dL), and a mean urinary protein level of 17.8 mg/dL (range, 5 to 27 mg/dL). The postoperative daily dose of insulin was higher than the preoperative dose, while the level of glycated hemoglobin (HbA1C) increased after surgery and peaked 6 months after transplantation; 1 year after transplantation it had reverted to the preoperative level. As long as the diabetic complications of the renal allograft recipients are not severe, the short-term survival and the renal function of diabetic patients with end-stage renal disease improves after kidney-alone transplantation, which is still the standard method of treatment in Japan.

Adult↗
PubMed1997

An insertion or deletion in the extramembrane loop connecting helices E and F of archaerhodopsin-1 affects in vitro refolding and slows the photocycle.

Upon addition of retinal, archaeopsin-1 expressed in Escherichia coli (ecaO-1002) regenerated the chromophore in dimyristoyl phosphatidylcholine (DMPC), 3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS) and sodium dodecyl sulfate (SDS) mixed micelles as efficiently as the same opsin prepared from halobacteria. Introduction of an insertion or a deletion of five amino acids into the surface loop connecting helices E and F changed the secondary and tertiary structures of ecaO-1002 in SDS, and diminished regeneration of the chromophore. The effect of the insertion and deletion on the in vitro refolding was specific to archaeopsin because the same insertion introduced at the corresponding position of bacterioopsin (bO) did not affect chromophore regeneration. The photocycle of the regenerated ecaR-1002 decreased in DMPC/CHAPS/SDS mixed micelles compared with that of aR-1 in the claret membrane, which was consistent with the reported behavior of bO. Unexpectedly, the insertion and deletion in loop EF perturbed the photocycle of the regenerated ecaR-1002. The accumulation of long-lived N- and O-like intermediates suggested that the insertion and deletion slowed down the proton uptake steps at the cytoplasmic surface.

Amino Acid Sequence↗
PubMed1997

[Urethral opening pressure: its clinical significance in prostatic obstruction].

BACKGROUND: In the evaluation of prostatic obstruction by using the pressure-flow study (PFS), we defined intravesical pressure at initiation of voiding as urethral opening pressure. This simple parameter could reflect the degree of compressive prostatic obstruction to some extent. The aim of this study is to analyze if a correlation exsists between clinical signs and urethral opening pressure, and if they bear any prognostic value in postoperative outcome of the patients. METHODS: We analyzed 46 patients with clinical benign prostatic hypertrophy who underwent urodynamic evaluations including PFS. They were divided into 2 groups according to their urethral opening pressure. The high opening pressure was defined as greater than 70 cm water, which was noted in 24 patients (group A). Twenty-two patients had lower opening pressure (group B). Comparison of the clinical findings in these patients were reviewed. Medium-filling cystometry and PFS were performed transurethrally, by using a microtip transducer and rectal balloon. Cystoscopy was performed when possible, wherein we could examined the presence or absence of detrusor trabeculation. Transurethral prostatectomy was indicated in a total of 26 patients (16 in group A and 10 in group B), in whom postoperative clinical findings were analyzed with regard to the difference in preoperative urethral opening pressure. The patients who void with straining or who void following uninhibited detrusor contraction were excluded from this study. RESULTS: International Prostatic Symptoms Score (I-PSS) revealed no significant difference in both groups, however, patients in group A were often suffering from urge incontinence preoperatively. Significant correlation was found among the incidence of detrusor instability, detrusor trabeculation and increased opening pressure. In PFS the patients with high opening pressure tended to have higher detrusor pressure at maximum flow and greater contractile power of the detrusor in voiding. There were no difference in Qmax and residual volume both groups. Postoperatively, symptomatic improvement was significant in both groups. There was no statistical difference in postoperative I-PSS between group A and B. Although 6 patients in group A demonstrated poor urinary control at 1 month, only two patients remained incontinent at 6 months postoperatively. As to urodynamic findings, the difference in PFS were markedly reduced between both groups. No difference was noted in postoperative Qmax as well. CONCLUSION: Significant difference was found in preoperative objective findings except the flow rate between the patients with and without high urethral opening pressure, while no symptomatic difference was noted except urege incontinence in both groups. No prognostic value was demonstrated in urethral opening pressure, however, poor postoperative urinary control was often associated with initial high opening pressure in the short term. It was suggested that 1) compensatory detrusor hyperactivity improved voiding efficacy in the patients with prostatic obstruction, which was gradually normalized after the relief of obstruction, 2) symptomatic improvement was highly related to the relative improvement of the obstructive findings on PFS.

Aged↗
PubMed1997

[Clinical evaluation of donor renal artery reconstruction in kidney transplantation].

UNLABELLED: This retrospective study describes the experience of arterial reconstruction of donor kidney in our institute since 1982. MATERIALS AND METHODS: Of total 56 living related kidney transplantations 15 required renal arterial reconstruction or ligation of donor kidneys. Renal arterial reconstruction was employed for 11 cases (end to side anastomosis [4 cases], conjoined anastomosis [3], hypogastric artery graft interposition [3], other [1], while simple ligation was employed for 4. Bench surgery with microsurgical techniques was employed for the repair. Elective surgery was done for preoperatively defined multiple renal arteries [10] and aneurysm [1], while imperative surgery for intraoperatively detected accessory arteries [2] and surgical injuries [2]. Postoperative patency of arteries and renal function (GFR) and evaluated by 99mTc-DTPA renoscintigraphy. RESULTS: The mean total ischemic time of reconstructed cases was 135 min., while that of ligated ones was 67 min. None of them required hemodialysis due to acute tubular necrosis. Postoperative graft arterial patency was impaired in 2 of 11 reconstructed cases (18%), while it was impaired in 3 of 4 ligated cases (75%). Two failure attempts of arterial reconstruction cases were all imperative ones. Postoperative GFR of the graft was well preserved in all cases. CONCLUSION: We conclude that (1) Ligation and imperative surgery tend to be associated with renal infarction, although it does not affect GFR. (2) Renal artery reconstruction was highly successful in preserving renal mass (or normal cortical image), albeit longer ischemic time than simple ligation. (3) Considering importance of preserved nephron mass in clinical renal transplantation every attempt should be made to repair the donor arterial anomalies when expected (elective) or found (imperative). (4) Thorough preoperative evaluation of donor renal arteries is mandatory.

Adult↗
PubMed1997

[One-stage-bilateral adrenalectomy by thoracoabdominal approach for bilateral large pheochromocytomas in men type IIa. A case report].

We experienced a case of MEN type 2a with bilateral and large pheochromocytomas. A 39-year-old man was admitted to the previous hospital with complaints of paroxysmal headache. hypertension and diabetes mellitus. Radiographic imagings showed thyroid tumors in both lobes and bilateral adrenal tumors. Thyroid tumors were histologically proved to be medullary thyroid carcinoma by needle biopsy and systemic investigations revealed an excessive secretion of plasma and urinary cathecholamines which suggested the presence of pheochromocytoma. The patient was diagnosed as MEN type 2a. He was admitted to our hospital for the treatment of bilateral adrenal tumors for which we performed one-stage bilateral adrenalectomy by thoracoabdmonal approach. Both adrenal tumors were histologically confirmed as pheochromocytoma. The patient's postoperative course was uneventful. He underwent uneventful total thyroidectomy approximately 2 months after bilateral adrenalectomy. Even in bilateral and large pheochromocytomas, one-stage bilateral adrenarectomyenables safe postoperative managements. We concluded that the thoracoabdominal approach is feasible in the patients with huge and cranially spreading adrenal tumor, which gives us a wide operative field for easy vascular control.

Adrenal Gland Neoplasms↗
PubMed1997

Structural changes of collagen components and diminution of nerves in congenital ureteropelvic junction obstruction.

PURPOSE: Three-dimensional arrangements of smooth muscle cells, collagenous component and peripheral nerves of congenital ureteropelvic junction (UPJ) obstruction were studied in order to clarify the pathogenetic mechanism of interaction among these neuro-myo-stromal components. MATERIALS AND METHODS: The UPJ and upper ureters were obtained from 14 patients with congenital hydronephrosis (7 intrinsic and 4 extrinsic obstruction) and 7 normal controls. Three-dimensional arrangement of each structural component was observed by scanning electron microscopy, and the nerve distribution was analyzed with immunohistochemistry for protein gene product 9.5. RESULTS: The UPJ of intrinsic obstruction had structural features as follows. Muscle fascicles were sparse and thin. Each muscle cell was thin in diameter. Intercellular spaces were six to seven times wider than controls. Collagen fibrillar sheaths of smooth muscle cells (pericellular collagen fibrils attached to the basement membrane) were interwoven to form a dense felt-like structure against thin lace-like sheaths in controls. Interstitial collagenous component showed dense and compact structure against loose network of wavy collagen bundles in controls. In the muscular layer, nerve distribution was decreased to about one-third of controls. In contrast, non-stenotic portion of intrinsic UPJ obstruction as well as materials from extrinsic UPJ obstruction showed no structural difference as compared with controls. CONCLUSIONS: In the intrinsic obstruction, nerve fibers were depleted in the muscular layers in the ureteric walls, resulting in dysfunction and atrophy of muscle fibers and an increase of collagen fibers in the muscle layers with abnormal accumulation of intercellular and interstitial collagen. These changes may disrupt the mobility of UPJ and lead to both mechanical and functional obstruction.

Adult↗
PubMed1996

The proportion of free to total prostate specific antigen: a method of detecting prostate carcinoma.

BACKGROUND: Prostate specific antigen (PSA) is the most useful marker for prostate carcinoma (CaP). However, the sensitivity and specificity for PSA are not sufficient for the diagnosis of organ-confined prostate carcinoma. Recent studies have revealed that anti-PSA antibody identifies both PSA complexed to alpha-1-antichymotrypsin and free PSA, whereas anti-gamma-seminoprotein antibody recognizes free PSA exclusively. To enhance the ability of PSA to detect CaP in patients with total PSA levels of 10 ng/mL or lower, we developed the ratio of gamma-seminoprotein and PSA (free/total PSA index). METHODS: We measured free/total PSA indices for 285 patients who had serum PSA levels of 10 ng/mL or lower and who were diagnosed pathologically. RESULTS: Of the 285 patients, 228 had no prostate carcinoma (NC) and 57 had CaP. The mean total PSA level for CaP (5.137 +/- 2.483 ng/mL; mean +/- standard deviation) was significantly greater (P < 0.0001) than that for NC (3.251 +/- 2.129). The mean free/total PSA index for CaP (0.774 +/- 0.468 was significantly lower (P < 0.0001) than that for NC (1.563 +/- 0.938). The sensitivity for the free/total PSA index was similar to that for total PSA (78.9% vs. 75.4%). However, the specificity, positive predictive value, and overall accuracy for the free/total PSA index (75.9%, 45%, and 76.5%, respectively) increased by 15-20% compared with those for total PSA (56.6%, 30.3%, and 60.4%, respectively). CONCLUSIONS: The free/total PSA index improved the specificity of PSA without impairing the sensitivity in detecting CaP among patients with serum PSA levels of 10 ng/mL or lower.

Humans↗
PubMed1996

To what extent does a given heart rate correlate with following heart rates in the developing human fetus?

To quantitatively determine the extent to which a given heart rate correlates with the following heart rate(s) at any gestational age, we studied 181 uncomplicated human fetuses between 23 and 41 weeks gestation. A continuous 90-120 min observation was made for each case using external Doppler-ultrasound cardiotocography. For every individual fetal heart rate dataset, 'probability distribution matrices' were calculated with fetal heart rates (termed FHRs) at 1-beat/min (bpm) intervals, and the beat-to-beat(s) difference (termed DFHRn: 1 < or = n < or = 1000), also at 1-bpm intervals arranged in rows and columns, respectively, with probability in each element. Using 'piecewise linear regression', (1) the difference between the DFHR1 (n = 1) probability distribution matrix as the 'control' and a given DFHRn (n > or = 2) probability matrix as the 'variable', was analyzed to obtain the statistically critical point(s) (termed 'beat-delay' in beats) for each fetus, and (2) a scattergram of 'beat-delay' vs. gestational age-group, made from all fetuses studied, was analyzed to reveal any critical age(s) in gestation. One statistically significant point was evident at 28-29 weeks gestation. During the period prior to the critical point, a linear decrement in 'beat-delay' with 21 beats (mean) at 23-25 weeks to 11 beats at 28-29 weeks gestation was noted, suggesting that the conduction system-oriented heart beat gradually comes under functional control of the autonomic nervous system as well as under possible regulation by the maturating medulla oblongata. From the critical point, through to term, there was no significant change in 'beat-delay' ranging from 7-11 beats, thereby implying that the fetal heart rate becomes stabilized as a result of the control rendered by the more developed autonomic nervous system function. Whether or not brain function cephalad to the medulla oblongata actually participates in this phenomenon remains to be elucidated.

Embryonic and Fetal Development↗
PubMed1996

DNA typing of HLA class II genes in Japanese patients with rheumatic heart disease.

To study further the association between HLA and rheumatic valvular disease, DNA typing HLA class II genes (DRB1, DQA1, DQB1 and DPB1) was performed in 72 unrelated Japanese patients with predominant mitral stenosis and 525 unrelated Japanese healthy controls, based on the polymerase chain reaction in combination of dot-blot hybridization with sequence-specific oligonucleotide probes. As compared with controls. Patients with mitral stenosis showed increased frequencies of DQA1*0104 (18.1% v 7.2%; RR = 2.82, P = 0.002, Pc = 0.03) and DQB1*05031 (13.9% v 4.8%: RR = 3.23, P = 0.002, Pc = 0.05). In contrast, no significant deviation in the frequencies of DRB1, DPA1 or DPB1 alleles was observed in the patients. These observations suggest that the susceptibility to mitral stenosis is in part controlled by a gene (or genes) in close linkage disequilibrium with HLA-DQA1*0104 and DQB1*05031, i.e. the susceptibility gene may be mapped within the HLA-DQ region.

Adult↗
PubMed1996

Comparison of clinical outcomes of coronary artery bypass grafting and percutaneous transluminal coronary angioplasty in renal dialysis patients.

BACKGROUND: The leading cause of death in chronic renal dialysis patients is cardiovascular disease. As the number of dialysis patients increases, we are encountering more patients with severe ischemic heart disease requiring coronary intervention. METHODS: A retrospective analysis was performed of the short- and long-term clinical results in 23 coronary artery bypass grafting patients and 20 coronary angioplasty patients undergoing chronic renal dialysis. RESULTS: Among coronary bypass grafting patients, there were no hospital deaths. The graft patency rate was 100% for arterial grafts. There were four late deaths and four cardiac events. In coronary angioplasty patients, the lesion success rate was 76%. There were no hospital deaths and three major complications. The restenosis rate was 70%. There were two late deaths and 14 cardiac events. The 5-year cardiac event-free rate was 70% in coronary bypass grafting patients, significantly better than 18% in coronary angioplasty patients (p < 0.001). CONCLUSIONS: Coronary artery bypass grafting in chronic renal dialysis patients can be accomplished with a better short- and long-term outcome than coronary angioplasty, through an intensive perioperative dialysis program and extensive use of arterial grafts.

Angioplasty, Balloon, Coronary↗
PubMed1996

Infective endocarditis caused by Campylobacter fetus after allogeneic tooth transplantation: a case report.

A patient developed infective endocarditis caused by Campylobacter fetus. He gave a history of recent dental extraction and allogeneic tooth transplantation. He was treated with various antibodies to which the organism was said to be sensitive, but it was not until the transplanted tooth was removed that he started to improve. The mode of infection was thought to be blood borne through the open tooth socket from the raw chicken that he ate regularly.

Animals↗
PubMed1996

Clinical manifestations of hypertrophic cardiomyopathy with mutations in the cardiac beta-myosin heavy chain gene or cardiac troponin T gene.

Introduction of molecular genetics has improved our understanding of HCM substantially, but has simultaneously raised further important questions. Studies on HCM are revealing a more complex picture than might have been expected on clinical grounds. Further extensive studies are warranted to elucidate the pathogenesis and pathophysiology of HCM, and to establish therapeutic strategies to cure or prevent the development of the disease.

Adult↗
PubMed1996

Parturition in six renal allograft recipients.

Between 1983 and 1994, we studied renal function and neonatal conditions for eight pregnancies and births to six women who had received renal transplants in order to assess the effect of an allograft on pregnancy and its outcome. The gestation period was 34 to 39 weeks (mean 36 weeks and 4 days), and four pregnancies ended before term. All eight babies were delivered by cesarean section. Intrauterine growth retardation (IUGR) was found in both babies of one woman who had been treated with conventional (without cyclosporin) immunosuppression. The serum creatinine level did not change during gestation in any of the women but was elevated after delivery in four. Four mothers suffered from proteinuria (25-364 mg/dl) during gestation, but the proteinuria disappeared after delivery in all but one case. The one exception, persistent proteinuria of 100-200 mg/dl, was assumed to result from the recurrence of the original renal disease (lgA nephropathy). The reduction of creatinine clearance and hydronephrosis of one graft noted during gestation were later reversed. None of the eight babies (four females and four males) was congenitally malformed, and their Apar scores were 6 to 9 (median 8). They are now 3 months to 11 years old, and seven of them are healthy and show good growth. One of the two IUGR babies has not grown well; her weight and height are more than 1 SD below the mean for her age, and she is mentally retarded and suffers from muscle weakness. Compared with dialysis patients, female renal allograft recipient have a better quality of life because they can safely deliver a child if they observe the criteria for pregnancy established for renal allogaft recipients.

Child↗