Biomedical subjects

Shinya Kobayashi

Publications and source records attributed to Shinya Kobayashi.

26 records · Page 2Linked to original sources

PubMed2003

Kupffer-cell depletion attenuates colonic and extracolonic granulomatous inflammation in chronic colitis.

Intramural injection of peptidoglycan-polysaccharide polymers into the distal colon in rats induces granulomatous colitis associated with extracolonic manifestations. We sought to clarify the effects of Kupffer-cell depletion induced by the intravenous administration of gadolinium on colonic and extracolonic inflammation in this model. The effects of Kupffer-cell depletion on acute and chronic inflammation were evaluated 3 days and 3 weeks after injection of peptidoglycan-polysaccharide, respectively. We assessed the effects of gadolinium on colonic cytokine levels in vivo and the viability of elicited peritoneal macrophages and peptidoglycan-polysaccharide-induced production of nitrite, an indirect index of nitric oxide production, by these cells in vitro. A single injection of gadolinium caused a marked decrease in the number of Kupffer cells stained with antibodies within 3 days. Gadolinium treatment did not alter acute inflammation at 3 days. Repeated treatment with gadolinium dramatically attenuated grossly observed chronic inflammation, including thickening of colon wall, hepatic and splenic nodules, and swelling of foot joints; and significantly reduced the proportional areas occupied by granulomas in the colon, liver, and spleen at 3 weeks. These protective effects were reflected in significant reduction in colon and liver weights; gross scores; colonic myeloperoxidase activity, an indirect quantitative index of granulocyte infiltration; colonic interleukin-1beta levels; plasma nitrite and nitrate levels; and decreased tendency toward arthritis. Although gadolinium did not cause injury in elicited peritoneal macrophages in vitro, the compound dose-dependently attenuated peptidoglycan-polysaccharide-induced production of nitrite by these cells. Chronic Kupffer-cell depletion attenuates peptidoglycan-polysaccharide-induced granulomatous inflammation in the colon, liver, and spleen and reduces the incidence of arthritis, possibly by suppressing the production of interleukin-1beta and nitric oxide.

Animals↗

PubMed2003

Experience with flexible video cystoscope equipped with built-in high-frequency cauterizing element for transurethral resection of the bladder.

We successfully treated three patients using the flexible video cystoscope (CYF-240A, Olympus, Japan) for superficial bladder cancer under local anesthesia and/or spinal anesthesia. The major advantage of this new technique is that surgeons can use digital pictures and high frequency cauterization. This new system provides good quality of life for bladder cancer patients experiencing frequent recurrences.

Aged↗

PubMed2003

Urodynamic effects of alpha1-blocker tamsulosin on voiding dysfunction in patients with neurogenic bladder.

BACKGROUND: The therapeutic role of alpha-blockers in the treatment of voiding disorders due to benign prostatic hyperplasia has been extensively examined. To investigate a possible effect of alpha1-blocker on urodynamic voiding parameters in patients with neurogenic bladder, we conducted a clinical trial using tamsulosin. METHODS: Twenty-four patients (14 men and 10 women) ranging from 24 to 82 years of age (mean age 61 years) with neurogenic bladder were analyzed. Urodynamic studies were performed before and after treatment with 0.4 mg tamsulosin daily for 4 weeks. RESULTS: On uroflowmetry, the average flow rate (from 4.6 +/- 3.3 to 6.7 +/- 3.0 mL/s, P = 0.04), maximum flow rate (from 9.4 +/- 6.8 to 14.1 +/- 7.0 mL/s, P = 0.016) and residual urine rate (from 46 +/- 29 to 32 +/- 21%, P = 0.02) improved significantly. In patients with detrusor contraction during voiding, detrusor opening pressure and detrusor pressure at maximum flow decreased significantly from 69.0 +/- 36.2 to 49.2 +/- 26.4 cmH2O (P = 0.046) and from 66.7 +/- 34.6 to 53.6 +/- 26.5 cmH2O (P = 0.007), respectively. On the other hand, in patients with detrusor areflexia, vesical opening pressure (from 78.2 +/- 23.4 to 61.6 +/- 25.2 cmH2O), or vesical pressure at maximum flow (from 68.6 +/- 23.2 to 62.9 +/- 25.2 cmH2O) did not change significantly after treatment. CONCLUSION: Tamsulosin reduces functional urethral resistance during voiding and improves flow rate in patients with neurogenic bladder. It has more beneficial urodynamic effects in patients with detrusor contraction during voiding than in patients with detrusor areflexia.

Adrenergic alpha-Antagonists↗

PubMed2003

Using MR imaging to predict invasion of the recurrent laryngeal nerve by thyroid carcinoma.

OBJECTIVE: We evaluated the accuracy of MR imaging findings for predicting invasion of the recurrent laryngeal nerve by thyroid carcinoma and established an optimal criterion on which to base this prediction. MATERIALS AND METHODS: We reviewed MR imaging findings (lesion size and posterior extension of tumor; encirclement of and invasion into the laryngeal cartilage, trachea, and esophagus by the tumor; and the amount of effaced fatty tissue in the tracheoesophageal groove or between the laryngeal cartilage and hypopharyngeal wall) in 66 patients with thyroid carcinoma. The amount of effaced fatty tissue was classified as one of five grades: 1, normal amount of fatty tissue; 2, partly effaced; 3, completely effaced in one MR imaging slice; 4, completely effaced in two contiguous MR slices; and 5, completely effaced in three or more contiguous MR slices. RESULTS: Thirty-two (48%) of the 66 patients had surgically or pathologically verified recurrent laryngeal nerve invasion. Logistic modeling revealed that the amount of effaced fatty tissue (p < 0.001) and the lesion size (p = 0.033) were the significant factors. Using the threshold values for the lesion size to predict invasion, we found that a threshold of more than 2.9 cm showed the highest accuracy, 76%, with 78% sensitivity and 74% specificity. For the amount of effaced fatty tissue, a grade of 3 or more had the highest accuracy, 88%, with 94% sensitivity and 82% specificity. Addition of the lesion size to this criterion did not improve the diagnostic accuracy of using the amount of effaced fatty tissue alone. CONCLUSION: Invasion of the recurrent laryngeal nerve by thyroid carcinoma was accurately predicted by the finding of effaced fatty tissue on MR imaging.

Adult↗

PubMed2002

Are neuroendocrine cells responsible for the development of benign prostatic hyperplasia?

OBJECTIVES: To examine the possible relationship between the distribution of neuroendocrine (NE) cells and the development of benign prostatic hyperplasia (BPH) in the human prostate, we performed an NE cells-distribution analysis and made morphological observations of acinous structures in different-aged prostates. METHODS: Forty-three human prostates obtained from surgical and autopsy cases aged from 2 months to 86 years were examined immunohistochemically using Chromogranin A and analyzed with special reference to the development of BPH. RESULTS: NE cells were distributed predominantly in the verumontanum and main prostatic ducts and were fewer in number in the terminal acini. As BPH development progressed, the NE cells were greatly diminished in number or completely lost from most adenoma nodules. CONCLUSIONS: The NE cells of the prostate may be distributed and transported from the periurethral region near the verumontanum to the terminal acini during the development of the acinar structures. The distribution pattern is relatively consistent among prostates of all ages. However, NE cells do not appear in acquired tissue within BPH nodules as the nodules develop. Thus, the distribution of NE cells does not seem to be related to the development of BPH.

Adolescent↗

PubMed2002

Fate of tetraplegic patients managed by ileal conduit for urinary control: long-term follow-up.

BACKGROUND: A study was conducted to evaluate our experience of ileal-conduit formation in tetraplegic patients with special reference to late complications due to upper urinary tract stones and pyocystis. METHODS: Ileal-conduit formation was performed in 16 patients with tetraplegia to improve urinary management. The mean age at operation was 46 years (range 19-70) and the mean follow-up period was 8.7 years (range 2-17). We evaluated the results retrospectively from patients' medical records. RESULTS: Two patients died 2 years after the procedure and one patient died 8 years after the ileal-conduit formation. Five patients suffered from repeated renal or ureteral stone. In three of these cases, serious urinary tract infections developed whenever the stone caused an obstruction. Three patients received a cystectomy at the time of the ileal-conduit formation. Eight patients suffered from empyema of the bladder and in two of these cases a subsequent cystectomy was required. CONCLUSIONS: Ileal-conduit formation should be cautiously considered as an option in the urinary management of tetraplegic patients, particularly when more conservative management strategies have proved unsuccessful. However, an antirefluxing mechanism for the ileal conduit may be necessary, and a simultaneous cystectomy may improve the results.

Adult↗

PubMed2002

Quantification of cardiac stress during EGD without sedation.

BACKGROUND: Although the complication rate of endoscopy is low, EGD may induce cardiac stress. The aim of this study was to quantify cardiac stress during EGD. METHODS: Heart rate, blood pressure, cardiac output, and peripheral oxygen saturation were measured during endoscopy without sedation in 7 volunteers. Cardiac output was measured with an automated echocardiographic technique. Cardiac index, left ventricular work index, and rate-pressure product were calculated. Serum catecholamine concentrations were measured before and after the examination. RESULTS: Heart rate increased significantly when the endoscope was located in the esophagus compared with the rate before insertion (p < 0.05). No significant changes in cardiac index and left ventricular work index were observed during endoscopy. Rate-pressure product increased significantly at the point of esophageal observation compared with that before insertion (p < 0.05). The rate-pressure product was maximally increased during esophageal observation at 66% over baseline (95% CI [45%, 86%]). Serum concentration of norepinephrine rose significantly after the examination (p < 0.05). CONCLUSIONS: Cardiac output did not increase during EGD without sedation in healthy male volunteers. Cardiac stress increased during EGD as indicated by a 66% increase in rate-pressure product. The cardiac stress was approximately equal to that observed in 3.3 to 5 metabolic equivalents of treadmill exercises.

Adult↗

PubMed2002

[Iatrogenic ureteral injury and the development of vesico-vaginal fistula: a complication of total hysterectomy for multiple myoma uteri].

A 42-year-old woman underwent total hysterectomy for multiple myoma uteri. Postoperatively the patient complained of lower abdominal pain and total incontinence. She had also developed left-sided hydronephrosis. Left nephrostomy was constructed and necessary investigations were done. It was diagnosed as a case of left ureteral injury with vesico-vaginal fistula. Repair of vesico-vaginal fistula and reimplantation of the left ureter were performed in a single setting three months after the injury. Subsequently, the nephrostomy was removed. Hydronephrosis was improved with an excellent outcome of fistula repair.

Abdominal Pain↗