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Biomedical subjects

M Gotoh

Publications and source records attributed to M Gotoh.

At least 379 records · Page 21Linked to original sources
PubMed1989

Denervation supersensitivity of the rabbit urinary bladder to calcium ion.

We investigated in vitro the supersensitivity of denervated rabbit bladder to Ca2+. Seven days after denervation achieved by bilateral sacral rhizotomy, the capacity of the denervated bladder increased by 2.2 times as compared with the control (126.3 to 277.3 ml.), and wet weight also increased 4.3 times (3.6 to 15.3 gm.). After 30 minutes incubation in normal Krebs' solution the denervated bladder strips showed significantly increased amplitude of contractions to the cumulative acetylcholine addition than the control. After incubation in normal Krebs' solution for 30 minutes, muscle strips were washed three times with Ca-free Krebs' solution and incubated 30 minutes in this solution. Cumulative Ca2+ replenishment (0.5 to 10 mM) induced dose-dependent contractions of the detrusor muscle strips in Ca2+-free Krebs' solution, where the contractions were significantly stronger in the denervated detrusor muscle than in controls. Pretreatment with 10(-6) M verapamil (Ca-entry blocker) eliminated the enhanced Ca2+-induced contractions of the denervated detrusor strips, while 10(-6) M procaine (Ca-induced Ca releasing blocker) only partially inhibited them. After depolarizing the cell membrane with 40 mM KCl, the Ca2+-induced contractions of the control strips were markedly enhanced but those of the denervated strips were not. These results demonstrate the supersensitivity of the denervated detrusor muscle to Ca2+. We conclude that hyperpermeability of the cell membrane to Ca2+ influx through calcium channels is responsible for supersensitivity of the denervated detrusor muscle to Ca2+.

Acetylcholine↗
PubMed1989

Quantifying thread tension is of clinical use in Stamey bladder neck suspension: analysis of clinical parameters.

Tension on the nylon loops in a Stamey endoscopic bladder neck suspension has been quantified for the first time by using a spring scale. Clinical data were compared between 14 patients with undetermined tension (control group) and 57 with tension of either 400, 600, 700, 800 or 1,000 gm. Experimental study during the operation demonstrated that changes in the posterior urethrovesical angle and distance that the bladder neck was elevated were not proportional to the tension: the lower the thread tension the larger the change in these 2 parameters. Compared to the control group a significant decrease in the period of suprapubic drainage was observed in patients with quantified tension. Operative success was obtained in 86 per cent of the control group and 91 per cent of those in whom tension was quantified. A tension of 400 to 600 gm. seemed to be most appropriate for a successful outcome. We conclude that quantifying the thread tension is useful to prevent either over-tightness of the nylon loops or insufficient suspension of the bladder neck, and that with a spring scale it is easy to instruct a beginner on how tightly to tie the threads.

Adult↗
PubMed1989

Immunological unresponsiveness to hepatic allografts in rats. Immunological reactivities of the recipient to donor antigens.

Wistar (RT1bv1) rats transplanted orthotopically with ACI (RT1a) livers survive indefinitely without any immunosuppression, while heterotopic heart grafts or skin grafts are rejected acutely in this combination. Levels of alkaline phosphatase after liver allografting remain significantly higher than those found in controls receiving syngeneic grafts. We studied changes in immune responsiveness in rats receiving liver grafts. Local graft-versus-host reactivity was present at all times assayed. Delayed type hypersensitivity reactions were already positive 2 weeks after liver transplantation and increased in strength. Liver graft-bearing rats were subsequently grafted with donor or third-party skin. Third-party skin grafts survived significantly longer on liver-grafted rats than on untreated controls when grafted within the first week after grafting. Donor-type skin grafts survived longer than controls when grafted within the first 4 weeks after liver grafting, although the skin grafts were eventually rejected. Donor-type skin grafted more than 8 weeks after liver grafting was rejected acutely. In an adoptive transfer assay, ACI hearts survived significantly longer in Wistar rats given serum from Wistar donors 2-4 weeks after ACI liver grafts than in untreated controls. On the other hand, spleen cells obtained at any period after liver grafting were not capable of prolonging cardiac allograft survival after transfer to syngeneic recipients. Thus cellular responses to ACI antigen are not changed during the life-span of liver-grafted animals. Evidence suggests that a serum "enhancing" factor protects the donor liver from rejection in the initial period after liver transplantation. The long-term acceptance of liver grafts is discussed.

Animals↗
PubMed1989

A unique verrucous anogenital tumor associated with type 6b-related human papillomavirus.

Multiple dark brown papillomatous tumors, showing some histological features of verrucous carcinoma or giant condyloma, developed mainly in the anogenital region of a Japanese woman. The tumors first appeared when she was 51 years old and annoyed her for over 20 years with several recurrences without any frank malignant transformation, after surgery. Immunohistochemically, papillomavirus genus-specific antigen was demonstrated only in small foci of the lesions resected at first operation. Southern blot analysis revealed human papillomavirus type 6b-related DNA in a surgically resected specimen. The possible role of the human papillomavirus in the genesis of this unique tumor is discussed.

Aged↗
PubMed1989

The relative importance of nervous system and hormones to the 2-deoxy-D-glucose-induced hyperglycemia in fed rats.

We examined the relative contributions of hormones and nervous system to the total 2-deoxy-D-glucose (2-DG)-induced central nervous system-mediated hyperglycemia. 2-DG was injected into the third cerebral ventricle in the following four groups of rats, and hepatic venous plasma glucose, immunoreactive glucagon, immunoreactive insulin, epinephrine, and norepinephrine were measured: 1) intact rats; 2) intact rats receiving somatostatin with insulin infusion through the femoral vein to inhibit glucagon secretion and maintain the basal insulin level; 3) bilateral adrenalectomized (ADX) rats to prevent epinephrine secretion; and 4) ADX rats receiving somatostatin with insulin infusion. Comparing areas under glucose curves among the intact rats, those receiving somatostatin with insulin infusion, ADX rats, and ADX rats receiving somatostatin with insulin infusion, the area under the glucose curve was intact rats greater than intact rats receiving somatostatin with insulin infusion greater than ADX rats receiving somatostatin with insulin infusion greater than ADX rats. These results suggest that there are three distinct sympathetic nervous system responses to 2-DG-induced central nervous system-mediated hyperglycemia. 2-DG-induced hyperglycemia is not dependent on only one of those three systems, it is dependent on all of them. The relative potency of the factors to 2-DG-induced hyperglycemia increases in the following order: direct neural innervation of liver (including suppressive epinephrine action on insulin secretion), glucagon, and direct epinephrine action on liver.

Adrenalectomy↗
PubMed1989

Central nervous system-mediated glucagon secretion is enhanced by alpha 2-adrenoreceptor activation.

We assessed the response of the adrenergic receptor in pancreatic glucagon secretion to central nervous system stimulation. Injection of neostigmine (5 x 10(-8) mol) into the third cerebral ventricle in intact rats resulted in increased epinephrine and norepinephrine secretion associated with glucagon secretion. This glucagon secretion was still observed in bilateral adrenalectomized (ADX) rats, although its concentration was significantly lower than that in the intact rats. This glucagon rise was significantly inhibited by ip treatment of ganglionic blocker with hexamethonium. Intraperitoneal injection of alpha-adrenergic receptor antagonist phentolamine (5 x 10(-7) mol), but not of beta-adrenergic receptor antagonist propranolol (1 x 10(-6) mol), reduced the hyperglucagonemic effect of a subsequent neostigmine injection in intact and ADX rats, although these antagonists did not influence epinephrine or norepinephrine secretion in intact rats. In addition, ip injection of the selective alpha 2-receptor antagonist yohimbine (5 x 10(-7) mol), but not of the selective alpha 1-receptor antagonist prazosin (1 x 10(-6) mol), inhibited the neostigmine-induced glucagon secretion in intact and ADX rats. From this evidence it is suggested that central nervous system-mediated glucagon release is enhanced by alpha 2-adrenoreceptor stimulation by either catecholamines or the autonomic nervous system.

Adrenalectomy↗
PubMed1989

[A study on the role of the dispersion of repolarization in the induction of ventricular fibrillation using the suction electrode technique].

The arrhythmogenic role of increased dispersion of repolarization (Dispersion) in monophasic action potentials (MAPs) was studied in 12 open-chest dogs. Following exposure of the heart by pericardial cradle, four MAPs were recorded simultaneously from the right and left ventricular surfaces using the suction electrode technique. Maximum dispersion (maxDIS) was defined as the greatest Dispersion between any two of the four MAPs in atrial pacing and ventricular premature stimulation (VPS). Dispersion was increased by warming the heart with a heat lamp and regional cooling with a cold saline (2-4 degrees C) drip. In control experiments maxDIS in atrial pacing (PCL: 500 ms) was 21 +/- 10 ms. MaxDIS was increased when the VPS was applied at the right ventricular apex (RVa) (maxDIS: 73 +/- 17 ms), at the left ventricular base (LVb) (maxDIS: 78 +/- 34 ms), and at the left ventricular apex (LVa) (maxDIS: 89 +/- 20 ms). Ventricular fibrillation, however was not induced by any VPSs. Warming the heart and regional cooling increased Dispersion from the control value to 180 +/- 58 ms (p less than 0.001), mainly because of the increased MAP duration difference (delta MAPD) in atrial pacing, but no ventricular fibrillation occurred spontaneously. VPS applied at the LVa induced ventricular fibrillation following marked increase of maxDIS, which was due to added contributions of delta MAPD and the maximal difference between activation times (delta AT). With RVb cooling ventricular fibrillation was induced in 16/20 cases (80%) (maxDIS: 286 +/- 124 ms), with RVa cooling in 6/9 cases (67%) (maxDIS: 263 +/- 109 ms), and with LVb cooling in 11/23 cases (48%) (maxDIS: 172 +/- 67 ms). There was significant linear correlation between maxDIS and delta AT (r = 0.88, p less than 0.01), and also delta MAPD (r = 0.80, p less than 0.01). We conclude that the increased Dispersion plays an important role in the induction of ventricular fibrillation. This temperature gradient model is a favorable tool to study the role of Dispersion as one of the important factors which induce ventricular fibrillation.

Action Potentials↗
PubMed1989

In situ hybridization and immunohistochemical study of human papillomavirus infection in adult laryngeal papillomas.

Routinely processed paraffin sections from 20 patients with adult laryngeal papillomas were examined for the presence of human papillomavirus type 11 (HPV-11) DNA and its specific mRNA by in situ hybridization methods using 35S-labeled RNA probes. Immunohistochemical techniques were also used to identify papillomavirus genus-specific common antigen (pgs-antigen). HPV-11 DNA signals and/or papillomavirus genus-specific common antigen were detected in all eight samples of multiple laryngeal papilloma. On the other hand, in 12 samples of single laryngeal papilloma, neither papillomavirus genus-specific common antigen nor HPV-11 DNA were detected. Four patients were positive for both HPV-11 DNA and pgs-antigen. In three of these four patients, HPV-11 mRNA signals were also detected. These results provided direct evidence of the association of HPV and adult multiple laryngeal papilloma.

Adult↗
PubMed1989

Effect of gamma-irradiation on mouse pancreatic islet-allograft survival.

Elimination or inactivation of lymphoid tissue in the pancreatic islet preparation achieves prolongation of islet-allograft survival. In this study we examined the effect of gamma-irradiation on mouse islet-allograft survival. In a B6AF1 isograft model, irradiation up to 2400 rad did not induce deterioration of islet function over 200 days, but greater doses caused cessation of graft function between 83 and 186 days. When DBA/2 crude islets were transplanted into B6AF1 recipients, all nonirradiated allografts were acutely rejected. Marked prolongation of allograft survival was achieved by islet irradiation with doses between 800 and 12,000 rad. With higher doses, significant numbers of allografts survived beyond the controls, but many lost function between 78 and 180 days, with none surviving greater than 200 days. Irradiation with 16,000 rad caused acute radiation damage. Because most secondary islet allografts in recipient mice that lost primary islet-graft function between 84 and 195 days survived greater than 100 days, late functional loss was probably due to the radiation injury. Combined use of recipient treatment with cyclosporin A and graft irradiation (2400 rad) achieved prolongation of DBA/2 islets in B6AF1 mice.

Animals↗
PubMed1989

Insulin and glucagon secretion after pancreatectomies. Correlation of secretion and hormonal contents of remaining pancreas.

We studied whether insulin and glucagon secretory capacities change in relation to the corresponding hormonal contents in the pancreas remnant after pancreas resection. The following groups of dogs were used: sham operated (S-O), left pancreatectomized (L-Px), right pancreatectomized (R-Px), subtotal pancreatectomized (St-Px), and total pancreatectomized (T-Px). Endocrine functions were assessed by intravenous glucose tolerance test (IVGTT) and insulin tolerance test (ITT) in each dog under anesthesia before surgery and 1 wk after. In these five groups, the insulin secretory capacities, assessed as the integrated incremental secretion of immunoreactive insulin (sigma delta IRI) from the IVGTT, decreased to 95 +/- 11, 78 +/- 9, 48 +/- 8, 12 +/- 8, and -4 +/- 4% of the respective preoperative values, and these values were proportional to the percentage residual weight (100, 64 +/- 2, 35 +/- 2, 13 +/- 2, 0%) and IRI content (100, 59 +/- 4, 45 +/- 3, 10 +/- 2, 0%) of the pancreas remnant. After surgery, glucagon secretory capacity, the integrated incremental secretion of immunoreactive glucagon (sigma delta IRG) during the ITT, decreased significantly in the L-Px, St-Px, and T-Px groups but not in the R-Px group. The sigma delta IRG values as percentages of the preoperative values were 109 +/- 25, 46 +/- 11, 89 +/- 13, 19 +/- 11, and 3 +/- 3%, respectively, for the five groups. These values were proportional to the percentage residual IRG contents of the pancreas remnants (100, 48 +/- 6, 65 +/- 8, 12 +/- 2, 0%) rather than to the percentage residual pancreatic weights.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Clinical study of a modified Stamey's endoscopic bladder neck suspension procedure for one hundred female patients with stress incontinence].

One hundred female patients with stress incontinence have been operated on by means of modified stamey's endoscopic bladder neck suspension procedure, i.e. quantifying the thread tension for bladder neck suspension. Twelve patients had 1,000 grams in the nylon loop, 5,800 grams, 9,700 grams, 25,600 grams and 49,400 grams. A follow-up period varied from 10 to 32 months (mean: 20.5 months). A 60-min pad-weighing test revealed urinary loss of 1.0 to 196.0 grams/hour (mean: 36.0) prior to operation. 1. The modified Stamey's procedure was successful in 95 patients (95%). The appropriate thread tension for bladder neck suspension was 400 grams. 2. Various complications were encountered: removal of unilateral nylon suture was necessitated in 2 patients, bleeding from operative wound in 2, bladder tamponade in 2, and clean intermittent catheterization for more than one month in 4. 3. Micturition parameters, i.e. maximum and average flow rates, temporarily got worse post-operatively. Maximum urethral closure pressure decreased and functional profile length elongated which were significantly different from those of pre-operative values. 4. Questionnaire sent to the patients revealed that 89 percent of them were satisfied with the operative results but 11 percent were not. 5. The modified Stamey's procedure is simple to perform and prevents over-tightness of nylon loops. We conclude that this operative method is the treatment of choice for correction of stress incontinence.

Adult↗
PubMed1989

[Continent vesicocutaneostomy. Preliminary experiments on dogs].

A new operative technique for continent urinary diversion was designed as a continent vesicocutaneostomy and preliminary experiments were performed on 7 dogs. A U-shaped flap of anterior bladder wall (30 X 20 X 30 mm) was created, which was then rolled and sutured to an efferent duct. One-half to two-thirds in length of the efferent duct was placed between the muscular layer and mucosa of the bladder, and the distal end of the efferent duct was anastomosed to the cutaneous stoma made at the suprapubic area. In this urinary diversion, excretion of urine from the bladder was done by intermittent catheterization from the stoma through the efferent duct. The operation was successful on all of the experimented dogs, continence of the stoma was preserved and catheterization through the stoma was achieved easily. Urodynamic assessment of the efferent duct was performed, being focused on the mechanism of continence, at 3 and 6 months after the operation. The length of continence zone and maximum closing pressure through the entire efferent duct were 23.2 +/- 4.5 mm and 41.2 +/- 14.7 cmH2O respectively with empty bladder (intravesical pressure = 0). When the bladder was full (intravesical pressure = 20-40 cmH2O), these parameters were 21.4 +/- 4.7 mm and 36.0 +/- 7.0 cmH2O respectively. The length of continence zone and maximum closing pressure of only the submucosal part of the efferent duct were 12.8 +/- 4.3 mm and 18.5 +/- 5.2 cmH2O with empty bladder, 13.3 +/- 2.9 mm and 22.0 +/- 9.9 cmH2O with full bladder.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Use of microcrystalline collagen powder and fibrinogen tissue adhesive for hemostasis and prevention of rebleeding in patients with hepatocellular carcinoma associated with cirrhosis of the liver.

Partial resection of the liver is the only curative treatment for patients with hepatocellular carcinoma associated with severe cirrhosis of the liver. Surgical hemostasis on the cut surface of the cirrhotic liver appears very difficult because of the resultant deep cavity and the marked hemorrhagic diathesis. However, by using the microcrystalline collagen powder and the fibrinogen tissue adhesive, complete hemostasis and prevention of postoperative bleeding can be obtained, with minimal blood loss and hepatic ischemia.

Aprotinin↗
PubMed1989

Lymphocyte subsets in pulmonary venous and arterial blood of lung cancer patients.

Lymphocyte subsets in pulmonary venous blood (PVB) smears from 42 patients with lung cancer were immunocytochemically determined. In four patients, pulmonary arterial blood (PAB) smears were also studied for comparison with PVB. Seven healthy donor peripheral blood (PB) smears were used as controls. The percentage of T cells, helper/inducer T (Th) cells and B cells were significantly lower (P less than 0.01) than in normal controls but those of suppressor/cytotoxic T (Ts) cells, natural killer (NK) cells (P less than 0.01) and S100+ small lymphoid cells (P less than 0.05) were higher. This resulted in a decrease in the Th:Ts value in cancer patients (1.46 vs. 2.28 for normal controls; P less than 0.01). The Th and Ts value of PVB from patients in pathological Stages III and IV was lower than from those in Stages I and II because of the increase in Ts cells in the former (P less than 0.05). S100+ small lymphoid cells were increased in cancer patients, especially in those with adenocarcinoma. The present study demonstrates immunoregulation abnormalities in cancer bearing hosts, the results correlating well with the stage of the cancer. Determining lymphocyte subset alterations in PVB did not, however, enable us to detect the changes associated with local immune responses against cancer.

Adult↗