Biomedical subjects

K Honda

Publications and source records attributed to K Honda.

At least 271 records · Page 15Linked to original sources

PubMed1997

Thrombotic microangiopathy associated with alpha-interferon therapy for chronic myelocytic leukemia.

A 31-year-old man diagnosed as having chronic myelocytic leukemia (CML) developed renal insufficiency with nephrotic-range proteinuria during alpha-interferon (IFN) therapy for CML. A renal biopsy specimen showed remarkable thrombotic microangiopathic lesions resembling those of hemolytic-uremic syndrome. The patient had papules on both lower legs, and a cutaneous biopsy showed similar microangiopathic lesions in dermal and subcutaneous vessels. Although discontinuation of IFN and initiation of prednisolone therapy resulted in resolution of proteinuria, renal insufficiency persisted. These findings suggest that long-term IFN therapy can induce late-onset thrombotic microangiopathy in systemic microvessels.

Adult↗

PubMed1997

Changes of behavior and monoamine metabolites in the rat brain after repeated methamphetamine administration: effects of duration of repeated administration.

1. The authors studied the mechanism of the reverse-tolerance phenomenon caused by long-term administration of central stimulant drugs. Methamphetamine(MAP) was chronically administered to rats, and the reverse-tolerance phenomenon was studied in terms of behavioral changes and changes in monoamine metabolites, the latter being examined by in vivo microdialysis of the extracellular compartment of the corpus-striatum. The authors also studied [3H]SCH23390 and [3H]spiperone binding to striatal membranes after chronic MAP administration. 2. MAP(4 mg/kg) or saline was administered intraperitoneally once daily to male rats. In Groups 1 and 2, 10 and 30 injections of MAP were given, respectively. In Groups 3 and 4, animals received 10 and 30 injections of saline as controls. One week after the final injection, all rats were challenged with 4 mg/kg MAP. 3. Groups 1 and 2 displayed more intense stereotypy than Groups 3 and 4, indicating that behavioral sensitization had been achieved in the former. Dopamine(DA) levels increased rapidly in response to MAP challenge in all groups, with the increases in Groups 1 and 2 being more marked than that in Groups 3 and 4. Group 1 showed greater persistence and a higher rate of DA increase than Group 2. 4. The number of D1 and D2 dopamine receptors did not change after the repeated MAP administration. 5. The rate of increase in DA release induced by MAP was dependent on the duration of repeated administration, and there was no correlation between the intensity of stereotypy and the rate of increase in DA release induced by MAP. These findings suggest that enhancement in DA release is unlikely to be the sole cause of behavioral sensitization.

Animals↗

PubMed1997

Responsiveness of smooth muscle in the lower urinary tract of rabbits to various agonists.

1. We compared the responsiveness of smooth muscle in the lower urinary tract and prostate from rabbits to the agonists noradrenaline, phenylephrine, clonidine, acetylcholine, prostaglandin F2 alpha, and histamine. 2. These agonists contracted smooth muscle in the lower urinary tract and prostate. In terms of maximal developed tension, contractile responses to the agonists were produced in the following order of potency: acetylcholine > prostaglandin F2 alpha > histamine > or = phenylephrine > or = noradrenaline > clonidine in the urinary bladder body; acetylcholine = noradrenaline = phenylephrine > prostaglandin F2 alpha > histamine > or = clonidine in the urinary bladder base; noradrenaline > or = phenylephrine > or = clonidine > acetyl-choline > prostaglandin F2 alpha > or = histamine in the urethra; and noradrenaline > or = phenylephrine > histamine = acetylcholine = clonidine = prostaglandin F2 alpha in the prostate. 3. These results suggest that considerable responsiveness variation occurs in the lower urinary tract and prostate and support the idea that the urinary bladder body is primarily governed by cholinergic mechanisms (parasympathetic nerves), whereas the urethra and prostate are regulated by alpha 1-adrenergic mechanisms (sympathetic nerves) and the bladder base by both.

Acetylcholine↗

PubMed1997

Endothelin receptors and their cellular signal transduction mechanism in human cultured prostatic smooth muscle cells.

1. Endothelin (ET) receptors, and their cellular signal transduction mechanism, were characterized in a primary culture of human prostatic smooth muscle cells (HP cell). 2. [125I]-ET-1 and [125I]-ET-3 binding studies revealed that both ETA and ETB receptors were present in the HP cells, and the ratio of ETA to ETB receptors was 1.4:1. 3. Analysis of ET receptor mRNA by reverse transcription-polymerase chain reaction also demonstrated that HP cells express both ETA and ETB receptors. 4. ET-1 and ET-3 increased intracellular free Ca2+ concentration ([Ca2+]i) in the HP cells in a concentration-dependent manner. Use of subtype selective antagonists BQ-123 and BQ-788, indicated that both ETA and ETB receptors were coupled to an increase in [Ca2+]i. 5. Pretreatment of the cells with pertussis toxin resulted in a significant but partial attenuation of the [Ca2+]i increase mediated through the ETA and ETB receptors. However, sensitivity to pertussis toxin (PTX) was significantly different between them. 6. In conclusion, HP cells possess ETA and ETB receptors. Further, these two endothelin receptor subtypes evoke an increase in [Ca2+]i possibly via the action of different GTP-binding proteins.

Calcium↗

PubMed1997

Galactorrhoea and amenorrhoea due to an intradural neurinoma originating from a thoracic intercostal nerve radicle.

A 42-year-old woman had galactorrhoea and amenorrhoea. Four years previously she complained of sensory disturbance of her legs, with galt disturbance. Serum PRL level was 1408 mU/l. Magnetic resonance imaging showed a spindle-shaped mass in the spinal canal at the level of the ninth thoracic vertebra. The tumour was removed and histologically was found to be a neurinoma originating from the right ninth intercostal nerve radicle. Soon after the operation, galactorrhoea, amenorrhoea and neurological symptoms disappeared. Prolactin levels normalized at 346 mU/l. These findings indicate that hyperprolactinaemia occurred as a result of the stimulation of afferent fibres from an intercostal nerve in a patient with intradural neurinoma of the intercostal nerve radicle.

Adult↗

PubMed1997

Antithyroid therapy improves bony manifestations and bone metabolic markers in patients with Graves' thyrotoxicosis.

OBJECTIVE: Abnormal bone metabolism in patients with Graves' thyrotoxicosis is well documented, but the precise time-course of its recovery remains poorly understood. The present study was undertaken to clarify longitudinal improvement in bony manifestations, especially in cortical bone, and bone metabolic markers in thyrotoxicosis. DESIGN: Two year prospective follow-up study in patients with Graves' disease. PATIENTS: Ten consecutive patients with Graves' disease (seven males and three females, of mean (+/-SEM) age 39.3 +/- 3.9 years) were enrolled in the study and treated with antithyroid drugs. Thirteen sex- and age-matched patients with the disease in remission served as controls. MEASUREMENTS: Bony manifestations were evaluated both by fine cortical bone striations in the metacarpals on magnified roentgenograms and lumbar bone mineral density (BMD) measurement. Urinary deoxypyridinoline (dPYR) and serum pyridinoline cross-linked telopeptide domain of type I collagen (ICTP) were monitored as markers of bone resorption, as well as serum osteocalcin (OC), carboxy-terminal propeptide of type I procollagen (PICP) and alkaline-phosphatase (ALP) as markers of bone formation. RESULTS: Initial elevated free thyroid hormone levels were normalized within a month of starting therapy. Striation indices of the metacarpals were 1.89 +/- 0.16 before therapy, higher than those of 0.49 +/- 0.12 in the controls (P < 0.0001); the indices gradually decreased to 1.00 +/- 0.20 (12 months) and 0.48 +/- 0.12 (24 months). Lumbar BMD Z-scores increased from -0.22 +/- 0.46 to 0.21 +/- 0.47 (12 months) and 0.68 +/- 0.48 (24 months) (P = 0.0029). Before therapy, urinary dPYR and serum ICTP concentrations were much higher than the control values (dPYR, +553%; ICTP, -396%, P < 0.0001), which declined promptly in the 2nd month. Serum OC, PICP and ALP were also significantly higher than in controls at first (OC, +287%; PICP, +225%; ALP, +196%), and remained elevated until 4 or 8 months. CONCLUSIONS: Bone resorption and cortical bone striations occur in untreated patients with Graves' thyrotoxicosis. The bone resorption rapidly ameliorates after normalization of thyroid hormone levels. In contrast, the accelerated bone formation persists for at least 4-8 months, suggesting positive uncoupling of bone remodelling. This dominant bone formation could result in the improvement in cortical bone striations and the increase in bone mineral density of trabecular bone.

Adolescent↗

PubMed1997

Gastrointestinal autonomic nerve tumor with giant abscess. A case report and literature review.

We report a gastrointestinal autonomic nerve tumor of the stomach with a giant abscess. The patient had fever and pain and was found to have anemia and an abdominal mass. X-ray and endoscopic examination showed a gastric submucosal tumor with a fistula to the gastric lumen. Partial gastrectomy was performed and no metastasis was found. On gross examination, the excised tumor was seen to be a submucosal solid tumor with a giant abscess. Alpha streptococci and anaerobic gram-negative rods were cultured from the pus of the abscess. The tumor resembled a gastric myogenic tumor composed of spindle cells, partly showing storiform and epithelioids. Tumor cells showed positive staining for vimentin and neuron-specific enolase but were negative for desmin, alpha-smooth muscle actin, and S-100 protein. Ultrastructural examination showed remarkable interdigitation of cytoplasmic processes with neurosecretory granules between the tumor cells. This lesion was similar to previously described gastrointestinal autonomic nerve tumors. Gastrointestinal autonomic nerve tumors are a rare, distinct subtype of gastrointestinal stromal tumors; although several cases of focally necrotic tumors have been reported, there has been only one report of the tumor with an abscess, as in our case.

Abscess↗

PubMed1997

Changes in serum pepsinogen, gastrin, and immunoglobulin G antibody titers in helicobacter pylori-positive gastric ulcer after eradication of infection.

There are no studies of changes in immunoglobulin G (IgG) titers to Helicobacter pylori, serum pepsinogen, and gastrin in patients with H. pylori-positive gastric ulcers. We investigated the effect of therapy for H. pylori-positive gastric ulcer on IgG titers to H. pylori, serum pepsinogen I and II, and gastrin. Thirty-six patients with H. pylori-positive gastric ulcer were treated with lansorazole and antibiotics for 2 weeks. Serum pepsinogen I and II concentrations, serum gastrin, and IgG titers to H. pylori were measured before treatment and then at 4 and 12 weeks after stopping the treatment. The presence or eradication of H. pylori was determined using the rapid urease test and by histologic H. pylori staining. For 19 patients in whom H. pylori had been successfully eradicated, the pepsinogen I/II ratio increased, pepsinogen II levels decreased, and the anti-H. pylori IgG decreased compared with the results from before therapy and with those from 4 and 12 weeks after therapy. Gastrin levels decreased compared with pretreatment results and those from 4 weeks after the end of treatment. In 17 patients in whom the therapy failed to eradicate H. pylori infection, there were no sequential significant changes in the pepsinogen I/II ratio or in the levels of pepsinogen I, pepsinogen II, anti-H. pylori IgG, and gastrin. A decrease in the serum levels of the IgG antibody to H. pylori and gastrin and also an increase in the pepsinogen I/II ratio could be used as predictors for the eradication of H. pylori infection in gastric ulcer.

Aged↗

PubMed1997

A case of systemic malignant lymphoma with intestinal involvement of lymphomatous polyposis type.

Multiple lymphomatous polyposis is a rare type of intestinal lymphoma characterized by non-Hodgkin's lymphoma of follicular mantle cell origin and extremely poor prognosis. We report a case of systemic lymphoma with the intestinal involvement of multiple lymphomatous polyposis. Although radiographic and endoscopic features of the case were compatible with multiple lymphomatous polyposis, histologic evidence suggested the diagnosis of diffuse large cell lymphoma rather than mantle cell lymphoma. Our case seems to be unique in its histologic findings and also in its prognosis, because the patient has been alive for more than 50 months after diagnosis.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1997

Hemodynamic characterization of YM435, a novel dopamine DA1 receptor agonist, in anesthetized dogs.

The cardiovascular effects of YM435, a dopamine DA1 receptor agonist, were compared with those of dopamine in open-chest anesthetized dogs. Intravenous infusion of YM435 (0.1-3 microg/kg/min) increased renal blood flow and cardiac output and reduced renal vascular resistance and total peripheral vascular resistance, with a decrease in mean blood pressure, in a dose-dependent manner, with little change in heart rate. At 1 microg/kg/min i.v., renal blood flow increased by 20 +/- 7%, cardiac output increased by 14 +/- 6%, renal vascular resistance decreased by 22 +/- 4%, total peripheral vascular resistance decreased by 18 +/- 4%, and mean blood pressure decreased by 7 +/- 1%. The striking difference between the cardiovascular effects of YM435 and those of dopamine was that YM435 caused no vasoconstriction or increase in heart rate, even at high doses. The cardiovascular effects of YM435 (1 microg/kg/min i.v.) were almost completely inhibited by treatment with SCH 23390, a selective dopamine DA1 receptor antagonist. Furthermore, intravenous infusion of YM435 (0.1-3 microg/kg/min) dose-dependently reversed the increase in blood pressure and renal vascular resistance induced by angiotensin II or norepinephrine in closed-chest anesthetized dogs. Our results demonstrate that intravenous infusion of YM435 produces dose-dependent renal vasodilating and hypotensive effects by stimulation of dopamine DA1 receptors and suggest that YM435 may be useful for the parenteral treatment of acute elevation of blood pressure.

Angiotensin II↗

PubMed1997

Acoustic characteristics of the piriform fossa in models and humans.

The piriform fossa forms the bottom part of the pharynx and acts as a pair of side branches of the vocal tract. Because of its obscure form and function, the piriform fossa has usually been neglected in the current speech production models. This study examines the geometric and acoustic characteristics of the piriform fossa by means of MRI-based mechanical modeling, in-vivo experiments and numerical computations. Volumetric MRI data showed that the piriform fossa is 2.1 to 2.9 cm3 in volume and 1.6 to 2.0 cm in depth for four Japanese subjects (three males and one female). The results obtained from mechanical models showed that the piriform fossa contributes strong troughs, i.e., spectral minima, to speech spectra in a region of 4 to 5 kHz. The antiresonances were identified with increasing frequency when water was injected into the piriform fossa of human subjects in in-vivo experiments. Antiresonances obtained from the experiments and simulations were confirmed to be consistent with those in natural speech within 5%. Acoustic measurements and simulations showed that the influence of the piriform fossa extends to the lower vowel formants in addition to the local troughs. This global effect can be explained by the location of the fossa near the glottal end of the vocal tract.

Female↗

PubMed1997

Urinary excretion of aquaporin-2 in the diagnosis of central diabetes insipidus.

We determined whether alteration in urinary excretion of aquaporin-2 (UAQP-2) is of value to diagnose central diabetes insipidus (CDI). First, UAQP-2 was determined in 16 normal subjects under ad libitum water drinking (n = 6) and after an overnight dehydration (n = 10). UAQP-2 has a positive correlation with plasma arginine vasopressin (AVP) levels (r = 0.61, P < 0.05) but not with urinary osmolality (Uosm). Second, a hypertonic saline (5% NaCl)-infusion test was studied in 5 normal subjects (21 to 25 yr old) and 10 patients with CDI (22-68 yr). After drinking water ad libitum, they were given 20 mL/kg water orally and then given 5% NaCl (0.05 mL/kg x min) i.v. for 120 min. Finally, 0.1 U of AVP was administered i.v. During the period, 30-min urine collections were made. In the normal subjects, after the infusion of 5% NaCl, plasma AVP levels and Uosm markedly increased in parallel with an increase in plasma osmolality (Posm, 294-320 mOsm/kg H2O; Uosm, 102-737 mOsm/kg H2O; AVP, 0.4-2.6 pg/mL, P < 0.001). In the CDI patients, plasma AVP and Uosm failed to increase, despite an increase in Posm (Posm, 306-332; Uosm, 102-164; AVP, 0.9-1.2). UAQP-2 was markedly greater in the normal subjects than the CDI patients (7.2 vs. 0.9 pmol/L/mg creatinine, P < 0.05) under water intake ad libitum. UAQP-2 was changeable in the wide range in physiological condition. After the 5%-NaCl infusion, UAQP-2 elevated to 12.5 from 0.9 pmol/L x mg creatinine in the normal subjects. In contrast, UAQP-2 remained low during the 5%-NaCl infusion in the CDI patients. Exogenous AVP promptly increased UAQP-2 to a similar extent in two groups of the normal subjects and the CDI patients. These results indicate that measurement of UAQP-2 is of value to diagnose CDI in the 5%-NaCl infusion test.

Adult↗

PubMed1997

Somatostatin receptor subtype 2 knockout mice are refractory to growth hormone-negative feedback on arcuate neurons.

The pulsatile nature of GH release is apparently regulated by alternating sequential changes in two hypothalamic hormones, GH releasing hormone (GHRH) and somatostatin. Entrainment of this pulsatility appears to involve GH-mediated negative feedback. Recently a new receptor involved in GH release was cloned. Activation of this receptor by GH-releasing peptides and MK-0677 initiates and amplifies GH pulsatility and is associated with increased Fos immunoreactivity and electrical activity in GHRH containing arcuate neurons. We show that pretreating mice with GH blocks activation of these neurons by MK-0677. Similarly, octreotide inhibited the action of MK-0677. To determine whether this GH-mediated negative feedback on GHRH neurons was direct, or by GH stimulation of somatostatin release from periventricular neurons, we selectively inactivated the gene for one of the five specific somatostatin receptor subtypes (subtype 2). In the knockout mice, both GH and octreotide failed to inhibit MK-0677 activation of arcuate neurons. GH did, however, increase Fos immunoreactivity in the periventricular nucleus, consistent with GH stimulation of somatostatin release from periventricular neurons. Thus, GH-mediated negative feedback involves signaling between periventricular and arcuate neurons with the signal being transduced specifically through somatostatin subtype 2 receptors.

Animals↗

PubMed1997

Springtime peaks of trace metals in Antarctic snow.

Drifting snow samples were collected at Asuka Station (71 degrees 32'S, 24 degrees 08'E, 930 m above sea level) over a period from July to December 1991; 36 elements (including Na, Mg, K, Ca, Fe, Al, Li, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Se, Rb, Sr, Cd, Pb, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Th) in snow were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) by direct sample introduction. Concentrations of Cl-, NO3-, and SO(4)2- in the snow were also determined by ion chromatography. In late September to early October, there was a pronounced peak concentration of most of the elements together with non-sea salt sulfate. Enrichment factor analyses suggest that Na, Mg, Ca, K, and Sr are of marine origin and Al, Fe, Mn, Rb, Cr, Ni, Ga, V, and all the rare earth elements are of crustal origins. Volcanic eruption of Mt. Pinatubo (June 1991) and Mt. Hudson (August 1991) could be the reason for the precipitation of Pb, Cd, Cu, Zn, and Se together with non-sea salt sulfates in the austral spring at Asuka Station.

Meteorological Concepts↗

PubMed1997

Effects of apolipoprotein E phenotype on serum cholesterol level and cholesterol response to diet therapy in patients with hypercholesterolemia.

We investigated the association of the apolipoprotein (apo) E isoform phenotype with the basal serum cholesterol level and cholesterol response to diet therapy in outpatients with primary hypercholesterolemia. The basal levels of serum cholesterol, triglyceride and HDL-cholesterol in the 132 subjects were 286 +/- 26 mg/dl, 154 +/- 83 mg/dl and 54 +/- 14 mg/dl, respectively. The frequencies of apo E 3/2, 3/3, 4/2, 4/3 and 4/4 were 1, 104, 2, 24 and 1, respectively. There were no differences in serum lipids between subjects with the two most common apo E phenotypes, i.e., apoE 3/3 (n = 104) and apoE 4/3 (n = 24). The serum cholesterol response to diet therapy was evaluated by measuring the serum lipids of 52 participants before and 2-3 months after diet therapy. After dietary counselling, serum cholesterol values were reduced significantly from 293 +/- 27 to 256 +/- 36 mg/dl (P < 0.01) in the total group of study subjects. There was no significant difference in serum cholesterol reduction in response to diet therapy between subjects with apoE4 (E4/2, E4/3 and E4/4, n = 12) and without apoE4 (E3/3 and E3/2, n = 40). Following dietary counselling, patients who lost a large amount of body weight (BM I > or = 1.0) exhibited a greater reduction in serum cholesterol than those who showed less weight loss. In conclusion, the results of our study demonstrated the primary importance of diet therapy in the treatment of hypercholesterolemia, although other investigators have suggested that apo E phenotypes influence the response of serum cholesterol to dietary changes.

Adult↗

PubMed1997

Alterations of lymphocyte subsets in patients with recurrent fetal wastage positive for antiphospholipid antibodies treated with Chinese herbal medicine.

The alterations of peripheral blood lymphocyte subsets were sequentially analyzed in patients with recurrent fetal wastage who were treated with the Chinese herbal medicine, Sairei-to (Chan ling-Tan) for positive antiphospholipid antibodies to analyze the underlying mechanisms of the therapy. The titer of antiphospholipid antibodies was significantly decreased by administration of Sairei-to at one and two months after commencement of treatment and in the newly pregnant state compared with that before administration. The percentage of CD19-positive cells significantly decreased at two months after commencement of Sairei-to treatment and at the newly pregnant state compared with that before administration in successful pregnancies. The percentage of CD4-positive cells significantly increased two months after commencement of Sairei-to treatment compared with that before administration in both successful pregnancies and total cases. The CD4/CD8 ratio was increased significantly after two months administration of Sairei-to in both successful pregnancies and total cases. Thus, it is suggested that the administration of Sairei-to might induce the predominance of CD4-positive cells in parallel with the suppression of antiphospholipid antibodies. Moreover, the suppression of CD19-positive cells (B cells) was induced by administration of Sairei-to which might be involved in successful continuation of pregnancy in the patients.

Abortion, Habitual↗

PubMed1997

Immunosuppressive therapy for recurrent aborters with positive antiphospholipid antibodies and alteration of 6ketoPGF1 alpha/TXB2 ratio.

Twelve women (13 pregnancies) with antiphospholipid antibodies (APA) who had suffered from two or more recurrent spontaneous abortions or fetal deaths and had successful pregnancy outcomes after immunosuppressive therapy were studied. APA titers were determined by enzyme-linked immunosorbent assay against cardiolipin, phosphatidyl serine and phosphatidyl inositol. Plasma levels of 6ketoprostaglandin F1 alpha (6ketoPGF1 alpha) and thromboxane B2 (TXB2) were determined by radioimmunoassay. All of the 13 pregnancies resulted in term delivery. None of the 13 patients suffered from pregnancy-induced hypertension, and only one showed intrauterine growth retardation. A significant decrease of APA titer was observed after immunosuppressive therapy. The 6ketoPGF1 alpha/TXB2 ratios before the therapy, after it and at the 1st, 2nd and 3rd trimesters of pregnancy were 0.62 +/- 0.398, 0.88 +/- 0.106, 0.84 +/- 0.550, 1.25 +/- 0.834 and 0.67 +/- 0.413, respectively. The ratio at the 2nd trimester was significantly higher than that before the therapy (P < 0.05, paired t-test, n = 9). The results indicate that the immunosuppressive therapy affected the physiological balance between thromboxane A2 and prostacyclin, and improved clinical symptoms such as recurrent fetal wastage.

6-Ketoprostaglandin F1 alpha↗

PubMed1997

Compatibility between auditory and articulatory representations of vowels.

Auditory-articulatory linkage in our brain plays an essential neurobiological role in human speech communication. Speech-specific sensorimotor organization is basically a genetically transmitted program, whereas its ontogenetic outcome may strongly reflect the unique form of human vocal organs. In this study, electromyographic data from the four extrinsic tongue muscles were processed to derive motor targets of vowels in a two-dimensional space representing muscle force equilibrium. The result shows evidence that the motor pattern of tongue muscles in vowel production is compatible with the acoustic pattern of vowels: the distribution of intended targets of tongue movement resembles the vowel distribution in the auditory (F1 vs. F2) space. This coincidence suggests a co-evolution of the human vocal tract and vowel system that facilitates the development of efficient auditory pathway for processing speech sounds.

Auditory Pathways↗