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Biomedical subjects

H Saitoh

Publications and source records attributed to H Saitoh.

At least 217 records · Page 12Linked to original sources
PubMed1995

Cartinoid tumor of the middle ear and mastoid.

Primary cartinoid tumors in the middle ear and mastoid are rare. They are also very difficult to distinguish from adenomas and adenocarcinomas, using conventional histological stains. We present clinical, histological, immunohistochemical and ultrastructural findings of a cartinoid tumor in the middle ear and mastoid in a 40-year-old male. A soft tumor was revealed in the posterior mesotympanum and mastoid cavity, and a radical tympanomastoidectomy was performed. The tumor cells were stained by chromogranin A, and neurosecretory granules were confirmed with electron microscopy. We also review 20 previously reported cases in regard to their presentation, symptoms, signs, tumor extension, treatments, and histopathology.

Adenocarcinoma↗
PubMed1995

Possible involvement of multiple P-glycoprotein-mediated efflux systems in the transport of verapamil and other organic cations across rat intestine.

PURPOSE: We investigated the intestinal transport of verapamil, chlorpromazine, and propantheline, particularly their P-glycoprotein-mediated secretion. METHODS: Permeation of rat intestinal segments in vitro was determined using diffusion cells. RESULTS: Verapamil permeation in the serosal-to-mucosal direction was much greater than in the mucosal-to-serosal direction using duodenal, jejunal, and colonic membranes. The concentration dependence of jejunal permeation in the absorptive and secretory directions was consistent with saturability of a secretory transport system. Using a monoclonal antibody to inhibit P-glycoprotein-mediated secretion caused a significant enhancement of verapamil absorption through the jejunum. In contrast, the rat ileum did not preferentially transport verapamil in the secretory direction, and the P-glycoprotein antibody had no effect on ileal absorption. Chlorpromazine and propantheline enhanced the mucosal-to-serosal permeation of verapamil through the jejunum, most likely due to competitive inhibition of the P-glycoprotein-mediated secretory process. Vinblastine, tetraethylammonium, and guanidine did not affect verapamil permeation. Propantheline was also a substrate for P-glycoprotein-mediated secretory transport, but in contrast to verapamil, propantheline secretory transport was expressed in rat ileum. CONCLUSIONS: These results suggest that these cationic compounds are transported by plural P-glycoprotein-mediated efflux systems with different substrate specificities depending on the intestinal site.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Prodrugs to improve the oral bioavailability of a diacidic nonpeptide angiotensin II antagonist.

DMP 811 is a diacidic angiotensin II antagonist. It has relatively low oral bioavailability in rats. A prodrug approach to improving oral bioavailability was tested. Five esters were synthesized and their stability in rat plasma in vitro was determined. The hydrolysis rates of these five esters ranged from almost immediate to negligible. A simple n-propyl ester was hydrolyzed very slowly (< 10% in 24 hr) in rat plasma in vitro, and after oral dosing in rats plasma prodrug concentrations were much greater than DMP 811 concentrations. A pivaloyloxymethyl ester (1) was hydrolyzed relatively rapidly in rat plasma in vitro. Prodrug 1 was rapidly hydrolyzed by the intestine in vitro, and the intestinal permeation of DMP 811 was increased. DMP 811 oral bioavailability was 47% in rats dosed with 10 mg/kg 1, compared to 11% for rats dosed with 10 mg/kg DMP 811. However, DMP 811 bioavailability was only 27% after a 2 mg/kg dose of 1. In vitro plasma hydrolysis of 1 was highly species-dependent, with a half-life of 13 hr in human plasma but only 1 min in rat plasma. The prodrug approach has potential for improving the oral bioavailability of DMP 811, but selection of the optimal prodrug must be done in humans or in a species, such as dogs, with hydrolysis characteristics closer to humans.

Administration, Oral↗
PubMed1995

Bacillus thuringiensis serovar higo (flagellar serotype 44), a new serogroup with a larvicidal activity preferential for the anopheline mosquito.

Eight strains of Bacillus thuringiensis, isolated in Japan, formed spherical parasporal inclusions and exhibited low to moderate larvicidal activities for two mosquito species, Anopheles stephensi and Culex pipiens molestus, but not for another dipteran, Telmatoscopus albipunctatus, or two lepidopterans, Bombyx mori and Hyphantria cunea. The anopheline toxicity (LC50 = 6.3 micrograms ml-1) was > 10 times greater than the activity on the Culex mosquito. These strains were assigned to a previously undescribed flagellar (H) antigenic group. On the basis of the representative strain, 92-KU-137-4, a serogroup with H antigen 44, Bacillus thuringiensis serovar higo was established as new.

Animals↗
PubMed1995

Pneumatosis cystoides intestinalis after chemotherapy for hematological malignancies: report of 4 cases.

Pneumatosis cystoides intestinalis (PCI) is known to be a relatively rare condition which is characterized by gas cysts in the gastrointestinal mucosa. We treated four cases of PCI accompanied by hematological malignancies during chemotherapy treatment. All cases suffered from abdominal discomfort. Abdominal X-ray films revealed gas cysts in the intestine. PCI was observed during leukocytopenic states, and three cases had septicemia. Etoposide was administered to three cases, and prednisolone to all cases. It is considered that PCI sometimes occurs in patients with hematological malignancies during a period of leukocytopenia, and may be caused by intestinal mucosal damage due to myelosuppressive agents and immunosuppression from prednisolone.

Adult↗
PubMed1995

[The clinical usefulness of urinary determinations of cytokeratin 19 fragment (CYFRA 21-1) in urothelial tumor].

The urinary CYFRA 21-1 value corrected for urinary creatinine (ng/ml/creatinine), was studied in the urine of patients with urothelial tumors. To examine its clinical significance we studied urinary CYFRA 21-1 excretion (ng/ml/creatinine), in a total of 22 urine samples from patients with bladder cancer, 7 from patients with renal pelvic and ureteral tumor, 6 from patients with urinary infection 6 from patients with urinary diversion called ileal conduit, and 8 from healthy adult men. The excretion of CYFRA 21-1 in urine was determined by two specific monoclonal antibodies (Ks 19.1 and BW 19.21). The mean value of urinary CYFRA 21-1 in healthy adult men was 1.96 +/- 1.33 (mean +/- SD) ng/ml/creatinine. Urinary CYFRA 21-1 showed a higher value in the urine of urinary infection and urinary diversion. As to bladder cancer, urinary CYFRA 21-1 showed a higher value in a larger volume of tumor than in a smaller volume of tumor in transitional cell carcinoma regardless of the grade and stage. These findings suggest that urinary CYFRA 21-1 may be a non-specific marker in urothelial tumors.

Adult↗
PubMed1995

FK506 treatment of graft-versus-host disease developing or exacerbating during prophylaxis and therapy with cyclosporin and/or other immunosuppressants. Japanese FK506 BMT Study Group.

A phase II study of the efficacy and safety of FK506, a new potent immunosuppressant, has been conducted in 49 patients with GVHD after allogeneic BMT. Eighteen patients with acute GVHD and 31 with chronic GVHD entered the study. FK506 was administered at an initial dose of 0.05 mg/kg i.v. or 0.15 mg/kg orally twice a day to those whose GVHD had become uncontrollable with cyclosporin and/or other immunosuppressants. The response to FK506 was evaluated in 13 patients with acute and 26 with chronic GVHD. A marked response was observed in 5 and a good response in 2 of 13 patients with acute GVHD. For those with chronic GVHD, the response was marked in 2 patients, good in 10 and poor in 8. The most common adverse effects were renal toxicity (53.1%), followed by nausea and vomiting (30.6%) and a feeding of warmth (18.4%). There was a correlation between renal toxicity and whole blood levels of FK506. The dose should be adjusted to keep a trough level between 15 and 25 ng/ml. FK506 is promising in the treatment of both acute and chronic GVHD, even if it is intractable with other immunosuppressants, and may be most effective if administered early in the course of GVHD.

Acute Disease↗
PubMed1995

[Extracorporeal shock wave lithotripsy on patients with spinal cord injury with special reference to autonomic hyperreflexia].

We performed treatment of urolithiasis on 7 patients with spinal cord injury (6 males and one female, with a mean age of 41 years old) by extracorporeal shock wave lithotripsy (ESWL) using a Lithostar (Siemens). The level of injury was cervical in 3 patients and lower thoracic in 4. The treated stones were renal in 6 patients, including one staghorn caliculus, ureteral in 2, and bladder stones in 2 patients. ESWL was performed under general anesthesia in 2 patients, and in another patient, epidural anaesthesia was employed in the first several sessions, but thereafter treatment was safely continued with no anesthesia. The other 4 patients were treated without anesthesia. In most patients, the stones (9 stones in 6 cases) were easily disintegrated after treatment of from one to 14 sessions, except one case of staghorn caliculus, and the clearance of fragments was also satisfactory. In one patient, hypertension and bradycardia due to autonomic hyperreflexia were observed during ESWL, and the treatment was discontinued, but the stone was successfully disintegrated and the fragments were voided. In another patient, autonomic hyperreflexia was observed while the fragments passed through the ureter, although no signs of this reflexia were seen during the ESWL procedure.

Adolescent↗
PubMed1995

[Extracorporeal shock wave lithotripsy monotherapy using Lithostar--factors influencing actuarial residual stone rates].

For the evaluation of post treatment course after initial extracorporeal shock wave lithotripsy (ESWL) as a monotherapy using the Lithostar, the actuarial residual stone rate (ARSR) was calculated by the Kaplan-Meier formula in 713 calculi (255 renal and 458 ureteral calculi). ARSRs in all calculi at 3, 6, 12 and 48 months were 41.6, 30.5, 20.6 and 10.3%, respectively. Significantly higher ARSRs were observed in the following former group compared to the latter: large calculi to small or middle sized calculi, renal calculi to ureteral calculi (small or middle sized), and plural renal calculi (middle sized) to single renal calculi (middle sized). There was no significant difference either between large renal and large ureteral calculi, or overall single and plural calculi. These findings show that ARSRs calculated by the Kaplan-Meier formula clearly reveal factors influencing the ESWL effects.

Follow-Up Studies↗
PubMed1995

Rerupture of cerebral aneurysms during angiography.

PURPOSE: To assess the incidence of angiography-related rerupture of intracranial aneurysms and to analyze other risk factors of this complication. METHODS: Clinical data from 144 patients with acute subarachnoid hemorrhage from ruptured intracranial aneurysm were reviewed retrospectively. In all patients, angiography was done by the transaortic approach. RESULTS: The incidence of rerupture caused by angiography was 2 (1.4%) of 144 and that of spontaneous rerupture was 14 (9.7%) of 144. Angiography within 6 hours after the initial subarachnoid hemorrhage attack was associated with a significantly higher incidence of rerupture (4.8%) than that after a longer interval (0%). In cases of spontaneous rerupture, patients with worse levels of consciousness showed a higher incidence of rerupture, and this tendency also was evident in cases of induced rerupture. There was no significant correlation between the rerupture rate and the injection volume of contrast medium, aneurysm location, or patient age or sex. CONCLUSION: Although angiography within 6 hours after initial intracranial aneurysm rupture was associated with a higher rate of rerupture, the incidence of rerupture in this study (4.8%) was much lower than those reported previously (20% to 38.5%). The present findings suggest that emergency angiography within 6 hours after aneurysm rupture, which enables neurosurgeons to carry out early surgery, should not be discouraged.

Aged↗
PubMed1995

Studies on the development of the articular part of the temporal bone with special reference to the postglenoid process.

The development and significance of the postglenoid process on the articular surface of the temporal bone were studied using 217 Indian skulls, which were divided by their level of tooth eruption into 6 developmental stages; preeruption period (Stage I), initial stage (m1 eruption) of the deciduous dentition period (Stage II), middle stage (m2 eruption) of the deciduous dentition period (Stage III), late state (eruption of 20 deciduous teeth) of the deciduous dentition period (Stage IV), mixed dentition period (Stage V), and permanent dentition period (Stage VI). Each skull was mounted on a Kraniophor in such a way that the auriculoorbital (Frankfurt) plane was positioned vertical to the horizontal plane and photographed at a focal distance of 40 cm. Using the Frankfurt plane as a base line, the vertical distances to the lowest point of the postglenoid process (a-A), to the deepest point of the mandibular fossa (b-B), and to the mid-point of the articular tubercle (c-C) were measured. The distances from various points of the mandibular fossa to the articular surface of the temporal bone were measured at the level of the Frankfurt plane. The results may be summarized as follows: The length of the postglenoid process as measured from the Frankfurt plane was 0.58 mm at Stage I and 0.75 mm at Stage II. It increased by 0.6-1.0 mm at each developmental stage. By Stage VI, it had increased to 3.85 mm (six- to seven-fold increase from the initial value). The anteroposterior width of the postglenoid process remained almost unchanged throughout the developmental stages. The growth of the articular structures of the temporal bone from the preeruption to deciduous dentition period increased 73% in the total anteroposterior dimension (5.22 mm) and 44% in the total vertical dimension (3.32 mm). The vertical dimension of the mandibular fossa began to rapidly increase following the eruption of the deciduous first molars.

Adolescent↗
PubMed1994

[Studies on patients with a discrepancy between free thyroid hormones and thyrotropin values].

Thyroid function has been almost exactly evaluated by the measurement of serum free thyroxine (FT4), free triiodothyronine (FT3) and thyrotropin (TSH) concentrations. However, we occasionally experience patients who show a discrepancy between free thyroid hormones and TSH values, and the assessment of thyroid function in such cases is extremely difficult. Thyroid hormone autoantibodies (THAA) interfere with radioimmunoassay (RIA) of FT4 and FT3 by giving inappropriate values. To investigate the incidence of THAA, immune precipitation of patients' sera after incubation with labelled T4 (125I-T4) or T3 (125I-T3) analog tracer was done in 394 patients with thyroid diseases. 9 patients (2.3%) showed an increased binding of 125I-T4 or 125I-T3 analog. Heterophilic antimouse antibodies in a patient's serum (human antimouse immunoglobulin antibodies: HAMA) can interfere in two-site immunometric assays (IMA) using mouse monoclonal antibodies and result in spuriously increased serum TSH concentrations. Manufacturers now customarily add nonspecific mouse immunoglobulins into their assay kits to absorb HAMA and prevent such interference. This approach may not always be enough to prevent HAMA interference in all samples. In 14 thyrotoxic patients with inappropriately high TSH measured by an IMA kit, we measured the levels of TSH by the further addition of mouse serum into this kit. Their serum TSH levels were fully suppressed except for 2 patients with a syndrome of inappropriate secretion of TSH (SITSH). The presence of abnormal albumin in the serum also interferes with RIA of FT4 and FT3. We experienced a female case of Graves' disease treated with methimazole who showed an inappropriately high serum FT3 measured by an analog tracer RIA kit, whose serum FT4, FT3 and TSH were 1.31 ng/dl, 19.3 pg/ml and 1.9 mu U/ml respectively. Although the anti-T3 autoantibody was considered to be present initially, immune precipitation of her serum with 125I-T3 analog tracer gave a negative result. In order to elucidate this finding, Sephadex-G200 chromatography of her serum after incubation with 125I-T3 analog tracer was done. Radioactivity of her serum in albumin fraction was significantly higher than that of normal control serum to indicate the presence of abnormal albumin in the serum. In conclusion, to assess the thyroid function of a patient with a discrepancy between free thyroid hormones and TSH values, it is important to consider the presence of THAA, HAMA, or rarely, an abnormal albumin.

Adult↗
PubMed1994

Characterization of hydrolysis and transglycosylation by testicular hyaluronidase using ion-spray mass spectrometry.

Various oligosaccharides from hyaluronic acid, which were fluorescence-labeled and blocked by pyridylamination at the reducing terminal, were incubated as substrates or acceptors with bovine testicular hyaluronidase. Fluorescence-labeled reaction products in the reaction mixture were monitored selectively and directly by ion-spray mass spectrometry without chemical derivatization. As a result, several features of the relationship between oligosaccharides, substrates, and testicular hyaluronidase were clarified. When hexasaccharides or larger oligosaccharides having D-glucuronic acid at the nonreducing terminal were used as substrates, they were hydrolyzed sequentially to disaccharides from the nonreducing terminal, and these disaccharides were then transferred to other hexasaccharides. On the other hand, when heptasaccharides or larger oligosaccharides having N-acetyl-D-glucosamine at the nonreducing terminal were used as substrates, trisaccharides were released from the nonreducing terminal, and then also transferred to other hexasaccharides, thus forming nonasaccharides. Thus, the relationship between hydrolysis and transglycosylation reactions with testicular hyaluronidase was characterized using ion-spray mass spectrometry.

Animals↗
PubMed1994

Pseudohypoparathyroidism-associated spinal stenosis.

STUDY DESIGN: Pseudohypoparathyroidism associated with disorders of the spine is rarely reported. In this report, the authors present a case of pseudohypoparathyroidism in a 41-year-old man who had narrow spinal canal and multiple disc herniation in the cervical spine. SUMMARY OF BACKGROUND DATA: The patient had progressive spastic tetraplegia due to cervical cord compression caused by multiple disc herniations at the C3-C4, C4-5, and C5-C6 levels in the developmentally narrow spinal canal. Based on the features of Albright's osteodystrophy, serum laboratory results, and an Ellsworth-Howard test, the diagnosis of pseudohypoparathyroidism, type I was confirmed. METHODS: The patient underwent expansive laminoplasty at C3 through C6 levels. RESULTS: His symptoms have gradually improved during the 1-year and 6-month periods after the surgery. CONCLUSIONS: A case of pseudohypoparathyroidism-associated spinal stenosis was reported.

Adult↗
PubMed1994

CENP-C is required for maintaining proper kinetochore size and for a timely transition to anaphase.

The human autoantigen CENP-C has been demonstrated by immunoelectron microscopy to be a component of the inner kinetochore plate. Here we have used antibodies raised against various portions of CENP-C to probe its function in mitosis. We show that nuclear microinjection of anti-CENP-C antibodies during interphase causes a transient arrest at the following metaphase. Injection of the same antibodies after the initiation of prophase, however, does not disrupt mitosis. Correspondingly, indirect immunofluorescence using affinity-purified human anti-CENP-C antibodies reveals that levels of CENP-C staining are reduced at centromeres in cells that were injected during interphase, but appear unaffected in cells which were injected during mitosis. Thus, we suggest that the injected antibodies cause metaphase arrest by reducing the amount of CENP-C at centromeres. Examination of kinetochores in metaphase-arrested cells by electron microscopy reveals that the number of trilaminar structures is reduced. More surprisingly, the few remaining kinetochores in these cells retain a normal trilaminar morphology but are significantly reduced in diameter. In cells arrested for extended periods, these small kinetochores become disrupted and apparently no longer bind microtubules. These observations are consistent with an involvement of CENP-C in kinetochore assembly, and suggest that CENP-C plays a critical role in both establishing and/or maintaining proper kinetochore size and stabilizing microtubule attachments. These findings also support the idea that proper assembly of kinetochores may be monitored by the cell cycle checkpoint preceding the transition to anaphase.

Anaphase↗
PubMed1994

Prompt decrease of circulating hepatitis C virus in patients with chronic hepatitis C after treatment with interferon.

Patients with chronic hepatitis C were treated with interferon (IFN) and followed for hepatitis C virus (HCV) RNA and antibody to HCV (anti-HCV) in serum. The response was correlated with decrease in serum levels of HCV RNA, as well as HCV genotypes and liver histopathology. Response to IFN, estimated by clearance of HCV RNA and normalization of aminotransferase levels at 6 months after the withdrawal of IFN, was observed in 11 (31%) of 35 patients infected with HCV of genotype II/1b, 13 (72%) of 18 with genotype III/2a, and 2 (33%) of 6 with genotype IV/2b; a single patient with genotype I/1a responded while the one doubly infected with HCV of genotypes II/1b and IV/2b did not. Response was seen in 10 (71%) of 14 patients with chronic persistent hepatitis, 14 (39%) of 36 with chronic active hepatitis 2A, and 3 (27%) of 11 with 2B. Response was achieved less often in patients with high than low pretreatment levels of HCV RNA. HCV RNA dropped sharply on a day after the start of IFN, and continued to decrease during the 2 weeks, irrespective of the response to IFN or HCV genotypes. In contrast, anti-HCV decreased more gradually and only in responders to IFN. These results support the rapid development of an IFN-mediated antiviral effect on HCV, and support therapeutic effects of IFN dependent on histopathology of liver as well as HCV RNA titers and genotypes.

Alanine Transaminase↗