Biomedical subjects

S Katayama

Publications and source records attributed to S Katayama.

At least 253 records · Page 14Linked to original sources

PubMed1994

[A case of polycystic kidney associated with new growth of cerebral aneurysm after aneurysmal operation].

We have encountered a 66-year-old woman with a polycystic kidney (PCK). This was combined with the fact that the new growth of an aneurysm at the left anterior cerebral artery (A2-A3 junction) had ruptured 3 years after an operation for a right IC-PC aneurysm in 1985. The cause of the neogenesis and enlargement of an intracranial aneurysm is important because of the changes in the arterial wall due to congenital factors, hypertension, arteriosclerosis, etc, or hemodynamic stress caused by hypertension. We suspected that intracranial aneurysm formation was caused by hypertension due to PCK and the intracranial aneurysm is explained as being due to maldevelopment. In patients with PCK, it should be kept in mind that intracranial aneurysms may be present, and it is advisable to use cerebral angiography and MRA to see whether this is so or not. It should be also stressed that the control of hypertension is very important for the prognosis of patients with PCK. Not only new growth of cerebral aneurysms but also intracerebral hemorrhage is to be prevented.

Aged↗

PubMed1994

[A case of brain abscess of the basal ganglia which resulted in disastrous outcome due to ventricular ruptures].

A case of deep-seated brain abscess that ruptured twice into the ventricle and resulted in death is presented. A 45-year-old man had experienced pyrexia and headache for 3 days before admission. On admission he was somnolent (GCS: 13) but there were no abnormal neurological findings except nuchal rigidity and Kernig's sign. Computed tomography (CT) scan showed a ring enhanced mass near the left caudate head and dilated ventricles. In comparison with CT performed at the former hospital it was diagnosed that a rupture into the ventricle of the brain abscess had occurred. Ventricular drainage was performed at once and white purulent cerebrospinal fluid was obtained. Thereafter, he was treated with some antibiotics and his conditions seemed to stabilize for a while. Serial CT images demonstrated that the size of the abscess seemed to be enlarging. Just when we planned to undertake stereotactic aspiration, the second ventricular rupture occurred and he died. According to this case, it is suggested that once a deep-seated brain abscess near the ventricular system is suspected, it should be aspirated by means of CT-guided stereotactic surgery immediately.

Basal Ganglia Diseases↗

PubMed1993

[Evaluation of helical scan CT in the detection of lung nodules of pulmonary metastasis].

The purpose of this study was to evaluate the diagnostic capability of helical scan CT (HS-CT). We investigated the ability of HS-CT to detect lesions by scanning 129 small nodular lesions in the lung field in six cases of pulmonary metastasis. HS-CT was then employed to scan the same regions at table slide speeds of 20 mm/sec and 25 mm/sec. The acquired images were recorded on film and a video tape recorder (VTR), using axial multiplanar reconstruction. We then compared the various images to evaluate the effectiveness of conventional CT (slice thickness: 10 mm, table slide pitch: 10 mm) and HS-CT in visualizing the lesions. HS-CT images acquired at 20 mm/sec and at 25 mm/sec were equally effective in visualizing the lesions. Diagnostic capability was significantly lower in the apical area than in the middle and subdiaphragmatic areas. VTR images were better than film images in terms of diagnostic capability. The disadvantage of VTR images was that VTR processing required much time and labor, and thus is not practical at present. In conclusion, HS-CT is useful in detecting small nodular lesions in the lung field. However, the scanning conditions of HS-CT and interpretation of images, especially in the apical area, require further improvement.

Humans↗

PubMed1993

[Iodination and binding characteristics of 125I-d(CH2)5 [Tyr(Me)2, Tyr(NH2)9] AVP].

With iodinated vasopressin analogue, d(CH2)5[Tyr(Me)2, Tyr(NH2)9] AVP, at position 9, followed by purification by HPLC (specific activity 473-543Ci/mmol), a specific binding was observed in the rat liver plasma membrane fraction. Scatchard analysis indicated a single class of high-affinity binding sites with a Kd of 0.23nM and Bmax of 142fmol/mg protein. V2-agonist, DDAVP, did not displace 125I-vasopressin analogue. These results suggest that 125I-d(CH2)5[Tyr(Me)2, Tyr(NH2)9] AVP with a high specific activity is a useful tool to investigate V1-receptors.

Animals↗

PubMed1993

Relationship between osteopenia and clinical characteristics of Parkinson's disease.

Pathological bone changes affect locomotor activity and may influence the outcome and prognosis of Parkinson's disease (PD). In this study, we determined the relationship between bone changes and PD. Bone study was performed by multiple scanning x-ray photodensitometry (MD/MS) in 64 patients with PD and 42 age-matched controls. We then compared the results with the clinical characteristics of PD. Osteopenia was detected in 22 (53.6%) of the 41 female and 6 (26%) of the 23 male patients, and in 6 (26%) of the 23 female and 2 (10.5%) of the 19 male controls. The frequency of osteopenia was significantly greater in the female patients than in the male patients or the female controls. Osteopenia was related to the duration of PD in the men, but not in the women. Twenty of 40 PD patients' hands showed side-related differences in the analysis of both hands. In 19 of the 20 patients, the side of more severe osteopenia coincided with that of parkinsonian symptoms, suggesting that osteopenia is related to the pathophysiology of PD.

Absorptiometry, Photon↗

PubMed1993

CT and MRI of haemorrhage into intracranial neuromas.

Six patients with haemorrhage into intracranial neuromas were studied by computed tomography (CT) and magnetic resonance imaging (MRI) at 0.5 T with spin-echo pulse sequences. The nature of the tumour and the presence of a haematoma were confirmed by surgery and microscopic examination in all cases. Four neuromas arose from the acoustic nerves and two from the trigeminal. Four of the six patients suffered from sudden onset or rapid worsening of symptoms including headache, vertigo and/or hemifacial motor and sensory disturbances. CT in the acute stage revealed a hyperdense area or a fluid-fluid level (FFL). The hyperdense area disappeared on CT repeated in the chronic stage. On MRI in subacute and chronic stages the haemorrhage showed hyperintensity on both T1 and T2 weighting in five cases examined between 16 and 46 days after the onset, and isointensity on T1 weighting and an FFL on T2 weighting in one case examined 12 days after the onset of symptoms. A well-defined low intensity rim indicating prior haemorrhage was observed on T2-weighted images in three cases. MRI was more effective than CT in detecting haemorrhage into the tumours and in staging it.

Adult↗

PubMed1993

Evaluation of MRI score in the differentiation between glioblastoma multiforme and metastatic adenocarcinoma of the brain.

The authors statistically analyzed the MR configurations of 14 glioblastoma multiformes (GBMs) and 15 metastatic adenocarcinomas (MACs) of the brain in order to distinguish these two histological types on MR images. MR configurations were classified and scored upon the 9 criteria of heterogeneity, cyst or necrosis, haemorrhage, crossing of the midline by the tumour, oedema or mass effect, border definition, flow void sign, degree and heterogeneity after contrast enhancement. The mean value of GBMs was 1.47 +/- 0.22, and that of MACs was 0.91 +/- 0.37 (P < 0.001). GBMs had significantly higher values in five out of the nine criteria: border definition, heterogeneity, crossing of the midline of the tumour, flow void sign, and degree of the contrast enhancement (P < 0.001-0.05). Border definition was the best criterion for distinguishing two histological types. Six cases of MACs displayed hypo-intense lesions on T2 weighted images in contrast to GBMs which showed hyperintense lesions in all cases. In 4 out of the 6 MACs which were shown as hyperintensities on T2 weighted images, a hypo-intense peritumoural rim was noticed between the tumour parenchyma and the surrounding oedema. These data strongly suggest that GBMs and MACs can be distinguished on MR image by using MRI score.

Adenocarcinoma↗

PubMed1993

Alteration of the basement membrane in human thyroid diseases: an immunohistochemical study of type IV collagen, laminin and heparan sulphate proteoglycan.

Basement membrane (BM) alteration in thyroid diseases was examined by immunohistochemistry using antibodies for the three major BM proteins: type IV collagen, laminin and heparan sulphate proteoglycan. Linear epithelial BMs surrounding follicles accompanied by vascular BMs forming loops, similar to those seen in the normal thyroid, were observed in Graves' disease and adenomatous goitre. Hashimoto's thyroiditis showed scant epithelial BMs as a result of follicle destruction. In follicular adenomas, development of epithelial BMs seemed to be related to follicle formation; well-developed epithelial BMs were frequently seen in normo- or large-follicular type, whereas trabecular or solid types revealed scant or poorly developed epithelial BMs. Lumpy accumulation of BM proteins was detected in hyalinizing trabecular adenomas. Papillary carcinomas revealed two different types of papillae; one type contained both epithelial and vascular BMs, and the other had only vascular BMs. Epithelial BMs in invasive areas of papillary carcinoma were distributed in an irregular, interrupted manner, and were completely absent in many foci. Anaplastic carcinomas showed scant or a total loss of epithelial BMs. These results suggest that alterations of BM in thyroid diseases clearly reflect their architectural variations, presumably in connection with their function and/or biological behaviour.

Basement Membrane↗

PubMed1993

Deletion detection for diagnosis of Duchenne muscular dystrophy in the Japanese population--comparison between the polymerase chain reaction and the Southern blot analysis.

We compared the efficacy of the multiplex PCR with that of the cDNA analysis for detection of deletions of the DMD gene in the Japanese patients. Thirty males with DMD from 27 Japanese families were studied by the multiplex PCR, and 24 of them were also investigated by Southern blot analysis. We used five dystrophin cDNA probes for deletion analysis. A total of 19 regions were amplified by the PCR to detect deletions, 9 regions by the method of Chamberlain et al. and another 10 regions by the method of Beggs et al. Deletions were detected in 14 (52%) out of 27 DMD families by the PCR. Southern blot analysis detected deletions in 14 (64%) out of 22 families. Thirteen (93%) of the 14 DMD families with deletions detected by Southern blotting were also confirmed by the multiplex PCR. Provided care is taken in cases where the deletion is limited to a single exon, the multiplex PCR appears to be an efficient and useful alternative to conventional Southern blot analysis for detecting deletions during the prenatal and postnatal diagnosis of DMD.

Asian People↗

PubMed1993

Thapsigargin induces an endothelium-dependent, intracellular calcium ion-dependent vasodilation in vitro.

The effect of thapsigargin, a specific inhibitor of intracellular Ca(2+)-ATPases, on endothelium-dependent relaxation was studied in the guinea pig thoracic aorta. Thapsigargin (1 nM-1 microM) produced a concentration-dependent relaxation of aortic strips precontracted by phenylephrine (0.1 microM) in the presence and absence of extracellular Ca2+. Thapsigargin (0.1 microM-10 microM) produced the concentration-dependent contraction in aortic strips with no endothelium in the presence and absence of extracellular Ca2+. The relaxant effect of thapsigargin (1 microM) was not attained in a de-endothelialised aortic strip. NG-nitro-L-arginine (10 nM-0.1 mM), a blocker of NO synthase, produced a concentration-dependent inhibition of thapsigargin-induced relaxation. Thapsigargin failed to produce vasodilation by pretreatment of aortic strips with NG-nitro-L-arginine (10 microM). Thapsigargin (1 microM) increased tissue levels of guanosine 3', 5' cyclic-monophosphate in aortic strips preincubated with phenylephrine (0.1 microM). The results suggest that the intracellular Ca2+ mobilization in endothelial cells by thapsigargin is of significance in the endothelium-dependent relaxation of guinea pig thoracic aorta.

Animals↗

PubMed1993

Aetiology of Kienböck's disease based on a study of the condition among patients with cerebral palsy.

Examination of 110 patients with cerebral palsy revealed a diagnosis of Kienböck's disease in six wrists in five cases. All had cerebral palsy of the mixed type with athetosis and high muscle tone. It is considered that the increased prevalence of Kienböck's disease in these cases was attributable to repeated minor trauma to the lunate from childhood due to high muscle tone across the wrist joint, together with negative ulnar variance. The high prevalence of Kienböck's disease observed in patients with cerebral palsy strongly suggests that repeated minor trauma together with negative ulnar variance is also the cause of Kienböck's disease in normal individuals.

Adolescent↗

PubMed1993

Clinical aspects of primary thyroid lymphoma: diagnosis and treatment based on our experience of 119 cases.

We describe the clinical aspects of primary thyroid lymphoma, particularly diagnostic procedures and successful therapy based on our observation of 119 patients with primary thyroid lymphoma. Thyroid lymphoma occurred exclusively in the thyroid gland of patients with Hashimoto's thyroiditis as a rapidly growing mass in the thyroid gland. Therefore, progressively enlarging goiter and compression symptoms were the most common clinical manifestations. A significant number of patients in our series had subclinical hypothyroidism (14%) or overt hypothyroidism (27%) because of the coexistence of Hashimoto's thyroiditis. Whenever thyroid lymphoma is suspected, we recommend an ultrasound scan of the thyroid gland and fine needle aspiration biopsy as initial diagnostic procedures. Thyroid ultrasound showed characteristic asymmetrical pseudocystic pattern in 43 of the 46 patients (93%), and thyroid cytologic examination showed abundant monomorphic infiltration of lymphoid cells. Among 83 patients who underwent fine needle aspiration biopsy, 65 patients (78.3%) were diagnosed correctly and 10 patients (12%) had borderline cytologic results. Thus, 90% of patients with thyroid lymphoma were diagnosed or the diagnosis suspected based on fine needle aspiration biopsy. To confirm the diagnosis of lymphoma histologically and to determine the degree of malignancy, open biopsy taking 2-3 g tissue should be done for all cases. Treatment of thyroid lymphoma does not require resection of all lymphoma tissue or total thyroidectomy. Our successful treatment is radiation therapy combined with six courses of CHOP chemotherapy (cyclophosphamide, adriamycin, vincristine, prednisolone). This mode of therapy improved the 8-year survival rate to nearly 100% regardless of the histological type of malignancy.

Adult↗

PubMed1993

Site-directed mutagenesis of the putative active site residues of 3C proteinase of coxsackievirus B3: evidence of a functional relationship with trypsin-like serine proteinases.

Picornavirus 3C proteinases (3Cpro) are cysteine proteinases but recent sequence analyses have shown that they are related to trypsin-like serine proteinases. Two models of 3Cpro structure have been presented. Both models indicate that residues His40 and Cys147 are members of the catalytic triad but the models differ in the designation of the third member of the catalytic triad, which is assigned as either Glu71 or Asp85. To test the importance of these four residues in the catalytic activity of 3Cpro of coxsackievirus B3, a member of the enterovirus subgroup of the picornavirus family, single amino acid substitutions were introduced at each of the four sites. All of these mutations resulted in the reduction or inactivation of autocatalytic cleavage of the 3C precursor protein expressed in Escherichia coli, suggesting that all of these residues are essential for the proteolytic reaction. The substitution of Cys147 with Ala abolished 3Cpro activity while the mutant in which Cys147 was replaced with Ser retained reduced proteolytic activity both in cis and in trans. Our results strongly support the proposal that Cys147 of 3Cpro functions as a nucleophile analogous to Ser195 of trypsin-like serine proteinases.

3C Viral Proteases↗

PubMed1993

Comparison of the alpha-toxin genes of Clostridium perfringens type A and C strains: evidence for extragenic regulation of transcription.

The Clostridium perfringens plc gene encoding phospholipase C (alpha-toxin) was cloned from type C NCIB 10662, a strain which produces low levels of phospholipase C activity. The nucleotide sequence of a cloned 3.1-kb HindIII fragment was determined. The same fragment was also cloned from type A NCTC 8237, a phospholipase C-overproducing strain. In this case, an open reading frame (ORF2) truncated in the previously cloned 2-kb fragment was also sequenced. Comparison of the nucleotide sequence between the 3.1-kb fragments of the two type strains shows some differences both in the plc gene and in ORF2. However, when the 3.1-kb fragment was cloned into plasmid pUC19 and expressed in Escherichia coli, the plc genes from both type strains were similarly expressed and the toxins produced showed similar levels of activity. Northern blot analysis revealed that the type A strain produced 16 to 23 times more plc mRNA than the type C strain. These results indicate that in C. perfringens the two plc genes are transcribed at different rates, probably because of a difference in a locus lying outside of the cloned fragments. Gel retardation analysis showed that the type A strain possessed two different proteins that bound different regions of the plc gene. However, one of these proteins, which binds within the plc coding region, was not found in the type C strain, suggesting that it plays a role in the regulation of the plc gene expression.

Amino Acid Sequence↗

PubMed1993

Detection of Theileria sergenti infection in cattle by polymerase chain reaction amplification of parasite-specific DNA.

A pair of synthetic oligonucleotide primers, designed from the gene encoding a 32-kDa intraerythrocytic piroplasm surface protein of Theileria sergenti, were used to amplify parasite DNA from the blood of T. sergenti-infected cattle by means of the polymerase chain reaction (PCR). PCR-amplified DNA was examined by electrophoresis and by dot blot or microplate hybridization using a parasite-specific cDNA probe. PCR was specific for T. sergenti, since no amplification was detected with DNA from Anaplasma centrale, Babesia ovata, uninfected erythrocytes, and leukocytes. This method was sensitive enough to detect about 4.5 parasites per microliters of blood with a 10-microliters sample volume. Moreover, of 66 specimens from grazing cattle, 40 were microscopically positive, whereas PCR revealed that 54 samples were positive. Therefore, PCR provides a useful diagnostic tool for detecting T. sergenti-infected cattle, and it is significantly more sensitive than the current methods.

Animals↗

PubMed1993

Inhibition of IgE-mediated leukotriene generation and bronchoconstriction in primates with a new 5-lipoxygenase inhibitor, E6080.

The inhibitory effects of a novel compound, 6-hydroxy-2-(4-sulfamoylbenzylamino)-4,5,7-trimethylbenzothiazo le hydrochloride (E6080) on IgE-mediated reactions in vitro and in vivo were determined in rhesus monkeys. E6080 inhibited both antigen- and anti-human IgE-induced leukotriene C4 generations from lung fragments at similar concentrations: the IC50s of E6080 were 1.11 and 0.96 microM, respectively. AA861 also inhibited both leukotriene C4 generations with IC50s of 0.79 and 0.76 microM, respectively. All 9 monkeys demonstrating positive cutaneous reactivity against Ascaris antigen at < 10(-7) g protein/0.1 ml showed reproducible bronchoconstriction upon aerosolized antigen challenge, but 5 monkeys demonstrating weak or no reactivity to the antigen at levels > 10(-5) g protein/0.1 ml showed no significant bronchoconstriction. The high responder monkeys showed a marked increase in lung resistance (RL 335.3 +/- 85.3%, n = 11) and a decrease in dynamic lung compliance (67.7 +/- 4.2%, n = 11) after antigen challenge following pretreatment with diphenhydramine. These pulmonary changes lasted for more than 30 min. E6080 at oral doses of 3 and 10 mg/kg showed dose-dependent inhibition of both pulmonary changes. Ten milligrams per kilogram of E6080, administered 1.5 h prior to antigen challenge, significantly inhibited the changes in both parameters, while 3 mg/kg showed significant inhibition of only the RL change. These results demonstrate that E6080 inhibited immunologically stimulated leukotriene production in the lung, resulting in inhibition of the antigen-induced airway response in primates.

Animals↗

PubMed1993

Thyroid histology of hyperthyroid Graves' disease with undetectable thyrotropin receptor antibodies.

To determine the histological characteristics of hyperthyroid Graves' disease with undetectable TSH receptor antibodies (TRAb), we examined the thyroid histological findings of patients with hyperthyroidism who were referred for subtotal thyroidectomy and who lacked circulatory TRAb. Four patients had undetectable TRAb (6.4 +/- 4.2%) before treatment (group A). Their pathological and clinical findings were compared with those of four patients who had hyperthyroid Graves' disease with detectable TRAb (83.8 +/- 8.3%) before treatment (group B). The groups were matched for sex, age, duration of antithyroidal drug therapy, anti-Tg antibody, and antimicrosomal antibody levels. All patients were in a euthyroid state just before operation. Papillate hyperplastic epithelia in group A were significantly less severe than in group B. Enlarged colloids were not observed in two of the four patients in group A but were observed in all four patients in group B. Moderate or marked lymphocytic infiltrations were observed in all patients in group A but were virtually absent in group B. Based on these results, it is probable that hyperthyroid Graves' disease with undetectable TRAb titers represents an early stage or subtype of usual hyperthyroid Graves' disease in which there is marked or moderate lymphocytic infiltration.

Adolescent↗

PubMed1993

Activation of temperature-dependent flagellar movement of demembranated fowl spermatozoa: involvement of an endogenous serine protease.

In the presence of ATP, the motility of demembranated fowl spermatozoa was vigorous at 30 degrees C, but negligible at 40 degrees C. Motility could be restored at 40 degrees C by the addition of 10-100 ng trypsin ml-1. Chymotrypsin also stimulated the motility, but neither papain nor carboxypeptidase B appreciably affected motility. Conversely, at 30 degrees C sperm motility was inhibited by aprotinin or phenylmethylsulfonyl fluoride. These results suggest that endogenous protease, presumably serine protease, activity is instrumental in the regulation of fowl sperm motility. It seems likely that the site of action of this protease is axonemal, but a direct effect of added protease on dynein ATPase activity could not be demonstrated.

Adenosine Triphosphatases↗