Biomedical subjects

A Hyodo

Publications and source records attributed to A Hyodo.

At least 55 records · Page 3Linked to original sources

PubMed1995

Early endovascular treatment for ruptured basilar bifurcation aneurysm--case report.

A 69-year-old male presented with sudden onset of headache. Computed tomography of the head demonstrated diffuse subarachnoid hemorrhage. Angiography showed a saccular basilar bifurcation aneurysm. Endovascular coil occlusion of the aneurysm on the same day enabled complete obliteration of the aneurysm. He did not develop vasospasm and returned home 4 months later. Early endovascular occlusion of the aneurysmal sac is an alternative method for the management of ruptured basilar bifurcation aneurysms.

Aged↗

PubMed1995

Effects of tazobactam on the frequency of the emergence of resistant strains from Enterobacter cloacae, Citrobacter freundii, and Proteus vulgaris (beta-lactamase derepressed mutants).

When Enterobacter cloacae, Citrobacter freundii, and Proteus vulgaris were treated with piperacillin (PIPC) in combination with tazobactam (TAZ), the in vitro frequency of emergence of resistant strains (beta-lactamase producing mutants) was lower than with PIPC or ceftazidime (CAZ) treated bacteria. In a mouse intraperitoneal infection model caused by E. cloacae, beta-lactamase derepressed mutants were detected following therapy with PIPC or CAZ, although no derepressed mutants were detected after treatment with PIPC in combination with TAZ. This suppression of the selection of derepressed mutants, which produce large amounts of beta-lactamases, by the combination of TAZ and PIPC suggests that the combination delays the increase of resistant mutants compared with PIPC alone.

Animals↗

PubMed1995

Chemical modification of tazobactam. Synthesis of 2 beta-[(4-substituted)-1,2,3-triazol-1-yl]methyl penicillanic acid sulfone derivatives.

A series of 2 beta-[(4-substituted)-1,2,3-triazol-1-yl] methyl penicillanic acid sulfones was synthesized as beta-lactamase inhibitors. Many of these compounds showed good in vitro inhibitory activity against penicillinase, cefotaximase and plasmid-mediated class III TEM enzymes, but exhibited weaker cephalosporinase inhibition. One member in this series--2 beta-[(4-pyridiniummethyl)-1,2,3-triazol- 1-yl]-6,6-dihydropenicillanate 1,1-dioxide (12a), when tested in combination with piperacillin, showed excellent synergistic activity against microorganisms producing plasmid-mediated enzymes, but had insufficient activity against microorganisms producing chromosomally mediated class I enzymes.

Ampicillin↗

PubMed1995

Characterization of a new plasmid-mediated extended-spectrum beta-lactamase from Serratia marcescens.

A new extended spectrum beta-lactamase was detected in Serratia marcescens 42039 that was isolated from urine of patients with complicated urinary tract infection in Japan. This stain produced three different beta-lactamase types (TEM-1, a cephalosporinase, and a new beta-lactamase: CKH-1). The TEM-1 and CKH-1 encoding genes were conjugated from S. marcescens 42039 to Escherichia coli K-12 at frequencies of 10(-5) to 10(-6). The MICs of beta-lactams against the transconjugant were: ampicillin > 1600, piperacillin 800, cephalothin 1600, ceftazidime 6.25, cefotaxime 100, and ceftriaxone 200 micrograms/ml. The CKH-1 enzyme was purified to more than 90% by ion-exchange chromatography. The molecular weight of purified CKH-1 was 30 K dalton and the isoelectric point was 8.2. Relative Vmax/Km values (cephaloridine = 100) of penicillin G, cephalothin, and oxyiminocephalosporins such as cefuroxime, ceftriaxone, and cefotaxime, were 256, 226, 116, 87, and 49, respectively. The I50 values of tazobactam, BRL-42715, and clavulanic acid against CKH-1 enzyme were 0.0011, 0.0002, and 0.097 microM respectively. The enzymatic activity of CKH-1 was not inhibited by EDTA and anti-TEM-1 serum. These findings indicate that CKH-1 is a member of the groups of class A beta-lactamases. This is the first report of a plasmid-mediated oxyiminocephalosporin hydrolyzing broad-spectrum beta-lactamase from clinical isolates of S. marcescens.

Anti-Bacterial Agents↗

PubMed1995

[Electrophysiologic evaluation of entrapment neuropathy caused by scar formation in recurrent motor branch of the median nerve].

A unique case of mononeuropathy was encountered in a 20-year-old man with isolated involvement of the recurrent motor branch of the right median nerve following a skiing accident one year previously. There was also isolated involvement of the right thenar muscles innervated by the median nerve. Sensation was intact in the right hand and fingers. Conventional conduction studies in the right median nerve yielded no abnormal findings except a reduction in the amplitude of the muscle action potential. However, insertion of a needle electrode into the abductor pollicis brevis muscle revealed some delayed motor unit potentials following electrical stimulation at the wrist. We performed surgery and found the right recurrent motor branch to be entrapped by fibrous scar tissue 3 to 4 mm distal to branching from the median nerve. Direct recordings made from the nerve trunk using a tungsten microelectrode with supramaximal stimulation at the elbow revealed reduced amplitude of the compound nerve action potential distal to the site of entrapment. We concluded that scar tissue resulting from the previous injury had compressed the recurrent motor branch, causing this unique neuropathy.

Adult↗

PubMed1995

Nuclear characterization and G2M ploidy in human brain tumors using semiautomated image analysis.

We used image analysis to study nuclear morphometry and DNA content in relation to time to tumor progression in a series of 88 patients with brain tumors. Clinical follow-up was obtained for 73 patients. The patients with diploid tumors had a longer time to tumor progression than those with triploid, tetraploid, or hypertetraploid tumors. Mean SG2M-DNA indices (DIs) increased significantly with a increase in mean DIs in all tumors. The mean DIs appeared to be dependent on the number of SG2M phase cells. We conclude that tumors with hypertetraploid in G2M ploidy are highly malignant. Those tumor cells have a large nuclear size, much deformity in nuclear shape, and great proliferative potential. The G2M-tetraploid tumors showed a shorter time to tumor progression when the number of SG2M fractions was large. In contrast, the G2M-hypotetraploid tumors showed a longer time to tumor progression in comparison with other tetraploid and hypertetraploid tumors, but the difference was not significant.

Aneuploidy↗

PubMed1994

Evaluation of human bone morphogenetic protein 2 in a canine spinal fusion model.

The efficacy of purified recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered in a porous biodegradable copolymer, poly [D,L (lactide--coglycide)] (PLGA) was evaluated using a canine posterior segmental spinal fusion model. rhBMP-2/PLGA was compared to autogenous cancellous bone and to PLGA alone. Thirty three fusion sites in 11 beagle dogs were evaluated at 12 weeks for union and mechanical strength. Union score and mechanical testing showed no difference between autogenous cancellous bone and rhBMP-2/PLGA. Union scores for autogenous cancellous bone and rhBMP-2/PLGA sites were superior to those with PLGA alone (p = 0.001 and p = 0.0007, respectively). These findings suggest that synthetic bone graft substitute materials delivering purified rhBMP-2 may be suitable for posterior spinal fusions. The use of such materials may provide efficacy equivalent to autogenous cancellous bone and avoid the morbidity associated with the harvest of autogenous graft.

Animals↗

PubMed1994

Experimental induction of arthritis in rats immunized with Escherichia coli 0:14 lipopolysaccharide.

OBJECTIVE: Escherichia coli 0:14 (E. coli 0:14) induces arthritis in rabbits, mice and rats. This study was designed to investigate the effects of lipopolysaccharide (LPS) on the rat arthritis model induced by systemic injections of E. coli 0:14. METHODS: The induction of arthritis in the ankles of rats immunized by subcutaneous injections with heat-killed E. coli 0:14 and its LPS was studied. The appearance and levels of serum IgM rheumatoid factor-like substance (RFLS) was also investigated. The localization of interleukin 1 (IL-1) and LPS in the ankle joints were investigated immunohistochemically. RESULTS: The induction rate of arthritis in rats immunized with LPS was the same as that in rats immunized with E. coli. LPS and IL-1 were detected in synovial cells, infiltrating cells and some cells on pannus in arthritic joints. Anti-LPS IgM levels in rats immunized with E. coli were as high as those in rats immunized with LPS. RFLS levels in rats immunized with LPS increased more gradually than those in rats immunized with E. coli. CONCLUSION: Our findings suggest that LPS induces arthritis resembling rheumatoid arthritis in rats. The detection of IL-1 in synovial cells in conjunction with LPS suggests that local stimulation of IL-1 production may play an important role in the induction of this experimental arthritis.

Animals↗

PubMed1994

[Surgical indication for unruptured cerebral aneurysm in patients with ischemic cerebrovascular disease].

A series of 44 cases is presented of patients who received surgical treatment for unruptured aneurysms in the anterior circulation, and which were associated with ischemic cerebrovascular disease (CVD). The age of patients varied from 34 to 76 (mean 62.8) years old. The associated ischemic CVD was transient ischemic attack (TIA) in ten, minor completed stroke in 23, and major completed stroke in 11 cases. Thirty five patients recovered fully. However, there were three deaths due to new cerebral infarction or delayed intracranial hemorrhage within 30 days after surgery (mortality 6.8%). Transient morbidity occurred in four patients (9.1%), and permanent morbidity in two patients (4.5%). In six cases, new ischemic events occurred after the surgery. In contrast, all 40 patients whose unruptured aneurysms were not associated with CVD fully recovered from the surgery they underwent. The authors indicate three risk factors which might lead to complication; diabetes mellitus, aneurysms located in the middle cerebral artery, and those larger than 6mm in diameter. Another three life-threatening factors are; elderly patients (> 65 year-old), male, aneurysms larger than 7mm in diameter. Direct surgery for unruptured aneurysms in ischemic CVD patients should be considered in cases free of risk factors indicated above. Eight cases in this series had extracranial carotid artery stenosis on the same side as the aneurysm. Carotid endoarterectomy (CEA) was performed prior to aneurysmal clipping in six patients, and their postoperative courses were excellent. In two patients, clipping was performed prior to CEA, and transient morbidity occurred in one of them.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

[Management for subarachnoid hemorrhage with negative initial angiography].

Subarachnoid hemorrhage (SAH) is commonly caused by ruptured aneurysm or arteriovenous malformation which is detected by cerebral angiogram. However, since angiograms sometimes cannot show the origin of SAH, we review 12 cases (6.3% of total SAH) to assess the management of these cases. We divided the 12 cases into three groups. Group A (occulted aneurysm group) consisted of six cases of which aneurysms were detected by repeated angiographies in four, and by surgical procedures in two. Group U (unknown etiology group) consisted of five cases. Their follow up periods varied from 7 months to 7 years 11 months, and all of them recovered well and had no episode of rebleeding. Group R (rebleeding group) consisted of one case which fatally re-bled on the second day. Group A tended to be Hunt and Hess grade 3, and Fisher group 3 or 4. In contrast, group U tended to be H and H grade 1 or 2, and Fisher group 2. However by their clinical and neuroradiological findings alone, it was not possible to distinguish the two groups certainly. This means that the patients whose initial angiography does not show the origin of bleeding must be cared for as an occult aneurysm case. Twice repeated angiograms should be programmed. In our cases the first was carried out on the seventh day in the hope that the reason for vasospasm of the parent artery might be shown to be a hidden aneurysm. The second was carried out sometime between the 14th and 21st day because of thrombolysis in the aneurysm, and because it was necessary to relieve vasospasm.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

The role of thallium-201 single photon emission tomography in the investigation and characterisation of brain tumours in man and their response to treatment.

The aim of this study was to characterise brain tumour type and treatment response in relation to the uptake of thallium-201. 201T1 single photon emission tomography (SPET) was performed in 58 patients with brain tumours. Fifty-six patients were utilised for the statistical comparison of the early and delayed 201T1 indices expressed as the ratio of tumour to contralateral cerebral hemisphere uptake. The retention index of 201T1 in the tumour tissue calculated from the early and delayed scans was also analysed. Furthermore, in 56 patients with 58 brain tumours, a comparison was made of the diagnostic value of high 201T1 uptake and gadolinium diethylene triamine penta-acetic acid (Gd-DTPA) enhancement on MRI scans. Although high 201T1 uptake was observed in viable malignant gliomas, brain metastases, meningiomas and malignant teratoma, the viable malignant gliomas could not be differentiated from brain metastases and extracerebral tumours by means of 201T1 indices. 201T1 SPET failed to diagnose a viable ring-enhanced tumour with a thin rim and small tumours of less than 1.5 cm in diameter visualised by Gd-DTPA-enhanced MRI. In spite of this, 201T1 SPET appears to be effective for determination of the malignant viability of tumours.

Brain↗

PubMed1993

Proton radiation therapy for clivus chordoma--case report.

A 57-year-old male with clival chordoma developed severe hoarseness, dysphagia, and dysphonia 1 month after a second removal of the tumor. Magnetic resonance imaging demonstrated a mass 10 cm in diameter in the region of the middle clivus enhanced inhomogeneously by gadolinium-diethylenetriaminepentaacetic acid, and a defect in the skull base. There was evidence of compression of the anterior surface of the pons. He received proton irradiation employing a pair of parallel opposed lateral proton beams. The dose aimed at the tumor mass was 75.5 Gy, to the pharyngeal wall less than 38 Gy, and to the anterior portion of the pons less than 30 Gy. Time dose and fractionation factor was calculated at 148. Thirty-one months following treatment, he was free of clinical neurological sequelae. Proton therapy should be considered in treatment planning following initial surgical removal or for inoperable clivus chordoma.

Chordoma↗

PubMed1993

[Therapeutic efficacy of cefodizime in combination with aminoglycosides against systemic infections caused by Pseudomonas aeruginosa in immunocompromised tumour bearing mice].

In vivo synergistic effects of cefodizime (CDZM) were investigated in combination with aminoglycosides (AGs), sisomicin (SISO) or dibekacin (DKB) against Pseudomonas aeruginosa in immunocompromised tumour bearing mice. Fractional effective dose (FED) indices showed that either synergistic or additive effects were observed between CDZM and AGs. The synergistic intraperitoneal bactericidal effect of CDZM in combination with SISO or DKB was also observed in immunocompromised tumour bearing mice. The post antibiotic effect (PAE) of AGs was prolonged by the addition of CDZM. Moreover, the strong synergistic bactericidal effects of CDZM and AGs against P. aeruginosa were observed in the presence of immunocompromised tumour bearing murine polymorphonuclear leukocytes (PMN). These results suggest that the strong therapeutic efficacy of CDZM in combination with AGs was caused by synergistic bactericidal effect of CDZM and AGs in the presence of PMN.

Animals↗

PubMed1993

[Therapeutic efficacy of cefodizime in combination with minocycline against systemic infection caused by methicillin-resistant Staphylococcus aureus in immunocompromised tumour bearing mice].

The in vivo synergistic effect of cefodizime (CDZM) in combination with minocycline (MINO) against methicillin-resistant Staphylococcus aureus (MRSA) was investigated. A study of fractional effective dose (FED) index showed that either synergistic or additive effect was observed between CDZM and MINO. The postantibiotic effect (PAE) of MINO was not altered by the addition of CDZM. However, a strong synergistic bactericidal effect of CDZM and MINO against MRSA CT-18 was observed for more than 14 hours in the presence of immunocompromised tumour bearing murine polymorphonuclear leukocytes (PMN). These results suggest that the strong therapeutic efficacy of CDZM in combination with MINO was caused by synergistic bactericidal effect of the 2 drugs in the presence of PMN.

Animals↗

PubMed1992

Malignancy and viability of intraparenchymal brain tumours: correlation between Gd-DTPA contrast MR images and proliferative potentials.

The feasibility of diagnosing the malignancy and viability of intraparenchymal brain tumours using Gd-DTPA, enhanced and unenhanced T1-weighted MRIs was investigated. The relationship between the Gd-DTPA enhancement pattern, the growth fraction (GF) determined by using the anti-bromide-oxyuridine (BrdU) monoclonal antibody, the clinical condition, the proliferative potential and the change of Gd-DTPA enhancement over time was studied. Forty-five patients with intracranial tumours were studied with the static method of Gd-DTPA MRI. The enhanced effect in Gd-DTPA MRIs was dependent on tumour-cell density, vascularization, necrosis, and dilatation of vascular lumen. Tumour-cells were observed in eighty-seven of eighty-nine specimens taken from areas with Gd-DTPA enhanced MRIs. Seventy-four percent of these specimens (64 of 87) showed a malignancy of more than 5% growth fraction. On the other hand, tumour cells were observed in twenty-seven of fifty-six specimens taken from areas with Gd-DTPA unenhanced MRIs. Eighty-five percent of these specimens (23 of 27) showed a malignancy value of less than 5% GF. However, fifteen percent of these specimen showed values between 5 and 15% GF. In the kinetic study of Gd-MRIs five patients who were in a clinically stable condition and one patient who had radionecrosis showed a constant pattern of enhancement or slightly increased enhancement 30 min after injection compared to 4 min after injection. Therefore, GD-DTPA MRI can be used effectively in the diagnosis of tumour viability and malignancy after treatment.

Brain↗

PubMed1992

Symptomatic cerebral vasospasm after intraventricular hemorrhage from ruptured arteriovenous malformation.

We present a rare case showing symptomatic vasospasm after intraventricular hemorrhage from a ruptured arteriovenous malformation. No significant subarachnoid hemorrhage in the basal cisterns was observed on computed tomography in the entire course of illness. Although most cases showing vasospasm are associated with the deposition of blood in the basal cisterns, this case suggests the possibility of some other important factor in causing the subsequent development of vasospasm.

Cerebral Hemorrhage↗

PubMed1992

Morphometrical analysis of GFAP-positive cells in human astrocytomas.

The morphometrical characteristics of human astrocytoma were examined using the shape, size, and intercellular distances of glial fibrillary acidic protein-positive cells in samples from 21 patients with various astrocytomas and normal samples resected during operations on seven patients with other brain tumors. The results showed that astrocytoma cells were rounder than normal astrocytes with fewer processes. Low-grade astrocytomas were smaller than astrocytes or rapid regrowth astrocytomas. Morphological analysis of astrocytoma may be valuable for evaluating the potential migration to adjacent tissue.

Adult↗

PubMed1992

Foramen magnum meningioma and arachnoid cyst coinciding in the lateral cerebellomedullary cistern--case report.

An extremely rare foramen magnum meningioma associated with an arachnoid cyst in the lateral cerebellomedullary cistern occurred in a 65-year-old female presenting with dizziness. Neuroimaging revealed a meningioma at the left lateral edge of the foramen magnum and an arachnoid cyst mainly located in the right lateral cerebellomedullary cistern, compressing the medulla oblongata bilaterally. After fenestration of the cyst wall and tumor removal, the clinical symptoms ameliorated. We recommend that where a foramen magnum tumor coexists with an arachnoid cyst of the posterior fossa, the tumor should be removed after shrinking the cyst to obviate the need for brainstem retraction.

Aged↗