Biomedical subjects

Y Hashimoto

Publications and source records attributed to Y Hashimoto.

At least 253 records · Page 14Linked to original sources

PubMed2000

[Malignant lymphoma at the cavernous sinus].

A 71-year-old man developed general fatigue, appetite loss, and headache. Two months later, he noticed diplopia. Examination demonstrated reduced visual acuity and complete ophthalmoplegia of the left eye. Brain MRI disclosed a mass that extended from bilateral cavernous sinus to the clivus. There were left cervical lymphadenopathy and a right abdominal mass. A needle biopsy of the abdominal mass revealed non-Hodgkin lymphoma. Although malignant lymphoma at the cavernous sinus is not common, it should be an important consideration in the differential diagnosis of mass at the cavernous sinus.

Aged↗

PubMed2000

Application of cis-2-amino-3,3-dimethyl-1-indanol as an efficient chiral auxiliary to the asymmetric Ireland-Claisen rearrangement. Improvement of the diastereoselectivity by combinational use of chlorodimethylsilane as a silylating agent

The asymmetric Ireland-Claisen rearrangement of allyl carboxylates having a chiral substituent at the alpha-position of the carboxylate part gave the desired products with excellent diastereoselectivity, when an oxazolidinone, which was prepared from a non-natural chiral auxiliary, (1R,2S)-cis-2-amino-3,3-dimethyl-l-indanol, was used as the chiral substituent. Furthermore, the diastereoselectivity was improved by using chlorodimethylsilane as a silylating agent of the intermediary enolates.

Journal Article↗

PubMed2000

[A case of angiosarcoma in retroperitoneal cavity].

We report a case of angiosarcoma in the retroperitoneal cavity. A 66-year-old man was admitted to our hospital with the complaint of chest discomfort. Imaging studies including computed tomography scan and magnetic resonance imaging revealed a large solid retroperitoneal mass adjacent to the bladder. There was no evidence of metastasis. The tumor was surgically resected and histopathologically diagnosed as angiosarcoma from the positive staining for VIIIth factor, mitotic figures and abnormal endothelial cells. Six months after surgery, local recurrence adjacent to the bladder appeared. We resected the mass and started adjuvant therapy using Interleukin-2. However, he died of progressed disease one year after the first operation.

Aged↗

PubMed2000

[Chronic encapsulated intracerebral hematoma in thalamus with incongruous right homonymous hemianopia: a case report].

We presented a patient with chronic encapsulated intracerebral hematoma. This 49-year-old woman suffered from visual disturbance, and slowly progressive right hemiparesis, sensory disturbance of the right extremities and incongruous right homonymous hemianopia over 2 months. Computed tomography scanning showed high density area and ring enhancement, and magnetic resonance imaging revealed mixed intensity on T1 and T2-weighted images in her left thalamus and internal capsule. Angiographic studies revealed no vascular anomaly or tumor stain. The pathologic pictures indicated well-encapsulated hematoma containing fresh and old hematomas in the left thalamus. Most reported cases of this disease had hematomas in the subcortex and no cases had similar visual disturbance. This report was prepared because this condition is uncommon and may remain unrecognized.

Cerebral Hemorrhage↗

PubMed2000

[Carotid artery disease in patients with retinal vein and artery occlusion].

To evaluate carotid artery disease in patients with retinal vein occlusion (RVO) and with retinal artery occlusion (RAO), 41 RVO patients (male 21, female 20, mean age 63 +/- 12 years) and 59 RAO patients (male 39, female 20, mean age 66 +/- 12 years) were investigated. All patients were examined neurologically and underwent carotid ultrasound examination. Using carotid ultrasound, carotid artery disease was evaluated in terms of presence of plaque, echogenicity of the plaque, degree of stenosis, or presence of ulceration. Carotid plaque or occlusion of the carotid artery was observed more frequently in RAO patients than in RVO patients (ipsilateral side: p < 0.01, contralateral side: p < 0.001; Fisher's exact test). Heterogeneous plaque was found more frequently in RAO patients compared to RVO patients (ipsilateral side: p < 0.01, contralateral side: p < 0.02; Fisher's exact test). Ulcerated plaque was found only in patients with RAO. In conclusion, carotid artery disease was more frequently found in patients with RAO than in patients with RVO.

Aged↗

PubMed2000

Trans-stimulation effects of folic acid derivatives on methotrexate transport by rat renal organic anion transporter, OAT-K1.

We examined the pharmacological role of the renal organic anion transporter OAT-K1, which localizes predominantly in the brush-border membranes of proximal straight tubules, in the urinary excretion of methotrexate and the possibility of its contribution to "folinic acid rescue." With Madin-Darby canine kidney (MDCK) cells stably transfected with OAT-K1 cDNA, OAT-K1-mediated methotrexate accumulation was inhibited in the presence of various folic acid derivatives. These derivatives included aminopterin, 5-methyltetrahydrofolic acid, unlabeled methotrexate, folinic acid (citrovorum factor, leucovorin), and folic acid with apparent inhibition constant values of 0.5, 1.2, 1.8, 8.2, and 14.1 microM, respectively. In contrast, 10 microM taurocholic acid and sulfobromophthalein did not inhibit OAT-K1-mediated methotrexate accumulation. In addition, methotrexate efflux was stimulated in the presence of inwardly directed gradients of aminopterin, 5-methyltetrahydrofolic acid, unlabeled methotrexate, folinic acid, and folic acid, but not of uric acid, taurocholic acid, and glutathione, indicating that OAT-K1-mediated methotrexate efflux is stimulated by a folic acid derivatives exchange. In conclusion, OAT-K1 was suggested to enhance the apical efflux of highly accumulated methotrexate in tubular epithelial cells and contribute at least in part to folinic acid rescue by exchanging intracellular methotrexate for extracellular folinic acid.

Aminopterin↗

PubMed2000

Determining the state of the deceased during cardiopulmonary resuscitation from tissue distribution patterns of intubation-related lidocaine.

The objective of this study was to determine whether the concentrations of lidocaine, used for endotracheal intubation, in body fluids and tissues reflect the state of the circulation of the deceased during cardiopulmonary resuscitation. The tissue distribution of lidocaine was investigated in seven individuals (Cases 1-7) who underwent medical treatment with endotracheal intubation using Xylocaine jelly (a 2% lidocaine hydrochloride preparation), before being pronounced dead. Six patients (Cases 1-6) had cardiopulmonary arrest on arrival at hospital. In Cases 1-4, there was no restoration of heartbeat during cardiopulmonary resuscitation. However, systemic distribution of intubation-related lidocaine was observed and the kidney-to-liver ratios of lidocaine were less than 1. In Cases 5 and 6, the heartbeat resumed temporarily with cardiac massage, and a kidney-to-liver lidocaine ratio greater than 1 was observed. In Case 7, where the patient was comatose upon admission to hospital, the kidney-to-liver ratio of lidocaine was also greater than 1. These phenomena were substantiated in animal experiments. Our results indicate that the absorption of tracheal lidocaine during the artificial circulation resulting from cardiopulmonary resuscitation results in a kidney to liver ratio of less than 1, whereas absorption during natural circulation gives a ratio greater than 1. The kidney-to-liver ratio of intubation-related lidocaine may give useful information on the state of a patient during cardiopulmonary resuscitation.

Absorption↗

PubMed2000

[Correlation between pyrimidine nucleoside phosphorylase (PyNPase) and clinicopathological factors in patients with gastric cancer].

Pyrimidine nucleoside phosphorylase (PyNPase) is a general term for enzymes which phosphorolyse pyrimidine class nucleosides; convert 5'-deoxy-5-fluorouridine (5'-DFUR), a fluoropyrimidine class anticancer drug, to an active type of 5-fluorouracil (5-FU); and demonstrate higher concentrations in tumor tissue. These findings have attracted attention from the standpoint of drug delivery systems. With regard to immunohistochemical staining studies, PyNPase expression correlated with cancer proliferation and metastasis. However, few have shown a relation between PyNPase assay and prognosis. We measured PyNPase value in tumor tissue of operative specimens from 60 gastric cancer patients. The results showed that the PyNPase value in tumor tissue was significantly higher (1.9 times) than in normal mucosa. There was no correlation between the PyNPase level in tumor tissue and clinicopathologic factors. However, many patients with relatively early gastric cancer had high enzyme levels, indicating that PyNPase may influence cancer proliferation and metastasis as well as prognosis. By detecting such a factor as PyNPase, and clinically applying the results, 5'-DFUR is promising for the treatment of patients with respect to prognosis.

Adult↗

PubMed2000

[A case of prostatic small cell carcinoma].

A 66-year-old man was referred to our hospital with a complaint of lumbago. Digital rectal examination showed an enlarged, irregular prostate with stony hardness. The serum level of prostate specific antigen (PSA) was elevated. Abdominal computed tomography showed enlarged common iliac and paraaortic lymph nodes, and multiple liver metastases. Bone scintigraphy showed multiple bone metastases. Histological and immunohistochemical examinations indicated small cell carcinoma and adenocarcinoma of the prostate. Chemotherapy could not be performed due to acute hepatic failure. The patient died 1 month after his first visit.

Adenocarcinoma↗

PubMed2000

Interaction and transport of thiazide diuretics, loop diuretics, and acetazolamide via rat renal organic anion transporter rOAT1.

The renal tubular secretion of thiazides and loop diuretics via the organic anion transport system in renal tubules is required for them to reach their principal sites of action. Similarly, acetazolamide, a diuretic clinically administered for glaucoma, is excreted from the kidney by glomerular filtration and tubular secretion. In this study, we investigated the interaction and transport of these diuretics via the rat renal organic anion transporter rOAT1 by using Xenopus laevis oocyte expression system. p-[(14)C]Aminohippurate (PAH) uptake by rOAT1-expressing oocytes was inhibited in the presence of a thiazide (chlorothiazide, cyclothiazide, hydrochlorothiazide), a loop diuretic (bumetanide, ethacrynic acid, furosemide), or a carbonic anhydrase inhibitor (acetazolamide, ethoxzolamide, methazolamide). Dixon plot analysis demonstrated that the inhibition constant (K(i)) value was 1.1 mM for acetazolamide, 150 microM for hydrochlorothiazide, 9.5 microM for furosemide, and 5. 5 microM for bumetanide. Kinetic analysis revealed that acetazolamide inhibited rOAT1 competitively and that inhibition style of furosemide was a mixture of competitive and noncompetitive. [(14)C]PAH efflux was significantly enhanced when the rOAT1-expressing oocytes were incubated in the presence of unlabeled PAH, alpha-ketoglutarate, acetazolamide, chlorothiazide, or hydrochlorothiazide. rOAT1 stimulated acetazolamide uptake, which was inhibited by probenecid. Although the loop diuretics had little trans-stimulation effect on [(14)C]PAH efflux via rOAT1, the rOAT1-mediated furosemide uptake was observed. These findings suggest that rOAT1 contributes, at least in part, to the renal tubular secretion of acetazolamide, thiazides, and loop diuretics.

Acetazolamide↗

PubMed2000

Secretory mechanisms of grepafloxacin and levofloxacin in the human intestinal cell line caco-2.

Grepafloxacin and levofloxacin transport by Caco-2 cell monolayers was examined to characterize the intestinal behavior of these quinolones. The levels of transcellular transport of [(14)C]grepafloxacin and [(14)C]levofloxacin from the basolateral to the apical side were greater than those in the opposite direction. The unidirectional transport was inhibited by the presence of excess unlabeled quinolones, accompanied by increased accumulation. The inhibitory effects of cyclosporin A plus grepafloxacin on basolateral-to-apical transcellular transport and cellular accumulation of [(14)C]grepafloxacin were comparable to those of cyclosporin A alone, indicating that the transport of grepafloxacin across the apical membrane was mainly mediated by P-glycoprotein. On the other hand, basolateral-to-apical transcellular transport of [(14)C]levofloxacin in the presence of cyclosporin A was decreased by unlabeled levofloxacin, grepafloxacin, and enoxacin, accompanied by significantly increased cellular accumulation. The organic cation cimetidine, organic anion p-aminohippurate, and the multidrug resistance-related protein (MRP) modulator probenecid did not affect the transcellular transport of [(14)C]grepafloxacin or [(14)C]levofloxacin in the presence of cyclosporin A. The basolateral-to-apical transcellular transport of levofloxacin in the presence of cyclosporin A showed concentration-dependent saturation with an apparent Michaelis constant of 5.6 mM. In conclusion, these results suggested that basolateral-to-apical flux of quinolones was mediated by P-glycoprotein and a specific transport system distinct from organic cation and anion transporters and MRP.

Anti-Infective Agents↗

PubMed2000

[Pitfall of postoperative right gastroepiploic artery angiogram].

Postoperative angiogram of the right gastroepiploic artery (RGEA) often revealed a complication as a 'string sign' or 'competition phenomenon'. Inadequate evaluation of the string sign or competition phenomenon was encountered in this study. In a 62-year-old male, an angiogram using a low-dose contrast medium showed a string sign of the RGEA, but a high-dose contrast medium demonstrated an adequate diameter of the RGEA with good flow. In a 68-year-old male, celiac artery angiograms showed the occlusion of the RGEA, although super selective angiograms indicated the RGEA to be patent. Adequate evaluation of the RGEA should include a super-selectiveangiograms.

Angiography↗

PubMed2000

[A case of femoral nerve palsy with malignant lymphoma].

A 52-year-old woman developed right inguinal mass in January, 1998. Biopsy of the mass revealed malignant lymphoma. Chemotherapies were done from February to May, and radiation therapies were done from November to December. She began to suffer from right femoral nerve palsy at the end of April, 1999. Pelvic MRI demonstrated small mass at right lower abdomen. Right abdominal mass became palpable in October, and we diagnosed as relapse of malignant lymphoma. Chemotherapy slightly relieved the femoral nerve palsy. Although mononeuropathy from malignant lymphoma is rare, we should take it into account in differential diagnosis of mononeuropathy.

Female↗

PubMed2000

[A case of distal posterior cerebral artery aneurysm associated with occlusion of the internal carotid artery].

Hemodynamic stress is considered one of the most important factors in the growth of cerebral aneurysms. The authors report a rare case of cerebral aneurysm located at the distal posterior cerebral artery (PCA) in which collateral circulation developed due to occlusion of the internal carotid artery (ICA). A 73-year-old male was admitted to our hospital with a sudden headache and nausea. Computerized tomography (CT) revealed an intracerebral hematoma in the right parieto-occipital lobe and the acute subdural hematoma in both the cerebral interhemispheric fissure and the convexity. Moreover, angiography revealed a saccular aneurysm at the P4 portion of the PCA. The right ICA was occluded at the cervical portion and collateral circulation which had developed in the PCA was extended to the region of the right middle cerebral artery. The aneurysm was clipped 15 days after admission without new neurological complications. This case demonstrates that increased hemodynamic stress plays a role in the growth and rupture of cerebral aneurysm.

Aged↗

PubMed2000

Combined peritoneal dialysis and hemodialysis therapy improves quality of life in end-stage renal disease patients.

The Dialysis Outcomes Quality Initiative (DOQI) guidelines recommend that, for patients on continuous ambulatory peritoneal dialysis (CAPD), a weekly creatinine clearance (WCC) of at least 60 L/1.73 m2 is needed for adequate dialysis. As residual renal function (RRF) declines, maintaining these target levels may become difficult. Over time, declines in ultrafiltration (UF) caused by increases in peritoneal permeability, in conjunction with decreases in RRF, may limit continuation of CAPD therapy. In an effort to achieve adequate solute clearance and ultrafiltration in several CAPD patients at our center who have declining RRF or poor UF, we use combined peritoneal dialysis and hemodialysis (PD + HD) as a therapeutic strategy when individualization of peritoneal dialysis is unsuccessful. At our center, PD + HD consists of five days of PD therapy followed by one HD session per week on Saturday. After the weekly HD session, patients are liberated from bag exchanges until Sunday evening. This PD + HD therapy was used in six cases where poor solute clearance and water retention were refractory to PD therapy alone. The combined therapy was well tolerated, and symptoms related to uremia improved in all six cases. Additionally, improvements in quality of life (QOL) were documented in all patients who were managed with the combined therapy. The improvements in QOL may have resulted from decreases in uremic symptomatology or freedom from bag exchanges. The PD + HD therapy can best be applied in the uremic PD patient without residual renal function whose peritoneal membrane is not deteriorated. The therapy allows for the continuation of PD without shifting to total HD in PD patients who continue to have uremic symptoms even after individualization of the PD prescription. Our patients readily accepted combined therapy, and we have noted excellent compliance with this therapy at our center.

Adult↗

PubMed2000

[Glioblastoma with a marked elevation of total protein and albumin in the cerebrospinal fluid].

We describe a patient with glioblastoma who showed very high levels of total protein and albumin in the cerebrospinal fluid. The patient was a 57-year-old man who underwent subtotal removal of a glioblastoma from the left temporal lobe. Two weeks after the operation, he had quadriplegia and a lumbar puncture was performed. The concentrations of total protein and albumin in the cerebrospinal fluid were 6000 mg/dl and 3600 mg/dl, respectively, which were more than 100 times higher than the upper limits of the reference ranges and were close to their serum levels. The magnetic resonance image suggested that these abnormal values were due to total spinal cord dissemination of the tumor. The results of the cerebrospinal fluid examination showed that the albumin concentration in the fluid might increase to the serum level and the prozone phenomenon should be kept in mind when measuring its concentration in the fluid.

Albumins↗

PubMed2000

[A noteworthy case of postoperative liver metastasis from gastric cancer which responded well to UFT therapy].

A 66-year-old male underwent partial gastrectomy (resection of the pyloric side of the stomach) at another hospital on the basis of a diagnosis of gastric cancer (Fig. 1). Five months later, his CEA level began to rise. At that time, multiple liver metastases were detected by ultrasonography and CT scans. The patient received oral UFT therapy (400 mg/day) at our hospital. A reduction in CEA was observed 63 days after the start of this therapy. A judgment of CR (complete response) was made after 4 months of the therapy. At present, 2 years and 4 months after UFT was first administered, the patient shows no signs of tumor recurrence. This case is noteworthy since there has been no previous report of a case where UFT showed a high efficacy in treating liver metastasis after surgical resection of gastric cancer.

Adenocarcinoma↗

PubMed2000

[Cerebral embolism in systemic lupus erythematosus with Libman-Sacks endocarditis: a case report].

We presented a patient of cerebral embolism caused by Libman-Sacks endocarditis with systemic lupus erythematosus (SLE). This 35-year-old housewife with SLE suffered from abrupt visual disturbance in December 1998. Angiography revealed the occlusion of her right posterior cerebral artery. Transesophageal echocardiography showed the mitral regurgitation and hyperplasia of the anterior mitral valve leaflet without vegetation. In April 1999, she again suffered from sudden onset of transient left hemiparesis and dysphasia. Angiographic findings were unchanged. Transesophageal echocardiographic examination detected vegetation on the anterior mitral valve leaflet and aggravation of the mitral regurgitation. Laboratory examination revealed inactivity of SLE. No bacteria was recovered from repeated blood cultures. We diagnosed that Libman-Sacks vegetation caused cerebral embolism.

Adult↗