Search PubMed⌕ Search

Biomedical subjects

S Aoki

Publications and source records attributed to S Aoki.

At least 199 records · Page 11Linked to original sources
PubMed1998

Effect of pirarubicin for elderly patients with malignant lymphoma.

To determine the effect of a chemotherapy regimen containing pirarubicin, a multicenter clinical trial was performed in naive patients > or = 65 years with malignant lymphoma, between January 1990 and December 1992. The total number of patients was 37 (median age 74.2 years). One of three different types of chemotherapy regimens, which was administered every 3 to 5 weeks, was chosen for each patient at random. Regimen A (THP-COP) included pirarubicin (30 mg/m2; day 1), cyclophosphamide (500 mg/m2; day 1), vincristine (1 mg/m2; day 1) and prednisolone (30 mg/m2; days 1-5), regimen B, modified "CHOP", included doxorubicin (30 mg/m2; day 1), cyclophosphamide (500 mg/m2; day 1) vincristine (1 mg/m2; day 1) and prednisolone (30 mg/m2; days 1-5); regimen C (THP-COPE) included etoposide (80 mg/m2; day 1) in addition to regimen A. The complete response (CR) rate was 60.0%, 45.5% and 62.5% with regimen A, B and C. The partial response (PR) rate with regimen A was 20.0%, 18.2% with B and 25.0% with C. The 50% survival period with regimen A was more than 1,000 days, with C 643 days but it was only 365 days with B. The adverse effects related to these treatments occurred more frequently in regimen B than A and C showing a statistically significant difference. We concluded that chemotherapy regimens containing pirarubicin are useful and safe for the elderly patients with malignant lymphoma.

Aged↗
PubMed1998

[Intracranial aneurysms in autosomal dominant polycystic kidney disease detected by MR angiography: screening and treatment].

The association of intracranial aneurysm with ADPKD is well-known, and patients with ADPKD are at increased risk of subarachnoid hemorrhage from rupture of intracranial aneurysms. We prospectively performed three-dimensional time-of-flight magnetic resonance angiography (MRA) in 30 nonselective adult patients with ADPKD. Sixteen were women and 14 were men with a mean age of 51 yr (range 24 to 79 yr). The diagnosis of ADPKD was made on the basis of abdominal ultrasound or computed tomographic studies. Three patients were on maintenance hemodialysis, 8 patients were nondialysed patients with chronic renal failure (serum creatinine > or = mg/dl) and 25 patients had hypertension (BP > or = 140/90 mmHg). None of these patients have a previous diagnosis of intracranial aneurysm. Unruptured intracranial aneurysms were suspected in 5 patients by MRA, and 8 aneurysms were confirmed in 4 (13.3%) of 30 patients by conventional arteriography. These aneurysms were 3 approximately 10 mm in diameter and 3 aneurysms (3 approximately 4 mm in diameter) were newly detected by cerebral arteriography. After informed consent was obtained, neck clipping of the intracranial aneurysms were performed successfully in all the patients. These results suggest that the prevalence of intracranial aneurysms is about 13% in ADPKD, and that MRA is useful in screening for occult intracranial aneurysms in patients with ADPKD.

Adult↗
PubMed1998

Velocity-coded color MR angiography.

We developed a method of velocity-coded color MR angiography using a color code from the data obtained from velocity-phase images of phase-contrast MR angiography in order to add flow direction information to MR angiograms. Phase-contrast MR angiography with reconstruction of velocity-phase images was performed in 30 patients. Two projection images from velocity-phase images of each phase-contrast MR angiogram were obtained and assigned color according to flow direction. We then superimposed the two color images onto the maximum intensity projection image of the MR angiogram. The velocity-coded color MR angiogram clearly showed flow direction from the data on the phase-contrast MR angiogram of the neck. Veins were readily distinguishable from arteries, and flow changes, such as a subclavian steal, were also identified.

Blood Flow Velocity↗
PubMed1998

[Pituitary enlargement in spontaneous intracranial hypotension on MRI].

PURPOSE: To examine whether the pituitary gland enlarges in patients with spontaneous intracranial hypotension (SIH). MATERIALS AND METHODS: All six patients were women ranging in age from 17 to 51 years. They developed severe headache that was completely relieved by lying flat, and MR imaging showed diffuse enhancement of the pachymeninx. They were clinically diagnosed with SIH. The height of the pituitary gland was measured on midsagittal MR image. RESULTS: Pituitary heights ranged from 8 to 11 mm. The measurements were greater than the size of the normal pituitary gland in women described age-matched in the previous report. In one case, follow-up MR images showed that the size of the pituitary gland was decreased from 11 to 5 mm in height. CONCLUSION: The pituitary gland was enlarged in all six patients with SIH on MR images. SIH may cause enlarged pituitary gland.

Adolescent↗
PubMed1998

Quantitative analysis of nonuniform distributions in lung perfusion scintigraphy.

UNLABELLED: Nonuniform distributions of lung perfusion scintiscans obtained by SPECT were quantified to supplement qualitative lung scintiscans. A total of 126 lung perfusion scintigraphy examinations were performed between February and December 1996 on a subject population of 102 patients, including 8 control subjects. All of the subjects were broadly classified according to whether they had pulmonary disease or nonpulmonary disease. The latter group was subdivided into a group with cardiac disease and other diseases. The grade of breathlessness was classified according to whether oxygen inhalation was required, the clinical severity of the breathlessness and patient's performance status. Blood gas analysis was performed in 21 cases, and pulmonary function testing was performed in 26 cases. METHODS: With the subjects resting in the supine position, 185 MBq 99mTc-macroaggregate albumin was infused. From reconstructed SPECT images, the volume of lung as a whole calculated at 10% of threshold was assumed to be the functional lung volume, and the functional volume rates were calculated in 10% threshold widths from 10% to 100% of thresholds. Assuming the total absolute difference in functional volume rate between each subject and the control to be the distribution index of the lung as a whole (D index), we quantified the degree of nonuniform distribution in each subject. RESULTS: The D index of all subjects ranged from 2.7 to 72.2. The mean D index in pulmonary disease was significantly higher than in nonpulmonary disease (p < 0.0005) and cardiac disease (p < 0.005). It was significantly positively correlated with the grade of breathlessness, significantly negatively correlated with the oxygenation index and significantly positively correlated with measured vital capacity and forced expiratory volume in 1 sec as percentages of their predicted values. CONCLUSION: The D index is a useful indicator for quantifying nonuniform distributions on lung scintiscans. If it is used as a supplement to qualitative interpretation of scintiscans, pulmonary perfusion scintigraphy will become a more useful technique for clinical evaluation of treatment and assessment of breathlessness and respiratory failure than the usual one.

Aged↗
PubMed1998

Expression patterns of costimulatory molecules on cells derived from human hematological malignancies.

In order to elucidate the possibility of costimulatory molecules-mediated immuno or immuno-gene therapy for human hematological malignancies, we analyzed 30 hematopoietic cell lines and cells obtained from 48 patients with hematological malignancies for the expression of costimulatory molecules such as CD80 and CD86. The 30 hematopoietic cell lines were composed of 4 cell lines derived from the patients with T-cell acute lymphoblastic leukemia (T-ALL), 3 from Philadelphia chromosome positive ALL (Ph1+ALL), 8 from acute myeloblastic leukemia (AML), 3 from acute promyelocytic leukemia (APL), 8 from chronic myeloid leukemia at blast crisis (CML-BC), 3 from Burkitt's lymphoma and one from follicular cell lymphoma. The expression of CD80 or CD86 was frequent on cell lines derived from the patients with CML-BC or Burkitt's lymphoma, while it was rare on cell lines from T-ALL. Subsequently we analyzed the cells obtained from 48 patients with hematological malignancies, which consisted of 6 samples from patients with ALL, 30 from AML, 2 from CML-BC, 3 from B-cell lymphoma and one from each acute mixed leukemia (AMixL), adult T cell leukemia (ATL), T-cell large granular lymphocytic leukemia (T-LGL leukemia), chronic lymphocytic leukemia (CLL), myelodysplastic syndrome (MDS)-RAEB in T, multiple myeloma (MM) or T-cell lymphoma. Among all the 48 cases, all cases except one case with CLL and two with B cell lymphoma were demonstrated to be negative for CD80 on the neoplastic cells. CD86 and HLA-DR were shown to be expressed in 50% and 88% of total 48 cases respectively. In 30 AML samples, CD86 was positive in 15 cases (50%), which was sharply in contrast with the finding that CD80 was not detected in any AML samples. HLA-DR was expressed in 25 AML samples (83%). We also treated seven human hematopoietic cell lines with IFN-gamma, IL-12 or IL-15 and observed whether these cytokines could induce or enhance the expression of CD40, CD54, CD58 and HLA-DR as well as CD80 and CD86. The present study demonstrated that the expression of CD86 could be upregulated not only by IFN-gamma, but also by IL-12 or IL-15 in some cell lines. These findings suggested the possibility that the absence of CD80 on neoplastic cells may be associated with the lack of efficient anti-tumor immunity in most patients with hematological malignancies and that the immuno or immuno-gene therapy manipulating the expression of costimulatory molecules such as CD80 may be a useful treatment modality for hematological malignancies.

Adult↗
PubMed1997

Activation of Met tyrosine kinase by hepatocyte growth factor is essential for internal organogenesis in Xenopus embryo.

Hepatocyte growth factor (HGF) specifically activates Met tyrosine kinase receptor, leading to mitogenic, motogenic, and morphogenic responses in a wide variety of cells. To know a role of HGF in Xenopus embryogenesis, loss-of-function mutation was introduced by dominant expression of truncated tyrosine kinase-negative Met. When tyrosine kinase-negative Met mRNA was micro-injected into two-cell to eight-cell stages Xenopus embryos, the liver development was mostly impaired and structures of pronephros and the gut were grossly underdeveloped in the restricted, late stage of development. These results strongly suggest that functional coupling between HGF and Met is essential for the development of internal organs originated from primitive gut and possibly involved in embryonic skeletogenesis. Together with developmental abnormality in mice mutated with HGF or Met gene, essential role of HGF for liver development is highly conserved from amphibian to mammalian species.

Animals↗
PubMed1997

Circadian rhythms in rapidly dividing cyanobacteria.

The long-standing supposition that the biological clock cannot function in cells that divide more rapidly than the circadian cycle was investigated. During exponential growth in which the generation time was 10 hours, the profile of bioluminescence from a reporter strain of the cyanobacterium Synechococcus (species PCC 7942) matched a model based on the assumption that cells proliferate exponentially and the bioluminescence of each cell oscillates in a cosine fashion. Some messenger RNAs showed a circadian rhythm in abundance during continuous exponential growth with a doubling time of 5 to 6 hours. Thus, the cyanobacterial circadian clock functions in cells that divide three or more times during one circadian cycle.

Cell Division↗
PubMed1997

Xenopus LIM motif-containing protein kinase, Xlimk1, is expressed in the developing head structure of the embryo.

The LIM double zinc finger motif locates in several developmentally functioning and cytoskeletal proteins, and is considered to act as a specific motif for protein-protein interactions. LIM kinase (LIMK) is a novel protein kinase containing two LIM motifs at the N-terminal, the function of which has yet to be clearly defined. In this study, we cloned a cDNA encoding Xenopus counterpart of human LIMK1 gene by RT-PCR mediated cloning, and designated in Xlimk1. Xlimk1 is highly homologous to mammalian LIMK1 in each structural domain, particularly in LIM and protein kinase domains. In Northern blot analysis, two distinct Xlimk1 transcripts of 9.0 Kb and 3.7 Kb were present in early cleavage stages of the embryo. Both mRNA species were subsequently decreased at the gastrula stages. The 9.0 Kb of Xlimk1 mRNA again appeared in late neurula stage, then the expression level gradually increased in later stages of the embryo. Whole-mount in situ hybridization analysis showed the localization of Xlimk1 transcripts in the animal half of the blastula embryo. In post-neurula stages, specific signals for Xlimk1 were predominant in the anterior (head) region of the embryo, including developing brain, hyoid and branchial arches, and anlagen of sensory organs. These results indicate that Xlimk1 may play an important role in neural development and formation of anterior (head) structures in the Xenopus embryo.

Amino Acid Sequence↗
PubMed1997

Effect of albendazole on recurrent and residual alveolar echinococcosis of the liver after surgery.

Patients with alveolar echinococcosis of the liver (AEL) can be cured by complete excision of the lesions; however, it is not always completely resectable in advanced cases. Recently, benzimidazole-type drugs have been reported to be effective in nonresectable AEL. One hundred fifty-two patients with AEL have been surgically treated in our institution since 1937. Our clinical trial with albendazole, one of the benzimidazole carbamates, has included 26 cases of AE since September 1988, each of whom had undergone an operation. Complete resection was performed in only six cases. Evaluation of response to the treatment was possible in 20 cases. A favorable response to albendazole, such as decreases in the size of the lesions, changes in cyst morphology, and amelioration in clinical symptoms or signs, was achieved in 11 (55%) cases. These favorable responses were also seen in cases of noncurative resection and palliative operation. The cumulative survival rate of the patients was 87%, 15 years after the operation. A complete response was achieved in one case; the residual lesion in the liver completely disappeared on the computed tomography image 3.5 years after noncurative surgery. Palliative or mass reduction surgery combined with albendazole therapy may be a strategy for advanced disease, especially when complete resection might result in significant morbidity or mortality.

Adult↗
PubMed1997

Technical report: coaxial catheter: a new technique for sequential spiral CT during arterial portography and hepatic arteriography.

PURPOSE: To evaluate a coaxial catheter method to sequentially acquire spiral-computed tomography (CT) during arterial portography (CTAP) and hepatic arteriography (CTA) at a single transfer. PATIENTS AND METHODS: Sixteen patients with malignant hepatic tumours (12 patients with hepatocellular carcinoma, four with metastases) were studied using spiral CT. Depending upon the vascular anatomy revealed by conventional coeliac and superior mesenteric arteriography, an outer and inner catheter were selectively placed to perform CTA and CTAP, respectively. CTAP images were obtained first, while injecting contrast material through an inner catheter followed by the acquisition of the CTA images during injection through an outer catheter. In three patients, the resected specimens were available for comparison with the imaging findings. RESULTS: In 12 patients with standard hepatic arterial anatomy, high quality images of CTAP and CTA were obtained. More lesions were detected by the combination of CTAP and CTA than by CTAP or CTA alone in five patients. In one patient with breast carcinoma and a left hepatic artery arising from the left gastric artery, numerous hepatic metastases were delineated on both sets of images. In three patients with replaced or accessory right hepatic arteries, evaluation of the whole liver was difficult on CTA. These procedures were well tolerated by all 16 patients and no complication or technical failure was experienced. CONCLUSION: These preliminary data support this new technique as a promising method of performing CTA and CTAP in patients with standard hepatic arterial anatomy with a single catheter insertion.

Aged↗
PubMed1997

Neuroendocrine control of diapause hormone secretion in the silkworm, Bombyx mori.

To clarify the control mechanism of diapause hormone (DH) secretion in the silkworm Bombyx mori a series of anatomical and pharmacological experiments were carried out. The arrangement of 'diapause' and 'non-diapause' eggs in the ovarioles of the moths was determined by the coloration method to estimate the accumulation of 3-hydroxykynurenine in the eggs. The females destined to lay non-diapause eggs (non-diapause producers) had diapause eggs in their ovaries if their subesophageal ganglions (Sg) had been surgically removed at 2days after larval-pupal ecdysis or later. In contrast when the surgical extirpation extended to the brain and the corpora cardiaca (CC)-corpora allata (CA) complex in addition to the Sg, the non-diapause producers had no diapause eggs. When the Sg was removed from the females destined to lay diapause eggs (diapause-producers), diapause eggs appeared in response to the treatment at 2days after larval-pupal ecdysis, but the appearance of diapause eggs was delayed by 2days when the brain-CC-CA complex was included among the organs removed. These observations suggested that DH is produced in Sg and transferred to the CC-CA complex, and that the secretion of DH from the complex is suppressed in non-diapause producers. The pattern of diapause and non-diapause eggs induced by the transection of the subesophageal connective in diapause and non-diapause producers suggested a regenerative and secretory capacity of the neurosecretory cells after the operation. The appearance of diapause eggs in non-diapause producers with transected protocerebrum of the brain confirmed that there was an inhibitory center in the protocerebrum. Changes in parts of the ovarioles containing diapause and non-diapause eggs with time of injection of gamma-aminobutyric acid (GABA) and picrotoxin suggested that a GABAergic inhibitory mechanism in DH secretion may be active in non-diapause producers but inactive in diapause producers throughout the pupal stage.

Journal Article↗
PubMed1997

Inhibitory effects of various spasmolytics on the vagal afferent gastric excitatory response in cats.

The inhibitory effects of atropine, cimetropium, pirenzepine and N-butylscopolamine on the vagal afferent gastric excitatory response in cats under anesthesia with pentobarbital sodium and infusion of gallamine were examined. Electrical stimulation of vagal trunk in left side (10 Hz in frequency, 3 msec in duration, 15 V in intensity and for 10 sec) caused an initial gastric excitatory response during the period of stimulation followed by a late excitatory gastric response after stimulation in normal cats. The initial response was inhibited by atropine (100 microg/kg, i.v.) and hexamethonium (10 mg/kg, i.v.), while the late response was inhibited by atropine but not by hexamethonium (10 mg/kg, i.v.). In chronic supranodose vagotomized cats 11-15 days after the operation, stimulation of the vagal trunk caused a late gastric excitatory response after the stimulation period, which was inhibited by atropine (100 microg/kg, i.v.) but not by hexamethonium (10 mg/kg, i.v.). The two types of gastric responses in normal cats have been defined as follows: the initial gastric excitatory response (atropine- and hexamethonium- sensitive) is due to activation of vagal efferent fibers and the late gastric excitatory response (atropine-sensitive and hexamethonium-resistant) is due to activation of vagal afferent fibers. ED50 values of atropine, cimetropium, pirenzepine and N-butylscopolamine in inhibiting the vagal afferent gastric response were 7.2 microg/kg (n=4), 2.4 microg/kg (n=6), 82.6 microg/kg (n=3) and 93.0 microg/kg (n=4), respectively. The inhibitory effects of atropine and cimetropium on the vagal afferent gastric excitatory response (hexamethonium-resistant) were more potent than those of pirenzepine and N-butylscopolamine. These results suggested that the potent inhibitory effects of cimetropium and atropine on the vagal afferent gastric response may involve a potent spasmolytic effect.

Animals↗
PubMed1997

Acute toxicity, accumulation and excretion of organophosphorous insecticides and their oxidation products in killifish.

Acute toxicity, accumulation and excretion of four organophosphorous insecticides (diazinon, malathion, fenitrothion and EPN) and their oxidation products (diazinon oxon, malaoxon, fenitrothion oxon and EPN oxon) were studied for killifish (Oryzias latipes). The 48-hr LC50 was 4.4 mg l-1 for diazinon, 1.8 mg l-1 for malathion, 3.5 mg l-1 for fenitrothion, 0.58 mg l-1 for EPN, 0.22 mg l-1 for diazinon oxon, 0.28 mg l-1 for malaoxon, 6.8 mg l-1 for fenitrothion oxon, and 0.16 mg l-1 for EPN oxon. The bioconcentration factors (BCF) of diazinon oxon 0.5, malaoxon 1.1, fenitrothion oxon 2.3 and EPN oxon 11 in the whole body of the fish were much lower than those of diazinon 49, malathion 11, fenitrothion 122 and EPN 1124. As reference data, partition coefficients between n-octanol and water (Pow) were measured for these chemicals. The BCF values of each pesticide and its oxidation product were consistent with the Pow values. The excretion rate constants (k) from the whole body of the fish were 0.12 hr-1 for diazinon, 0.27 hr-1 for malathion, 0.11 hr-1 for fenitrothion, 0.02 hr-1 for EPN, 0.30 hr-1 for fenitrothion oxon and 0.59 hr-1 for EPN oxon. The rates of diazinon oxon and malaoxon could not be measured, but were presumed to be as rapid as or more rapid than those of fenitrothion oxon and EPN oxon. The results suggest that the contamination of fish and other aquatic organisms by the oxidation products in the environment is very low.

1-Octanol↗