Biomedical subjects

H Fujioka

Publications and source records attributed to H Fujioka.

At least 163 records · Page 9Linked to original sources

PubMed1997

[Renal cell carcinoma in a horseshoe kidney: a case report].

A 69-year-old man presented for further examination for left renal mass. Computed tomography and magnetic resonance imaging revealed a heterogenous mass on the left side of a horseshoe kidney accompanied with renal vein thrombus. Aortography showed a hypervascular mass in the left kidney and aberrant arteries to the isthmus originating from the aorta. A left nephrectomy with the division of the isthmus was performed through an abdominal transperitoneal approach. Histological evaluation revealed grade 2, stage T3b, renal cell carcinoma. The patient was free of tumor, but died of intracerebral hemorrhage 5 months after the operation.

Aged↗

PubMed1997

[Compton-scatter correction using the triple energy window (TEW) method in conventional single photon emission computed tomography without TEW acquisition hardware].

We devised a method which allowed the triple energy window (TEW) method to be applied for Compton-scatter correction in conventional single photon emission computed tomography (SPECT) systems without any hardware for TEW acquisition. In this method, the data within two subwindows located at both sides of the main window were acquired together. The effectiveness of this method was investigated by phantom experiments. The integral and differential uniformities measured using a flood phantom filled with 123I were minimized when the energy width of subwindows was 5 keV (5.8% and 4.2%, respectively). When this method was applied to a brain phantom filled with 123I in which the relative activities in white and gray matter were assigned as 1: 4.3, the ratio of SPECT values between them was more accurate (1:4.26) than that obtained without this method (1:208). This method appears to be useful for Compton-scatter correction in SPECT, because it can be applied to conventional SPECT systems without any hardware for TEW acquisition and is available for routine clinical use for its simplicity.

Brain↗

PubMed1997

[Renal cell carcinoma associated with renal artery aneurysm].

We report the 5th case of renal cell carcinoma associated with renal artery aneurysm in the Japanese literature. A 57-year-old woman was admitted to our hospital for further examination of a right renal mass. Computerized tomography and magnetic resonance imaging revealed a 6 x 5 cm tumor at the upper pole of the right kidney and an aneurysm of the right renal artery. An angiography showed duplicated renal arteries and a saccular aneurysm 2.1 x 2.5 cm occurring at the first bifurcation of one renal artery. A transperitoneal radical nephrectomy was performed.

Aneurysm↗

PubMed1997

[A case of locally advanced squamous cell carcinoma in bladder diverticulum successfully treated by bladder-preserving therapy].

A 62-year-old man visited our hospital with asymptomatic gross hematuria. On cystoscopy, two diverticula were identified at the dome of the urinary bladder and one of them was packed with a tumor. Biopsy showed squamous cell carcinoma (SCC), G1, but malignancy was not detected in the rest of the vesical mucosa. We selected bladder-preserving therapy. Pathological diagnosis after partial cystectomy was SCC, G1 > G2, pT3b. Postoperatively, 3 courses of adjuvant chemotherapy with methotrexate, bleomycin and cisplatin were performed. The patient has remained free of recurrence for 4.5 years.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1997

[Mechanism mediating hypertension induced by chronic inhibition of nitric oxide synthesis].

Although the inhibition of nitric oxide (NO) synthesis is known to induce systemic hypertension, the underlying mechanisms mediating this type of hypertension are incompletely understood. In the present study we investigated the influence of sodium intake on the pressor effect of long-term administration of the NO synthesis inhibitor, NG-nitro-L-arginine methyl ester (L-NAME, 16 mg/dl in drinking fluid for 8 weeks), in conscious Sprague-Dawley rats. Urinary excretion rates of catecholamine during NO synthesis inhibition were also examined. Long-term administration of L-NAME produced a sustained elevation in tail-cuff pressure without altering urine flow, or sodium excretion rate. L-NAME-induced hypertension was accompanied by a decreased urinary excretion of the stable NO metabolites, NO2- and NO3-, and was aggravated when rats drank 0.9% saline in place of tap water. Thus, inhibition of NO synthesis resulted in a rightward shift of the pressure natriuresis relationship and a significant decrease in the slope of this relationship. Urinary excretion of epinephrine and norepinephrine, but not that of dopamine, in L-NAME-treated rats significantly increased within the first week of the study when compared with those observed in control rats. A natriuretic index of the sympathetic nervous system, the ratio of dopamine to norepinephrine excretion, was significantly less in L-NAME-treated rats than in control rats. After 8-week treatment with L-NAME, renal morphologic evaluation revealed significant narrowing and obliteration of the arterioles. L-arginine (2 g/dl in drinking fluid) completely reversed the elevation of blood pressure as well as the decrease in urinary NO2- and NO3- excretion and the increased urinary excretion of catecholamines associated with L-NAME treatment after 3 weeks of concomitant administration. These results suggest that the inhibition of chronic NO synthesis produces sodium-sensitive hypertension and that changes in sympathetic nerve activity may, at least in part, contribute to the sodium sensitivity in this type of hypertension.

Animals↗

PubMed1997

[A randomized study on intravesical pirarubicin (THP) chemoprophylaxis of recurrence after transurethral resection of superficial bladder cancer].

A prospective randomized study was conducted to evaluate the efficacy of prophylactic intravesical instillation of tetrahydropyranyladriamycin (THP) following complete transurethral resection (TUR) of superficial bladder cancer. A total of 80 patients were randomized into "THP" or "control" group. In the THP group, 20 mg of THP dissolved in 40 ml saline (or 5% dextrose) was administered intravesically once a week for 10 weeks, starting from about 7 days after TUR. In the control group, 40 ml saline was given with the same schedule. The patients were followed up by cystoscopy and urinary cytology every 3 months. The number of evaluable patients was 36 for the THP group and 37 for the control group. The non-recurrence rates in the THP group and control group were 79.4% versus 63.2% at 1 year and 69.8% versus 47.4% at 3 to 5 years, respectively. These figures were not statistically significant. However, THP instillation significantly reduced tumor recurrence rates for multiple tumors, and also tended to decrease recurrence rates for primary and pT1 tumors. Adverse effects were observed in 53.6% of the patients in the THP group, but they were tolerable. Our results suggest that intravesical THP instillation would not be effective for all patients with superficial bladder cancer. Further study is warranted in a selected group of patients.

Administration, Intravesical↗

PubMed1996

The molecular basis of pathogenesis of cerebral malaria.

Explore the source record for details and available documents.

Animals↗

PubMed1996

A mouse model for cerebral babesiosis.

Clinical symptoms and pathology observed in the cattle infected with Babesia bovis are quite similar to those of human cerebral malaria. Mechanisms involved in the pathogenesis of cerebral babesiosis, however, are still poorly understood because of the lack of a suitable experimental animal model. In this report, Masayoshi Tsuji and his colleagues describe B. bovis infection in severe combined immunodeficiency (SCID) mice, whose circulating red blood cells (RBCs) have been substituted with bovine RBCs (Bo-RBC-SCID mice). The infected mice not only develop a substantial level of parasitemia, but also show nerve symptoms and pathology similar to those observed in infected cattle.

Journal Article↗

PubMed1996

Stage-specific processing of Pfs230, a Plasmodium falciparum transmission-blocking vaccine candidate.

During Plasmodium falciparum gametocytogenesis, Pfs230, a malaria transmission-blocking vaccine candidate, is expressed as a 360 kDa protein localized to the parasitophorous vacuole/parasite plasma membrane. When gametocytes emerge from red blood cells, as they do when taken up in a blood meal by a mosquito, Pfs230 is processed from a 360 kDa form to a 310 kDa form the latter of which is exposed on the exterior surface of gametes. The 50 kDa portion of Pfs230, removed from the amino-terminus of the 360 kDa form, contains 25 contiguous glutamates and an EEVG16 repeat. Analogous to other P. falciparum proteins, the repeat region appears to be immunodominant. As the gamete emerges from the red blood cell and is exposed to the antibodies in the blood meal, cleavage of the immunodominant region of Pfs230 may contribute to an immune evasion strategy by the parasite.

Amino Acid Sequence↗

PubMed1996

Somatosensory evoked potentials recorded from the posterior pharynx to stimulation of the median nerve and cauda equina.

Somatosensory evoked potentials (ppSEPs) in response to stimulation of the median nerve at the wrist and the cauda equina at the epidural space (the L4 level) were recorded from the posterior wall of the pharynx in 15 patients who underwent spinal surgery under general anesthesia, using disc electrodes attached to the endotracheal tube, and compared with segmental spinal cord potentials (seg-SCPs) that were recorded simultaneously from the posterior epidural space (PES). ppSEPs consisted of the initially positive spike (P9) followed by slow positive (P13) and negative (N22) waves. The P13 and N22 of ppSEPs had phase reversal relationship with the P2 and N2 recorded from the PES, respectively. The peak latencies of P9 (9.40 +/- 0.7 ms) (mean +/- SD), P13 (13.1 +/- 0.9 ms), and N22 (22.0 +/- 2.1 ms) of ppSEPs coincided with those of P1, N1 and P2 of seg-SCPs, respectively, ppSEPs were recorded more clearly with a reference electrode on the dorsal surface of the neck than with the reference electrode at the earlobe or back of the hand. The threshold and maximal stimulus intensities were also similar between the ppSEPs and seg-SCPs. Thus, the P9, P13, and N22 components of ppSEPs were thought to have the same origin as the P1, N1 and P2 of seg-SCPs, respectively. Therefore, the P9, P13 and N22 of ppSEPs may reflect incoming volleys through the root, synchronized activities of the interneurons and primary afferent depolarizations (PAD), respectively. ppSEPs in response to cauda equina stimulation showed that the latencies of the two initial components (4.6 +/- 0.4 and 6.4 +/- 0.6 ms) corresponded to those of the SCPs recorded from the PES (4.6 +/- 0.3 and 6.3 +/- 0.5 ms), suggesting that these potentials reflect impulses conducting through the spinal cord, similar to epidurally recorded SCPs.

Adult↗

PubMed1996

A developmental defect in Plasmodium falciparum male gametogenesis.

Asexually replicating populations of Plasmodium parasites, including those from cloned lines, generate both male and female gametes to complete the malaria life cycle through the mosquito. The generation of these sexual forms begins with the induction of gametocytes from haploid asexual stage parasites in the blood of the vertebrate host. The molecular processes that govern the differentiation and development of the sexual forms are largely unknown. Here we describe a defect that affects the development of competent male gametocytes from a mutant clone of P. falciparum (Dd2). Comparison of the Dd2 clone to the predecessor clone from which it was derived (W2'82) shows that the defect is a mutation that arose during the long-term cultivation of asexual stages in vitro. Light and electron microscopic images, and indirect immunofluorescence assays with male-specific anti-alpha-tubulin II antibodies, indicate a global disruption of male development at the gametocyte level with at least a 70-90% reduction in the proportion of mature male gametocytes by the Dd2 clone relative to W2'82. A high prevalence of abnormal gametocyte forms, frequently containing multiple and unusually large vacuoles, is associated with the defect. The reduced production of mature male gametocytes may reflect a problem in processes that commit a gametocyte to male development or a progressive attrition of viable male gametocytes during maturation. The defect is genetically linked to an almost complete absence of male gamete production and of infectivity to mosquitoes. This is the first sex-specific developmental mutation identified and characterized in Plasmodium.

Animals↗

PubMed1996

Seroprevalence and specificity of human responses to the Plasmodium falciparum rhoptry protein Rhop-3 determined by using a C-terminal recombinant protein.

Rhoptry proteins participate in invasion of erythrocytes by malaria parasites. Antibodies to some of these proteins can inhibit invasion and partially protect monkeys from disease. To examine human serological responses to the 110-kDa component (Rhop-3) of the high-molecular-weight rhoptry protein complex, two cDNA clones corresponding to Rhop-3 were identified by immunologic screening. A recombinant protein representing the C-terminal one-third of the Rhop-3 was used to assess the seroprevalence to this protein in geographically isolated populations with different patterns of malaria transmission. The immunoglobulin G (IgG) positivity rate for the recombinant Rhop-3 in an enzyme-linked immunosorbent assay was 30% in an area of Papua New Guinea where malaria is holoendemic. In Kenya, the prevalence rates were 43 and 36%, respectively, in an area of hyperendemicity and an area of seasonal transmission. By contrast, rates of IgG seroprevalence to an extract of Gambian strain of Plasmodium falciparum were 48, 90, and 97% respectively, in these populations. In these areas, the pattern of antibody recognition of Rhop-3 is more similar (1.7-fold maximum difference) than the parasite extract (5-fold difference). The difference in seroresponses may represent antigenic polymorphism in different parasite strains, while their similarity for the Rhop-3 fragment may represent conservation of this protein. Recombinant- and parasite extract-specific IgG was not found in individuals infected only with Plasmodium vivax. Cross-reactivity was seen in the IgM assay. In Mombasa (Kenya), maternal and cord Rhop-3-specific IgG activities were similar. Fetal antigen-specific IgM reactivity was generally undetectable for all antigens.

Animals↗

PubMed1996

Antineutrophil cytoplasmic antibodies (ANCA)-associated crescentic glomerulonephritis and propylthiouracil therapy.

Cutaneous vasculitis is an uncommon complication of propylthiouracil therapy. Although its pathogenesis remains to be established, detection of antineutrophil cytoplasmic antibodies (ANCA) in association with this type of vasculitis has recently been described. We report here 2 patients who developed ANCA-associated crescentic glomerulonephritis without evidence of cutaneous vasculitis during propylthiouracil treatment of hyperthyroidism. Improvement of the renal function and the disappearance of ANCA were correlately found after discontinuation of propylthiouracil and by corticosteroid therapy in both patients.

Adult↗

PubMed1996

Release profiles of recombinant human tumor necrosis factor from Ca(2+)-triggering liposome in vivo.

After the administration of the recombinant human tumor necrosis factor (rHuTNF), plasma concentration could be controlled from egg yolk phosphatidylcholine (eggPC)-egg yolk phosphatidic acid (eggPA) liposome (EggPA liposome). The plasma concentration was highest after the rHuTNF solution administration. Although the concentration after the 30% EggPA liposome administration was much lower than that after the solution administration, the antitumor effect against Meth A sarcoma was equal to that of the rHuTNF solution. Non-linear elimination of rHuTNF in rat could explain these phenomena. First, to evaluate the intact absorption profile, we developed a non-linear absorption calculating program (NLAP). The calculation revealed little difference in the total absorption amounts between the solution and liposomes. The absorption rate from the liposomes was lower than that from the solution, and finally, the control of rHuTNF release from liposomes was also confirmed in vivo. These findings suggested that the sustained release of rHuTNF from liposomes maintained high drug concentration in the injected site and decreased the systemic drug concentration.

Animals↗

PubMed1996

Differential contribution of metal complexation and dimerization to the chemotherapeutic potential of bicyclen-Zn2II complex against human immunodeficiency virus.

1,1'-(m-Xylenediyl)-bis(1,4,7,10-tetraazacyclododecane)-Z n2II complex (m-xylenediyl-bicyclin-Zn2II), a potent inhibitor of human immunodeficiency virus (HIV), was obtained from cyclin by a combination of dimerization and metal complexation. The ratio of median cytotoxic concentration against host cells (CC50) and median effective concentration against HIV cytopathogenicity (EC50), referred to as the selectivity index (SI), was regarded to be a measure of anti-HIV activity. These two chemical modifications contributed to a potent, in vitro anti-HIV activity of m-xylenediyl-bicyclin-Zn2II by respectively increasing the CC50 and decreasing the EC50 in comparison with those of cyclin.

Antiviral Agents↗

PubMed1996

Ameloblastoma with prominent ossification in the mandible of a dog.

A rare case of ameloblastoma with prominent stromal ossification in an 8-year-old female dog was studied. A bony mass recurred rapidly in the right mandible at the first molar region. Histopathologic examination revealed the lesion to be an atypical variant of ameloblastoma. Epithelial cells showed marked cell atypia, and mitotic figures were rather common. The collagenous stroma was abundant, with prominent formation of bone trabecular rimmed by active osteoblasts. The tumor was highly proliferative and aggressive, and thought to be malignant in nature.

Ameloblastoma↗

PubMed1996

Effect of low dietary calcium intake on blood pressure and pressure natriuresis response in rats: a possible role of the renin-angiotensin system.

Dietary Ca is an important modulator of blood pressure in humans and rats. Since the kidney plays a key role in the pathogenesis of hypertension, the effects of a low Ca diet (0.01% Ca) on blood pressure and pressure natriuresis response were studied in normotensive Sprague-Dawley rats. In addition, a possible role of the renin-angiotensin system in the development of hypertension and an altered pressure natriuresis response resulting from low dietary Ca intake was examined. In the low Ca diet group, systolic blood pressure measured by the tail-cuff method was significantly higher than in the normal Ca diet group (1,1% Ca) 1 week after the diet (1 13.0 +/- 7.1 vs. 105.0 +/- 9.5mmHg, p < 0.05). After 4 weeks, the hypertension was more pronounced. Low dietary Ca intake significantly inhibited the water and sodium excretory responses to acute elevation of renal perfusion pressure by tightening an infrarenal aortic constriction. Treatment with an inhibitor of angiotensin-converting enzyme, captopril (30 mg/kg/day), completely abolished the elevation of blood pressure and attenuated the reduced pressure natriuresis response observed in Ca-deficient rats. Although plasma renin activity was not different between the low and normal Ca diet groups after the 2-week dietary regimen, the pressor response to angiotensin II was enhanced by 30% in the low Ca diet group and there was a significant difference in the pressor response between the two groups. These results suggest a possible involvement of the renin-angiotensin system in the development of hypertension and an inhibitory effect on the pressure natriuresis response caused by low dietary Ca intake, via an enhanced sensitivity to angiotensin II.

Analysis of Variance↗

PubMed1996

A correlation of the sequestration rate of Plasmodium coatneyi-infected erythrocytes in cerebral and subcutaneous tissues of a rhesus monkey.

Parasitized red blood cells (PRBCs) were sequestered in microvessels of cerebral and subcutaneous tissues of a rhesus monkey infected with Plasmodium coatneyi. A similar sequestration rate (approximately 80%) was observed in both cerebral and subcutaneous microvessels. Electron microscopy showed knobs of the sequestrated PRBCs cytoadhered to endothelial cells. These results are consistent with the finding of PRBC sequestration in subcutaneous tissues in a comatose patient with cerebral malaria. Biopsy specimens of subcutaneous tissue may be useful as indicators of PRBC sequestration in the brain of cerebral malaria patients.

Animals↗