Biomedical subjects

H Sakai

Publications and source records attributed to H Sakai.

At least 505 records · Page 28Linked to original sources

PubMed1996

A case of Sézary syndrome associated with cutaneous transformation.

Sézary syndrome is a leukemic variant in the spectrum of cutaneous T cell lymphomas. In some cases of cutaneous T cell lymphoma, the skin tumors or lymph nodes show morphologic changes indistinguishable from those of a large-cell lymphoma; this has been termed transformation. We report a case of Sézary syndrome who developed multiple skin tumors that showed transformation, loss of multiple pan T-cell markers (CD3, 4, 5, 7, 8), and a concomitant expression of CD30 during the course of the disease. Some of the tumors spontaneously regressed following incisional biopsy or traumatic wounds. The patient died of pneumonia five years following the transformation.

Antigens, CD7↗

PubMed1996

Satisfactory remission achieved by PUVA therapy in Langerhans cell hisiocytosis in an elderly patient.

Langerhans cell histiocytosis is currently regarded as a reactive proliferative process of Langerhans cells rather than a malignancy. The disease is characterized by Langerhans cell infiltration of skin, lung, bone and other organs. We report a 74-year-old man with Langerhans cell histiocytosis who had generalized hemorrhagic and crusted papules. He also had diabetes insipidus. Because he did not have any severe constitutional symptoms or failure of vital organs, we applied topical PUVA treatment to his skin lesions, which responded well to the therapy. Diabetes insipidus, however, remained, in spite of X ray radiotherapy for the pituitary lesion.

Aged↗

PubMed1996

Establishment and characterization of choroid plexus carcinoma cell lines: connection between choroid plexus and immune systems.

Murine choroid plexus cell lines were produced from choroid plexus carcinoma generated in transgenic mice harboring the viral oncogene simian virus 40 large tumor antigen under transcriptional control of an intronic enhancer region from the human immunoglobulin heavy chain (IgH) gene. Two morphologically distinct cell lines have been cloned. These established cell lines retained the characteristics of choroid plexus cells in that they expressed such choroid plexus cell marker or related proteins as transthyretin and alpha2-macroglobulin. They were tumorigenic in nude mice. In the cell lines, the muA and muB (HE2) motifs within the IgH intronic enhancer were active and we also demonstrated the existence of the proteins binding to these motifs, suggesting a potential link between the choroid plexus and immune systems. It is considered that these binding proteins act as trans-activators for the enhancer and may belong to the class of ETS-related proteins. These cell lines and xenografts should be useful materials for analyses of choroid plexus functions.

Animals↗

PubMed1996

Portal-systemic shunting in a patient with normal portal vain pressures and histological evidence of idiopathic portal hypertension.

Although idiopathic portal hypertension (IPH) is clinically characterized by portal hypertension and marked splenomegaly, we have experienced a case of spontaneous portal-systemic shunt without splenomegaly in whom the liver histology resembled IPH but with normal portal pressure. We admitted a 64 year old man who had suffered from hepatic encephalopathy for 2 years. Laparoscopy revealed a dark grey liver with a sharp edge and a concave surface. Examination of a liver biopsy specimen revealed peri-portal fibrosis consistent with IPH. A single, large, portal-systemic shunt was identified by percutaneous transhepatic portography. The shunt arose from the left gastric vein and flowed through the left renal vein into the inferior vena cava. No varices were identified. There were no morphological changes in the hepatic or portal veins. Portal vain pressure was normal. There was a slight difference between the portal pressure and the wedged hepatic vein pressure, suggesting a presinusoidal block. This case raises important questions concerning the aetiology of IPH and the relationship between portal hypertension and the development of collateral venous circulation.

Collateral Circulation↗

PubMed1996

Case report: primary splenic non-Hodgkin's B cell lymphoma in a patient with chronic hepatitis C.

A case of primary splenic lymphoma in a patient with chronic hepatitis C is reported. A 69-year-old man with chronic hepatitis C was admitted to Fukuoka City Hospital for evaluation of an enlarging splenic tumour. In the spleen, ultrasonographic examination revealed a hypoechoic tumour and computed tomography demonstrated a non-enhancing low density area measuring 7 cm in diameter; coeliac angiography revealed a hypovascular tumour. Gallium scintigraphy showed uptake of the radioisotope in the splenic tumour. A splenectomy was performed and the morphological and immunohistochemical findings of this tumour were compatible with those of non-Hodgin's B cell lymphoma. Recently, cases of malignant B cell lymphoma associated with hepatitis C virus infection have been reported. Lymphotropism of hepatitis C virus may play a pathological role in the development of non-Hodgkin's lymphoma. We emphasize the importance of considering lymphoma in the differential diagnosis of extrahepatic disorders during the course of chronic hepatitis C virus infections.

Aged↗

PubMed1996

Case report: intrahepatic cholangiocarcinoma with rhabdoid transformation.

Sarcomatous transformation is found in approximately 5% of patients with intrahepatic cholangiocarcinoma. According to previous reports, sarcomatous cholangiocarcinomas are composed of spindle-shaped cells and/or multinucleated giant cells. Usually, vimentin is expressed by these sarcomatoid cells. We report a case of intrahepatic cholangiocarcinoma with an element of rhabdoid cells that occurred in a 61-year-old woman admitted for back pain. Various imaging techniques demonstrated multiple liver masses. Histologically, these tumours formed in both sarcomatous and ordinary tubular adenocarcinomatous areas. The sarcomatoid areas were occupied mainly by loosely arranged, eosinophilic rhabdoid cells, which expressed both keratin and vimentin. These findings suggest that rhabdoid cells may occur in an undifferentiated stage of cholangiocarcinoma and possess a strong tendency to metastasize.

Bile Duct Neoplasms↗

PubMed1996

The mechanism of acidic pH-induced contraction in aortae from SHR and WKY rats enhanced by increasing blood pressure.

1. Effect of pH on vascular smooth muscle contraction was analyzed by use of biochemical and pharmacological techniques. 2. In the aorta isolated from spontaneously hypertensive rats (SHR) decreasing extracellular pH (pH0) caused a rapid acidification of intracellular pH accompanied by a pH0-dependent increase in tension. The contraction of the SHR aorta was remarkable compared with that of the Wistar Kyoto rat (WKY) aorta. 3. Removal of NH4Cl caused a transient decrease in intracellular pH followed by a marked increase in tension. 4. Both contraction and intracellular Ca2+ mobilization induced by acidic pH0 were markedly inhibited by removal of extracellular Ca2+, verapamil and adenosine, whereas these were not affected by tetrodotoxin or Gd3+, a stretch-activated cation channel blocker. Furthermore, cromakalim (a K+ channel opener) inhibited acidic pH0-induced contraction (APIC). 5. Acidic pH0 induced a depolarization of cultured smooth muscle cells from SHR aorta. 6. Blood pressure elevated with increasing age of WKY and SHR accompanied by an increase in APIC. Feeding WKY with NG-nitro-L-arginine, an inhibitor of nitric oxide synthases caused a marked elevation of their blood pressure followed by an increase in APIC. 7. These results suggest that APIC is caused by Ca2+ influx mediated through the activation of voltage-sensitive Ca2+ channels mainly due to acidic pH0-induced depolarization of the plasma membrane of smooth muscle cells. It is also suggested that APIC is strengthened by the elevation of blood pressure.

Acids↗

PubMed1996

A cyclic GMP-dependent housekeeping Cl- channel in rabbit gastric parietal cells activated by a vasodilator ecabapide.

1. The membrane potential of rabbit gastric parietal cells is dominated by a Cl- channel with a subpicosiemens single channel conductance in the basolateral membrane. The effects of 3-[[[2-(3,4-dimethoxyphenyl)ethyl]carbamoyl]amino-N-methylbenzamide++ + (DQ-2511: ecabapide), a vasodilator, on the opening of this Cl-1 channel, the cyclic GMP content and the intracellular free Ca2+ concentration ([Ca2+]i) of parietal cells were investigated by whole-cell patch-clamp technique, enzyme immunoassay and Fura 2-fluorescence measurement. 2. Ecabapide stimulated the opening of the Cl-1 channel as determined by the reversal potential. This stimulation was concentration-dependent, and its EC50 value was 0.2 microM. Both the basal and ecabapide-induced openings of the channel were inhibited by 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB, 500 microM), a Cl- channel blocker. Another Cl- channel blocker, niflumic acid (500 microM) was much less effective. 3. The power spectra of the currents before and after the addition of ecabapide (10 microM) were analysed. Both spectra contained only one Lorentzian (1/f2) component. 4. 6-Anilino-5,8-quinolinedione (LY83583; 5 microM) which prevents activation of soluble guanylate cyclase, significantly inhibited both the basal and ecabapide (10 microM)-induced openings of the Cl- channel. 5. Ecabapide (0.01-100 microM) concentration-dependently elevated the cyclic GMP content in the parietal cell-rich suspension. The EC50 value was 0.2 microM. 6. In single Fura 2-loaded parietal cells, ecabapide (10-100 microM) did not increase [Ca2+]i. 7. These results indicate that ecabapide stimulates an intracellular production of cyclic GMP in the parietal cell without increasing [Ca2+]i, and leads to an activation of the housekeeping Cl- channel.

Aminoquinolines↗

PubMed1996

Bilateral giant myelolipoma in the adrenal of a cotton-top tamarin (Saguinus oedipus).

A rare case of bilateral adrenal myelolipomas in a female cotton-top tamarin is reported. Large bilateral masses in the adrenal glands were composed of mature adipose cells containing varying amounts of hematopoietic cells of the myeloid, erythroid, and megakaryocytic series. The gross and histologic features of this case closely resemble human "giant" adrenal myelolipomas.

Adrenal Cortex↗

PubMed1996

Targeted mutagenesis of the human papillomavirus type 16 E2 transactivation domain reveals separable transcriptional activation and DNA replication functions.

The E2 gene products of papillomavirus play key roles in viral replication, both as regulators of viral transcription and as auxiliary factors that act with E1 in viral DNA replication. We have carried out a detailed structure-function analysis of conserved amino acids within the N-terminal domain of the human papillomavirus type 16 (HPV16) E2 protein. These mutants were tested for their transcriptional activation activities as well as transient DNA replication and E1 binding activities. Analysis of the stably expressed mutants revealed that the transcriptional activation and replication activities of HPV16 E2 could be dissociated. The 173A mutant was defective for the transcriptional activation function but retained wild-type DNA replication activity, whereas the E39A mutant wild-type transcriptional activation function but was defective in transient DNA replication assays. The E39A mutant was also defective for HPV16 E1 binding in vitro, suggesting that the ability of E2 protein to form a complex with E1 appears to be essential for its function as an auxiliary replication factor.

Amino Acid Sequence↗

PubMed1996

Effect of dobutamine of ventriculoarterial coupling in acute regional myocardial ischemia in dogs.

We assessed the effect of dobutamine on left ventricoarterial coupling during acute regional ischemia. Using a conductance catheter, we analyzed the end-systolic pressure-volume relation (ESPVR) in anesthetized dogs. We calculated the slope of ESPVR (Ees), the slope of the end-systolic pressure-stroke volume relation (Ea), (Ea/Ees) and the ratio (work efficiency) of external work to pressure-volume area at base-line during ischemia induced by occlusion of the left anterior descending coronary artery and during low-dose (1-3 micrograms.min-1.kg-1) and high-dose (4-10 micrograms.min-1.kg-1)dobutamine infusions with ischemia. ESPVR shifted to the right without a change in Ees during ischemia. Dobutamine caused dose-dependent increases in Ees but did not affect the intercept of ESPVR. During ischemia, Ea/Ees increased and work efficiency decreased. Low-dose dobutamine was associated with a return in control for Ea/Ees and work efficiency. High-dose dobutamine increased Ees and Ea but produced no further increase in Ea/Ees or work efficiency. Low-dose dobutamine would appear to be the preferable regimen to achieve the optimal ventriculoarterial coupling in acute regional ischemia associated with mismatched ventriculoarterial coupling and depressed left ventricular work efficiency.

Acute Disease↗

PubMed1996

Assignment of the human beta-microseminoprotein gene (MSMB) to chromosome 10q11.2.

Beta-microseminoprotein (MSP) is one of the major proteins secreted by the prostate, and its biological role in tumorigenesis of the prostate has been postulated. We assigned the human MSP gene (MSMB) to 10q11.2 with fluorescence in situ hybridization using a phage clone that has an MSP gene insert. Our mapping data shows that the gene is outside the previously identified LOH-regions (10p and 10q24-->qter) in prostate cancer cells and indicates that MSMB can be ruled out as a candidate for a tumor suppressor gene localized to those regions.

Base Sequence↗

PubMed1996

Involvement of interleukin-4 and soluble CD23 in hypersynthesis of immunoglobulins A and E in patients with IgA nephropathy.

To determine the cytokines responsible for the increase in production of IgA in patients with IgA nephropathy (IgAN), the roles of interleukin-4 (IL-4) and soluble CD23 (sCD23) were examined. Peripheral blood mononuclear cells (PBMCs) and serum were obtained from 24 patients with IgAN and 14 patients with non-IgA proliferative glomerulonephritis. Twenty healthy adults served as controls. Concentrations of IgA and IgE in 10-day culture supernatants of PBMCs were measured by the sandwich ELISA method. Levels of sCD23 and activities of IL-4 in 4-day (96-hour) culture supernatants and serum were measured by ELISA and bioassay, respectively. Activities of IL-4 both in culture supernatants and serum were significantly elevated in patients with IgAN compared with controls (1.26 +/- 0.53 vs. 0.68 +/- 0.37 U/ml in culture supernatants, p < 0.05; 1.35 +/- 1.34 vs. 0.89 +/- 0.82 U/ml in serum, p < 0.05). Levels of sCD23 in IgAN patients' serum were also significantly elevated (521.7 +/- 514.9 vs. 173.0 +/- 166.2 U/ml, p < 0.01). In vitro IgA and IgE synthesis were suppressed by anti-IL-4 monoclonal antibody (mAb) only when the antibody was added on the day when the culture was started (day 0). No suppression of IgA or IgE synthesis was observed when the antibody was added on day 4. IgE but not IgA synthesis was suppressed by anti-CD23 mAb when added on both days 0 and 4. Serum levels of IgE showed positive correlations with serum activities of IL-4 and with levels of serum sCD23. It is concluded that IL-4 and sCD23 might play decisive roles in in vitro and in vivo hyperproduction of IgA and IgE in patients with IgAN, and that sCD23 seemed to control IgE but not IgA synthesis through a unique pathway.

Adult↗

PubMed1996

Plasma glutathione peroxidase deficiency caused by renal dysfunction.

Glutathione peroxidase (GPx) activity was determined in the plasma of 118 healthy persons, 18 nondialyzed patients with chronic renal failure (CRF), 20 patients on maintenance hemodialysis (HD), and 58 patients on continuous ambulatory peritoneal dialysis (CAPD). Serum creatinine levels in the nondialyzed CRF patients revealed a highly significant negative correlation (r = -0.71, p < 0.001) with plasma GPx activity. Immunoblot analysis revealed that the plasma (extracellular) GPx protein was reduced or undetectable in patients with low plasma GPx activity. Plasma GPx activities in the HD and CAPD patients were reduced to 44 and 23% (female), and to 70 and 45% (male) of the sex-matched control values, respectively. In contrast, erythrocyte (cellular) GPx activity was not decreased in the nondialyzed CRF patients and the dialyzed patients. Plasma selenium concentrations were within the normal range in these patient groups. These results indicate that the plasma GPx activity largely depends on renal function.

Aged↗

PubMed1996

Biological behavior of human dental pulp cells in response to carious stimuli analyzed by PCNA immunostaining and AgNOR staining.

The change in proliferative and metabolic activities of human dental pulp cells responding to carious stimuli was studied by means of immunohistochemical staining for proliferating cell nuclear antigen (PCNA) and silver-binding nucleolar organizer region (AgNOR) staining. We classified the pulp tissues into five groups according to the progression of dental caries, ranging from grade 0 (the pulp of noncarious teeth) to grade 4 (the pulp of perforated carious teeth). PCNA-positive pulp cells were detected only in advanced dental caries (grades 3 and 4), and the difference in immuno-positive rate was significant between the two grades (p <0.001). However, the mean number of AgNORs per nucleus increased even in the early phase of dental caries, significant differences being detected between grades 1 and 2 (p<0.005), 2 and 3 (p<0.005), and 3 and 4 (p<0.001). Our data suggested that the metabolic activity of dental pulp cells was enhanced in the early phase of dental caries. However, proliferation of pulp cells occurred later in small degrees during fully developed caries such as grades 3 and 4. The slow and weak response in cellular proliferation might contribute to the usual fragility of the pulp to various assaults including caries or pulpitis.

Adult↗

PubMed1996

Mitosis-specific phosphorylation of smooth muscle regulatory light chain of myosin II at Ser-1 and/or -2 and Thr-9 in sea urchin egg extract.

We analyzed the kinase activities capable of phosphorylating the regulatory light chain of myosin-II (MRLC) from chicken gizzard in unfertilized and fertilized sea urchin egg extracts. Total kinase activity phosphorylating MRLC in vitro did not fluctuate throughout the first cell cycle. Phosphopeptide mapping analysis showed that MRLC was phosphorylated at two different sites corresponding to myosin light chain purified from chicken gizzard (MLCK) and protein kinase C (PKC) phosphorylation sites, namely MLCK and PKC sites, respectively. The activity of the kinase(s) responsible for phosphorylation of MRLC at PKC sites showed a significant increase at metaphase. Phosphoamino acid analysis revealed that this increase in MRLC phosphorylation was due to phosphorylation at serine residue (Ser-1 and/or Ser-2) and a threonine residue (Thr-9). This increase in phosphorylation at PKC sites is occurred concomitantly with an increase in histone H1 kinase activity. In contrast, MRLC phosphorylation at MLCK sites showed no significant changes during the first cell cycle. Butyrolactone I, a selective inhibitor of p34cdc2 kinase, inhibited the activity of the kinase(s) responsible for phosphorylation of MRLC at PKC sites at metaphase. These results suggest that the increase in MRLC phosphorylation at PKC sites (Ser-1 and/or -2, and Thr-9) at metaphase may be induced by p34cdc2 kinase. Thus, p34cdc2 kinase may be involved in the regulation of MRLC phosphorylation during cell division.

4-Butyrolactone↗

PubMed1996

Assessment of pulmonary venous and transmitral flow in closed-chest dogs under various loading conditions by transesophageal Doppler echocardiography.

Pulmonary venous flow velocity (PVFVe), pulmonary venous dimension (PVD) and transmitral flow (TMF) velocity were examined under various loading conditions in 15 anesthetized closed-chest dogs by transesophageal Doppler echocardiography (TEE). We also compared PVFVe with pulmonary venous flow volume (PVFVo) simultaneously in open-chest dogs using an ultrasonic flow probe. PVFVo decreased by more than 50% and PVD also decreased significantly during preload reduction, while there was no change in PVFVe. This discrepancy between PVFVo and PVFVe was apparently due to the collapse of pulmonary veins. TMF consisted of both rapid-filling flow velocity and atrial flow velocity components (R and A), while PVF consisted of systolic and diastolic forward flow velocity components (S and D). The peak values of R,A,S and D and the time-velocity integrals of each wave (RI, AI, SI and DI, respectively) were measured. There was a significant correlation between the changes in RI and SI/DI during preload reduction (r = 0.82, p < 0.001) and during after-load increase (r = -0.59, p < 0.05). These results suggest that changes in RI with different loading conditions might be attributable to changes in atrial reservoir volume and conduit volume.

Animals↗

PubMed1996

Preparation and some properties of type I collagen from fish scales.

Soluble collagen from fish (sardine) scales was yielded at about 5% with 0.5 M acetic acid after demineralization with EDTA, while a great portion of the collagen remained insoluble. The solubility of this insoluble collagen was about 20% at 45 degrees C (denaturation temperature of soluble collagen) for 24 h. The remaining 80% of the insoluble collagen was denatured in the form of insoluble gelatin, and that may be an interesting food material.

Amino Acids↗