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Biomedical subjects

Y Fujii

Publications and source records attributed to Y Fujii.

At least 541 records · Page 30Linked to original sources
PubMed1996

Quantification of glomerular TGF-beta 1 mRNA in patients with diabetes mellitus.

Transforming growth factor-beta 1 (TGF-beta 1) is a primary determinant of the mesangial expansion observed in diabetic nephropathy. In this study, we quantitated the levels of intraglomerular TGF-beta 1 mRNA in patients with diabetes mellitus using a competitive polymerase chain reaction (PCR) method. Renal biopsy specimens were obtained from 29 patients with non-insulin-dependent diabetes mellitus. Total RNA was extracted from the glomeruli and reverse transcribed into cDNA with reverse transcriptase. To prepare samples containing identical amounts of beta-actin cDNA (8 pg), we performed competitive PCR by co-amplifying mutant templates of beta-actin with a unique EcoRI site. We also used this competitive PCR method to measure TGF-beta 1 cDNA by co-amplifying mutant templates of TGF-beta 1. We observed higher expression of TGF-beta 1 mRNA in glomeruli of patients with diabetic nephropathy as compared with normal glomeruli. Intraglomerular TGF-beta 1 mRNA was elevated, even in the early stage of diabetic nephropathy. Moreover, levels of intraglomerular TGF-beta 1 mRNA correlated with values of HbA1c. These data suggest that hyperglycemia induces intraglomerular TGF-beta 1 mRNA expression in vivo, and that TGF-beta 1 overproduction may be associated with the progression of diabetic nephropathy.

Aged↗
PubMed1996

In vitro cytocidal effects of human immunodeficiency virus type 1 Nef on unprimed human CD4+ T cells without MHC restriction.

We have previously shown that the C-terminal region of human immunodeficiency virus type 1 (HIV-1) Nef antigen present on the outer surface of virus-infected cells has an affinity for uninfected T cells and that the Nef protein is responsible for T cell death. To exclude completely the possibility of MHC restriction of this cytotoxic activity, the in vitro cytotoxic potential of HIV-1 Nef against various CD4+ T cell lines as well as naive T lymphocytes was investigated using a baculovirus expression system. Insect cells expressing myristoylated Nef on their cell surface were shown to kill a proportion of CD4+ T cells within 8 h. However, N-terminal truncated and unmyristoylated Nef proteins were not present on the outer surface of insect cell membranes and failed to show any killing activity. Monoclonal antibodies against the C-terminal region of Nef inhibited cytolysis. Thus, we conclude that specific Nef-mediated cytolysis is induced by contact with unprimed CD4+ T lymphocytes without MHC restriction.

Animals↗
PubMed1996

Proteoglycans in articular cartilage revealed with a quick freezing and deep etching method.

OBJECTIVES: To clarify the three dimensional ultrastructure of proteoglycans, and their relationship with other matrix components in articular cartilage. METHODS: Specimens from rat femoral heads were examined using three techniques: (1) Histochemical staining with cationic polyethyleneimine (PEI), using a pre-embedding or a postembedding method. Some tissues were pretreated with chondroitinase ABC or hyaluronidase. (2) Quick freezing and deep etching (QF-DE). Some specimens were fixed with paraformaldehyde and washed in buffer solution before quick freezing; others were frozen directly. (3) Ultrathin sections were studied after conventional preparation. RESULTS: Proteoglycans were observed as aggregated clumps with PEI staining by the pre-embedding method, but as fine filaments by the postembedding method. They were lost with enzyme digestion; this was also demonstrated by the QF-DE method. The ultrastructure was well preserved by the QF-DE method when fixation and washing procedures were included, but not without these procedures. A fine mesh-like structure was connected to the cell membrane in the pericellular matrix. Filamentous structures suggestive of aggrecans were observed among collagen fibrils. They had side chains, approximately 50 nm in length, which branched from the central filaments at intervals of 10-20 nm, and were occasionally linked to other structures. Many thin filaments were also attached to the collagen fibrils. CONCLUSIONS: The QF-DE method incorporating paraformaldehyde fixation and buffer washing procedures revealed three dimensional, extended structures suggestive of proteoglycans.

Animals↗
PubMed1996

Ultrastructural study of the cytoskeleton of optic nerve axons in guinea pigs as revealed by a quick-freezing, deep-etching method.

The ultrastructure of the cytoskeleton of optic nerve axons in guinea pigs was examined by the quick-freezing and deep-etching (QF-DE) method. The optic nerve tissues were treated with 0.5% saponin before QF. In the replicas, the axoplasm, as observed with conventional ultrathin sections, was seen to be composed of longitudinally oriented microtubules (MT) and neurofilaments (NF). Thin and elaborate cross-linking structures were observed in the interstices between MTs, NFs, and membranous organelles. They consisted of two different types: NF-associated cross-linking structures (about 20-50 nm in length) and MT-associated structures (about 10-20 nm in length), and may play a role in the slow transport of NF and MT and fast transport of organelles, respectively.

Animals↗
PubMed1996

Buerger's disease in a middle-aged woman with diabetes mellitus. A case report.

Buerger's disease or thromboangiitis obliterans with involvement of small arteries of the upper and lower extremities usually afflicts young male smokers, but this report presents a middle-age female nonsmoker with diabetes mellitus who satisfied clinical, angiographic and histologic criteria for the diagnosis of Buerger's disease.

Adult↗
PubMed1996

Intraoperative ventilation with air and oxygen during laparoscopic cholecystectomy decreases the degree of postoperative hypoxaemia.

We studied the effects of intraoperative use of air in oxygen (O2) (FiO2 = 0.33) versus nitrous oxide (N2O) in O2 (FiO2 = 0.33) on the degree of postoperative hypoxaemia in 30 patients undergoing laparoscopic cholecystectomy. Patients were randomly allocated to receive either general anaesthesia with air (Group A, n = 15) or with N2O (Group N, n = 15). Arterial gas tensions were measured before, 24 h and 48 h after surgery while breathing room air. The mean PaO2 24 h and 48 h postoperatively decreased significantly in both groups compared with the preoperative values. The mean PaO2 24 h postoperatively in Group N (74.6 +/- 6.4 mmHg) tended to be lower than that in Group A (78.1 +/- 8.3 mmHg). The mean PaO2 48 h postoperatively in Group N (75.0 +/- 7.8 mmHg) was significantly lower than that in Group A (83.5 +/- 7.9 mmHg) (P < 0.05). On the contrary, the mean PaCO2 did not show any significant change during 48 h postoperatively in either group. Our results suggest that ventilation with N2O and O2 during laparoscopic cholecystectomy is associated with a lower degree of postoperative hypoxaemia.

Adult↗
PubMed1996

Novel ipriflavone receptors coupled to calcium influx regulate osteoclast differentiation and function.

Ipriflavone (7-isopropoxyisoflavone) is an effective antiresorptive agent used to treat osteoporosis. However, the mechanism of its action on osteoclasts and their precursor cells is not well understood. To determine whether the mechanism involves direct effects on osteoclasts or their precursors, we examined the effects of ipriflavone on cytosolic free calcium ([Ca2+]i) in osteoclasts and their precursors and measured specific binding of 3H-labeled ipriflavone. Highly purified chicken osteoclast precursors, which spontaneously differentiate into multinucleated osteoclasts in 3-6 days, were loaded with fura-2, and the subcellular [Ca2+]i distribution was monitored by videoimaging. Ipriflavone induced a rapid increase in [Ca2+]i followed by a sustained elevation [EC50 = 5 x 10(-7) M, 263 +/- 74 nM (SE) (n = 8) above basal levels, by 10(-6) M ipriflavone, sustained phase]. The responses were the same in differentiated chicken osteoclasts and isolated rabbit osteoclasts. An influx of extracellular Ca2+ is likely to be responsible for the ipriflavone-induced change in [Ca2+]i because the response was abolished by 0.5 mM LaCl3, or by Ca-free medium containing EGTA. Moreover, high [Ca2+]i levels were detected adjacent to the cell membrane after ipriflavone addition. Ipriflavone induced Ca influx mainly through dihydropyridine-insensitive Ca2+ channels, because nicardipine (10(-7)M) and verapamil (10(-7)M) had no effects on ipriflavone-induced [Ca2+]i responses. [3H]Ipriflavone binding studies indicated the presence of specific ipriflavone binding sites (two classes), both in precursor cells [dissociation constant (Kd), 7.60 x 10(-8)M, 2.67 x 10(-6)M] and in mature osteoclasts (Kd, 4.98 x 10(-8)M, 3.70 x 10(-6)M). Specific ipriflavone binding was not displaced by various modulators of avian osteoclast function, such as estradiol (10(-8)M) or retinoic acid (10(-6)M), indicating that ipriflavone receptors differ from the receptors for these Ca-regulating hormones. The fusion of osteoclast precursor cells was significantly inhibited by ipriflavone, which led to dose-dependent inhibition of bone resorption and tartrate-resistant acid phosphatase activity. Novel specific ipriflavone receptors that are coupled to Ca2+ influx were demonstrated in osteoclasts and their precursor cells. These ipriflavone receptors may provide a mechanism to regulate osteoclast differentiation and function.

Acid Phosphatase↗
PubMed1996

Central alveolar hypoventilation syndrome (Ondine's curse) with gastroesophageal reflux.

Congenital central hypoventilation syndrome (Ondine's curse) is a rare disorder with lack of automatic control of ventilation during sleep. We have reported a case of Ondine's curse in a patient who underwent Nissen's fundoplication for gastroesophageal reflux (GER) at age 5 months. Ventilatory challenge test during sleep was done to confirm central alveolar hypoventilation. This female patient, without cor pulmonale, was a good candidate for diaphragm pacing. Thus, the patient underwent implantation of a diaphragm pacer at age 3 years; she had required mechanical ventilation since birth. Diagnosis, pathogenesis, and problems in the setting of diaphragm pacing for an infant are discussed.

Child, Preschool↗
PubMed1996

[Clinicopathological study of diabetic nephropathy in the elderly].

We studied the relationship between clinical characteristics and renal structural changes in 29 elderly patients in whom non-insulin-dependent diabetes mellitus was diagnosed when they were 60 years of age or older. The clinical stage of nephropathy was graded according to the criteria of the Ministry of Health and Welfare of Japan: stage 1 (12 patients), normoalbuminuria; stage 2 (11 patients), microalbuminuria; stage 3 (1 patient), persistent proteinuria; stage 4 (5 patients), chronic renal failure. Renal biopsy specimens were semiquantitatively evaluated with regard to diffuse glomerular lesions, nodular lesions, and vascular lesions. In patients at stage 1, minimal-to-moderate diffuse lesions were observed, and vascular lesions were already present. In patients at stage 2, various alterations in diffuse lesions were observed and were associated with prominent changes in the vascular lesions. More advanced changes in the diffuse and vascular lesions were noted in patients at stages 3 and 4, but nodular lesions were found in only one patient. These patients had a high incidence of hypertension and ischemic heart disease. We conclude that elderly diabetic patients with nephropathy of different clinical stages have different underlying diabetic renal lesions.

Aged↗
PubMed1996

Ultra-early rebleeding in spontaneous subarachnoid hemorrhage.

To determine the incidence of, and risk factors for, the occurrence of rebleeding between admission and early operation (ultra-early rebleeding) in patients with spontaneous subarachnoid hemorrhage (SAH), the authors reviewed the cases of 179 patients admitted within 24 hours after their last attack of SAH. Thirty-one (17.3%) of these patients had ultra-early rebleeding despite scheduling of early operation (within 24 hours after admission). The incidence of rebleeding significantly decreased as the time interval between the last attack and admission increased. Patients with rebleeding before admission, high systolic blood pressure, intracerebral or intraventricular hematoma, those in poor neurological condition on admission, and those who underwent angiography within 6 hours of the last SAH were significantly more likely to have ultra-early rebleeding than those without these factors. The incidence of rebleeding also significantly increased as levels of enhancement of platelet sensitivity and thrombin-antithrombin complex increased. Multivariate analysis revealed that the following three factors were independently associated with ultra-early rebleeding: the level of enhancement of platelet sensitivity; the time interval between the last attack and admission; and the level of thrombin-antithrombin complex. On the basis of these findings, the authors suggest that many of the risk factors for ultra-early rebleeding are interrelated. A particularly high risk of ultra-early rebleeding was observed in those patients 1) who had platelet hypoaggregability; 2) who were admitted shortly after their last SAH; and 3) whose thrombin-antithrombin complex levels were extremely high and were thus in severe clinical condition.

Cerebral Angiography↗
PubMed1996

[Prognostic factors of renal cell carcinoma: a multivariate analysis].

In a series of 104 patients with renal cell carcinoma, a variety of clinical and histological factors were analyzed to establish their value as prognostic factors. In a univariate analysis (log-rank test), the presence or absence of symptoms, tumor size, pT, N, M, pV categories, TNM stage, Robson stage, nuclear grade and cell type were significantly associated with cause-specific survival, while age, sex and tumor side were not. In a multivariate analysis using Cox's proportional hazard model of 73 informative cases, only N (0 vs. 1-3) and M (0 vs. 1) categories of stage and nuclear grade (1-2 vs. 3) proved to be independent prognostic markers.

Aged↗
PubMed1996

[Serum and urinary pyridinium cross-links in patients with predialysis chronic renal failure].

The concentrations of pyridinoline (Pyr), a novel marker of bone resorption, were simultaneously measured in both serum and urine samples by ion-paired high-performance liquid chromatography in 27 patients with predialysis chronic renal failure. The patients consisted of 19 males and 8 females, whose creatinine clearance (Ccr) ranged from 2.5 to 47.6 ml/min. The influence of residual renal function on serum Pyr and the clinical significance of serum and urinary Pyr were analyzed in patients with predialysis chronic renal failure. There were significant correlations between serum Pyr and serum Cr (r = 0.76) and between Pyr clearance and Ccr (r = 0.70). In addition, significant correlations were observed serum and urinary Pyr (r = 0.64) and between both serum and urinary Pyr and HS-PTH (r = 0.96 and r = 0.61, respectively) and osteocalcin (r = 0.80 and r = 0.73, respectively). However, serum bone alkaline phosphatase isoenzyme (ALP3) was correlated with neither serum nor urinary Pyr. There was no correlation between the ratio of serum Pyr/serum Cr and the metabolic bone markers (HS-PTH, osteocalcin and ALP3). There was a correlation between Ccr and urinary Pyr, although it was statistically significant (p < 0.1). These date led to the following conclusions: (1) serum Pyr in patients with oredialysis chronic renal failure is influenced by reduced renal function and (2) urinary pyr shows a state of bone resorption when an adegvafe level of renal function is maintained. This suggests that patients with an advanced stage of renal osteodystrophy are included among cases of predialysis chronic renal failure.

Adult↗
PubMed1996

An ultrastructural study of goblet cells in rat nasal mucosa as revealed by the quick-freezing method.

In order to clarify the natural ultrastructure of goblet cells in the rat nasal mucosa, they were examined by the quick-freezing and freeze-substitution (QF-FS) or deep-etching (QF-DE) methods for comparison with conventional fixation methods. Some nasal mucosal tissues were unstimulated; others were stimulated with acetylcholine or substance P. The QF-FS method yielded fewer artefacts on transmission electron microscopy than conventional fixation methods. In the stimulated goblet cells, most of the secretory granules appeared to be loose in the matrix and more distorted in shape. By the QF-DE method, they were observed 3-dimensionally to be larger in size and aggregated together. In contrast, the secretory granules in the unstimulated goblet cells were mostly round and small, and separate from each other. It is concluded that the ultrastructure of secretory granules is artefactually modified by conventional fixation methods and that granule structure in goblet cells alters during the secretory process.

Acetylcholine↗
PubMed1996

Exercise performance of rats after isogenic left or right lung transplantation followed by contralateral pulmonary artery ligation.

BACKGROUND: After single lung transplantation for pulmonary hypertension, large mismatches in ventilation/perfusion distribution persist late after transplantation. The larger graft volume of the transplanted lung after transplantation, the better the exercise performance. Because the right lung is larger in volume than the left, we compared the left single lung transplant with the right single lung transplant regarding exercise performance with an animal model. METHODS: To simulate significant ventilation/perfusion imbalance observed after single lung transplantation for pulmonary hypertension, we transplanted isogenic left or right pulmonary grafts to normal rats, and the contralateral pulmonary artery was ligated 2 weeks after transplantation. The treadmill test was performed weekly until 6 weeks after transplantation to measure maximum tolerated running speed and maximum oxygen uptake. RESULTS: Graft vital capacity of left and right pulmonary grafts were 4.5 +/- 0.43 ml (37% +/- 3.7% of recipient's predicted vital capacity) and 7.8 +/- 0.34 ml (63% +/- 2.4%), respectively (p < 0.01). Maximum tolerated speeds of left and right single lung transplants were 8 +/- 7.6 and 29 +/- 2.2 m/min, respectively, at 6 weeks after transplantation (p < 0.01). Maximal oxygen uptake values of left and right single lung transplants were 34 +/- 12.0 and 65 +/- 3.8 ml/kg/min, respectively (p < 0.01). CONCLUSIONS: Results suggest that right lung transplantation is superior to left lung transplantation for pulmonary hypertension in terms of exercise performance in this animal model.

Animals↗
PubMed1996

Three-dimensional ultrastructure of in situ membrane skeletons in human erythrocytes by quick-freezing and deep-etching method.

The erythrocyte membrane skeleton is a network of some structural proteins, principally composed of spectrin, actin and protein 4.1, which is also attached to the cytoplasmic surface of the lipid membrane. The purpose of the present review is to describe the three dimensional ultrastructure of in situ membrane skeletons in human erythrocytes. The in situ membrane skeletons are densely organized, and the spectrin itself has a property of extension or contraction with reacting the external mechanical forces. The lengths between the intersections are changed according to the mechanical strength, and also vary even in one erythrocyte. To clarify the in situ organization of membrane skeletons, the quick freezing and deep-etching method should be used for fresh unfixed erythrocytes because of their fragility during preparation steps.

Cytoskeletal Proteins↗
PubMed1996

[Thymic carcinoma effectively treated by preoperative concurrent chemo-radiotherapy].

A 59-year-old woman was admitted our hospital because of an abnormal shadow on a chest X-ray film. A chest CT scan showed a large anterior mediastinal tumor and a pericardial effusion. Percutaneous needle biopsy revealed that the tumor was an advanced thymic cancer (squamous cell carcinoma). The patient underwent 1 course of systemic chemotherapy (CDDP + VDS) with concurrent radiation therapy (24 Gy). In addition, one more course of chemotherapy (CDDP + VDS) was given. A chest CT scan done after therapy showed an approximately 75% reduction in tumor size (partial response) and disappearance of the pericardial effusion. The levels of tumor markers (SCC 8.3 ng/ml, CYFRA 21-1 183 ng/ml) also decreased to within the normal range. Finally, the thymic carcinoma and small pulmonary metastatic lesions were all resected. Examination of the resected tumor revealed extensive necrosis and only a few cancer cells. These results show that concurrent chemo-radiation therapy can be effective against inoperable squamous cell carcinoma of the thymus.

Antineoplastic Combined Chemotherapy Protocols↗