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Biomedical subjects

N Yoshimura

Publications and source records attributed to N Yoshimura.

At least 361 records · Page 20Linked to original sources
PubMed1994

Insulin-like growth factor-related genes, receptors, and binding proteins in cultured human retinal pigment epithelial cells.

PURPOSE: It was determined in cultured human retinal pigment epithelial (HRPE) cells whether there is gene expression for insulin, insulin-like growth factors (IGFs), insulin and IGF receptors, and IGF-binding proteins (IGFBPs); if these peptides are secreted by the HRPE cells, and whether they have mitogenic effects on these cells; and if IGF-related peptides bind to HRPE cells. METHODS: Reverse transcriptase-polymerase chain reaction (RT-PCR), nucleotide sequencing, and Southern blot analyses were done to identify gene expression. The presence of IGFs in the tissue culture medium was detected by radioimmunoassay. For determination of mitogenic effects and receptor binding characterization, [3H]-thymidine incorporation and radioreceptor binding measurements were performed. RESULTS: The genes for IGF-I and IGF-II, IGFBP-2, insulin receptor, and type I and II IGF receptors were detected. In the tissue culture supernatant, there was immunoreactivity for IGF-I and IGF-II. Insulin, IGF-I, and IGF-II stimulated DNA synthesis with EC50s of 3, 10, and 30 to 100 nM, respectively. Scatchard analyses of [125I]-IGF-I binding and [125I]-insulin binding to the cells showed that the cells have relatively abundant insulin and IGF-I binding sites. CONCLUSIONS: HRPE cells express genes for IGF-I and IGF-II, and conditioned medium from these cells is immunoreactive to their protein products. The cells express genes for insulin receptor, type I and II IGF receptors, and IGFBP-2. IGF-I, IGF-II, and insulin are all mitogenic, possibly as a result of their interactions with either the insulin or type I IGF receptor. The cells bind insulin and IGF-I with high affinity. These results suggest that IGF-I and IGF-II production by HRPE cells may be essential for autocrine/paracrine-mediated regulation of proliferation. The presence of insulin receptor suggests that insulin has a role in the regulation of HRPE function.

Base Sequence↗
PubMed1994

The role of nitric oxide synthase in endotoxin-induced uveitis: effects of NG-nitro L-arginine.

PURPOSE: To evaluate the role of nitric oxide synthase (NOS) in endotoxin-induced uveitis (EIU). METHODS: EIU was caused in Lewis rats by injecting lipopolysaccharide (LPS) into the foot pad, and the effects of an NOS inhibitor, NG-nitro L-arginine (NA), was comparatively studied by the simultaneous administration of NA and LPS. Total NOS and inducible NOS (iNOS) activities were differentially assayed in the anterior segment of the eye in EIU with and without NA treatment. The effects of NA on EIU were also evaluated by clinical manifestation, histology, and protein concentration in the aqueous humor. RESULTS: In untreated rats, there was no significant iNOS activity. With the EIU model, iNOS activity showed a marked increase in the anterior segment of the eye, reaching a maximum 9 hours after LPS injection (10,850 +/- 1,650 cpm/mg protein, mean +/- SEM). NA reduced the iNOS activity 9 hours after injection to 2,400 +/- 90 cpm/mg protein (P < 0.001). Aqueous humor protein concentration in the EIU model was 10.6 +/- 0.75 mg/ml, and the cell number was 216 +/- 12 cells/microliters. NA significantly reduced these factors to 4.25 +/- 0.48 mg/microliters for the protein concentration (P < 0.0005) and 25 +/- 6 cells/ml for the cell number (P < 0.0005). Histologic studies showed less prominent infiltration of polymorphonuclear cells in the anterior uvea than for conventional EIU. CONCLUSIONS: Induction of iNOS may play a key role in the pathogenesis of EIU. Because inhibition of iNOS activity reduced the inflammatory response, suppression of NO formation may inhibit the development of EIU.

Amino Acid Oxidoreductases↗
PubMed1994

[Effect of nasal CPAP on human diaphragm position and lung volume].

The cephalic margin of the zone of apposition (ZOA) was observed with ultrasonography at ambient pressure and during nasal continuous positive airway pressure (nasal CPAP) in nine awake healthy males in a supine position. In a relaxed state at ambient pressure, there was a significant (p < 0.001) linear relationship between lung volume and the movement of the cephalic margin of the ZOA over the range from maximum expiratory position (MEP) to maximum inspiratory position (MIP). With nasal CPAP, functional residual capacity increased significantly (p < 0.01) in proportion to the increase in CPAP. At 20 cmH2O CPAP, the mean increase in volume at end expiration was 36% of the vital capacity measured at ambient pressure. The cephalic margin of the ZOA moved significantly (p < 0.01) in a caudal direction as CPAP was increased. At 20 cmH2O CPAP, the cephalic margin of the ZOA at end expiratory position (EEP) had moved 55% of the difference from MIP to MEP measured at ambient pressure. The end expiratory diaphragm position during nasal CPAP was lower than the diaphragm position at ambient pressure when lung volumes were equal. These results suggest that during nasal CPAP the chest wall is distorted from its relaxed configuration, with a decrease in rib cage expansion and an increase in outward displacement of the abdominal wall.

Diaphragm↗
PubMed1994

[Management of voiding dysfunction in elderly patients: effectiveness of rehabilitation and familial care].

We examined whether the improvement of impaired mobility correlates with the success rate in achievement of catheter-free or diaper-free status of 260 hospitalized elderly patients whose activities in daily life (ADL) were impaired and urinary tract dysfunctions including urinary incontinence were managed by indwelling catheters or diapers. The contribution of physical rehabilitation and/or care given by family to the improvement of impaired mobility was also investigated. All 154 patients whose ADL improved during the course of the treatment acquired the catheter-free or diaper-free status. Of 106 patients whose ADL did not improve, 85 patients became free of catheters or diapers. All of the remaining 19 patients who continued to be dependent upon catheter or diapers had been bed-ridden during the course of the treatment. Among 201 patients who were bed-ridden before the treatment, the success rate in the improvement of impaired ADL in 84 patients who underwent physical rehabilitation and received care given by family, was 83%. The ADL improved in 71% of the 70 who received rehabilitation and 53% of 17 bed-ridden patients who received familial care. By contrast, only 2 out of 30 patients who received neither of them were free from the bed-ridden condition. The remaining 28 patients continued to be bed-ridden, and the 19 cases who were not free of indwelling catheters or diapers were a part of this population of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1994

[Management of voiding dysfunction in elderly patients: prognosis 1 year after discharge from hospital].

We investigated how 293 elderly patients who had been successfully treated to be free of catheters or diapers managed to urinate one year after their discharge from our hospital. Of 192 patients who returned to their own home 154 (80%) had good activities in daily life (ADL), and of 101 who moved to a nursing home or other hospital only 7 (7%) had good ADL. Among the 192 in their own home, 151 (79%) remained free of catheters or diapers thanks to the home care services provided by trained nurses belonging to our hospital. However, among the 101 at other facilities 21 (21%) could avoid these appliances. Furthermore, those who stayed in their own home with poor ADL had a significantly higher rate of being independent of catheters or diapers (34%) compared to those who lived in facilities other than their home with poor ADL (13%). These findings indicate that the elderly patients who reside in their own home or have good ADL possess a better chance of avoiding catheters or diapers compared to those who live in other than their residence or have poor ADL, and that continued urological care coupled with the home-visiting services is effective and important in attaining these aims.

Activities of Daily Living↗
PubMed1994

[Severe ascending aortic stenosis after one-stage repair of aortopulmonary window and interrupted aortic arch].

A 33-day-old girl was transferred to our hospital because of severe cyanosis and tachypnea. The diagnosis of aortopulmonary window and interrupted aortic arch was established by echocardiogram and cineangiocardiogram. Reconstruction of aortic arch by extended direct anastomosis and simple patch closure of aortopulmonary window were performed by means of profound hypothermia and circulatory arrest on 36 days of age. Her postoperative clinical course was uneventful, but at 2 months after operation, stenosis of the ascending aorta was noticed by echocardiographic examination. As her physical growth had been satisfactory, she was managed under close observation at outpatient clinic. At seven months after operations, she fell into progressive left heart failure, and emergency operation was carried out for the relief of stenosis of the ascending aorta, but she could not come off bypass. A stenosis of the ascending aorta is a fatal complication that may occur after one-stage repair of interrupted aortic arch with aortopulmonary window consisting of extended direct anastomosis and simple patch closure. We now consider that division of ascending aorta and pulmonary artery and repair of both of the defect is indispensable for the correction of aortopulmonary window, especially in neonate and small infant with this lesion associated with interrupted aortic arch.

Aorta↗
PubMed1994

[Redo valve replacement for primary tissue failure of bioprosthetic heart valve].

We evaluated long-term results of valve replacement with bioprosthesis in 59 patients. Freedom from primary tissue failure and reoperation declined more than seven years after valve replacement. Seven patients underwent repeat operations because of primary tissue failure in our hospital. Their ages ranged from 32 to 54 years, two cases were male and five were female. At repeat operation, mechanical valve prosthesis were implanted to mitral position in all seven patients, tricuspid annuloplasty was added in five patients, and aortic valve replacement was added in one patients. The New York Heart Association (NYHA) functional classifications were grade II for 1 patient, III for 1, and IV for 5 preoperatively. Five patients had severe pulmonary hypertension preoperatively, and three of them were died after operation. The removed bioprostheses showed tears, perforations or calcifications of cusps and commissural detachments.

Adolescent↗
PubMed1994

Increased production of transforming growth factor-beta 2 from cultured human retinal pigment epithelial cells by photocoagulation.

PURPOSE: To examine whether laser photocoagulation increased production of growth factors and cytokines, especially transforming growth factor-beta 2 (TGF-beta 2), by cultured human retinal pigment epithelial (RPE) cells. METHODS: Dot blot analysis was performed to identify the changes using the conditioned medium of cultured human RPE cells with or without laser photocoagulation. The following growth factors and cytokines were examined: TGF-beta 1, TGF-beta 2, platelet-derived growth factor-BB, epidermal growth factor, interleukin-1 beta, tumor necrosis factor-alpha, and basic fibroblast growth factor. Immunostaining of the photocoagulated RPE cells was also performed by using the antibodies. Growth inhibition assay using mink lung epithelial cells (CCL-64) was employed both to quantitate active and latent forms of TGF-beta 2 secreted in the conditioned media and to determine the type of TGF-beta by using a neutralizing antibody. RESULTS: In dot blot analysis, among the growth factors and cytokines examined, production of TGF-beta 2 was changed most markedly by laser photocoagulation. This result agreed with the immunocytochemical staining pattern. Photocoagulated RPE-conditioned medium inhibited [3H]-thymidine incorporation of CCL-64. The inhibitory activity was blocked by a neutralizing antibody to TGF-beta 2. Production of active TGF-beta 2 was increased from 1.0 pg/cm2 +/- 0.6 pg/cm2 per 24 hours to 11.0 pg/cm2 +/- 1.0 pg/cm2 per 24 hours by laser photocoagulation, and that of total TGF-beta 2 was increased from 11 pg/cm2 +/- 1.0 pg/cm2 per 24 hours to 100 pg/cm2 +/- 20.1 pg/cm2 per 24 hours. CONCLUSIONS: Laser photocoagulation of cultured RPE cells increases their production of TGF-beta 2. It thus seems possible that the TGF-beta 2 produced by the RPE cells plays an important role in the processes that occur after laser photocoagulation.

Biological Assay↗
PubMed1994

[Prognosis of patient with intractable diseases in Wakayama Prefecture--a follow-up study based on medical care certificates].

To clarify the prognosis of patients with intractable diseases, a baseline survey of patients who received financial aid for intractable disease treatment between April 1984 and March 1985 was performed in Wakayama Prefecture, followed by a follow-up survey over a period of 8 years. Based on public welfare-subsidized system in Wakayama Prefecture, all patients with intractable diseases were checked up annually their certificates of financial aid for treatment. The results obtained were as follows: Parkinson's disease had the highest rate of discontinuation of medical care at 65%, followed by idiopathic thrombocytopenic purpura (ITP) at 64%, aplastic anemia at 55%, ulcerative colitis (UC) at 54%, and Behcet's disease at 50%. Systemic lupus erythematosus (SLE) had the lowest rate of discontinuation of medical care at 32%. Discontinuation was due to death in approximately 50% of the patients with SLE, scleroderma, dermatomyositis and polymyositis, and aplastic anemia. Of these, the causes of death in more than 50% were directly related to the primary diseases. However, in patients with SLE and aplastic anemia, 25% discontinued care because of cure or alleviation. Some patients remained in remission even though the prognosis for these diseases is not generally considered to be favorable. Transfer of jurisdiction to the Disabled Persons Welfare Act was seen in 28% of patients with Parkinson's disease, 24% with Behcet's disease, and 23% with ossification of posterior longitudinal ligament, diseases which are believed to cause restriction in daily activities of patients in some cases. On the other hand, cure or alleviation was the reason for discontinuation in 60-70% of patients with Buerger's disease, UC and ITP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Clinical study of optimal bypass flow for temporary bypass with centrifugal pump in surgical treatment of aneurysm of the descending thoracic aorta].

Since 1987, 33 patients were operated on for aneurysm of the descending thoracic aorta using temporary bypass with a heparin-coated centrifugal pump and heparin-coated tubes at Kobe University Hospital. Sixteen patients had true aneurysms of the descending thoracic aorta, 7 had thoraco-abdominal aneurysms and 10 had aortic dissection (DeBakey's type III). Heat exchanger and oxygenator were not included in the bypass circuit in all cases. Perfusion time was from 42 to 205 minutes (average 90 minutes). Left heart bypass was established with 1 mg/kg of systemic heparinization in 5, 0.5 mg/kg in 5, and 0 mg/kg in 23 cases. There were no complications such as perioperative embolism, acidosis, or hypothermia. During aortic cross-clamping, the arterial pressure of the lower extremity was maintained over 70 mmHg, but there was no relationship between the distal perfusion pressure and bypass flow. The urine output during temporary bypass was significantly related to the distal perfusion flow by centrifugal pump (r = 0.455, p < 0.01). Seven out of 23 patients who were bypassed under 40 ml/kg/min of distal perfusion flow showed transient renal dysfunction postoperatively, and two developed postoperative renal failure, while the other patients bypassed over 40 ml/kg/min of pump flow stayed in the normal range of the renal function, where there were statistically differences (p < 0.05). Postoperative paresis occurred in 2 patients who were also perfused under 40 ml/kg/min of bypass flow. Therefore, it is concluded that temporary bypass with centrifugal pump is a safe and well acceptable circulatory support in the surgical treatment of aneurysm of the descending aorta.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Effect of nasal-CPAP and hypercapnia on human abdominal muscles].

The effect of nasal continuous positive airway pressure (nasal-CPAP) and hypercapnia on abdominal muscles was investigated in 10 healthy volunteers in the supine position. Pairs of fine wire electrodes were inserted into the rectus abdominis, external oblique, internal oblique and transversus abdominis under direct vision provided by high resolution ultrasound echography. Ultrasound provided clear visualization of the individual muscle layers and the guide needle for electrode insertion. Monitoring end tidal CO2 (ETCO2), 1) nasal-CPAP of 15 cmH2O was applied, 2) CO2 was then added to the inspiratory limb of the nasal-CPAP system, and 3) CO2 rebreathing was also performed without nasal-CPAP. Electromyograms (EMG) were sampled and integrated. Peak values of integrated EMG were measured under the following three conditions, normocapnia, 7% ETCO2, and 9% ETCO2, with and without nasal-CPAP. In each abdominal muscle, the percentage of patients with expiratory EMG activity increased with increasing ETCO2, regardless of nasal-CPAP. Among the four muscles, the transversus abdominis was recruited most frequently, the rectus abdominis least frequently. The EMG from each muscle was activated by nasal-CPAP of 15 cmH2O under each of the three conditions. We conclude that in humans 1) nasal-CPAP and hypercapnia synergistically activate abdominal muscles, 2) the transversus abdominis is the primary expiratory muscle, and 3) the rectus abdominis is an accessory expiratory muscle.

Abdominal Muscles↗