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Biomedical subjects

S Kishi

Publications and source records attributed to S Kishi.

At least 37 records · Page 2Linked to original sources
PubMed2000

Tomographic assessment of vitreous surgery for diabetic macular edema.

PURPOSE: To evaluate the retinal structure before and after vitrectomy for diabetic macular edema and to assess the correlation between thickness of neurosensory retina and best-corrected visual acuity. METHODS: Tomographic features of 13 eyes (nine patients) with diabetic macular edema were prospectively evaluated with optical coherence tomography before and after vitrectomy. The foveal thickness (the distance between the inner retinal surface and the retinal pigment epithelium) and the retinal thickness (thickness of neurosensory retina) were measured by optical coherence tomography preoperatively and postoperatively. The correlation of the best-corrected visual acuity with foveal and retinal thickness was determined. RESULTS: All 13 eyes had retinal swelling with low intraretinal reflectivity. In addition to retinal swelling, there were cystoid spaces in five (38%) of 13 eyes, a serous retinal detachment in three (23%), and both cystoid spaces and serous detachment in three (23%). Six months postoperatively, the mean foveal thickness significantly decreased from 630 +/- 170 to 350 +/- 120 microm (P <.01, paired t test) and the mean thickness of neurosensory retina decreased from 540 +/- 160 to 320 +/- 140 microm (P <.01, paired t test). A serous retinal detachment occurred transiently in 3 eyes. Compared with the preoperative level, the postoperative best-corrected visual acuity level improved by more than 2 lines in five of the 13 eyes (38%), remained the same in seven eyes (54%), and decreased in one eye (8%). The postoperative thickness of neurosensory retina at the fovea and best-corrected visual acuity level at the sixth postoperative month had a strong negative correlation (correlation coefficient, -0.76; P <.01, Spearmans rank test). CONCLUSIONS: Vitrectomy was generally effective in treatment of diabetic macular edema. Optical coherence tomography demonstrated the intraretinal changes of macular edema and the process of edema absorption. During the process of macular edema absorption, intraretinal fluid appeared to move into the subretinal space in some cases. Best-corrected visual acuity improvement was greater in eyes with less preoperative increase in thickness of neurosensory retina.

Aged↗
PubMed2000

Remodeling of choroidal venous drainage after vortex vein occlusion following scleral buckling for retinal detachment.

PURPOSE: To evaluate the choroidal drainage route after scleral buckling for retinal detachment. METHODS: We performed wide-angle indocyanine green angiography with a scanning laser ophthalmoscope in 22 eyes of 22 patients with rhegmatogenous retinal detachment that had been treated with scleral buckling and cryopexy. The 22 eyes had at least one retinal break located posterior to the equator where vortex veins were present. The period between angiography and retinal detachment surgery was less than 3 months in 10 eyes, 3 to 12 months in five eyes, and more than 1 year in seven eyes. RESULTS: At the site of the silicone exoplant and cryopexy for retinal breaks, one vortex vein was occluded in seven eyes and two in five eyes. Choroidal veins were congested in the quadrant of the occluded vortex vein in two of 12 eyes that had angiography less than 3 months after retinal detachment surgery. In 10 of 12 eyes that had angiography 3 months or more after retinal detachment surgery, new drainage routes developed that connected the sector of the occluded vortex veins to that of the intact vortex veins with venovenous anastomoses. No venous congestion was found in the areas of the occluded vortex veins in the 10 eyes. Venous collaterals formed between the superior and inferior vortex in all 10 eyes and between the temporal and nasal vortex in two eyes. CONCLUSIONS: New venous drainage routes, which were connected to the intact vortex veins, formed in eyes with occluded vortex veins resulting from scleral buckling surgery and compensated for choroidal venous congestion. The choroidal veins have a great deal of plasticity that enables remodeling of the drainage routes, depending on the pressure gradient.

Adolescent↗
PubMed2000

Effect of PSC 833 on the cytotoxicity and pharmacodynamics of mitoxantrone in multidrug-resistant K562 cells.

We examined the effect of PSC 833, a nonimmunosuppressive cyclosporin analogue, on the cytotoxicity, accumulation and retention of an anthraquinone antileukemia drug mitoxantrone (MIT). This was done in P-glycoprotein (PGP)-overexpressing multidrug-resistant K562/D1-9 cells and compared with the effect of cyclosporin A (CsA). We also compared MIT with the effect of PSC 833 on the cytotoxicity of daunorubicin (DNR) and doxorubicin (DOX). While PSC 833 and CsA had no effect on the cytotoxicity, accumulation and retention of MIT in the parent K562 cells, PSC 833 and CsA restored accumulation and retention of MIT in K562/D1-9 cells dose-dependently. Consequently, there was increased sensitivity of K562/D1-9 cells to MIT. The reversing activity of PSC 833 on the cytotoxicity of MIT was stronger than that of CsA, and was almost the same as the reversing activity of PSC 833 on the cytotoxicity of DNR and DOX. The resistance index of MIT decreased from 43.9-fold to 2.8-fold by 0.4 microM PSC 833, which is a clinically achievable plasma concentration. These results suggest that the combination of PSC 833 with MIT could be a promising treatment in reversing PGP-mediated MDR in leukemia patients.

Antineoplastic Agents↗
PubMed2000

FK506 inhibition of histamine release and cytokine production by mast cells and basophils.

Histamine release and cytokine production by mast cells and basophils are thought to be closely involved in the pathogenesis of allergic diseases. Some reports show that FK506 (tacrolimus hydrate) inhibited histamine release and cytokine production by mast cells and basophils. However, as the effects of FK506 has not been compared with those of clinically used drugs in those reports, the clinical relevancy of FK506 inhibition remained unclear. In this paper, we compared the actions of FK506 with those of steroids or disodium cromoglycate (DSCG) which has been clinically used. FK506 inhibited histamine release by Brown-Norway rat peritoneal mast cells more potently than steroids and especially DSCG. FK506 also inhibited histamine release by a mast rat basophilic leukemia (RBL)-1 cell line and human peripheral blood basophils, whereas steroids failed to inhibit histamine release by human basophils. FK506 as well as steroids inhibited TNF-alpha and IL-4 production by RBL-1 cells. FK506 was therefore more effective than steroids and DSCG in inhibiting histamine release, and it also had the ability of inhibiting cytokine production by mast cells as steroids do. We concluded that FK506 might regulate allergic diseases via these actions, judging from the viewpoint of clinical relevancy.

Animals↗
PubMed2000

Torsade de pointes associated with hypokalemia after anthracycline treatment in a patient with acute lymphocytic leukemia.

Severe dose-dependent anthracycline cardiotoxicity is reported to cause myocardial damage resulting in congestive heart failure. However, torsade de pointes, a life-threatening arrhythmia caused by chronic anthracycline cardiotoxicity, has not been reported previously. A 16-year-old girl who developed torsade de pointes after 6 months of chemotherapy for acute lymphocytic leukemia (French-American-British classification L2) is described. When the patient was readmitted to the hospital because of syncope, peripheral blood and bone marrow analysis indicated a relapse. In addition, the patient was hypokalemic. Twenty-four-hour ambulatory electrocardiographic monitoring demonstrated QT prolongation and an episode of torsade de pointes. The electrocardiographic changes and arrhythmia improved after correction of the hypokalemia. An inverse correlation between leukocyte count and hypokalemia was observed. The patient died from pulmonary hemorrhage. Autopsy examination demonstrated myocardial degeneration consistent with damage induced by antineoplastic antibiotics. The cumulative dose of anthracycline and anthraquinone was less than the conventional dose limit associated with chronic cardiotoxicity, even for children who are more sensitive to anthracyclines. Torsade de pointes can occur in the setting of chronic anthracycline cardiotoxicity. Therefore, children or young adults who are more sensitive to anthracycline need careful observation that includes electrolyte monitoring, especially for potassium.

Adolescent↗
PubMed1999

Evaluation of cell-killing effects of 1-beta-D-arabinofuranosylcytosine and daunorubicin by a new computer-controlled in vitro pharmacokinetic simulation system.

An in vitro pharmacokinetic simulation system that can simulate plasma pharmacokinetics was established to evaluate the cytotoxicity of two representative antileukemic agents, 1-beta-D-arabinofuranosylcytosine (ara-C) and daunorubicin. With this system, the survival rate of the cell line K562 treated with ara-C, relative to that of untreated control cells, was 7.1%, as determined by a clonogenic culture technique using a clinically intermediate dose of ara-C (1.0 g/m2; 2-h infusion). When the area under the serum concentration-time curve (AUC) was kept constant at infusion times of 2, 4, 8, and 16 h with a regular dose of ara-C (100-mg/m2 infusion), the relative cell survival rates were 75, 72, 34, and 14%, respectively. In contrast, with the use of a conventional culture system and a constant concentration-time product (C x T), no time-dependent inhibition effect by ara-C was observed, probably due to the ara-C inactivation in the cell-containing culture medium. For example, 93% of the ara-C in the cell-suspended medium in the conventional culture system was converted to its inactive form, 1-beta-D-arabinofuranosyluracil, within 16 h after addition of ara-C to the medium. For the simulations of the administration of 50 mg/m2 daunorubicin for 0.5-, 2-, 4-, and 8-h infusions, the relative survival rates [maximal concentrations (Cmaxs)] were 37.4% (0.24 microM), 49.7% (0.089 microM), 72.1% (0.055 microM), and 82.2% (0.032 microM), respectively. With the conventional culture system, the relative survival rates (Cmaxs) following daunorubicin treatment were 7.6% (0.48 microM), 18.6% (0.12 microM), 63.7% (0.06 microM), and 92.0% (0.03 microM) when the drug exposure times were 0.5, 2, 4, and 8 h, respectively, with a constant C x T. When the drug concentration for 90% cell killing by the conventional culture system was plotted against the exposure time on a logarithmic scale, the regression line for daunorubicin had a slope of -0.40, whereas the slope of cis-diamminedichloroplatinum (or cisplatin), a typical AUC-dependent drug, was -0.98. These results suggested that daunorubicin was Cmax dependent rather than AUC dependent. In the simulation system, this Cmax dependency was apparently reduced, probably because of the smaller difference of Cmaxs in the simulation system compared with the conventional system with the constant AUC. Thus, this simulation system can predict the effects of ara-C, daunorubicin, and other antineoplastic agents much more exactly than the conventional culture system in clinical use.

Antineoplastic Agents↗
PubMed1999

Functional neurokinin NK-1 receptor expression in rat peritoneal mast cells.

OBJECTIVE AND DESIGN: Recently, Ogawa et al. [17] reported that the peritoneal mast cells (PMCs) of rats can release histamine by substance P (SP) in a receptor-dependent manner. In the present study, we confirmed and extended their findings. MATERIAL: PMCs were isolated from six strains of rats. In some experiments, peritoneal cells in the non-MC fraction were used. METHODS: PMCs were incubated with SP, neurokinin (NK) receptor agonists or antagonists, and histamine content in the supernatant was measured. In the binding assay, PMCs were incubated with [125I]BH-SP together with SP or NK receptor antagonists. NK-1 receptor mRNA was detected using a reverse transcription-polymerase chain reaction (RT-PCR) assay. RESULTS: PMCs from Slc: Wistar and F344/NSlc were highly sensitive to SP, leading to histamine release, whereas those from Slc:SD and three other strains were not. PMCs from Slc:Wistar and F344/NSlc also released histamine in the presence of an NK-1 agonist. The histamine release induced by SP and the NK-1 agonist was inhibited by the NK-1 receptor antagonists, FK888 and CP-99,994. [125I]BH-SP binding experiments revealed that PMCs from Slc:Wistar rats possessed a single high affinity binding site for SP and that the binding was blocked by NK-1 receptor antagonists. Peritoneal cells in the non-MC fraction exhibited no appreciable binding. In the RT-PCR assay, expression of NK-1 receptor mRNA was evident in Slc:Wistar PMCs, but not in the non-MC fraction from Slc:Wistar or Slc: SD PMCs. CONCLUSION: These data demonstrate the existence of functional NK-1 receptors on freshly isolated PMCs in at least some strains of rats.

Animals↗
PubMed1999

Patterns of diabetic macular edema with optical coherence tomography.

PURPOSE: We report cross-sectional images of diabetic macular edema and correlation between tomographic features and visual acuity with best correction by means of optical coherence tomography. METHOD: In a prospective study, optical coherence tomography was performed in 59 eyes of 42 patients with diabetic macular edema and in 10 eyes of 10 normal control subjects. RESULTS: Optical coherence tomography showed three patterns of structural changes in diabetic macular edema: sponge-like retinal swelling (52 [88%] of 59 eyes), cystoid macular edema (28 [47%] of 59 eyes), and serous retinal detachment (9 [15%] of 59 eyes). Some eyes had more than one pathologic change. Retinal swelling was more pronounced in the outer rather than the inner retinal layers. Cystoid macular edema was located mainly in the outer retinal layers. In eyes with long-standing cystoid macular edema, cystoid spaces had fused, resulting in a large cystoid cavity involving almost the entire retinal layer. Hard exudates were seen as highly reflective areas located in the outer retinal layers. The retinal thickness at the central fovea and the visual acuity with best correction showed an intermediate negative correlation in eyes without cystoid macular edema (correlation coefficient: -0.61, P < .01). CONCLUSIONS: Diabetic macular edema involved three structural changes, including sponge-like retinal swelling (88%), cystoid macular edema (47%), and serous retinal detachment (15%). Visual acuity with best correction moderately correlated with retinal thickness regardless of the different tomographic features.

Adult↗
PubMed1999

Optical coherence tomography images of spontaneous macular hole closure.

PURPOSE: To investigate optical coherence tomography images of spontaneous macular hole closure. METHOD: Case report. In a 60-year-old woman with full-thickness macular hole, posterior vitreous detachment, and previous branch retinal vein occlusion, we observed the entire course of spontaneous macular hole closure by use of optical coherence tomography. RESULTS: Spontaneous macular hole closure began as the inward protrusion of the tissue around the margin of the macular hole. The protruding tissue then connected to bridge the macular hole, which mimicked a foveal retinal detachment. The bridged tissue gradually thickened, and the foveal detachment and perifoveal cysts resolved. The fovea eventually regained its normal configuration. CONCLUSIONS: The bridging of the protruding retinal tissue over the macular hole plays a key role in spontaneous macular hole closure.

Cysts↗
PubMed1999

Foveal retinoschisis and retinal detachment in severely myopic eyes with posterior staphyloma.

PURPOSE: To evaluate the tomographic features of the retina in patients with severe myopia and posterior staphyloma. METHODS: In a prospective study of 32 eyes of 19 consecutive patients with severe myopia and posterior staphyloma, we performed complete ophthalmic examinations and studied cross-sectional images of the macula with optical coherence tomography. Patients' age ranged from 41 to 83 years (average, 62.7 years). Best-corrected visual acuity ranged from 20/500 to 20/40 (average, 20/120). The study included 26 phakic and six pseudophakic eyes. The refractive errors of 26 phakic eyes ranged from -8 to -31 diopters (average, -16.7 diopters). Although refractive errors were within -8 diopters in six pseudophakic eyes, the eyes had apparent posterior staphyloma. The axial lengths measured by A-mode ultrasonography ranged from 25.7 to 32.7 mm (average, 29.2 mm). Slit-lamp examination with contact lens showed that none of the eyes had a macular hole. RESULTS: In nine eyes with shallow retinal elevation on slit-lamp examination, optical coherence tomography disclosed a foveal retinal detachment with retinoschisis in eight eyes and a foveal retinal detachment in one eye. Two of the remaining 23 eyes had retinoschisis. CONCLUSIONS: Foveal retinal detachment and retinoschisis are common features in severely myopic eyes with posterior staphyloma. Retinal detachment may precede the formation of a macular hole in severely myopic eyes.

Adult↗
PubMed1999

Peripheral blood stem cell collection and transplantation using the Haemonetics Multi Component System.

AIM: To assess clinical usefulness of an intermittent-flow blood cell separator in peripheral blood stem cell (PBSC) collection and transplantation. RESULTS: The Haemonetics Multi Component System (Multi) was used to collect PBSC (52 aphereses in 17 patients). The mean processing blood volume and the mean PBSC yield were 7407 ml and 2.16 x 10(6) CD34+ cells/kg, respectively. When CD34+ cells exceeded 0.3% of the peripheral WBC, more than 2.0 x 10(6) CD34+ cells/kg could be collected by a single apheresis. Eight patients underwent PBSC transplantation after high-dose chemotherapy. Hematopoietic recovery was achieved in a median period of 10 days. CONCLUSIONS: (1) A single-arm, light-weight machine has sufficient capability to collect PBSC. (2) The percentage of CD34+ cells in the peripheral WBC is a good predictor of the CD34+ cell yield of the collection.

Adult↗
PubMed1999

Persistent and bilateral choroidal vascular abnormalities in central serous chorioretinopathy.

BACKGROUND: To clarify the role of choroidal vascular abnormalities in central serous chorioretinopathy (CSC) in active stage, remission, and recurrence. METHODS: Indocyanine green angiography and fluorescein angiography were performed in 105 eyes (104 patients) with active CSC. Forty-six patients were followed up for 6 to 48 months (mean +/- standard deviation, 22.5 +/- 8.9 months) with repeated angiography (mean +/- standard deviation, 3.5 +/- 1.5 times). Indocyanine green angiography and fluorescein angiography also were performed during remission in all 46 eyes with CSC and during recurrent CSC in 6 eyes. Unaffected fellow eyes underwent angiographic examinations in all patients. RESULTS: In active CSC, indocyanine green angiography showed a choroidal filling delay (71%), venous dilation (61%), and focal choroidal hyperfluorescence (96%) surrounding leakage from the retinal pigment epithelium. Focal choroidal hyperfluorescence was present in unaffected areas of affected eyes (55%). The choroidal venous dilation (36%) and choroidal hyperfluorescence (62%) were noted even in unaffected fellow eyes. These choroidal abnormalities persisted during remission after leakage ceased throughout the follow-up period. In the six patients with recurrent CSC, new leakage developed in the areas of persistent choroidal hyperfluorescence. Central serous chorioretinopathy developed in the unaffected fellow eye in one of these six patients. CONCLUSION: Choroidal vascular abnormalities persist in both eyes even after leakage from the retinal pigment epithelium ceases. Central serous chorioretinopathy may recur in areas of choroidal vascular abnormalities.

Adult↗
PubMed1999

Assessment of macular function by multifocal electroretinogram before and after macular hole surgery.

AIM: To evaluate macular function before and after successful surgical closure of idiopathic macular holes using multifocal electroretinogram (ERG). METHODS: 40 patients (40 eyes) with idiopathic macular holes were examined using multifocal ERG both before and after vitreous surgery. The postoperative period was from 1 to 12 months. RESULTS: Preoperatively, the electrical retinal response densities in the foveal and the perifoveal area were apparently decreased. After a mean postoperative period of 3-6 months, the foveal and perifoveal area electrical retinal response densities improved to two to four times the preoperative level and the improvement continued to 1 year after surgery. CONCLUSION: In macular holes, the decrease in retinal electrophysiological response was not limited to the fovea but involved an area of the perifovea of 1.6 disc diameters. The electrical retinal response density of these areas gradually improved after macular hole closure.

Aged↗
PubMed1999

Characteristics of proportional analysis for soft tissue facial profile: epidemiological possibilities of measurement item reduction.

Lundström et al. proposed a proportional analysis system for the soft tissue facial profile in the natural head position. To use this method for further epidemiological investigation and to interpret the characteristics of this analysis, each measurement (index) was identified in comparison to the other indices using cluster and factor analyses. Facial profiles of 111 (mean age: 22.9 years) Japanese males were measured and 11 indices (8 horizontal, 2 vertical and 1 horizontal/vertical) were calculated. Almost all internal co-relationships between each index were statistically significant (p < 0.05, 0.01). Variable cluster analysis classified indices into four major clusters and clarified the attributes of the 11 indices. The first cluster was index No. 1, 2, 3 and 7. The second cluster was index No. 6. The 3rd cluster was index No. 4, 5, 11, 8 and 10. The 4th cluster was index No. 9. These clusters are thought as vertical facial balance, upper and lower jaw relation or horizontal/vertical balance, chin morphology, and horizontal facial balance. From factor analysis, three factor axes that explained the characteristics of 11 indices were found (accumulated contribution rate: 76.5%). The heaviest loading factor was index No. 1,2 (0.95) on axis I, 5 (0.83) on axis II and 6 (0.78) on axis III. Therefore, axis I, axis II and axis III are thought to be based on the position of the soft tissue Nasion, SLI and Pogonion, respectively. Common indices which are included in both analyses are thought to be valid as a clue to reduce the number of measurement parameters.

Adult↗
PubMed1999

[Three cases of carotid cavernous sinus fistulas where the main ocular manifestation was restricted ocular motility].

BACKGROUND: Some cases of carotid cavernous sinus fistulas (CCFs) have few ocular congestive signs and symptoms. These cases need to be accurately diagnosed as having CCFs. CASES: Three patients with CCFs without ocular congestive signs or symptoms developed unilateral abducens restriction and visited our clinic. FINDINGS: Color Doppler imaging revealed retrograde flow of the superior ophthalmic veins bilaterally in the three cases. The diagnose of CCF was confirmed by cerebral angiography. CONCLUSION: It is sometimes difficult to diagnose CCF, when a patient without ocular congestive signs or symptoms shows disturbed ocular motility as the only ocular manifestation. In such cases, color Doppler imaging may show the presence of CCF.

Aged↗
PubMed1999

Hepatic tumor rupture following effectual treatment with irinotecan in a patient with highly refractory malignant lymphoma.

We describe a patient with highly refractory malignant lymphoma who died of hepatic tumor rupture following treatment with irinotecan (CPT-11). This 60-year-old man with non-Hodgkin's lymphoma (diffuse large B-cell lymphoma) demonstrated disease recurrence in the liver and the vertebrae following high-dose chemotherapy and autologous hematopoietic stem cell transfusion. He was treated with CPT-11 at a dose of one third of the conventional dose used for non-Hodgkin's lymphoma in Japan. The tumor in the liver markedly decreased in size but then ruptured. Although pathologic hepatic tumor rupture is a rare complication in patients with malignant lymphoma of the liver, this case demonstrates that hepatic tumor rupture may occur in refractory malignant lymphomas that reveal extensive degradation by this new, effective salvage therapy.

Antineoplastic Agents, Phytogenic↗