Biomedical subjects

D M Kim

Publications and source records attributed to D M Kim.

At least 37 records · Page 2Linked to original sources

PubMed1999

Effect of diode laser trans-scleral cyclophotocoagulation in the management of glaucoma after intravitreal silicone oil injection for complicated retinal detachments.

AIMS: To evaluate the effect of trans scleral cyclophotocoagulation (TSCPC) on intraocular pressure (IOP) in the eyes retaining intravitreal silicone oil with medically uncontrolled secondary glaucoma following intravitreal silicone oil injection. METHODS: Medical records of 11 eyes of 11 patients who underwent TSCPC for medically uncontrolled glaucoma without pupillary block following intravitreal silicone oil injection for complicated retinal detachment were reviewed retrospectively. In all cases, intravitreal silicone oil was not removed for fear of retinal redetachment. Diode laser contact TSCPC was performed at a power of 1.5-2.5 W, for a duration of 2 seconds, and with 20-27 applications. IOP, number of glaucoma medications, and success rate were evaluated. RESULTS: After a mean follow up period of 52.5 (SD 8.2) (range 42-68) weeks, the mean pretreatment level of IOP, 43.0 (14.4) (26-67) mmHg, had fallen to 14.5 (4.3) (7-20) mm Hg (p=0.003). The number of glaucoma medications was reduced from 2.6 (0.8) to 0.6 (1.0) (p= 0.005). Qualified success was achieved in nine eyes (81.8%) and complete success in six (54.5%). After TSCPC, patients' retinal status had not changed. CONCLUSION: Patients with medically uncontrolled glaucoma secondary to intravitreal silicone oil injection can be treated with TSCPC in spite of the retained intravitreal silicone oil.

Adult↗

PubMed1999

Indirect modulation of dopamine D2 receptors as potential pharmacotherapy for schizophrenia: I. Adenosine agonists.

OBJECTIVE: To review preclinical and clinical information related to pharmacologic modulation of dopamine D2 receptors as potential novel antipsychotic therapy. Specifically, to summarize the data that suggest a modulatory action of adenosine A2A receptors on dopamine D2 receptors and, therefore, a possible rational role of adenosine A2A agonists as novel antipsychotic agents. DATA SOURCES: Primary and review articles were identified by MEDLINE search (from 1966 to May 1998) and through secondary sources. STUDY SELECTION AND DATA EXTRACTION: All of the articles identified from the data sources were evaluated and all information deemed relevant was included in this review. DATA SYNTHESIS: For all of the older and many of the newer antipsychotic agents, there is a strong correlation between clinical antipsychotic activity and affinity for dopamine D2 receptors. Unfortunately, dopamine D2 receptors are believed to also be involved in the adverse effect profile of these agents. The indirect modulation of dopamine D2 receptors, rather than direct block, might produce antipsychotic effects without the usual adverse reactions. Several lines of evidence from animal studies suggest that the use of selective A2A agonists might represent a novel approach to the treatment of psychoses. CONCLUSIONS: Dopamine receptor modulation might represent a novel antipsychotic approach or adjunct therapy. The data regarding adenosine agonists (particularly selective A2A receptor agonists) are inconclusive at the present time. Direct clinical demonstration of effectiveness is required.

Adenosine↗

PubMed1999

Prolonging cell-free protein synthesis with a novel ATP regeneration system.

A new approach for the regeneration of adenosine triphosphate (ATP) during cell-free protein synthesis was developed to prolong the synthesis and also to avoid the accumulation of inorganic phosphate. This approach was demonstrated in a batch system derived from Escherichia coli. Contrary to the conventional methods in which exogenous energy sources contain high-energy phosphate bonds, the new system was designed to generate continuously the required high-energy phosphate bonds within the reaction mixture, thereby recycling the phosphate released during protein synthesis. If allowed to accumulate, phosphate inhibits protein synthesis, most likely by reducing the concentration of free magnesium ion. Pediococcus sp. pyruvate oxidase, when introduced in the reaction mixture along with thiamine pyrophosphate (TPP) and flavin adenine dinucleotide (FAD), catalyzed the generation of acetyl phosphate from pyruvate and inorganic phosphate. Acetyl kinase, already present with sufficient activity in Escherichia coli S30 extract, then catalyzed the regeneration of ATP. Oxygen is required for the generation of acetyl phosphate and the H(2)O(2) produced as a byproduct is sufficiently degraded by endogenous catalase activity. Through the continuous supply of chemical energy, and also through the prevention of inorganic phosphate accumulation, the duration of protein synthesis is extended up to 2 h. Protein accumulation levels also increase. The synthesis of human lymphotoxin receives greater benefit than than that of chloramphenicol acetyl transferase, because the former is more sensitive to phosphate inhibition. Finally, through repeated addition of pyruvate and amino acids during the reaction period, protein synthesis continued for 6 h in the new system, resulting in a final yield of 0.7 mg/mL.

Adenosine Triphosphate↗

PubMed1997

Effects of 0.5% apraclonidine on optic nerve head and peripapillary retinal blood flow.

AIMS: To examine the effects of 0.5% apraclonidine on optic nerve head (ONH) and peripapillary retinal blood flow by scanning laser Doppler flowmetry (SLDF). METHODS: ONH and peripapillary retinal blood flow of 17 healthy subjects were measured by SLDF before and 1 hour and 3 hours after unilateral administration of 0.5% apraclonidine. The fellow eyes were treated with balanced salt solution and the examiners were masked as to which eye was treated with apraclonidine. On each occasion, three scans were obtained and haemodynamic variables (volume, flow, and velocity) were analysed at eight locations, four in the neural rim and four in the peripapillary retina, avoiding ophthalmoscopically visible vessels. The statistical significance of changes from the baseline value of variables and the differences in the measured quantities between apraclonidine treated eyes and fellow eyes at each time point were evaluated using Wilcoxon signed rank test. RESULTS: The intraocular pressure was reduced significantly in apraclonidine treated eyes by 15.0% (p = 0.001) at 1 hour and 30.0% (p = 0.000) at 3 hours after administration. In the volume, flow, or velocity of ONH and peripapillary retinal blood flow, there were no significant changes from the baseline values at 1 hour and 3 hours after apraclonidine administration in either apraclonidine treated eyes (p > 0.4) or fellow eyes (p > 0.2). Also, no significant differences were found in the measured quantities between apraclonidine treated eyes and fellow eyes at each time point (p > 0.1). CONCLUSION: A single dose of topical apraclonidine 0.5% in healthy subjects does not have adverse effects on the ONH and peripapillary retinal blood flow.

Adrenergic alpha-Agonists↗

PubMed1997

Short-term change of optic nerve head topography after trabeculectomy in adult glaucoma patients as measured by Heidelberg retina tomograph.

Using Heidelberg Retina Tomograph (HRT, Heidelberg Engineering, Heidelberg, Germany) we investigated whether reversal of glaucomatous optic disc cupping occurs in adult glaucoma patients following intraocular pressure (IOP) reduction by trabeculectomy, and whether topographic change in the optic disc differs according to region. Thirteen eyes of 13 glaucoma patients in whom IOP reduction was 25% or more at postoperative follow-up of 2 months were enrolled in the study. Cup/disc area ratio had decreased significantly, while rim area and rim volume showed significant increases (p < 0.05, Wilcoxon signed rank test). Among the optic disc sectors, rim area in the superior and inferior quadrants, especially in the superotemporal and inferotemporal octant, had increased significantly. The decrease in maximum cup death correlated significantly with the recent IOP reduction (r = 0.698, p = 0.016). Reversal of glaucomatous disc cupping after IOP reduction following trabeculectomy in adult patients as confirmed by HRT. Furthermore, the regions of selective reversal in the superior and inferior quadrants coincided with those parts of the optic nerve head in which early functional and structural glaucomatous damage has been known to occur.

Adult↗

PubMed1997

Hydroxyapatite implantation with scleral quadrisection after evisceration.

BACKGROUND AND OBJECTIVES: In contrast to the literature on enucleation, reports of hydroxyapatite (HA) implantation during evisceration are limited; however, those that have been published mention the high HA exposure rate. The authors examined the scleral quadrisection procedure to evaluate its effect on cosmetic appearance and the prevention of HA exposure after evisceration. PATIENTS AND METHODS: The authors analyzed the surgical outcomes of 17 patients who had undergone an HA implantation with scleral quadrisection after evisceration between November 1994 and November 1995. RESULTS: In each case, the authors were able to use HA implants of 18 mm or more. During follow-up (average 10.7 months), there were no cases of conjunctival erosion, HA exposure, implant migration, significant enophthalmos, or superior sulcus deformity. All of the patients, 7 of whom had a ball- and-socket prosthesis, were satisfied with their cosmetic appearance and prosthetic motility. More than 11 weeks after evisceration, all 10 studied patients had complete, round uptakes with orbital bone SPECT (single photon emission computed tomography). CONCLUSION: For good cosmetic appearance and for the prevention of implant exposure, scleral quadrisection is a safe and effective procedure for HA implantation after evisceration.

Adolescent↗

PubMed1996

A highly efficient cell-free protein synthesis system from Escherichia coli.

We modified a cell-free coupled transcription/translation system from Escherichia coli with the T7 phage RNA polymerase, and achieved a productivity as high as 0.4 mg protein/ml reaction mixture. First, we found that the optimal concentrations of phosphoenolpyruvate and poly(ethylene glycol) are interdependent; higher concentrations of the former should be used at higher concentrations of the latter. Second, the use of a condensed 30000 x g cell extract, in place of the conventional one, significantly increased the initial rate of protein synthesis. This phenomenon was demonstrated to be due to a reason other than elimination of inhibitory molecule(s) from the extract. For this system with the condensed extract, the phosphoenolpyruvate and poly(ethylene glycol) concentrations were again co-optimized, resulting in production of chloramphenicol acetyltransferase at a productivity of 0.3 mg/ml. Finally, the productivity was further increased up to 0.4 mg/ml, by supplementation of the pool of amino acids. This improved cell-free protein synthesis system is superior in productivity to any other cell-free systems reported so far, including the continuous-flow cell-free system.

Cell-Free System↗

PubMed1996

Imaging in acquired immune deficiency syndrome dementia complex (AIDS dementia complex): a review.

1. Since 1986, the AIDS dementia complex has been recognized increasingly as a significant sequela of HIV infection. Though the pathogenesis remains poorly characterized and the diagnosis is one of exclusion, research utilizing various imaging techniques has resulted in greater understanding of the progressive character of ADC. 2. CT and MR studies have revealed general atrophy, atrophy of the basal ganglia, and white matter lesions that appear to increase in severity with progression of HIV infection. 3. CT and MR are relatively insensitive to the presence of clinical dementia, neurological signs, or positive findings on neuropsychological tests. In addition, they show poor correlation with histopathologic findings. 4. PET, SPECT, and MRS show the greatest sensitivity to changes wrought by primary HIV infection of the CNS and thus the greatest potential for early diagnosis of ADC. 5. PET, SPECT, and MRS show involvement of the basal ganglia, bloodflow abnormalities, and metabolite disturbances in HIV-seropositive subjects without findings on examination or neuropsychological tests.

AIDS Dementia Complex↗

PubMed1996

Magnetic resonance imaging of Alzheimer's disease.

1. Although dementia is caused by a heterogeneous group of diseases and pathologic states, Alzheimer's disease is the largest cause, estimated to account for 50 to 75% of all dementias. 2. Unfortunately, confirmation of Alzheimer's disease (AD) requires postmortem histologic confirmation; clinical diagnosis prior to death remains one of exclusion. 3. A large number of structural and volumetric MRI studies have noted anatomic and structural changes accompanying AD, including variable degrees of general cortical atrophy. 4. A classic feature reported by many MRI studies is hippocampal and temporal lobe atrophy. 5. White matter hyperintensities on MRI are common, especially in late onset AD although their significance is still controversial. 6. This article reviews the contribution of magnetic resonance to imaging the neuropathologic changes of AD, discussing both advantages and limitations, and summarizing the major findings.

Alzheimer Disease↗

PubMed1996

Relationship between optic nerve head parameters of Heidelberg Retina Tomograph and visual field defects in primary open-angle glaucoma.

To investigate the correlation between optic nerve head configuration and visual field defects, optic nerve head analysis using confocal scanning laser tomography (Heidelberg Retina Tomograph, HRT) and automated static threshold perimetry using a Humphrey Field Analyzer (program C30-2) were performed on 81 eyes of 44 primary open-angle glaucoma (POAG) patients. The optic nerve head parameters-rim area, rim volume, mean retinal nerve fiber layer thickness, height variation contour, and third moment in contour were measured by HRT and were analyzed for correlation with visual field indices-mean deviation, and corrected pattern standard deviation. All optic nerve head parameters except HVC correlated significantly with the visual field indices; the highest correlation was between rim area and mean deviation (r = 0.6172, p < 0.00001). The rim area of the superior and inferior quadrants correlated significantly with the visual field defects in corresponding sectors. Structural optic disc measurements by HRT correlated significantly with functional optic nerve head damage in POAG.

Female↗

PubMed1996

Topical cyclosporine and glaucoma drainage implant surgery in rabbits.

BACKGROUND AND OBJECTIVE: To assess the effect of topical cyclosporine on the function of filtering blebs and fibroblast proliferation after glaucoma drainage implant surgery in rabbits. MATERIALS AND METHODS: Intraocular pressure, flow resistance through the implant capsule, and fibroblast density in the capsule were compared between 12 eyes that received implant surgery only (group A) and 11 eyes treated with topical 2% cyclosporine twice a day for 2 weeks after implant surgery (group B). RESULTS: There were significantly larger decreases in intraocular pressure at 1,2,4, and 8 weeks postoperatively in group B than in group A (n = 12, P < .05). Flow resistance was significantly lower in group B than in group A (n = 5, P < .05) at 8 weeks postoperatively. Fibroblast density was not significantly different between the two groups (n = 3, P > .05). CONCLUSION: These results suggest that topical 2% cyclosporine may enhance the effectiveness of glaucoma drainage implant surgery.

Administration, Topical↗

PubMed1996

Evaluation of pupillary block component in angle-closure glaucoma.

To evaluate the amount of the pupillary block component in primary angle-closure glaucoma, the dark-room prone-position test was carried out in 30 eyes of 20 primary angle-closure glaucoma patients, before and one month after argon laser iridotomy. The pupillary block component in the prone position (5.8 +/- 5.6 mmHg), which is the amount of reduction in IOP rise in the post-laser dark-room prone-position test, composed 67.8% of the IOP rise in the pre-laser dark-room prone-position test (8.6 +/- 5.6 mmHg). The amount of the pupillary block component correlated significantly with the IOP rise in the pre-laser dark-room prone-position test (r = 0.880, P < 0.001). The amount of the non-pupillary block component was relatively constant and correlated poorly with the IOP rise in the pre-laser dark-room prone-position test (r = 0.163, P = 0.386). The pupillary block component was significantly larger than the non-pupillary block component in the eyes with an IOP rise of > or = 7 mmHg in the pre-laser dark-room prone-position test (P < 0.01). The dark-room prone-position test could be useful in evaluating the pupillary block component in angle-closure glaucoma eyes and helpful in making a decision for laser iridotomy.

Adult↗

PubMed1995

Aqueous shunts: single-plate Molteno vs ACTSEB.

A retrospective study was done to compare the results of the single-plate Molteno implant surgery with those of the anterior chamber tube shunt to an encircling band procedure in eyes with refractory glaucoma. Both Molteno implant and anterior chamber tube shunt to an encircling band are made of silicone. There were 19 eyes in the Molteno group, 17 eyes in the anterior chamber tube shunt to an encircling band group, with at least 6 months of follow-up. Preoperative intraocular pressure in the Molteno group and anterior chamber tube shunt to an encircling band group was 47.5 +/- 11.4 and 46.5 +/- 10.3 mmHg, respectively. Intraocular pressure at 6 months postoperatively was 20.4 +/- 15.1 and 15.5 +/- 10.4 mmHg, respectively. The difference in pressure reduction between the two groups was not significant statistically. Serious complication rate for 6 months was 11% and 47%, respectively.

Anterior Chamber↗

PubMed1994

The effects of intraoperative mitomycin-C or 5-fluorouracil on glaucoma filtering surgery.

We compared the success rate of filtering surgery of a single 5-minute intraoperative application of mitomycin-C (MMC) or 5-fluorouracil (5-FU). Animal experiment and clinical study were done. In animal study, thirty pigmented rabbits (60 eyes) weighing 2.0 to 2.5 Kg were enrolled. We divided into 4 groups, such as BSS, 5-FU 50 mg/ml, MMC 0.2 mg/ml and MMC 0.4 mg/ml subconjunctival soaked group. Each group consisted of 15 eyes. In each group, 10 eyes was for examination of bleb survival and complications, 3 eyes for light microscopic examination and 2 eyes for electron microscopic examination. Bleb was survived 6.1 days (3 to 13 days) for BSS treated group, 16.3 days (9 to 23 days) for 5-FU 50mg/ml treated group, 32.7 days (17 to 55 days) in MMC 0.2 mg/ml treated group, and 64.4 days (49 to 84 days) in MMC 0.4 mg/ml treated group. Duration of bleb survival was significantly prolonged in 5-FU, MMC 0.2 mg/ml and MMC 0.4 mg/ml group respectively. In clinical study, fifty-five eyes of 40 patients were enrolled. 29 eyes of 21 patients were treated with MMC 0.2 mg/ml and 26 eyes of 19 patients were treated with 5-FU 50 mg/ml. The success rate was 89.7% in MMC 0.2 mg/ml treated group and 84.6% in 5-FU 50 mg/ml treated group at postoperative 3 months, and postoperative 6 months 89.7% in MMC 0.2 mg/ml treated group and 76.9% in 5-FU 50 mg/ml treated group. There was no statistical significance at postoperative 3 months (P > 0.05), but statistical significance at postoperative 6 months (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Purification of a novel phospholipase C isozyme from bovine cerebellum.

An isozyme of phosphoinositide-specific phospholipase C (PLC) was purified to near homogeneity from bovine cerebellum by a combination of several column chromatography procedures. Approximately 80 micrograms of pure enzyme were obtained from 4 kg of bovine cerebellum, with a final specific activity of 7.5 mumol/min/mg protein in the presence of 0.1% deoxycholate. The enzyme is specific for phosphatidylinositol and phosphatidylinositol 4,5-bisphosphate but does not hydrolyze phosphatidylcholine. The molecular weight of the enzyme determined by SDS-polyacrylamide gel electrophoresis is approximately 97,000. Polyclonal antibodies to previously characterized PLC isozymes, PLC-beta 1, -beta 2, -gamma 1, -gamma 2, and - delta 1, did not cross-react with the purified cerebellar enzyme. Moreover, polyclonal antibodies prepared against the cerebellar enzyme did not react with purified PLC-beta 1, -beta 2, -gamma 1, -gamma 2, or -delta 1. However, the cerebellar enzyme was recognized by two antibodies generated against peptide sequences common to mammalian PLC isozymes. Comparison of partial amino acid sequences of the purified cerebellar enzyme with the deduced amino acid sequence of each known PLC isozyme shows that the cerebellar enzyme is a novel PLC, which could be classified as a PLC-beta-type isozyme. Thus, we have designated this enzyme PLC-beta 4.

Amino Acid Sequence↗

PubMed1993

Relationship of hemoglobin level and duration of hospitalization after total hip arthroplasty: implications for the transfusion target.

We analyzed the relationship of hemoglobin level and duration of hospitalization of patients who underwent primary cemented total hip arthroplasty for degenerative joint disease at our institution. Retrospectively, we reviewed the medical records of 332 patients treated during a 16-month period (May 6, 1989, to Aug. 20, 1990). The following variables were analyzed: number of postoperative days to dismissal from the hospital, level of hemoglobin preoperatively and at dismissal, decrease in hemoglobin level from preoperatively to time of dismissal, patient age, surgeon, and blood products transfused. No correlation was found between level of hemoglobin at dismissal, preoperative hemoglobin level, or decrease in hemoglobin concentration from preoperatively to time of dismissal and number of days to dismissal from the hospital. Advanced age was associated with a longer hospital stay. A slight but statistically significant difference was noted in duration of hospitalization among patients operated on by different surgeons. Patients who received both autologous and homologous blood required more transfusion (3.8 units) and had a longer hospital stay (10.7 days) than did patients who received autologous blood only (2.4 units and 9.5 days) or homologous blood only (2.6 units and 10.2 days). We conclude that variation in hemoglobin levels among patients in our study was unrelated to duration of hospitalization. This finding suggests that transfusion of autologous or homologous blood to achieve a higher hemoglobin level (higher transfusion target) solely for shortening hospital stay is unwarranted.

Age Factors↗

PubMed1993

Effects of topical mitomycin C on glaucoma filtration surgery.

We studied the efficacy and safety of using topical mitomycin C (MMC) as an adjunct to glaucoma filtration surgery. Trabeculectomy was performed in 23 eyes of 19 patients with poor surgical prognosis. After the preparation of a scleral flap, 0.2 mg or 0.4 mg/ml MMC was applied to the exposed tissue for 5 minutes. The wound was then irrigated with 250ml of normal saline. The mean follow-up period was 7.8 months. Preoperative mean intraocular pressure (IOP) was 33.8mmHg, and the mean IOPs on 1, 3, 6, and 12 months after operation were 10.3, 12.5, 12.4 and 12.3mmHg, respectively. At postoperative 12 months, 74.7% achieved an IOP of less than or equal to 20mmHg without any antiglaucoma medication. There were early postoperative complications of aqueous leaking from conjunctival wounds in 3 eyes (13.0%), shallow anterior chamber in 2 eyes, and hyphema in one eye and one eye had long-term hypotony lasting more than 3 months. Although MMC is simple to use, it is a potent adjunct to glaucoma filtration surgery, more work should follow to determine the mechanism of action, indications, dosage and optimal exposure time of MMC.

Administration, Topical↗

PubMed1993

Effects of sodium hyaluronate on filtration bleb in rabbits.

Sodium hyaluronate can be used during a trabeculectomy to prevent early postoperative hypotony and shallow anterior chamber. To determine its long-term effect on the outcome of filtration surgery, fifteen rabbits underwent a posterior-lip sclerectomy in both eyes. Into their right eyes 0.2ml sodium hyaluronate, and into left eyes 0.2ml balanced salt solution were injected intracamerally. Gross and histopathological differences of bleb were observed. There was no statistically significant difference in longevity of the filtration bleb.

Animals↗