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Biomedical subjects

D H Shin

Publications and source records attributed to D H Shin.

At least 163 records · Page 9Linked to original sources
PubMed1996

Relationship between optic disc cupping change and intraocular pressure control in adult glaucoma patients.

BACKGROUND: Until recently, there has been a paucity of quantitative evidence for intraocular pressure (IOP)-dependent optic disc cupping change in adult glaucoma patients. Therefore, we investigated the relationship between optic disc cupping change and IOP control. METHODS: The study involved 78 eyes of 78 randomly selected adult patients with early to moderate chronic open-angle glaucoma (CO-AG), treated on various therapeutic regimens, who had had two consecutive successful optic disc analyses with the Rodenstock Optic Nerve Head Analyzer 15.8 +/- 14.8 weeks apart. RESULTS: The mean initial IOP of 27 eyes (34%) with cupping reversal did not differ from that of 17 eyes (22%) demonstrating progressive deterioration (29.2 +/- 8.8 vs 26.2 +/- 6.1 mmHg, P > 0.5), but the reversal group did have a significantly greater mean IOP decrease than the progression group (-10.8 +/- 7.9 vs-1.0 +/- 7.7 mmHg, P < 0.001) and significantly lower mean final IOP (18.3 +/- 6.1 vs 25.2 +/- 7.9 mmHg, P < 0.003). CONCLUSION: A decrease of optic disc cupping is more likely with a greater IOP reduction and a lower final IOP, and an increase of cupping is more likely with less or no IOP reduction and a higher final IOP.

Adult↗
PubMed1996

Effect of topical anti-inflammatory treatment on the outcome of laser trabeculoplasty. The Fluorometholone-Laser Trabeculoplasty Study Group.

PURPOSE: We investigated the effect of anti-inflammatory treatment on the outcome of argon laser trabeculoplasty. METHODS: In this multicenter, double-masked, randomized, placebo-controlled, parallel comparison study, 140 chronic open-angle glaucoma patients received either 0.25% fluorometholone or vehicle four times a day unilaterally, beginning 24 hours before and continuing one week after argon laser trabeculoplasty. The laser surgeon placed 50 to 60 burns over the inferior 180 degrees of the trabecular meshwork. The patients were followed up frequently for five weeks after the procedure. RESULTS: Following argon laser trabeculoplasty, signs of anterior chamber inflammation were significantly lower in the fluorometholone group. However, there was no significant difference between the fluorometholone and the vehicle groups in the incidence of increased intraocular pressure in the immediate post-argon laser trabeculoplasty period. Intraocular pressure decreased significantly in both groups from day 1 throughout the follow-up period. A significant between-group difference in intraocular pressure decrease was found only at week 5 (7.83 +/- 6.27 [S.D.] mm Hg for the fluorometholone group vs 6.63 +/- 5.79 mm Hg for the vehicle group, P = .046). No drug-related clinically significant adverse events were observed. CONCLUSIONS: Use of fluorometholone is effective in attenuating inflammation and has no clinically significant impact on the outcome of argon laser trabeculoplasty or on the incidence of intraocular pressure spikes during the immediate post-argon laser trabeculoplasty period.

Administration, Topical↗
PubMed1996

Primary glaucoma triple procedure with or without adjunctive mitomycin. Prognostic factors for filtration failure.

PURPOSE: The prerequisite for selective use of adjunctive mitomycin C (MMC) in primary glaucoma triple procedure (PGTP) is a better understanding of the prognostic factors. Therefore, the authors carried out the current study on the outcome of PGTP with and without adjunctive MMC to determine the prognostic factors for filtration failure of PGTP. METHODS: The study patients consisted of 174 consecutive primary open-angle glaucoma (POAG) patients undergoing PGTP. They were assigned randomly to either no adjunctive MMC (93 eyes of 93 patients) or adjunctive subconjunctival MMC (81 eyes of 81 patients) during the PGTP. After surgery, the patients were examined at regular intervals for visual acuity, intraocular pressure (IOP) control, medical therapy requirements, and complications. Filtration failure was determined according to two different criteria: (1) a less stringent set of criteria (criterion I) and (2) a more stringent set of criteria (criterion II). RESULTS: There were no statistically significant differences between the groups with and without adjunctive MMC with respect to postoperative IOP, number of medications, and visual acuity outcome during mean follow-up (+/- standard deviation) of 25.1 +/- 5.5 months (P > 0.05 for each). However, there were prognostic factors for filtration failure in the control group but not in the MMC group. Black race, diabetes mellitus, preoperative IOP greater than or equal to 20 mmHg, and number of preoperative medications greater than two were found to be significant prognostic factors for filtration failure by criterion I. Black race, preoperative IOP greater than or equal to 20 mmHg and number of preoperative medications greater than 1 were significant prognostic factors for filtration failure by criterion II. CONCLUSION: There was no statistically significant difference in the overall outcome of PGTP between control and MMC groups of nonselected patients with primary open-angle glaucoma. Black race, diabetes mellitus (by criterion I only), preoperative IOP greater than or equal to 20 mmHg, and number of preoperative medications greater than 2 (by criterion I) or greater than 1 (by criterion II) were found to be significant independent prognostic factors for filtration failure of PGTP without adjunctive MMC but no with adjunctive MMC. The use of adjunctive subconjunctival MMC in PGTP may have to be selective, primarily in those patients with primary open-angle glaucoma with one or more of the prognostic factors for filtration failure.

Aged↗
PubMed1996

p172: An alveolar type II and Clara cell specific protein with late developmental expression and upregulation by hyperoxic lung injury.

The epithelium of the alveolus and distal airway meets unique requirements, functioning as a gas exchange membrane and barrier to alveolar flooding by vascular contents as well as to bloodstream contamination by airborne toxins and pathogens. Gene products specifically expressed by this epithelium, notably the surfactant apoproteins, have had important clinical application. No cell surface antigen specific for alveolar type II and Clara cells has been described. We report the biochemical characterization, tissue and developmental expression, and upregulation by injury of a 172 kD protein recognized by a monoclonal antibody, 3F9, synthesized in response to immunization with freshly isolated rat alveolar type II cells. p172 is expressed in a polarized fashion by the apical surface of rat alveolar type II and Clara cells. An immunohistochemical survey of various rat tissues and organs reveals lung specificity. p172 is first detectable in rare epithelial cells at 19 days of gestation, a time when the fully differentiated alveolar type II cell is identified by the first detection of lamellar bodies. There is a dramatic increase in p172 expression just prior to birth. Hyperoxic lung injury results in increased expression of p172. The upregulation of p172 by hyperoxia and its cell-specific expression suggests an important adaptive function.

Animals↗
PubMed1996

An immunohistochemical localization of transferrin binding protein in the chicken respiratory tract.

Transferrin binding protein (TfBP), a glycoprotein, is originally purified from the chicken oviduct. Recently, TfBP has been revealed as a novel transferrin binding protein, structurally related to the chicken heat shock protein 108. The physiological function of this protein, however, has not yet been established. Antiserum to TfBP was found to stain selectively transferrin- and iron-rich oligodendrocytes of the normal chicken brain, suggesting a role for this protein in connection with transferrin and iron storage in these cells. In this study, we further demonstrate a TfBP-immunoreactivity in the chicken respiratory tract mucosa, where transferrin is known to be present and have antioxidant and antibacterial properties. A strong TfBP immunoreactivity was revealed in certain regions of the respiratory tract. In the trachea and bronchi, TfBP-immunoreactive product was localized specifically to the mucous gland cells, whereas ciliated epithelial cells were negative. In the lung, TfBP immunoreactivity was mostly confined to the parabronchi and atria. The immunoreactive products were found in the cytoplasm of the epithelial cells lining the parabronchial and atrial walls. These findings suggest that the presence of TfBP in the airway mucosa may be a necessary condition for transferrin concentration in the extracellular milieu of the respiratory tract.

Animals↗
PubMed1996

Incidence of ptosis following trabeculectomy: a comparative study.

The occurrence of ptosis after trabeculectomy has been a common postoperative complication. Many factors have been implicated in the development of postoperative ptosis. The purpose of this study was to investigate the incidence of ptosis following trabeculectomy and whether or not it was influenced by combined cataract surgery, type of conjunctival flap, and previous intraocular surgery. We reviewed 386 eyes of 386 patients who underwent either trabeculectomy alone or trabeculectomy combined with cataract surgery, with greater than 6 month follow-up. Ptosis occurred in 10.7% (18 of 150 eyes) after trabeculectomy alone and in 12.7% (30 of 236 eyes) after trabeculectomy with combined cataract surgery (p = 0.96). The incidence of ptosis was 12.3% (10 of 81 eyes) after limbus-based conjunctival flap and 12.5% (38 of 305 eyes) after fornix-based conjunctival flap (p = 0.98). There was no significant difference in the incidence of ptosis between primary surgery eyes (12.5%, 34 of 273 eyes) and secondary surgery eyes (12.4%, 14 of 113 eyes) (p = 0.97). The incidence of ptosis after trabeculectomy was about 12% overall and not significantly influenced by combined cataract surgery, type of conjunctival flap or previous ocular surgery.

Adolescent↗
PubMed1996

Cyclin D1 protein expression in lung cancer.

Cyclin D1, a G1 cyclin, has been implicated in the oncogenesis of various types of malignancies via deregulation of cell cycles. Amplification of cyclin D1 as a part of 11q13 amplicon has been reported in lung cancer as well as a subset of carcinomas arising from various organs including breast, head and neck, and esophagus. In addition to its role as an oncogene, several recent studies have suggested that amplification is indicative of poor prognosis. In this study we examined the cyclin D1 protein expression in 102 consecutive cases of lung cancers using the microwave enhanced immunohistochemical staining method and correlated the data with the histologic subtype and grade, Ki-67 (MIB-1) labeling index, and survival. Nuclear positive staining was observed in 18 cases (18 %) of lung cancers. Although squamous cell carcinoma demonstrated a higher rate of expression (12 /58, 21%), three of 33 adenocarcinomas (9%) revealed overexpression and both adenocarcinoma and squamous cell carcinoma components within the adenosquamous carcinoma showed nuclear staining. There was no correlation between cyclin D1 overexpression and histologic grade, Ki-67 (MIB-1) labeling index, and survival. These observations indicate that cyclin D1 protein overexpression might be implicated in the oncogenesis of the various histologic types of non-small cell lung carcinomas but it has no usefulness as a prognostic marker.

Cyclin D1↗
PubMed1996

Use of fascia lata in revision of filtration surgery.

PURPOSE: To report on a successful use of fascia lata patch graft in revision of trabeculectomy for management of severe chronic discomfort associated with an exuberant conjunctival filtering bleb over a very nasal filtering site. METHODS: After dissecting a conjunctival flap over the area of the trabeculectomy at the nasal quadrant, fascia lata patch graft was sutured in place over the filtering site when primary suture closure was found ineffective. A new trabeculectomy was performed temporal and superior to the old site, and the conjunctival wound closed watertight. RESULTS: The fascia lata patch graft was effective in closing the filtration over the old trabeculectomy site at the nasal quadrant, and a new filtering bleb developed superiorly over the new trabeculectomy site, resulting in sustained IOP control. CONCLUSION: Fascia lata patch graft was effective in revision of trabeculectomy.

Fascia Lata↗
PubMed1995

High-resolution crystal structure of the non-specific lipid-transfer protein from maize seedlings.

BACKGROUND: The movement of lipids between membranes is aided by lipid-transfer proteins (LTPs). Some LTPs exhibit broad specificity, transferring many classes of lipids, and are termed non-specific LTPs (ns-LTPs). Despite their apparently similar mode of action, no sequence homology exists between mammalian and plant ns-LTPs and no three-dimensional structure has been reported for any plant ns-LTP. RESULTS: We have determined the crystal structure of ns-LTP from maize seedlings by multiple isomorphous replacement and refined the structure to 1.9 A resolution. The protein comprises a single compact domain with four alpha-helices and a long C-terminal region. The eight conserved cysteines form four disulfide bridges (assigned as Cys4-Cys52, Cys14-Cys29, Cys30-Cys75, and Cys50-Cys89) resolving the ambiguity that remained from the chemical determination of pairings in the homologous protein from castor bean. Two of the bonds, Cys4-Cys52 and Cys50-Cys89, differ from what would have been predicted from sequence alignment with soybean hydrophobic protein. The complex between maize ns-LTP and hexadecanoate (palmitate) has also been crystallized and its structure refined to 1.8 A resolution. CONCLUSIONS: The fold of maize ns-LTP places it in a new category of all-alpha-type structure, first described for soybean hydrophobic protein. In the absence of a bound ligand, the protein has a tunnel-like hydrophobic cavity, which is large enough to accommodate a long fatty acyl chain. In the structure of the complex with palmitate, most of the acyl chain is buried inside this hydrophobic cavity.

Amino Acid Sequence↗
PubMed1995

The efficacy of apraclonidine as an adjunct to timolol therapy. Apraclonidine Adjunctive Therapy Study Group.

OBJECTIVE: To compare the intraocular pressure (IOP) lowering efficacy of 0.5% and 1.0% apraclonidine hydrochloride when used adjunctively with 0.5% timolol maleate in 129 patients. DESIGN: A multicenter, randomized, double-masked clinical trial. Adult patients of either sex diagnosed as having either open-angle glaucoma or ocular hypertension were enrolled in the study. Patients using only 0.5% timolol maleate twice daily for at least 4 weeks and who had 8 AM IOPs of at least 22 mm Hg and no greater than 30 mm Hg 12 hours after dosing were eligible for the study. After 8 AM baseline IOPs were obtained while patients were taking timolol only, they were then randomized to receive either 0.5% or 1.0% apraclonidine twice daily in addition to their timolol. Intraocular pressures were measured at 8 AM (before morning dosing) and at 11 AM (3 hours after dosing) on days 14 and 90 and at 8 AM only on day 45. RESULTS: Both concentrations of apraclonidine produced significant IOP reductions from baseline at all visits (P < .001). At 8 AM, after the nighttime dose, the additional mean IOP reduction from the timolol baseline ranged from 2.5 to 3.3 mm Hg (10.3% to 13.6% reduction, respectively). At 11 AM, 3 hours after the morning dose, the additional IOP reduction from the timolol baseline ranged from 4.7 to 5.2 mm Hg (20.0% to 21.7%, respectively). No difference in IOP reduction was observed between the 0.5% and 1.0% apraclonidine concentrations and no loss of IOP efficacy was observed for either concentration for the duration of the study. Sensitivity to 0.5% and 1.0% apraclonidine was observed in nine (13.8%) and 13 (20.3%) patients, respectively. Overall, therapy was discontinued owing to ocular or nonocular side effects with 0.5% and 1.0% apraclonidine in 14 (21.5%) and 16 (25%) patients, respectively. CONCLUSIONS: We believe that 0.5% apraclonidine is equally effective as 1.0% apraclonidine when used twice daily as the first adjunctive drug to timolol. The drug effect is maintained for at least 90 days.

Adrenergic alpha-Agonists↗
PubMed1995

Crystallization, molecular replacement solution, and refinement of tetrameric beta-amylase from sweet potato.

Sweet potato beta-amylase is a tetramer of identical subunits, which are arranged to exhibit 222 molecular symmetry. Its subunit consists of 498 amino acid residues (Mr 55,880). It has been crystallized at room temperature using polyethylene glycol 1500 as precipitant. The crystals, growing to dimensions of 0.4 mm x 0.4 mm x 1.0 mm within 2 weeks, belong to the tetragonal space group P4(2)2(1)2 with unit cell dimensions of a = b = 129.63 A and c = 68.42 A. The asymmetric unit contains 1 subunit of beta-amylase, with a crystal volume per protein mass (VM) of 2.57 A3/Da and a solvent content of 52% by volume. The three-dimensional structure of the tetrameric beta-amylase from sweet potato has been determined by molecular replacement methods using the monomeric structure of soybean enzyme as the starting model. The refined subunit model contains 3,863 nonhydrogen protein atoms (488 amino acid residues) and 319 water oxygen atoms. The current R-value is 20.3% for data in the resolution range of 8-2.3 A (with 2 sigma cut-off) with good stereochemistry. The subunit structure of sweet potato beta-amylase (crystallized in the absence of alpha-cyclodextrin) is very similar to that of soybean beta-amylase (complexed with alpha-cyclodextrin). The root-mean-square (RMS) difference for 487 equivalent C alpha atoms of the two beta-amylases is 0.96 A. Each subunit of sweet potato beta-amylase is composed of a large (alpha/beta)8 core domain, a small one made up of three long loops [L3 (residues 91-150), L4 (residues 183-258), and L5 (residues 300-327)], and a long C-terminal loop formed by residues 445-493. Conserved Glu 187, believed to play an important role in catalysis, is located at the cleft between the (alpha/beta)8 barrel core and a small domain made up of three long loops (L3, L4, and L5). Conserved Cys 96, important in the inactivation of enzyme activity by sulfhydryl reagents, is located at the entrance of the (alpha/beta)8 barrel.

Amino Acid Sequence↗
PubMed1995

Short-term efficacy of apraclonidine hydrochloride added to maximum-tolerated medical therapy for glaucoma. Apraclonidine Maximum-Tolerated Medical Therapy Study Group.

PURPOSE: We determined whether the addition of topical apraclonidine hydrochloride to eyes that are receiving maximal medical therapy but still have inadequate intraocular pressure control and that are scheduled to undergo surgery could adequately decrease intraocular pressure, postponing the need for further intervention. METHODS: We performed a prospective, 90-day, multicentered, placebo-controlled, double-masked parallel study. We enrolled one eye each of 174 glaucoma patients with inadequate intraocular pressure control who were on maximally tolerated medical therapy. We continued to administer maximum medical therapy for glaucoma. Study medications were either apraclonidine hydrochloride 0.5% or placebo (apraclonidine's vehicle). Patients were instructed to take the study medication every eight hours. We measured intraocular pressure, change in intraocular pressure from baseline, and the number of eyes requiring surgery after the addition of study medication. RESULTS: Fifty-two (60%) of 86 patients treated with apraclonidine maintained adequate intraocular pressure control throughout the study and avoided surgery, compared with 28 (32%) of 88 patients treated with placebo (P < .001). Apraclonidine treatment resulted in significantly more patients attaining an additional 20% reduction or more in intraocular pressure from baseline and an intraocular pressure less than or equal to 20 mm Hg (P < .05). The most common ocular complication was conjunctival hyperemia (11 of 86 patients, 12.8%). The most frequent nonocular problem was dry mouth (four patients, 4.7%). CONCLUSION: Apraclonidine appeared to be safe in all eyes and efficacious in some eyes. It significantly lowered intraocular pressure when used in combination with maximally tolerated medical therapy, which delayed or prevented further glaucoma surgery for at least 90 days in 52 (60%) of 86 treated patients.

Adrenergic alpha-Agonists↗
PubMed1995

Adjunctive mitomycin C in primary trabeculectomy in phakic eyes.

PURPOSE: The addition of antiproliferative agents, most recently mitomycin C, has improved the outcome of glaucoma filtering surgery in eyes with a high risk of surgical failure. We conducted the present study to determine whether adjunctive mitomycin C would increase the success rate of primary trabeculectomies in phakic eyes. METHODS: Thirty-three eyes of 33 consecutive patients with phakic primary open-angle glaucoma, who were predominantly black (24 black and nine white), who underwent primary trabeculectomy with adjunctive subconjunctival mitomycin C (0.5 mg/ml for three minutes) were compared with a demographically similar historical control group of 30 eyes of 30 consecutive patients (20 black and ten white) with phakic primary open-angle glaucoma, who had undergone primary trabeculectomy without an adjunctive antifibrotic agent. RESULTS: Although the mean preoperative intraocular pressures were similar in both groups (29.0 +/- 6.4 mm Hg in the mitomycin C group and 29.5 +/- 10.0 mm Hg in the control group, P = .61), the mean postoperative intraocular pressure at each follow-up period was significantly lower in the mitomycin C group than in the control group (10.3 +/- 7.1 vs 14.5 +/- 5.1 mm Hg at six months, P = .02; 10.5 +/- 4.9 vs 14.5 +/- 4.4 mm Hg at 12 months, P = .01; and 10.0 +/- 3.1 vs 17.2 +/- 3.0 mm Hg at 18 months, P = .004, respectively). The mean number of postoperative medications was also significantly lower in the mitomycin C group (0.2 +/- 0.4 vs 1.1 +/- 1.4 medications at six months, P = .007; 0.3 +/- 0.4 vs 0.9 +/- 1.1 medications at 12 months, P = .04; and 0.3 +/- 0.5 vs 1.7 +/- 1.2 medications at 18 months, P = .01, respectively). However, the mitomycin C group had a significantly higher incidence of prolonged hypotony (intraocular pressure less than 6 mm Hg) compared with the control group (15% vs 0% at nine months, P = .05). Younger age was associated with a higher incidence of persistent hypotony. CONCLUSIONS: Adjunctive subconjunctival mitomycin C (0.5 mg/ml for a three-minute exposure) in primary trabeculectomies of phakic eyes, while increasing the success rate by decreasing intraocular pressure and postoperative medications, is associated with a higher incidence of prolonged hypotony.

Adult↗
PubMed1995

Long-term results using adjunctive mitomycin C in optic nerve sheath decompression for pseudotumor cerebri.

PURPOSE: Up to 35% of patients undergoing optic nerve sheath decompression (ONSD) for pseudotumor cerebri who show initial improvement in visual function later show deterioration in visual field and acuity. Although repeat surgery can result in subsequent visual improvement, these procedures are technically difficult because of scarring and fibrosis. Attempting to improve the long-term success of ONSD, the authors sought to analyze the long-term success of ONSD by pretreating optic nerve sheaths with mitomycin C before incision. METHODS: Using a standard transconjunctival medial orbitotomy, optic nerve sheaths were exposed and treated for 5 minutes with mitomycin C (0.5 mg/ml)-soaked neurosurgical cottonoids before incision. RESULTS: Both eyes undergoing repeat ONSD with adjunctive mitomycin C had initial improvement and stable visual function for follow-up of more than 3 years. Four eyes that underwent primary ONSD all initially showed improvement in visual field. Three eyes with large cysts or fistulas remained stable. Another eye had gradual decline in visual function. Repeat ONSD in this eye showed no orbital scarring, and lysis of adhesions between dura-arachnoid and optic nerve resulted in improved, stable visual function for 31 months of follow-up. CONCLUSION: Mitomycin C appears to be a safe adjunct to ONSD in a series of six patients followed between 20 and 37 months. Fistulization and cyst formation are associated with improved visual function. Closure of cysts and fistulas may result in worsening visual function due to intersheath adhesions. Repeat surgery shows significantly less orbital scarring and allows for easier and successful repeat surgery. Adjunctive mitomycin C leads to less orbital scarring after ONSD, allowing for easier repeat surgery.

Adult↗