Biomedical subjects

Shu-Wen Chang

Publications and source records attributed to Shu-Wen Chang.

6 recordsLinked to original sources

PubMed2005

Recurrent Alcaligenes xylosoxidans keratitis.

PURPOSE: To describe a case of postkeratoplasty recurrent Alcaligenes xylosoxidans keratitis. METHODS: A 33-year-old man with a history of penetrating keratoplasty developed corneal infiltrate with intact epithelium and then was treated with broad-spectrum antibiotics. Corneal scraping was taken for microbiologic study. RESULTS: The culture result identified A. xylosoxidans, sensitive to piperacillin and ceftazidime. There were 3 recurrent episodes within 2 months after each apparent resolution achieved after the instillation of topical piperacillin (10 mg/mL). During the fourth attack, the lesion responded poorly to piperacillin and ceftazidime (25 mg/mL), so therapeutic penetrating keratoplasty was performed to eradicate the recalcitrant infection. CONCLUSIONS: A. xylosoxidans has probably been underreported as a cause of ocular infection. It does not respond to conventional antibiotic therapy and may be difficult to eradicate. Therapeutic penetrating keratoplasty might be necessary if medical treatment fails.

Abscess↗

PubMed2004

From D-glucose to biologically potent L-hexose derivatives: synthesis of alpha-L-iduronidase fluorogenic detector and the disaccharide moieties of bleomycin A2 and heparan sulfate.

A novel and convenient route for the synthesis of biologically potent and rare L-hexose derivatives from D-glucose is described. Conversion of diacetone-alpha-D-glucose (14) into 1,2:3,5-di-O-isopropylidene-beta-L-idofuranose (19) was efficiently carried out in two steps. Orthogonal isopropylidene rearrangement of compound 19 led to 1,2:5,6-di-O-isopropylidene-beta-L-idofuranose (27), which underwent regioselective epimerization at the C3 position to give the L-talo- and 3-functionalized L-idofuranosyl derivatives. Hydrolysis of compound 19 under acidic conditions furnished 1,6-anhydro-beta-L-idopyranose (35) in excellent yield, which was successfully transformed into the corresponding L-allo, L-altro, L-gulo, and L-ido derivatives via regioselective benzylation, benzoylation, triflation and nucleophilic substitution as the key steps. Applications of these 1,6-anhydro-beta-L-hexopyranoses as valuable building blocks to the syntheses of 4-methylcoumarin-7-yl-alpha-L-iduronic acid and the disaccharide moieties of bleomycin A(2) as well as heparan sulfate are highlighted.

Bleomycin↗

PubMed2004

Early corneal edema following topical application of mitomycin-C.

PURPOSE: To determine the effect of mitomycin-C (MMC) on the cornea after a single intraoperative application. SETTING: Department of Ophthalmology, Far Eastern Memorial Hospital, Ban-Chiao, Taipei, Taiwan. METHODS: Mechanical epithelium debridement of the central 10.0 mm of the cornea was performed in 63 pigmented rabbits. One group of corneas (MMC1, n = 42) was soaked with MMC 0.01% solution for 2 minutes; the second group (MMC2, n = 42) was soaked with MMC 0.02% solution for 2 minutes. Control corneas (n = 42) were soaked with balanced salt solution for 2 minutes. Changes in the central corneal thickness, clarity, epithelial defect size, endothelial cell density, and endothelial apoptosis in the 3 groups were examined on days 0, 1, 2, 3, 5, 7, and 14. RESULTS: There was a dose-dependent increase in corneal thickness, decrease in corneal clarity, and increase in endothelial apoptosis after a single intraoperative application of MMC. The endothelium was significantly swollen and became pleomorphic and polymegethic with a concomitant decrease in endothelial cell density, also in a dose-dependent manner. CONCLUSIONS: A single application of MMC on the corneal surface caused dose-dependent corneal edema and endothelial apoptosis in the rabbit model. Further clinical study of human eyes is warranted.

Administration, Topical↗

PubMed2004

Adjunctive treatment with interferon alpha-2b may decrease the risk of papilloma-associated conjunctival intraepithelial neoplasm recurrence.

PURPOSE: To report a case of bilateral papilloma virus-positive conjunctival intraepithelial neoplasm and the treatment results of using adjunctive interferon alpha-2b. METHODS: Case report and literature review. RESULTS: A 73-year-old man underwent subtotal excisional biopsy of the 270-degree gelatinous limbal lesion of the right eye to avoid creating a limbal deficiency and cicatricial change. Total excisional biopsy of the temporal elevated leukoplakic limbal lesion was performed on his left eye. Histology examination showed bilateral intraepithelial neoplasia, and human papilloma virus-16 and -18 were detected by polymerase chain reaction in both lesions. Two supplemental perilesional injections of interferon alpha-2b in the right eye were given, and the residual mass decreased in size gradually and completed clinical resolution 7 weeks following initial surgery. Although no recurrence was noticed in the right eye, recurrence of the conjunctival intraepithelial neoplasm lesion was noticed in the left eye. CONCLUSION: Adjunctive therapy might lower CIN recurrence rate, especially in extensive lesions, when surgical excision cannot ensure a tumor-free margin. Our bilateral case provided a good control example for the recurrence with or without adjunctive therapy.

Aged↗

PubMedDate not supplied

Bilateral retinal hemorrhages following automated lamellar keratoplasty.

We describe a case of bilateral multifocal retinal hemorrhages after receiving automated lamellar keratoplasty (ALK) surgery in a 32-year-old male with extremly myopic eyes. Before surgery, there was no retinal hemorrhage in routine fundus examination. This patient visited our clinic and complained of decreased vision in both eyes 2 weeks after the ALK surgery. Upon examination, his best-corrected visual acuity (BCVA) was 0.6 with -8.5-1.5 x 100(0) in the right eye and 0.9 with -4.0-2.50 x 90(0) in the left eye. Fundus examination revealed scattered multiple round focal retinal hemorrhages in both eyes. No evidence of choroidal neovascularization was noted. The retinal hemorrhages resolved 10 weeks later. The BCVA recovered to 1.0 in the right eye and 0.9 in the left eye. This case highlights the relationship between the postoperative bilateral posterior pole hemorrhages and the automated lamellar keratoplasty surgery, in which a microkeratome was used to create a corneal flap and keratectomy. Patients should be informed of this rare complication before surgery.

Adult↗

PubMedDate not supplied

Amniotic membrane transplantation for corneal perforation related to vitamin A deficiency.

Corneal perforation is one of the most vision-threatening consequences of vitamin A deficiency. Amniotic membrane transplantation was performed in a 36-year-old man who presented with bilateral corneal ulcers. There was a small, sharply demarcated superficial ulcer with crevices of surrounding keratinized epithelium converging on the ulcer and minimal infiltration at the inferior periphery of the right cornea. A 3-mm perforation on a 9 x 7-mm area of stromal melting was noticed in the left cornea. The serum vitamin A level was 14.0 microg/dL (normal, 24.57 to 105.71 microg/dL) at presentation. A biopsy of the right corneal epithelium was performed to confirm the diagnosis. Multilayered amniotic membrane transplantation with debridement of the necrotic corneal stroma was performed on the left cornea. In addition to systemic vitamin A replacement, topical antibiotics and lubricants were also administered. The cornea ulcers healed in 10 days along with the restoration of the serum vitamin A level. The visual acuity improved from 20/250 to 20/20 in the right eye and from light perception to hand movement in the left eye at 3 months. Amniotic membrane transplantation could save eyes with corneal perforation related to vitamin A deficiency before reconstructive surgeries, such as penetrating keratoplasty, are necessary.

Adult↗