No association of p53 codon 72 and p21 codon 31 polymorphisms in Taiwan Chinese patients with pterygium.
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Adult↗
Biomedical subjects
S H Tseng
Publications and source records attributed to S H Tseng.
Slipknot for scleral fixation of intraocular lenses.
We describe a simple, quick technique to construct a slipknot that can be snared around the haptic of an intraocular lens (IOL) during transscleral fixation of a posterior chamber IOL or repositioning of a dislocated IOL. An in vitro experiment showed that the time required for the slipknot method was significantly less than that for the traditional triple-knot method. An additional advantage is that the slipknot technique can be performed by a single surgeon using standard ophthalmic instrumentation. In addition, the slipknot is as secure as a triple knot.
Humans↗
Low-dose intraoperative mitomycin C as chemoadjuvant for pterygium surgery.
PURPOSE: To evaluate the efficacy and safety of low-dose intraoperative mitomycin C (MMC) during bare sclera procedure and to compare the rates of pterygium recurrence between recurrent pterygium patients treated with adjuvant MMC and those reconstructed with a conjunctival autograft. METHODS: We studied the recurrence of pterygium, 12-month pterygium-free survival rates, final appearance, and postoperative complications in 96 eyes of 92 patients who received either intraoperative 0.02% MMC for 30 seconds or conjunctival autografting after pterygium excision. Patients were divided into three groups: group 1 included 38 eyes with primary pterygium undergone intraoperative MMC; group 2, 26 eyes with recurrent pterygium treated with intraoperative MMC; and group 3, 32 eyes with recurrent pterygium treated with pterygium excision and conjunctival autografting. RESULTS: Pterygium recurred in 3 (7.9%) of 38 eyes in group 1, 5 (19.2%) of 26 eyes in group 2, and 2 (6.3%) of 32 eyes in group 3. Despite the higher recurrence rate in group 2 compared with that of group 3, the difference between the two was not statistically significant (p = 0.22). The cumulative probabilities of success were 91.6+/-4.6%, 80.8+/-7.7%, and 92.3+/-5.4% at 12 months for groups 1, 2, and 3, respectively. Final appearance of the pterygium excision area was satisfactory in nearly two-thirds of the MMC-treated patients, 71.1% and 65.4% for groups I and 2, compared to 75.1% of patients who had undergone conjunctival autografting. No patients experienced severe complications during a mean postoperative follow-up of 27.3+/-4.1 months, 29.9+/-3.9 months, and 40.9+/-19.1 months for groups 1, 2, and 3, respectively. CONCLUSIONS: A single intraoperative application of 0.02% MMC for 30 seconds after pterygium excision is associated with minimal complication and effectively reduces the recurrence rates after excision of primary or recurrent pterygium. In comparison with conjunctival autografting, low-dose application of MMC after bare sclera procedure is less efficacious in preventing recurrence of pterygium, but simpler and produces a similar proportion of patients with satisfactory final appearance.
Adult↗
Impression cytology study of conjunctival epithelial phenotypes on the healing ocular surface after pterygium excision.
PURPOSE: To compare the process of conjunctival epithelial regeneration after three types of pterygium excision procedures. METHODS: Thirty-eight patients (45 eyes) with primary pterygium were randomly assigned to a bare-sclera procedure (group 1, 15 eyes of 12 patients), bare-sclera with intraoperative mitomycin C (MMC 0.02% for 30 seconds; group 2, 15 eyes of 14 patients), or pterygium excision with conjunctival autografting (group 3, 15 eyes of 12 patients). Controls were healthy fellow eyes and seven eyes of age- and sex-matched subjects. Impression cytology was performed preoperatively, at 1 and 2 weeks, and at 1, 3, 6, and 12 months after surgery. The nucleus-to-cytoplasm (N/C) ratio of nongoblet epithelial cells and goblet cell density (GCD) in the pterygial area were calculated and compared over time across treatment groups. RESULTS: Pterygium excision wounds healed in a similar four-stage process in all groups, but at different rates and with different final results. The N/C ratio was highest at about 1 month postoperatively in groups 1 and 2 and at 2 weeks in group 3, before gradually returning to control levels. Preoperatively, the GCD in treated eyes was almost twice that in control eyes (p = 0.001) but fell to zero immediately postoperatively. Goblet cells first appeared (with the most rapidly increased density) in group 3, followed by group 1. At 12 months, the mean GCD in groups 1 and 3 were not significantly different from those in controls, whereas the mean GCD in group 2 was still less than that of control (p = 0.02). CONCLUSIONS: Healing of conjunctiva is delayed by MMC and is promoted by autografting. Even 1 year after surgery, the ocular surface remains abnormal with respect to epithelial phenotypes in eyes treated by any of the three techniques.
Adult↗
Increased immunoreactive labeling of the spinal N-methyl-D-aspartate R1 receptors after dorsal root ganglionectomy in the rats.
The N-methyl-D-aspartate (NMDA) receptor plays an important role in the development of the autotomy after dorsal root ganglionectomy (DRGn). In this study, we further investigated the expression of the NMDAR1 in the spinal cord of the rats after right DRGn by immunohistochemical analyses. Computerized densitometric analysis of the NMDAR1 immunoreactivity was done and the integrated optical density (IOD) of the superficial laminae of the dorsal horn of the spinal cord was measured. The immunoreactive labeling of the NMDAR1 was increased in the cervical spinal cord ipsilateral to the DRGn from day 5 to 14 after DRGn. The ratio of the right/left IOD of the rats receiving DRGn was significantly higher than the rats in the sham-operated group and the control group (P<0.05). The expression of the NMDAR1 increased gradually to reach the peak at day 7 after DRGn (mean right/left IOD ratio=1.52), then decreased thereafter. The increased expression of the NMDAR1 at day 7 was suppressed by MK-801 (NMDA receptor antagonist) administered immediately after DRGn, but not by normal saline or 1,2,3,4-tetrahydro-6-nitro-2, 3-dioxo-benzo[f] quinoxaline-7-sulfonamide (NBQX, non-NMDA receptor antagonist). The results indicated that the expression of the NMDAR1 in the superficial laminae of the dorsal horn of the spinal cord was increased after DRGn and the time course was compatible with the onset and development of the autotomy induced by DRGn.
Animals↗
Repositioning a subluxated sutured intraocular lens in a vitrectomized eye.
A simple, effective technique for repositioning a subluxated intraocular lens (IOL) in a vitrectomized eye is reported. A 49-year-old man who had previous pars plana vitrectomy and transscleral suture fixation of a posterior chamber (PC) IOL had lens subluxation caused by slippage of the haptic from a fixation suture. The IOL was dangling in the liquefied vitreous, preventing direct visualization of the displaced haptic. The displaced haptic was directly grasped from the opposite side with an intraocular forceps through a limbal wound and resutured to the sclera. Because only the end-grip intraocular forceps was required, this technique provides anterior segment surgeons an alternative technique of repositioning scleral-fixated PC IOLs.
Eye Injuries↗
Management of infectious scleritis after pterygium excision.
PURPOSE: We sought to describe the clinical features, responsible pathogens, management, and prognosis of infectious scleritis after pterygium excision. METHODS: A retrospective study through review of medical records of patients diagnosed with infectious scleritis after pterygium excision over a 10-year period at our institution. RESULTS: A total of 16 cases of infectious scleritis after pterygium excision was identified. Among them, eight were associated with sclerokeratitis, and six had multifocal scleral nodules with subconjunctival abscesses. Culture results were positive in 15 (93.8%) cases. Pseudomonas was isolated in 13 (81.3%) patients, fungus in three (18.8%), and two had a mixed growth (12.5%). Based on the in vitro susceptibility test, four (31%) Pseudomonas isolates were resistant to gentamicin, whereas all isolates were sensitive to amikacin. During the course of treatment, eight cases were complicated by vitreous opacity, four developed glaucoma, four had serous retinal or choroidal detachment, and two had secondary cataract. Scleral infection recurred in two patients after cessation of therapy. Among the nine patients treated with medical therapy, two eyes were enucleated, whereas only two attained a visual acuity of > or =2/200 at the end of the follow-up period. On the other hand, seven patients had combined antibiotic therapy and surgical debridement. The number of surgical debridement ranged from one to three, with an average of 1.4. In this combined-treatment group, only one patient required enucleation, and five cases attained a visual acuity of > or =2/200. The duration of hospitalization for patients with combined treatment was 21.2+/-4.8 days compared with the 28.4+/-5.0 days for those with medical treatment alone (p = 0.035). CONCLUSION: Surgical debridement in combination with appropriate antimicrobial therapy shortens the course of treatment and improves the visual outcome of severe infectious scleritis after pterygium excision.
Aged↗
Treatment of chronic pain by spinal cord stimulation.
Chronic pain after injury of the nervous system is difficult to treat. This report describes our experience in the treatment of chronic pain by spinal cord stimulation (SCS) in four patients (three men and one woman, with ages ranging from 61 to 73 yr). One patient had chronic intractable pain due to a spinal cord injury, one had post-herpetic neuralgia, one had failed back surgery syndrome, and one had brachial plexus and spinal cord injuries. A permanent spinal cord stimulator was implanted in the patient with spinal cord injuries. In the other three patients, a permanent spinal cord stimulator was implanted after a successful trial stimulation with temporarily implanted electrodes. After 19 to 25 months (mean, 21 mo) of follow-up, three patients had satisfactory improvement of pain and one patient had temporary pain relief, but pain recurred two months after implantation. One patient had recurrence of pain after migration of an electrode, and the pain-relieving effects of SCS returned after repositioning the electrode. According to this preliminary experience, SCS is effective for pain reduction in selected patients with chronic pain. Long-term follow-up is mandatory to evaluate the benefits and complications of SCS for relief of chronic pain.
Aged↗
Pediatric endogenous endophthalmitis.
Pediatric endogenous endophthalmitis is a rare disease that can cause serious ophthalmic damage. We describe two cases of pediatric endogenous endophthalmitis. The first occurred in an 8-month-old boy and the second in a 7-day-old girl. These two patients had developed pneumonia due to Pseudomonas aeruginosa infection prior to the onset of ocular symptoms. The interval between the onset of pneumonia and ocular symptoms was 1 week, but endophthalmitis was diagnosed 9 days after the onset of ocular symptoms in the first case and 3 days after the onset of ocular symptoms in the second case. The ocular manifestations included eyelid swelling, purulent discharge, redness, corneal edema, hypopyon, and poor red reflex. Despite treatment with aggressive antimicrobial therapy, both patients became totally blind with eyeball atrophy.
Endophthalmitis↗
Efficacy of media enriched with nonlactate-generating substrate for organ preservation: in vitro and clinical studies using the cornea model.
BACKGROUND: Using a rabbit cornea model, our recent study demonstrated that Chen Medium (CM), an isotonic media enriched with nonlactate-generating high-energy substrates, is very effective for organ preservation. In the present study, the efficacy of CM is further evaluated with human corneas METHODS: The effectiveness of CM and Optisol for preserving the endothelial integrity of human corneas in vitro was evaluated by scanning electron microscopy. Clinical efficacy was evaluated in a total of 83 patients: 10 patients with keratoconus grafted randomly with either CM- or Optisol-stored cornea of the same donor, and 73 patients with various conditions grafted with CM-stored corneas. After surgery, visual acuity and quality of the graft were monitored for up to 4.6 years. RESULTS: The scanning electron microscopic study revealed that after 11-day storage at 4 degrees C, the CM-stored cornea had only marginal disruptive changes, 9.4+/-1.1%, in endothelial cells, as opposed to 42.4+/-4.6% of the Optisol-stored cornea. All 78 CM-stored corneas, including 67 with 12.2- to 17.7-hr death-to-storage time, 3-7.6 days of storage time, and initial marginal quality before storage, were successfully transplanted. These grafts were thin and clear, with an excellent epithelial integrity and without significant changes in endothelial cell density. Five Optisol-stored corneas were also successfully grafted; one of them, however, was edematous for about 4 weeks, and all the grafts were slightly thicker with substantial endothelial cell loss. CONCLUSION: Using a cornea model, present and recent studies show that CM is very effective for preserving tissue viability and endothelial integrity. Previous study revealed that CM-stored tissues maintained high levels of ATP and metabolic function, with suppression of lactate formation and accumulation. Thus, these findings support the concept that preservation of tissue viability is closely associated with the ability of the tissues to retain metabolic activity, to generate ATP efficiently, and to prevent acidosis effectively during storage.
Adenosine↗
Randomized trial of intraoperative mitomycin C in surgery for pterygium.
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Chemotherapy, Adjuvant↗
Seborrheic keratosis of conjunctiva simulating a malignant melanoma: an immunocytochemical study with impression cytology.
OBJECTIVE: Seborrheic keratosis on the conjunctiva appears to have never been reported in the literature. The authors report here a well-documented case of seborrheic keratosis of conjunctiva clinically simulating a malignant melanoma. DESIGN: Case report. METHODS: A 66-year-old man presented with a juxtalimbal pigmented tumor involving the temporal conjunctiva of his left eye. Because of the rapid enlargement of the mass within a period of 5 months, a clinical diagnosis of malignant melanoma was made. Cytopathologic examinations were performed by impression cytology before the patient underwent a wide en-block excision of the tumor. MAIN OUTCOME MEASURES: Cytologic features were studied by impression cytology with periodic acid-Schiff-Papanicolaou stain. Immunochemical characteristics of tumor cells were studied by immunochemical stain of cytokeratin and HMB-45. Tumor morphology was observed by histopathologic examination. RESULTS: Impression cytology disclosed basaloid cells intermixing with squamoid cells, and these cells demonstrated positive immunoreactivity to cytokeratin and no reactivity to HMB-45. Histopathologic examination of the tumor specimen established the diagnosis of seborrheic keratosis, and the results of immunohistochemical staining were consistent with those of the impression cytology with immunocytochemical staining. CONCLUSION: The authors describe the first case report of conjunctival seborrheic keratosis and present its immunocytochemical and immunohistochemical characteristics. Such a benign lesion can clinically mimic a malignant melanoma.
Aged↗
Transscleral fixation of foldable intraocular lens after pars plana lensectomy in eyes with a subluxated lens.
Two patients had a subluxated crystalline lens: one with Marfan's syndrome and the other with traumatic cataract. A pars plana lensectomy with transscleral fixation of a foldable silicone intraocular lens rather than a conventional poly(methyl methacrylate) lens was performed. Excellent, rapid visual rehabilitation was obtained using this small incision technique.
Adult↗
Characterization of paclitaxel (Taxol) sensitivity in human glioma- and medulloblastoma-derived cell lines.
Paclitaxel (Taxol), a cytotoxic natural product that disrupts microtubule integrity, is being clinically evaluated for use against gliomas. We examined paclitaxel-induced killing in seven cell lines derived from human malignant astrocytic gliomas and medulloblastomas with the goal of characterizing range of sensitivity, contribution of P-glycoprotein 170-mediated drug efflux to resistance, and cross-resistance with alkylating agents. Exposure to paclitaxel for 8 h or less produced biphasic survival curves for all lines, with 40-75% of cells comprising a subpopulation that was 9-26 times more resistant to paclitaxel than the more sensitive fraction. Increasing exposure to 24 h eliminated the resistant subpopulation, increasing sensitivity 50- to 400-fold. The dose producing one log of kill (LD10) after a 24-h exposure ranged from 4 to 18 nM, comparable to concentrations in the cerebrospinal fluid of brain tumor patients given a 3-h infusion of paclitaxel. Concurrent exposure to paclitaxel and either nimodipine or verapamil, inhibitors of P-glycoprotein activity, did not increase sensitivity, demonstrating that the fivefold range in sensitivity was not due to P-glycoprotein-mediated drug efflux. Importantly, there was no correlation between LD10 for paclitaxel and LD10 for 1,3-bis(2-chloroethyl)-1-nitrosourea, streptozotocin, and temozolomide, indicating no expression of cross-resistance to these different classes of tumoricidal agents. Our results suggest that greater clinical efficacy of paclitaxel against malignant brain tumors may be obtained by infusion for 24 h or longer and support the use of paclitaxel in combination with alkylating agents.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Traumatic wound dehiscence after penetrating keratoplasty: clinical features and outcome in 21 cases.
PURPOSE: To describe the characteristics, causes, treatment, and outcome, particularly the fate of the intraocular implant and visual acuity, of traumatic wound dehiscence occurring in patients who had penetrating keratoplasty (PK). METHODS: Between 1989 and 1997, 21 corneal transplant patients sustained traumatic wound dehiscence and were treated at our hospital. Graft dehiscence was managed with primary wound closure in all patients, except in some who required some combination of anterior vitrectomy, intraocular lens removal and reimplantation, and corneal regrafting. RESULTS: The incidence of traumatic wound dehiscence among patients on whom we performed PK over a period of 9 years was 2.53%. This complication occurred, on average, 3.4 years (2 months to 13 years) after PK. Most patients (76%) were men, and the average age at dehiscence was 59 years (range, 15-82 years). All corneal ruptures occurred at the graft-host junction, which had neither particular site preference nor quadrant specificity. Of the 16 eyes that were pseudophakic, nine (56.3%) had either loss of implants or dislocation of intraocular lens so severe that lens removal was imperative. In the end, only five (23.8%) of the 21 grafts retained clarity. Of the remaining 16 eyes, seven were regrafted, of which five (71.4%) grafts remained clear. Of the nine grafts that became opaque, six eyes (28.6%) atrophied. At the last follow-up, only six eyes (28.6%) had visual acuity of 20/200 or better, and six eyes had no perception of light. Final visual acuity was found to correlate inversely with the severity and extent of wound separation. CONCLUSION: Traumatic wound dehiscence is not rare after PK. The elderly corneal transplant patient may be more prone to such an injury. Corneal rupture at the graft-host junction in all of our cases means the persistence of wound weakness after PK. Although graft survival and visual outcome are generally poor after the injury, the restoration of a satisfactory visual result is possible after regrafting, insofar as the involved eye is free of intractable glaucoma or posterior segment damage.
Adolescent↗
Na,K-ATPase in lens epithelia from patients with senile cataracts.
Sodium-potassium-adenosine triphosphatase (Na,K-ATPase) has long been recognized for its role in regulating electrolyte concentrations in the lens, within which the electrolyte balance is vital to lens transparency. In this study, we compared the abundance of the alpha-subunit of Na,K-ATPase in lens epithelia of patients with senile cataracts, in order to examine the role of this enzyme in various types of lens opacity. Human lens epithelia were collected from 27 patients with senile cataracts who had undergone phacoemulsification. The type and the severity of lens opacity were graded and scored according to the Lens Opacities Classification System II. The mean age of the patients was 67.5 years (range, 46-80 yr). Abundance of the Na,K-ATPase alpha-subunit peptide in the lens epithelium was quantified by means of Western immunoblotting. Immunoblotting revealed that the amount of Na,K-ATPase alpha-subunit tended to decrease with increased cataract severity. In hypermature cataracts, the Na,K-ATPase alpha-subunit was barely detectable. The amount of alpha-subunit of Na,K-ATPase was inversely correlated with the overall severity of cataract (r = -0.64, p = 0.002). However, the inverse correlation was significant only in the cortical region (p = 0.027). As the cortex is located adjacent to the lens epithelium, it is directly affected by the loss of function of Na,K-ATPase in the epithelium. Such loss could result in water accumulation, vesicles, water clefts, Morgagnian globule formation, and Morgagnian cataract.
Aged↗
Substantia nigra lesion suppresses the antagonistic effects of N-methyl-D-aspartate receptor antagonist (MK-801) on the autotomy in the rat.
Rats received right dorsal root ganglionectomy (DRGn) to induce autotomy, and were treated with MK-801 and/or left substantia nigra (SN) lesion after DRGn. The behavior was quantified using an autotomy grading scale. All the rats in the control groups manifested autotomy from 4 to 19 days after DRGn and attained the highest autotomy score. The group treated with MK-801 immediately after DRGn showed suppression of the development of autotomy. The groups receiving left SN lesion with 6-hydroxydopamine immediately, 2, or 4 days after DRGn showed similar patterns of autotomy as the control groups. However, when combined with the administration of MK-801 immediately after DRGn, SN lesion done immediately or 2 days after DRGn suppressed the antagonistic effect of MK-801 (P < 0.01). When the SN lesion was delayed by 4 days, the suppression effect disappeared. These data suggest that the action of the NMDA receptor antagonist on the autotomy within 4 days after DRGn depend on the integrity of the dopaminergic system.
Animals↗
Suppression of autotomy by N-methyl-D-aspartate receptor antagonist (MK-801) in the rat.
The effects of different doses and time of administration of the N-methyl-D-aspartate (NMDA) receptor antagonist (MK-801) on the development of the autotomy (self-mutilation) were studied in the rats receiving dorsal root ganglionectomy (DRGn). The rats without any treatment and those treated with normal saline immediately after DRGn were the control groups. Three groups of rats were treated with 0.1, 0.5 or 1.0 mg/kg of MK-801 immediately after DRGn, and another three were treated with 1.0 mg/kg of MK-801 2, 4, or 7 days after DRGn. The behavioral observations of these rats were quantified using an autotomy grading scale ranging from 0 to 19, and the scores were compared among these groups. The rats in the control groups manifested autotomy from 5 to 17 days after DRGn and all of them (100%) attained the highest autotomy score. Lower doses (0.1 or 0.5 mg/kg) of MK-801 had no effect on the development of the autotomy. In contrast, higher dose (1.0 mg/kg) of MK-801 administered immediately after DRGn significantly suppressed the autotomy as compared to the control groups (P < 0.01) and only 17% of the rats in this group attained the highest score. The antagonistic effect was retained when the treatment of MK-801 was delayed to 2 days after DRGn, however, it disappeared when the treatment was delayed to 4 or 7 days after DRGn. Thus, the antagonistic effect of MK-801 on the autotomy induced by DRGn was dose-related and time-dependent. The main role of the NMDA receptor in the development of the autotomy was within several days after DRGn.
Afferent Pathways↗