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H K Li

Publications and source records attributed to H K Li.

At least 19 recordsLinked to original sources
PubMed2001

[Study of the charge transfer reaction between clotrimazolum and alizarin red].

The charge transfer reaction between clotrimazolum and alizarin red was studied spectrophotometrically. The reaction was achieved with good results in water-acetone solution. The apparent molar absorptivity is 8.7 x 10(3) L.mol-1.cm-1 at 525 nm. The Beer's law was obeyed in the range of 0-100 micrograms.mL-1 of clotrimazolum. The composition of the complex is 1:1. The proposed method has been applied successfully to the determination of clotrimazolum tablets.

Anthraquinones↗
PubMed2000

Sub-Tenon's injection for local anesthesia in posterior segment surgery.

OBJECTIVE: To determine whether the sub-Tenon's parabulbar approach for local anesthesia is a safe and effective choice for posterior segment surgery. DESIGN: Prospective, noncomparative case series. PARTICIPANTS: Two hundred seventy-six consecutive patients underwent posterior segment surgery at the University of Texas Medical Branch. INTERVENTION: Two hundred patients received sub-Tenon's parabulbar anesthesia containing an 11 -ml mixture of 5-ml 2% lidocaine (Xylocaine), 5-ml 0.5% bupivacaine (Marcaine), and 1 ml of 150 hyaluronidase (Wydase) units as primary anesthesia. The method did not involve a separate transcutaneous lid nerve or subconjunctival injection. MAIN OUTCOME MEASURES: The proportion of cases receiving supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both) was estimated. Its relationship to duration of surgery and surgical procedures deemed painful was assessed. Surgery lasting 3 hours or more was considered a long duration. Both scleral buckle and cryotherapy were considered painful procedures. The proportion of cases receiving additional local anesthesia preoperatively was also evaluated. Complications associated with sub-Tenon's parabulbar injection were monitored. RESULTS: There were 101 instances of patients receiving additional anesthesia. Nineteen received additional preoperative sub-Tenon's anesthesia, 12 received intraoperative local anesthesia supplementation, and 70 received intravenous medication. Of these 70, 19 required what the authors defined as a significant amount of intravenous medication, three of whom also received intraoperative local anesthesia supplementation. Consequently, 28 of 200 patients (14%; 95% confidence interval: 9.5, 19.6) received supplementation (significant intravenous anesthesia, intraoperative local anesthesia, or both). The proportion of cases receiving supplementation was directly related to duration of surgery. Patients involved in longer cases (51.7% vs. 7.6%; P < 0.001) and those involved in more painful procedures (48.2% vs. 8.7%; P < 0.001) were more likely to receive supplementation. Adjusting for surgery duration, a greater proportion of patients undergoing painful procedures required supplementation (31.3% vs. 0.5% for surgery < 3 hours, P = 0.003; 72.7% vs. 38.9% for surgery > or = 3 hours, P = 0.13). No associated ocular or systemic complications were observed. CONCLUSIONS: The results of this large study demonstrate that a single injection of sub-Tenon's anesthesia is relatively safe and effective for achieving local anesthesia during vitrectomies, with or without other intraocular procedures, lasting less than 3 hours. Other types of posterior segment surgery may require supplementation if they are more painful procedures, such as scleral buckle or cryotherapy, or last longer than 3 hours.

Adult↗
PubMed1999

Telemedicine screening of glaucoma.

OBJECTIVES: Glaucoma is a major cause of blindness. More than 80,000 Americans suffer permanent vision loss from the disease. Widespread screening is fundamental in limiting the incidence of glaucoma-associated blindness. This pilot study explored the use of stereo digital images taken at a primary care center for telemedicine review by an off-site specialist as a means of screening for glaucoma. MATERIALS AND METHODS: Thirty-two diabetic patients were screened at a family medicine clinic. None had previously been diagnosed with glaucoma. A senior optometry student took stereoscopic digital and 35-mm optic disc photographs with a nonmydriatic retinal camera. The digital images were forwarded to a remote ophthalmologist for review. The conventional color stereo slide pairs of the same eyes were subsequently reviewed for comparison. Agreement on signs of glaucomatous disc changes between the two imaging systems was analyzed. RESULTS: Twenty-six of 32 eyes' digital and 35-mm photographs were analyzed. Six of 32 eyes (18.8%) could not be compared due to lack of matching 35-mm slides or digital images. Out of 26 eyes, lamina cribosa visibility was undeterminable in 8 eyes' digital images and 3 other eyes' 35-mm slides. Agreement among digital images and 35-mm slides of the remaining eyes was: 100%-vertical elongation, barring of vessels, bayoneting of vessels, and drance hemorrhage; 96.2%-focus notching of rim and rim pallor; 93.3%-lamina cribosa visability; 92. 3%-overpass cupping; 88.5%-focal enlargement; 84.6%-parapapillary halo; 80%-nerve fiber visibility; 65.4%-parapapillary atrophy. Parapapillary halo (p = 0.046) and nerve fiber layer visibility (p = 0.18) were detected on some 35-mm slides but not seen on matching digital views. CONCLUSION: Evaluations of cup-to-disc ratio (C/D) using both methods were in general agreement. However, some digital images were noted as too dark for assessing fine glaucomatous disc changes. Stereo digital images taken with a nonmydriatic camera by nonophthalmic photographers is a promising alternative for glaucoma screening in primary care settings. Telemedicine offers efficient communications with off-site glaucoma specialists. A larger study population is necessary to determine the overall effectiveness of using stereo digital imagery and teleophthalmology for glaucoma screening.

Adult↗
PubMed1997

Transscleral ciliary sulcus fixation of a posterior chamber lens in an eye with congenital aniridia.

A 30-year-old man with bilateral congenital aniridia presented with a subluxated cataract in the right eye. He wore a soft contact lens for aphakic correction in the fellow eye after lensectomy for a subluxated cataract. We performed pars plana lensectomy and vitrectomy with implantation of a transscleral ciliary sulcus fixated posterior chamber intraocular lens in the right eye. Good postoperative visual acuity was obtained.

Adult↗
PubMed1996

Reversal of visual loss with hyperbaric oxygen treatment in a patient with Susac syndrome.

PURPOSE: The purpose of the study is to report on a 34-year-old woman with Susac syndrome who presented on two separate occasions with visual acuity loss from a recurrent branch retinal artery occlusion and underwent hyperbaric oxygen treatment with favorable outcome. METHODS: Visual acuity was 20/400 in the left eye and count fingers in the right eye after separate occlusive events. The patient underwent hyperbaric oxygen treatment on each occasion of visual acuity loss. The patient subsequently was diagnosed with Susac syndrome (microangiopathy of the retina, brain, and middle ear). The authors present visual fields, photographs, angiograms, and ancillary tests documenting diagnosis and course of treatment. RESULTS: On each occasion, visual acuity improved to 20/25 during and was maintained after hyperbaric oxygen treatment. Visual fields showed improvement immediately after treatment. CONCLUSION: This is the first report of hyperbaric oxygen treatment for Susac syndrome. Dramatic post-treatment visual field and acuity changes suggest benefit of treatment. Hyperbaric oxygen treatment can be considered a treatment option for visual complications of this syndrome. Susac syndrome should be included in the differential diagnosis of recurrent branch retinal artery occlusion.

Adult↗
PubMed1996

Congenital cystic eye.

We present a rare case of congenital cystic eye associated with holoprosencephaly and tetralogy of Fallot. The orbital cyst was diagnosed preoperatively by computed tomography (CT) scan, and we present the first magnetic resonance imaging (MRI) finding in such a disorder. The orbital cyst expanded over 7 months of follow-up. The cyst was excised in toto and studied by immunohistochemistry, and its content was analyzed biochemically. The patient achieved an acceptable cosmetic result.

Cysts↗
PubMed1995

Cytomegalovirus optic neuritis: characteristics, therapy and survival.

Little is known about the natural history of cytomegalovirus (CMV) optic neuritis in the acquired immunodeficiency syndrome. We analyzed the clinical course of CMV optic neuritis in 30 consecutive subjects (35 eyes), and compared the survival of patients with CMV optic neuritis to that of a group having CMV retinitis alone, with both groups matched for ganciclovir therapy. Four untreated eyes had a median final visual acuity of no light perception. The median final visual acuity was 20/100 in treated subjects with a mean follow-up of 6.6 months. Following ganciclovir treatment, 2 eyes showed visual improvement, 17 eyes had unchanged visual acuity, and 12 eyes had marked drop in acuity. Relapse occurred in 4 subjects maintained on single-dose ganciclovir, and was controlled on double-dose ganciclovir. Survival was similar in the group of CMV retinitis alone versus the group of CMV optic neuritis with retinitis. Early recognition and therapy of CMV optic neuritis protects against irreversible visual loss. CMV optic neuritis does not carry a worse prognosis for survival than CMV retinitis alone.

AIDS-Related Opportunistic Infections↗
PubMed1993

Frosted retinal periphlebitis in the acquired immunodeficiency syndrome.

Six patients with the acquired immunodeficiency syndrome had frosted periphlebitis associated with large areas of cytomegalovirus retinitis. Following the administration of ganciclovir, periphlebitis resolved within 2-6 weeks concomitant with quieting of cytomegalovirus retinitis. Frosted retinal periphlebitis in the acquired immunodeficiency syndrome is associated with cytomegalovirus retinitis in North America. Medical treatment of cytomegalovirus retinitis leads to resolution of the periphlebitis without the need for systemic corticosteroids.

AIDS-Related Opportunistic Infections↗
PubMed1989

[Changes in the relaxation and compliance of the left ventricle in cardiomyopathy].

In order to study the left ventricular diastolic events in cardiomyopathy, carotid pulse tracing, electrocardiogram, phonocardiogram and apexcardiogram with its first derivatives (dA/dt) were simultaneously recorded in 240 normal subjects, 30 patients with dilated cardiomyopathy (DCM) and 44 patients with hypertrophic cardiomyopathy (HCM). Total relaxation time (TRT), total relaxation time index (TRTI), the ratio of A wave to total diastolic amplitude in apexcardiogram (A/D), diastolic amplitude time index (DATI), the ratio of RF wave in apexcardiogram to the total amplitude of apex tracing (F/H) and the variables reflecting the diastolic properties were measured to evaluate the left ventricular relaxation and compliance. Meanwhile, two variables reflecting the contractile ability of the left ventricle were measured in order to compare with the diastolic events. The results demonstrated that in normal subjects relaxation and compliance of the left ventricle showed a tendency of natural "decay" with aging and in patients with DCM and HCM these were significantly decreased, especially in patients with HCM. A/D, which reflects the left ventricular compliance, was increased in patients with HCM as compared with normal subjects (P less than 0.01) and also with patients with DCM. It means that a greater A/D is in favor of the diagnosis of HCM rather than DCM. In addition to abnormal diastolic events, systolic dysfunction, as evidenced by remarkable abnormalities of the contractile variables (PEP/LVET and R-dA/dt.I), was found as well in patients with DCM.

Adolescent↗
PubMed1986

Elemental content of anagen hairs in a normal Caucasian population studies with proton induced X-ray emission (PIXE).

The elemental content of anagen hair fibers in a Caucasian population of healthy females and males in the age range 10-69 years was performed to constitute a baseline for further studies of pathological conditions. Proton induced X-ray emission (PIXE) analyses were performed on single hair fibers in triplicate from 103 individuals in order to determine sulfur, zinc, calcium, and chlorine content. The hair fibers were all anagen hairs collected from a site little influenced by genetic and hormonal influences 1.5 cm above the right ear of the probands. An area 5-8 mm from the follicle bottom was chosen for the analysis in all cases to minimize effect of hair-do contamination. The average sulfur content was 0.049 g/g and the average zinc content 170 micrograms/g. These results were not significantly influenced by chloroform/ethanol rinsing before analysis. The calcium and chlorine contents were 330 micrograms/g and 0.0033 g/g respectively. The latter data are expected to be more seriously influenced by external factors (e.g., contamination) than sulfur and zinc. No correlation between elemental concentration and sex was found for sulfur and zinc in the present material. PIXE analysis of single hair fibers yields valuable information on the elemental composition of hair fibers and can be rapidly and efficiently performed after simple mounting procedures.

Adolescent↗
PubMedDate not supplied

Telemedicine and ophthalmology.

Technology to create and move multimedia medical information is creating alternatives to physically transporting patients and health care professionals. Teletechnology is a physician extender, both supplementing and reinventing traditional health care delivery systems. The potential of comprehensive teleophthalmology is compelling. This article provides a historical perspective of telemedicine, describes various teleophthalmology systems, and surveys teleophthalmology in clinical consultation, research, and education programs around the world. It also discusses basic issues in applying teleophthalmology to public health.

History, 20th Century↗