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Biomedical subjects

Y J Hong

Publications and source records attributed to Y J Hong.

At least 37 records · Page 2Linked to original sources
PubMed1998

The changes in main pulmonary artery pressure after bilateral lung autotransplantation in dogs.

In the Respiratory Center, Yongdong Severance Hospital, Yonsei University, we performed 10 cases of bilateral lung autotransplantation in mongrel dogs from July 1994 to June 1996, and we have analyzed the hemodynamic changes. Autotransplantation was performed in order to avoid postoperative rejection. The lung was flushed with an Euro-Collins(E-C) solution containing PGE1 which passed through a 10 French catheter inserted into an incision on the anterior half of the pulmonary artery to pulmonary parenchyme, and the vertical incision was made on the anterior half of the left atrium near the proximal part of the pulmonary vein. However, the bronchus was totally divided after clamping both sides. The lung was kept cold (4 degrees C) in the thoracic cavity for an hour by using slushed ice made from an E-C solution. After an hour of cold ischemia, the pulmonary artery was sutured with Prolene 5-0. The pulmonary vein was sutured with Prolene 6-0 by using the continuous everting mattress method. The main bronchus was anastomosed using the telescope method. The arterial oxygen concentration and the pressures in the femoral and pulmonary arteries were measured both preoperatively and postoperatively. There were no significant hemodynamic differences between the preoperative and postoperative mean pulmonary artery pressure (MPAP) (paired t-test, P = 0.05). Lung preservation using a cold (4 degrees C) E-C solution containing PGE1 may be an acceptable method for short-term storage of a lung (for about an hour) in bilateral lung autotransplantation in dogs.

Animals↗
PubMed1998

The effect of mitomycin-C on postoperative corneal astigmatism in trabeculectomy and a triple procedure.

BACKGROUND AND OBJECTIVE: The authors attempted to determine the effect of mitomycin-C (MMC) on postoperative corneal astigmatism in patients who underwent trabeculectomy or a triple procedure (trabeculectomy, extracapsular cataract extraction, and intraocular lens implantation). PATIENTS AND METHODS: Using the vector analysis method, the authors measured the postoperative induced astigmatism of 76 eyes in 59 patients who underwent trabeculectomy or a triple procedure with or without the application of MMC. Postoperative induced astigmatism corresponding to the 180 degrees axis was compared between the two groups. RESULTS: The patients who underwent trabeculectomy with or without MMC showed a mean induced astigmatism of -1.01 D and -2.63 D, respectively, after 1 month (P < .05), and 0.34 D and -1.42 D after 12 months (P < .05). Those who underwent a triple procedure with or without MMC showed a mean induced astigmatism of -1.81 D and -4.50 D, respectively, after 7 days (P < .05), and 1.73 D and -0.13 D, respectively, after 12 months (P < .05). The entire amount of postoperative against-the-rule astigmatic shift was similar between the with-MMC group and the without-MMC group. The against-the-rule astigmatic shift of the group without MMC reached a plateau after 3 months. However, the group with MMC showed continuous against-the-rule astigmatic shift until 12 months. CONCLUSION: This study suggests that MMC induces less with-the-rule astigmatism in early postoperative periods and continuous against-the-rule shift after 3 months following a trabeculectomy or a triple procedure.

Administration, Topical↗
PubMed1997

Laser trabeculoplasty: how little is enough?

BACKGROUND AND OBJECTIVE: The optimal number of laser applications for argon laser trabeculoplasty in patients with primary open-angle glaucoma has not been established. The purpose of this study was to determine the fewest number of burns necessary for clinically effective intraocular pressure reduction for these patients. PATIENTS AND METHODS: Using a prospective, randomized, collaborative study, the authors examined the relationship between the number of laser trabeculoplasty burns and intraocular pressure for patients with primary open-angle glaucoma. A total of 122 patients received either 50 burns to half of the trabecular meshwork (group 1) or 35 burns to one third of the trabecular meshwork (group 2). RESULTS: The mean baseline intraocular pressures were similar between group 1 (22.3 +/- 4.1 mm Hg [mean +/- SD]) and group 2 (22.8 +/- 5.0 mm Hg) (P = .58). Intraocular pressure reduction at 9 to 12 months, although significant in both groups (group 1: 4.4 +/- 3.0 mm Hg, P < .0001; group 2: 3.9 +/- 5.1 mm Hg, P < .0001), did not differ significantly between the two groups (P = .63). CONCLUSION: This study demonstrated that 35 burns may be as clinically effective as 50 burns in reducing the intraocular pressure in primary open-angle glaucoma patients.

Aged↗
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↗
PubMed1995

Intraocular pressure after a two-week washout following long-term timolol or levobunolol.

The effect on intraocular pressure (IOP) of a 2-week washout following long-term ocular therapy with topical levobunolol or timolol for an average period of 30 months was investigated in 20 patients (11 whites and 9 blacks) with early primary open-angle glaucoma or ocular hypertensive glaucoma suspect status. The 2-week washout IOP was significantly lower than the pretreatment baseline IOP in the total 20 patients (P < 0.001), and in the 9 black patients (P = 0.004), but not in the 11 white patients (P = 0.065). However, the washout IOP was found to be significantly lower than the baseline IOP in the 5 whites with brown irides (P = 0.024) but not in the 6 whites with blue irides (P = 0.574). Thus, the 2-week washout following long-term ocular therapy with a topical beta 1-, beta 2-blocker appears insufficient to restore IOP to the pretreatment baseline level in blacks and in the whites with brown irides, whereas it may be adequate in the majority of the whites with blue irides.

Administration, Topical↗
PubMed1995

Modification of the scleral openings to reduce tissue breakdown and exposure after hydroxyapatite implantations.

We compared the incidence of exposure of the hydroxyapatite implant after evisceration according to the position of scleral windows which allow rapid fibrovascularization into the implant. Three patients (10%) developed tissue breakdown and exposure of the hydroxyapatite, out of 30 patients who had external scleral windows located in a position just anterior to the insertion of each of the rectus muscles, whereas no patient developed exposure, out of 24 patients who had internal scleral windows located in a position just position just posterior to the insertion of each of the rectus muscles. Internal windows sealed with rectus muscles could prevent direct contact between implant and the overlying Tenon's capsule and conjunctiva. These findings seem to indicate that the rough spicular surface of the hydroxyapatite irritates and erodes the overlying Tenon's capsule and conjunctiva.

Biocompatible Materials↗
PubMed1994

The relationship between cognition and action: performance of children 3 1/2-7 years old on a Stroop-like day-night test.

One hundred and sixty children 3 1/2-7 years of age (10 M, 10 F at each 6-month interval) were tested on a task that requires inhibitory control of action plus learning and remembering two rules. They were asked to say "day" whenever a black card with the moon and stars appeared and to say "night" when shown a white card with a bright sun. Children < 5 years had great difficulty. They started out performing well, but could not sustain this over the course of the 16-trial session. Response latency decreased from 3 1/2 to 4 1/2 years. Children < 4 1/2 years performed well when they took very long to respond. To test whether the requirement to learn and remember two rules alone was sufficient to cause children difficulty, 80 children 3 1/2-5 years old were tested on a control version of the task ("say 'day' to one abstract design and 'night' to another"). Even the youngest children performed at a high level. We conclude that the requirement to learn and remember two rules is not in itself sufficient to account for the poor performance of the younger children in the experimental condition.

Age Factors↗
PubMed1994

Excess cancer mortality among children and adolescents in residential districts polluted by petrochemical manufacturing plants in Taiwan.

We have collected data on the cancer deaths of children and adolescents 0-19 yr old living in a residential area near 3 large petroleum and petrochemical complexes in and near Kaohsiung city (petrochemical industrial districts, PIDs) in the period of 1971-1990 and compared these with the cancer deaths of children and adolescents 0-19 yr old among the entire population of Taiwan (national reference) and among the residents of 26 administrative districts, comprising all of Kaohsiung city and Kaohsiung county (local reference), except for 8 sparsely populated, rural districts. Having scrutinized all cancer death certificates, we have identified various statistically significant excess deaths, as compared with the national and local reference, due to cancers at all sites. Cancer of the bone, brain, and bladder in boys and girls 0-9 yr and 10-19 yr of age in the 1981-1990 decade that followed the establishment of petrochemical production in the PIDs was studied. However, excess cancer deaths seemed to have clustered in the 10-19 yr age group, who had been potentially exposed to the petrochemical pollutants for the longest period of time from the youngest age. Almost all bone, brain, and bladder cancer deaths registered were within 3 km of the 3 complexes. Bone and brain cancers in particular occurred in girls in the PIDs more frequently than in boys, even though these are believed to occur more in males than females elsewhere.

Adolescent↗
PubMed1993

[Intrathecal meperidine attenuates shivering induced by spinal anesthesia].

Shivering is a common and complex phenomenon that occurs in many patients during spinal anesthesia. Shivering can increase oxygen consumption up to 500 per cent which may be detrimental to patients with decreased myocardial reserve. The metabolic costs and cardiorespiratory consequences of shivering are important particularly for patients with anemia, coronary arterial disease, cardiopulmonary insufficient, debilitated status or are elderly. We studied whether intrathecal meperidine could prevent shivering after spinal anesthesia. 60 patients with ASA class I-II were divided into intrathecal meperidine group (Group I) (n = 30) and control group (Group II) (n = 30). Group I received spinal tetracaine 12-16 mg with meperidine 0.2 mg/kg and Group II received spinal tetracaine 12-16 mg without meperidine. During operation the highest level of spinal anesthesia, ambient and rectal temperatures, blood pressure (BP) and heart rate (HR), presence or absence of shivering, intensity of shivering in both groups were recorded. Close observation for side effects was given post-operatively. There was a significant reduction (p < .005) in incidence of shivering in group I patients (16.7%) when compared with group II (56.7%). There was no or less side effects observed with other neuraxial opioids except nausea. We concluded that intrathecal meperidine could suppress shivering induced by spinal anesthesia.

Adult↗
PubMed1993

[Nifedipine in preeclampsia for cesarean section].

The patients with preeclampsia undergoing emergent cesarean section is always a challenge to an anesthesiologist, because severe hypertensive response after laryngoscopy and tracheal intubation may result in life-threatening complication such as cerebral hemorrhage. Most of these patients receive magnesium sulfate for the prevention of convulsion. An ideal anti-hypertensive drug for preeclampsia should be effective, limited fall in blood pressure, rapid onset, maintaining uteroplacental blood flow, and less maternal and fetal side effects. We studied the efficacy of 10 mg sublingual nifedipine in attenuating the pressor response to intubation. We were also concerned about whether this calcium antagonist may inhibit uterine contraction and increase intra and postpartum hemorrhage when it is used with magnesium sulfate and general anesthesia. There were thirty-three patients in our study (16 in nifedipine group and 17 in control group). This study revealed that nifedipine attenuate the hypertensive response effectively. Uterine contraction response to oxytocic drugs was quite well in both groups. There was no significant difference in blood loss between nifedipine and control group. And no severe maternal and fetal adverse effect.

Adult↗
PubMed1992

Takayasu arteritis in Korean children: clinical report of seventy cases.

Seventy cases of Takayasu arteritis in Korean children are reported. There were 57 females and 13 males (male-to-female ratio; 1:4.4). The youngest patient was a 3-year-old female. Family history was positive in one patient. The most common chief complaints on admission were dyspnea, headache, palpitation, and edema which were due to hypertension and congestive heart failure. Hypertension was seen in 65 out of 70 patients (92.8%). The abdominal aorta, thoracic aorta, and renal arteries were the most commonly involved sites in these children. Two patients had nephrotic syndrome. The frequency of positive tuberculin reaction was much higher in children with Takayasu arteritis compared with the general population, and the intensity of the reaction was also stronger. The majority of the patients required immediate medical treatment to control congestive heart failure due to hypertension at initial presentation. When ESR was elevated, corticosteroid was administered. Surgical treatment showed good results in six out of ten cases. Percutaneous intraluminal angioplasty was effective for lowering the blood pressure in six out of nine cases. In three cases, restenosis occurred and angioplasty was repeated in two cases.

Adolescent↗
PubMed1992

Intraocular pressure-dependent dynamic changes of optic disc cupping in adult glaucoma patients.

The authors performed a study of intraocular pressure-dependent changes in optic disc cupping in 17 adults with chronic open-angle glaucoma. Analyses with the Rodenstock Optic Nerve Head Analyzer were performed at baseline low intraocular pressure during therapy, after elevation of intraocular pressure (from therapeutic failure or noncompliance), and after reduction of intraocular pressure with successful therapy. Optic disc cupping increased significantly upon short-term increase of intraocular pressure from baseline of 20.4 +/- 2.5 mmHg to 31.1 +/- 5.9 mmHg. Optic disc cupping reverted to baseline after persistent intraocular pressure reduction to 19.3 +/- 4.8 mmHg. These data demonstrate intraocular pressure-dependent dynamic changes of optic disc cupping in patients with demonstrable glaucomatous optic nerve damage. They underscore the detrimental effect of elevated intraocular pressure and the beneficial effect of intraocular pressure reduction on optic disc cup changes.

Adult↗
PubMed1990

Computerized optic disc analysis with adjunct stereoscopic viewing of disc photographs.

We have investigated the potential usefulness of stereoscopic viewing of optic disc photographs in marking the disc margin in computerized analysis with the Rodenstock Analyzer in 48 eyes of 26 patients with ocular hypertension or primary open-angle glaucoma. Marking of the disc margin without Method 1) and with the aid of stereoscopic viewing of disc photographs (Method 2) three consecutive times by one observer at the same sitting, and three subsequent topographic analyses of each method were done on each 48 eyes. The mean intraphotographic variabilities of such optic disc parameters as rim area, and cup volume with Method 2 were significantly less than those with Method 1 overall and in 16 eyes (33%) with poor video images having an ill-defined disc margin (p less than 0.05 for each), but not in 32 eyes (67%) with clear video images having a well-defined disc margin. Furthermore, the mean paired differences of rim area, disc area and cup volume between the two methods (Method 1 minus Method 2) were also statistically significant overall and in eyes with poor video images (p less than 0.05 for each).

Adult↗
PubMed1989

Reversal of glaucomatous optic disc cupping in adult patients.

A prospective study of reversal of glaucomatous optic disc cupping was performed by topographic optic disc analysis using the optic nerve head analyzer (Rodenstock analyzer, G. Rodenstock Instrumente GMBH, Munich, West Germany) in 13 adults with chronic open angle glaucoma. Intraocular pressure decreased from the mean (+/- SD) initial intraocular pressure of 33.2 +/- 8.2 mm Hg to the final intraocular pressure of 16.9 +/- 6.1 mm Hg over 13.6 +/- 10.4 weeks. Mean (+/- SD) cup-disc ratio decreased significantly, from 0.573 +/- 0.207 to 0.499 +/- 0.198, and mean (+/- SD) neuroretinal rim area increased significantly, from 0.913 +/- 0.341 to 1.042 +/- 0.284 mm2. The decrease of mean (+/- SD) cup volume from 0.592 +/- 0.966 to 0.451 +/- 0.703 mm3 was only marginally significant. However, more meaningful was a finding that reversal of cup volume, like reversals of cup-disc ratio and rim area, was directly proportional to the percent IOP reduction (r = .669 for cup volume reversal; r = .626 for cup-disc ratio reversal; and r = .675 for rim area reversal).

Adult↗
PubMed1989

Is it worthwhile to add dipivefrin HCl 0.1% to topical beta 1-, beta 2-blocker therapy?

In a prospective study, the addition of dipivefrin hydrochloride 0.1% twice daily to one eye of 32 patients with early primary open-angle glaucoma or ocular hypertension, maintained on a bilateral beta 1-, beta 2-blocker twice daily, resulted in a significant decrease of mean intraocular pressure (IOP) from 22.7 +/- 3.9 to 20.2 +/- 3.4 mmHg at 1 week (P = 0.0001) and to 21.0 +/- 3.8 mmHg at 12 weeks (P less than 0.02) in the dipivefrin-treated eyes. On the other hand, no significant change was noted in the fellow eyes (from 21.7 +/- 4.1 to 21.6 +/- 4.0 mmHg at 1 week and to 21.3 +/- 4.2 mmHg at 12 weeks). The addition of dipivefrin resulted in an IOP reduction of 2 mmHg or more in 50% and 3 mmHg or more in 19% of the eyes throughout the 12-week therapy. The result of the current study provides a realistic guideline as to what to expect from the common practice of adding dipivefrin hydrochloride to a beta 1-, beta 2-blocker regimen.

Administration, Topical↗
PubMed1988

Implantation of posterior chamber lens in the absence of capsular and zonular support.

We have developed surgical techniques for implanting a posterior chamber lens in the absence of capsular and zonular support by securing both haptics of the posterior chamber lens to the sclera at the ciliary sulcus with 10-0 prolene suture. These techniques have been successfully performed and have produced good visual results in six monocularly aphakic patients who had contact lens intolerance and/or contraindications to anterior chamber lens implantations. In consideration of the high incidence and the great variety of complications associated with anterior chamber lenses, these newly developed surgical techniques will be a useful alternative to anterior chamber lenses, even in patients who do not have definite contraindications to anterior chamber lens implantations.

Humans↗