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Biomedical subjects

J H Liu

Publications and source records attributed to J H Liu.

At least 127 records · Page 7Linked to original sources

Mibefradil (Ro 40-5967) inhibits several Ca2+ and K+ currents in human fusion-competent myoblasts.

1. The effect of mibefradil (Ro 40-5967), an inhibitor of T-type Ca2+ current (I(Ca)(T)), on myoblast fusion and on several voltage-gated currents expressed by fusion-competent myoblasts was examined. 2. At a concentration of 5 microM, mibefradil decreases myoblast fusion by 57%. At this concentration, the peak amplitudes of I(Ca)(T) and L-type Ca2+ current (I(Ca)(L)) measured in fusion-competent myoblasts are reduced by 95 and 80%, respectively. The IC50 of mibefradil for I(Ca)(T) and I(Ca)(L) are 0.7 and 2 microM, respectively. 3. At low concentrations, mibefradil increased the amplitude of I(Ca)(L) with respect to control. 4. Mibefradil blocked three voltage-gated K+ currents expressed by human fusion-competent myoblasts: a delayed rectifier K+ current, an ether-à-go-go K+ current, and an inward rectifier K+ current, with a respective IC50 of 0.3, 0.7 and 5.6 microM. 5. It is concluded that mibefradil can interfere with myoblast fusion, a mechanism fundamental to muscle growth and repair, and that the interpretation of the effect of mibefradil in a given system should take into account the action of this drug on ionic currents other than Ca2+ currents.

Adolescent↗

Observation of the correlation of postanaesthesia recovery scores with early postoperative hypoxaemia in children.

To observe the correlation of the postanaesthesia recovery score (PARS) with the incidence, and severity of early postoperative hypoxaemia in children, 1213 infants and children, ASA physical status I, aged three months to 14 years, scheduled for elective plastic surgery were included in this study. Arterial oxygen saturation (Spo2) levels were recorded while children were breathing room air shortly after arrival in the recovery room (0 min), and 5, 10, 15, 20, 30, 40, 50, 60, 120 and 180 min thereafter. The PARS was also determined on all patients when Spo2 levels were recorded in the recovery room. On the basis of different PARS, children were divided into the three groups: Group 1-children having the PARS of < or = 6; Group 2-children having the PARS of 7-9; and Group 3-children having a PARS of 10. The results showed that during the early postoperative period, the incidence and severity of hypoxaemia correlated closely with the PARS. The lower the children's PARS, the higher the incidences of hypoxaemia (Spo2 = 86-90%) and severe hypoxaemia (Spo2 < or = 85%). The incidences of hypoxaemia and severe hypoxaemia were 12.9% and 15.8%, respectively, in Group 1, 20.9% and 2.9% in Group 2, 0.8% and 0% in Group 3. There were significant differences among the three groups. Of the 91 children who required O2 supplementation in the recovery room because of low measured Spo2, 69 had the PARS of < or = 6, and 22 had the PARS of 7-8. It is concluded that if a patient has a PARS of 10, the patient will not need routine oxygen supplement because hypoxaemia will not occur.

Adolescent↗

ESHAP as salvage therapy for refractory non-Hodgkin's lymphoma: Taiwan experience.

BACKGROUND: The ESHAP regimen, a combination of the chemotherapeutic drugs etoposide, methylprednisolone (solumedrol), high-dose cytarabine (ara-C) and cisplatin, has been shown to be active against refractory non-Hodgkin's lymphoma in therapeutic trials. We were interested in determining whether this regimen would be effective and tolerable for Chinese patients. METHODS: Thirty-two patients with refractory/relapsed non-Hodgkins lymphoma (23 intermediate-grade and nine high-grade) were enrolled in this study. Etoposide was administered at a dose of 40 mg/m2/day as a 1 h intravenous infusion from day 1 to day 4, solumedrol 500 mg/day was given as a 15 min intravenous infusion from day 1 to day 5, ara-C 2 g/m2 was given as a 2 h intravenous infusion on day 5 and cisplatin was given at a dose of 25 mg/m2/day as a continuous infusion from day 1 to day 4. Clinical efficacy and toxicity were assessed on the basis of the WHO criteria. RESULTS: Ten patients (31.3%, 95% Cl 15.2-47.4%) attained complete remission (CR) and seven had partial remission (PR). The overall response rate was 53.1% (95% Cl 35.8-70.4%). In eight of the 10 CR patients, the remission lasted for more than 8 months. The remaining two patients had CR of 5 and 6 months. The median duration of CR was 12.2 months (range 5-22 months). Myelosuppression with subsequent infections was the major toxicity. Severe leukopenia (WBC < 1000/microliter) lasted for an average of 12 days and thrombocytopenia (< 25,000/microliter) 18 days. One patient (3.1%) died of neutropenia-associated sepsis within 4 weeks after treatment. Non-myeloid toxicities included alopecia in 66% (28% grade 2, 22% grade 3), stomatitis in 72% (25% grade 2, 28% grade 3, 13% grade 4), hepatotoxicity in 9% (3% grade 2), renal toxicity in 13% (6% grade 2, 3% grade 3) and infection in 56% (18% grade 2, 25% grade 3, 13% grade 4). The majority of the responders relapsed within 2 years after ESHAP treatment. Median survival for all patients was 8.6 months. CONCLUSIONS: ESHAP is an active and tolerable regimen in Chinese patients with relapsed/refractory lymphoma, but the duration of remission is brief and without significant impact on survival.

Adult↗

The influence of surgical sites on early postoperative hypoxemia in adults undergoing elective surgery.

UNLABELLED: To determine the influence of the surgical sites on early postoperative hypoxemia, we studied postoperative hypoxemia in 994 patients, ASA physical status I or II, aged 18-68 yr, scheduled for various types of elective surgery. Patients were divided into three groups on the basis of the surgical sites: Group 1 = elective superficial plastic surgery (n = 288); Group 2 = upper abdominal surgery (n = 452); and Group 3 = thoracoabdominal surgery (n = 254). Anesthesia was maintained with 1%-2% enflurane and 67% nitrous oxide in oxygen; thiopental or fentanyl was given IV as required. SpO2 levels were recorded while patients breathed room air shortly after arrival in the recovery room (0 min) and 5, 10, 15, 20, 30, 40, 50, 60, 120, and 180 min thereafter. The results showed that during the early postoperative period, the degree of arterial desaturation and the incidences of hypoxemia (SpO2 86%-90%) and severe hypoxemia (SpO2 85%) were closely related to the operative sites and were greatest for thoracoabdominal operations, less for the upper abdominal operation, and least for the peripheral surgery. The incidence of hypoxemia and severe hypoxemia in the recovery room was 7% and 0.7%, respectively, in Group 1, 38% and 3% in Group 2, and 52% and 20% in Group 3. Mild airway obstruction and hypothermia in the postanesthesia recovery unit (PAR) were the predictive factors of early postoperative hypoxemia. We conclude that during the early postoperative period, there were significant differences in SpO2 levels and incidences of hypoxemia and severe hypoxemia among the three groups. IMPLICATIONS: We found that the severity of arterial desaturation and the incidence of hypoxemia during the early postoperative period are closely related to the surgical sites and are strongest for thoracoabdominal surgery, less for upper abdominal surgery, and least for peripheral surgery.

Abdomen↗

Characterization of a Neocallimastix patriciarum xylanase gene and its product.

A xylanase gene (xynC) isolated from the anaerobic ruminal fungus Neocallimastix patriciarum was characterized. The gene consists of an N-terminal catalytic domain that exhibited homology to family 11 of glycosyl hydrolases, a C-terminal cellulose binding domain (CBD) and a putative dockerin domain in between. Each domain was linked by a short linker domain rich in proline and alanine. Deletion analysis demonstrated that the CBD was essential for optimal xylanase activity of the enzyme, while the putative dockerin domain may not be required for enzyme function.

Amino Acid Sequence↗

Pediatric type I thyroplasty: an evolving procedure.

The treatment of vocal fold paralysis by type I thyroplasty in the pediatric age group has not been reported. From 1990 to 1998, 12 type I thyroplasty procedures were performed on 8 patients between 2 and 17 years of age. The most common cause of vocal fold paralysis was neurologic, followed by vagal injury from a cardiac procedure. The most common indications for the procedure were aspiration and dysphonia. In our early thyroplasty experience, adult techniques and measurements adapted after Isshiki or Netterville were used. Postoperative laryngoscopy showed that in most cases, the placement of the implant was too high. There were variable outcomes in aspiration and dysphonia with this technique. These findings appear to be independent of thyroplasty approach or of implant design type. We conclude that the standard approach for vocal fold medialization in the adult cannot be applied accurately in the pediatric population. In performing pediatric thyroplasty, the anatomically lower position of the vocal fold must be taken into consideration. We have since modified our technique to adjust for accurate identification of the vocal fold line and medialization. The modified approach for vocal fold medialization in the pediatric population is discussed.

Adolescent↗

Prognostic significance of immunoglobulin and T cell receptor gene rearrangements in patients with acute myeloid leukemia: Taiwan experience.

We investigated the prognostic significance of lymphoid antigen receptor gene rearrangement in patients with newly diagnosed acute myeloid leukemia (AML). Thirty-nine patients were included in the study. Clonal gene rearrangement of immunoglobulin heavy chain (IgH) and T cell receptor beta chain (TCRbeta) was found in leukemic cells in 11 (28.2%) and 10 (25.6%) patients, respectively. Five (12.8%) had both IgH and TCRbeta gene rearrangements. Three of the seven (42.9%) B-lymphoid marker-positive and eight of the 32 (25%) B-lymphoid marker-negative patients had clonal IgH gene rearrangements. Five of the 11 (45.5%) T-lymphoid marker-positive and 5 of the 28 (17.9%) T-lymphoid marker-negative patients had clonal TCRbeta gene rearrangements. All patients were treated with similar regimens. The complete remission rate (62.5% vs 65.2%, p=1.000) and median survival (13 vs 14 months, p=0.366) were similar in patients with and without clonal IgH or TCRbeta gene rearrangements. In conclusion, while clonal rearrangements of IgH or TCRbeta genes were found in AML patients, they did not appear to effect the prognosis.

Acute Disease↗

Natural course of submacular hemorrhage.

BACKGROUND: Age-related macular degeneration (ARMD) is the most prevalent cause of blindness in the elderly population. This study retrospectively evaluated the natural course of submacular hemorrhage related to ARMD. METHODS: We reviewed the records of patients with submacular hemorrhage and foveal avascular zone involvement at the Veterans General Hospital-Taipei from 1981 to 1996. Data were collected from color fundus pictures, fluorescence angiographic films and visual acuity changes. RESULTS: Data from a total of 86 eyes with age-related macular degeneration (ARMD) and 37 non-ARMD eyes were collected. Analysis of data from the ARMD group revealed 10.5% visual acuity improvement six months after presentation and a final mean acuity of 0.069. Analysis of data from the non-ARMD group revealed 29.7% visual acuity improvement and a final mean acuity of 0.388. CONCLUSIONS: In this study, patients with submacular hemorrhage had spontaneous visual improvement even without surgery, especially those without subretinal neovascularization.

Aged↗

Progression of cytomegalovirus retinitis in acquired immunodeficiency syndrome: a case report.

We report an AIDS patient with cytomegalovirus (CMV) retinitis that developed from an early minor lesion and progressed to extended involvement of the retina and severe deterioration of vision due to poor compliance with ganciclovir treatment. A 33-year-old man was known to have acquired immunodeficiency syndrome (AIDS) for eight months. The patient had no complaint of visual symptoms. A routine eye examination revealed his visual acuity to be 6/6 in both eyes. The dilated eye fundus examination using indirect ophthalmoscopy disclosed a localized white yellowish granular lesion in the peripheral retina of the right eye and a completely normal left eye. CMV retinitis with initial manifestation in the right eye was diagnosed. Due to incomplete treatment with ganciclovir, the retinal lesion rapidly enlarged and extended to the posterior pole, with eventual destruction of the nerve fiber layer and optic disc. The visual acuity of right eye dropped from 6/6 to 1/60 within six months. This case report indicates the importance of early, dilated eye fundus examination and recognition of early CMV retinitis in order to salvage visual function in AIDS patients. Completion of the anti-CMV treatment course in halting the progression of CMV retinitis is also emphasized.

AIDS-Related Opportunistic Infections↗

Elevation of human intraocular pressure at night under moderate illumination.

PURPOSE: An endogenous elevation of intraocular pressure (IOP) occurs at night in healthy young adults. The authors studied whether or not this IOP elevation can be detected under moderate illumination. METHODS: Twenty-five healthy volunteers, ages 18 to 25 years, were housed overnight in a sleep laboratory under a strictly controlled light-dark environment. Intraocular pressure was measured in the supine position every 2 hours, using a pneumatonometer. An 8-hour sleep period was assigned to each volunteer according to individual's accustomed sleep cycle. In the early part of this assigned period, sleep was encouraged with room lights off. Researchers performed IOP measurements at two time points with the aid of night vision goggles. In the middle to the late part of the assigned period, lights were turned on twice for a 1-hour interval. The light intensity was the same as before the bedtime. At the ending of each light period, IOP was measured under illumination. RESULTS: Average IOP was significantly higher in the assigned sleep period versus outside the period. The trough of mean IOP occurred just before the bedtime, and then IOP gradually increased and peaked at the end of the 8-hour assigned sleep period. The difference between the trough and peak IOP was 3.5 +/- 0.7 mm Hg (mean +/- SEM, n = 25). Within the assigned sleep period, the average IOP determined under illumination was significantly higher than the average IOP preceding the illumination. CONCLUSIONS: Elevation of IOP occurred during the assigned sleep period with two 1-hour light exposures of moderate intensity. Environmental light at night had no significant effect on the nocturnal IOP elevation in healthy young adults.

Adolescent↗

Indocyanine green angiography of central serous chorioretinopathy.

BACKGROUND: Fluorescein angiography has not been particularly useful in studying the choroidal vasculature because of limited fluorescence transmission through the retinal pigment epithelium (RPE). Indocyanine green (ICG), a dye that absorbs and fluoresces in the near-infrared range and does not leak extensively through the choriocapillaries, because of its highly protein-bound nature, allows improved imaging of the choroid compared with fluorescein angiography. This study was performed to evaluate changes in the choroidal circulation in the eyes of patients with central serous chorioretinopathy (CSCR) using ICG angiography. METHODS: We prospectively performed ICG angiography and fluorescein angiography in 41 eyes with classic or chronic CSCR (diffuse retinal pigment epitheliopathy) to investigate the choroidal abnormalities. RESULTS: The ICG angiographic studies revealed choroidal staining in all eyes of the two forms of CSCR. Classic CSCR (35 eyes), when compared with the chronic form (6 eyes), were associated with more RPE leakage (89% vs 33%; p = 0.008), more prominent ischemic lobules (69% vs 0; p = 0.003), and less late phase hypofluorescent spots (46% vs 100%; p = 0.02). CONCLUSIONS: Choroidal hyperpermeability may be a causative factor of acute or chronic CSCR and may help in the diagnosis of atypical cases of CSCR. The differences in the results between these two types of CSCR using ICG angiography, allowed for a better understanding of the choroidal hemodynamic change than fluorescein angiography.

Adult↗

Increased interleukin-6 in aqueous humor of neovascular glaucoma.

PURPOSE: To demonstrate the involvement of proinflammatory cytokines in intraocular neovascularization by detecting the presence of interleukin (IL)-6, IL-2, and tumor necrosis factor (TNF)-alpha in aqueous humor and serum of patients with neovascular glaucoma (NVG) secondary to central retinal vein occlusion (CRVO). METHODS: According to the grade of iris neovascularization (NVI), patients with CRVO were divided into three groups: CRVO without NVI, CRVO with NVI, and CRVO with regressed NVI. Healthy patients with cataract were enrolled as control subjects. Enzyme-linked immunosorbent assay was used to quantitate the concentrations of the cytokines IL-6, IL-2, and TNF-alpha in aqueous humor and serum from patients with NVG and control subjects. RESULTS: In serum, the levels of IL-6, IL-2, and TNF-alpha did not differ among groups. In aqueous humor, only IL-6 showed significant change among groups. IL-6 levels in aqueous humor of group 2, CRVO with NVI (1532.0+/-221.1 pg/ml; P < 0.001), and group 3, CRVO with regressed NVI (234+/-154.6 pg/ml; P < 0.001), were significantly higher. There was no significant difference in IL-6 levels between the control group (26.4+/-21.8 pg/ml) and group 1 (15.6+/-0.9 pg/ml). CONCLUSIONS: The inflammatory cytokine IL-6 in aqueous humor increased spatially and temporally correlated with the grade of NVI in patients of NVG secondary to CRVO. The aqueous IL-6 increased in NVI and decreased after vessels regressed. It is possible that the significantly higher level of IL-6 was due to intraocular synthesis because of the minimal change in serum. The increased level of IL-6 may have a putative role along with other angiogenic factors in angiogenesis of NVG as a possible predictor of NVI.

Aged↗

Effects of latanoprost 50 micrograms/ml on Chinese patients with primary open-angle glaucoma and ocular hypertension.

BACKGROUND: This study was designed to determine the efficacy and safety of latanoprost 50 micrograms/ml in Chinese patients with primary open-angle glaucoma (POAG) and ocular hypertension (OH). METHODS: A 14-day randomized, double-masked, parallel-group study comparing topical latanoprost with placebo was followed by a 10-week, one-armed, open-labeled latanoprost treatment study. Intraocular pressure (IOP), visual function, ocular manifestations and miscellaneous adverse effects were evaluated at baseline, and days 1, 7, 14, 15, week 6 and week 12 visits. RESULTS: Twenty-six eligible patients were enrolled in the study. The mean IOP was significantly reduced from baseline only in the latanoprost-treated eyes during the first study period (p = 0.003 on day 1; p = 0.004 on day 7; p < 0.001 on day 14). Meanwhile, the mean IOP was significantly lower in the latanoprost-treated eyes than that in the placebo-treated eyes (p = 0.03 on day 1; p = 0.001 on days 7 and 14). Eyes in both groups showed significantly reduced IOP at each visit of the secondary 10-week latanoprost treatment period, with a mean decrease of 6.12 mmHg. The IOP-lowering effect showed no diminution throughout the study course. Conjunctival hyperemia occurred in 16 of all patients who underwent latanoprost treatment and was the most frequent adverse effect observed. No patient withdrew from the study because of intolerable side-effects. CONCLUSIONS: Topical latanoprost is effective in reducing IOP for patients with POAG and OH. The pressure-lowering effect lasts for at least 24 hours after 1 drop instillation and no drift of effect is noted during this 12-week study. Conjunctival hyperemia was the most common side-effect, which was mild in degree and recovered after discontinuation of the medication.

Adult↗

Twenty-four-hour pattern of intraocular pressure in the aging population.

PURPOSE: To characterize the 24-hour pattern of intraocular pressure (IOP) in a sample of the aging human population. METHODS: Twenty-one healthy volunteers 50 to 69 years of age were housed in a sleep laboratory for 24 hours. Experimental conditions were strictly controlled with a 16-hour light period and an 8-hour dark period. Sleep was encouraged in the dark period. Intraocular pressure was measured using a pneumatonometer every 2 hours (total of 12 times). Measurements were taken in both the sitting position and the supine position during the light/wake period but only in the supine position during the dark period. RESULTS: When the sitting IOP data from the light/wake period and the supine IOP data from the dark period were considered, elevation and reduction of IOP occurred around the scheduled lights-off and lights-on transitions, respectively. Mean IOP in the dark period was significantly higher than mean IOP in the light/wake period. The trough appeared at the end of the light/wake period, and the peak appeared at the beginning of the dark period. The magnitude of trough-peak difference was 8.6+/-0.8 mm Hg (mean +/- SEM). Cosine fits of 24-hour IOP data showed a significant 24-hour rhythm. When IOP data from just the supine position were analyzed, the trough-peak IOP difference was 3.4+/-0.7 mm Hg, with similar clock times for the trough and the peak. Cosine fits of supine IOP data showed no statistically significant 24 hour rhythm. CONCLUSIONS: Nocturnal elevation of IOP occurred in this sample of the aging population. The trough of IOP appeared at the end of the light/wake period, and the peak appeared at the beginning of the dark period. The main factor in the nocturnal IOP elevation appeared to be the shift from daytime upright posture to supine posture at night.

Aged↗

Delayed-onset of Pseudomonas infection in a hydroxyapatite orbital implant: a case report.

Hydroxyapatite (HA) orbital implant, a multiple porous coralloid-like material, is frequently used in orbital reconstruction after enucleation or evisceration surgery. HA implants contain multiple interconnected pores in which rich fibrovascular tissue ingrowth could theoretically help to resist infection. Infection of hydroxyapatite implants are rare. Most HA implant infections occur before complete vascularization. We present this first case in Taiwan of delayed-onset Pseudomonas infection five years after receiving the HA implant. There was not much improvement after intensive medications, so removal of the implant was finally performed. The pathology study disclosed diffuse inflammatory cell infiltration in the whole implant with a necrotic central core. Rich fibrovascular ingrowth was also noted. Once a porous HA implant is infected, the infection is difficult to control and becomes more severe due to the dead space of the interconnected pores. Removal of the implant seems to be the only successful treatment modality.

Adult↗

Solar retinopathy: a case report.

Sun-gazing is the main cause of solar retinopathy. A 20-year-old inebriated man lying in a park gazed at the sun for approximately three hours at noon. Forty-eight hours after sun-gazing, the patient experienced the symptoms of blurred vision, erythropsia, and central scotoma in the left eye. Visual acuity decreased from 6/6 to 6/60 in the left eye and fundi examinations showed a round, yellowish-white discoid lesion on the left fovea and a smaller one on the right fovea. Fluorescein angiography showed early dye leakage in the fovea of the left eye, that increased gradually in size and became fuzzy at the foveal border in the late phase. A small, central scotoma of the left eye was also found in the visual field test. One month later, the lesion in the fovea of the left eye became smaller and was surrounded by a coarse pigmented halo. Fluorescein angiography showed a window defect in the retinal pigment epithelium. Visual field testing disclosed that the central scotoma persisted, but became smaller. Six months after sun-gazing, a lamellar hole in the fovea of the left eye was detected by optical coherence tomography. The visual acuity was 6/6 in the right eye and 6/60 in the left eye, and was unchanged at the end of the six-month follow-up period.

Adult↗