Biomedical subjects

J Y Yang

Publications and source records attributed to J Y Yang.

At least 73 records · Page 4Linked to original sources

PubMed1996

Intrascar excision for persistent perioral hypertrophic scar.

Scar revision is almost a daily work of plastic surgeons, but sometimes it is a challenge to them. Persistent hypertrophic scar in the perioral area is very difficult to treat because of its anatomic location. Many methods of scar removal, including simple scar revision, Z- or W-plasty, V-Y or Y-V flap, local cutaneous flaps, etc., may not be suitable to remove the perioral scar. The specially designed intrascar excision technique is a good method to solve this problem. The long-term follow-up, up to 5 years, in this clinical series revealed that this method does not distort the perioral anatomy and produces satisfactory aesthetic results.

Adolescent↗

PubMed1996

Acute lung injury after phosgene inhalation.

Phosgene (COCl2) is a colorless oxidant gas which is heavier than air and the lethal exposure dose (LC50) in humans is 500 ppm/min. This gas was originally manufactured as an agent for chemical warfare during World War I and there had been a great deal of studies on phosgene poisoning during the early years of industrial use. It is still widely used in the synthesis of chemicals and plastics. In the modern era, however, phosgene poisoning is relatively uncommon except in accidental exposures. In Korea, there has been no report about lung injury from phosgene inhalation. We present a clinical experience with six patients accidentally exposed to phosgene.

Accidents, Occupational↗

PubMed1996

Comparison between thallium-201 and technetium-99m-tetrofosmin uptake with sustained low flow and profound systolic dysfunction.

UNLABELLED: Technetium-99m-tetrofosmin uptake was compared to that of 201Tl in the setting of low flow and systolic dysfunction. METHODS: In nine open-chested dogs, a severe left anterior descending (LAD) coronary artery stenosis resulted in a 54.3% mean flow reduction and decreased left ventricular thickening from 21% +/- 1% to -3 +/- 2%. After 30 min, 37 MBq (1 mCi) of 201Tl and microspheres were injected and initial and 2-hr redistribution images acquired. Two hours later, 370 MBq (10 mCi) of 99mTc-tetrofosmin and microspheres were injected and an image was obtained. LAD: left circumflex (LCX) count ratios for both tracers and flows were calculated by well counting postmortem, and 201Tl and 99mTc-tetrofosmin defect magnitudes were determined by quantitative image analysis. RESULTS: LAD:LCx flow ratios were similar during 201Tl and 99mTc-tetrofosmin injections (0.48 +/- 0.04 versus 0.49 +/- 0.05, p = n.s.). Final 201Tl activity (0.66 +/- 0.04) was significantly higher than 99mTc-tetrofosmin (0.55 +/- 0.05; p < 0.05). LAD/LCx 99mTc-tetrofosmin image defect count ratio was similar to 201Tl defect count ratio on the initial rest 201Tl scan (0.57 +/- 0.03 versus 0.56 +/- 0.02, p = ns), but significantly less than 201Tl defect count ratio at 2 hr (0.57 +/- 0.03 versus 0.65 +/- 0.02, p < 0.05). CONCLUSION: In a low-flow model with profound systolic dysfunction, myocardial 99mTc-tetrofosmin uptake ( > 50%) reflective of viability was observed in the asynergic zone perfused by the stenotic LAD.

Animals↗

PubMed1996

Major burns in pregnancy.

From June 1986 to May 1991, there were 1,931 patients to be treated for burns in Linkou Burn Unit, at the Chang Gung Memorial Hospital. Seven patients, aged 24 to 32 years, were pregnant and had burns greater than 10% of total body surface area (TBSA). The severity of the dermal injuries was diagnosed as partial or full thickness. Patient's gestational ages ranged from 8 to 38 weeks. Five patients had normal deliveries at term; one patient had intrauterine fetal death 7 weeks after the burn injury, and one patient had premature labor at gestational age of 33 weeks. Termination of the pregnancy was never done in our series. Active medical treatment together with conservative wound care should be the standard in each trimester of pregnancy.

Abortion, Spontaneous↗

PubMed1995

Enhancer-independent variants of phage Mu transposase: enhancer-specific stimulation of catalytic activity by a partner transposase.

Assembly of the functional tetrameric form of phage Mu transposase (A protein) requires specific interactions between the Mu A monomer and its cognate sequences at the ends of the Mu genome (attL and attR) as well as those internal to it (the enhancer element). We describe here deletion variants of Mu A that show enhancer-independence in the assembly of the strand cleavage complex. These deletions remove the amino-terminal region of Mu A required for its interactions with the enhancer elements. The basal enhancer-independent activity of the variant proteins can be stimulated by a partner variant harboring an intact enhancer-binding domain. By exploiting the identical att-binding, and nonidentical enhancer-binding specificities of Mu A and D108 A (transposase of the Mu related phage D108), we show that the stimulation of activity is enhancer-specific. Taken together, these results suggest that the domain of Mu A that includes the enhancer-interacting region may exert negative as well as positive modulatory effects on the strand cleavage reaction. We discuss the implications of these results in the framework of a recent model for the assembly of shared active sites within the Mu A tetramer.

Attachment Sites, Microbiological↗

PubMed1995

A domain sharing model for active site assembly within the Mu A tetramer during transposition: the enhancer may specify domain contributions.

The functional configuration of Mu transposase (A protein) is its tetrameric form. We present here a model for the organization of a functional Mu A tetramer. Within the tetramer, assembly of each of the two active sites for Mu end cleavage requires amino acid contributions from the central and C-terminal domains (domains II and III respectively) of at least two Mu A monomers in a trans configuration. The Mu enhancer is likely to function in this assembly process by specifying the two monomers that provide their C-terminal domains for strand cleavage. The Mu B protein is not required in this step. Each of the two active sites for the strand transfer reaction is also organized by domain sharing (but in the reverse mode) between Mu A monomers; i.e. a donor of domain II (also the recipient of domain III) during cleavage is a recipient of domain II (and the donor of domain III) during strand transfer. The function of the Mu B protein (which is required at the strand transfer step) and that of the enhancer element may be analogous in that their interactions with Mu A (domain III and domain I alpha respectively) promote conformations of Mu A conducive to strand cleavage or strand transfer.

Bacteriophage mu↗

PubMed1995

Glycosylation, dimerization, and heparin affinity of lipoprotein lipase in 3T3-L1 adipocytes.

The relationship between glycosylation, dimerization, and heparin affinity of lipoprotein lipase (LPL) was studied in 3T3-L1 adipocytes. Three forms of LPL subunits were found in normal cells; totally endo H-resistant (57 kDa), partially sensitive (54 kDa), and totally sensitive (51 kDa) forms. LPL in normal cells was active, dimeric, and showed high affinity for heparin. LPL in cells treated with tunicamycin, preventing the transfer of N-linked oligosaccharide chain, was unglycosylated (51 kDa) and inactive. LPL proteins were found as an aggregate, and had low affinity for heparin. After treatment with castanospermine, an inhibitor of ER glucosidase I, 80% of LPL activity was inhibited. Most of LPL proteins were totally endo H-sensitive, present as an aggregate, and had low affinity for heparin. LPL in cells treated with deoxymannojirimycin, an inhibitor of Golgi mannosidase I, was active, dimeric, and had high affinity for heparin as in normal cells. But LPL subunits were all endo H-sensitive. These results suggest that core glycosylation and subsequent removal of glucose residue is required, but processing after Golgi mannosidase I is not necessary for dimerization and acquisition of high heparin affinity of LPL.

3T3 Cells↗

PubMed1995

Non-ketotic hyperosmolar coma complicating steroid treatment in childhood nephrosis.

Two nephrotic children treated with prednisone developed steroid-induced diabetes and non-ketotic hyperosmolar coma (NKHC). Both patients presented with convulsions, coma and shock. The glucose concentration of the cerebrospinal fluid was 425 mg/dl and 622 mg/dl, respectively. Both patients had no diabetic family history, but had been treated with prednisone for 4 and 8 months, receiving total doses of 6.6 and 10.8 g, respectively. Despite conventional therapy, both patients deteriorated rapidly and died several hours later. Steroid-induced diabetes associated with NKHC is a rare but serious complication of steroid therapy.

Adolescent↗

PubMed1995

[Adherence of the surface protein P(1) of Streptococcus mutans MT(6)R(Serotype C).].

In this study,the surface protein P(1) of Streptococcus mutans MT(6)R(Serotype C) was extracted from the culture supernants,purified by PAGE,identified by the standard antisera and labelled by with (131)I.The adherence of (131)I protein P(1)((131)I-P(1)) to the saliva-coated hydroxyaptite (S-HA) of the CF (caries-free,22,DFS=0) were studied.The adhesion of (131)I-P(1) to the S-HA promoted a greater extent than that to the HA treated with buffer and bovine serum albumin(P<0.01).This result suggested that protein P(1) may be one of the important adhesins of S.mutans.

English Abstract↗

PubMed1995

Characterization of daytime sleepiness and psychomotor performance following H1 receptor antagonists.

BACKGROUND: While first generation H1-receptor antagonists are widely used, there are relatively few data describing their comparative effects on subjective daytime sleepiness and psychomotor performance. OBJECTIVE: To compare the effects of first generation H1 receptor antagonists on subjective daytime sleepiness and psychomotor performance. METHODS: We conducted two single-dose, cross-over studies. In the first, we validated our methodology in 18 healthy subjects by examining the response to diphenhydramine (50 mg), terfenadine (60 mg), and placebo. In the second trial, we evaluated the relative effects following diphenhydramine (50 mg), diphenhydramine (25 mg), chlorpheniramine (4 mg), and placebo. Psychomotor tests included choice reaction time, hand steadiness, and a test that divided attention between tracking and reaction time. Introspective drowsiness was measured using a visual analog scale and the Stanford Sleepiness Scale. Assessments were made prior to dosing and at one, three, and five hours after dosing; a 7-hour post-drug assessment was included in the second trial. RESULTS: In the first trial, 50 mg diphenhydramine produced significant impairment relative to placebo in both subjective and objective assessments (P < .05). Responses following terfenadine did not differ from placebo. In the second study, all three regimens produced subjective and objective soporific effects to a significantly greater degree than placebo. For example, significant introspective sleepiness was noted three hours following all three regimens (P < .05) and slower choice reaction times were noted one and three hours after dosing (P < .05). The general rank order of effects was diphenhydramine (50 mg), followed by diphenhydramine (25 mg), followed by chlorpheniramine (4 mg). Significant differences among the three regimens were, for the most part, confined to greater soporific effects from diphenhydramine relative to chlorpheniramine (P < .05). CONCLUSIONS: Taken together, our observations confirm that subjective and objective measures of sleepiness and psychomotor performance occur following single doses of diphenhydramine and chlorpheniramine, but not terfenadine. Differences in soporific effects do exist among regimens of first-generation compounds.

Adolescent↗

PubMed1994

Inhibition of 3'azido-3'deoxythymidine-resistant HIV-1 infection by dehydroepiandrosterone in vitro.

Human immunodeficiency virus type 1 (HIV-1) isolated from patients with acquired immunodeficiency syndrome (AIDS) shows resistance to 3'azido-3'deoxythymidine (AZT) after one or two years of treatment. AZT also has significant toxic side effects, further limiting its use in the therapy of HIV-1-infected individuals. Dehydroepiandrosterone (DHEA) has been shown to have a broad spectrum of biological functions, to be bioavailable orally and to be relatively nontoxic. Epidemiological studies provide evidence that reduced serum levels of DHEA are related to the progression of AIDS in HIV-1 infection. DHEA has also been shown to inhibit HIV-1 replication in vitro and block HIV-1 reactivation from chronically infected cell lines. However, there have been no reports on the ability of DHEA to inhibit the replication of AZT-resistant strains of HIV-1. We investigated whether DHEA treatment could inhibit replication of AZT-resistant strains of HIV-1. Addition of DHEA to MT-2 cell cultures infected with either AZT-sensitive or AZT-resistant isolates of HIV-1 resulted in dose-dependent inhibition of HIV-1-induced cytopathic effect and suppression of HIV-1 replication as measured by accumulation of reverse transcriptase activity. At a concentration as low as 50 microM, DHEA reduced AZT-resistant HIV-1 replication over 50 percent as measured by cytopathic effect and accumulation of reverse transcriptase activity. This study provides evidence that DHEA can inhibit the replication of AZT-resistant as well as wild-type HIV-1. Since the main targets for DHEA are metabolic and cellular signaling pathways leading to HIV-1 replication-activation, DHEA should be effective against multidrug-resistant strains of HIV-1. Combined with recently discovered immunoregulatory properties, the finding that DHEA is able to inhibit replication of both wild-type and AZT-resistant HIV-1 suggests that in vivo DHEA may have a much broader spectrum of action than originally anticipated.

Cytopathogenic Effect, Viral↗

PubMed1994

Reverse dorsometacarpal flap in digits and web-space reconstruction.

Skin defects in some areas of the digits are difficult to reconstruct, such as the ulnar aspect of the little or ring finger, radial aspect of the index, dorsal or volar aspect of fingers with proximal interphalangeal or metacarpophalangeal joint involvement, and proximal phalanx of the thumb. Moderate or severe contracture of the web space and multiple finger injuries without an available cross-finger flap are also a challenge to reconstructive surgeons. The reverse dorsometacarpal flap presents an option for reconstruction because of these difficulties. It is reliable and versatile in design. The donor site can be closed primarily provided the flap is less than 2 cm wide.

Adult↗

PubMed1994

Electrical burns associated with head injuries.

Although electrical burns account for a small portion of all thermal injuries, their treatment becomes more complex when associated with injuries of other organs. From July 1987 through December 1991, 8 of 249 burned patients sustained electrical burns associated with head injuries. The mean total body surface area burned was 19% (range, 2%-45%). Computed tomographic (CT) scans of the brain revealed that six patients with moderate to severe head injuries had intracranial hemorrhage including three cases of intracerebral hematoma and another three cases of epidural hematoma. Half of these patients underwent surgical intervention for removal of intracranial hematomas and a compound depressed fracture segments of the skull, and the others were treated conservatively. All the patients progressively recovered consciousness with Glasgow Coma Scale scores of 14 or more and minimal neurologic sequelae. The combination of early detection and prompt removal of life-threatening intracranial hematomas with aggressive support of electrical victims who appear dead would minimize the morbidity and mortality in patients with electrical burns and head injuries.

Adolescent↗

PubMed1994

Enhanced tuberoinfundibular dopaminergic neuron activity in thyroidectomized, ovariectomized and estrogen-treated rats with hyperprolactinemia.

The involvement of the tuberoinfundibular dopaminergic (TIDA) neurons in the genesis of hyperprolactinemia in female thyroidectomized rats treated with estrogen was the focus of this study. Rats that were ovariectomized (3 weeks), thyroidectomized (2 weeks) and treated with estrogen for 6 days had a 5- to 10-fold increase in serum prolactin (PRL) levels, while the rats receiving the same treatments but without estrogen had lower PRL levels. The activity of TIDA neurons, using dihydroxyphenylacetic acid (DOPAC) concentration or the DOPAC/dopamine (DA) ratio in the median eminence (ME) as an index, was increased and decreased in estrogen-treated and untreated rats, respectively. The increases in serum PRL level and the activity of TIDA neurons were dependent on the duration of thyroidectomy and could both be lowered by daily injection of thyroid hormone (20 or 100 micrograms/kg b.w. thyroxine, i.p.) for 12 days in a dose-dependent manner. Using dihydroxyphenylalanine (DOPA) accumulation in the ME as another index, we also found an increased DOPA/DA ratio in estrogen-treated hypothyroid rats, which effect could be reversed by replacement of thyroid hormone. Furthermore, treatments with bromocryptine (3 mg/kg b.w./day, s.c.) for 3 days or with cysteamine (100 mg/kg b.w., s.c.) at 26, 15 and 2 h before the rats were sacrificed lowered both serum PRL level and TIDA neuron activity. Since PRL can exert a short-loop feedback control on its own secretion, these results indicate that the increased serum PRL levels in estrogen-treated hypothyroid female rats should be the cause, but not the result, of the increased activity of TIDA neurons.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1994

Frozen preservation of human amnion and its use as a burn wound dressing.

A method of freezing and sterilizing the human amnion enabled it to be stored at -60 degrees C for more than six months. The membranes were obtained from twenty-four cesarean section mothers without a history of endometritis, premature rupture of their membranes or a positive serology. The elongation and break strength of the membranes were evaluated before and after storage. The membranes as prepared have been utilized on twenty-two wounds of ten burn patients. The results indicate that amnion is quite safe and effective as a biological dressing using this preservation method.

Adult↗

PubMed1994

[Preliminary clinical study on prevention of bone loss in postmenopausal women with kidney invigoration].

The effect of Bushen Migu Ye (BSMGY) on preventing the bone loss in postmenopausal women was observed. 43 healthy women with the menopause within 5 years were randomly divided into the treated and control groups, which were basically similar in age and menopausal time. BSMGY and Rhizoma Dioscoreae decoction was given orally in two groups. Some biochemical parameters related to bone metabolism, serum estradiol and forearm bone density were taken before and after treatment. The results showed that 5 months after BSMGY treatment, the ulnar and radial bone mineral content was higher than that of pretreatmental value (P < 0.05), while in control group this index was continually decreased. The change in bone density were also significant different (P < 0.05). It seems that BSMGY is able to prevent the bone loss in postmenopausal women. In the treated group, ratio of fasting urinary calcium and hydroxyproline to creatinine was lower than that of before treatment and the control group (P < 0.05); the concentration of serum alkaline phosphatase had no significant difference (P < 0.05). This preliminary study suggested that one of the therapeutic mechanism of BSMGY was probably due to declining of bone resorption, without affecting the bone formation in postmenopausal women.

Bone Density↗

PubMed1994

Electrical injury--clinical report of 67 cases.

We have reviewed 67 patients of electrical burns treated at Linkou Burn Center of Chang Gung Memorial Hospital from January 1988 to April 1992. There were 2086 acute burn admissions during this period with the proportion of electrical injuries being 3.2%. Their age ranged from 13 to 68 years, with 61% in the age group of 20 to 40 years. Sixty-two (92.5%) of our patients were males. Over 60% of these injuries were work-related. The proportion of high voltage electrical injuries was over 60% in our series. All deceased patients and those patients with major complications were in the high voltage electrical injuries group. Low voltage injuries did not leave any major sequelae. In a mean follow-up of 2 years, 83% of our patients could return to the previous job or change to another work. The overall mortality was 6%.

Accidents, Occupational↗

PubMed1994

Effect of supernatant of peripheral blood mononuclear cells from nephrotic patients on the sulfated compound synthesis by cultured glomerular epithelial cell.

To identify the role of circulating immune factor(s) in the development of proteinuria, the supernatant of peripheral blood mononuclear cells (PBMC) were obtained from 15 patients with steroid-responsive nephrotic syndrome, and its effect on the synthesis of sulfated compound by cultured rat glomerular epithelial cell (GEC) were studied by 35S, 3H-leucine dual-isotope labelling technique. The result showed that the supernatant of PBMC from 9 patients without steroid treatment increased 35S uptake in GEC (P < 0.01), while there was no significant difference in 35S uptake between the 6 patients treated with prednisone (1.5-2.0 mg/kg.d-1) and 6 normal controls.

Adolescent↗