Search PubMed⌕ Search

Biomedical subjects

A Chang

Publications and source records attributed to A Chang.

At least 235 records · Page 13Linked to original sources
PubMed1990

Skin-derived antileucoproteases (SKALPs): characterization of two new elastase inhibitors from psoriatic epidermis.

Elastase inhibiting activity (EIA) was demonstrated in the epidermis from lesions and in psoriatic scale, whereas normal epidermis did not contain significant EIA. Two new elastase inhibitors were partially purified and characterized using psoriatic scale as a source. The two species (approximate molecular weights 10 and 20 kDa) were shown to be stable, and high-affinity inhibitors of human leucocyte elastase (Ki less than 10(-10) M). No activity against human cathepsin G could be demonstrated. Cultured human keratinocytes were shown to contain EIA activity similar to that found in psoriatic scale. EIA could also be demonstrated in human epidermis following the induction of an experimental inflammatory response by sellotape-stripping. We propose the acronym SKALP (skin-derived antileucoprotease) as a name for these new proteinase inhibitors.

Cells, Cultured↗
PubMed1990

Macrosomic babies.

A review of 3,241 delivery records was made to study the obstetrics and the neonatal outcomes of 129 macrosomic (greater than or equal to 4,000g) babies. They were found to have a nearly 6-fold increase in the neonatal morbidity rate compared with normosomic babies. The emergency Caesarean section rate for nulliparas and parous women with macrosomic babies was 41.3% and 8.4% respectively. Among macrosomic babies, shoulder dystocia was not associated with maternal stature, induction of labour, use of oxytocin or abnormal labour patterns, but was associated with instrumental delivery. Macrosomic babies with shoulder dystocia after instrumental delivery had a higher neonatal morbidity rate than those delivered spontaneously.

Birth Injuries↗
PubMed1990

Elastase-inhibiting activity in scaling skin disorders.

Elastase inhibiting activity (EIA) has been observed in normal skin as a response to surface trauma, immediately following the intra-epidermal accumulation of polymorphonuclear leukocytes (PMN). In order to elucidate the relation between EIA and inflammation, the inhibiting activity was assessed in skin samples of scaling dermatoses (a) without significant inflammation: erythrodermic autosomal recessive lamellar ichthyosis (EARLI), non-erythrodermic autosomal recessive lamellar ichthyosis (NEARLI), X-linked recessive ichthyosis (XLRI) and X-linked dominant chondrodysplasia punctata (XLD-CDP); (b) with predominantly mononuclear cell infiltration: atopic dermatitis; (c) with mixed infiltration of PMN and mononuclear cells: psoriasis and Netherton syndrome. All skin disorders investigated showed an increased EIA as compared with normal skin. Scales from psoriatic lesions, EARLI and Netherton syndrome showed a statistically significant increase in EIA above that observed in other monogenic disorders of keratinization NEARLI, XLRI XLD-CDP and above atopic dermatitis. EIA proved to be an indicator for abnormal keratinization with a marked expression when a mixed infiltrate is present in the skin.

Biopsy↗
PubMed1990

Tetracycline does not affect the trauma- and leukotriene B4-induced intraepidermal accumulation of polymorphonuclear leukocytes.

The transepidermal migration of polymorphonuclear leukocytes is a well established target for antipsoriatic therapies. Tetracycline, although inhibiting the movement of PMN, is not an effective treatment for psoriasis. In contrast to the inhibition of PMN chemotactic response to serum and bacterial products, the leukotriene B4-induced and trauma-induced intraepidermal accumulation of PMN was unaffected by tetracycline.

Adult↗
PubMed1989

Promoting child passenger safety in children served by a health maintenance organization.

A patient education program, based on the health belief model, promoting child passenger safety was developed and implemented at a health maintenance organization. The program included individual counseling by pediatricians, use of audiovisual materials and pamphlets, and (for newborn infants) a home visit by a child safety specialist. Based on parking lot observations, child safety device use increased to greater than 60% in both intervention and comparison-group children 1-4 years of age. During the child health supervision visit, pediatricians can play a leadership role in promoting child passenger safety.

Accident Prevention↗
PubMed1989

Inhibition of Photosystem II Precedes Thylakoid Membrane Lipid Peroxidation in Bisulfite-Treated Leaves of Phaseolus vulgaris.

Exposure of leaves to SO(2) or bisulfite is known to induce peroxidation of thylakoid lipids and to inhibit photosynthetic electron transport. In the present study, we have examined the temporal relationship between bisulfite-induced thylakoid lipid peroxidation and inhibition of electron transport in an attempt to clarify the primary mechanism of SO(2) phytotoxicity. Primary leaves of bean (Phaseolus vulgaris L. cv Kinghorn) were floated on a solution of NaHSO(3), and the effects of this treatment on photosynthetic electron transport were determined in vivo by measurements of chlorophyll a fluorescence induction and in vitro by biochemical measurements of the light reactions using isolated thylakoids. Lipid peroxidation in treated leaves was followed by monitoring ethane emission from leaf segments and by measuring changes in fatty acid composition and lipid fluidity in isolated thylakoids. A 1 hour treatment with bisulfite inhibited photosystem II (PSII) activity by 70% without modifying Photosystem I, and this inhibitory effect was not light-dependent. By contrast, lipid peroxidation was not detectable until after the inhibition of PSII and was strongly light dependent. This temporal separation of events together with the differential effect of light suggests that bisulfite-induced inhibition of PSII is not a secondary effect of lipid peroxidation and that bisulfite acts directly on one or more components of PSII.

Journal Article↗
PubMed1989

Dithranol modulates the leukotriene B4-induced intraepidermal accumulation of polymorphonuclear leukocytes.

Dithranol, with and without the addition of salicylic acid, was applied daily on normal skin according to a short contact protocol as used in the treatment of psoriasis. Sellotape stripping and epicutaneous application of leukotriene B4 (LTB4) were carried out within these pretreated areas. The challenged skin was subsequently biopsied and the intraepidermal accumulation of polymorphonuclear leukocytes (PMN) was quantified using the marker enzyme elastase. Dithranol pretreatment yielded a significant reduction of the LTB4-induced accumulation of PMN, whereas the tape stripping-induced accumulation of PMN was not affected by dithranol pretreatment. The addition of salicylic acid did not significantly enhance the effect of dithranol.

Adult↗
PubMed1989

Migration of polymorphonuclear leukocytes in psoriasis.

A characteristic feature of the early and active psoriatic lesion is the intraepidermal penetration of polymorphonuclear leukocytes (PMN) with the formation of intraepidermal micropustules of Kogoj and microabscesses of Munro, localized in the stratum corneum. In pustular psoriasis the accumulation of PMN dominates the clinical picture. During the last decade our insight into the regulation of the migration of PMN has increased. The properties of the circulating blood PMN and the biochemical nature and biological effects of mediators of inflammation have been studied in detail. Several groups have demonstrated that the transdermal and epidermal migration of PMN following challenge with a chemoattractant is slightly diminished in the clinically uninvolved skin and profoundly decreased in the lesional skin of psoriatics, compared to the responsiveness in normal controls. The molecular nature of this process of tachyphylaxis has not yet been established. However, it has been hypothesised that some mediators of inflammation, cytochrome P-450, endothelial cell function, and protease inhibitors might be of relevance in this respect. This report is a review of the literature on transdermal and epidermal migration of PMN in normal and psoriatic skin. The aim of this review is to clarify further the position of the PMN in the pathogenesis of psoriasis and its role as a target for antipsoriatic treatments.

Cell Movement↗
PubMed1989

Epidermal proliferation and accumulation of polymorphonuclear leukocytes in the psoriatic lesion.

Biopsies were removed from the margin of plaques in 11 untreated psoriatic patients, and 8-microns sections prepared using the cryostat. Alternate sections were stained with H and E to assess the accumulation of polymorphonuclear leukocytes. The remaining sections were stained with the monoclonal antibody Ki67 in order to determine the number of cycling epidermal cells. In areas where polymorphonuclear leukocytes occurred in the stratum Malpighi the number of cycling epidermal cells was relatively low. In contrast, a positive correlation was shown between the density of microabscesses of Munro and the number of cycling epidermal cells. The clinically uninvolved skin of psoriatic patients shows a moderate enhancement of epidermal growth in the absence of any infiltrate. In the lesional skin the recruitment of cycling epidermal cells does not coincide with the invasion of polymorphonuclear leukocytes into the epidermis, but rather follows the penetration of these cells.

Adult↗
PubMed1989

Serum C-reactive protein levels in patients with cervical neoplasia.

Serum C-reactive protein (CRP) levels were determined by enzyme immunoassay in 56 patients with invasive carcinoma of the cervix, 34 patients with cervical dysplasia and 24 women with no evidence of cervical pathology. The logarithmic CRP values were significantly higher in patients with invasive carcinoma when compared with the controls (p less than 0.05). Measurement of serum CRP in cancer patients grouped according to their clinical stages failed to reveal any relationship with the extent of the disease.

C-Reactive Protein↗
PubMed1989

Acitretin monotherapy in acrodermatitis continua Hallopeau.

In a patient affected with acrodermatitis continua Hallopeau, acitretin (Ro 10-1670) monotherapy resulted in a complete clearance of pustulation at a dosage of 45 mg per day. At this dosage the leukotriene B4-induced intraepidermal accumulation of polymorphonuclear leukocytes was markedly inhibited.

Acitretin↗
PubMed1989

Injuries among preschool children enrolled in day-care centers.

In this study, 423 injury incidents among preschool children enrolled in day-care centers reported to the Los Angeles Unified School District during the 2-year period 1983 to 1984 are reviewed. The relative risk of sustaining an injury between boys and girls was 1.5:1. Among sex and age groups, younger boys (2 to 3 years of age) showed the highest injury rate and older girls (4 to 5 years of age) showed the lowest. The overall incidence was 19.7 injuries per 1,000 child-years. The majority of the injuries were minor in severity, and medical attention was recommended in only 12.8% of the injuries. The highest incidence occurred during the late morning period (9 AM to 12 noon). A consumer product was involved in 53.7% of the incidents. Three of four injuries were considered preventable by training and/or education or by the Haddon injury reduction strategies. Additional prospective studies are needed to develop and implement preventive measures.

Accident Prevention↗
PubMed1988

Biosynthesis of the plasma membrane H+-ATPase of Neurospora crassa.

The plasma membrane H+-ATPase of Neurospora is a 100-kDa integral membrane protein which appears, on the basis of hydropathy analysis of its amino acid sequence, to span the lipid bilayer at least eight times. To investigate the assembly and processing of the ATPase, a full-length cDNA has been constructed for use in in vitro transcription and translation experiments. Comparison of three different forms of the ATPase (nascent protein, nascent protein cotranslationally inserted into membranes, and mature protein) revealed no difference in electrophoretic mobility. Furthermore, the nascent and mature forms gave identical peptide patterns after partial proteolysis with Staphylococcus aureus V8 protease, suggesting that the ATPase does not contain an NH2-terminal signal peptide which is cleaved upon membrane insertion. Consistent with this interpretation, the NH2-terminal peptide has been purified from a tryptic digest of the ATPase and found to lack only the initiator methionine residue; the penultimate alanine is acetylated based on analysis by fast atom bombardment mass spectroscopy. Although the ATPase contains one potential site of N-linked glycosylation, its electrophoretic mobility was unchanged following digestion with endoglycosidase H and it did not incorporate [3H]mannose or bind concanavalin A. Thus, the Neurospora plasma membrane-ATPase appears to undergo minimal post-translational processing, and its membrane insertion is probably mediated by internal sequences.

Amino Acid Sequence↗
PubMed1988

Management of illness and temporary disability in children enrolled in day-care centers. The Health House experience.

Alternative care arrangements are often necessary when children enrolled in day-care centers experience illness or temporary disability. To meet this need, a new facility named Health House was established by the Child Development Program of the Pomona (Calif) Unified School District. This report describes the organization, operation, and costs of the program, and reviews the management of 179 episodes of illness or temporary disability in 99 children served by the program during the 1983-1984 school year. The medical conditions of patients cared for were comparable with those seen in physicians' offices as reported in a national survey. The daily cost of care per child for the sponsoring agency was $38. The service enabled an average daily salary saving of $39.80 for the working parent. Health House may serve as a model for the management of illness or temporary disability in children enrolled in day-care centers.

Child Day Care Centers↗
PubMed1988

Monoclonal antibodies against human recombinant tumor necrosis factor: prevention of endotoxic shock.

Six murine monoclonal antibodies, AT-1, 2, 3, 4, 5, and 6 were produced against human recombinant tumor necrosis factor (gamma TNF). AT-1, -2, -3, -4, and -6 were IgG1, and AT-5 was IgG2a. AT-1, -2, and -3 neutralized the activity of gamma TNF (2 X 10(3) U/ml) over a range of dilutions between 5 and 500 micrograms/ml of IgG, while AT-4, -5 and -6 failed to neutralize the activity in these concentrations. All the antibodies showed immunoprecipitating activity for gamma TNF (2 X 10(3) U/ml) over a range of dilutions between 0.5 and 500 micrograms/ml. The AT-6 was weaker than the rest. AT-1, which neutralized gamma TNF activity efficiently, and AT-4, which did not neutralize the activity, were used to protect mice against endotoxic shock. AT-1 protected mice from the lethal effects of endotoxin, while AT-4 failed to do so. AT-1, -2, and -3 also neutralized the activity of human and mouse natural TNF. AT-1, -2, and -3 neutralized the activity of gamma TNF, but not that of lymphotoxin (LT) and interferon (IFN).

Animals↗