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Biomedical subjects

W K Chow

Publications and source records attributed to W K Chow.

15 recordsLinked to original sources
PubMed2001

Efficacy of endoscopic isotonic saline-epinephrine injection for the management of active Mallory-Weiss tears.

Therapeutic endoscopy with isotonic saline-epinephrine (ISE) injection is a convenient and widely used procedure for hemostasis in upper gastrointestinal bleeding. We retrospectively evaluated 36 patients (from January 1996 to April 1999) who had been diagnosed with recent or active bleeding due to Mallory-Weiss tears in emergency endoscopic examination. The endoscopic hemostatic method with ISE injection was performed in 15 of 36 patients. The other 21 patients received conservative treatment with hemodynamic support. Patient's clinical data, laboratory data, transfusion requirements, endoscopic findings, and length of hospital stays were evaluated. Initial hemoglobin was significantly lower in the ISE group than the conservative treatment group (9.74 +/- 2.86 g/dL vs. 12.57 +/- 2.80 g/dL, respectively; p < 0.01). Mean transfusion requirements were significantly higher in the ISE group than the conservative treatment group (7.26 +/- 8.78 units vs. 2.85 +/- 6.21 units, respectively; p < 0.1). Patients in the ISE group were supposed to be having a more severe bleeding episode. Most patients achieved initial hemostasis in the ISE group and the conservative treatment group (93% and 95%, respectively). The rebleeding rate was also similar in both groups (1 in 15 in the ISE group and I in 21 in the conservative treatment group). There was no significant difference in length of hospital stay and rebleeding between these two groups (3.47 +/- 1.92 days vs. 2.47 +/- 1.47 days, respectively: p = 0.89). The endoscopic ISE injection is an inexpensive, simple, convenient therapeutic method and it can achieve initial hemostasis for active Mallory-Weiss tears.

Adult↗
PubMed2001

Endoscopic stenting in the treatment of bile leakage after laparoscopic cholecystectomy.

BACKGROUND: Bile leakage is one of the most common complications after laparoscopic cholecystectomy surgery, and biliary decompression is a key factor in treatment. We retrospectively investigated 6 patients with bile leakage after laparoscopic cholecystectomy who were treated with endoscopic stent. METHODS: From March 1995 to May 1999, six patients (4 men and 2 women) aged 30-64 years (mean, 51 years) with bile leakage after laparoscopic cholecystectomy were enrolled. Biliary stent (10 French, 6-10 cm) placement with (n = 4) or without (n = 2) sphincterotomy was attempted. The symptoms, results and outcomes were reviewed. RESULTS: The interval from operation to presentation of bile leakage ranged from 1 to 10 days. Bile leakage was detected from cystic duct stump in 5 patients (83%) and from right IHD in 1 patient (17%). Plastic stent placement was successfully in all patients. Endoscopic stenting healed bile leakage successfully in 5 cases (83%). One patient required surgical correction due to persistent bile leakage. The mean duration between stent placement and cessation of bile leakage was 6.8 days (range 1 to 24 days). CONCLUSIONS: Endoscopic stenting is a safe, rapid and effective treatment for bile leakage after laparoscopic cholecystectomy.

Adult↗
PubMed1998

Molecular identification of the lobster muscle protein tropomyosin as a seafood allergen.

Crustaceans are a major cause of seafood allergy. Recent studies have identified tropomyosin as the major allergen in shrimp. However, such data are lacking in other crustaceans. In the present study lobster allergens were identified and characterized by molecular cloning, sequencing, and expression. An IgE-reactive complementary DNA clone of 2 kilobase pairs (kb) was identified by screening an expression library of the spiny lobster Panulirus stimpsoni using sera from subjects with crustacean allergy. Expression and sequencing of this clone showed that it has an opening reading frame of 274 amino acids, coding for a 34-kDa protein designated as Pan s I. In addition, we expressed the fast muscle tropomyosin from the American lobster Homarus americanus and found that this protein, coined Hom a I, was also recognized by IgE from patients with crustacean allergies. The deduced amino acid sequences of Pan s I and Hom a I, which are the first identified lobster allergens, show significant homology to shrimp tropomyosin. Sera from subjects with crustacean allergies, when preabsorbed with recombinant proteins Pan s I or Hom a I, lost their IgE reactivity to muscle extract of P. stimpsoni and H. americanus. Preincubation of crustacean allergy sera with the recombinant shrimp tropomyosin Met e I also removed their IgE reactivity to lobster muscle extracts. The results suggest that patients with allergic reactions to crustaceans have common and possibly cross-reactive IgE-reactive epitopes in lobster and shrimp.

Allergens↗
PubMed1996

IgE reactivity against a cross-reactive allergen in crustacea and mollusca: evidence for tropomyosin as the common allergen.

BACKGROUND: Although cross-reactivity between mollusks and other crustaceans in shrimp-sensitive subjects has been reported, the mechanism of this allergenic cross-reactivity has not been studied in detail. OBJECTIVE: To investigate this cross-reactivity in vitro, we have taken advantage of a complementary DNA that expresses tropomyosin, the immunodominant shrimp allergen. METHODS: Serum IgE from nine patients with known anaphylaxis to shrimp and five normal volunteers were analyzed by immunoblotting against 13 distinct crustaceans and mollusks. As additional antigens, muscle preparations were isolated from grasshopper, cockroach, fruit fly, chicken, and mouse. RESULTS: Sera from all patients, but not control subjects, reacted specifically with a 38 kd protein in all crustaceans and mollusks studied. In addition, 8 of 9 sera from patients, but from none of the normal control subjects, recognized proteins of various other molecular weights among the mollusk extracts studied. The 38 kd protein was identified as tropomyosin and was shown to share immunodominant epitopes among all species of crustaceans and mollusks tested by specific absorption studies. Moreover, sera from all nine subjects with shrimp allergy demonstrated IgE reactivities against grasshopper, cockroach, and fruit fly but not chicken or murine muscle. CONCLUSION: The allergic epitopes on tropomyosin are conserved among invertebrates including not only shellfish but also insects. This latter observation suggests that persons sensitive to shrimp should undergo further study for potential cross-reactive inhalant or ingested insect sensitivity.

Allergens↗
PubMed1994

Cloning, expression, and primary structure of Metapenaeus ensis tropomyosin, the major heat-stable shrimp allergen.

Shrimp is a common cause of seafood hypersensitivity. To study the mechanism of seafood hypersensitivity at the molecular level, we have determined the primary structure of the major heat-stable allergen of shrimp by cloning, expression, nucleotide sequencing, and amino acid sequence determination of an IgE-reactive cDNA clone, Met e I, isolated from a Metapenaeus ensis expression library in lambda gt 11. We first constructed a cDNA library from the shrimp M. ensis in lambda gt 11. We then screened the library with sera from patients with hypersensitivity reactions to shrimp and identified a positive IgE-reactive clone, designated as Met e I. This cDNA was purified to homogeneity and subsequently expressed in the plasmid pGEX. Serum antibodies from patients with shrimp allergy demonstrated positive IgE reactivity by immunoblotting to a protein encoded by the clone Met e I; sera from nonallergic control subjects were not reactive. The nucleotide sequence of this cDNA clone revealed an open reading frame of 281 amino acid residues, coding for a protein of 34 kd. Comparison of the Met e I amino acid sequence with the Genbank database showed that Met e I is highly homologous to multiple isoforms of tropomyosin.

Allergens↗
PubMed1987

Byssinosis and other respiratory problems in the cotton industry of Hong Kong.

Between February 1982 and October 1984, a total of 2,317 workers from all levels of cotton processing--carding, blowing, spinning and weaving--were studied in a citywide cross-sectional survey. The workers were administered the British MRC Questionnaire in local dialect and their pre- and postshift lung functions were assessed by portable spirometers. The prevalence of byssinosis for the whole industry was 2.3%, being much greater in the more dusty processes (blowing and carding, 5.6%; weaving 1.6%). Even more important was the prevalence of chronic obstructive airways disease (COAD) (13.8%) and a combination of nonspecific respiratory symptoms (10.0%), characterized by chest tightness and dyspnea, but not related to any specific day of the week such as those seen in typical byssinosis. The importance of these two large groups of respiratory problems in relation to byssinosis and the pathogenesis of respiratory diseases in people exposed to cotton dust is discussed.

Adult↗
PubMed1987

Mental health and work stress: a comparison of response patterns in executives and clerical workers in Hong Kong.

Mental health and work stress among 344 clerical (and secretarial) workers and 185 executives (96 managers and 89 executives) in Hong Kong was studied. No overall difference was found between clerical workers and executives in mental health and coping ability when sex was controlled for. Clerical workers, however, reported fewer interests, more problems in accepting others' values, and more dissatisfaction with work context. Female managers/executives were shown to be a high risk group, reporting more problems in mental health, coping, and work context than their male counterparts. Mental health was strongly associated with each of the work stress factors studied. A significant interaction between sex and nature of job was noted in predictors of mental health. The interaction of coping, context, and mental health is discussed.

Adaptation, Psychological↗
PubMed1986

An economic model of teenage pregnancy decision-making.

In this paper, we model unmarried teenagers' decisions about their pregnancy outcome by considering that the teenager contrasts her expected utility (1) as a married mother, (2) as an unmarried mother, or (3) after abortion. We use cross-sectional data on 297 California teenagers aged 13-19 who were pregnant for the first time between 1972 and 1974. Both Anglo and Mexican-American girls are included. We find that pregnant girls who are eligible for or are receiving public assistance are more likely to give birth and remain unmarried. Teenagers with greater time values are more likely to choose abortion, and Mexican-American girls are more likely to carry their pregnancies to term.

Abortion, Legal↗
PubMed1983

Factors discriminating pregnancy resolution decisions of unmarried adolescents.

Pregnancy resolution decisions of unmarried adolescents were studied with the use of an expected utility decision model that included psychological, background, and economic variables. Discriminant function analysis of the decision to have an abortion or to deliver the child indicated that psychological, background, and economic variables each made significant contributions to the successful classification of teenagers (approximately 87.5% of the women were classified correctly). A four-item Abortion Approval Index, the women's perception of the prospective fathers' abortion opinion, personal knowledge of other unmarried teenagers who delivered, self-reported grade average, and receipt of state financial aid in the form of AFDC or Medicaid payments were the most powerful discriminators. For adolescents who chose to deliver, a second discriminant function indicated that only one economic factor--receipt of state financial aid--successfully discriminated those who married from those who became single mothers (approximately 72% of the women were classified correctly). Results are discussed in terms of possible decision strategies and sequences used by adolescents and the value of using a decision framework that incorporates psychological, background, and economic factors.

Abortion, Induced↗