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W Y Wan

Publications and source records attributed to W Y Wan.

7 recordsLinked to original sources
PubMed2005

Access to appropriate information on HIV is important in maximizing the acceptance of the antenatal HIV antibody test.

The universal HIV antibody testing programme was implemented in Hong Kong in September 2001. A survey on acceptance of the test was conducted in the territory's maternal and child health centres in a two-month period. The response rate was 98.2% and 2,669 valid questionnaires were analysed. Seventy per cent (n=1,825) of the respondents indicated their acceptance of the test. A significant association was noted between clients' acceptance and access to HIV information (adjusted odds ratio (OR)=10.45, 95% confidence interval (CI)=6.33-17.26) by means of posters, pamphlets, videos and group talks. Perceived benefits and health care workers' recommendation were the main reported reasons for acceptance, whereas no or low perceived susceptibility was the main reason for refusal. Acceptance was also positively correlated with level of education (adjusted OR=3.99, 95% CI=2.15-7.43) and HIV knowledge (adjusted OR=3.61, 95% CI=2.19-5.93). A high uptake rate (99.6%) reflects that most had the test done eventually despite some initial uncertainty. It is concluded that access to appropriate HIV information was important to maximize the acceptance of the programme.

Adolescent↗
PubMed1999

A recurring two-hydrogen-bond motif incorporating a serine or threonine residue is found both at alpha-helical N termini and in other situations.

Side-chain hydroxyl residues in protein crystal structures often form hydrogen bonds with main-chain atoms. The most common bond arrangement is a four to five residue motif in which a serine or threonine is the first residue forming two characteristic hydrogen bonds to residues ahead of it in sequence. We call them ST-motifs, by analogy with the term Asx-motif we suggested for the related motifs with aspartate and asparagine residues. ST-motifs are common, there being just under one and a half in a typical protein subunit. Asx-motifs are even more common, such that 9 % of the residues of an average protein consist of Asx or ST-motifs. Of the ST-motifs, three-quarters are at helical N termini, and the rest occur by themselves or in conjunction with beta-bulge loops. A third of all alpha-helices have either ST-motifs or Asx-motifs at their N termini. Previous work has emphasised the occurrence of the capping box at alpha-helical N termini, but the capping box occurs in only 5 % of alpha-helical N termini; also, we point out that it can be regarded as a subset of the ST-motif (or, occasionally, of the Asx-motif). By comparing related sequences, the rates which amino acid residues at the first position of ST or Asx-motifs interchange during evolution are examined. Serine <==> threonine, and aspartate <==> asparagine, interchange is rapid; inter-pair exchange is slower, but much faster than exchange with other amino acid residues. This is consistent with the general similarity of ST-motifs and Asx-motifs combined with some subtle structural differences between them that are described.

Amino Acid Sequence↗
PubMed1999

A natural grouping of motifs with an aspartate or asparagine residue forming two hydrogen bonds to residues ahead in sequence: their occurrence at alpha-helical N termini and in other situations.

Examination of the ways side-chain carboxylate and amide groups in high-resolution protein crystal structures form hydrogen bonds with main-chain atoms reveals that the most common category is a two-hydrogen-bond four to five residue motif with an aspartate or asparagine (Asx) at the first residue, for which we propose the name Asx-motif. Similar motifs with glutamate or glutamine residues at that position are rare. Asx-motifs occur typically as (1) a common feature of the N termini of alpha-helices called the Asx N-cap motif; (2) an independent motif, usually a beta-turn with an appropriately hydrogen-bonded Asx as the first residue; and (3) a motif incorporated in a beta-bulge loop. Asx-motifs are common, there being just under two-and-a-half in an average-sized protein subunit; of these, about 55 % are Asx N-cap motifs. Because they occur often in many situations, it seems that these motifs have an inherent propensity to form on their own rather than just being a feature stabilised at the end of a helix. Asx-motifs also occur in functionally interesting situations in aspartyl proteases, citrate synthase, EF hands, haemoglobins, lipocalins, glutathione reductase and the alpha/beta hydrolases.

Amino Acid Sequence↗
PubMed1998

Diffuse cavernous hemangioma of the rectum complicated by invasion of pelvic structures. Report of two cases.

PURPOSE: We present two cases of diffuse cavernous hemangioma of the rectum that invaded the pelvic structures. METHODS: Two young women suffering from intermittent rectal bleeding were studied using computed tomography and magnetic resonance imaging. RESULTS: Beside the rectal hemangioma, computed tomography and magnetic resonance imaging revealed that the pelvic ureter and the iliac vessels were each eroded by the tumor that produced symptoms in these two patients. CONCLUSION: Computed tomography and magnetic resonance imaging permit direct visualization for tumor staging and also for recognition of any pelvic structure invasion, which facilitate preoperative assessment of diffuse cavernous hemangioma of the rectum.

Adult↗
PubMed1997

Tuberculoma of the liver presenting as a hyperechoic mass on ultrasound.

An unusual case of hepatic macronodular tuberculoma is presented. As demonstrated by CT, the tuberculoma replaced the entire lateral segment of the left lobe of liver and resembled an infiltrative tumour. On ultrasound, the tuberculoma presented as a hyperechoic lesion, in contrast to a round hypoechoic mass which is usually seen in this condition. Hepatic macronodular tuberculomas are not uncommonly misdiagnosed as primary or secondary liver tumours by imaging studies, and the definite diagnosis is usually established by liver biopsy. The prognosis of hepatic macronodular tuberculoma is usually very good with effective treatment.

Adult↗