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W C Lee

Publications and source records attributed to W C Lee.

At least 163 records · Page 9Linked to original sources
PubMed1996

Estimating life expectancy using an age-cohort model in Taiwan.

OBJECTIVES: Life expectation is a valuable summary index in public health and actuarial science. The life expectancies published in the vital statistics, however, are derived from the "current" rather than from the "cohort" life table. The former is based on a strong assumption of constant mortality in the population, whereas the latter calls for a recording of the mortality experience of a group of individuals, which is often an impossible task. Thus, a method of calculating cohort life expectancy without actual follow up is much needed. METHODS: Estimation of cohort life expectancy was based on an age-cohort model. Mortality data for the male population in Taiwan from 1951 to 1990 are used to illustrate the methodology. RESULTS: The increment of life expectancy over time in Taiwan is actually steeper than was previously thought using the current life table technique. CONCLUSIONS: The method is easy to implement and the data required are the usual age and period cross classified mortality data. It warrants further investigation.

Adolescent↗
PubMed1996

[The development of shrimp blood agar for testing the hemolysis of shrimp's haemocyte by bacteria].

A new plating medium, shrimp blood agar, was developed by using the haemolymph of shrimp plus 200 ppm rose bengal as the substrate. The colorless shrimp haemocytes were dyed by rose bengal to red. On the present agar, the hemolytic bacteria strain may show a clear zone surrounding the bacterial colony. The result on hemolysis of 45 bacteria representing 12 genera isolated from aquaculture environments against shrimp blood agar and sheep blood agar was also evaluated. There are 11 strains with different results. The study showed that, with the aim of screening the hemolytic bacteria to shrimp, shrimp blood agar might reveal a relatively quick and accurate results than that of sheep blood agar.

Agar↗
PubMed1996

Are prostaglandins major mediators in perennial allergic rhinitis?

Certain prostaglandins acting as inflammatory mediators have been implicated in the aetiology of perennial allergic rhinitis (PAR). Inhibition of prostaglandin synthesis in the nasal mucosa might therefore influence the symptoms associated with PAR. A randomised, doubleblind, placebo-controlled cross-over trial using 0.1% Diclofenac eye-drops has been conducted to investigate this hypothesis. Diclofenac, a non-steroidal anti-inflammatory drug (NSAID), reduces prostaglandin synthesis through the inhibition of the cyclo-oxygenase pathway. Twenty-five patients with significant PAR and positive skin tests to relevant perennial allergens were recruited and two drops of the given preparation were administered bilaterally q.d.s.. Thirteen patients completed the study. Nasal symptom score (itch, rhinorrhoea, sneezing, and blockage), smell test score, saccharin transit time, total nasal airflow resistance, and nasal inspiratory peak flow measurements were obtained at each of three study visits. No significant treatment effects were found. The daily nasal symptom score over the entire study period showed no significant variation. Adverse effects such as local invitation, dry nose or throat were rare. No untoward changes in haematological, biochemical profiles and urinalysis occurred. In conclusion, topical 0.1% Diclofenac eye-drops applied nasally have no significant effect on PAR. Prostaglandins alone may not play a major role in mediation of symptoms in this condition.

Administration, Intranasal↗
PubMed1995

Comparison between resectable gastric adenocarcinomas seropositive and seronegative for Helicobacter pylori.

The preoperative seropositivity of Helicobacter pylori was determined in 128 patients who had undergone gastrectomy for primary gastric adenocarcinoma during the past 5 years. The overall seroprevalence of H. pylori was 64 per cent. Gastric cancers positive for H. pylori were associated with tumours located in the lower third of the stomach which were of localized type (Borrmann I and II) (P < 0.05), but not with age, sex, blood type, tumour size, invasion depth, lymph node metastases, histological type, DNA ploidy or type of surgery. The cumulative 5-year survival curves after surgical resection were significantly better in patients who were positive for H. pylori. Multivariate analysis revealed that seropositivity for H. pylori was not an independent prognostic factor. Pathological tumour node metastasis staging was the only prognostic indicator. Better prognosis for those with H. pylori-seropositive gastric cancer may be attributed to the more advanced stage of H. pylori-seronegative gastric cancers. The potential role of H. pylori in gastric cancer carcinogenesis and its biological significance warrant further investigation.

Adenocarcinoma↗
PubMed1995

Diagnosis of gastric adenocarcinoma using a scoring system: combined assay of serological markers of Helicobacter pylori infection, pepsinogen I and gastrin.

This study was carried out to develop a scoring system for the diagnosis of gastric adenocarcinoma (GAC). A total of 686 subjects, 150 patients with GAC, 182 with gastric ulcer, 127 with duodenal ulcer, and 227 subjects with negative findings, were enrolled. Analysis of the likelihood ratio (LR) showed that patients with advanced age, ulcer in the stomach, low serum levels of pepsinogen I (PGI), low PGI x gastrin values, and low PGI/gastrin ratio were likely to have GAC. Of these indicators, the serum PGI level had the greatest weight, with a LR of 7.59 for the group with a level < 30 ng/ml. A scoring system combining serum PGI level, Helicobacter pylori seropositivity, and gastric ulcer status was derived, using a logistic regression model. This scoring system was found to be better than any one-parameter criterion for diagnosing GAC after evaluation by the area under the receiver operating characteristic curve (0.84; 95% confidence interval, 0.81-0.88) or by specificity-fixed sensitivity (sensitivity 0.82 at specificity 0.72, sensitivity 0.87 at specificity 0.66, sensitivity 0.96 at specificity 0.44). This scoring system may be potentially useful as a new model for the noninvasive diagnosis of GAC in the future.

Adenocarcinoma↗
PubMed1995

Hepatocellular carcinoma in a pregnant woman detected by routine screening of maternal alpha-fetoprotein.

A 26-year-old pregnant woman was diagnosed as having hepatocellular carcinoma at 16 weeks of gestation when extremely high levels of alpha-fetoprotein were found on a routine screening examination. The pregnancy was terminated, and a right hepatectomy was performed. Although such cases are rare, this one suggests that early measurement of maternal serum alpha-fetoprotein in a pregnant woman with hepatitis B surface antigenemia may allow the timely detection of a hepatocellular carcinoma.

Abortion, Induced↗
PubMed1995

Analysis of cancer rates using excess risk age-period-cohort models.

BACKGROUND: Recently the age-period-cohort (APC) model has become a popular epidemiological tool. However, it is well known that the model suffers from the identifiability problem. The simple multiplicative formulation of the model in terms of the age, period, and cohort variables without resorting to the underlying biology also casts doubt on the interpretability of the model parameters. METHODS: Excess risk APC models for cancers are developed based on carcinogenesis processes in human populations. These models have the beneficial feature of biological plausibility and do not suffer from the identifiability problem. Apart from the age, period, and cohort effects, a new kind of effect, the impact effect, is also introduced into the models. A computer program has been developed to fit the models which contain non-linear as well as restricted parameters. RESULTS: Two published mortality datasets are used to demonstrate the methodology. The proposed models fit better than the conventional APC model in both examples. CONCLUSIONS: Despite all the merits of the proposed models, several statistical issues should be investigated further before accepting this methodology as a general data-analytical tool.

Adult↗
PubMed1995

Clinicopathologic characteristics of Helicobacter pyloric seropositive gastric adenocarcinomas.

To compare and characterize retrospectively the clinicopathologic features of gastric cancers with and without previous Helicobacter pylori infection, we determined the preoperative seropositivity of H. pylori in 151 patients who had undergone gastric resection for primary gastric adenocarcinoma between 1988 and 1993. The overall seroprevalence of H. pylori was 60.9%. H. pylori-positive gastric cancers were frequently associated (p<0.05) with macroscopic localized types (Borrmann I and II) in which negative cancer associated with infiltrative types (Borrmann III and IV) and cancer invasion of the duodenum. Multivariate analysis showed that H. pylori seropositivity was not an independent prognostic factor. Pathologic tumor-node-metastases (TNM) stage remained the only prognostic indicator. Our study suggests that H. pylori has a significant impact on the clinically relevant tumor biology of gastric cancer. Investigation along this line is warranted.

Adenocarcinoma↗
PubMed1995

Necrosis of the colon as a complication of cardiac injury: case report.

Necrosis of the colon as a complication of cardiac injury is very rare. A 21-year-old young man was sent to the emergency room with shock status because of a stabbing wound penetrating into the heart. The patient survived after cardiopulmonary resuscitation, emergency sternotomy, and cardiac repair. Necrosis of the colon occurred 11 days after the accident.

Adult↗
PubMed1995

Dental erosion.

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Beverages↗
PubMed1995

Surgical treatment of gastric adenocarcinoma: the role of lymph node dissection.

In this retrospective study, 652 patients who had curative resections for gastric cancer from 1977 to 1991 were reviewed to evaluate improvements in gastric cancer surgery and the influence of the extent of lymphadenectomy on survival. The patients were grouped into three time periods: 1977 to 1981, 1982 to 1986 and 1987 to 1991. The percentage of patients with early gastric cancer increased from 17.7% during 1977 to 1981, to 24.3% during 1987 to 1991. The average number of dissected lymph nodes was 7.5 +/- 8.1 during 1977 to 1981 and 16.4 +/- 10.3 during 1987 to 1991, when more radical lymphadenectomy was adopted. Total gastrectomies increased from 10.9% to 25.9% in the same time periods while combined visceral resections increased from 26.7% to 38.1%. Operative mortality decreased from 5.0% to 1.7%. The overall 5-year survival rate increased from 34.8% to 59.4%. In subgroup analysis, significant improvement of the 5-year survival rate was noted in the following groups: patients with stage I, II and III tumors but not stage IV; both proximal and distally located tumors; tumors with or without lymph node metastases; T1 and T2 but not in T3 and T4 (cancer invasion beyond the serosa). The decreased surgical mortality in recent years suggests that curative resection with extensive lymph node dissection can now be safely performed. Radical gastrectomy with extended lymphadenectomy may be adopted in gastric cancer resection for better control of regional disease.

Adenocarcinoma↗
PubMed1994

Predisposition to renal carcinoma in the Eker rat is determined by germ-line mutation of the tuberous sclerosis 2 (TSC2) gene.

Genetic predisposition to neoplasia often involves tumor suppressor genes. One such model of hereditary renal carcinoma was described in the rat by Eker. These tumors share morphologic similarities with human renal cancer. Linkage analysis localized the inherited mutation to rat chromosome band 10q12. This region is syntenic with human chromosome band 16p13.3, the site of the tuberous sclerosis 2 (TSC2) gene. A specific rearrangement of the rat homologue of TSC2 was found to cosegregate with carriers of the predisposing mutation. Tumors with or without loss of heterozygosity expressed only the mutant allele, consistent with the two-hit hypothesis. This mutation gave rise to an aberrant transcript that deletes the 3' end normally containing a region of homology with the catalytic domain of rap1GAP.

Animals↗
PubMed1994

p16 alterations and deletion mapping of 9p21-p22 in malignant mesothelioma.

To determine whether p16 is altered in human malignant mesothelioma (MM), molecular analysis of multiple 9p loci was performed on 40 cell lines and 23 primary tumors from 42 MM patients. We identified homozygous deletions of p16 in 34 (85%) cell lines and a point mutation in 1 line. Down-regulation of p16 was observed in 4 of the remaining cell lines, 1 of which displayed a DNA rearrangement of p16. Homozygous deletions of p16 were identified in 5 of 23 (22%) primary tumors; no mutations or rearrangements were found in these specimens. Four cell lines displayed a single homozygous deletion proximal to or distal to p16; 4 others had 2 nonoverlapping deletions, one involving p16 and the other involving a region proximal to this locus. These data indicate that alterations of p16 are a common occurrence in MM cell lines and, to a lesser extent, in primary tumors. Furthermore, deletions of 9p21-p22 outside of the p16 locus may reflect the involvement of other putative tumor suppressor genes that could also contribute to the pathogenesis of some MMs.

Base Sequence↗
PubMed1994

A novel dioxabicyclo[3.3.1]nonane, a key intermediate in the synthesis of erythronolide B seco-acid.

In the title compound, (1R,4S,5R,6R,8R)-1-ethyl-4,6,8-trimethyl-2,9-dioxabicyclo[3.3.1]++ +nonan-6-yl 1-imidazolecarboxylate, C16H24N2O4, the 2,9-dioxabicyclo[3.3.1]nonane ring system assumes a double-chair conformation. Bond angles around the ring are enlarged compared to normal tetrahedral values to alleviate some of the overcrowding which results from close intramolecular H...H and C...C contacts. The N-imidazolylcarbonyloxy group is nearly planar with dihedral angles of 5.2 (2) and 6.0 (2) degrees between the imidazole and carbonyl groups for molecules 1 and 2, respectively.

Bridged Bicyclo Compounds↗
PubMed1994

Isolation of a new gene GS2 (DXS1283E) from a CpG island between STS and KAL1 on Xp22.3.

A gene, GS2 (DXS1283E), was isolated from a CpG island located approximately midway between the steroid sulfatase (STS) and the Kallmann syndrome (KAL1) loci on the distal short arm of the human X chromosome. DNA sequencing of a GS2 cDNA clone revealed an open reading frame for a basic protein of 253 amino acid residues. A polymorphic CT dinucleotide repeat was found in the 3' untranslated region. The GS2 gene is expressed in all human tissues examined, including heart, brain, placenta, lung, liver, muscle, kidney, pancreas, and spleen. Several GS2 transcripts, ranging in size from 1.1 to 5.8 kb, were found among different tissues, suggesting tissue-specific processing of the GS2 transcript. Characterization of GS2 genomic clones revealed that the gene consists of 7 exons spanning over 26 kb, with a CpG island located in the first intron. The GS2 gene is transcribed toward Xpter, in the same direction as KAL1 but opposite to that of STS.

Amino Acid Sequence↗