Search PubMed⌕ Search

Biomedical subjects

M S Chen

Publications and source records attributed to M S Chen.

At least 127 records · Page 7Linked to original sources
PubMed1990

Microalbuminuria and diabetic complications in Chinese non-insulin-dependent diabetic patients: a prospective study.

Urinary albumin excretion rate (AER) was monitored for periods of up to 3 years and 8 months with an ELISA method in 63 non-insulin-dependent diabetic Chinese subjects and was compared with 50 normal subjects. AER was 3.15 +/- 0.25 micrograms/min (M +/- SE) with a range of 0.27-8.40 micrograms/min for the normal subjects and 7.11 +/- 0.50 (2.11-19.45) micrograms/min for the diabetic subjects. The latter had significantly higher AER (P less than 0.0005). Age, sex, duration of diabetes, HbA1c and BMI did not correlate with AER in the diabetics. The presence of hypertension was found to be accompanied by an accelerated elevation of AER (5.96 +/- 1.58 vs 10.16 +/- 2.17 micrograms/min, at the beginning and at the end of the observation, respectively). Once hypertension became evident, control of blood pressure to a level comparable to that of the non-hypertensive group was not sufficient to halt the deterioration of urinary albumin excretion.

Age Factors↗
PubMed1990

Prognostic factors of nasopharyngeal carcinoma: a multivariate analysis.

Between 1979 and 1985, 561 patients with nasopharyngeal carcinoma were reviewed to determine prognostic factors that may influence survival. Sex (p = 0.294) and histopathology (p = 0.677) had no correlation to the actuarial survival, whereas the site of cervical metastasis (p = 0.001) and the radiation doses to the nasopharynx and regional lymph nodes (p = 0.03) were both significant when one used univariate analyses. Cox's multivariate regression model revealed that the presence rather than the site of distant metastases was the single most important independent factor influencing the treatment outcome (p less than 0.0001). The addition of chemotherapy, on the other hand, did not show a survival benefit even when one took available confounding factors into account. There are, however, survival advantages associated with: (a) young age (less than or equal to 40 years), (b) asymptomatic status, (c) Stage I or II lesions, and (d) biopsy via nasopharynx instead of neck nodes. These favorable prognostic factors may be used for therapeutic guidance and end-result reporting.

Adolescent↗
PubMed1990

Evaluating the impact of P.L. 99-252 on decreasing smokeless tobacco use.

Literally, Public Law 99-252 (otherwise known as the Comprehensive Smokeless Tobacco Health Education Act of 1986) includes provisions that are informational in nature. Implicitly, however, this law is considered part of the federal effort in disease prevention and health promotion. This paper reviews the societal and legislative context of that act and presents a plan to evaluate the impact of this law on decreasing smokeless tobacco use. The uniqueness of this plan is its incorporation of nine disciplinary perspectives in the derivation of indicators to measure process, impact, and outcome measures for decreasing smokeless tobacco use. A basic prevention strategy is suggested by this interdisciplinary approach. In addition, specific lessons could be applied from the history of successes in public health to decreasing smokeless tobacco use.

Adolescent↗
PubMed1990

An epilogue to evaluating the impact of P.L. 99-252 on decreasing smokeless tobacco use.

In a previous paper, "Evaluating the Impact of P.L. 99-252 on Decreasing Smokeless Tobacco Use," the context of this law and the theoretical framework for an evaluation plan for measuring its impact were described. In this paper, the methodology and selected findings from this project as well as their implications are discussed. This discussion includes the identification of the six indicators considered to be the most relevant, valid, reliable, accessible, and practical for measuring the impact of this law on decreasing smokeless tobacco use, as well as a report on the feasibility analysis of three of these indicators. Pilot data on two indicators--pounds of smokeless tobacco sold and incidence rates of tobacco-induced leukoplakia--are presented and analyzed.

Adult↗
PubMed1990

A comparison of newly and previously diagnosed diabetics in Taiwan.

Between 1985 and 1986, during a population survey of diabetes in 1 urban and 5 rural areas of Taiwan, a total of 11,478 adults aged 40 or older were screened. Capillary whole blood glucose was determined with a glucometer (Ames Co.) The diabetic criteria followed the WHO designations. From this survey, a comparison of 225 newly diagnosed and 383 previously diagnosed diabetics was conducted. Multiple regression analysis revealed a highly significant correlation for all diabetics with regard to age, body mass index, family history and hypertension, but no specific correlation to habitat. Mean fasting glucose levels in previously and newly diagnosed diabetics were 172 and 158 (males 158 vs 147 and females 184 vs 165) mg/dl, respectively, which suggest that treatment is apparently inadequate in this population. The prevalent rate (%) of retinopathy for previously and newly diagnosed diabetics was 45.2 and 28.3 (males 42.8 vs 33.3 and females 47.5 vs 24.8), respectively. The prevalence is as common as those reported in western countries. In conclusion, previously diagnosed diabetics had higher fasting glucose concentrations and prevalent rates of retinopathy than newly diagnosed diabetics, and these findings were particularly prominent in females.

Adult↗
PubMed1990

[Behcet's disease with ocular involvement in Taiwan: a joint survey of six major ophthalmological departments].

A total of 103 cases with ocular involvement of Behcet's disease, seen over a period of 19 years (1970 to 1988), were collected from the ophthalmological departments of 6 major medical centers in Taiwan. The yearly number of patients who first visited these hospitals from 1979 through 1983 was about 5 cases and about 14 cases from 1984 to 1988. The domiciles of the patients were most commonly (51.5%) in Northern Taiwan. All 103 patients were Chinese, of which 78 (75.7%) were men and 25 (24.3%) were women; the male to female ratio was 3.1. Extraocular symptoms of Behçet's disease, major or minor, and their frequencies among these patients included; oral ulcers, 97.1%, skin lesions, 74.8%; genital ulcers, 61.2%; arthritis, 47.6%; gastrointestinal lesions, 14.6%; epididymitis, 5.8%; central nervous system lesions, 2.9%; vascular lesions, 1.9%; pulmonary lesions, 2.9% and urinary lesions, 4.9%. Fifty-one (49.5%) patients were of the complete type and 52 (50.5%) of the incomplete type. The peak distribution of ages at the onset of the ocular lesions, was from 20 to 40 years. As for visual prognosis, 37.9% of the 198 diseases eyes had a visual acuity of 0.5 or better, 9.1% between 0.5 and 0.1, 25.3% between 0.1 and 0.01 and 27.8% were 0.01 or worse. In 24 (12.1%) eyes, the vision was completely lost. In HLA studies, a significantly increased incidence of HLA-A26 (p less than 0.01) and HLA-B51 (p less than 0.001) was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

A comparison of diabetic control status between urban and rural diabetic patients in Taiwan.

Between 1985 and 1987, in two urban and five rural areas in Taiwan, a total of 16,636 subjects aged 40 or over were screened for diabetes mellitus according to the WHO criteria. Four hundred and fifty-two previously diagnosed patients and 274 newly diagnosed patients were found. All were non-insulin-dependent diabetics. The blood glucose control status was compared between the urban and rural previously diagnosed diabetics. Those living in the rural areas were found to have better control with a higher percentage under regular treatment. Stepwise multiple regression failed to discover a significant correlation between control status and any of the following factors: sex, age, body mass index (BMI), diabetic duration, treatment regularity, exercise, occupation, education, family income and the presence of hypertension or large vessel diseases. About 30% of the patients in rural areas and 40% in urban areas were poorly controlled. This indicates that our diabetic control program should be strengthened.

Aged↗
PubMed1990

Gene rearrangement of cutaneous T-cell lymphoma.

Gene Rearrangement is considered to be a helpful tool for diagnosis of cutaneous T-cell lymphoma. In this study five patients with clinical diagnosis of cutaneous T-cell lymphoma were reviewed for their clinical presentation, skin biopsies and surface marker phenotypes. Southern blot analysis of DNA extracted from their skins revealed that rearrangement of T-cell receptor beta chain (TCRB) genes happened in three patients but rearrangement of immunoglobulin heavy chain genes was absent. TCRB rearrangement could also detect lymphoma involvement of lymph nodes, peripheral blood and bone marrow in our patients. In these conditions, systemic therapy is suggested.

Adult↗
PubMed1989

Identification of the carboxyl-terminal amino acids important for the ADP-ribosylation activity of Pseudomonas exotoxin A.

The ADP-ribosylation domain of Pseudomonas exotoxin A (PE) has been identified to reside in structural domain III (residues 405-613) and a portion of domain Ib (residues 385-404) of the molecule (Hwang, J., FitzGerald, D. J., Adhya, S., and Pastan, I. (1987) Cell 48, 129-136). To further determine the carboxyl end region essential for ADP-ribosylation activity, we constructed sequential deletions at the carboxyl-terminal of PE. Our results show that a clone with a deletion of the carboxyl-terminal amino acid residues from Arg-609 to Lys-613 and replaced with Arg-Asn retained wild-type PE ADP-ribosylation activity. Deletion of the terminal amino acid residues from Ala-596 to Lys-613 and replaced with Val-Ile-Asn reduced ADP-ribosylation activity by 75%, while deletions of 36 or more amino acids from the carboxyl terminus completely lose their ADP-ribosylation activity. These modified PEs were also examined for their ability to block PE cytotoxicity. Our results shown that modified PEs which lost their ADP-ribosylation activity correspondingly lost their cytotoxicity. Furthermore, extracts containing PE fragments without ADP-ribosylation activity were able to block the cytotoxic activity of intact PE. Our results thus indicate that carboxyl-terminal amino acids in the Ser-595 region are crucial for ADP-ribosylation activity and, consequently, cytotoxicity of PE. The modified PEs which have lost their ADP-ribosylation activity may also be a route to new PE vaccines.

ADP Ribose Transferases↗
PubMed1989

Cytogenetic evidence of multifocal origin of a unilateral retinoblastoma. A help in genetic counseling.

Retinoblastoma (Rb) occurs in two different genetic forms, hereditary and nonhereditary. Patients with nonhereditary Rb have unilateral, unifocal tumors, and those with the hereditary form usually have bilateral, multiple tumors. However, about 15% of patients with unilateral disease actually have multifocal tumors due to the hereditary form of Rb. Distinction between unilateral hereditary and sporadic Rb is very important both to the patient, who is at risk of later development of other malignancies, and to any future siblings and offspring. With only clinical data, the discrimination may be difficult. The cytogenetic detection of multiple unrelated clones in the tumor is very helpful for differential diagnosis because this finding strongly suggests the presence of a prezygotic germ cell mutation, which is heritable. A 23-month-old Chinese boy was found to have a single retinoblastoma at the right eye. Cytogenetic study of the tumor cells revealed three abnormal clones. Two of them were related, but the third one had completely different markers, suggesting a hereditary, multifocal origin of the tumor. None of the three clones showed an abnormality of 13q, which is present in about 21% of all Rb patients.

Chromosome Banding↗
PubMed1989

Phorbol ester transiently increases topoisomerase I mRNA levels in human skin fibroblasts.

Exposure of human skin fibroblasts to phorbol 12-myristate 13-acetate (PMA) results in a transient increase in the level of topoisomerase I mRNA. A maximal increase (about 10-fold) in the level of topoisomerase I mRNA was observed 3 h after adding 200 nM PMA, but a decrease to the basal level was observed within 12 h of PMA treatment. The lowest PMA concentration to give an observable induction of topoisomerase I gene expression was found to be 20 nM. In addition, the induction of topoisomerase I gene expression by 20 nM PMA pulse treatment for 10 min followed by incubation for an additional 3 h attained the same level of induction seen with 3 h of continuous exposure to 20 nM PMA. This observation suggests that once the signal for protein kinase C activation is transduced, continuous exposure to PMA is not necessary for the maximal effect. To gain insight into the mechanism by which PMA stimulates topoisomerase I gene expression, cells were treated with PMA, cycloheximide, and actinomycin D, either alone or in various combinations. The results show that actinomycin D, but not cycloheximide, specifically abolishes the stimulatory effect of PMA, suggesting that PMA affects topoisomerase I gene expression at the transcriptional level.

Binding, Competitive↗
PubMed1989

Structure and function relationship of Pseudomonas exotoxin A. An immunochemical study.

We have raised antisera against Pseudomonas exotoxin A (PE) and domains Ia and III to study the structure-function relationships of PE. Anti-PE antibody (AbPE) was shown to abolish the ADP-ribosylation activity of PE. However, neither antidomain Ia antibody nor antidomain III antibody inhibited the ADP-ribosylation activity of PE. This suggests that the inhibition of ADP-ribosylation by AbPE results from the binding of AbPE to the region between domains Ia and III. Since the binding of AbPE to PE did not inhibit NAD hydrolysis in the absence of elongation factor 2, the inhibitory effect of AbPE on ADP-ribosylation may be due to steric hindrance rather than a direct action on the catalytic function. Thus, the interface between domain Ia and III may be the site of entry of elongation factor 2 during ADP-ribosylation. The antibodies were also used to study both the inhibitory effects of PE on protein synthesis and its cytotoxic activity. Either AbPE or antidomain Ia antibody, but not antidomain III antibody, was able to reverse the inhibition of protein synthesis by PE and to block its cytotoxicity. In addition, rabbits immunized with domain Ia acquired tolerance against 100 micrograms of PE injected subcutaneously. These results suggest that domain Ia is the cell-binding domain of PE and may be used for vaccination against PE-mediated diseases.

ADP Ribose Transferases↗
PubMed1989

Changing college students' lifestyles in favor of cancer prevention: a case study.

This article describes a case study in the examination of cancer risk reduction behavioral strategies chosen by 272 college students enrolled in the 1987 "How to Avoid Dying from Cancer ... Now and Later" course. The four most commonly selected cancers chosen by these students--breast, colon/colorectal, skin, and lung cancer--and the corresponding self-reported success of the various strategies are reported. The three most successful strategies were breast self-examination, use of sunscreen lotions, and increased awareness of breast cancer. We concluded that the potential of using behavioral self-contracts to induce lifestyle change in favor of cancer prevention is both cost-effective and practical.

Adult↗
PubMed1989

Family member cancer prevalence reported by university students taking a cancer prevention course.

Genealogical health histories were studied to determine the prevalence of family cancer in students taking an Ohio State University (OSU) cancer prevention/education class. One hundred twenty students enrolled in the spring 1987 Health Education class, "How to Avoid Dying from Cancer . . . Now and Later" reported a positive family cancer history. Survey forms indicating a cancer history were selected for use in this study. Cancer incidence and total cancer deaths were calculated for male and female populations. Male cancer incidence reported for fathers was 12%, paternal grandfathers 27%, and maternal grandfathers 25%. Female cancer incidence rates were lower than those reported in the male population. Cancer occurrences include 16%, 11%, and 21%, for mother, paternal grandmother, and maternal grandmother, respectively. In the study population, male (33%) and female (28%) cancer mortalities were reported as the leading cause of death. Frequent occurrences of skin and gastrointestinal cancer in males and breast cancer in females were noted. Family experiences with cancer are believed to stimulate student enrollment in OSU's cancer prevention program. Class promotion and design will be restructured to reflect the significance of a family cancer history. We believe this will provide a more effective means of generating the student's motivation to adopt cancer prevention activities.

Adult↗
PubMed1989

Clinical significance of cranial nerve deficit in the therapy of nasopharyngeal carcinoma.

The results of radiation treatment of nasopharyngeal carcinoma (NPC) have recently been improved, but the prognosis remains relatively poor in cases with cranial nerve (CN) involvement. A total of 109 cases with histologically-proven NPC and cranial nerve involvement treated during 1979-1985 were reviewed and analysed. Definitive radiotherapy (RT) was given to patients with a high upper margin of the RT field at 2.5 cm above the base of the skull to a total dose of 70.2 Gy/39 fractions/8 weeks, with two applications of intranasopharyngeal brachytherapy. There were 37 cases (34%) in Group I (upward invasion only) and 72 cases (66%) in Group II (bidirectional invasion). Abducens, trigeminal, oculomotor and facial were the commonly involved nerves. Headache was the major symptom at diagnosis and was present in 82.6% of the patients, significantly higher than in general NPC cases (p less than 0.005). Fifty per cent (31/62) achieved complete response to definitive RT, but it did not correlate well with survival rate. The residual neurological deficit of each CN ranged from 31 to 57%. The actuarial 5-year survival rates of Groups I and II were similar in spite of neck lymph node metastasis in Group II (33% (I) compared with 24% (II); p greater than 0.05). Cases with single CN deficit did not show better results than those with multiple CN involvements. Five-year survivors were seen only in those who received a complete course of definitive RT.

Adult↗
PubMed1989

Polymorphic reticulosis: a malignant lymphoma of B-cell lineage.

Whether the pathogenesis of polymorphic reticulosis is from T cells, B cells, or histiocytes has been controversial. In this study, the Southern blot hybridization technique was used to analyze immunoglobulin and T-cell receptor beta-chain genes and to perform the conventional surface marker analysis in two patients with polymorphic reticulosis. The immunophenotype demonstrated the presence of predominantly mature, activated T-lymphocytes, minimal B-cells, and no natural killer cells or monocytes/granulocytes. The mature T-cell phenotype could be due to either inflammatory infiltrates or neoplastic cells of peripheral T-cell type, because the two coexist in polymorphic reticulosis tumors. The value of surface marker examination is limited in the analysis of PMR tumors. However, genetic analysis revealed that only Ig genes were rearranged, with no rearrangement of the TCR beta gene. Rearrangement of immunoglobulin genes occurs in B-lineage lymphoid neoplasms and is thought to be a criterion for diagnosis of lymphoid neoplasms. Based on genetic analysis and clinicopathologic information, this study concluded that polymorphic reticulosis is a malignant lymphoma of B-cell lineage.

Adult↗
PubMed1989

Prospective hormone study of hypothalamic-pituitary function in patients with nasopharyngeal carcinoma after high dose irradiation.

With the aim of evaluating the effect of high dose irradiation (6,500 cGy/36 fractions or higher) to pituitary fossa, a prospective study was carried out in patients with nasopharyngeal cancer by a serial determination of several hormones in the serum, before and after the course of radiation therapy (RT). The radiation treatment field was at least 1 cm above the skull base with bilateral parallel opposing fields. Hormone assays were performed three times on each patient: (1) prior to, (2) one month after, (3) 15-18 months after radiation therapy. The study included determination of serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroid-stimulating hormone (TSH), cortisol, growth hormone (GH) and prolactin concentrations and LH-releasing hormone, thyrotrophin-releasing hormone stimulation and insulin tolerance tests were also carried out. Complete profiles were obtained in 24 patients (16 males and 8 females), aged 16-67 years. The results showed a significant decrease in the level of serum peak value of LH in males 18 months after therapy, and also in GH both one month and 18 months after therapy. A significant increase in the peak value of serum TSH observed after therapy. Decreased serum FSH, cortisol and prolactin levels were noted, but these did not reach statistical significance. The decrease in GH level appeared earlier and was more sensitive than that found for the other hormones, and could prove to be a useful parameter for clinical evaluation. None of the patients showed any clinically recognizable symptoms or signs of hormone deficiency in the 18-33 months following completion of the radiation therapy.

Adolescent↗