Biomedical subjects
Publications and source records attributed to S Y Yu.
We describe two cases of multiple lymphomatous polyposis in the gastrointestinal tract from the esophagus to the rectum. Clinical findings, histopathologic and immunohistochemical findings in paraffin embedded tissue are discussed. It is important to recognize this rare form of gastrointestinal lymphoma because of the prognostic and therapeutic implications.
Cerebrospinal fluid rhinorrhea is an uncommon but dangerous disease. Many lethal complications, such as bacterial meningitis and pneumoencephalus, may be the result of cerebrospinal fluid rhinorrhea. Otolaryngologist, neurosurgeons and radiologists must know how to diagnose, how to localize the site of leakage and how to choose the best method of treatment. A case of cerebrospinal fluid rhinorrhea and meningitis due to improper sinus surgery is presented. Satisfactory result, such as avoidance of unnecessary brain tissue damage, can be obtained by extracranial endonasal repairing of the fistula with a composite septal flap.
254 patients with cervical cancer were treated by radiotherapy from Jan 1979 to Dec 1984. All the patients were followed up at least for more than 3 years, of them 180 for over 5 years. According to various symptoms, picture of the tongue and pulse condition, the disease was classified into 4 types, namely: 1) deficiency of liver-yin and kidney-yin, 2) deficiency of splenic qi, 3) internal retention of damp-heat, and 4) stagnation of qi and blood or stagnation of liver qi. The survival rate of the various types was quite different. The patients of type 4 had the worst prognosis. The prognosis of patients with type 1 was significantly better than that of patients with type 4. The difference was of statistical significance (P less than 0.01).
The purpose of this study was to evaluate the effect of selenium (Se) in the prevention of human primary liver cancer. Three intervention trials were conducted among the residents at high risk to primary liver cancer (PLC) in Qidong county, Jiang-su province, the People's Republic of China. This area has the second highest rate of PLC in China. One trial was undertaken among the general population in a township with supplement of table salt fortified with 15 ppm anhydrous sodium selenite (Se-salt) for 5 y and the other four townships with similar PLC incidence rate served as the controls using normal table salt. The second trial was undertaken among hepatitis B virus surface antigen carriers (HBVsAg+) receiving supplement of 200 micrograms Se in form of selenized yeast (Se-yeast) daily vs placebo for 4 y. The third trial was carried out in members of families with high PLC incidence using Se-yeast (200 micrograms of Se daily) vs placebo for 2 y. The results showed that nutritional supplement of Se could reduce the PLC incidence significantly.
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We report findings that demonstrate for the first time that the structure of the elastic fibers of the uterus and cervix are characteristic to these tissues. Elastic fibers of the uterine corpus and cervix were studied by scanning electron microscopy (SEM). Elastic tissues were prepared from non-pregnant human uteri and pregnant rat uteri by three different methods: extraction from the tissue homogenates, in situ digestion by autoclaving of sliced tissue, and in situ formic acid digestion of sliced tissue. In addition, in situ formic acid digestion of the glutaraldehyde-fixed uterine wall of pregnant rats was done. Under SEM, the uterine elastic fibers revealed two distinct structures--fibrils and thin sheets of elastic membranes. Isolated fibers and membranes ranged in thickness from 0.1 to 0.4 micron which is thinner than aortic elastic lamellae (1-2.5 microns in thickness). These thin sheets of elastic membranes and elastic fibrils probably allow the uterus to maintain its elasticity without exerting excess pressure on the growing fetus. Formic acid digestion of fixed uterine walls of pregnant rats preserved the structural organization of elastic tissues near in vivo conditions. In these tissues, the fibers were arranged in a honeycomb structure made up largely of membranes, although sparse fibrils were present. These elastic, membranous sheets were arranged parallel to the plane of the uterine surface and interconnected with the threads of the membranes or fibrils. In the rat uterine wall, at least 12 parallel layers of elastic sheets were present. In contrast, at low magnification, the elastic tissues in the non-pregnant human uterus had no specific architectural arrangement and exhibited a sponge-like structure. Elastic fibers of the cervix were also made up of membranes and fibrils, and these fibers were organized into fishnet-like structures. These cervical membranes had fenestrations and pits with a diameter of 3-5 microns. In these studies, the concentrations of insoluble elastin in human uteri were found to be 1.38 and 1.32-1.41% of dry-defatted tissues for uterine body and cervix, respectively. The concentrations of total collagen were 38.8 and 64.3-72.4% of dry-defatted tissues for uterine body and cervix, respectively.
Ames Salmonella assay and sister chromatid exchanges in CHO cells were used to study the mutagenic activity of size-fractionated air particles from outdoor air in Beijing, Taiyuan, Wuhan, Shenyang and the areas with high incidence of lung cancer in Xuanwei county. Five size particles were collected from each sampling points. The results indicate that: 1. The results of organic matter content in particles. 2. All of the samples have mutagenicity. There was negative correlation between mutagenicity and particle sizes, mutagenicity was increased with particle size reduced. The maximum mutagenicity was at the particle size less than 1.1 microns. So it is especially hazardous to human health. There was logarithmic correlation between organic matter content and revertants. Correlation coefficient was 0.98. Regression equation was gamma = 0.23 + 1.01 X. 3. The results showed that of the five sampling points air pollution at the high lung cancer incidence area of Xuanwei county was the most severe.
This pilot study evaluated the feasibility and effectiveness of conducting a double-blind clinical trial for the prevention of lung cancer with selenium (Se) in Yunnan Tin Corporation, the People's Republic of China, where the incidence rates of lung cancer are extraordinarily high among the miners. Forty healthy miners were randomized to either 300 micrograms of Se in high Se malt cakes or an identical placebo of malt cakes daily for one year. Subjects consumed their usual daily diet. The low Se concentrations in plasma (0.05 +/- 0.008 microgram/mL) and hair (0.442 +/- 0.085 microgram/g) reflected their low dietary Se intake in the control subjects. In Se-supplemented group, the Se status was increased by 178% for serum and 194.8% for hair. The serum GSHpx activity was increased by 155.7%, whereas the lipid peroxide level was reduced by 74.5% compared to the placebo. The results of UDS assay indicated that the lymphocyte DNA damage induced by ultraviolet irradiation and carcinogen 3,4-benzpyrene could be protected by Se supplementation. Se-supplementation did not affect the liver function test (SGPT), as well as the concentrations of hemoglobin, albumin, and cholesterol. Thus, daily intake of 300 micrograms Se in form of Se-malt as a chemopreventive measure is safe and effective to humans with low Se status.
We studied lung structure and function in Fischer-344 and Sprague Dawley rats to compare the pathophysiologic features of the aged lung in animal strains. Both strains were maintained under identical conditions of minimal exposure to injurious environmental agents. We measured the number, size, and surface area of alveoli, pressure-volume characteristics and connective tissue content of lungs at midlife (12 or 14 months of age) and old age (24 months of age). Results showed differences in the older versus younger group of the Sprague Dawley strain as indicated by enlarged air spaces [154 +/- 21 (SEM) versus 118 +/- 13 micromicroliter] (p less than 0.05), increased collagen (hydroxyproline content 4.1 +/- 0.1 versus 3.0 +/- 0.1 mg/lung) (p less than 0.05), and a leftward shifted pressure-volume curve. There was no change in surface area or alveolar number. The structural lesions are consistent with air space enlargement with fibrosis and not emphysema. In contrast, no major changes were found in the lungs with age in Fischer-344 rats. We hypothesize that in the Sprague Dawley strain the aging process impairs the ability of the lung to maintain normal structure and function. Two strains of rats which differ pathologically in old age may be useful in the study of the effects of aging on the lung.
We evaluated the processes controlling the accumulation of collagen and elastin in main pulmonary arteries of rats during an episode of hypoxic pulmonary hypertension. Explant cultures of main pulmonary arteries were incubated with [3H]proline to measure collagen and protein synthesis and percent collagen synthesis. Elastin synthesis was measured by [14C]valine incorporation into insoluble elastin. Relative collagen synthesis increased twofold (from 1.1 +/- 0.2 x 10(3) to 2.0 +/- 1.0 x 10(3) disintegrations per minute [14C]hydroxyproline/vessel/hr/mg protein), relative collagen synthesis doubled (from 2% to 4-5% of total protein synthesis), and elastin synthesis increased ninefold (from 0.4 +/- 0.2 x 10(4) to 3.6 +/- 0.6 x 10(4) dpm [14C]valine/vessel/hr/mg protein) in early hypertension. The level of pro alpha l(I) collagen RNA paralleled the relative collagen synthetic rate during the study period. Within 7 days of recovery from hypoxia, collagen and elastin contents were normal. We conclude that collagen and elastin in main pulmonary arteries are synthesized rapidly during an episode of hypoxic pulmonary hypertension and that collagen and elastin are rapidly removed from the hypertensive vessel during normoxic recovery.
White Carneau pigeons have previously been shown to be genetically susceptible to the development of spontaneous atherogenesis. The severity of development of atheromatous lesions is considerably greater than a more resistant breed of Show Racer pigeons. Analysis of levels of total hydroxyproline and isodesmosine in the thoracic aorta and celiac bifurcation of prelesion, six-week-old White Carneau and Show Racer pigeons, revealed an increased accumulation of total collagen and cross-linked elastin in the White Carneau arterial tissue. Using dot blot hybridization, measurements of steady state levels of several mRNAs in total RNA extracted from pigeon aortic tissue were also determined. While the increased deposition of extracellular matrix proteins was paralleled by a significantly greater recovery of mRNAs coding for pro alpha 1(1) collagen and elastin, in RNA extracted from White Carneau aortal tissue, increased recovery of mRNAs coding for an intracellular protein, gamma-actin were also observed in White Carneau aortal tissue. No differences in steady state levels of mRNAs coding for pro alpha 1(1) collagen and elastin were observed in RNA extracted from pigeon liver, suggesting a tissue specific increase in the mRNAs coding for these connective tissue proteins in aorta. A markedly reduced cell population however, was responsible for this overall increase in biosynthetic activity in White Carneau pigeon aortic tissue. This was demonstrated by a reduced cell count and by the recovery of reduced levels of total DNA in the thoracic aorta and celiac bifurcation of the White Carneau pigeon. The cell population in White Carneau aortic tissue exhibits therefore a markedly different phenotype with respect to a capacity for the biosynthesis of extracellular and intracellular proteins.
We reported the purification and characterization of a pancreatic cancer-associated antigen from normal colonic mucosa (PCAAc) and pancreas-specific antigen (PaA) according to Kitada's and Loor's methods as well as the established method of double antibody enzyme-linked immunoassay for the detection of serum PaA and PCAAc; respectively. In our study, 155 serum samples were detected (including normal controls 40; pancreatic cancer 31; other malignant disease 56 and benign diseases 28). The results indicated that the overall sensitivity and specificity of a single PCAAc test for pancreatic cancer were calculated to be 70.98% and 96.43%; a single PaA to be 80.65% and 95.23%, respectively. Furthermore, the sensitivity and specificity of combined tests (PCAAc and/or PaA) for pancreatic cancer were calculated to be 96.77% and 90.91%. The diagnostic efficiency was 90.91%. None of 84 cases of nonpancreatic cancer and benign diseases has been found elevated PCAAc and PaA simultaneously. The results suggest that simultaneous detection of PCAAc and PaA would have increased the sensitivity of diagnosis for pancreatic cancer.
We studied the effect of low-protein diet (8% casein) on lung growth in rats from 3 to 7 weeks of age. Their diet was isocaloric with that of control animals fed a diet of 20% casein. The calorie intake of experimental animals was increased during the first 3 weeks of the experiment, but they increased less (about 10%) in body weight, had less protein and less water when the whole body was examined, and had lower serum proteins and decreased urinary hydroxyproline. The experimental animals remained in positive nitrogen balance by maintaining low urinary nitrogen excretion. The lungs of the experimental animals were abnormal, with decreased absolute amounts of hydroxyproline and desmosine and of these relative to unit lung weight. The lungs contained more air per gram of lung tissue, and the volume of air in the lung was increased at all transpulmonary pressures above zero. When corrected for increased total lung capacity, there was a loss of recoil at mid-lung volumes. Saline-filled volume-pressure curves, corrected for lung volume, showed similar loss of recoil. Alveolar multiplication was quantitatively normal, but the experimental animals had larger alveoli. We conclude that the protein deprivation in isocalorically fed animals has a specific effect on lung scleroprotein content, which may be due to diminished synthesis, and this results in both structural and functional abnormalities in the lung. Our results indicate the importance of dietary protein in lung development and possibly as one of the causes of emphysema. Further studies are needed to know whether this would be a problem in infants of Kwashiokor.
Serum ribonuclease (RNase) activity and its isoenzymes were determined by biochemical and PAGE electrophoretic separation technique in 20 patients with pancreatic cancer, in 27 with other gastroenterologic malignant tumors, 8 with acute pancreatitis, 7 with chronic pancreatitis, 5 with leukemia, 3 with chronic uremia of glomerulonephritis, and in 30 adult normal controls. Serum A1AT rocket immunoelectrophoresis and carcinoembryonic antigen (CEA) radioimmunoassay were also carried out simultaneously.
NBT-PABA test was performed in 72 subjects with simultaneous determination of the plasma PABA time-concentration curve. The curve in 25 controls after oral administration of N-benzoyl-L-tyrosyl-P-aminobenzoic acid (NBT-PABA) peaked (3.88 +/- 0.78 micrograms/ml, M +/- SD) at the third hour. In patients with chronic pancreatitis (24) and pancreatic carcinoma (6), the curves were flattened, and peaked at the fifth hour (2.7 +/- 1.4 micrograms/ml, M +/- SD), and fourth hour (3.14 +/- 2.26 micrograms/ml, M +/- SD), respectively. The discrimination between the controls and patients with chronic pancreatitis was most significant in the third-hour plasma PABA concentration (P less than 0.0001). This study shows that determination of the third-hour plasma PABA concentration is better in sensitivity and specificity than the 6-hour urinary excretion of PABA, suggesting that the third-hour plasma PABA concentration after oral administration of NBT-PABA might be a sensitive index of exocrine pancreatic function test.
We set up a software system which can store, retrieve and handle the data for cervical cancer. The data of 526 patients with cervical cancer have been stored. The correlation between various prognostic factors and 5-year survival was studied by means of stepwise analysis. It was found that such factors as macroscopic type of tumor, hemoglobin, peritumoral lymphocytic infiltration and age of the patients influenced prognosis significantly. The best regression equation to predict the 5-year survival of patients was established by this method. It was proved that the calculated survival rate in correspondence with the real 5-year survival rate was 83.6%-99.55%. This study was important to us. We could then take appropriate therapeutic measures in the treatment of patients with cervical cancer.
The purpose of this study was to define the clinical features of acute myocardial infarction in a group of elderly Chinese. The presenting symptoms, complications and mortality of acute myocardial infarction were compared in 631 patients (430 men and 201 women) aged 60 and over and 389 patients (333 men and 56 women) whose ages were under 60 years. The incidence of painless myocardial infarction was 17.6% in the elderly versus 5.9% in the younger group. Typical chest pain was present in 63.1% of the elderly and 84.3% of the younger Chinese. However, the incidence of other nonspecific presenting symptoms was higher in the elderly group. Likewise, the major complications in the elderly group were more severe than those in the younger group. For example, the incidences of cardiogenic shock, heart failure, arrhythmia, pulmonary infection and cardiac rupture in the older group were 19.8, 24.2, 77.2, 22.0 and 4.4%, versus 15.1, 19.5, 48.1, 9.5 and 1.1% in the younger group, respectively. The immediate (4 week) mortality rate of the older group was 21.9% (over 80 years 51.5%), but was only 11.0% in the younger group. Although the incidences of hypertension and pulmonary disease were significantly greater in the elderly group, these diseases alone did not account for the higher mortality rate in the elderly.
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