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C L Yen

Publications and source records attributed to C L Yen.

10 recordsLinked to original sources
PubMed1999

Choline deficiency-induced apoptosis in PC12 cells is associated with diminished membrane phosphatidylcholine and sphingomyelin, accumulation of ceramide and diacylglycerol, and activation of a caspase.

It is not well appreciated that nutritional status can modulate apoptosis, a process that eliminates unwanted or damaged cells. Choline is an essential nutrient, and its absence induces apoptosis. When PC12 cells were cultivated in a choline-free medium, apoptosis was induced (27.4% of cells apoptotic at 72 h as compared to 4.4% in control medium). In choline-free medium at 72 h, there was a 49% decrease in phosphatidylcholine concentration (P<0.01) and a 34% decrease in sphingomyelin concentration (P<0.01); however, there was no change in phosphatidylethanolamine concentration. Before detecting increased apoptosis in choline-deficient cells, we measured a significant increase in ceramide (218% control) and diacyglycerol (155% control) concentrations. The addition of a cell-permeable ceramide to cells in control medium induced apoptosis; however, adding a cell-permeable diacyglycerol did not induce apoptosis. Caspase is a common mediator of apoptosis, and choline deficiency-induced apoptosis was prevented completely by replacing choline or adding a caspase inhibitor into the medium within 48 h of initial choline deprivation. In those cells rescued by replacing choline at 36 h, the concentrations of phosphatidylcholine, sphingomyelin, ceramide, and diacyglycerol returned to levels of control cells. In those cells rescued by adding a caspase inhibitor at 36 h, the concentrations of sphingomyelin and ceramide returned to control levels, but the concentrations of phosphatidylcholine and diacyglycerol did not return to normal. We propose that availability of dietary factors (choline in this model) can modulate apoptosis. Mechanisms that we identify using this model may help us to explain why dietary choline influences brain development.

Amino Acid Chloromethyl Ketones↗
PubMed1998

Management of lactose maldigestion by consuming milk containing lactobacilli.

The influence of nonfermented milk containing L. acidophilus or L. bulgaricus on lactose utilization by lactose maldigesters was investigated. Nonfermented milks containing L. acidophilus or L. bulgaricus at 10(8) and 10(9) CFU/ml were prepared using 2% low-fat milk. Lactose maldigestion was monitored by measuring breath hydrogen at hourly intervals for 8 hr following consumption of 400 ml of each diet. Nonfermented milk containing L. acidophilus B at 10(8) CFU/ml were not effective in reducing breath hydrogen and symptoms. Nonfermented milk containing L. acidophilus B at 10(9) CFU/ml only slightly decreased breath hydrogen production; however, the symptoms were significantly improved. Nonfermented milks containing L. bulgaricus 449 at 10(8) and 10(9) CFU/ml were effective in reducing breath hydrogen and symptoms. The results for bulgaricus milk were all significant. In this study, L. acidophilus B and L. bulgaricus 449 were chosen because of their similar beta-galactosidase activity and bile sensitivity. L. acidophilus and L. bulgaricus are both thermophilic lactobacilli and an active transport (permease) system is found in both species for lactose transport. The major factor affecting in vivo lactose digestion in this study appears to be the bacterial cell wall/membrane structures. That the cell wall/membrane structures of L. acidophilus are different from those of L. bulgaricus can be indirectly proven by the results of sonication time for maximum beta-galactosidase activity measurement. The results of this study indicate that L. bulgaricus is usually a better choice than L. acidophilus for manufacturing nonfermented milks for lactose maldigesters.

Animals↗
PubMed1998

Multiple lymphomatous polyposis of the gut: case report.

Multiple lymphomatous polyposis (MLP) is an uncommon type of primary non-Hodgkin's gastrointestinal B-cell lymphoma characterized by the presence of multiple lymphomatous polyps along the gut. We present a patient with MLP in which the involvement was unusually widespread. The diagnosis was confirmed by the typical polyposis lesion, histology, phenotyping and clinical presentations. A 68-year-old man had a large mass at the ileocecal valve as well as multiple polyps along the whole digestive tract. At the time of diagnosis, lymphoma had involved bone marrow, peripheral blood, spleen, prostate and peripheral lymph nodes. The patient received 8 courses of chemotherapy with no remission. He died of pneumonia 11 months after diagnosis. Clinically, the diagnosis may be confused with epithelial polyps; and histologically, the diagnosis must be distinguished from benign lymphoid proliferations as well as other types of lymphoma. The prognosis for patients with MLP is relatively poor (the median survival is usually less than 3 years).

Aged↗
PubMed1995

Restoring the apoptosis suppression response to IL-5 confers on erythroleukemic cells a phenotype of IL-5-dependent growth.

We have established a human IL-5 (hIL-5) dependent cell line, JYTF-1, derived from TF-1 parental human erythroleukemic cells by long-term cultivation in the presence of hIL-5. The ED50 values of hIL-5 for both TF-1 and JYTF-1 cell lines remained similar. However, when cells were grown in an optimal concentration of IL-5, some TF-1 cells but not JYTF-1 cells died via apoptosis. Although the rates of DNA synthesis were similar for TF-1 and JYTF-1 cells grown in IL-5, [3-H]thymidine releasing of pulse-labeled DNA analysis indicated that the viable TF-1 cells in IL-5 were more apoptosis-prone than were JYTF-1 cells. Therefore, in the JYTF-1 variant, the ability to suppress apoptosis has apparently been restored. The following findings suggest that overexpression of the hIL-5 receptor alpha-chain may be responsible for restoring the apoptosis suppression ability of IL-5: 1) the growth of JYTF-1 cells remained cytokine-dependent; 2) the proliferation of JYTF-1 cells in IL-5 was not mediated by autocrine secretion; 3) JYTF-1 and TF-1 cells responded similarly to other cytokines such as human erythropoietin; 4) Northern blot analysis revealed that JYTF-1 cells expressed approximately eightfold more IL-5 receptor alpha-chain mRNA than did TF-1. To our knowledge, JYTF-1 represents the first example in which coupling of mitogenesis stimulation and apoptosis suppression from otherwise uncoupled parental cells confers a phenotype of IL-5-dependent growth.

Apoptosis↗
PubMed1993

[Biliary ascariasis].

From January 1982 to September 1987, ten diagnosed cases of biliary ascariasis were collected among 8,160 cases who were admitted for biliary tract diseases in our hospital. It represented an incidence of 0.12% in our hospital. In our series, the patients' ages ranged from 33 to 68 years old, with a female predominances. The clinical impression on admission were those of biliary tract stone, infection or pancreatitis. Signs and symptoms of biliary ascariasis were abdominal pain, fever, jaundice, vomiting of round worms and distended gallbladder. Laboratory findings disclosed leukocytosis, mildly elevated alkaline phosphatase, transaminase and bilirubin. There was a relatively high incidence of positive bile culture for bacteria. The reliable diagnostic tools for biliary ascariasis were abdominal real-time ultrasonography and endoscopic retrograde cholangiopancreatography (ERCP). They yielded a diagnostic rate of 40% and 87.5% respectively in our series. The principles of management of biliary ascariasis were conservative treatments including intravenous fluids, nasogastric decompression, antibiotics and antihelmintic agents. Other treatments that were also tried included endoscopic removal of round worms through a T-tube, or nasobiliary drainage. Surgery was considered when there were signs of complications, such as uncontrolled sepsis or suppurative cholangitis. The prognosis of biliary ascariasis was good if patients were diagnosed and treated properly. Regular follow-up with antihelmintic agents is also recommended to avoid reinfection.

Adult↗
PubMed1993

Double primary tumors of the liver.

A rare case of double primary tumors of the liver is reported. A 69-year-old male presented with fever and right upper quadrant pain. On admission blood culture grew Salmonella group B. Laboratory data showed leucocytosis, mild elevation of aspartate aminotransferase, alanine aminotransferase and sugar, positive-HBsAg, and normal range CEA and AFP. Abdominal sonography disclosed a well demarcated solid mass and another cystic lesion with a ragged wall in the left lobe of liver. Abdominal CT revealed a mixed density solid mass in the medial segment, and laterally located cystic mass with internal septa. A preoperative diagnosis of double tumors of the left lobe of the liver was made and the patient underwent a left hepatic lobectomy. Hepatocellular carcinoma and cystadenocarcinoma were diagnosed by histopathological examination. The patient has been well without tumor recurrence after one and a half year's follow-up.

Aged↗
PubMed1990

Somatosensory evoked potentials and number connection test in the detection of subclinical hepatic encephalopathy.

To compare the diagnostic ability of somatosensory evoked potentials and the number connection test in the detection of subclinical hepatic encephalopathy, 44 decompensated cirrhotic patients with no overt encephalopathy were admitted to the study and followed up for 6 months. Twenty-two patients developed overt encephalopathy during follow-up, and were retrospectively considered as patients with subclinical encephalopathy at entry. Of the 15 patients with abnormal somatosensory evoked potentials, 14 (93%) experienced at least one episode of hepatic encephalopathy in the following 6 months, while 16 (70%) of the 23 patients with abnormal number connection test did so. The data suggested that somatosensory evoked potential measurement was less sensitive, but more specific than number connection test in the detection of subclinical encephalopathy, although the differences were not statistically significant. Besides, the number connection test is much simpler, convenient and cheap, and it specificity could be improved if the learning effect and age, education and visual factors were carefully considered. We therefore recommend using the number connection test routinely in patients with decompensated liver diseases for the detection of subclinical hepatic encephalopathy, and reserving somatosensory evoked potential measurement as a complementary examination, when appropriate, or for assessment of overt hepatic encephalopathy.

Adult↗
PubMed1989

Sonographic demonstration of free air in perforated peptic ulcers: comparison of sonography with radiography.

Abdominal sonography was performed in 283 patients with acute abdominal pain. Of these patients, 10 were diagnosed as having an acute perforated peptic ulcer (PPU) and 2 were diagnosed as having a sealed-off PPU. Sonographic findings of acute PPU are summarized. The presence of an interference echo with the shifting phenomenon is a very strong indication of the presence of free air in the abdominal cavity. Using these sonographic criteria, intraperitoneal free air was diagnosed as 9/10 patients with PPU in comparison to 8/10 by abdominal and chest radiographs. Two patients with sonographic evidence of free air, but negative X-ray studies, were later found to have free air in the subsequent radiographic studies. These findings suggest that sonography is highly sensitive in the small number of patients in whom air is found. Sonographic studies also have the advantage of detecting other changes associated with PPU, such as fluid accumulation, inflammatory mass, and thickening of the gallbladder.

Abdomen, Acute↗