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Biomedical subjects

C Y Lin

Publications and source records attributed to C Y Lin.

At least 505 records · Page 28Linked to original sources
PubMed1966

Association of D-RNA with Polyribosomes in the Soybean Root.

Ribosomes from soybean root tips were shown to consist of about 75% polyribosomes based on size distribution on sucrose gradients. Electronmicrographs showed the presence of ribosome clusters in normal preparations and only monomers and dimers in ribonuclease-treated preparations. The polyribosome preparations, but not single ribosomes, showed good in vitro amino acid incorporating activity.D-RNA was associated with the ribosome preparations, and preferentially in the polyribosome structure. It is suggested that at least a part of the soybean D-RNA represents a class of messenger RNA.

Journal Article↗
PubMedDate not supplied

A method for quantifying artefacts in mapping methods illustrated by application to headbanging.

Maps of disease rates (and other quantities) often must contend with variance associated with variable population sizes and low incidence within spatial units. These characteristics can lead to substantial statistical noise that can mask underlying spatial variation. As Gelman and Price illustrated, most conventional mapping methods fail to address this problem, and in fact can introduce statistical artefacts; mapped quantities can show spatial patterns even when there are no spatial patterns in the underlying parameter of interest. Kafadar evaluated the performance of the headbanging algorithm for spatial smoothing (Tukey and Tukey, Hansen) for eliminating small scale variation and preserving edge structure. Here we perform a simulation study to investigate the artefacts of maps smoothed by unweighted and weighted headbanging. We find substantial artefacts that depend on the spatial structure of the statistical variation (for example, the spatial pattern of sample sizes) and on the details of the spatial distribution of geographic units. The methods used here could readily be adapted to study other spatial smoothers; we choose headbanging because (i) it is an important method used in practice, and (ii) its heavily computational nature is naturally studied using simulation (in contrast to the analytical methods used by Gelman and Price).

Artifacts↗
PubMedDate not supplied

Simple, effective procedure with few complications for esophageal varices.

The surgical morbidity, mortality, and effectiveness of a modified nonshunting operation that includes splenic artery division instead of splenectomy, devascularization, and esophageal transection (SAD group) were evaluated. Eighteen cirrhotic patients with varices who underwent this modified procedure were compared with 54 patients treated with a conventional nonshunting operation (splenectomy group). Results show that immediate effects on portal pressure and preservation of portal perfusion between the two groups were similar. The operative time is shorter (p < 0.05), and the bleeding amount is less (p < 0.005) in the SAD group than in the splenectomy group. No surgical mortality and no major complications were noted in the SAD group. A surgical mortality of 2.3% and 30% was noted for the elective and emergency operations of the splenectomy group, respectively. There was no encephalopathy in the SAD group but one in the splenectomy group. Recurrent bleeding occurred in three patients of the splenectomy group 1 year after surgery but none in the SAD group. These data indicate that this modified procedure is a simple and effective operation with few complications for esophageal varices.

Adult↗
PubMedDate not supplied

A comparative study on the immunological effects of bovine and porcine thymic extracts: induction of lymphoproliferative response and enhancement of interleukin-2, gamma-interferon and tumor necrotic factor production in vitro on cord blood lymphocytes.

Forty samples of cord blood lymphocytes were isolated from 40 normal healthy full-term newborns. The initial 20 samples were used to determine the dose-response curve of three different thymic extracts (TP-1, bovine thymic extract; TG-15-I and TG-15-II, both porcine thymic extracts) and one of renal origin (KG-1) as a control of non-lymphoid organ extract, by measuring the E-rosette T cells. Results showed that E-rosette T cells increased significantly when the thymic extract concentration was increased to 12.5 micrograms/ml. However, there was no statistical difference between TP-1, TG-15-I and TG-15-II in the increase of E-rosette-forming cells. The remaining 20 samples were preincubated with 0, 12.5, 25 or 50 micrograms/ml of thymic extracts. It was observed that the lymphoproliferation, interleukin-2 (IL-2), gamma-interferon (IFN-gamma) and tumor necrotic factor (TNF) production were all significantly increased after thymic extract treatment. No statistical difference between these three thymic preparations in the stimulation of lymphoproliferative response was found. However, among the three thymic extracts, TP-1 appears to induce the highest amounts of IL-2, IFN-gamma and TNF. Of the TG-15-I and TG-15-II, the former stimulates higher IL-2 production whereas the latter enhances IFN-gamma and TNF production. The different immunostimulating effects and potencies that these three thymic extracts showed may reflect not only the species difference but also the difference in preparation procedures. Different components in these thymic extracts may be responsible for different biological activities. Results from these comparative studies may provide useful information in future clinical trials for the treatment of the primary immunodeficiency diseases according to their pathogenesis and may also indicate a possible beneficial effect of the combination of chemotherapy and thymic extracts.

Animals↗
PubMedDate not supplied

Aplysia brasiliana neurons R3-R14: primary structure of the myoactive histidine-rich basic peptide and its prohormone.

Neurons R3-R14 of the marine mollusc Aplysia are model neuroendocrine cells thought to regulate cardiovascular activity in vivo. The cells express a gene encoding three peptides--peptides I, II and the histidine-rich basic peptide (HRBP)--each of which has been chemically characterized in Aplysia californica. In the studies presented here, HRBP and its prohormone (proHRBP) were purified from A. brasiliana abdominal ganglion extracts by reversed-phase high-performance liquid chromatography and characterized by amino acid compositional and sequence analyses. ProHRBP was an 85-residue peptide whose sequence was: NH2-Glu-Glu-Val-Phe-Asp-Asp-Thr-Asp-Val-Gly-Asp-Glu-Leu-Thr-Asn-Ala-Leu- Glu-Ser - Val-Leu-Thr-Asp-Leu-Lys-Asp-Lys-Arg-Asp-Ala-Glu-Glu-Pro-Ser-Ala-Phe-Met- Thr-Arg - Leu-Arg-Arg-Gln-Val-Ala-Gln-Met-His-Ile-Trp-Arg-Ala-Asn-His-Asp-Arg-His- His-Ser - Thr-Gly-Ser-Gly-Arg-His-Ser-Arg-Phe-Leu-Thr-Arg-Asn-Arg-Tyr-Gly-Gly-Gly- His-Leu - Ser-Asp-Ala-COOG. It differed from A. californica pro-HRBP at seven of the 85 positions. Compositional and sequence analyses demonstrated that A. brasiliana HRBP was a 43-residue peptide corresponding to residues 43 through 85 of proHRBP, and that a significant proportion of the isolated peptide possessed a blocked NH2 terminus. Although this sequence differed from that of A. californica HRBP at five of 43 residues, the two peptides were approximately equipotent in inducing contractions of A. californica crop muscle in vitro, suggesting that the substituted residues may not be critical for biological activity.

Amino Acid Sequence↗
PubMedDate not supplied

Leakage of disposable breathing circuits.

STUDY OBJECTIVE: To determine the sites and rates of the leakage of disposable breathing circuits. DESIGN: Nonclinical, experimental study. SETTING: Experimental laboratory. INTERVENTIONS: To identify in vitro the leakage sites by bubble test and to measure the leakage rate by the increased oxygen (O2) flow needed to maintain the circuit pressure provided by an anesthesia machine previously verified to have no leaks. Breathing circuit pressures measured with a sphygmomanometer of 30, 50, 70, and 100 mmHg were studied. MEASUREMENTS AND MAIN RESULTS: Ninety-seven disposable and three reusable breathing circuits from seven manufacturers were investigated for leakage. There was a linear relationship between the circuit pressure and O2 flow at which leaks occurred. No leakage was detected in reusable circuits at 30 mmHg of circuit pressure. Leakage was found in two of the six junctions between the patient adapter and the corrugated tubing in the reusable breathing circuits at a circuit pressure of 100 mmHg. In 90% of the disposable circuits tested, the leakage rate was less than 75 ml/min at 30 mmHg of circuit pressure, but there was a wide variation in the amount of leakage among the circuits of different companies. Almost all the leakage sites were located at connections in the circuit and not in the corrugated tubing. The most common site of leakage in the disposable circuits was the junction between the patient adapter end and the corrugated tubing (57%) rather than the swivel piece (40%). CONCLUSIONS: Most disposable breathing circuits can be used safely for closed-circuit anesthesia, as the leakage volume is too small to be of clinical importance. The variation in the leakage rates stresses the importance of quality control of the connector seals.

Anesthesia, Closed-Circuit↗
PubMedDate not supplied

Endoscopic injection sclerotherapy versus conservative treatment for patients with unresectable hepatocellular carcinoma and bleeding esophageal varices.

We performed endoscopic injection sclerotherapy (EIS) in the treatment of 37 patients with bleeding esophageal varices due to unresectable hepatocellular carcinoma (HCC). The results were compared with those in another 33 HCC patients treated only conservatively, without EIS, during the same period. A majority of both groups died within 3 weeks after treatment. Comparing the two groups, there was no significant difference in fatal bleeding (66% vs 75%), but significantly fewer of the EIS patients died of the index hemorrhage (43% vs. 83%; p less than 0.01). Also, in the absence of portal vein thrombosis, EIS significantly reduced the risk of fatal bleeding (31% vs. 73%; p less than 0.25). The mean days of survival were 32 +/- 15 (range, 2 to 320) in the EIS group and 10 +/- 14 (range, 2 to 270) in the compared group (p less than 0.001). We conclude that EIS provides temporary control of acute esophageal variceal bleeding in patients with unresectable HCC. The major factors contributing to EIS failure are the lethal propensity of the underlying disease and portal vein thrombosis.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

The natural history (fading time) of stigmata of recent hemorrhage in peptic ulcer disease.

From October 1991 to December 1992, 144 patients with bleeding peptic ulcer and stigmata of recent hemorrhage were included in a study designed to investigate, by means of endoscopic examinations repeated at 2-day intervals, the evolutionary development of stigmata of recent hemorrhage, such as visible vessels, and to determine the time required for each type of stigma to fade. Eighty-five patients underwent endoscopic follow-up until the stigmata had disappeared. A visible vessel takes about 4.1 +/- 2.1 days to disappear, requiring significantly more time than an adherent clot or an old stigma, which take 2.4 +/- 0.8 days and 2.4 +/- 1.3 days, respectively (p < .05). Bleeding does not recur after stigmata disappear. Time required for stigmata to fade is not affected by age, sex, smoking, history of peptic ulcer, ulcer location, severe bleeding, underlying systemic disease, or endoscopic local therapy. While healing, stigmata of recent hemorrhage evolve through a sequence of phases: a visible vessel may or may not appear as an adherent clot and then as a red or black flat spot before disappearing.

Endoscopy, Gastrointestinal↗
PubMedDate not supplied

QT interval effects of cisapride in the clinical setting.

PURPOSE: The clinical effect of cisapride on QT intervals was prospectively studied. SUBJECTS: Consecutive adult patients were recruited in whom cisapride was indicated for gastroesophogeal reflux, gastric ulcer, duodenal ulcer, diabetic gastroparesis or chronic constipation refractory to laxatives. Exclusion criteria included disorders and medications affecting cardiac conduction, electrolyte homeostasis, drug clearance and membrane stability. METHODS: Seventy-five patients were included and followed at 1 to 2 week intervals. Patients took cisapride 5 mg thrice daily for 1 to 4 weeks (lower dose stage), followed by 10 mg thrice daily for another 1 to 4 weeks (higher dose stage). Twelve-lead ECGs were performed before commencing cisapride (group B), at completion of the lower dose stage (group L) and at completion of the higher dose stage (group H). RESULTS: No patients experienced presyncope or syncope. Seventeen patients failing to comply, and 7 complaining of abdominal discomfort or diarrhea were excluded, leaving 51 participants. Group H's corrected QT interval (QTc) was longer than group B's by 13+/-15 ms (P<0.001), and longer than group L's by 7+/-11 ms (P<0.001). Group L's QTc was longer than group B's by 7+/-21 ms (P<0.05). QT dispersion did not differ significantly among groups. Neither torsade de pointe nor ventricular tachycardia were noted in Holter monitoring of 33 patients during the higher dose stage. CONCLUSION: cisapride dose-dependently prolongs the QT interval. Further study is needed to examine the arrhythmogenicity of cisapride in higher doses and for longer durations.

Adult↗
PubMedDate not supplied

Nadph-diaphorase activity in corpus allatum cells of the cockroach, Diploptera punctata.

Using the fixation insensitive NADPH-diaphorase reaction as a histochemical marker for the enzyme nitric oxide synthase (NOS), we investigated the possible sites of putatively NOS-related NADPH-diaphorase in the brain and retrocerebral complex of the cockroach, Diploptera punctata. In the cerebral ganglion, NADPH-diaphorase expression was localized in antennal lobes, optic lobes, mushroom bodies and neurosecretory cells. The highest NADPH activity was detected in the corpora allata (CA). Spectrophotometric quantitation indicated that NADPH-diaphorase activity first increased and then decreased (cycled) in the CA of mated females. In addition, during the first ovarian cycle, NADPH-diaphorase activity fluctuated concurrently with cyclic changes in the size of corpus allatum cells. In virgin females, NADPH-diaphorase activity remained at a low level, but it increased if the neural connectives between CA and brain were severed, indicating that the brain inhibited NADPH-diaphorase expression in the CA. Although nerve terminals were abundant in the CA, NADPH-diaphorase was clearly endogenous and synthesized by glandular cells, as was shown by histochemical staining of the cytosol in all dissociated cells of the CA. We have also demonstrated NADPH-diaphorase activity in the CA of the American cockroach Periplaneta americana, the house cricket Acheta domesticus, the lepidopteran Leucania loreyi, and the fruit fly Drosophila melanogaster, suggesting that NOS occurs in the CA of most, if not all insects. It is therefore possible that corpus allatum cells release NO, along with juvenile hormone, which presumably can function as a messenger molecule.

Animals↗
PubMedDate not supplied

Fungal exposure of children at homes and schools: a health perspective.

The authors investigated airborne fungal exposure of Taiwanese children at homes and schools-locations where they spent the majority of their time. Pairs of asthmatic and healthy children, matched by age, gender, classes (schools), and residence, participated in the study. Airborne fungal concentrations at homes and schools, and time-activity data of the study subjects were collected. In winter, the indoor geometric mean concentration was 9,672.1 colony-forming units per cubic meter and 4,380.9 colony-forming units per cubic meter in summer. The indoor/outdoor concentration ratio was similar in all homes for both seasons. Fungal concentrations in southern Taiwan were high during both winter and summer. Personal fungal exposure was not statistically different between asthmatic and nonasthmatic children, after adjustment of time-activity patterns. Higher symptom scores were shown for children in homes with higher fungal exposures.

Air Pollution, Indoor↗
PubMedDate not supplied

Markers within the regulatory region of the growth hormone receptor gene and their association with milk-related traits in Holsteins.

We studied sequence variations in the regulatory region of the bovine growth hormone receptor gene. A polymerase chain reaction (PCR)-based method for detecting AluI, AccI, and StuI restriction fragment length polymorphisms (RFLPs) in the 5' flanking region of the bovine growth hormone receptor gene was developed and tested for association with milk-related traits in Holstein bulls. Allele frequencies of the polymorphisms in two groups of Holstein progeny-tested bulls born from 1950 to 1970 and in the 1980s, respectively, were estimated. The allele frequency of the AluI(-) allele was 0.63 and 0.42 in the bulls from 1950 to 1970 and in the 1980s, respectively. The frequency of the StuI(-) allele was 0.14 and 0.07 in the two respective bull groups. Allele frequency for AccI(-) allele was about 0.22 in both bull groups. The differences in allele frequencies for the AluI polymorphism in the two bull groups were significantly different (P < or = .005). The AluI(+/+) bulls had a higher estimated breeding value (EBV) for fat (P < or = .016) than AluI(-/-) bulls. The average effect of allele substitution for the AluI polymorphism was +/- 8 for fat EBV. The AluI polymorphism could be further evaluated for use in marker-assisted selection in dairy cattle.

Alleles↗
PubMedDate not supplied

Human papillomavirus genotyping by a polymerase chain reaction-based genechip method in cervical carcinoma treated with neoadjuvant chemotherapy plus radical surgery.

The aim of this study was to evaluate the accuracy of human papillomavirus (HPV) genotyping by a polymerase chain reaction (PCR)-based genechip method and to determine the prognostic value of HPV genotype in bulky stage IB or IIA cervical carcinoma treated with neoadjuvant chemotherapy (NAC) and radical surgery. A total of 149 patients had adequate tissue for the study. The SPF1/GP6+ primers were used to amplify a 184 bp fragment. The amplimers were submitted for direct sequencing and hybridization with a genechip using revert-blot detection of 39 types of HPV DNA in a single reaction. Two runs of PCR with respective hybridization were performed for each tumor. The complete concordance of HPV genotyping was 80.5% (120/149) of the paired genechip results. The kappa coefficient was 0.634 (P < 0.0001). HPV DNA sequences were detected in 100% of the specimens, among which 67.8% harbored single type and 32.2% contained multiple types. HPV-16 was detected in 98.7%, HPV-18 in 22.8%, HPV-31 in 0.7%, HPV-45 in 1.3%, HPV-52 in 2.0%, HPV-58 in 6.7%, HPV-59 in 4.7%, and HPV-67 in 0.7%. In multivariate analyses, the HPV genotype [HPV-18 or HPV-16 and HPV-18 only versus all others: relative risk (RR), 2.33; 95% CI, 1.17-4.64; P = 0.016] and pre-NAC tumor size (>5 versus </=5 cm: RR, 2.25; 95% CI, 1.13-4.48; P = 0.021) were significantly related to overall survival. This PCR-based genechip method is sensitive and reproducible for HPV genotyping. The association of HPV-18 or HPV-16 and HPV-18 with poor outcome in cervical carcinoma treated with NAC plus radical surgery is confirmed.

Antineoplastic Agents↗
PubMedDate not supplied

A prospective evaluation of biopsy site in the diagnosis of gastric malignancy: the margin or the base?

The diagnostic value of endoscopic biopsy from the ulcer margin (six specimens) and the base (six specimens) in 46 cases of gastric malignancy was evaluated. The biopsy positive rates for malignancy from the ulcer margin and the base were 42 of 46 (91.3%) and 37 of 46 (80.4%), respectively (P = 0.2312). The diagnostic positive rate was increased to 95.6% (44 of 46) when the results of 12 biopsy specimens obtained from the ulcer margin and the base were combined. The diagnostic positive rate was not statistically different when the morphology or the location of the gastric malignancy was considered. No complication of massive bleeding or perforation was found after both sites had been biopsied. It is concluded that the margin and the base of a gastric malignant ulcer are both suitable and diagnostically effective for endoscopic biopsy. If the ulcer margin of the gastric malignancy is difficult to approach, the ulcer base appears to be a satisfactory alternative site for endoscopic biopsy.

Adenocarcinoma↗