Signal transduction systems employed by synthetic GH-releasing peptides in somatotrophs.
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Animals↗
Biomedical subjects
C Chen
Publications and source records attributed to C Chen.
Comparative study of antigen retrieval heating methods: microwave, microwave and pressure cooker, autoclave, and steamer.
We present a study comparing the most popular heating methods currently used for antigen retrieval (AR) immunostaining: the microwave oven, microwave with pressure cooker, autoclave, and steamer heating. A panel of 21 antibodies was tested on formalin fixed, paraffin embedded sections using these heating methods and Tris-HC1 buffer, pH 9.5, plus 5% urea as the AR solution. Three observers independently evaluated the intensity of AR immunostaining. All heating methods yielded good results for AR immunostaining. There were only minor differences among the heating methods for AR when the optimal concentration of primary antibody for normal immunostaining was used; however, background staining may occasionally be troublesome if antibodies are not retitrated and diluted further for use on tissues after AR. Significant differences were observed only after further dilution of the primary antibodies: the microwave pressure cooker, extended microwave heating (5 min x 4) and autoclave heating then showed a similar intensity of staining that was stronger than results obtained with the steamer (20 min) or regular microwave heating (5 min x 2). Extension of the steamer heating time, however, yielded equivalent results. This study indicates that different heating methods can yield similar intensities of AR immunostaining if the heating times are adjusted appropriately. It is noteworthy that, in general, the adjusted conditions for maximal retrieval differ from those most widely cited in the literature, or recommended by manufacturers. That several heating devices may provide similar results permits the use of different AR heating methods according to the equipment available. This study also is an early step in standardizing the AR immunostaining protocol by providing uniform conditions for "maximal retrieval" as a common end point for all laboratories.
Antigens↗
Halymecins, new antimicroalgal substances produced by fungi isolated from marine algae.
Novel antimicroalgal substances halymecins A (1), B (2) and C (3) were isolated from the fermentation broth of a Fusarium sp. and halymecins D (4) and E (5) from an Acremonium sp. The structures of these halymecins, Fig. 1, were determined based on extensive 2D NMR studies as well as mass spectral data. These chemical structures are conjugates of di- and trihydroxydecanoic acid. Halymecin A showed antimicroalgal activity against Skeletonema costatum.
Acremonium↗
Living arrangements and economic support for the elderly in Taiwan.
"This paper aims to find out the role of living arrangements in economic support for the elderly in Taiwan.... To fulfill this goal, primary and secondary sources of living costs are used to derive four types of economic support for the elderly.... Our analytical results suggest that living arrangements play a role of specification. Of the elderly who are not living with children, these have substantially greater proportions of the independent type than those living with children." (SUMMARY IN CHI)
Asia↗
[Quantitative changes of flavonoids in Epimedium koreanum Nakai in different collecting periods].
The quantitative changes of flavonoids in Epimedium koreanum in different collecting periods were determined by HPLC and UV spectrophotometry. The result shows that the highest content of flavonoids is found in the flowering period (May).
Drugs, Chinese Herbal↗
Influence of age and gender on valproic acid glucuronidation in rats.
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Age Factors↗
Measurement of urinary estrogen metabolites using a monoclonal enzyme-linked immunoassay kit: assay performance and feasibility for epidemiological studies.
We evaluated an enzyme-linked immunoassay kit (Estramet 2/16) for the measurement of 2-hydroxyestrone (2-OH E1) and 16-alpha hydroxyestrone (16 alpha-OH E1), major metabolites of estradiol. Urine samples from 14 healthy premenopausal women on days 1, 8, 15, and 22 of their menstrual cycle were assayed along with standards, kit controls, and in-house controls. The intra-assay percentage CVs of 2-OH E1, 16 alpha-OH E1, and the 2-OH E1: 16 alpha-OH E1 ratio were 6.8, 7.4, and 1.8, respectively; the interassay percentage CVs were 15.3, 30.7, and 23.3, respectively. The assay linearity was between 0 and 40 ng/ml. The mean 2-OH E1:16 alpha-OH E1 ratio was relatively constant throughout the day, but it increased by around 50% between the follicular and luteal portions of the menstrual cycle. Individual reagent kits within each lot for 16 alpha-OH E1 were stable for 2 weeks. There was considerable lot-to-lot variation over a 5-month period. In lots used during the last 2 months of the study, values of 2-OH E1 from in-house controls increased by 30-50%, and those of 16 alpha-OH E1 by 50-100%, relative to values obtained initially on the same samples. Depending on the lot, the ratio of the two metabolites ranged from 2 to 5.5. These data suggest that the assay is useful for studies where samples can be assayed with the same kit lot over a period of not more than 2 weeks, but that it is not now suitable for studies that extend over a long enough period of time so that multiple kit lots are required.
Adolescent↗
The small aortic root and the Medtronic Hall valve: ultrafast computed tomography assessment of left ventricular mass following aortic valve replacement.
BACKGROUND AND AIMS OF THE STUDY: The selection of an appropriate size aortic valve substitute with respect to patient size and life-style, in the presence of a small aortic root, is problematic, and a decision to enlarge the aortic annulus is often arbitrary. An aortic valve substitute-patient mismatch may place an excessive load on the left ventricle resulting in residual left ventricular mass with attendant patient morbidity and mortality. The aim of this study was to assess the adequacy of the Medtronic Hall valve in the small aortic root using ultrafast computed tomography analysis of left ventricular mass. MATERIALS AND METHODS: In 13 patients the smallest Medtronic Hall valves (size 20 and 21; measured internal orifice area of 2.01 cm2 for both) were used to replace the native aortic valve. All patients had aortic stenosis, and left ventricular hypertrophy was established by echocardiography. The mean body surface area was 1.8 +/- 0.2 m2 (range 1.50-2.06 m2) and the mean weight was 75 +/- 15 Kg (range 50-97 Kg). The mean preoperative New York Heart Association functional class was 3.54 +/- 0.5. RESULTS: There was no operative or late mortality. At a mean follow up of 22 months after aortic valve replacement, the mean left ventricular mass index was 89 +/- 11.4 g/m2 (normal left ventricular mass index by ultrafast computed tomography = 97 +/- 14 g/m2) and mean New York Heart Association functional class was 1.6 +/- 0.8 (p (Binomial) = 0.0001 compared to preoperative). Doppler echocardiogram demonstrated a mean gradient across the prosthetic valve of 17 +/- 7 mmHg. There was no trend towards greater left ventricular mass index in patients with greater body surface area or weight. In no patient was the aortic annulus enlarged. CONCLUSIONS: Trends from this preliminary data suggest that implanting the smallest Medtronic-Hall aortic valves (sizes 20 and 21) results in normal left ventricular mass following aortic valve replacement in patients up to a body surface area of 2.06 m2 and provides support for the notion that an aortic annulus enlarging procedure was not necessary in this group of patients.
Adult↗
Glutathione S-transferase M1 genotypes and the risk of anal cancer: a population-based case-control study.
Some studies have reported an association of the GSTM1-null genotype with the risk of smoking-related cancers, such as lung, bladder, and colon cancer. Because the risk of anal cancer is strongly associated with a history of cigarette smoking, we examined whether the GSTM1-null genotype is a susceptibility marker for anal cancer. We obtained peripheral blood specimens from residents of western Washington who were diagnosed with squamous or transitional cell tumor of the anus between April 1991 and June 1994. Eligible for inclusion were persons 18-74 years of age, with either invasive or in situ lesions. Specimens were also obtained from controls identified via random-digit dialing of western Washington households. We determined GSTM1 genotypes of 71 cases and 360 controls by PCR using primer pair 5'-AACTCCCTGAAAAGCTAAAGC-3' and 5'-GTTGGGCTCAAATATACGGTGG-3'. The frequency of the GSTM1-null genotype in controls was approximately 57%; this differed little in relation to age, sex and smoking status. The incidence of anal cancer appeared to be reduced in persons with the GSTM1-null genotype; only 39.4% of cases had this genotype (age-adjusted odds ratio = 0.5, 95% confidence interval = 0.3-0.9). This inverse association was restricted to persons who had ever smoked cigarettes and was present in both women and men (and in the latter, in both those who had and did not have a male sexual partner). Our data strongly suggest that persons with the GSTM1-null genotype are not at increased risk of anal cancer, and may well be at a decreased risk.
Adolescent↗
Enhanced efficacy of combination of IL-2 gene and IL-6 gene-transfected tumor cells in the treatment of established metastatic tumors.
IL-2 and IL-6 are important cytokines which have potent antitumor effects and can cooperate to induce immune responses more effectively. IL-2 gene or IL-6 gene-transfected tumor cells exhibited reduced tumorigenicity and decreased metastatic potential. In order to increase the therapeutic efficacy of IL-2 gene-, IL-6 gene-modified tumor vaccines, the experimental pulmonary metastatic melanoma-bearing mice were treated with inactivated IL-2 gene-transfected tumor cells and inactivated IL-6 gene-transfected tumor cells. After the combined vaccination, the pulmonary metastases were reduced more significantly and the survival time of tumor-bearing mice was also markedly prolonged. The CTL activity, NK activity and IL-2-induced LAK activity, IL-2 and TNF secretion from the splenocytes of the above tumor-bearing mice increased more significantly than that of tumor-bearing mice vaccinated with IL-2 gene-transfected vaccine or IL-6 gene transfected vaccine alone. These results demonstrated that the combined use of IL-2 gene-transfected tumor vaccine and IL-6 gene-transfected tumor vaccine could achieve more potent antitumor effect via more effective activation of specific and non-specific antitumor immune responses.
Animals↗
T7-promoter-based Escherichia coli expression system induced with bacteriophage M13HEP.
The bacteriophage M13HEP was constructed by cloning the T7 RNA polymerase gene into phage M13mp18 RF DNA to express T7 RNA polymerase under the control of the lac promoter. Through M13HEP phage infection, T7 RNA polymerase could be introduced into an expression strain and heterologous genes under the control of the T7 promoter can be induced to express. Using this phage M13HEP induction system, many heterologous genes, especially some genes whose products are toxic to the host strain, were successfully expressed. By transferring F' pilli from E. coli XL1-blue to E. coli HMS174, a new E. coli strain HMS174F' was obtained to make the construction, expression, and single-stranded DNA rescue of the T7 expression plasmid be conveniently performed in the same strain.
Bacteriophage M13↗
[Ultrastructural changes in various cataractous lenses in rats].
OBJECTIVE: To study the ultrastructural changes of lenses aged 50 days from normal rats and rats with three kinds of cataract. METHOD: Transmission electron microscope (TEM) was used to investigate the ultrastructural changes of normal lens, selenium, galactosemic and congenital cataracts in the rat. RESULTS: In the normal group, the structure of cell membrane in cortex is not changed obviously, but in the lens nucleus there are slight cellular degeneration, low cytoplasmic density and the destruction of intercellular junctional complexes. In the selenium cataratous lens, in the lens cortex and nucleus the cellular junctional complexes are damaged severely, the cystic degeneration of mitochondria in the cytoplasm is obvious, the cytoplasmic density becomes lower and slight liquefaction can be observed in some parts of cytoplasm. In the galactosemic cataractous lens, in the cortex obvious liquefaction, vesicles and globular structures can be found within the cytoplasm, intercellular spaces are enlarged and liquified markedly, and in the lens nuclear area the cytoplasm appears as fine sands. In congenital cataractous lens, the cellular structure in cortex is essentially normal, but there are marked destruction of junctional complexes, obvious cystic degeneration of mitochondria and cytoplasmic aggregation with uneven distribution in the lens nuclear area. CONCLUSION: The ultrastructural changes in different kinds of cataractous lenses depend on the extent and location of opacification in lenses.
Animals↗
Neuregulins as potential drugs for neurological disorders.
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Animals↗
A one-hand operation gun for transrectal prostate biopsy.
OBJECTIVE: To develop a new automatic biopsy device (ABD) that enables a radiologist to obtain multiple samples with one hand and free the other hand to handle the ultrasonic scanner for continuous monitoring. MATERIALS AND METHODS: The new ABD developed by us in April 1994 enabled a radiologist to complete all the biopsy procedures including loading and reloading the spring system, firing the device, emptying the specimen, selecting the depth of needle advancement, and multiple sampling, simply by pressing 3 buttons in turn with his/her right thumb. Using this new ABD, transrectal prostate biopsy under the guidance of transrectal ultrasonic imaging was performed in 60 consecutive cases of prostate diseases. Each biopsy procedure was completed by a single radiologist, who was able to obtain multiple specimens with one biopsy needle, using only one hand and freeing the other hand for the manipulation of the ultrasonic scanner for guidance. RESULTS: A total of 265 satisfactory core tissue specimens of 285 needle passes (93%) were obtained from the 60 patients. Definite pathologic diagnoses were made for all the 60 patients (100%). No serious biopsy-related complications were observed. The main complications were hematuria in 24 of 60 (40%) patients and fever in 5 (8.3%). CONCLUSION: On the basis of our experience with the 60 patients, this new ABD can be operated smoothly and effectively with the right hand, while the left hand is freed to handle the ultrasonic transducer for continuous monitoring.
Biopsy, Needle↗
[Use of an anorectal driving device in the sphincter-saving operation for low rectal carcinoma].
UNLABELLED: The anastomosis with tubular anastomotic instrument for the surgical resection of the low rectal carcinoma with preserved anus is difficult to perform because of the deep location of the tumor and retraction of the paraproctium to the pelvic floor. From 1986 a self-made anorectal driving device was applied to facilitate anastomosis with the tubular anastomotic instrument. Ninety-six cases of low rectal carcinoma were so treated in 1986-1990. Eighty-five cases in 1980-1985 treated by tubular anastomosis without the use of the driving device served as the control. The success rate of anastomosis increased from 45.9% to 77.1% (P < 0.01), incidence of anastomotic fistula decreased from 11.6% to 3.1% (P < 0.01), the average operation time was reduced from 211 to 183 minutes (P < 0.01). CONCLUSION: The pelvic and anoretal tissue can be pushed upwards by this device, which facillitates complete dissection of the tumor and anastamosis by tubular anastomotic instrument.
Anastomosis, Surgical↗
[Primary epididymal tumors: report of 24 cases].
24 cases of primary epididymal tumors including 23 benign and 1 malignant tumors were treated. In these cases, 66.7% situated at epididymal tail, and 12.5% involved both tail and body. Smooth muscle tumor of one case was bilateral, and adenomatoid tumor of another one was multiple. The symptoms of primary epididymal tumors were mild even absent, so the tumor was easily confused with non-tumorous mass of epididymis. Benign epididymal tumor should be differentiated from tuberculosis, chronic inflammation or granuloma. Besides signs of malignant mass, malignant epididymal tumor usually showed thickened spermatic cord, especially enlarged ductus deferens. The removal of the tumor mass or whole epididymis of the same side could cure benign epididymal tumor without recurrence. Malignant epididymal tumor should be treated as malignancy of testis or spermatic cord, with adjuvant chemotherapy or radiotherapy as indicated by the pathological type.
Adenomatoid Tumor↗
[Water soluble contents of Chinese drug beimu, the bulbs of Fritillaria plants].
Based on platelet aggregation induced by platelet activating factor (PAF), the active fraction with inhibiting effect was screened from four species of Chinese drung Beimu, the bulbs of Fritillaria przewalskii, F. ussurienis, F. anhuiensis and F. thunbergii. According to the experimental results, the active water soluble fraction of F. ussuriensis was further studied. Two nucleosides, thymidine and adenosine were isolated. Platelet aggregation assay shows that adenosine is the chief aggregation inhibitor with 1% = 42 at 5 microns. It is suggested that nucleosides may be the other type of active constituent besides alkaloids in the Fritillaria plants.
Adenosine↗
[Quantitative study of magnoflorine in Epimedium koreanum Nakai].
The content of magnoflorine in different parts of Epimedium koreanum was determined by using HPLC. The results showed that magnoflorine existed in every part of the plant and the highest content was found in the rhizoma. A new index and a reliable method are correspondingly provided for the quality control of E. koreanum.
Aporphines↗