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51.
We describe a highly efficient stable gene transfection procedure for Chinese hamster ovary (CHO) cells using a modification of the calcium phosphate-DNA coprecipitation method. We have found that treatment of CHO cells with chloroquine increases the efficiency of gene transfer by up to 20-fold (from approx. 0.01% to approx. 0.2%) when transfection is done using the pSV2-neo plasmid. The optimized transfection procedure requires that CHO cells to be incubated with calcium phosphate-DNA coprecipitate and chloroquine (100 µM) for a total of 16 h. By using high-molecular-weight human genomic DNA as a DNA source for transfection, we show that this procedure is equally efficient for stably transferring a much larger gene, such as the 49-kb human hypoxanthine phosphoribosyltransferase gene. 相似文献
52.
Botulinum versus tetanus neurotoxins: Why is botulinum neurotoxin but not tetanus neurotoxin a food poison? 总被引:2,自引:0,他引:2
Botulinum and tetanus neurotoxins, produced by Clostridium botulinum and Clostridium tetani, respectively, are the most poisonous poisons known to mankind. Although botulinum and tetanus neurotoxins share several characteristics, such as similar mol. wts, similar macrostructure, virtually identical mode of action, and a strong amino acid sequence homology, the two neurotoxins differ in one very significant way; only botulinum neurotoxin is a food poison. Factors responsible for the food poisoning potential of botulinum neurotoxins seem to be a group of complexing proteins that are also produced by C. botulinum, and are known to associate with the neurotoxin. Translation products of nucleotide sequences upstream to the neurotoxin genes of serotypes A, B, C, D, E and F botulinum neurotoxin reveal the location of genes for one of the complexing proteins that could be transcribed as polycistronic mRNA to include neurotoxin sequences. No such protein seems to be present in C. tetani, suggesting that the lack of complexing proteins might be responsible for tetanus not being a food poison. 相似文献
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54.
Kallol Ray Chaudhuri Pablo Martinez-Martin Anthony H V Schapira Fabrizio Stocchi Kapil Sethi Per Odin Richard G Brown William Koller Paolo Barone Graeme MacPhee Linda Kelly Martin Rabey Doug MacMahon Sue Thomas William Ondo David Rye Alison Forbes Susanne Tluk Vandana Dhawan Annette Bowron Adrian J Williams Charles W Olanow 《Movement disorders》2006,21(7):916-923
Nonmotor symptoms (NMS) of Parkinson's disease (PD) are not well recognized in clinical practice, either in primary or in secondary care, and are frequently missed during routine consultations. There is no single instrument (questionnaire or scale) that enables a comprehensive assessment of the range of NMS in PD both for the identification of problems and for the measurement of outcome. Against this background, a multidisciplinary group of experts, including patient group representatives, has developed an NMS screening questionnaire comprising 30 items. This instrument does not provide an overall score of disability and is not a graded or rating instrument. Instead, it is a screening tool designed to draw attention to the presence of NMS and initiate further investigation. In this article, we present the results from an international pilot study assessing feasibility, validity, and acceptability of a nonmotor questionnaire (NMSQuest). Data from 123 PD patients and 96 controls were analyzed. NMS were highly significantly more prevalent in PD compared to controls (PD NMS, median = 9.0, mean = 9.5 vs. control NMS, median = 5.5, mean = 4.0; Mann-Whitney, Kruskal-Wallis, and t test, P < 0.0001), with PD patients reporting at least 10 different NMS on average per patient. In PD, NMS were highly significantly more prevalent across all disease stages and the number of symptoms correlated significantly with advancing disease and duration of disease. Furthermore, frequently, problems such as diplopia, dribbling, apathy, blues, taste and smell problems were never previously disclosed to the health professionals. 相似文献
55.
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E J Bromet J E Schwartz S Fennig L Geller L Jandorf B Kovasznay J Lavelle A Miller C Pato R Ram 《Schizophrenia bulletin》1992,18(2):243-255
This article describes the rationale, aims, and methodology of an epidemiological study of psychosis being conducted in Suffolk County, New York. A sample of first-admission patients is drawn from 10 inpatient and 25 outpatient facilities. Diagnostic psychosocial interviews are conducted shortly after admission to treatment, and at 6- and 24-month followup. Consensus diagnoses are made after each interview. Demographic and clinical background characteristics of the first 250 subjects enrolled over a 2-year period are presented here. The response rate was 76 percent. Based on the initial interview, 75 percent of subjects received a diagnosis involving psychosis. The three most common diagnoses were schizophrenia, bipolar disorder with psychotic features, and major depression with psychotic features. Among subjects with psychosis, 58 percent of males and 29 percent of females had a history of substance abuse/dependence. Gender differences were found on several background and clinical characteristics. Males were somewhat younger, less likely to have ever married, and had less education. Although the median length of hospitalization was the same for females and males (27 days), females were more likely to be hospitalized within 1 month of the occurrence of their first psychotic symptom (60% of females compared to 37% of males). Subjects with schizophrenia-related disorders were significantly more impaired on an assessment of negative symptoms than were affectively ill subjects, but clinical ratings of depression were not significantly different across diagnostic groups. 相似文献
57.
Paulo Rogério Ferreti Bonan Estela Kaminagakura Fábio Ramoa Pires Pablo Agustin Vargas Oslei Paes de Almeida 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2006,101(2):205-211
OBJECTIVE: The aim of this work was to study cytokeratin (Ck) expression in initial radiation-induced oral mucositis. STUDY DESIGN: Eleven cases of initial radiomucositis of the buccal mucosa and 9 normal specimens were immunostained for Ck 1, 5, 6, 7, 8, 10, 14, 16, 18, and 19 by immunoperoxidase method. RESULTS: Expression of Ck 1, 6, 10, and 16 was stronger in mucositis than in normal mucosa. Ck 7, 8, and 18 were negative for both control and study groups. Ck 5, 13, and 14 were positive for both groups, nevertheless suprabasal staining for Ck 14 was more evident in mucositis than in the control group. Sporadic staining for Ck 19 was observed in 1 case of mucositis and in 2 controls. CONCLUSIONS: Increased Ck expression can be associated with the reactive proliferation of the epithelium and increasing resistance of the oral mucosa during the initial phases of radiotherapy. 相似文献
58.
M Girbau P R González-Guerrero L Bassas F de Pablo 《Molecular and cellular endocrinology》1992,90(1):69-75
The demonstration of growth factor receptors in very young embryos is limited by the difficulty in obtaining sufficient tissue to yield adequate membrane preparations. We have developed an in situ binding technique that allowed quantitation of [125I]insulin and [125I]insulin-like growth factor-I (IGF-I) binding to individual chick embryos. Specific binding per embryo increased from the youngest stage studied (Hamburger and Hamilton (HH) stages 3-4, gastrulating embryo of approximately 18-20 h) until the third day of development. At all ages, the binding of [125I]IGF-I was several fold higher than the binding of [125I]insulin. Autophosphorylation of the beta-subunit of the receptors was stimulated by insulin and IGF-I in a stage- and dose-dependent manner. The two peptides did not have an additive effect. The present studies further support our previous data showing the early developmental appearance of insulin and IGF-I receptors, which very likely are essential for normal embryo development. In addition, this in situ method for demonstration of receptors can be applied to other types of receptors present in isolated organs and young embryos. 相似文献
59.
Bego?a López Arantxa González Ramón Querejeta Mariano Larman Javier Díez 《Journal of the American College of Cardiology》2006,48(1):89-96
OBJECTIVES: We sought to assess the distribution of collagen deposits and collagen degradation in hypertensive patients with either systolic heart failure (SHF) or diastolic heart failure (DHF). BACKGROUND: Increased collagen synthesis and deposition have been described in the myocardium of heart failure (HF) hypertensive patients. METHODS: We studied 39 HF hypertensive patients subdivided into two groups: 16 with SHF and 23 with DHF. Endomyocardial biopsies were performed to quantify mysial (i.e., perimysial plus endomysial) and perivascular and scar-related collagen volume fraction (CVF). Matrix metalloproteinase (MMP)-1 and its tissue inhibitor matrix metalloproteinase (TIMP)-1 were analyzed in cardiac samples by Western blot and immunohistochemistry, and in blood samples by enzyme-linked immunosorbent assay. RESULTS: Mysial CVF was lower in SHF hypertensive patients than in normotensive (p < 0.05) and DHF hypertensive patients (p < 0.01). Perivascular and scar-related CVF was higher (p < 0.05) in the two groups of hypertensive patients than in normotensive subjects, and in SHF hypertensive compared with DHF hypertensive patients. The MMP-1:TIMP-1 ratio was increased (p < 0.05) in tissue and serum samples from the SHF hypertensive group compared with the other two groups of subjects. The MMP-1 expression was increased (p < 0.01) in the interstitium and cardiomyocytes of SHF hypertensive patients compared with DHF hypertensive and normotensive subjects. The serum MMP-1:TIMP-1 ratio was inversely correlated with ejection fraction (r = -0.510, p < 0.001) and directly correlated with left ventricular end-diastolic diameter (r = 0.549, p < 0.001) in all subjects. CONCLUSIONS: These findings show that the pattern of collagen deposits and the balance of the MMP-1/TIMP-1 system are different in the myocardium of SHF and DHF hypertensive patients. It is proposed that excessive degradation of mysial collagen may be related to the compromise of systolic function in HF hypertensive patients. 相似文献
60.