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21.
Amino acid analysis by dinitrophenylation and reverse-phase high-pressure liquid chromatography 总被引:1,自引:0,他引:1
The determination of amino acids has been achieved by reverse-phase high-pressure liquid chromatography of their dinitrophenyl derivatives. The methods developed permit the quantitation of all amino acids commonly encountered in a protein hydrolysate and the effect of various parameters on this separation was systematically evaluated. The procedure eliminates the need for specialized postcolumn equipment as employed in conventional amino acid analysis and can be obtained by a simple gradient high-pressure chromatograph. The sensitivity obtained is comparable to that available by methods in common usage, being able to determine amino acids quantitatively in the low picomole range. 相似文献
22.
23.
Retroperitoneal fibromatosis and acquired immunodeficiency syndrome in macaques: clinical and immunologic studies 总被引:5,自引:0,他引:5
C C Tsai W E Giddens H D Ochs W R Morton G H Knitter G A Blakley R E Benveniste 《Laboratory animal science》1986,36(2):119-125
A simian acquired immunodeficiency syndrome (SAIDS) associated with retroperitoneal fibromatosis (RF) has been observed in several species of macaque at the Washington Regional Primate Research Center. Clinical signs were recurrent diarrhea, weight loss, mesenteric lymphadenopathy, and opportunistic infections. Most affected macaques in the later stages of illness showed marked immunodeficiency. Response of peripheral blood mononuclear cells to mitogens was impaired significantly. There was sharply depressed primary and secondary antibody response to the T-cell dependent antigen, bacteriophage phi X174. Affected monkeys did not switch from IgM to IgG antibody following a secondary immunization, as did normal macaques. Twenty-four (67%) of 36 affected animals with progressive RF or deteriorated stages of illness had hypoproteinemia and hypoalbuminemia. Quantitative serum immunoglobulins of 23 cases showed that eight (35%) had hypogammaglobulinemia, six (26%) had hypergammaglobulinemia, and the remainder (39%) were within the normal range. Opportunistic infections were predominantly bacterial pathogens. Type D retrovirus appeared to be closely associated with RF-affected macaques (12/12 or 100%). The case fatality rate (including animals sacrificed after prolonged illness) was 98%. The leading cause of death was due directly to RF lesions in 43%, to enterocolitis in 36%, septicemia in 12%, amyloidosis in 5%, and malignant lymphoma (2%). Clinical, immunologic and pathologic changes reveal an acquired immunodeficiency syndrome that has many similarities to human AIDS. SAIDS and RF may be a useful model for studying human AIDS. 相似文献
24.
Further segregation analysis of the fragile X syndrome with special reference to transmitting males 总被引:45,自引:0,他引:45
S. L. Sherman P. A. Jacobs N. E. Morton U. Froster-Iskenius P. N. Howard-Peebles K. B. Nielsen M. W. Partington G. R. Sutherland G. Turner M. Watson 《Human genetics》1985,69(4):289-299
Summary A new series of 96 pedigrees with the fra(X) syndrome was analysed using complex segregation analysis with pointers, defining affection as any degree of mental impairment. These families were found to exhibit the same segregation pattern as the first series of 110 pedigrees (Sherman et al. 1984). The best estimate for penetrance of mental impairment in males was 79% and in females was 35% for the combined data. Again, there was little evidence for sporadic cases among affected males.Many more intellectually normal transmitting males have been observed since the existence of such males and the concomitant need to investigate the paternal side of pedigrees was recognized. On further investigation of all 206 pedigrees from the old and new data sets, the sibships of nonexpressing males appeared to be different from those of expressing males. Our analysis, using mental impairment as the phenotype, suggested that obligate carrier mothers and daughters of intellectually normal transmitting males are rarely, if ever, mentally impaired and that the sibs of transmitting males are much less likely to be retarded than the sibs of mentally impaired males. Though mothers and daughters of transmitting males are similar in phenotype, the expression of the gene in their offspring appears to be different: the penetrance of mental impairment is higher in offspring of intellectually normal daughters of transmitting males than in offspring of intellectually normal mothers of transmitting males. The implications of these observations for genetic counseling and for genetic models of the fra(X) syndrome are discussed. 相似文献
25.
Multilocus recombination frequencies 总被引:8,自引:0,他引:8
26.
Chromosome number determinations were made from 407 wild or transplanted individuals and seedlings representing 65 taxa and hybrids inEuthamia andSolidago. The following are first reports:Euthamia remota, 2n=9II;Solidago leavenworthii, 2n=54;S. mollis, 2n=36;S. mollis var.angustata, 2n=36;S. rigida var.glabrata, 2n=9II;S. sempervirens var.azorica, 2n=9II; andS. sparsiflora, 2n=54. Most species have been sampled only a few times or are consistently of one cytotype. Sufficient counts have been made to indicate some general patterns of cytotype distribution in the following species complexes:S. gigantea, S. canadensis, S. flexicaulis, S. rugosa, andS. uliginosa. 相似文献
27.
Metabolism of leukotriene A4 by human erythrocytes. A novel cellular source of leukotriene B4 总被引:6,自引:0,他引:6
F Fitzpatrick W Liggett J McGee S Bunting D Morton B Samuelsson 《The Journal of biological chemistry》1984,259(18):11403-11407
Human erythrocytes transformed leukotriene A4 into leukotriene B4. Metabolism was proportional to the erythrocyte concentration, even at subphysiological levels (0.08-4 X 10(9) erythrocytes/ml). Comparative metabolic studies excluded the possibility that leukotriene B4 originated from trace amounts of polymorphonuclear leukocytes or platelets present in the purified erythrocyte suspensions. For example, suspensions of isolated platelets (100-500 X 10(6) cells/ml) failed to convert leukotriene A4 into leukotriene B4; and conversion by suspensions of isolated polymorphonuclear neutrophils was insufficient to account for the amounts of leukotriene B4 formed by erythrocytes. Leukotriene B4 formation was maximal within 2 min and substrate concentration dependent. Enzymatic activity originated from a 56 degrees C labile nondialyzable (Mr greater than 30,000) soluble component in the 100,000 X g supernatant obtained from lysed erythrocytes. In contrast to the contemporary view, our results indicate that human erythrocytes are not metabolically inert in terms of eicosanoid biosynthesis. The role of human erythrocytes during inflammatory or pulmonary disorders deserves re-examination in this context. 相似文献
28.
Right ventricular function was investigated in seven fetal sheep (125-130 days gestation) hypoxaemic at a mean of 5 days postoperation, and were compared to nine normoxaemic fetal sheep of the same gestation. Arterial O2 and CO2 tensions, pH, and haematocrit values for the hypoxaemic and normoxaemic fetuses were 15.6 +/- 1.0 vs. 20.6 +/- 1.8 torr, 49.4 +/- 4.1 vs. 46.1 +/- 1.6 torr, 7.38 +/- 0.02 vs. 7.39 +/- 0.02, and 29 +/- 7.5 vs. 31 +/- 5.3%, respectively. Right ventricular output and stroke volume were similar in the two groups, 241 +/- 57 vs. 247 +/- 75 ml X min-1 X kg-1 and 1.5 +/- 0.4 vs. 1.5 +/- 0.4 ml X kg-1, respectively. Filling and afterload pressures were also similar in the hypoxaemic and normoxaemic fetuses with right atrial pressure of 3.0 +/- 1.0 vs. 3.7 +/- 1.2 mmHg, and arterial pressure of 42 +/- 5 vs. 43 +/- 4 mmHg, respectively. Ventricular function curves were produced by rapid withdrawal and re-infusion of fetal blood producing curves with a steep ascending limb and a plateau phase. The breakpoint joining the limbs of the control function curve for the hypoxaemic and normoxaemic fetuses were right atrial pressure 2.9 +/- 1.0 vs. 3.4 +/- 1.2 mmHg and a stroke volume of 1.5 +/- 0.5 vs. 1.5 +/- 0.4 ml X kg-1, respectively. Linear regression of stroke volume against arterial pressure from 30-90 mmHg during infusions of nitroprusside and phenylephrine at right atrial filling pressures greater than breakpoint was stroke volume = 0.018 ml X kg-1 X mmHg-1 arterial pressure +/- 2.25 ml X kg-1. This equation is not different from that calculated in normoxaemic fetuses, and demonstrates that the fetal right ventricle is quite sensitive to changes in arterial pressure. These data indicate that reduction in fetal oxygen content by an estimated 40% does not affect fetal right ventricular function. 相似文献
29.
The genes coding for insulin-like growth factors I and II and epidermal growth factor have been localized to human chromosomes 12q22----q24.1, 11p15, and 4q25----q27, respectively. 相似文献
30.
Complete nucleotide and derived amino acid sequence of cDNA encoding the mitochondrial uncoupling protein of rat brown adipose tissue: lack of a mitochondrial targeting presequence. 总被引:7,自引:0,他引:7 下载免费PDF全文
R G Ridley H V Patel G E Gerber R C Morton K B Freeman 《Nucleic acids research》1986,14(10):4025-4035
A cDNA clone spanning the entire amino acid sequence of the nuclear-encoded uncoupling protein of rat brown adipose tissue mitochondria has been isolated and sequenced. With the exception of the N-terminal methionine the deduced N-terminus of the newly synthesized uncoupling protein is identical to the N-terminal 30 amino acids of the native uncoupling protein as determined by protein sequencing. This proves that the protein contains no N-terminal mitochondrial targeting prepiece and that a targeting region must reside within the amino acid sequence of the mature protein. 相似文献