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Biomedical subjects

J Hermann

Publications and source records attributed to J Hermann.

At least 145 records · Page 8Linked to original sources
PubMed1979

Loss of the improvement of angina between 1 and 7 years after aortocoronary bypass surgery: correlations with changes in vein grafts and in coronary arteries.

Improvement of effort angina following pure aortocoronary bypass graft surgery was related to postoperative control angiographic studies of grafts and coronary arteries in 75 unselected patients. Clinical and angiographic evaluations were carried out at approximately 1 year and at 5 to 7 years after surgery. At 1 year, 61 (81.3%) were improved (52 without angina and 9 with partial improvement by at least two functional classes), whereas 14 were unimproved (18.7%). At approximately 6 years, loss of improvement (reappearance of angina or aggravation by at least two functional classes) was observed in 22 of the 61 improved patients, representing an attrition of 36.1% over a 5-year period. Graft occlusion or a narrowing of over 50% was observed in two of the 39 patients in whom improvement had continued (5.1%), whereas it was found in six of the 22 patients (27.3%) whose results deteriorated (p less than 0.05). Similarly, progression to occlusion of a preexisting stenosis of over 50% or appearance of a new stenosis of over 50% in a major coronary artery (distal to a graft or in an unbypassed artery) was observed in five of the 39 patients with continued improvement (12.8%) and in 11 of the 22 patients whose condition deteriorated (p less than 0.01). Changes in a graft or in a coronary artery were noted in 63.6% (14/22) of the patients with loss of improvement as compared to only 18% (7/39) of the patients whose improvement did not deteriorate. Improvement of angina was also evaluated in all survivors among our first 500 cases who had preoperative effort angina and pure bypass surgery with or without angiographic studies. Of these 260 patients, 70.4% were angina-free or improved by two to three functional classes at 1 year, and only 41.9% at 7 years after surgery. It is concluded that the effect of aortocoronary bypass graft surgery is transient in a high proportion of patients and that deterioration of results is related to late graft modifications and progression of atherosclerosis, particularly in ungrafted coronary arteries.

Adult↗
PubMed1978

Amino acid sequence of two cyanogen bromide fragments of glycogen phosphorylase.

This communication presents the strategy and experimental details to prove the amino acid sequence of two large fragments of rabbit muscle glycogen phosphorylase generated by cleavage with cyanogen bromide. These fragments, CB18 and CB15, represent 241 of the 841 residues in the whole molecule. In addition to applying methods of automated liquid phase Edman degradation, techniques of selective immobilization and solid phase Edman degradation are used. One of the two cyanogen bromide fragments (CB15) contains two of the sites of cleavage with hydroxylamine which have proved to be important in the overall strategy of determining the complete sequence of this molecule. Together with the accompanying reports by Koide, A., et al., and Titani, K., et al. ((1978) Biochemistry 17 (first and third papers, respectively, in a series in this issue)), the present communication completes the proof of the amino acid sequence of phosphorylase and provides the basis for examining the relationship between its structure and function.

Amino Acid Sequence↗
PubMed1978

Sequence of the carboxyl-terminal 492 residues of rabbit muscle glycogen phosphorylase including the pyridoxal 5'-phosphate binding site.

This communication presents the strategy and experimental details which establish the amino acid sequence of the carboxyl-terminal 492 residues (residues 350 through 841) of rabbit muscle glycogen phosphorylase (EC 2.4.1.1). The heavy segment (Hs), derived from the native enzyme by limited proteolysis with subtilisin, was cleaved with cyanogen bromide to yield 15 fragments. The amino acid sequences of 12 of these are described herein. The sequence of 3 other fragments (CB17C, CB18, and CB15) is described in accompanying reports by Koide, A., et al., and Hermann, j., et al. ((1978) Biochemistry 17 (first and second papers, respectively, in a series in this issue)). These 15 fragments were aligned by analysis of three others generated by cleavage of the heavy segment Hs at asparaginylglycine bonds with hydroxylamine and of four more generated by acid cleavage of aspartylproline bonds. Lysine-679 was identified as the binding site of the essential cofactor pyridoxal 5'-phosphate. These data, together with those reported in the accompanying papers (vide supra), establish the complete sequence of the 841 amino acid residues in glycogen phosphorylase. They provide a chemical basis on which the relationship between structure and function of the enzyme can be examined.

Amino Acid Sequence↗
PubMed1978

Aortocoronary saphenous vein bypass graft changes 5 to 7 years after surgery.

Control angiographic studies were carried out 54 to 88 months after aortocoronary saphenous vein bypass surgery (70 +/- 10 months) in 100 unselected patients who were known to have at least one patent graft 6 to 18 months following the operation. Only 17 of the 159 grafts were found occluded during this interval of 5 years, giving an average yearly attrition rate of 2.1% after the first year. The mean yearly attrition rate was 0.7% in our second series of near consecutive patients operated on after 2 years of experience and modifications of surgical techniques, and it compares favorably with the 2.4% yearly attrition rate found in our first series of patients (P < 0.05). Of the 37 grafts having localized stenoses at 1 year, eight became occluded (21.6%), and four became worse. Grafts with localized stenoses were more prone to late occlusion, whereas no late occlusion was observed in normally appearing grafts at 1 year. Diffuse graft narrowing noted during the first year showed no further change during the subsequent 5 years, and it did not appear to lead to late occlusion. Finally, in 14 grafts, localized narrowing developed after the first year, at a yearly rate of 1.5%. Atherosclerosis appears to be the most likely etiology, being found in two of these instances at reoperation.

Coronary Angiography↗
PubMed1977

Complete amino acid sequence of rabbit muscle glycogen phosphorylase.

The sequence of the 841 amino acid residues in each subunit (molecular weight 97,412) of rabbit muscle glycogen phosphorylase b (1,4-alpha-D-glucan:orthophosphate alpha-glucosyltransferase; EC 2.4.1.1) has been determined. The general strategy was based on limited proteolysis of native phosphorylase b by subtilisin BPN', yielding two large segments (light and heavy) which were fragmented by cleavage at methyonyl-, asparaginyl-glycine, and aspartyl-proline bonds. Analysis of two cyanogen bromide fragments (CB14 and CB17) isolated from the intact molecule yielded the overlap between the light and heavy fragments and the remainder of the sequence. The residues involved in the covalent and allosteric control of the enzyme, and in the binding of the cofactor pyridoxal 5'-phosphate, were identified as serine-14, tyrosine-155, and lysine-679, respectively.

Amino Acid Sequence↗
PubMed1977

Mothers' speech to young children: variation in context.

Recent research has demonstrated the importance of particular features of mothers' speech in influencing the rate of language acquisition in very young children. In the present study of 22 mother-child pairs, the occurrence of these features was examined in samples of mothers' speech to children (aged 18 to 29 months), obtained in unstructured observations in the homes. The features facilitating language acquisition were found to be more frequent in the context of joint attention to pictures or books; speech in other contexts showed social-class differences, with a higher frequency of 'facilitating' features in the speech of middle-class mothers. There was also a tendency for the relative frequency of these features to be positively associated with the children's linguistic ability.

Attention↗