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Biomedical subjects

W C Roberts

Publications and source records attributed to W C Roberts.

At least 19 recordsLinked to original sources

Comparison of modes of death and cardiac necropsy findings in fatal acute myocardial infarction in men and women >75 years of age.

In comparing the cause of death and other cardiac morphologic findings among 60 women and 40 men aged >75 years who died of acute myocardial infarction, we found that women died more often from mechanical complications than left ventricular pump failure. Women had cardiomegaly, nonanterior location of acute myocardial infarction, healed myocardial infarcts, and dilated left ventricular cavity less often than men.

Age Distribution↗

Morphology and significance of the left ventricular collagen network in young patients with hypertrophic cardiomyopathy and sudden cardiac death.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is a primary cardiac disease with a diverse clinical spectrum, in which many of the abnormal structural and pathophysiologic features are consequences of inappropriate left ventricular hypertrophy. METHODS: We analyzed the amount, distribution and structure of the cardiac collagen network in transmural sections of the ventricular septum (thickness 17 to 40 mm, mean 25 mm) in 16 previously asymptomatic children and young adults with HCM (11 to 31 years of age, mean 20 years) who died suddenly. The morphologic appearance and volume fractions of interstitial (matrix) and perivascular (adventitial) collagen were analyzed with polarization microscopy and computerized videodensitometry in picrosirius red-stained sections. Findings were compared with 16 structurally normal hearts, 5 with systemic hypertension and 6 infants who died of HCM. RESULTS: Adults and young children with HCM had an eightfold greater amount of matrix collagen compared with normal controls (14.1 +/- 8.8% vs. 1.8 +/- 1% of the tissue section; p < 0.0001), and a threefold increase compared with patients with systemic hypertension (4.5 +/- 1.3%; p < 0.001) and infants with HCM (4.0 +/- 2.4%; p < 0.001). Compared with normal controls and hypertensives, adults and young children (and infants) with HCM showed increased numbers and thickness of each collagen fiber component of the matrix (perimysial coils, pericellular weaves and struts), which were often arranged in disorganized patterns. In HCM patients, the amount of collagen was not a consequence of other clinical, demographic and morphologic disease variables. CONCLUSIONS: Left ventricular collagen matrix in young, previously asymptomatic patients with HCM who died suddenly is morphologically abnormal and substantially increased in size. The enlarged matrix collagen compartment is present in HCM at an early age, further expands during growth, is partially responsible for increased ventricular septal thickness and likely represents a primary morphologic abnormality in this disease. These findings support the view that the complex HCM disease process is not confined to sarcomere protein abnormalities, but also involves connective tissue elements.

Adolescent↗

Operative therapy of coronary arterial aneurysm.

In summary, a patient with multiple coronary aneurysms and operative therapy is described and 17 previously reported similar cases are reviewed. The proper type of operation for this condition is as yet unclear, but, nevertheless, the reported cases and our case with operative therapy have done well postoperatively despite a variety of procedures performed.

Aged↗

Coronary atherosclerosis: is the process focal or diffuse among patients with symptomatic or fatal myocardial ischemia?

Coronary atherosclerosis among patients with symptomatic or fatal myocardial ischemia is a diffuse and extensive process, and it affects all 4 of the major (right, left main, left anterior descending, and left circumflex) epicardial arteries. Histologic evaluation of 5-mm arterial segments reveals involvement of the entire lengths of the epicardial arteries, although the size of plaque may vary from segment to segment. The dominant component of atherosclerotic plaque among patients with symptomatic or fatal myocardial ischemia is fibrous tissue.

Coronary Artery Disease↗

Comparison of cardiac findings at necropsy in octogenarians, nonagenarians, and centenarians.

Certain clinical and necropsy cardiac findings are described and compared in 391 octogenarians (80%), 93 nonagenarians (19%), and in 6 centenarians (1%). The number of men and women was similar (248 [51%] and 242 [49%]). The cause of death was cardiac in 228 patients (47%), vascular but noncardiac in 71 (14%), and noncardiac and nonvascular in 191 (39%). The frequency of a cardiac condition causing death decreased with increasing age groups (51% vs 32% vs 0), and the frequency of a noncardiac, nonvascular condition causing death increased with increasing age groups (36% vs 47% vs 100%). Among the cardiac conditions causing death, coronary artery disease was found in 62% of cases (141 of 228), aortic valve stenosis in 16% (36 of 228), and cardiac amyloidosis in 10% of cases (22 of 228). Calcific deposits were found at necropsy in the coronary arteries in 81% of the patients (398 of 490), in the aortic valve in 47% (228 of 490), in the mitral annular area in 39% of the patients (190 of 490), and in 1 or both left ventricular papillary muscles in 25% of the patients (122 of 490). The calcific deposits tended to be less frequent in the octogenarians. Three hundred (61%) of the 490 patients had > or = 1 major coronary arteries narrowed > 75% in cross-sectional area by plaque and the percent of patients in each of the 3 age groups and the percent of coronary arteries significantly narrowed in each of the 3 age groups were similar.

Age Factors↗

The heart at necropsy in centenarians.

Cardiac findings at necropsy are described in 6 patients aged 100 to 103 years of age. Although 4 had considerably narrowed coronary arteries at necropsy, none had apparent clinical evidence of myocardial ischemia or congestive heart failure during life.

Aged↗

Comparison of clinical and morphologic cardiac findings in patients having cardiac transplantation for ischemic cardiomyopathy, idiopathic dilated cardiomyopathy, and dilated hypertrophic cardiomyopathy.

This article compares intergroup and intragroup clinical and morphologic findings in patients with ischemic cardiomyopathy (IC), idiopathic dilated cardiomyopathy (IDC), and dilated hypertrophic cardiomyopathy (HC) undergoing cardiac transplantation (CT). Few previous publications have described findings in native hearts explanted at the time of CT. The explanted heart in 92 patients having CT was examined in uniform manner with particular attention to the sizes of the ventricular cavities and the presence of and extent of ventricular scarring. Of the 92 hearts examined, 47 had IC, 35 had IDC, and 10 had dilated HC. Although considerable degrees of intragroup variation occurred, the mean degree of left ventricular dilatation was similar among the patients with IC, IDC, and dilated HC. All patients with IC had left ventricular free wall scarring more extensive than that involving the ventricular septum, but the intragroup variation in the amounts of scarring was considerable. Nine of the 10 patients with dilated HC also had ventricular wall scarring, but it was more extensive in the ventricular septum than in the left ventricular free wall and involvement of the right ventricular wall also was present. Eight (23%) of the 35 IDC patients also had grossly visible ventricular scars but they were small and only 1 of the 8 had coronary narrowing and that was not in the distribution of the scarring. Narrowing of 1 or more epicardial coronary arteries >75% in cross-sectional area by plaque was present in all 47 IC patients, in 8 of the 35 IDC patients (7 had no ventricular scars), and in none of the 10 dilated HC patients. Coronary angiography was the major clinical tool allowing separation of the IC, IDC, and HC patients. Coronary angiography did not detect narrowing in any of the 8 patients with IDC who were found to have coronary narrowing on anatomic study. Thus, among patients with IC, IDC, and dilated HC having CT, distinctive anatomic features allow separation of patients with IC, IDC, and dilated HC, but within each group considerable variation in left ventricular cavity size and extent of ventricular scarring occurs.

Adult↗

Molecular analysis of sequence heterogeneity among genes encoding decorin binding proteins A and B of Borrelia burgdorferi sensu lato.

Immunization of mice with Borrelia burgdorferi decorin binding protein A (DbpA), one of two gene products of the dbpBA locus, has been shown recently to confer protection against challenge. Hyperimmune DbpA antiserum killed a large number of B. burgdorferi sensu lato isolates of diverse phylogeny and origin, suggesting conservation of the protective epitope(s). In order to evaluate the heterogeneity of DbpA and DbpB and to facilitate defining the conserved epitope(s) of these antigens, the sequences of the dbpA genes from 29 B. burgdorferi sensu lato isolates and of the dbpB genes from 15 B. burgdorferi sensu lato isolates were determined. The predicted DbpA sequences were fairly heterogeneous among the isolates (58.3 to 100% similarity), but DbpA sequences with the highest similarity tended to group into species previously defined by well-characterized chromosomal markers. In contrast, the predicted DbpB sequences were highly conserved (96.3 to 100% similarity). Substantial diversity in DbpA sequence was seen among isolates previously shown to be killed by antiserum against a single DbpA, suggesting that one or more conserved protective epitopes are composed of noncontiguous amino acids. The observation of individual dbpA alleles with sequence elements characteristic of more than one B. burgdorferi sensu lato species was consistent with a role for genetic recombination in the generation of dbpA diversity.

Adhesins, Bacterial↗