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Biomedical subjects

D C Morris

Publications and source records attributed to D C Morris.

At least 145 records · Page 8Linked to original sources
PubMed1977

Echocardiographic manifestations of flail aortic valve leaflets.

Six patients with aortic regurgitation secondary to flail aortic valve leaflet syndrome were studied echocardiographically, angiographically, surgically, and pathologically. The etiology of flail aortic leaflet was myxomatous degeneration in four patients and bacterial endocarditis in two. The echocardiographic manifestations of flail aortic valve leaflet are diastolic fluttering of the aortic cusp echoes, abnormal systolic aortic leaflet movement, and abnormal diastolic fluttering echoes in the left ventricular outflow tract. Diastolic fluttering of the aortic valve leaflets is specific echocardiographic evidence of aortic regurgitation due to flail aortic leaflets, and demonstration of diastolic fluttering of the aortic leaflets and diastolic fluttering echoes in the left ventricular outflow tracts is direct evidence of flail and prolapsed aortic leaflets.

Adult↗
PubMed1977

Sterol content and polyene antibiotic resistance in isolates of Candida krusei, Candida parakrusei, and Candida tropicalis.

Three isolates, one from each species of Candida krusei, C. parakrusei, and C. tropicalis, obtained from infected patients, were more tolerant of significantly higher concentrations of polyene antibiotics than the corresponding reference wild types. The resistant strains isolated had the same sterols as their wild-type counterparts but in lower concentrations.

Amphotericin B↗
PubMed1977

Eburicol, lichesterol, ergosterol, and obtusifoliol from polyene antibiotic-resistant mutants of Candida albicans.

Two classes of polyene-resistant mutants were isolated from survivors of N-methyl-N'-nitro-N-nitrosoguanidine treatment of a wild-type Candida albicans. An analysis of the major sterols of one class revealed an accumulation of lichesterol and fecosterol while the other class accumulated eburicol, obtusifoliol, and lanosterol with minor quantities of C28 sterols.

Amphotericin B↗
PubMed1977

Hemodynamic results of aortic valvular replacement with the porcine xenograft valve.

Twenty-three patients were evaluated by cardiac catheterization two to 12 months following aortic valve replacement with the porcine xenograft valve. These hemodynamic studies established a mean peak-to-peak systolic gradient across the prosthesis of 23 mm Hg with a range of 6-58 mm Hg. The mean effective orifice area was calculated to be 1.25 cm2. The effective orifice area increased with increasing valve size from 0.99 cm2 for the 19 mm prosthesis to 1.44 cm2 for the 25 mm prosthesis. While in general the hemodynamics of the porcine xenograft valve are comparable to other available prostheses, the exceedingly small orifice areas (0.99 cm2 and 1.03 cm2) calculated for the 19 mm and 21 mm prostheses render their use inadvisable.

Adult↗
PubMed1976

Myocardial infarction in young women.

This study of 24 women under age 40 years with myocardial infarction demonstrates that even in young women myocardial infarction is most commonly due to coronary atherosclerotic heart disease. Other causes of coronary occlusion were documented in 17% of these patients, indicating that these lesser causes of myocardial infarction are more common in young women than in older persons or in young men. In those patients with coronary atherosclerosis one or more significant risk factors could usually, but not always, be documented. The clinical manifestation of the coronary occlusion in the study group was not unlike its manifestation in groups of different ages or sex, or both.

Adolescent↗
PubMed1975

Echocardiographic diagnosis of tetralogy of Fallot.

The echocardiographic features of tetralogy of Fallot were defined in 25 patients with this malformation proved by cardiac catheterization. The echocardiographic characteristic that was present in all patients and that was most sensitive was the abrupt ending of the interventricular septal echoes with the aorta overriding the ventricular septal defect. The following additional echocardiographic features were frequently demonstrated in these 25 patients: right ventricular enlargement (20 patients), hypertrophy of the interventricular septum (20 patients), diminution of the right ventricular outflow tract (21 patients) and widening of the aorta (24 patients). The suggestion is made that the most specific echocardiographic pattern of tetralogy of Fallot is the finding of several echocardiographic abnormalities rather than the single feature of aortic overriding. Recognition of the altered anatomic relation coupled with a complete echocardiographic evaluation of all cardiac structures is a reliable means of diagnosing tetralogy of Fallot.

Adolescent↗
PubMedDate not supplied

Transfemoral liver biopsy by forceps: a review of 104 consecutive procedures.

PURPOSE: Transvenous liver biopsy is performed on patients with contraindications to percutaneous biopsy. Transfemoral liver biopsy has not been widely reported, and we present our experience of 104 consecutive procedures. METHODS: During a 30-month period, 88 patients underwent 104 transfemoral liver biopsies. Under fluoroscopic guidance a 9 Fr curved introducer catheter is passed into the right hepatic vein via a standard femoral sheath. A 7 Fr biopsy forceps is then passed into the liver, opened and wedged. Prior to biopsy, the image intensifer is rotated so the relation of the capsular surface to the biopsy site is verified and capsular perforation avoided. RESULTS: Tissue samples obtained in 97 of 104 procedures (93%) were adequate for diagnosis in 83 (80%). Complications occurred in six procedures (6%) including two capsular perforations; the latter two were treated by coil embolization. CONCLUSION: We found transfemoral liver biopsy using forceps to be a safe, well-tolerated procedure with a high diagnostic yield and it is a technically easy alternative to the transjugular approach using large needles.

Adolescent↗
PubMedDate not supplied

Calcification of cartilage matrix in chondrocyte cultures derived from rachitic rat growth plate cartilage.

Chondrocytes obtained from collagenase-digested epiphyseal growth plate cartilage of rachitic rats were grown in multilayer cultures. The cultured chondrocytes produced a metachromatic matrix and further electron microscopic examination revealed typical features of cartilage matrix collagen fibrils and matrix vesicles. The alkaline phosphatase activity in cultures was high during the entire 3-week culture period. Acid phosphatase showed a marked increase in activity during the first week of culture. The appearance of apatite crystals in the synthesized matrix was monitored by electron microscopy over a 3-week period. First crystals were consistently found to be associated with matrix vesicles, and in the older cultures calcification spread into the surrounding matrix. No collagen fibrils associated with mineralization were observed during the early culture period. This study clearly demonstrates that in chondrocyte cultures the first mineral crystals were found within or in close association with matrix vesicles. This gives further support to the hypothesis that matrix vesicles are the primary site of mineralization in cartilage. In addition to calcification studies it is suggested that this model is suitable for studying the effects of hormones or other agents on rachitic chondrocytes in vitro.

Animals↗
PubMedDate not supplied

Matrix vesicle calcification in rat epiphyseal growth plate cartilage prepared anhydrously for electron microscopy.

The preparation of mineralizing tissues for electron microscopy by methods that involve the use of aqueous solvents may result in translocation and/or removal of mineral, leading to the possible erroneous interpretation of initial calcifying loci. The failure of a recent cryoultramicrotomy study to detect a mineral phase associated with matrix vesicles raised doubts about the role of the matrix vesicle in initial mineralization and prompted us to reexamine the ultrastructure of calcifying cartilage using three different anhydrous preparatory techniques. Matrix vesicles or structures similar in profile and location were identified in rat epiphyseal growth plate cartilages that had been subjected to freeze-substitution, cryoultramicrotomy, or ethylene glycol fixation. Furthermore, mineral deposits, as confirmed by energy dispersive x-ray analysis, were observed within or in close association with the matrix vesicles in the extracellular matrix of the growth plate cartilage by all three methods. No evidence of mineral deposition at other sites preceding matrix vesicle calcification was found. Our studies support the conclusion of many investigations that matrix vesicles are the initial site of growth plate calcification.

Animals↗
PubMedDate not supplied

Clinical experience with Hexabrix in cerebral angiography.

Sixty patients from the University of British Columbia, Vancouver General Hospital, and University of Alberta Hospitals Edmonton participated in an open-labelled clinical study on the safety, tolerability and efficacy of ioxaglic acid (Hexabrix) in cerebral angiography. Only 4% of patients experienced significant pain during carotid and brachiocephalic injections of Hexabrix. No increased incidence of side effects or adverse effects were encountered. In addition, radiographic film quality overall was excellent and comparable to that obtained using conventional contrast agents. Hexabrix is a safe and effective contrast agent for cerebral angiography.

Adolescent↗
PubMedDate not supplied

Spontaneous hemorrhage in the medulla oblongata: clinical MR correlations.

A 72-year-old woman with a history of hypertension developed a tegmental medullary syndrome secondary to a spontaneous hemorrhage in the medulla oblongata. A CT examination was diagnostic of the bleeding. However, a magnetic resonance study carried out on the 4th day after the event gave more precise information about the location and extent of the lesion, thus permitting a better correlation with the neurological findings.

Aged↗
PubMedDate not supplied

Risk factors, angiographic patterns, and outcomes in patients with ventricular septal defect complicating acute myocardial infarction. GUSTO-I (Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries) Trial Investigators.

BACKGROUND: Ventricular septal defect (VSD) complicating acute myocardial infarction has been studied primarily in small, prethrombolytic-era trials. Our goal was to determine clinical predictors and angiographic and clinical outcomes of this complication in the thrombolytic era. METHODS AND RESULTS: We compared enrollment characteristics, angiographic patterns, and outcomes (30-day and 1-year mortality) of patients enrolled in the Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries (GUSTO-I) trial with and without a confirmed diagnosis of VSD. Univariable and multivariable analyses were used to assess relations between enrollment factors and the development of VSD. In all, 84 of the 41 021 patients (0.2%) developed VSD, a smaller percentage than reported in the prethrombolytic era. The median time from symptom onset to VSD diagnosis was 1 day. Enrollment factors most associated with this complication were advanced age, anterior infarction, female sex, and no previous smoking. The infarct artery was more often the left anterior descending and more likely to be totally occluded in patients who developed VSD. Mortality at 30 days was higher in patients with VSDs than in those without this complication (73.8% versus 6.8%, P<0.001). Patients with VSDs selected for surgical repair (n=34) had better outcomes than patients treated medically (n=35; 30-day mortality, 47% versus 94%). CONCLUSIONS: Compared with historical control subjects, patients who undergo thrombolysis within 6 hours of infarction onset may have a reduced risk of later VSD. If patients develop this mechanical complication, however, it typically occurs sooner than described in the prethrombolytic era. Despite improvements in medical therapy and percutaneous and surgical techniques, mortality with this complication remains extremely high.

Age Factors↗
PubMedDate not supplied

Epidemiological abuse.

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Family Practice↗