1,721,300 research outputs found
Structural profile of cardiac myxoma
No full textIn the 10-year period 1972-1981, 35 cardiac myxomas from 34 patients were studied. 29 tumors were surgical specimens and 6 were necropsy observations. No patient was under 10 years and only 3 were in the second decade. 25 growths were located in the left atrium, 6 in the right atrium and 2 in the right ventricle; 1 patient presented with myxomas involving both atria. The surface examined in 31 tumors appeared villous in 15, smooth in 13 and slightly irregular in 3. The tumor cells were enmeshed in Alcian blue positive mucoid material and presented as isolated, aggregated in clusters or in small cords, or lining vascular-like spaces. Ultrastructural examination performed in 9 cases disclosed a few features of endothelial cells: microvilli, cell interdigitations, desmosomes and pinocytotic vesicles; cytoplasmic organelles were usually more numerous in the cells arranged in clusters and lining spaces than in those isolated or in small cords; well-developed Golgi complex and endoplasmic reticulum were frequently observed and suggest a secretory function for the myxoma cells. The findings herein reported together with those of recent cytochemical studies support a mesenchymal origin for the myxoma cells with differentiation to endothelial line
Calcification of valve bioprostheses: the cardiac surgeon's nightmare
No full textPericarbon is a last-generation bovine pericardial valve
bioprosthesis, which was designed [I], experimentally
tested [2], and introduced into clinical practice [3] in the
late 1980’s with the aim of overcoming the main drawback
of the Ionescu-Shiley and Vascor Hancock devices,
namely mechanical tearing at the commissural level
even in the absence of calcification [4-61. The early and
medium-term failures observed in these first-generation
pericardial valve bioprostheses were unanimously ascribed
to limitations of valve design and structural properties,
namely poor tissue preservation, the use of the
three-leaflet model requiring excessive stitch anchorage
to the commissure and tissue wear owing to friction between
the leaflet and the Dacron-covered stent. To solve
these problems, a single-cusp pericardial device was designed
by Gabbay, which consisted of a single leaflet of
glutaraldehyde-fixed bovine pericardium mounted on a
flexible Delrin stent, covered by a second pericardial
sheet [7]. The aims were to reduce the number of leaflet
commissures at risk of tearing, to prevent contact between
cloth and tissue, and to obtain the largest possible
orifice area. However, despite this unquestionable rationale
and promising results, both in the experimental
models and initial clinical experience [8], subsequent animal
[9] and clinico-pathological studies [IO] demonstrated
failure of the single-cusp principle: cusp redundancy,
primary commissural tears and dystrophic calcification
occurred early, which suggests that this device is unsuitable
as a cardiac valve substitute.
Alternative solutions designed to prolong mechanical
resistence at the commissures were attempted with the
Carpentier-Edwards and Pericarbon pericardial bioprostheses
[12], which incorporated many improvements. The Pericarbon device is characterized by a single, three-cuspal
shaped pericardium sheet, which is sutured to a second
sheet lining the inner surface of a low-profile,
Dacron-covered Delrin frame. The two pericardial sheets
are cross-sutured internally to the stents. A coating of
hemocompatible Carbotilm covers all the exposed, nonbiological
surfaces. The use of two pericardial sheets
should allow the creation of a linkages chain with
smoothly decreasing elasticity (pericardial leaflet-pericardium
lining-Dacron-Delrin stent), with the aim of
optimizing the stress reduction. Moreover, pericardiumto-
pericardium contact should avoid leaflet abrasion
Achilles' heel of stentless porcine valves
No full textThe Medtronic Freestyle is a stentless porcine valve fixed in glutaraldehyde at zero pressure and treated with α-aminoleic acid, an anticalcification agent probably acting through the mechanism of detoxification. As with other stentless valves, it was introduced to improve hemodynamics in valve replacement for aortic stenosis by reducing the transvalvular gradient and thus favoring regression of left ventricular hypertrophy. This issue of the journal reports a pathological study on nine explant
Anticalcification strategies to increase bioprosthetic valve durability.
No full textIn recent years, there has been a revival in the use of bioprosthetic valves as aortic substitutes. For example, during 2008 in Germany, among 12,397 patients who underwent isolated aortic valve procedures, 78% received a biological prosthesis and 21% a mechanical valve, while only 1% underwent valve repair. However, whilst this situation is the reverse of that during the 1990s, the question must be asked as to whether this is simply a fluctuating fashion, or a reflection of other factors
Successful treatment of cheilitis granulomatosa with intralesional injection of triamcinolone
No full textA 50-year-old male patient presented to us with a permanent swelling of the upper lip, with a slight erythematic aspect, more evident at the right side; on palpation, there was an increased consistency, which felt granulose, and no pain was evoked, and the swelling had begun about 2 years ago
The patient was in very good health, neither facial palsy nor fissurated tongue was present; He did not have any systemic complaints.
He had been treated with oral corticosteroids and anti-histamines for a long time but without success.
We performed a biopsy of the upper lip; the histological and immunofluorescence confirmed the clinical diagnosis of cheilitis granulomatosa (also called Miescher syndrome).
The patients was treated with an intralesional injections of 40 mg of triamcinolone once a week for a total of three administration (Kenacort R, Bristol-Myers Squibb) with modified release associated to lidocaine 2% because the administration is very painful.8 We immediately noticed an improvement with resolution of the symptoms. Follow-up was performed at 1, 3, 6, and 12 months and no recurrence was foun
Mixed gonadal dysgenesis: histological and ultrastructural findings in two cases.
No full textMixed gonadal dysgenesis (MGD) is an intersex genetic abnormality characterized by a streak gonad and a contralateral testis (that is typically cryptorchid) or bilateral streak testes. A uterus and one or both fallopian tubes also may be present. The external genitalia are frequently ambiguous. We studied two phenotypic "females" with MGD. One had a mosaic 45X (40%) and 46XYq (60%) karyotype, a left streak gonad, and a small testis in a right inguinal hernia, whereas the other had a 46XY karyotype, a left streak gonad, and, on the right, a testis with gonadoblastoma. On histological and ultrastructural examination the testis in the first case showed prepubertal tubules lined by a few spermatogonia and immature Sertoli cells with asynchronism in nuclear-cytoplasmic maturation. Ultrastructural examination of the gonadoblastoma in the second case showed neoplastic Sertoli cells. Irregular maturation of Sertoli cells appears to be a feature of MGD. Gonadal extirpation and pathological examination in these cases are important in order to make the correct diagnosis and prevent neoplastic changes
Toronto porcine stentless valve and the need for something more
No full textStentless valves were greeted as a great step forward for
the replacement of diseased aortic valves, particularly aortic
valve s ten osis i n t he e lde rly. In 19 88, Ti rone Da vid
developed a stentless xenograft (Toronto Stentless Porcine
bioprosthesis) aimed to improve hemodynamics, valve
durabi lity, a nd pati ent survi val [1]. This stent less valve
truly resembles a human aortic valve, with cusps, commissures,
and aortic wall posts. The lack of a frame greatly
improves functional performance by diminishing postoperative
transvalvular gradient, thus favoring regression of left
ventricular hypertrophy and enhancing cardiac electrical
stability. Recent study has confirmed that low gradients and
large effective orif ice area are mai ntained at nine years after
implant atio
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