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Biomedical subjects

G Velasquez

Publications and source records attributed to G Velasquez.

35 records · Page 2Linked to original sources
PubMed1980

Noninvasive localization of the aortic arch in infants with tracheoesophageal fistula: an experimental study.

For surgical treatment of patients with tracheoesophageal fistulas the localization of the aortic arch is great practical importance. Aortography and CT scanning have been advocated as the radiographic techniques of choice. The location of the aortic arch can be diagnosed on a chest x-ray by the deviation of the trachea alone. A barium swallow is not required. The optimal radiographic technique for this purpose was investigated in phantom studies and tested in animals and newborns. It is proposed that in addition to the standard chest x-ray a high kvp film with hardened beam (1 mm copper -- 1 mm aluminum) be added in order to demonstrate the tracheal deviation. The additional x-ray exposure to the infant is negligible; and the technique is simple, reliable, and noninvasive.

Animals↗
PubMed1980

An unusual aberrant left subclavian artery.

In a child with tetraology of Fallot, pulmonary atresia, and right aortic arch, the left subclavian artery arose from an unusually low position, and was initially misinterpreted as a systemic pulmonary collateral. This anomaly probably resulted from a "lag" in embryological migration of the left subclavian artery onto the aortic arch.

Abnormalities, Multiple↗
PubMed1980

Cystic arterial adventitial degeneration.

Cystic degeneration of the adventitia is a rare entity occurring most commonly in the popliteal artery: only a few cases involving the external iliac, femoral, radial, and ulnar arteries have been reported. The authors describe 2 cases, one of which appears to be the first report of the disease in the external iliac artery in a child.

Adolescent↗
PubMed1980

Nonsurgical aortoplasty in Leriche syndrome.

The abdominal aorta was dilated with a pair of 9-mm balloon catheters in a patient with Leriche syndrome. The bilateral pressure gradient, initially 60 mm Hg, disappeared even after papaverine was injected. Balloon dilatation of the abdominal aorta may be an effective, safe nonsurgical technique, particularly in localized, noncalcified atheromata, and does not carry the risk of impotence seen with surgical endarterectomy or bypass.

Aorta, Abdominal↗
PubMed1980

The angiographic appearance of intrarenal leiomyoma.

Two benign leiomyomas are described together with their radiographic and sonographic appearance, and the literature is reviewed. In large, asymptomatic renal masses, which are well circumscribed on angiography, a benign intrarenal leiomyoma may be considered. Nonechogenicity and relatively good through-transmission seem to substantiate the diagnosis.

Angiography↗
PubMed1979

Coarctation of the abdominal aorta.

Coarctation of the abdominal aorta is an uncommon process but an important cause of systemic hypertension. Angiography is the investigation of choice to establish a diagnosis and document the extent of involvement. However, angiography does not provide an etiological diagnosis; and it may not be possible to distinguish an acquired coarctation from a congenital process. Three patients with coarctation of the abdominal aorta are presented.

Adolescent↗
PubMed1979

Primary liver tumors in the pediatric age group: an angiographic challenge.

Eleven children, ranging in age from three months to fifteen years, with primary liver tumors were examined by large volume direct magnification arteriography (2.5--3 ml of contrast material per 1 kg body weight for a single selective study). The following tumors were found: hepatoblastoma (1), hepatocellular carcinoma of the adult type, hepatoma (3), infantile hemangioendothelioma (4), hemangiosarcoma (1), focal nodular hyperplasia (1) and cystic mesenchymal hamartoma (1). Some of the tumors have a quite typical angiographic appearance as infantile hemangioendothelioma, hemangiosarcoma, cystic mesenchymal hamartoma. The other highly vascular neoplasms show unspecific signs of vascular malignant tumors; subtile angiographic signs may, however, be present and help in the differential diagnosis.

Adolescent↗
PubMed1979

Doming of the pulmonary valve after valvotomy.

Doming of the pulmonary valve is considered an important angiographic sign for valvar stenosis. But, this sign cannot be used with similar specificity following valvotomy because at the time of surgery a bicuspid valve is created. Pre- and postoperative hemodynamic data and right ventriculograms are reviewed in 22 patients with simple pulmonary valvar stenosis. There was no correlation between the transvalvar gradient and appearance of the pulmonary valve after surgery.

Angiocardiography↗
PubMed1979

Radiological evaluation of composite aortic grafts.

Aneurysm of the ascending aorta with aortic regurgitation is most commonly caused by cystic medial necrosis. Replacement of the aortic valve and diseased aorta with a composite graft and re-implantation of coronary arteries is the surgical treatment of choice at the authors' institution. The most important late complication of this procedure is hemorrhage at the anastomotic sites. Radiology plays an important role in the management of these patients. The angiographic appearance of cystic medial necrosis and the radiological features and postoperative complications of composite grafts in 15 patients are described.

Adolescent↗
PubMed1979

The "ring sign" of necrotic pheochromocytoma.

Pheochromocytomas are usually hypervascular tumors exhibiting dense stain during angiography. The cystic nature of the neoplasm or tumor necrosis can result in failure of opacification of the mass or a central lucent area. Four cases of pheochromocytoma are described where a central avascular zone was surrounded by a dense rim of contrast, giving a "ring sign." Since this appearance is best seen in the capillary and venous phases, delayed films are essential.

Adolescent↗
PubMed1979

Therapeutic embolization of facial arteriovenous fistulae.

Two cases of percutaneous transfemoral embolization of facial hemangiomas and arteriovenous (AV) malformations are reported. In both cases, Ivalon shavings were injected through a percutaneously placed catheter to permanently occlude peripheral feeders of the AV malformation. In one case, because of the size of the large venous sacs associated with the malformation, a steel coil was introduced to form a baffle, over which several additional strands of surgical silk were introduced to obliterate these sacs. These cases emphasize the need for embolization of small feeding arteries to prevent recurrence by collateral channels. To achieve this, specific-sized emboli are necessary; Ivalon is a suitable embolic material.

Adult↗
PubMed1979

An essential view in coronary arteriography.

A significant stenosis of the left main coronary artery is associated with a significant mortality and is one of the major indications for aortocoronary bypass surgery. The diagnosis of this lesion on clinical grounds is inconsistent and should be established by angiography. All routine projections during coronary arteriography cause foreshortening of the left main coronary artery. Well-collimated anteroposterior and shallow right and left anterior oblique views show the main segment best. These views also show the proximal segments of circumflex and anterior descending branches, and should be routinely used during every coronary arteriogram.

Coronary Angiography↗
PubMedDate not supplied

Short course albendazole treatment for neurocysticercosis in Columbia.

The efficacy of albendazole was evaluated in 20 Colombian patients with neurocysticercosis showing neurological symptoms. All had parenchymal non-enhancing cystic images by computerized tomography and a positive enzyme-linked immunosorbent assay for cysticercus antibodies in serum or cerebrospinal fluid. They stayed in hospital for 8 d during treatment with albendazole, 15 mg/kg/d in 2 divided doses, and were then followed for at least 6 months after treatment. The number of cysts was reduced by 50% after 6 months. In 7 (35%) all cysts disappeared, in 7 (35%) the number was reduced, and in the remaining 6 (30%) the number was unchanged. In the 13 patients who still had cysts at 6 months, 11 showed a moderate decrease in average cyst size and in 2 the size was unchanged. Side effects during treatment were observed in 60% of the cases, but only 3 required corticosteroids.

Adolescent↗
PubMedDate not supplied

Hyperprolactinaemia and hyperserotoninaemia: their relationship to seminal quality.

Seminal quality and levels of blood serotonin (5-HT) and serum prolactin (PRL) were determined in 60 men attending an infertility service. Subjects were grouped according to normal or abnormal accessory sex gland function. Subjects with normal accessory sex gland function were further subdivided into groups with asthenozoospermia, polyzoospermia, normozoospermia, oligozoospermia, or azoospermia. Blood 5-HT levels were significantly higher in oligozoospermics (115.9 +/- 23.7 ng ml-1, P less than 0.05), and asthenozoospermics (90.0 +/- 8.2 ng ml-1, P less than 0.05), than in normals (68.5 +/- 5.3 ng ml-1), whereas serum PRL levels were higher in azoospermics (44.2 +/- 4.7 ng ml-1) than in normozoospermics (15.9 +/- 1.6 ng ml-1, P less than 0.01). Subjects with abnormal accessory sex gland function were also subdivided according sperm count and sperm motility categories. None of these subgroups showed differences in serum PRL levels or blood 5-HT levels. Men with hyperserotoninaemia had higher serum PRL levels, low sperm count, and low motile sperm concentration. Moreover, higher 5-HT levels may be observed in men with normal PRL levels and also associated with normal PRL levels and with hyperprolactinaemia, and hyperprolactinaemia may be observed also associated with normal serotonin levels. Hyperserotoninaemia was related to both diminished sperm count and sperm motility, whereas hyperprolactinaemia was related to low sperm count. When hyperprolactinaemia and hyperserotoninaemia were both present, additive effects were observed.

Adult↗
PubMedDate not supplied

Evolution of sensitivity to hymenoptera venoms during maintenance immunotherapy.

Duration of venom immunotherapy still remains questionable since some patients lose their sensitivity. Venom immunotherapy can be stopped when venom skin tests and specific IgE are negative. Five studies have been performed to prospectively study the evolution of skin tests and specific IgE after three to six years of maintenance immunotherapy. Four studies showed that skin tests became negative in 30 to 55% of patients depending upon the venom species and the duration of the treatment. Mean specific IgE declined in most studies but were negative only in a substantial number of patients in the European studies. Adults and children had a similar rate of disappearance of skin test reactivity. In one study, skin tests were negative in 1/3 of patients after one year of treatment suggesting that venom immunotherapy may be given for a short period of time in some patients.

Adolescent↗