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Biomedical subjects

R Garcia-Rinaldi

Publications and source records attributed to R Garcia-Rinaldi.

52 records · Page 3Linked to original sources

Specific in vitro binding of radiolabeled antibodies to cell surface antigens: interaction of antihuman thymocyte globulin with human target cells.

We have developed a highly sensitive and reproducible in vitro method to measure the rate and amount of binding of radiolabeled antibodies to target cells. We reduced non-specific binding of the antibodies to the target cells approx. 92% by removing protein aggregates from the antibody solutions. Using a specially designed cup that simultaneously allows washing and collection of target cells, cell loss was eliminated. This method was used to study the in vitro binding properties of the IgG fraction of anti-human thymocyte globulin (ATG) to nucleated human cells and to cells of other species. We found the initial rapid uptake of labeled ATG-IgG slowed with prolonged incubation. Incubation temperature and ATG concentration increased the rate of uptake. Sequential absorption studies indicated that initial uptake was due to rapidly binding antibodies. After these antibodies were removed, the rate of binding for antibodies that remained was several fold less than that of the antibodies removed by the initial absorption. Since temperature and the concentration of antibody and target cells can be rigidly controlled, this in vitro model system is ideally suited to quantify optimal conditions and kinetics of antibody binding to cell membrane antigens. Furthermore, the binding properties of antibody subpopulations in an antiserum may be determined by this technique. The maximum antibody binding capacity of various cell types can also be measured using the technique with a precision of +/- 14% on replicate determinations.

Animals

Aneurysm of the main pulmonary artery: long-term survival after aneurysmorrhaphy and closure of a ventricular septal defect.

Pulmonary artery aneurysm (PAA) usually carries an ominous prognosis due to the associated pulmonary hypertension. Six years ago a patient with a PAA secondary to cystic medial necrosis and pulmonary hypertension due to a ventricular septal defect (VSD) was treated by aneurysmorrhaphy and closure of the VSD. Although the patient had early postoperative cardiac failure, his cardiopulmonary status stabilized, and he has done well without recurrence of his aneurysm or cardiac failure. This report summarizes the patient's clinical course, operative treatment, and long-term follow-up.

Adult

Aneurysm of the sinus of Valsalva producing obstruction of the left main coronary artery.

An aneurysm of the left sinus of Valsalva compressed the left main coronary artery and the patient experienced anginal pain. Surgical correction consisted of obliteration of the orifice of the aneurysm, aortic valve replacement, and a saphenous vein bypass from the ascending aorta to the distal left anterior descending coronary artery. Postoperative studies revealed excellent function of the prosthetic valve, no recurrence of the aneurysm and retrograde filling of the left anterior descending and circumflex coronary arteries. Three years after the operation, the patient is asymptomatic.

Angiocardiography

Unimpaired renal, myocardial and neurologic function after cross clamping of the thoracic aorta.

Twelve patients who had sustained trauma presented at the emergency department with either asystole or profound hypotension. All underwent thoracotomy and temporary cross clamping of the descending thoracic aorta as part of the resuscitative measures; all received massive amounts of fluids and cold blood and underwent prompt surgical intervention. In none of these patients was there evidence of myocardial, peripheral nerve, neurologic or renal damage. One patient had residual cortical blindness. Measures were taken to preserve renal function before, during and after aortic cross clamping. These included the avoidance of nephrotoxic antibiotics, limit of clamping time to the minimum effective period, intermittent release of the aortic clamp, and intraoperative administration of osmotic diuretics or furosemide, or both. Other factors which may have contributed to these results were the youth of these patients, the absence of cardiac, renal or metabolic diseases and the hypothermia resulting from the administration of large amounts of cold blood. We concluded that temporary cross clamping of the descending thoracic aorta should be performed only for patients with massive exsanguine trauma who have cardiac arrest or who do not respond to other intensive resuscitative measures.

Adolescent

Surgical management of colon atresia.

Colon atresia is a rare cause of intestinal obstruction in the neonate and requires early diagnosis and prompt surgical treatment. It is impossible in the neonate to differentiate colon atresia from other forms of obstruction at the time of initial presentation. The diagnosis is confirmed roentgenographically, including views of the abdomen and contrast barium enema series. Lesions proximal to the splenic flexure are treated with initial resection of the atretic segment and a primary anastomosis. Those lesions distal to the splentic flexure are managed initally with a diverting loop colostomy with subsequent staged resection and anastomosis.

Colon

Improving the efficiency of wound drainage catheters.

We have modified the most commonly utilized wound drainage system to further reduce the incidence of postoperative accumulation of fluid under the skin flaps. This modification allows more efficient removal of debris, loose tissue fragments, and clots from the wound catheters and insures a constant negative pressure in the system. These maneuvers lengthen the usefulness and improve the efficiency of the catheters and have reduced the incidence of fluid accumulation.

Catheterization

In situ preservation of cadaver kidneys for transplantation: laboratory observations and clinical application.

Many kidneys obtained from cadaver donors undergoing sudden cardiac arrest cannot be transplanted due to the long periods of warm ischemia from the moment of arrest to nephrectomy. A double-ballon-triple-lumen catheter for the rapid in situ preservation of cadaver kidneys has been designed. Used in combination with equipment routinely found in any hospital, it can cool human kidneys in situ to 10-15 C and maintain this temperature until nephrectomy can be performed. Kidenys preserved with this catheter have functioned after transplantation into suitable recipients. This report describes the design and laboratory evaluation of this new device, its clinical effectiveness and technique of insertion.

Adolescent

Upper extremity arteriovenous fistulas for hemodialysis and administration of chemotherapeutic agents.

The arteriovenous fistula (AVF) is the choice made of access to the circulation in patients having chronic hemodialysis. AVFs are also used in patients having repeated courses of intravenous chemotherapy. This relatively simple operation can result in considerable morbidity if improperly done. The technics used in our center, which result in a high patency rate, are described. Maneuvers designed to reduce the resistance to flow and increase the minute flow through the fistulas are stressed.

Animals