Biomedical subjects

F A Weaver

Publications and source records attributed to F A Weaver.

81 records · Page 5Linked to original sources

PubMed1987

Experimental evaluation of a new albumin-impregnated knitted dacron prosthesis.

The performance of a new albumin-impregnated, knitted vascular graft stored damp in saline was assessed by a comparative study in the canine aorta. Knitted grafts interposed into the descending thoracic aorta for 4 weeks included: albumin-coated and stored damp in saline (damp albuminated) (n = 6), albumin-coated and freeze-dried (dry albuminated) (n = 5), collagen-coated (n = 4), and uncoated (n = 4). The results of macroscopic and microscopic evaluation were subjected to one-way analysis of variance (Newman-Keuls). Damp albuminated grafts had significantly less transinterstitial blood loss than uncoated grafts (P less than 0.05). No significant differences in thrombogenicity, thrombus-free surface area, tissue ingrowth, or endothelial coverage existed between the damp albuminated and the uncoated grafts. However, significantly less thrombogenicity (P less than 0.05) and more endothelial cell coverage (P less than 0.05) were present in the damp albuminated grafts than in the collagen-coated grafts. No evidence for delayed graft hemorrhage or distal embolization was found in any group. The new damp albuminated graft is a minimally thrombogenic prosthesis combining low implantation porosity with relative ease of handling. It should function well as a low porosity graft for great vessel replacement.

Animals↗

PubMed1987

Preoperative evaluation of patients with inguinal hernia for colorectal disease.

In retrospective series, 17.0 to 25.5 per cent of those patients with carcinoma of the colon or rectum have been found to have concurrent inguinal herniation. This observation prompted the recommendation that patients with hernias be thoroughly screened for disease of the colon and rectum. That recommendation remains controversial in part because it has not previously been prospectively evaluated. In a one year period, 202 consecutive patients with inguinal hernias completed a preoperative protocol which included: 1, gastrointestinal history; 2, rectal examination; 3, testing of at least two stool specimens with the Hemoccult (Smith Kline Diagnostics) device; 4, sigmoidoscopy, and 5, barium enema. Malignant and premalignant diseases were discovered in five patients, only one of whom had gastrointestinal symptoms. Each malignant lesion was localized (Dukes' A or B) and, therefore, highly curable. Benign disease was found in 49 patients, including polyps in eight and one instance of tight sigmoid stricture. All of the malignant and 91 per cent of the benign lesions were in patients 50 years of age and older. The association between inguinal herniation and colorectal disease was previously attributed to luminal obstruction. In the present series, however, the sole obstructing lesion was a benign stricture. Another explanation for this association must, therefore, be sought. We conclude, on the basis of the results of this experience, however, that screening for pathologic factors of the colon and rectum is warranted in otherwise asymptomatic patients who are more than 50 years old and who present with inguinal hernias.

Adult↗

PubMed1986

Ex vivo renal artery reconstructions: indications and techniques.

Ex vivo renal artery surgery has been reported by several investigators and has extended the role of revascularization in the treatment of lesions previously managed by nephrectomy alone. Several techniques are available for use, and selection of the most appropriate method can be tailored to the specific anatomy being managed. Our total experience included 27 kidneys that have been managed by ex vivo renal artery reconstruction. Lesions managed in this manner include two kidneys with renal artery stenosis and renal tumors, one kidney with a congenital branch arteriovenous malformation, and 24 kidneys with branch occlusive or aneurysmal disease from fibromuscular dysplasia. Postoperative angiography was performed in 22 cases and defined successful revascularization without technical error in 20 cases. One operative death occurred as a result of myocardial infarction. One patient required reoperation to control bleeding, and two patients had temporary acute tubular necrosis during the postoperative period. Techniques employed included ex vivo repair with autotransplantation to the iliac system (six kidneys), mobilization and perfusion without transection of the renal vein (10 kidneys), and ex vivo perfusion and repair with replacement into the original renal fossa (11 kidneys). The authors believe this latter technique of reconstruction to be preferable to autotransplantation for the usual patient undergoing ex vivo repair of complex renovascular lesions.

Adult↗

PubMed1986

Is ileoproctostomy a reasonable procedure after total abdominal colectomy?

A 17-year study has been made of 63 patients who had a variety of colonic disorders treated by total abdominal colectomy with ileorectal anastomosis in four hospitals affiliated with Vanderbilt University. Forty-three of these patients made an uneventful recovery, but 20 others sustained significant complications, nine of which proved to be fatal (hospital mortality rate, 14%). The study shows (and confirms the work of others) that ileorectal anastomosis after total abdominal colectomy is a reasonable procedure that provides satisfactory results on a long-term basis in a majority of patients when strict criteria in patient selection are followed in its application.

Adult↗

PubMed1986

Mycotic embolism and embolomycotic aneurysms. Neglected lessons of the past.

During the past decade, nine patients with bacterial endocarditis have required management of mycotic emboli and/or aneurysms in this center. In these patients, 25 separate mycotic emboli or aneurysms were identified. Among these were four visceral, 11 lower extremity, one aortic, one hypogastric, and eight cerebral lesions. Multiple sites were involved in seven of the nine patients (78%). Presenting symptoms were secondary to acute expansion of mycotic aneurysms in three patients and secondary to rupture of aneurysms in four patients. Mycotic emboli produced cerebral infarction in two patients and acute ischemia in six patients. Asymptomatic mycotic aneurysms of the middle cerebral, hepatic, hypogastric, and profunda femoris arteries and asymptomatic emboli to the profunda femoris and tibial arteries were found during angiographic study. Management included resection alone (7 aneurysms), resection and graft replacement (2 aneurysms and 2 emboli), embolectomy (2), or observation. There was no mortality or loss of limb in these patients. This experience underscores the frequent multiplicity of mycotic emboli and/or aneurysms and stresses the importance of empiric angiographic survey to exclude silent yet potentially lethal visceral and cerebral mycotic foci in patients with bacterial endocarditis and peripheral emboli or aneurysms.

Adult↗

PubMed1984

Combined skeletal and vascular injuries of the lower extremities.

In order to determine the long-term results of surgical treatment in patients with significant combined skeletal and arterial injuries, the authors reviewed the records of those patients treated for this injury between 1970 and 1981, at their institutions. These cases were confined to fractures and/or dislocations of the femur, knee, and tibia which were associated with vascular injuries. Thirty-one patients with 32 injured extremities fit these criteria for our review. The distribution of the orthopedic injuries were as follows: femoral fractures, 16; tibial fractures, 20; and knee dislocations, four. Fifty percent of the injuries had neurologic deficit; significant soft tissue injury was present in 22 extremities; and all but 4 had attempted arterial revascularization. Vascular procedures included saphenous vein by-pass, saphenous vein interposition, end-to-end anastomosis and lateral arteriorrhaphy. Orthopedic repairs were generally accomplished by external means with only five cases treated by immediate internal fixation. Long-term results were categorized as excellent, fair, or poor. Amputations were classified as primary and secondary. Excellent results were found in only five of the reconstructed extremities. Thirty-five percent of the extremities were classified as having a fair result. Two extremities had a poor result. Four extremities were primarily amputated, and secondary amputation was performed on seven extremities. Associated nerve deficits and/or significant soft tissue injuries were found to be the major factors determining the eventual success or failure of reconstructive efforts.

Adolescent↗

PubMed1978

Tissue culture cytotoxicity assay for cyclophosphamide metabolites in rat body fluids.

An in vitro cytotoxicity assay for cyclophosphamide metabolites in rat body fluids is described. Of the two tissue culture tumor cell lines employed, the Walker-256 rat carcinosarcoma was more sensitive to metabolite levels than the L-1210 mouse lymphocytic leukemia. The Walker-256 system detected cyclophosphamide metabolite levels two orders of magnitude lower than the commonly used 4-(p-nitrobenzyl)pyridine analytical procedure.

Animals↗

PubMed1974

An unusual mutant affecting the frequency of organelle mutation.

A mutant of Euglena gracilis Z is described that spontaneously produces irreversibly bleached mutants at a high frequency. Bleaching only occurs during exponential growth under highly aerobic conditions. The kinetics for bleaching and growth of bleached and nonbleached cells suggest that mutation is induced by segregation of a cellular component that becomes limiting after several culture generations. The properties of spontaneous bleaching closely resemble the properties of induced organelle mutagenesis in E. gracilis and yeast.

Aerobiosis↗

PubMedDate not supplied

Upper extremity blood flow in collegiate and high school baseball pitchers A preliminary report.

The arterial and venous volume blood flow in the dominant and nondominant upper extremities of five male pitchers, ages 16 to 21, was measured using color flow duplex ultrasound. Blood-flow measurements were obtained at baseline, after warm-up, and after each sequence of 20 pitches until 100 pitches were thrown. Blood flow was additionally determined 1 hour after the last pitch. The velocity of each pitch was recorded with a speed gun. Anthropomorphic measurements of the upper extremity were obtained at baseline and immediately after Pitch 100 using a standard measuring tape. The highest average arterial volume flow in the pitching arm occurred after 40 pitches, reaching a peak of 549 ml/min (56% increase from baseline). Thereafter, the average arterial blood flow steadily declined, reaching an average of 402 ml/min after the 100th pitch (14% increase from baseline). In contrast, the arterial blood flow in the nonpitching arm increased only slightly from baseline, reaching a maximal volume flow of 448 ml/min immediately after the warm-up period (10% increase from baseline). The volume flow then persistently fell to a level 30% below baseline after the 100th pitch. Although this small pilot study does not demonstrate causation between a decline in pitching performance and arterial blood flow, it suggests arterial flow in the dominant extremity falls as the pitch count increases.

Adolescent↗