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Biomedical subjects

R Llull

Publications and source records attributed to R Llull.

At least 19 recordsLinked to original sources

A novel device for the simple and efficient refinement of liposuctioned tissue.

In short, our device allows a surgeon who is harvesting adipose tissue for autologous fat transplantation to immediately, easily, efficiently, and sterilely isolate adipose tissue from the unwanted waste components that are associated with primary liposuction effluent. It does so by "trapping" the fat tissue contained within raw liposuction effluent. Once the tissue fraction has been separated, the device design then allows for direct implantation or subsequent washing/rinsing of the tissue with saline/buffer of choice in preparation for tissue reimplantation.

Adipose Tissue↗

Revascularization of the upper extremity in a preterm infant: a case report and review of the literature.

Upper extremity arterial injuries in preterm infants are usually of iatrogenic origin. Current microsurgical techniques permit extremity revascularization in these patients. The authors report the microsurgical repair of a 0.7-mm brachial artery in a 940-g preterm infant. The preterm infant warrants special consideration due to physiological immaturity. Rapid fluid shifts, a relative polycythemia, and the potential for low cardiac output states increase the risk for vascular thrombosis. Systemic heparinization is contraindicated in this population due to the risk of intraventricular hemorrhage. Optimization of various physiological variables should reduce the risk of thrombosis.

Anticoagulants↗

Computer-assisted anthropometry for outcome assessment of cleft lip.

Anthropometry and clinical examination best evaluate the morphology of repaired cleft lip and nose. An original, accurate, and practical image analysis of the lip and nose, which takes advantage of the mathematic, geometric, and organizational capabilities of public domain NIH-Image software (http://rsb.info.nih.gov/nih-image/), has been developed and tested over the past 6 years. A modified structured physical examination form that complements this analysis is under study. Accuracy of NIH-Image-based anthropometry was compared with direct measurements of 22 linear distances on the lip and nose. Twenty-five sets of direct measurements were taken, prospectively, on 15 children with repaired cleft lip over a 6-year period. The results were submitted to regression analysis. Then, relevant lip and nasal tip aesthetics were evaluated by the measuring capabilities of NIH-Image to create a quantitative assessment tool. For each episode, 15 possible faults were weighted, according to aesthetics and deformity, to provide an adverse score. The sum of the 5 lip scores, 10 nose scores, and combination gave respective grades. The analysis was modified to stratify congenital deformity to relate severity of disease to outcome. This analysis was applied to digitized images of 19 consecutive children, immediately prior to repair of complete unilateral cleft lip and nose, at the time of palate repair, and annually from the age of 3 to 6 years. There were 19 NIH-Image-based measurements of the congenital deformity and 35 measurements of surgical results; four children had three sets of records, eight had two sets, and seven had one set Descriptive statistics were applied. Following 556 paired direct and computer-assisted measurements, exceptional linear correlation was shown with a Pearson R coefficient of 0.96. The best correlation was lines within the plane of the camera lens, with the average difference ranging between 0.025 and 0.997 mm. Visual inspection of frontal and submental photographs of excellent, good, and poor results substantiates the ability of this analysis to quantify and grade a spectrum of relevant cleft lip and nasal anatomy. For these 19 patients, there was a broad range of performance scores, approximating a normal distribution. The mean of the NIH-Image-based analysis scores, 16.91, was a (very) good grade. A single standard deviation of 6.88 extended up into excellent and down to fair. The congenital analysis indicated a range of deformity. Comparing deformity with outcome, simple regression analysis had a coefficient of determination (R2) of 0.223, indicative of a weak positive relationship. An accurate and practical morphologic computer-assisted outcome assessment of repaired cleft lip and nasal deformity has been developed. There is a weak direct correlation between severity of deformity and outcome. Testing in multiple clinics is warranted.

Anthropometry↗

Composite tissue allografts in rats: IV. Graft-versus-host disease in recipients of vascularized bone marrow transplants.

This laboratory has used a composite tissue allograft model as a vehicle for studies on a new type of bone marrow transplant, the vascularized bone marrow transplant. The model consists of a rat hind limb transplant that incorporates integumentary musculoskeletal, and lymphopoietic tissues. These transplants, in comparison with conventional marrow transplants, have the advantage of providing a syngeneic microenvironment and immediate engraftment of both mature and progenitor hemopoietic cells at the time of transplantation. The characteristics of graft-versus-host disease were studied in this model. Lewis X Brown Norway F1 (LBN RT-1(1+n)) rats received hind limbs from Lewis (LEW RT-1(1)) donors (n = 19). Animals were observed daily for signs of graft-versus-host disease. Necropsies were performed. A minority of animals developed lethal disease (7 of 19 recipients) and demonstrated cachexia with concomitant histopathologic changes of the disease. Acute and chronic groups emerged with distinct clinical courses, which are similar to other models of this disease. Recipients of vascularized bone marrow transplants (limb transplants) showed clinical and histopathologic changes of the disease. The transplants may be used as a model of graft-versus-host disease in humans. Most interestingly, the transplant has a lower incidence of disease compared with other methods of bone marrow transplantation and represents an alternative to conventional bone marrow transplantation, which deserves further exploration. It may be possible to develop a new technique for bone marrow transplantation based on this surgical approach. It is proposed that the transfer of vascularized blocks of bone/marrow into prospective recipients as opposed to cellular bone marrow transplants may be preferable.

Animals↗

Immune considerations in tissue engineering.

This article discusses the interplay between manmade living tissues and nature's given ones. Through a multidisciplinary approach, new strategies are outlined to control early inflammatory biochemical events, cell migration and development, and matrix deposition, all of them directed toward the acellular component of tissue-engineered constructs. The construct's resident nonautologous cells are targeted by cell- and humoral-mediated reactions, and modulatory strategies are applied to arrest rejection. The fate of ex vivo virally transfected, genetically engineered cells also is reviewed.

Biocompatible Materials↗

Emerging approaches to the tissue engineering of fat.

The eventual development of tissue-engineered fat equivalents for reconstructive and augmentation purposes will be most welcome by nearly every surgical discipline and prove to be especially useful for plastic surgeons. The clinical applications for which tissue-engineered fat will be particularly useful are vast and varied and can be loosely categorized into reconstructive, cosmetic, corrective, and orthotic indications. In this article, the authors discuss the emerging tissue-engineering strategies for fat, including the procurement of autologous cells, cell growth and differentiation, implantation and engraftment, polymer scaffolds, and implant integration and histogenesis.

Adipocytes↗

Quantitative facial motion analysis after functional free muscle reanimation procedures.

The purpose of this study was to evaluate the success of functional free muscle transfer in patients with chronic facial paralysis using a recently developed quantitative method known as the maximum static response assay of facial motion. A retrospective review of a single surgeon series of six patients with longstanding facial paralysis was performed. The maximum static response assay was performed on all patients preoperatively and serially during the postoperative period. Twenty-seven patients (54 sides) with normal facial function were also evaluated and served as controls. The contralateral normal side in those patients with unilateral facial paralysis (n = 4) also served as a control. Movement of the modiolus during smile was recorded in the x axis and y axis. To determine net smile movement, the vector of movement was calculated by means of the Pythagorean theorem. Vectors were then defined mathematically by calculating direction and magnitude. The average direction of the vector during smile for the normal control population was 58.3 degrees (range 32.5 to 83.1 degrees) from the horizontal through the modioli, and the average magnitude was 10.6 mm (range 4.2 to 20.1 mm). The average preoperative direction for the reanimated sides was 176.8 degrees with a range of 83.3 to 225 degrees. Patients with bilateral paralysis (n = 2) were excluded for calculation of the vectors on the normal contralateral side. The average preoperative direction for the normal contralateral side in patients with facial paralysis was 58.3 degrees with a range of 48.2 to 68.4 degrees. Postoperatively, the average direction of the vector during smile for the reanimated sides improved to a value of 77.6 degrees with a range of 45.7 to 113.8 degrees. The average change in direction of the preoperative reanimated side compared with the postoperative reanimated side was significant (p = 0.01). Postoperatively, the average direction of the vector for the contralateral normal sides was 43 degrees with a range of 11 to 57.2 degrees. The change in direction for the contralateral normal side was not significant (p = 0.18). The average magnitude of the reanimated side improved from a non-anatomic 2.8 mm preoperatively (range 0.8 to 6.8 mm) to an anatomic 4.9 mm postoperatively (p = 0.02). The contralateral normal side magnitude decreased from 9.4 mm (range 7.3 to 11.6 mm) preoperatively to 5.7 mm (range 3.8 to 7.7 mm) postoperatively (p = 0.006). More specifically, the absolute change in movement on the reanimated side during smile for the x axis and y axis was 2.3 mm (p = 0.05) and 4.0 mm (p = 0.002), respectively. This corresponded to an absolute change in the magnitude of the vector of 4.6 mm in an anatomic direction. On the contralateral side the absolute change in magnitude during smile from preoperative to postoperative for the x axis and y axis decreased by 1.5 mm (p = 0.13) and 5.3 mm (p = 0.05), respectively. This reflected an absolute change in the magnitude of the vector of 5.5 mm. Functional free muscle transfer in patients with chronic facial paralysis resulted in anatomic recovery of motion in the majority of patients in this series. The maximum static response assay can be used to objectively assess the results of facial reanimation.

Adult↗

Postoperative abdominal wall defects with enterocutaneous fistulae.

BACKGROUND: Abdominal wall dehiscence with an associated enterocutaneous fistula is a surgical complication with high morbidity and mortality. Management of the abdominal wall defect is complicated by the continued emergence of liquid bowel contents. PATIENTS AND METHODS: Large abdominal wall wounds of 10 patients with postoperative abdominal wall dehiscence and active enterocutaneous fistulae were managed with early skin grafting directly onto the granulated abdominal viscera. RESULTS: Skin graft take averaged 93 +/- 12%, and there were no perioperative complications related to the skin grafting procedure. Overall mortality was 1 out of 10 patients. Enterocutaneous fistula output did not prove overly injurious to the skin grafts. Wound care was simplified in all but 1 patient with fitting of an ostomy appliance. CONCLUSION: Temporary abdominal wall wound closure with skin grafts improved patient comfort and simplified wound care in a staged reconstructive approach to this surgical complication.

Abdominal Injuries↗

Fascial release as an adjunct to wound closure.

We describe a simple technique to facilitate the primary closure of skin defects. Skin, subcutaneous tissue and fascia are undermined as a unit on both sides of the defect. Fascial releasing incisions are performed, creating two bipedicled fascial flaps attached to the overlying skin. The fascia is approximated, if possible, and the skin sutured. We believe this technique offers a number of advantages and results in a superior closure to that obtained with the conventional method of skin undermining. This approach has enabled the closure of 10 of 11 medium sized wounds.

Adult↗

Graft-versus-host disease in limb transplantation: digital image analysis of bone marrow and TGF-beta expression in situ using a novel 3-D microscope.

A subpopulation of parental to hybrid VBMT recipients developed characteristic clinical and histopathologic manifestations of GVHD. These changes are similar to those seen in human GVHD secondary to bone marrow transplantation. Human GVHD also manifests itself in an acute and chronic manner. Only a minority (30% to 40%) of animals developed lethal GVHD in our model. Those animals developing GVHD had a significantly (P < .0001) higher expression of TGF-beta in situ compared to the tolerant subpopulation. The differential expression of TGF-beta may represent an important mechanism of immune dysregulation associated with GVHD in CTA recipients.

Animals↗