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Biomedical subjects

D LaRossa

Publications and source records attributed to D LaRossa.

At least 55 records · Page 3Linked to original sources
PubMed1985

The role of lymph node dissection for clinical stage I malignant melanoma of intermediate thickness (1.51-3.99 mm).

The survival times of patients who had an elective regional lymph node dissection was compared with that of those who did not undergo the procedure in a database of 72 patients with clinical Stage I melanoma of intermediate thickness (1.51-3.99 mm). All of the patients had been followed for 5 years or longer or until death. No significant differences were found in other reported prognostic factors, suggesting that the two groups were comparable. By multivariate analysis, a low mitotic rate, intermediate patient age, and the presence of an infiltrative lymphocytic response were found to be associated with favorable survival. There did not appear to be any association of elective regional lymph node dissection with survival; and it was concluded that such therapy should not be regarded as "standard" for clinical Stage I melanoma of intermediate thickness.

Actuarial Analysis↗
PubMed1984

Assessment of neovascularization and timing of flap division.

These studies were undertaken to determine if perfusion fluorometry can provide an accurate, reliable means of monitoring neovascularization and predicting optimal time of flap division. An animal model was developed that permitted daily assessment of neovascularization of the flap using fluorescein injections and the fluorometer. An increase in fluorescence of the pedicle-occluded flap of approximately 12 percent the normal skin fluorescence was associated with 100 percent flap survival. This occurred after only 4 days in the rat. Fluorometry proved valuable in the evaluation of clinical flaps. The fluorescence of flaps during pedicle occlusion was observed to increase with each successive fluorometric evaluation performed at 3- to 7-day intervals. It appears that flaps after pedicle occlusion exhibiting at least 25 percent of the fluorescence of normal skin will tolerate pedicle division. Based on the neovascularization studies of the clinical flaps, all pedicles were severed earlier than originally anticipated. Two cross-leg flaps were successfully divided after 11 days. Quantitative assessment of serial fluorescein injections allows reliable evaluation of neovascularization in clinical interpolation flaps and is useful in the timing of flap division.

Animals↗
PubMed1983

Evaluation of the burn wound with perfusion fluorometry.

Determination of depth of burn injury using vital dyes has been unsatisfactory. The present study evaluated the ability of the fiberoptic perfusion fluorometer to assess the depth of burn in the early postburn period. Sixty-three burns were examined with the fluorometer after intravenous administration of sodium fluorescein. The fluorescein kinetics were monitored for 1 hour within the first 48 hours and again between the third and sixth days postburn. The rate of fluorescein uptake and burn wound fluorescence was determined and compared to that of normal unburned skin. Depth of burn was confirmed by biopsy and healing characteristics. Fluorometric analysis during both study periods consistently distinguished between partial-thickness and full-thickness burns. Partial-thickness burns uniformly exhibited fluorescence within 10 minutes; full-thickness burns showed nil fluorescence. None of the patients experienced a change in skin color or complications from the small dose of fluorescein given.

Burns↗
PubMed1983

Optimal resection margin for cutaneous malignant melanoma.

Cutaneous malignant melanoma has traditionally been treated by "wide" local excision with a 5-cm margin of normal skin about the tumor. The rationale of wide excision for melanoma has never been clearly defined, but the procedure is known to be effective in preventing local recurrence. We studied 105 patients who had 109 primary melanomas in 1977 and related margin width of the definitive excision to the presence of satellites, to the subsequent development of local recurrence and in-transit metastases, and to survival. Survival was not dependent on margin width, and there were no incidences of local recurrence. Satellitosis and in-transit cutaneous metastasis indicate that a melanoma is capable of local recurrence; these phenomena occurred only in tumors whose thickness (Breslow) was greater than 2.0 mm. These data provide a rationale for wide excision of "thick" melanomas and support more modest local therapy for thin cutaneous melanoma.

Adult↗
PubMed1983

Phenotypic characteristics of cells derived from precursors of human melanoma.

Of 66 specimens from benign melanocytic nevi, including common acquired and congenital nevi, Spitz tumors (epithelioid cell nevi), and melanocytic nevi with dysplasia, 57 could be grown in tissue culture. The cultured cells were identified as melanocytes by the presence of premelanosomes and melanosomes. Cells from 28 of 32 nevus cultures grew in an anchorage-independent way in soft agar with a colony-forming efficiency between 0.001 and 1%. Clones derived from single cells and soft agar-selected colonies showed marked phenotypic heterogeneity, but all had a limited life span and did not undergo transformation in culture. These cells were nontumorigenic in nude mice. Cultured nevus cells expressed antigens present on melanoma but absent on normal fibroblasts and/or melanocytes as tested with monoclonal anti-melanoma antibodies. The anti-melanoma antibodies bound equally well to dysplastic, congenital, and common acquired nevi. Antigens are released by nevus cells similar to melanoma cells.

Antigens, Neoplasm↗
PubMed1982

Altered skin flap survival and fluorescein kinetics with hemodilution.

Isovolemic hemodilution is known to reduce blood viscosity. Reduction of either the blood cell concentration or the serum total protein has been found to improve blood flow and ultimate survival of skin flaps. Nutritive blood flow and tissue survival were examined in dorsal pedicle skin flaps in three groups of rats at three hematocrit levels--44% (controls), 31%, and 19%. After hemodilution by phlebotomy and crystalloid replacement, the dye kinetics of intravenously administered fluorescein were measured with the fiberoptic perfusion fluorometer. Skin flap survival at the different hematocrits were also examined. Hematocrits and serum total protein were measured before and after hemodilution and the elevation of the flap. The rate of fluorescein elimination and ultimate flap survival were significantly augmented in the two hemodiluted groups. The maximum benefit was seen in the group of animals hemodiluted to 19%. However, significant improvement in blood flow and skin flap survival was noted in the group of animals that were hemodiluted to a more clinically acceptable level (31%). The decreases in serum total protein following flap elevation did differ among the groups. This study supports the hypothesis that isovolemic hemodilution may be a valuable technique for salvaging marginally ischemic tissues.

Animals↗
PubMed1981

Scalp avulsions and review of successful replantation.

Microvascular surgery has greatly altered the handling of scalp avulsions. Review of the injury mechanism and of successful replantations has yielded some basic axioms concerning treatment of this tragic injury. Generally, larger avulsions contain vessels that are easily identified and anastomosed, and therefore have a better prognosis. Long periods of ischemia do not appear to threaten graft viability. The superficial temporal artery is the most reliable artery for scalp replantation; accompanying veins can normally be used for venous drainage, though vein grafts are often needed due to vessel disruption at injury. Replantation should be attempted with all scalp avulsions, though the size of the defect and its location will affect the outcome.

Accidents, Occupational↗
PubMed1980

The use of microvascular free skin-muscle flaps in management of avulsion injuries of the lower leg.

The authors used microvascular free skin-muscle flaps to cover avulsion wounds in the lower leg of ten patients. There were three children and seven adults, ranging in age from 5 to 54 years. Vessels supplying gracilis (four) and tensor fascia lata (six) skin-muscle units were anastomosed to the anterior tibial (nine) and posterior tibial (one) vessels. The tensor fascia lata unit has a more constant anatomy and is preferred. Principles of management include: 1) early adequate, but conservative, debridement; 2) continuous bony stabilization; 3) preoperative arteriography; 4) anticoagulation; 5) recipient vessel identification in healthy uninjured tissue; 6) appropriate timing; 7) delayed bone grafting.

Adolescent↗
PubMed1980

Specific immunoreactivity of hybridoma-secreted monoclonal anti-melanoma antibodies to cultured cells and freshly derived human cells.

The specificities of monoclonal antibodies against melanoma cells were analyzed using radioimmunoassay, mixed-hemadsorption assay, and quantitative absorption on a variety of malignant and nonmalignant cells. Three of the six hybridoma-secreted antibodies bound to the majority of melanoma cell lines, melanoma tumors, and astrocytoma cell lines as well as to all normal and Epstein-Barr virus-transformed lymphocytes tested. The binding pattern coincides with the presence or absence of the DR antigen on human cells. Conversely, two other antibodies, 19-19 and Nu4B, detected two different antigens common to melanoma and astrocytoma cells only. Cloning of melanoma cells resulted in establishment of DR-positive and DR-negative clones, with the binding of Nu4B antibody retained in all.

Animals↗
PubMed1975

Structural goals in craniofacial surgery.

Major craniofacial abnormalities can be considered as a group for purposes of operative planning. Known normal relations define what is abnormal and indicate goals to be achieved with the craniofacial operative procedures. The principle syndromes with significant facial structural changes amenable to such surgical corrective procedures are craniofacial stenoses, hypertelorism, mandibulofacial dysostoses, median facial clefts, residua of encephaloceles, and trauma. Deformities primarily involve the middle and upper thirds of the face. In planning, abnormal relations and structures must be clearly defined utilizing patient examination, x-rays, dental study models, and photography. Standards of norm indicating goals for the corrective procedure are also based on studies using these tools, data from previous publications, and measurements directly from skulls. Precise measurements about the orbits and maxillary-mandibular relation are the keystone for planning. Soft tissue, nose, and ear alterations are based on already widely known concepts of norm and symmetry. Bony interocular distance, medial intercanthal distance, height and width at the orbital rim of the bony orbits, orbital shape, orbital axis, and orbital volume as determined by measurement with an exophthalmometer are useful in determining what is to be done about the orbits. Cribiform plate level, anterior cranial base, length and contour, and size of the zygomatic arches are important dimension considerations. Paranasal sinus size and location is important. These considerations are essential prior to any major facial structural changes.

Adult↗