Biomedical subjects

L Nanney

Publications and source records attributed to L Nanney.

8 recordsLinked to original sources

PubMed1999

Adhesion formation is reduced after laparoscopic surgery.

BACKGROUND: Adhesion formation after abdominal operations causes significant morbidity. METHODS: Adhesion formation in pigs was compared after placement of prosthetic mesh during celiotomy (group 1), laparoscopy with large incision (group 2), and laparoscopy (group 3). After peritoneum was excised, polypropylene mesh was fixed to the abdominal wall, then to the opposite abdominal wall in the preperitoneal space followed by peritoneal closure. Adhesion area, grade, and vascularity were measured. RESULTS: More adhesions (p < 0.02) covered intraperitoneal mesh (7.57 +/- 1.89 cm2) than covered reperitonealized mesh (2.16 +/- 1.13 cm2), and adhesion grade was significantly greater (p < 0.02). Adhesion areas were significantly greater in groups 1 and 2 than in group 3 (p = 0.001 and 0.03, respectively). Adhesion grade was significantly greater in groups 1 and 2 than in group 3 (p = 0.02 and p = 0.04, respectively). Groups 1 and 2 had more vascular adhesions than group 3 (p < 0.01 and p = 0.02, respectively) CONCLUSIONS: A foreign body within the peritoneum stimulates more numerous and denser adhesions. Tissue trauma distant from the site of adhesions increases their formation. A major advantage of laparoscopic surgery is decreased adhesion formation.

Abdomen↗

PubMed1997

Enhanced tumor-forming capacity for immortalized melanocytes expressing melanoma growth stimulatory activity/growth-regulated cytokine beta and gamma proteins.

Three human MGSA/GRO genes encode 3 highly related chemokines, MGSA/GRO alpha, -beta and -gamma. All 3 MGSA/GRO proteins bind to the same receptors, but with differing affinities, and stimulate a number of biological responses including chemotaxis, angiogenesis, and growth regulation. We have previously demonstrated that MGSA/GRO alpha can be isolated from culture medium conditioned by malignant melanoma cells and that continuous secretion of MGSA/GRO alpha contributes to the transformation of immortalized murine melanocytes. The present study was designed to determine whether MGSA/GRO beta or -gamma have similar effects on melanocyte tumorigenicity. Stable Melan-a clones expressing either human MGSA/GRO beta or -gamma exhibited enhanced ability to form large colonies in soft agar and tumors in nude mice. The clones expressing the MGSA/GRO beta or -gamma transgene formed tumors within 2 months after injection; the tumors were highly pigmented and expressed immunoreactive MGSA/GRO beta or -gamma protein. Furthermore, when conditioned medium from Melan-a clones expressing MGSA/GRO alpha, -beta or -gamma transgenes were examined for the ability to induce angiogenesis in the rat cornea, strong angiogenic responses were observed. This angiogenic response was blocked by antibodies to the respective MGSA/GRO protein, but not by normal rabbit serum. By contrast, angiogenic responses were observed in only 2 of 12 corneal implants (17%) containing medium conditioned by Melan-a clones expressing the neomycin resistance marker alone.

Amino Acid Sequence↗

PubMed1997

Expression of bcl-2 in lichen planus, acute graft-versus-host disease, and erythema multiforme.

The bcl-2 gene family plays a significant role in the propagation of cell survival and tissue modeling. Bcl-2 was originally described in follicular lymphomas and is associated with the suppresion of cellular apoptosis. Evaluation for this protein has been performed for a variety of benign and malignant cutaneous tumors but not to any significant extent on inflammatory disorders. Therefore, we stained biopsy specimens from diseases with interface inflammation (lichen planus, acute graft-versus-host disease, and erythema multiforme) for Bcl-2. Epidermal expression of this protein was minimal for all three diseases; however, lymphocytes stained prominently in lichen planus. The data suggest that Bcl-2 is not prominently involved in the epidermal changes in these diseases. The role of other members of this oncogene family in interface dermatitis still needs to be elucidated.

Erythema Multiforme↗

PubMed1993

Localization of MGSA/GRO protein in cutaneous lesions.

Melanoma growth stimulatory activity (MGSA/GRO), a cytokine originally characterized as an autocrine growth factor for melanoma cells, is highly chemotactic for neutrophils and releases neutrophil elastase as well as other matrix-degrading enzymes. Previous work has demonstrated the presence of MGSA/GRO in melanocytic lesions and in the epidermal keratinocytes of non-lesional skin and psoriatic scale. Herein, MGSA/GRO localization was examined in a variety of human skin lesions exhibiting proliferative and/or differentiative disorders using immunohistochemical methods. Most lesions showed greater MGSA/GRO immunoreactivity in the more differentiated suprabasal keratinocytes of the stratum spinosum and stratum granulosum than in the stratum basalis, where the dividing basal cells are found. Hair follicles, sebaceous glands, and sweat glands were also frequently positive for MGSA/GRO. The highest level of immunoreactive MGSA/GRO in diseased epidermis was detected in verruca vulgaris, followed by psoriasis, keratoacanthoma, and squamous cell carcinoma. Detection of MGSA/GRO in basal cell carcinoma was variable, being present in the sclerosing variant and absent in the more common nodular variant. Melanocytic lesions stained less intensely for MGSA/GRO than keratinocytic lesions, where the levels of MGSA/GRO expression correlated with the inflammatory response and degree of keratinocyte differentiation.

Biopsy↗

PubMed1987

Latissimus dorsi flap: a valuable resource in lower arm reconstruction.

Lower arm reconstruction of soft tissue defects and after ablation for cancer leaves the reconstructive surgeon few alternatives. We have used latissimus dorsi muscle (n = 1) and musculocutaneous flaps (n = 3) with good functional and cosmetic results. Defects in one patient with traumatic amputation, another with extravasation of doxorubicin, and two with cancer were closed without complications to donor site, recipient site, or flap. Skin paddle size averaged 182 sq cm in the three musculocutaneous flaps. Mean follow-up was six months.

Aged↗

PubMed1984

Leupeptin's effect on organ weight, RNA, DNA, and protein content after long bone fracture in the rat.

Long bone fracture in the rat is accompanied by enhanced urinary nitrogen loss reflecting changes in protein synthesis and breakdown. The effects of leupeptin, an inhibitor of lysosomal proteases, were assessed on organ weights, RNA, DNA, and protein content after injury in the rat. Two groups of 8-week-old rats were studied: The first group received left femoral fracture. Half of these received leupeptin (25 mumole ip/day), and the remainder received saline. The second group served as uninjured pair-fed controls, with half receiving leupeptin and half receiving saline. On Days 0, 1, 2, 4, and 7 after injury, animals were sacrificed and organs were removed for determination of weight, RNA, DNA, and protein content. All injured rats lost weight, with maximum loss occurring on Day 4. Food intake was also reduced. Pair-fed rats lost the same amount of weight as injured ones, and leupeptin could not prevent whole body weight loss. Expressed as percentage of total body weight, livers from leupeptin-treated injured rats weighed 10% greater than saline-treated ones on Days 2, 4, and 7 after injury (P less than 0.05). No differences occurred in RNA, DNA, or protein contents. Diaphragms similarly weighed 10, 20, and 30% greater on Days 2, 4, and 7 after injury, respectively, in leupeptin-treated rats (P less than 0.05). In addition, the RNA and DNA contents of diaphragms were 96 and 88% greater, respectively, in treated rats than in controls (P less than 0.05) on Day 4. It is concluded that leupeptin causes a relative increase in the weights of livers and diaphragms after injury, and causes a marked increase in the RNA and DNA contents of diaphragms.

Animals↗

PubMed1984

Perfluorochemicals. Morphologic changes in infused liver, spleen, lung, and kidney of rabbits.

Perfluorochemicals have been shown to have a high affinity for oxygen and therefore, have potential use in circumstances in which conventional blood transfusions are not possible. We examined by light and electron microscopy (EM) histologic changes in liver, spleen, lung, and kidney of rabbits each infused with 20 to 40 mL of perfluorotributylamine or with lactated Ringer's solution (controls). Rabbits were killed at 1, 2, and 3 weeks after infusion. Spleen and liver showed the most marked alterations. Spleen architecture was distorted with focal infiltration by foamy macrophages. The EM showed macrophages containing small and large, membrane-bound vacuoles. In the liver, Kupffer's cells were enlarged with eccentric nuclei and vacuolated cytoplasm. Hepatocytes contained occasional perfluorochemical particles. In the lung, intimal cells were swollen in the muscular arteries. While in alveolar septae, perfluorochemical particles could be identified ultrastructurally in the alveolar phagocytes and in the endothelium of capillaries. Kidney changes were more subtle, with occasional foam cells seen within the mesangium. The number of vacuoles did not decrease with time in any of the organs examined. Therefore, perfluorotributylamine particles are retained in vital organs; what effects these particles may have on normal tissue function need further evaluation.

Animals↗

PubMed1983

Scleredema adultorum: the surgical implications of a rare dermatologic disorder.

A case report of nonpitting induration of the skin, scleredema adultorum of Buschke, is presented. Although it may be a benign, self-limited disease, its complications may require drainage of abscesses or soft-tissue coverage, which may result in delayed wound healing. In the reconstruction of tissue defects, skin grafts are preferred, since the skin is unyielding.

Adult↗