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J Slama

Publications and source records attributed to J Slama.

11 recordsLinked to original sources
PubMed1999

[Renal medullary carcinoma, a new clinico-pathological entity. Immunohistochemical, ultrastructural, flow cytometric and cytogenetic study of a case].

The renal medullary carcinoma is a rare tumor. We report a case in a black patient with sickle cell trait. The tumor was located in the lower pole of the left kidney. It had a tubular and microcystic architecture. It was composed of large eosinophilic cells with vesicular nuclei containing prominent nucleoli, in a desmoplastic and inflammatory stroma. By immunohistochemistry, the tumoral cells were positive for cytokeratin and Ulex europaeus lectin. Electron microscopy revealed small intracytoplasmic lumina with microvilli. The flow cytometric study showed DNA-multiploidy. The cytogenetic study revealed tetraploidy without structural abnormality. The renal medullary carcinoma is often reported in young black patients with sickle cell trait. Its microscopic, immunohistochemical and ultrastructural features favor its identification as a particular variety of Bellini duct carcinoma. Its link with sickle cell trait has to be defined.

Adult↗
PubMed1998

In vivo gene transfer to skin and wound by microseeding.

BACKGROUND: Gene transfer to skin has many potential applications but lacks a safe, practical delivery method. This report presents a new technique, microseeding, for in vivo gene transfer to skin and wounds and for DNA-mediated vaccination. The plasmid DNA solution was delivered directly to the target cells of the skin by a set of oscillating solid microneedles driven by a modified tattooing device. MATERIALS AND METHODS: Skin and partial-thickness excisional wounds in pigs were microseeded with either hEGF expression plasmid or beta-galactosidase expression plasmid. Human EGF was also delivered by single injection or particle bombardment. hEGF expression in wound fluid and in target tissue was determined by ELISA with anti-hEGF-specific antibodies. Additionally, weanling pigs were microseeded with a hemagglutinin of swine influenza virus expression plasmid and production of anti-HA-specific antibodies was determined by blocking ELISA. RESULTS: hEGF expression in microseeded partial thickness wounds (5664 pg/site) and skin sites (969 pg/site) peaked 2 days after transfection being four- to seven-fold higher than gene transfer by a single intradermal injection and two- to three-fold higher than particle-mediated gene transfer. The beta-galactosidase-expressing cells were detected in dermis and epidermis. Pigs microseeded with HA expression plasmid were protected from infection by the Swine influenza virus. CONCLUSIONS: These results demonstrate that microseeding is a simple and effective method for in vivo gene transfer to skin and wounds and is more efficient than single injection and particle-mediated gene transfer.

Animals↗
PubMed1997

Growth factors in the repair of partial thickness porcine skin wounds.

In 28 porcine partial thickness excisional wounds, the presence of several growth factors was first studied by enzyme-linked immunoadsorbent assay on wound fluid collected in sealed wound chambers. Basic fibroblast growth factor (bFGF) peaked on day 1 at 31.4 pg/ml; platelet derived growth factor (PDGF)-AB on day 3 reached 45.2 pg/ml, and transforming growth factor-beta (TGF-beta) on day 7 was 726.1 pg/ml. The same chamber system was used in 48 partial thickness excisional wounds for delivery of nanogram doses of bFGF, PDGF-AB, insulin-like growth factor (IGF)-1, epidermal growth factor (EGF), and cholera toxin. PDGF and EGF accelerated healing (1.1 days and 0.3 days, respectively), whereas bFGF and IGF-1 had no effect. Cholera toxin retarded healing by 1.9 days. Furthermore, in 100 excisional wounds EGF in the concentration range of 10 to 1,000 ng/ml had the same stimulating effect on healing. EGF at 10,000 ng/ml significantly delayed healing. The wound chamber model is useful for detecting of endogenous growth factors as well as for delivering exogenous factors.

Animals↗
PubMed1996

Photodependent inhibition of bovine spleen NAD+ glycohydrolase by 8-azido carbocyclic analogs of NAD+.

Carba-NAD+ and pseudocarba-NAD+, and their 8-azidoadenosyl derivatives, were found to be good competitive inhibitors of calf spleen NAD+ glycohydrolase. The 8-azido compounds, tested as photoaffinity labels, inhibited the enzyme in a light- and time-dependent manner; this inhibition could be prevented by 3-aminopyridine adenine dinucleotide (n3PdAD+), a competitive inhibitor of NAD+ glycohydrolase. Irradiation in the presence of the [3H]-labeled 8-azido-carba-NAD+ derivative resulted in an irreversible incorporation of the radioactivity into the enzyme that could be largely prevented by addition of n3PdAD+. These results indicate that carbocyclic-analogs of NAD+ will be useful in identifying the substrate binding site of NAD+ glycohydrolase.

Affinity Labels↗
PubMed1996

Treatment of chronic, nonhealing abdominal wound in a liquid environment.

A 66-year-old woman with an abdominal wound caused by infected synthetic mesh had failed to heal in spite of many surgical attempts to close the wound. A sealed transparent vinyl chamber was glued to the periphery of the wound and antibiotics in high concentrations (up to 2,500 times the minimum inhibitory concentration) were delivered through the chamber. The wound fluid in the chamber was used for analysis of microbial activity, concentration of residual antibiotics, and growth factor activity. After 10 weeks of treatment, the wound was closed and has not recurred in 24 months.

Abdominal Injuries↗
PubMed1995

Dry, moist, and wet skin wound repair.

Effects of wet (saline in a vinyl chamber), moist (hydrocolloid dressing), and dry (sterile gauze dressing) environments on wound repair were studied in a porcine partial-thickness wound model. Chambers were exchanged and refilled daily with normal saline containing penicillin G (100 U/ml) and streptomycin (100 micrograms/ml). Hydrocolloid and gauze dressings were kept in place until biopsy of the wound site. Wounds in wet, moist, and dry environments were completely epithelialized on days 6, 7, and 8, respectively. Thickness of the epidermis in wet, moist, and dry wounds was 204 +/- 23, 141 +/- 12, and 129 +/- 18 (mean +/- SEM), respectively. Moist wounds had more subepidermal inflammatory cells than wet wounds. In comparison to dry wounds, the moist or the wet healing environment resulted in less necrosis and faster and better quality of healing in the formation of the newly regenerated epidermis.

Animals↗
PubMed1995

Gene transfer.

The principles and techniques of gene transfer are presented. Common concepts are defined, and the frequently used transfer vectors are described herein. Several gene transfer applications are discussed briefly. Areas of particular interest to the plastic surgeon such as gene transfer to skin and wounds are included.

Gene Expression↗
PubMed1994

In vivo transfer and expression of a human epidermal growth factor gene accelerates wound repair.

This report details the transfer of a human epidermal growth factor (hEGF) expression plasmid to porcine partial-thickness wound keratinocytes by particle-mediated DNA transfer (Accell). After gene transfer an external sealed fluid-filled wound chamber was used to protect the wound, provide containment of the exogenous DNA and expressed peptide, and permit sampling of the wound fluid. Analysis of wound fluid for hEGF and total protein, an indicator of reformation of the epithelial barrier, showed that wounds bombarded with the hEGF plasmid exhibited a 190-fold increase in EGF concentration and healed 20% (2.1 days) earlier than the controls. EGF concentrations in wound fluid persisted over the entire 10-day monitored period, decreasing from 200 pg/ml to 25 pg/ml over the first 5 days. Polymerase chain reaction results showed that plasmid DNA was present in the wound for at least 30 days. These findings demonstrate the possible utility of in vivo gene transfer to enhance epidermal repair.

Amino Acid Sequence↗
PubMed1980

Functional incorporation of synthetic glycolipids into cells.

Synthetic glycolipids containing an alpha-mannoside group linked by a hydrophilic spacer arm to cholesterol were incorporated into bovine erythrocytes by exchange from glycolipid-containing liposomes. When the distance between the sugar and the cholesterol moieties was approximately 26 A, functional incorporation of these glycolipids could be easily detected, as revealed by the concanavalin A-mediated agglutination of these cells. Bovine erythrocytes are not themselves susceptible to concanavalin A-mediated agglutination. The minimal concentration of concanavalin A required for agglutination of modified erythrocytes, containing 9.15 x 10(6) glycolipid molecules per cell, was 4 microgram/ml. Under these conditions, only approximately 4% of the membrane-bound cholesterol had been exchanged for the synthetic glycolipid. The observed aggregation was reversible in the presence of alpha-methyl mannoside and did not occur when beta-galactosyl-containing glycolipids were used in place of their alpha-mannoside isomers. These studies demonstrate a technique of sugar incorporation into cell membranes which should be of great advantage in studies on the roles of cell surface sugars in biological recognition. Furthermore, they demonstrate that the sugars need only be a short distance (26 A) from the membrane in order to functionally bind concanavalin A.

Animals↗