Biomedical subjects

T Mauro

Publications and source records attributed to T Mauro.

24 records · Page 2Linked to original sources

PubMed1994

Treatment of pyoderma gangrenosum with cultured keratinocyte autografts.

BACKGROUND: Pyoderma gangrenosum is an uncommon chronic skin disease characterized by rapidly enlarging cutaneous ulcers. Immunosuppressive agents, such as corticosteroids, are the mainstay of therapy. OBJECTIVE: We describe a patient with pyoderma gangrenosum treated with cultured keratinocyte autografts for a full-thickness ulcer located on the dorsal and lateral aspects of the foot. METHODS: After stabilizing the ulcer with intralesional and systemic corticosteroids, the ulcer was debrided and cultured keratinocyte autografts were secured with nylon mesh. An outer dressing of gauze and elastic bandage was used. RESULTS: The patient had > 95% "take" of the grafts and the ulcer was fully healed in less than 1 month. The grafted area preserved the clinical phenotype of the palmar skin from which the original biopsy was taken. CONCLUSION: Cultured keratinocyte autografts can provide permanent wound coverage for patients on high doses of immunosuppressive medications.

Administration, Oral↗

PubMed1990

Establishment of a human cutaneous T-cell lymphoma in C.B-17 SCID mice.

Investigation into the immunobiology of cutaneous T-cell lymphomas (CTCL) would be facilitated by the development of a suitable experimental system. The recent use of mice with severe combined immune deficiency (SCID) as a vehicle to study the human immune system prompted us to try to establish CTCL in SCID mice. We found that a CD4+ lymphocytic infiltrate characteristic of CTCL was maintained within patient skin grafts in place on natural killer cell depleted SCID mice for the month of observation. CTCL cells were not found outside the human skin graft. This chimeric model using SCID mice and patient lesional skin should provide a useful tool to characterize CTCL/skin microenvironmental interactions and to test new therapeutic approaches.

Animals↗

PubMed1989

Linear granuloma annulare.

Granuloma annulare is a benign dermatosis with multiple clinical presentations and a common histologic picture, which is characterized by areas of degenerated collagen surrounded by palisading histiocytes. A case of granuloma annulare that presented as progressive, asymptomatic, symmetric truncal bands is described. The varied clinical presentations and possible pathogenetic mechanisms of granuloma annulare are reviewed.

Granuloma↗

PubMed1987

Effects of TPA on short-circuit current across frog skin.

TPA (12-O-tetradecanoylphorbol-13-acetate) is an effective tumor promoter that affects a variety of ion transport processes. To examine the relationship between effects on transport and growth and differentiation, we have been studying the actions of TPA on frog skin, a particularly well-characterized epithelium. We have reported that high concentrations of TPA stimulate base-line short-circuit current (ISC) and inhibit the subsequent natriferic action of vasopressin. The current study of 89 preparations extends those findings. The Km of the stimulatory effect of TPA is approximately 3 nM; this high affinity indicates that the transport phenomenon does not simply reflect a nonspecific interaction of phorbol ester with the plasma membranes. TPA acts largely or entirely at the mucosal surface of both split and whole skins; thus the sidedness of the effect does not arise from adsorption onto the underlying connective tissue when TPA is applied to the serosal surface of whole skin. Amiloride, an inhibitor of apical Na+ entry, abolishes ISC across frog skins pretreated with TPA. The phorbol ester also increases ISC across split skins, preparations which do not produce net Cl-transport. Indomethacin (1 microM) blocks PGE1 release, but does not alter the response to TPA at a fivefold lower concentration than previously used. NDGA (nordihydroguaretic acid, 10 microM), an inhibitor of the lipoxygenase pathway, partially inhibited the responses of ISC to 8 nM TPA. The present results indicate that frog skin is highly responsive to TPA at concentrations known to activate protein kinase C in broken-cell preparations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1985

Effects of tumor promoters on sodium ion transport across frog skin.

Phorbol esters are tumor promoters and mitogens whose effects may be mediated by changes in ion transport across membranes. Clarification of the transport effects of these agents should be facilitated by using a well-characterized model epithelial system whose intracellular and transmural parameters are readily measurable. The current results constitute a preliminary study of the effects of 12-O-tetradecanoylphorbol-13-acetate (TPA), phorbol-12,13-dibutyrate (PDBU), and phorbol on the short-circuit current (Isc) across frog skin. TPA produced two effects: a stimulation of Isc of variable magnitude and a far more constant inhibition of the natriferic action of vasopressin. These effects appear related to the action of TPA as a tumor promoter insofar as PDBU (an active ester) also inhibited the natriferic response to vasopressin, whereas phorbol (inactive as a tumor promoter) had no significant effect. TPA is largely active from the mucosal medium, inhibits the natriferic response to adenosine 3',5'-cyclic monophosphate (cAMP) as well as that to vasopressin, and does not stimulate Isc in the presence of 10(-4) M mucosal amiloride. Inhibition of prostaglandin E1 production by indomethacin had no effect on the actions of TPA. The results indicate that frog skin is a promising model for studying the transport effects of the phorbol esters. The data further suggest that TPA acts on frog skin by activating the physiological amiloride- and cAMP-sensitive channels gating apical Na+ entry from the mucosal medium into the epithelial cells.

Amiloride↗

PubMed1979

Postcapillary pH disequilibrium after gas exchange in isolated perfused liver.

pH equilibration after gas exchange in a systemic vascular bed was investigated using an isolated guinea pig liver preparation perfused with a blood-free Krebs-Ringer-bicarbonate solution. Effluent perfusate was withdrawn into a stopped-flow apparatus in which pH and temperature were continuously monitored. A decrease in pH of the perfusate after exit from the liver was observed. Addition of acetazolamide to inflowing perfusate had little effect on this fall in effluent fluid pH, while the addition of carbonic anhydrase completely abolished the decrease in pH. These results suggest that: 1) after the addition of metabolically produced CO2, the reaction CO2 leads to H2CO3 leads to H+ + HCO3- in the perfusate did not reach equilibrium during passage through the liver; 2) acetazolamide had little effect on the magnitude of the pH disequilibrium; and 3) carbonic anhydrase accelerated the reaction to equilibrium. We conclude that little or no catalysis of the conversion of perfusate CO2 to H2CO3 takes place within the hepatic circulation and that the presence of slow postcapillary blood pH changes in vivo may be dependent on the specific species and organ vascular bed from which the blood exited after participating in gas exchange.

Acetazolamide↗