Angiogenic and antifibrotic actions of hepatocyte growth factor improve cardiac dysfunction in porcine ischemic cardiomyopathy.

Impairment of cardiac function in ischemic cardiomyopathy has been postulated to be due to the decrease in blood flow and increase in collagen synthesis. Therefore, an approach to alter them directly by means of a growth factor may open up a new therapeutic concept in ischemic cardiomyopathy. From this viewpoint, hepatocyte growth factor (HGF) is a unique growth factor with angiogenic and antifibrotic effects. Thus, we examined the feasibility of gene therapy using HGF plasmid DNA for ischemic cardiomyopathy. Human HGF plasmid DNA at a dose of 0.4 or 4 mg was injected into ischemic myocardium of pigs induced by ameroid constrictor with the NOGA system. At 1 month after injection, the ischemic area was significantly reduced in the HGF group, accompanied by a significant increase in capillary density and regional myocardial perfusion in the ischemic area (P<0.01). In contrast, a significant decrease in fibrotic area was observed in the HGF group, associated with a significant decrease in collagen I, III and TGF-beta synthesis as compared to the control group (P<0.01). Consistently, cardiac function was significantly improved in the 4 mg HGF group as compared to the control group (P<0.05). Overall, the present in vivo experiments demonstrated that intramyocardial injection of human HGF plasmid DNA in ischemic cardiomyopathy resulted in a significant improvement in cardiac function through an increase in blood flow and decrease in fibrosis. These favorable outcomes suggest potential utility to treat patients with ischemic heart disease using HGF gene transfer. Currently, a phase I study using human HGF plasmid DNA is ongoing to test the validity of this concept.

Examination of HTLV-I integration in the skin lesions of various types of adult T-cell leukemia (ATL): independence of cutaneous-type ATL confirmed by Southern blot analysis.

The various clinical features of adult T-cell leukemia/lymphoma (ATL) are frequently accompanied by skin eruptions. Recently, a cutaneous type of ATL has been proposed by clinical studies. We analyzed the viral integration of human T-cell leukemia virus-I (HTLV-I) and monoclonal rearrangement of T-cell receptor (TCR) gene in blood lymphocytes and the cutaneous infiltrated cells of nine ATL patients with various clinical features and skin eruptions. We classified them by the results of Southern blot analysis and propose a cutaneous-type ATL accordingly. In two of them, we could detect the monoclonal integration of HTLV-I and T-cell monoclonality only in the skin but not in the peripheral lymphocytes. We also demonstrated the time course study in one patient. Clinicians should be aware of the HTLV-I positive cutaneous T cell lymphoma that can be named cutaneous-type ATL. Examination of viral integration and T-cell monoclonality in skin lesions is required to make an exact diagnosis of cutaneous ATL.

Southern blot analysis of clonal rearrangements of T-cell receptor gene in plaque lesion of mycosis fungoides.

T-cell populations of 22 plaque lesions from seven mycosis fungoides patients were studied for clonal rearrangement of the beta chain of the T-cell receptor (T beta) gene. All plaque lesions employed in this study showed clinically similar appearance. Histologically, all the biopsy specimens showed epidermotropism and the dermal infiltration of mononuclear cells including atypical cells. Histochemically, the majority of the infiltrated cells had surface markers of helper T cells. DNA extracted from skin lesions, peripheral lymphocytes, and lymph nodes revealed that the monoclonal expansion of T cells was different among patients and lesions. DNA extracted from the two skin lesions of case 1 revealed a clonal expansion of T cells. The rearranged bands persisted for about 1 year. In contrast, all lesions from cases 3-7 showed no rearranged band. Interestingly, three lesions from case 2 showed mixed type results, i.e., the monoclonal expansion of T cells was detected in one lesion but not in the other two lesions. Time course study of case 2 revealed that the same rearranged band became detectable in all three skin lesions and a lymph node about 1 year later. These results suggest that in plaque lesions of mycosis fungoides, there are various stages of detectable monoclonality of infiltrating cells, although the clinical appearance of the plaques was similar, and that the variety of monoclonality may reflect the long clinical course of this disease.

Lymphomatoid papulosis: ultrastructural, immunohistochemical and gene analytical studies.

Ultrastructural, immunohistochemical and gene analytical studies were carried out on a 39-year-old patient with lymphomatoid papulosis. Two different cell groups were demonstrated in the papulonodular eruptions: large atypical cells with multiple nuclei that were well stained with anti-Tac, but not with Leu 3a, and other cells that possessed prominent hyperchromatic nuclei and which stained well with Leu I and Leu 3a but not with anti-Tac. Gene analytical studies using EcoRI, BamHI and HindIII revealed no rearrangement, indicating a non-clonal T-cell proliferation unlike malignant T-cell lymphoma. These results suggest that the present case was benign.

Analysis of epidermal growth factor receptor gene in psoriasis.

Epidermal Growth Factor (EGF) plays an important role in cell proliferation. In psoriasis, increased histochemical expression of EGF receptor has been reported in the epidermis. In order to elucidate the mechanism of this increase, we studied the EGF receptor gene organization in psoriasis. DNAs were extracted from white blood cells of 5 patients with psoriasis and 5 normal controls and also from epidermis of 2 psoriatic patients and 1 normal control, and analyzed by Southern blot technique. There were no differences in the structural organization of EGF receptor gene in either white blood cells or epidermis between psoriatic patients and normal controls. These results suggest that the histochemical increase of EGF receptor in the epidermis of psoriatic patients is not due to a structural change in this gene.