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J Lozano

Publications and source records attributed to J Lozano.

70 records · Page 4Linked to original sources
PubMedDate not supplied

Partial characterization of IR-alpha-MSH peptides found in melanoma tumors.

Our previous work indicated that IR-alpha-MSH (immunoreactive alpha-melanocyte-stimulating hormone) plasma levels are three times as high in melanoma patients with progressing disease than in disease-free patients, and that the melanoma tumor itself may be the source of IR-alpha-MSH. Further identification of the material in tumor extracts has been carried out in this study, and the results presented here show that the immunoreactivity is associated with a major fraction of about 16 kDa and another of 5-9 kDa. Significant amounts of the immunoreactive material were also found in human melanoma cells but not in culture supernatants. The presence of this material may be related to the melanogenic status of the tumor cells. We have estimated the intracellular IR-alpha-MSH to be within a 0.4 to 2.3 nM range in melanoma tumor cells. We have investigated the melanogenic effect of the IR-alpha-MSH material and its relationship to alpha-MSH. Purified extracts both from metastases and cultured cells were found to promote frog skin darkening as well as tyrosinase activity in Cloudman S91 melanoma cells. The IR material could also displace labeled alpha-MSH from its binding sites in human melanoma cells. Our data clearly indicate that melanoma cells engage in an autocrine production of alpha-MSH-like bioactive peptides by melanoma cells, of larger mol.wt., which are able to bind to MSH receptors. These peptides may be involved in the regulation of melanogenesis and possibly in the growth and proliferation of melanoma cells by an autocrine/paracrine mechanism.

Adult↗
PubMedDate not supplied

[Vaccine coverage and levels of protection with triple viral vaccine in a children population].

The purpose of this study is to know the immunity status of children in 10th area of Madrid and the effectiveness of vaccination campaigns against rubella, mumps and measles. An epidemiological interview together with ELISA have been used to determine the antibodies rates. 87.8%, 77.3% and 69.3% children studied were found to have immunoprotection against this viral infections. These rates are lower than those recommended by WHO; however, by age groups, the study shows statistically significant increase in children aged 5 years or less, what means a progressive acceptance of measles, rubella and mumps vaccination by population.

Antibodies, Viral↗
PubMedDate not supplied

[Kniest's disease. Metatropic dwarfism (author's transl)].

A new case of Kniest's Disease (bone dysplasia, retinal detachment and deafness), the first one in Spanish medical literature, is reported. Clinical and radiological considerations are made. Finally genetic theories of transmision and diagnosis of the disease are discussed.

Bone Diseases, Developmental↗