Identification and quantification of subsets of mononuclear inflammatory cells in melanocytic and other human tumors

We used monoclonal antibodies and an indirect immunoperoxidase technique to identify mononuclear inflammatory cells associated with human tumors. The absolute number of the different types of inflammatory cells was assessed by using a point-counting technique. We studied tissues from six primary cutaneous melanomas, six metastatic melanomas, eight melanocytic nevi, 14 breast cancers, seven examples of fibrocystic disease of the breast, 11 lung cancers, and six colon cancers. Virtually all tumors were associated with substantial numbers of T lymphocytes (Leu3a-positive T helper-inducer cells predominating) and macrophages. Primary melanomas contained significantly more T lymphocytes (P less than .002), macrophages (P less than .005), and Langerhans/dendritic cells (P less than .002) than nevi or normal skin and had a higher proportion of T cells than metastatic melanomas (P less than .01). Breast cancers contained more T lymphocytes and macrophages than occur with fibrocystic disease (P less than .0001 and P less than .002, respectively) and more B lymphocytes. Cancers of the lung and colon contained moderate numbers of T lymphocytes and macrophages; however, colon cancers contained a higher proportion of B cells. Leu7-positive NK/K cells were noted in small numbers in all tumors examined.     

Microbial diversity and activity in Southern California salterns and bitterns: analogues for remnant ocean worlds

Concurrent osmotic and chaotropic stress make MgCl₂-rich brines extremely inhospitable environments. Understanding the limits of life in these brines is essential to the search for extraterrestrial life on contemporary and relict ocean worlds, like Mars, which could host similar environments. We sequenced environmental 16S rRNA genes and quantified microbial activity across a broad range of salinity and chaotropicity at a Mars-analogue salt harvesting facility in Southern California, where seawater is evaporated in a series of ponds ranging from kosmotropic NaCl brines to highly chaotropic MgCl₂ brines. Within NaCl brines, we observed a proliferation of specialized halophilic Euryarchaeota, which corresponded closely with the dominant taxa found in salterns around the world. These communities were characterized by very slow growth rates and high biomass accumulation. As salinity and chaotropicity increased, we found that the MgCl₂-rich brines eventually exceeded the limits of microbial activity. We found evidence that exogenous genetic material is preserved in these chaotropic brines, producing an unexpected increase in diversity in the presumably sterile MgCl₂-saturated brines. Because of their high potential for biomarker preservation, chaotropic brines could therefore serve as repositories of genetic biomarkers from nearby environments (both on Earth and beyond) making them prime targets for future life-detection missions.     

Myostatin maps to the interval containing the bovine mh locus

Myostatin (GDF-8) is a member of the transforming growth factor-β superfamily and plays a role in muscle growth and development. Mice having targeted disruption of this gene display marked increases in muscle mass, a phenotype similar to the muscular hypertrophy (mh) in several cattle breeds. Physical mapping data developed from YAC clones indicate the bovine myostatin gene lies close to the centromere of bovine Chromosome (Chr) 2 (BTA2) at 2q11, indistinguishable from the cytogenetic location of the mh locus. In addition, a polymorphism in the second intron of the gene was used to show that myostatin maps within the interval previously shown to contain mh. These data suggest myostatin may be the gene causing muscular hypertrophy in cattle. Received: 19 June 1997 / Accepted: 2 July 1997