Variations in transforming growth factor beta in human milk are not related to levels in plasma

There is considerable variability in the concentrations of transforming growth factor beta (TGFbeta) in human milk from individual women which is not readily explained by maternal factors such as smoking or illness. A potential correlate is the maternal plasma level of TGFbeta since changes in plasma concentration of TGFbeta in response to a number of pathological conditions have been well documented. The purpose of this study was to investigate the relationship between the concentration of TGFbeta1 and TGFbeta2 in a single sample of human milk and plasma obtained on the same day from 80 lactating mothers at 5 weeks postpartum. The concentration of TGFbeta1 and TGFbeta2 in the aqueous fraction of human milk ranged from 228 to 3542 pg/ml (647, 438-799; median, 25th-75th percentiles) and 98 to 13 855 pg/ml (955, 535-1999) respectively and in paired samples of plasma from 440 to 19 460 (4026, 3245-6656) and 92 to 1739 (620, 391-925) respectively. Thus, in milk the median ratio of TGFbeta1 to TGFbeta2 was 1:1.6 whereas the corresponding median ratio in plasma was 7:1. There was no correlation between the concentration of either isoform of TGFbeta in milk and the corresponding TGFbeta in plasma.     

Male strategies and Plio-Pleistocene archaeology

Archaeological data are frequently cited in support of the idea that big game hunting drove the evolution of early Homo, mainly through its role in offspring provisioning. This argument has been disputed on two grounds: (1) ethnographic observations on modern foragers show that although hunting may contribute a large fraction of the overall diet, it is an unreliable day-to-day food source, pursued more for status than subsistence; (2) archaeological evidence from the Plio-Pleistocene, coincident with the emergence of Homo can be read to reflect low-yield scavenging, not hunting. Our review of the archaeology yields results consistent with these critiques: (1) early humans acquired large-bodied ungulates primarily by aggressive scavenging, not hunting; (2) meat was consumed at or near the point of acquisition, not at home bases, as the hunting hypothesis requires; (3) carcasses were taken at highly variable rates and in varying degrees of completeness, making meat from big game an even less reliable food source than it is among modern foragers. Collectively, Plio-Pleistocene site location and assemblage composition are consistent with the hypothesis that large carcasses were taken not for purposes of provisioning, but in the context of competitive male displays. Even if meat were acquired more reliably than the archaeology indicates, its consumption cannot account for the significant changes in life history now seen to distinguish early humans from ancestral australopiths. The coincidence between the earliest dates for Homo ergaster and an increase in the archaeological visibility of meat eating that many find so provocative instead reflects: (1) changes in the structure of the environment that concentrated scavenging opportunities in space, making evidence of their pursuit more obvious to archaeologists; (2) H. ergaster's larger body size (itself a consequence of other factors), which improved its ability at interference competition.     

The use of fluorescamine as a probe for labeling the outer surface of the plasma membrane

A rapid method was developed to label the outer surface of chick embryo fibroblasts with fluorescamine without disruption of the cell monolayer. Polyacrylamide gel electrophoresis resolved two distinct areas of fluorescence: a group of high molecular weight polypeptides and several rapidly migrating species. The latter were demonstrated by tlc to be phospholipids. Fluorescamine did not label internal components of the cell as evidenced by two intracellular proteins which were found to be non-fluorescent. Intact normal cells were labeled 3-fold more than transformed cells, indicating a possible loss of exposed sites at the surface, while disrupted cells, subsequently labeled, yielded similar amounts of fluorescence.     

Porphyra lilliputiana sp. nov. (Bangiales, Rhodophyta): A diminutive New Zealand endemic with novel reproductive biology

A new species of Porphyra, Porphyra lilliputiana, is described for the New Zealand region. This species is very small ([5] 10–20 [35] mm) and is found growing epiphytically, epilithically and epizoically on upper inter-tidal shores of moderate exposure. Field-collected material of P. lilliputiana possessed archeosporangia, endosporangia, spermatangia and zygotosporangia. In culture, archeospores vi/ere released and germinated to form thalli. Endosporangia either developed directly into thalli or released endospores which individually formed thalli. Zygotospores developed into the concho-celis phase, which formed conchosporangia. Released conchospores formed thalli. This species is distinguished by its small size, arrangement of reproductive cells, occurrence of endosporangia, dentate margin and habitat.     

Rhizobium (Sinorhizobium) meliloti phn Genes: Characterization and Identification of Their Protein Products

In Escherichia coli, the phn operon encodes proteins responsible for the uptake and breakdown of phosphonates. The C-P (carbon-phosphorus) lyase enzyme encoded by this operon which catalyzes the cleavage of C-P bonds in phosphonates has been recalcitrant to biochemical characterization. To advance the understanding of this enzyme, we have cloned DNA from Rhizobium (Sinorhizobium) meliloti that contains homologues of the E. coli phnG, -H, -I, -J, and -K genes. We demonstrated by insertional mutagenesis that the operon from which this DNA is derived encodes the R. meliloti C-P lyase. Furthermore, the phenotype of this phn mutant shows that the C-P lyase has a broad substrate specificity and that the organism has another enzyme that degrades aminoethylphosphonate. A comparison of the R. meliloti and E. coli phn genes and their predicted products gave new information about C-P lyase. The putative R. meliloti PhnG, PhnH, and PhnK proteins were overexpressed and used to make polyclonal antibodies. Proteins of the correct molecular weight that react with these antibodies are expressed by R. meliloti grown with phosphonates as sole phosphorus sources. This is the first in vivo demonstration of the existence of these hitherto hypothetical Phn proteins.     

Female subsistence strategies among Ache hunter-gatherers of Eastern Paraguay

Anthropologists have frequently proposed that sexual division of labor is produced by childcare constraints on women's subsistence work. We present data on the forest activities of Ache women that show that differences in parental investment partially account for variation in food acquisition among individual women. Data also suggest that childcare constraints are important in understanding the sexual division of labor.     

Molecular and genomic characterisation of a panel of human anal cancer cell lines

Anal cancer is a rare disease that has doubled in incidence over the last four decades. Current treatment and survival of patients with this disease has not changed substantially over this period of time, due, in part, to a paucity of preclinical models to assess new therapeutic options. To address this hiatus, we set-out to establish, validate and characterise a panel of human anal squamous cell carcinoma (ASCC) cell lines by employing an explant technique using fresh human ASCC tumour tissue. The panel of five human ASCC cell lines were validated to confirm their origin, squamous features and tumourigenicity, followed by molecular and genomic (whole-exome sequencing) characterisation. This panel recapitulates the genetic and molecular characteristics previously described in ASCC including phosphoinositide-3-kinase (PI3K) mutations in three of the human papillomavirus (HPV) positive lines and TP53 mutations in the HPV negative line. The cell lines demonstrate the ability to form tumouroids and retain their tumourigenic potential upon xenotransplantation, with varied inducible expression of major histocompatibility complex class I (MHC class I) and Programmed cell death ligand 1 (PD-L1). We observed differential responses to standard chemotherapy, radiotherapy and a PI3K specific molecular targeted agent in vitro, which correlated with the clinical response of the patient tumours from which they were derived. We anticipate this novel panel of human ASCC cell lines will form a valuable resource for future studies into the biology and therapeutics of this rare disease.Subject terms: Targeted therapies, Anal cancer, Immune evasion, Cancer models     

Observation of yeast cell movement and aggregation in a small-scale MHz-ultrasonic standing wave field

Aggregation of suspended yeast cells in a small-scale ultrasonic standing wave field has been monitored and quantified. The aggregation effect is based on the acoustic radiation force, which concentrates the cells in clumps. The ultrasonic chamber employed (1.9 MHz, one wavelength pathlength) had a sonication volume of 60 l. The aggregation process was observed from above the transducer through a transparent glass reflector. A distinct, reproducible, pattern of clumps formed rapidly in the sound field. The sound pressure was estimated experimentally to be of the order of 1 MPa. Microscopic observations of the formation of a single clump were recorded onto a PC. The time dependent movement patterns and travelling velocities of the cells during the aggregation process were extracted by particle image velocimetry analysis. A time dependent change was seen in the particle motion pattern during approach to its completion of clump formation after 45 s. Streaming eddies were set-up during the first couple of seconds. The scale of the eddies was consistent with Rayleigh micro-streaming theory. An increase in the travelling velocity of the cells was observed after 30 s from initially about 400 m s^–1 to about 1 mm s^–1. The influence of a number of mechanisms on particle behaviour (e.g. micro-streaming, particle interactions and convective flow) is considered. The experimental set-up introduced here is a powerful tool for aggregation studies in ultrasonic standing waves and lays the foundation for future quantitative experiments on the individual contributions of the different mechanisms.     

Observations on the ultrastructure of large cells associated with putative neoplastic disorders of mussels,Mytilus edulis,from Yaquina Bay,Oregon

Large cells, generally thought to be associated with neoplastic disorders in bivalve mollusks, were studied with the electron microscope. The atypical cells had an average diameter of 15 μm and a nuclear to cytoplasmic ratio of about 1–1.5. Nuclei were extensively pleomorphic and bizarre shapes were common. Nucleoli were prominent and often multiple. In the cytoplasm of the large cells, there was a wide range of variability in anomalous organelles. Two cell types were originally thought to exist; however, it is now thought that the two cell types represent the two extreme morphological expressions of a single cell line. Their varying appearance is correlated with the density of ribosomes and abundance of cellular organelles. The large Mytilus edulis cells possess many ultrastructural properties that are characteristic of certain malignant vertebrate cells. However, alternative explanations for their structure and function are also possible.