Chimpanzee facial symmetry: a biometric measure of chimpanzee health

This paper reports a study of fitness indicator theory in chimpanzees. First, it establishes a theoretical perspective for the study of fitness indicator theory and the relationships among indicators of fitness in humans and other animals. Second, it describes a methodology for assessing facial fluctuating asymmetry (FA) in a sample (N = 21) of zoo chimpanzees (Pan troglodytes). Third, associations among chimpanzee facial FA and health are described. FA was positively associated with negative health symptoms, and negatively associated with general health. Results are discussed under the framework of good genes theory.     

Neuronal Types in the Human Anterior Ventral Thalamic Nucleus: A Golgi Study

Neurons in the anterior ventral (AV) thalamic nucleus of human adults were impregnated by Golgi-Kopsch impregnation method. Results showed that at least three morphological types of neurons could be recognized in the human AV thalamic nucleus. Type I neurons were medium to large with rich dendritic arborization. Both tufted and radiating dendritic branching patterns were seen in almost every neuron of this type. Only the initial axonal segments of these cells were impregnated suggesting that these axons were heavily myelinated. Type II neurons were medium in size with poor to moderate dendritic arborization. Many of these cells possess a few dendritic grape-like appendages. Long segments (up to 300 μm) of their axons were impregnated suggesting that these axons were either unmyelinated or thinly myelinated. These axons change their direction and form loops very often. No local branches were seen for these axons suggesting that they could be projection axons. Type III neurons were small with only one or two dendrites with poor arborization. No axons for these cells were seen in this study. The three neuronal types in the human AV thalamic nucleus were compared with neuronal types already described in other thalamic nuclei of human and non-human species. The results of this study might provide a morphological basis for further electrophysiological and / or pathological studies.     

Things We Like: Human Preferences among Similar Organisms and Implications for Conservation

Human preferences will increasingly determine many species’ prospects for survival. However, aside from a small number of survey-based studies of preference among disparate taxa, human species preferences have received little attention. I determined human aesthetic preferences among a relatively homogenous group, the penguins, from representation in all recently published, comprehensive, popular books of photographs of penguins (n = 4 books; 304 photographs). Representation of visually distinguishable types of penguins, measured by total photograph area, was highly skewed and rankings were highly concordant across books, suggesting large and commonly held differences in aesthetic appeal. Multiple regression analysis indicated that amount of warm color was the only significant determinant of representation, and warm color was highly correlated (r ² = 0.96) with mean representation of the penguin types. Body size and neotenic form, traits found to influence human preferences among other animals, were not significant, suggesting that the bases of human species preferences differ by species type. The results of this study indicate that human aesthetic preferences discriminate finely among species and may be based on minor features. Conservationists must be vigilant to the potential for aesthetic responses to influence conservation efforts.     

Adenoviral transduction is more efficient in alginate-derived chondrocytes than in monolayer chondrocytes

Gene transfer into cultured chondrocytes by using adenoviral vectors has potential applications in treating cartilage disorders. The present study was undertaken to compare and optimize two chondrocyte culture conditions for adenoviral transduction efficacy by using primary human articular chondrocytes cultivated either directly in a monolayer condition or as outgrowths from alginate-stored chondrocyte cultures. Isolated primary chondrocytes from human articular cartilage were either immediately transduced with an EGFP (enhanced green fluorescent protein)-gene-bearing adenoviral vector (1,000 and 3,000 virus particles/cell) or cultured in alginate before transduction. Immunohistochemistry and flow cytometric analysis were employed to determine the expression of extracellular matrix proteins and of the αvβ5 integrin receptor involved in adenoviral cell entry. Monolayer chondrocytes exhibited moderate transduction rates (mean 22.2% and 46.9% EGFP-positive cells at 1,000 and 3,000 virus particles/cell by 72 h post-transduction), whereas alginate-derived chondrocytes revealed significantly higher transduction efficacies (95.7% and 99%). Both monolayer and alginate-derived chondrocytes expressed αvβ5 integrin, type II collagen and cartilage proteoglycans. The mean fluorescence intensity of type II collagen was significantly higher in the alginate-derived chondrocytes, whereas that of αvβ5 integrin was higher in the monolayer chondrocytes. Our results indicate that transduction efficacy is independent of αvβ5 integrin expression levels in chondrocytes. Moreover, adenoviral transduction of alginate-derived chondrocytes is more efficient than that for monolayer chondrocytes and may be a suitable tool to achieve sufficient numbers of transduced and differentiated chondrocytes for experimental applications and cartilage repair. Dr. Gundula Schulze-Tanzil is supported by a grant awarded by the Rahel Hirsh Foundation from the Charité Medical Schools Berlin. The study was supported by a grant from the Deutsche Arthrosehilfe e.V.     

Comparative characterization of pulmonary surfactant aggregates and alkaline phosphatase isozymes in human lung carcinoma tissue

Alkaline phosphatase (AP) isozymes are surfactant-associated proteins (SPs). Since several different AP isozymes have been detected in the pneumocytes of lung cancer patients, we attempted to identify the relationship between pulmonary surfactant aggregate subtypes and AP isozymes. Pulmonary surfactant aggregates were isolated from carcinoma and non-carcinoma tissues of patients with non-small cell carcinoma of the lung. Upon analysis, ultraheavy, heavy, and light surfactant aggregates were detected in the non-carcinoma tissues, but no ultraheavy surfactant aggregates were found in the carcinoma tissues. Surfactant-associated protein A (SP-A) was detected as two bands (a 27-kDa band and a 54-kDa band) in the ultraheavy, heavy, and light surfactant aggregates found in the non-carcinoma tissues. Although both SP-A bands were detected in the heavy and light surfactant aggregates from adenocarcinoma tissues, the 54-kDa band was not detected in squamous cell carcinoma tissues. Liver AP (LAP) was detected in the heavy and light surfactant aggregates from both non-carcinoma and squamous carcinoma tissues, but not in heavy surfactant aggregates from adenocarcinoma tissues. A larger amount of bone type AP (BAP) was found in light surfactant aggregate fractions from squamous cell carcinomas than those from adenocarcinoma tissues or non-carcinoma tissues from patients with either type of cancer. LAP, BAP, and SP-A were identified immunohistochemically in type II pneumocytes from non-carcinoma tissues and adenocarcinoma cells, but no distinct SP-A staining was observed in squamous cell carcinoma tissues. The present study has thus revealed several differences in pulmonary surfactant aggregates and AP isozymes between adenocarcinoma tissue and squamous cell carcinoma tissue.     

Bone marrow as a source of stem cells and germ cells? Perspectives for transplantation

Recent publications have suggested the existence of germ stem cells in the mouse at postnatal stages. The mechanism of de novo oocyte formation is proposed to involve a contribution from the bone marrow to the germ cell pool, via the bloodstream. Critical examination of the data underpinning these contentious claims is under way from a reproductive biology perspective but little has been said about the nature of this elusive bone marrow population with germ cell potential. Furthermore, whereas the prospect of marrow-derived germ cells may appear propitious for fertility applications, its wider impact on transplantation medicine remains to be considered. This paper examines the evidence leading to the current debate and considers the implications of such findings for the field of bone marrow transplantation. The author is indebted to the Anne McLaren Fellowship Scheme of the University of Nottingham and to the Alzheimer’s Society for their support.     

Effect of high oxygen on placental function in short-term explant cultures

Ex situ culture of human gestational tissues has been routinely used as a model to investigate tissue function. The objective of this study was to determine the effect of varying oxygen concentrations on human term placental explants over a 24-h time period. Specifically, the effect of incubating placental explants in oxygen concentrations of 8%, 21% or 95% on tissue viability, metabolism and cell death was measured by assessing glucose consumption, lactate production, release of lactate dehydrogenase, parathyroid hormone-related protein (PTHrP), tumour necrosis factor-alpha (TNF-α) and 8-isoprostane, immunoreactivity for cleaved-caspase-9 and immunohistochemistry for the caspase-3-cleaved cytokeratin-18 neoepitope, M30. Exposure to higher oxygen concentrations significantly increased the rates of glucose consumption and lactate production. Apoptosis was significantly increased under conditions of higher oxygen as evidenced by increased M30 in placental explant sections. Similarly, hyperoxia significantly increased the releases of PTHrP, TNF-α and 8-isoprostane. Thus, incubation of placental explants with oxygen concentrations of 95% and, to a lesser extent, 21% oxygen was associated with the modulation of multiple cellular response pathways including those associated with tissue viability and cell death. These data are consistent with the hypothesis that hyperoxia activates pathways and mechanisms involved in cellular metabolism, necrosis and apoptosis, thereby shifting the balance from a steady state towards cell death.     

A simple cell motility assay demonstrates differential motility of human periodontal ligament fibroblasts, gingival fibroblasts, and pre-osteoblasts

During periodontal regeneration, multiple cell types can invade the wound site, thereby leading to repair. Cell motility requires interactions mediated by integrin receptors for the extracellular matrix (ECM), which might be useful in guiding specific cell populations into the periodontal defect. Our data demonstrate that fibroblasts exhibit differential motility when grown on ECM proteins. Specifically, gingival fibroblasts are twice as motile as periodontal ligament fibroblasts, whereas osteoblasts are essentially non-motile. Collagens promote the greatest motility of gingival fibroblasts in the following order: collagen III>collagen V>collagen I. Differences in motility do not correlate with cell proliferation or integrin expression. Osteoblasts display greater attachment to collagens than does either fibroblast population, but lower motility. Gingival fibroblast motility on collagen I is generally mediated by α2 integrins, whereas motility on collagen III involves α1 integrins. Other integrins (α10 or α11) may also contribute to gingival fibroblast motility. Thus, ECM proteins do indeed differentially promote the cell motility of periodontal cells. Because of their greater motility, gingival fibroblasts have more of a potential to invade periodontal wound sites and to contribute to regeneration. This finding may explain the formation of disorganized connective tissue masses rather than the occurrence of the true regeneration of the periodontium. This research was supported by the Louisiana Board of Regents through the Millennium Trust Health Excellence Fund, HEF-(2000-05)-04.     

Costs versus benefits: best possible and best practical treatment regimens for HIV

Current HIV therapy, although highly effective, may cause very serious side effects, making adherence to the prescribed regimen difficult. Mathematical modeling may be used to evaluate alternative treatment regimens by weighing the positive results of treatment, such as higher levels of helper T cells, against the negative consequences, such as side effects and the possibility of resistance mutations. Although estimating the weights assigned to these factors is difficult, current clinical practice offers insight by defining situations in which therapy is considered “worthwhile”. We therefore use clinical practice, along with the probability that a drug-resistant mutation is present at the start of therapy, to suggest methods of rationally estimating these weights. In our underlying model, we use ordinary differential equations to describe the time course of in-host HIV infection, and include populations of both activated CD4⁺ T cells and CD8⁺ T cells. We then determine the best possible treatment regimen, assuming that the effectiveness of the drug can be continually adjusted, and the best practical treatment regimen, evaluating all patterns of a block of days “on” therapy followed by a block of days “off” therapy. We find that when the tolerance for drug-resistant mutations is low, high drug concentrations which maintain low infected cell populations are optimal. In contrast, if the tolerance for drug-resistant mutations is fairly high, the optimal treatment involves periods of reduced drug exposure which consequently boost the immune response through increased antigen exposure. We elucidate the dependence of the optimal treatment regimen on the pharmacokinetic parameters of specific antiviral agents.     

The effect of muscularity on thermal responses,muscle performance,and dexterity during whole body exposure to 10 °C

1.

The study evaluated the effects of exposure to cold air (10 °C) on thermal responses, muscle performance and dexterity of muscular subjects and their matched lean counterparts.