Spontaneous cardiomyopathy resembling acute rheumatic heart disease in an owl monkey.

A wild-caught male Aotus vociferans died spontaneously during quarantine. Histologic examination of the heart showed several small myocardial arteries replaced with fibrinoid necrosis and adjacent inflammation that included lymphocytes and large histiocytic cells. Less often, similar inflammatory foci were observed in the myocardium interstitium. The lesions observed in the heart of the owl monkey resembled Aschoff bodies.     

The effect of dopaminergic blockade on thyrotrophin response to thyrotrophin-releasing hormone and somatostatin

Using a large number of animals we have been able to demonstrate that somatostatin administration (20 micrograms/100 g bw) significantly reduces both basal serum thyrotrophin (TSH) levels and the response to thyrotrophin-releasing hormone (TRH) in the normal rat. Pretreatment with the dopaminergic antagonist domperidone resulted in increased TSH levels, increased response to TRH but no modification in the response to somatostatin.     

Intraspecific diversity loss in a predator species alters prey community structure and ecosystem functions

Loss in intraspecific diversity can alter ecosystem functions, but the underlying mechanisms are still elusive, and intraspecific biodiversity–ecosystem function (iBEF) relationships have been restrained to primary producers. Here, we manipulated genetic and functional richness of a fish consumer (Phoxinus phoxinus) to test whether iBEF relationships exist in consumer species and whether they are more likely sustained by genetic or functional richness. We found that both genotypic and functional richness affected ecosystem functioning, either independently or interactively. Loss in genotypic richness reduced benthic invertebrate diversity consistently across functional richness treatments, whereas it reduced zooplankton diversity only when functional richness was high. Finally, losses in genotypic and functional richness altered functions (decomposition) through trophic cascades. We concluded that iBEF relationships lead to substantial top-down effects on entire food chains. The loss of genotypic richness impacted ecological properties as much as the loss of functional richness, probably because it sustains “cryptic” functional diversity.

Global change is expected to generate a loss of intraspecific diversity worldwide. This mesocosm study explores whether loss of genetic and functional diversity in a predator species affects community and ecosystem functioning of lower trophic levels in pond ecosystems, revealing that diversity loss in a single consumer species can impact an entire ecosystem, reducing its functionality.     

The actions of phenol and pentachlorophenol (PCP) on axonal conduction, ganglionic synaptic transmission, and the effect of pH changes

1. A comparison of phenol, pentachlorophenol (PCP) and procaine effects on axonal conduction were studied in vitro in the sciatic nerves of toad. PCP and procaine were respectively 6.3 and 3.15 times more potent than phenol in blocking axonal conduction. 2. Effects of PCP on synaptic transmission were studied in vitro in the eighth sympathetic ganglion of toad. 3. Axonal conduction block and synaptic transmission block by phenol was reversible, but not that by PCP. 4. When the PCP ionization was increased, a lesser per cent reached the site of action, reducing its capacity to block the axonal conduction and ganglionic transmission. 5. PCP plus, 3,4-Diaminopyridine (3,4-DAP) decreased synaptic transmission block from post-ganglionic compound action potential (CAP) responses to supramaximal preganglionic stimulation.     

Influence of branched-chain amino acid composition of culture media on the synthesis of plasma proteins by serum-free cultured rat hepatocytes

Summary Supplementation of Ham's F12 culture medium with essential amino acids (EAA) up to the rat plasma levels increased the rates of synthesis of albumin and transferrin by cultured rat hepatocytes by 1.3 and 1.7, respectively. Fifty percent of this increase could be attributed to three of the EAA: the branched-chain amino acids (BCAA: Leu Ile and Val). Non-branched-chain essential amino acids (non-BC-EAA) stimulated only 25% of the increase produced by the whole EAA mixture. When each EAA was tested individually, none of them caused an appreciable increase in albumin and transferrin in culture medium. When the concentrations of all EAA were raised to rat postprandial portal levels, albumin and transferrin synthesis rates reached a maximum, increasing by 3.2 and 3.5, respectively. Supplementation with BCAA at postprandial portal concentrations increased albumin and transferrin synthesis rates by 2.2 and 2.0, respectively, and had no noteworthy effect on the synthesis of cellular proteins. Non-BC-EAA at their postprandial portal concentrations increased albumin and transferrin synthesis rates by 1.7 and 1.9, respectively. Supplementation with alanine to reach a nitrogen content equal to that of the modified EAA-enriched medium had no stimulatory effect. Our results show that EAA have a specific effect on the synthesis of plasma proteins by cultured hepatocytes, and that BCAA at physiologic concentrations account for the major part of this stimulatory effect. Consequently, EAA and particularly BCAA concentration should be elevated in serum-free nutrient media to sustain maximum plasma protein synthesis.     

AChemS: the beginning. Association for Chemoreception Sciences

This paper unfolds the events, the people and the times that led up to the founding of AChemS and fashioned its character during its early formative years. It describes the path over which AChemS came, going from the original assertions and denials for the need of such an organization to its later inception and nascent development. This narration highlights such topics as the debate over the need for AChemS, the role of National Science Foundation in the founding of AChemS, the derivation of the Association's name, the choice of Sarasota and the Hyatt House as the meeting site, the generation of the programs for the early annual meetings, the adoption of the bylaws, the process of incorporation and tax deferment, and the birth of the Givaudan Lectureship. Most emphatically highlighted, however, is the enthusiasm, commitment and hard work that the members of the chemosensory research community displayed in bringing AChemS to fruition.