Isolation of glutathione from bovine thymus and its significance to research relevant to immune systems

A peptide was isolated from bovine thymus when a cAMP assay guided fractionation; it was glutathione. Pure glutathione (isolated and purchased) at 1, 10, 20, 40 and 100 μg/ml was active, P<0.05–0.01, in the cAMP assay. Glutathione was not active in the mixed lymphocyte culture assay, but was active in assays using T-rosettes. Glutathione may now be separated to avoid its biological interference in assays guiding fractionation to a thymic hormone(s). It is credible that glutathione was in fractions studied biologically and clinically by others. Knowing that glutathione may function in the transport of amino acids across membranes, and that L-alanine is essential for human lymphocytes to respond to mitogenic and allogenic stimulation, it seems possible that glutathione might be functional in the complex immune systems.     

Post‐fire pickings: Large herbivores alter understory vegetation communities in a coastal eucalypt forest

Fire and herbivores alter vegetation structure and function. Future fire activity is predicted to increase, and quantifying changes in vegetation communities arising from post‐fire herbivory is needed to better manage natural environments. We investigated the effects of post‐fire herbivory on understory plant communities in a coastal eucalypt forest in southeastern Australia. We quantified herbivore activity, understory plant diversity, and dominant plant morphology following a wildfire in 2017 using two sizes of exclosures. Statistical analysis incorporated the effect of exclusion treatments, time since fire, and the effect of a previous prescribed burn. Exclusion treatments altered herbivore activity, but time since fire did not. Herbivory reduced plant species richness, diversity, and evenness and promoted the dominance of the most abundant plants within the understory. Increasing time since fire reduced community diversity and evenness and influenced morphological changes to the dominant understory plant species, increasing size and dead material while decreasing abundance. We found the legacy effects of a previous prescribed burn had no effect on herbivores or vegetation within our study. Foraging by large herbivores resulted in a depauperate vegetation community. As post‐fire herbivory can alter vegetation communities, we postulate that management burning practices may exacerbate herbivore impacts. Future fire management strategies to minimize herbivore‐mediated alterations to understory vegetation could include aggregating management burns into larger fire sizes or linking fire management with herbivore management. Restricting herbivore access following fire (planned or otherwise) can encourage a more diverse and species‐rich understory plant community. Future research should aim to determine how vegetation change from post‐fire herbivory contributes to future fire risk.     

Phagocytic activity of alveolar macrophages in patients with bronchogenic carcinoma

Summary Human bronchoalveolar cells were obtained by lavage during diagnostic fiberoptic bronchoscopy of 21 patients suspected of having lung malignancies. Of these patients 11 were diagnosed as having primary lung cancer (Group I) and included individuals with squamous cell carcinoma, adenocarcinoma, undifferentiated large and oat cell carcinoma at varying locations and TNM stages, 4 patients demonstrated nonprimary metastatic carcinoma (Group II), and 6 patients did not reveal detectable tumors by bronchoscopy or follow-up (Group III) and were included as study controls. We examined the ability of pulmonary alveolar macrophages (PAMs) lavaged from patients in each of the three study groups to phagocytose opsonized sheep red blood cells. Phagocytic activity varied among patients in the same and different study groups; however, no significant differences were observed in the phagocytic or tumoristatic activities of PAMs recovered from tumor-bearing and nontumor-bearing lung regions of the same patient. Moreover, lavage fluids collected from tumor-bearing regions did not suppress the phagocytic activity of PAMs collected from control lungs nor lung regions contralateral to the tumor-bearing lung. The data do not support the view that bronchial neoplasms or their secreted products suppress phagocytic functions of alveolar macrophages.     

Neuronal nAChR stereoselectivity to non-natural epibatidine derivatives

The frog toxin epibatidine is one of the most powerful ligands of the neuronal nicotinic receptors and derivatives show promising possibilities for labeling in positron emission tomography studies. In an attempt to reduce epibatidine toxicity, new methyl derivatives were synthesized, tested in positron emission tomography imaging and in electrophysiology. labeling as well as physiological experiments highlighted the differences in sensitivity of the neuronal nicotinic acetylcholine receptors between two methyl enantiomers and the reduction in sensitivity caused by introducing the methyl group. At present, epibatidine derivatives seem the most promising compounds for in vivo labeling of neuronal nicotinic acetylcholine receptors.     

NewProconsul (Xenopithecus) from the Miocene of Kenya

A maxillary fragment with M^2–3 from the middle Miocene of Lothidok Hill, northwestern Kenya represents a new species ofProconsul—the typical East African early and middle Miocene hominoid species group. M² inProconsul (Xenopithecus)hamiltoni sp. nov. is about 50% larger than in Kenyan lower MioceneP. (X.)koruensis. Xenopithecus is revived as a subgenus ofProconsul because its species are less derived than typical species of that genus in having small—unexpanded—trigons, in possessing an M² with a significantly lower relative length, and in lacking a hypocone and large metacone on M³; however, xenopithecines share with proconsulines welldefined trigon ridges on M^1–3, large hypocones on M^1–2, greater relative height of M^2–3, and crenulated cingula on M^1–3 four character complexes derived over those of plesiomorphous East African early and middle MioceneLimnopithecus. An upper canine from Lothidok Hill represents a second species ofProconsul, P. (Proconsul)major. This identification confirms earlier records of that species from Lothidok.