Protein synthesis patterns in barley embryos during germination

Summary The incorporation pattern of [¹⁴C] amino-acid into protein during the first 8 h of germination in isolated barley embryos (Hordeum vulgare) is described. Two maxima were recognised. The first, at 4 h, was entirely accounted for by scutellum activity and the second, at 8 h, coincided with active radicle elongation. An intervening minimum was situated at 5.5 h. The first peak was insensitive to actinomycin-D but the second showed a partial inhibition by this compound. Only slight changes in enzyme activity were associated with these periods of increased synthesis. Incorporation of [17-¹⁴C] kaurenoic acid into compounds co-chromatographing with gibberellins was followed over the same period in both embryos and scutella and high activity was found after only 2–4 h. It is concluded that, on the basis of protein synthetic activity, the scutellum is the most probable source of the initial gibberellin stimulus.     

Quantitative patterns of Hsps in tubular adenoma compared with normal and tumor tissues reveal the value of Hsp10 and Hsp60 in early diagnosis of large bowel cancer

Large bowel carcinogenesis involves accumulation of genetic alterations leading to transformation of normal mucosa into dysplasia and, lastly, adenocarcinoma. It is pertinent to elucidate the molecular changes occurring in the pre-neoplastic lesions to facilitate early diagnosis and treatment. Heat shock proteins (Hsps), many of which are molecular chaperones, are implicated in carcinogenesis, and their variations with tumor progression encourage their study as biomarkers. There are many reports on Hsps and cancer but none to our knowledge on their systematic quantification in pre-neoplastic lesions of the large bowel. We performed immunohistochemical determinations of Hsp10, Hsp60, Hsp70, and Hsp90 in biopsies of large bowel tubular adenomas with moderate grade of dysplasia and compared to normal mucosa and adenocarcinoma with a moderate grade of differentiation (G2). A significant elevation of Hsp10 and Hsp60 only, i.e., in the absence of elevation of Hsp70 or Hsp90, in both epithelium and lamina propria was found in tubular adenoma by comparison with normal mucosa. In contrast, adenocarcinoma was characterized by the highest levels of Hsp10 and Hsp60 in epithelium and lamina propria, accompanied by the highest levels of Hsp70 only in epithelium and of Hsp90 only in lamina propria, by comparison with normal and tubular adenoma counterparts. Hsp10 and Hsp60 are promising biomarkers for early diagnosis of tubular adenoma and for its differentiation from more advanced malignant lesions. Hsp10 and Hsp60 may be implicated in carcinogenesis from its very early steps and, thus, are potentially convenient targets for therapy.     

Delayed blockade of the kinin B1 receptor reduces renal inflammation and fibrosis in obstructive nephropathy

Renal fibrosis is the common histological feature of advanced glomerular and tubulointerstitial disease leading to end-stage renal disease (ESRD). However, specific antifibrotic therapies to slow down the evolution to ESRD are still absent. Because persistent inflammation is a key event in the development of fibrosis, we hypothesized that the proinflammatory kinin B1 receptor (B1R) could be such a new target. Here we show that, in the unilateral ureteral obstruction model of renal fibrosis, the B1R is overexpressed and that delayed treatment with an orally active nonpeptide B1R antagonist blocks macrophage infiltration, leading to a reversal of the level of renal fibrosis. In vivo bone marrow transplantation studies as well as in vitro studies on renal cells show that part of this antifibrotic mechanism of B1R blockade involves a direct effect on resident renal cells by inhibiting chemokine CCL2 and CCL7 expression. These findings suggest that blocking the B1R is a promising antifibrotic therapy.     

The cellular prion protein and its role in Alzheimer disease

The cellular prion protein (PrP^C) is a membrane-bound glycoprotein especially abundant in the central nervous system (CNS). The scrapie prion protein (PrP^Sc, also termed prions) is responsible of transmissible spongiform encephalopathies (TSE), a group of neurodegenerative diseases which affect humans and other mammal species, although the presence of PrP^C is needed for the establishment and further evolution of prions.The present work compares the expression and localization of PrP^C between healthy human brains and those suffering from Alzheimer disease (AD).In both situations we have observed a rostrocaudal decrease in the amount of PrP^C within the CNS, both by immunoblotting and immunohistochemistry techniques. PrP^C is higher expressed in our control brains than in AD cases. There was a neuronal loss and astogliosis in our AD cases. There was a tendency of a lesser expression of PrP^C in AD cases than in healthy ones. And in AD cases, the intensity of the expression of the unglycosylated band is higher than the di- and monoglycosylated bands.With regards to amyloid plaques, those present in AD cases were positively labeled for PrP^C, a result which is further supported by the presence of PrP^C in the amyloid plaques of a transgenic line of mice mimicking AD.The work was done according to Helsinki Declaration of 1975, and approved by the Ethics Committee of the Faculty of Medicine of the University of Navarre.Key words: cellular prion protein, Alzheimer disease, transgenic mice     

Whole Cell Patch Clamp for Investigating the Mechanisms of Infrared Neural Stimulation

It has been demonstrated in recent years that pulsed, infrared laser light can be used to elicit electrical responses in neural tissue, independent of any further modification of the target tissue. Infrared neural stimulation has been reported in a variety of peripheral and sensory neural tissue in vivo, with particular interest shown in stimulation of neurons in the auditory nerve. However, while INS has been shown to work in these settings, the mechanism (or mechanisms) by which infrared light causes neural excitation is currently not well understood. The protocol presented here describes a whole cell patch clamp method designed to facilitate the investigation of infrared neural stimulation in cultured primary auditory neurons. By thoroughly characterizing the response of these cells to infrared laser illumination in vitro under controlled conditions, it may be possible to gain an improved understanding of the fundamental physical and biochemical processes underlying infrared neural stimulation.     

Plasma testosterone concentration, body weight, social dominance and scent-marking in male marsupial sugar gliders (Petaurus breviceps; Marsupialia: Petauridae)

Observations were made of a wild population of sugar gliders ( Petaurus breviceps ) by live-trapping and on four captive colonies to establish the relationship between blood concentration of testosterone, body weight, social dominance and the timing of births. In both the wild and in captivity one male exhibits a testosterone concentration far higher than his fellows, during the breeding season. This male is also the heaviest. In captivity this male is observed to be socially the most dominant and undertakes almost all of the scent-marking. At least three-quarters of each breeding season's births occur during the first month of the three- to four-month season (July-September/October), a passage of time during which the body weight of the most dominant male falls more than that of the subordinates. It is suggested that this species is highly polygynous, with the ecological and evolutionary benefits of high social status being immense.