Effects of ovariectomy and tamoxifen on rat bone tissue: histomorphometric and histopathologic study

OBJECTIVE: To investigate possible detrimental effects on bone tissue induced by ovariectomy and tamoxifen (TMX) using bone densitometry and histomorphologic analysis. STUDY DESIGN: Twenty-four rats were allocated into 4 groups: group 1, intact normal rats (n = 6); group 2, ovariectomized rats (n = 6); group 3, normal female rats that received 1 mg/kg/day TMX dissolved in dimethyl sulfoxide (DMSO) for 2 months (n = 6); group 4, normal female rats that received DMSO for the same duration and with a volume equal to that of TMX (n = 6). Results of histomorphometric analysis for trabecular thickness, number of osteoblasts and osteoclasts, trabecular number, and area and cortical thickness were compared. RESULTS: No significant effects of ovariectomy on femoral or lumbar bone mineral density (BMD) were found. In the TMX group, the value of femoral BMD increased significantly compared to control group cellular and pathologic changes. TMX caused significant decrease in osteoblasts compared to the control group. CONCLUSION: TMX has a positive effect on inorganic bone tissue, but a negative effect on number of osteoblasts and osteoclasts. Future studies investigating estrogenic and antiestrogenic effects of TMX should include cellular parameters related to proliferation using histopathologic and histomorphometric analyses.     

Antimicrobial activity of catechol and pyrogallol as allelochemicals

Catechol and pyrogallol are allelochemicals which belong to phenolic compounds synthesized in plants. Their antimicrobial activities were investigated on three bacteria (Pseudomonas putida, Pseudomonas pyocyanea, Corynebacterium xerosis) and two fungi (Fusarium oxysporum, Penicillium italicum) phytopathogenic species as test organisms using the disc diffusion method. Both catechol and pyrogallol were found to have antibacterial effects on all the bacteria used in the study at 5 and 10 mM concentrations. Catechol has also been found to have an antifungal effect on the fungi used in the study, whereas no antifungal effects of pyrogallol were observed. The most sensitive species among the bacteria was P. putida which was inhibited by the allelochemicals even at 1 mM concentration.     

A practical validation approach for virus titer testing of avian infectious bursal disease live vaccine according to current regulatory guidelines

The method for virus titer determination of avian infectious bursal disease (IBD) live vaccine, developed long before regulatory validation guidelines is a cell culture based biological assay intended for use in vaccine release testing.The aim of our study was to perform a validation, based on fit-for-purpose principle, of an old 50% tissue culture infectious dose (TCID₅₀) method according to Guidelines of the International Cooperation on Harmonization of Technical Requirements for Registration of Veterinary Medicinal Products (VICH).This paper addresses challenges and discusses some key aspects that should be considered when validating biological methods. A different statistical approach and non-parametric statistics was introduced in validation protocol in order to derive useful information from experimental data. This approach is applicable for a wide range of methods.In conclusion, the previous virus titration method had showed to be precise, accurate, linear, robust and in accordance with current regulatory standards, which indicates that there is no need for additional re-development or upgrades of the method for its suitability for intended use.     

Estradiol protects adipose tissue-derived stem cells against H(2) O(2) -induced toxicity

Oxidative stress is associated with various pathophysiological processes, including cell survival, adhesion, apoptosis, and cancer. In the present study, we aimed to evaluate the effects of H₂O₂‐induced toxicity on adipose tissue–derived stem cells (ADSCs) and whether 17β‐estradiol (E₂) has protective effects on these cells. ADSCs derived from adult Sprague–Dawley rats were pretreated with different doses of E₂ for 24 h and then exposed to 200 µM H₂O₂ for 4 h. Incubation of ADSCs with H₂O₂‐decreased cell viability in a concentration‐dependent fashion (p < 0.0001), whereas pretreatment of these cells with E₂ significantly reversed toxicity (p < 0.05), inhibited apoptotic changes, and decreased lipid peroxidation (p < 0.0005). Our findings suggest that E₂ protects ADSCs from oxidative‐induced cell death, and therefore, it may be used to improve the survival rate and regenerative capacity of stem cells. © 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:301–307, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21421     

A Rhinocerotid Skull Cooked-to-Death in a 9.2 Ma-Old Ignimbrite Flow of Turkey

Background

Preservation of fossil vertebrates in volcanic rocks is extremely rare. An articulated skull (cranium and mandible) of a rhinoceros was found in a 9.2±0.1 Ma-old ignimbrite of Cappadocia, Central Turkey. The unusual aspect of the preserved hard tissues of the skull (rough bone surface and brittle dentine) allows suspecting a peri-mortem exposure to a heating source.

Methodology/Principal Findings

Here we describe and identify the skull as belonging to the large two-horned rhinocerotine Ceratotherium neumayri, well-known in the late Miocene of the Eastern Mediterranean Province. Gross structural features and microscopic changes of hard tissues (bones and teeth) are then monitored and compared to the results of forensic and archaeological studies and experiments focusing on heating effects, in order to reconstruct the hypothetical peri-mortem conditions. Macroscopic and microscopic structural changes on compact bones (canaliculi and lamellae vanished), as well as partial dentine/cementum disintegration, drastic enamel-dentine disjunctions or microscopic cracks affecting all hard dental tissues (enamel, cementum, and dentine) point to continued exposures to temperatures around 400–450°C. Comparison to other cases of preservation of fossil vertebrates within volcanic rocks points unambiguously to some similarity with the 79 AD Plinian eruption of the Vesuvius, in Italy.

Conclusions/Significance

A 9.2±0.1 Ma-old pyroclastic density current, sourced from the Çardak caldera, likely provoked the instant death of the Karacaşar rhino, before the body of the latter experienced severe dehydration (leading to the wide and sustainable opening of the mouth), was then dismembered within the pyroclastic flow of subaerial origin, the skull being separated from the remnant body and baked under a temperature approximating 400°C, then transported northward, rolled, and trapped in disarray into that pyroclastic flow forming the pinkish Kavak-4 ignimbrite ∼30 km North from the upper Miocene vent.     

Eicosanoids mediate melanotic nodulation reactions to viral infection in larvae of the parasitic wasp, Pimpla turionellae

Nodulation is the quantitatively predominant insect cellular immune function activated in response to bacterial, fungal and some viral infections. We posed the hypothesis that parasitoid insects express melanotic nodulation reactions to viral challenge and that eicosanoids mediate these reactions. Treating fifth-instar larvae of the ichneumonid endoparasitoid Pimpla turionellae with Bovine Herpes Simplex Virus-1 (BHSV-1) induced nodulation reactions in a challenge dose-dependent manner. Experimental larvae treated with the cyclooxygenase inhibitor, indomethacin, the lipoxygenase inhibitor, esculetin, and the phospholipase A2 inhibitor, dexamethasone, resulted in severely impaired nodulation reactions to our standard BHSV-1 challenge dose. The immunoinhibitory influence of dexamethasone was reversed in larvae reared on culture medium amended with arachidonic acid, the fatty acid precursor of eicosanoid biosynthesis. Larvae that had been reared on media amended with indomethacin, esculetin, or dexamethasone were also compromised in their nodulation reactions to viral challenge. The influence of the orally administered pharmaceutical was expressed in a dose-dependent manner. Finally, wasp larvae reared in the presence of indomethacin and dexamethasone expressed significantly decreased levels of phenoloxidase activity in response to viral challenge. These findings draw attention to the idea that endoparasitoid insects express cellular immune reactions to viral challenge; they also support our hypothesis that eicosanoids mediate nodulation reactions to viral challenge in these highly specialized insects.     

Feature identification in circadian rhythms of mice strains using in vivo information

The objective of this work was to identify strain-specific characteristics from real-time measurements of circadian rhythms of two inbred mouse strains. In particular, heart rate, temperature, and activity data collected from A/J and C57BL/6J (B6) mice using telemetry are analyzed. The influence of activity on heart rate and temperature is minimized by correlation analysis followed by regression analysis. The correlation analysis is used to determine the length of the activity data filter that results in the best correlation between activity data and heart rate or temperature. After the activity data are filtered, they are used in regression analysis. The temperature and heart rate rhythms obtained as the intercepts of the regression analysis are interpreted as the zero-activity rhythms and consequently are good estimates of the circadian rhythms. The circadian temperature rhythms for the B6 mice follow a smoother cosine-like time waveform, whereas those for the A/J mice follow a more square-wave-like waveform. To quantify the difference between these two temperature rhythms, a feature based on Fourier analysis of the time-series data is used. Detrended fluctuation analysis is used to identify features in the heart rate rhythms. The results of this work show that the features for the circadian temperature and heart rate rhythms can be used as distinguishing characteristics of the A/J and B6 strains. This work provides the foundation for future studies directed at investigating the influence of chromosomal substitutions on the regulation of circadian rhythms in these two strains.     

NK cell-mediated targeting of human cancer and possibilities for new means of immunotherapy

Insights into the molecular basis for natural killer (NK) cell recognition of human cancer have been obtained in recent years. Here, we review current knowledge on the molecular specificity and function of human NK cells. Evidence for NK cell targeting of human tumors is provided and new strategies for NK cell-based immunotherapy against human cancer are discussed. Based on current knowledge, we foresee a development where more cancers may be subject to treatment with drugs or other immunomodulatory agents affecting NK cells, either directly or indirectly. We also envisage a possibility that certain forms of cancers may be subject to treatment with adoptively transferred NK cells, either alone or in combination with other therapeutic interventions.     

Heterogeneous transmural proteoglycan distribution provides a mechanism for regulating residual stresses in the aorta

The arterial wall contains a significant amount of charged proteoglycans, which are inhomogeneously distributed, with the greatest concentrations in the intimal and medial layers. The hypothesis of this study is that the transmural distribution of proteoglycans plays a significant role in regulating residual stresses in the arterial wall. This hypothesis was first tested theoretically, using the framework of mixture theory for charged hydrated tissues, and then verified experimentally by measuring the opening angle of rat aorta in NaCl solutions of various ionic strengths. A three-dimensional finite element model of aortic ring, using realistic values of the solid matrix shear modulus and proteoglycan fixed-charge density, yielded opening angles and changes with osmolarity comparable to values reported in the literature. Experimentally, the mean opening angle in isotonic saline (300 mosM) was 15 +/- 17 degrees and changed to 4 +/- 19 degrees and 73 +/- 18 degrees under hypertonic (2,000 mosM) and hypotonic (0 mosM) conditions, respectively (n = 16). In addition, the opening angle in isotonic (300 mosM) sucrose, an uncharged molecule, was 60 +/- 16 degrees (n = 11), suggesting that the charge effect, not cellular swelling, was the major underlying mechanism for these observations. The extent of changes in opening angle under osmotic challenges suggests that transmural heterogeneity of fixed-charge density plays a crucial role in governing the zero-stress configuration of the aorta. A significant implication of this finding is that arterial wall remodeling in response to altered wall stresses may occur via altered deposition of proteoglycans across the wall thickness, providing a novel mechanism for regulating mechanical homeostasis in vascular tissue.     

Differential distribution of aldolase A and C in the human central nervous system

We have analyzed the distribution of aldolase A and C mRNAs and proteins in various areas of the human brain using Northern blot analyses and immunohistochemistry. Aldolase A mRNA expression was higher than aldolase C mRNA expression in all areas of the brain examined. Aldolase C mRNA expression was highest in the cerebellum. Aldolase C protein was present in well-delimited regions of the CNS, and was distributed in stripes in the Purkinje cell layer of the cerebellum, in the inferior olives and in the sensory neurons of the posterior horn of the spinal cord. The novel finding of aldolase C in well-delimited cell compartments of the human cerebellum and in several other areas of the CNS lends weight to the hypothesis that this protein exerts other functions (e.g. sensory transmission) besides those characteristic of a glycolytic enzyme.