STUDIES ON MYCOBACTERIA: I. CYTOCHEMICAL STUDY AND CHEMICAL ANALYSIS OF THE LIPIDS OF MYCOBACTERIUM MARIANUM

1956 ◽  
Vol 2 (7) ◽  
pp. 685-701 ◽  
Author(s):  
Soeur Marie Suzanne ◽  
V. Portelance ◽  
M. Panisset

Several authors have reported that the composition of the lipids of the tubercle bacillus varies with the type and composition of the culture media. Major differences may therefore exist between the bacillary lipids of bacilli growing on culture media and those of such microorganisms parasitizing a host.The present paper deals with the cytochemical and chemical analyses of Mycobacterium marianum, which is, to our knowledge, the first strain of Mycobacterium to be stained by the Sudan black B method when grown on Sauton's medium. Details on the isolation and fractionation of several lipid fractions of Mycobacterium marianum are presented together with some of their properties. The results are discussed in relation to our working hypothesis that the chemical composition of Mycobacterium marianum grown under our conditions may resemble more closely that of bacilli growing in vivo than do most cultured mycobacteria.

1970 ◽  
Vol 37 (292) ◽  
pp. 909-915
Author(s):  
C. Frick

SummaryA glass-bearing dolerite, which consists of orthopyroxene phenocrysts (γ 1·689, α 1·678, β 1·680, 2Vα 81°, S.G. 3·35) and a glassy mesostasis (n 1·568, S.G. 3·25), is described petrologically. Three new chemical analyses are given. From the petrological and chemical data it can be concluded that the orthopyroxene formed under intratelluric conditions and probably under high pressure. According to the recalculated chemical analysis of the orthopyroxene 0·22 Al3+ is in the Y position and much less Al3+ in the Z position. The chemical analysis of the residual glass is compared with similar residual glasses, and it shows that iron enrichment characterizes the earlier stages of crystallization differentiation, whereas the later stages are marked by an increase in Si4+, K+, and Na+.


1983 ◽  
Vol 31 (2) ◽  
pp. 307-317 ◽  
Author(s):  
S K Aggarwal ◽  
I Niroomand-Rad

To study the effects of cisplatin [cis-dichlorodiammine-platinum (II)] on tumor cells in the presence or absence of the immune system, animals with ascites sarcoma-180 tumor burden were treated with therapeutic dose levels (9 mg/kg). Similarly, ascites sarcoma-180 cells were maintained in tissue culture media containing the same levels of the drug. Cell samples were taken from the animals at 12-hr intervals for 3 days, whereas samples were drawn from the tissue cultures at 15-, 30-, 45-, and 60-min and at 2-, 3-, 4-, and 5-hr intervals. Treated and untreated cells from in vitro and in vivo experiments, when checked for alkaline phosphatase, 5'-nucleotidase, Ca2+-ATPase, and Na+-K+-ATPase, show a gradual decrease in activity on the plasma membrane. It takes about 60 min for inactivation of any enzyme in vitro, whereas it takes 2 days in in vivo experiments. Quantitative analysis show alkaline phosphatase activity drops from 9.7 to 4.9 nmol in just 15 min, and drops further to 0.79 nmol after 2 hr. Inactivation of various plasma membrane enzymes, resulting in permeability changes, is probably responsible for cell death.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


Author(s):  
W.A. Jacob ◽  
R. Hertsens ◽  
A. Van Bogaert ◽  
M. De Smet

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.


Author(s):  
Baljit Singh

The PIM of sheep, calf, goat and horse has a characteristic ultrastructural feature in the form of a unique, heparin sensitive, globular surface coat present around the plasma membrane with an intervening electron lucent space of 32-40 nm. We previously showed the active involvement of this surface coat in the phagocytosis of tracer material like monastral blue and cationized ferritin. The surface coat is capable of reconstitution in vivo following disruption with heparin. The present study was aimed to investigate whether PIM is the source of surface coat or not. In the recent years the BFA has been extensively used to understand the secretory pathways in the cells because of its ability to cause a rapid and reversible block to the anterograde transport of proteins from the endoplasmic reticulum to the Golgi.Sheep (n=6) were weighed, their plasma volume was calculated indirectly and based on which a sufficient single intravenous dose of BFA was given so as to reach a concentration of 4-5 microgram/ml of plasma.


2020 ◽  
Author(s):  
K. Zerrouki ◽  
N. Djebli ◽  
L. Gadouche ◽  
I. Erdogan Orhan ◽  
F. SezerSenol Deniz ◽  
...  

Nowadays, because of the industrialization, a lot of contaminant were available ; the consequences of this availability are apparition of diseases including neurodegeneration. Neurodegenerative diseases of the human brain comprise a variety of disorders that affect an increasing percentage of the population. This study is based on the effect of the Boswellic resin, which is from a medicinal plant and known for its antioxidant effects on nerve cell damage. The objective of this work was to evaluate the in vitro and in vivo effects of the Boswellic resin on anticholinesterase activity and Alzheimer’s disease (AD) induced by D-galactose and aluminum tetrachloride in Swiss mice. Chemical composition of the resin essential oil was identified by the CG-MS analysis. The antioxidant activity was also assessed by the DMPD and metal chelation methods. In order to understand the mechanism of memory improvement, the acetylcholinesterase, AChE, and butyrylcholinesterase, BChE, inhibitory assays were performed. In vivo part of the study was achieved on Swiss mice divided into four groups: control, AD model, treated AD, and treated control group. The identification of chemical composition by CG-MS reach the 89.67% of the total extract compounds presented some very important molecules (p-Cymene, n-Octyl acetate, α-Pinene…). The present study proves that Boswellic resin improves memory and learning in treated Alzheimer’s group, modulates the oxidative stress and be involved in the protective effect against amyloid deposition and neurodegeneration, and stimulates the immune system in mice’s brain.


Author(s):  
A. B. Edwards

During a petrological examination of samples of bauxite from Boolarra, in south Gippsland, Victoria, it was noted that some specimens of the bauxite, which is largely derived from Tertiary olivine-basalt, contained numerous grains of yellow-brown to amber-yellow leucoxene. The leucoxene is clearly pseudo-morphous after ilmenite, residual particles of ilmenite being enclosed in many of the leucoxene grains. Most of the leucoxene grains are opaque, but occasional grains are translucent to transparent, though isotropic. Some of them show parallel markings suggestive of cleavage, but probably a residual structure from the replaced ilmenite. In view of the highly aluminous nature of the enclosing rock, there seemed some possibility that this mineral might be the little-known aluminium titanate, xanthitane. It was thought, therefore, that if a pure sample of the mineral could be prepared, a chemical analysis would establish its identity.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1611
Author(s):  
Caroline J. Harrison ◽  
Paul V. Hatton ◽  
Piergiorgio Gentile ◽  
Cheryl A. Miller

Injectable nanoscale hydroxyapatite (nHA) systems are highly promising biomaterials to address clinical needs in bone tissue regeneration, due to their excellent biocompatibility, bioinspired nature, and ability to be delivered in a minimally invasive manner. Bulk strontium-substituted hydroxyapatite (SrHA) is reported to encourage bone tissue growth by stimulating bone deposition and reducing bone resorption, but there are no detailed reports describing the preparation of a systematic substitution up to 100% at the nanoscale. The aim of this work was therefore to fabricate systematic series (0–100 atomic% Sr) of SrHA pastes and gels using two different rapid-mixing methodological approaches, wet precipitation and sol-gel. The full range of nanoscale SrHA materials were successfully prepared using both methods, with a measured substitution very close to the calculated amounts. As anticipated, the SrHA samples showed increased radiopacity, a beneficial property to aid in vivo or clinical monitoring of the material in situ over time. For indirect methods, the greatest cell viabilities were observed for the 100% substituted SrHA paste and gel, while direct viability results were most likely influenced by material disaggregation in the tissue culture media. It was concluded that nanoscale SrHAs were superior biomaterials for applications in bone surgery, due to increased radiopacity and improved biocompatibility.


Horticulturae ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 195
Author(s):  
Alla A. Shulgina ◽  
Elena A. Kalashnikova ◽  
Ivan G. Tarakanov ◽  
Rima N. Kirakosyan ◽  
Mikhail Yu. Cherednichenko ◽  
...  

We investigated the influence of different conditions (light composition and plant growth regulators (PGRs) in culture media) on the morphophysiological parameters of Stevia rebaudiana Bertoni in vitro and in vivo. Both PGRs and the light spectra applied were found to significantly affect plant morphogenesis. During the micropropagation stage of S. rebaudiana, optimal growth, with a multiplication coefficient of 15, was obtained in an MS culture medium containing 2,4-epibrassinolide (Epin) and indole-3-acetic acid (IAA) at concentrations of 0.1 and 0.5 mg L−1, respectively. During the rooting stage, we found that the addition of 0.5 mg L−1 hydroxycinnamic acid (Zircon) to the MS medium led to an optimal root formation frequency of 85% and resulted in the formation of strong plants with well-developed leaf blades. Cultivation on media containing 0.1 mg L−1 Epin and 0.5 mg L−1 IAA and receiving coherent light irradiation on a weekly basis resulted in a 100% increase in the multiplication coefficient, better adventitious shoot growth, and a 33% increase in the number of leaves. S. rebaudiana microshoots, cultured on MS media containing 1.0 mg L−1 6-benzylaminopurine (BAP) and 0.5 mg L−1 IAA with red monochrome light treatments, increased the multiplication coefficient by 30% compared with controls (white light, media without PGRs).


2016 ◽  
Vol 38 (3) ◽  
pp. 859-870 ◽  
Author(s):  
Mingfeng He ◽  
Hongquan Dong ◽  
Yahui Huang ◽  
Shunmei Lu ◽  
Shu Zhang ◽  
...  

Background/Aims: Microglia are an essential player in central nervous system inflammation. Recent studies have demonstrated that the astrocytic chemokine, CCL2, is associated with microglial activation in vivo. However, CCL2-induced microglial activation has not yet been studied in vitro. The purpose of the current study was to understand the role of astrocyte-derived CCL2 in microglial activation and to elucidate the underlying mechanism(s). Methods: Primary astrocytes were pre-treated with CCL2 siRNA and stimulated with TNF-α. The culture medium (CM) was collected and added to cultures of microglia, which were incubated with and without CCR2 inhibitor. Microglial cells were analyzed by quantitative RT-PCR to determine whether they polarized to the M1 or M2 state. Microglial migratory ability was assessed by transwell migration assay. Results: TNF-α stimulated the release of CCL2 from astrocytes, even if the culture media containing TNF-α was replaced with fresh media after 3 h. CM from TNF-α-stimulated astrocytes successfully induced microglial activation, which was ascertained by increased activation of M1 and enhanced migration ability. In contrast, CM from astrocytes pretreated with CCL2 siRNA showed no effect on microglial activation, compared to controls. Additionally, microglia pre-treated with RS102895, a CCR2 inhibitor, were resistant to activation by CM from TNF-α-stimulated astrocytes. Conclusion: This study demonstrates that the CCL2/CCR2 pathway of astrocyte-induced microglial activation is associated with M1 polarization and enhanced migration ability, indicating that this pathway could be a useful target to ameliorate inflammation in the central nervous system.


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