Peroxidase cytochemistry and ultrastructure of resident macrophages in fetal rat liver: A developmental study

The peroxidase cytochemistry and the ultrastructural characteristics of resident macrophages in fetal rat liver have been investigated. Livers of 10-, 11-, 14-, 17-, and 20-day-old fetuses were fixed by immersion or perfusion, incubated for peroxidase, and processed for transmission electron microscopy. Some 17- and 20-day-old fetuses were injected prior to sacrifice with carbon or 0.8-μm latex particles through the umbilical vein. Some livers were additionally processed for scanning electron microscopy (SEM). The endogenous peroxidase was present in the nuclear envelope (NE) and endoplasmic reticulum (ER) of fetal macrophages with a negative reaction in the Golgi apparatus, a distribution pattern identical to that in Kupffer cells of adult rat liver. Such peroxidase-positive cells avidly took up the injected latex and carbon particles and were the only cell type in fetal liver involved in erythrophagocytosis. Furthermore, they were associated with erythropoietic elements, forming close contacts with such cells, especially normoblasts. The peroxidase pattern in leukopoietic cells differed at all stages of maturation from that in macrophages. By SEM the macrophages exhibited ruffles and lamellopodia on their surfaces and protruded often into the lumen of fetal sinusoids. Macrophages in fetal liver underwent mitotic divisions. The macrophages were first seen on gestation day 11, whereas the first mature monocytes were found on gestation day 17. These observations suggest that resident macrophages in fetal rat liver form a self-replicating cell line independent of the monocytopoietic series, although they may both arise from a common precursor cell.     

ORGAN CULTURE OF THE RAT ADRENAL MEDULLA: A MODEL SYSTEM FOR THE STUDY OF TRANS-SYNAPTIC ENZYME INDUCTION

—It was the aim of the present study to develop organ culture conditions for the rat adrenal medulla which are representative for the in vivo situation. This is a prerequisite for studying the complex processes involved in trans-synaptic enzyme induction. The processes of trans-synaptic enzyme induction initiated in vivo by injecting 5 mg/kg of reserpine 2 h prior to the removal of the adrenal medulla, continued in this culture system and final levels of tyrosine hydroxylase were comparable to those seen in vivo. That these culture conditions are representative for the in vivo induction is also supported by the fact that transection of the splanchnic fibres supplying the adrenal medulla or administration of actinomycin D prior to reserpine abolished the rise in tyrosine hydroxylase activity not only in vivo, but also in culture. The findings that high concentrations (0·29 mm ) of corticosterone in the culture medium inhibited the increase in tyrosine hydroxylase activity caused by reserpine support the hypothesis that glucocorticoids act as modulatory agents in trans-synaptic enzyme induction. This inhibition was exhibited only when corticosterone was added at the initiation of the culture period. If added 2 or 4 h after the beginning of the culture period there was little or no effect on the subsequent increase of tyrosine hydroxylase.     

Efficacy of different types of aerobic exercise in fibromyalgia syndrome: a systematic review and meta-analysis of randomised controlled trials

Introduction  

The efficacy and the optimal type and volume of aerobic exercise (AE) in fibromyalgia syndrome (FMS) are not established. We therefore assessed the efficacy of different types and volumes of AE in FMS.     

Proteolytic enzymes in Chlamydomonas I. A survey on the aminopeptidase pattern in asynchronous vegetative cells of Chlamydomonas reinhardii

The supernatant of a crude extract from vegetative cells ofChlamydomonas reinhardii contains three different types of aminopeptidases.They are similar in their substrate specificities to the relativealanine specific aminopeptidases, the relative leucine specificaminopeptidases and the specific proline iminopeptidases describedin many other systems. Relative alanine specific aminopeptidasewhich also cleaves N-terminal Lys and Leu residues has a molecularweight of 92,000 daltons and is inhibited by zinc and manganeseions.Relative leucine specific aminopeptidase shows high activitywith N-terminal Phe besides Leu, and is capable of cleavingTyr, Pro, and to a minor degree Ala. It has a molecular weightof 76,000 daltons. No effects on its activity were detectedin the presence of divalent cations or chelating agents. Theiminopeptidase specifically splits N-terminal Pro and has amolecular weight of about 255,000 daltons. All the enzymes showoptimal activity at pH 8.0–8.5. The two aminopeptidases can be separated from the iminopeptidaseby ammonium sulfate solubilization and from each other by subsequentfractionation on DEAE-cellulose. Relative leucine specific activityappeared as a single enzyme in all the fractionation techniquesused, but it gave two distinct bands when crude extracts wererun on native polyacrylamide gels. Therefore, this enzyme mayexist in multiple molecularforms. (Received October 17, 1978; )     

Focus: Zoonotic Disease: New Series of Imidazoles Showed Promising Growth Inhibitory and Curative Potential Against Trypanosoma Infection

The Trypanosoma spp. cause animal and human trypanosomiasis characterized with appreciable health and economic burden mostly in developing nations. There is currently no effective therapy for this parasitic disease, due to poor drug efficacy, drug resistance, and unwanted toxicity, etc. Therefore, new anti-Trypanosoma agents are urgently needed. This study explored new series of imidazoles for anti-Trypanosoma properties in vitro and in vivo. The imidazoles showed moderate to strong and specific action against growth of T. congolense. For example, the efficacy of the imidazole compounds to restrict Trypanosoma growth in vitro was ≥ 12-fold specific towards T. congolense relative to the mammalian cells. Additionally, the in vivo study revealed that the imidazoles exhibited promising anti-Trypanosoma efficacy corroborating the in vitro anti-parasite capacity. In particular, three imidazole compounds (C1, C6, and C8) not only cleared the systemic parasite burden but cured infected rats after no death was recorded. On the other hand, the remaining five imidazole compounds (C2, C3, C4, C5, and C7) drastically reduced the systemic parasite load while extending survival time of the infected rats by 14 days as compared with control. Untreated control died 3 days post-infection, while the rats treated with diminazene aceturate were cured comparable to the results obtained for C1, C6, and C8. In conclusion, this is the first study demonstrating the potential of these new series of imidazoles to clear the systemic parasite burden in infected rats. Furthermore, a high selectivity index of imidazoles towards T. congolense in vitro and the oral LD₅₀ in rats support anti-parasite specific action. Together, findings support the anti-parasitic prospects of the new series of imidazole derivatives.     

A simple and inexpensive method for investigating microbiological,enzymatic, or inorganic catalysis using standard histology and microbiology laboratory equipment: assembly,mass transfer properties,hydrodynamic conditions and evaluation

We introduce a generic, simple, and inexpensive method for performing microbiological, enzymatic, or inorganic catalysis with solids using standard histology and microbiology laboratory equipment. Histology cassettes were used to standardize hydrodynamic conditions and to protect the catalysts and their solid supports. Histology cassettes have the following advantages: they are readily available, inexpensive, solvent and acid resistant, automatable, and the slots in the cassette walls allow liquid to circulate freely. Standard Erlenmeyer flasks were used as reaction vessels. We developed a new camera to observe the movement and position of the histology cassettes as well as the liquid in the Erlenmeyer flasks. The camera produces a stable image of the rotating liquid in the Erlenmeyer flask. This visualization method revealed that in a 250?ml Erlenmeyer flask, stable operating conditions are achieved at a shaking frequency of 300?rpm and a fill volume of 30?ml. In vessels with vertical walls, such as beakers or laboratory bottles, the movement of the histology cassette is not reproducible. Mass transfer characterization using a biological model system and the chemical sulfite-oxidation method revealed that the histology cassette does not influence gas-liquid mass transfer.     

Unilateral Dampening of Bmp Activity by Nodal Generates Cardiac Left-Right Asymmetry

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Highlights? Cardiac laterality involves Nodal modulating an antimotogenic Bmp activity ? The Nodal target Hyaluronan synthase 2 unilaterally dampens Bmp signaling activity ? Nonmuscle myosin II is positively regulated by Bmp within cardiac tissue ? High levels of nonmuscle myosin II activity reduce cardiac cell motility