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.     

Investigations of the butylcholinesterase-containing cells of the adenohypophysis of the white-crowned sparrow,Zonotrichia leucophrys gambelii

Summary In the adenohypophysis of Zonotrichia leucophrys gambelii two types of cells with butylcholinesterase(BuChE) activity can be demonstrated histochemically. Type I occurs in the cephalic lobe of the pars distalis and in the pars tuberalis; it consists of oval and round cells. It is a distinctive cell type that is identical with the amphophilic cells described by Matsuo, Vitums, King and Farner (1969). Whereas castration or inhibition of thyroid gland activity causes only minor changes in these cells, blocking of adrenal cortex activity, or adrenalectomy, causes conspicuous hyperplasia and hypertrophy suggesting that these cells are involved in the production or release of ACTH. The second type, which occurs in both cephalic and caudal lobes, consists mostly of irregularly formed cells. Various observations indicate that it is a composite group, consisting, at least in part, of degenerating cells.These investigations were supported by grants from the National Institutes of Health (S ROI NB 06812) and the National Science Foundation (GB 5969) to Professor Farner.     

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; )     

A layover in Europe: Reconstructing the invasion route of asexual lineages of a New Zealand snail to North America

Non‐native invasive species are threatening ecosystems and biodiversity worldwide. High genetic variation is thought to be a critical factor for invasion success. Accordingly, the global invasion of a few clonal lineages of the gastropod Potamopyrgus antipodarum is thus both puzzling and has the potential to help illuminate why some invasions succeed while others fail. Here, we used SNP markers and a geographically broad sampling scheme (N = 1617) including native New Zealand populations and invasive North American and European populations to provide the first widescale population genetic assessment of the relationships between and among native and invasive P. antipodarum. We used a combination of traditional and Bayesian molecular analyses to demonstrate that New Zealand populations harbour very high diversity relative to the invasive populations and are the source of the two main European genetic lineages. One of these two European lineages was in turn the source of at least one of the two main North American genetic clusters of invasive P. antipodarum, located in Lake Ontario. The other widespread North American group had a more complex origin that included the other European lineage and two New Zealand clusters. Altogether, our analyses suggest that just a small handful of clonal lineages of P. antipodarum were responsible for invasion across continents. Our findings provide critical information for prevention of additional invasions and control of existing invasive populations and are of broader relevance towards understanding the establishment and evolution of asexual populations and the forces driving biological invasion.     

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.     

Repeated horizontal gene transfer of GALactose metabolism genes violates Dollo’s law of irreversible loss

Dollo’s law posits that evolutionary losses are irreversible, thereby narrowing the potential paths of evolutionary change. While phenotypic reversals to ancestral states have been observed, little is known about their underlying genetic causes. The genomes of budding yeasts have been shaped by extensive reductive evolution, such as reduced genome sizes and the losses of metabolic capabilities. However, the extent and mechanisms of trait reacquisition after gene loss in yeasts have not been thoroughly studied. Here, through phylogenomic analyses, we reconstructed the evolutionary history of the yeast galactose utilization pathway and observed widespread and repeated losses of the ability to utilize galactose, which occurred concurrently with the losses of GALactose (GAL) utilization genes. Unexpectedly, we detected multiple galactose-utilizing lineages that were deeply embedded within clades that underwent ancient losses of galactose utilization. We show that at least two, and possibly three, lineages reacquired the GAL pathway via yeast-to-yeast horizontal gene transfer. Our results show how trait reacquisition can occur tens of millions of years after an initial loss via horizontal gene transfer from distant relatives. These findings demonstrate that the losses of complex traits and even whole pathways are not always evolutionary dead-ends, highlighting how reversals to ancestral states can occur.     

Pushing short DNA fragments to the limit: Phylogenetic relationships of ‘hydrobioid’ gastropods (Caenogastropoda: Rissooidea)

Although phylogenetic studies are increasingly utilizing multi-locus datasets, a review of GenBank data for the Gastropoda indicates a strong bias towards a few short gene fragments (most commonly COI, LSU rRNA, and SSU rRNA). This is particularly the case for the Rissooidea, one of the largest and most taxonomically difficult gastropod superfamilies. Here we analyze fragments of these three genes from 90 species to determine whether they can well resolve higher relationships within this superfamily, whether structurally aligned sequence datasets increase phylogenetic signal, and whether the inclusion of highly variable regions introduces noise. We also used the resulting phylogenetic data in combination with morphological/anatomical evidence to re-evaluate the taxonomic status of ‘hydrobioid’ family-level groups.Our results indicate that all three of the alignment strategies that were used resulted in phylogenies having similar signal levels. However, there was a slight advantage to using structural alignment for inferring family-level relationships. Moreover, the set of ‘standard’ gastropod genes supported recognition of many previously recognized families and provides new insight into the systematics of several problematic groups. However, some family-group taxa were unresolved and the relationships among families were also poorly supported, suggesting a need for more extensive sampling and inclusion of additional genes.