Hyperexpression and Analysis of choB Encoding Cholesterol Oxidase of Brevibacterium sterolicum in Escherichia coli and Streptomyces lividans.

We examined the expression of choB, encoding cholesterol oxidase of Brevibacterium sterolicum ATCC 21387, in Escherichia coli JM105 and Streptomyces lividans TK23 using various deletion DNA fragments within the 5′-flanking region. The enzyme activity could be detected intracellularly in E. coli only when the 5′-flanking region was reduced to less than 256-bp and choB was transcribed by the lac promoter. A large amount of the enzyme were produced as inactive inclusion bodies when ChoB protein was fused with the NH₂-terminal portion of LacZ protein. In contrast, choB with more than 256-bp of the 5′-flanking region was efficiently expressed in S. lividans TK23, and about 85 times as much of the active enzyme (170 U/ml) was secreted into the culture filtrate as with B. sterolicum in flask culture. These results suggest that the promoter of choB exist within 256-bp of the 5′-flanking region and can be efficiently recognized by the RNA polymerase of S. lividans. The characteristics of the enzyme purified from the culture filtrate of the S. lividans transformant and that of B. sterolicum were identical although the NH₂-terminal amino acid sequence of the enzyme from the S. lividans transformant was 6 amino acids shorter than that from B. sterolicum.     

The Technological Multiplicity of the Acheulean of the Southern Iberian Peninsula

The Acheulean of the southern Iberian Peninsula is markedly similar to the north African Acheulean. However, the characteristics of the stone tool assemblages are heterogeneous and represent complex cultural phenomena. From MIS 15, the lithic assemblages in fluvial (Guadiana, Guadalquivir and Guadalete rivers), fluvio-lacustrine (Solana del Zamborino) and karstic (Cueva del Ángel, Bolomor, Cueva Negra del río Quípar, Cueva Horá and Santa Ana) contexts exhibit analogies and technical differences representative of a phenomenon of multiplicity. Contributing to this phenomenon is the perception of technological stasis or conservatism of the Acheulean technocomplex and the different technical responses articulated by hominins to achieve equivalent results. These equivalences generate the uniformity that allows us to recognise typologies of large cutting tools (LCTs) regardless of the lithic materials used or the organisational structures of the operational sequences. These diversified typologies include handaxes, picks, and cleavers, which maintain a consistent presence despite innovations such as the Levallois flaking method. In some cases, the presence of cleavers and spheroids affects the range of represented typologies. Beneath the uniformity of the handaxes, lie organisational differences in the operational sequences. The changes and differences in the use of flakes to shape handaxes, the representation of cleavers and diversification of shaped-tool typologies all suggest differential cultural behaviours linked in part to divergent contexts. These aspects indicate that this multiplicity is related to diffusion, adaptation and cultural changes produced at the margins of the conservatism of this technocomplex. Observed changes could indicate inter-group cultural replacements, most of which retained a similar techno-typological diversity to that seen in the north African Acheulean until MIS 5. Cyclical climate change during the Middle Pleistocene affected the Strait of Gibraltar, regulating its function and conditioning the circulation of hominins and affecting cultural interactions between southern Iberian groups.     

An unusual presentation of fine needle aspiration (FNA) cytology from the syncytial variant of nodular sclerosing Hodgkin's disease

Introduction
Open access breast clinics are now widely available and immediate reporting of FNAs of the breast has become an established part of the triple approach to the management of breast disease ¹ .
We report the unexpected findings of a case of Hodgkin's disease at such a clinic. The patient was a young woman who initially was thought by both her general practitioner and surgeon to have a fibroadenoma in the axillary tail region of her right breast. The FNA of this lump showed the features of Hodgkin's disease but with widespread necrosis, which was unusual and potentially misleading and which we wish to highlight. A lymph node biopsy confirmed the diagnosis and showed that the patient was suffering from the syncytial variant of nodular sclerosing Hodgkin's disease (NSHD).
This variant probably accounts for about 5% of cases of Hodgkin's disease ² . Necrosis is a common feature of NSHD; it can range from minute scattered foci to more extensive necrosis of nodules or even involve the entire lymph node.     

Taxonomic notes on Laurencia mariannensis (Rhodomelaceae, Rhodophyta)

The marine red alga Laurencia mariannensis Yamada (Rhodomelaceae, Ceramiales) is characterized by pale rose-red, softly fleshy, slender, terete axes (up to 600 μm in diameter), arising from a loosely entangled, stoloniferous basal system among species that have the following combination of features: the presence of longitudinally orientated secondary pit-connections between contiguous superficial cortical cells; the presence of projecting superficial cortical cells at the upper portions of branches; and the presence of lenticular thickenings in the walls of medullary cells, Furthermore, the presence of two or three corps en cerise per superficial cortical cell and one per trichoblast cell may characterize the species.     

Regulation of adenylate cyclase in cultured cardiocytes from neonatal rats by adenosine and other agonists

The presence of adenosine receptors coupled to adenylate cyclase in cultured cardiocytes from atria and ventricles from neonatal rats is demonstrated in these studies. N-Ethylcarboxamideadenosine (NECA), l-N⁶-phenylisopropyladenosine (PIA), and 2-chloroadenosine (2-cl-Ado) stimulated adenylate cyclase in a concentration-dependent manner in both cultured atrial and ventricular cells. The order of potency of stimulation was NECA > PIA > 2-cl-Ado. The stimulation of adenylate cyclase by NECA was enhanced by guanine nucleotides and was blocked by 3-isobutyl-1-methylxanthine in both these cells. Other agonists such as epinephrine, norepinephrine, dopamine, F^?, and forskolin were also able to stimulate adenylate cyclase, although the extent of stimulation by these agents was higher in ventricular than in atrial cells. The stimulation of adenylate cyclase by epinephrine and norepinephrine was inhibited by propranolol but not by phentolamine. On the other hand, phentolamine, propranolol, and haloperidol inhibited dopamine-stimulated adenylate cyclase activity to the same extent. Forskolin, at its maximal concentration, potentiated the stimulatory effect of epinephrine, norepinephrine, and dopamine on adenylate cyclase in both atrial and ventricular cardiocytes, but the interaction of NECA with epinephrine, norepinephrine, or dopamine was different in atrial and ventricular cells. The stimulation by an optimal concentration of NECA was additive with maximal stimulation by the catecholamines in atrial cells but not in ventricular cells. The data suggest the existence of adenosine “Ra” and catecholamine receptors in cultured atrial and ventricular cardiocytes. It can be postulated that adenosine in addition to its role as a potent vasodilator might regulate cardiac performance through its interaction with “Ra” receptors associated with adenylate cyclase. The difference in the mode of interaction of adenosine with catecholamines in atrial and ventricular cells suggests that the mechanism by which these agents activate adenylate cyclase may be different in these cells.     

In vitro study of the biological activity of RNAs after incubation of hog liver, heart and brain tissue at room temperature

The biological activity of RNA, isolated from tissue which was incubated for 1, 3, or 6 hours at room temperature (simulation of post-mortem conditions), was preserved. However, the different organs used differ from each other. When liver is used, qualitative differences in the in vitro translation products are observed, after one hour incubation at room temperature, whereas when heart and brain are used these differences are not observed. We have also shown that relatively small amounts of post-mortem tissue is sufficient for RNA extraction. When using frozen tissue it is absolutely necessary to add RNase inhibitors during thawing to reduce the loss of biological activity.     

Pituitary metabolism of 5alpha-androstane-3beta-17beta-diol: intense and rapid conversion into 5alpha-androstane-3beta,6alpha,17beta-triol and 5alpha-androstane-3beta,7alpha, 17beta-triol.

In the male rat pituitary, 5alpha-androstane-3beta, 17beta-diol (3beta-diol) is extensively metabolized into polar steroids. They were identified as 5alpha-androstane-3beta, 6alpha-17beta-triol (6alpha-triol) and 5alpha-androstane-3beta, 7alpha, 17beta-triol (7alpha-triol). 6-alpha-Triol represents 53% and 7alpha-Triol 28% of the total 3beta-diol metabolites. The remaining percentage is related to 6beta and 7beta isomers. The biological role of triols is still unknown.     

A comparative study on intrinsic fluorescence of BSA and lysozyme proteins in presence of different divalent ions from their solution and thin film conformations

Optical emission behaviours of lysozyme and bovine serum albumin, from bulk and thin film geometry, were studied in the presence of three different divalent ions (Mg²⁺, Ca²⁺ or Ba²⁺) using different spectroscopic [steady‐state fluorescence, UV–Vis and Fourier transform infra‐red (FTIR)] techniques. Additionally, protein thin films on silicon surfaces were prepared and morphological studies were carried out using atomic force microscopy. Dynamic quenching was mainly identified for both proteins in the presence of Mg²⁺, Ca²⁺ and Ba²⁺ ions. The molecular conformation of the proteins was modified in thin films compared with that in solution, consequently quenching efficiencies also varied. ATR‐FTIR studies confirmed the conformational changes of proteins in the presence of all divalent ions. All metal ions used were divalent in nature and belonged to the same group of the periodic table but, depending on their individual characteristics such as electron affinity, ionic radius, etc., the magnitude of the protein and hydrated ion interaction varied and accordingly the quenching efficiency was modified. Quenching was maximum for Ca²⁺ ions, followed by the other two ions. Our study clearly illustrates the geometry‐dependent physical and biological functions of proteins.     

First isolation and molecular characterization of Cryptococcus neoformans var. grubii in excreta of birds in the urban perimeter of the Municipality of Popayán,Colombia

Background

Cryptococcosis is a systemic opportunistic mycosis, caused by Cryptococcus neoformans and Cryptococcus gattii, which affects mainly the central nervous system of immunocompromised patients; no reports have been made on the isolation of the fungus from the environment of Popayán, Colombia.