A 3D supramolecular network of cobalt(II)(bis(4-pyridyl)ethylene) with terephthalate dianions

A three dimensional supramolecular network, {[Co(bpee)(H₂O)₄] · (tp) · 2(H₂O)}_n (1) [bpee = trans-1,2 bis(4-pyridyl)ethylene; tp = terephthalate dianion] has been synthesized and characterized by X-ray single crystal structure, magnetic measurement and thermal analysis. The structure determination reveals that the cobalt(II) ions, bridged by bpee and coordinated by four water molecules, give rise to covalently linked 1D polymeric chain. The parallel chains get involved in H-bonding with tp resulting in a 3D architecture. Upon heating 1, which is pink in color, transforms to [Co(bpee)(tp)] (1a, blue). The deaquated species (1a) reverts on keeping in humid atmosphere. Low temperature magnetic data indicate weak antiferromagnetic coupling.     

Two Cases of Vaginitis Caused by Itraconazole-Resistant Saccharomyces cerevisiae and a Review of Recently Published Studies

Genitourinary infections caused by non-Candida yeasts are uncommon, and especially due to Saccharomyces cerevisiae. We describe the cases of two adult females with vulvovaginal infections caused by itraconazole-resistant S. cerevisiae who made a full recovery after oral fluconazole therapy. We also provide a concise review of recently published studies on this topic.     

Eco‐morphological attributes and feeding habits in coexisting characins

The head morphology and feeding habits of pairs of characin species (family Characidae) that coexist in four different coastal rainforest streams were analysed. Coexisting species differed in size, but were very similar in eco‐morphological attributes. Gut analyses revealed differences in feeding preferences for each coexisting species, indicating resource partitioning. A pattern of organization in species pairs that was repeated in the four studied streams was noticed. The pattern consisted of one slightly larger species with a feeding preference for items of allochthonous origin and another smaller species with a preference for autochthonous items. The hypothesis that small morphological differences enable the current coexistence of those species pairs was proposed. Furthermore, the results show ecological equivalence among different species in the studied streams.     

Homology model of the human tRNA splicing ligase RtcB

RtcB is an essential human tRNA ligase required for ligating the 2',3'‐cyclic phosphate and 5'‐hydroxyl termini of cleaved tRNA halves during tRNA splicing and XBP1 fragments during endoplasmic reticulum stress. Activation of XBP1 has been implicated in various human tumors including breast cancer. Here we present, for the first time, a homology model of human RtcB (hRtcB) in complex with manganese and covalently bound GMP built from the Pyrococcus horikoshii RtcB (bRtcB) crystal structure, PDB ID 4DWQA. The structure is analyzed in terms of stereochemical quality, folding reliability, secondary structure similarity with bRtcB, druggability of the active site binding pocket and its metal‐binding microenvironment. In comparison with bRtcB, loss of a manganese‐coordinating water and movement of Asn226 (Asn202 in 4DWQA) to form metal‐ligand coordination, demonstrates the uniqueness of the hRtcB model. Rotation of GMP leads to the formation of an additional metal‐ligand coordination (Mn‐O). Umbrella sampling simulations of Mn binding in wild type and the catalytically inactive C122A mutant reveal a clear reduction of Mn binding ability in the mutant, thus explaining the loss of activity therein. Our results furthermore clearly show that the GTP binding site of the enzyme is a well‐defined pocket that can be utilized as target site for in silico drug discovery.     

Acetylcholinesterase in the central nervous system and digestive gland of Achatina fulica Bowdich.

Cholinesterase (ChE) activity was measured in the central nervous system (CNS) and in the digestive gland of the pestiferous land snail Achatinafulica Bowdich, by the method of Huegra et al. (1952). Acetylcholinesterase (AChE), and benzoylcholinesterase (BeChE) activity was higher in the former than in the latter. The complete inhibition of the enzyme activity with 10(-2) M eserine indicates that the ChE examined is AChE. The Km values of the AChE from the digestive gland and the CNS were 3.1 x 10(-5) and 9.0 x 10(-5) (M), respectively. The enzyme is the most active at pH 8.2 and 37 degrees C up to 60 min.     

Effects of newly reported arachidonic acid metabolites on microsomal Ca++ binding, uptake and release

The 5,6-; 8,9-; 11,12- and 14,15-epoxyeicosatrienoic acids and their respective hydration products, the vic-diols, recently reported as metabolites of arachidonic acid in rat liver microsomes, were examined for effect on release of 45Ca from canine aortic smooth muscle microsomes. At 10(-6) M, the diols had no effect, but the 5,6-; 11,12- and 14,15-epoxyacids increased the loss of 45Ca. Further studies with the 14,15-epoxyacid demonstrated a dose-dependent decrease of Ca++ uptake (ATP present) in canine aortic microsomes in 0.03 mM Ca++, whereas Ca++ binding (ATP absent) was not affected. Ca++ uptake, binding and release in rat liver microsomes was similarly affected by the 14,15-epoxyacid, the major epoxyeicosatrienoic acid derivative produced by rat liver microsomal incubations. It is suggested that alterations in Ca++ metabolism might be a possible mechanism of action for these derivatives of arachidonic acid.     

Genetic analysis of a Minute mutation in the distal region of the second chromosome ofDrosophila melanogaster

Genetic organization of a proximal region of the second chromosome inDrosophila melanogaster has been analysed by saturation mutagenesis. Seven alleles were uncovered in this region in addition to the one previously known. Besides this, quite a few mutations were isolated that non-complemented more than one group of lethals and looked very much like deletions of varying extent. Except one, all the lethals complemented M(2)z.     

Effects of newly arachidonic acid metabolites on microsomal Ca binding, uptake and release

The 5,6- 8,9-; 11,12- and 14,15-epoxyeicosatrienoic acids and their respective hydration products, the vic-doisl, recently reported as metabolites of arachidonic acid in rat liver microsomes, were examined for effect on release of 45Ca from canine aortic smooth muscle miscrosomes. At 10⁻⁶ M, the diols had no effect, but the 5,6-; 11,12- and 14,15-epoxyacids increased the loss of ⁴⁵Ca. Further studies with the 14,15-epoxyacid demonstrated a dose-dependent decrease of Ca⁺⁺ uptake (ATP present) in canine aortic microsomes in 0.03 mM Ca⁺⁺, whereass Ca⁺⁺ binding (ATP absent) was not affected. Ca⁺⁺ uptake, binding and release in rat liver microsomes was similarly affected by the 14,15-epoxyacid, the major epoxyeicosatrienoic acid derivative produced by rat liver miscrosomal incubations. It is suggested that a alterations in Ca⁺⁺ metabolism might be a possible mechanism of actions for these derivatives of arachidonic acid.     

Comparative cytologic features of adenocarcinoma in situ of the uterine cervix

The cytologic findings in 30 cases of adenocarcinoma in situ (AIS) and related lesions of the cervix were compared with those in 13 cases of cervical invasive adenocarcinoma and 8 cases of cervical nonneoplastic conditions that mimicked AIS cytologically. Although there was considerable overlap, the presence of large cells with irregular nuclei and uneven chromatin distribution in smears containing no normal endocervical cells helped to distinguish invasive adenocarcinoma from AIS. The presence of "feathering," rosettes, mitotic figures and very crowded nuclei with scant cytoplasm and without cilia helped distinguish AIS from benign conditions.