Sporothrix schenckii isolated fromdomestic cats with and without sporotrichosis in Rio de Janeiro,Brazil

A total of 148 cats with a clinical and mycologic diagnosis of sporotrichosis and 84 apparently healthy cats with domiciliary contact with the affected animals were studied. Sporothrix schenckii was isolated from 148 (n = 148; 100%) clinical samples of cutaneous lesion (biopsy, swab or aspiration of purulent secretion), 47(n = 71; 66.2%) nasal cavities, 33 (n = 79; 41.8%) oral cavities, and 15 (n = 38; 39.5%) nails of cats with sporotrichosis. Histopathological examination revealed yeast-like structures in 50 (n = 70; 71.4%) of the biopsies studied. S. schenckii was isolated from the blood culture of one cat (n = 5, 20%) with the disseminated cutaneous form of the disease. On another occasion, the fungus was isolated from the testis of one (n = 7; 14.3%) of the animals submitted to sterilization. In the group of cats with domiciliary contacts, 3(n = 84; 3.57%) oral swabs showed positive cultures. Isolation of S. schenckii from different clinical specimens during both the clinical and preclinical phase reinforces the zoonotic potential of feline sporotrichosis. This revised version was published online in June 2006 with corrections to the Cover Date.     

Secondary structure of antisauvagine analogues is important for CRF receptor antagonism: development of antagonists with increased potency and receptor selectivity

Antisauvagine-30 (aSVG) is the only high-affinity antagonist for the corticotropin-releasing factor (CRF) type 2 (CRF(2)) receptor. A structure-activity relationship study was performed to pinpoint residues conferring aSVG's selectivity. The aSVG-analogues being N-terminally extended by one or two residues or containing the Ala(22)Arg(23)Ala(24) (ARA-motif) of CRF, were synthesized. Additionally, a lactam bridge between positions 29 and 32 was introduced. The modified peptides were analyzed for alpha-helicity properties, binding affinities and antagonistic potencies at the rat CRF(1) and mouse CRF(2B) receptors. While N-terminal prolongation and replacement of D-Phe(11) by Tyr(11) increased the affinity for the CRF(2) receptor, the introduction of the ARA motif resulted in a loss of CRF(2) receptor selectivity. These data show that aSVG(10-40) analogues are more potent CRF(2) receptor antagonists than aSVG(11-40) peptides, while introduction of the ARA-motif or a cyclic constraint between residues 29 and 32 favors binding to the CRF(1) receptor.     

Anaerobic degradation of protocatechuate (3,4-dihydroxybenzoate) by Thauera aromatica strain AR-1

The denitrifying bacterium Thauera aromatica strain AR-1 grows anaerobically with protocatechuate (3,4-dihydroxybenzoate (DHB)) as sole energy and carbon source. This bacterium harbors two distinct pathways for degradation of aromatic compounds, the benzoyl-coenzyme A (CoA) pathway for benzoate degradation and the hydroxyhydroquinone (HHQ) pathway for degradation of 3,5-DHB. In order to elucidate whether protocatechuate is degraded via the benzoyl-CoA or the HHQ pathway, induction experiments were carried out. Dense suspensions of cells grown on protocatechuate or benzoate readily degraded benzoate and protocatechuate but not 3,5-DHB. Dense suspensions of 3,5-DHB-grown cells degraded 3,4- and 3,5-DHB at similar rates, but benzoate was not degraded. 3,5-DHB hydroxylating activity was found only in cells grown with this substrate. HHQ dehydrogenase activity was found in extracts of cells grown with 3,5-DHB and at a low rate also in protocatechuate-grown cells, but not in extracts of cells grown with benzoate. Activities of protocatechuyl-CoA synthetase and protocatechuyl-CoA reductase leading to 3-hydroxybenzoyl-CoA were found in extracts of cells grown with protocatechuate. There was no repression of the HHQ pathway by the presence of protocatechuate, unlike by degradation of benzoate. We conclude that protocatechuate is not degraded via the HHQ pathway because there was no evidence of a hydroxylation reaction involved in this process. Instead, our results strongly suggest that protocatechuate is degraded via a pathway which connects to the benzoyl-CoA route of degradation.     

Affinity labeling of cysteine-mutants evidences contact residues in modeled receptor binding sites

To investigate the topology of binding sites in two ionotropic receptors, we have initiated a strategy combining affinity labeling with cysteine-scanning mutagenesis. For the GABAA receptor we have used reactive derivatives of non-competitive blockers (NCBs) to explore interacting positions in its channel. The polypeptide positions of the M2 segment of the alpha1 subunit which we mutated into cysteine were selected for their established accessibility, as determined by the substituted-cysteine accessibility method (SCAM). Using the Xenopus oocyte expression system, we show that receptors containing mutations V257C and S272C are inactivated by several reactive NCBs. These position-selective inactivations lead to an analysis of NCB binding in the channel. For the NMDA receptor glycine-binding site, the prototype antagonist L-701,324 was derivatized at different positions with different reactive groups. The receptor positions to mutate into cysteine were selected after a 3-D homology model. The observed receptor inactivations are mutant- and probe-selective, leading to an unambiguous chemical docking of the antagonist pharmacophore and supporting the model. The site-specificity of the inactivating reactions is assessed by protection experiments and by mutant to wild-type (WT) comparisons. The scope and limitations of the method are briefly discussed.     

Flavones from Andrographis viscosula

Two new 2'-oxygenated flavones, 5,7,2'-trimethoxyflavone (1). and 5,7,2',4',6'-pentamethoxyflavone (2). were isolated from the whole plant of Andrographis viscosula along with three known flavones, echioidinin (3). 5,2',6'-trihydroxy-7-methoxyflavone (4). and echioidin (5). The structures of these compounds were elucidated on the basis of 1D and 2D NMR spectral studies.     

Follistatin regulates bone morphogenetic protein-7 (BMP-7) activity to stimulate embryonic muscle growth

Bone morphogenetic proteins (BMPs) can either promote growth of embryonic muscle by expanding the Pax-3-expressing muscle precursor population or restrict its development by inducing apoptosis. Follistatin, a proposed BMP antagonist, is expressed in embryonic muscle. Deficiency in Follistatin results in muscle defects and postnatal asphyxia. Here, we report that during chick limb development Follistatin enhances BMP-7 action to induce muscle growth but prevents the ability of BMP-7 to induce apoptosis and muscle loss. Follistatin, unlike another BMP-binding protein, Noggin, promotes Pax-3 expression and transiently delays muscle differentiation and thus exerts proliferative signalling during muscle development. We provide data which show that Follistatin binds BMP-7 and BMP-2 at low affinities and that the binding is reversible. These data suggest that Follistatin acts to present BMPs to myogenic cells at a concentration that permits stimulation of embryonic muscle growth.     

Clinical Efficacy and Compatibility of Allogeneic Avital Tissue Transplants Sterilized with a Peracetic Acid/Ethanol Mixture

In the course of the past 20 years a quantity of approximately 60,000 allogeneic avital tissue grafts sterilized with the peracetic acid–ethanol method (PES) were transplanted successfully. Based on a retrospective report of clinical experience of the years 1997–2001 on the overall scope of tissue grafts manufactured by the Tissue Banks of the University Hospital Charité and the German Institute for Cell and Tissue Replacement, the clinical efficacy and side effects of 18.3% (3.087/16.823) of all transplants were studied. Cancellous (1.601/3.087) and cortical (291/3.087) bone transplants as well as amnion (1.027/3.087) constituted the greatest part. In 91% of the examined patients (2.369/2.592) tissue integration ratios ranging from good up to very well could be observed. The transplant function of defect replacement or of a spacer respectively could be obtained for all types of tissue. The clinical effect caused by the transplant resulted in more than 99% of the transplants in primary integration or in the desired aim of the therapy (defect replacement, stabilization in case of palliative operations, etc.). In less than 1% (9/2.592) of cases a secondary healing occurred for cancellous bone transplantations or, revisional operations became necessary. In all cases severe side effects, in particular transmission of infectious diseases or transplant rejections, were not observed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Further research on the differentiation in vitro of chick-embryo skin in the presence of histones

In the present study the authors have carried out further researches on the differentiation of six day limb skin from chick embryo cultured "in vitro" in a complete medium supplemented with histones. When histones were added to the medium in the first two days "in vitro", epidermal keratinization was not observed. However the addition of histones after four days "in vitro" did not interfere with epidermal differentiation.     

Cryptococcus neoformans varieties as agents of cryptococcosis in Brazil

The study of the clinical isolates of Cryptococcus neoformans from 83 Brazilian patients with disseminated cryptococcosis showed that 75 were C. neoformans var. neoformans and 8 were var. gattii. Twenty-seven isolates were serotyped; all 19 var. neoformans were serotype A and all 8 var. gattii were serotype B. The correlation of the varieties of C. neoformans with the presence or not of hosts predisposing conditions to the mycosis showed that: (1) cryptococcosis caused by gattii variety occurred in 7 (58.3%) of the 12 nonimmunosuppressed patients, and (2) cryptococcosis caused by neoformans variety occurred in 65 (98.5%) of the 66 AIDS patients and in all 5 patients with other immunosuppressive conditions. The comparison of the distribution of the gattii and neoformans varieties between the nonimmunosup-pressed and immunosuppressed patients showed a significant statistical difference (p < 0.01).