Comparing the delivery to the hair bulb of two fluorescent molecules of distinct hydrophilicities by different nanoparticles and a serum formulation

The follicular route is an important drug penetration pathway in any topical application, either concerning dermatological and cosmetic skin treatments or any transdermal administration regimen. Efficient transport into follicles will depend on drug inherent properties but also on the chosen vehicle. The main study goal was to compare several systems for the delivery to the hair bulb of two fluorescent molecules of different water affinities: the hydrophobic Nile Red and the quite similar but hydrophilic Nile Blue. Three common nanoparticle types were compared in terms of encapsulation efficiency and stability: liposomes, ethosomes and polymeric nanoparticles. A liquid serum-like formulation was also developed, adjusting the final ethanol amount to the type of dye to be solubilized. Then, this formulation and the nanoparticle systems that successfully passed characterization and stability stages were further studied on their ability to reach the bulb. The serum formulation was able to deliver, both drug models, to deeper follicular regions than nanoparticles. Attending to the envisioned zone target of the follicle, the simplest approach proved to be the best choice from all the systems tested in this work. Nonetheless, nanocarriers and the inherent complexity of their manufacturing processes may be justified under very specific requirements.

Increased Encapsulation Efficiency of Methotrexate in Liposomes for Rheumatoid Arthritis Therapy

Methotrexate (MTX) is a common drug used to treat rheumatoid arthritis. Due to the excessive side effects, encapsulation of MTX in liposomes is considered an effective delivery system, reducing drug toxicity, while maintaining its efficacy. The ethanol injection method is an interesting technique for liposome production, due to its simplicity, fast implementation, and reproducibility. However, this method occasionally requires the extrusion process, to obtain suitable size distribution, and achieve a low level of MTX encapsulation. Here, we develop a novel pre-concentration method, based on the principles of the ethanol injection, using an initial aqueous volume of 20% and 1:1 ratio of organic:aqueous phase (v/v). The liposomes obtained present small values of size and polydispersity index, without the extrusion process, and a higher MTX encapsulation (efficiency higher than 30%), suitable characteristics for in vivo application. The great potential of MTX to interact at the surface of the lipid bilayer was shown by nuclear magnetic resonance (NMR) studies, revealing mutual interactions between the drug and the main phospholipid via hydrogen bonding. In vivo experiments reveal that liposomes encapsulating MTX significantly increase the biological benefit in arthritic mice. This approach shows a significant advance in MTX therapeutic applications.

Protective Effect of Saccharides on Freeze-Dried Liposomes Encapsulating Drugs

The production of freeze-dried liposomes encapsulating drugs is considered a key challenge since the drugs are prone to leakage. The aim of this work was to study the effect of different saccharides on preserving the stability and drug retention capacity of a previously developed liposomal formulation, when subjected to a freeze-drying process. The protective role of trehalose, lactose, glucose, mannitol and sucrose, known for their cryo/lyoprotective effect, was tested by addition of different concentrations to liposomes. Sucrose, in a concentration dependent manner (8:1 sugar:lipids mass ratio) proved to be a suitable cryo/lyoprotectant of these liposomes. Effectively, this saccharide prevents the fusion or/and aggregation of the liposomal formulation, protecting the integrity of the freeze-dried empty liposomes. The liposomal formulation containing sucrose was studied in terms of morphology, concentration, and anticancer drugs retention ability. The study involved two drugs encapsulated in the aqueous core, methotrexate (MTX) and doxorubicin (DOX), and one drug located in the lipid bilayer, tamoxifen (TAM). After the freeze-drying process, liposomes with sucrose encapsulating drugs revealed high physical stability, maintaining their narrow and monodisperse character, however high leakage of the drugs encapsulated in the aqueous core was observed. Otherwise, no significant drug leakage was detected on liposomes containing the TAM, which maintained its biological activity after the freeze-drying process. These findings reveal that sucrose is a good candidate for the cryo/lyoprotection of liposomes with drugs located in the lipid bilayer.

Vertical distribution and aggregation patterns of krill (Crustacea: Euphausiacea) in the Bay of Biscay: interannual and seasonal variability

Studies of krill (Crustacea: Euphausiacea) in oceanic waters of the Bay of Biscay are scarce and restricted to the epipelagic zone, overlooking vertical dynamics such as diurnal vertical migration (DVM). There is a growing interest in acoustically evaluating the biomass of krill in this area, but this requires a good knowledge of its vertical dynamics and aggregation patterns. In this work we employed acoustic data and net samples from two consecutive annual surveys covering a wide off-shelf area of the Bay of Biscay (JUVENA surveys of 2013 and 2014) and four seasonal surveys covering slope and oceanic waters in the Cantabrian Sea (SCAPA surveys of 2015). Vertical dynamics of krill were analyzed in the frame of the environmental seascape. High interannual and seasonal variations in the vertical distribution and aggregation patterns (small swarms, dense aggregations, or loose layers) of krill were observed. The vertical distribution covaried with dissolved oxygen and salinity. According to our findings, the best season to acoustically evaluate krill in the Bay of Biscay is spring, with the bulk of the biomass located above 600 m depth. Moreover, extending the acoustic recording beyond the epipelagic zone is mandatory for any season.

Refractory Anemia in a Kidney Transplant Recipient

Anemia is a common finding after kidney transplantation (KT). Herein, we present a 34-year-old man who received a deceased-donor KT in 2017. Induction immunosuppression therapy consisted of thymoglobulin, tacrolimus (TAC) and methylprednisolone; the maintenance therapy included mycophenolate (MMF) 500 + 500 mg, TAC 4 + 4 mg and prednisolone (PD) 5 mg. One year after KT, he progressively developed dyspnea and fatigue. Laboratory exams revealed hypochromic microcytic anemia unresponsive to increasing doses of darbepoetin. Upper endoscopy and colonoscopy were normal. Bone marrow examination revealed erythroid hyperplasia with numerous proerythroblasts. Serology and viral load for human parvovirus B19 were both positive. Immunosuppression was reduced; he was treated with immunoglobulin. After one week, anemia improved. After 2 months the patient remained asymptomatic with stable hemoglobin. Although rare, PVB19 infection is a clinically significant infection that often presents as aplastic anemia in the post-transplantation period.

Analyzing similarities in genome sequences

This article investigates aspects of similarity between complete sequences of mitochondrial DNA by determining the distribution of the relative frequencies of words with different lengths and the characteristics of their relevance throughout the sequences. The degree of similarity is obtained by comparing the distances between words contained within these sequences. Our results indicate that the best groupings among different species depend on the lengths of words and their respective relative frequencies. We also observed that the longer the word the more consistent the grouping between the sequences becomes. The application of our results, together with the perspective of analyzing DNA sequences belonging to a single biological species, may be important for the construction of phylogenetic trees, which are appropriate structures for understanding the evolutionary history of the species.

Absence of Albumin Improves in Vitro Cellular Uptake and Disruption of Poloxamer 407-Based Nanoparticles inside Cancer Cells

Novel nanoparticles based on Poloxamer 407 and vegetable oil were produced by high pressure homogenization. Functionalization of those nanoparticles was made by incorporation of folic acid (FA)-Poloxamer 407 conjugate. These nanoparticles showed suitable characteristics for intravenous therapeutic applications similarly to PEGylated albumin-based nanoparticles, previously described by our research group. Here, we found that the absence of albumin at the interface of Poloxamer 407-based nanoparticles improves the overall process of in vitro cellular uptake and nanoparticle disruption inside cancer cells (folate receptor, FR, positive cells). The results presented here suggest that interfacial composition of those nanoparticles is of paramount importance for drug trafficking inside cancer cells.

OBP fused with cell-penetrating peptides promotes liposomal transduction

Cell-penetrating peptides (CPPs) have been applied as novel transport systems with the ability to facilitate the delivery of peptides, proteins, and oligonucleotides into cells. Herein, we designed different fusion proteins composed by pig odorant binding protein (OBP-I) and three CPPs, namely Tat, pVEC and Pep-1. A new methodology using liposomes as reservoirs and OBP:CPPs as carriers was developed as an advanced system to capture odorant molecules. 1-aminoanthracene (1-AMA) was used as a model molecule to evaluate the transduction ability of OBP:CPPs into the reservoirs. The transduction efficiency was dependent on the initial capacity of OBP:CPPs to bind 1-AMA and on the penetration of liposomes promoted by the CPPs. An encapsulation efficiency of 42% was obtained with OBP:Tat fusion protein. The presence of Tat peptide increased the 1-AMA transduction of 1.3 and 2.5 fold compared with Pep-1 and pVEC, respectively. This work expands the application of OBPs and CPPs on the design of promising capture and delivery systems for textile and cosmetic applications.

Fab antibody fragment-functionalized liposomes for specific targeting of antigen-positive cells

Liposomes functionalized with monoclonal antibodies or their antigen-binding fragments have attracted much attention as specific drug delivery devices for treatment of various diseases including cancer. The conjugation of antibodies to liposomes is usually achieved by covalent coupling using cross-linkers in a reaction that might adversely affect the characteristics of the final product. Here we present an alternative strategy for liposome functionalization: we created a recombinant Fab antibody fragment genetically fused on its C-terminus to the hydrophobic peptide derived from pulmonary surfactant protein D, which became inserted into the liposomal bilayer during liposomal preparation and anchored the Fab onto the liposome surface. The Fab-conjugated liposomes specifically recognized antigen-positive cells and efficiently delivered their cargo, the Alexa Fluor 647 dye, into target cells in vitro and in vivo. In conclusion, our approach offers the potential for straightforward development of nanomedicines functionalized with an antibody of choice without the need of harmful cross-linkers.

Neutral PEGylated liposomal formulation for efficient folate-mediated delivery of MCL1 siRNA to activated macrophages

Cationic liposomes are efficient vectors for systemic delivery of therapeutic small interfering RNA (siRNA), taking advantage of RNA interference (RNAi), a naturally occurring gene-silencing mechanism in mammalian cells. However, toxicity at high concentrations, short circulating half-lives and lack of specificity restrict their successful application in a wider scale. The purpose of this study was to evaluate the efficiency of neutral liposomes containing polyethylene glycol (PEG) to encapsulate siRNA in their aqueous core. This formulation will reduce drastically the toxicity associated to cationic liposomes by bringing surface charge to almost zero, increasing stealth degree and therefore circulation time. In this study, we evaluate the efficiency of folate-targeted liposomes for specific delivery of siRNA to activated macrophages, key effector cells in rheumatoid arthritis (RA) pathology which specifically express folate receptor β (FRβ). Myeloid cell leukaemia-1 (Mcl-1) is a protein essential for synovial macrophage survival, since Mcl-1 suppression results in the induction of apoptosis. The effect of MCL1 siRNA incorporated in liposomal formulation was assessed in primary human macrophages and successful inhibition of Mcl-1 expression was achieved. Here we show that the neutral liposomal derived from DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine) formulation developed is efficient to encapsulate MCL1 siRNA and silencing gene expression in activated human macrophages.

Comportamento alimentar de vacas Nelore e de seus bezerros puros ou mestiços

RESUMO O objetivo desta pesquisa foi avaliar a influência do grupo genético do bezerro no comportamento alimentar diurno de mães e suas crias. Foram utilizadas 24 vacas Nelores paridas e seus bezerros, oito Nelores (puros), oito 1/2 Simental 1/2 Nelore e oito 1/2 Red Angus 1/2 Nelore. Avaliaram-se as medidas de frequência e duração das mamadas, tempo de pastejo e ruminação dos bezerros e das vacas. Os bezerros puros mamaram mais frequentemente que os mestiços (3,51 vs. 3,17 vezes/dia), porém com menor duração de mamada (7,37 vs. 7,80 minutos). A frequência de mamadas, a duração de cada mamada e o tempo total de mamadas diminuíram com o aumento da idade do bezerro. Nos bezerros, pastejo e ruminação aumentaram com a idade; entretanto, nas vacas, aumentou o tempo de pastejo e diminuiu o de ruminação com o passar dos dias. Os bezerros mestiços pastaram, em média, 18 minutos a mais que os puros, e os machos 16 minutos a mais que as fêmeas. Os bezerros machos ruminaram, aos 40 dias de idade, 25 minutos a mais que as fêmeas, mas essa diferença diminuiu com a idade e desapareceu por volta dos 220 dias. O comportamento da mãe e de sua cria é influenciado pelo grupo genético desta última.

Design of liposomal formulations for cell targeting

Liposomes have gained extensive attention as carriers for a wide range of drugs due to being both nontoxic and biodegradable as they are composed of substances naturally occurring in biological membranes. Active targeting for cells has explored specific modification of the liposome surface by functionalizing it with specific targeting ligands in order to increase accumulation and intracellular uptake into target cells. None of the Food and Drug Administration-licensed liposomes or lipid nanoparticles are coated with ligands or target moieties to delivery for homing drugs to target tissues, cells or subcellular organelles. Targeted therapies (with or without controlled drug release) are an emerging and relevant research area. Despite of the numerous liposomes reviews published in the last decades, this area is in constant development. Updates urgently needed to integrate new advances in targeted liposomes research. This review highlights the evolution of liposomes from passive to active targeting and challenges in the development of targeted liposomes for specific therapies.

Peptide Anchor for Folate-Targeted Liposomal Delivery

Specific folate receptors are abundantly overexpressed in chronically activated macrophages and in most cancer cells. Directed folate receptor targeting using liposomes is usually achieved using folate linked to a phospholipid or cholesterol anchor. This link is formed using a large spacer like polyethylene glycol. Here, we report an innovative strategy for targeted liposome delivery that uses a hydrophobic fragment of surfactant protein D linked to folate. Our proposed spacer is a small 4 amino acid residue linker. The peptide conjugate inserts deeply into the lipid bilayer without affecting liposomal integrity, with high stability and specificity. To compare the drug delivery potential of both liposomal targeting systems, we encapsulated the nuclear dye Hoechst 34580. The eventual increase in blue fluorescence would only be detectable upon liposome disruption, leading to specific binding of this dye to DNA. Our delivery system was proven to be more efficient (2-fold) in Caco-2 cells than classic systems where the folate moiety is linked to liposomes by polyethylene glycol.

Folic acid-tagged protein nanoemulsions loaded with CORM-2 enhance the survival of mice bearing subcutaneous A20 lymphoma tumors

Folic Acid (FA)-tagged protein nanoemulsions were found to be preferentially internalized on B-cell lymphoma cell line (A20 cell line), which, for the first time, is reported to express folate receptor (FR)-alpha. Carbon monoxide releasing molecule-2 (CORM-2) was incorporated in the oil phase of the initial formulation. FA-functionalized nanoemulsions loaded with CORM-2 exhibited a considerable antitumor effect and an increased survival of BALB/c mice bearing subcutaneous A20 lymphoma tumors. The developed nanoemulsions also demonstrated to be well tolerated by these immunocompetent mice. Thus, the results obtained in this study demonstrate that FA-tagged protein nanoemulsions can be successfully used in cancer therapy, with the important ability to delivery drugs intracellularly.

FROM THE CLINICAL EDITOR

In this research, the authors developed folic acid tagged nanoemulsions containing a carbon monoxide releasing protein molecule for targeted cancer cell treatment. In-vitro and in-vivo experiments showed efficacy against B-cell lymphoma cells. The same nanocarrier platform could be applied to other tumor cells expressing folate receptors on the cell surface.

Liquid-based cytology and cell block immunocytochemistry in veterinary medicine: comparison with standard cytology for the evaluation of canine lymphoid samples

Liquid-based Cytology (LBC) consists of immediate wet cell fixation with automated slide preparation. We applied LBC, cell block (CB) and immunocytochemistry to diagnose canine lymphoma and compare results with conventional cytology. Samples from enlarged lymph nodes of 18 dogs were collected and fixed in preservative solution for automated slide preparation (LBC), CB inclusion and immunophenotyping. Two CB techniques were tested: fixed sediment method (FSM) and agar method (AM). Anti-CD79a, anti-Pax5, anti-CD3 and anti-Ki67 were used in immunocytochemistry. LBC smears showed better nuclear and nucleolar definition, without cell superposition, but presented smaller cell size and worse cytoplasmic definition. FSM showed consistent cellular groups and were employed for immunocytochemistry, while AM CBs presented sparse groups of lymphocytes, with compromised analysis. Anti-Pax-5 allowed B-cell identification, both in reactive and neoplastic lymph nodes. Our preliminary report suggests that LBC and FSM together may be promising tools to improve lymphoma diagnosis through fine-needle aspiration.

Ureia e glicerina bruta como aditivos na ensilagem de cana-de-açúcar

Objetivou-se avaliar a inclusão de ureia e glicerina bruta como aditivos na ensilagem da cana-de-açúcar, na composição químico-bromatológica, pH, N-amoniacal (N-NH3) e digestibilidade in vitro (DIV). Os tratamentos foram quatro doses de ureia, 0, 10, 20 e 30 g de ureia por kg de cana-de-açúcar na ensilagem, e cinco doses de glicerina bruta, 0, 10, 20, 30 e 40g de glicerina bruta por kg de cana-de-açúcar na ensilagem. As silagens foram armazenadas por 180 dias. O tratamento com ureia afetou a maioria das variáveis relacionadas ao valor nutritivo, aumentando os teores de matéria seca (MS) e proteína (PB) (2,58; 7,76; 18,70 e 19,31%), reduzindo os teores de fibra em detergente neutro (FDN) e melhorando a DIV da MS (42,61; 48,53; 50,69 e 51,18%) e FDN (38,81; 39,23; 41,06 e 43,46%), e as características fermentativas da silagem, apresentando valores de pH de 3,49; 3,86; 4,18 e 3,93 e de N-NH3 de 1,72; 3,80; 7,88 e 9,00, para as dose de 0, 10, 20 e 30 g, respectivamente. A glicerina bruta aumentou os teores de MS e extrato etéreo (1,45; 3,03; 3,62; 3,41 e 4,38%), melhorou a DIV da MS com valores de 49,61; 52,24; 53,28; 55,60 e 56,09% e reduziu perdas por gases durante o processo de fermentação, apresentando médias de 6,69; 5,97; 5,89; 5,51 e 5,48% da MS para as doses 0, 10, 20, 30 e 40g, respectivamente. Assim, a ureia e a glicerina bruta podem ser utilizadas como aditivos na ensilagem da cana-de-açúcar.

Fontes de amido no concentrado de bovinos superprecoces de diferentes classes sexuais

Objetivou-se avaliar duas fontes de amido (milho ou sorgo) no concentrado e três classes sexuais sobre o consumo de nutrientes, o desempenho e as características da carcaça de bovinos superprecoces. Foram utilizados 30 animais cruzados Beefalo-Nelore, com peso corporal médio inicial de 234,38±26,17kg, em delineamento inteiramente ao acaso, em esquema fatorial 2x3 (duas fontes de amido e três classes sexuais: fêmeas, machos castrados e machos não castrados). O período experimental foi de 224 dias. Na fase inicial (zero-17 semanas), os ganhos de peso total (GPT) e diário (GMD) foram 150,62 e 108,62kg e 1,27 e 0,91kg/dia, respectivamente, para milho e sorgo. Na fase final (17-32 semanas), houve efeito da fonte de amido para o peso de carcaça, com médias de 273,00 e 231,95kg, respectivamente, para os tratamentos com milho e sorgo. Houve efeito de classe sexual para GP, GMD e eficiência alimentar, com médias de GP iguais a 98,17, 124,70 e 119,70kg, GMD de 0,93, 1,19 e 1,14kg/dia e 8,66, 12,24 e 11,09%, respectivamente, para fêmeas, machos castrados e machos não castrados. Espessura de gordura subcutânea (EGS) apresentou médias de 10,50; 5,97 e 5,51mm, respectivamente, para fêmeas, machos castrados e machos não castrados. Recomenda-se o milho como fonte de amido na fase inicial do confinamento de superprecoces. Na fase final (17-32 semanas), não há distinção entre milho ou sorgo. As fêmeas apresentaram maior EGS, e os machos, castrados e não castrados, apresentaram maior eficiência alimentar na fase final do confinamento.

Improved renal function after kidney transplantation is associated with heme oxygenase-1 polymorphism

Heme oxygenase-1 (HO-1) has a microsatellite polymorphism based on the number of guanosine-thymidine nucleotide repeats (GT) repeats that regulates expression levels and could have an impact on organ survival post-injury. We correlated HO-1 polymorphism with renal graft function. The HO-1 gene was sequenced (N = 181), and the allelic repeats were divided into subclasses: short repeats (S) (<27 repeats) and long repeats (L) (>/=27 repeats). A total of 47.5% of the donors carried the S allele. The allograft function was statistically improved six months, two and three yr after transplantation in patients receiving kidneys from donors with an S allele. For the recipients carrying the S allele (50.3%), the allograft function was also better throughout the follow-up, but reached statistical significance only three yr after transplantation (p = 0.04). Considering only those patients who had chronic allograft nephropathy (CAN; 74 of 181), allograft function was also better in donors and in recipients carrying the S allele, two and three yr after transplantation (p = 0.03). Recipients of kidney transplantation from donors carrying the S allele presented better function even in the presence of CAN.

GHRH proliferative action on somatotrophs is cell-type specific and dependent on Pit-1/GHF-1 expression

To investigate the mechanisms by which the hypothalamic peptide GHRH influences cell division, we analyzed its effects on the proliferation of two different cell lines: CHO-4, an ovary-derived cell line, and GH3, a pituitary-derived cell line. We found that GHRH induces the proliferation of pituitary-derived cells but inhibits the proliferation of ovary-derived cells. We further characterized this dual effect of GHRH to find that the cytoplasmic signals induced by this hormone are similar in both cell lines. Moreover, in CHO-4 cells GHRH stimulates two well-known positive cell cycle regulators, c-myc and cyclin D1, but is unable to induce the degradation of the negative cell cycle regulator p27(Kip1). Significantly, when the Pit-1/GHF-1 gene is exogenously expressed in CHO-4 cells, the negative effect of GHRH on the proliferation of these cells is attenuated. Furthermore, when the levels of Pit-1 are downregulated by siRNA in GH3-GHRHR cells, the positive effects of GHRH on the proliferation of these cells are diminished. These findings add to our understanding of the molecules involved in the regulation of cell proliferation by GHRH, as we demonstrate for the first time that Pit-1 is not only required to drive the expression of the GHRH receptor, as previously described, but is also needed for the downstream effects that occur after its activation to modulate cell proliferation. These data suggest that the regulation of cell proliferation in response to a specific growth factor depends in certain cell populations on the presence of a tissue-specific transcription factor.

Incidence of donor and recipient toll-like receptor-4 polymorphisms in kidney transplantation

Toll-like receptors (TLR) comprise an emerging family that recognize pathogen-associated molecular patterns and promote the activation of leukocytes. Recently, TLR has been demonstrated to play a role in experimental allograft rejection. However, the TLR-4 gene has a polymorphism that can be associated with a blunted immune response, especially to microbial pathogens. We sought to study the incidence of TLR 4 gene variants among renal transplant donors and recipients from living and deceased organs and then to correlate them with short-term and long-term outcomes.

METHODS

Analysis of TLR4 polymorphisms at Asp299Gly and Thr399Ile codons were performed using restriction fragment length polymorphism. Demographic data was obtained from patient records.

RESULTS

Among 201 patients, 141 were recipients from related donors (group 1) and 60 recipients from 45 deceased donors (group 2). Patients were followed for 108 +/- 85 months after transplantation. The incidence of polymorphism for TLR-4 Asp299Gly, Thr399Ile or both were 8.9% in recipients and 8.0% in donors. Patients who received a kidney with polymorphism, Asp299Gly, or Thr399Ile, or both, did not show a difference in rate of acute tubular necrosis compared with controls (no polymorphism). Acute rejection occurred in 17.6% of recipients with Asp299Gly/Thr399Ile polymorphisms and in 39.5% of wild-type recipients (P = .400). The incidence of bacterial infection was equal in both groups.

CONCLUSION

The incidence of polymorphism in this study was similar in both groups, and donor or recipient polymorphisms were not associated with different renal graft outcomes.

L-Phenylalanine–4-nitrophenol (1/1)

In the 1:1 adduct formed between L-phenylalanine and 4-nitrophenol [alternative IUPAC name: (2S)-2-ammonio-3-phenylpropanoate-4-nitrophenol (1/1)], C9H11NO2.C6H5NO3, the L-phenylalanine molecule is in the zwitterionic state. The overall structure is stabilized via strong hydrogen bonding between polar zones and van der Waals interactions between non-polar zones, which alternate with the polar zones.

Supramolecular structure and second harmonic generation in strontium bis(hydrogenL-malate) hexahydrate

The title compound, tetraaquabis(hydrogen L-malato)strontium(II) dihydrate, [Sr(C4H5O5)2(H2O)4].2H2O, is a new non-linear optical semi-organic material with a second harmonic generation efficiency approximately 3.5 times greater than that of potassium dihydrogen phosphate. The malate anions are interconnected through directional O-H...O hydrogen bonding, in a head-to-tail arrangement, creating extended anionic chains along [001]. Neighbouring parallel chains are crosslinked by water molecules, resulting in a three-dimensional architecture. The Sr2+ ion is coordinated by eight O atoms. This material is a new candidate for non-linear optical applications since the crystals are stable and easy to grow.

Efeito do creep feeding sobre o desempenho de bezerros e a eficiência reprodutiva de primíparas Nelore, em pastejo

Avaliou-se o efeito da suplementação de bezerros em sistema de creep feeding, em pastagens de Brachiaria brizantha, durante o período de amamentação, sobre o ganho médio diário (GMD), peso à desmama (PD) e taxa de gestação, em delineamento inteiramente ao acaso, utilizando 102 vacas Nelore (primíparas de baixa condição corporal ao início da estação de monta) e seus bezerros, divididos em dois grupos: T1 (n=52), não tratado e T2 (n=50), tratado com suplemento à base de 20% de PB e 75% de NDT. O consumo médio diário estimado no período foi 0,61kg de suplemento/bezerro/dia. Observaram-se diferenças entre T1 e T2 quanto ao PD (P<0,01) e GMD (P<0,05), com valores, respectivamente, de 155,10±2,72 e 163,80±2,53kg; e 0,59±0,015 e 0,64±0,014kg. A taxa de gestação não foi influenciada pelos tratamentos (P>0,05). A suplementação em creep feeding pode aumentar o GMD e o PD de bezerros Nelore, sem alterar a taxa de gestação de primíparas que iniciam a estação de monta com baixa condição corporal.

Self-similarity and protein chains

Fractal properties of 5526 different protein chains are investigated. Characteristic fractal behavior for different molecular systems is obtained from the fractal dimension analysis, which shows that the dimension is delta=2.47 . This dimension gives a measure of the protein compactness. The present finding indicates that the fractal analysis describes some structural properties of proteins and corroborates the explanation about multifractality in the energy hypersurface.

Efeito de aditivos biológicos comerciais na silagem de capim-elefante (Pennisetum purpureum Schum)

Avaliaram-se o pH e a composição bromatológica de silagens de capim-elefante var. Napier, sem e com três aditivos biológicos comerciais (B, C e D) em duas concentrações de diluição, a recomendada pelo fabricante (concentração 1) ou com o dobro (concentração 2), feitas em microsilos de PVC. O delineamento experimental foi inteiramente ao acaso, com sete tratamentos e seis repetições por tratamento. Apenas o aditivo B em ambas as concentrações (3,73; 4,07) foi eficiente em reduzir (P<0,05) o pH em relação ao tratamento-controle (5,01). A porcentagem de matéria seca aumentou (P<0,05) com o uso do aditivo B, nas concentrações 1 (29,9) e 2 (31,3), e dos aditivos C e D, na concentração 2 (26,8; 25,7). Quanto à proteína bruta, somente houve diferença (P<0,05) entre o tratamento-controle (6,6) e os dois tratamentos com aditivo B (13,4; 12,09). As frações de fibra em detergente neutro e lignina foram menores (P<0,05) nos tratamentos com aditivo B em relação ao tratamento-controle. A duplicação da dose do aditivo B não aumentou sua eficiência. Nos macro-elementos cálcio e fósforo das silagens, todos os aditivos elevaram a concentração de cálcio e não alteraram a de fósforo. Concluiu-se que o aditivo B, constituído de Lactobacillus plantarum e Pediococcus acidilactici, melhorou tanto a qualidade de fermentação quanto o valor nutritivo da silagem de capim-elefante, e que a duplicação da concentração dos produtos não aumentou (P<0,05) a qualidade das silagens.

Tamanho de vacas Nelore adultas e seus efeitos no sistema de produção de gado de corte

Utilizaram-se 20 vacas adultas paridas, confinadas em piquetes-baias com cochos individualizados para vaca e para bezerro, com o objetivo de se estudar características relacionadas às medidas esqueléticas, peso e condição corporais e seus efeitos sobre o sistema de produção. Avaliou-se o tamanho das vacas com base em medidas de altura da cernelha (1,40±0,03m), altura da garupa (1,40±0,04m), perímetro torácico (1,84±0,04m), comprimento corporal (1,38±0,13m), área corporal (4,6m²) e peso corporal (442,70±29,9kg). As características relacionadas às medidas de tamanho apresentaram correlações entre si de média a alta magnitude. A área corporal se apresentou altamente correlacionada com as demais características. Em razão da variabilidade do peso corporal, sugere-se sua mensuração com outras medidas lineares relacionadas com o tamanho corporal com vistas à determinação do tamanho corporal mais adequado.

Synthesis, structure, thermal and non-linear optical properties of L-argininium hydrogen selenite

L-Argininium hydrogen selenite (C(6)H(15)N(4)O(2)HSeO(3)) is a new semiorganic compound of the hydrogen selenite family with non-linear optical properties. The crystal lattice is monoclinic with unit-cell parameters a = 22.493 (5), b = 5.1624 (13), c = 9.730 (4) A, beta = 95.68 (3) degrees, V = 1124.3 (6) A(3), Z = 4, space group C2. Second-harmonic generation measurements performed on powder samples, using a Q-switched Nd:Yag laser (lambda = 1064 nm), showed the second-harmonic power to be about twice that of urea. Differential scanning calorimetry measurements revealed the existence of a phase transition with onset at 289 K.

Multifractality, Levinthal paradox, and energy hypersurface

Multifractal properties in the potential energy hypersurface of polypeptides and proteins are investigated. Characteristic multifractal behavior for different molecular systems is obtained from the f(alpha) spectra. The analysis shows that the dimension of the phase space of the problem influences the accessibility to different parts of the potential energy hypersurface. Also, we show that it is necessary to take into account the H-bond formation between amino acids in the conformational-folding search. The present findings indicate that the f(alpha) function describes some structural properties of a protein. The behavior of the f(alpha) spectra gives an alternative explanation about the Levinthal paradox. Furthermore, the anomalous temperature dependence of the Raman spin-lattice relaxation rates can be related to the perturbations in the secondary structures.

[Genotypic resistance to antiretroviral drugs in patients with therapeutic failure to highly active antiretroviral therapy]

BACKGROUND

To assess genotypic resistance mutations in patients with virological failure with highly active antiretroviral therapy (HAART) METHODS: Genotyping of reverse transcriptase (RT) and protease (PRO) HIV-1 genes were carried out in 33 adherent patients failing on HAART.

RESULTS

Resistance mutations were found in 32 of the 33; 27 of them (81.8%) being primary mutations: 26 (78.8%) in the RT gene and 60 (60.6%) in the PRO gene. Overall, 66.6% had genotypic resistance to two drugs and 60.6% showed resistance to drugs belonging to the two main classes of antiretroviral drugs. At the time of treatment failure, 72.7% had on their therapeutic regimen one antiretroviral drug to which they had resistance mutations, 48.5% had genotypic resistance to two drugs of the therapeutic regimen and 21.2% to three drugs.

CONCLUSIONS

Most adherent patients failing on HAART carry drug resistant genotypes. These patients may constitute a reservoir of multidrug resistant HIV that may limit treatment options in the future.

Possible association between cytomegalovirus infection and gastrointestinal bleeding in hemophiliac patients

Cytomegalovirus (CMV) infection is of major concern in immunocompromised and immunosuppressed patients. Prior to the introduction of HIV-1 antibody screening and efficient virucidal processes to inactivate viruses, individuals with a factor VIII or factor IX deficiency had a high risk of contracting HIV-1 infection through the infusion of contaminated blood products. In addition, blood products were also frequently associated with alterations in immune function. This study investigated the frequency of active CMV infection and its clinical relevance in Brazilian hemophiliacs. One hundred hemophiliacs were screened for the presence of CMV-DNA in their blood using nested PCR. Twenty-five out of 100 patients (25%) were positive for CMV-DNA and 24 of these 100 patients (24%) were HIV-1 positive; 6 of these 24 (25%) were positive for CMV-DNA. A similar frequency was observed among HIV-1-negative patients. In 60 hemophiliacs, the clinical relevance of the CMV infection was assessed. Twenty-one patients were positive for CMV-DNA. Of these, 10 had gastrointestinal bleeding compared to only 9 of 39 patients who were CMV-DNA negative (p = 0.05; chi(2) test). These data indicate a high prevalence of active CMV infection in Brazilian hemophiliac patients, irrespective of whether the patients were or were not infected by HIV-1. There was a possible association between the presence of CMV and the occurrence of gastrointestinal bleeding.

Hypnotic, anticonvulsant and muscle relaxant effects of Rubus brasiliensis. Involvement of GABA(A)-system

Rubus brasiliensis hexanic fraction induced anxiolysis in rodents, which was reversed by flumazenil, a specific GABA(A)-benzodiazepine receptor antagonist (Nogueira et al., 1998a,b). Then, we investigated if this hexanic fraction was able to induce hypnotic, anticonvulsant and muscle relaxant effects, and the involvement of GABA(A)-system. The hexanic fraction (50, 100, 150 and 300 mg/kg, vo) was administered to male Swiss mice, 30 min before the tests. Only the dose of 300 mg/kg of this fraction decreased the latency and increased sleeping time in the barbituric-hypnosis test (sodium pentobarbital, 30 mg/kg, ip), prevented the pentylenetetrazol seizures (70 mg/kg, ip) and induced muscle relaxant (inclined plane) in 100% of animals. These effects were reversed by flumazenil (3 mg/kg, ip).

IN CONCLUSION

(1) R. brasiliensis hexanic fraction induced hypnotic, anticonvulsant and muscle relaxant effects, in mice, and the GABA(A)-benzodiazepine receptor may play an important role in the effects of this fraction; (2) it is strongly suggested that this fraction contains a benzodiazepine-like principle.

Involvement of GABA(A)-benzodiazepine receptor in the anxiolytic effect induced by hexanic fraction of Rubus brasiliensis

To investigate the ability of hexanic ethanolic fraction of Rubus brasiliensis Martius (Roseceae), to induce anxiolytic effect and also the possible involvement of the GABA(A)-benzodiazepine receptor complex, male Wistar rats and Swiss mice behaviour were tested in the elevated plus maze (EPM). All the doses of the extract, 50, 100 and 150 mg/kg, administered per gavage (vo), 30 min before the behavioural evaluation, induced an anxiolytic effect expressed by: increased number of entries in and time spent in the open arms and percentage of open arm entries; and decreased number of entries and time spent in the closed arms. The treatment of mice with flumazenil (Ro 15-1788), 0.5, 1.0 and 1.5 mg/kg, i.p., 15-min before the administration of hexanic fraction, 100 mg/kg, vo, blocked the hexanic fraction-induced anxiolytic effect. The LD50 for the hexanic fraction was 1512 mg/kg. In conclusion, it was shown that the hexanic fraction of R. brasiliensis induced an anxiolytic effect in rats and mice. This effect can be attributed to a liposoluble principle with low toxicity which may be acting as an agonist on GABA(A)-benzodiazepine receptor complex.

Anxiolytic effect of Rubus brasilensis in rats and mice

The aim of the present work was to investigate if infuse and ethanolic extracts (aqueous, butanolic and wax fractions) of Rubus brasiliensis Martius (Rosaceae) induce anxiolytic effect. The extracts were administered to male Wistar rats and Swiss mice per oral route, at 50, 100 and 150 mg/kg, 30 min before the behavioral evaluation in the elevated plus maze (EPM). Both infuse and wax ethanolic fraction at the dosage 150 mg/kg, vo, increased the number and the percentage of open arm entries of rats and mice. The aqueous and butanolic fractions, obtained from ethanolic extract, failed to induce anxiolytic effect. The treatment of mice with flumazenil (Ro 15-1788), 1.5, 2.0 and 2.5 mg/kg, i.p., 15-min before the administration of infuse or wax fraction, 150 mg/kg, vo, blocked the infuse or wax fraction-induced anxiolytic effect. The LD50 for the wax fraction was 1000 mg/kg. In conclusion, the infuse and wax ethanolic fraction of R. brasiliensis present anxiolytic effect in rats and mice. In addition, it is suggested that the anxiolytic effect may be attributed at least to one liposoluble principle with low acute toxicity which may be acting as an agonist on GABA(A)-benzodiazepine receptor complex.

Activation of TRK genes in Ewing's sarcoma. Trk A receptor expression linked to neural differentiation

Trk receptors have been identified by immunohistochemical methods in primitive neuroectodermal tumor (PNET)/Ewing's sarcoma (ES). However, the presence of different members of the Trk family of receptors in PNET/ES has not been specified. We have examined whether Trk A, B, and C receptors are specifically expressed in ES both with and without features of neural differentiation. Ten ES tumors (five primary tumors of bone and five extraosseous tumors transplanted into nude mice) were investigated for expression of Trk receptors by immunohistochemistry and reverse transcription-polymerase chain reaction. One primary ES and the five grafted ES tumors exhibited signs of neural differentiation; the remaining four primaries were undifferentiated ES. Other tumor types were analyzed as controls; they included three neuroblastomas (NB), two lymphomas, and single cases of pheochromocytoma (PHEO), schwannoma (SCHW), osteosarcoma, and carcinoma of breast, colon, and kidney. Trk receptors were detected in paraffin-embedded tumor tissue sections by means of a pan-Trk polyclonal antibody raised against the 14 carboxy-terminal residues of gp140trk, and trk A, B, and C transcripts were specifically detected by polymerase chain reaction-based amplification on cDNAs derived from tumor RNA with MuLV reverse transcriptase. Reactivity to the pan-Trk antibody was exhibited by six ES tumors, the three NBs, and the single PHEO and SCHW cases; immunoreactivity was restricted to differentiated tumors, in the case of ES. Tumor types positive for immunostaining were also distinguished by containing transcripts of TRK genes. However, the trk A, B, and C expression pattern of ES differed from that of NBs, PHEO, and SCHW. Transcripts of trk A, B, and C were detected in seven, four, and one case of ES, respectively, and in five, two, and five cases of NB, PHEO, and SCHW, respectively. Interestingly, all differentiated ES tumors contained trk A transcripts. Tumors of neuroectodermal phenotype and/or derivation were thus characterized by a distinct consensus expression pattern: trk A+/B-/C+ for differentiated ES and trk A+/B-/C+ for NB-PHEO-SCHW. These results indicate that the TRK gene family is frequently activated in ES; they also suggest that Trk A receptor is a feature of ES with neural differentiation, whereas Trk B and C receptors seem to be present in undifferentiated ES.

[Streptokinase in severe pulmonary thromboembolism]

Severe pulmonary embolism (PE) was treated with streptokinase in four patients, three men and one woman, age 38 to 72 (mean = 53 +/- 14) years. Before the thrombolytic therapy, all patients had pulmonary angiogram and hemodynamic parameters analyzed. The drug was infused through the distal lumen of the Swan-Ganz catheter at the pulmonary artery trunk. The initial dosage was 250,000 units "in bolus" and 100,000 units in 24 to 72 hours. The time interval between the symptoms and treatment had ranged from 2 hours to 5 days. The results are analyzed as follow: reduction on right atrial pressure, mean pulmonary pressure, pulmonary vascular resistance, an increase in the stroke volume and cardiac output. In two cases we observed total lysis, in one partial lysis and one patient died from severe form of PE and late infusion of SK. Reinfusion of the drug was necessary in one patient that had PE recurrence with reliable final result. Finally, no one had severe bleeding despite the use of the intrapulmonary catheter.