Emergence of Spinons in Layered Trimer Iridate Ba_{4}Ir_{3}O_{10}.

Spinons are well known as the elementary excitations of one-dimensional antiferromagnetic chains, but means to realize spinons in higher dimensions is the subject of intense research. Here, we use resonant x-ray scattering to study the layered trimer iridate Ba_{4}Ir_{3}O_{10}, which shows no magnetic order down to 0.2 K. An emergent one-dimensional spinon continuum is observed that can be well described by XXZ spin-1/2 chains with a magnetic exchange of ∼55 meV and a small Ising-like anisotropy. With 2% isovalent Sr doping, magnetic order appears below T_{N}=130 K along with sharper excitations in (Ba_{1-x}Sr_{x})_{4}Ir_{3}O_{10}. Combining our data with exact diagonalization calculations, we find that the frustrated intratrimer interactions effectively reduce the system into decoupled spin chains, the subtle balance of which can be easily tipped by perturbations such as chemical doping. Our results put Ba_{4}Ir_{3}O_{10} between the one-dimensional chain and two-dimensional quantum spin liquid scenarios, illustrating a new way to suppress magnetic order and realize fractional spinons.

Phenolic substances and cyanogenesis in galled and non-galled tissue of the fern species Microgramma vacciniifolia / Substâncias fenólicas e cianogênese em tecidos galhados e não galhados da samambaia Microgramma vacciniifolia

Galls, neo-formed plant structures that can occur in different organs, are generated by species-specific interaction with an inducing organism. Inducers manipulate the metabolism of its host. Microgramma vacciniifolia (Langsd. & Fisch.) Copel. is a Neotropical epiphytic fern that hosted two stem galls, one induced by a midge species (Diptera) and other by a micromoth species (Lepidoptera). The aim of this study was to evaluate the impact of these two gall-inducing insects on the biochemistry of phenolic acids and the cyanogenesis in galls, stems and leaves of M. vacciniifolia. High performance liquid chromatography (HPLC) indicated a total of 14 phenol derivatives, including caffeic and coumaric acid. Principal Coordinates Analysis (PCoA) of the phenolic substances indicated three groups consisting (1) non-galled stems and micromoth-induced galls; (2) midge-induced galls; (3) midge induced galls with parasitoids. Regarding the frequency of cyanogenesis assessed by the picrate paper test, the chi-squared test showed significant difference between fertile leaves (8.3%), sterile leaves (27.7%), non-galled stems (0%) and galls. Among galls, only the midge-induced galls analyzed were cyanogenic (15%). Our results indicated that the different gall-inducers (midge and micromoth) promote species-specific alterations to the phenolic substance composition of the host fern.

Galhas são estruturas vegetais neo-formadas que ocorrem em diferentes órgãos. Elas são geradas por uma interação espécie-específica com um organismo indutor. Os indutores manipulam o metabolismo do hospedeiro. Microgramma vacciniifolia (Langsd. & Fisch.) Copel. é uma samambaia epífita neotropical que hospeda duas galhas caulinares, uma induzida por uma espécie de mosquito (Diptera) e outra por uma micromariposa (Lepidoptera). O objetivo deste estudo foi avaliar o impacto desses dois insetos indutores de galhas na bioquímica dos ácidos fenólicos e da cianogênese em galhas, caules e folhas de M. vacciniifolia. Em análise de cromatografia líquida de alta eficiência (CLAE) foi possível indicar a presença de um total de 14 derivados fenólicos, incluindo ácido cafeico e ácido cumárico. Análise das Coordenadas Principais (ACoP) indicou três grupos (1) caules não galhados e galhas induzidas pela micromariposa; (2) galhas induzidas pelo mosquito; (3) galhas induzidas pelo mosquito com parasitoides. Em relação a frequência da cianogênese analisada com o teste do papel picrato, o teste do qui-quadrado apresentou diferença significativa entre as folhas férteis (8,3%), folhas estéreis (27,7%), caules não galhados (0%) e galhas. Entre as galhas, somente aquelas induzidas pelo mosquito foram cianogênicas (15%). Os resultados encontrados indicam, ao menos para as substâncias fenólicas, que os insetos indutores de galha (mosquito e micromariposa) promovem alterações espécie-específica na composição química da samambaia hospedeira.

Phenolic substances and cyanogenesis in galled and non-galled tissue of the fern species Microgramma vacciniifolia

Abstract Galls, neo-formed plant structures that can occur in different organs, are generated by species-specific interaction with an inducing organism. Inducers manipulate the metabolism of its host. Microgramma vacciniifolia (Langsd. & Fisch.) Copel. is a Neotropical epiphytic fern that hosted two stem galls, one induced by a midge species (Diptera) and other by a micromoth species (Lepidoptera). The aim of this study was to evaluate the impact of these two gall-inducing insects on the biochemistry of phenolic acids and the cyanogenesis in galls, stems and leaves of M. vacciniifolia. High performance liquid chromatography (HPLC) indicated a total of 14 phenol derivatives, including caffeic and coumaric acid. Principal Coordinates Analysis (PCoA) of the phenolic substances indicated three groups consisting (1) non-galled stems and micromoth-induced galls; (2) midge-induced galls; (3) midge-induced galls with parasitoids. Regarding the frequency of cyanogenesis assessed by the picrate paper test, the chi-squared test showed significant difference between fertile leaves (8.3%), sterile leaves (27.7%), non-galled stems (0%) and galls. Among galls, only the midge-induced galls analyzed were cyanogenic (15%). Our results indicated that the different gall-inducers (midge and micromoth) promote species-specific alterations to the phenolic substance composition of the host fern.

Resumo Galhas são estruturas vegetais neo-formadas que ocorrem em diferentes órgãos. Elas são geradas por uma interação espécie-específica com um organismo indutor. Os indutores manipulam o metabolismo do hospedeiro. Microgramma vacciniifolia (Langsd. & Fisch.) Copel. é uma samambaia epífita neotropical que hospeda duas galhas caulinares, uma induzida por uma espécie de mosquito (Diptera) e outra por uma micromariposa (Lepidoptera). O objetivo deste estudo foi avaliar o impacto desses dois insetos indutores de galhas na bioquímica dos ácidos fenólicos e da cianogênese em galhas, caules e folhas de M. vacciniifolia. Em análise de cromatografia líquida de alta eficiência (CLAE) foi possível indicar a presença de um total de 14 derivados fenólicos, incluindo ácido cafeico e ácido cumárico. Análise das Coordenadas Principais (ACoP) indicou três grupos (1) caules não galhados e galhas induzidas pela micromariposa; (2) galhas induzidas pelo mosquito; (3) galhas induzidas pelo mosquito com parasitoides. Em relação a frequência da cianogênese analisada com o teste do papel picrato, o teste do qui-quadrado apresentou diferença significativa entre as folhas férteis (8,3%), folhas estéreis (27,7%), caules não galhados (0%) e galhas. Entre as galhas, somente aquelas induzidas pelo mosquito foram cianogênicas (15%). Os resultados encontrados indicam, ao menos para as substâncias fenólicas, que os insetos indutores de galha (mosquito e micromariposa) promovem alterações espécie-específica na composição química da samambaia hospedeira.

Phenolic substances and cyanogenesis in galled and non-galled tissue of the fern species Microgramma vacciniifolia / Substâncias fenólicas e cianogênese em tecidos galhados e não galhados da samambaia Microgramma vacciniifolia

Galls, neo-formed plant structures that can occur in different organs, are generated by species-specific interaction with an inducing organism. Inducers manipulate the metabolism of its host. Microgramma vacciniifolia (Langsd. & Fisch.) Copel. is a Neotropical epiphytic fern that hosted two stem galls, one induced by a midge species (Diptera) and other by a micromoth species (Lepidoptera). The aim of this study was to evaluate the impact of these two gall-inducing insects on the biochemistry of phenolic acids and the cyanogenesis in galls, stems and leaves of M. vacciniifolia. High performance liquid chromatography (HPLC) indicated a total of 14 phenol derivatives, including caffeic and coumaric acid. Principal Coordinates Analysis (PCoA) of the phenolic substances indicated three groups consisting (1) non-galled stems and micromoth-induced galls; (2) midge-induced galls; (3) midgeinduced galls with parasitoids. Regarding the frequency of cyanogenesis assessed by the picrate paper test, the chi-squared test showed significant difference between fertile leaves (8.3%), sterile leaves (27.7%), non-galled stems (0%) and galls. Among galls, only the midge-induced galls analyzed were cyanogenic (15%). Our results indicated that the different gall-inducers (midge and micromoth) promote species-specific alterations to the phenolic substance composition of the host fern.

Galhas são estruturas vegetais neo-formadas que ocorrem em diferentes órgãos. Elas são geradas por uma interação espécie-específica com um organismo indutor. Os indutores manipulam o metabolismo do hospedeiro. Microgramma vacciniifolia (Langsd. & Fisch.) Copel. é uma samambaia epífita neotropical que hospeda duas galhas caulinares, uma induzida por uma espécie de mosquito (Diptera) e outra por uma micromariposa (Lepidoptera). O objetivo deste estudo foi avaliar o impacto desses dois insetos indutores de galhas na bioquímica dos ácidos fenólicos e da cianogênese em galhas, caules e folhas de M. vacciniifolia. Em análise de cromatografia líquida de alta eficiência (CLAE) foi possível indicar a presença de um total de 14 derivados fenólicos, incluindo ácido cafeico e ácido cumárico. Análise das Coordenadas Principais (ACoP) indicou três grupos (1) caules não galhados e galhas induzidas pela micromariposa; (2) galhas induzidas pelo mosquito; (3) galhas induzidas pelo mosquito com parasitoides. Em relação a frequência da cianogênese analisada com o teste do papel picrato, o teste do qui-quadrado apresentou diferença significativa entre as folhas férteis (8,3%), folhas estéreis (27,7%), caules não galhados (0%) e galhas. Entre as galhas, somente aquelas induzidas pelo mosquito foram cianogênicas (15%). Os resultados encontrados indicam, ao menos para as substâncias fenólicas, que os insetos indutores de galha (mosquito e micromariposa) promovem alterações espécie-específica na composição química da samambaia hospedeira.

Phenolic substances and cyanogenesis in galled and non-galled tissue of the fern species Microgramma vacciniifolia.

Galls, neo-formed plant structures that can occur in different organs, are generated by species-specific interaction with an inducing organism. Inducers manipulate the metabolism of its host. Microgramma vacciniifolia (Langsd. & Fisch.) Copel. is a Neotropical epiphytic fern that hosted two stem galls, one induced by a midge species (Diptera) and other by a micromoth species (Lepidoptera). The aim of this study was to evaluate the impact of these two gall-inducing insects on the biochemistry of phenolic acids and the cyanogenesis in galls, stems and leaves of M. vacciniifolia. High performance liquid chromatography (HPLC) indicated a total of 14 phenol derivatives, including caffeic and coumaric acid. Principal Coordinates Analysis (PCoA) of the phenolic substances indicated three groups consisting (1) non-galled stems and micromoth-induced galls; (2) midge-induced galls; (3) midge-induced galls with parasitoids. Regarding the frequency of cyanogenesis assessed by the picrate paper test, the chi-squared test showed significant difference between fertile leaves (8.3%), sterile leaves (27.7%), non-galled stems (0%) and galls. Among galls, only the midge-induced galls analyzed were cyanogenic (15%). Our results indicated that the different gall-inducers (midge and micromoth) promote species-specific alterations to the phenolic substance composition of the host fern.

Responses of Crepis japonica induced by supplemental blue light and UV-A radiation.

Crepis japonica (L.) D.C. (Asteraceae), a weed with antioxidant, antiallergenic, antiviral and antitumor properties displays both medicinal properties and nutritional value. This study aims to assess the effects of a supplementation of blue light and UV-A radiation on the growth, leaf anatomical structure and phenolic profile of the aerial parts of Crepis japonica. Plants were grown under two light treatments: W (control - white light), W + B (white light supplemented with blue light) and W + UV-A (white light supplemented with UV-A radiation). We recorded the length, width, and weight of fresh and dry leaves, the thickness of the epidermis and mesophyll, and stomata density. The phenolic profiles of the aqueous extracts of the aerial parts were analyzed by HPLC-DAD. There was an increase in the leaf size, stomatal density, and phenolic production, and a thickening of the mesophyll and epidermis. UV-A radiation increased the phenolic production more than blue light. Blue light and UV-A radiation both improved the production of caffeic acid by about 6 and 3 times, respectively, in comparison to control. This compound was first reported as a constituent of the extract from the aerial parts together with caftaric acid. UV-A also promoted the production of chlorogenic acid (about 1.5 times in comparison to the control). We observed that the morphological and chemical parameters of C. japonica are modified in response to blue light and UV-A radiation, which can be used as tools in the cultivation of this species in order to improve its medicinal properties and nutritional value.

Engagement em docentes do ensino superior: uma abordagem exploratória / Level of engagement in university professors: An exploratory focus / Nivel de compromiso en docentes universitarios. Un enfoque exploratorio

Objetivo Caracterizar o perfil de um grupo de docentes da área da saúde, de uma escola de ensino superior privada do norte de Portugal, com relação ao vigor, dedicação e absorção na sua atividade profissional. Método Estudo descritivo exploratório transversal, enquadrado no paradigma quantitativo. Participaram 99 docentes. Utilizou;se um questionário estruturado com variáveis sociodemográficas, socioprofissionais e a escala do bem;estar Utrech Work Engagement Scale (UWES). A análise dos dados foi realizada usando SPSS versão 20. O tratamento estatístico compreendeu uma análise descritiva e, numa segunda fase, procedeu;se à com testes paramétricos e não paramétricos para um nível de significância de 0,05. Resultados Comprovou;se que os docentes revelaram elevados níveis de vigor, dedicação e absorção, e, destas dimensões, destacou;se a dedicação. Conclusões Os docentes estão comprometidos. São física, cognitiva e emocionalmente envolvidos com as suas atividades profissionais, o que se traduz em um indicador positivo favorável para a organização onde exercem funções.

Objective To estimate the level of engagement of a group of university professors teaching subjects of the health area in a private high;level education school in northern Portugal. The analyzed domains were vigor, dedication, and involvement in the professional activity. Method This is an exploratory, descriptive, and transversal study framed in the quantitative paradigm. Ninety nine professors participated. A structured questionnaire with social, demographic, and professional variables, along with the Ultrech Work Engagement Scale, was used. Data analysis was performed using SPSS version 20. Statistical analysis program included a descriptive analysis and a second phase, were processed with parametric and nonparametric tests for a significance level of 0.05. Results Findings reveal that these professors showed high levels of vigor, dedication, and involvement-particularly of dedication. Conclusions These professors are engaged as they are physically, cognitively, and emotionally involved with their professional activities; and this is translated into a positive indicator for their education organization.

Objetivo Caracterizar el perfil de un grupo de docentes del área de la salud de una escuela de enseñanza superior privada del norte de Portugal, en relación con el vigor, dedicación y absorción en su actividad profesional. Método Estudio exploratorio descriptivo transversal enmarcado en el paradigma cuantitativo. Participaron 99 profesores. Se utilizó un cuestionario estructurado con variables sociodemográficas, socioprofesionales y la escala de Bienestar Ultrech Work Engagement Scale (UWES). El análisis de datos se realizó mediante el programa SPSS versión 20. El análisis estadístico comprende un análisis descriptivo y en la segunda fase se aplicaron pruebas paramétricas y no paramétricas para un nivel de significancia de 0,05. Resultados Se comprobó que los maestros revelaron altos niveles de vigor, dedicación y absorción, destacó sobre todo la dedicación. Conclusiones Los maestros están comprometidos. Son física, cognitiva y emocionalmente comprometidos con sus actividades profesionales lo que se traduce en un indicador positivo favorable para la organización donde ejercen funciones.

Influence of radiopacity of dental composites on the diagnosis of secondary caries: the correlation between objective and subjective analyses.

This study aimed to objectively evaluate the radiopacity of different dental composites and their subjective influence on diagnosing secondary caries-like lesions and how these results correlate. For objective analysis, three resin specimens (1 mm thick, with a 4-mm internal diameter) were made with four composites: 1) Charisma; 2) Filtek Z250; 3) Prisma AP.H; and 4) Glacier. Three human teeth were selected and then mesio-distally sectioned (1 mm thick) to make the dental specimens. An aluminum (Al) wedge (12 steps, 1 mm thick, 99.8% purity) was used as an internal standard to calculate the radiopacity. For subjective analysis, 20 human teeth were selected and then prepared with a mesio-occluso-distal (MOD) inlay cavity, with half the teeth receiving a round cavity to simulate the carious lesion. The MOD was restored using the composites at four different times. Standardized radiographs were acquired and then digitized (300 dpi and eight-bit TIFF) for both analyses. A histogram objectively measured the pixel intensity values of the images, which were converted into millimeters of Al using linear regressions. Eight observers subjectively evaluated the images using a five-point rating scale to diagnose the caries. The data were statistically analyzed using the Student t-test, the Kappa test, diagnostic testing, and the Pearson correlation coefficient (α=0.05). All materials showed radiopacity values compatible with dental tissues (p>0.05); Glacier was similar to dentin and Prisma AP.H was similar to enamel, while the remaining materials showed a middle radiopacity. Prisma AP.H and Glacier differed (p<0.05) in relation to their accuracy to caries diagnosis, with Glacier having greater accuracy. There was a correlation between objective and subjective analyses with negative linear dependence. An increase in the material's radiopacity could have a subjectively negative influence on the diagnosis of secondary caries; thus, an ideal radiopacity for a dental composite is closer to the dentin image and produces similar attenuation to X-rays than does dentin.

Salmonella typhimurium em linfonodos mesentéricos de ovinos ao abate / Presence of Salmonella typhimurium in ovine mesenteric lymph nodes at slaughter

O rebanho de ovinos no Brasil está estimado em mais de 16 milhões de cabeças. Embora o consumo da carne desta espécie ainda seja pequeno, comparado ao de outros países, o consumo de carne, inclusive ovina, tem sido associado às doenças transmitidas por alimentos, em especial a salmonelose. No presente estudo, investigou-se a ocorrência de salmonelas em linfonodos mesentéricos e conteúdo intestinal de 175 ovinos ao abate. "Pools" constituído por cinco amostras de contéudo fecal ou 5 amostras de linfonodos de 25 g foram pre-enriquecidos em 250 mL de água peptonada tamponada e incubados a 37° C por 18-24 horas. Uma alíquota de 0,1 mL do préenriquecimento foi transferida para 9,9 mL de caldo de enriquecimento Rappaport-Vassiliadis e 1,0 mL do pré-enriquecimento foi transferido para 10 mL de caldo tetrationato Muller-Kaufmann, incubados a 42° C for 24h. 10 µL do caldo de enriquecimento foi semeado superfície de placas de ágar BPLS e ágar XLT4 incubadas a 37º C for 24-48h. Colônias suspeitas de salmonela foram testadas por provas bioquímicas e serologicas. Os testes bioquímicos utilizados para identificação de Salmonella foram TSI (triple sugar iron àgar), LIA (lysine iron àgar) e ágar ureia. Sorotipagem foi realizada no Laboratório de Enterobactérias do Instituto Osvaldo Cruz. Isolou-se Salmonella Tiphymurium de um pool de linfonodos mesentéricos, provenientes de cinco animais. O fato de se observar a ocorrência de salmonela em ovino portador sadio alerta para necessidade de monitorar este micro-organismo também nesta espécie, especialmente quando destinada ao abate, com vistas à produção de alimentos seguros.

The ovine flock in Brazil is estimated at over 16 million head. Despite that meat consumption of this species is still small when compared to other countries, general meat consumption, including mutton, has been associated to food borne diseases, especially salmonellosis. In the present study, the occurrence of salmonella in mesenteric lymph nodes and intestinal content of 175 ovines during slaughter was investigated. A pool of 5 feces samples or 5 lymph node samples of 25 grams was pre-enriched in 250 mL of buffered peptone water at 37° C for 18-24h. Following this, 0.1 mL of pre-enriched broth was transferred to 9.9 mL of Rappaport-Vassiliadis enrichment broth and 1.0 mL of pre-enriched broth was transferred to 10 mL of Muller-Kaufmann tetrationate broth, incubated at 42° C for 24h. Then, a 10 µL of the enrichment broth was spread on the surface of a BPLS and an XLT4 plate, both incubated at 37º C for 24-48h. Suspected Salmonella colonies were picked from the agar and tested with biochemical and serological methods. Biochemical testing was carried out for the identification of Salmonella, using the TSI (triple sugar iron agar), LIA (lysine iron agar) and urea agar tests. Serotyping was done at the Laboratory of Enterobactérias of the Instituto Osvaldo Cruz. Salmonella Tiphymurium was isolated from a pool of mesenteric lymph nodes from 5 animals. That Salmonella was observed in healthy carrier ovines points out the necessity of monitoring this microorganism in this species as well, especially when animals are destined to slaughter, so to assure safe food production.

Autoantibodies specificity in acute anterior uveitis according to the presence of the HLA-B27 allele.

PURPOSE: To study HLA-B27(+) and HLA-B27(-) patients with AAU with respect to the frequency and specificity of organ-specific and non-organ-specific autoantibodies. METHODS: Fifty-seven consecutive patients with AAU were subjected to ophthalmologic and rheumatologic evaluation as well as to autoantibody determination: antinuclear antibodies (ANA), rheumatoid factor (RF), anticardiolipin, anti-smooth muscle, and anti-parietal cell antibodies, and immunoblot for antibodies to HeLa cells and to bovine iris extract. HLA-B27 was determined by a microlymphocytotoxicity assay. Statistical analysis employed chi-square test, Fisher's exact test, and McNemar test. RESULTS: Thirty-four patients had the HLA-B27 allele (B27(+)/AAU) and 23 did not (B27(-)/AAU). ANA, RF, anticardiolipin, and anti-parietal cell antibodies appeared in low frequency. No patient presented anti-smooth muscle antibody. Immunoblot showed a high frequency of antibodies to HeLa cell proteins in B27(-)/AAU patients with predominant reactivity at 46 kDa and 56 kDa. In contrast, sera from B27(+)/AAU patients reacted poorly against HeLa cell antigens. Immunoblot with bovine iris extract showed a significant frequency of antibodies in both groups, with a predominant response to antigens with an estimated mobility of 35, 52, and 54 kDa. CONCLUSION: Antibodies specific to iris antigens were equally frequent in both acute uveitis groups, whereas non-organ-specific autoantibodies, especially those to HeLa cell proteins, were far less frequent in B27(+)/AAU than in B27(-)/AAU patients.

Staying on top of TB's rise.

Delays in acid-fast bacillis (AFB) emergency department admissions prompted a revised multidisciplinary rounds process for weekends and holidays; AFB isolation cases dropped 10%.

Nitric oxide as a signal in thyroid.

It is now well established that agonist activation of the PIP2/calcium cascade in the thyroid results in the enhancement of cGMP accumulation presumably by activation of the soluble guanylate cyclase. In many tissues the physiological signal controlling soluble guanylate cyclase is nitric oxide (NO) and its synthesis from arginine is controlled by the intracellular Ca2+. In this report we show results that suggest that NO may be the intermediate of the cGMP response to the activation of the PIP2/calcium cascade. In dog thyroid slices, incubation with carbamylcholine or A23187 increases significantly free intracellular Ca2+ levels and the cGMP content of the slices. NG-Monomethyl-L-arginine (NMMA), a competitive inhibitor of arginine for nitric oxide synthase, inhibited these cGMP responses but not the action of sodium nitroprusside which activates soluble guanylate cyclase directly. The inhibition was relieved by arginine. Methylene blue, which blocks the activation of soluble guanylate cyclase by NO, also decreased the three stimulatory effects. NMMA and methylene blue also decreased the basal levels of cGMP. NO may therefore be an important autocrine and paracrine factor in thyroid.

Transgenic mice expressing a mutant keratin 10 gene reveal the likely genetic basis for epidermolytic hyperkeratosis.

Epidermolytic hyperkeratosis (EH; previously called bullous congenital ichthyosiform erythroderma) is an autosomal dominant skin disease of unknown etiology, affecting approximately 1 out of 300,000 people. It is typified by hyperkeratotic scaliness, blistering due to cytolysis within suprabasal epidermal cells, and hyperproliferation in basal cells. Histologically, EH epidermis exhibits a thickened stratum corneum and granular layer, with enlarged and irregular-shaped cells. Ultrastructurally, only suprabasal layers are affected, with three major aberrancies: (i) tonofilament clumping, (ii) nuclei and keratohyalin granules of irregular shape and size, and (iii) cell degeneration. We have discovered that transgenic mice expressing a mutant keratin 10 gene have the EH phenotype, thereby suggesting that a genetic basis for human EH residues in mutations in genes encoding suprabasal keratins K1 and K10. In addition, we show that (i) stimulation of basal cell proliferation can arise from a defect in suprabasal cells, and (ii) distortion of nuclear shape or aberrations in cytokinesis can occur when an intermediate filament network is perturbed.

92-kD type IV collagenase mediates invasion of human cytotrophoblasts.

The specialized interaction between embryonic and maternal tissues is unique to mammalian development. This interaction begins with invasion of the uterus by the first differentiated embryonic cells, the trophoblasts, and culminates in formation of the placenta. The transient tumor-like behavior of cytotrophoblasts, which peaks early in pregnancy, is developmentally regulated. Likewise, in culture only early-gestation human cytotrophoblasts invade a basement membrane-like substrate. These invasive cells synthesize both metalloproteinases and urokinase-type plasminogen activator. Metalloproteinase inhibitors and a function-perturbing antibody specific for the 92-kD type IV collagen-degrading metalloproteinase completely inhibited cytotrophoblast invasion, whereas inhibitors of the plasminogen activator system had only a partial (20-40%) inhibitory effect. We conclude that the 92-kD type IV collagenase is critical for cytotrophoblast invasion.

[Cineventriculography with radionuclides and intravenous dipyridamole in the prognostic evaluation after acute myocardial infarction]. / Cineventriculografia com radionuclídeos e dipiridamol venoso na avaliação prognóstica após infarto agudo do miocárdio.

PURPOSE: To evaluate safety and usefulness of dipyridamole-radionuclide ventriculography (D-RVG), soon after acute myocardial infarction (MI), in the prediction of future cardiac events. Traditionally performed tests were also compared. PATIENTS AND METHODS: Forty-one patients (4 females) with recent MI underwent rest and dipyridamole (0.58 mg/kg of body weight) radionuclide ventriculography. The criteria for a positive test for ischemia was failure to increase left ventricular ejection fraction in 0.05 from baseline value. All patients had also coronary angiography and 36 patients underwent thallium-201 scintigraphy for comparison. The mean follow-up was 16 +/- 3 months. The following findings were considered future for events: cardiac death, reinfarction, significant angina or heart failure. RESULTS: During the follow-up 18 of the 20 patients who had cardiac events had shown positive dipyridamole-RVG, as opposed to 5 of 21 event-free patients (p less than 0.01). The ventriculographic criteria for a positive test and dipyridamole left ventricular ejection fraction were the strongest predictors of those medical events (p less than 0.01 and p less than 0.001). Among the 36 patients who had thallium-201 imaging, 16 subsequently had cardiac events and the scans were positive in 82% (p less than 0.01). Twelve (29%) patients experienced reactions during dipyridamole infusion although no fatal complications were noted. CONCLUSION: Dipyridamole-RVG is relatively safe and a sensitive predictor of future cardiac events soon after acute MI, although additional experience is required before this new technique should be routinely recommended as an alternative approach.

Invagination of the otic placode: normal development and experimental manipulation.

The inner ear forms from paired ectodermal primordia that lie to either side of the developing hindbrain. Initially each primordium forms a shallow depression in the ectodermal surface. Invagination to form an otic pit coincides with the formation of several deep folds in the epithelial surface. An initial fold appears parallel to the embryonic axis and at the junction of the rhombencephalon with somitomeric mesoderm. This is followed by formation of cranial and caudal folds perpendicular to the axis and minor folds that are within the pit formed by earlier folding. The central region of the otic primordium remains in close apposition to the lateral surface of the neural tube during the process of fold formation, until the otic pit becomes quite deep. At that time, mesenchymal cells penetrate between the two layers. Experimental analysis of invagination supports the conclusion that otic invagination is controlled differently from that of similar organ primordia, such as the eye and thyroid. Whereas these other primordia can be stimulated to undergo normal morphogenetic shape changes precociously by treatments that presumably activate motile processes in the cytoskeleton, the same conditions have little effect on the otic placode. Similarly, neither inhibitors of calcium transport nor inactivators of calmodulin activity prevent otic pit formation, while these drugs block invagination of other primordia. These results suggest that otic invagination may be caused by changes in the surrounding tissues rather than by an activation of motility within the primordium.

Doenca de Basedow-Graves: grave comprometimento sistemico cutaneo e ocular. / Basedow-Graves' disease: severe systemic cutaneous and ocular involvement

Os autores apresentam dois casos de oftalmopatia infiltrativa de Graves-Basedow em sua forma mais grave e exuberante associada a dermopatia (mucinosis cutis: tanto na forma localizada - mixedema pre-tibial, como na forma tuberosa intensa) e a acropaquia tireotoxica. Discutem a etiopatogenia de cada uma dessas condicoes e consideram as varias medidas terapeuticas locais e sistemicas preconizadas nesses casos

Manifestacoes bucais das doencas profissionais. / Oral manifestations of occupational diseases

Diante da necessidade decorrente da nao participacao do cirurgiao-dentista na equipe de Saude Ocupacional, a autora apresenta uma serie de situacoes nas quais ocorrem manifestacoes bucais em razao da acao dos agentes quimicos, responsaveis pela maioria das dermatoses ocupacionais.O principal proposito do presente artigo e alertar o medico do trabalho para a necessidade de se realizarem exames minuciosos da cavidade bucal em seus pacientes, para que possam ser detectadas patologias bucodentarias decorrentes ou nao das dermatoses ocupacionais, adotando-se providencias nos casos em que fizerem necessarias, e minimizando, assim, problemas odontologicos numerosos e relevantes, uma vez que a Odontologia Ocupacional ainda nao e considerada especialidade odontologica

Contribuicao dos metodos radiomarcados na avaliacao da funcao testicular. / Radioimmunoassay contribution to the evaluation of testicular function

A funcao androgenica no homem depende da sindrome da testosterona nas celulas de Leydig do testiculo, sob a influencia ganodotrofica do LH hipofisario, melhor denominado no homem ICSH (interstitial cell stimulating hormone).Entretanto, existe uma importante contribuicao da cortex supra-renal, atraves de esteroides C-19 oriundos da camada reticular e eliminados na urina - a semelhanca da testosterona - sob a forma de 17-cetosteroides neutros. A oportunidade de estudar maridos de casais estereis, selecionados pela normalidade do espermograma, permitiu-se reunir 50 observacoes de homens adultos, de idade conhecida, com dosagens de 17-cetosteroides urinarios (metodo quimico) e FSH, LH e testosterona plasmaticos (metodo RIA) na faixa de normalidade dos metodos respectivos. Foram avaliadas as principais correlacoes, concluindo-se pela existencia de significancia, em determinados limites, apenas da relacao LH/testosterona, o que seria de se esperar no quadro fisiologico conhecido. A fixacao de padroes de normalidade e logicamente o substrato basico para ulterior aplicacao propedeutica