Oxidative stress is involved in LLLT mechanism of action on skin healing in rats

The skin injury healing process involves the main phases of homoeostasis, inflammation, proliferation, and remodeling. The present study aimed to analyze the effects of low-level laser therapy (LLLT) on hematological dynamics, oxidative stress markers, and its relation with tissue healing following skin injury. Wistar rats were divided into control, sham, skin injury, and skin injury LLLT. The biochemical and morphological analyses were performed in the inflammatory (1 and 3 days) and regenerative phases (7, 14, and 21 days) following injury. The skin injury was performed in the dorsal region, between the intrascapular lines, using a surgical punch. LLLT (Al-Ga-In-P, λ=660 nm, energy density of 20 J/cm², 30 mW power, and a time of 40 s) was applied at the area immediately after injury and on every following day according to the experimental subgroups. LLLT maintained hematocrit and hemoglobin levels until the 3rd day of treatment. Surprisingly, LLLT increased total leukocytes levels compared to control until the 3rd day. The effects of LLLT on mitochondrial activity were demonstrated by the significant increase in MTT levels in both inflammatory and regenerative phases (from the 1st to the 7th day), but only when associated with skin injury. The results indicated that LLLT modulated the inflammatory response intensity and accelerated skin tissue healing by a mechanism that involved oxidative damage reduction mostly at early stages of skin healing (inflammatory phase).

Cryotherapy: biochemical alterations involved in reduction of damage induced by exhaustive exercise

When exercises are done in intense or exhaustive modes, several acute biochemical mechanisms are triggered. The use of cryotherapy as cold-water immersion is largely used to accelerate the process of muscular recovery based on its anti-inflammatory and analgesic properties. The present study aimed to study the biochemical effects of cold-water immersion treatment in mice submitted to exercise-induced exhaustion. Swiss albino mice were divided into 4 treatment groups: control, cold-water immersion (CWI), swimming exhaustive protocol (SEP), and SEP+CWI. Treatment groups were subdivided into times of analysis: 0, 1, 3, and 5 days. Exhaustion groups were submitted to one SEP session, and the CWI groups submitted to one immersion session (12 min at 12°C) every 24 h. Reactive species production, inflammatory, cell viability, and antioxidant status were assessed. The SEP+CWI group showed a decrease in inflammatory damage biomarkers, and reactive species production, and presented increased cell viability compared to the SEP group. Furthermore, CWI increased acetylcholinesterase activity in the first two sessions. The present study showed that CWI was an effective treatment after exercise-induced muscle damage. It enhanced anti-inflammatory response, decreased reactive species production, increased cell viability, and promoted redox balance, which could decrease the time for the recovery process.

Soil factors effects on life history attributes of Leiothrix spiralis and Leiothrix vivipara (Eriocaulaceae) on rupestrian grasslands in Southeastern Brazil

In this study, we hypothesized that the life history traits of Leiothrix spiralis and L. vivipara would be linked to soil factors of the rupestrian grasslands and that rosette size would be influenced by soil moisture. Soil analyses were performed from five populations of L. spiralis and four populations of L. vivipara. In each area, three replicates were employed in 19 areas of occurrence of Leiothrix species, and we quantified the life history attributes. The microhabitats of these species show low favorability regarding to soil factors. During the dry season, their rosettes decreased in diameter due the loss of its most outlying leaves. The absence of seedlings indicated the low fecundity of both species. However, both species showed rapid population growth by pseudovivipary. Both L. spiralis and L. vivipara exhibit a kind of parental care that was quantified by the presence of connections between parental-rosettes and ramets. The findings of the present study show that the life history traits are linked to soil factors.

Life history, distribution and abundance of the giant earthworm Rhinodrilus alatus RIGHI 1971: conservation and management implications

Rhinodrilus alatus is an endemic giant earthworm of the Brazilian Cerrado hotspot used as live bait for about 80 years. The goal of this study was to gather ecological data about this species, which will support the establishment of management strategies. The life history, distribution and abundance of R. alatus were investigated in Cerrado, pastures and Eucalyptus plantation areas following the harvesting activities of the local extractors of this species. We found that this earthworm is abundant in all of the sampled areas, showing its resilience to land-use conversion. The Capture Per Unit Effort was 4.4 ± 5 individuals per 100 metres of transect and 5.6 ± 3 individuals per hour. The earthworm's annual cycle is markedly seasonal, with an aestivation period throughout the driest and coldest season of the year. Significant differences in the length and diameter of the body and in the diameter and depth of the aestivation chambers were found between the juveniles and adults. The distribution range of the species was expanded from two to 17 counties. The life history, abundance, distribution and resilience of R. alatus to certain perturbations are key elements to be considered in conservation and management strategies for this species.

Assessment of the correlation between two defining criteria for bidirectional isthmic block in the ablation of typical atrial flutter

BACKGROUND

A complete, bidirectional conduction block in the cavotricuspid isthmus (CTI) represents the end-point of the typical atrial flutter ablation. We investigated the correlation between two criteria for successful ablation, one based on the atrial bipolar electrogram morphology before and after complete CTI conduction block, compared to the standard criteria of differential pacing and reversal in the right atrial depolarization sequence during coronary sinus (CS) pacing.

METHOD

We conducted a retrospective study in 111 patients (81 males, average age 62±10 years) who underwent an atrial flutter ablation during September 2007 - July 2009 in the Cardiology - Rehabilitation Hospital, UMF Cluj-Napoca. We assessed the presence of a bidirectional block at the end of the procedure using the standard criteria. We then analyzed the morphology of the bipolar atrial electrograms adjacent to the ablation line, before and after CTI conduction block.

RESULTS

A change from a qRs morphology to a rSr' morphology when pacing from the coronary sinus and from a rsr' morphology to a QRS morphology when pacing from the low-lateral right atrium was associated with a CTI conduction block. Sensitivity (Se), specificity(Sp), positive predictive value (PPV), negative predictive value (NPV) were 96%, 89%, 99% and 67% respectively.

CONCLUSION

Our study suggests that the analysis of the atrial bipolar electrogram next to the ablation line before and after CTI ablation may be used as a reliable criterion to validate CTI conduction block due to its high sensitivity, specificity and positive predictive value.

An ultra-low-power filtering technique for biomedical applications

This paper describes an ultra-low-power filtering technique for biomedical applications designated as T-wave sensing in heart-activities detection systems. The topology is based on a source-follower-based Biquad operating in the sub-threshold region. With the intrinsic advantages of simplicity and high linearity of the source-follower, ultra-low-cutoff filtering can be achieved, simultaneously with ultra low power and good linearity. An 8(th)-order 2.4-Hz lowpass filter design example optimized in a 0.35-μm CMOS process was designed achieving over 85-dB dynamic range, 74-dB stopband attenuation and consuming only 0.36 nW at a 3-V supply.

In vitro lingual bracket evaluation of indirect bonding with plasma arc, LED and halogen light

OBJECTIVES

Evaluate the shear bond strength (SBS) and the adhesive remnant index (ARI) of indirect bonded lingual brackets using xenon plasma arc light, light-emitting diode (LED) and conventional quartz-tungsten-halogen light.

MATERIAL AND METHODS

Lingual brackets were bonded indirectly to 60 premolars divided to three groups according to the curing light used: Group 1, plasma arc for 6 s; Group 2, LED for 10 s; and Group 3, halogen light for 40 s. After bonding, the specimens were subjected to a shear force until debonding. The debonding pattern was assessed and classified according to the ARI scores. The mean shear bond strengths were accessed by anova followed by the Student-Newman-Keuls test for multiple comparisons. ARI scores were assessed using the chi-square test.

RESULTS

The three groups showed significant differences (p < 0.001), with the averages of group 1 < group 2 < group 3. Groups showed no differences regarding ARI scores.

CONCLUSION

Bonding lingual brackets indirectly with plasma arc, during 60% of the time used for the LED, produced lower SBS than obtained with the latter. Using LED during 25% of the time of the halogen light produced lower SBS than obtained with the latter. These differences did not influence the debonding pattern and are clinically acceptable according to the literature.

Candida flosculorum sp. nov. and Candida floris sp. nov., two yeast species associated with tropical flowers

Two ascomycetous yeast species, Candida flosculorum sp. nov. and Candida floris sp. nov., were isolated from tropical flowers and their associated insects. C. flosculorum was isolated from flower bracts of Heliconia velloziana and Heliconia episcopalis (Heliconiaceae) collected from two Atlantic rain forest sites in Brazil. C. floris was isolated from flowers of Ipomoea sp. (Convolvulaceae) growing on the banks of the river Paraguai in the pantanal ecosystem in Brazil and from an adult of the stingless bee Trigona sp. and a flower of Merremia quinquefolia (Convolvulaceae) in Costa Rica. C. flosculorum belongs to the Metschnikowiaceae clade and C. floris belongs to the Starmerella clade. The type strain of C. flosculorum is UFMG-JL13(T) (=CBS 10566(T)=NRRL Y-48258(T)) and the type strain of C. floris is UWO(PS) 00-226.2(T) (=CBS 10593(T)=NRRL Y-48255(T)).

Nuclear organization of the protamine locus

The human protamine gene cluster consists of three tightly regulated genes, protamine 1 (PRM1), protamine 2 (PRM2) and transition protein 2 (TNP2). Their products are required to repackage the paternal genome during spermiogenesis into a functional gamete. They reside within a single DNase I-sensitive domain associated with the sperm nuclear matrix, bounded by two haploid-specific Matrix Attachment Regions. The nuclear matrix is a dynamic proteinaceous network that is associated with both transcription and replication. While substantial effort has been directed toward pre- and post-transcriptional regulation, the role of the nuclear matrix in regulating haploid expressed genes has received comparatively little attention. In this regard, the functional organization of the human PRM1 --> PRM2 --> TNP2 cluster and where appropriate, comparisons to other model systems will be considered.

Seasonal timing of pseudoviviparous reproduction of Leiothrix (Eriocaulaceae) rupestrian species in South-eastern Brazil

BACKGROUND AND AIMS

Pseudovivipary is an asexual reproductive strategy. Leiothrix spiralis and L. vivipara (Eriocaulaceae) are pseudoviviparous and occur in rupestrian grasslands, a habitat that has a predominance of sandy and shallow soil, with low water retention. This study aims to investigate the seasonal variation effect of moisture availability on L. spiralis and L. vivipara pseudoviviparous reproduction, and to compare their life history attributes, on rupestrian grasslands in Southeastern Brazil.

METHODS

A field study was conducted, including observations concerning pseudoviviparous reproduction and measurement of demographic variables in both L. spiralis and L. vivipara. Soil moisture measurements were also performed to study its effect on the pseudoviviparous reproduction of L. spiralis and L. vivipara.

KEY RESULTS

Flower head and plantlet production in L. spiralis were highly correlated with soil moisture. All scapes split off in the drier period, indicating that this is a splitter ramet species. Plantlet mortality was positively correlated with scapes splitting off. The L. vivipara phenophases were not synchronized to the variation in soil moisture, since flower heads and plantlets were produced throughout the year. Moreover, the splitting off of scapes was not observed. In addition, plantlets were formed early, as soon as the flower heads appeared, and remained suspended. Therefore, this species was called 'canopy forming'.

CONCLUSIONS

Seasonal timing of pseudoviviparous reproduction can be a vital component of the successful establishment of plantlets in L. spiralis, considering that in this species the plantlets are formed only after the flower head touches the ground. In contrast, in L. vivipara, the plantlets are formed early, without touching the ground. Moreover, L. spiralis is a splitter ramet species, while L. vivipara is a canopy-forming species. The pseudoviviparous canopy-forming strategy appears to be more advantageous than the splitter ramet strategy, because even under similar soil moisture conditions, the survival of L. vivipara plantlets was greater than that of L. spiralis.

Floral preferences of a neotropical stingless bee, Melipona quadrifasciata Lepeletier (Apidae: Meliponina) in an urban forest fragment

Species of plants used by Melipona quadrifasciata Lepeletier for pollen and nectar gathering in an urban forest fragment were recorded in Belo Horizonte, Minas Gerais, Brazil. Melipona quadrifasciata visited 22 out of 103 flowering plant species. The plant species belonged mainly to Myrtaceae, Asteraceae, and Convolvulaceae (64% of the visits). Melipona quadrifasciata tended to collect pollen or nectar each time, except for Myrtaceae species, from which both pollen and nectar were collected. Bee abundance at flowers did not significantly correlate to food availability (expressed by flowering plant richness). We found a relatively high similarity (50%) between plant species used by M. quadrifasciata, which was also found in studies carried out in São Paulo State. However, low similarity (17%) was found between the results of this study and those of another done in Bahia State, Brazil.

An overview of proximate factors affecting the nesting behavior of solitary wasps and bees (Hymenoptera: Aculeata) in preexisting cavities in wood

Guilds of Aculeate solitary wasps and bees that nest in preexisting cavities in wood are important components of terrestrial ecosystems because they engage in several ecological interactions (e.g. predation and pollination) with other species of plants and animals. Spatial and temporal variations in richness and abundance of solitary wasps and bees can be related to changes in environmental structure and in the diversity of other groups of organisms. The nesting period of these Aculeata is their most critical life cycle stage. Females of solitary wasp and bee species invest relatively more time constructing and provisioning their nests than do females of social species. Differently from species that nest in the soil or construct exposed nests, the main factors affecting the reproductive success of solitary species nesting in preexisting wood holes are still unknown. Our objective is to provide an overview of the role of proximate causes of nesting failure or success among solitary wasps and bees (Aculeata), for designing effective conservation and management strategies for these Hymenoptera.

Trap-nest occupation by solitary wasps and bees (Hymenoptera: Aculeata) in a forest urban remanent

Temporal variation of solitary wasps and bees, nesting frequency, mortality, and parasitism were recorded from a remanent forest in Belo Horizonte, MG, Brazil. Wasps and bees were collected in trap-nests placed in areas with 25, 100, and 400 m2, from February to November 2004. The 137 trap-nests collected contained 11 species of wasps and bees. Wasps occupied most nests (75%). Occupation peaks occurred in March (25%) and September (26%); in June, the lowest occupation (2%) was observed. Except for Trypoxylon (Trypargilum) lactitarse Saussure, no significant correlation was found between number of occupied nests, and temperature and rainfall means. In the nests, 48% of the immature specimens died; 13% of the nests were parasitized. Total death and parasitism rates of wasps and bees differed significantly.

Candida riodocensis and Candida cellae, two new yeast species from the Starmerella clade associated with solitary bees in the Atlantic rain forest of Brazil

Two new ascomycetous yeast species belonging to the Starmerella clade were discovered in nests of two solitary bee species in the Atlantic rain forest of Brazil. Candida riodocensis was isolated from pollen-nectar provisions, larvae and fecal pellets of nests of Megachile sp., and Candida cellae was found in pollen-nectar provisions of Centris tarsata. Analysis of the sequences of the D1/D2 large-subunit ribosomal DNA showed that C. riodocensis is phylogenetically related to C. batistae, and the closest relative of C. cellae is C. etchellsii. The type strains are C. riodocensis UFMG-MG02 (=CBS 10087(T) = NRRL Y-27859(T)) and C. cellae UFMG-PC04 (=CBS 10086(T) = NRRL Y-27860(T)).

Characterization of the region encompassing the human lysyl oxidase locus

A 46,823 bp region of human chromosome 5q23.1 encompassing the seven-exon lysyl oxidase gene was characterized at the primary sequence level. Approximately 17.4% of this region is comprised of repetitive elements. The gene colocalizes with microsatellite marker D5S467. It is flanked by two candidate nuclear matrix association regions (MARs). The 5' MAR centered at position 12,500 is of the AT-rich and curved DNA class. This is followed by a large CpG island containing fifty-seven putative regulatory elements which extend from just upstream of exon 1 to intron 2. The larger 3' MAR, spans position 35,050-39,750 and is characterized by a TG-rich kinked structure that also contains a topoisomerase II binding site. Based on these results model of the transcriptional regulation of the lysy/oxidase gene is presented.

Characterizing a human lysyl oxidase chromosomal domain

The expression of each locus in our genome is regulated by a gene-potentiative mechanism, whereby the gene first assumes the necessary structural conformation to enable transcription. This serves as the corner-stone for the three-tiered regulatory mechanism of potentiation, i.e., the opening of a chromatin domain, initiation of transcription, and transcript elongation. Although this is now generally accepted as the pathway that mediates gene expression, it has never been shown directly to control the expression of any heart-related gene. Lysyl oxidase enzymatically crosslinks members of the extracellular matrix, including elastin and collagen. Formation of these structures is essential to development and tissue repair. This system has enabled us to begin to address the underlying mechanism governing the selection of connective tissue genes for expression. However, before one can dissect this mechanism, it is necessary to define and characterize the locus, i.e., the corresponding genic domain. Our progress toward creating the resources necessary to unravel this mechanism is summarized in this review.

A estrutura da guilda de abelhas e vespas visitantes florais de Waltheria americana L. (Sterculiaceae)

A fenologia floral de Waltheria americana L. (Sterculiaceae) e o número de espécies de angiospermas floridas foram quantificados em dois locais do Campus Pampulha da Universidade Federal de Minas Gerais em Belo Horizonte, Estação Ecológica (EE) e Prefeitura (PR). O objetivo foi avaliar a importância de W. americana como fornecedora de pólen e néctar para uma guilda de vespas e abelhas visitantes. Na estação chuvosa o número de espécies de angiospermas floridas foi maior que na estação seca, mas apresentou diferença significativa apenas na PR. Todavia, em ambas estações, nos dois locais, houve uma correlação positiva entre o número de flores em W. americana e o número de outras espécies floridas. Na PR o número de flores em W. americana foi significativamente maior na estação seca. O número de espécies de vespas visitantes de W. americana foi maior nos meses de abril a agosto de 1993 na PR e somente as abelhas mostraram variação na composição de espécies ao longo do período do estudo. Houve uma correlação positiva entre o número de visitas de abelhas, de flores em W. americana e o número de outras espécies floridas. Porém, não houve diferença no número médio de visitas entre as estações do ano. Por outro lado, não houve correlação entre o número de visitas de vespas, número de flores em W. americana e número de outras espécies floridas na EE. As vespas visitaram W. americana mais frequentemente, na estação chuvosa, na EE; o inverso ocorreu na PR. A visitação diária de vespas e abelhas foi mais intensa entre nove e 13 h. Por florescer todo o ano e ser uma fonte de néctar para abelhas e vespas, W. americana pode ser importante para ajudar a manter a estrutura da guilda de abelhas e vespas visitantes florais, as quais podem atuar como polinizadores e agentes de controle biológico em áreas agrícolas ou degradadas.

Potencial da erva daninha Waltheria americana (Sterculiaceae) no manejo integrado de pragas e polinizadores: visitas de abelhas e vespas

A quantificação anual da disponibilidade de flores de Waltheria americana, da riqueza em espécies e da taxa de visitação de abelhas e vespas às suas flores, permitiu avaliar o potencial dessa invasora para os programas de manejo integrado de pragas e de polinizadores. O estudo foi conduzido em dois locais do Campus da Universidade Federal de Minas Gerais - UFMG (Estação Ecológica e Prefeitura). Em cada local foram registrados mensalmente a produção de flores em 20 indivíduos desta planta, o número de espécies e de visitas de abelhas e vespas às suas flores. Trinta e sete espécies de abelhas e 72 espécies de vespas visitaram as flores de W. americana nos dois locais. A riqueza e o número de visitas de abelhas correlacionaram-se positiva e significativamente com o número de flores. Para as vespas, houve correlação da riqueza e do número de visitas, com o número de flores, apenas na Prefeitura. Uma grande proporção de espécies de abelhas e vespas, registradas em cada local, foi obtida em um único dia do mes. Bicyrtes angulata Smith e Ammophilla gracilis Lepeletier, foram as únicas espécies de vespas a visitarem durante os 12 meses e Augochloropsis callichroa Cockrell, foi a espécie de abelha mais freqüente, estando presente em 9 dos 12 meses de estudo. W. americana produz muitas flores, é fonte de néctar para abelhas e vespas e surge espontaneamente em áreas agrícolas e ambientes degradados, podendo por isso ter potencial para ser utilizada em programas de manejo integrado de polinizadores e controle biológico de pragas.