Whole-body regeneration in the colonial tunicate Botrylloides leachii

The colonial marine invertebrate Botrylloides leachii belongs to the Tunicata subphylum, the closest invertebrate relatives to the vertebrate group and the only known class of chordates that can undergo whole-body regeneration (WBR). This dramatic developmental process allows a minute isolated fragment of B. leachii’s vascular system, or a colony excised of all adults, to restore a functional animal in as little as 10 days. In addition to this exceptional regenerative capacity, B. leachii can reproduce both sexually, through a tadpole larval stage, and asexually, through palleal budding. Thus, three alternative developmental strategies lead to the establishment of filter-feeding adults. Consequently, B. leachii is particularly well suited for comparative studies on regeneration and should provide novel insights into regenerative processes in chordates.Here, after a short introduction on regeneration, we overview the biology of B. leachii as well as the current state of knowledge on WBR in this species and in related species of tunicates. Finally, we highlight the possible future directions that research might take in the study of WBR, including thoughts on technological approaches that appear most promising in this context. Overall, we provide a synthesis of the current knowledge on WBR in B. leachii to support research in this chordate species

Charakterystyka wędlin oraz wędzonych i peklowanych produktów otrzymywanych z mięsa pre-rigor mortis w warunkach półprzemysłowych

In semi-technical conditions sausages were produced as well as cured and smoked hams and loins. There were found no significant differences in chemical composition of sausages from pre-rigor and chilled meat. Two groups of experimental sausages (fine and coarse comminution grade) were superior to those from chilled meat in respect to finał yield and organoleptic quality. Microorganism number found in experimental and control sausages did not exceed the industrial standards. Production of pre-rigor meat sausages consumed over twice less time than the traditional technology. In the case of products produced from intact muscles no satisfactory results were obtained. Experimental cured and smoked hams and Ioins were tougher, too succulent and not uniform in colour.W warunkach półprzemysłowych wyprodukowano z mięsa ciepłego kiełbasę drobno- oraz średniorozdrobnioną, szynkę wędzoną i polędwicę. Składniki peklujące dodano przed upływem 2 h od momentu kłucia zwierząt. Ocenę gotowych produktów przeprowadzono w oparciu o oznaczenie składu chemicznego, wydajności, wycieku termicznego, ilości drobnoustrojów i ocenę organoleptyczną. Pod względem składu chemicznego nie znaleziono różnic pomiędzy produktami z mięsa ciepłego i wychłodzonego. Kiełbasy z mięsa ciepłego oceniono jako lepsze ze względu na ich wydajność oraz ocenę organoleptyczną. Przy zastosowaniu nowej technologii nie zaobserwowano pogorszenia się stanu mikrobiologiocznego gotowych wyrobów, chociaż odkostnianie i rozdrabniane mięsa prowadzono w temperaturach wyższych niż tradycyjnie. Zawartość drobnoustrojów wahała się od 1,3 X 10⁵ do 3,5 X 10⁵ na 1 g i nie przekraczała wielkości określonych normami przemysłowymi. Przy użyciu ciepłego mięsa wołowego i wieprzowego możliwe było skrócenie cyklu produkcyjnego kiełbas ze 101 do 44 h. Mniej obiecujące wyniki uzyskano w przypadku produktów otrzymanych z nierozdrobnionych mięśni. Szynka wędzona i polędwica otrzymane z mięsa ciepłego nie miały wymaganej kruchości, wykazywały niską zdolność utrzymywania wody i niejednolitość barwy na przekroju. Wyraźną poprawę tych cech uzyskano po zastosowaniu masowania próżniowego szynek

TRICHOMONAS TENAX OCCURRENCE IN PATIENTS SUFFERING FROM PERIODONTITIS

The aim of this study was to assess the occurrence of Trichomonas tenax in individuals with periodontal disease and also to check the correlation between the occurrence of protozoan and a kind of periodontal disease, bleeding index and dental plaque index. The study involved 77 individuals aged 22-77 years (47 women and 30 men). Culture revealed flagellate Trichomonas tenax. The incidence of trichomonal infection was 32%. In spite of using two different media no Entamoeha gingivalis was found. There was no significant dependence between the frequency of occurrence of T. tenax and age, sex or smoking. There was a correlation between the occurrence of T. tenax and the amount of dental plaque (correlation index=0.3; p=0.06) and there was also a statistical dependence between the occurrence of T. tenax and a kind of periodontal disease (correlation index=0.3; p=0.02)

Schnurri mediates Dpp-dependent repression of brinker transcription.

Signalling by Decapentaplegic (Dpp), a member of the TGFbeta superfamily of signalling molecules, controls many aspects of Drosophila development by activating and repressing target genes. Several essential components of the Dpp signalling pathway have been identified, including the Dpp receptors Punt and Thick veins (Tkv) as well as the cytoplasmic mediators Mad and Medea. For target genes to be activated, Dpp signalling must suppress transcription of a repressor encoded by the brinker (brk) gene. Here we show that Schnurri (Shn), a large zinc-finger protein, is essential for Dpp-mediated repression of brk transcription; in contrast, Shn is not required for target-gene activation. Thus, the Dpp signalling pathway bifurcates, downstream of the signal-mediating SMAD proteins, into a Shn-dependent pathway leading to brk repression and a Shn-independent pathway leading to gene activation. The existence of several Shn-like proteins in vertebrates and the observation that Brk functions in BMP signalling in Xenopus indicates that a similar regulatory cascade may be conserved in higher organisms