Phylogenetic relationships among the Caribbean members of the Cliona viridis complex (Porifera, Demospongiae, Hadromerida) using nuclear and mitochondrial DNA sequences

Species complexes - groups of closely related species in which intraspecific and interspecific variability overlap - have generated considerable interest and study. Frequently, members of a species complex do not have complete reproductive isolation; therefore, the complex may go through extensive gene flow. In the Caribbean Sea, some encrusting and excavating sponges of the genus Cliona (Porifera, Hadromerida, Clionaidae) are grouped within the great "Cliona viridis" complex because of their morphological similarities. This study examined the evolutionary relationships of the Caribbean members of this complex (C. caribbaea, C. tenuis, C. aprica and C. varians) and related taxa based on nuclear (ITS1 and ITS2) and mitochondrial (3' end of ND6) DNA sequences. The intragenomic ITS variation and its secondary structures were evaluated using a mixed approach of Denaturing Gradient Gel Electrophoresis (DGGE), DNA sequencing and secondary structure prediction. Considerable intragenomic variation was found in all the species, with apparently functional ITS1 and ITS2 secondary structures. Despite the subtle but clear morphological differentiation in these excavating sponges, the intragenomic copies of C. caribbaea, C. tenuis and C. aprica had a polyphyletic placement in the ITS1 and ITS2 genealogies and very low divergence. Therefore, it is clear that these species constitute a species complex (herein called Ct-complex). Genetic distances within the Ct-complex revealed that an important part of the interspecific variation overlapped with intraspecific variation, suggesting either incomplete lineage sorting or extensive gene flow. In contrast, C. varians and an unidentified "Pione" species emerged as monophyletic clades, being the closest sister groups to the Ct-complex. Additionally, our results support that C. laticavicola and C. delitrix conform a monophyletic group, but absence of reciprocal monophyly in these species suggests they may be life stages or ecophenotypes of a single species or they have diverged recently. Our work showed that the 3' end of the ND6 mitochondrial gene was highly conserved and not suitable for phylogenetic analysis at the interspecific level.     

Comparison among DNA polymerases 1, 2 and 3 from maize embryo axes. A DNA primase activity copurifies with DNA polymerase 2

Three DNA polymerase activities, named 1, 2 and 3 were purified from maize embryo axes and were compared in terms of ion requirements, optimal pH, temperature and KCl for activity, response to specific inhibitors and use of templates. All three enzymes require a divalent cation for activity, but main differences were observed in sensitivity to inhibitors and template usage: while DNA polymerases 1 and 2 were inhibited by N-ethyl maleimide and aphidicolin, inhibitors of replicative-type enzymes, DNA polymerase 3 was only marginally or not affected at all. In contrast, DNA polymerase 3 was highly inhibited by very low concentrations of ddTTP, an inhibitor of repair-type enzymes, and a 100-fold higher concentration of the drug was needed to inhibit DNA polymerases 1 and 2. Additionally, DNA polymerases 1 and 2 used equally or more efficiently the synthetic template polydA-oligodT, as compared to activated DNA, while polymerase 3 used it very poorly. Whereas DNA polymerases 1 and 2 shared properties of replicative-type enzymes, DNA polymerase 3 could be a repair-type enzyme. Moreover, a DNA primase activity copurified with the 8000-fold purified DNA polymerase 2, strenghtening the suggestion that polymerase 2 is a replicative enzyme, of the -type. This DNA primase activity was also partially characterized. The results are discussed in terms of relevant data about other plant DNA polymerases and primases reported in the literature.     

Early hyperglycemia following alloxan administration in vivo is not associated with altered hepatic mitochondrial function: acceptable model for type 1 diabetes?

Alloxan and oxidative stress, which have been detected in livers of laboratory animals shortly after in vivo alloxan administration, cause in vitro mitochondrial dysfunction, thus questioning alloxan diabetes as an acceptable model for type 1 diabetes, a model that cannot legitimately be used to investigate mitochondrial metabolism in a diabetic state. In the current study, the blood glucose concentration increased in the drug-treated group of Sprague-Dawley rats (compared with the placebo group) 45 or 60?min after alloxan treatment, whereas at 30?min the blood glucose concentration was unchanged. State 4, state 3, respiratory control, efficiency of oxidative phosphorylation, and mitochondrial ATP synthase activity, assayed using glutamate plus malate, pyruvate plus malate, or succinate as a substrate, were not negatively altered during the entire study. These results indicated that early increases of blood glucose concentration, after in vivo alloxan administration, did not lead to liver mitochondrial dysfunction, suggesting that alloxan diabetes can be used for the study of liver mitochondrial respiration in a diabetic state.     

Denture-related stomatitis managed with tissue conditioner and hard autopolymerising reline material

doi: 10.1111/j.1741–2358.2010.00398.x
Denture related stomatitis managed with tissue conditioner and hard autopolymerising reline material. Objective: To compare the response of denture‐related stomatitis (DS) under management with a tissue conditioner (TC) and autopolymerising hard reline material (AHRM). Background data: Denture‐related stomatitis affects up to 75% of denture wearers; not wearing the denture at night, using TC or prescribing topical or systemic antifungal agents could reduce its incidence. Materials and methods: This was a double‐blind study consisting of 44 participants with DS who wear denture; they were randomly divided into two unmatched groups according to the material used for the management of DS. The TC was replaced weekly, and the AHRM was placed at the beginning of the study and was not changed for 4 weeks. A dentist performed an initial and a weekly clinical diagnosis for DS; the clinical situation was recorded by means of photographs for each week. Results: Both TC and AHRM were effective in the management of DS. Significant differences were found in the DS resolution time (p < 0.001), taking longer for the TC. Conclusions: Both the tissue conditioner and AHRM are effective for the management of DS, but AHRM requires less time for recovery and as a result fewer appointments are required for the patient.     

Association between oral health, cognitive impairment and oral health-related quality of life

doi: 10.1111/j.1741‐2358.2011.00542.x
Association between oral health, cognitive impairment and oral health–related quality of life Objective: Investigating oral health–related quality of life’s (OH‐QoL) relationship with cognitive state. Background: Oral health affects OH‐QoL and is poor in institutionalised and cognitively impaired people. Material and Methods: This was a cross‐sectional study involving 215 institutionalised elderly (82.9 mean age), who were interviewed, examined and cognitively screened using the Pfeiffer test. Results: Mean GOHAI score was 53.1; only 43.7% of the participants reported having a good OH‐QoL. Needing help with dressing or washing (OR 2.14; p = 0.004), having one to nine teeth (OR 4.65; p ≥ 0.001), eight or less occluding pairs (OR 2.74; p = 0.002), one to three caries (OR 1.85; p = 0.005) and being cognitive impaired (OR 0.54; p = 0.034) were significantly associated with altered OH‐QoL in bi‐variate analysis. Being edentulous (OR 3.18; p = 0.0046), having 1–9 teeth (OR 2.62; p = 0.056) and presenting mild cognitive impairment (MCI) (OR 0.32; p = 0.016) appeared as predictive variables in logistic regression for having an altered OH‐QoL. Conclusions: Participants having MCI had significantly better GOHAI score than cognitively normal residents. Performing cognitive screening parallel to applying any OH‐QoL instrument would make the results more reliable and would benefit cognitively impaired people.     

Oral health in institutionalised elderly people in Oslo, Norway and its relationship with dependence and cognitive impairment

doi: 10.1111/j.1741‐2358.2011.00490.x
Oral health in institutionalised elderly people in Oslo, Norway and its relationship with dependence and cognitive impairment Objective: Investigating oral health’s relationship with dependency and cognitive state. Background: Oral hygiene is poor in the institutionalised elderly. There are problems regarding the oral care of residents having poor mobility or cognitive impairment. Material and methods: Cross‐sectional study involving 135 participants (mean age 85.7, SD 8.8 years) in two categories: nurses doing tooth cleaning and residents doing tooth cleaning. Those cleaned by nurses were categorised as co‐operative or unco‐operative. The oral hygiene status, presence of caries, retained roots and denture‐related stomatitis were recorded. Results: Of the participants, 70% had only natural teeth. The prevalence of caries was 28%. A significant correlation showed that having more teeth gave a poorer Simplified Oral Hygiene Index (OHI‐S) (p = 0.018). The number of retained roots increased with the severity of cognitive impairment (p < 0.05). Significant differences were found between nurses or residents doing the tooth cleaning on the OHI‐S (p = 0.05) and percentage of dental plaque (p = 0.003). Unco‐operative residents had poorer oral hygiene (p = 0.028), more caries (p = 0.008) and were more often moderate–severe cognitive impaired (p = 0.016). Conclusions: A high percentage of participants had unacceptable oral hygiene. Residents whose teeth were cleaned by the nurses had poorer oral hygiene. Unco‐operative residents had the worst oral hygiene and more caries.     

Dextran causes aggregation of mitochondria and influences their oxidoreductase activities and light scattering

It has been reported that dextrans diminish the intermembrane space of mitochondria, increase the number of contact sites between the inner and the outer mitochondrial membranes, decrease the outer membrane permeability to adenosine 5(')-diphosphate, and change the kinetic properties of mitochondrial kinases. In the present work the influence of dextran M40 (5% w/v) on the oxidoreductase activities of the inner and outer membranes of mitochondria, the interaction of cytochrome c with mitochondrial membranes, and the light scattering by rat liver mitochondria were studied. No influence of dextran on the release of cytochrome c from mitochondria or its interaction with mitochondrial membranes was observed. Decreases in the NADH-oxidase (to 80+/-2% of the control), NADH-cytochrome c reductase (to 26+/-2%), succinate-cytochrome c reductase (to 70+/-5%), and NADH-ferricyanide reductase (to 75+/-3%) activities induced by dextran, which may be due to the mitochondrial aggregation, were observed. The formation of aggregates was registered by light scattering, confirmed by light microscopy, and explained within the framework of the Gouy-Chapman theory of the electrical double layer. The observed mitochondrial aggregation seems to be useful also for understanding the mechanisms of mitochondrial condensation and perinuclear clustering during apoptosis.     

Nematodes associated with three indigenous leafy vegetables commonly grown in inland valley ecology in Nigeria

Field study was conducted between January and June 2011 to determine the plant-parasitic and non-parasitic nematodes associated with three indigenous leafy vegetables (Amaranthus viridis, Celosia argentea and Corchorus olitorius) commonly grown in inland valley by farm practical year students’ trainees at the Federal University of Agriculture, Abeokuta. The 1.76-ha land was laid out in randomised complete block design with four replicates. Six soil cores were taken per replicate and bulked. Two sub-samples weighing 250?g per replicate were assayed for nematodes using WhiteHead and Hemming Tray method. Results revealed the presence of five genera of plant-parasitic nematodes, namely Tylenchus, Pratylenchus, Helicotylenchus, Meloidogyne and Rotylenchulus. Populations of Tylenchus differed statistically (p?=?0.05) from all others in C. olitorius. The non-parasitic nematodes varied significantly (p?=?0.05) among the vegetable types. Galls incited by Meloidogyne spp. were more (p?=?0.05) in C. argentea and C. olitorius than A. viridis.