268 research outputs found
Free-Living Marine Interstitial Hypotrichid Ciliates from Jubail Marine Wildlife Sanctuary in the Arabian Gulf
Sediment samples were collected at low tide from various localities of the Jubail Marine Wildlife Sanctuary in the Arabian Gulf on several occasions during l996-l997 for the study of the marine interstitial ciliate fauna of the Sanctuary. Twenty three species belonging to the order Hypotrichida were identified after protargol impregnation, 20 of which represent new records of the fauna of Saudi Arabia, and of the Arabian Gulf at large. The distribution of each species is compared to those in similar habitats worldwide. The present study increases the total known number of hypotrichid ciliates species in Saudi Arabia to 40 species
Molecular Mechanisms of Peritoneal Dialysis–Induced Microvascular Vasodilation
Peritoneal dialysis (PD) solutions dilate microvessels
by undefined mechanisms. This vasodilation
directly affects ultrafiltration and solute exchange
during a PD dwell and is thought to account for the
variable mass transfer area coefficient for small
solutes during a glucose-based hypertonic dwell. We
hypothesized that PD-mediated vasodilation occurs
by endothelium-dependent mechanisms that involve
endothelium energy-dependent K+ channels (KATP),
adenosine A1 receptor activation, and NO release.
We used intravital videomicroscopy to study 3
levels of microvessels (A1 inflow arterioles about
100 μm diameter to pre-capillary A3 arterioles 10 –
15 ÎĽm diameter) in the terminal ileum of anesthetized
rats under control conditions in vivo in a tissue
bath. Ileum was bathed with hypertonic mannitol or
2.5% glucose-based PD solution (Delflex: Fresenius
Medical Care North America, Waltham, MA, U.S.A.)
with or without topical application of individual or
combined specific inhibitors of the endotheliumdependent
dilation pathways: NO (L-NMMA),
prostaglandin I2 (mefenamic acid), endothelium hyperpolarizing
factor (glibenclamide), and adenosine
A1 receptor antagonist (DPCPX).
The mannitol and PD solutions induced rapid and
sustained peritoneal vasodilation whose magnitude
depended on microvascular level and osmotic solute.
Combined inhibition of endothelium-dependent
dilation pathways completely abolished the mannitolinduced
hyperosmolality-mediated dilation at all
microvascular levels, but selectively eliminated the PD
solution–mediated A3 dilation. The KATP and adenosine
receptor antagonists, individually or combined,
remarkably attenuated dilation in the smaller pre-capillary
arterioles; NO inhibition, alone or combined with
KATP and adenosine receptor antagonists, eliminated
the PD solution–induced dilation. The cyclooxygenase
pathway is not involved in PD-induced dilation.
Solutions for PD dilate the visceral peritoneal
microvasculature by endothelium-dependent
mechanisms, primarily the NO pathway. Adenosine
receptor–activated NO release and KATP channelmediated
endothelium hyperpolarization significantly
contribute to vasodilation in the smaller peritoneal
pre-capillary arterioles.Qatar National Research Fund NPRP 09-268-3-06
Chronic elevation of systemic glucagon-like peptide-1 following surgical weight loss: association with nausea and vomiting and effects on adipokines.
We determined whether persistent nausea and vomiting (N/V) symptoms following Roux-en-Y gastric bypass surgery is due to elevated systemic glucagon-like peptide-1 (GLP-1) and leptin in female non-diabetic subjects. Subjects with N/V post-Roux-en-Y gastric bypass (RYGB) surgery had significantly elevated fasting GLP-1 levels compared to that with post-operative asymptomatic subjects and to morbidly obese, obese and lean subjects not undergoing surgery. Weight loss, glycaemia, insulin and post-prandial GLP-1 levels were similar in all post-operative subjects. Despite comparable BMI, leptin was significantly lower in symptomatic subjects. Furthermore, leptin secretion from subcutaneous adipose tissue was inhibited by GLP-1 (0.1-1.0 nM; n = 6). Persistent N/V following RYGB surgery is associated with elevated fasting GLP-1, but lower leptin levels. The latter may be a consequence of the direct GLP-1 inhibition of leptin secretion from adipose tissue
Design and Shape Optimization of Strain Gauge Load Cell for Axial Force Measurement for Test Benches
The load cell is an indispensable component of many engineering machinery and industrial automation for measuring and sensing force and torque. This paper describes the design and analysis of the strain gauge load cell, from the conceptional design stage to shape optimization (based on the finite element method (FEM) technique) and calibration, providing ample load capacity with low-cost material (aluminum 6061) and highly accurate force measurement. The amplifier circuit of the half Wheatstone bridge configuration with two strain gauges was implemented experimentally with an actual load cell prototype. The calibration test was conducted to evaluate the load cell characteristics and derive the governing equation for sensing the unknown load depending on the measured output voltage. The measured sensitivity of the load cell is approximately 15 mV/N and 446.8 µV/V at a maximum applied load of 30 kg. The findings are supported by FEM results and experiments with an acceptable percentage of errors, which revealed an overall error of 6% in the worst situation. Therefore, the proposed load cell meets the design considerations for axial force measurement for the laboratory test bench, which has a light weight of 20 g and a maximum axial force capacity of 300 N with good sensor characteristic
Redefinition and Reassignment of the 18-cirri Genera Hemigastrostyla, Oxytricha, Urosomoida, and Actinotricha (Ciliophora, Hypotricha), and Description of One New Genus and Two New Species
The morphology, the infraciliature, and two stages of physiological reorganization of Hemigastrostyla elongata spec. nov.,isolated from the Yellow Sea near Qingdao (China), are described. The new species differs from the type H. stenocephala, inter alia, by the length of the dorsal bristles and the position of the pretransverse ventral cirri; from H. enigmatica by the number of caudal cirri; and from H. para-enigmatica spec. nov. – established for the H. enigmatica populations from the Yellow Sea – by the arrangement of the postoral ventral cirri and the cortical granulation. A key to the Hemigastrostyla species and some other 18-cirri hypotrichs is provided. Hemigastrostyla szaboi is fixed as type species of Heterooxytricha gen. nov. because the type population lacks the extra cirri which are characteristic for Hemigastrostyla. In addition, Oxytricha geleii is assigned to this new genus, whose species have, like many oxytrichids, 18 frontal-ventraltransverse cirri, but a Gonostomum dorsal kinety pattern. The old, large, and difficult genus Oxytricha is briefly reviewed, mainly on the basis of the dorsal kinety pattern. Very likely, only species with the Oxytricha pattern belong to this genus. Oxytricha marcili and O. pseudofurcata, which have the Urosomoida kinety pattern (i.e. kinety 3 fragmentation lacking), are transferred to Urosomoida which is, inter alia, defined by a more or less distinctly reduced number of ventral and transverse cirri. Some other Oxytricha species with this kinety pattern (O. islandica, O. lanceolata, O. pseudosimilis, O. setigera) are not transferred to Urosomoida, but preliminarily classified as incertae sedis in Oxytricha, because they have the full set of 18 cirri. The available molecular data on O. lanceolata indicate that this type of 18-cirri hypotrichs likely needs a genus of its own because O. lanceolata does not cluster with O. granulifera, type of this genus. The marine Actinotricha saltans, classified for a very long time in Oxytricha, seems to be a non-dorsomarginalian hypotrich according to molecular data, justifying the reactivation of the old genus Actinotricha. Oxytricha shii has a multiple dorsal kinety 3 fragmentation, three dorsomarginal rows, and the undulating membranes arranged in the Cyrtohymena pattern, strongly indicating that it is a member of the subgenus Cyrtohymena (Cyrtohymenides). This brief review is a further step to unravel the complicated systematics of the old, but still little-known genus Oxytricha. The following new combinations are made in this paper: Cyrtohymena (Cyrtohymenides) shii (Shi et al., 1997) comb. nov.; Heterooxytricha szaboi (Wilbert and Song, 2005) comb. nov.; Heterooxytricha geleii (Wilbert, 1986) comb. nov.; Urosomoida marcili (Paiva and Silva-Neto, 2004) comb. nov.; Urosomoida pseudofurcata (Berger, 1999) comb. nov
Nature helps: From research to products against blood-sucking arthropods
Abstract Today, there is a trend in research to return to plant extracts as remedies against endo-and ectoparasites. Many daily appearing papers describe the efficacy of different plant extracts. However, the second step, to develop a product for the market (that could settle obvious needs), is in general not done. Thus, many results will be forgotten soon and the work was done in vain. The present review shows in examples that very efficacious biocidal and repellent products were developed from extracts of the plants Vitex agnus castus, Azadirachta indica, and from others which produce etheric oils. Of course, it is needed that the extracts have to be tested seriously for their activity, non-toxicity, tolerability, and user compliance. However, the selected examples show that it is worthwhile to consider plants in the fight against endo-and ectoparasites
Taxonomic Studies on Three Marine Ciliates from China, Including a New Species (Ciliophora, Cyrtophorida)
The present work investigates the living morphology and infraciliature of three marine cyrtophorid ciliates, which were isolated from Qingdao, China. Compared with its congeners, Orthotrochilia sinica spec. nov. can be distinguished by a combination of features: body slender and elliptical in outline, size about 50–60 × 20–25 μm in vivo, 18–21 somatic kineties, the length of the left perioral kinety treble the length of the right one, two ventrally located contractile vacuoles on the right side, and 25–32 nematodesmal rods. Based on current observations and the previous description, the diagnosis of Trochilioides tenuis (Deroux, 1976) Chen et al. 2011 is improved: cell size 30–40 × 20–35 μm in vivo, oval shaped in outline; consistently three right kineties, four left kineties and seven postoral kineties; a single contractile vacuole; marine habitat. A second species of Trochilioides, T. recta (Kahl, 1923) Chen et al. 2011 is re-described based on a Chinese population. Furthermore, a key to the identification of species of the genus Trochilioides whose infraciliature data are available is supplied, and Chlamydonyx trivialis (Fenchel, 1965) comb. nov. [basionym: Trochilioides trivialis Fenchel, 1965] is suggested
Guard Cell-Specific Calcium Sensitivity of High Density and Activity SV/TPC1 Channels
The slow vacuolar (SV) channel, a Ca2+-regulated vacuolar cation conductance channel, in Arabidopsis thaliana is encoded by the single-copy gene AtTPC1. Although loss-of-function tpc1 mutants were reported to exhibit a stoma phenotype, knowledge about the underlying guard cell-specific features of SV/TPC1 channels is still lacking. Here we demonstrate that TPC1 transcripts and SV current density in guard cells were much more pronounced than in mesophyll cells. Furthermore, the SV channel in motor cells exhibited a higher cytosolic Ca2+ sensitivity than in mesophyll cells. These distinct features of the guard cell SV channel therefore probably account for the published stomatal phenotype of tpc1-
Evaluation of Procalcitonin Test for Early Diagnosis of Neonatal Sepsis in Tikrit Teaching Hospital
The diagnosis of neonatal infection is challenging because traditional markers of infection are often misleading instead of diagnosing. This study was conducted to determine Procalcitonin (PCT) level as an early marker for diagnosis of suspected sepsis in neonates in comparison with C-reactive protein, blood culture, total and differential white blood cell counts. From August, 2008 till March, 2009, 114 blood samples were collected from neonates (males and females) admitted to the pediatricsneonatal wards at Tikrit Teaching Hospital who were clinically suspected with sepsis as diagnosed by the physician in the hospital with any features suggestive of sepsis. The results of blood culture showed that 53 (46%) of samples were positive, of them 32 (60%) were males and 21 (40%) were females. The number of negative cases were 61 (54%), of them 31 (51%) were females and 30 (49%)were males. The results of identification showed that the most frequent bacterial isolates were Coagulase Negative Staphylococci and Nocardia spp. (22% for each), followed by Listeria monocytogenes 17%, Klebsiella pneumoniae, 9% Pseudomonas aeruginosa 6% and Staphylococcus aureus 6%, while (Citrobacter diversus, Serratia marscesens, Serratia liquifascens, Lactobacillus spp., Peptostreptococcus spp., Micrococcus spp., Streptococcus pyogenes) were frequently less isolated recording 2% for each . The antibiotics susceptibility test revealed that Gram negative isolates showed high resistance to antibiotics used in the present study. Each isolate of the Gram positive bacteria showed different pattern of resistance against the antibiotics used. Results of virulence factor showed that 85%, 100%, 100% , 100% and 62% of Gram negative isolates and 61%, 100% , 89%, 94% and 78% of Gram positive isolated produced Urease , Hemolysin, Lipase, Lecithinase and alkaline protease, respectively. Results of routine hematological tests at which the differences were statistically significant showed that 33% of culture positive cases had leucopenia, 19% of cases had leukocytosis, while the rest were in the category of normal range. For CRP, the differences were not significant among culture positive and culture negative cases. With reference to PCT test which had been measured using the immunochromatographic semi-quantitative method. The results showed that 21% of culture positive cases were with PCT level with high levels distributed among levels of PCT≥0.5 ≥2 ≥10 ng/ml. As for culture negative cases, 49% of PCT were systemic infections cannot be excluded though they were culture negative. In addition PCT results did not fit with CRP all the time since some cases recorded higher level of PCT ≥10 ng/ml despite they were negative for CRP. The comparison between results of PCT and WBC for the same performed cases showed that 68% of cases were in the category of normal WBC range, meanwhile they had high level of PCT. Only 18% were in the category of leukocytosis, and the rest of percentage were in the category of leucopenia. When PCT was compared with other routinely measured parameters used in this study, It seemed to be significantly more sensitive in sepsis diagnosis. Accordingly, we can conclude that PCT is a more sensitive marker than other traditional tests (blood culture, CRP and WBC count) that could be used in early diagnosis of bacterial sepsis in neonate
The Diversity of Scuticociliates (Protozoa, Ciliophora): A Report on Eight Marine Forms Found in Coastal Waters of China, with a Description of One New Species
Eight marine scuticociliates, Pseudoplatynematum denticulatum (Kahl, 1933) nov. comb., Protocyclidium sinica nov. spec., Histiobalantium marinum Kahl, 1933, Porpostoma notata Möbius, 1888, Philaster hiatti Thompson, 1969, Parauronema longum Song, 1995, Uronemella parafilificum Gong et al., 2007, and Paranophrys magna Borror, 1972, collected from Chinese coastal waters, were investigated using live observations and silver impregnation methods. Investigations of a Chinese population of Platynematum denticulatum (Kahl, 1933) reveal that it has a highly strengthened pellicle and distinct spines and thus corresponds well with the definition of Pseudoplatynematum Bock, 1952. A new combination, Pseudoplatynematum denticulatum (Kahl, 1933) nov. comb., is therefore proposed and an improved species diagnosis is supplied. Protocyclidium sinica nov. spec. is characterized by: small body size with buccal field approximately 60% of body length; extrusomes present; 13 or 14 somatic kineties; somatic kinety 1 comprising approximately 24 densely arranged kinetids; somatic kinety n shortened posteriorly; single macronucleus. Additional information is documented on the morphology of six other species of scuticociliates based on the China populations
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