The Abdominal Circulatory Pump

Blood in the splanchnic vasculature can be transferred to the extremities. We quantified such blood shifts in normal subjects by measuring trunk volume by optoelectronic plethysmography, simultaneously with changes in body volume by whole body plethysmography during contractions of the diaphragm and abdominal muscles. Trunk volume changes with blood shifts, but body volume does not so that the blood volume shifted between trunk and extremities (Vbs) is the difference between changes in trunk and body volume. This is so because both trunk and body volume change identically with breathing and gas expansion or compression. During tidal breathing Vbs was 50–75 ml with an ejection fraction of 4–6% and an output of 750–1500 ml/min. Step increases in abdominal pressure resulted in rapid emptying presumably from the liver with a time constant of 0.61±0.1SE sec. followed by slower flow from non-hepatic viscera. The filling time constant was 0.57±0.09SE sec. Splanchnic emptying shifted up to 650 ml blood. With emptying, the increased hepatic vein flow increases the blood pressure at its entry into the inferior vena cava (IVC) and abolishes the pressure gradient producing flow between the femoral vein and the IVC inducing blood pooling in the legs. The findings are important for exercise because the larger the Vbs the greater the perfusion of locomotor muscles. During asystolic cardiac arrest we calculate that appropriate timing of abdominal compression could produce an output of 6 L/min. so that the abdominal circulatory pump might act as an auxiliary heart

Anthelmintic activity of Artemisia annua L. extracts in vitro and the effect of an aqueous extract and artemisinin in sheep naturally infected with gastrointestinal nematodes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)There is no effective natural alternative control for gastrointestinal nematodes (GIN) of small ruminants, with Haemonchus contortus being the most economically important GIN. Despite frequent reports of multidrug-resistant GIN, there is no new commercial anthelmintic to substitute failing ones. Although trematocidal activity of artemisinin analogs has been reported in sheep, neither artemisinin nor its plant source (Artemisia annua) has been evaluated for anthelmintic activity in ruminants. This study evaluated the anthelmintic activity of A. annua crude extracts in vitro and compared the most effective extract with artemisinin in sheep naturally infected with H. contortus. A. annua leaves extracted with water, aqueous 0.1 % sodium bicarbonate, dichloromethane, and ethanol were evaluated in vitro by the egg hatch test (EHT) and with the bicarbonate extract only for the larval development test (LDT) using H. contortus. The A. annua water, sodium bicarbonate (SBE), ethanol, and dichloromethane extracts tested in vitro contained 0.3, 0.6, 4.4, and 9.8 % of artemisinin, respectively. The sodium bicarbonate extract resulted in the lowest LC99 in the EHT (1.27 mu g/mL) and in a LC99 of 23.8 mu g/mL in the LDT. Following in vitro results, the SBE (2 g/kg body weight (BW)) and artemisinin (100 mg/kg BW) were evaluated as a single oral dose in naturally infected Santa Ins sheep. Speciation from stool cultures established that 84-91 % of GIN were H. contortus, 8.4-15.6 % were Trichostrongylus sp., and 0.3-0.7 % were Oesophagostomum sp. Packed-cell volume and eggs per gram (EPG) of feces were used to test treatment efficacy. The SBE tested in vivo contained no artemisinin, but had a high antioxidant capacity of 2,295 mu mol of Trolox equivalents/g. Sheep dosed with artemisinin had maximum feces concentrations 24 h after treatment (126.5 mu g/g artemisinin), which sharply decreased at 36 h. By day 15, only levamisole-treated sheep had a significant decrease of 97 % in EPG. Artemisinin-treated and SBE-treated sheep had nonsignificant EPG reductions of 28 and 19 %, respectively, while sheep in infected/untreated group had an average EPG increase of 95 %. Sheep treated with artemisinin and A. annua SBE maintained blood hematocrits throughout the experiment, while untreated/infected controls had a significant reduction in hematocrit. This is the first time oral dose of artemisinin and an aqueous extract of A. annua are evaluated as anthelmintic in sheep. Although oral dose of artemisinin and SBE, at single doses, were ineffective natural anthelmintics, artemisinin analogs with better bioavailability than artemisinin should be tested in vivo, through different routes and in multiple doses. The maintenance of hematocrit provided by artemisinin and A. annua extract and the high antioxidant capacity of the latter suggest that they could be combined with commercial anthelmintics to improve the well-being of infected animals and to evaluate potential synergism.113623452353Brazilian Agricultural Research Corporation (Embrapa)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

NMR spectroscopy for the determination of mucoadhesive properties of polysaccharides

Applications of nuclear magnetic resonance (NMR) spectroscopy to the structural characterization of polysaccharides with mucoadhesive characteristics are described together with some limited cases of uses in the detection of affinity to mucin. Structural characterization spans from quantification of monomeric units of polysaccharides following degradation procedures till to the development of reliable analytical protocols directly on the intact polymeric materials. In these last cases several problems can be solved such as the identification of derivatization sites on monosaccharides units and determination of average length of derivatizing pendants. For non-covalent modifications, the more difficult aspect is the detection of conformational changes. Mucoadhesivity can be determined by exploiting the possibility to detect changes of affinity to mucin of small probe molecules due to the polysaccharide-mucin interaction