Links between blood parasites,blood chemistry,and the survival of nestling American crows

Many studies have used the avian hemosporidians (Leucocytozoon, Plasmodium, and Hemoproteus) to test hypotheses of host–parasite co‐evolution, yet documented health and survival consequences of these blood parasites vary among studies and generalizations about their pathogenicity are debatable. In general, the negative effects of the hemosporidians are likely to be greatest during acute infections of young birds, yet most previous studies in wild passerines have examined chronic effects in adults. Here, we evaluated responses of nestling American crows (Corvus brachyrhynchos) to acute infection (prevalence and burden), as well as its short‐ and long‐term survival consequences. We used panel of nine hematological and biochemical parameters that are regularly used to evaluate the health of domestic animals, including leukocyte profiles, hematocrit, and plasma proteins. We assessed the effects of infection on survival in a mark‐recapture framework. Overall, 56% of crows (n = 321 samples) were infected by at least one of the three genera. Infections by all genera were associated with elevated plasma proteins and globulins, which could indicate an adaptive immune response. However, only Plasmodium infections were associated with low hematocrit (anemia) and lower fledging success, possibly mediated by the negative effect of low hematocrit values on body condition. Moreover, early Plasmodium infection (<40 days of age) had long‐term survival implications: it was associated with lower apparent survival probability within 3 years after fledging. These results suggest that young crows mounted an adaptive immune response to all three genera. Short‐ and long‐term pathological effects, however, were only apparent with Plasmodium infections.     

Pulmonary ventilation, blood gases, and blood pH after training of the arms or the legs.

In two groups of young healthy subjects who performed arm training (N = 5) and leg training (N = 5), respectively, the respiratory adaptation to submaximal exercise with trained and nontrained muscle groups was compared by measurement of the ventilatory equivalent (Ve/Vo2, pH, and blood gases (Pco2, Po2, and So2) in arterial blood and in venous blood from exercising extremities. After training Ve/Vo2 was significantly reduced during exercise with trained muscles, but unchanged during exercise with nontrained muscles. The reduction in Ve/Vo2 was closely related to a less pronounced increase in heart rate and in arterial lactate content, but showed no quantitative correlation to changes in arterial adaptations in trained muscles are mainly responsible for the reduction in Ve/Vo2. After training during exercise with trained as well as nontrained muscles a shift to the right of the blood oxygen dissociation curve occurred as extremities was lower while corresponding Po2 was higher.     

Clinical use of blood,blood components and blood products.

The goal of modern transfusion therapy is to provide appropriate replacement therapy with blood components as opposed to whole blood for patients with specific hematologic deficiencies. A prerequisite of component therapy is, therefore, correct identification of the deficiency. Appropriate use of components avoids many of the hazards associated with the use of whole blood, and at the same time makes maximal use of this valuable resource. Blood components separated from whole blood soon after collection and appropriately stored can, in combination, provide all the factors present in fresh whole blood. Red cell concentrates prepared from multiple packs have a hematocrit of approximately 70%. They may be stored for up to 3 weeks at 4 degrees C and are recommended for most situations requiring red cell transfusions. Platelet concentrates, which can be stored for up to 72 hours at 22 degrees C, may be used for thrombocytopenic patients. Fresh frozen plasma, stored plasma, cryoprecipitated factor VIII, factor VIII concentrate and factor IX complex concentrate are available for the proper treatment of patients with hemorrhagic disorders due to coagulation factor deficiencies. Similarly, albumin and immune serum globulin are available for their oncotic and antibody properties respectively. Thus, the availability and appropriate use of the various blood products allows not only optimal transfusion therapy for each patient, but also fuller utilization of national blood resources.     

Selenium,cadmium, lead,and mercury concentrations in human breast milk,in placenta,maternal blood,and the blood of the newborn

The concentrations of the trace elements Cd, Hg, Pb, and Se during the perinatal period in human placenta and in the blood of the mother and the newborn (cord blood) were determined. Breast milk (colostrum and mature milk) was also included to permit correlations between the different compartments. For Cd, a placental barrier exists, in accord with previous observations. For Pb, a strong correlation between the concentrations in the blood of the mother and of the newborn was found. The concentration of Hg was in most cases below low the detection limit. Its concentration in colostrum was higher than in the mature milk. The results for Se reflect the knowledge about an essential trace element. Strong positive correlations were noted between maternal blood and cord blood and maternal milk. Anodic stripping voltammetry (DPASV) was used for the determination of Cd and Pb, cold vapor AAS (CVAAS) for the determination of Hg, and instrumental neutron activation analysis (INAA) for the determination of Se.     

Mineral- and trace element concentrations in human breast milk,placenta, maternal blood,and the blood of the newborn

The concentrations of the essential trace elements Cu, Fe, and Zn, and of the mineral elements Ca, K, Mg, and P during the perinatal period in human placenta and in the blood of the mother and the newborn (cord blood) were determined. Breast milk (colostrum and transitory milk) was also included to permit correlations between the different compartments. No correlations were found. The uptake by nutrition and the body-pools of the mother and their mobilization for these elements seem to be sufficiently high for an adequate supply of the fetus and the milk in the geographical region of Munich (Bavaria, FRG) under these investigations. Differences in the mineral- and trace element concentrations of colostrum and transitory milk for the elements P and Zn and to a lesser extent for Ca and Mg were observed. Additionally, breast milk samples from different geographical regions in Bavaria were investigated. Results for the heavy metals Cd, Hg, and Pb, and for the essential trace element Se are also presented for these samples, and can be seen as a reflection of the overall environmental and dietary influences during pregnancy in these geographical regions. ICP (Inductively Coupled Plasma)-emission spectrometry was used for the determination of the elements Cu, Fe, Zn, Ca, K, Mg, and P. For the additionally given elements in the milk-samples anodic stripping voltammetry (DPASV) (Cd, Pb), hydride atomic absorption spectrometry (AAS) (Se), and cold vapor AAS (Hg) were applied.     

Evaluation of the hypomagnetic environment effects on capillary blood circulation,blood pressure,and heart rate

The impact of attenuated magnetic field (МF) on human health is a burning issue of present-day cosmonautics. A series of experiments with animals exposed to attenuated MF revealed violent disorders in the development of the cardiovascular system. The purpose of this study was to estimate the effects of hypomagnetic environment (HME) on capillary blood circulation, blood pressure (BP), and heart rate (HR) in healthy humans. Participants (n = 34) were 24 men and 10 women without cardiovascular symptoms. The mean age was 43.3 ± 15.4 years. Thirteen participants, eight men and five women, were randomly selected for a repeated investigation under natural conditions (sham exposure). The mean age in this group was 47.9 ± 18 years. Cardiac rhythm and heart rate were recorded using an Astrocard cardiac monitor (Russia). BP was measured by means of a Tonocard automatic blood pressure monitor (Russia). Capillary circulation was determined using a digital capillaroscope (Russia) with a high-speed CMOS camera (100 frames/s). The duration of HME exposure was 60 min. It has been demonstrated that HME increases capillary circulation rate by 22.4% in healthy humans without cardiovascular symptoms as compared to the records made under natural conditions. There was a significant HR reduction by the end of HME exposure as compared to the measurements taken at the beginning. At the end of the exposure, diastolic BP dropped considerably relative to mid-exposure values; on the contrary, systolic BP significantly increased by the end.     

A survey of the concentrations of eleven metals in vaccines, allergenic extracts, toxoids, blood, blood derivatives and other biological products

Approximately 85 samples of injectable biological products regulated by the Center for Drugs and Biologics of the United States Food and Drug Administration were surveyed for the presence of 11 elements, namely aluminum, arsenic, barium, cadmium, chromium, lead, mercury, selenium, thallium and zinc, by flame and flameless methods of atomic absorption spectrometry and flame emission spectrometry. The range of products tested included whole blood, red cells, plasma, normal serum albumin, antihemophilic factor, and other products derived from blood; allergenic extracts including honey bee venom and house dust allergenic extracts; vaccines such as measles virus vaccine and typhoid vaccine; and tetanus toxoid. The metal concentrations found in the majority of these products were low or undetectable. The metal levels varied from manufacturer to manufacturer, product and lot-to-lot of the same manufacturer's products. House dust allergenic extracts had the highest concentrations of arsenic (2.4 ppm), cadmium (0.28 ppm), chromium (0.6 ppm) and lead (1.5 ppm) found in the study. A high zinc concentration (24 ppm) in an immune serum globulin was attributed to the zinc-containing rubber stopper in contact with the product. A range of 0.36-3.30 ppm aluminum was found for seven 25% normal serum albumin samples from seven manufacturers. Values of 8.2, 17 and 18 ppm aluminum were found in one manufacturer's 25% normal serum albumin. These aluminum values appeared to be the result of an anomaly in this manufacturer's production that has not been repeated to date.     

The effects of prolonged ketamine-xylazine intravenous infusion on arterial blood pH, blood gases, mean arterial blood pressure, heart and respiratory rates, rectal temperature and reflexes in the rabbit

The prolonged and safe maintenance of general anesthesia in rabbits with commonly used injectable agents is difficult. Protracted, stable anesthesia with short recovery time has been described in humans using continuous intravenous infusion of ketamine with or without sedatives, muscle relaxants and paralytics. This study evaluated the anesthetic plane achieved and respiratory and cardiovascular effects produced with a ketamine-xylazine intravenous infusion in New Zealand White rabbits. Ten female rabbits were anesthetized with intramuscularly administered ketamine hydrochloride (35 mg/kg) and xylazine hydrochloride (5 mg/kg) after the preanesthetic, baseline measurements of arterial blood pO2, pCO2 and pH and heart and respiratory rates were recorded. The above parameters as well as mean arterial blood pressure, righting, palpebral, pedal, and jaw reflexes were monitored ten minutes after the intramuscularly administered dosage and throughout 4 hours of infusion. Results showed moderate hypotension (21.2% deviation from normal, p less than 0.008) and profound hypoxemia (45% deviation from baseline, p less than 0.001) 10 minutes after the intramuscularly administered induction dosage. Then, the 4 hour infusion of ketamine (1 mg/minute) and xylazine (0.1 mg/minute) was started. Hypotension progressed (49.1% deviation from normal, p less than 0.008), but hypoxemia and hypercarbemia gradually improved with no resultant change (p greater than 0.1) in arterial pH. There was no significant change (p greater than 0.1) in respiratory rate but varying qualities of respiration were observed. Both mean arterial pO2 and pCO2 values returned to baseline within 20 minutes after completion of infusion. Heart rate and rectal temperature remained stable during the trial. The righting reflex was abolished in all rabbits throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)     

Does the Anopheles blood meal-fecundity curve, curve?

We determined the blood meal size-fecundity relationship in Anopheles gambiae in the laboratory. Our primary interest was to determine whether the fecundity curve has a non-linear component, i.e.. does it decelerate towards an asymptote? Small and large adult females in their second gonotrophic cycle were fed on human hosts for predetermined lengths of time. Blood meal size was ascertained by weight and subsequent fecundity was determined by the number of eggs laid on filter paper. In both small and large-bodied females there was a significant curvilinear component. We used this relationship to show that marginal returns from feeding decline as a function of current blood load. This means that further fecundity payoff for continued feeding declines over time.