A Comparison of Walking Rates Between Wild and Zoo African Elephants

With increased scrutiny surrounding the welfare of elephants in zoological institutions, it is important to have empirical evidence on their current welfare status. If elephants are not receiving adequate exercise, it could lead to obesity, which can lead to many issues including acyclicity and potentially heart disease. The goal of the current study was to compare the walking rates of elephants in the wild versus elephants in zoos to determine if elephants are walking similar distances relative to their wild counterparts. Eleven wild elephants throughout different habitats and locations in Botswana were compared to 8 elephants at the San Diego Zoo Safari Park. Direct comparisons revealed no significant difference in average walking rates of zoo elephants when compared with wild elephants. These results suggest that elephants at the San Diego Zoo Safari Park walk similar rates to those of wild elephants and may be meeting their exercise needs.     

Protein concentrations have little effect on reabsorption of fluid from isolated rat lungs

A study was conducted to determine whether differences in the concentrations of large molecules between the air space and perfusate solutions altered the rates at which fluid was reabsorbed from isolated fluid-filled perfused rat lungs. Four groups of experiments were conducted: 1) 5 g/dl albumin in the air spaces and perfusate, 2) 15 g/dl albumin in the air space and 5 g/dl albumin in the perfusate, 3) 5 g/dl albumin in the air space and 15 g/dl albumin in the perfusate, and 4) a mixture of 5 g/dl albumin and 7 g/dl Dextran 70 in the air spaces and 5 g/dl albumin in the perfusate. Fluid reabsorption was determined by following the concentration of albumin labeled with Evans blue (T-1824) in the air space and perfusate compartments. Because leakage of protein between the air space and perfusate compartments is very slow, increases in T-1824 concentrations in the air spaces indicated loss of fluid from this compartment, whereas decreases in these concentrations in the perfusate compartment provided evidence of fluid transport into the vasculature. Approximately 30% of the air space fluid was reabsorbed in a 2-h period, and virtually all of this fluid reached the perfusate compartment. Despite oncotic differences that ranged from -65 to 65 Torr, variations in air space or perfusate albumin concentrations did not have a significant effect on this process. A 30% decrease in fluid reabsorption was observed when dextran was in the air space solution, but this decrease did not appear to be due to the oncotic properties of this solution because albumin did not have a measurable effect on reabsorption.(ABSTRACT TRUNCATED AT 250 WORDS)     

Nutrient Leaching and End Product Accumulation in Plastic Composite Supports for L-(+)-Lactic Acid Biofilm Fermentation

Investigations on the leachate bioavailability, leaching rate, and lactic acid accumulation properties of plastic composite supports (PCS) were essential for large-scale or long-term lactic acid fermentation. Leachates from PCS and polypropylene discs (controls) were analyzed by the micro-Kjeldahl method; by absorbances at 260, 275, and 280 nm; and by bioassays with Lactobacillus casei subsp. rhamnosus (ATCC 11443). The amount of leached nitrogen in a 20-ml initial soaking solution had a high correlation with the soaking solution's cell density (r = 0.87) and absorbance at 260 nm (r = 0.95). Leaching rates of various PCS were evaluated by 20 20-ml simulated repeated-batch fermentations (RBF). PCS with only yeast extract as the minor agricultural ingredient had a high leaching rate and leached out 51 to 60% of the total nitrogen during the first RBF. PCS blended with dried bovine albumin, dried bovine erythrocytes, and/or soybean flour had slowed nutrient leaching (20 to 30% of the initial leached nitrogen). Hence, they could still maintain 1 g of lactic acid per liter and measurable cell density (absorbance at 620 nm, 0.4 to 0.6) at the 20th 20-ml RBF. Lactic acid accumulation properties of PCS were evaluated by soaking the supports in a 30% lactic acid solution for 72 h at 45(deg)C. The lactic acid-soaked supports were rinsed three times and then heat treated (121(deg)C, 15 min) in 15 ml of deionized water. The results showed that lactic acid accumulation in PCS was mainly due to absorption and had no correlation with lactic acid production or biofilm formation.     

Leprosy among patient contacts: a multilevel study of risk factors

Background

This study aimed to evaluate the risk factors associated with developing leprosy among the contacts of newly-diagnosed leprosy patients.

Methodology/Principal Findings

A total of 6,158 contacts and 1,201 leprosy patients of the cohort who were diagnosed and treated at the Leprosy Laboratory of Fiocruz from 1987 to 2007 were included. The contact variables analyzed were sex; age; educational and income levels; blood relationship, if any, to the index case; household or non-household relationship; length of time of close association with the index case; receipt of bacillus Calmette-Guérin (BGG) vaccine and presence of BCG scar. Index cases variables included sex, age, educational level, family size, bacillary load, and disability grade. Multilevel logistic regression with random intercept was applied. Among the co-prevalent cases, the leprosy-related variables that remained associated with leprosy included type of household contact, [odds ratio (OR) = 1.33, 95% confidence interval (CI): 1.02, 1.73] and consanguinity with the index case, (OR = 1.89, 95% CI: 1.42–2.51). With respect to the index case variables, the factors associated with leprosy among contacts included up to 4 years of schooling and 4 to 10 years of schooling (OR = 2.72, 95% CI: 1.54–4.79 and 2.40, 95% CI: 1.30–4.42, respectively) and bacillary load, which increased the chance of leprosy among multibacillary contacts for those with a bacillary index of one to three and greater than three (OR = 1.79, 95% CI: 1.19–2.17 and OR: 4.07–95% CI: 2.73, 6.09), respectively. Among incident cases, household exposure was associated with leprosy (OR = 1.96, 95% CI: 1.29–2.98), compared with non-household exposure. Among the index case risk factors, an elevated bacillary load was the only variable associated with leprosy in the contacts.

Conclusions/Significance

Biological and social factors appear to be associated with leprosy among co-prevalent cases, whereas the factors related to the infectious load and proximity with the index case were associated with leprosy that appeared in the incident cases during follow-up.     

The branchial arches and HGF are growth-promoting and chemoattractant for cranial motor axons

During development, cranial motor neurons extend their axons along distinct pathways into the periphery. For example, branchiomotor axons extend dorsally to leave the hindbrain via large dorsal exit points. They then grow in association with sensory ganglia, to their targets, the muscles of the branchial arches. We have investigated the possibility that pathway tissues might secrete diffusible chemorepellents or chemoattractants that guide cranial motor axons, using co-cultures in collagen gels. We found that explants of dorsal neural tube or hindbrain roof plate chemorepelled cranial motor axons, while explants of cranial sensory ganglia were weakly chemoattractive. Explants of branchial arch mesenchyme were strongly growth-promoting and chemoattractive for cranial motor axons. Enhanced and oriented axon outgrowth was also elicited by beads loaded with Hepatocyte Growth Factor (HGF); antibodies to this protein largely blocked the outgrowth and orientation effects of the branchial arch on motor axons. HGF was expressed in the branchial arches, whilst Met, which encodes an HGF receptor, was expressed by subpopulations of cranial motor neurons. Mice with targetted disruptions of HGF or Met showed defects in the navigation of hypoglossal motor axons into the branchial region. Branchial arch tissue may thus act as a target-derived factor that guides motor axons during development. This influence is likely to be mediated partly by Hepatocyte Growth Factor, although a component of branchial arch-mediated growth promotion and chemoattraction was not blocked by anti-HGF antibodies.     

Anti-mRNAs in La Crosse bunyavirus-infected cells.

Unlike some members of the family Bunyaviridae which contain ambisense genomes, all La Crosse virus reading frames are translated from antigenome sense mRNAs. Nevertheless, La Crosse virus genome sense mRNAs or anti-mRNAs are initiated from antigenome templates. These are characterized by the same range of capped, nontemplated sequences at their 5' ends as mRNAs, but their 3' ends are presumed to be heterogenous, as they were not seen on RNA blots. The anti-mRNAs are estimated to be 15 to 30 times less abundant than mRNAs, but remarkably, this ratio is similar to that of functional genome sense mRNAs made from other bona fide ambisense segments. A role for these anti-mRNAs during infection is unclear.     

Eimeria saudiensis N. Sp. (Apicomplexa: Eimeriidae) from the Arabian Oryx (Oryx leucoryx) in Saudi Arabia

Oocysts of Eimeria saudiensis n. sp. (Apicomplexa: Eimeriidae) are described from the feces of the Arabian oryx, Oryx leucoryx , from the Riyadh Zoo, Saudi Arabia. The oocysts were ellipsoidal or slightly ovoid, 31.2 times 24.5 (24.3–36.5 times 20.0–27.6) μm with a bilayered wall about 1.7 μm thick. The micropyle was covered by a dome-shaped cap. The oocyst residuum was absent, but tiny polar granules were present. The sporocysts were elongate ovoid, 14.3 times 7.2 (11.5–18.5 times 6.0–9.0) μm, had a Stieda body, but lacked a substiedal body. The sporocyst residuum was present, composed of numerous small granules. The sporozoites were elongate club-shaped, and contained two prominent refractile bodies.     

Spermine and spermidine mediate protection against oxidative damage caused by hydrogen peroxide

Summary. The polyamines spermidine and spermine have been hypothesized to possess different functions in the protection of DNA from reactive oxygen species. The growth and survival of mouse fibroblasts unable to synthesize spermine were compared to their normal counterparts in their native and polyamine-depleted states in response to oxidative stress. The results of these studies suggest that when present at normal or supraphysiological concentrations, either spermidine or spermine can protect cells from reactive oxygen species. However, when polyamine pools are pharmacologically manipulated to produce cells with low levels of predominately spermine or spermidine, spermine appears to be more effective. Importantly, when cells are depleted of both glutathione and endogenous polyamines, they exhibit increased sensitivity to hydrogen peroxide as compared to glutathione depletion alone, suggesting that polyamines not only play a role in protecting cells from oxidative stress but this role is distinct from that played by glutathione.