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Zoonoses are a worldwide public health concern, accounting for approximately 75% of human infectious diseases. In addition, zoonoses adversely affect agricultural production and wildlife. We review some mathematical models developed for the study of viral zoonoses in wildlife and identify areas where further modeling efforts are needed. [ABSTRACT FROM AUTHOR]

Antibodies are a core element of the immune system's defense against infectious diseases. We hypothesize that antibody titres might therefore be an important predictor of survival in older individuals. This is important because biomarkers that robustly measure survival have proved elusive, despite their potential utility in health care settings. We present evidence supporting the hypothesis that influenza antibody titres are associated with overall survival of older individuals, and indicate a role for biological sex in modulating this association. Since antibody titres can be modulated by vaccination, these results have important implications for public health policy on influenza control in aging populations., Competing Interests: Conflict of interest: none

Lipid accumulation is associated with reduced embryonic quality, causing limited survival after cryopreservation. Therefore, in the present study we aimed to reveal the effects of supplementation of a lipid reducing agent, l-carnitine and the removal of fatty acids during in vitro culture on the morphological as well as on the molecular level. To accomplish that, presumptive zygotes were cultured in 4 contrasting groups: namely SOFaa medium supplemented with BSA, (BSA), SOFaa medium supplemented with fatty acid free BSA (FAF), SOFaa medium supplemented with BSA as well as l-Carnitine (BSA + LC) and SOFaa medium concurrently supplemented with fatty acid free BSA and l-Carnitine (FAF + LC). Considering the developmental rates, no impact of different treatments was observed. Conversely, treatment groups clearly affected lipid content, with the lowest amounts detected in embryos derived from FAF and BSA + LC groups, implicating that both removal of fatty acids and supplementation of LC reduces lipid content effectively. Importantly, survival rates after cryopreservation show that LC significantly affects the kinetics of re-expansion, with the highest hatching rates detected for embryos cultured in FAF + LC (p < 0.05). Noteworthy, the highest cryotolerance did not go along with lowest lipid contents. Finally, metabolic alterations between the groups were reflected in different abundances of selected candidate genes related to lipid metabolism and oxidative stress response, like AMPKA1, ACC and PGC1 α or KEAP1 and SOD1. All in all, highly beneficial effects on survival rates after cryopreservation have been detected when embryos were cultured in absence of fatty acids and concurrent presence of l-Carnitine. Highest cryotolerance, however, did not correlate with lowest lipid contents., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Field studies of hantavirus infection in rodents report that a higher percentage of infected individuals are males than females. To determine whether males were more susceptible to hantavirus infection than females, adult male and female Long Evans rats (Rattus norvegicus) were inoculated with doses of Seoul virus ranging from 10(-4) to 10(6) PFU. The 50% infective doses (ID(50)) were not significantly different for male and female rats (10(0.05) and 10(0.8) PFU, respectively). To determine whether sex differences in response to infection were related to circulating sex steroid hormones, sex steroid concentrations were manipulated and antibody responses and virus shedding were assessed following inoculation with the ID(90). Regardless of hormone treatment, males had higher anti-Seoul virus immunoglobulin G (IgG) and IgG2a (i.e., Th1) responses than females and IgG1 (i.e., Th2) responses similar to those of females. Males also shed virus in saliva and feces longer than females. Manipulation of sex steroids in adulthood did not alter immune responses or virus shedding, suggesting that sex steroids may organize adult responses to hantavirus earlier during ontogeny.

The seasonal effects of photoperiod on reproduction are mediated by melatonin, and it is hypothesized that increased immune function in short days is due to the increase in the duration of nightly melatonin secretion. Melatonin can act both directly and indirectly on target tissue within the immune system. The present study sought to tease apart the direct and indirect effects of melatonin on one aspect of immune function by examining the influence of in vitro melatonin on splenocyte proliferation in female prairie voles held in long (LD 16:8) or short (LD 8:16) days. Splenocyte proliferation in response to the T-cell mitogen concanavalin A was enhanced by the addition of melatonin in vitro, as compared to cultures receiving no melatonin. Body mass increased in short-day housed prairie voles, indicating that the animals were responsive to photoperiod. However, photoperiod did not affect splenocyte proliferation in the present study. These results support the hypothesis that melatonin exerts a direct effect on splenocyte proliferation, potentially via high-affinity melatonin receptors localized on splenocytes. The findings also indicate that, irrespective of photoperiod, melatonin exerts direct effects on splenocytes to enhance immune function.

Exposure to proinflammatory cytokines (e.g., IL-1beta) or lipopolysaccharide (LPS) produces an acute activation of the immune response and results in a repertoire of behavioral patterns collectively termed sickness behaviors. Although nonspecific responses to pathogenic infection have traditionally been viewed as maladaptive effects of infection, sickness behaviors may have significant, adaptive value for the host. One set of adaptive behaviors affected by infection among mammals and birds is mate choice. In Experiment 1, female prairie voles exhibited the expected increase in blood corticosterone concentrations in response to a 0.1 cc i.p. LPS injection (50 microg), indicating activation of the endocrine system. A separate cohort of females was injected with LPS or saline and paired for 6 h with a novel, previously unpaired male. Following the cohabitation period, LPS-injected females spent significantly more time (p < 0.05) with the familiar partner when given a choice between familiar and unfamiliar males in a three-chamber apparatus designed to test partner preferences. Saline-injected females spent significantly more time with the unfamiliar male. In Experiment 2, males injected with LPS or saline spent equal amounts of time with familiar and unfamiliar females following a 6 h cohabitation with a naive female, and therefore, did not exhibit preferences. From a proximate perspective, this study provides evidence that sickness behaviors influence female, but not male, partner preference in prairie voles.

Males are generally more susceptible to parasite infection than females. This sex difference may reflect the suppressive effects of testosterone and enhancing effects of estradiol on immune function. This study characterized the role of circulating steroid hormones in sex differences after infection with the nematode Trichinella spiralis. Because testosterone suppresses immune function and because polygynous males have higher circulating testosterone concentrations than monogamous males, sex differences in parasite burden were hypothesized to be exaggerated among polygynous meadow voles compared with monogamous prairie voles. As predicted, sex differences in response to T. spiralis infection were increased among meadow voles; males had higher worm numbers than females. Male and female prairie voles had equivalent parasite burden. Overall, prairie voles had higher worm numbers than meadow voles. Contrary to our initial prediction, differences in circulating estradiol concentrations in females, testosterone concentrations in males, and corticosterone concentrations in both sexes were not related to the observed variation in T. spiralis infection. Taken together, these data suggest that not all sex differences in parasite infection are mediated by circulating steroid hormones and that adaptive-functional explanations may provide new insight into the causes of variation in parasite infection.

Nitric oxide (NO) acts as a neuronal messenger in both the central and peripheral nervous systems and has been implicated in reproductive physiology and behavior. Pharmacological inhibition of nitric oxide synthase (NOS) with the nonspecific NOS inhibitor, l-N(G)-nitro-Arg-methyl ester (l-NAME), induced deficits in both the number of ovarian rupture sites and the number of oocytes recovered in the oviducts of mice. Female neuronal NOS knockout (nNOS-/-) mice have normal numbers of rupture sites, but reduced numbers of oocytes recovered following systemic injections of gonadotropins, suggesting that NO produced by nNOS accounts, in part, for deficits in ovulatory efficiency observed after l-NAME administration. Additionally, endothelial NOS knockout (eNOS-/-) mice have reduced numbers of ovulated oocytes after superovulation. Because endothelial NOS has been identified in ovarian follicles, and because of the noted reduced breeding efficiency of eNOS-/- mice, the present study sought to determine the role of NO from eNOS in mediating the number of rupture sites present after ovulation. Estrous cycle length and variability were consistently reduced in eNOS-/- females. The number of rupture sites was normal in eNOS-/- mice under natural conditions and after administration of exogenous GnRH. After exogenous gonadotropin administration, eNOS-/- females displayed a significant reduction in the number of ovarian rupture sites. Female eNOS-/- mice also produced fewer pups/litter compared to WT mice. These data suggest that NO from endothelial sources might play a role in mediating rodent ovulation and may be involved in regulation of the timing of the estrous cycle., (Copyright 1999 Academic Press.)

In Experiment 1, individually housed male meadow voles (Microtus pennsylvanicus) and prairie voles (Microtus ochrogaster) were injected with lipopolysaccharide (LPS) and exhibited the expected decrease in testosterone and increase in corticosterone and interleukin-1beta concentrations 3 hr later, indicating activation of the endocrine and immune systems. In Experiment 2, LPS- and saline-injected males were tethered in a 3-chamber partner preference apparatus. The time females spent in each chamber with a male, as well as the amount of time spent in social contact, was monitored. Female prairie voles, but not meadow voles, spent more time in the chamber with saline- than with LPS-injected males. LPS-injected male prairie and meadow voles engaged in less social contact with female conspecifics than did saline-injected males. These data suggest that LPS modifies physiology and behavior in male voles and that females may use these changes to discriminate healthy from potentially infected males.

Animals are presented with continuous energy demands that vary seasonally. For example, during the winter many small mammals and birds inhibit reproduction and growth and funnel energy into thermogenesis or cellular maintenance. As energy shortages become more severe, survival may become compromised because processes such as immune function and thermogenesis are impaired. Thus, there are trade-offs between energetically expensive processes such as reproduction and immune function. In this review, the immune function and reproduction of seasonally breeding species are evaluated in relation to social interactions. It is proposed that individuals maintain the highest degree of immune function that is energetically possible within the constraints of other survival needs, as well as growth and reproduction, in habitats in which energy requirements and availability often fluctuate. It is hypothesized that extrinsic factors, such as social environment, modulate energy allocation to reproductive and immune function and that hormonal mechanisms underlie the partitioning of energy to various physiological components.

Background: Nitric oxide (NO) plays an important role in numerous reproductive processes. To date, most studies have assessed the role of NO by using nonspecific pharmacological inhibitors of the precursor to NO, nitric oxide synthase (NOS). These pharmacological NOS inhibitors suppress all isoforms of NOS; thus, the precise contribution of each isoform to female reproductive physiology is unknown. The purpose of this study was to determine the specific role of neuronal NOS (nNOS) in the regulation of ovulation in female mice lacking the gene that encodes for nNOS (nNOS-/-)., Materials and Methods: Ovulation was assessed in wild-type (WT) and nNOS-/- female mice by examining the number of ovarian rupture sites and number of oocytes recovered from the oviducts following mating or exposure to exogenous gonadotropins (i.e., 5 IU pregnant mares serum gonadotropin [PMSG] and 5 IU human chorionic gonadotropin [hCG]). Ovulatory efficiency was determined as the number of ovulated oocytes per number of ovarian rupture sites. To examine whether ovulatory deficits in nNOS-/- mice were due to alternations in central mechanisms, plasma luteinizing hormone (LH) concentrations were assessed in WT and nNOS-/- mice that were challenged with 25 ng of gonadotropin-releasing hormone (GnRH). To determine whether ovulatory deficits in nNOS-/- mice were due to local ovulation processes, nerves innervating the reproductive tract of WT and nNOS-/- females were examined for the presence of nNOS protein., Results: There were substantial fertility deficits in nNOS-/- female mice; the nNOS-/- mice had fewer oocytes in their oviducts following spontaneous and gonadotropin-stimulated ovulation. Pituitary responsiveness to exogenous GnRH challenge was intact in nNOS-/- mice. Dense nNOS protein staining was observed in nerves innervating the reproductive tracts of WT mice., Conclusions: The reproductive deficits in nNOS-/- females are most likely due to alternations in the transfer of oocytes from the ovaries to the oviducts during ovulation. These results suggest that defects in neuronally derived NO production may contribute to female infertility.

Males generally exhibit reduced immune responses and greater susceptibility to disease than females. The suppressive effect of testosterone on immune function is hypothesized to be one reason why males have lower immune responses than females. Presumably, this effect of testosterone should be more pronounced among polygynous than monogamous species because circulating testosterone is higher among polygynous than monogamous males. The present study examined the extent to which sex differences in specific humoral immunity are related to the endocrine status and mating system of two arvicoline rodents. Humoral immunity was evaluated among polygynous meadow voles (Microtus pennsylvanicus) and monogamous prairie voles (Microtus ochrogaster) by challenging them with the novel antigen keyhole limpet hemocyanin (KLH) and assessing specific immune responses 5, 10, and 15 d following immunization. Overall, meadow voles mounted higher anti-KLH IgM and IgG responses than prairie voles did. Sex differences were also apparent for anti-KLH IgM responses; male meadow voles mounted higher antibody responses than conspecific females, whereas female prairie voles mounted greater responses to KLH than did conspecific males. Male meadow voles had significantly higher testosterone concentrations and reproductive organ mass than male prairie voles did but had elevated immune responses, suggesting that testosterone may not be the primary factor involved in the observed sex and species differences in immune responses. Species and sex differences in corticosterone concentrations were also evident and may contribute to the observed differences in immune function. The influence of extrinsic factors on immune function is also discussed. Taken together, these data provide evidence that the mating system may influence endocrine-immune interactions.

Nitric oxide (NO) is well established as a neurotransmitter in the central and peripheral nervous systems. More recently, another gas, carbon monoxide (CO) has also been implicated in neurotransmission. In the nervous system CO is formed by a subtype of heme oxygenase (HO) designated HO2. HO2 is localized to discrete neuronal populations in the brain resembling localizations of soluble guanylyl cyclase, which is activated by CO. CO may also function in the peripheral autonomic nervous system, in conjunction with NO. The majority of ganglia in the myenteric plexus possess both HO2 and neuronal NO synthase (NOS). Defects in myenteric plexus neurotransmission occur both in mice with targeted deletion of genes for HO2 and neuronal NOS. HO2 also occurs in other autonomic ganglia including the petrosal, superior cervical and nodose ganglia. Neuronal NOS is localized to neurons regulating male reproductive behavior, such as penile erection, and NOS inhibitors prevent erection. Because of the other parallels between NO and CO, we speculated that CO may play a role in male reproductive behavior. In the present study we describe HO2 localization in neuronal structures regulating copulatory reflexes. Reflex activity of the bulbospongiosus muscle, which mediates ejaculation and ejaculatory behavior, is markedly diminished in mice with targeted deletion of the gene for HO2 (HO2-).

A new in vivo test for burst strength of arterial anastomoses was tested in 40 rats. Twelve had a severed right femoral artery reanastomosed by the traditional nine-suture technique. In a second group of 12, a modified telescoping sleeve method of reanastomosis was used. In a third group of 12, a laser-assisted anastomosis using four stay sutures was performed. Four rats had sham procedures. Immediately after reanastomosis three vessels from each group plus all four sham surgical vessels were subjected to burst testing. These tests were performed again on the repaired vessels at 1 week, 1 month, and 2 months. All the vessels were patent at burst testing. All repairs held at all times to greater than 160 mm mean arterial pressure. The four-suture telescopic anastomosis technique was consistently strongest over time, but all techniques showed adequate strength at all time intervals.