Overt Morbidity Research Articles

Experimental infection of Egyptian rousette bats (Rousettus aegyptiacus) with Sosuga virus demonstrates potential transmission routes for a bat-borne human pathogenic paramyxovirus

In August 2012, a wildlife biologist became severely ill after becoming infected with a novel paramyxovirus, termed Sosuga virus. In the weeks prior to illness, the patient worked with multiple species of bats in South Sudan and Uganda, including Egyptian rousette bats (ERBs: Rousettus aegyptiacus). A follow-up study of Ugandan bats found multiple wild-caught ERBs to test positive for SOSV in liver and spleen. To determine the competency of these bats to act as a natural reservoir host for SOSV capable of infecting humans, captive-bred ERBs were inoculated with a recombinant SOSV, representative of the patient’s virus sequence. The bats were inoculated subcutaneously, sampled daily (blood, urine, fecal, oral and rectal swabs) and serially euthanized at predetermined time points. All inoculated bats became infected with SOSV in multiple tissues and blood, urine, oral, rectal and fecal swabs tested positive for SOSV RNA. No evidence of overt morbidity or mortality were observed in infected ERBs, although histopathological examination showed subclinical disease in a subset of tissues. Importantly, SOSV was isolated from oral/rectal swabs, urine and feces, demonstrating shedding of infectious virus concomitant with systemic infection. All bats euthanized at 21 days post-inoculation (DPI) seroconverted to SOSV between 16 and 21 DPI. These results are consistent with ERBs being competent reservoir hosts for SOSV with spillover potential to humans.

Fine-needle aspiration of goiter (benign and non-neoplastic) with thyroid function abnormalities

Introduction: Thyroid nodule is the prime indication for FNA, which is also a cheap and effective investigation. The current study seeks an association between benign goiter and aberrant thyroid function tests (TFTs). Can thyroid FNA anticipate overt morbidity resulting from thyroid function abnormalities? Materials and Methods: FNA records of 173 patients were studied along with the TFT results. A slide review was undertaken where the FNA impression did not correspond to the TFT. Results: The female:male ratio was 149:24. Two (1.15%) had inadequate cellularity. Nearly 95/173 cases had abnormal TFTs. Multinodular goiter (126), Hashimoto's thyroiditis (43), and two and one cases of granulomatous and unclassified thyroiditis, respectively, constituted our diagnostic profile. Abnormalities in TFT did not correlate with age group, gender, or FNA diagnoses. However, hypothyroidism (clinical and subclinical) was significantly observed in Hashimoto's thyroiditis (HT) cases. Further, scant colloid and hurthle cell change were significantly correlated with HT. A histological correlation was obtained in 46 cases. Four neoplastic cases among which three papillary carcinomas arising in small focal areas within cysts were seen. Conclusions: The major observation in this study is the subset of euthyroid and subclinically hypothyroid cases (23/43, 53.48%) of Hashimoto's thyroiditis (P = 0.0021). If treated with thyroxine replacement, overt hypothyroidism, particularly in pregnant women who are at risk of developing antithyroid antibodies, may be prevented. Besides, the inadequacy rate (1.15%) in the current study is low. False negatives 3/46 (6.5%), though available on a meager and selected subset of the patient population is still within the range of published data.

Abstract 3854: Preclinical characterization of a novel non-cyclic dinucleotide small molecule STING agonist with potent antitumor activity in mice

Abstract The cGAS-STING pathway plays a pivotal role in sensing aberrant cytoplasmic DNA fragments derived from pathogens or host tumor cells and initiating an innate immune response. STING activation induces type I IFNs and a cascade of other pro-inflammatory cytokines that activate the innate immune system and subsequently recruit adaptive immune cells. STING functions as a key mediator bridging the innate and adaptive immune responses by stimulating anti-tumor antigen presentation and promoting effective T cell priming, thereby making STING activation an attractive target for cancer immunotherapy. Currently, all known STING agonists in clinical trials are based on a cyclic dinucleotide (CDN) scaffold. These molecules mimic the endogenous STING ligand cGAMP which displays limited potency and cell permeability. Here we present the preclinical characterization of a novel non-CDN small molecule STING agonist, TTI-10001. TTI-10001 exhibited potent and broad activity in a panel of HEK293T-STING reporter cell lines expressing each of the five human STING (hSTING) alleles or murine STING (mSTING). Activation of the STING pathway was confirmed by an increase of both phospho-STING and phospho-IRF3 after TTI-10001 treatment, and TTI-10001-dependent induction of reporter activity was ablated in the presence of an inhibitor of the downstream STING signaling kinase TBK1. TTI-10001 showed a favorable safety profile with no activity on hERG or major CYP450 isoforms and was well tolerated in mice with no weight loss or overt morbidity after repeat intratumoral administration. Mice dosed with TTI-10001 displayed increased levels of phospho-STING and phospho-IRF3 in tumors as well as elevated expression of various pro-inflammatory cytokines including IFNβ, TNFα, and IL-6. This in vivo activation of STING signaling correlated with significant anti-tumor activity in multiple syngeneic mouse tumor models. In summary, we have generated a novel non-CDN small molecule STING agonist with potent activity on the five hSTING alleles and mSTING. Our compound exhibits strong in vitro and in vivo induction of the STING pathway as well as potent anti-tumor activity. Taken together, these results highlight the potential of TTI-10001 and support further evaluation and development of this molecule as a novel cancer immunotherapy agent. Citation Format: Zezhou Wang, Peter Dove, David Rosa, Bolette Bossen, Simone Helke, Marilyse Charbonneau, Laura Brinen, Karen Dodge, Gloria H. Lin, Carole Galligan, Natasja N. Viller, Mark Wong, Vivian Lee, Tina Catalano, Robert A. Uger, Malik Slassi, Jeff Winston. Preclinical characterization of a novel non-cyclic dinucleotide small molecule STING agonist with potent antitumor activity in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3854.

Overview of Developmental Heart Defects by Dioxins, PCBs, and Pesticides

The developing cardiovascular system is a sensitive target of many environmental pollutants, including dioxins, dioxin-like polychlorinated biphenyls (PCBs), and some pesticides such as methyl parathion. Laboratory research has utilized a variety of vertebrate models to elucidate potential mechanisms that mediate this cardioteratogenicity and to establish the sensitivity of different species for predicting potential risk to environmental and human health. Studies of dioxin and dioxin-like PCBs have illustrated that piscine, avian, and mammalian embryos exhibit cardiovascular structural changes and functional deficits, although the specific characteristics vary among the individual models. Piscine models typically exhibit reduced blood flow, altered heart looping, and reduced heart size and contraction rate. The chick embryo exhibits extensive cardiac dilation, thinner ventricle walls, and reduced responsiveness to chronotropic stimuli, while the murine embryo exhibits reduced heart size. It is notable that in all models the dioxin-associated cardioteratogenicity is associated with increases in cardiovascular apoptosis and decreases in cardiocyte proliferation. While the cardiotertogenicity in piscine and avian species is associated with overt morbidity and mortality, that is not the case for the murine embryo. However, murine offspring exposed during development to dioxin exhibit cardiac hypertrophy and an increased sensitivity to a second cardiovascular insult in adulthood. Thus, although the mammalian embryo is less sensitive to cardiovascular defects by dioxin and dioxin-like compounds, developmental exposure increases the risk of cardiovascular disease later in life. The impact of developmental exposure to dioxin-like chemicals on human cardiovascular disease susceptibility is not known. However, recent animal research has confirmed human epidemiology studies that dioxin exposure in adulthood is associated with hypertension and cardiovascular disease.

Initiating delivery room stabilization/resuscitation in very low birth weight (VLBW) infants with an FiO2 less than 100% is feasible

Background:Oxygen exposure during delivery room (DR) resuscitation, even when brief, is potentially toxic. A practice plan (PP) was introduced for very low birth weight (VLBW) infants ⩽1500 g as follows: initial FiO2 from 0.21 to 1.0 using blenders, oxygen guided by oximetry to maintain saturation between 85% to 95% from birth.Objective:To determine whether the initiating FiO2 could be safely lowered, and by doing so whether the number of infants with a PaO2 >80 mm Hg could be minimized on admission, as well as lowering oxygen requirement at 24 h.Methods:In all, 53 infants admitted between June 2006 and June 2007 were evaluated and compared with 47 infants from 2004 managed with 100 % oxygen (historical comparison group (HC)).Result:Stabilization/Resuscitation included intubation (n=28) and continuous positive airway pressure (CPAP) (n=25); no cardiopulmonary resuscitation (CPR). The heart rate increased rapidly in all cases. The initiating FiO2 decreased from 0.42 to 0.28 over 12 months (P=0.00005); 14 (26%) were resuscitated with room air. Correspondingly, the pH increased from 7.24 to 7.30 (P=0.002) and PCO2 decreased from 53 to 41 (P=0.001). A comparison of infants during the PP with the HC revealed that 36/53 versus 21/47 had an initial PaO2 <80 mm Hg (P=0.02); the median PaO2, that is, 64 versus 86 and saturation, that is, 95% versus 99% on admission were significantly lower. The median FiO2 at 24 h was 0.25 versus 0.40.Conclusion:DR resuscitation of VLBW infants can be initiated with less oxygen even with room air without concomitant overt morbidity. This change was associated with more infants with an initial PaO2 <80 mm Hg and lower saturation values on admission as well as a lower FiO2 requirement at 24 h.

Schistosoma mansoni secretes a chemokine binding protein with antiinflammatory activity

The coevolution of humans and infectious agents has exerted selective pressure on the immune system to control potentially lethal infections. Correspondingly, pathogens have evolved with various strategies to modulate and circumvent the host's innate and adaptive immune response. Schistosoma species are helminth parasites with genes that have been selected to modulate the host to tolerate chronic worm infections, often for decades, without overt morbidity. The modulation of immunity by schistosomes has been shown to prevent a range of immune-mediated diseases, including allergies and autoimmunity. Individual immune-modulating schistosome molecules have, therefore, therapeutic potential as selective manipulators of the immune system to prevent unrelated diseases. Here we show that S. mansoni eggs secrete a protein into host tissues that binds certain chemokines and inhibits their interaction with host chemokine receptors and their biological activity. The purified recombinant S. mansoni chemokine binding protein (smCKBP) suppressed inflammation in several disease models. smCKBP is unrelated to host proteins and is the first described chemokine binding protein encoded by a pathogenic human parasite and may have potential as an antiinflammatory agent.

Jugular vein catheterization for repeated blood sampling in the unrestrained conscious rat

The ability to obtain repeated, low-stress blood samples from adult rats enables the design of complex experiments in which time course information or evaluation of repeated treatments is necessary. Furthermore, it reduces the number of animals necessary to acquire such information and, thus, facilitates compliance with the animal use 3Rs (reduction, refinement and replacement). To this end, a microsurgical technique to collect blood samples from the right atrium through a catheter (cannula) implanted into the right external jugular vein of adult rats is described. Rats tolerate this simple and efficient vascular access technique as evidenced by the absence of overt morbidity or abnormal behaviors. Blood is easily sampled while the rats reside in their home cages. Because the sample volume is replaced, repeated sampling is possible without compromising blood volume. Successful adoption of this procedure by other investigators will be aided by the photographic illustrations accompanying this detailed description of the procedure. Application of this technique to monitor temporal changes in plasma stress hormones during stressor paradigms as well as after behavioral and pharmacological challenges is discussed.

Symphysis-fundal height growth chart of an obstetric cohort of 817 Mozambican women with ultrasound-dated singleton pregnancies.

Our aim was to construct a new symphysis-fundus height (SFH) growth chart, based on Mozambican women with ultrasound-dated singleton pregnancy, who represent the largest obstetric cohort in a developing country followed for this purpose. Two antenatal clinics were chosen in the suburban area of Maputo City. A cohort of 904 consecutively recruited antenatal clients was followed until delivery. The growth of the SFH was measured every second to third week. Gestational age was determined by ultrasound at enrolment. Women with multiple pregnancy or with gestational age > 21 weeks at enrolment were excluded. The average number of antenatal SFH measurements per woman was 7.8 (SD 2.4). The drop out rate was 9.6%. Mean birthweight was 2909 g. Pre-term deliveries occurred in 15% and low birthweight deliveries (< 2500 g) in 16%. Using proper longitudinal methods, we constructed an FH growth chart and compared it with various previously published SFH charts, which showed the Mozambican chart to be 0-3 cm below the others. Nulliparous women were 0.5 cm below multiparous women. We did not find any difference in the SFH growth charts between women with or without overt morbidity. Women with a body mass index (BMI) < 19 and women with a BMI > 27 had approximately 1 cm lower and 1 cm higher readings, respectively, than women with normal BMI. The Mozambican SFH growth chart is an example of an elaborated growth chart for a well-defined population in a low-income country. It constitutes the basis for further studies to predict the small-for-gestational age newborn from anthropometrical data obtained by use of appropriate technology.

Cardiorespiratory status after treatment for acute lymphoblastic leukemia.

The use of certain chemotherapeutic agents is associated with dose-related cardiotoxicity and, potentially, with restrictive lung disease. Therefore, we assessed the cardiopulmonary status and exercise capacity of 19 patients (pts; 9M:10F) 1.1 to 7.1 years (mean 4.6 +/- 1.5 years) after successful treatment of acute lymphoblastic leukemia (ALL) with Dana Farber Cancer Institute protocols. As body mass and nutritional status may influence exercise capacity, we also evaluated their anthropometric status and the plasma levels of rapid turnover proteins. Seven pts designated as "standard risk for relapse" (SR) had received low cumulative doses of doxorubicin (50 +/- 21 mg/m2), while twelve pts at "high or very high risk for relapse" (HR/VHR) had received higher doses (349 +/- 16 mg/m2). The evaluations included a questionnaire, anthropometric assessments, echocardiography, pulmonary function studies, exercise testing, and nutritional assays. Patients' data were compared with published normative data or with control values from our laboratories. In addition, we compared SR pt data with HR/VHR pt data. No pt had overt symptoms or signs of cardiorespiratory compromise. The pts had a higher percent of body fat than age-matched healthy controls (29.7 +/- 7.9% vs. 20 +/- 6%; P < 0.001). On echocardiography, cardiac systolic function was within normal limits in all. However, HR/VHR pts had lower left ventricular (LV) shortening fractions than SR pts (P < 0.05). LV filling velocity, indicative of diastolic function (the E/A ratio), was normal in most pts. Pulmonary function studies were normal. Exercise capacity was below predicted in most cases but heart rates at peak exercise and leg muscle function were within normal limits, suggesting a deconditioned state. Plasma levels of rapid turnover proteins were also normal. Despite lack of overt morbidity in our pt population, subtle abnormalities persist in cardiac function while pulmonary function is normal. Longitudinal studies will identify if further abnormalities or overt morbidity develop. In later years, continuing obesity and a sedentary state may contribute to clinically relevant heart disease.

Microbial Infections in a Declining Wild Turkey Population in Texas

A survey was conducted at 5 locations in Texas for avian pathogens that might adversely affect wild turkey (Meleagris gallopavo) productivity and survival. At 1 site, the Rob and Bessie Welder Wildlife Refuge (WWR), turkeys have declined precipitously in recent years. During the winters of 1983-85, 442 wild turkeys were caught with cannon and drop nets, 161 of these on WWR. Blood samples were drawn for serologic evaluation, and cloacal and tracheal swabs were collected for isolation attempts. Salmonella spp. bacteria, Newcastle disease virus (NDV), and avian influenza virus (AIV) were not detected in any samples tested. Serologic tests for antibodies to NDV and AIV also were negative. Many mycoplasma isolates were recovered from turkeys from every location. Characterization of these isolates indicated that several species were present. None were species typically associated with mycoplasmosis in domestic turkeys, such as Mycoplasma gallisepticum (MG), M. meleagridis (MM), or M. synoviae (MS), although antibodies to these pathogens were detected in turkeys at every location sampled. There was no evidence to link any of these disease causing agents to the decline observed in the population of wild turkeys on the WWR. J. WILDL. MANAGE. 51(4):778-782 The wild turkey population at the WWR has declined significantly since the 1960's. Watts (1968) reported that 700 turkeys occupied the 3,120-ha refuge during the winters of 1965-66 and 1966-67, but by 1970, numbers had declined to about 350 (Smith 1977), and in 1972 to 115. No extensive mortality or overt morbidity was recognized. Yet, according to Smith (1977), poult:hen ratios dropped from 1.4:1 in 1965 to 0.1:1 in 1972. Few turkey broods have been observed on the refuge in recent years (Ransom 1984). Disease has been one of the many factors considered as the possible cause of the decline. Several pathogens of domestic turkeys are known to lower egg production and affect poult growth and survival without killing or significantly affecting adult hosts. Such pathogens include Salmonella spp. (Williams 1978), certain strains of NDV and AIV (Hanson 1978), and Mycoplasma spp. (Yoder 1978). Information on the occurrence and effects of these pathogens in wild turkeys is scarce. There have been no previous reports of salmonellosis, NDV, or AIV in freeranging populations. Mycoplasmosis, however, has been observed in wild turkeys in at least 2 instances (Davidson et al. 1982, Jessup et al. 1983), and serologic evidence of infection is increasing. A recent decline of wild turkeys on the Uncompaghre Plateau in Colorado was linked to this disease (Adrian 1985). Experimental infections of MG cause significant morbidity in the Rio Grande subspecies (M. g. intermedia) and result in decreased egg production and fertility in captive-reared wild turkeys (Rocke 1985). This study was conducted to determine the role of selected disease causing agents in the recent population decline in wild turkeys at the WWR. The authors are very grateful to J. G. Teer and the staff at the Rob and Bessie Welder Wildlife Foundation (WWF) for providing support and assistance and to personnel at the Chaparrosa, Campo Alegre, and Welder-McCann ranches for granting permission to trap on their properties. The efforts of all those who helped to trap and sample wild turkeys were greatly appreciated. E. T. Thorne collected and provided the samples from turkeys trapped by Tex. Parks and Wildl. Dep. personnel near Clarendon, Tex. Mycoplasma isolates were characterized with the help of H. W. Yoder, S. H. Kleven, and J. M. Bradbury. Research funds were provided by the WWF, Sinton, Tex., and the Coll. Agric. and Life Sci., Univ. Wisconsin, Madison. This is Contrib. 304 of the WWF.

Natural duck hepatitis B virus infection in Australia.

Natural Duck Hepatitis B Virus (DHBV) infection has been studied in Australian ducks. Sera from 430 Pekin Aylesbury cross-bred ducks taken from three separate flocks were examined for duck hepatitis B virus (DHBV) DNA using a DNA dot hybridisation assay. In one flock there was significant infection with DHBV (98/140), but none was detectable in the other two flocks. Episomal DHBV DNA in liver tissue was demonstrated by gel blot hybridisation only in birds with DHBV DNA in serum. Polymerase-labelled DHBV DNA migrated as expected for linear double-stranded DNA 3.1 kilobase (kb) in length. Virus particles with characteristic DHBV morphology were observed in DHBV DNA-positive serum on electron microscopy. No overt morbidity has been noted in naturally infected ducks, but moderately severe hepatitis was found in 3/40 ducks examined histologically. These 3 ducks had DHBV DNA in serum and liver tissue. Mild hepatitis was observed in 27 ducks, but, in these, there was no correlation between the hepatitis and the presence of DHBV in serum or in liver tissue. This is the first report of DHBV in Australia. An animal model may now be established to study aspects of Hepadna virus infection which are pertinent to Hepatitis B virus (HBV) disease in man.