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1.
Neurosci Biobehav Rev ; 133: 104504, 2022 02.
Article in English | MEDLINE | ID: mdl-34922988

ABSTRACT

Cognitive deficits are well documented in schizophrenia. Here, we reviewed alterations in performance monitoring as potential marker of cognitive deficits in schizophrenia. We found that performance monitoring alterations in schizophrenia are specific to early (indexed by blunted error-related negativity (ERN)) and late (reflected in blunted error positivity (Pe)) internal error processing, while external performance feedback processing in simple response feedback tasks is relatively preserved. We propose, that these performance monitoring deficits may best be interpret as one aspect of disrupted theta band (4-8 Hz) oscillations over medial frontal recordings sites. Midfrontal theta dynamics are an increasingly established direct neural index of the recruitment of cognitive control and are impaired in several clinical populations. While theta-related ERPs (the ERN) may be an easy to assess marker of cognitive deficits in schizophrenia, further work investigating the trial-by-trial dynamics of theta in both the time and time-frequency domain is needed to parse cognitive deficits in schizophrenia into finer levels of detail and evaluate theta modulation as a therapeutic tool.


Subject(s)
Schizophrenia , Case-Control Studies , Electroencephalography , Evoked Potentials/physiology , Humans , Reaction Time/physiology
2.
J Med Entomol ; 58(3): 1384-1388, 2021 05 15.
Article in English | MEDLINE | ID: mdl-33210706

ABSTRACT

We evaluated the potential for mosquitoes collected in the Amazon Basin, near Iquitos, Peru, to become infected with and transmit Murutucu (MURV) and Itaqui viruses (ITQV) (Order Bunyavirales, Family: Peribunyaviridae, Genus: Orthobunyavirus). Viremia levels in Syrian hamsters peaked 2 d after infection with either virus, and both viruses were highly lethal in hamsters with virtually all hamsters dying prior to 3-d postinfection. For almost all of the mosquito species tested some individuals were susceptible to infection and some developed a disseminated infection after oral exposure to either MURV or ITQV. However, only the Culex species (Culex (Culex) coronator Dyar and Knab [Diptera, Culicidae], Culex (Melanoconian) gnomatos Sallum, Huchings, and Ferreira [Diptera, Culicidae], Culex (Mel.) pedroi Sirivanakarn and Belkin [Diptera, Culicidae], and Culex (Mel.) vomerifer Komp [Diptera, Culicidae]) successfully transmitted virus by bite. However, even among these species, only about 37% of the individuals with a disseminated infection successfully transmitted these viruses, indicating a significant salivary gland barrier. Although little is known about the medical or veterinary importance of many members of the genus Orthobunyavirus, we have demonstrated that Culex spp. (Diptera, Culicidae) could be potential vectors.


Subject(s)
Bunyaviridae Infections/transmission , Culicidae/virology , Mosquito Vectors/virology , Orthobunyavirus/isolation & purification , Animals , Female , Mesocricetus , Peru
3.
Transbound Emerg Dis ; 63(1): 56-67, 2016 Feb.
Article in English | MEDLINE | ID: mdl-24661833

ABSTRACT

To determine the prevalence of Bartonella species and identify which species of Bartonella naturally infects the striped field mouse (Apodemus agrarius) in the Republic of Korea (ROK), spleens from 200 mice were assayed by nested polymerase chain reaction (nPCR) targeting the RNA polymerase subunit beta (rpoB) gene and the 16S-23S internal transcribed spacer (ITS) region for members of the genus Bartonella. Utilizing PCR techniques, the prevalence of Bartonella spp. ranged from 31.5% (63/200) to 62.0% (124/200) for the rpoB and ITS gene fragments, respectively. The most prevalent species, Bartonella grahamii, was assigned to 17 genotypes and closely related to the zoonotic pathogens, B. taylorii, B. tribocorum, B. phoceensis and B. henselae, which also were detected. Two Bartonella isolates (KRBG28 and KRBG32) were recovered from blood of A. agrarius captured in Gyeonggi Province, ROK. Comparison of the 16S rRNA, hemin-binding protein E (hbpE), glutamate dehydrogenase 1 (gdh1), invasion-associated protein B (ialB), cell division protein (ftsZ), citrate synthase (gltA), 60 kDa heat shock protein (groEL), rpoB gene fragments and the ITS region sequences from the isolates with GenBank was confirmed as B. grahamii. Phylogenetic analysis based on the alignment of concatenated sequences (4933 bp) of KRBG28 and KRBG32 clustered with B. grahamii, forming an independent clade between Asian and American/European B. grahamii genogroups.


Subject(s)
Bartonella Infections/microbiology , Bartonella/isolation & purification , Mice/microbiology , Animals , Bartonella/classification , Bartonella/genetics , DNA Primers/genetics , Genotype , Phylogeny , Polymerase Chain Reaction/methods , RNA, Ribosomal, 16S/genetics , Republic of Korea , Sequence Analysis, DNA , Spleen/microbiology
5.
Pathog Glob Health ; 106(1): 20-31, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22595271

ABSTRACT

OBJECTIVES: Anopheles gambiae is the primary vector of malaria in sub-Saharan Africa and is a potential target of genetic control programs. We determined the capacity of male A. gambiae created by germline transformation to introduce infertility into stable age-distribution populations. We also determined effects of the transgenes on life history. METHODS: Stable age-distribution populations of A. gambiae mosquitoes were established in large indoor cages. Male mosquitoes carrying an I-PpoI homing endonuclease gene were introduced at ×5 and ×10 release rates where they competed with target male mosquitoes for matings. Similar trials were conducted in small cages with an additional ×1 release level. RESULTS: Infertility was successfully introduced into all target populations. In supporting experiments, complete female infertility was observed in all strains and species of the A. gambiae complex to which transgenic males were mated. Life history experiments demonstrated that reductions in I-PpoI male vigor exist in the form of reduced adult male emergence, longevity and competitiveness. DISCUSSION: A. gambiae I-PpoI males are capable of introducing high levels of infertility in target populations in indoor cage trials. This was accomplished despite losses of vigor resulting from the HEG transgene. These results motivate further trials of sexually I-PpoI A. gambiae in outdoor cage and field trials.


Subject(s)
Anopheles/genetics , Endodeoxyribonucleases/genetics , Infertility, Male/genetics , Pest Control, Biological/methods , Animals , Animals, Genetically Modified/genetics , Anopheles/physiology , Competitive Behavior , Female , Insect Vectors/genetics , Insect Vectors/physiology , Malaria/prevention & control , Malaria/transmission , Male , Sexual Behavior, Animal
6.
Zoonoses Public Health ; 59(3): 164-75, 2012 May.
Article in English | MEDLINE | ID: mdl-22128834

ABSTRACT

The Armed Forces Health Surveillance Center (AFHSC), Division of Global Emerging Infections Surveillance and Response System conducts disease surveillance through a global network of US Department of Defense research laboratories and partnerships with foreign ministries of agriculture, health and livestock development in over 90 countries worldwide. In 2010, AFHSC supported zoonosis survey efforts were organized into four main categories: (i) development of field assays for animal disease surveillance during deployments and in resource limited environments, (ii) determining zoonotic disease prevalence in high-contact species which may serve as important reservoirs of diseases and sources of transmission, (iii) surveillance in high-risk human populations which are more likely to become exposed and subsequently infected with zoonotic pathogens and (iv) surveillance at the human-animal interface examining zoonotic disease prevalence and transmission within and between human and animal populations. These efforts have aided in the detection, identification and quantification of the burden of zoonotic diseases such as anthrax, brucellosis, Crimean Congo haemorrhagic fever, dengue fever, Hantaan virus, influenza, Lassa fever, leptospirosis, melioidosis, Q fever, Rift Valley fever, sandfly fever Sicilian virus, sandfly fever Naples virus, tuberculosis and West Nile virus, which are of military and public health importance. Future zoonotic surveillance efforts will seek to develop local capacity for zoonotic surveillance focusing on high risk populations at the human-animal interface.


Subject(s)
Communicable Diseases, Emerging/epidemiology , Communicable Diseases/epidemiology , Disease Outbreaks/prevention & control , Sentinel Surveillance , Zoonoses/epidemiology , Animals , Communicable Diseases/transmission , Communicable Diseases, Emerging/transmission , Global Health , Humans , Military Medicine , Military Personnel , Seroepidemiologic Studies , United States , Zoonoses/transmission
7.
J Med Entomol ; 45(4): 720-5, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18714873

ABSTRACT

Mosquitoes were collected in the Amazon Basin, near Iquitos, Peru, and used in experimental studies to evaluate their susceptibility to strains of eastern equine encephalitis virus (EEEV) that were isolated from mosquitoes captured within 20 km of Iquitos. When fed on hamsters or chickens with a viremia of 4105 plaque-forming units (PFU) of EEEV/ml, Culex pedroi Sirivanakarn and Belkin, Aedesfulvus (Wiedemann), Psorophora albigenu (Peryassu), and Psorophoraferox (Von Humboldt) were susceptible to infection, whereas none of the Aedes serratus (Theobald), Culex vomerifer Komp, Culex gnomatos Sallum, Huchings, and Ferreira, Culex portesi Senevet and Abonnenc, or Culex coronator Dyar and Knab became infected, even though they fed on the same viremic blood sources. When these mosquito species fed on animals with viremias of approximately 10(8) PFU/ml, Cx. pedroi, Ae.II (Brazil-Peru) and a lineage III (Argentina-Panama) isolate of EEEV. This study, combined with the repeated isolation of strains of EEEV from Cx. pedroi captured in the Amazon Basin region of Peru, suggests that Cx. pedroi may be the primary enzootic vector of EEEV in this region.


Subject(s)
Culicidae/virology , Encephalitis Virus, Eastern Equine/pathogenicity , Aedes/growth & development , Aedes/virology , Animals , Chickens , Cricetinae , Culex/growth & development , Culex/virology , Culicidae/growth & development , Encephalomyelitis, Eastern Equine/prevention & control , Encephalomyelitis, Eastern Equine/transmission , Encephalomyelitis, Eastern Equine/veterinary , Female , Genetic Predisposition to Disease , Peru
8.
J Anim Sci ; 84(4): 938-45, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16543572

ABSTRACT

Relationships between residual feed intake (RFI) and other performance variables were determined using 54 purebred Angus steers. Individual feed intake and BW gain were recorded during a 70-d post-weaning period to calculate RFI. After the 70-d post-weaning test, steers were fed a finishing ration to a similar fat thickness (FT), transported to a commercial facility, and slaughtered. A subsample of carcasses (n = 32) was selected to examine the relationships among RFI, meat quality, and palatability. Steers were categorized into high (> 0.5 SD above the mean; n = 16), medium (mid; +/- 0.5 SD from the mean; n = 21), and low (< 0.5 SD below the mean; n = 17) RFI groups. No differences were detected in ADG, initial BW, and d 71 BW among the high, mid, and low RFI steers. Steers from the high RFI group had a greater DMI (P = 0.004) and feed conversion ratio (FCR; DMI:ADG; P = 0.002) compared with the low RFI steers. Residual feed intake was positively correlated with DMI (r = 0.54; P = 0.003) and FCR (r = 0.42; P = 0.002), but not with initial BW, d 71 BW, d 71 ultrasound FT, initial ultrasound LM area, d 71 ultrasound LM area, or ADG. The FCR was positively correlated with initial BW (r = 0.46; P = 0.0005), d 71 BW (r = 0.34; P = 0.01), and DMI (r = 0.40; P = 0.003) and was negatively correlated with ADG (r = -0.65; P = 0.001). There were no differences among RFI groups for HCW, LM area, FT, KPH, USDA yield grade, marbling score, or quality grade. Reflectance color b* scores of steaks from high RFI steers were greater (P = 0.02) than those from low RFI steers. There was no difference between high and low RFI groups for LM calpastatin activity. Warner-Bratzler shear force and sensory panel tenderness and flavor scores of steaks were similar across RFI groups. Steaks from high RFI steers had lower (P = 0.04) off-flavor scores than those from low RFI steers. Cook loss percentages were greater (P = 0.005) for steaks from low RFI steers than for those from mid RFI steers. These data support current views that RFI is independent of ADG, but is correlated with DMI and FCR. Importantly, the data also support the hypothesis that there is no relationship between RFI and beef quality in purebred Angus steers.


Subject(s)
Animal Feed , Feeding Behavior/physiology , Meat/standards , Animal Nutritional Physiological Phenomena , Animals , Body Composition , Cattle , Diet , Male , Weight Gain
9.
J Med Entomol ; 42(5): 891-8, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16366001

ABSTRACT

As part of a comprehensive study on the ecology of arthropod-borne viruses in the Amazon Basin region of Peru, we assayed 539,694 mosquitoes captured in Loreto Department, Peru, for arboviruses. Mosquitoes were captured either by dry ice-baited miniature light traps or with aspirators while mosquitoes were landing on human collectors, identified to species, and later tested on Vero cells for virus. In total, 164 virus isolations were made and included members of the Alphavirus (eastern equine encephalomyelitis, Trocara, Una, Venezuelan equine encephalomyelitis, and western equine encephalomyelitis viruses), Flavivirus (Ilheus and St. Louis encephalitis), and Orthobunyavirus (Caraparu, Itaqui, Mirim, Murutucu, and Wyeomyia viruses) genera. In addition, several viruses distinct from the above-mentioned genera were identified to the serogroup level. Eastern equine encephalomyelitis virus was associated primarily with Culex pedroi Sirivanakarn & Belkin, whereas Venezuelan equine encephalomyelitis virus was associated primarily with Culex gnomatos Sallum, Huchings & Ferreira. Most isolations of Ilheus virus were made from Psorophora ferox (Von Humboldt). Although species of the Culex subgenus Melanoconion accounted for only 45% of the mosquitoes collected, 85% of the virus isolations were made from this subgenus. Knowledge of the viruses that are being transmitted in the Amazon Basin region of Peru will enable the development of more effective diagnostic assays, more efficient and rapid diagnoses of clinical illnesses caused by these pathogens, risk analysis for military/civilian operations, and development of potential disease control measures.


Subject(s)
Arboviruses/isolation & purification , Culicidae/virology , Environment , Animals , Arboviruses/classification , Arboviruses/genetics , Chlorocebus aethiops , Fluorescent Antibody Technique, Direct , Peru , Reverse Transcriptase Polymerase Chain Reaction , Seasons , Species Specificity , Vero Cells
10.
Vet Microbiol ; 105(1): 65-72, 2005 Jan 05.
Article in English | MEDLINE | ID: mdl-15607085

ABSTRACT

Previous evidence for the presence of chicken anemia virus (CAV) in the gonads of immune specific-pathogen-free chickens raised the question whether this occurs also in commercial breeders. The presence of CAV was investigated by nested PCR in the gonads and spleens of hens from two 55- and 59-week-old, CAV-vaccinated (flocks 2 and 3), and two 48- and 31-week-old non-vaccinated broiler breeder flocks (flocks 1 and 4). In addition, lymphoid tissues of 20-day-old embryos from these hens were also investigated for the presence of CAV. CAV was detected in the gonads and of 5/6 and 11/22 of the vaccinated hens and in some hens also in the spleen alone. Embryos from 7/8 and 5/18 of these hens were positive. In the non-vaccinated flocks, CAV was detected in the gonads of 11/34 and 10/10 hens in flocks 1 and 4, respectively. In addition, 11 birds in flock 1 had positive spleens. CAV DNA was detected in 3/11 and 2/10 of their embryos. CAV-positive gonads and embryos were detected in samples from hens with moderate as well as high VN antibody titers. Vaccinated chickens positive for CAV in the gonads and in their embryos had VN titers ranging from >1:512 to <1:2048. In non-vaccinated chickens, the VN titers of CAV positive chickens ranged from 1:128 to 1:4096. These results demonstrate that CAV genome can remain present in the gonads of hens in commercial broiler breeder flocks even in the presence of high neutralizing antibody titers that have been associated with protection against CAV vertical transmission. It also suggests that transmission to the progeny may occur irrespectively of the level of the humoral immune response in the hens.


Subject(s)
Chick Embryo/virology , Chicken anemia virus/isolation & purification , Chickens , Circoviridae Infections/veterinary , Gonads/virology , Infectious Disease Transmission, Vertical/veterinary , Poultry Diseases/virology , Animals , Antibodies, Viral/blood , Chicken anemia virus/genetics , Circoviridae Infections/transmission , Circoviridae Infections/virology , DNA, Viral/chemistry , DNA, Viral/genetics , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Male , Neutralization Tests/veterinary , Polymerase Chain Reaction/veterinary , Poultry Diseases/transmission , Spleen/virology
11.
Am J Trop Med Hyg ; 64(1-2): 93-7, 2001.
Article in English | MEDLINE | ID: mdl-11425170

ABSTRACT

This report describes Trocara virus, a newly recognized member of the genus Alphavirus, that has been isolated from Aedes serratus mosquitoes collected at two widely separated sites in the Amazon Basin. Biological, antigenic and genetic characteristics of the new virus are given. Results of these studies indicate that Trocara virus is the first member of a newly discovered antigenic complex within the family Togaviridae genus Alphavirus. The public health and veterinary importance of Trocara virus is still unknown.


Subject(s)
Aedes/virology , Alphavirus/genetics , Alphavirus/isolation & purification , Alphavirus/ultrastructure , Animals , Brazil , Complement Fixation Tests , Cricetinae , DNA Primers , Hemagglutination Tests , Mice , Microscopy, Electron , Peru , Polymerase Chain Reaction , RNA, Viral/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction
12.
J Am Mosq Control Assoc ; 17(3): 196-205, 2001 Sep.
Article in English | MEDLINE | ID: mdl-14529088

ABSTRACT

Two field trials for commercially available and experimental mosquito traps variously baited with light, carbon dioxide, octenol, or combinations of these were evaluated in a malarious area at Paekyeon-Ri near Tongil-Chon (village) and Camp Greaves, Paju County, Kyonggi Province, Republic of Korea. The host-seeking activity for common mosquito species was determined using hourly aspirator collections from a human- and propane lantern-baited Shannon trap. The total number of mosquitoes and number of each species captured during the test were compared using 8 x 8 and 5 x 5 Latin square designs based on trap location. Significant differences were observed for the total number of mosquitoes collected in the 8 x 8 test, such that counterflow geometry (CFG) with CO2 > or = CFG with CO2 and octenol > or = Shannon trap > or = Mosquito Magnet with octenol > American Biophysics Corporation (ABC) light trap with light, CO2 (500 ml/min), and octenol > or = ABC light trap with light and dry ice > or = ABC light trap with light and CO2 > ABC light trap with light only. A concurrent 5 x 5 test found significant differences in trap catch, where Mosquito Magnet with octenol > New Jersey light trap > or = EPAR Mosquito Killer with CO2 > or = ABC light trap with light and dry ice > Centers for Disease Control (CDC) light trap (manufactured by John W. Hock) with light and octenol. Significant differences in trap catch were noted for several species including: Aedes vexans, Anopheles sinensis, An. yatsushiroensis, An. lesteri, Culex pipiens, and Cx. orientalis. Traps baited with octenol captured significantly fewer Cx. pipiens than those not baited with octenol. Likewise, no Cx. orientalis were captured in octenol-baited traps. Host-seeking activity showed a similar bimodal pattern for all species captured. Results from these field trap evaluations can significantly enhance surveillance efforts. Significantly greater numbers of mosquitoes were captured with mosquito traps using counterflow technology (e.g., Mosquito Magnet and CFG traps) when compared to standard light and carbon dioxide-baited traps. Additionally, field evaluations demonstrate that various traps can be utilized for isolation and detection of arboviruses and other pathogens.


Subject(s)
Carbon Dioxide/pharmacology , Culicidae , Environmental Monitoring/methods , Malaria/transmission , Animals , Disease Transmission, Infectious , Humans , Korea , Light , Movement , Octanols/pharmacology , Population Dynamics
13.
J Med Entomol ; 37(6): 835-9, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11126537

ABSTRACT

Mosquitoes collected in the Amazon Basin, near Iquitos, Peru, were evaluated for their susceptibility to epizootic (IAB and IC) and enzootic (ID and IE) strains of Venezuelan equine encephalomyelitis (VEE) virus. After feeding on hamsters with a viremia of approximately 10(8) plaque-forming units of virus per milliliter, Culex (Melanoconion) gnomatus Sallum, Huchings, & Ferreira, Culex (Melanoconion) vomerifer Komp, and Aedes fulvus (Wiedemann) were highly susceptible to infection with all four subtypes of VEE virus (infection rates > or = 87%). Likewise, Psorophora albigenu (Peryassu) and a combination of Mansonia indubitans Dyar & Shannon and Mansonia titillans (Walker) were moderately susceptible to all four strains of VEE virus (infection rates > or = 50%). Although Psorophora cingulata (Fabricius) and Coquillettidia venezuelensis (Theobald) were susceptible to infection with each of the VEE strains, these two species were not efficient transmitters of any of the VEE strains, even after intrathoracic inoculation, indicating the presence of a salivary gland barrier in these species. In contrast to the other species tested, both Culex (Melanoconion) pedroi Sirivanakarn & Belkin and Culex (Culex) coronator Dyar & Knab were nearly refractory to each of the strains of VEE virus tested. Although many of the mosquito species found in this region were competent laboratory vectors of VEE virus, additional studies on biting behavior, mosquito population densities, and vertebrate reservoir hosts of VEE virus are needed to incriminate the principal vector species.


Subject(s)
Culex/virology , Culicidae/virology , Encephalitis Virus, Venezuelan Equine/pathogenicity , Insect Vectors/virology , Animals , Cricetinae , Culex/physiology , Culicidae/physiology , Female , Humans , Insect Vectors/physiology
14.
J Med Entomol ; 37(6): 919-23, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11126550

ABSTRACT

Repellent efficacy of N,N-diethyl-3-methyl-benzamide (deet), the piperidine, 1-[3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine (AI3-37220), and a 1:1 ratio of deet + AI3-37220 were evaluated topically (0.25 mg/cm2 applied in ethanol solution) on human volunteers against the mosquito Aedes communis (DeGeer) and the black fly Simulium venustum Say. The average repellency of all three formulations was > 95% at 4 h. For both mosquitoes and black flies, deet alone provided < 90% protection at 6 h, whereas AI3-37220 provided > 95% protection. Although repellent treatments were not significantly different overall, the contrasts between AI3-3720 versus deet were significant at 6 and 8 h. The 95% confidence interval on percent repellency at 6 h ranged from 90.1 to 98.9% for AI3-37220 versus 64.3 to 82.2% for deet, and at 8 h ranged 76.1 to 88.5% for AI3-37220 versus 47.8 to 64.0% for deet. Similarly, the confidence interval for protection against black flies at 6 h by (AI3-37220 ranged from 86.3 to 99.5% and did not overlap with the confidence interval provided by deet alone (51.2 to 78.8%). There was no evidence of synergistic repellency from a combination of the two compounds; i.e., protection from combined compounds was no better than either repellent used alone.


Subject(s)
Aedes , DEET , Insect Control , Insect Repellents , Piperidines , Simuliidae , Animals , Female , Humans , Insect Control/methods , Mosquito Control/methods , New York
15.
J Am Mosq Control Assoc ; 16(3): 210-8, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11081648

ABSTRACT

A checklist of the mosquito fauna encountered during arboviral studies in Iquitos, Peru, is presented. A total of 16 genera, 30 subgenera, and 96 species were identified, including 24 species reported from Peru for the 1st time. Notations on the taxonomy and biology for 28 species are also provided.


Subject(s)
Culicidae , Aedes , Animals , Anopheles , Culex , Female , Male , Peru , Population Surveillance
16.
Am J Trop Med Hyg ; 62(6): 698-701, 2000 Jun.
Article in English | MEDLINE | ID: mdl-11304057

ABSTRACT

To evaluate the transmission risk of four live dengue (DEN) vaccine candidates developed by the U.S. Army (DEN-1, 45AZ5 PDK 20; DEN-2, S16803 PDK 50; DEN-3, CH53489 PDK 20; and DEN-4, 341750 PDK 20), we tested 3,010 Aedes aegypti and 1,576 Aedes albopictus mosquitoes blood-fed on 21 volunteers who had been administered one of the four vaccine candidates or the licensed yellow fever (YF) vaccine (17D). We used an indirect immunofluorescence assay (IFA) to detect DEN or YF viral antigen in the heads of mosquitoes. Corresponding to the lack of a detectable viremia among volunteers inoculated 8-13 days previously with live DEN-1 or DEN-2 vaccine candidates, only six mosquitoes developed disseminated infections after feeding on these volunteers. These six mosquitoes included 4 of 247 Ae. albopictus fed on volunteers inoculated with the DEN-1 vaccine candidate and 2 of 528 Ae. aegypti fed on volunteers inoculated with the DEN-2 vaccine candidate. Infection was confirmed in each of these IFA-positive mosquitoes by isolating infectious virus from the mosquito's body in Vero-cell culture. None of the 1,252 or the 969 mosquitoes fed on DEN-3 or DEN-4 recipients, respectively, were infected. Overall, dissemination rates in Ae. albopictus and Ae. aegypti were low. Dissemination rates were 0.5%, 0.3%, < 0.1%, and < 0.1% for the DEN-1 through DEN-4 vaccine candidates, respectively. Because of the observed low dissemination rates, it is unlikely that these vaccine viruses would be transmitted under natural conditions.


Subject(s)
Aedes/virology , Dengue Virus/physiology , Dengue/transmission , Insect Vectors/virology , Viral Vaccines , Aedes/physiology , Animals , Dengue/virology , Dengue Virus/immunology , Feeding Behavior , Fluorescent Antibody Technique, Indirect , Humans , Insect Vectors/physiology , Vaccines, Attenuated
17.
J Am Mosq Control Assoc ; 15(3): 342-7, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10480126

ABSTRACT

Four repellents, N,N-diethyl-3-methyl-benzamide (deet), 2-hydroxy-methyl-cyclohexyl acetic acid lactone (CIC-4), and 2 piperidines (1-[3-cyclohexen-1-ylcarbonyl] piperidine [AI3-35765] and 1-[3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine [AI3-37220]) were evaluated alone and in combination against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus using a modified in vitro test system. This method was a valuable tool for comparing effective concentrations of the new compounds. Because of the controlled conditions of the test, it was possible to use the results of assays that had been conducted over a 5-year period and to perform the many replications necessary to evaluate combinations of compounds. The new candidate repellents were generally as effective as deet. Although speculative at this time, there was some evidence of synergistic interaction. Repellent combinations of CIC-4/AI3-37220/AI3-35767, deet/AI3-35765, and deet/AI3-37220/AI3-35765 against An. stephensi and CIC-4/AI3-35765, deet/AI3-37220/AI3-35765, AI3-37220/AI3-35765, and CIC-4/AI3-37220 against Ae. aegypti were more effective than the component compounds alone.


Subject(s)
Insect Repellents , Mosquito Control , Aedes , Animals , Anopheles , Chromones , Culex , DEET , Evaluation Studies as Topic , Female , Mosquito Control/methods , Piperidines
18.
J Anim Sci ; 76(7): 1869-74, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9690642

ABSTRACT

The longissimus muscles (LM) from 12 lambs (eight = callipyge [CLPG] and four = normal [NML]; 48 kg) were used to 1) assess the effect of freezing with or without prior immersion in liquid nitrogen on calpastatin activity (CA) and on Warner-Bratzler shear force (WBS) in CLPG, 2) determine the freezing time required to reduce CA and WBS of CLPG to that of NML, and 3) compare sensory panel ratings for CLPG that is aged fresh to CLPG that is aged after freezing. At 24 h postmortem, chops (.64 and 2.54 cm) were removed from each CLPG LM and randomly assigned within side to one of six freezing times (0, 2, 4, 8, 20, and 42 d). Left-side chops were vacuum-packaged and frozen at -20 degrees C for the assigned time (FROZEN) and right-side chops were treated similarly, except that they were frozen in liquid nitrogen first (FLASH). After freezing for the assigned time, the .64-cm chop was immediately assayed for CA, and 2.54-cm chop was thawed, aged at 2 degrees C for 14 d, and refrozen for subsequent WBS measurement. Chops (.64 and 2.54 cm) were also removed from the longissimus of NML lamb carcasses. The d-0 CLPG and NML chops (2.54 cm) were vacuum-packaged, aged at 2 degrees C for 14 d, and frozen for subsequent WBS measurement. Calpastatin activity did not differ between freezing treatments (P = .99) or with the freezing treatment x freezing time interaction (P = .80). Freezing reduced (P = .01) CA in CLPG by 44% from d 0 to d 42. Calpastatin activity for CLPG was similar (P > .05) to that of NML lamb after freezing for 8, 20, or 42 d. Freezing at -20 degrees C for 42 d and then aging for 14 d reduced (P = .01) WBS in CLPG by 44% from d-0 values. Shear force values for CLPG-FROZEN were similar (P > .05) to NML after 8, 20, or 42 d of freezing. Sensory panel tenderness scores were higher (P < .05) for CLPG aged after freezing 42 d than for those aged fresh. Juiciness and flavor ratings did not differ (P > .05) between CLPG aged fresh or after freezing. Freezing for at least 8 d before aging seems to be a viable method for increasing the tenderness of CLPG LM without reducing juiciness or flavor ratings.


Subject(s)
Calcium-Binding Proteins/metabolism , Freezing , Frozen Foods/standards , Meat/standards , Muscle, Skeletal/metabolism , Adult , Animals , Body Composition , Consumer Behavior , Humans , Male , Middle Aged , Nitrogen , Phenotype , Postmortem Changes , Random Allocation , Sheep , Taste
19.
Meat Sci ; 49(1): 19-26, 1998 May.
Article in English | MEDLINE | ID: mdl-22063181

ABSTRACT

The present experiments were conducted to determine if tenderness differed between normal (N) and callipyge (CLPG) lamb during post-mortem aging of: (1) longissimus muscle (LM), (2) semimembranosus muscle (SM), and (3) LM after freezing for 6 weeks. In the LM, CLPG chops were tougher (p < 0.01) than N at every post-mortem age and after 24 h CaCl(2) marination of a day 1 chop. Post-mortem aging reduced (p < 0.05) shear force of the LM in both N and CLPG; however, this reduction proceeded at a slower rate (-0.127 vs -0.341 kg d(-1); p = 0.01) and for a longer time period (24 vs 6 days; p < 0.05) in CLPG than N. In the SM muscle, shear force values did not differ (p > 0.05). due to phenotype, post-mortem age, or the two-way interaction. Freezing prior to aging accelerated the rate of post-mortem tenderization in CLPG (-0.130 vs -0.060 kg d(-1); p = 0.004) while no changes (p > 0.05) were observed for N. Phenotypic expression of the CLPG gene increased the toughness of the LM with no change in SM; however, freezing prior to aging accelerated the post-mortem tenderization process in CLPG LM.

20.
J Med Entomol ; 33(6): 990-1, 1996 Nov.
Article in English | MEDLINE | ID: mdl-8961653

ABSTRACT

In total, 414 anophelines, consisting of Anopheles karwari (James), An. splendidus Koidzumi, An. dirus Peyton & Harrison, and An. barbirostris Van der Wulp were collected in 2 provinces in eastern Thailand and tested by enzyme-linked immunosorbent assay for the presence of circumsporozoite proteins. Plasmodium vivax CS protein was detected in 3.4% (2/54) of An. karwari and 4.8% (2/42) of An. barbirostris specimens. Both P. vivax phenotypes, Pv247 and Pv210, were found in An. karwari, whereas only Pv247 was detected in An. barbirostris. Plasmodium falciparum CS protein was detected only in 0.3% (1/276) of An. dirus. Results indicate that An. barbirostris may play a role in the transmission of P. vivax in Chanthaburi Province, Thailand.


Subject(s)
Anopheles/parasitology , Antigens, Protozoan/analysis , Plasmodium falciparum/isolation & purification , Plasmodium vivax/isolation & purification , Protozoan Proteins/analysis , Animals , Humans , Plasmodium falciparum/immunology , Plasmodium vivax/immunology , Thailand
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