Route Of Introduction Research Articles

Studies of Quantitative Parameters of Virus Excretion and Transmission in Pigs and Cattle Experimentally Infected with Foot-and-Mouth Disease Virus

Foot-and-mouth disease virus (FMDV) can be spread by a variety of mechanisms and the rate of spread, the incubation period and the severity of disease depend on a multitude of parameters, including the strain of virus, the dose received, the route of introduction, the animal species and the husbandry conditions. More knowledge with regard to these parameters is urgently needed to improve resource-efficient disease control. This report describes detailed studies of FMDV load, excretion and transmission in pigs infected with FMDV O UKG 2001, O TAW 1997 and C Noville virus and in cattle infected with the O UKG 2001 virus to facilitate use of a “FMDV load framework” for the assessment of transmission risks. Virus replicated rapidly in pigs and cattle exposed by direct contact. The mean incubation period was around 3–4 days for cattle-to-cattle and 1–3 days for pig-to-pig transmission, depending on the intensity of contact. The results confirmed that a strong relation exists between dose and length of incubation period. Clinical disease was severe in pigs but relatively mild in inoculated cattle; contact infection of cattle appeared to increase the severity of lesions. FMDV RNA was recovered in nasal and mouth swabs from inoculated animals soon after they developed a viraemia and probably reflected the early production and excretion of virus. FMDV RNA in nasal and mouth swabs from contact animals could be detected several days before they showed other signs of infection, indicating the possibility of detecting exposed animals during the incubation period. FMDV RNA could also be detected in swab samples after the viraemic phase. This may have represented background environmental virus that had been trapped in the respiratory tract and mouth. Alternatively, it may have indicated a somewhat slower clearance or half-life of viral RNA or an extended low level of FMDV replication at these sites. The pattern of FMDV RNA concentrations in pigs was closely similar to that in cattle, but the amounts of FMDV RNA were higher.

Impact of the colonisation of Zaprionus (Diptera, Drosophilidae) in different ecosystems of the Neotropical Region: 2 years after the invasion

The drosophilid Zaprionus indianus was not collected in Brazil, despite on-going drosophilid collecting, until 1999. Since 1999 this species has become common in Brazil. We present data on collections of Z. indianus in central Brazil, since its first occurrence in this region, with the goal of discussing its route of introduction in South America and aspects of its adaptation to the environment. Collections made during a 2-year period show different seasonal distribution patterns of this insect. In contrast with the low population sizes registered in 1999, during the summer of 2000 a large proliferation of this insect was detected. We show that Z. indianus is more common in the savanna sites and that its population peaks during the wet season. These preferences are discussed, and the hypothesis that the introduction in South America should have occurred in the southeast region of this continent is defended.

Pathogenesis of BSE.

Before the emergence of bovine spongiform encephalopathy (BSE) and recognition of its zoonotic potential, the major example of the transmissible spongiform encephalopathies (TSEs) of animals was scrapie of sheep. But there is no evidence that scrapie transmits naturally to any species other than sheep and goats. The pathogenesis of scrapie has been studied most in experimental laboratory rodent species. In most experimental models of scrapie, after peripheral non-neural routes of infection, replication of the agent can first be detected in lymphoreticular system (LRS) tissue. When the route of introduction of agent into the body is localized, initial involvement will be in LRS tissue draining the infection site. Thereafter, there is a striking amplification of the agent in the LRS and spread by lymphatic/haematogenous routes, giving widespread dissemination in the LRS. This precedes replication in the CNS, but is not the means by which infection reaches the CNS. There is now substantial evidence from experimental models of scrapie that involvement of the CNS is by peripheral nervous system (PNS) pathways. In some models employing oral exposure the earliest localized LRS replication is in the gut-associated lymphoid tissue (GALT) and autonomic PNS routing to the CNS has been implicated. However, the relative importance of different routes of spread of TSEs within the body is determined by a number of host- and agent-dependent factors and, therefore, generalizations from an experimental model to a natural disease across a species barrier may not be appropriate. With the occurrence of BSE and recognition of its food-borne route of transmission via meat and bone meal, has come greater awareness of the probable importance of the oral route of infection in ruminant species affected by TSEs. In consequence, studies have increasingly focused on the natural host species to examine pathogenetic events.

Grateloupia turuturu (Halymeniaceae, Rhodophyta) is the correct name of the non-native species in the Atlantic known as Grateloupia doryphora

Grateloupia doryphora (Montagne) Howe, originally described from Peru, has repeatedly been reported as an invasive species in Atlantic and Mediterranean waters. Various attempts to explain this species' route of introduction have been unsatisfactory. New evidence from comparative rbcL sequence analysis and morphology suggests that this adventive species in the NE and NW Atlantic corresponds with G. turuturu Yamada, originally described from Japan. This provenance follows a well-recognized trend of invasive marine organisms that have colonized the Atlantic Ocean and Mediterranean Sea from Pacific NE Asia.

Estimating the risk of importation of foot-and-mouth disease into Europe

The opinions of a number of recognised world experts on foot-and-mouth disease (FMD) were sought in order to answer key questions relating to the importation of the disease into European...

Invasibility of a coastal strip in NE Spain by alien plants

Abstract. The alien plant species and the ecological factors that facilitate their invasion to a coastal strip in the Baix Camp region (Tarragona, NE Spain) were studied. A detailed inventory of the area showed that 20% of the plant species, most of them from the American Continent, were aliens, many of which were strongly invasive.At the habitat level, the relationships between the invasive behaviour and a number of autecological, ecological and habitat variables were analysed by means of logistic analyses. In the best model five variables were related to alien plant invasions: climatic affinity, disturbance of the invaded habitat, route of introduction, soil moisture during summer, and life form. To elucidate the environmental factors that could be responsible for alien plant invasions at a regional scale, the number of alien taxa and the environmental features at 13 localities of the western Mediterranean area were analysed. The warm lowlands, subjected to low annual rainfall and high population density, exhibited the greatest reception capacity for alien plants.It is concluded that various specific environmental features – high mean temperatures, the abundance of riparian systems, the existence of biotopes with favourable water balance which harbour a great richness of alien species and the high human pressure to which the enclave is subjected, combined with the ecological requirements of the alien species and certain species attributes (biotype) can interact at different scales and have caused the over‐representation of alien plants.

FIRST OCCURRENCE OF THE BROOK SILVERSIDE (LABIDESTHES SICCULUS) IN LAKE CHAMPLAIN, VERMONT

Abstract The range of brook silverside (Labidesthes sicculus) extends from Minnesota eastward to southern Quebec, and south through New York, Texas, and Florida. The species is found in the St. Lawrence and Richelieu Rivers in Quebec, and the Allegheny and St. Lawrence River drainages, Mohawk and Hudson Rivers in New York. We found brook silverside for the first time in four of the five basins of Lake Champlain, over a range of 150 km, in 1998. Several individuals were collected at each site, indicating that the species is established in the lake. The route of introduction of brook silverside is unclear; they could have entered the lake from the Mohawk River via the Champlain Canal at the south end or from the Richelieu River via the Chambly Canal at the north end. This finding extends the range of brook silverside by approximately 88 km, into Lake Champlain in western Vermont.

Pneumoperitoneum: a review of nonsurgical causes.

To review causes of nonsurgical pneumoperitoneum (NSP), identify nonsurgical etiologies, and guide conservative management where appropriate. We conducted a computerized MEDLINE database search from 1970 to 1999 by using key words pneumoperitoneum and benign, nonsurgical, spontaneous, iatrogenic, barotrauma, pneumatosis, diaphragmatic defects, free air, mechanical ventilation, gynecologic, and pelvic. We identified 482 articles by using these keywords and reviewed all articles. Additional articles were identified and selectively reviewed by using key words laparotomy, laparoscopy, and complications. We reviewed all case reports and reviews of NSP, defined as pneumoperitoneum that was successfully managed by observation and supportive care alone or that required a nondiagnostic laparotomy. Each unique cause of nonsurgical pneumoperitoneum was recorded. When available, data on nondiagnostic exploratory laparotomies were noted. Case reports were organized by route of introduction of air into the abdominal cavity: abdominal, thoracic, gynecologic, and idiopathic. Most cases of NSP occurred as a procedural complication or as a complication of medical intervention. The most common abdominal etiology of NSP was retained postoperative air (prevalence 25% to 60%). NSP occurred frequently after peritoneal dialysis catheter placement (prevalence 10% to 34%) and after gastrointestinal endoscopic procedures (prevalence 0.3% to 25%, varying by procedure). The most common thoracic causes included mechanical ventilation, cardiopulmonary resuscitation, and pneumothorax. One hundred ninety-six case reports of NSP were recorded, of which 45 involved surgical exploration without evidence of perforated viscus. The clinician should maintain a high index of suspicion for nonsurgical causes of pneumoperitoneum and should recognize that conservative management may be indicated in many cases.

The colonizing history ofCapsella in Patagonia (South America)—Molecular and adaptive significance

Twenty-two provenances ofCapsella bursa-pastoris (Brassicaceae) from Patagonia and Tierra del Fuego and 13 provenances from the middle part of South America have been investigated for phenotypic traits (flowering, growth form parameters, fruit characters), isozymes (AAT, GDH, LAP), and RAPDs.Capsella is native to Europe and was introduced into South America in the 16th century. In Patagonia, we detected 23 different multilocus associations, but only five occurred in a frequency of more than 5%. By comparison with the geographic distribution patterns of multilocus genotypes in Europe, we inferred the ancestral European gene pools and the possible introduction routes. A particular multilocus genotype (MMG) was most frequent in the investigated area, and is native to the Iberian Peninsula. This genotype was with all probability introduced by Spaniards into central and northern South America, and it could have reached Patagonia from the north step by step. Other genotypes probably used a direct route from Europe, most likely via British sheep farmers in the second half of the 19th century. Rare genotypes in Patagonia may have been introduced recently by chance, or might be due to multilocus rearrangements in connection with rare outcrossing events. RAPD markers helped to trace colonial gene pools outside Europe and ancestral European gene pools and support the isozyme studies. Correlations between the life history traits and allozyme markers give evidence of the role adaptation may play in the colonizing process.

Infections associated with medical intervention: hepatitis viruses and HGV.

Transfusion and other medical interventions, as well as their non-medical derivatives, have a lot to answer for. Much of HCV infection can be traced back to this route, HGV is still being transmitted in this way and a substantial proportion of HBV in Africa has been spread around by use of contaminated skin-piercing manoeuvres, medical or otherwise. Many practitioners can still remember the days when blood-borne viruses were not a major feature of medical curricula. Unfortunately, patients currently subjected to cost-cutting medical practices, for example use of unscreened blood and re-use of needles, will have to pay the price in years to come. The evolution of these viruses is linked to their route of introduction, but the relationship between variability and clinical outcome is less certain. Nevertheless, variability is important for clinical practice, especially for the design of sensitive diagnostics and highly effective vaccines.

The Aerobiological Pathway of a Fish Pathogen: Survival and Dissemination of Aeromonas salmonicida in Aerosols and its Implications in Fish Health Management

AbstractThe aerobiological (aerosol) pathway of Aeromonas salmonicida subspecies salmonicida (ATCC 33658) was investigated. Results indicate that viable A. salmonicida can travel as an aerosol/droplet spray at least 104.1 cm (limits of the test chamber used) when carried by air currents. Additionally, viable A. salmonicida was recovered from water exposed to an experimentally generated aerosol/droplet spray of A. salmonicida downwind from the contaminant source. It is possible that viable bacterial aquatic animal pathogens can be spread via the airborne route. This possible route of pathogen introduction could effect current management or system designs, especially when aquaculture systems consist of tanks in close proximity.

Experience in 100 transthoracic balloon pumps

We retrospectively reviewed our last 100 consecutive patients who had an intraaortic balloon pump (IABP) placed through the ascending aorta for postoperative cardiogenic shock. Eighty-one patients survived to have their IABP removed and were evaluated for complications. Complications that may have been related to the transthoracic route of IABP introduction included balloon rupture in 6.2% ( 5 / 81 ), cerebral vascular accident in 2.5% ( 2 / 81 ), transient ischemic attack in 1.2% ( 1 / 81 ), bleeding at the IABP arteriotomy site in 3.7% ( 3 / 81 ), and mediastinitis in 3.7% ( 3 / 81 ). Compared with expected rates of development of complications in this high-risk group of patients, it appeared that balloon rupture and mediastinal bleeding were increased because of the transthoracic placement of the IABP. The rates of neurologic events and mediastinal infection do not appear to be increased. Transthoracic IABP placement avoids ischemic problems in the lower extremities and has proved a useful route for IABP introduction.

日本のイネの伝播経路

日本のイネの伝播経路

Epidemic of Q fever in Leszno district in Poland

In 1988 an epidemic of Q fever was detected in Leszno district. During 1973-1985 all 28,066 cattle tested for C. burnetii antibodies were found to be negative. The first seroconversions were found in cows which produced stillborn young. In the following years the number of seropositive cattle increased from 8.4% in 1987 to 21.6% in 1989. In 1988 all animal workers in the district were tested for C. burnetii antibodies. Of 4,264 persons tested, 1,451 (34%) were seropositive. A detailed study of workers and animals on one farm were performed. A herd of animals was found to be seropositive (32.1%), 68% of workers in direct contact with infected animals were seropositive and 29% of persons drinking raw milk. C. burnetii strains have been isolated from ticks, wild animals and birds hunted in close proximity of the farm. The dynamics of C. burnetii infection among animals and humans in this district and the fact that there is no importation of animal herds suggests that the possible route of introduction of Q fever in this area may be with imported semen or breeding bulls. The presence of C. burnetii in ticks and wild animals indicates the transfer of Q fever to the natural environment and its maintenance in this territory.

The Cell Biology of Antigen Processing and Presentation

Histocompatibility molecules are peptide-binding proteins and present antigenic peptides to T cells. In spite of similarity in structure and peptide specificity, class-I and class-II histocompatibility molecules present peptides at different intracellular locations. Class-I molecules present peptides derived from endogenous proteins, but class-II molecules can present peptides from endocytosed (exogenous) antigen as well as endogenous antigen. Binding of antigenic peptides by histocompatibility molecules is a function of their assembly, intracellular trafficking, and endocytosis. For class-I molecules, assembly appears to be the most important step for peptide acquisition, while all three processes can potentially influence class-II antigen presentation. The versatility of peptide binding by class-II MHC molecules is due to its association with the invariant chain which blocks peptide binding during the initial stages of class-II assembly and export and contributes to the endosomal targeting of class-II molecules. Once invariant chain dissociates, class-II molecules become competent to bind peptides and are released to the cell surface. The location in which a particular antigenic peptide is produced is a function both of its route of introduction into the cell and its susceptibility to degradation. These factors contribute significantly to whether an antigen will be presented by class-I or class-II molecules and should be taken into account in the design and development of vaccines.

Evaluation of potential transmission of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin‐contaminated incinerator emissions to humans via foods

Interest in the potential sources of human exposure to TCDD (dioxins, TCDD and equivalents, or 2,3,7,8-tetrachlorodibenzo-p-dioxin) via foods has recently shifted from phenoxy herbicides to products of combustion and waste disposal. Proposals to locate municipal waste combustors in rural areas have raised concerns that emissions, which could contain TCDD, could contaminate animal feeds and such human foods as milk, meat, and vegetables. Important factors that can affect the results of an assessment of incinerator emissions include (1) the emission and deposition rates of TCDD from the source, (2) the fractional retention and half-life of fly ash on plants, (3) the environmental half-life of TCDD, (4) the animal feeding and management systems, (5) the bioavailability of TCDD and related compounds, (6) the metabolism and pharmacokinetics of TCDD in farm animals, (7) food consumption levels, (8) the half-life of TCDD in humans, and (9) the model selected to estimate cancer risk. For persons living in the area of highest deposition near an incinerator, a possible uptake of TCDD from foods of animal origin was estimated to be about 10-40 fg/kg.d, which was much greater than the 1-5 fg/kg.d uptake estimated for foods of plant origin. The total uptake of TCDD from foods by the maximally exposed population will usually be about 500- to 1000-fold greater than that due to inhalation. Although milk was assumed to be the most important food pathway in several previous assessments that evaluated the hazards of airborne emissions, we determined that the deposition-forage-cattle-beef pathway was the more important route of exposure. The previous assessments appear to have used inappropriate pharmacokinetic models for TCDD and to have overestimated pasture use for dairy cows. The amount of TCDD accumulated in soil from airborne emissions was found to be less important than the amount deposited in forage, a finding that is the opposite of the usual conclusions drawn for other routes of TCDD introduction into agricultural environments. Based on the assumption and parameters used in this assessment, the potential human health risks due to TCDD emissions from incinerators are insignificant compared to other background sources of TCDD. It would be desirable to measure TCDD in soil and crops around existing facilities to better evaluate this assessment, but it is likely that concentrations would be too low to reliably quantitate.

Systemically induced photoallergy to quinine in the mouse can be elicited topically--and vice versa

Groups of female albino mice were photosensitized and photochallenged to quinine using protocols for either systemic or epicutaneous administration. Compared with control groups, statistically significant inflammatory reactions, measured as wet weight increase in ear tissue, could be obtained both with systemic and epicutaneous administration. Topically induced photoallergy to quinine could be elicited not only by topical, but also by intraperitoneal administration of the drug, and vice versa. The strongest response at challenge was obtained when the induction was performed topically and the challenge by the systemic route. These data suggest that epicutaneous and systemic photoallergy to quinine have mechanisms in common, and that the route of introduction of the sensitizer into the skin is not the crucial factor. This experimental model may be useful in the elucidation of the mechanisms of systemic photoallergy.

トウガラシ属の種間雑種における座止発現及び座止発現遺伝子の地理的分布

Some cultivars of Capsicum annuum show dwarfness in their interspecific hybrids with C. chinense ′No. 3341′. The dwarfness is represented by the termination of leaf differentiation after development of several leaves in both main and lateral shoots.The dwarf plants generally maintain their growth characteristics for two years. The top/root ratio of the dwarf plants was smaller than in normal plants. Root growth of dwarf plants increased nearly to normal by grafting of normal plants on them.Dwarfness was shown to be controlled by two complemantary dominant genes, one of which is homozygous in ′No. 3341′. Many of the old Japanese cultivars, and the local Korean and Chinese cultivars, had another gene and developed dwarfness in hybrids with ′No. 3341′. All cultivars collected from other Asian areas, the Subcontinent of India, and North and South America did not possess the dwarf gene complementary to the gene of ′No. 3341′, except for one cultivar from Guatemala.There are two theories for the route of pepper introduction to Japan; one by Portuguese and another via Korea. The present genetical studies strongly suggest that some cultivars had been introduced from Korea to Japan.

Polycyclic aromatic hydrocarbons in Washington coastal sediments: an evaluation of atmospheric and riverine routes of introduction

Polycyclic aromatic hydrocarbon (PAH) compositions were characterized monthly over a 1-year period in atmospheric particulate material (APM) collected from three locations in western Washington state and riverine suspended particulate material (SPM) collected near the mouth of the Columbia River. PAH mixtures of APM are dominated by compounds of combustion origin, with minor levels of the resin acid-derived PAH retene often present. SPM contained comparable levels of individual combustion PAH, retene, and perylene. Atmospheric and riverine contributions of individual combustion PAH to the Washington coastal environment were estimated from these data and other available information. Comparison of estimates with respective PAH accumulation rates measured in lead-210 dated coastal sediments shows that >30% of all combustion PAH, retene, and perylene in these sediments is supplied by SPM discharge from the Columbia River and direct atmospheric input accounts for at most 10% of the combustion PAH. Atmospherically transportable PAH are removed from the air over land to soils and freshwaters within the river drainage basin, eroded on particles, and discharged into the Washington coastal environment along with other nonatmospherically transportable PAH such as perylene as intrinsic constituents of the Columbia River's suspended sediment load.

ChemInform Abstract: A NOVEL REACTION AND MECHANISM OF A DIHALOGENATED Δ4‐3‐KETOSTEROID: STEREOELECTRONIC CONTROL IN A COMPLICATED SN2′ DISPLACEMENT

AbstractDie Umsetzung des Dibromcholestenons (I) mit Na‐acetat (II) in Eisessig liefert ein Gemisch aus den Bromacetaten (III), den Acetaten (IV) und den Diaeetaten (V) sowie dem Bromketon (VI).