Parasite mortality

Host resistance Bacterial models—Listeria monocytogenes (mortality or spleen clearance) Streptococcus species (mortality) Viral models—influenza (mortality) Parasitic models—Plasmodium yoelii (parasitemia) or Trichinella spiralis (muscle larvae counts and worm expulsion) Syngeneic tumor models—PYB6 sarcoma (tumor incidence) B16F10 melanoma (lung burden). 

The immune system of the mouse may also be susceptible to the effects of acute oral exposures to di-/ -octylphthalate (Dogra et al. 1989). Three-month-old Swiss albino mice were exposed to di-n-octylphthalate by gavage for 5 days at 0, 650, or 2,600 mg/kg/day (acute LD50 was 13,000 mg/kg). Mice were subsequently exposed by intraperitoneal injection to either encephalomyocarditis virus or the malarial protozoan, Plasmodium berghei. Maximum mortality levels were reached 8-10 days after viral infection and were 20% (0 mg/kg/day), 40% (650 mg/kg/day), and 70% (2,600 mg/kg/day). Malarial lethality reached plateau levels 4-11 days postinfection of approximately 20% (0 mg/kg/day), 25% (650 mg/kg/day), and 70% (2,600 mg/kg/day), then increased to 55%, 70%, and 85%, respectively, by postinfection day 19. Respective mean survival times were calculated to be 13.50, 12.15, and 6.25 days. During the first 14 days after protozoal infection, the percentage of mouse erythrocytes infected with the parasite in the high-dose... 

For keyhole limpet hemocyanine (KLH) both antibody responses and delayed type hypersensitivity (DTH) reactions can be determined [43—45]. In addition several infectious models, including bacterial, viral and parasitic infections may be used to challenge the immune system [18,46]. As survival and eradication of the infections is the primary function of the immune system, these models provide direct information on the functional status of the immune system. Direct immunotoxic compounds will induce immunosuppression and thus an increase in infection rate and/or severity of the infection. The number of infectious agents (bacteria, parasites, or viral colonyforming units), increased morbidity and mortality are indications for an immunotoxic effect. Also a reduction in specific antibody levels in animals treated with the test compound compared to nontreated controls indicates immunosuppression. 

Systemic infections are those that have microorganisms (bacteria, viruses, yeasts, parasites) spread, usually via the bloodstream, beyond the portal of entry or original site of localized infection to multiple compartments of the body. When infections, either localized or systemic, are accompanied by signs and symptoms of a systemic inflammatory response (fever, rapid pulse, increase in white blood cells) the syndrome is called sepsis. Severe sepsis is defined by the additional occurrence of organ failure (either kidney, liver, brain, lungs), and is a potentially fatal condition (mortality around 50%). If there is hypotension not responding on fluid resuscitation it is called septic shock and the mortally is even higher (60-70%). 

Hellothls egg mortality from this parasite on other tobacco is negligible because the tiny parasitic wasp becomes stuck in the exudate (41). 

Vaccines need to be developed against diseases with high mortality rates, such as AIDS, pneumonic plague, acute respiratory infections, diarrhea, and parasitic diseases such as malaria. 

Ndumu et al. evaluated the effectiveness of Azadirachta indica seed oil against the larvae of this parasite [95]. They administered the oil as hydroalcoholic solutions ranging 4.2-100% and computed the mortality within 60 hours. Authors observed that the mortality of larvae was concentration and time dependent 100% mortality was observed with 100% pure neem oil after 48 h. The LD50 of different concentrations were 33.3% (56 h) and 66.7% (48 h). Author also observed little or no adverse effects on treated animals. Furthermore, they stated that the open wound caused by tick bites and therefore exposed to potential fungal and bacterial attacks, could be protected by the microbicidal properties of the neem oil. Previously, the effectiveness of neem oil was also observed by Williams and Mansingh against another tick species of the same genus, A. cajennense, another cattle tick [96]. 

All the tested substances were placed in 6 cm airtight petri dishes and resulted toxic for the mites, that were immobilized within 15 min to 1 h. Linalyl acetate and camphor were active only at the highest doses (6 xl/dish), with 96.7% and 30.0% mortality, respectively. The essential oil showed 98.3% mortality at 0.50 pi (100% at 2 pi), while linalool was the most effective compound (96.7% at 0.25 pi, 100% at 0.50 pi). In further research on the essential oil of L. angustifolia and its constituent linalool, we evaluated the activity of this essential oil on the same parasite using inhalation, rather than direct contact between mites and compounds... 

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