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ZusammenfassungDie COVID-19-Pandemie stellt derzeit weltweit eine Herausforderung dar. In Österreich konnte eine Krise innerhalb des medizinischen Versorgungssystems bisher verhindert werden. Die Behandlung von Patienten mit ambulant erworbener Pneumonie („community acquired pneumonia“, CAP), inklusive durch SARS-CoV-2-Infektionen, sollte sich auch während der Pandemie weiterhin an evidenzbasierten CAP-Leitlinien orientieren. COVID-19-spezifische Anpassungen sind jedoch sinnvoll. Die Behandlung von Patienten mit chronischen Lungenerkrankungen muss während der Pandemie angepasst werden, ist aber weiterhin zu gewährleisten.

Analogues structurally related to anaplastic lymphoma kinase (ALK) inhibitor 1 were optimized for metabolic stability. The results from this endeavor not only led to improved metabolic stability, pharmacokinetic parameters, and in vitro activity against clinically derived resistance mutations but also led to the incorporation of activity for focal adhesion kinase (FAK). FAK activation, via amplification and/or overexpression, is characteristic of multiple invasive solid tumors and metastasis. The discovery of the clinical stage, dual FAK/ALK inhibitor 27b, including details surrounding SAR, in vitro/in vivo pharmacology, and pharmacokinetics, is reported herein.

Evolution of the process strategies to prepare CEP-28122, an anaplastic lymphoma kinase (ALK) inhibitor, is presented. The initial medicinal chemistry route, used for the preparation of key supplie...

There are numerous published studies establishing a link between reactive metabolite formation and toxicity of various drugs. Although the correlation between idiosyncratic reactions and reactive metabolite formation is not 1:1, the association between the two is such that many pharmaceutical companies now monitor for reactive metabolites as a standard part of drug candidate testing and selection. The most common method involves in vitro human microsomal incubations in the presence of a thiol trapping agent, such as glutathione (GSH), followed by LC/MS analysis. In this study, we describe several 2,7-disubstituted-pyrrolotriazine analogues that are extremely potent reactive metabolite precursors. Utilizing a UPLC/UV/MS method, unprecedented levels of GSH adducts were measured that are 5-10 times higher than previously reported for high reactive metabolite-forming compounds such as clozapine and troglitazone.

A novel 2,7-disubstituted-pyrrolo[2,1-f][1,2,4]triazine scaffold has been designed as a new kinase inhibitor platform mimicking the bioactive conformation of the well-known diaminopyrimidine motif. The design, synthesis, and validation of this new pyrrolo[2,1-f][1,2,4]triazine scaffold will be described for inhibitors of anaplastic lymphoma kinase (ALK). Importantly, incorporation of appropriate potency and selectivity determinants has led to the discovery of several advanced leads that were orally efficacious in animal models of anaplastic large cell lymphoma (ALCL). A lead inhibitor (30) displaying superior efficacy was identified and in depth in vitro/in vivo characterization will be presented.

Pharmaceutical approaches to slow the progression of Alzheimer's disease (AD) have focused primarily on reducing production or increasing clearance of amyloid b peptide (Ab). Recent clinical trial results question the efficacy of targeting Ab for treatment of mild to moderate AD, highlighting the need for alternate approaches. With the marketing of eight kinase inhibitors for oncology indications as of 2008 (Gleevec s , Tarceva s , Nexavar s , Sutent s , Rapamune s , Sprycel s , Tasigna s , and Tykerb s ) and current clinical trials of more than 150 others for a number of indications, the progress that has been made in improving the selectivity and pharmaceutical properties of this class of compounds suggests that targeting neurodegenerative diseases such as AD may be possible. The present review describes a number of kinase targets for AD that have been studied in relation to tau protein pathology, neuroinflammation and neuron loss, in addition to amyloid pathology. Drug Dev Res 70 : 125-144, 2009. r 2009 Wiley-Liss, Inc.

Among the known angiogenic growth factors and cytokines implicated in the modulation of normal and pathological angiogenesis, the VEGF family (VEGF-A, VEGF-B, VEGF-C, VEGF-D) and their corresponding receptor tyrosine kinases [VEGFR-1 (Flt-1), VEGFR-2 (Flk-1, KDR), and VEGFR-3 (Flt-4)] play a paramount and indispensable role in regulating the multiple facets of the angiogenic and lymphangiogenic processes, as well as the induction of vascular permeability and inflammation. The receptor VEGFR-2/KDR is the principal one through which VEGFs exert their mitogenic, chemotactic, and vascular permeabilizing effects on the host vasculature. Increased expression of VEGFs by tumor cells and VEGFR-2/KDR and VEGFR-1/Flt-1 by the tumor-associated vasculature are a hallmark of a variety of human and rodent tumors in vivo and correlates with tumor growth rate, micro-vessel density/proliferation, tumor metastatic potential, and poorer patient prognosis in a variety of malignancies. Approaches to disrupting the VEGF/VEGFR signaling cascade range from biological agents (soluble receptors, anti-VEGF and anti-VEGFR-2 antibodies, and VEGF transcription inhibitors) to small molecule ATP competitive VEGFR inhibitors. Examples from this latter class that are currently in clinical development include compounds from distinct chemical classes such as: indolin-2-ones, anilinoquinazolines, anilinophthalazines, isothiazoles, indolo- and indenocarbazoles. The structure activity relationships, biochemical and pharmacological profile of optimized representatives from each of these classes constitute the subject matter of this review.

Members of the JAK family of nonreceptor tyrosine kinases play a critical role in the growth and progression of many cancers and in inflammatory diseases. JAK2 has emerged as a leading therapeutic target for oncology, providing a rationale for the development of a selective JAK2 inhibitor. A program to optimize selective JAK2 inhibitors to combat cancer while reducing the risk of immune suppression associated with JAK3 inhibition was undertaken. The structure-activity relationships and biological evaluation of a novel series of compounds based on a 1,2,4-triazolo[1,5-a]pyridine scaffold are reported. Para substitution on the aryl at the C8 position of the core was optimum for JAK2 potency (17). Substitution at the C2 nitrogen position was required for cell potency (21). Interestingly, meta substitution of C2-NH-aryl moiety provided exceptional selectivity for JAK2 over JAK3 (23). These efforts led to the discovery of CEP-33779 (29), a novel, selective, and orally bioavailable inhibitor of JAK2.

Anaplastic lymphoma kinase (ALK) is a pro- mising therapeutic target for the treatment of cancer, supported by considerable favorable preclinical and clinical activities over the past several years and culminating in the recent FDA approval of the ALK inhibitor crizotinib. Through a series of targeted modifications on an ALK inhibitor diaminopyrimidine scaffold, our research group has driven improvements in ALK potency, kinase selectivity, and overall pharmaceutical properties. Optimization of this scaff old has led to the identification of a potent and efficacious inhibitor of ALK, 25b .As triking feature of25b over previously described ALK inhibitors is its >600-fold selectivity over insulin receptor (IR), a closely related kinase family member. Most importantly, 25b exhibited dose proportional escalation in rat compared to compound 3 which suffered dose limiting absorption preventing further advancement. Compound 25b exhibited significant in vivo antitumor efficacy when dosed orally in an ALK-positive ALCL tumor xenograft model in SCID mice, warranting further assessment in advanced preclinical models.

Anaplastic lymphoma kinase (ALK) is constitutively activated in a number of human cancer types due to chromosomal translocations, point mutations, and gene amplification and has emerged as an excellent molecular target for cancer therapy. Here we report the identification and preclinical characterization of CEP-28122, a highly potent and selective orally active ALK inhibitor. CEP-28122 is a potent inhibitor of recombinant ALK activity and cellular ALK tyrosine phosphorylation. It induced concentration-dependent growth inhibition/cytotoxicity of ALK-positive anaplastic large-cell lymphoma (ALCL), non-small cell lung cancer (NSCLC), and neuroblastoma cells, and displayed dose-dependent inhibition of ALK tyrosine phosphorylation in tumor xenografts in mice, with substantial target inhibition (>90%) for more than 12 hours following single oral dosing at 30 mg/kg. Dose-dependent antitumor activity was observed in ALK-positive ALCL, NSCLC, and neuroblastoma tumor xenografts in mice administered CEP-28122 orally, with complete/near complete tumor regressions observed following treatment at doses of 30 mg/kg twice daily or higher. Treatment of mice bearing Sup-M2 tumor xenografts for 4 weeks and primary human ALCL tumor grafts for 2 weeks at 55 or 100 mg/kg twice daily led to sustained tumor regression in all mice, with no tumor reemergence for more than 60 days postcessation of treatment. Conversely, CEP-28122 displayed marginal antitumor activity against ALK-negative human tumor xenografts under the same dosing regimens. Administration of CEP-28122 was well tolerated in mice and rats. In summary, CEP-28122 is a highly potent and selective orally active ALK inhibitor with a favorable pharmaceutical and pharmacokinetic profile and robust and selective pharmacologic efficacy against ALK-positive human cancer cells and tumor xenograft models in mice. Mol Cancer Ther; 11(3); 670–9. ©2011 AACR.

The elaboration of a novel scaffold for the inhibition of JAK2 and FAK kinases was targeted in order to provide a dual inhibitor that could target divergent pathways for tumor cell progression.

Accumulating evidence suggests that autoreactive plasma cells play an important role in systemic lupus erythematosus (SLE). In addition, several proinflammatory cytokines promote autoreactive B cell maturation and autoantibody production. Hence, therapeutic targeting of such cytokine pathways using a selective JAK2 inhibitor, CEP-33779 (JAK2 enzyme IC50 = 1.3 nM; JAK3 enzyme IC50/JAK2 enzyme IC50 = 65-fold), was tested in two mouse models of SLE. Age-matched, MRL/lpr or BWF1 mice with established SLE or lupus nephritis, respectively, were treated orally with CEP-33779 at 30 mg/kg (MRL/lpr), 55 mg/kg or 100 mg/kg (MRL/lpr and BWF1). Studies included reference standard, dexamethasone (1.5 mg/kg; MRL/lpr), and cyclophosphamide (50 mg/kg; MRL/lpr and BWF1). Treatment with CEP-33779 extended survival and reduced splenomegaly/lymphomegaly. Several serum cytokines were significantly decreased upon treatment including IL-12, IL-17A, IFN-α, IL-1β, and TNF-α. Anti-nuclear Abs and frequencies of autoantigen-specific, Ab-secreting cells declined upon CEP-33779 treatment. Increased serum complement levels were associated with reduced renal JAK2 activity, histopathology, and spleen CD138+ plasma cells. The selective JAK2 inhibitor CEP-33779 was able to mitigate several immune parameters associated with SLE advancement, including the protection and treatment of mice with lupus nephritis. These data support the possibility of using potent, orally active, small-molecule inhibitors of JAK2 to treat the debilitative disease SLE.

The JAK2/STAT pathway has important roles in hematopoiesis. With the discovery of the JAK2 V617F mutation and its presence in many patients with myeloproliferative neoplasms, research in the JAK2 inhibitor arena has dramatically increased. We report a novel series of potent JAK2 inhibitors containing a 2,7-pyrrolotriazine core. To minimize potential drug-induced toxicity, targets were analyzed for the ability to form a glutathione adduct. Glutathione adduct formation was decreased by modification of the aniline substituent at C2.

Organic films have been found to develop on window surfaces [Diamond et al., Environmental Science and Technology 34 (2000a) 2900]. The film contains organic compounds that are in dynamic equilibrium with the gas-phase in air, and organic and inorganic compounds and elements associated with deposited air particles. In this study, the exterior surfaces of windows were sampled in downtown and suburban Baltimore, Maryland. Higher concentrations of PCBs, PAH, metals and trace elements were found at downtown than a suburban site. PCBs in the films at downtown sites were dominated by penta and hexa homologue groups and PAH signatures resembled that of vehicle emissions. Twenty-six metals and trace elements were separated into two groups according to their enrichment factors (EF). Ag, Hg, Se, Sb and Zn had EF > 100, suggesting anthropogenic sources of these metals in the films; whereas Fe, Ca, Co, Cr and others had EF

Anaplastic lymphoma kinase (ALK) was originally identified as the oncogenic NPM (nucleophosmin)-ALK fusion protein due to a t (2;5) chromosomal translocation in anaplastic large cell lymphomas (ALCL). Many other chromosomal rearrangements or gene mutations/amplification leading to enhanced ALK activity have subsequently been identified and characterized in a number of human cancer types. The recent reports of EML4 (echinoderm microtubule-associated protein-like 4)-ALK oncogenic proteins in non-small cell lung cancer (NSCLC) and the identification of ALK activating point mutations and gene amplification in neuroblastoma have indicated ALK as a potential major therapeutic target for human cancers. Here we report the identification and preclinical characterization of CEP-28122, a highly potent and selective orally active ALK inhibitor. CEP-28122 is a potent inhibitor of recombinant ALK activity (IC50 of 3 nM) and NPM-ALK tyrosine phosphorylation in ALCL cells (IC50 of 20-30 nM). It is selective over a broad panel of protein kinases and a panel of receptors and ion channels with greater than 300-fold selectivity for insulin receptor. CEP-28122 induced concentration-dependent growth inhibition and cytotoxicity of ALK-positive ALCL and NSCLC cells with minimal activity against ALK-negative lymphoma and leukemia cells as well as ALK-negative NSCLC cells at concentrations up to 3 μM. CEP-28122 exhibited favorable oral bioavailability (F = 37-71% across species) with adequate tissue distribution in rodents. It displayed dose-dependent inhibition of NPM-ALK tyrosine phosphorylation in human ALCL tumor xenografts in mice with complete target inhibition (> 90%) for more than 12 h following single oral dosing at 30 mg/kg. Dose-dependent anti-tumor activity was observed in NPM-ALK-positive Sup-M2 and Karpas-299 ALCL tumor xenografts and EML4-ALK-positive NCI-H2228 and NCI-H3122 tumor xenografts in mice dosed with CEP-28122, bid, po, with complete or near complete tumor regressions observed following 2 weeks of treatment with CEP-28122 at 30 mg/kg or higher. Treatment of mice bearing Sup-M2 tumor xenografts or primary human ALCL tumorgrafts with CEP-28122 at 55 or 100 mg/kg bid, po, for 4 weeks led to sustained tumor regression in all mice, with no tumor re-emergence in any mouse up to 60 days post cessation of CEP-28122 treatment. On the contrary, CEP-28122 displayed marginal anti-tumor activity against ALK-negative lymphoma and NSCLC tumor xenografts under the same dosing regimens. It was well tolerated with all dosing regimens in mice and rats with no overt toxicity and no compound-related body weight loss. CEP-28122 advanced into preclinical development based on its potency, selectivity and overall favorable pharmacological, pharmaceutical and safety profiles. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3574. doi:10.1158/1538-7445.AM2011-3574

7297 Background: Adjuvant chemotherapy treatment for early stage NSCLC patients is not yet standard practice. The aim of the present trial is to compare the activity, safety, and quality of life ef...

Cattle were successively infested for 4 years with larval cattle grubs, Hypoderma lineatum, to demonstrate the acquisition of resistance. The effects of host age and dietary-induced state with Vitamin A on susceptibility to infestation and their interactions with effects from previous infestations were also determined. Cattle acquired resistance to infestation after a single infestation. This resistance was not affected by host age for at least 4 years, was not affected by a deficiency of vitamin A, and was effective in the skin and connective tissues of the host. The effects of this acquired resistance were highly variable in degree, were produced primarily during the first 90 days of infestation and increased after repeated provocation to provide nearly complete protection in some animals. Calves and yearlings had innate resistance that decreased with age, was localized in the skin, was impaired by a deficiency of Vitamin A, and resulted in a mean loss of 65–75% of the larvae in an infestation dose of up to 150. The combined effects of the 2 types of resistance reduced the grub-burden in cattle throughout their life.

The purpose of this study was to employ the Salmonella /microsomal assay (Ames test) to investigate the mutagenic potential of a thermostable exotoxin of Bacillus thuringiensis subsp. morrisoni . Bacteria are ideal for the detection of infrequently occurring point mutations because the large number of organisms (200 to 400 million bacteria per plate) exposed to the mutagen at any one time increases the possibility of observing a random mutational event. The exotoxin used in this study was produced using the shaker flask fermentation procedure with mineral casein broth. A Petri dish method of bioassay using fresh bovine feces was used to determine the efficacy of the exotoxin against horn flies. The LD 50 was found to be 5.35 μl/g of feces. Five bacterial tester strains were identified and characterized for the genetic markers described by Ames et al. (B. N. Ames et al., 1975, Mutat. Res. , 31 , 347–364). Appropriate doses of the B. thuringiensis supernatant, solvent or positive control were added to agar plates. The supernatant was tested at five dose levels against all five strains of bacteria. Controls of bacteria only were included for spontaneous reversions. All treatments were performed in triplicate. The numbers of revertant colonies from each set of triplicate plates were averaged and the standard deviation calculated and compared to that found with the solvent control. The negative controls, positive controls, and sterility controls all fulfilled requirements for determination of a valid test. No detectable mutagenic activity was found for the thermostable exotoxin of B. thuringiensis morrisoni .

Old World rodents Gerbillus gerbillus and Mus musculus and New World mice Peromyscus leucopus and P. maniculatus were susceptible hosts to larvae of the rodent bot fly Cuterebra fontinella . There were no differences because of sex in the susceptibility of previously uninfested (Pu) P. leucopus , the natural host of C. fontinella. P. leucopus acquired a partial resistance 5 weeks after infestation, whereby the rate dropped from >80% among Pu mice to ca 50% in previously infested (Pi) mice. Mice were sensitized by larvae that entered naturally via the nares or anus, but not when introduced through the eye or by subcutaneous injection in the back. The level of resistance acquired was not related to the number of larvae in an exposure or number of exposures, but more than 1 larva was required to provoke a response in Pi mice. Mice in which the infestation was aborted after 2 days (larvae had not completed migration) were less resistant to reinfestation than mice that underwent a mature infestation.

Procedures are described for bioassaying fermentation products of various varieties of Bacillus thuringiensis against adults of the Mediterranean fruit fly, Ceratitis capitata (Wied.). The procedures were designed to discriminate various types of active agents on the basis of their water solubility and heat (120°C) stability. Products typical for δ-endotoxin and/or spores and exotoxin of the bacterium were found that were pathogenic for the flies. Evidence of heterogeneity in spectrum of activity among the heat stable exotoxins is presented. Zusammenfassung Erfolgreiche Behandlung adulter Mittelmeerfruchtfliegen, Ceratitis capitata (Wied.) mit Bacillus thuringiensis Verfahren zur biologischen Untersuchung von Garungsprodukten verschiedener Arten des Bacillus thuringiensis gegen erwachsene Mittelmeerfruchtfliegen, Ceratitis capitata, werden beschrieben. Die Verfahren wurden darauf abgestimmt, verschiedene Arten aktiver Agenzien aufgrund ihrer Wasserloslichkeit und Hitzebestandigkeit (120°C) zu unterscheiden. Produkte, typisch fur δ-Endotoxin und/oder Sporen und Exotoxin des Bakteriums wurden gefunden, welche fur die Fliegen pathogen waren. Ein Beweis der Ungleichartigkeit im Spektrum der Aktivitat unter den hitzebestandigen Exotoxinen wird vorgelegt.

Female Glossina palpalis palpalis (R.-D.) produced larger puparia when they fed on live goats that were injected intravenously with 200 IU of sodium heparinate/day than when they fed on untreated goats or on heparinised goat blood in vitro. Heparin did not produce the same effects when guineapigs were the hosts. Puparia from flies that fed on untreated guineapigs were larger than those from flies that fed on untreated goats. Heparin had no effect on the life-span or fecundity of females that fed on goats or on the life-span of flies that fed on guineapigs. However, the fecundity of flies that fed on guineapigs injected with 500 IU heparin/kg was greater than that of flies fed on untreated guineapigs.

First-instar larvae of the common cattle grub, Hypoderma lineatum , implanted in the backs of laboratory white mice usually migrated to the thoracic and abdominal cavities where they were encapsulated by fibrous tissues of the host. These larvae did not grow but some survived at least 10 months. Mice died as a consequence of myiasis only during the first 3 weeks after the implantation. Apparently, migrating larvae frequently caused lethal lesions in the host's vital organs.

White mice fed a vitamin A-deficient diet for 30 days were more susceptible to percutaneous infestation by larvae of Hypodenna lineatum than mice fed complete, pyridoxine-deficient, low-protein (6%), or gelatin-mucin-supplemented diets. Also, the rate of survival of larvae was higher in mice injected twice with 0.5 ml of rabbit antimouse lymphocyte serum and treated with whole-body irradiation (400 rad) than in untreated mice. The largest larvae found in mice fed on the granulomatous tissues of the host surrounding them, and their digestive tracts appeared normal; the midgut epithelium of smaller larvae appeared to be nonfunctional.

When white mice were exposed to infestation by (1) transplanting 1st-stage, 2- to 4-month-old larvae of Hypoderma lineatum (de Villers) from the esophagus of cattle to subdermal sites in mice or (2) by allowing female flies to lay fertile eggs on the hairs of mice, the larvae migrated to the thoracic or abdominal cavity of the host mice where the survival and growth of the larvae were enhanced by injections of rabbit antimouse lymphocyte serum to the mice. Also, in mice so treated, the midgut of larvae appeared morphologically normal; in untreated mice, the midgut epithelium appeared abnormal. The extent of coverage and the cellular composition of host capsular tissue adhering to larvae did not seem to be related to survival or growth of larvae.

For rearing larvae of the screw-worm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), a synthetic medium was developed that contained casein, yeast extract, cholesterol, inorganic salts, water, and agar. This medium was further defined by replacement of casein with a mixture of L-isomer amino acids, and of yeast extract with a mixture of vitamins and ribonucleic acid. Larval growth and development on the defined medium were nearly equal to those on media containing casein and yeast. Further studies on individual requirements showed that larvae absolutely required thiamine, riboflavin, pantothenate, niacin, and choline for growth; that biotin and folic acid stimulated growth and were necessary for maturation to the adult stage; and that pyridoxine (and its analogs pyridoxal and pyridoxamine), inositol, B12, and carnitine had no effect on growth. Niacinamide replaced niacin, but p -aminobenzoic acid had no effect on the folic acid requirement. Larvae failed to grow in the absence of arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, threonine, tryptophane, and valine. Cystine and glycine were required for normal growth. Ornithine or citrulline could not be substituted for arginine, homocystine or cysteine for methionine, nor hydroxy-proline for proline. The larva requirement for cholesterol could not be satisfied by dihydroxycholesterol, ergesterol, or β-sitosterol. Addition of corn, safflower, or cod liver oils inhibited growth, possibly by mechanical stresses. Choline was replaced by lecithin, but not by betaine, ethanolamine, or carnitine. Ribose, glucose, and maltose added to the diet inhibited growth, but glycogen and starch at ½% levels did not. The inhibition from saccharides of low molecular weight appeared to result from osmotic stresses. RNA was essential for larval growth, but could be replaced by a mixture of adenine, cytosine, and guanine. Uracil and uradylic acid inhibited growth.

A procedure is described for detecting the systemic activity of insecticides against 1st-stage larvae of Cuterebra sp. in laboratory white mice. Exposure of male mice to larvae on Day 0, oral treatment with insecticides on Day 2, and examination on Day 7 for larvae that formed breathing holes in the skin was the most sensitive technique for determining the activity of famphur, crufomate, trichlorfon, and ronnel (LD50values for larvae were 1.46, 19.59, 20.91, and 29.92 mg/kg body weight of host, respectively). The acute oral LD50 of coumaphos for male host mice was so near the LD50 for the larvae that systemic activity of coumaphos could not be conclusively tested. These findings agree with the relative effectiveness of the same insecticides against larvae of the common cattle grub, Hypoderma linealum (de Villers), in cattle. The mouse-cuterebrid host-parasite system for screening systemic insecticides against oestrid larvae has the potential of providing more definitive toxicological data at lower costs than other existing systems.

The mean levels of vitamin A in the serum of 6-month-old Hereford calves fed complete or vitamin A-deficient diets for 85 days were 51.6 and 14.0 μ/100 ml, respectively. The animals deficient in vitamin A were more susceptible than normal animals to infestation by larvae of Hypoderma lineatum that hatched from eggs laid on the hair (39.7 vs 21.2% recovery of larvae) but not to infestation by similar numbers of newly hatched larvae injected subcutaneously (57.9 vs 52.7% recovery of larvae). Avitaminosis A apparently reduced the resistance of calves to percutaneous invasions by the parasites.

The humoral and cellular immune responses of previously infested and noninfested cattle were compared after a single experimental exposure to 1st-instar Hypoderma lineatum. No correlation was found between the development of humoral antibodies as measured by passive hemagglutination assay and resistance in cattle. However, the most resistant cattle had higher macrophage migration-inhibition activity before and 1 month after infestation than did low- or non-resistant animals, and resistant animals also had greater sensitivity to antigens from larvae as they penetrated the skin. These results suggest that acquired resistance to hypodermatosis involves a cellular component of the immune mechanism.

The immunologic relationship of ocular, cutaneous and renal glomerular antigens has been demonstrated by a number of investigators. The earlier distribution studies (1-3) using antibody against renal glomerular antigen showed the probable localization of immunologically similar antigen in the basement membranes of many organs including skin and eye. These in vitro experiments were recently confirmed and extended in vivo by Nozaki et al (4) who showed that fluorescein-conjugated anti-rat-glomerular antibody reacts specifically with rat glomeruli, corneal basement membrane, lens capsule, and small blood vessels in the choroid, optic nerve, and conjunctiva.

Two levels of 3 factors, (1) host age, (2) host dietary state in regard to vitamin A, and (3) previous infestation history, were tested individually and in combinations for their effects on the susceptibility of Peromyscus leucopus to infestation by larvae of the rodent bot fly, Cuterebra fontinella. Previous infestation was the only significant single factor. Previously uninfested (Pu) mice usually were more susceptible to infestation than previously infested (Pi) mice. Interactions of age and state of vitamin A had the following effects: 1) Young Pu mice that had been denied vitamin A were much less susceptible to infestation than equivalent mice that had been fed diets containing the vitamin; and 2) when Pu mice were deficient in vitamin A, old mice were more suscep- tible than young mice but when Pu mice were not deficient in the vitamin, young mice were more susceptible. These findings may have significance for natural infestations of P. leucopus.

Larvae of the rodent botfly, Cuterebra fontinella, follow a consistent migration route through their natural host, the white-footed mouse, Peromyscus leucopus. Larvae that enter the eye or nares spend about 48 hr in the nasal cavity and then follow a caudally oriented path that leads through the nasal passage, trachea, thoracic and abdominal cavities, and ends in the subcutaneous tissues of the postero- ventral abdominal region. Larvae that enter mice through the anus or by injection into the subcutaneous tissues of the back begin their migration from the trachea and from that point follow the usual path to the terminus.

Introduction Janus kinase 2 (JAK2) is involved in the downstream activation of signal transducer and activator of transcription 3 (STAT3) and STAT5 and is responsible for transducing signals for several proinflammatory cytokines involved in the pathogenesis of rheumatoid arthritis (RA), including interleukin (IL)-6, interferon γ (IFNγ) and IL-12. In this paper, we describe the efficacy profile of CEP-33779, a highly selective, orally active, small-molecule inhibitor of JAK2 evaluated in two mouse models of RA. Methods Collagen antibody-induced arthritis (CAIA) and collagen type II (CII)-induced arthritis (CIA) were established before the oral administration of a small-molecule JAK2 inhibitor, CEP-33779, twice daily at 10 mg/kg, 30 mg/kg, 55 mg/kg or 100 mg/kg over a period of 4 to 8 weeks. Results Pharmacodynamic inhibition of JAK2 reduced mean paw edema and clinical scores in both CIA and CAIA models of arthritis. Reduction in paw cytokines (IL-12, IFNγ and tumor necrosis factor α) and serum cytokines (IL-12 and IL-2) correlated with reduced spleen CII-specific T helper 1 cell frequencies as measured by ex vivo IFNγ enzyme-linked immunosorbent spot assay. Both models demonstrated histological evidence of disease amelioration upon treatment (for example, reduced matrix erosion, subchondral osteolysis, pannus formation and synovial inflammation) and reduced paw phosphorylated STAT3 levels. No changes in body weight or serum anti-CII autoantibody titers were observed in either RA model. Conclusions This study demonstrates the utility of using a potent and highly selective, orally bioavailable JAK2 inhibitor for the treatment of RA. Using a selective inhibitor of JAK2 rather than pan-JAK inhibitors avoids the potential complication of immunosuppression while targeting critical signaling pathways involved in autoimmune disease progression.