Effects of orthochlorobenzalmalononitrile on horses used in Public Security

ABSTRACT The effects on human beings of tear gas (CS) used by police forces during the control of civil disturbances are widely known and amply described in numerous scientific papers. However, the advent of the concepts of animal welfare raises the question of whether animals exposed to CS in such events, specifically horses, would suffer the same effects as those described for humans. The purpose of this study was to determine whether mounted police horses exposed to CS exhibit the same symptoms as humans. In this study, 12 horses of the Military Police of Paraná, healthy and with no history of respiratory tract disorders, were led through a gas cloud caused by the detonation of six teargas grenades. The horses’ physiological parameters of respiratory rate, heart rate, rectal temperature, and color of the eye mucosa were evaluated 24 hours before exposure, 30 min, and 24 hours after exposure. Blood samples were collected for complete blood count (CBC) and blood gas analysis and samples of eye mucosa were obtained using sterile swabs. The analysis of these parameters did not reveal effects analogous to those described in humans.

Idiopathic seasonal alopecia in horse: case report

ABSTRACT This report describes the first case of idiopathic seasonal alopecia in a horse in Brazil. The disease is of unknown etiology, characterized by alopecic processes in the thoracic and lateral abdominal regions, in a bilaterally symmetrical way. An eight-year-old male grade horse was treated presenting hair loss in a bilaterally symmetrical manner in the arm and abdomen areas, without any other associated clinical signs. The areas with alopecia showed no pruritus, inflammation or scaling. On the epidermis, the histological evaluation presented irregular hyperplasia, hyperpigmentation, compact orthokeratosis, edema and an inflammatory infiltrate. The hair follicles were active and containing hair shaft. The case was monitored with photographic records for two consecutive years (2012 to 2014), in which the hair fall occurred at the end of autumn with spontaneous hair growth in the middle of the summer. The diagnosis was based on the history, histopathology and photographic follow-up performed. Although mentioned in the literature, this is the first clinical and pathological description of such disorder affecting an equine in Brazil.

Stephanofilariasis in beef cattle - case report

ABSTRACT Stephanofilariasis is an ulcerative dermatitis caused by nematodes that affect cattle in several countries in the world. However, it has not been described in beef cattle in Brazil. The objective of this study is to describe three cases of stephanofilariasis, which occurred in beef cows in the municipality of Ipê, RS, Brazil. The disease was characterized by pruritic, ulcerated and crusty seasonal lesions present in the cranial region of the udder. The diagnosis was confirmed by analyses of secretions stained smears and by direct optical microscopic examination of the sediment and the treatment was effectively carried out with topical trichlorphon. This report indicates that stephanofilariasis should be included as a differential diagnosis for dermatopathies in beef cattle in Brazil.

Serum proteinogram of the Campeiro horse

ABSTRACT The aim of this study to measure the fractions of the total serum proteins of the Campeiro horse and identify the influences of biological variants. Blood samples were taken in 138 horses of the breed Campeiro for measuring the concentration of total serum protein by the biuret method. Serum concentrations of protein fractions were measured by electrophoresis using agarose gel. Groups were formed according to age, sex and reproductive condition. The average values of serum fractions: albumin (2.85±0.36g/dl), alpha 1 (0.28±0.11g/dl), alpha 2 (0.26±0.08g/dL) beta 1 (0.57±0.15g/dl), beta 2 (0.89±0.28g/dL), gamaglobulinas (1.86±0.34g/dL), albumin/globulin ratio (0.75±0.18) and 2.5% percentile and 97.5% had slight differences in relation to the reference interval proposed for the species. They observed higher values of alpha 1 and 2 globulins in the group from that had six to eight years old and gammaglobulins in group above 13 years old. Serum protein concentrations were similar in horses and mares and between non-pregnant and pregnant. Sex and pregnancy status did not affect serum proteinogram. Alpha and gammaglobulins have higher values as the age increases. Serum proteinogram of Campeiro horses shows variations that have to be considered in the interpretation of laboratory tests.

Systemic toxic reaction due to multiple honeybee stings in equine: Case report

ABSTRACT Accidents caused by insects of the Hymenoptera are rarely described in large animals. The attacks caused by honeybee (Apis mellifera) may cause severe consequences and its intensity changes according to the number of stings. Local and systemic reactions can occur, including progression to death. This report describes a case of honeybee attack on an equine, which took place in the city of Lages, in the state of Santa Catarina, Brazil. In the clinical assessment the horse showed apathy, anorexia, head and pectoral edemas, dyspnea, icteric mucosa, increased mandibular lymph nodes and darkened urine. The blood count showed anemia and serum biochemical tests suggested, muscular and hepatic lesions. The urinalysis test indicated hemoglobinuria and increased clotting time. Treatment included lactate Ringer’s solution fluid therapy, furosemide, promethazine, corticosteroids and 20% mannitol solution. Hot and cold compresses were applied alternately on areas with edema. There was a satisfactory response to treatment and the animal was discharged after 30 days in veterinary hospital. The description of honeybee sting accidents in large animals is important because of the evolution that can lead to death. The early approach associated with appropriate treatment, avoiding the worsening of the lesions is fundamental for the recovery of the patient.

Chronic renal failure in equine due to ascending pyelonephritis predisposed by cauda equina syndrome: case report

ABSTRACT This report describes the case of a mare, of the Campeiro breed, used as an embryo donor, which had recurrent cystitis and urinary incontinence crisis. Clinical signs evolved to progressive weight loss, anorexia, apathy, and isolation from the group. Physical examination showed tail hypotonia, perineal hypalgesia, rectal and bladder sagging compatible with signs related to cauda equina syndrome. Complementary laboratory and sonographic assessment, and necropsy confirmed the diagnosis of chronic renal failure (CRF), which was attributed to the ascending pyelonephritis. The examination of urine culture showed growth of bacteria of the genus Streptococcus sp. This is a rare case in the equine species where the lower motor neuron dysfunction led the development of infectious process in the urinary tract, progressing to renal chronic condition incompatible with life.

Estudo anatômico, ultrassonográfico e tomográfico do aparato podotroclear de equinos adultos

RESUMO A síndrome do navicular é uma condição que envolve o aparato podotroclear e representa uma das causas mais comuns de claudicação dos membros torácicos de equinos. Portanto, o estudo complementar da região reveste-se de grande interesse quando se refere ao diagnóstico e tratamento das claudicações dos equinos. O objetivo deste estudo foi demonstrar as diferenças dos achados imagenológicos entre a ultrassonografia e a tomografia computadorizada na avaliação das estruturas palmares do aparato podotroclear de equinos adultos e hígidos, bem como a descrição das estruturas observadas nas imagens obtidas com essas técnicas. Para isso, foram realizadas imagens de quatro peças anatômicas, as quais foram posteriormente seccionadas e utilizadas para a descrição anatômica. A utilização de peças anatômicas auxilia no conhecimento da anatomia normal, o que leva à melhor interpretação das imagens e aumenta a especificidade diagnóstica na detecção das alterações que as doenças acarretam. A ultrassonografia fornece informações relevantes quanto às estruturas estudadas, e sua associação com a tomografia computadorizada aumentou a acurácia da investigação. Apesar de o uso da tomografia computadorizada ser mais indicada para tecido ósseo, ela fornece informações importantes, podendo ser usada como uma ferramenta útil quando não se tem disponível a ressonância magnética em razão do custo ou da disponibilidade.

Perfil bioquímico sérico de equinos clinicamente sadios da raça Campeiro

RESUMO Amostras de sangue foram obtidas de 138 equinos registrados da raça Campeiro, com idade média de 9,7±5,4 anos, sendo 14 machos (10,15%) e 124 fêmeas (89,85%). Observaram-se valores médios da atividade sérica de GGT: 13,73±4,08 U/L; AST: 246,34±72,87U/L; ALT: 5,13±1,18U/L; FA: 284,32±53,33UI/L; CK: 132,54±72,25U/L; LDH: 511,38±143,65U/L; e das concentrações séricas de ureia: 38,65±12,62mg/dL e de creatinina: 1,24±0,24mg/dL. Os valores médios de AST, FA, ALT, ureia e creatinina foram semelhantes aos propostos na literatura para outras raças. Os valores de CK, GGT e LDH foram superiores aos comumente utilizados como referências. Não houve diferença nas concentrações de nenhum dos componentes séricos avaliados nas diferentes idades analisadas. Maiores valores médios nas concentrações de ureia e menores de creatinina foram observados nas fêmeas em relação aos machos, assim como a maior atividade sérica de FA em fêmeas gestantes em relação às éguas vazias. O perfil bioquímico sérico de equinos sadios da raça Campeiro apresenta variações peculiares que devem ser levadas em consideração na interpretação de exames laboratoriais.

Proteolytic degradation of neuropeptide Y (NPY) from head to toe: Identification of novel NPY-cleaving peptidases and potential drug interactions in CNS and Periphery

The bioactivity of neuropeptide Y (NPY) is either N-terminally modulated with respect to receptor selectivity by dipeptidyl peptidase 4 (DP4)-like enzymes or proteolytic degraded by neprilysin or meprins, thereby abrogating signal transduction. However, neither the subcellular nor the compartmental differentiation of these regulatory mechanisms is fully understood. Using mass spectrometry, selective inhibitors and histochemistry, studies across various cell types, body fluids, and tissues revealed that most frequently DP4-like enzymes, aminopeptidases P, secreted meprin-A (Mep-A), and cathepsin D (CTSD) rapidly hydrolyze NPY, depending on the cell type and tissue under study. Novel degradation of NPY by cathepsins B, D, L, G, S, and tissue kallikrein could also be identified. The expression of DP4, CTSD, and Mep-A at the median eminence indicates that the bioactivity of NPY is regulated by peptidases at the interphase between the periphery and the CNS. Detailed ex vivo studies on human sera and CSF samples recognized CTSD as the major NPY-cleaving enzyme in the CSF, whereas an additional C-terminal truncation by angiotensin-converting enzyme could be detected in serum. The latter finding hints to potential drug interaction between antidiabetic DP4 inhibitors and anti-hypertensive angiotensin-converting enzyme inhibitors, while it ablates suspected hypertensive side effects of only antidiabetic DP4-inhibitors application. The bioactivity of neuropeptide Y (NPY) is either N-terminally modulated with respect to receptor selectivity by dipeptidyl peptidase 4 (DP4)-like enzymes or proteolytic degraded by neprilysin or meprins, thereby abrogating signal transduction. However, neither the subcellular nor the compartmental differentiation of these regulatory mechanisms is fully understood. Using mass spectrometry, selective inhibitors and histochemistry, studies across various cell types, body fluids, and tissues revealed that most frequently DP4-like enzymes, aminopeptidases P, secreted meprin-A (Mep-A), and cathepsin D (CTSD) rapidly hydrolyze NPY, depending on the cell type and tissue under study. Novel degradation of NPY by cathepsins B, D, L, G, S, and tissue kallikrein could also be identified. The expression of DP4, CTSD, and Mep-A at the median eminence indicates that the bioactivity of NPY is regulated by peptidases at the interphase between the periphery and the CNS. Detailed ex vivo studies on human sera and CSF samples recognized CTSD as the major NPY-cleaving enzyme in the CSF, whereas an additional C-terminal truncation by angiotensin-converting enzyme could be detected in serum. The latter finding hints to potential drug interaction between antidiabetic DP4 inhibitors and anti-hypertensive angiotensin-converting enzyme inhibitors, while it ablates suspected hypertensive side effects of only antidiabetic DP4-inhibitors application.

Avaliação morfométrica de equinos do Esquadrão de Polícia Montada dos municípios de Lages, Joinville e Florianópolis-SC

RESUMOO objetivo do presente trabalho foi avaliar as características morfométricas de equinos utilizados no patrulhamento ostensivo pertencentes aos Esquadrões de Polícia Montada localizados nos municípios de Lages, Joinville e Florianópolis - SC. Foram utilizados 101 animais (78 machos castrados, um garanhão e 22 fêmeas), com idade média de 11,9 anos e massa corpórea de 490,82±53,51kg. Foram tomadas 20 medidas lineares individuais, por meio das quais foram determinados 13 índices zootécnicos. Os dados foram avaliados segundo análise descritiva, e a comparação simples entre médias pelo teste t de Student (P<0,05). Houve diferença significativa entre machos e fêmeas com relação ao comprimento de garupa, largura da anca, perímetro da canela e IDT nos animais pertencentes ao Esquadrão de Florianópolis. Conclui-se que os equinos dos três Esquadrões avaliados são, em geral, animais baixos de frente, "longe de terra", eumétricos e longilíneos, e classificados entre animais de tração ligeira e de tração pesada.

Effects of dipeptidyl peptidase-4 inhibition in an animal model of experimental asthma: a matter of dose, route, and time

The CD26-associated enzymatic activity of dipeptidyl peptidase-4 (DPP4) as well as the recruitment of CD26(+) T cells increase under allergic airway inflammation. Furthermore, genetic deficiency of CD26/DPP4 exerts protective effects in experimental asthma. Therefore, CD26/DPP4 might represent a novel therapeutic target in asthma. To study the effects of pharmacological inhibition of DPP4 on allergic airway inflammation the DPP4-inhibitor isoleucine thiazolidide was tested using different doses at different time points (at sensitization, immediately before and simultaneously with the allergen challenge, as well as continuously via drinking water), and different routes (intraperitoneal, oral, and by inhalation). Allergic-like airway inflammation was induced in Fischer 344 rats (Charles River) sensitized against ovalbumin (OVA) using OVA aerosols. Intraperitoneal application of the DPP4 inhibitor showed effects neither at sensitization nor at challenge, whereas a continuous application via drinking water using high doses of the inhibitor led to an aggravation of the histomorphological signs of airway inflammation. In contrast, aerosolization of the DPP4 inhibitor simultaneously with the allergen significantly reduced airway hyperresponsiveness and ameliorated histopathological signs compared to controls. In addition, this treatment resulted in increased mRNA levels of surfactant proteins, suggesting an involvement of DPP4 inhibitors in surfactant metabolism in OVA-challenged rats. Continuous systemic inhibition of DPP4 via the oral route aggravates allergic airway inflammation. In contrast, topical inhibition of DPP4 exerts potential protective effects, and further research in humans is needed.

Reduced airway inflammation in CD26/DPP4-deficient F344 rats is associated with altered recruitment patterns of regulatory T cells and expression of pulmonary surfactant proteins

INTRODUCTION

CD26 is highly expressed on lung epithelial cells as well as on immune cells. Ovalbumin (OVA)-induced airway inflammation induces a further increase of CD26 expression. CD26-deficient rat strains exhibit blunted clinical courses in models of experimental asthma.

OBJECTIVE

(1) To investigate the involvement of regulatory T cells (Tregs) and the surfactant system in a rat model of genetic CD26 deficiency. (2) To investigate regulatory mechanisms dependent on the endogenous CD26 expression. (3) To investigate the impact of CD26 on surfactant protein (SP)-levels under inflammatory conditions.

METHODS

Wild-type and CD26-deficient F344 rats were sensitized to and challenged with OVA. Subsequently, airway inflammation, SP levels as well as surface tension of the bronchoalveolar lavage (BAL) fluid were evaluated.

RESULTS

CD26 deficiency led to decreased airway inflammation, e.g. reduced numbers of eosinophils and activated T cells in the BAL. Remarkably, the CD26-deficient rats exhibited a significantly increased influx of FoxP3(+) Tregs into the lungs and increased IL-10-secretion/production by draining lymph node cells in culture experiments. Furthermore, in OVA-challenged CD26-deficient rats, the increase of the expression of the collectins SP-A and SP-D as well as of the surface tension-active SP-B was significantly less pronounced than in the CD26-positive strain. Only in the wild-type rats, functional alterations of the surfactant system, e.g. the increased surface tension were obvious after OVA challenge.

CONCLUSION

Reduced airway inflammation in CD26-deficient F344 rats appear to be mediated by differences in the recruitment and activity of Tregs. This altered inflammation is associated with differences in the SP expression as well as function.

Generation of anti-TLR2 intrabody mediating inhibition of macrophage surface TLR2 expression and TLR2-driven cell activation

Background

Toll-like receptor (TLR) 2 is a component of the innate immune system and senses specific pathogen associated molecular patterns (PAMPs) of both microbial and viral origin. Cell activation via TLR2 and other pattern recognition receptors (PRRs) contributes to sepsis pathology and chronic inflammation both relying on overamplification of an immune response. Intracellular antibodies expressed and retained inside the endoplasmatic reticulum (ER-intrabodies) are applied to block translocation of secreted and cell surface molecules from the ER to the cell surface resulting in functional inhibition of the target protein. Here we describe generation and application of a functional anti-TLR2 ER intrabody (αT2ib) which was generated from an antagonistic monoclonal antibody (mAb) towards human and murine TLR2 (T2.5) to inhibit the function of TLR2. αT2ib is a scFv fragment comprising the variable domain of the heavy chain and the variable domain of the light chain of mAb T2.5 linked together by a synthetic (Gly₄Ser)₃ amino acid sequence.

Results

Coexpression of αT2ib and mouse TLR2 in HEK293 cells led to efficient retention and accumulation of TLR2 inside the ER compartment. Co-immunoprecipitation of human TLR2 with αT2ib indicated interaction of αT2ib with its cognate antigen within cells. αT2ib inhibited NF-κB driven reporter gene activation via TLR2 but not through TLR3, TLR4, or TLR9 if coexpressed in HEK293 cells. Co-transfection of human TLR2 with increasing amounts of the expression plasmid encoding αT2ib into HEK293 cells demonstrated high efficiency of the TLR2-αT2ib interaction. The αT2ib open reading frame was integrated into an adenoviral cosmid vector for production of recombinant adenovirus (AdV)-αT2ib. Transduction with AdVαT2ib specifically inhibited TLR2 surface expression of murine RAW264.7 and primary macrophages derived from bone marrow (BMM). Furthermore, TLR2 activation dependent TNFα mRNA accumulation, as well as TNFα translation and release by macrophages were largely abrogated upon transduction of αT2ib. αT2ib was expressed in BMM and splenocytes over 6 days upon systemic infection with AdVαT2ib. Systemic transduction applying AdVαT2ib rendered immune cells largely non-responsive to tripalmitoyl-peptide challenge. Our results show persistent paralysis of TLR2 activity and thus inhibition of immune activation.

Conclusion

The generated anti-TLR2 scFv intrabody inhibits specifically and very efficiently TLR2 ligand-driven cell activation in vitro and ex vivo. This indicates a therapeutic potential of αT2ib in microbial or viral infections.

Airway-specific recruitment of T cells is reduced in a CD26-deficient F344 rat substrain

Asthma is a chronic inflammatory disease affecting the airways. Increased levels of T cells are found in the lungs after the induction of an allergic-like inflammation in rats, and flow cytometry studies have shown that these levels are reduced in CD26-deficient rats. However, the precise anatomical sites where these newly recruited T cells appear primarily are unknown. Therefore, we quantified the distribution of T cells in lung parenchyma as well as in large, medium and small airways using immunohistochemical stainings combined with morphometric analyses. The number of T cells increased after the induction of an allergic-like inflammation. However, the differences between CD26-deficient and wild-type rats were not attributable to different cell numbers in the lung parenchyma, but the medium- and large-sized bronchi revealed significantly fewer T cells in CD26-deficient rats. These sites of T cell recruitment were screened further using immunohistochemistry and quantitative real-time polymerase chain reaction with regard to two hypotheses: (i) involvement of the nervous system or (ii) expression of chemokines with properties of a T cell attractor. No topographical association was found between nerves and T cells, but a differential transcription of chemokines was revealed in bronchi and parenchyma. Thus, the site-specific recruitment of T cells appears to be a process mediated by chemokines rather than nerve-T cell interactions. In conclusion, this is the first report showing a differential site-specific recruitment of T cells to the bronchi in a CD26-deficient rat substrain during an asthma-like inflammation.

Phenotyping of congenic dipeptidyl peptidase 4 (DP4) deficient Dark Agouti (DA) rats suggests involvement of DP4 in neuro-, endocrine, and immune functions

BACKGROUND

Treatment of diabetes type 2 using chronic pharmacological inhibition of dipeptidyl peptidase 4 (DP4) still requires an in-depth analysis of models for chronic DP4 deficiency, because adverse reactions induced by some DP4 inhibitors have been described.

METHODS

In the present study, a novel congenic rat model of DP4 deficiency on a "DP4-high" DA rat genetic background was generated (DA.F344-Dpp4(m)/ SvH rats) and comprehensively phenotyped.

RESULTS

Similar to chronic pharmacological inhibition of DP4, DP4 deficient rats exhibited a phenotype involving reduced diet-induced body weight gain and improved glucose tolerance associated with increased levels of glucagon-like peptide-1 (GLP-1) and bound leptin as well as decreased aminotransferases and triglycerides. Additionally, DA.F344-Dpp4(m)/SvH rats showed anxiolytic-like and reduced stress-like responses, a phenomenon presently not targeted by DP4 inhibitors. However, several immune alterations, such as differential leukocyte subset composition at baseline, blunted natural killer cell and T-cell functions, and altered cytokine levels were observed.

CONCLUSIONS

While this animal model confirms a critical role of DP4 in GLP-1-dependent glucose regulation, genetically induced chronic DP4 deficiency apparently also affects stress-regulatory and immuneregulatory systems, indicating that the use of chronic DP4 inhibitors might have the potential to interfere with central nervous system and immune functions in vivo.

Transferred T cells preferentially adhere in the BALT of CD26-deficient recipient lungs during asthma

The multifunctional glycoprotein CD26/dipeptidyl peptidase 4 (DP4) has a DP activity, plays a role during T-cell activation, and interacts with several proteins, including extracellular matrix (ECM)-proteins. The latter have been studied mainly in the context of experimental metastasis. The potential role of CD26 for T-cell adhesion could be of major interest. Here, a coisogenic transfer of CFSE-labelled T cells was performed after isolation from CD26-expressing or CD26-deficient F344 rat donors and subsequent cross-transfer to recipients of the other substrain. Their recovery in the lungs was quantified using flow cytometry, a histochemical activity assay, as well as immunohistochemistry and morphometry. Under naïve conditions there were neither differences in the numbers of recovered T cells nor in their preferential anatomical sites of adhesion. The induction of an asthma-like inflammation, however, led to a site-preferential adhesion of T cells in the bronchus-associated lymphatic tissue (BALT). In this compartment of the lungs, surprisingly, significantly more T cells were found in CD26-deficient recipient lungs, regardless of the origin of the transferred T cells. These findings demonstrate a negative regulatory role of the BALT-specific expression of CD26 in T-cell adhesion during an asthma-like inflammation. Considering the pattern of cellular re-distribution it is not very likely that CD26 expressed on T cells and/or endothelial cells represents a significant factor in T-cell adhesion in vivo. Instead, the present findings suggest that the lack of the CD26 peptidase function in BALT might cause an overflow of a T-cell chemoattractant, which yet remains to be identified.

CD26/dipeptidyl peptidase 4-deficiency alters thymic emigration patterns and leukcocyte subsets in F344-rats age-dependently

As CD26 (dipeptidyl peptidase 4/DPP4) rapidly truncates incretins N-terminally, including glucagon-like peptide-1, DPP4-inhibitors have been developed for treatment of diabetes type 2. To some extent this is surprising, as CD26/DPP4 is also deeply involved in immune regulation. Long-term pharmacological studies are hampered by off-target inhibition of DPP4-homologues. Therefore, we studied the effects of genetic CD26/DPP4-deficiency by investigating blood, spleen and thymus leucocyte subpopulations of wild-type and CD26-deficient F344-rats at different ages. In young animals at 1 and 3 months of age, there were no differences in leucocyte subsets, while in older animals the T cell composition was changed significantly. From the age of 6 months onwards, reduced numbers of recent thymic emigrants and memory T cells, and consequently an increased amount of naive T cells were observed in CD26-deficient rats. In addition, the architecture of the thymus was altered, as observed by a reduced density of lymphocytes in the medulla. Furthermore, the number of proliferating cells in the thymus was decreased in CD26-deficient rats at a higher age. Moreover, CD26-deficiency resulted in markedly reduced numbers of B cells in later life. Additionally, an age- but not CD26-dependent increase of regulatory T cells and a decrease of natural killer cell numbers were detected in the blood and spleen. Our findings indicate an important role of CD26 in maintaining lymphocyte composition, memory T cell generation and thymic emigration patterns during immunosenescence, with possible implications for using DPP4-inhibitors.

Inhibition of CD26/dipeptidyl peptidase IV enhances CCL11/eotaxin-mediated recruitment of eosinophils in vivo

Chemokines mediate the recruitment of leukocytes to the sites of inflammation. N-terminal truncation of chemokines by the protease dipeptidyl peptidase IV (DPPIV) potentially restricts their activity during inflammatory processes such as allergic reactions, but direct evidence in vivo is very rare. After demonstrating that N-terminal truncation of the chemokine CCL11/eotaxin by DPPIV results in a loss of CCR3-mediated intracellular calcium mobilization and CCR3 internalization in human eosinophils, we focused on the in vivo role of CCL11 and provide direct evidence for specific kinetic and rate-determining effects by DPPIV-like enzymatic activity on CCL11-mediated responses of eosinophils. Namely, it is demonstrated that i.v. administration of CCL11 in wild-type F344 rats leads to mobilization of eosinophils into the blood, peaking at 30 min. This mobilization is significantly increased in DPPIV-deficient F344 rats. Intradermal administration of CCL11 is followed by a dose-dependent recruitment of eosinophils into the skin and is significantly more effective in DPPIV-deficient F344 mutants as well as after pharmacological inhibition of DPPIV. Interestingly, CCL11 application leads to an up-regulation of DPPIV, which is not associated with negative feedback inhibition via DPPIV-cleaved CCL11((3-74)). These findings demonstrate regulatory effects of DPPIV for the recruitment of eosinophils. Furthermore, they illustrate that inhibitors of DPPIV have the potential to interfere with chemokine-mediated effects in vivo including but not limited to allergy.

Regulation of expression and function of dipeptidyl peptidase 4 (DP4), DP8/9, and DP10 in allergic responses of the lung in rats

The expression of dipeptidyl peptidase 4 (DP4, CD26) affects T-cell recruitment to lungs in an experimental rat asthma model. Furthermore, the gene of the structural homologous DP10 represents a susceptibility locus for asthma in humans, and the functional homologous DP8/9 are expressed in human leukocytes. Thus, although several mechanisms may account for a role of DP4-like peptidases in asthma, detailed information on their anatomical sites of expression and function in lungs is lacking. Therefore, bronchi and lung parenchyma were evaluated using immunohistochemistry and histochemical/enzymatic activity assays, as well as quantitative real-time PCR for this family of peptidases in naïve and asthmatic rat lungs derived from wild-type F344 and DP4-deficient F344 rat strains. Surprisingly, results show not only that the induction of experimental asthma increases DP4 enzymatic activity in the bronchoalveolar lavage fluid and parenchyma, but also that DP8/9 enzymatic activity is regulated and, as well as the expression of DP10, primarily found in the bronchial epithelium of the airways. This is the first report showing a differential and site-specific DP4-like expression and function in the lungs, suggesting a pathophysiologically significant role in asthma.

Dose-dependent recruitment of CD25+ and CD26+ T cells in a novel F344 rat model of asthma

The ovalbumin (OVA)-induced airway inflammation in rats is a commonly used model to explore the pathobiology of asthma. However, its susceptibility varies greatly between rat strains, and presently Brown Norway (BN) rats are preferentially used. Since recruitment of T cells to the lungs depends on the CD26 (dipeptidyl peptidase IV, DPPIV) expression, Fischer 344 strain (F344) rats are a highly relevant rat strain, in particular because CD26-deficient substrains are available. To establish a F344 rat model of asthma, we challenged F344 rats using different doses of aerosolized antigen (0%, 1%, 2.5%, 5%, and 7.5% OVA) and compared these effects with intratracheal instillation of OVA (1.5 mg/0.3 ml). Asthmoid responsiveness was determined by analysis of early airway responsiveness (EAR), antigen-specific IgE levels, as well as airway inflammation including the composition of T cell subpopulations in the bronchoalveolar lavage (BAL) and lung tissue with special respect to the T cell activation markers CD25 and CD26. Even low allergen doses caused allergen-specific EAR and increases of antigen-specific IgE levels. However, EAR and IgE levels did not increase dose dependently. Higher concentrations of OVA led to a dose-dependent increase of several immunological markers of allergic asthma including an influx of eosinophils, T cells, and dendritic cells. Interestingly, a dose-dependent increase of CD4(+)/CD25(+)/CD26(+) T cells was found in the lungs. Summarizing, we established a novel F344 rat model of aerosolized OVA-induced asthma. Thereby, we found a dose-dependent recruitment of cellular markers of allergic asthma including the activated CD4(+)/CD25(+)/CD26(+) T cell subpopulation, which has not been described in asthma yet.

Neuropeptide Y (NPY) cleaving enzymes: structural and functional homologues of dipeptidyl peptidase 4

N-terminal truncation of NPY has important physiological consequences, because the truncated peptides lose their capability to activate the Y1-receptor. The sources of N-terminally truncated NPY and related peptides are unknown and several proline specific peptidases may be involved. First, we therefore provide an overview on the peptidases, belonging to structural and functional homologues of dipeptidyl peptidase 4 (DP4) as well as aminopeptidase P (APP) and thus, represent potential candidates of NPY cleavage in vivo. Second, applying selective inhibitors against DP4, DP8/9 and DP2, respectively, the enzymatic distribution was analyzed in brain extracts from wild type and DP4 deficient F344 rat substrains and human plasma samples in activity studies as well as by matrix assisted laser desorption/ionisation-time of flight (MALDI-TOF)-mass spectrometry. Third, co-transfection of Cos-1 cells with Dpp4 and Npy followed by confocal lasermicroscopy illustrated that hNPY-dsRed1-N1 was transported in large dense core vesicles towards the membrane while rDP4-GFP-C1 was transported primarily in different vesicles thereby providing no clear evidence for co-localization of NPY and DP4. Nevertheless, the review and experimental results of activity and mass spectrometry studies support the notion that at least five peptidases (DP4, DP8, DP9, XPNPEP1, XPNPEP2) are potentially involved in NPY cleavage while the serine protease DP4 (CD26) could be the principal peptidase involved in the N-terminal truncation of NPY. However, DP8 and DP9 are also capable of cleaving NPY, whereas no cleavage could be demonstrated for DP2.

A microfluorometric method for quantifying RNA and DNA in terrestrial insects

Evidence is accumulating for a mechanistic linkage between body phosphorus content and growth and reproduction of individual organisms, due in part to variation in allocation of resources to ribosomal RNA. Testing this connection requires reliable methods of quantifying the nucleic acid content of individual organisms. Although methods for quantifying nucleic acids are available for a wide array of organisms, adaptation of such methods for study of insects has been neglected. Sensitive stains and high throughput fluorometric measurements are now available that substantially improve past methodologies. Here we present methods for the extraction and quantification of insect RNA and DNA based on the use of N-lauroylsarcosine and sonication for extraction, the nucleases RNase and DNase, and the use of microplate fluorescent assays to quantify nucleic acids as percent of body weight in insects. We illustrate the method using Drosophila and curculionid weevils.

Morphological changes in newborn pigs of alloxan diabetic sows

We compared morphologically newborn piglets of alloxan diabetic sows with those of control animals. There were no histochemically detectable marked differences between the two groups investigated. In particular no differences in glycogen content of the liver and heart were observed. In all cases the endocrine pancreas was immature with sporadic formation of islet structures. In both groups we were able to demonstrate A- and B-cells immunohistochemically but not a hyperplasia of the B-cell system. The results obtained correlate with the absence of hyperinsulinaemia in newborn pigs of alloxan diabetic sows. We were unable to demonstrate the morphological background or cause of the diminished glucose-induced insulin release in case of alloxan diabetes as was found in 8-day old piglets. Therefore, the changes in newborn pigs of alloxan diabetic sows do not correlate with those in diabetic fetopathy in human beings.

Low dose streptozotocin induced diabetes in mice. Metabolic, light microscopical, histochemical, immunofluorescence microscopical, electron microscopical and morphometrical findings

The experimental animal model of human insulin-dependent diabetes mellitus (IDDM, type I diabetes), which was for the first time described by Like and Rossini (1976) for Charles River CD-1 mice and produced by the application of multiple subdiabetogenic streptozotocin (SZ) doses, has been reproduced in the mouse strain C57 Bl/KsJ which has been bred over several generations at the Central Institute for Diabetes Karlsburg (since 1975). Male mice were given subdiabetogenic intraperitoneal injections of SZ (40 mg/kg b.w.) on five days running.--The simultaneously performed metabolic, light and electron microscopical, histochemical, fluorescence microscopical, and morphometric examinations show that the small doses of SZ lead to a metabolic disturbance in the islets of Langerhans already on the third day of the experiment (after the first two SZ injections) which is associated with a high-degree reduction or an interruption of the insulin production. Subsequently, on the 8th day (three days after the last SZ injection) up to the 20th day an insulitis occurs which is characterized by a target cell reaction of lymphocytes against the beta cells and leads to the lysis of the majority of the beta cells. In the course and after the insulitis, a persisting insulin deficiency diabetes develops with lacking signs of an attempt to replace the perished beta cells. For the time being, the nature of this target beta cell destruction by lymphocytes remains unclear. According to the enzyme-histochemical and electron microscopical results, the involved lymphocytes are natural killer cells (NK cells) rather than T cells. The release of the target cell reaction is obviously effected by the initial metabolic disturbances in the beta cells intervening in the insulin synthesis. Virus bodies do not play any role in this process. The importance of this animal model to human insulin-dependent diabetes mellitus is discussed.

Glomerular immune complex deposition, circulating immune complexes, and antibodies in experimental insulinopenic diabetes

Compared with control animals with a normal metabolism, rats with insulinopenic diabetes generally show an increase in glomerular deposition of complement-fixing immune complexes after immunization with bovine albumin and bovine gamma-globulin. Compared with the control group, the serum of the diabetic animals showed a reduction in the titers of IgM-isotype antibodies, which have a lower affinity. The concentration of the circulating immune complexes is the same. The increased frequency of glomular deposits in experimental diabetes can be explained by an increase in capillary permeability and by the formation of qualitatively different immune complexes.

[Alloxan induced long term diabetes in the domestic pig. I]

An insulin-deficient diabetes of long duration was induced by intravenous injection of alloxanmonohydrate (200 mg/kg and 100 mg/kg body mass, respectively) in 23 pigs (Landrace, Duroc) of 20-44 kg body mass. The dose of 200 mg/kg body mass was too high and there were fatal outcomes only. With the dose of 100 mg/kg and an initial body mass of 30-35 kg it is possible to induce a chronic diabetes mellitus in the pig. As complications we observed intoxications caused by alloxan, hypoglycemic situations from the 6th hour after application of alloxan with possible hypoglycemic damages, and septic complications by the intravenous catheter. Five out of 23 animals are still alive, 2 animals for 31 months and the others for 19 months. All the living animals have plasma glucose levels between 11 and 17 mmol/1 with very low values of plasma insulin. The serum triglycerides increased slightly in some cases, but not the serum cholesterol. The weight gain is retarded.

Renal biopsies performed on diabetics

Metabolic disorders and immunological factors are discussed in connection with the pathogenesis of diabetic microangiopathy. Renal biopsies were obtained from 22 diabetics (8 women aged 18 to 53, 14 men aged 15 to 52). 7 of the 22 patients had been suffering from diabetes for 2 weeks to 3 years, 10 for 7 to 25 years, 2 showed a pathological glucose-tolerance test, i.e., they had been "latent" diabetics, and 3 patients, had been so-called "potential" subjects of diabetes due to hereditary traits or delivery of big babies. They were examined by light miroscopy as well as by immunofluorescence microscopy. A number of cases were chosen for the differentiation and counting of glomerular cells (n=8) as well as for electron microscopic (n=7) and polarizing-microscopic (n=6) examinations. Histologically, focal proliferations of mesangial cells as well as an increase in mesangial substance in the glomeruli was found in all cases, although in a varying degree of intensity. These results were confirmed by both the glomuerular cell count and electron-microscopic examination. Immunofluorescence microscopy made it possible to detect frequently both IgA (9/17) and IgG (9/17), usually in either linear or mesangial arrangements whereas it was less frequently possible to detect IgM (1/17) and albumin (1/8) and impossible to detect beta1C in the glomerulus. Labeled insulin was detected five times in the glomerulus. Polarizing-microscopic measurements made in order to discover possible submicroscopic variations in the structure of GBM showed deviations in the average values of anisotropic indices from the controls in the group of long-term diabetics only. The pathogenesis of diabetic microangiopathy may be described as an inflow of immunoglobulins and serum proteins into the mesangium because of an alteration of the capillary endothelium, the mesangial cell being thus caused to overfunction, proliferate and produce an excess of mesangial matrix. In prolonged diabetes the mesangial cell, so far as its own metabolism is concerned, will finally be affected to the point where its power of synthesis is modified in the sense of an excess and/or faulty composition of GBM (glomerular basement membrane).