bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunohistochemical and Histopathologic Features of 14 Malignant Fibrous Histiocytomas from Flat-Coated Retrievers
Authors: Morris J. S. , McInnes E. F. , Bostock D. E. , Hoather T. M. , Dobson J. M.
Published: April 2003

Flat-Coated Retrievers seem to be at increased risk of developing soft-tissue sarcomas, and undifferentiated round cell or spindle cell sarcomas account for approximately 59% of sarcomas in the breed. In an attempt to classify these tumors further, formalin-fixed, paraffin-embedded sections from 14 undifferentiated sarcomas from Flat-Coated Retrievers were reviewed and examined with a panel of histologic and immunohistochemical stains. The panel included vimentin, desmin, Myo D1, smooth muscle actin, cytokeratin, S100, von Willebrand factor (factor VIII), Mac 387, CD3, major histocompatibility complex (MHC) class II, and CD79a. The majority of the sarcomas showed greater than 70% staining for MHC class II. We conclude that these undifferentiated sarcomas in Flat-Coated Retrievers belong to a spectrum of tumors with varying proportions of characteristic cell types and morphologic features, some of which fit the diagnostic criteria for malignant fibrous histiocytoma. Many of these sarcomas seem to have a significant myofibroblast component and a mild or moderate T cell infiltrate but the precise cell lineage is still uncertain.
Bronchitis and Bronchiolitis in a Cat with Cilia-associated Respiratory Bacillus-like Organisms
Authors: Ramos-Vara J. A. , Franklin C. , Miller M. A.
Published: April 2003

A 10-year-old male domestic shorthair cat died during anesthesia. Grossly, the lungs had multiple nodules corresponding to inflamed airways (bronchitis and bronchiolitis). Microscopically, cuffs and nodular aggregates of lymphocytes and plasma cells surrounded airways. Peribronchiolar fibrosis was also common. Globule leukocytes infiltrated the respiratory epithelium of noninflamed or mildly inflamed bronchi. Argyrophilic and filamentous organisms, consistent with cilia-associated respiratory bacillus-like organisms (CLO), were intermixed with cilia of respiratory epithelium. Ultrastructurally, CLO were longer and thinner than cilia and had a distinct trilaminar membrane, central electron-lucent areas, and no specialized external structures. Silver stained lung sections from 18 additional feline airways revealed similar bacilli in 2/9 normal lungs, 1/7 lungs with bronchitis and bronchiolitis, and 1/2 lungs with pneumonia. The significance of CLO in the pulmonary lesions was not determined.
Myofiber Expression of Class I Major Histocompatibility Complex Accompanied by CD8+ T-cell-associated Myofiber Injury in a Case of Canine Polymyositis
Authors: Morita T. , Shimada A. , Yashiro S. , Takeuchi T. , Hikasa Y. , Okamoto Y. , Mabuchi Y.
Published: April 2003

A 7-year-old female Labrador Retriever dog showed extreme muscular weakness, muscle wasting, dysbasia, and mild dysphagia. An elevated value of creatine kinase (335 IU/liter) in the serum was detected. Electromyographic findings included increased insertional activity, fibrillation potentials, and bizarre high-frequency repetitive potentials. Histopathologic examination of skeletal muscles revealed myofiber necrosis and phagocytosis, regeneration of myofibers, and perivascular, perimysial, and endomysial infiltrations of lymphocytes, macrophages and plasma cells. Immunohistochemical evaluation demonstrated that infiltrative cells in the early stage of myositis were CD8+ T-cells and that an increased expression of major histocompatibility complex (MHC) class I was apparent on the surface of nonnecrotic muscle fibers. In contrast, many CD3+ cells (T cells) and HLA-DR-positive macrophages and B lymphocytes were found in the severely affected areas. These results suggest that both expression of MHC class I and CD8+ T-cell infiltration may play an important role in initiation of myositis. These histopathologic findings resemble those reported in naturally occurring polymyositis in humans.
Distribution of Protease-resistant Prion Protein and Spongiform Encephalopathy in Free-ranging Mule Deer (Odocoileus hemionus) with Chronic Wasting Disease
Authors: Spraker T. R. , Zink R. R. , Cummings B. A. , Sigurdson C. J. , Miller M. W. , O'Rourle K. I.
Published: April 2003

Serial sections of brain and palatine tonsil were examined by immunohistochemical staining (IHC) using monoclonal antibody F89/160.1.5 for detecting protease-resistant prion protein (PrPres) in 35 hunterkilled mule deer ( Odocoileus hemionus) with chronic wasting disease. Serial sections of brain were stained with hematoxylin and eosin and examined for spongiform encephalopathy (SE). Clinical signs of disease were not observed in any of these deer. On the basis of the location and abundance of IHC and the location and severity of SE, deer were placed into four categories. Category 1 ( n = 8) was characterized by IHC in the palatine tonsil with no evidence of IHC or SE in the brain. Category 2 ( n = 13) was characterized by IHC in the palatine tonsil and IHC with or without SE in the dorsal motor nucleus of the vagus nerve (DMNV). Category 3 ( n = 2) was characterized by IHC in the palatine tonsil, IHC with SE in the myelencephalon, and IHC without SE in the hypothalamus. Category 4 ( n = 12) was characterized by IHC in the palatine tonsil and IHC with SE throughout the brain. Category 1 may represent early lymphoid tissue localization of PrPres. The DMNV appears to be the most consistent single neuroanatomic site of detectable PrPres. Categories 2–4 may represent a progression of spread of PrPres and SE throughout the brain. IHC in tonsil and brain and SE in brain were not detected in 208 control deer.
Mast Cell Tumors of the Gastrointestinal Tract in 39 Dogs
Authors: Ozaki K. , Yamagami T. , Nomura K. , Narama I.
Published: April 2003

Mast cell tumors (MCTs) of gastrointestinal origin that had been surgically removed from 39 dogs were examined to evaluate their pathologic features. Miniature breeds, especially Maltese, were most frequently affected. The average age of affected dogs was 9.7 ± 2.6 years. No sex difference was apparent. The most frequently affected sites were in the upper digestive tract, and the prognosis was very poor. Grossly, the gastrointestinal wall was prominently thickened, and the lumen of the affected gut was usually narrowed. Microscopically, there was diffuse transmural invasion of round to pleomorphic tumor cells. Tumor cells had moderate to abundant cytoplasm, round to ovoid nuclei with scattered chromatin, and mitotic figures. Fibrous stroma was observed in about half of the tumors. There was variable infiltration of eosinophils. In all tumors, cytoplasmic granules showed weak metachromasia, but the number of granules was very small. Immunohistochemical staining for c-kit and mast cell tryptase was positive in 77% and 62% of tumors, respectively. All tumors were positive for at least two of these markers. Immunohistochemical staining for p53 was positive in 13% of the tumors. Reactivity for staining markers and p53 was unrelated to cell pleomorphism, vessel invasion, or survival time. Gastrointestinal MCTs have histologic and immunohistochemical features completely different from those of other primary or metastatic gastrointestinal tumors. The combination of immunostaining for mast cell tryptase and c-kit and histochemical staining for metachromasia appears to be a powerful tool for the diagnosis of gastrointestinal MCTs.
Immunohistopathology of Calf Pneumonia Induced by Endobronchial Inoculation with Bovine Adenovirus 3
Authors: Narita M. , Yamada M. , Tsuboi T. , Kawashima K.
Published: April 2003

Three 1-week-old and three 3-month-old Holstein calves that had received colostrum were inoculated endobronchially with bovine adenovirus 3 (BAV-3). The gross and histologic lesions in these six infected calves were localized mainly in the right caudal lobe of the lung and were closely associated with the site of the deposition of the inoculum. The pneumonic lesions were severe necrotizing bronchitis, bronchiolitis, and alveolitis, accompanied by infiltration of inflammatory cells and proliferation of type 2 pneumocytes. Intranuclear inclusion bodies, BAV-3 antigen, and virus particles were detected in the degenerated epithelial cells in the 1-week-old but not the 3-month-old calves. After infection, the total cell count in the bronchoalveolar lavage (BAL) fluid cells was increased. The results of BAV-3 isolation from BAL fluid were correlated with the detection of intranuclear inclusion bodies in the desquamated epithelial cells in the BAL fluid cells from the right caudal lobe but not in cells from the left caudal lobe. CD8+ T lymphocytes in the pneumonic lesion were found only in the 3-month-old infected calves. The difference in the immunopathologic reactions between the 1-week-old and the 3-month-old infected calves may be attributed to differences in immune system development.
Endometrial Hyperplasia, Polyps, and Adenomyosis Associated with Unopposed Estrogen in Rhesus Monkeys (Macaca mulatta)
Authors: Baskin G. B. , Smith S. M. , Marx P. A.
Published: April 2003

The purpose of this study was to evaluate the effects of estrogen and progesterone on the vaginal mucosa and their role in vaginal transmission of simian immunodeficiency virus. Incidentally, endometrial hyperplasia was observed in estrogen-treated monkeys at necropsy. Six adult female rhesus monkeys ( Macaca mulatta) were ovariectomized and 120 days later received two subcutaneous implants, each containing 200 mg estradiol. The animals were sacrificed 17–27 months later and the uterus examined at necropsy. All the monkeys had simple endometrial hyperplasia, some with polyps or adenomyosis, at the time of necropsy. The severity of the changes correlated with the time between implantation and necropsy. The lesions were similar to endometrial hyperplasia caused by unopposed estrogen in women, but occurred over a time period that is suitable for experimental manipulation. Rhesus monkeys could be used as a model to test the safety of various combinations of sex steroids for the prevention of postmenopausal symptoms in women.
Uterine Leiomyomas in Two Vietnamese Pot-bellied Pigs (Sus scrofa)
Authors: Munday J. S. , Stedman N. L.
Published: April 2003

Two Vietnamese pot-bellied pigs ( Sus scrofa) were euthanatized after they developed abdominal distension. Necropsy of both pigs revealed large myometrial neoplasms and cystic endometrial hyperplasia. Multiple discrete smaller myometrial neoplasms were also observed in one pig; however, distant metastases were not observed in either animal. The tumors were diagnosed as leiomyomas on the basis of histologic examination and immunohistochemistry. This is the first detailed report of uterine leiomyomas in swine, and it is suggested that this diagnosis may become more common as more aging pigs are examined.
Severe Biliary Hyperplasia Associated with Liver Fluke Infection in an Adult Alpaca
Authors: Hamir A. N. , Smith B. B.
Published: April 2003

An adult alpaca ( Lama pacos) had a locally extensive area of hepatic atrophy involving the right lobe. Grossly, the atrophic lobe was light tan and firm and contained small, raised, white to yellow, partially mineralized circular nodules predominantly at the periphery of the atrophic tissue. Microscopically, viable hepatocytes were not present in the atrophic area, and the tissue consisted of diffuse biliary epithelial proliferation without any evidence of nuclear or cellular atypia or the presence of mitotic figures. The circular mineralized nodules consisted of granulomatous inflammation with intralesional parasitic ova surrounded by fibrous connective tissue. Morphologically, the ova were compatible with those of Fasciola hepatica. The severe biliary hyperplasia was unusual, and it was not clear whether it was caused by an aberrant host response to the parasitic infection or whether it was an unrelated event.
Cellular Distribution of Anionic Antimicrobial Peptide in Normal Lung and during Acute Pulmonary Inflammation
Authors: Fales-Williams A. J. , Brogden K. A. , Huffman E. , Gallup J. M. , Ackermann M. R.
Published: April 2003

Anionic peptides (APs) are small antimicrobial peptides present in human and ovine lung. In this study APs were also detected in bovine lung, and production of APs in lungs with acute inflammation induced by various stimuli was determined. The distribution and intensity of APs were determined by immunohistochemistry in lungs of 1) neonatal calves (1-3 days of age) inoculated with Mannheimia (Pasteurella) haemolytica, a known inducer of the bovine β-defensin lingual antimicrobial peptide (LAP) or pyrogen-free saline (PFS), and 2) growing calves (3 months of age) similarly inoculated with M. haemolytica, a lipopolysaccharide (LPS) from M. haemolytica, an LPS-associated protein from M. haemolytica, or PFS. APs were also detected by western blots with the same antibody in lungs of the calves above, as well as in calves inoculated with Pseudomonas aeruginosa, and an adult cow. Anionic peptide (AP) immunoreactivity was detected in bands (approximate weights) in the western blots of lung at 28-30 (strongest signal), 31, 45, and 52-60 kd regardless of inoculum. The adult cow lacked bands at 45 kd, but it had additional bands at 64 (inconsistently) and 35-38 kd. All these band sizes are consistent with those of the western blots of human and ovine lung. The cellular distribution of APs in lung of neonatal and growing cattle was similar to that in lung of human and sheep. In lungs with acute inflammation induced by live bacteria, LPS, or protein, AP distribution and intensity were similar to those in control (PFS-inoculated) lungs and slightly decreased in bronchioles. This work demonstrates that AP is present in lung of cattle and is thereby conserved among two ruminant species and man. Distribution and intensity of AP production are not enhanced by infection or acute inflammation and are decreased in bronchioles, which suggests that AP is not induced like β-defensins such as LAP, but, instead, is produced constitutively.
Early Epithelial Invasion by Salmonella enterica Serovar Typhimurium DT104 in the Swine Ileum
Authors: Meyerholz D. K. , Stabel T. J. , Ackermann M. R. , Carlson S. A. , Jones B. D. , Pohlenz J.
Published: April 2003

Salmonella enterica serovar Typhimurium is an important intestinal pathogen in swine. This study was performed to document the early cellular invasion of Salmonella serovar Typhimurium in swine ileum. Ileal gut-loops were surgically prepared in ten 4- to 5-week-old mixed-breed pigs and inoculated for 0-60 minutes. Loops were harvested and prepared for both scanning and transmission electron microscopy (SEM and TEM, respectively). Preferential bacterial adherence to microfold cells (M cells) was seen within 5 minutes, and by 10 minutes bacterial invasion of the apical membrane was seen in M cells, goblet cells, and enterocytes. This multicellular invasion was observed throughout the course of infection. In addition, SEM revealed a specific affinity of Salmonella serovar Typhimurium to sites of cell extrusion. Using TEM, bacteria in these areas were focused in the crevices formed by the extruding cell and the adjacent cells and in the cytoplasm immediately beneath the extruding cell. Our results suggest that early cellular invasion by Salmonella serovar Typhimurium is nonspecific and rapid in swine. Furthermore, the combination of SEM and TEM data suggests that Salmonella serovar Typhimurium may use sites of cell extrusion as an additional mechanism for early invasion.
Fluorescein: A Rapid, Sensitive, Nonlethal Method for Detecting Skin Ulceration in Fish
Authors: Noga E. J. , Udomkusonsri P.
Published: April 2003

There is a need to develop simple, rapid, and accurate methods for assessing health in fish populations. In this study we demonstrate that use of fluorescein, a nontoxic fluorescent dye, can rapidly and easily detect the presence of skin ulcers in all fish tested, including rainbow trout (Oncorhynchus mykiss), channel catfish (Ictalurus punctatus), goldfish (Carassius auratus), and hybrid striped bass (Morone saxatilis male X M. chrysops female). Exposure of fish to as little as 0.10 mg fluorescein per milliliter of water for 3 minutes was sufficient to identify experimentally induced lesions, even pinpoint ulcerations. Such lesions were not visible to the naked eye but were clearly demarcated with fluorescein treatment. Examination of fish that appeared clinically normal often revealed the presence of focal ulcerations, which might have been a consequence of damage during capture, but it also might suggest that skin ulceration may be common even in “clinically normal” fish. Exposure of either nonulcerated or experimentally ulcerated hybrid striped bass to an excessively high concentration of fluorescein had no apparent effect on health or survival. Our studies suggest that fluorescein may be a highly useful tool for rapid health screening in fish populations.
Varied Pathogenicity of a Hong Kong-origin H5N1 Avian Influenza Virus in Four Passerine Species and Budgerigars
Authors: Perkins L. E. L. , Swayne D. E.
Published: April 2003

This investigation assessed the ability of the zoonotic A/chicken/Hong Kong/220/97 (chicken/Hong Kong) (H5N1) highly pathogenic avian influenza virus to infect and cause disease in zebra finches ( Taeniopygia guttata), house finches ( Carpodacus mexicanus), house sparrows ( Passer domesticus), European starlings ( Sternus vulgaris), and budgerigars ( Melopsittacus undulatus) after intranasal administration. Zebra finches were the most severely affected of the five species, demonstrating anorexia, depression, and 100% mortality within 5 days of inoculation. Gross lesions in this species were absent or only mild. But histologic lesions and the corresponding viral antigen were observed in multiple organs, especially in the nasal cavity, brain, pancreas, spleen, adrenal glands, and ovary. Significant morbidity and mortality also were observed in both house finches and budgerigars. Affected birds of these two species demonstrated anorexia, depression, and neurologic signs and typically were moribund or dead within 2 days of the onset of clinical signs. Gross lesions were mild or absent in house finches and budgerigars. Histologically, the brain and pancreas were the most consistently and severely affected organs in house finches. The brain was the most affected organ in budgerigars. Unlike these three species, house sparrows suffered only mild transient depression, had no mortality, and lacked gross lesions. Viral antigen and microscopic lesions were observed only in the heart and testicle of a minority of birds of this species. Starlings demonstrated neither clinical disease nor mortality and lacked gross and histologic lesions. Viral antigen was not observed in any of the collected tissues from starlings. These results indicate that there is significant variation in the pathogenicity of the chicken/Hong Kong virus for different species of birds, including species within the same order. In addition, neurotropism is a recurrent feature among birds that eventually succumb to infection.
Immunohistochemical Detection of Uroplakin III, Cytokeratin 7, and Cytokeratin 20 in Canine Urothelial Tumors
Authors: Ramos-Vara J. A. , Miller M. A. , Boucher M. , Roudabush A. , Johnson G. C.
Published: April 2003

Immunohistochemistry for uroplakin III (UP III), cytokeratin 7 (CK 7), and cytokeratin 20 (CK 20) using commercially available antibodies was done in normal canine urinary bladder and 72 canine urinary bladder tumors that had been fixed in formalin and embedded in paraffin. Prolonged fixation (3–28 days) did not significantly alter the immunostaining for UP III. There was moderate reduction in the intensity for CK 7 and CK 20 after 1 week of fixation. UP III was detected in superficial (umbrella) cells and some intermediate cells of the normal urinary bladder, 7 of 7 transitional cell papillomas (TCPs), 50 of 55 transitional cell carcinomas (TCCs), and 4 of 5 metastatic TCCs. Staining was typically outlined in the plasma membrane, but diffuse or focal cytoplasmic staining was also observed. Intracytoplasmic lumina were usually positive for UP III. One squamous cell carcinoma of the bladder, 4 nonepithelial bladder tumors, and 285 nonurothelial tumors from different nonurinary locations were negative for UP III. CK 7 was detected in 7 of 7 TCPs, 53 of 54 TCCs, and 5 of 5 metastatic TCCs. The staining for CK 7 was diffuse cytoplasmic. CK 20 was detected in 1 of 7 TCPs, 37 of 54 TCCs, and 1 of 5 metastatic TCCs. The staining with CK 20 was cytoplasmic and weaker than with antibodies to UP III or CK 7. There was concurrent expression of UP III, CK 7, and CK 20 in 36 of 54 TCCs. UP III is a specific and sensitive marker for canine transitional epithelial (urothelial) neoplasms, detecting 91% of TCCs. Negative results may be observed with anaplastic tumors.
Gliomatosis Cerebri in Six Dogs
Authors: Porter B. , DeLahunta A. , Summers B.
Published: April 2003

Gliomatosis cerebri is a well-recognized entity in human medicine characterized by unusually widespread infiltration of the neuraxis by neoplastic glial cells with relative preservation of brain architecture. This report describes the pathologic features of the disease in six dogs. The dogs ranged from 3 to 9 years of age (mean 6.1 years) without evidence of breed predilection; five of the six dogs were neutered or intact males. The clinical findings were mixed (including depression, circling, cranial nerve deficits), reflecting the diffuse nature of the disease. Histologically, there was remarkably diffuse infiltration of the white and gray matter of the brain by small numbers of elongated neoplastic cells. Areas of greater cellularity formed grossly visible lesions in four cases. Anisocytosis and pleomorphism were greater in areas of higher cellularity. Other features of tumor growth included subpial accumulation, neuronal satellitosis, perivascular cuffing, and tropism for cranial nerve and brain stem nuclei. Neoplastic cells were negative on immunohistochemical stains for glial fibrillary acid protein (GFAP) and leukocyte markers, reflecting the uncertain histogenesis of these unusual neoplasms.
Renal Lesions in Spontaneous Insulin-dependent Diabetes Mellitus in the Nonobese Diabetic Mouse: Acute Phase of Diabetes
Authors: Maeda M. , Yabuki A. , Suzuki S. , Matsumoto M. , Taniguchi K. , Nishinakagawa H.
Published: April 2003

The nonobese diabetic mouse is a model of spontaneous insulin-dependent diabetes mellitus. The present study made longitudinal observations of renal lesions in the acute-progressive phase of diabetic mice 0, 10, 20, 30, and 40 days after onset of diabetes without insulin therapy. Plasma creatinine and blood urea nitrogen concentrations gradually increased after onset of diabetes. Kidney weight increased and plateaued at day 20. Under electron microscopy the glomeruli demonstrated only mild changes on day 40. In the proximal tubules proliferating cell nuclear antigen-positive nuclei and nuclear divisions were increased on days 10 and 20. On day 40 of diabetes, increased periodic acid-Schiff-positive granules, confirmed as lysosomal dense bodies, increased neuronal nitric oxide synthase (nNOS) positive reaction, and decreased periodic acid-Schiff staining in the brush border were observed in the proximal straight tubules. In the juxtaglomerular apparatus stratified macula densa were decreased with time in diabetes compared with the findings on day 0, and this macula densa positively reacted with nNOS. No changes in renin levels were observed. In addition, apoptotic cells were not detected. In conclusion, this research represents the first thorough characterization of acute changes in nonobese diabetic mouse kidneys. The results demonstrated renal hypertrophy and slight glomerular injury in early stages and structural alteration of the proximal straight tubules at later stages during the acute phase of diabetes. Furthermore, increased nNOS may represent one of the pathogenic factors of diabetic nephropathy.
Behavioral effects of testosterone in relation to social rank in the male rabbit
Authors: Briganti Federica , Della Seta Daniele , Fontani Giuliano , Lodi Leda , Lupo Concetta
Published: April 2003

The role of gonadal androgens in favoring the adaptation to environmental pressure, including social organization, is well known. In the rabbit, testosterone administration increases marking behavior, and its level can be affected by agonistic interaction. In this experiment, we studied the effect of subcutaneous administration of testosterone propionate (TP) (3 mg/d for 6 days) in male rabbits belonging to the same social group (6 groups of 4 animals). In 2 additional groups (4 animals each), males were injected with almond oil. The animals were observed for 6 days in seminatural conditions, then treated with TP (or oil) and observed for another 6 days. The dominant/subordinate frequency ratio of behavioral patterns was used to rank the animals. The testosterone plasma concentration was correlated with agonistic behavior after the first period of social interaction. A significant increase of marking, digging, and defensive activity was observed after TP administration in all animals independent of rank, whereas this increase was not present in animals treated with oil. Agonistic and interactive behaviors increased significantly after TP treatment only in the first‐ranking animals. This indicates the influence of social rank in the modification of behaviors involving interactions among subjects Aggr. Behav. 29:269–278, 2003. © 2003 Wiley‐Liss, Inc.
Prevalence estimation of school bullying with the Olweus Bully/Victim Questionnaire
Authors: Solberg Mona E. , Olweus Dan
Published: April 2003

The key aim of the present research was to study the “functionality” of two global variables in the Olweus Bully/Victim Questionnaire and to examine the appropriateness of different cutoff points of these variables for prevalence estimation. Several empirical and conceptual analyses strongly attested to the functionality of the two selected variables in terms of construct validity and selected measurement properties. Similarly, a number of analyses indicated that (having been bullied/having bullied other students) “2 or 3 times a month” was a reasonable and useful lower‐bound cutoff point. With this cutoff point, “involved” students, victims, and bullies differed very markedly and in clearly different ways from “non‐involved” students in conceptually related variables. Prevalence estimates derived in this way can be conveniently obtained, have a reasonably well‐defined meaning, can be easily understood by users, and can be reproduced unambiguously by different researchers/administrators and at different times. An important background for the article is the fact that several common methods, including peer nominations, are not well suited for prevalence estimation. Prevalence data for victims, bullies, and bully‐victims are also presented. All data were derived from the New Bergen Project Against Bullying, comprising a sample of 5,171 students from 37 schools in the town community of Bergen, Norway. At the time of the data collection, the spring of 1997, the 2,544 girls and 2,627 boys were in grades 5 through 9, with modal ages of 11 through 15 years. Aggr. Behav. 29:239–268, 2003. © 2003 Wiley‐Liss, Inc.
New Silica‐Immobilized Nickel Catalysts for Cyclotrimerizations of Acetylenes
Authors: Reinhard S. , Šoba P. , Rominger F. , Blümel J.
Published: April 2003

New dicarbonylnickel catalysts with a variety of mono‐ and bidentate phosphine ligands, such as Ph2P(CH2)xPPh(CH2)ySi(OEt)3 (x=2, 3; y=2, 3), have been synthesized and fully characterized, three of them by X‐ray analyses. All the catalysts have been immobilized on silica by reaction of the ethoxysilane or hydroxy groups of the phosphine linkers with the surface silanol groups. The clean immobilization was proved by 31P solid‐state NMR. It has been demonstrated that the COSi bridge, in contrast to the strong SiOSi bond, is easily cleaved by organic solvents and water. With respect to the cyclotrimerization of phenylacetylene the optimal reaction conditions for all molecular and immobilized catalysts have been determined. Cyclooctane was the best solvent, and the optimal reaction temperature was 100 °C for reactions in homogeneous phase, and 155 °C for surface‐bound catalysts. The bite angles and spacer lengths of the chelating ligands did not play a major role for the performance of the homogeneous or immobilized catalysts. The latter could be recycled for 12 times, with final substrate conversions still typically between 30 and 40%, and turnover numbers (TON) around 1500. With an excess of substrate in one run a TON of 4810 was obtained for an immobilized carbonylnickel complex with a dppp‐type chelate phosphine (x=3, y=2). Reduction of the surface coverage generally resulted in catalysts with longer lifetimes, for example, reduction to one fourth gave a record TON of 7616 for this catalyst. The selectivities of the catalysts all followed one trend. The main products were the cyclotrimers 1,2,4‐ and 1,3,5‐triphenylbenzene, besides dimers, linear trimers and tetramers as side‐products. The fraction of the latter decreased at higher temperatures with homogeneous catalysts, and vanished entirely after a few cycles with the immobilized catalysts. On recycling, the initial ratio of unsymmetrical to symmetrical cyclotrimers of typically 5 : 1 gradually changed to about 1 : 1 for all catalysts.
Three‐Component One‐Pot Synthesis of α‐Hydroxylamino Phosphonates using Ionic Liquids
Authors: Yadav J. S. , Reddy B. V. S. , Sreedhar P.
Published: April 2003

α‐Hydroxylamino phosphonates are synthesised in a one‐pot operation by three‐component coupling reactions of aldehydes, hydroxylamines and diethyl phosphite using 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([bmim]BF4) or 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([bmim]PF6) ionic liquids under mild and neutral conditions. The recovered ionic liquids can be recycled for four to five runs without loss of activity.
Responding to homelessness: an overview of US and UK policy interventions
Authors: O'Connell Mary Ellen
Published: April 2003

This article compares UK and US social welfare, policy and practice responses to homelessness, with the aim of identifying differences and similarities in the systems, and drawing out lessons for future policy and practice interventions, particularly as they relate to researching the issues. An introductory section briefly sets out the policy and practice context for homelessness in both countries. Next, the main part of the article systematically highlights the continuities between the response to homelessness in the UK and US, and seeks to explain some of the questions arising from this. Finally, the article draws this together by discussing implications for future interventions and research. Copyright © 2003 John Wiley & Sons, Ltd.
A C2‐Chiral Bis(amidinium) Catalyst for a Diels−Alder Reaction Constituting the Key Step of the Quinkert−Dane Estrone Synthesis
Authors: Tsogoeva Svetlana B. , Dürner Gerd , Bolte Michael , Göbel Michael W.
Published: April 2003

A novel C2‐chiral bis(amidinium) salt 12 has been synthesised from 5‐(tert‐butyl)isophthalic acid. The hydrogen‐bond‐mediated association of dienophiles 3a and 3b with the chiral host molecule 12 accelerates the Diels−Alder reactions with diene 2 by more than three orders of magnitude. In addition, enantioselective formation of the desired adducts is observed under catalysis with 12. Good ratios of 4a(b) + ent‐4a(b)/5a(b) + ent‐5a(b) from 1:10 to 1:22 were found in all reactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Nitration of Heteroaryltrimethyltins by Tetranitromethane and Dinitrogen Tetroxide: Mechanistic Aspects, Scope and Limitations
Authors: Fargeas Valérie , Favresse Fabien , Mathieu Didier , Beaudet Isabelle , Charrue Pierre , Lebret Bruno , Piteau Marc , Quintard Jean‐Paul
Published: April 2003

The nitration of 2‐(trimethylstannyl)heteroarenes by tetranitromethane (TNM) or dinitrogen tetroxide has been shown to be possible when the HOMO energy of the heteroaryltin is high enough to allow the formation of the corresponding radical cation. The reaction proceeds through a charge‐transfer complex between heteroaryltin and TNM, followed by a single‐electron transfer, which is enhanced under sunlamp irradiation. Accordingly, 2‐nitrobenzo[b]furan, 2‐nitrobenzo[b]thiophene, 2‐nitropyridine and 2‐nitroindoles were obtained by this method. However, the nitration of 2‐stannylated pyrimidine or of stannylated 1,3,5‐triazines has been shown to be impossible, due to the low energy of their HOMO orbitals. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A flexible nudged elastic band program for optimization of minimum energy pathways using ab initio electronic structure methods
Authors: Alfonso Dominic R. , Jordan Kenneth D.
Published: April 2003

A driver program for carrying out nudged elastic band optimizations of minimum energy reaction pathways is described. This approach allows for the determination of minimum energy pathways using only energies and gradient information. The driver code has been interfaced with the GAUSSIAN 98 program. Applications to two isomerization reactions and to a cluster model for H2 desorption from the Si(100)‐2x1 surface are presented. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 990–996, 2003
Pharmaceutical antibiotic compounds in soils – a review
Authors: Thiele‐Bruhn Sören
Published: April 2003

Antibiotics are highly effective, bioactive substances. As a result of their consumption, excretion, and persistence, they are disseminated mostly via excrements and enter the soils and other environmental compartments. Resulting residual concentrations in soils range from a few μg upto g kg–1 and correspond to those found for pesticides. Numerous antibiotic molecules comprise of a non‐polar core combined with polar functional moieties. Many antibiotics are amphiphilic or amphoteric and ionize. However, physicochemical properties vary widely among compounds from the various structural classes. Existing analytical methods for environmental samples often combine an extraction with acidic buffered solvents and the use of LC‐MS for determination. In soils, adsorption of antibiotics to the organic and mineral exchange sites is mostly due to charge transfer and ion interactions and not to hydrophobic partitioning. Sorption is strongly influenced by the pH of the medium and governs the mobility and transport of the antibiotics. In particular for the strongly adsorbed antibiotics, fast leaching through soils by macropore or preferential transport facilitated by dissolved soil colloids seems to be the major transport process. Antibiotics of numerous classes are photodegraded. However, on soil surfaces this process if of minor influence. Compared to this, biotransformation yields a more effective degradation and inactivation of antibiotics. However, some metabolites still comprise of an antibiotic potency. Degradation of antibiotics is hampered by fixation to the soil matrix; persisting antibiotics were already determined in soils. Effects on soil organisms are very diverse, although all antibiotics are highly bioactive. The absence of effects might in parts be due to a lack of suitable test methods. However, dose and persistence time related effects especially on soil microorganisms are often observed that might cause shifts of the microbial community. Significant effects on soil fauna were only determined for anthelmintics. Due to the antibiotic effect, resistance in soil microorganisms can be provoked by antibiotics. Additionally, the administration of antibiotics mostly causes the formation of resistant microorganisms within the treated body. Hence, resistant microorganisms reach directly the soils with contaminated excrements. When pathogens are resistant or acquire resistance from commensal microorganisms via gene transfer, humans and animals are endangered to suffer from infections that cannot be treated with pharmacotherapy. The uptake into plants even of mobile antibiotics is small. However, effects on plant growth were determined for some species and antibiotics.
Influence of load on shrinkage behavior of peat soils
Authors: Oleszczuk Ryszard , Bohne Klaus , Szatylowicz Jan , Brandyk Tomasz , Gnatowski Tomasz
Published: April 2003

The shrinkage of the peat soils that accompanies the soil moisture changes is an important feature of such soils and has strong influence on their physical attributes and soil water management. The relationships between soil moisture and volume are often described using shrinkage characteristic curves by relating void ratio (volume of voids per unit volume of solids) to moisture ratio (volume of water per volume of solids). For conversion of soil volume changes into cracks volume and subsidence, a dimensionless shrinkage geometry factor is used. The paper presents results of volumetric shrinkage behavior and the geometry factor at various loads in sedge and alder peat soils. The measurements were conducted on undisturbed soil samples without applying a load and with loads corresponding to field overburden. The shape of the shrinkage characteristics of such soils were completely different from those of clay soils. The application of loads did not significantly influence the shrinkage characteristics curve. The applied load strongly influenced on relationship between shrinkage geometry factor and the moisture ratio, showing higher values of subsidence and lower values of crack volume in comparison with unloaded conditions.
Nanocomposites from Layered Silicates: Graft Polymerization with Intercalated Ammonium Peroxides
Authors: Albrecht Martin , Ehrler Stefan , Mühlebach Andreas
Published: April 2003

Nanocomposites were prepared by butyl acrylate graft polymerization from montmorillonite‐type layered silicates. Successful polymer grafting required novel dialkyl peroxides comprising two cationic ammonium groups, which were intercalated in the layered silicate by cation exchange. Thermal cleavage of the peroxide functionality in the presence of butyl acrylate as monomer initiated polymerization and hence exfoliation of the layers. Detailed examination of this process shows that the polymerization cannot be controlled by external nitroxides.

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Alteration of O6‐methylguanine‐DNA methyltransferase in colorectal neoplasms in sporadic and familial adenomatous polyposis patients
Authors: Kim Sun Hee , Bae Soo In , Lee Hye Seung , Kim Woo Ho
Published: April 2003

DNA repair failure is known to be a critical event during carcinogenesis of colorectal cancers. To investigate whether O6‐methylguanine‐DNA methyltransferase (MGMT) is altered during colorectal carcinogenesis, we performed immunohistochemical staining on 265 sporadic colorectal cancers, 113 sporadic adenomas, 33 familial adenomatous polyposis (FAP) colorectal cancers, and 93 FAP adenomas. Sixty‐seven of 265 sporadic colorectal cancer cases and five of 113 sporadic adenoma cases showed loss of MGMT expression (P < 0.001). Among FAP patients, four of 33 cancers and six of 93 adenomas showed loss of MGMT protein expression. When we compared the association between MGMT promoter hypermethylation and protein expression, almost all cases without a methylated allele were positive for the expression of MGMT. In contrast, cases with promoter methylation frequently showed loss of MGMT expression (P < 0.01). Loss of MGMT was correlated with some clinicopathological characteristics, i.e., tumor invasion (P = 0.013) and stage (P = 0.035) in sporadic colorectal cancer, and degree of atypism (P = 0.042) in sporadic adenoma. Our results show that loss of expression of MGMT occurs more frequently in cancer than in adenoma in both sporadic and FAP patients, and that loss of expression of MGMT is associated with hypermethylation of the promoter area of MGMT gene. © 2003 Wiley‐Liss, Inc.
Reaction Propagation Rates in HMX at High Pressure
Authors: Esposito Anthony P. , Farber Daniel L. , Reaugh John E. , Zaug Joseph M.
Published: April 2003

We have measured the reaction propagation rate (RPR), or deflagration rate, in octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) powder in a diamond anvil cell over the pressure range 0.7–35 GPa. Numerical simulations of the RPR of pressurized HMX were also performed for comparison to the experimental results obtained. The simulated RPR values closely approximate the observed rates at pressures up to 3 GPa, and serve as a bridge to lower‐pressure deflagration rates for HMX in the literature. However, at higher pressures the simulated RPR values deviate significantly from our experimental results. This suggests that further refinement to the computational model is required for the calculated RPR values to approach those observed at higher pressures.
QSAR and Mechanism of Action For Aquatic Toxicity of Cationic Surfactants
Authors: Roberts David W. , Costello Jayne
Published: April 2003

This paper considers the mechanism of aquatic toxicity of cationic organic compounds and the relationship of toxicity with log P (P=octanol/water partition coefficient). The rather complex log P calculation method given by Leo and Hansch for cationics is reconsidered and the underlying solvation chemistry is reinterpreted. This reinterpretation is tested by application to micellisation data for cationic surfactants. It is found that in its micellisation potential, expressed as pCMC, a cationic surfactant is similar to the anionic surfactant with the same hydrophobe. Our modifications, derived from this finding, to the log P calculation for cationics, lead to a cationics fish toxicity QSAR whose slope and intercept are close to the range commonly found for polar narcosis QSARs. The compounds included in this QSAR include 2 non‐surfactants, indicating that for cationics, as already observed for anionics and nonionics, whether a compound is a surfactant or not is irrelevant to its toxicity. That the cationics act by a polar narcosis mechanism is supported by the results of mixture toxicity studies, indicating additive joint action for mixtures of a cationic with known polar narcotics and independent joint action for a mixture of a cationic with a known general narcotic.
Advances in Quantitative Ion Character‐Activity Relationships (QICARs): Using Metal‐Ligand Binding Characteristics to Predict Metal Toxicity
Authors: Ownby David R. , Newman Michael C.
Published: April 2003

Environmental toxicologists readily adopted QSARs from pharmacology to predict organic contaminant toxicity. In contrast, models relating metal ion characteristics to their bioactivity remain poorly explored and underutilized. Quantitative Ion Character‐Activity Relationships (QICARs) have recently been developed to predict metal toxicity. The QICAR approach, based on metal‐ligand binding tendencies, has been applied successfully to a wide range of effects, species, and media on a single metal basis. In previous single metal studies, a softness parameter and the |log KOH| were among the ion qualities with the highest predictive value for toxicity.
Product ion scanning using a Q‐q‐Qlinear ion trap (Q TRAPTM) mass spectrometer
Authors: Hager James W. , Yves Le Blanc J. C.
Published: April 2003

The use of a Q‐q‐Qlinear ion trap instrument to obtain product ion spectra is described. The instrument is based on the ion path of a triple quadrupole mass spectrometer with Q3 operable as either a conventional RF/DC quadrupole mass filter or a linear ion trap mass spectrometer with axial ion ejection. This unique ion optical arrangement allows de‐coupling of precursor ion isolation and fragmentation from the ion trap itself. The result is a high sensitivity tandem mass spectrometer with triple quadrupole fragmentation patterns and no inherent low mass cut‐off. The use of the entrance RF‐only section of the instrument as accumulation ion trap while the linear ion trap mass spectrometer is scanning enhances duty cycles and results in increased sensitivities by as much as a factor of 20. The instrument is also capable of all of the triple quadrupole scans including multiple‐reaction monitoring (MRM) as well as precursor and constant neutral loss scanning. The high product ion scanning sensitivity allows the recording of useful product ion spectra near the MRM limit of quantitation. Copyright © 2003 John Wiley & Sons, Ltd.
The mystery of striated cloud heads in satellite imagery
Authors: Dixon R. S. , Browning K. A. , Shutts G. J.
Published: April 2003

Striated cloud heads are associated with some of the most extreme cases of rapid cyclogenesis. Animations of two clear examples are presented and one is interpreted in detail in the light of a Limited Area Model analysis. Six alternative dynamical explanations are considered but none satisfactorily fits all the evidence. Copyright © 2000 Royal Meteorological Society.
The Drosophila cation channel trpl expressed in insect Sf9 cells is stimulated by agonists of G‐protein‐coupled receptors
Authors: Harteneck Christian , Obukhov Alexander G. , Zobel Andrea , Kalkbrenner Frank , Schultz Günter
Published: April 2003

Structures and regulations of vertebrate channels responsible for sustained calcium elevations after hormone stimulation are largely unknown. Therefore, the Drosophila photoreceptor channels, trp and trpl, which are assumed to be involved in calcium influx, serve as model system. trpl expressed in Sf9 cells showed spontanous activity. Hormonal stimulations of calcium influx (detected by fura‐2) and of an outwardly rectifying current were observed in Sf9 cells coinfected with baculoviruses encoding trpl and various heptahelical receptors for histamine, thrombin, and thromboxane A2, all known to cause phospholipase C‐β activation in mammalian cells. Although the identity of the G‐proteins and of possible second messengers involved need to be clarified, it is clear that trpl represents a receptor/G‐protein regulated cation channel.
Conformational changes in subdomain I of actin induced by proteolytic cleavage within the DNase I‐binding loop: energy transfer from tryptophan to AEDANS
Authors: Kuznetsova Irina , Antropova Olga , Turoverov Konstantin , Khaitlina Sofia
Published: April 2003

Alteration of the actin polypeptide chain within the DNase I‐binding loop by cleavage with E. coli A2 protease or subtilisin was shown to increase the efficiency of energy transfer from tryptophan residues to AEDANS attached to Cys‐374. Analysis of structural and fluorescence data suggested that only two of four actin tryptophan residues, namely, Trp‐340 and/or Trp‐356, can be energy transfer donors. It was also found that labelling with AEDANS induces perturbations in the environment of the tryptophan residues, these perturbations being smaller in the cleaved actin. These changes are consistent with a shift of the C‐terminal segment of actin monomer upon cleavage and confirm the existence of high conformational coupling between subdomains 1 and 2 of actin monomer. We also suggest that tryptophan residues 340 and/or 356 are located in the focus of this coupling.
Plant calcium‐dependent protein kinase‐related kinases (CRKs) do not require calcium for their activities
Authors: Furumoto Tsuyoshi , Ogawa Noriyuki , Hata Shingo , Izui Katsura
Published: April 2003

In plants, calcium‐dependent protein kinases (CDPKs) make up a large family that is characterized by a C‐terminal calmodulin(CaM)‐like domain. Recently, a novel carrot cDNA clone encoding an atypical CDPK, which has a significantly degenerate sequence in the CaM‐like domain, was found and named CDPK‐related protein kinase (CRK) [Lindzen, E. and Choi, J.H. (1995) Plant Mol. Biol. 28, 785–797]. We obtained two different cDNA clones from maize which encode CRKs. For the first enzymatic characterization of CRK, a maize cDNA clone was expressed in E. coli. The recombinant protein efficiently phosphorylated casein, a conventional protein substrate. Notably, in this in vitro phosphorylation assay, the kinase activity did not require calcium as an activator. Thus, CRKs were suggested to be novel calcium‐independent protein kinases having a degenerate CaM domain, the function of which remains to be elucidated.