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D Stiller

Publications and source records attributed to D Stiller.

At least 55 records · Page 3Linked to original sources
PubMed1992

Antibody to a recombinant merozoite protein epitope identifies horses infected with Babesia equi.

Horses infected with Babesia equi were previously identified by the presence of antibodies reactive with a merozoite surface protein epitope (D. P. Knowles, Jr., L. E. Perryman, L. S. Kappmeyer, and S. G. Hennager. J. Clin. Microbiol. 29:2056-2058, 1991). The antibodies were detected in a competitive inhibition enzyme-linked immunosorbent assay (CI ELISA) by using monoclonal antibody 36/133.97, which defines a protein epitope on the merozoite surface. The gene encoding this B. equi merozoite epitope was cloned and expressed in Escherichia coli. The recombinant merozoite protein, designated equi merozoite antigen 1 (EMA-1), was evaluated in the CI ELISA. Recombinant EMA-1 bound antibody from the sera of B. equi-infected horses from 18 countries. The antibody response to EMA-1 was then measured in horses experimentally infected with B. equi via transmission by the tick vector Boophilus microplus or by intravenous inoculation. Anti-EMA-1 antibody was detected 7 weeks post-tick exposure and remained, without reexposure to B. equi, for the 33 weeks of the evaluation period. The data indicate that recombinant EMA-1 can be used in the CI ELISA to detect horses infected with B. equi.

Animals↗
PubMed1992

Liver tumors: follow-up with P-31 MR spectroscopy after local chemotherapy and chemoembolization.

The authors examined and quantified the changes observed in the phosphorus-31 magnetic resonance (MR) spectra of liver tumors after chemotherapy and chemoembolization to investigate the suitability of P-31 MR spectroscopy for follow-up. A 1.5-T unit was used before and at specific times during therapy to obtain spectra of liver tumors in 10 patients with liver metastases from colorectal carcinoma and two patients with hepatocellular carcinoma. A marked increase in inorganic phosphate and a decrease in the alpha- and beta-nucleotide phosphate portions of the spectra were observed during the first few hours after local chemotherapy or chemoembolization. Later, the phosphomonoester signals increased markedly and the phosphodiester signals decreased slightly. The effects of successful chemoembolization or local chemotherapy become apparent in the P-31 MR spectrum during the first few hours after the start of therapy. The results demonstrate that P-31 MR spectroscopy is a suitable method for follow-up. However, long-term studies are needed to determine whether it also yields prognostic information.

Carcinoma, Hepatocellular↗
PubMed1992

Susceptibility of two Rocky Mountain bighorn sheep to experimental infection with Anaplasma ovis.

In North America, the role of wild ruminants in the epidemiology of anaplasmosis has not been clearly defined. Such information is particularly meager in regard to bighorn sheep. We report the susceptibility of two Rocky Mountain bighorn sheep (Ovis canadensis canadensis) to experimental infection with a well characterized field isolate of Anaplasma ovis obtained from domestic sheep in Idaho. Both bighorn sheep developed infection resulting in severe clinical disease, with relatively high parasitemias, icterus and anemia. One animal required tetracycline therapy and responded well to treatment, while the other recovered uneventfully without treatment. Both bighorn sheep were spleen-intact, a condition that in A. ovis-exposed domestic sheep typically is associated with mild infection. The results indicate that bighorn sheep may be adversely affected if exposed to the organism in nature.

Anaplasma↗
PubMed1992

Development of Anaplasma marginale in male Dermacentor andersoni transferred from parasitemic to susceptible cattle.

The development and transmission of Anaplasma marginale was studied in Dermacentor andersoni males. Laboratory-reared male D andersoni were allowed to feed for 7 days on a calf with ascending A marginale parasitemia. The ticks were then held in a humidity chamber for 7 days before being placed on 2 susceptible calves. Anaplasmosis developed in the calves after incubation periods of 24 and 26 days. Gut and salivary glands were collected from ticks on each day of the 23-day experiment and examined with light and electron microscopy. Colonies of A marginale were first observed in midgut epithelial cells on the sixth day of feeding on infected calves, with the highest density of colonies found in gut cells while ticks were between feeding periods. The first colonies contained 1 large dense organism that subsequently gave rise to many reticulated organisms. Initially, these smaller organisms were electron-lucent and then became electron-dense. On the fifth day after ticks were transferred to susceptible calves for feeding, A marginale colonies were found in muscle cells on the hemocoel side of the gut basement membrane. A final site for development of A marginale was the salivary glands. Colonies were first seen in acinar cells on the first day that ticks fed on susceptible calves, with the highest percentage of infected host cells observed on days 7 to 9 of that feeding. Organisms within these colonies were initially electron-lucent, but became electron-dense.

Anaplasma↗
PubMed1991

Effect of pentoxiphylline on the recovery of the preserved rat liver: 31P NMR and ultrastructural studies.

Hepatic failure often occurs following transplantation. This is primarily due to cold ischemia during preservation, warm ischemia during implantation, and finally reperfusion damage after transplantation and reflow. The possibility that this ischemia and reperfusion-induced damage can be reduced by preischemic application of a xanthine derivative (pentoxiphylline) was examined using 31P NMR spectroscopy and electron microscopy (EM) studies of bioenergetic and ultrastructural changes in oxygenated erythrocyte-perfused rat livers. EM illustrated that the hepatocytes and the mitochondria appeared to be relatively unaffected by cold preservation of the liver, whereas the endothelial cells lining the sinusoids became disrupted. After reperfusion, NMR spectroscopy showed a partial recovery of ATP levels, and EM indicated progressive mitochondrial injury. This progressive injury to the liver was probably due to endothelial cell damage which resulted in microcirculatory malfunction and free radical formation during reperfusion. Pentoxiphylline pretreated livers showed better preservation of the cell morphology and exhibited better ATP recovery than untreated livers. Pentoxiphylline is known to prevent the loss of precursors of ATP resynthesis by inhibiting AMP dephosphorylation during ischemia and improves the microcirculation via vasodilatory properties following ischemia. Thus, it is concluded that pentoxiphylline may ameliorate ischemia-induced cell damage during transplantation.

Adenosine Monophosphate↗
PubMed1991

Demonstration of glomerular DPP IV activity in kidney diseases.

Dipeptidylpeptidase IV (DPP IV) activity has been found in glomeruli of the rat and other previously investigated animal species, but has not been detected in the glomeruli of the normal human kidney. Under pathological conditions, enzyme activity may be registered. Following investigations on 155 human renal biopsies using polyclonal antisera against IgG, IgA, IgM, C3C, Fibrinogen, and DPP IV, we found glomerular enzyme activity in 43 cases of various histological diagnoses, but never in normal renal tissue. Identical results could be found by the Gly-Prol-beta-MNA substrate reaction. The localization of glomerular enzyme activity in capillary walls could not be definitely determined, possibly enzyme activity occurs in podocytes. Correlation of glomerular DPP IV activity to the deposition of immunoglobulins was not found. Nevertheless, the appearance of DPP IV in human glomeruli seems to be in correlation with some clinical findings, e.g. hypertension. The importance of DPP IV activity in pathohistologically changed glomeruli of human kidney is definitely large, but needs further investigation.

Dipeptidyl Peptidase 4↗
PubMed1991

Pathogenesis of transplantation arteriopathy. Myointimal cells express HLA-DR antigens during rejection.

Arteries were investigated ultrastructurally in material from 40 needle and wedge biopsies of renal allografts, and immunohistochemically in another 10 cases with signs of chronic obliterative transplantation arteriopathy. In the early biopsies, but even in the control kidneys, thin extensions of the smooth muscle cells of the media were observed, which were in direct contact with the endothelial cells through the lamina elastica interna. These extensions may contain receptors mediating endothelial noxae to the smooth muscle cells thus initiating their proliferation, migration to the intima presumably begins in the early post-transplant period and continues until the lumen is occluded. Concomitantly, inflammatory cells (mainly macrophages, with a smaller number of CD4 and CD8-positive T lymphocytes) invade the intima. The proliferating myointimal cells, possibly having become HLA-DR-positive, may behave as antigen-presenting cells, enhancing the anti-graft immune response further, and aggravating the arterial injury.

Cell Movement↗
PubMed1990

Comparison of a DNA probe, complement-fixation and indirect immunofluorescence tests for diagnosing Anaplasma marginale in suspected carrier cattle.

Most estimates of the prevalence of anaplasmosis have been based on serologic data using the complement-fixation (CF) and/or card agglutination tests. Since these tests are considered to be only about 50 percent reliable for detecting carrier cattle in enzootically stable herds, the need for more sensitive diagnostic tests is widely recognized. The objective in the present study was to compare the sensitivity of the CF test with that of the indirect immunofluorescence (IIF) test and a recently developed DNA probe in determining the prevalence of Anaplasma marginale infection in cattle from an enzootic area. The study herd consisted of 52 8-month-old steers and 13 3-year-old cows of mixed beef breed. All cattle were initially tested for this comparative purpose. All but one animal (one that was a positive reactor as assessed by all three tests, and served as a positive control), were treated with long-acting oxytetracycline in an attempt to clear any carrier infections. Each animal was then retested at 1 month and 2 months post-treatment (PT), in an effort to determine if the DNA probe could be used to evaluate the effectiveness of the drug. Six of the 65 (9.2%) initial serum samples were CF positive. In contrast, 60 (92.3%) and 64 (98.5%) of the samples were positive as assessed with the IIF test and the DNA probe, respectively. The DNA hybridization reactions varied in intensity within the sample population indicating different individual levels of infection. The DNA probe hybridized with two samples taken at 1 month PT, and with two different samples taken at 2 months PT. The mean IIF titers were reduced at both the 1 month and 2 month sampling times. These results suggest that the drug did not eliminate infections in all cattle. Some may have been cleared, but, in any event, the drug did reduce the level of infections below the sensitivity of the DNA probe and interrupted continuity of stimulation of antibody. Therefore, the DNA probe and the IIF test appear to be considerably more sensitive in detecting carrier infections than the CF test, and should be considered in future epidemiologic studies.

Anaplasma↗
PubMed1990

Sarcoplasmic reticulum (SR) Ca2(+)-ATPase as a marker of muscle cell differentiation: immunohistochemical investigations of rhabdomyosarcomas and enhancement of the immunostaining after sodium methoxide pretreatment.

An immunocytochemical investigation of sarcoplasmic reticulum (SR) Ca2(+)-ATPase (SR-Ca-ATPase) was performed on formalin-fixed paraffin-embedded specimens of different types of rhabdomyosarcomas such as variants of embryonal and pleomorphic forms. Immunostaining frequency of tumours using SR-Ca-ATPase was compared with that of traditionally used muscle specific markers myoglobin, and desmin. Utilizing the possible cleaving of ester bounds sodium methoxide pretreatment was found to be very effective in enhancement of SR-Ca-ATPase immunostaining reaction. In 11 of 15 tissue specimens of 5 cases round shaped and elongated rhabdomyoblasts with definite cytoplasm exhibited positive immunoreactions with all of the polyclonal antibodies tested, using the streptavidin-biotinylated peroxidase complex (S-ABC-method). In formalin-fixed and paraffin-embedded material of 2 cases of undifferentiated rhabdomyosarcomas composed of small round tumour cells with scanty cytoplasm pretreatment with sodium methoxide induced the immunostaining of SR-Ca-ATPase. After that pretreatment a staining of the paranuclear cytoplasm occurred in many of these undifferentiated tumour cells. In these 2 cases, neither myoglobin nor desmin antibodies could react. However, when frozen sections of one of the poorly differentiated tumours were used monoclonal and polyclonal desmin antibodies reacted immunocytochemically in all of the small cells. Sodium methoxide induced or enhanced SR-Ca-ATPase immunocytochemical reaction can be a further addition to the diagnosis of rhabdomyosarcomas in formalin-fixed paraffin-embedded sections, even when desmin antibody fails to react.

Antibodies, Monoclonal↗
PubMed1990

[Magnet resonance spectroscopy of tumor-bearing rat livers: magnetite particles as an aid in volume selection].

Magnetite, an RES-specific contrast medium, has been used in animal experiments and in a few patients for MRI of the liver. We examined the use of magnetite particles for 31P-MR spectroscopy using a phantom, and perfused tumour-bearing rat livers and liver tumours in living rats. As expected, there is homogeneous uptake of the magnetite in normal liver leading to extinction of the signal when one uses suitable spectroscopic parameters. Since the ferrite particles do not penetrate non-hepatic tissue, such as metastases, a signal remains uniquely from the tumour and this can be used, for instance, for following the effect of cytostatic therapy. The use of magnetite produces a selective effect and interference from normal liver is thereby avoided. Multiple lesions with irregular configuration can be examined simultaneously by this method. It remains to be seen how useful the application of magnetite will be for avoiding motion artifacts during spectroscopy.

Animals↗
PubMed1990

[The effect of nutritional status on the 31P MR spectrum of the normal liver].

Previous investigations in animal and human liver spectroscopy revealed a strong effect of metabolic activity on the 31P-spectra of the liver. This study examined the influence of a standardised meal on the liver spectra of healthy volunteers. The measurements were performed at 1.5 T (Magnetom, Siemens). The results show that the metabolic condition has a strong effect on the 31P MR liver spectra. The changes are of the same order of magnitude as those described in spectra of focal or diffuse liver diseases. This indicates that identical metabolic conditions are necessary for measuring liver spectra of volunteers and patients, especially in follow-ups.

Adult↗
PubMed1990

Application of biotechnology for the diagnosis and control of ticks and tick-borne diseases.

Current and potential applications of biotechnology to detect and control anaplasmosis, bovine babesiosis, cowdriosis, and theileriosis are examined in the light of dramatic advances in molecular biology. Vaccines and the diagnostic use of nucleic acid probes, restriction fragment length polymorphisms, and monoclonal antibodies are discussed in detail, as are novel genetic methods for increasing the resistance of livestock to disease. Strategies are suggested for using molecular and non-molecular approaches in integrated programmes for controlling haemoparasitic diseases of livestock.

Anaplasmosis↗
PubMed1990

[Diagnosis of lysosomal storage diseases. Pathomorphologic and biochemical possibilities].

Optical light and electron microscopy were used in studies into two cases of infantile GM2-gangliosidosis. The results are reported in this paper. The correlation has been evident between histological and ultrastructural findings. Reliable delimitation between two different variants of infantile GM2-gangliosidosis was achieved through biochemical investigation of postmortally cultured skin fibroblasts. A classical form with isolated hexosaminidase-A defect (Tay-Sachs disease) was distinguished from a second variant with complete defect of both isoenzymes of hexosaminidase (Sandhoff's disease). Biochemical investigation of postmortally cultured fibroblasts today has become indispensable to enlargement of autopsy findings from other storage diseases, as well.

Brain↗
PubMed1990

[Infantile cortical hyperostosis (Caffey-Silverman syndrome). Histologic, histochemical and electron microscopic studies].

Infantile cortical hyperostosis, also known as Caffey's disease or Caffey-Silverman syndrome, is an uncommon clinico-pathological lesion of unknown etiology and uncertain histogenesis. One of the most striking features is the early age of patients at the onset of the disease, showing swelling of the soft tissues overlaying bones, hyperirritability, and, subsequently, periosteal new bone production. The natural history of the disease proves to be self-limiting. Multiple areas are involved in the majority of cases. These polyostic forms are easily clinically diagnosed. But in rare monostic presentations, especially manifestations in the scapular region, there may be a great suspicion of a malignant tumor. Histologically, such lesion may also be misdiagnosed as a malignant neoplasm because of the great variety of microscopic appearances. This study was conducted into 5 cases (biopsies from one male and four female infants, 6 weeks to 4 months of age) to characterize the histological variability in the natural course of the disease. Electron microscopical investigations were additionally performed on two cases. Histologically, the process corresponds to typical ossifying periostitis. Three phases can be distinguished according to the main histological characteristics: 1. Acute inflammatory and proliferating phase; 2. Osteogenic phase; 3. Phase of remodelling. The first phase is characterized by a loss of periost, areas showing proliferation of fibroblast-like cells, and by edema of surrounding musculature. Infiltration by leucocytes was occasionally observed and was accompanied by micro-abscesses. The osteogenic phase was characterized by formation of woven bone. Ultrastructurally proliferations of osteogenic mesenchyma were found and resulted in typical mineralization patterns with matrix vesicles and interfibrillar depositions of hydroxyapatite crystals. Calcification of mitochondria was also detected. Viruses could not be observed. Only thread-like structures were found in the nuclei. At first interpretation, they appeared to be pathological protein depositions. However, further investigations will be necessary to elucidate their genesis. The pathogenesis is discussed. Biopsy still remains indicated in cases of an unclear course of monostic disease.

Bone and Bones↗
PubMed1990

[Pathomechanism of the development of chronic obliterative transplantation arteriopathy in human kidney allografts].

Authors examined cells participating in intimaproliferation in transplantation arteriopathy ultrastructurally in needle and wedge biopsy material from 40 transplanted kidneys, and immunohistochemically in 10 cases. In early biopsies--even in two control kidneys--it could be observed that the smooth muscle cells of media are in direct contact with endothel cells by their small processes. Processes can fulfil a receptor function and can transmit endothel noxa to smooth muscle cells. Smooth muscle cells of media react to endothel damage caused by rejection with migration to intima and during this period they are transformed to myofibroblasts (myointimal cells). In the mean time inflammatory cells (mainly macrophages, helper and cytotoxic cells in lower number) from the lumen infiltrate the intima, and mediators, enzymes released from them can inspire smooth muscle cells to further proliferation, migration to intima and transformation to myofibroblast. To effect of mediators (gamma interferon) released from inflammatory cells, the myointimal cells during rejection will press out 2nd class transplantation antigens (HLA-DR), and as vicious circle it further aggravates immune reply to graft, causing vascular damage, intimaproliferation.

Chronic Disease↗