Publications by authors named "Ritter D"

The safety of two attenuated oral rabies vaccines was evaluated in mink and in five species of rodents which occur in the Arctic. A 0.03 ml sample of liquid vaccine was installed directly into the mouth of voles and lemmings and 0.

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C-type natriuretic peptide (CNP) has been localized to the proximal and distal nephron. In this study, we examined the distribution and regulation of the CNP receptor, guanylyl cyclase type B (GC-B), in the rat kidney. GC-B mRNA was detected most frequently in microdissected glomeruli, thin and thick limbs of the loop of Henle, and outer and inner medullary collecting ducts by reverse transcription-polymerase chain reaction (RT-PCR).

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It was recently reported that the epaxial muscles of a lizard, Varanus salvator, function to stabilize the trunk during locomotion, and it was suggested that this stabilizing role may be a shared derived feature of amniotes. This result was unexpected because it had previously been assumed that the epaxial muscles of lizards function to produce lateral bending during locomotion and that only in mammals and birds were the epaxial muscles active in stabilizing the trunk. These results and the inferences made from them lead to two questions.

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The polarized expression of guanylyl cyclase-coupled natriuretic peptide receptors, types A (GC-A) and B (GC-B), was measured in inner medullary collecting ducts (IMCD) of normal and ischemic rat kidneys, as well as in IMCD cells. Exposure of normal rat kidney medulla to an anti-GC-A antibody demonstrated a propensity of receptor staining on the cellular basal membrane. The polarization of GC-A receptors was lost in the ischemic kidney.

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The cellular distribution of guanylyl cyclase coupled natriuretic peptide receptors type A (GC-A) and type B (GC-B) was examined by immunocytochemistry in normal rat kidney, and compared with the distribution of the vacuolar H(+)-ATPase. Staining for GC-A was found in glomeruli, thin limbs of Henle's loop, cortical collecting tubule, and inner medullary collecting duct. Staining for GC-B was found in glomeruli and the same nephron sections as GC-A, with the exception of the thin limbs.

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Due to the transient transcription of the gene of erythropoietin (EPO) in response to hypoxic stimuli, localization within the cell of origin in humans has not been possible. Under acutely induced transcription of the EPO gene, through severe bleeding (hematocrit < 10%), EPO transcripts were detected within renal interstitial cells in rodents. However, by immunohistochemistry or tissue culture, human tubular epithelial cells or glomerular mesangium have been shown to produce EPO, suggesting a species difference.

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High-speed videography and muscle denervation experiments were used to quantify the feeding kinematics of Hemisus marmoratum and to test hypotheses of muscle function. The feeding behavior of H. marmoratum, which feeds on ants and termites, differs radically from that of other frogs that have been studied.

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Massive delayed hemothorax as a result of stab wounds to the internal mammary artery have not recently been reported. A patient who died after such an injury prompted a 10-year retrospective review. During that time period, 88 patients with stab wounds to the chest were identified.

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The pattern of electromyographic activity in the epaxial muscles of walking and running lizards (water monitors, Varanus salvator) was quantified with high-speed video and synchronized electromyography. Muscle denervation experiments were performed and ground reaction forces were recorded to evaluate hypotheses of muscle function. Water monitors exhibit unilateral, uniphasic activation of the epaxial muscles ipsilateral to rear limb support.

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Nine Alaskan wolves (Canis lupus) were found dead during spring and summer 1985; five of seven animals tested for rabies virus were positive. The 1985 epizootic altered annual den use patterns by wolves in northeastern Alaska, but did not appear to affect population size. We propose that rabies in arctic wolves may be more common than previously thought.

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We identified individuals whose serum contained a substance that produced falsely decreased thyroid hormone (T)-uptake values determined by the Emit (Syva) procedure. Investigation of this interference was prompted by identification of a patient with T-uptake values inconsistent with clinical assessment. IgG depletion and supplementation studies with this patient's serum suggested that the interference was due to endogenous antibodies with specificity for the thyroxine-glucose-6-phosphate dehydrogenase conjugate in the Emit T-uptake assay.

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The purpose of this research was to determine whether trappers in northern Alaska acquired immunity to rabies virus from non-bite exposures while trapping and skinning arctic foxes (Alopex lagopus). In coastal Alaska recurring epizootics presumably provide trappers ample opportunity for contact with rabid animals. Serum neutralization analyses of blood samples collected from 26 individuals were conducted.

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Maternal peripartum complications continue to be a significant problem in the United States, even among previously healthy women. The problems include peripartum bleeding, infection, hypertension, and thromboembolic disease. Primary care physicians are often called upon to treat these conditions.

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We discuss a three-dimensional sensor that combines coded illumination and triangulation. The sensor supplies the distance of ~ 250,000 object pixels (TV format) in 40 ms (one single TV frame period). Themethod is based on the following principle: a color spectrum of a white-light source is imaged onto the object by illumination from one certain direction.

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As a part of a program to screen and immunize as many Alaska Natives as possible against hepatitis B infection, hepatitis B virus seromarkers were measured in 52,022 Alaska Natives between 1983 and 1987. Hepatitis B surface antigen (HBsAg) was found in 1,603 persons (3.1%), and 7,155 persons (13.

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A pulse-coupled neural network was implemented, for the first time to our knowledge, in a hybrid electro-optical laboratory demonstration system. Dynamic coherent traveling-wave patterns were observed that repeated their spatial patterns at each locality with a period that depended on the local input pattern and strength. Coherence and periodicity were maintained far beyond the physical limits of the linking receptive fields, suggesting a new mechanism for information transmission in a network with limited local connectivity.

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Regional cerebral glucose metabolism (rCMRG1) was studied in three patients with myotonic dystrophy by positron emission tomography with 18F-2-fluoro-2-deoxy-D-glucose as the radiotracer. Clinically, all patients presented an organic personality syndrome. Impairment of rCMRG1 was found in all cortical and subcortical regions, particularly in the frontal cortex and the lentiform nucleus.

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The interaction between parasites and their animal or human hosts is one of the most interesting and important biologic phenomena. Understanding the host-parasite interplay is essential to understanding the pathogenesis of parasitic diseases and for the development of new vaccines and chemotherapy. One approach to identifying key components of the host immune response to parasites is using immunodeficient host models.

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We have identified an individual whose thyroxine (T4) concentration was undetectable with Abbott's fluorescence polarization immunoassay (FPIA) but within the reference range by radioimmunoassay or EMIT (Syva). The patient's thyrotropin, triiodothyronine, and T-uptake values were within the normal range. The T4 concentration measured by FPIA increased to normal when the immunoglobulin fraction was selectively removed from the serum.

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To date, atrial natriuretic factor (ANF) mRNA has eluded detection in the mammalian kidney, although we and others have identified ANF protein in the kidney using immunohistochemical and immunoassay techniques. Furthermore, we have demonstrated the synthesis and secretion of the ANF prohormone in the distal cortical nephron of the intact rat kidney and from rat primary cultured renal distal cortical tubular epithelial cells. In the present study, we show that the ANF gene is expressed in the kidney.

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Human papillomavirus (HPV) DNA was detected by Southern blot hybridization in cervicovaginal lavage samples from 199 of 329 (60.5%) women attending a municipal hospital colposcopy clinic. Human papillomavirus was identified in 195 of 264 (73.

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Atriopeptin (AP) is synthesized and stored in the mammalian atria as a 126 amino acid prohormone (AP126). Upon secretion, the prohormone undergoes site specific proteolysis within the atria to yield the carboxyl terminal 28 amino acid hormone (AP28). The atrial cell responsible for AP126 bioactivation has not yet been determined.

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