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R C Thompson

Publications and source records attributed to R C Thompson.

At least 469 records · Page 26Linked to original sources
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Albendazole: a more effective antigiardial agent in vitro than metronidazole or tinidazole.

The effects of albendazole were assessed against Giardia duodenalis in vitro and compared with those of tinidazole and metronidazole. Trophozoite morphology, adherence and viability were markedly affected by albendazole, to a far greater extent than by either metronidazole or tinidazole. The results of this study, and in particular the superior potency of albendazole in vitro, are discussed with respect to its potential value as a new approach to the chemotherapy of giardiasis.

Albendazole↗
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RAPD (random amplified polymorphic DNA) analysis of Giardia DNA and correlation with isoenzyme data.

Fourteen Giardia duodenalis isolates were examined using the RAPD (random amplified polymorphic deoxyribonucleic acid) technique. Simple reproducible polymorphisms were generated using 3 different RAPD primers. The results generated by each primer were very similar and were significantly correlated with each other. These data were then compared to existing isoenzyme electrophoresis data on the same isolates. The RAPD data divided the isolates into 10 groupings or rapdemes while the isoenzyme data divided them into 10 similar zymodemes. Both methods grouped 4 isolates (BAH42, BAH44c9, BAH12c9 and BAH39c7), which comprised a phenotypically heterogeneous assemblage with respect to growth rate and metabolism, into similar groupings. The 2 methods were significantly correlated (P < 0.001). It will therefore be possible to use RAPD for the characterization of isolates of Giardia, and other parasites such as Cryptosporidium, which are refractory to cultivation in vitro.

Animals↗
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A field and laboratory evaluation of a commercial ELISA for the detection of Giardia coproantigens in humans and dogs.

A capture enzyme linked immunosorbent assay (CELISA) was evaluated for its ability to detect Giardia coproantigens in the faeces of humans and dogs in the Perth metropolitan area and Aboriginal communities in Fitzroy Crossing, Western Australia. Using zinc sulphate flotation and light microscopy, Giardia cysts and/or trophozoites were observed in 8 of 57 (14%) human stool samples from Perth and 21 of 55 (38%) stool samples from Fitzroy Crossing, after 2 separate examinations. Analysis of diagnostic sensitivity using the ELISA revealed that coproantigens were detected in all 29 human samples (100%) in which Giardia cysts and/or trophozoites were also present. Coproantigens were detected in one further sample from Perth and in 3 samples from Fitzroy Crossing in which no Giardia cyst or trophozoite was observed. The specificity of the test, as defined using Fitzroy Crossing samples free from Giardia, was 91%. The assay did not cross-react with Giardia-free stool samples containing Hymenolepis nana, Entamoeba coli, E. hartmanni, Chilomastix mesnili or Ancylostoma duodenale. Giardia cysts and/or trophozoites were also observed in 11 of 32 dog faecal samples (34%) in Perth and 11 of 29 dog samples (38%) in Fitzroy Crossing, after one zinc sulphate examination. The sensitivity of the ELISA for dogs was 64% and 55% for Perth and Fitzroy Crossing specimens respectively. The specificity was 95% when Fitzroy Crossing samples were used. Other parasites observed in Giardia-free faecal samples from dogs which did not produce a positive reaction with the kit were Ancylostoma caninum, Sarcocystis sp. and Isospora sp.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
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Delta opioid receptor mRNA distribution in the brain: comparison to delta receptor binding and proenkephalin mRNA.

The recent cloning of the mouse delta opioid receptor (Evans et al., 1992; Kieffer et al., 1992) has demonstrated it to be a member of the seven transmembrane G-protein coupled family of neurotransmitter receptors. The present study describes the cellular localization in the central nervous system (CNS) of an mRNA encoding this receptor and compares it with the distribution of delta receptor binding and proenkephalin mRNA using a combination of in situ hybridization and receptor autoradiographic techniques. Delta receptor mRNA was visualized with a cRNA probe (472-903 bp) corresponding to transmembrane domains III-VI of the receptor, while proenkephalin mRNA was labeled with a cRNA probe to exon 3 (139-832 bp). A high level of correspondence was observed between the distribution of delta receptor mRNA and delta receptor binding as defined by the selective ligand [3H]D-Pen2-Pen5-enkephalin. Delta receptor mRNA and binding were expressed in the neocortex, caudate-putamen, nucleus accumbens, olfactory tubercle, diagonal band of Broca, amygdala and the nucleus of the solitary tract. Discrepancies in the distribution of delta receptor mRNA and binding in the olfactory bulb, hippocampus, globus pallidus and substantia nigra pars reticulata, may in part be due to differential receptor synthesis and transport. These results are discussed in relation to the distribution of proenkephalin mRNA and how this may affect our understanding of opioid circuitry in the CNS.

Animals↗
PubMedDate not supplied

The distribution of dopamine D2 receptor heteronuclear RNA (hnRNA) in the rat brain.

Conventional in situ hybridization methods have been useful in characterizing the anatomical distribution of cells in the central nervous system that express dopamine D2 receptor mRNA. However, due to the large size of the D2 mRNA pool, this method may be insensitive to changes in D2 gene transcription. We have developed a method of hybridizing a 35S-labelled cRNA probe to an intron in the D2 receptor gene in order to measure the amount of primary transcript or heteronuclear RNA (hnRNA) in D2-expressing cells. Introns are found uniquely in hnRNA and are thought to be short-lived intermediates. Thus, monitoring introns could represent a more direct measure of D2 gene transcription. The anatomical distribution of the D2 hnRNA is similar to the distribution of D2 mRNA in the rat brain. D2 heteronuclear RNA was found in the nuclei of cells in the caudate putamen, nucleus accumbens, hippocampus, olfactory tubercle, substantia nigra, ventral tegmental area, and zona incerta. Other regions that contain D2 mRNA, but do not demonstrate intronic signal, include the globus pallidus, prefrontal, cingulate, entorhinal, and piriform cortex, septum, and amygdala. However, these areas have low amounts of D2 mRNA and may contain levels of D2 hnRNA that are below detection. Heteronuclear RNA quantitation by solution hybridization followed by RNase protection was performed on striatum, substantia nigra, cerebral cortex, hippocampus, hypothalamus, and pituitary using a D2 intron 7/exon 8 border probe. These results corroborate the distribution of hnRNA revealed with intronic in situ hybridization. In addition, protection assays were able to detect hnRNA in areas that express low levels of D2 like the cortex, hippocampus and hypothalamus. hnRNA/mRNA ratios calculated from intron/exon border probe protection assays were not equivalent for all the tissue areas studied, indicating that transcription and/or hnRNA half lives may differ between tissues that express D2 receptors. The combined use of intronic in situ hybridization and intron/exon border protection assay as an index of D2 gene transcription and RNA processing provides more information than measuring the mRNA pool alone. It may also prove to be a more useful measure of gene regulation, allowing for evaluation of gene responses to acute treatments.

Animals↗
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Ninety-day follow-up of patients in the emergency department with chest pain who undergo initial single-photon emission computed tomographic perfusion scintigraphy with technetium 99m-labeled sestamibi.

BACKGROUND: Patients in the emergency department with typical chest pain and a normal or nondiagnostic electrocardiogram have a 10% to 20% risk of nonfatal myocardial infarction. These patients can be stratified into groups of very low and very high risk for inpatient adverse cardiac events on the basis of initial 99mTc-labeled sestamibi single-photon emission computed tomographic (SPECT) perfusion imaging performed during symptoms. However, the intermediate or posthospital discharge prognosis of such patients has not been reported. METHODS AND RESULTS: Patients (n = 150) with typical chest pain (based on a semiquantitative chest pain questionnaire) and a normal or nondiagnostic electrocardiogram underwent injection of 15 to 45 mCi 99mTc-labeled sestamibi injected during symptoms. Ninety-day follow-up history (telephone questionnaire and review of medical records) was obtained in 140 patients, and follow-up electrocardiography was performed in 72 patients. Cardiac events (death, nonfatal myocardial infarction, thrombolysis, percutaneous transluminal coronary angioplasty, or coronary artery bypass grafting) occurred before hospital discharge in 33 patients (18%), and these patients were excluded from further analysis. At follow-up, two (8%) of 25 patients with an abnormal initial scintigram and none of 87 patients with a normal scan had cardiac events (p = 0.008). CONCLUSIONS: In patients with typical angina and a normal or nondiagnostic electrocardiogram, initial SPECT scintigraphy allows early accurate risk stratification. The previously observed excellent inpatient prognosis of patients with a normal scintigram appears to extend for at least 90 days of follow-up. These observations may provide a rational basis for safe and cost-effective outpatient evaluation of selected patients in the emergency department with typical angina, a normal or nondiagnostic electrocardiogram, and a normal initial 99mTc-labeled SPECT perfusion scintigram performed during symptoms.

Angina Pectoris↗
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Intracranial paracrine interleukin-2 therapy stimulates prolonged antitumor immunity that extends outside the central nervous system.

To explore the potential efficacy of local cytokine delivery against tumors in the central nervous system (CNS), C57BL6 mice were simultaneously given intracranial injections of tumor challenge and of irradiated B16F10 melanoma cells transduced to secrete interleukin-2 (IL-2). Intracranial IL-2 therapy generated antitumor responses capable of extending the survival of animals that received simultaneous intracranial tumor challenge either locally or at distant sites in the brain. Nontransduced melanoma cells had little effect. Animals that survived intracranial IL-2 therapy and tumor challenge showed prolonged survival compared with controls when challenged with a second tumor dose 70 days after initial treatment. In addition, animals that rejected intracranial tumors were also protected from tumor growth upon rechallenge at sites outside the CNS (i.e., subcutaneous tumor challenge). Conversely, identical or 10-fold larger doses of IL-2-transduced cells administered by subcutaneous injection failed to generate protection against intracranial tumor challenges. Elimination of T-cell and natural killer (NK) subsets using gene knockout mice and antibody-depletion techniques demonstrated that NK cells were most important for the initial antitumor response, whereas CD4+ T-cells were not necessary. These studies demonstrate that local IL-2 therapy in the brain not only generates an immediate local antitumor immune response, but also establishes long-term immunologic memory capable of eliminating subsequent tumor challenges within and outside of the CNS. Furthermore, the antitumor response to paracrine IL-2 in the brain differed significantly from that in the flank, suggesting that the intrinsic CNS cells involved in initiating immunity within the brain have different cytokine requirements from their peripheral counterparts.

Adjuvants, Immunologic↗
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The role of trochanteric osteotomy in total hip replacement.

In a study of 225 hip replacements, 126 had trochanteric osteotomy and 99 did not. Trochanteric osteotomy was found to be invaluable in approaching the difficult, previously operated hip. Even though 81 hips without trochanteric osteotomy had no complications directly related to the operative technique, 19 had significant operative problems. Hips with fixed flexion or external rotation contractures preoperatively presented technical difficulties and postoperative problems avoidable only by trochanteric osteotomy. Complications are encountered with and without osteotomy and various indications for osteotomizing the greater trochanter through a lateral approach to the hip are reviewed on the basis of experience with 184 patients with an average age of 61 years.

Adult↗
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Intralesional infiltration of corticosteroids in localized Langerhans' cell histiocytosis.

The approaches to treatment of Langerhans' cell histiocytosis (LCH) have been as varied as the clinical presentation of the disease. The clinical course of localized LCH of bone is generally benign, and it tends to heal spontaneously in a period of months to years. If treatment is required, the disease can be controlled by local measures such as surgical curettement, low-dose irradiation, or intralesional infiltration with corticosteroids. We reviewed 15 children treated with intralesional infiltration of corticosteroids, either primarily for disease of bone (8 patients) or as adjunctive therapy for disseminated LCH (7 patients). Two patients developed complications as a result of this treatment method.

Adrenal Cortex Hormones↗
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Current concepts in management of cervical spine fractures and dislocations.

In order to manage the patient with a cervical spine injury, one must be familiar with a diagnostic classification of these injuries and be able to apply this classification to the individual patient. When a cooperative effort is made between orthopedists and neurosurgeons, we have found that most cervical spine injuries can be managed successfully without operative means using Cheshire's classification for predicting late instability. We have been able to identify (1) those patients who would not substantially benefit from surgical intervention; (2) certain types of injuries where relative indications for surgery may be considered; and (3) we have confirmed the danger and risk of early operative intervention following cervical spine trauma in the neurologically damaged spinal cord.

Athletic Injuries↗
PubMedDate not supplied

[Efficacy evaluation of epsiprantel (Cestex) against Echinococcus mutilocularis in dogs and cats].

Helminth-free dogs and cats were experimentally infected with protoscoleces of Echinococcus multilocularis and used in controlled trials for efficacy evaluation of the cestodicide epsiprantel. In two separate trials each 4 dogs were treated at day 20 post infection (p.i.) with average oral dosages of 5.1 (4.9-5.3) and 5.4 (5.2-5.8) mg/kg body weight (b.w.) epsiprantel, respectively, and necropsied at day 24 p.i. Among each 4 dogs of the two untreated control groups all animals were infected and had high intestinal worm burdens with averages of 33.575 and 100.725 E. multilocularis specimens per animal (individual worm burdens in group Ib 59,500-149,800, group IIb 20,500-43,200); in the two groups of treated dogs the average worm burdens were reduced by 99.6 and 99.9%. Among 8 treated dogs 4 were helminth-free, the other 4 had residual worm burdens (10-70 in 3 dogs, 1480 in 1 dog). In each 5 cats single oral treatments with average doses of 2.7 (2.7-2.8) and 5.5 (5.5-5.5) mg/kg b.w. epsiprantel were 100% effective against E. multilocularis 20 days p.i. and eliminated the worm burdens from all 10 animals. In the untreated group of 5 cats the average worm burden was 2864 per animal (individual worm burdens 20-6830). Side effects of the drug treatment were not observed. The results of the study show that in single therapeutic dosages recommended by the producer (dogs 5.5 mg, cats 2.75 mg/kg b.w.) epsiprantel eliminates E. multilocularis to over 99% or completely, but residual worm burdens may persist in some animals.

Animals↗