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D Frost

Publications and source records attributed to D Frost.

At least 37 records · Page 2Linked to original sources
PubMed1997

Advances in the molecular genetic analysis of the flax-flax rust interaction.

The L6 and M rust-resistance genes, representing two of the five rust-resistance gene loci in flax (Linum usitatissimum), have been cloned. The molecular data are fully consistent with earlier genetic data: the L locus is a single gene with multiple alleles expressing different rust resistance specificities, and the M locus is complex, containing an array of about 15 similar genes. Thus, while L6 and M resistance genes have 86% nucleotide identity, their locus structure is very different. These genes encode products belonging to the nucleotide binding site-leucine-rich repeat class of disease-resistance proteins. Analysis of alleles from the L locus and chimeric genes is providing evidence suggesting that important specificity determinants occur in the C-terminal half of the proteins, the region containing the leucine-rich repeats. The isolation and characterization of the rust (Melampsora lini) avirulence genes that correspond to the cloned rust-resistance genes is one of the major challenges remaining to the understanding of this system.

Journal Article↗
PubMed1996

Immunogenicity and efficacy against lethal aerosol staphylococcal enterotoxin B challenge in monkeys by intramuscular and respiratory delivery of proteosome-toxoid vaccines.

Staphylococcal enterotoxin B (SEB), a primary cause of food poisoning, is also a superantigen that can cause toxic shock after traumatic or surgical staphylococcal wound [correction of would] infections or viral influenza-associated staphylococcal superinfections or when aerosolized for use as a potential biologic warfare threat agent. Intranasal or intramuscular (i.m.) immunization with formalinized SEB toxoid formulated with meningococcal outer membrane protein proteosomes has previously been shown to be immunogenic and protective against lethal respiratory or parenteral SEB challenge in murine models of SEB intoxication. Here, it is demonstrated that immunization of nonhuman primates with the proteosome-SEB toxoid vaccine is safe, immunogenic, and protective against lethal aerosol challenge with 15 50% lethal doses of SEB. Monkeys (10 per group) were primed i.m. and given booster injections by either the i.m. or intratracheal route without adverse side effects. Anamnestic anti-SEB serum immunoglobulin G (IgG) responses were elicited in all monkeys, but strong IgA responses in sera and bronchial secretions were elicited both pre- and post-SEB challenge only in monkeys given booster injections intratracheally. The proteosome-SEB toxoid vaccine was efficacious by both routes in protecting 100% of monkeys against severe symptomatology and death from aerosolized-SEB intoxication. These data confirm the safety, immunogenicity, and efficacy in monkeys of parenteral and respiratory vaccination with the proteosome-SEB toxoid, thereby supporting clinical trials of this vaccine in humans. The safety and enhancement of both bronchial and systemic IgA and IgG responses by the proteosome vaccine delivered by a respiratory route are also encouraging for the development of mucosally delivered proteosome vaccines to protect against SEB and other toxic or infectious respiratory pathogens.

Aerosols↗
PubMed1994

(1,3) beta-Glucan synthase activity of Neurospora crassa: identification of a substrate-binding protein.

(1,3)beta-Glucan synthase activity from the filamentous Ascomycete Neurospora crassa was purified 1300-fold to a specific activity of 14,000 nmol glucose incorporated/min per mg protein. Hyphae were disrupted and crude membrane fractions obtained by high-speed centrifugation. Membrane fractions were extracted with Tergitol NP-40 and a second high-speed particulate fraction was obtained. Enzyme activity was solubilized with (3-((3-cholamidopropyl)dimethylammonio)-1-propanesulfonate and octyl-beta-D-glucoside from Tergitol-extracted membrane preparations. Solubilized enzyme activity was purified by product entrapment and recovered by low-speed centrifugation through a layer of sucrose. SDS-PAGE analysis revealed 2 proteins of 165 and 100 kDa as likely candidates for subunits of the (1,3)beta-glucan synthase enzyme complex. 5-Azido-[32P]UDP-glucose was photo-crosslinked to UDP-glucose-binding proteins in each fraction of the purification procedure. Autoradiograms of SDS-PAGE gels revealed a single protein of 165 kDa enriching with enzyme activity and labeling with the substrate analog. Photoincorporation of 5-azido-[32P]UDP-glucose by the 165 kDa protein was competed by 0.25 mM UDP-glucose (80%) and TDP-glucose (65%) while ADP-glucose (27%), CDP-glucose (36%), and GDP-glucose (8%) where less effective. These results were similar to in vitro inhibition of enzyme activity by the same compounds. These data strongly suggest that the 165 kDa protein is a substrate-binding subunit of (1,3)beta-glucan synthase.

Carrier Proteins↗
PubMed1994

[Carotid artery wall changes in young type-1 diabetics. The ultrasonic diagnosis of early arteriosclerosis].

In a prospective study high-resolution ultrasonography was used to document any early carotid-artery wall changes (intima-media thickening; plaques), in 165 type I diabetics up to the age of 40 years (66 males, 99 females; mean age 27.5 +/- 6 years; duration of diabetes > 1 year). In two control groups (group 1: 40 with type I diabetes of up to one year's duration; group 2: 20 healthy subjects) the mean intima-media thickness was 0.50 +/- 0.05 and 0.51 +/- 0.06 mm, respectively (maximal value 0.6 mm). In the patients with a longer duration of diabetes it was significantly higher at 0.56 +/- 0.11 mm (P < 0.001). Of the 165 patients with a diabetes duration of more than 1 year, 134 had normal intima-media wall thickness (< 0.6 mm, mean 0.52 +/- 0.07 [group A]), in 15 (group B) it was 0.75 +/- 0.06 mm, and in 16 (group C) there were plaques with a wall thickness of 0.67 +/- 0.15 mm. The incidence of nephropathy and hypertension or hypercholesterolaemia (only in group C) was significantly higher in groups B and C than A (P < 0.01). It is thus clear that these consequential or associated diseases go together, in young type I diabetics, with an increased risk of early arteriosclerosis.

Adult↗
PubMed1989

Temperature and cardiovascular deaths in Montreal.

The incidence of mortality from myocardial infarction over a 2-year period in Montreal is examined in relation to temperatures and snowfall. Mortality is seen to increase with deviations from seasonally determined thermally neutral conditions, although compared to observations of a parallel study in subtropical Brisbane, death rates are lower with similar falls in temperature. In Montreal, mortality is also seen to increase with snow during the previous day. During anomalous cold spells death frequencies decrease, a phenomenon interpreted as the behavioural thermoregulatory process of cold avoidance.

Cold Climate↗
PubMed1989

Myopathic changes in diaphragm of rats fed pyridostigmine bromide subchronically.

To determine if alterations in muscle morphology occur after subchronic oral administration of pyridostigmine bromide, rats were fed 90 mg/kg continuously in meal and examined at 1, 2, 4, 7, and 15 days. Within the first day, cholinesterase activity was reduced by 87% and remained inhibited by 74-91% for the entire course of the feeding. Light microscopy demonstrated that by the first day approximately 1 in 100 myofibers was shrunken and contained centralized nuclei. Electron microscopic examination showed that while presynaptic areas of neuromuscular junctions were relatively unaffected by this dose, postsynaptic areas invariably showed maximal changes. Ultrastructural alterations included disruption of myofilaments, mitochondrial changes consistent with accumulation of calcium, and nuclear alterations. These effects appeared not to be cumulative and were greatly diminished by 15 days even under constant drug administration and inhibition of cholinesterase activity. We conclude that subchronic feeding of pyridostigmine bromide induces primarily myopathic rather than neurogenic changes in the diaphragm and that some mechanism of accommodation may be activated that minimizes continued muscle injury.

Animals↗
PubMed1989

Spinal cord tumor.

Explore the source record for details and available documents.

Anesthesia, General↗
PubMed1987

The assessment of patients' distress in genito-urinary medicine clinics.

A sample of patients attending the clinic of a Department of Genito-Urinary Medicine in London completed The General Health Questionnaire, The Illness Behaviour Questionnaire and The Illness Concern Questionnaire. The doctor whom they consulted was also asked to complete rating scales regarding each patient's level of psychological disturbance. Thirty-eight percent of patients scored highly on the GHQ, indicating possible psychological disturbance. However, only one in five of such 'cases' were also rated by the doctor as possibly psychologically disturbed. A number of social variables are examined that may facilitate or limit the communication of psychological distress. No evidence of labelling of deviant groups is found. However, both the sample in general and specific sub-groups in particular scored highly on scales of hypochondriasis and distress in relation to health and such characteristics appeared relevant to doctors' judgements of patients' psychological states.

Adult↗
PubMed1987

Psychological disturbance and illness behaviour in a clinic for sexually transmitted diseases.

Patients attending a sexually transmitted diseases (STD) clinic were asked to complete the General Health Questionnaire and the Illness Behaviour Questionnaire. Data were collected from 852 patients. One-third of the sample were found to score positively on the GHQ, indicating possible psychological disturbance. Women were more likely than men to score positively on the GHQ. On the General Hypochondriasis scale of the IBQ the sample's scores were higher than any other normative data except those obtained from psychiatric in-patients. On this scale homosexual and bisexual males scored significantly higher than heterosexual males. It is argued that the IBQ draws attention to important dimensions of psychological distress in STD clinics.

Adult↗
PubMed1986

Survey of psychological disturbance in patients attending a sexually transmitted diseases clinic.

A survey of psychological disturbance was conducted in a sexually transmitted disease (STD) clinic, using the general health questionnaire, the Crown-Crisp experiential index, and the illness concern questionnaire. Of 381 patients who completed the questionnaire, 158 (43%) had general health questionnaire scores indicating that they were psychiatric cases. Psychological disturbance was more common in women. The association between general health questionnaire caseness and patients' reports of concerns and worries about illness in relation to their presenting complaint was significant. The Crown-Crisp experiential index scores of cases were lower than those characteristic of patients attending psychiatric clinics, and much of the psychological disturbance found by this and other surveys of STD clinics may therefore represent distress in relation to the presenting problem. Of the 381 patients, 14 (4%) appeared to have an abnormal or unwarranted level of distress in relation to their presenting complaint.

Adult↗
PubMed1985

The recognition of psychological disturbance in a sexually transmitted diseases clinic.

This study examined the rate of psychological disturbance in a series of new patients attending a clinic for sexually transmitted diseases. Forty three per cent of patients were identified as probable psychiatric cases by the General Health Questionnaire. Medical staff in the clinic were asked to assess patients' level of psychological disturbance. Disagreement between GHQ and doctors' ratings occurred in 41% of patients. Some patient and doctor characteristics were examined that might be associated with disagreement, and the results are discussed in terms of possible social--psychological influences upon doctors' recognition of psychological disturbance.

Adult↗