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Biomedical subjects

D M Hunter

Publications and source records attributed to D M Hunter.

At least 19 recordsLinked to original sources
PubMed2001

The use of 16S and 16S-23S rDNA to easily detect and differentiate common Gram-negative orchard epiphytes.

The identification of Gram-negative pathogenic and non-pathogenic bacteria commonly isolated from an orchard phylloplane may result in a time consuming and tedious process for the plant pathologist. The paper provides a simple "one-step" protocol that uses the polymerase chain reaction (PCR) to amplify intergenic spacer regions between 16S and 23S genes and a portion of 16S gene in the prokaryotic rRNA genetic loci. Amplified 16S rDNA, and restriction fragment length polymorphisms (RFLP) following EcoRI digestion produced band patterns that readily distinguished between the plant pathogen Erwinia amylovora (causal agent of fire blight in pear and apple) and the orchard epiphyte Pantoea agglomerans (formerly E. herbicola). The amplified DNA patterns of 16S-23S spacer regions may be used to differentiate E. amylovora at the intraspecies level. Isolates of E. amylovora obtained from raspberries exhibited two major fragments while those obtained from apples showed three distinct amplified DNA bands. In addition, the size of the 16S-23S spacer region differs between Pseudomonas syringae and Pseudomonas fluorescens. The RFLP pattern generated by HaeIII digestion may be used to provide a rapid and accurate identification of these two common orchard epiphytes.

DNA, Bacterial↗
PubMed2001

Effect of pH on the self-exchange reactivity of the plant plastocyanin from parsley.

The self-exchange rate constant (25 degrees C) for parsley plastocyanin is 5.0 x 10(4) M-1 s-1 at pH* 7.5 (I = 0.10 M). This value is quite large for a higher plant plastocyanin and can be attributed to a diminished upper acidic patch in this protein. The self-exchange rate constant is almost independent of pH* in the range 7.5-5.6, with a value (25 degrees C) of 5.6 x 10(4) M-1 s-1 at pH* 5.6 (I = 0.10 M). At this pH*, the ligand His87 is protonated in approximately 50% of the reduced protein molecules (pKa* 5.6), and this would be expected to hinder electron transfer between the two oxidation states. However, this effect is counterbalanced by the enhanced association of two parsley plastocyanins at lower pH* due to the partial protonation of the acidic patch.

Apiaceae↗
PubMed2001

Aerial treatment of the Australian plague locust, Chortoicetes terminifera (Orthoptera: Acrididae) with Metarhizium anisopliae (Deuteromycotina: Hyphomycetes).

Between October 1999 and April 2000, nearly 4000 ha of nymphal bands and adult swarms of Chortoicetes terminifera (Walker) were aerially treated using a ULV oil formulation of strain FI-985 of Metarhizium anisopliae var. acridum. During the mild weather (maxima 22-30 degrees C) of spring (October), there was little change in nymphal bands during the first week but at all doses between 25-100 g (1-4 x 10(12) conidia) ha(-1), the bands rapidly declined 9-12 days after treatment reaching > 90% mortality by 14 days. Metarhizium persisted for some time as there was 50% mortality of locusts fed vegetation collected from the treated blocks seven days after treatment. Persistence was confirmed by the high mortality of bands that invaded from untreated areas and of nymphs that hatched on the plot five to seven days after treatment, though mortality was then delayed until early in the third week. During summer (January), temperatures were high (maxima 36-42 degrees C), and at all doses between 25 and 125 g (1-5 x 10(12) conidia) ha(-1), there was a rapid decline seven to ten days after treatment. By 12-14 days, there was a > 90% decline in numbers in most blocks which was confirmed by helicopter surveys two weeks after treatment that found very few adults within or near treated areas. Mortality was delayed in the high dose where there were blockages of spray equipment during treatment. The clear demonstration that Metarhizium can suppress small local populations of C. terminifera led to the limited operational use of Metarhizium on an organic farm and in a National Park where nearly 2500 ha of bands and swarms were treated. Continued research is needed to develop a commercially viable product so that Metarhizium can form a significant part of a programme of integrated pest management of locusts in Australia.

Animals↗
PubMed2000

Hip arthroscopy in staging avascular necrosis of the femoral head.

The purposes of this study were to evaluate how accurately current imaging modalities predict the quality of the articular surface in avascular necrosis (AVN) of the femoral head and to provide arthroscopic correlation to current staging modalities. An arthroscopic classification system, derived from the work of Marcus et al, was used to prospectively stage the articular surface in 23 hips with AVN using plain radiographs, magnetic resonance imaging (MRI), and arthroscopy. There was little correlation between all three diagnostic modalities. These findings were not statistically significant. Patients with stage IV disease had the widest variation in the appearance of the articular surface. This study shows poor correlation in the staging of AVN using current imaging techniques. Magnetic resonance imaging has been shown to be inadequate at assessing the articular cartilage. Therefore, either arthroscopy or direct visualization is required for accurate evaluation and staging, especially in stage IV disease.

Arthroscopy↗
PubMed1999

Etiologic factors associated with Achilles tendinitis in runners.

PURPOSE: The purpose of this study was to determine whether relationships exist between selected training, anthropometric, isokinetic muscular strength, and endurance, ground reaction force, and rearfoot movement variables in runners afflicted with Achilles tendinitis. METHODS: Specifically, we examined differences in selected measures between a noninjured cohort of runners (N = 58) and a cohort of injured runners with Achilles tendinitis (N = 31). Isokinetic, kinetic, and kinematic measures were collected using a Cybex II+ isokinetic dynamometer (Medway, MA), AMTI force plate (500 Hz), and Motion Analysis high-speed videography (200 Hz), respectively. Separate discriminant function analyses were performed on each of the five sets of variables to identify the factors that best discriminate between the injured and control groups. RESULTS: Years running, training pace, stretching habits (injured runners were less likely to incorporate stretching into their training routine), touchdown angle, plantar flexion peak torque at 180 degrees x s(-1) and arch index were found to be significant discriminators. CONCLUSION: A combined discriminant analysis using the above mentioned significant variables revealed that plantar flexion peak torque, touchdown angle, and years running were the strongest discriminators between runners afflicted with Achilles tendinitis and runners who had no history of overuse injury.

Achilles Tendon↗
PubMed1996

Hip arthroscopy.

Explore the source record for details and available documents.

Adolescent↗
PubMed1995

Parents' knowledge of the purposes and content of preparticipation physical examinations.

OBJECTIVES: To determine whether parents of student athletes plan to use the preparticipation physical examination (PPE) as their student athlete's only annual health evaluation, to identify factors associated with this decision, and to assess their knowledge about the objectives of PPEs and more comprehensive examinations. DESIGN: Survey. SETTING: General community, school-sponsored PPEs. PARTICIPANTS: A convenience sample of parents or guardians of high school student athletes who obtained a school-sponsored, multiple-station format PPE were surveyed by using an anonymous paper-and-pencil questionnaire. Questionnaires were completed by the parents of 381 of 763 student athletes who obtained PPEs (participation rate, 49.9%). RESULTS: Thirty percent of the parents in this sample planned to use the PPE as their student athlete's only contact with a health care provider. Parents whose adolescent's health insurance provided for comprehensive health assessments were more likely than those without this benefit to plan a comprehensive care evaluation (75% vs 60%, respectively) (P = .01 by chi 2 analysis). In addition to addressing problems that might affect sports participation, parents thought that the PPE visit should evaluate medical problems that are unrelated to athletics (34%), perform health screening procedures (22%), assess social or behavioral issues (16%), and provide immunizations (7%). CONCLUSIONS: Many parents plan to use the PPE as their student athlete's only scheduled contact with a health care provider; this decision may be influenced by factors that are related to access to health care and misperceptions with regard to the mission of these specialized examinations. For these adolescents, important medical, social, and behavioral needs may not be met. Consideration should be given to including elements of the PPE in health assessments that are performed by individual clinicians or expanding the scope of large-group, multiple-station format PPEs.

Adolescent↗
PubMed1995

X-ray imaging using amorphous selenium: photoinduced discharge (PID) readout for digital general radiography.

Digital radiographic systems based on photoconductive layers with the latent charge image readout by photoinduced discharge (PID) are investigated theoretically. Previously, a number of different systems have been proposed using sandwiched photoconductor and insulator layers and readout using a scanning laser beam. These systems are shown to have the general property of being very closely coupled (i.e., optimization of one imaging characteristic usually impacts negatively on others). The presence of a condensed state insulator between the photoconductor surface and the readout electrode does, however, confer a great advantage over systems using air gaps with their relatively low breakdown field. The greater breakdown field of condensed state dielectrics permits the modification of the electric field during the period between image formation and image readout. The trade-off between readout speed and noise makes this system suitable for instant general radiography and even rapid sequence radiography, however, the system is unsuitable for the low exposure rates used in fluoroscopy.

Biophysical Phenomena↗
PubMed1995

Etiology of iliotibial band friction syndrome in distance runners.

The objectives of our study were: 1) to examine differences between a noninjured cohort of runners (N = 70) and runners afflicted with iliotibial band friction syndrome (ITBFS) (N = 56) according to selected anthropometric, biomechanical, muscular strength, and training measures; 2) to explore multivariate relationships among these measures in both the well and injured groups; and 3) to develop specific hypotheses concerning risk factors for injury that will later be tested in a prospective observational study. High speed videography (200 fps), a force platform (500 Hz), and a Cybex II+ isokinetic dynamometer were used to assess rearfoot motion, ground reaction forces, and knee muscular strength and endurance, respectively. A linear discriminant function analysis of the training data revealed weekly mileage, training pace, number of months using current training protocol, % time spent swimming, and % time spent running on a track to be significant (P < 0.10). Height was a significant anthropometric discriminator, while seven isokinetic strength and endurance measures were found to discriminate significantly between the groups. Calcaneal to vertical touchdown angle, and maximum supination velocity were significant rearfoot movement discriminators. Maximum braking force was the only significant kinetic discriminator. A combined discriminant analysis using those variables found to be significant in the previous analyses revealed weekly mileage, and maximum normalized braking force to be the best discriminators (model P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effects of isopropyl alcohol, ethanol, and polyethylene glycol/industrial methylated spirits in the treatment of acute phenol burns.

STUDY OBJECTIVE: To compare the effects of water rinse with those of isopropyl alcohol, polyethylene glycol with industrial methylated spirits, or ethanol on cutaneous phenol burns. DESIGN: Controlled trial with all animals receiving all treatments applied to different cutaneous phenol burn sites. TYPE OF PARTICIPANTS: Swine weighing 9 to 18 kg. INTERVENTIONS: In phase 1, each burn site was treated with water rinse for zero, one, or five minutes combined with either isopropyl alcohol, polyethylene glycol with industrial methylated spirits, ethanol, or no other treatment. Biopsies of treatment sites were done at 30 minutes and at 48 hours. In phase 2, a pilot study, the effect of isopropyl alcohol, polyethylene glycol with industrial methylated spirits, or water treatment on serum phenol levels was noted in animals with 5%, 10%, and 15% body surface area burns. MEASUREMENTS AND MAIN RESULTS: In phase 1, on histological examination of biopsy specimens, significant differences in tissue damage occurred among the groups (P < .05). Isopropyl alcohol and polyethylene glycol with industrial methylated spirits were the most efficacious treatments; the duration of water rinse had no significant effect. In phase 2, the systemic absorption of phenol may be greater with water treatment than with isopropyl alcohol treatment. CONCLUSION: Isopropyl alcohol and polyethylene glycol with industrial methylated spirits are equally effective in the amelioration of phenol burns of less than 5% total surface area. The wider availability of isopropyl alcohol makes it potentially the most useful treatment for these small burns. Further studies of its risks are needed.

1-Propanol↗
PubMed1990

Production and use of murine monoclonal antibodies reactive with bovine IgM isotype and IgG subisotypes (IgG1, IgG2a and IgG2b) in assessing immunoglobulin levels in serum of cattle.

Utilizing in-vitro and in-vivo immunizations, murine monoclonal antibodies (Mab's) that are specific for bovine immunoglobulin (IG)--IgM isotype and IgG subisotypes (IgG1, IgG2a and IgG2b)--have been produced. These Mab's were used to estimate the quantities of these bovine Ig isotype and IgG subisotypes in the sera of 56 cows and 24 bulls. The cows were all approximately 18 months of age and the bulls ranged from 12 to 18 months in age. The cows and bull were all apparently healthy and unimmunized. The cows were not pregnant and were nulliparous. Some differences were observed between the serum levels of IgM (higher in cows) and IgG1 (higher in bulls). No ready explanation can be offered for these observed differences.

Animals↗
PubMed1989

Optic nerve pseudomeningioma secondary to localized amyloidosis.

A 55-year-old woman presented with a mass of the optic nerve sheath suggestive of a meningioma. On excision, this proved to be amyloid. No systemic involvement could be found. Although amyloid may arise as a solitary lesion of the orbit or extraocular muscle, this "pseudomeningiomatous" pattern has not been previously noted. A magnetic resonance scan was helpful because the amyloid imaged at a density similar to vitreous and cerebral white matter, unlike meningiomas, which appear more like bone. The diagnosis of localized amyloidosis, however, still remains dependent on histopathology and cannot be made on a clinical basis.

Amyloidosis↗
PubMed1988

Study of prostaglandins and intraocular pressure in rabbits after Nd:YAG laser anterior segment procedures.

Radioimmunoassay of rabbit aqueous humor one hour after Nd:YAG laser anterior capsulotomies revealed increased concentrations of 6-keto-prostaglandin F1 alpha (PGF1 alpha), and thromboxane B2 (TBB2). Coincidental rises in intraocular pressure (IOP) and aqueous humor protein were observed. These changes correlated with the laser power used. Pretreatment with topical 1% prednisolone acetate or 1% indomethacin prior to anterior capsulotomies inhibited the post laser rise in PGF1 alpha and TBB2, but did not eliminate the post laser rise in IOP. Small rises in IOP and the concentrations of aqueous PGF1 alpha, TBB2, and protein were observed after Nd:YAG laser iridectomies. These changes were not affected by prior treatment with 1% topical prednisolone acetate. Although PGF1 alpha and TBB2 are elevated after Nd:YAG laser anterior segment procedures, a causal relationship between post treatment IOP rise and PGF1 alpha or TBB2 release could not be determined.

Animals↗
PubMed1983

Derivation of monoclonal antibodies against Brucella abortus antigens.

In vivo immunization, fusion, antibody detection, and cryopreservation procedures for monoclonal antibody production against antigens of Brucella abortus are described. Splenocytes from BALB/c mice immunized with irradiated B. abortus S2308 were fused with Sp2/O-Ag14 myeloma cells and 61 hybridomas secreting anti-Brucella antibodies were cloned. Hybridoma antibody synthesis was detected effectively and most efficiently by enzyme-linked immunosorbent assays. Antibodies from clones of hybridoma A23 reacted with S19 and S2308 whole bacterial cells, while hybridoma B49 reacted primarily with alkali--treated lipopolysaccharides of S19, S1119.3 and S2308. Cryopreservation of clones had no major effect on antibody synthesis. The application of monoclonal anti-Brucella antibodies in the differential diagnosis of bovine brucellosis is discussed.

Animals↗
PubMed1982

Relation between tracheal size and forced expiratory volume in one second in young men.

Maximal expiratory flow-volume curves and spirometry were measured in 49 white, nonsmoking, asymptomatic men 19 to 23 yr of age and 179 to 184 cm tall. Because of the uniformity of sex, age, height, and ethnic group, conventional predicted values for these men were virtually identical. Nevertheless, the between-subject coefficient of variation in spirometric and maximal flow results varied from 10% for vital capacity (VC) and forced expiratory volume in one second (FEV1) to 29% for maximal flow when 25% of VC remained to be expired. Confirming previous results, between-subject coefficient of variation was not reduced by expressing flow as VC/s instead of L/s. Eighteen of these men had standard posteroanterior and lateral chest radiographs to measure tracheal diameters at total lung capacity. Both tracheal cross-sectional area and anteroposterior diameter were positively related to FEV1 (r = 0.73, p = 0.001), the relationship being slightly stronger than with peak expiratory flow. There was a trend for VC also to be related to tracheal dimensions. As 50% of residual between-subject variation in FEV1 in these men was accounted for by variation in tracheal size, predicted values of FEV1 in an individual subject might be usefully refined by measuring tracheal size in epidemiologic surveys, thus allowing interpretation of small deviations from mean predicted values. Further studies are required on the variation in tracheal size in a more heterogeneous population.

Adult↗