Agrobacterium-mediated transformation of soft fruit Rubus, Ribes, and Fragaria.
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Agriculture↗
Biomedical subjects
J Graham
Publications and source records attributed to J Graham.
Referral for coronary angiography after exercise testing: traditional decision-making versus decision analysis.
To audit the referral decisions made by a single cardiologist for coronary angiography after exercise testing, we retrospectively reviewed the charts of 303 consecutive patients in a community hospital. The outcomes of these decisions, in terms of angiograms performed and quality-adjusted life expectancy gains as predicted by a decision analysis model, were compared with the theoretical decisions that would have been made using the model. The 97 patients sent for angiography exercised for a shorter time (5.6 +/- 3.1 vs. 6.9 +/- 3.2 min, p < 0.001) had more ST deviation (2.7 +/- 1.4 vs. 1.7 +/- 1.0 mm, p < 0.001), more angina (53.6 vs. 36.9% of patients, p < 0.01) and were more likely to have had a previous myocardial infarction (59.8 vs. 33.5% of patients, p < 0.001) than the 206 not referred. However, of those not referred, 137 were each predicted to gain up to 5.7 quality-adjusted life years (QALYs) from bypass surgery. The overall predicted gain from the cardiologist's decisions was only 0.1 +/- 2.5 QALYs/patient. Had the decisions been made using the model, the mean gain would have been 1.9 +/- 1.3 QALYs/patient, and an extra 128 patients would have been sent for angiography. Decision analysis makes consistent decisions with defined risks and benefits. Such decisions can be reproduced, reviewed and analysed, whereas traditional decision-making may inconsistently reflect the clinician's beliefs and values.
Aged↗
Long-term central venous access through the inferior epigastric vein.
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Catheterization, Central Venous↗
Iodixanol: a nonionic iso-osmotic centrifugation medium for the formation of self-generated gradients.
The physical and biological properties of Iodixanol, a new nonionic density gradient medium, are described in this paper. It is effectively a dimer of Nycodenz and it exhibits two significant advantages over previous iodinated density gradient media--its aqueous solutions are iso-osmotic up to a density of 1.32 g/ml and it is capable of forming self-generating gradients in 1 to 3 h. It has a very low toxicity toward biological material and enzyme assays can be carried out in its presence.
Cell Line↗
The preparation of subcellular organelles from mouse liver in self-generated gradients of iodixanol.
This paper reports the use of a new density gradient compound, Iodixanol, for the resolution of the major organelles from mouse liver. A major advantage of Iodixanol over other iodinated density gradient media is its ready ability to form self-generated gradients. Gradient-forming conditions have been modulated to provide optimal recoveries of Golgi membranes, lysosomes, mitochondria, and peroxisomes. The organelles were isolated in high yield (80-90% of gradient input) and high purity. Nycodenz and Iodixanol were compared using preformed gradients. Iodixanol provided resolution superior to that of Nycodenz, notably of peroxisomes and mitochondria and the separation of lysosomes from endoplasmic reticulum. Because Iodixanol does not interfere significantly with marker enzyme activities, gradient fractions can be analyzed without removal of the gradient medium.
Animals↗
Unilateral destruction of dopamine pathways increases ipsilateral striatal serotonin turnover in rats.
In order to evaluate the influence of dopaminergic transmission on regional brain utilization of serotonin (5HT), the effects of the destruction of the ascending dopamine (DA) pathways on regional brain 5HT metabolism in the rat were examined. Complete unilateral lesions of the nigrostriatal DA pathways (> 90% DA loss) were made by infusing the neurotoxin 6-hydroxy-dopamine into either the left medial forebrain bundle (MFB) or the left substantia nigra (SN). At 6 weeks after the lesions, levels of 5HT and its major metabolite, 5-hydroxyindoleacetic acid (5HIAA), were determined bilaterally in the striatum, frontal cortex, and hypothalamus. In the striatum of the lesioned hemisphere, the 5HT level decreased by more than 50%, while the ratio of 5HIAA:5HT (an index of 5HT turnover) increased by more than 90%. In the same rats, cortical and hypothalamic 5HT, 5HIAA, and 5HT turnover were not changed as a result of the MFB or SN lesions. These results suggest that the loss of DA innervation in the striatum triggers an increase in 5HT turnover and a net depletion of 5HT in the striatum. To verify that the loss of DA was responsible for the observed striatal 5HT changes, we examined the effect of intracerebral implantation of DA-containing pellets into one group of MFB-lesioned rats. The lesioned rats with placebo pellets did not differ from lesioned rats without pellets, whereas the implantation of DA pellets reversed the lesion-induced changes in the 5HT levels and 5HIAA:5HT ratios.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
In vivo and in vitro effects of gamma-linolenic acid and eicosapentaenoic acid on prostaglandin production and arachidonic acid uptake by human endometrium.
This study examines the effect of a 6 month dietary supplement of either gamma-linolenic acid (GLA) or eicosapentaenoic acid (EPA) on the synthesis of prostaglandins E2 and F2 alpha by the endometrium of women with regular menstrual cycles. Samples of endometrium, obtained pre- and post-treatment, were incubated in vitro for 2 h and the prostaglandins E2 and F2 alpha released into the medium measured by radioimmunoassay. The ability of the tissue to take up 14C-arachidonic acid before and after treatment was also examined. Both GLA and EPA caused a marked decrease in the synthesis of prostaglandins E2 and F2 alpha (P < 0.001) but under the experimental conditions used, there was no consistent effect on arachidonic acid uptake. Body mass index, serum testosterone, fasting insulin and serum sex hormone-binding globulin (SHBG) concentrations did not change during the 6 month treatment period. An effect of GLA and EPA on arachidonic acid uptake into endometrial tissue explants was demonstrated in vitro. In the presence of both GLA and EPA, uptake into phospholipids (particularly phosphatidylcholine) decreased while uptake into triglycerides increased. Free 14C-arachidonic acid levels (that which could not be removed from the tissue by washing) also increased. Suppression of endometrial prostaglandin E2 and F2 alpha synthesis following GLA or EPA supplementation can be explained as direct competition between these fatty acids and arachidonic acid (the precursor of 2-series prostaglandins) for incorporation into membrane phospholipids. The amount of arachidonic acid available for 2-series prostaglandin synthesis will therefore be reduced. However, other mechanisms may exist which need to be investigated.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
The growth of management connoisseurship through reflective practice.
Reflective practice offers a way to structure learning within supervision by paying attention to aspects of practice within reflected experiences, in such ways that the issues can be identified, understood, and worked through to resolve contradictions between desired outcomes and actual practice. In this process, emerging personal knowledge of practice is juxtaposed with relevant theory in such a way that the manager is able to meaningfully assimilate theory into his or her practice as appropriate. This paper illustrates how an H-grade unit nurse manager identified a number of situational management issues through reflecting and sharing experiences in a group clinical supervision milieu (over a period of 15 weeks). Clinical supervision is being advocated as a means to ensure practitioner development of effective practice (Vision for the Future, Department of Health 1993).
Education, Nursing, Continuing↗
STUDIES OF TROPICAL TUNA SWIMMING PERFORMANCE IN A LARGE WATER TUNNEL - ENERGETICS
The metabolic rates (V(dot)O2) of three tropical tunas [yellowfin tuna (Thunnus albacares), kawakawa (Euthynnus affinis) and skipjack (Katsuwonus pelamis)] were estimated using a large water-tunnel respirometer. Experiments lasting up to 31 h were used to determine the effects of velocity (U) on tuna V(dot)O2 over a range of U (17-150 cm s-1) and temperatures (18­30°C). Replicate tests were carried out on several fish. The swimming V(dot)O2 of yellowfin is temperature-dependent (Q10=1.67, determined over intervals of 3­5°C). For yellowfin and skipjack, it was also possible to partition metabolic costs between maintenance and locomotion. The standard metabolic rate (SV(dot)O2) was estimated by extrapolation of the U/V(dot)O2 function to U=0. Comparisons of SV(dot)O2 for different size groups of yellowfin show that the mass-specific scaling exponent for V(dot)O2 is -0.40. The SV(dot)O2 of tuna is comparable to values determined previously by stasis respirometry and is approximately three times higher than that of salmonids. Further comparisons with salmonids show that the slope of the U/V(dot)O2 function is less for tunas, which demonstrate a greater swimming efficiency.
Journal Article↗
STUDIES OF TROPICAL TUNA SWIMMING PERFORMANCE IN A LARGE WATER TUNNEL - THERMOREGULATION
The body temperatures (Tb) of nine yellowfin tuna (Thunnus albacares) were monitored while fish swam in a large water tunnel at controlled velocities (U) and ambient temperatures (Ta). Monitoring Tb during step changes in Ta at constant U permitted estimation of the thermal rate coefficient (k), an index of heat transfer. In the yellowfin, k is dependent on both Ta and the direction of the thermal gradient (i.e. whether Ta is greater or less than Tb). Modulation of k in response to Ta was further demonstrated during tests in which U was varied; the elevation of Tb in response to equal increases in U was 3­4 times less at 30 C than at 25 and 20 C. These experiments demonstrate that the yellowfin tuna can modulate heat transfer. This ability could prevent overheating during intense activity, retard heat loss during a descent into cool water and permit increased heat gain upon returning to warm surface waters (i.e. when Tb<Ta).
Journal Article↗
STUDIES OF TROPICAL TUNA SWIMMING PERFORMANCE IN A LARGE WATER TUNNEL - KINEMATICS
Yellowfin tuna (Thunnus albacares) swimming kinematics was studied in a large water tunnel at controlled swimming velocities (U). Quantified kinematic variables included the tail-beat frequency, stride length (l), caudal amplitude, yaw, the propulsive wavelength, the speed of the propulsive wave (C) and the sweepback angle of the pectoral fins. In general, all variables, except the propulsive wavelength and consequently C, are comparable to values determined for other teleosts. The propulsive wavelength for the tunas (1.23­1.29 L, where L is fork length) is 30­60 % longer than in other cruise-adapted teleosts such as salmonids. The resulting thunniform swimming mode and the morphological and anatomical adaptations associated with the long propulsive wavelength (e.g. fusiform body shape, rigid vertebral column) act to minimize anterior resistance and maximize caudal thrust. The long propulsive wavelength also increases the maximum l which, in concert with the elevated muscle temperatures of tunas, increases their maximum swimming velocity.
Journal Article↗
Automatic karyotype analysis.
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Centromere↗
Endogenous nitric oxide modulates vasopressor responses, but not depressor responses, to spinal sympathetic nerve stimulation in pithed rats.
The effects of N omega-nitro-L-arginine methylester (L-NAME), an inhibitor of nitric oxide (NO) synthase (1,5, and 10 mg/kg) on vasopressor and depressor responses to segmental sympathetic nerve stimulation were studied in the pithed rat preparation. Vasopressor responses were evoked by stimulation of the spinal sympathetic outflow at T6-T8 (30 V, 0.05 ms at 5 Hz with 10 pulses). This pressor response was biphasic: An initial transient response (to nerve stimulation) was followed by a later prolonged response (to adrenal catecholamine release). L-NAME 1, 5, and 10 mg/kg increased mean arterial blood pressure (MAP); this effect was maximal at 1 mg/kg L-NAME, but had no effect on heart rate (HR). L-NAME 1, 5, and 10 mg/kg potentiated both phases of the pressor response; the effect was maximal at 10 mg/kg. Vasodepressor responses were evoked by stimulation of the spinal sympathetic outflow at S2-L6 (30 V, 0.05 ms at 5 Hz with 10 pulses). L-NAME 1, 5, and 10 mg/kg did not inhibit these depressor responses. We conclude that inhibition of the synthesis of endogenous NO causes a hypertension in pithed rats that is associated with increased vasoconstriction in response to sympathetic nerve stimulation and adrenal catecholamine release. Systemic vascular depressor responses to segmental sympathetic nerve stimulation are not affected, however; therefore, NO cannot be the major mediator of these responses.
Animals↗
Salvage whole abdomen radiation therapy: its role in ovarian cancer.
PURPOSE: In spite of high initial response rates, many patients with epithelial ovarian carcinoma eventually fail their primary treatment. Further treatment with second-line regimens has been ineffective in producing durable responses. Thus, whole abdomen radiation therapy was evaluated as a salvage therapeutic modality as to its feasibility, efficacy, and toxicity. METHODS AND MATERIALS: Between June 1983 and June 1990, 44 patients who failed one or more chemotherapeutic regimens were treated with whole abdomen radiation therapy. Forty patients had epithelial carcinoma of the ovary and the remaining had primary adenocarcinoma of the peritoneal cavity. Radiation was delivered with an open-field technique and 2500 cGy were planned to the whole abdomen, with a boost when indicated. Prior to radiation, the amount of residual disease after debulking was noted to be microscopic in one-half of the patients and macroscopic in the other half. Pelvis alone was the site of residual disease in 14 patients, and upper abdominal involvement was found in 30. RESULTS: Five patients (11%) were unable to complete the planned therapy secondary to acute toxicity. The 4-year actuarial survival and recurrence-free survival rates for the entire group were 23% and 22%, respectively. The survival and recurrence-free survival rates for the group with microscopic residual disease at 37% and 42% were significantly better than those for the patients with macroscopic residual disease at 9% and 5% (p < 0.005; p < 0.001) at 4 years, respectively. Patients with disease limited to pelvis only had a recurrence-free survival of 56% compared to 0% when the upper abdomen was involved (p < 0.005). The abdomino-pelvic cavity was the first site of recurrence in 28 of 31 patients in whom the site of recurrence could be determined. Eight patients (18%) experienced bowel complications, of whom five needed surgical intervention. CONCLUSIONS: Whole abdomen radiation therapy with a pelvic boost is feasible with acceptable acute and late toxicity. It is effective in patients with minimal residual disease.
Abdomen↗
Application of artificial neural networks to chromosome classification.
This work presents an approach to the automatic classification of metaphase chromosomes using a multilayer perceptron neural network. Representation of the banding patterns by intuitively defined features is avoided. The inputs to the network are the chromosome size and centromeric index and a coarsely quantized representation of the chromosome banding profile. We demonstrate that following a fairly mechanical training procedure, the classification performance of the network compares favourably with a well-developed parametric classifier. The sensitivity of the network performance to variation in network parameters is investigated, and we show that a gain in efficiency is obtainable by an appropriate decomposition of the network. We discuss the flexibility of the classifier developed, its potential for enhancement, and how it may be adapted to suit the needs of current trends in karyotyping.
Algorithms↗
Efficacy and toxicity of fractionated stereotactic radiotherapy in the treatment of recurrent gliomas (phase I/II study).
Twenty-two patients with recurrent glioma have been treated on a dose escalation protocol with fractionated stereotactic external beam radiotherapy (SRT). All had previously received radical radiotherapy (median dose 55 Gy) as part of the initial treatment. The dose of SRT was increased from 30 Gy in six fractions to 50 Gy in ten fractions. Median survival from the date of SRT was 9.8 months. There was no significant acute morbidity but five patients who received > or = 40 Gy developed steroid responsive neurological deterioration assumed to represent late radiation damage. The survival and toxicity in patients with recurrent glioma are comparable with interstitial therapy. Fractionated SRT is a noninvasive form of localised radiation which may be a suitable alternative to interstitial therapy in this group of patients.
Adolescent↗
Effects of genotype and cryopreservation of avian semen on fertility and number of perivitelline spermatozoa.
1. The fertility of freshly diluted and cryopreserved samples of semen obtained from a population of chickens selected for duration of fertility of cryopreserved spermatozoa (FS line) and its unselected control (FC line) were compared over a range of spermatozoa concentrations (10, 40, 80, and 160 x 10(6) sperm/50 microliters insemination). 2. The spermatozoa of the FS line had greater fertility than spermatozoa of the FC line, whether freshly diluted or cryopreserved. Cryopreservation resulted in a reduction in fertility, regardless of line. There were no significant line by genotype interactions. 3. There were fewer spermatozoa from the FC line than the FS line found in the perivitelline membrane (perivitelline spermatozoa). The increase in number of perivitelline spermatozoa with increasing sperm concentration was greater in the FS than FC line. However, the slope of the increase in sperm number in the perivitelline membrane with increasing concentrations of cryopreserved spermatozoa was zero. 4. A minimum of 10(3) perivitelline spermatozoa must be found on day 2 post-insemination for duration of fertility to exceed three days. The ability to produce spermatozoa capable of reaching the forming perivitelline membrane appears to be a quantitative, rather than a qualitative, trait and may be subject to genetic manipulation.
Animals↗
A neural network approach to automatic chromosome classification.
Classification of banded metaphase chromosomes is an important step in automated clinical chromosome analysis. We have conducted a preliminary investigation of the application of artificial neural networks to this process, making use of a natural representation of the banding pattern. Two different network architectures have been compared: the Kohonen self-organizing feature map and the multi-layer perception (MLP). For each of these a search of their respective parameter spaces over a limited range has resulted in configurations of modest dimension which achieve creditable classification rates. The MLP in particular shows promise of being a useful classifier. When size and shape features are supplied as inputs to the MLP in addition to a low-resolution banding profile, misclassification rates are obtained which are comparable with those of a well developed statistical classifier.
Chromosomes↗