Cellular mechanisms of behavioral sensitization to drugs of abuse.
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Animals↗
Biomedical subjects
P Duffy
Publications and source records attributed to P Duffy.
Calf vein anatomy and flow: implications for colour Doppler imaging.
Early experience has suggested that colour flow Doppler ultrasound may have a diagnostic role in calf vein thrombosis. Before its accuracy within the calf can be adequately assessed, normal calf vein flow and anatomy needs to be understood. We, therefore, studied 40 normal volunteers, age range 24-75 years (mean 45.4), M:F 22:18, and assessed both flow and venous diameter in each of the three sets of calf veins in the supine and erect positions and once again in both these positions following the application of an above knee band. Paired sets of veins were present in all posterior tibial and common peroneal sets, but in only 85% of the anterior tibial group. Significant flow variations were present between different sets of veins, there being relatively less appreciable flow within the common peroneal (p < 0.05). Both band application and erect posture produced significant increases in venous diameter (p < 0.01, p < 0.001) in the posterior tibial and common peroneal veins, aiding visualization but at the cost of reducing flow following band application (p < 0.05, p < 0.01). The erect posture had no deleterious effect on calf vein flow. We, therefore, recommend that when the patency of calf veins is being assessed scanning should be performed in both a supine and erect position as this will help vein visualization without a reduction in flow, and thus avoid misinterpretation.
Adult↗
Colour flow imaging of calf vein thrombosis.
Ultrasound and more recently colour Doppler ultrasound has been successfully used in the diagnosis of lower limb venous occlusive disease. Colour Doppler ultrasound has shown promise in the diagnosis of calf vein thrombosis but to date there has been no prospective trial to specifically evaluate its potential. In view of this, we carried out a prospective trial of 50 patients comparing the accuracy of colour Doppler ultrasound with venography in the diagnosis of deep venous thrombosis both above and below knee but in particular with respect to the detection of calf vein clot. Of the 50 patients studied, 10 had only one imaging modality performed as there were eight venographic failures and two ultrasonic failures. Comparison was only thus possible in 40 cases. As in previous studies, colour Doppler ultrasound was shown to be accurate in the diagnosis of thrombosis within the femoro-popliteal veins and had a sensitivity and specificity of 100% respectively. With respect to calf vein lesions, there was one false negative scan using the ultrasonic technique giving a sensitivity of 95%, specificity of 100% and accuracy of 97.5%. We feel colour Doppler ultrasound can and should be used as a first line alternative to venography and can be employed for the exclusion of both above and below knee deep venous thrombosis. Venography should now be reserved for those patients who are unsuitable for ultrasound examination or who have an equivocal ultrasound scan.
Adult↗
Effects of 5-hydroxytryptophan on extracellular serotonin in the spinal cord of rats with experimental allergic encephalomyelitis.
Serotonin (5-HT) and the serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA) were collected by in vivo dialysis in the lumbar spinal cord of control rats and rats with hindlimb paralysis induced by experimental allergic encephalomyelitis (EAE). Both 5-HT and 5-HIAA were significantly decreased in baseline samples from EAE rats compared to controls. This decrease in extracellular 5-HT and 5-HIAA in the EAE rats was accompanied by marked morphological changes in spinal cord axons and axon terminal plexuses that were stained for 5-HT-like immunoreactivity. The 5-HT precursor, 5-hydroxytryptophan (5-HTP)-increased 5-HT and 5-HIAA levels in dialysate samples from both control and EAE animals. However, the 5-HTP-induced increase in extracellular 5-HT was significantly greater in the EAE rats than in the controls, despite a lower baseline 5-HT level in the EAE animals. In contrast to 5-HT, both baseline and post-5-HTP levels of 5-HIAA were significantly higher in control animals than in EAE animals. The decreased extracellular 5-HT and 5-HIAA in baseline samples from the EAE rats compared to controls is probably a consequence of the damage to descending 5-HT axons and axon terminals that occurs during the disease. The larger increase in extracellular 5-HT in EAE animals after precursor injection may reflect both decreased 5-HT reuptake from the extracellular space by damaged 5-HT terminals and disruption of the blood-brain barrier that allows entry into the central nervous system of 5-HT that was synthesized from 5-HTP in the periphery.
5-Hydroxytryptophan↗
Effect of acute and daily neurotensin and enkephalin treatments on extracellular dopamine in the nucleus accumbens.
The injection of neurotensin or the enkephalin analog Tyr-D-Ala-Gly-MePhe-Gly(ol) (DAMGO) into the A10 region of rats produces a motor stimulant effect that is associated with an increase in the postmortem levels of dopamine metabolites in the nucleus accumbens. These behavioral and neurochemical effects are augmented following daily administration. In vivo dialysis in the nucleus accumbens of conscious rats was used to determine if the acute and augmented behavioral responses following neurotensin or DAMGO administration are associated with an increase in extracellular dopamine concentrations. The acute injection of DAMGO produced a dose-dependent (0.03-3.3 nmol) elevation in extracellular dopamine and its metabolites in the nucleus accumbens. Neurotensin also produced a dose-related (0.1-3.3 nmol) increase in dopamine and its metabolites. The elevation in extracellular dopamine produced by DAMGO, but not by neurotensin, was positively correlated with the increase in motor activity. Following daily treatment of either neurotensin (1.0 nmol X 4 d) or DAMGO (0.03 nmol X 4 d), a significant elevation in extracellular dopamine levels occurred in the nucleus accumbens compared to an acute injection. The time course of the change in extracellular dopamine after daily injections was similar to the time course of the behavioral stimulation for both compounds. These data demonstrate that enhanced dopamine release in the nucleus accumbens mediates the acute behavioral effect of DAMGO but does not entirely explain the motor effects of neurotensin. However, enhanced dopamine release may mediate the behavioral sensitization produced by daily injection of both peptides into the A10 region.
3,4-Dihydroxyphenylacetic Acid↗
A surgical approach to diagnostic ultrasound and its relation to other organ imaging techniques.
Ultrasound can be of considerable help to the surgeon in the diagnosis of non-bowel abdominal lesions and of peripheral soft tissue masses. Its relationship to established radiological and nuclear medicine technqiues and computed tomography is discussed. The place of ultrasound in an organ imaging department is outlined.
Abdomen↗
Current status of echography (ultrasound).
Ultrasonic demonstration of the anatomy and pathology of solid and fluid-filled organs and structures of the upper abdomen, the retroperitoneum and the pelvis is now well established, as is its use for examination of the thyroid gland, breast, the orbit, the heart, the scrotum and soft tissue masses. Aspiration of cytological and histological material for tissue diagnosis and other purposes is performed in a number of centres. Echography and computed tomography of the abdomen are complementary and there is a trend towards combined units so that each service may be used more efficiently.
Abdomen↗
Ultrasound demonstration of a 1.5 cm intrarenal angiomyolipoma.
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Adult↗
Ultrasound and computed tomography in abdominal diagnosis.
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Abdomen↗
Adjuvant nitrosourea therapy for glioblastoma.
An attempt was made to evaluate the potential advantages of chemotherapy in the treatment of 62 patients with glioblastoma. Twenty-four of the 62 patients received adjuvant nitrosourea chemotherapy with carmustine (BCNU), lomustine (CCNU), or semustine (methyl CCCNU) in addition to surgery and radiotherapy. Thirty-three of the 62 patients were involved in a controlled, prospective, randomly allocated study. Quality or quantity of survival was not prolonged in patients who received chemotherapy. Age greater than 64 years, a severe postoperative neurological deficit, or the onset of symptoms less than 12 months prior to surgery were associated with a worse prognosis. The valid evaluation of the effect of a form of treatment on survival in patients with glioblastoma is contingent on the regorous avoidance of preselected factors that may predispose the treated group to a more favorable prognosis.
Adolescent↗
Polyamine metabolism, RNA synthesis, and proliferation in density-Inhibited 3T3 cells.
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Cell Aggregation↗
Establishment of a viable homograft cardiac valve bank: a rapid method of determining homograft viability.
A method for determining the viability of homograft valves has been developed based on sequential measurements of glucose and pH levels of the culture medium in which cardiac valves have been maintained for short periods at 37 degrees C. Viable valves, as determined by tissue culture, showed a characteristic pattern of glucose utilization and pH reduction that was absent in nonviable valves. Upon explantation of valve leaflet fragments into tissue culture, only fragments from valves that metabolized glucose produced viable fibroblast cultures. The method reported here is rapid, requires no specialized equipment, is nondestructive, and can directly determine the viability of the valve homograft within 24 to 48 hours.
Aortic Valve↗
Trauma - not fatal: another view on community nursing.
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Community Health Nursing↗
On the role of prostaglandins in parturition in the rat.
Treatment of both intact and hypophysectomized pregnant rats on days 19 and 20 of pregnancy with PGF2alpha results in a rapid fall in plasma progesterone concentrations by day 20 followed by premature delivery on day 21. Administration of depoprovera did not prevent the PGF2alpha-induced fall in progesterone levels but premature littering was adverted. Indomethacin, an inhibitor of prostaglandin biosynthesis, postponed the onset of parturition by 20 h when administered in late pregnancy but rats treated with both indomethacin and PGF2alpha delivered at the normal time. Treatment of both intact and hypophysectomized animals with indomethacin delayed the fall in plasma progesterone concentrations which normally occurs between days 21 and 22 of pregnancy. Concomitant PGF2alpha treatment of rats receiving indomethacin caused plasma progesterone levels to fall in a pattern similar to controls. These findings indicate that endogenous PGF2alpha induces a fall in blood progesterone concentrations which is followed by increased myometrial activity.
Animals↗