Biomedical subjects

H Brace

Publications and source records attributed to H Brace.

3 recordsLinked to original sources

PubMed2006

A prospective, randomized trial comparing conventional transurethral prostate resection with PlasmaKinetic vaporization of the prostate: physiological changes, early complications and long-term followup.

PURPOSE: We compared standard transurethral prostate resection with bipolar PlasmaKinetic prostate vaporization for bladder outflow obstruction using a Gyrus PlasmaKinetic Plasma V bar. MATERIALS AND METHODS: A total of 160 men were enrolled in a prospective, randomized trial. Those at higher risk for cancer were excluded by prostate specific antigen and digital rectal examination with or without transrectal ultrasound biopsy. A total of 81 men underwent prostate vaporization and 79 underwent transurethral prostate resection. Preoperative International Prostate Symptom Score and quality of life score, uroflowmetry, post-void residual urine and transrectal ultrasound prostate volume were recorded. Preoperative and postoperative serum hemoglobin, hematocrit and sodium were measured. Perioperative fluid absorption was calculated using weighing on table and blood loss using the Hemocue system. Longer followup of International Prostate Symptom Score and quality of life score, uroflowmetry and post-void residual urine was available in 149 men, including 76 who underwent prostate vaporization and 73 who underwent transurethral prostate resection. Data were analyzed using the 1 or 2-sample t and chi-square tests. RESULTS: The 2 groups were comparable in all preoperative parameters. Perioperative fluid absorption, intraoperative blood loss, preoperative and postoperative serum hematocrit, and sodium changes were not statistically different. Mean resection time was 4 minutes shorter for transurethral prostate resection (28.5 vs 32.6 minutes, p = 0.08). Patients with transurethral prostate resection showed a greater hemoglobin decrease (1.39 vs 0.8 gm/dl, p = 0.002) and required more irrigation postoperatively (28.3 vs 20.4 l, p = 0.001). Four patients with transurethral prostate resection required transfusion compared with none who underwent prostate vaporization. After transurethral prostate resection hospital stay was longer (3.36 vs 3.02 days, p = 0.03). Cancer was detected in 8 patients with transurethral prostate resection (10%), of whom 7 are under prostate specific antigen surveillance and 1 received radical radiotherapy. Mean long-term followup was 258 days (range 82 to 884). Prostate vaporization and transurethral prostate resection were equally effective at followup, as evidenced by changes in maximum urine flow, International Prostate Symptom Score, quality of life score and post-void residual urine. CONCLUSIONS: The 2 operations are highly effective in experienced hands. PlasmaKinetic prostate vaporization resulted in less postoperative bleeding and a slightly shorter hospital stay. The lack of a histological specimen with this version of PlasmaKinetic prostate vaporization may mean that clinically significant cancers are missed.

Adult↗

PubMed1997

Neurotoxicity, blood-brain barrier breakdown, demyelination and remyelination associated with NMDA-induced lesions of the rat lateral hypothalamus.

Excitotoxins have been widely used to make lesions in the brains of experimental animals because they have the ability to destroy neurones while sparing fibres of passage. Because loss of fibres of passage can confound the interpretation of lesion effects, this property is of considerable value. Recently, however, there have been reports indicating that excitotoxins acting at different sites within the rat CNS not only destroy neurones but also strip myelin from fibres and compromise the integrity of the blood-brain barrier. However, some reports also indicate that the myelin content of the lesioned area recovers. Excitotoxic lesions of the lateral hypothalamus have been shown to produce local demyelination. The present studies sought to investigate this effect further by (1) defining the time course of demyelination and possible remyelination after excitotoxic lesions of the lateral hypothalamus made with N-methyl-D-aspartate (NMDA); (2) establishing the relationships between neuronal loss, de- and remyelination after various doses of NMDA; and (3) examining the integrity of the blood-brain barrier using an immunohistochemical probe. Our data show that after injection of NMDA into the lateral hypothalamus there was neuronal loss, blood-brain barrier disruption (followed by recovery over approximately 12 days), triggering of reactive gliosis, invasion of the lesioned area by cells from outwith the CNS, demyelination over an area coexistent with but not exceeding the area of neuronal loss, and remyelination. Remyelination occurred over a period of 3 months following the production of the lesion and was associated initially with blood vessels. It occurred across the whole of the lesioned area, not by encroachment from the borders. All doses of NMDA that produced neuronal death also produced demyelination. These data confirm that excitotoxic lesions of the lateral hypothalamus demyelinate fibres, but show for the first time that remyelination occurs here. They are consistent with reports concerning excitotoxin actions at other CNS sites and indicate that de- and remyelination after excitotoxic lesions is a ubiquitous process. Consideration should be given to this when using excitotoxins to make fibre-sparing lesions.

Animals↗

PubMed1993

Neurotoxicity of peptide analogues of the transactivating protein tat from Maedi-Visna virus and human immunodeficiency virus.

Infection by lentiviruses such as human immunodeficiency virus, Maedi-Visna virus and Caprine Arthritis Encephalitis Virus, is associated with a variety of neurological syndromes, but the mechanism by which the damage occurs to the nervous system is not known. The viruses do not infect neurons and so the neurotoxic actions must be mediated indirectly. Here we applied synthetic peptide analogues derived from basic regions of Maedi-Visna virus and human immunodeficiency virus transactivating protein, tat, to rat brain in vivo and found them to be potent neurotoxins. The toxicity of the Maedi-Visna virus peptide was demonstrated to be reduced by blockade of nitric oxide synthase and of N-methyl-D-aspartate channel opening. These experiments suggest that peptides derived from lentiviral tat may share a common neurotoxic action.

Amino Acid Oxidoreductases↗