Immunophilins mediate the neuroprotective effects of FK506 in focal cerebral ischaemia

The immunosuppressive action of the drug FK506 involves inhibition of calcineurin in T-lymphocytes by a complex of FK506 and an FK506 binding protein, FKBP12, a member of the immunophilin protein family. The functional role of brain immunophilins is, however, unclear. We show here that FK506 is a powerful neuroprotective agent in an in vivo model of focal cerebral ischaemia when administered up to 60 min post-occlusion. The minimum effective neuroprotective dose is comparable with the immunosuppressant dose in humans, suggesting that FK506 may have clinical potential for the treatment of stroke. Although the related immunosuppressants rapamycin and cyclosporin failed to reduce brain damage, the finding that rapamycin pretreatment blocked the effect of FK506 confirms a role for immunophilins in the neuroprotective mechanism.

Perivascular microapplication of endothelin-1: a new model of focal cerebral ischaemia in the rat

In the present study, we describe the effects of perivascular microapplication of the potent vasoconstrictor peptide endothelin-1 (ET-1; (120 pmol in 3 microliters), delivered via a guide cannula stereotaxically positioned above the left cerebral artery (MCA) of the conscious male Sprague-Dawley rat. Ten minutes after the administration of Et-1, mean arterial blood pressure had increased by 20% and profound reductions in local cerebral blood flow (up to 93%) were observed within those brain areas supplied by the MCA. In addition, significant increases in local cerebral blood flow were observed within the globus pallidus (100%), substantia nigra pars reticulata (48%), ventrolateral thalamus (65%), and dorsal hippocampus (74%) ipsilateral to the insult. Twenty-four hours following the insult, the pattern of ischaemic damage was similar to that reported previously following permanent occlusion of the rat MCA. It is suggested that perivascular microapplication of Et-1 may provide a useful model for the study of the functional disturbances associated with focal cerebral ischaemia in the conscious rat.

Cocaine binding at sigma receptors

Cocaine and some related psychostimulants interact with sigma receptors in binding assays. Their Ki values are compatible with blood concentrations reported to produce psychosis in human volunteers. It is proposed that the psychotomimetic effects of some psychostimulants may derive, at least in part, from their interaction with sigma receptors.

Caspase 6 activity initiates caspase 3 activation in cerebellar granule cell apoptosis

Using a well documented ex vivo system consisting of rodent cerebellar granule cells (CGCs) the activation of caspases 3 and 6 during apoptosis induced by withdrawal of trophic support was analyzed. At the time of deprivation, the addition of the irreversible, broad-spectrum caspase inhibitor zVADfmk or the cell permeable, caspase 6 inhibitor CP-VEID-cho can transiently suppress the appearance of apoptosis, including the early appearance of DNA fragmentation. Using immunoblotting and fluorogenic peptide assays we observe deprivation-induced activation of caspases 3 and 6, but not caspase 9. Furthermore, active caspase 6 is capable of processing and activating procaspase 3 in cellular extracts prepared from non-apoptotic CGCs, whereas caspase 3 failed to activate caspase 6. In consonant with this, the cell permeable caspase 6 inhibitor prevented deprivation-induced caspase 3 activation whereas a cell permeable caspase 3 inhibitor, CP-DEVD-cho, had no effect on caspase 6 activation. This would indicate that caspase 6 is a significant inducer of the early caspase 3 activity in apoptotic CGCs.

[3H]dofetilide binding to HERG transfected membranes: a potential high throughput preclinical screen

The pharmacological characteristics of [3H]dofetilide binding were examined in membranes prepared from human embryonic kidney (HEK293) cells stably expressing human ether-á-go-go related gene (HERG) K+ channels. The classIII antiarrhythmic compounds dofetilide, clofilium, 4'-[[1-[2-(6-methyl-2-pyridyl)ethyl]-4-piperidyl]carbonyl]methanesulfonanilide (E-4031), N-methyl-N-[2-[methyl-(1-methyl-1H-benzimidazol-2-yl)amino]ethyl]-4-[(methylsulfonyl)amino]benzene-sulfonamide (WAY-123,398) and d-sotalol all inhibited [3H]dofetilide binding. In addition, the structurally unrelated compounds pimozide, terfenadine and haloperidol, all of which prolong the QT interval in man, also inhibited binding. These data indicate that a [3H]dofetilide binding assay using HERG membranes may help identify compounds that prolong the QT interval.

Beyond the Brain: Peripheral Interactions after Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of death and disability, and there are currently no pharmacological treatments known to improve patient outcomes. Unquestionably, contributing toward a lack of effective treatments is the highly complex and heterogenous nature of TBI. In this review, we highlight the recent surge of research that has demonstrated various central interactions with the periphery as a potential major contributor toward this heterogeneity and, in particular, the breadth of research from Australia. We describe the growing evidence of how extracranial factors, such as polytrauma and infection, can significantly alter TBI neuropathology. In addition, we highlight how dysregulation of the autonomic nervous system and the systemic inflammatory response induced by TBI can have profound pathophysiological effects on peripheral organs, such as the heart, lung, gastrointestinal tract, liver, kidney, spleen, and bone. Collectively, this review firmly establishes TBI as a systemic condition. Further, the central and peripheral interactions that can occur after TBI must be further explored and accounted for in the ongoing search for effective treatments.

Characterisation of an experimental model of stroke produced by intracerebral microinjection of endothelin-1 adjacent to the rat middle cerebral artery

A novel experimental model of stroke has been developed using the powerful vasoconstrictor peptide, endothelin-1, to occlude the middle cerebral artery (MCA) of anaesthetised rats. Intracerebral microinjections of endothelin-1 were administered under stereotaxic guidance adjacent to the MCA, and after 3 days rats were perfusion fixed for histopathological determination of ischaemic brain damage. The pattern of brain damage noted using this model was similar to that reported following permanent surgical occlusion of the MCA. Brain damage was apparent in the dorsal and lateral neocortex (98 +/- 12 mm3) and striatum (32 +/- 3 mm3) ipsilateral to the insult. Rats anaesthetised with halothane and barbiturate exhibited a similar volume of brain damage. However, infarct volume increased when the duration of halothane anaesthesia was extended from 5 to 180 min post-occlusion. Neuroprotection studies demonstrated that dizocilpine (5 mg/kg, i.p.), administered 30 min prior to MCA occlusion, reduced the volume of cortical brain damage by 51% (P < 0.05) but did not alter the volume of striatal brain damage. The present results demonstrate that microinjections of endothelin-1 adjacent to the rat MCA result in a reproducible pattern of focal cerebral infarction which is sensitive to the duration of anaesthesia and can be reduced by dizocilpine.

Neuroanatomic specificity and time course of alterations in rat brain serotonergic pathways induced by MDMA (3,4-methylenedioxymethamphetamine): assessment using quantitative autoradiography

The widely abused "designer" drug MDMA (3,4-methylenedioxymethamphetamine) has been shown to cause marked and long-lasting changes in brain serotonergic systems. The present study uses quantitative in vitro autoradiography of 3H-paroxetine labeled 5-HT uptake sites to assess the time-dependent effects of MDMA on 5-HT neurons in specific neuroanatomic loci. Following treatment with MDMA (20 mg/kg, b.i.d. for 4 days), marked decreases in 5-HT uptake sites were observed in a number of brain regions known to receive projections of 5-HT neurons. These regions included cerebral cortex, caudate nucleus, hippocampus, nucleus accumbens, olfactory tubercle, superior and inferior colliculi, geniculate nuclei, and most thalamic nuclei. In contrast, other areas such as the septal nuclei and some thalamic nuclei which also receive 5-HT projections were not substantially affected by this drug. In most regions, decreases in 5-HT uptake sites occurred within 24 hours of the last dose of MDMA and persisted at the 2 week time point. Some regions such as dorsal striatum exhibited a time-dependent reduction with greater reductions occurring at 2 weeks rather than immediately following the MDMA treatment regimen. The density of 5-HT uptake sites in other regions such as endopiriform nucleus and substantia nigra at the 2 week versus 18 hour time point indicated some degree of region-specific recovery. Regions which demonstrated no significant reduction in 5-HT uptake sites included the dorsal and median raphe nuclei, ventral tegmental area, central grey, interpeduncular nucleus, locus coerulus, pontine reticular formation and cerebellum. Likewise, regions containing 5-HT axons of passage (e.g., indusium griseum and lateral hypothalamus) appeared to be insensitive to the neurotoxic effects of MDMA on 5-HT neurons. Furthermore, the neurotoxic effects of MDMA showed specificity in that the catecholamine neurons labeled by 3H-mazindol were unaffected by the treatment regimen. These data indicate that the preferential degeneration of serotonergic neurons by MDMA is mediated primarily at 5-HT terminal regions, whereas regions containing 5-HT perikarya and axons of passage remain relatively unaffected. In addition, the observed time-dependent reductions and recovery of 5-HT uptake sites which were detected within 2 weeks of the treatment regimen in certain brain regions suggest region-specific differences in recovery of 5-HT systems from MDMA-induced lesion.

Nucleophosmin is a novel Bax chaperone that regulates apoptotic cell death

The proapoptotic B-cell lymphoma-2 family protein Bax is a key regulatory point in the intrinsic apoptotic pathway. However, the factors controlling the process of Bax activation and translocation to mitochondria have yet to be fully identified and characterized. We performed affinity chromatography using peptides corresponding to the mitochondrial-targeting region of Bax, which is normally sequestered within the inactive structure. The molecular chaperone nucleophosmin was identified as a novel Bax-binding protein by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Reciprocal co-immunoprecipitation and proximity assays confirmed the Bax-nucleophosmin protein-protein interaction and verified that nucleophosmin only bound to activated conformationally altered Bax. Confocal microscopy in a cell-based apoptosis model, demonstrated that nucleophosmin translocation from nucleolus to cytosol preceded Bax movement. Specific knockdown of nucleophosmin expression using RNAi attenuated apoptosis as measured by mitochondrial cytochrome c release and activation of the caspase cascade. In a mouse model of ischaemic stroke, subcellular fractionation studies verified that nucleophosmin translocation occurred within 3 h, at a time before Bax translocation but after Bax conformational changes have occurred. Thus, we have elucidated a novel molecular mechanism whereby Bax becomes activated and translocates to the mitochondria to orchestrate mitochondrial dysfunction and apoptotic cell death, which opens new avenues for therapeutic intervention.

Tacrolimus (FK506) ameliorates skilled motor deficits produced by middle cerebral artery occlusion in rats

BACKGROUND AND PURPOSE

Tacrolimus (FK506) is a potent immunosuppressant that is presently in clinical use for prevention of allograft rejection. Recently, animal studies reporting significant reductions in the volume of tissue damage associated with cardiac, hepatic, and cerebral ischemia suggest that tacrolimus may also be of use in the clinical management of stroke. In the present study, we examine whether the neuroprotective effects of tacrolimus, as assessed by histological outcome, are accompanied by an amelioration of the skilled motor deficits induced in the rat by middle cerebral artery occlusion (MCAO).

METHODS

Animals were trained to perform a skilled paw-reaching task before MCAO by perivascular microinjections of endothelin-1. Tacrolimus (1 mg/kg, n = 6) or vehicle (n = 6) was administered by intravenous infusion 1 minute after MCAO. After a 5-day postoperative recovery period, the rats were retested for skilled paw-reaching ability for an additional 9 days.

RESULTS

In vehicle-treated rats, MCAO resulted in a profound bilateral impairment in skilled paw use. Rats treated with tacrolimus, although still impaired, performed significantly better than those treated with vehicle alone (P < .01). Histological analysis, 14 days after occlusion, confirmed the neuroprotective efficacy of tacrolimus with a 66% reduction in the volume of hemispheric brain damage produced by MCAO (P < .01).

CONCLUSIONS

The present studies show that tacrolimus not only protects neural tissue from focal cerebral ischemia but also significantly ameliorates the deficits in skilled motor ability produced by this lesion. These data provide further support for the view that tacrolimus may be of use in the treatment of stroke.

Outpatient ultrasound-guided palladium 103 brachytherapy for localized adenocarcinoma of the prostate: a preliminary report of 434 patients

OBJECTIVES

To assess the effectiveness of palladium 103 (Pd-103) brachytherapy in Stage T1 and T2 adenocarcinoma of the prostate.

METHODS

Charts of 474 patients treated between 1991 and 1996 with transperineal real-time ultrasound-guided Pd-103 implants were reviewed to assess post-treatment prostate-specific antigen (PSA) levels and follow-up biopsy results. Of 474 patients, 434 had sufficient data for this report. The implant technique used allows precise placement of seeds and accurate dose delivery of the entire prostate. Preoperative neoadjuvant leuprolide (Lupron) and flutamide (Eulexin) were given selectively to reduce prostate size greater than 50 cc and for Gleason grade lesions greater than 7.

RESULTS

Of 434 patients, successful cancer control was demonstrated in 81% of patients by a decrease in PSA levels to less than 1.5 ng/mL at 1 year. Biopsies were negative in 88% of patients 1 year after the procedure and in 89% at 2 years. Analysis of the data suggests that patients with pretreatment PSA levels less than 10 ng/mL had the best outcomes. There were no disease-related deaths; the predominant morbidity was short-term bladder and bowel irritation without permanent sequelae. Incontinence occurred in less than 5% of patients who had undergone prior transurethral resection of the prostate. Impotence occurred in less than 15% of patients.

CONCLUSIONS

The technique used in this study proved effective in reducing PSA levels to less than 1.5 ng/mL and in producing negative biopsies 1 and 2 years postoperatively. Results are comparable to external-beam radiation therapy, demonstrating a significant reduction in morbidity.

Alterations in hippocampal function following repeated exposure to the amphetamine derivative methylenedioxymethamphetamine ("Ecstasy")

The effect of the psychomotor stimulant, 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy"), upon integrated cerebral function was measured in rats using the quantitative [14C]deoxyglucose autoradiographic technique. Animals were injected with MDMA (20 mg/kg sc) twice daily for 4 days. Fourteen days after the final administration, [3H]-paroxetine binding to 5HT uptake sites was reduced by 89% in membranes prepared from tissue samples of frontal cortex. In the same rats [3H]-paroxetine binding autoradiography revealed heterogeneity in the regional distribution of 5-HT uptake site depletion within neocortex (0-92%) and hippocampus (30-95%). Despite these profound reductions in 5-HT uptake sites no significant alterations were found in glucose utilisation in any area of neocortex examined. However, significant increases in glucose use were found in subregions of the hippocampus, most notably within the pyramidal cell layer of CA2 and CA3 (25-35%). This study provides direct evidence that the loss of 5-HT innervation caused by exposure to MDMA results in lasting functional changes in hippocampus.

Endothelin-1 induced middle cerebral artery occlusion: pathological consequences and neuroprotective effects of MK801

In the present study we utilise the potent vasoconstrictor properties of endothelin-1 (Et-1) in a new model of middle cerebral artery occlusion in the anaesthetized rat. We evaluate the reproducibility of the model and examine the neuroprotective efficacy of the potent anti-ischaemic agent, MK801. Adult male SD rats received MK801 (5 mg/kg, n = 7) or saline vehicle (n = 7) 30 mins prior to the microinjection of Et-1 (60 pmol in 3 microliters) via a 31-g cannula stereotaxically positioned 0.5 mm above the middle cerebral artery. Three days after the injection of Et-1, rats were perfusion fixed, the brain removed, cryostat sectioned and processed for histological staining. Sections at eight predetermined levels were examined by light microscopy and the volume of infarction calculated. Following administration of Et-1, saline-pretreated rats exhibited a pattern of ischaemic damage similar to that previously reported following permanent occlusion of the rat middle cerebral artery. This pattern was characterised by a large volume of infarction covering the dorsal and lateral neocortex (98 +/- 12 mm3) and striatum (32 +/- 3 mm3) ipsilateral to the insult. Power analysis predicted a group size of 7 would be required for a 50% reduction in ischaemic damage to be recorded as statistically significant at the 5% level. Pretreatment with MK801 reduced cortical tissue damage by 51% (P = 0.026) but did not significantly alter either the pattern or volume of infarction (33 +/- 4 mm3; P = 0.95) in the striatum.(ABSTRACT TRUNCATED AT 250 WORDS)

A retrospective cohort study of military deployment and postdeployment medical encounters for respiratory conditions

Deployed military personnel are exposed to inhalational hazards that may increase their risk of chronic lung conditions. This evaluation assessed associations between Operation Iraqi Freedom (OIF) deployment and postdeployment medical encounters for respiratory symptoms and medical conditions. This retrospective cohort study was conducted among military personnel who, between January 2005 and June 2007, were deployed to either of two locations with burn pits in Iraq, or to either of two locations without burn pits in Kuwait. Incidence rate ratios (IRRs) were estimated using two nondeployed reference groups. Rates among personnel deployed to burn pit locations were also compared directly to those among personnel deployed to locations without burn pits. Significantly elevated rates of encounters for respiratory symptoms (IRR = 1.25; 95% confidence interval [CI]: 1.20-1.30) and asthma (IRR = 1.54; 95% CI: 1.33-1.78) were observed among the formerly deployed personnel relative to U.S.-stationed personnel. Personnel deployed to burn pit locations did not have significantly elevated rates for any of the outcomes relative to personnel deployed to locations without burn pits. These results are consistent with the hypothesis that OIF deployment is associated with subsequent risk of respiratory conditions. Elevated medical encounter rates were not uniquely associated with burn pits.

Vasomotor responses of cerebral arterioles in situ to putative dopamine receptor agonists

The vasomotor responses of individual cerebral pial arterioles on the convexity of the cerebral cortex to subarachnoid perivascular micro-injections of dopamine and the putative dopamine receptor agonists, apomorphine, SKF 38393 and LY 141865, have been examined in 38 anaesthetized cats. The perivascular microapplication of dopamine (10(-9)-10(-3)M) effected dose-dependent reductions in pial arteriolar calibre, with the maximum reductions in calibre (22 +/- 2% from preinjection levels: mean +/- s.e.) being observed at 10(-3)M. The cerebrovascular constriction produced by dopamine (10(-5)M) could be significantly attenuated by the concomitant perivascular administration of phentolamine (10(-6)M) or methysergide (10(-6)M). The perivascular microapplication of apomorphine (10(-8)-10(-4)M) effected dose-dependent increases in arteriolar calibre, with the maximum increase (31 +/- 6%) being observed with apomorphine (10(-5)M). The perivascular administration of the putative dopamine D1-receptor agonist, SKF 38393 (10(-9)-10(-4)M) increased arteriolar calibre, with the maximum response (24 +/- 3%) being observed with injection of 10(-7)M. The putative dopamine D2-receptor agonist, LY 141865, also increased cerebral arteriolar calibre, but only at high concentrations (maximum calibre increase 25 +/- 6.1 with 10(-4)M). The cerebrovascular dilatations elicited by apomorphine and by SKF 38393 were markedly attenuated by the concomitant perivascular microapplication of the putative dopamine D1-receptor antagonist, SCH 23390 (10(-8)M). The perivascular administration of SCH 23390 (10(-9)-10(-5)M) per se did not alter arteriolar calibre nor the arteriolar dilatation provoked by microinjections of acidic cerebrospinal fluid. These results point to the presence on cat cerebral arterioles of dopamine receptors (probably of D1 subtype) mediating dilation.

Chronic 3,4-methylenedioxymethamphetamine administration decreases glucocorticoid and mineralocorticoid receptor, but increases 5-hydroxytryptamine1C receptor gene expression in the rat hippocampus

Both glucocorticoids and serotonin have been implicated in the regulation of mood and neuroendocrine control. In this study we have examined the effects of the psychomotor stimulant, 3,4-methylenedioxymethamphetamine on corticosteroid and 5-hydroxytryptamine receptor subtype gene expression within the hippocampal formation using in situ hybridization histochemistry. Animals were injected subcutaneously with 3,4-methylenedioxymethamphetamine (20 mg/kg) twice daily for four days. Two weeks following this dosage regimen, shown to markedly reduce 5-hydroxytryptamine terminals, both glucocorticoid receptor and mineralocorticoid receptor messenger RNA expression were significantly decreased (30-47% fall) in the granule cells of the dentate gyrus and pyramidal cells of CA1-CA4 fields of Ammon's horn, but not in parietal cortex neurons. In the same rats, 5-hydroxytryptamine1C receptor messenger RNA expression was significantly increased in CA3 pyramidal neurons (133% rise), but neither 5-hydroxytryptamine1A or 5-hydroxytryptamine2 receptor messenger RNA levels were altered in any dorsal hippocampal subfield. 3,4-Methylenedioxymethamphetamine treatment was associated with modest hypersecretion of coricosterone during the diurnal nadir, without other peripheral evidence of chronic glucocorticoid excess (unchanged thymic and adrenal weights and corticosterone-binding globulin levels). These results emphasize the importance of the serotonergic innervation in maintaining hippocampal corticosteroid receptor gene expression. It is suggested that 5-hydroxytryptamine1C receptors may be involved in mediating the effects of serotonin on hippocampal glucocorticoid receptor and mineralocorticoid receptor expression and perhaps mood.

Behavioural assessment of endothelin-1 induced middle cerebral artery occlusion in the rat

The behavioural effects of unilateral middle cerebral artery occlusion (MCAO) induced by perivascular injection of endothelin, and a unilateral excitotoxic lesion of the striatum, were explored using the staircase test of skilled paw-reaching in the rat. A profound bilateral impairment in pellet recovery, with a concomitant increase in pellet displacement, was observed in the MCAO group. By contrast the striatal lesion group exhibited a primarily contralateral impairment. The findings provide both further insight into the control of unilateral motor function and a reliable behavioural endpoint for the assessment of experimental stroke.

Acute cocaine administration: effects on local cerebral blood flow and metabolic demand in the rat

Local cerebral blood flow and glucose utilisation were measured in both saline (n = 10) and cocaine (10 mg/kg; n = 10) treated rats using [14C]iodoantipyrine and [14C]2-deoxyglucose quantitative autoradiography respectively. In control animals, the ratio of flow to metabolism was 1.40 (r = 0.92) for the 40 brain regions examined. Cocaine treatment altered neither the correlation (r = 0.83) nor the ratio (1.49). Thus, the fundamental relationship between CBF and metabolism remains intact following acute cocaine exposure.

Postdeployment Respiratory Health Care Encounters Following Deployment to Kabul, Afghanistan: A Retrospective Cohort Study

Inhalational hazards are numerous in operational environments. A retrospective cohort study was conducted to investigate associations between deployment to Kabul, Afghanistan and subsequent respiratory health among U.S. military personnel. The study population consisted of personnel who deployed to Kabul, select Operation Enduring Freedom locations, personnel stationed in the Republic of Korea, and U.S.-stationed personnel. Incidence rate ratios (IRRs) were estimated for respiratory symptoms, signs, and ill-defined conditions, asthma, and chronic obstructive pulmonary disease. A significantly elevated rate of symptoms, signs, and ill-defined conditions was observed among Kabul-deployed personnel compared to personnel deployed or stationed in Bagram (IRR 1.12; 95% confidence interval [CI], 1.05-1.19), Republic of Korea (IRR 1.20; 95% CI, 1.10-1.31), and the United States (IRR 1.52; 95% CI, 1.43-1.62). A statistically elevated rate of asthma was observed among personnel deployed to Kabul, relative to U.S.-stationed personnel (IRR 1.61; 95% CI, 1.22-2.12). Statistically significant rates were not observed for chronic obstructive pulmonary disease among Kabul-deployed personnel compared to other study groups. These findings suggest that deployment to Kabul is associated with an elevated risk of postdeployment respiratory symptoms and new-onset asthma.

Cerebrovascular and functional consequences of 5-HT1A receptor activation

Cerebral glucose utilization and blood flow were measured in rats using 2-deoxy-D-[14C]glucose and [14C]iodoantipyrine quantitative autoradiography, respectively, following treatment with the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT). In control and 8-OH-DPAT-treated animals blood flow and glucose use were similarly correlated, but the ratio was increased following 8-OH-DPAT treatment. Since 5-HT1A receptor activation is known to reduce neuronal 5-HT release, these results are consistent with a vasoconstrictor role for endogenous serotonin.

Evidence for a possible role for serotonergic systems in the control of cerebral blood flow

Cerebral blood flow and glucose utilisation were measured in rats using [14C]iodoantipyrine and [14C]2-deoxyglucose quantitative autoradiography respectively following repeated exposure to the serotonergic neurotoxin methylenedioxyamphetamine. In both control and treated animals blood flow and glucose use were similarly correlated but the ratio was increased following lesion. Some focal increases in flow were greatly in excess of metabolic demand. These results are consistent with a cerebrovascular vasoconstrictor role for serotonin.

Minimally invasive treatment for localized adenocarcinoma of the prostate: review of 1048 patients treated with ultrasound-guided palladium-103 brachytherapy

PURPOSE

To assess the effectiveness of palladium-103 brachytherapy in stage T1 and T2 adenocarcinoma of the prostate.

PATIENTS AND METHODS

The charts of 1048 patients treated between 1991 and 1999 with transperineal realtime ultrasound-guided (103)Pd (Theraseed) implants were reviewed to assess the effects on serum prostate specific antigen (PSA) values and tissue (biopsy). Of the 1048 patients, 780 had sufficient data for this report. Preoperative total androgen blockade (leuprolide and flutamide) was used selectively in patients whose prostate size was >50 cc and those whose tumors had a Gleason score of >7.

RESULTS

At 1 year, 86% of the evaluable 766 patients had stable PSA concentration <1.5 ng/mL; at 5 years, 86% of the 166 patients with data available had stable PSA values <1.5 ng/mL. Biopsies were negative in 92% of the patients studied at 2 years. Patients with pretreatment PSA values <10 ng/mL had the best outcomes, and those treated with (103)Pd plus hormone ablation achieved PSA reduction more rapidly than those treated with radioisotope monotherapy. There was one disease-related death; the principal morbidity was short-term bladder and bowel irritation without permanent sequelae. Impotence occurred in approximately 15% of patients, and incontinence occurred in 5% of those who had undergone prior transurethral resection of the prostate.

CONCLUSION

The technique used in this study proved effective in reducing PSA concentrations to <1.5 ng/mL and in producing negative biopsies 1 and 2 years postoperatively. These results are comparable to those of external-beam radiation therapy and radical prostatectomy while demonstrating a significant reduction in morbidity.

Glycyrrhetinic acid, an inhibitor of 11 beta-hydroxysteroid dehydrogenase, alters local cerebral glucose utilization in vivo

11 beta-Hydroxysteroid dehydrogenase (11 beta-OHSD) metabolizes corticosterone (B) to inactive 11-dehydrocorticosterone and thus protects the non-specific renal mineralocorticoid receptor from exposure to B in vivo. There is regional 11 beta-OHSD mRNA expression and bioactivity in brain in vitro, but any in vivo function is unknown. We used the [14C]2-deoxyglucose technique in conscious rats to investigate whether 11 beta-OHSD inhibition with glycyrrhetinic acid alters local cerebral metabolic activity. We found increased glucose use in subregions of the hypothalamus, hippocampus, neocortex and subthalamus. Thus, 11 beta-OHSD may play a role in regulating the effects of B in the brain, in vivo.