Spatially distributed scintillator arrays for diagnosing runaway electron transport and energy behavior in tokamaks

We present details of a new bismuth germanate [Bi(4)Ge(3)O(12) (BGO)] scintillator array used to diagnose the transport and energy behavior of runaway electrons (REs) in DIII-D. BGO exhibits important properties for these compact detectors including high light yield which sufficiently excites photodiode detectors (8500 photons/MeV), high density and atomic numbers of constituent materials which maximizes sensitivity, and relative neutron blindness which minimizes complications in data interpretation. The detectors observe primarily hard x-ray radiation emitted in a forward beamed pattern by RE when they strike first wall materials or bulk ions and neutrals in the plasma, although we also address photoneutron signals. The arrangement of the array enables time resolved location of x-ray emission and associated asymmetries which help identify instabilities and confinement properties of RE. By shielding a subset of detectors with different thicknesses of lead, and with interpretative support of the code EGSNRC, we also measure RE energy, although due to the often distributed nature of RE strike points and the forward beamed character of emitted hard x-rays, we restrict interpretation as a lower bound for RE energy.

Quenching of the nonlocal electron heat transport by large external magnetic fields in a laser-produced plasma measured with imaging thomson scattering

We present a direct measurement of the quenching of nonlocal heat transport in a laser-produced plasma by applying large external magnetic fields (>10 T). The temporally resolved Thomson-scattering measurements of the electron temperature profile show that the heat front propagation transverse to a high-power laser beam is slowed resulting in extremely strong local heating. We find agreement with hydrodynamic modeling when including a magnetic field model that self-consistently evolves the fields in the plasma.

Ocular syphilis in HIV-positive patients receiving highly active antiretroviral therapy

BACKGROUND

From October 2001 to October 2002, we have observed a surprisingly high incidence of ocular syphilis in human immunodeficiency virus-positive (HIV+) patients receiving highly active antiretroviral therapy at our clinic.

METHODS

We conducted a retrospective chart and patient database review.

RESULTS

From 1997 to 2002, 455 patients in our clinic were screened for syphilis; 320 were screened from 2001 to 2002; 7.3% of patients (33/455) were diagnosed with syphilis. During the past year, syphilis was diagnosed in 7.5% of patients (24/320), of whom 13% (3/24) had ocular syphilis. We estimate the prevalence of ocular syphilis in HIV+ patients on highly active antiretroviral therapy screened for syphilis to be 9% (3/33). Presenting symptoms included blurred vision, loss of vision, central scotomas, and bilateral ocular involvement. The most common ocular manifestation of syphilis was posterior chamber uveitis; one patient also had a retinal detachment. All patients demonstrated reactive rapid plasma reagin and fluorescent treponemal antibody absorption test results, cerebrospinal fluid pleocytosis, and elevated total protein. Each patient received a 21-day course of intravenous penicillin G (24 million units daily) with improvement of visual symptoms.

CONCLUSION

Our data demonstrate an unexpectedly high incidence of ocular syphilis in our HIV+ patients receiving highly active antiretroviral therapy during the past year. A diagnosis of ocular syphilis should be considered in any HIV+ patient who presents with visual symptoms, irrespective of the patient's CD4 count.

Reporting of deaths during pre-approval clinical trials for advanced HIV-infected populations

The Division of Antiviral Drug Products of the US FDA has regulatory authority over the investigational new drugs under development by various sponsors to treat HIV-infected populations. The FDA and the sponsors of investigational new drugs use the Code of Federal Regulations to guide the entire drug development process, in order to ensure that safe and efficacious drugs are brought to market. To achieve this goal, diligent monitoring for safety during the pre-approval phase of new drug development is particularly crucial. When deciding what adverse experiences on clinical trials should be expeditiously reported, the Division recommends a conservative interpretation of the Code of Federal Regulations, where an adverse experience in a clinical trial of advanced HIV-infected patients is considered to be 'associated with the use of the drug' when the relationship cannot be ruled out with objective evidence. Fatal adverse experiences for subjects on clinical trials should be especially scrutinised. Safety reporting should be expedited when death occurs during clinical trials of advanced HIV-infected populations. The three components of an expedited reportable death occurrence, namely 'serious', 'unexpected' and 'associated with the drug use' as they relate to advanced HIV-infected populations, are discussed in this article. An occurrence of death is by definition serious. Unexpected experiences are unlisted adverse experiences, but need to be put into the context of specificity and severity. 'Associated with the drug use' has been clarified as 'relationship to the drug cannot be ruled out'. Because death in the advanced HIV-infected/AIDS population is usually a complex event, the possible contribution of the study drug is difficult to rule out. Thus, if the three components of the reporting requirement are met or insufficient information is available to make a firm determination of causality by the seventh day of the reporting period, the Division of Antiviral Drug Products expects expedited death reports on subjects participating in investigational new drug clinical studies.

Effects of the selective serotonin reuptake inhibitor, fluoxetine, on regional gastric contractility

Selective serotonin reuptake inhibitors (SSRIs) are increasingly used to treat a variety of disorders but have gastrointestinal side-effects.

AIM

To determine the effects of the SSRI, fluoxetine, on gastric smooth muscle contractility.

METHODS

Fundic, antral, and pyloric circular muscle contractility of guinea pig muscle strips were measured in vitro. Fluoxetine was added in concentrations from 0.1 nmol L(-1) to 100 mumol L(-1). Receptor antagonists were used to determine the neural pathways involved.

RESULTS

Fluoxetine caused concentration dependent contractions, which were greatest in fundus compared with the antrum or pylorus. The contractile effects of fluoxetine in the antrum were reduced by tetrodotoxin, atropine, phentolamine, and the 5-HT(4) receptor antagonist GR 113808. The contractile effects of fluoxetine in the fundus were reduced by atropine, phentolamine, and GR 113808.

CONCLUSIONS

Fluoxetine affects gastric contractility with regional variability - contracting the fundus more than the antrum or pylorus. The fluoxetine contractile effect is reduced by tetrodotoxin, atropine, phentolamine, and a 5-HT(4) receptor antagonist. These results suggest fluoxetine interacts with muscarinic, alpha-adrenergic, and serotoninergic receptors and/or ongoing reuptake/release of serotonin in the stomach.

Effects of clonidine and tricyclic antidepressants on gastric smooth muscle contractility

To determine if and how clonidine and tricyclic antidepressants affect gastric contractility. Guinea pig fundic and antral circular muscle strips were studied in vitro. The effects of clonidine or amitriptyline added in graded concentrations on contractions to electric field stimulation (EFS), acetylcholine (ACh), and SP in the presence of N(epsilon)-nitro-l-arginine methyl ester (l-NAME) were studied. EFS produced frequency dependent contractions of fundic and antral muscle that were abolished by atropine or tetrodotoxin (TTX). ACh contractions were abolished by atropine but not TTX. Clonidine reduced contractile response to EFS but had no effect on ACh contractions. The threshold concentration of clonidine to inhibit EFS contractions was lower in the fundus than in the antrum. Amitriptyline reduced contractions to both EFS and ACh but not to SP. The threshold concentration of amitriptyline to inhibit EFS contractions was lower in the antrum than in the fundus. Both clonidine and amitriptyline affect gastric contractility. At threshold concentrations, clonidine affects fundic contractility whereas amitriptyline affects antral contractility. Clonidine affects gastric contractility in response to EFS but not to ACh, suggesting alpha-2 receptors on cholinergic nerves that reduce ACh release. Amitriptyline inhibits gastric contractility to EFS and ACh suggesting an inhibitory muscle effect.

Cloned transgenic offspring resulting from somatic cell nuclear transfer in the goat: oocytes derived from both follicle-stimulating hormone-stimulated and nonstimulated abattoir-derived ovaries

The use of nuclear transfer (NT) techniques to create transgenic offspring capable of producing valuable proteins may have a major impact on the pharmaceutical market. Our objective was to compare the in vivo developmental potential of NT embryos produced from the fusion of transgenic donor cells with cytoplasts prepared from either FSH-stimulated ovaries or nonstimulated abattoir-derived ovaries. Donor cells were prepared from a transgenic fetus carrying the gene for human antithrombin III as a marker and used within four to eight subpassages. Cells were serum deprived for 4 days prior to cytoplast transfer. Oocytes were enucleated by removing the metaphase plate using a DNA stain and epifluorescent illumination. Donor cells were fused to enucleated oocytes by electric pulse and then chemically activated. There was no difference in the number of transferable embryos produced from cytoplasts of FSH-stimulated ovaries or from the fusion of cytoplasts from abattoir ovaries, nor was there a difference in the number of pregnancies established per recipient with either treatment. All pregnancies from both groups culminated in the births of healthy female kids (five total). To our knowledge, this is the first report of cloned goats produced from NT using cytoplasts derived from abattoir ovaries.

Effect of indomethacin on gallbladder inflammation and contractility during acute cholecystitis

OBJECTIVE

The aim of this study was to determine whether the prostaglandin synthase inhibitor indomethacin reverses the inflammation and abnormal gallbladder contractility that occur after common bile duct ligation (CBDL), a model of acute cholecystitis.

METHODS

Gallbladder muscle contractility was studied in vitro in normal, CBDL, and sham-operated guinea pigs. Animals were treated with saline or indomethacin in vivo. Acetylcholine (ACh) was used to directly contract the muscle and electric field stimulation (EFS) to activate intrinsic nerves. Hematoxylin and eosin-stained slides of muscle strips were scored for inflammation.

RESULTS

CBDL in saline-treated animals increased the inflammation score and decreased gallbladder muscle contractility to ACh and EFS. Indomethacin decreased the inflammation score and partly reversed the smooth muscle contractile response to ACh 6 and 24 h after CBDL, but not at 48 h. Indomethacin did not reverse the CBDL-induced decrease in nerve-evoked contractions.

CONCLUSION

Gallbladder inflammation and contractile dysfunction after CBDL are partly reversed with indomethacin at 6 and 24 h, but not at 48 h. This suggests that, early in the course of CBDL, the inflammation and contractile dysfunction are, in part, prostaglandin-mediated.

The contractile action of platelet-activating factor on gallbladder smooth muscle

Platelet-activating factor (PAF) may be a mediator of some sequelae of cholecystitis, a disorder with gallbladder motor dysfunction. The aims of this study were to determine the effect and mechanism of PAF on gallbladder muscle. Exogenous administration of PAF-16 or PAF-18 caused dose-dependent contractions of gallbladder muscle strips in vitro with threshold doses of 1 ng/ml and 10 ng/ml, respectively. The PAF-induced contractions were not significantly reduced by TTX, atropine, or hexamethonium but were significantly inhibited with the PAF receptor antagonists ginkolide B and CV-3988. The PAF-induced contraction was reduced by indomethacin. Preventing influx of extracellular calcium with a calcium-free solution nearly abolished the PAF contractile response. Nifedipine inhibited the PAF contractile response, whereas ryanodine had no effect. Pertussis toxin reduced the PAF contractile response. In conclusion, PAF causes gallbladder contraction through specific PAF receptors on gallbladder muscle. These PAF receptors appear to be linked to a prostaglandin-mediated mechanism and to pertussis toxin-sensitive G proteins. The contractile response is largely mediated through the utilization of extracellular calcium influx through voltage-dependent calcium channels.

Effect of acalculous cholecystitis on gallbladder neuromuscular transmission and contractility

BACKGROUND

Impaired smooth muscle contractility is important in the pathophysiology of acalculous cholecystitis. Common bile duct ligation (CBDL) is a model of acalculous cholecystitis, producing acute inflammatory changes and decrease in gallbladder smooth muscle contractility. The aim of this study was to determine whether there is coexistent dysfunction of neural efferent motor pathways of the gallbladder after CBDL.

MATERIALS AND METHODS

Gallbladder muscle contractility was studied in vitro in normal, CBDL, and sham-operated guinea pigs. Electric field stimulation (EFS; 2-16 Hz) was used to activate intrinsic nerves and exogenous acetylcholine (ACh) was used to directly stimulate the muscle. H&E-stained slides of muscle strips were scored for inflammatory changes.

RESULTS

After CBDL, there was a progressive increase in the inflammation score and decrease in gallbladder muscle contractility to ACh. There was also a progressive decline in EFS-induced contractility when expressed as absolute force or normalized to the maximal muscle contractile response to ACh. The nitric oxide synthase inhibitor l-NNA (10 microM) increased EFS-induced contractions by 50 +/- 25% (P = 0.05) in CBDL animals but had no effect in sham surgical controls.

CONCLUSIONS

CBDL with its acute gallbladder inflammation affects gallbladder contractility by two mechanisms: (1) decreased smooth muscle contractility, and (2) decreased neurally mediated contractions. The neurally mediated alterations result from dysfunction of cholinergic excitatory nerves and upregulation of nitric-oxide-mediated inhibition of smooth muscle contractility.

Health-related quality of life in Australian men remaining disease-free after radical prostatectomy

OBJECTIVE

To determine the health-related quality of life (HRQOL) of Australian men after radical prostatectomy.

DESIGN

Cross-sectional study.

SETTING

Private and public practices of three urologists in south-east Queensland, July 1989 to June 1995.

PARTICIPANTS

140 men with no evidence of disease recurrence 1 to 6 years after radical prostatectomy.

MAIN OUTCOME MEASURES

Voiding and erectile potency and HRQOL. Recall of preoperative status and status at survey were established by an independently administered multi-item questionnaire.

RESULTS

112 men (80%) completed the study questionnaire. Difficulty with bladder control before the operation was reported by 25 (22%; 95% confidence interval [CI], 15%-31.2%), and the incontinence rate after treatment was 22/112 (20%; 95% CI, 12.7%-28.2%). Men with incontinence after operation were more likely to recall preoperative urinary symptoms. Eighty-four (75%) men were happy or coping with their sexual function after radical prostatectomy despite an erectile potency rate of only 12% (95% CI, 7%-20%). Twenty-eight (25%) had tried penile injections and three have had penile prostheses since their operation. Impotence was reported more frequently (40%) as the treatment-related problem most affecting life, followed by "concern about cancer" (12%) and incontinence (8%). Impotence was also the most common cause given for diminished HRQOL.

CONCLUSIONS

Loss of sexual function after radical prostatectomy is more commonly perceived as a major problem and is more likely than urinary incontinence to adversely affect HRQOL. Loss of sexual function and its effect on HRQOL needs to be given greater emphasis in counselling before radical prostatectomy.

Extracorporeal shock wave lithotripsy for ureteric calculi with the Dornier MFL5000 lithotriptor at a multi-user centre

We have reviewed 241 consecutive cases of ureteric calculi managed with the Dornier MFL5000 lithotriptor. The patients were individually managed by 24 visiting urologists between October 1990 and September 1991. There were 153 cases of upper ureteric calculi, of which 59 were successfully manipulated back to the renal pelvis prior to treatment, and 94 were treated in situ. There were 27 mid-ureteric and 61 lower ureteric cases; in 51% of stones treated in situ ureteric stents were placed prior to extracorporeal shock wave lithotripsy. All stones were radio-opaque and localised with on-line fluoroscopy. The outcome of treatment was assessed at 3 months, with failure defined as residual calculi > or = 4 mm. The follow-up rate was 89%. The overall fragmentation rate after a single treatment was 72%, which increased to 81% with re-treatment. Of the upper ureteric calculi, manipulated stones had a significantly higher fragmentation rate (85%) compared with in situ stones (63%). The fragmentation rate was 89% for mid-ureteric stones and 71% for lower ureteric stones. Factors that significantly influenced fragmentation were retrograde manipulation of stone, number of impulses delivered and age of the patient. Stone size, the presence of a ureteric stent and mode of anaesthesia did not significantly influence fragmentation. These results suggest the Dornier MFL5000 lithotriptor is effective for the management of ureteric calculi in a multi-user setting.