Single π 0 production off neutrons bound in deuteron with linearly polarized photons.

The quasifree γ → d → π 0 n ( p ) photon beam asymmetry, Σ , has been measured at photon energies, E γ , from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time. The data were collected in the A2 hall of the MAMI electron beam facility with the Crystal Ball and TAPS calorimeters covering pion center-of-mass angles from 49 ∘ to 148 ∘ . In this kinematic region, polarization observables are sensitive to contributions from the Δ ( 1232 ) and N(1440) resonances. The extracted values of Σ have been compared to predictions based on partial-wave analyses (PWAs) of the existing pion photoproduction database. Our comparison includes the SAID, MAID and Bonn-Gatchina analyses; while a revised SAID fit, including the new Σ measurements, has also been performed. In addition, isospin symmetry is examined as a way to predict π 0 n photoproduction observables, based on fits to published data in the channels π 0 p , π + n and π - p .

Beam-Target Helicity Asymmetry for γ[over →]n[over →]→π

We report the first beam-target double-polarization asymmetries in the γ+n(p)→π^{-}+p(p) reaction spanning the nucleon resonance region from invariant mass W=1500 to 2300 MeV. Circularly polarized photons and longitudinally polarized deuterons in solid hydrogen deuteride (HD) have been used with the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The exclusive final state has been extracted using three very different analyses that show excellent agreement, and these have been used to deduce the E polarization observable for an effective neutron target. These results have been incorporated into new partial wave analyses and have led to significant revisions for several γnN^{*} resonance photocouplings.

Two new species and a new phyllobothriid cestode genus from sharks of the genus Negaprion Whitley (Carcharhiniformes).

Alexandercestus n. g. (Cestoda: Tetraphyllidea) is erected for two cestode species found parasitising the two known species of lemon sharks (Carcharhiniformes: Negaprion spp.). This new genus differs from all other phyllobothriid genera except for Hemipristicola Cutmore, Theiss, Bennett & Cribb, 2011, Marsupiobothrium Yamaguti, 1952, Nandocestus Reyda, 2008, Orectolobicestus Ruhnke, Caira & Carpenter 2006, Orygmatobothrium Diesing, 1863, Paraorygmatobothrium Ruhnke, 1994 and Phyllobothrium van Beneden, 1849 in possessing uniloculate bothridia with an apical sucker and neck scutes. Alexandercestus differs from Orectolobicestus and Nandocestus in lacking marginal loculi on the bothridia, from Paraorygmatobothrium in possessing uninterrupted vitelline follicles at the level of the ovary and from Phyllobothrium in being euapolytic as opposed to anapolytic and in lacking posteriorly bifid bothridia. The new genus lacks the central accessory bothridial organ seen in specimens of Orygmatobothrium, and lacks the central bothridial accessory sucker of specimens of Marsupiobothrium. Alexandercestus spp. compare most favourably with specimens of Hemipristicola, especially with respect to aspects of proglottid morphology, but differ in possessing aristate gladiate spinitriches rather than serrate gladiate spinitriches on the proximal bothridial surface. In addition, the bothridia of Alexandercestus spp. are comparatively more fleshy and foliose than those in specimens of Hemipristicola. Two new species of Alexandercestus n. g. are described, Alexandercestus gibsoni n. sp. from Negaprion acutidens, collected from off northern Australia and the Marshall Islands, and Alexandercestus manteri n. sp. from N. brevirostris, collected off the islands of Bimini and the Florida Keys. The two new species differ in total length and vitelline follicle distribution. Bayesian inference and parsimony analysis of the D1-D3 region of the large nuclear ribosomal DNA of 17 published and seven novel sequences placed A. gibsoni as the sister taxon to a clade containing Hemipristicola gunterae Cutmore, Theiss, Bennett & Cribb, 2011 and species of Paraorygmatobothrium. This result supports the erection of Alexandercestus as a genus separate from Hemipristicola and Paraorygmatobothrium. At the present time, species of Alexandercestus are known only from hosts of the carcharhinid genus Negaprion Whitley; examination of extensive survey data suggests this may be the extent of the host distribution of this genus.

Extraction and STM Imaging of Spherical Giant Fullerenes.

High-temperature, high-pressure extracts of soot produced by the Krätschmer-Huffman technique (KH carbon) were characterized by mass spectrometry and imaging with scanning tunneling microscopes (STMs). The mass spectra of these samples are similar to those of ambient-pressure, high-boiling-point solvent extractions, supporting the idea that solvent temperature and possibly pressure are key parameters in extraction of the giant fuilerenes. The STM images show that the giant fullerenes in these samples are roughly spherical in shape and range in diameter from approximately 1 to 2 nanometers, corresponding to fullerenes containing 60 to 330 atoms. No evidence of bucky tubes was found.

Contribution of acquired meticillin-resistant Staphylococcus aureus bacteraemia to overall mortality in a general intensive care unit.

During a period of 11 years, 77 patients had meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia > or =5 days after admission to the intensive care unit (ICU). Ten had no prior growth of MRSA, 13 had positive screens on admission and 54 initially tested negative for MRSA in ICU before positive blood culture. These 54 constituted 20.2% [95% confidence interval (CI): 15.6-25.0] of 267 who acquired MRSA > or =5 days after admission. Mortality among 77 patients with MRSA bacteraemia was 57.1% (46.0-68.2). Nineteen of these 77 patients with MRSA bacteraemia had growth of a second pathogen from blood. Those with only MRSA bacteraemia were each matched with five controls by diagnosis and initial Acute Physiological and Chronic Health Evaluation II score. Mortality was greater in bacteraemic patients [53.6% (40.5-66.7)] than in controls [31.8% (26.3-37.3)] [relative risk (RR) 1.69 (1.25-2.26), P < 0.01], implying an additional absolute mortality of 21.8% (8.0-40.1). Application of this estimate to all 77 patients suggests that ICU-acquired MRSA bacteraemia caused 17 (6-31) deaths, adding 0.3% (0.1-0.6) to the 30.1% hospital mortality of all admissions. Incidence of MRSA bacteraemia increased with length of stay, contributing an estimated 3.1% (1.1-5.7) towards 37.9% mortality of the 198 patients remaining > or =25 days. These data emphasise the importance of preventing initial MRSA colonisation/infection of long-stay patients.

Tolerance to the humoral and hemodynamic effects of caffeine in man.

Acute caffeine in subjects who do not normally ingest methylxanthines leads to increases in blood pressure, heart rate, plasma epinephrine, plasma norepinephrine, plasma renin activity, and urinary catecholamines. Using a double-blind design, the effects of chronic caffeine administration on these same variables were assessed. Near complete tolerance, in terms of both humoral and hemodynamic variables, developed over the first 1-4 d of caffeine. No long-term effects of caffeine on blood pressure, heart rate, plasma renin activity, plasma catecholamines, or urinary catecholamines could be demonstrated. Discontinuation of caffeine ingestion after 7 d of administration did not result in a detectable withdrawal phenomenon relating to any of the variables assessed.

A role for the adrenal renin-angiotensin system in the regulation of potassium-stimulated aldosterone production.

Potassium is a major regulator of aldosterone production. It also increases adrenal renin. The causal relationship between potassium and adrenal renin is not known. To evaluate the role of the intraadrenal renin-angiotensin (ANG) system in potassium-stimulated aldosterone synthesis and release, specific adrenal renin activity, PRA, and plasma aldosterone were measured during potassium loading or captopril treatment in the rat. Adrenal ANGs were determined using a HPLC system combined with RIA to obtain quantitative information on the components of the adrenal renin-ANG system. In addition, the effect of pretreatment with captopril on aldosterone production by isolated adrenal glomerulosa cells was examined. In intact animals potassium loading markedly increased adrenal renin and plasma aldosterone, whereas PRA was suppressed. The administration of captopril to rats in normal potassium balance did not suppress plasma aldosterone. Captopril treatment during potassium loading inhibited the potassium-induced increase in aldosterone. Furthermore, pretreatment with captopril suppressed adrenal ANG II and reduced the response of aldosterone production to extracellular potassium concentration by isolated adrenal glomerulosa cells in vitro. These results suggest that the adrenal renin-ANG system plays a significant role in the control of aldosterone production under potassium stimulation.

Dexamethasone suppression testing in chronic renal failure: pharmacokinetics of dexamethasone and demonstration of a normal hypothalamic-pituitary-adrenal axis.

The status of the hypothalamic-pituitary-adrenal axis in chronic renal failure (CRF) was examined by dexamethasone suppression testing (DST) using oral overnight, oral and iv 8-h daytime, and standard 48-h oral dosage protocols. Based on data obtained after iv administration of dexamethasone, the daytime study was used to calculate pharmacokinetic parameters for dexamethasone (clearance, volume of distribution at steady state, and terminal t1/2). None of a group of seven uremic patients had suppressed plasma cortisol concentrations after administration of 1 mg dexamethasone, orally, the night before. Six normal subjects and six patients with CRF participated in the pharmacokinetic study. There was no significant difference between the groups with respect to clearance, volume of distribution at steady state, or t1/2 of dexamethasone, indicating that patients with CRF metabolize dexamethasone in a fashion similar to that of normal subjects. Daily patterns of plasma cortisol determined between 0800-1600 h on a day when dexamethasone was not administered were similar in normal subjects and CRF patients. However, the degree of suppression of plasma cortisol after dexamethasone was significantly greater in the normal subjects (P less than 0.01), possibly due to a prolonged cortisol t1/2 in CRF. Nevertheless, the CRF patients did have decreased plasma cortisol levels from 4-8 h after iv and from 4-7 h after oral dexamethasone. The bioavailability of dexamethasone was not significantly different between the groups. When 48-h oral DSTs were performed in the CRF group, four of five patients had normal responses. The one patient who did not suppress had low levels of plasma dexamethasone, presumably due to decreased gastrointestinal absorption of dexamethasone. These results indicate that the metabolism of dexamethasone is similar in CRF patients and normal subjects, that normal suppression of plasma cortisol can be achieved in uremia if the duration of dexamethasone administration is prolonged sufficiently to compensate for the prolongation of cortisol t1/2 in CRF, and that it is essential to measure plasma dexamethasone as well as cortisol levels to interpret the results of a DST in CRF patients.

Factitious hypercortisoluria.

A case of factitious hypercortisoluria due to the presumed addition of glucocorticoid to the urine collections is presented. The discrepancy between urine and blood steroid hormone levels first suggested that the patient had tampered with the urine collections. Plasma steroid hormone levels were normal, whereas the urinary free cortisol level fluctuated in a totally random fashion. Urinary 17-hydroxycorticosteroid and urinary free corticosterone levels were normal. Partition chromatography of the urine indicated that the cortisol immunoactivity coeluted with authentic cortisol. This study illustrates the value of multiple urinary and plasma steroid determinations, especially urinary or plasma corticosterone measurements, in suspected cases of factitious Cushing's syndrome.

Immunohistochemical evidence that angiotensins I and II are formed by intracellular mechanism in juxtaglomerular cells.

The existence of angiotensin II (AII) immunoreactivity in juxtaglomerular (JG) cells of rat kidney, which has been demonstrated previously by immunohistochemical studies, can be explained either as the product of intracellular synthesis or by the internalization of receptor-bound AII originating in plasma. To resolve these two alternative mechanisms, attempts were made to identify AI in JG cells of rat kidney by immunohistochemical staining using specific antibodies to AI. Although AI-like immunoreactivity was not detected in normal rat kidney, rats treated with the angiotensin-converting enzyme inhibitors, MK-421 or captopril, showed AI-like immunoreactivity in JG cells. The presence of renin and AII-like immunoreactivity was demonstrated in the same cells by specific antibodies to respective antigens used on adjacent serial sections. These findings support an intracellular mechanism of the formation of AII and suggest an intracellular renin angiotensin system, presumably separate from the extracellular system.

Association between low plasma levels of dexamethasone and elevated levels of cortisol in psychiatric patients given dexamethasone.

In psychiatric inpatients, positive results on 40 dexamethasone suppression tests (elevated cortisol levels) were strongly associated with low plasma levels of dexamethasone. Bioavailability or pharmacokinetic factors may contribute importantly to the outcome of the dexamethasone suppression test.

The dexamethasone suppression index: enhancement of DST diagnostic utility for depression by expressing serum cortisol as a function of serum dexamethasone.

The authors sought to determine whether the performance of the dexamethasone suppression test (DST) could be enhanced by expressing cortisol as a function of dexamethasone. Because cortisol concentration is a function of the reciprocal of dexamethasone concentration, this relationship was approximated by calculating the product of cortisol and dexamethasone as a dexamethasone suppression index. Preliminary assessment of test performance measures (sensitivity, specificity, and predictive power) showed that use of the dexamethasone suppression index was an improvement over the use of cortisol levels alone. Factoring dexamethasone levels into post-dexamethasone cortisol level measures may enhance the utility of neuroendocrine assessment in psychiatry.

Caffeine and hypertension.

The effect of prolonged caffeine administration on blood pressure in hypertensive subjects was assessed in a double-blind placebo-controlled study. Eighteen hypertensive subjects participated, nine of whom received placebo throughout the study and nine of whom received placebo during the first three days, caffeine during the subsequent seven days, and placebo during the final four days of the two-week study. Those who received caffeine were given 250 mg with meals three times daily. There were no untoward reactions in the course of the study, but one subject with unacceptably high blood pressures while receiving placebo had to be discharged from the study to resume antihypertensive therapy. Systolic blood pressure was immediately increased (9.2 +/- 3.4 mm Hg) within 15 minutes after the first dose of 250 mg of caffeine. On the first day of caffeine, systolic pressure was increased a mean of 7.3 +/- 4.0 mm Hg, but this was no longer significant after the initial day of caffeine administration. Diastolic pressure showed a trend toward increasing, but this never reached significance. The minor increases in plasma catecholamine levels and plasma renin activity were not significant on either a short- or long-term basis. After discontinuation of caffeine, no overshoot phenomena were observed. It is concluded that prolonged administration of caffeine is not associated with significant elevation in blood pressure, plasma catecholamine levels, or plasma renin activity in patients with borderline hypertension.

Amyloid tumor of the spleen.

An unusual case of amyloid tumor of the spleen that developed in a patient with malignant lymphoma is reported. A splenectomy performed for a persistent splenic lesion after an otherwise complete response to chemotherapy revealed the amyloid tumor. To our knowledge, amyloid tumor has not been previously described in the spleen.

The use and tolerability of fluoxetine in geropsychiatric inpatients.

BACKGROUND: The efficacy and tolerability of fluoxetine were examined in 31 patients admitted to a geropsychiatric inpatient unit who were initiated and maintained on a regimen of fluoxetine. METHOD: The Hamilton Rating Scale for Depression, the Brief Psychiatric Rating Scale, the Mini-Mental State Examination, and the Rating Scale for Side Effects were administered at admission and discharge, and scores were compared using paired t tests. Two patients were withdrawn from fluoxetine prior to discharge because of side effects; their data are not included in the analysis. RESULTS: We found significant improvement both in depressive symptoms and in general psychiatric symptoms and nonsignificant improvement in cognitive function. Fluoxetine was well-tolerated, and a significant decrease in the total scores of the Rating Scale for Side Effects was found. Subgroups of older patients (mean age = 75 years), less depressed patients, and demented patients were also examined. In all three groups, we found a statistically significant improvement in depressive symptoms, general psychiatric symptoms, and total side effects. CONCLUSION: Fluoxetine appears to be an effective and well-tolerated antidepressant in elderly inpatients of varying age, levels of depression, and psychiatric diagnoses.

Methylene blue: a reliable and practical marker for validating compliance on the DST.

Assurance of compliance (ingestion of dexamethasone) is crucial for interpreting plasma cortisol results on the DST. In this double-blind study of 13 subjects, methylene blue (MB) 50 mg was combined with dexamethasone 1 mg in single capsules, and the resulting blue-green urinary color after ingestion was found to reliably validate compliance in 100% of patients and controls. The addition of MB did not influence DST results (i.e., plasma cortisol, plasma dexamethasone). Adding MB to dexamethasone as a marker is a reliable and safe means of validating compliance on the DST and is considerably more practical than plasma dexamethasone level determinations.

Relationship of renal hemodynamic and functional changes following intravascular contrast to the renin-angiotensin system and renal prostacyclin in the dog.

Deterioration in renal function has been observed after the use of intravascular contrast media. In an attempt to identify factors responsible for this phenomenon, meglumine iothalamate (Conray 60), in a dosage range of 2.5-3.3 ml/kg, was injected as a bolus into the aorta of dogs. Serial measurements were made of parameters of renal function as well as of changes in aortic and renal venous levels of angiotensin II, renin activity, and 6-keto-PGF1 alpha, the stable metabolite of prostacyclin. The major findings were (1) an initial, brief increase followed by approximately a 20% sustained decrease in renal blood flow and creatinine clearance, (2) no significant changes in angiotensin II and renin levels, and (3) a significant decline in the renal secretory rate of 6-keto-PGF1 alpha. These observations suggest that the suppression of prostacyclin, rather than the activation of the renin-angiotensin system, may contribute to the renal function changes attending the use of intravascular contrast media.

The benefits of psychiatric hospitalization for older nursing home residents.

OBJECTIVE: To examine the demographic characteristics and treatment outcomes of nursing home residents admitted to a geropsychiatric inpatient unit. DESIGN: A retrospective cohort design based on an ongoing data base effort. SETTING: The geropsychiatric inpatient unit of the Houston Veterans Affairs Medical Center Hospital. PARTICIPANTS: All admissions to the unit from nursing homes during an 18-month period. MEASUREMENTS: Mini-Mental State Examination, Brief Psychiatric Rating Scale, Hamilton Rating Scale for Depression, Cohen-Mansfield Agitation Inventory, Rating Scale for Side Effects, and Global Assessment of Functioning were administered on admission and discharge. RESULTS: Paired t tests comparing change scores revealed significant decreases in general psychiatric symptoms (P < .001), depression (P < .001), and agitation (P < .001); significant improvement in global functioning (P < .001); with no significant changes in cognitive status (P = .485) or side effects (P = .120). When the patients were subgrouped according to reasons for admission, paired t tests revealed decreases in violence (CMAI Factor 1; P = .000), psychosis (BPRS thought disorder scale; P = .000 and hostility subscale; P < .008), and depression (HAM-D; P = .002). Four patients were discharged to less restrictive environments, all with chronic mental illnesses. CONCLUSION: Inpatient psychiatric hospitalization significantly benefits nursing home residents with and without dementia who are admitted for severe behavior problems.

Enhancing the financial performance of a health system laboratory network using an information system.

We describe the improvements created by successful implementation of a laboratory information system for a multi-institutional integrated delivery system, including an analysis of the financial results. Conditions at the outset of the project, methods of management and project design, selected aspects of services redesign and consolidation, integration of services among the sites and their effects on laboratory staff and productivity are illustrated. A method for and example of measuring the financial outcomes in the sense of quantifiable improvements in operating expenses and new revenue for a whole health system clinical laboratory computer system are discussed. In this health system, the measurable financial improvements facilitated by an information system were the ability to control operating expenses and to grow the hospital laboratory network through the development of an outreach program. With organizational commitment to process innovation and improvement, using team processes and customer-driven decision-making criteria, the financial performance of our consolidated laboratory network was enhanced substantially. A fully implemented laboratory information system is considered the major enabler of positive change when combined with a genuine commitment from all levels of staff and leadership. Over time, this system's financial return is several times that of the information system investment.

Contribution of psychosis and depression to behavioral disturbances in geropsychiatric inpatients with dementia.

BACKGROUND: Specific behavioral disturbances in dementia may be associated with underlying disorders such as the presence of psychosis and depression. The objective of this study was to examine the association of depression and psychosis with behavioral disturbances in geropsychiatric inpatients with dementia. METHODS: All admissions between October 1993 and May 1995 were reviewed to identify those patients admitted to the Houston Veterans Affairs Geropsychiatry Unit with a diagnosis of dementia; 208 patients were included in the study. Hierarchical regression models were constructed to explore the contribution of depressive and psychotic symptoms, and depression and psychosis diagnoses to Cohen-Mansfield Agitation Inventory (CMAI) scores. RESULTS: Both depression and psychotic symptoms were significantly and positively correlated with behavioral disturbances. Psychotic symptoms were associated with aggressive behavioral symptoms, and depressive symptoms were associated with constant requests for help, complaining, and negativism. Dementia severity accounted for significant variance in CMAI scores and was positively associated with behavioral disturbance; though disorder symptoms accounted for more behavioral disturbance variance than did depressive symptoms. CONCLUSIONS: Both depressive and psychotic symptoms were associated with overall behavioral disturbances in patients with dementia. Psychotic symptoms and depressive symptoms were associated with different types of behavioral disturbances. Our findings support the contention that underlying depression or psychosis may partially account for different behavioral disturbances and that not all behavioral disturbances should be globally labeled "agitation." Future studies should address symptom-specific treatment of behaviorally disturbed patients.