Cadmium as an uncoupler of respiration in Ulva lactuca

The effect of cadmium on the respiration of Ulva lactuca was examined using an oxygen electrode. Discs of U. lactuca thallus in filtered seawater were either incubated in the dark for 24 h or treated with 20 μM 3(3,4-dichlorophenyl) 1,1-dimethylurea to inhibit photosystem II dependent noncyclic electron transfer. In both cases, the addition of cadmium, as sulphate, increased respiration, with maximum stimulation occurring at approximately 15 mM; above this concentration respiration declined and at >21 mM inhibitory effects were significant. Dinitrophenol (DNP, 50 μM) and carbonyl cyanide m-chlorophenylhydrazone (CCCP, 10 μM) also uncoupled respiration of U. lactuca, and when these compounds were used in conjunction with Cd the effects were found to be additive. Oligomycin (12.5 μ mL^?1), which inhibits the mitochondrial ATPase, inhibited U. lactuca respiration but subsequent Cd addition (to 6 mM) resulted in a 2.5 × increase in respiration over control values. DNP had a similar effect when used with oligomycin. DNP and CCCP had a negligible effect on the respiration of KCN-treated discs but the addition of Cd restored respiration to control values, probably because of the formation of insoluble Cd(CN)₂. These results demonstrate that Cd can act as a respiratory uncoupler in U. lactuca.     

A longitudinal study of mental health consumer/survivor initiatives: Part 3—A qualitative study of impacts of participation on new members

This article examines the outcomes of participation in mental health Consumer/Survivor Initiatives (CSIs) and identifies helpful qualities of CSIs through a longitudinal, qualitative study that involved in‐depth interviews of people who experienced severe mental health challenges in Ontario, Canada. We used a nonequivalent control group design in which we compared active participants in CSIs ( n = 15) with nonactive participants ( n = 12) at baseline and at 9‐ and 18‐month follow‐up intervals. Compared with non‐CSI participants, CSI participants reported more stable mental health, enhanced social support, sustained work, stable income, and participation in education and training at 9‐ and 18‐month interviews. The helpful qualities of CSIs that participants reported were (1) safe environments that provide a positive, welcoming place to go; (2) social arenas that provide opportunities to meet and talk with peers; (3) an alternative worldview that provides opportunities for members to participate and contribute; and (4) effective facilitators of community integration that provide opportunities to connect members to the community at large. The findings are discussed in terms of previous research in self‐help and consumer‐run organizations in mental health. © 2006 Wiley Periodicals, Inc.     

13-cis-retinoic acid (NSC 122758) in the treatment of children with metastatic neuroblastoma unresponsive to conventional chemotherapy: Report from the childrens cancer study group

The Childrens Cancer Study Group evaluated daily oral 13-cis-retinoic acid to determine its therapeutic efficacy in 28 children with advanced neuroblastoma refractory to conventional therapy. Cheilitis and fissured lips were the most common side effects; however, fewer than 50% of the patients experienced any toxicity. Two of twenty-two evaluable children demonstrated positive response to therapy. In one case, a child received the drug for 11 months. Seventeen patients demonstrated progressive disease within 28 days of the start of treatment. Three other patients with stable disease, or removed from study at day 28, were considered nonresponsive. Our data demonstrate that, when given as a single daily oral dose of 100 mg/m², 13-cis-retinoic acid does not have significant activity in children with advanced neuroblastoma. © 1992 Wiley-Liss, Inc.     

Cross-neutralisation of Australian brown and tiger snake venoms with commercial antivenoms: Cross-reactivity or antivenom mixtures?

Recently it has been suggested that the Australian snake antivenoms made by CSL Ltd. are in fact not truly monovalent and may contain antibodies to other snake venoms because the horses are injected with multiple snake venoms. It is unclear to what extent various monovalent antivenoms can neutralise the effect of other venoms, whether this is due to a mixture of antibodies or true cross-reactivity, and whether this has any clinical significance. We aimed to study the immunological and functional properties of brown snake (Pseudonaja spp.) antivenom (BSAV) and tiger snake (Notechis spp.) antivenom (TSAV) against their respective venoms using enzyme immunoassays (EIA) and in vitro clotting studies. There was significant overlap between the two antivenoms with both TSAV and BSAV being detected by EIA on brown snake venom (BSV)-coated and tiger snake venom (TSV)-coated wells, respectively. In a competition EIA, increasing amounts of immunoaffinity-purified hen anti-brown antibodies (IgYp) mixed with TSAV reduced TSAV measured on TSV-coated wells. Both BSAV and TSAV prevented the clotting activity of both venoms. IgYp also prevented the clotting activity of TSV, suggesting true cross-reactivity. The cross-reactivity of TSAV and BSAV with BSV and TSV, respectively, was likely due to each being a mixture of anti-brown and anti-tiger antibodies, but there was partial cross-reactivity demonstrated by the effect of IgYp. Single-polyvalent antivenom for brown snake and tiger snake may be feasible in the future.     

The pharmacology of recombinant GABAA receptors containing bovine alpha 1, beta 1, gamma 2L sub-units stably transfected into mouse fibroblast L-cells.

1. Responses to gamma-aminobutyric acid (GABA) were evoked in mouse fibroblast L-cells stably transfected with bovine, alpha 1, beta 1, gamma 2L sub-units of the GABAA receptor. Expression was stimulated via a steroid-inducible promoter system. 2. In near symmetrical intracellular and extracellular chloride concentrations, GABA evoked inward currents at negative holding potentials that reversed at +5 mV and displayed slight outward rectification. Concentration-response curves were fitted well by the logistic equation. GABA had a pEC50 = 5.1 +/- 0.1 and the curves had a slope of 1.9 +/- 0.1. 3. Responses to GABA were antagonized by bicuculline, picrotoxin and penicillin. The action of bicuculline was competitive (pA2 = 6.4) whilst the block by picrotoxin was uncompetitive and strongly agonist-dependent. 4. Benzodiazepine receptor agonists potentiated responses to 3 microM GABA. The rank order of potency was FG 8205 > flunitrazepam > zolpidem > C1218872. FG 8205 and C1218872 produced markedly lower maximal potentiations with efficacies 0.4 and 0.6 x that of flunitrazepam, respectively. The potencies of zolpidem and C1218872 observed are in agreement with the BZ1 type pharmacology of this sub-unit combination. The potentiation of GABA by flunitrazepam was antagonized by flumazenil with a Ki of 3.8 nM. 5. GABA responses were potentiated in the presence of pentobarbitone and alphaxalone. The response was also noticeably broadened by these compounds due to a decrease in the response decay rate. Concentrations of pentobarbitone of 100 microM and above evoked an inward current in the absence of GABA. Alphaxalone up to 10 microM did not evoke a direct response.(ABSTRACT TRUNCATED AT 250 WORDS)     

Virtual real-time digital processing of hemodynamic data

At present, the majority of cardiac catheterization laboratories acquire and store hemo-dynamic data in analog form. To examine the possibility of performing complex analysis of digital data during the catheterization procedure, we examined whether virtual realtime digital (fast Fourier) analysis improves the accuracy of clinical data. We compared digital filtering of fluid manometry during right heart catheterization with 10-Hz and 250-Hz analog filters. Using the simultaneously acquired micromanometry as the “gold standard,” we found that analog filtering is associated with a greater error and time delay than digital filtering. This study demonstrates that digital hemodynamic data analysis performed during cardiac catheterization can improve the quality of data obtained during right heart catheterization, with the results available within seconds. More extensive use of computers in the cardiac catheterization laboratory may be useful for both clinical and research purposes. © 1992 Wiley-Liss, Inc.     

Hip fractures: a future epidemic?

Recent studies from the United Kingdom and Sweden have demonstrated a dramatic rise in the number of people with hip fractures. It is our hypothesis that New Zealand is experiencing a similar rise in the number of hip fractures. The number of elderly people (over age 65 years) admitted to public hospitals in New Zealand over a 38-year period was reviewed. In people over age 75 years, we observed a disproportionate increase in the number of fractures compared with the increase in population. The highest risk group was women over age 85 years. Because of the differing age-specific fracture rates, the proportion of females over age 85 increased from 17% in 1950 to 40% by 1987. Through weighted regression analysis of fracture rate and population predictions, the projected number of fractures in the year 2001 and 2011 was predicted. By 2011 the number of people sustaining hip fractures will more than double. The proportion of the very elderly (85+) will increase from 40 to 65%.     

Investigation of focal hepatic lesions: Is tomographic red blood cell imaging useful?

Noninvasive diagnosis of cavernous hemangioma of the liver is an important step in the investigation of patients with focal hepatic lesions since biopsy may result in life-threatening hemorrhage. To determine the diagnostic accuracy of 99m-technetium red blood cell (^99mTc-RBC) imaging with tomography, 50 patients with various types of focal liver lesions were studied. Thirty-two patients had 45 hemangiomas and 7 other benign lesions while 18 patients had either primary (n=8) or secondary (n=10) hepatic malignancies. Tomographic imaging identified 12 more hemangiomas than planar imaging, improving sensitivity from 53% to 80%, and was found most useful for detection of smaller lesions (mean size, 2.1 cm). Specificity for hemangiomas was 100% with all lesions greater than 1.9 cm showing the characteristic scintigraphic pattern of blood-pooling on delayed images. There was excellent agreement between 2 independent observers concerning interpretation of tomographic images (89% for the hemangioma group and 100% for other patients). Therefore^99mTc-RBC scintigraphy with tomography is an accurate diagnostic technique in the investigation of cavernous hemangiomas. Its major value resides in its ability to distinguish hemangiomas from other types of hepatic pathology.

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Resumen El diagnóstico no invasivo del hemangioma cavernoso del hígado es un paso de importancia en el proceso de investigación de pacientes con lesiones hepáticas focales, puesto que la biopsia puede resultar en hemorragia de consecuencias potencialmente fatales. Con el objeto de determinar la certeza diagnóstica de la tomografía con glóbulos rojos marcados con tecnecio 99m, se estudiaron 50 pacientes con varios tipos de lesiones hepáticas focales. Treinta y dos pacientes presentaron 45 hemangiomas y 7 lesiones benignas, en tanto que 18 pacientes presentaron neoplasias malignas primarias (n=8) o secundarias (n=10). Las imágenes tomográficas obtenidas por este método lograron identificar 12 hemangiomas más, en comparación con imágenes convencionales, aumentando la sensibilidad de 53% a 80%, y demostró ser de máxima utilidad para la detección de las lesiones más peque¯nas (tamaño promedio, 2.1 cm). La especificidad para los hemangiomas fue 100%, con todas las lesiones mayores de 1.9 cm exhibiendo el patrón centelleográfico característico de estancamiento sanguíneo en las imágenes tardías. Se encontró excelente correlación entre 2 observadores independientes en la interpretación de las imágenes tomográficas (89% para el grupo de pacientes con hemangiomas y 100% para el resto de los pacientes). En consecuencia, la escintigrafía con glóbulos rojos marcados con^99mTc aparece como una técnica certera en el diagnóstico de los hemangiomas cavernosos. Su mayor valor reside en su habilidad para diferenciar los hemangiomas de otra clase de patología.

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Résumé Le diagnostic non invasif d'hémangiome caverneux du foie est une étape importante dans l'investigation des patients ayant des lésions hépatiques focales, puisque la biopsie risque de se résoudre par une hémorrhagie menaçant le pronostic vital. Pour définir la précision diagnostique de la tomoscintigraphie après marquage des hématies au technetium 99m (^99mTc), on a étudié 50 patients ayant des types différents de lésions focales du foie. Trente-deux patients avaient 45 hémangiomes et 7 lésions bénignes tandis que 18 patients avaient des tumeurs hépatiques malignes soit primaires (n=8) soit secondaires (n=10). L'imagerie tomographique a identifié 12 hémangiomes de plus que l'imagerie planaire, améliorant la sensibilité de 53% à 80% et s'est avérée très utile pour détecter les lésions plus petites (taille moyenne, 2.1 cm). La spécificité pour les hémangiomes était de 100% pour toutes les lésions dépassant 1.9 cm montrant les caractères scintigraphiques typiques d'accumulation de sang sur les images retardées. Il y a eu concordance totale entre 2 observateurs indépendents sur l'interprétation des images tomographiques (89% pour le groupe des hémangiomes et 100% pour les autres patients). Voilà pourquoi la scintigraphie^99mTc avec tomographie est une technique de diagnostic précis dans l'investigation des hémangiomes caverneux. Sa valeur essentielle est sa capacité de distinguer les hémangiomes des autres types de pathologie hépatique.

     

Psychiatric morbidity in policemen and the effect of brief psychotherapeutic intervention — a pilot study

The level of psychiatric morbidity and perceived sources of stress among police officers were investigated using the General Health Questionnaire (GHQ) and a stress situation questionnaire, which were sent to 171 officers. Half of the responders were invited to attend group counselling sessions weekly for 12 weeks. Outcome measures studied were a second GHQ completed at the end of the treatment period and the amounts of sick leave taken in the 12-week period before, during and after the treatment period. The results were that 61 people returned the first GHQ of whom 59 were male and of whom 14 were classed as ‘cases’. Of the 31 assigned to the treatment group, 22 attended at least one session. Responses to the stress situation questionnaire and the content of counselling sessions tended to confirm the impression that internal aspects of the organization were viewed as prime sources of stress and dissatisfaction. There were no significant changes in GHQ score within or between groups, nor were there significant differences in the amount of sick leave taken. Nevertheless the sessions appeared to be valued and we conclude that this sort of intervention is at least feasible. We recommend that similar studies measure psychiatric morbidity during treatment and at follow-up, rather than immediately after finishing, when reactions to this termination are prominent.