Retrospective observational study of patient outcomes with local wound infusion vs epidural analgesia after open hepato-pancreato-biliary surgery.

BACKGROUND: Epidural analgesia is conventionally used as the mainstay of analgesia in open abdominal surgery but has a small life-changing risk of complications (epidural abscesses or haematomas). Local wound-infusion could be a viable alternative and are associated with fewer adverse effects. METHODS: A retrospective observational analysis of individuals undergoing open hepato-pancreato-biliary surgery over 1 year was undertaken. Patients either received epidural analgesia (EP) or continuous wound infusion (WI) + IV patient controlled anaesthesisa (PCA) with an intraoperative spinal opiate. Outcomes analyzed included length of stay, commencement of oral diet and opioid use. RESULTS: Between Jan 2016- Dec 2016, 110 patients were analyzed (WI n=35, EP n=75). The median length of stay (days) was 8 in both the WI and EP group (p=0.846), the median time to commencing oral diet (days) was 3 in WI group and 2 in EP group (p=0.455). There was no significant difference in the amount of oromorph, codeine or tramadol (mg) between WI and EP groups (p=0.829, p=0.531, p=0.073, respectively). CONCLUSIONS: Continuous wound infusion + IV PCA provided adequate analgesia to patients undergoing open hepato-pancreato-biliary surgery. It was non-inferior to epidural analgesia with respect to hospital stay, commencement of oral diet and opioid use.

A Composite Measure of Gambling Exposure: Availability, Accessibility or Both?

Measures of availability and accessibility are often used separately or interchangeably to assess gambling exposure. This study examined the advantages of assessing gambling exposure using availability, accessibility, and a composite measure. Logistic and poisson regression analyses were used to determine the relative importance of these measures in predicting problem gambling using data from the 2008 and 2009 Social and Economic Impacts of Gambling in Alberta (SEIGA) surveys. The composite measure of gambling exposure predicted both the risk and severity of problem gambling better than the availability or accessibility measures alone. These results demonstrate that individual differences in problem gambling are better predicted by a composite measure of exposure.

The Relative and Interactive Effects of Actual and Perceived Gambling Exposure on Gambling Behaviour.

Actual and perceptual measures of gambling exposure are important predictors of problem gambling. This study used Zero-Inflated Poisson regression analyses to assess the relative and interactive effects of actual and perceived exposure on problem gambling risk and severity. Data from the 2008 and 2009 Social and Economic Impacts of Gambling in Alberta surveys indicated actual exposure was significantly associated with problem gambling risk while perceived exposure was significantly associated with problem gambling severity. These associations differ for gamblers from emerging and mature areas. Further, actual and perceived exposure had significant interaction effects on problem gambling severity but not on risk. Implications from these findings suggest that the prevalence of problem gambling could be reduced by restrictions on gambling opportunities.

"It Runs in Your Blood": Reflections from Treatment Seeking Gamblers on Their Family History of Gambling.

There are considerable gaps in our understanding of the familial transmission of gambling problems. This convergent mixed-methods study aimed to explore the: (1) sources of heterogeneity in the familial (paternal, maternal, and sibling) transmission of gambling problems; (2) degree to which family-of-origin characteristics are associated with family-of-origin problem gambling; and (3) beliefs of gamblers about the nature of the familial transmission of problem gambling. The sample consisted of 97 treatment-seeking gamblers in Australia. One-quarter (25.5%) of participants reported that at least one family member (16.5% father, 7.5% mother, 7.6% siblings) living with them when they were growing up had a gambling problem. Most participants reported that family members with a positive history of problem gambling were biological relatives, lived with them full-time, and experienced long-term difficulties with gambling. Participants with a family history of problem gambling were young (less than 12 years of age) at the onset of parental, but not sibling, problem gambling, were women, and reported difficulties with the same gambling activity as their family member. Participants raised in families with problem gambling were more likely to report parental separation (risk ratio [RR] = 2.32) and divorce (RR = 2.83), and extreme family financial hardship (RR = 1.80), as well as low levels of paternal authoritative parenting than participants raised in non-problem gambling families. Qualitatively, both social learning and genetics were perceived to play a central role in the familial transmission of gambling problems. These findings inform theories of the familial transmission of gambling problems and the design of targeted prevention and intervention strategies.

Rabies: a medical perspective.

Rabies is an acute neurological infection of humans and animals, caused by rabies virus and usually transmitted by animal bites. After an incubation period usually lasting weeks or longer, a variety of prodromal symptoms may occur. Encephalitic rabies (80% of cases) is associated with episodes of generalised arousal or hyperexcitability and hydrophobia, in which spasms involve the contraction of inspiratory muscles with swallowing. Paralytic rabies (in 20% of cases) is characterised by progressive lower motor neuron weakness. Laboratory investigations are important for confirming an ante mortem diagnosis of rabies. Cardiopulmonary and many other complications, including multiple organ failure, are common in aggressively managed rabies patients in critical care units. No effective therapy is available for rabies and survivors are uncommon. In contrast, preventative measures for rabies are highly effective after recognised exposures.

La rage est une maladie neurologique aiguë affectant les personnes et les animaux infectés par le virus de la rage, lequel est généralement transmis par la morsure d'un animal. Des signes précurseurs peuvent apparaître après une période d'incubation de quelques semaines voire plus. La rage encéphalique (qui représente 80 % des cas) est associée à des épisodes d'agitation ou d'hyperexcitabilité et d'hydrophobie durant lesquels surviennent des contractions spasmodiques des muscles pharyngés lors de la déglutition. La rage paralytique (20 % des cas) se caractérise par une dégénérescence progressive des neurones moteurs inférieurs. Des analyses de laboratoire sont nécessaires pour obtenir confirmation ante-mortem d'un diagnostic de rage. Des complications notamment cardiopulmonaires ainsi que des défaillances de plusieurs organes sont fréquentes chez les patients atteints soumis à des traitements très lourds dans les services de réanimation. Il n'existe pas de traitement curatif efficace et les survivants sont rares. En revanche, les mesures préventives suite à une exposition avérée sont extrêmement efficaces.

La rabia es una infección neurológica aguda que afecta a personas y animales, causada por el virus de la rabia y transmitida generalmente por la mordedura de un animal. Tras un periodo de incubación que suele durar semanas, o incluso más tiempo, pueden aparecer diversos síntomas prodrómicos. La rabia encefálica (un 80% de los casos) se acompaña de episodios de nerviosismo generalizado hiperexcitabilidad e hidrofobia, con espasmos que entrañan la contracción de los músculos inspiratorios con la deglución. La rabia paralítica (un 20% de los casos) se caracteriza por un debilitamiento progresivo de la neurona motora inferior. Los análisis de laboratorio son importantes para confirmar un diagnóstico ante mortem de rabia. Es frecuente que los pacientes tratados con terapias agresivas en las unidades de cuidados intensivos sufran complicaciones cardiopulmonares, entre otras muchas que pueden ir hasta la insuficiencia multiorgánica. No hay un tratamiento eficaz contra la rabia y son contadas las personas que sobreviven. En cambio, las medidas de profilaxis tras una exposición resultan muy eficaces.

Improved Outcomes Following a Single Session Web-Based Intervention for Problem Gambling.

Research suggests online interventions can have instant impact, however this is yet to be tested with help-seeking adults and in particular those with problem gambling. This study seeks to determine the immediate impact of a single session web-based intervention for problem gambling, and to examine whether sessions evaluated positively by clients are associated with greater improvement. The current study involved 229 participants classified as problem gamblers who agreed to participate after accessing Gambling Help Online between November 2010 and February 2012. Almost half were aged under 35 years of age (45 %), male (57 %) as well as first time treatment seekers (62 %). Participants completed measures of readiness to change and distress both prior to and post-counselling. Following the provision of a single-session of counselling, participants completed ratings of the character of the session (i.e., degree of depth and smoothness) post-counselling. A significant increase in confidence to resist and urge to gamble and a significant decrease in distress (moderate effect size; d = .56 and .63 respectively) was observed after receiving online counselling. A hierarchical regression indicated the character of the session was a significant predictor of change in confidence, however only the sub-scale smoothness was a significant predictor of change in distress. This was the case even after controlling for pre-session distress, session word count and client characteristics (gender, age, preferred gambling activity, preferred mode of gambling, gambling severity, and preferred mode of help-seeking). These findings suggest that single session web-based counselling for problem gambling can have immediate benefits, although further research is required to examine the impact on longer-term outcomes.

Problem Gambling Family Impacts: Development of the Problem Gambling Family Impact Scale.

Although family members of problem gamblers frequently present to treatment services, problem gambling family impacts are under-researched. The most commonly endorsed items on a new measure of gambling-related family impacts [Problem Gambling Family Impact Measure (PG-FIM: Problem Gambler version)] by 212 treatment-seeking problem gamblers included trust (62.5 %), anger (61.8 %), depression or sadness (58.7 %), anxiety (57.7 %), distress due to gambling-related absences (56.1 %), reduced quality time (52.4 %), and communication breakdowns (52.4 %). The PG-FIM (Problem Gambler version) was comprised of three factors: (1) financial impacts, (2) increased responsibility impacts, and (3) psychosocial impacts with good psychometric properties. Younger, more impulsive, non-electronic gaming machine (EGM) gamblers who had more severe gambling problems reported more financial impacts; non-EGM gamblers with poorer general health reported more increased responsibility impacts; and more impulsive non-EGM gamblers with more psychological distress and higher gambling severity reported more psychosocial impacts. The findings have implications for the development of interventions for the family members of problem gamblers.

Gambling Motives: Application of the Reasons for Gambling Questionnaire in an Australian Population Survey.

The Reasons for Gambling Questionnaire (RGQ) consist of 15 items forming five factors: enhancement, social, money, recreation and coping. The RGQ was developed for use in the 2010 British Gambling Prevalence Survey (BGPS) and has now been employed in the second Social and Economic Impact Study (SEIS) of Gambling in Tasmania study conducted in 2011 in Australia. Given differences between Britain and Australia in terms of socio-demographic profiles, gambling cultures and attitudes, gambling access and availability, gambling regulation, and rates and patterns of gambling participation, the aims of this study were to analyse the RGQ data from the SEIS to: (1) determine the most commonly endorsed gambling motives in an Australian jurisdiction, (2) explore the factor structure of the RGQ in an Australian sample, and (3) explore how motives for gambling vary among different Australian population sub-groups. A representative sample of the Tasmanian population who had gambled in the previous 12 months (n = 2,796) were administered the RGQ via computer-assisted telephone interviewing. The five most commonly endorsed reasons for gambling were for fun (62%), followed by the chance of winning big money (52%), it being something to do with friends and family (48%), to be sociable (40%), and excitement (38%). A principal component analysis revealed a five-factor structure that is slightly different from that derived in the BGPS: money, regulate internal state, positive feelings, social, and challenge reasons. Finally, gambling motives varied according to socio-demographic factors, number of gambling activities, problem gambling severity, and participation on different gambling activities. Although some of these findings are consistent with those from the BGPS, there are also some slight differences, suggesting that there may be regional-specific variations in gambling motives.

Negative and positive mental health characteristics of affected family members: Findings from a cross-sectional Australian general population gambling study.

Despite the impact of problem gambling on affected family members (AFMs), there are limited large-scale population level studies identifying the negative mental health (NMH) and positive mental health (PMH) characteristics of AFMs. Furthermore, no study has explored whether PMH characteristics are protective in the relationships between AFM status and NMH characteristics. This study involved secondary data analysis from the Third Social and Economic Impact Study of Gambling in Tasmania. Using a subsample of 1,869 adults (48.30 % male; meanage = 48.48; 4.67 % AFMs), this study aimed to explore whether: (1) AFM status is associated with NMH (depression, anxiety, panic, post-traumatic stress disorder, social anxiety, binge drinking, tobacco use, and drug use symptoms) and PMH (quality of life [QOL], personal growth/autonomy, interpersonal/social skills, coping skills) characteristics after separately controlling for sociodemographic, problem gambling severity, and other NMH characteristics; (2) PMH characteristics moderate (buffer) the relationships between AFM status and NMH characteristics; and (3) gender influences these relationships. AFM status, defined as exposure to family member gambling problems, significantly positively predicted NMH characteristics (depression, anxiety, panic, PTSD, and tobacco use symptoms) and negatively predicted QOL (physical, social) and planning coping. The strength of these relationships generally attenuated after controlling for various covariates. Gender did not moderate these relationships. Religious coping exacerbated the relationship between AFM status and panic disorder symptoms. These findings can inform the development of intervention initiatives for family members exposed to gambling problems. Future population-representative research is required using a range of affected other types, longitudinal study designs, and more comprehensive measures.

Up-regulation of chemokine gene transcripts and T-cell infiltration into the central nervous system and dorsal root ganglia are characteristics of experimental European bat lyssavirus type 2 infection of mice.

European bat lyssaviruses (EBLV) types 1 and 2 are closely related to classical rabies virus (RABV), and are capable of causing rabies in terrestrial mammals, including humans. The authors have investigated the murine host innate immune response in the brain, salivary gland, spinal cord, and blood, following peripheral inoculation with EBLV-2. In the brain, increases in Toll-like receptor-3 (TLR-3) transcript preceded overt disease, with a range of inflammatory gene transcripts increasing during the clinical stage of infection. This included transcripts for interleukin-6 (IL-6), interferon-gamma (IFN-gamma), and CXC chemokine ligand 10 (CXCL10). In the salivary gland, there was a small but significant increase of CXCL10 gene transcript and a limited increase in 2'-5' oligoadenylate synthetase (2'-5' OAS1) transcript. In the blood, there was an increase in levels of IFN-gamma and virus-neutralizing antibodies (VNAs) were detected prior to the appearance of clinical signs. These changes were associated with severe lymphocyte infiltration observed within the spinal cord and dorsal root ganglia (DRG), which was dominated by T lymphocytes and associated with widespread inflammatory changes. The authors speculate that the increase of inflammatory cytokines and chemokines in response to EBLV-2 infection leads to a dramatic increase in T-cell infiltration and provides evidence for a robust immune response to lyssavirus infection that may not commonly occur in RABV infection.

Human rabies therapy: lessons learned from experimental studies in mouse models.

Ketamine was one of the therapeutic agents used as a therapy for a human rabies survivor who did not receive rabies vaccine. Ketamine therapy is re-examined here in infected mouse primary neuron cultures and in adult ICR mice using the CVS strain with both intracerebral and peripheral routes of inoculation with ketamine vs. vehicle given intraperitoneally. No significant beneficial therapeutic effects of ketamine in the cultures or mouse model were observed. This team does not recommend further widespread clinical use of ketamine on human rabies patients until further experimental work demonstrates therapeutic efficacy. Because of the potential neuroprotective and anti-apoptotic properties of minocycline, minocycline therapy was assessed in infected primary neuron cultures and in neonatal ICR mice infected by peripheral inoculation with a highly attenuated rabies virus strain. No beneficial effect of minocycline was observed in the primary neuron cultures. In the mouse model, minocycline therapy aggravated the clinical neurological disease and resulted in higher mortality. An anti-apoptotic effect of minocycline was noted in the brains of infected mice, which may have very mildly increased viral spread. An anti-inflammatory effect was also noted in the brain using a CD3 T cell marker. These effects likely aggravated the disease. This team recommends that empirical therapy with minocycline be avoided in the management of rabies and viral encephalitis in humans until more information becomes available.

The intergenerational transmission of problem gambling: The mediating role of offspring gambling expectancies and motives.

INTRODUCTION: The risk for developing a gambling problem is greater among offspring who have a problem gambling parent, yet little research has directly examined the mechanisms by which this transmission of problem gambling occurs. For this reason, the present study sought to examine the degree to which children's expectancies and motives relating to gambling explain, at least in part, the intergenerational transmission of problem gambling. METHODS: Participants (N=524; 56.5% male) were recruited from educational institutions, and retrospectively reported on parental problem gambling. Problem gambling was measured using the Problem Gambling Severity Index and a range of positive and negative expectancies and gambling motives were explored as potential mediators of the relationship between parent-and-participant problem gambling. RESULTS: The relationship between parent-and-participant problem gambling was significant, and remained so after controlling for sociodemographic factors and administration method. Significant mediators of this relationship included self-enhancement expectancies (feeling in control), money expectancies (financial gain), over-involvement (preoccupation with gambling) and emotional impact expectancies (guilt, shame, and loss), as well as enhancement motives (gambling to increase positive feelings) and coping motives (gambling to reduce or avoid negative emotions). All mediators remained significant when entered into the same model. CONCLUSIONS: The findings highlight that gambling expectancies and motives present unique pathways to the development of problem gambling in the offspring of problem gambling parents, and suggest that gambling cognitions may be potential candidates for targeted interventions for the offspring of problem gamblers.

Lung growth and airway function after lobectomy in infancy for congenital lobar emphysema.

To characterize the outcome of lobectomy in infancy and the low expiratory flows which persist after lobectomy for congenital lobar emphysema, 15 subjects with this history were studied at age 8-30 yr. Total lung capacity was normal in all, but higher values (P < 0.05) were observed in nine subjects with upper lobectomy than in five subjects with right middle lobectomy. Ratio of residual volume to total lung capacity was correlated (P < 0.05) with the amount of lung missing as estimated from normal relative weights of the respective lobes. Xe(133) radiospirometry in eight subjects showed that the operated and unoperated sides had nearly equal volumes at total lung capacity, but that the operated side was larger than the unoperated side at residual volume. Perfusion was equally distributed between the two sides. Similar findings were detected radiographically in four other subjects. Forced expiratory volume in 1 s and maximal midexpiratory flow rate averaged 72 and 45% of predicted, respectively. Low values of specific airway conductance and normal density dependence of maximal flows in 12 subjects suggested that obstruction was not limited to peripheral airways. Pathologic observations at the time of surgery and morphometry of the resected lobes were not correlated with any test of pulmonary function. These data show that lung volume can be completely recovered after lobectomy for congenital lobar emphysema in infancy. The volume increase occurs on the operated side, and probably represents tissue growth rather than simple distension. The response to resection is influenced by the particular lobe resected and may be associated with decreased lung recoil near residual volume. Low expiratory flows in these subjects could be explained by several mechanisms, among which a disproportion between airway and parenchymal growth in infancy (dysanaptic growth) is most compatible with our data.

Social and emotional wellbeing assessment instruments for use with Indigenous Australians: A critical review.

RATIONALE: There is growing recognition that in addition to universally recognised domains and indicators of wellbeing (such as population health and life expectancy), additional frameworks are required to fully explain and measure Indigenous wellbeing. In particular, Indigenous Australian wellbeing is largely determined by colonisation, historical trauma, grief, loss, and ongoing social marginalisation. Dominant mainstream indicators of wellbeing based on the biomedical model may therefore be inadequate and not entirely relevant in the Indigenous context. It is possible that "standard" wellbeing instruments fail to adequately assess indicators of health and wellbeing within societies that have a more holistic view of health. OBJECTIVE: The aim of this critical review was to identify, document, and evaluate the use of social and emotional wellbeing measures within the Australian Indigenous community. METHOD: The instruments were systematically described regarding their intrinsic properties (e.g., generic v. disease-specific, domains assessed, extent of cross-cultural adaptation and psychometric characteristics) and their purpose of utilisation in studies (e.g., study setting, intervention, clinical purpose or survey). We included 33 studies, in which 22 distinct instruments were used. RESULTS: Three major categories of social and emotional wellbeing instruments were identified: unmodified standard instruments (10), cross-culturally adapted standard instruments (6), and Indigenous developed measures (6). Recommendations are made for researchers and practitioners who assess social and emotional wellbeing in Indigenous Australians, which may also be applicable to other minority groups where a more holistic framework of wellbeing is applied. CONCLUSION: It is advised that standard instruments only be used if they have been subject to a formal cross-cultural adaptation process, and Indigenous developed measures continue to be developed, refined, and validated within a diverse range of research and clinical settings.

National estimates of Australian gambling prevalence: f indings from a dual-frame omnibus survey.

BACKGROUND, AIMS AND DESIGN: The increase in mobile telephone-only households may be a source of bias for traditional landline gambling prevalence surveys. Aims were to: (1) identify Australian gambling participation and problem gambling prevalence using a dual-frame (50% landline and 50% mobile telephone) computer-assisted telephone interviewing methodology; (2) explore the predictors of sample frame and telephone status; and (3) explore the degree to which sample frame and telephone status moderate the relationships between respondent characteristics and problem gambling. SETTING AND PARTICIPANTS: A total of 2000 adult respondents residing in Australia were interviewed from March to April 2013. MEASUREMENTS: Participation in multiple gambling activities and Problem Gambling Severity Index (PGSI). FINDINGS: Estimates were: gambling participation [63.9%, 95% confidence interval (CI) = 61.4-66.3], problem gambling (0.4%, 95% CI = 0.2-0.8), moderate-risk gambling (1.9%, 95% CI = 1.3-2.6) and low-risk gambling (3.0%, 95% CI = 2.2-4.0). Relative to the landline frame, the mobile frame was more likely to gamble on horse/greyhound races [odds ratio (OR) = 1.4], casino table games (OR = 5.0), sporting events (OR = 2.2), private games (OR = 1.9) and the internet (OR = 6.5); less likely to gamble on lotteries (OR = 0.6); and more likely to gamble on five or more activities (OR = 2.4), display problem gambling (OR = 6.4) and endorse PGSI items (OR = 2.4-6.1). Only casino table gambling (OR = 2.9) and internet gambling (OR = 3.5) independently predicted mobile frame membership. Telephone status (landline frame versus mobile dual users and mobile-only users) displayed similar findings. Finally, sample frame and/or telephone status moderated the relationship between gender, relationship status, health and problem gambling (OR = 2.9-7.6). CONCLUSION: Given expected future increases in the mobile telephone-only population, best practice in population gambling research should use dual frame sampling methodologies (at least 50% landline and 50% mobile telephone) for telephone interviewing.

The intergenerational transmission of problem gambling: The mediating role of parental psychopathology.

The present study investigated the intergenerational transmission of problem gambling and the potential mediating role of parental psychopathology (problem drinking, drug use problems, and mental health issues). The study comprised 3953 participants (1938 males, 2015 females) recruited from a large-scale Australian community telephone survey of adults retrospectively reporting on parental problem gambling and psychopathology during their childhood. Overall, 4.0% [95%CI 3.0, 5.0] (n=157) of participants reported paternal problem gambling and 1.7% [95%CI 1.0, 2.0] (n=68) reported maternal problem gambling. Compared to their peers, participants reporting paternal problem gambling were 5.1 times more likely to be moderate risk gamblers and 10.7 times more likely to be problem gamblers. Participants reporting maternal problem gambling were 1.7 times more likely to be moderate risk gamblers and 10.6 times more likely to be problem gamblers. The results revealed that the relationships between paternal-and-participant and maternal-and-participant problem gambling were significant, but that only the relationship between paternal-and-participant problem gambling remained statistically significant after controlling for maternal problem gambling and sociodemographic factors. Paternal problem drinking and maternal drug use problems partially mediated the relationship between paternal-and-participant problem gambling, and fully mediated the relationship between maternal-and-participant problem gambling. In contrast, parental mental health issues failed to significantly mediate the transmission of gambling problems by either parent. When parental problem gambling was the mediator, there was full mediation of the effect between parental psychopathology and offspring problem gambling for fathers but not mothers. Overall, the study highlights the vulnerability of children from problem gambling households and suggests that it would be of value to target prevention and intervention efforts towards this cohort.

The Prevalence of Comorbid Personality Disorders in Treatment-Seeking Problem Gamblers: A Systematic Review and Meta-Analysis.

The aim of this study was to systematically review and meta-analyze the prevalence of comorbid personality disorders among treatment-seeking problem gamblers. Almost one half (47.9%) of problem gamblers displayed comorbid personality disorders. They were most likely to display Cluster B disorders (17.6%), with smaller proportions reporting Cluster C disorders (12.6%) and Cluster A disorders (6.1%). The most prevalent personality disorders were narcissistic (16.6%), antisocial (14.0%), avoidant (13.4%), obsessive-compulsive (13.4%), and borderline (13.1%) personality disorders. Sensitivity analyses suggested that these prevalence estimates were robust to the inclusion of clinical trials and self-selected samples. Although there was significant variability in reported rates, subgroup analyses revealed no significant differences in estimates of antisocial personality disorder according to problem gambling severity, measure of comorbidity employed, and study jurisdiction. The findings highlight the need for gambling treatment services to conduct routine screening and assessment of co-occurring personality disorders and to provide treatment approaches that adequately address these comorbid conditions.

Intracellular dynamics of sst5 receptors in transfected COS-7 cells: maintenance of cell surface receptors during ligand-induced endocytosis.

Internalization of G protein-coupled receptors is crucial for resensitization of phosphorylation-desensitized receptors, but also for their long term desensitization through sequestration. To elucidate the mechanisms regulating cell surface availability of the somatostatin (SRIF) receptor subtype sst5, we characterized its internalization properties in transfected COS-7 cells using biochemical, confocal microscopic, and electron microscopic techniques. Our results demonstrated rapid and efficient sequestration of specifically bound [125I]Tyr0-D-Trp8-SRIF (up to 45% of bound radioactivity). Combined immunocytochemical detection of sst5 and visualization of a fluorescent SRIF analog by confocal microscopy revealed that whereas the internalized ligand progressively clustered toward the cell center with time, immunoreactive receptors remained predominantly associated with the plasma membrane. The preservation of cell surface receptors was confirmed by binding experiments on whole cells revealing a lack of saturability of [125I]Tyr0-D-Trp8-SRIF binding at 37 C. Binding was rendered saturable by the drug monensin, showing that receptor recycling played a key role in the preservation of cell surface receptors. Electron microscopy demonstrated that in addition to receptor recycling, internalization of receptor-ligand complexes triggered a massive recruitment of sst5 receptor molecules from intracellular stores to the membrane. This combination of recycling and recruitment of spare receptors may protect sst5 from long term down-regulation through sequestration and, therefore, facilitate extended SRIF signaling.