Clinical Evaluation of the Cook Advance Enforcer 35 Focal-Force PTA Balloon Catheter for Treatment of Hemodialysis Fistula Stenoses: A Feasibility Study

Purpose

A prospective, single-center, single-arm feasibility study evaluated procedural and short-term performance of the Advance Enforcer 35 focal-force percutaneous transluminal angioplasty (PTA) balloon catheter in treating stenoses of mature native arteriovenous (AV) hemodialysis access circuits.

Simulated Transfer of Liquids and Powders from Hands and Clothing to the Mouth

A series of laboratory experiments was carried out to assess transfer of liquids (vinegar) and powders (calcium acetate and magnesium carbonate) from hands, arms, gloves, respirators, clothing, and pens to the oral cavity or the perioral area (the area surrounding the mouth). Experiments were carried out with four volunteers. The donor area (the hands, arms, gloves, and so on) was loaded with a known mass of the test substance and was then brought into contact the receiver area (the oral cavity or the perioral area). The percentage of the substance on the donor that transferred to the receiver (the transfer efficiency or TE) was assessed using saliva samples and gauze wipes of the perioral area. Magnesium carbonate was measured on gauze and in saliva using inductively coupled plasma/atomic emission spectrometry. Calcium acetate and vinegar were measured using ion chromatography/electrochemical detection. Average transfer efficiencies were calculated for each substance and transfer scenario; these were compared using ANOVA and Kruskal-Wallis tests. Overall, direct transfer from the hands to the oral cavity was significantly higher (mean TE = 51.6) than indirect transfer from the hands to the oral cavity via the perioral area by licking the lips (mean TE = 11.5). The results suggested higher TEs for liquids than for solids and that hand-to-mouth TEs may increase with water solubility. Transfer from bare arms to the perioral area was higher than from arms covered by cotton sleeves for both liquids and powders. Although TE data are often required by models estimating exposure by inadvertent ingestion, relatively few published data are available. This study has provided evidence of some factors that may influence transfer of chemicals from hands or objects to the mouth (physical form, use of clothing, and so on) and has provided data that are essential for the development of predictive exposure models of inadvertent ingestion exposure.     

Morphological assessment of pancreatic islet hormone content following aerobic exercise training in rats with poorly controlled Type 1 diabetes mellitus

Regular exercise has been shown to improve many complications of Type 1 diabetes mellitus (T1DM) including enhanced glucose tolerance and increased cardiac function. While exercise training has been shown to increase insulin content in pancreatic islets of rats with T1DM, experimental models were severely hyperglycemic and not undergoing insulin treatment. Further, research to date has yet to determine how exercise training alters glucagon content in pancreatic islets. The purpose of the present investigation was to determine the impact of a 10-week aerobic training program on pancreatic islet composition in insulin-treated rats with T1DM. Second, it was determined whether the acute, exercise-mediated reduction in blood glucose experienced in rats with T1DM would become larger in magnitude following aerobic exercise training. Diabetes was induced in male Sprague-Dawley rats by multiple low dose injections of streptozotocin (20mg/kg i.p.) and moderate intensity aerobic exercise training was performed on a motorized treadmill for one hour per day for a total of 10 weeks. Rats with T1DM demonstrated significantly less islet insulin, and significantly more islet glucagon hormone content compared with non-T1DM rats, which did not significantly change following aerobic training. The reduction in blood glucose in response to a single exercise bout was similar across 10 weeks of training. Results also support the view that different subpopulations of islets exist, as small islets (<50 μm diameter) had significantly more insulin and glucagon in rats with and without T1DM.     

Stress of AIDS caregiving: A preliminary overview of the issues

Abstract

This paper describes the stressors experienced by lovers and friends who were caregivers to AIDS patients and the social supports and coping strategies they drew on in efforts to mediate stress. From exploratory, intensive interviews with San Francisco men who provided care in their homes or those of the patients, three types of stressor were identified. One involves exigencies within the caregiver role itself, such as the demands and burdens encountered in housekeeping and nursing activities and in the management of financial and legal affairs. A second type of stressor involves the uncertainties caregivers experience concerning their own future, uncertainties that arise from the fact that homosexual caregivers are often exposed to the same set of health risk factors as the patients. Third, being a caregiver can create stressful problems in other roles. Thus, the demands of caregivmg can disrupt multiple areas of life-occupational, economic, and social. Once disrupted, these become independent sources of stress.

Formal and informal support systems appear to be important resources in sustaining caregivers and allowing them to continue in this role. In addition to support systems, a variety of coping strategies that may also help caregivers to sustain themselves have been identified. These strategies fall into three classes: those that function to minimize the physical and management demands of caregiving; cognitive and perceptual devices that reduce the level of threat the situation holds for the caregiver; and behaviors and practices that keep tensions and anxieties within manageable bounds.     

Beta 2-integrin and L-selectin are obligatory receptors in neutrophil aggregation [see comments]

We have recently found that antibodies to L-selectin, the homing receptor on neutrophils, are as effective as those to beta 2-integrin at blocking formyl peptide-stimulated aggregation. Therefore, we investigated the requirements for expression of L-selectin and beta 2- integrin on adjacent cells during aggregation. Fluorescence flow cytometry allowed characterization of aggregates on the basis of size and color, as well as antibody binding to these two adhesive molecules. Formyl peptide-stimulated aggregate formation was measured for individual populations fluorescently labeled red (LDS-751) or green (CD44-FITC), and interpopulation red-green cell conjugates. Blocking either the beta 2-integrin or L-selectin adhesive epitope with monoclonal antibody on individual cell populations resulted in an approximately 50% reduction in two-color aggregation as compared with that in unblocked samples. Shedding the L-selectin on a cell population by preincubation with complexes of lipopolysaccharide and its plasma membrane binding protein also decreased aggregation to a control population by approximately 50%. We examined the aggregation of neutrophils from patients genetically deficient in beta 2-integrin and clinically leukocyte adhesion deficient (LAD). LAD adhesion to normal neutrophils was dependent on the expression of L-selectin on LAD cells and beta 2-integrin on normal cells. Thus, the minimum requirement for adhesion between two mixed populations of neutrophils was that one population expressed the beta 2-integrin and the other expressed the L- selectin adhesive epitope.     

Buffering Syndemic Effects in a Sexual Risk-Reduction Intervention for Male Clients of Female Sex Workers: Results From a Randomized Controlled Trial

Objectives. We sought to test the efficacy of a sexual risk intervention for male clients of female sex workers (FSWs) and examine whether efficacy was moderated by syndemic risk.Methods. From 2010 to 2014, we conducted a 2-arm randomized controlled trial (60-minute, theory-based, safer sex intervention versus a didactic time-equivalent attention control) that included 400 male clients of FSWs on the US–Mexico border with follow-up at 4, 8, and 12 months. We measured 5 syndemic risk factors, including substance use and depression. Primary outcomes were sexually transmitted infections incidence and total unprotected sex with FSWs.Results. Although participants in both groups became safer, there was no significant difference in behavior change between groups. However, baseline syndemic risk moderated intervention efficacy. At baseline, there was a positive association between syndemic risk and unprotected sex. Then at 12 months, longitudinal analyses showed the association depended on intervention participation (B = −0.71; 95% confidence interval [CI] = –1.22, –0.20; P = .007). Among control participants there still existed this modest association (B = 0.36; 95% CI = –0.49, 1.22; P = .09); among intervention participants there was a significant negative association (B = −0.35; 95% CI = –0.63, –0.06; P = .02).Conclusion. A brief intervention might attenuate syndemic risks among clients of FSWs. Other populations experiencing syndemic problems may also benefit from such programs.Male clients of female sex workers (FSWs) represent a “bridge population” that has the potential to transmit HIV and sexually transmitted infections (STIs) between higher-risk groups (FSWs) and lower-risk groups (e.g., their wives).1–3 Globally, male clients of FSWs exhibit high-risk sexual behaviors,4–8 as well as higher STI incidence compared with other men.9 Unfortunately, little intervention work has targeted male clients.In 2007, Lowndes et al. implemented a behavioral intervention focusing on condom promotion among male clients of FSWs in Cotonou, Benin.10 Results suggested that male clients of FSWs in a resource-constrained country can reduce their sexual risk behavior through participation in a targeted behavioral intervention. However, this study lacked randomization and a control condition, precluding the ability to evaluate efficacy to reduce sexual risk behavior. A recent review of randomized trials and quasi-randomized trials of behavioral HIV prevention interventions among sex workers and clients did not identify a single randomized controlled trial targeted for male clients.11In Tijuana, Mexico, a border city along San Diego, California, there are an estimated 6000 to 10 000 FSWs offering sexual services to men from both countries.12 Tijuana has an HIV prevalence that is double the national average, and HIV is highest among high-risk groups including FSWs (approximately 6%).12–14In 2008, we conducted pilot research with 400 male clients of FSWs in Tijuana.13 HIV prevalence among clients was similar to that of FSWs (approximately 5%). Clients reported sex with an FSW an average of 26 times in the past year, once every 2 weeks in the past 4 months, and half reported recent unprotected sex with FSWs. Data were used to develop the first sexual risk-reduction intervention for male clients of FSWs. Herein, we aim to first evaluate the efficacy of our brief intervention, using the rigor of a randomized controlled trial. Whereas evaluating an intervention’s efficacy is a necessary step for HIV prevention, scientists must also examine for whom or under what conditions an intervention is efficacious (i.e., test moderators) to best inform prevention strategies both practically and theoretically.In addition to demonstrating risky sexual behavior, our pilot research with male clients in Tijuana showed that history of drug use was prevalent (88% reporting lifetime drug use) and was associated with unprotected sex with FSWs. These data also showed that the clients were more likely to engage in risky sex if they consumed alcohol at hazardous levels.15 Finally, our qualitative data suggested that vulnerability to HIV was associated with mental health problems like depression or loneliness.16,17 These findings are consistent with previous research on syndemic theory.Research has demonstrated the multiple co-occurrence of psychosocial problems (e.g., substance use, violence) and their additive effect on HIV risk behavior, called “syndemics.”18–21 While the specific factors that are included in the operationalization of a syndemic differ and depend on the specific population and region,21,22 studies have essentially found a dose–response relationship such that individuals who report more psychosocial problems are more likely to engage in higher sexual risk behavior or are more likely to be infected with HIV.23 The second aim of the current research was to examine syndemics as a potential moderator of intervention efficacy. In light of the important role that syndemics play in HIV across high-risk populations, and based on our pilot data, we hypothesized that men who experienced more syndemic problems at baseline would be more likely to benefit from the intervention than men who experienced fewer syndemic problems. Although our sexual risk-reduction intervention was not designed to directly address syndemic problems, it was based on cognitive behavioral therapy, social cognitive theory, and the theory of reasoned action, and we included in the intervention theoretical elements and motivational interviewing techniques designed to promote safer sex behavior by addressing perceived barriers to safer sex.     

Potassium influx into erythrocytes in essential hypertension

Sodium plus potassium (Na+K) cotransport in erythrocytes of patients with essential hypertension has mainly been studied elsewhere by measuring net outward frusemide-sensitive Na and K movements. We compared K influx (tracer 86 Rubidium) in control subjects and hypertensives who had never previously been treated for hypertension. The cotransport K influx rates in controls and hypertensives were 0.44 +/- 0.02 (mumol/ml cells/h; mean +/- s.e.; n = 20) and 0.67 +/- 0.06 (mumol/ml cells/h; mean +/- s.e.; n = 23) respectively. The active influxes were 1.03 +/- 0.03 and 2.06 +/- 0.13 (mumol/ml cells/h; mean +/- s.e.) respectively. The variance of both parameters was significantly greater in the hypertensive group but, taking this into account, the differences were significant (P less than 0.01).     

Acute lymphoblastic leukemia of childhood: identification of two distinct regions of deletion on the short arm of chromosome 12 in the region of TEL and KIP1

Cytogenetic analysis of acute lymphoblastic leukemia (ALL) of childhood identified nonrandom chromosomal abnormalities of the short arm of chromosome 12. The alterations include deletions that are thought to be indicative of the presence of a tumor suppressor gene that is mutated on the remaining allele. To refine further the chromosomal localization of this gene, we analyzed the loss of heterozygosity (LOH) of chromosome 12 in 100 primary ALL samples using 22 polymorphic markers and identified two distinct smallest common deleted regions on chromosome 12p13. One region is flanked by D12S77 and D12S98 and has a size of 4 cM. Twenty-six percent of informative patients showed LOH in this region. This region may contain the TEL gene. The other region is flanked by D12S269 and D12S308 including the KIP1 gene. Forty-four percent of informative patients showed LOH in this second region. Mutational analysis of KIP1 using polymerase chain reaction-single- strand conformation polymorphism analysis and Southern blot analysis showed no homozygous deletions and point mutations suggesting that the altered gene in this second region is not the KIP1. Clinical data showed that LOH of 12p was demonstrated more frequently in precursor-B ALLs (32 of 80; 40%) than in T-ALLs (1 of 20; 5%) (P = .0027). Furthermore, patients with 12p LOH were younger (P = .013), with a lower DNA index (P = .046), but they had the same survival rates at 3 years. In summary, these data suggest that two different tumor suppressor genes are on chromosome arm 12p, which act separately in the development of childhood precursor-B ALLs. One of the tumor suppressor genes is in the region the KIP1 gene, but our data suggest this gene is not abnormal. The other target is in the region of the TEL gene; and this candidate deserves further study.     

Exploring the utility of whole‐exome sequencing as a diagnostic tool in a child with atypical episodic muscle weakness

The advent of whole‐exome next‐generation sequencing (WES) has been pivotal for the molecular characterization of Mendelian disease; however, the clinical applicability of WES has remained relatively unexplored. We describe our exploration of WES as a diagnostic tool in a 3½‐year old female patient with a 2‐year history of episodic muscle weakness and paroxysmal dystonia who presented following a previous extensive but unrevealing diagnostic work‐up. WES was performed on the proband and her two parents. Parental exome data was used to filter potential de novo genomic events in the proband and suspected variants were confirmed using di‐deoxy sequencing. WES revealed a de novo non‐synonymous mutation in exon 21 of the calcium channel gene CACNA1S that has been previously reported in a single patient as a rare cause of atypical hypokalemic periodic paralysis. This was unexpected, as the proband's original differential diagnosis had included hypokalemic periodic paralysis, but clinical and laboratory features were equivocal, and standard clinical molecular testing for hypokalemic periodic paralysis and related disorders was negative. This report highlights the potential diagnostic utility of WES in clinical practice, with implications for the approach to similar diagnostic dilemmas in the future.