Substrate-induced phase transition within liquid condensates reverses the catalytic activity of nanoparticles.

Liquid-liquid phase separation is reported to enhance the catalytic reaction rates severalfold. Herein, we explored the interactions between a catalyst and a range of substrate concentrations to understand the impact on the droplet phase and catalytic reaction kinetics. We observed that the substrate above a critical concentration induces phase transitions within liquid condensates and restricts the free movement of both the substrate and products, resulting in an overall reduction of the reaction rate, an observation not reported earlier.

Innate and engineered attributes of bacterial microcompartments for applications in bio-materials science.

Bacterial microcompartments (BMCs) are sophisticated all-protein bionanoreactors widely spread in bacterial phyla. BMCs facilitate diverse metabolic reactions, which assist bacterial survivability in normal (by fixing carbon dioxide) and energy dearth conditions. The past seven decades have uncovered numerous intrinsic features of BMCs, which have attracted researchers to tailor them for customised applications, including synthetic nanoreactors, scaffold nano-materials for catalysis or electron conduction, and delivery vehicles for drug molecules or RNA/DNA. In addition, BMCs provide a competitive advantage to pathogenic bacteria and this can pave a new path for antimicrobial drug design. In this review, we discuss different structural and functional aspects of BMCs. We also highlight the potential employment of BMCs for novel applications in bio-material science.

Barrier-free liquid condensates of nanocatalysts as effective concentrators of catalysis.

Traditional methods of molecular confinement have physicochemical barriers that restrict the free passage of substrates/products. Here, we explored liquid-liquid phase separation as a method to restrain protein-metal nanocomposites within barrier-free condensates. Confinement within liquid droplets was independent of the protein's native conformation and amplified the catalytic efficiency of metal nanocatalysts by one order of magnitude.

Antigen, allele, and haplotype frequencies report of the ASHI minority antigens workshops: part 1, African-Americans.

HLA typing was performed on 977 African Americans residing throughout most of the United States. Class I and class II antigens and class II alleles were defined for all individuals and class I alleles were determined for a subset of individuals. The occurrence of 854 of the individuals in family groups permitted direct counting of allele and haplotype frequencies. The data were analyzed for antigen, allele, and haplotype frequencies; recombination frequencies; segregation distortion; distribution of haplotype frequencies; linkage disequilibria; and geographic distribution of DR antigens. Tables of the antigen, allele, the most common two and three point haplotypes, and 88 extended haplotypes that include class I and class II alleles are presented. Notable findings include a lower than expected frequency of recombination between the B and DR loci (theta= 0.0013), lower than expected frequency of inheritance (44.5% vs 54.5%) of the DRB1*1503; DQB1*0602 haplotype, lower than anticipated linkage disequilibrium values for DR; DQ haplotypes, and a skewed geographic distribution of DR antigens.

Reflections on empowerment-based practice.

Social work education presents students with theories for understanding human beings and the social-historical contexts they share. These assumptions are supposed to make social workers' roles, practices, and agencies make sense. But where do they come from? How are the theories selected--and from among what alternatives? The people or licensing bodies choosing or approving these options control knowledge and inhibit knowing beyond the parameters of what they have designated for social work's knowledge base. What were the knowledge requirements or factors used to select prevailing theories about human behavior and the social environment or about social work practice? What happens to practitioners when feelings about their work contradicts what they were taught they should be thinking? This article is a reflection of formal social work learning interacting with the author's own social work experience. The article discusses what receiving knowledge (as opposed to sharing in producing or generating it) means for a practice supposedly committed to the social work values of human dignity and social justice. The experiences that led to the author's work on empowerment-based practice are presented and discussed. These experiences precipitated critical questioning that continues today.

Evaluation of pre- and posttransplant donor-specific transfusion/cyclosporine A in non-HLA identical living donor kidney transplant recipients. Cooperative Clinical Trials in Transplantation Research Group.

BACKGROUND: The beneficial effects of donor specific transfusion (DST) have become controversial in the cyclosporine era. This study was performed to evaluate the potential benefits of a new protocol for administering DSTs in the perioperative period. METHODS: Non-HLA identical living donor kidney transplant recipients were randomized prospectively to control or to receive a DST 24 hr before transplant and 7-10 days posttransplant. All patients received similar immunosuppression according to protocol. RESULTS: The protocol had 212 evaluable patients (115 transfused and 97 control). There were no differences in 1- and 2-year graft and patient survival, causes of graft failure, incidence and types of infection, repeat hospitalization, or the ability to withdraw steroids. Immunological hyporesponsiveness (by mixed lymphocyte culture) occurred more frequently in transfused patients (18%) than controls (3%) (P = 0.04). Blood stored for > or =3 days was associated with fewer early rejections than blood stored < or =2 days. Overall, class II antigen mismatches were associated with more rejection episodes than class I antigen mismatches. However, transfused patients, but not control patients, with more class I antigen mismatches were more likely to have rejections. CONCLUSIONS: Administration of DSTs by the method described had no practical influence on patient or graft survival for up to 2 years. However, donor-specific hyporesponsiveness was more common in transfused patients (18 vs. 3%). Longer follow-up will be needed to determine whether DST will be associated with long-term benefit.

Relationship between attachment-felt security and history of suicidal behaviours in clinical adolescents.

OBJECTIVE: This study was designed to test the hypothesis that adolescents who perceive their attachment figures as unavailable (low felt security) would be overrepresented in the case group of adolescents with a history of suicidal behaviours. METHOD: One hundred and eighty-seven adolescents in psychiatric treatment participated in this retrospective case-comparison study of attachment-felt security and history of suicidal behaviours. All participants completed the following measures: Adolescent Attachment Questionnaire, Perceived Social Support From Friends Scale, Rosenberg Self-Esteem Scale, Beck Hopelessness Scale, the depression syndrome scale of the Youth Self Report, and Adam's Suicidal Ideation and Behavior protocol. RESULTS: The comparison group comprised 101 adolescents who had never experienced suicidal ideation or behaviour; the case group included 86 adolescents with a history of suicidal behaviour. We found that perceived unavailability and high levels of depressive symptomatology were predictive of suicidal behaviours. We also found a strong association between being older and having high levels of angry distress in adolescents with a history of suicidal behaviours. CONCLUSION: The advantage of including an assessment of parent-adolescent attachment with clinical adolescents is noted.

Anxious attachment and severity of depressive symptomatology in women.

The present research evaluated a conceptual model that links anxious attachment to depressive symptomatology in women. Four hundred and twenty women completed the following measures: Socio-demographic questionnaire, the Centre for Epidemiological Studies Depression Scale (CES-D), the Reciprocal Attachment Questionnaire, the Social Support Questionnaire, the Rosenberg Self-Esteem Scale and the Global Assessment of Recent Stress Scale. Results indicate that feared loss of the attachment figure, intense proximity seeking and lack of use of the attachment figure were predictive of depressive symptomatology. We also found that lower levels of self-esteem and higher levels of recent stress were predictive of depressive symptomatology. The implications of these findings for the understanding of symptoms of depression in women is discussed.

A comparison of two measures to assess adult attachment.

The purpose of this study was to determine the relationship between two different approaches to the assessment of adult attachment. The approaches were C. Hazan and P. R. Shaver's (1987) categorization of three attachment styles and the dimensional system of the Reciprocal Attachment Questionnaire (RAQ; M. West & A. Sheldon-Keller, 1992). Participants were 196 (72 men and 124 women) respondents to a community survey. Multiple regression results showed that the three attachment groups differed significantly on three dimensions of the RAQ: feared loss of the attachment figure, perceived availability of the attachment figure, and use of the attachment figure. In addition, men and women differed significantly on use of the attachment figure, independent of their attachment style. The results indicate that the two approaches to the assessment of adult attachment are interrelated in meaningful ways.

Spinal ligament loading during axial distraction: a biomechanical model.

The objective of this study was to develop a method of measuring spinal ligament forces during axial distraction to understand the load-bearing contributions of the individual ligamentous structures in the lumbar spine. A sequential ligament-cutting technique and the arthroscopically implantable force probe (AIFP, MicroStrain, Burlington, VT) were used to determine loading of the anterior longitudinal ligament (ALL), the posterior longitudinal ligament (PLL), and the remaining posterolateral complex (PLC) in an in vitro corpectomy model. During axial spinal distraction, the relative percentages of the total axial load in the individual structures were as follows: ALL, 37.5%; PLL, 17.2%; PLC, 45.3%.

The effect of postoperative nonsteroidal anti-inflammatory drug administration on spinal fusion.

STUDY DESIGN: The influence of ketorolac on spinal fusion was studied in a retrospective review of 288 patients who underwent an instrumented spinal fusion. OBJECTIVE: To assess the effect of postoperative ketorolac administration on subsequent fusion rates. SUMMARY OF BACKGROUND DATA: Nonsteroidal anti-inflammatory drugs are widely used compounds, which are known to inhibit osteogenic activity and have been shown to decrease spinal fusion in an animal model. No previous studies have examined the influence of nonsteroidal anti-inflammatory drugs on spinal fusion in clinical practice. METHODS: The medical records of 288 patients who underwent instrumented spinal fusion from L4 to the sacrum between 1991 and 1993 were reviewed retrospectively. The 121 patients who received no nonsteroidal anti-inflammatory drugs were compared with the 167 patients who received ketorolac after surgery. The groups were demographically equivalent. RESULTS: Ketorolac had a significant adverse effect on fusion, with five nonunions in the nondrug group and 29 nonunions in the ketorolac group (P > 0.001). Ketorolac administration also significantly decreased the fusion rate for subgroups including men, women, smokers, and nonsmokers. The odds ratio demonstrated that nonunion was approximately five times more likely after ketorolac administration. Cigarette smoking also decreased the fusion rate (P > 0.01); smokers were 2.8 times more likely to develop nonunion. CONCLUSION: These data suggest that nonsteroidal anti-inflammatory drugs significantly inhibit spinal fusion at doses typically used for postoperative pain control. The authors recommend that these drugs be avoided in the early postoperative period.

Current options in prosthetic vascular graft infection.

Debate continues over which procedure is the best treatment for prosthetic graft infections. We retrospectively reviewed the medical records at our institution for all vascular graft infections that occurred from 1985 to 1995 to evaluate their occurrence, treatment, and outcome. Twenty-four patients had prosthetic graft infections. The average patient age was 62 years, and 67 per cent of the patients studied were men. The initial operation was for treatment of occlusive disease in 92 per cent of the patients, and aortofemoral bypasses were the most common procedures performed (15 of 24 patients, 63%). The average interval from graft implantation to presentation of infection was 29 months. In lower-extremity bypasses, the site of infection was most commonly in the groin (87%). Gram-positive organisms, including coagulase-negative Staphylococcus (32%) and Staphylococcus aureus (28%), were the most frequently isolated bacteria. Thirty procedures were performed for management of the graft infections. Extra-anatomic bypass was associated with no recurrent graft infections. Graft preservation was successful in two cases of early S. aureus infection (less than 1 year after original procedure), and in situ graft replacement was successful in all four cases of late-appearing coagulase-negative Staphylococcus infection (more than 1 year after original procedure). Both treatments failed in all five cases of Gram-negative infection (P = 0.008 by Fisher's exact test). The overall mortality and amputation rates were 17 per cent and 21 per cent, respectively, without significant differences between the treatment modalities. Extra-anatomic bypass remains the best treatment for prosthetic graft infection. In situ replacement and graft preservation treatments should be selective and based on presentation of the infection and the type of pathogenic organism.

Biomechanics of in situ rod contouring of short-segment pedicle screw instrumentation in the thoracolumbar spine.

In situ rod contouring is proposed as a means of three-dimensionally controlling the three columns of the spine. Our goal was to determine the biomechanical effectiveness of the technique for both clinical application and future research. Six cadaver specimens were tested with pedicle screw instrumentation from T12 to L2 in an L1 corpectomy model with all longitudinal ligaments retained across the defect. Contouring moment, anterior longitudinal ligament (ALL) forces, and distraction and lordosis across L1 were monitored. Rods were contoured to 26 degrees, and axial distraction averaged 6.9 mm. Bone/screw-interface failure began during contouring in every case < 10 degrees with no resulting increase in lordosis across L1. High tensile forces generated in the ALL resisted the moment applied by the rod benders and instead caused failure of the weaker bone/screw interface.

Safety and efficacy of early postoperative solid food consumption after cesarean section.

Traditionally patients have received a physician-dictated regimen of gradual expansion of their diets following cesarean section. This has been based upon concern about the possibility of ileus from expanding the diet too rapidly. Given the economic necessity of earlier postoperative discharge following abdominal delivery, many patients have solid food reintroduced in their diets around the time they leave the hospital. This prospective, randomized, controlled study compared a traditional, gradual dietary expansion scheme with patient-determined reintroduction of solid food, which was offered within eight hours of surgery. The hypotheses were that women would eat more rapidly after cesarean section when given the opportunity and that early solid food consumption would reduce the need for analgesia. The results indicated that both hypotheses were correct. Given the opportunity, women will eat solid food very soon after cesarean section (mean +/- SD 10.2 +/- 5.2 hours from surgery to onset of solid food consumption) as compared to women on a traditional dietary expansion regimen (mean +/- SD 41.5 +/- 16.0 hours, P < .001). Women offered food within hours of cesarean section required less patient-requested injectable narcotic postoperatively than did women on gradual dietary expansion (median, 75 mg versus 225 mg meperidine, P < .05). There was no evidence of compromise of safety or comfort from introducing solid food early and allowing the patient to decide when to eat postoperatively. The conclusion from these data is that early postoperative feeding after cesarean section is a safe and effective alternative for most women, who now face early hospital discharge.

Responding to hidden abuse: a role for social work in reforming mental health systems.

Clients in a state-funded intensive case management program, most of whom were identified as heavy users of acute care and psychiatric emergency rooms, had undetected brutal life experiences: 50 percent were adult children of alcoholics, and many were sexually and physically abused as children or adults. None had been asked about or appropriately treated for these aspects of their background. Statistical analysis indicated high levels of correlation between exposure to alcohol abuse in the family, physical or sexual abuse, repeated hospitalization, and contemporary suffering. Social work can use this and related data to make mental health systems more responsive to clients' needs at both the clinical and systems levels.

Acknowledging abuse backgrounds of intensive case management clients.

Routine inquiry about abuse experiences as children and adults yielded high levels of positive responses among 89 intensive case management clients. Through structured interviews administered by their case managers, clients disclosed backgrounds in families with one or more alcoholic adults, incest, other childhood sexual abuse, and extensive physical abuse. Gender played a major role. Being an ACOA also predicted extensive additional abuse. Clients were not treated for abuse, nor diagnosed for its impact, nor responded to when they initiated discussion with mental health providers. Later outcomes include frequent hospitalizations, substance abuse and self-mutilation.

Undetected abuse among intensive case management clients.

A study of the first 89 clients referred to an intensive case management program revealed substantial previously undetected physical and sexual abuse, yet none of the clients had ever been asked about their abuse experiences. Fifty percent of the clients were adult children of alcoholics, and 34 percent were childhood sexual abuse victims. The adult children of alcoholics experienced significantly more of every kind of abuse, including incest and childhood physical and sexual abuse, than clients whose parents were not alcoholic. Substance abuse problems were reported by more than half of the clients and by 75 percent of the adult children of alcoholics. Self-mutilation and heavy use of mental health services were also correlated with having an alcoholic parent. The authors suggest that mental health providers make routine inquiry about clients' family history of alcoholism and history of physical and sexual abuse.