Variant specific glycoprotein of Trypanosoma brucei consists of two domains each having an independently conserved pattern of cysteine residues

The complete amino acid sequences for nine variant specific glycoproteins (VSGs) of Trypanosoma brucei are presented. These have more than doubled the size of the VSG sequence data base and have enabled a new and more rigorous comparison to be made between amino acid sequences of different VSGs. Each VSG can be defined as a combination of an N-terminal domain type and a C-terminal domain type, based on the distribution of cysteine residues within the molecule. This identifies three N-terminal domain types and at least four C-terminal domain types. Different combinations of N and C-terminal domains can be formed; for example, in the sequences presented here, two different N-terminal domains are found in association with each of three different C-terminal domains. The biological context of the domain structure of VSGs is discussed.

2.9 A resolution structure of the N-terminal domain of a variant surface glycoprotein from Trypanosoma brucei

The variant surface glycoprotein (VSG) of Trypanosoma brucei forms a coat on the surface of the parasite; by the expression of a series of antigenically distinct VSGs in the surface coat the parasite escapes the host immune response. The 2.9 A resolution crystal structure of the N-terminal domain of one variant, MITat 1.2, has been determined. The structure was solved using data collected from two crystal forms. Initially a partial model was built into an electron density map based on multiple isomorphous replacement phases and improved by phase combination methods. Subsequently this model was used to obtain the molecular replacement solution for a second crystal form, providing starting phases which were refined using 2-fold non-crystallographic symmetry averaging. The current model includes 362 residues and has been refined using X-PLOR to an R value of 0.22 for data between 7 and 2.9 A. The molecule is a dimer, approximately 100 A long, having an asymmetrical cross section with maximum dimensions of approximately 40 A x 60 A. Two long, approximately 70 A, alpha-helices from each monomer pack together to form, with several other helices, a core helix bundle that extends nearly the full length of the molecule. The "top" of the protein, which in the surface coat may be exposed to the external environment, is formed from the ends of the two long helices, a short three-stranded beta-sheet, and a strand having irregular conformation that packs above these secondary structure elements. Two conserved disulfide bridges are in this part of the molecule. Several elements of the MITat 1.2 sequence, which contribute to the formation of the helix bundle structure, have been identified. These elements can be found in the sequences of several different VSGs, suggesting that to some extent the VSG structure is conserved in those variants.

Decreased recovery of CD4 lymphocytes in older HIV-infected patients beginning highly active antiretroviral therapy

Among virological responders, the area under the curve of the CD4 count minus baseline (AUCMB) after 3, 9, 15 and 18 months of highly active antiretroviral therapy (HAART) was less in individuals 55 years or older (P < 0.05). Fewer older individuals achieved increases of 50, 100, or over 150 CD4 cells/l. A random quadratic time course model estimated that the AUCMB decreased 35 cells/year for each 10 years of additional age during the first 12 months after HAART (P < 0.005).

Sexual function in 1,202 aging males: differentiating aspects

BACKGROUND

Late-life sexuality is an important quality-of-life issue that has been minimally explored. This survey seeks to extend our knowledge of the relationship of sexual attitudes and preferences to sexual functioning of a large group of older, community-dwelling men.

METHODS

Older men aged 58-94 (N = 1,202) were surveyed with an anonymous self-administered questionnaire including 63 items regarding present and past, actual and desired sexual practices and attitudes.

RESULTS

Although age correlated consistently with increased erectile dysfunction and decreased sexual activity, a substantial number of older men continued active sexual behaviors supported by positive attitudes toward sexual function. It was found that both health status and perceived partner's responsiveness are prominent moderators of the age effect.

CONCLUSION

In the absence of social isolation and health issues, many older men show persistently active sexual lifestyles as evidenced in their interest and participation in sexual activities. These findings negate a portion of the starkly negative imagery of sexual expression in aging males.

Sexuality and aging--usual and successful

BACKGROUND

As aging research increasingly reflects an effort to dissociate true time-driven changes from those that can be improved, sexuality in later life remains largely unexplored. Several problems are evident. There is a lack of normative data, a lack of a conceptual framework relating to the biology, psychology, and sociology of sex, and an attitudinal resistance that obscures the entire topic.

METHODS

We conducted a three-part instructional series on major topics involved with sexuality and aging. We surveyed our group of attendees (n 158, average age 68 for males, 65 for females) before and after the series.

RESULTS

A remarkably robust sex life was evidenced by both the men and the women, even until advanced old age. Yet, a substantially decreased involvement was reported from 10 years earlier. Despite current activities, people of both sexes wished they were participating even more than they currently were. Impotency was identified as the major negative feature for the men; relationship problems were for the women. A questionnaire 6 months after the series reported improved sexual attitudes, but no change in sexual activities from the earlier survey.

CONCLUSION

Sexuality is a major quality-of-life issue which persists into old age. Our study showed that the usual sexual practices reported by our group were not considered by them to be ideal. The intervention of this instructional series provided improved sexual attitudes but not performance. Additional studies are encouraged.

A comparison of two controlled-release delivery systems for the delivery of amiloride to control angiogenesis

The diuretic amiloride has been reported to inhibit both Na+-H+ antiport and the urokinase-type plasminogen activator. As a consequence of these inhibitions, neovascularization may also be inhibited. We hypothesized that if amiloride could be effectively delivered in a site-specific manner, a system might be developed that could inhibit localized angiogenesis. In order to evaluate this possibility we conducted a study that compared two different controlled-release systems into which amiloride had been incorporated. The effectiveness of amiloride release from each delivery system was determined by quantitating angiogenic patterns in a chick chorioallantoic membrane (CAM) system using a fractal analysis software program. The two delivery systems compared were sucrose acetate isobutyrate (SAIB) and calcium alginate. Initial HPLC laboratory tests confirmed that amiloride could be released from both SAIB and calcium alginate in vitro in a sustained manner for 72 h. The CAM studies confirmed that neither SAIB nor calcium alginate alone promoted or inhibited angiogenesis when compared to nontreated controls. The release of amiloride from each delivery vehicle resulted in a significant (P < 0.05) inhibition of angiogenesis following both 24 and 48 h of release compared to controls. There was no difference in inhibition of angiogenesis, however, when comparing SAIB + amiloride treated CAMs with calcium alginate + amiloride treated CAMs. These data suggest that both SAIB and calcium alginate may be useful delivery vehicles for the localized application of amiloride to control angiogenesis. Such a system could potentially control tumor angiogenesis without systemic effects.

Persistently seronegative men from whom HIV-1 has been isolated are genetically and immunologically distinct

Studies in both monkeys and humans have suggested that transient infection with HIV-1 can occur without provoking a measurable humoral immune response. The objective of this study was to look for genetic and immunologic correlates of transient HIV-1 infection in antibody-negative men from whom HIV-1 had been isolated. The distributions of MHC class I, class II, and TAP (transporter protein associated with antigen processing) region genes were compared between 23 persistently seronegative men from whom HIV-1 was isolated at least once (isol+/Ab-) and 137 men who seroconverted. A subset of 13 of the 23 isol+/Ab- men were compared to 27 seronegative men for distribution of CD25+CD4+ and CD25+CD8+ cells in the absence of exogenous immunologic stimulation. The prevalences of the TAP1.4, and a combination of TAP1.4, and TAP2.3 variants were significantly higher in the isol+/Ab- men. The proportion of CD8+ cells that expressed CD25+ antigen was also significantly higher in the isol+/Ab- men than in the seronegative men. We conclude that isol+/Ab- men may be genetically and immunologically distinct from HIV-1 susceptible men. We hypothesize that activated CD8+ cells may have cleared HIV-1 infection in these men through genetically mediated influences of the TAP genes on the presentation of peptides by HLA class I molecules.

Is Home Health Technology Adequate for Proactive Self-care?

Objective: To understand whether home health technology in the market and in development can satisfy the needs of patients and their non-professional caregivers for proactive support in managing health and chronic conditions in the home.

Methods: A panel of clinical providers and technology researchers was assembled to examine whether home health technology addresses consumer-defined requirements for self-care devices. A lexicon of home care and self-care technology terms was then created. A global survey of home health technology for patients with heart disease and dementia was conducted. The 254 items identified were categorized by conditions treated, primary user, function, and purpose. A focus group of patients and caregivers was convened to describe their expectations of self-care technology. Items identified in the database were then assessed for these attributes.

Results: Patients and family caregivers indicated a need for intelligent self-care technology which supports early diagnosis of health changes, intervention enablement, and improvement of communication quality among patients and the health care system. Of these, only intervention enablement was commonly found in the home health technology items identified.

Conclusions: An opportunity exists to meet consumer self-care needs through increased research and development in intelligent self-care technology.

Hyperthermic resuscitation is safe and effective after hemorrhagic shock in dogs

OBJECTIVE

To show that resuscitation from hypothermic, hemorrhagic shock using 65 degrees C intravenous fluid results in a more rapid return to euthermia compared with 40 degrees C intravenous fluid, without significant endothelial or hemolytic injury.

DESIGN

Fourteen anesthetized beagles (10-12 kg) were cooled to a core temperature of 30 degrees C and hemorrhaged to a mean arterial pressure of 40 to 45 mm Hg for 30 minutes. The animals were randomized to receive either 65 degrees C or 40 degrees C intravenous fluid through a specially designed catheter at a rate of 80% of their blood volume per hour until euthermic (37 degrees C) or for 2 hours.

MATERIALS AND METHODS

Blood pressure, pulmonary artery pressure, heart rate, and core temperature were continuously monitored. Blood samples were collected at baseline, after hemorrhage, 2 hours of resuscitation, and at postmortem examination after 7 days of survival. Laboratory measurements included complete blood count, plasma-free hemoglobin, and osmotic fragility. Values were compared using the Student's paired or unpaired t test with p approximately 0.05 indicating significance. Postmortem examination included light microscopy of the proximal superior vena cava or right atrium.

RESULTS

Animals receiving 65 degrees C intravenous fluid warmed 3.6 degrees C/hour, significantly faster than the 40 degrees C animals (1.9 degrees C/hour). There were no significant differences in plasma-free hemoglobin or osmotic fragility. Endothelial injuries were found in two animals in each group. These defects occurred along the path of catheter insertion and not at the infusion site.

CONCLUSIONS

Central intravenous fluid at 65 degrees C is a more rapid means of treating hypothermia than standard 40 degrees C intravenous fluid. It is safe even in hypovolemic animals.

Representations of Low(er) Alcohol (Craft) Beer in the United States

Given increasing social interest in health and wellness, rising cultural trends toward sobriety and moderating alcohol intake, and improvements in brewing technology, low(er) alcohol beer is a rising segment in the beer industry for both craft and larger-scale producers. In this paper, we assess the representation of low(er) alcohol beer among craft brewers in the United States. Using a novel quantitatively-informed qualitative analytical approach, we surveyed a randomized, non-representative sample of 400 craft brewery websites in the United States to assess the relative presence of low(er) alcohol beers as well as how these brews are represented by the breweries themselves. To do so, we recorded, both numerically and via website screenshots, the lowest ABV beverage on offer and noted the beer type, the beer name, and the ABV. Ales were the most prominent style of beer on offer, accounting for 62% of the low(er) ABV beers identified. Only 15.5% of the breweries surveyed in this study offered a beer with an ABV of less than 4%; however, an additional 67.9% offered a beer with an ABV of less than 5%. The representations of these low(er) alcohol products focused mostly on taste, health, and demographic indicators.

Abstract P3-15-01: The effect of participation in RCT on outcomes in patients with early breast cancer compared to the general breast cancer population

Background: Breast cancer trial enrollment, while slightly higher than some other histologies, still remains low, at less than 4%. Research suggests lack of clinical trial participation is due to poor patient and clinician commitment and interest. Increasing incentive for trial participation may enhance engagement of patients and healthcare providers leading to increased patient enrollment. One incentive would be to understand benefits of trial participation with regards to better survival and outcomes. The purpose of this study is to determine differences in survival, overall and breast cancer specific, and surgical management, for women who participate in early breast cancer randomized clinical trials (RCT) compared to the general breast cancer population who received similar standard therapy outside of a RCT.

Methods: Patients included in this retrospective analysis were from one of three (3) international, randomize, adjuvant breast cancer trials (RCT-participants) and women with breast cancer from the general U.S. population, from Surveillance Epidemiology and End Results Program (SEER-13), the controls. Women diagnosed between 1997-2004 with invasive breast cancer, tumor (T) size 1-3, lymph node (LN) positive (LN1/2), hormone receptor positive or negative, HER2 positive or negative, treated with surgery, adjuvant radiation, and chemotherapy were included in the analysis. In this study, propensity score analysis (PSA) was done to provide weight to each data point for each variable in order to more closely represent similar populations. PSA, considered superior to a standard Cox multivariate analysis as it attempts to reduce the bias due to confounding or correlated predictive variables. Subsequently, the propensity score was applied to a Cox proportional hazards model to determine hazard ratios (HR), with a Wald 95% confidence interval (CI), of trial participation on survival. Similarly, PSA was done for surgical outcomes. A multivariate logistic regression was performed to calculate the odds ratios, with a Wald 95% CI, to determine if RCT participation compared to the SEER-13 control had an impact on surgical outcomes, mastectomy versus breast conserving surgery (BCS).

Results: The total sample size was 9255 patients, 1795 RCT-participants and 7460 SEER-13 controls. After controlling for all other significant predictors of survival, RCT participation significantly reduced risk of breast cancer related death at 5-years by more than 25% and 18% at 10 years [HR: 0.75 (95% CI: 0.64-0.87); p=0.00020; and HR: 0.83 (95% CI: 0.74-0.93); p=0.00165, respectively]. Additionally, we demonstrated a significant reduction in risk of all-cause mortality for RCT-participants, at both 5-years and 10-years [HR: 0.83 (95% CI: 0.72--0.95); p=0.009; and HR: 0.79 (95% CI: 0.71-0.87); p&lt;0.00001, respectively]. Additionally, RCT-participants were significantly less likely to undergo invasive surgical management (mastectomy) compared to SEER-13 controls [OR: 0.78 (95% CI: 0.66-0.92;) p=0.03].

Conclusion: RCT-participants have a reduced risk of death at 5 years and 10 years compared to the general breast cancer population. Additionally, RCT-participants are less likely to undergo mastectomy than the SEER-13 controls.

Citation Format: Brennan MB, Wiley D, Wang D, Wang X, Fasching P. The effect of participation in RCT on outcomes in patients with early breast cancer compared to the general breast cancer population [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-15-01.