Fall frequency and associated factors among men and women with or at risk for HIV infection

OBJECTIVES

Falls and fall-related injuries are a major public health concern. HIV-infected adults have been shown to have a high incidence of falls. Identification of major risk factors for falls that are unique to HIV infection or similar to those in the general population will inform development of future interventions for fall prevention.

METHODS

HIV-infected and uninfected men and women participating in the Hearing and Balance Substudy of the Multicenter AIDS Cohort Study and Women's Interagency HIV Study were asked about balance symptoms and falls during the prior 12 months. Falls were categorized as 0, 1, or ≥ 2; proportional odds logistic regression models were used to investigate relationships between falls and demographic and clinical variables and multivariable models were created.

RESULTS

Twenty-four per cent of 303 HIV-infected participants reported at least one fall compared with 18% of 233 HIV-uninfected participants (P = 0.27). HIV-infected participants were demographically different from HIV-uninfected participants, and were more likely to report clinical imbalance symptoms (P ≤ 0.035). In univariate analyses, more falls were associated with hepatitis C, female sex, obesity, smoking, and clinical imbalance symptoms, but not age, HIV serostatus or other comorbidities. In multivariable analyses, female sex and imbalance symptoms were independently associated with more falls. Among HIV-infected participants, smoking, a higher number of medications, and imbalance symptoms remained independent fall predictors, while current protease inhibitor use was protective.

CONCLUSIONS

Similar rates of falls among HIV-infected and uninfected participants were largely explained by a high prevalence of imbalance symptoms. Routine assessment of falls and dizziness/imbalance symptoms should be considered, with interventions targeted at reducing symptomatology.

Neither Intraocular Grafts of Retinal Cell Homogenates Nor Live Non-Retinal Neurons Produce Behavioral Recovery in Rats with Light-Damaged Retinas

Previously we have observed that fetal retinal cells grafted to the subretinal space of blind rats produced a functional recovery as determined by testing the visual inhibition of the startle response. Following those studies, we performed experiments to test whether the injection itself, cell by-products, or unrelated neural cells could also produce an effect. Visual function was tested by examining the inhibitory effect of a brief light flash (300 Ix) on the acoustic startle response to an immediately following intense noise burst in light blinded Fischer 344 rats. Animals were tested before and after grafts of fetal retinal cell homogenates, dissociated perinatal cerebellar cells, and sham injections in the subretinal space. Behavioral testing continued every 2 wk for 14 wk after the graft. In the pretests, the light flash inhibited the startle response, maximal at intervals of 40-70 ms with recovery thereafter. In contrast, after exposure for 4 wk to fluorescent light (300 lx) and a rest in a normal 12/12 h light/ dark environment the rats showed reflex facilitation to the light, maximal at an interval of 110 ms, followed by a late period of reflex inhibition. The light flash had no effect on other rats that had been blinded by bilateral enucleation. Light blinded animals receiving either cerebellar grafts or retinal cell homogenates were no different in performance from their sham injected control animals. The present data suggest that neither subretinal injections of neural cells nor nonspecific neurochemical factors are able to elicit a positive behavioral response in visually impaired animals.

Storage of Human Fetal Retina in Optisol Prior to Subretinal Transplantation

We have previously reported that Optisol, a commercially available medium (Chiron Vision, Irvine, CA), is a favorable fluid for the storage of neural retina. We now characterize the cell survival and histologic integrity of the tissue following storage and then transplantation. Neural retinas from human fetal eyes obtained within 1 h of pregnancy termination were stored in Optisol-GS medium (containing TC-199 and MEM medium, 2.5% chondroitin sulfate, 1% dextran, HEPES buffer, gentamicin sulfate, 0.1 mmol/L nonessential amino acids, sodium bicarbonate, 1 mmol/L sodium pyruvate, and additional antioxidants), at 4°C for the following time periods: 0, 1, 2, and 7 days, and then tested for viability. Retinas stored for 2 and 7 days were mechanically dissociated and grafted into the eyes of light-damaged Fischer 344 rats (17 animals, 28 eyes). Non-transplanted eyes received injections of vehicle only (5 animals, 6 eyes). All animals were immunosuppressed daily with cyclosporine (10 mg/kg). All experiments were conducted in strict accordance with institutional, federal, and ARVO guidelines. Cell viability averaged 94.8%, 90.2%, 83.2%, and 76.8% at 0, 1, 2, and 7 days storage, respectively. Light microscopy demonstrated that the fetal retina was preserved without evident changes for up to 48 h. Up to 7 days there was a good to very good preservation of the cells in the outer neuroblastic layer. One month after transplantation subretinal grafts of retinal tissue stored for 2 and 7 days in Optisol showed good integration with host retina and initial photoreceptor differentiation. Optisol is a widely used medium for the preservation of human corneas prior to transplantation. Our results show that this medium is also highly suitable for preserving human fetal retinas prior to transplantation.

Hearing Loss and Quality of Life (QOL) among Human Immunodeficiency Virus (HIV)-Infected and Uninfected Adults

OBJECTIVE

Research has established that human immunodeficiency virus (HIV) causes hearing loss. Studies have yet to evaluate the impact on quality of life (QOL). This project evaluates the effect of hearing loss on QOL by HIV status.

METHODS

The study participants were from the Multicenter AIDS Cohort Study (MACS) and the Women's Interagency HIV study (WIHS). A total of 248 men and 127 women participated. Pure-tone air conduction thresholds were collected for each ear at frequencies from 250 through 8000 Hz. Pure-tone averages (PTAs) for each ear were calculated as the mean of air conduction thresholds in low frequencies (i.e., 250, 500, 1000 and 2000 Hz) and high frequencies (i.e., 3000, 4000, 6000 and 8000 Hz). QOL data were gathered with the Short Form 36 Health Survey and Medical Outcome Study (MOS)-HIV instrument in the MACS and WIHS, respectively. A median regression analysis was performed to test the association of PTAs with QOL by HIV status.

RESULTS

There was no significant association between hearing loss and QOL scores at low and high pure tone averages in HIV positive and negative individuals. HIV status, HIV biomarkers and treatment did not change the lack of association of low and high pure tone averages with poorer QOL.

CONCLUSION

Although we did not find a statistically significant association of hearing loss with QOL by HIV status, testing for hearing loss with aging and recommending treatment may offset any presumed later life decline in QOL.

Mycoplasma hominis and Gardnerella vaginalis display a significant synergistic relationship in bacterial vaginosis

Gardnerella vaginalis plays an important role in bacterial vaginosis (BV,) while the role of genital Mollicutes is less obvious. The diagnosis of BV by use of the current Gram stain Nugent score is also suboptimal for defining the role of Mollicutes that lack a cell wall. Since bacterial load and diversity is an important prerequisite for BV, real-time quantitative polymerase chain reaction (qPCR) assays enable these to be assessed. The purpose of this study was to define the role of genital Mollicutes and potential patterns of synergy with G. vaginalis in women with BV. Vaginal swabs from 130 women categorised by Nugent score as BV (n = 28), intermediate (n = 22) and non-BV (n = 80) were tested against four qPCR TaqMan assays targeting G. vaginalis, Mycoplasma hominis, M. genitalium, Ureaplasma urealyticum and U. parvum. Statistical analyses were used to compare bacterial prevalence and load between the three groups of women. Mycoplasma hominis and G. vaginalis co-infection was significantly more common in BV (60.7 %) compared to intermediate (36.4 %) and non-BV (8.8 %) Nugent scores (p < 0.001). Significantly higher loads of M. hominis (p = 0.001) and G. vaginalis (p < 0.001) were detected in women with BV and the respective loads in M. hominis and G. vaginalis co-infections displayed a significant positive correlation (p < 0.001; r = 0.60). No significant associations were seen with the other Mollicutes. The findings strengthen the evidence of a role for M. hominis in BV and a potential synergy with G. vaginalis. This synergy could be an important trigger of the condition and sexual contact the conduit for the transmission of an otherwise commensal bacterium that could initiate it.

Evaluation of caffeine and the development of necrotizing enterocolitis

OBJECTIVE

To test the association between medical or surgical necrotizing enterocolitis (NEC) and caffeine administration in premature infants.

STUDY DESIGN

This single-center, retrospective study evaluated patients admitted to a level 3 neonatal intensive care unit (NICU) over an 18-month period. All patients were evaluated for factors associated with the development of NEC including exposure to caffeine (dosing and duration), gestational age, birth weight, vasoactive medications and maternal illicit drug use.

RESULTS

There were 615 subjects included in the study; among these subjects, 7.3% (n = 45) developed NEC (35 subjects receiving caffeine and 10 subjects not receiving caffeine). The administration of caffeine (p = 0.008), birth weight (p = 0.014) and the use of vasopressors (p = 0.033) were associated with the development of NEC. When considering only infants with a birth weight less than 1500 g and less than 32 weeks gestation, the effects of caffeine and vasopressor use remained statistically significant (p = 0.047 and p = 0.045, respectively). The time to development of NEC did not differ statistically between patients receiving caffeine and those not receiving caffeine (p = 0.129).

CONCLUSION

A potential association between the administration of caffeine and the development of medical or surgical necrotizing enterocolitis in premature infants exists. Further investigation of dose-dependent effects and loading doses is warranted.

Species-specific responses of N homeostasis and electrolyte handling to low N intake: a comparative physiological approach in a monogastric and a ruminant species

In our former studies low crude protein (LCP) intake influenced N homeostasis and electrolyte handling in goats. We hypothesised that due to rumino-hepatic nitrogen (N) recycling adaptation of N homeostasis and adjustment of electrolyte handling to LCP intake differs between goats and monogastric animals. Therefore, an experiment similar to that with goats was conducted with rats. Two feeding groups received a diet either containing 20 or 8 % crude protein (as fed basis) for 5 weeks and intake and excretion of N, calcium (Ca) and phosphorus (P) were determined. To detect systemic and endocrine adaptation to LCP intake plasma concentrations of urea, Ca, phosphate (Pi), insulin-like growth factor 1 (IGF-1), 1,25-dihydroxyvitamin D3 (calcitriol), parathyroid hormone (PTH) and cross-linked telopeptide of type I collagen (CTX) were measured. Adjustment of renal electrolyte transport was assessed by detecting protein expression of key proteins of renal Pi transport. All data were compared with the data of the goat experiment. LCP intake decreased plasma urea concentration stronger in goats than in rats. In both species urinary N excretion declined, but faecal N excretion decreased in goats only. Furthermore, in goats urinary Ca excretion decreased, but in rats urinary Ca concentration increased. Decreased plasma IGF-1 and calcitriol concentrations were found in goats only. Thus, renal Ca excretion appears to be a common target in adaptation of electrolyte homeostasis in both species, but is regulated differently.

HIBAG--HLA genotype imputation with attribute bagging

Genotyping of classical human leukocyte antigen (HLA) alleles is an essential tool in the analysis of diseases and adverse drug reactions with associations mapping to the major histocompatibility complex (MHC). However, deriving high-resolution HLA types subsequent to whole-genome single-nucleotide polymorphism (SNP) typing or sequencing is often cost prohibitive for large samples. An alternative approach takes advantage of the extended haplotype structure within the MHC to predict HLA alleles using dense SNP genotypes, such as those available from genome-wide SNP panels. Current methods for HLA imputation are difficult to apply or may require the user to have access to large training data sets with SNP and HLA types. We propose HIBAG, HLA Imputation using attribute BAGging, that makes predictions by averaging HLA-type posterior probabilities over an ensemble of classifiers built on bootstrap samples. We assess the performance of HIBAG using our study data (n=2668 subjects of European ancestry) as a training set and HLA data from the British 1958 birth cohort study (n≈1000 subjects) as independent validation samples. Prediction accuracies for HLA-A, B, C, DRB1 and DQB1 range from 92.2% to 98.1% using a set of SNP markers common to the Illumina 1M Duo, OmniQuad, OmniExpress, 660K and 550K platforms. HIBAG performed well compared with the other two leading methods, HLA*IMP and BEAGLE. This method is implemented in a freely available HIBAG R package that includes pre-fit classifiers for European, Asian, Hispanic and African ancestries, providing a readily available imputation approach without the need to have access to large training data sets.

What is the burden of axillary disease after neoadjuvant therapy in women with locally advanced breast cancer?

BACKGROUND

The burden of axillary disease in patients with locally advanced breast cancer (labc) after neoadjuvant therapy (nat) has not been extensively described in a large modern cohort. Here, we describe the extent of nodal metastases after nat in patients with labc.

METHODS

All patients with labc treated at a single institution during 2002-2007 were identified. Demographic, radiologic, and pathologic variables were extracted. To assess the extent of lymph node metastases after nat, patients were separated into two groups: those with and without clinical or radiologic evidence of lymph node metastases before nat. Axillary lymph nodes retrieved at surgery that had no evidence of metastases after hematoxylin and eosin (h&e) staining underwent further pathology evaluation.

RESULTS

Of the 116 patients identified, 115 were female (median age: 48.5). Before nat, 26 patients were clinically and radiologically node-negative; of those 26, 14 were histologically negative on final pathology. After serial sectioning and immunohistochemistry, 9 of 26 (35%) were node-negative. Of the 90 patients who had clinical or radiologic evidence of lymph node metastases before nat, 23 (26%) had no evidence of lymph node metastases on h&e staining. After serial sectioning and immunohistochemistry, 19 (21%) had no further axillary lymph node metastases. Overall, 76% of patients had pathology evidence of lymph node metastases after nat.

CONCLUSIONS

Most patients with labc have axillary metastases after nat. Our findings support axillary lymph node dissection and locoregional radiation in most patients with labc after nat.

Abstract OT3-4-02: MINT I: Multi-Institutional Neo-adjuvant Therapy, MammaPrint Project I

Background: Women with locally advanced breast cancer (LABC) are often treated with neo-adjuvant chemotherapy to reduce the size of the tumor prior to surgery, to enable breast conserving surgery and to observe the clinical effect of therapy in real time. Studies have shown that the 25–27% of individuals who have a pathologic complete response (pCR) to neoadjuvant therapy have a survival advantage of 80% in 5 years, which is double the expected survival of the remaining patients without pCR. If patients who are likely to show a pCR could be identified prior to initiation of therapy, it would enable more informed treatment decisions – patients likely to respond would be served well by current neoadjuvant chemotherapy protocols, while those unlikely to respond may be better suited to innovative new strategies for drug discovery [von Minckwitz et al. JCO 2006]. Genomics assays, which are widely used to provide prognostic and predictive information in early breast cancer, have the potential to provide information on the likelihood of a patient with LABC responding to neo-adjuvant therapy [Glück et al. ASCO 2012].

Trial design: MINT I is a prospective study designed to test the ability of molecular profiling, as well as traditional pathologic and clinical prognostic factors, to predict responsiveness to neo-adjuvant chemotherapy in patients with LABC. MammaPrint risk profile, BluePrint molecular subtyping profile, TargetPrint estrogen receptor (ER), progesterone receptor (PR) and HER2 single gene readout, and the 56-gene TheraPrint Research Gene Panel will be analyzed on a fresh tumor specimen using the whole genome array. Patients will receive neo-adjuvant chemotherapy pre-specified in the protocol. Response will be measured centrally. pCR is defined as the absence of invasive carcinoma in both the breast and axilla at microscopic examination of the resection specimen, regardless of the presence of carcinoma in situ.

Eligibility: The study will include women ≥18 years with histologically-proven invasive breast cancer T2 (≥3.5cm)-T4, N0M0 or T2-T4N1M0, adequate bone marrow reserves and normal renal and hepatic function who signed an IRB approved informed consent.

Objectives: The objectives of the study are to: 1. Determine the predictive power of MammaPrint and BluePrint for sensitivity to neo-adjuvant chemotherapy as measured by pCR.2. Compare TargetPrint ER, PR and HER2 with local and centralized IHC and/or CISH/FISH assessment.3. Identify correlations between TheraPrint and response to neo-adjuvant chemotherapy.4. Identify and/or validate predictive gene expression profiles of clinical response or resistance to neo-adjuvant chemotherapy.5. Compare BluePrint with IHC-based subtype classification.

Statistical methods: Standard statistical tests such as the Pearson Chi-square test will be used to characterize and evaluate the relationship between chemoresponsiveness and gene expression patterns.

Accrual: A total of 226 eligible patients will be enrolled from multiple institutions. To date (June 06, 2012), 31 patients have been enrolled.

Clinical trial registry number: NCT01501487.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT3-4-02.

East pacific rise: hot springs and geophysical experiments

Hydrothermal vents jetting out water at 380 degrees +/- 30 degrees C have been discovered on the axis of the East Pacific Rise. The hottest waters issue from mineralized chimneys and are blackened by sulfide precipitates. These hydrothermal springs are the sites of actively forming massive sulfide mineral deposits. Cooler springs are clear to milky and support exotic benthic communities of giant tube worms, clams, and crabs similar to those found at the Galápagos spreading center. Four prototype geophysical experiments were successfully conducted in and near the vent area: seismic refraction measurements with both source (thumper) and receivers on the sea floor, on-bottom gravity measurements, in situ magnetic gradiometer measurements from the submersible Alvin over a sea-floor magnetic reversal boundary, and an active electrical sounding experiment. These high-resolution determinations of crustal properties along the spreading center were made to gain knowledge of the source of new oceanic crust and marine magnetic anomalies, the nature of the axial magma chamber, and the depth of hydrothermal circulation.