Effects of a formal exercise program on Parkinson's disease: a pilot study using a delayed start design

INTRODUCTION

Parkinson's Disease (PD) is a progressive neurodegenerative disease. Increasing evidence shows that physical exercise is beneficial for motor and non-motor symptoms of PD, and animal models suggest that it may help slow progression of disease.

METHODS

Using a randomized delayed-start design, 31 patients were randomized to an early start group (ESG) or a delayed start group (DSG) exercise program. The ESG underwent a rigorous formal group exercise program for 1 h, three days/week, for 48 weeks (November 2011-October 2012). The DSG participated in this identical exercise program from weeks 24-48. Outcome measures included the Unified Parkinson's Disease Rating Scale (UPDRS), Walking Test (get-up-and-go), Tinetti Mobility Test, PDQ-39 Questionnaire, and the Beck Depression Inventory.

RESULTS

There was minimal attrition in this study, with only one patient dropping out. Results did not show improvement in total UPDRS scores with early exercise. At week 48, the mean change from baseline total UPDRS score was 6.33 in the ESG versus 5.13 in the DSG (p = 0.58). However, patients randomized to the ESG scored significantly better on the Beck Depression Inventory, with a mean improvement of 1.07 points relative to those in the DSG (p = 0.04).

CONCLUSIONS

The findings demonstrate that long-term, group exercise programs are feasible in the Parkinson's disease population, with excellent adherence and minimal drop out. While the outcome measures used in our study did not provide strong evidence that exercise has a neuroprotective effect on motor function, earlier participation in a group exercise program had a significant effect on symptoms of depression.

Distinct long-term neurocognitive outcomes after equipotent sevoflurane or isoflurane anaesthesia in immature rats

BACKGROUND

Many anaesthetics when given to young animals cause cell death and learning deficits that persist until much later in life. Recent attempts to compare the relative safety or toxicity between different agents have not adequately controlled for the relative dose of anaesthetic given, thereby making direct comparisons difficult.

METHODS

Isoflurane or sevoflurane were given at 1 minimum alveolar concentration (MAC) for 4 h to postnatal day 7 (P7) rat pups. Beginning at P75 these animals underwent fear conditioning and at P83 Morris water maze testing to assess working memory, short-term memory and early long-term memory using delays of 1 min, 1 h, and 4 h.

RESULTS

No difference between groups was seen in fear conditioning experiments. Morris water maze learning was equivalent between groups, and no difference was seen in working memory. Sevoflurane-treated animals had a deficit in early long-term memory, and isoflurane-treated animals had a deficit in both short-term and early long-term memory.

CONCLUSIONS

Both isoflurane and sevoflurane delivered at 1 MAC for 4 h to immature rats caused a deficit in long-term memory. Isoflurane also caused a deficit in short-term memory. Isoflurane might be more detrimental than sevoflurane in very young animals.

Replication of genetic loci for ages at menarche and menopause in the multi-ethnic Population Architecture using Genomics and Epidemiology (PAGE) study

STUDY QUESTION

Do genetic associations identified in genome-wide association studies (GWAS) of age at menarche (AM) and age at natural menopause (ANM) replicate in women of diverse race/ancestry from the Population Architecture using Genomics and Epidemiology (PAGE) Study?

SUMMARY ANSWER

We replicated GWAS reproductive trait single nucleotide polymorphisms (SNPs) in our European descent population and found that many SNPs were also associated with AM and ANM in populations of diverse ancestry.

WHAT IS KNOWN ALREADY

Menarche and menopause mark the reproductive lifespan in women and are important risk factors for chronic diseases including obesity, cardiovascular disease and cancer. Both events are believed to be influenced by environmental and genetic factors, and vary in populations differing by genetic ancestry and geography. Most genetic variants associated with these traits have been identified in GWAS of European-descent populations.

STUDY DESIGN, SIZE, DURATION

A total of 42 251 women of diverse ancestry from PAGE were included in cross-sectional analyses of AM and ANM.

MATERIALS, SETTING, METHODS

SNPs previously associated with ANM (n = 5 SNPs) and AM (n = 3 SNPs) in GWAS were genotyped in American Indians, African Americans, Asians, European Americans, Hispanics and Native Hawaiians. To test SNP associations with ANM or AM, we used linear regression models stratified by race/ethnicity and PAGE sub-study. Results were then combined in race-specific fixed effect meta-analyses for each outcome. For replication and generalization analyses, significance was defined at P < 0.01 for ANM analyses and P < 0.017 for AM analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

We replicated findings for AM SNPs in the LIN28B locus and an intergenic region on 9q31 in European Americans. The LIN28B SNPs (rs314277 and rs314280) were also significantly associated with AM in Asians, but not in other race/ethnicity groups. Linkage disequilibrium (LD) patterns at this locus varied widely among the ancestral groups. With the exception of an intergenic SNP at 13q34, all ANM SNPs replicated in European Americans. Three were significantly associated with ANM in other race/ethnicity populations: rs2153157 (6p24.2/SYCP2L), rs365132 (5q35/UIMC1) and rs16991615 (20p12.3/MCM8). While rs1172822 (19q13/BRSK1) was not significant in the populations of non-European descent, effect sizes showed similar trends.

LIMITATIONS, REASONS FOR CAUTION

Lack of association for the GWAS SNPs in the non-European American groups may be due to differences in locus LD patterns between these groups and the European-descent populations included in the GWAS discovery studies; and in some cases, lower power may also contribute to non-significant findings.

WIDER IMPLICATIONS OF THE FINDINGS

The discovery of genetic variants associated with the reproductive traits provides an important opportunity to elucidate the biological mechanisms involved with normal variation and disorders of menarche and menopause. In this study we replicated most, but not all reported SNPs in European descent populations and examined the epidemiologic architecture of these early reported variants, describing their generalizability and effect size across differing ancestral populations. Such data will be increasingly important for prioritizing GWAS SNPs for follow-up in fine-mapping and resequencing studies, as well as in translational research.

Patient characteristics associated with the decision to undergo bilateral prophylactic mastectomy for lobular carcinoma in situ

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Background: Women at increased risk for breast cancer due to a diagnosis of lobular carcinoma in situ (LCIS) have three management options: high risk surveillance +/- chemoprevention (CP) or bilateral prophylactic mastectomy (BPM). Among a large cohort of women with LCIS, we previously reported there were no differences between women choosing CP compared to those choosing surveillance alone. The purpose of this study was to identify patient factors associated with the decision to pursue BPM for LCIS.

Methods: We reviewed our prospectively maintained LCIS database to identify women choosing BPM (1995-2009). Comparisons were made between patients who chose BPM versus those who chose high risk surveillance +/- CP.

Results: Among 995 pts with LCIS, 795 (80%) chose surveillance alone, 149 (15%) chose CP and 51 (5%) chose BPM. Compared to patients electing surveillance +/- CP patients who pursued BPM were younger at age of LCIS diagnosis (48 vs. 52 yrs, p < 0.001), more likely to have bilateral biopsies with LCIS (14% vs. 3%, p = 0.002) and more likely to be premenopausal (82% vs. 57%, p < 0.001). Patients choosing BPM were also more likely to have additional risk factors for breast cancer including: stronger family histories and extremely dense breasts (Table). Occult breast cancer was found in 4 (8%) BPM patients. At a median follow-up of 54 months (range 0-190 mos), 120/944 (13%) patients in the surveillance +/- CP group developed breast cancer.

Conclusions: High-risk surveillance alone is the preferred management option for women with LCIS at our institution. Patients electing BPM are younger and more likely to have other associated risk factors for developing breast cancer. Further research to define how the increased risk imparted by LCIS is augmented by these factors may allow for better risk stratification and more informed discussions with patients.

[Table: see text]

Differential roles of MAPK-Erk1/2 and MAPK-p38 in insulin or insulin-like growth factor-I (IGF-I) signaling pathways for progesterone production in human ovarian cells

Insulin and insulin like-growth factor-I (IGF-I) participate in the regulation of ovarian steroidogenesis. In insulin resistant states ovaries remain sensitive to insulin because insulin can activate alternative signaling pathways, such as phosphatidylinositol-3-kinase (PI-3 kinase) and mitogen-activated protein-kinase (MAPK) pathways, as well as insulin receptors and type 1 IGF receptors. We investigated the roles of MAPK-Erk1/2 and MAPK-p38 in insulin and IGF-I signaling pathways for progesterone production in human ovarian cells. Human ovarian cells were cultured in tissue culture medium in the presence of varying concentrations of insulin or IGF-I, with or without PD98059, a specific MAPK-Erk1/2 inhibitor, with or without SB203580, a specific MAPK-p38 inhibitor or with or without a specific PI-3-kinase inhibitor LY294002. Progesterone concentrations were measured using radioimmunoassay. PD98059 alone stimulated progesterone production in a dose-dependent manner by up to 65% (p<0.001). Similarly, LY294002 alone stimulated progesterone production by 13-18% (p<0.005). However, when used together, PD98059 and LY294002 inhibited progesterone production by 17-20% (p<0.001). SB203580 alone inhibited progesterone production by 20-30% (p<0.001). Insulin or IGF-I alone stimulated progesterone production by 40-60% (p<0.001). In insulin studies, PD98059 had no significant effect on progesterone synthesis while SB203580 abolished insulin-induced progesterone production. Either PD98059 or SB203580 abolished IGF-I-induced progesterone production. Both MAPK-Erk1/2 and MAPK-p38 participate in IGF-I-induced signaling pathways for progesterone production, while insulin-induced progesterone production requires MAPK-p38, but not MAPK-Erk1/2. These studies provide further evidence for divergence of insulin and IGF-I signaling pathways for human ovarian cell steroidogenesis.

Handedness Effects on Playing a Reversed or Normal Keyboard

A group of left-handers, approaching the piano for the first time, showed better performance in playing a reversed keyboard (where the pitch decreased from left to right) than a normal keyboard. By testing a separate group of "experienced" left-handers, it was also found that this observed preference that naive left-handers had for the reversed keyboard can disappear with a few years of practice on a normal keyboard. The initial preference for the reversed keyboard shown by left-handers appeared to be specific for this handedness group, as groups of right-handers, regardless of their level of experience with the piano, performed better with the regular keyboard. Finally, based on these results it was hypothesised that left-handers would encounter considerable frustration in learning the "right-handed" piano. However, an informal demographic study of piano students enrolling at a school of music did not reveal a substantially low prevalence of left-handed pianists.