Genetic and environmental contributions to the expression of handedness in chimpanzees (Pan troglodytes)

Most humans are right-handed and, like many behavioral traits, there is good evidence that genetic factors play a role in handedness. Many researchers have argued that non-human animal limb or hand preferences are not under genetic control but instead are determined by random, non-genetic factors. We used quantitative genetic analyses to estimate the genetic and environmental contributions to three measures of chimpanzee handedness. Results revealed significant population-level handedness for two of the three measures-the tube task and manual gestures. Furthermore, significant additive genetic effects for the direction and strength of handedness were found for all three measures, with some modulation due to early social rearing experiences. These findings challenge historical and contemporary views of the mechanisms underlying handedness in non-human animals.

Reduced α-synuclein levels in cerebrospinal fluid in Parkinson's disease are unrelated to clinical and imaging measures of disease severity

BACKGROUND AND PURPOSE

The cerebrospinal fluid (CSF) concentration of α-synuclein may reflect the aggregation of α-synuclein in brain tissue that neuropathologically characterizes Parkinson's disease (PD). Although most studies in large cohorts report reduced CSF α-synuclein levels in PD, the available data to date are not consistent due to variation in group sizes, pre-analytical confounding factors and assay characteristics. Furthermore, it remains unclear whether CSF α-synuclein concentrations correlate with measures of disease severity. Acknowledging the methodological issues that emerged from previous studies, we evaluated whether CSF α-synuclein levels differ between patients with PD and controls, and relate to disease duration or severity.

METHODS

α-Synuclein levels were measured in CSF samples of 53 well-characterized patients with PD and 50 healthy controls employing a recently developed time-resolved Förster's resonance energy transfer assay. In addition, we studied the relationship of CSF α-synuclein levels with disease duration, clinical measures of disease severity and the striatal dopaminergic deficit as measured by dopamine transporter binding and single photon emission computed tomography.

RESULTS

In patients with PD, we observed a decrease in mean CSF α-synuclein levels that was unrelated to disease duration or measures of disease severity. Using total protein normalized α-synuclein, a sensitivity and specificity of 70% and 74% could be reached for distinguishing between patients with PD and controls.

CONCLUSION

CSF α-synuclein levels are reduced in patients with PD compared with healthy controls. However, sensitivity and specificity indicate that α-synuclein will not suffice as a single biomarker. CSF α-synuclein levels do not correlate with measures of disease severity, including striatal dopaminergic deficit.

Therapy of desmoid tumors, fibromatosis, and related neoplasms

Forty-seven patients with unresectable desmoid tumors and 32 patients with unresectable fibromatosis were treated with various anti-neoplastic agents including methotrexate, vinblastine, etoposide, actinomycin D, and fluorouracil. A combination of methotrexate with either vinblastine or etoposide was found to be effective in yielding long-term control to both groups of patients. Fluorouracil and actinomycin D were less effective. Other than a significant but slowly reversible peripheral neuropathy in 6 patients, therapy was well tolerated and no long-term hematologic, pulmonary, hepatic, or cardiac toxicity was noted in any patient.

Hormone supplementation during aging: how much and when?

Circulating levels of dehydroepiandrosterone, a major adrenal steroid, show a marked age-related decrease in both humans and nonhuman primates. Because this decrease has been implicated in age-related cognitive decline, we administered supplementary dehydroepiandrosterone to perimenopausal rhesus macaques (Macaca mulatta) to test for cognitive benefits. Although recognition memory improved, there was no benefit to spatial working memory. To address the limitations of this study we developed a hormone supplementation regimen in aged male macaques that more accurately replicates the 24-hr androgen profiles of young animals. We hypothesize that this more comprehensive physiological hormone replacement paradigm will enhance cognitive function in the elderly.

Enhanced beta cell proliferation in mice overexpressing a constitutively active form of Akt and one allele of p21Cip

AIMS/HYPOTHESIS

The ability of pancreatic beta cells to proliferate is critical both for normal tissue maintenance and in conditions where there is an increased demand for insulin. Protein kinase B(Akt) plays a major role in promoting proliferation in many cell types, including the insulin-producing beta cells. We have previously reported that mice overexpressing a constitutively active form of Akt(caAkt (Tg)) show enhanced beta cell proliferation that is associated with increased protein levels of cyclin D1, cyclin D2 and cyclin-dependent kinase inhibitor 1A (p21(Cip)). In the present study, we sought to assess the mechanisms responsible for augmented p21(Cip) levels in caAkt(Tg) mice and test the role of p21(Cip) in the proliferative responses induced by activation of Akt signalling.

METHODS

To gain a greater understanding of the relationship between Akt and p21(Cip), we evaluated the mechanisms involved in the modulation of p2(Cip) by Akt and the in vivo role of reduced p21(Cip) in proliferative responses induced by Akt.

RESULTS

Our experiments showed that Akt signalling regulates p21(Cip) transcription and protein stability. caAkt(Tg) /p21(Cip+/-) mice exhibited fasting and fed hypoglycaemia as well as hyperinsulinaemia when compared with caAkt(Tg) mice. Glucose tolerance tests revealed improved glucose tolerance in caAkt(Tg)/p21(Cip+/-) mice compared with caAkt (Tg). These changes resulted from increased proliferation, survival and beta cell mass in caAkt(Tg)/p21(Cip+/-) compared with caAkt(Tg) mice.

CONCLUSIONS/INTERPRETATION

Our data indicate that increased p21(Cip) levels in caAkt(Tg) mice act as a compensatory brake, protecting beta cells from unrestrained proliferation. These studies imply that p21(Cip) could play important roles in the adaptive responses of beta cells to proliferate in conditions such as in insulin resistance.

Empty follicle syndrome: successful treatment in a recurrent case and review of the literature

Empty follicle syndrome is a condition in which no oocytes are retrieved after an apparently adequate ovarian response to stimulation and meticulous follicular aspiration. It is a rare condition of obscure etiology. A patient with primary infertility who underwent seven assisted reproductive technique cycles is described. In spite of a satisfactory ovarian response, aspiration yielded no oocytes in four cycles and 1-4 low quality oocytes in three cycles. In the index treatment cycle, ovulation was triggered using GnRH agonist 40 h prior to ovum pickup and hCG was added 6 h after the first trigger. Eighteen oocytes were recovered, of which 16 were mature and were inseminated by ICSI. Two embryos were transferred 48 h after aspiration and nine embryos were cryopreserved. The patient conceived and delivered a healthy boy at 38 weeks of gestation. The literature is reviewed and possible etiologies and treatment options of this enigmatic syndrome are suggested.

An instrumented timed up and go: the added value of an accelerometer for identifying fall risk in idiopathic fallers

The Timed Up and Go (TUG) test is a widely used measure of mobility and fall risk among older adults that is typically scored using a stopwatch. We tested the hypothesis that a body-fixed accelerometer can enhance the ability of the TUG to identify community-living older adults with a relatively high fall risk of unknown origin. Twenty-three community-living elderly fallers (76.0 ± 3.9 years) and 18 healthy controls (68.3 ± 9.1 years) performed the TUG while wearing a 3D-accelerometer on the lower back. Acceleration-derived parameters included Sit-to-Stand and Stand-to-Sit times, amplitude range (Range), and slopes (Jerk). Average step duration, number of steps, average step length, gait speed, acceleration-median, and standard-deviation were also calculated. While the stopwatch-based TUG duration was not significantly different between the groups, acceleration-derived TUG duration was significantly higher (p = 0.007) among the fallers. Fallers generally exhibited lower Range and Jerk (p < 0.01). While TUG stopwatch duration successfully identified 63% of the subjects, an accelerometer-derived three-measure-combination correctly classified 87% of the subjects. Accelerometer-derived measures were generally not correlated with TUG duration. These findings demonstrate that fallers have difficulty with specific TUG aspects that can be quantified using an accelerometer. Without compromising simplicity of testing, an accelerometer can apparently be combined with TUG duration to provide complementary, objective measures that allow for a more complete, sensitive TUG-based fall risk assessment.

Multidisciplinary Canadian consensus recommendations for the management and treatment of hepatocellular carcinoma

Globally, hepatocellular carcinoma (hcc) is the third most common cause of death from cancer, after lung and stomach cancer. The incidence of hcc in Canada is increasing and is expected to continue to increase over the next decade. Given the high mortality rate associated with hcc, steps are required to mitigate the impact of the disease. To address this challenging situation, a panel of 17 hcc experts, representing gastroenterologists, hepatologists, hepatobiliary surgeons, medical oncologists, pathologists, and radiologists from across Canada, convened to provide a framework that, using an evidence-based approach, will assist clinicians in optimizing the management and treatment of hcc. The recommendations, summarized here, were developed based on a rigorous methodology in a pre-specified process that was overseen by the steering committee. Specific topics were identified by the steering committee and delegated to a group of content experts within the expert panel, who then systematically reviewed the literature on that topic and drafted the related content and recommendations. The set of recommendations for each topic were reviewed and assigned a level of evidence and grade according to the levels of evidence set out by the Centre for Evidence-based Medicine, Oxford, United Kingdom. Agreement on the level of evidence for each recommendation was achieved by consensus. Consensus was defined as agreement by a two-thirds majority of the 17 members of the expert panel. Recommendations were subject to iterative review and modification by the expert panel until consensus could be achieved.