Polycystic ovary syndrome is an independent risk factor for hypertensive disorders of pregnancy: A systematic review, meta-analysis, and meta-regression.

PURPOSE: The risk of hypertensive disorders of pregnancy (HDP) in women with polycystic ovary syndrome (PCOS) is inconsistent in some studies. The aim of this meta-analysis was to examine the evidence regarding the strength of the association between PCOS and HDP. METHODS: PubMed, Web of Science, Embase, and the Cochrane Library were systematically searched to identify observational studies investigating HDP in patients with PCOS. The primary outcome was the pooled odds ratio (OR) of HDP, including pregnancy-induced hypertension (PIH) and pre-eclampsia (PE), in women with PCOS compared with the non-PCOS population. RESULTS: A total of 30 studies were eligible for meta-analysis. PCOS was associated with a higher risk of HDP (OR 2.02, 95CI% 1.83-2.22), including PIH (OR 1.94, 95CI% 1.70-2.21), and PE (OR 2.07, 95CI% 1.91-2.24). The association remained significant after adjusting for age, body mass index (BMI), and nulliparity (HDP: OR 1.48, 95CI% 1.48-1.60; PIH: OR 1.42, 95%CI 1.29-1.57; PE: OR 2.07, and 95%CI 1.91-2.24). The increased risk of HDP for the PCOS group remained significant in subgroups of BMI, Age, singleton pregnancy, multiple pregnancy, gestational diabetes mellitus (GDM), hyperandrogenism, and nulliparity, while the finding was not observed in subgroups of nonhyperandrogenic and non-GDM. In the meta-regression, BMI contributed significantly to the heterogeneity in the prevalence of HDP. CONCLUSIONS: PCOS is independently associated with a significantly increased risk of HDP. To prevent HDP during pregnancy, our findings highlight the importance of establishing supervision guidelines for PCOS patients, especially in the population with hyperandrogenism and GDM.

Limited Evidence for Sensory Prediction Error Responses in Visual Cortex of Macaques and Humans.

A recent formulation of predictive coding theory proposes that a subset of neurons in each cortical area encodes sensory prediction errors, the difference between predictions relayed from higher cortex and the sensory input. Here, we test for evidence of prediction error responses in spiking responses and local field potentials (LFP) recorded in primary visual cortex and area V4 of macaque monkeys, and in complementary electroencephalographic (EEG) scalp recordings in human participants. We presented a fixed sequence of visual stimuli on most trials, and violated the expected ordering on a small subset of trials. Under predictive coding theory, pattern-violating stimuli should trigger robust prediction errors, but we found that spiking, LFP and EEG responses to expected and pattern-violating stimuli were nearly identical. Our results challenge the assertion that a fundamental computational motif in sensory cortex is to signal prediction errors, at least those based on predictions derived from temporal patterns of visual stimulation.

Dual temporal encoding mechanisms in human auditory cortex: Evidence from MEG and EEG.

Current hypotheses about language processing advocate an integral relationship between encoding of temporal information and linguistic processing in the brain. All such explanations must accommodate the evident ability of the perceptual system to process both slow and fast time scales in speech. However most cortical neurons are limited in their capability to precisely synchronise to temporal modulations at rates faster than about 50Hz. Hence, a central question in auditory neurophysiology concerns how the full range of perceptually relevant modulation rates might be encoded in the cerebral cortex. Here we show with concurrent noninvasive magnetoencephalography (MEG) and electroencephalography (EEG) measurements that the human auditory cortex transitions between a phase-locked (PL) mode of responding to modulation rates below about 50Hz, and a non-phase-locked (NPL) mode at higher rates. Precisely such dual response modes are predictable from the behaviours of single neurons in auditory cortices of non-human primates. Our data point to a common mechanistic explanation for the single neuron and MEG/EEG results and support the hypothesis that two distinct types of neuronal encoding mechanisms are employed by the auditory cortex to represent a wide range of temporal modulation rates. This dual encoding model allows slow and fast modulations in speech to be processed in parallel and is therefore consistent with theoretical frameworks in which slow temporal modulations (such as rhythm or syllabic structure) are akin to the contours or edges of visual objects, whereas faster modulations (such as periodicity pitch or phonemic structure) are more like visual texture.

Sound envelope processing in the developing human brain: A MEG study.

OBJECTIVE: This study investigated auditory cortical processing of linguistically-relevant temporal modulations in the developing brains of young children. METHODS: Auditory envelope following responses to white noise amplitude modulated at rates of 1-80 Hz in healthy children (aged 3-5 years) and adults were recorded using a paediatric magnetoencephalography (MEG) system and a conventional MEG system, respectively. RESULTS: For children, there were envelope following responses to slow modulations but no significant responses to rates higher than about 25 Hz, whereas adults showed significant envelope following responses to almost the entire range of stimulus rates. CONCLUSION: Our results show that the auditory cortex of preschool-aged children has a sharply limited capacity to process rapid amplitude modulations in sounds, as compared to the auditory cortex of adults. SIGNIFICANCE: These neurophysiological results are consistent with previous psychophysical evidence for a protracted maturational time course for auditory temporal processing. The findings are also in good agreement with current linguistic theories that posit a perceptual bias for low frequency temporal information in speech during language acquisition. These insights also have clinical relevance for our understanding of language disorders that are associated with difficulties in processing temporal information in speech.

Cortical beta oscillations and motor thresholds differ across the spectrum of post-stroke motor impairment, a preliminary MEG and TMS study.

BACKGROUND: Cortical oscillatory activity in the beta frequency band (13-30Hz) is associated with voluntary movement and may be altered in motor disorders such as stroke. METHODS: We used a multimodal case-series approach to investigate movement-related beta oscillations, cortical excitability and upper-limb motor-function in 10 chronic stroke-patients across a broad range of motor-impairment. Assessments included: (i) whole-head magnetoencephalography (MEG) during a voluntary motor task; (ii) resting and active motor-thresholds to transcranial magnetic stimulation (TMS); and (iii) assessments of upper-limb motor-function. RESULTS: MEG revealed distinct patterns of movement-related beta oscillations according to motor-function. An elongated event-related desynchronisation (ERD) was correlated with poorer motor-function (p=0.004) whereas an elongated event-related resynchronisation (ERS) was correlated with higher motor function and lower TMS motor thresholds on the more-affected side (p=0.014 and p<0.001, respectively). Oscillation amplitude and laterality were also correlated with motor-function, where a stronger ERD/ERS and a greater relative contribution from the ipsilesional hemisphere were correlated with better motor-function (p=0.016, p=0.025). Unlike TMS responses and motor-function, the temporal profile of beta oscillations was largely symmetrical for movements of the more- and less-affected hands. CONCLUSIONS: Beta ERD/ERS patterns differ across the post-stroke motor impairment spectrum, and are bilaterally similar after stroke. Both the amplitude and duration of beta oscillations relate to post-stroke motor-function. SIGNIFICANCE: The contralesional hemisphere is not unaffected post-stroke. Caution is needed when generalising imaging and neurophysiological findings from patients with moderate to high motor ability to the more heterogeneous general stroke population and particularly those with low levels of residual voluntary motor-function.

Travelling backwards and forwards in time: culture and gender in the episodic specificity of past and future events.

There is considerable evidence that, when recalling past events, Westerners exhibit greater episodic specificity than East Asians and women exhibit greater episodic specificity than men. Yet it is unknown whether the same cultural and gender differences are true for future events. In the present study 209 European American and Chinese young adults were asked to recall past personal events and imagine future personal events occurring in varied time periods (i.e., 1 week, 1 year, 10-15 years). Regardless of time period, European Americans consistently produced more specific details than Chinese for future events than they did for past events, and women produced more specific details than men for both past and future events. These findings provide additional support for the constructive-episodic-simulation hypothesis, and shed new light on the influence of culture and gender on episodic thinking.

When we feel good and bad about ourselves: self-esteem memories across cultures.

Young adults in the United States, Croatia, and China described personal episodes of times when they felt especially good or bad about themselves. These self-esteem memories were either recent (episodes that occurred during the previous 4 weeks) or remote (episodes that occurred between the ages of 10 and 15). Systematic content differences between memories of positive and negative self-worth were apparent primarily for remote rather than for recent memories. Across cultures, long-lasting positive memories frequently represented achievement themes, whereas negative memories frequently represented social themes. Links between achievement success and positive self-regard, and between social distress and negative self-regard, are explained using theories of self-esteem and autobiographical memory.

[Influence of different doses of fentanyl on T-lymphocyte subpopulations and natural killer cells of patients with esophageal tumor during preoperation and postoperation].

BACKGROUND & OBJECTIVE: Morphine has been proved to inhibit human immune system, and large dose of fentanyl also decrease the activation of natural killer cells. This study was designed to investigate the effects of different doses of fentanyl on T-lymphocyte subpopulations and natural killer cells during esophageal cancer surgery under general anesthesia. METHODS: Forty-five patients with esophageal cancer were randomly divided into 3 groups (I, II,III) with 15 cases in each group respectively. The doses of fentanyl in three groups were 5, 10, and 20 microg/kg, respectively. Central venous blood samples (6 ml) were collected before anesthesia, 24 hours and 48 hours after the operation, respectively. Monoclonal antibodies assay was used to identify T cells and NK cells. RESULTS: The counts of CD3(+) (T%) (Group I 50.30+/-8.42, Group II 48.53+/-9.62, GroupIII 46.58+/-8.56), CD4(+) (T%) (Group I 30.04+/-7.24, Group II 28.67+/-7.52, Group III 26.65+/-6.55),and NK cells (Group I 3.26+/-1.62, Group II 3.01+1.56, GroupIII 3.01+/-1.54) in three groups decreased significantly at 24 hours after surgery (P< 0.01). The decrease at 48 hours after surgery were more significant in groupIII (CD3(+) 48.89+/-9.82, CD4(+) 22.64+/-6.02, NK Cells 3.41+/-1.88) than in group I(CD3(+) 57.32+/-9.13, CD4(+) 35.62+/-5.98, NK cells 5.96+/-1.08) and group II(CD3(+) 55.62+/-10.21, CD4(+) 34.24+/-6.85, NK cells 6.04+/-1.09) (P< 0.05). There was no statistical significance in the counts of CD3(+), CD4(+), and NK cells between the time of 48 hours after the operation and preoperation in group I and group II. CONCLUSION: Fentanyl, as a kind of opiate drug, could contribute to the immunosuppression, and large-dose fentanyl administration would be more effective in suppression of immunity function than small dose fentanyl.