Global hotspots and trends in research on preschool children's motor development from 2012 to 2022: a bibliometric analysis.

Background: Motor development plays an important role in human development throughout the lifespans, from conception to death, and has received increasing scholarly attention in recent years. However, valuable comprehensive reviews and literature analysis on this topic are still lacking. Here, this bibliometric study aimed to identify global motor development research hotspots and trends on preschool children's motor development from 2012 to 2022. Methods: CiteSpace 6.1.R4 was used to visualize and analyze general bibliometric characteristics, research hotspots, and trends through a review of 2,583 articles on the motor development of preschool children, which were published from 2012 to 2022 and included in the Web of Science Core Collection. Results: Research on motor development in preschool children has been carried out into a phase of rapid development. The top five frequently occurring keywords were physical activity (n = 489), performance (n = 319), intervention (n = 222), health (n = 196), and executive function (n = 165); The top five keywords in terms of centrality are academic achievement (0.22), low birth weight (0.16), association (0.14), brain (0.13), and cerebral palsy (0.13). Thirteen keyword clusters were produced from the log-likelihood ratio (Q = 0.74, S = 0.88), and five research topics has been received focused attention in recent years. The keywords with the strongest citation bursts in the last 5 years are developing country (S = 5.92), school-aged children (S = 5.86), middle-income country (S = 3.46), efficacy (S = 5.41), readiness (S = 3.21), motor proficiency (S = 3.6), and screen time (S = 3.3), indicating newly emerging research trends. Conclusion: The results indicated that interventions involving fundamental movement skills, cognitive function, 24-h movement behaviors, neurodevelopmental disorders, and health-related fitness were hot topics in the field of motor development over the last decade. Emerging research trends generally center on school readiness, socioeconomic status, motor proficiency, and screen time.

Relationships between physical activity, fundamental motor skills, and body mass index in preschool children.

Purpose: To investigate whether there is a potential relationship between physical activity (PA), fundamental motor skills (FMS), and Body Mass Index (BMI) in preschool children and to further explore the differences in PA and FMS between normal-weight and overweight/obese preschool children. Method: Participants were 366 preschool children aged 3 to 6 years; 358 completed all tests (194 boys and 164 girls). PA, FMS, body weight, and height were measured by triaxial accelerometer, the Test of Gross Motor Development, Second Edition (TGMD-2), and anthropometry measurement, respectively. Result: The overall rate of overweight/obesity was 17.0%, with no significant gender difference (χ 2 = 0.628, p = 0.428). Older children perform significantly better in both object control skills and locomotor skills. Independent samples t-tests were used to examine the difference between genders on FMS and PA: girls in the 5-year-old group display better locomotor skills (p = 0.012) than boys. Boys spent more time on moderate-to-vigorous physical activity (MVPA) and less time on sedentary activity when compared to girls. Results of partial correlation analysis showed that PA was significantly and positively correlated with both locomotor skills and object control skills in preschool children (p < 0.01), while there was no correlation between FMS, PA level, and BMI. Results of ANCOVA revealed no significant difference in FMS between normal-weight and overweight or obese preschool children; normal-weight girls had significantly longer MPA and MVPA duration and significantly shorter sedentary periods than overweight or obese girls (p < 0.05). Conclusion: Overweight/obesity in preschool children requires effective measures. PA is positively associated with FMS, while BMI is not potentially related to FMS or PA in preschool years. Overweight or obese girls should develop healthier weight status by increasing MVPA hours and reducing sedentary time.

Alzheimer's disease with sleep insufficiency: a cross-sectional study on correlations among clinical characteristics, orexin, its receptors, and the blood-brain barrier.

Previous studies have shown that reduced sleep duration, sleep fragmentation, and decreased sleep quality in patients with Alzheimer's disease are related to dysfunction in orexin signaling. At the same time, blood-brain barrier disruption is considered an early biomarker of Alzheimer's disease. However, currently no report has examined how changes in orexin signaling relate to changes in the blood-brain barrier of patients who have Alzheimer's disease with sleep insufficiency. This cross-sectional study included 50 patients with Alzheimer's disease who received treatment in 2019 at Beijing Tiantan Hospital. Patients were divided into two groups: those with insufficient sleep (sleep duration ≤ 6 hours, n = 19, age 61.58 ± 8.54 years, 10 men) and those with normal sleep durations (sleep duration > 6 hours, n = 31, age 63.19 ± 10.09 years, 18 men). Demographic variables were collected to evaluate cognitive function, neuropsychiatric symptoms, and activities of daily living. The levels of orexin, its receptor proteins, and several blood-brain barrier factors were measured in cerebrospinal fluid. Sleep insufficiency was associated with impaired overall cognitive function that spanned multiple cognitive domains. Furthermore, levels of orexin and its receptors were upregulated in the cerebrospinal fluid, and the blood-brain barrier was destroyed. Both these events precipitated each other and accelerated the progression of Alzheimer's disease. These findings describe the clinical characteristics and potential mechanism underlying Alzheimer's disease accompanied by sleep deprivation. Inhibiting the upregulation of elements within the orexin system or preventing the breakdown of the blood-brain barrier could thus be targets for treating Alzheimer's disease.

Cornuside Is a Potential Agent against Alzheimer's Disease via Orchestration of Reactive Astrocytes.

Cornuside is an iridoid glycoside from Cornus officinalis, with the activities of anti-inflammatory, antioxidant, anti-mitochondrial dysfunction, and neuroprotection. In the present research, a triple-transgenic mice model of AD (3 × Tg-AD) was used to explore the beneficial actions and potential mechanism of cornuside on the memory deficits. We found that cornuside prominently alleviated neuronal injuries, reduced amyloid plaque pathology, inhibited Tau phosphorylation, and repaired synaptic damage. Additionally, cornuside lowered the release of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and nitric oxide (NO), lowered the level of malondialdehyde (MDA), and increased the activity of superoxide dismutase (SOD) and the level of glutathione peroxidase (GSH-Px). Cornuside also significantly reduced the activation of astrocytes and modulated A1/A2 phenotypes by the AKT/Nrf2/NF-κB signaling pathway. We further confirmed that LY294002 and Nrf2 silencing could block the cornuside-mediated phenotypic switch of C6 cells induced by microglia conditioned medium (MCM) in response to lipopolysaccharide (LPS), which indicated that the effects of cornuside in astrocyte activation are dependent on AKT/Nrf2/NF-κB signaling. In conclusion, cornuside may regulate the phenotypic conversion of astrocytes, inhibit neuroinflammation and oxidative stress, improve synaptic plasticity, and alleviate cognitive impairment in mice through the AKT/Nrf2/NF-κB axis. Our present work provides an experimental foundation for further research and development of cornuside as a candidate drug for AD management.

Clinical Features and Potential Mechanisms Relating Neuropathological Biomarkers and Blood-Brain Barrier in Patients With Alzheimer's Disease and Hearing Loss.

Background: The aim of this study was to explore clinical features and potential mechanisms relating neuropathological biomarkers and blood-brain barrier (BBB) in Alzheimer's disease (AD) and hearing loss (HL). Materials and Methods: A total of 65 patients with AD were recruited and auditory function was assessed by threshold of pure tone audiometry (PTA). Patients were divided into AD with HL (AD-HL) and AD with no HL (AD-nHL) groups based on the standard of World Health Organization. Clinical symptoms were assessed by multiple rating scales. The levels of neuropathological biomarkers of ß amyloid1-42 (Aß1-42) and multiple phosphorylated tau (P-tau), and BBB factors of matrix metalloproteinases (MMPs), receptor of advanced glycation end products, glial fibrillary acidic protein, and low-density lipoprotein receptor related protein 1 were measured. Results: (1) Compared with AD-nHL group, AD-HL group had significantly impaired overall cognitive function and cognitive domains of memory, language, attention, execution, and activities of daily living (ADL) reflected by the scores of rating scales (P < 0.05). PTA threshold was significantly correlated with the impairments of overall cognitive function and cognitive domains of memory and language, and ADL in patients with AD (P < 0.05). (2) P-tau (S199) level was significantly increased in CSF from AD-HL group (P < 0.05), and was significantly and positively correlated with PTA threshold in patients with AD. (3) MMP-3 level was significantly elevated in CSF from AD-HL group (P < 0.05), and was significantly and positively correlated with PTA threshold in patients with AD (P < 0.05). (4) In AD-HL group, P-tau (S199) level was significantly and positively correlated with the levels of MMP-2 and MMP-3 in CSF (P < 0.05). Conclusion: AD-HL patients have severely compromised overall cognitive function, multiple cognitive domains, and ADL. The potential mechanisms of AD-HL involve elevations of AD neuropathological biomarker of P-tau (S199) and BBB factor of MMP-3, and close correlations between P-tau (S199) and MMP-2/MMP-3 in CSF. Findings from this investigation highly suggest significance of early evaluation of HL for delaying AD progression, and indicate new directions of drug development by inhibiting neuropathological biomarkers of AD and protecting BBB.

Luteolin alleviates cognitive impairment in Alzheimer's disease mouse model via inhibiting endoplasmic reticulum stress-dependent neuroinflammation.

Luteolin is a flavonoid in a variety of fruits, vegetables, and herbs, which has shown anti-inflammatory, antioxidant, and anti-cancer neuroprotective activities. In this study, we investigated the potential beneficial effects of luteolin on memory deficits and neuroinflammation in a triple-transgenic mouse model of Alzheimer's disease (AD) (3 × Tg-AD). The mice were treated with luteolin (20, 40 mg · kg-1 · d-1, ip) for 3 weeks. We showed that luteolin treatment dose-dependently improved spatial learning, ameliorated memory deficits in 3 × Tg-AD mice, accompanied by inhibiting astrocyte overactivation (GFAP) and neuroinflammation (TNF-α, IL-1ß, IL-6, NO, COX-2, and iNOS protein), and decreasing the expression of endoplasmic reticulum (ER) stress markers GRP78 and IRE1α in brain tissues. In rat C6 glioma cells, treatment with luteolin (1, 10 µM) dose-dependently inhibited LPS-induced cell proliferation, excessive release of inflammatory cytokines, and increase of ER stress marker GRP78. In conclusion, luteolin is an effective agent in the treatment of learning and memory deficits in 3 × Tg-AD mice, which may be attributable to the inhibition of ER stress in astrocytes and subsequent neuroinflammation. These results provide the experimental basis for further research and development of luteolin as a therapeutic agent for AD.

Potential roles of oxidative distress on neurodegeneration in Parkinson's disease with neuropsychiatric symptoms.

Background: Neuropsychiatric symptoms (NPSs) belong to a category of non-motor symptoms of Parkinson's disease (PD), which seriously compromise the quality of life and prognosis of PD. This study focused on the correlations between NPSs, free radicals, neuroinflammatory factors, and neuropathological proteins in cerebrospinal fluid (CSF) in patients with PD, aiming to provide insights into the potential mechanisms and therapeutic target for PD with NPSs (PD-NPSs). Methods: In total, 129 patients with PD were enrolled and assessed by the Neuropsychiatric Symptoms Inventory (NPI); they were divided into the PD-NPSs group (75 patients) and PD with no NPSs (PD-nNPSs) group (54 patients). The levels of hydrogen peroxide (H2O2) and nitric oxide (NO), and hydroxyl radical (·OH), anti-oxidative enzyme, neuroinflammatory factors, and neuropathological proteins in CSF from patients with PD were measured. The levels of the above variables were compared between PD-NPSs and PD-nNPSs groups, and correlation analyses among the above variables were conducted. Results: (1) The levels of H2O2 and NO in CSF from the PD-NPSs group were significantly elevated compared with the PD-nNPSs group (p = 0.001), and NPI score positively correlated with the levels of H2O2 and NO (r = 0.283, P = 0.001; r = 0.231, P = 0.008). Reversely, total superoxide dismutase (tSOD) activity in CSF from the PD-NPSs group was significantly reduced compared with the PD-nNPSs group (p = 0.011), and negatively correlated with NPI score (r = -0.185, p = 0.036). (2) The tumor necrosis factor (TNF)-α level in CSF from the PD-NPSs group was significantly decreased compared with the PD-nNPSs group (p = 0.002) and negatively correlated with NPI score (r = -0.211, p = 0.016). (3) The total tau (T-tau) level in CSF from the PD-NPSs group was significantly higher than in the PD-nNPSs group (p = 0.014) and positively correlated with the NPI score (r = 0.167, p = 0.060). (4) The levels of H2O2 and NO positively correlated with the T-tau level in CSF from the PD-NPSs group (r = 0.183, p = 0.039; r = 0.251, P = 0.004), and the levels of TNF-α and T-tau showed a negative correlation (r = -0.163, p = 0.067). Conclusion: Oxidative distress characterized by the elevations of H2O2 and NO levels may closely correlate with the neurodegeneration in brain regions related to PD-NPSs. Thus, therapeutic antioxidants may become an important target for PD-NPSs therapy.

Gender differences in self-harm and drinking behaviors among high school students in Beijing, China.

BACKGROUND: Self-harm and drinking are both serious problems in adolescents and many studies presented evidence of their association. However, gender differences in this association are seldom deeply discussed. Our study aimed to evaluate the prevalence of self-harm and explore its association with drinking behaviors by gender and investigate the extent to which the gender differences exist in the association between self-harm and drinking. METHODS: A total of 32,362 students in grades 7 to 12 in Beijing, China were anonymously surveyed and included in our study using two-stage, stratified probability proportion sampling. Self-harm, drinking behaviors and other basic information were obtained from an anonymous questionnaire. Demographic variables, self-harm and drinking behaviors were analyzed using the Chi-square test and the Gamma test between genders and the gender differences in this association were analyzed by Log-binomial regression. RESULTS: The total prevalence of self-harm was 13.7% with no significant gender difference (χ2 =0.352, P = 0.553). The prevalence of self-harm in girls decreased with age (G = -0.163, P < 0.001). Self-harm was associated with drinking behaviors in both boys and girls. The Log-binomial regression demonstrated that girls in the 16-19 years old group were at lower risk of self-harm than girls in the 12-15 years old group while this association was weaker in boys (1.493 vs 1.128). The higher OR for self-harm was found among girls with early drinking experiences compared with boys (2.565 vs 1.863). Girls who had previously drunk (i.e. drunk at least once) (2.211 vs 1.636), were currently drinking (3.400 vs 2.122) and performed binge drinking (6.357 vs 3.924) were at greater risk of self-harm than boys. CONCLUSION: Among high school students, self-harm has a significant positive association with drinking and girls with drinking behaviors are at higher risk of suffering self-harm. Identifying adolescents' drinking behaviors is of vital importance to self-harm prevention and special attention should be focused on younger girls.

Reducing Anemia Among School-Aged Children in China by Eliminating the Geographic Disparity and Ameliorating Stunting: Evidence From a National Survey.

Background: The aim of this study was to assess the geographic disparity in anemia and whether stunting was associated with anemia in different geographic groups among school-aged children in China. Methods: 71,129 Han children aged 7, 9, 12, and 14 years old were extracted from the 2014 cycle of Chinese National Surveys on Children Constitution and Health. Anemia, anemia severity, and stunting were defined according to WHO definitions. Binary logistic regression models were used to estimate the association between anemia and stunting in different geographic groups. Results: The prevalence of anemia was significantly higher in girls (10.8%) than boys (7.0%). The highest anemia prevalence was in Group VII (lower class/rural, 12.0%). A moderate/severe prevalence of anemia was concentrated in Group VII and Group VIII (western/lower class/rural) for both sexes. The prevalence of anemia was higher in stunting boys than non-stunting boys in Group IV (lower class/city, χ2 = 12.78, P = 0.002) and Group VII (χ2 = 6.21, P = 0.018), while for girls, it was higher in stunting girls than their non-stunting peers only in Group II (upper class/large city, χ2 = 4.57, P = 0.046). Logistic regression showed that the stunting children have 30% higher risk of anemia than non-stunting children after adjustment for age, sex and school (OR = 1.30, 95% CI: 1.05-1.60). Conclusion: A significant geographic disparity and an association between anemia and stunting among specific groups of school-aged children in China was demonstrated. Consequently, eliminating the geographic disparity and ameliorating stunting might contribute to the improvement of Chinese children's anemia. Specific guidelines and interventions are needed, especially for adolescent girls and the groups with serious anemia burden.

In vitro and in vivo antitumor activities of three novel binuclear platinum(II) complexes with 4'-substituted-2,2':6',2″-terpyridine ligands.

Herein, we report the design and synthesis of three novel binuclear platinum(II) complexes, [Pt(tpbtpy)Cl][Pt(DMSO)Cl3] (tpbtpy-Pt), [Pt(dthbtpy)Cl][Pt(DMSO)Cl3]⋅CH3OH (dthbtpy-Pt), and [Pt(qlbtpy)Cl][Pt(DMSO)Cl3]⋅CH3OH (qlbtpy-Pt) with 4'-(3-thiophenecarboxaldehyde)-2,2':6',2″-terpyridine (tpbtpy), 4'-(3,5-bis (1,1-dimethylethyl)-2-hydroxy-benzaldehyde)-2,2':6',2″-terpyridine (dthbtpy) and 4'-(2-quinolinecarboxaldehyde)-2,2':6',2″-terpyridine (qlbtpy) as ligands, respectively. All three novel binuclear platinum(II) complexes tpbtpy-Pt, dthbtpy-Pt, and qlbtpy-Pt were characterized by single-crystal X-ray diffraction analysis, spectroscopic analysis (ESI-MS, IR, 1H NMR), and elemental analysis. Additionally, the cytotoxicity of tpbtpy-Pt, dthbtpy-Pt and qlbtpy-Pt was assessed with human non-small cell lung cancer cell line (NCIH460 cells), yielding IC50 values in the range of 0.35-12.09 µM with tpbtpy-Pt as the most potent and qlbtpy-Pt as the least potent complexes. Mechanistic studies indicated that tpbtpy-Pt and dthbtpy-Pt induced apoptosis through mitochondrial dysfunction and telomerase inhibition. In a NCIH460 xenograft model, when administered at 10.0 mg kg-1 every 2 days, tpbtpy-Pt was shown to significantly reduce tumor growth (tumor growth inhibition rate (IR) = 70.1%, p < 0.05). Therefore, tpbtpy-Pt is a promising Pt(II) complex for further translational studies and clinical evaluation as an antitumor agent.

Novel tacrine platinum(II) complexes display high anticancer activity via inhibition of telomerase activity, dysfunction of mitochondria, and activation of the p53 signaling pathway.

In this work, we designed and synthesized tacrine platinum(II) complexes [PtClL(DMSO)]⋅CH3OH (Pt1), [PtClL(DMP)] (Pt2), [PtClL(DPPTH)] (Pt3), [PtClL(PTH)] (Pt4), [PtClL(PIPTH)] (Pt5), [PtClL(PM)] (Pt6) and [PtClL(en)] (Pt7) with 4,4'-dimethyl-2,2'-bipyridine (DMP), 4,7-diphenyl-1,10-phenanthroline (DPPTH), 1,10-phenanthroline (PTH), 2-(1-pyrenecarboxaldehyde) imidazo [4,5-f]-[1,10] phenanthroline (PIPTH), 2-picolylamine (PM) and 1,2-ethylenediamine (en) as telomerase inhibitors and p53 activators. Biological evaluations demonstrated that Pt1Pt7 exhibited cytotoxic activity against the tested NCIH460, Hep-G2, SK-OV-3, SK-OV-3/DDP and MGC80-3 cancer cell lines, with Pt5 displaying the highest cytotoxicity. Pt5 exhibited an IC50 value of 0.13 ±â€¯0.16 µM against SK-OV-3/DDP cancer cells and significantly reduced tumor growth in a Hep-G2 xenograft mouse model (tumor growth inhibition (TGI) = 40.8%, p < 0.05) at a dose of 15.0 mg/kg. Interestingly, Pt1Pt7 displayed low cytotoxicity against normal HL-7702 cells. Mechanistic studies revealed that these compounds caused cell cycle arrest at the G2/M and S phases, and regulated the expression of CDK2, cyclin A, p21, p53 and p27. Further mechanistic studies showed that Pt5 induced SK-OV3/DDP cell apoptosis via dysfunction of mitochondria, inhibition of the telomerase activity by directly targeting the c-myc promoter, and activation of the p53 signaling pathway. Taken together, Pt5 has the potential to be further developed as a new antitumor drug.

Microstructures, mechanical and corrosion properties and biocompatibility of as extruded Mg-Mn-Zn-Nd alloys for biomedical applications.

Extruded Mg-1Mn-2Zn-xNd alloys (x=0.5, 1.0, 1.5 mass %) have been developed for their potential use as biomaterials. The extrusion on the alloys was performed at temperature of 623K with an extrusion ratio of 14.7 under an average extrusion speed of 4mm/s. The microstructure, mechanical property, corrosion behavior and biocompatibility of the extruded Mg-Mn-Zn-Nd alloys have been investigated in this study. The microstructure was examined using X-ray diffraction analysis and optical microscopy. The mechanical properties were determined from uniaxial tensile and compressive tests. The corrosion behavior was investigated using electrochemical measurement. The biocompatibility was evaluated using osteoblast-like SaOS2 cells. The experimental results indicate that all extruded Mg-1Mn-2Zn-xNd alloys are composed of both α phase of Mg and a compound of Mg7Zn3 with very fine microstructures, and show good ductility and much higher mechanical strength than that of cast pure Mg and natural bone. The tensile strength and elongation of the extruded alloys increase with an increase in neodymium content. Their compressive strength does not change significantly with an increase in neodymium content. The extruded alloys show good biocompatibility and much higher corrosion resistance than that of cast pure Mg. The extruded Mg-1Mn-2Zn-1.0Nd alloy shows a great potential for biomedical applications due to the combination of enhanced mechanical properties, high corrosion resistance and good biocompatibility.

Resilience and Psychosocial Function Among Mainland Chinese Parents of Children With Cancer: A Cross-sectional Survey.

BACKGROUND: Resilience is commonly used to refer to the capacity to resist negative psychological reactions when encountering aversive circumstances. However, clinicians generally define resilience as a lack of psychological distress or an adoption of positive attitude in response to a potentially traumatic event. Although resilience was initially considered to be a psychological variable, it has gradually become seen as a psychosocial indicator now used in clinical settings in the Western world but is still a relatively new topic in most Eastern countries. In this study, we aimed to extend our understandings of the psychological responses of a group of mainland Chinese parents upon being informed that their children were diagnosed with cancer, using resilience as a major indicator. OBJECTIVE: The aim of this study was to evaluate the level of resilience among mainland Chinese parents in response to knowing that their children were diagnosed with cancer and to examine the relationships between resilience and other psychosocial outcomes. METHODS: A descriptive and a cross-sectional survey design was used and involved a sample of 125 parents who visited a specialist cancer hospital in southeast China between September 2013 and February 2014. RESULTS: The participants reported lower level of resilience as compared with a control population in the Chinese community (P < .01). Resilience was negatively correlated with uncertainty in illness (P < .01) and depression (P < .01) and was positively correlated with social support (P < .01) and all other positive coping strategies subscales (P < .01). Parents from the high- resilience group reported better psychosocial functions than did those from the low-resilience group (P < .01). In addition, 6 influencing factors were identified and entered into the multiple linear regression equation of psychological resilience, which predicts 38.3% (adjusted R) of total variation in psychological resilience. CONCLUSION: A high level of resilience in parents of children diagnosed with cancer is associated with better psychosocial function in response to the traumatic event. IMPLICATIONS FOR CLINICAL PRACTICE: Additional attention should be given to those Mainland Chinese parents who demonstrated a low level of resilience in response to their child's diagnosis. This is particularly important because of the long and stressful process for cancer treatment. Clinicians should also provide targeted interventions to those parents to promote their psychological resilience.

Molecule counting with alkanethiol and DNA immobilized on gold microplates for extended gate FET.

Several molecule counting methods based on electrochemical characterization of alkanethiol and thiolated single-stranded oligonucleotide (HS-ssDNA) immobilized on gold microplates, which were used as extended gates of field effect transistors (FETs), have been investigated in this paper. The surface density of alkanethiol and DNA monolayers on gold microplates were quantitatively evaluated from the reductive desorption charge by using cyclic voltammetry (CV) and fast CV (FCV) methods in strong alkali solution. Typically, the surface density of 6-hydroxy-1-hexanethiol (6-HHT) was evaluated to be 4.639 molecules/nm(2), and the 28 base-pair dsDNA about 1.226-4.849 molecules/100 nm(2) on Au microplates after post-treatment with 6-HHT. The behaviors on surface potential and capacitance of different aminoalkanethiols on Au microplates were measured in 0.1 mol/L Na2SO4 and 10 mmol/L Tris-HCl (pH=7.4) solutions, indicating that the surface potential increases and the double-layer capacitance decreases with the length of carbon chain increased for the thiol monolayers, which obey a physics relationship for a capacitor. Comparably, a simple sensing method based on the electronic signals of biochemical reaction events on DNA immobilization and hybridization at the Au surface of the extended gate FET (EGFET) was developed, with which the surface density of the hybridized dsDNA on the gold surface of the EGFET was evaluated to be 1.36 molecules per 100 nm(2), showing that the EGFET is a promising sensing biochip for DNA molecule counting.

[Nonlinear spectral imaging of DNA specimens derived from tumor cells based on second harmonic generation].

Second harmonic generation (SHG) is a second-order nonlinear optical process that has symmetry constraints confining signal to regions lacking a center of symmetry. Using SHG microscopy, a variety of tissue structures have noninvasively been imaged by virtue of intrinsic signal generated by structured proteins such as collagen fibrils in connective tissues or the actomyosin lattice of muscle cells. In biochemistry and structure biology, the high-level structures of DNA and protein macro-molecules are similar in constructing mechanism, although DNAs consist of deoxynucleotides and proteins of amino acid residues. The principal purpose of present work is to detect the SHG signal from different DNA samples by spectral imaging technology based on two-photon excited fluorescence (TPEF) and SHG. These DNA samples include the solution of genomic DNA and extracted nuclei, and cultured living cells. Results show that we can obtain the SHG signal from solution of genomic DNA and extracted nuclei in routine condition, but nothing from cultured cell nuclei. After adding a little of absolute ethanol (less than 5% by volume) in culture medium, the SHG signal is detectable in the interested region of nuclei. The findings suggest that the interaction between ethanol and DNA in living cell gives rise to the shift of molecular conformation, and this shift changes some nonlinear optical properties of DNA molecules.

Fearful imagery induces hyperventilation and dyspnea in medically unexplained dyspnea.

BACKGROUND: Medically unexplained dyspnea refers to a condition characterized by a sensation of dyspnea and is typically applied to patients presenting with anxiety and hyperventilation without underlying cardiopulmonary pathology. We were interested to know how anxiety triggers hyperventilation and elicits subjective symptoms in those patients. Using an imagery paradigm, we investigated the role of fearful imagery in provoking hyperventilation and in eliciting symptoms, specifically dyspnea. METHODS: Forty patients with medically unexplained dyspnea and 40 normal subjects matched for age and gender were exposed to scripts and asked to imagine both fearful and restful scenarios, while end-tidal PCO(2) (PetCO(2)) and breathing frequency were recorded and subjective symptoms evaluated. The subject who had PetCO(2) falling more than 5 mmHg from baseline and persisting at this low level for more than 15 seconds in the imagination was regarded as a hyperventilation responder. RESULTS: In patients with medically unexplained dyspnea, imagination of fearful scenarios, being blocked in an elevator in particular, induced anxious feelings, and provoked a significant fall in PetCO(2) (P < 0.05). Breathing frequency tended to increase. Eighteen out of 40 patients were identified as hyperventilation responders compared to 5 out of 40 normal subjects (P < 0.01). The patients reported symptoms of dyspnea, palpitation or fast heart beat in the same fearful script imagery. Additionally, PetCO(2) fall was significantly correlated with the intensity of dyspnea and palpitation experienced during the mental imagery on one hand, and with anxiety symptoms on the other. CONCLUSIONS: Fearful imagery provokes hyperventilation and induces subjective symptoms of dyspnea and palpitation in patients with medically unexplained dyspnea.

[Medically unexplained dyspnea in children: a review of 34 cases].

OBJECTIVE: Medically unexplained dyspnea is common in adult and accounts for 14% patients complaining of dyspnea. Its occurrence in children is seldom recognized. In the present paper, 34 children with medically unexplained dyspnea (age 10 to 18 years) seen in Peking Union Medical College Hospital from 1996 to 2002 are reported. METHODS: The diagnosis of medically unexplained dyspnea was clinical: it was based on the presence of dyspnea and other complaints which cannot be explained by an organic disease. The patients answered Nijmegen questionnaire and state and trait anxiety (STAI), and performed hyperventilation provocation test. Twenty sessions of breathing therapy were applied and 13 out of 34 children were followed up after the therapy. RESULTS: Among the children, 75% started to have symptoms at the age of 13 to 16 years, though the age of first episode could be as early as 8 years. In most of the cases, the course was chronic clinically. In addition to marked dyspnea, their clinical profile included symptoms of hyperventilation i.e. blurred vision, dizziness, tingling, stiff fingers or arm. The symptoms of anxiety were less frequent in children and accordingly the level of anxiety evaluated by means of STAI was lower in children compared to adult patients. The precipitating psychological factors appeared to be related to middle school competition. Pressure from exams, reprimand from stern and unsympathetic teachers coupled with high parental expectation could be emotionally damaging to psychologically susceptible children. Thirteen patients were followed up after 2-3 months of breathing therapy with emphasis on abdominal breathing and slowing down of expiration. After therapy, the sum score of the Nijmegen Questionnaire was markedly decreased. Dyspnea and symptoms of hyperventilation were improved. The level of anxiety was minimally modified. CONCLUSION: The cases illustrated the need for careful diagnostic evaluation and treatment because of the high rate of chronicity of the disorder.

Medically unexplained dyspnea: psychophysiological characteristics and role of breathing therapy.

BACKGROUND: Medically unexplained dyspnea occurs commonly in medical settings and remains poorly understood. This study was conducted to investigate the psychophysiological characteristics of medically unexplained dyspnea and the efficacy of breathing retraining for these patients. METHODS: A group of patients with medically unexplained dyspnea were compared to patients with a variety of organic lung diseases and healthy subjects. In another group of patients, the influence of breathing therapy on complaints, anxiety, and breath-holding was evaluated for an average of 1.5 years. RESULTS: Patients with medically unexplained dyspnea reported more intense dyspnea than patients with a variety of organic lung diseases. Additionally, they were anxious and presented a broad range of symptoms in daily life and under challenge, for instance voluntary hyperventilation. More than one third of them qualified for panic disorder. They had shorter breath-holding time at rest, less increase in breath-holding time and higher chances of showing a "paradoxical" decrease of breath-holding time after hyperventilation. A combination of PaO2, forced expiratory volume in one second (FEV1), and anxiety measures distinguished them from organic dyspnea. Breathing retraining profoundly improved their symptoms and decreased the level of state and trait anxiety. Moreover, they better tolerated the voluntary hyperventilation and the symptoms induced were also markedly decreased after therapy. Breath-holding time was prolonged and PetCO2 in a representative group of patients increased. CONCLUSIONS: Patients with medically unexplained dyspnea appear to have the feature of a "psychosomatic" patient: an anxious patient with a wide variety of symptoms of different organ systems that do not have an organic basis. They can be distinguished from organic dyspnea using a small set of physiological and psychological measures. Breathing retraining turns out to be an effective therapy for those "difficult to treat patients".