[Analysis on the status quo of the awareness rate of core knowledge of cancer prevention and treatment and its influencing factors among residents in Liaoning Province in 2021]

Objective: To analyze the status quo of the knowledge and related factors of cancer prevention and treatment among residents in Liaoning Province in 2021. Methods: From August to November 2021, through network sampling method, 17 474 permanent residents aged 15-69 years in Liaoning Province were surveyed. The WeChat public account was used to collect information such as demographic characteristics and core knowledge of cancer prevention and treatment. The Chi-square test was used to compare the difference of the level of the cancer prevention and treatment knowledge among different groups. The multivariate logistic regression model was used to analyze the related factors. Results: Among the 17 474 subjects, 43.1% (7 528) were male and 58.7% (10 262) were urban residents. The overall awareness rate was 72.3%, and the awareness rate of cancer cognition, prevention, early diagnosis and treatment, cancer management and rehabilitation were 71.4%, 67.6%, 72.7%, 83.4% and 63.5%, respectively. The multivariate logistic regression model showed that the residents who were man (OR: 0.850, 95%CI: 0.781-0.925), in rural areas (OR: 0.753, 95%CI: 0.694-0.817), 55-59 years old (OR: 0.851, 95%CI: 0.751-0.963), quitters (OR: 0.721, 95%CI: 0.640-0.813) and smoker (OR: 0.724, 95%CI: 0.654-0.801) had lower awareness rates, while the residents who were 35-54 years old (OR: 1.312, 95%CI: 1.202-1.432), with an educational level of junior high school/senior high school/college degree or above (OR: 1.834-5.130, 95%CI: 1.575-6.047), technical personnel (OR: 1.592, 95%CI: 1.367-1.854), civil servant/institution staff (OR: 1.282, 95%CI: 1.094-1.503), enterprise/business/service staff (OR: 1.218, 95%CI: 1.071-1.385), retired (OR: 1.324, 95%CI: 1.114-1.573) and with family history of cancer (OR: 1.369, 95%CI: 1.266-1.481) had higher awareness rates. Conclusion: The level of the awareness of core knowledge of cancer prevention and treatment among residents in Liaoning Province has met the requirements of the Healthy China Action. Region, gender, education level, age, family history of cancer and smoking are relevant factors.

[Relation between corneal biomechanical alteration after small incision lenticule extraction and intraoperative cutting thickness]

Objective: To explore the rule of corneal biomechanical alteration with residual stromal thickness (RST) and percent tissue altered (PTA) after small incision lenticule extraction (SMILE) and to determine the factors influencing postoperative corneal biomechanical properties. Methods: In this retrospective study, a total of 184 patients (184 right eyes) who underwent SMILE in Tianjin Eye Hospital Refractive Surgery Center from January 2019 to January 2020 were enrolled. There were 83 males and 101 females with age of (24.6±5.8) years. Corneal biomechanical parameters, including DA ratio, stiffness parameter at the first applanation (SPA1) and integrated radius (IR), were measured with Corvis ST preoperatively and at 3 months postoperatively. The association between PTA, RST and the changes of DA ratio, SPA1 and IR was assessed by linear and nonlinear regression analyses. Stepwise multivariate regression analyses were conducted to explore the factors associated with postoperative corneal biomechanical parameters with age, sex, anterior mean keratometry, spherical equivalent, postoperative central corneal thickness (CCT) and preoperative corneal biomechanical parameters as covariates. Preoperative and postoperative data were compared using the paired t test. Correlations were determined by the Pearson or Spearman analysis. Results: The alterations at 3 months postoperatively of DA ratio, SPA1 and IR were 1.33 (30.0%), 28.05 (26.0%) and 2.56 (34.0%), respectively. The changes before and after surgery were statistically significant (t=35.52, -28.00, 36.95, P<0.01). The best-fit curve showed that the changes of DA ratio, SPA1 and IR increased with the decrease of RST or increase of PTA. When the RST was<280 μm or the PTA was>28%, the slope of the change of DA ratio curve was significantly increased. Multivariate regression models showed that the factors with the greatest influence on postoperative DA ratio, SPA1 and IR were preoperative DA ratio (Sβ=0.489, P<0.01), preoperative SPA1 (Sβ=0.483, P<0.01) and preoperative IR (Sβ=0.471, P<0.01), respectively. The CCT was the second factor that influenced postoperative DA ratio and SPA1 (Sβ=-0.238, P<0.01; Sβ=0.326, P<0.01). Conclusions: The changes of DA ratio, SPA1 and IR following SMILE increased with the decrease of RST or increase of PTA. With the RST<280 μm or the PTA>28%, the alteration of DA ratio significantly accelerated. Preoperative corneal biomechanical properties and postoperative CCT were main factors influencing corneal biomechanical properties after SMILE. (Chin J Ophthalmol, 2021, 57: 104-112).

Severity of Chest Imaging is Correlated with Risk of Acute Neuroimaging Findings among Patients with COVID-19

BACKGROUND AND PURPOSE

Severe respiratory distress in patients with COVID-19 has been associated with higher rate of neurologic manifestations. Our aim was to investigate whether the severity of chest imaging findings among patients with coronavirus disease 2019 (COVID-19) correlates with the risk of acute neuroimaging findings.

MATERIALS AND METHODS

This retrospective study included all patients with COVID-19 who received care at our hospital between March 3, 2020, and May 6, 2020, and underwent chest imaging within 10 days of neuroimaging. Chest radiographs were assessed using a previously validated automated neural network algorithm for COVID-19 (Pulmonary X-ray Severity score). Chest CTs were graded using a Chest CT Severity scoring system based on involvement of each lobe. Associations between chest imaging severity scores and acute neuroimaging findings were assessed using multivariable logistic regression.

RESULTS

Twenty-four of 93 patients (26%) included in the study had positive acute neuroimaging findings, including intracranial hemorrhage (n = 7), infarction (n = 7), leukoencephalopathy (n = 6), or a combination of findings (n = 4). The average length of hospitalization, prevalence of intensive care unit admission, and proportion of patients requiring intubation were significantly greater in patients with acute neuroimaging findings than in patients without them (P < .05 for all). Compared with patients without acute neuroimaging findings, patients with acute neuroimaging findings had significantly higher mean Pulmonary X-ray Severity scores (5.0 [SD, 2.9] versus 9.2 [SD, 3.4], P < .001) and mean Chest CT Severity scores (9.0 [SD, 5.1] versus 12.1 [SD, 5.0], P = .041). The pulmonary x-ray severity score was a significant predictor of acute neuroimaging findings in patients with COVID-19.

CONCLUSIONS

Patients with COVID-19 and acute neuroimaging findings had more severe findings on chest imaging on both radiographs and CT compared with patients with COVID-19 without acute neuroimaging findings. The severity of findings on chest radiography was a strong predictor of acute neuroimaging findings in patients with COVID-19.

Analysis of Stroke Detection during the COVID-19 Pandemic Using Natural Language Processing of Radiology Reports

BACKGROUND AND PURPOSE

The coronavirus disease 2019 (COVID-19) pandemic has led to decreases in neuroimaging volume. Our aim was to quantify the change in acute or subacute ischemic strokes detected on CT or MR imaging during the pandemic using natural language processing of radiology reports.

MATERIALS AND METHODS

We retrospectively analyzed 32,555 radiology reports from brain CTs and MRIs from a comprehensive stroke center, performed from March 1 to April 30 each year from 2017 to 2020, involving 20,414 unique patients. To detect acute or subacute ischemic stroke in free-text reports, we trained a random forest natural language processing classifier using 1987 randomly sampled radiology reports with manual annotation. Natural language processing classifier generalizability was evaluated using 1974 imaging reports from an external dataset.

RESULTS

The natural language processing classifier achieved a 5-fold cross-validation classification accuracy of 0.97 and an F1 score of 0.74, with a slight underestimation (-5%) of actual numbers of acute or subacute ischemic strokes in cross-validation. Importantly, cross-validation performance stratified by year was similar. Applying the classifier to the complete study cohort, we found an estimated 24% decrease in patients with acute or subacute ischemic strokes reported on CT or MR imaging from March to April 2020 compared with the average from those months in 2017-2019. Among patients with stroke-related order indications, the estimated proportion who underwent neuroimaging with acute or subacute ischemic stroke detection significantly increased from 16% during 2017-2019 to 21% in 2020 (P = .01). The natural language processing classifier performed worse on external data.

CONCLUSIONS

Acute or subacute ischemic stroke cases detected by neuroimaging decreased during the COVID-19 pandemic, though a higher proportion of studies ordered for stroke were positive for acute or subacute ischemic strokes. Natural language processing approaches can help automatically track acute or subacute ischemic stroke numbers for epidemiologic studies, though local classifier training is important due to radiologist reporting style differences.

Clinical and Neuroimaging Correlation in Patients with COVID-19

BACKGROUND AND PURPOSE

Coronavirus disease 2019 (COVID-19) is increasingly being recognized for its multiorgan involvement, including various neurological manifestations. We examined the frequency of acute intracranial abnormalities seen on CT and/or MR imaging in patients with COVID-19 and investigated possible associations between these findings and clinical parameters, including length of hospital stay, requirement for intubation, and development of acute kidney injury.

MATERIALS AND METHODS

This was a retrospective study performed at a large academic hospital in the United States. A total of 641 patients presented to our institution between March 3, 2020, and May 6, 2020, for treatment of coronavirus disease 2019, of whom, 150 underwent CT and/or MR imaging of the brain. CT and/or MR imaging examinations were evaluated for the presence of hemorrhage, infarction, and leukoencephalopathy. The frequency of these findings was correlated with clinical variables, including body mass index, length of hospital stay, requirement for intubation, and development of acute kidney injury as documented in the electronic medical record.

RESULTS

Of the 150 patients, 26 (17%) had abnormal CT and/or MR imaging findings, with hemorrhage in 11 of the patients (42%), infarction in 13 of the patients (50%), and leukoencephalopathy in 7 of the patients (27%). Significant associations were seen between abnormal CT/MR imaging findings and intensive care unit admission (P = .039), intubation (P = .004), and acute kidney injury (P = .030).

CONCLUSIONS

A spectrum of acute neuroimaging abnormalities was seen in our cohort of patients with coronavirus disease 2019, including hemorrhage, infarction, and leukoencephalopathy. Significant associations between abnormal neuroimaging studies and markers of disease severity (intensive care unit admission, intubation, and acute kidney injury) suggest that patients with severe forms of coronavirus disease 2019 may have higher rates of neuroimaging abnormalities.

Paraspinal Myositis in Patients with COVID-19 Infection

Myalgia is a previously reported symptom in patients with COVID-19 infection; however, the presence of paraspinal myositis has not been previously reported. We report MR imaging findings of the spine obtained in a cohort of 9 patients with COVID-19 infection who presented to our hospital between March 3, 2020 and May 6, 2020. We found that 7 of 9 COVID-19 patients (78%) who underwent MR imaging of the spine had MR imaging evidence of paraspinal myositis, characterized by intramuscular edema and/or enhancement. Five of these 7 patients had a prolonged hospital course (greater than 25 days). Our knowledge of the imaging manifestations of COVID-19 infection is expanding. It is important for clinicians>a to be aware of the relatively high frequency of paraspinal myositis in this small cohort of patients with COVID-19 infection.

Leukoencephalopathy Associated with Severe COVID-19 Infection: Sequela of Hypoxemia?

There is increasing evidence to suggest that complications of coronavirus disease 2019 (COVID-19) infection are not only limited to the pulmonary system but can also involve the central nervous system. Here, we report 6 critically ill patients with COVID-19 infection and neuroimaging findings of leukoencephalopathy. While these findings are nonspecific, we postulate that they may be a delayed response to the profound hypoxemia the patients experienced due to the infection. No abnormal enhancement, hemorrhage, or perfusion abnormalities were noted on MR imaging. In addition, Severe Acute Respiratory Syndrome coronavirus 2 was not detected in the CSF collected from the 2 patients who underwent lumbar puncture. Recognition of COVID-19-related leukoencephalopathy is important for appropriate clinical management, disposition, and prognosis.

Association between depression subtypes and response to repeated-dose intravenous ketamine

OBJECTIVE

About half or more of treatment-resistant depressed patients do not respond to ketamine, and few clinical predictors to gauge the most likely antidepressant response have been proposed. We explored whether depression subtypes are associated with response to ketamine.

METHOD

Ninety-seven participants with depression were administered six repeated-dose intravenous ketamine and assessed for depression (Montgomery-Åsberg Depression Rating Scale, MADRS), anxiety (Hamilton Anxiety Rating Scale, HAMA), and suicidal ideation (Beck Scale for Suicidal Ideation, SSI) at baseline, 24 h after each infusion, and 2 weeks after the whole treatment. Participants were classified by melancholic/anxious subtype. Individuals who met criteria for neither or both subtypes were classified separately, resulting in four mutually exclusive groups.

RESULTS

Patients with melancholic or melancholic-anxious features were less likely to respond (e.g., day 13, melancholic-anxious vs. anxious, OR 0.138, 95% CI 0.032-0.584, P = 0.007) or remit (e.g., day 26, melancholic vs. no subtype, OR 0.182, 95% CI 0.035-0.960, P = 0.045) and took longer to achieve response/remission than those with anxious or no subtype features. Faster HAMA score reductions were observed in patients with anxious or melancholic-anxious features, and faster SSI score reductions were observed among those with melancholic-anxious features.

CONCLUSION

Our study shows promising results for ketamine as a novel antidepressant preferentially for the treatment of non-melancholic or anxious depression.

[Advance study of rhinocerebralmucormycosis]

Mucormycosis is a rare, rapidly progressive life threatening opportunistic fungal infection, with rhinocerebral mucormycosis being the most common type. Rhinocerebral mucormycosis usually presents symptoms similar to sinusitis and orbital cellulitis during its early stage,which often leads to a misdiagnosis at the very beginning,and progresses rapidly to endophthalmitis,blindness,sclera perforation, eyeball atrophy, and even gets the central nervous system involved, thus leading to death. Mucormycosis is particularly common in patients with poor glycemic control, ketoacidosis and immunosuppression. The purpose of this review is to highlight the predisposing factors, infection pathway, pathogenesis, clinical presentations, diagnosis, and management of rhinocerebral mucormycosis, hence further promote the early diagnosis and immediate treatment of the disease. (Chin J Ophthalmol,2019,55:629-633).

Assessment of the Combined Effect of Plasma Exchange and Plasma Perfusion on Patients with Severe Hepatitis Awaiting Orthotopic Liver Transplantation

To determine if plasma exchange combined with plasma perfusion is a reliable and effective temporary liver support treatment for patients on the waiting list for OLT, we tested this method in 5 patients with end-stage and 3 patients with middle-stage severe hepatitis. Four patients were successfully controlled until a donor liver was available 4 to 13 days later. In contrast, the remaining 4 patients were not adequately controlled by this treatment and experienced aggravated disease progression, dying 3 to 8 days after treatment while still awaiting OLT. Of those 4 patients who received OLT, 2 patients died from multi-organ failure caused by hepatic failure, while the other 2 survived. These findings show that plasma exchange combined with plasma perfusion provides temporary support for some patients on the waiting list for OLT. The ability of patients to successfully bridge to OLT is closely associated with the degree of liver failure, complications, multi-organ failure, and the length of the waiting period for a donor liver.

Crucial roles of the CHRNB3-CHRNA6 gene cluster on chromosome 8 in nicotine dependence: update and subjects for future research

Cigarette smoking is a leading cause of preventable death throughout the world. Nicotine, the primary addictive compound in tobacco, plays a vital role in the initiation and maintenance of its use. Nicotine exerts its pharmacological roles through nicotinic acetylcholine receptors (nAChRs), which are ligand-gated ion channels consisting of five membrane-spanning subunits. Besides the CHRNA4, CHRNB2 and CHRNA5/A3/B4 cluster on chromosome 15, which has been investigated intensively, recent evidence from both genome-wide association studies and candidate gene-based association studies has revealed the crucial roles of the CHRNB3-CHRNA6 gene cluster on chromosome 8 in nicotine dependence (ND). These studies demonstrate two distinct loci within this region. The first one is tagged by rs13277254, upstream of the CHRNB3 gene, and the other is tagged by rs4952, a coding single nucleotide polymorphism in exon 5 of that gene. Functional studies by genetic manipulation in mice have shown that α6*-nAChRs, located in the ventral tegmental area (VTA), are of great importance in controlling nicotine self-administration. However, when the α6 subunit is selectively re-expressed in the VTA of the α6(-/-) mouse by a lentiviral vector, the reinforcing property of nicotine is restored. To further determine the role of α6*-nAChRs in the process of nicotine-induced reward and withdrawal, genetic knock-in strains have been examined, which showed that replacement of Leu with Ser in the 9' residue in the M2 domain of α6 produces nicotine-hypersensitive mice (α6 L9'S) with enhanced dopamine release. Moreover, nicotine-induced upregulation may be another ingredient in the pathology of nicotine addiction although the effect of chronic nicotine exposure on the expression of α6-containing receptors is controversial. To gain a better understanding of the pathological processes underlying ND and ND-related behaviors and to promote the development of effective smoking cessation therapies, we here present the most recent studies concerning the genetic effects of the CHRNB3-CHRNA6 gene cluster in ND.

Gray Matter Growth Is Accompanied by Increasing Blood Flow and Decreasing Apparent Diffusion Coefficient during Childhood

BACKGROUND AND PURPOSE

Normal values of gray matter volume, cerebral blood flow, and water diffusion have not been established for healthy children. We sought to determine reference values for age-dependent changes of these parameters in healthy children.

MATERIALS AND METHODS

We retrospectively reviewed MR imaging data from 100 healthy children. Using an atlas-based approach, age-related normal values for regional CBF, apparent diffusion coefficient, and volume were determined for the cerebral cortex, hippocampus, thalamus, caudate, putamen, globus pallidus, amygdala, and nucleus accumbens.

RESULTS

All gray matter structures grew rapidly before the age of 10 years and then plateaued or slightly declined thereafter. The ADC of all structures decreased with age, with the most rapid changes occurring prior to the age of 5 years. With the exception of the globus pallidus, CBF increased rather linearly with age.

CONCLUSIONS

Normal brain gray matter is characterized by rapid early volume growth and increasing CBF with concomitantly decreasing ADC. The extracted reference data that combine CBF and ADC parameters during brain growth may provide a useful resource when assessing pathologic changes in children.

Impact of EGR on the surface functional groups of diesel engine particles based on NEXAFS

The thermal, dilution and chemical effects of EGR result in relatively significant changes in the formation environment, in the physical and chemical reactions of particles and in the functional groups of the matter that constitutes the particles.

The significant association of Taq1A genotypes in DRD2/ANKK1 with smoking cessation in a large-scale meta-analysis of Caucasian populations

Although a number of studies have analyzed the relation between the DRD2/ANKK1 gene Taq1A polymorphism and smoking cessation, the results remain controversial. The primary objective of the present study was to determine whether this variant indeed has any effect on smoking cessation. The A1-dominant model that considers A1/* (*=A1 or A2) and A2/A2 as two genotypes and compares their frequencies in current and former smokers was applied. A total of 22 studies with 11,075 subjects were included in the meta-analyses. Considering the potential influence of between-study heterogeneity, we conducted stratified meta-analyses with the Comprehensive Meta-Analysis statistical software (version 2.0). Results based on either cross-sectional or longitudinal studies consistently showed a statistically significant association between Taq1A A1/* genotypes and smoking cessation. Further, a more significant association of the variant with smoking cessation was detected when both types of studies were combined. However, there was marginal evidence of heterogeneity among studies (I(2)=33.9%; P=0.06). By excluding other ethnicities and subjects with cancer, the meta-analysis on the basis of 9487 Caucasians demonstrated that Taq1A A1/* genotypes indeed were significantly associated with smoking cessation under both the fixed- and random-effects models (pooled OR 1.22; 95% CI 1.11-1.34; P=3.9 × 10(-5) for both models). No evidence of between-study heterogeneity or publication bias was observed. Thus, we conclude that the polymorphism of Taq1A has an important role in the process of abstaining from smoking, and smokers carrying A2/A2 genotype have a higher likelihood of smoking cessation than those who carry A1/A1 or A1/A2.

δ34S and δ18O of dissolved sulfate as biotic tracer of biogeochemical influences on arsenic mobilization in groundwater in the Hetao Plain, Inner Mongolia, China

Environmental isotopology of sulfur and oxygen of dissolved sulfate in groundwater was conducted in the Hetao Plain, northwestern China, aiming to better understand the processes controlling arsenic mobilization in arsenic-rich aqueous systems. A total of 22 groundwater samples were collected from domestic wells in the Hetao Plain. Arsenic concentrations ranged from 11.0 to 388 μg/L. The δ(34)S-SO4 and δ(18)O-SO4 values of dissolved sulfate covered a range from +1.48 to +22.4‰ and +8.17‰ to +14.8‰ in groundwater, respectively. The wide range of δ(34)S-SO4 values reflected either an input of different sources of sulfate, such as gypsum dissolution and fertilizer application, or a modification from biogeochemical process of bacterial sulfate reduction. The positive correlation between δ(34)S-SO4 and arsenic concentrations suggested that bacteria mediated processes played an important role in the mobilization of arsenic. The δ(18)O-SO4 values correlated non-linearly with δ(34)S-SO4, but within a relatively narrow range (+8.17 to +14.8‰), implying that complexities inherent in the sulfate-oxygen (O-SO4(2-)) origins, for instance, water-derived oxygen (O-H2O), molecular oxygen (O-O2) and isotope exchanging with dissolved oxides, are accounted for oxygen isotope composition of dissolved sulfate in groundwater in the Hetao Plain.

Gestational nicotine exposure modifies myelin gene expression in the brains of adolescent rats with sex differences

Myelination defects in the central nervous system (CNS) are associated with various psychiatric disorders, including drug addiction. As these disorders are often observed in individuals prenatally exposed to cigarette smoking, we tested the hypothesis that such exposure impairs central myelination in adolescence, an important period of brain development and the peak age of onset of psychiatric disorders. Pregnant Sprague Dawley rats were treated with nicotine (3 mg kg(-1) per day; gestational nicotine (GN)) or gestational saline via osmotic mini pumps from gestational days 4-18. Both male and female offsprings were killed on postnatal day 35 or 36, and three limbic brain regions, the prefrontal cortex (PFC), caudate putamen and nucleus accumbens, were removed for measurement of gene expression and determination of morphological changes using quantitative real-time PCR (qRT-PCR) array, western blotting and immunohistochemical staining. GN altered myelin gene expression at both the mRNA and protein levels, with striking sex differences. Aberrant expression of myelin-related transcription and trophic factors was seen in GN animals, which correlated highly with the alterations in the myelin gene expression. These correlations suggest that these factors contribute to GN-induced alterations in myelin gene expression and also indicate abnormal function of oligodendrocytes (OLGs), the myelin-producing cells in the CNS. It is unlikely that these changes are attributable solely to an alteration in the number of OLGs, as the cell number was changed only in the PFC of GN males. Together, our findings suggest that abnormal brain myelination underlies various psychiatric disorders and drug abuse associated with prenatal exposure to cigarette smoke.

MicroRNAs in addiction: adaptation's middlemen?

A central question in addiction is how drug-induced changes in synaptic signaling are converted into long-term neuroadaptations. Emerging evidence reveals that microRNAs (miRNAs) have a distinct role in this process through rapid response to cellular signals and dynamic regulation of local mRNA transcripts. Because each miRNA can target hundreds of mRNAs, relative changes in the expression of miRNAs can greatly impact cellular responsiveness, synaptic plasticity and transcriptional events. These diverse consequences of miRNA action occur through coordination with genes implicated in addictions, the most compelling of these being the neurotrophin BDNF, the transcription factor cAMP-responsive element-binding protein (CREB) and the DNA-binding methyl CpG binding protein 2 (MeCP2). In this study, we review the recent progress in the understanding of miRNAs in general mechanisms of plasticity and neuroadaptation and then focus on specific examples of miRNA regulation in the context of addiction. We conclude that miRNA-mediated gene regulation is a conserved means of converting environmental signals into neuronal response, which holds significant implications for addiction and other psychiatric illnesses.

A solid-mounted resonator-oscillator-based 4.596 GHz frequency synthesis

This paper describes a 4.596 GHz frequency synthesis based on a 2.1 GHz solid mounted resonator (SMR) voltage-controlled oscillator (VCO). The SMR oscillator presents a chip size lower than 2 mm(2), a power consumption of 18.2 mW, and exhibits a phase noise of -89 dBc/Hz and -131 dBc/Hz at 2 kHz and 100 kHz offset frequencies, respectively. The VCO temperature-frequency dependence is measured to be -14 ppm∕°C over a range of -20°C to 60°C. From this source, a low noise frequency synthesizer is developed to generate a 4.596 GHz signal (half of the Cs atom hyperfine transition frequency) with a phase noise of -81 dBc/Hz and -120 dBc/Hz at 2 kHz and 100 kHz from the carrier. The frequency synthesis output is used as a local oscillator in a Cs vapor microcell-based compact atomic clock. Preliminary results are reported and discussed. To the authors knowledge, this is the first development of a SMR-oscillator-based frequency synthesizer for miniature atomic clocks applications.

Bitter taste receptor gene polymorphisms are an important factor in the development of nicotine dependence in African Americans

CONTEXT

Bitter sensitivity varies among individuals and ethnic groups partly due to polymorphisms in taste receptor genes (TAS2Rs). Although previous psychophysical studies suggest that taste status plays a role in nicotine dependence (ND), genetic evidence is lacking.

OBJECTIVES

To determine whether single nucleotide polymorphisms (SNPs) in TAS2R16 and TAS2R38 are associated with ND and if the effects differ by sex and ethnicity.

DESIGN, SETTING, AND PARTICIPANTS

2037 individuals from 602 nuclear families of African American (AA) or European American (EA) origin were recruited from the US mid-south states during 1999-2004.

MAIN OUTCOME MEASURES

ND was assessed by three measures: indexed Smoking Quantity (SQ), Heaviness of Smoking Index (HSI), and the Fagerström Test for Nicotine Dependence (FTND). Peripheral blood samples were obtained for DNA extraction and genotyping.

RESULTS

The TAS2R38 taster haplotype PAV was inversely associated (p = 0.0165), and the non-taster haplotype AVI was positively associated (p = 0.0120), with SQ in AA smokers. The non-taster haplotype was positively associated with all ND measures in AA female smokers (p = 0.01 approximately 0.003). No significant associations were observed in the EA sample.

CONCLUSIONS

TAS2R38 polymorphisms are an important factor in determining ND in AAs. Heightened oral sensitivity confers protection against ND. Conversely, decreased sensitivity represents a risk factor for ND, especially in AA females. Together, our findings suggest that taster status plays a role in governing the development of ND and may represent a way to identify individuals at risk for developing ND, particularly in AA smokers.

Beta-arrestins 1 and 2 are associated with nicotine dependence in European American smokers

On the basis of our previous identified linkage regions for nicotine dependence (ND), we selected seven and four single nucleotide polymorphisms (SNPs) in the beta-arrestins 1 (ARRB1) and 2 (ARRB2), respectively, to determine the associations of the two genes with ND in a total of 2037 subjects from 602 nuclear families of European American (EA) and African American (AA) origin. ND was assessed by Smoking Quantity (SQ), the Heaviness of Smoking Index (HSI) and the Fagerström Test for ND (FTND) score. Individual SNP analysis indicated that SNPs rs472112 within ARRB1 and rs4790694 within ARRB2 in the EA sample was significantly associated with HSI and FTND score, and the association of rs4790694 for ARRB2 remained significant after correction for multiple testing. Haplotype analysis revealed that haplotype C-G-C-G-G-T within ARRB1 at a frequency of 20%, formed by SNPs rs528833, rs1320709, rs480174, rs5786130, rs611908 and rs472112, was positively associated with HSI and FTND in EAs. We also found a haplotype within ARRB2, C-C-A-T at a frequency of 10.7%, formed by SNPs rs3786047, rs4522461, rs1045280 and rs4790694, that showed a significant positive association with HSI and FTND in the EA sample. No significant associations for either individual SNPs or major haplotype of both ARRB1 and ARRB2 were found in the AA sample. Further, the strength of these associations increased after removing the SQ component from HSI and FTND scores in both the EA and AA samples, suggesting that ARRB1 and ARRB2 play an important role in biological processes involved in the regulation of smoking urgency (that is time to smoke first cigarette). In summary, our results provide the first evidence of a significant association for ARRB1 and ARRB2 variants with ND in an EA sample.

Genome-wide linkage scan for nicotine dependence in European Americans and its converging results with African Americans in the Mid-South Tobacco Family sample

Previously, we reported a genome-wide scan for nicotine dependence (ND) in the African American (AA) sample of the Mid-South Tobacco Family (MSTF) cohort. In this study, we conducted a genome-wide scan in 629 individuals representing 200 nuclear families of European American (EA) origin of the MSTF cohort with the goals of identifying vulnerability loci for ND in the EAs and determining converging regions across the ethnic groups. We examined 385 autosomal microsatellite markers for ND, which was assessed by smoking quantity (SQ), the Heaviness of Smoking Index (HSI) and the Fagerström test for ND (FTND). After performing linkage analyses using various methods implemented in the GENEHUNTER and SAGE programs, we found eight regions on chromosomes 2, 4, 9-12, 17 and 18 that met the criteria for suggestive linkage to at least one ND measure in the EA sample. Of these, the region on chromosome 4 at 43 cM showed suggestive linkage to indexed SQ, the HSI and the FTND, and the region on chromosome 9 at 24 cM showed suggestive linkage to the HSI and the FTND. To increase detection power, we analyzed a combined AA and EA sample using age, gender and ethnicity as covariates and found that the region on chromosome 12 near marker D12S372 showed significant linkage to SQ. Additionally, we found six regions on chromosomes 9-11, 13 and 18 that showed suggestive linkage to at least one ND measure in the combined sample. When we compared the linkage peaks detected for ND among the two samples and a combined sample, we found that four regions on chromosomes 9 (two regions), 11 and 18 overlapped. On the other hand, we identified five regions on chromosomes 2, 4, 10, 12 and 17 that showed linkage to ND only in the EA sample, and two regions on chromosomes 10 and 13 that showed linkage to ND only in the AA sample. For those linkages identified in only one sample, we found that the combined analysis of AA plus EA samples actually decreased the linkage signal. This indicates that some chromosomal regions may be more homogenous than others across the ethnic samples. All regions except for the one on chromosome 12 have been detected at nominally significant levels in other studies, providing independent replication of ND loci in different populations.

Strain- and region-specific gene expression profiles in mouse brain in response to chronic nicotine treatment

A pathway-focused complementary DNA microarray and gene ontology analysis were used to investigate gene expression profiles in the amygdala, hippocampus, nucleus accumbens, prefrontal cortex (PFC) and ventral tegmental area of C3H/HeJ and C57BL/6J mice receiving nicotine in drinking water (100 mug/ml in 2% saccharin for 2 weeks). A balanced experimental design and rigorous statistical analysis have led to the identification of 3.5-22.1% and 4.1-14.3% of the 638 sequence-verified genes as significantly modulated in the aforementioned brain regions of the C3H/HeJ and C57BL/6J strains, respectively. Comparisons of differential expression among brain tissues showed that only a small number of genes were altered in multiple brain regions, suggesting presence of a brain region-specific transcriptional response to nicotine. Subsequent principal component analysis and Expression Analysis Systematic Explorer analysis showed significant enrichment of biological processes both in C3H/HeJ and C57BL/6J mice, i.e. cell cycle/proliferation, organogenesis and transmission of nerve impulse. Finally, we verified the observed changes in expression using real-time reverse transcriptase polymerase chain reaction for six representative genes in the PFC region, providing an independent replication of our microarray results. Together, this report represents the first comprehensive gene expression profiling investigation of the changes caused by nicotine in brain tissues of the two mouse strains known to exhibit differential behavioral and physiological responses to nicotine.

Linkage and association studies in African- and Caucasian-American populations demonstrate that SHC3 is a novel susceptibility locus for nicotine dependence

Our previous linkage study demonstrated that the 9q22-q23 chromosome region showed a 'suggestive' linkage to nicotine dependence (ND) in the Framingham Heart Study population. In this study, we provide further evidence for the linkage of this region to ND in an independent sample. Within this region, the gene encoding Src homology 2 domain-containing transforming protein C3 (SHC3) represents a plausible candidate for association with ND, assessed by smoking quantity (SQ), the Heaviness of Smoking Index (HSI) and the Fagerström Test for ND (FTND). We utilized 11 single-nucleotide polymorphisms within SHC3 to examine the association with ND in 602 nuclear families of either African-American (AA) or European-American (EA) origin. Individual SNP-based analysis indicated three SNPs for AAs and one for EAs were significantly associated with at least one ND measure. Haplotype analysis revealed that the haplotypes A-C-T-A-T-A of rs12519-rs3750399-rs4877042-rs2297313-rs1547696-rs1331188, with a frequency of 27.8 and 17.6%, and C-T-A-G-T of rs3750399-rs4877042-rs2297313-rs3818668-rs1547696, at a frequency of 44.7 and 30.6% in the AA and Combined samples, respectively, were significantly inversely associated with the ND measures. In the EA sample, another haplotype with a frequency of 10.6%, A-G-T-G of rs1331188-rs1556384-rs4534195-rs1411836, showed a significant inverse association with ND measures. These associations remained significant after Bonferroni correction. We further demonstrated the SHC3 contributed 40.1-59.2% (depending on the ND measures) of the linkage signals detected on chromosome 9. As further support, we found that nicotine administered through infusion increased the Shc3 mRNA level by 60% in the rat striatum, and decreased it by 22% in the nucleus accumbens (NA). At the protein level, Shc3 was decreased by 38.0% in the NA and showed no change in the striatum. Together, these findings strongly implicate SHC3 in the etiology of ND, which represents an important biological candidate for further investigation.

Mapping and verification of susceptibility loci for smoking quantity using permutation linkage analysis

Nicotine dependence is the most prevalent form of drug addiction in the US and throughout the world. Epidemiological studies demonstrate that genetics accounts for at least 50% of the liability to nicotine dependence. However, there have been very limited linkage studies providing convincing evidence of susceptibility genomic loci for this disorder. In this study, we conducted genome-wide permutation linkage analyses on the smoking data collected between 1970 and 1972 of the Framingham Heart Study (FHS) to account for the abnormality associated with the smoking quantity (defined as the number of cigarettes smoked per day). We used empirical thresholds obtained from permutation tests to determine the significance of each genomic region. The variance component method implemented in SOLAR was used for the analysis. Under the empirical genome-wide thresholds determined specifically for the FHS smoking data, we found two highly or near-highly significant linkages of nicotine dependence on chromosomes 1 and 4 (P=0.001) and eight significant linkages on chromosomes 3, 7, 8, 9, 11, 16, 17, and 20 (P<0.05). These findings strongly indicate that some of these regions may harbor susceptibility loci for nicotine dependence. Further analysis of these positive regions by fine mapping and/or association analysis is warranted. To our knowledge, this study presents the most convincing linkage evidence for nicotine dependence in the field.

Regulation of Homer and group I metabotropic glutamate receptors by nicotine

The present study focuses on the nicotine-induced modulation of mRNA and protein expression of a number of genes involved in glutamatergic synaptic transmission in rat brain over different time periods of exposure. A subchronic (3 days) but not the chronic (7 or 14 days) administration of nicotine resulted in the up-regulation of Homer2a/b mRNA in the amygdala while in the ventral tegmental area (VTA) no change in expression of either Homer2a/b or Homer1b/c was observed. Although the increase in Homer2a/b mRNA was not translated into the protein level in the amygdala, a slight but significant up-regulation of Homer1b/c protein was observed in the same region at day 3. Both Homer forms were up-regulated at the protein level in the VTA at day 3. In the nucleus accumbens, 14 days of nicotine treatment up-regulated mRNA of Homer2b/c by 68.2% (P < 0.05), while the short form Homer1a gene was down-regulated by 65.0% at day 3 (P < 0.05). In regard to other components of the glutamatergic signalling, we identified an acute and intermittent increase in the mRNA and protein levels of mGluR1 and mGluR5 in the amygdala. In the VTA, however, the effects of nicotine on mGluR mRNA expression were long-lasting but rather specific to mGluR1. Nevertheless, mGluR1 protein levels in the VTA area were up-regulated only at day 3, as in the amygdala. These data provide further evidence for the involvement of nicotine in the glutamatergic neuronal synaptic activity in vivo, suggesting a role for the newly identified Homer proteins in this paradigm.

Progress in searching for susceptibility loci and genes for smoking-related behaviour

Smoking behaviour is influenced by both genetic and environmental factors. Many years of twin and adoption studies have demonstrated that heritability is at least 50% responsible for both smoking initiation and smoking persistence. Furthermore, the extent, to which genetic and environmental factors contribute to smoking behaviour, is significantly different in men and women. Linkage analyses from several independent studies provide evidences for suggested linkage of smoking behaviour to chromosomes 1, 2, 4, 5, 6, 9, 10, 11, 14, 17, 18 and 21. However, almost none of these loci have been replicated yet. Furthermore, numerous population-based association studies have been performed to examine the effects of a number of candidate genes, such as cytochrome P450, dopamine receptor (DR) and transporter, serotonin transporter and nicotinic acetylcholine receptor, on smoking behaviour. However, many of these reports have not yet received independent confirmation. Of these candidate genes, the D2 dopamine receptor (DRD2) gene has been extensively studied. Meta-analysis of 12 reported studies showed a significantly higher prevalence of the DRD2 TaqI A1 allele in smokers than that in non-smokers (p < 0.0001; pooled OR = 1.50; 95% CI = 1.33-1.70). For other candidate genes, insufficient published studies are available to allow a meta-analysis to be performed, or meta-analysis showed no significant difference between smokers and non-smokers. More studies are necessary to determine whether these genes play a significant role in smoking behaviour.

Comparison of marker intervals and number of sib pairs used for linkage analysis on simulated nuclear family data

Using a two-stage global scan design, we analyzed general population replicates 1 and 42 of the Genetic Analysis Workshop (GAW) 12 simulated data set using three methods: revisited Haseman-Elston (HER), maximum likelihood variance estimation (ML), and variance components (VC). Three marker densities, 5-, 10-, and 15-cM intervals, were examined in the first-stage scan. We found that the 10-cM interval appears to be the most cost-effective approach in genotyping without sacrificing power when using a first stage significance level of 0.01. Subsequently, we performed the second-stage scan at 1-cM intervals for those putative positive regions identified in the first-stage scan at a significance level of 0.01. We also compared the power to detect linkage using different numbers of sib pairs for a genome-wide scan at a 10-cM interval and found that power decreases nonlinearly as the number of sib pairs decreases.

Expression of delta opioid receptors and transcripts by splenic T cells

Delta opioid receptors (DORs) and preproenkephalin-A-derived opiate peptides are expressed by mononuclear cells in various lymphoid organs. DOR ligands modulate a variety of immune functions, such as T-cell proliferation, calcium mobilization, and cytokine production. Recently, quiescent T cells were found to express low levels of DOR transcripts, which increased due to the following: cell culture of unstimulated murine splenocytes (depending on cell density); cross-linking the T-cell receptor (TCR) with anti-CD3-epsilon; and a single in vivo exposure to staphylococcal enterotoxin B (SEB). Enhanced expression of DOR mRNA was mediated transcriptionally. Moreover, PMA + ionomycin, which mimic the proliferative signal of anti-CD3, inhibited the expression of DOR mRNA. Using semiquantitative immunofluorescence to detect DORs, SEB was found to increase the fraction of T cells that expressed DOR and to enhance the relative level of DOR expression per T cell. Previous studies have shown that DOR agonists inhibited the anti-CD3-stimulated production of interleukin-2 and T-cell proliferation. Therefore, the enhanced expression of DORs by activated T cells may be capable of downregulating the T-cell activation program.

Cloned neuropeptide Y (NPY) Y1 and pancreatic polypeptide Y4 receptors expressed in Chinese hamster ovary cells show considerable agonist-driven internalization, in contrast to the NPY Y2 receptor

Guinea-pig neuropeptide Y1 and rat pancreatic polypeptide Y4 receptors expressed in Chinese hamster ovary cells were internalized rapidly upon attachment of selective peptide agonists. The Y1 and Y2, but not the Y4, receptor also internalized the nonselective neuropeptide Y receptor agonist, human/rat neuropeptide Y. The internalization of guinea-pig neuropeptide Y2 receptor expressed in Chinese hamster ovary cells was small at 37 degrees C, and essentially absent at or below 15 degrees C, possibly in connection to the large molecular size of the receptor-ligand complexes (up to 400 kDa for the internalized fraction). The rate of intake was strongly temperature dependent, with essentially no internalization at 6 degrees C for any receptor. Internalized receptors were largely associated with light, endosome-like particulates. Sucrose dose-dependently decreased the internalization rate for all receptors, while affecting ligand attachment to cell membrane sites much less. Internalization of the Y1 and the Y4 receptors could be blocked, and that of the Y2 receptor significantly inhibited, by phenylarsine oxide, which also unmasked spare cell-surface receptors especially abundant for the Y2 subtype. The restoration of Y1 and Y4 receptors after agonist peptide pretreatment was decreased significantly by cycloheximide and monensin. Thus, in Chinese hamster ovary cells the Y1 and Y4 receptors have much larger subcellular dynamics than the Y2 receptor. This differential could also hold in organismic systems, and is comparable with the known differences in internalization of angiotensin, bradykinin, somatostatin and opioid receptor subtypes.

Hypothalamic orexin-A binding sites are downregulated by chronic nicotine treatment in the rat

Chronic nicotine treatment (4 mg/kg per day; 14 days) significantly reduced the affinity and density of orexin-A binding sites in the anterior hypothalamus of rat brain. There was a significantly lower sensitivity of orexin-A binding to orexin peptides, to the related secretin and pituitary adenylate cyclase activating peptide, and to unrelated neuropeptide Y (NPY). This change correlated with selective downregulation of a fraction of hypothalamic NPY Y(1) receptors. In previous studies, we have demonstrated an increase in the levels of orexin-A peptide and NPY in discrete hypothalamic areas upon nicotine treatment. This finding contradicts an expected increase in the production of these orexigenic peptides in a model where an inverse relationship is observed between food consumption and nicotine treatment. This study provides a possible explanation to this inconsistency in that a decrease in affinity of orexin-A binding could reduce neural orexin signaling, which may contribute to decreased food intake observed in smokers and animals chronically treated with nicotine.

Nicotine up-regulates expression of orexin and its receptors in rat brain

Orexins are two recently discovered neuropeptides that can stimulate food intake. As the chronic use of tobacco typically leads to a reduction in body weight, it is of interest to determine whether nicotine, the major biologically active tobacco ingredient, has an effect on orexin metabolism in the brain. Using a semiquantitative RT-PCR technique, the levels of messenger RNA (mRNA) for prepro-orexin, orexin A (OX1-R) and orexin B (OX2-R) receptors were 20-50% higher in rats receiving nicotine for 14 days at the level of 2-4 mg/kg day compared with rats receiving saline solvent alone. In animals treated with nicotine at 4 mg/kg x day, the expression levels of mRNA for prepro-orexin, OX1-R, and OX2-R were significantly higher compared with those in either the free-feeding control or pair-fed saline control rats. RIA data indicated that both orexin A and orexin B peptide levels were significantly elevated (45-54%; P < 0.01) in the dorsomedial nucleus (DMH) of the nicotine-treated rats compared with either solvent-only or pair-fed controls. Additionally, orexin B was significantly elevated (83%; P < 0.01), over levels in both types of the control animals, in the paraventricular nucleus (PVN) region. In summary, we demonstrated that an inverse association between nicotine and food intake as well as body weight held with doses comparable to those consumed by average human smokers. Moreover, our data indicated that chronic exposure to nicotine can induce a long-term increase in the expression levels of prepro-orexin and their receptor mRNA in the rat hypothalamus and in the levels of orexin A in the DMH and orexin B in the DMH and PVN among the six hypothalamic regions that we examined.

Regulation of feeding-associated peptides and receptors by nicotine

Although numerous epidemiological studies have provided convincing evidence for the inverse association between tobacco smoking and body weight, the molecular mechanisms underlying this relationship are not well-understood. Nicotine, as a potent secretagogue, could be expected to influence the levels and expression of many classes of neurotransmitters, as well as of cell-membrane constituents linked to neurotransmission, including signal transducers and related effectors. A potentially major group of candidate molecules that could be involved in feeding-related actions of nicotine are the numerous neuropeptides and peptide hormones shown in the past two decades to regulate food intake and energy expenditure. These could include neuropeptide Y (NPY), orexins, leptins, and uncoupling proteins (UCPs). Some of these peptides were already shown to respond to nicotine treatment in terms of regulation of levels and of activity at the level of cell-membrane receptors. The primary objective of this review is to summarize our current understanding of the regulatory effects of nicotine on the food intake and energy expenditure as related to the expression levels of leptin, NPY, orexin, uncoupling proteins, and of NPY and orexin receptors.

Sensitivity of orexin-A binding to phospholipase C inhibitors, neuropeptide Y, and secretin

The binding of [(125)I] orexin-A (Ox-A) to particulates from Chinese hamster ovary (CHO) cells expressing the cloned orexin-A receptor, or from rat forebrain areas, was sensitive to blockers of phosphatidylinositol-specific phospholipase C (PtdIns-PLC) U-73122 and ET-18-OCH(3), little affected by phospholipase A(2) inhibitor quinacrine, and not sensitive to D609, a xanthate inhibitor of phosphatidylcholine-selective PLC. Interaction of the receptor with a PtdIns-PLC was further indicated by a large sensitivity of the binding to Ca(2+). Up to 50% of the binding was sensitive to the G-protein nucleotide site agonist GTP-gamma-S. Ligand attachment to the orexin-A receptor thus depends on an association with both PtdIns-PLC and G-protein alpha-subunits. In all paradigms examined, the binding of [(125)I]orexin-A was competed by human/rat neuropeptide Y (hNPY) and porcine secretin with a potency similar to orexin-A (IC(50) range 30-100 nM). The rank order of potency for NPY-related peptides was hNPY > porcine peptide YY (pPYY) > (Leu(31), Pro(34)) human PYY > human PYY(3-36) > hNPY free acid > human pancreatic polypeptide. Among secretin-related peptides, the rank order of potency was porcine secretin > or = orexin-A > human pituitary adenylate cyclase-activating peptide > orexin-B > porcine vasoactive intestinal peptide. Among opioid peptides, rat beta-endorphin and camel delta-endorphin were much less active than NPY and secretin, and two enkephalins were inactive at 1 microM. In view of high abundance of NPY in forebrain, the above cross-reactivity could indicate a significant contribution of NPY to signaling via orexin-A receptors.

Nicotine administration enhances NPY expression in the rat hypothalamus

Epidemiological studies have shown an inverse relationship between cigarette smoking and body weight. In rodents, a negative correlation between nicotine and body weight has been reported, but this observation was largely derived from studies where relatively high doses of nicotine ( approximately 12 mg/kg/day) were used. In the current study, we showed that a negative relationship also holds for low doses of nicotine that are comparable to that consumed by average human smokers (<6 mg/kg/day). We also demonstrated that 14 days of nicotine administration (4 mg/kg/day) reduced average daily food intake by 19.5% (P<0.01) in the free-feeding nicotine-treated group compared to saline controls. No significant differences in body weight were detected between the nicotine-treated and pair-fed groups. To determine whether the effects of nicotine on food intake and body weight were related to neuropeptide Y (NPY) expression, semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and radioimmunoassay were utilized to measure NPY mRNA and peptide levels in various regions of the hypothalamus. Significantly higher levels of NPY mRNA (ca. 20-50%) and peptide (ca. 24-69%) were only detected in the nicotine-treated groups. In addition, significantly higher NPY contents were also obtained in two hypothalamic areas of pair-fed control animals. In summary, our data suggest that the pharmacological effects of nicotine on food intake and body weight may be mediated by changes in hypothalamic NPY levels, a neuropeptide that is pivotal to the hypothalamic regulation of food intake.

Nicotine enhances the biosynthesis and secretion of transthyretin from the choroid plexus in rats: implications for beta-amyloid formation

Epidemiological studies indicated that cigarette smoking protects against the development of several neurodegenerative disorders, including Alzheimer's disease (AD). However, the molecular mechanism(s) underlying this is poorly understood. To gain insight into these protective effects, we used differential display PCR (DD-PCR) to amplify RNA from various brain regions of rats self-administering (SA) nicotine compared with yoked-saline controls. We found that the transthyretin (TTR) gene, whose product has been shown to bind to amyloid beta (Abeta) protein and prevent Abeta aggregation, was more abundantly expressed ( approximately 1.5- to 2.0-fold) in the brainstem and hippocampus (areas containing choroid plexus) of nicotine SA rats. Subsequently, quantitative reverse transcription-PCR analysis confirmed these DD-PCR findings and demonstrated that nicotine increased TTR mRNA levels in these regions in a time- and dose-dependent manner. Significantly higher TTR protein concentrations were also detected in the ventricular CSF of nicotine-treated rats. In contrast, no differences either in plasma TTR or in CSF and plasma retinol-binding protein were detected. Immunohistochemical analysis showed that immunoreactive TTR was 41.5% lower in the choroid plexus of nicotine-treated rats compared with the saline controls. On the basis of these data, we speculate that the protective effects of nicotine on the development of AD may be attributable, in part, to the increased biosynthesis and secretion of TTR from the choroid plexus. These findings also point toward new approaches that may take advantage of the potentially novel therapeutic effects of nicotinic agonists in patients with AD.

Identification and characterization of a new allele for the beta subunit of follicle-stimulating hormone in Chinese pig breeds

During evaluation of follicle-stimulating hormone-beta (FSHB) expression in anterior pituitary glands by an RNase protection assay (RPA), the expected fragment of 205 nucleotides at positions 759-963 was not detected in one boar that had moderate plasma and pituitary FSH concentrations. After subcloning and sequencing, mRNA from this boar lacked an 11-bp fragment (5'-CATTTGGAAAC-3') at nucleotide positions 807-817 of the 3'-untranslated region (3'-UTR, D allele). Wild-type FSHB (WT allele) was present in pituitary RNA and genomic DNA in both Meishan (MS) and White Composite (WC) pigs; whereas the D allele was present only in MS pigs (P < 0.01; 5/6 MS vs. 0/6 WC). Also, we found the D allele in five other Chinese breeds but absent in ten American Landrace, 11 Yorkshire and 17 Berkshire pigs. Additionally, the D allele had one silent nucleotide change in the coding region plus six, single nucleotide changes in the 3'-UTR.

Regulation of delta opioid receptor expression by anti-CD3-epsilon, PMA, and ionomycin in murine splenocytes and T cells

Previous studies have shown that low levels of delta opioid receptor (DOR) mRNA were detectable by reverse transcription polymerase chain reaction (RT-PCR) in unstimulated splenocytes from BALB/c female mice. This study demonstrates that DOR transcripts can be detected in freshly obtained splenocytes froin CD 1 female mice as well. The results of studies using quantitative competitive RT-PCR showed that DOR transcripts in splenic T cells increased from < 1 copy/cell to 22 and 42 copies/cell, respectively, after stimulation with anti-CD3-epsilon for 24 and 48 h compared to the level in freshly obtained T cells. In the presence of actinomycin D, anti-CD3-epsilon did not affect the rate of degradation of DOR mRNA, suggesting that its stability is not altered by anti-CD3-epsilon. After incubation with phorbol myristate acetate (PMA) and ionomycin, the expression of DOR mRNA in splenocytes and T cells was significantly reduced compared with unstimulated cells in culture. In addition, the inhibitory effect of PMA prevented anti-CD3-epsilon-stimulated DOR expression. These data suggest that signaling through the T cell receptor complex by anti-CD3-epsilon regulates DOR expression differently than PMA and ionomycin.

Positive association between expression of follicle-stimulating hormone beta and activin betaB-subunit genes in boars

This study tested our hypothesis that inhibin/activin (I/A) betaB subunit and not follistatin (FS) gene expression relates positively to plasma FSH concentrations in the anterior pituitary gland of boars. Mature crossbred boars (n = 12) were selected for divergence in plasma FSH concentrations, and their anterior pituitary glands were evaluated for expression of the FSHbeta, I/A ssB, FS, calmodulin, and GnRH receptor (GnRH-R) genes by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and/or RNase protection assays (RPAs). Expression of I/A ssB was greater (p < 0. 01) in the six boars with high FSH than in the six with low FSH; expression of the I/A betaB-subunit gene was positively correlated to that of the FSHbeta gene (RT-PCR: r = 0.96; p < 0.01; RPA: r = 0.68; p < 0.05). In contrast, expression of the FS (p > 0.10), GnRH-R (p > 0. 08), and calmodulin (p > 0.10) genes was similar in the two groups of boars. Additionally, expression of the FSHbeta gene was correlated positively with pituitary and plasma FSH concentrations (r = 0.69 and 0.88, respectively; p < 0.05). These results support the hypothesis that activin B is partially responsible for elevated FSH concentrations in boars. Furthermore, the expression difference of the calmodulin gene observed previously between Meishan and White Composite boars represents a breed difference unrelated to FSH.

Delta-opioid suppression of human immunodeficiency virus-1 expression in T cells (Jurkat)

Delta-opioid receptor (DOR) transcripts and binding sites are expressed by lymphocytes and lymphoid cell lines from several species. Direct modulation of lymphocyte function through DORs affects T cell proliferation, interleukin-2 production, chemotaxis, and intracellular signaling. Moreover, in human DOR-transfected T cells (DOR-Ju.1), delta-opioids have been shown previously to mobilize intracellular calcium rapidly, to inhibit forskolin-stimulated cyclic AMP production, and to activate the mitogen-activated protein kinases ERKs 1 and 2. These observations led us to consider whether delta agonists modify T cell functions, thus affecting the expression of human immunodeficiency virus-1 (HIV-1) by CD4+ T cells. To test this hypothesis, DOR-Ju.1 cells, derived from Jurkat cells stably transfected with a cDNA encoding the neuronal DOR, were stimulated with deltorphin or benzamide, 4-[[2,5-dimethyl-4-(2-propenyl)-1-piperazinyl](3-methoxyphenyl)methyl]N- ,[2S[(S*),2alpha,5beta]]-(9Cl) (SNC-80) prior to the addition of HIV-1. Both deltorphin and SNC-80 concentration-dependently inhibited the production of p24 antigen, an index of HIV-1 expression. Inhibition was maximal with 10(-13)-10(-9) M SNC-80 (>60% reduction) or 10(-15)-10(-11) M deltorphin (>50% reduction). At higher concentrations, less inhibition of p24 antigen production was found. Naltrindole (NTI, 10(-11) M), a selective DOR antagonist, abolished the inhibitory effects of 10(-9) M SNC-80, whereas 10(-13) M NTI partially reversed the effect of SNC-80. Thus, activation of DORs expressed by CD4+ T cells significantly (P < 0.05) reduced the expression of HIV-1 by these cells. These findings suggest that opioid immunomodulation directed at host T cells may be adjunctive to standard antiviral approaches to HIV-1 infection.

A comprehensive evolutionary analysis based on nucleotide and amino acid sequences of the alpha- and beta-subunits of glycoprotein hormone gene family

On the basis of nucleotide sequences of the coding region and their predicted amino acid sequences, 58 glycoprotein hormone subunit genes were compared, aligned and used to construct phylogenetic trees for this family. The analysis included 17 alpha-subunits, eight TSH beta-, six FSH beta-, 17 LH beta/CG beta-, four fish gonadotropin (GTH)-I beta-, five fish GTH-II beta- and one additional fish GTH beta-subunit. The reliability of the phylogenetic trees was probed with the bootstrapping test. Our results indicated that: both the alpha- and beta-subunits of the family diverged from a common ancestral gene about 927 million years ago, the initial precursor of the beta-subunit duplicated to give rise to the LH beta and a second hormone, the latter then duplicating to FSH beta and TSH beta, so that FSH beta is related more to TSH beta than to LH beta; and bony fish GTH-I beta is highly related to mammalian FSH beta, whereas the bony fish GTH-II beta is more related to mammalian LH beta. For scientific consistency and convenience, we propose that the following nomenclature be adopted, all fish gonadotropins of type I be classified as FSH and all type II be classified as LH hormones. In addition, on the basis of results from this and other studies, we propose an evolutionary history for this glycoprotein hormone family. Reconstruction of the evolutionary history of this family would not only provide clues to understanding thyrotropin and gonadotropin functions, but would also allow further revision of the present nomenclature of the gonadotropins in fish.

The electrocardiogram and the secundum atrial septal defect: a reexamination in the era of echocardiography

BACKGROUND

Ostium secundum atrial septal defects (ASDs) often present subtly and may be a diagnostic challenge to the community physician. Characteristic abnormalities of the electrocardiogram (ECG) have been described in adults.

OBJECTIVE

To determine whether ECG abnormalities are consistently present in children with a hemodynamically significant ASD, and their potential for differentiating this group from patients with innocent murmurs.

DESIGN

Retrospective evaluation of clinical characteristics, echocardiographic data, and ECGs was undertaken in 67 consecutive children with an ASD (mean age 2.9 +/- 2.8 years, 63% female) and 77 patients with innocent murmur (mean age 3.2 +/- 2.6 years, 61% male). Predetermined ECG criteria were derived from adult studies (rsR'-V1 with evidence of right ventricular hypertrophy, isolated rsR'-V1, and unequivocal right ventricular hypertrophy without rsR'-V1). ECGs were interpreted blindly by two observers.

RESULTS

In the ASD group 58 (87%) patients had an ECG that met predetermined criteria compared with three (3.9%) controls (P < 0.001). Completely normal ECGs were found in only four (6.0%) ASD patients compared with 66 (86%) controls (P < 0.001). The ECG criteria had a sensitivity of 86% (95% CI 0.784 to 0.947) and a specificity of 96% (95% CI 0.918 to 1.000). When any ECG abnormality was considered the sensitivity increased to 94% (95% CI 0.884 to 0.997) with a decline in specificity to 86% (95% CI 0.779 to 0.935).

CONCLUSIONS

The ECG is potentially a valuable adjunct to the physical examination in differentiating children with an ASD from those with an innocent murmur in the primary care setting.

Experimental evidence of a plant meridian system: V. Acupuncture effect on circumnutation movements of shoots of Phaselus vulgaris L. pole bean

When the first unifoliolate leaf of Phaselus vulgaris L. cv. Kentucky wonder pole bean was at the expended stage, two needles were inserted into opposite sides of the stem near the unifoliolate bud and left there for the entire experiment. Changes of the period of circumnutation movement at the shoots of Phaselus vulgaris L. pole bean were measured. Results from two separate experiments are reported in this communication. In the first experiment, the mean period of the ultradian rhythms of the horizontal circumnutation movement of shoots was reduced significantly (p = 0.0022) from 124.2 minutes in controls to 116.3 minutes in the treated plants. The average period of the ultradian rhythms of circumnutation movement in the treated and the untreated groups from the second experiments were 96.7 and 132.1, minutes respectively, which was statistically significant (p < 0.0001). This study demonstrates for the first time that acupuncture markedly shortens the period lengths of the ultradian rhythms of circumnutation movement of the shoots of the Phaselus vulgaris L. pole bean.

Detection of basal levels and induction of delta opioid receptor mRNA in murine splenocytes

Activation of delta opioid receptors (DOR) modulates calcium mobilization, interleukin-2 production, chemotaxis and proliferation of T-lymphocytes. Recent reports indicate that lymphocytes and mononuclear cells may express mRNA transcripts for DOR. The investigations reported herein show that low levels of DOR were consistently detected by RT-PCR amplification of RNA from freshly obtained Balb/c murine splenocytes, both weanling and adult. Culturing cells without stimulation increased DOR levels and concanavalin A apparently reduced this; DOR was preferentially expressed in a T-cell-enriched fraction. Thus, the expression of DOR mRNA by unactivated splenocytes is modulated by culture and con A in the T-cell fraction.

Expression of follistatin and inhibin/activin subunit genes in porcine follicles

Expression of the follistatin (FS) and inhibin/activin (I/A) alpha, beta(A), and beta(B) subunit genes in porcine ovarian follicles was evaluated by reverse transcriptase polymerase chain reaction and/or RNase protection procedures to establish changes during the final stages of follicular development. For the I/A alpha and beta(A) subunits, expression increased (p < 0.05) as follicles progressed to the mid-stage of the follicular phase. The beta(B) subunit was expressed in lower concentrations, and all three I/A subunits showed a marked reduction (p < 0.01) in expression by the late stage of follicular development. In contrast to this pattern, FS gene expression decreased (p < 0.05) as follicles developed from the early (low estradiol) to the mid stage (high estradiol) and continued to decline in advanced follicles (after estrus). The predominant mRNA encoded for FS-315, and the ratio of mRNA for FS-315 to mRNA for FS-288 did not differ significantly during the three stages. Within an animal, concentration of FS mRNAs was related more to stage of the follicular phase than to follicular size. Follicular fluid concentration of FS changed in a manner similar to that observed for expression of its gene. We conclude that expression of the FS gene and translation of its mRNA decrease as follicles approach ovulatory status.

Breed differences in expression of inhibin/activin subunits in porcine anterior pituitary glands

Chinese Meishan (MS) boars have greater plasma FSH concentrations than European White Composite boars, but this difference does not occur in females of these breeds. To understand this disparity, we studied expression of the follistatin gene and of genes for the inhibin/activin alpha-, beta A-, and beta B-subunits in porcine anterior pituitary glands using quantitative reverse transcription-PCR and ribonuclease protection techniques. We found that 1) the inhibin/activin beta A- and beta B-subunits and follistatin were expressed in porcine pituitary, 2) the alpha-subunit was not detected in the porcine pituitary, but was highly expressed in porcine follicles; and 3) the beta B-subunit gene is more abundantly expressed (2-fold greater) in MS boar pituitaries than in pituitaries of White Composite boars. We conclude that this is not due to a breed difference, because the expression levels of this gene were similar in pituitaries of females of these breeds. No breed differences were detected for other genes screened in this study. From these observations, we propose that activin B, a dimer of beta B-subunits and a stimulator of FSH secretion, may be partially responsible for the elevated plasma FSH concentrations in MS boars, and intrapituitary inhibin plays no or a very minimal role.

Experimental evidence of a plant meridian system: IV. The effects of acupuncture on growth and metabolism of Phaseolus vulgaris L. beans

We have shown previously that plants exhibit functional characteristics similar to the meridian system in humans and animals, such as high potential and low electrical resistance, high temperature, and spontaneous sound production. Here we will show the effect of acupuncture on plants. When plants of Phaseolus vulgaris L. pole bean (cv. Kentucky wonder) and bush bean (cv. Slenderette) were subjected to acupuncture by inserting two needles into opposite sides of the stem of the unifoliolate buds, it was found that acupuncture strengthened the growth and development of the plants. Two repeated experiments showed that the mean net photosynthesis rate of plants subjected to acupuncture increased about 20.5%, the mean transpiration 27.2%, the growth and total length of internodes 22.5%, and the total dry weight of shoots from the cotyledon to the apex 22.9%, in comparisons with control plants under the same growing conditions. In addition, treated plants flowered three days earlier and had 14.4% more fruit than the untreated control plants. Thus, acupuncture may serve as a viable technique for increasing yield in agricultural plants.

Overexpression of beta-subunit of thyroid-stimulating hormone in Meishan swine identified by differential display

Anterior pituitary gland RNA isolated from Meishan (MS) and White Composite (WC) sexually mature boars was compared by a newly developed method of differential expression cloning called differential display. A number of cDNAs were identified that differed distinctly in expression between these breeds. The gene for beta-subunit of thyroid-stimulating hormone (TSH-beta) was initially identified as more highly expressed in MS than in WC boars. Subsequently, RNase protection assays and TSH RIA were used to quantify the magnitude of differences in transcription and translation in both males and females. Mature MS pigs had threefold greater expression of TSH-beta (P < .05) and greater plasma TSH concentrations than mature WC pigs (P < .01). The cDNA cloning and sequence analyses indicate identity in TSH-beta mRNA between MS and WC males. Elevated plasma TSH concentration may contribute MS pigs reaching sexual maturity earlier than WC or other European breeds. The method used in this study provides a useful molecular tool 1) to detect differentially expressed genes, 2) to study genetic variation that occurs at the transcription level between individuals, populations, or breeds; and additionally, 3) to identify candidate genes that control economically important quantitative traits in livestock.