Cigarette smoking in male patients with chronic schizophrenia in a Chinese population: prevalence and relationship to clinical phenotypes

The high prevalence of smoking in schizophrenia of European background may be related to smoking's reducing clinical symptoms and medication side effects. Because smoking prevalence and its associations with clinical phenotypes are less well characterized in Chinese than European patients with schizophrenia, we assessed these smoking behaviors using clinician-administered questionnaires and the Fagerstrom Test for Nicotine Dependence (FTND) in 776 Chinese male schizophrenia and 560 control subjects. Patients also were rated on the Positive and Negative Symptom Scale (PANSS), the Simpson and Angus Extrapyramidal Symptom Rating Scale (SAES), and the Abnormal Involuntary Movement Scale (AIMS). We found that the schizophrenia patients had a higher lifetime incidence of smoking (79% vs 63%), were more likely to be heavy smokers (61% vs 31%), and had lower smoking cessation rates (4% vs 9%) (all p<0.0001) than controls. Among the schizophrenia patients smoking prevalence increased with age, with the largest difference from controls in the age cohort of 55-75 years: 75% vs 46% (p<0.0001). Among the schizophrenia smokers 73% started to smoke before the onset of their illness by an average of 7.6 years. The patients with schizophrenia who were current smokers scored significantly lower on the PANSS negative symptom subscore (p<0.005), and on the SAES symptom scale (p<0.04; Bonferroni corrected p>0.05) than the non-smoking patients. These results suggest that Chinese males with schizophrenia smoke more frequently than the general population. Further, smokers with schizophrenia may display fewer negative symptoms and possibly less parkinsonism than non-smokers with schizophrenia.     

Cigarette smoking and cognitive function in Chinese male schizophrenia: a case-control study

Schizophrenic patients have higher smoking rates than the general population. Studies show that smoking may be a form of self-medication in an attempt to alleviate cognitive deficits in schizophrenic patients of European background. This study examined the relationships between smoking and cognitive deficits in Chinese schizophrenic patients, which have previously received little systemic study. We recruited 580 male chronic patients meeting DSM-IV criteria for schizophrenia and 175 male control subjects who were matched on age and education. The subjects completed a detailed cigarette smoking questionnaire, the Fagerstrom Test for Nicotine Dependence (FTND), and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Patients also were rated on the Positive and Negative Symptom Scale (PANSS), the Simpson and Angus Extrapyramidal Symptom Rating Scale (SAES), and the Abnormal Involuntary Movement Scale (AIMS). All five RBANS subscales except for the Visuospatial/Constructional index showed significantly lower cognitive performance for schizophrenics than normal controls. The schizophrenic smokers scored lower than the schizophrenic non-smokers on the RBANS total score and the Visuospatial/Constructional and Immediate Memory indices. Similarly, the control smokers scored lower than the control non-smokers on the RBANS total score and the Immediate Memory index . Also, the schizophrenic smokers consistently performed the poorest on the cognitive domains of the RBANS. Among the schizophrenic patients, smokers displayed significantly fewer negative symptoms than non-smokers. Using multivariate regression analysis the following variables were independently associated with the RBANS total score: years of education, PANSS negative symptom score, age at schizophrenia onset, and number of hospitalizations. Our results show that smoking is associated with significant cognitive impairment in both schizophrenic patients and normal controls, but the smokers with schizophrenia had a reduced level of negative symptoms, suggesting that the benefits of smoking for those with schizophrenia may be limited to certain aspects of a given clinical phenotype.     

Forestry alters foraging efficiency and crop contents of aphid-tending red wood ants, Formica aquilonia

Forest management alters species behaviours, distributions and interactions. To evaluate forestry effects on ant foraging performance, we compared the quality and quantity of honeydew harvested by ants among clear-cuts, middle-aged and mature spruce-dominated stands in boreal forests in Sweden. Honeydew quality was examined using honeydew collected by squeezing the gasters of laden Formica aquilonia workers. We used fifteen laden individuals at each study site (four replicates of each stand age) and analysed honeydew chemical composition with gas chromatography-mass spectroscopy. To compare the quantity of honeydew collected by individual ants, we collected and weighed five ants moving up and five ants moving down each of ten trees at the twelve sites (totally 1200 ants). The concentration of trehalose in honeydew was lower in clear-cuts compared with middle aged and mature stands, and similar trends were shown for sucrose, raffinose and melezitose, indicating poorer honeydew quality on clear cuts. Concentrations of the amino acid serine were higher on clear-cuts. The same trend occurred for glutamine, suggesting that increased N-uptake by the trees after clear cutting is reflected in the honeydew of aphids. Ants in mature stands had larger heads and carried proportionally more honeydew and may therefore be more efficient foragers. Human alternation of habitats through clear-cutting thus affects food quality and worker condition in F. aquilonia. This is the first study to show that honeydew quality is affected by anthropogenic disturbances, likely contributing to the reduction in size and abundance of F. aquilonia workers and mounds after clear cutting.     

Centrosome misorientation mediates slowing of the cell cycle under limited nutrient conditions in Drosophila male germline stem cells

Drosophila male germline stem cells (GSCs) divide asymmetrically, balancing self-renewal and differentiation. Although asymmetric stem cell division balances between self-renewal and differentiation, it does not dictate how frequently differentiating cells must be produced. In male GSCs, asymmetric GSC division is achieved by stereotyped positioning of the centrosome with respect to the stem cell niche. Recently we showed that the centrosome orientation checkpoint monitors the correct centrosome orientation to ensure an asymmetric outcome of the GSC division. When GSC centrosomes are not correctly oriented with respect to the niche, GSC cell cycle is arrested/delayed until the correct centrosome orientation is reacquired. Here we show that induction of centrosome misorientation upon culture in poor nutrient conditions mediates slowing of GSC cell proliferation via activation of the centrosome orientation checkpoint. Consistently, inactivation of the centrosome orientation checkpoint leads to lack of cell cycle slowdown even under poor nutrient conditions. We propose that centrosome misorientation serves as a mediator that transduces nutrient information into stem cell proliferation, providing a previously unappreciated mechanism of stem cell regulation in response to nutrient conditions.     

Toll-Like Receptor (TLR2 and TLR4) Polymorphisms and Chronic Obstructive Pulmonary Disease

Toll-like receptors (TLRs) participate in the defence against bacterial infections that are common in patients with Chronic Obstructive Pulmonary Disease (COPD). We studied all tagging SNPs in TLR2 and TLR4 and their associations with the level and change over time of both FEV(1) and sputum inflammatory cells in moderate-to-severe COPD. Nine TLR2 SNPs and 17 TLR4 SNPs were genotyped in 110 COPD patients. Associations of SNPs with lung function and inflammatory cells in induced sputum were analyzed cross-sectionally with linear regression and longitudinally with linear mixed-effect models. Two SNPs in TLR2 (rs1898830 and rs11938228) were associated with a lower level of FEV(1) and accelerated decline of FEV(1) and higher numbers of sputum inflammatory cells. None of the TLR4 SNPs was associated with FEV(1) level. Eleven out of 17 SNPs were associated with FEV(1) decline, including rs12377632 and rs10759931, which were additionally associated with higher numbers of sputum inflammatory cells at baseline and with increase over time. This is the first longitudinal study showing that tagging SNPs in TLR2 and TLR4 are associated with the level and decline of lung function as well as with inflammatory cell numbers in induced sputum in COPD patients, suggesting a role in the severity and progression of COPD.     

Micro and macro-habitat associations in saproxylic beetles: implications for biodiversity management

Restoration of habitats is critically important in preventing full realization of the extinction debt owed as a result of anthropogenic habitat destruction. Although much emphasis has been placed on macrohabitats, suitable microhabitats are also vital for the survival of most species. The aim of this large-scale field experiment was to evaluate the relative importance of manipulated microhabitats, i.e., dead wood substrates of spruce (snags, and logs that were burned, inoculated with wood fungi or shaded) and macrohabitats, i.e., stand types (clear-cuts, mature managed forests, and forest reserves) for species richness, abundance and assemblage composition of all saproxylic and red-listed saproxylic beetles. Beetles were collected in emergence traps in 30 forest stands in 2001, 2003, 2004 and 2006. More individuals emerged from snags and untreated logs than from burned and shaded logs, but species richness did not differ among substrates. Assemblage composition differed among substrates for both all saproxylics and red-listed saproxylic species, mainly attributed to different assemblage composition on snags. This suggests that the practise of leaving snags for conservation purposes should be complemented with log supplementation. Clear-cuts supported fewer species and different assemblages from mature managed forests and reserves. Neither abundance, nor species richness or assemblage composition differed between reserves and mature managed forests. This suggests that managed stands subjected to selective cutting, not clear-felling, maintain sufficient old growth characteristics and continuity to maintain more or less intact assemblages of saproxylic beetles. Thus, alternative management methods, e.g., continuity forestry should be considered for some of these stands to maintain continuity and conservation values. Furthermore, the significantly higher estimated abundance per ha of red-listed beetles in reserves underlines the importance of reserves for maintaining viable populations of rare red-listed species and as source areas for saproxylic species in boreal forest landscapes.     

The effects of artificial gender imbalance. Science & Society Series on Sex and Science

The use of reproductive technology to service a preference for male offspring has created an artificial gender imbalance, notably in Asian countries. The social effects of this large surplus of young men are not yet clear, but concerted action might be necessary to address the problemOne of the problems of sexual reproduction, especially in predominantly monogamous species that pair ‘for life'', is to ensure a balance between the birth rate of males and females. In humans, this balance has been remarkably even, but the past few decades have seen a substantial shift towards men, notably in some Asian countries. The reason, however, is not biological; there has simply been a cultural preference for sons in the affected societies, which together with recent availability of prenatal sex-selection technologies has led to widespread female feticide. The result has been a huge excess of males in several countries. Whilst it is not yet fully clear how a surplus of millions of men will affect these societies—perhaps even leading to civil unrest—some countries have already taken steps to alleviate the problem by addressing the underlying cultural factors. However, the problem is about to come to a crisis point, as a large surplus of men reach reproductive age. It will take many decades to reach a balanced representation of both sexes again.The sex ratio at birth (SRB) is defined as the number of boys born to every 100 girls. It is remarkably consistent in human populations, with around 103–107 male babies for every 100 female ones. John Graunt first documented this slight excess of male births in 1710 for the population of London, and many studies have since confirmed his finding [1]. Higher mortality from disease, compounded by the male tendency towards risky behaviours and violence, means that the initial surplus of boys decreases to roughly equal number of males and females during the all-important reproductive years in most populations.Researchers have studied a large number of demographic and environmental factors that could affect the SRB, including family size, parental age and occupation, birth order, race, coital rate, hormonal treatments, environmental toxins, several diseases and, perhaps most intriguingly, war [2,3,4]. It is well documented that wars are associated with a small increase in the sex ratio. This phenomenon occurs both during the war and for a short period afterwards. The best examples of this were reported for the First and Second World Wars in both the USA and Europe, and for the Korean and Vietnam Wars in the USA [5,6]. However, these findings were not reproduced in the more recent Balkan Wars and the Iran–Iraq war [7]. There have been several biological explanations for these increases. It has been proposed, for example, that the stress of war adversely affects the viability of XY-bearing sperm. Alternatively, a higher frequency of intercourse after prolonged separation during times of war is thought to lead to conception earlier in the menstrual cycle, which has been shown to result in more males [4,8]. There have been evolutionary explanations, such as the loss of large numbers of men in war leading to an adaptive correction of the sex ratio [4,9]. Nonetheless, the real causes of the altered SRB during war remain elusive: all of the discussed biological and social factors have been shown to cause only marginal deviations from the normal sex ratio.Whilst war has only slightly shifted SRB towards more male babies and only for a limited time period, cultural factors, namely a strong preference for sons, has been causing large distortions of gender balance during the past decades. Son preference is most prevalent in a band of countries from East Asia through to South Asia and the Middle East to North Africa [9]. For centuries, sons have been regarded as more valuable, because males can earn higher wages especially in agrarian economies, they generally continue the family line, are recipients of inheritance and are responsible for their parents in illness and old age. By contrast, daughters often become members of the husband''s family after marriage, no longer having responsibility for their biological parents [10]. There are also location-specific reasons for son preference: in India, the expense of the dowry, and in South Korea and China, deep-rooted Confucian values and patriarchal family systems [11].… cultural factors, namely a strong preference for sons, has been causing large distortions of gender balance during the past decadesUntil recently, son preference was manifest post-natally through female infanticide, abandonment of newborn girls, poorer nutrition and neglect of health care, all causing higher female mortality [12]. Studies have shown that unequal access to health care is the most important factor in differential gender mortality [13,14], especially in countries where health care costs are borne by the family [15]. As early as 1990, the Indian economist Amaryta Sen estimated that differential female mortality had resulted in around 100 million missing females across the developing world with the overwhelming majority of these in China, India, Pakistan and Bangladesh [16].

Science & Society Series on Sex and Science

Sex is the greatest invention of all time: not only has sexual reproduction facilitated the evolution of higher life forms, it has had a profound influence on human history, culture and society. This series explores our attempts to understand the influence of sex in the natural world, and the biological, medical and cultural aspects of sexual reproduction, gender and sexual pleasure.To make matters worse, during the 1980s, diagnostic ultrasound technology became available in many Asian countries, and the opportunity to use the new technology for prenatal sex selection was soon exploited. Indeed, the highest SRBs are seen in countries with a combination of son preference, easy access to sex-selection technologies and abortion, and a small family culture. The latter is important because where larger families are the norm, couples will continue to have children until they have a boy. If the couple plan, or are legally restricted, as in China, to only one or two children, they will use sex selection to ensure the birth of a son [17]. This combination has resulted in serious and unprecedented sex ratio imbalances that are now affecting the reproductive age groups in several countries, most notably China, South Korea and parts of India.South Korea was the first country to report a very high SRB, because the widespread uptake of sex-selection technology preceded other Asian countries. The sex ratios started to rise in the mid-1980s in cities; ultrasound was already widely available even in rural areas by 1990 [17]. By 1992, the SRB was reported to be as high as 125 in some cities.South Korea was the first country to report a very high SRB, because the widespread uptake of sex-selection technology preceded other Asian countriesChina soon followed. Here, the situation was further complicated by the one-child policy introduced in 1979. This has undoubtedly contributed to the steady increase in the reported SRB from 106 in 1979 to 111 in 1990, 117 in 2001, 121 in 2005 and as high as 130 in some rural counties [18]. The latest figures for 2010 report an SRB of 118 [19] (National Bureau of Statistics of China 2011), the first drop in three decades, suggesting an incipient downturn. However, the number of excess males in the reproductive age group will continue to increase for at least another two decades. Because of China''s huge population, these ratios translate into massive numbers: in 2005, an estimated 1.1 million excess males were born across the country and the number of males under the age of 20 might exceed females by around 30 million [18].These overall figures conceal wide variations across the country (Fig 1): the SRB is higher than 130 in a strip of heavily populated provinces from Henan in the north to Hainan in the south, but close to normal in the large sparsely populated provinces of Xinjiang, Inner Mongolia and Tibet. Some are sceptical about these high SRB figures or have suggested that, under the constraints of the one-child policy, parents might fail to register a newborn girl, so that they might go on to have a boy [20]. However, recent evidence shows that such under-registration explains only a small proportion of missing females and that sex-selective abortion undoubtedly accounts for the overwhelming majority [18].Open in a separate windowFigure 1Sex ratio at birth for China''s provinces in 2005.There are marked regional differences in SRB in India. Because incomplete birth registrations make the SRB difficult to calculate accurately, the closely related ratio of boys to girls under the age of six is used, showing distinct regional differences across the country with much higher levels in the north and west. According to the most recent census in 2010, the SRB for the whole country was 109, a marginal increase on the previous census in 2001, which showed an SRB of 108. These national figures, however, hide wide differences from a low SRB of 98 in the state of Kerala to 119 in Haryana State. The highest SRBs at district level for the whole of India are in two districts of Haryana state, where the SRBs are both 129 [21]. The Indian figures contrast with the Chinese in two ways: nowhere in China is the sex ratio low, and in India the sex ratio is higher in rural than urban areas, whereas the reverse is true for China [22].A consistent pattern in all three countries is a clear trend across birth order, that is first, second and subsequent children, and the sex of the preceding child. This is driven by the persistence of the ‘at least one boy'' imperative in these cultures. Where high fertility is the norm, couples will continue to reproduce until they have a boy. Where couples aim to restrict their family size, they might be content if the first child is a girl, but will often use sex selection to ensure a boy in the second pregnancy. This was shown in a large Indian study: the SRB was 132 for second births with a preceding girl, and 139 for third births with two previous girls. By contrast, the sex ratios were normal when the first born was a boy [23].The sex ratio by birth order is particularly interesting in China (18].

Table 1

Sex ratio at birth for China''s provinces in 2005.