Healthcare Utilization, Physical and Psychiatric Comorbidities Before Self-Injurious Behavior in Patients with Asthma: A Nested Case-Control Study

Background

Patients with asthma experience more physical, psychological, and financial burdens; a link between asthma and suicidality has been reported in research.

Purpose

This study analyzed the medical utilization and comorbidity before their self-injurious behavior in patients with asthma.

Methods

We enrolled 186,862 patients newly diagnosed with asthma between 1999 and 2013 from the National Health Insurance Research Database in Taiwan. A total of 500 case subjects had ever conducted self-injurious behaviors during the study period. Based on a nested case-control study, each case was matched with 10 controls derived from the asthma cohort to analyze differences between them and their medical use models.

Results

The results indicated that, compared to the control group, the cases presented higher frequencies of outpatient visits and hospitalizations. Regarding comorbidity, the cases had more cardiovascular diseases (adjusted odds ratio [aOR]=1.58; p<0.001), bipolar disorder (aOR=2.97; p<0.001), depression (aOR=4.44; p<0.001), and sleep disorder (aOR=1.83; p<0.001) than the controls.

Conclusion

The evidence-based information serves as a reference for medical staff to reduce the occurrence of self-injurious behavior in patients with asthma.

Healthcare utilization and comorbidity shortly before suicide mortality in patients with attention-deficit/hyperactivity disorder: a nested case-control study

BACKGROUND

Few studies have analyzed healthcare utilization before suicide among individuals with attention-deficit/hyperactivity disorder (ADHD). This study examined the pattern of healthcare utilization and comorbidities shortly before death among patients with ADHD who died by suicide and compared these data with those of living controls. This study used Taiwan's National Health Insurance Research Database to identify patients with ADHD (N = 379,440) between January 1, 2001, and December 31, 2016. Subsequently, the researchers identified 159 suicide decedents by linking each patient with the National Mortality Database. By conducting a nested case-control study with risk-set sampling from the ADHD cohort, the researchers selected 20 age- and sex-matched controls (n = 3180) for each patient who died by suicide (cases). The researchers then applied conditional logistic regression to investigate differences in healthcare utilization as well as psychiatric and physical comorbidities between case patients and controls. Case patients had higher healthcare utilization within 3 months before suicide, particularly in the psychiatry, emergency, internal medicine, neurosurgery, and plastic surgery departments. These patients also had higher risks of psychiatric comorbidities, including schizophrenia, bipolar disorder, depressive disorder, and sleep disorder, as well as physical comorbidities such as hypertension and other forms of heart disease. Among patients with ADHD, suicide decedents had increased healthcare utilization and higher risks of specific psychiatric and physical comorbidities than living controls. Thus, for suicide prevention among individuals with ADHD, suicide risk must be detected early and comorbidities should be adequately managed.

Unfavorable cancer mortality-to-incidence ratios in patients with schizophrenia: A nationwide cohort study in Taiwan, 2000-2019

OBJECTIVES

Studies on cancer incidence and mortality in patients with schizophrenia have reported inconsistent findings. In this study, we simultaneously investigated cancer incidence and mortality in patients with schizophrenia and evaluated the cancer mortality-to-incidence ratio (MIR), which is rare in the literature.

METHODS

From the Taiwan National Health Insurance Database, we collected the data of 107,489 patients who received a diagnosis of schizophrenia between 2000 and 2019. Data regarding cancer incidence and mortality were obtained from the Taiwan Cancer Registry and National Mortality Database, respectively. In total, 3881 incident cancer cases and 2288 cancer mortality cases were identified. Standardized incidence ratios (SIRs), mortality rate ratios (MRRs), and MIRs were compared between patients with schizophrenia and the general population.

RESULTS

The overall rate of cancer incidence was slightly lower (SIR: 0.95; 95% confidence interval [CI]: 0.92-0.98; p < 0.001) and that of cancer mortality was higher (MRR: 1.29; 95% CI: 1.23-1.3; p < 0.001) in patients with schizophrenia than in the general population. The MIR for overall cancer was significantly higher in the patients with schizophrenia. The relative MIR (MIR of patients with schizophrenia divided by that of the general population) was 1.36 (95% CI: 1.30-1.42).

CONCLUSION

The MIR was significantly higher in the patients with schizophrenia than in the general population, indicating the possible presence of healthcare disparities. Additional studies are required to investigate the potential association between the significantly higher MIR in patients with schizophrenia and healthcare disparities.

Clozapine and its protective effect on all-cause, natural, and suicide mortality in patients with schizophrenia: A nationwide cohort study in Taiwan

AIM

Clozapine is indicated as the last-line agent for the treatment of refractory schizophrenia due to its side effects. This study included an Asian schizophrenia population and investigated the effect of clozapine on the risks of all-cause, natural, and suicide mortality.

METHODS

This study included a large-scale schizophrenia inpatient cohort derived from the National Health Insurance Research Database from January 1, 2001, to December 31, 2019 (n = 43,025). Of them, we selected those who received clozapine (clozapine cohort, n = 5800). From those who never used clozapine, we selected two individuals for each patient in the clozapine cohort by matching by age, sex, and the year of the index date (ratio: 1:2, control cohort, n = 11,583). The clozapine and nonclozapine control cohorts together were defined as the study cohort (n = 17,383). Multivariate Cox proportional-hazards regression with a time-dependent model was performed to investigate the effect of individual antipsychotic agents on mortality.

RESULTS

All individual first-generation antipsychotics were not associated with mortality risk. However, most individual second-generation antipsychotics exerted protective effects against all-cause and natural mortality. Furthermore, only clozapine and risperidone were significantly associated with a low risk of suicide mortality. Only clozapine exhibited a dose-dependent relationship with all-cause, natural, and suicide mortality.

CONCLUSIONS

This study provides robust evidence supporting the strong protective effect of clozapine on all-cause, suicide, and natural mortality risks in an Asian population. Under close monitoring, clozapine use can be advantageous in patients with schizophrenia who are at a high risk of suicide.

Healthcare utilization, psychiatric disorders, and physical illnesses shortly before suicide mortality in adolescents in Taiwan

BACKGROUND

This study examined the pattern of medical utilization and the distribution of comorbidities shortly before death among adolescents who died from suicide and compared these data with those of living controls.

METHODS

From Taiwan's National Health Insurance Research Database, this study identified adolescents aged 10-19 years who died from suicide (n = 935) between 1 January 2000, and 31 December 2016, by linking each patient with the national mortality database. The researchers conducted a nested case-control study through risk set sampling, and for each case, 20 age- and sex-matched controls (n = 18 700) were selected from the general population. The researchers applied conditional logistic regression to investigate differences in medical utilization and physical and psychiatric comorbidities between cases and controls.

RESULTS

Cases had a higher proportion of contact with the psychiatric department but a similar proportion of contact with any non-psychiatric medical department within 1 year before suicide compared with controls. There were 18.6% of adolescent suicide victims who only had contacted with a psychiatric department 3 months before suicide. Moreover, cases had a higher proportion of contact with non-psychiatric services within 3 months before suicide, particularly with emergency, surgery, and internal medicine departments. Cases had higher risks of several psychiatric disorders and physical illnesses, including heart diseases, pneumonia, and ulcer disease, than did controls.

CONCLUSIONS

The findings of increased medical utilization and higher risks of physical and psychiatric comorbidities in adolescent suicide victims are crucial for developing specific interventions to prevent suicide in this population.

Sex-specific risk profiles for suicide mortality in bipolar disorder: incidence, healthcare utilization and comorbidity

BACKGROUND

Evidence on sex-specific incidence and comorbidity risk factors of suicide among patients with bipolar disorder is scarce. This study investigated the sex-specific risk profiles for suicide among the bipolar disorder population in terms of incidence, healthcare utilization and comorbidity.

METHODS

Using data from the Taiwan National Health Insurance Research Database between 1 January 2000 and 31 December 2016, this nationwide cohort study included patients with bipolar disorder (N = 46 490) and individuals representative of the general population (N = 185 960) matched by age and sex at a 1:4 ratio. Mortality rate ratios (MRRs) of suicide were calculated between suicide rates of bipolar disorder cohort and general population. In addition, a nested case-control study (1428 cases died by suicide and 5710 living controls) was conducted in the bipolar disorder cohort to examine the sex-specific risk of healthcare utilization and comorbidities.

RESULTS

Suicide risk was considerably higher in the cohort (MRR = 21.9) than in the general population, especially among women (MRR = 35.6). Sex-stratified analyses revealed distinct healthcare utilization patterns and physical comorbidity risk profiles between the sexes. Although female patients who died by suicide had higher risks of nonhypertensive cardiovascular disease, pneumonia, chronic kidney disease, peptic ulcer, irritable bowel syndrome, and sepsis compared to their living counterparts, male patients who died by suicide had higher risks of chronic kidney disease and sepsis compared to the living controls.

CONCLUSIONS

Patients with bipolar disorder who died by suicide had sex-specific risk profiles in incidence and physical comorbidities. Identifying these modifiable risk factors may guide interventions for suicide risk reduction.

Mood stabilizers and risk of all-cause, natural, and suicide mortality in bipolar disorder: A nationwide cohort study

OBJECTIVES

People with bipolar disorder have an elevated risk of mortality. This study evaluated associations between the use of mood stabilizers and the risks of all-cause mortality, suicide, and natural mortality in a national cohort of people with bipolar disorder.

METHODS

In this nationwide cohort study, we used data from January 1, 2000, to December 31, 2016, collected from Taiwan's National Health Insurance Research Database and included 25,787 patients with bipolar disorder. Of these patients, 4000 died during the study period (including 760 and 2947 from suicide and natural causes, respectively). Each standardized mortality ratio (SMR) was calculated as the ratio of observed mortality in the bipolar cohort to the number of expected deaths in the general population. Multivariable Cox proportional hazards regression with a time-dependent model was performed to estimate the hazard ratio (HR) of each mood stabilizer with each mortality outcome.

RESULTS

The SMRs of all-cause mortality, suicide, and natural mortality in the bipolar disorder cohort were 5.26, 26.02, and 4.68, respectively. The use of mood stabilizers was significantly associated with decreased risks of all-cause mortality (adjusted HR [aHR] = 0.58, p< 0.001), suicide (aHR = 0.60, p < 0.001), and natural mortality (aHR = 0.55, p < 0.001) within a 5-year follow-up period after index admission. Among the individual mood stabilizers, lithium was associated with the lowest risks of all-cause mortality (aHR = 0.38, p < 0.001), suicide (aHR = 0.39, p < 0.001), and natural mortality (aHR = 0.37, p < 0.001).

CONCLUSION

In addition to having protective effects against suicide and all-cause mortality, mood stabilizers also exert a substantial protective effect against natural mortality, with lithium associated with the lowest risk of mortality.

Sex-specific incidences and risk profiles of suicide mortality in people with alcohol dependence in Taiwan

BACKGROUND AND AIMS

Alcohol-related mental health burden and suicidality impose heavy burdens on global public health. This study measured the sex-specific incidence and risk profiles of suicide mortality in individuals with alcohol dependence in a non-western context.

DESIGN

In this prospective cohort study, individuals with alcohol dependence who were enrollees in Taiwan's National Health Insurance Research database were followed-up over an almost 15-year period. Their data were linked to the national mortality registration database.

SETTING

Taiwan.

PARTICIPANTS

In total, 278 345 patients with alcohol dependence were enrolled and followed-up from 1 January 2001 to 31 December 2016.

MEASUREMENTS

We calculated the incidence and standardized mortality ratio (SMR) of suicide in the cohort and stratified the suicide methods by sex. Sex-specific risk profiles (based on demographic characteristics and physical and psychiatric comorbidities) were generated through Cox proportional hazards regression.

FINDINGS

The suicide rates of men and women were 173.5 and 158.9 per 100 000 person-years, respectively (P = 0.097). The SMR of suicide mortality was more than two times higher in women than in men (6.6 versus 15.0). Women and men adopted different suicide methods. A multivariable Cox proportional hazards regression with a time-varying model revealed that depressive disorder was a common risk factor for suicide in both men and women [adjusted hazard ratio (aHR) = 3.03, 95% confidence interval (CI) = 2.77-3.31 versus aHR = 5.46, 95% CI = 4.65-6.40]. For men, receiving a diagnosis of alcohol dependence between the ages of 25 and 44 years, being unemployed and having schizophrenia, drug-induced mental disorder or sleep disorder were risk factors for suicide.

CONCLUSION

In Taiwan, the incidence of suicide in patients with alcohol dependence is substantially higher than that of the general population. The standardized mortality ratio of suicide in women with alcohol dependence is more than twice that of men with alcohol dependence.

[Research advances on the application of natural and recombinant collagen in wound repair]

Collagen is a macromolecular protein constituting the extracellular matrix of animal connective tissue, which has been widely used and developed in fields of biomedicine, tissue engineering, food, and cosmetics. Due to its advantages such as abundant sources and good biocompatibility, low immunogenicity, and degradability, collagen can be used as a dressing or tissue engineering scaffold for wound repair. According to the source of materials, collagen can be divided into natural collagen and recombinant collagen. Natural collagen is mainly extracted directly from mammals and fish; recombinant collagen is obtained based on genetic engineering technology, and its sources include recombinant expression systems of microorganisms, animals, and plants. This paper summarizes the sources of collagen, and the roles, advantages, and disadvantages of different sources of collagen in wound repair, the particularity and superiority of collagen combined with three-dimensional printing technology in wound repair, the impact of market norms of China's collagen industry on the field of wound repair, and explains the precautions for the development of collagen-related products, aiming to provide new ideas for selecting a suitable source of collagen for wound repair.

Prevalence and 5-year trend of incidence for medical illnesses after the diagnosis of bipolar disorder: A nationwide cohort study

OBJECTIVE

Medical comorbidities are prevalent in patients with bipolar disorder. Evaluating longitudinal trends of the incidence of medical illnesses enables implementation of early prevention strategies to reduce the high mortality rate in this at-risk population. However, the incidence risks of medical illnesses in the early stages of bipolar disorder remain unclear. This study investigated the incidence and 5-year trend of medical illnesses following bipolar disorder diagnosis.

METHODS

We identified 11,884 patients aged 13-40 years who were newly diagnosed as having bipolar disorder during 1996-2012 and 47,536 age- and sex-matched controls (1:4 ratio) who represented the general population from Taiwan's National Health Insurance Research Database. We estimated the prevalence and incidence of individual medical illnesses yearly across the first 5 years after the index date. The adjusted incidence rate ratio was calculated to compare the occurrence of specific medical illnesses each year between the bipolar disorder group and control group using the Poisson regression model.

RESULTS

Apart from the prevalence, the adjusted incidence rate ratios of most medical illnesses were >1.00 across the first 5-year period after bipolar disorder diagnosis. Cerebrovascular diseases, ischaemic heart disease, congestive heart failure, other forms of heart disease, renal disease and human immunodeficiency virus infection exhibited the highest adjusted incidence rate ratios during the first year. Except for that of renal disease, the 5-year trends of the adjusted incidence rate ratios decreased for cerebrovascular diseases, cardiovascular diseases (e.g. ischaemic heart disease, other forms of heart disease, and vein and lymphatic disease), gastrointestinal diseases (e.g. chronic hepatic disease and ulcer disease) and communicable diseases (e.g. human immunodeficiency virus infection, upper respiratory tract infection and pneumonia).

CONCLUSION

Incidence risks of medical illnesses are increased in the first year after bipolar disorder diagnosis. Clinicians must carefully evaluate medical illnesses during this period because the mortality rates from medical illnesses are particularly high in people with bipolar disorder.

I-line photolithographic metalenses enabled by distributed optical proximity correction with a deep-learning model

High pattern fidelity is paramount to the performance of metalenses and metasurfaces, but is difficult to achieve using economic photolithography technologies due to low resolutions and limited process windows of diverse subwavelength structures. These hurdles can be overcome by photomask sizing or reshaping, also known as optical proximity correction (OPC). However, the lithographic simulators critical to model-based OPC require precise calibration and have not yet been specifically developed for metasurface patterning. Here, we demonstrate an accurate lithographic model based on Hopkin's image formulation and fully convolutional networks (FCN) to control the critical dimension (CD) patterning of a near-infrared (NIR) metalens through a distributed OPC flow using i-line photolithography. The lithographic model achieves an average ΔCD/CD = 1.69% due to process variations. The model-based OPC successfully produces the 260 nm CD in a metalens layout, which corresponds to a lithographic constant k₁ of 0.46 and is primarily limited by the resolution of the photoresist. Consequently, our fabricated NIR metalens with a diameter of 1.5 mm and numerical aperture (NA) of 0.45 achieves a measured focusing efficiency of 64%, which is close to the calculated value of 69% and among the highest reported values using i-line photolithography.

Premature death and causes of death among patients with panic disorder and comorbid psychiatric disorders: A nationwide cohort study

OBJECTIVES

Panic disorder (PD) is associated with high psychiatric and physical comorbidity, but the cause of mortality has not been well studied. This study investigated mortality rates and causes of death in an Asian cohort with PD.

METHODS

We enrolled a nationwide retrospective cohort of 298,466 persons diagnosed with PD from January 1, 2001, to December 31, 2016. Each cohort member was matched with a comparison one randomly selected from the general population with the same sex, age at entry, and birth year. The data of both the PD cohort and the comparison group were linked with the national mortality database to obtain each individual's mortality status. We used mortality rate ratios (MRRs) to compare mortality risks between the patients with PD and the general population. Stratified analysis of mortality risks was performed based on sex and psychiatric comorbidities.

RESULTS

PD was associated with a slightly increased mortality risk (MRR, 1.14 [99% CI, 1.11-1.17]). The risk of unnatural death (MRR, 2.83 [99% CI, 2.59-3.10]) was significantly higher among the individuals with PD than among the general population, whereas the risk of overall natural death across all categories was not (MRR, 1.01 [99% CI, 0.98-1.04]). The mortality risk was the highest for suicide (MRR, 4.94 [99% CI, 4.32-5.72]) and was higher in women (MRR, 6.37 [99% CI, 5.25-7.96]) than in men (MRR, 3.77 [99% CI, 3.14-4.64]). Comorbid substance use disorders increased the risk of mortality from natural (MRR, 3.23 [99% CI, 2.59-4.14]) and unnatural (MRR, 9.45 [99% CI, 6.29-17.85]) causes.

CONCLUSION

PD was associated with increased all-cause mortality, especially suicide. Substance use further increased mortality risk in persons with PD. Targeted treatment for substance use and suicide prevention are essential among persons with PD.

All-cause and suicide mortality among people with methamphetamine use disorder: a nation-wide cohort study in Taiwan

BACKGROUND AND AIMS

Although methamphetamine use is a serious public health problem, large-scale cohort studies assessing methamphetamine-related mortality are scant. This study investigated all-cause mortality and suicide methods in people with methamphetamine use disorder.

DESIGN

A cohort record-linkage study using data from Taiwan's National Health Research Institute Database (NHIRD) linked to Taiwan's National Death Certification System.

SETTING

Taiwan.

PARTICIPANTS

A total of 23 248 individuals with methamphetamine use disorder between 1 January 2001 and 31 December 2005.

MEASUREMENTS

The outcome variables included mortality rates and standardized mortality ratios (SMRs) for all causes of death and for each suicide method.

FINDINGS

Compared with the general population, the current cohort had an increased all-cause mortality (SMR = 5.4), with the SMR for unnatural causes (14.8) higher than that for natural causes (7.5). Among all causes of death, suicide had the highest SMR (16.3), followed by neurological diseases (9.7). Among the methods of choice for suicide, drug overdose had the highest SMR (24.9). The incidence of charcoal burning and hanging was significantly higher in men and that of jumping from a high place was significantly higher in women.

CONCLUSION

People in Taiwan with methamphetamine use disorder appear to have a significantly increased all-cause mortality rate compared with the general population, with suicide having the highest contribution, particularly suicide via drug overdose. The methods of choice for suicide revealed distinct patterns between men and women.

Increased medical utilization and psychiatric comorbidity following a new diagnosis of methamphetamine use disorder

BACKGROUND

Evidence of patterns of medical utilization and distribution of comorbidities among individuals using methamphetamine remains limited.

OBJECTIVE

This study aims to investigate changes in medical utilization and comorbidities before and after a diagnosis of methamphetamine use disorder.

METHODS

A total of 3321 cases (79% were male) of methamphetamine use disorder between January 1, 1996, and December 31, 2012, were identified from Psychiatric Inpatient Medical Claims database in Taiwan. Information was collected on demographics, diagnoses, and medical utilizations. The date of newly diagnosed with methamphetamine use disorder was defined as the baseline. Mirror-image study design was used to compare changes in medical utilization and comorbidities between the pre-baseline period (within 1 year before diagnosis) and the post-baseline period (within 1 year after diagnosis). Conditional logistic regression was used to estimate changes in medical utilization and comorbidities.

RESULTS

Most cases (77%) were first identified in a psychiatric department. There is a significant increase (P < .001) in psychiatric admission (odds ratio[OR] = 2.19), psychiatric emergency visits (OR = 1.31), and psychiatric outpatient visits (OR = 1.15) after diagnosis. Multivariable analysis revealed significantly increased risks (P < .001) of non-methamphetamine drug induced mental disorders (adjusted OR[aOR] = 29.47), schizophrenia (aOR = 2.62), bipolar disorder (aOR = 2.14), organic mental disorder (aOR = 1.82), and upper respiratory tract infection (aOR = 2.03) after diagnosis.

CONCLUSIONS

We found significant increases of medical utilization and psychiatric comorbidities after diagnosed with methamphetamine use disorder. These findings may reflect the problem of delayed diagnosis and treatment. Enhancement of early identification of methamphetamine use disorder in general practice is required for early intervention and decreased subsequent morbidities.

[Effect of platelet reactivity on clinical events in patients using bivalirudin in selective percutaneous coronary intervention]

Objective: To investigate the effect of platelet reactivity and other clinical factors on the postoperative 1-year adverse clinical events in patients who underwent selective percutaneous coronary intervention (PCI) anticoagulated with bivalirudin. Methods: This is a multicenter, retrospective and observational study, enrolling 632 patients at high risk of bleeding adjudicated by operators who underwent selective PCI anticoagulated with bivalirudin and had preoperative thrombelastography (TEG) test results in Fuwai Hospital, Northern Theater General Hospital and Xinxiang Central Hospital between January 2017 and August 2018. Platelet reactivity was tested by TEG and adenosine-induced maximal amplitude (MAADP) was recorded. According to MAADP patients were divided into three groups: low on-treatment platelet reactivity (LTPR) group (MAADP<31 mm, n=229), normal on-treatment platelet reactivity (NTPR) group (31 mm≤MAADP≤47 mm, n=207) and high on-treatment platelet reactivity (HTPR) group (MAADP>47 mm, n=196). The endpoints consisted of major adverse cardiovascular and cerebrovascular events (MACCE) and bleeding events. The definition of MACCE was the composite of all-cause mortality, myocardial infarction, intrastent thrombosis, stroke and revascularization. Bleeding events were defined by bleeding academic research consortium (BARC) type 2, 3 and 5 bleeding. Using multivariate Cox regression to analyze the factors of MACCE and bleeding events in patients underwent selective PCI anticoagulated with bivalirudin. Results: A total of 632 patients were finally enrolled in the study with age of (68.3±10.0) years and there were 423 (66.9%) males. All of 632 patients finished one-year follow-up, and 48 (7.6%) patients occurred MACCE and 11 (1.7%) patients occurred bleeding events. There was not statistically significant difference in the incidence of MACCE (8.3% (19/229) vs. 6.3% (13/207) vs.8.2% (16/196), P=0.68) and bleeding events (1.8% (4/229) vs. 2.9% (6/207) vs. 0.5% (1/196), P=0.17) in LTPR, NTPR and HTPR group. Multivariate Cox regression showed that HTPR was not the independent factor of MACCE (HR=1.25, 95%CI 0.67-2.30, P=0.49), and the history of peripheral vessel disease was the independent risk factor of MACCE (HR=2.47, 95%CI 1.19-5.11, P=0.02). LTPR was not the independent factor of bleeding events (HR=1.35, 95%CI 0.39-4.66, P=0.64), and the independent factors of bleeding events were history of peripheral vessel disease (HR=3.95, 95%CI 1.03-15.22, P=0.05) and hemoglobin (HR=0.96, 95%CI 0.93-0.99, P=0.01). Conclusions: In patients undergoing selective PCI anticoagulated with bivalirudin, there is no significant association between platelet reactivity and postoperative 1-year MACCE or bleeding events. History of peripheral vessel disease is an independent risk factor of MACCE, and history of peripheral vessel disease and decreased hemoglobin are independent risk factors of bleeding events.

Incidence and method of suicide mortality in patients with schizophrenia: a Nationwide Cohort Study

PURPOSE

Suicide is a leading cause of death in patients with schizophrenia. This nationwide cohort study investigated the incidence of each suicide method in patients with schizophrenia compared with the general population.

METHODS

In total, records of 174,039 patients with schizophrenia were obtained from the National Health Insurance Research Database in Taiwan from 2001 to 2016. This schizophrenia cohort was linked with the national mortality database, and 26,926 patients died during this follow-up period. Of the deceased, 3033 had died by suicide. Univariate Cox regression was used to estimate the demographic variables associated with suicide. We estimated the difference in the proportion of each suicide method used in patients with schizophrenia compared with the general population. The incidence and standardized mortality ratio (SMR) of each suicide method were calculated and stratified based on sex.

RESULTS

Patients aged 25-34 years exhibited the highest suicide risk. Compared with the general population, patients with schizophrenia were more likely to commit suicide by jumping and drowning and less likely to use charcoal-burning and hanging. Women showed a higher incidence of suicide by drowning and jumping than did men. Comorbidity with substance use disorders (SUDs) was associated with a high suicide SMR (26.9, 95% confidence interval [CI] = 23.4-28.9), particularly for suicide by jumping (61.2, 95% CI = 48.3-76.3).

CONCLUSIONS

Patients with schizophrenia had higher suicide rates for all methods than did the general population. Suicide method differed based on sex. Patients with SUDs exhibit a high SMR for each suicide method and warrant intensive clinical attention.

[The diagnostic performance of galactomannan detection in invasive pulmonary aspergillosis with severe and critically ill influenza]

Objective: To analyze the diagnostic performance of serum and bronchoalveolar lavage fluid (BALF) galactomannan (GM) test in invasive pulmonary aspergillosis(IPA) with severe and critically ill influenza. Methods: A retrospective study was performed for 157 patients with severe and critically ill influenza admitted to the Department of Pulmonary and Critical Care Medicine of the First Affiliated Hospital of Wenzhou Medical University from December 2017 to April 2019.Clinical characteristics and serum and BALF GM values were collected. The patients were divided into an IPA group (n=18) and a non-IPA group (n=139). The definition of IPA modified from AspICU algorithm taken as the gold standard (The corresponding clinical manifestations, imaging manifestations and microbiological diagnostic criteria should be met simultaneously), the performance of serum and BALF GM test and their combination to IPA with influenza were analyzed respectively and receiver operating characteristic curve (ROC) was drawn. Results: A total of 157 cases were enrolled, 95 were critically ill, and the mortality of IPA with influenza was 55.6%(10/18). The APACHE Ⅱ score, PSI score, urea nitrogen, influenza severity (Percentage of critically ill influenza) and invasive ventilator in IPA group were (16±6), (110±31), 10.7 (8.4, 17.8) mmol/L, 88.9% and 66.7%, respectively, which were significantly higher than those in non-IPA group [(10±5), (83±30), 5.2 (3.6, 7.6) mmol/L, 56.8% and 24.5%, P<0.05]. All patients received serum GM test and 32 patients performed BALF GM test at the same time. When the cut-off valve of serum GM test was 0.5 μg/L, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 66.7% (12/18), 95.0% (132/139), 63.2% (12/19) and 95.7% (132/138) respectively. When the cut-off value of BALF GM test was 1.0 μg/L, the sensitivity, specificity, PPV and NPV were 80%(8/10),86.4%(19/22),72.7%(8/11)and 90.5%(19/21)respectively. The BALF GM cut-off value of 0.88 μg/L showed the highest diagnostic efficacy for IPA, for which the sensitivity and specificity were 90%(9/10) and 86.4%(19/22). The areas under the ROC curve of serum GM, BALF GM, and the combination of them were 0.81, 0.85, and 0.94 respectively. The difference was statistically significant (P<0.05) and the combined diagnosis efficiency was higher. Conclusions: Critically ill influenza patients should be alert for IPA. The sensitivity of serum GM test in the diagnosis of IPA with influenza was low, while the NPV was high. The optimum BALF GM cut-off value was 0.88 μg/L. The combination with BALF and serum GM test can improve the diagnostic performance.

Age Effect on Incidence, Physical, and Psychiatric Comorbidity for Sudden Cardiac Death in Schizophrenia: Effet de l'âge sur l'incidence, la comorbidité physique et psychiatrique de la mort cardiaque subite dans la schizophrénie

OBJECTIVE

The pathogenesis of sudden cardiac death may differ between younger and older adults in schizophrenia, but evidence remains scant. This study investigated the age effect on the incidence and risk of the physical and psychiatric comorbidity for sudden cardiac death.

METHODS

Using 2000 to 2016 data from the Taiwan National Health Insurance Research Database and Department of Health Death Certification System, we identified a national cohort of 170,322 patients with schizophrenia, 1,836 of whom had a sudden cardiac death. Standardized mortality ratios (SMRs) were estimated. Hazard ratios and population attributable fractions of distinctive comorbidities for sudden cardiac death were assessed.

RESULTS

The SMRs of sudden cardiac death were all >1.00 across each age group for both sexes, with the highest SMR in male patients aged <35 years (30.88, 95% CI: 26.18-36.18). The fractions of sudden cardiac death attributable to hypertension and congestive heart failure noticeably increased with age. By contrast, the fraction attributable to drug-induced mental disorder decreased with age. Additionally, chronic hepatic disease and sleep disorder increased the risk of sudden cardiac death in patients aged <35 years. Dementia and organic mental disorder elevated the risk in patients aged between 35-54 years. Ischemic heart disease raised the risk in patients aged ≥55 years.

CONCLUSIONS

The risk is increased across the lifespan in schizophrenia, particularly for younger male patients. Furthermore, physical and psychiatric comorbidities have age-dependent risks. The findings suggest that prevention strategies targeted toward sudden cardiac death in patients with schizophrenia must consider the age effect.

High Risk and Trajectories of Physical Illnesses before the Diagnosis of Bipolar Disorder

OBJECTIVE

The authors investigated the distributions and trajectories of physical illnesses preceding the diagnosis of bipolar disorder with comparison to schizophrenia and general populations.

METHODS

Using data from the Taiwan National Health Insurance Research Database entered from 1996 to end of 2012, we identified 13,079 patients newly diagnosed as having bipolar disorder between the age of 13 and 40 years (ie, cases). For each case with bipolar disorder, two age- and sex- and diagnosis year- schizophrenia comparisons (n=26,158)(n=26,158) and four age- and sex-matched comparisons representing the general population (n=52,316)(n=52,316) were randomly selected from the cohort. Multivariate conditional logistic regression analyses were conducted to estimate the risk of physical illness before the diagnosis (index date). Variables exhibiting a powerful association (p<0·001) were retained in the final model.

RESULTS

During the year before diagnosis, patients with newly diagnosed bipolar disorder had a higher risk of numerous physical illnesses across the cardiovascular, respiratory, gastrointestinal, endocrine/metabolic, and musculoskeletal/integument systems compared with those with schizophrenia and the general population. Trends in the risk of specific physical illnesses, mainly hypertension, heart disease, asthma, ulcer disease, hyperlipidemia, and connective tissue disease, were increased across the 3-year prodromal phase of bipolar disorder relative to schizophrenia.

CONCLUSIONS

Intriguingly, physical illnesses before the diagnosis of bipolar disorder are pervasive with higher risk. Moreover, the trajectories of physical illnesses markedly differ from those of schizophrenia before full manifestation.

Incidence and risk factors of sudden cardiac death in bipolar disorder across the lifespan

OBJECTIVE

Data on the incidence and risk factors of sudden cardiac death in patients with bipolar disorder are lacking in the literature.

METHODS

By using data from the Taiwan National Health Insurance Research Database and Department of Health Death Certification System between 2000 and 2016, we conducted a prospective national cohort study to determine the incidence and risk factors of sudden cardiac death in bipolar disorder patients. The study cohort included 46,490 patients with bipolar disorder, 467 of whom experienced sudden cardiac death.

RESULTS

Stratified analyses showed that the standardized mortality ratios (SMRs) of sudden cardiac death were all above 1.00 across each age interval, with the highest SMR in patients aged <30 years (31.96, 95% CI: 20.47-47.55). Notably, hypertension raised the risk of sudden cardiac death in both patients aged <50 years (1.85, 95% CI: 1.23-2.79) and aged ≥50 years (1.44, 95% CI: 1.14-1.83). In addition, venous and lymphatic disorders (1.97, 95% CI: 1.23-3.16), and alcohol use-related disorder (2.34, 95% CI: 1.62-3.38) elevated the risk of sudden cardiac death in patients aged <50 years. Congestive heart failure (1.59, 95% CI: 1.13-2.23) and dementia (1.75, 95% CI: 1.30-2.35) increased the risk of sudden cardiac death in patients aged ≥50 years.

CONCLUSIONS

The risk of sudden cardiac death is remarkably high in bipolar disorder patients across the lifespan. Prevention strategies specific to individuals with bipolar disorder are urgently required.

[Diagnostic performance of pathology, culture and ROSE of lung biopsy for suspected pulmonary infectious diseases]

Objective: To explore the diagnostic performance of CT guided percutaneous lung biopsy (PTLB) with pathology, culture and rapid on-site evaluation (ROSE) in patients with pulmonary infectious diseases. Methods: From January 2016 to June 2018, a retrospective study was implemented in the Department of Pulmonary and Critical Care Medicine of the First Affiliated Hospital of Wenzhou Medical University. Patients who received PTLB, suspected with lung infection were included. The basic information, clinical symptoms, imaging findings, diagnostic methods, complications, and changes in treatment of cases were collected. The diagnostic sensitivity of histopathology, microbial culture, and ROSE were evaluated at the same time. Results: A total of 529 cases were enrolled, including 354 males and 175 females, (59±14) years old in average. Tuberculosis was identified in 197 cases, non-tuberculosis mycobacteria (NTM) pulmonary disease in 8, cryptococcosis in 95, pulmonary aspergillosis in 27, filamentous fungal pneumonia in 3, talaromyces marneffei pulmonary infection in 3 and pulmonary candidiasis in 1, bacterial pneumonia in 39, and pathogen were unknown in 156 cases. A total of 417 cases were submitted for histopathology and microbial culture at the same time, the diagnostic value of pathology and microbial culture were 35.0% (146/417) and 45.6% (190/417), respectively. Combined pathology with microbial culture, the diagnostic value increased to 62.8% (262/417). The diagnostic accuracy of ROSE was 51.8% (71/137). The most common complication of PTLB was pneumothorax 26.1% (138/529). 56.1% (297/529) of the patients received targeted treatment after the diagnosis was confirmed, and 43.9% (232/529) maintained the original treatment. Conclusion: The pathology, microbial culture, and ROSE of PTLB have relative high diagnostic value for pulmonary infectious diseases.

[Plasma relative abundance of epidermal growth factor receptor mutations predicts clinical response to epidermal growth factor receptor-tyrosine kinase inhibitors in patients with advanced lung adenocarcinoma]

Objective: To determine whether relative abundance of epidermal growth factor receptor (EGFR) mutations in plasma predicts clinical response to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in patients with advanced lung adenocarcinoma. Methods: In this prospective study, adult patients with advanced lung adenocarcinoma were enrolled in our hospital from 1 April 2016 to 1 January 2017. EGFR mutations in tumor tissues were detected by ADx-amplification refractory mutation system (ADx-ARMS). EGFR mutations of plasma free tumor DNA were detected by ADx-ARMS and ADx-super amplification refractory mutation system (ADx-SuperARMS) at the same time. Patients with EGFR-mutant in tumor tissues and receiving EGFR-TKIs were finally enrolled. Plasma mutation-positive patients with both methods were high abundance group.Patients with positive mutations by ADx-SuperARMS but negative by ADx-ARMS were medium abundance group. Mutation-negative patients with both methods were recognized as low abundance group. The correlation between EGFR mutation abundance and clinical response to EGFR-TKIs were analyzed. Results: Among 71 patients enrolled, 42 harbored EGFR mutations in plasma were detected by ADx-ARMS, while 53 were found by ADx-SuperARMS.There were 42 patients in high abundance group, 11 in medium group while the other 18 in low group. The objective response rates (ORRs) were 69.0%, 7/11 and 10/18 in high, medium and low groups, respectively. The difference was significant between high and low abundances groups (P=0.006). Median progression-free survival (PFS) in high, medium and low groups were 11.0, 8.5 and 9.0 monthes, respectively (P<0.001). In patients with tumor 19-Del, the ORRs were 70.4%, 5/7 and 6/11 in high, medium and low abundance groups, respectively. The median PFS of high abundance group was significantly longer than the other two groups (12.0 monthes vs 9.0, 9.0 monthes). As to subjects with L858R mutation, the ORRs were 10/15, 2/4 and 3/6, respectively, with median PFS 9.6, 5.5 and 9.5 monthes. Conclusions: The relative abundance of EGFR mutations in plasma predicts clinical response to EGFR-TKIs in patients with advanced lung adenocarcinoma. The higher the mutation abundance is, the better the efficacy of EGFR-TKIs is.

[Diagnostic performance of T-SPOT.TB on peripheral blood in combination with adenosine deaminase on pleural fluid for the diagnosis of tuberculous pleurisy within different age group]

Objective: To evaluate the performance of T cell enzyme-linked immuno-spot assay (T-SPOT) on peripheral blood in combination with adenosine deaminase (ADA) on pleural fluid for diagnosis of tuberculous (TB) pleurisy within different age groups. Methods: The data of patients with pleural effusion from the Department of Pulmonary and Critical Care Medicine of the First Affiliated Hospital of Wenzhou Medical University from April 2012 to November 2016 were retrospectively analyzed, and the diagnoses of these patients were histopathologically confirmed through medical thoracoscopy. The cases who had confirmed diagnosis, in the same time, received peripheral blood T-SPOT.TB were enrolled. The performance of peripheral blood T-SPOT.TB in combination with pleural fluid ADA on diagnosing TB pleurisy in the younger patients (16-59 years old) and elderly patients (≥60 years old) were analyzed respectively. The sensitivity, specificity and the receiver operating characteristic (ROC) curve were adopted for statistical analysis. Results: A total of 448 cases were finally enrolled, 341(76.1%) confirmed with TB pleurisy, 224 males, 117 females, (47±19) years old; and 107 (23.9%) classified as non-TB pleurisy, 65 males, 42 females, (61±14) years old. There were 285 cases who were classified as younger group, and the other 163 cases were classified as elderly group. The sensitivity and specificity of peripheral blood T-SPOT.TB were 85.4% (204/239) and 71.7% (33/46) in the younger patients, 76.5% (78/102) and 59.0% (36/61) respectively in the elderly patients. The sensitivity of peripheral blood T-SPOT.TB in the younger patients was significantly higher than that in the elderly patients (P=0.047). The sensitivity and specificity were 99.2% and 95.7% in combination with peripheral blood T-SPOT.TB and pleural fluid ADA respectively in the younger patients. The area under ROC curve (AUC) of T-SPOT.TB in the younger patients was 0.833, AUC of T-SPOT.TB combined with ADA was 0.911. The combination test of 2 tests had the sensitivity of 96.1% and the specificity of 90.2% respectively in the elderly patients. The AUC of T-SPOT.TB in the elderly patients was 0.747, AUC of T-SPOT.TB combined with ADA was 0.911. Conclusion: Peripheral blood T-SPOT.TB combined with pleural fluid ADA can improve the diagnostic performance for TB pleurisy with different ages, especially for elderly patients who can't tolerate pleural biopsy.

Cloning and characterization of a farnesyl pyrophosphate synthase from Matricaria recutita L. and its upregulation by methyl jasmonate

Matricaria recutita (L.), commonly known as chamomile, is one of the most valuable medicinal plants because it synthesizes a large number of pharmacologically active secondary metabolites known as α-bisabolol and chamazulene. Although the plant has been well characterized in terms of chemical constituents of essential oil as well as pharmacological properties, little is known about the genes responsible for biosynthesis of these compounds. In this study, we report a new full-length cDNA encoding farnesyl diphosphate synthase (FPS), a key enzyme in the pathway of biosynthesis of isoprenoids, from M. recutita. The cDNA of MrFPS comprises 1032 bp and encodes 343 amino acid residues with a calculated molecular mass of 39.4 kDa. The amino acid sequence homology and phylogenetic analysis indicated that MrFPS belongs to the plant FPS super-family and is closely related to FPS from the Asteraceae family. Expression of the MrFPS gene in Escherichia coli yielded FPS activity. Using real-time quantitative PCR, the expression pattern of the MrFPS gene was analyzed in different tissues of M. recutita as well as in response to methyl jasmonate. The expression analysis demonstrated that MrFPS expression varies in different tissues (with maximal expression in flowers and stems) and was significantly elevated in response to methyl jasmonate. This study will certainly enhance our understanding of the role of MrFPS in the biosynthesis and regulation of valuable secondary metabolites in M. recutita at a molecular level.

Molecular cloning and characterization of the full-length Hsp90 gene from Matricaria recutita

Heat shock protein 90 (Hsp90) is one of the most abundant and conserved chaperone proteins and plays important roles in plant growth and responses to environmental stimuli. However, little is known regarding the sequence and function of Hsp90s in Matricaria recutita. In the present study, we cloned the full-length cDNA sequence of the hsp90 gene from this species. Using rapid amplification of cDNA ends technologies with 2 degenerate primers that were designed based on the hsp90 gene sequence from other members of Asteraceae, we isolated and characterized an Hsp90 homolog gene from M. recutita (Mr-Hsp90). The full-length Mr-hsp90 cDNA sequence, containing 2097 base pairs, encodes a protein of 698 amino acids. Based on amino acid sequence identity, Mr-Hsp90 showed high similarity to other cloned Hsp90 proteins. The Mr-Hsp90 protein was closely clustered with the Lactuca sativa in a phylogenetic tree. These results indicate that the cloned sequence of Mr-Hsp90 is a member of the Hsp90 family, which is reported for the first time in M. recutita. Next, we conducted a salt stress experiment to determine the protein's function under salt stress conditions. Survival of chamomile seedlings subjected to heat-shock pretreatment was significantly increased compared with groups that had not undergone heat-shock pretreatment in a salt stress environment. This indicates that Mr-Hsp90 plays an important role in the salt resistance of chamomile seedlings.

Increased levels of tissue plasminogen activator antigen and factor VIII activity in nonvalvular atrial fibrillation: relation to predictors of thromboembolism

INTRODUCTION

Given that nonvalvular atrial fibrillation (AF)-associated stroke can be either cardioembolic or atherothrombotic, we investigated the relationships between nonvalvular AF and hemostatic factors reflecting intrinsic thrombogenic and atherogenic potentials (tissue plasminogen activator [t-PA] antigen, plasminogen activator inhibitor-1, and factor VIII activity). We also evaluated the clinical applicability of these hemostatic factors by examining whether AF subjects with established clinical or echocardiographic predictors of thromboembolism had higher levels of these factors.

METHODS AND RESULTS

Of the 3,212 participants of a Chinese population-based study, 53 subjects (1.7%) with AF were identified. Among the hemostatic factors measured, t-PA antigen (median 12.8 vs 8.1 ng/mL; P < 0.01) and factor VIII activity (median 155% vs 133%; P < 0.05) were significantly higher in AF subjects after adjustment for age and sex. In multivariate analysis, features independently associated with t-PA antigen levels were AF, sex, body mass index, systolic blood pressure, total cholesterol, triglycerides, and left ventricular systolic dysfunction. Features independently associated with factor VIII activity levels included AF, age, and total cholesterol. Levels of both t-PA antigen and factor VIII activity were primarily elevated in AF subjects with predictors of thromboembolism (age > 75 years, hypertension, diabetes, and left ventricular systolic dysfunction), whereas in AF subjects with no thromboembolic predictors, plasma levels of hemostatic factors examined were similar to those without AF.

CONCLUSION

We demonstrated that nonvalvular AF was independently associated with increased peripheral levels of t-PA antigen and factor VIII activity. Levels of both hemostatic factors were primarily elevated in AF subjects with predictors of thromboembolism. Whether these hemostatic factors are independently predictive of future thromboembolic events in AF patients requires further investigation.

A growth curve analysis of stress and adolescent drug use

The purpose of this paper is to describe and examine one pathway by which adolescent drug use increases during early and mid-adolescence. It draws upon recent research on adolescent stress, drug use, and family processes to describe an important stage of the life course. A chief principle underlying the proposed pathway is that the cumulative effect of stressful life experiences over time can lead to a steeper escalation of drug use in adolescence. Furthermore, based on previous stress research, we propose that this effect may be moderated by factors such as sex, income, family attachment, self-esteem, and mastery. Using 4 years of panel data from the Family Health Study (n = 651 adolescents ages 11-14 during Year 1), we estimate a hierarchical growth curve model that examines the time-varying effects of stressful life events and peer relations on drug use. The results indicate that experiencing a high number of life events over time is related to a significant "growth" of drug use, even after controlling for "growth" due to age or peer relations. In addition, this relationship is moderated by family attachment; high levels of attachment serve to diminish this growth significantly.

Parental substance use disorder, mediating variables and adolescent drug use: a non-recursive model

AIMS

To develop and test a non-recursive model that examines the effects of parental psychoactive substance use disorder (PSUD) on the reciprocal relationships among stressful life events, family attachment, peer drug use and adolescent drug use.

DESIGN

A 3-year prospective cohort study followed adolescents from three types of families defined by a parental diagnosis of a psychiatric disorder.

SETTING

A large metropolitan area in the upper Midwestern United States.

PARTICIPANTS

Seven hundred and seventy-seven 10-16-year-old adolescents from three groups of families: 214 who resided in families in which a parent was diagnosed with PSUD, 181 who resided in families in which a parent was diagnosed with an affective disorder (but no co-morbid PSUD), and 382 who resided in families in which both parents were free of any diagnosable disorder.

MEASUREMENTS

Psychiatric disorder was defined by the Structured Clinical Interview for DSM-III-R (SCID). Two follow-up interviews of adolescent respondents were used to measure stressful life events via the Junior High Life Experiences Survey, family attachment via FACES-III and a child-parent strain index, peer drug use, and two self-reported drug use scales designed to measure past-year alcohol use and illicit drug use (e.g. marijuana, cocaine, inhalants).

FINDINGS

Nested structural equation models with latent variables revealed that adolescents from PSUD families were at heightened risk of stressful life events, peer drug use, attenuated family attachments and drug use during the first follow-up period. In turn, peer drug use was strongly associated with drug use during the second follow-up period. However, drug use during the first follow-up also led to greater peer drug use and attenuated family attachment during the second follow-up period. The findings support a non-recursive model describing relations among adolescent drug use, peer drug use and family attachment.

CONCLUSIONS

Parental psychoactive substance use disorder puts adolescents at significant risk of becoming embedded in a cycle of drug use, associations with drug using peers, and poor family relations.

Stressful life events and adolescent substance use and depression: conditional and gender differentiated effects

Stressful life circumstances have myriad influences on human health and behavior. Early research focused on the variable distribution of stress and its effects by socioeconomic status, race, and gender. More recent research indicates that variation by age is also an important consideration. For example, adolescent reactions to stressful life events are often inconsistent with adult reactions to similar life situations and transitions. Moreover, since most studies assess only a single outcome--usually depression--they risk classification bias since analyses exclude other potential stress-related outcomes. This paper assesses the gender distinct effects of stressful life events on two outcomes among adolescents, substance use and depressive symptoms. The results of a second-order regression model indicate that life events affect female, but not male, depressive symptoms, especially when self-esteem is low or mastery is high. Furthermore, life events affect substance use when peer drug use is high, or when parental support is low, but this latter effect is limited to female adolescents.

Changes in network characteristics and HIV risk behavior among injection drug users

Studies indicate that HIV risk behaviors vary greatly among injection drug users (IDUs). The source of such variation is often ascribed to individual differences, but much of it is due to how IDUs are grouped into social networks. Nevertheless, given the turbulent and uncertain lives led by many IDUs, it would not be surprising if their social networks changed substantially over time. We used data from a study of the social networks of IDUs in Chicago and Washington, DC, to examine changes in individual behavior and network characteristics over time. The results indicated few changes in standard network measures, such as density of ties or network size, over time. However, specific network change measures, that is, indicators of movement into and out of networks, showed significant movement of network members over time. Moreover, movement of members into a network significantly predicted a higher likelihood of risky injection drug use over time. We suggest that these movements are indicative of a lack of a stable resource base among IDU networks.

Effect of parental mental health status on adolescents' dietary behaviors

PURPOSE

The purpose of this study was to explore whether adolescents of substance-abusing and depressed parents were more likely to have poor dietary behaviors than those in the health comparison families.

METHODS

The sample consisted of 841 adolescents in families of substance-abusing parents, depressed parents, and parents without a diagnosable psychiatric disorder. All adolescents were given a food frequency questionnaire.

RESULTS

Adolescents whose parents had substance abuse disorder had lower intakes of fruits and higher intakes of high fat foods, and also ate more frequently at fast-food restaurants and purchased more snacks. Adolescents whose parents were depressed had lower intakes of all food groups. Mother's mental health status impacted more on adolescents' dietary behaviors than did the father's mental health status.

CONCLUSION

This research suggests that at-risk behaviors among youth of psychiatrically impaired parents may extend to food behaviors.

A nitrogen starvation-induced dormant G0 state in fission yeast: the establishment from uncommitted G1 state and its delay for return to proliferation

Fission yeast cells either remain in the mitotic cell cycle or exit to meiotic sporulation from an uncommitted G1 state dependent on the presence or absence of nitrogen source in the medium (Nurse and Bissett, 1981). We examined how heterothallic haploid cells, which cannot sporulate, behave under nitrogen-starvation for longer than 25 days at 26 degrees C. These cells were shown to enter a stable state (designated the dormant G0) with nearly full viability. Maintaining the dormant cells required glucose, suggesting that the cells remained metabolically active although cell division had ceased. They differed dramatically from mitotic and uncommitted G1 cells in heat resistance, and also in cytoplasmic and nuclear morphologies. After nitrogen replenishment, the initial responses of dormant G0 cells were investigated. The kinetics for reentry into the proliferative state were delayed considerably, and the changes in cell shape were enhanced particularly for those recovering from extended nitrogen starvation. A part of the delay could be accounted for by the duration of nuclear decondensation and cell elongation for the first cell division.

Molecular characterization of the yeast meiotic regulatory gene RIM1

In the yeast Saccharomyces cerevisiae, genetic studies suggest that the RIM1 gene encodes a positive regulator of meiosis. rim1 mutations cause reduced expression of IME1, which is required for expression of many meiotic genes, and thus lead to a partial defect in meiosis and spore formation. We report the sequence of RIM1 and functional analysis of its coding region. The RIM1 gene product (RIM1) contains three regions similar to C2H2 zinc fingers. Serine substitutions for cysteine in each of the putative zinc fingers abolish RIM1 function. The carboxyl-terminus of RIM1 is enriched in acidic amino acids and is required for full RIM1 activity. RIM1 also contains two putative cAMP-dependent protein kinase (cAPK) phosphorylation sites. At one site, substitution of alanine for serine does not affect RIM1 activity; at the other site, this substitution impairs activity. This analysis of RIM1 suggests that the protein may function as a transcriptional activator. We have used the cloned RIM1 gene to create a complete rim1 deletion. This null allele, like previously isolated rim1 mutations, causes a partial meiotic defect. In addition to RIM1, maximum IME1 expression requires the MCK1 and IME4 gene products. Defects associated with rim1, mck1, and ime4 mutations in expression of a meiotic reporter gene (ime2-lacZ) and in sporulation are additive. These findings suggest that RIM1 acts independently of MCK1 and IME4 to stimulate IME1 expression.

Identification of functionally related genes that stimulate early meiotic gene expression in yeast

Meiosis and spore formation in the yeast Saccharomyces cerevisiae are associated with increased expression of sporulation-specific genes. One of these genes, IME2, encodes a putative protein kinase that is a positive regulator of other sporulation-specific genes. We have isolated mutations that cause reduced expression of an ime2-lacZ fusion gene. We found mutations in IME1, a known positive regultor of IME2, and MCK1, a known positive regulator of IME1. We also isolated recessive mutations in 12 other genes, which we designate RIM (Regulator of IME2) genes. Our analysis indicates that the defects in rim1, rim8, rim9 and rim13 mutants are a consequence of diminished IME1 expression and can be suppressed by expression of IME1 from the heterologous ACT1 promoter. These rim mutations also reduced expression of an ime1-HIS3 fusion, in which the HIS3 gene is expressed from the IME1 promoter, and caused reduced levels of IME1 RNA. Although the rim1, rim8, rim9 and rim13 mutant phenotypes are similar to those of mck1 mutants, we found that the defects in ime2-lacZ expression and sporulation of the mck1 rim double mutants were more severe than either single mutant. In contrast, the defects of the rim rim double mutants were similar to either single mutant. The rim1, rim8, rim9 and rim13 mutants also display slow growth at 17 degrees and share a smooth colony morphology that is not evident in mck1 mutants or isogenic wild-type strains. We suggest that RIM1, RIM8, RIM9 and RIM13 encode functionally related products that act in parallel to MCK1 to stimulate IME1 expression.

Role of IME1 expression in regulation of meiosis in Saccharomyces cerevisiae

Two signals are required for meiosis and spore formation in the yeast Saccharomyces cerevisiae: starvation and the MAT products a1 and alpha 2, which determine the a/alpha cell type. These signals lead to increased expression of the IME1 (inducer of meiosis) gene, which is required for sporulation and sporulation-specific gene expression. We report here the sequence of the IME1 gene and the consequences of IME1 expression from the GAL1 promoter. The deduced IME1 product is a 360-amino-acid protein with a tyrosine-rich C-terminal region. Expression of PGAL1-IME1 in vegetative a/alpha cells led to moderate accumulation of four early sporulation-specific transcripts (IME2, SPO11, SPO13, and HOP1); the transcripts accumulated 3- to 10-fold more after starvation. Two sporulation-specific transcripts normally expressed later (SPS1 and SPS2) did not accumulate until PGAL1-IME1 strains were starved, and the intact IME1 gene was not activated by PGAL1-IME1 expression. In a or alpha cells, which lack alpha 2 or a1, expression of PGAL1-IME1 led to the same pattern of IME2 and SPO13 expression as in a/alpha cells, as measured with ime2::lacZ and spo13::lacZ fusions. Thus, in wild-type strains, the increased expression of IME1 in starved a/alpha cells can account entirely for cell type control, but only partially for nutritional control, of early sporulation-specific gene expression. PGAL1-IME1 expression did not cause growing cells to sporulate but permitted efficient sporulation of amino acid-limited cells, which otherwise sporulated poorly. We suggest that IME1 acts primarily as a positive regulator of early sporulation-specific genes and that growth arrest is an independent prerequisite for execution of the sporulation program.

Isolation and characterization of the Escherichia coli mutL gene product

The Escherichia coli mutL gene product has been purified to near homogeneity from an overproducing clone. The mutL locus encodes a polypeptide of 70,000 daltons as determined by denaturing gel electrophoresis. The native molecular weight of MutL protein as calculated from the sedimentation coefficient of 5.5 S and Stokes radius of 61 A is 139,000 daltons, indicating that MutL exists as a dimer in solution. In addition to its ability to complement methyl-directed DNA mismatch repair in mutL-deficient cell-free extracts, DNase I protection experiments demonstrate that the purified MutL protein interacts with the MutS-heteroduplex DNA complex in the presence of ATP.

The impact of changing methods of data collection on the reliability of self-reported drug use of adolescents

The purpose of this study is to determine the impact of different modes of data collection on the reliability of self-reported drug use of adolescents in a panel study. Adolescents were assigned to four groups based upon the ways they chose to respond to the survey instruments: 1) mailed questionnaires in both years, 2) survey interview in one year and mailed questionnaire in the next year, 3) mailed questionnaire in one year and survey interview in the following year, and 4) survey interview in both years. The quality of the self-reported data was examined in terms of return rates, missing data, internal consistency, and consistency of reported information over time. No significant differences were found between groups, suggesting that the mode of data collection does not affect the reliability of adolescents' self-reports of substance use.

Gap formation is associated with methyl-directed mismatch correction under conditions of restricted DNA synthesis

A covalently closed, circular heteroduplex containing a G-T mismatch and a single hemimethylated d(GATC) site is subject to efficient methyl-directed mismatch correction in Escherichia coli extracts when repair DNA synthesis is severely restricted by limiting the concentration of exogenously supplied deoxyribonucleoside-5'-triphosphates or by supplementing reactions with chain-terminating 2',3'-dideoxynucleoside triphosphates. However, repair under these conditions results in formation of a single-strand gap in the region of the molecule containing the mismatch and the d(GATC) site. These findings indicate that repair DNA synthesis required for methyl-directed correction can initiate in the vicinity of the mispair, and they are most consistent with a repair reaction involving 3'----5' excision (or strand displacement) from the d(GATC) site followed by 5'----3' repair DNA synthesis initiating in the vicinity of the mismatch.

Mismatch-containing oligonucleotide duplexes bound by the E. coli mutS-encoded protein

The binding of the mutS gene product, a protein involved in at least two E. coli mismatch correction pathways, to a series of synthetic DNA duplexes containing mismatches or mismatch analogues of the purine/pyrimidine type was studied in order to establish whether a correlation exists between the recognition of these mispairs and the efficiency of their correction in vivo. Experiments using nitrocellulose filter binding or band-shift assays revealed that duplexes containing a G/T mismatch or its analogues I/T and DI/T were bound by the protein with affinities correlating to the efficiency of their repair in vivo. In contrast, the A/C mismatch, contained within the same sequence, was bound only poorly, despite being efficiently corrected in vivo. The analogues of the A/C mispair, uncorrected in vivo, were not detectably bound under the conditions of these assays.

Mispair specificity of methyl-directed DNA mismatch correction in vitro

To evaluate the substrate specificity of methyl-directed mismatch repair in Escherichia coli extracts, we have constructed a set of DNA heteroduplexes, each of which contains one of the eight possible single base pair mismatches and a single hemimethylated d(GATC) site. Although all eight mismatches were located at the same position within heteroduplex molecules and were embedded within the same sequence environment, they were not corrected with equal efficiencies in vitro. G-T was corrected most efficiently, with A-C, C-T, A-A, T-T, and G-G being repaired at rates 40-80% of that of the G-T mispair. Correction of each of these six mispairs occurred in a methyl-directed manner in a reaction requiring mutH, mutL, and mutS gene products. C-C and A-G mismatches showed different behavior. C-C was an extremely poor substrate for correction while repair of A-G was anomalous. Although A-G was corrected to A-T by the mutHLS-dependent, methyl-directed pathway, repair of A-G to C-G occurred largely by a pathway that is independent of the methylation state of the heteroduplex and which does not require mutH, mutL, or mutS gene products. Similar results were obtained with a second A-G mismatch in a different sequence environment suggesting that a novel pathway may exist for processing A-G mispairs to C-G base pairs. As judged by DNase I footprint analysis, MutS protein is capable of recognizing each of the eight possible base-base mismatches. Use of this method to estimate the apparent affinity of MutS protein for each of the mispairs revealed a rough correlation between MutS affinity and efficiency of correction by the methyl-directed pathway. However, the A-C mismatch was an exception in this respect indicating that interactions other than mismatch recognition may contribute to the efficiency of repair.

Requirement for d(GATC) sequences in Escherichia coli mutHLS mismatch correction

The involvement of d(GATC) sequences in Escherichia coli DNA mismatch correction was ascertained by analyzing in vitro repair efficiencies of a series of related, covalently closed circular DNA heteroduplexes that contained from zero to four d(GATC) sites. A heteroduplex with four d(GATC) sites was repaired with high efficiency by extracts of E. coli, whereas no significant correction occurred on a closely related molecule lacking such sequences. Heteroduplexes containing one or two d(GATC) sites were corrected at rates between 10% and 93% of that observed for the four-site molecule, but repair efficiency did not correlate in a simple way with the number of sites present. The methylation state at a single d(GATC) sequence was sufficient to direct strandedness of repair, and correction of heteroduplexes containing one or more d(GATC) sites required functional mutH, mutL, and mutS gene products. In addition, DNA repair synthesis dependent on mutH and mutS also required the presence of at least one d(GATC) site. Although mismatch correction was not observed on a covalently closed circular heteroduplex lacking a d(GATC) sequence, such molecules were subject to strand-specific repair if they contained a strand-specific single-strand break. However, this correction reaction did not require mutH, mutL, mutS, or uvrD gene products. Consequently, we have concluded that d(GATC) sequences are directly involved in mismatch correction mediated by the mutHLS system.

Escherichia coli mutS-encoded protein binds to mismatched DNA base pairs

The Escherichia coli mutS gene product is involved in mismatch correction in this organism. We have purified a biologically active form of the 97,000 Mr protein to near homogeneity from an overproducing strain. Enzymatic and chemical protection ("footprinting") experiments have demonstrated that mutS-encoded protein specifically binds to DNA regions containing a single base-pair mismatch. The protein displayed variable affinity for the limited set of mismatches tested (G-T greater than G-A approximately equal to A-C greater than T-C).

A light-scattering study of the effect of calcium chloride on the molecular weight of Busycon hemocyanin

Solutions of Busycon canaliculatum have been studied by light scattering. In 0.05 M Trizma buffer +0.1 M NaCl at pH 7.0 at 14 degrees, the weight-average molecular weight is 8.9 X 10(6). In the presence of added CaCl2 (0.02 M), the molecular weight of the protein increases to 10.7 X 10(6), and the second virial coefficient is reduced. At pH 9.95, the molecular weights with and without 0.02 M CaCl2, are 3.7 X 10(6) and 1.3 X 10(6), respectively; and the effect of Ca++ in reducing the second virial coefficient is much greater than at pH 7.0. These results can be understood on the basis that at pH 7.0, ca++ increases the association of hemocyanin, by binding and intermolecular linkage through the carboxyl groups of protein side chains. At pH 9.95, amino groups are deprotonated and therefore also become available for Ca++ binding. The relative effect of Ca++ in enhancing the association of hemocyanin therefore becomes greater at the higher pH.