bluuebunny/crossref_metadata_2025 huggingface dataset:
CCAAT/Enhancer Binding Protein Homologous Protein (DDIT3) Induces Osteoblastic Cell Differentiation
Authors: Pereira Renata C. , Delany Anne M. , Canalis Ernesto
Published: December 2003

CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP/DDIT3), a member of the C/EBP family of transcription factors, plays a role in cell survival and differentiation. CHOP/DDIT3 binds to C/EBPs to form heterodimers that do not bind to consensus Cebp sequences, acting as a dominant-negative inhibitor. CHOP/DDIT3 blocks adipogenesis, and we postulated it could induce osteoblastogenesis. We investigated the effects of constitutive CHOP/DDIT3 overexpression in murine ST-2 stromal cells transduced with retroviral vectors. ST-2 cells differentiated toward osteoblasts, and CHOP/DDIT3 accelerated and enhanced the appearance of mineralized nodules, and the expression of osteocalcin and alkaline phosphatase mRNAs, particularly in the presence of bone morphogenetic protein-2. CHOP/DDIT3 overexpression opposed adipogenesis, and did not cause substantial changes in cell number. CHOP/DDIT3 overexpression did not modify C/EBPα or -β mRNA levels but decreased C/EBPδ after 24 d of culture. Electrophoretic mobility shift and supershift assays demonstrated that overexpression of CHOP/DDIT3 decreased the binding of C/EBPs to their consensus sequence by interacting with C/EBPα and -β, confirming its dominant-negative role. In addition, CHOP/DDIT3 enhanced bone morphogenetic protein-2/Smad signaling. In conclusion, CHOP/DDIT3 enhances osteoblastic differentiation of stromal cells, in part by interacting with C/EBPα and -β and also by enhancing Smad signaling.
Identification and Characterization of Two Parathyroid Hormone-Like Molecules in Zebrafish
Authors: Gensure Robert C. , Ponugoti Bhaskar , Gunes Yasemin , Papasani Madhusudhan R. , Lanske Beate , Bastepe Murat , Rubin David A. , Jüppner Harald
Published: December 2003

Zebrafish (Danio rerio) have receptors homologous to the human PTH (hPTH)/PTHrP receptor (PTH1R) and PTH-2 receptor (PTH2R) and an additional receptor (PTH3R) with high homology to the PTH1R. To find natural ligands for zPTH1R and zPTH3R, we searched the zebrafish genomic database and discovered two distinct regions that, when translated (zPTH1 and zPTH2), showed high homology to hPTH. Isolation of cDNAs and determination of the intron/exon boundaries revealed genomic structures which were similar to known PTHs. Peptides consisting of the first 34 amino acids after the pre- and prosequences of the zebrafish PTHs (zPTHs) were synthesized and were shown to be fully active at the hPTH1R. zPTH2(1–34) was, however, approximately 30-fold less potent at the zPTH1R than hPTH(1–34), hPTHrP(1–36), and zPTH1(1–34). When tested with zPTH3R, zPTH1(1–34) and hPTHrP(1–36) showed similar potencies, whereas the potency of zPTH2(1–34) was moderately (3-fold) reduced. To determine whether other fishes have multiple PTHs, we searched the genomic database of the Japanese pufferfish (Takifugu rubripes) and identified zPTH1 and zPTH2 homologs. Phylogenetic analysis showed that PTHs from zebrafish and pufferfish are more closely related to each other than to known mammalian PTH homologs or to PTHrP and tuberoinfundibular peptide of 39 residues. This is consistent with evolution of two teleost PTH-like peptides occurring after the evolutionary divergence between fishes and mammals. Overall, the PTH system appears more complex in fishes than in mammals, providing evidence of continued evolution in nontetrapod species. The availability of multiple forms of fish PTH and their receptors provide additional tools for PTH ligand/receptor structure-function studies.
Estrogen Replacement Reverses the Hepatic Steatosis Phenotype in the Male Aromatase Knockout Mouse
Authors: Hewitt Kylie N. , Pratis Kyriakos , Jones Margaret E. E. , Simpson Evan R.
Published: December 2003

The aromatase knockout (ArKO) mouse cannot synthesize endogenous estrogens due to a disruption to the Cyp19 gene. Previously we have shown both male and female ArKO mice have an age progressive obese phenotype and a sexually dimorphic disruption to hepatic cholesterol and triglyceride homeostasis. Only ArKO males have elevated hepatic triglyceride levels leading to hepatic steatosis partly due to an increase in expression of enzymes involved in de novo lipogenesis and transporters involved in fatty acid uptake. In this study ArKO males were treated with 17β-estradiol (3 μg/ kg·d) at 18 wk old for 6 wk. Wild-type controls were not treated, and ArKO controls received vehicle oil injections. Estrogen replacement reverses the previously reported obese and fatty liver phenotypes; this was achieved by reductions in gonadal, visceral, and brown adipose tissue weights and significantly decreased hepatic triglyceride levels. Estrogen deficiency led to a significant up-regulation of hepatic fatty acid synthase expression, which was reduced with 17β-estradiol replacement, although not quite reaching significance. Acetyl Coenzyme A carboxylase α mRNA expression showed no significant changes. Expression of transcripts encoding adipocyte differentiated regulatory protein, a fatty acid transporter, was significantly elevated in estrogen-deficient males, and 17β-estradiol replacement significantly reduced these levels. Scavenger receptor class b type 1 showed no significantly changes. This study reveals that the previously reported disruption to triglyceride homeostasis in estrogen-deficient males can be reversed with 17β-estradiol treatment, indicating an important role for estrogen in maintaining triglyceride and fatty acid homeostasis in males.
Flow regulates arterial-venous differentiation in the chick embryo yolk sac
Authors: le Noble Ferdinand , Moyon Delphine , Pardanaud Luc , Yuan Li , Djonov Valentin , Matthijsen Robert , Bréant Christiane , Fleury Vincent , Eichmann Anne
Published: December 2003

Formation of the yolk sac vascular system and its connection to the embryonic circulation is crucial for embryo survival in both mammals and birds. Most mice with mutations in genes involved in vascular development die because of a failure to establish this circulatory loop. Surprisingly,formation of yolk sac arteries and veins has not been well described in the recent literature. Using time-lapse video-microscopy, we have studied arterial-venous differentiation in the yolk sac of chick embryos. Immediately after the onset of perfusion, the yolk sac exhibits a posterior arterial and an anterior venous pole, which are connected to each other by cis-cis endothelial interactions. To form the paired and interlaced arterial-venous pattern characteristic of mature yolk sac vessels, small caliber vessels of the arterial domain are selectively disconnected from the growing arterial tree and subsequently reconnected to the venous system, implying that endothelial plasticity is needed to fashion normal growth of veins. Arterial-venous differentiation and patterning are controlled by hemodynamic forces, as shown by flow manipulation and in situ hybridization with arterial markers ephrinB2 and neuropilin 1, which show that expression of both mRNAs is not genetically determined but plastic and regulated by flow. In vivo application of ephrinB2 or EphB4 in the developing yolk sac failed to produce any morphological effects. By contrast, ephrinB2 and EphB4 application in the allantois of older embryos resulted in the rapid formation of arterial-venous shunts. In conclusion, we show that flow shapes the global patterning of the arterial tree and regulates the activation of the arterial markers ephrinB2 and neuropilin 1.
Hedgehog-GLI signaling regulates the behavior of cells with stem cell properties in the developing neocortex
Authors: Palma Verónica , Altaba Ariel Ruiz i
Published: December 2003

Stem cells are crucial for normal development and homeostasis, and their misbehavior may be related to the origin of cancer. Progress in these areas has been difficult because the mechanisms regulating stem cell lineages are not well understood. Here, we have investigated the role of the SHH-GLI pathway in the developing mouse neocortex. The results show that SHH signaling endogenously regulates the number of embryonic and postnatal mouse neocortical cells with stem cell properties, and controls precursor proliferation in a concentration-dependent manner in cooperation with EGF signaling. These findings identify a crucial mechanism for the regulation of the number of cells with stem cell properties that is unexpectedly conserved in different stem cell niches.
The exocyst component Sec5 is required for membrane traffic and polarity in theDrosophilaovary
Authors: Murthy Mala , Schwarz Thomas L.
Published: December 2003

The directed traffic of membrane proteins to the cell surface is crucial for many developmental events. We describe the role of Sec5, a member of the exocyst complex, in directed membrane traffic in the Drosophilaoocyte. During oogenesis, we find that Sec5 localization undergoes dynamic changes, correlating with the sites at which it is required for the traffic of membrane proteins. Germline clones of sec5 possess defects in membrane addition and the posterior positioning of the oocyte. Additionally,the impaired membrane trafficking of Gurken, the secreted ligand for the EGF receptor, and Yolkless, the vitellogenin receptor, results in defects in dorsal patterning and egg size. However, we find the cytoskeleton to be correctly oriented. We conclude that Sec5 is required for directed membrane traffic, and consequently for the establishment of polarity within the developing oocyte.
Dispersal of Golgi matrix proteins during mitotic Golgi disassembly
Authors: Puri Sapna , Telfer Helena , Velliste Meel , Murphy Robert F. , Linstedt Adam D.
Published: December 2003

During mitosis, the mammalian Golgi disassembles into numerous vesicles and larger membrane structures referred to as clusters or remnants. Following mitosis, the vesicles and clusters reassemble to form an intact Golgi in each daughter cell. One model of Golgi biogenesis states that Golgi matrix proteins remain assembled in mitotic clusters and then serve as a template for Golgi reassembly. To test this idea, we performed a 3D-computational analysis of mitotic cells to determine the extent to which these proteins remain in mitotic clusters. As a control we used brefeldin A-induced Golgi disassembly which causes dispersal of Golgi enzymes, but leaves matrix proteins in remnant structures. Unlike brefeldin A-treated cells, in which matrix proteins were clearly sorted from non-matrix proteins, we observed extensive dispersal of matrix proteins in metaphase cells with no evidence of differential sorting of these proteins from other Golgi proteins. The extensive disassembly of matrix proteins argues against their participation in a stable template and supports a self-assembly mode of Golgi biogenesis.
Electrical stimulation directly induces pre-angiogenic responses in vascular endothelial cells by signaling through VEGF receptors
Authors: Zhao Min , Bai Huai , Wang Entong , Forrester John V. , McCaig Colin D.
Published: December 2003

Controlling angiogenesis is crucial. Growth factors and cytokines are key regulators but a full understanding remains elusive. Endogenous electrical potential differences exist within and around the vasculature, both in relation to blood flow and in situations where active angiogenesis occurs, such as wound healing, development and tumor growth. Recent work shows that electrical stimulation induces significant angiogenesis in vivo, through enhanced vascular endothelial growth factor (VEGF) production by muscle cells. We report that applied electric fields (EFs) of small physiological magnitude directly stimulate VEGF production by endothelial cells in culture without the presence of any other cell type. EFs as low as 75-100 mV mm–1 (1.5-2.0 mV across an endothelial cell) directed the reorientation, elongation and migration of endothelial cells in culture. These pre-angiogenic responses required VEGF receptor activation and were mediated through PI3K-Akt and Rho-ROCK signaling pathways, resulting in reorganization of the actin cytoskeleton. This indicates that endogenous EFs might play a role in angiogenesis in vivo by stimulating the VEGF receptor signaling pathway, to induce key pre-angiogenic responses. In addition, it raises the feasibility of using applied EFs to initiate and guide angiogenesis through direct effects on endothelial cells.
Integrin-linked kinase regulates vascular morphogenesis induced by vascular endothelial growth factor
Authors: Kaneko Yayoi , Kitazato Kenji , Basaki Yuji
Published: December 2003

Integrin-linked kinase (ILK) is one of the signaling moieties that interact with the cytoplasmic domains of integrin β1 and β3 subunits. Integrin-mediated outside-in signals cooperate with vascular endothelial growth factor (VEGF) receptor to promote morphological changes, cell proliferation and motility in endothelial cells. In this report we demonstrate that VEGF-induced vessel morphogenesis of human umbilical vein endothelial cells (HUVEC) was inhibited by the transfection of a dominant negative, kinase-deficient ILK (ILK-KD), as well as by treatment with the phosphatidylinositol 3-kinase inhibitor LY294002. VEGF induced phosphorylation of protein kinase B (PKB/Akt), a regulator of cell survival and apoptosis, on serine 473, but not on threonine 308, in an ILK-dependent manner. Furthermore, transfection of antisense ILK (ILK-AS) blocked the survival effect of VEGF in annexin-V binding assays, and a VEGF-mediated decrease in caspase activity was reversed by both ILK-KD and ILK-AS as measured by a homogeneous caspase-3/7 assay. We also demonstrate that both chemotactic migration and cell proliferation of HUVEC induced by VEGF were suppressed by the inhibition of ILK. We conclude that ILK plays an important role in vascular morphogenesis mediated by VEGF.
Characterization of B-type cyclins in the smut fungusUstilago maydis: roles in morphogenesis and pathogenicity
Authors: García-Muse Tatiana , Steinberg Gero , Pérez-Martín José
Published: December 2003

Pathogenesis, morphogenesis and cell cycle are connected in the fungal pathogen Ustilago maydis. Here we report the characterization of the catalytic subunit of the cyclin-dependent kinase, encoded by the gene cdk1, and the two B-type cyclins present in this organism, encoded by the genes clb1 and clb2. These cyclins are not redundant and appears to be essential for cell cycle. The analysis of conditional mutants in cyclin genes indicates that Clb1 is required for G1 to S and G2 to M transitions, while Clb2 is specifically required for the onset of mitosis. Both Clb1 and Clb2 carry functional destruction boxes, and expression of derivatives lacking D-boxes arrested cell cycle at a post-replicative stage. High levels of Clb1 generated cells with anomalous DNA content that were hypersensitive to microtubule-destabilizing drugs. In contrast, high levels of Clb2 induce premature entry into mitosis, suggesting that Clb2 is a mitotic inducer in U. maydis. In addition, Clb2 affects morphogenesis, and overexpression of clb2 induces filamentous growth. Furthermore, we have found that appropriate levels of Clb2 cyclin are critical for a successful infection. Mutant strains with half a dose of clb2 or high level of clb2 expression are impaired at distinct stages in the infection process. These data reinforces the connections between cell cycle, morphogenesis and virulence in this smut fungus.
The role of annexin 2 in osteoblastic mineralization
Authors: Gillette Jennifer M. , Nielsen-Preiss Sheila M.
Published: December 2003

While the basic cellular contributions to bone differentiation and mineralization are widely accepted, the regulation of these processes at the intracellular level remains inadequately understood. Our laboratory recently identified annexin 2 as a protein involved in osteoblastic mineralization. Annexin 2 was overexpressed twofold in SaOSLM2 osteoblastic cells as a fusion protein with green fluorescent protein. The overexpression of annexin 2 led to an increase in alkaline phosphatase activity as well as an increase in mineralization. Our data suggest that the increase in alkaline phosphatase activity does not result from increased alkaline phosphatase transcript or protein levels; therefore we evaluated mechanism of action. We determined that both annexin 2 and alkaline phosphatase activity were localized to membrane microdomains called lipid rafts in osteoblastic cells. Annexin 2 overexpression resulted in an increase in alkaline phosphatase activity that was associated with lipid microdomains in a cholesterol-dependent manner. Furthermore, disruption of lipid rafts with a cholesterol sequestering agent or reduction of annexin 2 expression by specific antisense oligonucleotides each resulted in diminished mineralization. Therefore, intact lipid rafts containing annexin 2 appear to be important for alkaline phosphatase activity and may facilitate the osteoblastic mineralization process.
Factors Affecting Dental Attendance following Treatment for Dental Anxiety in Primary Dental Care
Authors: Dailey Yvonne-Marie , Crawford Alex N , Humphris Gerry , Lennon Michael A
Published: December 2003

Aim

To explore factors affecting patients’ dental attendance behaviour following referral from a dental anxiety clinic to a general dental practitioner.

Design

A four-year follow up of patients who completed a course of treatment for dental anxiety by conducting semi-structured interviews, face-to-face or by telephone, with confirmation of dental attendance from the dental records.

Subjects

Forty-one patients who had completed a course of treatment for dental anxiety, in a specially designed community clinic. Mean time since last dental visit before treatment was 7.8 years (range 0.5–29).

Results

Twenty-three patients were successfully followed up and 11 (47%) were receiving regular asymptomatic dental care. The dental anxiety scores of those who subsequently became asymptomatic attenders were significantly lower at follow-up than the patients who became symptomatic attenders (P=0.01). Effective dentist-patient communication was a common theme of the interviews.

Conclusions

At four-year follow-up, dental anxiety was substantially lower in those who subsequently became asymptomatic attenders than those who became symptomatic attenders. A positive dentist-patient relationship had developed with the asymptomatic attenders.
Occlusal Caries Diagnosis in Molar Teeth from Bitewing and Panoramic Radiographs
Authors: Thomas Michael F , Ricketts David NJ , Wilson Ronald F
Published: December 2003

Introduction

Previous studies have implied that the panoramic radiograph was inferior to the bitewing radiograph for caries diagnosis. However, these clinical studies lacked a method of validation. The aim of this study was to use an electronic caries meter (ECM II, LODE, Groningen, The Netherlands) to validate occlusal caries diagnosis made from bitewing and panoramic radiographs.

Materials and Method

Forty-nine Army recruits were examined with the ECM, and had bitewing and panoramic radiographs taken. In total 299 molar occlusal surfaces were available for examination. Seven examiners viewed the bitewing and panoramic radiographs on two separate occasions and assessed each occlusal surface for dentine caries as 1: almost definitely no caries, 2: probably no caries, 3: unsure, 4: caries probably present, and 5: caries almost definitely present. This was repeated on 20% of the radiographs at two further separate sittings. ECM conductance readings greater than 9 were taken to indicate dentine caries. Examiner decisions that caries was probably and definitely considered to be present were taken as positive diagnoses.

Results

Bitewing and panoramic radiographs provided sensitivity values of 0.25 and 0.19 and specificity values of 0.93 and 0.97 respectively. ROC analysis indicated no statistically significant difference in diagnostic quality between the bitewing and panoramic radiographs. Intra-examiner reproducibility was found to be poor to moderate (Kappa values for bite-wing = 0.31–0.44, panoramic = 0.07–0.54).

Conclusion

No difference in overall diagnostic performance was found between bitewing and panoramic radiographs for the diagnosis of occlusal dentine caries.
An Evaluation of Attitudes of Midlands Female Dentists to General Dental Practice: Will it Impact upon the Future Delivery of Primary Dental Care?
Authors: Thomas David J
Published: December 2003

Introduction

Both anecdotal evidence and research indicate that there is a developing manpower shortage in the delivery of dental care in the UK. With the predicted increase in registered female dentists, it is possible that future changes in work patterns might occur. If they are occurring, it is important to understand the needs of these female dentists in order to maximise efficient delivery of dental care. The aim of the study was to identify any gender differences that might exist in attitudes to the delivery of primary dental care within general dental practice in the Midlands.

Method

A Likert-style questionnaire was sent to all private and registered NHS GDPs who worked within the areas covered by three Midland health authorities.

Results

The results indicated that the clinical practice of female GDPs appears to involve less private work than their male counterparts and they seem less inclined than male GDPs to proactive development of private practise. Females were less likely than males to be principals and also less likely than males to employ other dentists. Female GDP attitudes towards management, net income and stress at work appears to differ to those of their male counterparts. There was little difference in gender attitude towards professional ethics and maintenance of clinical standards.
Ethnic Classification in Primary Dental Care and Dental Health Services Research: Time to Pause for Thought
Authors: Buck David J , Malik Shumalia , Murphy Natalie , Patel Vimal , Singh Seepaul , Syed Badrul , Vora Nikita
Published: December 2003

‘Ethnicity’ is an important concept in dental health services research and in enabling general dental practitioners to gain insight into their patients values and expectations. Since more health services research is being undertaken in primary dental care settings it is becoming an important issue for dental professionals and researchers in primary care to be aware of. Ethnicity is thought to be related to dental health inequalities and access and is often used as a stratifying variable in many dental studies. The meaning and use of the term however differs among researchers and among the public. It is clear that researchers and professionals need to pause for thought when considering what this often bandied about term actually means and the impact of different definitions. This is illustrated using examples from the authors’ own research and published papers in the medical and dental literature. There is also much debate about whether ethnicity—however defined—is an important predictor of differences in dental health in itself or is merely a marker for other factors such as social deprivation or the impact of ‘place’ on dental health. While the jury on this debate is out we suggest guidelines on the reporting of ethnicity should be outlined in the dental literature—perhaps updating those published in 1996 in the British Medical Journal.
Body Attitudes and Body Experiences in Suicidal Adolescents
Authors: Orbach Israel , Stein Daniel , Shani‐Sela Mirit , Har‐Even Dov
Published: December 2003

The relationships between cognitive and affective attitudes toward the body, body experiences (dissociation, insensitivity, and lack of control), and suicidal tendencies were examined as a derivative of the hypothesis that bodily attitudes and experiences may facilitate suicidal acting out. Three groups of adolescents (aged 14–18), including suicidal (made a suicide attempt) and nonsuicidal inpatients and controls, were compared with regard to suicidal tendencies, various body aspects, and depression and anxiety. A series of MANOVAs, discriminant analysis, Pearson correlations, and regressions were employed. The results show that the suicidal group differed from the two nonsuicidal groups in feelings toward the body, body protection, and body dissociation. Some aspects of bodily measures discriminated between suicidal and nonsuicidal subjects. In addition, various bodily measures were associated with and statistically predicted suicidal tendencies. The discussion focuses on the web of associations between body attitudes and experiences and their role in suicidal behavior.
Suicidality Patterns and Sexual Orientation‐Related Factors Among Lesbian, Gay, and Bisexual Youths
Authors: D'Augelli Anthony R. , Hershberger Scott L. , Pilkington Neil W.
Published: December 2003

Three hundred fifty lesbian, gay, and bisexual youths aged 14 to 21 years were questioned about suicidal thoughts and behaviors, families' reactions to youths' sexual orientation, and suicidality among relatives and friends. Results confirmed an association between sexual orientation and suicidality. Nearly half (42%) had sometimes or often thought of suicide; one third (33%) reported at least one suicide attempt. Many related suicidal ideation and suicide attempts to their sexual orientation. Most attempts followed awareness of same‐sex feelings and preceded disclosure of sexual orientation to others. One quarter said a family member had made a suicide attempt, and nearly three quarters said a close friend had attempted suicide.
An Investigation of Psychopathology in Nonreferred Suicidal and Nonsuicidal Adolescents
Authors: Mazza James J. , Reynolds William M.
Published: December 2003

This investigation examined self‐reported psychopathology in a school‐based sample of 456 suicidal and nonsuicidal adolescents. The sample consisted of four groups: three at‐risk for suicidal behavior based on current suicidal ideation as assessed by the Suicidal Ideation Questionnaire (SIQ; Reynolds, 1988), past suicide attempts, or both; and one nonsuicidal comparison group. Psychopathology was examined using ten scales from the Adolescent Psychopathology Scale (APS; Reynolds, 1998a) including: Major Depression, Conduct Disorder, Substance Abuse, Schizophrenia, Adjustment Disorder, Anorexia Nervosa, Borderline Personality Disorder, Obsessive‐Compulsive Personality Disorder, Schizotypal Personality Disorder, and Avoidant Personality Disorder. Analyses were conducted separately for males and females using a MANOVA design that examined psychopathology severity among the four groups. Adolescents who engaged in past or current suicidal behavior had higher psychopathology severity scores compared to their nonsuicidal peers. Males with current suicidal thoughts who had attempted suicide had the highest levels of psychopathology severity compared to males in the other three groups. Females with a past suicide attempt or current suicidal ideation had higher psychopathology severity scores compared to nonsuicidal females. Results show greater psychopathology in school‐based adolescents who have engaged in past and/or current suicidal behavior. The need for clinicians and mental health professionals working with at‐risk youth to focus on concurrent psychopathology along with suicidal behavior is discussed.
Suicide and Firearm Prevalence: Are Youth Disproportionately Affected?
Authors: Birckmayer Johanna , Hemenway David
Published: December 2003

The effect of firearm availability on suicide may differ among age groups. We used regression analysis to examine the relationship between suicide rates and household firearm ownership for four age groups in the nine census regions from 1979 to 1994, adjusting for regional divorce rates, education, unemployment, and urbanicity. Results showed that firearm ownership levels are correlated with suicide rates among 15‐ to 24‐year‐olds and 65‐ to 84‐year‐olds, but not among 25‐to 64‐year‐olds. The findings suggest that if the relationship is causal, a 10% fall in regional firearm ownership levels would lead to a 3.0% decrease in suicide rates.
Attitudes Toward the Unification of Western Europe and Cross‐National Suicide Rates: Eight European Countries, 1973–1990
Authors: Fernquist Robert M.
Published: December 2003

Durkheim's (1897/1951) theory of political integration argues that when political crises occur, individuals band together to solve the problem at hand. As a result, this increased integration yields lower suicide rates. The purpose of this analysis is to examine a different component of the concept of political integration—that of attitudes. During the past couple of decades, individuals in eight Western European countries have been asked about their attitudes toward the unification of Western Europe. Cross‐sectional time series analysis reveals that the attitudes individuals hold toward such an event are significantly related to suicide rates. Although Durkheim's theory of political integration focuses on events within a given country, the research herein finds that political integration exists on an international level as well. A reformulation of Durkheim's theory of political integration is put forth.
U.S. Involuntary Mental Health Commitment Statutes: Requirements for Persons Perceived to be a Potential Harm to Self
Authors: Werth James L.
Published: December 2003

The civil commitment statutes of all 50 states and the District of Columbia were reviewed to determine: (1) What is required for a person who is believed to be at serious and imminent risk of self‐harm to be eligible for involuntary hospitalization; and (2) Whether an attempt to involuntarily hospitalize was required or was merely an option when the requirements found in number 1 were met. The analysis revealed that nearly 85% of the jurisdictions require dangerousness to self to be the result of a mental illness, and only two jurisdictions mandate attempts at involuntary commitment if a person is deemed to be an imminent harm to self. These results have implications for practice with individuals who are suicidal.
Early Suicide Following Discharge from a Psychiatric Hospital
Authors: McKenzie Immanuel , Wurr Catherine
Published: December 2003

Social and clinical risk factors for completed suicide occurring shortly after discharge from a psychiatric hospital were examined in this case‐control study. Seventy‐seven individuals who received “suicide” or “undetermined death” verdicts at inquest, and who had been previously discharged from psychiatric hospitals in Bradford, U.K., were compared with a control group. A history of deliberate self‐harm was significantly associated with early suicides compared with both late suicides and controls. A diagnosis of mood disorder, specifically depression, and longer case‐notes were also significantly associated with early suicides compared to controls. This study has implications for risk management of recently discharged psychiatric patients.
Factors Associated with the Medical Severity of Suicide Attempts in Youths and Young Adults
Authors: Swahn Monica H. , Potter Lloyd B.
Published: December 2003

This study examined factors associated with the medical severity of suicide attempts focusing on demographic characteristics, mental health characteristics, and the circumstances of the suicide attempt. Analyses were based on 153 nearly lethal suicide attempters and 47 less lethal suicide attempters aged 13–34 years who presented to emergency departments in Houston, Texas. The results show that young age was significantly associated with a nearly lethal suicide attempt. Prior suicide attempts, hopelessness, depression, and help‐seeking (ever) were significantly and negatively associated with a nearly lethal suicide attempt. None of the suicide attempt factors occurring prior to the attempt were associated with a nearly lethal suicide attempt.
Alcohol Consumption and Nearly Lethal Suicide Attempts
Authors: Powell Kenneth E. , Kresnow Marcie‐jo , Mercy James A. , Potter Lloyd B. , Swann Alan C. , Frankowski Ralph F. , Lee Roberta K. , Bayer Timothy L.
Published: December 2003

We conducted a case‐control study of the association between nearly lethal suicide attempts and facets of alcohol consumption; namely, drinking frequency, drinking quantity, binge drinking, alcoholism, drinking within 3 hours of suicide attempt, and age began drinking. Subjects were 13–34 years of age. In bivariable analyses, all measures were associated with nearly lethal suicide attempts. Odds ratios ranged from 2.4 for alcoholism to 7.0 for drinking within 3 hours of attempt. All exposure variables except age began drinking exhibited a J‐shaped relationship between alcohol exposure and nearly lethal suicide attempt. After controlling for potential confounders and other measures of alcohol exposure, drinking within 3 hours of attempt remained most strongly (odds ratios > 6) associated. Alcoholism remained significantly associated in most models, but at lower strength.
Characteristics of Impulsive Suicide Attempts and Attempters
Authors: Simon Thomas R. , Swann Alan C. , Powell Kenneth E. , Potter Lloyd B. , Kresnow Marcie‐jo , O'Carroll Patrick W.
Published: December 2003

Suicide attempts often are impulsive, yet little is known about the characteristics of impulsive suicide. We examined impulsive suicide attempts within a population‐based, case‐control study of nearly lethal suicide attempts among people 13–34 years of age. Attempts were considered impulsive if the respondent reported spending less than 5 minutes between the decision to attempt suicide and the actual attempt. Among the 153 case‐subjects, 24% attempted impulsively. Impulsive attempts were more likely among those who had been in a physical fight and less likely among those who were depressed. Relative to control subjects, male sex, fighting, and hopelessness distinguished impulsive cases but depression did not. Our findings suggest that inadequate control of aggressive impulses might be a greater indicator of risk for impulsive suicide attempts than depression.
Medical Conditions and Nearly Lethal Suicide Attempts
Authors: Ikeda Robin M. , Kresnow Marcie‐jo , Mercy James A. , Powell Kenneth E. , Simon Thomas R. , Potter Lloyd B. , Durant Tonji M. , Swahn Monica H.
Published: December 2003

Physical illness has been studied as a risk factor for suicidal behavior, but little is known about this relationship among younger persons. We conducted a population‐based, case‐control study in Houston, Texas, from November 1992 through September 1995. The final sample consisted of 153 case‐ and 513 control‐subjects aged 13 to 34 years. Case patients were identified at hospital emergency departments and met criteria for a nearly lethal suicide attempt. Control subjects were recruited via a random‐digit‐dial telephone survey. Case patients were more likely than controls to report having any serious medical conditions (crude OR = 3.23; 95% CI = 2.12–4.91). After controlling for age, race/ethnicity, alcoholism, depression, and hopelessness, the adjusted odds ratio for men was 4.76 (95% CI = 1.87–12.17), whereas the adjusted odds ratio for women was 1.60 (95% CI‐0.62–4.17), suggesting that young men with medical conditions are at increased risk for nearly lethal suicide attempts. Increased efforts to identify and appropriately refer these patients are needed.
Metabolic and neuropsychological phenotype in women heterozygous for ornithine transcarbamylase deficiency
Authors: Gyato Kunsang , Wray J. , Huang Z. J. , Yudkoff M. , Batshaw Mark L.
Published: December 2003

We compared neurocognitive indices with clinical status, mutation analysis, and urea synthetic capacity in 19 women heterozygous for ornithine transcarbamylase deficiency. Although as a group, these women had average IQ scores, they displayed a specific neuropsychological phenotype with significant strengths in verbal intelligence, verbal learning, verbal memory, and reading, and significant weaknesses in fine motor dexterity/speed and nonsignificant weaknesses in nonverbal intelligence, visual memory, attention/executive skills, and math. This suggests selective vulnerability of white matter and better preservation of gray matter. When the group was divided into symptomatic and asymptomatic subgroups, based on either clinical history or residual urea synthetic capacity, the asymptomatic subgroup outperformed the symptomatic subgroup on all tested domains of neuropsychological functioning. Furthermore, the amount of residual urea synthetic capacity was predictive of several end point cognitive measures. There was no correlation between neonatal versus late‐onset mutation or between normal or abnormal allopurinol challenge and neuropsychological outcome. In sum, we identified a specific metabolic and neurocognitive phenotype in women heterozygous for ornithine transcarbamylase deficiency. The findings support the importance of maintaining meticulous metabolic control in children with urea cycle disorders, because even mildly symptomatic subjects demonstrate cognitive deficits.
Conversion of Natural Substances by Microbial Enzymes
Authors: Tamm Ch.
Published: December 2003

Micro‐organisms form enzymes that catalyze many reactions which are difficult to carry out in the laboratory or which involve many steps. Enzymes even react with substances which are normally foreign to them. The frequently high stereospecificity of microbiological reactions is of particular significance. The most important types of reactions are: hydroxylations, dehydrogenations (oxidations), and hydrogenations (reductions), cleavage of ester and C‐C bonds, and transglycosidations. The variety of the compounds converted is extremely great.
Elastomeric Fibers Based on Polyurethanes
Authors: Rinke H.
Published: December 2003

Highly elastic polyurethanes suitable for fiber production can be obtained by various synthetic routes based on diisocyanate polyaddition processes. Macrodiisocyanates obtained from long chain diols and diisocyanates are allowed to react with polyamines during fiber formation (chemical spinning process) or the macrodiisocyanates are treated in solvents (e.g. dimethylformamide) with polyamines to give highly viscous, spinnable solutions of polymer. Both methods yield highly elastic polymers with wide‐mesh network structures. The production of polyurethane fibers and their structures and physical properties are described.
Theories of Ion‐Exchange Column Performance: A Critical Study
Authors: Helfferich F.
Published: December 2003

Many theories of ion‐exchange column performance, differing widely in their simplifying assumptions and their results, have been advanced. For successful application it is vital to choose, in each particular case, the most appropriate theory. this requires a thorough general understanding of the phenomena and a precise knowledge of the consequences of the simplifying assumptions. The most important qualitative characteristics of ion‐exchange columns are outlined, especially the formtion of self‐sharpening and non‐sharpening boundaries and of constant and proportionate patterns. The commonly used quantitative theories and calculation methods are then discussed and their adequacy, their shortcomings, and the ranges of their applicability are critically studied.
Biology and Biochemistry of Reproduction and Contraception
Authors: Jöchle W.
Published: December 2003

Maturation of sperm and ovum are not autonomous processes. Rather, germ cell activity is controlled by a regulatory center in the hypothalamus. This assures germ cell maturation, fertilization, and development of the fetus until birth. Command, functional release, and feedback take place by humoral paths which involve gonadotropin releasers, gonadotropins, and sex harmones. Even in antiquity, attempts at birth control involved a search for substances which might inhibit the essential physiological and biochemical reproductive processes. This report deals with more recent efforts along these lines.
The Structure of Ice
Authors: Brill R.
Published: December 2003

Of the seven modifications of ice that are stable at temperatures above −80°C, modification I has so far been investigated in especially great detail. An eighth modification (ice Ic)which is stable only below −80°C is alsowell known. In the following, the crystal lattice structure of these modifications and the formations of mixed crystals are discussed.
Syntheses Using Pyridinium Salts (IV)
Authors: Kröhnke F.
Published: December 2003

Cleavage of N‐phenylpyridinium or N‐vinylpyridinium salts with secondary aliphatic amines leads to aromatic amino compounds or enamines which are often unobtainable by other routes. The other fragment, glutacondialdehyde or its monoanil, gives azulenes, as shown by Ziegler and Hafner, as well as König; these compounds can also be prepared from alkylpyridinium salts with cyclopentadienylsodium (Hafner). Syntheses of labile aldehydes which are otherwise difficult to obtain and of α‐ketocarboxylic acids, starting from pyridinium salts and proceeding via nitrones or α‐cyanoanils, are illustrated by many new examples. Benzimidazoles, benzothiazoles, and amidines are accessible from pyridinium salts via nitrones or α‐cyanoanils; cyanoanils can be transformed into quinoxalines (including xanthopterine), perimidines, etc. Furthermore, nitrosonaphthols and nitrosonaphthylamines react with pyridinium salts containing an active methylene group on the nitrogen, leading to new ring systems. Further synthetic possibilities arise from nucleophilic displacements of the pyridine in pyridinium salts by SN 2 reactions. Combination of the route via nitrones with the methods of Arndt‐Eistert, Ortoleva‐King, or with chloromethylation constitutes a significant enlargement of its range of application. The formation of α‐cyanoanils from diazoketones permits synthesis of α‐keto‐β‐amino acids from α‐amino acids, or of phenylglyoxylic acids from benzoic acids by chain extension.
Syntheses of s‐Triazine and Substituted s‐Triazines
Authors: Bredereck H. , Effenberger F. , Hofmann A. , Hajek M.
Published: December 2003

In the last account of our investigations in the amide field [1], we reported inter alia on the preparation and reactions of trisformamidomethane. Further work with this compound led to simple syntheses particularly of heterocyclic compaunds. Following the pattern of these syntheses, compounds other than trisformamidomethane were employed for formylation and ring‐closure; these included formates, orthoformates, formamidine, dimethylformamide diethylacetal, and formamide. Part of this recent research is reported below.
Neighboring Group and Substituent Effects in Organosulfur Compounds
Authors: Gundermann K. D.
Published: December 2003

Thioether groups participate in nucleophilic substitution reactions at adjacent carbon atoms, in the addition of alkane and arenesulfenyl halides onto olefinic double bonds, and in elimination reactions which lead to olefins and which proceed via intermediate episulfonium ions. Studies of alkylthioacrylic acid derivatives, which are readily synthetized because of the neighboring group effect, show that the presence of thioether groups in the α‐position of acrylic acid systems leads to particularly high reactivity in “head‐to‐head” dimerizations.
The Course of the Willgerodt‐Kindler Reaction of Alkyl Aryl Ketones
Authors: Asinger F. , Schäfer Wolfgang , Halcour K. , Saus A. , Triem H.
Published: December 2003

Ketones react with sulfur and NH3 or amines at room temperature to produce Δ3‐thiazolines, 5‐alkylidene‐Δ3‐thiazolines, Δ3‐imidazoline‐5‐thiones, hexathiacycloheptane derivatives, α,α′‐dioxodisulfides, bis‐(1‐aralk‐1‐yl) disulfides, or thiocarboxamides, depending on the coreactant and on the reaction conditions. It was recognized that the formation of all of these numerous types of compounds can be explained basically by primary thiolations and geminal dithiolations, which in conjunction with their reverse reaction (desulfurization) and the assumption of a thioreductone equilibrium permit a new interpretation of the course of the Willgerodt‐Kindler reaction of alkyl aryl ketones.
Complex Formation with Organoaluminum Compounds
Authors: Lehmkuhl H.
Published: December 2003

From theoretical considerations of the Lewis‐acid character of the organoaluminum compounds AlR3 and AlEt2X and of possible combinations of these acids with Lewis bases‐chiefly anions combined with alkali metal ions – by reactions analogous to neutralizations, as well as on the basis of experimental findings, the compounds AlEt2X and the alkali salts MY can be arranged in the order of their tendency to form complexes, in dependence on the nature of X and Y, respectively. – Numerous displacement reactions, in which a stronger complexing group replaces a weaker one, confirm these series. These reactions have led to the formation of new complex compounds of alkylaluminum with the hitherto unknown alkyls of calcium, strontium, and barium, and also to the preparation of [NEt4][AlEt4] and [SbEt4][AlEt4]. Displacement of ethylsodium from NaAIEt4 with the aid of NaOR – which is readily complexed – in the presence of benzene provides a simple mode of conversion of alkylaluminum into phenylaluminum compounds:

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Recent Developments in the Chemistry of Pteridines
Authors: Pfleiderer W.
Published: December 2003

The abundant experimental material available on the chenistry of the pteridines, as well as the reports given at the Third International Symposium on Pteridines have been reviewed and the most important results of the past ten years incorporated into the present article. Syntheses, reactions, and structural problems are reviewed and natural pteridines and their possible biochemical significance are discussed.
Tetramethylurea as a Solvent and Reagent
Authors: Lüttringhaus A. , Dirksen H. W.
Published: December 2003

Tetramethylurea is an excellent solvent for organic substances, particularly aromatic compounds. It is suitable as reactions. Being inert toward Grignard compounds, it is a useful solvent for reactions of the latter with compounds that are sparingly soluble in ether. Several industrially feasible syntheses of tetramethylurea are discussed.
Reactionss of Sodium Hydrazide with Organic Compounds
Authors: Kauffmann Th. , Hacker H. , Hage S. M. , Hansen J. , Henkler H. , Kosel Ch. , Lötzsch K. , Müller Horst , Rauch E. , Schoeneck W. , Schulz J. , Sobel J. , Spaude S. , Weber R. , Wolf D. , Zengel H.
Published: December 2003

The reactions of sodium hydrazide with organic compounds are reviewed for the first time. The great variety of these reactions is mainly due to the extraordinary ease with which the hydrazide ion adds onto unsaturated compounds, usually to form unstable adducts that achieve stability in various ways.
Recent Advances in the Synthesis of 19‐Norsteroids
Authors: Windholz Thomas B. , Windholz Martha
Published: December 2003

This review describes approaches for improved preparations of 19‐norsteroids. They are based on novel total syntheses of estrone and on intramolecular functionalization and elimination of the C‐19 methyl group in androstane derivatives.
Biosynthesis, Structure, and Biological Action of the Lipids of the Tubercle Bacillus
Authors: Lederer E.
Published: December 2003

The extensive studies of R.J. Anderson between 1926 and 1946 nad the subsequent work of Stenhagen, Polgar, and Cason, and of the author's laboratory have demonstrated the astonishing abilities of the tubercle bacillus in synthetizing lipids. Numerous branched‐chain fatty acids, glycolipids, peptidolipids, and peptidoglycolipds have been isolated, and their structures more or less elucidated. Such work is of interest not only to natural‐priduct chemists, and biochemists, but especially to biologists and pathologists who are concerned with the harmful effects caused by the tubercle bacillus. The present article discusses chiefly three points: 1. The biogenesis of the branched‐chain fatty acids. ‐ 2. The structures of several glyco‐, peptido‐, and peptidoglycolipids. ‐ 3. Adjuvant activity and immunization by the lipids of the tubercle bacillus.