Direct binding of hepatocyte growth factor and vascular endothelial growth factor to CD44v6.

CD44v6, a member of the CD44 family of transmembrane glycoproteins is a co-receptor for two receptor tyrosine kinases (RTKs), Met and VEGFR-2 (vascular endothelial growth factor receptor 2). CD44v6 is not only required for the activation of these RTKs but also for signalling. In order to understand the role of CD44v6 in Met and VEGFR-2 activation and signalling we tested whether CD44v6 binds to their ligands, HGF (hepatocyte growth factor) and VEGF (vascular endothelial growth factor), respectively. FACS analysis and cellular ELISA showed binding of HGF and VEGF only to cells expressing CD44v6. Direct binding of CD44v6 to HGF and VEGF was demonstrated in pull-down assays and the binding affinities were determined using MicroScale Thermophoresis, fluorescence correlation spectroscopy and fluorescence anisotropy. The binding affinity of CD44v6 to HGF is in the micromolar range in contrast with the high-affinity binding measured in the case of VEGF and CD44v6, which is in the nanomolar range. These data reveal a heparan sulfate-independent direct binding of CD44v6 to the ligands of Met and VEGFR-2 and suggest different roles of CD44v6 for these RTKs.

Application of LC-TOF MS to analysis of hemoglobin acetaldehyde adducts in alcohol detoxification patients.

Acetaldehyde adducts of hemoglobin have been regarded as potential biochemical markers of alcohol exposure. In this study a novel sensitive method using liquid chromatography coupled to time-of-flight mass spectrometry (LC-TOF MS) has been used to investigate changes in adduct levels in alcohol detoxification patients. Hemoglobin and authentic blood samples from 66 adults with an alcohol-dependence syndrome and from 12 children were analyzed for acetaldehyde modifications with and without trypsin digestion using LC-TOF MS. After in-vitro incubation of hemoglobin with increasing concentrations of acetaldehyde, followed by tryptic digestion, 21 modified peptide fragments could be identified from their accurate mass and retention time shift. Eight of these could also be detected in authentic human blood samples. Trace amounts in children's blood were indicative of an endogenous source. Modified peptide levels in patients' samples with and without ethanol were significantly different, as also were levels in samples from admission and from five days later. Samples obtained 5, 10, or 15 days after admission did not differ in adduct levels. The LC-TOF MS method was sensitive enough to detect acetaldehyde-modified hemoglobin peptides in blood samples from patients with an alcohol-dependence syndrome. However, elevated levels were only observed after recent ethanol consumption and decreased during five days of abstinence, suggesting that acetaldehyde-modified tryptic peptides of hemoglobin are potential biomarkers only for short-term ethanol ingestion.

Combination of water-jet dissection and needle-knife as a hybrid knife simplifies endoscopic submucosal dissection.

BACKGROUND: The safety and efficacy of endoscopic submucosal dissection (ESD) is very dependent on an effective injection beneath the submucosal lamina and on a controlled cutting technique. After our study group demonstrated the efficacy of the HydroJet in needleless submucosal injections under various physical conditions to create a submucosal fluid cushion (Selective tissue elevation by pressure = STEP technique), the next step was to develop a new instrument to combine the capabilities of an IT-Knife with a high-pressure water-jet in a single instrument. In this experimental study, we compared this new instrument with a standard ESD technique. METHODS: Twelve gastric ESD were performed in six pigs under endotracheal anesthesia. Square areas measuring 4-cm x 4-cm were marked out on the anterior and posterior wall in the corpus-antrum transition region. The HybridKnife was used as an standard needle knife with insulated tip (i.e., the submucosal injection was performed with an injection needle and only the radiofrequency (RF) part of the HybridKnife was used for cutting (conventional technique)) or the HybridKnife was used in all the individual stages of the ESD, making use of the HybridKnife's combined functions (HybridKnife technique). The size of the resected specimens, the operating time, the frequency with which instruments were changed, the number of bleeding episodes, and the number of injuries to the gastric wall together with the subjective overall assessment of the intervention by the operating physician were recorded. RESULTS: The resected specimens were the same size, with average sizes of 16.96 cm(2) and 15.85 cm(2) resp (p = 0.8125). Bleeding episodes have been less frequent in the HybridKnife group (2.83 vs. 3.5; p = 0.5625). The standard knife caused more injuries to the lamina muscularis propria (0.17 vs. 1.33; p = 0.0313). The operating times had a tendency to be shorter with the HybridKnife technique (47.18 vs. 58.32 minute; p = 0.0313). DISCUSSION: The combination of a needle-knife with high-pressure water-jet dissection improved the results of endoscopic submucosal dissection in this experimental setting. Because the frequency of complications is still high, further improvements to the instrument are necessary.

Cryoplasty for the prevention of arterial restenosis.

Restenosis after percutaneous transluminal angioplasty remains the limiting factor for the long-term benefit of endovascular therapies of peripheral arterial occlusive disease. Despite a variety of modifications and adjuncts to angioplasty such as bare metal stents, covered stents, and drug-eluting stents as well as a number of new technologies like laser angioplasty and cutting balloon angioplasty, restenosis rates have not been significantly affected and remain inferior to those for surgery for long lesions in the femoropopliteal segment. Cryoplasty, which combines balloon angioplasty with the application of cryothermal energy to the vessel wall, was suggested as a promising approach to prevent the formation of neointimal hyperplasia after angioplasty procedures. This review discusses the basic principles of cryoplasty, summarizes the current data on restenosis rates after cryoplasty treatment, and evaluates cryoplasty as a new treatment method to solve the problems associated with restenosis development. The results of the clinical studies suggest that cryoplasty is a feasible and safe technique in the treatment of femoropopliteal disease, however, they have failed to prove any superiority of cryoplasty over conventional angioplasty.

Lack of bufadienolides in the skin secretion of red bellied toads, Melanophryniscus spp. (Anura, Bufonidae), from Uruguay.

The South-American red bellied toads (Melanophryniscus spp.) belonging to the Bufonidae family contain toxic alkaloids in their skin, predominantly of the pumiliotoxin group. Whole animal methanolic extracts of individual specimens of three species (Melanophryniscus atroluteus, M. devincenzii, and M. montevidensis) were analyzed for the presence of toad specific bufadienolides and indolalkylamines (serotonin derivatives) by HPLC-electrospray (ESI)-MS-TOF. No bufadienolides, but few bufotenines, mainly dehydrobufotenine, were detected in the extracts in variable amounts. The concentration of the dehydrobufotenine in the extracts seems to be species specific. Whereas M. atroluteus and M. montevidensis contain very low or trace amounts, M. devincenzii specimens exhibit high concentrations of this indolalkylamine. In comparison, analysis of extracts from Bufo arenarum (Uruguay) and from B. bufo (Germany) confirmed the presence of bufadienolides as well as of bufotenine derivatives. Tadpoles of both species exhibited a different pattern: extracts from B. arenarum tadpoles contained only dehydrobufotenine, but those from B. bufo tadpoles bufotoxin and two alkylamines. Melanophryniscus toads appear not to be able to compensate the high variability of toxic skin alkaloids by producing defensive bufadienolides.

Psychiatric co-morbidity in caregivers and children involved in maltreatment: a pilot research study with policy implications.

OBJECTIVE: The purpose of this study was to determine the lifetime incidence of mental disorders in caregivers involved in maltreatment and in their maltreated child. METHODS: Lifetime DSM-III-R and IV psychiatric diagnoses were obtained for 53 maltreating families, including at least one primary caregiver and one proband maltreated child or adolescent subject (28 males, 25 females), and for a comparison group of 46 sociodemographically, similar nonmaltreating families, including one proband healthy child and adolescent subject (22 males, 22 females). RESULTS: Mothers of maltreated children exhibited a significantly greater lifetime incidence of anxiety disorders (especially post-traumatic stress disorder), mood disorders, alcohol and/or substance abuse or dependence disorder, suicide attempts, and comorbidity of two or more psychiatric disorders, compared to control mothers. Natural fathers or mothers' live-in mates involved in maltreatment exhibited a significantly greater lifetime incidence of an alcohol and/or substance abuse or dependence disorder compared to controls. The majority of maltreated children and adolescents reported anxiety disorders, especially post-traumatic stress disorder (from witnessing domestic violence and/or sexual abuse), mood disorders, suicidal ideation and attempts, and disruptive disorders. Most maltreated children (72%) suffered from comorbidity involving both emotional and behavioral regulation disorders. CONCLUSIONS: Families involved in maltreatment manifest significant histories of psychiatric comorbidity. Policies which target identification and treatment of comorbidity may contribute to breaking the intergenerational transmission of maltreatment.

A pilot longitudinal study of hippocampal volumes in pediatric maltreatment-related posttraumatic stress disorder.

BACKGROUND: Adult posttraumatic stress disorder (PTSD) is associated with decreased hippocampal volumes; however, decreased hippocampal volumes were not seen in pediatric maltreatment-related PTSD. We examined hippocampal volumes longitudinally to determine if a history of childhood traumatic stress alters hippocampal growth during puberty. METHODS: Magnetic resonance imaging was used to measure temporal lobes, amygdala, and hippocampal volumes in nine prepubertal maltreated subjects with pediatric maltreatment-related PTSD and nine sociodemographically matched healthy nonmaltreated yoked control subjects at baseline and after at least 2 years follow-up (during the later stages of pubertal development) using identical equipment and measurement methodology. RESULTS: Temporal lobe, amygdala and hippocampal volumes did not differ between groups at baseline, follow-up, or across time. CONCLUSIONS: Whereas these data are from a small sample, the results do not support hippocampal changes in pediatric maltreatment-related PTSD.

Expression of nitric oxide synthase in the developing rat hippocampus.

Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry was used to study the development of neurons synthesizing nitric oxide (NO) in the postnatal rat hippocampus. We show that NADPH-d reactive somata and processes are present from the day of birth until adulthood in the Ammon's horn. The dentate gyrus, however, has a more delayed period of nitric oxide synthase (NOS) expression with the staining appearing only by the end of the first postnatal week. Our results suggest that the time course of NOS expression correlates with the developmental sequence of events described in the hippocampus and that NO could be involved in the development of connections in this structure.

Epidemiology of homicide in Allegheny County, Pennsylvania, between 1966-1974 and 1984-1993.

BACKGROUND: We compared homicide death rates and characteristics of homicide victims and perpetrators in 1966-1974, 1984-1990, 1992-1993, and 1996 in Allegheny County, Pennsylvania, in an attempt to detect possible differences in the pattern of homicides. METHODS: Data were obtained from death certificates, coroner's records, police reports and newspapers. RESULTS: In the 1990s the homicide death rate increased for 15- to 24-year-old black men. The rate was 69 per 100,000/year for black men ages 15-24 years from 1966 to 1974 and rose to 275 per 100,000 from 1992 to 1993. Currently, the rates appear to be declining again. Preliminary data from 1996 showed the number of homicide deaths excluding vehicular homicides between 1993 and 1996 to decline from 19 to 8 for white men, from 70 to 42 for black men, from 9 to 3 for white women, and from 13 to 6 for black women with little change in the population (denominator). The dramatic drop from 111 to 61 deaths over a short time is similar to changes across the United State and is characteristic of epidemic rise and fall of homicides in the community. CONCLUSIONS: Between 1966 and 1993 Allegheny County experienced two separate homicide epidemics, one between 1966 and 1976 and the other between 1990 and 1993. Epidemics of homicide occur frequently and have different characteristics. New characteristics of the most recent epidemic of homicide include more homicides out of home, among strangers; less association with alcohol; and multiple perpetrators. Drug-use-associated homicides have also increased. Guns are the primary agents of homicide epidemics.

SUBCLAVIAN STEAL SYNDROME: A Review.

The Subclavian Steal Syndrome is a condition that results from the stenosis or occlusion of the subclavian artery proximal to the origin of the vertebral artery. The blockage causes the reversal of the normal direction of blood flow in the vertebral artery which is termed the "steal", because it steals blood from the cerebral circulation. Blood is drawn from the contralateral vertebral, basilar or carotid artery regions into the low-pressure ipsilateral upper limb vessels. Although a relatively uncommon disease, it represents a condition which mimics many conditions often treated by chiropractors and osteopaths. The term subclavian steal syndrome is applied when reversed vertebral artery flow causes cerebral ischaemia with associated symptoms of vertebrobasilar hypoperfusion and/or symptoms of brainstem or arm ischaemia. This syndrome exists as an important consideration in the differential diagnosis of cerebral and brachial ischaemia.

Patterns of nitric oxide synthase expression in the developing superior colliculus.

Nitric oxide (NO) is synthesized in cells of both the central and peripheral nervous system and has been implicated in several forms of synaptic plasticity. The enzyme that produces NO, nitric oxide synthase (NOS), can be visualized in the brain by the reduced nicotinamide adenine dinucleotide phosphate diaphorase histochemistry technique (NADPH-d). We have used NADPH-d activity to detect the presence of NOS-positive cells in the developing rat superior colliculus. Our results showed that NOS is present in cells and neuropil in the developing and adult rat superior colliculus. The first NOS-positive cells appeared at postnatal day 7 and were weakly stained. The number and intensity of the NOS-positive cells increased progressively during the following days reaching a maximum at postnatal day 15. By the end of the third postnatal week, both the number and intensity of stained cells showed an adult-like pattern. The NOS-positive cells showed a Golgi-like morphology and we have found that all cell types present in the superior colliculus express the enzyme. The expression of NOS by tectal cells parallels the functional development of the retino-collicular and cortico-tectal projections and suggest that nitric oxide synthase-positive cells might be involved in this process. In this review we highlighted some of the recent descriptions of the expression of NOS in the mammalian visual system with emphasis in the superior colliculus and correlate these findings with several developmental events taking place in this structure.

Long-term impact of exposure to suicide: a three-year controlled follow-up.

OBJECTIVE: To determine the long-term impact of exposure to suicide on the friends of adolescent suicide victims. METHOD: One hundred sixty-six friends of suicide victims and unexposed community controls were followed up at periodic intervals up to 3 years after the suicide, using the Schedule for Affective Disorders and Schizophrenia for School-Age Children, Epidemiologic and Present Episode versions, to assess current and incident psychopathology. RESULTS: The incidence of suicide attempts was comparable between groups over the entire follow-up period, despite higher rates of baseline and incident psychopathology in the exposed group. An increased incidence of depression and anxiety was found in friends that was most marked in the first 6 months of follow-up. An increased incidence of posttraumatic stress disorder (PTSD) in those exposed was seen in the early as well as the later periods of follow-up. Those exposed youths who knew the suicide plans of the suicide victim were at the greatest risk for incident depression and PTSD over the entire course of follow-up. CONCLUSION: Exposure to suicide does not result in an increased risk of suicidal behavior among friends and acquaintances, but it has a relatively long impact in terms of increased incidence of depression, anxiety, and PTSD.

The impact of adolescent suicide on siblings and parents: a longitudinal follow-up.

The psychiatric sequelae of loss of a family member to suicide were evaluated in parents and siblings of adolescent suicide victims and controls, who were followed up to 3 years after the suicide. Siblings did not show an increased risk for the development of depression, posttraumatic stress disorder (PTSD), or other conditions over the course of follow-up, despite showing a prolonged elevated level of grief symptomatology. Mothers showed an increased rate of recurrence of depression over follow-up, whereas fathers did not show an increased incidence of disorder compared to fathers of controls. The interrelationship of bereavement and depression for siblings, parents, and others exposed to suicide is discussed.

Posttraumatic stress disorder in peers of adolescent suicide victims: predisposing factors and phenomenology.

OBJECTIVE: To examine the factors predisposing to posttraumatic stress disorder (PTSD) in peers of adolescent suicide victims. METHOD: One hundred forty-six adolescents who were the friends of 26 suicide victims were studied. Five percent (n = 8) developed PTSD after exposure to suicide. These 8 subjects with PTSD were compared to the remainder of the exposed subjects (n = 138). RESULTS: Subjects with PTSD were more likely than those without PTSD to have had a history of substance abuse, agoraphobia, and suicide attempts. Subjects who developed PTSD were more likely to have developed a new-onset depression, to have more severe grief, and to have been closer to the suicide victim. Subjects with PTSD tended to have more severe exposure to suicide and came from discordant households with a history of disruptions in key relationships. The 8 subjects who developed PTSD were compared to 38 subjects who developed new-onset depression but not PTSD. Those with PTSD were more likely to have had past substance abuse, prior suicide attempts, family history of panic disorder, a history of parent-child disruption, and a history of loss. Symptoms of intrusive visual images, hypervigilance, and avoidance of reminders discriminated subjects who had PTSD from new-onset depressives without PTSD. CONCLUSIONS: PTSD is an expectable outcome in youth exposed to suicide. Further work is required to differentiate symptoms of depression from PTSD.

Suicide in affectively ill adolescents: a case-control study.

Sixty-three adolescent suicide victims with a history of affective illness were compared to 23 adolescent community controls with a lifetime history of affective illness, using a case-control design. Suicide victims were more likely to have had major depression, comorbid substance abuse, a past suicide attempt, family history of major depression, treatment with a tricyclic antidepressant, history of legal problems, and a handgun available in the home. There was a non-significant trend for bipolar depression to convey a higher risk for completed suicide than unipolar depression. Recommendations for the prevention of suicide among those with early onset affective illness are discussed in light of these findings.

Major depression or uncomplicated bereavement? A follow-up of youth exposed to suicide.

OBJECTIVE: To determine whether the depressive reactions experienced by youth exposed to suicide were uncomplicated bereavement or major depression by examining the longitudinal risk of recurrent major depression. METHOD: The 121 friends and acquaintances of 26 adolescent suicide victims were followed up 1 to 18 months after an initial interview that took place around 6 months after the death of the suicide victim. A demographically similar group of 138 unexposed controls was also followed up. RESULTS: The median duration of depression in the 37 subjects who became depressed after exposure was 8 months. The exposed group, compared with controls, had a higher rate of incident depression (RR = 1.7, 95% Cl = 1.0-2.8) during the follow-up period, even after adjustment for previous history of depression and other risk factors for depression. Within the group of exposed subjects, the rate of depression on follow-up was highest in those who developed a depressive disorder before exposure to suicide, intermediate in those who developed depression after exposure, and lowest in those who were not depressed at the first interview after exposure. There was no evidence of an increased incidence of suicide attempts in the exposed group relative to the unexposed controls on follow-up. CONCLUSIONS: The depressive reactions observed in youth exposed to suicide are most consistent with major depressive episodes on the basis of course and risk of recurrence. Exposure to suicide was associated with an increased risk of recurrent depression but not with an increased long-term risk of suicidal behavior.

Familial risk factors for adolescent suicide: a case-control study.

Sixty-seven adolescent suicide victims and 67 demographically matched living controls were compared as to family constellation, familial stressors and familial loading for psychopathology. Suicide victims were less likely to have lived with both biological parents, were more likely to be exposed to stressors such as parent-child discord, physical abuse and residential instability and showed greater familial loading for depression and substance abuse. Multivariate analyses showed that family history of both depression and substance abuse and lifetime history of parent-child discord were most closely associated with adolescent suicide. Children who are the offspring of parents with depression or substance abuse should be psychiatrically screened. Family interventions to decrease discord may also be helpful in decreasing the risk of adolescent suicide.

Risk factors for completed suicide among adolescents with a lifetime history of substance abuse: a case-control study.

The risk factors for suicide in adolescents with substance abuse were assessed by comparing 23 adolescent suicide victims and 12 community controls with a lifetime history of definite or probable DSM-III substance abuse. Suicide victims were more likely than controls to show the following risk factors: active substance abuse, comorbid major depression, suicidal ideation within the past week, family history of depression and substance abuse, legal problems and presence of a handgun in the home. Recommendations for the identification and prevention of suicide among substance-abusing youth on the basis of these findings are presented.

Bereavement or depression? The impact of the loss of a friend to suicide.

OBJECTIVE: To determine whether the depressive reactions experienced by youth exposed to suicide were uncomplicated bereavement or bona fide major depression. METHOD: In a sample of 146 friends and acquaintances of 26 adolescent suicide victims, 43 (29%) developed a depressive episode subsequent to exposure to suicide, 18 were depressed before exposure, and 85 were never depressed. The three groups were compared. RESULTS: Those who became depressed after exposure were similar to those who were depressed before exposure. Both depressed groups differed from the nondepressed exposed group with respect to functional impairment, depressive symptom pattern and severity, convergent validity with other measures of depression, personal and family history of depression, and stressful life events. Previous depressives showed greater comorbidity with nonaffective disorders than those who became depressed after exposure. Those who became depressed after exposure compared with both the previous and nondepressive had a closer relationship with the suicide victims, showed more severe grief, and showed more intense exposure to the suicide. CONCLUSIONS: Depressive reactions occurring after exposure to suicide appear to be bona fide major depression, occurring as a complication of bereavement. Youth exposed to suicide should be carefully screened and followed up. Should a symptomatic picture of depression and functional impairment ensue, such exposed youth should be treated accordingly for a major depressive episode.

Adolescent witnesses to a peer suicide.

OBJECTIVE: This case-control study attempts to evaluate the psychological impact of witnessing a suicide on high school students. METHOD: Twenty-eight high school students witnessed a firearms suicide and the serious injury of another student while riding a school bus. They were assessed 2 months after the event, and their responses were compared with 28 demographically similar adolescents from another community who had not been exposed to suicide. RESULTS: The exposed students, when compared with the controls, had higher rates of new-onset anxiety disorder and a trend for increased rates of new-onset post-traumatic stress disorder (PTSD). Within the exposed group, measures of the closeness of the relationship to both the suicide victim and the student who was injured were correlated with the severity of PTSD symptomatology. Within the exposed group, other factors that predisposed to new-onset disorder included family history of affective illness, family history of suicide attempt, and stressful life events occurring in the year before exposure. CONCLUSIONS: In combination with the extant literature, this study demonstrates that adolescents who witness a traumatic suicidal death are at risk for the development of psychopathology, specifically, anxiety disorders and PTSD.