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Biomedical subjects

C Roth

Publications and source records attributed to C Roth.

At least 127 records · Page 7Linked to original sources
PubMed1993

Firearms and adolescent suicide. A community case-control study.

OBJECTIVE: To assess the association between firearms in the home and adolescent suicide. RESEARCH DESIGN: Matched, case-control. SETTING: Population-based community sample. SUBJECTS: Sixty-seven adolescent suicide victims and a demographically matched group of 67 living community controls. SELECTION PROCEDURE: The series of adolescent suicide victims was consecutive, with an overall participation rate of 74% (67/91). MEASUREMENTS AND RESULTS: The presence, type (hand-gun vs long-gun), number, and method of storage (locked vs unlocked, loaded vs unloaded) of firearms in the home were compared between the suicide victims and controls. Even after adjusting for differences in rates of psychiatric disorders between suicide victims and controls, the association between suicide and both any gun (odds ratio [OR] = 4.4, 95% confidence interval [CI] = 1.1 to 17.5) and handguns (OR = 9.4, 95% CI = 1.7 to 53.9) in the home were both highly significant. Long-guns in the home were associated with suicide only in rural areas, whereas handguns were more closely associated with suicide in urban areas. Handguns (OR = 12.9, 95% CI = 1.5 to 110.9) and loaded guns (OR = 32.3, 95% CI = 2.5 to 413.4) in the home were particularly significant risk factors for suicide in those with no apparent psychiatric disorder. CONCLUSIONS: When pediatricians are faced with a suicidal adolescent, they should insist on the removal of firearms from the home. Pediatricians should also inform parents that the presence of firearms may be associated with adolescent suicide even in the absence of clear psychiatric illness.

Adolescent↗
PubMed1993

Psychiatric impact of the loss of an adolescent sibling to suicide.

Twenty-five adolescent siblings of 20 adolescent suicide victims were psychiatrically assessed 6 months after the suicide, and compared to 25 demographically matched controls. Siblings were much more likely to show a new-onset major depression subsequent to exposure to suicide. New-onset depression was associated with previous psychiatric disorder, family history of any psychiatric disorder, and family history of major depression. Mothers of suicide victims, compared to the mothers of controls, were also more likely to be depressed 6 months after the suicide of their child. The development of a family-based intervention for families of adolescent suicides is recommended.

Adaptation, Psychological↗
PubMed1993

RNA virus-like particles in pathogenic plant trypanosomatids.

A double-stranded RNA (ds RNA) with an approximate size of 4.7 kb was found in 6 Phytomonas isolates specifically associated with plant pathogenicity in coconut trees ("Hartrot" disease) and oil palm ("Marchitez sorpressiva" disease). This ds RNA was not detected in 10 non-pathogenic Phytomonas isolates from different lactiferous plants or in the insect trypanosomatids Crithidia and Herpetomonas. Analysis by electron microscopy of a sucrose gradient fraction containing this ds RNA revealed virus-like particles.

Animals↗
PubMed1993

Psychiatric sequelae to the loss of an adolescent peer to suicide.

OBJECTIVE: This study was designed to learn whether friends and acquaintances of suicide victims were at increased risk for depression, post-traumatic stress disorder, and suicidal behavior after exposure to suicide. METHOD: The social networks of 26 adolescent suicide victims, consisting of 146 adolescents, were interviewed 7 months after the death of the suicide victim and compared with 146 matched, unexposed controls. RESULTS: The rates of these disorders that had onset after exposure were elevated in the exposed group vs. controls: major depression, post-traumatic stress disorder, suicidal ideation with a plan or an attempt, but not suicidal attempts. Almost all of those exposed youth who developed new-onset suicidality did so in the context of a new-onset depressive episode. The majority of these new-onset depressive disorders began within 1 month of exposure. CONCLUSION: Postvention programs not only should focus on the prevention of imitation of suicidal behavior, but also should provide longer term follow-up for potentially bereaved and depressed youth exposed to suicide.

Adolescent↗
PubMed1993

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

OBJECTIVE: The objective of this study was to determine the psychiatric risk factors for adolescent suicide. METHOD: Sixty-seven adolescent suicide victims were compared with 67 demographically matched community controls. Psychiatric disorder was assessed in suicide victims using a psychological autopsy protocol and in controls using similar semistructured psychiatric interviews. Risk factors were quantified by use of the odds ratio (OR), that is, the relative frequency of the occurrence of a given condition in the suicides compared with the controls. RESULTS: The most significant psychiatric risk factors associated with adolescent suicide were major depression (OR = 27.0), bipolar mixed state (OR = 9.0), substance abuse (OR = 8.5), and conduct disorder (OR = 6.0). Substance abuse was a more significant risk factor when comorbid with affective illness than when alone (OR = 17.0 versus 3.3). The majority of depressed suicide victims had a primary affective disorder (82%). A significant minority (31%) of depressed suicide victims had been depressed less than 3 months. Previous suicide attempts, suicidal ideation, and homicidal ideation also were associated with adolescent suicide. CONCLUSIONS: The development of effective treatments for youth who fit the above-noted risk profiles should be given high priority.

Adolescent↗
PubMed1993

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.

Adolescent↗
PubMed1993

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↗
PubMed1993

The validity of diagnoses obtained through the psychological autopsy procedure in adolescent suicide victims: use of family history.

A test of validity of the psychiatric diagnoses obtained by the psychological autopsy procedure is described in a consecutive series of 67 adolescent suicide victims. Family history of mental illness in first-degree relatives of subjects was obtained blind to subject diagnosis using the family history method. It was hypothesized that subjects with a given diagnosis, compared with subjects without this diagnosis, would show an increased rate of this disorder among first-degree relatives. This hypothesis was supported insofar as specific associations between subject diagnosis and familial rates of illness were demonstrated for major depression, bipolar illness, conduct and antisocial disorder and substance abuse. These results provide further support for the validity of diagnoses obtained through the psychological autopsy procedure.

Adolescent↗
PubMed1993

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.

Adolescent↗
PubMed1993

Effects of steroid and lactogenic hormones on islets of Langerhans: a new hypothesis for the role of pregnancy steroids in the adaptation of islets to pregnancy.

Adaptive changes that occur in islets of Langerhans during pregnancy include enhanced insulin secretion, insulin synthesis, beta-cell proliferation, gap-junctional coupling among beta-cells, and glucose oxidation. We have determined that elevated lactogenic activity is directly responsible for these changes in beta-cell function. Recently, we showed that two of the principal adaptive characteristics (insulin secretion and beta-cell proliferation) of rat pregnancy peaked on day 15 and returned to control levels by day 20. As placental lactogen remains elevated during late gestation, it was of interest to determine whether pregnancy steroids could reverse the effects of lactogen on islets. In this study, rat islets were cultured with progesterone, estradiol, rat PRL (rPRL), or combinations of these hormones (progesterone and rPRL, estradiol and rPRL, or progesterone and estradiol and rPRL). Insulin secretion was examined for 8 days, and beta-cell proliferation by 2-bromo-5'-deoxyuridine (BrdU) incorporation on days 4 and 8. rPRL treatment resulted in a time-dependent increase in insulin secretion that was 3-fold greater than that from control islets by day 8. Progesterone and estradiol had minimal effects on insulin secretion. Estradiol had no effect on the increased insulin secretion observed with rPRL during the first 6 days and a small inhibitory effect on days 7 and 8. Although progesterone treatment had no effect on the increased insulin secretion induced by rPRL during the first 3 days, it subsequently resulted in a decline in insulin secretion to that from control islets. The combination of progesterone and estradiol was more effective than either steroid by itself in reversing the effects of rPRL on insulin secretion. Similar results were obtained in the BrdU labeling experiments: 1) a 7-fold increase in the number of BrdU-labeled nuclei per islet was observed after culture in the presence of rPRL; and 2) estradiol had a small inhibitory effect on the increased BrdU labeling observed with rPRL; however, 3) progesterone completely reversed the effect of rPRL on islet beta-cell division. These results demonstrate that progesterone counterregulates the effects of PRL on insulin secretion and islet beta-cell division. The temporal changes observed in islets in vitro under the influence of PRL and progesterone mimic those seen in islets during pregnancy. We conclude that progesterone, which increases in the later stages of gestation, is the primary hormone responsible for counteracting the stimulatory effects of elevated lactogenic activity on islets during late pregnancy.

Animals↗
PubMed1993

Stressful life events, psychopathology, and adolescent suicide: a case control study.

The relationship between stressful life events and adolescent suicide was assessed in 67 adolescent suicide victims and 67 matched community controls. In the year before death, suicide completers were more likely to have experienced: (1) interpersonal conflict with parents and with boy/girlfriends, (2) disruption of a romantic attachment, (3) legal or disciplinary problems. Legal or disciplinary problems were more commonly associated with suicide in conduct and substance abuse disordered youth. Interpersonal loss was more commonly associated with suicide in substance abuse as well. Even after controlling for psychopathology, legal and disciplinary problems in the past year were associated with an increased risk of suicide.

Adolescent↗
PubMed1992

Inhibition of tumor growth by histoincompatible cells expressing interleukin-2.

Murine tumor cells engineered to express IL-2 have been shown to be rejected by the syngeneic host, which is then protected against a subsequent tumorigenic challenge. To assess whether IL-2 has to be produced by the tumor cells themselves, or whether its local delivery would be sufficient to promote such beneficial effects, the syngeneic tumor cells were co-inoculated with allogeneic or xenogeneic cells secreting IL-2, selected after gene transfection. In several murine systems, it was observed that this is an efficient approach for controlling the growth of the syngeneic tumor. However, animals which rejected the tumor were not protected against a subsequent challenge. Several lines of evidence indicate that NK cells play a major role in tumor rejection induced by the IL-2 expressing histoincompatible vector cells. Thus, while local delivery of IL-2 in the vicinity of a tumor might not be sufficient to promote a systemic long-term specific antitumor immune response, it can control the growth of the primary syngeneic tumor. These experiments demonstrate the feasibility of using genetically engineered histoincompatible cells (which are rejected by the host's immune system) as a transient delivery system in vivo.

Animals↗
PubMed1992

Psychiatric effects of exposure to suicide among the friends and acquaintances of adolescent suicide victims.

The friends and acquaintances (N = 58) of 10 adolescent suicide victims were interviewed 6 months after the death of the victims, and the rates of psychiatric disorders that had onset after the death were compared with the 6-month incidence of psychopathology in 58 demographically and psychiatrically matched unexposed controls. The exposed group showed higher rates of any new onset major depressive disorder, but the rate of incident suicide attempts was the same in both groups. The median onset of incident depression among the exposed group was within the first month after exposure, and the majority of those exposed youth with incident depression were still depressed at interview 6 months after the death. Adolescent friends and acquaintances of suicide victims experience considerable psychiatric morbidity subsequent to exposure to suicide, most consistent with pathological grief.

Adolescent↗
PubMed1992

[Potentiation of the antitumoral effect of electrochemotherapy by immunotherapy with allogeneic cells producing interleukin 2].

Electrochemotherapy (ECT) is a new antitumour treatment which consists of delivering electric pulses to the tumour a few minutes after an intravenous injection of bleomycin. The antitumour efficacy of ECT is increased by local injections of interleukin 2 (IL2) in the oedema which appears at the site of the treated tumours. We have shown that tumour cells inoculated in syngeneic mice are rejected if IL2 secreting allo- or xenogeneic cells are co-injected with tumour cells. We report here the large increase of ECT therapeutical efficacy when allogeneic cells secreting IL2 are injected into the peri-tumoural oedema.

Animals↗