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Biomedical subjects

P Ambrosini

Publications and source records attributed to P Ambrosini.

At least 19 recordsLinked to original sources
PubMed1996

Resorption rates of 2 commercially available bioresorbable membranes. A histomorphometric study in a rabbit model.

The respective resorption rates of recently commercialized collagen versus polylactic acid-citric acid ester membranes were compared. 16 rabbits were implanted with 2 mm x 4 mm pieces of membrane of both types in the alveolar mucosa just apically to the incisors on either side of the mouth. 1 animal was sacrificed on day 0, just after the operation. The others were sacrificed at 1, 2, 3, 5, 7, 9 and 12 weeks. The specimens were prepared for histologic examination. Observations showed that the cross-linked collagen membranes induced severe inflammation and were resorbed within 2 weeks. The polylactic acid-citric acid ester polymer barriers produced a much more moderate infiltrate and were still not totally resorbed at 12 weeks. Although resorption rates in the rabbit may not be similar to those observed in humans, it seems that the durability of the polymer barrier is more adequate for guided tissue regeneration than the cross-linked collagen.

Animals↗
PubMed1994

The 24-hour pattern of prolactin secretion in depressed and normal adolescents.

Plasma prolactin concentrations were measured at 20-min intervals over a 24-hr period in 49 adolescents with major depressive disorder (MDD) and 39 normal control adolescents. Neither the pattern nor the amount of prolactin secretion was significantly different between these two groups. There were significant gender differences, with girls secreting more prolactin than boys, but no significant gender-by-diagnosis interactions were found. With the possible exception of psychosis, dividing the MDD sample based on clinical characteristics failed to reveal differences. These findings are discussed in the context of changes in prolactin in childhood depression using a serotonergic challenge study, as well as in relation to baseline prolactin studies in adult depression.

Adolescent↗
PubMed1993

The psychosocial functioning and family environment of depressed adolescents.

OBJECTIVE: This study examined measures of functional impairment and family relations in a sample of 62 adolescents with major depressive disorder (MDD) and 38 normal controls with no history of psychiatric illness. METHOD: Ratings of the following domains were obtained: mother-child relations, father-child relations, spousal relations, sibling relations, peer relations, and school performance. Ratings of each domain for the 3-month period preceding the assessment were derived from information obtained using a semistructured interview administered independently to the adolescents and one of their parents. RESULTS: Adolescents with MDD were found to have severe difficulties in all areas. Ninety percent of the depressed adolescents had scores greater than 2 SD above the mean of the normal controls on one or more of the domain ratings. In addition, adolescents with difficulties in parent-child relations were more likely than those adolescents without problems in family relations to have difficulties in peer relations and school performance. CONCLUSIONS: The authors discuss the importance of systematically examining psychosocial variables in future studies of the etiology, course, and treatment of MDD in adolescents.

Adolescent↗
PubMed1992

Dexamethasone suppression test in children with major depressive disorder.

The authors report a study of 24-hour serial cortisol determinations, measured during baseline and after the administration of 0.25 and 0.5 mg of dexamethasone in a sample of predominantly outpatient children with major depressive disorder, nonaffective psychiatric controls, and normal controls. In this sample, 24-hour baseline cortisol and the dexamethasone suppression test (DST) do not discriminate between the three groups. In addition, the authors measured 24-hour serum dexamethasone levels. There were no significant between group differences in serum dexamethasone. These results raise questions as to the utility of this test in the diagnosis of affective disorders in children. Possible reasons for the discrepancies in the dexamethasone suppression test results between in- and outpatient studies are discussed.

Administration, Oral↗
PubMed1992

The dexamethasone suppression test in adolescent outpatients with major depressive disorder.

OBJECTIVE: The purpose of the study was to determine whether the dexamethasone suppression test (DST) would discriminate between outpatient adolescents with major depressive disorder and normal adolescent comparison subjects. METHOD: Depressed patients were accepted into the study only if they fulfilled the Research Diagnostic Criteria for major depressive disorder. The depressed subjects (N = 44) and the normal subjects (N = 38) were studied in the same environment and under the same conditions. The subjects received 1 mg of dexamethasone at 11:00 p.m. The next day, blood for determining plasma cortisol concentrations was drawn through an indwelling catheter every 60 minutes from 8:00 a.m. until 11 p.m. RESULTS: After dexamethasone, the cortisol levels of the adolescents with major depressive disorder and the normal subjects were not significantly different. Only six (14%) of the depressed subjects and one (3%) of the normal subjects showed evidence of nonsuppression (cortisol value greater than 5 micrograms/dl). Analyses of subgroups of the depressed patients based on suicidal tendencies and endogenous subtype also failed to reveal significant differences in cortisol values. Estimates of the severity of depression showed significant negative correlations with cortisol values among the depressed patients. CONCLUSIONS: In contrast with previous studies of adolescent inpatients, the DST did not discriminate between the adolescent outpatients with major depressive disorder and the normal comparison subjects in this study. Possible reasons for the discrepancies, such as severity of the depression and inpatient status, are discussed.

Adolescent↗
PubMed1991

Thyroid stimulating hormone response to thyrotropin in prepubertal depression.

In an effort to evaluate whether differences exist in the hypothalamic-pituitary-thyroid axis of depressed children, a thyrotropin releasing hormone (TRH) stimulation test was administered to 55 prepubertal subjects who were divided into three groups matched for age and sex: a depressed group (endogenous N = 15, nonendogenous N = 15), a psychiatric nondepressed control group (N = 16), and a normal control group (N = 9). Each subject was tested at two dosages of TRH, 2 micrograms/kg and 7 micrograms/kg. Increasing age and female sex were positively correlated with a greater thyroid stimulating hormone (TSH) response. TSH response to TRH was examined with subjects reclassified by severe suicidal ideation, severe aggression, and parental history of alcoholism. Results of this study are contrasted with the adult psychiatric literature.

Age Factors↗
PubMed1990

[In vitro study of the cytocompatibility of 3 biological glues].

Human derived fibrin glues are being used with increasing frequency in periodontal surgery. Three different fibrin glues were tested in an in vitro system for gingival fibroblast proliferation. The results show a cytocompatibility of these products which justifies their employment in periodontal therapy.

Biocompatible Materials↗
PubMed1987

The clinical picture of major depression in children and adolescents.

Symptom frequency and severity were compared in two sequential clinically referred samples of 95 children and 92 adolescents, aged 6 to 18 years, all medically healthy, assessed with the Schedule for Affective Disorders and Schizophrenia for School Age Children, Present Episode, who met unmodified Research Diagnostic Criteria for major depressive disorder (MDD). There were no significant differences between the two groups in the majority of depressive symptoms. However, prepubertal children had greater depressed appearance, somatic complaints, psychomotor agitation, separation anxiety, phobias, and hallucinations, whereas adolescents had greater anhedonia, hopelessness, hypersomnia, weight change, use of alcohol and illicit drugs, and lethality of suicide attempt, but not severity of suicidal ideation or intent. Adolescents with a duration of the depressive episode of two years or greater had significantly higher rates of suicidal ideation and intent, lethality, and number of suicide attempts than youngsters with depressive episodes of shorter duration. A principal components factor analysis of psychiatric symptoms was carried out in all 296 youngsters evaluated during the same period who met DSM-III criteria for any Axis I diagnosis. The majority had an affective disorder. Factors were quite similar for both adolescents and children and included an "endogenous" and an "anxious" factor, as in many studies of adult depression. In addition, three other factors were found: negative cognitions, appetite and weight changes, and a conduct factor. Suicidal ideation was a component of both the negative cognitions factor and the conduct factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Imipramine in adolescent major depression: plasma level and clinical response.

Thirty-four adolescents with mean age 14.25 years who met RDC criteria for major depressive disorder as assessed with the K-SADS, were treated for 6 weeks on a fixed schedule of imipramine hydrochloride titrated to a dosage of 5.0 mg/kg/day except as limited by side effects. Mean dose was 246 mg/day (4.5 mg/kg/day). In spite of good indications of compliance with treatment only 44% of the adolescents improved to the level of no or only slight depressed mood or anhedonia, though most had less depressive symptomatology at the end of treatment. There was neither a linear nor curvilinear relationship between total plasma level of IMI plus DMI and clinical response, despite a wide range of both plasma level (77 ng/ml to 986 ng/ml) and outcome. Adolescents with associated separation anxiety had significantly poorer response to treatment of their depressive disorder than those with major depression alone. Poor response was also weakly associated with being female, having endogenous subtype of depression, and having higher plasma IMI (but not DMI) level. In the context of similar studies of IMI on depression in other age groups, it is hypothesized that high levels of sex hormones during adolescence and young adulthood may interfere with IMI's antidepressant effects. It is concluded that other types of antidepressants should be tested in adolescents with major depression.

Adolescent↗
PubMed1985

Molindone hydrochloride treatment of hospitalized children with conduct disorder.

Treatment-emergent symptoms and behavioral changes were assessed during an 8-week double-blind study comparing molindone and thioridazine in 31 aggressive hospitalized children (ages 6-11). Molindone was found to be as effective as thioridazine in this sample. Adverse effects differed (nonsignificantly) for the two groups, with more sedation in the thioridazine-treated children. Clinical records from 6 adolescent inpatients treated with molindone were reviewed as a comparison group. Molindone is a relatively safe neuroleptic for child and adolescent inpatients because of its short half-life and minimal prolonged tissue accumulation. Additional studies on different child populations are necessary before the proper indications for molindone usage in the pediatric group can be established.

Adolescent↗