How to Open the Door: A Qualitative, Observational Study on Initiating Advance Care Discussions with Parents in Pediatric Palliative Care

Context: Advance care discussions (ACD) between health care professionals (HCPs) and parents of children with a life-limiting disease are a core element of successful pediatric advance care planning (pACP). Yet, they are perceived as a challenging situation for all participants. Objectives: Our goal was to investigate the first step of ACD and identify its challenges and helpful communication strategies to develop a conversation guide for initiating the pACP process and structure the conversational opening. Methods: We performed a participant observation of 11 initial ACD and 24 interviews with 13 HCPs and 20 parents of 11 children cared for by 3 different palliative care teams in southern Germany. Qualitative data collection was supplemented by a questionnaire. Content analysis and conversation analysis were used for evaluation. Results: Parents and HCPs start the process with different expectations, which can lead to misunderstandings and confusion. HCPs gain parental cooperation when they express the purpose of the meeting clearly and early, provide structure and guidance, and give parents time to talk about their experiences and feelings. Addressing dying and death is hard for both sides and requires a sensitive approach. Conclusions: Initiating ACD is extremely challenging for all participants. HCPs and parents should clarify expectations and aims at the beginning of the conversation. Future research should focus on how HCPs can be trained for this task and how the right timing for introducing ACD to families can be identified. Clinical Trial Registration number 049-12.

Structural and Functional Studies of the RBPJ-SHARP Complex Reveal a Conserved Corepressor Binding Site

Notch is a conserved signaling pathway that is essential for metazoan development and homeostasis; dysregulated signaling underlies the pathophysiology of numerous human diseases. Receptor-ligand interactions result in gene expression changes, which are regulated by the transcription factor RBPJ. RBPJ forms a complex with the intracellular domain of the Notch receptor and the coactivator Mastermind to activate transcription, but it can also function as a repressor by interacting with corepressor proteins. Here, we determine the structure of RBPJ bound to the corepressor SHARP and DNA, revealing its mode of binding to RBPJ. We tested structure-based mutants in biophysical and biochemical-cellular as-says to characterize the role of RBPJ as a repressor, clearly demonstrating that RBPJ mutants deficient for SHARP binding are incapable of repressing transcription of genes responsive to Notch signaling in cells. Altogether, our structure-function studies provide significant insights into the repressor function of RBPJ.

Yuan et al. determine the X-ray structure of the corepressor SHARP bound to RBPJ, the nuclear effector of the Notch pathway. The structure-function analysis provides insights into corepressor binding to RBPJ and how RBPJ functions as a repressor of transcription of Notch target genes.

Identifying key elements for paediatric advance care planning with parents, healthcare providers and stakeholders: A qualitative study

BACKGROUND

Although international guidelines recommend discussions about goals of care and treatment options for children with severe and life-limiting conditions, there are still few structured models of paediatric advance care planning.

AIM

The study aimed at identifying key components of paediatric advance care planning through direct discussions with all involved parties.

DESIGN

The study had a qualitative design with a participatory approach. Participants constituted an advisory board and took part in two transdisciplinary workshops. Data were collected in discussion and dialogue groups and analysed using content analysis.

SETTING/PARTICIPANTS

We included bereaved parents, health care providers and stakeholders of care networks.

RESULTS

Key elements were discussions, documentation, implementation, timing and participation of children and adolescents. Parents engage in discussions with facilitators and persons of trust to reach a decision. Documentation constitutes the focus of professionals, who endorse brief recommendations for procedures in case of emergencies, supplemented by larger advance directives. Implementation hindrances include emotional barriers of stakeholders, disagreements between parents and professionals and difficulties with emergency services. Discussion timing should take into account parental readiness. The intervention should be repeated at regular intervals, considering emerging needs and increasing awareness of families over time. Involving children and adolescents in advance care planning remains a challenge.

CONCLUSION

A paediatric advance care planning intervention should take into account potential pitfalls and barriers including issues related to timing, potential conflicts between parents and professionals, ambiguity towards written advance directives, the role of non-medical carers for paediatric advance care planning implementation, the need to involve the child and the necessity of an iterative process.

Histone variant H2A.Z deposition and acetylation directs the canonical Notch signaling response

A fundamental as yet incompletely understood feature of Notch signal transduction is a transcriptional shift from repression to activation that depends on chromatin regulation mediated by transcription factor RBP-J and associated cofactors. Incorporation of histone variants alter the functional properties of chromatin and are implicated in the regulation of gene expression. Here, we show that depletion of histone variant H2A.Z leads to upregulation of canonical Notch target genes and that the H2A.Z-chaperone TRRAP/p400/Tip60 complex physically associates with RBP-J at Notch-dependent enhancers. When targeted to RBP-J-bound enhancers, the acetyltransferase Tip60 acetylates H2A.Z and upregulates Notch target gene expression. Importantly, the Drosophila homologs of Tip60, p400 and H2A.Z modulate Notch signaling response and growth in vivo. Together, our data reveal that loading and acetylation of H2A.Z are required to assure tight control of canonical Notch activation.

Perinatal Palliative Care: A qualitative study evaluating the perspectives of pregnancy counselors

BACKGROUND

A prenatal diagnosis of a life-limiting disease raises complex ethical, emotional, and medical issues. Studies suggest that 40%-85% of parents decide to continue the pregnancy if given the option of Perinatal Palliative Care. However, structured Perinatal Palliative Care programs are missing in many European countries. In Germany, parents have the right to free psychosocial support from pregnancy counseling services after the prenatal diagnosis of a life-limiting disease.

AIM

We aimed to investigate whether German professional pregnancy counselors perceive the need for structured Perinatal Palliative Care and if so, how it should be conceived.

DESIGN

This is a qualitative interview study with purposeful sampling. The interviews were analyzed with the coding method of Saldaña.

SETTING/PARTICIPANTS

A total of 10 professionals from three different pregnancy counseling services participated in the study.

RESULTS

The main topics raised by the professionals were as follows: (1) counseling and parental support during the decision-making process; (2) fragmented or missing support infrastructure for parents; and (3) challenges, hesitations, and barriers, particularly from the different stakeholders, regarding a Perinatal Palliative Care framework. They highlighted the importance of the integration of Perinatal Palliative Care in existing structures, a multi-professional approach, continuous coordination of care and education for all healthcare providers involved.

CONCLUSION

A structured Perinatal Palliative Care program is considered as necessary by the pregnancy counselors. Future research should focus on (1) needs reported by concerned parents; (2) attitude and role of all healthcare providers involved; (3) strategies to include stakeholders in the development of Perinatal Palliative Care networks; and (4) outcome parameters for evaluation of Perinatal Palliative Care frameworks.

A phospho-dependent mechanism involving NCoR and KMT2D controls a permissive chromatin state at Notch target genes

The transcriptional shift from repression to activation of target genes is crucial for the fidelity of Notch responses through incompletely understood mechanisms that likely involve chromatin-based control. To activate silenced genes, repressive chromatin marks are removed and active marks must be acquired. Histone H3 lysine-4 (H3K4) demethylases are key chromatin modifiers that establish the repressive chromatin state at Notch target genes. However, the counteracting histone methyltransferase required for the active chromatin state remained elusive. Here, we show that the RBP-J interacting factor SHARP is not only able to interact with the NCoR corepressor complex, but also with the H3K4 methyltransferase KMT2D coactivator complex. KMT2D and NCoR compete for the C-terminal SPOC-domain of SHARP. We reveal that the SPOC-domain exclusively binds to phosphorylated NCoR. The balance between NCoR and KMT2D binding is shifted upon mutating the phosphorylation sites of NCoR or upon inhibition of the NCoR kinase CK2β. Furthermore, we show that the homologs of SHARP and KMT2D in Drosophila also physically interact and control Notch-mediated functions in vivo. Together, our findings reveal how signaling can fine-tune a committed chromatin state by phosphorylation of a pivotal chromatin-modifier.

Site-specific methylation of Notch1 controls the amplitude and duration of the Notch1 response

Physiologically, Notch signal transduction plays a pivotal role in differentiation; pathologically, Notch signaling contributes to the development of cancer. Transcriptional activation of Notch target genes involves cleavage of the Notch receptor in response to ligand binding, production of the Notch intracellular domain (NICD), and NICD migration into the nucleus and assembly of a coactivator complex. Posttranslational modifications of the NICD are important for its transcriptional activity and protein turnover. Deregulation of Notch signaling and stabilizing mutations of Notch1 have been linked to leukemia development. We found that the methyltransferase CARM1 (coactivator-associated arginine methyltransferase 1; also known as PRMT4) methylated NICD at five conserved arginine residues within the C-terminal transactivation domain. CARM1 physically and functionally interacted with the NICD-coactivator complex and was found at gene enhancers in a Notch-dependent manner. Although a methylation-defective NICD mutant was biochemically more stable, this mutant was biologically less active as measured with Notch assays in embryos of Xenopus laevis and Danio rerio. Mathematical modeling indicated that full but short and transient Notch signaling required methylation of NICD.

Wnt/β-catenin signaling regulates telomerase in stem cells and cancer cells

Telomerase activity controls telomere length and plays a pivotal role in stem cells, aging, and cancer. Here, we report a molecular link between Wnt/β-catenin signaling and the expression of the telomerase subunit Tert. β-Catenin-deficient mouse embryonic stem (ES) cells have short telomeres; conversely, ES cell expressing an activated form of β-catenin (β-cat(ΔEx3/+)) have long telomeres. We show that β-catenin regulates Tert expression through the interaction with Klf4, a core component of the pluripotency transcriptional network. β-Catenin binds to the Tert promoter in a mouse intestinal tumor model and in human carcinoma cells. We uncover a previously unknown link between the stem cell and oncogenic potential whereby β-catenin regulates Tert expression, and thereby telomere length, which could be critical in human regenerative therapy and cancer.

Two proteolytic modules are involved in regulated intramembrane proteolysis of Bacillus subtilis RsiW

Stress-induced degradation of the Bacillus subtilis anti-sigma factor RsiW results in the induction of genes controlled by the extracytoplasmic function sigma factor sigma(W). RsiW is cleaved by the mechanism of regulated intramembrane proteolysis at site-1 and -2 by PrsW and RasP respectively, and is then further degraded by cytoplasmic Clp peptidases. In a reconstituted Escherichia coli system, PrsW removes 40 amino acids from RsiW by cleaving between Ala168 and Ser169 of the extracytoplasmic domain, thereby generating RsiW-S1. Further trimming of RsiW-S1's C-terminus by the periplasmic tail-specific protease Tsp is crucial for subsequent RasP-catalysed clipping. In B. subtilis, mutation of RsiW at Ala168 severely impairs site-1 processing. RsiW-S1 is undetectable in wild-type B. subtilis and knockout strains lacking various extracytoplasmic proteases. While it can be stabilized by C-terminal tagging, even this fusion protein is still attacked. Thus, several peptidases seem to be involved in trimming of RsiW downstream of PrsW and upstream of RasP in B. subtilis. Overall, the RsiW degradation pathway can be subdivided into two modules each consisting of a site-specific peptidase that prepares RsiW for further degradation by downstream proteases.

Hippocampal interneurons co-express transcripts encoding the alpha7 nicotinic receptor subunit and the cannabinoid receptor 1

The notion of functional interactions between the alpha7 nicotinic acetylcholine (alpha7 nACh) and the cannabinoid systems is emerging from recent in vitro and in vivo studies. Both the alpha7 nACh receptor and the cannabinoid receptor 1 (CB1) are highly expressed in the hippocampus. To begin addressing possible anatomical interactions between the alpha7 nACh and the cannabinoid systems in the rat hippocampus, we investigated the distribution of neurons expressing alpha7 nACh mRNA in relation to those containing CB1 mRNA. By in situ hybridization we found that the alpha7 nACh mRNA is diffusely expressed in principal neurons and is highly expressed in a subset of interneurons. We observed that the pattern of distribution of hippocampal interneurons co-expressing transcripts encoding alpha7 nACh and glutamate decarboxylase (GAD; synthesizing enzyme of GABA) closely resembles the one displayed by interneurons expressing CB1 mRNA. By double in situ hybridization we established that the majority of hippocampal interneurons expressing alpha7 nACh mRNA have high levels of CB1 mRNA. As CB1 interneurons contain cholecystokinin (CCK), we investigated the degree of cellular co-expression of alpha7 nACh mRNA and CCK, and found that the cellular co-existence of alpha7 nACh and CCK varies within the different layers of the hippocampus. In summary, we established that most of the hippocampal alpha7 nACh expressing interneurons are endowed with CB1 mRNA. We found that these alpha7 nACh/CB1 interneurons are the major subpopulation of hippocampal interneurons expressing CB1 mRNA. The alpha7 nACh expressing interneurons represent half of the detected population of CCK containing neurons in the hippocampus. Since it is well established that the vast majority of hippocampal interneurons expressing CB1 mRNA have 5-HT type 3 (5-HT3) receptors, we conclude that these hippocampal alpha7 nACh/5HT3/CB1/CCK interneurons correspond to those previously postulated to relay inputs from diverse cortical and subcortical regions about emotional, motivational, and physiological states.

An extrachromosomal switch recombination substrate reveals kinetics and substrate requirements of switch recombination in primary murine B cells

Ig class switch recombination occurs in B lymphocytes upon activation, and is targeted to distinct switch (S) regions by cytokine-mediated induction of switch transcripts spanning the entire S region and the adjacent constant region gene segments. Using a novel type of switch recombination substrate, constructed according to the intron-exon structure of the IgH locus, but with heterologous elements, we here have tested the structural requirements for targeting and the kinetics of switch recombination in activated primary murine B cells. When transfected at various times after activation, up to 10% of the transfected B cells perform recombination of the substrate within 12 h. Switch recombination in primary B cells is restricted to the first 72 h after onset of activation, then rapidly decreases to background levels, as obtained in plasmacytoma cells or with substrates carrying no S region sequences. In terms of structural requirements, switch recombination is targeted to any transcription unit that contains an intronic S region and depends on processing of the primary transcript by splicing.

Processing of switch transcripts is required for targeting of antibody class switch recombination

Antibody class switching is mediated by somatic recombination between switch regions of the immunoglobulin heavy chain gene locus. Targeting of recombination to particular switch regions is strictly regulated by cytokines through the induction of switch transcripts starting 5' of the repetitive switch regions. However, switch transcription as such is not sufficient to target switch recombination. This has been shown in mutant mice, in which the I-exon and its promoter upstream of the switch region were replaced with heterologous promoters. Here we show that, in the murine germline targeted replacement of the endogenous gamma1 promoter, I-exon, and I-exon splice donor site by heterologous promoter and splice donor sites directs switch recombination in activated B lymphocytes constitutively to the gamma1 switch region. In contrast, switch recombination to IgG1 is inhibited in mutant mice, in which the replacement does not include the heterologous splice donor site. Our data unequivocally demonstrate that targeting of switch recombination to IgG1 in vivo requires processing of the Igamma1 switch transcripts. Either the processing machinery or the processed transcripts are involved in class switch recombination.

Molecular analysis and mapping of two genes encoding maize glutathione S-transferases (GST I and GST II)

Maize glutathione S-transferase (GST) isozymes are encoded by a gene family comprising at least five genes, three of which (Gst I, II and III) have recently been isolated and sequenced. The enzymes are active as homo or heterodimers and exhibit intraspecific polymorphism including a "null" variant for the two major isoforms expressed in roots. Northern blot analyses performed on total root RNA from "null" and "plus" genotypes, using Gst I- and Gst II-specific probes, indicated that the Gst I gene controls the expression of the two major GST isoforms expressed in roots. Gst I and Gst II were mapped by RFLP analysis using an F2 population of 149 individuals previously characterized. Gst I was localized on the long arm of chromosome 8, while two putative Gst II loci were mapped to chromosome 8 (70 cM from Gst I) and 10, respectively.

Comparison of HIV+ and HIV- adolescents: risk factors and psychosocial determinants

According to the World Health Organization, half of the 14 million people with human immunodeficiency virus (HIV) worldwide were infected between the ages of 15 and 24 years. However, details about HIV-positive (HIV+) youths' risk-related behavior and social context have not been previously reported. OBJECTIVES. To outline detailed sexual and drug use practices, social and psychological status of HIV+ youth compared with a cohort of HIV-negative (HIV-) youth; and to examine the ability of the health belief and risk-taking models to predict sexual and drug use acts of HIV+ youth. METHODS. HIV testing was conducted on and a 207-item structured interview covering HIV risk-related acts, protective factors and background information was administered to 72 HIV+ and 1142 HIV- adolescents aged 13 through 21 years receiving care in an adolescent clinical care unit of a large medical center in New York City. Data were analyzed for adolescents reporting sexual intercourse (71 HIV+ and 722 HIV-) by logistic regression analysis of five domains to identify variables significantly associated with HIV seropositivity. RESULTS. Logistic regressions indicated significant differences in sexual risk acts based on serostatus and gender. Anonymous, blinded seroprevalence testing identified 11% more HIV+ adolescents than would have been identified by current counseling and testing practices. HIV+ adolescents were significantly more likely to be sexually abused (33 vs 21%, P < .05), engage in anal sex and survival sex (32 vs 4%, P < .01), unprotected sex with casual partners (42 vs 23%, P < .05), have had sex under the influence of drugs (52 vs 27%, P < .01), have a sexually transmitted disease (59 vs 28%, P < .01), use multiple drugs (43 vs 9%, P < .01) and engage in multiple problem behaviors (72 vs 30%, P < .01) than HIV- young people. HIV+ females reported more oral (69 vs 45%, P < .01) and/or anal (42 vs 12%, P < .01) intercourse compared to HIV- females. HIV+ males reported significantly higher rates of both insertive (82 vs 46%, P < .05) and receptive (51 vs 4%, P < .01) oral and anal (53 vs 13%, P < .01) intercourse than HIV- males. Protective factors were not significantly different for HIV+ and HIV- young people. CONCLUSIONS. Routine, confidential HIV counseling and testing should be considered for adolescents having unprotected sexual intercourse when age-specific services are available for HIV+ youth. Prevention programs should consider adolescents' history of abuse, homelessness, and other social as well as psychological dimensions in designing comprehensive care strategies to address HIV+ adolescents' multiple problem behaviors and living situations. Current theoretical models of health behaviors should be reconsidered, given the lack of their association to HIV risk acts of HIV+ youth. Age-specific services and interventions for HIV+ youth are urgently needed as HIV is spreading among youth worldwide.

An evaluation of an AIDS risk reduction education and skills training (ARREST) program

PURPOSE

With the increasing rate of HIV infection among adolescents, there is an urgent need for interventions that will provide teenagers with information, the ability to make decisions, and the assertiveness and communication skills required for effective prevention and risk reduction. This study evaluated an AIDS Risk Reduction Education and Skills Training (ARREST) program designed for adolescents, ages 12-16 years.

METHODS

Eighty-seven inner-city, African-American (36%) and Latino (55%) adolescents were recruited from community-based after-school programs, and randomly assigned to either the ARREST intervention or a wait-list control group. Adolescents assigned to the ARREST intervention participated in three 90-minute intervention sessions. ARREST was evaluated by comparing pre- and post-test scores on a battery of self-report measures and videotaped role-play simulations.

RESULTS

Analyses revealed significant post-test differences between the ARREST and wait-list control groups, with teens in the ARREST group demonstrating significant changes in knowledge and negative attitudes about HIV/AIDS, perception of risk, and appropriate concern about contracting AIDS. Most importantly, adolescents in the ARREST group demonstrated a significant increase in behavioral skills for negotiating prevention and risk reduction, and resisting peer pressures to engage in risk-related sexual and drug-use behaviors.

CONCLUSIONS

ARREST was effective in meeting its short-term objectives for changes in knowledge and behavioral skills, which are important prerequisites for behavior change. Replication with long-term follow-up assessment is needed, however, to determine this intervention's effectiveness at changing risk-related sexual and drug-use behaviors.

The evaluation of targeted outreach in an adolescent HIV/AIDS program

PURPOSE

Most HIV infected youth are unaware of their serostatus. Among adolescents who know they are HIV positive, only a small percentage are currently receiving care in age-specific programs. Establishing effective links between prevention and service programs is critical in reaching this group of young people.

METHODS

A specific outreach strategy was designed to develop more referrals from a wider variety of agencies to better serve youth at risk for HIV. A needs assessment of community-based agencies was the basis for: 1. overcoming barriers to care, 2. specifying the target population, 3. assessing existing referrals, and 4. selecting agencies for different levels of intensity of outreach.

RESULTS

Six barriers faced by potential referring agencies were identified and corresponding solutions created which were incorporated into the outreach strategy. A comparison was made of referrals in the years before, during and after the outreach strategy was instituted. A significant difference by (chi 2 analysis) was noted in the number of agencies (p < 0.05), number of individuals (p < 0.01), number of appointments kept (p < 0.01), and the number of HIV+ youth enrolled (p < 0.01) during the year when the plan was fully implemented compared to previous and subsequent years.

CONCLUSIONS

Systematic targeted outreach programs are an efficient way to maximize the time and effort of outreach staff. The result was an increase in the number and diversifity of referrals. This strategy could be used by groups caring for adults or younger children who want to expand services to include adolescents or by groups providing HIV/AIDS care who want to specifically serve adolescents.

Human immunodeficiency virus-infected adolescents: the first 50 patients in a New York City program

To address the unique manifestations of human immunodeficiency virus (HIV) among adolescents aged 13 through 21 years, a comprehensive evaluation and treatment program for high-risk and HIV-positive adolescents was developed in New York City in 1987. Among HIV-infected youth, mean age of testing was 18.2 years. One third of the HIV-positive patients were female and four fifths were African-American or Hispanic. No significant differences were found between HIV-positive (n = 50) and HIV-negative (n = 43) patients for age at first intercourse, injecting or other illicit drug use, history of sexually transmitted diseases, or survival sex (exchange of sex for money or drugs). HIV-positive males were more likely than HIV-negative males to have engaged in anal intercourse and to report a history of sexual abuse. Among infected females, 82% acquired HIV through heterosexual intercourse. Almost half (48%) of HIV-positive adolescents had significant immune dysfunction at the time of their initial visit (CD4 < 500/mm3) and were eligible for zidovudine. Many HIV-positive adolescents continued high-risk behaviors such as intercourse without condoms, particularly those with ongoing dependence on drugs or alcohol. With the epidemic of HIV infection increasing nationwide among adolescents, specialized, comprehensive programs are needed to counsel and treat HIV-infected adolescents and youth in high-risk situations.

Theophylline disposition in adolescents with asthma

Adolescents frequently require medication for acute and chronic illnesses. A proper dosage schedule is needed to achieve efficacy without toxicity during adolescence when there are marked changes in body size and organ function. Theophylline disposition was studied in 70 asthmatic adolescents, ages 8-18 years, to determine if pubertal changes in body size, composition, and organ function are associated with changes in drug disposition. Forty-eight youngsters were studied as outpatients and 22 while hospitalized. Half-life (t1/2) was computed for all patients. Volume of distribution and clearance were determined for inpatients only. Chronological age and anthropometric growth parameters were measured. Lean body mass (LBM) was derived from anthropometric measurements. Half-life was significantly correlated with developmental stage (Tanner r = 0.42, age r = 0.33, p less than 0.01), and body size (height r = 0.39, LBM r = 0.33, weight r = 0.33, p less than 0.01). LBM (kg/kg) was significantly correlated with volume of distribution (L/kg) (r = 0.59, p less than 0.01). Best-fits for t1/2 contained two variables: t1/2 = -4.57 + 1.31 (sex) + 0.0687 (height) (r = 0.48) and t1/2 = -3.54 + 1.32 (sex) + 0.0725 (LBM) (r = 0.43). Chronological age alone is not a useful basis for determining medication dosages due to the heterogeneity in rates of development and body size among adolescents. Half-life increases with increasing height or LBM. Although compliance is clearly an important factor in achieving optimal control of symptoms, this study demonstrates that dose adjustment during times of rapid growth during puberty is equally important.

HIV infection and AIDS during adolescence

It is clear from the evidence that a growing number of adolescents are acquiring HIV infection and developing AIDS. The impact this epidemic will have on all teenagers is overwhelming. Given the high prevalence of risk-related sexual behaviors, many adolescents are likely to become HIV infected, thus requiring extensive medical and psychosocial services. Other adolescents will lose a parent, relative, or friend to AIDS, and these adolescents will similarly require special services and psychological counseling. Thus, there is an immediate need for the development of methods for (1) providing all adolescents with age-appropriate and culturally relevant interventions for prevention and risk reduction, (2) identifying high-risk adolescents and triaging them to different levels of care and risk reduction counseling, and (3) providing ongoing medical and psychosocial treatments. Accessing adolescents at risk for HIV infection will require networking between the health care system and youth-serving and community-based agencies, particularly agencies servicing high-risk adolescents. We must begin addressing these needs now, in order to prevent further infection and to provide appropriate care for those adolescents who are or will become infected with HIV.

Model for the kinetics of imipramine and its metabolites in adolescents

A kinetic model for imipramine (IMI) has been developed, based upon a study of 16 teenagers who received IMI 4-5 mg/kg/day for treatment of a major depressive disorder. Serial measurements of plasma concentrations of IMI, desmethylimipramine (DMI), 2-hydroxy-IMI, and 2-hydroxy-DMI were made. Mean residence times, volumes of distribution, clearances of IMI and DMI, and rate constants for formation and elimination of the hydroxy metabolites were determined from a multicompartment model fitted to the concentration-time data. Mean residence time for DMI was significantly longer than for IMI (47.1 +/- 21.2 vs. 13.4 +/- 4.8 h, p less than 0.001). A different volume of distribution for IMI and DMI was not supported by the data. Clearance of DMI was considerably slower than that of IMI (0.67 +/- 0.45 vs. 2.18 +/- 1.33 l(kg.h), p less than 0.001). A statistically significant increase in mean residence time with increasing age during adolescence was found (r = 0.57, p less than 0.05).

Acquired immunodeficiency syndrome among adolescents. Case surveillance profiles in New York City and the rest of the United States

Adolescents engaging in certain sexual or drug-related behavior are at risk of contracting the human immunodeficiency virus infection in endemic locales. Local and national surveillance data were analyzed to determine the characteristics of the acquired immunodeficiency syndrome (AIDS) epidemic on adolescents. Of the 605 cases of AIDS in people aged 13 to 21 years reported through 1987, 518 were males (83 from New York City [NYC], NY), and 87 were females (28 from NYC). Over half of all adolescent males with AIDS reported homosexual contact. Transfusion/blood product-related human immunodeficiency virus acquisitions (especially in males with hemophilia) represented 11% of adolescent cases from NYC (1% of NYC adults) and 22% of adolescent cases in the United States (US) outside of NYC (4% of adults in the US). Intravenous drug use was more frequently reported among adolescents with AIDS from NYC (23%) than among adolescents outside NYC (14%). In females, heterosexual transmission accounts for about half of all adolescent AIDS cases and 29% of all adult cases. Age-appropriate services and behavioral interventions are urgently needed for high-risk adolescents.

Pulmonary contusion: CT vs plain radiograms

In experimentally induced pulmonary contusions, CT (n = 27) and chest X-ray (n = 24) findings were compared with the findings at autopsy. Twenty-seven of 27 (100%) pulmonary contusions were visible by CT immediately after trauma compared with 9 of 24 (37.5%) in the chest X-ray. After 30 min follow-up, 18 of 24 (75%) lesions were seen on the plain film. Five of 24 (21%) contusions escaped detection on conventional radiographs. Computed tomography underestimated lesion size in 5 of 60 (8%) measurements, conventional radiographs in 21 of 36 (58%) measurements. Pathological examination never revealed a pulmonary contusion that was not demonstrated by CT. Therefore, pulmonary contusion seems unlikely in a trauma patient with normal pulmonary CT.