Maternal Perspective of Inpatient Methadone Initiation: Opportunities to Increase Retention in Treatment

OBJECTIVES

Recent trends demonstrate increases in the rates of opioid use among pregnant and parenting women. Treatment for pregnant people with opioid use disorder (OUD) includes medications for OUD, like methadone, as well as comprehensive support services. Still, inpatient treatment engagement is suboptimal and treatment drop out is common. There is little research examining the maternal perspective of the inpatient methadone initiation experience. The primary aim of this qualitative methods study was to explore patient experience and perspective of the inpatient methadone initiation period.

METHODS

All participants were recruited from a single urban university affiliated hospital and OUD treatment program. Data were collected from 30 maternal participants in OUD treatment about their inpatient methadone initiation experience while pregnant using semistructured interviews. Thematic analyses were conducted using an inductive approach after an iterative process of code development and application among a multidisciplinary team of 3 coders. Validity was accounted for through 2 participant feedback interviews and study team review and discussion of findings.

RESULTS

Four themes emerged from the maternal interview data: (1) Barriers to Inpatient Methadone Initiation, (2) Facilitators to Inpatient Methadone Initiation, (3) Transition From Hospital Inpatient to Outpatient or Residential OUD Treatment Services, and (4) Opportunities for Enhanced Clinical Support.

CONCLUSION

Maternal participants reported multiple barriers and facilitators to inpatient care during methadone initiation, highlighting opportunities for improvement to effectively engage pregnant individuals in treatment.

Racial/Ethnic Disparities in Mental Healthcare in Youth With Incarcerated Parents

INTRODUCTION

Youth with incarcerated parents experience more adverse childhood experiences than other youth, placing them at higher risk for mental health and substance use disorders. Despite their increased risk, these youth may be less likely to access mental health services, particularly given their racial and ethnic makeup. Therefore, this study aimed to assess racial and ethnic disparities in access to mental health services for youth with incarcerated parents.

METHODS

This secondary data analysis used longitudinal data from 2016 to 2019 from the Adolescent Brain Cognitive Development Study. Logistic regression models assessed the relationships among incarceration, cumulative childhood experiences, DSM-5 diagnoses, and mental health services. Additional analyses stratified these models by race and ethnicity. All analyses were performed in 2022.

RESULTS

Youth with incarcerated parents were more likely to report 4 or more childhood experiences (51% vs 14%; AOR=3.92; 95% CI=3.3, 4.65; p<0.001) and to have received mental health services (25% vs 15%; AOR=1.89; 95% CI=1.6, 2.21; p<0.001) than unexposed youth. However, Black youth with incarcerated parents (19% vs 34%; AOR=0.38; 95% CI=0.27, 0.52; p<0.001) and Latinx youth with incarcerated parents (10% vs 17%; AOR=0.5; 95% CI=0.33, 0.76; p<0.001) were significantly less likely to report receiving mental health services than White youth with incarcerated parents and non-Latinx youth with incarcerated parents, respectively.

CONCLUSIONS

Youth with incarcerated parents were more likely to report utilization of mental health services, but significant racial and ethnic disparities exist between Black and Latinx youth with incarcerated parents compared with that among White and non-Latinx youth with incarcerated parents. There is a continued need to expand mental health services to youth with incarcerated parents and to address racial and ethnic disparities in access to care.

Youth Trauma Histories are Associated with Under-diagnosis and Under-treatment of Co-occurring Youth Psychiatric Symptoms

OBJECTIVE

We examined whether in the presence of trauma exposure, non-traumatic stress-related symptoms are interpreted by mental health clinicians as less salient than the trauma exposure and are de-emphasized as a treatment target, consistent with a diagnostic overshadowing bias.

METHODS

Using an adapted version of a diagnostic overshadowing bias experimental paradigm, mental health clinicians (N = 266, M age = 34.4 years, 82% female) were randomly assigned to receive two of six clinical vignette variations. Vignette 1 described an adolescent with obsessive-compulsive disorder (OCD). Vignette 2 described a pre-adolescent with oppositional defiant disorder (ODD). Vignettes were identical except for whether the youth reported exposure to a potentially traumatic event (PTE; no PTE, sexual PTE, or physical PTE). Clinicians received one vignette with a PTE and one without, counterbalancing order. Clinicians rated the likelihood the youth met criteria for various diagnoses and the appropriateness of various treatments on 7-point scales.

RESULTS

Across both vignettes, clinicians rated the target diagnosis (OCD in Vignette 1, ODD in Vignette 2) as less likely for vignettes with a PTE than for the same vignettes without a PTE. Clinicians also rated evidence-based treatment modalities for target diagnoses as less appropriate in the presence of a PTE than when a PTE was present.

CONCLUSIONS

Consistent with possible bias, clinicians may under-recognize and under-treat non-traumatic stress-related mental health symptoms in youth with a co-occurring trauma history. Future work to validate this bias in real-world practice is indicated.

Implementation and Outcomes of the Trauma Ambassadors Program: A Case Study of Trauma-Informed Youth Leadership Development

Community-based programs serve a critical need for vulnerable youth and families. In recent years, researchers and practitioners have urged programs to adopt a trauma-informed care (TIC) approach to address adversity in young people's lives. The purpose of this article is to describe the implementation and outcomes of the Trauma Ambassador (TA) Program, a pilot youth leadership program guided by a community-university partnership that utilized a TIC approach in an underserved East North Philadelphia neighborhood. Fourteen youth engaged in interactive trainings to build their understanding of trauma and develop practical tools to support encounters with individuals with trauma histories. Focus groups and individual interviews were conducted to better understand program implementation and outcomes. Rich data emerged that identifies a myriad of ways that youth and their community might benefit from a program like the one described. The program successfully impacted participants, as TAs recognized their own trauma and were motivated to help others who may have trauma histories. This program provided quality youth development experiences, particularly with respect to trauma-informed care, and results support taking a holistic, healing-centered approach to foster well-being for youth and adult mentors.

Predictors of Clinician-Reported Self-Efficacy in Treating Trauma-Exposed Youth

Clinicians' self-efficacy with regard to delivering evidence-based interventions (EBIs) to youth is an important target for both improving EBI use in the community and mitigating the risk of clinician burnout and turnover. Examining predictors of clinician self-efficacy to treat trauma-exposed youth is, therefore, an important step for informing the design of implementation strategies to enhance the mental health workforce's capacity to deliver EBIs in this population. We examined predictors of clinician self-efficacy in working with trauma-exposed youth in a sample of practicing mental health clinicians (N = 258, M age = 34.4 years, 85.0% female). Clinicians were recruited and surveyed as part of a larger study examining how clients' exposure to potentially traumatic events influences clinician decision-making. Results of regression models indicated that training in any trauma treatment model, being trained via a variety of formats (e.g., in-person training, online, supervision), and training in a variety of treatment models were all associated with higher perceived self-efficacy regarding effectively treating trauma-exposed youth. Of the treatment models and training formats examined, receiving in-person training, R2 = .10, and training in trauma-focused cognitive behavioral therapy, R2 = .10, were the strongest predictors of higher self-efficacy ratings. Clinician discipline, R2 = .04, and clinical practice factors, R2 = .20, were also related to self-efficacy. Collectively, the R2 indicated a large effect, with the predictors explaining 25.4% of the variance in self-efficacy ratings. Implications for designing implementation strategies targeting clinician self-efficacy and future research are discussed.

Change Across Time in Cancer-Related Traumatic Stress Symptoms of Siblings of Children with Cancer: A Preliminary Investigation

This pilot study examined changes in cancer-related post-traumatic stress symptoms (PTSS) across time for siblings of children with cancer. Siblings (N = 32; aged 8-18) completed a measure of anxiety, the Child PTSD Symptom Scale (CPSS), and the PTSD section of the Structured Clinical Interview for DSM-IV-TR (SCID) at twelve (SD = .9) and eighteen months (SD = 1.3) post-diagnosis. Moderate-to-severe PTSS was reported by 12 siblings (38%) at T1 and 7 (22%) at T2. Cluster analysis of PTSS data revealed five patterns: Few symptoms, stable across time (31%, n = 10); Mild symptoms, decreasing across time (16%, n = 5); Mild, stable symptoms (28%, n = 9); Moderate/severe symptoms, decreasing across time but remaining moderate (19%, n = 6); and Moderate/severe, stable symptoms (6%, n = 2). SCID data and anxiety scores distinguished siblings in the final two clusters from those with more favorable PTSS levels/trajectories. Additional research with larger samples is needed to validate these trajectories and examine factors that distinguish siblings with consistently elevated cancer-related PTSS from those with mild or significantly improving symptoms.

Caught off guard by covid-19: Now what?

Human beings are social in nature and maintaining social interactions, relationships and intimacy are fundamental needs of older adults (OAs) living in assisted living (AL) communities. Yet, these very basic human needs have been impeded by quarantine mandates imposed by the COVID-19 pandemic. The socialization aspect offered in AL, allows for an integration of the whole person: body, mind, and spirit and is beneficial in mitigating the development of co-morbidities and negative patient outcomes. Additionally, the authenticity of home comes from the caring interactions provided by an interprofessional health care staff. Utilizing the 4 M Framework, created by The John A. Hartford Foundation and Institute of Healthcare Improvement, the authors describe simple direct bedside interventions of low cost, and high patient-centered value which front-line nursing and caregiver staff can employ to maintain social connections, interactions, mentation, function and mobility among residents they care for, and care about, in AL communities.

Psychosocial Assessment as a Standard of Care in Pediatric Cancer

This paper presents the evidence for a standard of care for psychosocial assessment in pediatric cancer. An interdisciplinary group of investigators utilized EBSCO, PubMed, PsycINFO, Ovid, and Google Scholar search databases, focusing on five areas: youth/family psychosocial adjustment, family resources, family/social support, previous history/premorbid functioning, and family structure/function. Descriptive quantitative studies, systematic reviews, and meta-analyses (n = 149) were reviewed and evaluated using grading of recommendations, assessment development, and evaluation (GRADE) criteria. There is high quality evidence to support a strong recommendation for multifaceted, systematic assessments of psychosocial health care needs of youth with cancer and their families as a standard of care in pediatric oncology.

Biological abnormalities of peripheral A2A receptors in a large representation of polyglutamine disorders and Huntington's disease stages

Huntington's disease is one of a group of hereditary neurodegenerative diseases characterized by a glutamine expansion (polyQ) in proteins which are expressed in various cell populations. In agreement with this widespread distribution, we have previously shown that A(2A) receptor signaling is affected in mouse brain as well as in peripheral blood cells from a small cohort of HD patients. Here we analyzed a total of 252 subjects, including 126 HD gene-positive individuals, from different clinical sites. Consistent with our previous data we show that A(2A) receptor B(max) values are robustly increased at all HD stages as well as in 32 pre-symptomatic subjects. We report that the same abnormality is present also in other polyQ but not in non-polyQ inherited neurological disorders. Finally, we demonstrate that the same peripheral cells exhibit an altered membrane fluidity, a finding that may explain the observed change in receptor density. We argue that the observed alteration in lymphocytes reflects the presence of the mutant protein, and we suggest that the measure of the A(2A) receptor binding activity might be of potential interest for a peripheral assessment of chemicals capable of interfering with the immediate toxic effects of the mutation.

Errors in Huntington disease diagnostic test caused by trinucleotide deletion in the IT15 gene

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Deletion mapping of gliomas suggest the presence of two small regions for candidate tumor-suppressor genes in a 17-cM interval on chromosome 10q

The loss of genetic material on chromosome 10q is frequent in different tumors and particularly in malignant gliomas. We analyzed 90 of these tumors and found loss of heterozygosity (LOH) in >90% of the informative loci in glioblastoma multiforme (GBM). Initial studies restricted the common LOH region to 10q24-qter. Subsequently, the study of a pediatric GBM suggested D10S221 and D10S209, respectively, as centromeric and telomeric markers of a 4-cM LOH region. It is interesting to note that, in one subset of cells from this tumor, locus D10S209 seems involved in the allelic imbalance of a larger region, with D10S214 as telomeric marker. This 17-cM region contains the D10S587-D10S216 interval of common deletion recently defined on another set of gliomas.

Nuclear DNA origin of cytochrome c oxidase deficiency in Leigh's syndrome: genetic evidence based on patient's-derived rho degrees transformants

Defects of the respiratory chain carrying out oxidative phosphorylation (OXPHOS) are the biochemical hallmark of human mitochondrial disorders. Faulty OXPHOS can be due to mutations in either nuclear or mitochondrial genes, that are involved in the synthesis of individual respiratory subunits or in their post-translational control. The most common mitochondrial disorder of infancy and childhood is Leigh's syndrome, a severe encephalopathy, often associated with a defect of cytochrome c oxidase (COX). In order to demonstrate which genome is primarily involved in COX-deficient (COX(-))-Leigh's syndrome, we generated two lines of transmitochondrial cybrids. The first was obtained by fusing nuclear DNA-less cytoplasts derived from normal fibroblasts, with mitochondrial DNA-less (rho degree) transformant fibroblasts derived from a patient with COX(-))-Leigh's syndrome. The second cybrid line was obtained by fusing rho degree cells derived from 143B.TK- human osteosarcoma cells, with cytoplasts derived from the same patient. The first cybrid line showed a specific and severe COX(-) phenotype, while in the second all the respiratory chain complexes, including COX, were normal. These results indicate that the COX defect in our patient is due to a mutation of a nuclear gene. The use of cybrids obtained from 'customized', patient-derived rho degree cells can have wide applications in the identification of respiratory chain defects originated by nuclear DNA-encoded mutations, and in the study of nuclear DNA-mitochondrial DNA interactions.

Early-onset encephalomyopathy associated with tissue-specific mitochondrial DNA depletion: a morphological, biochemical and molecular-genetic study

A male infant, born from consanguineous parents, suffered from birth with a progressive neuromuscular disorder characterized by psychomotor delay, hypotonia, muscle weakness and wasting, deep-tendon areflexia and spastic posture. High levels of lactic acid in blood and cerebrospinal fluid suggested a mitochondrial respiratory chain defect. Muscle biopsy revealed ragged-red and cytochrome c oxidase-negative fibres, lipid accumulation and dystrophic changes. Multiple defects of respiratory complexes were detected in muscle homogenate, but cultured fibroblasts, myoblasts and myotubes were normal. Southern blot analysis showed markedly reduced levels of mitochondrial DNA (mtDNA) in muscle, while lymphocytes, fibroblasts and muscle precursor cells were normal. Neither depletion of mtDNA nor abnormalities of the respiratory complexes were observed in innervated muscle fibres cultured for as long as 4 months. No mutations were observed in two candidate nuclear genes, mtTFA and mtSSB, retro-transcribed, amplified and sequenced from the proband's mRNA. Sequence analysis of the mtDNA D-loop and of the origin of replication of the mtDNA light strand failed to identify potentially pathogenic mutations of these replicative elements in the proband's muscle mtDNA. Our findings indicate that mtDNA depletion is due to a nuclear encoded gene and suggest that the abnormality underlying defective mtDNA propagation must occur after muscle differentiation in vivo.

Sequence analysis of mitochondrial DNA in a new maternally inherited encephalomyopathy

A heteroplasmic insertion of a 9-bp tandem repeat element was detected in the mitochondrial DNA of the maternal members of a large family. The mutation was contained within the non-coding region between the genes specifying subunit II of cytochrome c oxidase and tR-NA(Lys). The proband and most of his maternal relatives were affected by a late-onset mitochondrial encephalomyopathy of variable severity, characterized by a unique combination of symptoms. Extensive screening of a large series of DNA samples, collected from unrelated normal individuals as well as patients affected by different neurological disorders, consistently failed to detect the 9-bp insertion, with two exceptions: a patient suffering from a syndrome virtually identical to that described in our original family and a child affected by bilateral striatal necrosis, a disorder which has been attributed to impairment of mitochondrial oxidative phosphorylation. These considerations suggest that the 9-bp insertion is pathogenic and that the region affected by the mutation may play a previously unsuspected functional role in mtDNA gene expression.

Redefinition of the coding sequence of the MXI1 gene and identification of a polymorphic repeat in the 3' non-coding region that allows the detection of loss of heterozygosity of chromosome 10q25 in glioblastomas

The MXI1 gene encodes a protein interacting with Max, a regulatory factor of the Myc oncogene, and is located on chromosome 10q25, a region showing frequent loss of heterozygosity in malignant gliomas. We have reassessed the coding sequence of MXI1 and found that, at the 3' end, the open reading frame is 28 codons shorter than previously described. We have also found an AAAAC polymorphic repeat (two alleles, 45% heterozygosity) in the 3' non-coding region of the gene. Six anaplastic astrocytomas and nine glioblastomas, the most malignant form of glioma, were informative for this polymorphism. Loss of heterozygosity was demonstrated in all glioblastomas, but not in the remaining tumors.

Genotype to phenotype correlations in mitochondrial encephalomyopathies associated with the A3243G mutation of mitochondrial DNA

We studied 22 subjects carrying the A3243G point mutation of human mitochondrial DNA (mtDNA). In 14 cases the clinical phenotype was characterized by mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), while 8 patients had chronic progressive external ophthalmoplegia (CPEO). The proportion of A3243G heteroplasmy in muscle was determined by two methods; densitometry on a diagnostic restriction-fragment length polymorphism and solid-phase mini-sequencing. We found a highly significant inverse correlation between the percentage of A3243G mutation and the specific activity of complex I, the respiratory complex with the highest number of mtDNA-encoded subunits, suggesting a direct effect of the mutation on mtDNA translation. No correlation was observed between the percentage of mutated mtDNA and the presence or absence of specific clinical features, such as stroke, ophthalmoplegia and diabetes mellitus. However, in the MELAS group the percentage of mutated mtDNA molecules was strongly correlated with the age of onset, while no such correlation was found in the CPEO group, suggesting a different time-dependent evolution of the mutation in the two groups. Finally, in contrast with other mtDNA mutations associated with ragged-red fibres (RRF), in both MELAS3243 and CPEO3243 we observed a high proportion of RRF that were positive to the histochemical reaction to cytochrome c oxidase, a morphological feature that seems to be specific for the neuromuscular phenotypes associated with mutations affecting the tRNA(Leu(UUR)) gene.

Chromosomal localization of mitochondrial transcription factor A (TCF6), single-stranded DNA-binding protein (SSBP), and endonuclease G (ENDOG), three human housekeeping genes involved in mitochondrial biogenesis

By using a PCR-based screening of a somatic cell hybrid panel and FISH, we have assigned the loci of mitochondrial single-stranded DNA-binding protein (SSBP), mitochondrial transcription factor A (TCF6), and mitochondrial endonuclease G (ENDOG) genes to human chromosomes 7q34, 10q21, and 9q34.1, respectively. The products of these three genes are involved in fundamental aspects of mitochondrial biogenesis, such as replication and transcription of the mitochondrial genome. The chromosomal localization of these genes is important to testing whether the corresponding proteins may play a role in the etiopathogenesis of human disorders associated with qualitative or quantitative abnormalities of mitochondrial DNA.

Evidence of linkage between susceptibility to multiple sclerosis and HLA-class II loci in Italian multiplex families

To verify whether multiallelic polymorphisms belonging to HLA class II genes are linked to multiple sclerosis (MS) in the Italian population, we studied 28 multiplex MS families originating from different areas of Italy. Allelic characterization was carried out by analysis of RFLPs and oligonucleotide typing. Evidence supporting the existence of linkage between MS susceptibility and the HLA class II loci DRB1, DQA1 and DQB1 was provided using two non-parametric tests, affected sib-pair analysis, and affected-pedigree-member (APM) analysis. The APM analysis also suggested the existence of genetic heterogeneity for the HLA class II loci and MS susceptibility in our series. Linkage disequilibrium between MS susceptibility and the haplotype DRB1*1501,DQA1*0102,DQB1*0602 was demonstrated by applying the transmission linkage disequilibrium test to our families. Finally, lod score analysis suggests that in our Italian families, MS susceptibility is conferred by HLA class II alleles according to a low-penetrance autosomal recessive mode of inheritance.

Carnitine palmitoyltransferase II deficiency: structure of the gene and characterization of two novel disease-causing mutations

Carnitine palmitoyltransferase (CPT) II deficiency is the most common inherited disorder of lipid metabolism affecting skeletal muscle. To facilitate the identification of disease-causing mutations in the CPT II gene (CPT1), we have established the genomic organization of this gene. CPT1 spans approximately 20 kb of 1p32 and is composed of five exons ranging from 81 to 1305 bp. The sequences of the exon--intron boundaries were determined for each exon and conformed to the consensus splice junction sequences. The 5' and 3' untranslated regions in exon 1 and 5, respectively, were also determined, including the polyadenylation signal and the polyadenylation site. The mature transcript is predicted to be 3090 nt in length. CPT1 exons from CPT II-deficient patients were amplified and directly sequenced. Two novel disease-causing mutations were identified and characterized. The first mutation was a C-665-to-A transversion in exon 1 resulting in a proline-to-histidine substitution at residue 50 of the protein (P50H). This amino acid substitution occurs within a leucine-proline motif that is highly conserved in acyltransferases from different species. The mutation was detected in both alleles of patient 05SB of Italian ancestry, and in one allele of patients 11EG, 38PG, and 26FD of Italian, Dutch, and French ancestry, respectively. The second mutation was a rare G-2173-to-A transition in exon 5 causing an aspartic-acid-to-asparagine substitution at amino acid 553 (D553N) and the generation of a new MseI site. The mutation was detected only in one allele of patient 15MB, of Italian ancestry, who was also heterozygous for the common S113L substitution. Transfection experiments in COS cells demonstrated that both mutations drastically depressed the catalytic activity of CPT II. Biochemical characterization of P50H mutant CPT II in cultured cells from patient 05SB showed that the mutation does not affect substrate binding sites. Finally, immunoblot analysis demonstrated that both mutations were associated with markedly reduced steady-state level of the protein, thus indicating decreased stability of the mutant CPT II.

Late-onset riboflavin-responsive myopathy with combined multiple acyl coenzyme A dehydrogenase and respiratory chain deficiency

We studied the effect of riboflavin treatment on the clinical status and on the activities of beta-oxidation and respiratory chain enzymes in a 69-year-old patient with late-onset myopathy. Before treatment, she was very weak and wasted in the limbs and trunk muscles; also, she could not walk or attend to daily activities. Marked lipid storage was present in the muscle biopsy. The activities of short-chain acyl coenzyme A (acyl-CoA) dehydrogenase (SCAD), medium-chain acyl-CoA dehydrogenase (MCAD), and long-chain acyl-CoA dehydrogenase (LCAD) in isolated muscle mitochondria were reduced to less than 10% of control values. This defect in fatty acid oxidation was associated with a marked deficiency of two flavin-dependent respiratory chain complexes: complex I activity was 20% and complex II activity was 25% of control values. By contrast, the activities of the nonflavin-dependent complex III and complex IV were normal. Western blot analysis of the patient's muscle mitochondrial extracts with antibodies raised against purified SCAD, MCAD, and the alpha- and beta-subunits of the electron transfer flavoprotein (ETF) showed absence of SCAD cross-reacting material (CRM), markedly decreased MCAD-CRM, and normal amounts of both alpha- and beta-ETF-CRM. After riboflavin treatment, the patient's clinical status dramatically improved and morphologic changes in muscle disappeared. SCAD activity increased to 55% of control values, whereas MCAD, LCAD, and complex I and complex II activities normalized. SCAD and MCAD immunoreactivity was restored to normal. On the basis of our experience and the data in the literature, we concluded that some lipid storage myopathies can show dramatic response to riboflavin.

Divergent sequences in the 5' region of cDNA suggest alternative splicing as a mechanism for the generation of carnitine acetyltransferases with different subcellular localizations

We identified two partially overlapping cDNAs containing divergent 5' sequences of human carnitine acetyltransferase (CAT). cDNA lambda SM-1400 extends the sequence of peroxisomal CAT, whereas cDNA lambda SM-1200 creates a new open reading frame encoding a putative mitochondrial leader peptide. An intron is located where sequences diverge, suggesting that mitochondrial, peroxisomal and possibly endoplasmic reticulum CAT mRNAs derive from alternative splicing of the CAT gene.

Identification of 5' regulatory regions of the human carnitine palmitoyltransferase II gene

We have identified two partially overlapping genomic clones that contain part of the 5' regulatory region of the human carnitine palmitoyltransferase II gene. The 1.2 kb region upstream the transcription start site, as defined by primer extension experiments, shows promoter activity when inserted upstream of a reporter gene and contains a putative insulin responsive element.

Molecular cloning of cDNAs encoding human carnitine acetyltransferase and mapping of the corresponding gene to chromosome 9q34.1

Using a combination of PCR screening of cDNA libraries and reverse transcription PCR, we have cloned three overlapping DNA fragments that encode human carnitine acetyltransferase (CAT), a key enzyme for metabolic pathways involved with the control of the acyl-CoA/CoA ratio in mitochondria, peroxisomes, and endoplasmic reticulum. The resulting cDNA (2436 bp) hybridizes to a mRNA species of approximately 2.9 kb that is particularly abundant in skeletal muscle and encodes a 68-kDa protein containing a peroxisomal targeting signal. The sequence matches those of several tryptic peptides obtained from purified human liver CAT and shows striking similarities with other members of the carnitine/choline acetyltransferase family very distant throughout evolution. CAT cDNA has also been used for fluorescence in situ hybridization on metaphase spreads of human chromosomes, and the corresponding gene, CAT1, has been mapped to chromosome 9q34.1.

Increasing complexity of the karyotype in 50 human gliomas. Progressive evolution and de novo occurrence of cytogenetic alterations

We studied the karyotypes of eight differentiated gliomas, 19 anaplastic gliomas, and 23 glioblastomas (GBM). Normal stemlines were present in 70% of the differentiated and anaplastic gliomas; abnormalities were mostly characterized by loss of sex chromosomes. In GBM, on the contrary, only 13% of the stemlines were normal and three groups, 45,XO, near-diploid, and near tetraploid, could be identified. The most frequent alterations among GBM were: total or partial loss of chromosome 10 in nine cases, structural abnormalities of chromosome 9 in seven cases, and loss of the Y chromosome in stemline clones of seven cases. Less frequent abnormalities included chromosomes 7, 1, 3, and 19. Our data support the cytogenetic model of gliomas as multi-stage tumors. GBM, in particular, can originate from the evolution of astrocytomas but can also develop de novo. In both cases loss of genetic material on chromosome 10 seems to play a crucial role.

Defective respiratory capacity and mitochondrial protein synthesis in transformant cybrids harboring the tRNA(Leu(UUR)) mutation associated with maternally inherited myopathy and cardiomyopathy

We studied the physiometabolic effects of a mitochondrial DNA (mtDNA) heteroplasmic point mutation, the A-->G3260 transition associated with maternally inherited myopathy and cardiomyopathy. To eliminate the possible influence of the autochthonous nuclear gene set, we fused myoblast-derived cytoplasts of a patient with a human tumoral cell line deprived of mtDNA (Rho degrees). The presence and amount of the mutant G3260 vs the wild-type A3260 were measured by solid phase minisequencing. We observed a marked reduction of the percentage of mutant mtDNA in the culture system compared with that measured in the donor's muscle biopsy, suggesting the presence of negative selection against the mutation. Furthermore, stable mitotic segregation of the two mtDNA populations was observed in 18 of 19 transformant clones, suggesting the presence of intraorganelle and possibly intracellular homoplasmy in the precursor cells of the donor. Several indexes of mtDNA-related respiratory capacity, including oxygen consumption, complex I- and complex IV-specific activities, and lactate production, were markedly abnormal in the clones containing a high proportion of mutant mtDNA, as compared with those containing homoplasmic wild-type mtDNA, possibly because of impaired mitochondrial protein synthesis. We conclude that (a) the A-->G3260 transition is indeed responsible for the mitochondrial disorder identified in the donor patient, and (b) transformant cybrid system gives direct evidence of the mitochondrial origin of a genetic disorder and should be adopted for the evaluation of the pathogenic potential of the mtDNA mutations.

Mutations and polymorphisms of the gene encoding the beta-subunit of the electron transfer flavoprotein in three patients with glutaric acidemia type II

Electron transfer flavoprotein (ETF) is a heterodimeric enzyme composed of an alpha-subunit and a beta-subunit and contains a single equivalent of FAD per dimer. ETF deficiency can be demonstrated in individuals affected by a severe metabolic disorder, glutaric acidemia type II (GAII). In this study, we have investigated for the first time the molecular basis of beta-ETF deficiency in three GAII patients: two Japanese brothers, P411 and P412, and a third unrelated patient, P485. Molecular analysis of the beta-ETF gene in P411 and P412 demonstrated that both these patients are compound heterozygotes. One allele is carrying a G to A transition at nucleotide 518, causing a missense mutation at codon 164. This point mutation is maternally derived and is not detected in 42 unrelated controls. The other allele carries a G to C transversion at the first nucleotide of the intron donor site, downstream of an exon that is skipped during the splicing event. The sequence analysis of the beta-ETF coding sequence in P485 showed only a C to T transition at nucleotide 488 that causes a Thr154 to Met substitution and the elimination of a HgaI restriction site. HgaI restriction analysis on 63 unrelated controls' genomic DNA demonstrated that the C488T transition identifies a polymorphic site. Finally, transfection of wild-type beta-ETF cDNA into P411 fibroblasts suggests that wild-type beta-ETF cDNA complements the genetic defect and restores the beta-oxidation flux to normal levels.

Respiratory chain and mitochondrial DNA in muscle and brain in Parkinson's disease patients

There are several reports of a defect of complex I in the substantia nigra (SN) of Parkinson's disease (PD) patients. To evaluate whether this is specific to dopaminergic neurons or the phenotypically relevant consequence of a widespread failure of the mitochondrial oxidative phosphorylation (OXPHOS) system, we measured respiratory enzyme activities in muscle homogenates from 16 PD patients and eight age-matched controls, and in muscle isolated mitochondria of six PD patients and six age-matched controls. We found no difference between the PD and control groups. In addition, we detected, by polymerase chain reaction, the mitochondrial DNA (mtDNA) "common deletion" (CD) in muscle specimens of 14 of 17 PD patients, but we obtained similar results in age-matched controls. In both groups, the amount of CD-specific deleted (delta) mtDNA ranged from 0.0% to 0.1%. Our data suggest that PD cannot be attributed to a multisystem decline of mitochondrial OXPHOS, and that lesions of muscle mtDNA in PD are likely due to normal aging. However, there was a remarkable accumulation of delta mtDNA in the SN of a PD patient and an age-matched control, suggesting that the SN is exquisitely sensitive to age-dependent damage of the mitochondrial genome.

Identification of a common mutation in the carnitine palmitoyltransferase II gene in familial recurrent myoglobinuria patients

Carnitine palmitoyltransferase (CPT) II deficiency is the most common inherited disorder of lipid metabolism affecting skeletal muscle. We have identified a missense mutation (Ser113Leu) in one patient with the classical muscular symptomatology. Transfection experiments in COS cells demonstrate that the mutation drastically depresses the catalytic activity of CPT II. The mutation results in normal synthesis but a markedly reduced steady-state level of the protein, indicating decreased stability of mutant CPT II. The Ser113Leu mutation is the most frequent cause of CPT II deficiency. The mutation can be detected easily by restriction analysis enabling molecular diagnosis of most patients and identification of heterozygous carriers.

Cloning of human and rat cDNAs encoding the mitochondrial single-stranded DNA-binding protein (SSB)

We have retro-transcribed and amplified by PCR the full-length cDNAs specifying the rat and human precursors of the single-stranded mitochondrial DNA (mtDNA)-binding protein (mtSSB). Each deduced sequence is composed of a 16-amino-acid (aa) N-terminal basic pre-sequence and a mature protein (132 aa in humans and 135 aa in the rat). The mature proteins are highly conserved among themselves and with the mtSSB from Xenopus laevis (Xl). Moreover, three regions of the protein are similar to corresponding domains of the SSB of Escherichia coli and to the E. coli F-sex factor SSB, indicating the existence of a broad class of DNA-binding proteins with structural and functional similarities both in prokaryotes and in prokaryote-derived organelles of higher organisms.

A MERRF/MELAS overlap syndrome associated with a new point mutation in the mitochondrial DNA tRNA(Lys) gene

Several members of a three-generation kindred from Sardinia were affected by a maternally inherited syndrome characterized by features of both myoclonus epilepsy with ragged-red fibers (MERRF) and mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). Clinically, symptoms such as myoclonus epilepsy, neural deafness and ataxia were variably associated with stroke-like episodes and/or migrainous attacks. Morphologically, numerous MELAS-associated SDH-stained vessels were observed in muscle biopsies, either alone or in combination with ragged-red fibers, the morphological hallmark of MERRF. Sequence analysis of the mtDNA tRNA genes revealed the presence of a single, heteroplasmic T-->C transition at nt 8356, in the region of the tRNA(Lys) gene corresponding to the T-psi-C stem. The T-->C(8356) transition was exclusively found in the maternal lineage of our family, and the relative amount of the mutant mtDNA species in muscle was correlated with the severity of the clinical presentation. Therefore, we propose that the T-->C(8356) transition is responsible for the mitochondrial encephalomyopathy found in our family, and must be added to the expanding list of the pathogenetically relevant mutations of human mtDNA.

Molecular characterization of inherited carnitine palmitoyltransferase II deficiency

Deficiency of carnitine palmitoyltransferase II (CPTase II; palmitoyl-CoA:L-carnitine O-palmitoyltransferase, EC 2.3.1.21) is a clinically heterogeneous autosomal recessive disorder of energy metabolism. We studied the molecular basis of CPTase II deficiency in an early-onset patient presenting with hypoketotic hypoglycemia and cardiomyopathy. cDNA and genomic DNA analysis demonstrated that the patient was homozygous for a mutant CPTase II allele (termed ICV), which carried three missense mutations: a G-1203----A transition, predicting a Val-368----Ile substitution (V368I); a C-1992----T transition, predicting an Arg-631----Cys substitution (R631C); and an A-2040----G transition, predicting a Met-647----Val substitution (M647V). Genomic DNA analysis of family members showed that the mutations cosegregated with the disease in the family. However, screening of 59 healthy controls demonstrated that both the V368I and M647V mutations are sequence polymorphisms with allele frequencies of 0.5 and 0.25, respectively. By contrast, the R631C substitution was not detected in 22 normal individuals or in 12 of 14 CPTase II-deficient patients with the adult muscular form. Notably, 2 adult CPTase II-deficient patients were heterozygous for the ICV allele, thus suggesting compound heterozygosity for this and a different mutant allele. The consequences of the three mutations on enzyme activity were investigated by expressing normal and mutated CPTase II cDNAs in COS cells. The R631C substitution drastically depressed the catalytic activity of CPTase II, thus confirming that this is the crucial mutation. Interestingly, the V368I and M647V substitutions, which did not affect enzyme activity alone, exacerbated the effects of the R631C substitution. Biochemical characterization of mutant CPTase II in patient's cells showed that the mutations are associated with (i) severe reduction of Vmax (approximately 90%), (ii) normal apparent Km values, and (iii) decreased protein stability.

Peripheral sensory-motor polyneuropathy, pigmentary retinopathy, and fatal cardiomyopathy in long-chain 3-hydroxy-acyl-CoA dehydrogenase deficiency

An 11-month-old girl presented acute episodes of hypoglycaemia and hepatic encephalopathy reminiscent of Reye syndrome and 3-hydroxydicarboxylic aciduria. The patient showed peculiar clinical manifestations of severe sensory-motor neuropathy, pigmentary retinopathy, and cardiomyopathy. She died of cardiac failure. Pathological studies of peripheral nerve showed signs of axonal neuropathy and demyelination. Enzymatic studies in cultured fibroblasts showed a deficiency of mitochondrial long-chain 3-hydroxyacyl-CoA-dehydrogenase. Peripheral nerve involvement and retinal pigmentary degeneration have as yet not been described in patients with proven defects of mitochondrial beta-oxidation.

Isolation and sub-chromosomal localization of a DNA fragment of the human choline acetyltransferase gene

A DNA fragment of 219 bp was obtained by polymerase chain reaction (PCR) on human genomic DNA using two oligonucleotide mixtures derived from peptide sequences of human placenta choline acetyltransferase (ChAT) and from partially conserved amino acid sequences of rat, porcine and Drosophila ChAT. Sequence homology with porcine ChAT demonstrated that this fragment is part of the human ChAT gene. This gene was assigned to chromosome 10 by hybridization of the 219 bp DNA probe with DNA from human-hamster somatic cell hybrids, and to region 10q11.2-10qter by PCR experiments.

Primary carnitine deficiency: heterozygote and intrafamilial phenotypic variation

Two boys from different families had primary carnitine deficiency: one had cardiomyopathy and myopathy, and the other had hypoglycemia and myopathy but no cardiomyopathy. Uptake of carnitine by cultured fibroblasts was negligible in both patients. Vmax for carnitine transport was reduced to 50% of controls' value in the parents and one brother (who had hypertrophic cardiomyopathy) of the first patient. A brother of the second non-cardiopathic patient died at an early age with autopsy findings of a dilated cardiomyopathy and low cardiac carnitine. Autosomal recessive primary carnitine deficiency can express a variable phenotype in different families as well as within the same family. Heterozygotes can manifest heart involvement.

Riboflavin responsive multiple acyl-CoA dehydrogenase deficiency: functional evaluation of recovery after high dose vitamin supplementation

The effect of riboflavin supplementation on muscle performance and exercise metabolism was investigated in four patients with multiple acyl-coenzyme A dehydrogenase deficiency (MAD). Maximum oxygen consumption and endurance measurements were performed to assess the patients' aerobic capacity and energy metabolism during exercise. They were tested before and after treatment with pharmacological doses of riboflavin. The initially low maximum oxygen consumption and high levels of blood lactate during submaximal exercise suggest that the oxidation of both fatty acids and carbohydrates was severely impaired. All four patients experienced a dramatic improvement in aerobic performance under riboflavin supplementation.