Empowering personalized pharmacogenomics with generative AI solutions

OBJECTIVE

This study evaluates an AI assistant developed using OpenAI's GPT-4 for interpreting pharmacogenomic (PGx) testing results, aiming to improve decision-making and knowledge sharing in clinical genetics and to enhance patient care with equitable access.

MATERIALS AND METHODS

The AI assistant employs retrieval-augmented generation (RAG), which combines retrieval and generative techniques, by harnessing a knowledge base (KB) that comprises data from the Clinical Pharmacogenetics Implementation Consortium (CPIC). It uses context-aware GPT-4 to generate tailored responses to user queries from this KB, further refined through prompt engineering and guardrails.

RESULTS

Evaluated against a specialized PGx question catalog, the AI assistant showed high efficacy in addressing user queries. Compared with OpenAI's ChatGPT 3.5, it demonstrated better performance, especially in provider-specific queries requiring specialized data and citations. Key areas for improvement include enhancing accuracy, relevancy, and representative language in responses.

DISCUSSION

The integration of context-aware GPT-4 with RAG significantly enhanced the AI assistant's utility. RAG's ability to incorporate domain-specific CPIC data, including recent literature, proved beneficial. Challenges persist, such as the need for specialized genetic/PGx models to improve accuracy and relevancy and addressing ethical, regulatory, and safety concerns.

CONCLUSION

This study underscores generative AI's potential for transforming healthcare provider support and patient accessibility to complex pharmacogenomic information. While careful implementation of large language models like GPT-4 is necessary, it is clear that they can substantially improve understanding of pharmacogenomic data. With further development, these tools could augment healthcare expertise, provider productivity, and the delivery of equitable, patient-centered healthcare services.

No evidence that G6PD deficiency affects the efficacy or safety of daunorubicin in acute lymphoblastic leukemia induction therapy

BACKGROUND/OBJECTIVES

Anthracyclines are used in induction therapy of pediatric acute lymphoblastic leukemia (ALL) and are known to generate oxidative stress; whether this translates into enhanced antileukemic activity or hemolytic effects in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency is unknown.

DESIGN/METHODS

Among 726 pediatric patients with newly diagnosed ALL treated at St. Jude Children's Research Hospital, 22 had deficient G6PD activity. We compared the prevalence of positive minimal residual disease (MRD) ≥1% at Day 15/Day 19 of induction or ≥0.01% at Day 42/Day 46 (end of induction) and the number of red blood cell (RBC) transfusions after daunorubicin in induction between patients with or without G6PD deficiency, adjusting for ALL risk group, treatment protocol, age, and gender.

RESULTS

There was no difference in Day 15/19 (P = 1) or end of induction MRD (P = 0.76) nor in the number of RBC transfusions (P = 0.73); the lack of association with MRD was confirmed in a dataset of 1192 newly diagnosed male patients enrolled in a Children's Oncology Group trial (P = 0.78).

CONCLUSION

We found no evidence that G6PD deficiency affects daunorubicin activity during induction treatment for ALL.

Transcriptomic characterization of signaling pathways associated with osteoblastic differentiation of MC-3T3E1 cells

Bone remodeling involves the coordinated actions of osteoclasts, which resorb the calcified bony matrix, and osteoblasts, which refill erosion pits created by osteoclasts to restore skeletal integrity and adapt to changes in mechanical load. Osteoblasts are derived from pluripotent mesenchymal stem cell precursors, which undergo differentiation under the influence of a host of local and environmental cues. To characterize the autocrine/paracrine signaling networks associated with osteoblast maturation and function, we performed gene network analysis using complementary “agnostic” DNA microarray and “targeted” NanoString nCounter datasets derived from murine MC3T3-E1 cells induced to undergo synchronized osteoblastic differentiation in vitro. Pairwise datasets representing changes in gene expression associated with growth arrest (day 2 to 5 in culture), differentiation (day 5 to 10 in culture), and osteoblast maturation (day 10 to 28 in culture) were analyzed using Ingenuity Systems Pathways Analysis to generate predictions about signaling pathway activity based on the temporal sequence of changes in target gene expression. Our data indicate that some pathways involved in osteoblast differentiation, e.g. Wnt/β-catenin signaling, are most active early in the process, while others, e.g. TGFβ/BMP, cytokine/JAK-STAT and TNFα/RANKL signaling, increase in activity as differentiation progresses. Collectively, these pathways contribute to the sequential expression of genes involved in the synthesis and mineralization of extracellular matrix. These results provide insight into the temporal coordination and complex interplay between signaling networks controlling gene expression during osteoblast differentiation. A more complete understanding of these processes may aid the discovery of novel methods to promote osteoblast development for the treatment of conditions characterized by low bone mineral density.

Concordance between glucose-6-phosphate dehydrogenase (G6PD) genotype and phenotype and rasburicase use in patients with hematologic malignancies

Phenotypic rather than genotypic tests remain the gold standard for diagnosing glucose-6-phosphate dehydrogenase (G6PD) deficiency. However, with increasing use of genomic arrays and whole exome or genome sequencing, G6PD genetic data are increasingly available. We examined the utility of G6PD genetic data in patients with hematologic malignancies and the association of G6PD genotype and phenotype with rasburicase-induced methemoglobinemia. We analyzed G6PD activity for 990 patients. Genotype data were available from the Affymetrix DMET array (n=379), whole exome sequencing (n=374), and/or the Illumina exome array (n=634) for 645 patients. Medical records of 341 patients with methemoglobin measures were assessed for the administration of rasburicase. We observed 5 non-synonymous SNPs, 4 of which were known to be associated with deficient G6PD activity (WHO Class I-III). Genotyping 367 males resulted in a positive predictive value of 81.8% (47.8–96.8%), and two males with a Class I-III allele having normal activity both received a red blood cell transfusion prior to the activity assay. However, genotyping males had only 39.1% (20.5–61.2%) sensitivity. Two of the 12 heterozygous females had deficient G6PD activity. Rasburicase-induced methemoglobinemia occurred in 6 patients, 5 of whom had at least one Class I-III allele, despite 2 of these having normal G6PD activity. We conclude that although an apparent nondeficient genotype does not necessarily imply a normal phenotype, a deficient genotype result indicates a deficient phenotype in those without transfusions, and may be a useful adjuct to phenotype to prevent adverse drug reactions.

Children's understanding of multiplication and division: Insights from a pooled analysis of seven studies conducted across 7 years

Research suggests that children's conceptual understanding of multiplication and division is weak and that it remains poor well into the later elementary school years. Further, children's understanding of fundamental concepts such as inversion and associativity does not improve as they progress from grades 6 to 8. Instead, some children simply possess strong understanding while others do not. Other studies have identified an increase across these grades. The present investigation analyses data from seven studies of Grade 6 (n = 226), Grade 7 (n = 221), and Grade 8 (n = 216) children's three-term problem-solving (e.g., 3 × 24 ÷ 24 and 3 × 24 ÷ 6) and provides a unified account of multiplication and division understanding, one in which grade differences and individual variability coexist and are moderated by sex. Statement of contribution What is already known on this subject? Children's conceptual understanding of multiplication and division is weak and it is unclear whether it increases across the key grades of 6-8. Understanding of the inversion and associativity concepts is characterized by high individual variability, but grade and sex have never been found to be a contributing factor. What does this study add? A meta-analysis of seven data sets (n = 643) indicates that grade differences and individual variability coexist and are moderated by sex. Understanding increases across grade only for boys, but an equal number of boys and girls are in the top 10% of conceptual problem-solvers.

Understanding arithmetic concepts: Does operation matter?

Most research on children's arithmetic concepts is based on (a) additive concepts and (b) a single concept leading to possible limitations in current understanding about how children's knowledge of arithmetic concepts develops. In this study, both additive and multiplicative versions of six arithmetic concepts (identity, negation, commutativity, equivalence, inversion, and associativity) were investigated in Grades 5, 6, and 7. The multiplicative versions of the concepts were more weakly understood. No grade-related differences were found in conceptual knowledge, but older children were more accurate problem solvers. Individual differences were examined through cluster analyses. All children had a solid understanding of identity and negation. Some children had a strong understanding of all the concepts, both additive and multiplicative; some had a good understanding of equivalence or commutativity; and others had a weak understanding of commutativity, equivalence, inversion, and associativity. Associativity was the most difficult concept for all clusters. Grade did not predict cluster membership. Overall, these results demonstrate the breadth of individual variability in conceptual knowledge of arithmetic as well as the complexity in how children's understanding of arithmetic concepts develops.

Children's understanding of additive concepts

Most research on children's arithmetic concepts is based on one concept at a time, limiting the conclusions that can be made about how children's conceptual knowledge of arithmetic develops. This study examined six arithmetic concepts (identity, negation, commutativity, equivalence, inversion, and addition and subtraction associativity) in Grades 3, 4, and 5. Identity (a-0=a) and negation (a-a=0) were well understood, followed by moderate understanding of commutativity (a+b=b+a) and inversion (a+b-b=a), with weak understanding of equivalence (a+b+c=a+[b+c]) and associativity (a+b-c=[b-c]+a). Understanding increased across grade only for commutativity and equivalence. Four clusters were found: The Weak Concept cluster understood only identity and negation; the Two-Term Concept cluster also understood commutativity; the Inversion Concept cluster understood identity, negation, and inversion; and the Strong Concept cluster had the strongest understanding of all of the concepts. Grade 3 students tended to be in the Weak and Inversion Concept clusters, Grade 4 students were equally likely to be in any of the clusters, and Grade 5 students were most likely to be in the Two-Term and Strong Concept clusters. The findings of this study highlight that conclusions about the development of arithmetic concepts are highly dependent on which concepts are being assessed and underscore the need for multiple concepts to be investigated at the same time.

Conceptual knowledge of arithmetic for Chinese- and Canadian-educated adults

This study investigated whether Canadian- and Chinese-educated adults differ in their understanding of simple arithmetic concepts. Participants (n = 21 per group) solved 3-term addition and subtraction (e.g., 5 + 22 - 22 and 3 + 24 - 26) and multiplication and division (e.g., 2 × 28 ÷ 28 and 4 × 39 ÷ 13) problems. All problems could be solved more easily if conceptual knowledge of the relationship between the 2 operations in each problem was understood and applied. Accuracy, solution time, and immediately retrospective self-reports of problem-solving strategy data were collected. Participants also completed a timed arithmetic fluency task. Chinese-educated participants demonstrated stronger conceptual understanding of arithmetic on all problems and outperformed Canadian-educated participants on the fluency task. A cluster analysis revealed 4 groups of individuals: weak concept users, who rarely used conceptual knowledge to aid their problem solving; strong concept users, who almost exclusively used their conceptual knowledge to facilitate problem solving; addition and subtraction concept users, who frequently used conceptual knowledge except on difficult multiplication and division problems; and multiplication and division concept users, who frequently used conceptual knowledge except on difficult addition and subtraction problems. Chinese-educated participants were more likely to be in the strong concept clusters, and none were in the weak concept cluster, providing further evidence of stronger conceptual knowledge of arithmetic. These results demonstrate for the 1st time that there are strong cross-cultural differences in conceptual knowledge of simple arithmetic, even in adulthood. (PsycINFO Database Record

Socio-demographic factors, comorbidity and diagnostic delay among women diagnosed with cervical, endometrial or ovarian cancer

This study investigates the association between socio-demographic factors, comorbidity and diagnostic delay among gynaecological cancer patients. A questionnaire was sent to 1052 women diagnosed with cervical, endometrial or ovarian cancer between October 2006 and December 2007 in Denmark. Long patient delays were associated with diagnosis with a greater risk of experiencing long delays among women diagnosed with cervical and endometrial cancer as opposed to ovarian cancer. The risk of experiencing long GP referral delays was associated with residential area, with a greater risk of long delays in rural vs. urban areas. Long gynaecologist appointment delays were associated with younger age, while long secondary care delays were associated with living in a capital area and having comorbidity. Long total delays were associated with diagnosis with greater risk of experiencing long delays among women diagnosed with cervical and endometrial cancer as opposed to ovarian cancer, and with working as opposed to being retired. In conclusion, this study found that socio-demographic factors and comorbidity play a role in the probability of experiencing long delays. If delays in diagnosis are to be reduced, there must be increased recognition of the significance of symptoms among patients and interventions aimed at ensuring timely care by specialists.

The effect of post-injury depression on return to pre-injury function: a prospective cohort study

BACKGROUND

Millions of people seek emergency department (ED) care for injuries each year, the majority for minor injuries. Little is known about the effect of psychiatric co-morbid disorders that emerge after minor injury on functional recovery. This study examined the effect of post-injury depression on return to pre-injury levels of function.

METHOD

This was a longitudinal cohort study with follow-up at 3, 6 and 12 months post-injury: 275 adults were randomly selected from those presenting to the ED with minor injury; 248 were retained over the post-injury year. Function was measured with the Functional Status Questionnaire (FSQ). Psychiatric disorders were diagnosed using the Structured Clinical Interview for DSM-IV-TR disorders (SCID).

RESULTS

During the post-injury year, 18.1% [95% confidence interval (CI) 13.3-22.9] were diagnosed with depression. Adjusting for clinical and demographic covariates, the depressed group was less likely to return to pre-injury levels of activities of daily living [odds ratio (OR) 8.37, 95% CI 3.78-18.53] and instrumental activities of daily living (OR 3.25, 95% CI 1.44-7.31), less likely to return to pre-injury work status (OR 2.37, 95% CI 1.04-5.38), and more likely to spend days in bed because of health (OR 2.41, 95% CI 1.15-5.07).

CONCLUSIONS

Depression was the most frequent psychiatric diagnosis in the year after minor injury requiring emergency care. Individuals with depression did not return to pre-injury levels of function during the post-injury year.

A microgenetic study of simple division

How simple division strategies develop over a short period of time was examined with a microgenetic study. Grade 5 students (mean age = 10 years, 3 months) solved simple division problems in 8 weekly sessions. Performance improved with faster and more accurate responses across the study. Consistent with R. S. Siegler's (1996) overlapping waves model, strategies varied in their use. Direct retrieval increased, retrieval of multiplication facts remained steady, and addition facts, derived facts, and special tricks marginally decreased. Consistent with previous research, multiplication fact retrieval was the most common strategy, although it was slower and more error prone than direct retrieval. Strategy variability within and across individuals was striking across all of the sessions and underscores Siegler's (1996) assertion that development is in a constant transitional state.

Children’s understanding of the arithmetic concepts of inversion and associativity

Previous studies have shown that even preschoolers can solve inversion problems of the form a+b-b by using the knowledge that addition and subtraction are inverse operations. In this study, a new type of inversion problem of the form d x e/e was also examined. Grade 6 and 8 students solved inversion problems of both types as well as standard problems of the form a+b-c and d x e/f. Students in both grades used the inversion concept on both types of inversion problems, although older students used inversion more frequently and inversion was used most frequently on the addition/subtraction problems. No transfer effects were found from one type of inversion problem to the other. Students who used the concept of associativity on the addition/subtraction standard problems (e.g., a+b-c=[b-c]+a) were more likely to use the concept of inversion on the inversion problems, although overall implementation of the associativity concept was infrequent. The findings suggest that further study of inversion and associativity is important for understanding conceptual development in arithmetic.

Cognitive functioning in sporadic amyotrophic lateral sclerosis: a six month longitudinal study

OBJECTIVE

To observe changes in cognition over six months in subjects with recently diagnosed sporadic amyotrophic lateral sclerosis (ALS).

METHODS

The study used a between-group and within-group longitudinal design. Nineteen ALS subjects and eight matched caregivers were recruited to participate in baseline neuropsychological assessments that were repeated six months later. Between group comparisons for these variables were undertaken at baseline and six months later. Within group/across time comparisons for these variables were carried out for both groups. Individual analyses for the neuropsychological variables using z scores were done for the ALS subjects using their baseline performance as the basis for comparison with their six month performance.

RESULTS

The between-group and within-group comparisons did not show significant differences in cognitive function over time. In individual analyses, however, seven of 19 ALS subjects (36.84%) developed abnormal neuropsychological performance over six months.

CONCLUSIONS

Early in the disease course, over one third of the ALS subjects developed cognitive deficits over six months. These findings support the hypothesis that cognitive deficits in ALS become more prominent over time.

Stability and change in children’s division strategies

Age-related changes in children's performance on simple division problems (e.g., 6/2, 72/9) were investigated by asking children in Grades 4 through 7 to solve 32 simple division problems. Differences in performance were found across grade, with younger children performing more slowly and less accurately than older children. Problem size effects were also found in that children were faster and more accurate on small problems than on large problems. Two strategies changed across age, with children in Grade 4 relying heavily on the strategy of "addition" (adding the divisor until the dividend was reached) to solve the problems and children in Grades 5 through 7 relying primarily on the strategy of "multiplication" (recasting the division problem as a multiplication problem) to solve the problems. Surprisingly, the frequency of direct retrieval (retrieving the answer directly from memory) did not increase across grade and never became the dominant strategy of choice. Reasons for why retrieval use remains infrequent and age invariant are discussed. Overall, the results suggest that division is a unique operation and that the continued study of division may have implications for further understanding of how procedural and conceptual knowledge of arithmetic develops.

Adults' understanding of inversion concepts: how does performance on addition and subtraction inversion problems compare to performance on multiplication and division inversion problems?

Problems of the form a + b - b have been used to assess conceptual understanding of the relationship between addition and subtraction. No study has investigated the same relationship between multiplication and division on problems of the form d x e / e. In both types of inversion problems, no calculation is required if the inverse relationship between the operations is understood. Adult participants solved addition/subtraction and multiplication/division inversion (e.g., 9 x 22 / 22) and standard (e.g., 2 + 27 - 28) problems. Participants started to use the inversion strategy earlier and more frequently on addition/subtraction problems. Participants took longer to solve both types of multiplication/division problems. Overall, conceptual understanding of the relationship between multiplication and division was not as strong as that between addition and subtraction. One explanation for this difference in performance is that the operation of division is more weakly represented and understood than the other operations and that this weakness affects performance on problems of the form d x e / e.

Adults' representations of division facts: a consequence of learning history?

There has been a recent increase in the study of adults' performance on simple division problems. Researchers up to now have focused on the relationship between multiplication and division and have found that multiplication often has a mediating role in the solution of division problems (Campbell, 1997, 1999; LeFevre & Morris, 1999; Mauro, LeFevre, & Morris, 2002). In this study, division was exclusively examined to determine the strategies that are used to solve these problems and to identify factors relating to particular strategy use. Thirty-two participants were asked to solve two sets of 64 simple division problems (from 4 divided by 2 to 81 divided by 9) and error, latency, and strategy report data were collected. Fewer errors were made on easy problems, which were also solved more quickly than difficult problems. Participants used retrieval, multiplication, and other strategies to solve the problems and tended to use retrieval more on easy than difficult problems and used multiplication more on difficult problems than easy problems. Unexpected age differences in strategy use were also found. Older participants tended to rely more heavily on retrieval than younger participants. These results suggest that older participants may have stronger representations for simple division problems than younger participants.

Leaf stomatal and epidermal cell development: identification of putative quantitative trait loci in relation to elevated carbon dioxide concentration in poplar

Genetic variation in stomatal initiation and density, and epidermal cell size and number were examined in a hybrid pedigree of Populus trichocarpa T. & G. and P. deltoides Marsh in both ambient ([aCO2]) and elevated ([eCO2]) concentrations of CO2. We aimed to link anatomical traits with the underlying genetic map of F2 Family 331, composed of 350 markers across 19 linkage groups. Leaf stomatal and epidermal cell traits showed pronounced differences between the original parents. We considered the following traits in the F2 population: stomatal density (SD), stomatal index (SI), epidermal cell area (ECA) and the number of epidermal cells per leaf (ECN). In [eCO2], adaxial SD and SI were reduced in the F2 population, whereas ECA increased and ECN remained unchanged. In [aCO2], four putative quantitative trait loci (QTL) with logarithm of the odds ratio (LOD) scores greater than 2.9 were found for stomatal traits on linkage group B: adaxial SI (LOD scores of 5.4 and 5.2); abaxial SI (LOD score of 3.3); and SD (LOD score of 3.2). These results imply that QTL for SI and SD share linkage group B and are under genetic control. More moderate LOD scores (LOD scores >/= 2.5) suggest QTL for SI on linkage groups A and B and for SD on linkage groups B, D and X with a probable co-locating quantitative trait locus for SI and SD on linkage group D (position 46.3 cM). The QTL in both [aCO2] and [eCO2] for adaxial SD were co-located on linkage group X (LOD scores of 3.5 and 2.6, respectively) indicating a similar response across both treatments. Putative QTL were located on linkage group A (position 89.2 cM) for both leaf size and ECN in [aCO2] and for ECA at almost the same position. The data provide preliminary evidence that leaf stomatal and cell traits are amenable to QTL analysis.

Problem behaviour, caregiver reactions, and impact among caregivers of persons with Alzheimer's disease

BACKGROUND

Problem behaviours that occur during Alzheimer's disease (AD) can have major impact on caregivers. How caregivers react to these behaviours may determine the total impact experienced from caregiving.

PURPOSE

This study examined the relationships between problematic behaviours and caregiving impact in 30 primary caregivers of persons with AD. The first question explored the relationship between frequency of problem behaviour and impact; the second explored the relationship between caregiver reactions to problem behaviours and impact from caregiving.

METHODS

The frequency of problem behaviour and the caregiver reaction was measured using The Revised Memory and Behaviour Problem Checklist (Teri et al. 1992). The impact from caregiving was operationalized using the Cost of Care Index developed by Kosberg and Cairl (1986).

RESULTS

Significant associations were found for 11 of the 20 subscales that measured the association between the frequency of problem behaviour in the client and the impact from caregiving experienced by the caregiver. In comparison, the association between caregiver's reaction to problem behaviours and impact from caregiving was even more significant in value with 15 subscales of 20 being significant. Female caregivers experienced a greater reaction to disruptive and depressive behaviour when compared with male caregivers even though both genders reported similar frequencies of problem behaviours. In regard to findings about the impact from caregiving, four of the six indicators were higher for women than for men.

CONCLUSIONS

Caregiver reaction to problem behaviours was more highly associated with impact from caregiving than the actual frequency of the behaviours. These findings have great implications for intervention programs. Caregivers, especially females, need to receive individualized, specific education/training on how to understand and manage disruptive and depressive behaviour in persons with AD.

Unsolicited narratives from the Internet: a rich source of qualitative data

Recently, the Internet has become a forum for informal communication. Many--whose voices may have been unheard--can now express themselves through this medium. Rich narratives are available to the qualitative researcher from bulletin boards, guestbooks, Web pages, and listservs on the Internet. In this article, these data sources are defined and described. Strategies for using these data are discussed. One concern with using unsolicited data from the Internet is the protection of human subjects and the requirement for consent. A proposed model describing the process for deciding when such data are publicly available, as defined by the Office for the Protection of Rights of Research Subjects, and when the use of the data requires consent is presented.

Rehabilitation applications in caring for patients with Pick's disease and frontotemporal dementias

The basic principles of rehabilitation philosophy relevant to the care of patients with neurodegenerative diseases, specifically Pick's disease and frontotemporal dementias, are briefly defined. These principles are illustrated by the case study of a patient with a clinical diagnosis of Pick's disease.

Respite Care-Volunteers as Providers

1. Although many studies examine the impact of respite care on caregivers, few studies have examined the impact of such programs on the volunteer respite provider. Results of such formative evaluation studies must be antecedent to the question of whether respite care "works." 2. Fear of persons with Alzheimer's Disease (AD) was a consistent theme verbalized in this study. Educational programs must therefore include more exposure to actual persons with AD. 3. Caregivers with some past experience composed the majority of volunteers in this group (n = 78%). Recruiting former caregivers of deceased persons with AD may be fruitful future areas of study.

Chromatin, TAFs, and a novel multiprotein coactivator are required for synergistic activation by Sp1 and SREBP-1a in vitro

The promoter selectivity factor Sp1 often cooperates with other enhancer-binding proteins to activate transcription. To study the molecular underpinnings of these regulatory events, we have reconstituted in vitro the synergy observed in vivo between Sp1 and the sterol-regulated factor SREBP-1a at the low density lipoprotein receptor (LDLR) promoter. Using a highly purified human transcription system, we found that chromatin, TAFs, and a novel SREBP-binding coactivator activity, which includes CBP, are all required to mediate full synergistic activation by Sp1 and SREBP-1a. The SREBP-binding domain of CBP inhibits activation by SREBP-1a and Sp1 in a dominant-negative fashion that is both chromatin- and activator-specific. Whereas recombinant CBP alone is not sufficient to mediate activation, a human cellular fraction containing CBP can support high levels of chromatin-dependent synergistic activation. Purification of this activity to near homogeneity resulted in the identification of a multiprotein coactivator, including CBP, that selectively binds to the SREBP-1a activation domain and is capable of mediating high levels of synergistic activation by SREBP/Sp1 on chromatin templates. The development of a reconstituted chromatin transcription system has allowed us to isolate a novel coactivator that is recruited by the SREBP-1a activation domain and that functions in concert with TFIID to coordinate the action of multiple activators at complex promoters in the context of chromatin.

Lexical acquisition in probable Alzheimer's disease

Patients with probable Alzheimer's disease (pAD) were exposed to a new verb in a naturalistic fashion. We probed their knowledge of the word's semantic and grammatical characteristics for several minutes following this exposure, and compared this with their performance on parallel measures assessing known words. Significant differences were seen between pAD patients and controls in the acquisition of the new verb's semantic meaning and its argument structure, but pAD patients did not differ from controls in the acquisition of the new word's grammatical form class. Individual patient analyses demonstrated parallel deficits restricted to the semantic meaning and argument structure of the new word and known words in several pAD patients, suggesting that a selective language impairment contributed to their word learning deficit. This pattern is consistent with an intimate relationship between semantic meaning and argument structure in semantic memory. Other pAD patients had difficulty learning about all aspects of the new word, despite good performance with known words, suggesting that compromised memory may have limited their lexical acquisition.

Family caregiving: who provides the care, and at what cost?

Today, there are an estimated 1.6 million people over 65 years of age who require assistance with two or more daily activities. This number is projected to rise to 2.1 million by 2001, with fewer family caregivers expected to be available to provide this informal care. Seventy-two percent of unpaid family caregivers are women, the majority of whom are mid-life daughters or daughters in law. Uncompensated care to the frail elderly requires an average of 28 to 39.9 hours per week of custodial care. The financial impact on informal caregivers includes: 9% of family caregivers who leave the labor force to provide care, 29.4% who adjust their work schedules, and 18.1% who take time off without pay. The estimated annual value of uncompensated kin care in 1990 was $18 billion. Thirty-two percent of all family caregivers are categorized as poor or near-poor at incomes that are less than 125% of the federal poverty level.

The family's role in long-term care

Long-term care provided by family members is the central care of our current health care system. The purpose of this article is to review the family's role in long-term care. Issues such as cost containment and inequities in our current social policy are reviewed. Suggestions for future directions in social policy are presented.

The COQ5 gene encodes a yeast mitochondrial protein necessary for ubiquinone biosynthesis and the assembly of the respiratory chain

Saccharomyces cerevisiae is a facultative anaerobe capable of meeting its energy requirements by fermentation and is thus an ideal system for studying the biogenesis of respiring mitochondria. We have isolated a respiration-deficient mutant exhibiting a pleiotropic loss of the mitochondrial electron transport chain. The corresponding wild-type gene, COQ5, was cloned, sequenced, and able to restore respiratory growth. Deletion of the chromosomal COQ5 gene results in a respiration deficiency and reduced levels of respiratory protein components. Exogenously added decylubiquinone can partially restore electron transport chain function to mitochondrial membranes from the deletion mutant. The COQ5 nucleotide sequence predicts a polypeptide of 307 amino acids containing a mitochondrial targeting signal. COQ5p is 43% identical to the polypeptide predicted by the Escherichia coli open reading frame, o251 (1). The COQ5 gene, when introduced into E. coli, complements the respiratory deficiency of an ubiE mutant that maps near o251, suggesting that it is the yeast homolog of the ubiE gene product. We conclude that the COQ5 gene encodes the mitochondria-localized 2-hexaprenyl-6-methoxy-1,4-benzoquinone methyltransferase of the yeast ubiquinone biosynthetic pathway.

Anomaly judgments of subject-predicate relations in Alzheimer's disease

Claims that patients with probable Alzheimer's disease (AD) have semantic memory difficulty have received equivocal support. A common assumption has been that defining or core information determines the truth value of word meaning on measures requiring semantic memory such as category membership judgments or confrontation naming, but this assumption may not be valid. In the present study, we assessed the comprehension of subject-predicate sentences independent of their truth value by asking AD patients to judge the coherence of statements such as "The tulip is tall" or "*The tulip is jealous." We found that AD patients are significantly more impaired than controls at judging the coherence of these simple subject-predicate sentences. Moreover, AD patients were more successful at judging the coherence of statements that contain attributes with a narrow scope of reference compared to attributes with a broad scope of reference. These findings support the hypothesis that AD patients have a semantic memory impairment and suggest a specific deficit processing the network of semantic relations underlying word meaning in semantic memory.

Language comprehension profiles in Alzheimer's disease, multi-infarct dementia, and frontotemporal degeneration

We assessed language functioning in 116 age-, education-, and severity-matched patients with the clinical diagnosis of Alzheimer's disease (AD), multi-infarct dementia (MID) due to small-vessel ischemic disease, or a frontotemporal form of degeneration (FD). Assessments of comprehension revealed that patients with AD are significantly impaired in their judgments of single word and picture meaning, whereas patients with FD had sentence comprehension difficulty due to impaired processing of grammatical phrase structure. Patients with MID did not differ from control subjects in their comprehension performance. Traditional aphasiologic measures did not distinguish between AD, MID, and FD. Selective patterns of comprehension difficulty in patients with different forms of dementia emphasize that language deficits cannot be explained entirely by the compromised memory associated with a progressive neurodegenerative illness.

Category-specific difficulty naming with verbs in Alzheimer's disease

We studied 20 patients with Alzheimer's disease (AD) on a picture-naming task consisting of frequency-matched pairs of nouns and verbs that were homophonic and homographic (e.g., paint). Intragroup comparisons revealed that verb naming is significantly more difficult for patients with AD than noun naming. An error analysis demonstrated that patients with AD produce significantly more semantic and descriptive errors for verbs than nouns. We correlated verb naming and noun naming with measures of grammatical comprehension, lexical retrieval, and visuoperceptual processing, but there were no selective effects for verbs compared with nouns. Differences in the mental representation of concepts underlying verbs and nouns may account, in part, for the relative difficulty naming with verbs in AD.

Freehand drawing impairments in probable Alzheimer's disease

We evaluated freehand picture production of familiar objects in patients with probable Alzheimer's disease. The overall recognizability of their drawings was significantly compromised. Error analyses revealed the production of category violations and the frequent inclusion of incorrect features in a picture that were borrowed from semantically related objects, suggesting difficulty distinguishing between items with overlapping features sets in semantic memory. Analyses of individual patient drawing profiles also revealed that some patients are disproportionately compromised in expressing a particular perceptual feature, implicating difficulty at the level of perceptual processing. Regression analyses demonstrated the contribution of limited visual attentional resources. We conclude that impaired freehand drawing in probable Alzheimer's disease is multifactorial in nature.

A requirement for matrix processing peptidase but not for mitochondrial chaperonin in the covalent attachment of FAD to the yeast succinate dehydrogenase flavoprotein

Succinate dehydrogenase (EC 1.3.99.1) in the yeast Saccharomyces cerevisiae is a mitochondrial heterotetramer containing a flavoprotein subunit with an 8alpha-N(3)-histidyl-linked FAD cofactor. The covalent linkage of the FAD is necessary for activity. We have developed an in vitro assay that measures the flavinylation of the flavoprotein precursor in mitochondrial matrix fractions. Flavoprotein modification does not depend on translocation across a membrane, but it does require proteolytic processing by the mitochondrial processing peptidase prior to flavin attachment. Since ATP depletion, N-ethylmaleimide, or proteinase treatments of matrix fractions inhibit flavoprotein modification, at least one additional matrix protein component appears to be required. Having previously suggested that the flavoprotein begins folding before FAD attachment occurs, we tested whether the mitochondrial chaperonin, heat shock protein 60, might be necessary. Co-immunoprecipitation of the flavoprotein and the chaperonin demonstrate that the proteins do indeed interact. However, immunodepletion of the chaperonin from matrix fractions does not inhibit FAD attachment. Nonprotein components are also required for flavoprotein modification. In addition to ATP, effector molecules such as succinate, fumarate, or malate also stimulate modification. Together, these results suggest that FAD addition is an early event in succinate dehydrogenase assembly.

Covalent attachment of FAD to the yeast succinate dehydrogenase flavoprotein requires import into mitochondria, presequence removal, and folding

Succinate dehydrogenase (EC 1.3.99.1) in the yeast Saccharomyces cerevisiae is a mitochondrial respiratory chain enzyme that utilizes the cofactor, FAD, to catalyze the oxidation of succinate and the reduction of ubiqinone. The succinate dehydrogenase enzyme is a heterotetramer composed of a flavoprotein, an iron-sulfur protein, and two hydrophobic subunits. The FAD is covalently attached to a histidine residue near the amino terminus of the flavoprotein. In this study, we have investigated the attachment of the FAD cofactor with the use of an antiserum that specifically recognizes FAD and hence, can discriminate between apo- and holoflavoproteins. Cofactor attachment, both in vivo and in vitro, occurs within the mitochondrial matrix once the presequence has been cleaved. FAD attachment is stimulated by, but not dependent upon, the presence of the iron-sulfur subunit and citric acid cycle intermediates such as succinate, malate, or fumarate. Furthermore, this modification does not occur with C-terminally truncated flavoprotein subunits that are fully competent for import. Taken together, these data suggest that cofactor addition occurs to an imported protein that has folded sufficiently to recognize both FAD and its substrate.

Phonologic processing deficits in Alzheimer's disease

We investigated phonologic production in patients with mild to moderate Alzheimer's disease (AD) on a repetition task. AD patients produced significantly more speech errors than age-matched controls. AD patients' errors, unlike those of controls, resulted in the transformation of real words into pseudowords, occurred disproportionately in word-initial positions, and were not influenced by the phonologic environment. This pattern of errors suggests a lexical phonologic retrieval deficit in AD.

Sentence comprehension in multiple sclerosis

INTRODUCTION

Explanations of sentence processing difficulty in aphasia have implicated slowed information processing speed. We tested this hypothesis by evaluating sentence comprehension in multiple sclerosis (MS), and relating comprehension performance to measures of information processing speed.

MATERIAL & METHODS

Twenty right-handed, high school-educated, non-demented, native English speakers with clinically definite MS and 16 age- and education-matched control subjects were examined on 3 different sentence comprehension measures that stress grammatical appreciation. Performance was related to quantitative assessments of mental information processing speed.

RESULTS

Group-wide analyses demonstrated a trend toward sentence comprehension difficulty in MS. Analyses of individual patient profiles identified a subgroup of MS patients who were consistently impaired to a significant extent across all sentence comprehension tasks. Their sentence comprehension difficulty was associated with selectively compromised mental information processing speed.

CONCLUSION

Sentence comprehension difficulty in MS is associated with slowed information processing speed. This finding supports the claim that information processing speed contributes to sentence processing.

The relationship between health and social support in caregiving wives as perceived by significant others

This study explored the relationship between health and social support in wives who care for husbands with dementia. In order to understand how significant others begin mobilizing help for caregivers, the significant others' views of the carers' health and social support were analysed. Subjects comprised 75 significant others identified as being familiar with the caregiving situation of a like number of caregiving wives. Hypotheses, which were rejected, predicted that wife caregivers perceived as ill by the significant other would be seen as needing and receiving more social support as reported by the significant other. Findings indicated that healthy caregivers were perceived to have significantly more people in their social network.

Spirituality among caregivers

The spiritual perspectives of 17 caregiver wives of dementia victims and 23 noncaregiving wives of healthy adults were compared in a pilot study using a convenience sample. Caregiver wives used symbols such as God, and spiritual behaviors such as prayer and forgiveness as coping mechanisms. Caregivers tended to share the problems and joys of living according to their spiritual belief more often than the noncaregiver wives of healthy adults. Caregivers also engaged in private prayer and sought spiritual guidance in making decisions in their everyday life more often. The findings suggest that nursing interventions with churches as a natural network for caregivers may be useful. Prayer, forgiveness, and spiritual reading materials are resources that may be helpful to some caregivers.

The covalent attachment of FAD to the flavoprotein of Saccharomyces cerevisiae succinate dehydrogenase is not necessary for import and assembly into mitochondria

Succinate dehydrogenase of the bacterial or inner mitochondrial membrane catalyses the oxidation of succinate to fumarate and directs reducing equivalents into the electron-transport chain. The enzyme is also able to catalyse the reverse reaction, the reduction of fumarate to succinate. The enzyme is composed of four subunits. These subunits include a catalytic dimer composed of a flavoprotein subunit with a covalently bound FAD, and an iron-sulfur protein subunit with three different iron-sulfur centres, which is anchored to the membrane by two smaller integral membrane proteins. The FAD moiety is attached to the flavoprotein subunit by an 8 alpha-[N(3)-histidyl]FAD linkage at a conserved histidine residue, His90 of the Saccharomyces cerevisiae succinate dehydrogenase. By mutating His90 to a serine residue, we have constructed a flavoprotein subunit that is unable to covalently bind FAD. The mutant flavoprotein is targeted to mitochondria, translocated across the mitochondrial membranes, and is assembled with the other subunits where it binds FAD non-covalently. The resulting holoenzyme has no succinate-dehydrogenase activity but retains fumarate reductase activity. The covalent attachment of FAD is therefore necessary for succinate oxidation but is dispensable for both fumarate reduction and for the import and assembly of the flavoprotein subunit.

MDL 29311, an analog of probucol, decreases triglycerides in rats by increasing hepatic clearance of very-low-density lipoprotein

MDL 29311 is an analog of probucol that shares probucol's antioxidant and antiatherogenic properties. When fed to rats as a 1% dietary admixture, MDL 29311 decreased triglyceride levels by 65% without affecting total or high-density lipoprotein (HDL) cholesterol levels. Under the same conditions, probucol decreased triglyceride levels by 23% and total cholesterol levels by 29% (with a corresponding decrease in HDL cholesterol level). MDL 29311 treatment did not affect the rate of triglyceride entry into the plasma. However, MDL 29311-treated rats cleared in vivo-labeled very-low-density lipoprotein (VLDL)-associated [3H]-triglyceride ([3H]-VLDL) over threefold faster than control rats. This increase in clearance led to increased levels of [3H]-lipid in liver and decreased [3H]-lipid in fat, muscle, diaphragm, and kidney of MDL 29311-treated rats 1.5 to 2.0 minutes after injection of [3H]-VLDL. MDL 29311 treatment had no effect on lipoprotein lipase (LPL) or hepatic triglyceride lipase (H-TGL) activities, or on plasma apolipoprotein (apo) C-II-dependent LPL activation. Intravenously injected [3H]-VLDL was allowed to circulate in MDL 29311-treated or control rats for 1 minute, and the undiluted plasma was then perfused through rat livers in a recirculating system. The [3H] in MDL 29311 plasma was cleared threefold faster (t1/2, 1.3 v 3.8 minutes) than the [3H] in control plasma by control livers. Conversely, the [3H] in control plasma was cleared slowly (t1/2 = 3.5 minutes) by the livers of MDL 29311-treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Antioxidant MDL 29,311 prevents diabetes in nonobese diabetic and multiple low-dose STZ-injected mice

Recent investigations suggest a role for antioxidants in preventing IDDM. MDL 29,311 (4,4'-[methylenebis(thio)]bis](1,1- dimethylethyl)]-phenol) is an analogue of the antioxidant probucol. Administered as a 1% dietary admixture to female nonobese diabetic mice from 4 to 24 wk of age, MDL reduced the prevalence of diabetes from 49 to 4% at 24 wk of age (n = 50-61/group). Discontinuation of treatment at 24 wk of age did not result in a rapid onset of diabetes. Probucol (1%) did not prevent diabetes. Initiating MDL treatment at 4 or 8 wk of age was more effective (19 and 17%, respectively, compared with 60% in control mice) than initiating treatment at 12 wk of age (30% diabetic; n = 28-35/group). A lower dose of MDL (0.1%), started at 4 wk of age, decreased the prevalence of diabetes to 36%. Histopathology indicated that MDL did not prevent insulitis. MDL (0.1%) also was evaluated in combination with immunosuppressants. Compared with control mice (65% diabetic), the combination of MDL and deflazacort was more effective (21% diabetic) than either agent alone (39% diabetic for MDL and 59% diabetic for deflazacort), whereas the effectiveness of MDL, cyclosporin, and MDL plus cyclosporin was similar (39, 38, and 34% diabetic, respectively). In another model of IDDM, the multiple-low-dose streptozocin-injected mouse, MDL (1%) also reduced the prevalence of diabetes when administered beginning 8 wk before streptozocin (55% diabetic vs. 100% of control mice; n = 20-25/group). Probucol (1%) was ineffective. MDL appears effective in preventing the onset of disease in two mouse models of IDDM.

MDL 29311. Antioxidant with marked lipid- and glucose-lowering activity in diabetic rats and mice

MDL 29311, an analogue of probucol, administered to rats as a 1% dietary admixture for 2 wk before and 5 days after intravenous injection of 40 mg/kg of ALX significantly (P < 0.05) reduced plasma glucose (6.9 +/- 0.3 vs. 19.2 +/- 1.3 mM) and serum triglyceride (0.17 +/- 0.01 vs. 1.82 +/- 0.39 mM) levels in overnight-fasted ALX-plus-MDL 29311-administered rats vs. ALX-administered rats. A cross-over study indicated that MDL 29311 did not attenuate the diabetogenic action of ALX, but rather, directly lowered glucose and triglycerides. In rats injected intravenously with 45, 65, or 85 mg/kg of STZ and then administered control or MDL 29311 diet for 7 days, MDL 29311 decreased fasted plasma glucose to nondiabetic levels, decreased fasted and nonfasted plasma triglycerides by 49-79%, but did not affect plasma insulin levels. In STZ-induced (65 mg/kg) diabetic rats, MDL 29311 attenuated the increase in plasma nonesterified fatty acids during an 18-h fast; had little or no effect on glucagon, pyruvate, lactate, beta-hydroxybutyrate, acetoacetate, or cholesterol; and did not induce hypoglycemia in rats fasted up to 64 h. In nonfasted hyperinsulinemic db/db mice treated for 10 wk, MDL 29311 significantly lowered glucose levels by 14-40%, triglyceride levels by 31-63% and GHb from 8.0 to 5.4%, and had no consistent effect on plasma insulin levels. Because of its marked glucose- and lipid-lowering activity in both nonfasted hyperinsulinemic and fasted insulinopenic animals, MDL 29311 merits additional investigation as a potential antidiabetic agent.