Holstein Friesian dairy cattle edited for diluted coat color as a potential adaptation to climate change

BACKGROUND

High-producing Holstein Friesian dairy cattle have a characteristic black and white coat, often with large proportions of black. Compared to a light coat color, black absorbs more solar radiation which is a contributing factor to heat stress in cattle. To better adapt dairy cattle to rapidly warming climates, we aimed to lighten their coat color by genome editing.

RESULTS

Using gRNA/Cas9-mediated editing, we introduced a three bp deletion in the pre-melanosomal protein 17 gene (PMEL) proposed as causative variant for the semi-dominant color dilution phenotype observed in Galloway and Highland cattle. Calves generated from cells with homozygous edits revealed a strong color dilution effect. Instead of the characteristic black and white markings of control calves generated from unedited cells, the edited calves displayed a novel grey and white coat pattern.

CONCLUSION

This, for the first time, verified the causative nature of the PMEL mutation for diluting the black coat color in cattle. Although only one of the calves was healthy at birth and later succumbed to a naval infection, the study showed the feasibility of generating such edited animals with the possibility to dissect the effects of the introgressed edit and other interfering allelic variants that might exist in individual cattle and accurately determine the impact of only the three bp change.

Novel DNA methylation signatures of tobacco smoking with trans-ethnic effects

BACKGROUND

Smoking remains one of the leading preventable causes of death. Smoking leaves a strong signature on the blood methylome as shown in multiple studies using the Infinium HumanMethylation450 BeadChip. Here, we explore novel blood methylation smoking signals on the Illumina MethylationEPIC BeadChip (EPIC) array, which also targets novel CpG-sites in enhancers.

METHOD

A smoking-methylation meta-analysis was carried out using EPIC DNA methylation profiles in 1407 blood samples from four UK population-based cohorts, including the MRC National Survey for Health and Development (NSHD) or 1946 British birth cohort, the National Child Development Study (NCDS) or 1958 birth cohort, the 1970 British Cohort Study (BCS70), and the TwinsUK cohort (TwinsUK). The overall discovery sample included 269 current, 497 former, and 643 never smokers. Replication was pursued in 3425 trans-ethnic samples, including 2325 American Indian individuals participating in the Strong Heart Study (SHS) in 1989-1991 and 1100 African-American participants in the Genetic Epidemiology Network of Arteriopathy Study (GENOA).

RESULTS

Altogether 952 CpG-sites in 500 genes were differentially methylated between smokers and never smokers after Bonferroni correction. There were 526 novel smoking-associated CpG-sites only profiled by the EPIC array, of which 486 (92%) replicated in a meta-analysis of the American Indian and African-American samples. Novel CpG sites mapped both to genes containing previously identified smoking-methylation signals and to 80 novel genes not previously linked to smoking, with the strongest novel signal in SLAMF7. Comparison of former versus never smokers identified that 37 of these sites were persistently differentially methylated after cessation, where 16 represented novel signals only profiled by the EPIC array. We observed a depletion of smoking-associated signals in CpG islands and an enrichment in enhancer regions, consistent with previous results.

CONCLUSION

This study identified novel smoking-associated signals as possible biomarkers of exposure to smoking and may help improve our understanding of smoking-related disease risk.

Brain-derived neurotrophic factor in human subjects with function-altering melanocortin-4 receptor variants

Background

In rodents, hypothalamic brain-derived neurotrophic factor (BDNF) expression appears to be regulated by melanocortin-4 receptor (MC4R) activity. The impact of MC4R genetic variation on circulating BDNF in humans is unknown.

Objective

To compare BDNF concentrations of subjects with loss-of-function (LOF) and gain-of-function (GOF) MC4R variants to those of controls with common sequence MC4R.

Methods

Circulating BDNF was measured in two cohorts with known MC4R sequence: 148 subjects of Pima Indian heritage ([mean±SD]: age 15.7±6.5y, BMI-Z 1.63±1.03), and 69 subjects of Hispanic heritage (10.8±3.6y, BMI-Z 1.57±1.07). MC4R variants were characterized in vitro by cell surface expression, receptor binding, and cAMP response after agonist administration. BDNF single nucleotide polymorphisms (SNPs) rs12291186, rs6265, and rs7124442 were also genotyped.

Results

In the Pima cohort, no significant differences in serum BDNF was observed for 43 LOF-subjects versus 65 LOF-matched controls [age-, sex-, and BMI-matched] (P=0.29), or 20 GOF-subjects versus 20 GOF-matched controls (P=0.40). Serum BDNF was significantly associated with genotype for BDNF rs12291186 (P=0.006) and rs6265 (P=0.009), but not rs7124442 (P=0.99); BDNF SNPs did not interact with MC4R status to predict serum BDNF. In the Hispanic cohort, plasma BDNF was not significantly different among 21 LOF-subjects, 20 GOF-subjects, and 28 controls (P=0.79); plasma BDNF was not predicted by BDNF genotype or BDNF-x-MC4R genotype interaction.

Conclusions

Circulating BDNF concentrations were not significantly associated with MC4R functional status, suggesting that peripheral BDNF does not directly reflect hypothalamic BDNF secretion and/or that MC4R signaling is not a significant regulator of the bulk of BDNF expression in humans.

Epidemiology and genetic determinants of progressive deterioration of glycaemia in American Indians: the Strong Heart Family Study

AIMS/HYPOTHESIS

Type 2 diabetes is a chronic, heterogeneous disease and a major risk factor for cardiovascular diseases. The underlying mechanisms leading to progression to type 2 diabetes are not fully understood and genetic tools may help to identify important pathways of glycaemic deterioration.

METHODS

Using prospective data on American Indians from the Strong Heart Family Study, we identified 373 individuals defined as progressors (diabetes incident cases), 566 individuals with transitory impaired fasting glucose (IFG) and 1,011 controls (normal fasting glycaemia at all visits). We estimated the heritability (h(2)) of the traits and the evidence for association with 16 known variants identified in type 2 diabetes genome-wide association studies.

RESULTS

We noted high h(2) for diabetes progression (h(2) = 0.65 ± 0.16, p = 2.7 × 10(-6)) but little contribution of genetic factors to transitory IFG (h(2) = 0.09 ± 0.10, p = 0.19) for models adjusted for multiple risk factors. At least three variants (in WFS1, TSPAN8 and THADA) were nominally associated with diabetes progression in age- and sex-adjusted analyses with estimates showing the same direction of effects as reported in the discovery European ancestry studies.

CONCLUSIONS/INTERPRETATION

Our findings do not exclude these loci for diabetes susceptibility in American Indians and suggest phenotypic heterogeneity of the IFG trait, which may have implications for genetic studies when diagnosis is based on a single time-point measure.

Transcriptomics of cortical gray matter thickness decline during normal aging

INTRODUCTION

We performed a whole-transcriptome correlation analysis, followed by the pathway enrichment and testing of innate immune response pathway analyses to evaluate the hypothesis that transcriptional activity can predict cortical gray matter thickness (GMT) variability during normal cerebral aging.

METHODS

Transcriptome and GMT data were available for 379 individuals (age range=28-85) community-dwelling members of large extended Mexican American families. Collection of transcriptome data preceded that of neuroimaging data by 17 years. Genome-wide gene transcriptome data consisted of 20,413 heritable lymphocytes-based transcripts. GMT measurements were performed from high-resolution (isotropic 800 μm) T1-weighted MRI. Transcriptome-wide and pathway enrichment analysis was used to classify genes correlated with GMT. Transcripts for sixty genes from seven innate immune pathways were tested as specific predictors of GMT variability.

RESULTS

Transcripts for eight genes (IGFBP3, LRRN3, CRIP2, SCD, IDS, TCF4, GATA3, and HN1) passed the transcriptome-wide significance threshold. Four orthogonal factors extracted from this set predicted 31.9% of the variability in the whole-brain and between 23.4 and 35% of regional GMT measurements. Pathway enrichment analysis identified six functional categories including cellular proliferation, aggregation, differentiation, viral infection, and metabolism. The integrin signaling pathway was significantly (p<10(-6)) enriched with GMT. Finally, three innate immune pathways (complement signaling, toll-receptors and scavenger and immunoglobulins) were significantly associated with GMT.

CONCLUSION

Expression activity for the genes that regulate cellular proliferation, adhesion, differentiation and inflammation can explain a significant proportion of individual variability in cortical GMT. Our findings suggest that normal cerebral aging is the product of a progressive decline in regenerative capacity and increased neuroinflammation.

Localization of a major susceptibility locus influencing preterm birth

Preterm birth (PTB) is a complex trait, but little is known regarding its major genetic determinants. The objective of this study is to localize genes that influence susceptibility to PTB in Mexican Americans (MAs), a minority population in the USA, using predominantly microfilmed birth certificate-based data obtained from the San Antonio Family Birth Weight Study. Only 1302 singleton births from 288 families with information on PTB and significant covariates were considered for genetic analysis. PTB is defined as a childbirth that occurs at <37 completed weeks of gestation, and the prevalence of PTB in this sample was 6.4%. An ∼10 cM genetic map was used to conduct a genome-wide linkage analysis using the program SOLAR. The heritability of PTB was high (h(2) ± SE: 0.75 ± 0.20) and significant (P = 4.5 × 10(-5)), after adjusting for the significant effects of birthweight and birth order. We found significant evidence for linkage of PTB (LOD = 3.6; nominal P = 2.3 × 10(-5); empirical P = 1.0 × 10(-5)) on chromosome 18q between markers D18S1364 and D18S541. Several other chromosomal regions (2q, 9p, 16q and 20q) were also potentially linked with PTB. A strong positional candidate gene in the 18q linked region is SERPINB2 or PAI-2, a member of the plasminogen activator system that is associated with various reproductive processes. In conclusion, to our knowledge, perhaps for the first time in MAs or US populations, we have localized a major susceptibility locus for PTB on chromosome 18q21.33-q23.

Olfactomedin-like 3 (OLFML3) gene expression in baboon and human ocular tissues: cornea, lens, uvea, and retina

BACKGROUND

Olfactomedin-like is a family of polyfunctional polymeric glycoproteins. This family has at least four members. One member of this family is OLFML3, which is preferentially expressed in placenta but is also detected in other adult tissues including the liver and heart. However, its orthologous rat gene is expressed in the iris, sclera, trabecular meshwork, retina, and optic nerve.

METHODS

OLFML3 messenger amplification was performed by RT-PCR from human and baboon ocular tissues. The products were cloned and sequenced.

RESULTS

We report OLFML3 expression in human and baboon eye. The full coding DNA sequence has 1221 bp, from which an open reading frame of 406 amino acid was obtained. The baboon OLFML3 gene nucleotidic sequence has 98% and amino acidic 99% similarity with humans.

CONCLUSIONS

OLFML3 gene expression in human and baboon ocular tissues and its high similarity make the baboon a powerful model to deduce the physiological and/or metabolic function of this protein in the eye.

A high-resolution 15,000(Rad) radiation hybrid panel for the domestic cat

The current genetic and recombination maps of the cat have fewer than 3,000 markers and a resolution limit greater than 1 Mb. To complement the first-generation domestic cat maps, support higher resolution mapping studies, and aid genome assembly in specific areas as well as in the whole genome, a 15,000(Rad) radiation hybrid (RH) panel for the domestic cat was generated. Fibroblasts from the female Abyssinian cat that was used to generate the cat genomic sequence were fused to a Chinese hamster cell line (A23), producing 150 hybrid lines. The clones were initially characterized using 39 short tandem repeats (STRs) and 1,536 SNP markers. The utility of whole-genome amplification in preserving and extending RH panel DNA was also tested using 10 STR markers; no significant difference in retention was observed. The resolution of the 15,000(Rad) RH panel was established by constructing framework maps across 10 different 1-Mb regions on different feline chromosomes. In these regions, 2-point analysis was used to estimate RH distances, which compared favorably with the estimation of physical distances. The study demonstrates that the 15,000(Rad) RH panel constitutes a powerful tool for constructing high-resolution maps, having an average resolution of 40.1 kb per marker across the ten 1-Mb regions. In addition, the RH panel will complement existing genomic resources for the domestic cat, aid in the accurate re-assemblies of the forthcoming cat genomic sequence, and support cross-species genomic comparisons.

P-selectin Expression Tracks Cerebral Atrophy in Mexican-Americans

Background and Purpose: We hypothesized that the P-selectin (SELP) gene, localized to a region on chromosome 1q24, pleiotropically contributes to increased blood pressure and cerebral atrophy. We tested this hypothesis by performing genetic correlation analyses for 13 mRNA gene expression measures from P-selectin and 11 other genes located in 1q24 region and three magnetic resonance imaging derived indices of cerebral integrity. Methods: The subject pool consisted of 369 (219F; aged 28–85, average = 47.1 ± 12.7 years) normally aging, community-dwelling members of large extended Mexican-American families. Genetic correlation analysis decomposed phenotypic correlation coefficients into genetic and environmental components among 13 leukocyte-based mRNA gene expressions and three whole-brain and regional measurements of cerebral integrity: cortical gray matter thickness, fractional anisotropy of cerebral white matter, and the volume of hyperintensive WM lesions. Results: From the 13 gene expressions, significant phenotypic correlations were only found for the P- and L-selectin expression levels. Increases in P-selectin expression levels tracked with decline in cerebral integrity while the opposite trend was observed for L-selectin expression. The correlations for the P-selectin expression were driven by shared genetic factors, while the correlations with L-selectin expression were due to shared environmental effects. Conclusion: This study demonstrated that P-selectin expression shared a significant variance with measurements of cerebral integrity and posits elevated P-selectin expression levels as a potential risk factor of hypertension-related cerebral atrophy.

Genome-wide linkage scan for quantitative trait loci underlying normal variation in heel bone ultrasound measures

Quantitative ultrasound (QUS) traits are correlated with bone mineral density (BMD), but predict risk for future fracture independent of BMD. Only a few studies, however, have sought to identify specific genes influencing calcaneal QUS measures. The aim of this study was to conduct a genome-wide linkage scan to identify quantitative trait loci (QTL) influencing normal variation in QUS traits. QUS measures were collected from a total of 719 individuals (336 males and 383 females) from the Fels Longitudinal Study who have been genotyped and have at least one set of QUS measurements. Participants ranged in age from 18.0 to 96.6 years and were distributed across 110 nuclear and extended families. Using the Sahara ® bone sonometer, broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness index (QUI) were collected from the right heel. Variance components based linkage analysis was performed on the three traits using 400 polymorphic short tandem repeat (STR) markers spaced approximately 10 cM apart across the autosomes to identify QTL influencing the QUS traits. Age, sex, and other significant covariates were simultaneously adjusted. Heritability estimates (h²) for the QUS traits ranged from 0.42 to 0.57. Significant evidence for a QTL influencing BUA was found on chromosome 11p15 near marker D11S902 (LOD = 3.11). Our results provide additional evidence for a QTL on chromosome 11p that harbors a potential candidate gene(s) related to BUA and bone metabolism.

Genome-wide linkage scan for plasma high density lipoprotein cholesterol, apolipoprotein A-1 and triglyceride variation among American Indian populations: the Strong Heart Family Study

BACKGROUND

Recent studies have identified chromosomal regions linked to variation in high density lipoprotein cholesterol (HDL-C), apolipoprotein A-1 (apo A-1) and triglyceride (TG), although results have been inconsistent and previous studies of American Indian populations are limited.

OBJECTIVE

In an attempt to localise quantitative trait loci (QTLs) influencing HDL-C, apo A-1 and TG, we conducted genome-wide linkage scans of subjects of the Strong Heart Family Study.

METHODS

We implemented analyses in 3484 men and women aged 18 years or older, at three study centres.

RESULTS

With adjustment for age, sex and centre, we detected a QTL influencing both HDL-C (logarithm of odds (LOD) = 4.4, genome-wide p = 0.001) and apo A-1 (LOD = 3.2, genome-wide p = 0.020) nearest marker D6S289 at 6p23 in the Arizona sample. Another QTL influencing apo A-1 was found nearest marker D9S287 at 9q22.2 (LOD = 3.0, genome-wide p = 0.033) in the North and South Dakotas. We detected a QTL influencing TG nearest marker D15S153 at 15q22.31 (LOD = 4.5 in the overall sample and LOD = 3.8 in the Dakotas sample, genome-wide p = 0.0044) and when additionally adjusted for waist, current smoking, current alcohol, current oestrogen, lipid treatment, impaired fasting glucose, and diabetes, nearest marker D10S217 at 10q26.2 (LOD = 3.7, genome-wide p = 0.0058) in the Arizona population.

CONCLUSIONS

The replication of QTLs in regions of the genome that harbour well known candidate genes suggest that chromosomes 6p, 9q and 15q warrant further investigation with fine mapping for causative polymorphisms in American Indians.

Genetic influences on bone loss in the San Antonio Family Osteoporosis study

The genetic contribution to age-related bone loss is not well understood. We estimated that genes accounted for 25-45% of variation in 5-year change in bone mineral density in men and women. An autosome-wide linkage scan yielded no significant evidence for chromosomal regions implicated in bone loss.

INTRODUCTION

The contribution of genetics to acquisition of peak bone mass is well documented, but little is known about the influence of genes on subsequent bone loss with age. We therefore measured 5-year change in bone mineral density (BMD) in 300 Mexican Americans (>45 years of age) from the San Antonio Family Osteoporosis Study to identify genetic factors influencing bone loss.

METHODS

Annualized change in BMD was calculated from measurements taken 5.5 years apart. Heritability (h(2)) of BMD change was estimated using variance components methods and autosome-wide linkage analysis was carried out using 460 microsatellite markers at a mean 7.6 cM interval density.

RESULTS

Rate of BMD change was heritable at the forearm (h(2) = 0.31, p = 0.021), hip (h(2) = 0.44, p = 0.017), spine (h(2) = 0.42, p = 0.005), but not whole body (h(2) = 0.18, p = 0.123). Covariates associated with rapid bone loss (advanced age, baseline BMD, female sex, low baseline weight, postmenopausal status, and interim weight loss) accounted for 10% to 28% of trait variation. No significant evidence of linkage was observed at any skeletal site.

CONCLUSIONS

This is one of the first studies to report significant heritability of BMD change for weight-bearing and non-weight-bearing bones in an unselected population and the first linkage scan for change in BMD.

Determinants of variation in human serum paraoxonase activity

Paraoxonase-1 (PON1) is associated with high-density lipoprotein (HDL) particles and is believed to contribute to antiatherogenic properties of HDLs. We assessed the determinants of PON1 activity variation using different substrates of the enzyme. PON1 activity in serum samples from 922 participants in the San Antonio Family Heart Study was assayed using a reliable microplate format with three substrates: paraoxon, phenyl acetate and the lactone dihydrocoumarin. There were major differences among results from the three substrates in degree of effect by various environmental and genetic factors, suggesting that knowledge of one substrate activity alone may not provide a complete sense of PON1 metabolism. Three significant demographic covariates (age, smoking status and contraceptive usage) together explained 1-6% of phenotypic variance, whereas four metabolic covariates representing lipoprotein metabolism (apoAII, apoAI, triglycerides and non-HDL cholesterol) explained 4-19%. Genes explained 65-92% of phenotypic variance and the dominant genetic effect was exerted by a locus mapping at or near the protein structural locus (PON1) on chromosome 7. Additional genes influencing PON1 activity were localized to chromosomes 3 and 14. Our study identified environmental and genetic determinants of PON1 activity that accounted for 88-97% of total phenotypic variance, suggesting that few, if any, major biological determinants are unrepresented in the models.

Quantitative trait locus on chromosome 12q14.1 influences variation in plasma plasminogen levels in the San Antonio Family Heart Study

Plasminogen is a hemostasis-related phenotype and is commonly implicated in thrombotic and bleeding disorders. In the San Antonio Family Heart Study (SAFHS), we performed to our knowledge the first genomewide linkage scan for quantitative trait loci (QTLs) that influence the level of plasminogen. The subset of the SAFHS population used for this study consists of 629 individuals distributed across 26 extended Mexican American families. Pedigree-based variance component linkage analyses were performed using SOLAR. The mean plasminogen level was 114.94% +/- 17.8 (range, 42-195). The heritability (h2) of plasminogen was 0.43 +/- 0.08 (p < 6.3 x 10(-13)). One region on chromosome 12 (12q14.1) showed suggestive evidence of linkage (LOD = 2.73, nominal p < 0.0002, genomewide p = 0.0786) near marker D12S1609. Because plasminogen has important effects in many human health problems, such as cancer and atherosclerosis, the role of this putative QTL in the regulation of plasminogen variability needs to be studied further.

Cross-species replication of a resistin mRNA QTL, but not QTLs for circulating levels of resistin, in human and baboon

Resistin has been associated with inflammation and risk for cardiovascular disease. We previously reported evidence of a QTL on chromosome 19p13 affecting the abundance of resistin (RETN) mRNA in the omental adipose tissue of baboons (L0D score 3.8). In this study, whole genome transcription levels were assessed in human lymphocyte samples from 1240 adults participating in the San Antonio Family Heart Study, using the Sentrix Human-6 Expression Beadchip. Lymphocytes were surveyed, as it has been proposed that their expression levels may reflect those in harder to ascertain tissues, such as adipose tissue, that are thought to be more directly relevant to disease procesn was conducted to detect loci affecting RETN mRNA levels. We obtained significant evidence for a QTL influencing the RETN expression (LOD score 10.7) on chromosome 19p. This region is orthologous/homologous to the region previously localized on baboon chromosome 19. The strongest positional candidate gene in this region is the structural gene for resistin, itself. We also found evidence for a QTL influencing resistin protein levels (LOD score 5.3) on chromosome 14q. This differs from our previously reported QTL on chromosome 18 in baboons. The different QTLs for circulating protein suggests that post-translational processing and turnover may be influenced by different or multiple genes in baboons and humans. The parallel findings of a cis-eQTL for RETN mRNA in baboon omental tissue and human lymphocytes lends support to the strategy of using lymphocyte gene expression levels as a surrogate for gene expression levels in other tissues.

Genome-wide scan revealed genetic loci for energy metabolism in Hispanic children and adolescents

OBJECTIVE

Genome-wide scans were conducted in search for genetic locations linked to energy expenditure and substrate oxidation in children.

DESIGN

Pedigreed data of 1030 Hispanic children and adolescents were from the Viva La Familia Study which was designed to investigate genetic and environmental risk factors for the development of obesity in Hispanic families. A respiratory calorimeter was used to measure 24-h total energy expenditure (TEE), basal metabolic rate (BMR), sleep metabolic rate (SMR), 24-h respiratory quotient (24RQ), basal metabolic respiratory quotient (BMRQ) and sleep respiratory quotient (SRQ). Protein, fat and carbohydrate oxidation (PROOX, FATOX and CHOOX, respectively) were also estimated. All participants were genotyped for 384 single tandem repeat markers spaced an average of 10 cM apart. Computer program SOLAR was used to perform the genetic linkage analyses.

RESULTS

Significant linkage for TEE was detected on chromosome 1 near marker D1S2841, with a logarithm of the odds (LOD) score of 4.0. SMR, BMRQ and PROOX were associated with loci on chromosome 18, 17 and 9, respectively, with LOD scores of 4.88, 3.17 and 4.55, respectively. A genome-wide scan of SMR per kg fat-free mass (SpFFM) peaked in the same region as SMR on chromosome 18 (LOD, 5.24). Suggestive linkage was observed for CHOOX and FATOX. Several candidate genes were found in the above chromosomal regions including leptin receptor (LEPR).

CONCLUSION

Regions on chromosomes 1, 9, 17 and 18 harbor genes affecting variation in energy expenditure and substrate oxidation in Hispanic children and adolescents.

Linkage analysis of circulating levels of adiponectin in Hispanic children

INTRODUCTION

Adiponectin, a hormone produced exclusively by adipose tissue, is inversely associated with insulin resistance and proinflammatory conditions. The aim of this study was to find quantitative trait loci (QTLs) that affect circulating levels of adiponectin in Hispanic children participating in the VIVA LA FAMILIA Study by use of a systematic genome scan.

METHODS

The present study included extended families with at least one overweight child between 4 and 19 years old. Overweight was defined as body mass index (BMI) 95th percentile. Fasting blood was collected from 466 children from 127 families. Adiponectin was assayed by radioimmunoassay (RIA) technique in fasting serum. A genome-wide scan on circulating levels of adiponectin as a quantitative phenotype was conducted using the variance decomposition approach.

RESULTS

The highest logarithm of odds (LOD) score (4.2) was found on chromosome 11q23.2-11q24.2, and a second significant signal (LOD score=3.0) was found on chromosome 8q12.1-8q21.3. In addition, a signal suggestive of linkage (LOD score=2.5) was found between 18q21.3 and 18q22.3. After adjustment for BMI-Z score, the LOD score on chromosome 11 remained unchanged, but the signals on chromosomes 8 and 18 dropped to 1.6 and 1.7, respectively. Two other signals suggestive of linkage were found on chromosome 3 (LOD score=2.1) and 10 (LOD score=2.5). Although the region on chromosome 11 has been associated with obesity and diabetes-related traits in adult populations, this is the first observation of linkage in this region for adiponectin levels. Our suggestive linkages on chromosomes 10 and 3 replicate results for adiponectin seen in other populations. The influence of loci on chromosomes 18 and 8 on circulating adiponectin seemed to be mediated by BMI in the present study.

CONCLUSION

Our genome scan in children has identified a novel QTL and replicated QTLs in chromosomal regions previously shown to be linked with obesity and type 2 diabetes (T2D)-related phenotypes in adults. The genetic contribution of loci to adiponectin levels may vary across different populations and age groups. The strong linkage signal on chromosome 11 is most likely underlain by a gene(s) that may contribute to the high susceptibility of these Hispanic children to obesity and T2D.

Quantitative genetic analysis of blood pressure reactivity to orthostatic tilt using principal components analysis

Blood pressure (BP) reactivity to orthostatic tilt may be predictive of cardiovascular disease. However, the genetic and environmental influences on BP reactivity to tilt have not been well examined. Identifying different influences on BP at rest and BP during tilt is complicated by the intercorrelation among multiple measurements. In this study, we use principal components analysis (PCA) to reduce multivariate BP data into components that are orthogonal. The objective of this study is to characterize and examine the genetic architecture of BP at rest and during head-up tilt (HUT). Specifically, we estimate the heritability of individual BP measures and three principal components (PC) derived from multiple BP measurements during HUT. Additionally, we estimate covariate effects on these traits. The study sample consisted of 444 individuals, distributed across four large families. HUT consisted of 70 degrees head-up table tilting while strapped to a tilt table. BP reactivity (deltaBP) was defined as BP during HUT minus BP while supine. Three PC extracted from the PCA were interpreted as 'general BP' (PC1), 'pulse pressure' (PC2) and 'BP reactivity' (PC3). Variance components methods were used to estimate the heritabilities of resting BP, HUT BP, deltaBP, as well as the three BP PC. Significant (P<0.05) heritabilities were found for all BP measurements, except for systolic deltaBP at 1 and 3 min, and diastolic deltaBP at 2 min. Significant genetic effects were also found for the three PC. Each of these orthogonal components is significantly influenced by somewhat different sets of covariates.

A Locus on Chromosome 13 Influences Levels of TAFI Antigen in Healthy Mexican Americans

When activated, thrombin activatable fibrinolysis inhibitor (TAFI) inhibits fibrinolysis by modifying fibrin, depressing its plasminogen binding potential. Polymorphisms in the TAFI structural gene (CPB2) have been associated with variation in TAFI levels, but the potential occurrence of influential quantitative trait loci (QTLs) located elsewhere in the genome has been explored only in families ascertained in part through probands affected by thrombosis. We report the results of the first genome-wide linkage screen for QTLs that influence TAFI phenotypes. Data are from 635 subjects from 21 randomly ascertained Mexican American families participating in the San Antonio Family Heart Study. Potential QTLs were localized through a genome-wide multipoint linkage scan using 417 highly informative autosomal short tandem repeat markers spaced at approximately 10-cM intervals. We observed a maximum multipoint LOD score of 3.09 on chromosome 13q, the region of the TAFI structural gene. A suggestive linkage signal (LOD = 2.04) also was observed in this region, but may be an artifact. In addition, weak evidence for linkage occurred on chromosomes 17p and 9q. Our results suggest that polymorphisms in the TAFI structural gene or its nearby regulatory elements may contribute strongly to TAFI level variation in the general population, although several genes in other regions of the genome may also influence variation in this phenotype. Our findings support those of the Genetic Analysis of Idiopathic Thrombophilia (GAIT) project, which identified a potential TAFI QTL on chromosome 13q in a genome-wide linkage scan in Spanish thrombophilia families.

Linkage analysis of LDL cholesterol in American Indian populations: the Strong Heart Family Study

Previous studies have demonstrated that low density lipoprotein cholesterol (LDL-C) concentration is influenced by both genes and environment. Although rare genetic variants associated with Mendelian causes of increased LDL-C are known, only one common genetic variant has been identified, the apolipoprotein E gene (APOE). In an attempt to localize quantitative trait loci (QTLs) influencing LDL-C, we conducted a genome-wide linkage scan of LDL-C in participants of the Strong Heart Family Study (SHFS). Nine hundred eighty men and women, age 18 years or older, in 32 extended families at three centers (in Arizona, Oklahoma, and North and South Dakota) were phenotyped for LDL-C concentration and other risk factors. Using a variance component approach and the program SOLAR, and after accounting for the effects of covariates, we detected a QTL influencing LDL-C on chromosome 19, nearest marker D19S888 at 19q13.41 [logarithm of odds (LOD) = 4.3] in the sample from the Dakotas. This region on chromosome 19 includes many possible candidate genes, including the APOE/C1/C4/C2 gene cluster. In follow-up association analyses, no significant evidence for an association was detected with the APOE*2 and APOE*4 alleles (P = 0.76 and P = 0.53, respectively). Suggestive evidence of linkage to LDL-C was detected on chromosomes 3q, 4q, 7p, 9q, 10p, 14q, and 17q. These linkage signals overlap positive findings for lipid-related traits and harbor plausible candidate genes for LDL-C.

Meta-analysis of five genome-wide linkage studies for body mass index reveals significant evidence for linkage to chromosome 8p

OBJECTIVE

To perform a meta-analysis of genome-wide linkage scans using body mass index (BMI) to identify genetic loci predisposing to obesity.

DATA

A total of 13 published genome scans on obesity have used BMI as their primary end point. Five of these 13 groups agreed to provide detailed results from their scans that were required for a meta-analysis. Collectively, these five studies included a total of 2814 individuals from 505 families.

METHODS

The results of the five studies were analysed using the GSMA (genome scans meta-analysis) method.

RESULTS

The analysis revealed significant evidence for linkage of the quantitative phenotype BMI to 8p (P<0.0005).

Genome-wide scan of resistin mRNA expression in omental adipose tissue of baboons

INTRODUCTION

The hormone resistin was recently discovered in adipose tissue of mice. Functional tests suggest a role for resistin in the regulation of insulin sensitivity. However, human studies have reported controversial results on the metabolic function of this hormone.

METHODS

A 1 g omental adipose tissue biopsy was obtained from 404 adult baboons. Resistin mRNA expression was assayed by real-time, quantitative RT-PCR, and univariate and bivariate quantitative genetic analyses were performed, via the variance decomposition approach. A genome scan analysis was conducted using resistin mRNA abundance in omental adipose tissue as a quantitative phenotype.

RESULTS

A significant heritability of h2 = 0.23 (P = 0.003) was found for resistin mRNA abundance in omental adipose tissue. A genome scan detected a quantitative trait locus for resistin expression with an LOD score of 3.8, in the region between markers D19S431 and D19S714, corresponding to human chromosome 19 p13. This chromosomal region contains genes related to insulin resistance phenotypes, such as resistin, insulin receptor, angiopoietin-like 4 protein and LDL receptor.

CONCLUSIONS

Individual variation in resistin mRNA expression has a significant genetic component, and a gene or genes on chromosome 19 p13 may regulate resistin mRNA levels in baboon omental adipose tissue.

Genetics of leptin expression in baboons

OBJECTIVE

Leptin gene expression is higher in females than in males, and is regulated by many factors including energy intake and insulin, but little is known about the inheritance of leptin gene expression. We have investigated leptin (LEP) gene express-ion, to determine whether it is heritable, and whether the difference in LEP expression between males and females has a genetic component.

STUDY POPULATION

A total of 319 baboons (Papio hamadryas) (220 females, 99 males) from a captive, pedigreed colony.

MEASUREMENTS AND METHODS

We cloned a baboon LEP cDNA, and quantified LEP mRNA expression in baboon omental adipose tissue using a ribonuclease protection assay. In addition, we assayed circulating leptin levels, adipocyte cell volume, and weight. We used maximum likelihood-based variance decomposition methods to determine the genetic architecture of LEP levels, including testing for genotype-by-sex interaction.

RESULTS

Omental LEP mRNA expression was significantly and positively correlated with weight and adipocyte cell volume in baboons. Both mRNA and plasma levels of leptin were higher in females than in males, and both measures were heritable. The results of our genetic analysis show that there was a genotype-by-sex interaction in the levels of plasma leptin, but not in omental LEP mRNA.

CONCLUSIONS

As in humans, baboon leptin mRNA and protein levels are expressed at a higher level in females than in males. We detected evidence that the plasma levels were affected by genes that are differentially expressed in males and females, while the omental mRNA levels were not. This finding suggests that the genes that differentially regulate plasma leptin levels between males and females may exert their effects on post-transcriptional processes.

A quantitative trait locus on chromosome 16q influences variation in plasma HDL-C levels in Mexican Americans

OBJECTIVE

We conducted a whole-genome, multipoint linkage screen to localize a previously reported major locus accounting for 56% to 67% of the additive genetic effects on covariate-adjusted plasma HDL cholesterol (HDL-C) levels in Mexican Americans from the San Antonio Family Heart Study (SAFHS).

METHODS AND RESULTS

After using complex segregation analysis to recover the major locus in 472 SAFHS participants from 10 genotyped families, we incorporated covariates required to detect that major locus, including plasma levels of triglycerides and apolipoprotein A-I, in a maximum-likelihood-based variance-components linkage screen. Only chromosome 16 exhibited convincing evidence for a quantitative trait locus (QTL), with a peak multipoint log of the odds (LOD)=3.73 (P=0.000034). Subsequent penetrance model-based linkage analysis, incorporating genotypes at the marker locus nearest the multipoint peak (D16S518) into the segregation model, detected linkage with the previously detected major locus (LOD=2.73, P=0.000642). Initial estimates place this QTL within a 15-cM region of chromosome 16q near the structural loci for lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP).

CONCLUSIONS

A QTL influencing plasma levels of HDL-C in Mexican Americans from San Antonio maps to a region of human chromosome 16q near LCAT and CETP.

Interactions between variants in the beta3-adrenergic receptor and peroxisome proliferator-activated receptor-gamma2 genes and obesity

OBJECTIVE

Previous studies have reported modest associations between measures of obesity and the Trp64-Arg variant of the beta3-adrenergic receptor (ADRbeta3) and the Pro12Ala variant of the peronisome proliferator-activated receptor (PPAR)-gamma2. We hypothesized that these single gene variants may mark mutations that act through convergent pathways to produce synergistic effects on obesity.

RESEARCH DESIGN AND METHODS

The sample included 453 subjects from 10 large Mexican-American families participating in the population-based San Antonio Family Heart Study. The effects of each gene variant singly and jointly were estimated as fixed effects using the measured genotype approach framework. Analyses were conditioned on the pedigree structures to account for the correlations among family members. Statistical significance was evaluated by the likelihood ratio test with adjustment for age, sex and diabetes status.

RESULTS

The allele frequencies for the ADRbeta3 Trp64Arg and PPARgamma2 Pro12Ala variants were 18 and 12%, respectively. The ADRbeta3 variant was not significantly associated with any of the obesity-related traits, but subjects with the PPAR-gamma2 variant (n = 98) had significantly higher levels of lasting insulin (P = 0.03), leptin (P = 0.009), and waist circumference (P = 0.03) than those without. Subjects with the gene variants (n = 32) had significantly higher BMI, insulin, and leprtin levels than those with only the PPARgamma2 variant (n = 66) (P for interaction: 0.04, 0.02, and 0.01 for BMI, fasting insulin, and leptin, respectively).

CONCLUSIONS

Our results suggest that epistatic models with genes that have modest individual effects may be useful in understanding the genetic underpinnings of typical obesity in humans.

Linkage exclusion analysis of the chromosome 11 region containing UCP2 and UCP3 with obesity-related phenotypes in Mexican Americans

OBJECTIVE

To investigate whether the region of chromosome 11 (11q13) containing the genes UCP2 and UCP3 could be excluded for linkage with a variety of obesity-related phenotypes in humans.

DESIGN

Exclusion mapping using a variance component approach in extended pedigrees.

SUBJECTS

Four-hundred and fifty eight individuals (195 females, 263 males) distributed in 10 Mexican American families of probands randomly ascertained with respect to any disease state and who are participating in the San Antonio Family Heart Study. Ages range from 18 to 87 (mean age 35 y).

MEASUREMENTS

Serum leptin levels, fat mass (FM), body mass index (BMI), and waist circumference.

RESULTS

We were able to exclude the chromosomal region containing UCP2/UCP3 as having an effect on this set of obesity-related phenotypes at relative effect sizes of 10% or greater (P-values<0.05).

CONCLUSIONS

These results suggest that variation in these genes is unlikely to have a substantial effect on the expression of obesity-related phenotypes in the Mexican American population.

The Pro12Ala variant of peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) is associated with measures of obesity in Mexican Americans

Peroxisome proliferator-activated receptors (PPAR) are transcription factors that regulate adipocyte differentiation and gene expression. We tested the hypothesis that the Pro12Ala variant of PPAR-gamma2 is associated with obesity and type 2 diabetes-related traits in 921 subjects from the San Antonio Family Heart Study. Subjects with at least one Ala allele (n=210) had significantly higher body mass index (P=0.015) and waist circumference (P=0.028) and significantly higher levels of serum leptin (P= 0.022) than those without the allele. Further studies will determine whether the Pro12Ala variant itself, or other genetic variation at PPAR-gamma, is responsible for this association with measures of obesity in Mexican Americans.

Genes influencing variation in serum osteocalcin concentrations are linked to markers on chromosomes 16q and 20q

Osteocalcin (OC) is an important constituent of bone that is synthesized by osteoblasts. Serum levels of OC have been used as a biochemical marker of bone turnover. To identify the genes influencing variation in serum OC levels, we conducted a genome-wide scan in 429 individuals comprising 10 large multigenerational families. OC levels were measured by immunoassay, and genetic markers were typed at approximately 10-cM intervals across the genome. Quantitative trait linkage was tested using a multipoint analysis based on variance component methodology, adjusting for the effects of age, sex, and oral contraceptive use. Significance levels for linkage were obtained empirically, by Monte Carlo simulation. The heritability of OC levels in this population was 62 +/- 8%. We detected significant evidence for linkage between a quantitative trait locus influencing serum OC levels and markers on chromosome 16q, and suggestive evidence for linkage of OC levels with markers on chromosome 20q. The multipoint lod scores peaked at 3.35 on chromosome 16 and 2.78 on chromosome 20, corresponding to P values of 0.00004 and 0.00017, respectively. A potential candidate gene for bone formation in the linked region on chromosome 20 is CDMP1, which encodes cartilage-derived morphogenetic protein 1. Future studies should evaluate whether variation in CDMP1 or in other genes in the linked regions on chromosomes 16 and 20 influence the rate of bone turnover.

Treatment of advanced Parkinson's disease by unilateral posterior GPi pallidotomy: 4-year results of a pilot study

To assess the long-term outcome following unilateral pallidotomy for advanced Parkinson's disease, we performed nonblinded Core Assessment Program for Intracerebral Transplantations protocol assessments in 10 of the original 15 patients in our pilot study for 4 years following surgery. Although Unified Parkinson's Disease Rating Scale motor examination scores returned to baseline levels at 3 and 4 years, most patients continued to show sustained improvements in contralateral tremor, akinesia, and drug-induced dyskinesias. Contralateral tremor was absent at 4 years in all seven patients with preoperative tremor. Contralateral "off" arm movement times (averaged for three tasks) decreased by 37% at 1 year and by 30% at 4 years. Contralateral dyskinesia scores improved by 82% at 1 year and by 64% at 4 years. In contrast, after reaching speeds equal to the contralateral side at 1 year, ipsilateral "off" movement times increased by 13% over baseline levels at 4 years. Although most gait and postural stability measures showed modest initial improvement followed by a return to baseline values, "on" stand-walk-sit task performance declined significantly at 4 years. Despite the restriction of our surgeries to one side and the expected natural progression of Parkinson's disease, the results of patient self-assessments suggest that 4 years after unilateral pallidotomy, most patients continue to experience a quality of life above preoperative levels.

Linkage of serum insulin concentrations to chromosome 3p in Mexican Americans

Hyperinsulinemia predicts the development of type 2 diabetes, and family studies suggest that insulin levels are regulated in part by genes. We conducted a genome-wide scan to detect genes influencing variation in fasting serum insulin concentrations in 391 nondiabetic individuals from 10 large multigenerational families. Approximately 380 microsatellite markers with an average spacing of 10 cM were genotyped in all study subjects. Insulin concentrations measured by radioimmunoassay were transformed by their natural logarithms before analysis. In multipoint analysis, peak evidence for linkage occurred on chromosome 3p approximately 109 cM from pter in the region of 3p14.2-p14.1. The multipoint logarithm of odds (LOD) score was 3.07, occurring in the region flanked by markers D3S1600 and D3S1285 (P value by simulation <0.0001). In a two-point analysis, LOD scores ranged from 0.75 to 2.52 for the nine markers typed in the region spanning 88-143 cM from pter. The fasting insulin resistance index was highly correlated with fasting insulin concentrations in this sample and also provided strong evidence for linkage to this region (LOD = 2.99). There was no evidence in our genome-wide scan for linkage of insulin levels to any other chromosome. These results provide evidence that a gene-influencing variation in insulin concentrations exists on chromosome 3p. Possible candidate genes in this region include GBE1 and ACOX2, which encode enzymes involved in glycogen and fatty acid metabolism, respectively.

Improving the recognition and management of depression: is there a role for physician education?

BACKGROUND

Many patients who visit primary care physicians suffer from depression, but physicians may miss the diagnosis or undertreat these patients. Improving physicians' communication skills pertaining to diagnosing and managing depression may lead to better outcomes.

METHODS

We performed a randomized controlled trial involving 49 primary care physicians to determine the effect of the Depression Education Program on their knowledge of depression and their behavior toward depressed patients. After randomization, physicians in the intervention group completed the Depression Education Program, which consists of 2 4-hour interactive workshops that combine lectures, discussion, audiotape review, and role-playing. Between sessions, physicians audiotaped an interview with one of their patients. Two to 6 weeks following the intervention program, physicians completed a knowledge test and received office visits from 2 unannounced people acting as standardized patients with major depression. These "patients" completed a checklist and scales. Logistic and linear regression were used to control for sex, specialty, and suspicion that the patient was a standardized patient.

RESULTS

For both standardized patients, more intervention physicians than control physicians asked about stresses at home, and they also scored higher on the Participatory Decision-Making scale. During the office visits of one of the standardized patients, more intervention physicians asked about at least 5 criteria for major depression (82% and 38%, P = .006), discussed the possibility of depression (96% and 65%, P = .049), scheduled a return visit within 2 weeks (67% and 33%, P = .004), and scored higher than control physicians on the Patient Satisfaction scale (40.3 and 35.5, P = .014).

CONCLUSIONS

The Depression Education Program changed physicians' behavior and may be an important component in the efforts to improve the care of depressed patients.

A quantitative trait locus influencing BMI maps to the region of the beta-3 adrenergic receptor

The beta-3 adrenergic receptor (ADRB3) has been implicated as a regulator of energy expenditure, and a polymorphism in codon 64 of this gene (Trp64Arg) has been associated in some studies with obesity and insulin resistance. However, many studies have failed to detect an effect of this variant, and the importance of the Trp64Arg variant in human obesity remains controversial. We performed a quantitative linkage analysis of the ADRB3 and obesity, using 12 markers (including the intragenic Trp64Arg polymorphism) spanning a 57-cM region of chromosome 8. The study population consisted of 470 individuals from 10 large multigenerational families of Mexican-American ancestry residing in San Antonio, TX. In two-point analysis, logarithm of odds (LOD) scores >1.0 were observed for six markers surrounding ADRB3 in a 33-cM region spanned by markers D8S1477 and D8S1136. The multipoint LOD score was 3.21, occurring between markers D8S1121 and ADRB3, approximately 2-3 cM from ADRB3. Adjusting for the presence of the Arg64 allele or excluding from the analysis the 11 individuals homozygous for the Arg64 allele did not reduce the evidence for linkage. A genome scan was conducted at 10 cM map density to detect other loci influencing variation in BMI. Multipoint LOD scores >1.0 were observed in four other regions, including two on chromosome 17, one on chromosome 6q, and one on chromosome 2p. These data suggest that the ADRB3 should continue to be regarded as a strong candidate gene for obesity even though evidence for an effect of the Trp64Arg polymorphism could not be established. It is also possible that a gene closely linked to ADRB3 may influence susceptibility to obesity.

A genome search identifies major quantitative trait loci on human chromosomes 3 and 4 that influence cholesterol concentrations in small LDL particles

Small, dense LDL particles are associated with increased risk of cardiovascular disease. To identify the genes that influence LDL size variation, we performed a genome-wide screen for cholesterol concentrations in 4 LDL size fractions. Samples from 470 members of randomly ascertained families were typed for 331 microsatellite markers spaced at approximately 15 cM intervals. Plasma LDLs were resolved by using nondenaturing gradient gel electrophoresis into 4 fraction sizes (LDL-1, 26.4 to 29.0 nm; LDL-2, 25.5 to 26.4 nm; LDL-3, 24.2 to 25.5 nm; and LDL-4, 21.0 to 24.2 nm) and cholesterol concentrations were estimated by staining with Sudan Black B. Linkage analyses used variance component methods that exploited all of the genotypic and phenotypic information in the large extended pedigrees. In multipoint linkage analyses with quantitative trait loci for the 4 fraction sizes, only LDL-3, a fraction containing small LDL particles, gave peak multipoint log10 odds in favor of linkage (LOD) scores that exceeded 3.0, a nominal criterion for evidence of significant linkage. The highest LOD scores for LDL-3 were found on chromosomes 3 (LOD=4.1), 4 (LOD=4.1), and 6 (LOD=2.9). In oligogenic analyses, the 2-locus LOD score (for chromosomes 3 and 4) increased significantly (P=0.0012) to 6.1, but including the third locus on chromosome 6 did not significantly improve the LOD score (P=0.064). Thus, we have localized 2 major quantitative trait loci that influence variation in cholesterol concentrations of small LDL particles. The 2 quantitative trait loci on chromosomes 3 and 4 are located in regions that contain the genes for apoD and the large subunit of the microsomal triglyceride transfer protein, respectively.

Mental disorders in the primary care sector: a potential role for managed care

This activity is designed for leaders and managers of managed care organizations and for primary care physicians involved in evaluating, treating, and caring for patients with mental disorders.

GOAL

To provide a better understanding of primary care patients' needs for mental health services and how managed care companies might best address these needs.

OBJECTIVES

1. Describe problems in detection of mental disorders 2. Discuss the specific ways in which treatments can be improved for mental disorders under managed care systems.

Recent polymorphic insertion of an Alu repeat in the baboon lipoprotein lipase (LPL) gene

We have identified a polymorphic insertion in the lipoprotein lipase (LPL) gene in a captive baboon colony. Mapping and nucleotide (nt) sequence analysis of the polymorphism showed that it is due to the presence or absence of an Alu repetitive element in intron 7 of the baboon LPL gene. This polymorphic Alu repeat has not been reported in humans, and we did not detect the repeat in a survey of the LPL intron 7 gene region in other non-human primates. Comparison of nt at diagnostic positions in this Alu insertion with different Alu subfamily consensus sequences showed that it most closely resembles the young AluY subfamily. These data suggest that this polymorphic Alu repeat inserted independently in the baboon lineage.

Reducing malpractice risk through more effective communication

This activity is designed for physicians, health plan administrators, and other providers.

GOAL

To help physicians, health plan administrators, and other providers learn more about the relationship between provider communication behaviors and subsequent negligence litigation and learn how to reduce malpractice risk through improving communication behaviors.

OBJECTIVES

1. To describe research findings concerning the relationship between provider communication behaviors and subsequent claims of negligence. 2. To describe the major interviewing deficiencies that have been identified as precipitants of malpractice litigation. 3. To describe three functions of effective interviewing. 4. To describe training and learning methods that can improve provider-patient relationships, leading to improved clinical outcomes and decreased malpractice risk.

Treatment of advanced Parkinson's disease by posterior GPi pallidotomy: 1-year results of a pilot study

The effects of posterior internal pallidal ablation (GPi pallidotomy) on parkinsonian signs and symptoms were studied in 15 patients with medically intractable Parkinson's disease (PD). The sensorimotor territory of the internal portion of the globus pallidus and the adjacent optic tract and internal capsule were identified with microelectrode recording and stimulation. Radiofrequency lesions were then created in the identified sensorimotor territory. Pallidotomy significantly improved all cardinal parkinsonian motor signs (tremor, rigidity, akinesia/bradykinesia, and gait dysfunction) and reduced drug-induced motor fluctuations and dyskinesias. The improvements occurred predominately contralateral to the lesion, but were also present ipsilaterally. Early postoperative (3-month), mean total United Parkinson's Disease Rating Scale scores improved by 30.1% from preoperative values. Mean combined "on/off" Schwab and England Scale scores, a measure of functional independence, increased from 48.8% to 73.0% postoperatively. The mean total United Parkinson's Disease Rating Scale and Schwab and England scores did not show a statistically significant decline over the 1-year postoperative period. Surgery resulted in little morbidity, including a lack of significant deficits on neuropsychological and psychiatric testing. Physical and social functioning and vitality measures on the Medical Outcome Scale also showed significant improvement over the postoperative period. The findings of this pilot study demonstrate that ablation of the sensorimotor portion of the internal pallidum is a highly effective treatment for advanced PD, with benefits sustained at 1 year.

Psychiatric training in medicine residencies: current needs, practices, and satisfaction

The purpose of this study was to determine the current level of psychiatric training in internal medicine residencies, satisfaction with this training, and perceived need, if any, for more training. Surveys were mailed to all training directors of accredited primary care (N = 178) and categorical (N = 410) internal medicine residencies in the United States; 110 primary care (62%) and 238 categorical (58%) training directors returned the surveys. Seventy-five percent of categorical and 66% of primary care training directors thought their program should spend more time on psychiatric disorders. For all categories of psychiatric disorder, training intensity was greater and satisfaction with training higher in the primary care programs, but less than half of the directors were satisfied with their current level of training, e.g., 33% of categorical and 47% of primary care directors were satisfied with their residents training concerning depression. Training in somatoform disorders, psychotropic drugs, and office psychotherapy were most frequently identified as deficient. The most favored additions to the curriculum were psychiatric consultants in medical clinics and on medical wards. Although most outpatient care for psychiatric disorders is given by primary care physicians, internal medicine training directors perceive current levels of training in their residencies as inadequate. Innovative collaborations between medicine and psychiatry departments will be necessary if treatment of psychiatric disorders in primary care is to be improved.

Depression and disability in Parkinson's disease

The relationship between depression and disability in idiopathic Parkinson's disease (PD) was examined in 31 outpatients. Thirteen percent had current major depression (MD), 10% dysthymia, and 32% a lifetime history of MD. Depression was significantly related to both illness severity and functional impairment. Male patients with early-onset PD (before age 55) had more mood and anxiety disorders than late-onset male patients. Patients with right-sided PD had significantly more depressive symptoms than those with left-sided PD. On multiple regression analyses, depression predicted impaired social, role, and physical functioning for men (but not for women), independent of the impact of illness severity. The results suggest that treatment of depression may improve function; however, findings of gender differences will require replication.

Consultation-liaison psychiatry fellowship in primary care

OBJECTIVE

This article describes the need for and development of an outpatient primary care psychiatry fellowship program.

METHOD

The Department of Psychiatry at Hillside Hospital established a primary care fellowship for psychiatrists in 1994, through its consultation-liaison (C-L) service. Staff alliances established by the C-L service with primary care physicians provided the basis for identifying appropriate outpatient practices in the community. Knowledge and skills objectives were adapted from a traditional C-L fellowship to outpatient primary care medicine.

RESULTS

The selection of a psychologically minded primary care practitioners was crucial. Practitioners used an inclusive model in which fellows would see all patients with them, not just those with mental disorders. Fellows have felt comfortable working in the primary care setting and have been well received by practitioners, staff, and patients. The practitioners were clearly more interested in psychosocial aspects of their patient than were primary care residents.

CONCLUSIONS

The gap in preparing U.S. psychiatrists to function in integrated primary care programs requires establishing a presence in the primary care setting. Skills and relationships from traditional C-L settings can be productively used to accomplish this goal.

Baboon lipoprotein lipase: cDNA sequence and variable tissue-specific expression of two transcripts

We have isolated two lipoprotein lipase (LPL)-encoding cDNA (LPL) clones from a baboon cardiac cDNA library, one of which spans a region from nucleotide (nt) 705 of the coding sequence to the poly(A) tail (2.8 kb). We used reverse transcription followed by PCR (RT-PCR), and anchor-ligated rapid amplification of cDNA ends (RACE) to amplify the remaining 5' region of the LPL transcript. Sequence comparisons reveal that the baboon nt sequence is 95% identical to the human cDNA sequence (ranging from 97.5 to 92.7% in the coding and noncoding regions, respectively). Less than 2% of nt substitutions cause changes between baboon and human amino acid (aa) sequences. The aa in the catalytic triad residues, the heparin-binding site in exon 6, as well as aa in positions where missense mutations cause LPL deficiency, are identical in baboons and humans. Characterization of the tissue-specific expression of LPL using Northern blots of total RNA showed that spinal cord expressed the most LPL transcripts of all baboon tissues examined. Like humans, baboons have two transcript sizes of approx. 3.6 and 3.4 kb in most tissues that express LPL, and sequencing of the 3' untranslated region (UTR) shows this is due to two polyadenylation sites. In contrast, only the larger 3.6-kb transcript is detected in RNA isolated from central nervous system (CNS) tissues. We used RT-PCR to show that the polyadenylation signal that produces the 3.4-kb message is present in CNS LPL transcripts, but is not utilized.

Behavioral disorders: an unrecognized epidemic with implications for providers

It is reported that behavioral and mood-related problems are associated with more than 25% of medical visits. Many patients seeking help are misdiagnosed or not effectively treated by their physicians. We believe that medical education has not prepared primary care providers to evaluate and treat behavioral problems. The traditional medical or biological model needs to be replaced by a more integrated and comprehensive biopsychosocial approach. HMO delivery systems should take the lead in developing this new framework for care.

A model curriculum for mental disorders and behavioral problems in primary care

Changes in the health care delivery system will increasingly emphasize the role of the primary care physician in diagnosing and treating mental disorders and behavioral problems. This increasing emphasis points to the need for more systematic definition of the knowledge and skills that future primary care physicians will need for effective delivery of mental health services. The model curriculum described in this paper represents the efforts of a multidisciplinary Task Force to describe basic training objectives for the psychiatric education of future primary care physicians.