The Effects of Policy-Driven Air Quality Improvements on Children's Respiratory Health.

INTRODUCTION: Ambient air pollution causes substantial morbidity and mortality in the United States and worldwide. To reduce this burden of adverse health effects, a broad array of strategies to reduce ambient air pollution has been developed and applied over past decades to achieve substantial reductions in ambient air pollution levels. This has been especially true in California, where the improvement of air quality has been a major focus for more than 50 years. Direct links between regulatory policies, changes in ambient pollutant concentrations, and improvements in public health have not been extensively documented. Data from the Children's Health Study (CHS), a multiyear study of children's respiratory health development, offered a unique opportunity to evaluate the effects of long-term reductions in air pollution on children's health. METHODS: We assessed whether changes in ambient air quality and emissions were reflected in three important indices of children's respiratory health: lung-function growth, lung-function level, and bronchitic symptoms. To make the best use of available data, these analyses were performed across the longest chronological period and largest CHS population available for the respective lung-function or bronchitic symptoms data sets. During field study operations over the course of the CHS, children's health status was documented annually by testing lung-function performance and the completion of standardized questionnaires covering a broad range of respiratory symptoms. Air quality data for the periods of interest were obtained from community monitoring stations, which operated in collaboration with regional air monitoring networks over the 20-year study time frame. Over the 20-year sampling period, common protocols were applied to collect data across the three cohorts of children. Each cohort's data set was assessed to investigate the relationship between temporal changes in lung-function development, prevalence of bronchitic symptoms, and ambient air pollution concentrations during a similar, vulnerable adolescent growth period (age 11 to 15 years). Analyses were performed separately for particulate matter ≤10 µm in aerodynamic diameter (PM10), particulate matter ≤2.5 µm in aerodynamic diameter (PM2.5), ozone (O3), and nitrogen dioxide (NO2). Emissions data and regulatory policies were collected from the staff of state and regional regulatory agencies, modeling estimates, and archived reports. RESULTS: Emissions in the regions of California studied during the 20-year period decreased by 54% for oxides of nitrogen (NOₓ), 65% for reactive organic gases (ROG), 21% for PM2.5, and 15% for PM10. These reductions occurred despite a concurrent 22% increase in population and a 38% increase in motor vehicle miles driven during that time frame. Air quality improved over the same time frame, with reductions in NO2 and PM2.5 in virtually all of the CHS communities. Annual average NO2 decreased by about 53% (from ~41 to 19 ppb) in the highest NO2-reporting community (Upland) and by about 28% (from ~10 to 7 ppb) in one of the lowest NO2-reporting communities (Santa Maria). Reductions in annual average PM2.5 concentrations ranged from 54% (~33 to 15 µg/m³) in the community with the highest concentration (Mira Loma) to 13% (~9 to 8 µg/m³) in a community with one of the lowest concentrations (Santa Maria). Improvements in PM10 and O3 (measured during eight daytime hours, 10 AM to 6 PM) were most evident in the CHS communities that initially had the highest levels of PM and O3. Trends in annual average NO2, PM2.5, and PM10 ambient air concentrations in the communities with higher-pollution levels were generally consistent with observed trends in NOₓ, ROG, PM2.5, and PM10 emissions.Significant improvements in lung-function growth in progressive cohorts were observed as air quality improved over the study period. Improvements in four-year growth of both forced expiratory volume in the first second of exhalation (FEV1) and forced vital capacity (FVC) were associated with declining levels of NO2 (P < 0.0001), PM2.5 (P < 0.01), and PM10 (P < 0.001). These associations persisted after adjustment for important potential confounders. Further, significant improvements in lung-function growth were observed in both boys and girls and among asthmatic and non-asthmatic children. Within-community decreases in O3 exposure were not significantly associated with lung-function growth. The proportion of children with clinically low FEV1 (defined as <80% predicted) at age 15 declined significantly, from 7.9% to 3.6% across the study periods, respectively, as the air quality improved (P < 0.005). We found little evidence to suggest that improvements in lung-function development were attributable to temporal confounding.Reductions in outdoor levels of NO2, O3, PM10, and PM2.5 across the cohort years of participation were associated with significant reductions in the prevalence of bronchitic symptoms regardless of asthma status, but observed improvements were larger in children with asthma. Among asthmatic children, the reductions in prevalence of bronchitic symptoms at age 10 were 21% (P < 0.01) for NO2, 34% (P < 0.01) for O3, 39% (P < 0.01) for PM10, and 32% (P < 0.01) for PM2.5 for reductions of 4.9 ppb, 3.6 ppb, 5.8 µg/m³, and 6.8 µg/m³, respectively. Similar reductions in prevalence of bronchitic symptoms were observed at age 15 among these same asthmatic children. As in the lung-function analyses, we found little evidence that temporal confounding accounted for the observed associations of symptoms reduction with air quality improvement.The large number and breadth of regulatory activities, as well as the prolonged phase-in periods of several policy approaches to reduce emissions, precluded the close temporal linkage of specific policies with specific changes in health status. However, the combination of policies addressing motor vehicle emissions - from on-board diagnostics to emission controls, from low-sulfur fuels to vehicle smog-check recertification, and from re-formulated gasoline to the various strategies contained within the San Pedro Bay Ports Clean Air Plan (especially the Clean Truck Program) - all contributed to an impressive and substantial reduction in emissions. These reductions collectively improved local and regional air quality, and improvements in local and regional air quality were associated with improvements in respiratory health. CONCLUSIONS: This study provides evidence that multiyear improvements in air quality and emissions, primarily driven through a broad array of science-based regulatory policy initiatives, have resulted in improved public health outcomes. Our study demonstrates that improvements in air quality, brought about by science-based regulatory actions, are associated with improved respiratory health in children. These respiratory health metrics include reductions in respiratory symptoms and improvements in lung-function development in a population widely accepted to be at risk and highly vulnerable to the effects of air pollution. Our research findings underscore the importance of sustained air regulatory efforts as an effective means of achieving improved respiratory health in communities and regions affected by airborne pollution.

Using routinely collected growth data to assess a school-based obesity prevention strategy.

BACKGROUND: Studies of school-based anti-obesity interventions have yielded inconsistent results. Using growth screening data from a school administrative database, we re-evaluated an obesity prevention strategy that was previously reported to have a beneficial effect on weight status of a sample of students in grades 5-7. METHODS: Ten K-8 schools (five control and five intervention) participated in a 2-year cluster-randomized trial of a multi-component nutrition education intervention. We obtained student height and weight data for 6 consecutive school years and imputed missing baseline and follow-up measurements (53% and 55%, respectively) and defined the target population based on the intent-to-treat principle. We analyzed changes in body mass index (BMI) Z-scores via mixed-effects linear regression and in the prevalence of overweight/obesity via conditional logistic regression. We also assessed incidence and remission of overweight/obesity and long-term effects. RESULTS: We analyzed data for 8186 (96%) K-8 students in the 10 schools (4511 in intervention; 3675 in control). From baseline to the end of the intervention period, mean increases in BMI Z-score were 0.10 and 0.09 in the control and intervention groups, respectively (P=0.671). The prevalence of overweight/obesity increased by 3% in both groups (P=0.926). There was no significant intervention effect on the incidence or remission of overweight/obesity. Among 5469 students who attended study schools during both years of the intervention, there was no significant intervention effect. Furthermore, there was no long-term effect among students with up to 2 years of data beyond the end of the intervention. CONCLUSION: Using routinely collected data for the entire target population, we failed to confirm earlier findings of an intervention effect observed in a subset of students in grades 5-7. Volunteer bias in the prior evaluation and/or measurement error in the routinely collected data are potential reasons for the discrepant findings.

The effect of ambient air pollution on exhaled nitric oxide in the Children's Health Study.

We assessed the effect of daily variations in ambient air pollutants on exhaled nitric oxide fraction (F(eNO)) using data from a cohort of school children with large differences in air pollutant exposures from the Children's Health Study. Based on a cohort of 2,240 school children from 13 Southern Californian communities, cumulative lagged average regression models were fitted to determine the association between F(eNO) and ambient air pollution levels from central site monitors with lags of up to 30 days prior to F(eNO) testing. Daily 24-h cumulative lagged averages of particles with a 50% cut-off aerodynamic diameter of 2.5 µm (PM2.5; over 1-8 days) and particles with a 50% cut-off aerodynamic diameter of 10 µm (PM10; over 1-7 days), as well as 10:00-18:00 h cumulative lagged average of O3 (over 1-23 days) were significantly associated with 17.42% (p<0.01), 9.25% (p<0.05) and 14.25% (p<0.01) higher F(eNO) levels over the interquartile range of 7.5 µg·m⁻³, 12.97 µg·m⁻³ and 15.42 ppb, respectively. The effects of PM2.5, PM10 and O3 were higher in the warm season. The particulate matter effects were robust to adjustments for effects of O3 and temperature and did not vary by asthma or allergy status. In summary, short-term increases in PM2.5, PM10 and O3 were associated with airway inflammation independent of asthma and allergy status, with PM10 effects significantly higher in the warm season.

Exhaled nitric oxide, susceptibility and new-onset asthma in the Children's Health Study.

A substantial body of evidence suggests an aetiological role of inflammation, and oxidative and nitrosative stress in asthma pathogenesis. Exhaled nitric oxide fraction (F(eNO)) may provide a noninvasive marker of oxidative and nitrosative stress, and aspects of airway inflammation. We examined whether children with elevated F(eNO) are at increased risk for new-onset asthma. We prospectively followed 2,206 asthma-free children (age 7-10 yrs) who participated in the Children's Health Study. We measured F(eNO) and followed these children for 3 yrs to ascertain incident asthma cases. Cox proportional hazard models were fitted to examine the association between F(eNO) and new-onset asthma. We found that F(eNO) was associated with increased risk of new-onset asthma. Children in the highest F(eNO) quartile had more than a two-fold increased risk of new-onset asthma compared to those with the lowest quartile (hazard ratio 2.1, 95% CI 1.3-3.5). This effect did not vary with the child's history of respiratory allergic symptoms. However, the effect of elevated F(eNO) on new-onset asthma was most apparent among those without a parental history of asthma. Our results indicate that children with elevated F(eNO) are at increased risk for new-onset asthma, especially if they have no parental history of asthma.

Genetic variations in nitric oxide synthase and arginase influence exhaled nitric oxide levels in children.

BACKGROUND: Exhaled nitric oxide (FeNO) is a biomarker of airway inflammation. In the nitric oxide (NO) synthesis pathway, nitric oxide synthases (encoded by NOS1, NOS2A, and NOS3) and arginases (encoded by ARG1 and ARG2) compete for L-arginine. Although FeNO levels are higher in children with asthma/allergy, influence of these conditions on the relationships between variations in these genes and FeNO remains unknown. The aims of the study were to evaluate the role of genetic variations in nitric oxide synthases and arginases on FeNO in children and to assess the influence of asthma and respiratory allergy on these genetic associations. METHODS: Among children (6-11 years) who participated in the southern California Children's Health Study, variations in these five genetic loci were characterized by tagSNPs. FeNO was measured in two consecutive years (N = 2298 and 2515 in Years 1 and 2, respectively). Repeated measures analysis of variance was used to evaluate the associations between these genetic variants and FeNO. RESULTS: Sequence variations in the NOS2A and ARG2 loci were globally associated with FeNO (P = 0.0002 and 0.01, respectively). The ARG2 association was tagged by intronic variant rs3742879 with stronger association with FeNO in asthmatic children (P-interaction = 0.01). The association of a NOS2A promoter haplotype with FeNO varied significantly by rs3742879 genotypes and by asthma. CONCLUSION: Variants in the NO synthesis pathway genes jointly contribute to differences in FeNO concentrations. Some of these genetic influences were stronger in children with asthma. Further studies are required to confirm our findings.

Rare structural variants found in attention-deficit hyperactivity disorder are preferentially associated with neurodevelopmental genes.

Attention-deficit/hyperactivity disorder (ADHD) is a common and highly heritable disorder, but specific genetic factors underlying risk remain elusive. To assess the role of structural variation in ADHD, we identified 222 inherited copy number variations (CNVs) within 335 ADHD patients and their parents that were not detected in 2026 unrelated healthy individuals. Although no excess CNVs, either deletions or duplications, were found in the ADHD cohort relative to controls, the inherited rare CNV-associated gene set was significantly enriched for genes reported as candidates in studies of autism, schizophrenia and Tourette syndrome, including A2BP1, AUTS2, CNTNAP2 and IMMP2L. The ADHD CNV gene set was also significantly enriched for genes known to be important for psychological and neurological functions, including learning, behavior, synaptic transmission and central nervous system development. Four independent deletions were located within the protein tyrosine phosphatase gene, PTPRD, recently implicated as a candidate gene for restless legs syndrome, which frequently presents with ADHD. A deletion within the glutamate receptor gene, GRM5, was found in an affected parent and all three affected offspring whose ADHD phenotypes closely resembled those of the GRM5 null mouse. Together, these results suggest that rare inherited structural variations play an important role in ADHD development and indicate a set of putative candidate genes for further study in the etiology of ADHD.

Hemoglobin I mutation encoded at both alpha-globin loci on the same chromosome: concerted evolution in the human genome.

Genetic analysis of an individual expressing an unexpectedly high level of hemoglobin I, an alpha-globin structural mutant, reveals that the mutation is present at both the alpha 1- and the alpha 2-globin gene loci. Kindred analysis confirms that the two affected genes are located in cis. The most likely explanation for this finding is that a recent conversion event occurred within the human alpha-globin gene cluster.

MLPA: a rapid, reliable, and sensitive method for detection and analysis of abnormalities of 22q.

In this study, essential test characteristics of the recently described multiplex ligation-dependent probe amplification (MLPA) method are presented, using chromosome 22 as a model. This novel method allows the relative quantification of approximately 40-45 different target DNA sequences in a single reaction. For the purpose of this study, MLPA was performed in a blinded manner on a training set containing over 50 samples, including typical 22q11.2 deletions, various atypical deletions, duplications (trisomy and tetrasomy), and unbalanced translocations. All samples in the training set have been previously characterized by fluorescence in situ hybridization (FISH) with cosmid or BAC clones and/or cytogenetic studies. MLPA findings were consistent with cytogenetic and FISH studies, no rearrangement went undetected and repeated tests gave consistent results. At a relative change in comparative signal strength of 30% or more, sensitivity and specificity values were 0.95 and 0.99, respectively. Given that MLPA is likely to be used as an initial screening method, a higher sensitivity, at the cost of a lower specificity, was deemed more appropriate. A receiver operator characteristic (ROC) curve analysis was performed to calculate the most optimal threshold range, with associated sensitivity and specificity values of 0.99 and 0.97, respectively. Finally, performance of each individual probe was analyzed, providing further useful information for the interpretation of MLPA results. In conclusion, MLPA has proven to be a highly sensitive and accurate tool for detecting copy number changes in the 22q11.2 region, making it a fast and economic alternative to currently used methods. The current study provides valuable and detailed information on the characteristics of this novel method.

Childhood leukemia and parents' occupational and home exposures.

A case-control study of children of ages 10 years and under in Los Angeles County was conducted to investigate the causes of leukemia. The mothers and fathers of acute leukemia cases and their individually matched controls were interviewed regarding specific occupational and home exposures as well as other potential risk factors associated with leukemia. Analysis of the information from the 123 matched pairs showed an increased risk of leukemia for children whose fathers had occupational exposure after the birth of the child to chlorinated solvents [odds ratio (OR) = 3.5, P = .01], spray paint (OR = 2.0, P = .02), dyes or pigments (OR = 4.5, P = .03), methyl ethyl ketone (CAS: 78-93-3; OR = 3.0, P = .05), and cutting oil (OR = 1.7, P = .05) or whose fathers were exposed during the mother's pregnancy with the child to spray paint (OR = 2.2, P = .03). For all of these, the risk associated with frequent use was greater than for infrequent use. There was an increased risk of leukemia for the child if the father worked in industries manufacturing transportation equipment (mostly aircraft) (OR = 2.5, P = .03) or machinery (OR = 3.0, P = .02). An increased risk was found for children whose parents used pesticides in the home (OR = 3.8, P = .004) or garden (OR = 6.5, P = .007) or who burned incense in the home (OR = 2.7, P = .007). The risk was greater for frequent use. Risk of leukemia was related to mothers' employment in personal service industries (OR = 2.7, P = .04) but not to specified occupational exposures. Risk related to fathers' exposure to chlorinated solvents, employment in the transportation equipment-manufacturing industry, and parents' exposure to household or garden pesticides and incense remains statistically significant after adjusting for the other significant findings.

Potential role for wild-type p53 in leukemias with MLL gene translocations.

We used single-strand conformation polymorphism (SSCP) analysis of p53 exons 4-8 to screen for possible mutations in 25 pediatric de novo leukemias with translocations of the MLL gene at chromosome band 11q23. Of the 25 patients, 21 were infants. Fifteen cases were acute myeloid leukemia (AML), eight were acute lymphoblastic leukemia (ALL), and two cases were biphenotypic. Nineteen cases were studied at diagnosis and six at time of relapse. p53 mutations were absent in all 19 cases studied at the time of diagnosis. The only mutation was a TGC-->TTC transversion (cys-->phe) at codon 141 in exon 5 in a case of infant ALL at relapse that occurred by subclone evolution after MLL gene translocation. We previously showed that p53 mutations are also absent in pediatric treatment-related leukemias with MLL gene translocations. The absence of p53 mutations at initial transformation may suggest that the anti-apoptotic effect of mutant p53 is not important in leukemias with MLL gene translocations. Alternatively, exogenous DNA damage may be the common feature in treatment-related and de novo cases. Since MLL gene translocations may occur through DNA repair and wild-type p53 is central to DNA repair, the absence of p53 mutations raises the possibility that wild-type p53, not mutant p53, may be important in the genesis of leukemias with these translocations.

High plasma norepinephrine concentrations at birth in infants of diabetic mothers.

Analysis of plasma norepinephrine (NE) concentrations in umbilical artery and vein from infants of diabetic and nondiabetic mothers revealed high plasma NE values in those of diabetic mothers. While birth weight and arterial plasma NE did not correlate in infants of nondiabetic mothers (r = 0.07, NS), birth weight and plasma NE were related inversely in infants of diabetic mothers (r = -0.73, P less than 0.05).

Differential expression of Fc gamma RIIA, Fc gamma RIIB and Fc gamma RIIC in hematopoietic cells: analysis of transcripts.

Fc gamma receptors (Fc gamma R) are glycoproteins that function in the immune response through their ability to bind the Fc portion of immunoglobulin G. Of the three human Fc gamma R classes, Fc gamma RII is most widely distributed among hematopoietic cells and is the only Fc gamma R class present on platelets and megakaryocytes. There are three different genes coding for Fc gamma RII: Fc gamma RIIA, Fc gamma RIIB and Fc gamma RIIC. Alternative splicing of at least two of these genes results in the production of multiple transcripts. Combining Northern blot analysis with reverse transcription-PCR, we analyzed steady state levels of Fc gamma RII mRNA in the megakaryocytic, myeloid and lymphoid lineages. We determined that megakaryocytic cells predominantly contain Fc gamma RIIA mRNA; Fc gamma RIIA transcripts with and without the transmembrane exon (Fc gamma RIIa1 and Fc gamma RIIa2, respectively) are present in comparable amounts. In contrast, B lymphocytes do not express Fc gamma RIIA mRNAs, but do contain both Fc gamma RIIB transcripts, Fc gamma RIIb1 and Fc gamma RIIb2, as well as the Fc gamma RIIC transcript, Fc gamma RIIc. Myelomonocytic cells contain mRNAs from all three Fc gamma RII genes, predominantly the Fc gamma RIIa1 transcript, both Fc gamma RIIb1 and Fc gamma RIIb2 transcripts and Fc gamma RIIc. Lineage-specific expression of the Fc gamma RII genes implies both differential regulation of expression and differential function in diverse cells.

Characterization of the 5'-flanking transcriptional regulatory region of the human Fc gamma receptor gene, Fc gamma RIIA.

The human Fc gamma receptor gene Fc gamma RIIA is expressed in platelets, neutrophils, monocytes and macrophages. Understanding the regulation of expression of Fc gamma RIIA will enhance our knowledge of regulated gene expression and immune function in these cells. We cloned a 3.65 kb region of the 5' end of the Fc gamma RIIA gene and characterized 3.4 kb of previously unreported sequence of the 5'-flanking region. Primer extension studies and RNase protection analyses of mRNA from HEL, K562 and U937 cells revealed multiple transcription start sites. One transcription start site mapped to a 5'-untranslated (5'UT) exon approximately 1 kb 5' to the ATG translation initiation codon, while a second start site mapped near the ATG codon. Reverse transcription combined with PCR (RT-PCR) employing an oligonucleotide in the putative 5'UT exon and an antisense oligonucleotide in the translated region yielded products which confirm that transcription starts in this 5'UT exon 881 bp upstream of the ATG codon. Sequence analysis of the RT-PCR products showed two related RNA splice products which use alternative 3'-consensus AG splice acceptor sites. Fc gamma RIIA mRNA thus has three distinct potential 5'UT regions, two alternatively spliced forms from the start site in the 5'UT exon and the third from the start site near the ATG codon. Comparisons of the human Fc gamma RIIA 5'-flanking region with human Fc gamma RI and mouse Fc gamma RII beta genes as well as with other genes expressed in megakaryocytes, neutrophils and monocytes reveal structural similarities and shared promoter elements.

Once- and twice-daily dosing with rosiglitazone improves glycemic control in patients with type 2 diabetes.

OBJECTIVE: To determine the efficacy of rosiglitazone compared with placebo in reducing hyperglycemia. RESEARCH DESIGN AND METHODS: After a 4-week placebo run-in period, 959 patients were randomized to placebo or rosiglitazone (total daily dose 4 or 8 mg) for 26 weeks. The primary measure of efficacy was change in the HbA1c concentration. RESULTS: Rosiglitazone produced dosage-dependent reductions in HbA1c of 0.8, 0.9, 1.1, and 1.5% in the 4 mg o.d., 2 mg b.i.d., 8 mg o.d., and 4 mg b.i.d. groups, respectively, compared with placebo. Clinically significant decreases from baseline in HbA1c were observed in drug-naive patients at all rosiglitazone doses and in patients previously treated with oral monotherapy at rosiglitazone 8 mg o.d. and 4 mg b.i.d. Clinically significant decreases from baseline in HbA1c were also observed with rosiglitazone 4 mg b.i.d. in patients previously treated with combination oral therapy. Approximately 33% of drug-naive patients treated with rosiglitazone achieved HbA1c < or =7% at study end. The proportions of patients with at least one adverse event were comparable among the rosiglitazone and placebo groups. There was no evidence of hepatotoxicity in any treatment group. There were statistically significant increases in weight and serum lipids in all rosiglitazone treatment groups compared with placebo. For LDL and HDL cholesterol, the observed increase appeared to be dose related. CONCLUSIONS: Rosiglitazone at total daily doses of 4 and 8 mg significantly improved glycemic control in patients with type 2 diabetes and was well tolerated.

A soluble form of the human Fc receptor Fc gamma RIIA: cloning, transcript analysis and detection.

The Fc gamma receptors (Fc gamma R) are glycoproteins that bind the Fc region of immunoglobulin G. Human hematopoietic cells express three biochemically distinct classes of Fc gamma receptors: Fc gamma RI (CD64), Fc gamma RII (CD32) and Fc gamma RIII (CD16). Complementary DNA (cDNA) clones for each of the human Fc gamma receptors have been isolated from myeloid and lymphoid cells. We describe the isolation and characterization of four Fc gamma RII clones from a cDNA library obtained from a megakaryocyte-like cell line, human erythroleukemia (HEL). Three clones encode the Fc gamma RIIA transmembrane (TM) form, while one novel clone lacks the TM region but retains the cytoplasmic domain. By conducting reverse transcription coupled to polymerase chain reaction (PCR), we found transcripts coding for this unique form of receptor in RNA from platelets, HEL cells and a second megakaryocyte-like cell line, CHRF-288-11. These results were confirmed by RNase protection analysis of RNA from HEL cells. The structure of the novel cDNA suggested that it codes for a soluble form of Fc gamma RIIA. A soluble Fc gamma RII protein was detected in the conditioned medium from HEL cells but not from the Fc gamma RII-negative T cell line, Jurkat, by immunoprecipitation with the anti-Fc gamma RII monoclonal antibody (mAb), IV.3. The immunoprecipitated protein was of the expected size for a soluble Fc gamma RII lacking the TM region but retaining the cytoplasmic domain. Soluble Fc gamma RIIA may be important in modulating the interaction between immune complexes and membrane-associated Fc gamma RII.

Effects of 2-deoxy-D-glucose on the cardiac sympathetic nerves and the adrenal medulla in the rat: further evidence for a dissociation of sympathetic nervous system and adrenal medullary responses.

In rats and mice, fasting suppresses and sucrose overfeeding stimulates sympathetic nervous system (SNS) activity. Fasting hypoglycemia in rats suppresses SNS activity while stimulating adrenal medullary catecholamine release. Administration of 2-deoxy-D-glucose (2-DG), an inhibitor of intracellular glucose metabolism, also stimulates the adrenal medulla. The studies reported here were undertaken to determine the SNS response to chronic 2-DG administration and to test the hypothesis that diet-induced changes in SNS activity are related to central nervous system glucose metabolism. Ingestion of 2-DG caused an increase in urinary epinephrine excretion and significant depletion of adrenal epinephrine content, both indices of adrenal medullary stimulation. Chronic sc injections of 2-DG in animals with normal or increased food consumption caused simultaneous suppression of cardiac sympathetic nerve activity, as evidenced by diminished cardiac [3H]norepinephrine turnover, and stimulation of adrenal medullary epinephrine release. Parenteral 2-DG administration to adrenalectomized rats also caused suppression of cardiac sympathetic activity. Thus, this response to neuroglycopenia is independent of adrenal medullary catecholamine release. These results indicate that central nervous system glucose metabolism may mediate diet-induced changes in SNS activity.

Rosiglitazone monotherapy is effective in patients with type 2 diabetes.

This study evaluated the efficacy and safety of rosiglitazone monotherapy in patients with type 2 diabetes. After a 4-week placebo run-in period, 493 patients with type 2 diabetes were randomized to receive rosiglitazone [2 or 4 mg twice daily (bd)] or placebo for 26 weeks. The primary end point was change in hemoglobin A(1c); other variables assessed included fasting plasma glucose, fructosamine, endogenous insulin secretion, urinary albumin excretion, serum lipids, and adverse events. Rosiglitazone (2 and 4 mg bd) decreased mean hemoglobin A(1c) relative to placebo by 1.2 and 1.5 percentage points, respectively, and reduced fasting plasma glucose concentrations relative to placebo by 3.22 and 4.22 mmol/L, respectively. Fasting plasma insulin and insulin precursor molecules decreased significantly. Homeostasis model assessment estimates indicate that rosiglitazone (2 and 4 mg bd) reduced insulin resistance by 16.0% and 24.6%, respectively, and improved ss-cell function over baseline by 49.5% and 60.0%, respectively. Urinary albumin excretion decreased significantly in the rosiglitazone (4 mg bd) group. There was no increase in adverse events with rosiglitazone. In the short-term, rosiglitazone is an insulin sensitizer that is effective and safe as monotherapy in patients with type 2 diabetes who are inadequately controlled by lifestyle interventions.

Parallel molecular genetic analysis.

We describe recent progress in parallel molecular genetic analyses using DNA microarrays, gel-based systems, and capillary electrophoresis and utilization of these approaches in a variety of molecular biology assays. These applications include use of polymorphic markers for mapping of genes and disease-associated loci and carrier detection for genetic diseases. Application of these technologies in molecular diagnostics as well as fluorescent technologies in DNA analysis using immobilized oligonucleotide arrays on silicon or glass microchips are discussed. The array-based assays include sequencing by hybridization, cDNA expression profiling, comparative genome hybridization and genetic linkage analysis. Developments in non microarray-based, parallel analyses of mutations and gene expression profiles are reviewed. The promise of and recent progress in capillary array electrophoresis for parallel DNA sequence analysis and genotyping is summarized. Finally, a framework for decision making in selecting available technology options for specific molecular genetic analyses is presented.

Genetic analysis in Italian families with inflammatory bowel disease supports linkage to the IBD1 locus--a GISC study.

Epidemiological studies suggest that inherited factors influence susceptibility to inflammatory bowel disease (IBD), and some candidate loci have been described. In order to verify whether the same loci are responsible for predisposition to IBD in our population, we carried out a linkage study in a series of 58 Italian families with Crohn's disease (CD) and ulcerative colitis (UC). HLA-DQ alleles, motilin gene, and 34 microsatellites flanking the previously described loci on chromosomes 3, 6, 7, 12 and 16 were analysed by non-parametric linkage analysis in 16 and 23 families with CD and UC, respectively, and in 19 families where CD and UC coexisted. Non parametric analysis using GENEHUNTER yielded maximum NPL scores for marker D16S408 in all IBD families combined (2.71, P = 0.003), for marker D16S419 in CD (1.97, P = 0.026) and for marker D16S514 in UC families (2.44, P = 0.007). These markers map in the previously described IBD1 region. No significant linkage was found for markers of chromosomes 3, 6, 7 and 12. The present study performed in a Southern European population provides additional support for the conclusion with the IBD1 locus has a clear role in the genetic susceptibility to IBD.

Iatrogenic Creutzfeldt-Jakob disease.

Over the past 2 years, Creutzfeldt-Jakob disease (CJD) has affected several patients who received cadaver pituitary-derived growth hormone (pit-hGH) and one patient who received a cadaveric dura mater graft. The risk of iatrogenic transmission of CJD has long been recognized, but until recently, the low prevalence of the disorder and minimal use of therapeutic products derived from human tissues may have limited the risk. From 1963 to 1985, approximately 10,000 children received pit-hGH. These patients, exposed to pooled products potentially contaminated with the CJD agent, may have significantly increased the number of individuals whose blood and tissues could transmit CJD. This possibility as well as data on the pathophysiology of CJD and scrapie, a related disease of animals, should guide the development of practices that would limit iatrogenic spread of CJD.