Incorporating Pharmacogenomics into Practice

The goal for this issue of the Journal of Pharmacy Practice is to provide an overview of pharmacogenomics and highlight research done in select therapeutic areas such as oncology, psychiatry, cardiology, and HIV, although pharmacogenomics is taking center stage in other therapeutic areas as well. At the root of all pharmacogenomic investigations is pharmacy, which is why it is so important for pharmacists to gain an understanding of this field and clinical applications of this science, particularly as it relates to their practice and their patients. Pharmacists are experts in pharmacokinetics and pharmacodynamics, and they therefore represent ideal health care professionals for incorporating pharmacogenomics into therapeutic drug monitoring. We are currently in a critical period of time in which pharmacists need to become engaged in the decision-making process regarding how best to implement pharmacogenomics into clinical practice. As part of this chapter, we will outline the role of the Human Genome Project and the Food and Drug Administration, both of which are instrumental to the advancement of pharmacogenomics. Lastly, we will be summarizing some of the barriers we still face regarding clinical applicability of this science and the potential role of genetic counselors in the incorporation of this science into clinical practice.

Pituitary adenoma with paraganglioma/pheochromocytoma (3PAs) and succinate dehydrogenase defects in humans and mice

CONTEXT

Germline mutations in genes coding succinate dehydrogenase (SDH) subunits A, B, C, and D have been identified in familial paragangliomas (PGLs)/pheochromocytomas (PHEOs) and other tumors. We described a GH-secreting pituitary adenoma (PA) caused by SDHD mutation in a patient with familial PGLs. Additional patients with PAs and SDHx defects have since been reported.

DESIGN

We studied 168 patients with unselected sporadic PA and with the association of PAs, PGLs, and/or pheochromocytomas, a condition we named the 3P association (3PAs) for SDHx germline mutations. We also studied the pituitary gland and hormonal profile of Sdhb(+/-) mice and their wild-type littermates at different ages.

RESULTS

No SDHx mutations were detected among sporadic PA, whereas three of four familial cases were positive for a mutation (75%). Most of the SDHx-deficient PAs were either prolactinomas or somatotropinomas. Pituitaries of Sdhb(+/-) mice older than 12 months had an increased number mainly of prolactin-secreting cells and several ultrastructural abnormalities such as intranuclear inclusions, altered chromatin nuclear pattern, and abnormal mitochondria. Igf-1 levels of mutant mice tended to be higher across age groups, whereas Prl and Gh levels varied according to age and sex.

CONCLUSION

The present study confirms the existence of a new association that we termed 3PAs. It is due mostly to germline SDHx defects, although sporadic cases of 3PAs without SDHx defects also exist. Using Sdhb(+/-) mice, we provide evidence that pituitary hyperplasia in SDHx-deficient cells may be the initial abnormality in the cascade of events leading to PA formation.

A time study of cancer genetic counselors using a genetic counselor-only patient care model versus a traditional combined genetic counselor plus medical geneticist care model

Analyses of time-based effort have determined that clinical genetic services are labor-intensive, although these data derive primarily from studying geneticists' efforts in the pediatric model. No studies have investigated the time and patient care activities of cancer genetic counselors (GCs) in traditional clinics with a medical geneticist (GC/MD) compared with genetic counselor-only (GCO) appointments. In this study, 6 GCs prospectively tracked time spent in patient care activities in both clinical settings. The authors found that overall, GCs' time spent per patient was lower for GCO versus GC/MD visits. No differences were seen in time spent on results disclosure, but differences were noted in case preparation, face-to-face, and follow-up times. Furthermore, no differences were seen in number of case preparation activities or topics covered during a session. These data suggest that GCO visits result in better use of GCs' time, without a trade-off in number of patient-related activities.

Prevalence of germline PTEN, BMPR1A, SMAD4, STK11, and ENG mutations in patients with moderate-load colorectal polyps

BACKGROUND & AIMS

Gastrointestinal polyposis is a common clinical problem, yet there is no consensus on how to best manage patients with moderate-load polyposis. Identifying genetic features of this disorder could improve management and especially surveillance of these patients. We sought to determine the prevalence of hamartomatous polyposis-associated mutations in the susceptibility genes PTEN, BMPR1A, SMAD4, ENG, and STK11 in individuals with ≥5 gastrointestinal polyps, including at least 1 hamartomatous or hyperplastic/serrated polyp.

METHODS

We performed a prospective, referral-based study of 603 patients (median age: 51 years; range, 2-89 years) enrolled from June 2006 through January 2012. Genomic DNA was extracted from peripheral lymphocytes and analyzed for specific mutations and large rearrangements in PTEN, BMPR1A, SMAD4, and STK11, as well as mutations in ENG. Recursive partitioning analysis was used to determine cutoffs for continuous variables. The prevalence of mutations was compared using Fisher's exact test. Logistic regression analyses were used to determine univariate and multivariate risk factors.

RESULTS

Of 603 patients, 119 (20%) had a personal history of colorectal cancer and most (n = 461 [76%]) had <30 polyps. Seventy-seven patients (13%) were found to have polyposis-associated mutations, including 11 in ENG (1.8%), 13 in PTEN (2.2%), 13 in STK11 (2.2%), 20 in BMPR1A (3.3%), and 21 in SMAD4 (3.5%). Univariate clinical predictors for risk of having these mutations included age at presentation younger than 40 years (19% vs 10%; P = .008), a polyp burden of ≥30 (19% vs 11%; P = .014), and male sex (16% vs 10%; P = .03). Patients who had ≥1 ganglioneuroma (29% vs 2%; P < .001) or presented with polyps of ≥3 histologic types (20% vs 2%; P = .003) were more likely to have germline mutations in PTEN.

CONCLUSIONS

Age younger than 40 years, male sex, and specific polyp histologies are significantly associated with risk of germline mutations in hamartomatous-polyposis associated genes. These associations could guide clinical decision making and further investigations.

Implementation of universal microsatellite instability and immunohistochemistry screening for diagnosing lynch syndrome in a large academic medical center

PURPOSE

In 2009, the Evaluation of Genomic Applications in Practice and Prevention recommended that all colorectal cancers (CRCs) be screened for Lynch syndrome (LS) through microsatellite instability (MSI) or immunohistochemistry (IHC). No studies report how this process is implemented on a health system-wide basis.

METHODS

Since 2004, Cleveland Clinic has screened CRC specimens with MSI/IHC. Between January 2004 and July 2007, MSI/IHC results went only to the colorectal surgeon (approach 1). Between August 2007 and June 2008, colorectal surgeons and a genetic counselor received the MSI/IHC results, and the counselor e-mailed the colorectal surgeon regarding appropriate patients for genetic counseling (GC) referral (approach 2). After July 2008, the colorectal surgeon and counselor received MSI/IHC results, but the counselor contacted the patient to facilitate referral (approach 3). In approaches 2 and 3, patients were presumed to have sporadic CRC if the tumor lacked MLH1 expression and was also BRAF mutated or if the patient was diagnosed at age greater than 72 years and had no cancer family history.

RESULTS

Abnormal MSI/IHC results occurred in 178 (16%) of 1,108 patients. In approach 1, 21 (55%) of 38 patients with abnormal MSI/IHC were referred for GC, 12 (32%) of 38 underwent GC, and 10 (26%) of 38 underwent genetic testing (GT). In approach 2, nine (82%) of 11 patients were referred for GC, seven (64%) of 11 underwent GC, and five (45%) of 11 underwent GT. In approach 3, 56 (100%) of 56 patients were referred for GC, 40 (71%) of 56 underwent GC, and 37 (66%) of 56 underwent GT. Time from referral to GC was 10-fold quicker in approach 3 than approach 1.

CONCLUSION

Implementation of universal MSI/IHC with GC/GT, along with effective multidisciplinary communication and plans of responsibility for patient contact, resulted in increased identification of patients with LS.

Pharmacogenetics of glutamate system genes and SSRI-associated sexual dysfunction

We examined whether polymorphisms in the GRIK2, GRIA3 and GRIA1 genes were associated with selective serotonin reuptake inhibitor (SSRI)-associated sexual dysfunction in 114 participants treated for depression. One polymorphism in GRIA1 (rs1994862) was associated with arousal dysfunction, providing further evidence for the role of GRIA1 in mechanisms underlying SSRI-associated sexual side effects.

Elevated plasma succinate in PTEN, SDHB, and SDHD mutation-positive individuals

PURPOSE

Cowden syndrome results from germline mutations in the gene for phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and from variants in succinate dehydrogenase B and D subunits. We hypothesized that succinate accumulation may be common among individuals with SDH variants/mutations and those with PTEN mutations.

METHODS

Urine and blood were collected from individuals meeting full or partial Cowden syndrome diagnostic criteria or those with paraganglioma (PGL) or a known susceptibility paraganglioma-associated gene mutation, and succinate was measured. PTEN, SDHB, SDHC, and SDHD genes were sequenced from genomic DNA.

RESULTS

Elevated plasma succinate was observed in 13/21 (62%) individuals with germline PTEN, SDHB, or SDHD mutations as compared with 5/32 (16%) controls (P < 0.001), in 10/15 (67%) individuals with pathogenic PTEN mutations but in <20% of mutation-negative individuals meeting identical criteria, and in individuals with mutations in SDHB (1/1, 100%) and SDHD (2/5, 40%).

CONCLUSION

Our data suggest that mutations in PTEN, SDHB, and SDHD reduce catalytic activity of succinate dehydrogenase, resulting in succinate accumulation, and identify a common biochemical alteration in these two patient populations (PTEN and SDHx mutation positive individuals). Plasma organic acid analysis may provide an effective and inexpensive screening method to determine when more expensive gene sequencing of PTEN and SDH genes is warranted.

Exposure, probable PTSD and lower respiratory illness among World Trade Center rescue, recovery and clean-up workers

BACKGROUND

Thousands of rescue and recovery workers descended on the World Trade Center (WTC) in the wake of the terrorist attack of September 11, 2001 (9/11). Recent studies show that respiratory illness and post-traumatic stress disorder (PTSD) are the hallmark health problems, but relationships between them are poorly understood. The current study examined this link and evaluated contributions of WTC exposures.

METHOD

Participants were 8508 police and 12 333 non-traditional responders examined at the WTC Medical Monitoring and Treatment Program (WTC-MMTP), a clinic network in the New York area established by the National Institute for Occupational Safety and Health (NIOSH). We used structural equation modeling (SEM) to explore patterns of association among exposures, other risk factors, probable WTC-related PTSD [based on the PTSD Checklist (PCL)], physician-assessed respiratory symptoms arising after 9/11 and present at examination, and abnormal pulmonary functioning defined by low forced vital capacity (FVC).

RESULTS

Fewer police than non-traditional responders had probable PTSD (5.9% v. 23.0%) and respiratory symptoms (22.5% v. 28.4%), whereas pulmonary function was similar. PTSD and respiratory symptoms were moderately correlated (r=0.28 for police and 0.27 for non-traditional responders). Exposure was more strongly associated with respiratory symptoms than with PTSD or lung function. The SEM model that best fit the data in both groups suggested that PTSD statistically mediated the association of exposure with respiratory symptoms.

CONCLUSIONS

Although longitudinal data are needed to confirm the mediation hypothesis, the link between PTSD and respiratory symptoms is noteworthy and calls for further investigation. The findings also support the value of integrated medical and psychiatric treatment for disaster responders.

Evil lurks in the heart of man: cardiac paraganglioma presenting as recurrent dyspnoea and chronic cough

A man in his 60s presents with chronic dyspnoea and cough for 3 years. EKG and nuclear stress test were not diagnostic. An echocardiogram revealed moderate pericardial effusion. His symptoms improved with ibuprofen temporarily and a repeat echocardiogram showed resolution of the effusion. However, when his symptoms recurred, re-imaging showed a large intracardiac tumour causing right ventricular outflow obstruction. Subsequent histological examination revealed metastatic paraganglioma. He was found to carry a germline mutation in the SDHB gene which is associated with higher malignant risk. Knowledge of his underlying mutation allowed the patient and his family to receive appropriate gene-specific counselling and surveillance.

Germline SDHx variants modify breast and thyroid cancer risks in Cowden and Cowden-like syndrome via FAD/NAD-dependant destabilization of p53

Cowden syndrome (CS), a Mendelian autosomal-dominant disorder, predisposes to breast, thyroid and other cancers. Germline mutations in phosphatase and tensin homolog (PTEN) have been recently reported in 23% of a large series of classic CS. Here, we validated our small (n = 10) pilot study in a large patient series that germline variations in succinate dehydrogenase genes (SDHx) occur in 8% (49/608) of PTEN mutation-negative CS and CS-like (CSL) individuals (SDH^var+). None of these SDHx variants was found in 700 population controls (P < 0.0001). We then found that SDHx variants also occur in 6% (26/444) of PTEN mutation-positive (PTEN^mut+) CS/CSL individuals (PTEN^mut+/SDH^var+). Of 22 PTEN^mut+/SDH^var+ females, 17 had breast cancers compared with 34/105 PTEN^mut+ (P < 0.001) or 27/47 SDH^var+ patients (P = 0.06). Notably, individuals with SDH^var+ alone had the highest thyroid cancer prevalence (24/47) compared with PTEN^mut+ patients (27/105, P = 0.002) or PTEN^mut+/SDH^var+ carriers (6/22, P = 0.038). Patient-derived SDH^var+ lymphoblastoid cells had elevated cellular reactive oxygen species, highest in PTEN^mut+/SDH^var+ cells, correlating with apoptosis resistance. SDH^var+ cells showed stabilized and hyperactivated hypoxia inducible factor (HIF)1α signaling. Most interestingly, we also observed the loss of steady-state p53 in the majority of SDH^var+ cells. This loss of p53 was regulated by MDM2-independent NADH quinone oxidoreductase 1-mediated protein degradation, likely due to the imbalance of flavin adenine dinucleotide/nicotinamide adenine dinucleotide in SDH^var+ cells. Our data suggest the potential regulation of HIF1α, p53 and PTEN signaling by mitochondrial metabolism in CS/CSL tumorigenesis. Together, our findings suggest the importance of considering SDHx as candidate predisposing and modifier genes for CS/CSL-related malignancy risks, and a mechanism which suggests ways of therapeutic reversal or prevention.

Distinctive phenotype in 9 patients with deletion of chromosome 1q24-q25

Reports of individuals with deletions of 1q24→q25 share common features of prenatal onset growth deficiency, microcephaly, small hands and feet, dysmorphic face and severe cognitive deficits. We report nine individuals with 1q24q25 deletions, who show distinctive features of a clinically recognizable 1q24q25 microdeletion syndrome: prenatal-onset microcephaly and proportionate growth deficiency, severe cognitive disability, small hands and feet with distinctive brachydactyly, single transverse palmar flexion creases, fifth finger clinodactyly and distinctive facial features: upper eyelid fullness, small ears, short nose with bulbous nasal tip, tented upper lip, and micrognathia. Radiographs demonstrate disharmonic osseous maturation with markedly delayed bone age. Occasional features include cleft lip and/or palate, cryptorchidism, brain and spinal cord defects, and seizures. Using oligonucleotide-based array comparative genomic hybridization, we defined the critical deletion region as 1.9 Mb at 1q24.3q25.1 (chr1: 170,135,865-172,099,327, hg18 coordinates), containing 13 genes and including CENPL, which encodes centromeric protein L, a protein essential for proper kinetochore function and mitotic progression. The growth deficiency in this syndrome is similar to what is seen in other types of primordial short stature with microcephaly, such as Majewski osteodysplastic primordial dwarfism, type II (MOPD2) and Seckel syndrome, which result from loss-of-function mutations in genes coding for centrosomal proteins. DNM3 is also in the deleted region and expressed in the brain, where it participates in the Shank-Homer complex and increases synaptic strength. Therefore, DNM3 is a candidate for the cognitive disability, and CENPL is a candidate for growth deficiency in this 1q24q25 microdeletion syndrome.

Variants of the dopamine D2 receptor gene and risperidone-induced hyperprolactinemia in children and adolescents

OBJECTIVE

To investigate the association between hyperprolactinemia and variants of the dopamine D2 receptor (DRD2) gene in children and adolescents in long-term treatment with risperidone.

METHODS

Medically healthy 7 to 17-year-old patients chronically treated with risperidone but receiving no other antipsychotics were recruited in a cross-sectional study. Four DRD2 variants were genotyped and prolactin concentration was measured. Medication history was obtained from the medical records. The effect of the TaqIA variants of the DRD2 on the risk of risperidone-induced hyperprolactinemia was the primary outcome measure.

RESULTS

Hyperprolactinemia was present in 50% of 107 patients (87% males) treated with risperidone for an average of 2.9 years. Age, stage of sexual development, and the dose of risperidone independently predicted a higher prolactin concentration, whereas the dose of psychostimulants was negatively correlated with it. However, these four predictors became nonsignificant when risperidone serum concentration was entered into the model. Adverse events potentially related to hyperprolactinemia were more common in participants with elevated prolactin concentration and in girls (45%) compared with boys (10%). After controlling for risperidone concentration and the dose of psychostimulants, the TaqIA A1 and the A-241G alleles were associated with higher prolactin concentration, whereas the -141C Ins/Del and C957T variants had no significant effect. In addition, adverse events potentially related to hyperprolactinemia were four times more common in TaqIA A1 allele carriers.

CONCLUSION

Prolactin concentration is closely related to central DRD2 blockade, as reflected by risperidone serum concentration. Furthermore, the TaqIA and A-241G variants of the DRD2 gene could be useful in predicting the emergence of hyperprolactinemia and its potential adverse events.

The association of serotonin transporter genotypes and selective serotonin reuptake inhibitor (SSRI)-associated sexual side effects: possible relationship to oral contraceptives

OBJECTIVE

To study the relationship between functional variants in the serotonin transporter gene (SLC6A4) and selective serotonin reuptake inhibitor (SSRI)-associated sexual dysfunction.

METHODS

One hundred fifteen subjects aged 18-40 years and currently being treated with an SSRI for depression were assessed for clinical variables known to affect sexual well-being. SSRI-associated sexual difficulties were assessed with the Changes in Sexual Functioning Questionnaire (CSFQ). Subjects were subsequently genotyped for the SLC6A4 promoter region (5HTTLPR) insertion/deletion variant and a variable number of tandem repeats (VNTR) in the second intron.

RESULTS

The 5HTTLPR insertion/deletion variant was associated with sexual dysfunction in this study sample [odds ratio (OR) = 2.7; 95% confidence interval (CI) 1.2, 6.4; p = 0.02]. The relationship between promoter genotypes and sexual well-being differed in males and females and was related to whether females were taking an oral contraceptive (OC) medication. Females with the ll genotype were nearly eight times more likely to be categorized as having sexual dysfunction if they were taking OCs, while no relationship was observed in those not taking OCs.

CONCLUSIONS

These results suggest that a functional variant in the serotonin transporter gene is associated with sexual difficulties in persons taking an SSRI for depression. This relationship may differ by sex and be dependent on OC status in females.

Leptin and leptin receptor gene polymorphisms and increases in body mass index (BMI) from olanzapine treatment in persons with schizophrenia

OBJECTIVE

The objective of the current investigation was to determine the relationship between polymorphisms of the leptin system (leptin gene and leptin receptor) and olanzapine-induced weight gain in persons with schizophrenia.

DESIGN

Pharmacogenetic association reanalysis of a longitudinal, open label, six week, fixed dose trial of olanzapine response and adverse effects.

SUBJECTS

Thirty-seven males and females with clinically symptomatic schizophrenia (age, 23-52) meeting DSM-IV criteria.

MEASUREMENTS

Baseline and endpoint weight, BMI, olanzapine dose, plasma levels, and psychopathology measures were completed in a prior study. These subjects were subsequently genotyped for the -1548 G/A polymorphism of the leptin gene and the Q223R polymorphism of the leptin receptor. The relationship between alleles at each locus, olanzapine plasma levels, and percent change in body mass index (BMI) from baseline were conducted.

RESULTS

Genotypes and alleles for each locus were not individually associated with olanzapine-induced weight gain in this study population. Changes in BMI from baseline increased significantly in persons with olanzapine plamsa levels >20.6 ng/mL for subjects carrying at least one G allele at both candidate loci compared to those who did not have a G allele at each (P = 0.049).

CONCLUSIONS

This study suggests that genetic variability in the leptin gene and leptin receptor may predispose some individuals to excessive weight gain from increased exposure to olanzapine.

Serotonin 2A -1438 G/A and G-protein Beta3 subunit C825T polymorphisms in patients with depression and SSRI-associated sexual side-effects

The occurrence of sexual side-effects from antidepressants is thought to be mediated through serotonin 2A (5HT2A) receptors. It is currently unknown if functional polymorphisms in the 5HT2A receptor or its G-protein second messenger complex are related to sexual dysfunction in patients taking an selective serotonin reuptake inhibitor (SSRI) for depression. The purpose of this study was to determine the relationship of the 5HT2A -1438 G/A and GNB3 C825T single nucleotide polymorphisms with overall sexual well-being and individual components of sexual health as measured by the Changes in Sexual Functioning Questionnaire (CSFQ). We evaluated 89 outpatients (18-40 years of age) at low risk for other causes of sexual dysfunction who were being treated for depression with an SSRI and did not have sexual difficulties before taking the antidepressant. Outcome measures were stratified by 5HT2A and GNB3 genotypes. After controlling for age, gender, anxiety scale scores, and depression scale scores, persons with a GG genotype of the 5HT2A -1438 single nucleotide polymorphisms (SNP) were significantly more likely to be categorized as having sexual dysfunction than persons with a GA or AA genotype (OR=3.6; 95% CI 1.03, 12.6; p=0.046). Furthermore, the 5HT2A -1438 GG genotype was a significant predictor of lower arousal scores (p=0.022) after accounting for other measures. There was no significant relationship between any outcome measure and GNB3 genotype.

Pilot study of the G-protein beta3 subunit gene (C825T) polymorphism and clinical response to olanzapine or olanzapine-related weight gain in persons with schizophrenia

BACKGROUND

Despite advances in schizophrenia treatment, nearly 30% of patients do not respond to atypical antipsychotic agents, such as olanzapine. Furthermore, 30-60% of patients will gain significant weight during the course of olanzapine therapy. Little research has been done to investigate the relationship between antipsychotic treatment outcomes and genetic variability in second messengers coupled to serotonin (5HT) receptors. The purpose of this investigation was examine associations between the second messenger G-Protein Beta3 Subunit Gene (GNB3) C825T polymorphism and olanzapine response and weight gain treatment.

MATERIAL/METHODS

We conducted a pharmacogenetic association study to examine GNB3 genotypes in relation to olanzapine clinical response (as measured by the Brief Psychiatric Rating Scale or Scale for the Assessment of Negative Symptoms) or weight gain. Subjects included forty-two individuals meeting DSM-IV criteria for schizophrenia that started olanzapine, were titrated to a fixed dose for 6 weeks, and subsequently genotyped for this investigation.

RESULTS

No statistically significant associations existed between our outcome variables and GNB3 genotypes. However we did observe trends suggesting a potential relationship between the TT genotype, response, and weight gain that warrant further investigation.

CONCLUSIONS

Preliminary results showed no statistical relationship between the C825T polymorphism and olanzapine response or weight gain. Numerical differences in outcome measures between the TT vs. CT/CC genotype groups indicate that G-protein second messenger systems variability coupled to primary targets of atypical antipsychotics may relate to clinical outcomes in persons with schizophrenia and that future research in this area is warranted.

Divergent histories of rDNA group I introns in the lichen family Physciaceae

The wide but sporadic distribution of group I introns in protists, plants, and fungi, as well as in eubacteria, likely resulted from extensive lateral transfer followed by differential loss. The extent of horizontal transfer of group I introns can potentially be determined by examining closely related species or genera. We used a phylogenetic approach with a large data set (including 62 novel large subunit [LSU] rRNA group I introns) to study intron movement within the monophyletic lichen family Physciaceae. Our results show five cases of horizontal transfer into homologous sites between species but do not support transposition into ectopic sites. This is in contrast to previous work with Physciaceae small subunit (SSU) rDNA group I introns where strong support was found for multiple ectopic transpositions. This difference in the apparent number of ectopic intron movements between SSU and LSU rDNA genes may in part be explained by a larger number of positions in the SSU rRNA, which can support the insertion and/or retention of group I introns. In contrast, we suggest that the LSU rRNA may have fewer acceptable positions and therefore intron spread is limited in this gene.

Association between the polymorphic GRM3 gene and negative symptom improvement during olanzapine treatment

PURPOSE

The excitatory neurotransmitter glutamate has become an important area of focus for schizophrenia researchers. Polymorphisms in the type-three metabotropic glutamate receptor gene (GRM3) have been associated with the pathogenesis of schizophrenia. The purpose of this study was to determine whether a pharmacogenetic relationship exists between six polymorphisms of GRM3 and clinical improvement during olanzapine treatment in persons with schizophrenia.

METHOD

Forty-two subjects meeting DSM-IV criteria for schizophrenia started olanzapine and were titrated to a fixed dose of 7.5-20 mg/day for 6 weeks. The Brief Psychiatric Rating Scale (BPRS) total score and the Scale for Assessment of Negative Symptoms (SANS) were completed at baseline and then weekly to assess psychopathology.

RESULTS

The principle finding of this study is that GRM3 polymorphisms were collectively significant predictors of negative symptom improvement in persons with schizophrenia treated with the atypical antipsychotic olanzapine. After controlling for baseline SANS scores, the genotypes as a whole were significant predictors of negative symptom improvement, accounting for approximately 28% of the variance in scores (F = 16.30, df = 29, p < 0.001). The single nucleotide polymorphism SNP1 (rs274622), located in a potential promoter region, had the most significant influence on SANS scores, but the effects of this locus could not be fully separated from the other polymorphisms. The mean decrease in SANS scores was 21% vs. 51% for SNP1 T/T + T/C and SNP1C/C subjects, respectively.

CONCLUSION

These data suggest that polymorphisms in the GRM3 gene may be useful as predictors of negative symptom improvement in persons with schizophrenia treated with olanzapine.

Breast-feeding and serum p,p'DDT levels among Mexican women of childbearing age: a pilot study

For almost 50 years, millions of Mexicans have been directly and/or indirectly exposed to (1,1,1-trichloro-2,2-bis[p-chlorophenyl]ethane) (p,p'DDT). The potential related health outcomes of this exposure are of international concern. The objective of the study was to determine the effect of breast-feeding on serum levels of 1,1-dichloro-2; 2'-bis(p-chlorophenyl)ethylene (p,p'DDE) and p,p'DDT in women of childbearing age who were residents of the state of Morelos, Mexico. In March 1999, we examined a sample of 24 women, ages 21 to 36 years, who came with their children to the outpatient facility of a county Health Center in the state of Morelos. The geometric mean for p,p'DDE was 21.8 ng/ml+/-2.58 (GSD) and 2.9 ng/ml+/-2.84 for p,p'DDT. For each month of breast-feeding we observed similar significant decreases for both p,p'DDE (beta=-0.0403 per log concentration unit, P=0.001) and p,p'DDT (beta=-0.0309, P=0.03) serum levels, adjusted by mothers' age and number of children. The adjusted half-life estimate for p,p'DDE serum levels was 17 months. It was concluded that breast-feeding leads to rapid removal of p,p'DDT from the body (<2 year half-life) compared to nonlactational elimination rates (<5 year half-life). In this population, serum p,p'DDE levels were similar to those found 20 years ago in the United States.

Lactation and lead body burden turnover: a pilot study in Mexico

A pilot study was conducted in Morelos, Mexico in March 1999 to assess the body burden of lead in 24 Mexican women of childbearing age. Lead levels were measured in whole blood and at three bone sites: two primarily trabecular (calcaneus and patella) and one primarily cortical (tibia). Demographic and reproductive characteristics of the women and potential sources of lead exposure were gathered by a direct interview. An inverse relationship was noted between months of lactation and age-adjusted calcaneus lead level (P = 0.001). No association was observed between age-adjusted patella or tibia lead level and months of lactation (P = 0.15). Blood lead levels were positively associated with the use of lead-glazed ceramics (P = 0.01). Bone and blood lead levels were observed to be 77% higher in these rural Mexican women than in urban New York City women. This pilot study provides further limited evidence for the hypothesis that lead mobilization occurs during lactation.

Dietary flavonoids and hypertension: is there a link?

High blood pressure, defined as systolic blood pressure of greater than 140 mmHg or diastolic blood pressure of greater than 90 mmHg affects millions of people throughout the world. A number of studies have shown that consumption of fruit, vegetables, wine and tea may protect against stroke, for which hypertension is the major risk factor. Flavonoid compounds, including flavonols, flavones and isoflavones, represent an important source of antioxidants in the diet. Flavonoid intake has been inversely associated with mortality from coronary heart disease and stroke. We hypothesize that individuals with hypertension have lower circulating flavonoid levels. Increased consumption of flavonoid-rich foods may decrease rates of hypertension. Lowering blood pressure through increased dietary consumption of dietary antioxidants may decrease the rate of end-organ damage that is secondary to hypertension.

A cluster of pediatric metallic mercury exposure cases treated with meso-2,3-dimercaptosuccinic acid (DMSA)

Nine children and their mother were exposed to vapors of metallic mercury. The source of the exposure appears to have been a 6-oz vial of mercury taken from a neighbor's home. The neighbor reportedly operated a business preparing mercury-filled amulets for practitioners of the Afro-Caribbean religion Santeria. At diagnosis, urinary mercury levels in the children ranged from 61 to 1,213 microg/g creatinine, with a geometric mean of 214.3 microg/m creatinine. All of the children were asymptomatic. To prevent development of neurotoxicity, we treated the children with oral meso-2,3-dimercaptosuccinic acid (DMSA). During chelation, the geometric mean urine level rose initially by 268% to 573.2 microg mercury/g creatinine (p<0.0005). At the 6-week follow-up examination after treatment, the geometric mean urine mercury level had fallen to 102.1 microg/g creatinine, which was 17.8% of the geometric mean level observed during treatment (p<0.0005) and 47.6% of the original baseline level (p<0.001). Thus, oral chelation with DMSA produced a significant mercury diuresis in these children. We observed no adverse side effects of treatment. DMSA appears to be an effective and safe chelating agent for treatment of pediatric overexposure to metallic mercury.

Women, work, and health

The U.S. Bureau of National Affairs has conducted several surveys asking women to rate the seriousness of 11 hazards thought to affect female workers. In 1995 the women respondents ranked them in the following order: 1) stress, 2) repetitive motions, 3) AIDS, 4) violence, 5) VDTs, 6) indoor air pollution, 7) hepatitis, 8) injury on the job, 9) reproductive hazards, 10) tuberculosis, and 11) other infectious diseases. A parallel list of 11 hazards thought to affect male workers would look very different. The purpose of this paper is to explore why this is so and what it implies for the occupational health research agenda.

Risks of developing noise-induced hearing loss in employees of urban music clubs

Noise-induced hearing loss has previously been reported among rock musicians. This study sought to determine whether a hazard of noise-induced hearing loss exists for music club employees other than musicians themselves. Sound levels at eight live-music clubs were measured and symptoms of noise exposure in 31 music club employees were assessed by questionnaire. The average sound level at the various clubs during performances ranged from 94.9 to 106.7 dBA. The overall sound level average, including both performance and ambient levels, ranged from 91.9 to 99.8 dBA. Symptoms of noise exposure, such as tinnitus and subjective hearing loss, correlated with sound intensity. Only 16% reported regular use of hearing protection. We conclude that employees of music clubs are at substantial risk of developing Noise-Induced Hearing Loss, due to chronic noise exposure which consistently exceeded safe levels. Hearing protection is used much too infrequently. The development of hearing conservation programs for this large group of workers is essential.

Virtual reality for health care: a survey

This report surveys the state of the art in applications of virtual environments and related technologies for health care. Applications of these technologies are being developed for health care in the following areas: surgical procedures (remote surgery or telepresence, augmented or enhanced surgery, and planning and simulation of procedures before surgery); medical therapy; preventive medicine and patient education; medical education and training; visualization of massive medical databases; skill enhancement and rehabilitation; and architectural design for health-care facilities. To date, such applications have improved the quality of health care, and in the future they will result in substantial cost savings. Tools that respond to the needs of present virtual environment systems are being refined or developed. However, additional large-scale research is necessary in the following areas: user studies, use of robots for telepresence procedures, enhanced system reality, and improved system functionality.

Lung cancer mortality in a French cohort of hard-metal workers

A cohort mortality study was carried out among workers of a plant producing hard metals using cobalt as a binder. This study was aimed at assessing possible lung cancer risks in relation with cobalt exposure. Seven hundred nine male workers with at least 1 year of employment were included in the cohort and followed for mortality from 1956 to 1989. Job histories were provided by the administration of the plant, whereas smoking habits were collected from medical records and by interview. The causes of deaths were ascertained from hospital and general practitioner records. The observed numbers of deaths (obs) were compared with the expected based on national rates with adjustment for age, sex, and calendar time (standardized mortality ratio; SMR). The overall mortality did not differ from that expected (obs = 75, SMR = 1.05), whereas mortality due to lung cancer was in significant excess (obs = 10, SMR = 2.13). This excess was higher among workers employed in the areas with the highest exposure (obs = 6, SMR = 5.03). No trend was observed, however, with duration of employment or time since first employment. Smoking data were available for 81% of the workers and 69% of the deceased and showed that smoking alone does not account for these lung cancer excesses, yet, because of the small numbers involved, no firm conclusion should be drawn from this study.

[Measurement of peak expiratory flow and altitude]

Readings of peak-expiratory flow rate (PEFR) in twelve healthy alpinists at sea level (Lima) and at 3800 m (Yanganugo) show a significant slight fall with altitude (p less than 0.05). This study corroborates previous reports (Singh et al., 1969; Stockley et al., 1979). However, Forster (1983) taking in account the effect of air density on the functioning of peak-flow meter suggested that actual PEFR increases slightly with altitude. In the present study, corrected data show an increase of PEFR by about 3% at 3800 m, similar to Forster's results (at 4200 m). Air density must be considered in future studies in altitude and in estimation of clinical improvement of asthmatic people living in mountain health resort.

[Angiectasis of the colon (Moore's type I angiodysplasia). One case (author's transl)]

A 60-year-old man had severe, recurrent rectal haemorrhages. Arteriography showed lesions suggestive of angiodysplasia located in the initial part of the ascending colon. Right-sided hemicolectomy was performed. Angiectasis of the colon is acquired and degenerative. It affects elderly people and is due to dilatation of the veins in the mucosa of the ascending colon. The lesions are usually too small to be detected by barium enema or colonoscopy, but arteriography of the superior mesenteric artery shows pathognomonic images. The only treatment is right-sided hemicolectomy.

The radiospirometric flow-volume diagram recording technique and comparative study with conventional spirometry

The spirometric flow-volume diagram recorded for a forced expiration gives information which is used in assessing obstructive or restrictive pulmonary diseases. Regional data of the same kind can be achieved using a simple radiospirometric technique and scintillation camera. A series of images during inspiration and expiration are defined and a time-activity curve with an integration time constant of about 100-200 ms is obtained from the images during the forced expiration phase. The equivalent of the flow-volume diagram, i.e., the time derivative of the activity vs. activity is computed. There were 21 subjects studied in this series. Normal subjects or patients with various diseases underwent classical spirometry, so that the global radioactive diagram could then be compared to the spirometric flow-volume diagram and its parameters expressed in terms of volumes and flow: vital capacity, peak flow, mean flow, flow at mean volume. The correlation with classical spirometry is highly significant. Similarly regional data are consistent with the pulmonary results.

[Radio-electrogastro-enterographic correlations (author's transl)]

Recording of the electro-gastro-enterogram (E.G.E.G.) and the simultaneous taking of a 70 mm ampliphotography series shows the high degree of correlation between E.G.E.G. and peristaltis, with characteristic waves for each part of the digestive tract, both in the normal condition as well as in certain pathological states. The future and role of the E.G.E.G. appear very promising, on the one hand by virtue of its simplicity and secondly because of the information it is capable of providing from a functional viewpoint. In no case, however, can it replace the precise nature of radiological images.

[Electrogastroenterographic study of the digestive motor effects of prolonged psychotropic treatment]

Functional digestive complaints are frequent in psychiatri patients: simple constipation, which cannot be explained solely by the loss of the sensation of rectal fullness; occlusions, occasionally hemorragies; the late complication of dolichomegacolon (Bourgeois, 1973). In 160 subjects, an attempt to understand the physio-pathology were made by recording diurnal digestive motor activity using skin electrodes placed on the abdomen and extremities (electrogastroenterography or E.G.E.G.). A hypoactive E.G.E.G. was observed in 2/3 of 18 psychotic depressive patients, in 3/4 of 36 schizophrenies. The nocive effect of giving sedative phenothiazine and antiparkinsonian drugs (trihexyphenidyl or ethybenzatropine) during long periods is clear. Whereas non sedative phenothiazine and clotiapine gicen in small doses, do not have an undesirable effect. Sulpiride has been used in gastroduodenal dyskinesia. The dyskinesia noted by the E.G.E.G., sometimes found in the large intestin, were found in 55% of 30 patients with caracter disorders; they coincide with the high frequency of electro-encephalogram dysrythmies. Finally, in hysterical patients, one usually observes normal E.G.E.G., tracings which confirms the clinical observation that hysterical and psychosomatic symptoms, may succeed each other, but do not appear at the same time. In the same categories of patients, no longer treated in a classical psychiatric environment but in a group with institutional objectives, the same clinic results were obtained with fewer digestive disturbances. This tends to show the inutility and nocivity of excessive doses of psychotropic drugs given alone or in complexe association.

[Diffuse interstitial pulmonary fibrosis. Responsibility of hard metals]

In a factory processing Tungsten carbide and hard metals, of a hundred exposed workers, 15 showed signs of "irritation" which progressed in 5 to clinical, radiological and functional pulmonary fibrosis with altered CO transport. In one patient histological sections were studied and typical findings of dust inclusion seen. Diffuse interstitial fibrosis related to heavy metals is still not yet recognised as an industrial disease in France.