The Role of Lymphoscintigraphy in the Management of the Patient With Breast Cancer

INTRODUCTION

Regional nodal status is the most powerful predictor of recurrence and survival in women with breast cancer. Lymphatic mapping and sentinel lymph node (SLN) biopsy have been found to accurately predict the regional nodal status. Preoperative lymphoscintigraphy has been used in melanoma patients to identify the basins at risk for metastases when primary sites are located in watershed areas of the body. This study was performed to define the role of lymphoscintigraphy for axillary nodal staging in women with breast cancer. Specifically, can preoperative lymphoscintigraphy define a population of women with breast cancer who have multidirectional drainage or who do not drain to the axilla and need no axillary dissection?

METHODS

516 patients with invasive breast cancer were accrued in a national breast lymphatic mapping trial sponsored by the U.S. Department of Defense. Preoperative lymphoscintigraphy images were produced using filtered technetium-99 sulfur colloid. Lymphatic drainage to axillary and internal mammary sites was noted.

RESULTS

Drainage to an axillary SLN was found in 335 (65%) patients, and internal mammary or extra-axillary drainage was noted in 52 (10%) patients. By using sensitive hand-held probes and vital blue dye intraoperatively, the overall success rate of finding an axillary SLN was 85%. Of the 335 patients who had an axillary SLN identified with imaging, all had successful SLN biopsy procedures. Although no SLNs could be imaged in 181 patients, 153 (85%) of these patients had an axillary SLN identified with intraoperative mapping. For 28 patients in which lymphoscintigraphy was negative and intraoperative mapping was unsuccessful, complete axillary node dissection was performed, and 13 (46%) of these patients were found to have metastatic disease in the basin.

CONCLUSIONS

Preoperative lymphoscintigraphy can identify those women with primary breast cancers who have extra-axillary regional basin drainage such as internal mammary. The ability to image an axillary SLN was associated with a high success rate of being able to find the node intraoperatively with a combination mapping technique. In a high percentage of patients with negative lymphoscintigraphy, the SLN was identified with more sensitive hand-held probes. Therefore, patients who have a negative preoperative lymphoscintigraphy and intraoperatively are found to have no "hot" spot in the axilla with the hand-held probe still need an axillary node dissection, because 46% of these patients contain metastatic disease in the axilla.

Learning curves and breast cancer lymphatic mapping: institutional volume index

INTRODUCTION

To date, studies of breast cancer lymphatic mapping (LM) have analyzed success with respect to individual surgeons. However, LM and sentinel lymph node biopsy (SLNBx) are procedures that require institutional multidisciplinary cooperation between the departments of radiology, pathology, and surgery. Thus, it is important to evaluate these procedures with respect to the institution. This study examines 30 institutions to clarify the value of the institutional volume index (IVI) (cases/month) to the outcome of LM and SLNBx in breast cancer.

METHODS

From July 1997 to July 1999, 30 institutions participated in the Department of Defense national breast LM trial. All participants underwent a 2-day training course for surgeons, nuclear medicine physicians, and pathologists. The records for each institution were prospectively accrued and submitted to a database. The false negatives, failure rates, and IVI were calculated for each institution. A logistic regression model plots the relationship between IVI and institutional failure rate. Using a multivariate analysis, mapping failure was analyzed as a function of case number with respect to the individual surgeon and the institution as a whole.

RESULTS

False negative results were demonstrated in only 5 (4%) cases among all institutions and were excluded from further analysis due to small numbers. Mapping failures were found in all but 7 of the 30 institutions whose data were complete. There were 71 mapping failures among 74 surgeons over 555 cases, which yielded an overall failure rate of 12.79% (71 555). The logistic regression model revealed an inverse relationship between IVI and institutional failure rate. However, the multivariate analysis revealed that the individual surgeon performance was the most significant factor in determining institutional mapping success.

CONCLUSION

Failure to map can be a function of multiple factors including surgical skill, surgical volume index, and injection method of the SLN patient, all under the quality control of an institution. The surgical failure rate on the other hand is a function of surgical skill, surgical volume, and injection methods. While differences in mapping success exist across institutions, this disparity is not due to factors associated with the institution as a whole, but lie with the individual surgeon.

Placebo-controlled study of divalproex sodium for agitation in dementia

The authors assessed the efficacy, tolerability, and safety of divalproex sodium for the treatment of agitation associated with dementia in a 6-week, randomized study of 56 nursing home patients with agitation and dementia treated with either placebo or individualized doses of divalproex sodium. Participants were blinded to treatment except for a physician-monitor and a pharmacist. When several covariates were taken into account, the drug/placebo difference in Brief Psychiatric Rating Scale Agitation scores became statistically significant (P=0.05). Sixty-eight percent of patients on divalproex were rated as showing reduced agitation on the Clinical Global Impression scale, vs. 52% on placebo (P=0.06 in the adjusted analysis). Side effects occurred in 68% of the divalproex group vs. 33% of the placebo group (P=0.03) and were generally rated as mild. This placebo-controlled study, despite some limitations, suggests possible short-term efficacy, tolerability, and safety of divalproex for agitation in dementia and supports further placebo-controlled studies.

The Role of Copper Suppression as an Antiangiogenic Strategy in Head and Neck Squamous Cell Carcinoma

OBJECTIVE

To determine whether tetrathiomolybdate (TM), a powerful chelator of copper, is capable of lowering the body stores of copper and suppressing the growth of head and neck squamous cell carcinoma in an orthotopic murine model.

STUDY DESIGN

In vivo, murine model.

METHODS

Twelve 8-week-old male C3H/HeJ mice were assigned to either a TM treatment group (n = 7) or a control group (n = 5). Serum samples were obtained from a single mouse in each group to measure the level of ceruloplasmin as a surrogate marker of total body copper on days 0, 4, and 7. Mice in both groups received a floor-of-mouth injection of 1.5 x 105 SCC VII/SF cells. After 7 to 10 days of tumor growth the treatment group received fresh water daily, to which TM was added to achieve an oral intake of 50 mg per mouse. The control group received only fresh drinking water daily. Tumor volume measurements were obtained every other day. Microvessel density counts were assessed in the tumors by Factor VIII analysis.

RESULTS

Measurable tumor growth was achieved in 100% of the mice by the tenth day. Total body copper was reduced by 28% from baseline levels in mice in the treatment group. The difference in mean tumor volume in the control group was 4.7 times greater than the TM-treated group at the completion of treatment (3004 mm3 and 633mm3, respectively). This accounted for an overall suppression rate of 79% (P =.008; two-tailed Student t test). In addition, microvessel density was reduced by 50% in the TM-treated group.

CONCLUSION

In this initial study, the first of its kind in head and neck squamous cell carcinoma, we have demonstrated the ability of TM to significantly suppress both the growth of squamous cell carcinoma and tumor vascularity in this orthotopic murine model, suggesting its potential for efficacy in the treatment of this disease in humans.

The Caregiver Quality of Life Index-Cancer (CQOLC) scale: development and validation of an instrument to measure quality of life of the family caregiver of patients with cancer

Family caregivers have become increasingly responsible for providing home care for cancer patients. Research has documented the distress of family caregivers; however, little has been done to evaluate the broader impact of caregiving on quality of life (QoL). The objectives of this study were to evaluate the reliability and validity of the Caregiver Quality of Life Index-Cancer (CQOLC), a new self-report instrument. Two hundred and sixty-three family caregivers of patients with lung, breast or prostate neoplasms participated. Test-retest reliability was 0.95 and internal consistency was 0.91. As expected, there were moderate correlations with overall mental health (r = 0.64), emotional distress (r = -0.50 to -0.52), burden (r = -0.65) and patient's performance status (r = -0.47) and low correlations with overall physical health (r = 0.13), social support (r = 0.22) and social desirability (r = 0.08). These results show that increased overall mental health is associated with better QoL, while more emotional distress and worsening patient performance status are associated with poorer QoL. Thus, the CQOLC appears to possess adequate validity, test-retest reliability and internal consistency. Future directions include further evaluation of sensitivity to change and factor analysis to determine the principal health-related QoL domains evaluated by the CQOLC.

Anxiety and functional status in older primary care patients

OBJECTIVE

The aim of this study was to test the hypothesis that anxiety in older primary care patients is associated with functional impairment after controlling for depression and medical comorbidity.

METHOD

Primary care patients (n = 303), aged sixty or older were interviewed with a series of instruments designed to measure psychiatric symptoms including anxiety, depression, medical illness burden, and both examiner-rated and self-reported functional status. Anxiety was measured by the anxiety item of the Hamilton Rating Scale for Depression and the anxiety items of the Medical Outcomes Study Short Form SF-36. Multiple regression techniques were used to examine the association of anxiety with functional status after controlling for age, gender, education, medical burden, and depression.

RESULTS

When controlled for depression and medical morbidity, increased anxiety predicted poorer social function. Anxiety was not independently associated with more basic activities of daily living.

CONCLUSIONS

Further studies with more comprehensive measures of anxiety are warranted to clarify the relationships between anxiety and functional status.

Management of obstetric emergencies and trauma (MOET): regional questionnaire survey of obstetric practice among career obstetricians in the United Kingdom

Across specialties in the UK concern exists that the shortened training time, combined with the restriction on hours of work, will result in trainees being short of the necessary depth and breadth of experience for independent practice at the end of their defined training period. In terms of risk management, it is recognised that high reliability organisations anticipate the worst and equip themselves to deal with it at all levels in the organisation. Alternative methods of assessment and training need to be utilised, including models and scenario teaching. While it is important for clinicians to learn common skills well before practising on the labour ward, it is correspondingly more important that rare complications be rehearsed with models. In the UK, the MOET (Managing Obstetric Emergencies and Trauma) course has been developed to allow specialist obstetricians to learn, or revise, how to undertake procedures on models, and then to have their skills tested in scenarios. This survey aimed to ascertain the views of career obstetricians in terms of their ability to respond to some of the course scenarios and how frequently the rarest procedures have been undertaken. A one-page questionnaire with 15 questions, based on clinical scenarios taught on the MOET (Managing Obstetric Emergencies and Trauma), course was sent to all career obstetricians in the West Midlands region. Participants were asked to indicate whether they thought a particular management was 'good practice', 'bad practice' or 'good practice but would prefer a caesarean section' and to indicate the number of such procedures they had undertaken in their obstetric career. The response rate was 40% (97/243). There was a broad spectrum in obstetric views about 'good' and 'bad' practice. Overall the respondents agreed with the literature in terms of practices that are regarded as 'good' and 'bad'. A large proportion of respondents, however, would rather undertake a caesarean section than carry out a 'good' practice. Twenty-six obstetricians had experience in the rare obstetric procedures. Of these, 16 (66%) had worked outside the UK, either in the Middle East, South East Asia, Africa or the Caribbean. This survey highlights the need for training courses to teach and revise operative procedures.

Comparative sensitivity of human fetal and adult erythrocytes to hemolysis by pulsed 1 MHz ultrasound

Human fetal and adult erythrocytes differ significantly in mean corpuscular volume (MCV), the fetal cells being larger than adult cells and diminishing in MCV as gestational age (GA) increases. Previous studies have shown that the sensitivity of erythrocytes from different species to lysis by mechanically applied shear stress increases as MCV increases. The tested hypotheses in the present project were: 1. fetal erythrocytes would be more sensitive to sonolysis than adult erythrocytes because of the former's larger size, and 2. erythrocyte sonolytic sensitivity would scale with MCV. Fetal and adult erythrocytes were resuspended to 40% hematocrit in oxygenated isotonic saline solution and 500 microL aliquots were exposed for 60 s to 200 micros bursts of 1-MHz ultrasound (US) (peak pressures: approximately 4.8 MPa positive, approximately 2.7 MPa negative; duty factor = 0.01), either with or without 3.6 volume % Albunex (ALX) present. Background-corrected hemolysis was indistinguishable from zero in sham-exposed fetal or adult erythrocyte suspensions. Without ALX, mean background-corrected US-induced hemolysis was significantly greater than zero for fetal and adult cells (0.42 +/- 0.15% vs. 0.62 +/- 0.15), but fetal cell lysis was not significantly greater than adult cell lysis. With ALX, US-induced hemolytic yields increased approximately 80-fold (fetal: 50.53 +/- 2.14; adult: 46.40 +/- 1.85%), and were significantly higher for fetal than for adult cells. There was also a statistically significant correlation between MCV and US-induced background-corrected hemolysis. Thus, the two hypotheses were supported.

Depression and self-reported functional status in older primary care patients

OBJECTIVE

The authors' goal was to examine whether depression is associated with overreporting of functional disability.

METHOD

The subjects were 304 patients 60 years old or older who were recruited from primary care settings. Measures included examiner ratings of depression diagnosis and medical burden and self-reported and examiner-rated functional assessments. Multiple regression techniques were used to determine the independent association of depression with self-reported function after examiner-rated function was added to the analysis as a covariate.

RESULTS

Depression diagnosis was associated with poorer self-reported role functioning, whether the patient attributed the disability to physical or emotional causes. Depression was not independently associated with poorer self-reported physical functioning.

CONCLUSIONS

Clinicians and researchers should recognize that depression can confound the self-reporting and attribution of functional disability.

A randomized, controlled trial of remacemide for motor fluctuations in Parkinson's disease

BACKGROUND

Preclinical studies suggest that glutamate antagonists help ameliorate motor fluctuations in patients with PD treated with levodopa.

METHODS

In a multicenter, randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study, the authors assessed the safety, tolerability, and efficacy of the glutamate receptor blocker remacemide hydrochloride in 279 patients with motor fluctuations treated with levodopa. The primary objective was to assess the short-term tolerability and safety of four dosage levels of remacemide during 7 weeks of treatment. Patients were also monitored with home diaries and the Unified PD Rating Scale (UPDRS) to collect preliminary data on treatment efficacy.

RESULTS

Remacemide was well tolerated up to a dosage of 300 mg/d on a twice daily schedule and 600 mg/d on a four times daily schedule. The most common dosage-related adverse events were dizziness and nausea, as observed in previous studies of remacemide. The percent "on" time and motor UPDRS scores showed trends toward improvement in the patients treated with 150 and 300 mg/d remacemide compared with placebo-treated patients, although these improvements were not significant.

CONCLUSION

Remacemide is a safe and tolerable adjunct to dopaminergic therapy for patients with PD and motor fluctuations. Although this study had limited power to detect therapeutic effects, the observed improvement is consistent with studies of non-human primates with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinsonian signs and symptoms. Additional studies are warranted to confirm these results over an extended period of observation, and to explore the potential neuroprotective effects of remacemide in slowing the progression of PD.

Encephalopathy associated with respiratory syncytial virus bronchiolitis

Respiratory syncytial virus is an extremely common cause of childhood respiratory infections resulting in significant morbidity and mortality. Although apnea is a well-known complication in young infants with respiratory syncytial virus bronchiolitis, the encephalopathy associated with this infection is not well recognized. Our study reveals an incidence of encephalopathy of 1.8% in a total of 487 patients with respiratory syncytial virus bronchiolitis studied over a period of almost 4 years. Seizures were the presenting complication. Based on our study of a cohort of children with respiratory syncytial virus bronchiolitis, we believe that neurologic complications, although relatively uncommon, represent a significant component of this common childhood illness. Furthermore, respiratory syncytial virus has been shown to release several mediators that could directly or indirectly be neurotoxic and induce an encephalopathy associated with the respiratory illness.

Improving adolescent preventive care in community health centers

OBJECTIVE

To evaluate implementation of the Guidelines for Adolescent Preventive Services (GAPS) in Community and Migrant Health Centers (CMHCs).

DESIGN

Before and after comparison of health center policy, clinician and adolescent self-report, and chart reviews in 5 CMHCs.

PARTICIPANTS

Eighty-one preintervention and 80 one-year postintervention providers and 318 preintervention and 331 postintervention 14- to 19- year-old adolescent patients being seen for well visits at 5 CMHCs.

INTERVENTION

Health center staff were trained to implement GAPS and were provided resource materials, patient questionnaires, and clinician manuals.

MAIN OUTCOME MEASURES

Delivery of and receipt of preventive services and perceived access to care.

RESULTS

CMHC systems changes were related to stronger leadership commitment to adolescent care. Providers reported high levels of preventive services delivery before and after guideline implementation. After guideline implementation, adolescents reported increases in having discussed prevention content with providers in 19 of 31 content areas, including increased discussion of physical or sexual abuse (10% before to 22% after), sexual orientation (13% to 27%), fighting (6% to 21%), peer relations (37% to 52%), suicide (7% to 22%), eating disorders (11% to 28%), weapons (5% to 22%), depression (16% to 34%), smokeless tobacco (10% to 29%), and immunizations (19% to 48%). Adolescents were also more likely to report knowing where to get reproductive or mental health services and were more likely to have received health education materials. Implementation also increased documentation of recommended screening and counseling in 51 of 79 specific content areas assessed in chart reviews.

CONCLUSION

Implementing GAPS increased the receipt of preventive services at these health centers. Adolescents received more comprehensive screening and counseling, more health education materials, and had greater access to care after implementation. GAPS implementation may help improve the quality of care for adolescents.

Suicide and Alzheimer's pathology in the elderly: a case-control study

BACKGROUND

The single most important risk factor for Alzheimer's pathology is age. Elderly individuals are also at increased risk for suicide, but comprehensive studies of the association between Alzheimer's pathology and suicide are lacking. We designed the current study to determine if Alzheimer's disease changes are overrepresented in elderly people committing suicide.

METHODS

The design is a case-control study. Cases (n = 28) were subjects older than 60 years of age who completed suicide. For each case, two age- and gender-matched individuals who died naturally were selected as control subjects (n = 56). Neuropathologic examination of hippocampal sections was performed blindly and included a modified Braak scoring system and semiquantitative assessment of neurofibrillary tangles, amyloid deposition, Lewy bodies, and Lewy-associated neurites. Data were analyzed by conditional logistic regression.

RESULTS

The brains of individuals who committed suicide had higher modified Braak scores than those of matching control subjects (p =.0028). The number of neurofibrillary tangles in CA1 was not an independent predictor of suicide status in the statistical analysis (p =.16), although the distribution was more highly skewed among the cases (75th percentile of 10.5 for cases, vs. 2 for control subjects).

CONCLUSIONS

Severe Alzheimer's disease pathology is overrepresented in elderly patients who complete suicide.

Level of minimal residual disease after consolidation therapy predicts outcome in acute myeloid leukemia

We used flow cytometry to quantify minimal residual disease (MRD) in 56 patients with acute myeloid leukemia (AML) expressing a leukemia-associated phenotype. Thirty-four patients aged 18 to 60 years were entered into the AML-10 protocol (induction, consolidation, and autologous stem-cell transplantation [ASCT]), whereas 22 patients older than 60 years received the AML-13 protocol (induction, consolidation, and consolidation II). After induction, the level of MRD that was best associated with treatment outcome was 4.5 x 10(-4) residual leukemic cells. However, the outcome in patients with at least 4.5 x 10(-4) cells (n = 26) was not significantly different from that in patients with fewer leukemic cells (n = 30); there were 15 (58%) relapses in the first group and 12 (40%) relapses in the second. After consolidation, the most predictive MRD cutoff value was 3.5 x 10(-4) cells: 22 patients had an MRD level of 3.5 x 10(-4) cells or higher and 17 (77%) of these patients had relapse, compared with 5 of 29 patients (17%) with lower MRD levels (P <.001). An MRD level of 3.5 x 10(-4) cells or higher after consolidation was significantly correlated with poor or intermediate-risk cytogenetic findings, a multidrug resistance 1 (MDR1) phenotype, short duration of overall survival, and short duration of relapse-free survival (P =.014,.031,.00022, and.00014, respectively). In multivariate analysis, this MRD status was significantly associated with a high frequency of relapse (P <.001) and a short duration of overall (P =.025) and relapse-free survival (P =.007). ASCT did not alter the prognostic effect of high MRD levels after consolidation: the relapse rate after transplantation was 70%. Thus, we found that an MRD level of 3.5 x 10(-4) cells or higher at the end of consolidation strongly predicts relapse and is significantly associated with an MDR1 phenotype and intermediate or unfavorable cytogenetic findings. (Blood. 2000;96:3948-3952)

Synthetic catalysis of amide isomerization

Rotation about the C-N bond in amides can be catalyzed by Bronsted and Lewis acids, as well as nucleophiles and bases. Catalysis of amide isomerization occurs in biological systems via "rotamase" enzymes; however, the mechanisms by which these proteins operate are not completely understood. We outline investigations that provide experimental support for mechanisms believed to be feasible for the catalysis of amide isomerization and present practical applications that have resulted from this work.

Synthesis of the functionalized tricyclic core of lactonamycin by oxidative dearomatization

[reaction: see text] We report in this Letter a synthesis of the densely oxygenated CDEF ring system (27) corresponding to that found in the recently discovered antibiotic lactonamycin. The key steps in the synthesis consist of an intramolecular Wessely oxidative lactonization of acid 18, followed by a hydroxyl-directed epoxidation of enol ether 21.

Synthesis of the functionalized tricyclic core of lactonamycin by oxidative dearomatization

[reaction: see text] We report in this Letter a synthesis of the densely oxygenated CDEF ring system (27) corresponding to that found in the recently discovered antibiotic lactonamycin. The key steps in the synthesis consist of an intramolecular Wessely oxidative lactonization of acid 18, followed by a hydroxyl-directed epoxidation of enol ether 21.

Gynaecological and obstetrical morbidity in women with type I von Willebrand disease: results of a patient survey

Type 1 von Willebrand disease (vWD) is generally regarded clinically as 'mild' and the obstetrical-gynaecological features have not been fully described. We administered a patient questionnaire and provider survey of the medical and quality of life aspects of childbirth and menstruation to 99 type 1 vWD patients and compared the patients presently menstruating (n=81) to a cohort of 150 menstruating females in the general population. The following measurements had a statistically higher proportion in the vWD group: number of tampons/towels used for a typical menstrual cycle (P=0. 002); percentage reporting that clothes are stained by menses (P = 0. 001); past or present history of anaemia (P = 0.001); childbirth-related bleeding (P=0.001); and childbirth-related bleeding necessitating RBC transfusion (P=0.002). Quality of life assessment of the impact of menses in both of the above cohorts was measured by a Likert scale using seven quality of life parameters. Compared to the control group, the vWD patients had a significantly higher score, with P-values of < 0.0001 for each parameter. Hormonal interventions for menorrhagia in the vWD patients were < or = 50% effective. Menorrhagia resulted in red blood cell transfusions in 6% of patients, dilatation and curettage in 17% and hysterectomy in 13%. Despite the common connotation of type 1 vWD as clinically 'mild', childbirth and the monthly challenge to haemostasis presented by menstruation result in a substantial degree of morbidity in females with type 1 vWD. These results support the rationale for ongoing international efforts to increase awareness of vWD as a cause for menorrhagia and to improve the quality of life in females with known vWD.

An evaluation of the management of patients with sore throats by practice nurses and GPs

BACKGROUND

Practice nurses are increasingly involved in the management of minor illnesses in primary care. However, there has been little work published that evaluates the quality of the service they offer to patients. In our practice (semi-rural, 14,000 patients) a nursing triage system for minor illnesses has been established since 1992.

AIM

To compare the quality of management of sore throats by practice nurses and general practitioners (GPs) in a routine nursing triage system.

METHOD

An observational study assessing all patients over the age of two years presenting over a six-month period (February-August 1997) to either the practice nurse or GP with a sore throat as the chief presenting complaint. Patients were followed up at five to seven days by a researcher and recovery rates, analgesic requirements, reconsultation rates, and satisfaction rates were recorded. Patients who were still symptomatic at five to seven days were followed up again at 28 days and outcomes recorded.

RESULTS

A total of 44% of patients consulted the practice nurse and 56% consulted the GP. Severity of presenting illness was similar in the two groups. The number of patients whose sore throats had settled, reconsultation rates, antibiotic prescription, and dissatisfaction rates were the same for both groups. However, the patients consulting the nurse had a more favourable outcome on indices such as patients' perception of being back to normal health (64% versus 53%) and median number of days for the sore throat to settle (four versus five). Nurses tended to see younger patients (mean age = 22.5 years versus 28.3 years) and more patients seeing the practice nurse recalled receiving advice about home remedies (76% versus 54%).

CONCLUSION

Practice nurses can establish a safe and effective service for treatment of sore throats in a time-restricted triage system.

Association between methylmercury exposure from fish consumption and child development at five and a half years of age in the Seychelles Child Development Study: an evaluation of nonlinear relationships

Studies to date of the developmental effects of pre- and postnatal methylmercury exposure from fish consumption in the Seychelles Islands, using linear regression models for analysis, have not shown adverse effects on neurodevelopmental test scores. In this study we evaluated whether nonlinear effects of methylmercury exposure were present, using scores on six tests administered to cohort children in the Seychelles Child Development Study at 66 months of age. Prenatal exposure was determined by measuring mercury in a segment of maternal scalp hair representing growth during pregnancy. Postnatal exposure was measured in a segment of the child's hair taken at 66-months of age. Generalized additive models (GAMs), which make no assumptions about the functional form of the relationship between exposure and test score, were used in the analysis. GAMs similar to the original linear regression models were used to reanalyze the six primary developmental endpoints from the 66-month test battery. Small nonlinearities were identified in the relationships between prenatal exposure and the Preschool Language Scale (PLS) Total score and Child Behavior Check List (CBCL) and between postnatal exposure and the McCarthy General Cognitive Index (GCI) test scores. The effects are best described graphically but can be summarized by computing the change in the predicted test score from 0 to either 10 or 15 ppm and then above this point. For the PLS the trend involved a decline of 0.8 points between 0 and 10 ppm followed by an increase (representing improvement) of 1.3 points above 10 ppm. For the CBCL there was an increase of 1 point from 0 to 15 ppm, and then a decline (improvement) of 4 points above 15 ppm. The GCI increased by 1.8 points through 10 ppm and then declined 3.2 points (representing worse performance) above 10 ppm. These results are not entirely consistent. Two of the trends involve what appear to be beneficial effects of prenatal exposure. The one possibly adverse trend involves postnatal exposure. In every case the trend changes direction, so that an effect in one direction is followed by an effect in the opposite direction. Because of the descriptive nature of GAMs it is difficult to provide a precise level of statistical significance for the estimated trends. Certainly above 10 ppm there is less data and trends above this level are estimated less precisely. Overall there was no clear evidence for consistent (across the entire range of exposure levels) adverse effects of exposure on the six developmental outcomes. Further nonlinear modeling of these data may be appropriate, but there is also the risk of fitting complex models without a clear biological rationale.

Ozone, but not nitrogen dioxide, exposure decreases glutathione peroxidases in epithelial lining fluid of human lung

Antioxidants, such as glutathione peroxidases (GPxs), in epithelial lining fluid (ELF) protect against health effects of oxidant pollutants, which includes O(3) or NO(2). We hypothesized that GPxs concentration in ELF is responsive to O(3) or NO(2) exposure. Subjects underwent two 4-h exposures to O(3) (0.22 ppm) and one to air. In another experiment, subjects underwent 3-h exposures to air and NO(2) (0.6 and 1.5 ppm). Bronchoalveolar lavage (BAL) was performed immediately or 18 h after O(3) exposure and 3.5 h after each NO(2) exposure. GPx activity and extracellular GPx (eGPx) protein concentrations were determined in ELF, and their relationships to markers of lung function, inflammation, and epithelial permeability were examined. Although the total amounts were not changed, basal (air) GPx activity (223.6 +/- 24.4 mU/ml), basal eGPx protein concentration (2.62 +/- 0.25 microg/ml), and basal ELF dilution factor (152.3 +/- 8.4) decreased 40% immediately after O(3) exposure and remained 30% decreased 18 h after exposure (p = 0.0001). No effect of NO(2) exposure on GPxs concentration was detected. There was an inverse correlation between baseline ELF eGPx protein concentration and the change in PMN 18 h after O(3) exposure (p = 0.04). Thus, O(3), a strong oxidant, decreases both GPx activity and eGPx protein in ELF, whereas NO(2), a weaker oxidant, does not. eGPx in ELF may protect against O(3)-induced airway inflammation.