Risk Factors for Venous Thromboembolism After Lung Transplantation

BACKGROUND

The risk factors for venous thromboembolism (VTE) following lung transplantation are not well established. We aimed to estimate the incidence of VTE and to identify the risk factors for VTE after lung transplantation.

METHODS

We performed a nested case-control study within the cohort of 121 patients who underwent lung transplantation at our center between August 2001 and July 2005. Control subjects were matched to case patients on the number of days from the time of transplant. Cox proportional hazards models were used to identify risk factors for VTE.

RESULTS

Twenty-four patients had deep vein thromboses, and 6 patients had pulmonary emboli (3 patients had both) [22% of the cohort]. In multivariate models, older age (p < 0.05), diabetes mellitus (p = 0.03), and pneumonia (p = 0.02) were associated with a higher rate of VTE.

CONCLUSIONS

VTE is a frequent complication of lung transplantation. Older age, diabetes, and pneumonia increase the rate of VTE. Future studies of intensive VTE prophylaxis may be warranted.

Racial and ethnic disparities in idiopathic pulmonary fibrosis: A UNOS/OPTN database analysis

We previously reported poorer survival among non-Hispanic blacks and Hispanics with idiopathic pulmonary fibrosis (IPF) compared to non-Hispanic whites at our center. In the current study, we hypothesized that these disparities would exist in a nationwide cohort of wait-listed patients with IPF. We performed a retrospective cohort study of 2635 patients with IPF listed for lung transplantation between 1995 and 2003 at 94 transplant centers in the United States. The age-adjusted mortality rate was higher among non-Hispanic blacks [hazard ratio (HR) = 1.24, 95% confidence interval (CI) 1.06-1.45, p = 0.009] and Hispanics (HR = 1.29, 95% CI 1.06-1.56, p = 0.01) compared to non-Hispanic whites. These findings persisted after adjustment for transplantation, medical comorbidities and socioeconomic status. Worse lung function at the time of listing appeared to explain some of these differences (HR for non-Hispanic blacks after adjustment for forced vital capacity percent predicted = 1.16, 95% CI 0.98-1.36, p = 0.09; HR for Hispanics = 1.21, 95% CI 0.99-1.48, p = 0.056). In summary, black and Hispanic patients with IPF have worse survival than whites after listing for lung transplant.

Estimating and Comparing the Distribution of Onset of Disease from Prevalence Case-Control Data

Age at ascertainment from prevalence case-control data identifies the age-specific odds of disease. When age at onset is available from the cases, the conditional distribution of age at onset, given that disease occurs, is identifiable. Combining both kinds of information by introducing a multiplicative intercept allows identification of the marginal distribution of age at onset. Here, the approach is extended to the two-sample setting through a generalization of the multiplicative intercept model. The efficiency of the approach is explored and a test statistic based on the integrated difference between distribution function estimates is proposed. An approach to regularization of the likelihood is discussed. The methods are illustrated through an application to data on colorectal polyps obtained from a case-control study of individuals undergoing colonoscopy.

New approach to the statistical analysis of cardiovascular data

Fourier-based approaches to analysis of variability of R-R intervals or blood pressure typically compute power in a given frequency band (e.g., 0.01–0.07 Hz) by aggregating the power at each constituent frequency within that band. This paper describes a new approach to the analysis of these data. We propose to partition the blood pressure variability spectrum into more narrow components by computing power in 0.01-Hz-wide bands. Therefore, instead of a single measure of variability in a specific frequency interval, we obtain several measurements. The approach generates a more complex data structure that requires a careful account of the nested repeated measures. We briefly describe a statistical methodology based on generalized estimating equations that suitably handles this more complex data structure. To illustrate the methods, we consider systolic blood pressure data collected during psychological and orthostatic challenge. We compare the results with those obtained using the conventional methods to compute blood pressure variability, and we show that our approach yields more efficient results and more powerful statistical tests. We conclude that this approach may allow a more thorough analysis of cardiovascular parameters that are measured under different experimental conditions, such as blood pressure or heart rate variability.

Religious attendance as a predictor of survival in the EPESE cohorts

BACKGROUND

Interest has arisen in recent years in the relationship between religious involvement and health outcomes. Although most of the early literature consists of studies with methodological flaws, some recent well-conducted reports show that religious attendance is associated with reduced mortality in selected subgroups and populations.

METHODS

In this study, we investigated the relationship between religious attendance and mortality using the 14,456 participants in the National Institute of Aging-funded 'Established Populations for Epidemiologic Studies of the Elderly'.

RESULTS

Our analyses show that after controlling for important prognostic factors, frequent religious attendance was associated with increased survival in the entire cohort [risk ratio (RR) = 0.78, 95% Confidence interval (CI) 0.70-0.88]. However, stratified analyses show that this association exists for only two of the four sites.

CONCLUSIONS

We conclude that the association between religious attendance and survival is not robust and may depend upon unknown confounders and covariates.

Role of TAP-1 and/or TAP-2 antigen presentation defects in tumorigenicity of mouse melanoma

Mutations in transporters associated with antigen processing (TAP-1 and -2) required for the transport of cytosolic endogenous peptides to the endoplasmic reticulum correlate with increased metastatic potential and reduced host survival in several malignancies. To address the possible function of TAP as a "tumor suppressor" gene, we show that correction of TAP-1 and/or TAP-2 defects in B16 mouse melanoma enhanced the cell surface expression of MHC class I molecules and significantly reduced the rate of subcutaneous tumor growth and pulmonary metastatic burden. Cytotoxic assays confirmed increased sensitivity of TAP-1 and/or TAP-2 transfected clones of B16 melanoma to cytotoxic T lymphocytes. These results indicate that the expression of TAP limits the malignant potential of tumors with implications for CD8(+) T cell-based immunotherapy in controlling growth of certain TAP-deficient malignancies.

A phase II trial of temozolomide in patients with unresectable or metastatic soft tissue sarcoma

BACKGROUND

The objective of this study was to assess the efficacy and toxicity of the imidazotetrazine derivative temozolomide for patients with unresectable or metastatic soft tissue sarcoma.

METHODS

Twenty-five of 26 patients were eligible and assessable for toxicity and response. Temozolomide was administered twice daily on a 12-hour schedule for 5 days as an oral bolus dose of 200 mg/m(2) followed by 9 doses of 90 mg/m(2) every 4 weeks.

RESULTS

There were 2 partial responses, 2 mixed responses, and 3 patients with stable disease that lasted > 6 months, for an overall objective response rate of 8%. At a median follow-up of 13.2 months, the median progression-free survival and the median overall survival were 2.0 months (95% confidence interval [95% CI], 1.7-2.3) and 13.2 months (95% CI, 4.7-31.1), respectively. All responding patients had leiomyosarcoma of uterine or nonuterine origin; and, in a subset analysis of these patients, the objective response rate was 18% (2 of 11 patients), with disease stabilization occurring in 3 of 11 patients (27%). For this subgroup, at a median follow-up of 24.4 months, the median progression-free survival and the median overall survival were 3.9 months (95% CI, 1.9-21.9) and 30.8 months (lower-bound 95% CI, 7.8), respectively. There were no treatment-related deaths or National Cancer Institute Grade 4 toxicities. Grade 3 toxicities included nausea, anemia, fatigue, elevated alkaline phosphatase levels and nonneutropenic fever (1 patient each).

CONCLUSIONS

Temozolomide at the dose schedule employed in the current study was tolerated well and had modest activity against previously treated unresectable or metastatic leiomyosarcoma of both uterine and nonuterine origin.

Hostility, interpersonal interactions, and ambulatory blood pressure

OBJECTIVE

This study examined aspects of the transactional model of hostility and health by investigating relationships among hostility, interpersonal interactions, and ambulatory blood pressure in a healthy community sample.

MATERIALS AND METHODS

Participants included 65 female and 39 male healthy adults between the ages of 18 and 46 years. Ambulatory blood pressure (ABP) and diary data on mood and social interactions were obtained every 20 minutes for 1 day. Mixed models regression analyses were used to evaluate the relationships among hostility, interpersonal interactions, and ABP.

RESULTS

Trait hostility was positively associated with the frequency and intensity of negative interactions and was negatively associated with the frequency and intensity of positive interactions. Interacting with others was associated with increases in systolic blood pressure (SBP) and diastolic blood pressure (DBP). The magnitude of the increase in blood pressure was positively associated with the degree to which the interaction was perceived as negative. Hostility was not directly associated with ABP/heart rate (HR) or ABP/HR responses during any interactions or negative interactions. However, there was an interaction between hostility and negative interaction intensity for DBP, suggesting that hostility moderates the effects of negative interactions on DBP. Specifically, increases in the intensity of negative interactions were associated with increases in DBP for participants with high, but not low, hostility.

CONCLUSIONS

The results provide partial support for the notion that hostility may be associated with risk for cardiovascular disease through its effects on interpersonal interactions and their cardiovascular correlates.

Deriving heart period variability from blood pressure waveforms

International standards for calculating heart period variability (HPV) from a series of R-wave intervals (R-R) in an electrocardiographic (ECG) recording have been widely accepted. It is possible, and potentially useful in various settings, to use systolic blood pressure waveform intervals to estimate HPV, but the validity of HPV derived from blood pressure (BP) waveforms has not been established. To test the reliability between BP- and ECG-derived HPV indexes, we evaluated data from 234 healthy adults in four studies of HPV reactivity to stress. Study conditions included resting baseline, arithmetic, Stroop test, speech presentation, and orthostatic tilt. Continuous ECG and BP recordings were sampled at a rate of 500 Hz, scored by the same methods, and used to calculate heart rate and time- and frequency-domain measures of HPV. Overall, reliability between the two methods was very high for computing heart rate and HPV indexes. High-frequency HPV indexes were somewhat less reliably computed. In conclusion, in healthy adults, with the use of appropriate methods, BP waveforms can produce reliable indexes of HPV.

The efficacy of curettage in delineating margins of basal cell carcinoma before Mohs micrographic surgery

BACKGROUND

Curettage may be helpful as a preliminary step to outline the gross subclinical extensions of high-risk basal cell carcinomas (BCCs) before the first stage of Mohs micrographic surgery. Although many Mohs surgeons use curettage in the Mohs surgical setting, no prospective studies have as yet been performed that demonstrate the efficacy of curettage in delineating tumor margins before Mohs surgery.

OBJECTIVE

To document the efficacy of curettage in delineating BCC margins before Mohs micrographic surgery.

METHODS

This was a prospective evaluation of 599 patients with biopsy-proven BCCs treated with Mohs surgery. The preoperative dimensions of each tumor, the curetted dimensions before the first surgical stage, the proposed excisional margins before each surgical stage, and the final defect dimensions after each surgical stage were measured. The maximum curetted margin around each tumor was calculated and compared with typical Mohs excisional margins of 1, 2, 3, and 4 mm. A hypothetical 1-, 2-, 3-, or 4-mm excisional margin was added to the preoperative X and Y dimensions of each tumor, and the actual final defect sizes were compared with the hypothetical final defect sizes to determine whether an additional surgical stage would have been needed had curettage not been performed. The amount of tissue stretch occurring after specimen removal was calculated to determine whether tissue stretch falsely elevated the number of instances in which an additional surgical stage would have been needed had curettage not been performed.

RESULTS

The curetted margin around the observed extent of each tumor exceeded 1 mm in 87.6% of cases, 2 mm in 47.1% of cases, 3 mm in 19.7% of cases, and 4 mm in 5.7% of cases. The mean curetted margin was 1.7 mm. Taking a 1-mm margin in the first stage of Mohs surgery without first performing curettage would have necessitated an extra surgical stage in 99.2% of cases, whereas taking a 2-, 3-, or 4-mm margin would have necessitated an extra surgical stage in 93.0%, 88.1%, and 49.4% of cases, respectively. After calculating and eliminating the effects of tissue stretch, it was found that a 1-mm excisional margin taken in the first stage of Mohs surgery without first performing curettage would have necessitated an extra surgical stage in 99.0% of the cases. Taking a 2-, 3-, or 4-mm margin would have necessitated an extra surgical stage in 87.5%, 57.9%, and 29.5% of cases, respectively.

CONCLUSION

Careful debulking and palpation with the curette significantly reduce the number of Mohs surgical stages required for BCC clearance. Even after taking the effects of tissue stretch into consideration, a significant proportion of tumors would still require an additional stage for tumor clearance without aggressive presurgical curettage.

Maternal effects in infant and adult phenotypes of 5HT1A and 5HT1B receptor knockout mice

The influence of the pre- and postweaning maternal environment on the offspring's phenotype was examined in 5-HT1A and 5-HT1B receptor knockout mice (KO1A and KO1B, respectively). We have previously shown that, when born to and raised by homozygous dams of the same genotype, adult KO1A are more anxious than wild-type (WT) mice, and adult KO1B are hyperactive and slightly less anxious than WT mice. We extend our studies here to the behavioral results of the offspring's own genotype, when the dam's genotype is constant, and the effects of the dam's genotype when the offspring's genotype is constant. In Experiments 1 and 2, KO1A-/- pups produced less ultrasonic vocalizations (USV) than controls in an isolation test on postnatal Day 7 when born to and reared by KO1A dams, either -/- or +/-. Heterozygous F1 pups reared by KO1A-/- dams produced more USV and were less anxious in the plus-maze at 2 to 3 months of age than F1 pups born to and reared by WT dams (Experiment 3). F1 pups reared by KO1B-/- dams produced less USV and were more anxious in the plus-maze than F1 pups reared by WT dams (Experiment 4). The results support a role for maternal effects that may comprise direct effects such as the dam's behavior and nutritional care of the pup, and possibly more complex indirect effects through the establishment of idiosyncratic dam-pup dyadic interactions. We recommend that breeding techniques that rely on same genotype (mutant-mutant or WT-WT) breeding pairs not be used to generate offspring when the focus of research is the study of gene function, but rather when familial effects need to be studied.

Claims about religious involvement and health outcomes

Claims about religion, spirituality, and health have recently appeared with increasing frequency, in both the popular media and professional journals. These claims have asserted that there are a great many studies in the literature that have examined relations between religious involvement and health outcomes and that the majority of them have shown that religious people are healthier. We examined the validity of these claims in two ways: (a) To determine the percentage of articles in the literature that were potentially relevant to such a claim, we identified all English-language articles with published abstracts identified by a Medline search using the search term religion in the year 2000, and (b) to examine the quality of the data in articles cited as providing supportfor such a claim, we examined all articles in the area of cardiovascular disease and hypertension cited by two comprehensive reviews of the literature. Of the 266 articles published in the year 2000 and identified by the Medline search, only 17% were relevant to claims of health benefits associated with religious involvement. About half of the articles cited in the comprehensive reviews were irrelevant to these claims. Of those that actually were relevant, many either had significant methodological flaws or were misrepresented, leaving only afew articles that could truly be described as demonstrating beneficial effects of religious involvement. We conclude that there is little empirical basis for assertions that religious involvement or activity is associated with beneficial health outcomes.

Long-term mortality after a first episode of status epilepticus

OBJECTIVE

To evaluate long-term mortality among people with status epilepticus (SE).

METHODS

The authors performed a population-based retrospective cohort study to determine long-term mortality after SE. Between January 1, 1965, and December 31, 1984, all first episodes of SE receiving medical attention were ascertained through the Rochester Epidemiology Project Records-Linkage System. Cases surviving the first 30 days (n = 145) were followed until death or study termination (February 1996).

RESULTS

At 10 years, cumulative mortality among 30-day survivors was 43%. The standardized mortality ratio (SMR) at 10 years was 2.8 (95% CI, 2.1-3.5). The mortality rate of those with idiopathic/cryptogenic SE was not increased (SMR = 1.1; 95% CI, 0.5-2.3). The following characteristics of SE increased long-term risk for mortality: SE > or = 24 hours in duration vs. SE < 2 hours (relative risk [RR] = 2.3; 95% CI, 1.1-5.1); acute symptomatic etiology vs idiopathic/cryptogenic etiology (RR = 2.2; 95% CI, 1.0-5.1) SE; myoclonic SE vs generalized convulsive SE (RR = 4.0; 95% CI, 1.3-13).

CONCLUSION

Forty percent of subjects who survived the first 30 days after an incident episode of SE die within the next 10 years. The long-term mortality rate was threefold that of the general population over the same time period. The long-term mortality rate at 10 years was worse for those with myoclonic SE, for those who presented with SE lasting more than 24 hours, and for those with acute symptomatic SE. The long-term mortality rate was not altered in those with idiopathic/cryptogenic SE. We conclude that SE alone does not modify long-term mortality.

Endobronchial brachytherapy and external-beam radiotherapy in patients with endobronchial obstruction and extrabronchial extension

PURPOSE

To evaluate the efficacy of high-dose rate endobronchial brachytherapy (HDR-EB) with concomitant short-course external-beam radiotherapy (EBRT) in patients with both endobronchial and extrabronchial tumor.

METHODS AND MATERIALS

Patients with endobronchial disease and extrabronchial lesions greater than 2.5cm were treated with three 5Gy HDR-EB and 37.5Gy EBRT delivered over 3.5 weeks. Flexible fiberoptic bronchoscopy was performed with the patient under conscious sedation, and tumor location, length of lesion, percentage of lumen occlusion, and presence of bleeding were recorded. Fluoroscopic visualization of the guide wire in the catheter tip assisted in demarcating the proximal and distal extent of the intraluminal tumor. 5Gy was prescribed to a distance of 1cm from the catheter and a computerized treatment planning system was used to optimize the dose distribution to the gross target volume with 1.5-2cm margins at the distal and proximal ends. Bronchoscopic and symptomatic response rates were assessed at the third HDR-EB and patients were seen in follow-up every 2 months.

RESULTS

One hundred seventeen endobronchial treatments were delivered to 33 patients with primary carcinoma, and 8 patients with metastatic carcinoma. The median age was 69 (range = 36-94); 95% reported dyspnea; 71% cough and 22% hemoptysis. Seventy-two percent of patients reported resolution of their symptoms and 54% achieved a bronchoscopic response (at least 50% decrease in intraluminal obstruction). In a multivariate logistic model including stage, age, primary tumor type, and Karnofsky performance status (KPS) as predictors, only KPS was statistically associated with bronchoscopic response (OR = 1.1; 95%CI = 1.01-1.13) and palliation of symptoms (OR = 1.3; 95%CI = 1.05-1.59). The overall median survival was 5.2 months and was associated with bronchoscopic response (11 months in responders vs 4 in nonresponders) and symptom resolution (8 months in responders vs 1.5 in nonresponders). In a multivariate Cox survival model with stage, age, primary tumor type, and KPS as predictors, only KPS was significantly associated with survival (RR = 0.92;95%CI = 0.88-0.95).

CONCLUSIONS

HDR-EB with concomitant EBRT is an effective treatment regimen for patients with both endobronchial and extrabronchial tumor. Patients with higher performance status are more likely to have resolution of disease and have longer median survival.

Relation between depression after coronary artery bypass surgery and 12-month outcome: a prospective study

BACKGROUND

The association of depression with cardiac events has been investigated mainly in community cohorts, in patients undergoing catheterisation, or in patients who have had myocardial infarction. We have assessed the effect of depression on outcomes after coronary artery bypass graft (CABG) surgery.

METHODS

In a prospective study, we followed up for 1 year 207 men and 102 women, who had undergone coronary artery bypass graft surgery. We assessed depression with a structured psychiatric interview (diagnostic interview schedule) and a questionnaire (Beck depression inventory) before discharge. Cardiac events included angina or heart failure that needed admission to hospital, myocardial infarction, cardiac arrest, percutaneous transluminal coronary angioplasty, repeat CABG, and cardiac mortality. Non-cardiac events consisted of all other reasons for mortality or readmission.

FINDINGS

63 patients (20%) met modified diagnostic statistical manual IV criteria for major depressive disorder. At 12 months, 17 (27%) of these patients had a cardiac event compared with 25 of 246 (10%) who were not depressed (p<0.0008). Five variables had significant univariate associations with cardiac events: sex, living alone, low ejection fraction (<0.35), length of hospital stay, and depression. In a Cox proportional-hazard model with these five and two other variables of cardiac severity, major depressive disorder (risk ratio 2.3 [95% CI 1.17-4.56]), low ejection fraction (2.3 [1.07-5.03]), and female sex (2.4 [1.24-4.44]) were associated with adverse outcomes. Depression did not predict deaths or admissions for non-cardiac events.

INTERPRETATION

Depression is an important independent risk factor for cardiac events after CABG surgery.

Salvage cryotherapy using an argon based system for locally recurrent prostate cancer after radiation therapy: the Columbia experience

PURPOSE

Cryosurgical ablation of the prostate has been reported as potential treatment for radioresistant clinically localized prostate cancer. We report our experience with the safety and efficacy of salvage cryosurgery using the argon based CRYOCare system (Endocare, Inc, Irvine, California).

MATERIALS AND METHODS

Between October 1997 and September 2000, 38 men with a mean age of 71.9 years underwent salvage cryosurgery for recurrent prostate cancer after radiation therapy failed. All patients had biochemical disease recurrence, defined as an increase in prostate specific antigen (PSA) of greater than 0.3 ng./ml. above the post-radiation PSA nadir. Subsequently prostate biopsy was positive for cancer. Pre-cryosurgery bone scan demonstrated no evidence of metastatic disease. In addition, these patients received 3 months of neoadjuvant androgen deprivation therapy before cryotherapy.

RESULTS

The PSA nadir was 0.1 or less, 1 or less and greater than 1 ng./ml. in 31 (81.5%), 5 (13.2%) and 2 (5.3%) patients, respectively. Biochemical recurrence-free survival calculated from Kaplan-Meier curves was 86% at 1 year and 74% at 2 years. Reported complications included rectal pain in 39.5% of cases, urinary tract infection in 2.6%, incontinence in 7.9%, hematuria in 7.9% and scrotal edema in 10.5%. The rate of rectourethral fistula, urethral sloughing and urinary retention was 0%.

CONCLUSIONS

Our study supports cryosurgery of the prostate as safe and effective treatment in patients in whom radiation therapy fails. Using the CRYOCare machine resulted in a marked decrease in complications.

Predicting analysis times in randomized clinical trials

Randomized clinical trial designs commonly include one or more planned interim analyses. At these times an external monitoring committee reviews the accumulated data and determines whether it is scientifically and ethically appropriate for the study to continue. With failure-time endpoints, it is common to schedule analyses at the times of occurrence of specified landmark events, such as the 50th event, the 100th event, and so on. Because interim analyses can impose considerable logistical burdens, it is worthwhile predicting their timing as accurately as possible. We describe two model-based methods for making such predictions during the course of a trial. First, we obtain a point prediction by extrapolating the cumulative mortality into the future and selecting the date when the expected number of deaths is equal to the landmark number. Second, we use a Bayesian simulation scheme to generate a predictive distribution of milestone times; prediction intervals are quantiles of this distribution. We illustrate our method with an analysis of data from a trial of immunotherapy in the treatment of chronic granulomatous disease.

Enhanced stress reactivity in paediatric anxiety disorders: implications for future cardiovascular health

The aim was to clarify the developmental nature of associations between psychiatric illness and risk for cardiovascular disease by investigating differences in cardiac functioning between youth with anxiety disorders and healthy controls. Twenty-two children meeting DSM-IV criteria for either separation anxiety disorder, overanxious disorder, panic disorder/panic attacks, or social phobia and 12 healthy controls underwent continuous electrocardiogram and respiration rate monitoring during a 15 min baseline period and 15 min of exposure to 5% CO(2). Heart rate (HR) and high frequency heart rate variability (HRV), a non-invasive measure of cardiac parasympathetic control, were calculated. Youth with anxiety disorders had higher and less fluctuating HR during baseline. Data also suggested that probands showed diminished overall changes in HRV during baseline and CO(2) inhalation relative to controls. However, as respiration rate affects HRV, these findings were confounded by changes in respiration elicited by CO(2) inhalation. The data suggest that youth with anxiety disorders experience an elevated and less fluctuating HR in the face of a novel situation, possibly due to a failure to appropriately modulate HRV. In adults, sustained elevations in HR in conjunction with deficient vagal modulation predicts risk for future cardiovascular disease. As such, the current data suggest that the presence of an anxiety disorder may identify youth who exhibit autonomic profiles that place them at risk for cardiac disease.

Reduction of paclitaxel-induced peripheral neuropathy with glutamine

PURPOSE

Dose-limiting toxicity of many newer chemotherapeutic agents is peripheral neuropathy. Prior attempts to reduce this side effect have been unsuccessful. We report on the possible successful reduction of peripheral neuropathy with glutamine administration after high-dose paclitaxel.

EXPERIMENTAL DESIGN

Patients entered a high-dose chemotherapy protocol in which the first high-dose cycle was paclitaxel at 825 mg/m(2) given over 24 h. The first cohort of patients did not receive glutamine, and the second cohort of patients received glutamine at 10 g orally three times a day for 4 days starting 24 h after completion of paclitaxel. Neurological assessment was performed at baseline, and at least 2 weeks after paclitaxel, and consisted of a complete neurological exam and nerve conduction studies.

RESULTS

There were paired pre- and post-paclitaxel evaluations on 33 patients who did not receive glutamine and 12 patients who did. The median interval between pre- and post-exams was 32 days. For patients who received glutamine, there was a statistically significant reduction in the severity of peripheral neuropathy as measured by development of moderate to severe dysesthesias and numbness in the fingers and toes (P < 0.05). The degree and incidence of motor weakness was reduced (56 versus 25%; P = 0.04) as well as deterioration in gait (85 versus 45%; P = 0.016) and interference with activities of daily living (85 versus 27%; P = 0.001). Moderate to severe paresthesias in the fingers and toes were also reduced (55 versus 42% and 64 versus 50%, respectively), although this value was not statistically significant. All of these toxicities were reversible over time.

CONCLUSIONS

Glutamine may reduce the severity of peripheral neuropathy associated with high-dose paclitaxel; however, results from randomized, placebo-controlled clinical trials will be needed to fully assess its impact, if any. Trials are currently ongoing to assess its efficacy for standard-dose paclitaxel in breast cancer and other tumors for which peripheral neuropathy is the dose-limiting toxicity.

Hostility, gender, and cardiac autonomic control

OBJECTIVE

Although considerable evidence implicates hostility in the development of coronary artery disease (CAD), the pathogenic mechanisms remain poorly understood. We have developed a psychophysiological model that holds that altered autonomic nervous system function links psychological traits with CAD outcomes. In laboratory studies, stressors reduce high-frequency (HF) heart period variability, an index of cardiac vagal modulation. With ambulatory electrocardiographic recording, we demonstrated in a predominantly male sample that hostility was inversely associated with HF power, but only during waking hours. These findings are consistent with the hypothesis that hostile individuals experience multiple stressful interpersonal transactions each day, resulting in overall lower HF power during the day but not at night.

METHODS

To further evaluate this hypothesis, we screened 96 subjects using the Cook-Medley Hostility Scale and selected 15 men and 15 women representing a wide distribution of hostility. These subjects were studied in a laboratory session assessing reactivity to psychological and orthostatic challenges with continuous electrocardiographic, blood pressure, and respiration monitoring. We predicted that for men and women, hostility would be inversely related to reductions in HF power in response to challenge.

RESULTS

In response to mental stressors, all measures of heart period variability change were inversely related to hostility as predicted. No such relationships were found for responses to tilt. The data suggested a possible effect of gender on these relationships.

CONCLUSIONS

These data add to the growing body of evidence showing that hostility influences vagal modulation of the cardiovascular system and suggest that altered autonomic control is a pathogenic mechanism linking hostility and CAD.