Reduced submaximal leg blood flow after high-intensity aerobic training

This study evaluated the hypothesis that active muscle blood flow is lower during exercise at a given submaximal power output after aerobic conditioning as a result of unchanged cardiac output and blunted splanchnic vasoconstriction. Eight untrained subjects (4 men, 4 women, 23-31 yr) performed high-intensity aerobic training for 9-12 wk. Leg blood flow (femoral vein thermodilution), splanchnic blood flow (indocyanine green clearance), cardiac output (acetylene rebreathing), whole body O(2) uptake (VO(2)), and arterial-venous blood gases were measured before and after training at identical submaximal power outputs (70 and 140 W; upright 2-leg cycling). Training increased (P < 0.05) peak VO(2) (12-36%) but did not significantly change submaximal VO(2) or cardiac output. Leg blood flow during both submaximal power outputs averaged 18% lower after training (P = 0.001; n = 7), but these reductions were not correlated with changes in splanchnic vasoconstriction. Submaximal leg VO(2) was also lower after training. These findings support the hypothesis that aerobic training reduces active muscle blood flow at a given submaximal power output. However, changes in leg and splanchnic blood flow resulting from high-intensity training may not be causally linked.

CD8 binding to MHC class I molecules is influenced by T cell maturation and glycosylation

CD8 serves both as an adhesion molecule for class I MHC molecules and as a coreceptor with the TCR for T cell activation. Here we study the developmental regulation of CD8-mediated binding to noncognate peptide/MHC ligands (i.e., those not bound by the TCR). We show that CD8's ability to bind soluble class I MHC tetramers and to mediate T cell adhesion under shear flow conditions diminishes as double-positive thymocytes mature into CD8(+) T cells. Furthermore, we provide evidence that this decreased CD8 binding results from increased T cell sialylation upon T cell maturation. These data suggest that CD8's ability to interact with class I MHC is not fixed and is developmentally regulated through the T cell's glycosylation state.

Survival after conservative (palliative) management of pleural malignant mesothelioma

BACKGROUND AND OBJECTIVES

Malignant mesothelioma is a lethal disease. Aggressive multimodality treatment protocols are reportedly associated with improved survival, but the apparent survival benefits may simply reflect patient selection and the variable natural history of this malignancy. Before embarking on our own protocol of experimental treatment for mesothelioma, we sought to identify important prognostic factors and document the survival of patients treated conservatively (with palliative intent only) in our region.

METHODS

We performed a retrospective review of all patients with a diagnosis of malignant mesothelioma seen at our center between 1987 and 1999. Since curative intent treatment had not been given, we assumed that measured survival would largely reflect the natural history of the malignancy.

RESULTS

There were 101 patients (80 males and 21 females). Mean age was 65 +/- 9.2 years. Symptoms of disease were present for a median time of 5 months before the diagnosis was established. The most common presenting symptoms were dyspnea (46 patients), chest pain (30 patients), and weight loss (22 patients). Sixty-eight patients (68%) had a history of asbestos exposure. Mesothelioma subtypes included epithelial (43 patients), sarcomatous (26 patients), mixed (19 patients), desmoplastic (4 patients), and unspecified (9 patients). All 101 patients were treated with palliative intent. Talc pleurodesis was performed in 70 patients. At the time of analysis, 90 patients had died and 11 remained alive. Median survival was 213 (95% CI 137-289) days. Survival for the three major histological subtypes was significantly different (log rank, P = 0.0016). Histological subtype (epithelial favorable) was the only significant independent prognostic factor (Cox proportional hazard regression, P = 0.0009).

CONCLUSIONS

Patients with epithelial mesothelioma survive longer than those with other histological subtypes. Conservatively managed patients with pleural malignant mesothelioma have a median survival of approximately 7 months. These data from conservatively treated patients can serve as baseline information for future studies of experimental treatments.

A meta-analysis of randomized controlled trials of route of reconstruction after esophagectomy for cancer

BACKGROUND

A gastric conduit is usually used to reconstruct the foregut after esophagectomy for cancer. It can be transposed through a posterior or anterior mediastinal route. The choice of route is often debated but there is little evidence to support the use of one route over the other. We performed a meta-analysis of randomized controlled trials (RCTs) to determine the effect of route of reconstruction on patient outcomes.

METHODS

Medline and manual searches were done (completed independently and in duplicate) to identify all published RCTs that addressed the issue of route of gastric conduit reconstruction after esophagectomy for cancer. The selection process was inclusive; no trials were excluded. Trial validity assessment was done and a trial quality score was assigned. Major outcomes for quantitative data synthesis included operative mortality, anastomotic leaks, cardiac morbidity, and pulmonary morbidity. A random-effects model was used and relative risk was the principal measure of effect. Systematic qualitative review was used for other outcomes such as duration of ventilation, length of hospital stay, operative blood loss, duration of surgery, anastomotic strictures, dysphagia, gastric emptying, and quality of life. Data on cancer survival were not available in the RCTs.

RESULTS

Six RCTs were selected with quality scores ranging from 1 to 4 (5-point Jadad scale). Selection and validity agreement was strong. Relative risk (95% confidence interval; P value), expressed as posterior versus anterior mediastinal route (treatment versus control), was 0.56 (0.17, 1.82; P = 0.34) for mortality, 1.01 (0.35, 2.94; P = 0.98) for leaks, 0.43 (0.17, 1.12; P = 0.08) for cardiac complications, and 0.67 (0.34, 1.33; P = 0.26) for pulmonary complications. Systematic qualitative review did not suggest any difference in other perioperative outcomes or conduit function for the two routes of reconstruction.

CONCLUSIONS

Data synthesized from existing RCTs show that posterior and anterior mediastinal routes of reconstruction are associated with similar outcomes after esophagectomy for cancer. However, a difference in outcomes for the two reconstructive routes remains possible. Further trials with larger numbers of patients are needed.

High-affinity interactions of ligands at recombinant guinea pig 5HT7 receptors

The serotonin 5HT7 receptor has been implicated in numerous physiological and pathological processes from circadian rhythms to depression and schizophrenia. Clonal cell lines heterologously expressing recombinant receptors offer good models for understanding drug-receptor interactions and development of quantitative structure-activity relationships (QSAR). Comparative Molecular Field Analysis (CoMFA) is an important modern QSAR procedure that relates the steric and electrostatic fields of a set of aligned compounds to affinity. Here, we utilized CoMFA to predict affinity for a number of high-affinity ligands at the recombinant guinea pig 5HT7 receptor. Using R-lisuride as the template, a final CoMFA model was derived using procedures similar to those of our recent papers. The final cross-validated model accounted for >85% of the variance in the compound affinity data, while the final non-cross validated model accounted for >99% of the variance. Model evaluation was done using cross-validation methods with groups of 5 ligands. Twenty cross-validation runs yielded an average predictive r2(q2) of 0.779 +/- 0.015 (range: 0.669-0.867). Furthermore, 3D-chemical database search queries derived from the model yielded hit lists of promising agents with high structural similarity to the template. Together, these results suggest a possible basis for high-affinity drug action at 5HT7 receptors.

Mouse model for thoracic congenital scoliosis

SUMMARY

This study sought to produce a dose-response curve for acute and chronic maternal carbon monoxide (CO) exposure versus vertebral anomalies in mouse offspring and to determine the critical day of exposure. In Part I, pregnant CD-1 mice were exposed to an acute dose of CO at 9 days of gestation. A positive dose-response relationship of acute maternal CO exposure and vertebral anomalies in the offspring was produced. In Part II, pregnant females were exposed to chronic CO for the first 11 days of gestation. Chronic exposure to CO did not produce significant vertebral anomalies. In Part III, pregnant females were exposed to an acute dose of 600 ppm of CO at gestation day 8, 9, or 10. Day 9 in this mouse breed is the critical day for maternal exposure to CO. The detected anomalies were predominately in the thoracic spine.

Self-inflicted pneumothoraces

Self-inflicted pneumothoraces are rare manifestations of psychiatric illness. Two patients with self-inflicted pneumothoraces are reported, and the typical clinical features of factitious disorders are described. If thoracic surgeons are aware of these conditions, inappropriate surgery- and poor outcomes-can be avoided.

Factors that affect the occurrence of fumonisin

The two important Fusarium ear rots of corn, Gibberella ear rot (Fusarium graminearum, formally F. moniliforme and allied species) and Fusarium ear rot (F. verticillioides and allied species) grow under different environmental conditions. F. graminearum grows well only between 26 and 28 degrees C and requires rain both at silking and during disease progression. F. verticillioides grows well at higher temperatures, and ear rot and fumonisin accumulation are associated with drought and insect stress and growing hybrids outside their areas of adaptation. In southern Transkei, where esophageal cancer has been associated with the consumption of F. verticillioides and fumonisin-contaminated corn, environmental conditions favor this fungus in most years. In the nearby areas where the soils, crops, food consumption, and populations are the same and where esophageal cancer is low, temperatures are cooler and F. graminearum is favored. Although F. verticillioides is associated with a disease of corn, it may be that this fungus is a mutualistic endophyte of the plant. Perhaps because of this, breeding for resistance to Fusarium ear rot has produced inconclusive results to date. The best available strategies for reducing the risk of fumonisin contents of maize are to ensure that hybrids are adapted to the environment and to limit drought stress and insect herbivory. It may also be necessary to make use of alternative strategies such as producing hybrids that contain enzymes to degrade fumonisin as it is produced.

Core-binding factor beta (CBFbeta), but not CBFbeta-smooth muscle myosin heavy chain, rescues definitive hematopoiesis in CBFbeta-deficient embryonic stem cells

Core-binding factor beta (CBFbeta) is the non-DNA-binding subunit of the heterodimeric CBFs. Genes encoding CBFbeta (CBFB), and one of the DNA-binding CBFalpha subunits, Runx1 (also known as CBFalpha2, AML1, and PEBP2alphaB), are required for normal hematopoiesis and are also frequent targets of chromosomal translocations in acute leukemias in humans. Homozygous disruption of either the Runx1 or Cbfb gene in mice results in embryonic lethality at midgestation due to hemorrhaging in the central nervous system, and severely impairs fetal liver hematopoiesis. Results of this study show that Cbfb-deficient mouse embryonic stem (ES) cells can differentiate into primitive erythroid colonies in vitro, but are impaired in their ability to produce definitive erythroid and myeloid colonies, mimicking the in vivo defect. Definitive hematopoiesis is restored by ectopic expression of full-length Cbfb transgenes, as well as by a transgene encoding only the heterodimerization domain of CBFbeta. In contrast, the CBFbeta-smooth muscle myosin heavy chain (SMMHC) fusion protein generated by the inv(16) associated with acute myeloid leukemias (M4Eo) cannot rescue definitive hematopoiesis by Cbfb-deficient ES cells. Sequences responsible for the inability of CBFbeta-SMMHC to rescue definitive hematopoiesis reside in the SMMHC portion of the fusion protein. Results also show that the CBFbeta-SMMHC fusion protein transdominantly inhibits definitive hematopoiesis, but not to the same extent as homozygous loss of Runx1 or Cbfb. CBFbeta-SMMHC preferentially inhibits the differentiation of myeloid lineage cells, while increasing the number of blastlike cells in culture.

Personality disorders as extreme variants of common personality dimensions: can the Five-Factor Model adequately represent psychopathy?

The present study examined Widiger and Lynam's (1998) hypothesis that psychopathy can be represented using the Five-Factor Model (FFM) of personality. Participants in the study consisted of 481 21-22-year-old men and women who are part of an ongoing longitudinal study. Psychopathy was assessed by the degree of similarity between an individual's NEO-PI-R and an expert-generated FFM psychopathy prototype. The expert-based prototype supported the account of Widiger and Lynam (1998), as did the correlations between the NEO-PI-R Psychopathy Resemblance Index (PRI) and the individual personality dimensions. The PRI was also related in predicted ways to measures of antisocial behavior, drug use, and psychopathology. The results support the contention that psychopathy can be understood as an extreme variant of common dimensions of personality, and underscore the utility of a dimensional model of personality disorders.

Anastomotic leaks after esophagectomy for esophageal cancer: a comparison of thoracic and cervical anastomoses

BACKGROUND AND OBJECTIVES

Esophagogastric anastomotic leaks remain a significant problem after esophagectomy for esophageal cancer. Many investigators have reported that leaks are more frequent after cervical, as opposed to thoracic, esophagogastric anastomoses. We conducted a retrospective review to assess the effect of anastomotic location (thoracic or cervical) on anastomotic leak incidence and severity.

METHODS

Seventy-four consecutive patients with esophageal cancer underwent esophagectomy and esophagogastric anastomoses at our institution over a four-year period. Their charts were reviewed retrospectively and data was collected on age, gender, histology, stage, resection margin status, adjuvant therapy, cancer survival, anastomotic location, anastomotic leaks, and operative mortality.

RESULTS

Cervical anastomoses were done in 19 patients and thoracic anastomoses were done in the other 55 patients. The two groups were similar with respect to age, gender, histology, stage, adjuvant therapy, and overall survival. Operative mortality for the entire group of 74 patients was 4% (3 patients). Resection margins were positive for residual tumor in 2 of 19 (11%) patients with cervical anastomoses and 9 of 55 (16%) patients with thoracic anastomoses (p=0.42). Leaks complicated 1 of 19 (5%) cervical and 9 of 55 (16%) thoracic esophagogastric anastomoses (p=0.21). Positive resection margins and anastomotic leaks were not significantly related (p=0.54). One of 9 (11%) leaks in the thoracic group proved fatal.

CONCLUSIONS

In our experience cervical esophagogastric anastomoses do not have a higher incidence of leaks than thoracic anastomoses.

Open lung biopsy as an outpatient procedure

BACKGROUND

Lung biopsies are frequently needed to diagnose diffuse interstitial lung diseases. Both limited thoracotomy (open lung biopsy) and thoracoscopy can be used for lung biopsies, but both procedures have traditionally required hospital admission. We report a series of patients that underwent outpatient open lung biopsy to show the safety and effectiveness of this practice.

METHODS

We reviewed records of ambulatory, nonoxygen dependent patients with a clinical diagnosis of diffuse interstitial lung disease that underwent outpatient open lung biopsy between January 1997 and December 1999. All procedures were done by a senior surgeon using single lumen endotracheal anesthesia, a small anterolateral thoracotomy without rib spreading, stapled wedge resection, and no chest tube. Patients were discharged the same day.

RESULTS

Thirty-two patients with a clinical diagnosis of diffuse interstitial lung disease underwent outpatient open lung biopsy. Mean age was 58 years (range, 21 to 74 years). Preoperative forced expiratory volume in 1 second was 74.3%+/-7.0% of predicted. A pathologic diagnosis was established in all patients: usual interstitial pneumonia, 26 patients; sarcoidosis, 2; metastatic carcinoma, 2; desquamative interstitial pneumonia, 1; and mixed dust pneumoconiosis, 1 patient. No patient required a chest tube, overnight observation, or hospital admission. No complications occurred.

CONCLUSIONS

Selected patients with a clinical diagnosis of diffuse interstitial lung disease can safely and effectively undergo diagnostic outpatient open lung biopsy. However, careful patient selection and attention to operative detail are essential.

Local recurrence after total or subtotal esophagectomy for esophageal cancer

Cancer recurrence is a common problem after esophagectomy for esophageal cancer. Local recurrence is especially problematic because it often negates the palliative benefit of esophagectomy. We conducted a retrospective review to assess the effect of extent of esophageal resection (subtotal or total esophagectomy) on local cancer recurrence. Seventy-four consecutive patients with esophageal cancer underwent esophagectomy at our institution over a four-year period. Their charts were reviewed retrospectively and data was collected on age, gender, histology, stage, tumor location, operation, resection margin status, anastomotic leaks, operative mortality, adjuvant therapy, cancer survival, and local recurrence. Total esophagectomy was done in 19 patients (transhiatal - 3; McKeown - 16) and subtotal esophagectomy was done in the other 55 patients (Lewis - 25; left thoracoabdominal - 30). The two groups were similar with respect to age, gender, histology, stage, anastomotic leaks, operative mortality, adjuvant therapy, and overall survival. Resection margins were positive for residual tumor in 2 out of 19 (11%) total esophagectomies and 9 out of 55 (16%) subtotal esophagectomies (p=0.42). Local recurrence occurred in 3 of 19 (16%) patients treated with total esophagectomy and 23 out of 55 (42%) patients treated with subtotal esophagectomy (p=0.04). We conclude that total esophagectomy is associated with fewer local cancer recurrences than subtotal esophagectomy. We, therefore, recommend total esophagectomy for the surgical treatment of esophageal cancer.

Prophylactic intracavitary (pneumonectomy space) antibiotic instillation: a comparative study

BACKGROUND AND OBJECTIVES

Postpneumonectomy empyema is a dreaded complication of pneumonectomy. The effectiveness of prophylactic intracavitary antibiotic instillation is not known. We conducted a retrospective review to assess the effect of pneumonectomy space antibiotic instillation on septic complications (empyema and bronchial fistula) of pneumonectomy.

METHODS

Ninety-three consecutive patients underwent pneumonectomy at our institution over a three-year period. Their charts were reviewed retrospectively and data was collected on age, gender, diagnosis, intravenous antibiotics, intracavitary (pneumonectomy space) antibiotics, empyemas, bronchial fistulas, length of hospital stay, and operative mortality.

RESULTS

All 93 patients received 3 perioperative doses of prophylactic intravenous antibiotics. One group (n=47) of patients also received intraoperative intracavitary instillation of an antibiotic solution (penicillin G: 5 million units, bacitracin: 50,000 units, gentamicin: 60 mg, in 1 litre of saline) while the other group (n=46) did not. Age, gender, diagnosis, and length of stay were not significantly different in the two groups. There were no empyemas or bronchial fistulas in the intracavitary antibiotic group. Postpneumonectomy empyemas occurred in 6 (13%) patients (empyema with bronchial fistula: 5, empyema alone: 1) that had not received intracavitary antibiotics (p=0.012). There were 4 deaths (9%) in each group (p=0.63).

CONCLUSIONS

Prophylactic intraoperative intracavitary antibiotic instillation may reduce the incidence of empyemas after pneumonectomy. However, a randomized trial would be needed to prove the effectiveness of this form of prophylactic antibiotic strategy.

Temporal changes in soil properties at an upland Scottish site between 1956 and 1997

The aim of this study was to examine the frequency with which soil samples require to be taken in order to determine significant temporal changes in soil properties. The examination was carried out using data from Glensaugh Research Station in north-east Scotland where podzolic soils were sampled in 1956, 1977 and 1997, and by re-analysis of archived material. Significant differences in chemistry due to storage were detected, particularly decreases in pH of air-dried organic soils. In these cases original data were used for statistical analysis to establish changes between 1956 and 1997. Temporal changes were found for exchangeable Ca and Mg which generally decreased with time throughout the soil profile, whereas exchangeable H increased. Derived data, such as percent base saturation, declined dramatically due to decreases in exchangeable base cations. Similar podzolic soils were sampled at an adjacent Environmental Change Network (ECN) site in 1993. Application of statistical techniques to the ECN soil chemistry data allowed an estimation of the detectable change between any two years. These data along with the rates of temporal change from 1956 to 1997 allowed the calculation of the number of years required for measurable changes to be achieved. These changes and sampling intervals vary among different horizons and chemistries. Although they are site-specific, they do confirm that the current ECN protocols of a 5-year and 20-year sampling would be appropriate in order to detect changes in soil properties over time at this site.

Trends in stream water quality in Environmental Change Network upland catchments: the first 5 years

Hydrochemical data from catchment streams at three Environmental Change Network (ECN) upland catchments in north-east Scotland, south-east Scotland and northern England have been subjected to statistical analysis to separate the components due to long-term trend, season and flow. The relative variances due to each are presented for pH, Ca, SO4-S, NO3-N, DOC and Cl. Long-term trends have been identified with increases in concentration for NO3-N and DOC, decreases in SO4-S concentrations, along with short-term seasonal fluctuations. Application of this trend technique has allowed the detection of changes and contributed to an improved understanding of catchment behaviour.

Cost effectiveness of HMG-CoA reductase inhibition in Canada

OBJECTIVE

To assess the cost effectiveness of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor therapy, particularly atorvastatin, in primary and secondary prevention of coronary artery disease (CAD) in Canada.

METHODS

A Markov model was developed in which costs and effectiveness of atorvastatin were compared with those of other statins and with no drug therapy in primary and secondary prevention of CAD.

PATIENTS

Cost effectiveness was assessed for cohorts of patients with risk profiles defined by CAD status, age, sex, pretreatment low density lipoprotein cholesterol level and presence of sentinel coronary risk factors. Coronary risk was estimated by using initial and subsequent event coronary risk equations from the Framingham Heart Study, and risk factors were estimated by using Canadian population survey data. Recent estimates of the costs of CAD-related medical care in Canada were used to assign costs to health states and acute coronary events.

INTERVENTIONS

Interventions included atorvastatin 10 mg, simvastatin 10 mg, pravastatin 20 mg, fluvastatin 20 mg, lovastatin 20 mg and no pharmacological therapy.

RESULTS

Incremental cost effectiveness ratios (CDN$/year of life gained) relative to no therapy were lowest for atorvastatin and highest for pravastatin across all risk profiles. Atorvastatin was less costly and more effective than lovastatin, pravastatin and simvastatin in primary and secondary prevention, and conferred additional health benefits at a reduced cost per year of life gained compared with fluvastatin.

CONCLUSIONS

Atorvastatin was found to be the most cost effective statin in primary and secondary prevention of CAD.

Personality and sexual risk taking: a quantitative review

Findings from a quantitative review of the empirical research literature on normal personality and sexual risk taking are reported. The review focuses on domains identified in major models of normal personality representing the psychobiological and taxonomic perspectives. Focal sexual risk-taking behaviors were number of partners, unprotected sex, and high-risk sexual encounters (e.g., sex with a stranger). A comprehensive search produced 53 studies relevant to the review. A striking feature of the results is the paucity of research on domains of normal personality and sexual risk taking for all domains other than sensation seeking, which accounted for 64% of the effect sizes. The preponderance of studies (81%) took the psychobiological perspective and were published since 1990 (75%). Among the substantive findings were effects for sensation seeking, impulsivity, and agreeableness on all sexual risk-taking behaviors considered. Additionally, there were effects on specific behaviors for neuroticism and conscientiousness. The implications of these findings for future research on normal personality and sexual risk taking are discussed.

Comparison of videothoracoscopy and axillary thoracotomy for the treatment of spontaneous pneumothorax

Surgical treatment of spontaneous pneumothorax can be done through a thoracotomy or a video-thoracoscopic approach. Although the videothoracoscopic technique is currently popular it is not obviously superior to a more traditional axillary thoracotomy approach. We compared our recent experience with both techniques to determine the optimal surgical treatment for spontaneous pneumothoraces. A retrospective review of 79 patients treated surgically (34 thoracotomy and 45 thoracoscopy) for spontaneous pneumothoraces was done. Patients were treated between 1991 and 1997. Patients older than 60 years of age and those with spontaneous pneumothoraces secondary to generalized pulmonary emphysema were excluded. There were no operative deaths. Recurrence rate [thoracotomy, two of 34; thoracoscopy, three of 45 (P < 0.89)], air leak exceeding 7 days [thoracotomy, three of 34; thoracoscopy, three of 45 (P < 0.73)], operating room times [thoracotomy, 54 +/- 26 minutes; thoracoscopy, 53 +/- 16 minutes (P < 0.59)], and postoperative length of stay [thoracotomy, 5.7 +/- 4.3 days; thoracoscopy, 4.7 +/- 4.4 days (P < 0.26)] were not significantly different for the two techniques. We conclude that axillary thoracotomy and videothoracoscopy are equally effective surgical treatments for spontaneous pneumothoraces. A large randomized trial would be needed to determine whether one approach is truly superior to the other.

A randomized, controlled trial comparing thoracoscopy and limited thoracotomy for lung biopsy in interstitial lung disease

BACKGROUND

Lung biopsies are frequently needed to diagnose diffuse interstitial lung diseases. A prospective randomized, controlled trial comparing limited thoracotomy (open lung biopsy) and thoracoscopy for lung biopsy was done.

METHODS

Ambulatory patients with a clinical diagnosis of diffuse interstitial lung disease were randomized to thoracoscopy or limited thoracotomy. Data on postoperative pain, narcotic requirements, operating room time, adequacy of biopsy, duration of chest tube drainage, length of hospital stay, spirometry, and complications were collected.

RESULTS

A total of 42 randomized patients underwent lung biopsy (thoracoscopy 20, thoracotomy 22). The two study groups were comparable with respect to age, gender, corticosteroid use, and preoperative spirometry. Visual analog scale pain scores were nearly identical in the two groups (p = 0.397). Total morphine dose was 50.8 +/- 27.3 mg in the thoracoscopy group and 52.5 +/- 25.6 mg in the thoracotomy group (p = 0.86). Spirometry (FEV1) values in the two groups were not significantly different on postoperative days 1, 2, 14, and 28 (p = 0.665). Duration of operation was similar in both groups (thoracoscopy 40 +/- 30 minutes, thoracotomy 37 +/- 15 minutes; p = 0.67). The thoracoscopy and thoracotomy groups had equivalent duration of chest tube drainage (thoracoscopy 38 +/- 28 hours, thoracotomy 31 +/- 26 hours; p = 0.47) and length of hospital stay (thoracoscopy 77 +/- 82 hours, thoracotomy 69 +/- 55 hours; p = 0.72). Definitive pathologic diagnoses were made in all patients.

CONCLUSIONS

There is no clinical or statistical difference in outcomes for thoracoscopic and thoracotomy approaches. Both thoracoscopy and thoracotomy are acceptable procedures for diagnostic lung biopsy in diffuse interstitial lung disease.

Acute brachial plexus neuritis: an uncommon cause of shoulder pain

Patients with acute brachial plexus neuritis are often misdiagnosed as having cervical radiculopathy. Acute brachial plexus neuritis is an uncommon disorder characterized by severe shoulder and upper arm pain followed by marked upper arm weakness. The temporal profile of pain preceding weakness is important in establishing a prompt diagnosis and differentiating acute brachial plexus neuritis from cervical radiculopathy. Magnetic resonance imaging of the shoulder and upper arm musculature may reveal denervation within days, allowing prompt diagnosis. Electromyography, conducted three to four weeks after the onset of symptoms, can localize the lesion and help confirm the diagnosis. Treatment includes analgesics and physical therapy, with resolution of symptoms usually occurring in three to four months. Patients with cervical radiculopathy present with simultaneous pain and neurologic deficits that fit a nerve root pattern. This differentiation is important to avoid unnecessary surgery for cervical spondylotic changes in a patient with a plexitis.

Changes in rainfall chemistry and airborne particulates during a period of major local industrial change

Data from a site in central Scotland were used to quantify the changes in rainfall quality from 1989 to 1998. During this period there have been major changes in industrial activities in the area, particularly the decline in local steel-making and steel-processing activities. Many element concentrations in rainfall decreased over time in parallel with the phased reduction in the activity of local pollutant sources. Trend analyses of the rainfall data identified that the most significant responses have been the lower concentrations of Ca, SO4-S and Mn. There was also a dramatic decline in the capture of airborne particulates by the interception rainfall gauges. Particulates were found to contain mainly hematite, magnetite and quartz, that is similar to what would be expected to be derived from the neighbouring steel industries. The eventual disappearance of these particulates and the responses in rainfall quality match the timescale for the decline and closure of some of the potential sources of pollutants.

Lung volume reduction surgery: results of a Canadian pilot study. Canadian Lung Volume Reduction Surgery Study Group

OBJECTIVE

To present preliminary experience with lung volume reduction surgery (LVRS) before the institution of the Canadian LVRS trial.

DESIGN

A prospective case series between December 1995 and January 1997.

SETTING

University hospitals in London and Hamilton, Ont.

PATIENTS

Forty-nine patients who had disabling dyspnea or emphysema with hyperinflation, able to participate in respiratory rehabilitation. Twenty-three patients were excluded because of comorbid conditions precluding surgery, pulmonary hypertension, excessive steroid dependence, malnutrition, obesity, previous thoracotomy, large solitary bullae, concurrent malignant disease, chronic bronchitis, hypercapnia or psychiatric illness.

INTERVENTIONS

Preoperative respiratory rehabilitation followed by LVRS via median sternotomy.

MAIN OUTCOME MEASURES

Impairment, disability and handicap were assessed before and 12 months after LVRS. Impairment was assessed by changes in pulmonary function test results and blood gas measurements, disability by the 6-minute walk test and cardiopulmonary exercise test, and handicap by the disease-specific chronic respiratory disease questionnaire (CRQ), the generic medical outcomes survey short form 36 (SF-36) and the generic health utilities index mark III (HUI-III).

RESULTS

Two patients died of respiratory failure while in rehabilitation. Twenty-four patients (17 men, 7 women) successfully completed rehabilitation and underwent LVRS. The mean age was 63 years (range from 49 to 78 years) and the median length of hospital stay was 12.5 days (range from 7 to 90 days). Two patients (8%) died in the early postoperative period (within 30 days) of pneumonia. One patient died of respiratory failure 8 months after LVRS after a difficult 90-day postoperative hospital stay. There were 27 major complications. There was a 36% relative increase in the mean forced expiratory volume in the first second (p = 0.01) and a 10% relative increase in the 6-minute walk test (p = 0.06). The mean CRQ dyspnea score increased 2.3 points (p = 0.01), and the SF-36 general health domain increased 20 points (p = 0.01). There was no significant change in the HUI-III (p = 0.73).

CONCLUSION

LVRS appears to lessen the respiratory impairment and handicap for at least 1 year in selected patients with advanced emphysema.