Phase I clinical trial of the chimeric monoclonal antibody (c30.6) in patients with metastatic colorectal cancer

The murine antibody 30.6 recognizes an antigen that is expressed on a high proportion of colorectal carcinomas and their metastases. We report the results of single-dose escalation studies of the chimeric 30.6 (c30.6) monoclonal antibody in metastatic colorectal cancer, to evaluate its safety, pharmacokinetics, and biodistribution. Recombinant c30.6 (IgG1kappa) antibody was secreted from Chinese hamster ovary cells and purified by a multistep chromatography process. Seventeen patients with metastatic colorectal cancer were enrolled in this dose escalation study. The first four patients were treated with 3 mg of 123I-labeled c30.6, whereas the next 13 received a single dose of unlabeled antibody (maximum dose, 50 mg/m2). The most frequent side effect was a novel syndrome of severe burning and erythema of the face, chest, neck, ears, palms, soles, and genitalia. The frequency of this syndrome was markedly reduced in those patients premedicated with high doses of histamine receptor 1 and histamine receptor 2 blockers. Other side effects were mild and predictable. Biodistribution studies showed a rapid and intensive hepatic uptake. At the 50 mg/m2 level the half-life and maximum serum concentration were 81 +/- 15 h and 7.9 microg/ml, respectively. One patient developed a low-level human anti-c30.6 response. Tumor response was assessed by computed tomography, positron emission tomography scanning, and serial carcinoembryonic antigen measurements. There were no partial responses, although positron emission tomography scanning demonstrated some reduction in tumor activity in three individuals. The chimerized c30.6 antibody is not immunogenic in humans and appears worthy of further study. It does, however, produce a unique profile of side effects that can be well controlled with premedication.

Operative management and outcome of 302 abdominal vascular injuries

BACKGROUND

Abdominal vascular injuries incur high mortality rates. The purposes of this study are (1) review institutional experience, (2) determine additive effect on mortality of multiple vessel injuries, (3) determine mortality of combined arterial and venous injuries, and (4) correlate mortality with American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) for abdominal vascular injury.

METHODS

A retrospective 6-year study was made at an urban level I trauma center of patients with abdominal vascular injuries. Main outcome measure was survival.

RESULTS

(1) There was a total of 302 patients, mean age 28, mean Injury Severity Score (ISS) 25 (range 4 to 75). Mechanism of injury was penetrating in 266 (88%), blunt in 36 (12%). Emergency Department thoracotomy was done in 43 of 302 (14%), 504 vessels were injured: arteries 238(47%), veins 266(53%). Surgical management was ligation 245, primary repair 141, prosthetic interposition grafts 24, autogenous 2. Overall mortality was 162 of 302 (54%). (2) Mortality multiple vessels injured: 1 vessel 160 (45%), 2 vessels 102 (60%), 3 vessels 33 (73%), >4 vessels 5 (100%). Mortality arterial injuries: aorta isolated (I) 78% versus combined with other arterial injuries (C) 82.4%, superior mesenteric artery (SMA) I 47.6% versus C 71.4%, iliac I 53% versus C 72.7%, renal I 37.5% versus C 66.7%. Venous injuries: inferior vena cava (IVC) isolated (I) 70% versus combined with other venous injuries (C) 77.7%, superior mesenteric vein (SMV) I 52.7% versus C 65%, IMV I 16% versus C 50%. (3) Specific mortality combined arterial and venous injuries: aorta plus IVC 93%, SMA plus SMV 43%, iliac artery plus vein 45.5%. (4) Mortality versus AAST-OIS: grade II 25%, grade III 32%, grade IV 65%, grade V 88%.

CONCLUSION

Abdominal vascular injuries are highly lethal. Multiple arterial and venous injuries increase mortality. Mortality correlates with AAST-OIS for abdominal vascular injury.

Tuberculosis treatment failure and drug resistance--same strain or reinfection?

Tuberculosis patients may have Mycobacterium tuberculosis in their sputum at the end of treatment, and may show new drug resistance, due to either inadequate treatment of the original episode or reinfection with a new strain during therapy. In a cohort study of mineworkers with tuberculosis in South Africa, 57 of 438 patients had positive sputum cultures 6 months after recruitment in 1995. Of the 31 patients who initially had fully sensitive strains, 3 developed multidrug resistance (MDR) and 3 single-drug resistance (SDR). Of the 6 who started with SDR, 3 became MDR. HIV infection was not associated with drug resistance at enrollment or 6 months later. We compared pairs of DNA fingerprints from isolates of M. tuberculosis at recruitment and 6 months later in the 48 patients for whom we had both available. In 45, the pairs were identical. In 1 patient, although both isolates were fully sensitive, the later fingerprint had 1 less band (transposition). In 2 pairs, the fingerprint patterns were completely different: one seemed to be the result of laboratory error and the other was a true reinfection with an MDR strain. Despite a high risk of infection, with a moderate proportion of background drug-resistant strains (11% SDR, 6% MDR), reinfection is not a common cause of treatment failure or drug resistance at 6 months.

Helical computed tomographic scan in the evaluation of mediastinal gunshot wounds

BACKGROUND

The standard evaluation of mediastinal gunshot wounds usually requires angiography and either esophagoscopy or esophagography. In the present study, we have evaluated the role of helical computed tomographic (CT) scanning in reducing the need for angiographic and esophageal studies.

METHODS

This was a prospective study of patients with mediastinal gunshot wounds who were hemodynamically stable and would otherwise require angiography and esophageal evaluation. All patients underwent CT scan of the chest with intravenous contrast to delineate the missile trajectory. If the missile tract was in close proximity to the aorta, great vessels, or esophagus, then traditional evaluation with angiographic or esophageal evaluation was pursued.

RESULTS

A total of 24 patients met the inclusion criteria and underwent CT scan evaluation of their mediastinal gunshot wounds. One patient was taken for sternotomy to remove a missile embedded in the myocardium solely on the basis of the result of the CT scan. Because of proximity of the bullet tract, 12 patients required additional evaluation with eight angiograms and nine esophageal studies. One of these patients had a positive angiogram (bullet resting against the ascending aorta) and underwent sternotomy for missile removal; all other studies were negative. The remaining 11 patients were found to have well-defined missile tracts that approached neither the aorta nor the esophagus, and no additional evaluation was pursued. There were no missed mediastinal injuries in this group. Overall, 12 of 24 patients (50%) had a change in management (either received an operation or avoided additional radiographic or endoscopic evaluation) on the basis of the CT scan.

CONCLUSION

The helical CT scan provides a rapid, readily available, noninvasive means to evaluate missile trajectories. This permits accurate assessment of potential mediastinal injury and reduces the need for routine angiographic and esophageal studies.

Audit of cancer pain management in a cancer centre

Despite the availability of effective methods of controlling pain, many patients continue to receive inadequate pain relief. An audit was carried out on a single day to identify the prevalence, severity and management of cancer pain in adults in the two teaching hospitals in the Nottingham Cancer Centre. Of 186 patients with cancer, 52 had experienced pain as a result of their cancer during their admission. Of these 52 patients, 47 were assessed. More than half had unrelieved pain that was 'severe' at it s worst and interfered greatly with activities. Compared with patients whose pain had been relieved, patients with uncontrolled pain were likely to have spent less time in hospital, to have not had a formal assessment or reassessment of their pain and not to have a pain-care plan in the nursing notes or to have been seen by the hospital specialist palliative care team. We use our results to highlight areas of good practice, to identify where improvements could be made, and to inform the development of local standards and future audits.

Tuberculosis control and molecular epidemiology in a South African gold-mining community

BACKGROUND

Gold miners have very high rates of tuberculosis. The contribution of infections imported into mining communities versus transmission within them is not known and has implications for control strategies.

METHODS

We did a prospective, population-based molecular and conventional epidemiological study of pulmonary tuberculosis in a group of goldminers. Clusters were defined as groups of patients with Mycobacterium tuberculosis isolates with identical IS6110 DNA fingerprints. We compared the frequency of possible risk factors in the clustered and non-clustered patients whose isolates had fingerprints with more than four bands, and re-interviewed members of 45 clusters.

FINDINGS

Of 448 patients, ten were excluded because they had false-positive cultures. Fingerprints were made in 419 of 438, of which 371 had more than four bands. 248 of 371 were categorised into 62 clusters. At least 50% of tuberculosis cases were due to transmission within the community. Patients who had failed treatment at entry to the study were more likely to be in clusters (adjusted odds ratio 3.41 [95% CI 1.25-9.27]). Patients with multidrug-resistant isolates were more likely to have failed treatment but were less likely to be clustered than those with a sensitive strain (0.27 [0.09-0.83]). HIV infection was common (177 of 370 tested) but not associated with clustering.

INTERPRETATION

Despite a control programme that cures 86% of new cases, most tuberculosis in this mining community is due to ongoing transmission. Persistently infectious individuals who have previously failed treatment may be responsible for one third of tuberculosis cases. WHO targets for cure rates are not sufficient to interrupt transmission of tuberculosis in this setting. Indicators that are more closely linked to the rate of ongoing transmission are needed.

Evaluation of the porcine intestinal collagen layer as a biomaterial

The submucosal layer of the small intestine has been investigated as a source of collagenous tissue with the potential to be used as a biomaterial because of its inherent strength and biocompatibility. In this study we utilized a novel method for processing the tissue to generate an acellular intestinal collagen layer (ICL). This nondetergent, nonenzymatic chemical cleaning protocol removes cells and cellular debris without damaging the native collagen structure. Multilayer laminates of ICL crosslinked with a water-soluble carbodiimide (EDC) were evaluated as a tissue repair material in a rabbit abdominal hernia model. The ICL laminates provided the requisite physical properties and did not lead to adhesion formation. No immune response to the porcine collagen was detectable, and this material did not show any calcification in either the rabbit model or in the juvenile rat model.

Induction of the urokinase plasminogen activator system by oncostatin M promotes endothelial migration

Oncostatin M (OSM) is an inflammatory cytokine produced by activated macrophages and T-lymphocytes. We have previously demonstrated that OSM-induced endothelial cell migration, unlike endothelial cell proliferation and spindle formation, is independent of basic fibroblast growth factor expression (Wijelath et al. [1997] J. Cell. Sci. 110:871-879). To better understand the mechanism of OSM-induced endothelial cell migration, this study examined the potential role of the plasminogen activator system in promoting OSM mediated endothelial cell migration. OSM stimulated increased mRNA levels of urokinase-plasminogen activator (uPA) and urokinase-plasminogen activator receptor (uPAR) in a time and dose-dependent manner. Transcriptional run-off and mRNA stability analysis demonstrated that the increase in uPA and uPAR mRNA levels was due to both increased gene transcription and mRNA stability. The increase in mRNA correlated with increased protein levels of both uPA and uPAR. This increase was reflected in elevated levels of membrane-bound plasmin activity. OSM-induced endothelial cell migration was only partially dependent on plasmin activity since incubating endothelial cells without plasminogen or, in the presence of aprotinin, resulted in suppression of endothelial cell migration, indicating that OSM promoted endothelial cell migration through both a plasmin-dependent and -independent mechanism. Our results imply a role for OSM in promoting endothelial cell migration via a plasmin-dependent pathway and a uPAR-mediated pathway. Together, these and other recent studies support a role for OSM in modulating the different phases of angiogenesis.

Factors associated with an increased case-fatality rate in HIV-infected and non-infected South African gold miners with pulmonary tuberculosis

SETTING

A gold mining company in the Free State Province, South Africa.

AIM AND DESIGN

A retrospective cohort study to investigate factors associated with an increased case-fatality rate (CFR) at 6 months in human immunodeficiency virus (HIV) positive and negative tuberculosis (TB) patients.

RESULTS

Between April 1993 and March 1997, there were 2236 men with culture-confirmed pulmonary TB in whom HIV status and treatment outcome were known. The overall CFR within the first 6 months of therapy was low (3.6%). After adjusting for confounding factors, HIV infection (OR 15.0, 95%CI 7.4-30.6), self-presentation compared to detection by the active radiological screening programme (OR 5.6, 95%CI 2.6-12.2) and presence of silicosis (OR 3.0, 95%CI 1.4-6.3) were significantly associated with an increased CFR. Opportunistic infections accounted for 56.2% (36/64) of deaths in HIV-positive men. Cryptococcal disease accounted for 75% (27/36) of deaths from opportunistic infections.

CONCLUSION

HIV infection and silicosis are both powerful risk factors for TB and are associated with an increased risk of death. Strategies aimed at reducing these two risk factors within the workforce could reduce TB incidence and mortality. In settings with functional DOTS programmes and sufficient resources, expanding the DOTS programme to include active case detection should be explored as a means of reducing TB prevalence and mortality.

A method for monitoring the health of US Navy submarine crewmembers during periods of isolation

BACKGROUND

With the expansion of the manned space program, an essential consideration in planning is the medical support necessary for long-term missions. Information on analogous populations serving in isolated and/or contained environments may be useful in predicting health risks for astronauts.

METHODS

The present study evaluates rates of health events that occur in a highly screened, healthy military population during periods of isolation. A centralized database was designed to collect medical encounter data from U.S. Navy submarines and contains demographic information, crew rosters for each patrol, medical encounter notes, accident reports, medical evacuation reports, vital signs and laboratory data. The population included in the present analysis is composed of crewmembers aboard 136 submarine patrols between January 1, 1997 and December 31, 1998.

RESULTS

A total of 2,044 initial visits to medical staff and 973 re-visits for the same condition were recorded during these patrols. Potentially mission-impacting medical events reported among crewmembers were rare (i.e., among a crew of 10 individuals, only 1-2 medical events would be expected to occur during a 100 d-mission). The most common category of medical events was injury, followed by respiratory illnesses (URIs), skin problems (minor infections, ingrown toenail), symptoms and ill-defined conditions, digestive disorders, infectious conditions, sensory organ problems (ear and eye), and musculoskeletal conditions.

Phase I trial of the anti-Lewis Y drug immunoconjugate BR96-doxorubicin in patients with lewis Y-expressing epithelial tumors

PURPOSE

We conducted a phase I clinical trial of BR96-Doxorubicin (BR96-Dox), a chimeric anti-Lewis Y (Le(Y)) monoclonal antibody conjugated to doxorubicin, in patients whose tumors expressed the Le(Y) antigen. The study aimed to determine the toxicity, maximum-tolerated dose, pharmacokinetics, and immunogenicity of BR96-Dox.

PATIENTS AND METHODS

This was a phase I dose escalation study. BR96-Dox was initially administered alone as a 2-hour infusion every 3 weeks. The occurrence of gastrointestinal (GI) toxicity necessitated the administration of BR96-Dox as a continuous infusion over 24 hours and use of antiemetics and antigastritis premedication. Patients experiencing severe GI toxicity underwent GI endoscopy. All patients underwent restaging after two cycles.

RESULTS

A total of 66 patients predominantly with metastatic colon and breast cancer were enrolled onto the study. The most common side effects were GI toxicity, fever, and elevation of pancreatic lipase. At higher doses, BR96-Dox was associated with nausea, vomiting, and endoscopically documented exudative gastritis of the upper GI tract, which was dose-limiting at a maximum dose of 875 mg/m(2) (doxorubicin equivalent, 25 mg/m(2)) administered every 3 weeks. Toxicity was reversible and generally of short duration. Premedication with the antiemetic Kytril (granisetron hydrochloride; SmithKline Beecham, Philadelphia, PA), the antacid omeprazole, and dexamethasone was most effective in ameliorating GI toxicity. A dose of 700 mg/m(2) BR96-Dox (doxorubicin equivalent, 19 mg/m(2)) every 3 weeks was determined to be the optimal phase II dose when administered with antiemetic and antigastritis prophylaxis. BR96-Dox deposition on tumor tissue was documented immunohistochemically and by confocal microscopy. At the 550-mg/m(2) dose, the half-life (mean +/- SD) of BR96 and doxorubicin was 300 +/- 95 hours and 43 +/- 4 hours, respectively. BR96-Dox elicited a weak immune response in 37% of patients. Objective clinical responses were seen in two patients.

CONCLUSION

BR96-Dox provides a unique strategy to deliver doxorubicin to Le(Y)-expressing tumor and was well tolerated at doses of 700 mg/m(2) every 3 weeks. BR96-Dox was not associated with the typical side-effect profile of native doxorubicin and can potentially deliver high doses of doxorubicin to antigen-expressing tumors. A phase II study in doxorubicin-sensitive tumors is warranted.

Correlation between autopsy findings for chronic obstructive airways disease and in-life disability in South African gold miners

OBJECTIVES

In South Africa chronic obstructive airway disease (COAD), which could be due to working in a dusty atmosphere in scheduled mines or works, is a compensatable disease. Miners are compensated for in-life respiratory disability and for findings at autopsy of COAD, which includes emphysema, bronchitis assessed by mucus gland hyperplasia in the main bronchus, and bronchiolitis assessed by goblet cell metaplasia. The question arises as to whether the autopsy findings correlate with in-life impairment. The objectives of the study were: (1) to determine whether autopsy COAD outcomes relate to lung function and to respiratory symptoms and signs; and (2) to quantify the individual contributions of emphysema, bronchiolitis and bronchitis to lung function impairment.

METHODS

On 724 gold miners, pathological findings of COAD--emphysema, bronchitis and bronchiolitis-- were related to lung function measurements and respiratory symptoms and signs observed within 5 years prior to death.

RESULTS

Emphysema diagnosed at autopsy was the main determinant of airflow impairment. The emphysema score categories 0-5, 5-35, 35-65 and > 65 were associated with decreased forced expiratory volume in 1 s, expressed as percentage predicted (FEV1%) as follows: 78.8%, 66.2%, 52.0% and 46.0%, respectively. The score was also associated with increasing frequency of dyspnoea. After adjustment for emphysema, the bronchitis and bronchiolitis were not related to significant lung function loss, and in subjects without emphysema, the presence of moderate or marked bronchitis was associated with a mild impairment only. Bronchitis at autopsy was associated with increased frequency of rhonchi, sputum and cough, whereas bronchiolitis was associated with increased sputum only. Silicosis found at autopsy was associated with some obstructive and restrictive lung function impairment. Tobacco smoking was associated with all the COAD outcomes.

Nefazodone treatment for chronic posttraumatic stress disorder: an open trial

Currently, there is no standard treatment for posttraumatic stress disorder (PTSD) because of a deficit of systematic treatment trials. The symptom overlap with other mood and anxiety disorders that respond to antidepressants and the results of a limited number of antidepressant trials indicate promise for psychopharmacologic treatment. Several open trials and one controlled trial with selective serotonin reuptake inhibitors have reported improvement in the symptomatology of PTSD. In this study, a relatively new serotonergic antidepressant, nefazodone, was tested as a treatment for PTSD. Veterans with chronic PTSD (N = 36) were enrolled in an 8-week open-label trial of nefazodone. The primary outcome measure was the Clinician-Administered PTSD Scale (CAPS). Thirty-one patients completed at least 4 weeks of treatment, which was considered to be an adequate trial, and 26 patients completed the 8-week study. During treatment, there was a significant decrease in the total CAPS score and in each of three CAPS subscale scores, with most of the improvement occurring during the first 4 weeks. Comparable improvements were also seen on the Hamilton Rating Scales for Anxiety and for Depression. Nefazodone treatment was well tolerated by this patient population, with only four patients discontinuing because of adverse effects. In summary, nefazodone treatment improved the symptoms of PTSD, including the core symptoms. Placebo-controlled studies should be undertaken to further elucidate the efficacy of nefazodone in the treatment of PTSD.

Nonskeletal cervical spine injuries: epidemiology and diagnostic pitfalls

BACKGROUND

Cervical spine injuries are the most commonly missed severe injuries with serious implications for the patient and physician. The diagnosis of subluxations or spinal cord injuries in the absence of vertebral fractures, especially in unevaluable patients, poses a major challenge. The objective of this study was to study the incidence and type of cervical spine trauma according to mechanism of injury; identify problems and pitfalls in the diagnosis of nonskeletal cervical spine injuries.

METHODS

Retrospective study of all C-spine injuries caused by traffic accidents or falls admitted over a 5-year period at a large Level I trauma center. Data were obtained from the trauma registry, review of patient charts, and radiology reports.

RESULTS

During the study period, there were 14,755 admissions due to traffic injuries or falls who met trauma center criteria. There were 292 patients with C-spine injuries, for an overall incidence of 2.0% (3.4% in car occupants, 2.8% for pedestrians, 1.9% for motorcycle riders, and 0.9% for falls). The incidence of C-spine injuries in patients with a Glasgow Coma Scale score of 13 to 15 was 1.4%, 9 to 12 was 6.8%, and in < or =8 was 10.2% (p < 0.05). Of C-spine injuries, 85.6% (250 patients) were a vertebral fracture, 10.6% of the injuries (31 patients) were subluxation without fractures, and 3.8% (11 patients) were an isolated spinal cord injury without fracture or subluxation. Of the 31 patients with isolated subluxations, one-third required an early endotracheal intubation before clinical evaluation of the spine, because of associated severe head injury or hypotension. Adequate lateral C-spine films diagnosed or suspected 30 of the 31 subluxations (96.8%). The combination of plain films and computed tomographic (CT) scan diagnosed or suspected all injuries. Of the 11 patients with isolated cord injury, 27.3% required early intubation before clinical evaluation of the spine. The diagnosis of cord injury was made on admission in only five patients (45.5%). In three patients, the neurologic examination on admission was normal and neurologic deficits appeared a few hours later. In the remaining three patients (two intubated, one intoxicated), the diagnosis was missed clinically and radiologically.

CONCLUSIONS

Isolated nonskeletal C-spine injuries are rare but potentially catastrophic because of the high incidence of neurologic deficits and missed diagnosis. In subluxations, the combination of an adequate lateral film and CT scan was reliable in diagnosing or highly suspecting the injury. A large prospective study is needed to confirm these findings, before a recommendation is made to remove the cervical collar if the findings of these investigations are normal. However, in isolated cord injuries, the diagnosis was often missed because of associated severe head trauma and the low sensitivity of the plain films and CT scans.

Osteosarcoma in preadolescent patients

The medical records of boys younger than 11 years and girls younger than 10 years of age with osteosarcoma of the pelvis or extremity were reviewed. Thirty patients were identified who were newly diagnosed but untreated for osteosarcoma. None of these patients had pulmonary metastases. The same four protocols were used to treat the patients in the current study as were used to treat adolescents. The event-free and overall survival was calculated and prognostic factors were assessed. The median followup time was 8 years (range, 6-14 years). The results were compared with the results of older patients treated with the same protocols and with published results. Fourteen patients had pulmonary metastases (47%); among these patients, four also had skeletal metastases (in two of the latter, skeletal metastases appeared before the pulmonary metastases). Event-free survival was 53% and overall survival was 57%. This result is comparable with current survival results in adolescent and older patients. Serum alkaline phosphatase and serum lactic dehydrogenase levels before treatment, height percentile greater than 50%, chemotherapy-induced tumor necrosis, surgical procedure, tumor site, tumor histologic features, and patient gender were not prognostic indicators. The prognosis for prepubertal patients with osteosarcoma is similar to the prognosis of their adolescent and older counterparts. There does not seem to be any indication to treat preadolescent patients with osteosarcoma using alternate therapies.

In vitro activities of nontraditional antimicrobials against multiresistant Acinetobacter baumannii strains isolated in an intensive care unit outbreak

Fifteen multiresistant Acinetobacter baumannii isolates from patients in intensive care units and 14 nonoutbreak strains were tested to determine in vitro activities of nontraditional antimicrobials, including cefepime, meropenem, netilmicin, azithromycin, doxycycline, rifampin, sulbactam, and trovafloxacin. The latter five drugs were further tested against four of the strains for bactericidal or bacteriostatic activity by performing kill-curve studies at 0.5, 1, 2, and 4 times their MICs. In addition, novel combinations of drugs with sulbactam were examined for synergistic interactions by using a checkerboard configuration. MICs at which 90% of the isolates tested were inhibited for antimicrobials showing activity against the multiresistant A. baumannii strains were as follows (in parentheses): doxycycline (1 microg/ml), azithromycin (4 microg/ml), netilmicin (1 microg/ml), rifampin (8 microg/ml), polymyxin (0.8 U/ml), meropenem (4 microg/ml), trovafloxacin (4 microg/ml), and sulbactam (8 microg/ml). In the kill-curve studies, azithromycin and rifampin were rapidly bactericidal while sulbactam was more slowly bactericidal. Trovafloxacin and doxycycline were bacteriostatic. None of the antimicrobials tested were bactericidal against all strains tested. The synergy studies demonstrated that the combinations of sulbactam with azithromycin, rifampin, doxycycline, or trovafloxacin were generally additive or indifferent.

Drug-resistant pulmonary tuberculosis in a cohort of southern African goldminers with a high prevalence of HIV infection

OBJECTIVES

To determine rates of drug resistance to Mycobacterium tuberculosis and associated risk factors, including HIV infection.

DESIGN

Prospective cohort study of patients with pulmonary tuberculosis.

SETTING

The study population comprised 28,522 men working on four goldmines in Westonaria, Gauteng. Health care is provided at a 240-bed mine hospital, Gold Fields West Hospital, and its primary health care facilities.

SUBJECTS

All 425 patients with culture-positive pulmonary tuberculosis identified in 1995.

OUTCOME MEASURES

Tuberculosis drug resistance on enrollment and after 6 months' treatment.

RESULTS

There were 292 cases of new tuberculosis, 77 of recurrent disease and 56 prevalent cases in treatment failure. Two hundred and seven patients (48.7%) were HIV infected. Primary resistance to one or more drugs (9%) was similar to the 11% found in a previous study done on goldminers in 1989. Primary multidrug resistance (0.3%) was also similar (0.8%). Acquired multidrug resistance was 18.1%: 6.5% for recurrent disease and 33.9% in treatment failure cases. Neither HIV infection nor the degree of immunosuppression as assessed by CD4+ lymphocyte counts was associated with drug resistance at the start or end of treatment. New patterns of drug resistance were present in 9 of 52 patients in treatment failure at 6 months, 1 of whom was HIV-infected.

CONCLUSION

Primary and acquired drug resistance rates are stable in this population and are not affected by the high prevalence of HIV infection.

The relation between baseline HIV drug resistance and response to antiretroviral therapy: re-analysis of retrospective and prospective studies using a standardized data analysis plan

To assess the relation between resistance to antiretroviral drugs for treatment of HIV-1 infection and virological response to therapy, results from 12 different studies were re-analysed according to a standard data analysis plan. These studies included nine clinical trials and three observational cohorts. The primary end-point in our analyses was virological failure by week 24. Baseline factors that were investigated as predictors of virological failure were plasma HIV-1 RNA, the number and type of new antiretroviral drugs in the regimen, and viral susceptibility to the drugs in the regimen, determined by genotyping or phenotyping methods. These analyses confirmed the importance of both genotypic and phenotypic drug resistance as predictors of virological failure, whether these factors were analysed separately or adjusted for other baseline confounding factors. In most of the re-analysed studies, the odds of virological failure were reduced by about twofold for each additional drug in the regimen to which the patient's virus was sensitive by genotyping methods, and by about two- to threefold for each additional drug that was sensitive by phenotyping.

Sex differences in cardiac rehabilitation

OBJECTIVE

To determine and compare the baseline characteristics and outcomes between men and women in a Canadian cardiac rehabilitation program.

DESIGN

Nonrandomized, retrospective, observational study with a before and after research design.

SETTING

The Prevention and Rehabilitation Centre at the University of Ottawa Heart Institute, Ottawa, Ontario, a tertiary cardiac care centre.

PATIENTS

Three hundred and eighty-seven patients, 82% male aged 59+/-10 years and 18% female aged 61+/-4 years, who were enrolled in the on-site cardiac rehabilitation program between November 1, 1995 and April 1, 1997.

INTERVENTION

A three-month, multifactorial cardiac rehabilitation program that incorporates exercise training, risk factor modification, education and psychosocial support.

MAIN RESULTS

Fewer than 20% of all rehabilitation participants (n=70; 18%) were women; most participants were under 65 years of age. More women than men had a primary diagnosis of myocardial infarction (42% versus 28%, respectively), whereas men were more likely than women to have had coronary artery bypass grafting (45% versus 23%, respectively). Men and women had similar mean baseline measures of body mass index, blood pressure and glucose levels, whereas women had significantly higher mean baseline measures of total cholesterol (5.6 mmol/L versus 5.0 mmol/L for men, P 0.001), low density lipoprotein (LDL) cholesterol (3.4 mmol/L versus 3.1 mmol/L, P=0. 012) and high density lipoprotein (HDL) cholesterol (1.2 mmol/L versus 1.0 mmol/L, P 0.001). Baseline LDL to HDL ratios were 3.3 for men and 3.0 for women (not significant), and total cholesterol to HDL ratios were 5.4 and 4.9 for men and women, respectively. Men had a higher exercise capacity than women coming into the program (metabolic equivalent [METs] 6.6 versus 4.9, respectively, P 0.001), had a higher baseline activity level (1114 kcal/week versus 617 kcal/week, P=0.001) and scored higher than women in all health-related quality of life scores. After the program, there were no significant sex differences in improvement in MET level, physical activity or risk factor profile. Although men exercised more than women (increase of 557 kcal/week versus 343 kcal/week, respectively), this was not statistically significant. In health-related quality of life scores, both men and women improved in all scores, although women reported less increase than men in their level of overall vitality (P=0.016).

CONCLUSION

Women are the minority of cardiac rehabilitation patients, although they appear to benefit equally well from the program.

Psychologic distress among spouses of patients undergoing cardiac rehabilitation

OBJECTIVE

The goal of this study was to identify common sources of distress in spouses of patients undergoing cardiac rehabilitation and to compare spouses classified as being in distress and those classified as nondistressed on demographic variables, their experiences of stress, coping strategies employed, marital intimacy, and level of family functioning. The study aimed to describe the needs of spouses with respect to possible interventions.

DESIGN

A cross-sectional analysis was used.

SETTING

The study was located at the University of Ottawa Heart Institute Prevention and Rehabilitation Centre's cardiac rehabilitation program.

OUTCOME MEASURES

Scores on the Brief Symptom Inventory, Heart Disease Hassles Scale, Coping Strategies Inventory, Miller Intimacy Scale, and McMaster Family Assessment Device were used as outcome measures.

RESULTS

Two hundred thirteen female spouses of patients undergoing cardiac rehabilitation participated in this study. Sixty-six percent of the spouses met the criteria for distress. This was more common in younger spouses (51.99 +/- 9.94 years) than in older spouses (55. 74 +/- 10.54 years) (t = -2.45; P =.013). Distressed spouses used disengagement coping strategies significantly more than the nondistressed spouses (t = 6.91; P =.0001). Distressed spouses also reported significantly less intimacy in their marriages (t = -3.99; P =.0001) and poorer family functioning (t = 5.86; P =.0001). The most prevalent symptoms of psychologic distress included feeling tense, having trouble falling asleep and feeling easily hurt. The most prevalent stressors were as follows: (1) worries about treatment, recovery, and prognosis (75.5%); (2) moodiness of the patient (66.7%); (3) worries about the patient returning to work and about money (38.8%); (4) sexual concerns (36.7%); and (5) helplessness or apathy on the part of the patient and increased spousal responsibility (36.1%).

CONCLUSIONS

Spouses of patients undergoing cardiac rehabilitation should be screened for psychologic distress, and those in distress should be offered interventions focused on assisting them to deal with specific stressors related to their experience with a spouse with heart disease. Interventions indicated include stress-management techniques and encouraging the use of engagement coping strategies. In addition, marital and family concerns need to be directly addressed in support interventions.

Induction of human neutrophil apoptosis by nitric oxide donors: evidence for a caspase-dependent, cyclic-GMP-independent, mechanism

This study investigated the regulatory effects of the major inflammatory mediator, nitric oxide (NO), on human neutrophil apoptosis in vitro. Co-culture of human neutrophils with the NO donors GEA 3162 (1,2,3,4-oxatriazolium,5-amino-3-(3,4-dichlorophenyl)-chloride) (10-100 microM) and 3-morpholino-sydnonimine (SIN-1) (0.3-3 mM) caused a dramatic and concentration-dependent induction of apoptosis. However, N-formyl-methionyl-leucyl-phenylalanine (FMLP)-induced neutrophil activation (actin reorganization and chemotaxis) was inhibited by GEA 3162 treatment. The pro-apoptotic effects of the NO donors were (i) unaffected by the soluble guanylate cyclase inhibitor LY-83583 (6-anilino-5,8-quinolinedione; 100 microM), (ii) antagonized by superoxide dismutase (6 microg/mL), (iii) mimicked by exogenous peroxynitrite (at concentrations >100 microM), and (iv) inhibited by the caspase inhibitor Z-Val-Ala-DL-Asp-fluoromethylketone (100 microM). The pro-apoptotic effect of the NO donors was not mimicked by the cell-permeable cyclic nucleotide analogue, N6,2-O-dibutyrylguanosine-3',5'-cyclic monophosphate (dibutyryl-cGMP) at concentrations < or =0.2 mM. Indeed, at high concentrations (> or =2 mM), dibutyryl-cGMP caused an inhibition of apoptosis. These results suggest that NO-mediated apoptosis, although caspase-dependent, is mediated by a cGMP-independent mechanism and involves the concurrent generation of oxygen free radicals and, potentially, peroxynitrite. Our data reveal a unique role for NO in inflammatory responses with differential effects upon neutrophil activation and survival, with important implications for the successful resolution of inflammation.