Diesel exhaust particles override natural injury-limiting pathways in the lung

Induction of effective inflammation in the lung in response to environmental and microbial stimuli is dependent on cooperative signaling between leukocytes and lung tissue cells. We explored how these inflammatory networks are modulated by diesel exhaust particles (DEP) using cocultures of human monocytes with epithelial cells. Cocultures, or monoculture controls, were treated with DEP in the presence or absence of LPS or flagellin. Production of cytokines was explored by Western blotting and ELISA; cell signaling was analyzed by Western blotting. Here, we show that responses of epithelial cells to DEP are amplified by the presence of monocytes. DEP amplified the responses of cellular cocultures to very low doses of TLR agonists. In addition, in the presence of DEP, the responses induced by LPS or flagellin were less amenable to antagonism by the physiological IL-1 antagonist, IL-1ra. This was paralleled by the uncoupling of IL-1 production and release from monocytes, potentially attributable to an ability of DEP to sequester or degrade extracellular ATP. These data describe a model of inflammation where DEP amplifies responses to low concentrations of microbial agonists and alters the nature of the inflammatory milieu induced by TLR agonists.

Basic science of the innate immune system and the lung

Infections of the lung are prevented first by denial of access, mediated by humoral and cellular systems that obscure the pathogen's target, simultaneously acting to kill and clear the pathogen. Where pathogens penetrate these initial defence systems, rapid detection of their presence is achieved by their engagement with a large family of pattern recognition receptors, including Toll-like receptors, retinoic-acid-inducible gene-like helicases and Nod-like receptors. Activation of a coordinated inflammatory response is achieved by cooperative signalling between sentinel leucocytes such as alveolar macrophages and lung tissue, following which a profound pro-inflammatory response mobilizes phagocytes such as neutrophils and monocytes to the lung. Resolution of the innate immune response, largely dependent upon neutrophil apoptosis, results in restoration of normal tissue architecture. In chronic disease, dysregulated inflammation maintains these systems in a state of constant activation, potentially resulting in tissue damage and progressive disease.

Reducing the toll of inflammatory lung disease

Toll-like receptors (TLRs) are pivotal in human response to microbial stimuli. Their activation and signaling underpin much of the observed epidemiologic data generated by the hygiene hypothesis, and their contribution to infectious exacerbations of airways disease is likely to be highly important. Our growing knowledge in this field will have a significant impact on the understanding of the pathogenesis of inflammatory diseases, and TLR-based therapies are already in early clinical trials to modify atopic disease severity.

Effect of training on patient outcomes following lobectomy

BACKGROUND

Little is known about the effect of surgical training on outcomes in thoracic surgery. The impact of surgeon training on outcomes following lung resection was examined, focusing on lobectomy as a marker operation.

METHODS

328 consecutive patients who underwent lobectomy at our institution between 1 October 2001 and 30 June 2003 were studied. Data were collected prospectively during the patient's admission as part of routine clinical practice and validated by a designated audit officer. Patient characteristics and postoperative outcomes were compared between trainee led and consultant led operations.

RESULTS

In 115 cases (35.1%) the operation was performed by a trainee thoracic surgeon as the first operator. There were no significant differences in patient characteristics between the two groups. In-hospital mortality was similar for operations led by trainees and consultants (3.5% and 2.8%, respectively; p > 0.99). Outcomes in the two groups did not differ significantly with respect to respiratory, cardiovascular, renal, neurological, chest infection, bleeding, and gastrointestinal complications. Survival rates at 1 year were 82.6% for procedures led by trainees compared with 81.7% for procedures led by consultants (p = 0.83).

CONCLUSIONS

With appropriate supervision, trainee thoracic surgeons can perform lobectomies safely without compromising short or intermediate term patient outcome.

Toll-like receptors and chronic lung disease

TLRs (Toll-like receptors) comprise a family of proteins whose function is principally to facilitate the detection of, and response to, pathogens. Protozoa, helminths, viruses, bacteria and fungi can all activate TLR signalling, and these signals have important roles in the activation of host defence. TLRs may also respond to products of tissue damage, providing them with roles in infective and sterile inflammation. Their role as detectors of pathogens and pathogen-associated molecules provides molecular mechanisms to underpin the observations leading to the hygiene hypothesis. Targeting of TLR signalling has implications in the control of infection, vaccine design, desensitization to allergens and down-regulation of inflammation. This review will explore TLR history, molecular signalling and the potential roles of TLRs in chronic lung disease.

Can pneumonectomy for non-small cell lung cancer be avoided? An audit of parenchymal sparing lung surgery

BACKGROUND

Lung cancer resection rates are suboptimal in the UK. Pneumonectomy has a higher perioperative mortality risk than lobectomy. To increase resection rates and improve outcomes we have implemented a policy of parenchymal sparing surgery for tumours involving a main stem bronchus.

METHODS

In a prospective 4 year study of 119 consecutive patients operated upon by a single surgeon the perioperative course, pathology and survival were compared for 81 patients undergoing pneumonectomy and 38 patients in whom pneumonectomy was avoided by bronchoplastic+/-angioplastic procedures.

RESULTS

The rate of pneumonectomy decreased significantly with increasing experience with parenchymal sparing surgery (R(2)=0.98, P<0.001) with 21 of the last 30 patients (70%) avoiding pneumonectomy. There were no significant inter-group differences in patient characteristics, perioperative course or outcome. One-year survival was 64% after pneumonectomy and 73% after sleeve lobectomy. However the perioperative loss of respiratory function was significantly lower in the patients in whom pneumonectomy was avoided (P=0.0003).

CONCLUSIONS

Pneumonectomy can be avoided in a large proportion of patients with non-small cell lung cancer of a main stem bronchus without adversely affecting outcome but with preservation of lung function

Emergency reinstitution of cardiopulmonary bypass following cardiac surgery: outcome justifies the cost

OBJECTIVE

Crash back on bypass (crash-BOB) is occasionally required in the resuscitation of patients developing life-threatening complications following cardiac surgery. This study aims to determine the incidence, aetiology and cost-effectiveness of such intervention.

METHODS

Retrospective review of all crash-BOB patients over 5.5 years at one hospital.

RESULTS

The incidence of crash-BOB was 0.8% and occurred at a mean of 7 h post-operatively (range 1 h-20 days). Pre-operative Parsonnet scores were similar to the overall population of patients undergoing surgery in our institution (mean score 10; range 0-45). The original cardiac operations were coronary revascularization (39), valve surgery (12) and others (4). Indications for crash-BOB were cardiac arrest (23), bleeding (20), hypotension (7), ischaemia (1) and others (4). Of the 55 patients, 20 died on the operating table. Of the remaining 35, a further 12 died in hospital. Overall survival was therefore 42%. Where crash-BOB was for bleeding, 17 of 20 patients (85%) survived to leave theatre, of whom 11 patients (55%) left hospital alive. In the 35 non-bleeders, only 18 (51%) survived crash-BOB and 12 (34%) left hospital alive. Sixteen patients required a second period of aortic cross-clamping of whom 13 (81%) survived to leave theatre, and 11 (69%) left hospital alive. Conversely, of nine patients in whom no specific diagnosis was found during crash-BOB, only two (22%) survived the procedure and none survived to hospital discharge. Multiple logistic regression identified pre-operative Parsonnet score (P=0.045) and the need for aortic cross-clamping to deal with an identified surgical problem (P=0.03) as significant predictors of hospital survival. Indication for crash-BOB (bleeder/non-bleeder) failed to reach significance (P=0.08). Age, sex, intra-aortic balloon pump use at the primary procedure, and time following the primary procedure to crash-BOB were not identified as predictors of hospital survival. Of the 23 hospital survivors, three patients suffered a stroke post-operatively and made a good functional recovery prior to discharge. Two patients developed sternal wound dehiscence requiring surgical rewiring. At follow-up (mean 3 years, range 1-6 years), 19 patients were in NYHA class I and four were in class II. Crash-BOB patients required an average of 8 extra intensive care days and 2 extra ward days. The total cost of these resources was pound164900 (including theatre time, cardiopulmonary bypass and intra-aortic balloon pump use). This was equivalent to pound7170 per life saved.

CONCLUSIONS

Crash-BOB occurred in 0.8% of cases and was associated with a survival to discharge of 42%, and a justifiable cost of only pound7170 per life saved. Establishing an accurate diagnosis for the cause of clinical deterioration resulting in crash-BOB intervention was important, and the need for a further period of aortic cross-clamping did not preclude a favourable outcome.

A simple method of treating coronary air embolism after cardiopulmonary bypass

Coronary air embolism is a potential complication of cardiac operations performed with cardiopulmonary bypass, especially open heart operations. There are many recommended methods described in the literature to treat the sequelae of coronary air embolism, none universally effective. We describe a simple and safe method to treat the condition, which we have found very effective in our practice.

Current practice in thoracic sympathectomy

Thoracic sympathectomy has been performed for many years. With the recent development of video assisted thoracic surgical techniques the indications for surgery have increased, and the outcome is much better.

Child health, poverty and the environment: the Canadian context

In Canada, there has been little research exploring the link between child poverty and exposure to environmental contaminants. However, children living in poverty are more likely to grow up in neighbourhoods adjacent to polluting industries and heavily used transportation corridors. They are also more likely to live in improperly designed or maintained buildings where levels of contaminants and toxic residuals may be high, and indoor air quality poor. Risk factors such as exposure to cigarette smoke and poor nutritional status, together with the above living conditions during growth and development, create conditions that make children living in poverty more vulnerable to the effects of environmental contaminants. In Toronto, the South Riverdale Community Health Centre is developing grassroots techniques to build awareness and protect citizens. Given the growing levels of child poverty in Canada and decreasing environmental protection, the author suggests increased community action and health research for use in advocating for appropriate policy changes.

Perinatal mortality in eclampsia in relation to drug therapy

Fifty-nine babies were born to eclamptic mothers among 7500 deliveries giving incidence of occurrence of 0.77 percent. The perinatal mortality in eclamptic babies was 32.7%, whereas the total perinatal mortality rate amongst all the deliveries was 10.5%. The mothers were treated within Group I--diazepam, Group II i chlorpromazine (largactil), phenargan and diazepam and Group III--largactil, phethidine and phenargan. The mortality rate was 23.8%, 18.8% and 66.6% respectively. The highest number of still-born i.e. six out of 8 occurred in Group III. Hundred percent still-born was noted in 28-32 weeks of gestation and birth weight less than 1.5 kg irrespective of drug regimes. Iargactil potentiates the respiratory depressant effect of pethidine and may cause high rate of still-birth and death after birth.

Value of Mantoux Test in diagnosis of tuberculosis in chronic illness

Total 240 cases of 2-12 years age group who had contact of tuberculosis indirectly or directly and had chronic illness were screened for tuberculosis. Out of 240 cases, 180 cases were diagnosed as tuberculosis. Special emphasis was given on Mantoux Test (M.T.), though the battery of tests were done to diagnose tuberculosis. Out of 180 cases of Tuberculosis, M.T. was Positive in 97 cases (40.41%) and repeat M.T. was done after 3 weeks and was converted to Positive in 20 cases (8.33%). Thus only M.T. help in diagnosis of Tuberculosis in almost 50% of the cases.

Utilization of maternal services in west Bengal

A study was conducted in selected blocks of West Bengal to assess the utilization of available maternal health services specially immunization, antenatal care and other services. Coverage with two doses of tetanus toxoid levels varied between 58.6 to 86.7% but it fell far short of Universal Immunization Programme target of 100%. Drop out rates were slightly higher in the rural areas. It was observed that in 5 out of 7 blocks more than 55% of the deliveries were conducted either at hospital or Primary Health Centre by health personnel. However, untrained dais predominated over the trained dais in conducting deliveries in most of the areas. This indicates the poor availability or utilization of the latter.

Epidemiology of Japanese encephalitis

Seven hundred and sixty-two cases of Japanese Encephalitis (JE) were studied during the last 5 years (1985-1989) in relation to age, sex, religion, nutritional status, living habits, exposure to domestic animals and mosquitos, clinical profile, seasonal variation and mortality pattern. The maximum occurrence was in 1987-1988 and it showed a preponderance in males (51-82%). The disease is progressively decreasing in Muslims (3-7%) and gradually increasing in tribes (25-60%). Children in the age-group of 6-7 years (19-25%) were maximally affected and the disease was rare in infancy. The common features were coma, convulsions, neck rigidity and fever (88-97%). Gastrointestinal manifestations were rare (3.6%) but were associated with the highest mortality. About 80-95% had exposure to domestic animals directly or indirectly and 95% of the patients were not using mosquito nets. The CSF protein and sugar content were normal, with or without slight leucocytosis while the lymphocyte count was variable. The CSF and blood picture had no significant relation with clinical presentation and prognosis.