One-stage coronary and abdominal aortic operation with or without cardiopulmonary bypass: early and midterm follow-up

BACKGROUND

The aim of this study was to compare hospital, early, and late clinical outcomes for patients undergoing one-stage, coronary and abdominal aortic surgical intervention with and without cardiopulmonary bypass.

METHODS

From March 1990 to September 1999, 42 consecutive patients underwent combined operations at a single institution. Cardiopulmonary bypass and cardioplegic arrest were used during coronary revascularization in the first 20 patients (on-pump group), and the next 22 patients received the one-stage operations on the beating heart (off-pump group).

RESULTS

Baseline characteristics were similar between groups. Three cardiac-related hospital deaths occurred in the on-pump group and one such death in the off-pump group (p = 0.25). Cardiac-related events, pulmonary complications, inotropic support, blood loss and transfusion requirements, intensive care unit stay, and hospital stay were significantly reduced in the off-pump group (all, p < 0.05). The actuarial survival rates in the on-pump and off-pump groups were 80% and 95%, respectively, at 1 year (p = 0.13) and 75% and 89%, respectively, at 3 years (p = 0.22). Freedom from cardiac-related events at 1-year follow-up was 91% in the off-pump group and 65% in the on-pump group (p < 0.05). No difference in cardiac-related events between groups was observed at 3 years.

CONCLUSIONS

Off-pump coronary surgical procedures decrease postoperative complications in high-risk patients undergoing simultaneous coronary and abdominal aortic operations compared with the conventional one-stage procedure. The early benefits achieved with off-pump surgical intervention are not at the expense of the long-term clinical outcome.

Community-acquired pneumonia in patients requiring hospitalization

OBJECTIVE

This study aimed to investigate the microbial aetiology of community-acquired pneumonia (CAP) in patients requiring hospitalization.

METHODOLOGY

A prospective study of consecutive non-immunocompromised patients aged 12 years and above admitted with CAP from August 1997 to May 1999 was undertaken.

RESULTS

Of 127 patients hospitalized for CAP, an aetiological diagnosis was achieved in 53 cases (41.7%). Klebsiella pneumoniae was the most frequently isolated pathogen and caused 10.2% of all the cases, followed by Streptococcus pneumoniae (5.5%), Haemophilus influenzae (5.5%), Mycoplasma pneumoniae (3.9%) and Pseudomonas aeruginosa (3.9%). Gram-negative bacilli were significantly more frequently identified in patients aged 60 years or older and in patients with comorbid illnesses. Twelve of 13 patients who died from CAP had other comorbid illnesses compared to 63 of 114 patients who survived (P = 0.014). Three of eight bacteraemic patients died compared with 10 of 119 non-bacteraemic patients (P = 0.035).

CONCLUSIONS

The microbiology of CAP in patients requiring hospitalization in Malaysia appears to be different from that in Western countries. Gram-negative bacilli were more frequently isolated in older patients and in those with comorbidity. Mortality from CAP is more likely in patients with comorbidity and in those who are bacteraemic.

Occlusive myocardial infarction: investigation of bis-gadolinium mesoporphyrins-enhanced T1-weighted MR imaging in a cat model

PURPOSE

To test whether bis-gadolinium mesoporphyrins-enhanced magnetic resonance (MR) imaging can accurately depict irreversibly damaged myocardium in occlusive myocardial infarction.

MATERIALS AND METHODS

Ten cats were subjected to 90 minutes of occlusion of the left anterior descending coronary artery. Bis-gadolinium mesoporphyrins-enhanced T1-weighted MR imaging was performed in the cats for 6 hours. Histopathologic examinations with 2'3'5-triphenyl tetrazolium chloride (TTC) staining and electron microscopy were performed on the resected specimens. The time course and pattern of signal intensity enhancement were evaluated. The size of the infarcted myocardium was estimated on the MR images by measuring the size of the signal intensity-enhanced area.

RESULTS

In eight of 10 cats, it was impossible to distinguish infarcted myocardium from normal myocardium at visual inspection of T1-weighted MR images. The contrast ratio between infarcted and normal myocardium did not increase significantly over time. In one of the two remaining cats, a doughnut pattern of signal intensity enhancement was noted. The other cat showed intensely homogeneous enhancement of infarcted myocardium at MR imaging. The size of the area of signal intensity enhancement at MR imaging in these two cats was accurately mapped to that of the infarction on the TTC-stained specimens.

CONCLUSION

Occlusive myocardial infarction cannot be accurately detected at bis-gadolinium mesoporphyrins-enhanced MR imaging.

Relationship between symptoms and objective measures of airway obstruction in asthmatic patients

The objective of this study was to determine the relationship between asthma symptoms and the degree of airway obstruction as measured by the forced expiratory volume in one second (FEV1) and peak expiratory flow rate (PEFR) in a group of 64 asthmatic patients with clinically stable disease attending a university-based urban asthma clinic. Asthma symptoms did not correlate with the degree of airway obstruction as measured by prebronchodilator PEFR (total asthma symptom score vs PEFR: r = -0.214, p = 0.104, n = 59) and only correlated poorly with prebronchodilator FEV1 (total asthma symptom score vs FEV1: r = -0.256, p = 0.041, n = 64). These results lend support to the recommendation that airway obstruction should be measured objectively when assessing patients with chronic persistent asthma.

Histocompatibility leukocyte antigen-G is not expressed by endometriosis or endometrial tissue

OBJECTIVE

The immunological mechanisms that support persistence and proliferation of ectopic endometrial implants within the peritoneal cavity of women with endometriosis are unknown. Inhibition of natural killer (NK) and cytotoxic T-cell function has been proposed as a mechanism. We tested the hypothesis that expression of a nonclassical major histocompatibility antigen, HLA-G, might explain the local immunosuppression associated with ectopic endometrium.

DESIGN

Nested case-control study of women with and without laparoscopic evidence of endometriosis.

SETTING

Reproductive endocrinology clinic at a university hospital.

PATIENT(S)

Peritoneal fluid specimens from 10 women with revised AFS stage I-IV endometriosis and from 10 age-matched normal controls without laparoscopic evidence of endometriosis were tested for the presence of HLA-G protein. Endometriosis and normal endometrial biopsies from four patients were used to prepare stromal cell cultures directly evaluated for HLA-G protein.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The expression of HLA-G in peritoneal fluid, tissue, and cell cultures was determined by immunoblotting with a specific monoclonal antibody.

RESULT(S)

HLA-G protein was not detectable in peritoneal fluid specimens of endometriosis patients or controls. Moreover, ectopic and normal endometrial tissues and stromal cells did not express HLA-G.

CONCLUSION(S)

Immune cell inhibition in endometriosis must be mediated by factors other than HLA-G.

Awake respiratory function in patients with the obstructive sleep apnoea syndrome

INTRODUCTION

The flow-volume curves of patients with obstructive sleep apnoea (OSA) obtained during the awake state are frequently abnormal.

OBJECTIVE

To determine 1) the relationship between the awake respiratory function and the severity of sleep-disordered breathing in a group of Malaysian patients with the OSA syndrome and 2) the frequency of flow-volume curve abnormality in these patients.

MATERIALS AND METHODS

A retrospective analysis of the data from respiratory function tests during wakefulness and nocturnal polysomnography was performed on 48 patients with OSA. The severity of OSA was defined by the apnoea-hypopnoea index (AHI) and the lowest oxygen saturation during sleep (SpO2nadir).

RESULTS

AHI had a significant relationship with alveolar-arterial oxygen gradient (r = 0.34, p = 0.046) and SpO2nadir (r = -0.49, p < 0.001) but not with any anthropometric parameter or the other awake respiratory function variables measured. SpO2nadir had a significant relationship with body mass index (r = -0.54, p < 0.001), neck circumference (r = -0.39, p = 0.013), awake room air PaO2 (r = 0.61, p < 0.001), alveolar-arterial oxygen gradient (r = -0.41, p = 0.015) and baseline supine SpO2 (r = 0.53, p < 0.001). There was no correlation between SpO2nadir and any spirometric or static lung volume parameters. The maximum inspiratory and maximum expiratory flow-volume curves of 26 patients (54%) showed a ratio of forced expiratory flow to forced inspiratory flow at mid-vital capacity (FEF50/FIF50) greater than one. In addition, flow oscillations (the "sawtooth" sign) were noted in the inspiratory and/or expiratory flow-volume curves of 21 patients (44%), 9 of whom did not have an FEF50/FIF50 > 1. Altogether, the maximum flow-volume curves during wakefulness of 35 (73%) of the 48 patients showed variable upper airway obstruction and/or flow oscillations. However, the presence of these two upper airway abnormalities, either occurring alone or together did not have an effect on the severity of OSA as measured by the AHI or SpO2nadir.

CONCLUSIONS

Abnormalities of the flow-volume loop consistent with inspiratory flow limitation and/or upper airway instability during wakefulness are common in patients with the OSA syndrome. The degree of oxygen desaturation during sleep in these patients is related to their awake oxygenation status.

Lung cancer in patients younger than 40 years in a multiracial Asian country

OBJECTIVE

This study aimed to determine whether the clinicopathological features of lung cancer in patients younger than 40 years differ from that of older patients in an Asian country.

METHODOLOGY

We undertook a review of the clinicopathological data of all patients with confirmed primary lung cancer at the Department of Medicine, University of Malaya Medical Centre, Kuala Lumpur, Malaysia, from October 1991 to September 1999.

RESULTS

Of the 580 patients with lung cancer, 36 (6.2%; 23 males, 13 females) were 21-39 years old at diagnosis. The percentage of people who had never smoked was higher among the younger patients (58.3% vs 19.1%, P < 0.001). Although adenocarcinoma was the most common cell type in both groups, its incidence was higher in the younger patients (24/36 (66.7%) vs 228/544 (41.9%), P = 0.007). The mean World Health Organization performance status at presentation was worse in the younger patients (2.4 vs 2, P = 0.007). In the case of non-small cell lung cancer, all the younger patients presented with either stage IIIb or metastatic disease compared to 77.2% of the older patients (P < 0.001).

CONCLUSIONS

Younger lung cancer patients were more likely than older patients to have never smoked, to have adenocarcinoma, and to present with poorer performance status and with more advanced-stage non-small cell lung cancer.

Placental peroxisome proliferator-activated receptor-gamma is up-regulated by pregnancy serum

Lipid metabolism plays an important role in normal pregnancy adaptation and in pathological pregnancy (e.g. preeclampsia). In the current studies we examined the expression of peroxisome proliferator-activated receptor-gamma (PPARgamma) in tissues and cells relevant to human pregnancy. We found that PPARgamma is expressed in placental cytotrophoblasts in vivo and in trophoblasts (primary and choriocarcinoma cells) and fetal endothelial cells in vitro. We characterized primary cytotrophoblasts and two cell lines with which to study PPARgamma regulation in human pregnancy. Like primary cytotrophoblasts, the choriocarcinoma cell line JEG-3 has endogenous PPARgamma expression. Normal positive and negative PPARgamma regulation was observed in the latter cells. We also created a new JEG-3-derived cell line (EP-JEG) by stable insertion of a PPAR response element-luciferase reporter gene construct. Together, these cell lines are useful for studying PPARgamma expression and activation in human trophoblasts. We examined PPARgamma regulation in these cells by human serum and found that PPARgamma protein expression and activation are dramatically increased by sera from pregnant women. Preliminary characterization of the regulatory principle(s) is consistent with a prostanoid or fatty acid derivative. The results suggest that increased activation of PPARgamma may play an important role in maternal metabolism during human pregnancy.

Intravenous followed by oral ofloxacin in the treatment of community acquired lower respiratory tract infections in adults requiring hospitalisation

Forty patients were treated with ofloxacin for community acquired lower respiratory tract infections. Eighteen pathogens were isolated in sputum; Streptococcus pneumoniae (4) and Haemophilus influenzae (4) were the most common, followed by Klebsiella pneumoniae (3), Klebsiella spp. (2), Staphylococcus anreus (2), Pseudomonas spp. (2), and Pseudomonas aeruginosa (1). Ofloxacin 200 mg every 12 hours was administered for an average of 3.7 days intravenously followed by 5.4 days orally. Response to therapy was judged to be cure in 38 (95%; 95% C.I., 85%-95%) patients, failure in one (2.5%) and "indeterminate" in one (2.5%).

Acceptance of the Accuhaler, a multi-dose powder inhaler, among asthmatic patients: a comparison with the pressurized metered-dose inhaler

This study aimed to evaluate dry powder inhaler naive asthmatic patients' perception and preference of the Accuhaler, a multidose dry powder inhaler and the pressurized metered dose inhaler (pMDI). After the first instruction, 66.7% of 48 patients enrolled in the study could demonstrate the correct use of the Accuhaler. When the patients were asked to compare the pMDI and the Accuhaler after using the Accuhaler to administer salmeterol for 4 weeks, the Accuhaler scored significantly better than the pMDI for the following features: knowing how many doses are left, presence of an attached cover, taste, instruction for use, attractiveness, ease of use, ease of holding, shape, and comfortable mouthpiece. The pMDI scored better to the Accuhaler in terms of size. More patients preferred the Accuhaler than the pMDI; the presence of a dose counter and perceived ease of use were the main reasons cited for their preference for the Accuhaler.

Taraxacum officinale inhibits tumor necrosis factor-alpha production from rat astrocytes

Substance P (SP) can stimulate production of tumor necrosis factor-alpha (TNF-alpha) from astrocytes stimulated with lipopolysaccharide (LPS). The objective of the current study was to determine the effect of Taraxacum officinale (TO) on the production of TNF-alpha from primary cultures of rat astrocytes. TO (100 and 1000 microg/ml) significantly inhibited the TNF-alpha production by astrocytes stimulated with LPS and SP. Interleukin-1 (IL-1) has been shown to elevate TNF-alpha production from LPS-stimulated astrocytes while having no effect on astrocytes in the absence of LPS. We therefore examined whether IL-1 mediated inhibition of TNF-alpha production from primary astrocytes by TO. Treatment of TO (100 and 1000 microg/ml) to astrocytes stimulated with both LPS and SP decreased IL-1 production significantly. Moreover, the production of TNF-alpha by LPS and SP in astrocytes was progressively inhibited with increasing amount of IL-1 neutralizing antibody. Our results suggest that TO may inhibit TNF-alpha production by inhibiting IL-1 production and that TO has an antiinflammatory activity in the central nervous system.

Irreversibly damaged myocardium at MR imaging with a necrotic tissue-specific contrast agent in a cat model

PURPOSE

To investigate the capability of a necrosis-avid magnetic resonance (MR) contrast agent, bis-gadolinium mesoporphyrins, for assessment of irreversibly damaged myocardium and to evaluate the time course of signal enhancement in the reperfused myocardium.

MATERIALS AND METHODS

Nine cats were subjected to 90 minutes of occlusion of the left anterior descending coronary artery followed by 90 minutes of reperfusion. Contrast material-enhanced T1-weighted spin-echo images were obtained for 12 hours in five cats and 6 hours in four cats. Pathologic examinations of the resected specimens were performed with 2'3'5-triphenyl tetrazolium chloride (TTC) histochemical staining and electron microscopy. The size of enhanced area on MR images was compared with that of irreversibly damaged myocardium with TTC staining. The time course of signal enhancement was evaluated.

RESULTS

The size of enhanced area on MR images was well correlated with that of irreversibly damaged myocardium with TTC staining. Maximum enhancement occurred 1-3 hours after administration of the contrast material, with mean enhancement of 171% that of normal myocardium. Electron microscopic examinations showed severe myocardial damage in the irreversibly damaged myocardium but only mild edematous changes in the reversibly damaged myocardium.

CONCLUSION

MR images enhanced with bis-gadolinium mesoporphyrins provide accurate sizing of irreversibly damaged myocardium with a strong and persistent signal enhancement in the reperfused myocardium.

Pulmonary siderosis in an arc welder

An asymptomatic subject with radiographic changes due to welders' siderosis is described. This condition has not been well recognized and described in our community. Siderosis of the lung is generally considered to be a benign condition not associated with respiratory symptoms. However, recent reports have associated welding with various disorders of pulmonary function as well as lung cancer. There is a need for future epidemiological studies to better define the risk of long term welding.

Application of breath-hold T2-weighted, first-pass perfusion and gadolinium-enhanced T1-weighted MR imaging for assessment of myocardial viability in a pig model

The purpose of this study was to correlate the abnormal signal area on various magnetic resonance (MR) images to the infarct area on pathologic examination and to assess the myocardial viability on the basis of MR images. T2-weighted, first-pass perfusion, and delayed gadolinium-enhanced T1-weighted images were used as "one-stop examinations" in a pig model of reperfused myocardial infarction. The results of each MR image were compared with those of 2,3, 5-triphenyltetrazolium chloride (TTC) staining. The abnormal signal areas on T2-weighted and Gd-enhanced T1-weighted images were larger than the infarct areas on TTC staining (34.7% and 32.3% vs. 28.3%; P< 0.05), whereas the nonperfused areas on perfusion images were correlated (25.6% vs, 28.3%; P = 0.139). Electron microscopic examination showed severely distorted ultrastructures in the infarct areas and mildly damaged ultrastructures in the peri-infarct areas. Perfusion images probably reflected the infarct areas, whereas T2-weighted and Gd-enhanced T1-weighted images seemed to include peri-infarct as well as infarct areas.

Differences in pleural fluid characteristics, white cell count and biochemistry of tuberculous and malignant pleural effusions

Tuberculosis and malignancy are two common causes of exudative pleural effusions. In this retrospective study of 52 patients with tuberculous pleural effusions and 32 patients with malignant effusions, the median age of patients with malignant effusions (68.5 years) was older than that of patients with tuberculous effusions (34.5 years) (p < 0.001). Both types of effusion occurred more frequently on the right side and there was no difference between them in terms of right-sided dominance. A higher percentage of patients with malignant pleural effusions (44%) presented with large effusions than patients with tuberculous effusions (12%) (x2 = 11.33, p = 0.001). A higher proportion of patients with tuberculous effusion had lymphocyte predominant effusions and tuberculous effusions had higher lymphocyte percentage, lower red cell count, and higher protein content. However, there was considerable overlap of these characteristics of both types of effusions.

Causes of pleural exudates in a region with a high incidence of tuberculosis

OBJECTIVE

To define the causes of exudative pleural effusions in our region.

METHODOLOGY

A retrospective study was performed on consecutive patients with exudative pleural effusion seen in our hospital during a 4-year period.

RESULTS

Of 186 patients with a mean age (+/- SD) of 51.2 (+/- 19.2) years with exudative pleural effusions, 131 (70.4%) were males and 55 (29.6%) were females. The most frequent cause of exudative pleural effusions was tuberculosis (44.1%), followed by malignancy (29.6%). The majority (94.5%) of malignant pleural effusions were due to lung cancer. Apart from a patient with bilateral pleural effusions due to cryptococcosis, patients with tuberculous pleural effusion (mean age (+/- SD), 39.7 (+/- 17.5)) were significantly younger than the rest (P < 0.05). Tuberculous effusions were most frequent in the first five decades (60/82, 73.2%) and were the most common type of pleural effusion, accounting for 60 (69.8%) of 86 cases, in this age range. Malignant effusions were more frequent among the older age groups, 74.5% (41/55) of patients with malignant effusions being older than 50 years. Most types of pleural effusions showed a preference for the right side. Of the 44 cases of large effusions, 28 (63.6%) were caused by malignancy.

CONCLUSIONS

In our region with a high incidence of tuberculosis, the most frequent cause of pleural exudates is tuberculosis followed by malignancy, particularly lung cancer.

Protection of hearts from reperfusion injury by propofol is associated with inhibition of the mitochondrial permeability transition

OBJECTIVE

Diminishing oxidative stress may protect the heart against ischaemia-reperfusion injury by preventing opening of the mitochondrial permeability transition (MPT) pore. The general anaesthetic agent propofol, a free radical scavenger, has been investigated for its effect on the MPT and its cardioprotective action following global and cardioplegic ischaemic arrest.

METHOD

Isolated perfused Wistar rat hearts were subjected to either warm global ischaemia (Langendorff) or cold St. Thomas' cardioplegia (working heart mode) in the presence or absence of propofol. MPT pore opening was determined using [3H]-2-deoxyglucose-6-phosphate ([3H]-DOG-6P) entrapment. The respiratory function of isolated mitochondria was also determined for evidence of oxidative stress.

RESULTS

Propofol (2 micrograms/ml) significantly improved the functional recovery of Langendorff hearts on reperfusion (left ventricular developed pressure from 28.4 +/- 6.2 to 53.3 +/- 7.3 mmHg and left ventricular end diastolic pressure from 52.9 +/- 4.3 to 37.5 +/- 3.9 mmHg). Recovery was also improved in propofol (4 micrograms/ml) treated working hearts following cold cardioplegic arrest. External cardiac work on reperfusion improved from 0.42 +/- 0.05 to 0.60 +/- 0.03 J/s, representing 45-64% of baseline values, when compared to controls (P < 0.05). Propofol inhibited MPT pore opening during reperfusion, [3H]-DOG-6P entrapment being 16.7 vs. 22.5 ratio units in controls (P < 0.05). Mitochondria isolated from non-ischaemic, propofol-treated hearts exhibited increased respiratory chain activity and were less sensitive to calcium-induced MPT pore opening.

CONCLUSION

Propofol confers significant protection against global normothermic ischaemia and during cold cardioplegic arrest. This effect is associated with less opening of mitochondrial MPT pores, probably as a result of diminished oxidative stress. Propofol may be a useful adjunct to cardioplegic solutions in heart surgery.

The presentation of elderly people at an emergency department in Singapore

OBJECTIVE

This study aims to provide demographic and clinical data of elderly people attending one of the hospital emergency departments in Singapore.

DESIGN

Patients aged 60 years and above who attended the Emergency Department (ED) at Alexandra Hospital, Singapore, during 4 randomly selected one-week periods in 1996 were retrospectively studied.

MAIN OUTCOME MEASURES

Patient profile; presenting symptoms; diagnoses; types of investigations done, and outcome following attendance.

RESULTS

A total of 455 ED attendance cards were analysed. The age of patients ranged from 60 to 102 years with a mean age of 72.8 years. Two hundred and sixty-one (57.4%) were males and 194 (42.6%) were females. Four hundred and twenty-seven (93.9%) were emergencies, 25 (5.5%) were non-emergencies and in 3 (0.6%) the priority rating was unknown. Two hundred and ninety (63.7%) were admitted, of whom 166 (57.2%) were males. One (0.2%) was admitted for social reason. The 3 most common symptoms were abnormalities of breathing (10.6%), falls (9.4%) and musculoskeletal pain (8.2%). Majority had 1 (40.4%) or 2 (41.6%) symptoms. The symptoms were mainly acute (1 day, 45.2%) or less than a week (25.7%). The 3 most common diagnoses were chest infection or pneumonia (8.2%), non-fracture head injury (7.2%) and heart failure (6.6%). Most patients (90.5%) had only 1 diagnosis. The 3 most common tests done were chest X-ray (172 patients, 37.8%), electrocardiography (119 patients, 26.2%) and blood glucose (86 patients, 19.0%). One hundred and twenty (26.4%) patients did not require any investigation.

CONCLUSION

The elderly constituted 12.4% of attendance at the ED but formed 34.5% of admissions. They were more likely to have emergency problems. Understanding the common presenting symptoms and diagnoses of the elderly will help doctors at the ED provide better care. Elderly patients with complex problems who are not hospitalised would probably benefit from further geriatric assessment.

Tuberculous pleurisy as a manifestation of primary and reactivation disease in a region with a high prevalence of tuberculosis

SETTING

A teaching hospital in Malaysia.

OBJECTIVE

To review the demographic and clinical features of patients with pleural tuberculosis (TB).

DESIGN

Retrospective chart and chest radiograph review.

RESULTS

The chest radiograph of 54 (61.4%) of a total of 88 patients with pleural TB did not show any lung infiltrate (considered a manifestation of primary TB), while that of 32 (36.3%) patients showed infiltrates in the upper lobes or superior segment of the lower lobes, or the presence of parenchymal scarring in the upper lobes (typical of reactivation TB). Additionally, the chest radiograph of two (2.3%) patients showed miliary mottling (also classified as having primary TB). The mean age of patients with primary versus reactivation tuberculous pleurisy was 36.3 (+/-14.8) years and 44.6 (+/-19.3) years, respectively (P = 0.041). The median duration of symptoms before presentation was 14 days and 60 days in patients with primary and reactivation disease, respectively (P = 0.001).

CONCLUSION

In Malaysia, where the prevalence of TB is high, tuberculous pleurisy is more commonly a manifestation of primary rather than reactivation disease. Patients with primary TB pleurisy are younger and have a shorter duration of symptoms than those with reactivation TB pleurisy.