Human herpesvirus 8 variants.
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Biomedical subjects
Publications and source records attributed to M Tamm.
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Human herpes virus 8 (HHV8) DNA has recently been detected in sarcoma tissue of patients with Kaposi's sarcoma. HHV8 DNA could also be found in bronchoalveolar lavage (BAL) fluid of patients with tracheobronchial Kaposi's sarcoma. To determine the specificity, sensitivity and predictive values of HHV8 DNA detection in the BAL for the diagnosis of pulmonary Kaposi's sarcoma, 100 consecutive BAL were prospectively analyzed for the presence of HHV8 DNA using a nested PCR assay. In addition, 19 BAL samples of 14 AIDS patients with cutaneous or visceral Kaposi's sarcoma were retrospectively investigated. The prospective group consisted of 79 BAL performed in immunocompromised and of 21 BAL in nonimmunocompromised patients. Four patients of the prospectively analyzed group undergoing six BAL showed tracheobronchial Kaposi's sarcoma at five bronchoscopies. All of the five BAL samples performed in these patients with endoscopically visible Kaposi's sarcoma were positive for HHV8 DNA. Following chemotherapy and antiretroviral treatment tracheobronchial Kaposi's sarcoma was no longer detectable at a subsequent bronchoscopy and HHV8 DNA in BAL became negative in one patient. One BAL sample of a HIV-positive patient with no evidence of Kaposi's sarcoma was HHV8 DNA-positive. The sensitivity, specificity, positive and negative predictive values of HHV8 detection for the diagnosis of tracheobronchial Kaposi's sarcoma were 100%, 98.9%, 83.3%, and 100%, respectively. Twelve of 19 BAL samples of the retrospective group were HHV8 DNA-positive. In this group, 10 patients undergoing a total of 14 BAL suffered from pulmonary Kaposi's sarcoma. HHV8 DNA was documented in 10 of these 14 BAL samples. In three BAL of this group HHV8 DNA was positive, but pulmonary Kaposi's sarcoma was diagnosed at a later stage. In conclusion, the detection of HHV8 DNA in BAL is restricted to patients with Kaposi's sarcoma and is highly sensitive and specific for pulmonary involvement of Kaposi's sarcoma.
BACKGROUND: The human herpes virus 8 (HHV8) has been detected in all forms of Kaposi's sarcoma. HHV8 was also reported to be present in epithelial skin tumors of patients after renal transplantation, raising the question of the clinical relevance of HHV8 in transplant-related tumors. METHODS: Using a highly sensitive nested polymerase chain reaction assay, we analyzed for the presence of HHV8-DNA in the tumor tissue of renal transplant recipients with Kaposi's sarcoma (n=2) and non-Hodgkin's lymphomas (n=6), and in 32 tumors from 10 patients with multiple epithelial skin tumors. RESULTS: HHV8-DNA was detected in both cases of Kaposi's sarcoma but not in either the non-Hodgkin's lymphomas or the epithelial skin tumors. CONCLUSIONS: Our data confirm the association of HHV8 with Kaposi's sarcoma but not with other transplant-related tumors. Further studies are needed to analyze the risk for transmission of HHV8 by the donor and the possible exclusion of HHV8-positive patients as organ donors.
BACKGROUND: Pulmonary complications often occur in patients with leukemia and severe aplastic anemia. Particularly in patients having undergone bone marrow transplantation, respiratory diseases account for a significant number of deaths. In a retrospective study, we evaluated 41 patients with leukemia and severe aplastic anemia who were operated on consecutively from 1980 to 1995. METHODS: Fourteen open lung biopsies, four video-assisted lung biopsies, and 24 lung resections were performed in 24 male and 17 female patients. Mean age was 32.2 years. RESULTS: Eleven (27%) early deaths occurred (30-day mortality): ten in patients after lung biopsy (56%) and one after lung resection (4%) (p < 0.001). Perioperative morbidity relating to pulmonary disease or operation included 10 (24.4%) cases of prolonged (> 24 hours) postoperative mechanical ventilation and two (4.8%) cases of bleeding or hematoma. In one (2.4%) patient a slowly developing, contained bronchial stump insufficiency appeared after lobectomy, which was successfully operated on 3 weeks later. CONCLUSION: We conclude that resection of localized pulmonary lesions, be it for diagnostic or therapeutic (or combined) purposes, can be carried out with low morbidity and mortality in patients with leukemia and severe aplastic anemia. However, early mortality is high after open or thoracoscopic lung biopsies in patients with acute-onset diffuse pulmonary disease, and little therapeutic benefit is realized in these cases.
Transbronchial biopsies (TBBs) are useful to diagnose acute rejection and infection in patients with lung transplants. The value of routine surveillance biopsies (S-TBBs) is not known, and such biopsies with a clinical indication are not without risk and are expensive. One hundred twenty-six 6-mo survivors of heart-lung transplantation (HLT) were studied to determine the effect of stopping S-TBBs on the development of bronchiolitis obliterans syndrome (BOS) and subsequent survival. Fifty-one received transplants while S-TBB was part of routine care (group A), and 75 received transplants after this practice was stopped (group B). There was no difference in patient characteristics. Group A had shorter graft ischemia (p < 0.01) and longer postoperative ventilation (p < 0.01). Maintenance immunosuppression was similar, but group A had more steroid pulses in the second 6 mo after HLT (p < 0.01). The number of patients free from any functional deterioration at 49 to 60 mo after HLT declined to 39% in group A and 64% in group B. The risk of developing BOS grade 1 in group A relative to group B was 1.63 (95% confidence intervals: 0.96-2.79, p = 0.07). Patient survival was similar in the two groups. A total of 86 TBBs were taken in the absence of any signs or symptoms and had low diagnostic yield. In summary, there was no increased incidence of BOS after stopping S-TBBs.
The matrix metalloproteinases (MMP) are proteolytic enzymes that are essentially involved in the turnover of the extracellular matrix (ECM). Their activity is counterbalanced by specific antagonists, the tissue inhibitors of metalloproteinases (TIMP). In this study, we sought to analyze the expression of MMP and TIMP isoforms in pleural effusions from 88 patients. We compared MMP and TIMP isoform expression in transudates (n = 21) and exudates (n = 67), the latter divided into exudates of paraneoplastic (n = 46) or parainfectious (n = 21) origin. Zymographic and Western blot analyses revealed constant expression of interstitial collagenase (MMP-1), gelatinase-A (MMP-2), and TIMP-1 in all 88 samples. In contrast, analyses of gelatinase-B (MMP-9) demonstrated a specific expression pattern, with high expression in exudates and lack of expression in transudates. Neutrophil collagenase (MMP-8) was detected in trace amounts, and correlated with the number of neutrophils in the effusion. Low levels of TIMP-2 were detected only in exudates and not in transudates. Quantitative analysis of the expression ratio of gelatinase-B to gelatinase-A revealed statistically significant differences between effusions of different origin. The ratio was highest in exudates of paraneoplastic origin and lowest in transudates. Our data thus suggest that interstitial collagenase, gelatinase-A, and TIMP-1 play a role in homeostasis of the pleural space in vivo as constitutively expressed proteins, whereas gelatinase-B and TIMP-2 expression are induced in specific disease states. These observations contribute to the understanding of the pathophysiology of pleural effusions, and may help to characterize and possibly distinguish effusions of different origin.
Vascular endothelial growth factor (VEGF) is a potent peptide growth factor specific for vascular endothelial cells, which promotes neovascularization and increases vascular permeability in vivo. Enhanced microvascular permeability and edema are common characteristics of inflammatory and neoplastic disorders. Two proinflammatory mediators, platelet-activating factor (PAF) and platelet-derived growth factor (PDGF), are known to contribute to cellular damage and tissue remodeling in a number of lung diseases. To determine whether PAF or PDGF induce VEGF gene expression in primary cultures of human pulmonary fibroblasts and pulmonary vascular smooth-muscle cells (VSMCs), we performed Northern-blot analysis and enzyme-linked immunosorbent assays (EIA). PAF and all three isoforms of PDGF (PDGF-AA, -AB, and -BB) increased VEGF mRNA in a time- and dose-dependent manner. While PAF was shown to increase VEGF mRNA at picomolar concentrations, all PDGF isoforms were effective in inducing VEGF mRNA at nanomolar concentrations. The transcriptional activation was accompanied by increased levels of VEGF protein as determined by EIA in culture medium. These results indicate that VEGF gene expression in VSMCs and fibroblasts is mediated by PAF and/or PDGF isoforms. In a paracrine mode of action, secreted VEGF may then lead to altered endothelial cell functions and vascular hyperpermeability. In the presence of the corticosteroids cortisone, hydrocortisone, dexamethasone, or prednisolone at nanomolar concentrations, this stimulus-dependent transcription of VEGF was abolished. The inhibitory effect of corticosteroids on VEGF expression could explain the clinically well-known antiedematous potency of corticosteroids on a molecular level.
Platelet-activating factor (PAF) is a potent proinflammatory phospholipid mediator of the lung. In this study, we demonstrate that PAF receptor mRNA and protein is expressed by human lung fibroblasts. Interaction of PAF with its specific receptor resulted in increases of tyrosine phosphorylation of several intracellular proteins, indicating that the PAF-receptor might be functionally active. PAF-induced transcription of protooncogenes c-fos and c-jun as well as of interleukin (IL)-6 and IL-8 genes in human fibroblasts. Transcription of the interleukins was followed by secretion of the respective proteins. Moreover, PAF enhanced proliferation of fibroblasts in a concentration-dependent manner. Using signaling inhibitors, we demonstrate that PAF-induced transcription of the c-fos, IL-6, and IL-8 genes, as well as proliferation, require activation of pertussis toxin-sensitive G proteins, tyrosine kinases, and protein kinase C (PKC). In contrast, transcription of c-jun was blocked by pertussis toxin, but not by inhibitors for tyrosine kinases or PKC. These data suggest that PAF stimulates distinct signaling pathways in human lung fibroblasts. In addition, the activation of human fibroblasts by PAF leads to enhanced proliferation and to the expression of proinflammatory cytokines, which may contribute to the pathophysiological changes in pulmonary inflammation.
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Given the internationally recognized definition of bronchiolitis obliterans syndrome (BOS) and longer follow up of heart-lung transplant recipients, it is possible to establish some of the major risk factors for development and progression of BOS. Between April 1984 and 31 December 1993, 157 patients underwent heart-lung transplantation; 126 survived at least six months after operation and so were at risk of developing BOS. The following early risk factors were assessed for development of BOS grade 1 (21-35% decline in FEV1) and progression from grade 1 to grade 2 (36-50% decline in FEV1): age, gender and underlying diagnosis of the recipient, evidence of acute rejection and cytomegalovirus (CMV) infection within 6 months of operation, peak FEV1 achieved, age and gender of the donor, cold ischemic time of the graft, and matching of CMV serological status and HLA antigens of donor and recipient. The number of acute rejection episodes observed remained the single most important determinant of development of BOS grade 1 (relative risk 1.17 (1.06, 1.29), P=0.002) and progression to BOS grade 2 (relative risk 1.58 (1.02, 2.46), P=0.03). No other factors were significantly related to development or progression of BOS, although both evidence of CMV infection and disease and the number of HLA mismatches increased the risk. Bronchiolitis obliterans syndrome is a major problem for medium-to-long-term survivors of cardiothoracic transplantation. Acute rejection early after transplantation is a sensitive prognostic indicator of subsequent functional decline and requires prompt attention.
With the increasing number of successfully performed lung transplants and a longer follow up of patients, there is an interest in the analysis of long-term complications and their impact on patient survival. Heart-lung transplantation was performed in 157 patients with 126 patients surviving at least 6 months. Early death was mainly caused by bacterial and viral infection. Long-term patient survival was decisively influenced by obliterative bronchiolitis. With the new international definition of bronchiolitis obliterans syndrome (BOS) based on an irreversible decline of FEV1 from baseline values, it became possible to analyse the incidence of BOS and the impact on patient mortality in long-term survivors. FEV1 reached a peak value of 102% predicted at a median of 219 days. In 106 of 126 patients (84%), FEV1 showed no decline within the first year. A total of 60 patients (47.6%) developed BOS grade 1 with progression to BOS grade 2 in 85% of these patients. The incidence of BOS was 12.6% at 1 year increasing to more than 50% 5 years after transplantation. Patient mortality due to obliterative bronchiolitis increased from 1% at 1 year to 18% more than 5 years after transplantation. Almost all deaths (86%; 32/37) more than 1 year after HLT were associated with bronchiolitis obliterans. In summary, bronchiolitis obliterans decisively contributes to long-term patient morbidity and mortality after heart-lung transplantation. Clinical and research efforts should be directed towards avoiding this important complication.
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The influence of pulmonary resection on functional capacity can be assessed in different ways. The aim of this study was to compare the effect of lobectomy and pneumonectomy on pulmonary function tests (PFT), exercise capacity and perception of symptoms. Sixty eight patients underwent functional assessment with PFT and exercise testing before (Preop), and 3 and 6 months after lung resection. In 50 (36 males and 14 females; mean age 61 yrs) a lobectomy was performed and in 18 (13 males and 5 females; mean age 59 yrs) a pneumonectomy was performed. Three months after lobectomy, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), total lung capacity (TLC), transfer factor of the lungs for carbon monoxide (TL,CO) and maximal oxygen uptake (V'O2,max) were significantly lower than Preop values, increasing significantly from 3 to 6 months after resection. Three months after pneumonectomy, all parameters were significantly lower than Preop values and significantly lower than postlobectomy values and did not recover from 3 to 6 months after resection. At 6 months after resection significant deficits persisted in comparison with Preop: for FVC 7% and 36%, FEV1 9% and 34%, TLC 10% and 33% for lobectomy and pneumonectomy, respectively; and V'O2,max 20% after pneumonectomy only. Exercise was limited by leg muscle fatigue in 53% of all patients at Preop. This was not altered by lobectomy, but there was a switch to dyspnoea as the limiting factor after pneumonectomy (61% of patients at 3 months and 50% at 6 months after resection). Furthermore, pneumonectomy compared to lobectomy led to a significantly smaller breathing reserve (mean +/- SD) (28 +/- 13 vs 37 +/- 16% at 3 months; and 24 +/- 11% vs 33 +/- 12% at 6 months post resection) and lower arterial oxygen tension at peak exercise 10.1 +/- 1.5 vs 11.5 +/- 1.6 kPa (76 +/- 11 vs 86 +/- 12 mmHg) at 3 months; 10.1 +/- 1.3 vs 11.3 +/- 1.6 kPa (76 +/- 10 vs 85 +/- 12 mmHg) at 6 months postresection. We conclude that measurements of conventional pulmonary function tests alone overestimate the decrease in functional capacity after lung resection. Exercise capacity after lobectomy is unchanged, whereas pneumonectomy leads to a 20% decrease, probably due to the reduced area of gas exchange.
Pulmonary involvement is a clinically important form of visceral Kaposi's sarcoma in immunocompromised patients. Recently, herpesvirus-like deoxyribonucleic acid (DNA) sequences, defining a new herpesvirus termed "human herpesvirus 8" (HHV8) or "Kaposi's sarcoma-associated herpesvirus" (KSHV), were detected in Kaposi's sarcoma of acquired immune deficiency syndrome (AIDS) and non-AIDS patients. We describe the successful detection of HHV8 DNA in the bronchoalveolar lavage (BAL) fluid of patients with pulmonary Kaposi's sarcoma. Three immunocompromised patients, two HIV seropositive and one after kidney transplantation, suffered from respiratory symptoms and showed pulmonary infiltrates on chest radiography after development of biopsy proven Kaposi's sarcoma of the skin. Bronchoscopy revealed the typical Kaposi like livid endobronchial lesions. BAL fluid was analysed for the presence of HHV8 DNA using a nested polymerase chain reaction (PCR) assay. HHV8 DNA was detected in the BAL fluid of all three patients. In addition, HHV8 DNA could be detected in the skin biopsy tissue, lymph node, and peripheral blood mononuclear cells of these patients. Our data show that human herpesvirus 8 deoxyribonucleic acid can be detected in the bronchoalveolar lavage fluid of patients with pulmonary Kaposi's sarcoma. If further studies reveal a high specificity for human herpesvirus 8 deoxyribonucleic acid detection, this test will improve the tools for the diagnosis of pulmonary Kaposi's sarcoma without further need of biopsies.
Human lung transplantation was successfully performed in the early eighties and is now an option for patients with endstage lung disease, which is associated with poor survival. Most frequent indications for lung transplantation are emphysema, cystic fibrosis, fibrosing alveolitis, primary pulmonary hypertension and Eisenmenger's syndrome. Single lung transplantation (SLT) is most often performed in emphysema, fibrosing alveolitis and other diseases which are not associated with chronic infection of the lung. Double lung transplantation was recently replaced by the technique of sequential single lung or bilateral lung transplantation (BLT). Cardiopulmonary bypass can often be avoided and problems of the airway anastomosis are less frequent using BLT. Main indications for this procedure are cystic fibrosis, bronchiectasis and primary pulmonary hypertension (PPH). In PPH often only SLT is performed. Cor pulmonale is reversible following SLT or BLT even if the heart is not replaced. Combined heart-lung transplantation (HLT) is reserved for some cases of Eisenmenger's syndrome and few centers still prefer HLT in patients with cystic fibrosis. Patients are usually accepted for transplantation when they are considered to have life expectancy of 12 to 24 months. Quality of life and physical working capacity are severely decreased and patients suffer dyspnea NYHA grade III or IV. Most of the patients are hypoxic and need continuous oxygen therapy. Hypercapnia is also a negative predictive factor for survival without transplantation. In PPH cardiac index of less than 2 litres/m2 is associated with poor outcome. Not only absolute values for FEV1 and pO2 have to be considered in finding the best moment for assessment for transplantation but the clinical course of the disease during previous months and years also has to be taken into account. Contraindications to transplantation include acute infection, concomitant diseases of other organs, bronchial carcinoma and psychiatric disorders if noncompliance is likely. To achieve good results after lung transplantation, proper donor and recipient selection, experienced surgery and careful postoperative management are essential. Complications must be diagnosed early to provide effective treatment. Most complications occur within the first months after surgery. Early complications include primary organ failure, pleural bleeding, problems at the site of the airway anastomosis, infection and acute rejection. Acute rejection is common but can be treated successfully if diagnosed early.(ABSTRACT TRUNCATED AT 400 WORDS)
Up to 85% of patients with bronchogenic carcinoma are inoperable at the time of diagnosis and treatment remains largely palliative. Prognosis depends on the clinical tumor stage. In non-small cell carcinoma the clinical stages (I-IV) are defined according to the TNM classification, whereas in small cell carcinoma limited disease is distinguished from extensive disease. Neither classification accurately takes endobronchial tumor spread into account. At the time of diagnosis up to 30% of all lung cancer patients present with central airway obstruction and clinical signs of dyspnea, atelectasis and pneumonia. Most patients with central airway stenosis have inoperable tumors (stage IIIb and IV) and have until recently undergone conventional treatment consisting exclusively of chemo- and radiotherapy. Currently the best results are obtained with combined chemoradiotherapy. The rapid developments in the area of endobronchial treatment modalities enable us to relieve bronchial obstructions fast and safely. This achieves immediate symptomatic relief which in many cases is a precondition for starting chemo- or radiotherapy. Successful reopening of a major airway helps to prolong local tumor control and thus survival. Patients with inoperable lung cancer and obstruction of central airways should undergo initial endobronchial therapy followed by conventional chemo-radiotherapy.
This is an overview for the non-specialist of the pathophysiology, workup and treatment of the obstructive sleep apnea syndrome. The mechanisms leading to upper airway closure during sleep are discussed, as well as the current theoretical and experimental concepts for the apnea-induced arousal response and the consequent changes in sleep architecture and quality. Epidemiological data are summarized, with special reference to the problems of non-uniform definition criteria and examination techniques applied. In conclusion, a practical workup strategy and the current treatment options are summarized.