Joost Weyler

Does the use of antibiotics in early childhood increase the risk of asthma and allergic disease

One of the mechanisms evoked to explain the increasing prevalences of asthma and allergy, in particular among children, is the ‘Western lifestyle’ or ‘hygiene’ hypothesis. As early childhood infections are assumed to hold a protective effect on the development of asthma and allergies, the use of antibiotics at that sensitive age may lead to an increased risk of asthma and allergy.

Prognostic value of bcl-2 expression in invasive breast cancer.

Expression of the bcl-2 proto-oncogene was studied immunohistochemically in 251 invasive ductal breast carcinomas (median follow-up time 91 months, range 24-186 months) and the results were correlated with clinicopathological data and prognostic variables. Sixty-three (25%) tumours were scored bcl-2 negative and 188 (75%) tumours were bcl-2 positive. No relationship could be observed between bcl-2 status and tumour grade, pTNM staging or menopausal status. A strong positive relationship was demonstrated between bcl-2 immunoreactivity and oestrogen receptor status (P < 0.001) and progesterone receptor status (P < 0.001). No prognostic value was demonstrated for bcl-2 expression on disease-free survival and overall survival in axillary node-negative breast cancer patients. However, in axillary node-positive breast cancer patients multivariate analysis demonstrated absence of bcl-2 expression to be independently related to shortened disease-free survival (P = 0.003) and shortened overall survival (P < 0.001). Our results suggest a potential important role for bcl-2 expression as a modulator of response to adjuvant therapy in breast cancer.

Angiogenic cytokines in mesothelioma: a study of VEGF, FGF-1 and -2, and TGF ? expression

Vascular endothelial growth factor (VEGF), acidic and basic fibroblast growth factors (FGF‐1 and ‐2), and transforming growth factor β (TGFβ) are potent angiogenic cytokines. Malignant mesothelioma of the pleura presents with a high intra‐tumoural microvascular density (IMD) which also has prognostic relevance. This study was designed to verify the immunohistochemical expression of the angiogenic cytokines in mesothelioma as well as in non‐neoplastic human mesothelial cells and to study the individual as well as the combined expression of these cytokines in mesothelioma in relation to both IMD and prognosis. In addition, four mesothelioma cell lines were studied by ELISA for the secretion of VEGF and FGF‐2 in their supernatants and were shown to contain high levels of both of these cytokines. Immunohistochemically, VEGF, FGF‐1 and ‐2, and TGFβ immunoreactivity was present in 81, 67, 92 and 96 per cent of mesotheliomas, and in 20, 50, 40, and 10 per cent of samples of the non‐neoplastic mesothelium, respectively. Co‐ordinate expression of the cytokines was observed whereby mesotheliomas expressed more than one cytokine. The combined immunohistochemical expression levels for all four cytokines correlated significantly with both IMD ( p=0·01) and prognosis ( p=0·0013). When studied individually, high FGF‐2 expression correlated best with more tumour aggressiveness and worse prognosis for mesothelioma ( p=0·0011). There was no significant correlation between prognosis and immunoexpression of VEGF ( p=0·07), FGF‐1 ( p=0·3), or TGFβ ( p=0·1), or between IMD and any of the cytokines studied individually. These data support the assertion that selective angiogenic cytokines might contribute to the progressive changes of mesothelioma by tumour angiogenesis. Copyright

MR mammography in the pre-operative staging of breast cancer in patients with dense breast tissue: comparison with mammography and ultrasound

The aim of this study was to determine whether pre-operative MR mammography could predict the extent of breast cancer in patients with dense breasts or whether dense parenchyma will lead to false-positive or inconclusive examinations. Sixty-seven patients with dense breasts with a malignant breast tumor planned for conservative surgery were reviewed. Detection rates of mammography, ultrasound, and MR mammography were studied, and the diameters of the lesions were measured and compared with pathological examination. Pathology revealed breast cancer in 65 patients. Sensitivity for detection of index lesions was 83% for mammography, 70.8% for ultrasound, and 98% for MR mammography. Mammography underestimated tumor extent in 37%, ultrasound in 40%, and MR in 12.5%. Of the 20 patients (31%) with multifocal or multicentric carcinoma, mammography detected the lesions in 35%, ultrasound in 30%, and MR in 100%, with a false-positive rate of 12.5, 14, and 23%. The MR mammography is more accurate in assessing tumor extent and multifocality in patients with dense breasts, but benign changes may lead to false-positive examinations.

Prospective study of intratumoral microvessel density, p53 expression and survival in colorectal cancer

SummaryAdjuvant treatment of patients with colorectal cancer is hampered by a lack of reliable prognostic factors in addition to the clinicopathological staging system. A poorly defined but considerable fraction of Astler–Coller stage B patients will experience tumour recurrence, and some of the stage C patients will probably survive for a prolonged time after surgery without adjuvant treatment. Assessing parameters related to tumour angiogenesis has provided valuable prognostic information in different tumour types. The formation of new microvessels is part of the malignant phenotype in the majority of tumours. Alterations in tumour-suppressor genes, such as the p53 gene, or oncogenes, such as the ras gene, have been found to be responsible for changing the local balance of pro- and antiangiogenic factors in favour of the former. In this prospective study, intratumoral microvessel density (IMD) was assessed by immunostaining tissue sections for CD31 and counting individual microvessels in selected and highly vascular regions in specimens of 145 colorectal cancer patients. p53 protein overexpression was semiquantitatively determined after immunohistochemistry. In both uni- and multivariate analysis, high IMD was significantly associated with shorter survival in the patients undergoing surgery with curative intent (Astler–Coller stages A–C). p53 added prognostic power to IMD, both in Astler–Coller stage B and stage C patients. An association between IMD and mode of metastasis was also noted. High IMD was strongly associated with the incidence of haematogenous metastasis during follow-up, but not with the presence of lymphogenic metastasis observed at surgery. This study confirms the results of previous retrospective analyses of IMD and survival in colorectal cancer and warrants a clinical validation by randomizing stage B tumour patients with high IMD and p53 overexpression between adjuvant treatment or not.

Herpes simplex virus in the respiratory tract of critical care patients: a prospective study

BACKGROUND Herpes simplex virus (HSV) is occasionally detected in the lower respiratory tract of patients in intensive care, but its clinical importance in such situations remains unclear. We did a prospective cohort study to define the prevalence, origin, risk factors, and clinical relevance of HSV in the respiratory tract of patients undergoing critical care. METHODS We tested 764 patients admitted to intensive care for the presence of HSV in the respiratory tract, and assessed statistical relations between this virus and clinical variables. FINDINGS HSV was detected by oropharyngeal swab in the upper respiratory tract of 169 (22%) of 764 patients, within 10 days of admission for 150 (89%) of these individuals. The virus was isolated in 58 (16%) of 361 patients whose lower respiratory tract was sampled. The presence of HSV in the throat was a risk factor for development of HSV infections in the lower respiratory tract (p<0.001). HSV was isolated most frequently in patients with severe disease. HSV in the throat was associated with acute respiratory distress syndrome (p<0.001) and with increased length of stay in intensive care (p<0.001). INTERPRETATION Our data suggest that HSV reactivation or infection of the upper respiratory tract is frequent among patients in intensive care, and is a risk factor for development of lower respiratory tract infection with this virus, possibly by means of aspiration.

Syndecan‐1 expression in malignant mesothelioma: correlation with cell differentiation, WT1 expression, and clinical outcome

Syndecan‐1 binds basic fibroblast growth factor (bFGF), modulates neovascularization, plays a role in epithelial differentiation and is up‐regulated by WT1. Malignant mesothelioma of the pleura is one of the most aggressive tumours known and expresses high levels of angiogenic growth factors. This study has analysed syndecan‐1 expression in mesothelioma tumours and cell lines by immunohistochemistry and immunoblotting, using anti‐syndecan‐1 antibody directed against the core protein, and has examined its relation to morphology, bFGF, WT1, and intra‐tumoural microvascular density (IMD). Shedding of syndecan‐1 in the conditioned medium of mesothelioma cell lines was detected in variable amounts. These studies indicate that (1) there is no correlation of syndecan‐1 with either bFGF expression or IMD in mesotheliomas in vivo; (2) syndecan‐1 is strongly expressed in the epithelial type of mesothelioma and in the epithelial component of biphasic mesotheliomas and the expression is reduced or lost in sarcomatoid differentiation; together with the finding that (3) syndecan‐1 correlates with WT1 immuno‐expression, this suggests that syndecan‐1 might relate to the differentiation state of mesothelial/mesothelioma cells; and (4) syndecan‐1‐positive tumours are associated with a longer survival (p =0·02) than mesotheliomas with no or little syndecan‐1 expression, on univariate analysis. These findings therefore indicate that syndecan‐1 can be an important prognostic indicator in mesotheliomas and its loss may be important in the epithelial–mesenchymal transformation of mesothelioma cells. Copyright

Early distant relapse in ‘node‐negative’ breast cancer patients is not predicted by occult axillary lymph node metastases, but by the features of the primary tumour

Early distant relapse occurs in a minority of node‐negative breast cancer patients. Whether this poor prognosis can be predicted by the features of the primary tumour, or by the presence of occult metastases in the ‘negative’ lymph nodes (LNs), remains a matter of debate. One hundred and four T1–2N0M0 breast carcinoma patients were divided into two groups: group 1 (44%) showing early distant relapse with a median disease‐free survival of 25 months, and group 2 (56%) showing no evidence of disease after a median follow‐up of 91.5 months. All patients had received locoregional treatment only. All tumours were evaluated for medial/lateral location, histological type, size, grade, mitotic activity, fibrotic focus, necrosis, angiogenesis, growth pattern, and lymphatic vessel permeation. The haematoxylin and eosin‐stained slides of all axillary LNs were revised and two additional levels were cut from each paraffin block for cytokeratin immunohistochemistry. In 24 patients (23%), occult metastases were found. These consisted of single cells or small clusters (SCs) in the marginal sinus in 17 patients (16%) and of larger colonies of cells in seven patients (7%). All detected metastases were smaller than 2 mm in diameter (micrometastases). There was no significant correlation between the presence of occult LN metastases (SCs or colonies) and the prognostically important features of the primary tumour. Early metastatic disease was significantly correlated with larger tumour size (p=0.02), higher histological grade (p=0.0008), mitotic activity (p<0.0001), presence of necrosis (p=0.0004), presence of fibrotic foci (p=0.0005), angiogenesis (p=0.0009), and lymphatic vessel permeation (p=0.018). Multiple logistic regression analysis showed that histological grade and the presence of a fibrotic focus were the only independent prognostic factors and that the presence of occult LN metastases was inversely correlated with early distant relapse. Prospective prognostic studies of occult LN metastases should consider the features of the primary tumour in a multivariate analysis. Copyright

WT1 MUTATION IN MALIGNANT MESOTHELIOMA AND WT1 IMMUNOREACTIVITY IN RELATION TO p53 AND GROWTH FACTOR RECEPTOR EXPRESSION, CELL‐TYPE TRANSITION, AND PROGNOSIS

The Wilms tumour 1 (WT1) gene is believed to contribute to the growth and differentiation of certain tissues, including mesothelium. This study assessed WT1 gene status by mutational screening in 42 malignant mesotheliomas (MMs) and 3 MM cell lines and detected two tumours with identical heterozygous single nucleotide deletions in intron 7, with no apparent consequence for WT1 function. Furthermore, the expression pattern of the WT1 gene was studied in MMs and related lesions using three anti‐WT1 monoclonal antibodies (MAbs). Strong to moderate nuclear immunoreactivity was noted in MM in situ (54/56), cultured mesothelioma cells (4/5), and hyperplastic and normal pleural (non‐neoplastic, NNM) specimens. WT1 immunoreactivity was absent in all primary tumours of lung and in pleural metastases from adenocarcinomas of breast and colon; immunoreactivity was present in pleural metastases from renal carcinomas, melanomas, and papillary carcinomas of the ovary. Expression of the WT1 protein in MM was not correlated with survival. Coordinate expression of the WT1 protein and its putative transcriptional target genes was determined by correlating WT1 immunostaining with epidermal growth factor receptor (EGF‐R) and insulin‐like growth factor 1 receptor (IGF‐1R) expression on MM and NNM; no significant correlation was found, irrespective of p53 expression status. Finally, the putative involvement of WT1 in cell‐type transition was supported by this study, in that epithelial mesothelioma showed the strongest WT1 immunoreactivity while sarcomatous mesothelioma showed the least.

Prophylactic ibuprofen in premature infants: a multicentre, randomised, double-blind, placebo-controlled trial

BACKGROUND Ibuprofen is used for treatment and prevention of patent ductus arteriosus in low-birthweight infants. Its effects on regional circulations differ from those of indometacin. Because prophylactic indometacin reduces the frequency of severe intraventricular haemorrhage and patent ductus arteriosus, we aimed to study the efficacy of early ibuprofen in reducing these outcomes in a double-blind, multicentre trial. METHODS Within 6 h after birth, 415 low-birthweight infants (gestational age <31 weeks) were randomly allocated ibuprofen-lysine (10 mg/kg then two doses of 5 mg/kg after 24 h and 48 h) or placebo intravenously. The primary outcome was occurrence of severe intraventricular haemorrhage; secondary outcomes were occurrence of patent ductus arteriosus and possible adverse effects of ibuprofen. Analysis was by intention to treat. FINDINGS 17 (8%) of 205 infants assigned ibuprofen and 18 (9%) of 210 assigned placebo developed severe intraventricular haemorrhage (relative risk 0.97 [95% CI 0.51-1.82]). In 172 (84%) infants of the ibuprofen group, the ductus was closed on day 3 compared with 126 (60%) of the placebo group (relative risk 1.40 [1.23-1.59]). No important differences in other outcomes or side-effects were noted; however, urine production was significantly lower on day 1 and concentration of creatinine in serum was significantly higher on day 3 after ibuprofen. INTERPRETATION Ibuprofen prophylaxis in preterm infants does not reduce the frequency of intraventricular haemorrhage, but does decrease occurrence of patent ductus arteriosus.