Working while unwell: Workplace impairment in people with severe asthma.

BACKGROUND: Severe asthma affects quality of life; however, its impact on workplace productivity is poorly understood. OBJECTIVE: To compare workplace productivity-absenteeism and presenteeism-and impairment in daily activities in severe and non-severe asthma over time and identify characteristics associated with presenteeism in severe asthma. METHODS: The Severe Asthma Web-based Database is an ongoing observational registry from Australia, New Zealand and Singapore. At April 2017, 434 patients with severe asthma and 102 with non-severe asthma were enrolled (18-88 years; 59% female). Participants provided comprehensive clinical and questionnaire data at baseline and were followed-up every 6 months for 24 months. Absenteeism (percentage of time not at work), presenteeism (self-reported impairment at work) and impairment in daily activities outside work due to health problems in the last week were calculated. RESULTS: At baseline, 61.4% of participants with severe asthma and 66.2% with non-severe asthma under 65 years were employed. At younger ages (30-50 years), fewer severe asthma participants were employed (69% vs 100%). Presenteeism and impairment in daily activity were more frequently reported in severe asthma and in participants with poorer asthma control, poorer lung function and more past-year exacerbations (P < .01). Over time, deteriorating asthma control was associated with increasing presenteeism. Although absenteeism was not different between severe and non-severe asthma, worse asthma control was associated with absenteeism (P < .001). In participants with severe asthma, presenteeism was reported more frequently in those with poorer asthma control, poorer asthma-related quality of life and symptoms of depression or anxiety (P < .01). CONCLUSION AND CLINICAL RELEVANCE: Severe asthma was associated with impairment at work and outside the workplace. Improving asthma control and mental health may be important targets for optimizing workplace productivity in severe asthma. Presenteeism and absenteeism may represent key metrics for assessing intervention efficacy in people with severe asthma of working age.

Integrated multidisciplinary community service for chronic obstructive pulmonary disease reduces hospitalisations.

BACKGROUND: Hospitalisations for chronic obstructive pulmonary disease (COPD) exacerbation affect patient outcomes and healthcare costs. The long-term impact of an integrated COPD disease-management approach on hospitalisation remains controversial. AIM: The aim of this study was to evaluate whether a multidisciplinary community service reduces respiratory hospitalisations for COPD patients. METHODS: A total of 346 patients was followed for a mean duration of 27.3 months. The number of admissions, total bed days for respiratory (COPD exacerbation or pneumonia) or general medical causes and length of stay (LOS) per respiratory admission was compared before and after referral with the service. A secondary multivariate analysis examined which clinical parameters best predict benefit from such service. RESULTS: The total respiratory admission and hospital bed days after referral were reduced by 31% (288 vs 417, P < 0.001) and 40.4% (1637 vs 2746, P < 0.0001) respectively, compared with the equivalent duration prior. The average LOS for each respiratory admission was also significantly reduced after referral (6.61 vs 5.70, P = 0.02). Overall, 55% patients experienced a reduction in admission frequency and hospital days. The impact on admission frequency and hospital days was the greatest in those with an at least moderate disease (GOLD ≥2, odds ratio (OR): 3.2, 95% confidence interval (CI): 1.2, 8.9; P = 0.019) and those who completed pulmonary rehabilitation (PR) (OR: 1.7, 95% CI: 1.1, 2.8; P = 0.04). In contrast, general medical admissions increased, one-third attributable to a cardiovascular cause both before and after referral. CONCLUSIONS: The implementation of COPD multidisciplinary community service was associated with reduced respiratory hospitalisations in the long term. Patients with moderate or severe disease and who are able to complete PR are much more likely to benefit.

Pharmacogenetics of ß2 adrenergic receptor gene polymorphisms, long-acting ß-agonists and asthma.

Adrenergic ß2 receptor (ADRß2) agonists are widely used in asthma. Approximately 10% of patients have severe, poorly controlled disease despite extensive use of ADRß2 agonists. Variations in responses to ADRß2 agonists can, in part, be attributed to genetic variation, with 49 different polymorphisms having been identified for the ADRß2 gene. Although clear associations exist between ADRß2 gene polymorphisms, such as +46G>A, and patient response, the importance of these polymorphisms remains controversial. Patient selection, the number of polymorphisms analysed, differences in the type/dose of ADRß2 agonist, use of inhaled corticosteroids and population sizes have all varied. Most studies were limited to mild or moderate asthmatics using ADRß2 agonists sparingly. It is difficult to extrapolate from these studies to individual patients who have severe asthma, use a variety of ADRß2 agonists and do so frequently. The extent to which ADRß2 gene polymorphisms are relevant to asthma management needs further review, both clinically and at the molecular level. In vitro studies have helped to define the functional changes induced by specific ADRß2 gene polymorphisms, including 3'-untranslated region poly-C repeat. The resulting ADRß2 gene haplotypes (rather than genotypes), the interactions among ADRß2 gene haplotypes and variations in the chemistry of different agonists deserve more detailed assessment. Responses to ADRß2 agonists depend on effective downstream signalling following ADRß2 activation and also on receptor regulation. Studies on other regulators of ADRß2 receptor signalling and trafficking may be equally important in understanding the functional role of ADRß2 gene polymorphisms. The role of ADRß2 gene polymorphisms in the pathogenesis and management of severe asthma cannot be clearly defined until more specific and targeted research studies are performed.

Tumor necrosis factor mRNA localized to Paneth cells of normal murine intestinal epithelium by in situ hybridization.

Paneth cells in normal murine small intestine contain TNF mRNA that is readily detectable by in situ hybridization, unlike resident macrophages in lamina propria, which are negative. Northern blot analysis of whole tissue shows the presence of mRNA that has the same electrophoretic mobility as TNF mRNA from activated macrophages. A low level of TNF bioactivity, but no immunoreactivity, was detected in normal small intestine, and TNF production in resting Paneth cells appears to be post-transcriptionally controlled. Typical leukocyte surface membrane markers were not found on Paneth cells, but were expressed by the surrounding lamina propria macrophages. Paneth cells are thus epithelial cells with leukocyte-like secretory potential that may be important in intestinal physiology and pathology.

Species heterogeneity in macrophage expression of the CD4 antigen.

The CD4 antigen is expressed on T cells of all mammalian species examined and appears to play an important role in the response of T cells to antigen. In humans, the molecule acts as a receptor for the AIDS virus. Previous studies have demonstrated that M phi in the rat and human also express the CD4 antigen, which is indistinguishable from that on T cells. In this paper we demonstrate by FACS analysis, Northern blot hybridization, and immunoperoxidase labeling that, in striking contrast to the rat and human, mouse M phi do not express the CD4 (L3T4) antigen. This species heterogeneity indicates that T cells and M phi regulate CD4 antigen expression independently and that CD4 may not be essential for M phi function.

Prevalence of pulmonary arterial hypertension in an Australian scleroderma population: screening allows for earlier diagnosis.

BACKGROUND: We sought to determine the prevalence of pulmonary complications and especially pulmonary arterial hypertension (PAH) in an Australian scleroderma population. METHODS: Between July 2005 and June 2007, physicians in Western Australia were asked to refer patients with scleroderma specifically for pulmonary hypertension screening. All patients were assessed for PAH and other respiratory conditions using echocardiography, lung function testing and clinical assessments. Right heart catheterization was carried out in patients with evidence of increased right ventricular systolic pressure. RESULTS: Of the 184 patients analysed, 44 had possible PAH on echocardiography. Right heart catheterization confirmed the diagnosis in 24 (13%). Diffuse interstitial lung disease was found in 32 patients representing a point prevalence of 17.4%. The severity of PAH at diagnosis varied according to whether the patients were referred for screening (group A) or for diagnostic (group B) purposes. The 6-min-walk test distance and median pulmonary vascular resistance were significantly worse in group B versus group A (324 vs 402 m; P= 0.02 and 884 dynes/s per cm(-5) vs 486 dynes/s per cm(-5); P < 0.01, respectively). CONCLUSION: Screening may result in earlier diagnosis of PAH with, in general more mild disease. This is important, given that early treatment for PAH while patients are less symptomatic is associated with improved exercise tolerance and pulmonary haemodynamics: indices indicative of disease progression and clinical worsening.

Frequent microsatellite instability and mismatch repair gene mutations in young Chinese patients with colorectal cancer.

BACKGROUND: The incidence of colorectal cancer in persons under 46 years of age is substantially higher in Hong Kong than in Scotland and many other countries. Consequently, we examined whether there is a hereditary predisposition for colorectal cancer in this Southern Chinese population. METHODS: We investigated the incidence of microsatellite instability (MSI) at 10 DNA sites in 117 colorectal cancer specimens from Chinese patients of various ages. Those tumors with new alleles at 40% or more of the sites investigated were identified as highly unstable MSI (MSI-H). In young patients, we also searched for germline mutations in three mismatch repair genes (hMSH2, hMLH1, and hMSH6). RESULTS: The incidence of MSI-H varied statistically significantly with age, being observed in more than 60% of those younger than age 31 years at diagnosis and in fewer than 15% of those age 46 years or older. In 15 patients (<46 years old) whose colorectal cancers showed MSI-H, eight possessed germline mutations in either hMSH2 or hMLH1. When mutations in hMSH6 were included, more than 80% of Chinese colorectal cancer patients younger than 31 years had germline mutations in mismatch repair genes. We found a novel germline missense mutation in hMSH6 in a 29-year-old man whose tumor showed no MSI. Two patients had a 4-base-pair insertion in exon 10 causing a truncated protein; this insertion is a common polymorphism with a population allele frequency in Chinese of 5.6%. CONCLUSIONS: Our results indicate that germline mutations in mismatch repair genes contribute substantially to the pathogenesis and high incidence of colorectal cancer in young Hong Kong Chinese. However, because young Chinese and Caucasians show similar proportions of colorectal cancers with MSI-H, despite the higher incidence in the former, additional factors may underlie the high susceptibility of young Chinese to colorectal cancer.

hMLH1 promoter methylation and lack of hMLH1 expression in sporadic gastric carcinomas with high-frequency microsatellite instability.

Mutation of DNA mismatch repair genes has rarely been documented in sporadic gastric carcinoma with microsatellite instability (MSI). In sporadic colorectal carcinoma, hMLH1 promoter methylation associated with protein loss is found in the majority of high-frequency MSI cases. We investigated a series of 35 sporadic gastric carcinomas stratified into high-frequency MSI (MSI-H), low-frequency MSI (MSI-L) and microsatellite stable (MSS) groups and found that hypermethylation of the CpG island in the hMLH1 promoter region was present in 100% of MSI-H sporadic gastric carcinomas. In 90% of cases, there was an associated complete loss of hMLH1 protein, as detected by immunohistochemistry, and a markedly lowered hMLH1 mRNA level. This loss of hMLH1 protein occurred in the MSI-H invasive tumor but not in the adjacent carcinoma-in situ or dysplastic components that were MSS. The MSI-L and MSS forms of gastric carcinoma all showed predominantly unmethylated hMLH1 promoter, positive hMLH1 protein and high hMLH1 mRNA level. On the other hand, hMSH2 protein was expressed in all of the tumors irrespective of the MSI status. Our results suggest that high-frequency MSI in sporadic gastric cancer is mostly due to epigenetic inactivation of hMLH1 in association with promoter methylation, and the loss of hMLH1 protein is a significant event in the development of invasive tumor.

A novel germline 1.8-kb deletion of hMLH1 mimicking alternative splicing: a founder mutation in the Chinese population.

We have previously reported that there is a high incidence of microsatellite instability (MSI) and germline mismatch repair gene mutation in colorectal cancer arising from young Hong Kong Chinese. Most of the germline mutations involve hMSH2, which is different from the mutation spectrum in the Western population. It is well known that alternative splicing is common in hMLH1, which complicates RNA based mutation detection methods. In contrast, large deletions in hMLH1, commonly observed in some ethnic groups, tend to escape detection by exon-by-exon direct DNA sequencing. Here we report the detection of a novel germline 1.8 kb deletion involving exon 11 of hMLH1 in a local hereditary non-polyposis colorectal cancer family. This mutation generates a mRNA transcript with deletion of exons 10-11, which is indistinguishable from one of the most common and predominant hMLH1 splice variants. A diagnostic test based on PCR of the breakpoint region led to the identification of an additional young colorectal cancer patient with this mutation. Haplotype analysis suggests that they may share a common ancestral mutation. Our results caution investigators in the interpretation of alternative splicing and have important implications for the design of hMLH1 mutation detection strategy in the Chinese population.

p53 gene mutation spectrum in hepatocellular carcinomas in Hong Kong Chinese.

To examine the significance of mutation of the p53 tumour suppressor gene in the development of human hepatocellular carcinoma in a high-prevalence area for hepatitis B viral infection but a low-exposure area for aflatoxin B1, the spectrum of p53 gene mutations was examined in 21 tumour samples from Hong Kong Chinese patients, all of whom were HBsAg positive. DNA sequencing covering exons 5 to 9 of the p53 gene and Hae III restriction enzyme digestion for preliminary assessment of mutation at codon 249 were performed. Immunohistochemical staining with anti-p53 monoclonal antibodies was done on both tumour and nontumour liver tissues. Six tumours (28.6%) showed a p53 mutation and all were point mutations. Of the six point mutations, two (9.5%) were at codon 249 and both were G to T transversions (AGG-->ATG and AGG-->AGT transversions). The remaining point mutations were transversions scattered at codon 172 (exon 5), 214 (exon 6), 273 (exon 8) and 330 (exon 9). Mutated p53 protein was detected in five of these six cases with demonstrable point mutations by DNA sequencing, in contrast to none detected in all of the 15 cases without demonstrable point mutations. The presence of p53 mutations, including those at codon 249, did not show a significant association with tumour size, sex, age, tumour invasiveness in terms of liver invasion, microsatellites and venous permeation, cirrhosis and encapsulation, but tumours with low cellular differentiation tended to have a higher incidence (71%) of point mutations than those with high cellular differentiation (8%). In conclusion, both the overall p53 mutation rate and that a codon 249 in HCC in Hong Kong Chinese are lower than those reported in tumours from China and sub-Saharan Africa. The low mutation rate at codon 249 is compatible with a low aflatoxin exposure. A special type of p53 mutation has not been found to be associated with hepatitis B viral infection. Mutations of p53 gene tends to occur in tumours with low cellular differentiation, suggesting a late occurrence in the event of tumour progression.

Chromosomal instability and p53 inactivation are required for genesis of glioblastoma but not for colorectal cancer in patients with germline mismatch repair gene mutation.

We have previously reported high-frequency microsatellite instability (MSI-H) and germ-line mismatch repair gene mutation in patients with unusually young onset of high-grade glioma. Some of these patients developed metachronous MSI-H colorectal cancer and conformed to the diagnosis of Turcot's syndrome. Frameshift mutation of TGFbetaRII was present in all the colorectal carcinomas but not in brain tumours. We further characterized the genetic pathways of tumour evolution in these metachronous gliomas and colorectal carcinomas. All MSI-H glioblastomas had inactivation of both alleles of the p53 gene and showed over-expression of the p53 protein while none of the colorectal carcinomas had p53 mutation or protein over-expression. Flow cytometry and comparative genomic hybridization revealed that all glioblastomas were chromosomal unstable with aneuploid DNA content, and with a variable number of chromosomal arm aberrations. In contrast, the colorectal carcinomas had diploid or near-diploid DNA content with few chromosomal arm aberrations. The pattern of chromosomal aberrations in the two organs was different. Loss of 9p was consistently observed in all glioblastomas but not in colorectal carcinomas. Epidermal growth factor receptor amplification was absent in all glioblastomas and colorectal carcinomas. Our results suggest that both the frequency of p53 mutation and its effects differ greatly in the two organs. Following loss of mismatch repair function, p53 inactivation and chromosomal instability are not necessary for development of colorectal carcinoma, but are required for genesis of glioblastoma. Oncogene (2000) 19, 4079 - 4083.

Amino acid sequence studies of human C4b-binding protein: N-terminal sequence analysis and alignment of the fragments produced by limited proteolysis with chymotrypsin and the peptides produced by cyanogen bromide treatment.

Treatment of human C4b-binding protein (C4BP) with cyanogen bromide gave five major peptides and limited proteolysis with chymotrypsin yielded two fragments. The yields, apparent mol. wts and N-terminal amino acid sequences of these peptides and fragments indicates that in dissociating conditions, after reduction of disulphide bonds, C4BP is composed of only one type of polypeptide chain of approx. 70,000 mol. wt. The amino acid sequence data obtained, which accounts for over 55% of the total sequence, allows an alignment of the cyanogen bromide peptides. In addition the amino acid sequence data indicates that the 70,000-dalton polypeptide chain of C4BP contains nine internal homology regions, each 60 amino acids long, which would account for 540 of the expected 600 amino acids in C4BP. Similar internal homology regions are found within the Ba region of factor B [Morley and Campbell, EMBO J. 3, 153-157 (1984)] and it is of interest that the regions found in C4BP are homologous to those found in Ba.

Clonal Epstein-Barr virus in lymphoepithelioma-like carcinoma of the lung.

Lymphoepithelioma of the nasopharynx is an undifferentiated carcinoma with a prominent lymphoid infiltrate. A consistent association with Epstein-Barr virus (EBV) has been demonstrated over the years by a variety of methods. More recently, undifferentiated carcinomas with a similar morphology have been described in other anatomical locations, often of foregut origin. However, for lymphoepithelioma-like carcinoma, the association with EBV has been more tenuous, especially in Western countries. Interestingly, these tumors have shown a geographic distribution similar to nasopharyngeal lymphoepithelioma, with relatively high frequency of EBV positive cases in Asian patients. We report five cases of lymphoepithelioma-like carcinoma arising in the lung. In situ hybridization revealed the presence of EBV in all cases with localization to the epithelial cells only. Southern-blot analysis from two cases revealed the presence of clonal episomal EBV in the tumor tissue. These findings further support the hypothesis that EBV is also associated with lymphoepithelioma-like lung carcinomas and suggest that EBV infection has preceded the clonal expansion of the tumor.

In situ detection of Epstein-Barr virus in gastric and colorectal adenocarcinomas.

The association of Epstein-Barr virus (EBV) with lymphoepithelioma-like carcinoma in the nasopharynx, which is common in Chinese from the southern region, is well established. Recently, EBV has also been found to be associated with lymphoepithelioma-like carcinomas (LELCs) and carcinomas with prominent lymphoid infiltrates in the stomach. We investigated for the presence of EBV in 74 cases of gastric adenocarcinoma and 36 cases of colorectal adenocarcinoma from Chinese patients by in situ hybridization (ISH) using an antisense EBER probe. In seven cases (9.5%) of gastric carcinoma, EBER was highly expressed in the adenocarcinoma cells and metastatic tumor cells in regional lymph nodes. In all these cases, the normal gastric epithelium was EBV negative. None of the colorectal carcinomas showed a positive signal. Isolated positive lymphoid cells were frequently found in both tumors. Of the seven positive cases, only one was LELC, and the others were conventional adenocarcinomas of the intestinal type. Five showed expression of the viral RNA in all tumor cells as well as the surrounding dysplastic epithelium. Interestingly, the sixth case showed distinct negative islands of dysplastic glands adjacent to strongly positive dysplastic glands and invasive carcinoma cells. This pattern of positivity, together with negative normal gastric epithelium and positive metastatic tumor, suggested that EBV infection occurred in the dysplastic phase and that an apparent growth advantage was conferred by the EBV infection.

Expression of vascular endothelial growth factor and its receptors in pilocytic astrocytoma.

Vascular endothelial growth factor (VEGF), a potent angiogenic and vascular permeability factor, is important in the angiogenesis of glioblastoma. A major difference between pilocytic astrocytoma, a grade I tumor, and the grade II fibrillary astrocytoma is the vascular proliferation, highly vascularized stroma, and great propensity for cyst formation in the former. In order to explore factors regulating such angiogenesis and cyst formation in pilocytic astrocytoma, we examined expression of VEGF and its receptors (KDR and Flt-1) using in situ hybridization. In all 14 cases a high level of VEGF transcripts could be demonstrated. These were found in specific regions, namely, in the tumor cyst wall, in areas of hyaline cystic degeneration, in stellate reticulated astrocytes around microcysts in the biphasic compact and loose areas, and in tumor cells with degenerative pleomorphic multicoated nuclei. KDR and Flt-1 were expressed in the tumor vasculature, with particularly high levels seen in coiled young proliferating vessels, especially those in the cyst wall. Given the known angiogenic and vascular permeability activities of VEGF, we propose that VEGF plays an important role in molding the characteristic morphologic features of this tumor, namely, the formation of cysts, microcystic pattern, hyaline cystic degeneration, hyaline vessels, and vascular proliferation. Mechanisms that block the VEGF pathway could constitute a potential therapeutic strategy for the treatment of this tumor.

Epstein-Barr virus is present in a wide histological spectrum of sinonasal carcinomas.

Nasopharyngeal carcinomas, a common occurrence in Southern Chinese people, shows a strong association with Epstein-Barr virus (EBV); in the same population, sinonasal carcinomas are distinctly rare. Although most nasopharyngeal carcinomas are lymphoepitheliomas, sinonasal carcinomas have a wide morphological spectrum. We studied the clinicopathological features and EBV status of 29 sinonasal carcinomas from Hong Kong Chinese patients. By in situ hybridization using antisense Epstein-Barr virus early RNA (EBER) probe, seven tumors were shown to be strongly positive for the EBV RNA. They displayed a wide morphological spectrum, including one cylindric cell carcinoma, one intestinal type adenocarcinoma, four nonkeratinizing squamous cell carcinomas, and one undifferentiated carcinoma. All were from elderly subjects (mean age, 67), including six men and one woman. Three of these seven patients had complete remission after radiotherapy with a median follow-up period of 29 months. In two cases, EBV latent membrane protein-1 was expressed. Detection of the virus in a number of histological subtypes, including cylindric cell carcinoma and adenocarcinoma, suggests that EBV may play a role in the pathogenesis of a diverse spectrum of carcinomas.

Expression of vascular endothelial growth factor and its receptors in the anaplastic progression of astrocytoma, oligodendroglioma, and ependymoma.

Vascular endothelial growth factor (VEGF) is a hypoxia-inducible angiogenic factor, which is known to be upregulated in most cases of glioblastoma multiforme (GBM). The expression of VEGF and its receptors in ependymomas, oligodendrogliomas, and particularly the expression during anaplastic progression of these three types of gliomas has not been studied extensively. Fifty-six gliomas, consisting of 10 ependymomas, 12 oligodendrogliomas, 3 anaplastic oligodendrogliomas, 6 astrocytomas grade II, 5 anaplastic astrocytomas, and 20 glioblastoma multiformes, were investigated for VEGF and receptor expression using in situ hybridization (ISH) and reverse transcription polymerase chain reaction (RT-PCR). Results showed that VEGF was moderately to strongly expressed in 8 of 10 ependymomas and in all anaplastic oligodendrogliomas and glioblastoma multiforme cases. These tumors displayed similar degrees of extensive necrosis and vascular proliferation, with VEGF expression consistently seen in tumor cells around necrotic areas. The VEGF expression, although present at a lower level, also was shown in 4 of 12 oligodendrogliomas, in 3 of 6 astrocytomas grade II, and in 2 of 5 anaplastic astrocytomas, with a regional rather than diffuse pattern of positive result. The findings from the in situ hybridization study correlated with the expression index, as determined by reverse transcription polymerase chain reaction. Expression of VEGF was correlated significantly with vascular proliferation (p < 10(-5)) and necrosis (p < 10(-5)), as well as with microvessel density (p = 0.002, rs = 0.41). The VEGF receptors, kinase domain region (KDR) and Fms-like-tyrosine kinase (Flt-1), also were upregulated in the tumor vasculature of glioblastoma multiforme, anaplastic oligodendrogliomas, and ependymomas with necrosis, whereas the astrocytomas grade II, anaplastic astrocytomas, and oligodendroglioma tumors tended to express a weak to nondetectable signal. Anaplastic progression in all three types of gliomas is heralded by the occurrence of small zones of VEGF-expressing cells and early vascular proliferation, followed by an accelerated phase of angiogenesis closely associated with VEGF induction around areas of necrosis and with the expression of VEGF receptors in the tumor vasculature.

Tissue-specific expression pattern of vascular endothelial growth factor isoforms in the malignant transformation of lung and colon.

Angiogenesis, a prerequisite for tumor growth and progression, results from a shift in the equilibrium between angiogenic factors and angiogenic inhibitors. Vascular endothelial growth factor (VEGF) has been identified as one of the most important factors mediating angiogenesis in physiological and pathological conditions. Through alternative splicing, four isoforms of VEGF are formed, consisting of 206, 189, 165, and 121 amino acids, respectively. VEGF206 and VEGF189 differ from VEGF165 and VEGF121 in their bioavailability, with the longer forms being matrix-bound and the shorter forms freely diffusible. To investigate the relative importance of the VEGF isoforms in neoplastic transformation, we studied the pattern of splice variant expression by reverse transcription polymerase chain reaction (RT-PCR) in 18 lung and 11 colonic carcinomas and their corresponding normal tissues, respectively. The findings showed a significant upregulation of VEGF in both carcinomas, with VEGF165 and VEGF121 being the predominant forms; VEGF189 was significantly expressed in normal lung but not colon; and VEGF206 was not detected in any specimen. The findings indicate that during malignant progression, an angiogenic switch favoring the shorter diffusible isoforms is likely to confer on the tumor a growth advantage. From the differential expression of VEGF isoforms in normal lung and colonic tissues, different functional roles of the splice variants is suggested. In particular, VEGF189 may be important for the maintenance of the vascular integrity of the lung.

Expression of vascular endothelial growth factor in von Hippel-Lindau syndrome-associated papillary cystadenoma of the epididymis.

Vascular endothelial growth factor (VEGF) is a hypoxia inducible angiogenic and vascular permeability factor. Although VEGF expression in glioblastoma is induced by hypoxia, its expression in renal cell carcinoma and hemangioblastoma is thought to be related to mutation of the von Hippel-Lindau (VHL) gene. It is not certain whether other lesions in VHL syndrome are associated with an elevated VEGF level. We report a VHL syndrome patient with multiple hemangioblastomas and bilateral epididymal clear cell papillary cystadenomas. In situ hybridization revealed high levels of VEGF mRNA in the clear cells of the epididymal tumor and the stromal cells of the hemangioblastoma. This lends support to the notion that upregulation of VEGF is caused by loss of the wild-type VHL protein. We postulate that the elevated VEGF levels may account for the cyst formation and vascularized stroma present in these VHL-associated tumors.

Transformation of diffuse large B-cell lymphoma into pre-B acute lymphoblastic leukemia: clinicopathologic features and clonal relationship.

A patient with fibrosing alveolitis developed a diffuse large B-cell (DLBC) lymphoma that expressed CD20 and CD30. After an initial response, the lymphoma relapsed and was salvaged with further chemotherapy. After another remission of 3 years, a pre-B-cell acute lymphoblastic leukemia (ALL), which expressed CD10, CD19, CD22, CD79a, CD34 and terminal deoxyribonucleotidyl transferase, developed and led to death. Molecular analysis of the immunoglobulin heavy-chain gene showed that the initial lymphoma and its relapse were clonally related. At leukemic relapse, 2 clones related to the initial and relapsed lymphoma clones were present. DLBC lymphomas arise from post-follicle center B cells, whereas ALL arises from pregerminal B cells. Therefore, a direct transformation of DLBC lymphoma to ALL appears unlikely. The overall features suggest instead separate lymphoma and leukemic evolution from a common mutated B-cell precursor rather than transformation of DLBC lymphoma to ALL.