Gamma-carboxylated isoforms of recombinant human protein S with different biologic properties

Human protein S (HPS), a regulator of hemostasis, is a vitamin K- dependent plasma protein with potential clinical utility. We have obtained high-level expression of the cDNA for HPS in two mammalian cell lines. Both cell lines secreted single chain recombinant HPS (rHPS) in serum-free medium as determined by Western blot analysis. The ability of the rHPS from both cell lines to act as a cofactor for human protein C (HPC) was determined; the rHPS secreted from the human 293 cell line had an activity six times that of the rHPS from the AV12-664 Syrian hamster cell line. Furthermore, the relative specific cofactor activity of rHPS from the 293 cell line was actually 2.5-fold higher than that of single-chain human plasma-derived HPS. Essentially all of the rHPS secreted from the 293 cell line exhibited a calcium-dependent elution profile on anion exchange chromatography, whereas only 25% to 35% of the hamster cell-derived rHPS exhibited this profile. However, the calcium-eluted rHPS from the AV12 cell line had a high specific cofactor activity, equivalent to that of the 293-derived rHPS. A NaCl- elutable rHPS fraction (calcium nondependent) was isolated from the recombinant AV12-664 cell line, further purified, and found to have reduced activity, only 40% that of the calcium-dependent rHPS. The only observable difference in the calcium-dependent and nondependent rHPS molecules was in the content of gamma-carboxyglutamic acid (Gla); the calcium-dependent material contained approximately 10 mol Gla/mol protein whereas the calcium-nondependent material contained only approximately 8 mol Gla/mol of protein. In addition, the calcium- nondependent rHPS had reduced ability to interact with phospholipid vesicles as evidenced by an eightfold increase in the apparent kd. Our data demonstrate the isolation of rHPS with high specific activity, and show that a reduction in as few as two Gla residues dramatically decreases its functional cofactor activity for HPC, due to a reduction in ability to interact with the phospholipid bilayer.     

Hyaluronidases and hyaluronan synthases expression is inversely correlated with malignancy in lung/bronchial pre-neoplastic and neoplastic lesions, affecting prognosis

We collected a series of 136 lung/bronchial and 56 matched lung parenchyma tissue samples from patients who underwent lung/bronchial biopsies and presented invasive carcinoma after lung surgery. The lung/bronchial samples included basal cell hyperplasia, squamous metaplasia, moderate dysplasia, adenomatous hyperplasia, severe dysplasia, squamous cell carcinoma and adenocarcinoma. Matched lung parenchyma tissue samples included 25 squamous cell carcinomas and 31 adenocarcinomas. Immunohistochemistry was performed to analyze for the distribution of hyaluronidase (Hyal)-1 and −3, and hyaluronan synthases (HAS)-1, −2, and −3. Hyal-1 showed significantly higher expression in basal cell hyperplasia than in moderate dysplasia (P=0.01), atypical adenomatous hyperplasia (P=0.0001), or severe dysplasia (P=0.03). Lower expression of Hyal-3 was found in atypical adenomatous hyperplasia than in basal cell hyperplasia (P=0.01) or moderate dysplasia (P=0.02). HAS-2 was significantly higher in severe dysplasia (P=0.002) and in squamous metaplasia (P=0.04) compared with basal cell hyperplasia. HAS-3 was significantly expressed in basal cell hyperplasia compared with atypical adenomatous hyperplasia (P=0.05) and severe dysplasia (P=0.02). Lower expression of HAS-3 was found in severe dysplasia compared with squamous metaplasia (P=0.01) and moderate dysplasia (P=0.01). Epithelial Hyal-1 and −3 and HAS-1, −2, and −3 expressions were significantly higher in pre-neoplastic lesions than in neoplastic lesions. Comparative Cox multivariate analysis controlled by N stage and histologic tumor type showed that patients with high HAS-3 expression in pre-neoplastic cells obtained by lung/bronchial biopsy presented a significantly higher risk of death (HR=1.19; P=0.04). We concluded that localization of Hyal and HAS in lung/bronchial pre-neoplastic and neoplastic lesions was inversely related to malignancy, which implied that visualizing these factors could be a useful diagnostic procedure for suspected lung cancer. Finalizing this conclusion will require a wider study in a randomized and prospective trial.     

Characterization of the potentiation effect of activin on human erythroid colony formation in vitro

Activin, also named FSH-releasing protein, was previously shown to induce hemoglobin accumulation in K562 cells and potentiate the proliferation and differentiation of CFU-E in human bone marrow cultures. Present studies indicate that the potentiation effect of activin is lineage specific. In addition to CFU-E, activin caused an increase in the colony formation of BFU-E from either bone marrow or peripheral blood. It had little effect on the colony formation of CFU- GM and the mixed colonies from CFU-GEMM. In serum-depleted culture, the effect of activin was shown to be dose-dependent with doses effective at picomolar concentrations. The potentiation effect of activin was exerted indirectly through mediation of both monocytes and T lymphocytes. Activin was also found to increase specifically the proportion of DNA-synthesizing erythroid progenitors from both bone marrow and peripheral blood. It had little effect on DNA synthesis in CFU-GM and in mitogen-stimulated lymphocytes. Addition of the monocytes or T lymphocytes to their respective depleted subpopulations of mononuclear cells reconstituted the enhancing effect of activin on the colony formation and DNA synthesis of erythroid progenitors. These results strongly suggest a specific role of activin in potentiating the proliferation and differentiation of erythroid progenitors in vitro.     

Haemophagocytic syndrome associated with hepatitis‐B virus infection responding to etoposide

Haemophagocytic syndrome (HPS) secondary to viral infections usually has a variable course and can be life‐threatening. We report a 53‐year‐old male patient who presented with fever, hepatosplenomegaly and pancytopenia. He had deranged liver function, abnormal clotting and markedly elevated serum ferritin. Bone marrow biopsy showed prominent haemophagocytosis. The patient was investigated thoroughly and found to have evidence of chronic hepatitis B‐virus (HBV) infection by serological tests and liver biopsy. Other conditions associated with HPS such as lymphoma, malignancy and other viral or bacterial infections were not present. The patient did not respond to steroids, intravenous immunoglobulins or cyclosporin but responded to etoposide and became apyrexial. He also became HBV negative on lamivudine. The patient died of infection later on but there was no evidence of recurrence of HPS. To the best of our knowledge this is the first case report of HPS associated with isolated HBV infection.     

Detection of the Philadelphia chromosome in acute lymphoblastic leukemia by pulsed-field gel electrophoresis

The Philadelphia (Ph1) chromosome is an acquired abnormality in the malignant cells of 10% to 25% of patients with acute lymphoblastic leukemia (ALL). Unlike chronic myelogenous leukemia (CML), where the molecular detection of the Ph1 chromosome is relatively straightforward using conventional Southern hybridization analysis, the detection of the Ph1 chromosome in ALL is complicated by the existence of several molecular subtypes, and the fact that translocation breakpoints are dispersed over a large genomic area. To circumvent these difficulties, we investigated pulsed-field gel electrophoresis (PFGE) to determine if this method could be used directly on clinical samples to detect the Ph1 chromosome in ALL. We report that, in a study of seven patients with Ph1-positive ALL, we could easily detect the Ph1 using only a single PFGE analysis, regardless of the Ph1 subtype, and we could confirm that the translocations occur either within or very near the BCR gene in all seven. We conclude that PFGE is a useful technique for the detection of the Ph1 in ALL, which ultimately may find wide applicability in the detection of other chromosomal abnormalities in other malignancies.     

Clinical and echocardiographic survey of the Ehlers-Danlos syndrome

Cardiac abnormalities such as mitral valve prolapse (MVP) are reported to be common features of the Ehlers Danlos syndrome (EDS), and it has been suggested that the majority of patients with type IV EDS will have cardiac involvement and vascular aneurysms. However, the evidence for valve lesions is inconsistent and often based on early clinical studies using mainly M-mode echo. We studied 33 patients (six male, 27 female; median age 35 yr) with EDS (30 type I, II or III, three type IV) and 30 age- and sex-matched controls. The study assessed skin stretch and joint hypermobility using Beighton and Contompasis scores. Echocardiographic examination included standard two-dimensional views from the parasternal and apical windows, and measurement of the aorta at four sites (annulus, sinotubular junction, arch and abdominal aorta). Echocardiographic abnormalities were found in four patients (12.1%) (one atrial septal aneurysm, one tricuspid prolapse, two MVP) and two controls (6.7%). MVP was found in 6.1% of EDS patients and 7% of controls. Seven patients had previously been diagnosed as having MVP; only two were shown to have true MVP using current criteria. None of those with type IV EDS had any echocardiographic abnormality. No patients with EDS had mean aortic dimensions outside the normal range at any of the points tested. Cardiac symptoms were more frequent amongst the patients than controls (atypical chest pain 48%, P = 0.0001; palpitation 39%, P = 0.001; exertional dyspnoea 30%). A wide range of rheumatological complaints were reported (current arthralgia 75%; recent back pain 72%, P = 0.005; recurrent dislocation 72%). Contrary to earlier published observations, we have not found an increased incidence of cardiac abnormalities in EDS. This syndrome may be relatively more benign, from the cardiac point of view, than was previously thought.      

Significance of a mitral regurgitation systolic murmur complicating a first acute myocardial infarction in the coronary care unit -- assessment by colour Doppler flow imaging

To determine the prevalence and significance of a systolic mitralmurmur heard after a first acute myocardial infarction (MI),we studied 186 consecutive patients in the coronary care unit(CCU) during a one-year period. Fifteen patients had a murmuras a result of mitral regurgitation (MR) (prevalence 8%) documentedby colour Doppler flow imaging. It was heard before the thirdday of hospitalization in 10 (67%) patients, and on the thirdday itself in the remainder. The severity of MR was graded semi-quantitatively:moderate in 12 (80%) patients, and mild, moderate to severeand severe in three respectivety. The direction of the MR jet,determined by colour flow imaging, improved the informationobtained by two-dimensional echocardiography (2D echo) thatcould only diagnose mitral leaflet abnormality in seven (47%)patients. in 10 of 15 (67%) patients, the 2D echo ejection fractionwas 40% and in eight (53%) the wall motion score obtained byanalysing 11 left ventricular (LV) segments was $$$8. Two (13%)patients died in tile CCU, four (27%) had LV failure, one anginaand eight (53%) remained asymptomaric in the hospital. Of 171patients without a systolic murmur, 22 (13%) had LV failure,13 (8%) angina and 25 (15%) died during the in-hospital stay(P-NS for these complications between patients with and withoutMR murmur). During a follow-up of 12–24 months, one MRpatient died, and seven (47%) remained asymptomatic. We conclude that the prevalence of MR systolic murmurs in acuteMI patients is low. The LV function and the prognosis of a majorityof these patients is rather good.