A prospective study on the prognostic significance of urokinase-type plasminogen activator levels in breast cancer tissue

Urokinase-type plasminogen activator (u-PA), which cleaves plasminogen to yield plasmin, is a serine protease of fibrinolysis and is presumed to play a key role in extracellular proteolysis and facilitate the migration of cancer cells. This study was conducted prospectively to evaluate the prognostic significance of u-PA antigen level in breast cancer tissues. u-PA concentrations in the cytosol of 226 breast cancer tissues were determined prospectively by enzyme-linked immunosorbent assay using cytosol fractions prepared for steroid hormone assay. The median follow-up period of the patients was 60 months. Various prognostic factors were evaluated by univariate analysis or multivariate analysis using the Cox proportional-hazards method. Patients with primary breast cancer containing high levels of u-PA had a significantly shorter disease-free survival than patients with low levels of u-PA antigens. In multivariate analysis, a high level of u-PA was an independent risk factor for disease-free survival, being independent of age, axillary node status, and estrogen receptor status. Among the major prognostic factors, a high u-PA antigen level, lymph node involvement, and a positive estrogen receptor status were the most important for predicting relapse-free survival (P=0.044, P<0.0001, P=0.0039). This first prospective study confirmed the prognostic significance of the u-PA antigen level in association with other major prognostic factors. The results of our present study suggest that u-PA in breast cancer tissue might be involved in breast cancer invasion and metastasis. Received: 20 November 1996 / Accepted: 9 June 1997     

A synthetic peptide vaccine involving the product of the pre-S(2) region of hepatitis B virus DNA: protective efficacy in chimpanzees.

The S gene encoding the major surface polypeptide of hepatitis B virus is preceded by the region pre-S(2) with a capacity to code for 55 amino acid residues. In the product of region pre-S(2), the sequence of 19 amino acid residues (amino acids 14-32 from the N terminus) representing an area of high local hydrophilicity is shared by viral strains of subtypes adr, ayw, and ayr; residue 22, phenylalanine, is replaced by leucine in a strain of the other subtype, adw. A synthetic peptide vaccine involving these 19 amino acid residues, when given to two chimpanzees, raised antibodies that bound to viral particles and protected the animals from challenge with 10(6) chimpanzee infectious doses of hepatitis B virus.     

Significance of chymase-dependent angiotensin II formation in the progression of human liver fibrosis

Aim: Angiotensin II may contribute to liver fibrogenesis. In addition to angiotensin-converting enzyme (ACE), chymase, which is expressed by mast cells, is also known to be an angiotensin II-forming enzyme. However, it is unclear which of these two angiotensin II-forming enzymes plays a more important role in liver cirrhosis progression. In the present study, the role of angiotensin II-forming enzymes in the progression of liver cirrhosis was clarified. Methods: A total of 77 patients (16 in F0 stage, 10 in F1 stage, 22 in F2 stage, 12 in F3 stage, and 17 in F4 stage) were classified according to the new Inuyama classification into a non-cirrhosis (F0) group, an early cirrhosis (F1 + F2) group, and a chronic cirrhosis (F3 + F4) group. Results: Both chymase and total angiotensin II-forming activities were significantly higher in chronic cirrhosis patients than in the other two groups. However, there was nodifference among the three groups in ACE activity. On immunohistology, the number of chymase- and angiotensin II-positive cells was significantly higher in the chronic cirrhosis group than in the non-cirrhosis and early cirrhosis groups. There were significant correlations between the number of chymase-positive cells and the number of angiotensin II-positive cells, between the number of chymase-positive cells and the degree of fibrosis, and between the number of angiotensin II-positive cells and the degree of fibrosis. Conclusion: These results suggest that chymase-dependent angiotensin II formation may play an important role in hepatic fibrosis of patients with cirrhosis.     

Cell proliferation at 122 degrees C and isotopically heavy CH4 production by a hyperthermophilic methanogen under high-pressure cultivation

We have developed a technique for cultivation of chemolithoautotrophs under high hydrostatic pressures that is successfully applicable to various types of deep-sea chemolithoautotrophs, including methanogens. It is based on a glass-syringe-sealing liquid medium and gas mixture used in conjunction with a butyl rubber piston and a metallic needle stuck into butyl rubber. By using this technique, growth, survival, and methane production of a newly isolated, hyperthermophilic methanogen Methanopyrus kandleri strain 116 are characterized under high temperatures and hydrostatic pressures. Elevated hydrostatic pressures extend the temperature maximum for possible cell proliferation from 116°C at 0.4 MPa to 122°C at 20 MPa, providing the potential for growth even at 122°C under an in situ high pressure. In addition, piezophilic growth significantly affected stable carbon isotope fractionation of methanogenesis from CO₂. Under conventional growth conditions, the isotope fractionation of methanogenesis by M. kandleri strain 116 was similar to values (−34‰ to−27‰) previously reported for other hydrogenotrophic methanogens. However, under high hydrostatic pressures, the isotope fractionation effect became much smaller (<−12‰), and the kinetic isotope effect at 122°C and 40 MPa was −9.4‰, which is one of the smallest effects ever reported. This observation will shed light on the sources and production mechanisms of deep-sea methane.     

Applicability of ultrasound muscle thickness measurements for predicting fat-free mass in elderly population

Objective: This study aimed to examine the applicability of ultrasound muscle thickness (MT) measurements for predicting whole body fat-free mass (FFM) in elderly individuals. Design and setting: Crosssectional study of 77 healthy elderly individuals. Methods: MTs at nine sites of the body and FFM were determined using B-mode ultrasound and dual-energy x-ray absorptiometry (DXA), respectively, in 44 women and 33 men aged 52 to 78 yrs. Stepwise multiple regression analysis produced two equations for predicting DXA-based FFM with sex (dummy: woman = 0 and man = 1) and either MTs at the anterior and posterior of thigh and lower leg (Eq1) or the product of MT and limb length (MT×LL) at thigh anterior and posterior, lower leg posterior, and upper arm anterior (Eq2) as independent variables. Results: The R2 and SEE for each of the two equations were 0.929 and 2.5 kg for Eq1 and 0.955 and 2.0 kg for Eq2. The estimated FFM from each of Eq1 (44.4 ± 8.9 kg) and Eq2 (44.4 ± 9.0 kg) did not significantly differ from that of the DXA-based FFM (44.4 ± 9.2 kg), without systematic error. However, the absolute value of the difference between the DXA-based and estimated FFM was significantly greater with Eq1 (2.0 ± 1.5 kg) than with Eq2 (1.5 ± 1.3 kg). Conclusion: The current results indicate that ultrasound MT measurement is useful to predict FFM in the elderly, and its accuracy is improved by using the product of MT and limb length as an independent variable.     

Repeated antigen painting and sublingual immunotherapy in mice convert sublingual dendritic cell subsets

The sublingual mucosa (SLM) is utilized as the site for sublingual immunotherapy (SLIT) to induce tolerance against allergens. The contribution of SLM-dendritic cells (SLM-DCs) has not been clarified. The aim of this study was to examine the dynamics and phenotype of SLM-DCs after topical antigen painting and SLIT. SLM-DCs were histologically evaluated after FITC painting. A novel murine Japanese cedar pollinosis (JCP) model was generated and change in SLM-DCs after SLIT was examined. The density of SLM-DCs was clearly lower compared with the buccal mucosa and dorsal surface of the tongue. Topical FITC painting on the SLM induced maximal recruitment of submucosal DCs (smDCs) at 6 h, but most smDCs had vanished at 24 h. Repeated painting on the SLM induced exhaustion and conversion of the smDC phenotype. CD206^highCD11c^low round-type cells with fewer dendrites and less lymph node migration capacity became dominant. In the murine model of JCP, SLIT efficiently inhibited clinical symptoms and allergen-mediated immunological responses. SLIT markedly reduced the number of SLM-DCs, converted to the round-type dominant phenotype and inhibited the activation of regional lymph node DCs. Topical antigen painting on the SLM induced rapid exhaustion and conversion of smDCs. The unique dynamics of SLM-DCs may contribute to tolerance induction in SLIT.     

Histamine and histidine decarboxylase: Immunomodulatory functions and regulatory mechanisms

Histamine is a bioactive monoamine that is synthesized by the enzymatic activity of histidine decarboxylase (HDC) in basophils, mast cells, gastric enterochromaffin‐like (ECL) cells and histaminergic neuronal cells. Upon a series of cellular stimuli, these cells release stored histamine, which elicits allergies, inflammation, and gastric acid secretion and regulates neuronal activity. Recent studies have shown that certain other types of myeloid lineage cells also produce histamine with HDC induction under various pathogenic stimuli. Histamine has been shown to play a series of pathophysiological roles by modulating immune and inflammatory responses in a number of disease conditions, whereas the mechanistic aspects underlying induced HDC expression remain elusive. In the present review, we summarize the current understanding of the regulatory mechanism of Hdc gene expression and the roles played by histamine in physiological contexts as well as pathogenic processes. We also introduce a newly developed histaminergic cell‐monitoring transgenic mouse line (Hdc‐BAC‐GFP) that serves as a valuable experimental tool to identify the source of histamine and dissect upstream regulatory signals.     

s‐Afadin binds more preferentially to the cell adhesion molecules nectins than l‐afadin

l‐Afadin was originally purified from rat brain as an actin filament (F‐actin)‐binding protein that was homologous to the AF‐6 gene product. Concomitantly, s‐afadin that did not show an F‐actin‐binding capability was copurified with l‐afadin. Structurally, s‐afadin lacks the C‐terminal F‐actin‐binding domain but has two short sequences that were not present in l‐afadin. The properties and roles of l‐afadin have intensively been investigated, but those of s‐afadin have poorly been understood. We show here an additional difference in their biochemical properties other than binding to F‐actin between l‐afadin and s‐afadin. Both l‐afadin and s‐afadin bound to nectins, immunoglobulin‐like cell adhesion molecules, whereas s‐afadin more preferentially bound to nectins than l‐afadin. The PDZ domain of l‐afadin and s‐afadin was essential for their binding to nectin‐3. The dilute domain of l‐afadin negatively regulated its binding to nectin‐3, but the deletion of the C‐terminal F‐actin‐binding domain of l‐afadin did not increase the binding of l‐afadin to nectin‐3. These results indicate that the s‐afadin‐specific C‐terminal inserts may be involved in its preference of binding to nectin‐3 and raise the possibility that there are proteins other than nectins that more preferentially bind s‐afadin than l‐afadin.