Review: role of cerebral vessels in ischaemic injury of the brain.

This review discusses the pathological changes in the heart and vessels underlying brain ischaemic injury, with a major focus on atherosclerotic disease of the brain induced by lesions of the extracranial cervical and major intracranial arteries and small-vessel disease of the brain. The carotid bifurcation is the primary site for atherosclerotic changes, for which extensive clinical trials and pathological analyses on carotid endarterectomy specimens have been performed. Plaque rupture and erosion give rise to thrombus formation, which leads to brain ischaemic injury. These changes have much in common with atherosclerotic lesions of the subepicardial coronary arteries. Emboli of various types of particles are characteristics of brain ischaemic injury. Thrombi rich in fibrin and red blood cells (red thrombi) that develop in the cardiac chambers are common sources of cerebral emboli. Small-vessel disease of the brain induces fibrinoid necrosis, microaneurysm, fibrohyalinosis, lipohyalinosis and microatheroma, changes commonly associated with hypertension. The acute hypertensive small-vessel changes organize to create segmental arterial disorganization and deep small infarcts when they escape from rupture. Some specific vascular diseases responsible for brain ischaemic injury are briefly reviewed also.

Interaction of androgen-induced autocrine heparin-binding growth factor with fibroblast growth factor receptor on androgen-dependent Shionogi carcinoma 115 cells.

Stimulation of a Shionogi carcinoma 115-derived cultured cell line (SC-3) with androgen resulted in secretion of heparin-binding growth factor. In this study, we analyzed cell-surfaced receptors for growth factors. Binding data of growth factors on intact SC-3 cells revealed the presence of low and high affinity receptors for epidermal growth factor (EGF), insulin, and fibroblast growth factor (FGF). The dissociation constant values were 50 pM and 1.0 nM for EGF, 1.2 nM and 30 nM for insulin, and 34 pM and 7.5 nM for FGF. The numbers of maximal binding sites were 300 and 900/cell for EGF, 2,000 and 14,000/cell for insulin, and 13,000 and 810,000/cell for FGF. To examine the association of androgen-induced growth factor with one of these receptors, the conditioned medium prepared from androgen-stimulated SC-3 cells was fractionated through a heparin-Sepharose column. Growth factor activity adsorbed and eluted by 1 M NaCl from the column was comigrated with the activity inhibiting FGF-receptor association. In addition, basic 125I-FGF was cross-linked, using disuccinimidyl suberate, to the receptor with an apparent molecular weight of 130,000, whose labeling was inhibited when basic FGF, acidic FGF, or highly purified androgen-induced growth factor was present in excess. Furthermore, the highly purified growth factor-, basic FGF- or androgen-induced growth of SC-3 cells was significantly and similarly inhibited by anti-basic FGF antibody IgG. These results indicate that androgen-induced FGF-like factor acts as an autocrine growth factor via the FGF receptor in a process of SC-3 cell proliferation.

Roles of transforming growth factor beta in inhibition of androgen-induced growth of Shionogi carcinoma cells in serum-free medium.

Shionogi carcinoma 115 (SC115) has been accepted for 20 years as an androgen-responsive mouse mammary tumor. In a serum-free culture system we have established [Ham's F-12:Eagle's minimum essential medium (1:1, v/v) containing 0.1% bovine serum albumin], 10(-8) M testosterone markedly stimulates the growth of SC-3 cells (a cloned cell line from a SC115 tumor) via androgen receptor. The testosterone-induced growth of SC-3 cells, which has been shown to be mediated through autocrine fibroblast growth factor (FGF)-like peptide, was almost completely abolished by 1 ng/ml of transforming growth factor beta (TGF-beta). In the present study, mechanisms of the inhibitory effect of TGF-beta on the testosterone-induced growth of SC-3 cells were examined in the serum-free medium. Although the testosterone-induced growth was almost completely inhibited by TGF-beta, basic FGF- or FGF-like peptide (secreted from SC-3 cells by testosterone)-induced growth was only partially inhibited (45%) by TGF-beta. This difference can be explained by the fact that TGF-beta decreased the amount of testosterone-induced FGF-like peptide secreted from SC-3 cells to 18% of control. The TGF-beta-induced inhibition was found to be reversible. Furthermore, no significant effects of the TGF-beta treatment on number or affinity of both androgen and FGF receptors were demonstrated. The present findings show that TGF-beta markedly inhibits testosterone-induced secretion of FGF-like peptide from SC-3 cells and also inhibits growth-stimulatory effects of the secreted factor on SC-3 cells, probably via postreceptor mechanisms.

Inhibitory effect of antibody against basic fibroblast growth factor on androgen- or glucocorticoid-induced growth of Shionogi carcinoma 115 cells in serum-free culture.

Shionogi carcinoma 115 (SC115) has been accepted for 20 years as an androgen-responsive mouse mammary tumor. However, we and others recently found that the growth of SC115 cells is also stimulated by high doses of glucocorticoids. We already reported the following findings. In a serum-free medium [Ham's F-12: Eagle's minimum essential medium (1:1, v/v) containing 0.1% bovine serum albumin], greater than or equal to 10(-9) M testosterone and greater than or equal to 10(-8) M dexamethasone significantly stimulated the growth of SC-3 cells (a cloned cell line from a SC115 tumor) through androgen and glucocorticoid receptors, respectively. In the present study, we have demonstrated that higher concentrations (10(-7)-10(-6) M) of weak androgens such as 4-androstene-3,17-dione or weak glucocorticoids such as corticosterone also significantly stimulate the growth of SC-3 cells and that their relative potency is found to be in parallel with their binding affinity for their receptors, respectively. Furthermore, DNA synthesis of SC-3 cells induced by 0.1 ng/ml basic fibroblast growth factor (FGF), 10(-8) M testosterone, 10(-6) M 4-androstene-3,17-dione, 10(-7) M dexamethasone, or 10(-6) M corticosterone was found to be similarly and significantly inhibited by the addition of basic FGF neutralizing antibody IgG in the present study; approximately 70% inhibition of the basic FGF, androgen, or glucocorticoid effects was attained. We already reported findings which suggest that SC-3 cells produce FGF-like peptide for their testosterone-induced growth. Therefore, the present study presents new additive information to demonstrate that the growth-stimulatory activity of various androgens or possibly glucocorticoids on SC-3 cells is mediated through a FGF-like peptide in an autocrine mechanism.

Proliferation of Shionogi carcinoma 115 cells by glucocorticoid-induced autocrine heparin-binding growth factor(s) in serum-free medium.

Shionogi carcinoma 115 (SC115) has been accepted for 20 years as an androgen-responsive mouse mammary tumor. Recently, the growth of the tumor was also found to be stimulated by pharmacological, but not physiological, doses of glucocorticoid. In a serum-free culture system [Ham's F-12:Eagle's minimal essential medium (1:1, v/v) containing 0.1% bovine serum albumin], we have established that 10(-8) M testosterone, or 10(-6) M dexamethasone significantly stimulates the growth of SC-3 cells (a cloned cell line from a SC115 tumor) via androgen and glucocorticoid receptors, respectively. Recently, we demonstrated that the testosterone-induced growth of SC-3 cells is mediated through autocrine fibroblast growth factor (FGF)-like peptide(s). In the present study, mechanisms of glucocorticoid-induced growth of SC-3 cells were investigated. Serum-free conditioned medium obtained from 10(-6) M dexamethasone-stimulated SC-3 cells was fractionated by heparin-Sepharose affinity chromatography; one sharp peak of growth-stimulatory activity for SC-3 cells, eluted at 1.3 M NaCl, was identified. When the peak fraction was added to serum-free medium, the shape of SC-3 cells changed from an epithelial to a fibroblast-like appearance, similar to that induced with testosterone or basic (b)FGF. Furthermore, the growth-stimulatory activity induced with the peak fraction as well as testosterone or bFGF was markedly inhibited by anti-bFGF antibody immunoglobulin G (75 to 90% inhibition was obtained), and the specific binding of 125I-bFGF on SC-3 cells was significantly inhibited by the peak fraction. These results suggest that the glucocorticoid-induced growth of SC-3 cells is also mediated through FGF-like peptide(s) in an autocrine mechanism, which is very similar to that induced by testosterone, if not identical.

C-reactive protein is an independent predictor of the rate of increase in early carotid atherosclerosis.

BACKGROUND: An elevated plasma concentration of high-sensitivity C-reactive protein (hs-CRP) is a strong predictor of cardiovascular events. However, there have been no longitudinal studies of the relations between development of atherosclerotic lesions and hs-CRP concentrations. Furthermore, it remains unknown whether increased hs-CRP concentrations result in the development of atherosclerosis. METHODS AND RESULTS: The study included 179 outpatients 40 to 79 years of age who were treated at our institute for traditional risk factors for cardiovascular disease. The patients had no evidence of advanced carotid atherosclerosis at the time of baseline examination. Patients underwent repeated ultrasonographic evaluation of the carotid arteries for 35+/-10 months. Blood samples were collected for hs-CRP measurements. Based on focal intima-media thickening >/=1.1 mm representing plaque, plaque number (PN) and plaque score (PS; the sum of all plaque thicknesses) were calculated. The development of atherosclerosis was estimated by the formula Deltavalue/year=(last value-baseline value)/number of follow-up years. Multivariate linear regression analysis revealed that the log-transformed value for hs-CRP concentration was not related to baseline PN or PS but was related to DeltaPN/year and DeltaPS/year (beta=0.29 and 0.30; P<0.001 for both) independently of the effect of traditional risk factors. CONCLUSIONS: During the early stages of carotid atherosclerosis, the hs-CRP concentration is a marker of carotid atherosclerotic activity rather than extent of atherosclerosis.

Reconstitution of peripheral blood lymphocyte subsets in the long-term disease-free survivors of patients with acute myeloblastic leukemia.

The number of long-term survivors of patients with acute myeloblastic leukemia (AML) has increased as a result of the progress of chemotherapy. We examined the recovery of peripheral blood lymphocytes (PBL) subset after chemotherapy to clarify the reconstitution of the immune system in AML. Thirty patients with AML in complete remission (CR) were entered into the study. There were 12 males and 18 females; one M0, six M1, 14 M2, three M3, two M4 and four M5 according to FAB classification. The age ranged from 21 to 78 years (median age, 46 years) and the duration of disease-free survival after completion of chemotherapy ranged from 5 to 122 months (median, 35 months). The chemotherapy was performed according to the protocol designed by the Japan Adult Leukemia Study Group (JALSG). PBL subsets were analyzed by flow cytometry with the use of monoclonal antibodies against CD2, CD3, CD4, CD5, CD8, CD16, CD20, CD45RA, CD56, CD57 and HLA-DR. There was a significant positive relationship between the absolute number of CD4+, CD45RA+ CD4+ cells and the duration of time post-therapy and a significant negative relationship between %CD5+ B, CD56+ cells and the duration of time post-therapy. The appearance of autoantibodies (rheumatoid factor and anti-DNA antibody) tended to increase after 2 years, however, there was no relationship between CD5+ B cells and the frequency of rheumatoid factor. These findings demonstrate that patients in CR have a low number of CD4+ and CD45RA+ CD4+ T cells at an early period after chemotherapy and that each subset recovered to a normal level in 2 years. %CD5+ B and CD56+ cells gradually decreased and returned to their normal level after 4 years. There were high numbers of DR+ T cells and NK cells for a long time, suggesting that activated T cells and NK cells may play a role in the immune surveillance system after chemotherapy.

The expression of tissue factor antigen and activity on the surface of leukemic cells.

Tissue factor activity of intact cell and cell lysate, and the presence of tissue factor antigen on cell surface, were examined in leukemic cells from patients with acute myelogenous leukemia (AML, M1-M5) or acute lymphoblastic leukemia (ALL-L1), and in mononuclear cells from normal donors. Leukemic cells from AML or ALL had significantly more tissue factor activity not only on intact cells but also in cell lysate than mononuclear cells from normal donors (p < 0.001). Tissue factor activities of the intact leukemic cells and lysate from AML patients with DIC were significantly higher than those without DIC (p < 0.001). The relationship between the percent of positive cells for tissue factor and the presence of DIC at the time of diagnosis of acute leukemia was observed. The patients with DIC showed the higher percentage of tissue factor-positive cells than those without (p < 0.01). The development of DIC following chemotherapy was recognized in 2 out of 7 AML-MI patients and 2 out of 4 ALL-L1 patients who had relatively high tissue factor activities of cell lysate. The release of tissue factor from cytoplasm induced by chemotherapy would be another mechanism for the development of DIC. The report suggests the possibility of the prediction for DIC by the flowcytometric assay of tissue factor antigen.

The removal of non-collagen components from newborn calf dermis with magnesium chloride solution.

1. Non-collagenous substances in newborn calf dermis were extracted with solutions of various concentrations of MgCl2. The total protein and hydroxyproline contents in MgCl2 extracts increased with increase in the concentration of MgCl2 in the solutions. In particular, steep increases of their contents were observed at concentrations of MgCl2 from 0.5 to 1.0 M. Total amounts of hydroxyproline in 1.0, 2.0, and 3.0 M MgCl2 extracts were equivalent to 40-50% of the hydroxyproline content in the whole connective tissue. Hexose and hexosamine contents of MgCl2 extracts increased with increase of the MgCl2 concentration. Hexuronic acid was hardly present in the residues after extractions with 0.5, 1.0, 2.0, and 3.0 M MgCl2. 2. Plasma proteins, hyaluronic acid, and dermatan sulfate were extracted at low concentrations of MgCl2. A non-collagenous protein and MgCl2-soluble collagen were extracted with 1.0, 2.0, and 3.0 M MgCl2 solutions. The disperson of collagen fibrils was observed in the residue extracted with 1.0 M MgCl2 solution by electron microscopy; the fibril structure of collagen was disordered by extraction with 2.0 and 3.0 M MgCl2. The results suggest that the dispersion and disorder of collagen fibrils lead to the release of a non-collagenous protein. Furthermore, it is suggested that the removal of hyaluronic acid and dermatan sulfate was not very effective for the solubilization of a large amount of collagen, but was suitable as a pretreatment to the extraction of a non-collagenous protein accompanied by the solubilization of a large amount of collagen. 3. The non-collagenous protein was purified by DEAE-cellulose column chromatography. Polyacrylamide gel electrophoresis of this protein at pH 8.5 showed a single band moving to the cathode. The non-collagenous protein contained 3.7% hexose, 1.8% hexosamine, and no hexuronic acid. This protein is rich in glycine, glutamic acid, and alanine, and contains neither hydroxyproline nor hydroxylysine. Sedimentation analysis showed a single peak with 1.8 S and the molecular weight was approx. 43,000 as determided by SDS polyacrylamide gel electrophoresis.

An essential role of androgen-induced growth factor in glucocorticoid-dependent autocrine loop in Shionogi carcinoma 115 cells.

Androgen-induced growth factor (AIGF) is essential for the androgen-induced autocrine growth of a mouse mammary Shionogi carcinoma cell line (SC-3 cells). Because glucocorticoid and estrogen have been observed to weakly stimulate DNA synthesis in SC-3 cells, the expression of AIGF mRNA after stimulation with various concentrations of androgen, glucocorticoid, or estrogen was examined by Northern blot analysis. Testosterone, dexamethasone, and estradiol-17 beta (E2) induced AIGF mRNA expression, although the maximum AIGF mRNA expression levels induced by dexamethasone or E2 were lower than that by testosterone. Yet, diethylstilbestrol showed no induction, suggesting that the effect of E2 could be mediated through the androgen receptor. The induction levels of AIGF mRNA by each steroid hormone were correlated positively with hormone-induced DNA synthesis. In addition, the DNA synthesis induced by each steroid hormone was almost completely inhibited by AIGF antisense oligonucleotides, indicating that AIGF is an obligatory component in not only the androgen- but also the glucocorticoid-inducible autocrine loop in SC-3 cells.

Growth stimulation by androgens, glucocorticoids or fibroblast growth factors and the blocking of the stimulated growth by antibody against basic fibroblast growth factor in protein-free culture of Shionogi carcinoma 115 cells.

Shionogi carcinoma 115 (SC115) has been accepted for 20 years as an androgen-responsive mouse mammary tumor. We have established an androgen-dependent cloned cell line (SC-3) from a SC115 tumor. In a serum-free medium, testosterone (T) or fibroblast growth factors (FGFs) markedly stimulate the growth of SC-3 cells, and the T-induced growth was shown to be mediated through FGF-like peptide(s) in an autocrine mechanism. Since we used the serum-free culture including 0.1% bovine serum albumin (BSA), a partially serum-containing condition, putative roles of BSA- or serum-borne growth factors in growth stimulation of autocrine production of FGF-like peptide(s) could not be excluded. This paper reports findings performed in a protein-free medium including plating [Ham's F-12:MEM (1:1; v/v)]. In the protein-free culture, the growth of SC-3 cells was significantly stimulated by the addition of greater than or equal to 10(-10) M T (up to 20-fold), greater than or equal to 10(-7) M dexamethasone (Dex; up to 7-fold) or greater than or equal to 1 ng/ml basic (b) or acidic FGF (up to 10-fold); other various growth factors had no such effects. Furthermore, DNA synthesis of SC-3 cells induced by T, Dex or bFGF was similarly and markedly inhibited by bFGF neutralizing antibody IgG. Therefore, the present findings seem to demonstrate that androgens or high levels of glucocorticoids induce the production and secretion of FGF-like peptide(s) from SC-3 cells for their growth even in the absence of additional support by other factors.

A new marrow T cell depletion method using anti-CD6 monoclonal antibody-conjugated magnetic beads and its clinical application for prevention of acute graft-vs.-host disease in allogeneic bone marrow transplantation: results of a phase I-II trial.

We established a simple method of T cell depletion using anti-CD6 monoclonal antibody-conjugated immunomagnetic beads. Preliminary experiments using this method demonstrated that CD3+ T cells could be partially depleted without depleting CD56+ NK cells. A phase I-II clinical study was performed to assess the safety and efficacy of this partial T cell depletion method for the prevention of acute graft-vs.-host disease (GVHD) in 10 leukemia patients at high risk for GVHD (defined as 1) unrelated transplant from MLC-positive or HLA-DRB1 mismatched donor or 2) related transplant from serologically HLA-A, -B, or -DR one-locus mismatched donor). Cyclosporine (CSP) and methotrexate (MTX) were used for additional prophylaxis against GVHD in all cases. Sustained engraftment occurred in 9 of the 10 patients. Although acute GVHD developed in 6 of the 9 evaluable patients, none developed more than grade III severe acute GVHD. Five patients were alive in remission at a median follow-up of 32 months after bone marrow transplantation, and no relapse of leukemia was observed. We conclude from this pilot study that selective T cell depletion with anti-CD6 monoclonal antibody coupled with CSP and MTX posttransplant immunosuppressive therapy is safe. Further analysis of the phase II-III study is needed to confirm the effectiveness of this protocol.

Angle-adjustable sheath for a dual-stage venous cannula.

The dual-stage venous cannula is widely used but can obstruct the surgeon's view and interfere with operative procedures in the aortic root. We designed a new stainless steel sheath for a dual-stage venous cannula that enables the cannula to bend and maintain the appropriate angle for the surgical procedures. We suggest that operative procedures in the aortic root can be performed faster during safety cardiopulmonary bypass by use of a dual-stage venous cannula bent by application of this new sheath.

The effect of reaction temperature for nephelometric assays for rheumatoid factor.

Even using the same assay parameter, reagent and calibrator (N-latex RF kit II), the results of the assay for serum rheumatoid factors (RFs) with the Behring Nephelometer Analyzer (BNA) were higher than those with the Behring Nephelometer II Analyzer (BNII) ([BNII]=0.76 [BNA]-5.7 kIU/l, r=0.997, Sy/x=60.73, n=99). The mean bias (BNA minus BNII)+/-S.D. was 52.7+/-85.5 using the Bland and Altman plot method, and the bias was not constant. The only difference in the assay condition with the two methods was the reaction temperature with the BNA being performed at room temperature (25+/-1 degrees C) and the BNII being performed at 37 degrees C. The ratio of the results with the BNII to the BNA (BNII/BNA) ranged from 0.23 to 1.18. A significant difference was observed in the BNII/BNA ratio in patients with high levels of C-reactive protein (CRP) over 2.0 mg/l (mean BNII/BNA ratio; 0.78) in comparison to patients with normal CRP levels under 2.0 mg/l (mean BNII/BNA ratio; 0.65) (P<0.01). The RF concentrations with the BNA were reduced by addition of urea, which has been used as a mild protein-denaturing agent, and there was a significant correlation between the values calculated as (1-value treated with urea/original value without urea)x100 and the BNII/BNA ratio (r=0.652, P<0.01). These data suggested that the bias between the RF values obtained by the BNA and BNII might be caused by the variation in the reactivity of autoantibodies, which might be decreased in some inflammatory diseases.

Effects of various growth factors on growth of a cloned human esophageal squamous cancer cell line in a protein-free medium.

In order to investigate molecular mechanisms of the growth of human esophageal cancer in relation to growth factors, we have recently established a protein-free culture system [Ham's F-12: Eagle's minimum essential medium (1:1, v/v)] of TE-3-OS cells (a cloned cell line from human esophageal squamous cancer, TE-3). In the present study, we first examined effects of exogenous growth factors on the growth of TE-3-OS cells. The growth of TE-3-OS cells in the protein-free medium was significantly stimulated by insulin and insulin-like growth factor (IGF)-I or IGF-II, and less effectively stimulated by epidermal growth factor (EGF) or transforming growth factor (TGF)-alpha; platelet-derived growth factor, TFG-beta, acidic fibroblast growth factor (FGF) or basic FGF had no effects. TE-3-OS cells contained specific IGF-I binding sites (110,000 sites/cell), with a Kd value of 800 pM. Moreover, the growth induced by IGF-I, IGF-II or insulin was markedly and similarly (70-80%) inhibited by anti-IGF-I receptor antibody IgG. These data suggest that IGF-I, IGF-II and insulin, as well as EGF and TGF-alpha, are important mitogens for human esophageal cancer cells and that effects of IGFs and insulin are mediated predominantly via IGF-I receptors.

Effects of androgen, fibroblast growth factors or other various growth factors on growth of Shionogi carcinoma cells in a protein-free medium.

Shionogi carcinoma 115 (SC115) has been accepted for 20 years as an androgen-responsive mouse mammary tumor. We have recently established an androgen-dependent cloned cell line (SC-3) from a SC115 tumor. We found in the present study that the growth of SC-3 cells can be stimulated by 10(-8) M testosterone (up to 100-fold) even in a protein-free medium beginning from plating [Ham's F-12: Eagle's minimum essential medium (1:1, v/v)]. In the protein-free culture, the proliferation of SC-3 cells was also found to be stimulated by acidic or basic fibroblast growth factor (FGF) alone (up to 50-fold) among various growth factors examined such as FGFs, insulin, insulin-like growth factor (IGF)-I, IGF-II, nerve growth factor, platelet-derived growth factor, epidermal growth factor, transforming growth factor (TGF)-alpha and TGF-beta. The testosterone (10(-8) M)- or FGF (10 ng/ml)-induced growth of SC-3 cells was abolished only by TGF-beta (greater than or equal to 1 ng/ml) among various growth factors examined. We show for the first time in this study an androgen-dependent growth of cancer cells (SC-3) in a protein-free medium. In the protein-free medium, growth of SC-3 cells is also stimulated by FGFs, and the androgen- or FGF-induced growth is inhibited only by TGF-beta.

Effects of prodigiosin 25-C on cultured cell lines: its similarity to monovalent polyether ionophores and vacuolar type H(+)-ATPase inhibitors.

Prodigiosin 25-C inhibited the proliferation of various cultured cell lines more strongly when concanavalin A (Con A) was added to the cultures. The increase in sensitivity was most evident in T lymphoma YAC-1 cells. The combination of prodigiosin 25-C and Con A induced characteristic morphological changes in these cells. In the presence of Con A, monovalent polyether ionophores and vacuolar type H(+)-ATPase inhibitors induced effects similar to those of prodigiosin 25-C on YAC-1 cells. Prodigiosin 25-C had neither K+ionophore activity nor inhibitory effect on vacuolar type H(+)-ATPase. A Golgi mannosidase II inhibitor, swainsonine, inhibited the proliferation of YAC-1 cells only when Con A was added. Prodigiosin 25-C and swainsonine increased Con A binding receptors on the surface of YAC-1 cells. These results suggest that prodigiosin 25-C affects the intracellular transport and/or processing of glycoproteins.

Clinical experiences of surgical repair for mitral regurgitation secondary to papillary muscle rupture complicating acute myocardial infarction.

Mitral regurgitation secondary to ischemic heart disease carries a significant mortality even after emergency open heart surgery. From 1993 to 1997, four patients were operated on for ischemic mitral regurgitation secondary to papillary muscle rupture. These patients were between 58 and 69 years of age and all were in class III or IV of the New York Heart Association Classification. The responsible infarction area was located in the lateral wall in 2 patients, and inferior in others. The interval between the onset of acute myocardial infarction and the appearance of mitral regurgitation was from 1 to 10 days. Three patients had partial rupture (defined as only one or several heads of papillary muscle ruptured), and one had total papillary muscle rupture. Primary mitral plasty was performed in 3 patients, including 1 patient who had undergone patch closure of ventricular septal perforation at the onset of acute myocardial infarction. Mitral plasty combined with coronary artery bypass grafting was performed in 1 patient. Only one case, who had total papillary muscle rupture, required reoperation for recurrence of mitral regurgitation. We suggest that even in the case of ischemic mitral regurgitation, when a papillary muscle rupture is partial, mitral repair is performed because of its potential for improving therapeutic results.

Lymphangioma of the mesentery and small intestine: a case report showing a solid tumor with a cystic component on US and CT.

We encountered a patient with multiple lymphangiomas of the mesentery and small intestine. Ultrasonography and computed tomography showed a mesenteric tumor composed of a solid component with a small cystic part. This unusual appearance made the differential diagnosis between lymphangioma and other intra-abdominal solid tumors difficult.

An electrostatic integrating 222Rn monitor with cellulose nitrate film for environmental monitoring.

This paper describes a new type of electrostatic integrating 222Rn monitor designed for the environmental 222Rn monitoring. The window area of the monitor was selected to make the exchange rate optimal. The collecting electrode was positioned on the basis of calculating the internal electric field. A drying agent, P2O5, was placed in the bottom of the monitor, since the collection efficiency of 218Po+ atoms depends on the humidity of the air. The monitors have been calibrated against known 222Rn exposures. The detection limit is 1.2 Bq m-3 for an exposure time of 2 mo. In a small survey, annual mean 222Rn concentrations between 3.7 and 9.5 Bq m-3 in outdoor air and between 6.4 and 11.9 Bq m-3 in indoor air were measured.