Microring-ring electrode for manipulation of a single cell

Dielectrophoretic manipulation of a single myeloma cell was carried out using microring-ring electrodes (tip radius, 3-5 microns). When a.c. voltages were applied, the cell nearby the electrode tip was forced to move and trapped at the tip due to dielectrophoretic force induced by locally intense electric field.

[Intravascular ultrasound imaging on the endarterectomized coronary arteries in two patients]

Intravascular ultrasound imaging on the endarterectomized coronary arteries in two patients are reported with a review of the literature. Case 1, a 62-year-old male and case 2, a 64-year-old male underwent endarterectomy of the right coronary artery (#3--#4PD, 4AV) combined with coronary arterial bypass grafting. Coronary arteriography (CAG) and intravascular ultrasound imaging (IVUS) were performed one month after operation. CAG revealed bypass grafts and endarterectomized coronary arteries to be patent together, and IVUS revealed endarterectomized coronary arteries had two layers, outer layer to be hyperechoic and inner layer to be heterogenously echoic in both cases. The histological examination of specimens suggests this heterogenously echoic area represents media, thrombus and irregularly proliferated intima. Therefore, anticoagulant therapy after endarterectomy should be strictly performed.

Temperature-sensitive mouse cell factors for strand-specific initiation of poliovirus RNA synthesis

Two cell lines, TgSVA and TgSVB, were established from the kidneys of transgenic mice carrying the human gene encoding poliovirus receptor. The cells were highly susceptible to poliovirus infection, and a large amount of infectious particles was produced in the infected cells at 37 degrees C. However, the virus yield was greatly reduced at 40 degrees C. This phenomenon was common to all mouse cells tested. To identify the temperature-sensitive step(s) of the virus infection cycle, different steps of the infection cycle were examined for temperature sensitivity. The results strongly suggested that the growth restriction observed at 40 degrees C was due to reduced efficiency of the initiation process of virus-specific RNA synthesis. Furthermore, this restriction appeared to occur only on the synthesis of positive-strand RNA. Virus-specific RNA synthesis in crude replication complexes was not affected by the nonpermissive temperature of 40 degrees C. In vitro uridylylation of VPg seemed to be temperature sensitive only after prolonged incubation at 40 degrees C. These results indicate that a specific host factor(s) is involved in the efficient initiation process of positive-strand RNA synthesis of poliovirus and that the host factor(s) is temperature sensitive in TgSVA and TgSVB cells.

Antimetastatic activity of lipopolysaccharide against a NK-resistant murine fibrosarcoma

An intravenous injection of bacterial lipopolysaccharide (LPS) into mice exerted prominent antimetastatic activities against a NK-resistant weakly immunogenic NFSa fibrosarcoma. The number of visible metastases in the lung was increased by a pretreatment of anti-asialoGM1 (asGM1) antibody or silica, but pretreatment of asGM1 antibody or silica scarcely affected the antimetastatic activities of LPS. The pulmonary retention of radiolabeled tumor cells showed that LPS accelerated the detachment of the tumor cells from the lung, and that this acceleration was not suppressed by anti-asGM1 antibody. Sialic acids of lung endothelial cell surface, essential components of various receptors, was diminished by the i.v. injection of LPS. These results suggested that the antimetastatic effect of LPS against NK-resistant NFSa cells was partly the result of modulations of lung endothelial cell surface.

[Maternal and cord blood thyroid hormones in Graves' disease and fetal states]

Serum concentrations of thyroid hormones (T3, T4, fT3 and fT4), TSH and TRAb in 14 mothers with Graves' disease at 1-4 weeks before delivery were comparably studied with cord blood hormone levels and various fetal states. Twelve mothers were on anti-thyroid drugs and 2 were drug-free, with 8 being euthyroid and 6 being hyperthyroid. Serum concentrations of T3, T4 and fT3 in cord blood were all the same regardless of maternal thyroidal function. Though cord blood TRAb levels correlated with maternal levels, cord fT4 levels were low in those who given antithyroid drugs. TSH levels in cord blood were low in Cesarean section delivery and babies with low birth weight. Birth weight and gestational weeks were both inversely correlated with maternal T4, fT4, fT3 and TRAb concentrations. Thus, maternal hormone levels at late stage of pregnancy in Graves' disease could be useful indices for perinatal risk.

Significance of platelets in an antimetastatic activity of bacterial lipopolysaccharide

Recently we reported an antimetastatic activity of bacterial lipopolysaccharide (LPS) on a NK-cell-resistant murine fibrosarcoma (NFSa). Here we investigate and report the mechanistic significance of platelets in this activity. The number of circulating platelets was reduced to 63% of the control 3 days after an i.v. injection of 1.0 micrograms LPS, and then recovered to the level of control at day 10. Aggregation efficiency of platelets was impaired by LPS. The number of metastatic lung colonies after an i.v. injection of tumor cells was maximally reduced to 2.2% of the control at day 3 and increased in proportion to the recovery of platelet number. Neuraminidase (Ndase), which caused a non-immunological thrombocytopenia, also inhibited lung metastasis when injected prior to an i.v. tumor cell challenge. LPS and Ndase showed an identical pattern against five other syngeneic tumors; these agents inhibited lung metastases of the FSa fibrosarcoma and the SCC VII squamous cell carcinoma but failed to inhibit those of the NR-S1 squamous cell carcinoma, the MMCa#4 mammary adenocarcinoma and the NR-PG parotid gland tumor. All the three cells which were not responsive to any agents possessed a high aggregating activity of platelets while the other three tumors responsive to both agents did not show a detectable level of this activity. Platelet transfusion failed to modify the antimetastatic activity of LPS. These results suggest that platelets play an important role in the antimetastatic activity of LPS, though whether the role is principal or assistant remains to be seen.

Extended total gastrectomy for carcinoma of the cardia

Eighty-five patients with gastric carcinoma developing at or involving the cardia were operated on under a newly established principle to prevent a cancer-positive proximal margin. The choice of operative procedure, standard total gastrectomy or extended total gastrectomy, was determined by the degree of proximal extension of carcinoma as confirmed by preoperative examinations. The cancer-positive rate was decreased in this manner to 1.2% from the 13.8% of the controls operated on before the principle was established. Extended total gastrectomy without sternotomy should be used more frequently than that with sternotomy because of the technical advantages. Survival rates of the 85 patients were 48.3% at three years and 30.4% at five years after the operation, and were not significantly different from the controls. As post-operative survival rate is influenced by factors other than transmural extension of the tumor, this study should prompt us to focus on the problem of the proximal surgical margin in surgery for carcinoma of the gastric cardia.

[Emergency operation for complete papillary muscle rupture after myocardial infarction--a case report of 81-year-old patient]

Mitral regurgitation due to complete rupture of the papillary muscles after myocardial infarction has a very poor prognosis, even if diagnosed and operated on at an early phase. Recently, we performed an emergency operation for mitral regurgitation due to complete papillary muscle rupture after myocardial infarction in an 81-year-old patient. This is probably the oldest case in Japan. Operation revealed complete rupture of the posterior papillary muscle, and valve replacement with a Carpentier-Edwards bioprosthesis was performed.

Molecular mechanisms underlying lymphocyte recirculation. III. Characterization of the LECAM-1 (L-selectin)-dependent adhesion pathway in rats

LECAM-1 (L-selectin) is thought to play an important role in the binding of lymphocytes to high endothelial venules (HEV) of peripheral lymph nodes (LN), which is an essential process in lymphocyte recirculation. Previously we cloned the rat LECAM-1 cDNA. In this study, by using this probe we have sought to characterize a LECAM-1-dependent adhesion pathway in the rat. We have constructed a cDNA for rat LECAM-1-IgG chimera (rLEC-IgG), expressed it, purified the secreted recombinant chimera molecules, and produced mAb reactive with the rat homologue of LECAM-1 by using the chimera molecules. The use of rLEC-IgG revealed that ligands for LECAM-1 are selectively accumulated in high endothelial (HE) cells in LN, the white matter, neurons, cerebellar Purkinje cells, and choroid plexus of the central nervous system and also distal tubules and capillary blood vessels of the kidney. Binding of lymphocytes to LN HEV on frozen sections was blocked by either rLEC-IgG or the anti-rat LECAM-1 mAb. An HEV-derived cell line, Ax, specifically bound to rLEC-IgG fixed on plastic plate. Consistent with the presence of a C-type lectin domain in the ligand-binding region of LECAM-1, the binding was Ca2+ dependent and inhibitable by either the mannose-6-phosphate-rich polysaccharide polyphosphomannan ester or the anti-rat LECAM-1 mAb. These results indicate that the specific ligand for rat LECAM-1 is expressed on the Ax cells. rLEC-IgG precipitated 55-, 65-, 120-, 190-, and > 250-kDa sulfated glycoproteins from LN lysates and 190-, > 250-, and > 500-kDa proteins from Ax cell lysate. The precipitation was Ca2+ dependent and LECAM-1 specific. These results suggest that a carbohydrate structure on HE cells recognized by LECAM-1 is borne possibly on a limited number of cell surface-sulfated glycoproteins. The ligands were also found to be secreted in LN culture supernatants. rLEC-IgG and Ax cells should prove valuable for studying further the role of LECAM-1 in dynamic interactions between lymphocytes and HE cells.

Molecular mechanisms underlying lymphocyte recirculation. III. Characterization of the LECAM-1 (L-selectin)-dependent adhesion pathway in rats

LECAM-1 (L-selectin) is thought to play an important role in the binding of lymphocytes to high endothelial venules (HEV) of peripheral lymph nodes (LN), which is an essential process in lymphocyte recirculation. Previously we cloned the rat LECAM-1 cDNA. In this study, by using this probe we have sought to characterize a LECAM-1-dependent adhesion pathway in the rat. We have constructed a cDNA for rat LECAM-1-IgG chimera (rLEC-IgG), expressed it, purified the secreted recombinant chimera molecules, and produced mAb reactive with the rat homologue of LECAM-1 by using the chimera molecules. The use of rLEC-IgG revealed that ligands for LECAM-1 are selectively accumulated in high endothelial (HE) cells in LN, the white matter, neurons, cerebellar Purkinje cells, and choroid plexus of the central nervous system and also distal tubules and capillary blood vessels of the kidney. Binding of lymphocytes to LN HEV on frozen sections was blocked by either rLEC-IgG or the anti-rat LECAM-1 mAb. An HEV-derived cell line, Ax, specifically bound to rLEC-IgG fixed on plastic plate. Consistent with the presence of a C-type lectin domain in the ligand-binding region of LECAM-1, the binding was Ca2+ dependent and inhibitable by either the mannose-6-phosphate-rich polysaccharide polyphosphomannan ester or the anti-rat LECAM-1 mAb. These results indicate that the specific ligand for rat LECAM-1 is expressed on the Ax cells. rLEC-IgG precipitated 55-, 65-, 120-, 190-, and > 250-kDa sulfated glycoproteins from LN lysates and 190-, > 250-, and > 500-kDa proteins from Ax cell lysate. The precipitation was Ca2+ dependent and LECAM-1 specific. These results suggest that a carbohydrate structure on HE cells recognized by LECAM-1 is borne possibly on a limited number of cell surface-sulfated glycoproteins. The ligands were also found to be secreted in LN culture supernatants. rLEC-IgG and Ax cells should prove valuable for studying further the role of LECAM-1 in dynamic interactions between lymphocytes and HE cells.

Aberrant retrotracheal goiter: report of a case

A case of intrathoracic retrotracheal goiter in a 40-year-old woman is herein described. A computed tomographic scan, magnetic resonance imaging and endoscopical ultrasonography all confirmed the existence of a retrotracheal encapsulated lesion, which was suspected to be aberrant mediastinal goiter. Radioiodine scintigraphy, however, demonstrated little uptake in the mass. A large (7 x 6 x 4 cm), encapsulated adenomatous goiter was then easily removed via a right thoracic approach.

[Lugol staining for esophageal carcinoma and influence of radiotherapy]

For evaluating the endoscopic staining of the esophageal carcinoma with lugol solution, 50 patients who underwent esophagectomy for carcinoma were subjected to this study. Among the 50 patients, 21 were radiated before surgery and 29 were not radiated. The findings of the lugol staining were compared between endoscopic staining and staining on removed specimens. Non-staining area demonstrated by endoscopic procedure almost agreed with that by the procedure on removed specimen in non-radiation group, but both areas of 28.6% cases disagreed in radiation group. On the second step, the extent of non-staining area demonstrated by the procedure of removed specimen was compared with histological extent of carcinoma. The non-staining area on the removed specimen was more extended than histological extent of carcinoma; 10.3% in the non-radiation group and 71.4% in the radiation group. As one of the causes of the large non-corresponding rate in the radiation group, radiation esophagitis was demonstrated. It can be finally concluded that the reliability of endoscopic lugol staining is reduced by preoperative irradiation.

A second gene for the African green monkey poliovirus receptor that has no putative N-glycosylation site in the functional N-terminal immunoglobulin-like domain

Using cDNA of the human poliovirus receptor (PVR) as a probe, two types of cDNA clones of the monkey homologs were isolated from a cDNA library prepared from an African green monkey kidney cell line. Either type of cDNA clone rendered mouse L cells permissive for poliovirus infection. Homologies of the amino acid sequences deduced from these cDNA sequences with that of human PVR were 90.2 and 86.4%, respectively. These two monkey PVRs were found to be encoded in two different loci of the genome. Evolutionary analysis suggested that duplication of the PVR gene in the monkey genome had occurred after the species differentiation between humans and monkeys. The NH2-terminal immunoglobulin-like domain, domain 1, of the second monkey PVR, which lacks a putative N-glycosylation site, mediated poliovirus infection. In addition, a human PVR mutant without N-glycosylation sites in domain 1 also promoted viral infection. These results suggest that domain 1 of the monkey receptor also harbors the binding site for poliovirus and that sugar moieties possibly attached to this domain of human PVR are dispensable for the virus-receptor interaction.

[A case of an unusual type of coarctation of the aorta terminating in the complete obstruction]

A 19 year-old girl with an unusual type of coarctation of the aorta terminating in complete obstruction is presented. At the age of 5 years, she was diagnosed by aortography to have coarctation of the aorta of type IV C according to Edward's classification. No surgical treatment was performed at that time because her growth was good and she didn't have hypertension. During the follow-up period, marked hypertension developed, and she was readmitted. The aortogram revealed a bicuspid aortic valve and total obstruction of the descending thoracic aorta at the site where coarctation was noticed previously. The abdominal aorta distal from the obstruction site was filled through rich collateral circulation. As these angiographic interval changes are very rare, we discussed the genesis of obstruction and operative indication by reviewing the literature.

MRL/MP-lpr/lpr mouse as a model of immune-induced sensorineural hearing loss

Hearing acuity and inner ear disorders of MRL/lpr mice, bred for the study of autoimmune disease, were examined in comparison to those of BALB/c mice. The auditory brain stem response threshold of 20-week-old MRL/lpr mice was significantly higher than that of BALB/c mice of the same age (p < .01). The pathologic changes of 20-week-old MRL/lpr mice were characterized by the degeneration of intermediate cells, widened intercellular spaces, and immunoglobulin G deposition on the basement membrane of strial blood vessels as well as in the basal infolding of strial marginal cells, which were absent in BALB/c mice. That there were no other evident pathologic findings in the cochlea or middle ear suggests that these changes in the stria vascularis seemed to be responsible for the sensorineural hearing loss of this mouse. The MRL/lpr mouse was thought to be a good experimental model to study the spontaneous sensorineural hearing loss caused by an immune reaction.

Nonlinear survival curves for cells of solid tumors after large doses of fast neutrons and gamma rays

We have previously proposed that survival curves for cells of murine NFSa fibrosarcomas after exposure to fast neutrons might demonstrate curvature when the neutron doses reach a level high enough to cure the fibrosarcomas. We report here that this is the case. Murine NFSa fibrosarcomas growing in the hind legs of syngeneic mice were exposed to either gamma rays or fast neutrons. The tumors were removed and retransplanted into fresh recipients to obtain 50% tumor cell doses, from which the dose-cell survival relationship was constructed. Survival curves showed continuous bending down to 10(-7), and were well fitted using the linear-quadratic model. The alpha and beta values for neutrons were larger than those for gamma rays. When the surviving fractions at experimental TCD50 doses were calculated using these values, comparable figures were obtained for neutrons and gamma rays. The RBEs for neutrons were comparable for the TCD50 and TD50 assays. Neutron RBE was independent of dose within a range of 5-28 Gy. The capacity of the tumors to repair the damage caused by large doses of neutrons was identical to that for small doses of neutrons, indicating that cells retained the capacity to repair neutron damage irrespective of the size of the dose.

[Treatment of liver metastases from gastric cancer]

Nine patients with liver metastases from gastric cancer were treated in our department since 1986. Hepatectomy was performed in 3 cases and hepatic arterial infusion chemotherapy was performed in 6 cases. In 3 patients in whom hepatectomy was performed, the extent of liver metastases showed 2 H1 and 1 H2. One has survived for 20 months, but the other 2 died after 5 and 7 months, respectively. In 6 patients in whom hepatic arterial infusion chemotherapy was performed, the extent of liver metastases was H3. These patients were treated with 5-FU.EPIR.MMC (3 cases), CDDP.MMC (1 case), MMC only (1 case) and 5-FU.ADM.MMC.CDDP (1 case). This treatment revealed a 50% response rate (CR 1, PR 2). The patient with CR has survived for 6 years and 2 patients with PR died after 8 and 12 months. The patient with CR showed high AFP level (55, 480 ng/ml), and 2 patients with PR showed high AFP level (24, 327 ng/ml) or high CEA level (3,903 ng/ml). The prognosis of hepatectomy for liver metastases from gastric cancer was not so good. Hepatic arterial infusion chemotherapy seemed to be a useful treatment for liver metastases from gastric cancer.

[Health effects of non-occupational exposure to asbestos]

Mesothelioma has occurred in a relative large number not only among miners but also among non-occupationally exposed persons living in the northwestern region of Cape State of South Africa, where crocidolite is mined and transported. The long-term residents of Thetford Mines in Quebec Province, Canada, who have never engaged in mining and milling of chrysolite have not shown an excess mortality of respiratory diseases. Tremolite in soil is responsible for mesothelioma among residents of certain geologic regions such as Cyprus, Corcica, northwestern Greece and Turkey. An increased prevalence of malignant mesothelioma has been reported among residents of three Turkish villages due to exposure to erionite fibers having a high carcinogenic potency. Mesothelioma has infrequently developed in wives who were exposed while washing the work clothes of their husbands contaminated with asbestos, especially amphiboles. The levels of airborne asbestos in public buildings and schools in the U.S.A. and England having walls and ceilings constructed with asbestos containing materials are approximately 1/100 of the permissible concentration of 0.2 f/cm3. The estimated risk from asbestos exposure in schools and buildings is lower than the level of other risks in other society. During the work of removing asbestos from buildings the asbestos concentration is remarkably increased and this persists for many weeks thereafter. The level of asbestos fibers released from brake linings of motor vehicles is higher along roads with heavy traffic, at intersections, and near toll booths than elsewhere. The concentration of asbestos fibers released from motor vehicles is generally low and not of the level to induce mesothelioma.

[Experience of intravascular ultrasound imaging on a stenosed saphenous vein graft]

A 73-year-old man underwent coronary-artery bypass grafting surgery on #4 PD and #7 with saphenous vein graft. Coronary arteriography and graft visualization performed on the 28th postoperative day revealed 75% concentric stenosis in the middle of the #4 PD graft. Before and after PTCA to the graft, examination by intravascular ultrasound imaging was performed and revealed that the stenosis was caused by fibrotic atheroma or thrombus. Intravascular ultrasound imaging appears to be useful in the field of cardiac surgery. It can be used in the follow-up of bypass grafts and also the detection of the entry site in dissecting aortic aneurysms. A brief review of the literature is given.

Infective endocarditis causing acute myocardial infarction by compression of the proximal left coronary artery due to a mycotic aneurysm of the sinus of Valsalva

An extremely unusual case of myocardial infarction associated with infective endocarditis (IE) is described. A 38-year old male with a high fever was transferred to our hospital for further treatment of IE. Two-dimensional echocardiogram showed a large mycotic aneurysm of the sinus of Valsalva in contact with neighbouring structures. The patient had a rapid recovery within several days after administration of antibiotic agents. However, he then developed abrupt onset of severe precordial pain. From the echocardiogram images and biochemical evaluation he was diagnosed as having an acute subendocardial infarction. Serial echocardiograms revealed expansion of the aneurysm, extending from the myocardium of the anterolateral free wall to the lower margin of the proximal left coronary artery. The cause of acute myocardial infarction was thought to be incomplete occlusion of the coronary artery through compression by the enlarging mycotic aneurysm of the sinus of Valsalva. Urgent surgery confirmed compression of the left coronary artery by the large mycotic aneurysm as the cause of acute myocardial infarction.

Active components of intestinal bacteria for abdominal irradiation-induced inhibition of lung metastases

We have previously reported that abdominal irradiation of mice inhibited lung metastases of a weakly immunogenic fibrosarcoma, and that transmigration after the irradiation of Enterobacter cloacae into mesenteric lymph nodes coincided with this phenomenon. In this paper, we show that Escherichia coli as well as E. cloacae reduce the number of metastatic lung colonies when these bacteria were intravenously injected into mice prior to the tumour cell challenge. The inhibition was caused not only by the administration of living bacteria but also by that of killed bacteria. Bacterial lipopolysaccharide (LPS), a component of membrane, replaced at least in part the effect of whole bacteria. Transfer of spleen cells from LPS-treated mice into intact recipients prominently inhibited metastatic development in the recipient mice. 'Cross transfer' between LPS high responders and LPS low responders suggested an indirect activity of transferred spleen cells. The antimetastatic activity of LPS depended on the tumour cell type; metastasis of fibrosarcomas was extensively inhibited by LPS irrespective of tumour immunogenicity while that of adenocarcinomas was only slightly inhibited. These results suggest that non-immunological mechanisms are involved in the antimetastatic activity of LPS.

[Operative management of the calcified patent ductus arteriosus in the elderly]

Two cases of the calcified PDA were experienced in subjects aged more than 50 years. A 63-year-old woman was successfully operated upon. A Fogarty's balloon catheter was wedged into the PDA through the ductus after a pulmonary arteriotomy under cardiopulmonary (CP) bypass. A 57-year-old woman was safely operated. PDA was repaired under partial CP bypass with Bio-pump. Postoperative courses of these cases were uneventful. Brief review of surgical treatment for PDA was given.