The B allele with a 5·8 kb deletion in intron 1 of the ABO gene is the major allele in Japanese individuals with Bm and A1 Bm phenotypes

B_m and A₁ B_m phenotypes are the most frequent ABO variants in the Japanese population. The B antigen on B_m red blood cells is only detectable by adsorption and elution tests, and plasma B-transferase activity is usually detected at half or less levels compared with that of common B. Recently, a B allele lacking an erythroid cell-specific transcription enhancer in intron 1 of the ABO gene was identified from individuals with B_m and A₁ B_m phenotypes, which could explain the unique serologic properties of B_m . In the Japanese Red Cross Society, eight Blood Centers tested blood samples from donors throughout Japan and collected blood samples from 888 B_m and 415 A₁ B_m individuals. DNA analysis revealed that 1300 of 1303 (99·77%) individuals had the B allele with a 5·8 kb deletion (c.28 + 5110_10889del), which included the enhancer element.

Minimally cultured bone marrow mesenchymal stem cells ameliorate fibrotic lung injury

Clinical use of bone marrow mesenchymal stem cells (BMMSCs) holds great promise for regenerative medicine in intractable lung diseases, such as lung fibrosis or acute respiratory distress syndrome. However, a severe obstacle to the clinical application of BMMSC transplantation is the time-consuming, laborious processes required for cell culture. In order to evaluate the clinical applicability of BMMSC transplantation, we tested whether engraftment of minimally cultured BMMSCs ameliorates progressive fibrotic lung injury. Differences between murine BMMSCs cultured for 2 h (2-h adherent BMMSCs) and conventionally (9-day) cultured BMMSCs were examined in vitro. The effects of grafting either type of BMMSCs on fibrotic lung injury were then assessed by transfer experiments in a murine bleomycin-induced lung fibrosis model, in which donor cells were administered 3 days after challenge. 2-h adherent BMMSCs were smaller, less granular, possessed higher proliferative capacity and expressed higher levels of several stem cell markers and chemokine receptors than 9-day cultured BMMSCs, but lower type I procollagen, alpha-smooth muscle actin, tumour necrosis factor-beta and oncogenic transcription factor c-Myc, suggesting that they may be advantageous for cell-based therapy compared with 9-day cultured BMMSCs. Grafting 2-h adherent BMMSCs ameliorated inflammatory and fibrotic lung disorders, and reduced mortality equally well or better than 9-day cultured BMMSCs. Minimally cultured BMMSCs can substitute for conventionally cultured BMMSCs and will be a promising cell source for the treatment of acute fibrotic lung injury.

Helicobacter pylori-induced atrophic gastritis progressing to gastric cancer exhibits sonic hedgehog loss and aberrant CDX2 expression

BACKGROUND

The loss of sonic hedgehog is an early change that occurs in the mucosa prior to neoplastic transformation and correlates with the type of intestinal metaplasia. Aberrant expression of CDX has also been shown to correlate with the development of intestinal metaplasia.

AIM

To examine CDX2 expression in the non-cancerous mucosa of patients with gastric cancer and compared it to CDX2 expression in controls with intestinal metaplasia.

METHODS

Sixty patients who had undergone endoscopic mucosal resection for early gastric cancer and 60 gender- and age-matched controls were studied. Two specimens each were obtained from the greater and lesser curves of the corpus and from the greater curve of the antrum. Expression of CDX2 and sonic hedgehog were evaluated by immunostaining.

RESULTS

Gastric cancer was associated with a higher frequency of incomplete intestinal metaplasia (OR = 8.3; 95%CI, 3.7-18.9, P < 0.001). CDX2 negatively correlated with sonic hedgehog expression, however, multivariate analysis revealed that CDX2 correlated with the intestinal metaplasia scores. Sonic hedgehog indices were lower and CDX2 staining in the corpus lesser curve was higher in the cancer group than in the controls. Sonic hedgehog indices in the corpus decreased and CDX2 indices in both areas increased in patients in the ascending order of those without intestinal metaplasia, those with complete intestinal metaplasia and those with incomplete intestinal metaplasia (P < 0.001).

CONCLUSIONS

Loss of sonic hedgehog expression and aberrant expression of CDX2 correlates with the type of intestinal metaplasia and may play a role in carcinogenesis.

Expression of laminin 5 basement membrane components in invading and recurring adenoid cystic carcinoma of the head and neck

OBJECTIVE

Adenoid cystic carcinoma (ACC) of the head and neck grows slowly with structural differentiation, however, this tumor nevertheless also shows a highly invasive potential and a high recurrence rate. Extracellular matrices have been suggested to play an important role in the differentiation and growth of ACC. The aim of this study is to understand the roles of laminin 5 basement membrane (BM) components, including collagen IV and laminin gamma2 for the high degree of invasiveness and the recurrence of ACC.

METHODS

Collagen IV and laminin gamma2 were immunohistochemically localized in tissue sections from nine patients with ACCs.

RESULTS

Cribriform structures with pseudocysts were preserved in small invading tumor nests, and the expression of both of collagen IV and laminin gamma2 was observed in the inner border of the pseudocysts and the surrounding area of the tumor nests. In areas of perineural invasion, the BM components continued to be expressed around the long tumor nests. Recurrent tumors consisted of multiple small nests with a few tumor cell layers, and the expression of the BM components was observed on both the inside of the inner tumor cells and the outside of the outer tumor cells, which was an obviously different appearance from that of the primary tumor.

CONCLUSION

ACC appears to possibly grow and invade using the laminin 5 BM matrices while also preserving their differentiated architecture. The laminin 5 BM matrices might play an important role not only in the differentiation and growth, but also in the invasion and recurrence of ACC of the head and neck.

Diffuse expression of laminin gamma2 chain in disseminating and infiltrating cancer cells indicates a highly malignant state in advanced tongue cancer

The expression of laminin (LN)gamma2 chain in the primary lesions of 20 patients with advanced tongue cancer was analyzed. Positive expressions of LNgamma2 were noted in all of the primary tissue specimens, however, the expression patterns clearly differed according to the mode of growth and invasion of cancer cells. In tumor nests where cancer cells preserved cell-cell adhesiveness and showed polar differentiation, LNgamma2 was expressed only in the peripheral cells of the tumor nests; peripheral expression. On the other hands when cancer cells diminished their cell-cell adhesiveness and strongly infiltrated through stroma, almost all of the cancer cells diffusely expressed LNgamma2; diffuse expression. The peripheral expression of LNgamma2 were noted in 13 patients and the diffuse expressions were noted in 7 patients. The rates of positive cervical metastases according to the expression type were 7/13 for the peripheral expression and 7/7 for the diffuse expression (p = 0.02). The diseases specific 3-year survival rates for the patients with the peripheral expression and the diffuse expression were 68% and 14%, respectively (p = 0.02). The diffuse expression of LNgamma2 in the disseminating and infiltrating cancer cells might indicate a highly malignant state in advanced tongue cancer. Therefore, a more intensive treatment modality would be necessary for the patients with advanced tongue cancer showing the diffuse LNgamma2 expression.

[Laminin gamma2 chain expression in squamous cell carcinomas of the tongue and its clinical relevance]

Laminin gamma2 chain (LNgamma2) expression and its clinical relevance were examined in squamous cell carcinomas of the tongue. When tumor cells were attached to each other and showed expansive growth, LNgamma2 was expressed only in the peripheral cells of the tumor nests (peripheral expression). In contrast, when tumor cells showed infiltrative growth diminishing cell-cell adhesion, LNgamma2 expression was diffusely observed in almost all of the cells (diffuse expression). Patients with caricinoma cells of the primary lesions showing peripheral LNgamma2 expression were classified as the peripheral expression type, whereas patients with carcinoma cells showing diffuse LNgamma2 expression at least in part of the invasive fronts were classified as the diffuse expression type. Among 30 patients with tongue carcinomas of more than stage II, 19 patients were the peripheral expression type and 11 patients were the diffuse expression type. The 3-year disease-specific survival rates for the peripheral type and diffuse type were 64% and 34%, respectively. LNgamma2 may play an important role in growth and invasion of tongue carcinomas. In particular, it seems likely that the diffuse LNgamma2 expression in carcinoma cells has a significant relevance to the malignant characteristics of infiltrative carcinoma cells. In addition, LNgamma2 expression may be a useful prognostic factor for the patients with carcinomas of the tongue.

Hypoacidity combined with high gastric juice nitrite induced by Helicobacter pylori infection is associated with gastric cancer

BACKGROUND

In patients with Helicobacter pylori infection, the concentration of nitrite in gastric juice is elevated. The degree of elevation correlates with that of inflammation and H. pylori density.

AIM

The aim of this study was to examine hypoacidity and high nitrite levels related to H. pylori infection in patients with gastric cancer.

METHODS

We studied 88 patients with more than one history of endoscopic mucosal resection (EMR) for early gastric cancer and 88 age-matched controls. Concentration of nitrite in gastric juice was measured by Griess reaction, and serum pepsinogen levels were measured by RIA.

RESULTS

Multiple malignant lesions were found in 20 of the 88 patients. Serum gastrin, gastric juice pH and nitrite levels in patients with gastric cancer were significantly higher and pepsinogen I and pepsinogen I/II significantly lower than in control subjects. Pepsinogen I level and I/II ratio were lower and gastric juice pH was higher in the protruded-type group than in the depressed-type group. Pepsinogen I and pepsinogen I/II were lower and gastric juice pH was higher in multiple than in single cases.

CONCLUSIONS

Hypoacidity combined with high gastric juice nitrite induced by H. pylori infection is associated with the intestinal type of gastric cancer, especially protruded lesions.

Helicobacter pylori infection and increased nitrite synthesis in the stomach. Inflammation and atrophy connections

BACKGROUND

We have previously shown that the nitrite content in the gastric juice of Helicobacter pylori-positive patients is significantly higher than that of H. pylori-negative patients and it decreases after eradication of H. pylori.

AIM

To examine the relationship between the nitric oxide synthesis in the gastric lumen and histological findings.

METHODS

Eighty-five middle aged Japanese patients were studied. Four specimens, each obtained from the greater and lesser curvature of antrum and gastric body were processed for the determination of histopathological scores using the updated Sydney System. Gastric juice was collected endoscopically to determine the concentration of nitrite using a modified Griess reaction.

RESULTS

There was a significant positive correlation between the nitrite and the pH levels (r = 0.81, P < 0.001) and between the pH levels and the histopathological scores in the corpus. The gastric juice pH and concentration of the nitrite increased in patients with histological diagnosis of normal, antral-predominant gastritis, pangastritis and corpus-predominant gastritis in due order.

CONCLUSIONS

H. pylori infection effects nitric oxide synthesis in the gastric lumen which is mainly connected with hypoacidity. The gastric juice pH is one of the useful markers for corpus dominant gastritis and probably for high-risk group of gastric cancer.

Radiation-induced apoptosis in the scid mouse spleen after low dose-rate irradiation

PURPOSE

To elucidate the process of radioadaptation, the role of DNA-PK activity was examined using the scid mouse defective in DNA-PKcs.

MATERIALS AND METHODS

The induction of apoptosis in the spleens of the C.B-17 Icr scid mouse and the parental mouse was studied after chronic irradiation with gamma-rays at 1.5 Gy (0.001 Gy min(-1) for 25 h) followed by challenge irradiation with X-rays at 3.0 Gy (1.0 Gy min(-1) for 3 min).

RESULTS

When the wild-type mouse was previously exposed to chronic irradiation (1.5 Gy) at a low dose-rate (0.001 Gy min(-1)), apoptosis induced by acute irradiation (3.0 Gy, 1.0 Gy min(-1)) was significantly suppressed, especially in the splenic white pulp. There was no change by acute irradiation after chronic irradiation in the scid mouse, although an effect was detected in the spleen after acute irradiation alone.

CONCLUSIONS

These data suggest that DNA-PK activity might play a major role in the radioadaptive response following pre-irradiation at a low dose-rate.

Effects of pH and metal ions on antioxidative activities of catechins

The Effects of pH on antioxidative activities of catechol, pyrogallol, and four catechins, and effects of metal ions (Al3+, Ca2+, Cd2+, Co2+, Cr3+, Cu2+, Fe2+, Fe3+, K+, Mg2+, Mn2+, Na+, and Zn2+) on antioxidative activities of (-)-epigallocatechin gallate (EGCG) were studied by an oxygen electrode method. The antioxidative activities of catechins were high and constant at pH 6-12, but decreased in acidic and strong alkaline solutions. Copper(II) ion the most strongly increased the antioxidative activity of EGCG among these metal ions examined, but iron(II) ion largely inhibited the antioxidative activity of EGCG. These effects are discussed considering the formation of metal complexes with catechins and the change in oxidation potentials.

High plasma cardiac natriuretic peptides associated with enhanced cyclic guanosine monophosphate production in preascitic cirrhosis

BACKGROUND/AIMS

The initial abnormalities of renal sodium handling in cirrhosis remain unclear. The aim of this study was to characterize sodium metabolism in preascitic cirrhosis.

METHODS

Ten patients with preascitic cirrhosis and ten controls were studied. All subjects ate a diet providing 120 mmol sodium during an equilibration period lasting 5 days and the study day. On the study day, after remaining in bed, plasma levels of atrial natriuretic peptide, brain natriuretic peptide, renin activity, aldosterone, noradrenaline, and cyclic guanosine monophosphate were measured at 7 am. Thereafter, they were instructed to maintain an upright posture until dinner and the measurements were repeated at 9 am and 6 pm. After having dinner, all subjects were asked to remain in bed and the measurements were repeated at 11 pm. To measure renal sodium and cyclic guanosine monophosphate excretion, 24-h urine collections were performed, starting from 7 pm on the day before the experimental day.

RESULTS

Plasma levels of atrial natriuretic peptide, brain natriuretic peptide and cyclic guanosine monophosphate in patients with preascitic cirrhosis were significantly elevated compared with those in controls at every sampling time (p=0.03 or less, p= 0.04 or less, and p=0.01 or less). In contrast, plasma renin activities at every sampling time were significantly lower in patients than in controls (p= 0.04 or less). Plasma aldosterone and noradrenaline levels were not significantly different at every sampling time in the two groups. No significant differences in daily renal sodium excretion were found. However, urinary cyclic guanosine monophosphate excretion was significantly higher in patients than in controls (p<0.01).

CONCLUSIONS

The initial abnormalities of sodium metabolism in cirrhosis might be characterized by blunted renal responsiveness to natriuretic peptides. The results of the study also provide indirect evidence that the impairment is mainly located at postreceptor levels of signal transduction pathway to the peptides, if the activation of antinatriuretic factors other than renin-angiotensin or sympathoadrenergic systems does not play a role.

Medical check of competitive canoeists

We gave a sports injury questionnaire survey to 821 active canoeists, members of the Japan Canoe Association (JCA), and performed a medical check of 63 top competitive JCA canoeists, including physical and laboratory tests and radiographic examinations of the chest, spine, shoulder, elbow, and wrist joints. Completed questionnaires were returned by 417 canoeists, whose reported racing styles were: kayak, 324; Canadian canoe, 71; slalom, 13; and not specified, 9. Of the 417 respondents, 94 canoeists (22. 5%) reported that they experienced lumbago; 20.9% experienced shoulder pain; 3.8%, elbow pain; and 10.8%, wrist pain. On medical examinations, lumbago was found to be mainly of myofascial origin or due to spondylolysis. Impingement syndrome was also observed in 4 canoeists with shoulder problems. The competitive canoeists had low blood pressure, and some had bradycardia. On laboratory examinations, serum hemoglobulin, hematocrit, high-density lipoprotein cholesterol (HDL-CHO), creatine phosphokinase (CK), and creatine (CRTN) in the top competitive canoeists showed high values in comparison with those of an age-matched control group. However, low serum total cholesterol (TP) values were observed in the top competitive canoeists.

Subclinical syphilitic hepatitis, which was markedly worsened by a Jarisch-Herxheimer reaction

Early syphilitic hepatitis is uncommon and tends to be overlooked. However, the diagnosis of this disease is important, because appropriate treatment results in rapid resolution of the hepatitis. We report a case of subclinical early syphilitic hepatitis exaggerated by a Jarisch-Herxheimer reaction. This reaction helped to realize the diagnosis in this case.

Evaluation of the antioxidative activity of tea by an oxygen electrode method

The antioxidative activity was studied for 25 kinds of tea and catechins by a new evaluation method using an oxygen electrode. The concentration of catechins in 6 types of green tea was analyzed by HPLC. The result indicates that the antioxidative activity of green tea depends to some extent on the amount of catechins present.

The unusual presentation of mucinous carcinoma in the colon making preoperative diagnosis difficult: report of a case

A 51-year-old man was admitted to our hospital for investigation of fever, lower abdominal pain, and pain on micturition. Barium enema and endoscopic findings revealed an extracanal large cavity of the rectosigmoid colon, which suggested an abscess caused by penetration. Histological examination of the endoscopic biopsy specimen demonstrated no malignancy. A preoperative diagnosis of malignant lymphoma was strongly suspected from the imaging findings; however, intraoperative inspection revealed a large tumor invading the urinary bladder. An intraoperative incisional biopsy was performed and histological examination demonstrated mucinous carcinoma. The patient subsequently underwent pelvic exenteration about 1 week later followed by adjuvant chemotherapy and radiotherapy.

Intimal neovascularization in human coronary atherosclerosis: its origin and pathophysiological significance

To investigate the histopathological characteristics of the newly formed vessels in the atherosclerotic intima of human coronary arteries, we conducted postmortem angiography in 31 cases, including 11 with myocardial infarction. Vessels were examined three-dimensionally under the stereoscope. In addition, we evaluated 25 anterior descending coronary arteries unrelated to the occurrence of myocardial infarction by light microscopy using 3-mm stepwise sections and 5-microns serial sections. Histological alterations were analyzed morphometrically to determine the correlation between the degree of intimal neovascularization and the growth of the endothelium into the atherosclerotic intima from the adventitia or lumen. There was a significant positive correlation between the density of new vessels in the intima and the incidence of luminal stenosis, the extent of chronic inflammatory infiltrate, the formation of granulation tissue, or the atheromatous changes, whereas the vascular density decreased in the extensively hyalinized and calcified intima. The newly formed intimal vessels originated mainly from the adventitial vasa vasorum and also partly from the proper coronary lumen. The intimal vessels that originated from the adventitia occurred approximately 28 times more frequently than those that originated from the luminal side. The frequency of former vessels increased as the luminal stenosis became more severe, whereas the latter vessels were found most frequently in the presence of 40% and 50% stenosis. Vessels originating from the proper lumen were more often associated with fresh or old hemorrhage. We conclude that intimal neovascularization largely originates from the adventitia and is closely associated with the extent of coronary stenosis and the histological inflammatory reaction.

Spontaneous complete regression of high grade non-Hodgkin's lymphoma. Morphologic, immunohistochemical, and gene amplification analyses

BACKGROUND

Spontaneous regression of non-Hodgkin's lymphoma, occasionally reported in low grade groups, is a rare phenomenon in high grade groups. Clonal proliferation has not been confirmed in the majority of reported cases. In this woman, age 58 years, who had been diagnosed as having high grade immunoblastic lymphoma after excision of a single cervical lymph node, the remaining bilateral cervical, inguinal, and axillary adenopathy regressed completely without any cytotoxic treatments 22 days after biopsy. At the time of this writing, the patient has been free of disease for 24 months.

METHODS

Clonality of the lymphoproliferation in the case was examined by immunohistochemistry and polymerase chain reaction (PCR) amplification using paraffin embedded biopsy material. Possible implications of Epstein-Barr virus in the pathogenesis of this process was examined also by PCR amplification and in situ hybridization.

RESULTS

The proliferating lymphoid cells showed restricted expression of immunoglobulin (Ig) light chain and amplification of clonally rearranged V-D-J regions of Ig heavy chain gene. Epstein-Barr virus did not appear to be involved in the process.

CONCLUSION

The present study shows that spontaneous complete regression of clonal lymphoproliferation that is morphologically a high grade lymphoma can occur.

A new improved technique for placement of a pursestring suture on the edge of the distal part of the rectal stump using a skin stapler for low anterior resection

Instead of a linear stapler or manual pursestring suture onto the lower part of the rectum, we placed a No. 2-0 Prolene suture on the edge of the rectal stump, using 12 to 16 clips and a disposable skin stapler. This technique is satisfactory for very low anterior resection.

Endothelial Function in Thrombosis and Thrombolysis

The localization of tissue factor (TF) in atherosclerotic plaques of human aortas was immunohistochemically examined using rabbit anti-IgG against recombinant TF, which was expressed in E. coli. TF, the initiator of the extrinsic coagulation pathway, was ubiquitously present in atherosclerotic intima, and was expressed mainly by macrophages, but not by endothelial cells. It has been suggested that some macrophages in atherosclerotic intima co-express both molecules of TF and platelet-derived growth factor-B chain. We have developed a morphometrically quantitative in vitro assay for angiogenesis, using endothelial cultures on collagen gel incorporating plasminogen. With this method, we have obtained findings suggesting that plasminogen and plasminogen activators (PAs), especially urokinase-type PA (uPA) derived from endothelial cells, enhance angiogenic activity, probably by increasing endothelial migration. uPA was immunohistochemically observed to be primarily cell-associated on the focal contract areas, probably via its receptors on endothelial cells. These findings may support the hypothesis that the activation and regulation of the pericellular fibrinolysis system is closely related to angiogenesis.

Electric discharge patterns of ankle muscles during the normal gait cycle

EMG patterns in ankle muscles were examined during normal gait cycles in 147 healthy asymptomatic adults. In all subjects, the tibialis anterior (Ta) showed marked activities around the toe-off and before the heel-strike, and the gastrocnemius lateral head (Gl) showed marked activity during the midstance phase but no activity in the early part of the swing phase. The Ta activity contributed to ground clearance, prevention of foot-drop, and shock absorption at the heel-strike. The Gl activity contributed to push-off from the ground and prevention of foot-drop. The Ta activity consisted of double bursts with (15% of subjects) or without (44%) electric silence in the midswing phase, continuous discharge (33%), and triple discharge patterns (8%). The Gl activity consisted of a single-peak (95%) pattern or double-peak (5%) patterns.

Sustained arterial injury and progression of atherosclerosis

In this paper the following findings were described: 1) Murine arteriosclerosis induced by immune challenge was ultrastructurally characterized by intimal monocyte-macrophage recruitment and minor endothelial alterations; 2) Atherosclerotic lesions of human coronary arteries exhibited frequently segmental or patchy neovascularization, probably representing a response to intimal injury as an example of repair process. Newly formed blood vessels in the intima were derived from both adventitial and luminal endothelial growth; 3) Angiogenesis in vitro was related to the activation of fibrinolytic system especially via the autocrine production of u-PA from endothelial cells, and this process was modulated by cytokines and TGF beta. These findings add more evidence for the hypothesis that the chronic inflammation-repair process plays an essential role in the initiation and progression of atherosclerosis.

Sequential appearance of host-derived T cell subsets during differentiation in nude mice grafted with rat fetal thymus

To elucidate the abnormality of T cell differentiation in nude mice grafted with rat fetal thymus that develop multiple-organ-localized autoimmune diseases, we examined sequential appearance of T cell subsets and expression of TCR genes in BALB/c nude mice after grafting with fetal F344 rat thymus. We observed progressive expression of TCR gamma/delta-alpha/beta genes in the lymph node (LN) cells from 8 to 12 wk after grafting. An appreciable number of CD4+ T cells but few CD8+ T cells were detected in the LN at 8 wk after grafting. CD8+ T cells increased slowly in number by 12 wk after grafting but remained at a low level in comparison with those in nude mice 12 wk after grafting with BALB/c thymus. In correlation with an increase in the number of T cells expressing TCR alpha/beta genes, alloreactivity as assessed by MLR was increased to a normal level. However, CTL activity against alloantigens remained at a low level in the LN cells at 12 wk. At this stage, organ-specific autoimmune diseases and a high level of anti-DNA autoantibodies were detected. In these mice host-reactive T cells such as V beta 3- or V beta 11-bearing T cells were virtually eliminated in the peripheral mature T cell pool, whereas T cells maturing in the fetal rat thymus significantly proliferated in response to donor-rat stimulator cells. These results suggest that the development of the autoimmune diseases may be ascribed to an impaired maturation of CD8+ T cells but not to failure in clonal elimination of host-reactive T cells in nude mice grafted with rat thymus.

Sequential appearance of host-derived T cell subsets during differentiation in nude mice grafted with rat fetal thymus

To elucidate the abnormality of T cell differentiation in nude mice grafted with rat fetal thymus that develop multiple-organ-localized autoimmune diseases, we examined sequential appearance of T cell subsets and expression of TCR genes in BALB/c nude mice after grafting with fetal F344 rat thymus. We observed progressive expression of TCR gamma/delta-alpha/beta genes in the lymph node (LN) cells from 8 to 12 wk after grafting. An appreciable number of CD4+ T cells but few CD8+ T cells were detected in the LN at 8 wk after grafting. CD8+ T cells increased slowly in number by 12 wk after grafting but remained at a low level in comparison with those in nude mice 12 wk after grafting with BALB/c thymus. In correlation with an increase in the number of T cells expressing TCR alpha/beta genes, alloreactivity as assessed by MLR was increased to a normal level. However, CTL activity against alloantigens remained at a low level in the LN cells at 12 wk. At this stage, organ-specific autoimmune diseases and a high level of anti-DNA autoantibodies were detected. In these mice host-reactive T cells such as V beta 3- or V beta 11-bearing T cells were virtually eliminated in the peripheral mature T cell pool, whereas T cells maturing in the fetal rat thymus significantly proliferated in response to donor-rat stimulator cells. These results suggest that the development of the autoimmune diseases may be ascribed to an impaired maturation of CD8+ T cells but not to failure in clonal elimination of host-reactive T cells in nude mice grafted with rat thymus.

[Two cases of malignant cardiac tumors attached on the anterior mitral valve]

Two cases were reported in which malignant cardiac tumors attached to the mitral valve were diagnosed during their lifetimes using two-dimensional echocardiography. Case 1 was a 29-year-old man with speech disturbance and left hemiparesis. Histological examination of the specimen excised from the cardiac tumor during the operation revealed mesenchymal chondrosarcoma, which is extremely rare etiologically and has never been reported so far. Case 2 was a 62-year-old woman complaining of paroxysmal nocturnal dyspnea and chest pain. The diagnosis of malignant histiocytosis was made from the pathological examination of biopsy specimen taken from the rib metastasis. Using two-dimensional echocardiography, characteristic findings for the cardiac tumor were obtained. The tumor echo in Case 1 showed, unlike to that reported for myxoma, two different echogenic layers; the outer dense and the inner light in the echo density. On surgery, tumor echo was revealed to reflect the cystic lesion. In Case 2, two-dimensional echocardiography on admission revealed two separate tumor echoes which attached to the mitral valve and left atrial wall region, respectively. Within two months, they grew rapidly and finally fused into one mass resulting in so-called ball valve syndrome. Phonocardiographically, the tumor plop in Case 1 was high-pitched in quality, and was extinguished completely after the tumor was resected. The tumor plop in Case 2 was not audible on admission, but became evident after fusion of the tumor echoes and was associated with a presystolic murmur.

Effects of conditioning polarization on the membrane ionic currents in rat myometrium

Membrane ionic currents were measured in pregnant rat uterine smooth muscle under voltage clamp conditions by utilizing the double sucrose gap method, and the effects of conditioning pre-pulses on these currents were investigated. With depolarizing pulses, the early inward current was followed by a late outward current. Cobalt (1 mM) abolished the inward current and did not affect the late outward current per se, but produced changes in the current pattern, suggesting that the inward current overlaps with the initial part of the late outward current. After correction for this overlap, the inward current reached is maximum at about +10 mV and its reversal potential was estimated to be +62 mV. Tetraethylammonium (TEA) suppressed the outward currents and increased the apparent inward current. The increase in the inward current by TEA thus could be due to a suppression of the outward current. The reversal potential for the outward current was estimated to be -87 mV. Conditioning depolarization and hyperpolarization both produced a decrease in the inward current. Complete depolarization block occurred at membrane potential of -20 mV. Conditioning hyperpolarization experiments in the presence of cobalt and/or TEA revealed that the decrease in the inward current caused by conditioning hyperpolarization was a result of an increase in the outward current overlaping with the inward current. It appears that a part of the potassium channel population is inactivated at the resting membrane potential and that this inactivation is removed by hyperpolarization.

An electromyographic study on training to pronounce English consonants unfamilar to Japanese

This paper is concerned with the electromyographic analyses of the pronunciation of English consonants as pronounced by a native speaker, a well-trained Japanese, and an untrained Japanese. Six muscles related to movement of the lips and the mandible were tested. The three-paired English words (right--light, she--see, and thank--sank) were selected, as they include consonants that are very difficult for Japanese to pronounce or distinguish correctly when heard. Electromyographic results obtained for the native speaker and the well-trained Japanese indicated light pouting of the lips during the preparatory period for pronouncing [r], raising of the upper lip from the preparatory period in the pronouncing of [sh] and [th], and a downward spreading of the lower lip from the preparatory period in the pronouncing of [l] and [s]. The untrained Japanese subject was given individual and intensive training for several hours with a technique based on electromyographic observation results. Following this, the subject showed improvement in pronouncing the consonants, with the exception of [sh] which the subject had learned to pronounce at a language school. The electromyograms of the subject approached those of the native speaker and the well-trained Japanese.