Gray scale second harmonic imaging of the liver: a preliminary animal study

Gray scale second harmonic imaging (2.5 MHz/5.0 MHz) was evaluated in preliminary animal studies with a new ultrasound contrast agent (FS069). FS069 was administered intravenously in 10 rabbits (6 with normal liver, and 4 with implanted VX-2 tumors) and two woodchucks with hepatocellular carcinomas. The vasculature (including tumor vessels) and liver parenchyma were clearly enhanced at a low dosage (optimal dose was from 0.1 to 0.2 mL/kg) in all cases. Enhancement was reproducible and generally dose-dependent. Tumors were enhanced well during the early phase and tumor enhancement disappeared earlier than that of surrounding normal liver. Arterial phase and portal phase were easily distinguished and patterns of enhancement were diagnostic of the tumors. Gray scale second harmonic imaging is useful in the detection of hepatic tumors and in diagnosis of their hemodynamics.

Alteration of midkine expression associated with chemically-induced differentiation in human neuroblastoma cells

Midkine (MK), a neurotrophic polypeptide of which expression is developmentally regulated in embryogenesis, is expressed in malignant tumor tissues including neuroblastoma (NB). A retinoic acid analogue, E5166, and dibutyryl cyclic AMP (dbcAMP) are known to induce differentiation in NB cells. This study showed that MK mRNA expression increased in association with differentiation by E5166, but not by dbcAMP in SK-N-SH and KP-N-RTBM1 human NB cell lines. We concluded that MK could be an important factor in differentiation of NB cells, and further, that there could be at least two pathways in differentiation of NB cells at molecular mechanism.

Immunohistochemical analysis of nucleoside diphosphate kinases in oral squamous cell carcinomas

The nm23 gene is a potential metastasis suppressor gene originally identified using a murine melanoma cell line. The nm23 proteins are nucleoside diphosphate (NDP) kinases, and there are two isotypes in human and other mammalian cells. Immunohistochemical analysis with anti-rat NDP kinase (NDP kinase alpha, NDP kinase beta) monoclonal antibodies was performed in deparaffinized sections of 56 specimens of oral squamous cell carcinoma. Detection of these NDP kinases in tissue samples was correlated with clinical and histopathological factors. The NDP kinase A (nm23 H1 protein)-positive group was apt to have a lower frequency of neck metastasis than the negative one (p < 0.01). Consequently, it is suggested that NDP kinase A might be a metastasis suppressor factor that may be useful for predicting tumor metastases in patients with oral squamous cell carcinoma.

[A case of renal cell carcinoma with hyperglycemia]

A 71-year-old male with hyperglycemia was incidentally found to have a right renal tumor. Hyperglycemia had been controlled by administration of 34 units of insulin. Immediately after radical nephrectomy, hyperglycemia was improved to be able to stop insulin. His fasting blood glucose level remained within normal limits without any treatment. Laboratory studies, however, failed to reveal any endocrinopathy derived from renal cell carcinoma responsible for the diabetic state.

Expression of cytokeratin 14 in ameloblast-lineage cells of the developing tooth of rat, both in vivo and in vitro

In the search for a cell marker useful for studying tooth development, immunohistochemical studies using antibodies against cytokeratin 14 (K14), c-Met/hepatocyte growth factor receptor and amelogenin were carried out in the developing tooth of the newborn rat and in primary cultured cells of the ameloblast lineage, including inner enamel epithelium cells, preameloblasts and ameloblasts, prepared from the mandibular incisors of postnatal 7-day-old rats. The appearance of K14 was cell- and differentiation-stage specific, i.e. there was a weak expression signal within inner enamel epithelial cells that were in the proliferating stage, and there were strong signals within preameloblasts and ameloblasts that were in the post-proliferating and amelogenesis stages, respectively. In the culture system, c-Met appeared in all cells, whereas K14 and amelogenin appeared mainly in clustered cells that were considered to be in the post-proliferating stage. K14 was detected earlier than amelogenin, and it was also confirmed by immunofluorostaining that c-Met, K14 and amelogenin were coexpressed in ameloblasts. These findings indicate that K14 is a good new marker for ameloblast-lineage cells during rat tooth development both in vivo and in vitro.

MAGE-1 and MAGE-3 or -6 expression in neuroblastoma-related pediatric solid tumors

MAGE-1 and MAGE-3 or -6 are genes encoding melanoma-rejection antigens recognized by cytotoxic T lymphocytes in an HLA-A1 restriction manner. MAGE-1 and MAGE-3 or -6 were expressed in 5/14 (36%) and 6/14 (43%) neuroblastoma (NB) cell lines, and in 20/41 (49%) and 24/41 (59%) clinical NB-related tumors, respectively. Additionally, they were also expressed in pediatric tumors of other types such as rhabdomyosarcoma and Wilms' tumor. MAGE-1 expression at a functional level in tumor cells was confirmed by the cytotoxicity assay using MAGE-1-specific tumor-infiltrating lymphocytes (TIL). In clinical NB-related tumors, MAGE-3 or -6 expression demonstrated an inverse correlation to clinical stage. Furthermore, although the sample number was small, the incidence of MAGE-1 and/or MAGE-3 or -6 expression was significantly correlated to the absence of metastasis and a more favorable clinical outcome (p < 0.05). These results may suggest that NB cells silent for the expression of MAGE genes escape from the host anti-tumor immune response and consequently retain a growth advantage. Finally, NB-related tumors could be reliable candidates for immunotherapy targeted towards MAGE gene products.

Seroepidemiological study of Toxoplasma infection in central and western regions in Nepal

The present study was carried out to ascertain the seroprevalence rate in different geographical areas in Central and Western Regions in Nepal. A total of 1,237 serum samples collected from Nuwakot (217), Kathmandu valley (402) and Chitawan (159) districts in Central Region, and Mustang (143), Surkhet (64) and Banke (252) districts in Western Region in Nepal were included in this study. Toxoplasma antibodies were detected by micro-latex agglutination (MLA) and enzyme linked immunosorbent assay (IgM-ELISA) methods. The seropositive rate in Central and Western Regions were found to be 48% and 49%, respectively; with an overall positive rate of 48 percent. Districtwise, the seropositive rate in Nuwakot, Kathmandu valley, Chitawan, Mustang, Surkhet and Banke districts were 38, 46, 64, 51, 67 and 44%, respectively. Interestingly, the relatively newly inhabited Surkhet district in Western Region and Chitawan district in Central Region showed significantly higher seropositive rate compared with those of two other districts in the respective Regions (p < 0.05). Ethnically, Tibeto-Burmans showed higher seropositive rates in Central Region (p > 0.05). In contrast, Indo-Aryans showed higher seropositive rate in Western Region (p > 0.05). Age related increase in seropositivity was observed only in Central Region. One percent of Toxoplasma antibody positive samples also showed Toxoplasma IgM antibody positivity.

Localization of annexin I (lipocortin I, p35) mRNA in normal and diseased human skin by in situ hybridization

Annexin I is a calcium- and phospholipid-binding protein that is involved in the regulation of cellular differentiation. The aim of the present study was to determine the localization of annexin I mRNA expression in normal and diseased human skin. In situ hybridization with a specific digoxigenin-labelled RNA probe was used throughout. We detected no annexin I mRNA signals in basal and suprabasal cells of normal epidermis, but positive signals were evident in the sudoriferous ducts. Annexin I mRNA expression was detected in the keratinizing squamous cells in keratotic type seborrhoeic keratosis and in keratinocytes at the periphery of the horn pearl in well-differentiated squamous cell carcinoma. Positive signals were also seen at the border between involved and noninvolved skin in psoriasis vulgaris and in dyskeratotic epidermal keratinocytes in keratosis follicularis Darier. By contrast, no annexin I mRNA signals were detected in tumour cells in basal cell carcinoma. The present results suggest that annexin I expression is related to, and may play a role in, keratinization disorders.

Lipoprotein(a) induces cell growth in rat peritoneal macrophages through inhibition of transforming growth factor-beta activation

To elucidate the atherogenicity of lipoprotein(a) (Lp(a)), we examined its growth-stimulating activity in rat resident peritoneal macrophages. When macrophages were incubated with Lp(a), cell numbers were increased 1.5-fold as compared with control macrophages. Furthermore, apolipoprotein(a) (apo(a)), a plasminogen-like glycoprotein which is covalently attached to a low density lipoprotein-like particle (Lp(a)), also induced macrophage growth, while the growth-stimulating effect of Lp(a-) was negligible. These results suggest that apo(a) plays an active role in the mitogenic activity of Lp(a). Lp(a)-induced macrophage growth was inhibited by exogenously added active transforming growth factor-beta (TGF-beta) dose-dependently, and also by the addition of plasmin, which converts latent TGF-beta to an active form. Moreover, the amounts of endogenous active TGF-beta in the medium were significantly reduced by the incubation with Lp(a). It is evident from these results that Lp(a) induces macrophage growth by inhibiting TGF-beta activation. The capacity of Lp(a) to stimulate macrophage growth shown here could be novel atherogenic function of Lp(a).

Suppression of atherosclerotic changes in cholesterol-fed rabbits treated with an oral inhibitor of neutral endopeptidase 24.11 (EC 3.4.24.11)

Neutral endopeptidase 24.11 (NEP), widely distributed in the body, hydrolyzes and inactivates a number of endogenous vasoactive peptides, some of which could alter various functions of cells present in the arterial wall. Recently NEP has been found to exist in the vascular endothelium. The aim of this study was to assess the influence of chronic NEP inhibition by daily administration of UK79300 (candoxatril), an orally active NEP inhibitor (NEPI), on the development of atherosclerotic changes in high-cholesterol-fed rabbits. Male New Zealand White rabbits were fed for 8 weeks as follows: normal rabbit diet (Normal, n = 15), 1.5% cholesterol diet (Cholesterol, n = 15), or 1.5% cholesterol diet containing NEPI (20 mg.kg-1.d-1) (Cholesterol+NEPI, n = 15). At the end of the dietary period, NEPI treatment was found to suppress the surface area of the aorta covered by plaques (% surface area: Cholesterol, 59 +/- 6 versus Cholesterol+NEPI, 36 +/- 7, P < .01) and decreased contents of cholesterol and cholesterol esters in the aortas. NEPI also reduced plasma total cholesterol by 27% of Cholesterol rabbits (1781 +/- 130 mg/dL). The endothelial function, estimated by the endothelium-dependent relaxation of the isolated aortas in response to acetylcholine, was preserved in Cholesterol+NEPI rabbits compared with that in Cholesterol rabbits. NEP enzymatic activities in plasma and the particulate fraction of the homogenates from the aortas in Cholesterol rabbits were both increased, 3.1- and 3.9-fold, respectively, above those in Normal rabbits, but the activities in Cholesterol+NEPI rabbits were significantly lower than those in Cholesterol rabbits. UK73967, an active form of UK79300, or phosphoramidon partly reversed the atherosclerotic impairment of relaxation of the isolated thoracic aortic rings from Cholesterol rabbits in response to exogenous additions of C-type natriuretic peptide (CNP) and substance P, which are NEP substrates known to exist endogenously in the vascular endothelium. The results suggest that the increased NEP activity plays a significant role in atherogenesis, and NEPIs might be therapeutically useful in the prevention of atherosclerosis. Reduction of plasma cholesterol and suppression of degradations in the arteries of endogenously released CNP, substance P, or possibly other kinins known to have anti-atherosclerotic actions may at least partially contribute to the inhibitory effects of NEPIs on atherosclerotic changes.

p53 and MDM2 expression in oral squamous cell carcinoma

The p53 tumor suppressor gene is the most commonly mutated gene in human cancer and is a frequent abnormality in oral squamous cell carcinoma and its precancerous lesions. MDM2 (murine double minute-2), a new proto-oncogene, may be associated with p53 gene products and may negatively affect the transcriptional activating function of p53. The purpose of this study was to investigate the incidence of MDM2 and its relationship to the expression of p53 in oral squamous cell carcinoma and precancerous lesions. Overexpression of p53 and MDM2 proteins was detected in 52 and 40% of oral squamous cell carcinomas, respectively. p53 gene mutation, absent in normal oral epithelium was observed in 31% of the carcinoma cases. Our finding suggested that MDM2 protein may be an alternative mechanism causing p53 protein dysfunction in oral squamous cell carcinoma.

Analysis of reconstruction of mandibular defects using single stainless steel A-O reconstruction plates

PURPOSE

This report reviews the results and complications of immediate reconstruction using a single stainless steel A-O plate after resection of mandibles invaded by malignant tumors.

PATIENTS AND METHODS

Thirty-four patients were retrospectively evaluated. According to the extent of the tumor, hemimandibulectomy or segmental resection were performed in 4 and 30 cases, respectively. Five of 34 cases required a myocutaneous flap to close soft tissue defects.

RESULTS

Nine of the 34 patients died during the follow-up period. Complications occurred in 7 of these patients: plate exposure was caused by local tumor recurrence (4 cases), screw loosening (1 case), and temporomandibular joint pain (2 cases). Twenty-five of the 34 patients (73.5%) were alive, with a mean follow-up of 47.4 months (range 6 to 115 months). Eighteen of the 25 surviving patients with the single A-O plate reconstruction did not show any complications. Thirteen of these (52%) patients had not undergone secondary reconstruction. Five of the 25 patients received secondary reconstruction for cosmetic or masticatory function reasons. Postoperative complications occurred in 7 of the 25 surviving patients (28%): extraoral plate exposure (2 cases), fracture of the plate (1 case), mandibular fracture (1 case), screw loosening (3 cases), and screw fracture (1 case).

CONCLUSIONS

On the basis of the findings, it was concluded that a single A-O reconstruction plate can be used for temporary, or sometimes even permanent, reconstruction after mandibular resection.

Glucagon-like peptide-1(7-36)amide enhances insulin-stimulated glucose uptake and decreases intracellular cAMP content in isolated rat adipocytes

We investigated the effect of GLPs on glucose uptake in isolated rat adipocytes. GLP-1(7-36)amide significantly enhanced glucose uptake in the presence of 1 nM insulin. GLP-1(7-36)amide at 15 nM increased glucose uptake maximally by 56.4% as compared with 1 nM insulin alone (P < 0.01). In contrast, with less than 1 nM insulin or without insulin GLP-1(7-36)amide showed no effect on glucose uptake. Full-sequence GLP-1(1-37) at 15 nM in the presence of 1 nM insulin increased glucose uptake by 24.6% as compared with 1 nM insulin alone (P < 0.05). GLP-2 showed no effect on glucose uptake. Further, we examined the effect of GLP-1(7-36)amide on cAMP content in isolated rat adipocytes. Insulin at 1 nM caused a significant decrease of cAMP content. The combination of 15 nM GLP-1(7-36)amide and 1 nM insulin caused a further reduction of cAMP content. These data indicate that GLP-1(7-36)amide possesses augmentative effects on insulin action in isolated rat adipocytes. Furthermore, it is suggested that the stimulatory effect of GLP-1(7-36)amide occurs through the reduction of intracellular cAMP content.

Seroepidemiological study of Toxocara infection in Nepal

Seroepidemiological study of Toxocara infection in Nepalese people aged more than fourteen years was carried out by enzyme linked immunosorbent assay (ELISA) using T. canis soluble embryonated egg antigen. Of the total 200 subjects included in this study, 162 (81%) were found to possess antibodies to Toxocara spp. Males showed higher (85%) antibody positive rates than females (77%). Inhabitants of Kathmandu valley showed higher antibody positive rates (84%) compared with those living outside of the valley (78%). These differences, however, were not significant statistically (p > 0.05). Ethnically, Newar, Rai/Limbu, Tamang/Sherpa, Brahmin/Chhetri, Jha/Yadavs, and others (Kami, Damai) showed Toxocara antibody positive rates of 85, 85, 83, 70, 77 and 100%, respectively. Half of the Toxocara antibody positive subjects (49%) showed an elevated level (two plus) of antibody.

Neutral endopeptidase 24.11 in neutrophils modulates protective effects of natriuretic peptides against neutrophils-induced endothelial cytotoxity

This study was performed to determine effects of atrial and brain natriuretic peptides (ANP, BNP) on neutrophils-induced endothelial injury which is known to play a role in the pathophysiology of ischemia/reperfusion myocardial injury and to examine whether the effects of ANP and BNP on neutrophils are modulated by neutral endopeptidase 24.11 (NEP) in neutrophils themselves. The incubation of human neutrophils with ANP and BNP inhibited the neutrophils-induced detachment of cultured human endothelial cells (HEC). The inhibitory effect of ANP and BNP was associated with the suppressions of the neutrophils adhesiveness to HEC, CD18 expression on the neutrophils and elastase release from the neutrophils. Coincubation with UK73967 or phosphoramidon, inhibitors of NEP, potentiated all of the effects of ANP and BNP on the neutrophil functions, and the NEP inhibitors protected degradation of ANP and BNP by the neutrophils. NEP enzymatic activity in the particulate fractions and immunoreactive NEP expression were found to increase in the neutrophils from patients with early phase of acute myocardial infarction (AMI) by 5.2- and by 4.2-fold of the neutrophils from patients with late phase of AMI, respectively. In an in vivo canine model of myocardial ischemia/reperfusion, the intravenous administration of UK73967 suppressed the neutrophil adherence to endothelium and the neutrophil accumulation in the ischemic/reperfused myocardium. The results indicate that ANP and BNP, which are known to increase in AMI, modulate the neutrophil functions and exert protective effects against the neutrophils-induced endothelial cytotoxity. But the effects are suppressed due to their degradation by the neutrophil own NEP. Thus, neutrophil NEP, which also increases in AMI, may play a role in the pathophysiology of neutrophils-mediated ischemia/reperfusion endothelial and myocardial injury.

Sequential expression of myc-, ras-, oncogene products and EGF receptor during DMBA-induced tongue carcinogenesis

The mechanism leading to development of oral cancer has not been completely understood. It is currently believed that alternation of a number of genes can result in the development of epidermoid carcinomas. In this investigation, we used a 9,10-dimethyl 1,2-benzanthracene (DMBA)-induced carcinogenesis in a hamster tongue model to investigate the expression of c-myc, c-Ha-ms proteins and epidermal growth factor receptor (EGFr). During the DMBA-carcinogenesis of the tongue, the number of c-myc protein positive cells were increased in epithelial dysplasia and elevated throughout the process of tumorigenesis. The expression of c-Ha-ras protein was detected in normal epithelium. The level of c-Ha-ras protein expression was decreased in the dysplastic stage, and it was almost negative in squamous cell carcinomas. Detection of EGFr overexpression occurred only after 1-4 weeks of DMBA treatment, at a very early stage of tumor development, and increased through carcinogenesis varying individually within the malignant tissues. These results suggest that c-myc protein and c-Ha-ras protein expression may have an important role in malignant transformation, and the overexpression of EGFr can be correlated to very early stages of tumor development in the DMBA-induced in vivo tongue carcinogenesis.

Lysophosphatidylcholine potentiates the mitogenic activity of modified LDL for human monocyte-derived macrophages

The growth of murine peritoneal macrophages is induced by oxidized LDL (Ox-LDL), and lysophosphatidylcholine (lysoPC) plays an important role in its mitogenic activity. In the present++ study, Ox-LDL-induced macrophage growth was examined with human monocyte-derived macrophages. The cell growth of human macrophages was significantly induced by Ox-LDL but not by acetylated LDL (acetyl-LDL). The treatment of acetyl-LDL with phospholipase A2, however, led to a marked increase in its mitogenic activity, with a concomitant conversion of 75% of its phospholipids to lysoPC. The growth-stimulating activity became positive only when both acetyl-LDL and lysoPC were coincubated, although neither of them exhibited cell growth-promoting activity. These results suggest that Ox-LDL could stimulate the growth of human monocyte-derived macrophages, and lysoPC may play an essential role in the mitogenic activity of Ox-LDL.

[Chemotherapy for B lymphoid malignancy in childhood--results in BLK88 protocol]

Ten cases of newly diagnosed pediatric B cell non-Hodgkin's lymphoma or acute lymphoblastic leukemia (B-NHL, stage I & II 6 cases, stage III & IV 2 cases/ALL 2 cases) experienced during the last 7 years (1987-1994) were treated by BLK88 protocol, which consisted of HD-CPM (1,200 mg/m2), and HD-MTX (1,000 mg/m2) with VCR, ADR, and/or AraC combination, and CNS prophylaxis by triple intrathecal injection. The therapy duration was 24 weeks for B-NHL (36 weeks for B-ALL). The results showed that while one of the six cases in stage I & II relapsed, and other 4 cases of stage III & IV B-NHL/ALL remained in complete remission. On the other hand, all of the four cases in stage III & IV in historical controls had relapsed. Neutropenia and liver dysfunction were observed during therapy, but they were tolerable. We conclude that BLK88 is a very useful protocol for B-NHL/ALL in childhood.

[Comparative study on serological diagnosis of entamoebiasis histolytica]

The practicability of four diagnostic methods for entamoebiasis histolytica including micro-gel diffusion precipitin test (MGDP), indirect immunofluorescent antibody test (IFA), indirect hemagglutination test (IHA) and enzyme-linked immunosorbent assay (ELISA) was evaluated. The serological test methods were compared by using sera obtained from 30 entamoebiasis histolytica patients and 130 normal health individuals. The highest sensitivity was obtained with the method of ELISA, followed by IFA and IHA : the lowest was obtained with MGDP. On the contrary, the high specificity was obtained with IHA, IFA, MGDP : the lowest was obtained with ELISA. Intensity of the antibody titers in IHA was correlated well with that of IFA. In addition, we studied antibodies nonspecifically reactive to Entamoeba histolytica in sera from E. histolytica-negative individuals with high CRP patients with regard to the sensitivity and specificity. Among 101 sera examined, six showed false positive results of which five were the sera with extremely high CRP.

[A case of idiopathic spinal cord herniation]

The authors experienced a case of idiopathic spinal cord herniation with duplicated dura mater. A 63-year-old woman presented right dominant slowly progressive spastic paraplegia and dissociated sensory disturbance. Magnetic resonance imaging (MRI) demonstrated an enlarged dorsal arachnoid space associated with an apparently focally narrowed thoracic cord. The cord was kinked towards the anterior and closely applied to vertebral body at the level of Th3-4. Computed tomographic myelography (CTM) revealed homogeneous filling at dorsal arachnoid space immediately after injection and no defects. At operation multilocular arachnoid cyst and duplicated dura mater was respectively observed dorsally, and ventrally. From defected area of the inner layer, a ventral part of the spinal cord was incarcerated between the two dural layers. After rejection of arachnoid cyst and inner layer was performed, the patient recovered neurologically. Idiopathic spinal cord herniation is a rare disease that shows slowly progressive myelopathy at middle age. The herniations were observed at ventral thoracic cord in all reported cases. The mechanism of this disease is still uncertain. But at least three successive factors seem to be necessary for formation of herniation, 1) abnormal structure of the dura mater such as defect, diverticulum and duplication; 2) adhesion between the cord and the destructive dura mater, and 3) continuous cerebrospinal fluid (CSF) pressure pushing the cord outward from subdural space. In the thoracic spine, mobility is limited compared with the cervical and lumbar spine, and because of physiological curvature the cord situates rather ventrally. For these reasons the incidence of adhesion might be higher at ventral thoracic spine. Although neuroradiological imagings especially MRI and CTM were useful, operative findings were necessary for definitive diagnosis in many reported cases. Considering the effectiveness of surgical treatment, study of the ventral side of the cord should be important to avoid misdiagnosis.

Hepatocyte growth factor is involved in the morphogenesis of tooth germ in murine molars

The patterns of gene expression for hepatocyte growth factor (HGF) and its receptor, c-Met, were revealed in the tooth germ of rat mandibular molars using RT-PCR. In situ hybridization demonstrated that the HGF gene was expressed only in the cells of the dental papilla of the tooth germ in vivo. The characteristic temporospatial distribution of HGF and c-Met during germ development was revealed using immunohistochemical studies in vivo. In order to demonstrate the functional role played by HGF in tooth development, HGF translation arrest by antisense phosphorothioate oligodeoxynucleotide (ODN) was carried out in vitro. In the control experiment, explants of tooth germs from embryonic 14 day mice were cultured in a modification of Trowell's system under serum-free and chemically defined conditions for two weeks. Other explants were cultured with 15mer antisense or sense ODN targeted to the HGF mRNA. Both the control and the sense-treated explants showed normal histological structure, as observed in vivo. On the other hand, antisense-treated explants exhibited an abnormal structure in which the enamel organs were surrounded by a thin layer of dentin and dental papilla, appearing ‘inside-out’ compared to the control and sense-treated explants, although the cytodifferentiation of ameloblasts and odontoblasts was not inhibited. The explants treated with recombinant human HGF combined with antisense ODN showed normal development, indicating that exogenous HGF rescued the explants from the abnormal structure caused by antisense ODN. The findings of a BrdU incorporation experiment suggested that the imbalance between the proliferation activity of the inner enamel epithelium and that of the dental papilla caused by HGF translation arrest results in the abnormal structure of the tooth germ. These results indicate that HGF is involved in the morphogenesis of the murine molar.

[Invasive thymoma associated with pure red cell aplasia and lung cancer]

A 71-year-old man was admitted to our hospital with vertigo and general fatigue. Examination of his blood and bone marrow showed pure red cell aplasia. His chest X-ray film revealed an anterior mediastinal mass and a nodular shadow in the right lower lobe. Extended thymothymectomy and right lower lobectomy were done. The mediastinal mass appeared to be an invasive thymoma and the nodular shadow in the right lower lobe proved to be from an adenocarcinoma. The patient was treated with radiation and steroids. Thymoma, pure red cell aplasia, and lung cancer had not recurred and he was alive and well as of 2 years after surgery.