Des-gamma-carboxy prothrombin and proliferative activity of hepatocellular carcinoma

BACKGROUND

Des-gamma-carboxy prothrombin (DCP) is a useful marker for the prognosis of hepatocellular carcinoma (HCC). In this report we investigated the relationship between the positivity of DCP and proliferative activity of HCC and discuss the cause of poor prognosis of DCP-positive HCC.

METHODS

Immunohistochemical and clinicopathologic study was done in 114 patients with resected HCC measuring less than 6 cm in diameter by using monoclonal antibody for proliferating cell nuclear antigen (PCNA).

RESULTS

PCNA labeling index (PCNA-LI) was significantly higher in the patients with DCP-positive HCC than in those with DCP-negative HCC; also a positive correlation was noted between the PCNA-LI and the DCP level. We divided patients into two groups according to the PCNA-LI. In the high PCNA-LI group the patients with DCP-positive HCC exhibited a higher PCNA-LI than did the patients with DCP-negative HCC. As for pathologic prognostic factors, the DCP-positive high PCNA-LI group showed the highest incidence of tumor thrombus of the portal vein and intrahepatic metastasis while also exhibiting the lowest recurrence-freedom rate. From multivariate analysis we find that DCP, as well as PCNA-LI, is one of the risk factors for recurrence of HCC after hepatectomy.

CONCLUSIONS

Our results thus suggest that DCP-positive HCC showed high PCNA-LI, and this might be the main cause for early intrahepatic spread and poor prognosis of DCP-positive HCC.

Effects of size of carbohydrate chain on protease digestion of Aspergillus niger endo-beta-1,4-glucanase

Three different carbohydrate-depleted enzymes were prepared from an endo-beta-1,4-glucanase of Aspergillus niger IFO31125 by treatment with endo-beta-N-acetylglucosaminidase or alpha-mannosidase. They were purified by Concanavalin A-Sepharose affinity and DEAE ion-exchange column chromatographies. The molecular sizes of these enzymes had been decreased from 40 kDa containing 9.0% carbohydrate to 39, 38, and 37 kDa with carbohydrate at 4.5, 1.3, and 0.8% (wt/wt), respectively. The native and these carbohydrate-depleted enzymes were compared in their enzymatic properties, and it was found that they were identical in their catalytic activities and both thermal and pH stabilities. However, the 37-kDa enzyme was more susceptible to proteolysis by Savinase, proteinase K, and Pronase E. On the other hand, the specific protease trypsin showed no such effect on activity of all enzymes. These results suggested that the core structure of the asparagine-linked sugar chain, which consisted of three monosaccharide residues, contributed to the high stability of the endo-beta-1,4-glucanase against protease digestion.

The coagulation system is activated in idiopathic cardiomyopathy

OBJECTIVES

We investigated the plasma levels of molecular markers for platelet activity and the thrombotic and fibrinolytic status in patients with hypertrophic cardiomyopathy and dilated cardiomyopathy to determine the activating site of coagulation in these disorders.

BACKGROUND

A thromboembolic event is a serious complication in patients with idiopathic cardiomyopathy. However, the activating site of the coagulation system in idiopathic cardiomyopathy has not been fully investigated.

METHODS

We determined the plasma levels of molecular markers for platelet activity (platelet factor 4 and beta-thromboglobulin), thrombotic status (fibrinopeptide A and thrombin-antithrombin III complex) and fibrinolytic status (D-dimer and plasmin-alpha 2-plasmin inhibitor complex) in 13 patients with hypertrophic cardiomyopathy, 17 patients with dilated cardiomyopathy and 20 normal subjects.

RESULTS

Plasma levels of platelet factor 4, beta-thromboglobulin and plasmin-alpha 2-plasmin inhibitor complex did not differ significantly among the three groups, whereas plasma levels of fibrinopeptide A and thrombin-antithrombin III complex in both patient groups were significantly higher than those in normal subjects. Plasma levels of D-dimer in patients with dilated cardiomyopathy were significantly higher than those in patients with hypertrophic cardiomyopathy and normal groups. In patients with hypertrophic cardiomyopathy, both fibrinopeptide A and thrombin-antithrombin III complex levels were significantly correlated with left atrial diameter. In patients with dilated cardiomyopathy, fibrinopeptide A and thrombin-antithrombin III complex levels showed a positive correlation with left ventricular end-diastolic volume and a negative correlation with fractional shortening of the left ventricle.

CONCLUSIONS

The activated coagulation system in patients with hypertrophic and dilated cardiomyopathy may be triggered by left atrial dilation in hypertrophic cardiomyopathy and left ventricular enlargement and dysfunction in dilated cardiomyopathy.

Studies of radioimmunoassay for measurement of insulin-like growth factor-I (IGF-I) by using anti-IGF-I monoclonal antibody

Radioimmunoassay system for measurement of insulin-like growth factor-I (IGF-I) was established by using anti-recombinant human IGF-I monoclonal antibody (MAb). This MAb is capable of recognizing not only human but also rat IGF-I. It was thus suggested that this RIA system can quantify IGF-I in human and rat sera. MAb used in this paper was clarified to be an antibody against the common epitope of C-region of human and rat IGF-I. Gly32-Ser33-Ser34 sequence of C-region of IGF-I is discussed to be an antigenic determinant to which this antibody might specifically bind. MAb does not cross-react with proinsulin and insulin as well as anti-IGF-I polyclonal antibody (PAb). And it is general that PAb has almost 2% cross-reactivity with IGF-II. But this MAb did not cross-react with IGF-II. Actually, the value of IGF-I measured by this system was lower than that measured by RIA using PAb.

Plasma exchange in chronic inflammatory demyelinating polyradiculoneuropathy; different beneficial effects and their correlation to the clinical features

We report 7 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) who showed significant clinical improvement by plasma exchange (PE). Their clinical features were extensively varied but fulfilled the diagnostic criteria for CIDP. The patients could be divided into 2 subgroups based on the mode of effectiveness of PE; one group consisted of those who once achieved complete remission, but required highly frequent PEs for long-term maintenance of remission and the others were those who showed persistent and complete remission with several sessions of PE alone. These findings raise issues about the long-term therapeutic goals to be achieved by PE for CIDP patients, particularly on supportive therapy other than PE, as well as the optimization of frequency and duration of PE.

Cloning and sequencing of a novel hemolysis gene of Vibrio cholerae

A hemolysis gene (hlx) which lyses sheep erythrocytes on blood agar plates when expressed in Escherichia coli was cloned from Vibrio cholerae. The cloned gene is predicted to encode a polypeptide of 92 amino acid residues with a deduced molecular mass of 10,451. E. coli transformed with this gene lysed sheep, goose, horse and chicken erythrocytes but not those of guinea pig and human. The hlx gene was observed in classical- and El Tor-biotype V. cholerae O1, V. cholerae non-O1, and V. mimicus, but not in V. parahaemolyticus.

Molecular cloning of a novel actin-binding protein, p57, with a WD repeat and a leucine zipper motif

A 57 kDa protein (p57) was obtained during the study on phosphatidylinositol-specific phospholipase C. Its cDNA was isolated from calf spleen and human leukemia cell line HL60 libraries and cloned. In the primary structures of p57, they have two unique amino acid sequence motifs, a WD repeat and a leucine zipper motif. Furthermore, p57 shared sequence similarity (40%) with coronin, an actin-binding protein responsible for chemotaxis, cell motility, and cytokinesis of Dictyostelium discoideum, which has only the WD repeat. p57 also showed an actin-binding activity and was mainly expressed in immune tissues. From these results, we conclude that p57 is a coronin-like novel actin-binding protein in mammalian cells but may also have a different function from coronin.

Combined effects of pravastatin and probucol on high-density lipoprotein apolipoprotein A-I kinetics in cholesterol-fed rabbits

The combined effects of pravastatin and probucol on high- density lipoprotein (HDL) apolipoprotein (apo) A-I kinetics in cholesterol (Ch)-fed rabbits were investigated. Japanese White rabbits were treated with 0.15% pravastatin and 0.5% Ch (group 1) or 0.15% pravastatin plus 1% probucol and 0.5% Ch (group 2) for 2 months. After treatment, the serum total cholesterol levels in groups 1 and 2 had significantly (p < 0.01) increased (37.4 +/- 6.7 mg/dl vs 117.1 +/- 46.4 mg/dl, and 31.4 +/- 4.9 mg/dl vs 143.0 +/- 84.5 mg /dl, respectively). The serum HDL-cholesterol levels in both groups decreased (18.2 +/- 2.8 mg/dl, vs 16.2 +/- 3.7 mg/dl p < 0.01 for group 1; 18.2 +/- 1.9 mg/dl vs 15.5 +/- 4.5 mg/dl, ns for group 2). Apo A-I kinetics were assessed by injecting (125)I-labeled HDL intravenously into both groups of rabbits, and taking blood samples periodically for 6 days. Kinetic parameters calculated from apo A-I specific radioactivity decay curves showed that the apo A-I fractional catabolic rates in rabbits fed pravastatin and Ch (group 1) were significantly less than those in rabbits fed pravastatin plus probucol and Ch (group 2) (0.546 +/- 0.017 /day vs 0.730 +/- 0.126 /day, p < 0.05), while the synthetic rate of apo A-I was lower in group 2 than in group 1 (14.76 +/- 1.71 mg/kg per day vs 11.21 +/- 2.38 mg/kg per day, respectively, p < 0.01). These data indicate that pravastatin and probucol have different effects on HDL-apo A-I kinetics in a diet which includes cholesterol.

Changes in elastin-binding proteins during the phenotypic transition of rabbit arterial smooth muscle cells in primary culture

Elastin, a major constituent of the media, may play an important role in the attachment, migration, and phenotypic properties of vascular smooth muscle cells (SMC). We examined binding proteins and binding sites on elastin in rabbit arterial SMC in primary culture. Freshly isolated cells on alpha-elastin underwent phenotypic transition from a contractile to a synthetic state after 5 days of culture under serum-deficient conditions (1% FBS) and began to proliferate after 6 days of culture (48 h later than on plastic dishes). SMC in the contractile state expressed two binding proteins (130 and 36 kDa), while the 130-kDa band was undetectable in cells in the synthetic state. The adhesion of freshly isolated cells and cells in the synthetic state to alpha-elastin was significantly inhibited by a monoclonal anti-elastin receptor antibody (BCZ-67). The synthetic peptide VGVAPG (Val-Gly-Val-Ala-Pro-Gly), which contains the recognition sequence for the elastin receptor, inhibited the adhesion of freshly isolated cells to alpha-elastin at 0.01-1 mM, but showed no inhibitory activity on the adhesion of cells in the synthetic state at 0.01 mM. These findings suggest that alpha-elastin suppresses the phenotypic transition of rabbit arterial SMC by interacting with the high-molecular-size (130 kDa) binding protein for a cell-binding sequence VGVAPG, while cells in the synthetic state can recognize alpha-elastin through interactions with the low-molecular-size (36 kDa) binding protein for the sequence VGVAPG.

Condensation of collagen fibrils to the direct vicinity of fibroblasts as a cause of gel contraction

Fibroblasts were cultured within FITC-prelabeled type I collagen. Cells initially round in shape protruded processes, and began to collect the fibrils into their vicinity. Repeated protrusion and withdrawal of cell processes was observed. Consequently, condensed fluorescence was observed on the elongated bipolar cells stained with rhodamine-phalloidin. Concomitantly with these events, the gel began to contract in overall size, with an increase of fluorescence intensity. Scanning electron micrographs of the contracted gel showed a disproportional distribution of collagen fibrils: a highly condensed region surrounding cell bodies and a moderately condensed region. A major portion of condensed fibrils may have been derived from reconstituted collagen fibrils, since fibroblasts within collagen gel synthesized little collagen. When the gel adhered to glass tightly, so that overall contraction was prevented, the fluorescence in a range of scores of micrometers from the cells disappeared owing to depletion of fibrils by the cells. The combined spaces with null fluorescence in total under repressed contraction corresponded well to the reduction in volume due to gel contraction. It seems likely that the fibril condensation onto the cells causes the overall gel contraction.

Studies on clinicopathological features of lung cancer patients with K-ras/p53 gene alterations: comparison between younger and older groups

In order to define the roles of the K-ras and p53 genes in the development of lung cancer, especially in young adults, we compared the clinicopathological features of the patients between younger (< or = 45 years, n = 47) and older (< 55 years, n = 50) groups. The gene alterations were examined by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method. The K-ras gene alterations were detected only in adenocarcinomas, and the p53 gene alterations in all histologic types of lung cancer. There were no significant differences in the frequency of both K-ras and p53 gene alterations between the younger and older groups (9 vs. 11%, 36 vs. 32%). In the younger group, but not in the older one, the percentage for smokers was significantly higher in the p53 gene alteration-positive group than for the negative group (65 vs. 30%). As to the prognosis, there were no significant differences between the p53 gene alteration-positive and -negative cases in both the younger and older groups as well as in all subjects, while a tendency of poorer prognosis was observed in K-ras gene alteration-positive cases than for the -negative ones with adenocarcinomas. These results suggest that (1) the K-ras and p53 gene alterations would have no special roles in terms of the lung carcinogenesis in young adults; (2) a positive relationship between smoking and p53 gene alteration would exist in young adults with lung cancer, and (3) K-ras gene alteration would become a prognostic factor in lung cancer.

[Studies on periodontal pathogenic proteinases from Porphyromonas gingivalis and host cells]

Progressive periodontal disease is characterized by acute progressive lesions of gingival connective tissues, excessive leukocyte infiltration, and occurrence of a characteristic microflora. A variety of proteolytic enzymes derived from oral bacteria and host cells are found in gingival crevices and thought to play an important role in the onset and development of progressive periodontal disease. The anaerobic bacterium Porphyromonas gingivalis has been implicated in the etiology of the disease. Recently, we have purified a novel arginine-specific cysteine proteinase, termed "argingipain", from the culture supernatant of the organism. The enzyme was shown to have two important abilities related to the virulence of the organism. One is direct association with periodontal tissue breakdown through its abilities to degrade physiologically important proteins such as human collagens (type I and IV) and to evade inactivation by internal protease inhibitors. The other is associated with disruption of the normal host defense mechanisms through its abilities to degrade immunoglobulins and to inhibit the bactericidal activity of polymorphonuclear leukocytes. The virulence of argingipain was further substantiated by disruption of argingipain-encoding genes on the chromosome by use of suicide plasmid systems. On the other hand, we have studied roles of host cell-derived proteinases in the periodontal tissue breakdown. Levels of lysosomal proteinases such as cathepsins B, H, L, G and medullasin were determined in gingival crevicular fluid from periodontitis patients and experimental gingivitis subjects by activity measurement and sensitive immunoassay. The results suggested that all of these enzymes would be involved in the development of both gingivitis and periodontitis.

Observer performance in the assessment of contract enhanced CT: effects of contrast medium and grey scale window on detection of defects in a simulated peripheral rim border

The image contrast of X-ray CT systems depends on the properties of the imaging system, the number of grey scales used in the digital sampling process, and the addition or otherwise of a contrast medium. The effect of contrast medium is often emphasized in the peripheral rim of pathologic masses. In this study, a special hexagonal test object made of acrylic phosphate and a cylindrical container were employed. When the contrast medium IOPAMIRON 300 was used to fill the space between the test object and its cylindrical container, a contrast-enhanced peripheral rim with or without signal of defect was observed. Visual perceptibility was examined from the signals resulting from varying contrast by use of contrast medium and adjusting the grey scale by image processing. Threshold contrast influenced by window width was recorded in each image contrast, different ranges of window width was recorded in each instance using statistical analyses. While window width was inversely proportional to image contrast, different ranges of window width and image contrast provided better visual perceptibility for each concentration of the contrast medium. The range of window width for obtaining the best visual perceptibility was determined for a contrast-enhanced image.

Overexpression of apolipoprotein E prevents development of diabetic hyperlipidemia in transgenic mice

To determine the role of apolipoprotein E (apoE) in diabetic hyperlipidemia, we induced diabetes in transgenic mice overexpressing apoE by intravenous injection of streptozotocin (STZ) and examined plasma lipoprotein metabolism in these mice. In STZ-induced diabetic mice, blood glucose levels were > 19 mmol/l (350 mg/dl) and plasma insulin levels were reduced to < 5 pmol/l (1 microU/ml). The diabetic nontransgenic mice developed hypercholesterolemia (plasma total cholesterol level: 4.55 +/- 1.32 vs. 1.97 +/- 0.13 mmol/l [176 +/- 51 vs. 76 +/- 5 mg/dl]) and hypertriglyceridemia (plasma triglyceride level: 0.82 +/- 0.29 vx. 0.42 +/- 0.11 mmol/l [73 +/- 26 vs. 37 +/- 10 mg/dl]) compared with values before induction of diabetes. In the diabetic nontransgenic mice, enhanced intestinal acylCoA:cholesterol acyltransferase activity was demonstrated, a factor that may contribute to the development of diabetic hyperlipidemia. Induction of apoE remarkably reduced the development of hyperlipidemia in diabetic transgenic mice compared with diabetic nontransgenic mice (plasma cholesterol level: 4.55 +/- 1.32 vs. 3.31 +/- 0.47 mmol/l [176 +/- 51 vs. 128 +/- 18 mg/dl], P < 0.01, and plasma triglyceride level: 0.82 +/- 0.29 vs. 0.17 +/- 0.11 mmol/l [73 +/- 26 vs. 15 +/- 10 mg/dl], P < 0.01). Plasma lipoprotein analysis by gel filtration chromatography showed that the reduction of plasma cholesterol and triglyceride levels was due to the disappearance of lipoproteins containing apoB. In these studies, we demonstrated the usefulness of STZ-induced diabetes in mice as an animal model for diabetic hyperlipidemia and demonstrated that endogenous induction of apoE in transgenic mice improved diabetic hyperlipidemia.

[Inhibitory effect of histamine-added mouse gamma-globulin on eosinophil accumulation induced by allergen in BALB/c mice]

Histamine-added human gamma-globulin (HG) has been clinically used as an anti-allergic drug for asthma, allergic rhinitis and atopic dermatitis. Retrospective analysis of clinical data have indicated that s.c. administration with HG not only improves clinical symptoms but also suppresses the number of eosinophils of nasal secretion or peripheral blood in allergic patients. Thus, the possibility was explored that HG may actively suppress eosinophil accumulation in allergic inflammation. The eosinophil accumulation in peritoneal cavity was induced by i.p. injection with ragweed pollen extract in BALB/c mice which had been repeatedly sensitized with the allergen for three weeks. Histamine-added mouse gamma-globulin (Mouse HG) at 150 mg/kg/day markedly inhibited the allergen-induced eosinophil accumulation when administered s.c. two times a week for three weeks. The inhibitory effect was almost the same as that of cyclosporin A at 100 mg/kg/day. Interestingly, equivalent dose of histamine or mouse gamma-globulin alone had no inhibitory effect in the same system. These results suggest that HG suppresses chronic allergic inflammation through the inhibition of eosinophil accumulation.

Mutations of the p53 and ras genes in childhood t(1;19)-acute lymphoblastic leukemia

We have investigated the alterations of p53 and ras genes including H-, K-, and N-ras genes in 22 acute lymphoblastic leukemia (ALL) cases and five cell lines carrying t(1;19) by use of polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis and direct sequencing. The mutations of the p53 gene were found in 2 of 20 t(1;19)-ALL cases at diagnosis (10%), all of 4 cases at relapse (100%), and 4 of the 5 cell lines (80%). Four of the five patients who died had missense mutations at codons 49, 177, 179, and 248. In cases examined sequentially, one had the same point mutation at codon 179 at both diagnosis and relapse, and another had the same p53 gene mutation at codon 240 both in leukemic cells at relapse and in a cell line derived at that time. The other case had no mutation at diagnosis but had the mutation at codon 177 at relapse and cell lines derived from blast cells at diagnosis, suggesting that a small number of leukemic cells with the p53 gene mutation at diagnosis might have escaped PCR-SSCP analysis. In cell lines, SCMC-L9 had three point mutations in the p53 gene at codons 175, 248, and 358, whereas SCMC-L10 had frame shift at codons 209-211. One case had a rare polymorphism at codon 11. We found only one mutation of the N-ras gene that was a 2-bp substitution of GGT(Gly) to GTC(Val) at codon 13 among 22 t(1;19)-ALL cases and five cell lines. This case showed no mutation of the p53 gene and has had a good course. These results suggest that in t(1;19)-ALL, mutations of the p53 and ras genes are infrequent at diagnosis and that p53 gene alterations may be associated with relapse phase or progression of t(1;19)-ALL.

Thrombomodulin inhibits intrahepatic spread in human hepatocellular carcinoma

Thrombomodulin (TM) converts thrombin from procoagulant into anticoagulant protein to activate protein C. Thrombin also plays an important role in the metastatic process of cancer cells. We performed an immunohistochemical and clinicopathological study of TM in 141 cases with resected hepatocellular carcinoma (HCC) measuring less than 6 cm in diameter. Twenty-five specimens (17.73%) stained positive for TM. TM was found in the cytoplasm and surface of cancer cells. The clinicopathological findings according to the positive of TM are examined in HCC. The preoperative plasma TM level of the patients with tissue that stained positive for TM was significantly higher than that of the patients with negative results; for the postoperative TM level, there were no differences between them. In addition, the frequencies of intrahepatic metastasis, tumor thrombus in the portal vein, and capsular infiltration were significantly lower in patients whose tissue stained positive for TM than in patients whose tissue stained negative for TM. The recurrence freedom rate was significantly higher in patients whose tissue stained positive for TM than patients whose tissue stained negative for TM. Thus, TM-producing HCC shows a slow intrahepatic spread. Therefore, these findings suggest that TM may inhibit the adhesion of tumor cells to the portal vein because of anticoagulant activity and thus prevent the spread of intrahepatic metastasis.

Structure of the most superficial layer of articular cartilage

We studied the most superficial layer of macroscopically normal articular cartilage obtained from human femoral heads, using polarising microscopy and SEM. The most superficial layer, 4 to 8 microns thick, was acellular consisting of collagen fibrils. This layer could be peeled away as a thin film, with no broken collagen fibrils on its inferior surface or on the surface of subjacent cartilage layers. The orientation and diameter of collagen fibrils were different on these two surfaces. Our findings suggest that the most superficial layer is an independent one which is only loosely connected to the fibrous structure in the layer deep to it.

[Clinical evaluation of 99mTc-MAG3 as a radiotracer to assess the function of transplanted kidney: comparison with 123I-OIH]

99mTc-MAG3 (mercaptacetyl glycilglycilglycine) is a newly developed radiopharmaceutical for the functional imaging of kidneys. We evaluated the clinical usefulness of 99mTc-MAG3 in 12 cases (7 men and 5 women, aged from 18 to 57 years old) with transplanted kidney, and compared it with 123I-OIH (o-iodohippurate). Immediately after bolus injection of 300 MBq of 99mTc-MAG3, first pass images (1 frame/3 sec for 1 min) and dynamic renal images (1 frame/60 sec for 30 min) were recorded. In 10 of 12 cases, the same examination was carried out using 37 MBq of 123I-OIH within 2 weeks. Because of its larger dose and suitable gamma-ray energy, 99mTc-MAG3 provided much better images than 123I-OIH, particulary among first pass images. Effective renal plasma flow (ERPF) calculated from the clearance of 99mTc-MAG3 was less (about 70%) than that of 123I-OIH, however, a strong correlation (r = 0.98, p < 0.001) was observed between the ERPF values of the two radiotracers. No adverse effects were caused by 99mTc-MAG3. Our data suggested that 99mTc-MAG3 was a promising radiopharmaceutical with which to evaluate regional dynamic renal function.

[Jacksonian seizure model induced by a kainic acid microinjection into unilateral sensori-motor cortex]

Kainic acid microinjection into unilateral sensori-motor cortex induced focal seizure status and secondarily generalized seizure status for about 4 hours. After these seizure status, focal myoclonic jerkings were induced for about 2 days. EEG demonstrated generalized synchronous periodic spikes with these myoclonic jerkings. This phenomenon was very similar to those symptoms of epilepsia partialis continua in man. During focal seizure status, autoradiographic study with 14C-deoxyglucose demonstrated increased local cerebral glucose utilizations in the injected site of the sensori-motor cortex, ipsilateral caudate nucleus, globus pallidus, substantia nigra and thalamic nuclei. The result suggested that subcortical pathways played an important roles in the seizure propagation from the cortical epileptogenic focus.

Hereditary ceruloplasmin deficiency with hemosiderosis: a clinicopathological study of a Japanese family

A hereditary ceruloplasmin deficiency associated with severe iron deposition in visceral organ and brain tissues found on histopathological examination at autopsy is discussed. Three siblings of consanguineous Japanese parents were studied. Their clinical symptoms were progressive dementia, extrapyramidal disorders, cerebellar ataxia, and diabetes mellitus, all of which appeared when they were between 30 and 50 years old. All had serum ceruloplasmin deficiencies and increased serum ferritin concentrations. The dentate nucleus, thalamus, putamen, caudate nucleus, and liver of each one showed low signal intensities on T1- and T2-weighted magnetic resonance images. Examination of the central nervous system revealed severe destruction of the basal ganglia and dentate nucleus, with considerable iron deposition in neuronal and glial cells, whereas the cerebral cortex showed mild iron deposition in glial cells without neuronal involvement. An electron microscopic study with energy-dispersive x-ray analysis showed iron depositions in the hepatocytes, of both the neural and glial cells of the brain. We consider this a new disease entity because of the primary ceruloplasmin deficiency.

Structure of the most superficial layer of articular cartilage

We studied the most superficial layer of macroscopically normal articular cartilage obtained from human femoral heads, using polarising microscopy and SEM. The most superficial layer, 4 to 8 microns thick, was acellular consisting of collagen fibrils. This layer could be peeled away as a thin film, with no broken collagen fibrils on its inferior surface or on the surface of subjacent cartilage layers. The orientation and diameter of collagen fibrils were different on these two surfaces. Our findings suggest that the most superficial layer is an independent one which is only loosely connected to the fibrous structure in the layer deep to it.

Effects of translation initiation factor eIF-5A on the functioning of human T-cell leukemia virus type I Rex and human immunodeficiency virus Rev inhibited trans dominantly by a Rex mutant deficient in RNA binding

The viral transactivator proteins Rex and Rev are necessary for the expression of structural proteins of human T-cell leukemia virus type I and human immunodeficiency virus type 1, respectively. Although the interaction of Rex/Rev with a cellular cofactor(s) has been thought to be required for Rex/Rev action, there is no suitable system to search for the cofactor(s) in mammalian cells. We found that a Rex mutant, TAgRex, which contains a simian virus 40 nuclear localization signal in place of the N-terminal 19 amino acids of Rex, could dominantly inhibit wild-type Rex/Rev functions. The inhibition did not require either Rev response element/Rex response element binding or the oligomerization ability of the mutant, but it did require a region around amino acid 90 of the Rex protein, suggesting that TAgRex sequestered the cellular cofactor. Complementation with the eukaryotic translation initiation factor 5A (eIF-5A) in this system could restore the impaired Rex function. These results indicate that eIF-5A is the cofactor indispensable for Rex function. Additionally, by using a two-hybrid system, the homo-oligomer formation of Rex was found to be mediated by the region around amino acid 90 in addition to Tyr-64 and Trp-65 of Rex protein. Thus, eIF-5A may play a part in the formation of the Rex homo-oligomer.