Proficiency testing with uncertainty evaluation for measuring activities per unit mass of 134Cs and 137Cs in brown rice in Japan

In Japan, we conducted proficiency testing of activity measurement by using high-purity germanium detectors for ¹³⁴Cs and ¹³⁷Cs in brown rice grains. Among 176 reported results, 86 % (for ¹³⁴Cs) and 93 % (for ¹³⁷Cs) of the results satisfied |E_n| ≦ 1. However, 58 reports for ¹³⁴Cs and 51 reports for ¹³⁷Cs had some failures in their evaluations of uncertainties. The proficiency testing was effective to improve the ability of uncertainty evaluation.

Arthroscopic decompression with indigo carmine for treating paralabral cysts in the shoulder

Paralabral cysts in the shoulder are a relatively rare pathology. It is sometimes difficult to detect the location of a paralabral cyst in the shoulder using arthroscopy, and it can be difficult to confirm sufficient decompression by arthroscopy. We describe the case of a 64-year-old woman who underwent arthroscopic decompression for a paralabral cyst in the shoulder. Indigo carmine was injected into the cyst under ultrasonography guidance just before the operation. The leakage point of indigo carmine was detected using arthroscopy. Arthroscopic decompression was performed until the indigo carmine was completely discharged. Her shoulder pain, limited range of motion, and muscle weakness during abduction and external rotation improved postoperatively. Magnetic resonance imaging confirmed the disappearance of the cyst. Arthroscopic decompression using an ultrasonography-guided injection of indigo carmine is a useful treatment for a paralabral cyst in the shoulder.

Clinical application of radial magnetic resonance imaging for evaluation of rotator cuff tear

BACKGROUND

Magnetic resonance imaging is useful for evaluating the rotator cuff, but some tendinous insertions cannot be assessed using oblique sagittal, oblique coronal, and axial magnetic resonance (MR) images because of the presence of the partial volume effect.

HYPOTHESIS

The purpose of this study was to determine whether radial-slice MR images could reveal normal rotator cuff insertions and rotator cuff tears more clearly than conventional MR images.

PATIENTS AND METHODS

The study included 18 subjects with normal rotator cuffs and 30 with rotator cuff tears. MR images of rotator cuff insertions sliced into radial, oblique coronal, and axial sections were obtained. The extent to which normal rotator cuff insertions and rotator cuff tears were visualized in each of the three MR images was evaluated.

RESULTS

The top to posterior portions of the rotator cuff insertions from 0° to 120° could be visualized in the radial MR images. In comparison, the posterior portions of the rotator cuff insertions could not be visualized around 45° in both the oblique coronal and axial MR images.

DISCUSSION

These findings demonstrate that radial MR images are superior to the oblique coronal and axial MR images regarding their ability to accurately visualize rotator cuff insertions. Radial MR images also revealed greater detail around 45° in the posterior area of the rotator cuff tears than the oblique coronal and axial MR images. Radial MR images are particularly useful for visualizing clinically important posterosuperior rotator cuff tears.

LEVEL OF EVIDENCE

Level III - Diagnostic study.

Swimming behavior of larval Medaka fish under microgravity

Fish exhibit looping and rolling behaviors when subjected to short periods of microgravity during parabolic flight. Strain-differences in the behavioral response of adult Medaka fish (Oryzias latipes) were reported previously, however, there have been few studies of larval fish behavior under microgravity. In the present study, we investigated whether microgravity affects the swimming behavior of larvae at various ages (0 to 20 days after hatching), using different strains: HNI-II, HO5, ha strain, and variety of different strains (variety). The preliminary experiments were done in the ground laboratory: the development of eyesight was examined using optokinetic response for the different strains. The visual acuity of larvae improved drastically during 20 days after hatching. Strain differences of response were noted for the development of their visual acuity. In microgravity, the results were significantly different from those of adult Medaka. The larval fish appeared to maintain their orientation, except that a few of them exhibited looping and rolling behavior. Further, most larvae swam normally with their backs turning toward the light source (dorsal light response, DLR), and the rest of them stayed with their abdomen touching the surface of the container (ventral substrate response, VSR). For larval stages, strain-differences and age-differences in behavior were observed, but less pronounced than with adult fish under microgravity. Our observations suggest that adaptability of larval fish to the gravitational change and the mechanism of their postural control in microgravity are more variable than in adult fish.

Elongation factor 1beta is an actin-binding protein

A 17 kDa polypeptide found in association with actin in cellular extracts of Dictyostelium discoideum was identified as a proteolytic fragment of eEF1beta. Antibody elicited against the 17 kDa protein reacted with a single 29 kDa polypeptide in Dictyostelium, indicating that the 17 kDa peptide arises from degradation of a larger precursor. The cDNA isolated from a Dictyostelium library using this antibody as a probe encodes Dictyostelium elongation factor 1beta. Amino acid degradation of the 17 kDa protein fragment confirmed the identity of the protein as eEF1beta. Direct interaction of eEF1beta with actin in vitro was further demonstrated in mixtures of actin with the 17 kDa protein fragment of Dictyostelium eEF1beta, recombinant preparations of Dictyostelium eEF1beta expressed in Escherichia coli, and the intact eEF1betagamma complex purified from wheat germ. Localization of eEF1beta in Dictyostelium by immunofluorescence microscopy reveals both diffuse cytoplasmic staining, and some concentration in the cortical and hyaline cytoplasm. The results support the existence of physical and functional interactions of the translation apparatus with the cytoskeleton, and suggest that eEF1beta may function in a dual role both to promote the elongation phase of protein synthesis, and to interact with cytoplasmic actin.

Clinical features of fulminant hepatitis in Nagasaki Prefecture, Japan

OBJECTIVE

Fulminant hepatitis is a rare but fatal disease. In the present study, we examined the changes in etiology and prognosis of fulminant hepatitis in Nagasaki Prefecture, Japan between 1980 to 1999.

METHODS

Eighty-one patients with fulminant hepatitis admitted to our hospitals from 1980 to 1999 were examined with respect to the etiology and prognosis.

RESULTS

Fulminant hepatitis was due to hepatitis A virus in 2 (12%) cases, hepatitis B virus in 18 (22%) cases, unknown etiology in 50 (62%) cases, and drug-induced in 11(14%) cases. The number of cases in the first half of the study (1980-1989) was 47 and that of the latter half (1990-1999) was 34 cases. The incidence of fulminant hepatitis type B also decreased from 14 cases (30%) to 4 cases (12%) during these periods. The overall survival rate of fulminant hepatitis was 32%; it was equal in fulminant hepatitis type B, fulminant hepatitis of unknown etiology and fulminant drug-induced hepatitis. The survival rate of fulminant hepatitis type A was 100%, though only two cases were identified. Retrospectively, the survival rate in patients with a pre-encephalopathy period of < or = 10 days and aged < or = 39 years was significantly higher than in patients > or = 40 years of age (p<0.01). There was no difference between the two age groups when pre-encephalopathy period was > or = 11 days.

CONCLUSIONS

The incidence of fulminant hepatitis especially that of fulminant hepatitis type B in Nagasaki Prefecture has decreased in recent years. The survival rate is significantly higher in younger patients with a short pre-encephalopathy period.

Re-analysis of clinical features of 89 patients with autoimmune hepatitis using the revised scoring system proposed by the International Autoimmune Hepatitis Group

OBJECTIVE

The diagnostic criteria of autoimmune hepatitis (AIH) were recently modified by the International Autoimmune Hepatitis Group. This study was performed to assess the impact of the revised scoring system on the diagnosis of AIH.

PATIENTS AND METHODS

We re-analyzed the clinical features of 89 patients diagnosed as AIH in Nagasaki Prefecture, Japan, using the revised scoring system, and compared the scores and final diagnosis with our previously published results using the original system.

RESULTS

Of the 89 patients with AIH, 40 (45%) were classified using the new system as "definite" AIH, 41 (46%) as "probable" AIH, and 8 (9%) patients were categorized as "others". Of these, 37 (42%), 35 (39%), and 4 (4%) patients who were classified as "definite", "probable", and "others" by the original system remained in the same category by the revised system, respectively. However, 3, 4, and 6 patients were re-categorized as "definite" from "probable", "others" from "probable", and "probable" from "definite", respectively. The difference in aggregate scores between the above two systems ranged from -5 to +2. The main contributing factors to the changes in aggregate AIH score were "other autoimmune disease(s)" and "interface hepatitis without lobular involvement and bridging necrosis on liver histology". However, the main contributing factors to the demotions from "definite" to "probable" and form "probable" to "others" were those related to the characteristics of biliary diseases, i.e., antimitochondrial antibody positive, biliary changes in liver histology, and alkaline phosphatase: aspartate aminotransferase ratio between 1.5 and 3.0. Moreover, two patients who had no histological evidence of AIH were both re-categorized as "others" from "probable" AIH.

CONCLUSION

Our results indicated that the diagnosis, whether based on the revised or original system, was the same in the majority of AIH patients, but the revised scoring system excluded cases who had features suggestive of biliary diseases from "definite" AIH, and also confirmed that a diagnosis of "definite" AIH should not be made without liver histology.

Riedel's lobe of the liver evaluated by multiple imaging modalities

An 81-year-old Japanese woman visited our hospital because of abdominal discomfort. Physical examination revealed that she had an abdominal mass. A combination of ultrasonography, computed tomography, magnetic resonance imaging (MRI), and hepatic asialoglycoprotein scintigraphy was utilized to make a diagnosis. We found that she had a downward elongated hepatic lobe or Riedel's lobe which did not appear to be common in our district. The prevalence of Riedel's lobe in the Asian population has not been studied. Furthermore, this is the first report that describes the MRI and hepatic asialoglycoprotein scintigraphy features of Riedel's lobe of the liver.

Evidence of intramolecular regulation of the Dictyostelium discoideum 34 000 Da F-actin-bundling protein

Intramolecular interaction within the Ca(2+)-regulated 34 kDa actin-bundling protein from Dictyostelium discoideum was found to contribute to the regulation of its actin-binding activity. Recombinant N-terminally truncated proteins aa77-295, 124-295, and 139-295 bound actin at > or = 2:1 stoichiometry, which is 5-fold greater than the intact protein aa1-295 as assessed by cosedimentation with F-actin. These proteins also have enhanced cross-linking activity as assessed by viscometry and electron microscopy. All truncated 34 kDa proteins failed to bind (45)Ca(2+) on blots and displayed Ca(2+)-insensitive binding with actin, although most proteins possessed intact putative EF-hand Ca(2+)-binding motifs. An intramolecular interaction within the 34 kDa protein was inferred from direct demonstrations of domain-domain interaction among the truncated 34 kDa proteins both in the presence and absence of actin. The intramolecular interaction between interaction zone 1 (aa71-123) and interaction zone 2 (aa193-254) is proposed to maintain the N-terminal inhibitory region (aa1-76) in close proximity with the strong actin-binding site (aa193-254) in order to modulate the interaction of the intact protein with actin filaments.

Three actin cross-linking proteins, the 34 kDa actin-bundling protein, alpha-actinin and gelation factor (ABP-120), have both unique and redundant roles in the growth and development of Dictyostelium

The contribution of three actin cross-linking proteins, alpha-actinin (alphaA), gelation factor (ABP-120), and the 34 kDa actin-bundling protein to cellular functions has been studied in three single mutant (alphaA-, 120-, and 34-) and three double mutant (alphaA-/120-, 34-/alphaA-, 34-/120-) strains of Dictyostelium generated by homologous recombination. Strains alphaA-/120- and 34-/alphaA- exhibited a reduced rate of pinocytosis, grew to lower saturation densities, and produced small cells in shaking cultures. All strains grew normally in bacterial suspensions and on agar plates with a bacterial lawn. Slow growth under conditions of reduced temperature and increased osmolarity was observed in single mutants 34- and alphaA-, respectively, as well as in some of the double mutant strains. Motility, chemotaxis, and development were largely unaltered in 34-/alphaA- and 34-/120- cells. However, 34-/alphaA- cells showed enhanced aggregation when starved in suspension. Moreover, morphogenesis was impaired in both double mutant strains and fruiting bodies of aberrant morphology were observed. These defects were reverted by re-expression of one of the lacking cross-linking proteins. The additive and synthetic phenotypes of these mutations indicate that actin cross-linking proteins serve both unique and overlapping functions in the actin cytoskeleton.

Clinical features of 89 patients with autoimmune hepatitis in Nagasaki Prefecture, Japan

We examined the clinical characteristics of 89 patients with autoimmune hepatitis (AIH) in Nagasaki Prefecture, Japan, and assessed the usefulness of a provisional scoring system for the diagnosis of AIH proposed by the International Autoimmune Hepatitis Group in 1993. The majority of patients were middle-aged women in their fifties. All patients showed a hepatitic picture. Forty-three patients (48%) had an insidious or chronic onset, while 34 (38%) had an acute onset, and 12 (14%) had liver cirrhosis at presentation. Seventy-nine patients (89%) were positive for antinuclear antibody (ANA), and 5 (6%) were positive for antibody to the hepatitis C virus (anti-HCV). The prognosis was good, with 90% 3-year survival, and most patients responded well to treatment with corticosteroids. The international scoring system was useful for the diagnosis of AIH in most of our patients; the percentages of patients with definite and probable AIH were 48% and 47%, respectively. However, certain factors, such as negative ANA, positive antimitochondrial antibody, concurrent infection with hepatitis B or C virus, and insufficient response to treatment precluded the diagnosis of AIH in some patients. Whether these patients were indeed "true" AIH patients is not clear at present, and further investigation of such patients may be useful for a better understanding of AIH.

Three distinct F-actin binding sites in the Dictyostelium discoideum 34,000 dalton actin bundling protein

The Dictyostelium 34 kDa protein is an actin bundling protein composed of 295 amino acids. However, the region(s) of the molecule that bind actin filaments is (are) unknown. Studies of the cosedimentation of 125I-34 kDa protein and F-actin show that the 34 kDa protein binds to F-actin with positive cooperativity and Hill coefficients of 1.9 and 3.0, for filaments 4.9 microm and 0.6 microm, respectively. The Hill coefficient is larger for short filaments that are more efficiently bundled than long filaments, suggesting that one of the binding sites is used in interfilament contacts or contributes to filament orientation within the bundle. Three distinct actin binding sites were identified using a synthetic peptide, protein truncations, and a novel epitope library screening method. The ability to bind actin was assessed by 125I-F-actin overlays under denaturing and nondenaturing conditions, cosedimentation, viscometry, and pyrene-labeled actin disassembly. The three actin binding domains were identified as amino acids 1-123, 193-254, and 279-295. The 62 amino acid domain (193-254) can cosediment with F-actin. The estimated Kapp obtained by the disassembly of pyrene-labeled actin was 0.11 microM and 2.7 microM for the amino acids 1-123 and 279-295, respectively. These results identify three distinct regions of the 34 kDa protein that may contribute to the positive cooperative formation of F-actin bundles.

The structure, function, and assembly of actin filament bundles

The cellular organization, function, and molecular composition of selected biological systems with prominent actin filament bundles are reviewed. An overall picture of the great variety of functions served by actin bundles emerges from this overview. A unifying theme is that the actin cross-linking proteins are conserved throughout the eukaryotic kingdom and yet assembled in a variety of combinations to produce actin bundles of differing functions. Mechanisms of actin bundle formation in vitro are considered illustrating the variety of physical and chemical driving forces in this exceedingly complex process. Our limited knowledge regarding the formation of actin filament bundles in vivo is contrasted with the elegant biophysical studies performed in vitro but nonetheless reveals that interactions with membranes, nucleation sites, and other organizational components must contribute to formation of actin bundles in vivo.

Dictyostelium discoideum cells lacking the 34,000-dalton actin-binding protein can grow, locomote, and develop, but exhibit defects in regulation of cell structure and movement: a case of partial redundancy

Cells lacking the Dictyostelium 34,000-D actin-bundling protein, a calcium-regulated actin cross-linking protein, were created to probe the function of this polypeptide in living cells. Gene replacement vectors were constructed by inserting either the UMP synthase or hygromycin resistance cassette into cloned 4-kb genomic DNA containing sequences encoding the 34-kD protein. After transformation and growth under appropriate selection, cells lacking the protein were analyzed by PCR analyses on genomic DNA, Northern blotting, and Western blotting. Cells lacking the 34-kD protein were obtained in strains derived from AX2 and AX3. Growth, pinocytosis, morphogenesis, and expression of developmentally regulated genes is normal in cells lacking the 34-kD protein. In chemotaxis studies, 34-kD- cells were able to locomote and orient normally, but showed an increased persistence of motility. The 34-kD- cells also lost bits of cytoplasm during locomotion. The 34-kD- cells exhibited either an excessive number of long and branched filopodia, or a decrease in filopodial length and an increase in the total number of filopodia per cell depending on the strain. Reexpression of the 34-kD protein in the AX2-derived strain led to a "rescue" of the defect in the persistence of motility and of the excess numbers of long and branched filopodia, demonstrating that these defects result from the absence of the 34-kD protein. We explain the results through a model of partial functional redundancy. Numerous other actin cross-linking proteins in Dictyostelium may be able to substitute for some functions of the 34-kD protein in the 34-kD cells. The observed phenotype is presumed to result from functions that cannot be adequately supplanted by a substitution of another actin cross-linking protein. We conclude that the 34-kD actin-bundling protein is not essential for growth, but plays an important role in dynamic control of cell shape and cytoplasmic structure.

[Evaluation of endoscopic pirarubicin-Lipiodol emulsion injection therapy for gastric cancer]

To investigate the effect on gastric cancer and metastatic lymph node, an emulsion made of pirarubicin and lipiodol mixture was injected around the lesion of the gastric cancer using gastrointestinal endoscopy. At the site of emulsion injection and lymph node, the concentration of the THP Lipiodol emulsion was enough despite injection more than 7 days before. This targeting therapy for metastatic lymph nodes was considered effective.

Clinical manifestations of HBsAg and anti-HCV negative chronic liver disease in Nagasaki Prefecture, Japan

The discovery of hepatitis C virus (HCV) has enabled the diagnosis of type C chronic liver disease, which had in the past been diagnosed as part of non-A, non-B chronic liver disease. Although most cases with chronic liver disease are caused by hepatitis B virus (HBV) or HCV infection, there are still cases of non-B, non-C chronic liver disease. Forty patients with chronic liver disease, who were seronegative for hepatitis B surface antigen and antibody to HCV, were followed for a mean period of 72 months. The clinical manifestations in these patients were compared with those reported for type B and type C chronic liver disease. Of the 40 patients, 22 were diagnosed with chronic hepatitis, 14 with liver cirrhosis and 4 with hepatocellular carcinoma (HCC). Twenty-seven (67.5%) patients showed mild alanine aminotransferase activity profiles, and the natural clinical course of most patients showed a slow progression compared with that reported for type B and type C patients. The yearly incidence of HCC was 9.7% in patients with liver cirrhosis and 3.9% in chronic hepatitis. These rates were similar to those in type B or type C patients. This suggests that our population sample contained a number of patients with type B, type C or other etiologic agent(s), because 66.7% of the patients who developed HCC had some evidence of exposure to HBV or HCV. Our results suggest that more detailed and accurate tests for detecting HBV and HCV should be considered before making the diagnosis of non-B, non-C chronic liver disease, and that there is the need to reveal unknown etiologic agent(s).

Role of the Dictyostelium 30 kDa protein in actin bundle formation

We have studied the formation of bundles in mixtures of actin with the Dictyostelium 30 kDa actin-bundling protein as a function of 30 kDa protein concentration, actin concentration, and filament length. The presence of the 30 kDa protein promotes formation of filament bundles at actin concentrations and filament lengths that are not spontaneously aligned into liquid crystalline domains in the absence of the 30 kDa protein. Bundle formation in the presence of the 30 kDa protein was observed over a broad range of actin filament lengths and concentrations. Bundling was filament length dependent, and short filaments were more efficiently bundled. Bundles formed at actin concentrations as low as 2 microM. The volume fraction of the bundled portion and concentrations of actin and the 30 kDa protein in the bundled portion were measured using a sedimentation assay. Bundles have concentrations of actin and 30 kDa protein that are 10-20 and 5-20 times, respectively, greater than that of the bulk solution. Computer modeling reveals that bundling of actin by a bundling protein increases both the mean length and the polydispersity of the length distribution, factors which lower the actin concentration required for spontaneous alignment within the bundle. We propose that entropy-driven spontaneous ordering may contribute to bundle formation in two ways. Bundling of actin creates longer aggregates with a more polydisperse length distribution in which actin aligns spontaneously within the bundle at very low concentrations. In addition, bundling creates locally high concentrations of actin within these aggregates that will spontaneously align, providing an additional driving force for bundle ordering.

Risk of hepatocellular carcinoma in patients with cirrhosis in Japan. Analysis of infectious hepatitis viruses

BACKGROUND

The development of hepatocellular carcinoma (HCC) is associated closely with cirrhosis. In the present study, the cumulative risk of HCC in patients with cirrhosis was investigated.

METHODS

A total of 401 patients were registered from April 1977 and followed for a mean of 4.4 years. Of 401 patients, 255 (64%) were tested for hepatitis B surface antigen (HBsAg) and antibody (anti-) to the hepatitis C virus (HCV); 87 (34%) patients were positive for HBsAg but were negative for anti-HCV (hepatitis B virus [HBV] group), 126 (49%) were negative for HBsAg but were positive for anti-HCV (HCV group), 10 (4%) were positive for both and 32 (13%) were negative for both (non-B non-C group).

RESULTS

By the end of March 1993, HCC was diagnosed in 127 (31.6%) patients. The cumulative risk of HCC in the HCV group was slightly higher than that in HBV group (P = 0.3, 5-year risk: 36.9 versus 21.2%). In contrast, the rate was significantly lower in the non-B non-C group than in the HBV or HCV groups (P < 0.05 and P < 0.01, respectively, 5 year risk: 12.4%).

CONCLUSIONS

These results suggest that not only HBV infection but also HCV infection increase the risk for HCC in patients with cirrhosis.

Risk of hepatocellular carcinoma in patients with cirrhosis in Japan. Analysis of infectious hepatitis viruses

BACKGROUND

The development of hepatocellular carcinoma (HCC) is associated closely with cirrhosis. In the present study, the cumulative risk of HCC in patients with cirrhosis was investigated.

METHODS

A total of 401 patients were registered from April 1977 and followed for a mean of 4.4 years. Of 401 patients, 255 (64%) were tested for hepatitis B surface antigen (HBsAg) and antibody (anti-) to the hepatitis C virus (HCV); 87 (34%) patients were positive for HBsAg but were negative for anti-HCV (hepatitis B virus [HBV] group), 126 (49%) were negative for HBsAg but were positive for anti-HCV (HCV group), 10 (4%) were positive for both and 32 (13%) were negative for both (non-B non-C group).

RESULTS

By the end of March 1993, HCC was diagnosed in 127 (31.6%) patients. The cumulative risk of HCC in the HCV group was slightly higher than that in HBV group (P = 0.3, 5-year risk: 36.9 versus 21.2%). In contrast, the rate was significantly lower in the non-B non-C group than in the HBV or HCV groups (P < 0.05 and P < 0.01, respectively, 5 year risk: 12.4%).

CONCLUSIONS

These results suggest that not only HBV infection but also HCV infection increase the risk for HCC in patients with cirrhosis.

Association of the Dictyostelium 30 kDa actin bundling protein with contact regions

‘Contact regions’ are plasma membrane domains derived from areas of intercellular contact between aggregating Dictyostelium amebae (H.M. Ingalls et al. (1986). Proc. Nat. Acad. Sci. USA 83, 4779). Purified contact regions contain a prominent actin-binding protein with an M(r) of 34,000. Immunoblotting with monoclonal antibodies identifies this polypeptide as a 34,000 M(r) actin-bundling protein (known as 30 kDa protein), previously shown to be enriched in filopodia (M. Fechheimer (1987). J. Cell Biol. 104, 1539). About four times more 30 kDa protein by mass is associated with contact regions than is found in total plasma membranes isolated from aggregating cells. In agreement with these observations, immunostaining of the 30 kDa protein in aggregating cells reveals a prominent localization along the plasma membrane at sites of intercellular contact. By contrast, alpha-actinin does not appear to be significantly enriched at sites of cell to cell contact. Binding experiments using purified plasma membranes, actin and 30 kDa protein indicate that the 30 kDa protein is associated with the plasma membrane primarily through interactions with actin filaments. Calcium ions are known to decrease the interaction of actin with 30 kDa protein in solution. Surprisingly, membrane-associated complexes of actin and the 30 kDa protein are much less sensitive to dissociation by micromolar levels of free calcium ions than are complexes in solutions lacking membranes.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential localization of alpha-actinin and the 30 kD actin-bundling protein in the cleavage furrow, phagocytic cup, and contractile vacuole of Dictyostelium discoideum

Dictyostelium discoideum amoebae possess eight different actin crosslinking proteins. Immunofluorescence microscopy has been employed in this study to investigate the intracellular localization of two of these proteins, alpha-actinin and the 30 kD actin-bundling protein, to investigate whether they are redundant, or alternatively, make distinct contributions to cell structure and movement. The 30 kD protein is concentrated in the cleavage furrow of dividing cells, while enhanced staining for alpha-actinin is not apparent in this region. By contrast, alpha-actinin is concentrated around the contractile vacuole, while the 30 kD protein is not preferentially localized in the area of this organelle. Association of alpha-actinin with the contractile vacuole was confirmed by colocalization with calmodulin, a marker of this organelle. There are temporal differences in the localization of the 30 kD protein and alpha-actinin during phagocytosis. The 30 kD protein is localized in the phagocytic cup, but disassociates from phagosomes soon after internalization [Furukawa et al., 1992: Protoplasma 169: 18-27]. alpha-actinin enters the phagocytic cup after the 30 kD protein, and remains associated with the phagosome after the 30 kD protein has disassociated. These results support the hypothesis that alpha-actinin and the 30 kD protein play distinct roles in cell structure and movement in Dictyostelium.

Formation of liquid crystals from actin filaments

Actin is cross-linked by actin-binding proteins in the cytoplasm to form either isotropic or highly oriented anisotropic structures. The inherent orientation among actin filaments could influence whether an isotropic or highly oriented anisotropic structure is formed. A highly oriented state can arise spontaneously through the formation of liquid crystals as predicted by polymer theory. In this study, the ability of filamentous actin to form liquid crystalline domains was detected using the anisotropic component of scattered light and by observation of birefringence. As liquid crystalline domains formed, the intensity of the anisotropic component of scattered light increased, and birefringent macroscopic oriented domains were directly observed. The formation of liquid crystalline domains was dependent on the concentration of actin filaments and on the average filament length controlled by varying the ratio of gelsolin to actin monomers. The concentration of actin filaments required to form liquid crystalline domains increased moderately as the average length was decreased. At a fixed actin concentration, orientation among the filaments attained a maximum value at a ratio of actin to gelsolin in the range from 1500 to 2000 and decreased as the ratio was increased or decreased from this range. The results are not well explained by theoretical treatments for liquid crystal formation by monodisperse, charged worm-like chains. Differences from the theoretical predictions for formation of liquid crystals are most likely due to the polydisperse filament length of actin. This phenomenon may have important effects on the structural and rheological properties of the cytoplasm in living cells.

A 27,000-D core of the Dictyostelium 34,000-D protein retains Ca(2+)-regulated actin cross-linking but lacks bundling activity

Actin cross-linking proteins are important for formation of isotropic F-actin networks and anisotropic bundles of filaments in the cytoplasm of eucaryotic cells. A 34,000-D protein from the cellular slime mold Dictyostelium discoideum mediates formation of actin bundles in vitro, and is specifically incorporated into filopodia. The actin cross-linking activity of this protein is inhibited by the presence of micromolar calcium. A 27,000-D fragment obtained by digestion with alpha-chymotrypsin lacks the amino-terminal six amino acids and the carboxyl-terminal 7,000 D of the intact polypeptide. The 27,000-D fragment retains F-actin binding activity assessed by cosedimentation assays and by 125I-[F-actin] blot overlay technique, F-actin cross-linking activity as assessed by viscometry, and calcium binding activity. Ultrastructural analyses indicate that the 27,000-D fragment is deficient in the bundling activity characteristic of the intact 34,000-D protein. Actin filaments are aggregated into microdomains but not bundle in the presence of the 27,000-D fragment. A polarized light scattering assay was used to demonstrate that the 34,000-D protein increases the orientational correlation among F-actin filaments. The 27,000-D fragment does not increase the orientation of the actin filaments as assessed by this technique. A terminal segment(s) of the 34,000-D protein, lacking in the 27,000-D fragment, contributes significantly to the ability to cross-link actin filaments into bundles.

Inhibition of actin filament depolymerization by the Dictyostelium 30,000-D actin-bundling protein

We have studied the effect of the Dictyostelium discoideum 30,000-D actin-bundling protein on the assembly and disassembly of pyrenyl-labeled actin in vitro. The results indicate that the protein is a potent inhibitor of the rate of actin depolymerization. The inhibition is rapid, dose dependent, and is observed at both ends of the filament. There is little effect of 30-kD protein on the initial rate of elongation from F-actin seeds or on the spontaneous nucleation of actin polymerization. We could detect little or no effect on the critical concentration. The novel feature of these results is that the filament ends are free for assembly but are significantly impaired in disassembly with little change in the critical concentration at steady state. The effects appear to be largely independent of the cross-linking of actin filaments by the 30-kD protein. Actin cross-linking proteins may not only cross-link actin filaments, but may also differentially protect filaments in cells from disassembly and promote the formation of localized filament arrays with enhanced stability.

Cohort study of hepatotropic virus and human T lymphotropic virus type-I infections in an area endemic for adult T cell leukemia

We tested for antibodies to hepatitis B virus (HBV), hepatitis C virus (HCV), and human T lymphotropic virus type-I (HTLV-I) in 629 normal inhabitants of an adult T cell leukemia (ATL) endemic area and in patients with ATL, HTLV-I associated myelopathy (HAM), and hepatocellular carcinoma (HCC) from the same district. The prevalence of serological positivity for each virus was 28.0, 6.4, and 32.6%, respectively, among the 629 inhabitants. There was a positive association between the presence of anti-HCV and serological HTLV-I positive or negative status of these subjects (9.3% vs 5.0%). Conversely, there was no correlation between HBV and HTLV-I serologic prevalence. Only inhabitants positive for anti-HCV showed significantly high serum aminotransferase levels. The levels were not affected by superimposed HTLV-I infection among anti-HCV positives. Fifty three percent of HCC patients were positive for anti-HCV; 35% of whom were simultaneously positive for antibody to HTLV-I. On the other hand, only 2 ATL patients (4.2%) and 2 HAM patients (7.7%) had anti-HCV. These findings suggest that high serum aminotransferase levels are mainly caused by HCV infection and persons with HCV and HTLV-I double infections are at a high risk for the development of HCC but not ATL or HAM.

Cytoplasmic pH of Dictyostelium discoideum amebae during early development: identification of two cell subpopulations before the aggregation stage

Development of the cellular slime mold Dictyostelium discoideum is initiated by the removal of nutrients, and results in formation of a mature fruiting body composed of two cell types, the stalk and spore cells. A considerable body of evidence supports the hypothesis that cytoplasmic pH may be an essential regulator of the choice to differentiate in either the prestalk or prespore pathway. We have devised methods for measurement and analysis of intracellular pH in developing Dictyostelium amebae in order to assess directly the potential role of cytoplasmic pH in regulating the pathway of differentiation. The intracellular pH of single D. discoideum amebae during development and in intact slugs has been measured using the pH-sensitive indicator pyranine in a low light level microspectrofluorometer. We have used the ATP-mediated loading method to introduce pyranine into these cells. Cells loaded by the ATP method appear healthy, have no detectable defects in development, and exhibit a similar population distribution of intracellular pH to those loaded by sonication. The intracellular pH of populations comprised of single amebae was found to undergo a transient acidification during development resulting in a bimodal distribution of intracellular pH. The subpopulations were characterized by fitting two gaussian distributions to the data. The number of cells in the acidic intracellular pH subpopulation reached a maximum 4 h after initiation of development, and had returned to a low level by 7 h of development. In addition, a random sample of single amebae within a slug had a median intracellular pH of 7.2, nearly identical to the median pH (7.19) of similarly treated vegetative cells. No gradient of intracellular pH along the anterior to posterior axis of the slug was detected. Our data demonstrate the existence of two distinct subpopulations of cells before the aggregation stage of development in Dictyostelium, and offers support for the hypothesis that changes in intracellular pH contribute to development in D. discoideum.

Measurement of the cytoplasmic pH of Dictyostelium discoideum using a low light level microspectrofluorometer

Pyranine was employed as a sensitive pH indicator in a low light level microspectrofluorometer. The in vivo and in vitro standard curves of the 460/410-nm fluorescence excitation ratio of pyranine as a function of pH are identical. Therefore, pyranine is specifically sensitive to cytoplasmic pH in Dictyostelium. The cytoplasmic pH of single cells in a population of Dictyostelium discoideum amoebae was obtained for the first time. The median cytoplasmic pH of vegetative amoebae was 7.19. Carbonyl cyanide m-chlorophenylhydrazone, a mitochondrial uncoupler and a protonophore, lowered the median cytoplasmic pH to 6.12 when the extracellular pH was 6.1. This result is in accord with the protonophore activity of carbonyl cyanide m-chlorophenylhydrazone. Interest in the cytoplasmic pH of Dictyostelium has been greatly stimulated by the theory that cytoplasmic acidification promotes development of pre-stalk cells, while cytoplasmic alkalinization favors the pre-spore pathway (Gross, J. D., J. Bradbury, R. R. Kay, M. J. Peacey. 1983. Nature (Lond.). 303:244-245). The theory postulates that diethylstilbestrol (DES), an inducer of stalk cell differentiation and a plasma membrane proton translocating ATPase inhibitor, should cause acidification of the cytosol. Previous measurements of the effects of stalk cell inducers including DES on intracellular pH using 31P nuclear magnetic resonance measurements have failed to confirm the predictions of the theory, and have suggested that significant modification of the model may be required. Using pyranine as the pH indicator, we find that the median cytoplasmic pH in cells treated with 10 microM DES dropped from 7.19 to pH 6.02. This effect is consistent with the pharmacological action of DES and with the proposal that DES, a stalk cell inducer, should acidify the cytosol. These results provide direct support for the theory that cytoplasmic pH is an essential regulator of the developmental pathway in Dictyostelium.

Rheology of G-actin solutions

Recent reports that dilute solutions of G-actin form viscoelastic gels have been investigated using several experimental variations of three distinct physical techniques in independent laboratories. Direct measurement of storage and loss moduli were made using two rheometers of different design. Measurements of the diffusion of G-actin and of tracer particles added to G-actin solutions were carried out using dynamic light scattering and fluorescence photobleaching recovery techniques. Measurements were performed over a period of many hours, on actin solutions prepared under conditions for which anomalous gelation had been reported. All data from this investigation are consistent with the conclusion that dilute G-actin solutions behave as newtonian liquids.

Production of abnormal prothrombin (des-gamma-carboxy prothrombin) by hepatocellular carcinoma. A clinical and experimental study

We measured plasma abnormal prothrombin (des-gamma-carboxy prothrombin; DCP) levels in normal subjects and in patients with hepatocellular carcinoma and other various diseases using the enzyme-linked immunosorbent assay developed by Motohara et al. (Pediatr Res 1985; 19: 354-357). Fifty-eight percent of 52 patients with hepatocellular carcinoma had elevated DCP levels; 24 of 28 patients with advanced or moderately advanced hepatocellular carcinoma were positive. By contrast, 50 normal controls, 13 pregnant women and 10 patients with acute hepatitis had normal levels. Three of 55 patients with chronic liver disease, and 6 of 32 patients with other malignancies, showed a slight increase. Thus, increased plasma DCP appears useful for the diagnosis of hepatocellular carcinoma. To elucidate the mechanism for the increase of DCP in hepatocellular carcinoma, we cultured a human hepatoma cell line, huH-2, and measured the levels of this abnormal prothrombin in the medium. The huH-2 cells produced large amounts of DCP in the medium without added vitamin K. It increased in a cell concentration- and time-dependent fashion. These cells produced no detectable amount of DCP in the medium with added vitamin K. Thus, human hepatoma cell line huH-2 produces DCP, and its production is dependent on the amount of vitamin K available in the medium. Des-gamma-carboxy prothrombin may be a useful tumor marker for the diagnosis of hepatocellular carcinoma.

Ultrastructural study of lymphocytic interaction with hepatocytes and endothelial cells in acute non-A, non-B hepatitis

In the liver biopsy specimens of all six patients with acute non-A, non-B hepatitis, the lymphocytic interaction with hepatocytes and sinusoidal endothelial cells was observed by electron microscopic study. Lymphocytes were in a close contact with damaged hepatocytes and interrupted endothelial cells, and the microvilli on the surface of these damaged hepatocytes were degenerated and lost. These findings pointed out the possibility that the lymphocyte may play one of the important roles in hepatocytic damage and endothelial cell damage in acute non-A, non-B hepatitis.

[Significance of anti-HBc IgM in acute hepatitis and hepatitis B associated chronic liver disease]

To determine the diagnostic value of anti-HBc IgM in acute viral hepatitis or chronic liver disease B, Anti-HBc IgM was measured by a RIA and an ELISA in 32 patients with acute hepatitis (4 with type A, 15 with type B and 13 with type non A non B), 18 patients with chronic hepatitis and 19 patients with liver cirrhosis. In acute hepatitis B, anti-HBc IgM (both RIA and ELISA) was positive in 14(93%) of 15 patients and its cut-off index value was very high. However, anti-HBc IgM was always negative in one patient with typical course of type B. In 1 of 4 patients with acute hepatitis A and 2 of 13 with non A non B, anti-HBc IgM (RIA and/or ELISA) was positive. These 3 patients were positive for anti-HBs at the onset of disease, so we could not made the diagnosis of acute hepatitis B. Anti-HBc IgM was positive in 21(51%) of 37 patients with HBsAg-positive chronic liver disease by RIA and in 11 (30%) by ELISA, and its cut-off index value was relatively low. These results suggest that when adequate cut-off index value is established, anti-HBc analysis is useful for differentiating recent and current infections from remote infections.

Significance of HB virus infection in an area of Japan with high incidence of liver cirrhosis and hepatocellular carcinoma: an analysis of consecutive studies among inhabitants of Tomié-Town, Goto Islands

In an attempt to clarify the relationship of liver cirrhosis and hepatocellular carcinoma, we have carried out investigations at an area where both these diseases develop frequently. 1) We studied the incidence of HBsAg and its antibody in 3521 inhabitants of Tomié-Town in the Goto Islands; 5.5% proved to be positive for HBsAg and 22.0% positive for anti-HBs. 2) In the HBsAg-positive group, the incidence of hepatomegaly and abnormal liver function were significantly higher than those in other groups. 3) In relation to HBsAg, anti-HBs and histological abnormalities of the liver, positive HBsAg was detected in one subject with hepatocellular carcinoma associated with liver cirrhosis, six of nine with liver cirrhosis, and four of 11 with chronic hepatitis. A positive antibody was found in one subject with liver cirrhosis and four with chronic hepatitis. Thus, HB virus infections was closely associated with latent liver disease in Tomié-Town.

[The case studies on oral administration of tegafur encapsulated with slow releasing granule (SF-SP) for three rectal patients]

Three rectal cancer patients with partial response (PR) were obtained by oral administration of 800-1200 mg/day of SF-SP. One of them showed I-A grade and other I-B in Karnofsky evaluation.

Radioimmunodetection of cancer using antibodies to alpha-fetoprotein and carcinoembryonic antigen

This study reports the use of radiolabeled antibody to AFP and CEA for the detection and localization of AFP- or CEA-producing tumors. Thirty-one patients received 131I-labeled anti-AFP or anti-CEA antibodies. Photoscans were taken at 24 and 48 hours after injection of radioantibodies. In three of six patients with CEA-producing tumors, radioimmunodetection with anti-CEA antibody showed positive scans. In AFP-producing tumors, 7 of 15 patients had positive findings on immunoscintigraphy using polyclonal anti-AFP antibody, and two of nine patients had positive findings when monoclonal antibodies were used. Analysis of radioantibody in the blood after injection showed both complex and free antibody with immunoreactivity in the circulation, and smaller complexes were seen to form after administration of monoclonal antibodies.

[Evaluation of chemotherapy in hepatocellular carcinoma with liver cirrhosis]

The present paper discusses the efficacy of cancer chemotherapy in 46 patients with advanced hepatocellular carcinoma. In most of patients, Adriamycin (20-40 mg) or Mitomycin C (20 mg) was given by one shot injection via the hepatic artery and followed by serial administration of anticancer agents such as 5-fluorouracil (300-750 mg/day), Adriamycin and Toyomycin. Results were as follows: 1) The complete response was not seen. 2) The partial response (more than 50% decrease of the tumor size) was observed in 6 of 46 patients (13%) for 34 to 457 days. 3) Absence of tumor thrombi in the portal vein which was observed by hepatic angiography, CT and ultrasonography, was closely correlated in the partial response and the prolongation of survival time. 4) There were no significant differences with the therapeutic response or survival time among 3 groups (E2: tumor occupation rate (TOR) 20-40%, E3: TOR 40-60%, E4: TOR above 60%). 5) Obstinate abdominal pain and abnormal liver function remarkably were improved during the chemotherapy in 11 of 18 cases (61%), and 6 of 46 cases (13 %), respectively. 6) Major causes of death were hepatic failure (45.7%), gastrointestinal bleeding (30.4%) and intra-abdominal rupture of the tumor (14.7%). 7) As side effect, some extent of hematopoietic suppression was observed in 25% of the patients treated.