Addition of Amide Proton Transfer Imaging to FDG-PET/CT Improves Diagnostic Accuracy in Glioma Grading: A Preliminary Study Using the Continuous Net Reclassification Analysis.

BACKGROUND AND PURPOSE: Amide proton transfer imaging has been successfully applied to brain tumors, however, the relationships between amide proton transfer and other quantitative imaging values have yet to be investigated. The aim was to examine the additive value of amide proton transfer imaging alongside [18F] FDG-PET and DWI for preoperative grading of gliomas. MATERIALS AND METHODS: Forty-nine patients with newly diagnosed gliomas were included in this retrospective study. All patients had undergone MR imaging, including DWI and amide proton transfer imaging on 3T scanners, and [18F] FDG-PET. Logistic regression analyses were conducted to examine the relationship between each imaging parameter and the presence of high-grade (grade III and/or IV) glioma. These parameters included the tumor-to-normal ratio of FDG uptake, minimum ADC, mean amide proton transfer value, and their combinations. In each model, the overall discriminative power for the detection of high-grade glioma was assessed with receiver operating characteristic curve analysis. Additive information from minimum ADC and mean amide proton transfer was also evaluated by continuous net reclassification improvement. P < .05 was considered significant. RESULTS: Tumor-to-normal ratio, minimum ADC, and mean amide proton transfer demonstrated comparable diagnostic accuracy in differentiating high-grade from low-grade gliomas. When mean amide proton transfer was combined with the tumor-to-normal ratio, the continuous net reclassification improvement was 0.64 (95% CI, 0.036-1.24; P = .04) for diagnosing high-grade glioma and 0.95 (95% CI, 0.39-1.52; P = .001) for diagnosing glioblastoma. When minimum ADC was combined with the tumor-to-normal ratio, the continuous net reclassification improvement was 0.43 (95% CI, -0.17-1.04; P = .16) for diagnosing high-grade glioma, and 1.36 (95% CI, 0.79-1.92; P < .001) for diagnosing glioblastoma. CONCLUSIONS: Addition of amide proton transfer imaging to FDG-PET/CT may improve the ability to differentiate high-grade from low-grade gliomas.

Long-term outcome of 6-month maintenance chemotherapy for acute lymphoblastic leukemia in children.

In the treatment of childhood acute lymphoblastic leukemia (ALL), excess shortening of maintenance therapy resulted in high relapse rate, as shown by our previous trial, TCCSG L92-13, in which maintenance therapy was terminated at 1 year from initiation of treatment. In this study, we aimed to confirm the long-term outcome of L92-13, and to identify who can or cannot be cured by shorter duration of maintenance therapy. To obtain sentinel cytogenetics information that had been missed before, we performed genetic analysis with genomic microarray and target intron-capture sequencing from diagnostic bone marrow smear. Disease-free survival (DFS) at 10 years from the end of therapy was 66.0±2.8%. Females (n=138) had better DFS (74.6±3.7%) than males (n=142, 57.5±4.2%, P=0.002). Patients with TCF3-PBX1 (n=11) and ETV6-RUNX1 (n=16) had excellent DFS (90.9±8.7% and 93.8±6.1%, respectively), whereas high hyperdiploidy (n=23) was the most unfavorable subgroup, with 56.6±10.3% of DFS. Short duration of therapy can cure more than half of pediatric ALL, especially females, TCF3-PBX1 and ETV6-RUNX1. Our retrospective observations suggest a gender/karyotype inhomogeneity on the impact of brief therapy.

Differentiation between primary central nervous system lymphoma and glioblastoma: a comparative study of parameters derived from dynamic susceptibility contrast-enhanced perfusion-weighted MRI.

AIM: To evaluate the diagnostic performance of parameters derived from dynamic susceptibility contrast-enhanced perfusion-weighted magnetic resonance imaging, including first-pass slope ratio (FSR), which is potentially easier to derive than the other proposed parameters in this study, for differentiating primary central nervous system lymphoma (PCNSL) from glioblastoma. MATERIALS AND METHODS: Twenty-eight patients (10 PCNSLs and 18 glioblastomas) were analysed. Six perfusion parameters - corrected cerebral blood volume ratio (cCBVR), uncorrected CBV ratio (uCBVR), FSR, leakage coefficient (K2), percentage of signal-intensity recovery measured at the end of the first-pass (PSRend), and PSR measured using mean signal-intensity after the first-pass (PSRmean) - were derived from enhancing areas selected semi-automatically. Comparisons of cCBVR and uCBVR and of PSRend and PSRmean were conducted. The differences between PCNSL and glioblastoma were compared for the six parameters, and their diagnostic performance was evaluated by receiver operating characteristic curve analysis. RESULTS: For both tumours, cCBVR was significantly higher than uCBVR, and PSRend was significantly lower than PSRmean. PCNSL demonstrated lower cCBVR, uCBVR and FSR, and higher K2, PSRend and PSRmean compared with glioblastoma (p=0.0044 or less). On receiver operating characteristic curve analysis, the areas under the curve were 0.822 for cCBVR, 0.944 for uCBVR, 0.917 for FSR, 0.917 for K2, 0.933 for PSRend, and 0.894 for PSRmean. No significant difference was observed among the parameters, except cCBVR, which was significantly inferior to uCBVR. CONCLUSIONS: PCNSL can be differentiated from glioblastoma with high diagnostic value using any of the parameters, except cCBVR. FSR demonstrates high differential performance comparable to the other parameters.

One-stop shop for 3-dimensional anatomy of hepatic vasculature and bile duct with special reference to biliary image reconstruction.

BACKGROUND/AIMS: Three-dimensional CT has become an essential tool for successful hepatic surgery. Up to now, efforts have been made to simultaneously visualize hepatic vasculature and bile ducts. Herein, we introduce a new one-stop shop approach to hepatic 3D-anatomy, using a standard enhanced MDCT alone. METHODOLOGY: A 3D-reconstruction of hepatic vasculature was made using data from contrast enhanced MDCT and SYNAPSE VINCENT software. We identified bile ducts from axial 2D image, and then reconstructed the 3D image. Both hepatic vasculature and bile duct images were integrated into a single image and it was compared with the 3D image, utilized with MRCP or DIC-CT. RESULTS: The first branches of both the right and left hepatic ducts were hand-traced and visualized for all 100 cases. The second branches of these ducts were visualized in 69 cases, and only the right second branch was recognized in 52 cases. Anomalous variations of bile ducts, such as posterior branch joining into common hepatic duct, were recognized in 12 cases. These biliary tract variations were all confirmed by MRCP or DIC-CT. CONCLUSIONS: Our new one-stop shop approach using the 3D imaging technique might contribute to successful hepatectomy as well as reduce medical costs and radiation exposure by omission of MRCP and DIC-CT.

Association of polymorphisms in DNMT1, DNMT3A, DNMT3B, MTHFR and MTRR genes with global DNA methylation levels and prognosis of autoimmune thyroid disease.

To clarify the association between factors regulating DNA methylation and the prognosis of autoimmune thyroid diseases (AITDs), we genotyped single nucleotide polymorphisms in genes encoding DNA methyltransferase 1 (DNMT1), DNMT3A, DNMT3B, methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR), which are enzymes essential for DNA methylation. Subjects for this study included 125 patients with Hashimoto's disease (HD), including 48 patients with severe HD and 49 patients with mild HD; 176 patients with Graves' disease (GD), including 79 patients with intractable GD and 47 patients with GD in remission; and 83 healthy volunteers (control subjects). The DNMT1+32204GG genotype was more frequent in patients with intractable GD than in patients with GD in remission. Genomic DNA showed significantly lower levels of global methylation in individuals with the DNMT1+32204GG genotype than in those with the AA genotype. The MTRR+66AA genotype was observed to be more frequent in patients with severe HD than in those with mild HD. The DNMT1+14395A/G, DNMT3B-579G/T, MTHFR+677C/T and +1298A/C polymorphisms were not correlated with the development or prognosis of AITD. Our study indicates that the DNMT1+32204GG genotype correlates with DNA hypomethylation and with the intractability of GD, and that the MTRR+66AA genotype may correlate with the severity of HD.

Usefulness of measuring reticulocyte hemoglobin equivalent in the management of haemodialysis patients with iron deficiency.

The evaluation of iron status in dialysis patients provides information essential to the planning of adequate recombinant human erythropoietin treatment. The cellular iron status of the patients can be determined from the recently available measurement of reticulocyte hemoglobin equivalent (RET-He). RET-He is measured on the basis of automated fluorescent flow cytometry which in the reticulocyte channel, using a polymethine dye, also measures the mean value of the forward light scatter intensity of mature red blood cells and reticulocytes. These values equate with reticulocyte hemoglobin content. In this study, to clarify the accuracy of RET-He in diagnosing iron deficiency in dialysis patients, we initially compared RET-He with such iron parameters as serum ferritin levels, transferrin saturation and content of reticulocyte hemoglobin (CHr) which has been established as indicators of functional iron deficiency. Secondly, we investigated the changes in RET-He during iron supplementation for iron-deficient patients to determine whether this marker is a prospective and reliable indicator of iron sufficiency. The participants in this study were 217 haemodialysis patients. Iron deficiency was defined as havsing a transferrin saturation (TSAT) < 20% or serum ferritin < 100 ng/ml. Conventional parameters of red blood cells and RET-He were measured by on a XE-2100 automated blood cell counter (Sysmex). CHr was measured on an ADVIA120 autoanalyser (Siemens). RET-He mean value was 32.4 pg and good correlation (r = 0.858) between RET-He and CHr is obtained in dialysis patients. Receiver operating characteristic curve analysis revealed, values of the area was 0.776 and at a cutoff value of 33.0 pg, a sensitivity of 74.3% and a specificity of 64.9%, were achieved. Iron supplements given to the patients with low TSAT or ferritin, RET-He responded within 2 weeks, and this seemed to be a potential advantage of using RET-He in the estimation of iron status. RET-He is a new parameter, equivalent value to CHr, and is easily measurable on the widely spread and popular blood cell counter and is a sensitive and specific marker of iron status in dialysis patients.

Plical resection in pre-temporal approach for basilar bifurcation aneurysms: preliminary surgical experience and cadaveric study.

OBJECT: Although a pre-temporal approach (PA) can provide a wide space for preservation of thalamoperforating atrteries in direct surgery for basilar bifurcation aneurysms (BBAs), it cannot always secure adequate proximal control. The authors described the advantages of plical resection added to PA for BBAs. METHODS: Between October 1998 and April 2000, eight consecutive patients with BBAs were treated in the neurosurgical department of Kurashiki Central Hospital. Among them, five patients received direct clipping using this method. There were four females and one male, ages ranging from 61 to 77 (mean 70.8 years). Mean aneurysmal size and distance between the in"terclinoidal line and the aneurysmal neck was 4.5 and 9.5 mm, respectively. The operative procedures consisted of the following components; 1) fronto-temporal craniotomy with translocation of orbito-zygomatico-malar bone for PA, 2) preservation of lateral branches of the superficial sylvian veins, 3) resection of plica dural folds to increase the operative field up to the oculomotor nerve (OMN). RESULTS: Complete clipping was achieved without thalamic infarction or temporal contusion in all patients. Three of the five patients suffered from transient right OMN palsy which recovered within two months after surgery. CONCLUSION: Plical resection in the pre-temporal approach might be beneficial in the surgical treatment of BBAs when proximal control seems difficult.

Microfiberscope coaxial technique in neuroendoscopic surgery.

Exploration in neuroendoscopic surgery is occasionally insufficient because of the structural limitations in endoscope. It is not easy to identify the precise position of the endoscope during an operation. We here show a coaxial technique for neuroendoscopic exploration with monitoring by means of a microfiberscope. The endoscopic coaxial technique consists of two scopes. The microfiberscope has a diameter of 0.75 mm, flexible body and high-quality image system. We tested its ability to visualize the subject at several distances and applied this coaxial technique in neuroendoscopic surgery. The microfiberscope not only visualizes the object but also magnifies it by a distance. The scope was easy to handle with monitoring of its movement in the endoscopic view. The technique allowed us to safely explore details which are difficult to approach with an ordinary fiberscope or rigid-rod scope. The microfiberscope also adjusts to the neuronal anatomy and many clinical situations. Taken together, the microfiber coaxial technique might offer new advantages to modern neuroendoscopic surgery.

Randomized placebo-controlled trial assessing the effect of bifidobacteria-fermented milk on active ulcerative colitis.

BACKGROUND: Probiotics are efficacious for treating and maintaining remission of ulcerative colitis. AIM: To conduct a randomized placebo-controlled trial of bifidobacteria-fermented milk supplementation as a dietary adjunct in treating active ulcerative colitis. METHODS: Twenty patients with mild to moderate, active, ulcerative colitis randomly received 100 mL/day of bifidobacteria-fermented milk or placebo for 12 weeks with conventional treatment. RESULTS: Clinical and endoscopic activity indices and histological scores were similar in the two groups before treatment. Although improvements were significant in both groups, the clinical activity index was significantly lower in the bifidobacteria-fermented milk than in the placebo group after treatment. The post-treatment endoscopic activity index and histological score were significantly reduced in the bifidobacteria-fermented milk, but not the placebo group. Increases in faecal butyrate, propionate and short-chain fatty acid concentrations were significant in the bifidobacteria-fermented milk, but not the placebo group. No adverse effects were observed in either group. CONCLUSION: Supplementation with this bifidobacteria-fermented milk product is safe and more effective than conventional treatment alone, suggesting possible beneficial effects in managing active ulcerative colitis. This is a pilot study and further larger studies are required to confirm the result these preliminary results.

Huge IgD plasmacytoma in the abdomen presenting coagulation necrosis.

A 65-year-old Japanese woman was diagnosed in 1996 with a pathological fracture of the left femur caused by immunoglobulin D-type myeloma (IgD myeloma). She responded well to combination chemotherapy followed by irradiation. The patient experienced renal failure and became dependent on haemodialysis. In 1999, large plasmacytomas developed in the abdomen and left humerus. The abdominal tumour appeared to induce gastroduodenal ulcers and jejunal obstruction. We initiated irradiation therapy without chemotherapy to prevent further growth of the plasmacytoma, although treatment-resistant gastroduodenal ulcers developed. Continued blood loss from the gastroduodenal ulcers resulted in a deterioration in the patient's health, which prevented successful haemodialysis. An autopsy showed that the plasmacytoma had undergone coagulation necrosis. We conclude that the use of combination chemotherapy with topical irradiation was an acceptable treatment measure against IgD plasmacytoma; irradiation without chemotherapy was the most likely cause of the coagulation necrosis seen in the plasmacytoma at autopsy.

Benefit of interferon therapy in hepatocellular carcinoma prevention for individual patients with chronic hepatitis C.

BACKGROUND: An increase in the incidence of hepatocellular carcinoma (HCC) in Japan since the 1980s suggests an imminent outbreak in other countries where viral spread occurred more recently. Interferon therapy for chronic hepatitis C, in general, has been shown to prevent HCC. AIMS: To determine the scale of benefit in individual patients. SUBJECTS: Histologically proven chronic hepatitis C patients in the Inhibition of Hepatocarcinogenesis by Interferon Therapy (IHIT) cohort (Ann Intern Med 1999;131:174), as updated in March 2003. METHODS: The lifetime risk for HCC was calculated based on HCC incidence rates, stratified by sex, age, fibrosis stage, and outcome of interferon therapy. The gain in HCC free survival was defined as the difference between expected HCC free survival with sustained virological response and that without. RESULTS: The gain in HCC free survival was greater when a patient was younger and fibrosis was more advanced. For example, a 30 year old male with F3 fibrosis gained 12.4 years by attaining sustained response while a patient with F1 fibrosis older than 60 years gained less than one year. For a treatment protocol with a given sustained response rate, prior estimation of the gain can be obtained by multiplying the calculated HCC free survival for responders by the response rate. CONCLUSIONS: The gain in HCC free survival may serve as an indicator of the benefit of interferon therapy in terms of HCC prevention and be useful in the consideration of indication and selection of treatment protocol for individual patients.

Ectopically expressed PDX-1 in liver initiates endocrine and exocrine pancreas differentiation but causes dysmorphogenesis.

To date, the potency of pancreatic and duodenal homeobox gene 1 (PDX-1) in inducing differentiation into insulin-producing cells has been demonstrated in some cells and tissues. In order to carry out efficient screening of somatic tissues and cells that can transdifferentiate into beta-cell-like cells in response to PDX-1, we generated CAG-CAT-PDX1 transgenic mice carrying a transgene cassette composed of the chicken beta-actin gene (CAG) promoter and a floxed stuffer DNA sequence (CAT) linked to PDX-1 cDNA. When the mice were crossed with Alb-Cre mice, which express the Cre recombinase driven by the rat albumin gene promoter, PDX-1 was expressed in more than 50% of hepatocytes and cholangiocytes. The PDX-1 (+) livers expressed a variety of endocrine hormone genes such as insulin, glucagon, somatostatin, and pancreatic polypeptide. In addition, they expressed exocrine genes such as elastase-1 and chymotrypsinogen 1B. However, the mice exhibited marked jaundice due to conjugated hyperbilirubinemia, and the liver tissue displayed abnormal lobe structures and multiple cystic lesions. Thus, the in vivo ectopic expression of PDX-1 in albumin-producing cells was able to initiate but not complete the differentiation of liver cells into pancreatic cells. The conditional PDX-1 transgenic mouse system developed in this study appeared to be useful for efficient screening of PDX-1 responsive somatic tissues and cells.

High frequency of antibiotic-associated diarrhea due to toxin A-negative, toxin B-positive Clostridium difficile in a hospital in Japan and risk factors for infection.

Patients hospitalized in a hospital with a high incidence of antibiotic-associated diarrhea due to toxin A-negative, toxin B-positive (A-/B+) Clostridium difficile were retrospectively investigated to determine the clinical manifestations and risk factors for infection. Of 77 Clostridium difficile isolates obtained from 77 patients during the 1-year investigation period, 30 were A-/B+ and 47 were toxin A-positive, toxin B-positive (A+/B+). By pulsed-field gel electrophoresis analysis, 23 of the 30 A-/B+ strains were outbreak-related, suggesting nosocomial spread of a single type of bacterium, which mainly affected patients in the wards of respiratory medicine, hematology and neurology. Using regression analysis, three factors were found to be associated with infection by A-/B+ isolates: (i) exposure to antineoplastic agents ( P=0.01, odds ratio [OR]=5.1), (ii) the use of nasal feeding tubes ( P=0.008, OR=5.2), and (iii) assignment to a certain internal medicine ward ( P=0.05, OR=3.0). Between patients with Clostridium difficile-associated diarrhea caused by A-/B+ strains and those with A+/B+ strains, no statistically significant difference was found in body temperature, serum concentration of C-reactive protein, leukocyte count in whole blood, frequency of diarrhea, or type of underlying disease. These results indicate that A-/B+ strains of Clostridium difficile can cause intestinal infection in humans and they spread nosocomially in the same manner as A+/B+ strains.

Prevalence of Helicobacter pylori in NSAID users with gastric ulcer.

OBJECTIVE: Regarding the interaction of Helicobacter pylori and non-steroidal anti-inflammatory drugs (NSAIDs), we cannot accept unanimous conclusions in inducing gastric ulcer. We therefore evaluated the role of Helicobacter pylori and NSAIDs in inducing gastric ulcer. METHODS: Dyspeptic patients receiving NSAIDs underwent endoscopic examination. Gastric ulcer formation and H. pylori status were investigated. Biopsy specimens from the antrum and lower body of the stomach were prepared for the rapid urease test and pathological evaluation. Anti-H. pylori antibody was measured by enzyme-linked immunosorbent assay. RESULTS: Two hundred and twenty-six patients receiving NSAIDs (220 chronic and six on-demand users) underwent gastrofibrescopic examination. There were 110 patients with gastric ulcer and 111 non-ulcer patients with gastritis. The remaining five patients had neither. NSAID users with gastric ulcer showed a low prevalence of H. pylori compared with those without them [55/110 (50.0%) vs 79/111 (71.2%), P < 0.01]. The same tendency was seen when patients receiving low-dose aspirin and those with rheumatoid arthritis were analysed separately [13/29 (44.8%) vs 50/62 (80.6%), P < 0.01, and 11/33 (33.3%) vs 16/26 (61.5%), P < 0.06 with Yates' correction, respectively]. CONCLUSION: Helicobacter pylori infection appeared to be a risk factor for developing gastritis, but we found no evidence that it increases gastric ulcer formation in NSAID users with dyspepsia.

Clinicopathological features of serum TTV DNA-positive non-A-G liver diseases in Japan.

This study was undertaken to detect TTV DNA in serum samples from patients with non-A, non-B, non-C, non-E, and non-G (non-A-G) liver diseases and from blood donors, and to investigate the clinicopathological features of TTV infection including its prevalence and influence on liver disease. The study population consisted of 20 patients with non-A-G liver diseases (nine with chronic hepatitis (CH), six with liver cirrhosis (LC), and five with hepatocellular carcinoma (HCC), as well as 47 blood donors. Detection of TTV DNA was conducted with 200 &mgr;l of serum by the nested polymerase chain reaction. The detection rate of TTV DNA by subject category was CH 55.9; LC 66.7; HCC 60%; and blood donors 28%. Regarding blood biochemistry, TTV DNA-positive patients tended to show higher levels of aspartate aminotransferase and alanine aminotransferase, as well as lower levels of platelet counts. Long-term follow-up revealed that TTV DNA-positive patients exhibited characteristic, multiple peaks of alanine aminotransferase (ALT) levels. The histologic findings in the livers of TTV DNA-positive patients with CH consisted of moderate necro-inflammatory reactions. In conclusion, it is possible that the TTV genotype 1b infection caused liver injury.

[Establishment of an optimum bowel preparation method before gynecologic laparoscopic surgery].

OBJECTIVE: To establish a new method for preoperative bowel preparation that facilitates nursing care and minimizes the patient's discomfort during the clinical pathway of laparoscopic surgery. METHOD: A randomized controlled trial was conducted for the following two preparation methods. Twenty cases were assessed with Method 1 and 18 cases with Method 2. Method 1 (the conventional procedure): oral magnesium citrate is given in the afternoon of the day before surgery, followed by a glycerin enema in the night of the day before surgery and in the morning of the day of surgery. Method 2 (a new procedure): oral magnesium citrate is given in the afternoon of the day before surgery, followed by oral picosulfate in the night before the day of surgery and a bisacodyl suppository in the morning of the day of surgery. To evaluate the two methods we sent questionnaires to the surgeons (blinded to the method used), nurses, and patients. RESULTS: No statistical difference existed between the two methods in their effectiveness as a preoperative treatment. Facilitation of nursing care was significantly better in Method 2, and patients had considerably reduced discomfort with Method 2. DISCUSSION: Patients who received oral picosulfate and a bisacodyl suppository experienced much less discomfort and nursing care was easier when compared with the conventional method of administering a glycerin enema. Since an enema is disliked by young women and an effect comes out with discomfort very shortly after the administration, the degree of discomfort of patients would have become high. Picosulfate is an oral medicine and thereby the effect comes out mildly. That would be the reason why the degree of discomfort of patients was low. In the nursing care, an enema requires time for preparation and administration, while picosulfate is easy to administer, making the nursing care easier. Therefore, Method 2 was chosen as a preoperative bowel treatment for the clinical pathway. Thus, we could establish a new evidence-based method useful for the preoperative bowel preparation in the clinical pathway of laparoscopic surgery.

Nucleotide sequence of the precore/core gene and X gene of hepatitis B virus DNA in asymptomatic hepatitis B virus carriers who are negative for serum hepatitis B core antibody.

A hepatitis B virus (HBV) carrier who is positive for hepatitis B surface (HBs) antigen but negative for hepatitis B core (HBc) antibody despite persistent HBV infection, is designated as having hepatitis B virus 2 (HBV2). HBV2 is reported to be induced by mild-grade hepatitis. Patients with HBV2 have been reported in Taiwan and Senegal. In the present study, we determined the nucleotide (nt) sequence of the precore/core gene coding region and X gene region of the HBV DNA sequence in 7 subjects who were positive for HBs antigen and negative for HBc antibody. HBV DNA was detected by nested polymerase chain reaction (PCR). Nested PCR was carried out to amplify the precore/core and X open reading frames (ORFs) of HBV DNA. The second PCR products were sequenced, followed by investigation of nt homology. There were no deletions nor insertions in the nt sequence of the precore/core and X ORFs in the HBV DNA of these 7 patients, and mutations were found only sporadically in the 7 patients. Also, there were no common amino acid substitutions in the examined regions of the amino acid sequence of HBV in the 7 patients, and we could not find a common mutation in the examined regions of HBV DNA that could potentially contribute to the development of negativity for HBc antibody. Thus, it is suggested that negativity for HBc antibody in patients with HBV2 is due to an immune response abnormality in the host.

Regulatory effects of senescence marker protein 30 on the proliferation of hepatocytes.

Senescence marker protein 30 (SMP 30) is preferentially expressed in the liver. One of its remarkable functions is the protection of cells against various injuries by enhancement of membrane calcium-pump activity. We analyzed the role of SMP 30 in hepatocyte proliferation. SMP 30 expression was decreased initially, then increased along with hepatic regeneration, after carbon tetrachloride (CCl4) administration. SMP 30 expression was decreased in the necrotic phase and then gradually increased. Its increase was slightly delayed just after the mitotic phase. These results lead us to speculate that mitoses of hepatic cells induce enhanced SMP 30 expression. In contrast, administration of lead nitrate (LN) as a hepatic mitogen induced a more stable increase of SMP 30 expression. To estimate the effect of SMP 30 on cell proliferation, we evaluated hepatic mitosis in wild-type and SMP 30-deficient knockout (KO) mice after CCl4 administration. We found an increase in mitotic numbers in hepatocytes of KO mice. This result suggests that SMP 30 has a suppressive effect on cell proliferation. Suppressive activity of SMP 30 cDNA was shown in cultured hepatoblastic cells. Our results suggest that SMP 30 performs a regulatory function in liver regeneration.