Domino model for geomagnetic field reversals.

We solve the equations of motion of a one-dimensional planar Heisenberg (or Vaks-Larkin) model consisting of a system of interacting macrospins aligned along a ring. Each spin has unit length and is described by its angle with respect to the rotational axis. The orientation of the spins can vary in time due to spin-spin interaction and random forcing. We statistically describe the behavior of the sum of all spins for different parameters. The term "domino model" in the title refers to the interaction among the spins. We compare the model results with geomagnetic field reversals and dynamo simulations and find strikingly similar behavior. The aggregate of all spins keeps the same direction for a long time and, once in a while, begins flipping to change the orientation by almost 180 degrees (mimicking a geomagnetic reversal) or to move back to the original direction (mimicking an excursion). Most of the time the spins are aligned or antialigned and deviate only slightly with respect to the rotational axis (mimicking the secular variation of the geomagnetic pole with respect to the geographic pole). Reversals are fast compared to the times in between and they occur at random times, both in the model and in the case of the Earth's magnetic field.

Overexpression of p8 is inversely correlated with apoptosis in pancreatic cancer.

A recently identified gene, p8, has cell growth-promoting activity and is strongly induced in acute pancreatitis. In this study, we detected p8 and single-stranded DNA (ssDNA) for apoptosis by immunohistochemistry in human pancreatic cancer. The p8 was overexpressed (>30% per 1000 cancer cells) in 26 of 44 (59%) pancreatic cancers, and apoptosis (ssDNA-positive cells >10% per 1000 cancer cells) was recognized in 18 of 44 (41%) pancreatic cancers. There was a significant inverse correlation between the p8 overexpression and apoptosis (P < 0.05). Moreover, the expression pattern of high p8 and low ssDNA was seen significantly more often in lower age (<65 years), in moderately or poorly differentiated cancers, and in node-positive cases (P < 0.05). The p8 expression and apoptosis were not significantly correlated with survival. These results suggest that p8 overexpression is involved in antiapoptotic activity and the biological characteristics of pancreatic cancer.

Modulation of doxorubicin sensitivity by cyclosporine A in hepatocellular carcinoma cells and their doxorubicin-resistant sublines.

BACKGROUND AND AIMS: Cyclosporine A (Cys) and verapamil (Ver) sensitize multidrug-resistant (MDR) cells to various anticancer drugs by interacting with membrane glycoproteins involved in the drug efflux. In the present study, we assessed the effect of Cys on the modulation of doxorubicin (DOR) sensitivity in hepatocellular carcinoma (HCC) cell lines, and their DOR-resistant sublines. METHODS: The sensitivity to DOR and the chemosensitizing effects of Cys were assessed by using two human HCC cell lines, PLC/PRF/5 and Hep-3B, and their DOR-resistant sublines, PLC/DOR and 3B/DOR. The expression of multidrug resistance 1 (MDR1) and multidrug resistance-associated protein (MRP) mRNA in these cells were detected by using a RT-PCR. The HCC cell lines grown in individual wells of 24-well plates were incubated with DOR that were sequentially diluted in culture medium in combination with 5 micromol/L Cys for 24 h. The cell viability in each well was measured by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: The mRNA of MDR1 and that of MRP were readily detectable in the HCC cell lines by RT-PCR. When 5 micromol/L Cys was added to the culture, the 50% inhibiting concentration (IC50) of DOR was reduced from 0.93 +/- 0.29 microg/mL to 0.32 +/- 0.10 microg/mL in PLC/PRF/5, and from 0.25 +/- 0.07 microg/mL to 0.09 +/- 0.04 microg/mL in Hep-3B. Furthermore, in the presence of 5 micromol/L Cys, the IC50 of DOR was reduced from 48.63 +/- 17.04 microg/mL to 0.49 +/- 0.14 microg/mL in PLC/DOR, and from 4.60 +/- 1.22 microg/mL to 0.15 +/- 0.06 microg/mL in 3B/DOR. The amounts of PCR products of MDR1 mRNA in PLC/DOR and 3B/DOR were greater than those in PLC/PRF/5 and Hep-3B, respectively. CONCLUSIONS: In HCC, the amplification of MDR1 mRNA is probably the main mechanism underlying acquired DOR resistance. Cyclosporine is also indicated to be highly active in potentiating the anticancer activity of DOR in HCC cells and their DOR-resistant sublines.

Expression of p8 in human pancreatic cancer.

The p8 gene is a recently identified gene with mitogenic activity. p8 expression is induced in acute pancreatitis, pancreatic development, and regeneration. However, the expression of p8 in pancreatic cancer is not reported. We investigated p8 expression in 72 human pancreatic tissues, including 38 pancreatic cancers (PCs), by immunohistochemistry. p8 was overexpressed (positive cells >25% in 1,000 cells) in 71% (27 of 38) of PCs, but in only 17% (3 of 18) of chronic pancreatitis cases. There was no overexpression in mucinous cystadenoma or in normal pancreas. The p8 overexpression rate in PC was significantly higher than that in other conditions (P < 0.05). Reverse transcription-PCR analysis confirmed p8 mRNA overexpression (tumor/nontumor ratio >2) in 75% (3 of 4) of PCs. p8 was overexpressed also in human pancreatic cancer cell lines (MIA PaCa-2 and PANC-1). These results suggest that p8 is involved in the development of pancreatic cancer, reflecting its mitogenic activity.

Mild prenatal stress enhances learning performance in the non-adopted rat offspring.

The present study was designed to investigate whether mild stress during pregnancy affects offspring behaviors, including learning performance. Prenatal stress was induced by short-lasting, mild restraint stress, which had previously been shown to facilitate the morphological development of fetal brain neurons. Adult offspring whose dams had been restrained in a small cage for 30min daily from gestation day 15 to 17 showed enhanced active avoidance and radial maze learning performance. In addition, the prenatally stressed rats showed weaker emotional responses than unstressed control, as indicated by decreases both in ambulation upon initial exposure to an open field and in Fos expression in the amygdala induced by physical stress. The observed effects of prenatal stress on learning performance and emotional behavior were attenuated by foster rearing by unstressed dams. Fos expression in the hypothalamic paraventricular nucleus following physical stress and corticosterone secretion during physical and psychological stress did not differ between the prenatally stressed and unstressed control rats. From these results we suggest that mild prenatal stress facilitates learning performance in the adult offspring. The enhancement of learning performance appears to be accompanied by reduced emotionality, but not by any apparent alterations in hypothalamic-pituitary-adrenal responses. In addition, the observation of differential behaviors in the adopted and non-adopted animals supports the notion that the postnatal environment modifies the behavioral effects of prenatal stress.

Effect of herbal medicine keishi-to (TJ-45) and its components on rat pancreatic acinar cell injuries in vivo and in vitro.

BACKGROUND: In an attempt to clarify the mechanism of the effect of a herbal medicine, Saiko-keishi-to (TJ-10), which is a combination of Keishi-to (TJ-45) and Sho-saiko-to (TJ-9), we investigated the effects of these two herbal medicines and their components on pancreatic acinar cell injury models in vivo and in vitro. METHODS: Four-week-old male WBN/Kob rats were fed an MB-3 pellet diet containing herbal medicine (TJ-9, TJ-10 and TJ-45). Expressions of pancreatitis-associated protein (PAP) and manganese superoxide dismutase (Mn-SOD) were analyzed with a reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. The herbal medicines and two of their components, Keihi (Cinnamomi cortex) and Shakuyaku (Paeoniae radix alba), were tested in vitro using an arginine-treated rat pancreatic acinar AR4-2J cell injury model. The inducible nitric oxide synthase (iNOS) was assayed in in vitro experiments. RESULTS: TJ-45-treated WBN/Kob rats showed no evidence of pancreatitis whereas there were pathological changes of chronic pancreatitis in TJ-9-treated WBN/Kob rats. PAP was not expressed and Mn-SOD expression was increased in the TJ-10-, and TJ-45-treated rats. The herbal medicines and two components suppressed PAP mRNA expression and enhanced Mn-SOD and iNOS mRNA expression in arginine-treated AR4-2J cells. CONCLUSION: These results suggest that the herbal medicine TJ-45 is effective for chronic pancreatitis caused by pancreatic ischemia.

Pancreatitis-associated protein levels in pancreatic juice from patients with pancreatic diseases.

BACKGROUND: Pancreatitis-associated protein (PAP), the acute-phase protein of the pancreas, is overexpressed in acute pancreatitis. Serum PAP levels were reported to be useful as an indicator of the severity, prognosis and healing of acute pancreatitis. Although PAP was originally identified in pancreatic juice, there has been no clinical report on PAP levels in pancreatic juice. This study was conducted to determine levels of PAP in pancreatic juice (PJ-PAP) in various human pancreatic diseases. METHODS: PAP levels in endoscopically aspirated PJ were measured by enzyme-linked immunosorbent assay in 86 patients with pancreatic diseases. RESULTS: 55% of 22 patients with pancreatic cancer (PC) and 25% of 49 patients with chronic pancreatitis (CP) were positive (> 350 ng/ml) for PJ-PAP. PJ-PAP levels were significantly higher in PC than in CP, in which PJ-PAP was also significantly higher than in 15 control subjects. There was no significant correlation between PJ-PAP and serum PAP, and combination assay of serum PAP and/or PJ-PAP detected 80% of PC cases and 44% of CP cases. CONCLUSIONS: We have demonstrated that human PAP could be detected in pancreatic juice from patients with pancreatic diseases. Determination of PAP in pancreatic juice might be helpful for early detection of pancreatic injury.

Complete regression of colonic adenomas after treatment with sulindac in Gardner's syndrome: a 4-year follow-up.

A 22-year-old woman with Gardner's syndrome in whom long-term sulindac therapy, without surgical treatment, was effective in inducing complete regression of colonic adenomas is reported. One hundred milligrams of sulindac was administered twice daily after endoscopic polypectomy. Follow-up colonoscopy 6 months later revealed an encouraging regression of colonic adenomas. The tumors had disappeared after 40 months of sulindac treatment. A sustained effect was identified even after 51 months. Ten milligrams of famotidine was coadministered to prevent side effects of sulindac. Although the effect of sulindac on colorectal adenomas may be transient, this therapy may be useful for postponing prophylactic colectomy, especially for the sparse type of familial adenomatous polyposis.

Prevalence of hepatitis G virus (HGV) infection in an endemic area of hepatitis C virus (HCV) infection.

BACKGROUND/AIMS: We investigated the prevalence of hepatitis G virus infection among inhabitants of a hepatitis C virus endemic area. METHODOLOGY: Two hundred and eighty-eight inhabitants, who underwent medical examinations for health screening, were enrolled in this epidemiological study. HGV RNA and HCV RNA were detected by polymerase chain reaction. We also examined anti-HGV envelope protein (E2) antibodies in all serum samples. RESULTS: In these 288 inhabitants, we found anti-HCV antibodies (HCV-Ab) and HCV RNA in 28.5% and 17.4%, respectively. HGV RNA and anti-HGV E2 were detected in 9 (3.1%) and 16 (5.5%), respectively. One patient was positive for both HGV RNA and anti-HGV E2. The exposure rate, expressed as the percentage of people with HGV RNA and/or anti-HGV E2, was 8.3%, which was significantly lower than the incidence of positive HCV-Ab. Of the 24 patients with HGV RNA and/or anti-HGV E2, 15 (62.5%) were positive for HCV-Ab, of those HCV RNA was detected in 9 (37.5%). Further, we found a higher prevalence of HGV exposure in patients with HCV-Ab than in those without (8.3% vs. 4.4%). CONCLUSIONS: HGV infection was not identical to the epidemic hepatitis C virus infection among inhabitants of this town, suggesting that hepatitis C virus might be less infectious than hepatitis C virus.

Grain Survival in Supernova Remnants and Herbig-Haro Objects.

By using the [Fe ii] lambda8617/[O i] lambda6300 flux ratio, we demonstrate that most of the interstellar dust grains survive in shocks associated with supernova remnants and Herbig-Haro objects. The [Fe ii]/[O i] flux ratio is sensitive to the gas-phase Fe/O abundance ratio but is insensitive to the ionization state, temperature, and density of the gas. We calculate the [Fe ii]/[O i] flux ratio in shocks and compare the results with the observational data. When only 20% of iron is in the gas phase, the models reproduce the observations most successfully. This finding is in conflict with the current consensus that shocks destroy almost all the grains and that approximately 100% of metals are in the gas phase. We comment on previous works on grain destruction and discuss why grains are not destroyed in shocks.

Increase in CD95 (Fas/APO-1)-positive CD4+ and CD8+ T cells in peripheral blood derived from patients with autoimmune hepatitis or chronic hepatitis C with autoimmune phenomena.

BACKGROUND: The expressions of CD95 (Fas/APO-1) and Bcl-2 are determinants of apoptosis in normal lymphocytes, and abnormalities in their expressions might contribute to the induction of autoimmunity. In this study, we examined the expressions of CD95 and Bcl-2 on freshly isolated T and B cells from patients with autoimmune hepatitis (AIH) or chronic hepatitis C associated with autoimmune phenomena (CH-C(AI)). METHODS: The CD95 and Bcl-2 expressions within CD4+ T, CD8+ T, and CD19+ B cell subsets were analysed by two-colour flow cytometry. RESULTS: The surface expression of CD95 was significantly high in both the CD4+ T and CD8+ T cell subsets derived from the patients with AIH and those with CH-C(AI), compared with expression in patients with CH-C and normal subjects. The increase in CD95 expression was associated with the phenotypic conversion of naive CD45RO- to primed CD45RO+ CD4+ T cells. Bcl-2 was detected in the vast majority of peripheral T and B cells. There was no significant difference in the percentage of Bcl-2-positive cells in the CD4+ T cell, CD8+ T cell and CD19+ B cell subsets among the patient groups and normal subjects. CONCLUSIONS: These results indicate that an increase in CD4+ T cells expressing CD45RO and CD95 marks an important subset of AIH and CH-C(AI) patients. These expanded CD95+ CD45RO+ primed T cells most likely reflect a continuous antigen-specific or non-specific activation of T lymphocytes, and/or the persistent presence of activated lymphocytes as a consequence of abnormalities in the peripheral deletion of activated lymphocytes. These persistently activated lymphocytes might play a role in the induction of autoimmunity in AIH and CH-C(AI).

Serum levels of pancreatitis-associated protein in digestive diseases with special reference to gastrointestinal cancers.

The serum levels of pancreatitis-associated protein (PAP) were measured in 196 patients with digestive diseases and 15 healthy subjects by an enzyme-linked immunosorbent assay. The serum PAP levels were significantly elevated in the patients with gastric, colorectal, biliary tract, hepatocellular, or pancreatic cancers compared with the healthy subjects. After curative resection of the tumor, serum PAP levels were significantly decreased. The serum PAP levels were not related to clinicopathological factors except for the tumor size of pancreatic cancer. There were some cases of PAP-positive and carcinoembryonic antigen (CEA) or carbohydrate antigen (CA) 19-9 -negative gastric and colorectal cancers. The serum PAP levels were also significantly elevated in the patients with acute pancreatitis compared with those in not only the healthy subjects but also the patients with chronic pancreatitis. The peak PAP levels were significantly correlated with the severity of acute pancreatitis and reflected the clinical healing of the disease. The peak of serum PAP was significantly delayed compared with those of other pancreatic enzymes. These results suggest that the increase of serum PAP levels in patients with gastrointestinal cancers reflects an ectopic expression of PAP in cancer cells and that increased serum levels of PAP in acute pancreatitis are correlated with the disease severity and are prolonged than those of other pancreatic markers.

Mucin-producing biliary papillomatosis associated with gastrobiliary fistula.

We report a case of mucin-producing biliary papillomatosis in a 78-year-old woman. Abdominal ultrasound (US) and computed tomography (CT) showed wall thickening and dilatation of the intrahepatic bile duct (IHBD), as well as a nodular lesion, 1.2 cm in diameter, in the left branch of the IHBD. Gastric endoscopy revealed excretion of bile-containing mucin on the anterior wall of the body of the stomach. Endoscopic ultrasonography (EUS) showed gastrobiliary fistula and discharge of mucin into the stomach. Needle biopsy of the biliary tumor revealed papillary proliferation, but no malignant cells were recognized histologically. Therefore this patient was diagnosed as having mucin-producing biliary papillomatosis forming gastrobiliary fistula. She did not present with obstructive jaundice, probably because of the fistula. She is alive, without obstructive jaundice, 16 months after the diagnosis without having had surgery. This is, to our knowledge, the first reported case of biliary papillomatosis forming gastrobiliary fistula and with the patient free of obstructive jaundice.

Pancreatic cancer associated with granulocyte-colony stimulating factor production confirmed by immunohistochemistry.

We report an 83-year-old man with pancreatic body cancer of 4.5 cm in diameter. Peripheral leukocyte count was 15,700/microl and the serum concentration of granulocyte-colony stimulating factor (G-CSF) was 123 pg/ml (normal, 6.0-21.9 pg/ml) on admission. Furthermore, not only K-ras codon 12 (GGT --> GAT) but also p53 at codon 247 (CGG --> CCG) mutations were identified in the pancreatic juice aspirated endoscopically. We performed chemotherapy with two courses of 5-fluorouracil, pirarubicin hydrochloride, and mitomycin-C, resulting in no beneficial effect. After the second course the patient developed interstitial pneumonia, probably caused by anticancer drugs, and died 4 months after the tumor was detected. In the autopsy tissue, the tumor macroscopically occupied the pancreas body and was 7 x 6 x 5 cm in size. Histopathologic diagnosis of the tumor was poorly differentiated adenosquamous carcinoma. Immunohistochemical staining of the autopsy tissue showed that pancreatic cancer cells were positive for G-CSF. This is the first case report of G-CSF-positive pancreatic cancer confirmed by immunohistochemistry.

Hematologic response in patients with aplastic anemia after long-term administration of recombinant human granulocyte colony-stimulating factor and erythropoietin.

Twenty patients with aplastic anemia underwent long-term administration (10 weeks) of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in doses from 50 to 800 micrograms/m2 per day by intravenous infusion or 50 to 100 micrograms/m2 per day by subcutaneous injection and re-combinant human erythropoietin (rhEPO) in doses ranging from 2000 to 8000 IU/m2 per day by intravenous injection three times a week for at least 4 weeks. The goal was to evaluate whether therapy ameliorated pancytopenia in these patients as well as to determine its safety. All assessable patients showed a substantial increase in absolute neutrophil count, with a recovery of myeloid components (granulocyte series) in the bone marrow, after 2 to 10 weeks of treatment. An increase > 1.5 g/dL in hemoglobin (Hb) concentration was observed in 2 patients (10%). A decrease > 50% in red cell transfusion requirement was observed in 2 patients (10%). Seven patients showed recovery of neutropenia, anemia, and platelet count. In addition, there was no serious infection before or during therapy, and side effects were mild. Of the 20 patients, 3 showed a dramatic improvement in severe anemia after 10 weeks of treatment accompanying a recovery of erythroid components in the bone marrow. They no longer require red cell transfusions and have had normal Hb concentrations and normal ferrokinetics. These results indicate that long-term administration of rhG-CSF and rhEPO may benefit some patients with aplastic anemia. Further studies will be necessary to elucidate the mechanism by which rhGCSF and rhEPO stimulate hematopoiesis and improve hematologic abnormalities in these patients.

[Low-grade non-Hodgkin's lymphoma: intensive combined chemotherapy].

The efficacy of various combination chemotherapies employed for the 37 patients with low-grade non-Hodgkin's lymphoma between 1981 and 1994 was evaluated retrospectively. The overall survival at 5 years was 68%. The 5-year survival of the 27 patients achieving complete response (CR) was 87%, which was significantly higher than that of 9 patients with partial response (p = 0.0005). The CR rate of stage III and IV patients was 64% for the 22 patients treated with ACOMP-B (D), and was 38% for 8 others treated with milder chemotherapy regimens including VEPA. The 22 advanced stage patients had a 5-year survival of 88% after the treatment with ACOMP-B (D) and 69% of them remained free of disease at 5 years. In this group no relapse occurred beyond 1.6 years after treatment. These findings suggest a possible role of third generation chemotherapy in the treatment of patients with advanced-stage low-grade non-Hodgkin's lymphoma.

[Foscarnet for cytomegalovirus retinitis in a patient with acquired immunodeficiency syndrome].

A 41-year-old man with acquired immunodeficiency syndrome (AIDS) developed cytomegalovirus (CMV) retinitis. Intravenous administration of ganciclovir arrested progression of the retinitis, but it was discontinued due to side effects of severe anemia, neutropenia, and thrombocytopenia. Reactivation of CMV retinitis occurred two weeks after stopping ganciclovir, and then forscarnet was given intravenously. The response was prompt with resolution of the retinitis. There was no progression of retinitis during the treatment. The patient experienced renal dysfunction as a side effect of foscarnet, but it was reversible. As with ganciclovir, foscarnet appeared to be an effective drug for CMV retinitis associated with AIDS. Both drugs have severe adverse events: foscarnet causes renal dysfunction and ganciclovir causes myelosuppression, that necessitated discontinuation of the therapy. We suggest that alternating ganciclovir and foscarnet administration, switching to other treatment on the basis of the clinical response and side effects of the drugs, is an efficacious regimen for the treatment of CMV retinitis associated with AIDS.

[Burkitt's lymphoma diagnosed by molecular analysis of DNA from malignant cells in ascites].

A 73-year-old man was admitted with severe abdominal fullness. Physical examination suggested much ascites. Laboratory data revealed that BUN was 39 mg/dl, Cr was 2.2 mg/dl, UA was 19.7 mg/dl, and LDH was 1,569 U/l. In ascites, there were many cells with large nuclei and many vacuoles. Immunocytological characterization indicated that most of these cells were B lineage. And diagnosis of malignant lymphoma, the patient was treated with VEPA therapy. However, he soon died with acute renal failure. We examined the possibility of gene rearrangements between the c-myc and immunoglobulin genes and found that c-myc gene was rearranged at the first intron, and joined with immunoglobulin JH locus as head to head. These results suggested that the patient carried Burkitt's lymphoma of the American type.

[Seroepidemiological study on the horizontal infection of HBV in healthy students].

In a seroepidemiological study of hepatitis B virus (HBV) over 7 years from 1982 to 1988, in a fixed population of 633 healthy students (15-20 years old), it was found that one HBV carrier who had adw subtype of HBV had also become sero-positive to r subtype, suggesting the superinfection with r subtype of HBV to the carrier. Then, some serological markers of HBV were further examined in the other 10 HBsAg positive carriers in the same population, and discussed the possibility of horizontal transmission of r subtype of HBV in the population. Of the 10 HBsAg positive carriers, 5 possessed adr subtype, 2 adwr, 2 adw, respectively, and the remaining one was not tested. Four of seven r subtype of HBsAg positive carriers exhibited pre-S2Ag and HBeAg activities which were considered as infectious markers. Epidemiological survey was carried on the four carriers with special reference to the possibility of the superinfection. As a result, it is still unclear the source of the superinfection, but at least, iatrogenically accidental transmission at the time of vaccination and contact infection in everyday life in school may be unlikely to attribute to the horizontal transmission.

Beta-interferon and early stage HIV infection.

beta-Interferon (IFN-beta) was evaluated prospectively for its antiviral activities in early stage human immunodeficiency virus (HIV) infection. Ten patients with hemophilia and HIV infection [8 asymptomatic carriers (AC) and 2 AIDS-related complex (ARC)] were intravenously injected with 1 million IU of IFN-beta twice a week for 6 months. For comparison, seven patients (six AC and one ARC) with hemophilia and HIV infection were observed for the same time period without any drugs. One episode of localized herpes zoster each occurred during the trial in the IFN group and in the control group. There were no significant differences in the absolute number of CD4+ lymphocytes and ratios of CD4+/CD8+ lymphocytes between the two groups. Recipients had flu-like symptoms but no serious toxicities. No clinical and immunological benefits to patients with early stage HIV infection were observed during the 6 months of treatment.