Epidermal growth factor and 1alpha,25-dihydroxyvitamin D3 suppress lipogenesis in hamster sebaceous gland cells in vitro

We have previously reported the establishment of a culture system of hamster auricular sebocytes. Although their morphologic and biochemical properties are very similar to those of human sebocytes, the regulation of lipogenesis is not clear. Therefore, we investigated the effect of epidermal growth factor, all-trans retinoic acid, 1alpha,25-dihydroxyvitamin D3, and androgens such as testosterone and 5alpha-dihydrotestosterone on lipogenesis in cultured hamster sebocytes. Intracellular lipid droplets detected with Oil-Red-O staining were observed in 5 d cultures and increased in a time-dependent manner; 40.7% +/- 1.11% of 2 wk cultured cells tested lipid-positive by flow cytometric analysis. When the hamster sebocytes were cultured in the presence of epidermal growth factor, all-trans retinoic acid, or 1alpha,25-dihydroxyvitamin D3, the intracellular lipid droplets were diminished by all-trans retinoic acid and epidermal growth factor, and slightly by 1alpha,25-dihydroxyvitamin D3. The intracellular lipid droplets consisted mainly of triglycerides (71.8%) and, as minor components, cholesterol (18.0%), wax esters (3.6%), and free fatty acids (6.6%). Epidermal growth factor and all-trans retinoic acid decreased the intracellular accumulation of triglycerides (92.6% and 96.1% inhibition, respectively) and free fatty acids (54.3% and 62.6% inhibition, respectively) in the sebocytes. In addition, 1alpha,25-dihydroxyvitamin D3 decreased the triglyceride level (34.3% inhibition), but augmented the accumulation of wax esters (30% increase). There was no difference in the level of cholesterol as a result of these treatments, however. In contrast, 5alpha-dihydrotestosterone augmented the formation of intracellular lipid droplets along with an increase in the accumulation of triglycerides in hamster sebocytes. Our findings that regulation of lipogenesis by all-trans retinoic acid and androgen in hamster sebocytes is identical to regulation in humans suggest that hamster sebocytes are useful for the elucidation of sebaceous function at the cellular level. Furthermore, this is the first evidence that epidermal growth factor and 1alpha,25-dihydroxyvitamin D3 may act as suppressors in the regulation of lipogenesis in hamster sebocytes in vitro.

Expression of bone morphogenetic proteins in colon carcinoma with heterotopic ossification

Here we report the case of a 50-year-old woman with adenocarcinoma of the colon, showing heterotopic ossification. The patient was referred to our hospital for investigation of anemia secondary to occult gastrointestinal blood loss. By colonoscopy, an irregular polypoid mass was found in the ascending colon. A biopsy of the lesion revealed moderately to poorly differentiated adenocarcinoma with heterotopic ossification. A right hemicolectomy was done and revealed areas of heterotopic bone within the tumor, but no ossification was evident in the metastatic lesions within the mesenteric lymph nodes. The formation of heterotopic bone in gastrointestinal tumors is rare and its exact mechanism is unknown. Immunohistochemical localization of bone morphogenetic proteins (BMP), known to be primary inducers of new bone formation, was determined. BMP-5 and -6 were prominent in the cytoplasm of tumor cells, and they stained weakly in osteoblast-like cells adjacent to newly formed bone. Cytoplasmic staining for BMP-2 and -4 was weak in tumor cells, osteoblast-like cells, and stromal fibroblast cells. BMP may play an important role in heterotopic ossification in colon adenocarcinoma.

Membranoproliferative glomerulonephritis associated with hypocomplementemic urticarial vasculitis after complete remission of membranous nephropathy

A 49-year-old-man developed proteinuria in 1978. He was diagnosed as having membranous nephropathy by renal biopsy and was treated with prednisolone. The proteinuria disappeared completely and the treatment was stopped. In 1995, after complete remission, he developed nephrotic syndrome with chronic urticaria and hypocomplementemia. Renal biopsy revealed membranoproliferative glomerulonephritis (type I) and skin biopsy showed leukocytoclastic vasculitis, which was compatible with hypocomplementemic vasculitis syndrome. Steroid therapy was very effective.

[A case of silicosis with MPO-ANCA-associated glomerulonephritis and alveolar hemorrhage]

A 63-year-old man was referred to our hospital for rapid deterioration of his renal function. He had worked as a metal founder for more than 40 years, and had been diagnosed as having silicosis. Laboratory data on admission showed severe anemia, thrombocytopenia, and end-stage renal failure (BUN 88.8 mg/dl, serum creatinine 9.0 mg/dl). Myeloperoxidase anti-neutrophil cytoplasmic antibody(MPO-ANCA) was also detected in his sera. On the next day after admission, he complained of sudden dyspnea and hemoptysis. Mechanical ventilation with pure oxygen was insufficient to improve hypoxia without concomitant use of percutaneous cardio-pulmonary support(PCPS) and continuous hemofiltration(CHF). We diagnosed his condition as MPO-ANCA-associated rapidly progressive glomerulonephritis with diffuse alveolar hemorrhage. Treatment with plasmapheresis, pulse methylprednisolone and pulse cyclophosphamide effectively improved his hemoptysis as well as chest X-ray findings and blood gas analysis. However on his later clinical course, he was complicated with superimposed complex infection and passed away. Autopsy findings showed crescentic glomerulonephritis in the kidneys and silica nodules in the lungs. Recently it has been postulated that some relationship exists between ANCA-associated(especially MPO-ANCA-associated) glomerulonephritis and silica exposure. The reported cases of glomerulonephritis in the patients with silica exposure showed a rapidly progressive clinical course and pauci-immune necrotizing crescentic glomerulonephritis in their histology. Gregorini et al. reported that 12 of 37 (32%) male patients with RPGN had either silicosis or significant silica exposure, and 7 of 8 patients examined were ANCA-positive(6 of 7 were MPO-ANCA-positive). Therefore silica seems to cause glomerulonephritis by disrupting the immune response. Including this case mentioned above, we have experienced 10 cases of MPO-ANCA-associated glomerulonephritis, at least 3 cases out of which had suffered from silicosis in the past(30%). These results indicate that silicosis should be considered a relevant pathogen of MPO-ANCA-associated glomerulonephritis beyond the race.

Novel glomerular lipoprotein deposits associated with apolipoprotein E2 homozygosity

BACKGROUND

Hyperlipoproteinemia is occasionally associated with severe glomerular injury caused by abnormal accumulation of lipid in glomeruli, which occurs in conditions such as lipoprotein glomerulopathy (LPG). This study investigates the cases of two siblings with homozygous apolipoprotein (apo) E2 who show unique histologic features, massive proteinuria, and dysbetalipoproteinemia.

METHODS

Histologic studies were performed using renal biopsy specimens. Plasma lipoproteins were extensively characterized. The exons of the apo E genes were sequenced to avoid missing any mutations.

RESULTS

Histologically, the siblings' condition resembled LPG by light microscopy studies. Electron microscopy studies revealed large lipoid deposits in the paramesangium, subendothelium, and subepithelium of the glomeruli, which were different from LPG in terms of not forming the layered structure resembling a fingerprint even in large lipoprotein thrombi, and mesangial foam cells. Immunohistochemically, the lipoid deposits contained apo E and apo B. These patients did not have either diabetic nephropathy or other known forms of glomerulonephritis. The sequence of exons of the apo E genes revealed homozygosity for apo E2 in both cases.

CONCLUSION

The extensive lipoprotein deposition in glomeruli, which resembles LPG, can also occur in apo E2 homozygous individuals, but in a distinct fashion. Because the two cases were siblings, they may have other shared alleles, in addition to the apo E2 allele, that negatively affect processing of lipoproteins and lead to abnormal accumulation of lipoprotein deposits in glomeruli.

Expression of osteopontin in gentamicin-induced acute tubular necrosis and its recovery process

BACKGROUND

There is controversy regarding the exact localization and roles of osteopontin (OPN), a multipotential chemokine, in renal injury. There is little information on the expression and role of OPN in gentamicin-induced acute tubular necrosis (ATN) and its recovery process.

METHODS

A severe ATN model was made using male Wistar rats by injecting gentamicin (150 mg/kg/day) for five days and limiting the provision of water. The expression and localization of OPN mRNA and protein, ED1 as a macrophage marker, proliferating cellular nuclear antigen (PCNA), CD44 as an OPN receptor, megalin as a proximal tubule marker, and their relationships to each other were examined from the early tubular necrotic period to the late recovery period by Northern blotting, in situ hybridization, and double immunohistochemical staining.

RESULTS

In the gentamicin group, OPN mRNA and protein were expressed in only the PCNA-positive proliferating cortical distal tubules, not in the necrotic proximal tubules, until day 6 after the first administration, but were found markedly in PCNA-positive regenerative proximal and distal tubules on days 10, 15, and 30. The localization of PCNA-positive cells was almost always accompanied with the up-regulated expression of OPN using quantitative analysis (P < 0.01). CD44 expression was markedly up-regulated in the renal cortical tubular epithelium from days 6 to 30. In the control group, no expression of OPN and CD44 in the cortical area was found throughout the experimental period.

CONCLUSIONS

These results suggested that OPN is related to the proliferation and regeneration of tubular epithelial cells after tubular damage.

Determination of optimal blood pressure for patients with IgA nephropathy based on renal histology

To evaluate the optimal BP control for patients with IgA nephropathy (IgAN) based on the histologic severity of the nephropathy and the degree of renal dysfunction. We analyzed 332 consecutive renal biopsy specimens and clinical data from patients with IgAN. Patients were divided into three groups based on their BP at the time of biopsy: an optimal BP (SBP<120 mmHg and DBP<80 mmHg), a hypertensive BP (SBP > or = 140 mmHg and/or DBP > or = 90 mmHg), and an intermediate BP group. Each biopsy specimen was evaluated for mesangial proliferation, degree of sclerosis and/or hyalinosis of the arterioles and the interlobular artery using a semiquantitative method. Creatinine clearance and the percentage of sclerosed glomeruli were also determined. Both the degree of renal dysfunction and the histologic changes correlated significantly with BP, even in patients with a BP <140/90 mmHg. The patients with an optimal BP at the time of biopsy had significantly less histologic damage with respect to mesangial proliferation and vessel changes than those with an intermediate or hypertensive BP. In the patients with a hypertensive BP, the percentage of sclerotic glomeruli was significantly higher and the creatinine clearance was significantly lower. The optimal BP proposed by the WHO in 1999 prevents histologic evidence of renal damage for patients with IgAN.

Characterization, molecular cloning and expression of megakaryocyte potentiating factor

We examined whether the conditioned media of 64 kinds of cell lines, which have been maintained by a protein-free culture system, could produce megakaryocyte potentiating (Meg-POT) activity. In these cell lines, HPC-Y5, established from human pancreatic cancer, was shown to have the highest level of activity. The megakaryocyte potentiating factor (MPF) was purified from its conditioned medium by a combination of ion-exchange chromatography, gel filtration and reversed-phase HPLC. The purified MPF showed Meg-POT activity almost equal to human (Hu) interleukin 6 (IL-6) in the presence of murine IL-3 in a colony-forming assay with mouse bone marrow cells. The molecular weight of MPF was estimated to be 33 kDa by SDS-PAGE. Glycopeptidase F digestion and amino sugar analysis of the factor demonstrated that MPF is a glycoprotein carrying at least one N-linked sugar chain. The N-terminal amino acid sequence of MPF was determined to be Leu-Ala-Gly-Glu-Thr-Gly-Gln-Glu-Ala-Ala-Pro-Leu-Asp-Gly-Val-Leu-Ala-Asn. The same or homologous amino acid sequence has not been found in known proteins, demonstrating that MPF may be a novel cytokine which has Meg-POT activity. Then, we isolated HuMPF cDNA from an HPC-Y5 cDNA library using polymerase chain reaction and plaque hybridization methods. The HuMPF cDNA encodes a polypeptide consisting of 622 amino acids, including a signal peptide of 33 amino acids, and with a deduced molecular weight of 68 kDa, although HPC-Y5 cells secrete a 33 kDa form of HuMPF. HuMPF cDNA does not show any significant homology with other known sequences. The cDNA was expressed in COS-7 and Chinese hamster ovary (CHO) cells, and Meg-POT activity was detected in their culture supernatant. The COS-7 cells secreted only a 33 kDa recombinant (r)HuMPF, however, an additional 30 kDa form was detected in the culture medium of CHO cells. The 33 kDa rHuMPF from CHO cells showed Meg-POT activity, but not the purified 30 kDa rHuMPF. The difference in structure and activity between the 33 and 30 kDa forms of HuMPF was ascribed to the existence in the 33 kDa form of the C-terminal 25 amino acid residues. The expression of MPF mRNA was examined by Northern blot analysis using labeled MPF cDNA as a probe. MPF mRNA was detected in HPC-Y5 cells, with an approximate molecular size of 2.4 kb. We also examined the expression of the MPF gene in various human tissues, and the 2.4 kb band was detected only in lung. Then, the immunohistocytochemical analysis and in situ hybridization revealed that MPF-producing cells were identified as lung macrophages. MPF may exhibit other biological activities such as regeneration of the lung tissues.

Identification and characterization of three novel beta 1,3-N-acetylglucosaminyltransferases structurally related to the beta 1,3-galactosyltransferase family

We have isolated three types of cDNAs encoding novel beta1,3-N-acetylglucosaminyltransferases (designated beta3Gn-T2, -T3, and -T4) from human gastric mucosa and the neuroblastoma cell line SK-N-MC. These enzymes are predicted to be type 2 transmembrane proteins of 397, 372, and 378 amino acids, respectively. They share motifs conserved among members of the beta1,3-galactosyltransferase family and a beta1,3-N-acetylglucosaminyltransferase (designated beta3Gn-T1), but show no structural similarity to another type of beta1,3-N-acetylglucosaminyltransferase (iGnT). Each of the enzymes expressed by insect cells as a secreted protein fused to the FLAG peptide showed beta1,3-N-acetylglucosaminyltransferase activity for type 2 oligosaccharides but not beta1,3-galactosyltransferase activity. These enzymes exhibited different substrate specificity. Transfection of Namalwa KJM-1 cells with beta3Gn-T2, -T3, or -T4 cDNA led to an increase in poly-N-acetyllactosamines recognized by an anti-i-antigen antibody or specific lectins. The expression profiles of these beta3Gn-Ts were different among 35 human tissues. beta3Gn-T2 was ubiquitously expressed, whereas expression of beta3Gn-T3 and -T4 was relatively restricted. beta3Gn-T3 was expressed in colon, jejunum, stomach, esophagus, placenta, and trachea. beta3Gn-T4 was mainly expressed in brain. These results have revealed that several beta1,3-N-acetylglucosaminyltransferases form a family with structural similarity to the beta1,3-galactosyltransferase family. Considering the differences in substrate specificity and distribution, each beta1,3-N-acetylglucosaminyltransferase may play different roles.

Influence of intermittent ischemia on thioacetamide-induced rat liver cirrhosis

We studied the influence of intermittent ischemic injury on thioacetamide-induced liver cirrhosis in rats. Wistar rats were divided into group A, intermittent ischemic injury to liver cirrhosis, and group B, continuous ischemic injury to liver cirrhosis. Total ischemic time was 60 min in both groups. In group A, ischemic injury consisted of a repetition 4 times of 15 min ischemia and 5 min reperfusion. The ATP level of the liver was measured before ischemia, before reperfusion, and 60 min after reperfusion. Bile was collected to determine bile flow rate. The ATP level in the liver tissue 60 min after reperfusion was significantly (p < 0.05) higher in group A than in group B. The ATP level immediately before reperfusion was also significantly (p < 0.05) higher in group A than in group B. The survival rate 1 week after ischemic injury and bile flow rate 60 min after reperfusion were significantly (p < 0.01) higher in group A compared with those in group B. The energy level was much higher in intermittent ischemic injury than in continuous ischemic injury immediately before reperfusion and after reperfusion. Survival rate and bile flow rate were higher in intermittent ischemic injury than in continuous ischemic injury. Therefore it suggests that the viability of the liver was maintained better in intermittent ischemic injury than in continuous ischemic injury.

Treatment of membranoproliferative glomerulonephritis associated with hepatitis C virus infection. Niigata Research Group of Glomerulonephritis and Nephrotic Syndrome

OBJECTIVE

Interferon has been used as a new therapeutic agent for glomerulonephritis since a manifest relationship between membranoproliferative glomerulonephritis (MPGN) and hepatitis C virus (HCV) infection was documented. However, several side effects and rebound phenomenon have been significant problems. We retrospectively evaluated the therapeutic effect and safety of the standard treatment with steroids and/or immunosuppressive agents for MPGN patients with an HCV infection.

METHODS

Remission and renal survival rates as well as clinical and histological data were compared between MPGN groups with or without an HCV infection. In addition, the hepatic function was followed-up after the treatment.

PATIENTS

The subjects were 42 biopsy proven MPGN patients. Seven were positive for an HCV infection. Secondary causes of MPGN excluding an HCV infection were omitted. Most patients were treated with steroids and/or immunosuppressive agents.

RESULTS

The mean age of the MPGN patients with an HCV infection was significantly higher than that of those without an HCV infection. The renal function and the interstitial change of the former group were significantly worse than those of the latter. Nevertheless, remission and renal survival rates were not significantly different between the two groups. None in the HCV positive MPGN group showed an impairment of hepatic function during the clinical course. However, 2 subjects died from severe pneumonia during the treatment.

CONCLUSION

The standard treatment with steroids and/or immunosuppressive agents did not reveal a statistical difference in the therapeutic efficacy between MPGN patients with or without an HCV infection. However, some in the former group showed a poor prognosis.

N(G)-monomethyl-L-arginine inhibits erythropoietin gene expression by stimulating GATA-2

N(G)-monomethyl-L-arginine (L-NMMA) has been reported to be elevated in uremic patients. Based on the hypothesis that the pathogenesis of the anemia of renal disease might be due to the perturbation of transcription factors of the erythropoietin (Epo) gene by L-NMMA, the present study was designed to investigate the effect of L-NMMA on Epo gene expression through the GATA transcription factor. L-NMMA caused decreased levels of NO, cyclic guanosine monophosphate (cGMP), and Epo protein in Hep3B cells. L-NAME (analogue of L-NMMA) also inhibited Epo production in anemic mice. Transfection of the Epo promoter-luciferase gene into Hep3B cells revealed that L-NMMA inhibited the Epo promoter activity. However, L-NMMA did not inhibit the Epo promoter activity when mutated Epo promoter (GATA to TATA) was transfected, and L-NMMA did not affect the enhancer activity. Electrophoretic mobility shift assays demonstrated the stimulation of GATA binding activity by L-NMMA. However, L-NMMA had no effect on the binding activity of hepatic nuclear factor-4, COUP-TF1, hypoxia-inducing factor-1, or NF-kappaB. Furthermore, cGMP inhibited the L-NMMA-induced GATA binding activity. L-NMMA also increased GATA-2 messenger RNA expression. These results demonstrate that L-NMMA suppresses Epo gene expression by up-regulation of the GATA transcription factor and support the hypothesis that L-NMMA is one of the candidate substances that underlie the pathogenesis of renal anemia. (Blood. 2000;96:1716-1722)

Involvement of eosinophils in the early-phase allergic reaction in a guinea pig rhinitis model

BACKGROUND

Eosinophils are found in the nasal lavage fluid (NLF) and nasal biopsies of patients with allergic rhinitis after a nasal antigen challenge, and associated not only with a late-phase allergic reaction (LPR) but also an early phase allergic reaction (EPR). Numerous studies have been carried out to clarify the participation of eosinophils in LPR or airway hyperresponsiveness. However, there has been no published report describing in detail the role of eosinophils during EPR. To better understand the involvement of eosinophils in EPR, we studied the effects of repeated antigen challenges on nasal airway responsiveness and eosinophilic inflammation in EPR using a guinea pig rhinitis model.

METHODS

Nasal airway responsiveness was measured as the nasal airway resistance (NAR) after nasal antigen provocation. Eosinophilic inflammation during EPR was assessed by nasal lavage and histopathological examination using two groups of animals: those in group 1 were subjected to a sensitization pretreatment only, and those in group 2 were subjected to a pretreatment of sensitization followed by repeated nasal challenges.

RESULTS

Repeated antigen challenges induced nasal hyperresponsiveness as indicated by a decrease in the antigen provocation dose and a significant increase in NAR. Furthermore, significant increases in eosinophil counts, eosinophil peroxidase (EPO) activity and protein content in NLF during EPR were observed following antigen provocation in group 2. There were significant correlations between the levels of these parameters, and albumin was the most prevalent of the proteins in NLF. Histopathological examination showed that the degree of eosinophil infiltration into the lamina propria of the nasal mucosa of the animals in group 2 was significantly and apparently higher than in group 1. Particularly, epithelial disruption and mucosal edema were significantly elevated after antigen provocation in group 2.

CONCLUSIONS

These results suggest that chronic eosinophil accumulation is induced by repeated antigen challenges in the nasal tissue, and that once antigen provocation occurs, eosinophils in the tissue are activated and responsible for the amplification of EPR such as vascular permeability and mucosal edema.

Analysis of interaction between molecules of Bombyx mori nucleopolyhedrovirus IE-2 using a yeast two-hybrid system

Baculovirus IE-2 protein is one of well-known transactivators. In this report, we demonstrate that Bombyx mori nucleopolyhedrovirus (BmNPV) IE-2 interacts with itself. Several clones were obtained from a yeast two-hybrid screening system using IE-2 as bait and were found to encode IE-2 protein. Nucleotide sequencing of these clones showed that they contained C-terminal regions in common. Further analyses suggest that BmNPV IE-2 protein interacts with itself through 80 amino acid residues of coiled-coil domain in C-terminus.

Effects of portal-systemic shunt following 90% partial hepatectomy in rats

We studied the effects of portal-systemic shunt after massive hepatectomy. Male Wistar rats were divided into two groups: one group underwent laparotomy alone (C group) and in the other group a portal-systemic shunt was placed through laparotomy (S group). After 90% hepatectomy was performed, 3-day and 1-week survival rates and histopathology were examined, and hepatic hemodynamics during the early stage after hepatectomy were measured using dye-containing microspheres. The 3-day survival rate in the S group was significantly higher, and the 1-week survival rate was slightly higher, than those in C group. Sinusoidal dilation 7 days after hepatectomy in the S group was significantly milder than that in the C group. Fatty degeneration of hepatocytes in the S group was significantly milder than that in the C group. With respect to hepatic hemodynamics during the early stage after hepatectomy, the rate of shunt (26.3%) in the S group was significantly higher than that (9.5%) in the C group. Portal pressure, total hepatic blood flow, and total hepatic blood flow per gram of liver in the S group were significantly lower than those in the C group. These results suggest that approximately 26% shunt after 90% hepatectomy in rats increases the early survival rate and improves histological changes in surviving rats 7 days after resection.

[Short interval change of 99mTc-ethyl cysteinate dimer single photon emission computed tomography in Wilson's disease]

We studied short interval change of cranial computed tomography (CT), magnetic resonance imaging (MRI) and 99mTc-ethyl cysteinate dimer single photon emission computed tomography (99mTc-ECD SPECT) in a case of Wilson's disease. Before treatment, CT scan showed low density changes in the bilateral thalamus and basal ganglia, and MRI demonstrated high intensity in same lesions. 99mTc-ECD SPECT study revealed a hypoperfusion in bilateral thalamus. After 2 months under D-penicillamine therapy, neurological findings had improvement. Hypoperfusion in the thalamus with 99mTc-ECD SPECT significantly improved, whereas abnormal findings of CT scan and MRI persisted. 99mTc-ECD SPECT study may be useful for the planning of the treatment of Wilson's disease.

Chamber-specific regulation of heme oxygenase-1 (heat shock protein 32) in right-sided congestive heart failure

Heme oxygenase (HO)-1 is a stress protein (HSP 32) and, together with HO-2, catalyses oxidation of the heme molecule to generate carbon monoxide, a gas with vasodilatory properties, and bilirubin, an antioxidant. Right-sided heart failure (RHF) resulted in a two-fold increase in the HO-1 transcript (;1.8 kb) in the right ventricle (RV) of RHF dogs compared to that of controls. In contrast, the left ventricle showed no increase in HO-1 mRNA in RHF. The change in HO was unique to HO-1, because neither the HO-2 transcripts (;1.3 and 1.9 kb) nor the HSP 70 mRNA was altered in either ventricle. This increase in HO-1 mRNA in RV was accompanied by a two-fold increase in immunoreactive HO-1 protein, as judged by Western blot analysis, as well as by a significant increase in cGMP levels. There was, however, no significant increase in RV total nitric oxide synthase activity in RHF. Furthermore, since norepinephrine infusion also increased HO-1 transcript and protein levels, the HO-1 system probably was induced in RHF by the increased interstitial norepinephrine levels known to occur in failing myocardium. This differential regulation and induction of HO-1 gene in the failing ventricle might be one of the defense mechanisms by which the heart attempts to protect from stress caused by congestive heart failure.

Molecular cloning of mouse p47, a second group mammalian RuvB DNA helicase-like protein: homology with those from human and Saccharomyces cerevisiae

A 47k protein (p47) in a high-salt buffer extract of a rat liver nuclear matrix fraction was purified by means of a wheat germ agglutinin affinity column, reversed phase HPLC, and SDS-PAGE, and partial amino acid sequences were analyzed. Based on these sequences, the mouse cDNA of the protein was cloned and sequenced, and its amino acid sequence was deduced. Mouse p47 consists of 463 amino acid residues with a molecular weight of 51,112. The amino acid sequences of human and Saccharomyces cerevisiae p47s were also deduced from the nucleotide sequences of "expressed sequence tag" fragments and genomic DNA, respectively. These sequences contain helicase motifs and show homology to bacterial RuvB DNA helicases acting in homologous recombination. They also show homology with the putative mammalian helicases p50/TIP49 and RUVBL1. Comparison of the amino acid sequences of p47 group proteins and those of p50/TIP49 group proteins revealed the p47 group proteins to comprise a group distinct from the p50/TIP49 proteins. Ultracentrifugation and gel filtration analyses showed that p47 in the rat liver cytosol fraction exists as large complexes of 697k.

[Effect on gene expression of the expanded CTG repeat on 3'-untranslated region of myotonic dystrophy (DM) protein kinase]

Myotonic dystrophy is an autosomal dominant heritable disease associated with an expansion of CTG trinucleotide repeat within 3' untranslated region of the DMPK gene. The key question is how the mutation in the 3' untranslated region of the DMPK gene exerts an dominant effect at the cellular level, despite the fact that it does not alter the protein coding region of the gene. Although the mechanism of myotonic dystrophy remains controversial, some evidence suggests that CUG repeats in the DMPK mRNA may have pathological effects. A hypothesis on molecular mechanism of DM pathogenesis, in terms of RNA-protein interactions and regulation of gene expression through the 3' untranslated region of mRNAs, was discussed.

The leukotriene B4 receptor antagonist ONO-4057 inhibits nephrotoxic serum nephritis in WKY rats

To evaluate the role of leukotriene B4 (LTB4) in glomerulonephritis, this study was conducted to examine whether ONO-4057, an LTB4 receptor antagonist, moderated nephritis caused by the injection of nephrotoxic serum (NTS) into Wistar-Kyoto rats. Rats were given intraperitoneal injections of ONO-4057 or phosphate-buffered saline 24 h before the injection of NTS. These rats subsequently received equal doses of ONO-4057 or phosphate-buffered saline 3 h and 1, 2, 3, 4, 5, and 6 d later. Compared with the control groups, ONO-4057 treatment significantly reduced proteinuria and hematuria, suppressed the glomerular accumulation of monocytes/macrophages, and reduced the formation of crescentic glomeruli in a dose-dependent manner. These results suggest that LTB4 is responsible for the crescentic formations and renal dysfunction associated with NTS nephritis. The LTB4 receptor antagonist ONO-4057 may thus be beneficial in the treatment of crescentic glomerulonephritis.

Comparison of complications of vaginal hysterectomy in patients with leiomyomas and in patients with adenomyosis

We reviewed 1246 vaginal hysterectomies performed at Handa City Hospital between January 1984 and December 1996. We divided the patients into 2 groups: those with leiomyomas (n = 893) and those with adenomyosis (n = 353). There was no difference in operative time and estimated blood loss between the 2 groups when analyzed by uterine weight. However, adenomyosis was associated with an increased risk of bladder injury.

Gonadotropin-releasing hormone-induced elevation of serum hCG in choriocarcinoma: a case report

We evaluated the effect of GnRH on the serum hCG level in gestational trophoblastic disease (GTD). Five patients with GTD were studied. Three patients had hydatidiform mole (two complete and one partial mole) and two had choriocarcinoma. Blood samples were collected immediately before and 30, 60 min after the 100 microg GnRH iv injection, followed by hCG assay. Only one case of choriocarcinoma demonstrated an hCG increase after intravenous administration of GnRH (positive GnRH test). In that case, the hCG level dropped to the normal range after eight cycles of chemotherapy but the GnRH test was still positive, suggesting the existence of viable cancer cells. Since the GnRH test became negative, no increase in hCG has been observed, indicating that the patient achieved complete remission. Although a positive GnRH test is not common in GTD, GnRH test before treatment might be useful to find a positive case where the test can be repeated to determine complete remission and the time when the chemotherapy may be discontinued.