DnaK heat shock protein of Escherichia coli maintains the negative supercoiling of DNA against thermal stress

Plasmid DNA in exponentially growing Escherichia coli immediately relaxes after heat shock, and the relaxed state of DNA rapidly reverts to the original state with exposure to conditions of heat shock. We have now obtained genetic and biochemical evidence indicating that DnaK heat shock protein of E. coli, a prokaryotic homologue of hsp70, is involved in this re-supercoiling of DNA. As re-supercoiling of DNA did not occur in an rpoH amber mutant, it seems likely that heat shock proteins are required for this reaction. Plasmid DNA in a dnaK deletion mutant relaxed excessively after temperature shift-up, and the re-supercoiling of DNA was not observed. DNAs incubated with a crude cell extract prepared from the dnaK mutant were more relaxed than seen with the extract from its isogenic wild-type strain, and the addition of purified DnaK protein to the mutant extract led to an increase in the negative supercoiling of DNA. Moreover, reaction products of purified DNA gyrase more negatively supercoiled in the presence of DnaK protein. Based on these results, we propose that DnaK protein plays a role in maintaining the negative supercoiling of DNA against thermal stress.

[Analysis of contributing factors with high renal uptake of 99mTc-MDP after anti-cancer chemotherapy including cisplatin]

We studied the effect of anti-cancer chemotherapy including cis-platin (CDDP) on renal high uptake of 99mTc-MDP using renal accumulation index (RAI) which was defined as a ratio of the densities between kidneys and lumbar bodies. We analyzed 21 cases who received bone scintigraphy within 30 days after chemotherapy. High RAIs were observed in 15 cases (71.4%). We compared the relationship between the RAI and time interval of CDDP administration and bone scintigraphy, total dose of CDDP, BUN and age. High RAIs were inversely related to the time interval and no patient showed high RAI when bone scintigraphy were studied later than 17 days after chemotherapy. BUN level were related to RAI. But, dose of CDDP and ages were unlikely responsible for the RAI values in this study. We summarized that high renal uptake of 99mTc-MDP was likely to be due to short time interval after chemotherapy.

Histamine H1 receptor-induced Ca2+ mobilization and prostaglandin E2 release in human gingival fibroblasts. Possible role of receptor-operated Ca2+ influx

Stimulation of human gingival fibroblasts with histamine elicited an increase in the intracellular concentration of free calcium ([Ca2+]i) and the formation of inositol 1,4,5-trisphosphate (InsP3) in a concentration- and time-dependent manner. The histamine-induced increase in [Ca2+]i was attenuated completely by chlorpheniramine, an H1 antagonist, but not by cimetidine, an H2 antagonist. The histamine-induced Ca2+ response consisted of an initial transient peak response and a subsequent sustained increase. The transient phase can be largely attributed to Ca2+ release from intracellular InsP3-sensitive stores since the increased [Ca2+]i effect of histamine completely disappeared after depletion of intracellular Ca2+ stores with thapsigargin in the absence of extracellular Ca2+. The sustained phase was due to Ca2+ influx which was attenuated in the absence of extracellular Ca2+. The Ca2+ influx required the continuous binding of histamine to the receptor, since chlorpheniramine attenuated the increase in [Ca2+]i observed when extracellular Ca2+ was re-applied to the cells after stimulation with histamine in the absence of extracellular Ca2+. Pretreatment with the Ca2+ channel blocker SK&F96365 inhibited the Ca2+ influx component, suggesting that histamine stimulates Ca2+ influx through an H1 receptor-operated Ca2+ channel. Histamine also evoked a concentration- and time-dependent release of prostaglandin E2 (PGE2). The histamine-evoked PGE2 release was reduced markedly by exclusion of extracellular Ca2+ or pretreatment with SK&F96365 or an H1 antagonist. These results indicate that histamine stimulates both the intracellular Ca2+ release from InsP3-sensitive stores and the H1 receptor-operated Ca2+ influx from extracellular sites. The increased [Ca2+]i due to the Ca2+ influx causes PGE2 release in human gingival fibroblasts.

Heat shock-induced DNA relaxation in vitro by DNA gyrase of Escherichia coli in the presence of ATP

Genetic studies revealed that DNA gyrase seems to catalyze immediate and transient DNA relaxation after Escherichia coli cells are exposed to heat shock (Ogata, Y., Mizushima, T., Kataoka, K., Miki, T., and Sekimizu, K. (1994) Mol. Gen. Genet. 244, 451-455). We have now obtained biochemical evidence to support this hypothesis. DNA gyrase catalyzed an increase in the linking number of DNA and relaxation of negatively supercoiled DNA, under physiological concentrations of ATP. Analyses by gel filtration chromatography of each subunit revealed that DNA relaxation activity co-migrated with each subunit. The linking number of DNA increased as the temperature increased. Further, the reaction was inhibited by nalidixic acid or by oxolinic acid. Based on these results, we propose that DNA gyrase participates in a concerted reaction with DNA topoisomerases in the immediate relaxation of DNA in cells exposed to heat shock.

Tumor necrosis factor alpha (TNFalpha) induces pro-matrix metalloproteinase 9 production in human uterine cervical fibroblasts but interleukin 1alpha antagonizes the inductive effect of TNFalpha

We have examined the regulation of precursor of matrix metalloproteinase 9 (proMMP-9)/progelatinase B production by tumor necrosis factor alpha (TNFalpha) and interleukin 1alpha (IL-1alpha) using human uterine cervical fibroblasts. TNFalpha, but not IL-1alpha, induces the production of proMMP-9 in the cervical cells. IL-alpha, however, suppresses the TNFalpha-induced proMMP-9 production. 12-0-tetradecanoylphorbol 13-acetate (TPA) also stimulates the cervical cells to produce proMMP-9, and IL-1alpha synergistically enhances its production. TNFalpha-induced proMMP-9 production is not mediated by protein kinase C (PKC), whereas the effect of IL-1alpha is through PKC. By contrast, proMMP-3/prostromelysin 1 is up-regulated by TNFalpha or TPA in the presence of IL-1alpha, whose modulation is PKC-dependent. The suppressive effect of IL-1alpha on the TNFalpha-induced proMMP-9 production is a new biological effect of IL-1 on MMP production.

Identification of a vitamin D3-response element that overlaps a unique inverted TATA box in the rat bone sialoprotein gene

Bone sialoprotein (BSP), an early marker of osteoblast differentiation, has been implicated in the nucleation of hydroxyapatite during bone formation de novo. Our studies, using the osteoblastic cell line ROS 17/2.8, have revealed that rat BSP gene expression is suppressed by 1,25-dihydroxyvitamin D3[1,25(OH)2D3], which is a powerful regulator of bone formation and resorption. To determine the molecular basis of the transcriptional suppression of BSP gene transcription by 1,25(OH)2D3, we have conducted transient transfection analyses with chimaeric constructs of the rat BSP gene promoter linked to a luciferase reporter gene. 1,25(OH)2D3 suppressed expression in all constructs, including a short construct (pLUC 3; nt -116 to +60) that contained a putative vitamin D3-response element (VDRE; AGGGTTTATAGGTCA; nt -28 to -14) that overlaps a unique inverted TATA (TTTATA) box. Mobility shift assays demonstrated strong binding of recombinant human vitamin D3 receptor protein (hVDR) to the VDRE. Point mutations introduced into each half-site and analysed for 1,25(OH)2D3-mediated suppression of transcription and for hVDR binding either decreased or increased both transcriptional suppression and binding. In comparison with activating VDREs, the rat BSP VDRE bound VDR-VDR homodimers more avidly than VDR-RXR alpha heterodimers (where RXR is retinoid X receptor). These studies have therefore identified a novel 1,25(OH)2D3 suppressor element that overlaps the inverted TATA box in the rat BSP gene and indicate that transcriptional suppression of the rat BSP gene by 1,25(OH)2D3 might involve competition between the VDR and the TATA binding protein (TBP).

The fractional inhibitory concentration index of antimicrobial agents for bacteria and Mycoplasma isolated from the nasal swabs of cattle with respiratory diseases

We investigated the effect of thiamphenicol plus lincomycin (TP + LCM) and thiamphenicol plus tylosin (TP + TS) combinations using checker board method on the growth of Pasteurella (P.) multocida, P. haemolytica and Mycoplasma (M.) bovis by calculating the fractional inhibitory concentration index (FIC index). The results showed that the FIC indexes of the TP + LCM combination for P. multocida, P. haemolytica and M. bovis were 0.36 +/- 0.10, 0.72 +/- 0.09 and 0.81 +/- 0.18, respectively. The FIC indexes of the TP + TS combination for P. multocida, P. haemolytica, and M. bovis were 0.79 +/- 0.20, 0.66 +/- 0.11 and 0.32 +/- 0.14, respectively. Thus, these combinations are assumed to have a more synergistic or additive effect on bacteria growth than a single antimicrobial agent.

Effect of a combination of antimicrobial agents for the treatment of respiratory disease in cattle

Clinical effect of the administration of thiamphenicol (TP) and tylosin (TS) on bovine respiratory disease was investigated. Group I (n = 64) were administered TP (10 mg/kg) and TS (4 mg/kg), group II (n = 26) were given TP (5 mg/kg) and TS (2 mg/kg). For the control, TP group (n = 25) were given 20 mg/kg of TP and ampicillin group (n = 23) were given 10 mg/kg of ampicillin. As a result, improvement of clinical findings was more rapid and the cure rate was significantly higher in group I compared to those in the other 3 groups. These results showed that a combination therapy with minimal basic doses of TP and TS is very effective for some respiratory diseases in cattle.

AP-1 regulation of the rat bone sialoprotein gene transcription is mediated through a TPA response element within a glucocorticoid response unit in the gene promoter

Bone sialoprotein (BSP), a protein which has been implicated in the initial mineralization of newly-formed bone, provides an early phenotypic marker for differentiated osteoblasts. BSP expression is induced by glucocorticoids in association with osteoblast differentiation, and a glucocorticoid response element (GRE) overlapping a putative TRE (TPA, 12-O-tetradecanoyl-phorbol 13-acetate, response element) site has been identified in the rat BSP promoter (Ogata et al., 1995). Since AP-1 and the glucocorticoid receptor have a central role in regulating cell proliferation and differentiation, we have studied AP-1 activity, stimulated by 100 ng/ml TPA in normal fetal rat calvarial cells and in transformed rat osteosarcoma cells (ROS 17/2.8). A transient induction of both c-fos and c-jun mRNAs by TPA was observed in both cell populations, together with an associated suppression of BSP mRNA in the fetal rat calvarial cells. Rat BSP promoter constructs, transiently transfected into ROS 17/2.8 cells, were used to show that TPA suppressed transcription of a luciferase construct (-938/+60; pLUC6) that included the GRE/TRE, but not transcription of shorter contructs lacking this element. Notably, suppression of pLUC6 transcription by TPA was abrogated in the presence of the synthetic glucocorticoid, dexamethasone. Gel mobility shift analyses were performed using two double-stranded synthetic oligonucleotides. These encompassed the TRE and either the distal pair of GRE half-sites (-936/ -910; GRE3) or the proximal pair of GRE half-sites (-925/-899; GRE 4) that comprise the GRE/AP-1 element. The assay showed binding of both AP-1 complexes and recombinant c-Jun homodimers. Additionally, either the c-Jun or glucocorticoid receptor could displace its counterpart from the GRE/TRE but not from consensus GRE and TRE oligonucleotides, indicating that the abrogation of AP-1-mediated gene suppression by glucocorticoids could involve competitive binding. These studies, therefore, have identified a glucocorticoid response unit through which c-Fos and c-Jun can suppress the expression of BSP in proliferating pre-osteoblastic cells and through which glucocorticoids can ameliorate the effects of AP-1 and promote osteoblast differentiation and the associated expression of BSP.

Morgagni hernia diagnosed by MRI

We herein present a patient with Morgagni hernia which was diagnosed by magnetic resonance imaging (MRI). The patient had a progressively enlarging mass in the right cardiophrenic angle on chest roentgenogram. On computed tomography (CT) scans, the mass was revealed to have fat density and therefore was suspected to be either a lipoma or liposarcoma. MRI clearly demonstrated that the mass shadow was composed of omental fat herniating into the right thorax through the diaphragmatic hiatus. MRI is thus considered to be a useful noninvasive modality for the evaluation of lower anterior mediastinal masses demonstrating fat density on CT.

[Prospective randomized trial comparing 1/2 FAM (5-fluorouracil (5-FU) + adriamycin + mitomycin C) versus palliative therapy for the treatment of unresectable pancreatic and biliary tract carcinomas (the 2nd trial in non-resectable patients). Japanese Study Group of Surgical Adjuvant Therapy for Carcinomas of the Pancreas and Biliary Tract]

The efficacy of 1/2 FAM, which consists of 5-fluorouracil (5-FU), adriamycin (ADM) and mitomycin C (MMC), was compared with that of palliative treatment in patients with unresectable pancreatic and biliary tract carcinomas in a multicenter randomized trial. The patients assigned to 1/2 FAM group were treated with 5-FU 200 mg/m2/day IV, ADM 15 mg/m2/day IV and MMC 5 mg/m2/day IV. These 3 drugs were given concurrently as the initial dose within a week after palliative operation, and this regimen was repeated for at least 2 whole courses, at 4-week intervals before the next course of therapy. Those randomized to the control group were subjected to palliative treatment alone. Completely eligible for analysis were 42 cases of the 1/2 FAM group and 41 of the control group. There was no significant difference between the groups with respect to the overall and differentiated survival times according to the tumor sites and the clinical efficacy. As for the duration of 50% inhibition of tumor progression, a significantly better outcome was obtained in 1/2 FAM group. Tumor progression was most significantly inhibited in patients with gallbladder carcinoma. In 1/2 FAM group, tumor reduction was achieved in 1 CR and 2 PR patients. The most frequent adverse reaction was gastrointestinal manifestations, along with diarrhea and alopecia. 1/2 FAM did not contribute to the life prolongation, but inhibited the tumor progression for a significantly longer duration and, to a lesser extent, reduced the tumor size in unresectable pancreatic and biliary tract carcinomas. This regimen is suggested to be useful particularly in the treatment of the latter carcinoma.

[Immunohistochemical labeling of inner ear tissues embedded in polyethylene glycol 4000--comparative study with araldite and unicryl embedded sections]

An improved method for embedding specimens in polyethylene glycol (PEG) 4000, a water soluble polymer, was used to prepare the vestibular end-organs of the inner ear. Staining of the tissue sections of PEG embedded specimens with antibodies to alpha-tubulin and to calmodulin was compared with staining of tissue sections of Araldite and Unicryl embedded specimens. PEG embedded sections revealed sensitive immunocytochemical labeling with excellent morphological resolution. The problems of embedding and orienting small specimens of the inner ear in PEG are described and the methods used to solve them are described.

Histamine H1 receptor-stimulated Ca2+ signaling pathway in human periodontal ligament cells

We studied histamine-induced Ca2+ mobilization in human periodontal ligament (HPDL) cells. Histamine induced a transient rise in intracellular Ca2+ ([Ca2+]i) and maintained a sustained phase in the presence of extracellular Ca2+. In the absence of extracellular Ca2+, the transient peak was slightly reduced and the sustained phase was decreased to the basal level. The initial rise in [Ca2+]i was attributed to two components: intracellular Ca2+ release and Ca2+ influx, whereas the sustained phase was due to Ca2+ influx. After depletion of intracellular Ca2+ stores with thapsigargin, a known Ca(2+)-ATPase inhibitor, histamine-induced increase in [Ca2+]i was significantly reduced, suggesting histamine induces Ca2+ release from inositol 1,4,5-trisphosphate [Ins(1,4,5)P3]- and thapsigargin-sensitive Ca2+ stores. Histamine-induced peak in [Ca2+]i was increased dose-dependently in the presence and absence of extracellular Ca2+. The histamine-mediated response in [Ca2+]i was specifically attenuated by chlorpheniramine (H1 antagonist) but not by cimetidine (H2 antagonist), clearly indicating that activation of H1 receptor mediates histamine-induced Ca2+ mobilization. We next examined the effect of histamine on inositol phosphates formation. Histamine stimulated the formation of inositol phosphates which changed time-dependently. In particular, the formation of Ins(1,4,5)P3 was increased significantly for 10 s. The histamine-induced Ca2+ mobilization caused an increase of prostaglandin E2 (PGE2) release which was reduced in excluding extracellular Ca2+. These results indicate that activation of histamine H1 receptor induces the accumulation of Ins(1,4,5)P3 and the following transient increase in [Ca2+]i, and elicits the release of PGE2 which may be coupled with Ca2+ influx.

Effects of traditional herbal medicine on gastric mucin against ethanol-induced gastric injury in rats

The effect of the traditional herbal medicine, Rikkunshi-to and its component crude drugs, Zingiberis Rhizoma and Glycyrrhizae Radix, on the gastric mucin was studied using a method developed to separate and quantify the mucin localized in the different layers of rat gastric mucosa. The oral administration of spray-dried extract to Rikkunshi-to (1000 mg/kg), Zingiberis Rhizoma (500 mg/kg) and Glycyrrhizae Radix (500 mg/kg) significantly prevented gastric mucosal damage induced by 70% ethanol in rats. In ethanol-treated rats the mucin content of the deep mucosa was reduced, and the reduction of the deep corpus mucin content was significantly inhibited by pretreatment of Rikkunshi-to and Zingiberis Rhizoma. Rikkunshi-to and Glycyrrhizae Radix pretreatment increased the surface mucin content by 140 and 146%, respectively. The effect on the gastric mucin by each drug differed in the different layers of the gastric mucosa.

Characterization of the bone sialoprotein (BSP) gene promoter

Bone sialoprotein is a 34 kDa phosphorylated and sulphated glycoprotein that is essentially unique to mineralizing connective tissues. Recent studies on the developmental expression of BSP mRNA and the temporo-spatial appearance of the protein during bone formation in vivo and in vitro have demonstrated that BSP is expressed by differentiated osteoblasts and that it may function in the initial nucleation of hydroxyapatite crystals in de novo bone formation. To study the cell-specific regulation of BSP we have isolated genomic clones that encompass the BSP promoter regions of both the human and rat genes. These promoters are characterized by a highly conserved region (BSP Box) that extends upstream from the transcription start site to nt -370. Within this region the immediate promoter is further characterized by a unique inverted TATA box and an inverted CCAAT box, both of which are required for basal transcriptional activity. The TATA box is overlapped by a vitamin D3 response element (VDRE) which appears to mediate vitamin D suppression of BSP gene transcription by competing with the TATA-binding protein (TBP) for occupancy of the site of the pre-initiation complex formation. Mutation of the inverted TATA box into a normal TATA sequence increases transcription slightly but does not affect the functionality of the VDRE indicating that the orientation of the TATA box is not critical for these functions. Further upstream an AP-1 site, overlapped by a steroid hormone response-like sequence, mediates down-regulation of BSP transcription induced by TPA that is abrogated by a complex interaction between Jun and the glucocorticoid receptor protein induced by dexamethasone. Thus, the characterization of approximately 3 kb of the BSP promoter and approximately 2 kb of the first intron has revealed several sites of transcriptional regulation that are important in regulating BSP expression and, consequently, bone formation.

[Infective endocarditis associated with vertebral osteomyelitis: report of two cases]

A 42-year-old man and a 65-year-old woman with infective endocarditis suffered onset of severe back pain. Magnetic resonance imaging and technetium-99 m bone scanning demonstrated osteomyelitis in the lumbar spine which is an unusual complication of infective endocarditis. The man was treated by antibiotics and finally aortic valve replacement and laminectomy with bone grafting. The woman had small patent ductus arteriosus and developed aortic regurgitation, but was treated by antibiotics and corset application with good result. The possibility of osteomyelitis in the lumbar spine should be considered in a patient with endocarditis complaining of severe back pain. The appropriate antibiotic therapy over a prolonged period is recommended.

Immunohistochemical localization of vascular endothelial growth factor in esophageal cancer

We have studied the expression of vascular endothelial growth factor (VEGF) in esophageal cancer using immunohistochemistry. A total of 101 specimens of esophageal cancer tissue were fixed by formalin, embeded in paraffin wax, and examined in 3 microns sections by avidin-biotin peroxidase complex method. VEGF was noted in the cytoplasm of normal esophageal glandular cells, monocyte-macrophages, squamous carcinoma cells and of the vascular endothelial cells themselves. VEGF expression by monocyte-macrophages was observed in all cases, in contrast the incidence of VEGF expression in the tumor cells was relatively low at 26.7% of all specimens. However, in the cases where the tumor cells were positive for VEGF, it was discovered that the main source of the VEGF production was the tumor cells themselves. In the cases with proper mucosal invasion the incidence of VEGF expression by the tumor cells was quite low at 7.6%. However, when the tumor invaded the submucosal layer the expression increased to 33.3%. There was also a significant correlation in those with the submucosal invasion between the expression of VEGF in the tumor cells and that VEGF may play an important role in tumor progression and in the angiogenesis via auto-crine and para-crine mechanisms in esophageal cancer.

Hepatic arterial chemotherapy for liver metastases from colorectal cancer

We have investigated the complications, toxicities, tumor response and survival rate with hepatic arterial (HA) chemotherapy for liver metastases from colorectal cancer. Forty-three patients with measurable liver metastases and 10 patients after the resection of liver metastases were treated with HA bolus mitomycin C (MMC) or continuous fluorouracil (5-FU) infusion between 1986 and 1994. The catheter- or reservoir-related complications such as catheter induced infection, subcutaneous reservoir pocket infection, or catheter or hepatic artery occlusion occurred in 14 patients (26%) mainly in our early cases. Severe gastritis or a gastroduodenal ulcer developed in 12 patients (23%), in particular after treatment with continuous infusion of 5-FU and when the catheter was placed into the gastroduodenal artery during laparotomy. An ulcer often caused a serious complication such as a duodeno-biliary fistula, penetration into the hepatic artery or duodenal perforation. Also noted were upper gastrointestinal symptoms in 26 patients, hepatic toxicities in 3 patients, and bone marrow depression in 4 patients. Because of these complications and toxicities, HA therapy was discontinued in more than 60% of the cases. The overall tumor response rate was 17%. However, in the cases which were treated by 5-FU continuous infusion for longer than 3 months, the response rate was higher than 60%. There was no significant difference in survival rate between HA therapy and systemic palliative chemotherapy. These results suggest that it is important to prevent gastrointestinal toxicities in order to allow continuation of HA continuous 5-FU infusion therapy which could provide a higher response rate and a better survival for colorectal cancer patients with liver metastases.

Angiotensin converting enzyme as a genetic risk factor for coronary artery spasm. Implication in the pathogenesis of myocardial infarction

It has been reported that individuals with the D allele of an insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene are at greater risk for myocardial infarction (MI), especially among subjects normally considered to be at low risk. However, little is known about the mechanism by which the ACE polymorphism affects the risk of MI. Coronary artery spasm (CAS) is considered to be one possible mechanism for developing MI. We therefore examined the ACE polymorphism relation to CAS to determine if this was the mechanism by which the DD genotype influences MI. We studied 150 angiographically assessed Japanese males, all more than 60 yr old. CASs were detected using intracoronary injection of ergonovine maleate. Subjects were divided into three groups: those with CAS (group 1), those without CAS, but with fixed organic stenosis (group 2); and those without CAS and no organic stenosis (group 3). DD subjects were significantly represented in group 1 when compared with groups 2 (P = 0.002) and 3 (P = 0.026). These results suggest that the DD genotype relates to the greater risk for MI in the patients with CAS.

Comparison of the characteristics of human gingival fibroblasts and periodontal ligament cells

To elucidate the characteristics of human periodontal ligament cells, we compared these cells with gingival fibroblasts isolated from the periodontal tissues of female human subjects. Human periodontal ligament (HPDL) cells had a sharper spindle shape and exhibited a higher growth rate than human gingival fibroblasts (HGF). HPDL cells had a high level of alkaline phosphatase (ALPase) activity, whereas HGF had a low level of such activity. Northern blot analysis demonstrated that HPDL cells produced ALPase mRNA. Decorin and biglycan mRNA were detected in both HPDL cells and HGF, whereas osteocalcin and bone sialoprotein mRNA was not detected in either cells. Both HPDL cells and HGF responded to prostaglandin E2 (PGE2) and isoproterenol, and produced cyclic AMP (cAMP), but did not respond to human 1-34 parathyroid hormone (PTH). Intracellular Ca2+ ([Ca2+]i) was measured in HPDL cells and HGF, using Fura 2-AM. Bradykinin (BK) and histamine (HIS), which are major chemical mediators, caused a transient rise of [Ca2+]i in the presence of extracellular Ca2+. In HGF, but not HPDL cells, HIS induced a biphasic transient peak in [Ca2+]i. BK and HIS increased PGE2 release in both HPDL cells and HGF. However, HGF released a larger amount of PGE2 than HPDL cells. These results demonstrate that HPDL cells have quite different characteristics from HGF. HPDL cells proliferate at a higher rate than HGF, show higher levels of cAMP production and greater ALPase activity, and respond in a different fashion to chemical mediators (BK and HIS) compared with HGF.

Importance of matrix metalloproteinases in human trophoblast invasion

Human cytotrophoblast cells are invasive by virtue of their ability to secrete metalloproteinases (MMP) capable of digesting the extracellular matrix of the endometrium. It is the aim of the present study to determine which of the known MMP is responsible for this invasive behavior and to see to what extent endometrial secretions can modulate this enzymatic activity. Under our experimental conditions, first-trimester cytotrophoblast cells invade matrigel; this invasive behavior is inhibited by phenanthroline (an inhibitor of MMP) and by a polyclonal antibody to the 92-kDa gelatinase but not to other MMP. Since cytotrophoblast cells cultured in vitro secrete the 92-kDa gelatinase, and since adhesion to a substrate increases their gelatinolytic activity, it is believed that cytotrophoblast cells invade their surrounding matrix by binding to it and by increasing their secretion of 92-kDa gelatinase which then digests the collagen type IV of their micro-environment. This process of invasion is controlled by secretions from decidual cells (but not from non-decidualized stromal cells) since conditioned medium from decidual cells inhibits the activity of the 92-kDa gelatinase released from cytotrophoblast cells.

Effect of the initial bolus volume of recombinant tissue-type plasminogen activator on coronary recanalization and infarct size in Japanese acute myocardial infarction patients. Kumamoto University Myocardial Infarction Study (KUMIS) Group

Coronary recanalization rate and infarct size were compared between 2 different methods of intravenously administering recombinant tissue-type plasminogen activator (rt-PA) 41.4 mg; 1) an initial bolus dose of 30% followed by infusion of the remainder over 60 min (30% group), and an initial bolus dose of 10% followed by infusion of the remainder over 60 min (10% group). Thirty min after beginning rt-PA infusion, the coronary recanalization rate was higher in the 30% group than in the 10% group (82.9% (34/41) vs 53.7% (22/41), p < 0.01). The peak creatine kinase and peak creatine kinase-MB levels were lower in the 30% group than in the 10% group. We conclude that a higher initial bolus dose of rt-PA gives a higher rate of recanalization of the infarct-related artery at the very early phase, and probably leads to a smaller infarct size.

Automated smear counting and data processing using a notebook computer in a biomedical research facility

An automated smear counting and data processing system for a life science laboratory was developed to facilitate routine surveys and eliminate human errors by using a notebook computer. This system was composed of a personal computer, a liquid scintillation counter and a well-type NaI(Tl) scintillation counter. The radioactivity of smear samples was automatically measured by these counters. The personal computer received raw signals from the counters through an interface of RS-232C. The software for the computer evaluated the surface density of each radioisotope and printed out that value along with other items as a report. The software was programmed in Pascal language. This system was successfully applied to routine surveys for contamination in our facility.

[The relationship between the improvement of cardiac function and the myocardial uptake of I-123 metaiodobenzylguanidine in patients with dilated cardiomyopathy treated by beta-blocker]

Chronic beta-blocker therapy improves hemodynamics and cardiac function in patients with idiopathic dilated cardiomyopathy. However, the change in myocardial uptake of I-123 metaiodobenzylguanidine (123I-MIBG) before and after treatment has not been determined. Myocardial imaging with 123I-MIBG was performed before and 2 or 3 months after beta-blocker (bisoprolol) therapy in 11 patients with dilated cardiomyopathy. The following parameters were compared before and after the treatment: 1) New York Heart Association functional class, 2) X-ray cardiothoracic ratio, 3) heart rate and blood pressure, 4) echocardiographic data (left ventricular end-diastolic and end-systolic diameters, and left ventricular ejection fraction), 5) plasma concentrations of epinephrine, norepinephrine and human atrial natriuretic peptide (HANP), and 6) exercise tolerance time by treadmill. The heart-to-mediastinum ratio of 123I-MIBG activities obtained 3 hours after intravenous injection (late H/M) and washout rate improved significantly after beta-blocker therapy. Cardiothoracic ratio, heart rate, echocardiographic parameters, HANP and exercise tolerance also improved significantly. Late H/M had no significant relationship with any of the clinical parameters, but washout rate was significantly related to left ventricular ejection fraction. These findings suggest that washout rate may be useful to assess the effect of short-term beta-blocker therapy in dilated cardiomyopathy patients.

Steps involved in activation of the pro-matrix metalloproteinase 9 (progelatinase B)-tissue inhibitor of metalloproteinases-1 complex by 4-aminophenylmercuric acetate and proteinases

The precursor of matrix metalloproteinase 9 (pro-MMP-9, progelatinase B) noncovalently binds to tissue inhibitor of metalloproteinases (TIMP)-1 through the C-terminal domain of each molecule. We have isolated the proMMP-9.TIMP-1 complex from the medium of human fibrosarcoma HT-1080 cells and investigated the activation processes of the complex by 4-aminophenylmercuric acetate, trypsin, and matrix metalloproteinase 3 (MMP-3, stromelysin 1). The treatment of the proMMP-9.TIMP-1 complex with 4-aminophenylmercuric acetate or trypsin converts proMMP-9 to lower molecular weight species corresponding to active forms, but no gelatinolytic activity is detected. The lack of enzymic activity results from binding of TIMP-1 to the activated MMP-9. The treatment of the proMMP-9.TIMP-1 complex with a possible physiological proMMP-9 activator, MMP-3, does not reveal any gelatinolytic activity unless the molar ratio of MMP-3 to the complex exceeds 1. This is due to the inhibition of MMP-3 by TIMP-1 forming a ternary proMMP-9.TIMP-1.MMP-3 complex. The formation of the ternary complex weakens the interaction between proMMP-9 and TIMP-1, resulting in partial dissociation of the complex into proMMP-9 and the TIMP-1.MMP-3 complex. When MMP-3 is in excess, the propeptide is completely processed, and the full activity of MMP-9 is detected. Similarly, the proMMP-9.TIMP-1 complex inhibits MMP-1 (interstitial collagenase) and in turn renders the proMMP-9 activable by a catalytic amount of MMP-3. These results suggest that formation of the proMMP-9.TIMP-1 complex regulates extracellular matrix breakdown in tissue by switching the predominant MMP activity from one type to another.