Interleukin-2-dependent but not independent T-cell lines infected with human T-cell leukemia virus type 1 selectively express CD45RO, a marker for persistent infection in vivo

Human T-cell leukemia virus type 1 (HTLV-1) is an etiologic agent of adult T-cell leukemia. HTLV-1 is exclusively detected in CD45RO+ T-cells in infected individuals, but CD45RO is weakly expressed in HTLV-1-transformed T-cell lines in vitro. The aim of this study was to investigate the role of CD45RO in the persistent HTLV-1 infection in vivo. Flow cytometry showed that only two out of eight interleukin(IL)-2-independent HTLV-1-transformed T-cell lines expressed CD45RO, whereas all five IL-2-dependent ones expressed CD45RO, and the level of expression was higher in IL-2-dependent than in IL-2-independent cells. The high CD45RO expression in IL-2-dependent cell lines was not due to IL-2, since IL-2 had little effect on the expression of CD45RO in T-cell lines. Using western blotting, we showed that IL-2-dependent HTLV-1-transformed T-cell lines expressed a lower level of expression of the viral transcriptional regulatory protein Tax than IL-2-independent ones, and that the level of expression correlated inversely with that of CD45RO. However, the expression of Tax in one HTLV-1-negative T-cell line little affected the expression of CD45RO, suggesting that Tax at least alone does not suppress the expression of CD45RO in HTLV-1-infected T-cell lines, and that other viral or cellular factor(s) are probably involved in such suppression. Our results suggest that CD45RO+ Tax-low IL-2-dependent T-cell lines in vitro correspond to the persistent HTLV-1-infected cells in vivo, and HTLV-1-infected cells in vivo are immortalized in IL-2-dependent manner.

Revisiting [3 + 3] route to 1,3-cyclohexanedione frameworks: hidden aspect of thermodynamically controlled enolates

We have revisited the traditional consecutive Michael-Claisen [3 + 3] process (MC-[3 + 3]) promising the synthesis of a cyclohexane-1,3-dione derivatives from nonactivated simple ketones and enoates and evaluated its potential in modern organic synthesis. Twenty to thirty examples were demonstrated to be effective. The reactions exhibited remarkable regioselectivity with the Michael addition proceeding through nucleophilic attack by the more hindered site of the ketones without exception. The subsequent Claisen condensation resulted in the formation of carbon-carbon bonds between less hindered site of the ketones and acyl carbon of the enoates. The MC-[3 + 3] process described is useful for the synthesis of Taxol A-ring synthons in multigram quantities and for the synthesis of other six-membered carbocyclic compounds. A number of control experiments have been conducted to provide strong support for the mechanism of this MC-[3 + 3].

Refolding of beta-lactoglobulin studied by stopped-flow circular dichroism at subzero temperatures

Refolding of bovine beta-lactoglobulin was studied by stopped-flow circular dichroism at subzero temperatures. In ethylene glycol 45%-buffer 55% at -15 degrees C, the isomerization rate from the kinetic intermediate rich in alpha-helix to the native state is approximately 300-fold slower than that at 4 degrees C in the absence of ethylene glycol, whereas the initial folding is completed within the dead time of the stopped-flow apparatus (10 ms). At -28 degrees C, we observed at least three phases; the fastest process, accompanied by an increase of alpha-helix content, is completed within the dead time of the stopped-flow apparatus (10 ms), the second phase, accompanied by an increase of alpha-helix content with the rate of 2 s(-1), and the third phase, accompanied by a decrease of alpha-helix content. This last phase, corresponding to the isomerization process at -15 degrees C described above, was so slow that we could not monitor any changes within 4 h. Based on the findings above, we propose that rapid alpha-helix formation and their concurrent collapse are common even in proteins rich in beta-structure in their native forms.

Chlorogentisylquinone, a new neutral sphingomyelinase inhibitor, produced by a marine fungus

Chlorogentisylquinone, a new inhibitor of neutral sphingomyelinase activity, was purified from the culture broth of a fungal strain FOM-8108 isolated from a marine environment by solvent extraction, silica gel chromatography and Sephadex LH-20 chromatography. Its chemical structure was elucidated by spectroscopic studies including 1H, 13C, DEPT, HMQC and HMBC NMR experiments. Chlorogentisylquinone inhibited neutral sphingomyelinase activity of rat brain membranes with an IC50 value of 1.2 microM.

Maturation of mass-screened localized adrenal neuroblastoma

BACKGROUND/PURPOSE

In infants, neuroblastoma has been known to spontaneously differentiate into a benign ganglioneuroma. Although several investigators have compared mass-screened with unscreened, disseminated with localized, and adrenal with retroperitoneal neuroblastoma, there are very few cross-comparisons of the above parameters. Herein, the authors report the maturation of mass-screened, localized adrenal neuroblastoma.

METHODS

Fifty-one mass-screened adrenal neuroblastomas were divided into 2 groups. In infants less than 1 year of age (Group A), 45 neuroblastomas were resected, whereas 6 neuroblastomas were resected after observation in 1- to 4-year-old children (group B). Histopathology of the tumors in the 2 groups was compared. Data were analyzed by X(2) test, and P <.05 was considered significant.

RESULTS

According to the International Neuroblastoma Pathological Classification, 41 of 45 tumors of group A were "differentiating neuroblastoma" and 4 of 6 tumors of group B were "maturing ganglioneuroma." Maturation toward ganglioneuroblastoma was observed in 16 neuroblastomas of group A (36%) and 6 neuroblastomas of group B (100%). In group A, 58% had low mitosis karyorrhexis index (MKI); all patients in group B had low MKI.

CONCLUSIONS

If left untreated, maturation of mass-screened, localized adrenal neuroblastomas is a common phenomenon. These children do not need to undergo early operation.

Penile agenesis complicated by Potter sequence

We present a case of penile agenesis complicated by multicystic dysplastic kidneys and urethral agenesis, which resulted in oligohydramnios, pulmonary hypoplasia and neonatal death. In this case, no external urethral opening was found, and the gastrointestinal tract showed no anomaly. Cases of penile agenesis complicated by Potter sequence with urethral agenesis should be differentiated from those with ectopic urethral openning.

Adenocarcinoma of the nonpigmented ciliary epithelium: report of two cases with immunohistochemical findings

BACKGROUND

Acquired neoplasms arising from the nonpigmented ciliary epithelium (NPCE) are much less common than uveal melanocytic proliferations. We report two cases of acquired neoplasms arising from the NPCE with immunohistochemical findings.

METHODS

Case reports.

RESULTS AND CONCLUSIONS

Patient 1 was a 39-year-old man who presented with a pigmented mass behind the iris and secondary exudative retinal detachment. The eye also developed neovascular glaucoma. Patient 2 was a 44-year-old woman with a ciliary body mass but without symptoms. Both of these tumors were classified histologically as low-grade adenocarcinomas of the NPCE from specimens successfully removed by iridocyclectomy. Immunohistochemical findings confirmed the origin of the tumor cells; however, some changes in the immunoreactivity to cytokeratin AE1 and epithelial membrane antigen were found.

[A case of spontaneous intracranial hypotension with simultaneous CSF leaks at the upper and lower thoracic levels]

We presented a patient of spontaneous intracranial hypotension (SIH), in which radionuclide cisternography demonstrated multiple CSF leaks. A 51-year-old previously healthy woman awoke with a severe headache and nausea that were almost completely relieved by lying flat (day 1). The headache was not relieved by analgesics. On day 10, she visited our clinic. Neurological examination showed no abnormalities. A lumbar puncture revealed an opening pressure of 50 mmH2O, protein level of 64 mg/dl, 21 erythrocytes 21/microliter, and 4 lymphocytes/microliter. Cranial MRI on day 11 with gadolinium infusion demonstrated diffuse thickening and enhancement of the meninges. No signs of venous sinus thrombosis were identified. There was no downward displacement of the cerebellar tonsils. Indium-111 radionuclide cisternography demonstrated early accumulation of the tracer in the urinary bladder and CSF leakage at the upper thoracic level on the left side, at the lower thoracic level on both sides, and at the lumbar level. It is noteworthy that the scintigram taken 4 hours after tracer injection demonstrated CSF leakage at the injection site but not in the upper thoracic area. The patient kept sitting for about 20 minutes just before the images were obtained. Spinal MRI did not show meningeal diverticulum and epidural fluid collection. Ten days of bed-rest and transfusion failed to relieve the headache. Epidural patching with 7 ml of autologous blood performed at the Th2/3 interspace partially relieved the headache. Five days later, a second epidural patching was performed at Th11/12, which was slightly effective. A third epidural patching at L3/4 was ineffective. On day 32, a fourth epidural patching was performed at Th1/2 while the patient was lying down on her left side. The postural headache disappeared. Repeated cranial MRI with gadolinium infusion performed on day 47 showed resolution of the abnormal findings. To our knowledge, this is the second case report of SIH with double CSF leaks. To localize multiple leaks, radionuclide cisternography should be performed with a patient in various positions just before images are obtained.

[Immune coagulation disorders (excluding antiphospholipid syndrome]

During the course of replacement therapy, 22-30% of patients with severe hemophilia A develop alloantibody to factor VIII. Autoantibodies to coagulation factors rarely occur in elder individuals with previously normal hemostatic mechanisms or in patients with various underlying disorders. Although the great majority of the acquired inhibitors are directed to factor VIII, the antibodies may arise to every coagulation factor. The inhibitor antibodies directly inactivate specific clotting factor, or occasionally, they bind to a nonfunctional site, resulting in increased plasma clearance. In the last decade, we experienced 12 hemophilia A and 3 hemophilia B patients who developed factor VIII and factor VIII and factor IX inhibitor, respectively, 9 patients with autoantibody to factor VIII (acquired hemophilia), and 4 patients with acquired von Willebrand syndrome. Among 12 factor VIII inhibitors, 4 patients were identified to have inversion in the factor VIII gene, 1 with 4 bases deletion, and 1 with missense mutation resulting in G479R. Four of 9 patients with acquired hemophilia had underlying disorders of autoimmune hemolytic anemia, macroglobulinemia, urticaria, and pharyngeal cancer at the development of factor VIII inhibitor. Antibody to von willebrand factor was detected in 3 of 4 patients with acquired von Willebrand syndrome.

Dynamic change of cells expressing MMP-2 mRNA and MT1-MMP mRNA in the recovery from liver fibrosis in the rat

BACKGROUND/AIMS

The aim of this study was to investigate whether both matrix metalloproteinase-2 (MMP-2) and membrane type 1 MMP (MT1-MMP) participate in the spontaneous resolution of liver fibrosis.

METHODS

Transcription of both genes was examined by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization (ISH). Gelatinase activity was investigated by zymography.

RESULTS

Gene expression by RT-PCR showed that both genes increased in the process of liver fibrosis, then decreased gradually in the recovery phase. ISH revealed that distribution of positive cells changed quickly in the recovery phase. Positive cells were widely seen in the liver, mainly around fibrous septa, in the aggressive phase, but were exclusively observed at the interface between the resolving fibrous band and the parenchyma, then were diffusely located in the lobules in the recovery phase. Main cells expressing both mRNAs seemed to be stellate cells for their morphology, though they did not express characteristic cell markers. Some hepatocytes and Kupffer cells expressed both mRNAs in the recovery phase. Gelatinase activity of MMP-2 increased in the recovery phase of 8-week-treated rat liver by gelatin zymography.

CONCLUSIONS

The results of present study suggest that both enzymes participate in the destruction of extracellular matrix in coordination with MMP-13.

Stress thallium-201 myocardial scintigraphy in patients with complete occlusion of the left main coronary artery

Complete occlusion (CO) of the left main coronary artery (LMCA) is a rare but often fatal condition. The diagnosis is frequently missed because the signs and symptoms are often obscure and diverse. We describe three patients with CO-LMCA who showed unusual myocardial scintigraphic findings. The patients had extensive right-to-left collateral channels and decreased uptake and washout rates at the basal anterior and anterolateral portions of the heart wall during stress thallium-201 scintigraphy. The basal anterior to anterolateral portion of the heart wall is the most distant from the collateral artery and should be the most ischemic area shown during exercise, resulting in this scintigraphic pattern. This scintigraphic finding may be useful for the noninvasive diagnosis of CO-LMCA.

Caspase-dependent and serine protease-dependent DNA fragmentation of myocytes in the ischemia-reperfused rabbit heart: these inhibitors do not reduce infarct size

Some infarcted myocytes undergo caspase-dependent DNA fragmentation, but serine protease-dependent DNA fragmentation may also be involved. There is controversy regarding whether caspase inhibitors can reduce infarct size, so the present study investigated whether serine protease inhibitor can reduce the DNA fragmentation of infarcted myocytes and whether serine protease or caspase inhibitors attenuates myocardial infarct size in Japanese white rabbits without collateral circulation. Rabbits were subjected to 30-min coronary occlusion followed by 48-h reperfusion. A vehicle (dimethylsulfoxide, control group, n=8) or Z-Val-Ala-Asp(Ome)-CH2F (ZVAD-fmk, a caspase inhibitor, ZVAD group, 0.8 mg/kg iv at 20 min before coronary occlusion and 0.8 mg/kg at 90 min after reperfusion, n=8) or 3,4-dichloroisocoumarin (DCI, a serine protease inhibitor, 2 mg/kg iv at 20 min before coronary occlusion, DCI group, n=8) was administered. Animals were killed at 48h after reperfusion for the detection of myocardial infarct size and at 4h after reperfusion for the detection of dUTP nick end-labeling (TUNEL)-positive myocytes, the electrophoretic pattern of DNA fragmentation and ultrastructural analysis. The left ventricle (LV) was excised and sliced. The myocardial infarct size as a percentage of the area at risk was assessed by triphenyltetrazolium chloride staining. DNA fragmentation was assessed by in situ TUNEL at the light microscopic level. ZVAD and DCI significantly reduced the mean blood pressure during reperfusion without affecting heart rate. There was no significant difference in the % area at risk (AAR) of LV among the 3 groups (control: 26.3+/-3.0%; ZVAD: 25.6+/-2.6%; DCI: 25.6+/-2.0%). The % infarct size as a percentage of the AAR in the ZVAD group (41.3+/-4.5%) and the DCI group (50.4+/-3.8%) was not significantly different from the control group (43.5+/-4.5%). However, the percent DNA fragmentation in the infarcted area in the ZVAD (3.5+/-0.8%) and DCI groups (4.2+/-0.9%) was significantly reduced compared with the control group (10.7+/-1.9%). The DNA ladder pattern observed in the control group was attenuated in both the ZVAD and DCI groups. There was no difference in electron microscopic changes among the 3 groups. Serine protease-dependent DNA fragmentation is present in infarcted myocytes, in addition to caspase-dependent DNA fragmentation, but an infarct-size reducing effect was not observed with either of these inhibitors.

Electroretinogram contact lens electrode with tri-color light-emitting diode

PURPOSE

This study was performed to evaluate a new electroretinogram (ERG) contact lens electrode containing four light-emitting diodes (LEDs) that are used for both stimulus and background light.

METHODS

The luminance of each LED could be changed independently and used as stimulus light. Red, blue, bright white, and flickering ERGs were recorded in 12 normal subjects and two patients with progressive cone dystrophy. The long-duration light stimuli separated the on- and off-responses of the ERG. This equipment is not according to the ISCEV standard.

RESULTS

The tri-color LED electrode contact lens can efficiently produce and record ERG responses. Off-responses were recordable separately from on-responses by lengthening the stimulus duration.

CONCLUSION

This combined stimulus-electrode system is compact and portable. Combined with the portable amplifier and the recorder, the ERGs can be recorded easily in an operating room, at patients' bedside, and in remote locations away from clinics and hospitals.

Effects of the use of cross-education to the affected side through various resistive exercises of the sound side and settings of the length of the affected muscles

The purpose of this study was to determine what kind of resistive exercise of the sound limb causes the most effective cross-education, which is defined as the muscle activity of the unexercised limb during contralateral exercise, by analyzing the force and electrical activity of the affected muscle. Six orthopedic patients with unilateral lower extremity impairment that resulted in unexercised quadriceps muscles through treatment by immobilization were the subjects of this investigation. The effect of cross-education was determined by observing the maximal torque of the unexercised quadriceps (MT) and the integrated electromyograms of the unexercised rectus femoris at the time of the maximal response of the torque (IE). A double-blind experiment was conducted with eighteen randomly applied combinations, consisting of six different exercises and three different knee angles. The various resistive exercises on the sound side consisted of proprioceptive neuromuscular facilitation (PNF) movements, PNF positions, straight movements and straight positions in the sagittal plane. Both the mean percentage of the IE and MT were above 23% in the PNF movement, while a mean above 13% was not found in any of the other exercises. PNF movement combined with hip internal rotation was found to be significantly effective for inducing cross-education.

Recurrent pyogenic vertebral osteomyelitis associated with type 2 diabetes mellitus

We report a case of recurrent pyogenic vertebral osteomyelitis associated with type 2 diabetes mellitus. A 51-year-old male was admitted to our hospital because of lumbago and general fatigue, with multiple ulcers on the soles of his feet. Staphylococcus aureus was isolated from peripheral blood and the foot ulcers, and 67Gallium scintigram showed abnormal isotope uptake, accumulated at the lower thoracic spine. Antibiotics were administered and the patient underwent intensive insulin therapy. Magnetic resonance imaging (MRI), performed after the levels of C-reactive protein decreased to 0.0 mg/dl, indicated old inflammatory changes at the Th8-Th9 spine and antibiotics were stopped. Unexpectedly, 8 days later the patient complained of lumbago with fever again, and MRI showed acute inflammatory changes at the same lesion site. This case report suggests that it is important for complementary antibiotic therapy to continue after signs of inflammation have disappeared in cases of pyogenic vertebral osteomyelitis.

Noninvasive quantitative tissue characterization and two-dimensional color-coded map of human atherosclerotic lesions using ultrasound integrated backscatter: comparison between histology and integrated backscatter images

OBJECTIVES

The purpose of the present study was to define clinicopathologically whether integrated backscatter (IB) combined with conventional two-dimensional echo (2DE) can differentiate the tissue characteristics of calcification (CL), fibrosis (FI), lipid pool (LP) with fibrous cap, intimal hyperplasia (IH) and thrombus (TH) and can construct two-dimensional tissue plaque structure in vivo.

BACKGROUND

It is difficult to characterize the components of plaque using conventional 2DE techniques.

METHODS

Integrated backscatter values of plaques were measured in the right common carotid and femoral arteries (total 24 segments) both during life and after autopsy in 12 patients (age 68 to 84 years, 10 men and two women). Integrated backscatter values were determined using a 5-12 MHz multifrequency transducer, setting the region of interests (ROIs) (11 x 11 pixels) on the echo tomography of the entire arterial wall (55 +/- 10 ROI/segment) and comparing it with histologic features in the autopsied arterial specimens.

RESULTS

Corrected IB values obtained before death and at autopsy were significantly correlated (r = 0.93, p < 0.01). Corresponding to the histologic features, corrected IB values on the rectangle ROIs obtained during life were divided into five categories: category 1 (TH) 4 < IB < or = 6; category 2 (media and IH or LP in the intima) 7 < IB < or = 13; category 3 (FI) 13 < IB < or = 18, category 4 (mixed lesion) 18 < IB < or = 27 and category 5 (CL) 28 < IB < or = 33. In category 2, media and intima were differentiated using conventional 2DE. Under the above procedures, color-coded maps constructed with IB-2DE obtained during life precisely reflected the histologic features of media and intima.

CONCLUSIONS

Integrated backscatter with 2DE represents a useful noninvasive tool for evaluating the tissue structure of human plaque.

Both mosquito-derived xanthurenic acid and a host blood-derived factor regulate gametogenesis of Plasmodium in the midgut of the mosquito

Gametogenesis of Plasmodium in vitro can be induced by the combined stimulus of a 5 degrees C fall in temperature and the presence of xanthurenic acid (XA). In-vitro experiments showed that P. gallinaceum (EC(50)=80 nM) is much more sensitive to XA than P. berghei (9 microM), P. yoelii (8 microM), and P. falciparum (2 microM). However, in the mosquito vector, we do not know whether the temperature shift and XA are the only gametocyte-activating factors (GAF), nor do we know with certainty the true source(s) of XA in the mosquito blood meal. Previous studies indicate that XA is the only source of GAF in the mosquito. By defining, and then contrasting, the ability of an XA-deficient mutant of Aedes aegypti, with the wild-type mosquito to support exflagellation and ookinete formation in vivo, we determined the roles of parasite-, mosquito- and host blood-derived GAF in the regulation of gametogenesis of P. gallinaceum. Removal of both host and vector sources of GAF totally inhibited both exflagellation and ookinete production, whilst the lack of either single source resulted in only a partial reduction of exflagellation and ookinete formation in the mosquito gut. Both sources can be effectively replaced/substituted by synthetic XA. This suggests (1) both mosquito- and vertebrate-derived factors act as GAF in the mosquito gut in vivo; (2) the parasite itself is unable to produce any significant GAF activity. Studies are underway to determine whether vertebrate-derived GAF is XA. These data may form the basis of further studies of the development of new methods of interrupting malarial transmission.

Genetic and epigenetic events in human hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is the most frequently occurring liver carcinoma world-wide. Clinical and molecular medical analyses have produced a considerable amount of information about liver carcinogenesis. Loss of heterozygosity (LOH) analyses have revealed several chromosomal loci harboring potential tumor suppressors. These data support the idea that deletion or inactivation of tumor suppressors including RB, p53, BRCA2, E-cadherin and other candidate genes seem to be common events in HCC development. Factors associated with cell cycle regulation via the Wnt- and MAPK/ERK signaling pathways are frequently deregulated in hepatocarcinogenesis. Aberrant activation of telomerase also occurs in precancerous as well as cancerous lesions in HCC patients. To characterize the wide variety of genetic events that occur in HCC, mRNA expression has been compared in HCC and non-cancerous liver tissues, and several differentially expressed genes have been identified. Hepatitis B and C viruses are the main risk factors for HCC, and indeed some accessory functions of viral products seem to contribute to tumor development; however, whether they have a direct carcinogenic effect has not yet been established.

Dual-subtype FIV vaccine protects cats against in vivo swarms of both homologous and heterologous subtype FIV isolates

OBJECTIVE

To evaluate the immunogenicity and efficacy of an inactivated dual-subtype feline immunodeficiency virus (FIV) vaccine.

DESIGN

Specific-pathogen-free cats were immunized with dual-subtype (subtype A FIV(Pet) and subtype D FIV(Shi)) vaccine and challenged with either in vivo- or in vitro-derived FIV inocula.

METHODS

Dual-subtype vaccinated, single-subtype vaccinated, and placebo-immunized cats were challenged within vivo-derived heterologous subtype B FIV(Bang) [10--100 50% cat infectious doses (CID(50))], in vivo-derived homologous FIV(Shi)(50 CID(50)), and in vitro- and in vivo-derived homologous FIV(Pet)(20--50 CID(50)). Dual-subtype vaccine immunogenicity and efficacy were evaluated and compared to single-subtype strain vaccines. FIV infection was determined using virus isolation and proviral PCR of peripheral blood mononuclear cells and lymphoid tissues.

RESULTS

Four out of five dual-subtype vaccinated cats were protected against low-dose FIV(Bang) (10 CID(50)) and subsequently against in vivo-derived FIV(Pet) (50 CID(50)) challenge, whereas all placebo-immunized cats became infected. Furthermore, dual-subtype vaccine protected two out of five cats against high-dose FIV(Bang) challenge (100 CID(50)) which infected seven out of eight single-subtype vaccinated cats. All dual-subtype vaccinated cats were protected against in vivo-derived FIV(Pet), but only one out of five single-subtype vaccinated cats were protected against in vivo-derived FIV(Pet). Dual-subtype vaccination induced broad-spectrum virus-neutralizing antibodies and FIV-specific interferon-gamma responses along with elevated FIV-specific perforin mRNA levels, suggesting an increase in cytotoxic cell activities.

CONCLUSION

Dual-subtype vaccinated cats developed broad-spectrum humoral and cellular immunity which protected cats against in vivo-derived inocula of homologous and heterologous FIV subtypes. Thus, multi-subtype antigen vaccines may be an effective strategy against AIDS viruses.

Deacetylravidomycin M, a new inhibitor of IL-4 signal transduction, produced by Streptomyces sp. WK-6326. I. Taxonomy, fermentation, isolation and biological activities

Streptomyces sp. WK-6326, a soil isolate, was found to produce an inhibitor of interleukin (IL)-4 signal transduction. Two structurally related compounds, a novel one designated deacetylravidomycin M and the known deacetylravidomycin, were isolated from the culture broth by solvent extraction, silica gel column chromatography and HPLC. Deacetylravidomycin M inhibited IL-4-induced CD23 expression in U937 cells without any cytotoxic effect, whereas deacetylravidomycin showed no inhibitory activity.

Serum acid phosphatase as a tumour marker in giant cell tumour of bone

The serum acid phosphatase value was examined in nine patients with giant cell tumour of bone. Five showed a high level of acid phosphatase, which fell to within normal limits after surgery. Although the remaining four patients showed a normal acid phosphatase level before surgery, the postoperative acid phosphatase level was lower than the preoperative level in each case. Therefore, it is strongly suggested that serum acid phosphatase is a useful tumour marker in diagnosing giant cell tumour of bone as well as in evaluating the efficacy of treatment.

Analysis of photochemical pollution in summer and winter using a photochemical box model in the center of Tokyo, Japan

In order to give an effective and rapid analysis of the photochemical pollution and information for emission control strategies, a photochemical box model (PBM) was applied to one moderate summer episode, 11 July 1996, and one typical winter episode, 3 December 1996, in the center of Tokyo, Japan. The box model gave a good prediction of the photochemical pollution with minimal investment. As expected, the peak ozone in summer is higher than in winter. The NOx concentrations in winter are higher than those in summer. In summer, NO and NO2 have one peak in the morning. In winter, NO and NO2 show two peaks during the day. Three model runs including no reactions, a zero ozone boundary condition and dark reactions were conducted to understand the photochemical processes. The effects of emission reduction on the formation of the photochemical pollution in the center of Tokyo have been studied. The results show that the reduction of NMHC emission can decrease the ozone, however, the reduction of NOx emission can increase the ozone. It can be concluded that if the NOx emission are reduced, the reduction of NMHC should be more emphasized in order to decrease the ozone concentration in the center of Tokyo, Japan, especially the reduction of the NMHC from stationary source emission.

Combination of N-methyl-1-deoxynojirimycin and ischemic preconditioning markedly reduces the size of myocardial infarcts in rabbits

N-methyl-1-deoxynojirimycin (NMDN), an a-glucosidase inhibitor, reduces myocardial infarct size by reducing the glycogenolytic rate through inhibition of the alpha-1,6-glucosidase of glycogen-debranching enzyme in the heart, in addition to possessing an antihyperglycemic action by blocking alpha-1,4-glucosidase in the intestine. Ischemic preconditioning (PC), which markedly reduces the size of the myocardial infarct, is known to reduce the activity of phosphorylase and reduce the glycogenolytic rate. Therefore, it was hypothesized that a combination of pharmacological inhibition of glycogenolysis by an alpha-1,6-glucosidase inhibitor, NMDN, and PC could markedly reduce myocardial infarct size more than NMDN or PC alone. Japanese white rabbits without collateral circulation were subjected to a 30-min coronary occlusion followed by 48-h reperfusion. The infarct sizes as a percentage of area at risk were significantly reduced by pre-ischemic treatment with either 100mg/kg of NMDN or PC of 5 min ischemia and 5 min reperfusion alone (15.9+/-2.0%, n=8, and 10.3+/-1.2%, n=8, respectively) as compared with the control (43.9+/-2.2%, n=8). However, the combination of 100mg/kg of NMDN and PC significantly reduced the infarct size (4.9+/-1.2, n=8) compared with NMDN or PC alone. Another 40 rabbits, also given 100mg of NMDN, PC, NMDN+PC or saline before ischemia (n=10 in each group), were killed for biochemical analysis after 30 min of ischemia. NMDN and PC preserved the glycogen content and attenuated the lactate accumulation, respectively, as compared with the control. However, the combination of NMDN and PC preserved significantly more glycogen and significantly reduced lactate accumulation than either NMDN or PC alone. The combination of NMDN and PC markedly reduced the myocardial infarct size more than either process alone. The marked preservation of glycogen and marked attenuation of lactate accumulation by the combination of NMDN and PC suggest that the mechanism for this effect of NMDN+PC is related to the inhibition of glycogenolysis.

Surgical treatment for abdominal neuroblastoma in the laparoscopic era

BACKGROUND

The role of laparoscopy in children with cancer has not been fully defined. The aims of this study were to develop an optimal surgical procedure for the treatment of abdominal neuroblastoma in the laparoscopic era and to evaluate the advantages and disadvantages of laparoscopy in the pediatric population.

METHODS

Since July 1997, 37 children were diagnosed with abdominal neuroblastoma at our center, and 44 surgical procedures were performed on them. Patients with advanced neuroblastoma underwent laparoscopic biopsy, open biopsy, and delayed primary or second-look excision, whereas early neuroblastoma cases had either laparoscopic or open excision. We compared the length of the operation, intraoperative blood loss, length of hospital stay, complications, and time to start postoperative feeding and chemotherapy for the laparoscopic and open surgery groups.

RESULTS

Length of stay and time to postoperative feeding and chemotherapy were significantly lower in the laparoscopic group than the open surgery group. However, there were no significant differences between the two groups in length of operation and intraoperative blood loss.

CONCLUSION

Laparoscopic biopsy and excision of abdominal neuroblastoma are effective and efficient surgical procedures in children.

Combined effect of retinoic acid and basic FGF on PAI-1 gene expression in vascular smooth muscle cells

OBJECTIVE

Aberrant regulation of the synthesis and degradation of the extracellular matrix (ECM) is associated with the pathophysiology of vascular disease. Plasminogen activator inhibitor-1 (PAI-1) plays a crucial role in regulating the quantity and composition of ECM. However, regulatory mechanisms underlying the expression of the PAI-1 gene remain unclear. We examined the effects of all-trans-retinoic acid (atRA), either alone or in combination with mitogenic growth factor, basic fibroblast growth factor (bFGF), on the PAI-1 expression in cultured vascular smooth muscle cells (SMCs).

METHODS

Cultures of the rabbit vascular smooth muscle cell line C2/2 were used to study the effects of atRA and bFGF separately or together.

RESULTS

Treatment of vascular SMCs with atRA in combination with bFGF resulted in an additional increase in PAI-1 expression both at the mRNA and protein levels. In contrast, tissue-type plasminogen activator, urokinase-type plasminogen activator and tissue factor mRNA levels were only minimally affected. The all-trans-RA- and bFGF-mediated increases in PAI-1 mRNA levels were markedly attenuated by the tyrosine kinase inhibitor genistein, but not by MEK1 or p38MAP kinase inhibitors. The rate of decrease in PAI-1 mRNA levels after actinomycin D treatment was not affected by atRA and bFGF. Transient transfection of the PAI-1 promoter-luciferase reporter gene, which contains 967 bp of the 5'-flanking region of the human PAI-1 gene, revealed that atRA and bFGF additionally increased transcription from this promoter. Progressive 5'-deletion revealed that the promoter region required for such an effect lies between -967 and -260, which contains no canonical sequence for the RA-response element. In agreement with the role of PAI-1 in the inhibition of fibrinolytic activity which stimulates ECM degradation, cell migration was inhibited by treatment with atRA and bFGF.

CONCLUSIONS

These results indicate that atRA and bFGF can function in a combined fashion and induce PAI-1 synthesis in vascular SMCs, and suggest a role for these two compounds in regulating SMC migration.

Deacetylravidomycin M, a new inhibitor of IL-4 signal transduction, produced by Streptomyces sp. WK-6326. II. Structure elucidation

The structure of deacetylravidomycin M, an inhibitor of interleukin-4 signal transduction, was elucidated to be 6H-benzo[d]naphtho[1,2-b]pyran-6-one, 4-[3,6-dideoxy-3-(dimethylamino)-alpha-altropyranosyl]-1-hydroxy-10,12-dimethoxy-8-methyl- by spectroscopic studies including NMR measurements.

Role of protein kinase C in the reduction of infarct size by N-methyl-1-deoxynojirimycin, an alpha-1,6-glucosidase inhibitor

Preischaemic treatment with N-methyl-1-deoxynojirimycin (MOR-14), an alpha-1,6-glucosidase inhibitor, attenuates glycogenolysis and lactate accumulation during ischaemia and markedly reduces infarct size in rabbit hearts. In the present study, we have investigated whether protein kinase C (PKC), a principal mediator of ischaemic preconditioning, is also involved in the cardioprotective effect of MOR-14. To assess the effect of PKC inhibition on infarct size in MOR-14-treated hearts, 38 rabbits were subjected to 30 min of ischaemia followed by 48 h of reperfusion. Infarct size, as a per cent of area at risk, was significantly smaller in rabbits administered 100 mg kg(-1) of MOR-14 10 min before ischaemia (17+/-2%, n=10), than in a control group (46+/-5%, n=10). This beneficial effect of MOR-14 was abolished when 5 mg kg(-1) of chelerythrine, a PKC inhibitor, was given 10 min prior to MOR-14 injection (39+/-4%, n=10), although chelerythrine alone did not alter infarct size (43+/-4%, n=8). Further, chelerythrine had no effect on MOR-14-induced attenuation of glycogen breakdown and lactate accumulation in hearts excised at 30 min of ischaemia. Immunoblot analysis of PKC in homogenates of Langendorff-perfused rabbit hearts revealed that MOR-14 significantly increased levels of PKC-epsilon in the particulate fraction at 20 and 30 min of ischaemia and in the cytosolic fraction at 30 min of ischaemia. Taken as a whole, our data suggest that PKC acts downstream of the inhibition of glycogenolysis by MOR-14 to reduce infarct size. Thus, activation of PKC is a more direct mediator of the cardioprotection afforded by MOR-14 than is inhibition of glycogenolysis.

Clinical trial to investigate the pharmacokinetics, pharmacodynamics, safety, and efficacy of recombinant factor VIIa in Japanese patients with hemophilia with inhibitors

A multicenter and open-labeled clinical trial of human recombinant factor VIIa (rFVIIa) was conducted in Japanese patients with severe hemophilia A or B with inhibitors. The trial consisted of 2 parts. In study 1, the pharmacokinetics, pharmacodynamics, and safety of a single dose of 120 microg/kg of rFVIIa were investigated in 8 patients. In the subsequent study 2, the hemostatic effect and safety of rFVIIa were evaluated during a 24-week period in 10 patients. In study 1, the mean maximum FVII-coagulant activity (FVII:C) was found to occur after 10 minutes; activity then decreased rapidly and returned to the baseline within 24 hours after a single intravenous infusion of rFVIIa. The mean half-life of FVII:C was 3.5 hours. The activated partial thromboplastin time and prothrombin time in the patients were immediately shortened but returned to the baseline within 24 hours after dosing. In study 2, 86 microg/kg to 120 microg/kg of rFVIIa (mean, 97 microg/kg) was administered 1 to 85 times to 10 patients. A total of 58.0% (91/157) of bleeding episodes were treated excellently or effectively, with 5 (3.2%) ineffective episodes. There was no apparent trend in the relationship of the hemostatic effect with bleeding sites, mean dose, or number of injections. The efficacy rate, however, was significantly higher (90.0%) in bleeding episodes treated within 3 hours than in those treated at longer intervals (31.0%). No treatment-related adverse events were observed, and there was no evidence of antibody formation to rFVIIa. In conclusion. rFVIIa is an effective and well-tolerated option for treatment of bleeding episodes in hemophilia patients with inhibitors.

Reversibility of hepatic fibrosis: from the first report of collagenase in the liver to the possibility of gene therapy for recovery

Since the authors reported the presence of collagenase in the liver as well as its increased activity in the early stage of hepatic fibrosis and its reduced activity in advanced fibrosis in rats induced by chronic CCl4 intoxication, in baboons fed alcohol chronically and in patients with alcoholic fibrosis, other investigators have demonstrated the same tendency of collagenase activity biologically and histochemically. Very recently, the authors demonstrated definite gene expression of collagenase during the recovery from experimental hepatic fibrosis using Northern blotting and in situ hybridization. The findings of in situ hybridization not only demonstrated the cells expressing collagenase, but also suggested much information on the mechanism of the recovery from fibrosis. Hepatic stellate cells play a key role not only in fibrogenesis but also in fibrolysis. The authors' recent observation revealed that collagenase (matrix metalloproteinase-13 (MMP-13)) gene expression appears very early in the process of recovery from liver fibrosis, and that both stellate cells and hepatocytes express MMP-13. Recovery from liver cirrhosis requires the gene expression of collagenase, increased production of the collagenase enzyme, and activation of the enzyme balanced with the specific inhibitors of collagenase. The understanding of molecular mechanisms of MMP-1 gene expression which is under investigation in our laboratory may provide us a new strategy for the treatment of liver fibrosis including the possibility of gene therapy.

[The effect of the relative amount of sarcoplasmic reticulum Ca2+ -ATPase on the cardiac contractile and relaxation function]

Sarcoplasmic reticulum Ca(2+) -ATPase (SERCA2a) is a key protein which controls intracellular Ca(2+) concentration by virtue of its ability to take Ca(2+) up into sarcoplasmic reticulum. Recent genetic engineering enabled us to generate mice in which hearts have half copy of SERCA2a gene or excessive amount of SERCA2a transcripts. Depending on the amount of SERCA2a protein, hearts exhibited increased rate of Ca(2+) transport and thus quicker contraction and relaxation. These data suggest that the amount of SERCA2a protein is an important determinant of cardiac performances. These results lead us to develop the therapeutic strategy to increase SERCA2a protein to treat heart failure.

[Evaluation of the diagnostic reagents which detect rotavirus and adenovirus with the immunochromatographical method]

Dipstick 'Eiken' Rota and Dipstick 'Eiken' Adeno were the reagents used for the diagnosis of viral acute gastroenteritis using the immunochromatographical method. Dipstick 'Eiken' Rota and Dipstick 'Eiken' Adeno were evaluated for their sensitivity and specificity. Dipstick 'Eiken' Rota had a capacity to detect a purified rotavirus antigen in a concentration of 50 ng/ml. The sensitivity of Dipstick 'Eiken' Rota was 10 times higher than the sensitivity of the latex agglutination tests (Serodirect 'Eiken' Rota and ROTALEX DRY) and was almost the same as the immunochromatography test (Immu- noCard ST ROTAVIRUS) and the simplified EIA (TESTPACK ROTAVIRUS). With a concentration of 25 ng/ml, Dipstick 'Eiken' Adeno detected a purified adenovirus antigen. Dipstick 'Eiken' Adeno also detected adenovirus antigen in 64 higher dilutions than the latex agglutination test (ADENOLEX DRY). When Dipstick 'Eiken' Rota was compared with Serodirect 'Eiken' Rota among 100 fecal specimens of healthy children and children with viral acute gastroenteritis, the sensitivity was 100.0%, the specificity was 98.0%, and the agreement was 97.0%. When Dipstick 'Eiken' Adeno was compared with ADENOLEX DRY among 55 fecal specimens of healthy children and children with viral acute gastroenteritis, the sensitivity was 100.0 , the specificity was 93.8%, and the agreement was 96.4%. Dipstick 'Eiken' Rota and Dipstick 'Eiken' Adeno are found to be useful diagnostic assays for viral acute gastroenteritis in the clinical laboratories.

Ischemic preconditioning of rat livers against cold storage-reperfusion injury: role of nonparenchymal cells and the phenomenon of heterologous preconditioning

Brief periods of ischemia followed by reperfusion render tissues resistant against subsequent prolonged ischemia, a phenomenon called ischemic preconditioning. The effect of ischemic preconditioning on liver transplantation was investigated in relation to sinusoidal endothelial cell injury and Kupffer-cell activation, which are prominent features of storage and reperfusion injury leading to liver graft failure. Rat livers were preconditioned by 5 or 10 minutes of ischemia and 5 minutes of reperfusion and stored in University of Wisconsin (UW) solution for 30 hours. Livers were then reperfused for 15 minutes with physiological buffer containing trypan blue. Under these conditions, injury occurs predominantly to sinusoidal endothelial cells, reflected by trypan blue staining of nonparenchymal cells in histological sections. Ischemic preconditioning decreased nonparenchymal cell killing by more than 50%. When half the liver was preconditioned, sinusoidal endothelial cells were also protected in the contralateral half. Other stored livers were reperfused with nitroblue tetrazolium, which is converted to insoluble formazan by superoxide radicals. Ischemic preconditioning decreased the intensity of formazan deposition over Kupffer cells. Finally, stored livers were transplanted into nontreated rats. Ischemic preconditioning improved recipient long-term survival after 30 hours of cold ischemic storage in UW solution from 30% to 80% and decreased serum tumor necrosis factor-alpha levels in posthepatic blood 4 hours postoperatively from 98 to 54 pg/mL. In conclusion, ischemic preconditioning protects sinusoidal endothelial cells and suppresses Kupffer-cell activation after storage and reperfusion. As a result, graft survival improves after liver transplantation. Moreover, ischemia to half the liver confers protection to the other half. Such heterologous preconditioning provides a new means to protect liver tissue against ischemia-reperfusion injury without imposing ischemia on the target tissue.

[Transcriptional regulation of the sarcoplasmic reticulum Ca2+ -ATPase gene]

Sarcoplasmic reticulum Ca(2+)-ATPase is a key protein which takes Ca(2+) up into sarcoplasmic reticulum, thereby controls relaxation of cardiac muscle. The expression level of Ca(2+)-ATPase mRNA is regulated transcriptionally under various pathophysiological conditions. The E-Box, CArG Box, and MCAT element are essential for the muscle-specific transcription of the gene. Egr-1 sites in the proximal regulatory region of the gene are responsible for the decreased expression of Ca(2+)-ATPase mRNA in heart failure. Additionally, both proximal and distal regulatory elements are important for the transcriptional suppression of the gene.

Characterization of ultrastructure and its relation with DNA fragmentation in Fas-induced apoptosis of cultured cardiac myocytes

The purposes of the present study were to define precisely the ultrastructural features of apoptosis in cultured cardiomyocytes and to determine whether DNA fragmentation is essential for the apoptotic morphology. When cultured neonatal murine cardiomyocytes were incubated with an agonistic anti-Fas antibody in the presence of a non-toxic amount of actinomycin D or cycloheximide, approximately 70% of them had lost their viability after 24 h. The dead cardiomyocytes showed the typical ultrastructural changes of apoptosis on transmission and scanning electron microscopy, as well as by positive in situ nick end-labelling (TUNEL), positive Taq polymerase-based in situ ligation, a DNA ladder pattern on gel electrophoresis, and an increase in the active fragment of caspase-3. According to TUNEL at the electron microscopic level, apoptotic nuclear change, cytoplasmic shrinkage, and DNA fragmentation always occurred simultaneously in apoptotic cardiomyocytes. Other ultrastructural features of apoptosis were the appearance of abundant lipid-like structures in the cytoplasm of cardiomyocytes at the early phase, and a high incidence of plasma membrane rupture and formation of apoptotic bodies at the later phase. When zinc, an inhibitor of Ca2+/Mg2+-dependent endonuclease, was added to the present model, activation of caspase-3 and an apoptotic ultrastructure were still observed in spite of the lack of DNA fragmentation, indicating that this type of myocyte death is also apoptosis. In conclusion, the typical apoptotic ultrastructure and DNA fragmentation occur simultaneously in association with caspase-3 activation in Fas-stimulated cultured cardiomyocytes. Apoptotic morphology can, however, be observed even without DNA fragmentation.

Profilin I is essential for cell survival and cell division in early mouse development

Profilins are thought to play a central role in the regulation of de novo actin assembly by preventing spontaneous actin polymerization through the binding of actin monomers, and the adding of monomeric actin to the barbed actin-filament ends. Other cellular functions of profilin in membrane trafficking and lipid based signaling are also likely. Binding of profilins to signaling molecules such as Arp2/3 complex, Mena, VASP, N-WASP, dynamin I, and others, further implicates profilin and actin as regulators of diverse motile activities. In mouse, two profilins are expressed from two distinct genes. Profilin I is expressed at high levels in all tissues and throughout development, whereas profilin II is expressed in neuronal cells. To examine the function of profilin I in vivo, we generated a null profilin I (pfn1(ko)) allele in mice. Homozygous pfn1(ko/ko) mice are not viable. Pfn1(ko/ko) embryos died as early as the two-cell stage, and no pfn1(ko/ko) blastocysts were detectable. Adult pfn1(ko/wt) mice show a 50% reduction in profilin I expression with no apparent impairment of cell function. However, pfn1(ko/wt) embryos have reduced survival during embryogenesis compared with wild type. Although weakly expressed in early embryos, profilin II cannot compensate for lack of profilin I. Our results indicate that mouse profilin I is an essential protein that has dosage-dependent effects on cell division and survival during embryogenesis.

In situ EXAFS study on the formation of smectite-type clays containing cobalt cations in lattice

Smectite-type clays containing cobalt cations in octahedral sheets (MST (Co)) were prepared by a hydrothermal treatment of a water slurry of silicon-cobalt hydrous oxide prepared from water glass and cobalt chloride. The formation of silicate fragments having smectite-type structure was studied by EXAFS.

Primary hepatic choriocarcinoma--a case report

A 65-year-old man experienced anorexia and abdominal enlargement and died suddenly 45 days after admission. Multiple necrotic and hemorrhagic tumors were present in the liver (6 kg). The fragile tumor ruptured and a large amount of blood accumulated in the peritoneal cavity. The tumor was composed of cytotrophoblast and syncytiotrophoblast cells. Neoplastic cells were positive for human chorionic gonadotropin and negative for alpha-fetoprotein and carcinoembryonic antigen. The huge tumor directly invaded the entire antrum of stomach. Neoplastic trophoblastic cells proliferated mainly in the serosa and propria muscular layer of the stomach, and tiny cancer nests were observed in many vessels of the submucosa and propria mucosa. The serum alpha and beta human chorionic gonadotropin subunits showed a very high level; 51 ng/mL and 820 ng/mL, respectively. No tumor, cyst or scar was observed in the testes, mediastinum and retroperitoneum, macroscopically and microscopically. Based on these autopsy findings, we diagnosed this patient as having primary hepatic choriocarcinoma.

In situ EXAFS study on nickel metal particles dispersed on Loy Yang brown coal

The structure of nickel catalysts supported on Loy Yang brown coal by an ion-exchanging method during thermal treatment was studied by a XAFS technique. The exchanged nickel species aggregated to metal particles during pyrolysis and hydrogasification. The aggregation behaviour of nickel species depended on the amount of nickel loaded and/or treatment atmospheres.

Adrenergic stimulation of osteoclastogenesis mediated by expression of osteoclast differentiation factor in MC3T3-E1 osteoblast-like cells

It is well known that adrenergic agonists efficiently activate beta-adrenoceptors on osteoblastic cells and can stimulate bone resorption in intact mouse calvaria. Recently, an osteoclastogenic factor of osteoblastic origin was found to be a novel tumor necrosis factor ligand family member and was termed osteoclast differentiation factor (ODF). Using a reverse transcription-polymerase chain reaction approach, we investigated the effect of epinephrine on mRNA levels of ODF and its decoy receptor, osteoclastogenesis inhibitory factor (OCIF), in MC3T3-E1 cells. Treatment with epinephrine (1 microM) rapidly increased ODF and OCIF mRNA levels, which peaked after 0.5 hr of treatment. Epinephrine (1 microM) also increased interleukin (IL)-6, IL-11, and cyclooxygenase (COX)-II mRNA levels, as well as increased prostaglandin E(2) (PGE(2)) accumulation in the culture medium. Treatment of the cells with IL-11 (10 ng/mL) or PGE(2) (1 microM) increased ODF and OCIF mRNA levels as observed with epinephrine. However, increases in ODF and OCIF mRNA levels by epinephrine were more rapid than those by IL-11, and were not influenced by NS-398 (100 microM; an inhibitor of COX-II), suggesting a direct effect of epinephrine on ODF and OCIF mRNA expressions as well as an indirect effect mediated by IL-11 and PGE(2) production. Epinephrine-induced increases in ODF and OCIF mRNA levels were inhibited by pretreatment with timolol (1 microM; beta-antagonist) and phentolamine (1 microM; alpha-antagonist), respectively. Furthermore, the formation of tartrate-resistant acid phosphatase-positive multinucleated cells from mouse bone marrow cells was stimulated by isoproterenol (0.1 to 10 microM) or epinephrine (0.1 to 10 microM). The action of isoproterenol, a beta-agonist, was clearly stronger than that of epinephrine, suggesting the importance of the physiological balance between ODF and OCIF productions for osteoclastogenesis. These findings suggest that beta-adrenergic stimulation induces not only IL-6, IL-11, and PGE(2) but also ODF expression in osteoblastic cells, leading to a stimulation of osteoclastogenesis.

Role of protein kinase C, K(ATP) channels and DNA fragmentation in the infarct size-reducing effects of the free radical scavenger T-0970

1. In the present study, we investigated the effect of 1-(3-tert-butyl-2-hydroxy-5-methoxyphenyl)-3-(3-pyridylmethyl) urea hydrocloride (T-0970), a novel water-soluble low-molecular weight free radical scavenger, on the generation of hydroxyl radicals in vivo and on myocardial infarct size in an in vivo model of myocardial infarction in rabbits. 2. T-0970 scavenged hydroxyl radicals generated in the myocardium during reperfusion, as assessed by using a microdialysis technique and HPLC in an in vivo model with 30 min coronary occlusion and 30 min reperfusion in rabbits. 3. Another group of rabbits was subjected to 30 min coronary occlusion and 48 h reperfusion. The control group (n = 10) was infused with saline for 190 min from 10 min before occlusion to 180 min after reperfusion. The treatment group (T-0970 group; n = 10) was injected with a bolus 2.5 mg/kg T-0970 and then infused with T-0970 for 190 min from 10 min before reperfusion to 180 min after reperfusion at a rate of 100 microg/kg per min. The T-0970 + CHE group (n = 5) was given chelerythrine (CHE; a selective inhibitor of protein kinase C (PKC); 5 mg/kg, i.v.) 10 min before the administration of T-0970. The T-0970 + 5-HD group (n = 5) was given 5-hydroxydecanoate (5-HD; an inhibitor of mitochondrial K(ATP) channels; 5 mg/kg, i.v.) 10 min before the administration of T-0970. The CHE and 5-HD groups were given CHE (5 mg/kg, i.v.) and 5-HD (5 mg/kg, i.v.) 20 min before reperfusion, respectively. After 48 h reperfusion, infarct size was measured histologically and expressed as a percentage of the area at risk (AAR). In another series of experiments, the control (n = 5) and T-0970 (n = 5) groups were killed 4 h after reperfusion following 30 min coronary occlusion and DNA fragmentation in myocytes was assessed using in situ dUTP nick end-labelling (TUNEL) at the light microscopic level. 4. Infarct size, as a percentage of AAR, in the T-0970 group was significantly reduced compared with the control group (21+/-4 vs 41+/-4%, respectively; P<0.05). This reduction of infarct size by T-0970 was abolished by pretreatment with CHE and 5-HD. Neither CHE nor 5-HD alone had any effect on infarct size. The percentage of infarcted myocytes with DNA fragmentation by TUNEL in the T-0970 group was significantly reduced compared with the number in the control group (4.0+/-1.5 vs 10.7+/-1.9%, respectively; P<0.05). 5. T-0970, a free radical scavenger, improved reperfusion injury. This effect seemed to be mediated by activation of PKC, the opening of mitochondrial K(ATP) channels and inhibition of DNA fragmentation.

Reduced fimbria-associated activities of Porphyromonas gingivalis induced by recombinant fimbrial expression

The adhesion properties of the recombinant fimbriae (r-fimbriae) recovered from a YH522 transformant of Porphyromonas gingivalis which harbors a chimeric plasmid, pYHF2, containing the fimA gene of strain 381 were compared with those of the endogenous fimA fimbriae of strain 33277. The adhesion level of the r-fimbriae to Actinomyces viscosus was clearly lower than that of the endogenous fimbriae. In addition, the r-fimbriae were shown to lack some minor components detectable in the endogenous fimbriae. The plasmid pYHF2 prepared from the YH522 transformant was then transformed into six different P. gingivalis strains and the resultant pYHF2-containing strains were examined for their fimbrial expression. In spite of the presence of a considerable diversity in the expression level of the r-fimbriae among these transformants, it was evident that the strains expressing higher levels of the r-fimbriae exhibited a greater decrease in adhesion activity to other bacteria and to oral epithelial cells, as well as in self-aggregation.

Juxtamembrane region of the amino terminus of the corticotropin releasing factor receptor type 1 is important for ligand interaction

The functional properties of the amino terminus (NT) of the corticotropin releasing factor (CRF) receptor type 1 (R1) were studied by use of murine (m) CRFR1 and rat (r) parathyroid hormone (PTH)/parathyroid hormone-related peptide receptor (PTH1R) chimeras. The chimeric receptor CXP, in which the NT of mCRFR1 was annealed to the TMs of PTH1R, and the reciprocal hybrid, PXC, bound radiolabeled analogues of sauvagine and PTH(3--34), respectively. Neither hybrid bound radiolabeled CRF or PTH(1--34). CRF and PTH(1--34) weakly stimulated intracellular cAMP accumulation in COS-7 cells transfected with PXC and CXP, respectively. Thus the NT is required for ligand binding and the TMs are required for agonist-stimulated cAMP accumulation. Replacing individual intercysteine segments of PXC with their mCRFR1 counterparts did not rescue CRF or sauvagine radioligand binding or stimulation of cAMP accumulation. Replacement of residues 1--31 of mCRFR1 with their PTH1R counterparts resulted in a chimeric receptor, PEC, which had normal CRFR1 functional properties. In addition, a series of chimeras (F1PEC--F6PEC) were generated by replacement of the NT intercysteine residues of PEC with their PTH1R counterparts. Only F1PEC, F2PEC, and F3PEC showed detectable CRF and sauvagine radioligand binding. All of the PEC chimeras except F5PEC increased cAMP accumulation. These data indicate that the Cys(68)(-)Glu(109) domain is important for binding and that the Cys(87)(-)Cys(102) region plays an important role in CRFR1 activation.

Characterization of three corticotropin-releasing factor receptors in catfish: a novel third receptor is predominantly expressed in pituitary and urophysis

The present study reports the isolation of three complementary DNA (cDNA) clones encoding distinct subtypes of CRF receptors from the diploid catfish (cf) species, Ameiurus nebulosus. The first clone encodes a 446-amino acid protein (cfCRF-R1) that is highly homologous to mouse (m) CRF-R1 (93% identical). The cfCRF-R1 messenger RNA is highly expressed in the brain, and its distribution pattern correlates well with that of mammalian CRF-R1, except for weak expression in the pituitary. When transiently expressed in COS-7 cells, cfCRF-R1 bound CRF, urotensin I, and sauvagine with similar affinities. The second full-length cDNA, which was cloned from catfish heart, encodes a 406-amino acid protein that showed homology to murine CRF-R2 (88%) and when expressed in COS-7 cells preferentially bound sauvagine. The highest level of cfCRF-R2 expression was observed in the heart. The third full-length cDNA clone, which encodes a 428-amino acid protein, is structurally closer to cfCRF-R1 (85%) than to cfCRF-R2 (80%). This novel CRF receptor (cfCRF-R3) bound CRF with a 5-fold higher affinity than urotensin I and sauvagine and was expressed in the pituitary gland, urophysis, and brain. The presence of three different CRF receptors, each with distinct tissue distribution and ligand binding properties, suggests a complex CRF/urotensin I system.

Expression of a gene encoding chitinase (pCA 8 ORF) from Aeromonas sp. no. 10S-24 in Escherichia coli and enzyme characterization

A gene encoding chitinase from Aeromonas sp. no. 10S-24 was expressed using pTrc99A in Escherichia coli JM 105 which yielded a 5-fold higher activity than when pUC19 was used. Three different truncated enzymes (SA-1, SA-2 and SA-3) were obtained after purification. Their isoelectric points were 7.0, 6.9, and 6.7, respectively. The enzymes showed two optimum pHs, 4.0 and 7.0, when incubated with ethylene glycol chitin as the substrate, and were stable over a wide pH range (3.0-9.0). The optimum temperature was 60 degrees C and the enzymes were stable up to 50 degrees C. The chitinases exhibited wide substrate specificities for chitin-related compounds.

Folding-unfolding of goat alpha-lactalbumin studied by stopped-flow circular dichroism and molecular dynamics simulations

Folding reaction of goat alpha-lactalbumin has been studied by stopped-flow circular dichroism and molecular dynamics simulations. The effects of four single mutations and a double mutation on the stability of the protein under a native condition were studied. The mutations were introduced into residues located at a hydrophobic core in the alpha-domain of the molecule. Here we show that an amino acid substitution (T29I) increases the native-state stability of goat alpha-lactalbumin against the guanidine hydrochloride-induced unfolding by 3.5 kcal/mol. Kinetic refolding and unfolding of wild-type and mutant goat alpha-lactalbumin measured by stopped-flow circular dichroism showed that the local structure around the Thr29 side chain was not constructed in the transition state of the folding reaction. To characterize the local structural change around the Thr29 side chain to an atomic level of resolution, we performed high-temperature (at 400 K and 600 K) molecular dynamics simulations and studied the structural change at an initial stage of unfolding observed in the simulation trajectories. The Thr29 portion of the molecule experienced structural disruption accompanied with the loss of inter-residue contacts and with the water molecule penetration in the 400-K simulation as well as in four of the six 600-K simulations. Disruption of the N-terminal portion was also observed and was consistent with the results of kinetic refolding/unfolding experiments shown in our previous report.