[Value of 123I-BMIPP scintigraphy in patients with ischemic heart disease: comparison with exercise 201Tl SPECT]

To evaluate 123I labeled beta-methyl-branched fatty acid (BMIPP) myocardial uptake at rest in the segment with and without stress induced ischemia in patients with coronary artery disease, 123I-beta-methyl-branched fatty acid myocardial scintigraphy was performed at rest and was compared with the findings of stress-reinjection 201Tl myocardial scintigraphy in 31 patients with coronary artery disease. In 159 ischemic myocardial segments, equally decreased uptake on both reinjection 201Tl and fatty acid images was observed in 64 segments, more severely decreased uptake of fatty acid in 76 segments, and more severely decreased uptake of reinjection thallium in 19 segments. On the other hand, in 53 non-reversible defects, each patterns was observed in 41, 3, and 9 segments respectively. When comparing the ischemic segments with more reduced uptake of fatty acid than reinjection thallium (Group 1) and the ischemic segments with equally or less reduced fatty acid uptake than reinjection thallium (Group 2), wall motion was more severely impaired in Group 1 than in Group 2 (severe hypo- to dyskinesis was present in 32 of 54 segments in group 1 and in 21 of 75 segments in group 2, p < 0.005). In conclusion, in patients with coronary artery disease, resting fatty acid uptake was frequently more reduced than reinjection 201Tl in the segments with stress induced ischemia and wall motion was more impaired in these segments. BMIPP myocardial imaging may provide information on metabolic alterations at rest independent of perfusion abnormalities in patients with coronary artery disease.

A direct role of transcription factor E2F in c-myc gene expression during granulocytic and macrophage-like differentiation of HL60 cells

The transcription factor E2F is known to play an important role in cell cycle progression through interaction with retinoblastoma protein. HL60 cells are able to differentiate into a granulocytic lineage by prolonged exposure to retinoids and into a macrophage-like lineage by exposure to tumor promoter 12-O-tetradecanoylphorbol 13-acetate, with a rapid decrease of c-myc gene expression. In this study, we assessed the changes of the E2F-binding pattern to the P2 promoter region of the c-myc gene during differentiation into both lineages. The observed changes of the E2F-binding pattern were a decrease of free E2F and an appearance of retinoblastoma protein-containing E2F complexes in both lineages. The effects of the anti-c-myc antibody and the recombinant c-Myc protein on the E2F-binding patterns suggest that the c-Myc protein is not involved directly in these changes. These changes also led the suppression of transcriptional initiation from the P2 promoter. The results indicate that, in the course of HL60 cell differentiation, E2F plays a direct role in the transcriptional control of the c-myc gene through interaction with the retinoblastoma protein. A potential role for the c-Myc protein is discussed in relation to an existing state of E2F and E2F-RB complexes in the HL60 cells.

Biochemistry and functions of hepatitis B virus X protein

Hepatitis B virus X gene codes for a small basic cytoplasmic protein and is able to transactivate viral and cellular genes, although X protein exhibits no DNA-binding activity. The mechanism of transactivation by X protein has been suggested to be via protein-protein interaction(s). X protein had amino acid sequences homologous to the functionally essential domain of Kunitz-type serine protease inhibitors, and these sequences were indispensable for transactivation function. X protein activated X-gene transcription itself and an X-responsive element were localized in their minimal promoter. Furthermore, tumor suppressor gene product p53, but not mutant p53, repressed X-gene transcription from the minimal promoter, indicating that X protein disrupts the function of normal p53, which represses transcription of X gene or cellular gene. Data suggest that inhibition of a hepatic serine protease by X protein leads to eliminate the suppressor effect of p53 on the basic transcription machinery in nucleus.

Effects of maternal administration of dexamethasone and thyrotropin-releasing hormone on fetal rat pulmonary surfactant synthesis

To determine the effects of maternal administration of dexamethasone (DEX) and thyrotropin-releasing hormone (TRH) on fetal lung maturation, 16 pregnant rats were divided into the following four groups: 20 micrograms/kg TRH twice a day was given intraperitoneally to the TRH group rats, 0.5 mg/kg/day DEX to the DEX group and both DEX and TRH to the DEX + TRH group for 3 consecutive days from gestational day 17. The control rats were given an equivalent volume of saline. The pregnant rats were sacrificed on gestational day 20 and the fetal lungs were removed. The relative amounts of surfactant protein A (SP-A), B (SP-B) and C (SP-C) mRNAs were analyzed by Northern blotting and the total lung disaturated phosphatidylcholine (DSPC) contents were determined using an enzymatic method. The SP-B and -C mRNA and DSPC contents in the DEX and DEX + TRH groups were significantly higher than those in the control group, whereas the SP-A mRNA levels did not differ significantly among the four groups. The SP-B and -C mRNA and DSPC contents in the DEX and DEX + TRH groups did not differ significantly. These findings suggest that TRH has no effects on the regulation of surfactant protein mRNAs or DSPC contents in the fetal rat lung and has no additive effects when combined with DEX.

Effects of alcohol ingestion on vestibular function in postural control

In order to define the acute effects of a moderate quantity of alcohol on balance, related to the vestibular function, vestibulo-ocular reflex (VOR) test, caloric test and dynamic posturography (EquiTest) were performed. Ten healthy male volunteers aged 19-27 average 22.8) years old imbibed 1.5 ml whisky (alcohol content 43%) per kilogram of body weight within 5 min. Blood alcohol level (BAL) was measured before administration and then after 30, 90, and 150 min. Equilibrium examinations were performed immediately after each blood sample was taken. At the highest alcohol level, significant reductions were found in VOR gain, in the maximum slow-phase velocity of the caloric test and in the equilibrium score of the sensory organization test in condition 5, when compared with those before drinking. In some typical cases, the subjects' response in all tests were most disturbed at the time when the highest alcohol level was measured. From our results, we conclude that a moderate quantity of alcohol affects not only the oculomotor system but also the vestibular system. Furthermore, it was suggested that one of the reasons for postural instability after drinking alcohol may be reduced vestibular function.

Three sites of the hepatitis B virus X protein cooperatively interact with cellular proteins

The X protein of hepatitis B virus is known to be a trans-activator of viral and cellular genes and to be a serine protease inhibitor as well. X protein has no DNA-binding activity, but is postulated to exert its trans-activation function by interacting with cellular proteins. To investigate interaction sites of X protein with cellular proteins, we carried out an immunoprecipitation inhibition assay using several different anti-X antibodies in the presence or absence of cellular proteins. Results elucidated three separate sites (aa 65-72, aa 105-115, and aa 131-142; U22, X1, and Z44 sites, respectively) of the X protein that cooperatively interacted with cellular proteins. Analyses with a series of mutant X proteins also supported the interactions at the U22, X1, and Z44 sites. Based on the CAT activity assay, the essential regions for the trans-activation function of X protein overlapped with these three interaction sites. Furthermore, these interaction sites also coincide with the structures necessary for the serine protease inhibitor activity. Thus, the trans-activation function and serine protease inhibitor activity of X protein may be exerted by interaction with cellular proteins through at least these three sites.

Role of nuclear histone-H1 kinase in regeneration of rat liver

The activities of nuclear histone-H1 kinase and C-kinase as well as the amount of phosphate bound to histone-H1 following partial hepatectomy were studied in rat. It was found that the nuclear histone-H1 kinase activity increased twice within 80 h, first 20 to 30 h, and second at 50 to 70 h after partial hepatectomy. The timing of increase of the enzyme activity correlated with increased amount of bound phosphate. On the other hand, the increase of the C-kinase activities occurred between 5 and 15 h after partial hepatectomy. Antibodies raised against human cdk2, human cyclin-A and mouse cdc2 kinase showed no detectable effect on the nuclear histone H1 kinase activity. These results suggest that phosphorylation of histone-H1 in liver regeneration may be catalysed by a putative kinase(s).

Experimental control of axial pattern in the chick blastoderm by local expression of Wnt and activin: the role of HNK-1 positive cells

Small grafts from transfected mammalian cell lines that secrete activin or express Wnt-1 RNA were made to the marginal zone of entire chick blastoderms in culture. Grafts from appropriate control cell lines produced no effects on development. The activin-secreting grafts, implanted before streak formation, could cause the streak to form opposite their marginal position even when this was 180 degrees distant around the blastoderm from the original presumptive streak site. Alternatively, opposed twin streaks were observed, one at the original presumptive site and one in relation to the graft. Wnt-expressing grafts implanted early could also reposition axis formation, but only to graft sites within approximately 100 degrees of angular distance from the host's presumptive streak origin. No Wnt-induced twinning was observed. Grafts of both experimental cell types intermixed were the most effective in reorientating, twinning, or globally disturbing the axial pattern and led to second axes with the least delay, relative to normal development, in reaching headfold stages. The incidence and distribution of cells positive for the epitope HNK-1 was investigated during early stages of normal and of experimentally twinned development. Only two nonhypoblast regions of HNK-1 expression were consistently observed in normal early development; a sector in the germ wall area opaca, behind the site of streak formation, and then a localised region of intensely, newly expressing cells arising in epiblast and in anteriormost parts of the (epiblast-derived) streak at the half-length streak stage. Both "activin only" and "activin/Wnt" mixed grafts, although not control grafts, became surrounded by new sectors of "germ wall" HNK-1 positivity. Such positivity may therefore mark a cell group with a signaling role (but no anatomical participation) in streak initiation. However, there was no change of the local background incidence of epiblastic HNK-1 positivity in the structure of streaks induced by "activin only" grafts. This indicates that most cells of the streak are specified by relatively local induction, rather than deriving from selective aggregation. Only grafts including the Wnt-expressing cells gave rise to obvious new HNK-1 expression within epiblast-derived cells anteriorly, as does the complete normal streak. This suggests that the Wnt class of response pathway can complement the activin one in producing rostrocaudally complete axial pattern, as has been suggested for amphibian development.

Occupational exposure to solvent mixtures: effects on health and metabolism

Exposure monitoring by personal diffusive samplers, biological monitoring of toluene exposure by urinary hippuric acid determination, haematology, serum biochemistry for liver function, and a subjective symptom survey by questionnaire were conducted on 303 male solvent workers. They were exposed to a mixture of solvents including toluene (geometric mean 18 ppm), methyl ethyl ketone (MEK; 16 ppm), isopropyl alcohol (IPA; 7 ppm), and ethyl acetate (9 ppm). The intensity was mostly below unity using the additiveness formula based on current Japanese occupational exposure limits, but more than eight times unity at the maximum. The results were compared with the findings in 135 non-exposed male workers of similar ages. Haematology and liver function tests did not show any exposure related abnormality, and subjective symptoms were mostly related to central nervous system depression and local irritation. Further analysis suggested that the irritation effects were not related to exposure to MEK. Analysis of the relation between toluene exposure and hippuric acid excretion in urine showed that there was no metabolic interaction between MEK and toluene, or between IPA and toluene. Overall, therefore, it is concluded that there was no sign or symptom detected to suggest anything other than toluene toxicity, that there was no evidence to indicate any modification of toluene toxicity or metabolism due to coexposure, and that the additiveness assumption is reasonable for risk assessment for the combination of solvents under these exposure conditions.

The WD gene for Wilson's disease links to the hepatitis of LEC rats

LEC rats develop an autosomal recessive hepatitis and subsequently liver cancer associated with copper accumulation in the liver similar to that of Wilson's disease. Using 71 backcross [(WKAH x LEC) x LEC] rats, linkage analysis of the hepatitis with the WD gene for Wilson's disease revealed identical segregation and no recombination event between these two genes. This result indicates that the WD gene is a prime candidate for the hts gene responsible for the hepatitis of LEC rats, and suggests that the hepatitis of LEC rats may be caused by a defect in a copper-transporting ATPase expressed in the liver.

Functional reconstitution of Chlamydomonas outer dynein arms from alpha-beta and gamma subunits: requirement of a third factor

The outer dynein arm of Chlamydomonas flagella, when isolated under Mg(2+)-free conditions, tends to dissociate into an 11 to 12S particle (12S dynein) containing the gamma heavy chain and a 21S particle (called 18S dynein) containing the alpha and beta heavy chains. We show here that functional outer arms can be reconstituted by the addition of 12S and 18S dyneins to the axonemes of the outer armless mutants oda1-oda6. A third factor that sediments at integral 7S is required for efficient reconstitution of the outer arms on the axonemes of oda1 and oda3. However, this factor is not necessary for reconstitution on the axonemes of oda2, oda4, oda5, and oda6. SDS-PAGE analysis indicates that the axonemes of the former two mutants lack a integral of 70-kD polypeptide that is present in those of the other mutants as well as in the 7S fraction from the wild-type extract. Furthermore, electron micrographs of axonemal cross sections revealed that the latter four mutants, but not oda1 or oda3, have small pointed structures on the outer doublets, at a position in cross section where outer arms normally occur. We suggest that the 7S factor constitutes the pointed structure on the outer doublets and facilitates attachment of the outer arm. The discovery of this structure raises a new question as to how the attachment site for the outer arm dynein is determined within the axoneme.

[Aging changes of cerebral high intensity areas on T2-weighted MRI--a study in medical checkup patients]

To determine normal aging process of the brain, cerebral T2-weighted MRI was evaluated in 400 healthy individuals who visited our hospital for routine medical checkups. The results are summarized as follows. 1) High intensity areas (measuring 2 mm x 2 mm or more) were observed most frequently in the cerebral white matter including the corona radiata (CR). The incidence of these areas increased linearly with age, and approached about 50% in the patients of the seventh decade. 2) High intensity areas in the basal ganglia (BG) were the second commonest. High intensity areas were rarely seen in the thalamus (TH) and pontine base (PO). 3) High intensity areas were confined to the CR (66.9%) in the majority of the cases, while there were few cases having these areas restricted to the BG, TH and PO; that is, most of them were accompanied by additional high intensity areas in the CR. 4) Periventricular hyperintensity areas increased in size with age, and were prominent in those who had multiple or large high intensity areas in the CR, or those who had signal hyperintensity in the BG, TH or PO.

Clinical study of azoospermia

This study evaluated how many patients with azoospermia might have fertility potential using assisted conception techniques. A total of 102 male patients with azoospermia were included in the study. Thirteen patients had sex chromosomal abnormalities. Testicular biopsy performed in the other 89 patients showed incomplete spermatogenesis in 47 of them whereas 42 had complete spermatogenesis. In the latter 42 patients, distal vasography demonstrated bilateral obstruction of the excurrent ducts in 14 patients whereas no distal obstruction of the ducts was found in 28. The 89 patients were divided into three groups according to the findings of testicular biopsy and distal vasography. In the 14 patients with both complete spermatogenesis and distal obstruction of the excurrent ducts, surgical procedures are applicable. The pathogenesis of the 28 patients with complete spermatogenesis but without distal obstruction of the ducts should be clarified for further treatment.

New dihydropyridine calcium channel antagonist, pranidipine, attenuates hypertensive renal injury in Dahl salt-sensitive rats

Interest in the cardiovascular protective effects of calcium channel antagonists has increased in the past decade. We investigated prevention of vascular wall remodeling by the long-acting calcium channel antagonist pranidipine in 12-week-old Dahl salt-sensitive (SS) rats with high-salt-induced (4% NaCl) hypertension. Six-week pranidipine treatment (60 mg/kg chow) decreased systolic blood pressure (SBP) by 22% in SS rats. This BP reduction was associated with decreases in cardiac mass and weight of the aortic wall. Glomerular filtration rate (GFR) was increased by 33%, but this did not lead to a decrease in urinary protein or NAG excretion. Morphologic investigation demonstrated striking resolution of arterial injury (medial necrosis and/or hyperplasia, inflammatory cell infiltration, and thrombus formation) by 87% after pranidipine treatment. Glomerular sclerosis was also attenuated by 61%, whereas tubular injury was improved by only 28%. These morphologic changes were reflected in the findings that the capacity of kidney homogenate for generating lipid peroxides was significantly decreased and that collagen levels and pattern type became similar to those of normotensive salt-resistant (SR) rats. Pranidipine also attenuated hypertensive vasculopathy in small arteries of the middle cerebral arteries. Thus, the calcium channel antagonist pranidipine can attenuate the vascular injury that occurs in salt-induced hypertension, a promising property that implicates its clinical usage, particularly in essential hypertension with cardiovascular complications.

Vasoconstrictors and renal protection induced by beta 1-selective adrenoceptor antagonist bisoprolol

We investigated the role of the vasoconstrictors endothelin-1 (ET-1) and thromboxane in renal protection by the beta 1-selective adrenoceptor antagonist, bisoprolol, in Dahl salt-sensitive rats (Dahl S) and salt-resistant rats (Dahl R). Six-week bisoprolol treatment (20 mg/kg chow) reduced systolic blood pressure (SBP) by 14% in Dahl S rats fed a high-salt (4% NaCl) diet. This BP reduction was accompanied by a decrease in aortic wall thickness. ET-1 and thromboxane released from renal cortex was significantly decreased by 17 and 30% with bisoprolol, respectively. Other prostaglandin synthesis was unaffected. Renal function such as proteinuria, N-acetyl-beta-D-glucosaminidase (NAG) excretion, and glomerular filtration rate (GFR) was not influenced by bisoprolol. Morphologic investigation showed that bisoprolol significantly improved glomerular sclerosis by 29% and attenuated arterial damage by 71%, although tubular injury was not affected. The more severe the glomerulosclerotic lesions, the greater the generation of thromboxane and ET. The arterial lesions were positively correlated to thromboxane generation. These data indicate that long-term bisoprolol treatment reduces vasoconstrictive ET-1 and thromboxane generation and that these alterations may be partly responsible for the amelioration of glomerular and arterial injury in Dahl S rats.

Comparison of lesions induced by intra-articular injections of quinolones and compounds damaging cartilage components in rat femoral condyles

Twenty-five microliters of a 2% saline solution of levofloxacin (LVFX) or ciprofloxacin (CPFX) was injected every other day for 2 wk into the knee joint space of CD rats (weighing 62.7-86.7 g) from the age of 3 wk. Early in the course of injection, histologic examination revealed chondrocyte necrosis without marked matrix change in the articular cartilage of the femoral condyles adjacent to the intercondylar groove. After 7 injections, the surface and intermediate zones of the articular cartilage showed extensive necrosis, sometimes with cavity formation in the center of the same portion. Papain completely depleted matrix basophilia in all zones throughout the condyle and caused cartilage necrosis with cavity formation. One injection of iodoacetic acid caused necrosis of almost all chondrocytes over the entire condyle, but chondrocytes sometimes remained alive in the portion where cavity formation was induced by quinolones. Chondroitinase depleted the matrix basophilia, and sometimes produced necrotic areas. DNA synthesis inhibitors n-ethylmaleimide, CPT-11, and etoposide (VP-16) caused chondrocyte necrosis, but never caused cavities in the articular cartilage. The DNA synthesis inhibitors n-ethylmaleimide, CPT-11, and hydroxyurea were administered concurrently with po LVFX administration and significantly increased the incidence of LVFX-induced cavity formation. n-Ethylmaleimide was the most effective of all the inhibitors. The quinolone-induced cavity formation is suggested to be site specific in the articular cartilage of rat femoral condyles. The depletion of matrix proteoglycans and chondrocyte necrosis may be necessary, although insufficient, to produce such lesions. Disruption of the collagen framework is suspected to contribute to their development. Involvement of altered DNA metabolism may play a role in the chondrocyte necrosis that occurs early in the specific sites.

Quantitative analysis of genomic polymorphism of herpes simplex virus type 1 strains from six countries: studies of molecular evolution and molecular epidemiology of the virus

Using the presence or absence of 63 variable restriction endonuclease (RE) sites selected from 225 sites with six REs, genomic polymorphism of 242 herpes simplex virus type 1 (HSV-1) strains from six countries (Japan, Korea, China, Sweden, U.S.A. and Kenya) was quantitatively analysed. Twenty-five of the 63 sites were found to differ between Korean and Kenyan strains. In contrast, only three and six sites were found to differ between isolates from Sweden and the U.S.A. and between those from Korea and China, respectively, suggesting that they are closely related to each other. In this way, characterization of 63 sites enabled us to categorize 186 distinct HSV-1 genotypes from 242 individuals. Some strains from Japan, Korea and China shared the same genotypes, indicating that they are phylogenetically closely related. Many significant correlation coefficients (magnitude of > 0.42; P < 0.01) between pairs of sites were found in isolates from the three Asian countries (Japan, Korea and China) as well as in those from Sweden and the U.S.A., suggesting that HSV-1 strains from within the same ethnic groups are evolutionarily closer. The average number of nucleotide substitutions per nucleotide, as defined by nucleotide diversity (pi), was estimated for HSV-1 genomes within (pi x or pi y) and between (pi xy) countries. On the basis of 225 sites, nucleotide diversity for Kenyan isolates was 0.0056, almost three times higher than that for Korean isolates, implying that Kenyan HSV-1 genomes are much more diverse than those from Korea. In addition, the diversity between HSV-1 isolates from different countries (pi xy) was highest between isolates from the three Asian countries and Kenya (0.0075 to 0.0081) and lowest among those from the three Asian countries (0.0032 to 0.0040). The mutation rate (lambda) for HSV-1 was estimated to be 3.5 x 10(-8)/site/year. All these findings show that the evolution of HSV-1 may be host-dependent and very slow.

Transcription from the P2 promoter of human protooncogene myc is suppressed by retinoic acid through an interaction between the E2F element and its binding proteins

When human promyelocytic leukemia cell line HL60 was treated with retinoic acid (RA), considerable suppression of protooncogene myc expression was achieved before granulocytic differentiation became evident. From transient transfection experiments using the reporter plasmid containing exon 1 and its 2.3 kilobases upstream of the c-myc gene fused to the chloramphenicol acetyltransferase gene, it was indicated that this suppression was mainly attributable to the level of transcription initiation. Deletion down to 95 base pairs upstream of the P2 promoter did not change the suppressive effect of RA on c-myc gene expression. Mobility shift assays with respect to the P2 promoter region revealed that the 15-base pair fragment located between P1 and P2 promoters was responsive to the RA treatment. This fragment included the E2F binding site in the c-myc P2 promoter region, and a difference of shifted bands between RA-treated and untreated HL60 cells was due to complex formation of E2F and retinoblastoma protein. The present results suggest that E2F plays an important role in the process of cell differentiation by RA and that a change of the E2F binding pattern induced by RA contributes to the suppression of c-myc gene expression preceding granulocytic differentiation.

A case of recurrent intramural uterine stromal tumor with epithelial differentiation effectively treated with oral low-dose administration of etoposide

A 66-year-old woman was diagnosed as having myoma of the uterus and total hysterectomy with bilateral salpingo-oophorectomy was performed. The histopathological findings were puzzling, and the case was finally diagnosed as intramural uterine stromal tumor with epithelial differentiation. Three years after the operation, a firm tumor developed in the pelvic cavity. Laparotomy failed to remove the tumor and neither CAP (cyclophosphamide 500 mg, adriamycin 50 mg, CDDP 70 mg) therapy nor radiation therapy was effective. Oral administration of etoposide (25 mg/day), however, showed PR (50% decrease) as determined by CT scanning, and ultrasonography, and no metastatic lesions were found. This tumor was coincident with the endometrial stromal tumor with epithelial elements classified by Clement and Scully. The histological feature of the tumors and the efficacy of oral etoposide therapy are discussed in this study.