Effects of thromboxane A2 analogue on vascular resistance distribution and permeability in isolated blood-perfused dog lungs

This study was designed to determine the effects of thromboxane A2 (TxA2) on the distribution of vascular resistance, lung weight, and microvascular permeability in isolated dog lungs perfused at a constant pressure with autologous blood. The stable TxA2 analogue (STA2; 30 micrograms, n = 5) caused an increase in pulmonary capillary pressure (Pc) assessed as double-occlusion pressure to 14.0 +/- 0.4 mmHg from the baseline of 7.9 +/- 0.3 mmHg with progressive lung weight gain. Pulmonary vascular resistance increased threefold exclusively due to pulmonary venoconstriction. Pulmonary venoconstriction was confirmed in lungs perfused in a reverse direction from the pulmonary vein to the artery (n = 5), as evidenced by marked precapillary vasoconstriction and a sustained lung weight loss. Furthermore, in lungs perfused at a constant blood flow (n = 5), STA2 also caused selective pulmonary venoconstriction. Vascular permeability measured by the capillary filtration coefficient and the isogravimetric Pc at 30 and 60 min after STA2 infusion did not change significantly from baseline in any lungs studied. Moreover, elevation of Pc by raising the venous reservoir of the intact lobes (n = 5) to the same level as the STA2 lungs caused a greater or similar weight gain compared with the STA2 lungs. Thus, we conclude that TxA2 constricts selectively the pulmonary vein resulting in an increase in Pc and lung weight gain without significant changes in vascular permeability in isolated blood-perfused dog lungs.

Tyrosine phosphorylation and translocation of the c-cbl protein after activation of tyrosine kinase signaling pathways

The c-cbl protooncogene product (c-Cbl) is a 120-kDa protein that has been shown to bind to the Src homology 3 domains of various proteins, suggesting its involvement in signal transduction pathways. We identified one of the most prominent tyrosine-phosphorylated proteins in Fc gamma receptor (Fc gamma R)-stimulated macrophages to be c-Cbl. Tyrosine phosphorylation of c-Cbl occurred within 20 s after stimulation and reached maximum levels within 3-5 min. c-Cbl was also tyrosine-phosphorylated in epidermal growth factor (EGF) receptor-overexpressing cells upon EGF stimulation, in macrophages in response to CSF-1 treatment, and in v-src transformed cells. Furthermore, we found that c-Cbl associated with these kinases in vivo. In vitro, c-Cbl bound to the Src homology 3 domains of Src, Fyn, and Lyn in both unstimulated and Fc gamma R-stimulated macrophages. Examination of cells by immunofluorescence revealed that c-Cbl is diffusely distributed in the cytoplasm in both unstimulated macrophages and EGF receptor-overexpressing cells and translocated to a more specific compartment of the cell, consistent with the trans-Golgi region, following Fc gamma R clustering and EGF stimulation, respectively. These results suggest that c-Cbl is involved in the signaling pathways utilized by different types of tyrosine kinases.

Comparative study of vasodilator effects of the potassium channel openers NIP-121 and levcromakalim in dogs and rats

The effects of potassium channel openers NIP-121 ((+)-7,8-dihydro-6,6-dimethyl-7-hydroxy-8-(2-oxo-piperidine-1-yl)-6H- pyrano[2,3-ss]benz-2,1,3-oxadiazole) and levcromakalim were examined in vitro and in vivo. In isolated canine vascular beds, NIP-121 (3 x 10(-9) to 10(-7) M) and levcromakalim (3 x 10(-8) to 10(-6) M) produced a concentration-dependent reduction in the vasoconstrictor responses to U46619. The effects were antagonized by glibenclamide, an ATP-sensitive potassium channel blocker. The maximal relaxation was more than 70% of the maximal vasodilation induced by papaverine (10(-4) M), except in the basilar artery. These compounds had very potent effects on the coronary and cranial mesenteric arteries and saphenous vein. In the coronary perfused rat heart, both compounds (10(-7) M) also increased coronary perfusion flow. The effects were also inhibited by glibenclamide (10(-6) M). In anesthetized dogs, NIP-121 (1 to 10 micrograms/kg (3.2 to 32 nmol/kg), i.v.) and levcromakalim (3 to 30 micrograms/kg (10.5 to 105 nmol/kg), i.v.) dose-dependently increased coronary and renal blood flow. NIP-121 and levcromakalim at higher doses produced the greatest increase in coronary blood flow among the blood vessels examined, in spite of the hypotensive effect. In conclusion, NIP-121 and levcromakalim were similarly selective vasodilators on the canine isolated coronary and cranial mesenteric arteries and saphenous vein, and they selectively increased coronary blood flow in vivo. With respect to increasing the coronary blood flow, NIP-121 had a fourfold greater potency than levcromakalim. This effect might be related to the glibenclamide-sensitive potassium channels.

Height reduction among prenatally exposed atomic-bomb survivors: a longitudinal study of growth

Using a random coefficient regression model, sex-specific longitudinal analyses of height were made on 801 (392 male and 409 female) atomic-bomb survivors exposed in utero to detect dose effects on standing height. The data set resulted from repeated measurements of standing height of adolescents (age 10-18 y). The dose effect, if any, was assumed to be linear. Gestational ages at the time of radiation exposure were divided into trimesters. Since an earlier longitudinal data analysis has demonstrated radiation effects on height, the emphasis in this paper is on the interaction between dose and gestational age at exposure and radiation effects on the age of occurrence of the adolescent growth spurt. For males, a cubic polynomial growth-curve model applied to the data was affected significantly by radiation. The dose by trimester interaction effect was not significant. The onset of adolescent growth spurt was estimated at about 13 y at 0 Gy. There was no effect of radiation on the adolescent growth spurt. For females, a quadratic polynomial growth-curve model was fitted to the data. The dose effect was significant, while the dose by trimester interaction was again not significant.

Liver with hypoechoic nodular pattern as a risk factor for hepatocellular carcinoma

BACKGROUND/AIMS

Ultrasonography should be used for screening of hepatocellular carcinoma, but there are few reports on the relationship between liver ultrasonographic findings and the development of hepatocellular carcinoma (HCC). Using prospective follow-up studies, we examined the role of liver with a hypoechoic nodular pattern as a high-risk factor in HCC.

METHODS

The study was performed by follow-up on 593 patients with chronic liver disease recorded at our hospital. The ultrasonographic pattern of the liver parenchyma was classified either as a small or large hypoechoic nodular pattern or as a nonnodular pattern. Patients were followed up from the time of initial ultrasonographic examination (1985-1987) until January 1, 1991.

RESULTS

During the follow-up period (average, 4.2 years, range, 0.3-6.0 years), 62 patients were found to have HCC (12%). Patients whose livers showed small or large hypoechoic nodular pattern had a significantly higher risk of HCC than did patients whose livers showed a nonnodular pattern (rate ratios were 14.0 and 20.0, respectively, adjusted for age, sex, hepatitis virus markers, ICG R15, alpha-fetoprotein concentration, and ultrasonographic pattern of the liver).

CONCLUSIONS

Liver showing a hypoechoic nodular pattern is a major risk factor in HCC.

Effect of lysyl hydroxylase inhibitor, minoxidil, on ultrastructure and behavior of cultured rabbit subconjunctival fibroblasts

BACKGROUND

Minoxidil is an inhibitor of lysyl hydroxylase, an enzyme involved in collagen production, and decreases collagen production in vitro. We investigated the in vitro effects of minoxidil on behavior such as proliferation and migration of rabbit subconjunctival fibroblasts (SCFs). The ultrastructural effect of the drug on SCFs was also examined.

METHODS

Proliferation of SCFs and closure of the defect produced in monolayer cultures in the presence or absence of minoxidil was studied. The ultrastructure of SCFs treated with minoxidil was also examined.

RESULTS

Minoxidil inhibited SCF proliferation and the closure of the defect produced in monolayer cell sheets. Ultrastructural observations revealed extensive areas of irregularly dilated endoplasmic reticulum in cells treated with minoxidil, indicating the accumulation of protein, probably underhydroxylated collagen precursors, in the cisternae of endoplasmic reticulum.

CONCLUSIONS

The results indicated that minoxidil attenuated cellular activities of SCFs such as proliferation and migration in vitro. The exact mechanism of the inhibitory effects of minoxidil on these cellular activities is unknown. The findings suggest that the drug might help to prevent bleb scarring after glaucoma filtering surgery.

Aromatase in bone cell: association with osteoporosis in postmenopausal women

To clarify the possible action of adrenal androgen on bone cell, the existence, characteristics and regulation of aromatase in human osteoblast-like osteosarcoma cells (HOS) and primary cultured osteoblast-like cells from normal human bones (HO) were examined in this study. Significant positive correlation between bone mineral density (BMD) and serum dehydroepiandrosterone sulfate (DHEA-S) was found in 120 postmenopausal women (51-99 years old) but no correlation was seen between BMD and serum estradiol (E2). In subset analysis, strongly positive correlation of serum DHEA-S and estrone (E1) with BMD was observed in postmenopausal women aged less than 69 years old. Administration of DHEA to ovariectomized rat significantly increased BMD and decreased relative osteoid volume in femur. These in vivo findings strongly suggested that serum adrenal androgen may be converted to estrogen in peripheral organ, especially, osteoblast and be important steroids to maintain BMD. [3H]DHEA was converted to [3H]androstenedione and [3H]androstenedione to [3H]estrone in primary cultured human osteoblast. Osteoblast-like cells showed aromatase activity, and an apparent Km and the Vmax were 4.74 +/- 0.78 nM (mean +/- SD, n = 3) and 0.83 +/- 0.79 fmol/mg protein/h for HOS, and 4.6 +/- 2.9 nM and 279 +/- 299 fmol/mg protein/h (mean +/- SD, n = 19) for HO, respectively. The aromatase activity was significantly increased by dexamethasone in a dose-dependent manner. Reverse transcription-polymerase chain reaction analysis revealed that dexamethasone increased the transcript of P450AROM gene. Osteoblast-specific promoters were also determined. Dexamethasone and 1 alpha,25-dihydroxyvitamin D3 synergistically enhanced aromatase activity and P450AROM mRNA expression. These results demonstrate that adrenal androgen, DHEA, is converted to E1 in osteoblast by P450AROM which is positively regulated by glucocorticoid and 1 alpha,25-dihydroxyvitamin D3 and important to maintain BMD in the 6 to 7th decade, after menopause.

Alteration of gamma-ray-induced chromosome aberration by 0.5 M NaCl in Chinese hamster cells

Hypertonic treatment (0.5 M NaCl in phosphate-buffered saline, pH 7.2) at 37 degrees C for 20 min slightly delayed the mitotic frequency for non-irradiated cells in G1 and G2 phases. The mitotic frequency for irradiated cells in G2 was delayed by hypertonic treatment, and that in G1 was slightly delayed by hypertonic treatment. Hypertonic treatment in non-irradiated cells did not induce any chromosomal or chromatid aberrations in either G1 or G2. Chromosomal aberrations caused by gamma-irradiation were slightly enhanced by hypertonic treatment, and chromatid aberrations were markedly enhanced by hypertonic treatment. The enhancement ratio of gamma-irradiation-induced chromatid breaks and exchanges was 1.4 and 3.0, respectively. This cell cycle dependency of chromosome aberrations induced by postirradiation hypertonic treatment was the same as that of cell survival. These findings suggested that hypertonic treatment modifies the rejoining of DNA strand breaks in G2, but slightly modifies that in G1.

Dissection of GLUT4 recycling pathway into exocytosis and endocytosis in rat adipocytes. Evidence that GTP-binding proteins are involved in both processes

The effects of guanine nucleotides on either exocytosis or endocytosis of GLUT4 were examined in electrically permeabilized rat adipocytes by using Dk-(62-85), a major histocompatibility complex class I-derived peptide. Reversal of glucose transport activity that had been stimulated with insulin was completely blocked by Dk-(62-85). Likewise, endocytosis of the trypsin-cleaved 35-kDa fragment of GLUT4 was almost completely inhibited by the peptide. Insulin-stimulated glucose transport activity was enhanced about 50% by Dk-(62-85), whereas the basal transport activity was stimulated only slightly. Although guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) augmented glucose transport to the same extent as insulin in the absence of the peptide, glucose transport stimulated by GTP gamma S was only 60% of the insulin effect in the presence of the peptide; the effect of insulin was markedly enhanced by Dk-(62-85), whereas GTP gamma S-induced glucose transport was not affected, suggesting that GTP gamma S has an effect similar to that of the peptide. In fact, endocytosis of the 35-kDa fragment of GLUT4 was markedly inhibited by GTP gamma S. Additionally, GLUT4 endocytosis was accelerated by GTP but was inhibited by guanosine 5'-O-(2-thiodiphosphate). These results indicate that GTP gamma S induces translocation of GLUT4 by both stimulating exocytosis and inhibiting endocytosis. With respect to the dependence on GTP hydrolysis, distinct types of GTP-binding proteins are involved in exocytosis and endocytosis of GLUT4.

Characterization of a 14q+ marker chromosome in philadelphia chromosome positive acute lymphoblastic leukemia by DNA analysis and fluorescence in situ hybridization

We report a case of precursor-B acute lymphoblastic leukemia (ALL) with the Philadelphia chromosome (Ph) and a 14q+ chromosome whose additional material was a part of the long arm of der(9)t(9;22). A minor population carrying the standard Ph translocation without the 14q+ was also observed at the first presentation. The translocation of the BCR gene from chromosome 22 to the subtelomeric region of the 14q+ was confirmed by fluorescence in situ hybridization (FISH) using a yeast artificial chromosome (YAC) clone containing the BCR gene. The breakpoint of chromosome 14 could not be determined exactly but probably was at 14q24 or 14q32 by conventional chromosome analysis. Nevertheless, FISH using a YAC clone containing the human immunoglobulin heavy chain (IgH) gene locus, Southern blot, and pulsed-field gel electrophoresis (PFGE) analyses with IgJH probe, and loss of heterozygosity analysis at the alpha 1-antitrypsin (AT) gene locus showed lack of involvement of the IgH gene in the 14q+ and more centromeric breakage than the alpha 1-AT locus at 14q32.1. Thus, the formation of the 14q+ seemed to be a secondary genetic event after the Ph translocation and presumably played a minor role in the pathogenesis of B-cell malignancy in this case.

Conversion of amylase-secreting rat pancreatic AR42J cells to neuronlike cells by activin A

When AR42J cells, an amylase-secreting pancreatic exocrine cell line, were treated with activin A, cells extended neuritelike processes, and, concomitantly, amylase-containing vesicles disappeared. Immunofluorescence and immunoelectron microscopy revealed that these processes had neurite-specific cytoskeletal architectures: neurofilaments and microtubule bundles with cross-bridges of microtubule-associated protein 2. In addition to such morphological changes, activin-treated cells exhibited a marked increase in cytoplasmic free calcium concentration in response to depolarizing concentration of potassium. Moreover, activin-treated AR42J cells expressed mRNA for alpha 1 subunit of the neuroendocrine/beta cell-type voltage-dependent calcium channel. In naive AR42J cells, a sulfonylurea compound, tolbutamide, did not affect free calcium concentration, while it induced a marked elevation of free calcium in activin-treated cells. Single channel recording of the membrane patch revealed the existence of ATP-sensitive potassium channel in activin-treated cells. These results indicate that activin A converts amylase-secreting AR42J cells to neuronlike cells. Given that pancreatic endocrine cells possess neuronlike properties and express ATP-sensitive potassium channel as well as neuroendocrine/beta cell-type voltage-dependent calcium channel, activin treatment of AR42J cells may provide an in vitro model system to study the conversion of pancreatic exocrine cells to endocrine cells in islets.

Simultaneous DNA typing of human platelet antigens 2, 3 and 4 by an allele-specific PCR method

We developed an allele-specific polymerase chain reaction (ASPCR) method using originally designed primers to determine the genotype of the human platelet antigens (HPAs) 2, 3 and 4 in parallel. The results were compared with those obtained by PCR restriction fragment length polymorphism and the mixed passive hemagglutination test. Seventy-three individuals were tested and the ASPCR results were in good agreement with those determined by the other two methods. This method enables the genotyping of HPA-2, -3 and -4 in parallel without the use of platelets, platelet-specific alloantibodies or restriction enzymes.

[Antibacterial activities of cefmenoxime against recent fresh clinical isolates from patients in sinusitis]

In order to evaluate antimicrobial activity of cefmenoxime (CMX), minimum inhibitory concentrations (MICs) of CMX and control drugs were determined against clinical isolates from patients of sinusitis that were obtained in our laboratory from October of 1993 to March of 1994. The results are summarized as follows; 1. CMX showed strong antimicrobial activities against Streptococcus pneumoniae, Haemophilus influenzae and Moraxella subgenus Branhamella catarrhalis that were 3 major aerobic bacteria from sinusitis. Antimicrobial activities of CMX against benzylpenicillin (PCG)-insensitive S. pneumoniae (PISP) and PCG-resistant S. pneumoniae (PRSP) were stronger than those of ampicillin (ABPC), and these strong activities suggested that CMX might have strong antimicrobial activities against beta-lactamase producing H. influenzae and M. (B.) catarrhalis. 2. Antimicrobial activities of CMX against microaerophiles, Streptococcus constellatus, Streptococcus intermedius and Gemella morbillorum and against Peptostreptococcus spp., from chronic sinusitis and odontogenic maxillary sinusitis, were stronger than those of most of the control drugs. 3. The MIC90's of CMX against isolates from patients of sinusitis were < or = 0.025-0.39 micrograms/ml. These values were lower than transitional concentrations in mucous membrane of maxillary sinus obtained when "1% CMX nasal solution" was used with nebulizer. It appears likely that sufficient concentrations exceeding MICs against main organisms would be obtained by nebulizer treatment using CMX nasal solution.

Suppression of infectious virus spread to the liver by foscarnet following lethal infection of acyclovir-resistant herpes simplex virus type 2 in mice

Patients with the acquired immune deficiency syndrome (AIDS) occasionally develop hepatitis, pneumonia or esophagitis due to herpes simplex virus type 2 (HSV-2) infection. HSV hepatitis is a rare but serious complication in liver transplantation. Acyclovir-resistant HSV strains may emerge in immunocompromised patients. Following intraperitoneal inoculation, HSV-2 induces necrotizing hepatitis in mice. We studied the virus spread and mortality following intraperitoneal inoculation of HSV-2 RK (an acyclovir-resistant recombinant virus with altered thymidine kinase activity) as compared to its parent virus 8620K. Neither the 50% lethal dose (LD50) nor the average survival time was significantly different between the two strains. Parenteral acyclovir treatment was found to be effective against 8620K but not RK infection. Parenteral foscarnet treatment was effective against both RK and 8620K, and also inhibited the spread of either virus to the liver, spinal cord and brain. Peroral foscarnet administration was found to prevent the virus growth in the liver.

Protein synthesis and degradation in flight muscles of adult crickets (Gryllus bimaculatus)

The development and degeneration of the flight muscles in adult crickets, Gryllus bimaculatus, were studied (1) by determination of the total protein content, (2) by SDS one-dimensional polyacrylamide gel electrophoresis (SDS&shy;PAGE) of muscle protein and (3) by in vitro culturing of the muscle. The total protein content of the dorso-longitudinal muscle (DLM) and metathoracic dorso-ventral muscle (DVM) increased during the early days of adult life in both sexes. This high protein content was maintained for at least a further 10 days in some individuals, while in others it declined to a low level. Mesothoracic DVMs in males also showed an increase in protein content after adult emergence but did not undergo histolysis, whereas those in females showed no significant temporal change in protein content. Removal of hind wings or artificial de-alation was found to be useful in inducing degeneration of DLMs and metathoracic DVMs. This treatment also stimulated ovarian development in females. An analysis by SDS&shy;PAGE provided no evidence for new protein synthesis prior to or during flight muscle degeneration. A high rate of [3H]- or [35S]methionine incorporation was observed in DLMs taken from newly emerged adults, but, in intact crickets, the rate declined rapidly during the first 3 days of adult life, a pattern consistent with that obtained from the measurement of total protein content. Compared with DLMs removed from intact crickets, DLMs taken from de-alated crickets showed reduced rates of protein synthesis during in vitro culturing. This, together with the onset of protein degradation, appears to cause the rapid decrease in total protein content of the muscle in de-alated crickets.

Prophylaxis with intraoperative chemohyperthermia against peritoneal recurrence of serosal invasion-positive gastric cancer

Continuous hyperthermic peritoneal perfusion (CHPP) with a solution which contains 30 mg mitomycin C and 300 mg cisplatin has been introduced as a prophylactic treatment for peritoneal recurrence after curative resection of 79 advanced gastric cancers. The control group consisted of 81 patients with advanced gastric cancer who underwent curative surgery during the same period. CHPP was performed for 60 minutes by perfusing MMC- and CDDP-containing saline solutions warmed at 43.5 degrees C by a special CHPP device. In patients with pathologically confirmed serosal invasion-positive tumors, the survival rate of the CHPP group was significantly higher than that of the control group. A survival advantage for stage IV patients was also obtained by CHPP. However, there was no survival advantage between the CHPP group and the control group with serosal invasion-negative tumors. Adverse effects were observed in four patients who underwent CHPP: One developed severe bone marrow suppression, and transient hyperazotemia was observed in the other three. There was no difference in the incidence of mortality and morbidity between the two groups. These results indicate that CHPP is a safe, readily available prophylactic therapy for peritoneal recurrence after gastric cancer surgery.

Effect of cyclic AMP on urokinase-type plasminogen activator receptor and fibrinolytic factors in a human osteoblast-like cell line

We investigated the effect of cyclic AMP (cAMP) on the pericellular fibrinolytic system in NY cells. Dibutyryl cAMP (dbcAMP) or forskolin increased the level of urokinase-type plasminogen activator (u-PA) mRNA and enhanced the secretion of u-PA antigen into the conditioned medium. These agents also increased u-PA antigen on the cell surface. PA inhibitor-1 (PAI-1) antigen was inhibited by dbcAMP or forskolin. Butyrate had no effect on the production and secretion of u-PA and PAI-1. A binding assay of 125I-DFP-u-PA to NY cells revealed a single class of binding sites with a Kd of 3.85 nM and Bmax of 0.89.10(5) binding sites/cell. The Bmax was increased by dbcAMP (1 mM or 10 mM), forskolin (2 microM or 20 microM) of 1.0-, 1.4-, 1.2- and 1.8-fold, respectively. However, the Kd value was not changed. Furthermore, the level of mRNA for the u-PA receptor (u-PAR) was increased by these agents 1.2-, 1.7-, 1.8- and 2.5-fold, respectively. However, butyrate did not alter either the Bmax or the u-PAR mRNA level. These results indicated that the pericellular fibrinolytic activity induced by u-PA/u-PAR is modulated by cAMP in osteoblast-like cells.

Regulation and localization of midkine in rat ovary

In a previous experiment, it was shown that midkine (MK) was quite abundant in the follicular fluid; the concentration of MK in bovine follicular fluid was estimated to be 125 micrograms/l. To investigate the regulation of MK production in the ovary, we examined the effect of pregnant mare's serum gonadotropin (PMSG) and PMSG-hCG treatment on the expression of MK in rat ovary. The mRNA of midkine (MK) was increased by PMSG injection and decreased by PMSG and hCG injection; the profile of change of mRNA of MK was similar to that of FSH receptor. Using in situ hybridization, we observed that the MK mRNA localized to granulosa cells. These results suggest that the granulosa cells produce MK under the control of gonadotropin.