Roles of myosin light-chain kinase in platelet shape change and aggregation

We examined the roles of myosin light-chain kinase in platelet responses to ADP using wortmannin, which almost completely inhibited myosin light-chain kinase at 3-6 microM. This concentration of wortmannin did not affect ADP-induced changes in the shape of the platelets, but it markedly inhibited aggregation in platelet-rich plasma and washed platelets. ML-9, another inhibitor of myosin light chain kinase, elicited similar effects on the platelet responses to wortmannin. Electron microscopic studies showed that there was no wortmannin effect on the ADP-induced spheration of discoid platelets, pseudopod formation, or granule centralization. Wortmannin at concentrations which prevented myosin light-chain kinase also inhibited platelet aggregation induced by ADP in the presence of U46619, an analogue of thromboxane A2, which is a prerequisite for ADP-induced irreversible aggregation. Although wortmannin partially inhibited protein kinase C, the protein kinase C inhibitor Ro-31-7549 (5 microM) prevented neither ADP- or ADP/U46619-induced changes in the shape of the platelets nor aggregation. These results suggest that myosin light-chain kinase activation is a prerequisite for ADP-induced platelet aggregation, but not for changes in their shape.

Intestinal permeability of ophthalmic beta-blockers for predicting ocular permeability

The purpose of this study was to investigate the intestinal permeability of ophthalmic beta-blockers and evaluate the utility of intestinal membrane for predicting the ocular permeability. The penetrations of beta-blockers were measured across the isolated jejunum and colon of the albino rabbit using a two-chamber glass diffusion cell. beta-Blockers tested include atenolol, carteolol, tilisolol, timolol, and befunolol. Colonic membrane showed lower permeability of hydrophilic drugs than jejunal membrane. Scraping the entire cell monolayer of jejunum increased the drug permeability. There was a significant correlation between colonic permeability coefficients and lipophilicities of beta-blockers. The permeability coefficients through jejunum and scraped jejunum were not susceptible to drug lipophilicities. Jejunum, scraped jejunum, and colon showed permeability coefficients almost equal to those of sclera, conjunctiva, and cornea, respectively. There was a significant correlation between permeability coefficients through colon and cornea. These results indicate that the steady-state permeability of ophthalmic beta-blockers through ocular membranes may be predicted by measuring the permeability through certain intestinal membranes. However, the analyses of intestinal permeability using Fick's equation showed the functional difference of intestinal permeability from ocular permeability of ophthalmic beta-blockers.

A multivariate analysis of assessment of myometrial invasion of endometrial carcinoma by magnetic resonance imaging

Thirty-nine cases of endometrial carcinoma were analyzed by magnetic resonance imaging (0.15 or 1.5 tesla (T) MRI) prior to surgery to evaluate the depth of myometrial invasion of endometrial carcinoma. Several diagnostic parameters of MRI were set: maximum area of high-intensity area (HIA) in sagittal (HIASI) and transverse (HIATI) images of the uterus, minimum width of remaining myometrium (MWRM), and ratio of minimum to maximum width of normal myometrial thickness (RMMT). In analysis of correlation between myometrial invasion and MRI parameters, the correlation coefficient values of HIASI, HIATI, and MWRM were higher than those of other parameters at 0.71, 0.69, and -0.74, respectively. When cases were classified into three groups according to tumor invasion (tumor limited to endometrium, invasion to less than 50% of the myometrium, invasion to greater than 50% of the myometrium), MWRM was the most useful as a single parameter. Since HIASI and MWRM were independent parameters of myometrial invasion, they were selected for multivariate analysis. An equation to calculate the predicted depth of myometrial invasion was derived using both HIASI and MWRM by the multiple linear regression model. The equation could estimate the degree of myometrial invasion from the parameters of 1.5 T MRI. The values obtained from the equation are more useful for prediction of myometrial invasion of endometrial carcinoma than single parameters in both 0.15- and 1.5-T MRI.

Production and characterization of a novel tissue-type plasminogen activator derivative in Escherichia coli

We have created a novel thrombolytic agent by the combination of mutation with partial deletion of tissue-type plasminogen activator (t-PA). We constructed Escherichia coli expression vectors for (i) native t-PA (nt-PA) and its derivatives; (ii) K1K2P, consisting of kringle 1 (K1), kringle 2 (K2), and protease (P) domains; (iii) K2P, consisting of K2 and P domains; (iv) D-nt-PA; (v) D-K1K2P; and (vi) D-K2P. The latter three are point mutants of nt-PA, K1K2P, and K2P, respectively, in which Arg275 (number corresponds to that of nt-PA) has been mutated to Asp. The production of nt-PA and its derivatives was remarkably improved by (i) removal of the 3' noncoding region of nt-PA cDNA from expression vectors and (ii) expression in mutant E. coli derived from E. coli HB101, which is insensitive to heat-shock inductions. The proteins produced were precipitated as insoluble aggregates in the cells and were renatured to active forms by extraction with 8 M urea followed by dialysis against a redox buffer containing GSH and GSSG. The renaturation yield depended on the pH of the buffer and the number of disulfide bonds of the proteins (nt-PA << K1K2P < K2P). The mutation of Arg275 (the plasmin cleavage site) caused an increase in the catalytic enhancement by fibrin and a decrease of the interaction with plasminogen activator inhibitors.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic heterogeneity of dominantly inherited olivopontocerebellar atrophy (OPCA) in the Japanese: linkage study of two pedigrees and evidence for the disease locus on chromosome 12q (SCA2)

We did a linkage study of 2 multigenerational pedigrees with dominant olivopontocerebellar atrophy (OPCA) other than SCA1, with chromosome 12q microsatellites. Multipoint linkage analysis led to the conclusion that the disease locus locates within the 6.2 cM interval between IGF1 and D12S84/D12S105. This result coincides with that of Cuban ataxia pedigrees designated as SCA2. Our study provides genetic evidence that dominant OPCA in the Japanese consists of at least two genetically different disorders; SCA1 and SCA2.

Allelotype of endometrial carcinoma

An allelotype analysis of endometrial carcinoma was undertaken to identify chromosomal loci that are relevant to this tumor type. A total of 70 highly polymorphic microsatellite markers, distributed among all nonacrocentric chromosome arms, were examined for evidence of loss of heterozygosity or allelic imbalance in DNA samples from matched normal and tumor tissues. An average of 21 informative tumor cases were obtained for each marker. Allelic deletions or imbalance were observed on 31 of 41 chromosome arms with no marker showing an allelic loss ratio of greater than 33%. Those chromosome arms most frequently involved were 3p, 8p, 9p, 14q, 16q and 18q. There was a strong correlation between loss of heterozygosity on chromosome 14q and death from disease. These data indicate that the molecular genetic character of endometrial carcinoma is complex and that a relatively large number of different chromosomal loci are likely to play a role in the etiology and progression of this tumor type.

Synthesis of a novel bis(2,4'-bithiazole) derivative as a Co(II)-activated DNA cleaving agent

A novel DNA cleaving agent, N,N'-bis(2-[4-(3-aminopropylcarbamoyl)-2,4'-bithiazol-2'-yl] ethyl) ethylenediamine (1), was synthesized. At 25 microM concentration, a significant cleaving activity of 1 for plasmid DNA was observed only in the presence of Co(II). Scavengers of active oxygen species could not inhibit the DNA cleavage by 1.

Markedly increased amounts of messenger RNAs for vascular endothelial growth factor and placenta growth factor in renal cell carcinoma associated with angiogenesis

The presence of mRNAs for vascular endothelial growth factor (VEGF) and a VEGF-related protein, placenta growth factor (PIGF) was examined in 29 cases of renal cell carcinoma tissues and adjacent normal kidney tissues and in 4 human renal cell carcinoma cell lines. Northern blot analysis showed that 26 of 27 hypervascular renal cell carcinoma tissues (96%) exhibited a markedly elevated level (3-13 fold) of VEGF mRNA compared to the adjacent normal kidney tissues. Even tumors of small size, whenever they were hypervascular, overexpressed VEGF mRNA. We also demonstrated that mRNA for PIGF was expressed in 21 of 23 hypervascular renal cell carcinoma tissues (91%) but was not detected in the adjacent normal kidney tissues. Two hypovascular carcinoma tissues neither overexpressed VEGF mRNA nor had PIGF mRNA. VEGF mRNA was detected in four human renal cell carcinoma cell lines, while PIGF mRNA was not. There was no difference in the level of basic fibroblast growth factor mRNA between tumor tissues and normal kidney tissue, although our previous study demonstrated elevated basic fibroblast growth factor protein in the serum of renal cell carcinoma patients (K. Fujimoto et al., Biochem. Biophys. Res. Commun., 180: 386-392, 1991). Taken together, these results suggest that VEGF, PIGF, and basic fibroblast growth factor are cooperatively working to increase the angiogenesis in renal cell carcinoma in vivo.

Altered synaptophysin-immunoreactive pattern in human olivary hypertrophy

We examined the inferior olivary nucleus from four cases of olivary hypertrophy and six control cases immunohistochemically with an anti-synaptophysin (SYP) antibody. Our study revealed the altered SYP-immunoreactive pattern in the hypertrophied olives, consisting of an increased number of SYP-immunoreactive dots on neuronal cell bodies in spite of its decreased immunoreactivity in the neuropil. Because SYP is a marker protein for presynaptic vesicles, presynaptic terminals in the inferior olivary nucleus seem to change their distribution during the course of olivary hypertrophy.

Physical association of JAK1 and JAK2 tyrosine kinases with the interleukin 2 receptor beta and gamma chains

The functional interleukin 2 (IL-2) receptors contain the beta and gamma chains which are necessary for the transduction of cell growth signals. Monoclonal antibodies specific for the beta chain and gamma chain coimmunoprecipitated JAK1 and 114-kDa JAK2 tyrosine kinases, respectively. Tyrosine phosphorylation of JAK1 and JAK2 was induced upon IL-2 stimulation, and IL-2 activated the JAK2 kinase. These results demonstrate that the JAK1 and JAK2 tyrosine kinases are physically associated with the beta chain and gamma chain, respectively, and suggest that regulation of the kinases may be linked to IL-2-induced signal transduction.

High incidence of silent aspiration in elderly patients with community-acquired pneumonia

Pneumonia is a major cause of death in the elderly. To investigate the role of silent aspiration in community-acquired pneumonia, we examined the occurrence of silent aspiration during sleep in 14 elderly patients with acute episode of pneumonia and 10 age-matched control subjects by a new technique using indium111 chloride. Scanning of the thorax demonstrated that 71% of patients aspirated, whereas aspiration was observed in only 10% of control subjects. The percentage of positive scans was significantly higher in patients with acute episode of pneumonia than in control subjects (p < 0.02). The results may indicate an important role of silent aspiration in the development of community-acquired pneumonia in the elderly.

Observer disagreement in histological classification of ovarian tumors in Japan

Histological slides of 789 cases of ovarian tumor registered by the Japanese Gynecologic Oncology Group, sponsored by the Ministry of Health and Welfare, Japan, were reviewed by three certified pathologists in order to evaluate the observer disagreement among the pathologists and the reproducibility of the histological classification. In 53.0% of the cases, all observers agreed upon the diagnosis. At least two of them agreed in 88.4% of the cases. The observer disagreement was highest for low potential malignancy (borderline malignancy) tumors (44.4%), including serous, mucinous, and endometrioid tumors. The results of the study clearly indicate the necessity of establishing a slide review system in order to obtain reliable data for comparative research. Moreover, the histological criteria, especially of tumors of borderline malignancy, should be more clearly defined to obtain high reproducibility of ovarian tumor diagnosis.

Recombinant human tumor necrosis factor causes regression in patients with advanced malignancies

Fifteen patients with advanced solid tumors of various types were treated by the intratumoral administration of recombinant human tumor necrosis factor (rH-TNF). The treatment appeared to benefit the 4 cases of superficial tumors: there were 1 complete response, 1 partial response and 2 minor responses. In all 11 patients with deep-seated tumors, including 6 cases of pancreatic cancer, 4 of liver cell cancer and 1 of metastatic liver tumor, no tumor regression was observed, but progression stopped in all these tumors. Seven of the 11 with deep-seated tumors showed a decrease in tumor markers and/or the development of tumor necrosis. Fever, hypotension and fatigue were the main clinical side effects. No significant changes were found in hematologic, renal or liver parameters. These results suggest that administration of rH-TNF to the tumor site has the potential for controlling local tumor growth.

Gliclazide directly suppresses arginine-induced glucagon secretion

To clarify whether the effect of sulfonylurea on glucagon secretion is directly on the pancreatic A cell, we examined changes produced by gliclazide in glucagon (IRG), insulin (IRI) and somatostatin (IRS) release from the isolated perfused rat pancreas. Under 5 mM glucose infusion, IRI and IRS were increased by gliclazide in a dose-dependent manner, but IRG was unchanged. When 20 mM arginine was infused to stimulate glucagon secretion, both IRI and IRG increased markedly in a biphasic fashion and IRS increased slightly. The administration of gliclazide at the time of second phase response of IRG, IRI and IRS increased further and IRG decreased at every dose used. Insulin administration to the control and streptozotocin-treated rat pancreas did not change arginine-induced IRG secretion. Gliclazide-induced glucagon suppression was also observed in streptozotocin-diabetic rat pancreas. The amount of administered somatostatin required for inhibiting glucagon secretion was higher than the maximal level obtained from endogenous secretion of somatostatin after gliclazide. Neither cysteamine treatment alone (somatostatin-depleted) nor combined with streptozotocin-treatment (combined depletion of somatostatin and insulin) changed gliclazide-induced glucagon suppression. Thus, it is concluded that suppression of glucagon is induced by sulfonylurea itself.

Catecholamine-induced cAMP response in streptozotocin-induced diabetic rat liver

The effect of prolonged diabetic state on catecholamine-induced adenosine 3',5'-monophosphate (cAMP) response in the rat liver was examined using isolated liver perfusion. Epinephrine- or isoproterenol-induced cAMP production was enhanced (10-fold of the control) in the liver from extremely emaciated (intraperitoneal adipose tissue was absent completely) diabetic rats 4 weeks after streptozotocin-injection kept without insulin, but not from adipose tissue-present diabetic rats. Glucagon-induced cAMP production was decreased in the diabetic rat liver 4 weeks after streptozotocin regardless of the presence or absence of adipose tissue. Secretin-induced cAMP production was also decreased in the adipose tissue-absent diabetic rat liver. Plasma levels of glucose or insulin were not different between adipose tissue-present and -absent diabetic rats. Liver dysfunction (elevated AST and ALT levels) was observed 1 week after streptozotocin-injection, and worsened at 4 weeks. Forskolin-induced production of cAMP, and oxymetazoline (an alpha 2-adrenergic agonist)-induced suppression of it were not different among the control, newly diabetic (1 week after streptozotocin-injection), and the adipose tissue-absent diabetic rat liver.

IN CONCLUSION

1) enhanced beta-adrenergic, and decreased glucagon- or secretin-induced cAMP production seems to be caused by different mechanisms; 2) the prolonged severe diabetic state losing adipose tissue may cause a considerable change in metabolism and the characteristics of hepatocyte, and lead to enhanced beta-adrenergic cAMP production.

Preferential alternative splicing in cancer generates a K-sam messenger RNA with higher transforming activity

K-sam, also designated fibroblast growth factor receptor 2/BEK, was originally cloned from a stomach cancer cell line KATO-III. The gene is amplified and overexpressed preferentially in poorly differentiated types of stomach cancers. The major K-sam transcript in KATO-III cells encodes a receptor protein with a truncated carboxyl terminus and with a high-affinity binding site for keratinocyte growth factor. This truncated type is produced by an alternative splicing mechanism, and in normal tissues, the truncated type is far less prevalent than the untruncated form. The variant K-sam complementary DNA lacks tyrosine 769, which is a putative phospholipase C gamma 1 association site, and showed a higher transforming activity to NIH3T3 cells than the untruncated form, which is identical with the keratinocyte growth factor receptor.

Role of Src homology 3 domains in assembly and activation of the phagocyte NADPH oxidase

The phagocyte NADPH oxidase, dormant in resting cells, is activated during phagocytosis to produce superoxide, a precursor of microbicidal oxidants. The activated oxidase is a complex of membrane-integrated cytochrome b558, composed of 91-kDa (gp91phox) and 22-kDa (p22phox) subunits, and two cytosolic factors (p47phox and p67phox), each containing two Src homology 3 (SH3) domains. Here we show that the region of the tandem SH3 domains of p47phox (p47-SH3) expressed as a glutathione S-transferase fusion protein inhibits the superoxide production in a cell-free system, indicating involvement of the domains in the activation. Furthermore, we find that arachidonic acid and sodium dodecyl sulfate, activators of the oxidase in vitro, cause exposure of p47-SH3, which has probably been masked by the C-terminal region of this protein in a resting state. The unmasking of p47-SH3 appears to play a crucial role in the assembly of the oxidase components, because p47-SH3 binds to both p22phox and p67phox but fails to interact with a mutant p22phox carrying a Pro-156-->Gln substitution in a proline-rich region, which has been found in a patient with chronic granulomatous disease. Based on the observations, we propose a signal-transducing mechanism whereby normally inaccessible SH3 domains become exposed upon activation to interact with their target proteins.

Glucocorticoids suppressed production and gene expression of interleukin-5 by peripheral blood mononuclear cells in atopic patients and normal subjects

BACKGROUND

Interleukin-5 (IL-5) is known to play a major role in regulating eosinophil function in atopic diseases, including bronchial asthma. Glucocorticoids are most effective agents for treating these diseases. However, their mechanism remains unclear. We examined the effects of glucocorticoids on the production and gene expression of IL-5 in atopic patients and normal subjects.

METHODS

Human peripheral blood mononuclear cells (PBMCs) in five atopic and four normal subjects were cultured with phytohemagglutinin and phorbol 12-myristate 13-acetate (PMA) in the presence of dexamethasone. IL-5 secreted by PBMCs was assayed by ELISA. Gene expression of IL-5 by PBMCs was assessed semiquantitatively by sequential reverse transcription-polymerase chain reaction, and Southern blot analysis.

RESULTS

Phytohemagglutinin/PMA-stimulated PBMCs from all atopic patients and three normal subjects secreted detectable amounts of IL-5, which were suppressed by dexamethasone in a dose-dependent manner, with 85.8% suppression at 10(-6) mol/L. Gene expression of IL-5 was detected by reverse-transcription polymerase chain reaction in PBMCs from all subjects, even when not stimulated; was increased by stimulation; and was suppressed by dexamethasone. The concentration of dexamethasone resulting in 50% inhibition in IL-5 gene expression did not differ between atopic patients and normal subjects.

CONCLUSION

These findings indicate that dexamethasone suppressed IL-5 production in atopic human PBMCs through an inhibitory action on the gene expression. These results suggest that the suppression of IL-5 production through the suppression of IL-5 gene expression is one of the most important mechanisms by which glucocorticoids inhibit eosinophil functions in the treatment of atopic diseases, including bronchial asthma.

Holographic motion picture by Eu(3+):Y(2)SiO(5)

Real-time recording of a moving object was made with persistent spectral hole burning of a cryogenic Eu(3+):Y(2)SiO(5) crystal. In a basic holographic configuration the ultrastable laser frequency was continuously scanned within the (7)F(0)-(5)D(0) absorption line (typically 200 MHz in 20 s) while the object was in motion, thus permitting the storage and reconstruction of the moving image. The success of this motion picture is attributable to (1) the kilohertz-wide hole width, (2) the quasi-persistent hole lifetime, and (3) the high hole-burning quantum efficiency of this material.

[Studies on clinical usefulness of new tumor markers of ovarian cancer, CA54/61 and CA602--III. Measurement of serum samples from patients with various benign or malignant diseases]

Serum samples from patients with benign or malignant diseases were measured for the newly developed tumor markers CA54/61 and CA602 with the respective EIA kits for assessment of their utility as tumor markers. A total of 5236 patients were entered into the study, consisting of ovarian cancer patients, those with other cancers, pregnant women, and healthy volunteers. The CA54/61-positive rate with a cut-off value of 12 U/ml was 61.2% for ovarian cancers (50.4% with a cut-off value of 20 U/ml). A positive rate of 75.0% (64.4%) was achieved for mucinous cystadenocarcinoma, which was high, compared with that for CA125. On the other hand, the false-positive rate was 12.2%(5.9%) for benign ovarian tumors, and as low as 18.5%(8.7%) for endometriosis. The CA602-positive rate with a cut-off value of 63 U/ml was as high as 76.0% for ovarian cancers (69.8% with a cut-off value of 90 U/ml). On the other hand, the false-positive rate was relatively high at 21.9% (12.6%) for benign ovarian tumors, and 56.7% (40.0%) for endometriosis. These positive rates were therefore similar to those for CA 125. The levels of both CA54/61 and CA602 antigens well reflected the postoperative prognosis. These results suggest the utility of CA54/61 and CA 602 as tumor markers of ovarian cancers.

Effects of long-term enalapril treatment on persistent micro-albuminuria in well-controlled hypertensive and normotensive NIDDM patients

OBJECTIVE

To determine whether long-term treatment with an angiotensin-converting enzyme (ACE) inhibitor has a beneficial effect on the urinary microalbumin excretion and renal function in non-insulin-dependent diabetes mellitus (NIDDM) patients, enalapril (5 mg/day) was administered for 48 months.

RESEARCH DESIGN AND METHODS

-Fifty-two patients with NIDDM who had persistent microalbuminuria in the range of 20-300 mg/24 h, serum creatinine < 106.1 microM (1.2 mg/dl), supine systolic blood pressure (BP) < 150 mmHg, supine diastolic BP < 90 mmHg, and HbA1c < 10% were divided into four groups. Twenty-six patients with normotension were divided at random into two groups; one group received enalapril (5 mg/day) (NE group), the other did not receive enalapril (NC group). In the same way, 26 other patients who were already well-controlled with nifedipine (30 mg/day) over a long-term period (4-6 years) were divided at random into two groups; one received enalapril (5 mg/day) (HE group), the other did not receive enalapril (HC group).

RESULTS

After 48 months, urinary albumin excretion (UAE) was markedly reduced in group NE from 102.4 x/divided by 1.3 to 55.5 x/divided by 1.3 mg/24 h (P < 0.005), whereas no significant change occurred in group NC. In the well-controlled hypertensive groups, a significant reduction in UAE occurred in group HE (P < 0.05), whereas no significant change occurred in group HC. No changes in creatinine clearance, BP, or blood glucose control were seen during the study.

CONCLUSIONS

Treatment with enalapril for 48 months may have a beneficial effect on the decline of microalbumin excretion in NIDDM patients.

Acute intermittent porphyria caused by a single base insertion of C in exon 15 of the porphobilinogen deaminase gene that results in a frame shift and premature stopping of translation

A single base insertion of C in exon 15 of the porphobilinogen deaminase (PBG-D) gene was observed in a patient with acute intermittent porphyria (AIP) by polymerase chain reaction (PCR)-direct sequencing analysis. The insertion locates between positions -22 and -21 from the translation termination codon TAA, causes a frame shift, and results in a stop codon located 4 codons downstream from the insertion (premature stopping of translation). The mutation generates an MspI recognition site, which can be used, in turn, to detect the mutant allele. Analysis of the cDNA fragments amplified by PCR revealed the existence of the abnormal PBG-D mRNA from the mutant allele in the patient.