Accelerated cell-cycling of hematopoietic progenitor cells by growth factors

Recent advances in molecular biology have led to the identification of hematopoietic growth factors that support and influence the proliferation of hematopoietic progenitor cells in vitro and in vivo. Although these factors have been extensively studied, little is known of their role in the regulation of cell-cycling of hematopoietic progenitors, especially in the early stage of hematopoiesis. In the present study, we examined the effects of early acting growth factors on proliferative kinetics of hematopoietic progenitors by monitoring the number of cells in individual developing colonies, using an in vitro clonal assay. Interleukin-11 (IL-11) or steel factor (SF), alone or in combination, shortened the time for the size of IL-3-dependent colonies to double. Consecutive replating experiments provided evidence for direct action of growth factors on the growth rate of hematopoietic progenitor cells. Shortening of the time for the total cell number in the colonies to double was due to a reduction in time for each single cell within the respective colonies to become two daughter cells, and there was no alteration in the incidence of cells with a proliferative capacity. Cell-cycle analysis demonstrated that IL-11 has the potential to induce a shortened time for cell-cycle of hematopoietic progenitor cells without affecting distribution of each fraction of the cell-cycle, whereas SF has the potential to reduce cell-cycle time mainly by decreasing the time required for hematopoietic progenitor cells to go through the G1 phase. These results suggest that growth factors may modulate cell-cycling of hematopoietic progenitor cells.

The mechanism responsible for hypertension in a patient with Guillain-Barré syndrome

We report a case of hypertension associated with Guillain-Barré syndrome. In this case, the circadian variation of blood pressure was interrupted. Examination of neurohumoral factors revealed a hyperactive sympathetic nervous system and an increase in plasma renin activity. Clonidine, which acts centrally to inhibit sympathetic outflow, did not suppress serum norepinephrine or epinephrine. These observations suggest that autonomous hyperactivity of the efferent pathway of the sympathetic nervous system may cause the sustained hypertension throughout the day in this case.

Pressor effect of recombinant human erythropoietin: results of ambulatory blood pressure monitoring and home blood pressure measurements

We investigated whether treatment of anemic hemodialysis patients with a low dose of recombinant human erythropoietin (erythropoietin) for a short period would increase their blood pressure. Ambulatory blood pressure monitoring and home blood pressure measurements were used to detect minute increase in blood pressure. Thirty-two patients with a hematocrit of 25% or less received erythropoietin at the dose of 4500 IU/week, by the intravenous route for 8 weeks. Erythropoietin increased the hematocrit from 20.9 +/- 2.1 to 26.2 +/- 2.1%. Erythropoietin elevated mean ambulatory blood pressure by 5 mmHg or more in two-thirds of patients (n = 20; pressor group), while it elevated home mean blood pressure by 5 mmHg or more in one-third of patients (n = 11). An increase in clinic mean blood pressure by more than 5 mmHg was observed only in one-fourth of patients (n = 7). Circadian variation of blood pressure (nocturnal fall and diurnal rise) had been attenuated in the patients of the pressor group before erythropoietin treatment and erythropoietin decreased the nocturnal fall of blood pressure further more. Erythropoietin elevated nocturnal blood pressure more than diurnal blood pressure. Therefore, the increase in blood pressure induced by erythropoietin was detected more reliably by ambulatory blood pressure monitoring. There was no relation between the change in hemoglobin concentration and the increase in ambulatory blood pressure induced by erythropoietin. Erythropoietin tended to decrease cardiac output and plasma volume while it increased total peripheral resistance. It also decreased plasma norepinephrine and vasopressin levels but did not affect other humoral factors. Although the pressor effect of erythropoietin treatment for 8 weeks at the dose of 4500 IU/week was not evident on clinic blood pressure measurements, any increase in blood pressure determined by ambulatory blood pressure should be treated carefully to reduce the risk of a cardiovascular complication in patients receiving hemodialysis.

Cyclic AMP enhances acetylcholine (ACh)-induced ion fluxes and catecholamine release by inhibiting Na+, K(+)-ATPase and participates in the responses to ACh in cultured bovine adrenal medullary chromaffin cells

The effects of cyclic AMP (cAMP) on intracellular Na+ concentration ([Na+]i), membrane depolarization and intracellular Ca2+ concentration ([Ca2+]i) and the involvement of cAMP in acetylcholine (ACh)-induced such cellular events and catecholamine (CA) release were studied in cultured bovine adrenal medullary chromaffin cells. 8-Bromo-cyclic AMP (8Br-cAMP) and forskolin caused a rise in [Na+]i, membrane depolarization and a rise in [Ca2+]i and potentiated these responses and CA release to ACh. The effects of 8Br-cAMP or forskolin on ACh-induced changes of but not on basal level of [Na+]i, membrane potential and [Ca2+]i were blocked by tetrodotoxin (TTX, 1 microM). In Na+ deprivated medium, forskolin failed to produce an increase in basal [Ca2+]i level and to potentiate ACh-induced rise. The similar results as in 8Br-cAMP and forskolin were obtained using ouabain, and 8Br-cAMP or foskolin produced no further effects in the presence of ouabain. Inhibitors of cAMP-dependent protein kinase not only blocked the effects of 8Br-cAMP and forskolin on membrane depolarization, [Ca2+]i rise and CA release, but also reduced these responses to ACh. From the similarity between the effects of cAMP and those of ouabain on the cellular events and the counteraction of the effects of cAMP by ouabain, it may be suggested that cAMP produces its effects on ion fluxes and CA release probably via an inhibition of Na+, K(+)-ATPase in intact chromaffin and cAMP may participate in the responses to ACh.

Embryo culture in explanted oviducts in mice and cattle

Developmental block of early embryos is due to the lack of some components in the culture medium and/or caused by inappropriate environmental conditions for embryonic development. It was shown in our experiments that the development of mouse and bovine embryos under the influence of oviducts in vitro can provide us with a model to analyze the oviductal factors that promote embryonic development. In the first experiment, it was shown that mouse zygotes developed to the blastocyst stage when a coculture system with ampulla was applied, and the duration of embryo coculture significantly affected the further development of embryos. In the second experiment, it was shown that the proportion of blastocysts of cleaved ova obtained after coculture with mouse ampulla was significantly higher than that obtained after coculture with a granulosa cell monolayer or culture without cells.

Decreased plasma tissue factor pathway inhibitor levels in patients with thrombotic thrombocytopenic purpura

We measured plasma levels of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in patients with thrombotic thrombocytopenic purpura (TTP) and disseminated intravascular coagulation (DIC) to examine the relationship between TFPI and vascular endothelial cell injury. TF antigen was detected in the plasma of healthy volunteers, and the levels were significantly increased in the patients with DIC, but decreased slightly in those with TTP. Plasma TFPI levels were significantly decreased in patients with TTP compared with those in healthy volunteers. The concentration of plasma thrombomodulin (TM) antigen was significantly higher in those with TTP than in normal volunteers. One month after treatment, TTP patients showed a significant decrease in plasma TM levels, and a significant increase in plasma TFPI levels, but plasma levels of TF antigen were not significantly increased. As plasma TFPI/TF ratio was significantly increased after treatment, the hypercoagulable state was therefore improved after treatment. There was no significant difference in plasma TF and TFPI levels between those who achieved complete remission (CR) and those who died. However, plasma TM levels were significantly higher in those who died than in those who achieved CR. Plasma TFPI levels might reflect injury of vascular endothelial cells as do plasma TM levels, and decreased plasma TFPI/TF ratio and vascular endothelial cell injuries might play causative roles in TTP.

Compliance with long-term dietary salt restriction in hypertensive outpatients

Eighty hypertensive outpatients were recruited for a dietary salt restriction program to examine long-term compliance. Twenty-four-hour urine samples were collected repeatedly (7.9 +/- 2.6 times, mean +/- s.d.) during a follow-up period of 6.4 +/- 1.7 years. After initial urine collection, nutritional education was carried out by dietitians to reduce dietary salt intake to 8 g/day or less. After every urine collection, the subjects were given advice by doctors on salt restriction, if necessary. The mean 24-hour urinary salt excretion (U-NaCl) and the mean urinary salt/creatinine ratio (U-NaCl/U-Cr) varied considerably both among and within individuals. U-NaCl/U-Cr, but not U-NaCl, in females was significantly higher than that in males, and in middle-aged subjects than in young subjects. U-NaCl and U-NaCl/U-Cr tended to decrease in the summer. In spite of the repeated educational effort, neither U-NaCl nor U-NaCl/U-Cr was different in the first control samples from that in the last samples. When 57 subjects were divided into three groups according to the urinary salt excretion level, U-NaCl was consistently higher during a follow-up period in the high-salt excretion group than in the mid-salt excretion group, while U-NaCl in the low-salt excretion group was initially lower than, but finally similar to, that in the mid-salt excretion group. These results suggest that: (1) multiple 24-hour urine samplings are required to assess urinary salt excretion in individuals; (2) the influence of age and sex should be taken into account in interpreting U-NaCl/U-Cr; and (3) it seems difficult to achieve long-term dietary salt restriction as a non-pharmacologic treatment of hypertension in an outpatient clinic.

A high-salt diet alters circadian blood pressure rhythm in Dahl rats

To determine whether salt loading and salt sensitivity are related to the circadian variation in blood pressure (BP), we studied the circadian rhythm of BP in Dahl rats. Thirteen Dahl salt-sensitive (Dahl-S) and 14 salt-resistant (Dahl-R) rats were fed a high- or low-salt diet after weaning. Mean arterial pressure (MAP) and heart rate (HR) were measured every 4 sec throughout 24 hr in freely moving rats, and the data obtained were analyzed quantitatively by the cosinor method. MAP mesor was significantly elevated in Dahl-S rats on a high-salt diet (SH), as compared with those on a low-salt diet (SL), but there was no difference in the MAP mesor between Dahl-R rats on a high-salt diet (RH) and those on a low-salt diet (RL). MAP amplitude was significantly greater and HR amplitude was smaller in SH rats than in SL rats; the amplitudes of MAP and HR in RH rats were similar to those in RL rats. MAP acrophase was significantly delayed in SH and RH rats as compared with SL and RL rats, respectively; the time delay in the MAP acrophase was not accompanied by a synchronized delay in HR acrophase. The time delay in MAP acrophase was greater in SH rats than in RH rats. These results indicate that salt loading influences the amplitude and acrophase of BP, and that the effect of salt loading on circadian BP rhythm is modulated by salt sensitivity.

Pharmacological evidence for regulation of Na(+)-Ca++ exchange by Ca++/calmodulin-dependent protein kinase in isolated bovine adrenal medullary cells

The mechanism of the regulation of Ca++ influx via Na(+)-Ca++ exchange in response to Na+ deprivation was studied in bovine adrenal medullary cells. Protein kinase inhibitors staurosporine and (8R*,9S*,11S*)-(-)-9-hydroxy-9-methoxycarbonyl-8-methyl2,3,9,10-te trahydro-8, 11-epoxy-1H,8H, 11H-2,7b, 11a-triazadibenzo[a,g]cycloocta[c,d,e]trinden- 1-one depressed Na+ deprivation-induced 45Ca++ uptake and catecholamine secretion in a concentration-dependent manner. However, 1 mM dibutyryl cyclic AMP and 1 microM forskolin, an activator of adenylate cyclase, had little effect on Na+ deprivation-induced 45Ca++ uptake and catecholamine secretion. Dibutyryl cyclic GMP (1 mM) and muscarine (30 microM), which increased intracellular cyclic GMP level via stimulation of muscarinic receptors, had also little effect on the responses. Although the phorbol esters 12-O-tetradecanoyl-phorbol-13-acetate and phorbol 12,13-dibutyrate, activators of protein kinase C, enhanced Na+ deprivation-induced catecholamine secretion, these compounds failed to affect Na+ deprivation-induced 45Ca++ uptake. On the other hand, a variety of calmodulin antagonists such as calmidazolium, trifluoperazine, pimozide and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide inhibited Na+ deprivation-induced 45Ca++ uptake and catecholamine secretion in a concentration-dependent manner. Furthermore, 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpipera zin e, which is known as an inhibitor of Ca++/calmodulin-dependent protein kinase II, also reduced Na+ deprivation-induced 45Ca++ uptake and catecholamine secretion. Chelation of intracellular Ca++ with Quin-2 acetoxymethyl ester resulted in a decrease in Na+ deprivation-induced 45Ca++ uptake. However, these compounds that inhibited the Na+ deprivation-induced responses in the cells did not cause solely nonspecific and direct inhibition on Na(+)-Ca++ exchanger. These pharmacological observations suggest that Ca++/calmodulin-dependent protein kinase is involved in the regulation of Na(+)-Ca++ exchange in bovine adrenal medullary cells.

Characterization of a novel cofilin isoform that is predominantly expressed in mammalian skeletal muscle

Cofilin is an actin-modulating protein of 20 kDa, which is widely distributed throughout muscle and non-muscle cells. By means of immunoblotting combined with two-dimensional gel electrophoresis, we found that two cofilin variants, muscle type (M-type) and non-muscle type (NM-type), exist in mammals, while a single isoform exists in chickens. During in vitro myogenesis of mouse C2 cells, expression of the M-type cofilin was upregulated. To better understand the nature of the M-type cofilin, we cloned cDNAs encoding M-type cofilin from the cDNA library of C2 myotubes and determined the entire sequence. The deduced peptide sequence contained a nuclear localization signal and a putative actin-binding sequence as reported in NM-type cofilin. The sequence showed 81% identity in the amino acid residues with the mouse NM-type cofilin sequence and, interestingly, higher homology (96% identity) with that of chicken cofilin. The mRNA encoding M-type cofilin, though it contains two variants that differ in the size of their 3'-non-coding sequences, was detected predominantly in heart, skeletal muscle, C2 myotubes, and testis by Northern blotting, while the mRNA for NM-type cofilin was seen in a variety of non-muscle tissues. The presence of the muscle type isoform of cofilin strongly suggests that cofilin is deeply involved in the regulation of actin function not only in non-muscle cells but also in muscle cells.

Possible involvement of nitric oxide in acetylcholine-induced increase of intracellular Ca2+ concentration and catecholamine release in bovine adrenal chromaffin cells

The role of nitric oxide (NO) in neurotransmitter release was studied using bovine adrenal medullary chromaffin cells. L-Arginine and sodium nitroprusside (SNP) slightly increased the intracellular free calcium concentration ([Ca2+]i), and the effects of the agents were dependent on the presence of the extracellular Ca2+ ([Ca2+]o), but were not blocked by verapamil (30 microM) or diltiazem (30 microM). SNP enhanced the acetylcholine (ACh)-induced rise in [Ca2+]i in the presence but not in the absence of [Ca2+]o. The effects of L-arginine but not those of SNP were inhibited by N omega-nitro-L-arginine (L-NNA). L-NNA significantly reduced the ACh-induced rise in [Ca2+]i and catecholamine (CA) release, and the reduction was restored by L-arginine but not by D-arginine. These results suggest a possible involvement of NO in ACh-induced [Ca2+]i rise and CA release in bovine adrenal chromaffin cells.

Developmental changes in and hormonal modulation of epidermal growth factor concentration in the rat submandibular gland

Developmental changes in the hormonal effects on the concentration of epidermal growth factor (EGF) in the rat submandibular gland were investigated. The level of EGF in the gland gradually increased with age from 4 up to 8 weeks of age; thereafter it increased markedly, reaching a plateau level at 12 weeks of age in both male and female rats. A significant sex difference in EGF levels was observed between 8 and 14 weeks, the level in the males being approximately twice as high as that in the females at 12 and 14 weeks of age. Castration of male rats decreased EGF to about the same level as that of control females. Treatment of castrated rats with testosterone propionate (TP) restored EGF to the levels in control male rats. Ovariectomy and/or administration of oestradiol-17 beta to ovariectomized rats had no apparent effect on EGF concentration. These findings indicate that the sex difference in EGF concentration can be attributed to the level of endogenous androgens. In addition, hypophysectomy of male rats caused a remarkable decrease in submandibular gland EGF to about 7% of the normal level. This reduction was significantly, although not completely, restored by the administration of TP, triiodothyronine (T3) or GH. Moreover, giving TP with T3 or with GH or both together had additive effects on the increase in EGF levels in hypophysectomized rats. These results provide evidence that EGF in the submandibular gland is regulated multihormonally by at least TP, T3 and GH.

Accuracy and performance of the Terumo ES-H51, a new portable blood pressure monitor

A high performance portable automatic sphygmomanometer, the Terumo ES-H51 (104 g, 58 x 22 x 92 mm), was newly developed for clinical use as a substitute for auscultation using a mercury sphygmomanometer. This device usually displays blood pressure (BP) values obtained by the Korotkoff sound method (K-method). However, when the device judges that BP values obtained by the K-method are inaccurate or unreliable, it substitutes automatically BP values obtained by the cuffoscillometric method (O-method). The accuracy and reliability of the device was tested by comparing it to the auscultation with the standard mercury sphygmomanometer. The mean difference between BP values obtained by the standard method and those obtained by the K-method were -0.7 +/- 2.9 mm Hg systole (mean +/- SD) and -0.3 +/- 2.6 mm Hg diastole, whereas the difference between the former and those obtained by the O-method were 0.3 +/- 5.7 mm Hg systole and 0.3 +/- 4.3 mm Hg diastole (n = 170). The agreement between the BP values obtained according to each of the two methods using the device and the standard method was within 5 mm Hg for 72% to 93% of both systolic and diastolic readings. Therefore, BP values measured by the ES-H51 are accurate. The ES-H51 is sufficiently small and light to be carried easily anywhere. The objective and reproducible BP information obtained by the present device would be useful in clinical practice.

Cyclic AMP-induced depolarization measured by bis-oxonol fluorescence in bovine adrenal medullary chromaffin cells

Effects of cyclic AMP on membrane potentials were examined by measuring the changes of bis-oxonol fluorescence in bovine adrenal medullary chromaffin cells. 8-Bromo cyclic AMP (8Br-cAMP) or forskolin caused a gradual and long lasting increase of the fluorescence intensity. The effects of 8br-cAMP was blocked by cyclic AMP-dependent protein kinase inhibitor, adenosine-3', 5'-cyclic monophosphothioate, Rp-diastereomer (Rp-cAMPS) and there was no further increase in the fluorescence by 8br-cAMP in the cells depolarized with 56 mM KC1 or gramicidin D. Ouabain or the removal of extracellular K+ ([K+]0 free) which block Na+, K+-ATPase also increased the fluorescence. The effect of 8br-cAMP on the fluorescence was counteracted by ouabain or [K+]0 free and was blocked in the absence of extracellular Na+ but not by tetrodotoxin or the removal of Ca2+ from the medium. These results may suggest that cyclic AMP causes the membrane depolarization by accumulating Na+ through the inhibition of Na+, K+-ATPase in adrenal chromaffin cells.

Pressor effect of recombinant human erythropoietin: results of home blood pressure measurements in hemodialysis patients

We investigated whether the treatment of anemic hemodialysis patients with a low dose of recombinant human erythropoietin (rHEpo) for a short period would increase the blood pressure (BP). Home BP measurements were used to detect minute increases in BP. Fifty-one anemic patients on maintenance hemodialysis with a hematocrit of 25% or less received rHEpo at the dose of 4500 IU/week by the intravenous route for 8 weeks. Overall, rHEpo did not increase the BP whether measured at home or in the clinic (causal BP). Hemoglobin concentration increased significantly from 7.1 +/- 0.7 to 8.8 +/- 0.7 g/dl. Patients were classified into two groups according to the change in mean (M) home BP induced by rHEpo: a pressor group (delta MBP > or = 5 mmHg, n = 17) and a non-pressor group (delta MBP < 5 mmHg, n = 34). The hemoglobin concentration rose significantly in both groups, but there was no change in casual BP. Home blood pressure measurements showed a gradual and continuous rise in BP in the pressor group, but not in the non-pressor group. Patients administered antihypertensive medications before rHEpo treatment accounted for 88% of the former and 50% of the latter groups. Two patients with malignant nephrosclerosis were included in the pressor group. The findings indicate that rHEpo, even given at a low dose for a short period, elevates the BP, as determined by home BP measurement, but not by casual measurements obtained in the clinic.

Ambulatory blood pressure of adults in Ohasama, Japan

We performed a cross-sectional study in a small town in northern Japan to evaluate the distribution, reference values, and daily variation in ambulatory blood pressure. A total of 705 subjects (229 men aged 61.3 +/- 13.4 years [mean +/- SD] and 476 women aged 57.5 +/- 13.3 years; 41.1% of the regional adult population, n = 1716), including those treated with antihypertensive drugs (n = 231, 66.5 +/- 9.5 years) as well as untreated subjects (n = 474, 55.0 +/- 13.5 years), participated in the study. Both ambulatory and screening blood pressures were measured in 659 subjects. Ambulatory blood pressure was measured with an automatic device (Colin ABPM-630). The 24-hour ambulatory blood pressure in the total population was 121.7 +/- 13.0/71.1 +/- 7.6 mm Hg (95th percentile value [95%] = 146/85 mm Hg). The corresponding value in the untreated subjects was 119.4 +/- 12.5/70.1 +/- 7.4 mm Hg (95% = 144/83 mm Hg). The 24-hour average ambulatory blood pressure was 118.0 +/- 11.1/69.4 +/- 6.8 mm Hg (95% = 139/81 mm Hg) in subjects identified as normotensive by their screening blood pressure (n = 448, 57.2 +/- 13.1 years) and 133.6 +/- 14.2/78.9 +/- 8.8 mm Hg in those identified as hypertensive by their screening blood pressure (n = 73, 63.1 +/- 10.6 years). Based on the mean+SD of the 24-hour ambulatory blood pressure in the normotensive subjects by their screening blood pressure (129/76 mm Hg), the 24-hour ambulatory blood pressures in 25 (34.2%) of these 73 hypertensive subjects by screening blood pressure were below this level. Nine (2%) of 448 normotensive subjects by screening blood pressure were above the mean+2 SDs (140/83 mm Hg) of the 24-hour ambulatory blood pressure in the normotensive group by screening blood pressure. Ambulatory and screening blood pressures increased with age. The age-dependent increase in ambulatory blood pressure was less apparent in men. The 24-hour average pulse rate decreased with age. The daily variation in ambulatory blood pressure (standard deviation) increased with age, whereas that of pulse rate decreased with age. Increases in blood pressure variation were observed in nighttime and daytime blood pressure values. The differences between day versus night ambulatory blood pressures decreased with age in men but not in women.(ABSTRACT TRUNCATED AT 400 WORDS)

Characteristics of a community-based distribution of home blood pressure in Ohasama in northern Japan

OBJECTIVE

To evaluate the distribution, reference values and day-to-day variation of blood pressure of untreated subjects measured at home.

DESIGN

Cross-sectional study of a cohort.

SETTING

General community in northern Japan.

SUBJECTS

Blood pressure was measured in 871 subjects (mean +/- SD age 46.0 +/- 19.5 years, range 7-98, constituting 38.7% of the local population of Uchikawama region, Ohasama) who were not receiving antihypertensive medication.

METHODS

Subjects measured their own blood pressure at home at least three times (mean +/- SD 19.7 +/- 8.4) each morning using a semi-automatic oscillometric blood pressure measuring device. Screening blood pressure was measured once.

MAIN OUTCOME MEASURES

Distribution of home blood pressure in the study population as a whole and with respect to age and sex, and the distribution of day-to-day variation of home blood pressure were determined.

RESULTS

Mean home blood pressure was 117.3 +/- 13.4/69.3 +/- 9.7 mmHg (95% confidence interval 116.4-118.2/68.7-70.0). The 95th centile value was 143/85 mmHg, mean+SD 131/79 mmHg and mean + 2SD 144/89 mmHg. Mean screening blood pressure was 126.2 +/- 18.9/72.1 +/- 11.7 mmHg (95th centile 159/92 mmHg). Age- and sex-specific 95th centile values as well as mean +/- SD were obtained. Mean+SD, mean + 2SD and the 95th centile values obtained as reference upper limits of home blood pressure from subjects identified as normotensive by screening blood pressure (n = 707) were 125/77, 137/86 and 134/83 mmHg, respectively. Home blood pressure increased gradually with increasing age in both men and women, although blood pressure was significantly higher in men until 50 years of age. Day-to-day variation of home systolic blood pressure also increased with age.

CONCLUSION

Since the distribution of home blood pressure values was affected by age and sex, age- and sex-matched reference values for home blood pressure should be established. Home blood pressure values in elderly subjects should be evaluated carefully, since these exhibit greater day-to-day variation.

Increased expression of cofilin in dystrophic chicken and mouse skeletal muscles

A monoclonal antibody (McAb) specific for actin depolymerizing factor (ADF) was prepared. With this and previously prepared anti-cofilin McAb (MAB-22) and other antibodies, the expression of cofilin and ADF in the muscles of dystrophic (NH-413) chicken and dystrophic (C57BL/6J dy/dy) mice was compared with that in normal control animals by immunoblotting and immunocytochemical methods. Since cofilin expression is down-regulated during normal postnatal development of skeletal muscles [Abe et al. (1989) J. Biochem. 106, 696-702], cofilin was detected in the breast (pectoralis) muscle of normal adult chicken and the leg (femoris and tibialis anterior) muscles of normal mice only at a low level. ADF was not detectable in adult skeletal muscles. However, a significant increase of cofilin amount, but not of ADF amount, was observed in these muscles of the dystrophic animals, when the symptom of muscular dystrophy became evident. In order to localize cofilin in individual muscle fibers, serial cryosections of the dystrophic chicken muscle were examined with anti-cofilin antibody (MAB-22). The antibody stained cells of different size in the dystrophic muscle, indicating that cofilin expression was induced in the regenerating muscle cells as well as in the pre-existing myofibers. We suggest that cofilin is involved in disassembly or reorganization of actin in the dystrophic muscle.

Immunoblotting of contractile and cytoskeletal proteins of canine basilar artery in vasospasm

Vasospasm was produced in the canine basilar arteries by a two-hemorrhage method, and voltage- and receptor-dependent contractions of the normal canine basilar arteries were induced by local applications of potassium chloride (KCI) and serotonin, respectively, after transclival exposure. Actin, myosin, desmin, filamin, talin, vinculin, and alpha-actinin in the basilar artery were studied by immunoblotting. The immunoblots showed a decrease or loss in immunoreactivity of some native proteins and generation of protein fragments, smaller in size than native proteins, in spastic, KCI, and serotonin groups, indicating a proteolytic degradation. In the spastic group on Day 2, actin, desmin, and filamin were usually degraded slightly; myosin moderately; and talin and alpha-actinin substantially. Vinculin and metavinculin remained intact. In the spastic group on Day 7, actin and desmin were usually decomposed slightly; myosin, filamin, and vinculin substantially; and talin, metavinculin, and alpha-actinin markedly. In the KCI and serotonin groups, slight degradation was usually observed in filamin, often in alpha-actinin, and occasionally in actin, whereas desmin, vinculin, and metavinculin were not degraded. In addition, myosin was usually degraded moderately in the KCI group and slightly in the serotonin group, and talin was generally decomposed slightly in the KCI group and moderately in the serotonin group. The degraded fragments, although variable in number and immunoreactivity, were similar in size in the three groups. We suggest that the intracellular devices responsible for contraction of the basilar arteries are degraded more severely in the spastic group than in the KCI or serotonin group, probably by similar proteolytic mechanism and progressively with the passage of time after subarachnoid hemorrhage in vasospasm.

Calpain-calpastatin system of canine basilar artery in vasospasm

Vasospasm was produced in the canine basilar artery by a two-hemorrhage method, while contraction was induced in the normal canine basilar artery by a local application of KCl or serotonin after transclival exposure. The control animals were injected with saline instead of fresh blood. The activation of mu-calpain, a Ca(++)-dependent neutral protease, in the basilar artery was studied by evaluating the conversion from its inactivated into its activated form on immunoblots. In addition, the activity of calpastatin, an intrinsic inhibitor of calpain, in the basilar artery was determined by assay. The majority of the mu-calpain was inactivated in the control group. In the spastic group, mu-calpain was generally activated markedly in the early stage of vasospasm and moderately thereafter. The contraction induced by KCl or serotonin application was classified into the early phasic and the later tonic stages; mu-calpain was usually activated in the phasic stage and inactivated in the tonic stage. Calpastatin activity was significantly decreased during vasospasm, whereas it was not significantly changed in KCl- or serotonin-induced contraction. The final activity of mu-calpain results from the balance of mu-calpain and calpastatin. This suggests that mu-calpain activity was enhanced continuously in the spastic group and transiently in the KCl or serotonin group, and that the continuous activation of mu-calpain during vasospasm probably induced more proteolytic changes compared to those in the KCl or serotonin group.

Increased levels of vascular endothelial cell markers in thrombotic thrombocytopenic purpura

We found that patients with thrombotic thrombocytopenic purpura (TTP) have significantly elevated plasma thrombin antithrombin III complex (TAT) and FDP-D-dimer levels, while the plasmin-alpha 2 plasmin inhibitor complex (PIC) level was only slightly increased. The tissue-type plasminogen activator (t-PA) level was increased, but it was well correlated with the plasminogen activator inhibitor-I (PAI-I) level. These findings suggest that hypercoagulable and hypofibrinolytic states coexist in these patients, in contrast to patients with disseminated intravascular coagulation, who exhibit coexisting hypercoagulable and hyperfibrinolytic states. Levels of vascular endothelial cell markers, such as PAI-I, thrombomodulin (TM), and t-PA, were increased at the onset of TTP, but the level of von Willebrand factor (vWF) antigen was not increased. The outcome in TTP patients was correlated with plasma t-PA and TM levels but not with TAT or PIC. These results suggest that vascular endothelial cell markers, such as TM and t-PA, are released from injured or stimulated endothelial cells, reflecting the degree of vascular endothelial damage, and that the main factor in the pathogenesis of TTP is vascular endothelial cell injury.

cDNA nucleotide sequence and primary structure of mouse uterine peptidylarginine deiminase. Detection of a 3'-untranslated nucleotide sequence common to the mRNA of transiently expressed genes and rapid turnover of this enzyme's mRNA in the estrous cycle

Peptidylarginine deiminase is a protein-modulating enzyme which converts the arginine residues in proteins to citrulline residues. This study describes the complete primary structure of mouse peptidylarginine deiminase, which was deduced from nucleotide sequence analysis of cDNA clones plus proteochemical analysis of the purified enzyme. The composite cDNA sequence contained a 5' untranslated region of 7 bases, an open reading frame of 2019 bases that encoded 673 amino acids, a 3' untranslated region of 2662 bases, and part of a poly(A) tail. The N-terminal and C-terminal sequences of the enzyme matched the sequences deduced from nucleotide analysis. Furthermore, we determined that the N-terminal sequence was N alpha-acetyl-Met-Gln-, a sequence which has never previously been reported among N alpha-acetyl-Met proteins. The Arg 352 of the enzyme was converted to a citrulline residue and the potential Asn-linked glycosylation site (Asn542-Glu543-Ser544) had no carbohydrate moiety. Thus, mouse peptidylarginine deiminase consists of 673 amino acids with a molecular mass of 76,260. Mouse peptidylarginine deiminase mRNA has two AU-rich structures in the 3' untranslated region which exhibit a high degree of similarity to those in lymphokine, cytokine and proto-oncogene mRNA species. Since the rat enzyme (previously reported) does not possess these characteristic structures, we compared the levels of enzyme activity and mRNA in the mouse and rat uterus at four defined phases of the estrous cycle. The degradation of peptidylarginine deiminase and its mRNA proceeded significantly faster in the mouse than in the rat. We speculate that the unusual structure of the mouse enzyme and its mRNA be involved in this species-specific rapid degradation.