Probing the catalytic site of rabbit muscle glycogen phosphorylase using a series of specifically modified maltohexaose derivatives

Glycogen phosphorylase (GP) is an allosteric enzyme whose catalytic site comprises six subsites (SG₁, SG_-1, SG_-2, SG_-3, SG_-4, and SP) that are complementary to tandem five glucose residues and one inorganic phosphate molecule, respectively. In the catalysis of GP, the nonreducing-end glucose (Glc) of the maltooligosaccharide substrate binds to SG₁ and is then phosphorolyzed to yield glucose 1-phosphate. In this study, we probed the catalytic site of rabbit muscle GP using pyridylaminated-maltohexaose (Glcα1-4Glcα1-4Glcα1-4Glcα1-4Glcα1-4GlcPA, where GlcPA = 1-deoxy-1-[(2-pyridyl)amino]-D-glucitol]; abbreviated as PA-0) and a series of specifically modified PA-0 derivatives (Glc _m -AltNAc-Glc _n -GlcPA, where m + n = 4 and AltNAc is 3-acetoamido-3-deoxy-D-altrose). PA-0 served as an efficient substrate for GP, whereas the other PA-0 derivatives were not as good as the PA-0, indicating that substrate recognition by all the SG₁ -SG_-4 subsites was important for the catalysis of GP. By comparing the initial reaction rate toward the PA-0 derivatives (V _derivative) with that toward PA-0 (V _PA-0), we found that the value of V _derivative/V _PA-0 decreased significantly as the level of allosteric activation of GP increased. These results suggest that some conformational changes have taken place in the maltooligosaccharide-binding region of the GP catalytic site during allosteric regulation.

Homoeologous chromosomes of Xenopus laevis are highly conserved after whole-genome duplication

It has been suggested that whole-genome duplication (WGD) occurred twice during the evolutionary process of vertebrates around 450 and 500 million years ago, which contributed to an increase in the genomic and phenotypic complexities of vertebrates. However, little is still known about the evolutionary process of homoeologous chromosomes after WGD because many duplicate genes have been lost. Therefore, Xenopus laevis (2n=36) and Xenopus (Silurana) tropicalis (2n=20) are good animal models for studying the process of genomic and chromosomal reorganization after WGD because X. laevis is an allotetraploid species that resulted from WGD after the interspecific hybridization of diploid species closely related to X. tropicalis. We constructed a comparative cytogenetic map of X. laevis using 60 complimentary DNA clones that covered the entire chromosomal regions of 10 pairs of X. tropicalis chromosomes. We consequently identified all nine homoeologous chromosome groups of X. laevis. Hybridization signals on two pairs of X. laevis homoeologous chromosomes were detected for 50 of 60 (83%) genes, and the genetic linkage is highly conserved between X. tropicalis and X. laevis chromosomes except for one fusion and one inversion and also between X. laevis homoeologous chromosomes except for two inversions. These results indicate that the loss of duplicated genes and inter- and/or intrachromosomal rearrangements occurred much less frequently in this lineage, suggesting that these events were not essential for diploidization of the allotetraploid genome in X. laevis after WGD.

[Risk factors for falls and survival after falling in elderly people in a community]

OBJECTIVES

The purpose of this study was to assess the risk factors associated with falls and to examine the effects of falls on survival of elderly people in a community.

METHODS

A questionnaire survey was conducted in 16,462 urban elderly dwellers aged 65 years or more in City A in September 2001. A follow-up survey was carried out in September 2004. We analyzed the data of 8,285 subjects who answered both questionnaires and had not relocated by August 2007. Baseline assessments of health and functioning were carried out in 2001. Falls experienced during the 1-year period before September 2004 were recorded, and the deaths were recorded until August 2007. Statistical analysis was performed using a logistic regression model and Cox's proportional hazards analysis.

RESULTS

A total of 6,420 subjects (3,127 men and 3,293 women) who had provided complete answers about their falls were included in the analyses. Of these, 27.8% of women and 16.4% of men had experienced falls, while 6.2% of women and 2.1% of men had experienced falls that caused fractures. We found that the likelihood of fall, with or without fracture development, was greater in women than in men (P < 0.001). The rate of falls tended to increase with age in both women and men. Risk factors associated with falls, in addition to age and gender, were pain (odds ratio [OR], 1.75), lack of instrumental activities of daily living (IADL; OR, 1.45), poor self-rated health status (OR, 1.42), and presence of disease (OR, 1.35). Risk factors associated with falls that caused fracture were pain (OR, 1.85) and lack of IADL (OR, 1.61). Cox's proportional hazards analysis showed a significant increase in mortality in both men and women who had experienced falls than in those who had not (hazard ratio [HR], 1.94, 1.43).

CONCLUSION

Aging, pain and disease, lack of IADL, and poor self-rated health status were all significant risk factors for falls in elderly people, and a fall was related to subsequent mortality.

[Chronological evaluation of physical, psychological and social health of urban elderly dwellers over 6 years and assessment of causal inter-relationships]

OBJECTIVES

The purpose of this study is to make a chronological evaluation over 6 years of physical, psychological and social health of urban elderly dwellers.

METHODS

A questionnaire survey was conducted with all urban elderly dwellers of 65 years old or more in A City in September, 2001. Answers were obtained from 13,195 people (response rate of 80.2%) in the first survey. Then 3 year and 6 year follow-up surveys of 2,375 members were performed in September 2004 and 2007. Causal relationships were analyzed using a Structural Equation Model based on the Cross-Lagged Effects Variation Model.

RESULTS

According to this research, a chronological six year trend in ADL (Activities of Daily Living) was found for "physical factor" (" " means latent variable) as an observed variable, with a shifted from 91.0% to 82.9%. A trend for self-rated health with healthy as an observed variable of "psychological factor" was similarly apparent, shifting from 85.4% to 77.0%. "Social factor" conducted on the follow-up survey in 2007 was significantly affected by the "psychological factor" investigated in 2001 and "physical factor" in the follow-up survey in 2004, indirectly based on the Cross-Lagged Effects Variation Model. "Social factor" totals of 25% for men and 19% for women were explained by this model with high validity levels (NFI = 0.935, IFI = 0.950, RMSEA = 0.036).

CONCLUSION

It was suggested that social health was affected by psychological health directly and physical health indirectly during six years follow-up of urban elderly dwellers. Future research is needed to encompass other generations and also to improve the external validity of the results.

Role of the N- and C-terminal domains in binding of apolipoprotein E isoforms to heparan sulfate and dermatan sulfate: a surface plasmon resonance study

The ability of apolipoprotein E (apoE) to bind to cell-surface glycosaminoglycans (GAGs) is important for lipoprotein remnant catabolism. Using surface plasmon resonance, we previously showed that the binding of apoE to heparin is a two-step process; the initial binding involves fast electrostatic interaction, followed by a slower hydrophobic interaction. Here we examined the contributions of the N- and C-terminal domains to each step of the binding of apoE isoforms to heparan sulfate (HS) and dermatan sulfate (DS). ApoE3 bound to less sulfated HS and DS with a decreased favorable free energy of binding in the first step compared to heparin, indicating that the degree of sulfation has a major effect on the electrostatic interaction of GAGs with apoE. Mutation of a key Lys residue in the N-terminal heparin binding site of apoE significantly affected this electrostatic interaction. Progressive truncation of the C-terminal alpha-helical regions which favors the monomeric form of apoE3 greatly weakened the ability of apoE3 to bind to HS, with a much reduced favorable free energy of binding of the first step, suggesting that the C-terminal domain contributes to the GAG binding of apoE by the oligomerization effect. In agreement with this, dimerization of the apoE3 N-terminal fragment via disulfide linkage restored the electrostatic interaction of apoE with HS. Significantly, apoE4 exhibited much stronger binding to HS and DS than apoE2 or apoE3 in both lipid-free and lipidated states, perhaps resulting from enhanced electrostatic interaction through the N-terminal domain. This isoform difference in GAG binding of apoE may be physiologically significant such as in the retention of apoE-containing lipoproteins in the arterial wall.

Angiotensin converting enzyme inhibitors attenuated the expression of G-protein coupled receptor kinases in heart failure patients

BACKGROUND

There are few biological markers, which strictly show the severity of congestive heart failure (CHF).

METHODS AND RESULTS

Lymphocyte G-protein coupled receptor kinase (GRK) mRNA expression was measured by quantitative reverse transcription-polymerase chain reaction in 15 CHF patients: 5 patients classified as New York Heart Association class-II treated with angiotensin converting enzyme inhibitor (ACEI) (IIA), 5 patients in class-II without ACEI (IIC), and 5 patients in class-III treated with ACEI (IIIA). GRK mRNA level in IIIA was significantly higher than those in IIA (p<0.05). GRK mRNA level in IIA were significantly lower than those in IIC (p<0.05).

CONCLUSIONS

The expression level of lymphocyte GRK might show the severity of CHF, and ACEI treatment could reduce the level of GRK in CHF patients.

Negative correlation between bone mineral density and TSH receptor antibodies in male patients with untreated Graves' disease

INTRODUCTION

Although it has been established that hyperthyroidism leads to reduced bone mineral density (BMD), with accelerated bone turnover promoting bone resorption in female patients, there is a dearth of data for male patients with hyperthyroidism. This study evaluated BMD and bone metabolism in male patients with Graves' disease.

METHODS

The study included 56 Japanese male patients with newly diagnosed Graves' disease and 34 normal Japanese male control subjects of similar age and body mass index. We used dual energy x-ray absorptiometry to measure BMD at sites with different cortical/cancellous bone ratios (lumbar spine, femoral neck, and distal radius).

RESULTS

At the lumbar spine and the distal radius, BMD and T-scores were significantly lower for patients than for controls. At the femoral neck, on the other hand, the same values were relatively, but not significantly, lower in patients than in controls. However, Z-scores at all three sites were significantly lower for patients than for controls. The Z -score at the distal radius of patients was significantly lower than that at their lumbar spine and femoral neck. In addition, Z-score at the distal radius correlated negatively with age, free thyroxine, thyroid stimulating hormone receptor antibodies, thyroid stimulating antibody, and urinary N-terminal telopeptide of type I collagen normalized by creatinine.

CONCLUSIONS

These results indicate a high prevalence of cortical bone loss in male patients with Graves' disease, especially elderly patients. We conclude that BMD measurement is crucial in all Graves' disease patients regardless of their gender and that the radial BMD as well as BMD at the lumbar spine and femoral neck should be monitored to effectively prevent bone loss and subsequent fracture.

Chronic beta-adrenergic receptor stimulation enhances the expression of G-Protein coupled receptor kinases, GRK2 and GRK5, in both the heart and peripheral lymphocytes

BACKGROUND

Enhanced expression of G protein-coupled receptor kinase (GRK) has been reported in failing hearts and in the present study the stability of enhanced GRK mRNA expression, and the correlation between the expression level of GRK mRNA in peripheral lymphocytes and in the heart were both evaluated.

METHODS AND RESULTS

Isoproterenol was injected into rats for 2 weeks, and then GRK5 mRNA was assessed by quantitative reverse transcriptase-palymerase chain reaction. An enhanced expression of cardiac GRK5 mRNA was observed even after 4 weeks of recovery. The isoproterenol-induced increased expression of GRK2 and GRK5 mRNA was equally observed in the heart and lymphocytes, and there was a close correlation between the heart and lymphocytes in the level of expression of each GRK mRNA.

CONCLUSIONS

The GRK mRNA level is maintained at a high level for a long period without continuous beta-adrenergic receptor stimulation. The level in circulating lymphocytes could be used as a surrogate marker to estimate the level of cardiac GRK expression and, presumably, the beta-adrenergic receptor function of cardiomyocytes.

Decreased bone mineral density at the distal radius, but not at the lumbar spine or the femoral neck, in Japanese type 2 diabetic patients

The purpose of this study is to assess the association between type 2 diabetes and bone mineral density. This study included 145 Japanese patients (64 men and 81 women) with type 2 diabetes and 95 non-diabetic control subjects (41 men and 54 women) of similar age. We measured bone mineral density (BMD) at the sites with different cortical/cancellous bone ratio (lumbar spine, femoral neck, and distal radius) using dual-energy X-ray absorptiometry. BMD and Z score at the distal radius were significantly lower in type 2 diabetic patients than those in control subjects, and in type 2 diabetic patients, the Z score at the distal radius was lower than that at their own lumbar spine and femoral neck. In type 2 diabetic patients, negative correlation between BMD and the mean HbA1c during the previous 2 years was found significantly at the distal radius in both genders and at the femoral neck in women. These results indicate the selective cortical bone loss in type 2 diabetes and suggest the importance of also determining BMD at the radius and keeping good metabolic control to prevent bone loss in type 2 diabetic patients.

Alpha-melanocyte-stimulating hormone stimulates prolactin secretion through melanocortin-3 receptors expressed in mammotropes in the mouse pituitary

The intermediate lobe of rodent pituitaries is involved in the regulation of prolactin (PRL) secretion from the anterior lobe. In a previous study, we demonstrated the stimulatory effect of alpha-melanocyte-stimulating hormone (alpha-MSH) on PRL release and the expression of melanocortin-3 receptors (MC3-Rs) in cultured mouse pituitary cells. The aim of the present study was to clarify whether alpha-MSH directly stimulates PRL release through the MC3-Rs by determining the cell type of MC3-R-expressing cells in the mouse pituitary anterior lobe. Northern blot analysis revealed a 2.7-kb transcript for MC3-R mRNA in the anterior and neurointermediate lobes of pituitary glands of adult male and female mice. Dual cellular localization of MC3-R mRNA and PRL or growth hormone (GH) in the mouse pituitary glands was performed by in situ hybridization analysis of MC3-R mRNA followed by immunocytochemical detection of PRL or GH. MC3-R mRNA was detected in most mammotropes and some somatotropes. alpha-MSH increased PRL release and stimulated DNA replication in mammotropes, and these effects were blocked by SHU9119, an antagonist of MC3-R and MC4-R. These results indicate that alpha-MSH stimulates PRL release and proliferation of mammotropes through MC3-Rs, and suggest that alpha-MSH from intermediate lobes can regulate mammotrope functions in the mouse pituitary.

Suppression of head formation by Xmsx-1 through the inhibition of intracellular nodal signaling

It is well established that in Xenopus, bone morphogenetic protein (BMP) ventralizes the early embryo through the activation of several target genes encoding homeobox proteins, some of which are known to be necessary and sufficient for ventralization. Here, we used an inhibitory form of Xmsx-1, one of BMP’s targets, to examine its role in head formation. Interestingly, ventral overexpression of a dominant Xmsx-1 inhibitor induced an ectopic head with eyes and a cement gland in the ventral side of the embryo, suggesting that Xmsx-1 is normally required to suppress head formation in the ventral side. Supporting this observation, we also found that wild-type Xmsx-1 suppresses head formation through the inhibition of nodal signaling, which is known to induce head organizer genes such as cerberus, Xhex and Xdkk-1. We propose that negative regulation of the BMP/Xmsx-1 signal is involved not only in neural induction but also in head induction and formation. We further suggest that the inhibition of nodal signaling by Xmsx-1 may occur intracellularly, through interaction with Smads, at the level of the transcriptional complex, which activates the activin responsive element.

Vascular smooth muscle cell proliferation is effectively suppressed by the non-specific growth factor inhibitor suramin

The purpose of this study was to investigate the effects of the non-specific growth factor inhibitor suramin on smooth muscle cell proliferation in vitro and in vivo. Cultured vascular smooth muscle cells (VSMC) were stimulated by platelet-derived growth factor (PDGF) and cellular DNA synthesis assessed by [3H]-thymidine uptake. Suramin dose-dependently inhibited DNA synthesis in VSMC, and 100 microM of suramin completely suppressed the PDGF-AB-induced cellular DNA synthesis. Rabbit carotid arteries were injured by the balloon catheter, and then suramin locally delivered using a porous balloon catheter over ten minutes. Three weeks after the vascular injury, the extent of intimal thickening was compared between the suramin-treated and control rabbits. The neointimal formation triggered by balloon-mediated vascular injury was suppressed significantly and dose-dependently by locally infused suramin, and the intima to media area ratios of the control and 1 mM suramin-treated animals were 48.8+/-14.9 and 12.2+/-6.0%, respectively (p < 0.01. n = 6 for each group). These results suggest that one time local administration of suramin was sufficient to suppress neointimal formation after balloon-mediated vascular injury, and that pharmacological intervention targeting the growth factor's signaling pathways could be a promising approach to prevent smooth muscle cell proliferation in various proliferative vascular diseases.

Effect of cyclosporine A on the gastrointestinal absorption of acyclovir in neonatal and adult rats

The effect of cyclosporine A (CyA) on the pharmacokinetics of acyclovir in neonatal and adult rats was studied. CyA at 25 and 50 mg/kg for 2-week-old and adult rats, respectively, given as a subcutaneous injection, reduced growth of the 2-week-old rats and inhibited growth of adult rats. The plasma concentration of acyclovir after intravenous administration (20 mg/kg) to neonatal CyA-treated rats increased and the total body clearance decreased compared with the neonatal controls. The bioavailabilities of acyclovir for neonatal control and CyA-treated rats after oral administration were significantly different at 15.6 and 22.0%, respectively, but those for the adult control and CyA-treated rats were the same at 15.6 and 14.0%, respectively. Experiments using the everted sac method showed that the amount of acyclovir transferred was higher in neonatal CyA-treated rats than the controls, but there was no difference in adult rats. A good relationship was observed between the bioavailabilities (in vivo) and cumulative transferred amounts (in vitro) in CyA-treated and control rats. Lactase activity in the brush border membrane of the intestine in the neonatal CyA-treated rats was significantly higher than in the controls. These results suggest that the gastrointestinal maturation of CyA-treated neonates is suppressed, resulting in increased bioavailability of acyclovir, while the gastrointestinal absorption of acyclovir does not differ between adult CyA-treated and control rats.

Characterization of follistatin isoforms in early Xenopus embryogenesis

Follistatin is expressed in Spemann's organizer in the Xenopus gastrula and mimics the activity of the organizer, inducing a neural fate directly in the ectoderm. We have previously shown that follistatin inhibits BMP activity through a direct interaction. In this study, we have characterized the localization and function of two follistatin isoforms to examine the functional differences between them. One notable difference, previously described, is that the shorter form (xFSS or xFS319) but not the C-terminally extended long form (xFSL) associates with cell-surface matrices. Here, we show that the spatial-temporal expression pattern of xFSL and xFSS is indistinguishable. Interestingly, however, xFSS was found to have a more potent inhibitory activity against BMP-4 than xFSL. Furthermore, using a surface plasmon resonance biosensor, xFSS was shown to have a higher binding capacity for BMP subtypes. The diffusion rates of xFSS and xFSL ectopically expressed in Xenopus embryos were similar. Taken together, our results suggest that the difference in BMP-inhibiting activity of the two follistatin isoforms is mainly attributable to a difference in their BMP binding properties rather than to their diffusion rates.

Requirement of Xmsx-1 in the BMP-triggered ventralization of Xenopus embryos

Signaling triggered by polypeptide growth factors leads to the activation of their target genes. Several homeobox genes are known to be induced in response to polypeptide growth factors in early Xenopus development. In particular, Xmsx-1, an amphibian homologue of vertebrate Msx-1, is well characterized as a target gene of bone morphogenetic protein (BMP). Here, using a dominant-negative form of Xmsx-1 (VP-Xmsx-1), which is a fusion protein made with the virus-derived VP16 activation domain, we have examined whether Xmsx-1 activity is required in the endogenous ventralizing pathway. VP-Xmsx-1 induced a secondary body axis, complete with muscle and neural tissues, when overexpressed in ventral blastomeres, suggesting that Xmsx-1 activity is necessary for both mesoderm and ectoderm to be ventralized. We have also examined the epistatic relationship between Xmsx-1 and another ventralizing homeobox protein, Xvent-1, and show that Xmsx-1 is likely to be acting upstream of Xvent-1. We propose that Xmsx-1 is required in the BMP-stimulated ventralization pathway that involves the downstream activation of Xvent-1.

Isolation and characterization of bone morphogenetic protein-binding proteins from the early Xenopus embryo

Using a surface plasmon resonance biosensor as a sensitive and specific monitor, we have isolated two distinct bone morphogenetic protein (BMP)-binding proteins, and identified them as lipovitellin 1 and Ep45, respectively. Lipovitellin 1 is an egg yolk protein that is processed from vitellogenin. Both vitellogenin and Ep45 are synthesized under estrogen control in the liver, secreted, and taken up by developing oocytes. In this paper, we have shown that of the TGF-beta family members tested, Ep45 can bind only to BMP-4, whereas lipovitellin 1 can bind to both BMP-4 and activin A. Because of this difference in specificity, we have focused on and further studied Ep45. Kinetic parameters were determined by surface plasmon resonance studies and showed that Ep45 associated rapidly with BMP-4 (k(a) = 1.06 x 10(4) M(-1)s(-1)) and dissociated slowly (k(d) = 1.6 x 10(-4) s(-1)). In Xenopus embryos microinjected with Ep45 mRNA, Ep45 blocked the ability of follistatin to inhibit BMP activity and to induce a secondary body axis in a dose-dependent manner, whereas it had no effect on other BMP antagonists, chordin and noggin. These results support the possibility that Ep45 interacts with BMP to modulate its activities in vivo.

Enhanced GRK5 expression in the hearts of cardiomyopathic hamsters, J2N-k

GTP binding protein-coupled receptor kinase 5 (GRK5) cDNA was cloned from the hearts of Syrian hamsters. The hamster GRK5 cDNA contained 1770 nucleotides encoding 590 amino acids, and the nucleotide sequence had 89.6% homology to the human homologue. An inbred cardiomyopathic hamster strain, J2N-k, was used to investigate the alteration of GRK5 mRNA expression in the setting of congestive heart failure. M-mode echocardiography revealed significant dilatation of the left ventricle and a decrease of left ventricular contractility in 20-week-old J2N-k hamsters compared with age-matched control hamsters, J2N-n. Semi-quantitative RT-PCR showed that GRK5 mRNA expression in the hearts of J2N-k was significantly higher than in those of J2N-n (J2N-k 60.3 +/- 13.3, J2N-n 25.8 +/- 17.2 arbitrary units, p < 0.005, n = 6 in each group). These results suggest that an enhanced GRK5 expression might play a role in the reduced responsiveness to catecholamines in failing hearts via beta-adrenergic receptor phosphorylation.

The potential angiogenic role of macrophages in the formation of choroidal neovascular membranes

PURPOSE

To investigate the distribution of inflammatory mediators such as interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha and angiogenic cytokines such as vascular endothelial growth factor (VEGF) and to identify their cellular source in surgically excised choroidal neovascular membranes (CNVMs) of various origins.

METHODS

Immunoperoxidase staining was performed on paraffin-embedded sections of 11 surgically excised CNVMs to identify cellular distribution and localization of cytokines. Immunofluorescent double staining was performed to detect the cellular source of cytokines.

RESULTS

Cytokeratin-positive cells were detected in the RPE layer, in stromal cells, and around neovascular vessels. Macrophages identified by their cellular marker CD68 showed almost the same distribution as cytokeratin-positive cells, although they were most prominent in the stroma. A substantial number of neovascular vessels were also immunoreactive to IL-1beta and TNF-alpha. Immunofluorescent double staining revealed that the RPE layers immunopositive for cytokeratin were also immunopositive for all cytokines, whereas stromal cells immunostained for CD68 were positive for IL-1beta and TNF-alpha, but not for VEGF.

CONCLUSIONS

These results indicate that IL-1beta and TNF-alpha secreted by macrophages may promote, at least in part, angiogenesis in CNVMs by stimulating VEGF production in RPE cells.

A BMP-inducible gene, dlx5, regulates osteoblast differentiation and mesoderm induction

Bone morphogenetic proteins (BMPs), members of the transforming growth factor beta superfamily, have been identified by their ability to induce cartilage and bone from nonskeletal cells and have been shown to act as a ventral morphogen in Xenopus mesoderm. We isolated a murine homeobox-containing gene, distal-less 5 (mDlx5), as a BMP-inducible gene in osteoblastic MC3T3-E1 cells. Stable transfectants of MC3T3-E1 that overexpress mDlx5 mRNA showed increase in various osteogenic markers, a fourfold increase in alkaline phosphatase activity, a sixfold increase in osteocalcin production, and appearance in mineralization of extracellular matrix. Furthermore, mDlx5 was induced orthotopically in mouse embryos treated with BMP-4 and in fractured bone of adult mice. Consistent with these observations, we also found that injection of mDlx5 mRNA into dorsal blastomeres enhanced the ventralization of Xenopus embryos. These findings suggest that mDlx5 is a target gene of the BMP signaling pathway and acts as an important regulator of both osteogenesis and dorsoventral patterning of embryonic axis.

A critical role for the optic vesicle in lens development; a reinvestigation of free lens formation in Cynops pyrrhogaster

The role of the optic vesicle in lens development was reinvestigated in Cynops pyrrhogaster. To study the necessity for the optic vesicle in early lens development, the optic anlages of stage 17-27 embryos were ablated and the frequency of free lens formation was examined with lens specific markers. Free lens formation was not observed when operations were performed prior to contact between the head surface epidermis and the optic vesicle (stages 17-18). On the contrary, free lens formation occurred in all cases where the optic vesicles were removed after the initiation of lens placode formation in the head surface epidermis (stage 27). However, no lens fiber formation was observed in these free lenses as judged by the absence of lens fiber specific gene expression, namely gamma-crystallin, at stages when secondary lens fiber formation could be found in the control lenses of the unoperated sides. The pattern of expression of alpha A-crystallin in the developing free lens also differed from that of the normally developing lens. This paper is the first report to indicate that the coordinated and sequential expression of crystallin genes are influenced by the optic vesicle; the optic vesicle is required for proper regulation of the alpha A- and gamma-crystallin but not beta B1-crystallin genes.

Direct binding of follistatin to a complex of bone-morphogenetic protein and its receptor inhibits ventral and epidermal cell fates in early Xenopus embryo

In early development of Xenopus laevis, it is known that activities of polypeptide growth factors are negatively regulated by their binding proteins. In this study, follistatin, originally known as an activin-binding protein, was shown to inhibit all aspects of bone morphogenetic protein (BMP) activity in early Xenopus embryos. Furthermore, using a surface plasmon resonance biosensor, we demonstrated that follistatin can directly interact with multiple BMPs at significantly high affinities. Interestingly, follistatin was found to be noncompetitive with the BMP receptor for ligand binding and to form a trimeric complex with BMP and its receptor. The results suggest that follistatin acts as an organizer factor in early amphibian embryogenesis by inhibiting BMP activities by a different mechanism from that used by chordin and noggin.

Specific retinal diacylglycerol and protein kinase C beta isoform modulation mimics abnormal retinal hemodynamics in diabetic rats

PURPOSE

Elevation of diacylglycerol (DAG) and protein kinase C (PKC) levels in diabetic vascular tissue is associated with abnormalities of retinal and renal hemodynamics. The object of this study was to determine whether direct elevation of retinal DAG levels, in the absence of diabetes or hyperglycemia, can mimic the hemodynamic abnormalities normally observed in diabetic rats. Retinal DAG levels were elevated using an inhibitor of DAG kinase that converts DAG to phosphatidic acid. The effectiveness of a specific PKC-beta isoform inhibitor introduced directly into the retinas of diabetic rats in reversing diabetes-related abnormal retinal hemodynamics was also investigated.

METHODS

For retinal blood flow studies, diacylglycerol kinase (DGK) inhibitor R59949, at various concentrations, was injected into the vitreous of nondiabetic Sprague-Dawley rats (n = 33), and a PKC-beta isoform-selective inhibitor LY333531 was injected into the vitreous of rats with streptozotocin (STZ)-induced diabetes of 2 weeks' duration (n = 21). Retinal hemodynamic changes were quantitated using video-based fluorescein angiography. Total DAG levels were assayed from five nondiabetic rat retinas after DGK inhibition and retinal PKC activities were assayed from six diabetic rat retinas after PKC-beta inhibition.

RESULTS

DGK inhibitor R59949 injected into the vitreous dose dependently increased the mean circulation time (MCT) and decreased retinal blood flow (EC50 = 10(-8) M). After 30 minutes, 10(-5) M R59949 induced a 1.7-fold increase in total retinal DAG levels, compared with the levels in vehicle-injected eyes, an increase in MCT from 0.87 +/- 0.05 seconds to 1.44 +/- 0.12 seconds (P < 0.01) and a decrease in retinal blood flow from 105.3 +/- 6.5 pixel2/second to 64.1 +/- 5 pixel2/second (P < 0.01). The effect of R59949 was sustained for 60 minutes after injection. These retinal hemodynamic parameters after DGK inhibition were comparable to those measured at baseline in rats with STZ-induced diabetes of 2 weeks' duration (MCT = 1.38 +/- 0.20 seconds; retinal blood flow = 68 +/- 11.2 pixel2/second). Intravitreal injection of the PKC-beta inhibitor (LY333531) at 10(-5) M in diabetic rats decreased by a factor of 1.6 the diabetes-related increased PKC activation, decreased the prolonged MCT (0.98 +/- 0.13 seconds; P < 0.01) and increased retinal blood flow (93.4 +/- 14.2 pixel2/second; P < 0.01). The measured retinal circulatory parameters after PKC inhibition in the retina were comparable to those measured at baseline in the nondiabetic rats.

CONCLUSIONS

These results provide direct evidence that DAG elevation and subsequent PKC-beta isoform activation are the primary biochemical sequelae responsible for the development of the abnormal retinal hemodynamics observed in diabetic rats.

Vascular endothelial growth factor-induced retinal permeability is mediated by protein kinase C in vivo and suppressed by an orally effective beta-isoform-selective inhibitor

Increased vascular permeability and excessive neovascularization are the hallmarks of endothelial dysfunction, which can lead to diabetic macular edema and proliferative diabetic retinopathy in the eye. Vascular endothelial growth factor (VEGF) is an important mediator of ocular neovascularization and a known vasopermeability factor in nonocular tissues. In these studies, we demonstrate that intravitreal injection of VEGF rapidly activates protein kinase C (PKC) in the retina at concentrations observed clinically, inducing membrane translocation of PKC isoforms alpha, betaII, and delta and >threefold increases in retinal vasopermeability in vivo. The effect of VEGF on retinal vascular permeability appears to be mediated predominantly by the beta-isoform of PKC with >95% inhibition of VEGF-induced permeability by intravitreal or oral administration of a PKC beta-isoform-selective inhibitor that did not inhibit histamine-mediated effects. These studies represent the first direct demonstration that VEGF can increase intraocular vascular permeability through activation of PKC in vivo and suggest that oral pharmacological therapies involving PKC beta-isoform-selective inhibitors may prove efficacious for the treatment of VEGF-associated ocular disorders such as diabetic retinopathy.

Psychiatric manifestations accompanying interferon therapy for patients with chronic hepatitis C: an overview of cases in Japan

Thirty case reports published in Japan that refer to psychiatric symptoms accompanying interferon (IFN) therapy were examined. These papers covered a total of 49 cases. We categorized these 49 cases into 35 cases of mood disorder, 10 of delirium and four of psychotic disorder. The key findings of our study of these cases are as follows: (i) in total, 11 patients had psychiatric past histories: five patients in the mood disorders group were susceptible to the influence of social or psychological factors; (ii) whereas the symptoms of mood disorder or delirium appeared soon after IFN was administered, the symptoms of psychotic disorders appeared later. The patients with delirium displayed many neurological abnormalities, which were reduced by suspending IFN therapy. This suggests the neurological toxicity of IFN; (iii) the outcome of most patients was good; and (iv) we suspect that IFN-induced psychiatric symptoms other than delirium are connected with psychoneuroimmunological functions.

[Verotoxin induced hemolytic uremic syndrome: pathophysiology of neurological involvement]

Hemolytic uremic syndrome (HUS) is caused by endothelial cell damages. Ninety percent of children with HUS have verotoxin-producing E.coli infection. Verotoxin binds to glycolipid receptors globotriaosyl ceramide (Gb3), and the difference of Gb3 expression level in each organ would lead to specific organ involvement. The receptors are expressed in human renal cortex and medulla. The expression level of Gb3 in normal human brain has not been characterized completely. However involvement of central nervous system is a severe complication of HUS. Spreading of microvascular thrombosis caused by combined effects of lipopolysaccharide, cytokine, enhanced shear stress, and verotoxin would play a major role in the development of central nervous dysfunction.

Transient sick sinus syndrome associated with immunoblastic lymphadenopathy

We describe a very rare case of immunoblastic lymphadenopathy (IBL) accompanied with a sick sinus syndrome (SSS) in a 64-year-old male. SSS presented with progression of the IBL and subsided with improvement of the IBL following high dose prednisolone (PSL) therapy. The clinical course of this patient strongly suggested cardiac involvement in IBL and being the cause of the transient SSS. To our knowledge, this is the first case of IBL demonstrating SSS as a possible complication of the disease. This case may provide further information for the treatment of similar patients with IBL.

Regulation of retinal hemodynamics in diabetic rats by increased expression and action of endothelin-1

PURPOSE

To investigate the role of endogenous endothelin-1 (ET-1) expression and its interaction with the ETA receptor in the physiologic regulation of vascular tone as well as in the development of abnormal retinal hemodynamics in diabetes.

METHODS

Retinal blood flow, using digitized video fluorescein angiography recordings, was quantitated after intravitreous injections of ET-1; BQ-123, an ETA receptor antagonist; and phosporamindon, an endothelin converting enzyme inhibitor in the eyes of diabetic and nondiabetic rats. A total of 154 rats were used for these experiments. Message levels of preproendothelin-1 (preproET-1) were measured from the retina of diabetic and nondiabetic rats using competitive polymerase chain reaction (PCR) techniques.

RESULTS

Retinal blood flow was reduced (33%, P < 0.001) in diabetic rats compared to nondiabetic rats. BQ-123, an ETA receptor antagonist, but not saralasin, an angiotensin receptor antagonist, increased retinal blood flow in a dose-dependent manner in diabetic (EC50 of 8 x 10(-7) M) and in nondiabetic rats (EC50 of 8 x 10(-8) M). Besides being resistant to BQ-123, the maximal response in diabetic animals occurred 20 minutes later than in nondiabetic animals. Decreasing ET-1 levels by inhibiting endothelin-converting enzyme with phosphoramidon normalized retinal blood flow in diabetic rats. In nondiabetic rats, the intravitreous injection of exogenous ET-1 (10(-8) M) resulted in retinal blood flow decreases comparable to those measured in diabetic animals, and the subsequent injection of 10(-4) M BQ-123 produced retinal blood flow changes comparable to those measured in BQ-123 injected diabetic rats. Comparison of preproET-1 messenger RNA expression in the retina, brain and lung of control and diabetic rats using quantitative PCR and Northern blot analysis showed 2.0- and 1.7-fold increases in the retina and the brain, respectively, without changes in the lung.

CONCLUSIONS

These data suggest that ET-1 is involved in the regulation of retinal blood flow in normal physiologic outcome, and an increase in the endogenous expression of ET-1 contributes to the reduction of retinal blood flow reported in the early stages of diabetes mellitus.

Endothelin-1 action via endothelin receptors is a primary mechanism modulating retinal circulatory response to hyperoxia

PURPOSE

To determine the role of endothelin (ET)-ETA receptor mediation and endogenous production of endothelin-1 (ET-1) in the retinal response to hyperoxia.

METHODS

Brown-Norway rats (n = 30) were injected intravitreally with an ETA receptor-selective antagonist, BQ-123, and an inhibitor of ET-converting enzyme (ECE), phosphoramidon, and were exposed to a 100% oxygen breathing mixture. Control rats underwent intravitreal injection of vehicle alone (2.5% Emulphor in phosphate-buffered saline). The retinal hemodynamic responses were analyzed using video-based fluorescein angiography (VFA) methodology. Baseline measurements were made with the animals breathing room air, and this was followed by intravitreal injections of the above agents. Subsequent VFA measurements were made after 5, 10, and 15 minutes of breathing 100% oxygen.

RESULTS

The 10 rats injected with vehicle alone demonstrated the expected retinal response to hyperoxia, with significant (P < 0.001) vessel constriction (18% +/- 5%), an increase in retinal mean circulation time (0.84 +/- 0.13 seconds in room air and 1.59 +/- 0.27 seconds in 100% oxygen), and a decrease in blood flow (110.7 +/- 19.2 pixel2/second in room air and 41.9 +/- 9.0 pixel2/second in 100% oxygen), compared to values measured during room air breathing. The hyperoxic response in rats (n = 9) injected with 10(-4) M BQ-123 was significantly (P < 0.001) blunted compared to the group injected with vehicle alone. In contrast, intravitreal injection of saralasin, a specific angiotensin II receptor antagonist, had no significant effect on the retinal response to hyperoxia (n = 5). Intravitreal phosphoramidon (10(-3) M, n = 6) injection also resulted in a significantly (P < 0.001) blunted circulatory response to hyperoxia compared to rats injected with vehicle alone. This blunted response after ECE inhibition was comparable to that measured after ETA receptor antagonism with BQ-123 injection.

CONCLUSIONS

These results demonstrate that the enhancement of ET-1 action, possibly caused by the activation of ECE, plays a primary role in regulating the retinal hemodynamic response to hyperoxia.

Neurofibromatosis complicated with XXX syndrome and renovascular hypertension

A 25-year-old woman with neurofibromatosis was admitted to our hospital for evaluation of hypertension. When she was 6 years old, she was diagnosed as having neurofibromatosis and XXX syndrome because of multiple café-au-lait spots, neurofibromas of the skin and mental retardation. Chromosome analysis revealed that her karyotype was 46, XX/47, XXX. Renal arteriography disclosed aneurysmal change and stenosis of the right renal artery. After right-side nephrectomy and aneurysmectomy, the kidney was autotransplanted in the left iliac fossa. Surgical procedure resulted in marked amelioration of the hypertension without medical treatment. Thus, aortorenal bypass and renal autotransplantation have emerged as the preferred revascularization operations. This is the first report of a chromosomal linkage between neurofibromatosis which is thought to be an autosomal dominant disease and the XXX syndrome.

Amelioration of vascular dysfunctions in diabetic rats by an oral PKC beta inhibitor

The vascular complications of diabetes mellitus have been correlated with enhanced activation of protein kinase C (PKC). LY333531, a specific inhibitor of the beta isoform of PKC, was synthesized and was shown to be a competitive reversible inhibitor of PKC beta 1 and beta 2, with a half-maximal inhibitory constant of approximately 5 nM; this value was one-fiftieth of that for other PKC isoenzymes and one-thousandth of that for non-PKC kinases. When administered orally, LY333531 ameliorated the glomerular filtration rate, albumin excretion rate, and retinal circulation in diabetic rats in a dose-responsive manner, in parallel with its inhibition of PKC activities.

Enhanced expression of beta-adrenergic receptor kinase 1 in the hearts of cardiomyopathic Syrian hamsters, BIO53.58

We cloned an entire encoding sequence of beta-adrenergic receptor kinase 1 (beta ARK1) cDNA from the hearts of Syrian hamsters through reverse transcription and subsequent polymerase chain reaction. The cloned cDNA contained 2067 nucleotides coding 689 amino acids. The sequence had 95% homology to rat beta ARK1 and 90% homology to human homologue. Cardiomyopathic Syrian hamster, BIO53.58, has been used as a model animal of congestive heart failure. M-mode echocardiography confirmed that left ventricular contractility of 20-week-old BIO53.58 was markedly reduced. The expression of beta ARK1 mRNA in the hearts of BIO53.58 was significantly increased compared to control hamsters, F1b, suggesting that the enhanced beta ARK1 expression is acting as a negative feedback mechanism in order to maintain intracellular homeostasis against accelerated stimulation by catecholamines via phosphorylation of beta-adrenergic receptor.

A new approach for evaluation of left ventricular diastolic function: spatial and temporal analysis of left ventricular filling flow propagation by color M-mode Doppler echocardiography

OBJECTIVES

To evaluate left ventricular diastolic function and differentiate the pseudonormalized transmitral flow pattern from the normal pattern, the propagation of left ventricular early filling flow was assessed quantitatively using color M-mode Doppler echocardiography.

BACKGROUND

Because the propagation of left ventricular early filling flow is disturbed in the left ventricle with impaired relaxation, quantification of such alterations should provide useful indexes for the evaluation of left ventricular diastolic function.

METHODS

Study subjects were classified into three groups according to the ratio of early to late transmitral flow velocity (E/A ratio) and left ventricular ejection fraction: 29 subjects with an ejection fraction > or = 60% (control group); 34 with an ejection fraction < 60% and E/A ratio < 1 (group I); and 25 with ejection fraction < 60% and E/A ratio > or = 1 (group II). The propagation of peak early filling flow was visualized by changing the first aliasing limit of the color Doppler signals. The rate of propagation of peak early filling flow velocity was defined as the distance/time ratio between two sampling points: the point of the maximal velocity around the mitral orifice and the point in the mid-left ventricle at which the velocity decreased to 70% of its initial value. High fidelity manometer-tipped measurement was performed in 40 randomly selected subjects.

RESULTS

The rate of propagation decreased in groups I and II compared with that in the control group (33.8 +/- 13.8 [mean +/- SD] and 30.0 +/- 8.6 vs. 74.3 +/- 17.4 cm/s, p < 0.001, respectively) and correlated inversely with the time constant of left ventricular isovolumetric relaxation and the minimal first derivative of left ventricular pressure (peak negative dP/dt) (r = 0.82 and r = 0.72, respectively).

CONCLUSIONS

Spatial and temporal analysis of filling flow propagation by color M-mode Doppler echocardiography was free of pseudonormalization and correlated well with the invasive variables of left ventricular relaxation.

Reversal of abnormal retinal hemodynamics in diabetic rats by acarbose, an alpha-glucosidase inhibitor

Acarbose is an inhibitor of intestinal alpha-glucosidase and has been reported to decrease blood glucose concentrations and glycosuria in diabetic patients and animals. In this study we investigated whether this drug could prevent the abnormalities detected in retinal circulation of diabetic rats. Longitudinal paired studies were performed and the changes in retinal circulation were analyzed using video based fluorescein angiography (VFA) methodology in the same animal. Baseline VFA recordings were obtained from 41 rats. These rats were separated into 4 different groups: In group A (n = 12), diabetes was induced by streptozotocin (STZ) injection and the rats were fed with acarbose (40 mg/100 g powdered chow) mixed into regular rat chow; In group B (n = 10), diabetes was induced by STZ injection and the rats were fed with normal chow; In group C (n = 9), the non-diabetic rats were fed with acarbose; In group D (n = 10), the non-diabetic rats were fed with normal chow. At the end of 2 weeks, all rats again underwent VFA recordings. Blood glucose levels and body weights of rats were monitored during the experiment. The mean blood glucose concentration of Group B was raised from 98.5 +/- 8.7 to 342 +/- 30 mg/dl after STZ injection while in Group A, this change in glucose level was partially ameliorated by acarbose (from 102 +/- 15 to 247 +/- 48 mg/dl). In Group C and D, the blood glucose levels were not significantly changed during the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

[Unconsciousness due to hyponatremia in a patient with short stature with panhypopituitarism]

An unconscious woman of short stature (141 cm) was admitted to our hospital in March, 1994. She had hyponatremia (120 mEq/l) and had experienced massive bleeding during delivery. No increment of either plasma ACTH or cortisol levels was observed after insulin-induced hypoglycemia. However, urinary 17OHCS levels gradually increased after repeated intramuscular injections of ACTH. Plasma free T3 and free T4 levels were low. Neither plasma TSH nor prolactin (PRL) levels increased after an intravenous injection of TRH. Basal plasma LH, FSH and growth hormone (GH) levels were low and there were no observable responses to any of the stimulation tests. A magnetic resonance image (MRI) of her pituitary gland showed an empty sella. These results showed that she had a panhypopituitarism with primary empty sella. Replacement therapy with glucocorticoid was started and serum sodium levels normalized immediately. Levothyroxine was also administered. The possibility of pituitary dwarfism during her youth and a gradual postpartum reduction of other pituitary hormones may have caused an impairment of the hypothalamo-pituitary-adrenal axis.

[Complete remission induced by combined treatment with all-trans retinoic acid (ATRA) and granulocyte colony-stimulating factor (G-CSF) in a patient with relapsed acute promyelocytic leukemia]

In February, 1990, a 49-year-old man was admitted with petechia and gingival bleeding. The peripheral blood showed 5,200 leukocytes/microliters including 73% abnormal promyelocytes and 24,000/microliters platelets. Bone marrow puncture revealed that nucleated cell count was 331,250/microliters including 85.4% abnormal promyelocytes with 46XY, i(17q) chromosome. Coagulation tests revealed DIC. He was diagnosed as having acute promyelocytic leukemia, and he was treated with the BHAC-DMP protocol. He achieved complete remission, and received consolidation therapy and maintenance therapy. However, he relapsed in May, 1991 with 46XY, 16q-, i (17q) chromosome. He was treated with BHAC-MV protocol and again achieved complete remission. In June, 1992, he re-relapsed and 3.6% blasts and 10% abnormal promyelocytes was found in his bone marrow. He was treated for 14 days with 15 mg Aclarubicin without any change. Then he was treated with 60 mg All-trans retinoic acid (ATRA). After administration of ATRA, his peripheral blood leukocyte count increased temporarily but bone marrow suppression continued. Then he received continuous subcutaneous infusion of 24 micrograms/day granulocyte colony-stimulating factor (rhG-CSF). After treatment with ATRA and rhG-CSF, he entered a third complete remission.

Effect of daily subcutaneous administration of recombinant erythropoietin on chronic anemia in rheumatoid arthritis

Mean (+/- SD) serum erythropoietin (EPO) levels were 18.6 +/- 5.6 mU/ml in 180 normal Japanese subjects. Serum EPO levels were elevated with a negative correlation on a log scale (r = -0.864, P < 0.005) to hematocrit (Ht) values in anemic patients not associated with rheumatoid arthritis (RA) or chronic renal failure (CRF). Serum EPO levels in patients with RA (31.6 +/- 16.4 mU/ml) were relatively lower than those in normal subjects and anemic patients without RA or CRF when matched for comparative Ht values. Seven anemic patients with RA were treated by daily subcutaneous (sc) injection of recombinant EPO (rEPO, 500-1,000 U/day) for 4 weeks. The patients had initial Ht values of 25.1% or less and maintained stable clinical status. The treatment with rEPO raised serum EPO levels (53.8 +/- 15.2 mU/ml, P < 0.05), which resulted in an increase in Ht values (more than 3%) in 6 out of 7 patients with RA. The mean (+/- SD) Ht values at the end of the treatment with rEPO (500-1,000 U/day) were greater than those before the treatment in the 7 patients with RA (28.5 +/- 4.6 vs. 22.7 +/- 2.5%, P < 0.05). These findings suggest that chronic anemia associated with RA may be corrected by daily sc injection of a small dose of rEPO.

Chronic idiopathic thrombocytopenic purpura complicated by chronic disseminated intravascular coagulation associated with abdominal aortic aneurysm

A patient with chronic idiopathic thrombocytopenic purpura (ITP), chronic disseminated intravascular coagulation (DIC) and abdominal aortic aneurysm is described. He had severe thrombocytopenia and his platelet life span was shortened (29 h). Indium 111-labeled platelet scintigraphy demonstrated an increased accumulation of radioactivity over the aneurysm and the spleen. Following preoperative heparin therapy for DIC, the platelet count remained low (10 x 10(9)/l), while the DIC improved. Because of the elevated platelet-associated IgG, we considered that the patient had complicated chronic ITP. After intravenous immunoglobulin therapy, his platelet count increased. The aneurysm was successfully replaced with an artificial Y-graft vessel and a splenectomy was performed at the same time. The platelet count was maintained at about 60 x 10(9)/l after the operation and the patient is quite well now.

[A case of Cushing's disease associated with a non-functioning adrenal tumor]

A 52-year-old woman was admitted to our hospital for further examination of central obesity, hypertension and hirsutism suggesting Cushing's syndrome. Hirsutism had been remarkable for two years, and muscle weakness of the lower extremities gradually developed during the past year. CT scan revealed a tumor in the left adrenal gland which was 1 cm in diameter, round, well-circumscribed, homogeneous and not enhanced. Endocrine data disclosed increased urinary 17-OHCS (11.5-16.4 mg/day) and elevated plasma ACTH (125 pg/ml) and cortisol (19 micrograms/dl) with a lack of diurnal rhythm. Administration of the single-dose dexamethasone (1mg) did not suppress plasma cortisol. However, consecutive administration of either 2mg or 8mg of dexamethasone for 2 days suppressed both plasma cortisol and urinary 17-OHCS. Administration of metyrapone raised both urinary 17-OHCS and plasma ACTH levels. Rapid ACTH test resulted in a hyperresponse of plasma cortisol. CRF injection raised plasma ACTH and cortisol. Bilateral adrenal glands were well demonstrated by 19-iodocholesterol (I-131) scintigraphy during the administration of dexamethasone. MRI with Gd-contrast revealed a microadenoma in the sella turcica. With the diagnosis of Cushing's disease, the microadenoma was removed by the transsphenoidal approach and adrenal function was normalized. However, the left adrenal tumor remained on CT scan but was not demonstrated by scintigraphy. These findings indicate that this is a very rare case of Cushing's disease which was associated with an unilateral non-functioning adrenal tumor.

[Effect of subcutaneous administration of interleukin-1 beta on blood platelet count and serum GM-CSF in patients with myelodysplastic syndrome and aplastic anemia]

Subcutaneous administration of recombinant human Interleukin-1 beta (IL-1 beta) in a dose of 1-3 x 10(4) U/day for 14 to 72 days resulted in an increase in circulating granulocytes and bone marrow monocytes in all the 4 patients examined. Circulating platelet count was also increased in two of four patients with myelodysplastic syndrome (MDS) and aplastic anemia (AA). Bone marrow examination revealed an increase in megakaryocyte count in these patients, whereas the percentage of blast was not changed. An increase in blood platelet count was accompanied by an increase in serum GM-CSF in a patient with AA, whereas serum IL-6 level was not changed throughout the treatment with IL-1 beta. These findings suggest that IL-1 beta may be useful for the treatment of a proportion of patients with MDS and AA who are associated with thrombocytopenia.

[Clinical use of serum erythropoietin determination by the recombigen EPO RIA kit]

Serum erythropoietin (EPO) levels were determined by the recombigen EPO RIA kit (DPC) in normal subjects and patients with renal dysfunction, diabetes mellitus, hypothyroidism and a variety of hematological disorders. Mean (+/- SD) serum EPO levels were 18.6 +/- 5.6 mU/ml in 180 normal subjects and no sex difference was obtained. Serum EPO levels in older subjects were slightly greater than those in younger subjects. There was a negative correlation between serum EPO levels and Ht values in anemic patients with normal renal function, whereas serum EPO levels were within the normal range in anemic patients with renal disorders, suggesting that serum EPO levels were relatively low in patients with chronic renal failure. Serum EPO levels were rather increased in patients with diabetes mellitus and hypothyroidism. High serum EPO levels were obtained in patients with a variety of hematological disorders such as acute leukemia, multiple myeloma, myelodysplasia syndrome, aplastic anemia and pure red cell aplasia. In a patient with pure red cell aplasia treated with glucocorticoids, serum EPO levels were lowered before anemia was recovered and reticulocytes were increased. These findings indicate that measurement of serum EPO levels are useful for not only differential diagnosis of anemia but also clinical evaluation of the treatment.

[Acute myelogenous leukemia transformed from myelodysplastic syndrome with tetraploid chromosome constitution]

A 57-year-old female presented with general fatigue. She had neither lymphadenopathy nor hepatosplenomegaly. Laboratory data revealed anemia and leukopenia (1,500/microliters) with a differential count of 4.5% leukemic cells. The myelogram revealed 34.4% leukemic cells, of which diameter ranged from 20 to 28 microns. The diagnosis was acute myelogenous leukemia (FAB: M2) with myelodysplasia. Cytogenetic analysis revealed that the leukemic cells had chromosome abnormalities involving both diploidy and tetraploidy with structural rearrangement. Structural rearrangement included del(5) (q22q33), del(15) (q22q24), and t(3; 12) (q25;p13). Small dose aclacinomycin-A treatment was effective in reducing the number of leukemic cells in bone marrow, and both anemia and leukocytopenia were improved.

[Adult type of idiopathic paroxysmal cold hemoglobinuria]

A 78-year-old female suffered from idiopathic paroxysmal cold hemoglobinuria (PCH). Her symptom occurred immediately after she worked outside in the cold early morning. This case is characterized by the eldest case with non-syphilitic PCH reported in Japan and by the most advanced anemia (Hb 4.2 g/dl) possibly due to prolonged hemolysis after cold exposure. Analysis of the serum revealed positive Donath-Landsteiner antibody of IgG type, which could react to hemolysis not only below 15 degrees C but also at 15-20 degrees C in vitro.

An immunohistochemical study of endocrine cells in the proximal duodenum of eight marsupial species

The proximal duodenum of eight marsupial species, (koala, common brushtail possum, ring-tailed possum, common wombat, great grey kangaroo, parma wallaby, short-nosed bandicoot and tiger cat) were investigated immunohistochemically using 12 specific antisera for gut hormones. Several types of immunoreactive cells were seen on the intestinal villi and in crypts of these species: 9 types in the koala; 8 types in the common brushtail possum; 7 types in the common wombat; 6 types in the short-nosed bandicoot and 5 types in the ringtailed possum, great grey kangaroo, parma wallaby and tiger cat. Gastrin-, somatostatin-, motilin- and serotonin-immunoreactive cells were seen in all species examined. A few BPP-, enteroglucagon-, CCK-, secretin-, GIP- and neurotensin-immunoreactive cells were seen but only in few species. A few substance P-immunoreactive cells were detected only in the koala. Immunoreactive cells were also seen in Brunner's glands: 5 types in the parma wallaby; 3 types in the great grey kangaroo and tiger cat; 2 types in the koala and common wombat; 1 type in the short-nosed bandicoot. No immunoreactive cells were found in Brunner's glands of the common brushtail possum.