Diminished function and expression of the cardiac Na+-Ca2+ exchanger in diabetic rats: implication in Ca2+ overload

1. The present work was carried out in order to determine whether a decrease in cardiac Na+-Ca2+ exchanger (NCX) activity observed in diabetes is caused by a reduction in NCX protein and mRNA levels and to elucidate the significance of this decrease in alterations in [Ca2+]i homeostasis in diabetic cardiomyocytes. 2. The NCX current was significantly reduced in ventricular myocytes freshly isolated from streptozotocin-induced diabetic rat hearts, and its current density was about 55 % of age-matched controls. 3. Diabetes resulted in a 30 % decrease in cardiac protein and mRNA levels of NCX1, a NCX isoform which is expressed at high levels in the heart. 4. The reduced NCX current and the decreased protein and mRNA levels of NCX1 in diabetes were prevented by insulin therapy. 5. Although both diastolic and peak systolic [Ca2+]i were not different between the two groups of myocytes, increasing external Ca2+ concentration to high levels greatly elevated diastolic [Ca2+]i in diabetic myocytes. Inhibition of NCX by reduction in extracellular Na+ by 50 % could produce a marked rise in diastolic [Ca2+]i in control myocytes in response to high Ca2+, as seen in diabetic myocytes. However, cyclopiazonic acid, an inhibitor of sarcoplasmic reticulum Ca2+ pump ATPase, did not modify the high Ca2+-induced changes in diastolic [Ca2+]i in either control or diabetic myocytes. 6. Only in papillary muscles from diabetic rats did the addition of high Ca2+ cause a marked rise in resting tension signifying a partial contracture that was possibly due to an increase in diastolic [Ca2+]i. 7. In conclusion, the diminished NCX function in diabetic myocytes shown in this study results in part from the decreased levels of cardiac NCX protein and mRNA. We suggest that this impaired NCX function may play an important role in alterations in Ca2+ handling when [Ca2+]i rises to pathological levels.

Formula optimization of theophylline controlled-release tablet based on artificial neural networks

Formulation of the controlled-release tablet containing theophylline was optimized based on the simultaneous optimization technique in which an artificial neural network (ANN) was incorporated. As model formulations, 16 kinds of theophylline tablets were prepared. The amounts of Controse, the mixture of hydroxypropylmethyl cellulose with lactose, cornstarch and compression pressure were selected as causal factors. The release profiles of theophylline were characterized as the sum of the fast and slow release fractions. The initial weight, the rate constant in the fast release fraction and the rate constant in the slow release fraction were estimated as release parameters. A set of release parameters and causal factors were used as tutorial data for ANN and analyzed using a computer. Based on the plasma concentration profiles of theophylline predicted by the pharmacokinetic analysis in humans, a desirable set of release parameters was provided. The simultaneous optimization was performed by minimizing the generalized distance between the predicted values of each response and the desirable one that was optimized individually. The optimization technique incorporating ANN showed a fairly good agreement between the observed values of release parameters and the predicted results.

Possible relationship of monocyte chemoattractant protein-1 with diabetic nephropathy

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1) is a specific chemokine to recruit and activate monocytes from the circulation to inflammatory site. In diabetic nephropathy, similar to other glomerulonephropathies, infiltration and activation of monocytes/macrophages in glomerulus have been implicated in the development of glomerular injury. The aim of the present study was to examine a possible relationship of MCP-1 with diabetic nephropathy and to investigate the role of glycated albumin (Gly-Alb) as well as high concentration of glucose (HG) on MCP-1 production by cultured human mesangial cells.

METHODS

MCP-1 in serum or urine and urinary albumin (Alb) as well as several clinical parameters such as plasma glucose, serum Gly-Alb, and hemoglobin A1c (HbA1c) were measured after overnight fasting in 16 control subjects and 54 diabetic patients. The relationships between the levels of urinary Alb and urinary or serum MCP-1 and also between the values of respective clinical parameter and urinary MCP-1 levels were analyzed. Next, using cultured human mesangial cells, we investigated the role of Gly-Alb and/or HG on the gene and protein expression of MCP-1.

RESULTS

Urinary levels (ng/g creatinine), but not serum levels, of MCP-1 increased in accordance with the extent of albuminuria. In all subjects, there were significant correlations between the urinary levels of Alb and MCP-1 (r = 0.746, P < 0.0001) and between the levels of serum Gly-Alb and urinary MCP-1 (r = 0.475, P < 0.0001). In cultured human mesangial cells, the gene and protein expression of MCP-1 was dose and time dependently up-regulated by Gly-Alb. HG slightly but significantly stimulated MCP-1 expression. The combination of Gly-Alb and HG showed the greatest stimulation in more than an additive manner on MCP-1 production.

CONCLUSIONS

This study suggests that facilitated MCP-1 production by mesangial cells in diabetic milieu contributes to the initiation and progression of diabetic nephropathy.

Disruption in the intrathoracic trachea due to blunt trauma

Intrathoracic tracheal disruption by blunt trauma is rare and potentially life threatening. Here report 3 cases of intrathoracic tracheal disruption due to blunt trauma. Two cases, each 43 year old, involved an unrestrained male driver who suffered a head-on crash, while the other, 63 year old, involved a male who suffered compression. Chest roentgenograms on admission showed remarkable deep cervical and mediastinal emphysema in Cases 1 and 2 and mediastinal emphysema alone in Case 3. Bronchoscopy revealed disruption in the trachea. Primary repair was performed through a right posterolateral thoracotomy in Cases 1 and 3 and through a median sternotomy in Case 2. In all cases the postoperative course was uneventful.

The effects of thiazolidinediones on vascular smooth muscle cell activation by angiotensin II

Angiotensin II (Ang II) stimulates the activation of extracellular signal-regulated kinase (ERK), a subgroup of the mitogen-activated protein kinase (MAPK) family, in cultured vascular smooth muscle cells (VSMC). This ERK activation was recently shown to be a critical regulatory factor for Ang II-mediated migration and growth. It has been demonstrated that the thiazolidinedione troglitazone (TRO) blocked Ang II-induced DNA synthesis and migration in VSMC. Here we provide evidence for TRO to inhibit Ang II-induced ERK activation which was suggested to constitute the mechanism by which this agent blocks Ang II-induced VSMC growth and migration. We have found that pretreatment with PD98059, which selectively blocks the activity of ERK pathway at the level of MAPK kinase, decreased Ang II-induced AP-1 activation and that TRO is capable of inhibiting Ang II-induced AP-1 activation. On the other hand, the other thiazolidinediones pioglitazone (PIO) and rosiglitazone (ROSI) had little effect on Ang II-induced activation of ERK or AP-1, suggesting the inhibitory effects of TRO on VSMC activation by Ang II be independent of the peroxisome proliferator-activated receptor-gamma (PPARgamma) for which thiazolidinediones are ligands. Ang II-induced ERK activation was inhibited by protein kinase C (PKC)-specific inhibitor GF109203X, while TRO was also able to block PKC activator phorbol 12 myristate 13-acetate (PMA)-induced ERK activation. Accordingly, TRO may inhibit Ang II-induced MAPK activation at least partly by an inhibition of PKC. These results support the assumption that by targeting MAPK activation, TRO may inhibits the critical signaling steps leading to restenosis and atherosclerosis that may result in part from dysregulated VSMC growth and migration induced by Ang II.

Role of phospholipase A2 in cholesterol gallstone formation is associated with biliary phospholipid species selection at the site of hepatic excretion: indirect evidence

Phospholipase A2 plays a role in cholesterol gallstone development by hydrolyzing bile phospholipids into lysolecithin and free fatty acids. Lysolecithin and polyunsaturated free fatty acids are known to stimulate the synthesis and/or secretion of gallbladder mucin via a prostanoid pathway, leading to enhancing cholesterol crystal nucleation and growth, and therefore, the action of phospholipase A2 is associated, in part, with bile phospholipid fatty acid. To clarify this hypothesis, we evaluated the effect on bile lipid metastability in vitro of replacing phospholipids with lysolecithin and various free fatty acids. Supersaturated model biles were created with an identical composition (cholesterol saturation index, 1.8; egg yolk lecithin, 34 mM; taurocholate, 120 mM; cholesterol, 25 mM) except for 5%, 10%, or 20% replacement of egg yolk lecithin with a combination of palmitoyl-lysolecithin and a free fatty acid (palmitate, stearate, oleate, linoleate, or arachidonate), followed by time-sequentially monitoring of vesicles and cholesterol crystals using spectrophotometer and video-enhanced differential contrast microscopy. Replacement with hydrophilic fatty acids (linoleate and arachidonate) reduced vesicle formation and promoted cholesterol crystallization, whereas an enhanced cholesterol-holding capacity was evident after replacement with hydrophobic fatty acids (palmitate and stearate). These results indicate that the effect of phospholipase A2 on bile lithogenecity is modulated by the fatty acid species in bile phospholipids, and therefore, that the role of phospholipase A2 in cholesterol gallstone formation is dependent, in part, on biliary phospholipid species selection at the site of hepatic excretion.

Involvement of tyrosine phosphorylation in the positive inotropic effect produced by H(1)-receptors with histamine in guinea-pig left atrium

We investigated the effect of stimulation of H(1)-receptors with histamine on protein tyrosine phosphorylation levels in guinea-pig left atrium and evaluated the influences of tyrosine kinase inhibitors on the positive inotropic effect mediated by H(1)-receptors in this tissue. Histamine induced an increase in tyrosine phosphorylation in four main clusters of proteins with apparent molecular weights of 25, 35, 65 and 150 kDa. Tyrosine phosphorylation of these proteins attained a peak around 2 - 3 min following histamine stimulation and then declined to or below basal levels. Histamine-induced protein tyrosine phosphorylation was antagonized by the H(1)-receptor antagonists mepyramine (1 microM) and chlorpheniramine (1 microM), but not by the H(2)-receptor antagonist cimetidine (10 microM). The positive inotropic effect of histamine was depressed in a concentration-dependent manner by the tyrosine kinase inhibitors tyrphostin A25 (50 to 100 microM) and genistein (10 to 50 microM) but not by the inactive genistein analogue daidzein (50 microM). The positive inotropic effect of isoprenaline was unchanged by tyrphostin A25 and genistein. At a concentration of 1 microM histamine produced a dual-component positive inotropic response composed of an initial increasing phase and a second and late developing, greater positive inotropic phase. Treatment with tyrphostin A25 (100 microM) and genistein (50 microM), but not daidzein (50 microM), significantly attenuated the two components of the inotropic response, although genistein suppressed the initial component more markedly than the late component. We conclude that increased protein tyrosine phosphorylation may play an important role in initiating at least some part of the positive inotropic effect of H(1)-receptor stimulation in guinea-pig left atrium.

Ultrastructural and functional studies of cryopreserved rat lungs for transplantation using a new hyperosmolal solution

One of the most promising approaches for extending the period of tissue or organ preservation is to induce a state of cryopreservation. In this report, to achieve successful lung cryopreservation, we created a new hyperosmolal solution (HOS) containing 10% glycerol and 5% dimethyl sulfoxide (Me2SO). We compared the efficacy of HOS with that of Euro-Collins solution (ECS) in rat lung cryopreservation from an ultrastructural and functional point of view. Using ECS, widespread damage to the air-blood barrier was observed even in the lungs cryopreserved at -10 degrees C. At -196 degrees C, the capillary lumen was obstructed with a mesh-like formation derived from deteriorated endothelial cells. In contrast, using HOS, the cryopreserved lungs at -10 degrees C were characterized by well preserved endothelial cells and basal laminae, despite the existence of focal cytoplasmic swelling of epithelial cells. The endothelial cells and basal laminae were successfully preserved up to -196 degrees C. Considering the survival rates at day 7 after cryopreserved lung transplantation, the grafted left lungs functioned normally only when perfused by and preserved in HOS at -10 degrees C. These findings demonstrate that HOS was effective not only for endothelial cells and basal laminae up to -196 degrees C, but also lung cryopreservation at least up to -10 degrees C.

Restoration of prehension with the double free muscle technique following complete avulsion of the brachial plexus. Indications and long-term results

BACKGROUND

Recent interest in reconstruction of the upper limb following brachial plexus injuries has focused on the restoration of prehension following complete avulsion of the brachial plexus.

METHODS

Double free muscle transfer was performed in patients who had complete avulsion of the brachial plexus. After initial exploration of the brachial plexus and (if possible) repair of the fifth cervical nerve root, the first free muscle, used to restore elbow flexion and finger extension, is transferred and reinnervated by the spinal accessory nerve. The second free muscle, transferred to restore finger flexion, is reinnervated by the fifth and sixth intercostal nerves. The motor branch of the triceps brachii is reinnervated by the third and fourth intercostal nerves to restore elbow extension. Hand sensibility is restored by suturing of the sensory rami of the intercostal nerves to the median nerve or the ulnar nerve component of the medial cord. Secondary reconstructive procedures, such as arthrodesis of the carpometacarpal joint of the thumb, shoulder arthrodesis, and tenolysis of the transferred muscle and the distal tendons, may be required to improve the functional outcome.

RESULTS

The early results were evaluated in thirty-two patients who had had reconstruction with use of the double free muscle procedure. Twenty-six of these patients were followed for at least twenty-four months (mean duration, thirty-nine months) after the second free muscle transfer, and they were assessed with regard to the long-term outcome as well. Satisfactory (excellent or good) elbow flexion was restored in twenty-five (96 percent) of the twenty-six patients and satisfactory prehension (more than 30 degrees of total active motion of the fingers), in seventeen (65 percent). Fourteen patients (54 percent) could position the hand in space, negating simultaneous flexion of the elbow, while moving the fingers at least 30 degrees and could use the reconstructed hand for activities requiring the use of two hands, such as holding a bottle while opening a cap and lifting a heavy object. The results were analyzed to identify factors affecting the outcome.

CONCLUSIONS

The double free muscle procedure can provide reliable and useful prehensile function for patients with complete avulsion of the brachial plexus.

Agonist-dependent difference in the mechanisms involved in Ca2+ sensitization of smooth muscle of porcine coronary artery

This study was undertaken to explore possible signal-transduction mechanisms involved in the Ca2+-sensitizing effects of carbachol and endothelin-1 (ET-1) by using beta-escin-skinned smooth muscle of porcine coronary artery. Pretreatment with C3 exoenzyme of Clostridium botulinum, which selectively inactivates rho p21 by adenosine diphosphate (ADP) ribosylation, resulted in a significant inhibition of ET-1-induced Ca2+ sensitization, but had no effect on carbachol-induced Ca2+ sensitization. Whereas the protein kinase C (PKC) inhibitors calphostin C and staurosporine did not affect the Ca2+-sensitizing effect of carbachol, the tyrosine kinase inhibitors genistein and tyrphostin 25 greatly but incompletely suppressed it. In contrast, the Ca2+-sensitizing effect of ET-1 was significantly inhibited by either calphostin C or genistein. Although the inhibitory effect of calphostin C on ET-1-induced Ca2+ sensitization was less than that of genistein, the effects of calphostin C and genistein were additive. The genistein-sensitive component of ET-1-induced Ca2+ sensitization appeared to include the C3-sensitive one. However, a substantial enhancement by ET-1 of the Ca2+-induced contraction was observed even in the presence of the two inhibitors. In beta-escin-skinned smooth muscle of rabbit mesenteric artery, ET-1-induced Ca2+ sensitization was marginally affected by C3 pretreatment, calphostin C, and genistein. We conclude that, although PKC activation and rho p21 protein-dependent and -independent tyrosine phosphorylation each plays an important role in an increase in myofilament Ca2+ sensitivity, the contributions of these signaling pathways to Ca2+ sensitization are different depending on receptor agonists and tissues used. Furthermore, these data suggest the existence of an as yet undefined signal-transduction mechanism involved in Ca2+ sensitization caused by receptor agonists.

High-glucose-induced nuclear factor kappaB activation in vascular smooth muscle cells

OBJECTIVE

Vascular smooth muscle cell (VSMC) dysfunction plays a role in diabetic macrovasculopathy. This dysfunction may be caused or exacerbated by expression of many of genes potently activated by the transcriptional factor nuclear factor kappaB (NF-kappaB). We have examined whether culture of VSMCs under high glucose conditions to stimulate the diabetic state can lead to the activation of NF-kappaB.

METHODS

NF-kappaB activation was assessed in VSMCs stably transfected with a cis-reporter plasmid containing the NF-kappaB binding sites.

RESULTS

Within 3-h incubation, high glucose (27.5 or 55 mmol/l) alone induced an increase in NF-kappaB activity in VSMCs; this increase was mimicked by mannitol given to deliver the same osmolar stress to the cells. High glucose or mannitol also enhanced TNFalpha-stimulated NF-kappaB activity. Incubation with high glucose for 48 h followed by stimulation with TNFalpha led to a marked potentiation of NF-kappaB activation compared with normoglycemic (5.5 mmol/l) VSMCs exposed to TNFalpha, while mannitol attenuated this effect. A 48-h incubation with high glucose substantially reduced glutathione (GSH) levels compared with normoglycemic VSMCs, whereas mannitol significantly increased GSH levels. An antioxidant N-acetyl-L-cysteine and a selective protein kinase C (PKC) inhibitor GF109203X significantly suppressed the TNFalpha-induced NF-kappaB activation, and abrogated potentiation of TNFalpha-induced NF-kappaB activity caused by high glucose (27.5 mmol/l).

CONCLUSION

These results suggest that acutely high glucose causes alterations in osmolarity leading to activation of NF-kappaB, but that exposure to high glucose for more prolonged times causes changes in antioxidant defences and activation of PKC, which potentiates cytokine activation of NF-kappaB. Further definition of these pathways will help to delineate important signals mediating the aberrant behavior of VSMCs under hyperglycemic/diabetic conditions.

Intrapulmonary sequestration with arterial supply from the left internal thoracic artery: a case report

Pulmonary sequestration is uncommon in the upper lobe. Its arterial supply from the internal thoracic artery is very rare. Reported here is a case of a 20-year-old male whose presenting symptom was recurrent pneumonia. Helical computed tomography (CT) and three-dimensional reconstruction images showed that aberrant arteries arising from the left internal thoracic artery were supplying the area of sequestration and draining into the pulmonary vein. Selective intra-arterial digital substraction angiogram also showed left internal thoracic artery supplying the area of the sequestration. Helical three-dimensional CT is noninvasive and provides as accurate three-dimensional information of the aberrant vascular supply in intrapulmonary sequestration as the angiography.

Associations of self estimated workloads with musculoskeletal symptoms among hospital nurses

OBJECTIVES

To investigate the prevalence of neck, shoulder, and arm pain (NSAP) as well as low back pain (LBP) among hospital nurses, and to examine the association of work tasks and self estimated risk factors with NSAP and LBP.

METHODS

A cross sectional study was carried out in a national university hospital in Japan. Full time registered nurses in the wards (n = 314) were selected for analysis. The questionnaire was composed of items on demographic conditions, severity of workloads in actual tasks, self estimated risk factors for fatigue, and musculoskeletal pain in the previous month. Rate ratios (RRs) and 95% confidence intervals (95% CIs) were calculated by the Cox's proportional hazards model to study the association of pain with variables related to work and demographic conditions.

RESULTS

The prevalences of low back, shoulder, neck, and arm pain in the previous month were 54.7%, 42.8%, 31.3%, and 18.6%, respectively. The prevalence of musculoskeletal symptoms among hospital nurses was higher than in previous studies. In the Cox's models for LBP and NSAP, there were no significant associations between musculoskeletal pain and the items related to work and demographic conditions. The RRs for LBP tended to be relatively higher for "accepting emergency patients" and some actual tasks. Some items of self estimated risk factors for fatigue tended to have relatively higher RRs for LBP and NSAP.

CONCLUSIONS

It was suggested that musculoskeletal pain among hospital nurses may have associations with some actual tasks and items related to work postures, work control, and work organisation. Further studies, however, are necessary, as clear evidence of this potential association was not shown in the study.

Primary cardiac sarcoma: two case reports

Two case reports of primary cardiac sarcoma, which is uncommon, are presented. The first case, a 38-year-old male, complained of chest tightness. Chest roentgenograms showed enlargement of the cardiac shadow and left pleural effusion. Transthoracic echocardiography and chest magnetic resonance imaging showed a tumor in the right atrium, and pericardial effusion. The tumor involved the right atrial wall and interatrial septum, and was partially resected. Pathohistological examination revealed angiosarcoma. He died 1 month later. The second case, a 19-year-old male complained of dyspnea and orthopnea. Chest roentgenograms showed pulmonary congestion. Transthoracic echocardiography showed a large mobile mass in the left atrium. An emergency operation was performed and the tumor was totally resected. Pathohistological examination demonstrated leiomyosarcoma. The postoperative course was uneventful, but the tumor rapidly recurred. Second and third operations were performed at intervals of 2 months. After the third operation, he was treated with radiotherapy. Local recurrence was not found but multiple distant metastases were found 2 months after completion of radiation therapy.

Predominant contribution of the G protein-mediated mechanism to NaF-induced vascular contractions in diabetic rats: association with an increased level of G(qalpha) expression

The purpose of this study was to determine the mechanism responsible for alterations in NaF-induced contractions of blood vessels from streptozotocin-induced diabetic rats. In the presence of AlCl(3), NaF (>/=7.5 mM) produced significantly greater contractions in diabetic aorta and mesenteric artery compared with age-matched controls. Pretreatment with 1 microM nifedipine eliminated the enhanced contractile responses of diabetic vessels to NaF, resulting in no difference in the magnitude of NaF-induced contractions between control and diabetic vessels. In the presence of 100 microM deferoxamine, an Al(3+) chelator, NaF-induced contractions of diabetic vessels were markedly attenuated, whereas only the responses to lower concentrations of NaF were reduced in control vessels. No significant difference was found in the peak amplitude of transient contractions induced by 10 microM cyclopiazonic acid between control and diabetic vessels. The addition of 10 microM okadaic acid produced attenuated contractions in diabetic vessels. These findings indicate no involvement of the inhibitory effects of NaF on endoplasmic reticular Ca(2+)-pump ATPase and protein phosphatases in the genesis of the enhanced responsiveness of diabetic vessels to NaF. Western blot analysis showed a 2.5-fold increase in the expression of G(qalpha) in diabetic aortic membranes. In contrast, the G(ialpha) level was modestly decreased and the G(salpha) and G(betagamma) levels were unchanged in diabetes. The present results suggest that enhanced vascular contractions to NaF in diabetes is attributed predominantly to a G protein-mediated Ca(2+) channel activation that results from markedly increased G(qalpha) expression in vascular tissues under this pathological state.

The preferred source of arginine for high-output nitric oxide synthesis in blood vessels

L-arginine is the substrate for nitric oxide (NO) production by each of the 3 NO synthase (NOS) isoforms encoded by the mammalian genome. Despite the pivotal roles of NO in mammalian physiology and pathophysiology, the source of arginine for NO synthesis is not clearly defined. In this context, it is notable that cell types that do not have a complete urea cycle often possess the urea cycle enzymes argininosuccinate synthase and argininosuccinate lyase; together, these enzymes confer the ability to regenerate arginine from the NOS product, L-citrulline. Herein, the authors summarize evidence to support the view that argininosuccinate synthase and argininosuccinate lyase function in an arginine-citrulline cycle, providing a ready source of arginine for high-output NO synthesis. The arginine-citrulline cycle is induced in vascular cells by the same cytokines that trigger iNOS expression and provides the preferred source of substrate for NO production. Evidence suggests that argininosuccinate synthase activity is rate-limiting to high-output NO synthesis and, hence, represents a novel target for the treatment of pathophysiological conditions arising from NO overproduction.

[Blunt rupture of the intrapericardial inferior vena cava: report of two cases]

Blunt rupture of the intrapericardial inferior vena cava is rare. Our experience in recent two cases is presented. Case 1: A 52-year-old male was admitted following a traffic accident. Chest CT demonstrated cardiac tamponade and mediastinal hematoma. Ruptures of the right and left atria across the caudal aspect of the atrial septum, and a separate laceration of intrapericardial IVC were found in the emergency operation. Case 2: A 35-year-old male jumped from the fourth floor of a building. Chest CT revealed descending aortic rupture and the patient was taken to surgery. He died of massive hemorrhage from the aortic rupture. Exploration revealed a rupture of intrapericardial IVC. Recent literatures were reviewed and the mechanism of IVC rupture is discussed.

Collagenolytic and gelatinolytic matrix metalloproteinases and their inhibitors in basal cell carcinoma of skin: comparison with normal skin

Tissue from 54 histologically-identified basal cell carcinomas of the skin was obtained at surgery and assayed using a combination of functional and immunochemical procedures for matrix metalloproteinases (MMPs) with collagenolytic activity and for MMPs with gelatinolytic activity. Collagenolytic enzymes included MMP-1 (interstitial collagenase), MMP-8 (neutrophil collagenase) and MMP-13 (collagenase-3). Gelatinolytic enzymes included MMP-2 (72-kDa gelatinase A/type IV collagenase) and MMP-9 (92-kDa gelatinase B/type IV collagenase). Inhibitors of MMP activity including tissue inhibitor of metalloproteinases-1 and -2 (TIMP-1 and TIMP-2) were also assessed. All three collagenases and both gelatinases were detected immunochemically. MMP-1 appeared to be responsible for most of the functional collagenolytic activity while gelatinolytic activity reflected both MMP-2 and MMP-9. MMP inhibitor activity was also present, and appeared, based on immunochemical procedures, to reflect the presence of TIMP-1 but not TIMP-2. As a group, tumours identified as having aggressive-growth histologic patterns were not distinguishable from basal cell carcinomas with less aggressive-growth histologic patterns. In normal skin, the same MMPs were detected by immunochemical means. However, only low to undetectable levels of collagenolytic and gelatinolytic activities were present. In contrast, MMP inhibitor activity was comparable to that seen in tumour tissue. In previous studies we have shown that exposure of normal skin to epidermal growth factor in organ culture induces MMP up-regulation and activation. This treatment concomitantly induces stromal invasion by the epithelium (Varani et al (1995) Am J Pathol 146: 210-217; Zeigler et al (1996b) Invasion Metastasis 16: 11-18). Taken together with these previous data, the present findings allow us to conclude that the same profile of MMP/MMP inhibitors that is associated with stromal invasion in the organ culture model is expressed endogenously in basal cell carcinomas of skin.

Complete nucleotide sequence of a plant tumor-inducing Ti plasmid

Crown gall tumor disease in dicot plants is caused by Agrobacterium tumefaciens harboring a giant tumor-inducing (Ti) plasmid. Here, for the first time among agrobacterial plasmids, the nucleotide sequence of a typical nopaline-type Ti plasmid (pTi-SAKURA) was determined completely. In total, 195 open reading frames (ORFs) were estimated in the 206479 bp long sequence. 20 genes for conjugation, three for replication, 22 for pathogenesis and 37 for genetic colonization of host plants were found within two-thirds of the plasmid. These genes formed seven functional gene clusters with narrow inter-cluster spaces. In the remaining one-third of the plasmid, novel genes including homologs of mutT, Rhizobium nodQ and Sphingomonas ligE genes were found, which are likely to be responsible for the broad host range. Restriction fragment length variation indicates extreme plasticity of the part required for conjugational gene transfer and the above-mentioned one-third of the plasmid, even among closely related Ti plasmids.

Increase of urocortin-like immunoreactivity in the supraoptic nucleus of Dahl rats given a high salt diet

Urocortin-like immunoreactivity (Ucn-LI) in the supraoptic nucleus (SON) of Dahl rats was examined. Dahl salt-sensitive (S) rats fed with a high salt diet developed hypertension. Numbers of Ucn-LI neurons in the SON in Dahl S on a high salt diet were markedly increased, compared with those in Dahl salt-resistant (R) rats on the same. Sporadic Ucn-LI neurons were found in the SON of both Dahl S and R on a normal diet. Numbers of Ucn-LI neurons in the SON of spontaneously hypertensive rat (SHR) and stroke-prone SHR, genetic models of hypertension, and control rats (Sprague-Dawley and Wistar-Kyoto) were similar. These results suggest that Ucn in the SON is associated with salt loading-induced hypertension rather than spontaneous hypertension.

Terminal warm blood cardioplegia improves the recovery of myocardial electrical activity. A retrospective and comparative study

OBJECTIVE

The effect of terminal warm blood cardioplegia was analyzed in 191 patients undergoing either coronary artery bypass grafting (CABG) or prosthetic heart valve replacement between Jan. 1990 and Dec. 1995.

METHODS

Patients were subdivided into 3 historical cohorts based on the method of myocardial protection: Group A (n = 106), multidose cold crystalloid glucose-potassium cardioplegia, alone; Group B (n = 37), cold crystalloid glucose-potassium cardioplegia plus terminal warm blood cardioplegia, Group C (n = 48), cardioplegia induction with cold crystalloid glucose-potassium cardioplegia, maintenance with multidose cold blood cardioplegia, and terminal warm blood cardioplegia.

RESULTS

Of patients undergoing CABG, 5.6% of group A, 70.4% of group B, and 86.7% of group C spontaneously resumed sinus rhythm after aortic declamping, as did 9.1% of group A, 60.0% of group B, and 55.6% of group C of patients undergoing prosthetic heart valve replacement. The incidence of spontaneous recovery was significantly better in groups B and C than in group A (p < 0.05). Over 90% of patients without terminal warm blood cardioplegia developed ventricular fibrillation or tachycardia requiring electrical cardioversion (p < 0.05). Postoperatively, patients without terminal warm blood cardioplegia required temporary epicardial pacing more frequently than those with terminal warm blood cardioplegia (p < 0.05). In patients undergoing prosthetic heart valve replacement, groups B and C, the incidence of postoperative atrial fibrillation was significantly lower than in group A.

CONCLUSION

Terminal warm blood cardioplegia thus promoted better postoperative electrophysiological cardiac recovery.

Effects of genistein and daidzein on enhanced vascular contractile reactivity and Ca2+ sensitivity in cardiomyopathic hamsters

We investigated the contribution of tyrosine kinase activity to the enhanced vasoreactivity in cardiomyopathic (CM) hamsters. The contractile response of the aorta to phenylephrine was greatly enhanced in CM in comparison to control hamsters. Genistein, a tyrosine kinase inhibitor, did not affect the maximum contractile response to phenylephrine in control aortas, although the sensitivity to phenylephrine was significantly diminished. In contrast, genistein markedly inhibited both the sensitivity and the maximum contractile response to phenylephrine in CM aortas. Daidzein, an inactive form of genistein, also inhibited the sensitivity to phenylephrine in both strains although the maximum contractile response was not altered even in the CM aorta. The Ca2+ sensitivity of tension was significantly augmented in alpha toxin-permeabilized smooth muscle from the mesenteric artery of CM hamsters. Furthermore, phenylephrine enhanced myofilament sensitivity to Ca2+ more in CM than control hamsters. The enhancement of myofilament Ca2+ sensitivity by phenylephrine was markedly inhibited by genistein only in CM hamsters. The inhibition by daidzein of the phenylephrine effect on the Ca2+ sensitivity in CM hamsters was less pronounced. These results suggest that an increase in tyrosine kinase activity may lead to enhanced vascular reactivity in CM hamsters possibly due to an increased Ca2+ sensitivity of the contractile apparatus.

[beta-thalassemia minor diagnosed in a patient with chronic myelogenous leukemia during hydroxyurea therapy]

A 55-year-old man was admitted to our hospital because of leukocytosis and microcytic anemia with hypochromia, target cells, and increased levels of hemoglobin A2 and hemoglobin F. The results of a gene analysis yielded a diagnosis of chronic myelogenous leukemia and beta-thalassemia minor. A gradual increase in hemoglobin was observed during hydroxyurea therapy, which was performed over a 12-week period. This increment appeared to be due to suppressed production of myeloid cells. It was been reported that hydroxyurea increases total hemoglobin due to increased hemoglobin F synthesis in patients with beta-thalassemia. However, hydroxyurea had no clear influence on hemoglobin concentration in this case.

Differential gene transcriptional regulation of Gi isoforms and Gs protein expression in diabetic rat hearts

Many cardiac diseases can be associated with alterations in the function and quantity of G proteins. We examined the gene expressions and protein levels of Gi-1alpha, Gi-2alpha, Gi-3alpha and G(s alpha) in ventricular myocardial preparations from rats 4-6 weeks after induction of diabetes with streptozotocin in comparison with those from age-matched control rats. Diabetic rat myocardium exhibited reductions in the protein levels of Gi-2alpha and Gi-3alpha by 22+/-2% and 57+/-2%, respectively. In diabetes, 22% and 53% reductions in myocardial mRNA levels of Gi-2alpha and Gi-3alpha were observed. Although a faint protein signal of Gi-1alpha was detectable, no apparent expression of mRNA for Gi-1alpha was found in either control or diabetic myocardium. The reduced protein and mRNA levels of Gi-2alpha and Gi-3alpha were prevented by insulin therapy. No change was found in the protein and mRNA levels of G(s alpha) in diabetic myocardium. In conclusion, diabetes leads to a differential regulation of protein expressions of G(i alpha) isoforms and G(s alpha) in ventricular myocardium. The reduced expression of Gi-2alpha and Gi-3alpha proteins can be explained, at least in part, by the decreases in the transcriptional levels.

Increased contractile responses to endothelin-1 and U46619 via a protein kinase C-mediated nifedipine-sensitive pathway in diabetic rat aorta

To determine how diabetes alters vasocontractile responses to endothelin-1 (ET-1) and the thromboxane A2-mimetic U46619 (9,11-dideoxy-9alpha,11alpha-methanoepoxyprostaglandin F2alpha) and to explore the possible mechanisms of the altered responses, contractions produced by these agonists were examined in aortic rings from rats with 8- to 12-weeks streptozotocin-induced diabetes in comparison with those from age-matched control rats. ET-1 (> or = 1 nM) and U46619 (> or = 100 nM) induced significantly greater contractions in diabetic aorta. The enhanced contractile responses of diabetic aorta to these agonists were abolished in the presence of 1 microM nifedipine, resulting in no significant difference in the maximum responses between control and diabetic aortas. Pretreatment with 1 microM calphostin C or 20 nM staurosporine caused marked reductions in contractions induced by ET-1 and U46619 in both control and diabetic aortas, and the difference in the maximum contractile responses to these agonists between control and diabetic aortas were eliminated by their treatment. These results suggest that chronic diabetes enhances aortic contractions induced by ET-1 and U46619 and the enhanced contractions are possibly due to an increased Ca2+ influx through transmembrane Ca2+ channels resulting from increased protein kinase C-activated process.

[Epstein-Barr virus-associated hemophagocytic syndrome during mid-term pregnancy successfully treated with combined methylprednisolone and intravenous immunoglobulin]

A 32-year-old woman in the 16th week of pregnancy was admitted to our hospital because of high fever. Laboratory findings disclosed pancytopenia and extremely elevated serum LDH and ferritin levels. Coagulation tests showed disseminated intravascular coagulation. Serum soluble interleukin-2 receptor, tumor necrosis factor-alpha, and interleukin-6 levels were high, but serum interferon-gamma was below the detectable limit. Reactive Epstein-Barr virus (EBV) infection was diagnosed on the basis of a high titer of IgG antibodies to the EBV capsid antigen and early antigen. EBV was demonstrated in the peripheral blood and bone marrow cells by polymerase chain reaction. Mature histiocytosis and hemophagocytosis were detected in the bone marrow. A diagnosis of EBV-associated hemophagocytic syndrome (EBV-AHS) was made. Neither prednisolone (PSL 30 mg/day, P.O.) nor methylprednisolone (m-PSL) pulse therapy (1,000 mg/day for 3 days) induced a response. Thereafter, treatment with m-PSL pulse therapy (1,000 mg/day for 3 days) and i.v. administrations of high-dose immunoglobulin (20 g/day for 3 days) in combination with acyclovir (750 mg/day) and gabexate mesilate (2 g/day) induced remission of the disease. Maintenance therapy consisted of PSL (5 mg/day, P.O.) and camostat mesilate (600 mg/day, P.O.). The patient delivered a healthy male infant in the 35th week of pregnancy via natural birth. Reports of pregnant women with EBV-AHS are rare, and the choice of therapy has not yet been established. The present case study suggested the above combination treatment is useful and safe, and capable of changing the fulminant course of EBV-AHS during pregnancy without the use of anticancer drugs.

A patient with genetic deletion of glutathione-S-transferase T1 and M1 who developed non-small-cell lung cancer and myelodysplastic syndromes

Glutathione S-transferase (GST) M1 polymorphism is a marker for susceptibility to smoking-related neoplasms, such as lung and bladder cancer. Recently, a genetic deletion of GSTT1, an isoenzyme of GST, has been reported to be associated with myelodysplastic syndromes (MDS). A 59-year-old man with a long-term smoking habit was treated successfully for non-small-cell lung cancer. Four years after the surgical removal of his lung cancer, he developed MDS and died. Using a polymerase chain reaction-based genotyping method, he was found to have a deletion of both the GSTM1 and GSTT1 genes. Screening for the deletion of the GSTM1 and GSTT1 genes may be useful for assessing individual genetic susceptibility to smoking-related lung cancer and MDS.

Limb-sparing surgery with reinnervated free-muscle transfer following radical excision of soft-tissue sarcoma in the extremity

Limb-sparing surgery is the preferred approach in the management of patients with high-grade soft-tissue sarcomas when local disease can be completely resected. However, conventional treatment focuses only on restoration of basic functions to the remnant limb. Lost functions are not restored to normal, leaving the patient with variable degrees of functional disabilities. This in turn may necessitate further massive reconstructive procedures. Transferred reinnervated free muscles were used to reconstruct functions lost after radical resection of malignant soft-tissue sarcoma of the extremities in 17 patients. The long-term functional outcome included survival of transplanted muscle, speed of neural recovery, and muscle strength and disabilities. All muscles survived. Postoperative follow-up ranged from 27 to 106 months. All muscles except those in a 75-year-old patient were successfully reinnervated. Powerful strength and almost normal limb functions were obtained. Functional scoring of the patients according to the rating system of the Musculoskeletal Tumor Society was 87 percent for the lower extremity and 93 percent for the upper extremity. All patients are presently disease-free. Use of the reinnervated free-muscle transfer in limb-sparing surgery after resection of soft-tissue sarcoma in the extremity may be indicated in the young adult when radical excision of the tumor will result in severe motor functional loss, provided adequate clearance can be obtained and that there is no presence of distant metastasis.

Cardiac profile of EGIS-9377, a novel cardiotonic agent as a Ca2+ sensitizer with bradycardiac activity

The cardiac profile of EGIS-9377 ¿2-(1-methylthio)-5-(2-morpholinoethylamino)-8,9-dihydro-7H-thi opyrano[3,2-d][1,2,4]triazolo[1,5-a]pyrimidine dihydrochloride¿, a newly synthesized cardiotonic agent, was compared with those of pimobendan and isoprenaline in cardiac preparations isolated from guinea pigs. The positive inotropic potency and efficacy of EGIS-9377 were equal to those of pimobendan in electrically paced papillary muscles, with each agent maximally increasing force of contraction by 30-35% of the maximum effect of isoprenaline. The positive inotropic effects of EGIS-9377 and pimobendan were accompanied by an increase in the relaxation time of the isometric contraction curve, whereas that of isoprenaline was associated with an abbreviation of this parameter. Pimobendan significantly increased the spontaneously beating frequency of right atria, and its positive chronotropic effect amounted to 40% of the maximum effect of isoprenaline. In contrast, EGIS-9377 exerted a significant negative chronotropic action, which resulted in a 30% decrease in the basal frequency. In beta-escin-skinned trabecular muscles, both EGIS-9377 and pimobendan substantially enhanced contractions induced by Ca2+. EGIS-9377 at concentrations to cause a significant negative chronotropic action produced a marked prolongation of action potential duration (APD) in guinea pig papillary muscle and greatly inhibited the delayed rectifier potassium current (I(K)) in guinea pig ventricular single cells. This suggests that the negative chronotropic effect of EGIS-9377 may, at least in part, be due to the prolongation of APD as a result of the I(K) inhibition. The present results indicate that EGIS-9377 efficiently increases myocardial contractile force possibly due to its Ca2+ -sensitizing activity, and yet produces a substantial negative chronotropic action. This cardiac profile of EGIS-9377 is suggested to be a clinically favorable feature compared with the inotropic agents having cyclic AMP generation or phosphodiesterase inhibition as their action mechanisms.

Adrenomedullin augments nitric oxide and tetrahydrobioptein synthesis in cytokine-stimulated vascular smooth muscle cells

OBJECTIVE

Immunostimulants increase nitric oxide (NO) and tetrahydrobiopterin (BH4) synthesis in vascular smooth muscle cells (VSMC) by coinducing expression of an isoform of NO synthase (iNOS) and GTP cyclohydrolase I (GTPCH). GTPCH is the first and rate-limiting enzyme in the synthesis of BH4, a cofactor of NO synthases. Given the adrenomedullin (AM) increases NO production, this effect of AM may involve modulation of BH4 synthesis in cytokine-stimulated VSMC.

METHODS

We investigated the effects of AM on the synthesis of NO and BH4, the expression of iNOS and GTPCH mRNA, and the promoter activity of iNOS and GTPCH genes in rat VSMC stimulated with interleukin-1 (IL-1).

RESULTS

IL-1 increased both NO and BH4 synthesis as well as the abundance of iNOS and GTPCH mRNA. AM significantly increased both NO and BH4 synthesis caused by IL-1 stimulation. AM also augmented the IL-1-induced increase in the abundance of iNOS and GTPCH mRNA. IL-1 activated the iNOS promoter activity as well as the GTPCH promoter activity in VSMC. AM alone had no effect on the activity of either the iNOS or the GTPCH promoter, nor did it potentiate the activation by IL-1 of either of these promoters.

CONCLUSION

These results suggest that AM increases IL-1-induced NO and BH4 synthesis by enhancing the expression of iNOS and GTPCH genes at the post-transcriptional level. Thus, the potentiating effect of AM on NO synthesis appears to be associated with an increased expression of both genes necessary for cellular NO synthesis in VSMC.

Interleukin-6 and transforming growth factor-beta regulate the expression of monocyte chemoattractant protein-1 and colony-stimulating factors in human thyroid follicular cells

Monocytes and T-lymphocytes, both of which play a pivotal role in immune/inflammatory responses, can be attracted from the circulation into tissues by monocyte chemoattractant protein-1 (MCP-1), and monocytes can be further activated by colony-stimulating factors (CSFs), granulocyte/macrophage CSF (GM-CSF) or macrophage CSF (M-CSF). We examined whether either interleukin-6 (IL-6) or transforming growth factor-beta (TGF-beta), both of which are produced by thyroid follicular cells (TFC), can regulate the production of MCP-1 or CSF(s) in human TFC. IL-6, being effective only in the presence of soluble IL-6 receptor (sIL-6R), stimulated the expression of both MCP-1 and M-CSF, but was inhibitory on GM-CSF expression. On the other hand, TGF-beta stimulated the expression of both MCP-I and GM-CSF, but suppressed M-CSF expression. These results suggest a possible role of IL-6 or TGF-beta on the initiation and/or modulation of thyroid immune/inflammatory responses via MCP-1 production and differential production of GM-CSF or M-CSF by TFC.

Diabetes-induced down-regulation of beta1-adrenoceptor mRNA expression in rat heart

The present study addressed the question of whether the number of myocardial beta-adrenoceptors in rats with 4- to 6-week streptozotocin-induced diabetes is regulated in a transcriptional or translational manner. Radioligand binding experiments with [3H]CGP 12177 {4-(3-t-butylamino-2-hydroxypropoxy)-[5,7-3H]benzimidazol-2-one} showed that the density of beta-adrenoceptors fell by 50% with no change in affinity in diabetic rat ventricular myocardium compared with age-matched control myocardium. The relative content of beta1-adrenoceptor mRNA in diabetic myocardium also was reduced from the control level by 57%, as determined by northern blot analysis. The reductions in myocardial beta-adrenoceptor number and beta1-adrenoceptor mRNA observed in diabetes were prevented by insulin therapy. These data indicate that the diminished density of myocardial beta-adrenoceptors in diabetes occurred, at least in part, at the mRNA level.

Preferential impairment of nitric oxide-mediated endothelium-dependent relaxation in human cervical arteries after irradiation

BACKGROUND

Vascular abnormalities are a major cause of postoperative complications in irradiated tissues. Endothelial cell dysfunction characterized by diminished endothelium-dependent relaxation may be involved. We examined the endothelium-dependent relaxation and morphology of the endothelium in irradiated human cervical arteries.

METHODS AND RESULTS

Irradiated arteries were taken from the neck region of patients who had radiation therapy. Arteries from patients who did not receive radiation therapy were used as controls. Endothelium-dependent relaxation to acetylcholine and A23187 was impaired in irradiated arteries. Norepinephrine-induced contraction and sodium nitroprusside-induced relaxation were unchanged. In control arteries, N(omega)-nitro-L-arginine and indomethacin each caused a partial inhibition of endothelium-dependent relaxation. In irradiated arteries, the impaired endothelium-dependent relaxation was unaffected by these agents, but it was abolished by high K(+). Acetylcholine produced similar degrees of hyperpolarization in control and irradiated arteries. Immunohistochemical examination for endothelial nitric oxide synthase indicated no expression in the endothelium of irradiated arteries. Electron scanning microscopy showed morphologically intact endothelial cells in irradiated arteries.

CONCLUSIONS

In irradiated human cervical arteries, the nitric oxide- and prostacyclin-mediated endothelium-dependent relaxation, but not endothelium-derived hyperpolarizing factor-mediated relaxation, are specifically impaired, without significant morphological damage of the endothelium. The impaired nitric oxide-mediated relaxation was associated with a lack of endothelial nitric oxide synthase expression. Our results suggest the importance of impaired endothelial function in irradiated human blood vessels, which may partly explain the development of vascular stenosis and poor surgical wound healing in irradiated tissues.

A close association between insulin resistance and dehydroepiandrosterone sulfate in subjects with essential hypertension

To examine the serum levels of dehydroepiandrosterone sulfate (DHEAS) and its relation with insulin resistance and the other risk factors in essential hypertension, serum DHEAS and insulin sensitivity were assessed in 35 male hypertensive and 17 male healthy control subjects aged 50-59 years. Fasting plasma insulin and the area under curve of plasma insulin were determined during a 75 g oral glucose tolerance test. Insulin sensitivity was measured by the steady state plasma glucose method. Fasting plasma insulin and the area under curve of plasma insulin were significantly higher in the hypertensive group than in control group. Steady state plasma glucose was significantly higher in hypertensive subjects indicating insulin resistance compared with control subjects. On the other hand, fasting serum DHEAS levels were significantly lower in the hypertensive group than in the control group. Fasting serum DHEAS levels were inversely correlated with steady state plasma glucose significantly (p=0.0008), indicating a close association between DHEAS levels and insulin resistance. Fasting serum DHEAS was inversely correlated with systolic blood pressure and fasting plasma insulin. In multiple regression analysis of hypertensive subjects, steady state plasma glucose was the strongest determinant of the fasting serum level of DHEAS, followed by systolic blood pressure and fasting plasma insulin. These 3 factors accounted for 51.6% of the variation in DHEAS. In nonobese and nondiabetic essential hypertension, serum DHEAS was lower and insulin resistance was the most significant independent determinant of reduced serum DHEAS, followed by systolic blood pressure and fasting plasma insulin.

[Dumbbell type schwannoma of the posterior mediastinum: a report of two cases with different surgical approaches]

Two cases of dumbbell type schwannoma of the posterior mediastinum are reported. Case 1 involved a 16-year-old man and case 2, a 48-year-old woman. They were asymptomatic, and in both cases an abnormal mass shadow of the left mediastinum was incidentally detected on a routine chest roentogenogram. In these cases, CT and MRI revealed that dumbbell type tumors extended to the spinal canal. The operations were performed with thoracic approach cooperated with a neurosurgeon in case 1 and with combined posterior and thoracic approach cooperated with an orthopedic surgeon in case 2. Histopathologic findings indicated all benign schwannomas. The reported 25 cases in Japan sofar are reviewed.

Secretion of TNF-alpha, IL-8 and nitric oxide by macrophages activated with polyanions, and involvement of interferon-gamma in the regulation of cytokine secretion

When macrophages derived from rat bone marrow were cultured in the presence of polyanions such as acetyl lignin (EP3), sulfonyl lignin (LS) or dextran sulfate (DS), the cells secreted TNF-alpha, IL-8 and nitric oxide (NO). EP3 had a dose-dependent effect on the secretion of TNF-alpha, IL-8 and NO. EP3 significantly affected secretion at concentrations greater than 5 microg/ml. The EP3 effect was at its maximum between concentrations of 50 and 100 microg/ml. LS and DS induced a slight increase in the secretion of cytokines and NO at a concentration of 100 microg/ml. The use of the reverse-transcription polymerase chain reaction (RT-PCR) showed that the increases in cytokine and NO secretion were due to an increase in cytokine mRNAs or NO synthase mRNA. Anti-TNF-alpha antibodies partially inhibited NO secretion by EP3-activated macrophages, although IL-8 secretion was independent of antibody treatment. The secretion of TNF-alpha and NO was also unaffected by the addition of anti-IL-8 antibodies. The addition of interferon-gamma (IFN-gamma) to the culture medium did not alter TNF-alpha and NO secretion by the EP3-activated macrophages, however, IL-8 secretion was increased when a low concentration of IFN-gamma (0.2 U/ml) was added, but was reduced in the presence of a high concentration of IFN-gamma (2000 U/ml). IFN-gamma produced similar effects on cytokine and NO secretion in macrophages activated with lipopolysaccharide (LPS). Therefore, it is concluded that macrophages treated with polyanions secrete cytokines and NO, and that INF-gamma is involved in the regulatory mechanism of cytokine and NO secretion.

The precise breakpoints of a Filipino-type alpha-thalassemia-1 deletion found in two Japanese

The breakpoints of alpha-thalassemia-1 were thoroughly characterized in two Japanese families. The crossover occurred between Alu repeats at about 1.28 kb 5' to the zeta2 gene and about 1.2 kb 3' to the theta1 gene, resulting in the deletion of a 30.656 kb-long segment. These breakpoints are consistent with those surmised for the "Filipino type (--FIL)" deletion by Southern blot analysis. Also the length of the 3' hypervariable region of the alpha-globin gene conformed to that of --FIL. The two Japanese families are related to the Taiwanese and Filipino families.

Intra-articular fractures of the distal aspect of the radius: arthroscopically assisted reduction compared with open reduction and internal fixation

BACKGROUND

There is no consensus that an arthroscopically guided operation can improve the anatomical and functional results of treatment of intra-articular fractures of the distal aspect of the radius. The purpose of the present prospective study was to determine the usefulness of arthroscopically assisted reduction of displaced intra-articular fractures of the distal aspect of the radius by comparing the results of that procedure with those of conventional open reduction and internal fixation.

METHODS

Thirty-four fractures were treated with arthroscopically guided reduction with use of one volar and two dorsal arthroscopic portals. The fractures were pinned, and external fixation was used with or without autogenous bone graft. Intraoperative fluoroscopy was not used. Forty-eight fractures were treated with conventional open reduction and internal fixation with a plate and screws or with pinning, with or without external fixation. The average duration of follow-up for all fractures was thirty-one months.

RESULTS

The scores for overall outcome, assessed with use of the system of Gartland and Werley and that of Green and O'Brien as modified by Cooney et al., demonstrated that the group that had had an arthroscopically assisted procedure had better outcomes than the group that had had conventional open reduction and internal fixation. The group that had had an arthroscopically assisted procedure also had significantly better ranges of flexion-extension and radial-ulnar deviation of the wrist and grip strength (p<0.05). We detected an association between the maximum step and gap displacement and evidence of osteoarthritis of the radiocarpal joint (p<0.001), but we did not find a significant association, with the numbers available, between the scores for osteoarthritis, graded according to the scale of Knirk and Jupiter, and the scores for overall outcome, assessed with the scale of Gartland and Werley and the modified system of Green and O'Brien, in either group (p = 0.376). The radiographic results showed that the patients who had had an arthroscopically assisted procedure had better reduction of volar tilt, ulnar variance, and articular (gap) displacement than did those who had been managed with conventional open reduction and internal fixation (p<0.05 for each comparison).

CONCLUSIONS

An arthroscopically guided operation achieved an accurate reduction of intra-articular fractures of the distal aspect of the radius. Minimum capsular and adjacent soft-tissue scarring reduced postoperative contracture, which improved the overall functional results. We recommend arthroscopically guided reduction and internal fixation not only for young adults but for all patients who are less than seventy years old and have an intra-articular fracture of the distal part of the radius with more than one millimeter of displacement on plain radiographs.

Influence of cholesterol crystallization effector proteins on vesicle fusion in supersaturated model bile

BACKGROUND

In lithogenic bile, cholesterol-rich vesicles rapidly aggregate and fuse to eventually form cholesterol crystals. This process is modulated by cholesterol crystallization effector substances. In this study, we developed a method for quantitative assessment of vesicle fusion and used it to partly characterize the mechanisms of action of cholesterol crystallization effector proteins.

METHODS

Cholesterol:phospholipid (1:1) liposomes were prepared and labelled with octadecyl rhodamine B chloride (R18). Fusion of these liposomes was detected by the increase of R18 fluorescence after incubation with various proteins, such as albumin, concanavalin-A bound glycoprotein, immunoglobulins, apolipoprotein A-I and apolipoprotein B (all at 100 microg/mL).

RESULTS

Fusion of cholesterol/phospholipid liposomes was increased by 16 and 14% in the presence of concanavalin-A bound glycoprotein and immunoglobulins, respectively, and decreased by 21 and 9% after addition of apolipoprotein A-I and apolipoprotein B, respectively. The effect of each protein on vesicle fusion was correlated with its hydrophobicity.

CONCLUSIONS

These results suggest that nucleation effector proteins modulate the stability of vesicles and, thus, affect cholesterol crystallization. Such modulation is based upon protein-vesicle association, which defines the physico-chemical metastability of vesicular cholesterol.

Effect of prolonged treatment with amlodipine on enhanced vascular contractility in cardiomyopathic hamsters

This study examined the effects of prolonged treatment with amlodipine on the enhanced vascular contractions in dilated cardiomyopathic (CM) hamsters. From the ages of 5 to 20 weeks, CM hamsters (BIO 53.58) orally received amlodipine. Then we compared the contractile responses to vasoconstrictors in aortas and mesenteric arteries from CM hamsters with or without treatment with those in the arteries from controls (F1b). We also investigated the effect of amlodipine treatment on the Ca2+ sensitivity of tension in beta-escin-skinned smooth muscle of mesenteric artery. The contractile responses to phenylephrine, angiotensin II, and high K+ in both aorta and mesenteric artery were greatly enhanced in CM hamsters compared with controls. Amlodipine treatment slightly but significantly inhibited the enhanced responses in aorta but did not alter the responses in mesenteric arteries. The Ca2+ sensitivity of tension was significantly increased in CM hamster preparations, which was unaffected by amlodipine treatment. These data indicate that amlodipine treatment differentially affects the enhanced responses to vasoconstrictors between large and small blood vessels from CM hamsters. The lack of effect of amlodipine treatment on the responsiveness of CM mesenteric artery leads to the suggestion that the preventive effect of amlodipine on focal myocytolytic necrosis of cardiomyocytes, which was previously reported to be the main cause of cardiomyopathy, results from an action on cardiomyocytes.

Relaxation in different-sized rat blood vessels mediated by endothelium-derived hyperpolarizing factor: importance of processes mediating precontractions

To clarify the mechanisms involved in relaxations mediated by endothelium-derived hyperpolarizing factor (EDHF), acetylcholine (ACh)-induced endothelium-dependent relaxations and hyperpolarizations were examined in the rat aorta, the main branch of the mesenteric artery (MBMA) and the first branch of the mesenteric aftery (FBMA). In the presence of 100 microM N(G)-nitro-L-arginine (L-NNA) and 10 microM indomethacin, ACh (1 nM to 100 microM) produced no relaxation in the phenylephrine-precontracted aorta. The L-NNA-resistant relaxations by ACh in MBMA precontracted with phenylephrine were eliminated in the presence of 1 microM nifedipine where contractions were independent of L-type Ca(2+) channel activation. In FBMA precontracted with phenylephrine, the L-NNA-resistant relaxations were only partially inhibited by nifedipine. When vessels had been contracted with 300 nM phorbol-12,13-dibutyrate in the presence of nifedipine, ACh-induced L-NNA-resistant relaxations were observed in FBMA only. Pinacidil produced relaxations in all different-sized blood vessels, although sensitivity was inversely related to vessel size. The extent of the ACh hyperpolarizing responses was much smaller than that by pinacidil in the aorta. The membrane potential changes by ACh and pinacidil were almost the same in FBMA. These results indicate that the contribution of EDHF to endothelium-dependent relaxations increases as the vessel size decreases. This may be partly explained by precontractile processes dependent on Ca(2+) entry through L-type Ca(2+) channels, because Ca(2+) channel deactivation seems to be involved as a major mechanism of EDHF-mediated vasorelaxations. However, EDHF may also generate vasorelaxations by an additional mechanism, probably a reduced Ca(2+) sensitivity of contractile elements, as proposed for ATP-sensitive K(+) channel openers.

Acute traumatic dissection and blunt rupture of the thoracic descending aorta: A case report

Rupture of the thoracic aorta following blunt trauma is increasing in incidence and remains a highly lethal injury. Blunt traumatic rupture and acute dissection of the thoracic aorta is very rare. A 50-year-old man involved in a motor vehicle accident on March 3, 1998 was admitted to our hospital one and a half hours following the accident. On admission, he was alert and his hemodynamics were stable. Chest roentgenogram demonstrated a widened mediastinum and multiple left-sided rib fractures. Enhanced chest CT revealed a periaortic hematoma just distal to the isthmus, dissection of the descending thoracic aorta and mediastinal hematoma. With the diagnosis of thoracic aortic rupture and acute DeBakey type IIIB dissection, an emergency operation was performed. Intraoperative transesophageal echocardiogram showed a mobile intimal flap and diminished caliber of the proximal descending aorta. Disruption and dissection of the descending thoracic aorta were found. Prosthetic graft interposition was accomplished with the aid of left atrium-left femoral artery bypass using a centrifugal pump and heparin-coated circuits and a blood collection device for blood conservation. The weak dissected aortic wall was glued and reapproximated with Gelatine-Resorcine-Formol glue. The postoperative course was uneventful.

Cilnidipine, the N- and L-type calcium channel antagonist, reduced on 24-h urinary catecholamines and C-peptide in hypertensive non-insulin-dependent diabetes mellitus

To evaluate the effects of cilnidipine (CNP), L- and N-type calcium channel blocker and nilvadipine (NVP) on 24-h urinary epinephrine (U-EP), norepinephrine (U-NE), dopamine (U-DA) and C-peptide (U-CPR) in patients associated with hypertension and non-insulin-dependent diabetes mellitus (HT-NIDDM), a randomized crossover study was performed with 35 HT-NIDDM patients. The patients were given CNP (10 mg/day) and NVP (8 mg/day), separately, for 4 weeks each. After CNP treatment, U-NE, U-DA and U-CPR levels were significantly reduced compared with pre-treatment levels: 160.4 +/- 12.7 to 111.7 +/- 8.9 microg/day (mean +/- S.E., P < 0.005); 934.8 +/- 163.4 to 590.3 +/- 33.4 microg/day (P < 0.05); 86.7 +/- 9.9 to 57.6 +/- 7.4 microg/day (P < 0.05), respectively. Although no significant differences were observed in U-EP, U-NE, U-DA and U-CPR levels by NVP treatment, U-NE, U-DA and U-CPR levels after CNP treatment were significantly lower than those after NVP treatment: 111.7 +/- 8.9 versus 155.0 +/- 13.7 microg/day (P < 0.02); 590.3 + 33.4 versus 822.2 +/- 104.3 microg/day (P < 0.05); 57.6 +/- 7.4 versus 80.6 +/- 8.1 microg/day (P < 0.05), respectively. In conclusion, it was demonstrated that CNP treatment significantly reduced U-NE, U-DA and U-CPR excretion compared with NVP treatment in HT-NIDDM patients.