Possible involvement of protein phosphorylation in aluminum-responsive malate efflux from wheat root apex

In many plants, efflux of organic anions from roots has been proposed as one of the major Al resistance mechanisms. However it remains unknown how plants regulate efflux of organic anions in response to Al. In this study, the regulatory mechanisms of Al-responsive malate efflux in wheat (Triticum aestivum) were characterized focusing on the role of protein phosphorylation. Al-resistant wheat (cv Atlas) initiated malate efflux at 5 min after addition of Al, and this response was sensitive to temperature. K-252a, a broad range inhibitor of protein kinases, effectively blocked the Al-induced malate efflux accompanied with an increased accumulation of Al and intensified Al-induced root growth inhibition. A transient activation of a 48-kD protein kinase and an irreversible repression of a 42-kD protein kinase were observed preceding the initiation of malate efflux, and these changes were canceled by K-252a. Malate efflux was accompanied with a rapid decrease in the contents of organic anions in the root apex, such as citrate, succinate, and malate but with no change in the contents of inorganic anions such as chloride, nitrate, and phosphate. These results suggest that protein phosphorylation is involved in the Al-responsive malate efflux in the wheat root apex and that the organic anion-specific channel might be a terminal target that responds to Al signaling mediated by phosphorylation.

Prevention of surgical site infection by antibiotic spraying in the operative field during cardiac surgery

OBJECTIVE

Despite the many procedures introduced to prevent surgical site infection during cardiothoracic surgery, serious infections still occur. We attempted to reduce surgical site infection by spraying antibiotic solution in the operative field--a procedure since introduced at 4 other Japanese institutions.

METHODS

In the latter half of 1990, we began spraying an antibiotic solution of cefazolin (1g) and gentamicin (40 mg)/40 ml of saline placed in a 50 ml syringe and dispensed through an 18 G needle bent at 60 to 80 degrees to clean the wound during surgery.

RESULT

No deep surgical site infections or deaths due to infection have occurred among the 502 patients undergoing cardiothoracic surgery under cardiopulmonary bypass at our hospital. This method was used in over 2,100 cases of similar procedures at 4 other institutions. There were 3 deaths due to severe surgical site infection (0.11%). At one institution treating over 1,000 cases a year, the incidence of death due to surgical site infection decreased significantly after this method was introduced.

CONCLUSION

These preliminary experiences show that spraying antibiotic solution in the operative field reduces the risk of surgical site infection in cardiothoracic surgery.

Immediate and long-term results of coronary artery bypass operation in hemodialysis patients

This study evaluated the early and late results of coronary artery bypass grafting (CABG) in patients on long-term maintenance hemodialysis (chronic HD) at Teikyo University Ichihara Hospital between January 1996 and June 2000. Thirty-six patients on chronic HD underwent CABG. There were 26 males (72%) and 10 females (28%) ranging from 41 to 81 years (mean +/- SD, 61.8 +/- 9.2 years) of age. Twenty-one patients (58%) had unstable angina, 14 (39%) stable angina, and 1 acute myocardial infarction. Eleven patients (31%) had urgent or emergency CABG. The average graft number was 2.5 +/- 0.8 (arterial graft 1.3 +/- 0.7/patient). Six patients had concomitant cardiac operations. Three patients underwent re- or a second re-CABG. Five patients underwent off-pump CABG. Principally, HD was performed during cardiopulmonary bypass and was followed by continuous hemodiafiltration in the early postoperative period. The early mortality was 11%; 25% in emergency and urgent CABG and 4% in elective CABG. In the follow-up period between 1 and 53 months (mean +/- SD 21.9 +/- 15.1 months), 4 patients died, and 9 patients developed recurrence of angina pectoris (6, occlusion of saphenous vein graft and 3, native coronary progression). Six patients had coronary intervention. The postoperative angiogram showed that all arterial grafts were patent, but the patency of the vein grafts was only 61.5%. The early results of CABG in patients on chronic HD was satisfactory. The late recurrence of angina pectoris mostly was caused by occlusion of the saphenous vein graft. In conclusion, the aggressive use of arterial grafts is crucial in CABG for patients on chronic HD.

Identification of novel C253Y missense and Y864X nonsense mutations in the insulin receptor gene in type A insulin-resistant patients

Mutations in the insulin receptor gene have been reported in cases of type A insulin resistance. We report herein two cases of type A insulin resistance, which involve some novel mutations. Case 1 is a heterozygote of the C253Y missense mutation and case 2 is a heterozygote of the Y864X nonsense mutation. In the C253Y missense mutation in exon 3, a cysteine residue is replaced with tyrosine in the cysteine-rich domain of the alpha subunit. The Y864X in exon 13 results in a truncated receptor, which is devoid of most of the beta subunit. This mutant receptor could not be expressed on a cell membrane since the transmembrane domain is missing. Other significant mutations were not found for the entire coding regions and splice/donor sites.

Native valve salvage for post-traumatic tricuspid regurgitation

We describe two cases of successful management by native valve salvage of an uncommon tricuspid valve regurgitation following blunt chest trauma. The two patients were diagnosed 13 years and six years, respectively, after the trauma. In both cases, tricuspid valvular insufficiency was caused by anterior leaflet prolapse due to chordal and papillary muscle rupture associated with annular dilatation. Operative repair with implantation of artificial chordae, papillary muscle reinsertion and ring annuloplasty resulted in complete recovery. The need for increased awareness of this lesion in patients suffering blunt chest trauma is emphasized, and the relevant literature reviewed.

[Long-term survival of a patient with postoperative liver metastasis of stage IVa gallbladder cancer responding to hepatic arterial infusion chemotherapy]

A 58-year-old man was diagnosed as having advanced gallbladder cancer (T4, P0, H0, N0, stage IVa) with direct invasion to the liver, transverse colon and duodenum. Therefore, extended cholecystectomy and bile duct resection with a partial resection of the transverse colon and the duodenum were performed in March 1992. Histopathological examination revealed moderately differentiated tubular adenocarcinoma of si, ly1, v1, hinf3, binf3, n0. Three years and eight months after the operation, multiple liver metastases were diagnosed by abdominal CT. Repeated hepatic arterial infusion chemotherapy with 5-FU 500 mg/body/w, MMC 4 mg/body/2w and EPI 40 mg/body/4w was performed starting in January 1996. Four months later, the lesions in the liver were reduced in size, and abdominal CT 10 months after the chemotherapy showed a partial response. However, the liver metastasis of the right lobe was enlarged on an abdominal CT in August 1997. Repeated hepatic arterial infusion chemotherapy with the same regimen was performed again starting in March 1998. Ten months later, the liver metastasis was slightly enlarged, but the greater part of the metastasis showed necrosis on an abdominal CT in January 1999. However, peritonitis carcinomatosa was observed later and the patient died 8 years after the operation.

[Clinical significance of serum LpA-I levels measured by immunoturbidimetric assay in type 2 diabetes mellitus patients]

Previously, we developed an immunoturbidimetric assay method for lipoprotein A-I(LpA-I) on sera pre-absorbed with anti-apolipoprotein A-II. In the present study, correlations between serum lipoprotein A-I and other serum parameters levels were examined and LpA-I levels were studied in patients with type 2 diabetes mellitus. The serum levels of LpA-I did not correlate with those of diabetic markers such as fasted blood glucose, glycohemoglobin(HbA1c) and fructosamine, but correlated well with the levels of total cholesterol and HDL cholesterol, phospholipids, apolipoprotein A-I and seemed to correlate inversely with arteriosclerosis index. In patients with type 2 diabetes mellitus, LpA-I levels were significantly lower than those in normal subjects. Especially, LpA-I levels of patients with diabetic complications were significantly lower than those in normal subjects and non-complicated diabetic patients. Then, the measurement of LpA-I levels in patients with type 2 diabetes mellitus was considered to be useful for prevention and management of arteriosclerosis.

Comparative analysis of colonization of Helicobacter pylori and glycolipids receptor density in Mongolian gerbils and mice

The Mongolian gerbil has been used as an excellent experimental animal model for studying Helicobacter pylori infection because it can stably colonize and induce severe chronic gastritis, ulceration, and cancer-simulating human diseases in this animal. In contrast, H. pylori can only induce mild inflammation in many mouse models. The aim in this study is to clarify the difference of induction of pathological lesions in the two animal models. SPF ICR mice and Mongolian gerbils were inoculated with a clinically isolated strain of H. pylori. Six weeks after inoculation, bacteria colonizing the stomach were counted. Immunohistochemical staining and biochemical analyses of three putative receptor glycolipids were performed with monoclonal antibodies to the respective glycolipids. Significantly higher numbers of H. pylori were recovered from the stomachs of Mongolian gerbils than mice (5.77 +/- 0.46 log CFU vs 4.17 +/- 0.55 log CFU, P < 0.01). Immunohistochemical studies showed that sulfatide expression in the gastric mucosa of Mongolian gerbils was much stronger than that in mice, whereas the expression of Lewis(b) glycolipid and GM3 were almost equal. Quantitative analysis of each glycolipid by thin-layer chromatography confirmed the results of immunohistochemical study, showing 4.1 times higher sulfatide content in the Mongolian gerbil stomach. The content of both Lewis(b) and GM3 was almost equivalent in these two animals. In conclusions, higher levels of sulfatide expression, a putative adhesion receptor, in the gastric mucosa of Mongolian gerbils may allow abundant colonization by H. pylori, resulting in the development of gastric lesions in this animal model.

[Surgical removal of left atrial tumor originating from mitral annular calcification in a chronic hemodialysis patient: a case report]

A 66-year-old female with a 3-year history hemodialysis suffered from cerebral infarction and revealed a tumor of left atrium by echocardiography at another hospital. She was referred to our hospital for surgery of left atrial tumor. The tumor was a round dense echogenic mass at the annular position of the posterior mitral leaflet by echocardiography. Surgical removal of the tumor was carried out because the lesion produced embolization. Histological examination revealed the tumor to be calcifications.

C-Type natriuretic peptide inhibits proliferation and monocyte chemoattractant protein-1 secretion in cultured human mesangial cells

BACKGROUND

Mesangial cell proliferation and matrix accumulation are hallmarks of various progressive glomerular diseases. We examined whether C-type natriuretic peptide (CNP) that is known to regulate the proliferation of vascular smooth muscle cells could modulate these pathological processes using human glomerular mesangial cells (GMCs) in culture.

METHODS

Proliferation of GMCs cultured with different concentrations of CNP-22 for 48 h was determined by a colorimetric assay using a tetrazolium salt. Monocyte chemoattractant protein-1 (MCP-1) and type IV collagen secretion into the culture media by GMCs in the presence or absence of CNP-22 were evaluated by ELISA. Expression of mRNA for natriuretic peptide receptor B (NPR-B), a specific receptor for CNP, was examined by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

CNP-22 (1-10 microM) inhibited serum-induced GMC growth in a dose-dependent manner. The amount of MCP-1 in the culture supernatant was increased approximately 2.4-fold by 5 microg/ml of lipopolysaccharide. This increase was inhibited by CNP-22 at 0.1-1 microM in a dose-dependent fashion. CNP-22 (10 microM) inhibited GMC type IV collagen secretion stimulated by 20 ng/ml of platelet-derived growth factor. Expression of NPR-B mRNA was confirmed in GMCs by RT-PCR.

CONCLUSIONS

CNP suppresses GMC proliferation and MCP-1 and type IV collagen secretion by GMCs. It may have a therapeutic potential against human proliferative glomerular diseases, especially those with the involvement of monocytes.

Aluminum-induced 1-->3-beta-D-glucan inhibits cell-to-cell trafficking of molecules through plasmodesmata. A new mechanism of aluminum toxicity in plants

Symplastic intercellular transport in plants is achieved by plasmodesmata (PD). These cytoplasmic channels are well known to interconnect plant cells to facilitate intercellular movement of water, nutrients, and signaling molecules including hormones. However, it is not known whether Al may affect this cell-to-cell transport process, which is a critical feature for roots as organs of nutrient/water uptake. We have microinjected the dye lucifer yellow carbohydrazide into peripheral root cells of an Al-sensitive wheat (Triticum aestivum cv Scout 66) either before or after Al treatment and followed the cell-to-cell dye-coupling through PD. Here we show that the Al-induced root growth inhibition is closely associated with the Al-induced blockage of cell-to-cell dye coupling. Immunofluorescence combined with immuno-electron microscopic techniques using monoclonal antibodies against 1-->3-beta-D-glucan (callose) revealed circumstantial evidence that Al-induced callose deposition at PD may responsible for this blockage of symplastic transport. Use of 2-deoxy-D-glucose, a callose synthesis inhibitor, allowed us to demonstrate that a reduction in callose particles correlated well with the improved dye-coupling and reduced root growth inhibition. While assessing the tissue specificity of this Al effect, comparable responses were obtained from the dye-coupling pattern in tobacco (Nicotiana tabacum) mesophyll cells. Analyses of the Al-induced expression of PD-associated proteins, such as calreticulin and unconventional myosin VIII, showed enhanced fluorescence and co-localizations with callose deposits. These results suggest that Al-signal mediated localized alterations to calcium homeostasis may drive callose formation and PD closure. Our data demonstrate that extracellular Al-induced callose deposition at PD could effectively block symplastic transport and communication in higher plants.

Mutation analysis of transforming growth factor beta type II receptor, Smad2, Smad3 and Smad4 in esophageal squamous cell carcinoma

Mutations of the transforming growth factor beta type II receptor (TGFbetaRII) gene and Smad family genes have been observed in several human cancers. However, there has been no report on mutation analysis of the entire coding regions of these genes in esophageal cancer, and the role of these genes in the development of esophageal cancer remains unknown. We performed polymerase chain reaction-single strand conformation polymorphism analysis of TGFbetaRII, Smad2, Smad3 and Smad4 genes and microsatellite assay in 20 esophageal squamous cell carcinomas (ESCC). We detected polymorphisms at exon 2 of Smad3 and intron 6 of Smad4. No mutation was found in TGFbetaRII, Smad2, Smad3 and Smad4 genes. These results suggest that mutation of TGFbetaRII, Smad2, Smad3 and Smad4 genes is a rare event in ESCC.

[Whole-body oxygen consumption at different temperatures during cardiopulmonary bypass]

For evaluation of the adequacy of tissue perfusion during cardiopulmonary bypass (CPB), whole-body oxygen consumption rates at different body weights and temperatures are basic and important data. But few studies have analyzed the oxygen consumption estimated from real-time data during CPB in clinical situations. We analyzed retrospectively the oxygen consumption at different body weights (BW) during normothermia (VO2 37) and the oxygen consumption ratio at different body temperatures (BT; %VO2X; X = BT) from the CPB charts of 189 cases. From these charts, 877 data points for oxygen consumption during total CPB were calculated by Fick's law. By statistical analysis of these data, we derived the following formulae: VO2 37 (ml/kg/min) = 7.6481 x BW0.0679, R2 = 1.0 (BW < 8 kg) VO2 37 (ml/kg/min) = 32.394 x BW-0.625, R2 = 0.92 (BW > or = 8 kg) %VO2X (%) = 4 x 10(-5) x BT4.0777, R2 = 0.42. These formulae indicate that (1) the whole-body oxygen consumption during total CPB can be measured by subtracting the oxygen consumption associated with circulatory and respiratory processes from the oxygen consumption derived from the basal metabolism; and (2) although the change in oxygen consumption induced by hypothermia is variable depending on body weight, the rate of change shows no difference regardless of the patient's weight.

Partial left ventriculectomy in a 3-year-old boy with dilated cardiomyopathy

A 3-year-old boy suffered severe heart failure 2 months after ventricular septal defect repair. The cardiothoracic ratio was 67% and the ejection fraction 13%. Echocardiography showed a dilated left ventricle and thin myocardium. After thorough study, we made a diagnosis of dilated cardiomyopathy. Because conventional therapy was unsuccessful, we conducted partial left ventriculectomy with Alfieri repair of the mitral valve. The postoperative cardiothoracic ratio was 57% at 1 year of follow-up and the ejection fraction 40%. The New York Heart Association functional class improved from IV to I. In conclusion, the role of partial left ventriculectomy is both as a bridge to transplantation and as a definitive repair in dilated cardiomyopathy during childhood.

[The role of daunorubicin in induction therapy for adult acute myeloid leukemia]

The relationship between the total dose of daunorubicin (DNR) in induction therapy and the treatment outcome were evaluated based upon individualized doses of DNR during induction therapy for patients with acute myeloid leukemia(AML). Ninety-two previously untreated adult AML patients admitted to our hospital were analyzed for the dose of DNR required for complete remission (CR), the CR rate, disease-free survival (DFS) and overall survival (OS). The induction therapy consisted of DNR (40 mg/m2/d, i.v., from D 1 until the marrow was hypoplastic), Ara-C, prednisolone, and/or 6-thioguanine. Eighty-three out of 92 patients were assessable. Sixty-three patients entered CR (76%), of whom 52 attained CR with the first course of induction therapy. The 10-year DFS and OS rates were 31.2% and 42.3%, respectively. The median total dose of DNR in the induction therapy was 280 mg/m2 (120-480 mg/m2), which was not influenced by initial WBC count, or FAB type. These results indicate that when the dose is linked to the observed tumor response, the optimal dose of DNR in the induction therapy is around 280 mg/m2 (40 mg/m2 x 7 times), which is higher than the conventional dose of 40-60 mg/m2 for 3 days. The higher dose of DNR in the induction therapy for adult AML should be selected when the feasibility of a new drug is evaluated in a randomized trial.

Transducin-like enhancer of split proteins, the human homologs of Drosophila groucho, interact with hepatic nuclear factor 3beta

Members of the hepatic nuclear factor 3 (HNF3) family, including HNF3alpha, HNF3beta, and HNF3gamma, play important roles in embryonic development, the establishment of tissue-specific gene expression, and the regulation of gene expression in differentiated tissues. We found, using the glutathione S-transferase pull-down method, that the transducin-like Enhancer of split (TLE) proteins, which are the human homologs of Drosophila Groucho, directly associate with HNF3beta. Conserved region II of HNF3beta (amino acids 361-388) is responsible for the interaction with TLE1. A mammalian two-hybrid assay was used to confirm that this interaction occurs in vivo. Overexpression of TLE1 in HepG2 and HeLa cells decreases transactivation mediated through the C-terminal domain of HNF3beta, and Grg5, a naturally occurring dominant negative form of Groucho/TLE, also increases the transcriptional activity of this region of HNF3. These results lead us to suggest that TLE proteins could influence the expression of mammalian genes regulated by HNF3.

Aneurysms in the ascending aorta adherent to the sternum after cardiac surgery

Sternotomy in a patient with an aneurysm in the ascending aorta adherent to the sternum after cardiac surgery can result in fatal hemorrhage or brain damage unless the distal ascending aorta can be identified and secured immediately. A left anterolateral thoracotomy was used in three patients with adherent aneurysms. The distal ascending aorta was isolated, and dissection was performed between the aneurysm and the sternum. There was no complication. This method was safe, and blood loss was minimized.

Platelet-derived growth factor, basic fibroblast growth factor, and interferon gamma increase type IV collagen production in human fetal mesangial cells via a transforming growth factor-beta-dependent mechanism

BACKGROUND

Glomerulosclerosis is characterized by glomerular accumulation of extracellular matrix following mesangial cell proliferation. The precise pathomechanism of glomerulosclerosis is still undetermined. Platelet-derived growth factor (PDGF) and basic fibroblast growth factor (b-FGF) are known to be mitogenic for mesangial cells, and interferon gamma (IFN-gamma) is known to have an inhibitory effect on mesangial cell proliferation. We attempted to clarify the role of these cytokines on mesangial matrix production using cultured human fetal mesangial cells (HMC).

METHODS

HMC were incubated with these cytokines for 24-72 h and the levels of type IV collagen and TGF-beta in the cell supernatants were measured by enzyme immunoassay.

RESULTS

PDGF, b-FGF, and IFN-gamma stimulated type IV collagen production by HMC in a dose- and time-dependent manner. The anti-TGF-beta neutralizing antibody clearly inhibited their stimulatory effect on type IV collagen production. PDGF and b-FGF also stimulated TGF-beta production by HMC in a dose-dependent manner, although IFN-gamma did not.

CONCLUSION

PDGF, b-FGF, and IFN-gamma stimulate type IV collagen production in cultured HMC via a TGF-beta-dependent mechanism.

Identification of Gaucher cells in the chorionic villi associated with recurrent hydrops fetalis

Recurrent non-immune hydrops fetalis has rarely been reported. In order to detect the risk of recurrence in a subsequent pregnancy, one should carefully consider the possibility of an inborn error of metabolism. In such cases, placental examination may be useful in detecting such metabolic storage disorders in the fetus, which usually present as vacuolization of placental cells. We describe a rare case of recurrent hydrops that was detected by placental examination. Through light microscopy, electron microscope (EM) studies and beta-glucocerebrosidase activity the disease was identified as Gaucher's disease.

A complete deficiency of coagulation factor XIII A-subunit due to a novel compound heterozygote of Ser 413 Leu missense and an nt 389 (ins G) frameshift mutation

Coagulation factor XIII consists of two A- and two B-subunits, and either gene mutation can cause a complete deficiency. In a newborn patient with persistent bleeding from the umbilical cord stump, the plasma A-subunit protein was not detectable. Direct PCR sequencing revealed an nt 389 (ins G) frameshift mutation in exon 4 resulting in a new stop codon and a Ser 413 Leu missense mutation in exon 10 in either allele. His mother and father were heterozygous for the nt 389 (ins G) and the Ser 413 Leu, respectively, with about 50% reduction of the plasma A-subunit proteins. In all family members examined only those with either mutation showed the reduced subunit A protein levels. Thus, this complete deficiency of factor XIII was due to a novel compound heterozygous mutation in the A-subunit gene.

Comparison of clinical results between GDC treatment and direct surgery for ruptured cerebral aneurysms

We present a comparison of clinical results between GDC treatment and direct surgery for ruptured cerebral aneurysms. From May 97 to April 98, 32 aneurysms were treated by direct surgery (DS) or GDC treatment. Treatments were selected depending on the clinical grade, degree of hematoma and anatomical aspect of the aneurysms. There were 13 GDC treated cases and 19 direct surgery cases. In GDC cases, there were acute stage embolization for ruptured basilar aneurysm, recurrence of case after clipping for BA-SCA aneurysm, advanced age cases, and systemic complication cases. Glasgow outcome scale (GOS) in GDC cases were 8 GR, 2 MD and 3 SD. GOS in direct surgery cases were 7 GR, 4 MD, 4 SD and 4 deaths. Cases of severe subarachnoid hemorrhage with hematoma influenced the high death rate in direct surgery group. There were three complications associated with the procedure in the GDC group, however, the rate improved after advancement of the procedure. In conclusion, GDC treatment for ruptured cerebral aneurysm was satisfactorily acceptable compared to the results of direct surgery, however, more cases will be needed for precise comparison.

[Surgical treatment of 2 cases of irradiation induced constrictive pericarditis]

<Case 1> A 72-years-old man underwent radiation therapy (62 Gy) for esophageal carcinoma. Twelve months later, symptoms of heart failure such as syncope, cough and hepatomegaly manifested. On catheter study, a dip and plateau pattern of right ventricular pressure curve was evident. Pericardiectomy without extracorporeal circulation was performed. Operative findings and pathological results were compatible with radiation-induced constrictive pericarditis. He recovered from the heart failure, and has been doing well 3 months after the surgery. <Case 2> A 54-years-old man underwent thymectomy for malignant thymoma. He underwent a radiation therapy (52 Gy) postoperatively. After 12 months from the irradiation, syncope and dyspnea manifested. On catheter study, a dip and plateau pattern of right ventricular pressure curve was observed. Pericardiectomy with extracorporeal circulation was performed. He recovered from the heart failure after pericardiectomy, however he died of radiation-induced pneumonitis 6 months later.