Alternative RNA splicing of the human endothelin-A receptor generates multiple transcripts

In order to elucidate the regulatory mechanisms of expression of the human endothelin-A receptor (hET-AR) gene, we characterized hET-AR transcripts using reverse transcriptase (RT)-PCR analysis in a variety of human tissues. RT-PCR of lung mRNA using a set of primers from exons 2 and 5 showed two lower-molecular-mass transcripts in addition to the expected fragment. When RT-PCR with primers from exons 4 and 8 was performed, no transcripts other than the expected one were detected. PCR cloning utilizing a set of primers from exons 2 and 8 which covered the entire coding sequence revealed that the cDNA clones corresponding to the two novel transcripts contained deletions of 199 bp and 327 bp respectively compared with the previously described hET-AR cDNA. Comparison of their sequences with that of the hET-AR gene showed that the deleted sequences correspond exactly to exon 4 and exons 3 and 4 respectively, indicating that these lower-molecular-mass ET-AR transcripts results from alternative RNA splicing (designated ET-AR delta 4 and ET-AR delta 3,4 respectively). Alternative splicing of exon 4 results in a transcript which would be translated into a C-terminal truncated protein containing the first, second and third transmembrane domains, while the splicing out of exons 3 and 4 would produce a protein with five membrane-spanning domains but lacking the third and fourth domains present in the ET-AR protein. An RNase protection assay revealed that ET-AR delta 4 and ET-AR delta 3,4 as well as ET-AR, transcripts were observed in various human tissues, including the lung, aorta, atrium, kidney and placenta, which are known to express ET-AR abundantly. Thus we have isolated the cDNAs of novel transcripts of hET-AR which are generated by alternative RNA splicing, and these results suggest that this alternative RNA splicing might contribute to the regulation of ET-AR gene expression.

Pericardial mesothelioma presenting as left atrial thrombus in a patient with mitral stenosis

Primary pericardial mesothelioma is rare and remains a diagnostic and therapeutic challenge. Pericardial mesothelioma usually occurs independently of intracardiac lesions and infiltrates adjacent tissues superficially. An extremely rare case of malignant pericardial mesothelioma complicated by prior mitral valve surgery is reported. The tumour invaded the left atrium and mimicked a thrombus.

[Clinicopathological study on primary lung cancer--immunohistochemical expression of p53 suppressor gene and bcl-2 oncogene in relation to prognosis]

Two hundred and eleven surgically resected primary lung tumors were studied immunohistochemically. According to histologic type, they were 129 adenocarcinomas, 56 squamous cell carcinomas, 4 small cell carcinomas, 8 large cell carcinomas, 8 adenosquamous cell carcinomas, 5 so-called carcinosarcomas and 2 other tumors. Immunohistochemical expression of p53 and bcl-2 was studied in relation to the disease-free survival. Among the 211 patients with lung cancer, 109 were positive for p53 expression, and there was no significant relationship between p53 expression and sex, or clinicopathological stage and size of the tumor, although the patients with squamous cell carcinoma had a significantly higher frequency of p53 expression than those with adenocarcinomas. The frequency of p53 expression was significantly higher in the patients with poorly differentiated adenocarcinomas than in those with other histologic types. Seventy four of the 211 patients were positive for bcl-2 expression and bcl-2 expression was higher in the stage I patients and patients with small lung tumors 2cm or less in diameter than in the other patients. The patients with adenocarcinoma had a higher frequency of expression than those with squamous cell carcinoma but no difference was found in the histological differentiation of the tumor. The 5-year survival of patients positive for p53 expression was poorer than that of those with negative expression and the survival rate was higher in the patients positive for bcl-2 expression than in those with negative expression. These findings suggested that the expression of p53 and bcl-2 is a useful marker of follow-up and prognosis, but will require more data concerning the mechanism of carcinogenesis. Seven cases of primary lung cancer were examined for genetic abnormality of the p53 gene. cDNA was synthesized from total RNA of primary tissues of lung cancer using oligo (dT) primer and reverse transcriptase and polymerase chain reaction (RT-PCR), and PCR-single strand conformation polymorphism (SSCP) analysis were performed. Five patients gave a positive result upon PCR-SSCP analysis of the p53 gene. To confirm the results of PCR-SSCP analysis, their nucleotide sequences were further analyzed and four of them had point mutations at different codons (154, 176, 207, 236) and one had deletion of one nucleotide (245) in exon 5 and 8. Fifteen percent of 26 patients with small peripheral lung adenocarcinomas less than 2cm in diameter were already advanced in stage and various factors such as vascular invasion, pleural involvement and degree of scar grade were higher than in patients with clinicopathological stage I. In advanced cases, the frequencies of p53 expression was higher than in stage I cases. Concerning the relationship of the degree of scar grade to PDGF-B expression, we demonstrated the production of PDGF-B protein immunohistochemically and the expression of PDGF-B-mRNA by In situ hybridization in the adenocarcinoma cells and macrophages of the lung tumors. However, no significant correlation was observed between the degree of PDGF-B expression and collagen production in the fibrotic focus.

Airway basophil and mast cell density in patients with bronchial asthma: relationship to bronchial hyperresponsiveness

We investigated the role of basophils and mast cells in the pathogenesis of bronchial asthma. Eight asthmatics (6 atopic, 2 nonatopic) and 6 control subjects were enrolled in this study. Bronchial responsiveness to acetylcholine (PC20ACh) was measured in asthmatics and endobronchial biopsy from right upper lobe bronchus was performed on the same day. Basophils and mast cells in the airways were identified by immunohistochemistry using a monoclonal antibody against tryptase and anti-IgE. The number of basophils of asthmatics was 52.2 +/- 12.5/mm(2). In contrast, no basophils were found in the airways of control subjects. There was a significant increase of number of mast cells in the asthma group compared to the control group (168.6 +/- 32.6 vs. 22.3 +/- 6.1, p<0.01). There was an inverse correlation between airway basophil and mast cell numbers and PC20ACh (r=-0.82, r=0.72, p<0.05). These findings suggest a possible role for basophils and mast cells in the pathophysiology of asthma.

Clinical implication of the integration patterns of human T-cell lymphotropic virus type I proviral DNA in adult T-cell leukemia/lymphoma

In this review, we discuss the possible relationship between the clinical characteristics and the integration patterns of human T-cell lymphotropic virus type I (HTLV-I) proviral DNA in patients with adult T-cell leukemia/ lymphoma (ATL). Some ATL patients show unusual integration patterns such as multiple or defective HTLV-I and have clinical characteristics unlike those of most ATL patients who have the characteristic integration pattern of one complete provirus. Multiple HTLV-I integrations can be detected as two or more bands using the standard Southern blotting method when the tumor cellular DNA is digested with an endonuclease that does not cleave within the provirus. This includes cases of one tumor cell clone carrying two or more copies of the provirus, or alternatively two or more cell clones, each carrying one copy of the provirus. The former group of patients always manifest severe dyspnea and hypoxemia with unusual organ infiltrations including the retina and muscle and an extremely aggressive clinical course. On the other hand, the latter group of patients have an indolent course with skin lesions or small T lymphocytes with cleaved or lobulated nuclei. A solitary defective HTLV-I in some ATL patients can be detected as one smaller band after digestion of cellular DNA with an endonuclease that does not cleave within the provirus. These patients generally have a favourable clinical course with small cleaved or bilobulated T lymphocytes without lymphadenopathy or skin lesions. These findings suggest that there are clinical implications for the integration patterns of HTLV-I and this may be one of the explanations for the heterogeneous behaviour of the disease. Such studies may provide information on the relationship between virus integration and the clinical manifestations and also improve our understanding of the pathogenesis of ATL.

Augmented expression of the endothelin-A receptor gene in cultured mesangial cells from stroke-prone spontaneously hypertensive rats

1. To elucidate the role of endothelin (ET) receptor in hypertension, we studied the expression of the ET-A receptor (ET-AR) gene and the ET-B receptor (ET-BR) gene in cultured mesangial cells isolated from stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto (WKY) rats. 2. The mesangial cells from both SHRSP and WKY expressed ET-AR predominantly. The level of the ET-AR mRNA in mesangial cells from SHRSP was 5-fold higher than that in the cells from WKY. The ET-BR mRNA in the mesangial cells from both strains was hardly detectable by northern blot analysis. 3. These results demonstrate that the expression of the ET-AR gene was markedly augmented in mesangial cells from SHRSP.

Endothelin-induced activation of mitogen-activated protein kinases in glomerular mesangial cells from normotensive and stroke-prone spontaneously hypertensive rats

1. Kinase assay in myelin basic protein (MBP) containing polyacrylamide gels revealed that endothelin-1 (ET-1) and ET-3 increased MBP kinase activities in glomerular mesangial cells (MC) from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rat (SHRSP). ET-1 stimulated MBP kinase activities more potently than ET-3. 2. Immunoprecipitation with anti-41-kDa MAPK antiserum showed that the MBP kinases activated by ET-1 correspond to 43- and 41-kDa MAPK. 3. Since Phorbol 12-myristate 13-acetate, a direct activator of protein kinase C, also activated MAPK, protein kinase C was suggested to mediate ET-induced activation of MAPK. 4. These results suggest that MAPK may mediate the ET actions in glomerular mesangial cells from normotensive rats as well as spontaneously hypertensive rats. Since ET is produced by vascular endothelial cells of the kidney and glomerular mesangial cells, the ET signalling pathway may have some physiological and pathophysiological significance in vivo glomerulus.

A model analysis of asymmetrical response of pulmonary VO2 during incremental and decremental ramp exercise

The responses of gas exchange and ventilatory variables exhibit obvious asymmetry between the incremental and decremental phases of trapezoidal ramp exercise (29). Computer simulation was performed to explore the possible mechanisms producing this asymmetry of pulmonary O2 uptake (VO2) dynamics. The model consisted of three compartments (the lungs, the exercising muscles, and the other organs and tissues), which were perfused by respective regional circulations. Exercise was simulated by increasing the pulmonary blood flow (Q) and the muscle. VO2 in proportion to work rate. The dynamic responses of Q and the muscle VO2 were assumed to obey first-order linear kinetics. The ratio of blood flow in the muscle compartment to total cardiac output was assumed to increase linearly with work rate. Our simulation demonstrated that the muscle blood flow and mixed venous O2 content exhibited significant asymmetry between the incremental and decremental phases of exercise. The model suggested that the asymmetry of VO2 between incremental and decremental ramp exercise was dependent on the redistribution ratio of blood flow to the working muscles. The validity of the model was then evaluated by comparing the simulated results with experimental data obtained.

Regulation of vitamin D-responsive gene expression by fluorinated analogs of calcitriol in rat osteoblastic ROB-C26 cells

We compared the activation of vitamin D-responsive genes by 24,24-difluorocalcitriol [F2-1 alpha,25(OH)2D3] and 26,26,26,27,27,27-hexafluorocalcitriol [F6-1 alpha,25(OH)2D3] with that by calcitriol [1 alpha,25(OH)2D3] in rat osteoblastic ROB-C26 cells. F2-1 alpha,25(OH)2D3 and F6-1 alpha, 25(OH)2D3 were ten times more potent than 1 alpha,25(OH)2D3 in inducing the expression of 1 alpha, 25(OH)2D3-24-hydroxylase (24-OHase) mRNA 6 h after adding vitamin D compounds. The lower affinity of these two fluorinated analogs compared with that of 1 alpha,25(OH)2D3 for vitamin D binding protein in serum (serum DBP) seemed to be partly involved in their increased ability to activate the 24-OHase gene. A time course study revealed that the expression of the 24-OHase and osteopontin mRNAs in the cells incubated with 1 alpha, 25(OH)2D3 and F2-1 alpha,25(OH)2D3 attained maximal levels at 6 h for 24-OHase mRNA and 18 h for osteopontin mRNA, the both decreased thereafter. On the contrary, F6-1 alpha,25(OH)2D3 increased the expression of 24-OHase and osteopontin exponentially until 72 h. While F2-1 alpha,25(OH)2[1 beta-3H]D3 was catabolized quickly by ROB-C26 cells, F6-1 alpha,25(OH)2[1 beta-3H]D3 was slowly and quantitatively converted into putative 26,26,26,27,27,27-hexafluoro-23S-hydroxy[1 beta-3H]calcitriol (F6-1 alpha,23S,25(OH)3[1 beta-3H]D3). This may explain why the time-course profiles of the accumulation of mRNAs for 24-OHase and osteopontin differed in the cells exposed to the fluorinated analogs. In addition to the longer retention, unknown up-regulating mechanisms appeared to be involved in the exponential activation of the 24-OHase and osteopontin genes induced by F6-1 alpha,25(OH)2D3.

Cloning and sequencing of a gene encoding D-aminoacylase from Alcaligenes xylosoxydans subsp. xylosoxydans A-6 and expression of the gene in Escherichia coli

The gene encoding the D-aminoacylase of Alcaligenes xylosoxydans subsp. xylosoxydans A-6 (Alcaligenes A-6) was cloned and its complete nucleotide sequence was identified. The D-aminoacylase structural gene consists of 1452 nucleotides and encodes 484 amino acid residues. The molecular weight of D-aminoacylase was calculated to be 51,918. This value agreed well with the apparent molecular weight of 52,000 found for the purified enzyme from Alcaligenes A-6 by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE). The N-terminal amino acid sequence (NH2-SQSDSQPFDLLRAG-) predicted by the nucleotide sequence exactly matched those of the purified D-aminoacylase both from Alcaligenes A-6 and from cloned Escherichia coli (E. coli), with the exception of the removal of the N-terminal methionine processed after translation. The purified recombinant enzyme showed almost the same enzymatic properties as the native enzyme from Alcaligenes A-6. Alcaligenes A-6 D-aminoacylase showed 25-29% homology with L-aminoacylases from Bacillus stearothermophilus, porcine and humans.

Percutaneous left ventricular assist system using a modification of the Dennis method: initial clinical evaluation and results

A percutaneous left ventricular assist system (PLVAS) using a modification of the Dennis method was developed and implemented in 8 patients. Transseptal cannulation was performed under biplane fluoroscopy and/or transesophageal echocardiogram without encountering any problems. All the patients were in a state of severe cardiogenic shock, caused by acute myocardial infarction in 5, cardiomyopathy in 2, and postcardiotomy in 1, and were on intraaortic balloon pump support and/or percutaneous cardiopulmonary support (PCPS), in the form of partial cardiopulmonary bypass. Three patients who developed concomitant right heart failure required additional PCPS. All the patients were supported at 3.0 to 4.0 l/min for 76-284h for an average time of 159h. Three patients were successfully weaned from PLVAS and one of these patients, who had suffered an acute myocardial infarction, was discharged from hospital. The complications directly related to this system were minimal. Our observations led to the conclusion that PLVAS using our modification of the Dennis method is a simple, easy, and safe means of maintaining adequate systemic circulation in severely ill patients. As PLVAS is particularly effective for patients in cardiogenic shock following acute myocardial infarction, we believe that it will be applied routinely by many cardiac surgeons and cardiologists in the future.

Artificial cell-spreading of permeabilized BHK cells on fibronectin-coated substratum

We developed a cell-spreading model of permeabilized BHK cells to analyze molecular interactions in the cell-spreading machinery. BHK cells in suspension were allowed to attach onto the fibronectin-coated cover slips at 37 degrees C for 20 min. The cells were then permeabilized with 50 micrograms/ml saponin for 10 min at 4 degrees C. Approximately 50 percent of the cell models spread in response to exogenous 1 mM ATP for 90 min at 37 degrees C. Anti-actin antibody penetrated into almost all the cell models which spread ATP-dependently. These indicate that half number of the cell models permeabilized with saponin is spread by the exogenous ATP and has pores larger than an IgG molecule.

Safety and pharmacokinetics of iotrolan in hysterosalpingography. Retention and irritability compared with Lipiodol

RATIONALE AND OBJECTIVES

The authors compared the safety and pharmacokinetics of Iotrolan (water-soluble) in hysterosalpingography (HSG) with those of Lipiodol (oil-soluble).

METHODS

Iotrolan and Lipiodol were administered intraperitoneally at doses of 100 mg iodine/kg to female rabbits. Retention in the body was investigated by x-ray imaging, plasma kinetics, and urinary and fecal excretion. Irritability in the abdomen was investigated by histologic examination.

RESULTS

Iotrolan was entirely excreted into the urine within 2 days after administration. Conversely, Lipiodol was excreted into the urine, had a half-life of 50 days, and was retained for more than 21 days in the abdomen. Iotrolan induced no inflammatory reaction in the abdomen, whereas Lipiodol induced a marked abdominal inflammatory reaction, including granuloma formation. Iotrolan had no effect on iodine concentration in the thyroid; Lipiodol increased iodine concentration significantly.

CONCLUSIONS

Iotrolan, which is a water-soluble and nonionic dimeric contrast medium, has potential greater safety for use in HSG than Lipiodol.

In vivo transfection of hepatitis C virus complementary DNA into rodent liver by asialoglycoprotein receptor mediated gene delivery

An in vivo model of hepatitis C virus (HCV) infection is needed to enable investigation of the mechanism of the liver injury that it causes. In this study, we used asialoglycoprotein receptor mediated gene delivery to obtain expression of the complementary DNA (cDNA) coding the core and part of the envelope 1 protein of HCV because selective delivery to the hepatocytes has been reported to be attained with this method. The optimum carrier-DNA ratio was examined using in vitro transfection and found to be important for the efficiency of this method. In transfection in vivo, microautoradiographical examination showed that the transfected plasmids were delivered selectively to the liver parenchymal cells. To obtain an immunohistochemically detectable level of protein expression in rodent liver, some modifications for increasing the in vivo transfection efficiency were performed; a lysosomal enzyme inhibitor, chloroquine, was used and the administration route of the carrier-DNA complex was changed from the tail vein to the portal vein. On the bases of these results, in vivo transfection with expression vector of HCV core/E1 region was performed. In rat liver transfected by intraportal injection with chloroquine, the transcript RNA and the core protein were detected. These results indicated that the HCV core/E1 expression vector was not merely delivered but also successfully expressed in the liver using asialoglycoprotein receptor mediated gene delivery. The number of the HCV core expressing cells in the transfected liver was similar to that in patients with hepatitis C. These in vivo transfected animals should be useful for investigating the role of this region in the liver injury caused by HCV.

Serial changes in the prevalence of islet cell antibodies and islet cell antibody titer in children with IDDM of abrupt or slow onset

OBJECTIVE

To elucidate the significance of clinical and immunogenic heterogeneity in Japanese children with insulin-dependent diabetes mellitus (IDDM).

RESEARCH DESIGN AND METHODS

Serial changes in the prevalence of islet cell antibodies (ICAs) and in ICA titer were monitored for 10 years after diagnosis in 34 IDDM children, 17 with abrupt onset and 17 with slow onset, whose durations of disease were > 5 years.

RESULTS

In slow-onset IDDM children, enough beta-cell function was maintained in the early phase of the disease within 2 years after diagnosis. There was a high prevalence of ICAs in children with both forms of IDDM at the time of diagnosis (abrupt onset 94%; slow onset 82%). However, the decline in the frequency of ICAs in slow-onset IDDM seemed less marked than in abrupt-onset IDDM after a duration of > or = 1 year (47 vs. 82%, 1-3 years; 24 vs. 47%, 3-5 years; 24 vs. 47%, 5-7 years; 18 vs. 53%, 7-10 years, P < 0.05). In terms of changes in ICA titer, abrupt-onset IDDM children initially had high ICA levels of 160-320 Juvenile Diabetes Foundation units (JDF U), but these titers decreased rapidly after the 1st year. On the other hand, slow-onset IDDM children tended to continue to be ICA+ for a relatively long period with low titers of 20-40 JDF U. Among 12 children who remained ICA+ for > 5 years, slow onset was noted in 67% while abrupt onset was seen in only 33%.

CONCLUSIONS

From these results, we speculated that changes in ICA titer reflect the slow autoimmune destruction of pancreatic beta-cells. It may be probable that immunogenic factors as well as environmental factors could affect the clinical features in the early phase of IDDM in children.

Comparison between pulsatile and nonpulsatile circulatory assist for the recovery of shock liver

In patients with prior shock and liver injury, mechanical circulatory assist still has a high risk of hepatic failure. The purpose of this study was to evaluate the effect of mechanical circulation using pulsatile or nonpulsatile blood pumps on shock organs, particularly shock liver. In 14 dogs, a shock liver model was produced by clamping the descending aorta above the diaphragm. After 60 minutes of ischemia, left atrial-femoral artery bypass (LHB) was started while the clamp remained in place. A pneumatic pulsatile pump (Toyobo; Tokyo, Japan) was used in seven dogs (Gr-PP) and a centrifugal pump (Biomedicus; Minneapolis, MN) in seven (Gr-NPP). In both groups the mean arterial pressure was maintained at 80 mmHg. The mean bypass flow was 96 +/- 14 ml/kg/min for Gr-PP, and 95 +/- 35 ml/kg/min for Gr-NPP. In both groups the bile flow and arterial ketone body ratio decreased significantly after ischemia, and recovered to normal after 120 min of LHB. There was no significant difference between the two groups in this model. The other parameters (glutamic oxaloacetic transaminase [GOT], glutamic pyruvic transaminase, lactate dehydrogenase, mitochondrial GOT) were independent of the period of ischemia and reperfusion, and there was no difference between the two groups. In conclusion, these results suggest that nonpulsatile circulatory assist may not be disadvantageous for the circulatory support and recovery of liver function in the setting of shock liver.

Primary structure of N-acyl-D-glutamate amidohydrolase from Alcaligenes xylosoxydans subsp. xylosoxydans A-6

The gene coding the N-acyl-D-glutamate amidohydrolase of Alcaligenes xylosoxydans subsp. xylosoxydans A-6 (Alcaligenes A-6) was cloned and its complete DNA sequence was determined. The N-acyl-D-glutamate amidohydrolase structural gene consists of 1,464 nucleotides and encodes 488 amino acid residues. The molecular weight of the enzyme was calculated to be 51,490. This value is close to the apparent molecular weight of 59,000 determined for the purified enzyme from Alcaligenes A-6 by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE). The N-terminal amino acid sequence of the recombinant protein exactly matches the amino acid sequence derived from the DNA sequence and that determined from the Alcaligenes A-6 enzyme (NH2-MQEKLDLVIEGGWVIDGLGG). The deduced amino acid sequence of the cloned N-acyl-D-glutamate amidohydrolase showed high sequence homology with those of N-acyl-D-aspartate amidohydrolase (46%) and D-aminoacylase (47%) from Alcaligenes A-6. This fact strongly suggests that these three enzymes have evolved from a common ancestral gene.

In vivo setting behaviour of fast-setting calcium phosphate cement

The in vivo setting behaviour of fast-setting calcium phosphate cement (FSCPC) between femoral muscles of the rat was investigated to evaluate the possible value of FSCPC for medical and dental application. Conventional CPC (c-CPC) and FSCPC were implanted between femoral muscles, and various aspects of the setting behaviour such as setting time, mechanical strength and conversion ratio of cement into hydroxyapatite (HAP: Ca10(PO4)6(OH)2) were measured by the Vicat needle method, diametral tensile strength (DTS) measurement, and quantitative powder X-ray diffraction (XRD) analysis, respectively. The setting time of FSCPC in vivo was 5-7 min, in contrast to 48 min for c-CPC. As a result of its fast setting, set specimens of FSCPC showed higher mechanical strength from the initial stage than c-CPC. Higher DTS values were observed in FSCPC than c-CPC implanted after 24 h. Powder XRD analysis revealed faster conversion of FSCPC than c-CPC into HAP, which was responsible both for the faster setting and higher mechanical strength from the initial stage. We concluded, therefore, that FSCPC may be used for a wide range of clinical applications, i.e. fields where fast setting is required such as orthopaedic, plastic and reconstructive, and oral and maxillofacial surgery.

Clinical experience with long-term use of the Toyobo left ventricular assist system

The Toyobo-NCVC extracorporeal pneumatic left ventricular assist system (LVAS) was used in four patients with advanced dilated cardiomyopathy. The duration of support ranged from 46 to 390 days (mean, 206 days). In all patients, stable hemodynamics were achieved with 3.5-5.5 L/min flow rates. Two patients survived long term. One was transported to the United States by a chartered jet while on LVAS and successfully underwent heart transplantation after 119 days of support. The other is on LVAS and is doing well for 390 days. The remaining two patients died of multi-organ failure while their hemodynamics were quite stable under LVAS. In these two patients, severe hepatic failure had developed before LVAS implantation. Minor cerebral embolisms occurred in the two survivors, but neither of them experienced permanent neurologic deficits. In only the initial patient were major thrombi noted on the diaphragm of the pump; the thrombi required pump exchange four times during 119 days. In the patient supported for 390 days, a small tear in the diaphragm was observed after 209 days of support, and the pump was safely exchanged. It is suggested that the Toyobo LVAS can provide consistent and reliable performance for long-term use.

An autopsy case of B-cell lymphoma associated with macroglobulinemia (IgM-k)

While he was treated for macroglobulinemia showing symptoms, a 65-year-old man developed an enlargement of the left lateral cervical lymph node. Biopsy specimens of the cervical lymph node revealed large-cell non-Hodgkin's lymphoma. The lymphoma cells had rearrangement in the immunoglobulin heavy chain and kappa light chain genes. There was osteolysis involving right metatarsal bones. And, a tumor appeared on the upper hard palate in the terminal stage. Autopsy specimens showed infiltration of lymphoma cells into multiple organs. Production of monoclonal immunoglobulin M was detected only slightly and focally in the tumors. Plasmacytic differentiation as in Waldenström's macroglobulinemia was not seen in any organs except the tumor on the upper hard palate. From these findings, it is speculated that B-cell lymphoma might have developed in the course of macroglobulinemia.

Development of calcium phosphate based functional gradient bioceramics

A functional gradient bioceramic that can function gradually with respect to body tissue was studied by changing the composition of calcium phosphate gradually from the surface to the inside. Diamond powder was spread on the surface of compact hydroxyapatite (HA) powder and fired at 1280 degrees C under reduced pressure, followed by firing under atmospheric conditions. The sintered body thus prepared was dense and alpha-tricalcium phosphate (alpha-TCP: alpha-Ca3(PO4)2) was found on its surface. The content of alpha-TCP gradually decreased with increasing depth from the surface. In contrast, the content of HA increased with increasing depth from the surface. The gradient ratio of alpha-TCP and HA depends on the firing time for each condition, i.e. reduced or atmospheric pressure. The alpha-TCP formation was ascribed to the decomposition of HA due to the spontaneous combustion of diamond powder.