Effects of nucleic acid inhibitors on the development of Angiostrongylus costaricensis in vitro

Nucleic acid biosynthesis of Angiostrongylus costaricensis was examined with various inhibitors; aminopterin (inhibitor of purine and pyrimidine de novo biosynthetic pathways), 8-azaguanine (specific inhibitor of purine salvage pathway) and PALA (specific inhibitor of pyrimidine de novo biosynthetic pathway) were applied in in vitro culture developing from the third stage larvae to young adult in chemically defined medium. It was suggested that A. costaricensis possessed functional purine and pyrimidine de novo biosynthetic pathways and also that they could utilize exogenous sources of purines and pyrimidines by salvage pathways for their development.

Effects of concomitant usage of milrinone and catecholamine for weaning from cardiopulmonary bypass

To estimate the effectiveness of concomitant usage of milrinone and catecholamine for weaning from cardiopulmonary bypass (CPB), a clinical study was made, in elective coronary artery bypass grafting (CABG) cases. 24 consecutive patients underwent elective CABG in our institute. In all cases, moderate hypothermia and cardioplegic(St. Thomas solution) cardiac arrest were performed. In 12 cases, continuous intravenous 0.25 microgram/kg/min of milrinone, 3 micrograms/kg/min of dobutamine (DOB) and dopamine (DOA) as the initial doses, were used concomitantly as inotropic agents (Group-I). The same initial doses of catecholamine (DOB and DOA) as the Group-I were administered in another 12 patients (Group-II). When the pump flow of CPB decreased to a half, these drugs were administered in both groups. Hemodynamic data were measured before CPB, just after operation, 3, 6, 12, 24, 48, and 72 hours after operation. There were no significant differences in aortic and pulmonary artery pressure between both groups. However, cardiac index (CI) of the Group-I demonstrated significantly (p < 0.01) higher values than that of Group-II until 24 hours after surgery. Systemic vascular resistance index (SVRI) of the Group-I demonstrated significantly (p < 0.01) lower value than that of Group-II from 3 to 12 hours after operation. There were no significant differences in oxygen delivery (DO2) and oxygen consumption (VO2) between both groups. These results suggested that concomitant usage of milrinone and low dose catecholamine increased CI and decreased SVRI, and made weaning from CPB very easy, demonstrating excellent hemodynamics. This high potential phosphodiesterase inhibitor may be suitable for not only weaning from CPB but also post-cardiotomy cardiogenic shock.

Macroscopic aspects of cloth-covered Starr-Edwards prostheses at reoperation: what the precursory valve teaches us

BACKGROUND AND AIMS OF THE STUDY

Cloth-covered Starr-Edwards ball valves were the first choice in prosthetic substitution at the authors' institution between June 1968 and March 1977. This study investigated, retrospectively, macroscopic aspects of the prostheses at reoperation.

METHODS

Among 59 survivors who underwent isolated aortic or mitral valve replacement, 12 required reoperation for valve dysfunction (five aortic valve replacements, seven mitral valve replacements). Reoperation was necessitated by valvular endocarditis, paravalvular leak, hemolysis, thromboembolism, orifice stenosis attributable to pannus, and inappropriate sizing related to growth and thrombus. The mean time to reoperation was 11.7 +/- 6.2 years after initial surgery (range: 2 years 4 months to 21 years 8 months).

RESULTS

Marked cloth wear was observed in all aortic prostheses, but only slight wear in mitral valves. Pannus formation was observed around the orifice in both aortic and mitral prostheses, but strut cloth was not extensively covered by autologous tissue. In mitral valves, strut cloth was only slightly worn and less loose than that of the aortic valve. These changes notably affected prosthetic valve function, the most significant problem in mitral prostheses being thrombus (four of seven valves).

CONCLUSIONS

Pannus formation and thrombus caused by the reaction of the patient's tissues remain major problems in the use of artificial valves, and require further work for their improvement.

In vitro excess ammonia production in human myeloma cell lines

It is well known that cases with multiple myeloma reveal various clinical manifestations such as pancytopenia, hyperproteinemia, renal dysfunction, bone lesions, hypercalcemia and immunodeficiency. Recently, a few more clinical features associated with myeloma, such as salivary type hyperamylasemia and elevated serum C-reactive protein (CRP) concentration, have been reported. The elevation of CRP is thought to be related to interleukin-6 (IL-6) production by myeloma cells, because of identification of IL-6 as an autocrine and/or paracrine growth factor for myeloma cells. More recently, there have been several reports of cases with myeloma associated with hyperammonemia. This hyperammonemia is not considered to be due to liver dysfunction, because in most of these cases tests revealed normal hepatic function, and some cases showed different patterns of serum amino acid distribution than that associated with hepatic failure. However, there have been no apparent observations of ammonia production by myeloma cells. In this study, we used six human myeloma cell lines including KMS-18, which was recently established from a myeloma case associated with hyperammonemia. These lines were treated with MRA (mycoplasma removal agent) to observe ammonia production in vitro. They produced and released significantly higher levels of ammonia into culture medium than non-myeloma hematological cell lines or the HepG2 human hepatic carcinoma cell line. Although attempts to analyze the relative expression levels of the enzymes related to ammonia biosynthesis using the reverse transcriptase-polymerase chain reaction assay failed to detect any differences between these myeloma lines and other cell lines, in vitro excess ammonia production by the myeloma cells was confirmed and the relevance to clinical manifestations is discussed.

Left atrial myxoma with an atrial septal defect: a case report and review of the literature

We report a case of a 49 year-old Japanese woman with a left atrial myxoma complicated by an atrial septal defect diagnosed intraoperatively, which was classified as in secundum defect and was 28x110 mm in diameter. The tumor, which was attached by a pedicle to the posterior wall of the left atrium near the posterior commissure of the mitral valve, was removed together with a small portion of the left atrial wall. The postoperative course was uneventful. The pathologic findings were consistent with the diagnosis of myxoma. Since the defect was functionally canceled by the myxoma, the diagnosis of an atrial septal defect was not confirmed preoperatively even by color Doppler echocardiography and cardiac catheterization. Tumor embolization is one of the critical complications of myxoma. Fortunately, she didn't suffer from either systemic or pulmonary emboli. During surgery of myxoma with atrial septal defect, careful manipulation is needed, especially at caval cannulation so as not to damage the tumor directly. In the cases with atrial septal defect or patent foramen ovale, myxomas are generally situated on the interatrial septum. However, in this case the tumor was located on the posterior wall of the left atrium.

Clinical experiences of percutaneous cardiopulmonary support: its effectiveness and limit

In recent years, several types of centrifugal pumps have been widely used as the main pumps for cardiopulmonary bypass (CPB) and postcardiotomy cardiac support. From April 1990 to March 1997, a percutaneous cardiopulmonary support (PCPS) system was used in 20 patients with an average age of 58 years (13 males and 7 females). They comprised 11 ischemic, 6 valvular, 2 aortic, and 1 congenital heart disease patients. Our PCPS system consists of a centrifugal pump (BioMedicus BP-80), an oxygenator, and a reservoir. The entire blood contacting surface, including that of the thin wall cannulas, is coated by heparin bonded materials. As a result of this new technology, this system can be used for the long term without systemic heparinization. No major critical thrombi were revealed inside the pumps or circuits. Of the 20 patients, 7 (35%) (Group 1) could be weaned from PCPS, and the remaining 13 (Group 2) could not. In Group 1 although 2 patients suffered from renal failure and pneumonia, respectively, both were discharged from our hospital. The long-term survival rate was 35%. In Group 2 cerebral vascular damage was recognized in 3 patients, renal failure in 4, multiple system organ failure in 4, bleeding in 2, arrhythmia in 1, and leg ischemia in 2. Pulse pressure was significantly elevated due to the recovery of the native heart in Group 1, 2 days after support. However, in Group 2, it did not elevate, and the left ventricular ejection fraction was less than 30%, associated with high left atrial pressure. In conclusion, this heparin coated PCPS system was very simple and easy to control. It demonstrated long-term biocompatibility and was very effective in recovering deteriorated cardiac function. Quicker application of this system can play an important role in preventing severe complications and obtaining better clinical results. If long-term support is necessary, a ventricular assist device (VAD), which is more powerful, durable, and biocompatible, has to be applied instead of PCPS.

One-stage repair of interrupted aortic arch and aortopulmonary window

Interrupted aortic arch type A with aortopulmonary window was diagnosed in a 12-day-old neonate. A successful one-stage repair was undertaken through a midline sternotomy without circulatory arrest. The aortopulmonary window was closed through the anterior wall of communication between ascending aorta and main pulmonary artery with a patch. Position of the arterial cannula was changed during the repair, which made it possible to mobilize and expose the aortic arch for the completion of direct anastomosis.

Dhh1p, a putative RNA helicase, associates with the general transcription factors Pop2p and Ccr4p from Saccharomyces cerevisiae

The POP2 (Caf1) protein in Saccharomyces cerevisiae affects a variety of transcriptional processes and is a component of the Ccr4p complex. We have isolated five multicopy suppressor genes of a pop2 deletion mutation: CCR4, DHH1 (a putative RNA helicase), PKC1, STM1, and MPT5 (multicopy suppressor of pop two). Overexpression of either the CCR4 or DHH1 genes effectively suppressed phenotypes associated with pop2 mutant cells; overexpression of PKC1, STM1, or MPT5 genes produced only partial suppression. Disruption of the CCR4 or DHH1 genes resulted in phenotypes similar to those observed for pop2 cells. In addition, overexpression of the DHH1 gene also suppressed the ccr4 mutation, suggesting a close relationship between the POP2, CCR4, and DHH1 genes. Two-hybrid analysis and coimmunoprecipitation experiments revealed that Pop2p and Dhh1p interact physically, and these and other data suggest that Dhh1p is also a component of the Ccr4p complex. Finally, we investigated the genetic interaction between factors associated with POP2 and the PKC1 pathway. The temperature-sensitive growth defect of dhh1 or mpt5 cells was suppressed by overexpression of PKC1, and the defect of mpk1 cells was suppressed by overexpression of MPT5. These results and phenotypic analysis of double mutants from the POP2 and PKC1 pathways suggested that the POP2 and the PKC1 pathways are independent but have some overlapping functions.

Multiple myeloma associated with serum amino acid disturbance and high output cardiac failure

We experienced a plasma cell leukemia (PCL) patient complicated with high output cardiac failure (HOCF), proved as his elevated cardiac index and pulmonary artery wedge pressure and decreased systemic vascular resistance index in a hemodynamic study. We found no possible causes of HOCF. Interestingly, HOCF was improved as PCL responded to intensive chemotherapy. On the other hand, he showed consciousness disturbance, and had frequent attacks of generalized seizure. His electroencephalogram showed slow waves, and a spike and wave complex. Hyperammonemia and abnormal amino acid distribution were also found. This abnormal serum amino acid distribution, especially elevated glycine level, was different from that seen in chronic liver failure, and he had no hepatic disease. After intensive chemotherapy, the serum ammonia level and glycine level decreased. In this patient, PCL seemed to be responsible for HOCF, hyperammonemia, and abnormal amino acid distribution. We experienced two more cases of multiple myeloma (MM) with HOCF, hyperammonemia, abnormal serum amino acid distribution, and consciousness disturbance of unknown origin. Those two cases showed slow waves in the electroencephalogram. Improvement was seen in their HOCF, hyperammonemia, and abnormal amino acid levels after chemotherapy. The possibility of MM as a cause of HOCF is discussed.

MRI of metanephric adenoma

We report the imaging findings of metanephric adenoma. US examination showed a protruding hypoechoic mass at the right kidney. CT revealed a well defined isodense mass with calcifications. On angiography, neither neovascularization nor tumor staining was revealed at all. The T1-weighted MR images showed a hypointense mass that was slightly hyperintense on T2-weighted MR images. Histologically, the tumor was metanephric adenoma.

[A correlation between atrial natriuretic peptide, brain natriuretic peptide, and perioperative cardiac and renal functions in open heart surgery]

Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are homeostatic hormones secreted from the human heart which protect both cardiac and the renal function. It is well known that these hormones increase in patients along with increases in the severity of congestive heart failure or acute myocardial infarction. However, as yet there are no reports in the literature on changes of the secreted level of ANP or BNP in surgical patients undergoing cardiopulmonary bypass (CPB). We evaluated the relationship between ANP, BNP, and perioperative cardiac and renal functions in patients with heart failure caused by CPB. We selected 45 patients of elective open heart surgery. We measured plasma level of ANP in all 45 cases, and BNP in 18 cases at preoperation, postoperation, and postoperatively three days after, respectively. At the same time, the cardiac index (CI) was measured. These cases were divided into the following groups. Group A1 (n = 23): cases in which the preoperative ANP was less than 40 pg/ ml. Group A2 (n = 22): cases in which the preoperative ANP was more than 40. Group B1 (n = 8): cases in which the preoperative BNP is increased to the level of 5 times as mach as the normal level. Group B2 (n = 8): cases in which the preoperative BNP is increased to the level of 5 times as much as the normal level. Group B2 (n = 10): cases in which the preoperative BNP was more than that of 10 times as mach as normal level. We then carried out a comparative study of the perioperative cardiac and renal functions in group A1 and A2, and group B1 and B2, respectively. In the terms of preoperative cardiac and renal function, there were no significant differences between groups A1 and A2, and there were no significant differences in urinary volume during CPB or post operative CI. However, the urinary volume during CPB of group B1 was significantly more than that of B2. Furthermore, the incidence of postoperative CI in group B1. Furthermore, the incidence of postoperative CI in group B1 was significantly higher than in B2. The preoperative and post operative third day BNP level had significant negative correlations with postoperative CI and postoperative third day CI, respectively (r = -0.641, -0.514, p = 0.008, 0.012). The postoperative ANP and BNP levels tend to a mean level roughly similar to one another because of the easing of cardiac stress by surgery and postoperative management. According to these results and several instances in the literature, a preoperative high BNP is considered to suggest a potential perioperative risk for cardiac and renal function. We conclude that determination of the plasma BNP level can be helpful for decisions related to CPB flow and measures taken to enhance cardiac and renal protection during surgery, and therefore is a useful reference for perioperative management.

Hyperdiploid myeloma cell as an indicator of poor prognosis and drug refractoriness

Although almost 40% of patients with multiple myeloma respond to initial chemotherapy, myeloma with no response to initial chemotherapy remains a serious problem. To understand the characteristics of drug-refractoriness of myeloma, fresh tumor cells from 13 untreated myeloma patients were fixed and stained with anti-human immunoglobulins and propidium iodide for subsequent flow cytometric analysis of DNA content. More than 10% of myeloma cells were hyperdiploid in eight cases (hyperdiploid + cases) while less than 10% of myeloma cells were hyperdiploid in five cases (hyperdiploid - cases). The proportion of hyperdiploid cells among all myeloma cells was highly correlated with incidence of myeloma cells with morphologically abnormal nuclei such as those with multiple-nuclei or convoluted nuclei (P = 0.001). Among the eight hyperdiploid + cases, two (2/8) showed good response to subsequent chemotherapy while four of five hyperdiploid - cases (4/5) responded well. Cases with poor response had more hyperdiploid myeloma cells (average 25.7% of all myeloma cells) than sensitive cases (average 6.8%), suggesting a contribution of hyperdiploid myeloma cells to primary drug resistance (P = 0.065). The 3 year survival rate of hyperdiploid+cases was 0% while that of the control group was 41.9%. These results suggest that myeloma cells with abnormal nuclear morphology may show hyperdiploidy and poor response to chemotherapy.

[Three-dimensional transesophageal echocardiographic assessment for prosthetic valves]

We evaluated three-dimensional transesophageal echocardiographic assessment of the implanted mechanical valves by rotational scanning method. Patients were 7 mitral valve replacement and one aortic valve replacement, 2 mitral and aortic valve replacement. In 2 cases of 7 mitral valve replacement, the prosthetic valve regurgitation was evaluated using by color Doppler echocardiography. In this study, multiplane transesophageal probe was used. It rotated at 2-degree intervals from 0 to 180 degrees and the three-dimensional reconstruction was performed by echo scan workstation system (TOMTEC Inc, Munich, Germany). In mitral valve replacement cases, the valve motion of bileaflet valve (St. Jude Medical valve and ATS valve) were showed very clearly. The struts was easily recognized in the St. Jude Medical valve (SJM valve) cases. In one of SJM valve cases, the pannus formation was revealed, but it did not disturb valve motion. The prosthetic valve regurgitation can be seen accurately. However, aortic valve and ball valve cases cannot be reconstructed because of artifact from prosthetic valve and ultrasonic direction. The prosthetic valve regurgitation, pannus formation which was difficult to be showed in two-dimensional echocardiography and relationship between annulus and sewing cuff can be evaluated by this three-dimensional echocardiography. In this study, this system has some problems, for example real-time evaluation is impossible, aortic valve and ball valve cases cannot be reconstructed. However, we think that this new technology is suitable for evaluating valve thrombus, valve dysfunction and paravalvular leakage. In conclusion, the three-dimensional echo-cardiography demonstrated, reliable and accurate examination, and it can evaluate various complications of prosthetic valve.

Apafant (a PAF receptor antagonist) suppresses the early and late airway responses in guinea pigs: a comparison with antiasthmatic drugs

We studied the effects of apafant (WEB 2086 BS), a specific and potent platelet activating factor (PAF) receptor antagonist, on the early and late airway responses in conscious and actively sensitized guinea pigs. An increase in airway resistance (Rs) was seen 1 min after the inhaled antigen challenge (early airway response), followed by another increase in Rs which peaked between 4 and 8 h after the provocation (late airway response). Oral administration of apafant as well as theophylline inhibited both early and late airway responses. Ozagrel, an inhibitor of thromboxane A2 synthetase, salbutamol, a beta2-adrenoceptor agonist, and dexamethasone significantly inhibited either the early or the late airway response only. Disodium cromoglycate inhibited neither the early nor the late airway response. The results showed that apafant inhibited both the early and late airway responses in sensitized guinea pigs and its effect was comparable or superior to that of anti-asthmatic drugs used clinically.

[A simultaneous operation of aortic root, arch replacement, and sternal elevation for Marfan's syndrome--a case report]

A 42-year-old male was transferred to our institution by his family doctor because of suspected type A aortic dissection with cardiac tamponade. His physical constitution gave the appearance of Marfan's syndrome. Contrast CT revealed DeBaky type 1 aortic dissection. Angiography detected an Annulo-aortic ectasia complicated by an aortic regurgitation (AR) grade IV. He also suffered from a severe funnel chest. We performed simultaneous procedures of aortic root, arch replacement, and sternal elevation. Upon operation, a staged aortic clamp technique was employed to reduce the period of cardiac arrest. In the sternal elevation, the bilateral internal thoracic arteries were preserved. Post operative course was uneventful. We consider it effective to employ the staged aortic clamp technique in a reconstruction of the entire thoracic aorta in the case of poor cardiac function and to preserve the bilateral internal thoracic arteries in sternal elevation in order to prevent infection.

[A reconstruction of the left ventricle for post infarction left ventricular aneurysm complicated by ventricular septal perforation--a case report]

A 68-year-old male with post myocardial infarction left ventricular aneurysm (LVA) complicated by ventricular septal perforation (VSP) was treated surgically. At first, he was admitted with acute myocardial infarction by a physician. Coronary angiography (CAG) revealed a total occlusion of the left anterior descending coronary artery. It was improved to 99% of stenosis by PTCR. Echo cardiography revealed the VSP. However, the patient was approached conservatively because of complications of severe pneuminitis and acute hepatitis. Cardiac catheterization was performed three months after admission. The data on the catheterization are as follows: Left ventricular (LV) wall dyskinesis is presented at segment 1-5. Global ejection fraction (EF) = 26%, Corrected EF = 40%, LVEDP = 36 mmHg, Qp/Qs = 1.8. Elective surgery was then performed with IABP, LVA was resected 90 x 50 mm in size under ventricular fibrillation. VSP, which was 9 mm in size, was closed directly with Teflon felt strips. LV plication was then made with 3.0 polypropylene under cardiac arrest. Reconstruction of the LV was then performed with a double patch, of which a cow pericardium was laid on top of a Gore-Tex patch. Post operative cardiac function was improved remarkably. We consider this procedure excellent because of the avoidance of thrombus and the maintenance of the LV form.

Hippocampal degeneration inducing impairment of learning in rats: model of dementia?

In the pharmacological field, the development of drugs effective for dementia is now widely anticipated because of the increase in the elderly population. Dementia has some histological degeneration in the brain, including the hippocampus. Preclinical evaluations of such drugs use animal models with memory impairment, since memory impairment is a major criterion of dementia. We therefore investigated two animal models with hippocampal degeneration. Neonatal administration of monosodium glutamate (MSG) induced specific degeneration of hippocampal pyramidal cells in the CA1 region of Wistar rats in adulthood. In these animals, the correct response rate during the acquisition period of light-dark discrimination learning was significantly lower than that in the control group. No significant changes were noted in the hippocampal concentrations of neurotransmitter substances, including acetylcholine and glutamate. In the second model, similar histological changes were observed at 3 weeks after oral administration of trimethyltin (TMT). These histological changes were accompanied by a reduction in the intrahippocampal concentrations of acetylcholine and glutamate. In the case of light-dark discrimination learning, neither pre- nor post-training administration of TMT affected the correct response rate during both the acquisition and retention test periods. In the case of 8-arm radial maze learning, the increase in correct response rate was significantly suppressed in comparison with that of the control group when TMT was administered at 4 weeks before starting the acquisition trial. This suppression was followed by a lower response rate in the retention test. On the other hand, the correct response rates in retention tests were not affected when TMT was administered after completion of the acquisition trial. These findings indicate that sole degeneration of the hippocampus was able to induce different types of memory impairment, and single evaluation of a drug with one learning paradigm was difficult to justify that a drug is effective for dementia.

Differential glycosylation of Bence Jones protein and kidney impairment in patients with plasma cell dyscrasia

Although Bence Jones protein (BJP) is generally accepted to be critically involved in the pathogenic process of kidney impairment in patients with myeloma, patients with BJP do not always have kidney dysfunction. As proteins often undergo glycosylation and alter their molecular nature, it is expected that the heterogeneity in kidney dysfunction can be explained at least partly by the differential affinity to the kidneys of BJP dependent on its glycosylation. Accordingly, we analyzed the structures of carbohydrates of urine BJP biochemically to correlate the structure with kidney function. BJP was obtained from 16 patients with myeloma, 2 patients with light chain amyloidosis, a patient with plasma cell leukemia, and a patient with Waldenstrom's macroglobulinemia. All BJP had five forms of oligosaccharides: three forms of biantennary oligosaccharides and two forms of triantennaries. The three biantennaries correspond to previously reported oligosaccharides on only lambda-type BJP, whereas the triantennaries are novel oligosaccharides found on BJP. Among the five oligosaccharides, the triantennary oligosaccharide Gal(beta)1-4GlcNAc(beta)1-2Man(alpha)1-6 [Gal(beta)1-GlcNA(beta)1-4(Gal(beta)1-4GlcNAc(beta) 1-2)Man(alpha)1-3]Man(beta)1-4GlcNAc(beta)1-4GlcNAc showed a significant negative correlation with the serum creatinine level (p = 0.015 by Spearman's correlation test, R = 0.744). Thus determination of BJP glycosylation may be useful for the evaluation of kidney impairment in patients with BJP.

Central role of vascular smooth muscle hyperreactivity in coronary hyperconstriction after balloon injury in miniature pigs

BACKGROUND

Coronary constrictive responses to autacoids become augmented 1 week after balloon injury in our swine model. The present study aimed to elucidate the mechanisms of this effect.

METHODS

In 12 hypercholesterolaemic miniature pigs, the coronary constrictive response to serotonin was examined angiographically 1 week after injury. After the angiographic study, organ chamber experiments using excised coronary artery were performed to clarify whether functional changes in endothelial cells or in vascular smooth muscle cells contributed to the hyperconstriction.

RESULTS

The coronary constrictive response to serotonin in vivo was significantly greater at the previously injured site than at the non-injured site. The degree of the hyperconstriction at the previously injured site exceeded that predicted from a geometric theory. Histological examination demonstrated that the previously injured site was almost covered with regenerated endothelial cells. In vitro studies demonstrated that serotonin caused significantly greater contraction in coronary artery strips, whether with or without endothelium, from the previously injured site than in those from the non-injured site. Endothelium-dependent relaxation in response to serotonin was comparable at the injured and non-injured sites.

CONCLUSIONS

These results suggest that the coronary hyperconstriction response to serotonin 1 week after injury results primarily from hyperreactivity of vascular smooth muscle. Whereas any contribution of endothelial dysfunction or the geometric effect may be minimal.