Effects of intraoperative administration of atrial natriuretic peptide

BACKGROUND

Biological activity of endogenous atrial natriuretic peptide (ANP) may decrease during cardiopulmonary bypass. To evaluate the effects of intraoperative administration of exogenous ANP in patients undergoing cardiopulmonary bypass, we conducted a prospective randomized study.

METHODS

Eighteen patients undergoing mitral valve surgery were randomized to receive either ANP treatment (ANP group; n = 9) or no ANP treatment (control group; n = 9). Atrial natriuretic peptide was given immediately after initiation of cardiopulmonary bypass for 6 hours (0.05 microg x kg(-1) x min(-1)). Plasma ANP, brain natriuretic peptide and cyclic guanosine monophosphate (cGMP) levels, hemodynamic variables and renal function were assessed perioperatively.

RESULTS

Administration of ANP increased plasma cyclic guanosine monophosphate levels, urine output and fractional sodium excretion, and decreased preload, afterload and plasma brain natriuretic peptide levels significantly (p < 0.05). Plasma cyclic guanosine monophosphate levels correlated with plasma ANP levels (r = 0.95, p = 0.0001), correlated with fractional sodium excretion (r = 0.53, p = 0.02), and correlated inversely with systemic vascular resistance (r = -0.54, p = 0.02).

CONCLUSIONS

Intraoperative administration of ANP had potent effects on natriuresis and systemic vasodilation by elevating cyclic guanosine monophosphate levels. The results suggest that the technique is useful for the management of hemodynamics and water-sodium retention after cardiopulmonary bypass.

Biological activity of endogenous atrial natriuretic peptide during cardiopulmonary bypass

To evaluate the effect of cardiopulmonary bypass (CPB) on atrial natriuretic peptide (ANP) biological activity in patients undergoing cardiac operations, we conducted a prospective study. Ten patients undergoing mitral valve surgery were enrolled. Plasma levels of ANP and cyclic guanosine monophosphate (cGMP), hemodynamic variables, and renal function parameters were assessed perioperatively. The molar ratio of cGMP to ANP (as a marker for ANP biological activity) decreased significantly (p < 0.05) during CPB despite similar plasma ANP levels. The ratio correlated inversely with the duration of CPB (r = -0.85, p = 0.002). The ratio also correlated with fractional sodium excretion (r = 0.65, p = 0.04) and correlated inversely with pulmonary vascular resistance (r = -0.79, p = 0.009) and atrial filling pressure (r = -0.84, p= 0.003) postoperatively. CPB decreased the molar ratio of cGMP to ANP, which may represent ANP biological activity, such as vasodilation and natriuresis. The phenomenon may contribute to water-sodium retention and pulmonary hypertension after cardiac surgery.

Endonucleases

Programmed cell death (PCD) involves hydrolysis of genomic DNA, which must be catalyzed by endonuclease(s) capable of digesting dsDNA. Plants have two major classes of endonucleases active towards dsDNA, Zn2+-dependent endonuclease and Ca2+-dependent endonuclease. Both classes are found among endonucleases nominated for machineries of PCD in plants. Survey of plant endonucleases in relation to PCD leads to a possibility that a different class of endonuclease reflects a different phase of PCD-associated DNA hydrolysis.

Total synthesis of the marine alkaloid (-)-lepadin B

An enantioselective total synthesis of (-)-lepadin B has been developed starting from (2S,4S)-2,4-O-benzylidene-2, 4-dihydroxybutanal. The key steps in the synthesis include the use of an aqueous intramolecular acylnitroso Diels-Alder reaction to afford the trans-1,2-oxazinolactam and Suzuki cross-coupling reaction to elaborate the (E,E)-octadienyl unit.

Study of cholelithiasis after gastrectomy

We studied cholelithiasis that occurred after gastrectomy in 52 patients (35 males and 17 females) encountered at our department between January, 1978 and December, 1998. Gastrectomy had been performed for gastric or duodenal ulcer in 35, gastric cancer in 14, gastroptosis in 2, and gastric trauma in 1 of these patients. Reconstruction after gastrectomy was performed by the Billroth II method (B-II method) in 31 patients, Billroth I method (B-I method) in 17, Roux-en-Y method (Roux-Y method) in 3, and esophagogastrostomy in 1. The period between gastrectomy and discovery of gallstones was 1-5 years in 9, 5-10 years in 10, and 10 years or longer in 33, or more than 60% of the patients. Gallstones were present in the gallbladder alone in 33, bile duct alone in 9, gallbladder and bile duct in 10; the percentage of bile duct stones was high. The type of stones was bilirubin-calcium stones in 21, black stones in 12, pure cholesterol stones in 1, combined stones in 4, mixed stones in 12, and others in 2; pigment stones accounted for 63.5%. Gallstones were symptomatic in 78.8% of the patients, and abdominal pain was the most frequent symptom. Bile was positive on bacterial culture in 68.4%, and Gram-negative bacilli were the most frequently isolated. Lymph node dissection, vagotomy, cholestasis, and biliary tract infection are considered to be related to cholelithiasis after gastrectomy.

Coronary artery bypass surgery in a patient with myasthenia gravis

A 73-year-old man with myasthenia gravis required quadruple coronary artery bypass grafting due to triple-vessel disease. Anesthetic management was performed with general anesthesia using a reduced dose of muscle relaxant with the aid of a neuromuscular transmission monitor. He was extubated 14 hrs after surgery without difficulty under this monitor. His postoperative course was uneventful. A patient with myasthenia gravis who required coronary artery bypass surgery was successfully performed by the deliberate preoperative evaluation of patient's myasthenic and cardiac status, and by the careful perioperative management.

A case of synchronous double cancers of the pancreas and stomach

Pancreatic cancer carries a poor prognosis, especially invasive ductal carcinoma of the pancreas. We present here the case of a 76-year-old man who developed synchronous double cancers of the stomach and pancreas. He was referred to our hospital in December, 1997, with a provisional diagnosis of carcinoma of the stomach. Laboratory data on admission showed normal levels except for the serum carcinoembryonic antigen level. Abdominal ultrasonography revealed a low echoic mass anterior to the pancreas, suggestive of a nodal metastasis. Intraoperative histological findings from the pancreatic nodule confirmed a primary pancreatic cancer. The diagnosis of double cancers of the stomach and pancreas was made, and subtotal gastrectomy and distal pancreatectomy with lymph nodes dissection were carried out. The histologic sections from the stomach showed a moderately differentiated tubular adenocarcinoma, whereas those from the pancreas showed a well to moderately differentiated tubular adenocarcinoma. Double carcinomas in this association are relatively rare.

[Indication and limitation of microwave coagulation therapy for stage IV-A hepatocellular carcinoma]

Patients with stage IV-A hepatocellular carcinoma have been considered to have dismal prognosis. However, among them there are many of patients with multiple carcinoma of multicentric origin, whose prognosis is not necessarily poor. For treatment of multiple carcinoma, preoperative evaluation for the malignant aggressiveness of each nodule, and for liver function impairment is essential. Although hepatic resection has a high curability, resection sometimes impair long term survival because of postoperative deterioration of liver function. In this point, heat ablation therapy such as microwave coagulation therapy is favorable treatment, and for some nodules at early stage heat ablation therapy would have a sufficient curability to achieve long term survival. Authors decide on the selection of treatment (resection or heat ablation therapy) according to preoperative evaluation for the malignant aggressiveness by diagnosis of tumor gross type, and for the degree of liver impairment by serum hyaruronic acid level.

Surgical treatment for acute type A aortic dissection in pregnancy: a case of aortic root replacement just after Cesarean section

A 25-year-old woman with Marfan syndrome in the 37th week of pregnancy was referred for acute chest pain and dyspnea. An emergency Cesarean section was performed because of fetal distress. Intraoperative echocardiography at the end of the Cesarean section showed dilatation of the aortic root and dissection of the ascending aorta. The patient underwent replacement of the aortic root and the ascending aorta on the following day because of uterine bleeding. The postoperative course was uneventful for the mother and her baby.

Participation of thromboxane A(2) in the cough response in guinea-pigs: antitussive effect of ozagrel

1. The purpose of this study was to investigate the involvement of thromboxane A(2) (TXA(2)) in the cough response in a guinea-pig cough model. Here, we describe results obtained using a selective TXA(2) synthetase inhibitor, ozagrel, and a selective TXA(2) agonist, U-46619. 2. Guinea-pigs were anaesthetized and exposed to an aerosol of capsaicin (100 microM) to elicit coughing. The number of coughs was 20.0+/-5.8 during capsaicin provocation (5 min), but only 2. 8+/-0.4 during a 5-min inhalation of phosphate-buffered saline (PBS) (P:<0.05). 3. TXB(2) levels in BAL were 101.4+/-8.0 and 58.4+/-8.7 pg ml(-1) following capsaicin and PBS inhalation, respectively (P:<0. 01), but there was no intergroup difference in the cell populations in BAL. 4. Inhalation of U-46619 did not induce a cough response by itself at concentrations of 100 ng ml(-1) to 10 microg ml(-1). However, it caused a 2 fold increase in the number of capsaicin-induced coughs. 5. To explore the source of the TXA(2), BAL cells were stimulated with capsaicin and the supernatants collected for analysis. The TXB(2) concentration in BAL was increased dose-dependently, indicating that TXA(2) is released from BAL cells in response to capsaicin. 6. Ozagrel was administered orally 1 h before a 5 min capsaicin provocation and the number of coughs was counted during the capsaicin inhalation. Ozagrel decreased the number of coughs dose-dependently (ED(50) value, 26.3 mg kg(-1)). 7. These results show that TXA(2) modulates the capsaicin-induced cough response by increasing capsaicin-sensitivity.

Effects of angiotensin-converting enzyme inhibitor during warm blood cardioplegia

BACKGROUND

Effects of captopril, an angiotensin-converting enzyme inhibitor, during warm blood cardioplegia were assessed in the blood-perfused, isolated rat heart.

METHODS

The isolated hearts were arrested for 60 minutes with warm blood cardioplegia given at 20-minute intervals and were reperfused for 60 minutes. The control group (n = 10) received standard cardioplegia and the captopril group (n = 10) received cardioplegia supplemented with captopril (2 mmol/L). Cardiac function, myocardial metabolism, and cardiac release of circulating adhesion molecules were assessed before and after cardioplegic arrest.

RESULTS

Left ventricular end-diastolic pressure and -dp/dt were significantly (p<0.05) lower and coronary blood flow was significantly (p<0.05) greater in the captopril group than the control group during reperfusion. The captopril group resulted in significantly (p<0.05) less cardiac release of lactate, thiobarbituric acid reactive substances during reperfusion. Cardiac release of intercellular adhesion molecule-1 was significantly (p<0.05) less in the captopril group at 60 minutes of reperfusion.

CONCLUSIONS

The results suggest that supplementation of captopril during warm blood cardioplegia provides superior myocardial protection by suppressing lipid peroxidation and leukocyte-endothelial cell interaction during reperfusion.

Determination of absolute stereochemistry and an alternative synthesis of homopumiliotoxin 223G: identification on chiral GC columns with the natural alkaloid

An alternative asymmetric synthesis of (+)-(lS,9aS)-homopumiliotoxin 223G (1) was accomplished via (1R,2R, 9aS)-1-(benzyloxy)-2-hydroxy-1-methyl-3[(E)-isobutylidene]++ +quinolizidi ne (4), which was synthesized according to the intramolecular nickel(II)/chromium(II)-mediated cyclization of the N-(iodoalkenyl)aldehyde 2. Compound 4 was converted to the acetate and subjected to reduction with lithium in ammonia, whereupon deprotection of the O-benzyl group and removal of the acetoxyl group occurred in a single operation to afford (+)-homopumiliotoxin 223G. The same sequence using (+/-)-4 was applied to the synthesis of racemic 223G. Gas chromatography of a sample of racemic 223G showed no separation into enantiomers on four different cyclodextrin-based chiral GC columns. We found, however, that the O-acetates of (+/-)-223G gave a nearly baseline separation on either a beta-cyclodextrin column or a permethylated beta-cyclodextrin column. The O-acetate of synthetic (+)-223G was identical on either of these two columns, with the first eluting O-acetate from acetylated (+/-)-223G and also with the acetylated 223G present in a frog skin extract, thus allowing us to confirm unambiguously the 1S,9aS absolute configurations of natural 223G.

Biocompatibility of heparin-coated extracorporeal bypass circuits: new heparin bonded bioline system

Biocompatibility of a new type of heparin-coated cardiopulmonary bypass equipment, the Bioline, was evaluated in coronary artery bypass surgery cases. The heparin-coated (H) group (n = 15; Quadrox Bioline oxygenator/reservior and Carmeda BioMedicus BP-80 centrifugal pump) was compared with the nonheparin-coated (N) group (n = 12; uncoated, otherwise similar oxygenator, centrifugal pump, tubing, and filter set). Both groups used full systemic heparinization. The peak values of neutrophil elastase, C3a, IL-6, and IL-8 at 2 h after cardiopulmonary bypass (CPB), and C3a levels at the end of CPB and at 2 h after CPB were significantly reduced in the H group compared with those of the N group. However, no statistically significant intergroup differences were observed in thrombin-antithrombin complex, D-dimer, beta-thromboglobulin, or platelet factor-4. No significant differences were observed in hemostasis time, postoperative 12 h blood loss, required amount of blood transfusion, or intubation time. In conclusion, the Bioline demonstrated partially improved biocompatibility, in terms of leukocyte and complement activation, and proinflammatory cytokine production. However, it did not improve platelet activation, coagulation, or fibrinolysis cascade under full systemic heparinization. As a result, the clinical beneficial impact seemed to be the minimum.

Obstruction of St Jude Medical valves in the aortic position: significance of a combination of cineradiography and echocardiography

BACKGROUND

Obstruction of the St Jude Medical valve (St Jude Medical, Inc, St Paul, Minn) is a rare but serious complication.

METHODS

Cineradiographic and echocardiographic evaluations of aortic St Jude Medical valves were simultaneously performed on 54 patients, with no signs of prosthetic valve dysfunction late after surgery.

RESULTS

Although closing angles of the leaflets corresponded closely with the manufacturer data, restricted opening of the leaflets (opening angle >/= 20 degrees ) was found in 16 (group D) of the 54 patients by means of cineradiography. The opening angles were equal to or less than 14 degrees in the other 23 patients (group N) and between 15 degrees and 19 degrees in the remaining 15 (group M). Doppler-derived transprosthetic pressure gradients were significantly higher (P =.03) and the velocity index was significantly lower (P =.003) in group D than in group N. However, no significant differences were found in those values between group N and group M. Replacement of the aortic St Jude Medical valves was performed in 5 of the 16 patients, and the remaining 11 have been followed up because of relatively low pressure gradients. The cause of restricted leaflet movement was pannus formation without thrombosis in 4 patients and valve thrombosis with pannus formation in one.

CONCLUSIONS

Reduced valve orifice area and restricted opening of the leaflets resulting from excess growth of pannus probably led to obstruction of the aortic St Jude Medical valves. A combination of cineradiography and echocardiography makes it possible to provide an accurate and detailed diagnosis of obstruction of the valve.

Expression levels of thymidine phosphorylase and dihydropyrimidine dehydrogenase in various human tumor tissues

Thymidine phosphorylase (dThdPase) is the rate-limiting enzyme that metabolizes 5'-deoxy-5-fluorouridine (5'-dFUrd, doxifluridine), an intermediate metabolite of capecitabine, to the active drug 5-fluorouracil (5-FUra), while dihydropyrimidine dehydrogenase (DPD) catabolizes 5-FUra to an inactive molecule. The susceptibility of tumors to fluoropyrimidines is reported to correlate with tumor levels of these enzymes. To obtain some insight into the tumor types susceptible to fluoropyrimidine therapy, we measured expression levels of these two enzymes in various types of human cancer tissues (241 tissue samples) by the ELISA methods. DPD exists in all the cancer types studied, such as bladder, breast, cervical, colorectal, esophageal, gastric, hepatic, pancreatic, prostate, and renal cancers. Among them, the cervical, hepatic, pancreatic, esophageal, and breast cancer tissues expressed high levels of DPD (median >70 U/mg protein), while high concentrations of the dThdPase were expressed in esophageal, cervical, breast, and pancreatic cancers and hepatoma (median >150 U/mg protein). The dThdPase/DPD ratio, which was reported to correlate with the susceptibility of human cancer xenografts to capecitabine, was high in esophageal, renal, breast, colorectal, and gastric cancers (median ratio of >1.5). In any of these three parameters, the inter-patient DPD variability for each cancer type was much larger than the DPD variability among cancer types; highest/lowest ratios for dThdPase, DPD, and dThdPase/DPD were 10-321, 7-513, and 2-293, respectively. These results indicate that measurements of the three parameters, DPD, dThdPase and dThdPase/DPD, would be useful criteria for selecting cancer patients suitable for fluoropyrimidine therapy rather than for selecting cancer types.

Gastric stromal tumor with CD34 immunoreactivity--a case report

Gastric stromal tumors are the most common mesenchymal tumors, and such submucosal mass lesions of the upper gastrointestinal tract occur frequently. A 54-year-old woman with no major complaint was admitted to our hospital for evaluation of a mass located between the stomach and the pancreas. Abdominal ultrasonography, computed tomography and endoscopic ultrasonography demonstrated a mass lesion which was located near the lesser curvature of the stomach. Selective left gastric arterial angiography revealed a hypervascular mass, and we diagnosed it as a leiomyosarcoma of the stomach. At laparotomy, there was a large solid mass 5 cm in diameter along the minor curvature of the stomach. Tumor resection with partial gastrectomy was performed, and the histological diagnosis was a gastric stromal tumor with CD34 immunoreactivity. We report a case of stromal tumor of the stomach with extramural growth and review the literature.

Successful removal of an infected pacemaker electrode by open heart surgery under extracorporeal circulation

A 33-year-old male with sick sinus syndrome, who had received a pacemaker implant 18 years earlier, was complicated with a generator infection. Although the infected generator was removed, he was suffered from the recurrent local infection associated with a retained pacemaker lead. After a new pacemaker system implantation from the other side of the subclavian vein, we attempted to remove the lead utilizing a pacemaker removal kit. However, this intervention procedure was unsuccessful, because fibrous adhesions had developed around the lead, accompanied by calcification along its course. As a last resort, we opened the heart under extracorporeal circulation and removed the lead under direct vision. The post-operative course was uneventful. In order to remove a long-term implanted pacemaker lead, the direct surgical procedure with extracorporeal circulation is a favorable mean alternative to conventional intervention techniques.

ATS prosthetic valve motion: an in vitro analysis

BACKGROUND AND AIM OF THE STUDY

We have reported clinical findings that normally functioning open pivot ATS valves did not open completely. In order to analyze features of the ATS valve motion more precisely, in vitro tests were conducted.

METHODS

Opening angles and pressure gradients of the ATS valve were measured and compared with those of the St. Jude Medical (SJM) valve under steady flow, but with various outlet configurations. Second, opening angles of the two valves were measured under pulsatile conditions in two different outflow configurations: (i) a 'straight outlet' where the leaflets did not extend into the tapering outflow chamber, and (ii) an 'abrupt enlargement outlet' where the leaflets extended directly into the enlarged outflow space. Third, flow visualization studies were made under steady flow conditions in the straight and abrupt enlargement outlet conduits, respectively.

RESULTS

Under steady flow conditions, opening of the ATS valve was restricted in most outflow configurations; only when the outlet angle was 0 degrees did the valve open fully. The SJM valve opened completely in all downstream configurations. Despite restricted opening in the ATS valve, the pressure gradient was similar in both valves. Under pulsatile conditions, both valves opened fully in the straight outlet; however, in the abrupt enlargement outlet the ATS valve opened incompletely and the SJM valve completely. Substantial turbulent flow was observed at the outside of the leaflet and corners of the conduit, notably with the ATS valve.

CONCLUSION

This study showed that the ATS valve did not open fully except when the outflow was straight, and the leaflet did not extend into an enlarged downstream chamber. Structural features of the ATS, such as its axis being located close to the straight edge and its leaflets extending further downstream from the ring orifice, may cause this unique valve behavior.

[Hemodynamic assessment of the Carpentier-Edwards pericardial valve compared with the St. Jude Medical valve in the aortic position using dobutamine-stress echocardiography]

To assess the hemodynamic performance of the prosthetic valve in the aortic position, we examined dobutamine-stress echocardiography (DSE) to the patients underwent AVR with CEP valve or SJM valve. In 23 mm size, there were no significant differences between CEP group and SJM group in Peak velocity of the aortic jet (PV), peak pressure gradient (PPG) and effective orifice area (EOA). On the other hand, in 21 mm size, PV and PPG of the CEP group were significantly lower than those of the SJM group after DSE. The EOA of the CEP group was significantly larger than that of the SJM group after DSE. Our results suggest that the hemodynamic function of the CEP valve is superior to that of the SJM valve especially in small aortic annuli.

A case report of surgical treatment of quadricuspid aortic valve associated with regurgitation

A case of a 65-year-old woman who had a quadricuspid aortic valve associated with aortic regurgitation is reported. The patient had severe aortic regurgitation and four equally divided aortic cusps. The valve abnormality was detected by a transesophageal echo and an aortography. The incomplete aortic valve was excised and replaced by a St. Jude Medical prosthesis. Although this case had no coronary abnormality, a coronary displacement is often reported in quadricuspid aortic valve cases. In order to perform an operation safely, accurate information which is obtained by a non-invasive examination of the transesoph-ageal echo is quite valuable as it can indicate the need for further preoperative examinations of the coronary arteries.

Identification of additional genes belonging to the LexA regulon in Escherichia coli

Exposure of Escherichia coli to a variety of DNA-damaging agents results in the induction of the global 'SOS response'. Expression of many of the genes in the SOS regulon are controlled by the LexA protein. LexA acts as a transcriptional repressor of these unlinked genes by binding to specific sequences (LexA boxes) located within the promoter region of each LexA-regulated gene. Alignment of 20 LexA binding sites found in the E. coli chromosome reveals a consensus of 5'-TACTG(TA)5CAGTA-3'. DNA sequences that exhibit a close match to the consensus are said to have a low heterology index and bind LexA tightly, whereas those that are more diverged have a high heterology index and are not expected to bind LexA. By using this heterology index, together with other search criteria, such as the location of the putative LexA box relative to a gene or to promoter elements, we have performed computational searches of the entire E. coli genome to identify novel LexA-regulated genes. These searches identified a total of 69 potential LexA-regulated genes/operons with a heterology index of <15 and included all previously characterized LexA-regulated genes. Probes were made to the remaining genes, and these were screened by Northern analysis for damage-inducible gene expression in a wild-type lexA+ cell, constitutive expression in a lexA(Def) cell and basal expression in a non-inducible lexA(Ind-) cell. These experiments have allowed us to identify seven new LexA-regulated genes, thus bringing the present number of genes in the E. coli LexA regulon to 31. The potential function of each newly identified LexA-regulated gene is discussed.

Differential diagnosis between tumor-forming pancreatitis and pancreatic cancer by percutaneous transhepatic portography and selective direct pancreatic venography

In 32 patients with tumor-forming pancreatitis and 109 patients with pancreatic cancer, the usefulness of percutaneous transhepatic portography (PTP) and selective pancreatic venography (SPV) for differential diagnosis of the two diseases was evaluated. The PTP images were type I in 53.1%, type II in 21.9%, type III in 12.5%, and type IV in 12.5% of the patients with tumor-forming pancreatitis and type I in 20.2%, type II in 23.9%, type III in 37.6%, and type IV in 18.3% of the patients with pancreatic cancer. Advanced images (type III or type IV) were observed in more than half the patients with pancreatic cancer. Mild images classified as type II were observed slightly more frequently in the patients with pancreatic cancer, but the differential diagnosis of the two diseases was difficult in patients showing type II PTP images. SPV findings were primarily hypervascularization (78.1%) and vasodilation (68.8%) in the patients with tumor-forming pancreatitis. Although encasement (smooth encasement) was noted in 31.3%, obstruction was found in only 3.1%. In the patients with pancreatic cancer, obstruction was observed in 85.3%, and encasement (irregular encasement) was noted in 78.9%. However, hypervascularization or vasodilatation was infrequent, and the tumor was characteristically imaged as a hypovascular area. PTP and SPV were considered to be useful for the differential diagnosis of tumor-forming pancreatitis and pancreatic cancer.

A case of Turner's syndrome complicated with desmoid tumor of the transverse colon

The association of Turner's syndrome and endometrial carcinoma has been previously established, but has never been described in conjunction with a desmoid tumor of the colon. A case is described of a colonic desmoid tumor developing in a 38-year-old female with Turner's syndrome. The association has not been previously reported. In this report, we describe a 38-year-old woman who has Turner's syndrome with a colonic desmoid and review the literature.