Effects of 7-nitroindazole on renal sympathetic nerve activity during acute cardiac tamponade in conscious rabbits

To investigate whether nitric oxide (NO) in the central nervous system is involved in the decrease in renal sympathetic nerve activity (RSNA) during acute cardiac tamponade in conscious rabbits, we examined the effect of 7-nitroindazole (7-NI), a selective inhibitor of neuronal nitric oxide synthase in vivo, on RSNA during acute cardiac tamponade in chronically installed conscious rabbits. Cardiac tamponade was produced by intrapericardial infusion of physiological saline at 2 ml/30 s. Mean arterial pressure (MAP) remained constant initially but RSNA increased to 218+/-24% when we started injection of physiological saline into the pericardial space. Concomitantly after MAP fell to 51+/-1 mm Hg by subsequent injection of the saline into the pericardial space, RSNA decreased to 45+/-6%. If 7-NI (50 mg/kg) was administered intraperitoneally 35 min before the beginning of cardiac tamponade, the decline in RSNA caused by cardiac tamponade was markedly counteracted. Brain nitric oxide synthase (NOS) activity in the cerebral cortex and medulla oblongata, assessed by the conversion of labelled arginine to citrulline, was inhibited by 48% and 44% after the intraperitoneal administration of 7-NI. These results indicate that acute cardiac tamponade elicits a biphasic effect on RSNA, which rises during non-hypotensive period and then falls during hypotension in conscious rabbits. The decrease in RSNA was abolished by treatment with 7-NI, suggesting that the abrupt decrease in RSNA during hypotension induced by acute cardiac tamponade is mediated by NO in the central nervous system.

The effects of intraportal administration of prostaglandin E1 on liver ischemia and hepatectomy in rats

The effects of intraportal administration of prostaglandin E1 (PGE1) on portal venous flow, hepatic arterial flow, peripheral tissue blood flow, and systemic arterial flow before and after 60 min total liver ischemia followed by 70% partial hepatectomy in rats were investigated. Total liver ischemia was induced by occluding the hepatoduodenal ligament for 60 min. PGE1 at a dose of 0.5 microg/kg/min was infused intraportally for 15 min before inducing hepatic ischemia (preischemic period) and for 60 min after ischemia (postischemic reperfusion period) in the treatment group. Normal saline was infused in the control group. Seventy percent partial hepatectomy was performed during ischemia. Serum biochemical analysis and liver tissue histology were carried out 1, 3, and 24 h, and 1 and 24 h after reperfusion respectively. One-week survival of the PGE1 group was improved to 70% compared to that of the control group of 30%. Postischemia reperfusion values of portal and peripheral tissue blood flows in the PGE1 group were 6.33 +/- 0.600 ml/min and 27.2 +/- 23.5 (arbitrary), and were significantly different from those of the control group of 4.34 +/- 0.400 ml/min and 23.5 +/- 5.54 (arbitrary), respectively. There was no significant difference in hepatic arterial flow between the two groups. Serum alkaline phosphatase decreased significantly in the prostaglandin group. Histological examination revealed a significant portal venous congestion in the control group 1 and 24 h after reperfusion. The extent of the sinusoidal congestion was also severe in the control group 24 h after reperfusion. It was concluded that PGE1 has a protective effect against liver damage when the liver was injured by warm ischemia and reperfusion followed by partial resection.

Modified hepatoduodenal ligamentectomy for advanced carcinoma of the biliary tract: the importance of preservation of the replaced left hepatic artery

Hepatoduodenal ligamentectomy (ligamentectomy) is the ultimate surgery for biliary tract carcinoma involving perioperative difficulties such as total hepatic ischemia during revascularization of the hepatic artery and the portal vein, patency of the reconstructed hepatic artery, and high incidence of related operative mortality. In the present study, modified ligamentectomies with extended right hepatic lobectomy, including resection of the caudate lobe, were performed on three patients with advanced biliary tract carcinoma in whom the left hepatic artery had been replaced and the original artery was preserved. In all patients, postoperative courses were uneventful: success of the resection was confirmed by histological examination. This procedure enabled en bloc resection of hepatoduodenal ligament with positive cancer invasion to take place. It was carried out safely without concern for the difficulties described above. In our view, ligamentectomy should be performed in all such cases.

Microsomal cytochrome P-450 monooxygenase system and its drug-metabolizing activity after partial portal vein ligation in the Rat

Percutaneous transhepatic portal vein embolization (PTPE) has been used to decrease the risk of hepatic failure after hepatectomy in patients with poor liver function. The effect of PTPE on hepatic drug-metabolizing activities is not clear. Therefore we examined the effect of portal vein branch ligation, a model of PTPE, on hepatic drug-metabolizing activities in Sprague-Dawley rats. Ligated and nonligated lobes were harvested separately. Drug-metabolizing activities and concentrations of components of the microsomal cytochrome P-450 monooxygenase system were examined. In ligated lobes, drug-metabolizing activities (lidocaine and aminopyrine) and enzymatic concentrations of the microsomal cytochrome P-450 monooxygenase system gradually decreased over 10 days. In nonligated lobes these functions were depressed rapidly to 60% of those before PBL but then recovered 10 days after PBL. From the viewpoint of drug metabolism, hepatic dysfunction occurred in both ligated and nonligated lobes.

Wound healing of intestinal anastomosis after digestive surgery under septic conditions: participation of local interleukin-6 expression

This study aimed to evaluate the integrity of anastomotic wound healing after digestive surgery under septic conditions and to observe local interleukin-6 (IL-6) expression around the anastomotic segment. Experimental animals were separated into lipopolysaccharide (LPS) and control groups. Each was injected with LPS or normal saline solution into the peritoneal cavity 24 hours before transection and anastomosis of the colon. The anastomotic bursting pressure (ABP) and tissue hydroxyproline concentration (HP) were measured as indicators of wound healing. Immunohistochemical staining for IL-6 was performed on tissue samples obtained from the anastomotic segment, lung, liver, and kidney. The reactive cells were counted by light microscopy. The ABP and HP were significantly lower in the LPS group than the control group 7 days after the surgery. In the LPS group, IL-6 expression around the anastomotic segment was enhanced 1 and 6 hours after surgery but suppressed 24 hours afterward. In contrast, IL-6 expression in lung, liver, and kidney was enhanced in the LPS group 24 hours after surgery but not in the control group. It is suggested that anastomotic wound healing is impaired after digestive tract surgery under septic conditions, and local IL-6 expression participates in wound healing.

c-erbB-2 protein is expressed in hepatolithiasis and cholangiocarcinoma

AIMS

The c-erbB-2 proto-oncogene encodes a transmembrane protein which is highly homologous to epidermal growth factor receptor. Overexpression of this c-erbB-2 protein has been reported in many human carcinomas, including breast carcinoma. However, there have been few studies of the expression of c-erbB-2 in cholangiocarcinoma and hepatolithiasis, a condition occasionally associated with cholangiocarcinoma.

METHODS AND RESULTS

In this study, we evaluated immunoreactivity for the c-erbB-2 protein in human cholangiocarcinomas (n = 47), hepatolithiasis (n = 20), fetal livers (n = 36) and normal adult livers (n = 6). In normal adult livers and fetal livers, expression of c-erbB-2 protein could not be detected in hepatocytes or intrahepatic biliary cells. In hepatolithiasis, there was overexpression of c-erbB-2 in 15/20 (75%). The expression was found with a membranous pattern on the proliferated intrahepatic bile ducts and proliferated intrahepatic peribiliary glands around the bile ducts containing stones. Hepatocytes were negative for c-erbB-2 protein. Moreover, the biliary cell expression of the c-erbB-2 protein correlated significantly with Ki67 labelling index. On the other hand, aberrant expression of c-erbB-2 was found in 33/47 (70%) cholangiocarcinomas. The c-erbB-2 expression in cholangiocarcinomas did not correlate with Ki67 labelling index or p53 expression.

CONCLUSIONS

These results indicate that aberrant expression of c-erbB-2 protein is found in cholangiocarcinoma and also in noncancerous biliary proliferative lesions such as hepatolithiasis. These findings also suggest that c-erbB-2 oncogene participates not only in cholangiocarcinogenesis but also in biliary cell proliferation in non-neoplastic conditions.

Morphological and functional alterations to sinusoidal endothelial cells in the early phase of endotoxin-induced liver failure after partial hepatectomy in rats

Liver failure following major hepatectomy is characterized pathologically by massive hepatic necrosis, which is thought to begin with injury of sinusoidal endothelial cells (SECs). To examine the early events of SECs leading to hepatic damage, we performed time-course analyses of the morphological and functional perturbation of SECs after endotoxin administration to hepatectomized rats. At 1.5 h after endotoxin injection, when hepatocellular damage was not yet evident, SECs showed augmented expression of intercellular adhesion molecule-1, with frequent adherence of infiltrating leucocytes and ultrastructural features of defenestration and hypertrophied cytoplasm enriched with cell organelles. The serum level of hyaluronate, as an indicator of the functional state of SECs, was significantly elevated. At 3 h, SECs underwent necrosis and disruption, accompanied by fibrin deposits with concomitant hepatocellular necrosis. The morphological and functional alterations of SECs precede necrotic changes in hepatocytes and SECs in endotoxin-induced liver failure after partial hepatectomy.

Treatment of recurrent hepatocellular carcinoma by hepatectomy with right and middle hepatic vein reconstruction using total vascular exclusion with extracorporeal bypass and hypothermic hepatic perfusion: report of a case

We report herein the case of a patient who had previously undergone a lateral segmentectomy for hepatocellular carcinoma (HCC) in whom recurrent HCC invading the trunk of the right and middle hepatic veins in a damaged liver was treated by reconstruction of both hepatic veins, using total vascular exclusion with extracorporeal bypass and hypothermic hepatic perfusion. Reconstruction was performed using a graft taken from the left external iliac vein and divided into two pieces. Hepatic ischemia lasted for 91 min during the procedure and the intrahepatic temperature, as monitored by inserting a needle-type thermometer, was decreased to 11 degrees C throughout the procedure. The peak levels of serum glutamic pyruvic transaminase, lactate dehydrogenase, and total bilirubin were 363 IU/l, 1198 IU/ml, and 2.8 mg/dl, respectively, on postoperative day (POD) 2. The patient's postoperative course was uneventful except for mild, temporary swelling of the left leg. Postoperative computed tomography and magnetic resonance imaging examinations disclosed no obstruction of either graft, and the patient was discharged on POD 40.

[A case of active infective endocarditis in the remission phase of virus-associated hemophagocytic syndrome]

We successfully treated a case of active infective endocarditis in the remission phase of virus-associated hemophagocytic syndrome (VAHS). A 21-year-old man was admitted to our hospital for fever, arthralgia, and general fatigue. His blood cultures revealed staphylococcus epidermidis. He underwent urgent aortic valve replacement and closure of the abscess cavity because of an ineffective antibiotic therapy and a progressive left heart failure. Operative findings showed about 100 ml bloody pericardial effusion, fresh vegetation on the aortic left coronary and non-coronary leaflets, and aortic root abscess just below the left coronary ostium. The aortic root abscess extended to the left ventricular wall between the base of left atrial appendage and the base of main pulmonary artery and was in the state of impending rupture. The left main coronary artery was fully exposed after debridement in the abscess cavity. It was thought that left atrial appendage as a pedicle was useful for filling up the abscess cavity to protect infection.

First results from the crystal structure analysis beamline at SPring-8

Results from the first measurements at the crystal structure analysis beamline (BL02B1) at SPring-8 are presented. The capabilities of this beamline are also discussed.

Two distinct anti-allergic drugs, amlexanox and cromolyn, bind to the same kinds of calcium binding proteins, except calmodulin, in bovine lung extract

In order to explore candidates for proteins required in exocytosis, we used two anti-allergic drugs, amlexanox and cromolyn, which inhibit IgE mediated degranulation of mast cells and basophils, as molecular probes in affinity chromatography. These two drugs chiefly bound to the same kinds of calcium binding proteins in bovine lung. These proteins were as follows: bovine calgranulin C homolog, an 8-kDa unknown protein, S-100L, calgranulin B, calcyphosine, and annexins I-V. The homologous affinity of the two drugs to these proteins is in accord with the similar anti-allergic property of both drugs. From these findings it is presumed that these drugs interact with these proteins and affect pharmacologically the degranulation.

The relationship between the mitral annulus and left ventricular outflow tract

Mitral annular inflexibility due to rigid prostheses (ring or valve) has long been considered to contribute to the mechanism of dynamic left ventricular outflow tract (LVOT) obstruction after mitral repair or replacement. In clarifying the geometric relationship between LVOT orifice and mitral valve annulus (MVA) in eight normal subjects, the authors have endeavored to show how that a rigid mitral prosthesis might obstruct the LVOT based on the assumption that any rigid prosthesis necessarily follows the motion of the posterior half of the MVA (MVApost) in the course of every heart beat. During systole, the relationship between the MVApost and the approximated plane of the LVOT orifice was constant. However, with the respect to the relationship between the LVOT orifice and the approximated plane of the MVApost (PI-MVApost), the intersection between the two shifted toward the apex during systole. Assuming the prosthesis is aligned on the MVApost with the same orientation as the PI-MvApost, this shift implies a reduction in the effective size of the LVOT orifice due to the prosthesis. The calculated obstruction rate was 24.9% (0 ms), 30.9% (100 ms), 35.5% (200 ms), and 45.4% (300 ms). These results indicate the importance of maintaining the flexibility of the MVA after mitral valve surgery.

Hepatic protein synthesis in the regenerating rat liver after hepatopancreatectomy

To evaluate the effects of hepatopancreatectomy on the regenerative process of the liver, the serum protein changes, hepatic protein synthesis (HPS), and bromodeoxyuridine (BrdU) labeling index were measured in rats. Sprague-Dawley rats were divided into four groups according to the type of resection: A simple laparotomy was performed in the sham group; 68% of the liver was excised in the Hx group; 45% of the pancreas was excised in the Px group; and 45% of the pancreas and 68% of the liver were excised simultaneously in the HPx group. Serum total protein and albumin levels were significantly lower in the HPx group compared to the other three groups on postoperative day (POD) 3 (P < 0.05). HPS was markedly increased in the Hx and HPx groups. In the Hx group, it was significantly higher, peaking on POD 2, compared to the HPx group (P < 0.05), while in the HPx group, it was significantly higher compared to the Hx group (P < 0.05), peaking on POD 3. The BrdU labeling index, as a marker of DNA synthesis, was significantly suppressed in the HPx group on POD 1 compared to the Hx group (P < 0.05). Thus, compared to hepatectomy alone, hepatopancreatectomy suppresses DNA synthesis, causing a delay in the increase of protein synthesis in the regenerating liver, resulting in a more marked decrease in the serum protein level.

[Surgery of aortic arch aneurysm combined with other cardiovascular lesion]

From 1995 to 1996, we performed aortic arch replacement using antegrade cerebral perfusion under deep hypothermia in 7 patients, in whom 4 cases accompanied with cardiac lesion which treated simultaneously and 3 cases had abdominal aortic aneurysm. We compared the surgical results between cases with (group II, n = 4) and without (group I, n = 3) combined cardiovascular lesion. There is no difference between two groups in the cerebral perfusion time and the amount of bleeding and blood transfusion. The cardiac ischemic time and bypass time were insignificantly longer in group II than in group I. We experienced no early death and no cardiac and brain complication in both groups. Three cases with abdominal aortic aneurysm had two-staged operation successfully after arch surgery within a half year. In conclusion, we successfully treated aortic arch aneurysm even in patients combined with other cardiovascular lesion as well as in patients without that.

Dynamic change in the left ventricular base with or without a rigid mitral valve prosthesis

To evaluate the narrowing of the left ventricular outflow tract (LVOT) during systole caused by a rigid mitral prosthesis, the geometric relationship between the prosthesis (or the mitral annulus) and the left ventricular base (LVB) was studied in five patients with mechanical mitral valve prostheses and eight normal subjects. The images of the mitral valve annulus (MVA) and the LVOT orifice reconstructed in three dimensions were projected on the plane of the LV base. Calculating the areas of these projected images (i.e., those for MVA [Sm], LVOT orifice [So], the LVB [Sb; Sb = Sm + So]), the MVA-LVB ratio (Sm/Sb) was determined. In the normal subject, the MVA-LVB ratio was nearly constant during systole (59 +/- 5% at 0 msec and 62 +/- 7% at 300 msec, respectively), whereas in the patients with prostheses, the ratio increased from 61 +/- 4% (0 msec) to 69 +/- 4% (300 msec). The increase in MVA-LVB ratio reduces the proportionate share of LVOT orifice in relation to the total LVB. The ideal mitral valve prosthesis should be flexible at the annulus to attain good performance in LVB dynamics.

Imaging of the orifice of the left ventricular outflow tract: technique and initial results

The mechanism of left ventricular outflow tract (LVOT) obstruction in the patient after mitral valve replacement or repair was examined with the aid of 2D echocardiography. For the interpretation of the spatial relationship between the aortic root and mitral annulus, however, the 2D display is sometimes inadequate since it may not simultaneously capture these structures in each center. We developed a method to clarify this relationship in 3D based on magnetic resonance images. We defined the office of the left ventricular outflow tract (LVOT orifice), consisting of, in turn, a muscular region, i.e., edge of the interventricular septum, and an annular region, i.e., the annulus of the anterior mitral leaflet. In this paper we present image data obtained from one of eight normal subjects examined and compare this with data of one of two patients who preoperatively suffered degenerative mitral regurgitation and subsequently underwent chordal-preserving mitral valve replacement, in which anterior chordae were reattached to the anterior annulus. In the normal subject, the mitral annulus exhibited a flexible change in shape during the systole, maintaining sufficient LVOT orifice size. In the patient, the prosthetic valve exhibited translational motion during systole, resulting in dynamic LVOT obstruction. This phenomenon was also observed in one other case. Furthermore, the lateral view of the LVOT orifice revealed a projection of the prosthetic valve into the LVOT, causing mechanical LVOT obstruction. The finding that translational motion of the prosthetic valve with an inflexible mitral annulus results in dynamic LVOT obstruction may support the hypothesis that annular rigidity causes dynamic LVOT obstruction after mitral valve repair with a rigid prosthetic ring.

Effects of an immunosuppressive agent, tacrolimus (FK-506), on the activities of cytochrome P-450-linked monooxygenase systems in rat liver microsomes

The effects of an immunosuppressive agent, tacrolimus (FK-506), on the activities of cytochrome P-450-linked monooxygenase systems with respect to three cytochrome P-450 isozymes in rat liver microsomes were investigated. FK-506 non-competitively inhibited the aniline p-hydroxylase, p-nitroanisole O-demethylase and lidocaine N-deethylase activities of cytochrome P-450-linked monooxygenase systems, these activities being mainly catalyzed by cytochromes P-450 CYP2E1, CYP2C11 and CYP3A4, respectively, and the Ki values of the activities for FK-506 were determined to be 605, 491 and 97 microM, respectively. The inhibition of cytochrome P-450-linked monooxygenase systems by FK-506 seemed to involve the direct inhibition of cytochromes P-450 because the NADPH-cytochrome c reductase and NADPH-ferricyanide reductase activities of NADPH-cytochrome P-450 reductase were not affected by the presence of 1 mM FK-506 at all. A spectrophotometric study showed that a reverse type I spectral change was induced on the addition of FK-506 to rat liver microsomes, and the Ks value was apparently 125 microM. On the other hand, the EPR spectra of cytochromes P-450 in rat liver microsomes were not affected by 1 mM FK-506. These results suggest direct interaction between FK-506 and cytochrome P-450 apoproteins, except for the heme iron regions of cytochromes P-450, resulting in inhibition of the drug-metabolism activities catalyzed by cytochromes P-450.

Mitral annular flexibility

An analysis of three-dimensional movement of the mitral valve annulus (MVA) may address the question of geometrical change after mitral valve repair to preserve mitral annular function. Conventionally, annular contraction has been studied for this purpose. We investigated this geometrical change occurring in the anterior half of the MVA and discuss its clinical significance. Three-dimensional images of the MVA during systole were reconstructed from magnetic resonance images of eight normal subjects. The posterior half of the MVA exhibited translational motion. We assume that this portion, exhibiting translational motion as well as contraction, purely follows the motion of the left ventricular contraction. Compensating for the discrepancy between the motion of the aortic root and that of the posterior half of the MVA, the anterior half exhibited a flexible change in shape during systole, thus maintaining a sufficient left ventricular outflow tract (LVOT). The increase in the extent of displacement of the anterior MVA from the posterior half of the MVA during systole, which was 3.6 +/- 1.0 mm (mean +/- SD), indicates the annular flexibility. The preservation of annular flexibility may prevent LVOT obstruction. Further geometrical analysis of patients after mitral repair will clarify annular function as presented in this article.

[A case with thyroid carcinoma associated with falsely increased TSH values]

A 63-year-old woman with papillary thyroid carcinoma showed increased TSH values (measured by two-site immunometric assay kit). X-ray and endocrinological examinations did not prove the coexistence of pituitary neoplasm. TSH values which were measured by using an another TSH assay system (TSH RIABEAD II assay kit) revealed normal range. Measured TSH values were reduced by adding mouse IgG into serum. These findings suggest that substances in serum, which can link reagent mouse antibody in the assay system, may give falsely increased TSH values. We should be aware that two-site immunometric assay may give falsely increased hormone values due to the appearance of substances against anti-animal antibodies in serum.

Effect of preoperative portal vein embolization on major hepatectomy for advanced-stage hepatocellular carcinomas in injured livers: a preliminary report

With the aim of minimizing postoperative liver dysfunction and promoting increased resectability, we employed portal vein embolization (PVE). In this study, the effect of PVE on major hepatic resection for advanced-stage hepatocellular carcinoma (HCC) in injured livers was evaluated. PVE was performed prior to hepatectomy in 13 patients with stage III and IV HCCs. Following PVE, right trisegmentectomy was performed in 3 patients, extended right lobectomy in 3 and right lobectomy in 7. To evaluate the effect of PVE, the changes in liver functional capacity and estimated remnant liver volume (ERLV), determined by computed tomography, were examined before and after PVE. The operative morbility, mortality, and survival rates after hepatectomy were also assessed. By 2 weeks after PVE, ERLV had increased in all patients, by an average of 28%, and the mean resection rates had decreased from 70.0% to 62.2%. Postoperatively, the 30-day mortality rate was 15.3%, and the 1- and 2-year survival rates were 69% and 46%, respectively. The results of this study indicate that resectability can be increased, and major hepatectomy can be made safer by employing PVE preoperatively, in view of the fact that major hepatectomy was not considered feasible without PVE in these patients.

Increase in portal blood interleukin-6 soon after the commencement of digestive surgery

To determine whether cytokines produced in the operative field during digestive surgery selectively spill over into the portal blood, the changes in interleukin-6 (IL-6) levels in portal and peripheral venous blood were assayed at several points in time from the commencement of surgery until 14 days later, in 11 patients. Similar changes in the IL-6 levels were observed in the portal and peripheral blood samples; however, the IL-6 levels in the portal blood reached a maximum 6-12h after the commencement of surgery, being earlier than in the peripheral venous blood. In fact, between 3 and 12h after the commencement of surgery, the IL-6 levels were higher in the portal blood by 33-81 pg/ml. By 24h or more after the commencement of surgery, the IL-6 levels did not differ significantly in the two types of blood samples. Moreover, the C-reactive protein levels 2 days after surgery were even more closely correlated to the maximum IL-6 levels in the portal blood than to those in the peripheral venous blood. These results suggest that IL-6 produced during intra-abdominal digestive surgery initially enters the portal blood, being trapped by IL-6 receptors in the liver, where it may regulate the synthesis of acute-phase proteins as a hepatocyte-stimulating factor.