Effect of pili of Serratia marcescens on superoxide production and phagocytosis of human polymorphonuclear leukocytes

PURPOSE

To determine the role played by superoxide in renal scar formation following renal infection.

MATERIALS AND METHODS

The piliation of bacteria was assessed for its capacity to interact with human polymorphonuclear leukocytes (PMNs). Two recombinant strains having either MS or MR pili of Serratia marcescens were constructed.

RESULTS

The MS-piliated strain stimulated superoxide production of PMNs twice as much as the MR- or nonpiliated strains did. The MS-piliated strain was more susceptible to phagocytosis than was the MR- or nonpiliated strain.

CONCLUSION

These data suggest that the MS-piliated strain stimulates superoxide production of PMNs associated with phagocytosis, which leads to tissue damage in infected organs.

Percutaneous transvenous mitral commissurotomy for mitral stenosis patients with markedly severe mitral valve deformity: immediate results and long-term clinical outcome

In conclusion, to evaluate the efficacy and safety of PTMC for mitral stenosis patients with markedly severe valve deformity, we performed PTMC in 17 patients with severe mitral stenosis assessed by echocardiography (echo score > or = 12). This study demonstrates that PTMC can be performed safely and is clinically useful in treating the mitral stenosis patient with a markedly severe valve deformity.

Hepatolithiasis associated with cholangiocarcinoma

Hepatolithiasis is a risk factor for cholangiocarcinoma. It is difficult to make an accurate diagnosis before treatment. In a retrospective study, we identified characteristic clinical features of 103 patients with hepatolithiasis (group H) and 10 patients with hepatolithiasis associated with cholangiocarcinoma (group HC), and examined the methods for diagnosis and treatment. The main symptoms were abdominal pain, fever, and jaundice, although few patients in group HC had jaundice. The incidence of abnormal serum levels of carcinoembryonic antigen (CEA) in group HC was higher than in group H. The incidence of cholangiocarcinoma in cases in which most of the stones were present in the intrahepatic ducts of the left lobe (type I-L) was higher than the incidence in the other patients. Of the patients who underwent portography in group HC, portal veins in the portion of the liver containing the cholangiocarcinoma were not seen, and this region was atrophic in the operative specimens. The incidence of portal obstruction in portograms in group HC was higher than that in group H. The possibility of carcinoma should be kept in mind if there are high levels of CEA, if the location of the stones is classified as type I-L, or if portal veins cannot be seen on portograms. In such patients, liver resection should be considered because there may be undiagnosed cholangiocarcinoma.

Case of hepatolithiasis diagnosed by magnetic resonance cholangiography

We report a case of hepatolithiasis in which cholangiography by magnetic resonance (MR) imaging was useful in making a detailed diagnosis. Sonograms showed a high echoic lesion in the liver, and computed tomograms showed dilated intrahepatic bile ducts and atrophic hepatic tissue. By ordinary cholangiography, these findings were not made because of obstruction of the bile ducts by the stones. In MR cholangiograms, intrahepatic stones in dilated bile ducts in the posterior segment were seen, as were dilated bile ducts in the peripheral part of this segment. Posterior segmentectomy was done. The operative specimens had stones in the dilated bile ducts, and hepatic tissue was atrophic. MR cholangiography is useful to diagnose not only hepatolithiasis but also dilatation in the bile ducts. MR cholangiography should be tried if other examinations do not give sufficient information.

Portography in decision-making about indications for liver resection in hepatolithiasis

We studied the findings of portograms of patients with hepatolithiasis and the role of portography in decision-making about indications for hepatic resection. The subjects were 20 patients in whom hepatic arteriography including the portal phase or percutaneous transhepatic portography was done. We studied the relationships between the findings of the portograms and cholangiograms and hepatic atrophy or associated cholangiocarcinoma. The portal vein in the involved segment of the liver was obstructed in nine patients, and these patients had hepatic atrophy with or without cholangiocarcinoma. There were 16 patients with hepatic atrophy. Four of five other patients in whom protal shrinking was seen had hepatic atrophy. Bile ducts in the involved segment were obstructed in six patients with hepatic atrophy. In all five patients with cholangiocarcinoma, there was portal obstruction at the branching point in the hepatic hilum, with obstruction of the bile ducts at the same point in two of these patients. Hepatic atrophy and cholangiocarcinoma was more closely associated to changes of the portal vein than obstruction of the bile ducts. Portography is useful to diagnose hepatic atrophy and cholangiocarcinoma and for decision-making about indications for hepatic resection in hepatolithiasis.

The ultrastructure, kinetics and intralobular distribution of apoptotic hepatocytes after portal branch ligation with special reference to their relationship to necrotic hepatocytes

Apoptosis was originally defined as shrinkage necrosis, as a distinct mode of cellular death from coagulative necrosis in the rat liver lobes after portal branch ligation. To reveal the functional role of the apoptosis of hepatocytes in the volume reduction and recovery of normal hepatic architecture in portal-deprived liver lobes, we ligated the portal vein branch supplying the left and median liver lobes in Wistar rats. The liver lobes were perfusion-fixed with glutaraldehyde solution via the proximal site of the ligated portion of the portal vein on Days 1, 2, 4, 7 and 14 after operation and examined light and electron microscopically. On Day 2 after ligation, massive necrosis of hepatocytes occurred in the central to intermediate zones of the liver lobule, and apoptotic hepatocytes were observed in the boundary region between necrotic and normal areas. Such necrotic area-associated apoptosis of hepatocytes was most frequent on Day 2, declining thereafter. The sequential changes of the cell organelles in apoptotic hepatocytes were distinct from those in necrotic hepatocytes. On Day 7, when necrotic areas had almost disappeared the apoptosis of hepatocytes occurred mostly between intact hepatocytes in the "combined hepatic cell cords" which included no obvious sinusoidal lumen between hepatic cell cords. Such necrotic area-nonassociated apoptosis began to increase in frequency on Day 4, reached a peak on Day 7 and was gone by Day 14, when normal hepatic architecture was recovered. The present study suggests that both necrotic area-associated and non-associated apoptosis of hepatocytes may be induced by mild ischemia and contribute in part to the volume reduction of ligated liver lobes. It further reveals that the necrotic area-non-associated apoptosis of hepatocytes plays a role in reconstructing the architecture of hepatic cell cords after necrotic hepatocytes have undergone dissolution in the liver lobule.

Traumatic herniation of the buccal fat pad: report of case

Traumatic herniation of buccal fat pad in a case of twenty-month-old girl is presented. The lesion has been caused by the fall on the tooth brush in the mouth, and treated with excision and wound sutures.

Effect of ebselen on renal scarring in rats following renal infection

Renal scarring, which occurs following refluxing pyelonephritis, is considered to be involved in the development of reflux nephropathy. Prevention of renal scar formation requires immediate initiation of antimicrobial treatment; treatment delay results in renal scarring. We demonstrate that Ebselen, an antioxidant agent, given at a dose of 15 mg/kg twice a day prevents renal scarring in rats following direct renal parenchymal bacterial inoculation. In addition, using an ascending pyelonephritis model, which clinically resembles refluxing pyelonephritis in humans, we show that when initiation of antimicrobial treatment was delayed, coadministration of Ebselen prevents renal scar formation. These results show that Ebselen is effective in preventing renal scarring and suggest that the clinical use of this drug may prevent renal scar formation following pyelonephritis and progression to reflux nephropathy.

Cloning and sequencing of the gene coding for dextranase from Streptococcus salivarius

We cloned and sequenced the dextranase (Dex) (1,6-alpha-glucanhydrolase; EC 3.2.1.11)-encoding gene from Streptococcus salivarius (Ss) strain M-33. Recombinant clones from an Ss genomic library specifying Dex activity were identified as colonies surrounded by transparent halos on blue dextran plates. One of the clones had a 4.3-kb KpnI fragment containing the gene coding for an 826-amino-acid polypeptide with a molecular mass of 87.9 kDa, which corresponds well to that of native Dex from the Ss culture supernatant. There was no sequence homology between the gene encoding Ss Dex and the gene encoding dextran glucosidase of S. mutans, or between their protein products.

[Lys(-2)-Arg(-1)]endothelin-1 solution structure by two-dimensional 1H-NMR: possible involvement of electrostatic interactions in native disulfide bridge formation and in biological activity decrease

Addition of the Lys(-2)-Arg(-1) dipeptide, present in the precursor protein, to the N-terminus of endothelin-1 (ET-1), to form a 23-residue peptide (KR-ET-1) has been shown to greatly improve formation of native disulfide bridges and to dramatically decrease biological activity. Conformational analysis was carried out on this peptide. During protonation of the carboxyl groups, CD spectra showed a decrease in the helical contribution, and NMR spectra displayed strong chemical shift modifications, suggesting the importance of electrostatic interactions in the KR-ET-1 conformation. CD spectra and two-dimensional NMR experiments were performed to investigate the KR-ET-1 three-dimensional structure in water in the carboxylic acid and carboxylate states. Distance and angle constraints were used as input for distance geometry calculations. The KR-ET-1 carboxylic acid conformation was found to be very similar to ET-1, with a helix spanning residues 9-15 and an unconstrained C-terminal part. In contrast, in the carboxylate state, large changes in Arg(-1) and Phe14 chemical shifts and long-range NOEs were consistent with a conformation characterized by a helix extension to Leu17 and a stabilized C-terminal section folded back toward the N-terminus. In addition, thanks to NOEs with Cys11 and Phe14, the Arg(-1) side chain appeared well-defined. Simulated annealing and molecular dynamics calculations, supported an Arg(-1)-Glu10 salt bridge and an electrostatic network involving the charged groups of Trp21, Asp18, and Lys(-2). Moreover, stabilization of the KR-ET-1 C-terminal part is probably reinforced by hydrophobic interactions involving the Val12, Tyr13, Phe14, Leu17, Ile19, Ile20, and Trp21 side chains. In vitro, native disulfide bond formation improvement observed for KR-ET-1 could be ascribed to electrostatic interactions and more specifically to the Arg(-1)-Glu10 salt bridge. In vivo, similar interactions could play an important role in the native folding of the ET-1 precursor protein. On the other hand, modification in the environment and a reduced mobility of the KR-ET-1 Trp21 key residue, when compared to ET-1, could explain, at least in part, the strong decrease in biological activity.

T cell receptor-mediated signaling events in CD4+CD8+ thymocytes undergoing thymic selection: requirement of calcineurin activation for thymic positive selection but not negative selection

The goal of this study was to identify the differences of intracellular signals between the processes of thymic positive and negative selection. The activation of calcineurin, a calcium- and calmodulin-dependent phosphatase, is known to be an essential event in T cell activation via the T cell receptor (TCR). The effect of FK506, an inhibitor of calcineurin activation, on positive and negative selection in CD4+CD8+ double positive (DP) thymocytes was examined in normal mice and in a TCR transgenic mouse model. In vivo FK506 treatment blocked the generation of mature TCRhighCD4+CD8- and TCRhighCD4-CD8+ thymocytes, and the induction of CD69 expression on DP thymocytes. In addition, the shutdown of recombination activating gene 1 (RAG-1) transcription and the downregulation of CD4 and CD8 expression were inhibited by FK506 treatment suggesting that the activation of calcineurin is required for the first step (or the very early intracellular signaling events) of TCR-mediated positive selection of DP thymocytes. In contrast, FK506-sensitive calcineurin activation did not appear to be required for negative selection based on the observations that negative selection of TCR alpha beta T cells in the H-2b male thymus (a negative selecting environment) was not inhibited by in vivo treatment with FK506 and that there was no rescue of the endogenous superantigen-mediated clonal deletion of V beta 6 and V beta 11 thymocytes in FK506-treated CBA/J mice. DNA fragmentation induced by TCR activation of DP thymocytes in vitro was not affected by FK506. In addition, different effects of FK506 from Cyclosporin A on the T cell development in the thymus were demonstrated. The results of this study suggest that different signaling pathways work in positive and negative selection and that there is a differential dependence on calcineurin activation in the selection processes.

Solution structure of omega-conotoxin MVIIC determined by NMR

The solution structure of the P- and Q-type Ca2+ channel blocker, omega-conotoxin MVIIC (a peptidic neurotoxin composed of 26 amino acid residues), has been determined by 1H-NMR and simulated annealing calculations. The resulting calculated structures converged very well to a conformation with an average value of pairwised RMSD for N, C alpha and C' of 0.62 A. Lys-25 is buried in the molecule and less flexible so that among the four Lys residues, its side chain provides the lowest reactivity on biotinylation and the mono-biotinylation in this residue less influences the biological activity.

Neurohumoral variability in left ventricular dysfunction. SOLVD Investigators. Studies of Left Ventricular Dysfunction

The immediate and longer term variability of selected vasoactive- and volume-regulating neurohormones were measured in patients entering a substudy of the Studies of Left Ventricular Dysfunction--a randomized clinical trial in patients with left ventricular ejection fraction < or = 35%. The variability of these hormones has not been determined in a large cohort of patients. Immediate (short-term) variability was assessed by systematically comparing levels after 15 and 30 minutes of supine rest at the initial visit, and longer term variability was assessed by comparing 30-minute supine rest values at the initial visit with corresponding values taken at 30 minutes after 16 to 24 days of stable therapy. Initial values obtained at the first visit after 30-minute supine rest for all 209 patients were (mean +/- SEM) 512 +/- 21 pg/ml pg/ml for plasma norepinephrine, 1.9 +/- 0.2 ng/ml/hr for plasma renin activity, 3.0 +/- 0.1 pg/ml for plasma arginine vasopressin, and 129 +/- 5.3 pg/ml for plasma atrial natriuretic peptide. All variables were moderately increased relative to established normal values. There was a small but significant decrease from 15- to 30-minute supine posture in all neurohormones, except arginine vasopressin. In the presence of stable background therapy, no significant differences were found between measurements obtained after 30 minutes supine rest at the initial visit and 16 to 24 days later. Spearman correlation coefficients corresponding to immediate and longer term variability were high (range 0.55 to 0.79) (p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

[An autopsy case of traumatic subdural hematoma from arterio-venous malformation with diffuse axonal injury]

Diffuse axonal injury (DAI) is defined as widespread damage to axons in the white matter of the brain without focal injury such as contusion and acute subdural hematoma. A case of traumatic subdural hematoma from arterio-venous malformation accompanied by DAI is reported. A 58-year-old man was assaulted, and immediately lost consciousness, and remained unconscious during about 44 hours until his death. The autopsy revealed acute subdural hematoma (about 160 g) on left temporal lobe and left cingular, uncal and cerebellar tonsillar herniation, and tear and hemorrhage of the corpus callosum. Under this subdural hematoma, gray-whitish vascular lesion with subarachnoid hemorrhage was found. Histologically, this lesion was diagnosed as the arterio-venous malformation. Neuropathological examination of the corpus callosum, dorsolateral part of midbrain and superior cerebellar peduncle revealed DAI findings, such as swelling and ballooning of the myelin fibers, swelling and waving of axons, and retraction balls. Axon degenerations were also observed immunohistochemically by anti-200 kD neurofilament antibody. From the results, his unconsciousness from the moment of impact might be occurred from not only subdural hematoma but also DAI.

Interpretation of extravascular thermal volume of the lung in patients with chronic pulmonary diseases

To understand the significance of measured extravascular thermal volume of the lung (ETVL) in chronic pulmonary diseases, we measured ETVL using the double-indicator dilution technique in 17 emphysematous patients and 15 patients with pulmonary fibrosis. The level of ETVL in emphysema is significantly correlated with parameters reflecting the severity of the disease, including FEV1.0% (r = 0.54, p < 0.05), DLCO/VA (r = 0.54, p < 0.05), PaO2 (r = 0.61, p < 0.01), and mean pulmonary artery pressure (r = -0.61, p < 0.01). In pulmonary fibrosis, a significant inverse correlation was found between ETVL and PaO2 (r = -0.64, p < 0.02), DLCO/VA (r = -0.58, p < 0.05), and %VC (r = -0.61, p < 0.02). The mean level of ETVL in both groups of patients was lower than previously reported normal values. These results suggest that ETVL may reflect the decrease in pulmonary vasculature in emphysematous patients, while it may signify a decrease of pulmonary vasculature and increased volume of pulmonary interstitial tissue surrounding the pulmonary vasculature in pulmonary fibrosis. We conclude that ETVL may represent a good estimate of the condition of the pulmonary vasculature and interstitial tissue volume in patients with chronic pulmonary diseases.

Preventive effect of ulinastatin on renal scarring in rat model of pyelonephritis induced by direct or ascending infection with Serratia marcescens or Escherichia coli

Renal scarring is considered to be a characteristic of reflux nephropathy. The effects of ulinastatin, a strong inhibitor of polymorphonuclear leukocyte elastase, on renal scarring following direct parenchymal or intravesical ascending infection by Serratia marcescens or Escherichia coli were determined. Four days of treatment with ulinastatin initiated 2 or 5 days after infection prevented renal scarring. Doses of 1,000-4,000 units/kg inhibited renal scar formation, but 8,000 units/kg did not. These results suggest that it may be possible to limit renal scar formation in pyelonephritis by the use of an appropriate pharmacologic agent.

Effect of prednisolone on ascending renal infection due to biofilm disease and lower urinary tract obstruction in rats

A model of renal infection due to lower urinary tract obstruction and biofilm disease was constructed for the study of renal scarring by inserting glass beads coated with bacterial biofilm into the bladder of rats and then clamping the urethra. We previously reported the effect of antimicrobial therapy used in combination with the anti-inflammatory agent prednisolone to prevent renal scarring. In this study we investigated the effect of prednisolone on renal scar formation using our new model. Renal scarring could not be prevented in the group in which prednisolone was administered in the period during which the urethra was regularly being clamped. In contrast, scarring was prevented in the group that began to receive prednisolone after the period of clamping had ended. Therefore, in cases of lower urinary tract obstruction prednisolone should only be administered for the prevention of renal scarring after the obstruction has been resolved.