Performance of the new biological small- and wide-angle X-ray scattering beamline 13A at the Taiwan Photon Source.

Recent developments in the instrumentation and data analysis of synchrotron small-angle X-ray scattering (SAXS) on biomolecules in solution have made biological SAXS (BioSAXS) a mature and popular tool in structural biology. This article reports on an advanced endstation developed at beamline 13A of the 3.0 GeV Taiwan Photon Source for biological small- and wide-angle X-ray scattering (SAXS-WAXS or SWAXS). The endstation features an in-vacuum SWAXS detection system comprising two mobile area detectors (Eiger X 9M/1M) and an online size-exclusion chromatography system incorporating several optical probes including a UV-Vis absorption spectrometer and refractometer. The instrumentation and automation allow simultaneous SAXS-WAXS data collection and data reduction for high-throughput biomolecular conformation and composition determinations. The performance of the endstation is illustrated with the SWAXS data collected for several model proteins in solution, covering a scattering vector magnitude q across three orders of magnitude. The crystal-model fittings to the data in the q range ∼0.005-2.0 Å-1 indicate high similarity of the solution structures of the proteins to their crystalline forms, except for some subtle hydration-dependent local details. These results open up new horizons of SWAXS in studying correlated local and global structures of biomolecules in solution.

Stabilization of blood methylmalonic acid level in methylmalonic acidemia after liver transplantation.

Methylmalonic acidemia with complete mutase deficiency (mut(0) type) is an inborn error of metabolism with high mortality and morbidity. LT has been suggested to be a solution to this disease, but elevation of urinary and blood MMA was still observed after LT. In this study, we measured dry blood spot MMA and its precursor propionyl-carnitine (C3-carnitine) for mut(0) patients. The results revealed that when C3-carnitine rose during metabolic stress, MMA rose exponentially (up to 1000 micromol/L) in patients who did not undergo LT. In patients who underwent LT, MMA rose to 100-200 micromol/L when C3-carnitine reached 10-20 micromol/L. However, when C3-carnitine rose further to 40-50 micromol/L, MMA levels just stayed put. Therefore, LT stabilized blood MMA level, though there might be a threshold for blood MMA clearance by the donor liver. This finding should be critical to understand the long-term outcome for LT in methylmalonic acidemia.

Liver transplantation for acute hepatic failure.

INTRODUCTION: The mortality rate of acute hepatic failure (AHF) with conservative treatment is 40% to 90%, depending on the etiology. Hepatitis B infection is the major cause of AHF in Asia. In this study, we examined the role of liver transplantation for adult patients with AHF. METHODS: Sixteen patients with AHF received liver transplants in the past 6 years. Eight patients received cadaveric donor and another 8 living-related donor grafts. Fifteen patients suffered from hepatitis B-related disease and 1 had drug-induced AHF. Extracorporeal charcoal hemoperfusion was used as a bridge to liver transplantation in the first 2 patients and plasma exchange was used in the following patients. RESULTS: One patient died 1 month after the operation due to primary nonfunction. The other 15 patients are alive with good graft function at 2 months to 6 years follow-up. The success rate is 94%. Postoperative complications included infection in 10 patients (62.5%), acute rejection in 4 patients (25%), and biliary complication in 2 patients (12.5%). No neurological complications were noted. CONCLUSION: Liver transplantation is the most effective treatment for patients with AHF. Living donors may be considered due to the organ shortage and the critical patient disease.

Do patients with acute liver failure have a better chance to receive liver grafting?

OBJECTIVE: Patients with acute hepatic failure (AHF) were always given first priority on the transplant waiting list. We investigated whether AHF patients will deprive other patients on the waiting list of the chance of liver transplantation (LTx). METHODS AND RESULTS: From January 1999 to March 2003, a total of 423 patients were on the transplant waiting list at the National Taiwan University Hospital. Sixty-five of the patients had AHF caused by hepatitis-B-related disease (HBV, n = 52, 80%), Wilson disease (n = 3, 4.6%), drug-induced AHF (n = 3, 4.6%), and other causes (n = 7, 10.8%).Thirty-three patients died and 16 survived by medical treatment. Two received LTx abroad and 14 underwent LTx at our hospital (7 living-related; 7 cadaver). A total of 140 patients died while waiting for a transplant during the period studied. Of them, 107 were among 358 non-AHF patients (30%), and time-to-death interval was 133 +/- 175 days (median: 62); 33 were among 65 AHF patients (51%); time to death was 19 +/- 28 days (median: 8). There were 35 cadaver donor livers available during the period; 28 of 358 non-AHF patients (7.8%), and 7 of 65 AHF patients (10.7%) received cadaveric LTx. Their waiting time totaled 342 +/- 316 and 12 +/- 9 days, respectively (P < .0001). CONCLUSION: Most AHF patients died unless they received liver grafts. Even with a higher priority assigned to them, AHF patients still have little chance to get a cadaver donor liver in Taiwan, and non-AHF patients have an even slimmer chance. Therefore, we need to encourage liver donation from living-related donors.

Liver transplantation for patients with hepatocellular carcinoma.

BACKGROUND: Liver transplantation (LT) has been advocated as a salvage treatment for unresectable hepatocellular carcinoma (HCC). Selection criteria still need to be developed in Taiwan. OBJECTIVES: The purpose of our study was to assess the clinical findings and outcome of cirrhotic patients with HCC undergoing liver transplantation. METHODS: Our study consisted of 13 HCC patients who underwent liver transplantation during October 1996 to March 2003. The medical records and pathologic reports were analyzed retrospectively. RESULTS: Overall survival rates at 1 and 3 years were 86% and 61%, respectively. HCC recurrences occurred in three patients, one of whom is still alive with HCC recurrence 2 years after LT. The other two patients died of HCC recurrence 1 and 2 years after LT, respectively. Pretransplant alpha-fetoprotein (AFP) levels of >200 ng/mL were noted in all three patients with HCC recurrence. In contrast, only one of the ten patients without HCC recurrence had pretransplant AFP >200 ng/mL (P = .003). Four patients did not meet Milan criteria, two of whom had HCC recurrence. However, the other two patients with microscopic vascular invasion survived and were free of HCC. The only one patient, who had histologic grade 4 HCC, died of recurrence, although his tumor was AJCC stage 1. CONCLUSIONS: High AFP level is a risk factor for HCC recurrence after LT. In addition to Milan criteria, histologic tumor grading should be considered in patient selection. Microscopic vascular invasion may not affect the outcome of the patients with early HCC.

Surgical complications and outcome of living related liver transplantation.

INTRODUCTION: Living donor liver transplantation (LDLT) is now widely performed for patients to resolve the critical shortage of organs from cadavers. Despite rapid implementation and expansion of the procedure, both outcome and complication analyses of LDLT are still incomplete. OBJECTIVES: To analyze the outcome of LDLT, with particular reference to complications of those in need of surgical or radiological intervention. METHODS: Forty-eight LDLTs performed at National Taiwan University Hospital between December 1997 and April 2003 were reviewed retrospectively. RESULTS: Forty-two (87.5%) patients survived the operation. The 1-year graft and patient survival rate was 81.5%. Seventeen of the 48 LDLT patients had at least one postoperative complication, which needed surgical or radiological intervention. The complications included bile leakage (n = 3), biliary stricture (n = 4), internal bleeding (n = 7), intra-abdominal abscess (n = 2), liver abscess (n = 1), hepatic artery thrombosis (n = 2), duodenal ulcer bleeding (n = 1), jejunal perforation (n = 1), adhesion ileus (n = 1), and intracranial hemorrhage (n = 1). Nine of the 17 patients with complications died. In contrast, only 2 of the other 31 patients died. Seven of the mortalities were related to the complications. All survivors received only one definite intervention early after the complications were diagnosed. However, the others received an average of 1.71 +/- 0.95 (0 to 3) interventions. CONCLUSIONS: Complications requiring surgical or radiological treatment caused major mortality of LDLT. Early and definite treatment of these complications is important to improve the patient's outcome.

Hepatic portal vein gas following blunt colon injury: report of a case.

Blunt colon injuries sometimes result in signs of peritoneal irritation requiring exploratory laparotomy. More frequently there are no specific symptoms, and this leads to a delay in diagnosis and management. Some imaging studies point to blunt colon injury, but gas in both the hepatic portal and mesenteric veins has rarely been reported. Hepatic portal venous gas (HPVG) is a rare roentgenographic picture, and its presence usually represents a serious intra-abdominal catastrophe. Computed tomography and plain abdominal X ray in a 52-year-old man with blunt abdominal injury showed significant gas in the portal venous system and pneumatosis intestinales of the ascending colon. Exploratory laparotomy revealed segmental necrosis of the transverse colon in front of the vertebrae. The presence of HPVG may have been due to mucosal disruption, vascular compromise or prolonged increased intra-abdominal pressure. Its presence in patients with blunt abdominal trauma suggests the possibility of bowel injury. Surgical exploration should be considered when HPVG is noted on roentgenographic studies.

Managing older patients with urinary retention in the Continence Clinic.

OBJECTIVE: To evaluate the effectiveness of the Continence Clinic for managing retention of urine in older patients. DESIGN: Retrospective study. SETTING: Continence Clinic, Fung Yiu King Hospital, Hong Kong. SUBJECTS AND METHODS: Case notes of 58 patients seen at the Fung Yiu King Hospital Continence Clinic from October 1997 to September 2001 were reviewed. The patients had retention of urine with post-void residual volume of more than 200 mL, retention of urine requiring catheterization, or had catheters for unknown reasons. RESULTS: Urodynamic study performed for 22 (38%) patients showed that 12 had detrusor underactivity, six had detrusor hyperactivity with impaired contraction, and four had bladder outlet obstruction. Among the patients who were initially catheterized, the success rate for gradually stopping reliance on urinary catheterization was 84%. The success rate was higher among those who did not undergo urodynamic study than among those who had the study done (95% versus 67%; P=0.03). Reduction in post-void residual volume was observed at the last clinic visits (P<0.0001). Moreover, significant decreases in post-void residual volume were found both for patients who did and did not have urodynamic study. CONCLUSION: Most of the older patients with urinary retention with or without indwelling catheters were treated successfully in the Continence Clinic by appropriate medical therapy. Urodynamic study can be performed for selected patients when managing urinary retention.

Sequence analysis of the Aspergillus nidulans pectate lyase pelA gene and evidence for binding of promoter regions to CREA, a regulator of carbon catabolite repression.

The nucleic acid and deduced amino-acid sequences of the pectate lyase gene (pelA) from Aspergillus nidulans are presented. The pelA gene contains two short introns, 68 and 49 bp in length, and encodes a peptide of 326 amino acids. Five transcriptional start sites are clustered between 65 and 79 bp upstream of the start codon as determined by primer extension. Comparison of the amino-acid sequences of pectate or pectin lyases from bacteria, fungi and plants revealed less than 30% overall identity. However, five regions within these enzymes, in particular domains associated with the active site, are highly conserved with amino-acid similarities greater than 50%. Phylogenetic analysis using the principle of parsimony (PAUP 3.1.1) showed that pelA is most closely related to pectate lyases from plants rather than pectin lyases from other fungi. Previously, pelA was shown to be induced by polygalacturonic acid and repressed in the presence of preferred carbon sources, such as glucose. Gel mobility shift analysis indicates that a PstI-SphI fragment from the pelA promoter binds to a fusion protein composed of the N-terminal part of CREA, a protein involved in carbon catabolite repression, and glutathione-S-transferase. This result suggests CREA may contribute to the regulation of pelA expression.

Kinetics of proteolysis of hog gastric mucin by human neutrophil elastase and by Pseudomonas aeruginosa elastase.

Human neutrophil and Pseudomonas aeruginosa elastases were compared for their ability to degrade hog gastric mucin, which was used as a model substrate. P. aeruginosa elastase was more active than neutrophil elastase, and 2 to 10 peptide bonds were hydrolyzed within 5 min. The results demonstrate that both elastases degrade mucins actively at concentrations comparable to physiological levels of neutrophil elastase, which raises the possibility that proteolysis of mucins may be one mechanism of damage during chronic infection and inflammation of the respiratory tract.

92% pump depletion in a continuous-wave one-pump fiber optical parametric amplifier.

Theory shows that near-complete pump depletion can be obtained in uniform fiber-optic parametric amplifiers (OPA's) for a particular phase-matching condition. We have demonstrated 92% pump depletion in a cw fiber OPA, with a 200-mW pump at 1560 nm in an 11-km-long dispersion-shifted fiber.

Endothelin-1 protects astrocytes from hypoxic/ischemic injury.

Under pathological conditions such as ischemia (I), subarachnoid hemorrhage, and Alzheimer's disease, astrocytes show a large increase in endothelin (ET) -like immunoreactivity. However, it is not clear whether ET is protective or destructive to these cells during brain injury. Using astrocytes from ET-1-deficient mice, we determined the effect of ET-1 on these cells under normal, hypoxic (H), and hypoxic/ischemic (H/I) conditions. Under normal culture conditions, astrocytes from wild-type and ET-1-deficient mice showed no difference in their morphology and cell proliferation rates. ET-3 and ETA receptor mRNAs were up-regulated whereas ETB receptor mRNA was down-regulated in ET-1-deficient astrocytes, suggesting that ET-1 and ET-3 may complement each other's functions and that the expressions of these endothelins and their receptors are regulated by a complex feedback mechanism. Under H and H/I conditions, ET-1 peptide and mRNA were up-regulated in wild-type astrocytes, and the astrocytes without ET-1 died faster than the wild-type astrocytes, as indicated by greater efflux of lactate dehydrogenase. The present study suggests that astrocytes without ET-1 are more vulnerable to H and H/I injuries and that the up-regulation of astrocytic ET-1 is essential for the survival of astrocytes.

Thermodynamic characterization of the human acidic fibroblast growth factor: evidence for cold denaturation.

The thermodynamic parameters characterizing the conformational stability of the human acidic fibroblast growth factor (hFGF-1) have been determined by isothermal urea denaturation and thermal denaturation at fixed concentrations of urea using fluorescence and far-UV CD circular dichroism (CD) spectroscopy. The equilibrium unfolding transitions at pH 7.0 are adequately described by a two-state (native <--> unfolded state) mechanism. The stability of the protein is pH-dependent, and the protein unfolds completely below pH 3.0 (at 25 degrees C). hFGF-1 is shown to undergo a two-state transition only in a narrow pH range (pH 7.0-8.0). Under acidic (pH <6.0) and basic (pH >8.0) conditions, hFGF-1 is found to unfold noncooperatively, involving the accumulation of intermediates. The average temperature of maximum stability is determined to be 295.2 K. The heat capacity change (DeltaC(p)()) for the unfolding of hFGF-1 is estimated to be 2.1 +/- 0.5 kcal.mol(-1).K(-1). Temperature denaturation experiments in the absence and presence of urea show that hFGF-1 has a tendency to undergo cold denaturation. Two-dimensional (1)H-(15)N HSQC spectra of hFGF-1 acquired at subzero temperatures clearly show that hFGF-1 unfolds under low-temperature conditions. The significance of the noncooperative unfolding under acidic conditions and the cold denaturation process observed in hFGF-1 are discussed in detail.

Induction of steady-state blood alcohol levels: application to the study of within-session alcohol tolerance in rats.

BACKGROUND: The study of within-session alcohol tolerance in the rat has been hampered by methodological difficulties related to the measurement of dependent variables at predictable blood alcohol concentrations (BAC) during a single session of alcohol exposure. This study characterizes a method for maintaining steady-state blood alcohol levels over several hours in the rat, referred to as the "alcohol clamp." METHODS: Wistar rats were implanted with an indwelling catheter in the carotid artery for blood sampling and another in the external jugular vein for alcohol infusion. To clamp BAC at a predetermined level, rats first were infused with a priming dose of alcohol to establish the desired or "target" BAC, followed by a continuous infusion of alcohol at a rate equal to that of alcohol metabolism in the rat. This maintained BAC at a constant level over time. BACs of 100, 200, or 300 mg% were maintained over several hours in separate groups of rats. The alcohol clamp was applied to the study of acute (within-session) alcohol tolerance in rats selectively bred for high and low alcohol drinking. Alcohol-induced hypothermia was used to index tolerance, and within-session alcohol tolerance was defined as a return of body temperature toward baseline during the course of the alcohol infusion while BAC was maintained at a constant level. RESULTS: The continuous alcohol infusion procedure maintained BAC in a steady state throughout the 3 hr alcohol infusion session at each of the three target BAC levels. Alcohol infusion induced a drop in body temperature, followed by a return of temperature toward baseline during the course of infusion, which indicated the development of within-session alcohol tolerance. CONCLUSIONS: The continuous alcohol infusion procedure (alcohol clamp) maintained BAC in a steady state, both within and between subjects, across a wide range of blood alcohol levels. The alcohol clamp appears to be a useful tool for subsequent studies of within-session alcohol tolerance in the rat.