Biomedical subjects

Xi-Zhang Lin

Publications and source records attributed to Xi-Zhang Lin.

15 recordsLinked to original sources

PubMed2006

No debridement is necessary for symptomatic or infected acute necrotizing pancreatitis: delayed, mini-retroperitoneal drainage for acute necrotizing pancreatitis without debridement and irrigation.

We sought to determine if necrosectomy can be omitted for complicated acute necrotizing pancreatitis (ANP). Since 1996, we prospectively performed retroperitoneal drainage by introducing a sump drain to the pancreatic head area via a small left flank incision without debridement and irrigation on 19 consecutive complicated ANP patients. We purposely delayed surgery until liquefaction of retroperitoneal tissue reached the left flank. Our patients had a mean Ranson's and APACHE II score of 5.9 (range, 4-8) and 20.1(range, 4-45), respectively. Sixteen available CT showed retroperitoneal liquefaction after 21.3 days (range, 14-26). Operations were delayed for 4.7 weeks (range, 1.3-9.0). No patient succumbed during this period. The indications were infected necrosis in 16 and severe abdominal pain/food intolerance in 3 patients. Average skin incision was 4.0 cm (range, 3-9). Fungi or bacteria were cultured in 15 patients (80.0%). The recovery courses were surprisingly uneventful. Oral intake began within 2.4 days (range, 1-5) and mean hospital stay (16 survivals) was 23.2 days (range, 4-120) after operation. Drains were completely removed 120.6 days (range, 60-250) later from these outpatients. One gastric perforation and one minor duodenal leak were the only procedure-related complications (10.5%). Three patients died (15.8%), although one had a healed ANP. In conclusion, this delay-until-liquefaction strategy without necrosectomy is an easy and effective treatment method.

Aged, 80 and over↗

PubMed2006

Ionic effect on the binding of bilirubin to the imprinted poly(methacrylic acid-co-ethylene glycol dimethylacrylate).

A molecularly imprinted polymer (MIP) capable of detecting bilirubin was successfully synthesized. Bilirubin template was imprinted in poly(methacrylic acid-co-ethylene glycol dimethylacrylate) [poly(MAA-co-EGDMA)]. MAA and EGDMA were used as the monomer and the cross-linker, respectively. The optimal solvent conditions to maintain its stability were discussed. Solvent system based on ethylenediamine tetraacetic acid (EDTA) and ascorbic acid was compared with respect to the stability of bilirubin. pH and bilirubin concentration were both investigated for the bilirubin stability. Blue light as well as aeration was applied to inspect the regarding effects. The cross-linking effect was further confirmed by the thermogravimetric analysis (TGA). The effect of salts, such as NaCl and KCl on the binding capacity of the molecularly imprinted polymer was also discussed. Further, the rat serum and bile samples were applied and the binding of the MIPs for bilirubin was thus confirmed.

Adsorption↗

PubMed2006

Determination of C-reactive protein with an ultra-sensitivity immunochemiluminometric assay.

C-reactive protein (CRP), the classic acute phase reactant, is strongly associated with increased risk of cardiovascular events. The demand for measuring serum CRP levels has been predicted to increase. We developed an ultra-sensitivity in-house immunometric assay on polystyrene beads for measuring CRP and studied its analytical and clinical performance. The assay used a pair of monoclonal anti-CRP antibodies and detected CRP in a 1-step immunometric assay with a chemiluminescence signal. The calibration was traceable to the World Health Organization reference material. The assay covered a linear range of 0.01 to 50.00 mg/L. The analytical detection limit calculated from the mean level plus 3 SD of the zero calibrator was 0.004 mg/L. The within-run imprecision was 7.0%, 5.2%, and 4.1% for mean CRP levels of 0.02 mg/L, 1.44 mg/L, and 11.04 mg/L, respectively. The between-run imprecision was 9.2%, 7.0%, and 6.0% for mean CRP levels of 0.02 mg/L, 1.49 mg/L, and 10.90 mg/L, respectively. The average recovery was 102.0% (n=6). The assay correlated well with a high-sensitivity latex-enhanced nephelometric assay (regression line y=0.865 x +1.333, r=0.974, S(y/x)=3.415, n=47 for 0-50.00 mg/L and y=1.076 x-0.080, r=0.985, S(y/x)=0.989, n=29 for 0-20.00 mg/L). The central 95 percentile reference interval for Han Chinese residing in Taiwan was 0.02-4.33 mg/L (n=469). There was no significant difference in serum CRP levels between healthy male and female subjects (median, 0.34 and 0.31 mg/L, respectively); however, CRP levels increased moderately with age (r=0.276, P<.05). The reference values for the Chinese population were about 5-fold lower than those for the United States population. This ultra-sensitivity immunochemiluminometric assay for CRP is rapid and accurate and can be used to assess cardiovascular risk.

Adolescent↗

PubMed2006

Clinical analysis of the predictive factors for recurrent appendicitis after initial nonoperative treatment of perforated appendicitis.

BACKGROUND: The purpose of this study was to study the clinical symptoms, laboratory data, and the characteristics of computed tomography (CT) imaging of nonoperated perforated appendicitis for predicting the recurrence of appendicitis. METHODS: Thirty-five patients with nonoperated perforated appendicitis were retrospectively reviewed for this study. During a median follow-up period of 1155 days, 7 patients had to receive an appendectomy owing to recurrent appendicitis. Accordingly, the patients were divided into 2 groups: the recurrence and the nonrecurrence group. The clinical characteristics between these 2 groups were compared. RESULTS: Both of the 2 patients who had a past history of appendicitis suffered recurrent appendicitis (the recurrence versus the nonrecurrence group, P<.05). The only CT imaging relating to the recurrence of appendicitis is the presence of calcified appendicolith (the recurrence versus the nonrecurrence group, P<.001). CONCLUSIONS: It is most likely that appendicitis will recur if a calcified appendicolith on CT imaging or a past history of appendicitis is presented. Interval appendectomy may be reserved only for those patients who possess one of these risk factors of recurrent appendicitis.

Adult↗

PubMed2006

Characterization of serum-free ex vivo-expanded hematopoietic stem cells derived from human umbilical cord blood CD133(+) cells.

The development of ex vivo expansion of hematopoietic stem cells (HSCs) is a promising approach to restore the required bone marrow function of patients with hematological disorders. Previously, we have reported the development of an optimized serum-free and cytokines-limited defined medium using statistic methodology for umbilical cord blood-derived HSC expansion. The aim of this study was to analyze further the characteristics and functions of cells in vitro and in vivo when cultured in this defined medium. After a 7-day batch culture, the average absolute fold expansions for CD133(+) cells, CD34(+)CD133(+) cells, CD34(+)CD38() cells, CD133(+)CD38(-) cells, CD34(+)CXCR4(+) cells, CD133(+)CXCR4(+) cells, and long-term culture-initiating cells were 21-, 20-, 723-, 618-, 160-, 384-, and 8-fold, respectively. The high enrichment of CD38(-) cells and CXCR4(+) cells of the CD34(+) subpopulation provided a very early uncommitted HSC proliferation and homing ability. Furthermore, the expanded cells showed a high level of telomerase activity to maintain their telomere length and repopulated the lethally irradiated NOD/SCID mice in vivo. These results indicated that the cytokines limited expanded cells from CD133(+) cells could substantially support simultaneous expansion of various stem/progenitor cells and engraft with the expanded cells from a low number of HSCs initially.

AC133 Antigen↗

PubMed2006

Simplified hepatic resections with the use of a Chang's needle.

OBJECTIVE: To demonstrate the use of Chang's needle for hepatic resections. SUMMARY BACKGROUND DATA: Specialized instruments, fine surgical skills, and good control of hepatic inflow and backflow are essential for hepatic resections. This needle was specifically designed to simplify these requirements. METHODS: Whole-thickness interlocking sutures of the liver can first be made along the designed resection line with a Chang's needle; then parenchyma transection can follow without inflow or backflow control. This was consecutively performed on 69 patients with primary (41), metastatic (10), and benign (18) diseases since 1997. RESULTS: Blood loss during parenchyma transection was reduced in 11 right lobectomies (652 mL), 1 3-segmentectomy (300 mL), 14 bisegmentectomies (252 mL), 7 segmentectomies (104 mL), 12 subsegmentectomies (19 mL), 5 wedge resections (7 mL), 18 left lateral segmentectomies (110 mL), and 1 hepatorrhaphy (minimal). There was no procedure-related mortality. A mild bile leakage occurred in 1 case (1.5%) but healed spontaneously. CONCLUSIONS: The preliminary results demonstrate that this maneuver is a simple, easy, and safe method for performing hepatic resections.

Blood Loss, Surgical↗

PubMed2005

Thermogelling emulsions for vascular embolization and sustained release of drugs.

Thermogelling emulsion system was developed to function as an embolic agent and sustained release system. PEG-PLGA-PEG triblock copolymer was synthesized, and blended with oily phase (Lipiodol(R)) to constitute the thermogelling emulsions. Because the polymer-rich aqueous phase dramatically increases viscosity in response to temperature change, especially within the range between 20 and 30 degrees C, the emulsions produce a stop-flowing gel with oil droplets entrapped. Thereafter, paclitaxels were released from the oily reservoir of gelled emulsions in a controlled manner. Reduced burst effect and steady drug release with near zero-order release kinetics were observed. Human umbilical vein endothelial cells (HUVEC) were collected from fresh umbilical cords for in vitro antiangiogenesis test. It demonstrated that the sustained release of paclitaxel from emulsions inhibited growth of HUVEC and that the IC(50), calculated according to release rate, was consistent with that obtained from free drug study. In addition, the emulsions forming a depot in situ inside the injection site of the blood vessel in rabbit ear obstructed the blood flow, and being monitored under X-ray angiography. Taken together, this study proved the feasibility of the thermogelling emulsions for vascular embolization and sustained drug release. The results presented a potential system for arterial transcatheter embolization on hepatocellular carcinoma combined with anti-angiogeneic treatment.

Animals↗

PubMed2005

The value of biliary amylase and Hepatocarcinoma-Intestine-Pancreas/Pancreatitis-associated Protein I (HIP/PAP-I) in diagnosing biliary malignancies.

BACKGROUND/OBJECTIVES: Elevated concentrations of Hepatocarcinoma-Intestine-Pancreas/Pancreatitis-associated Protein I (HIP/PAP-I) in pancreatic juice have been reported in patients with pancreatic adenocarcinoma and have been considered as a promising tumor marker. This study was conducted to investigate whether biliary HIP/PAP-I can be used in the differential diagnosis of the cause of biliary obstruction. METHODS: Bile was obtained from patients with bile duct obstruction on the day of biliary drainage. The etiology of biliary obstruction included gallstones (n = 131), pancreatic cancer (n = 32), cholangiocarcinoma (n = 47), papilla Vater cancer (n = 13), hepatocellular carcinoma (n = 4) and metastatic cancer (n = 16). In addition to HIP/PAP-I, the samples were analyzed for amylase to check for the presence of pancreaticobiliary reflux. RESULTS: The biliary concentration of HIP/PAP-I was not statistically different between patients with gallstones (median, 9.70 ng/mL; interquartile range [IQR] 1.80-45.75) and cancers (median, 12.70 ng/mL; IQR, 3.85-36.75), P > 0.05. However, the amylase activity in the bile was markedly elevated in patients with gallstones (median, 228 U/L; IQR, 40-1965), compared to those with cancer (median, 32 U/L; IQR; 30-176), P < 0.001. The area under the ROC curve of amylase was 0.751 (95% CI: 0.69 to 0.81). At a cut-off value of 46 U/L, the biliary amylase distinguished patients with malignant obstruction from those with benign obstruction with a sensitivity of 66% and a specificity of 74%. CONCLUSIONS: Our data suggest that the biliary HIP/PAP-I measurement is not useful for differentiating causes of biliary obstruction. The divergent extent and duration of biliary obstruction caused by neoplasm and gallstones may contribute to the significant difference in the amylase activity in bile. Thus, amylase in bile represents a candidate marker in the differential diagnosis of the cause of biliary obstruction.

Amylases↗

PubMed2004

Amperometric detection of morphine at a Prussian blue-modified indium tin oxide electrode.

In this work, the electrocatalytic oxidation of morphine (MO) at an optically transparent indium tin oxide (ITO) electrode modified by an electrodeposited Prussian blue (PB) thin film is first demonstrated, and the amperometric detection of MO was then investigated. Experimental results showed that the thin film on the ITO surface, confined to the PB/Berlin green (BG) redox pair, can serve as an excellent mediator which facilitates electron transfer and considerably lowers the overpotential required, as compared to a bare ITO electrode. Thus, PB can be regarded as a promising artificial peroxidase for MO. The rate of such an electrocatalytic reaction is pH dependent with the highest value at pH 5. By potential-step excitation from 0.55 to 0.70 V, a linear calibration curve, displaying the relationship between steady-state currents and MO concentrations (ranging from 0.09 to 1.0 mM), was obtained. The detection sensitivity is about 16.8 microA/cm2 mM. Most importantly, the method described herein can readily discriminate MO analogs lacking the phenolic -OH group, such as codeine, and can thus benefit the specific recognition of MO.

Biosensing Techniques↗

PubMed2004

MRI of gallstones with different compositions.

OBJECTIVE: Gallstones are usually recognized on MRI as filling defects of hypointensity. However, they sometimes may appear as hyperintensities on T1-weighted imaging. This study investigated how gallstones appear on MRI and how their appearance influences the detection of gallstones. MATERIALS AND METHODS: Gallstones from 24 patients who had MRI performed before the removal of the gallstones were collected for study. The gallstones were classified either as cholesterol gallstone (n = 4) or as pigment gallstone (n = 20) according to their gross appearance and based on analysis by Fourier transform infrared spectroscopy. MRI included three sequences: single-shot fast spin-echo T2-weighted imaging, 3D fast spoiled gradient-echo T1-weighted imaging, and in-phase fast spoiled gradient-echo T1-weighted imaging. The signal intensity and the detection rate of gallstones on MRI were further correlated with the character of the gallstones. RESULTS: On T1-weighted 3D fast spoiled gradient-echo images, most of the pigment gallstones (18/20) were hyperintense and all the cholesterol gallstones (4/4) were hypointense. The mean ratio of the signal intensity of gallstone to bile was (+/- standard deviation) 3.36 +/- 1.88 for pigment gallstone and 0.24 +/- 0.10 for cholesterol gallstone on the 3D fast spoiled gradient-echo sequence (p < 0.001). Combining the 3D fast spoiled gradient-echo and single-shot fast spin-echo sequences achieved the highest gallstone detection rate (96.4%). CONCLUSION: Based on the differences of signal intensity of gallstones, the 3D fast spoiled gradient-echo T1-weighted imaging was able to diagnose the composition of gallstones. Adding the 3D fast spoiled gradient-echo imaging to the single-shot fast spin-echo T2-weighted sequence can further improve the detection rate of gallstones.

Adult↗

PubMedDate not supplied

Texture feature coding method for classification of liver sonography.

This paper introduces a new texture analysis method called texture feature coding method (TFCM) for classification of ultrasonic liver images. The TFCM transforms a gray-level image into a feature image in which each pixel is represented by a texture feature number (TFN) coded by TFCM. The TFNs obtained are used to generate a TFN histogram and a TFN co-occurrence matrix (CM), which produces texture feature descriptors for classification. Four conventional texture analysis methods that are gray-level CM, texture spectrum, statistical feature matrix and fractal dimension, are used also to classify liver sonography for comparison. The supervised maximum likelihood (ML) classifiers implemented by different type texture features are applied to discriminate ultrasonic liver images into three disease states that are normal liver, liver hepatitis and cirrhosis. The 30 liver sample images proven by needle biopsy are used to train the ML system that classify on a set of 90 test sample images. Experimental results show that the ML classifier together with TFCM texture features outperforms one with the four conventional methods with respect to classification accuracy.

Fractals↗

PubMedDate not supplied

Computed tomography demonstration of immediate and delayed complications of computed tomography-guided transthoracic percutaneous ethanol injection of hepatocellular carcinoma at the liver dome.

OBJECTIVE: We conducted this study to correlate computed tomography (CT) images with the complications induced by CT-guided percutaneous ethanol injection (PEI) for the treatment of hepatocellular carcinoma (HCC). METHODS: Twenty-two patients with ultrasonographically unreachable HCC were treated with CT-guided transthoracic PEI. The procedures and the CT findings were recorded to correlate with the various complications of PEI. RESULTS: After the ethanol injection, 3 patterns of CT images were identified according to the distribution of ethanol (ie, intratumoral, extrahepatic, and intrahepatic patterns). The intrahepatic pattern was further classified as the branch, tubular, and infiltrative types. During the follow-up period, 3 patients developed biliary stricture, portal vein thrombosis, or tumor seeding. The tubular type was associated with the development of biliary stricture, whereas the branch type was related to the occurrence of portal vein thrombosis. These complications were considered to be caused by a greater amount of ethanol leakage into bile ducts or portal veins than in cases without complications (median = 17 mL vs. 0 mL, P = 0.002). CONCLUSIONS: Ethanol leakage is not uncommon when performing PEI; however, it seems to be safe when the leakage is less than 15 mL. Injection of a small amount of ethanol or monitoring by CT may be helpful in preventing the development of these complications.

Administration, Cutaneous↗

PubMedDate not supplied

The assessment of biliary CA 125, CA 19-9 and CEA in diagnosing cholangiocarcinoma--the influence of sampling time and hepatolithiasis.

BACKGROUND/AIMS: This study was conducted to assess the clinical value of biliary CA 19-9, CA 125 and CEA sampled in different situations for the diagnosis of cholangiocarcinoma. METHODOLOGY: Bile was obtained from patients with bile duct obstruction on the day of biliary drainage and 3 days later separately. The etiology of biliary obstruction included choledocholithiasis (N = 51), hepatolithiasis (N = 19) and cholangiocarcinoma (N = 28). Patients of the former two conditions were all complicated with cholangitis. RESULTS: The sensitivity of biliary CEA, CA 19-9 and CA 125, whenever checked were all less than 70%. The biliary CEA and CA 19-9 were elevated in the presence of cholangitis. In addition, the biliary CEA was also increased in the patients with hepatolithiasis. The specificity of CA 125 was better than those of CEA and CA 19-9 (75.7% vs. 33.3% and 60%, respectively) on the day of biliary drainage. The diagnostic efficiency was slightly improved when combining biliary CA 125 and CEA. CONCLUSIONS: As the biliary CA 125 was less affected by inflammation and hepatolithiasis, it is more useful than CEA and CA 19-9 in the diagnosis of cholangiocarcinoma. The single tumor marker test of CA 125 or combined tumor marker test of CEA and CA 125 may be used as a useful complement to other investigative methods to differentiate benign from malignant causes of the bile duct obstruction.

Aged↗

PubMedDate not supplied

The value of biliary fibronectin for diagnosis of cholangiocarcinoma.

BACKGROUND/AIMS: The fibronectin in various body fluids was reported to be useful in the differential diagnosis of benign and malignant diseases. We conducted this study to assess the diagnostic value of biliary fibronectin. METHODOLOGY: Bile was collected from patients with gallstones (n = 62), benign biliary stricture (n = 5) and cholangiocarcinoma (n = 28). All patients with gallstones were complicated with cholangitis. The absolute biliary level of fibronectin was determined by an immunoenzymatric assay and divided by the biliary concentration of bile acids to calculate the relative concentration. RESULTS: The relative concentration of biliary fibronectin was significantly different among the patients with benign biliary obstruction, gallstone and cholangiocarcinoma (7.1 +/- 14.3 vs. 350.5 +/- 1535.4 vs. 180592.6 +/- 917236.2, p < 0.05). With a cut-off value of 40 ng/mumol, its sensitivity for diagnosing cholangiocarcinoma was 0.57, and specificity, 0.79. CONCLUSIONS: As bile may be concentrated or diluted to a various extent after biliary obstruction, the relative concentration of biliary fibronectin is more useful than the absolute concentration in differentiating the causes of biliary obstruction. In addition to the presence of biliary cancer, biliary fibronectin was also increased in response to biliary inflammation, which limits its use as a tumor marker of cholangiocarcinoma.

Aged↗

PubMedDate not supplied

Hydrodynamics-based gene delivery to the liver by bile duct injection of plasmid DNA--the impact of lasting biliary obstruction and injection volume.

BACKGROUND/AIMS: Increased biliary pressure may mediate an opening of intrahepatic tight junctions. The biliary pressure is related to the duration of biliary obstruction and the injected volume. Their effects on the efficiency of gene delivery to the liver were studied. METHODOLOGY: The luciferase gene with a volume of 0.5, 1.0, 1.5 or 2.0mL was injected into the bile duct of Sprague-Dawley rats. After the injection, the bile ducts were occluded in some of the rats, while left to drain in the others. RESULTS: The activity of luciferase was the highest in rats that received 2.0mL of DNA injection and biliary occlusion, while the lowest in the rats that received 0.5mL of DNA only. CONCLUSIONS: The bile duct can be an efficient route for gene delivery to the liver depending on the volume of injected DNA. Biliary occlusion can enhance the expression of genes but it may induce a certain degree of liver injury, which should be taken into concern.

Animals↗