Selection of best impregnated palm shell activated carbon (PSAC) for simultaneous removal of SO2 and NOx

This work examines the impregnated carbon-based sorbents for simultaneous removal of SO(2) and NOx from simulated flue gas. The carbon-based sorbents were prepared using palm shell activated carbon (PSAC) impregnated with several metal oxides (Ni, V, Fe and Ce). The removal of SO(2) and NOx from the simulated flue gas was investigated in a fixed-bed reactor. The results showed that PSAC impregnated with CeO(2) (PSAC-Ce) reported the highest sorption capacity among other impregnated metal oxides for the simultaneous removal of SO(2) and NOx. PSAC-Ce showed the longest breakthrough time of 165 and 115 min for SO(2) and NOx, respectively. The properties of the pure and impregnated PSAC were analyzed by BET, FTIR and XRF. The physical-chemical features of the PSAC-Ce sorbent indicated a catalytic activity in both the sorption of SO(2) and NOx. The formation of both sulfate (SO(4)(2-)) and nitrate (NO(3-)) species on spent PSAC-Ce further prove the catalytic role played by CeO(2).

Experience with hookwire localisation excision biopsy at a medical centre in Malaysia

INTRODUCTION

With an increasing number of women undergoing breast screening, an effective method of removing non-palpable lumps detected by mammography or sonography is by hookwire localisation excision biopsy (HWLB). The aim of this paper was to audit the practice of HWLB at the University Malaya Medical Centre.

METHODS

Patients with benign or suspicious preoperative diagnoses of a non-palpable lump and who underwent HWLB were included in this study. Pathological examination of the surgical specimens was conducted and a correlation with preoperative assessment modalities was reported.

RESULTS

A total of 59 HWLBs were carried out in 57 female patients. The mean age of the patients was 51.5 years. The overall malignancy rate was 32.3 percent (19 out of 59 cases) with a benign to malignant ratio of 3.1 to 1. Ten of these cases were ductal carcinoma-in-situ. Out of 25 patients who were suspicious on preoperative assessment, 16 malignancies were found, while in the 33 patients thought to be benign on preoperative assessment, there were three malignancies, giving a sensitivity of 84.2 percent and a specificity of 76.9 percent (p is less than 0.05). The mean tissue volume excised in 53 available records was 50.0 cm(3), with pathological tissue comprising only 15.4 percent of the total excised volume. Clear margins were obtained in 42.1 percent of the patients. The overall operative complication rate was 10.2 percent.

CONCLUSION

Malignancy was reported in one third of women undergoing HWLB, of which 16 had suspicious features on radiological assessment and/or fine needle aspiration cytology/core needle biopsy preoperatively. Non-palpable lumps should be excised by HWLB for a definitive diagnosis in case of any suspicion on preoperative assessment, as the prognosis is excellent.

Reporting 678 putative cSNPs from full-length enriched cDNA sequences of the Korean native pig

Sequences from the clones of full-length enriched cDNA libraries serve as valuable resources for functional genomic studies. We have analysed 1970 high-quality chromatograms (Phred value >or= 30) that were obtained from sequencing the 5' ends of brainstem, liver, neocortex and spleen clones derived from full-length enriched cDNA libraries from Korean native pigs. In addition, 50,000 pig expressed sequence tag (EST) sequence trace files were obtained from Genbank and combined with our sequencing information to facilitate SNP identification in silico. The process generated 8118 contigs, of which 239 included minimum one sequence from Korean native pig and contained 678 putative coding single nucleotide polymorphisms (cSNPs). Of these, 33 putative cSNPs were randomly selected for confirmatory analysis and validated using 20 pigs from four different breeds (Duroc, Landrace, Yorkshire, Korean native pig). Of the 33 putative cSNPs, 20 were confirmed (61%), which was similar to the frequency reported in other studies. We also identified 15 new cSNPs from the validation process, which were not detected by our in silico analysis. Our study shows that analysing genetically diverse pig breeds including the Korean native pig could serve as a useful strategy for generating a large number of cSNPs.

How do we interpret an elevated carbohydrate antigen 19-9 level in asymptomatic subjects?

AIM

This prospective cohort study aimed to evaluate the etiology of elevated CA 19-9 levels and to present appropriate guidelines for the asymptomatic patients.

METHODS

Between January 2004 and March 2007, we enrolled consecutive asymptomatic patients who had elevated CA 19-9 levels >37 U/mL. To evaluate the etiology, the CA 19-9 level was rechecked and further studies were carried out. If the CA 19-9 level decreased to the normal range, or if it showed a decreasing trend, then it was monitored annually. Yet, if the CA 19-9 level showed an increasing trend, then the level was monitored at intervals of 1, 3, and 6 months until no evidence of malignancy was proven.

RESULTS

Of the 62,976 patients, 501 (0.8%) subjects showed an elevated CA 19-9 level. This prospective analysis was conducted on 353 subjects (70.5%) who were followed up for at least 6 months. Ten patients (2.8%) were diagnosed with malignancies. There were 97 patients (27.5%) with benign diseases and 246 patients (69.7%) were deemed non-specific.

CONCLUSIONS

CA 19-9 should not be used as a screening tool. In the case of a persistently elevated CA 19-9 level, further work-up for determining the etiology should be done.

Optimization of microporous palm shell activated carbon production for flue gas desulphurization: experimental and statistical studies

Optimizing the production of microporous activated carbon from waste palm shell was done by applying experimental design methodology. The product, palm shell activated carbon was tested for removal of SO2 gas from flue gas. The activated carbon production was mathematically described as a function of parameters such as flow rate, activation time and activation temperature of carbonization. These parameters were modeled using response surface methodology. The experiments were carried out as a central composite design consisting of 32 experiments. Quadratic models were developed for surface area, total pore volume, and microporosity in term of micropore fraction. The models were used to obtain the optimum process condition for the production of microporous palm shell activated carbon useful for SO2 removal. The optimized palm shell activated carbon with surface area of 973 m(2)/g, total pore volume of 0.78 cc/g and micropore fraction of 70.5% showed an excellent agreement with the amount predicted by the statistical analysis. Palm shell activated carbon with higher surface area and microporosity fraction showed good adsorption affinity for SO2 removal.

Effects of cyclosporine on the production of the reactive oxygen species in the glial cells

OBJECTIVES

After organ transplantation, some patients suffer mild neurological symptoms such as tremor to severe complications including seizures and encephalopathy. Among the immunosuppressants, cyclosporine (CsA) can induce neurological side effects. However, the mechanisms of encephalopathy by CsA are not fully understood. We measured the production of reactive oxygen species (ROS) in the glioma cells after CsA treatment.

METHODS

CsA (2.5 mmol/L) added to glioma cells was incubated for 60 minutes at 37 degrees C. ROS production was evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2',7'-dichlorofluorescin using VICTOR3 multilabel counter.

RESULTS

CsA resulted in ROS production by glioma cells. The ROS production increased with the time of exposure to CsA.

CONCLUSIONS

These findings indicated that CsA may contribute to neurological side effects via ROS production.

Genetic structure of pig breeds from Korea and China using microsatellite loci analysis

To understand molecular genetic characteristics of Korean pigs, the genetic relationships of nine pig breeds including two Korean pigs (Korean native pig and Korean wild pig), three Chinese pigs (Min pig, Xiang pig, and Wuzhishan pig), and four European breeds (Berkshire, Duroc, Landrace, and Yorkshire) were characterized from a 16-microsatellite loci analysis. The mean heterozygosity within breeds ranged from 0.494 to 0.703. Across multiple loci, significant deviation from Hardy-Weinberg equilibrium was observed in most pig breeds, except for two Chinese pigs (Min pig and Wuzhishan pig). This deviation was in the direction of heterozygote deficit. Across population loci, 36 of 144 significantly deviated (P < 0.05) from Hardy-Weinberg equilibrium. The mean FST, a measure of genetic divergence among subpopulations, of all loci indicated that 26.1% of total variation could be attributed to the breed difference. Relationship trees based on the Nei's DA genetic distance and scatter diagram from principal component analysis consistently displayed pronounced genetic differentiation among the Korean wild pig, Xiang pig, and Wuzhishan pig. Individual assignment test using a Bayesian method showed 100% success in assigning Korean and Chinese individual pigs into their correct breeds of origin and 100% exclusion success from all alternative reference populations at P < 0.001. These findings indicate that the Korean native pig has been experiencing progressive interbreeding with Western pig breeds after originating from a North China pig breed with a black coat color. Considering the close genetic relationship of Korean pigs to the Western breeds such as Berkshire and Landrace, our findings can be used as valuable genetic information for the preservation and further genetic improvement of the Korean native pig.

Isolation and characterization of the bovine microsatellite loci

Microsatellite loci were isolated using five repetitive probes for Korean native cattle. Eleven microsatellite loci were developed based on a biotin hybrid capture method, and enrichment of the genomic libraries (AAAT, TG, AG, T, and TGC repeats) was performed using Sau3AI adapters. The isolated markers were tested in two half-sib Korean cattle families and four imported breeds (Angus, Limousine, Holstein, and Shorthorn). Nine informative microsatellite loci were observed, and two microsatellite loci were revealed as monomorphic in Korean cattle. In the imported breeds, however, all of the markers were informative. In total, 213 alleles were obtained at the 11 loci across five breeds, and the average number of alleles found per locus, considering all populations, was 4.26. Heterozygosity was 0.71 (expected) and 0.57 (observed). The range of the polymorphic information content for the markers in all cattle populations was 0.43-0.69. Eleven percent of genetic variation was attributed to differentiation between populations as determined by the mean F (ST) values. The remaining 89% corresponded to differences among individuals. The isolated markers may be used to identify and classify the local breeds on a molecular basis.

Polyoma virus-associated nephropathy and concurrent cytomegalovirus infection in the kidney transplant recipients

INTRODUCTION

Cytomegalovirus (CMV) and polyoma virus BK (BKV) may both establish latency following primary infection. Frequent reactivation of these viruses can occur in the kidney transplant recipients. BKV may induce CMV gene expression by stimulating cellular regulator proteins or by its own gene regulator proteins. A high rate of concurrent CMV infections has been noted in kidney transplant recipients with polyoma virus-associated nephropathy (PVAN).

METHODS

PVAN was identified in 10 of 191 patients who received kidney transplants between October 1998 and September 2003. PVAN was confirmed by allograft kidney biopsy. Four of the 10 patients were complicated by concurrent CMV infection.

RESULTS

Two patients had only serological evidence of CMV infection and one patient had CMV gastritis. These three patients were treated with intravenous ganciclovir with good results. Disseminated ganciclovir-resistant CMV disease was demonstrated in the remaining patient. This 34-year-old kidney transplant recipient with PVAN died of multiorgan failure despite antiviral therapy with both ganciclovir and foscarnet.

CONCLUSION

PVAN with concurrent CMV infection in kidney transplant recipients showed variable clinical courses including mortality. Further studies are needed to elucidate the influence of PVAN on the pathogenesis of CMV infection.

Intraductal papillary mucinous tumour of the pancreas: differentiation of malignancy and benignancy by CT

AIM

To retrospectively identify signs predictive of malignant intraductal papillary mucinous tumour (IPMT) of the pancreas on computed tomography (CT) images.

MATERIALS AND METHODS

Thirty-four benign and 21 malignant pancreatic IPMTs were evaluated. Preoperative helical CT images in these 55 cases of pathologically proven pancreatic IPMT were reviewed by two radiologists unaware of the histological grading. Tumour morphological types, locations, numbers and sizes of cystic lesions, maximum main pancreatic duct diameters, the presence of septa, mural nodule, wall thickening, and calcification in cysts, communication with the main pancreatic duct, peripancreatic haziness, protrusion of duodenal papilla, pancreatic atrophy, lymphadenopathy and distant metastasis were analysed using univariate and multivariate analysis.

RESULTS

Main duct IPMTs were more likely to be malignant (71%) than branch duct (23%) or combined type IPMTs (28%; p=0.002). Among the branch duct type and combined types, large cystic lesion (p=0.018), the presence of a mural nodule (p=0.018), a thickened wall (p=0.009), and peripancreatic haziness (p=0.039) were found to predict malignancy.

CONCLUSION

CT is helpful in the preoperative differentiation of malignant and benign pancreatic IPMT. The presence of a dilated main pancreatic duct, mural nodules, thickened wall and peripancreatic haziness may be used as independent predictive signs of malignancy.

Hyperleptinaemia and hypoadiponectinaemia are associated with gallstone disease

BACKGROUND

Gallstone disease has been regarded as an obesity-related disease. Therefore, we hypothesized that leptin and adiponectin, mainly produced by adipose tissue, may play roles in gallstone disease.

PATIENTS AND METHODS

The RIA method was used to analyze serum leptin and adiponectin levels of 90 gallstone patients and 91 healthy subjects.

RESULTS

Our results showed that BMI, fasting glucose, serum AST and ALT, and leptin were significantly increased in the gallstone patients as compared with the healthy subjects (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P = 0.013, respectively). Intriguingly, serum adiponectin was the only variable to be significantly decreased in the gallstone patients (P = 0.002). Furthermore, serum AST, leptin, and adiponectin were significantly associated with gallstone disease (P < 0.001, P = 0.021, and P = 0.006, respectively). Overweight (BMI >or= 25 kg m(-2)), but not normal-weight, gallstone patients had an increased serum leptin and a decreased serum adiponectin level as compared with matched healthy subjects (P < 0.001 and P = 0.024, respectively). In addition, serum leptin was positively correlated with BMI and serum cholesterol, while serum adiponectin was inversely correlated with serum triglyceride in the gallstone patients.

CONCLUSIONS

Our study indicated that hyperleptinaemia and hypoadiponectinaemia might be involved in the occurrence of gallstone disease. However, the causal relationship of hyperleptinaemia and hypoadiponectinaemia with gallstone disease might require further investigation.

Optimizing the specific surface area of fly ash-based sorbents for flue gas desulfurization

High performance sorbents for flue gas desulfurization can be synthesized by hydration of coal fly ash, calcium sulfate, and calcium oxide. In general, higher desulfurization activity correlates with higher sorbent surface area. Consequently, a major aim in sorbent synthesis is to maximize the sorbent surface area by optimizing the hydration conditions. This work presents an integrated modeling and optimization approach to sorbent synthesis based on statistical experimental design and two artificial intelligence techniques: neural network and genetic algorithm. In the first step of the approach, the main and interactive effects of three hydration variables on sorbent surface area were evaluated using a full factorial design. The hydration variables of interest to this study were hydration time, amount of coal fly ash, and amount of calcium sulfate and the levels investigated were 4-32 h, 5-15 g, and 0-12 g, respectively. In the second step, a neural network was used to model the relationship between the three hydration variables and the sorbent surface area. A genetic algorithm was used in the last step to optimize the input space of the resulting neural network model. According to this integrated modeling and optimization approach, an optimum sorbent surface area of 62.2m(2)g(-1) could be obtained by mixing 13.1g of coal fly ash and 5.5 g of calcium sulfate in a hydration process containing 100ml of water and 5 g of calcium oxide for a fixed hydration time of 10 h.

Neural network modeling of the kinetics of SO2 removal by fly ash-based sorbent

The mechanistic modeling of the sulfation reaction between fly ash-based sorbent and SO2 is a challenging task due to a variety reasons including the complexity of the reaction itself and the inability to measure some of the key parameters of the reaction. In this work, the possibility of modeling the sulfation reaction kinetics using a purely data-driven neural network was investigated. Experiments on SO2 removal by a sorbent prepared from coal fly ash/CaO/CaSO4 were conducted using a fixed bed reactor to generate a database to train and validate the neural network model. Extensive SO2 removal data points were obtained by varying three process variables, namely, SO2 inlet concentration (500-2000 mg/L), reaction temperature (60-80 degreesC), and relative humidity (50-70%), as a function of reaction time (0-60 min). Modeling results show that the neural network can provide excellent fits to the SO2 removal data after considerable training and can be successfully used to predict the extent of SO2 removal as a function of time even when the process variables are outside the training domain. From a modeling standpoint, the suitably trained and validated neural network with excellent interpolation and extrapolation properties could have immediate practical benefits in the absence of a theoretical model.

Semi-constrained total elbow arthroplasty for the treatment of rheumatoid arthritis of the elbow

INTRODUCTION

We retrospectively reviewed the results of total elbow arthroplasty in patients with rheumatoid arthritis of the elbow followed for a minimum of two years.

METHODS

Between September 1999 and March 2001, seven patients with rheumatoid arthritis of the elbow were treated with total elbow arthroplasty using the semi-constrained Coonrad-Morrey elbow replacement prostheses. One patient died 19 months after her surgery and was excluded from the study. Two patients had bilateral total elbow replacements. Eight elbows were thus available for review. The mean age of our patients at the time of surgery was 55.5 years. The indication for surgery was severe pain and stiffness in six elbows, and distal humerus fractures in two elbows.

RESULTS

The mean duration of postoperative hospitalisation stay was 6.6 days. The average length of follow-up was 39.4 months. Six elbows had no pain, while two elbows had mild pain. The mean arc of flexion was 101.3 degrees. The mean Mayo elbow performance score was 93.1 points. Excellent results were achieved in six elbows, while two elbows had good outcome. There was one case of intraoperative lateral condylar fracture treated with internal fixation. One patient developed blisters postoperatively but resolved with dressings and antibiotics.

CONCLUSION

Our small study revealed good to excellent short-term outcome with the use of semi-constrained total elbow arthroplasty for the treatment of rheumatoid arthritis of the elbow in Asian patients.

Responses of transformed root culture of Atropa belladonna to salicylic acid stress

The effect of salicylic acid (SA) on tropane alkaloid production and the responses to SA stress of transformed root cultures of Atropa belladonna (belladonna) were investigated. Treatment of A. belladonna transformed roots with 0.2 mM SA did not have any effect on tropane alkaloid production, but two compounds were produced in the medium. These were identified as the SA derivatives methylsalicylate and methyl-o-methoxybenzoate by high-resolution mass spectrometry and UV spectrometry. In contrast, treatment with 2 mM salicylic acid stimulated tropane alkaloid release from the transformed roots into the medium by up to 35% of the total alkaloids after 24 h, and the SA derivatives were not observed in the medium. These results revealed that transformed root of A. belladonna exhibits distinct by different responses to SA stress depending on the SA concentration.

Molecular characterization and chromosomal mapping of porcine adipose differentiation-related protein (ADRP)

ADRP plays an important role in regulating lipid storage in various cells. We investigated the ADRP gene as a candidate gene for intramuscular fat deposition and marbling traits in pigs. A full-length transcript of porcine ADRP was cloned by RT-PCR and RACE. The porcine ADRP cDNA (1848 bp) contains a 1377-bp open reading frame, encoding a deduced protein of 459 amino acids, which has amino acid sequence identities of 89, 89, 82 and 81% with cattle, human, mouse and rat ADRP genes respectively. The genomic structure and sequence of the porcine ADRP were also analysed using a BAC clone of a Korean native pig. Pig ADRP comprises eight exons spanning approximately 13 kb and is located on chromosome 1 q2.3-q2.7 between microsatellite markers SW2185 and SW974. Several sequence variations were detected from nine different pig breeds. The biological role of this gene and the mapping localization indicated that the porcine ADRP is a possible candidate gene for fat deposition and marbling traits.

Quantitation of niflumic acid in human plasma by high-performance liquid chromatography with ultraviolet absorbance detection and its application to a bioequivalence study of talniflumate tablets

A rapid and simple HPLC method with UV detection (288 nm) was developed and validated for quantitation of niflumic acid in human plasma, the active metabolite of talniflumate. After precipitation with 100% methanol containing the internal standard, indomethacin, the analysis of the niflumic acid level in the plasma samples was carried out using a reverse phase C18 CAPCELL PAK (5 microm, 4.6 mm x 250 mm) column. The chromatographic separation was accomplished with an isocratic mobile phase consisting of a mixture of 0.1M sodium acetate in water and acetonitrile (37:63, v/v), adjusted to pH 6.4. This HPLC method was validated by examining its precision and accuracy for inter- and intra-day runs in a linear concentration range of 0.02-5.00 microg/mL. Stability of niflumic acid in plasma was excellent, with no evidence of degradation during sample processing (autosampler) and 30 days storage in a freezer. This validated method was successfully applied to the bioequivalence study of talniflunate in healthy volunteers.

Overexpression of Id-1 is significantly associated with tumour angiogenesis in human pancreas cancers

It has been suggested that Id-1 has a critical role in the tumour progression and aggressiveness of several human cancers. However, the clinicopathological and biological significance of Id-1 overexpression remains unclear in human primary cancer. To investigate the association between Id-1 expression and cell proliferation or tumour angiogenesis, we examined the cell cycle kinetic indices (the proliferation and apoptotic indices, PI and AI) and intratumoral microvessel density (MVD) in 65 human pancreatic cancers. We also investigated the relationship between its expression and various clinicopathological factors to determine the clinical significance of Id-1 overexpression. Out of a total 65 cases, 32 (49.3%) showed overexpression of Id-1 vs normal tissues. Id-1 expression was found to be significantly associated with MVD (P=0.002). In further analysis of subgroups with higher and lower Id-1 expression, tumours with higher Id-1 expression (scores 4 and 5) showed significantly higher MVD than tumours with lower expression of Id-1 (scores 2 and 3) (111.18+/-57.14 vs 64.13+/-28.19, P<0.001). However, no significant association was found between Id-1 overexpression and patient survival rate. No significant association was also found between Id-1 expression and cell cycle kinetic indices (PI or AI) in pancreatic cancer. Moreover, the overexpression of Id-1 protein was not correlated with any significant clinicopathologic factors. These findings indicate that Id-1 overexpression is closely related with tumour angiogenesis and a higher density of intratumoral vessel, but that it is not associated with a poorer prognosis of survival or a higher cell proliferative potential in human pancreatic cancer.

Heavy ion observations by MARIE in cruise phase and Mars orbit

The charged particle spectrum for nuclei from protons to neon, (charge Z=10) was observed during the cruise phase and orbit around Mars by the MARIE charged particle spectrometer on the Odyssey spacecraft. The cruise data were taken between April 23, 2001 and mid-August 2001. The Mars orbit data were taken March 5, 2002 through May 2002 and are scheduled to continue until August 2004. Charge peaks are clearly separated for charges up to Z=10. Especially prominent are the carbon and oxygen peaks, with boron and nitrogen also clearly visible. Although heavy ions are much less abundant than protons in the cosmic ray environment, it is important to determine their abundances because their ionization energy losses (proportional to Z2) are far more dangerous to humans and to instruments. Thus the higher charged nuclei make a significant contribution to dose and dose equivalent received in space. Results of the charged particle spectrum measurements will be reported.

Gamma-pyrone derivatives, kojic acid methyl ethers from a marine-derived fungus Alternaria [correction of Altenaria] sp

Kojic acid dimethyl ether (1), and the known kojic acid monomethyl ether (2), kojic acid (3) and phomaligol A (4) have been isolated from the organic extract of the broth of the marine-derived fungus Alternaria sp. collected from the surface of the marine green alga Ulva pertusa. The structures were assigned on the basis of comprehensive spectroscopic analyses. Each isolate was tested for its tyrosinase inhibitory activity. Kojic acid (3) was found to have significant tyrosinase inhibitory activity, but compounds 1, 2, and 4 were found to be inactive.

Inhibitory effects of Ramulus mori extracts on melanogenesis

To develop an active agent for skin whitening, the inhibitory effects of 285 plant extracts on tyrosinase activity were examined, and one plant extract having tyrosinase inhibition activity was chosen. Ramulus mori (young twigs of Morus alba L.) extracts showed inhibition activity in tyrosinase and melanin synthesis in B-16 melanoma cells. To clarify the mechanism of its inhibition on melanogenesis, the effect of R. mori extracts on tyrosinase activity, synthesis, and gene expression was evaluated. R. mori extracts showed tyrosinase inhibition activity by competitive method, and there was no suppression of tyrosinase synthesis and gene expression. Further, to evaluate the inhibitory activity of R. mori in vivo, its effect on melanin production in UV-induced brown guinea pigs was examined, where a decrease of melanin production in the guinea pig model was observed. Also, R. mori extracts showed no toxicity in animal tests such as the acute toxicity test, the skin irritation test, the eye irritation test, the skin sensitization test, and the acute oral toxicity test, and no toxicity in the human skin irritation test. A single compound from R. mori extracts was purified using various column chromatography and recrystallization, and its chemical structure was identified using mass chromatography, IR spectroscopy, and NMR analysis. The chemical structure was that of 2,3',4,5'-tetrahydroxystilbene(2-oxyresveratrol) and showed inhibition activity on tyrosinase (IC(50) = 0.23 microg/ml). Also, R. mori extracts inhibited tyrosinase activity in a competitive manner (Ki = 1.5 x 10(-6) M) when L-tyrosine was used as a substrate.

Inducible nitric oxide synthase (iNOS) immunoreactivity and its relationship to cell proliferation, apoptosis, angiogenesis, clinicopathologic characteristics, and patient survival in pancreatic cancer

BACKGROUND

The clinicopathological and biological significance of the expression of iNOS in pancreatic cancer remains unclear. The goal of this study was to determine the possible roles and clinical significance of iNOS expression in pancreatic cancer.

METHODS

Seventy-two pancreatic adenocarcinoma tissue specimens were obtained by surgical resection. We investigated the immunohistochemical expression of iNOS in 72 patients with pancreatic cancer with respect to variable clinicopathological characteristics, proliferation activity (assessed by Ki-67 expression), apoptosis (assessed by TUNEL stain), and microvessel density (assessed by CD34 expression; angiogenesis).

RESULTS

Immunohistochemical investigations demonstrated immunolabeling of tumor cells with anti-iNOS antibody. Positivity for iNOS was observed in 48/72 (66.7%). The expression of iNOS protein did not correlate with age, bilirubin, tumor marker, location, size, AJCC stage, differentiation, distant metastasis, or patient survival. No significant association was found between iNOS expression and proliferation or microvessel density in pancreatic cancer. Apoptotic index (AI) of positive iNOS expressions were significantly higher than negative expression (p < 0.001).

CONCLUSION

Inducible nitric oxide synthase (iNOS) is expressed by human pancreatic cancer, and its presence is positively correlated with apoptosis of cancer cells that could provide the basis for the development of therapeutic strategies in human pancreatic cancer.