Alterations of fatty acid β-oxidation capability in the liver of ketotic cows

Dairy cows are highly susceptible to ketosis after parturition. In the present study, we evaluated the expression of fatty acid β-oxidation-related enzymes in the liver of ketotic (n=6) and nonketotic (n=6) cows. Serum levels of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and glucose were determined by using standard biochemical techniques. The mRNA abundance and protein content of acyl-CoA synthetase long-chain (ACSL), carnitine palmitoyltransferase I (CPT I), carnitine palmitoyltransferase II (CPT II), acyl-CoA dehydrogenase long chain (ACADL), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS), and acetyl-CoA carboxylase (ACC) were evaluated by real-time PCR and ELISA. We found that serum glucose levels were lower in ketotic cows than in nonketotic cows, but serum BHBA and NEFA concentrations were higher. Messenger RNA and protein levels of ACSL were significantly higher in livers of ketotic cows than those in nonketotic cows. In contrast, mRNA levels of CPT I and mRNA and protein levels of CPT II, ACADL, HMGCS, and ACC were decreased in the liver of ketotic cows. Serum NEFA concentration positively correlated with ACSL protein levels and negatively correlated with protein levels of CPT II, HMGCS, ACADL, and ACC. In addition, serum BHBA concentration negatively correlated with protein levels of CPT II, HMGCS, and ACADL. Overall, fatty acid β-oxidation capability was altered in the liver of ketotic compared with nonketotic cows. Furthermore, high serum NEFA and BHBA concentrations play key roles in affecting pathways of fatty acid metabolism in the liver.

SU-E-I-75: A New Method for Prostate Cancer Localization Using Multispectral MRI

PURPOSE

To develop a new method for automatic localization of prostate cancer using multispectral MRI data.

METHODS

Multispectral MRI including MR spectroscopic imaging (MRSI), T2 weighted MRI, diffusion weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI, has been used for cancer target localization. The combination of multiple MRI imaging technologies provides more useful information than one single technology alone about prostate cancer and has advantages for target definition in radotherapy treatment and quantitative evaluation of tumor response. However, manual cancer localization using multispectral MRI dataset is a tedious task and prone to inter-/intra-observer variability. Automatic localization methods using multispectral MRI data is highly desired. In this paper, a fuzzy fusion framework for automatically localizing prostate cancer with multispectral MRI data is presented. Firstly, for each kind of MRI images, a membership function is created to calculate the membership-degrees of image elements belonging to cancer region. Secondly, a fuzzy fusion operator is used to fuse different membership- degrees corresponding to the same regions. Lastly, the Result of fusion is further adjusted with fuzzy region growing process, leading to the final membership-degree map. And cancer volume is finally defined by setting up a threshold on the map.

RESULTS

The new method was tested with one multispectral MRI patient dataset and results from our experimental study are compared with the one obtained form a manual method performed by an experienced pathologist. Quantitative analysis shows that the specificity is 98.89%, sensitivity is 62.85% and accuracy is 95.42%, respectively. It illustrates the feasibility of utilizing this framework in the clinical application.

CONCLUSIONS

The feasibility study shows the new method reported in this paper achieves automatic localization for prostate cancer and can be easily implemented in clinical applications. We are currently conducting a clinical study for testing the effectiveness and reliability, and further developing this method. *supported by NSFC-81171342 support by National Science Foundation of China (NSFC-81171342).

Changes of serum omentin levels and relationship between omentin and adiponectin concentrations in type 2 diabetes mellitus

BACKGROUND

Omentin has recently been characterized as a potent insulin-sensitizing adipokine, but its pathophysiologic roles in humans remain largely unknown.

OBJECTIVE

To investigate the change of fasting serum omentin levels and evaluate the relationship of omentin with adiponectin in patients with type 2 diabetes mellitus.

DESIGN

35 patients with newly diagnosed type 2 diabetes (T2DM), 35 patients with impaired glucose regulation (IGT) and 35 patients with normal glucose tolerance (NGT) participated in this study. Fasting serum omentin and adiponectin levels were measured by enzyme-linked immunosorbent assay. The relationship between serum omentin, serum adiponectin levels and metabolic parameters was also analyzed.

RESULTS

Fasting serum omentin levels were significantly lower in T2DM and IGT groups than in NGT group (16.75±1.71 vs. 18.62±1.22 vs. 24.60±1.43 ng/ml, all P<0.01). Obesity subjects had significantly lower serum omentin levels than normal body weight subjects ( P<0.01 or P<0.05). Female subjects had moderately higher fasting serum omentin levels than male subjects. Fasting serum adiponectin levels showed a similar variation trend to omentin in T2DM and NGT groups, obesity and normal body weight subjects, female and male subjects. Fasting serum omentin levels were negatively correlated with HOMA-IR and positively correlated with adiponectin. Moreover, HOMA-IR and adiponectin were the independently predictors of fasting serum omentin levels.

CONCLUSIONS

Serum omentin levels possibly play an important role in the pathogenesis of insulin resistance and diabetes. More importantly, there is such a close connection between serum omentin and adiponectin levels that regulation of omentin may be dependent on adiponectin.

Effect of Saccharomyces cerevisiae fermentation product on ruminal fermentation and nutrient utilization in dairy cows

The goal of this experiment was to investigate the effect of yeast culture (Saccharomyces cerevisiae) on rumen fermentation, nutrient utilization, and ammonia and methane emission from manure in dairy cows. Eight ruminally cannulated Holstein cows were allocated to 2 dietary treatments in a crossover design. Treatments were control (no yeast culture) and XP (yeast culture, fed at 56 g/head per day; XP, Diamond V Mills Inc., Cedar Rapids, IA). Dry matter intake, milk yield, milk composition, and body weight were similar between treatments. Milk urea nitrogen concentration was also not affected by treatment. Rumen pH was similar between the control and XP treatments, but rumen ammonia concentration tended to be lower with XP than with the control. Treatment had no effect on concentrations of total or individual volatile fatty acids, protozoal counts, polysaccharide-degrading activities (except amylase activity that tended to be increased by XP), or methane production in the rumen. Urinary N losses did not differ significantly between treatments, but allantoin and total purine derivative excretions and the estimated microbial N outflow from the rumen tended to be increased by XP compared with the control treatment. Total-tract apparent digestibility of dietary nutrients was not affected by XP. Milk fatty acid composition was also not altered by XP supplementation. Cumulative (253 h) ammonia and methane emissions from manure, measured in a steady-state gas emission system, were slightly decreased by XP. Overall, the yeast culture tested had little effect on ruminal fermentation, digestibility, or N losses, but tended to reduce rumen ammonia concentration and increase microbial protein synthesis in the rumen, and decreased ammonia and methane emissions from manure.

Late presentation of aorto-right ventricular fistula and associated aortic regurgitation following penetrating chest trauma

We present a case in which a 39-year-old man was assaulted in 2002 and sustained penetrating chest trauma. He was treated conservatively, and presented six years later with exertional dyspnoea and a continuous murmur. Echocardiography detected an aorta-right ventricular fistula and an important aortic regurgitation. The aorta-right ventricular fistula was repaired and the aortic valve was replaced with a mechanical prosthesis. Traumatic aorto-right ventricular fistulas and aortic regurgitation are often masked by the primary injury and may take months or years to become clinically evident.

Conservative management of ovarian cysts in pregnancy during third trimester and intrapartum

We treated two patients with large ovarian cysts in pregnancy conservatively. In both cases, aspiration of the cysts under ultrasound guidance allowed successful vaginal delivery. In one case, the cyst fluid reaccumulated, and required further aspiration in labour. In both cases, benign ovarian cysts were removed laparoscopically at a later date. Various strategies for dealing with ovarian cysts in pregnancy are discussed.

Origination of chimeric genes through DNA-level recombination

Comparative genomics is rapidly bringing to light the manifold differences that exist within and between species on the molecular level. Of fundamental interest are the absolute and relative amounts of the genome dedicated to protein coding regions. Results thus far have shown surprising variation on both the polymorphism and divergence levels. As a result, there has been an increase in efforts aimed to characterize the underlying genetic mechanisms and evolutionary forces that continue to alter genomic architecture. In this review we discuss the formation of chimeric genes generated at the DNA level. While the formation of chimeric genes has been shown to be an important way in which coding regions of the genome evolve, many of the detailed studies have been limited to chimeric genes formed through retroposition events (through an RNA intermediate step). Here we provide a short review of the reported mechanisms that have been identified for chimeric gene formations, excluding retroposition-related cases, and discuss several of the evolutionary analyses carried out on them. We emphasize the utility chimeric genes provide for the study of novel function. We also emphasize the importance of studying chimeric genes that are evolutionarily young.

Combination therapy with gefitinib and capecitabine in metastatic breast cancer (MBC): A phase I trial

10564

Background: Preclinical models have suggested synergy between the EGFR tyrosine kinase inhibitor gefitinib (G) and the 5-FU prodrug capecitabine (C), an active treatment for MBC. This phase I study was designed to explore the safety of this all-oral regimen in patients (pts) with MBC. Methods: Pts were treated in sequential cohorts (n = 3–6) using a fixed dose of G (250 mg qd continuously) and escalating doses of C (1500 mg/m2/day, 1750 mg/m2/day, and 2000 mg/m2/day) in a 21-day cycle. An additional 10 pts were enrolled in a validation cohort at the maximum tolerated dose (MTD). Dose limiting toxicity (DLT) was defined during the first cycle as any grade 3/4 toxicity or a delay >3 weeks due to unresolved toxicity. The primary endpoint was safety; secondary endpoints included assessments of tumor response (using RECIST criteria), adherence to the oral regimen, and biomarker measurements. Results: 19 pts were enrolled; the mean age was 49 y, 58% of tumors were hormone receptor positive, and 10% were HER2 positive. The mean number of prior MBC chemotherapy regimens was 1.2 and 74% had visceral spread. No pts in dose escalation cohorts had DLT during cycle 1. The 10 pts in the validation cohort (MTD C 2000 mg/m2) had 3 DLTs in cycle 1 and 1 DLT in cycle 2 (95% CI 12–74%). For all pts at C 2000 mg/m2 (n = 13), there was no grade 4 toxicity, however 5 (38%) had grade 3 toxicity, 7 (54%) required a C dose reduction, and 2 (15%) came off study for persistent toxicity. 3 pts (23%) experienced grade 3 diarrhea, and 4 pts (31%) had moderate to severe hand/foot syndrome. There were no objective responses (PR or CR) observed out of 18 evaluable pts. The mean number of completed cycles of therapy was 4.8, and 3 pts (16%) were treated for > 24 weeks. An exploratory analysis of serum EGFR measurements demonstrated no association of pre- or post-therapy values with lack of progression. Monitoring adherence to oral therapy using a microelectronic monitoring system (MEMS) was feasible, and detailed data will be presented. Conclusions: In this phase I dose escalation trial of G/C therapy in women with MBC, treatment was generally well tolerated, with a confirmed C MTD of 2000 mg/m2. Moderate toxicity and dose reductions were common. In this small cohort, the G/C combination did not appear to have substantial anti-tumor activity.

[Table: see text]

Cetacean captures, strandings and mortalities in South Australia 1881-2000, with special reference to human interactions

This study summarizes 660 events involving captured, live-stranded and dead cetaceans in South Australia between 1881 and 2000. Emphasis is placed on records (n = 361) during 1985-2000 when an active necropsy programme was underway. Average number of events per year was 30.4 and the most common species were the short-beaked common dolphin (Delphinus delphis) and Indo-Pacific bottlenose dolphin (Tursiops aduncus). Records were assigned to nine categories of circumstance/cause of death. Summarizing the total database, 60% were unknown circumstance, 22% not obviously anthropogenic, 13% unintentional human-related and 5% intentional human-related. In the data set of records for 1985-2000, 50% were unknown, 25% were not obviously anthropogenic, 20% were unintentional humanrelated and 5% were intentional killings. Non-anthropogenic circumstances included neonatal deaths, live strandings, significant diseases, shark attacks and choking. Cornynebacterium ulcerans is recorded for the first time in a cetacean. Unintentional circumstances included entanglement in fishing and aquaculture equipment (17% of necropsied carcasses from 1985-2000) and boat strikes. Intentional human-related circumstances were captures for live display and illegal killing. Five percent of the necropsied carcasses during 1985-2000 were attributed to shootings or stabbings/spearings. There is need for a formal reporting procedure for marine mammal deaths and human interaction involving injury and for steps to be taken to reduce human impacts.

[The relationship between surgical staging, pathologic grading, operative type and postoperative recurrence in giant cell tumor of bone]

Sixty-eight surgical procedures of 58 patients with Giant Cell Tumor of Bone(GCT) were followed up over two years. The recurrence rate of GCT was Stage 1: 0 in 5, Stage 2: 15.4% in 39 and Stage 3: 37.5% in 24. It was significantly higher in Stage 3 than in Stage 2 (P < 0.05). The recurrence rate of GCT in Stage 2 was 30.8% in 13 intralesional curettage, and 0 in 17 wide or radical resection(P < 0.05). We conclude that the surgical staging of GCT has important value in predicting postoperative recurrence, in accurately evaluating the operative efforts and in guiding treatment, and that the operative type is a significant factor effecting on the recurrence of GCT.

[Analysis of complications and deaths in aged patients with obstructive jaundice]

The reasons of complications and deaths in 98 aged patients with obstructive jaundice were analysed in the paper. Among them, 52 cases were diagnosed as benign obstruction, 46 cases as malignant obstruction; 92 patients were treated by surgical management(15 died), 6 patients were treated without operation(4 died). The results showed that effective management on time and intensive perioperative care are important to minimize the mortality rate. Malignant obstructive jaundice was more harmful to the patients' renal function no the mortality rate would be increased. The operations, internal drainage and pressure reduction of biliary duct, were performed on time, thus the survival rate was improve.

ExInt: an Exon Intron Database

The Exon/Intron Database (ExInt) stores information of all GenBank eukaryotic entries containing an annotated intron sequence. Data are available through a retrieval system, as flat-files and as a MySQL dump file. In this report we discuss several implementations added to ExInt, which is accessible at http://intron.bic.nus.edu.sg/exint/newexint/exint.html.

Intravenous tissue-type plasminogen activator therapy for ischemic stroke: Houston experience 1996 to 2000

CONTEXT

Intravenous tissue-type plasminogen activator (tPA) therapy using the National Institute of Neurological Disorders and Stroke criteria has been given with variable safety to less than 5% of the patients who have ischemic strokes nationwide. Our center is experienced in treating large numbers of stroke patients with intravenous tPA.

OBJECTIVE

To report our total 4-year experience in the treatment of consecutive patients who had an ischemic stroke.

DESIGN

Prospective inception cohort registry of all patients seen by our stroke team and an additional retrospective medical record review of all patients treated between January 1, 1996, and June 1, 2000.

SETTING

A veteran stroke team composed of fellows and stroke-specialty faculty servicing 1 university and 3 community hospitals in a large urban setting.

PATIENTS

Consecutive patients with ischemic stroke treated within the first 3 hours of symptom onset.

INTERVENTION

According to the National Institute of Neurological Disorders and Stroke protocol, 0.9 mg/kg of intravenous tissue-type plasminogen activator was administered.

MAIN OUTCOME MEASURES

Number and proportion treated, patient demographics, time to treatment, hemorrhage rates, and clinical outcome.

RESULTS

A total of 269 patients were treated between January 1, 1996, and June 1, 2000. Their mean age was 68 years (age range, 24-93 years); 48% were women. This represented 9% of all patients admitted with symptoms of cerebral ischemia at our most active hospital (over the final 6 months, 13% of all patients with symptoms of cerebral ischemia and 15% of all acute ischemic stroke patients). Before treatment the mean +/- SD National Institutes of Health Stroke Scale (NIHSS) score was 14.4 +/- 6.1 points (median, 14 points; range, 4-33 points). A tPA bolus was given at 137 minutes (range, 30-180 minutes); 28% of the patients were treated within 2 hours. The mean door-to-needle time was 70 minutes (range, 10-129 minutes). The symptomatic intracerebral hemorrhage rate was 5.6% of those patients with a second set of brain scans (4.5% of all patients), with a declining trend from 1996 to 2000. Protocol violations were found in 13% of all patients; the symptomatic intracerebral hemorrhage rate in these patients was 15%. At 24 hours, the NIHSS score was 10 +/- 8 points (median, 8 points; range, 0-36 points). In-hospital mortality was 15% and the patients' discharge NIHSS scores were 7 +/- 7 points (median, 3 points; range, 0-35 points).

CONCLUSIONS

Intravenous tPA therapy can be given to up to 15% of the patients with acute ischemic stroke with a low risk of symptomatic intracerebral hemorrhage. Successful experience with intravenous tPA therapy depends on the experience and organization of the treating team and adherence to published guidelines.

Evolution of novel genes

Much progress in understanding the evolution of new genes has been accomplished in the past few years. Molecular mechanisms such as illegitimate recombination and LINE element mediated 3' transduction underlying exon shuffling, a major process for generating new genes, are better understood. The identification of young genes in invertebrates and vertebrates has revealed a significant role of adaptive evolution acting on initially rudimentary gene structures created as if by evolutionary tinkers. New genes in humans and our primate relatives add a new component to the understanding of genetic divergence between humans and non-humans.

Kinetic measurements of cell surface E-selectin/carbohydrate ligand interactions

Selectin/ligand interactions initiate the multistep adhesion and signaling cascades in the recruitment of leukocytes from circulation to inflamed tissues and may also play a role in tumor metastasis. Kinetic properties of these interactions are essential determinants governing blood-borne cells' tethering to and rolling on the vessel wall. Extending our recently developed micropipette method, we have measured the kinetic rates of E-selectin/ligand interactions. Red cells coated with an E-selectin construct were allowed to bind HL-60 or Colo-205 cells bearing carbohydrate ligands. Specific adhesions were observed to occur at isolated points, the frequency of which followed a Poisson distribution. These point attachments were formed at the same rate with both the HL-60 and Colo-205 cells (0.14 +/- 0.04 and 0.13 +/- 0.03 microm2 s(-2) per unit density of E-selectin, respectively) but dissociated from the former at a rate twice as fast as did from the latter (0.92 +/- 0.23 and 0.44 +/- 0.10 s(-1), respectively). The reverse rates agree well with those measured by the flow chamber. The forward rates are orders of magnitude higher than those of Fcgamma receptors interacting with IgG measured under similar conditions, consistent with the rapid kinetics requirement for the function of E-selectin/ligand binding, which is to capture leukocytes on endothelial surfaces from flow.

Aspartyl proteinase genes from apicomplexan parasites: evidence for evolution of the gene structure

Aspartyl proteinases are a widely distributed family of enzymes. All vertebrate aspartyl proteinases share a conserved nine-exon gene structure, but in other organisms the structure of aspartyl proteinase genes varies considerably. The exon-intron patterns generally reflect phylogeny based on amino acid sequences. However, close comparison of these gene structures reveals some striking features, such as the conservation of intron positions and intron phases between aspartyl proteinases from nematodes and apicomplexans. Here, we discuss the implications of gene structure for the possible evolution of the aspartyl proteinase family, with particular reference to the plasmepsins of Plasmodium falciparum and eimepsin from Eimeria tenella.

[Studies on transference of hydrogenase genes of Rhizobium arachis]

The hydrogen-uptake genes were transferred into wild Rhizobium arachis Ra strains (Hup-, Nif+, Apr) by triparental mating using pRK2013 as help plasmid. A transconjugant R. arachis Rz34-2(Hup+, Nif+, Apr, Tcr) which expressed high activities of hydrogenase and nitrogenase under free-living and symbiotic state was screened. Peanut inoculation test with recipient R. arachis Ra34, transcojugant Rz34-2 and control strain R. arachis L8-3 (Hup+, Nif+) was carried out respectively. The results showed that, compare to treatment without inoculation, inoculation with R. arachis Ra34 and R. arachis L8-3, the dry weight of leaf inoculated with transconjuant Rz34-2 increased 6.2%, 7.6% and 6.3% respectively; the N-content of seed increased 8.8%, 10.0% and 6.0%; the output increased 18.8%, 10.5% and 10.7%. This suggested that legume plants inoculated with Rhizobium strains (Hup+) were more efficient to accumulate N and to increase its output.

An outcome study of breast reconstruction: presurgical identification of risk factors for complications

BACKGROUND

Breast reconstruction following mastectomy has been shown to have a salutary effect on the overall psychological well-being of women being treated for breast cancer. Unfortunately, however, not every patient is an ideal candidate for reconstruction. Complications stemming from reconstructive surgery can cause significant morbidity, the most important of which may be the delay of subsequent adjuvant antineoplastic therapies, and therefore may not be in the best interests of the patient.

METHODS

A retrospective study was performed on a consecutive series of 123 breast reconstructions in 98 patients, performed by one of two plastic surgeons, in a university setting over a 5-year period, for all surgical outcomes. Specifically, wound-healing complications, infections, and reoperations leading to the potential delay of subsequent chemotherapy or radiotherapy were recorded, and possible risk factors leading to these were sought.

RESULTS

Three presurgical risk factors were found to have a statistically significant influence on the development of complications following breast reconstruction. These were: (1) increasing obesity, defined by the body mass index, (2) an active or recent (<5 year) history of cigarette smoking, and (3) a history of previous radiation exposure. Odds ratios were used to describe the magnitude of the effect of each factor for the development of complications. An ordinal regression analysis was used to create a nomogram based on this information that can be used to calculate any individual patient's presurgical risk for developing major complications following breast reconstruction, based on the presence of these factors.

CONCLUSIONS

It is possible, based on the presence of specific presurgical risk factors, to predict the probability of developing major complications following breast reconstruction. This information can be useful to the referring physician and plastic surgeon alike in determining which patients are the best candidates for breast reconstruction and which type of reconstruction would be best suited for each individual patient.

A comparison of the Ameroid constrictor versus ligation in the surgical management of single extrahepatic portosystemic shunts

Twenty-two dogs were managed surgically for a single extrahepatic portosystemic shunt; 12 with surgical ligation and 10 with an Ameroid constrictor. Utilization of the Ameroid constrictor significantly decreased surgery time to approximately half that of the ligation technique. A decreased intraoperative and postoperative complication rate was noted with the Ameroid constrictor group. Follow-up evaluation demonstrated comparable efficacy when comparing surgical techniques. The Ameroid constrictor offered a surgical occlusion technique for management of a single extra-hepatic portosystemic shunt that was equally effective to ligation while shortening surgical time and minimizing the risks that are commonly associated with ligation of the shunting vessel.

Measurement of CP-violating asymmetries in B0 decays to CP eigenstates

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta = 0.34+/-0.20 (stat)+/-0.05 (syst).

Comparison of the viscoelastic properties of normal hepatocytes and hepatocellular carcinoma cells under cytoskeletal perturbation

The viscoelastic properties of both hepatocytes and hepatocellular carcinoma (HCC) cells were measured by means of a micropipette aspiration technique. Experimental results were analyzed with a three-element standard linear solid model, in which an elastic element, K1, is in parallel with a Maxwell element composed of another elastic element, K2, in series with a viscous element, mu. Further, we investigated the relevance of viscoelastic properties of these two types of cells to the cytoskeleton structures by treating cells with three cytoskeletal perturbing agents, namely cytochalasin D (CD), colchicine (Col) and vinblastine (VBL). The results showed that the elastic coefficients, but not viscous coefficient of HCC cells (K1 = 103.6 +/- 12.6 N m-2, K2 = 42.5 +/- 10.4 N m-2, mu = 4.5 +/- 1.9 Pa s, n = 30), were significantly higher than the corresponding values for hepatocytes (K1 = 87.5 +/- 12.1 N m-2, K2 = 33.3 +/- 10.3 N m-2, mu = 5.9 +/- 3.0 Pa s, n = 24). Upon treatment with CD, the viscoelastic coefficients of both hepatocytes and HCC cells decreased uniformly, with magnitudes for the decrease in elastic coefficients of HCC cells (K1: 68.7 to 81.7 N m-2, 66.3 to 78.9%; K2: 34.5 to 37.1 N m-2, 81.2 to 87.3%) larger than those for normal hepatocytes (K1: 42.6 to 49.8 N m-2, 48.7 to 56.9%; K2: 17.2 to 20.4 N m-2, 51.7 to 61.3%). There was a smaller decrease in the viscous coefficient of HCC cells (2.0 to 3.4 Pa s, 44.4 to 75.6%) than that for hepatocytes (3.0 to 3.9 Pa s, 50.8 to 66.1%). Upon treatment with Col and VBL, the elastic coefficients of hepatocytes generally increased or tended to increase while those of HCC cells decreased. The differences in either the pattern or the magnitude of the effect of cytoskeletal perturbing agent on the viscoelastic properties between HCC cells and hepatocytes might possibly reflect differences in the state of the cytoskeleton structure and function, or in the cells' sensitivity to perturbing agent treatment between these two types of cells. Changes in the viscoelastic properties of cancer cells might well affect tumor cell invasion and metastasis as well as interactions between tumor cells and their micro-mechanical environments.

Isomerization of lycopene in the gastric milieu

There is considerable interest in the bioavailability of carotenoids from the diet and their bioactivity in vivo. Little is known, however, of the preabsorption events in the gastric lumen on the breakdown or isomerisation of dietary carotenoids. In this study the effects of the acidic environment found in the gastric milieu on lycopene have been investigated. The results show that under these conditions all-trans-lycopene is isomerised to cis-isomers, which may be implicated in enhanced absorption from the small intestine. Furthermore the pH, as well as the food matrix, seems to have an influence on the level of isomerisation of this carotenoid.

Investigation on the rheological properties of hepatocellular carcinoma cells and their relevance to cytoskeleton structure

OBJECTIVE

To investigate the relevance of the rheological properties, i.e., viscoelasticities and adhesion to basement membrane components coated surface, of both hepatocytes and hepatocellular carcinoma (HCC) cells to the cytoskeleton structure.

METHODS

Micropipette aspiration technique was adopted to measure viscoelastic coefficients and adhesion forces to 2 microg/ml collagen IV/1.25 microg/ml laminin coated surface of the cells. Two kinds of cytoskeleton perturbing agents, colchicine and cytochalasin D, were used to treat both HCC cells and hepatocytes and the effects of these treatments on cell viscoelastic coefficients and cell adhesion forces were investigated.

RESULTS

Upon treatment of cells with colchicine in a concentration range of 1 to 60 mg/L, the elastic coefficients, especially the first elastic coefficient K1, and adhesion forces of hepatocytes generally tended to increase or increased significantly while, in contrast, viscoelastic coefficients and adhesion forces of HCC cells decreased obviously. Upon treatment of cells with cytochalasin D in a concentration range of 0.25-5.00 mg/L, viscoelastic coefficients of both hepatocytes and HCC cells decreased uniformly, with a larger magnitude for the decrease in elastic coefficients and adhesion forces of HCC cells than for those of hepatocytes. Adhesion forces of hepatocytes and HCC cells onto collagen IV/laminin coated surface varied similarly as viscoelastic coefficients under the action of the cytoskeleton perturbing agents. A significant positive correlation existed between changes of HCC cell adhesion forces on collagen IV/laminin coated surfaces and those of cell elastic coefficients (P<0.01).

CONCLUSIONS

The effects of cochicine and cytochalasin D on rheological properties of HCC cells differed significantly either in ways or extents from those on rheological properties of hepatocytes. These results might reflect the difference in the state of cytoskeleton structure and function among these two kinds of cells.

IE-Kb: intron exon knowledge base

SUMMARY

IE-Kb (Intron Exon-Knowledge base) illustrates the intron-exon dynamics in eukaryotic genes. We have developed three different knowledge sets, namely 'Non-redundant ExInt', 'Non-redundant Pfam-ExInt complement' and 'Non-redundant GenBank eukaryotic subdivisional sets' to understand this phenomenon. Statistical analysis is performed on each knowledge set and the results are made available online. The entries in knowledge sets are ranked based on their intron length, exon length and protein length with relational hyper-links to the corresponding intron phase, intron position, intron sequence, gene definition and parent GenBank entry.

Testing the "proto-splice sites" model of intron origin: evidence from analysis of intron phase correlations

A few nucleotide sites of nuclear exons that flank introns are often conserved. A hypothesis has suggested that these sites, called "proto-splice sites," are remnants of recognition signals for the insertion of introns in the early evolution of eukaryotic genes. This notion of proto-splice sites has been an important basis for the insertional theory of introns. This hypothesis predicts that the distribution of proto-splice sites would determine the distribution of intron phases, because the positions of introns are just a subset of the proto-splice sites. We previously tested this prediction by examining the proportions of the phases of proto-splice sites, revealing nothing in these proportion distributions similar to observed proportions of intron phases. Here, we provide a second independent test of the proto-splice site hypothesis, with regard to its prediction that the proto-splice sites would mimic intron phase correlations, using a CDS database we created from GenBank. We tested four hypothetical proto-splice sites G / G, AG / G, AG / GT, and C/AAG / R. Interestingly, while G / G and AG / GT site phase distributions are not consistent with actual introns, we observed that AG / G and C/AAG / R sites have a symmetric phase excess. However, the patterns of the excess are quite different from the actual intron phase distribution. In addition, particular amino acid repeats in proteins were found to partially contribute to the excess of symmetry at these two types of sites. The phase associations of all four sites are significantly different from those of intron phases. Furthermore, a general model of intron insertion into proto-splice sites was simulated by Monte Carlo simulation to investigate the probability that the random insertion of introns into AG / G and C/AAG / R sites could generate the observed intron phase distribution. The simulation showed that (1) no observed correlation of intron phases was statistically consistent with the phase distribution of proto-splice sites in the simulated virtual genes; (2) most conservatively, no simulation in 10,000 Monte Carlo experiments gave a pattern with an excess of symmetric (1, 1) exons larger than those of (0, 0) and (2, 2), a major statistical feature of intron phase distribution that is consistent with the directly observed cases of exon shuffling. Thus, these results reject the null hypothesis that introns are randomly inserted into preexisting proto-splice sites, as suggested by the insertional theory of introns.

Liquid chromatographic method for determination of patulin in clear and cloudy apple juices and apple puree: collaborative study

A collaborative trial was conducted to validate the effectiveness of a liquid chromatographic (LC) procedure for determination of patulin in both clear and cloudy apple juices and apple puree. The test portion of clear apple juice was directly extracted with ethyl acetate; cloudy apple juice and apple puree were treated with pectinase enzyme before extraction. After back-extraction into sodium carbonate to remove interfering acidic compounds, the extract was dried and concentrated, and patulin was determined by LC with UV detection. Clear and cloudy apple juices, apple puree test samples naturally contaminated with patulin, and blank test samples for spiking with patulin were sent to 14 collaborators in 12 different European countries. Test portions of each of the 3 test sample types were spiked with patulin at 75 ng/g. Recoveries of patulin ranged from 80 to 92%. Based on the results for spiked test samples (blind pairs) and naturally contaminated test samples (blind pairs at 3 levels), the relative standard deviations for repeatability (RSDr) and reproducibility (RSDR) ranged from 8 to 35% and 11 to 36%, respectively. Although HORRAT values of <1.4 were obtained for all 3 matrixes at patulin levels ranging from 26 to 121 ng/g, better performance values (RSDr values 6-10% and RSDR values 11-25%) were obtained for clear and cloudy apple juice spiked above 50 ng/g, which is either the statutory limit or the advisory level for patulin contamination in apple juices in many countries.

[Influence of solvents on IR spectrum of aromatic amines]

21 aromatic amines in different solution system are studied by FTIR. The IR spectra of these aromatic amines are greatly influenced by solvents. The IR stretching frequency of amino group in benzene has a larger bathochromic shift than that in tetrachloromethane (CCl4). It is also found that the frequency, the peak shape and relative strength of absorption for their amino group are not affected by the various concentrations.