On multiscale approaches to three-dimensional modelling of morphogenesis

In this paper we present the foundation of a unified, object-oriented, three-dimensional biomodelling environment, which allows us to integrate multiple submodels at scales from subcellular to those of tissues and organs. Our current implementation combines a modified discrete model from statistical mechanics, the Cellular Potts Model, with a continuum reaction-diffusion model and a state automaton with well-defined conditions for cell differentiation transitions to model genetic regulation. This environment allows us to rapidly and compactly create computational models of a class of complex-developmental phenomena. To illustrate model development, we simulate a simplified version of the formation of the skeletal pattern in a growing embryonic vertebrate limb.

Evaluations of biomarkers associated with 5-FU sensitivity for non-small-cell lung cancer patients postoperatively treated with UFT

The sensitivity to 5-fluorouracil (5-FU) has been reported to be associated with target molecule thymidylate synthase (TS), fluoropyrimidine-metabolising enzymes such as orotate phosphoribosyltransferase (OPRT), and dihydropyrimidine dehydrogenase (DPD). We performed an immunohistochemical study on the clinical significance of TS, OPRT, and DPD expression using 151 resected non-small-cell lung cancer (NSCLC) patients postoperatively treated with a combination of tegafur and uracil (UFT). Eighty-two carcinomas were TS-positive, 105 carcinomas were OPRT-positive, 68 carcinomas were DPD-positive. No correlation was observed in the HSCORE between the TS and OPRT expression (r=0.203), between the TS and DPD expression (r=0.098), or between the OPRT and DPD expression (r=0.074). Regarding the survival of NSCLC patients treated with UFT, the 5-year survival rate of patients with TS-negative tumours was significantly higher than that with TS-positive tumours (P=0.0133). The 5-year survival rate of patients with OPRT-positive stage II to III tumours was significantly higher than that with OPRT-negative stage II to III tumours (P=0.0145). In addition, the 5-year survival rate of patients with DPD-negative tumours was also significantly higher than that with DPD-positive tumours (P=0.0004). A Cox multivariate regression analysis revealed the TS status (hazard ratio 2.663; P=0.0003), OPRT status (hazard ratio 2.543; P=0.0005), and DPD status (hazard ratio 2.840; P<0.0001) to all be significant prognostic factors for the survival of resected NSCLC patients postoperatively treated with UFT.

Pegylated liposomal doxorubicin and platinum in patients with advanced ovarian cancer in late relapse (>6 months)

15035

Background: Platinum and doxorubicin have different mechanisms of action, show no cross-resistance, and their toxicities do not overlap. Because pegylated liposomaI doxorubicin (Lipo-Dox was manufactured by TTY Biopharm Company Ltd. in Taiwan) appears to be a promising form of delivering doxorubicin with decrease of some of the most problematic toxicities, a combination with platinum should be assessed. Methods: An open-label, non-comparative, single center phase II clinical trial. Eligible patients must have histologically proven advance ovarian cancer with two-dimensioned measurable disease or evaluable disease (defined as CA-125 ≥ 40 U/ml), who have been treated with one or two previous platinum- and taxane-based regimen. All patients will hospitalize for 24 hours for treatment. The dose of platinum is fixed (cisplatin at 75 mg/m2 or carboplatin at AUC=5) on D1 and the initial dose of pegylated liposomaI doxorubicin (Lipo-Dox) is 35 mg/m2 on D2 at a 4-week interval. Results: Twenty patients were enrolled from July 2002 to January 2004 and follow up until June 2004. All eligible patients are assessable for response and toxicity. The overall response rate was 80%. Of the 20 patients eligible for response evaluation, 10 (50%) patients had a complete response, 6 (30%) had partial response, 3 (15%) were with stable disease, and 1 (5%) showed progressive disease. An overall response (OR) was achieved in 80% of patients. In patients achieving an OR based on WHO criteria, median CA125 levels declined from 142 U/ml (range, 13–3670 U/ml) during the baseline to 26.5 U/ml (range, 5–375 U/ml) during the last cycle. Median time to response was 65 days (range, 12–188 days). Median duration of response was 471 days (range 146–1085 days). Furthermore, the median time to progression was 481 days (range, 138–1136 days). The main toxicity was myelosuppression, with grade 3 and 4 neutropenia in 3 patients, anemia in 4 patients, and leukopenia in 2 patients. Conclusions: Based on effectiveness and toxicity advantages, the combination of pegylated liposomaI doxorubicin (Lipo-Dox) and platinum should be considered in patients with advanced ovarian cancer in late relapse.

No significant financial relationships to disclose.

Hypogammaglobulinemia increases the risk of chemotherapy associated febrile neutropenia in patients with chronic lymphocytic leukemia

18549

Background: Infections are the major cause of morbidity and mortality in patients with chronic lymphocytic leukemia (CLL). Hypogammaglobulinemia, in general, increases the susceptibility to infections in patients with CLL. We conducted a case-control study to investigate whether hypogammaglobulinemia (Immunoglobulin-G (IgG) level <600 mg/dL) increases the risk of febrile neutropenic episodes in CLL patients with chemotherapy associated neutropenia (absolute neutrophil count (ANC) <0.5 × 109/L). Methods: The source cohort consisted of all consecutive patients with CLL seen at our institution between Jan 2002 to June 2005.We identified 8 cases of chemotherapy associated febrile neutropenia; controls consisted of 18 patients, with neutropenia but no fever (n = 4) or no neutropenia (n = 14). Results: The two groups were comparable except for a higher proportion of patients with Rai stage-4 disease in the febrile neutropenia cohort (100% vs. 17%, p < 0.001). Eight of the 8 patients in febrile neutropenia group were found to be hypogammaglobulinemic as compared to 2 of 18 controls (100% vs 11%, P value < 0.001). The median IgG level was 400 mg/dL (range, 300–488 mg/dL) in the febrile neutropenia group compared to 820 mg/dL (range, 121–1700 mg/dL) in the control group (p = 0.003).The relative risk of developing chemotherapy associate febrile neutropenia in the presence of underlying hypogammaglobulinemia was 4.5 (95% confidence intervals, 1.9–10.7). Conclusions: Patients with CLL who are hypogammaglobulinemic are candidates for prophylactic administration of intravenous immune-globulin prior to initiation of myelosuppressive chemotherapy.

[Table: see text]

No significant financial relationships to disclose.

Patients with stage IV lung cancer lose 25% of their valuable time in the office visits and hospital stay

18533

Background: Patients with stage IV lung cancer have median survival of 4–6 months. Randomized trials have shown chemotherapy may have small but significant survival benefit. To achieve this small gain,patients may have to spend their last few days of life in the office visits and hospitalization. Last few days of person’s life need to be spent comfortably and most effective manner in accordance to their wishes, desires and priorties.We attempted to study the “Time Lost” in the stage IV lung cancer patients who either did not choose or were not offered the palliative care/Hospice. Methods: We retrospectively reviewed charts of patients diagnosed with stage IV lung cancer (at their initial presentation) from Jan 2002 to Dec 2005 at our institution. We calculated their inpatient and out patient visit hrs and hence “Time Lost” during the last few days of their life. Patients were divided into two groups—Group A (n = 12): Patients who opted to choose palliative/hospice care immediately after the diagnosis and GroupB (n = 46): Patients who either refused or were not offered palliative/hospice care. Results: The median age at diagnosis was similar in both groups (71 vs 69.5 yrs). The median survival was also similar in both groups (4 months vs 4 months). Patients in group B (non hospice) had 1 month “Lost Time” out of their median survival of 4 months. In comparison patients in group A (hospice) had median survival of 4 months with “No Lost Time”. Thus patients who were not offered hospice or refused hospice spent 25% of their precious time during last stages of their life in inpatient stays and outpatient visits. Conclusions: Patients with stage IV lung cancer should be actively offered palliative/Hospice care, though studies with large number of patients is further required.

[Table: see text]

No significant financial relationships to disclose.

Prognostic factors for patients with metastatic urothelial carcinoma treated with cisplatin and 5-fluorouracil-based regimens

14583

Background: Combination of cisplatin and 5-fluorouracil (5-FU) has activity in metastatic urothelial carcinoma (UC). To identify patient subgroups most likely to benefit and compare survival to that in previously described patient series, long-term survival, as a function of known and suspected prognostic variables, was determined. Methods: The survival status of 79 patients with metastatic urothelial cancer treated on two phase II trials of cisplatin and 5-FU-based regimens was updated. P-HDFL regimen (n = 35) was cisplatin 35 mg/m2 IV 24hr D1, 8; 5-FU 2,600 mg/m2 and leucovorin 300 mg/m2 IV 24hr D1, 8, 15; repeated every 28 days (Cancer 2006, in press). TP-HDFL regimen (n = 44) was paclitaxel 70 mg/m2 IV 1hr D1, 8; cisplatin 35 mg/m2 IV 24hr D1, 8; 5-FU 2,000 mg/m2 and leucovorin 300 mg/m2 IV 24hr D1, 8; repeated every 21 days (Proc ASCO 22:407b, 2003 [abstr 1637]). Univariate and multivariate Cox proportional hazards models were constructed. Results: Karnofsky performance status (KPS) <80%, presence of visceral metastasis, and alkaline phosphatase ≥220 U/l are three significant poor prognostic factors for survival. The percentage of patients who harbored zero-risk, one- or two-risk, and three-risk categories was 27%, 61%, and 13%, respectively. Among patients with no risk factors, the median survival time was not reached yet after a median follow-up of 43.0 months. Patients with one or two risk factors had a median survival duration of 12.3 months (95% CI 8.6–16.0). Patients with all three risk factors had a median survival of 4.6 months (95% CI 1.4–7.9). There was a significant difference in survival between the three groups (P < .0001). Conclusions: Previously described prognostic factors, including KPS <80%, visceral metastasis, and alkaline phosphatase ≥220 U/l, for survival in metastatic UC were confirmed in patients treated with cisplatin and 5-FU-based regimen.

No significant financial relationships to disclose.

Phase II study of sequential non-cross-resistant chemotherapy using weekly 24-hour infusion of cisplatin, high-dose 5-fluorouracil and leucovorin (P-HDFL) followed by weekly docetaxel and irinotecan (DI) for recurrent or metastatic gastric cancer: an interim analysis

14063

Weekly 24-hour infusion of high-dose 5-FU and leucovorin (HDFL)-based regimens are highly effective for advanced gastric cancer (AGC). Although the response rate has been improved, the overall survival (OS) was not significantly prolonged. To prolong the OS, we designed a sequential chemotherapy strategy incorporating non-cross-resistant docetaxel and irinotecan (DI). All patients had patho/cytologically confirmed recurrent/metastatic chemonaive AGC, at least 1 measurable lesion, a fasting serum triglyceride level > 70 mg/dl, adequate hepatic, renal, and marrow functions. Induction regimen was P-HDFL (cisplatin 35 mg/m2, i.v. 24-hr, D1, 8; 5-FU 2600 mg/m2 and leucovorin 300 mg/m2, i.v. 24-hr, D1, 8, 15; every 4 wks), and consolidation regimen was weekly DI (docetaxel 30–35 mg/m2/wk, i.v. 30-min, then irinotecan 60–70 mg/m2/wk, i.v. 30-min, D1, 8, 15; every 4 wks). Patients with inferior conditions (prior Gr4 neutropenia or Gr3/4 infection, poor marrow reserve with delayed hemogram recovery, poor nutritional status or ileus) started with dose-modified DI (D: 30, I: 60 mg/m2/wk). For CR patients by P-HDFL, 3 cycles of DI were given; and for PR or SD patients, DI was continued till 2 cycles after CR, disease progression, or unacceptable toxicities. Between Jun. 2000 and Dec. 2005, 23 patients were enrolled (M:11, F:12) with a median age of 52 (37–68). Total 114 cycles (median: 6, range: 2–8) of P-HDFL were given. Overall RR was 60.9% (38–80%, 95% C.I.) with 3 CRs and 11 PRs. Gr3/4 toxicities: neutropenia (14%), infection (4.4%), thrombocytopenia (1.6%), diarrhea (5%), and vomiting (7%). Gr1/2 hand-foot syndrome was noted in 11% of cycles. Patients with CR, PR, and SD were treated with weekly DI regimen. Total 59 cycles (median: 4, range: 1–10) of weekly DI were given. Gr3/4 toxicities: neutropenia (30.5%), infection (13%), thrombocytopenia (2%), and diarrhea (17%). Median OS of the whole intent-to-treat group is 18 months (3 to 62+), and median OS of 14 responders of P-HDFL is 20 months (7 to 62+). This sequential non-cross-resistant strategy is very effective for prolongation of OS in advanced AGC.

No significant financial relationships to disclose.

Phase II trial of cisplatin (C), etoposide (E) and radiation (RT) followed by gemcitabine (G) vs G and docetaxel (D) in stage III A/B unresectable non-small cell lung cancer (NSCLC)

7120

Background: SWOG 9504 demonstrated the benefit of D consolidation after E + C with radiation therapy in pts with locally advanced NSCLC. This study was developed to assess the feasibility and efficacy of consolidation with either G alone or with D after the same chemoradiation schedule as SWOG 9504. Methods: The treatment schema included concurrent C 50 mg/m2 Day 1, 8 + E 50 mg/m2 Day 1–5 for two 28-day cycles + RT 180 cGy daily for 7 weeks after which pts were randomized to consolidation treatment of either G 1000 mg/m2 Day 1, 8 (Arm A) or G 1000 mg/m2 Day 1, 8 + D 75 mg/m2 Day 1 (Arm B) every 21 days for 3 cycles. Forty-six pts have been accrued; data is currently available in 28. Conclusions: Preliminary data indicate that G or G + D following chemoradiation in locally advanced NSCLC is well tolerated. The doublet, as expected, results in more toxicity, particularly myelosuppression and fatigue. Response, survival and TTP data will be presented at the time of the meeting.

[Table: see text]

[Table: see text]

[Combined large cell neuroendocrine carcinoma and squamous cell carcinoma of the lung; report of a case]

An 80-year-old man was admitted to our hospital because a routine chest X-ray had revealed a nodular shadow in the right lower lung field. Transbronchial lung biopsy (TBLB) failed to give at definitive diagnosis, therefore open lung biopsy was performed because of suspected lung cancer. Rapid intraoperative pathological examination diagnosed the tumor as large cell carcinoma. However, bloody pleural effusion was classified as class V. It was judged difficult to perform a curative operation, so the operation was interrupted. Pathological diagnosis was combined large cell neuroendocrine carcinoma and squamous cell carcinoma. Pleurodesis was done, and the patient is under observation at 7 months after the operation.

Association of intercellular adhesion molecule 1 polymorphisms with retinopathy in Chinese patients with Type 2 diabetes

AIMS

To investigate the relationship of the K469E and G241R polymorphisms of the intercellular adhesion molecule 1 (ICAM-1) gene with diabetic retinopathy in Chinese patients with Type 2 diabetes mellitus.

PATIENTS AND METHODS

One hundred and seventy-two Chinese patients with Type 2 diabetes and 80 normal control subjects were recruited. Patients with diabetes were placed into two groups: the diabetic retinopathy (DR) group and the non-diabetic retinopathy (NDR) group. The DR group was subdivided into those with proliferative retinopathy (PDR) and non-proliferative retinopathy (NPDR). Genomic DNA was prepared using the hydroxybenzene-chloroform extraction method. Genotypes and alleles were detected by polymerase chain reaction-heteroduplex-single-strand conformation polymorphism (PCR-HA-SSCP) analysis combined with gene sequencing.

RESULTS

The patients with retinopathy had an increased frequency of the K469K genotype compared with both the patients without retinopathy and the control subjects (61.4 vs. 40.0 and 35.0%, respectively; chi(2) = 8.280 and 13.952, respectively; P < 0.05). The frequency of the K allele in the DR group was higher than in the NDR group and control subjects (75.4 vs. 58.8 and 61.3%, respectively; chi(2) = 9.693 and 11.219, respectively; P < 0.05). Genotype and allele frequencies were similar in the NDR group and control subjects, and in the PDR and NPDR groups.

CONCLUSION

The ICAM-1 gene K469E polymorphism is associated with diabetic retinopathy in Chinese patients with Type 2 diabetes. Patients with the K469K genotype were more likely to have diabetic retinopathy than patients with the K469E or E469E genotype.

The HAUSP gene plays an important role in non-small cell lung carcinogenesis through p53-dependent pathways

Herpesvirus-associated ubiquitin-specific protease (HAUSP) directly stabilizes the tumour suppressor p53 by de-ubiquitination. Therefore, the HAUSP gene might play an important role in carcinogenesis. In this paper, HAUSP expression and p53 gene status have been studied in relation to the expression of p53 target genes in 131 patients with non-small cell lung cancer (NSCLC). p53 gene status was evaluated by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) followed by sequencing. Quantitative reverse-transcription polymerase chain reaction (RT-PCR) was performed to evaluate the gene expression of HAUSP, p21, and bax. Immunohistochemistry was performed to evaluate the protein expression of p53, HAUSP, mdm2, p21, and bax. Fifty-nine carcinomas (45.0%) showed reduced expression of HAUSP, and 58 carcinomas (44.3%) had mutations of p53. Concerning tumour histology, HAUSP mRNA expression was significantly lower in adenocarcinomas than in squamous cell carcinomas (p = 0.0038), while the frequency of p53 mutation was significantly higher in squamous cell carcinomas than in adenocarcinomas (p = 0.0461). There was no significant difference in HAUSP mRNA expression according to p53 gene status. In total, 93 carcinomas (71.0%) showed either mutant p53 or reduced HAUSP expression. The down-regulation of HAUSP was associated with reduced p53 protein expression (p = 0.0593 in tumours with wild-type p53 and p = 0.0004 in tumours with mutant p53). Furthermore, p21 and bax protein expression was significantly lower in tumours with either mutant p53 or reduced HAUSP expression than in tumours with both wild-type p53 and positive HAUSP expression (p = 0.0440 and p = 0.0046, respectively). In addition, the simultaneous evaluation of both HAUSP expression and p53 gene status was a significant indicator of poor prognosis in adenocarcinoma patients (hazard ratio 4.840, p = 0.0357). These results suggest that reduction of HAUSP gene expression may play an important role in NSCLC carcinogenesis, especially in adenocarcinomas, through p53-dependent pathways.

Nonlinear theory for relativistic plasma wakefields in the blowout regime

We present a theory for nonlinear, multidimensional plasma waves with phase velocities near the speed of light. It is appropriate for describing plasma waves excited when all electrons are expelled out from a finite region by either the space charge of a short electron beam or the radiation pressure of a short intense laser. It works very well for the first bucket before phase mixing occurs. We separate the plasma response into a cavity or blowout region void of all electrons and a sheath of electrons just beyond the cavity. This simple model permits the derivation of a single equation for the boundary of the cavity. It works particularly well for narrow electron bunches and for short lasers with spot sizes matched to the radius of the cavity. It is also used to describe the structure of both the accelerating and focusing fields in the wake.

Experimental determination of the helium-metal interaction potential by interferometry of nanostructured surfaces

We present a direct experimental comparison of the helium-surface interaction potential for two unreconstructed metal surfaces. We analyze phase shifts in helium atom scattering from a nanostructured bimetallic surface to yield the relative shape and position of an adsorbate's potential with respect to the reference defined by the substrate. In our prototype system, submonolayer growth of Ni on Cu(100), the He-Ni/Cu(100) potential has an attractive well that is 1.6+/-0.4 meV shallower, and a repulsive wall 0.11+/-0.03 A closer to the ion cores, compared to the He-Cu(100) potential. Our observations provide a ready test of state-of-the-art theoretical calculations.

Dredging of drainage ditches increases short-term transport of soluble phosphorus

Managed drainage ditches are common in the midwestern United States. These ditches are designed to remove water from fields as quickly as possible, and sediment buildup necessitates dredging, to ensure adequate water removal. This laboratory study was conducted to determine the impact of ditch dredging on soluble phosphorus (P) transport. Ditch sediments were collected from a drainage ditch in northeastern Indiana immediately before and after dredging. The sediments were placed in a stream simulator, and stream water was loaded with 0.55 mM P for 5 d (adsorption experiment). Water was then removed, and "clean" water (no P added) was used for a desorption experiment, lasting 1 d. During the adsorption experiment, pre-dredged sediments were able to remove P from the water column quicker, and P concentrations 120 h after introduction of high P water were lower for the pre-dredged sediments (0.075 mM P) than the dredged sediments (0.111 mM P). During the desorption experiment, P was released to the water column slower in the pre-dredged treatment than the dredged treatment (instantaneous flux at t = 0 was 0.205 microM P h(-1) for pre-dredged and 0.488 microM P h(-1) for dredged). This occurred despite higher Mehlich 3-extractable P in the pre-dredged sediments than the dredged sediments. Equilibrium phosphorus concentrations (EPCo) were lower in the pre-dredged sediments during both adsorption and desorption experiments. Transport of soluble P immediately after dredging will likely increase in drainage ditches; however, dredging is a necessary management tool to ensure adequate discharge of water from surrounding fields.

Hose instability and wake generation by an intense electron beam in a self-ionized gas

The propagation of an intense relativistic electron beam through a gas that is self-ionized by the beam's space charge and wakefields is examined analytically and with 3D particle-in-cell simulations. Instability arises from the coupling between a beam and the offset plasma channel it creates when it is perturbed. The traditional electron hose instability in a preformed plasma is replaced with this slower growth instability depending on the radius of the ionization channel compared to the electron blowout radius. A new regime for hose stable plasma wakefield acceleration is suggested.

Diagnostic accuracy of contrast-enhanced ultrasound in focal lesions of the liver using cadence contrast pulse sequencing

The purpose of this study was to assess the accuracy of Cadence Contrast Pulse Sequencing (Siemens-Acuson, CA) method with injection of SonoVue (Bracco Imaging SpA, Italy) for the detection and characterisation of focal liver lesions in comparison with a reference modality during routine use.

METHODS

138 consecutive patients (62 women, 76 men; mean age: 52 years for women and 63 years for men) corresponding to 144 examinations with 381 lesions participated in this prospective study from December 2002 to November 2003. Inclusion criteria were lesions detected by conventional US and the availability of a reference imaging examination (CT or MR imaging) within three weeks. The underlying liver lesions characterised by a reference modality (including biopsy in 29 lesions) were distributed as follows: haemangioma (n = 56), focal nodular hyperplasia (n = 27), hepatocellular carcinoma (n = 44), hepatocellular adenoma (n = 5), liver metastasis (n = 174), abscess (n = 2), cysts (n = 45), other benign lesions (n = 24) and 3 peritoneal metastases.

RESULTS

A significant improvement was reported in the number of detected lesions between contrast-enhanced ultrasound and baseline ultrasonography (351 lesions versus 280 lesions, respectively, p < 0.01), whereas no significant difference was noted between contrast-enhanced ultrasound and reference imaging (351 versus 377 lesions, respectively). On the whole, contrast-enhanced ultrasound allowed a complete diagnosis in 96 % of the detected nodules with a significant improvement compared to conventional sonography in which the diagnosis was suspected in only 52 % out of these cases (p < 0.001). No significant difference was noted between contrast-enhanced ultrasound and the reference modality concerning characterisation of nodules.

CONCLUSION

The present study clearly indicates that contrast-enhanced sonography using Sonovue and Cadence Contrast Pulse Sequencing allows real-time imaging with high accuracy and thus will be a competitive alternative to other modalities such as CT and MR imaging for liver imaging.

Parameter optimization and design aspect for electrocoagulation of silica nano-particles in wafer polishing wastewater

A systematic procedure has been proposed for the design of a multi-channel, continuous-flow electrocoagulation reactor of mono-polar configuration for the removal of sub-micron particles from wastewater. Using the chemical-mechanical-planarization (CMP) process as the target source of wastewater, a series of laboratory-scale studies were conducted to determine the required operating conditions for the efficient removal of the ultrafine particles. These operating criteria included charge loading (> or = 8 F m(-3)), current density (> or = 5.7 A m(-2)), hydraulic retention time (> or = 60 min), as well as the initially operational pH (7 to approximately 10). Furthermore, a steady-state transport equation with second-order reaction kinetics was employed to describe the rate of coagulation as the rate-limiting factor. The actual kinetic constant determined from the laboratory-scale experiments was approximately 1.2 x 10(-21) m3 s(-1), which was three orders of magnitude smaller than that calculated based on Brownian diffusion during the coagulation. The model was subsequently validated with a series of experiments using a pilot-scale electro-coagulation reactor geometrically similar to the laboratory-scale reactor with nearly twenty times volumetric scale-up.

Engulfed pathogen-induced apoptosis in haemocytes of giant freshwater prawn, Macrobrachium rosenbergii

Haemocytes of the giant freshwater prawn, Macrobrachium rosenbergii, were investigated for the induction of apoptosis after phagocytosis of pathogenic yeasts, bacteria and non-pathogenic latex beads in vitro. Isolated haemocytes of M. rosenbergii were cultured at a ratio of 1:50 haemocytes to pathogen with the yeast Debaryomyces hansenii, the bacteria Aeromonas hydrophila or Enterococcus faecium, or with latex beads at 25 degrees C for 2 h, followed by washing to remove free particles. At least 200 haemocytes were counted to determine the phagocytosis rate, and the results showed that haemocytes engulfed latex beads at a higher rate than the aquatic pathogens. By transmission electron microscopy, the yeast- or bacterium-engulfing haemocytes displayed morphological changes characteristic of apoptosis, including formation of cytoplasmic vacuoles, chromatin condensation and fragmentation of nuclei. This pathogen-induced apoptosis was further confirmed by DNA laddering and TUNEL (terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick-end-labelling) assays. Neither haemocytes treated with latex beads nor uninfected haemocytes (control group) showed signs of apoptosis after 48 h in culture.

Oxidative damage in cerebral vessels of diabetic db/db mice

BACKGROUND

Oxidative stress in diabetes mellitus has recently received increasing attention as it has been proven to be associated with the development of diabetic vascular complications. Our aim was to examine whether microvascular changes, including oxidative damage, were induced in the brains of diabetic animals.

METHODS

The expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, the binding of cationized ferritin, a marker for evaluating endothelial glycocalyx, to the endothelial cells of capillaries and vascular permeability of intravenously injected horseradish peroxidase were examined in the cortices of 12- and 20-week-old db/db and db/+m mice.

RESULTS

Immunostaining for 8-OHdG was clearly seen in the vessels of the cortex of 20-week-old db/db mice, but was hardly seen in those of mice in the other groups. The immunopositive area of 8-OHdG was significantly increased in the cortex of 20-week-old db/db mice compared with that of 20-week-old db/+m mice. No extravasated leakage of horseradish peroxidase was seen in any groups of mice, while the numbers of cationized ferritin particles binding to the endothelial cells was significantly decreased in 12- and 20-week-old db/db mice compared with that of db/+m mice at the same age, respectively.

CONCLUSION

These findings suggest that changes in endothelial glycocalyx are induced in db/db mice and, in addition, the long-term diabetic condition of these mice induces oxidative DNA damage to the cerebral vessels.

Subzero water permeability parameters and optimal freezing rates for sperm cells of the southern platyfish, Xiphophorus maculatus

This study reports the subzero water transport characteristics (and empirically determined optimal rates for freezing) of sperm cells of live-bearing fishes of the genus Xiphophorus, specifically those of the southern platyfish Xiphophorus maculatus. These fishes are valuable models for biomedical research and are commercially raised as ornamental fish for use in aquariums. Water transport during freezing of X. maculatus sperm cell suspensions was obtained using a shape-independent differential scanning calorimeter technique in the presence of extracellular ice at a cooling rate of 20 degrees C/min in three different media: (1) Hanks' balanced salt solution (HBSS) without cryoprotective agents (CPAs); (2) HBSS with 14% (v/v) glycerol, and (3) HBSS with 10% (v/v) dimethyl sulfoxide (DMSO). The sperm cell was modeled as a cylinder with a length of 52.35 microm and a diameter of 0.66 microm with an osmotically inactive cell volume (Vb) of 0.6 V0, where V0 is the isotonic or initial cell volume. This translates to a surface area, SA to initial water volume, WV ratio of 15.15 microm(-1). By fitting a model of water transport to the experimentally determined volumetric shrinkage data, the best fit membrane permeability parameters (reference membrane permeability to water at 0 degrees C, Lpg or Lpg [cpa] and the activation energy, E(Lp) or E(Lp) [cpa]) were found to range from: Lpg or Lpg [cpa] = 0.0053-0.0093 microm/minatm; E(Lp) or E(Lp) [cpa] = 9.79-29.00 kcal/mol. By incorporating these membrane permeability parameters in a recently developed generic optimal cooling rate equation (optimal cooling rate, [Formula: see text] where the units of B(opt) are degrees C/min, E(Lp) or E(Lp) [cpa] are kcal/mol, L(pg) or L(pg) [cpa] are microm/minatm and SA/WV are microm(-1)), we determined the optimal rates of freezing X. maculatus sperm cells to be 28 degrees C/min (in HBSS), 47 degrees C/min (in HBSS+14% glycerol) and 36 degrees C/min (in HBSS+10% DMSO). Preliminary empirical experiments suggest that the optimal rate of freezing X. maculatus sperm in the presence of 14% glycerol to be approximately 25 degrees C/min. Possible reasons for the observed discrepancy between the theoretically predicted and experimentally determined optimal rates of freezing X. maculatus sperm cells are discussed.

Reduction of insulin-stimulated glucose uptake in L6 myotubes by the protein kinase inhibitor SB203580 is independent of p38MAPK activity

Insulin increases glucose uptake through translocation of the glucose transporter GLUT4 to the plasma membrane. We previously showed that insulin activates p38MAPK, and inhibitors of p38MAPKalpha and p38MAPKbeta (e.g. SB203580) reduce insulin-stimulated glucose uptake without affecting GLUT4 translocation. This observation suggested that insulin may increase GLUT4 activity via p38alpha and/or p38beta. Here we further explore the possible participation of p38MAPK through a combination of molecular strategies. SB203580 reduced insulin stimulation of glucose uptake in L6 myotubes overexpressing an SB203580-resistant p38alpha (drug-resistant p38alpha) but barely affected phosphorylation of the p38 substrate MAPK-activated protein kinase-2. Expression of dominant-negative p38alpha or p38beta reduced p38MAPK phosphorylation by 70% but had no effect on insulin-stimulated glucose uptake. Gene silencing via isoform-specific small interfering RNAs reduced expression of p38alpha or p38beta by 60-70% without diminishing insulin-stimulated glucose uptake. SB203580 reduced photoaffinity labeling of GLUT4 by bio-LC-ATB-BMPA only in the insulin-stimulated state. Unless low levels of p38MAPK suffice to regulate glucose uptake, these results suggest that the inhibition of insulin-stimulated glucose transport by SB203580 is likely not mediated by p38MAPK. Instead, changes experienced by insulin-stimulated GLUT4 make it susceptible to inhibition by SB203580.