PLA2 (group IIA phospholipase A2) as a prognostic determinant in stage II colorectal carcinoma

BACKGROUND

Approximately 30% of all colorectal cancer (CRC) patients are diagnosed with stage II disease. Adjuvant therapy is not widely recommended. However, it is well established that a subgroup of patients with stage II are at high risk for recurrence within their lifetime and should be considered for adjuvant chemotherapy. The present work was designed to assess the value of group IIA phospholipase A2 (PLA2) as a predictor of disease outcome in stage II CRC patients with long-term follow-up.

PATIENTS AND METHODS

The present study comprises a series of 116 patients who underwent bowel resection for stage II CRC during 1981-1990 at Turku University Hospital. Archival paraffin-embedded CRC tissue samples were used to prepare tissue microarray blocks for immunohistochemical staining with PLA2.

RESULTS

Fifty-five percent of all tumors were positive for PLA2. There was no significant correlation between PLA2 expression and age, sex, depth of invasion and lymph node status. In Kaplan-Meier survival analysis, there was a significant (P = 0.010) difference in disease-free survival (DFS) between patients with negative tumors (longer DFS) and those with positive tumors. The same was true with disease-specific survival (DSS), patients with PLA2-negative tumors living significantly longer (P = 0.025). In multivariate (Cox) survival analysis, however, PLA2 was not an independent predictor of DFS or DSS. In subgroup analysis, the right-sided tumors with negative PLA2 staining had remarkably better prognosis (P = 0.010) than PLA2-positive left-sided tumors.

CONCLUSIONS

Quantification of PLA2 expression seems to provide valuable prognostic information in stage II CRC, particularly in selecting the patients at high risk for recurrent disease who might benefit from adjuvant therapy.

Enzymatic hydrolysis of native cellulose nanofibrils and other cellulose model films: effect of surface structure

Model films of native cellulose nanofibrils, which contain both crystalline cellulose I and amorphous domains, were used to investigate the dynamics and activities of cellulase enzymes. The enzyme binding and degradation of nanofibril films were compared with those for other films of cellulose, namely, Langmuir-Schaefer and spin-coated regenerated cellulose, as well as cellulose nanocrystal cast films. Quartz crystal microbalance with dissipation (QCM-D) was used to monitor the changes in frequency and energy dissipation during incubation at varying enzyme concentrations and experimental temperatures. Structural and morphological changes of the cellulose films upon incubation with enzymes were evaluated by using atomic force microscopy. The QCM-D results revealed that the rate of enzymatic degradation of the nanofibril films was much faster compared to the other types of cellulosic films. Higher enzyme loads did not dramatically increase the already fast degradation rate. Real-time measurements of the coupled contributions of enzyme binding and hydrolytic reactions were fitted to an empirical model that closely described the cellulase activities. The hydrolytic potential of the cellulase mixture was found to be considerably affected by the nature of the substrates, especially their crystallinity and morphology. The implications of these observations are discussed in this report.

Heme oxygenase 1 gene polymorphisms and outcome of renal transplantation

Heme oxygenase isoenzyme HO-1 has been linked to several cytoprotective functions with a potentially beneficial role in transplantation. In the present study, the effect of genetic variation in HO-1 on renal allograft outcome was investigated. Six hundred and eighty patients subject to renal transplantation in a single transplant unit and their cadaveric kidney donors were included in this study. Four single-nucleotide polymorphisms and one microsatellite marker in the HO-1 gene region were analysed. Some statistically nominally significant associations were observed in preliminary analyses between polymorphisms studied and clinical outcomes, but after correction for multiple comparisons none remained significant. Our data suggest that the HO-1 gene polymorphisms studied have no significant role on outcome of kidney transplantation in the Finnish population.

Enzymatic hydrolysis combined with mechanical shearing and high-pressure homogenization for nanoscale cellulose fibrils and strong gels

Toward exploiting the attractive mechanical properties of cellulose I nanoelements, a novel route is demonstrated, which combines enzymatic hydrolysis and mechanical shearing. Previously, an aggressive acid hydrolysis and sonication of cellulose I containing fibers was shown to lead to a network of weakly hydrogen-bonded rodlike cellulose elements typically with a low aspect ratio. On the other hand, high mechanical shearing resulted in longer and entangled nanoscale cellulose elements leading to stronger networks and gels. Nevertheless, a widespread use of the latter concept has been hindered because of lack of feasible methods of preparation, suggesting a combination of mild hydrolysis and shearing to disintegrate cellulose I containing fibers into high aspect ratio cellulose I nanoscale elements. In this work, mild enzymatic hydrolysis has been introduced and combined with mechanical shearing and a high-pressure homogenization, leading to a controlled fibrillation down to nanoscale and a network of long and highly entangled cellulose I elements. The resulting strong aqueous gels exhibit more than 5 orders of magnitude tunable storage modulus G' upon changing the concentration. Cryotransmission electron microscopy, atomic force microscopy, and cross-polarization/magic-angle spinning (CP/MAS) 13C NMR suggest that the cellulose I structural elements obtained are dominated by two fractions, one with lateral dimension of 5-6 nm and one with lateral dimensions of about 10-20 nm. The thicker diameter regions may act as the junction zones for the networks. The resulting material will herein be referred to as MFC (microfibrillated cellulose). Dynamical rheology showed that the aqueous suspensions behaved as gels in the whole investigated concentration range 0.125-5.9% w/w, G' ranging from 1.5 Pa to 105 Pa. The maximum G' was high, about 2 orders of magnitude larger than typically observed for the corresponding nonentangled low aspect ratio cellulose I gels, and G' scales with concentration with the power of approximately three. The described preparation method of MFC allows control over the final properties that opens novel applications in materials science, for example, as reinforcement in composites and as templates for surface modification.

Ionically self-assembled carboxymethyl cellulose/surfactant complexes for antistatic paper coatings

We show that ionically self-assembled polyelectrolyte/surfactant complexes allow a facile route to tailor the electrical surface resistance of paper sheets for antistatic dissipative regime. We use anionic polyelectrolyte carboxymethyl cellulose (CMC) where cationic alkyltrimethylammonium chloride surfactants (C(n)TAC) with the alkyl chain lengths n=12, 14 or 16 methyl units are ionically complexed by precipitation from aqueous solutions. Such alkyl chains are sufficiently long to allow self-assembly in solid films after solvent evaporation. Short chain lengths, e.g., n=8, did not lead to precipitation. Small angle X-ray scattering indicates cylindrical self-assembly in bulk samples. Upon exposing bulk samples under humidity of 50% RH for 18 h, conductivity of ca. 10(-5) S/cm at room temperature is achieved based on AC-impedance analysis. Flexographic printing and spray coating were selected to conceptually test the feasibility as paper coatings and surface sheet resistances of ca. 10(9) Omega are reached. The results indicate that self-assembled polyelectrolyte/surfactant complexes can allow sufficient conductivity levels for antistatic paper coatings potentially due to protonic conductivity and suggest to develop processes and materials for realistic applications.

Preoperative hyperfractionated accelerated radiotherapy and radical surgery in advanced head and neck cancer: A prospective phase II study

BACKGROUND AND PURPOSE

To evaluate whether preoperative hyperfractionated accelerated radiotherapy (RT) combined with major radical surgery is feasible and successful in the treatment of advanced primary head and neck cancer.

PATIENTS AND METHODS

Ninety four patients with histologically confirmed head and neck squamous cell cancer (HNSCC) in the oral cavity (41/96; 43%), supraglottis (14/96; 15%), glottis (5/96; 5%), oropharynx (16/96; 17%), nasal cavity/paranasal sinuses (8/96; 8%), nasopharynx (3/96; 3%), hypopharynx (7/96; 7%) and two (2%) with unknown primary tumour and large cervical lymph nodes entered into the study. 21/96 patients (22%) had stage II, 17/96 (18%) stage III and 58/96 patients (60%) stage IV disease. The patients received preoperative hyperfractionated RT 1.6 Gy twice a day, 5 days a week to a median tumour dose of 63 Gy with a planned break for 11 days (median) after the median dose of 37 Gy. Then, after a median of 27 days the patients underwent major radical surgery of the primary tumour and metastatic lymph nodes including reconstructions with pedicled or microvascular free flaps when indicated as a part of the scheduled therapy. 12/96 patients had only ipsilateral or bilateral neck dissections.

RESULTS

After a median follow-up time of 37.2 mos 77/96 (80.2%) patients had complete locoregional control. All but 2 patients had complete histological remission after surgery. 40/96 pts were alive without disease, two of them after salvage surgery. 32/96 patients had relapsed; 15 had locoregional and 13 distant relapses, 4 patients relapsed both locoregionally and distantly. Fifty patients have died; 29 with locoregional and/or distant relapse, eight patients died of second malignancy, and 19 had intercurrent diseases. Disease-specific and overall survival at 3 years was 67.7 and 51%, respectively. Acute grade three mucosal reactions were common, but transient and tolerable. Late grade 3-4 adverse effects were few.

CONCLUSIONS

Preoperative hyperfractionated accelerated RT can be successfully combined with major radical surgery in the treatment of HNSCC. The amount of serious late adverse effects was not increased.

Methane-oxidizing bacteria in a Finnish raised mire complex: effects of site fertility and drainage

Methane-oxidizing bacteria (MOB) are the only biological sinks for methane (CH4). Drainage of peatlands is known to decrease overall CH4 emission, but the effect on MOB is unknown. The objective of this work was to characterize the MOB community and activity in two ecohydrologically different pristine peatland ecosystems, a fen and a bog, and their counterparts that were drained in 1961. Oligotrophic fens are groundwater-fed peatlands, but ombrotrophic bogs receive additional water and nutrients only from rainwater. The sites were sampled in August 2003 down to 10 cm below the water table (WT), and cores were divided into 10-cm subsamples. CH4 oxidation was measured by gas chromatography (GC) to characterize MOB activity. The MOB community structure was characterized by polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) and sequencing methods using partial pmoA and mmoX genes. The highest CH4 oxidation rates were measured from the subsamples 20-30 and 30-40 cm above WT at the pristine oligotrophic fen (12.7 and 10.5 micromol CH4 dm-3 h-1, respectively), but the rates decreased to almost zero in the vicinity of WT. In the pristine ombrotrophic bog, the highest oxidation rate at 0-10 cm was lower than in the fen (8.10 micromol CH4 dm-3 h-1), but in contrast to the fen, oxidation rates of 4.5 micromol CH4 dm-3 h-1 were observed at WT and 10 cm below WT. Drainage reduced the CH4 oxidation rates to maximum values of 1.67 and 5.77 micromol CH4 dm-3 h-1 at 30-40 and 20-30 cm of the fen and bog site, respectively. From the total of 13 pmoA-derived DGGE bands found in the study, 11, 3, 6, and 2 were observed in the pristine fen and bog and their drained counterparts, respectively. According to the nonmetric multidimensional scaling of the DGGE banding pattern, the MOB community of the pristine fen differed from the other sites. The majority of partial pmoA sequences belonged to type I MOB, whereas the partial mmoX bands that were observed only in the bog sites formed a distinct group relating more to type II MOB. This study indicates that fen and bog ecosystems differ in MOB activity and community structure, and both these factors are affected by drainage.

Low Collagenase-1 (MMP-1) and MT1-MMP Expression Levels Are Favourable Survival Markers in Advanced Colorectal Carcinoma

OBJECTIVE

Extracellular matrix degradation is required for invasive growth and metastasis formation in colorectal carcinoma; therefore, we examined matrix metalloproteinases expression (MMP-1, MMP-13 and MT1-MMP) and apoptosis in tumours from 49 patients with advanced colorectal disease.

METHODS

MMP expression was determined immunohistochemically and apoptotic index (AI) was ascertained using the TUNEL assay.

RESULTS

Low levels of MT1-MMP, MMP-1 and AI were found to be favourable markers significantly associated with longer survival. MT1-MMP expression levels below the median (</=14.0% of tumour cells) were associated with better overall survival (median 26.2 vs. 15.6 months, p = 0.02) and MMP-1 expression levels below the median (</=28.7% of tumour cells) correlated with longer survival following metastasis (median 21.5 vs. 13.3 months, p = 0.05). MT1-MMP, MMP-1 and AI were all found to have significant independent effects on survival. Interestingly, MMP-1 expression levels above the median were associated with distal disease of the colon (p = 0.02).

CONCLUSIONS

These findings reveal that MT1-MMP and MMP-1 expression levels and AI are useful prognostic indicators in advanced colorectal carcinoma and suggest that markers of MMP expression might be used in identifying patients who would benefit from new treatment modalities involving MMP inhibitors.

Apoptotic index and bcl-2 expression as prognostic factors in colorectal carcinoma

OBJECTIVES

To examine programmed cell death in 57 colorectal carcinomas (49 primary tumours and 8 metastases) and determine the prognostic significance of apoptosis in colorectal cancer.

METHODS

Apoptotic index (AI) was ascertained by counting apoptotic bodies, using terminal deoxynucleotidyl transferase mediated digoxigenin nick end labelling (Tunel assay) and the expression of bcl-2 was examined immunohistochemically. Statistical analysis was used to test the value of clinical variables, histopathological data, AI and bcl-2 expression in predicting the clinical outcome of these patients and the survival function was calculated using the Kaplan-Meier method.

RESULTS

AI was found to have a significant independent effect on survival (p = 0.0006), with lower values of AI conveying better survival.

CONCLUSION

In summary, these findings reveal that AI is a useful prognostic factor in colorectal carcinoma.

Instantaneous beat-to-beat variability reflects vagal tone during hyperbaric hyperoxia

Hyperbaric hyperoxia affects heart rate variability (HRV) by increasing parasympathetic activity. The purpose of this study was to evaluate the applicability of instantaneous beat-to-beat variability (SD1 of Poincaré plot analysis) in detecting changes in vagal tone and to evaluate possible changes in the fractality of heart rate dynamics (alpha1 of detrended fluctuation analysis) during hyperbaric hyperoxia. Continuous three-lead ECG recordings were taken in ten divers who were treated at 2.5 ATA with air (PO2 47 kPa) and oxygen (PO2 235 kPa) for 60 min. Power spectral analysis, Poincaré plot analysis and alpha1 were analyzed before compression, after 30 min and after 55 min at 2.5 ATA. Correlations between the variables were calculated after 55 min exposure. SD1 and high frequency (HF) power increased significantly but alpha1 decreased during hyperbaric hyperoxia (PO2 235 kPa). HF power and SD1 also correlated significantly. However, HF power and SD1 correlated inversely with alpha1. During hyperbaric hyperoxia, SD1 reflects vagal activity and can be used instead of HF power, if stationary conditions cannot be achieved. The decreasing alpha1 indicates more random heart rate dynamics during hyperbaric hyperoxia.

Rehabilitation of patients with congenital unrepaired cleft palate defects using free iliac crest bone grafts and dental implants

PURPOSE

To rehabilitate the mastication and speech of edentulous congenital cleft lip and palate patients with the use of endosseous implants in conjunction with bone augmentation.

MATERIALS AND METHODS

Between 1992 and 1999, 6 partially and 4 completely edentulous adult patients with complex cleft palate defects were treated. Six patients had large, unrepaired defects of the hard and soft palate, whereas the other 4 had residual oronasal fistulas after failed palatoplasty and bone grafting. In 8 patients, free inlay-antral and simultaneous lateral-onlay bone grafts (3 patients) were obtained from the iliac crest, and dental implants were placed secondarily. In the other 2 patients, the implants were placed without grafting in recent extraction sites. Rigid bars with extensions over the defects were used to support obturator prostheses (n = 7), or patients were provided with fixed implant-supported prostheses (n = 3). In all, 50 cylindric, screw-type dental implants were placed and followed up for 1 to 8 years (mean, 5 years).

RESULTS

Six implants were regarded as early failures and 1 was lost during the first year of loading; 1 patient lost all 5 implants. The cumulative success rate at 5 years was 85.7%.

DISCUSSION AND CONCLUSION

All 9 successfully rehabilitated patients reported a remarkable functional and psychologic improvement after the treatment. The described treatment protocol also seemed to be effective for correcting velopharyngeal insufficiency in patients using an obturator prosthesis.

Cephalometric evaluation of facial types in preschool children without sleep-related breathing disorder

OBJECTIVE

this study was aimed at characterizing the craniofacial structures, i.e. the facial skeleton, cranial base, dentition, pharyngeal airway space, and the hyoid bone position, in healthy preschool children without sleep-related breathing disorder.

MATERIALS AND METHODS

from lateral cephalometric radiographs taken of 92 children for diagnostic purposes, 45 were selected for the present investigation on the basis of head position, and divided according to the classification of Siriwat and Jarabak (Angle Orthod. 55 (1985) 127) into groups representing counter-clockwise (CC), straight downward (SD), and clockwise (C) facial types.

RESULTS

the findings showed that, in comparison with the other groups, CC is associated with larger facial taper and posterior facial height, smaller mandibular line angle, ramus position, lower facial height and cranial base angle. By a similar comparison, C is associated with larger mandibular line, gonial angles and convexity, and with a smaller L-1 to mandibular line angle. There were no significant differences in hyoid bone position among the three groups. However, the distance of the lower pharynx was smaller in CC than in C, while the tongue base of CC was noted to be in a posterior position.

CONCLUSIONS

thus, the results indicate that there are significant differences in the madibular position and form among the present three groups of children. It is proposed that the objective of vertical facial control ought to be included in the treatment of preschool children with malocclusion and respiratory disorder.

Aromatic hydrocarbon receptor-driven Bax gene expression is required for premature ovarian failure caused by biohazardous environmental chemicals

Polycyclic aromatic hydrocarbons (PAHs) are toxic chemicals released into the environment by fossil fuel combustion. Moreover, a primary route of human exposure to PAHs is tobacco smoke. Oocyte destruction and ovarian failure occur in PAH-treated mice, and cigarette smoking causes early menopause in women. In many cells, PAHs activate the aromatic hydrocarbon receptor (Ahr), a member of the Per-Arnt-Sim family of transcription factors. The Ahr is also activated by dioxin, one of the most intensively studied environmental contaminants. Here we show that an exposure of mice to PAHs induces the expression of Bax in oocytes, followed by apoptosis. Ovarian damage caused by PAHs is prevented by Ahr or Bax inactivation. Oocytes microinjected with a Bax promoter-reporter construct show Ahr-dependent transcriptional activation after PAH, but not dioxin, treatment, consistent with findings that dioxin is not cytotoxic to oocytes. This difference in the action of PAHs versus dioxin is conveyed by a single base pair flanking each Ahr response element in the Bax promoter. Oocytes in human ovarian biopsies grafted into immunodeficient mice also accumulate Bax and undergo apoptosis after PAH exposure in vivo. Thus, Ahr-driven Bax transcription is a novel and evolutionarily conserved cell-death signaling pathway responsible for environmental toxicant-induced ovarian failure.

Dexamethasone treatment attenuates pulmonary injury in piglet meconium aspiration

To investigate the pulmonary effects of steroid treatment in neonates with meconium aspiration, 25 10- to 12-d-old piglets were studied for 6 h after an intratracheal bolus of human meconium. Dexamethasone (0.5 mg/kg) was given in two treatment schedules, either 1 h before (n = 6) or 1 h after meconium instillation (n = 8). Eight piglets served as controls. Three additional piglets were given dexamethasone without meconium instillation. Pulmonary hemodynamics and oxygenation were followed, and lung tissue samples investigated for signs of inflammation and ultrastructural injury, including apoptosis. Pulmonary artery pressure and vascular resistance increased after meconium instillation, but this rise was significantly prevented after prophylactic dexamethasone. This treatment also improved the acutely deteriorated oxygenation of the piglets after meconium insufflation. Prophylactic, but not early, dexamethasone treatment further protected the lungs from the ultrastructural changes caused by meconium instillation. Additionally, the increase of apoptotic epithelial cell deaths was significantly prevented by both dexamethasone treatments. These results show that prophylactic dexamethasone treatment significantly attenuates the early pulmonary hemodynamic deterioration and structural lung damage caused by meconium aspiration. Further studies on the apoptosis-inhibiting effect of dexamethasone administration in neonatal lungs exposed to heavy meconium are warranted.

Course of renal allograft histopathology after transplantation in early childhood

BACKGROUND

We report a long-term prospective follow-up of renal allograft histology in children <5 years of age at transplantation (Tx).

METHODS

Fifty-one kidney allograft recipients were prospectively followed for renal allograft histology and function up to 7 years after Tx. Twenty patients were recipients of kidneys from living related donors, and 31 were cadaveric kidney recipients. All patients received triple immunosuppression. Biopsies were analyzed according to the Banff classification and scored semiquantitatively. The "chronic allograft damage index" (CADI) was calculated.

RESULTS

Five of seven grafts were lost because of nephrosis in patients with congenital nephrotic syndrome of the Finnish type. Most of the biopsies (52-69%) were considered normal (Banff classification), and the proportion with chronic allograft nephropathy did not increase with time. The median CADI score was 2.5 (scale: 0-36) at 1.5 years and 3.5 at 7 years. Recipients with an acute rejection episode had higher CADI scores than recipients without acute rejection episode. Patients with a high CADI score at 3 years had inferior graft function at 5 years. Recipients <2 years of age had CADI scores and numbers of acute rejection episode similar to recipients between 2 and 5 years of age. However, in contrast to the older recipients, the younger recipients did not improve their absolute glomerular filtration rate with time.

CONCLUSIONS

The long-term histopathological findings were mostly mild and stable with time. Acute rejection episode had an impact on these changes and CADI predicted later graft function. Nonimmunological risk factors seem to be more important in the youngest recipients.

The protooncogene TCL1 is an Akt kinase coactivator

Human T cell prolymphocytic leukemia can result from chromosomal translocations involving 14q32.1 or Xq28 regions. The regions encode a family of protooncogenes (TCL1, MTCP1, and TCL1b) of unknown function. In yeast two-hybrid screening, we found that TCL1 interacts with Akt. All TCL1 isoforms bind to the Akt pleckstrin homology domain. Both in vitro and in vivo TCL1 increases Akt kinase activity and as a consequence enhances substrate phosphorylation. In vivo, TCL1 stabilizes the mitochondrial transmembrane potential and enhances cell proliferation and survival. In vivo, TCL1 forms trimers, which associate with Akt. TCL1 facilitates the oligomerization and activation of Akt. Our data show that TCL1 is a novel Akt kinase coactivator, which promotes Akt-induced cell survival and proliferation.