Danger signals in the initiation of the inflammatory response after myocardial infarction.

During myocardial infarction, sterile inflammation occurs. The danger model is a solid theoretic framework that explains this inflammation as danger associated molecular patterns activate the immune system. The innate immune system can sense danger signals through different pathogen recognition receptors (PRR) such as toll-like receptors, nod-like receptors and receptors for advanced glycation endproducts. Activation of a PRR results in the production of cytokines and the recruitment of leukocytes to the site of injury. Due to tissue damage and necrosis of cardiac cells, danger signals such as extracellular matrix (ECM) breakdown products, mitochondrial DNA, heat shock proteins and high mobility box 1 are released. Matricellular proteins are non-structural proteins expressed in the ECM and are upregulated upon injury. Some members of the matricellular protein family (like tenascin-C, osteopontin, CCN1 and the galectins) have been implicated in the inflammatory and reparative responses following myocardial infarction and may function as danger signals. In a clinical setting, danger signals can function as prognostic and/or diagnostic biomarkers and for drug targeting. In this review we will provide an overview of the established knowledge on the role of danger signals in myocardial infarction and we will discuss areas of interest for future research.

Retrospective study on the predictive factors in chronic trismus.

Trismus is one of the most debilitating and treatment-resistant complications resulting from head and neck oncological treatments. The objective of this study was to assess how primary tumour variables could assist in predicting chronic trismus. From a (retrospective) oncological database (Department of Oral and Maxillofacial Surgery, University Hospitals Leuven), tumour-related, surgical, and oral functional variables were reviewed. Contributing factors for chronic trismus, defined as a mouth opening of less than 35 mm, at least one year after treatment for oral squamous cell cancer, were assessed via logistic regression. A mediational analysis was conducted on the significant predictive variables. Thirteen out of 52 patients were observed to have chronic trismus. A significantly higher prevalence of trismus was found for increasing clinical T classification (p < 0.01), tumours based in the maxilla or the retromolar trigone (p = 0.04), after adjuvant radiotherapy (p = 0.04), and/or with masticatory muscle tumour invasion (p ≤ 0.02). Furthermore, radiotherapy significantly impacted T classification in chronic trismus, while T classification was significantly related to masticatory muscle invasion. Although radiotherapy and clinical T classification are well-established risk factors for postoperative trismus, masticatory muscle invasion should be considered as one of the main predictive factors.

Preoperative pain measurements in correlation to deep endometriosis classification with Enzian

Background: Deep Endometriosis (DE) classification studies with Enzian never compared solitary compartments (A, B, C, F), and combinations of anatomical locations (A&B, A&C, B&C, A&B&C), in correlation to pain. Therefore, the results of these studies are challenging to translate to the clinical situation. Objectives: We studied pain symptoms and their correlation with the solitary and combinations of anatomical locations of deep endometriosis lesion(s) classified by the Enzian score. Materials and Methods: A prospective multi-centre study was conducted with data from university and non-university hospitals. A total of 419 surgical DE cases were collected with the web-based application called EQUSUM (www.equsum.org). Main Outcome Measures: Preoperative reported numeric rating scale (NRS) were collected along with the Enzian classification. Baseline characteristics, pain scores, surgical procedure and extent of the disease were also collected. Results: In general, more extensive involvement of DE does not lead to an increase in the numerical rating scale for pain measures. However, dysuria and bladder involvement do show a clear correlation AUC 0.62 (SE 0.04, CI 0.54-0.71, p< 0.01). Regarding the predictive value of dyschezia, we found a weak, but significant correlation with ureteric involvement; AUC 0.60 (SE 0.04, CI 0.53-0.67, p< 0.01). Conclusions: Pain symptoms poorly correlate with anatomical locations of deep endometriosis in almost all pain scores, with the exception of bladder involvement and dysuria which did show a correlation. Also, dyschezia seems to have predictive value for DE ureteric involvement and therefore MRI or ultrasound imaging (ureter and kidney) could be recommended in the preoperative workup of these patients. What's new?: Dyschezia might have a predictive value in detecting ureteric involvement.

The diagnostic and therapeutic approach of a primary bilateral leiomyoma of the ovaries: a case report and a literature review.

INTRODUCTION: A primary fibroid (leiomyoma) arising from both ovaries is rare and can be difficult to diagnose as a result of the low incidence and its indistinctive presentation. A literature review on the diagnostic and therapeutic approach of this rare benign tumour is presented. We describe a case of bilateral primary ovarian fibroid with an unusual presentation to illustrate our recommendations for treatment. CASE PRESENTATION: A 37-year-old woman was admitted with symptoms of acute severe abdominal pain. She had a history of faint abdominal discomfort. Due to the acute deterioration of the abdominal pain a diagnostic laparoscopy was performed. A tumour arising from both ovaries was seen and a biopsy was taken in order to decide on further therapy. Histology showed a fibroid for which excision by a second laparoscopic intervention was planned. Due to excessive adhesions conversion to laparotomy was necessary. CONCLUSION: We recommend that in the case of an abnormal adnexal mass, particularly in women who want to preserve their fertility, frozen section histology be performed laparoscopically. A frozen section diagnostic procedure, instead of a regular biopsy, seems to be a useful tool during an elective diagnostic laparoscopic procedure in order to prevent potential morbidity as a result of possible future laparoscopy or even laparotomy. Previous laparoscopic procedures can cause massive adhesions that could impede a subsequent laparoscopic approach.

Automatic 3D dense phenotyping provides reliable and accurate shape quantification of the human mandible.

Automatic craniomaxillofacial (CMF) three dimensional (3D) dense phenotyping promises quantification of the complete CMF shape compared to the limiting use of sparse landmarks in classical phenotyping. This study assesses the accuracy and reliability of this new approach on the human mandible. Classic and automatic phenotyping techniques were applied on 30 unaltered and 20 operated human mandibles. Seven observers indicated 26 anatomical landmarks on each mandible three times. All mandibles were subjected to three rounds of automatic phenotyping using Meshmonk. The toolbox performed non-rigid surface registration of a template mandibular mesh consisting of 17,415 quasi landmarks on each target mandible and the quasi landmarks corresponding to the 26 anatomical locations of interest were identified. Repeated-measures reliability was assessed using root mean square (RMS) distances of repeated landmark indications to their centroid. Automatic phenotyping showed very low RMS distances confirming excellent repeated-measures reliability. The average Euclidean distance between manual and corresponding automatic landmarks was 1.40 mm for the unaltered and 1.76 mm for the operated sample. Centroid sizes from the automatic and manual shape configurations were highly similar with intraclass correlation coefficients (ICC) of > 0.99. Reproducibility coefficients for centroid size were < 2 mm, accounting for < 1% of the total variability of the centroid size of the mandibles in this sample. ICC's for the multivariate set of 325 interlandmark distances were all > 0.90 indicating again high similarity between shapes quantified by classic or automatic phenotyping. Combined, these findings established high accuracy and repeated-measures reliability of the automatic approach. 3D dense CMF phenotyping of the human mandible using the Meshmonk toolbox introduces a novel improvement in quantifying CMF shape.

Implementation of laparoscopic hysterectomy: maintenance of skills after a mentorship program.

BACKGROUND: To evaluate the implementation and maintenance of advanced laparoscopic skills after a structured mentorship program in laparoscopic hysterectomy (LH). METHODS: Cohort retrospective analysis of 104 successive LHs performed by two gynecologists during and after a mentorship program. LHs were compared for indication, patient characteristics and intraoperative characteristics. As a frame of reference, 94 LHs performed by the mentor were analyzed. RESULTS: With regard to indication, blood loss and adverse outcomes, both trainees performed LHs during their mentorship program comparable with the LHs performed by the mentor. The difference in mean operating time between trainees and mentor was not clinically significant. Both trainees progressed along a learning curve, while operating time remained statistically constant and comparable to that of the mentor. After completing the mentorship program, both gynecologists maintained their acquired skills as blood loss, adverse outcome rates and operating time were comparable with the results during their traineeship. CONCLUSION: A mentorship program is an effective and durable tool for implementing a new surgical procedure in a teaching hospital with respect to patient safety aspects, as indications, operating time and adverse outcome rates are comparable to those of the mentor in his own hospital during and after completing the mentorship program.

EQUSUM: Endometriosis QUality and grading instrument for SUrgical performance: proof of concept study for automatic digital registration and classification scoring for r-ASRM, EFI and Enzian.

STUDY QUESTION: Is electronic digital classification/staging of endometriosis by the EQUSUM application more accurate in calculating the scores/stages and is it easier to use compared to non-digital classification? SUMMARY ANSWER: We developed the first digital visual classification system in endometriosis (EQUSUM). This merges the three currently most frequently used separate endometriosis classification/scoring systems (i.e. revised American Society for Reproductive Medicine (rASRM), Enzian and Endometriosis Fertility Index (EFI)) to allow uniform and adequate classification and registration, which is easy to use. The EQUSUM showed significant improvement in correctly classifying/scoring endometriosis and is more user-friendly compared to non-digital classification. WHAT IS KNOWN ALREADY: Endometriosis classification is complex and until better classification systems are developed and validated, ideally all women with endometriosis undergoing surgery should have a correct rASRM score and stage, while women with deep endometriosis (DE) should have an Enzian classification and if there is a fertility wish, the EFI score should be calculated. STUDY DESIGN SIZE DURATION: A prospective endometriosis classification proof of concept study under experts in deep endometriosis was conducted. A comparison was made between currently used non-digital classification formats for endometriosis versus a newly developed digital classification application (EQUSUM). PARTICIPANTS/MATERIALS SETTING METHODS: A hypothetical operative endometriosis case was created and summarized in both non-digital and digital form. During European endometriosis expert meetings, 45 DE experts were randomly assigned to the classic group versus the digital group to provide a proper classification of this DE case. Each expert was asked to provide the rASRM score and stage, Enzian and EFI score. Twenty classic forms and 20 digital forms were analysed. Questions about the user-friendliness (system usability scale (SUS) and subjective mental effort questionnaire (SMEQ)) of both systems were collected. MAIN RESULTS AND THE ROLE OF CHANCE: The rASRM stage was scored completely correctly by 10% of the experts in the classic group compared to 75% in the EQUSUM group (P < 0. 01). The rASRM numerical score was calculated correctly by none of the experts in the classic group compared with 70% in the EQUSUM group (P < 0.01). The Enzian score was correct in 60% of the classic group compared to 90% in the EQUSUM group (P = 0.03). EFI scores were calculated correctly in 25% of the classic group versus 85% in the EQUSUM group (P < 0.01). Finally, the usability measured with the SUS was significantly better in the EQUSUM group compared to the classic group: 80.8 ± 11.4 and 61.3 ± 20.5 (P < 0.01). Also the mental effort measured with the SMEQ was significant lower in the EQUSUM group compared to the classic group: 52.1 ± 18.7 and 71.0 ± 29.1 (P = 0.04). Future research should further develop and confirm these initial findings by conducting similar studies with larger study groups, to limit the possible role of chance. LIMITATIONS REASONS FOR CAUTION: These first results are promising, however it is important to note that this is a preliminary result of experts in DE and needs further testing in daily practice with different types (complex and easy) of endometriosis cases and less experienced gynaecologists in endometriosis surgery. WIDER IMPLICATIONS OF THE FINDINGS: This is the first time that the rASRM, Enzian and EFI are combined in one web-based application to simplify correct and automatic endometriosis classification/scoring and surgical registration through infographics. Collection of standardized data with the EQUSUM could improve endometriosis reporting and increase the uniformity of scientific output. However, this requires a broad implementation. STUDY FUNDING/COMPETING INTERESTS: To launch the EQUSUM application, a one-time financial support was provided by Medtronic to cover the implementation cost. No competing interests were declared. TRIAL REGISTRATION NUMBER: N/A.

The mannose cap of mycobacterial lipoarabinomannan does not dominate the Mycobacterium-host interaction.

Pathogenic mycobacteria have the ability to persist in phagocytic cells and to suppress the immune system. The glycolipid lipoarabinomannan (LAM), in particular its mannose cap, has been shown to inhibit phagolysosome fusion and to induce immunosuppressive IL-10 production via interaction with the mannose receptor or DC-SIGN. Hence, the current paradigm is that the mannose cap of LAM is a crucial factor in mycobacterial virulence. However, the above studies were performed with purified LAM, never with live bacteria. Here we evaluate the biological properties of capless mutants of Mycobacterium marinum and M. bovis BCG, made by inactivating homologues of Rv1635c. We show that its gene product is an undecaprenyl phosphomannose-dependent mannosyltransferase. Compared with parent strain, capless M. marinum induced slightly less uptake by and slightly more phagolysosome fusion in infected macrophages but this did not lead to decreased survival of the bacteria in vitro, nor in vivo in zebra fish. Loss of caps in M. bovis BCG resulted in a sometimes decreased binding to human dendritic cells or DC-SIGN-transfected Raji cells, but no differences in IL-10 induction were observed. In mice, capless M. bovis BCG did not survive less well in lung, spleen or liver and induced a similar cytokine profile. Our data contradict the current paradigm and demonstrate that mannose-capped LAM does not dominate the Mycobacterium-host interaction.

The clinical relevance of hysteroscopic polypectomy in premenopausal women with abnormal uterine bleeding.

This study assessed the efficacy of hysteroscopic polyp removal in the management of abnormal uterine bleeding (AUB) of premenopausal patients. The monthly menstrual blood loss, measured semi-objectively by the pictorial blood loss assessment chart (PBAC) and patients satisfaction were recorded prospectively preoperatively and postoperatively. Twenty-one patients were included. Median monthly PBAC-score before treatment was 288 (range 142-670) and 6 months after polyp removal 155 (range 39-560). It was concluded that hysteroscopic polyp removal in premenopausal women with AUB reduces the monthly blood loss significantly and has a high satisfaction rate on the short term.

Effects of p21(Cip1/Waf1) at both the G1/S and the G2/M cell cycle transitions: pRb is a critical determinant in blocking DNA replication and in preventing endoreduplication.

It has been proposed that the functions of the cyclin-dependent kinase inhibitors p21(Cip1/Waf1) and p27Kip1 are limited to cell cycle control at the G1/S-phase transition and in the maintenance of cellular quiescence. To test the validity of this hypothesis, p21 was expressed in a diverse panel of cell lines, thus isolating the effects of p21 activity from the pleiotropic effects of upstream signaling pathways that normally induce p21 expression. The data show that at physiological levels of accumulation, p21, in addition to its role in negatively regulating the G1/S transition, contributes to regulation of the G2/M transition. Both G1- and G2-arrested cells were observed in all cell types, with different preponderances. Preponderant G1 arrest in response to p21 expression correlated with the presence of functional pRb. G2 arrest was more prominent in pRb-negative cells. The arrest distribution did not correlate with the p53 status, and proliferating-cell nuclear antigen (PCNA) binding activity of p21 did not appear to be involved, since p27, which lacks a PCNA binding domain, produced similar arrest distributions [corrected], DNA endoreduplication occurred in pRb-negative but not in pRb-positive cells, suggesting that functional pRb is necessary to prevent DNA replication in p21 G2-arrested cells. These results suggest that the primary target of the Cip/Kip family of inhibitors leading to efficient G1 arrest as well as to blockade of DNA replication from either G1 or G2 phase is the pRb regulatory system. Finally, the tendency of Rb-negative cells to undergo endoreduplication cycles when p21 is expressed may have negative implications in the therapy of Rb-negative cancers with genotoxic agents that activate the p53/p21 pathway.

Post passivation light trapping back contacts for silicon heterojunction solar cells.

Light trapping in crystalline silicon (c-Si) solar cells is an essential building block for high efficiency solar cells targeting low material consumption and low costs. In this study, we present the successful implementation of highly efficient light-trapping back contacts, subsequent to the passivation of Si heterojunction solar cells. The back contacts are realized by texturing an amorphous silicon layer with a refractive index close to the one of crystalline silicon at the back side of the silicon wafer. As a result, decoupling of optically active and electrically active layers is introduced. In the long run, the presented concept has the potential to improve light trapping in monolithic Si multijunction solar cells as well as solar cell configurations where texturing of the Si absorber surfaces usually results in a deterioration of the electrical properties. As part of this study, different light-trapping textures were applied to prototype silicon heterojunction solar cells. The best path length enhancement factors, at high passivation quality, were obtained with light-trapping textures based on randomly distributed craters. Comparing a planar reference solar cell with an absorber thickness of 280 µm and additional anti-reflection coating, the short-circuit current density (JSC) improves for a similar solar cell with light-trapping back contact. Due to the light trapping back contact, the JSC is enhanced around 1.8 mA cm-2 to 38.5 mA cm-2 due to light trapping in the wavelength range between 1000 nm and 1150 nm.

Local variations in protein structure in the human eye lens: a Raman microspectroscopic study.

Confocal Raman microspectroscopy was used to monitor local and age-related changes in protein conformation in human eye lenses. In clear human lenses of varying age (range 17-80 years) spectra were recorded along the visual axis, using laser light of 660 nm wavelength. The Raman vibrations in the 650-1750 cm-1 spectral region were analyzed. Difference spectra between central core and different positions along the visual axis were calculated after calibration for protein content using the I(1450) cm-1 CH2/CH3 vibration peak. Tryptophan content was quantified using the peak at 760 cm-1 calibrated for protein. Changes in the 'exposed' vs. 'buried' position of tryptophan were analyzed using the peak heights at I(880) and I(760) cm-1. The difference spectra revealed an excess of tryptophan, tyrosine, phenylalanine, beta-sheet conformation and molecules or molecular groups responsible for a 1425 cm-1 peak in the core region in all lenses investigated. The excess peaks disappeared at about 0.6-0.9 mm below the surface. The tryptophan content increased from superficial to deep layers, levelling off between 0.4-0.8 mm below the surface. Upon aging, the tryptophan content increases in the core not in the cortex. No changes in the 'exposed' vs. 'buried' position of tryptophan were observed. Changes in tryptophan and tyrosine probably reflect the maturational shift from cortex to core in the relative content of alpha, beta and gamma crystallines. The age-related increase in tryptophan in the core may reflect the preferential breakdown by endo- and exopeptidases of alpha-crystallins damaged upon aging. The increase in beta-sheet conformation may indicate a post-translational shift in secondary conformation upon aging. These changes in protein conformation are largely completed in a small superficial zone, i.e., in the early life span of the crystallins.

Cyclosporin increases cellular idarubicin and idarubicinol concentrations in relapsed or refractory AML mainly due to reduced systemic clearance.

The feasibility of adding both the multidrug resistance modulator cyclosporin (CsA) and granulocyte colony-stimulating factor (G-CSF) to a standard salvage regimen of idarubicin (IDA) and cytarabine was evaluated in patients with resistant or relapsed acute myeloid leukemia and myelodysplastic syndrome. Three patients received IDA 12 mg/m2/day, the next four patients 9 mg/m2/day. The dose of CsA was 16 mg/kg/day. Six patients showed Pgp expression and none MRP1 expression. Grade III or IV toxicity (CTC-NCIC criteria) was registered in six patients for gastrointestinal, two patients for cardiovascular and one patient for neurological complications. Three patients died in hypoplasia and three patients showed leukemic regrowth. Three control patients were treated with IDA 12 mg/m2/day and cytarabine, but no CsA and G-CSF. The plasma IDA and idarubicinol (ida-ol) area under the curve's of patients treated with IDA 12 mg/m2 plus CsA were higher (P< 0.05) than in controls. Cellular IDA concentrations were almost similar, but cellular ida-ol concentrations were significantly higher (P < 0.05) in the presence of CsA than in controls. We conclude that the toxicity either with IDA 12 or 9 mg/m2/day was too high. The modulating effect of CsA was mainly based on changes in plasma kinetics of IDA and ida-ol, although ida-ol cellular clearance was delayed in the presence of CsA.

Idarubicin DNA intercalation is reduced by MRP1 and not Pgp.

Currently available data regarding the substrate specificity of the multi-drug resistance (MDR) mechanisms P-glycoprotein (Pgp) and MDR-associated protein (MRP1) for idarubicin are inconclusive. A multiparameter flow cytometry method was developed which allows simultaneous quantitative measurement of total cellular fluorescence and the amount of anthracyclines intercalated into the DNA. Anthracycline DNA intercalation was measured by fluorescence resonance energy transfer (FRET) between Hoechst 33342 and anthracyclines. Daunorubicin and idarubicin accumulation were studied and compared in established cell lines expressing Pgp and MRP1. The data demonstrate that daunorubicin DNA intercalation is affected by both Pgp and MRP1 whereas idarubicin DNA intercalation is affected only by MRP1. MRP1 and Pgp function could be blocked completely by 5 microM PAK 104P, while higher concentrations of verapamil, PSC 833 and cyclosporin A were necessary to attain complete blocking of MRP1 compared to Pgp. Daunorubicin DNA intercalation correlates better with cell survival and is more sensitive at physiological MDR expression as observed in hematopoietic progenitors than daunorubicin levels measured by total cellular fluorescence. In conclusion, idarubicin DNA intercalation is reduced by MRP1 but not by Pgp. PAK-104P is an effective modulator for both Pgp and MRP1 and may further improve idarubicin efficacy.

The low cycling status of mobilized peripheral blood CD34+ cells is not restricted to the more primitive subfraction.

Mobilized peripheral blood progenitor cells (PBPC) have been shown to differ qualitatively from bone marrow (BM) progenitors. The released progenitor cells are predominantly in G0/G1 and show a relatively high percentage of rhodamine dull cells. Within the BM these last two features are characteristic of the more primitive progenitors. Although the mobilized PB cells can give rise to long-term repopulation and thus contain stem cells, the frequency of stem cells is not much higher if long-term initiating cell (LTC-IC) assays are used. To determine whether quiescent stem cells are selectively released or the low-cycle status of PB progenitors is related to the release from the BM microenvironment, the cell cycle status and rhodamine content in the PB and BM during mobilization were studied and compared with steady-state BM. More differentiated and more primitive progenitors were separated based on differentiation markers and cloned in single cell assay. In mobilized PB 54% of the CD34+ cells (n=5) were rhodamine dull compared to 22% in steady-state BM (P=0.014) [n=6]. The percentage of CD34+ cells in the S/G2M phases of the cell cycle was 2.1% in the mobilized PB (n=11), and 18% in steady-state BM (n=11) [P=0.002]. During mobilization the fraction of cells in the S/G2M phase of the cell cycle was 16% in BM (n=7), similar to steady-state BM (P=0.34). The released progenitors represented a selection of BM progenitors, with significantly more primitive progenitors (CD34+/13+/33dim) and less lymphoid precursors (CD34+/19+). Within the more differentiated CD34+113+/33bright, myelomonocytic precursors, both in PB as well as in BM, the percentage S/G2M was relatively higher than in the CD34+/13+/33dim subfraction: in normal BM: median 18% vs 8% (P=0.006) [n=8]; in mobilized PB 3% vs 2% (P=0.03) [n=10]; and in BM during mobilization 24% vs 7% (P=0.01) [n=6]. The cycle status of mobilized PB progenitors was low both in the primitive and more differentiated subfractions. During the mobilization period the BM progenitors are cycling as in steady-state BM. The low-cycle status of the mobilized PB progenitors may be related to the loss of contact with the micro-environment.

Tinea incognito due to Trichophytom rubrum after local steroid therapy.

The term "tinea incognito" refers to dermatophyte infections with clinical presentations that have been modified by the administration of corticosteroids. We describe a patient who had pustular inflammatory skin lesions due to Trichophyton rubrum after receiving treatment with potent topical corticosteroid creams.

Morphologic characteristics and chemical composition of Christmas tree cataract.

PURPOSE: Christmas tree cataract consists of highly refractile multicolored "needles" crisscrossing the lens fibers of the deep cortex. The fact that the colors vary according to the angle of the incident light, and that in retroillumination only a dim outline of the cataract is seen, would suggest that Christmas tree cataract is a diffractive phenomenon. This study was performed to unravel the ultrastructure and chemical composition of the Christmas tree needles. METHODS: Eight lenses from donor eyes and four extracapsularly extracted lenses with Christmas tree cataract were investigated by scanning and transmission electron microscopy. The chemical composition was studied with energy-dispersive x-ray microanalysis and Raman microspectroscopy. RESULTS: Scanning electron microscope examination showed that the needles are smooth, rectangular, plate-like elements bordered by membranes and amorphous material and running crisscross through the lens. In the specimens for transmission electron microscopic examination, the needles proved to be largely dissolved, but the remains showed regular spacings of approximately 5 nm. Material identical in spacing and electron density was found in neighboring cells bound to a reticular membranous network originating from the fiber-limiting membranes. Energy-dispersive x-ray and Raman microanalysis showed that the needles have a high sulfur content and pronounced S-S, CS-SC, and C-S vibrations. The cytoplasm adjacent to the needles and reticular meshwork had an elevated Ca++ content. CONCLUSIONS: It is concluded that cystine is the most likely candidate for the Christmas tree needles and that the needles probably are formed as the result of an age-related aberrant breakdown of crystallins induced by elevated Ca++ levels.

The effect of radiation on G2 blocks, cyclin B expression and cdc2 expression in human squamous carcinoma cell lines with different radiosensitivities.

The purpose of the present study was to investigate the role of cyclin B and cdc2 in the G2 delay and to test whether the magnitude of the G2 delay correlated with sensitivity to ionizing radiation in two human cell lines. Cell cycle delays were measured by flow cytometry after pulse labeling with bromodeoxyuridine, and expression of cell cycle control genes were measured in Western blots in radiosensitive SCC61 and radioresistant SQ20B cell lines. Flow cytometry data demonstrated that the duration of the G2 arrest was dose dependent in both cell lines, amounting to approximately 1.1 h/Gy. No difference was found between the cell lines in the length of the G2 block. Radiation exposure did not result in a decrease of cyclin B. Cyclin B protein levels in both asynchronous and synchronized populations in fact showed a dose dependent increase, concomitant with the rise in the fraction of cells in G2/M. Similarly, the cdc2 protein levels did not decrease after irradiation. However, it was found that the levels of hyperphosphorylated, and therefore inactive, kinase were significantly higher in irradiated cells than in unirradiated cells. The accumulation of this hyperphosphorylated form correlated with the arrest of cells in the G2 phase. Finally, immunocytochemical staining of cyclin B revealed an increase of this protein in the cytoplasm after irradiation and a decrease in nuclear staining. This differential localization could possibly account for the reduced nuclear phosphorylation of cdc2 kinase leading to the G2 arrest.

Differential repair of radiation-induced DNA damage in cells of human squamous cell carcinoma and the effect of caffeine and cysteamine on induction and repair of DNA double-strand breaks.

The goal of these experiments was to investigate further the relationship between DNA double-strand breaks and cell killing in human tumor cells, first by comparing different cell lines, and second by radiomodification studies. Field-inversion gel electrophoresis was used to quantify double-strand breaks. Two subclones of the radioresistant human squamous cell carcinoma line SQ20B (SQD9 and SQG6) were compared. These subclones differed in DNA index by a factor of 1.7 but showed the same resistance to radiation as cells of the parental cell line. It was found that, although induction of DSBs was not significantly different in the two cell lines, the t1/2 of the fast component of repair was significantly shorter for SQD9 cells, leading to greater overall repair which was not reflected in increased survival. Caffeine and cysteamine were tested as modifiers of radiosensitivity, using the radioresistant SQ20B line and the radiosensitive SCC61 cell line. No effect of caffeine was seen when the drug was present only during irradiation. Postirradiation incubations with caffeine, however, resulted in a dose reduction factor greater than 2.0 in cell survival for both cell lines. In contrast, induction of DSBs was reduced by caffeine, and no effect on DSB repair was observed. Cysteamine led to a dose protection factor greater than 1.8 in cell survival in both cell lines. A reduction in induced DSBs was found at high doses corresponding approximately with the increase in cell survival. Over the same (low) dose range, however, the correlation between DSB induction and cell killing was poor. These data indicate that DSB induction does not correlate well with cell killing either for different cell lines, for radiochemical modification (cysteamine) or for some other types of modification (caffeine).

Cosmetic result of lower midline laparotomy wounds: polybutester and nylon skin suture in a randomized clinical trial.

OBJECTIVE: To compare the cosmetic outcome of lower midline laparotomy scars using either nylon or polybutester suture for skin closure. METHODS: A randomized clinical trial compared polybutester skin suture with nylon for lower midline laparotomy wounds in 50 women undergoing gynecologic surgery. Scar hypertrophy, scar width, scar color, the presence of cross-hatching marks, and a total score were assessed in all patients at 18 months following surgery and compared by nonparametric statistical tests. RESULTS: The wounds closed with polybutester suture were significantly less hypertrophic than those closed with nylon. Regardless of the suture material used, the lower part of the laparotomy scar showed an inferior cosmetic result compared with the upper part underneath the umbilicus for scar hypertrophy, scar width, and the total scar score. CONCLUSIONS: Polybutester skin suture diminishes the risk of hypertrophic scarring because of its special properties allowing it to adapt to changing tensions in the wound. Increased closure tension of the skin in the midline region above the pubic bone may be caused by a relative immobility of the skin. Scar cosmetics in this area may be improved by extra subcuticular suture support.