bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparative study of aerodynamic function and flexural stiffness of outer tail feathers in birds
Authors: Tubaro Pablo L.
Published: August 2003

To transmit aerodynamic forces to the body, tail feathers should be stiff to resist lift forces with minimum deformation. Because aerodynamic theory predicts that such feathers do not produce lift forces beyond the point of the maximum continuum width of the tail, species with deeply forked tails should not require stiff outer rectrices distal to that point. I tested this prediction by comparing the relative thickness of the outer rectrix rachis between species with deeply forked tails to those with triangular or shallowly forked tails. Eleven pairs of closely related species belonging to families Fregatidae, Phalacrocoracidae, Accipitridae, Sternidae, Caprimulgidae, Trochilidae, Coraciidae, Tyrannidae, Cotingidae, and Hirundinidae were compared. All but one of the phylogenetically independent comparisons showed that the species with triangular or shallowly forked tails have higher relative rachis thickness than their deeply forked relatives. In addition, nine out of eleven of the species with deeply forked tails showed a proportionately greater increase in relative rachis thickness from distal to proximal parts of the feather. In contrast, triangular and shallowly forked tails showed an approximately linear relation between relative rachis thickness and relative rachis length. These results considered together are consistent with the idea that the distal part of outer rectrix rachis in species with deeply forked tails has not been selected to resist lift forces and may be adaptively reduced to attenuate the costs of a hypertrophied ornament.
Detection distance influences escape behaviour in two parids, Parus major and P. caeruleus
Authors: Lind Johan , Hollén Linda , Smedberg Erik , Svensson Ulrica , Vallin Adrian , Jakobsson Sven
Published: August 2003

When birds are attacked by aerial predators they should benefit by adjusting their escape to the prevailing attack situation. One important factor likely to affect escape decisions of prey, to our knowledge not previously studied, is the distance at which the attacking predator is detected. We investigated if great tits Parus major and blue tits P. caeruleus alter their escape behaviour to two different detection distances (2.3 m and 1m) by simulating surprise attacks using a predator model. Both species used the information about detection distance when escaping by increasing the escape angle at the shorter detection distance. In addition, blue tits adjusted to the shorter detection distance by dodging sideways more frequently. Great tits escaped initially steeper and faster than blue tits, whereas blue tits increased escape angle and speed more than great tits along the measured distance after taking wing.
Acoustic properties of male advertisement and their impact on female responsiveness in little penguins Eudyptula minor
Authors: Miyazaki Masamine , Waas Joseph R.
Published: August 2003

We examined the relationship between acoustic properties of male advertising calls, male body size and female responses in little penguins Eudyptula minor. Larger males produced calls of lower frequency. Playback experiments indicated that females were more likely to respond to low or medium pitched calls, than to high ones (although only 28% of females responded vocally to playback). This may reflect the interest of unmated females in large to medium sized senders as potential mates, or indicate a stronger territorial response to large intruders.
Reproductive tactics of the ringed plover Charadrius hiaticula
Authors: Wallander Johan , Andersson Malte
Published: August 2003

Reproductive tactics of ringed plovers Charadrius hiaticula were studied at three localities in SW Sweden during five seasons. The usual clutch size is four, but removal experiments showed that females can produce five eggs in succession, with similar intervals between all eggs. High predation made mean breeding success per clutch low, 6.3% of eggs resulting in fledged young. Replacement clutches were common, and many pairs laid again after rearing their first brood to fledging. Egg laying spanned three months, much longer than for other waders in this region. Between years, reproductive success varied unpredictably with time of the season, but averaged over several years, the expected success was low and similar for the different parts of the breeding season. Chicks from late clutches had similar survival and recruitment as others. Because of the long breeding season and high rate of nest failure a female may produce up to five clutches of four eggs per season, containing in total about 3.7 times her own mass. Yearly local survival of adult females and males was estimated to 84.6 and 88.6%, respectively. Ability to produce many clutches with similar expected success throughout the season favours a long reproductive period, sometimes leading to double‐brooding. Possible life‐history trade‐offs are discussed.
Structural plumage colour and parasites in satin bowerbirdsPtilonorhynchus violaceus: implications for sexual selection
Authors: Doucet Stéphanie M. , Montgomerie Robert
Published: August 2003

We investigated whether variation in structural plumage coloration in satin bowerbirds,Ptilonorhynchus violaceus, could reveal the intensity of infection from parasites, as predicted from models of parasite‐mediated sexual selection (PMSS). To do this, we captured adult male, female, and juvenile male satin bowerbirds in Queensland, Australia, and objectively measured individual plumage reflectance from four body regions using a spectrometer. We quantified both ectoparasite load and the intensity of infection from blood parasites. In iridescent blue adult males, plumage reflectance is unimodal, with a single peak in the ultraviolet, while in greenish females and juveniles, plumage reflectance is bimodal, with peaks in both the ultraviolet and green portions of the spectrum. In adult males, the intensity of infection from blood parasites was best predicted by plumage brightness (total reflectance), with brighter males having fewer parasites. Similarly, juvenile males exhibiting greater UV chroma (proportion of reflectance in the UV) had fewer blood parasites. Our findings support a key prediction of PMSS models and provide the first evidence that a structural colour ornament can signal the intensity of infection from blood parasites.
Retinoblastoma gene expression in human non‐melanoma skin cancer
Authors: Edwards Malcolm J. , Thomas R. C. , Wong Y. L.
Published: August 2003

Background:  The aberrant expression of both the retinoblastoma and p53 tumor suppressor genes has been associated with more aggressive tumors, metastasis and lower survival.

Methods:  We have evaluated immunohistochemically the expression of pRB in a panel of non‐melanoma skin cancers containing p53 somatic mutations.

Results:  Nuclear anti‐p53 staining was detected in 18 (72%) differentiated squamous cell carcinomas, six (100%) undifferentiated squamous cell carcinomas and seven (28%) basal cell carcinomas. A correlation was observed between p53 expression and the proliferative activity of differentiated squamous cell carcinomas (P < 0.066), undifferentiated squamous cell carcinomas (P < 0.05) and basal cell carcinomas (P < 0.01). Tumors were selected for mutant p53 expression by PCR‐directed DNA sequencing and pRB expression measured immunohistochemically. Anti‐pRB reactivity was detected in the nuclei of basal and suprabasal layer cells of normal epidermis, and in the proliferative compartment of all the differentiated squamous cell carcinomas, and basal cell carcinomas. A correlation was observed between pRB expression and the proliferative activity of the differentiated squamous cell carcinomas (P < 0.01) and basal cell carcinomas (P < 0.025). However, anti‐pRB reactivity was not detected in the six anti‐p53 reactive undifferentiated squamous cell carcinomas.
Proliferating trichilemmal tumors: clinicopathologic evaluation is a guide to biologic behavior
Authors: Folpe Andrew L. , Reisenauer Amy K. , Mentzel Thomas , Rütten Arno , Solomon Alvin R.
Published: August 2003

Background:  Trichilemmal (pilar) cysts are common skin lesions that usually occur on the scalp of elderly women. They differentiate towards the follicular outer root sheath epithelium and show trichilemmal keratinization. Proliferating trichilemmal tumor (PTT) shows features of typical pilar cyst, but additionally shows extensive epithelial proliferation, variable cytologic atypia and mitotic activity. The malignant potential of PTT is controversial, as only a small number of histologically malignant PTTs and a smaller number of clinically malignant PTTs have been reported.

Methods:  We retrieved from our archives five PTTs that deviated from ordinary PTTs with regards to either cytology or architecture. We also reviewed all previous reports of histologically malignant PTTs, with the goal of delineating criteria for the diagnosis of malignant PTTs.

Results:  Five cases of PTT showing atypical cytoarchitectural features were retrieved from our archives and reviewed with respect to size, growth pattern, cellularity, cytologic atypia, and mitotic activity. The patients (four female, one male) ranged from 54 to 83 (mean 65) years. The tumors measured from 1 to 16 cm in diameter (mean 5 cm) and four out of five occurred on the scalp. All tumors showed at least focal areas of typical PTTs. Three cases were circumscribed but had areas of moderate to focally marked cytologic atypia. Two cases showed infiltrative growth, marked cytologic atypia and mitotic activity. Clinical follow‐up was available for four of five cases and ranged from 6 to 84 (median 48) months. Follow‐up showed two cases with local recurrence and one case with distant metastasis. This last patient died of disease; all other patients are disease‐free.

Conclusions:  Review of our cases and the published literature suggests that the diagnosis of malignant PTT be given to PTT showing a combination of non‐scalp location, recent rapid growth, size greater than 5 cm, infiltrative growth, and significant cytologic atypia with mitotic activity. At the present time the stratification of malignant PTT into low‐ and high‐grade categories is not possible.
Cutaneous metastasis of neuroendocrine carcinoma of the larynx: report of a case
Authors: Ottinetti A. , Colombo E. , Dardano F. , Migliora P. , Picciotto F. , Zaccagna A. , Angeli G.
Published: August 2003

Background:  Cutaneous metastasis from neuroendocrine carcinomas of visceral origin is rarely described in indexed literature. The primary sites of origin include: lung (Wick et al., J Am Acad Dermatol 1985; 13: 134), larynx (Zambruno et al., Ann Dermatol Venereol 1989; 116: 855; Schmidt et al., J Laryngol Otol 1994; 108: 272; Guerzider et al., Ann Pathol 1991; 11 (4): 253), mediastinum (Yoshimasu et al., J Dermatol 2001; 28 (3): 168), uterus (Fogaca et al., J Cutan Pathol 1993; 20: 455), and thymus (Wick et al., J Am Acad Dermatol 1985; 13: 134).

Methods:  In this report, the authors present the clinical, histological, immunohistochemical, and ultrastructural characteristics of secondary skin localizations of a neuroendocrine laryngeal tumor that occurred in a 61‐year‐old man. The complete follow up of the case is described and a brief revision of the terminology and classification of neuroendocrine neoplasms of the larynx is discussed, since a significant relationship exists between the degree of differentiation and biological behavior.

Results:  On histological examination, the secondary cutaneous localization appeared to be more dedifferentiated compared to the primary tumor. The immunohistochemical patterns of reactivity were similar in both neoplasms, showing expression of neuroendocrine and epithelial markers.

Conclusions:  An important issue of prognostic significance is to differentiate a cutaneous metastasis of a neuroendocrine carcinoma from the primary small cell‐undifferentiated carcinoma of the skin (Merkel cell carcinoma).
Primary purely intradermal pleomorphic liposarcoma
Authors: Val‐Bernal J. Fernando , González‐Vela M. Carmen , Cuevas Jorge
Published: August 2003

Introduction:  Pleomorphic liposarcoma (PLPS) is a high‐grade pleomorphic sarcoma, containing multivacuolated lipoblasts, which usually develops during late adult life. It usually occurs in the deep soft tissues and uncommonly arises in the subcutis, the dermis representing an exceedingly rare site of occurrence.

Methods:  We describe a case of PLPS arising in the dorsal aspect of the nose of a 75‐year‐old woman. Preoperative duration was 9 months.

Results:  The lesion was intradermal well‐circumscribed, dome‐shaped, measuring 1.2 cm. It fulfilled the histologic criteria for inclusion in the PLPS category. The tumor cells focally expressed calretinin. A review of the literature yielded four cases documented, to which we add the present report. All the patients were adults with a mean age of 67 (range 39–95) years, and three of five cases arose on the scalp. Local recurrence occurred in one patient, but no distant metastases or disease‐related deaths were observed.

Conclusion:  PLPS very rarely arises in the dermis. In spite of high‐grade morphology, the intradermal tumor shows a relatively favorable prognosis. Diagnostic consideration includes pleomorphic lipoma, clear cell atypical fibroxanthoma, balloon cell melanoma, and metastatic clear cell carcinoma of renal origin. Recognition of this distinctive and rare type of liposarcoma is essential to avoid under‐ or misdiagnosis and inappropriate treatment.
Improved detection of clonality in cutaneous T‐cell lymphomas using laser capture microdissection
Authors: Yazdi Amir S. , Medeiros L. Jeffrey , Puchta Ursula , Thaller Eva , Flaig Michael J. , Sander Christian A.
Published: August 2003

Background:  The diagnosis of cutaneous T‐cell lymphoma is a challenge for both the pathologist and the clinician. This is particularly true for distinguishing early‐stage mycosis fungoides from dermatitis. In this clinical setting, the presence of a clonal T‐cell population supports lymphoma.

Methods:  Usually, routinely processed paraffin‐embedded material is available for gene rearrangement analysis, and polymerase chain reaction (PCR)‐based methods to assess clonality can be performed. One drawback of this approach is that sensitivity is suboptimal in biopsy specimens in which the lymphocytic infiltrate represents only a small percentage of all cells present. Another drawback is that DNA extraction from routinely processed, paraffin‐embedded tissue is a time‐consuming and labor‐intensive procedure which can take up to 5 days in our laboratory. To bypass these problems, we used laser capture microdissection (LCM) to obtain lymphocytic infiltrates from tissue sections of formalin‐fixed, paraffin‐embedded skin biopsy specimens. This approach allows for more specific PCR assessment of the lymphocytic infiltrate and for rapid DNA extraction and PCR analysis.

Results:  Using the LCM approach, we could demonstrate clonal T‐cell receptor γ gene rearrangements in biopsy specimens that did not show clonality using DNA extracted by conventional methods from full tissue sections. In addition, DNA extraction and PCR analysis can be performed in 11 h.

Conclusion:  In conclusion, applying LCM to clonality analysis of cutaneous lymphocytic infiltrates is rapid and more sensitive than conventional methods, and we recommend introducing this approach into the routine diagnostic setting.
Epidermal basaloid proliferation in cutaneous myxomas
Authors: Mehregan Darius R. , Thomas Laura , Thomas Jean E.
Published: August 2003

Background:  Basaloid epidermal proliferations, which histologically resemble basal cell carcinoma, have been described overlying dermatofibromas. Several etiologies have been proposed. Cutaneous myxomas are also benign mesynchymal tumors.

Purpose:  Basaloid proliferations have been noted overlying cutaneous myxomas. We have undertaken a study to attempt to differentiate whether these are basal cell carcinomas or benign basaloid proliferations.

Methods:  Thirty cases of cutaneous myxomas were included in this study. The lesions were stained with hematoxylin–eosin and alcian blue. Immunohistochemical staining for both epidermal growth factor receptor (EGF‐r) and p53 protein was performed on the cutaneous myxomas with epidermal basaloid proliferation.

Results:  Of the 30 cases of cutaneous myxomas, nine were found to have an associated overlying basaloid proliferation. The basaloid proliferations were limited to the epidermis overlying the myxoid changes within the dermis. Mitotic figures were rare. Staining for p53 protein showed scattered positive staining in the basal cells in both the basaloid proliferations and adjacent epidermis. EGF‐r showed positive staining of the overlying epidermis and basaloid proliferation in five cases.

Conclusions:  We report basaloid proliferations overlying cutaneous myxomas and propose that these represent benign adnexal proliferations rather than superficial basal cell carcinoma and are analogous to the basaloid proliferations overlying dermatofibromas.
Automated kappa and lambda light chain mRNA expression for the assessment of B‐cell clonality in cutaneous B‐cell infiltrates: its utility and diagnostic application
Authors: Magro Cynthia , Crowson A. Neil , Porcu Pierluigi , Nuovo Gerard J.
Published: August 2003

Introduction:  Primary cutaneous B‐cell lymphoma (1°CBCL) accounts for 25% of all lymphomas. The difficulty in distinction of reactive from neoplastic B‐cell infiltrates prompts the use of molecular diagnostic adjuncts. While T‐cell clonality can be seen in various reactive states, clonal B‐cell infiltrates are often neoplastic; standard assays employed include polymerase chain reaction (PCR) or Southern blot analysis to assess heavy chain rearrangement. We sought to assess the utility of kappa (κ) and lambda (λ) mRNA expression using the Ventana automated assay (Ventana Medical Systems, Tucson, AZ, USA) in the analysis of atypical cutaneous B‐cell lymphoid infiltrates.

Materials and methods:  Multiple 4 µm sections of paraffin‐embedded, formalin‐fixed skin biopsies from 31 patients with CBCL were placed on silane‐coated slides, deparaffinized, then digested in pepsin (5 mg/ml) for 30 min at 37°C. Fluorescein‐tagged oligoprobes and tissue mRNA were denatured at 80°C for 5 min, hybridized for 2 h at 37°C, and incubated with antifluorescein alkaline phosphatase conjugates. Detection of the probe target complex employed nitroblue tetrazolium and bromochloroindolyl phosphate conjugates with a nuclear fast red counterstain. A κ : λ ratio > 3 : 1 was held to represent κ light chain restriction and a κ : λ ratio ≤ 1 : 1 to indicate λ light chain restriction.

Results:  The diagnosis in each case was determined by careful integration of clinical, histologic, and phenotypic data. The diagnoses included: pseudolymphoma (PL), marginal zone lymphoma (MZL), 1°CBCL of the trunk, scalp or leg, 2° lymphoma, and plasma cell dyscrasia. All but one case of lymphoma were light chain restricted. All cases of PL were proven to be polyclonal by this methodology. In non‐plasmacytic small cell lymphomas, only 5–10% of the infiltrate expressed κ or λ, with clonality established through the abnormal κ : λ ratio. Interpretations were most difficult in the 2° small cell‐dominant follicular center cell lymphomas and easiest in cases with significant plasmacytic differentiation (i.e. MZL, immunocytomas, or plasma cell dyscrasias).

Conclusion:  The Ventana κ/λ assay is a reliable, quick, and inexpensive way to determine B‐cell clonality in cutaneous lymphoid infiltrates in paraffin‐embedded formalin‐fixed tissue.
Assessment of the skin photoprotective capacities of an organo‐mineral broad‐spectrum sunblock on two ex vivo skin models
Authors: Gélis Christelle , Girard Stéphanie , Mavon Alain , Delverdier Maxence , Paillous Nicole , Vicendo Patricia
Published: August 2003

UV irradiation can cause cutaneous damage that may be specific according to the wavelength of UV rays. For example, damage from UVB irradiation manifests itself in the form of sunburn cells and enhancement of the expression of p53, while damage from UVA exposure results in an increase in the expression of vimentin. These reactions to UV irradiation were used in this work to evaluate the photoprotective capacities of two sunblock preparations that were applied to the surface of the skin. One sunblock preparation is a UVB absorber containing zinc oxide (ZnO) and titanium oxide (TiO2) exclusively. The other sunblock preparation is a new organo‐mineral sunblock containing Tinosorb™ M, OCM, ZnO and TiO2. Evaluation of the photoprotective capacities of both preparations on hairless rat skin and on in vitro reconstructed human epidermis revealed that they were effective in preventing UVB‐induced damage. In contrast, only the organo‐mineral sunblock was effective in the prevention of UVA‐specific damage such as dermal alterations characterized by the expression of vimentin. Furthermore, our data support the fact that hairless rat skin and in vitro reconstructed human epidermis are a reliable basis for the evaluation of the photoprotective capacities of various sunscreens against UVB and UVA damage.
Assessment of the usefulness of skin phototype and skin color as the parameter of cutaneous narrow band UVB sensitivity in psoriasis patients
Authors: Youn Jai Il , Park Je Young , Jo Seong Jin , Rim Jong Hyun , Choe Yong Beom
Published: August 2003

Background: Many reports have been released to assess skin types, skin colors and cutaneous sensitivity to broad band UVB or UVA.

Objective: This study was performed to investigate the usefulness of skin type and skin color as the parameter of narrow band UVB (NBUVB) sensitivity.

Methods: The minimal erythema dose (MED) of 40 psoriasis patients was investigated by irradiating several doses ranging from 200 to 1500 mJ/cm2. Before phototesting, the skin color of buttock was measured with a tristimulus colorimeter.

Results: The median and mode value of MED of NBUVB was 950 mJ/cm2. Skin type was well correlated with the MED and there was a significant relationship between the L* value and MED, but not for the a* and b* values.

Conclusion: The MED value of NBUVB in our study is a basic data to set the phototherapy protocol. Our result showed that skin type and L* value might be useful for predicting the sensitivity to NBUVB irradiation.
Simplified method to substantiate SPF labeling for sunscreen products
Authors: Sayre Robert M. , Stanfield Joseph , Lott Dennis L. , Dowdy John C.
Published: August 2003

Background/Purpose: Worldwide, sunscreen sun protection factor (SPF) testing is based on 30‐year‐old technology. At the time the SPF test came into being, the highest SPFs available were in the 6–8 range. The SPF test is reasonably accurate for SPFs up to 15, but is much less reliable for measuring SPFs of 30 and higher. The method we propose addresses two primary reasons for this unreliability: 1) difficulties in applying products uniformly and 2) the subjectivity and variability of perception in evaluating and grading responses to UV doses.

Methods: Our proposed SPF substantiation method differs from the current SPF test in that sunscreen‐protected test sites receive the same UV dose in four uniformly spaced sub‐sites, which are graded as passing if no response is seen or failing if any response is seen. The response may be tanning, erythema, or a combination of both. To demonstrate the method, two commercial products with labeled SPFs of 30 and 45 and the P2 sunscreen standard were tested at two different laboratories.

Results: The SPF 30 product and SPF 15 standard were shown to be correctly labeled. However, it is questionable as to whether the SPF 45 product provides protection against 45 minimal erythema doses.

Conclusions: Our proposed SPF substantiation method is not dependent on subjective evaluation of responses, accounts for non‐uniform product application, and provides a conservative estimate of sunscreen protection. The method consists of a systematic repetition of identical tests that are considerably more rigorous than the current methods that are based on single data points per test subject. While the current SPF test remains necessary and valuable as a dose ranging tool, we propose that this SPF substantiation method supersede the old method for final SPF label determination.
Narrowband UVB therapy in the treatment of lichen planus
Authors: Saricaoğlu Hayriye , Karadogan Serap Köran , Başkan Emel Bülbül , Tunali Şükran
Published: August 2003

Background: Recently, UVB lamps with a peak emission around 311 nm have been used successfully for the treatment of many dermatologic diseases known to be treated with psoralen plus UVA (PUVA). Narrowband UVB (NBUVB) radiation causes less erythema and carcinogenicity with lower cumulative doses than PUVA, while the treatment response remains high. Lichen planus (LP) is a cell‐mediated immune response of unknown origin.

Methods: We present our results of NBUVB therapy administered to 10 LP patients. The sessions were administered three to four times weekly with an average cumulative dose of 17.7±1.6 J/cm2.

Results: Five patients responded completely, and four were partially responsive at the end of the 30th session. Three of the partially responsive cases responded completely at the 31st, 36th and 51st sessions, respectively.

Conclusion: Clinical improvements observed in our study as well as the potential advantages of NBUVB imply that it is an inevitable treatment alternative for resistant cases of LP.
Cutaneous effects of infrared radiation: from clinical observations to molecular response mechanisms
Authors: Schieke Stefan M. , Schroeder Peter , Krutmann Jean
Published: August 2003

Human skin is exposed to infrared (IR) radiation (760 nm–1 mm) from natural as well as artificial sources that are increasingly used for cosmetic or medical purposes. Epidemiological data and clinical observations, however, indicate that IR radiation cannot be considered as totally innocuous to human skin. In particular, IR radiation, similar to ultraviolet radiation, seems to be involved in photoaging and potentially also in photocarcinogenesis. The molecular consequences resulting from IR exposure are virtually unknown. Recent studies, however, have begun to shed light on the basic molecular processes such as cellular signal transduction and gene expression triggered by exposure to IR radiation. In response to IR irradiation, mitogen‐activated protein kinase signaling pathways were activated mediating the upregulation of matrix metalloproteinase‐1 expression. This previously unrecognized molecular ‘IR response’ shows that IR radiation is capable of specifically interfering with cellular functions and provides a molecular basis for biological effects of IR on human skin.
Review article: mechanisms of action of mesalazine in preventing colorectal carcinoma in inflammatory bowel disease
Authors: Allgayer H.
Published: August 2003

A series of epidemiological, experimental and preliminary clinical trials strongly suggest that mesalazine or 5‐aminosalicyclic acid (5‐ASA) may have antineoplastic and potentially prophylactic chemopreventive properties. It is assumed that mesalazine may have similar genetic and molecular targets as nonsteroidal anti‐inflammatory drugs (NSAIDs), which is further supported by its close similarity with aspirin, differing only in its structure by the presence of an amino group at position 5 of the benzene ring. The putative chemopreventive actions include the inhibition of inflammatory cascades and/or reactions involved in cell growth and proliferation, such as cyclo‐oxygenase (COX‐1 and COX‐2), which regulate cell proliferation through the formation of prostaglandins; lipoxygenase; nuclear factor κB (NFκB), responsible for the subsequent expression of pro‐inflammatory molecules; MAP kinases and Bcl‐2, as well as the activation of apoptotic processes, such as the stimulation of intestinal sphingomyelinase. The peroxisome‐proliferator‐activated receptor δ (PPARδ), which also regulates gene transcription, is thought to play a role in both inflammatory and non‐inflammatory driven carcinogenesis. This may be another significant target. It is hypothesized that 5‐ASAs may prevent the enhancing effect of prostaglandins on PPARδ binding to DNA by its COX inhibitory properties, decreasing proliferation of colorectal mucosal cells in non‐inflammatory bowel disease patients with sporadic polyps of the large bowel.
Review article: the incidence and prevalence of colorectal cancer in inflammatory bowel disease
Authors: Munkholm P.
Published: August 2003

Although colorectal cancer (CRC), complicating ulcerative colitis and Crohn's disease, only accounts for 1–2% of all cases of CRC in the general population, it is considered a serious complication of the disease and accounts for approximately 15% of all deaths in inflammatory bowel disease (IBD) patients.

The magnitude of the risk was found to differ, even in population‐based studies. Recent figures suggest that the risk of colon cancer for people with IBD increases by 0.5–1.0% yearly, 8–10 years after diagnosis. The magnitude of CRC risk increases with early age at IBD diagnosis, longer duration of symptoms, and extent of the disease, with pancolitis having a more severe inflammation burden and risk of the dysplasia‐carcinoma cascade.

Considering the chronic nature of the disease, it is remarkable that there is such a low incidence of CRC in some of the population‐based studies, and possible explanations have to be investigated. One possible cancer‐protective factor could be treatment with 5‐aminosalicylic acid preparations (5‐ASAs).

Adenocarcinoma of the small bowel is extremely rare, compared with adenocarcinoma of the large bowel. Although only few small bowel cancers have been reported in Crohn's disease, the number was significantly increased in relation to the expected number.
Review article: colitis‐associated cancer – time for new strategies
Authors: Shanahan F.
Published: August 2003

Colorectal cancer (CRC) remains a feared and potentially life‐threatening complication of both ulcerative colitis and Crohn's colitis. Currently, the main preventive strategy is a secondary one, i.e. surveillance colonoscopy usually after 8 years of disease duration, when the risk for neoplasia begins to increase. Despite its widespread acceptance, dysplasia and cancer surveillance is unproven in terms of reducing mortality or morbidity and there is a remarkable lack of uniformity in the manner in which it is practised.

In this review article, the pitfalls of dysplasia surveillance are summarized and the need for novel chemopreventive and perhaps pharmabiotic approaches for prevention are highlighted.
An in vitro model of epithelial cell growth stimulation in the rodent mammary gland
Authors: Ehmann U. K. , DeVries J. T. , Chen M. S. C. , Adamos A. A. , Guzman R. C. , Omary M. B.
Published: August 2003

Abstract. Mouse mammary epithelial cell cultures previously described bring about extensive proliferation and a cell population with the appropriate markers for luminal ductal epithelial cells, and also the ability to form normal tissue after implantation into mice. This success may result from a culture environment that resembles certain aspects of the environment in the mammary gland. Mouse mammary epithelial cells, whose proliferation is limited when plated alone, can be stimulated to multiply by contact with lethally irradiated cells of the LA7 rat mammary tumour line. Most of the proliferative stimulus is imparted by direct cell contact between LA7 and mouse mammary cells. Junctions, including adherens junctions, form among all cells in the culture, much as junctions form in the mammary gland. LA7 cells secrete TGFα and bFGF, factors found in the mammary gland, and factors to which mouse mammary cells respond in culture. Mouse mammary cells express keratins 8 and 18, markers for luminal cells of the mammary duct. LA7 cells express keratin 14 and vimentin, markers for myoepithelial cells. These facts, taken together, fit a model of cell replacement in an epithelial tissue and also imitate the relationship between luminal ductal cells and myoepithelial cells in the mammary gland. This method of culturing cells is useful, not only for in vitro–in vivo carcinogenesis studies, but also for the study of mechanisms by which growth signals are imparted from one cell to another.
An efficient method for the rapid establishment of Epstein‐Barr virus immortalization of human B lymphocytes
Authors: Oh H.‐M. , Oh J.‐M. , Choi S.‐C. , Kim S.‐W. , Han W.‐C. , Kim T.‐H. , Park D.‐S. , Jun C.‐D
Published: August 2003

Abstract. Several methods have been developed for the immortalization of B lymphocytes by Epstein‐Barr virus (EBV). We developed an efficient method which reduces the time from culture initiation to immortalization and cryopreservation. Two infections of EBV to lymphocytes, and the use of phorbol ester‐induced EBV stock significantly improved immortalization efficiency and reduced the time between initiation and immortalization and cryopreservation. The resulting cell bank was used to produce DNA for genetic studies focusing on the genes involved in immune and autistic disorders.
Intestinal crypt clonogens: a new interpretation of radiation survival curve shape and clonogenic cell number
Authors: Roberts S. A. , Hendry J. H. , Potten C. S.
Published: August 2003

Abstract.  Estimates of the clonogen content (number of microcolony‐forming cells) of murine intestinal crypts using microcolony assays show an apparent dependence on the radiation dose used in the assay of clonogen content. Crypt radiation survival curves often show increased curvature beyond that expected on the basis of the conventional linear‐quadratic model. A novel form of crypt survival curve shape is proposed based on two contributory mechanisms of crypt killing. Six previously published sets of microcolony data were re‐analysed using a dual‐kill model, where target cells are killed by two contributory mechanisms, each described by a linear‐quadratic function of dose. The data were analysed as two series – high‐dose rate and low‐dose rate irradiation. The data were fitted to the models using direct maximization of a quasi‐likelihood, explicitly allowing for overdispersion. The dual‐kill model can reproduce both the apparent dose‐dependence of the clonogen estimates and the high‐dose curvature of the dose–response curves. For both series of data the model was a significantly better fit to the data than the standard linear‐quadratic model, with no evidence of any systematic lack of fit. The parameters of the clonogenic cell component of the model are consistent with other studies that suggest a low clonogen number (somewhat less than five) per crypt. The model implies that there is a secondary mechanism decreasing clonogen survival, and hence increasing clonogen number estimates, at high doses. The mechanisms underlying the modification of the dose–response are unclear, and the implied mechanisms of, for example, slow growth, induced either directly in the surviving cells or indirectly through stromal injury or bystander effects are only speculative. Nevertheless, the model fits the data well, demonstrating that there is greater kill at high doses in these experimental series than would be expected from the conventional linear‐quadratic model. This alternative model, or another model with similar behaviour, needs to be considered when analysing in detail and interpreting microcolony data as a function of dose. The implied low number of ≤ 5 of these regenerative and relatively radioresistant clonogenic cells is distinct from a similar number of much more radiosensitive precursor stem cells which undergo early apoptosis after doses around 1 Gy.
Iron deprivation induces apoptosis independently of p53 in human and murine tumour cells
Authors: Truksa J. , Kovář J. , Valenta T. , Ehrlichová M. , Polák J. , Naumann P. W.
Published: August 2003

Abstract.  Iron deprivation induces apoptosis in some sensitive cultured tumour cells, while other cells are resistant. In order to elucidate the mechanisms involved in apoptosis induction by iron deprivation, we studied the expression of p53 and the expression of selected p53‐regulated genes. To discriminate between changes coupled only with iron deprivation and changes involved in apoptosis induction by iron deprivation, we compared the expression of the genes in sensitive (human Raji, mouse 38C13) versus resistant (human HeLa, mouse EL4) cells under iron deprivation. Iron deprivation was achieved by incubation in a defined iron‐free medium. The level of p53 mRNA decreased significantly under iron deprivation in sensitive cells, but it did not change in resistant cells. On the contrary, the level of the p53 protein under iron deprivation was slightly increased in sensitive cells while it was not changed in resistant cells. The activity of p53 was assessed by the expression of selected p53‐regulated targets, i.e. p21WAF1/CIP1 gene, mdm2, bcl‐2 and bax. We did not detect any relevant change in mRNA levels as well as in protein levels of these genes under iron deprivation with the exception of p21WAF1/CIP1. We detected a significant increase in the level of p21 mRNA in both (sensitive and resistant) mouse cell lines tested, however, we did not find any change in both (sensitive and resistant) human cell lines. Moreover, the p21WAF1/CIP1 protein was accumulated in mouse‐sensitive 38C13 cells under iron deprivation while all other cell lines tested, including human‐sensitive cell line Raji, did not show any accumulation of p21WAF1/CIP1 protein. It seems that the p21WAF1/CIP1 mRNA, as well as protein accumulation, is not specifically coupled with apoptosis induction by iron deprivation and that it is rather cell‐line specific. Taken together, we suggest that iron deprivation induces apoptosis at least in some cell types independently of the p53 pathway.
Mineralization of stylohyoid ligament complex in patients with temporomandibular disorders and asymptomatic individuals: a comparative study
Authors: Luz J. G. C. , Rodrigues L. , Chilvarquer I. , Soler J. M. P.
Published: August 2003

Summary  The incidence of mineralization of the stylohyoid ligament complex, according to radiographic findings, was analysed in a group of patients with temporomandibular disorders (TMD), and compared with that of a control group of asymptomatic individuals (AI). Both groups were similar considering the prevalence of the female gender as well as the distribution of cases according to age. ‘Elongated’ was the most frequent radiographic appearance in both groups; ‘partially mineralized’ was the most frequent radiographic pattern in the TMD group; and the lower ramus was the most frequent location of mineralization in both groups. When comparing between groups and according to each class, there was only one significant difference in radiographic appearance, ‘pseudoarticulated’ being more frequent in the TMD group. We can conclude that the occurrence and characteristics of mineralization of stylohyoid ligament complex were similar in TMD patients and AIs.
Fluoride release and uptake by four new fluoride releasing restorative materials
Authors: Dionysopoulos P. , Kotsanos N. , Pataridou A.
Published: August 2003

Summary  The present study compared the initial fluoride release and release following refluoridation of a conventional glass–ionomer Ketac‐Molar (ESPE), a resin‐modified glass–ionomer, Vitremer (3M), and two compomers F‐2000 (3M) and Hytac (ESPE). Fifteen test specimens were prepared for each brand and immersed in deionized water. The fluoride released was measured every 2 days for 22 days. Refluoridation of the test specimens was done with solutions of 0·02, 0·04 and 0·2% NaF for 5 min on days 22, 30, 38 and 46. The fluoride released from recharged specimens was measured every 2 days until day 54. The fluoride release was highest during the first days after preparation, after which it decreased sharply and then more slowly. The four materials became ‘recharged’ with fluoride following repeated fluoride exposure in solution, the 0·2% solution being the most effective. From a clinical point of view, the results from this study imply that all the restorative materials tested may act as intra‐oral devices for the controlled slow release of fluoride at sites at risk of recurrent caries. Fluoride release and uptake by four new fluoride releasing restorative materials.
Relationship of the hyoid bone and posterior surface of the tongue in prognathism and micrognathia
Authors: Yamaoka M. , Furusawa K. , Uematsu T. , Okafuji N. , Kayamoto D. , Kurihara S.
Published: August 2003

Summary  In order to study relationship of the hyoid bone and posterior surface of the tongue in prognathism and micrognathia, we focused on the effect of the tongue on the upper airway lumen in 16 patients with Angle's Class II and 51 patients with Angle's Class III, and assessed the position of the hyoid, the depth from the posterior surface of the tongue, from the bottom of the vallecula and from hyoid bone to the posterior pharyngeal wall using lateral cephalograms. We were able to assess significant correlations between the posterior surface of the tongue and hyoid position in Angle's Class III. However, we found no association between them in Angle's Class II. This could be an adaptive feature of the genioglossus in response to hyoid localization to serve a compensatory role to prevent respiratory impairment in micrognathia at risk of apnoea.
Orientation of craniofacial planes and temporomandibular disorder in young adults with normal occlusion
Authors: Ciancaglini R. , Colombo‐Bolla G. , Gherlone E. F. , Radaelli G.
Published: August 2003

Summary  The aim of this study was to investigate the relationship between orientation of craniofacial planes relative to the true horizontal and temporomandibular disorder (TMD), in normal occlusion. Fourteen university dental students, with full natural dentition and bilateral Angle Class I occlusion, who exhibited signs and symptoms of TMD, were compared with 14 age‐ and sex‐matched healthy controls. Frontal and lateral photographs were taken in natural head position with the subject standing up, clenching a Fox plane and having a facial arch positioned. Photographs were examined by a standardized image analysis. Inter‐pupillary axis, Frankfurt, occlusal and Camper planes were evaluated. In frontal view, the Frankfurt plane was right rotated relative to the true horizontal both in TMD subjects (P < 0·01) and controls (P < 0·05), but rotation was larger in TMD subjects (mean difference between groups, 1·1°, 95% confidence interval, 95% CI, 0·2–2·0°). No significant deviation from the horizontal or difference between groups was observed for the interpupillary axis and occlusal plane. In lateral view, the Frankfurt plane was upward‐orientated relative to the true horizontal in TMD group (mean angular deviation 2·8°, 95% CI, 1·0–4·6°). The occlusal and Camper planes were downward‐orientated in both groups (P < 0·0001), but inclination of occlusal plane tended to be smaller in TMD subjects (mean difference between groups, −3·8°, 95% CI, −7·6–0·1°). Angles between any craniofacial planes did not significantly differ between groups. The findings show that in young adults with normal occlusion, a weak association exists between the orientation of craniofacial planes in natural head position and signs and symptoms of TMD. Furthermore, they suggest that, within this population, TMD might be mainly associated with head posture rather than with craniofacial morphology.
Finite element analysis of the temperature and thermal stress in a postrestored tooth
Authors: Toparli M. , Sasaki S.
Published: August 2003

Summary  The finite element method was used to calculate temperature and thermal stress distribution as a result of hot/cold liquid in the mouth. This numerical study was carried out using axisymmetric finite element models and the tooth model was endodontically treated restored with cast post and cores. The two tooth models evaluated were Ti–Ti alloy and NiCr–AuPd alloy as post material and crown material with porcelain. First, temperature changes on the restored tooth as a result of hot/cold liquid in the mouth were calculated and then the thermal stress as a result of temperature changes were carried out. A fortran computer program was developed for this study. The tooth was assumed isotropic, homogenous, elastic and symmetrical. The distribution of temperature and thermal stress versus time were plotted for four critical points.
Apatite formation on dental ceramics modified by a bioactive glass
Authors: Kontonasaki E. , Papadopoulou L. , Zorba T. , Pavlidou E. , Paraskevopoulos K. , Koidis P.
Published: August 2003

Summary  Restorative dental materials are considered biocompatible without exhibiting any bioactive behaviour. The aim of this study was the investigation of surface structure changes on conventional dental ceramics used in metal‐ceramic restorations modified by a bioactive glass, after immersion in SBF for various time periods. Bioactive glass powder was mixed with porcelain powder with three different weight ratios: 1:1, 1:2, and 2:1. The two powders were mixed with porcelain modelling liquid and the mixture was transferred and spread on the surface of pre‐fabricated ceramic disks. Coated ceramic specimens after being exposed to a specific thermal cycle as it is recommended for dental ceramics were soaked in Simulated Body Fluid (SBF) at 37 °C for various periods of time. After soaking, specimens were studied using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Results revealed the development of a non‐stoichiometric, biological apatite layer on their surface after exposure in SBF for several time periods. The onset of apatite‐layer formation is directly dependent on the amount of bioglass in the coating and its thickness reduces within the specimens of the same bioactive glass–porcelain proportion with time, reaching an average thickness of 15 μm at the longest immersion time, for all the specimens.
Fixed partial dentures: all‐ceramics, fibre‐reinforced composites and experimental systems
Authors: Rosentritt M. , Behr M. , Handel G.
Published: August 2003

Summary  The aim of this in vitro study was to compare the fracture strength of three‐unit FPDs (fixed partial dentures) and three‐unit inlay FPDs after a simulated 5‐year oral wearing period. The restorations were made of a pressable all‐ceramic (Empress 2) and two specially designed, experimentally fixed partial dentures combining ceramics with dental composite. Three‐unit FPDs and inlay FPDs were manufactured and were adhesively luted onto human molars. After thermal cycling and mechanical loading in an artificial environment, the fracture strength was determined. Zircon‐based milled ceramic (Lava) three‐unit FPDs were used as a control. The zircon ceramic and the fibre‐based ceramic three‐unit FPDs showed median fracture values between 1000 and 1400 N. For composite veneered zircon FPDs a fracture strength of about 800 N and for all‐ceramic Empress 2 of about 350 N could be determined. The results for the inlay FPDs were between 1300 N and 1400 N for FRC/ceramic, 1000 N for zircon/composite and 500 N for all‐ceramic restorations. The all‐ceramic showed higher fracture resistance applied as inlay FPDs. The described hybrid techniques combining ceramics and composites could represent an interesting procedure for further investigations and, eventually, clinical implication.