bluuebunny/crossref_metadata_2025 huggingface dataset:
Adding artificial feedback to a simple aquatic ecosystem: the cybernetic nature of ecosystems revisited
Authors: Petersen John E.
Published: November 2004

A cybernetic system can be defined as one controlled by feedback, that is, a system in which input is partially determined by output. I explored the cybernetic properties of a simple planktonic ecosystem by introducing an artificial feedback loop; light energy delivered to the system was linked to the ecosystem's productivity and respiration. Specifically, I programmed a computer to turn lights on and off when dissolved oxygen reached low and high setpoints, respectively. Three treatments were applied that differed in light intensity and in range between high and low setpoints. Experiments were repeated under high and low nutrient conditions. The added feedback did not substantially alter responses to limiting factors from those expected under fixed duration lighting. However, several novel features were observed, including poor coupling between productivity and respiration, similar patterns in energy demand among treatments, and oscillations in primary productivity. These observations can be viewed as support for a holistic, cybernetic view of ecological systems. This view complements the dominant mechanistic‐reductionist perspective on causality in ecosystems. The experimental addition of new feedback is apparently a useful means of investigating the self‐organizational properties of ecosystems and may also improve our understanding of the consequences of anthropogenically induced feedback in natural and managed systems.
Assembly rules for New England ant assemblages
Authors: Gotelli Nicholas J. , Ellison Aaron M.
Published: November 2004

Community assembly rules specify patterns of species co‐occurrence and morphology dictated by interspecific competition. We collected data on the occurrence of ground‐foraging ant species in 22 ombrotrophic bogs and adjacent forest plots of New England to test two general assembly rules: reduced co‐occurrence of species among communities, and even spacing of body sizes of species within communities. We used null models to generate random communities unstructured by competition and evaluated patterns at regional and local spatial scales. At the regional scale, species co‐occurrence in forests, but not bogs, was less than expected by chance, whereas, at the local scale, co‐occurrence in both habitats was not different from random. At the regional scale, spacing of body size distributions was random (in bogs) or aggregated (in forests). At the local scale, body size patterns were weakly segregated in bogs, but random or weakly aggregated in forests. In bogs, size ratio constancy was accompanied by greater generic diversity than expected. Although assembly rules were originally developed for vertebrate communities, they successfully explained some patterns in New England ant assemblages. However, the patterns were contingent on spatial scale, and were distinctly different for bog and forest communities, despite their close proximity and the presence of many shared species in both assemblages. The harsh physical conditions of bogs may act as a habitat filter that alters community assembly rules.
Reduced chemical defence in ant‐plants? A critical re‐evaluation of a widely accepted hypothesis
Authors: Heil Martin , Delsinne Thibaut , Hilpert Andrea , Schürkens Steffen , Andary Claude , Linsenmair K. Eduard , Sousa S. Mario , McKey Doyle
Published: November 2004

Since its original formulation by Janzen in 1966, the hypothesis that obligate ant‐plants (myrmecophytes) defended effectively against herbivores by resident mutualistic ants have reduced their direct, chemical defence has been widely adopted. We tested this hypothesis by quantifying three classes of phenolic compounds (hydrolysable tannins, flavonoids, and condensed tannins) spectrophotometrically in the foliage of 20 ant‐plant and non‐ant‐plant species of the three unrelated genera Leonardoxa,Macaranga and Acacia (and three other closely related Mimosoideae from the genera Leucaena, Mimosa and Prosopis). We further determined biological activities of leaf extracts of the mimosoid species against fungal spore germination (as measure of pathogen resistance), seed germination (as measure of allelopathic activity), and caterpillar growth (as measure of anti‐herbivore defence).

 Condensed tannin content in three of four populations of the non‐myrmecophytic Leonardoxa was significantly higher than in populations of the myrmecophyte. In contrast, we observed no consistent differences between ant‐plants and non‐ant‐plants in the Mimosoideae and in the genus Macaranga, though contents of phenolic compounds varied strongly among different species in each of these two plant groups. Similarly, among the investigated Mimosoideae, biological activity against spore or seed germination and caterpillar growth varied considerably but showed no clear relation with the existence of an obligate mutualism with ants. Our results did not support the hypothesis of ‘trade‐offs’ between indirect, biotic and direct, chemical defence in ant‐plants.  A critical re‐evaluation of the published data suggests that support for this hypothesis is more tenuous than is usually believed. The general and well‐established phenomenon that myrmecophytes are subject to severe attack by herbivores when deprived of their ants still lacks an explanation. It remains to be studied whether the trade‐off hypothesis holds true only for specific compounds (such as chitinases and amides whose cost may be the direct negative effects on plants’ ant mutualists), or whether the pattern of dramatically reduced direct defence of ant‐plants is caused by classes of defensive compounds not yet studied.
Acute Renal Toxic Effect of Amiodarone in Rats
Authors: Morales Ana Isabel , Barata Jose Diogo , Bruges Margarida , Arévalo Miguel Angel , González de Buitrago José Manuel , Palma Patricia , Branco Patricia , Pérez‐Barriocanal Fernando
Published: November 2004

Abstract: Amiodarone is an antiarrhythmic drug now more frequently used after a number of years in which the use had been on the decline due to a number of studies which reported side effects such as chronic toxicity, primarily in the lungs, liver and thyroid glands. Additionally, in some patients an increase in serum creatinine was noted, however the effect of amiodarone on renal function had never been closely examined. Thus, the aim of our study was to analyse the effects of amiodarone on renal function in rats. Experiments were carried out in male Wistar rats divided in two experimental groups: 1) a control group, (n=8), 2) a group that received a daily intraperitoneal injection of amiodarone (50 mg/kg body weight) for 6 days (n=5). At the end of the treatment, renal function was measured by clearance creatinine and acute clearance studies. Renal toxicity was evaluated by urinary N‐acetyl‐glucosamine and alkaline phosphatase. At the end of the experiment, histology studies were done. Rats treated with amiodarone had a higher serum creatinine (182%) and a lower glomerular filtration rate (53%), renal plasma flow (68%) and filtration fraction (62%) than controls. Rats treated with amiodarone also showed an increase in urinary N‐acetyl‐glucosamine (221%) and alkaline phosphatase (4.151%) excretion which corresponds with tubular alterations showed on electron microscopy. In conclusion our data confirm that amiodarone induces acute renal damage in the rat.
Oxidant‐Induced Cell Death in Renal Epithelial Cells: Differential Effects of Inorganic and Organic Hydroperoxides
Authors: Park Sung Min , Jung Hyun Chul , Koak Im Soo , Na Ha Yun , Woo Jae Suk , Jung Jin Sup , Kim Yong Keun
Published: November 2004

Abstract: This study was undertaken in order to examine the roles of lipid peroxidation and poly (ADP‐ribose) polymerase (PARP) activation in oxidant‐induced renal cell death. Opossum kidney cell cultures were used as the renal epithelial cell model, and an inorganic hydroperoxide H2O2 and an organic hydroperoxide t‐butylhydroperoxide were employed as model oxidants. Cell death by both oxidants could be prevented by thiols (dithiothreitol and glutathione), iron chelators (deferoxamine and phenanthroline), and hydroxyl radical scavengers (dimethylthiourea and pyruvate). Phenolic antioxidants N,N′‐diphenyl‐p‐phenylenediamine (DPPD) and butylated hydroxyanisole had no effect on the H2O2‐induced cell death. However, the t‐butylhydroperoxide‐induced cell death was effectively prevented by these antioxidants. The PARP inhibitor 3‐aminobenzamide prevented the cell death induced by H2O2, but not cell death by t‐butylhydroperoxide. The PARP activity was increased in cells exposed to H2O2 but not t‐butylhydroperoxide. Unlike in opossum kidney cells, in rabbit renal cortical slices both oxidants H2O2 and t‐butylhydroperoxide induced cell death through a lipid peroxidation‐dependent and PARP‐independent mechanism. Effects of DPPD and 3‐aminobenzamide on H2O2‐induced cell death in primary cultured rabbit proximal tubular cells were similar to those in opossum kidney cells. These results indicate that 1) the H2O2‐induced cell death in cultured renal epithelial cells is associated with PARP activation but not lipid peroxidation, whereas the t‐butylhydroperoxide‐induced cell death is mediated by lipid peroxidation, and 2) the role of lipid peroxidation in H2O2 cytotoxicity may be different between freshly isolated renal tubular cells and cultured renal epithelial cells.
Five years survival in metastatic non‐small cell lung cancer patients treated with chemotherapy alone or chemotherapy and melatonin: a randomized trial
Authors: Lissoni P. , Chilelli M. , Villa S. , Cerizza L. , Tancini G.
Published: November 2004

Abstract: Numerous experimental data have documented the oncostatic properties of melatonin. In addition to its potential direct antitumor activity, melatonin has proved to modulate the effects of cancer chemotherapy, by enhancing its therapeutic efficacy and reducing its toxicity. The increase in chemotherapeutic efficacy by melatonin may depend on two main mechanisms, namely prevention of chemotherapy‐induced lymphocyte damage and its antioxidant effect, which has been proved to amplify cytotoxic actions of the chemotherapeutic agents against cancer cells. However, the clinical results available at present with melatonin and chemotherapy in the treatment of human neoplasms are generally limited to the evaluation of 1‐year survival in patients with very advanced disease. Thus, the present study was performed to assess the 5‐year survival results in metastatic non‐small cell lung cancer patients obtained with a chemotherapeutic regimen consisting of cisplatin and etoposide, with or without the concomitant administration of melatonin (20 mg/day orally in the evening). The study included 100 consecutive patients who were randomized to receive chemotherapy alone or chemotherapy and melatonin. Both the overall tumor regression rate and the 5‐year survival results were significantly higher in patients concomitantly treated with melatonin. In particular, no patient treated with chemotherapy alone was alive after 2 years, whereas a 5‐year survival was achieved in three of 49 (6%) patients treated with chemotherapy and melatonin. Moreover, chemotherapy was better tolerated in patients treated with melatonin. This study confirms, in a considerable number of patients and for a long follow‐up period, the possibility to improve the efficacy of chemotherapy in terms of both survival and quality of life by a concomitant administration of melatonin. This suggests a new biochemotherapeutic strategy in the treatment of human neoplasms.
Aluminum‐induced pro‐oxidant effects in rats: protective role of exogenous melatonin
Authors: Esparza J.L. , Gómez M. , Romeu M. , Mulero M. , Sánchez D.J. , Mallol J. , Domingo J.L.
Published: November 2004

Abstract: In recent years, it has been suggested that oxidative stress is a feature of Alzheimer's disease in which aluminum (Al) could exacerbate oxidative events. The goal of the present study was to assess in rats the pro‐oxidant effects induced by Al exposure, as well as the protective role of exogenous melatonin. Two groups of male rats were intraperitoneally injected with Al only or melatonin only, at doses of 5 and 10 mg/kg/day, respectively for 8 wk. During this period, a third group of animals received Al (5 mg/kg/day) and melatonin (10 mg/kg/day). At the end of the treatment period, rats were anesthesized and arterial blood was obtained. Thereafter, animals were killed and liver and brain (cortex, hippocampus and cerebellum) were removed. These tissues were processed to examine oxidative stress markers: glutathione transferase (GST), reduced glutathione (GSH), oxidized glutathione (GSSG), superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT), thiobarbituric acid reactive substances (TBARS), as well as protein content. Samples of these tissues were also used to determine Al, Fe, Mn, Cu and Zn concentrations. The results show that Al exposure promotes oxidative stress in different neural areas, including those in which Al concentrations were not significantly increased. The biochemical changes observed in neural tissues show that Al acts as pro‐oxidant, while melatonin exerts an antioxidant action in Al‐treated animals. The protective effects of melatonin against cellular damage caused by Al‐induced oxidative stress, together with its low toxicity, make melatonin worthy of investigation as a potential supplement to be included in the treatment of neurological disorders in which the oxidative effects must be minimized.
Changes in brain amino acids and nitric oxide after melatonin administration in rats with pentylenetetrazole‐induced seizures
Authors: Bikjdaouene Leila , Escames Germaine , León Josefa , Ferrer José M. R. , Khaldy Hoda , Vives Francisco , Acuña‐Castroviejo Darío
Published: November 2004

Abstract: We examined the effect of melatonin on brain levels of amino acids and nitric oxide (NO) after pentylenetetrazole (PTZ)‐induced seizures in rats. Animals were treated with melatonin (10–160 mg/kg, i.p.) 30 min before PTZ administration (100 mg/kg, s.c.), and were killed 3 hr later. At the dose of 80 mg/kg, melatonin significantly increased the latency (5.7–12.7 min) and decreased the duration (31.2–18.4 s) of the first seizure, reducing PTZ induced mortality from 87.5 to 25%. After kill, brains were removed and neurotransmitters and nitrite levels measured in prefrontal cortex (PF), parieto‐temporal cortex (PF), striatum (ST), hippocampus (HP) and brain stem (BS) by high performance liquid chromatography. PTZ treatment increased glutamine levels in all brain areas studied, without changes in glutamate, gamma‐amino butyric acid (GABA) and glycine. Aspartate and taurine increased in PF and PT and in HS and PT, respectively. Melatonin administration displayed a dose‐dependent effect. At doses of 10–40 mg/kg, melatonin counteracted the PTZ‐induced glutamine increase and reduced both glutamate and asparatate levels in the studied areas, with minor changes in GABA and glycine content. At doses of 80 and 160 mg/kg, the levels of glutamine, and glutamate, and to a lesser extent aspartate increased, whereas serine levels did not change. These two doses of melatonin also increased taurine, GABA and glycine in most brain areas studied. Treatment with melatonin (40–160 mg/kg) significantly decreased nitrite content in PT cortex, ST and BS areas of epileptic rats, without changes in the other brain regions. The results suggest that the anticonvulsant property of melatonin involves a modulation of both brain amino acids and NO production.
Wound healing assessment using 20 MHz ultrasound and photography
Authors: Dyson M. , Moodley S. , Verjee L. , Verling W. , Weinman J. , Wilson P.
Published: November 2004

Background/aims To compare two non‐invasive techniques of assessing wound healing, photography and high resolution ultrasound (HRUS) scanning, in experimentally induced full‐thickness human skin wounds.

Methods Punch biopsy wounds, 4 mm in diameter, were made aseptically through locally anaesthetised skin on the anterior (volar) surface of the non‐dominant forearm, 3 cm below the base of the cubital fossa, of 20 human participants. The wounds were treated with a topical antibiotic and covered for 3 days with Mepore sterile dressings. Wound healing was assessed on post‐operative days 3, 7, 14 and 21 from photographs and HRUS B‐scans. All photographs were taken of the wound site and adjacent intact skin under standardised conditions. The prints obtained were examined visually and digitised. Digital HRUS B‐scans were taken through the centre of the wound bed and the adjacent intact skin parallel to the epidermis. Using the scanner's calibrated linear measurement capability, the wound width was measured adjacent to the deep surface of the scab, at the base of the wound, and midway between these two levels.

Results The wound margins were more clearly defined in the HRUS scans than in the photographs of the wounds; in some of the latter the scab masked the wound margins. Changes in the surface width of the wound were affected by the time of scab dehiscence, which varied between volunteers. There was less individual variation in the width of the base of the wound, as measured from the HRUS scans.

Conclusions In contrast to photography, which allows recording of changes in the superficial aspect of the wound only, HRUS scanning permits the quantitative assessment of structural changes deep within the wound. Temporal changes in the width of the base of the wound can be used as an indication of the progress of repair.
Automated epiluminescence microscopy—tissue counter analysis using CART and 1‐NN in the diagnosis of Melanoma
Authors: Gerger Armin ,   Wilhelm Stolz, Pompl Rene , Smolle Josef
Published: November 2004

Background/purpose: In tissue counter analysis, digital images are overlayed with regularly distributed measuring masks (elements) of equal size and shape, and the digital contents (grey level, colour and texture parameters) of each element are used for statistical analysis. In this study we assessed the applicability of tissue counter analysis and machine learning algorithms on tumour segmentation and diagnostic discrimination of benign and malignant melanocytic skin lesions.

Methods: A total of 369 standardised dermatoscopic images (93 melanomas, 276 benign nevi) were evaluated. The Classification and Regression Tree (CART) analysis was performed in order to differentiate between melanocytic skin lesions and surrounding skin. Instance‐based learning (1‐NN) was tested for differentiating between benign and malignant tumour elements. For diagnostic assessment, only the percentage of elements suggestive for malignancy in each lesion was used.

Results: Evaluation of a total of 369 melanocytic skin lesions showed a suitable segmentation of the tumour portion in 97.6%. When instance‐based learning was applied to an independent test set, a threshold value of 27.4% of elements suggestive for malignancy recognised 35 out of 35 melanomas and 100 out of 101 nevi (sensitivity 100%, specificity 99%, positive predictive value 97.2%, negative predictive value 100%).

Conclusion: Tissue counter analysis combined with machine learning algorithms turned out to be a useful method for diagnostic purposes in epiluminescence microscopy.
Apoptosis in oral mucosa: lessons from the crypt. A commentary
Authors: Potten CS
Published: November 2004

The programmed removal of individual isolated cells from a tissue during development, in the adult steady state, and in pathological abnormalities, is an important regulated process that counter‐balances the cells produced due to cell division, and compliments differentiation in the overall tissue homeostatic mechanisms. In stratified epithelium, apoptosis can sometimes be difficult to identify and end‐labelling techniques such as TUNEL are difficult to optimise and validate. In the columnar epithelium of the small intestine, apoptosis is easy to recognise by virtue of the morphological changes seen in dying cells in routine paraffin sections. The dying cells fragment and the apoptotic fragments can be reliably counted. Because of the precise cell positional relationship between hierarchical status in the lineage and cell position in the tissue, the cell death can be related to the hierarchical status of the dying cells. In the normal steady state in healthy epithelium a small proportion of stem cells are constantly dying. This p53‐independent apoptosis is interpreted as part of the homeostatic regulation of stem cell numbers. After exposure to low levels of genotoxic agents, such as radiation, some stem cells in this tissue are very susceptible to apoptosis induction in a p53‐dependent fashion. This has been interpreted to be a genome protective mechanism that accounts at least in part for the unexpected low incidence of cancer in this rapidly proliferating, large mass of tissue within the gastrointestinal tract.
Exfoliative cytology: a helpful tool for the diagnosis of paracoccidioidomycosis
Authors: Cardoso SV , Moreti MM , Costa IM , Loyola AM
Published: November 2004

OBJECTIVE: To describe the main cytological findings associated with smears collected from oral lesions of paracoccidioidomycosis and to appraise the use of cytology as a diagnostic tool for the disease.

STUDY DESIGN: Cytological smears and biopsies were collected from 40 lesions with a clinical suspicion of paracoccidioidomycosis. Evaluation of the sensitivity, specificity, positive and negative predictive values, accuracy and the positive likeness ratio of the oral smear when compared with the histological diagnosis, was performed. The latter is considered the ‘gold standard’ for comparison.

RESULTS: The main morphological findings were the rounded‐shaped, birefringent and multiple‐budded fungi, Langhans' giant cells and epithelioid cells. The following associative measures were found: sensitivity, 67.9%; specificity, 91.7%; positive predictive value, 95.0%; negative predictive value, 55.0%; accuracy, 75.0%; and positive likeness ratio, 8.14.

CONCLUSION: The cytological findings of paracoccidioidomycosis are characteristic and cytology is accurate in the diagnosis of the disease. Positive patients should be treated. Negative patients should be submitted to biopsy to confirm or to dismiss the diagnosis of this mycosis.
LongoVital® and herpes labialis: a randomised, double blind, placebo‐controlled study
Authors: Pedersen A
Published: November 2004

OBJECTIVE: LongoVital (LV) (DK. Reg. No. 5178/75) is a herbal‐based tablet enriched with the recommended daily doses of vitamins. The present study was undertaken to investigate possible prevention of recurrent herpes labialis (RHL) during 4 months' daily intake of LV.

DESIGN: Placebo‐controlled, double‐blind, randomised, clinical trial.

SUBJECTS: Fifty‐two patients with a minimum of 4 yearly HL episodes.

METHODS: The patients were given either LV or placebo for 4 months and followed‐up for another 4 months. The number, duration and maximal size of lesions were assessed.

RESULTS: Twenty‐seven patients (Group A) received LV and 25 patients placebo (Group B). There were no statistically significant differences between Group A and Group B with respect to number, duration and size of lesions. Within Group A, however, there was a decrease in all three parameters after 2 months' intake of LV (P < 0.05). The decrease in the number of HL episodes in Group A lasted during the entire follow‐up period (P < 0.05). At the end of the medication period, significantly more patients in Group A than in Group B assessed the number and duration of recurrences to be reduced compared with before the trial (P < 0.05).

CONCLUSION: LV was not superior to placebo in the prevention of RHL although subjective assessment was in favour of LV, and the LV group had less episodes after 2 months on the tablets.
Effect of Actinobacillus actinomycetemcomitans protease on the proliferation of gingival epithelial cells
Authors: Wang P‐L , Azuma Y , Shinohara M , Ohura K
Published: November 2004

OBJECTIVE: Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) has been implicated as an important pathogen in periodontal disease. The aim of this report is to examine the effect of in vitro application of A. actinomycetemcomitans protease on the cell growth, DNA synthesis, and fibronectin level of human gingival epithelial cells.

MATERIALS AND METHODS: A. actinomycetemcomitans protease was isolated from the culture supernatant of A. actinomycetemcomitans. Human gingival epithelial cells were incubated in the presence or absence of A. actinomycetemcomitans protease (0.01, 0.1, or 1 U) for 48 h. The proliferation of cells were tested with the MTT assay and the BrdU assay. The fibronectin level was examined by flow cytometric analysis.

RESULTS: The cell growth rate, DNA synthesis rate, and fibronectin level of the gingival epithelial cells that had been incubated with protease, were lower than the respective values in the untreated gingival epithelial cells; as the dose of A. actinomycetemcomitans protease increased, the cell growth rate, DNA synthesis rate, and fibronectin level of the gingival epithelial cells decreased. A. actinomycetemcomitans protease may inhibit the proliferation of human gingival epithelial cells.

CONCLUSIONS: This protease may play a key role as a major virulence factor in the development of periodontal disease.
Prevalence of tongue lesions in Hungarian children
Authors: Vörös‐Balog T , Vincze N , Bánóczy J
Published: November 2004

OBJECTIVE:  The aim of this study was to investigate the prevalence of tongue lesions in Hungarian children in relation to age, sex, systemic diseases and allergies.

MATERIAL AND METHODS:  A total of 1017 preschool and school children aged 1–14 years were examined. The age, sex and tongue lesions diagnosed were recorded together with any history of systemic diseases and allergies.

RESULTS:  Tongue lesions were found in 35.11% of all the children examined. Fissured tongue was the most frequent lesion (29.2%), apparently associated with age and sex. It occurred more commonly in boys, and in older children, than in girls and younger children. Geographic tongue was found in 5.7%, occurred more often in boys, and a relationship existed between fissured and geographic tongue. Among the children with geographic tongue 44.82% also had fissured tongue. These findings agree in general with the epidemiological data reported on population samples elsewhere in the world. Crenated tongue occurred in 0.68%, central papillary atrophy in 0.78%, and partial ankyloglossia in 0.88% of the children examined: confirming the rarity of these lesions. Although there was no obvious correlation with systemic diseases, geographic tongue appeared to be coincident with a history of allergic diathesis in some cases.

CONCLUSION:  In some cases early recognition of tongue lesions may provide useful diagnostic markers for some diseases.
Intraoral perineurioma: report of a case with a review of the literature
Authors: Meer S , Coleman H , Altini M
Published: November 2004

Perineurioma is a rare benign peripheral nerve sheath tumour that occurs as an intraneural or extraneural form. To the best of our knowledge, this is the second reported case of an intraoral submucosal extraneural perineurioma. The tumour was symptomless, measured 2 cm in diameter and occurred in the nasolabial fold of a 46‐year‐old black female. Awareness of the occurrence of this neoplasm in the oral cavity is important to promote detection and differentiation from other benign spindle tumours, which occur intraorally. All reported cases of perineurioma have been benign and cure is effected by localized surgical excision.
GSTM1 enzyme concentration and enzyme activity in correlation to the genotype of detoxification enzymes in squamous cell carcinoma of the oral cavity
Authors: Gronau S , Koenig‐Greger D , Jerg M , Riechelmann H
Published: November 2004

BACKGROUND:  Differences in genotype and phenotype of detoxification genes could be one reason for conflicting results in studies dealing with gene polymorphisms as susceptibility factors for tobacco associated cancer.

OBJECTIVES:
 The objective of this study was to investigate gene polymorphisms of detoxification enzymes and to determine whether the enzyme concentration and activity of glutathione S transferase

μ 1 correlates with the genotype in patients with cancer of the oral cavity.

MATERIAL AND METHODS:
 In 73 cancer patients and 136 matched healthy controls, the polymorphisms of glutathione S‐transferase
μ
1 and
θ (GSTM/GSTT), cytochrome p450 1A1 and CYP2D6 were detected. Simultaneously, GSTM1 protein concentration and total GSTM1‐activity were determined.

RESULTS:  Only the coincidence of GSTM1 and GSTT null genotype was associated with oral cavity cancer. GSTM1 protein concentration and enzyme activity in null‐genotype patients was significantly lower than in GSTM1‐allele‐carrier. But the enzyme concentration did not correlate with the activity.

CONCLUSION:  We assume that detoxification enzymes are functionally redundant and that only the simultaneous deficiency of several detoxification enzymes increases the risk for oral cancer.
Oral mucosal dysplastic lesions and early squamous cell carcinomas: underdiagnosis from incisional biopsy
Authors: Pentenero M , Carrozzo M , Pagano M , Galliano D , Broccoletti R , Scully C , Gandolfo S
Published: November 2004

OBJECTIVES: To evaluate the degree and causes of underdiagnosis of incisional biopsy in oral potentially malignant lesions (PML).

DESIGN: Cross‐sectional retrospective study.

MATERIALS AND METHODS: All pathology slides (incisional biopsy and resection specimen) from 46 patients with oral PML were reviewed and scored blind. The provisional diagnosis was considered in order to provide underdiagnosis or overdiagnosis according to whether this score was lower or higher than the final diagnosis.

MAIN OUTCOME MEASURES: Concordance between the scores for provisional and final diagnoses was compared for reviewed and unreviewed assessments.

RESULTS: Upon review, underdiagnosis significantly decreased from 23.9% to 4.4% (P=0.016, chi‐square with the Yates’ correction). As the underdiagnosis ratio was not significantly influenced by intra‐ or inter‐observer variability, it is likely to be related to pathologists’ interpretation difficulties when examining incisional biopsy specimens.

CONCLUSIONS: The good quality of incisional biopsy samples was demonstrated, but clinicians should be conscious of the possible underdiagnosis by incisional biopsy when planning therapy in suspected early oral squamous cell carcinoma lesions.
Levels of TGFβ1 in gingival crevicular fluid during a 21‐day experimental model of gingivitis
Authors: Wright HJ , Chapple ILC , Matthews JB
Published: November 2004

OBJECTIVE: TGFβ1 is a multifunctional growth factor with both pro‐ and anti‐inflammatory properties. This study aimed to determine levels of TGFβ1 in gingival crevicular fluid (GCF), serum and plasma in the early stages of gingival inflammation.

DESIGN: A 21‐day experimental model of gingivitis employing a split mouth design with a soft vinyl splint used to cover test teeth during brushing.

SUBJECTS: Ten healthy volunteers (mean age 21 years; five males and five females).

METHODS: GCF and blood (with and without EDTA) was collected on days 0, 7, 14 and 21. GCF volumes were measured on a precalibrated Periotron 8000TM. Clinical indices of gingival inflammation and plaque levels were obtained after GCF sampling. Normal brushing resumed after GCF collection on day 21 and final samples were collected on day 35. TGFβ1 and alkaline phosphatase (ALP) levels were determined using enhanced chemiluminescent methods.

RESULTS: Clinical indices and GCF volumes increased at test sites during the 21‐day test period. Concentrations of TGFβ1 and ALP in GCF (test and control), serum and plasma did not change throughout the study (P > 0.3). However, total amounts of TGFβ1 (pg sample−1) and ALP (μIU sample−1) in GCF increased at test sites and were significantly higher than baseline values at days 7, 14 and 21 (P < 0.04). Control sites showed no variation in TGFβ1 or ALP levels throughout the study period (P > 0.35). All parameters at test sites returned to control levels at day 35 (P > 0.3).

CONCLUSION: The data indicate that GCF TGFβ1 levels increase early in plaque‐induced inflammation. Whether the biological consequence of this site‐specific increase is pro‐ or anti‐inflammatory in nature remains to be elucidated.
Changes in soils irrigated with saline groundwater containing excess bicarbonate
Authors: Gardner W. K.
Published: November 2004

Changes in soil properties caused by irrigation with saline groundwater (approx. 2 dS/m) containing excess bicarbonate were measured on Vertosols and Sodosols in the West Wimmera, Victoria, Australia. Irrigation caused soil pH to increase, and where this had risen sufficiently (approx. 8.0), the sodium absorption ratio (SAR) of 1 : 5 soil extracts also increased, presumably due to precipitation of calcium and magnesium carbonates. Salt only accumulated when the SAR of 1 : 5 soil extracts was high. In contrast to previous studies, SAR of the soil extracts was not correlated with exchangeable sodium percentage (ESP) of the exchange complex, nor with soil pH. SAR values rose with irrigation once pH exceeded 8, suggesting that carbonate formation was incomplete due to insufficient bicarbonate. The results imply that gypsum application may ameliorate soil properties even if amounts applied are not sufficient to alter ESP.
Indices of soil nitrogen availability in five Tasmanian Eucalyptus nitens plantations
Authors: Moroni M. T. , Smethurst P. J. , Holz G. K.
Published: November 2004

Several soil analyses were used to estimate available N in surface soils (0–10 cm) over a 2-year period at 5 sites that supported 1- to 4-year-old Eucalyptus nitens plantations, and once in subsoils (10–120 cm) at 3 of these sites. Soils were derived from basalt (1 site previously pasture, 1 Pinus radiate, and 2 native forest) or siltstone (previously native forest). Soil analyses examined were total N, total P, total C, anaerobically mineralisable N (AMN), hot KCl-extractable N (hot KCl-N), and NH4+ and NO3– in soil solution and KCl extracts. AMN, KCl-extractable NH4+ and NO3–, and soil solution NH4+ and NO3– varied considerably with time, whereas hot KCl-N, total N, total P, and total C were temporally stable except for a gradual decline in total C with time at one site. Only total P was correlated with net N mineralisation (NNM) across all sites (r2 = 0.91, P < 0.05, n = 5). At 2–3 years after planting, soil solution and KCl-extractable NO3– dropped below 0.1 mm N and 1 μg N/g soil, respectively, at sites with NNM ≤24 kg N/ha.year (n = 3). Sites with NNM ≤24 kg N/ha.year also had ≤0.8 Mg P/ha. Although concentrations of indices of soil N availability decreased with depth, the contribution of subsoil (10–120 cm depth) to total profile N availability was estimated to be at least twice that of the top 10 cm. At an ex-pasture site, high concentrations of mineral N were found at 75–105 cm depths (KCl-extractable N, 289.3 μg N/g soil; 2.8 mm mineral N in soil solution), which may have become available to plantations as their root systems developed.
The determination of urea in soil extracts and related samples—a review
Authors: Lambert David F. , Sherwood John E. , Francis Paul S.
Published: November 2004

Although the dominant methods for the determination of urea in clinical applications incorporate selective enzymatic hydrolysis of urea, the determination of urea in soil extracts is complicated by the presence of urease inhibitors. The spectrophotometric determination of urea with an acidic solution diacetyl monoxime and semicarbazide is a viable option but traditional manual procedures are time-consuming. New variations on these procedures, based on microplates or flow-injection analysis methodologies, allow a far greater number of samples to be analysed with high precision and sensitivity.
Visualization of the internal mammary artery via the hepatic falciform artery in a patient with hepatocellular carcinoma
Authors: Baba Y. , Hokotate H. , Nakajo M.
Published: November 2004

The hepatic falciform artery is a small vessel that arises as a terminal branch of the middle or left hepatic artery. Its anatomy and clinical importance have been described in several recent reports. During dissection of a cadaver, this artery is generally found connected with the ensiform branch of the internal mammary artery. However, to our knowledge, anastomosis has not previously been described radiologically.
Long-term results and quality of life after endovascular treatment of venous malformations in the face and neck
Authors: Rautio R. , Laranne J. , Kähärä V. , Saarinen J. , Keski-Nisula Leo
Published: November 2004

Purpose: To evaluate the long-term results of endovascular sclerotherapy in treating venous and venocapillary malformations of the face and neck region, and to assess the quality of life after treatment.

Material and Methods: Twenty consecutive patients with endovascularly treated venous and capillary-venous malformation of the face and neck were invited to attend for clinical control and magnetic resonance (MR) imaging. To evaluate the quality of life after treatment, patients were asked to fill in a questionnaire which included 20 multiple-choice questions exploring 4 dimensions: psychological, physical, and social functioning, and pain.

Results: In 14 patients, symptoms and MR findings improved, while in 6 patients there was no improvement. Results concerning quality of life showed that most patients did well after endovascular treatment. Patients with venous malformations of the tongue had a worse outcome. Patients under the age of 16 at the beginning of the treatment and patients clinically followed by physicians specialized in vascular malformations had a better quality of life.

Conclusion: Endovascular treatment for venous malformations is effective. Results and quality of life proved to be better when the endovascular treatment was begun before puberty and the patients had regular clinical controls after therapy.
Diagnosis of splanchnic artery aneurysms and pseudoaneurysms, with special reference to contrast enhanced 3D magnetic resonance angiography: a review
Authors: Pilleul F. , Beuf O.
Published: November 2004

Splanchnic artery aneurysms are rare. In the past, conventional angiography was the only way to detect them, but today non-invasive techniques are available. Breath-hold contrast-enhanced 3D magnetic resonance angiography has become a routine examination for evaluation of the aorta and its visceral branches. In this article, we briefly discuss the technical aspects of 3D contrast-enhanced magnetic resonance angiography and illustrate various splanchnic artery aneurysms-pseudoaneurysms with their main characteristics.
Female paraurethral leiomyoma: ultrasonographic and magnetic resonance imaging findings
Authors: Pavlica P. , Bartolone A. , Gaudiano C. , Barozzi L.
Published: November 2004

Primary benign paraurethral tumors in females are observed only rarely. They may occasionally be detected at physical examination or present with symptoms of bladder outlet obstruction. A leiomyoma originating from the smooth muscle fibers of the urethra in a 43-year-old woman is reported. The benign nature of the lesion was suspected on the basis of transvaginal ultrasonography and magnetic resonance imaging. Surgical enucleation was performed and light microscopy showed a well-differentiated smooth muscle tumor.
Accuracy of microCT in the quantitative determination of the degree and distribution of mineralization in developing bone
Authors: Mulder L. , Koolstra J. H. , Van Eijden T. M. G. J.
Published: November 2004

Purpose: To evaluate the accuracy and applicability of a commercially available microCT system for comparative measurements of the degree and distribution of mineralization of developing bone.

Material and Methods: Homogeneous K2HPO4 solutions with different concentrations (range 0-800 mg/cm3) were used to assess the accuracy of a microCT system equipped with a polychromatic X-ray source. Both high (45 kV) and low (70 kV) tube peak voltages were explored. The resulting attenuation was compared with calculated theoretical attenuation values to estimate the accuracy. As an example of its applicability, the method was used to assess changes in the degree of mineralization of various regions of the mandible from two pigs of different developmental age.

Results: On average, the estimated error of the measured linear attenuation was 10% or less. Accuracy was dependent on the average mineral concentration, the size of the sample, and the energy of the X-ray beam. The accuracy of the microCT system appeared sufficient to distinguish regional differences in the degree of mineralization within and between specimens of developing mandibular bone. Furthermore, the resolution of the system allowed identification of different degrees of mineralization within trabeculae.

Conclusion: Accuracy of microCT with polychromatic radiation can be considered adequate for assessment of the degree of mineralization of developing bone. Therefore, this method provides a three-dimensional means by which to simultaneously investigate the bone structure as well as the degree of mineralization during development in a non-destructive manner and with high resolution.
Schwannoma of the esophagus: computed tomography and endosonographic findings of a special type of schwannoma
Authors: Vinhais S. N. , Cabrera R. A. , Nobre-Leitão C. , Cunha T. M.
Published: November 2004

Schwannomas of the digestive tract are uncommon benign tumors seldom located in the esophagus. We present a case of intramural esophageal schwannoma with histopathological correlation evaluated by computed tomography and endoscopic ultrasonography. The imaging findings are described and other relevant features of schwannomas of the esophagus are discussed.
Age-related CD8 T Cell Clonal Expansions Constrict CD8 T Cell Repertoire and Have the Potential to Impair Immune Defense
Authors: Messaoudi Ilhem , LeMaoult Joël , Guevara-Patino Jose A. , Metzner Beatrix M. , Nikolich-Žugich Janko
Published: November 2004

Peripheral T cell diversity is virtually constant in the young, but is invariably reduced in aged mice and humans. CD8+ T cell clonal expansions (TCE) are the most drastic manifestation of, and possible contributors to, this reduced diversity. We show that the presence of TCE results in reduced CD8+, but not CD4+, T cell diversity, and in functional inability to mobilize parts of the CD8+ T cell repertoire affected by TCE. In the model of herpes simplex virus (HSV)-1 infection of B6 mice, >90% of the responding CD8+ T cells use Vβ10 or Vβ8 and are directed against a single glycoprotein B (gB498-505) epitope, gB-8p. We found that old animals bearing CD8+ TCE within Vβ10 or Vβ8 families failed to mount an effective immune response against HSV-1, as judged by reduced numbers of peptide-major histocompatibility complex tetramer+ CD8 T cells and an absence of antiviral lytic function. Furthermore, Vβ8 TCE experimentally introduced into young mice resulted in lower resistance to viral challenge, whereas Vβ5+ TCE induced in a similar fashion did not impact viral resistance. These results demonstrate that age-related TCE functionally impair the efficacy of antiviral CD8+ T cell immunity in an antigen-specific manner, strongly suggesting that TCE are not the mere manifestation of, but are also a contributing factor to, the immunodeficiency of senescence.
Insufficient Production and Tissue Delivery of CD4+Memory T Cells in Rapidly Progressive Simian Immunodeficiency Virus Infection
Authors: Picker Louis J. , Hagen Shoko I. , Lum Richard , Reed-Inderbitzin Edward F. , Daly Lyn M. , Sylwester Andrew W. , Walker Joshua M. , Siess Don C. , Piatak Michael , Wang Chenxi , Allison David B. , Maino Vernon C. , Lifson Jeffrey D. , Kodama Toshiaki , Axthelm Michael K.
Published: November 2004

The mechanisms linking human immunodeficiency virus replication to the progressive immunodeficiency of acquired immune deficiency syndrome are controversial, particularly the relative contribution of CD4+ T cell destruction. Here, we used the simian immunodeficiency virus (SIV) model to investigate the relationship between systemic CD4+ T cell dynamics and rapid disease progression. Of 18 rhesus macaques (RMs) infected with CCR5-tropic SIVmac239 (n = 14) or CXCR4-tropic SIVmac155T3 (n = 4), 4 of the former group manifested end-stage SIV disease by 200 d after infection. In SIVmac155T3 infections, naive CD4+ T cells were dramatically depleted, but this population was spared by SIVmac239, even in rapid progressors. In contrast, all SIVmac239-infected RMs demonstrated substantial systemic depletion of CD4+ memory T cells by day 28 after infection. Surprisingly, the extent of CD4+ memory T cell depletion was not, by itself, a strong predictor of rapid progression. However, in all RMs destined for stable infection, this depletion was countered by a striking increase in production of short-lived CD4+ memory T cells, many of which rapidly migrated to tissue. In all rapid progressors (P < 0.0001), production of these cells initiated but failed by day 42 of infection, and tissue delivery of new CD4+ memory T cells ceased. Thus, although profound depletion of tissue CD4+ memory T cells appeared to be a prerequisite for early pathogenesis, it was the inability to respond to this depletion with sustained production of tissue-homing CD4+ memory T cells that best distinguished rapid progressors, suggesting that mechanisms of the CD4+ memory T cell generation play a crucial role in maintaining immune homeostasis in stable SIV infection.
Klebsiella singaporensis sp. nov., a novel isomaltulose-producing bacterium
Authors: Li Xianzhen , Zhang Daohai , Chen Feng , Ma Jie , Dong Yihu , Zhang Lianhui
Published: November 2004

Cells of strain LX3T, isolated from soil, were Gram-negative, facultatively anaerobic, non-motile, capsulated and non-endospore-forming straight rods, able to grow at 10 °C, unable to produce gas from lactose at 45 °C and unable to produce indole. The isolate converted sucrose to isomaltulose and did not produce detectable glucose by-products. The G+C content of the DNA was 56·4 mol%. Furthermore, comparison of 16S rRNA and rpoB gene sequences showed that the isolate clearly belongs to the genus Klebsiella. The closest phylogenetic relative was Klebsiella pneumoniae, there being 99·3 and 97·5 % similarity in 16S rRNA and rpoB gene sequences, respectively. DNA–DNA hybridization analysis demonstrated a very low level of relatedness to other members of the genus Klebsiella, indicating that the isolated strain and other species in the genus Klebsiella were not related at the species level. The isolate could be differentiated from other previously described members of the genus Klebsiella on the basis of phenotypic differences and 16S rRNA and rpoB gene sequence divergence, together with DNA–DNA reassociation data. Therefore, it is proposed that strain LX3T (=DSM 16265T=JCM 12419T) should be classified as the type strain of a novel species of genus Klebsiella, Klebsiella singaporensis sp. nov.