[Periapical surgery with histologic examination of the periapical lesion. A case report]

Periapical surgery is required when periradicular pathosis associated with endodontically treated teeth cannot be resolved by nonsurgical root canal therapy (retreatment), or when retreatment was unsuccessful, not feasible or contraindicated. Endodontic failures can occur when irritants remain within the confines of the root canal, or when an extraradicular infection cannot be eradicated by orthograde root canal treatment. Foreign-body reponses towards filling materials, towards cholesterol crystals or radicular cysts might prevent complete periapical healing. Following enhanced microsurgical techniques in the last years the success rates of apical surgery have improved considerably. The aim of the current case report is to describe the therapeutical approach to a persistent periapical lesion and its histologic examination.

Novel Features of the Prenatal Horn Bud Development in Cattle (Bos taurus).

Whereas the genetic background of horn growth in cattle has been studied extensively, little is known about the morphological changes in the developing fetal horn bud. In this study we histologically analyzed the development of horn buds of bovine fetuses between ~70 and ~268 days of pregnancy and compared them with biopsies taken from the frontal skin of the same fetuses. In addition we compared the samples from the wild type (horned) fetuses with samples taken from the horn bud region of age-matched genetically hornless (polled) fetuses. In summary, the horn bud with multiple layers of vacuolated keratinocytes is histologically visible early in fetal life already at around day 70 of gestation and can be easily differentiated from the much thinner epidermis of the frontal skin. However, at the gestation day (gd) 212 the epidermis above the horn bud shows a similar morphology to the epidermis of the frontal skin and the outstanding layers of vacuolated keratinocytes have disappeared. Immature hair follicles are seen in the frontal skin at gd 115 whereas hair follicles below the horn bud are not present until gd 155. Interestingly, thick nerve bundles appear in the dermis below the horn bud at gd 115. These nerve fibers grow in size over time and are prominent shortly before birth. Prominent nerve bundles are not present in the frontal skin of wild type or in polled fetuses at any time, indicating that the horn bud is a very sensitive area. The samples from the horn bud region from polled fetuses are histologically equivalent to samples taken from the frontal skin in horned species. This is the first study that presents unique histological data on bovine prenatal horn bud differentiation at different developmental stages which creates knowledge for a better understanding of recent molecular findings.

Salient features of the coronary collateral circulation and its clinical relevance

The coronary collateral circulation provides an alternative source of blood supply to myocardium jeopardised by ischaemia. Collaterals enlarge with obstructive coronary artery disease to allow bulk flow, but blood flow deliverable by the native, pre-formed collateral extent can already be sizeable. Genetic determinants contribute significantly to the wide variability observed in both native collateral extent and its capacity to enlarge, and the severity of the coronary stenosis is the most significant environmental determinant for collateral enlargement. The protective effect of a well-developed coronary collateral circulation translates into relevant improvements in all-cause and cardiac mortality in the acute and chronic phases of coronary artery disease, as well as into a reduction of future adverse cardiovascular events.

Appreciation of cleft lip and palate treatment outcome by professionals and laypeople

The aim of the study was to analyse the aesthetic evaluation of head photographs of treated individuals with clefts by laypeople and professionals and to investigate how certain cephalometric variables could be related to their rating. A set of five standardized head photos (frontal, both laterals, three-quater right and left) of 12 Caucasian patients with treated unilateral cleft lip and palate were presented to 12 adult laypeople, 12 orthodontists, and 12 maxillofacial surgeons. For each set of photos the judges had to answer four questions on a visual analogue scale (VAS). The answers were analysed for intra- and inter-panel level of agreement and correlations of assessments with certain cephalometric parameters were determined. There was a high level of agreement for all assessments of each panel of raters. However, laypeople were less satisfied with lip and nose aesthetics compared to professionals. The three groups were similarly satisfied with the aesthetics of the jaws and the face. The anterior position of the maxilla (SNA) influenced positively professionals' ratings of facial aesthetics. Orthodontists were negatively influenced when the vertical dimension of the face or the distance of the lower lip to E-plane were relatively increased. The latter was the only cephalometric parameter correlated with lower aesthetic scores obtained from laypeople. Professionals report greater satisfaction from the treatment outcome and evaluate cleft consequences with less severity than laypeople. According to cephalometric findings, the relative positions of the lips seem to dominate facial aesthetics' appreciation by laypeople, while specialists appear to focus on different features of the face.

Pleomorphic adenoma of the parotid gland: histopathologic analysis of the capsular characteristics of 218 tumors

BACKGROUND: Histopathologic features of the capsule may have an impact on the recurrence rate of pleomorphic adenomas. METHODS: Retrospective (n = 154) and prospective (n = 64) histologic analysis of the capsular characteristics such as incompleteness, tumor penetration, pseudopodia, and satellite tumors of 218 pleomorphic adenomas. RESULTS: In 160 of the 218 (73%) pleomorphic adenomas, 1 or more capsular characteristics such as incomplete capsule (33%), capsule penetration (26%), pseudopodia (40%), and satellite nodules (13%) were detected. Incomplete capsule and satellite tumors were most frequently seen in the stroma-rich (myxoid) subtype. Capsular penetration and pseudopodia were significantly more common in the prospective group than in the retrospective group (p < .05/<.05). CONCLUSION: Pseudopodia and satellite tumors were more common than reported in the literature. If left in the surrounding salivary gland tissue at surgery, they can lead to recurrences of pleomorphic adenomas of the parotid gland.

Pathology of sarcoptic mange in red foxes (Vulpes vulpes): macroscopic and histologic characterization of three disease stages

Sarcoptic mange is a highly contagious skin disease that can have a devastating impact on affected wild mammal populations. There are notable variations in the clinical and pathologic picture of sarcoptic mange among species and among conspecifics. However, the origin of these variations is unclear. We propose a classification scheme for skin lesions associated with Sarcoptes scabiei infestation to provide a basis for a subsequent risk factor analysis. We conducted a case-control study focused on macroscopic and histologic examination of the skin, using 279 red foxes (Vulpes vulpes) found dead or shot in Switzerland between November 2004 and February 2006. All animals were submitted to gross necropsy following a detailed protocol. Selection criteria for cases (n=147) vs. controls (n=111) were the presence or absence of mange-like lesions, mite detection by isolation or histologic examination, and serologic testing for S. scabiei antibodies. Characteristic features of mange lesions were scored macroscopically in all foxes and histologically in 67 cases and 15 controls. We classified skin lesions and associated necropsy findings into three types of mange: A) early stage (n=45): focal-extensive skin lesions, thin crusts, mild to moderate alopecia, few mites, numerous eosinophils, and mild lymph node enlargement; B) hyperkeratotic, fatal form (n=86): generalized skin lesions, thick crusts with or without alopecia, foul odor, abundance of mites, numerous bacteria and yeasts, numerous lymphocytes and mast cells, severe lymph node enlargement, and emaciation; C) alopecic, healing form (n=16): focal lesions, no crusts, severe alopecia, hyperpigmentation and lichenification, absence of mites, mixed cell infiltration, and rare mild lymph node enlargement. We hypothesize that after stage A, the animal either enters stage B and dies, or stage C and survives, depending on largely unknown extrinsic or intrinsic factors affecting the host ability to control mite infestation.

Activation of the unfolded protein response in human acute myeloid leukemia

There is accumulating evidence for the involvement of the unfolded protein response (UPR) in the pathogenesis of many tumor types in humans. This is particularly the case in rapidly growing solid tumors in which the demand for oxygen and nutrients can exceed the supply until new tumor-initiated blood vessels are formed. In contrast, the role of the UPR during leukemogenesis remains largely unknown. Acute myeloid leukemia (AML) is a genetically heterogeneous clonal disorder characterized by the accumulation of somatic mutations in hematopoietic progenitor cells that alter the physiological regulation of self-renewal, survival, proliferation, or differentiation. The CCAAT/enhancer-binding protein alpha (CEBPA) gene is a key myeloid transcription factor and a frequent target for disruption in AML. In particular, translation of CEBPA mRNA can be specifically blocked by binding of the chaperone calreticulin (CALR), a well-established effector of the UPR, to a stem loop structure within the 5' region of the CEBPA mRNA. The relevance of this mechanism was first elucidated in certain AML subtypes carrying the gene rearrangements t(3;21) or inv(16). In our recent work, we could demonstrate the induction of key effectors of the UPR in leukemic cells of AML patients comprising all subtypes (according to the French-American-British (FAB) classification for human AML). The formation of the spliced variant of the X-box binding protein (XBP1s) was detectable in 17.4% (17 of 105) of AML patients. Consistent with an activated UPR, this group had significantly increased expression of the UPR target genes CALR, the 78 kDa glucose-regulated protein (GRP78), and the CCAAT/enhancer-binding protein homologous protein (CHOP). Consistently, in vitro studies confirmed that calreticulin expression was upregulated via activation of the ATF6 pathway in myeloid leukemic cells. As a consequence, CEBPA protein expression was inhibited in vitro as well as in leukemic cells from patients with activated UPR. We therefore propose a model of the UPR being involved in leukemogenesis through induction of calreticulin along the ATF6 pathway, thereby ultimately suppressing CEBPA translation and contributing to the block in myeloid differentiation and cell-cycle deregulation which represent key features of the leukemic phenotype. From a more clinical point of view, the presence of activated UPR in AML patient samples was found to be associated with a favorable disease course.

Modified complete synovectomy prevents recurrence in synovial chondromatosis of the hip

Synovial chondromatosis of the hip is a rare disorder with few published reports regarding treatment and outcomes, and therefore, selecting the optimal surgical treatment is difficult. We reviewed eight patients with monoarticular synovial chondromatosis of the hip who had joint débridement and a modified total synovectomy performed through a surgical hip dislocation with a trochanteric flip osteotomy. Patients were evaluated for recurrence of disease, progression of osteoarthritis, clinical outcomes, and subsequent reoperations. The minimum followup was 4 years (mean, 6.5 years). At final review, no patient had recurrence of disease. Two patients had progression of osteoarthritis requiring total hip arthroplasties at 5 and 10 years after the initial surgical intervention. These patients did not show recurrent disease on histologic examination of the synovial membrane at the time of the arthroplasty. The six patients with preserved joints were followed up for a mean of 6.2 years. The mean Merle d'Aubigné and Postel score in this group was 16.5 points (range, 15-18 points) at the latest followup. There were no major or minor complications related to this treatment. Our midterm results suggest that open débridement with modified total synovectomy is an effective treatment that prevents recurrence of disease and provides substantial pain relief. Surgical hip dislocation allows safe and complete access to the joint for débridement and synovectomy with no added morbidity.

Fetal thymic involution: a sonographic marker of the fetal inflammatory response syndrome

OBJECTIVE: The purpose of this study was to evaluate whether there is a relationship between the sonographic fetal thymus size and the presence of an intrauterine infection in patients with preterm labor. STUDY DESIGN: Thirty-one women who had been admitted with preterm labor and intact membranes between 24 and 32 weeks of gestation were included. Fetal thymus perimeter was measured sonographically, and amniocentesis for the microbiologic assessment of the amniotic cavity was performed. Placentas and umbilical cords were examined for the presence of chorioamnionitis/funisitis. RESULTS: The prevalence of preterm delivery and intra-amniotic infection was 51.6% (16/31 women) and 32.3% (10/31 women), respectively. In all cases with intrauterine infection and in 23.8% of cases without intrauterine infection, the fetal thymus perimeter was below the 5th percentile for gestational age (10/10 women vs 5/21 women; P < .01). Isolated histologic chorioamnionitis and funisitis were found in 22.6% and 25.8% of fetuses, respectively. The fetal thymus was below the 5th percentile for gestational age in 100%, 71.4%, and 12.5% of patients with histologic signs of funisitis and isolated chorioamnionitis and without histologic signs of infection, respectively. CONCLUSION: Fetal thymus involution in preterm labor patients is strongly associated with funisitis, which is the histologic manifestation of the fetal inflammatory response syndrome.

Transient simulations of the carbon and nitrogen dynamics in northern peatlands: from the Last Glacial Maximum to the 21st century

The development of northern high-latitude peatlands played an important role in the carbon (C) balance of the land biosphere since the Last Glacial Maximum (LGM). At present, carbon storage in northern peatlands is substantial and estimated to be 500 ± 100 Pg C (1 Pg C = 1015 g C). Here, we develop and apply a peatland module embedded in a dynamic global vegetation and land surface process model (LPX-Bern 1.0). The peatland module features a dynamic nitrogen cycle, a dynamic C transfer between peatland acrotelm (upper oxic layer) and catotelm (deep anoxic layer), hydrology- and temperature-dependent respiration rates, and peatland specific plant functional types. Nitrogen limitation down-regulates average modern net primary productivity over peatlands by about half. Decadal acrotelm-to-catotelm C fluxes vary between −20 and +50 g C m−2 yr−1 over the Holocene. Key model parameters are calibrated with reconstructed peat accumulation rates from peat-core data. The model reproduces the major features of the peat core data and of the observation-based modern circumpolar soil carbon distribution. Results from a set of simulations for possible evolutions of northern peat development and areal extent show that soil C stocks in modern peatlands increased by 365–550 Pg C since the LGM, of which 175–272 Pg C accumulated between 11 and 5 kyr BP. Furthermore, our simulations suggest a persistent C sequestration rate of 35–50 Pg C per 1000 yr in present-day peatlands under current climate conditions, and that this C sink could either sustain or turn towards a source by 2100 AD depending on climate trajectories as projected for different representative greenhouse gas concentration pathways.

Measurement of the underlying event in jet events from 7 TeV proton-proton collisions with the ATLAS detector

Distributions sensitive to the underlying event in QCD jet events have been measured with the ATLAS detector at the LHC, based on 37 pb−1 of proton–proton collision data collected at a centre-of-mass energy of 7 TeV. Chargedparticle mean pT and densities of all-particle ET and chargedparticle multiplicity and pT have been measured in regions azimuthally transverse to the hardest jet in each event. These are presented both as one-dimensional distributions and with their mean values as functions of the leading-jet transverse momentum from 20 to 800 GeV. The correlation of chargedparticle mean pT with charged-particle multiplicity is also studied, and the ET densities include the forward rapidity region; these features provide extra data constraints for Monte Carlo modelling of colour reconnection and beamremnant effects respectively. For the first time, underlying event observables have been computed separately for inclusive jet and exclusive dijet event selections, allowing more detailed study of the interplay of multiple partonic scattering and QCD radiation contributions to the underlying event. Comparisonsto the predictions of different Monte Carlo models show a need for further model tuning, but the standard approach is found to generally reproduce the features of the underlying event in both types of event selection.