Monoclonal antibody directed against Neospora caninum tachyzoite carbohydrate epitope reacts specifically with apical complex-associated sialylated beta tubulin

Monoclonal antibodies (mabs) were generated against whole sonicated Neospora caninum tachyzoites as immunogen. Initial ELISA screening of the reactivity of hybridoma culture supernatants using the same antigen and antigen treated with sodium periodate prior to antibody binding resulted in the identification of 8 supernatants with reactivity against putative carbohydrate epitopes. Following immunoblotting, mab6D12 (IgG1), binding a 52/48-kDa doublet, and mab6C6 (IgM), binding a 190/180-kDa doublet, were selected for further studies. Immunofluorescence of tachyzoite-infected cultures localized the corresponding epitopes not to the surface, but to interior epitopes at the apical part of N. caninum tachyzoites. During in vitro tachyzoite to bradyzoite stage conversion, mab6C6 labeling translocated toward the cyst periphery, while for mab6D12 no changes in localization were noted. Upon extraction of tachyzoites with the nonionic detergent Triton-X-100, the 52-kDa band recognized by mab6D12 was present exclusively in the insoluble, cytoskeletal fraction of both N. caninum and Toxoplasma gondii tachyzoites. Tandem mass spectrometry analysis identified this protein as N. caninum beta tubulin. The 48-kDa band labeled by mab6D12 was a Vero cell protein contamination. The protein(s) reacting with mab6C6 could not be conclusively identified by mass spectrometry. Immunofluorescence consistently failed to label T. gondii tachyzoites, indicating that beta tubulin in T. gondii and N. caninum could be differentially modified or that the reactive epitope in T. gondii is masked. Immunogold TEM of isolated apical cytoskeletal preparations and dual immunofluorescence with antibody to tubulin confirmed that mab6D12 binds to the anterior part of apical complex-associated microtubules. The sodium periodate sensitivity of the beta tubulin associated epitope was confirmed by immunoblotting and ELISA, and treatment of N. caninum cytoskeletal proteins with sialidase prior to mab6D12 labeling resulted in a profound loss of antibody binding, suggesting that mab6D12 reacts with sialylated beta tubulin.

Dendritic spikes in apical dendrites of neocortical layer 2/3 pyramidal neurons

Layer 2/3 (L2/3) pyramidal neurons are the most abundant cells of the neocortex. Despite their key position in the cortical microcircuit, synaptic integration in dendrites of L2/3 neurons is far less understood than in L5 pyramidal cell dendrites, mainly because of the difficulties in obtaining electrical recordings from thin dendrites. Here we directly measured passive and active properties of the apical dendrites of L2/3 neurons in rat brain slices using dual dendritic-somatic patch-clamp recordings and calcium imaging. Unlike L5 cells, L2/3 dendrites displayed little sag in response to long current pulses, which suggests a low density of I(h) in the dendrites and soma. This was also consistent with a slight increase in input resistance with distance from the soma. Brief current injections into the apical dendrite evoked relatively short (half-width 2-4 ms) dendritic spikes that were isolated from the soma for near-threshold currents at sites beyond the middle of the apical dendrite. Regenerative dendritic potentials and large concomitant calcium transients were also elicited by trains of somatic action potentials (APs) above a critical frequency (130 Hz), which was slightly higher than in L5 neurons. Initiation of dendritic spikes was facilitated by backpropagating somatic APs and could cause an additional AP at the soma. As in L5 neurons, we found that distal dendritic calcium transients are sensitive to a long-lasting block by GABAergic inhibition. We conclude that L2/3 pyramidal neurons can generate dendritic spikes, sharing with L5 pyramidal neurons fundamental properties of dendritic excitability and control by inhibition.

Correlation of bone defect dimensions with healing outcome one year after apical surgery

This clinical study prospectively evaluated the healing outcome 1 year after apical surgery in relation to bony crypt dimensions measured intraoperatively. The study cohort included 183 teeth in an equal number of patients. For statistical analysis, results were dichotomized (healed versus non-healed cases). The overall success rate was 83% (healed cases). Healing outcome was not significantly related to the level and height of the facial bone plate. In contrast, a significant difference was found for the mean size of the bony crypt when healed cases (395 mm(3)) were compared with non-healed cases (554 mm(3)). In addition, healed cases had a significantly shorter mean distance (4.30 mm) from the facial bone surface to the root canal (horizontal access) compared with non-healed cases (5.13 mm). With logistic regression, however, the only parameter found to be significantly related to healing outcome was the length of the access window to the bony crypt.

Changes of periodontal parameters following apical surgery: a prospective clinical study of three incision techniques

AIM: To evaluate periodontal changes following apical surgery, and to relate changes to the type of incision and to the type of restoration present at the gingival margin (GM). METHODOLOGY: Periodontal parameters [probing depth (PD), level of GM and clinical attachment, plaque and bleeding indices] were recorded at baseline and 1 year following apical surgery. The periodontal changes were calculated and assessed with respect to the incision technique (intrasulcular incision, papilla base incision and submarginal incision), as well as to the presence and type of a restoration margin in contact with the gingiva. RESULTS: One hundred and eighty-four teeth could be evaluated. No significant differences between the three incision techniques were found regarding changes in PDs and plaque index over time. However, significant differences between the intrasulcular and submarginal incisions were found for changes in levels of GM and clinical attachment. For example, with the intrasulcular incision, there was a mean recession of 0.42 mm at buccal sites, whereas using the submarginal incision there was a gain of 0.05 mm. No statistically significant influence could be demonstrated for the presence and type of restoration margins, or the smoking habit of the patient. CONCLUSION: The type of incision was found to affect changes significantly in periodontal parameters within an observation period of 1 year following apical surgery, whereas the restoration margin and smoking habit did not prove to have any significant effect.

Takotsubo cardiomyopathy or transient left ventricular apical ballooning syndrome: A systematic review

BACKGROUND: Transient left ventricular apical ballooning syndrome (TLVABS) is an acute cardiac syndrome mimicking ST-segment elevation myocardial infarction characterized by transient wall-motion abnormalities involving apical and mid-portions of the left ventricle in the absence of significant obstructive coronary disease. METHODS: Searching the MEDLINE database 28 case series met the eligibility criteria and were summarized in a narrative synthesis of the demographic characteristics, clinical features and pathophysiological mechanisms. RESULTS: TLVABS is observed in 0.7-2.5% of patients with suspected ACS, affects women in 90.7% (95% CI: 88.2-93.2%) with a mean age ranging from 62 to 76 years and most commonly presents with chest pain (83.4%, 95% CI: 80.0-86.7%) and dyspnea (20.4%, 95% CI: 16.3-24.5%) following an emotionally or physically stressful event. ECG on admission shows ST-segment elevations in 71.1% (95% CI: 67.2-75.1%) and is accompanied by usually mild elevations of Troponins in 85.0% (95% CI: 80.8-89.1%). Despite dramatic clinical presentation and substantial risk of heart failure, cardiogenic shock and arrhythmias, LVEF improved from 20-49.9% to 59-76% within a mean time of 7-37 days with an in-hospital mortality rate of 1.7% (95% CI: 0.5-2.8%), complete recovery in 95.9% (95% CI: 93.8-98.1%) and rare recurrence. The underlying etiology is thought to be based on an exaggerated sympathetic stimulation. CONCLUSION: TLVABS is a considerable differential diagnosis in ACS, especially in postmenopausal women with a preceding stressful event. Data on longterm follow-up is pending and further studies will be necessary to clarify the etiology and reach consensus in acute and longterm management of TLVABS.

Comparison of periapical radiography and limited cone-beam tomography in posterior maxillary teeth referred for apical surgery

This study compared periapical (PA) radiography and cone-beam tomography (CBT) for preoperative diagnosis in posterior maxillary teeth of consecutive patients referred for possible apical surgery. Images were concurrently analyzed by an oral radiologist and an endodontist to reach consensus in interpretation of the radiographic findings. The final material included 37 premolars and 37 molars with a total of 156 roots. CBT showed significantly more lesions (34%, p < 0.001) than PA radiography. Detecting lesions with PA radiography alone was most difficult in second molars or in roots in close proximity to the maxillary sinus floor. Additional findings were seen significantly more frequently in CBT compared with PA radiography including expansion of lesions into the maxillary sinus (p < 0.001), sinus membrane thickening (p < 0.001), and missed canals (p < 0.05). The present study highlights the advantages of using CBT for preoperative treatment planning in maxillary posterior teeth with apical pathology.

Transient apical ballooning syndrome--clinical characteristics, ballooning pattern, and long-term follow-up in a Swiss population

BACKGROUND: Transient apical ballooning syndrome (TABS) or Takotsubo cardiomyopathy mimics acute ST-elevation myocardial infarction, but is considered to have a good prognosis with only moderate elevation of myocardial enzymes and full recovery of left ventricular function. Although it is increasingly reported, its exact incidence, clinical presentation, and prognosis in non-Asian populations remain largely unknown. OBJECTIVE: To describe the clinical characteristics and long-term follow-up of patients who presented with TABS at our institution over a 3 year-period. METHODS: Patients were retrospectively retrieved from our local database. Patient charts were carefully reviewed and the diagnosis of TABS was based on the Mayo Clinic diagnostic criteria. Moreover, psychosocial stress or gastrointestinal disease was recorded. RESULTS: During the study period, 13,715 coronary angiographies were performed at our institution, including 2459 patients presenting with an acute coronary syndrome (ACS). Forty-one TABS were diagnosed, which represents an incidence of 1.7% of ACS-patients and 0.3% of all coronary angiographies performed, respectively. Mean age was 65 years, with 85% women. Clinical presentations included chest pain, dyspnoea, and cardiogenic shock. A preceding psychological or physical condition perceived as "stress" was reported in 61%. At a mean follow-up of 675+/-288 days, none of the patients died of cardiac causes, but two patients had a recurrence of symptoms. CONCLUSIONS: This is the largest cohort of TABS patients reported out of Europe so far. The good overall prognosis and low likelihood of recurrence were confirmed.

Gingival recession following apical surgery in the esthetic zone: a clinical study with 70 cases

The present study evaluated gingival recession 1 year following apical surgery of 70 maxillary anterior teeth (central and lateral incisors, canines, and first premolars). A visual assessment of the mid-facial aspect of the gingival level and of papillary heights of treated teeth was carried out using photographs taken at pre-treatment and 1-year follow-up appointments. In addition, changes in the gingival margin (GM) and clinical attachment levels (CAL) were calculated with the use of clinical measurements, that is, pre-treatment and 1-year follow-up pocket probing depth and level of gingival margin. Changes in GM and CAL were then correlated with patient-, tooth-, and surgery-related parameters. The following parameters were found to significantly influence changes in GM and CAL over time: gingival biotype (P < 0.05), with thin biotype exhibiting more gingival recession than thick biotype; pre-treatment pocket probing depth (PPD) (P < 0.03), with cases of pre-treatment PPD < 2.5 mm demonstrating more attachment loss than cases of PPD > or = 2.5 mm; and type of incision (P < 0.01), with the submarginal incision showing considerably less gingival recession compared with the intrasulcular incision, papilla-base incision or papilla-saving incision. The visual assessment using pre-treatment and 1-year follow-up photographs did not demonstrate significant changes in gingival level or papillary height after apical surgery. In conclusion, gingival biotype, pre-treatment PPD, and type of incision may significantly influence changes in GM and CAL following apical surgery in maxillary anterior teeth.

Histology of periapical lesions obtained during apical surgery

The aim of this was to evaluate the histology of periapical lesions in teeth treated with periapical surgery. After root-end resection, the root tip was removed together with the periapical pathological tissue. Histologic sectioning was performed on calcified specimens embedded in methylmethacrylate (MMA) and on demineralized specimens embedded in LR White (Fluka, Buchs, Switzerland). The samples were evaluated with light and transmission electron microscopy (TEM). The histologic findings were classified into periapical abscesses, granulomas, or cystic lesions (true or pocket cysts). The final material comprised 70% granulomas, 23% cysts and 5% abscesses, 1% scar tissues, and 1% keratocysts. Six of 125 samples could not be used. The cystic lesions could not be subdivided into pocket or true cysts. All cysts had an epithelium-lined cavity, two of them with cilia-lined epithelium. These results show the high incidence of periapical granulomas among periapical lesions obtained during apical surgery. Periapical abscesses were a rare occasion. The histologic findings from samples obtained during apical surgery may differ from findings obtained by teeth extractions. A determination between pocket and true apical cysts is hardly possible when collecting samples by apical surgery.

Particles induce apical plasma membrane enlargement in epithelial lung cell line depending on particle surface area dose

Background Airborne particles entering the respiratory tract may interact with the apical plasma membrane (APM) of epithelial cells and enter them. Differences in the entering mechanisms of fine (between 0.1 μm and 2.5 μm) and ultrafine ( ≤ 0.1 μm) particles may be associated with different effects on the APM. Therefore, we studied particle-induced changes in APM surface area in relation to applied and intracellular particle size, surface and number. Methods Human pulmonary epithelial cells (A549 cell line) were incubated with various concentrations of different sized fluorescent polystyrene spheres without surface charge (∅ fine – 1.062 μm, ultrafine – 0.041 μm) by submersed exposure for 24 h. APM surface area of A549 cells was estimated by design-based stereology and transmission electron microscopy. Intracellular particles were visualized and quantified by confocal laser scanning microscopy. Results Particle exposure induced an increase in APM surface area compared to negative control (p < 0.01) at the same surface area concentration of fine and ultrafine particles a finding not observed at low particle concentrations. Ultrafine particle entering was less pronounced than fine particle entering into epithelial cells, however, at the same particle surface area dose, the number of intracellular ultrafine particles was higher than that of fine particles. The number of intracellular particles showed a stronger increase for fine than for ultrafine particles at rising particle concentrations. Conclusion This study demonstrates a particle-induced enlargement of the APM surface area of a pulmonary epithelial cell line, depending on particle surface area dose. Particle uptake by epithelial cells does not seem to be responsible for this effect. We propose that direct interactions between particle surface area and cell membrane cause the enlargement of the APM.

Suspended sediment pulse effects in rainbow trout (Oncorhynchus mykiss) - relating apical and systemic responses

To provide an integrated perspective on mineral particle effects in salmonids, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to daily mica particle pulses for 8 and 24 days. On day 8, increased immature erythrocyte proportions indicated a previous stress response. This response was absent on day 24, on which condition factor as well as plasma protein and aspartate aminotransferase activity decreased. The latter two related negatively to the hepato-somatic index, suggesting metabolic adaptations. The hepato-somatic index increased on days 8 and 24, while spleen-somatic index increased on day 24. No histopathological damage occurred in gills, liver, spleen, or kidney. However, splenic melano-macrophages increased on both days, and hyaline degenerations of kidney tubular cells were apparent on day 24. Overall, particle pulses affected rainbow trout more via turbidity rather than by physical damage. We conclude that (i) rainbow trout may adapt to sediment pulses as early as 8 days of exposure and (ii) particle pulses over 24 days can cause structural and metabolic changes in rainbow trout, even when gill damage is absent and apical effects on condition are moderate.

Treatment decisions in 330 cases referred for apical surgery

INTRODUCTION Apical surgery is an important treatment option for teeth with postendodontic apical periodontitis. However, little information is available regarding treatment planning in cases referred for apical surgery. This study evaluated the decisions made in such cases and analyzed the variables influencing the decision-making process. METHODS The study retrospectively assessed clinical and radiographic data of 330 teeth that had been referred to a specialist in apical surgery with regard to the treatment decisions made in those teeth. The clinical and radiographic variables were divided into subcategories to analyze which factors influenced the decision-making process. RESULTS The treatment decisions included apical surgery (59.1%), tooth extraction (25.8%), no treatment (9.1%), and nonsurgical endodontic retreatment (6.1%). Variables that showed statistically significant differences comparing treatment decisions among subcategories included probing depth (P = .001), clinical attachment level (P = .0001), tooth mobility (P = .012), pain (P = .014), clinical signs (P = .0001), length (P = .041) and quality (P = .026) of the root canal filling, and size (P = .0001) and location (P = .0001) of the periapical lesion. CONCLUSIONS This study shows that apical surgery was the most frequently made treatment decision in teeth referred to a specialist in apical surgery, but every fourth tooth was considered nonretainable and was scheduled for extraction. The data showed that the most common variables that influenced the decision to extract teeth were teeth with an increased probing depth and tooth mobility and teeth presenting with lesions not located at the apex.

Modeling Framework for the Establishment of the Apical-Basal Embryonic Axis in Plants

The apical-basal axis of the early plant embryo determines the body plan of the adult organism. To establish a polarized embryonic axis, plants evolved a unique mechanism that involves directional, cell-to-cell transport of the growth regulator auxin. Auxin transport relies on PIN auxin transporters 1], whose polar subcellular localization determines the flow directionality. PIN-mediated auxin transport mediates the spatial and temporal activity of the auxin response machinery 2-7] that contributes to embryo patterning processes, including establishment of the apical (shoot) and basal (root) embryo poles 8]. However, little is known of upstream mechanisms guiding the (re)polarization of auxin fluxes during embryogenesis 9]. Here, we developed a model of plant embryogenesis that correctly generates emergent cell polarities and auxin-mediated sequential initiation of apical-basal axis of plant embryo. The model relies on two precisely localized auxin sources and a feedback between auxin and the polar, subcellular PIN transporter localization. Simulations reproduced PIN polarity and auxin distribution, as well as previously unknown polarization events during early embryogenesis. The spectrum of validated model predictions suggests that our model corresponds to a minimal mechanistic framework for initiation and orientation of the apical-basal axis to guide both embryonic and postembryonic plant development.