Effects of implant angulation, material selection, and impression technique on impression accuracy: a preliminary laboratory stu

The aim of this preliminary laboratory study was to evaluate the effects of 5- and 25-degree implant angulations in simulated clinical casts on an impression's accuracy when using different impression materials and tray selections. A convenience sample of each implant angulation group was selected for both open and closed trays in combination with one polyether and two polyvinyl siloxane impression materials. The influence of material and technique appeared to be significant for both 5- and 25-degree angulations (P < .05), and increased angulation tended to decrease impression accuracy. The open-tray technique was more accurate with highly nonaxially oriented implants for the small sample size investigated.     

Failure modes in conservative and surgical management of infectious spondylodiscitis

Purpose and methods

We reviewed the management, failure modes, and outcomes of 196 patients treated for infectious spondylodiscitis between January 1, 2000 and December 31, 2010, at the Spinal Unit, Aarhus University Hospital, Aarhus, Denmark. Patients with infectious spondylodiscitis at the site of previous spinal instrumentation, spinal metastases, and tuberculous and fungal spondylodiscitis were excluded.

Results

Mean age at the time of treatment was 59 (range 1–89) years. The most frequently isolated microorganism was Staphylococcus aureus. The lumbosacral spine was affected in 64 % of patients and the thoracic in 21 %. In 24 % of patients, there were neurologic compromise, four had the cauda equina syndrome and ten patients were paraplegic. Ninety-one patients were managed conservatively. Treatment failed in 12 cases, 7 patients required re-admission, 3 in-hospital deaths occurred, and 5 patients died during follow-up. Posterior debridement with pedicle screw instrumentation was performed in 75, without instrumentation in 19 cases. Seven patients underwent anterior debridement alone, and in 16 cases, anterior debridement was combined with pedicle screw instrumentation, one of which was a two-stage procedure. Re-operation took place in 12 patients during the same hospitalization and in a further 12 during follow-up. Two in-hospital deaths occurred, and five patients died during follow-up. Patients were followed for 1 year after treatment. Eight (9 %) patients treated conservatively had a mild degree of back pain, and one (1 %) patient presented with mild muscular weakness. Among surgically treated patients, 12 (10 %) had only mild neurological impairment, one foot drop, one cauda equine dysfunction, but 4 were paraplegic. Twenty-seven (23 %) complained of varying degrees of back pain.

Conclusions

Conservative measures are safe and effective for carefully selected patients without spondylodiscitic complications. Failure of conservative therapy requires surgery that can guarantee thorough debridement, decompression, restoration of spinal alignment, and correction of instability. Surgeons should master various techniques to achieve adequate debridement, and pedicle screw instrumentation may safely be used if needed.     

Response of Peripheral Blood Th17 Cells to Inhaled Dermatophagoides pteronyssinus in Patients with Allergic Rhinitis and Asthma

Background

Recent studies have shown the importance of Th17 cells in the development of allergic airway diseases. We examined Dermatophagoides pteronyssinus-induced changes in peripheral blood Th17 cells to establish the importance of these cells in late-phase allergic inflammation in patients with allergic rhinitis (AR) and allergic asthma (AA).

Methods

Eighteen patients with mild-to-moderate/severe persistent AR, 14 patients with intermittent- or mild-to-moderate persistent AA, and 15 healthy subjects (HS) were examined. All patients had positive skin test to D. pteronyssinus. Study subjects underwent bronchial challenge with D. pteronyssinus. The peripheral blood Th1, Th2, and Th17 cells were determined by flow cytometry 24?h before and 7 and 24?h after challenge. The serum IL-17 levels were determined by ELISA.

Results

The percentage of Th17 cells and IL-17 levels was significantly higher in patients with AR and AA compared with HS before and after challenge. Twenty-four hours after challenge, the percentage of Th17 cells increased significantly in patients with AA compared with baseline values. The IL-17 levels rose markedly in patients with AR and AA after challenge. Moreover, 24?h after challenge, the percentage of Th17 cells and IL-17 levels were significantly higher in patients with AA than those with AR.

Conclusions

Percentages of peripheral blood Th17 cells and serum IL-17 levels were found to be higher in patients with AR and AA. An increase in the percentage of Th17 cells following challenge shows that Th17 cells may have an important role in the development of late-phase allergen-induced inflammation.     

Comparison of Implant Quality between Loose and Intra-operatively Linked Iodine-125 Seeds in Prostate Cancer Brachytherapy

From 2007 to 2010, 230 patients had iodine-125 seeds implanted (loose or intra-operatively linked into seed trains with variable seed-to-seed spacing). The primary aim was to evaluate differences in implant quality by comparing the intra-operative and post-implant dosimetry in patients treated with loose and intra-operatively linked seeds. The secondary aim was to evaluate the "learning curve" for the procedure. The following parameters were compared: the radiation dose to 90% of the prostate volume (D90), the radiation dose to 30% of the urethral volume (DU30), the percentage of the prostate volume receiving 100% or 200% of the prescribed dose (V100 or V200, respectively), the percentage of the rectal volume receiving 100% of the prescribed dose (VR100), and the homogeneity index (HI). We obtained the following results for loose vs. intra-operatively linked seeds: D90 (Gy), 184.7 ± 15.0 vs. 177.9 ± 12.7 (p = 0.002); V100 (%), 95.5 ± 2.4 vs. 94.9 ± 3.2 (p = 0.206); V200 (%), 35.1 ± 7.5 vs. 24.3 plusmn; 6,9 (p < 0.001); DU30 (Gy), 218.6 ± 24.1 vs. 197.4 ± 19.5 (p = 0.001); VR100 (cm³), 0.6 ± 0.47 vs. 0.3 ± 0.3 (p < 0.001); HI (%), 31.8 ± 7.3 vs. 44.0 ± 9.8 (p < 0.001). The advantages of intra-operatively linked seed implantation over loose seed implantation are a more homogeneous prostate dose and lower urethral and rectal doses. The disadvantage is a lower post-implant D90. Sufficient experience with the loose seed implantation procedure was obtained after the first 40 patients. There was essentially no learning curve when a new implantation method using intra-operatively linked seeds was subsequently initiated.     

Early onset of neural synchronization in the contextual associations network

Objects are more easily recognized in their typical context. However, is contextual information activated early enough to facilitate the perception of individual objects, or is contextual facilitation caused by postperceptual mechanisms? To elucidate this issue, we first need to study the temporal dynamics and neural interactions associated with contextual processing. Studies have shown that the contextual network consists of the parahippocampal, retrosplenial, and medial prefrontal cortices. We used functional MRI, magnetoencephalography, and phase synchrony analyses to compare the neural response to stimuli with strong or weak contextual associations. The context network was activated in functional MRI and preferentially synchronized in magnetoencephalography (MEG) for stimuli with strong contextual associations. Phase synchrony increased early (150–250 ms) only when it involved the parahippocampal cortex, whereas retrosplenial–medial prefrontal cortices synchrony was enhanced later (300–400 ms). These results describe the neural dynamics of context processing and suggest that context is activated early during object perception.     

Gastrectomy impact on the gut microbiome in patients with gastric cancer: A comprehensive review

Gastric cancer is one of the most common malignancies worldwide and gastrectomy remains the only potentially curative treatment option for this disease. However, the surgery leads to significant physiological and anatomical changes in the gastrointestinal (GI) tract including loss of the gastric barrier, an increase in oxygenation levels in the distal gut, and biliary diversion after gastrectomy. These changes in the GI tract influence the composition of the gut microbiome and thus, host health. Gastrectomy-induced dysbiosis is characterized by increased abundance of typical oral cavity bacteria, an increase in aero-tolerant bacteria (aerobes/facultative anaerobes), and increased abundance of bile acid-transforming bacteria. Furthermore, this dysbiosis is linked to intestinal inflammation, small intestinal bacterial overgrowth, various GI symptoms, and an increased risk of colorectal cancer.     

Genetic ablation of tenascin‐C expression leads to abnormal hippocampal CA1 structure and electrical activity in vivo

Despite evidence that the extracellular matrix glycoprotein tenascin‐C (TNC) is implicated in brain development and plasticity, its roles in the intact adult brain are unknown. Here we report that spontaneous local field potential (LFP) activity in freely moving adult TNC‐deficient mice is abnormal. The power of cortical and hippocampal theta and gamma oscillations was enhanced in comparison to wild‐type mice. The alteration in hippocampal gamma rhythm was subfield specific, such that CA1 gamma was accentuated while dentate gyrus gamma was normal. Similar to LFP, synaptic transmission and plasticity at perforant path synapses in the dentate gyrus were unaffected by the mutation. Morphological analyses revealed a subfield‐specific reduction in the CA1 volume and a reduction in the numbers of somatostatin‐positive interneurons in the hippocampus as potential structural substrates of the observed functional aberrations. These findings indicate a role for tenascin‐C in structural organization of the CA1 hippocampal subfield and in shaping neural activity. © 2009 Wiley‐Liss, Inc.     

Sex‐related differences in behavioral and amygdalar responses to compound facial threat cues

During face perception, we integrate facial expression and eye gaze to take advantage of their shared signals. For example, fear with averted gaze provides a congruent avoidance cue, signaling both threat presence and its location, whereas fear with direct gaze sends an incongruent cue, leaving threat location ambiguous. It has been proposed that the processing of different combinations of threat cues is mediated by dual processing routes: reflexive processing via magnocellular (M) pathway and reflective processing via parvocellular (P) pathway. Because growing evidence has identified a variety of sex differences in emotional perception, here we also investigated how M and P processing of fear and eye gaze might be modulated by observer's sex, focusing on the amygdala, a structure important to threat perception and affective appraisal. We adjusted luminance and color of face stimuli to selectively engage M or P processing and asked observers to identify emotion of the face. Female observers showed more accurate behavioral responses to faces with averted gaze and greater left amygdala reactivity both to fearful and neutral faces. Conversely, males showed greater right amygdala activation only for M‐biased averted‐gaze fear faces. In addition to functional reactivity differences, females had proportionately greater bilateral amygdala volumes, which positively correlated with behavioral accuracy for M‐biased fear. Conversely, in males only the right amygdala volume was positively correlated with accuracy for M‐biased fear faces. Our findings suggest that M and P processing of facial threat cues is modulated by functional and structural differences in the amygdalae associated with observer's sex.     

Transanal endoscopic microsurgery for giant benign rectal tumours: is large size a contraindication?

Purpose

The purpose of this study is to look at our early postoperative results, recurrence rates and need for further radical surgery in treating large (> 5 cm) rectal tumours by transanal endoscopic microsurgery (TEM).

Methods

Patients who underwent TEM for rectal tumours greater than 5 cm were included. Tumour diameter was determined based on fresh specimen measurements. We recorded the demographics, operative details, final pathology, length of hospital stay, complications and recurrence rates.

Results

Mean tumour size was 5.9 ± 1.5 cm. 68.4% of tumours (13/19) were in the middle part of the rectum. Three patients (15.8%) developed postoperative complications: two had postoperative bleeding (10.5%), one had wound dehiscence (5.3%). Three patients had involved margins (15.8%). After a median follow up of 25.2 months, there were two recurrences (10.5%). One patient developed rectal cancer 6 years after removal of rectal adenoma.

Conclusion

TEM is feasible and safe for the treatment of giant benign rectal tumours. It may be an alternative method for proctectomy in selected patients.