Three-dimensional computerized stress analysis of commercially pure titanium and yttrium-partially stabilized zirconia implants

PURPOSE: The purpose of this study was to use three-dimensional finite element analysis to analyze stress distribution patterns in Re-Implant implants made of commercially pure titanium (cpTi) and yttrium-partially stabilized zirconia (YPSZ). MATERIALS AND METHODS: Two three-dimensional finite element analysis models of a maxillary incisor with Re-Implant implants were made, surrounded by cortical and cancellous bone. A porcelain-fused-to-metal crown for the cpTi implant and a ceramic crown for the YPSZ implant were modeled. Stress levels were calculated according to the von Mises criteria. RESULTS: Higher stresses were observed at the area where the implant entered the bone. Stresses were higher at the facial and lingual surfaces than the proximal ones. In cortical bone and at the junction of cortical and cancellous bone, stress distribution presented a pattern of alternating higher (4.0 to 5.0 MPa) and lower (1.3 to 2.0 MPa) stress areas. Higher stresses were found at the apical third of the implant-to-bone junction as well. CONCLUSION: Re-Implant implants presented a pattern of low, well-distributed stresses along the entire implant-to-bone interface. YPSZ implants had very similar stress distribution to cpTi implants and may be viable esthetic alternatives, especially in maxillary anterior regions.     

An EU-wide approach to HTA: An irrelevant development or an opportunity not to be missed?

An EU-wide cooperation on HTA has been proposed recently by the European Commission, focusing on relative effectiveness assessment (REA) for pharmaceuticals and medical devices. This cooperation is operationalised through a proposal for a regulation. While a good step in the right direction, this HTA cooperation framework needs to be more explicit and pragmatic about clinical value definition, what constitutes quality of evidence, how real-world evidence is handled, whether the same assessment requirements will apply for medical devices as they do for pharmaceuticals, and how to safeguard consistency in REA interpretation. If demand-rather than supply-driven, this initiative can deliver wider benefits: Europe can improve its power in global drug design and development, while Member States will have at their disposal more resources to assess performance of interventions in their healthcare systems.

     

Pharmacogenetics of immunosuppressant drugs: A new aspect for individualized therapy

In recent years, pharmacogenetics has emerged as an important tool for choosing the right immunosuppressant drug and its appropriate dose. Indeed, pharmacogenetics may exert its action on immunosuppressant drugs at three levels. Pharmacogenetics identifies and studies the genes involved in encoding the proteins involved in drug pharmacokinetics and in encoding the enzymes involved in drug degradation. Pharmacogenetics is also relevant in encoding the enzymes and proteins involved in codifying the transmembrane proteins involved in transmembrane passage favoring the absorption and intracellular action of several immunosuppressants. Pharmacogenetics concern the variability of genes encoding the proteins involved as immunosuppressant triggers in the pharmacodynamic pathways. Of course, not all genes have been discovered and studied, but some of them have been clearly examined and their relevance together with other factors such as age and race has been defined. Other genes on the basis of relevant studies have been proposed as good candidates for future studies. Unfortunately, to date, clear conclusions may be drawn only for those drugs that are metabolized by CYP3A5 and its genotyping before kidney, heart and lung transplantation is recommended. The conclusions of the studies on the recommended candidate genes, together with the development of omics techniques could in the future allow us to choose the right dose of the right immunosuppressant for the right patient.     

Adenovirus genome in the placenta: association with histological chorioamnionitis and preterm birth

Adenovirus is isolated frequently from the amniotic fluid and has been implicated in severe neonatal infections. A case control study was carried out to examine the association of detection of adenovirus in placentas with preterm birth and histological chorioamnionitis. Placentas from preterm and full term deliveries were collected prospectively. Preterm cases were divided into three subgroups according to the gestational age. PCR was carried out on placental tissues for the detection of adenovirus genome. Placentas were evaluated histologically for the presence of chorioamnionitis. Chi‐square and odds ratios (OR) were used to determine if detection of adenovirus is associated with preterm birth and histological evidence of inflammation. Seventy‐one preterm and 122 full term placentas were studied. Adenovirus genome was detected in 29 (40.8%) of preterm cases and in 25 (20.5%) of the full term controls (OR = 2.6; 95% CI, 1.4–5.1; P = 0.002). Detection of adenovirus in preterm placentas was significantly higher compared to full term particularly in the lower gestational age. Detection of adenovirus in placenta followed the seasonal variation of adenovirus infections. Thirty‐seven preterm and 21 full term placentas were also selected for paraffin inclusion and histological examination. Chorioamnionitis was present more frequently in preterm adenovirus‐positive placentas compared to preterm adenovirus‐negative placentas (75% vs. 36%; P = 0.026) as well as compared to term adenovirus‐positive placentas (75% vs. 19%; P = 0.003). This study demonstrates that adenovirus infection of the placenta is associated strongly with histological chorioamnionitis and preterm birth. J. Med. Virol. 82:1379–1383, 2010. © 2010 Wiley‐Liss, Inc.     

Impact of placenta previa on obstetric outcome

Objective

To determine the maternal and perinatal outcome for different types of placenta previa (PP).

Methods

A retrospective review of 132 singleton pregnancies with PP. Outcome measures, including the incidence of obstetric hysterectomy, the neonatal Apgar score, and the neonatal weight, were evaluated by logistic regression analysis.

Results

The incidence of PP was 1.0%. Of the women with PP, 51.5% had complete PP, 20.5% had incomplete PP, 5.3% had marginal PP, and 22.7% had a low-lying placenta. Most (93.9%) women were delivered by cesarean delivery. In total, 19.7% women underwent obstetric hysterectomy; of these, 92.3% had complete PP. Mothers with 2 or more previous cesarean deliveries had an increased risk for obstetric hysterectomy (P < 0.01). The gestational age at delivery was a significant linear predictor of the 5-minute Apgar score. Mothers with incomplete PP delivered neonates with lower Apgar scores than did mothers with complete PP.

Conclusion

A history of multiple cesarean deliveries increased the risk for obstetric hysterectomy in women with PP. The type of PP had no effect on maternal and neonatal outcome, with exception of the fact that neonates in the incomplete PP group had lower Apgar scores than neonates in the complete PP group.     

Concurrent pleural infiltration by chronic lymphocytic leukemia and adenocarcinoma of unknown primary site diagnosed by effusion cytology

Synchronous malignancies in a pleural effusion are rare. A case of concurrent pleural infiltration by adenocarcinoma of unknown primary site and chronic lymphocytic leukemia (CLL) is presented in this case study, which was diagnosed by effusion cytology. Pleural effusion is not an uncommon complication in patients with B‐CLL. Even in a pleural effusion rich in monoclonal lymphocytes, the presence of a second cancer must be excluded because this can be the main cause of mortality. The role of cytology in such cases is of paramount importance. Diagn. Cytopathol. 2014;42:151–155. © 2012 Wiley Periodicals, Inc.     

Autologous Fat Transplantation and Delayed Silicone Implant Insertion in a Case of Mycobacterium avium Breast Infection

Background  

Infection after breast augmentation is uncommon, occurring in 1–3% of cases. They are typically caused by bacterial skin flora, specifically Staphylococcus aureus and the coagulase-negative staphylococci. There have been infrequent reports of breast implant infection caused by the atypical mycobacteria.     

Maternal uterine artery Doppler flow velocimetry and the risk of stillbirth

OBJECTIVE: We sought to relate the risk of antepartum stillbirth to uterine artery Doppler flow velocimetry at 22-24 weeks. METHODS: Data were available from 30,519 unselected women from seven units in the UK who had uterine artery Doppler performed between 22 and 24 weeks of gestation. The risk of stillbirth (n=109) was assessed using time to event and logistic regression analysis. Stillbirths were subdivided into placental (due to abruption, preeclampsia, or growth restriction) or unexplained. RESULTS: The risk of placental stillbirth was increased among women with a mean pulsatility index in the top decile (adjusted hazard ratio [HR] 5.5, 95% confidence interval [CI] 2.8-10.6) and those with a bilateral notch (adjusted HR 3.9, 95% CI 2.0-7.8). The relationship between a mean pulsatility index in the top decile and the risk of unexplained stillbirth was weaker (adjusted HR 2.5, 95% CI 1.1-5.6) and there was no association with a bilateral notch. Placental stillbirths occurred at earlier gestations than unexplained stillbirths (median [interquartile range] 30 [26-36] compared with 38 [36-40], P<.001). Consequently, being in the top 5% of predicted risk of stillbirth on the basis of the combination of mean pulsatility index and notching was a good predictor (sensitivity, specificity, and positive likelihood ratio) of all cause stillbirth up to 32 weeks (58%, 95%, and 12.1, respectively) but a poor predictor of stillbirth at later gestations (7%, 95%, and 1.3, respectively). CONCLUSION: Abnormal uterine artery Doppler was a better predictor of the risk of stillbirth due to placental causes than unexplained stillbirth. Consequently, abnormal uterine artery Doppler was a good predictor of stillbirth at extreme preterm gestations but a poor predictor of stillbirth at term. LEVEL OF EVIDENCE: II.     

Laparoscopy in the evaluation of women with unexplained ascites: an invaluable diagnostic tool

STUDY OBJECTIVE: To assess whether laparoscopy is a reliable technique for the investigation of women presenting with ascites and in whom the diagnosis remains obscure. DESIGN: Prospective nonrandomized clinical study (Canadian Task Force classification II-2). SETTING: University Departments of a tertiary referral center. PATIENTS: Women presenting in our institution with ascites in whom the diagnosis remained obscure after an extensive nonoperative diagnostic work-up. INTERVENTION: Undiagnosed cases were submitted to laparoscopy, and selective biopsy specimens were taken for histologic study. MEASUREMENTS AND MAIN RESULTS: Over a 3-year period, 73 patients were admitted to our institution with diffuse ascites. In 9 patients (12.3%), the diagnosis remained obscure, and these patients were further investigated with laparoscopy. Selective biopsy specimens obtained at laparoscopy clarified the specific cause of the ascites in all 9 patients. Peritoneal carcinomatosis was responsible in 5 patients (a metastatic gastrointestinal tumor in 1 patient, a malignant mesothelioma of the peritoneum in 1 patient, and a serous papillary carcinoma of the peritoneum and of the ovary in 2 and 1 patients, respectively). Three patients were found with miliary peritoneal tuberculosis, and the last patient had an unusual peritoneal reaction to methylene blue after laparoscopic adhesiolysis. CONCLUSION: Laparoscopy is a valuable means of assessing the peritoneal cavity in patients with unexplained ascites, where the primary cause remains unclear. The diagnosis can be accurately made with selective biopsy specimens, and appropriate treatment can be instituted without delay.