Displacement of Dental Implants in Trabecular Bone under a Static Lateral Load in Fresh Bovine Bone

Aim: The study aims to provide objective data for the displacement of titanium screw implants in trabecular bone specimens. One hundred Semados implants (Bego, Bremen, Germany) were inserted in bovine type IV bone specimens. All implants had a diameter of 3.75 mm; 50 implants had a length of 8.5 mm and 50 implants had a length of 15 mm. Insertion torque was determined at intervals of 10, 20, and 30 Ncm. Implants were loaded horizontally with 10, 20, and 30 N for 2 seconds. An indicator strip was attached to the implant abutment to allow direct observation of implant movement relative to the bone surface. Horizontal displacement was assessed with an accuracy of measurement of 10 µm. Seven implants got lost by visible loosening. Degree of displacement was subject to evaluation with all others. Those implants showed a mean displacement of 59 µm for 10 N (n = 100), 173 µm for 20 N (n = 99), and 211 µm for 30 N (n = 93). The mean displacement of 15‐mm implants (16, 37, 51 µm) was significantly lower compared with 8.5‐mm implants (103, 311, 396 µm) corresponding to 10, 20, and 30 N as lateral loads. Conclusions: Displacement of screw implants in trabecular bone can be detected and visualized using commercially available endoscopes with a high magnification. A lateral load of 20 N indicates a mean displacement of over 100 µm and therefore results in a critical displacement.     

Initial Results after Implementation of a Multimodal Treatment for Peritoneal Malignancies

Introduction : Peritoneal carcinomatosis represents a clinical condition with a limited perspective concerning long term survival. The combination of surgical cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) represents a complex multimodal therapeutic management concept with promising results for prolongation of survival. For the identification of pitfalls during implementation of the HIPEC procedure into clinical practice an observational study was conducted.

Methods : Between 2005 and 2009 data from all patients treated with cytoreductive surgery and HIPEC for peritoneal carcinomatosis was prospectively collected and analysed.

Results : During the observational interval a total of 42 patients underwent surgical treatment for peritoneal carcinomatosis. In 34 patients the complete procedure with surgical cytoreduction and HIPEC was performed. Perioperative mortality (6%) and morbidity (35%) was similar to other reported series. Twenty-five patients (76%) survived the 18 months follow-up period after complete procedure.

Conclusion : The multimodal therapeutic treatment concept of surgical cytoreduction and following HIPEC leads to promising results for patients suffering from peritoneal carcinomatosis. However this treatment concept is afflicted with a relevant risk of postoperative complications.     

Preparing for Prospective Clinical Trials: A National Initiative of an Excellence Registry for Consecutive Pancreatic Cancer Resections

Background

Despite significant improvements in perioperative mortality as well as response rates to multimodality treatment, results after surgical resection of pancreatic adenocarcinoma with respect to long-term outcomes remain disappointing. Patient recruitment for prospective international trials on adjuvant and neoadjuvant regimens is challenging for various reasons. We set out to assess the preconditions and potential to perform perioperative trials for pancreatic cancer within a well-established Austrian nationwide network of surgical and medical oncologists (Austrian Breast & Colorectal Cancer Study Group).

Methods

From 2005 to 2010 five high-volume centers and one medium-volume center completed standardized data entry forms with 33 parameters (history and patient related data, preoperative clinical staging and work-up, surgical details and intraoperative findings, postoperative complications, reinterventions, reoperations, 30-day mortality, histology, and timing of multimodality treatment). Outside of the study group, in Austria pancreatic resections are performed in three “high-volume” centers (>10 pancreatic resections per year), three “medium-volume” centers (5–10 pancreatic resections per year), and the rest in various low-volume centers (<5 pancreatic resections per year) in Austria. Nationwide data for prevalence of and surgical resections for pancreatic adenocarcinoma were contributed by the National Cancer Registry of Statistics of Austria and the Austrian Health Institute.

Results

In total, 492 consecutive patients underwent pancreatic resection for ductal adenocarcinoma. All postoperative complications leading to hospital readmission were treated at the primary surgical department and documented in the database. Overall morbidity and pancreatic fistula rate were 45.5 % and 10.1 %, respectively. Within the entire cohort there were 9.8 % radiological reinterventions and 10.4 % reoperations. Length of stay was 16 days in median (0–209); 12 of 492 patients died within 30 days after operation, resulting in a 30-day mortality rate of 2.4 %. Seven of the total 19 deaths (36.8 %) occurred after 30 days, during hospitalization at the surgical department, resulting in a hospital mortality rate of 3.9 % (19/492). With a standardized histopathological protocol, there were 70 % (21/30) R0 resections, 30 % (9/30) R1 resections, and no R2 resections in Vienna and 62.7 % (32/51) R0 resections, 35.3 % (18/51) R1 resections, and 2 % (1/51) R2 resections in Salzburg. Resection margin status with nonstandardized protocols was classified as R0 in 82 % (339/411), R1 in 16 % (16/411), and R2 in 1.2 % (5/411). Perioperative chemotherapy was administered in 81.1 % of patients (8.3 % neoadjuvant; 68.5 % adjuvant; 4.3 % palliative); chemoradiotherapy (1.6 % neoadjuvant; 3 % adjuvant; 0.2 % palliative), in 4.9 % of patients. The six centers that contributed to this registry initiative provided surgical treatment to 40 % of all Austrian patients, resulting in a median annual recruitment of 85 (51–104) patients for the entire ABCSG-group and a median of 11.8 (0–38) surgeries for each individual department.

Conclusions

Surgical quality data of the ABCSG core pancreatic group are in line with international standards. With continuing centralization the essential potential to perform prospective clinical trials for pancreatic adenocarcinoma is given in Austria. Several protocol proposals aiming at surgical and multimodality research questions are currently being discussed.     

Using discrete-event simulation in strategic capacity planning for an outpatient physical therapy service

This study uses a simulation model as a tool for strategic capacity planning for an outpatient physical therapy clinic in Taipei, Taiwan. The clinic provides a wide range of physical treatments, with 6 full-time therapists in each session. We constructed a discrete-event simulation model to study the dynamics of patient mixes with realistic treatment plans, and to estimate the practical capacity of the physical therapy room. The changes in time-related and space-related performance measurements were used to evaluate the impact of various strategies on the capacity of the clinic. The simulation results confirmed that the clinic is extremely patient-oriented, with a bottleneck occurring at the traction units for Intermittent Pelvic Traction (IPT), with usage at 58.9 %. Sensitivity analysis showed that attending to more patients would significantly increase the number of patients staying for overtime sessions. We found that pooling the therapists produced beneficial results. The average waiting time per patient could be reduced by 45 % when we pooled 2 therapists. We found that treating up to 12 new patients per session had no significantly negative impact on returning patients. Moreover, we found that the average waiting time for new patients decreased if they were given priority over returning patients when called by the therapists.     

Circulating procalcitonin and cleavage products in septicaemia compared with medullary thyroid carcinoma

OBJECTIVE: Raised plasma levels of procalcitonin (proCT) represent an early marker for septicaemia. They are related to disease severity and inversely to outcome and response to treatment. ProCT is presumably synthesised in tIssues other than the thyroid C-cells which are the source of calcitonin (CT) in normal physiology. This study compares proCT and its cleavage products in the serum of patients with septicaemia with those in medullary thyroid carcinoma (MTC). METHODS: Immunoreactive proCT and its cleavage products were extracted from the serum of patients with septicaemia or MTC using octadecylsilyl silica columns and characterised by reversed phase HPLC and Western blot analysis. ProCT, CT(1-32) and the flanking peptides PAS-57 and PDN-21 were recognised with antibodies specific for the individual peptides. RESULTS: ProCT and a 10 kDa polypeptide were recognised with antibodies to PAS-57, CT(1-32) and PDN-21. An 8 kDa proCT fragment was detected with antibodies to CT and PDN-21. However, intact CT(1-32), PAS-57 and PDN-21, found in the serum of MTC patients, were undetectable. The results indicate partial cleavage of proCT in septicaemia different from that in MTC patients. CONCLUSIONS: ProCT and 10 and 8 kDa proCT fragments were recognised in the circulation of septic patients. They were different from the known proCT-processing products PAS-57, CT(1-32) and PDN-21 identified in the serum of normal subjects and of MTC patients. Distinct cleavage of proCT may contribute to the symptoms of septicaemia.     

Heparin facilities proliferation of human osteoblasts in vitro

It is a well-known fact that long-term application of heparin can lead to osteoporosis. To learn more about the mechanisms of heparin-induced osteoporosis, we exposed human osteoblasts in vitro to heparin in various concentrations. We found an increased proliferation rate, especially in concentrations used therapeutically in humans (0.1-0.2 IU/ml). In our experiments fetal calf serum (FCS) was able to heighten the positive effect of heparin, showing a synergism between heparin and FCS.     

Effect of the CYP2D6 genotype on metoprolol metabolism persists during long-term treatment

The beta1 selective beta-blocker metoprolol is metabolized predominantly but not exclusively by CYP2D6. Due to the polymorphism of the CYP2D6 gene, CYP2D6 activity varies markedly between individuals. Consequently, after short-term administration metoprolol plasma concentrations were found to be several fold higher in poor metabolizers than in extensive metabolizers. However, it is currently not known, whether the impact of the CYP2D6 polymorphism persists during long-term therapy, since alternate mechanisms of elimination or metabolism could be effective in this setting. The study comprised 91 Caucasian patients on long-term treatment with metoprolol (median duration of treatment 12.6 months; median daily drug dose: 47.5 mg/day). Metoprolol and alpha-OH-metoprolol plasma concentrations were assessed by HPLC. Genotyping detected the null alleles (*0): *3, *4, *5, *6, *7, *8, *12, *14, *15, the alleles *9, *10 and *41 associated with reduced enzymatic activity as well as the fully functional alleles *1 and *2. Genotype and allele frequencies were in accordance with published frequencies for the German population. The plasma metabolic ratio of metoprolol/alpha-OH-metoprolol was markedly affected by the genotype (P < 0.0001). In accordance, median adjusted metoprolol plasma concentrations were 6.2- and 3.9-fold higher in patients with *0/*0 genotypes (n = 8) and intermediate genotypes (n = 10), respectively, as compared to those with two fully functional alleles (n = 31; P < 0.01). In summary, the pronounced effect of the CYP2D6 genotype persists during long-term therapy, affecting both metabolic ratio and metoprolol plasma concentration.