[The image of general practitioners compared to that of dentists in the Netherlands]. / Imago van huisartsen versus tandartsen in Nederland.

The image of the professions of family doctor and dentist in the Netherlands was investigated by means of a questionnaire distributed online and in four cities. In total, 270 questionnaires were analysed. The dentist was seen more as a businessman, a solo performer for whom the interests of the patient were less highly prioritised, who,was less communicative, more associated with pain, more distant, less open to dialogue and could be trusted less than the general practitioner. Respondents also felt less safe at the dentist's office than at the general practitioner's. On average, respondents rated the general practitioner significantly higher than the dentist. Dentists scored significantly lower than general practitioners on eleven of the twelve statements. The score of the profession dentist was not significantly different from that of general practitioner in only one category, professionalism. These results indicate that the image of the dental profession is worse than that of the general practitioner.

In Vivo Evaluation of Customized Aortic Repair Using a Novel Survival Model.

OBJECTIVE: The aim of the study was to evaluate the feasibility and mid-term biological behavior of the novel customized aortic repair (CAR) method for endovascular aneurysm treatment. METHODS: CAR consists of exclusion of an aneurysm from the circulation using a custom-designed dog bone-shaped balloon, followed by aneurysm sac filling with an in situ curing polymer. After curing and balloon deflation, the circulation is restored through a patent cast neolumen. A liquid two-component polymer was injected via a small bore catheter under X-ray control into a surgically created aneurysm. In 50% of the procedures, a self expanding bare metal stent was placed in the polymer cast lumen. A novel animal model was established involving creation of an aneurysm by anastomosing a venous interposition graft into the common carotid artery of eight adult sheep. Two animals were excluded because of non-device related complications. The remaining six animals were monitored for 20 weeks with duplex sonograms performed monthly to assess blood flow and polymer cast lumen patency. After the animals were sacrificed the polymer cast, common carotid artery, and the brain in the carotid outflow tract were removed for histological assessment. RESULTS: In four of the six animals, the aneurysm was successfully excluded using CAR with uneventful follow up. The aneurysm sac was filled incompletely in two animals, resulting in a stent malpositioning and cast lumen occlusion after 12 weeks in one case, and a type 1 endoleak in the other. All six animals survived for 20 weeks. Neither migration nor expansion of the polymer cast was observed and the polymer was demonstrated to be biocompatible and non-thrombogenic. Polymer emboli were not detected in the brain or meninges after sacrifice. CONCLUSIONS: The feasibility and mid-term biological safety of the CAR method for minimally invasive aneurysm repair was demonstrated using a simulated aneurysm survival model.

Aortic Customize: an in vivo feasibility study of a percutaneous technique for the repair of aortic aneurysms using injectable elastomer.

OBJECTIVE: This study aimed to test a percutaneous technique for aneurysm-sac filling by means of in situ polymerisation in an in vivo model. DESIGN: Aortic Customize is a new endovascular treatment concept for aortic aneurysms: a non-cross-linked liquid elastomer is injected to fill the aneurysm sac around a balloon-catheter. With this method, a compliant elastomer mould with a patent lumen is created. MATERIAL: The formulation used in the experiments consisted of a two-component addition-cure liquid-silicone formulation, based on vinyl-terminated polydimethylsiloxane (PDMS). METHODS: The concept of aneurysm-sac filling was tested in vivo in porcine experiments (n = 3). RESULTS: In vivo porcine experiments with the sac-filling application showed successful exclusion of the created aneurysms with patent lumens and absence of endoleaks. The aneurysms were excluded successfully in the in vivo model, injecting elastomer through a 7-French catheter, filling up the entire aneurysm sac. CONCLUSIONS: These in vivo experiments demonstrate that the principle of aneurysm-sac filling by means of in situ curing is feasible, excluding the aneurysm and creating a new lumen. Further long-term animal experiments must be done prior to consideration of clinical application.

The safety and efficacy of a paclitaxel-eluting wrap for preventing peripheral bypass graft stenosis: a 2-year controlled randomized prospective clinical study.

OBJECTIVES: To compare the safety and efficacy of a bioresorbable paclitaxel-eluting wrap implanted with a synthetic vascular graft (treatment) versus the graft implanted alone (control). DESIGN: Prospective, randomized, controlled, multicentre, 2-year clinical study conducted in adults scheduled to undergo femoropopliteal peripheral bypass surgery with a polytetrafluoroethylene (PTFE) graft. MATERIALS AND METHODS: Hundred and nine subjects were randomized 2:1 to treatment or control. All subjects were implanted with a 6mm expanded PTFE vascular graft; in addition, treated subjects had a 2.5 cm x 4 cm paclitaxel-eluting wrap (1.6 microg/mm(2)) placed around the distal graft anastomosis. RESULTS: The overall incidence of adverse events was similar in both groups. Treated subjects required fewer limb amputations than controls (15.5% vs 18.4%) and time to amputation for those that required amputation was twice as long (153 days vs 76 days). Among diabetics, this effect was pronounced with 13.8% of treated subjects requiring limb amputations compared with 23.5% of controls. Over the course of study, the diameter at the distal graft anastomosis was greater in treated subjects than in controls (difference of 2.1mm at 2 yr, p=0.03). CONCLUSIONS: The paclitaxel-eluting wrap maintained graft patency at the distal anastomosis and was safe to use in patients who had received a peripheral bypass PTFE graft.

A hereditary immunoglobulin A abnormality: absence of light-heavy-chain assembly. Study of immunoglobulin synthesis in tonsillar cells.

A new immunoglobulin A abnormality, absence of assembly of alpha-chain and light-chain, was found in an adult female suffering from recurrent upper respiratory infection and tonsillitis since childhood, but otherwise healthy. The IgA abnormality was manifest in her serum by the presence of free alpha-chains, in her saliva by the presence of alpha-chains bound to secretory piece, and in her urine by the presence of free alpha-chains and free light-chains. The serum IgG and IgM were found to be complete, containing both heavy-chains and light-chains. Evidence for this immunoglobulin A abnormality was also found in the proposita's mother and elder son, demonstrating it to be a hereditary disorder. Studies performed with patient's tonsillar cells in short-term culture, using amino acids-(14)C, revealed synthesis and secretion of both free alpha-chains and free light-chains, in addition to synthesis and secretion of normally assembled IgG and IgM.

Effects of detergents and choline-containing phospholipids on human spleen glucocerebrosidase.

1. Glucocerebrosidase, extracted from human spleen lysosomal membrane by sodium cholate and recovered in a high speed centrifugation supernatant, aggregated following removal of the detergent. 2. Re-solubilization of the enzymatic activity from the aggregate was achieved by treatment with the non-ionic detergents Triton X-100 and Tween 20. The anionic detergents sodium cholate and sodium taurocholate and the cationic detergents cetyltrimethylammonium bromide and cetylpyridinium chloride were also effective. The solubilizing capacity of the anionic detergents was smaller than that of the nonionic detergents. Quantitative evaluation of the solubilizing capacity of the cationic detergents was not feasible because of their being potent inhibitors of glucocerebrosidase activity. 3. Treatment of the enzyme aggregate with acetone rendered it buffer-soluble. 4. In addition to the above cationic detergents some choline-containing and highly hydrophobic phospholipids were found to inhibit the glucocerebrosidase activity.

Local application of granulocyte-macrophage colony stimulating factor (GM-CSF) for the treatment of oral mucositis.

The combination of radiation and chemotherapy administered for patients undergoing therapy for advanced head and neck neoplasms leads to a significant rise in toxic side-effects. Oral mucositis remains one of the most distressing factors leading to pain, impairment of oral nutrition, local and systemic infection and often cessation of the oncological treatment. The local and systemic administration of recombinant growth factors has revealed a potential benefit in the treatment of oral mucositis. Clinical data concerning the topical use of granulocyte-macrophage colony-stimulating-factor (GM-CSF) in the prevention and therapy of mucositis in patients undergoing radiochemotherapy for advanced cancer of the head and neck are presented in this paper. A prospective, randomised, open parallel-grouped, single centre study at a university hospital was performed. 35 patients with stage III and IV carcinomas of the head and neck were included. Statistical analysis concerning the degree of oral mucositis, the perception of pain, the incidence of secondary infections and the change in haematological parameters revealed no superiority of GM-CSF in comparison to conventional mouthwash between the two groups of patients. As a result, and faced with the tremendous costs of the regular use of a recombinant cytokine, we ended the clinical trial after 35 patients. The topical administration of GM-CSF to treat oral mucositis as a result of radiochemotherapy in patients suffering from head and neck cancer cannot be recommended.

Cyclic loading of fractured cadaveric femurs after elastomer femoroplasty: an in vitro biomechanical study.

BACKGROUND: Elastomer femoroplasty is a novel and experimental approach in the prevention of hip fracture surgery. Previously, we published the results of an in vitro cadaveric experiment in which we showed a significant reduction of fracture displacement in treated femurs. The aim of the present study was to establish the failure loads and inter-fragmentary movement of fractured, elastomer femoroplasty treated femurs during cyclic loading. METHODS: 16 cadaveric femurs were treated with elastomer femoroplasty and fractured in a simulated fall configuration. Each specimen underwent 10 cycles with a preload of 50 N, starting with a peak load of 250 N followed by 10 cycles of 500 N and continued with 500 N increments. The crosshead speed was 2 mm/s. The failure load, the number of completed cycles, and crosshead extensions were recorded. FINDINGS: The mean failure load was 2709 N (SD 1094). The number of completed cycles until failure was 60 (SD 22). The mean translation during maximum loading was 5.25 mm (SD 0.9). At 1500 N (two times the bodyweight of a 75 kg individual) the extension was 3.16 mm. INTERPRETATION: Preventive elastomer femoroplasty leads to the stabilization of the proximal femur after fracture. In a single leg stance configuration, cyclic loading with mean failure loads that well exceed the peak loads during normal gait is feasible.

Elastomer femoroplasty prevents hip fracture displacement In vitro biomechanical study comparing two minimal invasive femoroplasty techniques.

UNLABELLED: The purpose of this study was to test femur strength and the ability to prevent fracture displacement of two minimal invasive Elastomer femoroplasty techniques. METHODS: A total of sixteen fixed human cadaveric femur pairs were used. From each pair one femur was randomly assigned for Elastomer femoroplasty. In these femora we drilled a 3.5mm entrance in the lateral cortex. Cavities for the Elastomer were created by: group A, balloon and group B an excentric drill. All femora were fractured by simulating a fall on the greater trochanter. Neck-shaft-angles on plain anterior posterior radiographs were measured to determine fracture displacement. FINDINGS: There was no significant difference in fracture load between controls and treated femora for group A, 2904N (SD 1091) versus 2803N (SD 627) and group B, 2773N (SD 747) versus 2597N (SD 834). In group A the mean displacement was 35° (SD 14) for the control femora and 3° (SD 2) for the treated femora (P<0.001). In group B the mean displacement was 38° (SD 10) for the controls and 8° (SD 13) for the treated femora (P<0.001). INTERPRETATION: The results of this study show that minimal invasive Elastomer femoroplasty prevents fracture displacement of the proximal femur. We found no significant compromise in load-to-fracture after minimal invasive balloon or excentric drill femoroplasty.

Augmentation with silicone stabilizes proximal femur fractures: an in vitro biomechanical study.

BACKGROUND: Prevention of hip fracture surgery in the elderly imposes great benefit for patient care as well as for society. The incidence of contra-lateral, second hip fractures after hip fracture surgery is as high as 20%. Augmentation of the contra-lateral proximal femur with silicone femoroplasty during hip fracture surgery of the ipsilateral hip could be a new preventive strategy. This study compared the degree of dislocation after a controlled induced fracture between treated and control cadaver femora. METHODS: Ten paired cadaver femora were randomly assigned for silicone femoroplasty and biomechanically tested for fracture load and dislocation against their native contra-lateral control. A load testing machine was used for fracture induction. All femurs were first fractured in a simulated fall configuration followed by dislocation in a "single leg stance" configuration. Dislocation was accessed using the AO-classification and measuring the Caput-Collum-Diaphysis angle. FINDINGS: Fracture loads were approximately 10% lower in the treated group (P=0.304). Forces needed to dislocate the proximal femur fractures did not significantly differ in both groups nor did the fracture type and AO-classification. All treated femurs showed complete reposition according to Caput-Collum-Diaphysis angle after dislocation versus only two of the controls (P<0.001). INTERPRETATION: From the results of this study we conclude silicone femoroplasty stabilizes the proximal femur by restoring hip geometry according to the Caput-Collum-Diaphysis angle after fracture. Future improvements in minimal invasive excavation and injection could make silicone femoroplasty an attractive alternative strategy in the prevention of hip fracture surgery in the growing population of low-demand, elderly patients.

The two major envelope proteins of equine arteritis virus associate into disulfide-linked heterodimers.

In a coimmunoprecipitation assay with monospecific antisera, the two major envelope proteins GL and M of equine arteritis virus were found to occur in heteromeric complexes in virions and infected cells. While the GL protein associated with M rapidly and efficiently, newly synthesized M protein was incorporated into complexes at a slower rate, which implies that it interacts with GL molecules synthesized earlier. Analysis under nonreducing conditions revealed that the GL/M complexes consist of disulfide-linked heterodimeric structures. Pulse-chase experiments showed that virtually all GL monomers ended up in heterodimers, whereas a fraction of the M protein persisted as monomers. The M protein also formed covalently linked homodimers, but only the heterodimers were incorporated into virus particles.

The small envelope glycoprotein (GS) of equine arteritis virus folds into three distinct monomers and a disulfide-linked dimer.

The small membrane glycoprotein (GS) of equine arteritis virus (EAV) is a minor virion component but is abundantly expressed in EAV-infected cells. In this study, we have analyzed its membrane topology, folding, oligomerization, and intracellular transport. We show that GS is a class I integral membrane protein with one functional N-glycosylation site. Gel electrophoresis under nonreducing conditions revealed that GS occurs in EAV-infected cells in four monomeric conformations and as disulfide-linked homodimers. The slowest-migrating monomeric form corresponded to the fully reduced GS protein; the three faster-migrating monomeric species are probably generated by the formation of alternative intrachain disulfide bonds between the three luminal cysteines in the molecule. The GS monomers were selectively retained in the endoplasmic reticulum, as judged by their permanent susceptibility to endoglycosidase H, whereas the GS dimers were specifically incorporated into virus particles and became endoglycosidase H resistant and sialylated during passage through the Golgi apparatus.

Enzyme immunoassay with enhanced specificity for detection of antibodies to Chlamydia trachomatis.

Two different methods for preventing the binding of cross-reacting antibodies to the genus-reactive chlamydial lipopolysaccharide (LPS) were used to improve the specificity of an enzyme immunoassay for the determination of antibodies to Chlamydia trachomatis. Coated elementary bodies were treated with either sodium periodate, to oxidize the antigenic sites of the LPS, or Triton X-100, to extract the LPS. By using these new enzyme immunoassays, the standard enzyme immunoassay, and the whole inclusion fluorescence (WIF) assay, antibodies to C. trachomatis were determined in sera from different groups of patients and controls. Paired serum samples from patients with culture-proven urogenital C. trachomatis infections showed similar responses in all three assays. Paired serum samples from patients with Chlamydia psittaci infections showed similar responses in the WIF assay and the standard enzyme immunoassay, whereas significantly reduced titers were obtained in the enzyme immunoassays with treated antigen, especially in the convalescent-phase serum samples. Serum samples from patients with symptoms suggestive of infection with C. trachomatis, pregnant women, and blood donors were evaluated by all three types of assays. Eighty percent of the significant reductions in immunoglobulin G (IgG), IgA, and IgM titers were observed in sera with WIF assay titers in the lower classes (IgG, 1: < or = 256; IgA, 1: < or = 32; IgM, 1: < or = 16). From these results we conclude that oxidation of the antigen by sodium periodate is a simple and effective method of producing an enzyme immunoassay with enhanced specificity that could be useful for diagnostic purposes and seroepidemiological studies.

Late effects of cyclophosphamide and total body irradiation as a conditioning regimen for bone marrow transplantation in rats (a preliminary report).

The longterm survival and occurrence of neoplastic and nonneoplastic lesions following total body irradiation (TBI), 8.5 Gy, with or without additional cyclophosphamide (Cy; 100 mg kg-1 i.p.) treatment as a conditioning regimen for bone marrow transplantation (BMT) were studied in male BN/BiRij rats. The two groups of rats that were treated with Cy (Cy and Cy + TBI) that survived beyond 100 days after treatment, had a severely decreased median (post treatment) survival time (Cy + TBI: 14.5 months and Cy: 14.1 months). Survival time in the TBI group was moderately decreased (18.5 months) as compared with the untreated controls (27.2 months). All treatment modalities were carcinogenic according to the raw data. After Cy-treatment a high incidence of, frequently multiple, malignant nerve-sheath tumours (Cy: 66 per cent, Cy + TBI: 31 per cent, controls: 2 per cent) was observed. TBI induced an increased occurrence of a great variety of tumours, especially mesenchymal tumours. This effect was more pronounced in animals receiving TBI alone as compared to animals receiving the combined treatment of Cy + TBI; an effect that most likely resulted from the longer median survival after TBI. The multi-target effect of TBI was also reflected in the occurrence of nonneoplastic effects in a variety of tissues, including high incidences of biliary cysts in the liver and severe testicular atrophy. The most important Cy-induced nonneoplastic lesion was incisor dysplasia, which resulted in feeding problems that could only be partly overcome by administering powdered food. Early mortality in the Cy-treated groups was associated with emaciation and generalized organ atrophy. A more definitive estimate of the late effects of supralethal chemoradiotherapy as part of a treatment of malignant disease has to await the results of various conditioning regimens for BMT in rats employing the acute BN myelocytic leukaemia (BNML) as a rat model for human acute myelocytic leukaemia (AML).