Combined serum biomarker analysis shows no benefit in the diagnosis of periprosthetic joint infection.

PURPOSE: In many cases, the diagnosis of a periprosthetic joint infection (PJI) consisting of the clinical appearance, laboratory tests, and other diagnostic tools remains a difficult task. Single serum biomarkers are easy to collect, are suitable for periodical assessment, and are a crucial tool in PJI diagnosis, but limited sensitivity or specificity is reported in literature. The aim of this study was to combine the best-performing single serum biomarkers into a multi-biomarker model aiming to improve the diagnostic properties. METHODS: Within a 27-month period, 124 surgical procedures (aseptic or septic revision total knee arthroplasty (TKA) or total hip arthroplasty (THA)) were prospectively included. The serum leukocyte count, C-reactive protein (CRP), interleukin-6, procalcitonin, interferon alpha, and fibrinogen were assessed 1 day prior to surgery. Logistic regression with lasso-regularization was used for the biomarkers and all their ratios. After randomly splitting the data into a training (75%) and a test set (25%), the multi-biomarker model was calculated and validated in a cross-validation approach. RESULTS: CRP (AUC 0.91, specificity 0.67, sensitivity 0.90, p value 0.03) and fibrinogen (AUC 0.93, specificity 0.73, sensitivity 0.94, p value 0.02) had the best single-biomarker performances. The multi-biomarker model including fibrinogen, CRP, the ratio of fibrinogen to CRP, and the ratio of serum thrombocytes to CRP showed a similar performance (AUC 0.95, specificity 0.91, sensitivity 0.72, p value 0.01). CONCLUSION: In this study, multiple biomarkers were tested for their diagnostic performance, with CRP and fibrinogen showing the best results regarding the AUC, accuracy, sensitivity, and specificity. It was not possible to further increase the diagnostic accuracy by combining multiple biomarkers using sophisticated statistical methods.

Pressure-induced orientation control of the growth of epitaxial silicon nanowires.

Single crystal silicon nanowires (SiNWs) were synthesized with silane reactant using Au nanocluster-catalyzed one-dimensional growth. We have shown that under our experimental conditions, SiNWs grown epitaxially on Si(111) via the vapor-liquid-solid growth mechanism change their growth direction as a function of the total pressure. Structural characterization of a large number of samples shows that SiNWs synthesized at a total pressure of 3 mbar grow preferentially in the 111 direction, while the one at 15 mbar favors the 112 direction. Specifically by dynamically changing the system pressure during the growth process morphological changes of the NW growth directions along their length have been demonstrated.

Some aspects of substrate pretreatment for epitaxial Si nanowire growth.

We report on the influence of the surface pretreatment for vapor-liquid-solid growth of epitaxial silicon nanowires with gold catalyst and silane precursor on Si(111) substrates. In this paper we make it obvious that a thin native oxide layer on the Si substrate-as is present under most technological conditions-or a thin layer of oxide formed on top of the catalytic gold particle restrain nucleation and nanowire growth. High resolution transmission electron microscopy, and electron energy loss spectroscopy were utilized to demonstrate Si diffusion from the substrate through the catalytic Au layer and further the formation of a thin oxide layer atop. Based on this observation we present a sample pretreatment practice, making the catalyst insensitive for further oxide formation, thereby preserving epitaxy for nanowire synthesis.

Nutrient profiles in retail cuts of bison meat.

The objectives were to determine the nutrient composition and variation in eight cuts of bison meat in bulls and heifers and identify nutrient relationships in the clod and sirloin by principal component analysis. The nutrients analyzed were: energy, protein, total fat, saturated fat, monounsaturated fat, polyunsaturated fat, transfat, cholesterol, vitamin A, Ca, Fe, Na and moisture. Differences were observed in fat components between cuts and bulls had higher (P<0.05) amounts of total, saturated, monounsaturated and polyunsaturated fat in the blade compared to the other cuts. The sirloins had less (P<0.05) cholesterol than all the other cuts in bulls and the clod in heifers. Fat varied more than protein and moisture in all cuts. Four principal components (PC) accounted for 63.9% of the total variation of the nutrient composition. Total, monounsaturated and saturated fats were in PC1 and cholesterol in PC2 showing that cholesterol is independent of other fats. If dietary alterations elicit changes in bison meat fatty acid profiles, it may be possible to reduce cholesterol independent of total, monounsaturated or saturated fat.

Platyamoeba pseudovannellida n. sp., a naked amoeba with wide salt tolerance isolated from the Salton Sea, California.

A new species of naked amoeba, Platyamoeba pseudovannellida n.sp., is described on the basis of light microscopic and fine structural features. The amoeba was isolated from the Salton Sea, California, from water at a salinity of ca. 44%. Locomotive amoebae occasionally had a spatulate outline and floating cells had radiating pseudopodia, sometimes with pointed tips. Both these features are reminiscent of the genus Vannella. However, the surface coat (glycocalyx) as revealed by TEM indicates that this is a species of Platyamoeba. Although salinity was not used as a diagnostic feature, this species was found to have remarkable tolerance to fluctuating salinity levels, even when changes were rapid. Amoebae survived over the range 0 per thousand to 150 per thousand salt and grew within the range 0 per thousand to 138 per thousand salt. The generation time of cells averaged 29 h and was not markedly affected by salt concentration. This is longer than expected for an amoeba of this size and suggests a high energetic cost of coping with salinity changes. The morphology of cells changed with increasing salinity: at 0 per thousand cells were flattened and active and at the other extreme (138 per thousand) amoebae were wrinkled and domed and cell movement was very slow. At the ultrastructural level, the cytoplasm of cells grown at high salinity (98 per thousand was considerably denser than that of cells reared at 0 per thousand.

Subfascial Endoscopic Perforator Vein Surgery [SEPS] and Fasciotomy: Treatment of Severe Chronic Venous Disease.

Chronic leg ulceration affects about 1 to 2 % of the European population. Although the pathogenesis of venous ulceration is not completely understood, it is generally agreed that the transmission of high ambulatory pressures through incompetent perforating veins plays a major role. There are only limited data available to assess the long-term prognosis for leg ulcer patients.

Development of endoscopic dissection of perforating veins and fasciotomy for treatment of chronic venous insufficiency.

As the subfascial endoscopic perforator vein surgery (SEPS) has become increasingly popular, it becomes important to trace the development of this procedure first initiated in 1985. (Improvements in the technique and modifications of initial instrumentation have occurred. These changes are based on experience with greater than 1000 patients treated since 1980 at Krankenhaus der Barmherzigen Brüder in Munich, Klinikum Merheim in Cologne, and the Weilheim Hospital. Results obtained in 96 patients (140 legs) were examined retrospectively and are presented as well as the prospective evaluation of 39 patients with 56 operated legs. (Hauer G, Vasa 1985, 14:59-61; Hauer G, Barkun J, Wisser I, Deiler S, Surg Endosc 1988, 2:5-12; Schneidemann B, Inaug Diss, 1985). This report details the fact that in using our own instruments, including a specially designed videoscope, it has been possible to approach perforating veins of the medial anterior and posterior compartments. This can be done through a 2 cm incision in the proximal calf. Using these instruments, it has been possible to perform a fasciotomy under direct vision. This summary emphasizes that it is not necessary to locate perforating veins preoperatively, and that wound infection and recurrent ulcerations do not occur. This allows application of the method to patients with open ulcers. Further, this report emphasizes that patients with combined arterial and venous ulceration require arterial reconstruction rather than perforator vein interruption. The SEPS operation is relatively contraindicated if there is widespread necrosis and infection of the fascia, especially in combination with ankle ankylosis. In addition, this is the method of choice in patients with multiple incompetent perforating veins with or without open venous ulceration.

[Evaluation of the effect of professional dental cleaning and education in dental hygiene in type 1 diabetic patients]. / Studie zur Uberprüfung des Effektes einer professionellen Zahnreinigung und einer Schulung in Zahnhygiene bei Typ 1-Diabetikern.

In the setting of a prospective, randomized trial the impact of professional oral hygiene and of intensive patient education in oral hygiene was investigated. It was studied, whether in young to middle-aged type 1 diabetic patients the risk or the progression of periodontal disease can be influenced during one year. Primary endpoint was bleeding at probing, secondary indices, the plaque index and probing pocket depth. 83 patients were enrolled, 70 completed the study according to the protocol. Oral cleansing was dramatically improved by education in the short term, however, the effect was much weaker after 6 and 12 months, respectively, although there remained some improvement compared to the basic level. Bleeding at probing increased in both groups, without reaching the level of statistical significance. Probing pocket depth increased in the intervention group weakly but significantly and remained unchanged in the control group. The tested intervention (professional oral hygiene, patient education in oral hygiene) could not improve the periodontal status in our type 1 patients.

[Chronic venous insufficiency]. / Die chronisch-venöse Insuffizienz.

In severe chronic venous insufficiency (CVI) the fascia cruris is increasingly involved in the pathological process. The resulting loss of compliance as a consequence of altered fascia texture leads to increased pressure in the compartments of the lower extremity, followed by reduced circulation. Arteries and nerves, which penetrate the fascia along with insufficient perforating veins, are damaged through the increased pressure and are therefore functionally impaired. Accordingly many pathological changes in the crural ulcer have their anatomical substrate here. The microcirculation is distributed by either primary varicosis with secondary insufficiency of the deep veins or by primary insufficiency of the deep venous system as seen in a post-thrombotic syndrome. Subsequent therapy should be based on this knowledge and therefore consists of medication and basic physical therapy along with dissection of the perforating veins-fasciotomy and fasciectomy combined with plastic surgery. All of the therapeutic measures have to take the stage of the CVI into consideration. In order to eliminate the insufficient perforating veins and to perform fasciotomy the endoscopic approach is considered the state of the art. In extreme cases, only fasciectomy combined with plastic surgery can lead to durable healing.

[Surgery of perforant veins]. / Chirurgie der Perforansvenen.

The eradication of incompetent perforating veins combined with fasciotomy is a successful concept in the therapy of leg ulcers. Both can be achieved by endoscopy. Under endoscopic control, the medial, anterior, and posterior groups of perforating veins can be prepared at different levels and dissected after bipolar coagulation. Under endoscopic control the superficial fasciae of the leg are split.

Mycobacterium bovis infection in humans exposed to elk in Alberta.

The evidence of zoonotic transmission of M. bovis infection in the 1 veterinarian is confirmed by growth of the organism from his sputum 6 months after animal contact. The high rate of initial tuberculin reactivity and the skin test conversions of 6 persons in contact with culture-positive animals strongly suggest that further human infection has taken place. However, the lack of baseline testing on 48/81 test-positive individuals and the relatively high proportion of immigrants in some occupational groups makes it impossible to determine the extent of reactivity and infection that can be attributed to handling diseased elk. The method of spread is likely by aerosolization of infected particles produced from the cough of live animals, or by the housing of infected material in the rendering plant or postmortem laboratory. Although isoniazid prophylaxis has not been demonstrated to be protective against M. bovis reactivation disease, it seems reasonable to offer the drug to those contacts who are newly infected. Follow-up of human contacts of animal tuberculosis must be carried out.

[Diagnosis and surgical management of varicosities]. / Diagnostik und chirurgische Therapie der Varikosis.

The diagnosis of varicose veins is based on historical details pertaining to risk factors such as familial preponderance, advanced age, overweight, multiple births, professional activities carried out mainly in the standing or sitting position, use of oral contraceptives, diuretics or drugs which lower venous tone. Swelling of the legs on prolonged recumbancy, during pregnancy, fractures or cast treatment may be associated with thrombosis (Table 1). In addition to inspection and palpation in the standing and lying positions, the status of the pulses and the joints are of importance. The diagnostic measures must clarify the stage of the chronic venous insufficiency and provide adequate information on the various forms of venous functional disturbances (Table 2). Classification of varicose veins is carried out according to etiology--primary or secondary--or according to anatomical and functional derangement: with varicosities of the great saphenous vein and the lesser saphenous vein, in addition to valve incompetence at the proximal confluence of the saphenous-femoral junction, there may be segmental or global valve incompetence frequently in combination with a perforating vein incompetence. Varicosities of the great saphenous vein are classified with respect to whether the venous valves involved are those only in the region of the proximal confluence or from the inguinal region to above or below the knee or to the ankle, respectively, in four degrees of severity (Figure 1). For varicosities of the lesser saphenous vein, three degrees of severity are differentiated, the confluence incompetence, incompetence of the venous valves from the knee to the middle of the lower leg or from the knee to the ankle.4+ as the postthrombotic syndrome. Chronic venous insufficiency is characterized by venous hypertension and subdivided into three degrees of severity: grade I in the presence of corona phlebectatica paraplantaris and stasis edema; grade II in the presence of hyperpigmentation, melanodermitis, atrophy blanche, stasis induration and hypodermitis; grade III in the presence of hyperpigmentation, melanodermitis, atrophy blanche, stasis induration and hypodermitis; grade III in the presence of healed or florid ulceration. The two most important diagnostic measures are Doppler ultrasonography and ascending pressure phlebography which complement each other (Table 3)...

[Effect of endoscopy on surgery of veins]. / Der Einfluss der Endoskopie auf die Chirurgie der Venen.

Endoscopic techniques influence the diagnosis and management of surgical problems more and more. The endoscopic subfascial dissection (ESDP) of incompetent venous perforators, which are often found in conjunction with a venous stasis ulcer, is a prime example. The two principles of surgical management, the interruption of blood flow through the perforators and the performance of a medial paratibial fasciotomy, are fulfilled with this technique. The evaluation of this new operative extraluminal endoscopic procedure using specific criteria suggests that it will become increasingly wide-spread.

[Endoscopic dissection of perforating veins]. / Endoskopische Perforansdissektion.

The eradication of incompetent perforating veins in combination with fasciotomy is an effective way of treating advanced postphlebitic leg ulcers. Our newly developed endoscopic instrument can be used with both techniques. First the superficial fasciae of the leg are split, and then the perforating veins at different levels are located, injected with anticoagulant and severed. Preliminary clinical studies have reported very encouraging results: leg ulcers healed in all cases and the venous function was improved.

Endoscopic subfascial discission of perforating veins.

The insufficiency of perforating veins is thought to be crucial in the pathogenesis of varicose and postphlebitic ulcers as well as postoperative varicose vein recurrence. Their eradication is a valid and effective therapeutic concept. No presently available technique has yielded satisfactory results, hence our efforts to develop a new method: the endoscopic subfascial discission of perforating veins (ESDP). It involves performing a small incision in an area remote from the point of trophic disturbance and allows the operator to accurately and atraumatically perform a subfascial discission of the perforating veins where they join the deep veins under direct endoscopic control. Our initial experience with the technique showed promising results: 78%-93% good and very good results depending on the clinical parameters applied. These are the results of a follow-up period of up to 14 months. During that time, none of our patients developed a complication or recurrence. Our technique has many advantages over traditional techniques of perforator vein eradication: (1) more accurate localization; (2) improved wound healing, (3) dependable occlusion; (4) immediate postoperative mobilization of the patient. We feel that ESDP represents a major advance in the development of better methods of subfascial perforator vein eradication. Greater experience and a longer follow-up period will, however, be required to confirm this initial observation.