Staphylococcus aureus internalization impairs osteoblastic activity and early differentiation process.

Staphylococcus aureus is the most frequent aetiology of bone and joint infections (BJI) and can cause relapsing and chronic infections. One of the main factors involved in the chronicization of staphylococcal BJIs is the internalization of S. aureus into osteoblasts, the bone-forming cells. Previous studies have shown that S. aureus triggers an impairment of osteoblasts function that could contribute to bone loss. However, these studies focused mainly on the extracellular effects of S. aureus. Our study aimed at understanding the intracellular effects of S. aureus on the early osteoblast differentiation process. In our in vitro model of osteoblast lineage infection, we first observed that internalized S. aureus 8325-4 (a reference lab strain) significantly impacted RUNX2 and COL1A1 expression compared to its non-internalized counterpart 8325-4∆fnbAB (with deletion of fnbA and fnbB). Then, in a murine model of osteomyelitis, we reported no significant effect for S. aureus 8325-4 and 8325-4∆fnbAB on bone parameters at 7 days post-infection whereas S. aureus 8325-4 significantly decreased trabecular bone thickness at 14 days post-infection compared to 8325-4∆fnbAB. When challenged with two clinical isogenic strains isolated from initial and relapse phase of the same BJI, significant impairments of bone parameters were observed for both initial and relapse strain, without differences between the two strains. Finally, in our in vitro osteoblast infection model, both clinical strains impacted alkaline phosphatase activity whereas the expression of bone differentiation genes was significantly decreased only after infection with the relapse strain. Globally, we highlighted that S. aureus internalization into osteoblasts is responsible for an impairment of the early differentiation in vitro and that S. aureus impaired bone parameters in vivo in a strain-dependent manner.

Efficacy of generic meropenem products in combination with colistin in carbapenemase-producing Klebsiella pneumoniae experimental osteomyelitis.

Guidelines for the management of carbapenemase-producing Enterobacterales (CPE) infections recommend a combination of two active agents, including meropenem if the minimum inhibitory concentration (MIC) is ≤8 mg/L. The therapeutic equivalence of meropenem generics has been challenged. We compared the bactericidal activity of meropenem innovator (AstraZeneca) and four generic products (Actavis, Kabi, Mylan and Panpharma), both in vitro and in vivo, in association with colistin. In vitro time-kill studies were performed at 4 × MIC. An experimental model of KPC-producing Klebsiella pneumoniae osteomyelitis was induced in rabbits by tibial injection of a sclerosing agent followed by 2 × 108 CFU of K. pneumoniae KPC-99YC (meropenem MIC = 4 mg/L; colistin MIC = 1 mg/L). At 14 days after inoculation, treatment for 7 days started in seven groups of ≥10 rabbits, including a control group, a colistin group, and one group for each meropenem product (i.e. the innovator and four generics), in combination with colistin. In vitro, meropenem + colistin was bactericidal with no viable bacteria after 6 h, and this effect was similar with all meropenem products. In the osteomyelitis model, there was no significant difference between meropenem generics and the innovator when combined with colistin. Colistin-resistant strains were detected after treatment with colistin + meropenem innovator (n = 3) and generics (n = 3). The efficacy of four meropenem generics did not differ from the innovator in vitro and in an experimental rabbit model of KPC-producing K. pneumoniae osteomyelitis in terms of bactericidal activity and the emergence of resistance.

[Functional immunoassays in the setting of infectious risk and immunosuppressive therapy of non-HIV immunocompromised patients]. / Place des tests immunitaires fonctionnels dans la prise en charge du risque infectieux et de la gestion des thérapies immunosuppressives chez les patients immunodéprimés non-VIH.

The holistic approach of the human immune system is based on the study of its components collectively driving a functional response to an immunogenic stimulus. To appreciate a specific immune dysfunction, a condition is mimicked ex vivo and the immune response induced is assessed. The application field of such assays are broad and expanding, from the diagnosis of primary and secondary immunodeficiencies, immunotherapy for cancer to the management of patients at-risk for infections and vaccination. These assays are immune monitoring tools that may contribute to a personalised and precision medicine. The purpose of this review is to describe immune functional assays available in the setting of non-HIV acquired immune deficiency. First, we will address the use of theses assays in the diagnosis of opportunistic infections such as viral reactivation. Secondly, we will report the usefulness of these assays to assess vaccine efficacy and to manage immunosuppressive therapies.

Colistin-containing cement spacer for treatment of experimental carbapenemase-producing Klebsiella pneumoniae prosthetic joint infection.

Carbapenemase-producing Enterobacteriaceae (CPE) are emerging multidrug-resistant bacteria responsible for invasive infections, including prosthetic joint infections (PJIs). Local administration of colistin may provide bactericidal concentrations in situ. This study evaluated the efficacy of a colistin-impregnated cement spacer, alone and in combination with systemic antibiotics, in a rabbit model of CPE-PJI. Elution of 3 MIU of colistimethate sodium (CMS) in 40 g of poly(methyl methacrylate) cement was studied in vitro. In vivo, 5 × 108 CFU of KPC-producing Klebsiella pneumoniae (colistin and meropenem MICs of 1 mg/L and 4 mg/L, respectively) were injected close to a prosthetic knee. Surgical debridement and prosthesis removal were performed 7 days later, and rabbits were assigned to six treatment groups (11-13 rabbits each): drug-free spacer; colistin-loaded spacer; colistin intramuscular (i.m.); colistin i.m. + colistin spacer; colistin i.m. + meropenem subcutaneous (s.c.); and colistin i.m. + meropenem s.c. + colistin spacer. Systemic treatment was administered at doses targeting pharmacokinetics in humans, and rabbits were euthanised 7 days later to evaluate bacterial counts in infected bones. In vitro, CMS elution was low (<0.1% at 24 h) but reached a local concentration of ≥20 mg/L (>20 × MIC). In vivo, combinations of local and systemic colistin, with or without meropenem, were the only regimens superior to the control group (P ≤ 0.05) in terms of viable bacterial counts and the proportion of rabbits with sterile bone, with no emergence of colistin-resistant strains. Colistin-loaded cement spacer in combination with systemic antibiotics were the most effective regimens in this CPE-PJI model.

Neovascularisation after surgery for recurrent saphenofemoral incompetence: does surgical dissection technique matter?

BACKGROUND: The effect of the type of surgery on neovascularisation in the groin is unknown. The aim of the present study was to compare three different surgical techniques used for recurrent saphenofemoral incompetence in view of their effect on neovascularisation in the groin at short- and long-term follow-up after surgery. PATIENTS AND METHODS: 36 consecutive patients undergoing surgery for recurrent saphenofemoral incompetence were randomised. 12 patients underwent sharp dissection with knife or scissors and excision and ligation of scar tissue using absorbable suture material; 12 had dissection with electrocoagulation and 12 dissection with ultrasound (Ultracision Harmonic Scalpel). Clinical outcome was assessed using the venous clinical severity score and venous disability score, and the saphenofemoral junction was evaluated by means of duplex sonography three months and seven years after the operation respectively. If neovascularisation was present, the maximal diameter of new refluxing veins in the groin was measured. RESULTS: There was no statistically significant difference between the three surgical techniques. Duplex ultrasound showed neovascularisation with an average maximal diameter (± standard error) of the newly formed refluxing vessel of respectively 2.00 (± 0.63) mm, 1.00 (± 0.45) mm and 0.50 (± 0.50) mm after three months and 4.29 (± 1.41) mm, 3.32 (± 0.90) mm and 3.00 (0.83) mm after seven years (no significant difference between groups). After seven years no reflux was detected in 8/36 patients, no varicose veins were found in 14/36 patients. The patients were less symptomatic than before our redo operation and no one needed reoperation within the seven years. CONCLUSIONS: Dissection techniques in the groin did not influence the clinical and sonographic result at 3 months and at 7 years after redo surgery for recurrent varicose veins.

[Infection with fasciola hepatica - a case series]. / Fasciola-hepatica-Infektionen in der Schweiz - eine Fallserie.

AIM: Described are the clinical and, especially, the contrast-enhanced ultrasonographic presentation and recovery of four cases of fascioliasis occurring between December 2008 and February 2009. MATERIALS AND METHODS: A detailed history, clinical examination and laboratory investigation were followed by contrast-enhanced ultrasonography of the liver and serological evidence for the presence of antibodies. A final contrast-enhanced ultrasound was performed 6 weeks after treatment with triclabendazole. RESULTS: The patients displayed a variety of symptoms ranging from vasospastic myocardial infarction diagnosed via coronary angiography and a first-time occurrence of migraine as a result of hypereosinophilia to fever with weight loss and tumor-like liver lesions. The contrast-enhanced ultrasonographic hepatic changes in fascioliasis are characterized by segmental arterial hyperemia with emphasis on the liver periphery and subcapsular canalicular sparing corresponding to parenchymal necrosis and hemorrhage. In the later phases areas with inflammatory changes were unmasked due to phlebitis of the small portal vessels and granulomatous parenchymal changes. All four patients were successfully treated with triclabendazole without experiencing any serious side effects. CONCLUSION: Contrast-enhanced ultrasonography is well suited for the diagnosis and monitoring of hepatic fascioliasis.

Truncular vascular malformations in a varicose vein surgery patient cohort.

BACKGROUND: To determine the incidence and significance of vascular malformations in a varicose vein surgery patient cohort in a prospective cohort study. PATIENTS AND METHODS: During a ten year time span we prospectively searched for patients with vascular malformations within a varicose vein surgery cohort. All patients underwent colour duplex sonography and surgery for symptomatic chronic venous disease or chronic venous insufficiency corresponding to clinical classes C2 to C6 according to CEAP. RESULTS: Five out of 1488 patients had truncular vascular malformations. One patient had an arterio-venous malformation in the groin. Venous malformations were found in three marginal veins and one bone perforating vein. Two of these five patients had a mitral valve prolapse syndrome, one a persistent foramen ovale, one had a bone cyst in a finger and one ectromelia of the hands and feet, respectively. No complications occurred following surgical treatment of these five malformations. CONCLUSIONS: Truncular arterio-venous and venous malformations in a varicose vein surgery patient cohort are rare. In our cohort the hemodynamic impact of the vascular malformations was low, the surgical treatment combined with varicose vein surgery resulted in technical and clinical success.

Primary surgery for sapheno-femoral incompetence: A randomised controlled trial to compare two techniques to reduce lymphatic complications.

BACKGROUND: We prospectively compared lymphatic complications after two types of surgery for primary sapheno-femoral incompetence: sharp dissection with meticulous ligation of lymphatic tissue and electrocoagulation technique respectively. PATIENTS AND METHODS: 154 consecutive patients undergoing surgery for bilateral primary sapheno-femoral incompetence were randomised. Each side was the control for the other side. 154 groins underwent sharp dissection with ligation of lymphatic tissue using absorbable suture material and 154 controls had a dissection performed with electrocoagulation. RESULTS: There was no lymphocoele, no relevant lymphorrhea and no extremity oedema in either group. Three patients had a minor lymphatic discharge in both groins, self-limiting within 24 hours (1.9%). There were no significant differences between the two groups. CONCLUSIONS: Lymphatic complications in primary surgery for sapheno-femoral incompetence are very rare. There is no detectable advantage of sharp dissection with ligation of lymphatic tissue over dissection with electrocoagulation without ligatures.

Tumors associated with superficial thrombophlebitis.

BACKGROUND: To assess the incidence of malignant tumors in patients with thrombophlebitis of the leg with regard to potential early tumor detection. PATIENTS AND METHODS: 140 consecutive patients were enrolled over a period of over 9 years in a retrospective follow-up study based on the electronic patient record. RESULTS: There were 18 patients (12.9%) suffering from thrombophlebitis in association with a malignant tumor: breast cancer in seven patients, colon carcinoma and haematologic cancer in four, skin cancer in three patients and one case each of oesophageal, prostatic, kidney and neck cancer . In two patients thrombophlebitis preceded the diagnosis of the malignancy. Superficial thrombophlebitis may have been associated in four cases (2.9%) with a benign tumor. CONCLUSIONS: Breast, colonic, haematological and skin cancer were mainly associated with superficial thrombophlebitis in our patients. In case of a thrombophlebitis without a known malignancy a thorough clinical examination with special regard to skin, breast and abdomen is mandatory.

Recurrence after surgery for varices in the groin is not dependent on body mass index.

OBJECTIVE: To investigate if the body mass index (BMI) differs between different groups of patients (incomplete ligation also defined as technical error, neo-revascularisation, uncertain and mixed) in recurrent same site inguinal varices after surgery (REVAS). METHODS: During a six and half year time span, we retrospectively analysed 203 consecutive procedures in 153 patients undergoing recurrent same site vein surgery in the groin. Individual BMI was calculated and compared within the different REVAS nature of the source groups. RESULTS: The median BMI was 28 for patients undergoing recurrent vein surgery in the groin with no relevant difference in BMI between the different source groups (confidence interval for the difference of adjusted group means equals [-1.5, 2.6]). CONCLUSIONS: There is no relevant difference in BMI between the two commonest REVAS groups. This may be due to small sample size, but confidence limits for difference of.

Follow-up after deep venous thrombosis in azygos continuation.

BACKGROUND: To determine the sequelae of patients after deep venous thrombosis inpatients with azygos continuation defined as agenesis of the inferior vena cava with collateral flow. PATIENTS AND METHODS: Five patients post deep venous thrombosis in the context of azygos continuation were followed up clinically and with colour duplex ultrasonography. RESULTS: All five patients had to our knowledge after the initial deep venous thrombosis no further thromboembolic events. Three patients after isolated iliac thromboses are symptom free or nearly symptom free, two after more extended thromboses still sufferfrom venous claudication. Four patients are without anticoagulation, one patient is permanently orally anticoagulated. CONCLUSIONS: Azygos continuation may not influence the risk of recurrent venous thrombo-embolism nor the outcome of a deep venous thrombosis. Careful deep venous thrombosis prophylaxis in patients with azygos continuation may be sufficient when a risk factor is present but conclusions lack due to the small numbers of patients of enough supportive data.

A randomised trial of ultrasonic dissection versus electrocoagulation to reduce lymphatic complications after surgery for recurrent sapheno-femoral incompetence.

OBJECTIVE: Prospectively to compare lymphatic drainage after ultrasonic dissection, an electrocoagulation technique and sharp dissection in the groin during surgery for recurrent sapheno-femoral incompetence. DESIGN: Prospective, randomised study comparing three surgical techniques. METHODS: Thirty-six consecutive patients undergoing surgery for recurrent sapheno-femoral incompetence were randomised. Twelve patients underwent dissection with ultrasound, 12 with electrocoagulation and 12 controls had sharp dissection with ligation of scar and lymphatic tissue using absorbable suture material. RESULTS: The mean drain output per patient was 13.5 ml in the ultrasonic group, 15.4 ml in the electrocoagulation group and 8.3 ml in the suture ligation group. Six minor cases of lymphatic leakage occurred in the ultrasonic group. This resulted in no clinical problem. There were no other significant differences between the three groups. CONCLUSIONS: There is no detectable advantage for the use of ultrasound or electrocoagulation in recurrent saphenous high ligation compared to sharp dissection.

Morbidity in superficial thrombophlebitis and its potential surgical prevention.

Thrombophlebitis is a common condition which can lead to deep venous thrombosis (DVT) and subsequent pulmonary embolism (PE). Thrombophlebitis can reach the deep venous system via the long or short saphenous vein or via perforating veins. Between the 1st of January 1999 and the 31st of December 2000 a total of 17 cases of superficial (or ascending) thrombophlebitis closer than 5 cm to the deep venous system were surgically treated in our clinic. 14 times the long saphenous vein was affected and 3 times the short-saphenous vein. The age of the nine females and seven males ranged from 31 to 77 (mean of 54.6) years. Duplex ultrasound was performed in all patients. In the case of a deep venous thrombosis (four cases) a computer tomography scan (CT) of the pelvis and abdomen was performed to define the extension of DVT. In all 17 (100%) cases a high ligation (crossectomy) and in four (23.5%) cases a venous thrombectomy was performed. In all of these four cases the DVT was limited to the common femoral vein. In all seventeen procedures including venous thrombectomy there was no mortality and no relevant morbidity. Mean hospitalization time was 3.1 days for crossectomy with thrombectomy, and 1.8 days for crossectomy alone. Follow-up has been so far uneventful (mean follow-up time being 12 months in the case of a DVT). In the literature there is no clear concept of how to treat, conservatively or operatively, ascending thrombophlebitis. The surgical procedure can be performed under local anesthesia, and it is safe and efficient.

A randomized controlled trial to determine the effect of humidified carbon dioxide (CO2) insufflation on postoperative pain following thoracoscopic procedures.

BACKGROUND: It has previously been shown that the insufflation of humidified gas during laparoscopy results in less postoperative pain than is observed following the use of dry gas. Experimental evidence also suggests that dry gas insufflation during thoracoscopy results in greater structural injury to the pleura than occurs with the use of humidified gas. The present study was designed to determine the effect of humidified gas insufflation on postoperative pain following thoracoscopic procedures. METHODS: Forty consecutive patients were prospectively randomized. Twenty patients were insufflated with humidified carbon dioxide (CO(2)), and 20 control patients received standard dry CO(2). RESULTS: The patients' analogue pain score was significantly lower following humidified gas insufflation compared to dry gas insufflation when assessed at 6 h postoperatively, as well as on the 1st, 2nd, 3rd, and 14th postoperative days. The postoperative morphine consumption was lower in the humidified group than it was in the control group. The incidence of respiratory complications was identical for both groups. CONCLUSION: The use of humidified gas appears to reduce postoperative pain but not the rate of respiratory complications.

Proximalized lateral tunnel for the bypass to the dorsalis pedis artery -- a safe way to go.

BACKGROUND: Wound complications associated with bypass grafting to the dorsalis pedis artery are frequent, and threaten the viability of the bypass and the limb. METHODS: The long saphenous vein can be tunneled from its bed down the lateral side of the anterior margin of the tibia for subsequent anastomosis with the dorsalis pedis artery. CONCLUSION: The proximalized lateral tunnel for the bypass to the dorsalis pedis artery has the advantage of protecting the bypass graft from exposure if the patient develops wound breakdown.

Is the function of the serratus anterior muscle disturbed following division during a standard thoracotomy?

In a prospective study the functional results after dissection or preservation of the serratus anterior muscle in the postero-lateral standard thoracotomy were evaluated. In 14 patients of our clinic with dissection and suture and in 14 patients with preservation of the serratus muscle the muscle function was assessed and compared preoperatively, within the first two post-operative weeks, and three months after the operation by the same physiotherapists. The two groups were blinded in regard to age, original disease, and mode of intervention. We compared the wing position of the scapula in the sitting position and the positioning of the scapula at fixation of the shoulder joint in the sitting and in the supine position. Using a four-grade function assessment scheme, both groups obtained the same functional results. There was no seroma in either group. After 2.8 (2.5 to 3.0) years all the surviving patients described symmetric functional conditions. We therefore conclude that in order to achieve a better view of the operative field the serratus muscle may be dissected close to the origin if it is then readapted.

Bronchial anatomy and single-lung ventilation in the pig.

PURPOSE: To explore why two pigs died in the course of a study in which a double-lumen tube (DLT) was used to achieve single-lung ventilation, the bronchial anatomy of all six pigs involved in the study was examined at autopsy. METHODS: Autopsy involved examination of the lungs in situ and subsequent dissection of the lung tissue from the lobular bronchi. RESULTS: All six pigs were found to have an apical lobe (or lobular) bronchus arising from the trachea. In three it was on the right, as is usual in pigs, and in three, including the two that died, it was on the left. The mainstem bronchi to both lungs were short in all pigs, with major segmental bronchi arising just distal to the carina. CONCLUSION: The bronchial anatomy of the pig is such that the inflated cuffs of commercially available DLTs may cause partial or complete obstruction of the apical bronchi of one or both lungs, regardless of the side of the tracheal bronchus. The transmission of the resulting breath sounds across the narrow pig thorax can make auscultation unhelpful in assisting with optimal tube placement.