Description of a "trans-Saharan" strain of human T-lymphotropic virus type 1 in West Africa

The aim of this study was to assess the prevalence and the molecular epidemiology of human T-lymphotropic virus type 1 (HTLV-1) in a group of pregnant women living in Guinea Bissau. We studied 427 consecutive pregnant women attending 10 centers for HIV-1 infection monitoring in Bissau. HTLV-1 infection was found in 2.6% of the patients. Phylogenetic analysis of the long terminal repeat region showed that 10 isolates were of the cosmopolitan subtype (HTLV-1a) and that only 1 was of the widespread Central African subtype (HTLV-1b). All the cosmopolitan isolates belonged to the HTLV-1aD subgroup, which was first described in North Africa and clustered with other Senegal and Guinea isolates to form a significant West African clade. Our data show a high prevalence of HTLV-1 in Guinea Bissau and suggest the existence of a trans-Saharan strain distributed in North and West Africa, which probably crossed the desert in the past as a result of contacts between nomadic and sedentary populations or along trading routes.     

Corticospinal excitability during painful self-stimulation in humans: a transcranial magnetic stimulation study

We investigated changes in the corticospinal pattern of activity in healthy volunteers during sustained noxious and non-noxious mechanical stimulation of the first hand digit, resulting from active (self-stimulation) or passive (externally-induced) pressing against a sharp or blunted tip. The results indicate that, in order to press a finger onto a noxious stimulus with the same force generated to press onto a non-noxious one, the motor cortex adopts a peculiar strategy in terms of recruitment of motor units. This is reflected by an increase of corticospinal excitability (as revealed by motor potentials evoked by transcranial magnetic stimulation of the contralateral primary motor cortex) and EMG activity of agonist muscles, possibly related to an increase of motor unit synchronization.     

Graft materials and bone marrow stromal cells in bone tissue engineering

Bone augmentation procedures rely on osteogenic/osteoconductive properties of bone graft material (BGM). A further improvement is represented by use of autologous bone marrow stromal cells (BMSC), expanded in vitro and seeded on BGM before implantation in the bone defect. The effect of different BGMs on BMSC osteogenic differentiation was evaluated. BMSC were cultured in vitro in the presence of different BGM (natural, synthetic, and mixed origins). Cellular morphology was analyzed with scanning electron microscopy. The capability of BMSC to differentiate was determined in vitro by alkaline phosphatase gene expression and enzyme activity at different time points (7, 14, and 28 days) and in vivo by ectopic bone formation of implanted tissue constructs in an immunodeficient murine model. BGM supports the cell adhesion and osteogenic differentiation of BMSC developing a useful tool in the bone tissue engineering.     

A tissue engineering approach to bone repair in large animal models and in clinical practice

The repair of large segmental bone defects due to trauma, inflammation and tumor surgery remains a major clinical problem. Animal models were developed to test bone repair by tissue engineering approaches, mimicking real clinical situations. Studies differed with regard to animals (dog, sheep, goat), treated bone (femur, tibia, mandible), chemistry and structure of the scaffolds. Still, an advantage in the bone formation and in the healing of the segmental defect was always observed when scaffolds were seeded with bone marrow derived stromal cells (BMSCs). In the year 1998 was performed the first implantation of a porous ceramic construct in a bone segmental defect of a patient; it was the first construct seeded with cultured autologous osteogenic cells. Since then, only few other similar cases were treated by the same approach. However, in other fields, such as oral and maxillofacial surgery, injectable cells/platelet-rich plasma composites have been used as grafting materials for maxillary sinus floor augmentation and/or onlay plasty. More recently, the reconstruction of a human mandible was also reported by means of a bone-muscle-flap in vivo prefabrication technique, where the patient served as his own bioreactor. Indeed continuous implementations test and provide new means of defects treatment and cure. However, based on results so far obtained in animal models and pilot clinical studies, one can affirm that the bone tissue engineering approaches, although successful in most cases, need further validation before a wide application in clinics. In particular, the supply of oxygen and nutrients to the cells in the inner part of the implanted scaffolds remains a major concern, requiring additional investigations.     

Stem cells associated with macroporous bioceramics for long bone repair: 6- to 7-year outcome of a pilot clinical study

Extensive bone loss is still a major problem in orthopedics. A number of different therapeutic approaches have been developed and proposed, but so far none have proven to be fully satisfactory. We used a new tissue engineering approach to treat four patients with large bone diaphysis defects and poor therapeutic alternatives. To obtain implantable three-dimensional (3D) living constructs, cells isolated from the patients' bone marrow stroma were expanded in culture and seeded onto porous hydroxyapatite (HA) ceramic scaffolds designed to match the bone deficit in terms of size and shape. During the surgical session, an Ilizarov apparatus or a monoaxial external fixator was positioned on the patient's affected limb and the ceramic cylinder seeded with cells was placed in the bone defect. Patients were evaluated at different postsurgery time intervals by conventional radiographs and computed tomography (CT) scans. In one patient, an angiographic evaluation was performed at 6.5 years follow-up. In this study we analyze the long-term outcome of these patients following therapy. No major complications occurred in the early or late postoperative periods, nor were major complaints reported by the patients. No signs of pain, swelling, or infection were observed at the implantation site. Complete fusion between the implant and the host bone occurred 5 to 7 months after surgery. In all patients at the last follow-up (6 to 7 years postsurgery in patients 1 to 3), a good integration of the implants was maintained. No late fractures in the implant zone were observed. The present study shows the long-term durability of bone regeneration achieved by a bone engineering approach. We consider the obtained results very promising and propose the use of culture-expanded osteoprogenitor cells in conjunction with porous bioceramics as a real and significant improvement in the repair of critical-sized long bone defects.     

Comparison of Cytomegalovirus (CMV) Enzyme-Linked Immunosorbent Spot and CMV Quantiferon Gamma Interferon-Releasing Assays in Assessing Risk of CMV Infection in Kidney Transplant Recipients

Assessing cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) represents an appealing strategy for identifying transplant recipients at risk of infection. In this study, we compared two gamma interferon-releasing assays (IGRAs), Quantiferon-CMV and CMV enzyme-linked immunosorbent spot (ELISPOT), to determine the ability of each test to predict protective CMV-specific T-cell responses. Two hundred twenty-one Quantiferon-CMV and ELISPOT tests were conducted on 120 adult kidney transplant recipients (KTRs), including 100 CMV-seropositive transplant recipients (R⁺) and 20 CMV-seronegative transplant recipients of a CMV-positive donor (D⁺/R⁻). As a control cohort, 39 healthy adult subjects (including 33 CMV-seropositive and 6 CMV-seronegative subjects) were enrolled. CMV IgG serology was used as a reference for both tests. In the CMV-seropositive individuals, the ELISPOT and Quantiferon-CMV assays provided 46% concordance with the serology, 12% discordance, 18% disagreement between ELISPOT or Quantiferon-CMV and the serology, and 24% gray areas when one or both tests resulted in weak positives. None of the CMV-seronegative subjects showed detectable responses in the ELISPOT or the Quantiferon-CMV test. In transplant recipients, both the ELISPOT and Quantiferon-CMV assays positively correlated with each other and negatively correlated with CMV DNAemia in a significant way (P < 0.05). During the antiviral prophylaxis, all 20 D⁺/R⁻ KTRs we examined displayed undetectable Quantiferon-CMV and ELISPOT results, and there was no evidence of CMV seroconversion. The receiving operator curve (ROC) statistical analysis revealed similar specificities and sensitivities in predicting detectable viremia (areas under the curve [AUC], 0.66 and 0.62 for Quantiferon-CMV and ELISPOT, respectively). ELISPOT and Quantiferon-CMV values of >150 spots/200,000 peripheral blood mononuclear cells (PBMCs) and >1 to 6 IU gamma interferon (IFN-γ) were associated with protection from CMV infection (odds ratios [OR], 5 and 8.75, respectively). In transplant recipients, the two tests displayed similar abilities for predicting CMV infection. Both the ELISPOT and Quantiferon-CMV assays require several ameliorations to avoid false-negative results.     

A PCR-colorimetric microwell plate hybridization assay for detection of Mycobacterium tuberculosis and M. avium from culture samples and Ziehl-Neelsen-positive smears

Differentiation between Mycobacterium tuberculosis and M. avium is essential for the treatment of mycobacterial infections. We have developed an easy and rapid detection assay for the diagnosis of mycobacterial diseases. This is a PCR-hybridization assay based on selective amplification of a 16S rRNA gene sequence using pan-Mycobacterium primers followed by hybridization of the amplification products to biotinylated M. tuberculosis and M. avium-specific probes. A total of 55 mycobacterial isolates were tested. For all isolates, results concordant with those of conventional identification methods were obtained. Moreover, we developed a method for extraction of DNA from Ziehl-Neelsen-positive smears which allows the recovery of intact target DNA in our PCR-hybridization assay. Our method was able to confirm all culture results for 59 Ziehl-Neelsen-positive smears from clinical specimens (35 sputum, 11 lymph node biopsy, 6 stool, 4 pus, 2 urine, and 1 pericardial fluid specimens). These data suggest that our PCR-hybridization assay, which is simple to perform and less expensive than commercial probe methods, may be suitable for the identification of M. tuberculosis and M. avium. It could become a valuable alternative approach for the diagnosis of mycobacterial infections when applied directly to DNA extracted from Ziehl-Neelsen-positive smears as well.     

Antioxidant treatment of hindlimb-unloaded mouse counteracts fiber type transition but not atrophy of disused muscles

Oxidative stress was proposed as a trigger of muscle impairment in various muscle diseases. The hindlimb-unloaded (HU) rodent is a model of disuse inducing atrophy and slow-to-fast transition of postural muscles. Here, mice unloaded for 14 days were chronically treated with the selective antioxidant trolox. After HU, atrophy was more pronounced in the slow-twitch soleus muscle (Sol) than in the fast-twitch gastrocnemius and tibialis anterior muscles, and was absent in extensor digitorum longus muscle. In accord with the phenotype transition, HU Sol showed a reduced expression of myosin heavy chain type 2A (MHC-2A) and increase in MHC-2X and MHC-2B isoforms. In parallel, HU Sol displayed an increased sarcolemma chloride conductance related to an increased expression of ClC-1 channels, changes in excitability parameters, a positive shift of the mechanical threshold, and a decrease of the resting cytosolic calcium concentration. Moreover, the level of lipoperoxidation increased proportionally to the degree of atrophy of each muscle type. As expected, trolox treatment fully prevented oxidative stress in HU mice. Atrophy was not prevented but the drug significantly attenuated Sol phenotypic transition and excitability changes. Trolox treatment had no effect on control mice. These results suggest possible benefits of antioxidants in protecting muscle against disuse.     

Barbed versus traditional suture for enterotomy closure after laparoscopic right colectomy with intracorporeal mechanical anastomosis: a case–control study

Our aim was to establish the safety and efficacy of barbed suture for enterotomy closure after laparoscopic right colectomy with intracorporeal anastomosis. This study included 47 patients who underwent laparoscopic right hemicolectomy with intracorporeal mechanical anastomosis and barbed suture enterotomy closure (barbed suture closure—BSC) for adenocarcinoma (with the exception of T4 lesions and metastasis), compared with 47 matched patients who underwent laparoscopic right hemicolectomy with intracorporeal mechanical anastomosis and conventional suture enterotomy closure (conventional suture closure—CSC) during the same period. Controls were matched for stage, age, and gender via a statistically generated selection of all laparoscopic right hemicolectomies performed from January 2009 until December 2015. There was no difference between the two groups in terms of age, sex, BMI, ASA, co-morbidity, previous abdominal surgery, cancer site and cancer staging. In terms of operating time (median 120 min for BSC and 127.5 min for CSC), histopathological results, surgical site complications (2.1% for BSC and 8.5% for CSC), hospitalization (median 6 days for BSC and 5 days for CSC), readmission rate (0%), there were no differences between the groups (p > 0.05). No significant differences were noted between the two groups in terms of the postoperative course. Our results support that the use of knotless barbed sutures for enterotomy closure after laparoscopic right colectomy with intracorporeal mechanical anastomosis is safe and reproducible.     

Cardiac and skeletal muscle adaptations to training in systemic hypertension and effect of beta blockade (metoprolol or propranolol)

Cardiovascular and peripheral adaptations to an aerobic conditioning program were studied in 30 hypertensive adults taking either placebo, beta 1-selective beta-adrenergic blocker (metoprolol) or beta 1-nonselective beta-adrenergic blocker (propranolol). The placebo group increased aerobic capacity (VO2max) 24% (p less than 0.002), largely explained by an increased peripheral arteriovenous (AV) oxygen difference with minimal changes in cardiac size and function. Resting blood pressure and total systemic resistance also decreased. The group taking a beta 1-selective beta blocker increased VO2max 8% (p less than 0.05), reduced resting blood pressure but had no significant change of AV oxygen difference or cardiac size or function. The group taking the beta 1-nonselective beta blocker propranolol had no increase in VO2max, no decrease in resting blood pressure and no cardiovascular or peripheral adaptations to the exercise program. Thus, beta 1-selective and beta 1-nonselective beta blockers attenuate conditioning in hypertensive patients to differing degrees, in each case by blocking peripheral mechanisms of conditioning.