Local vanadium release from a calcium sulfate carrier accelerates fracture healing

This study evaluated the efficacy of using calcium sulfate (CaSO₄) as a carrier for intramedullary delivery of an organic vanadium salt, vanadyl acetylacetonate (VAC) after femoral fracture. VAC can act as an insulin‐mimetic and can be used to accelerate fracture healing in rats. A heterogenous mixture of VAC and CaSO₄ was delivered to the fracture site of BB Wistar rats, and mechanical testing, histomorphometry, micro‐computed tomography (micro‐CT) were performed to measure healing. At 4 weeks after fracture, maximum torque to failure, effective shear modulus, and effective shear stress were all significantly higher (p < 0.05) in rats treated with 0.25 mg/kg VAC–CaSO₄ as compared to carrier control rats. Histomorphometry found a 71% increase in percent cartilage matrix (p < 0.05) and a 64% decrease in percent mineralized tissue (p < 0.05) at 2 weeks after fracture in rats treated with 0.25 mg/kg of VAC–CaSO₄. Micro‐CT analyses at 4 weeks found a more organized callus structure and higher trending maximum connected z‐ray. fraction for VAC–CaSO₄ groups. Evaluation of radiographs and serial histological sections at 12 weeks did not show any evidence of ectopic bone formation. As compared to previous studies, CaSO₄ was an effective carrier for reducing the dose of VAC required to accelerate femoral fracture healing in rats. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:727–734, 2014.     

Retained periorbital and intracranial air-gun pellets causing sclopetaria and visual loss

Three healthy males presented on separate occasions to the emergency room at the King Khaled Eye Specialist Hospital (KKESH) after sustaining trauma by air-gun pellets. Clinical examination indicated sclopetaria in all the cases. The foreign bodies (air-gun pellets) were imbedded in different locations (subconjunctival, intraorbital, and intracranial). All cases resulted in a profound and permanent visual loss. The management of this traumatic injury is discussed and concurs with the published literature.     

Enhanced immune‐modulatory effects of thalidomide and dexamethasone co‐treatment on T cell subsets

Thalidomide (TM) has been reported to have anti‐cancer and anti‐inflammatory properties, and dexamethasone (DX) is known to reduce inflammation and inhibit production of inflammatory cytokines. Many studies have reported that combinatorial therapy with TM and DX is clinically used to treat multiple myeloma and lupus nephritis, but the mechanism responsible for its effects has not been elucidated. In this study, we determined that TM and DX co‐treatment had an enhanced immune‐modulatory effect on T cells through regulating the expression of co‐stimulatory molecules. Splenic naive T cells from C57BL/6 mice were sort‐purified and cultured for CD4⁺ T cell proliferation and regulatory T (Treg) cell conversion in the presence of TM and/or DX. Following incubation with the drugs, cells were collected and OX40, 4‐1BB, and glucocorticoid‐induced tumour necrosis factor receptor‐related protein (GITR) expression was quantified by flow cytometry. TM (1 or 10 μm ) decreased CD4⁺ T cell proliferation in a dose‐dependent manner, whereas TM/DX (0·1 or 1 nm ) co‐treatment further decreased proliferation. Treg cell populations were preserved following drug treatment. Furthermore, expression of co‐stimulatory molecules decreased upon TM/DX co‐treatment in effector T (Teff) cells and was preserved in Treg cells. Splenic CD4⁺ T cells isolated from TM‐ and DX‐treated mice exhibited the same patterns of Teff and Treg cell populations as observed in vitro. Considering the selective effect of TM on different T cell subsets, we suggest that TM may play an immunomodulatory role and that TM/DX combinatorial treatment could further enhance these immunomodulatory effects by regulating GITR, OX40, and 4‐1BB expression in CD4⁺ T cells.     

Plasma beta-thromboglobulin as a measure of platelet activity: Effect of risk factors and findings in ischemic heart disease and after acute myocardial infarction

The plasma concentration of beta-thromboglobulin (BTG), a platelet-specific protein released during platelet aggregation, is considered a sensitive marker of in vivo platelet activity. The mean plasma level in 133 asymptomatic individuals was 32.3 ± 1.1 ng/ml, and there was no difference between those with no risk factors (32.2 ± 1.2 ng/ml, n = 56), those who smoked (31.8 ± 1.8 ng/ml, n = 45), those with hyperlipidemia (32.8 ± 1.7 ng/ml, n = 15), and those exposed to both of these risk factors (34.1 ± 2.7 ng/ml, n = 17). The mean plasma BTG level in 104 patients with symptomatic ischemic heart disease was significantly elevated (40.9 ± 1.4 ng/ml, p < 0.01), but there was considerable overlap with normal levels. Although no difference was found between patients with no risk factors (38.1 ± 4.0 ng/ml, n = 13) and those with only 1 risk factor (37.0 ± 1.8 ng/ml, n = 44), patients with 2 or more risk factors had a significantly elevated plasma BTG level (45.2 ± 2.2 ng/ml, n = 47, p < 0.01). It is concluded that risk factors themselves do not increase platelet activity, but that patients with vascular disease have activated platelets that may contribute to the progression of the disease. Plasma BTG was also measured serially for 10 days in 29 patients after hospitalization with acute ischemic cardiac pain. Although the median plasma level was elevated above normal there were no acute changes in plasma BTG after either acute infarction (n = 22) or acute ischemia (n = 7), except in 2 patients in whom pericardial friction rubs developed. Thus, measurement of systemic plasma BTG did not detect platelet involvement in acute coronary occlusion or acute ischemia.     

Virtual Reality Rehabilitation With Functional Electrical Stimulation Improves Upper Extremity Function in Patients With Chronic Stroke: A Pilot Randomized Controlled Study

Objective

To compare virtual reality (VR) combined with functional electrical stimulation (FES) with cyclic FES for improving upper extremity function and health-related quality of life in patients with chronic stroke.

Cyclophosphamide inhibits the development of diabetes in the diabetes-prone BB rat

Abstract Aims/hypothesis. Cyclophosphamide has been shown to augment the diabetic process in NOD mouse and BB rat models of Type I (insulin-dependent) diabetes mellitus. Because cyclophosphamide has, however, been shown to increase immunoregulatory cell activity, we examined if cyclophosphamide treatment increases immunoregulatory cell activity and inhibits the diabetic process in BB rats. Methods. The development of insulitis and diabetes was explored in BB rats treated with saline and cyclophosphamide (60 to 175 mg/kg body weight). Subsets of spleen cells were assessed by flow cytometry and cytokine gene expression by RT-PCR. To determine if cyclophosphamide induces immunoregulatory cell activity, the development of diabetes was assessed in BB rats injected with spleen cells from rats treated with saline and cyclophosphamide. Results. All dosages of cyclophosphamide decreased the development of diabetes. The degree of insulitis was lower in pancreata from 55-day-old rats treated with cyclophosphamide than those from controls. Cyclophosphamide caused no alterations in the numbers of NK cells, T-cell subsets, or RT6.1⁺ T cells. The adoptive transfer of spleen cells from cyclophosphamide-treated rats to BB rats inhibited the development of diabetes. Cyclophosphamide treatment decreased IL-12, IL-1β, IL-2, IFN-γ and TNF-α gene expressions in mononuclear spleen cells but IL-4 gene expression increased. Conclusion/interpretation. These findings show that cyclophosphamide treatment decreases the development of diabetes by inhibiting the development of insulitis. This inhibitory action of cyclophosphamide on the diabetic process seems to be mediated by the induction of immunoregulatory cell activity. The suppression of cytokines that promote Th1 cell differentiation by cyclophosphamide treatment could also play a part in the diabetes sparing effect of cyclophosphamide. [Diabetologia (2000) 43: 986–994] Received: 10 December 1999 and in revised form: 13 April 2000     

Islet cell surface and lymphocyte antibodies often precede the spontaneous diabetes in the BB rat

Summary The diabetic syndrome of the BB rat shows many homologies with that of human insulin-dependent diabetes and evidence that the onset of the disease is associated with the presence of autoantibodies, including islet cell surface antibodies. In this study, sera were sampled serially from weaning to 157 days of age from 26 BB rats in two low-incidence litters, and 22 rats of three high-incidence litters. Clinical and metabolic variables were monitored concurrently with blood lymphocyte counts. Islet morphology was correlated at sacrifice. In the high-incidence litters, eight rats developed insulin-dependent diabetes, five impaired glucose tolerance, and the remaining nine all showed insulitis. In the low-incidence litters, only one animal showed impaired glucose tolerance and another insulitis. In the high-incidence litters 16 rats (73%) had islet cell surface antibodies compared with 4 out of 26 (15%) low-incidence controls (p<0.002). Antibodies reactive with Wistar rat spleen lymphocytes were present in all high-incidence rats compared with 19% (5 out of 26) among the control litters (p<0.002). Time courses of islet cell surface and lymphocyte antibody appearance and their peak values varied, but already at weaning the levels of both antibodies were increased among the high-incidence litter rats (p< 0.001). Islet cell surface and/or lymphocyte antibodies were therefore present in the majority of animals at an age where neither morphological nor metabolic evidence of the diabetic syndrome were yet detected. All rats that showed any form of the syndrome were lymphopenic. These findings suggest that BB rats have an abnormal immune response which predisposes to later development of insulin-dependent diabetes, often preceded by the presence of islet cell surface and/or lymphocyte antibodies.     

Transplantation of purified islet cells in diabetic BB rats

Summary The ability to prepare purified islet Beta-cell aggregates was used to examine the survival of this cell type after allotransplantation in diabetic BB rats. The aggregates were intraportally implanted in numbers that were previously found to correct a streptozotocin-induced diabetic state in syngeneic or allogeneic Brown Norway recipients. When the grafts were prepared from RT1^u/l donors, which shared the MHC-class I antigen with the BB recipients (RT1^u/u), their implant sites became diffusely infiltrated by inflammatory cells and their metabolic function was completely lost within 5 weeks. MHC-class I incompatible islet Beta-cell allografts (RT1^n/n) exhibited a longer survival, in particular when combined with other islet endocrine cells and/or when covered by a 5-week cyclosporin treatment. In the latter combination, 10 of 12 BB rat recipients remained normoglycaemic over the 10-week observation period, their liver implants presenting a comparable insulin reserve and similarly discrete mononuclear cell infiltration as streptozotocin-diabetic Brown Norway rats receiving this treatment. However, administration of cyclosporin to diabetic BB rats was associated with a morbidity that was not observed in drug-treated streptozotocin-diabetic Brown Norway animals or in untreated diabetic BB rats. It is concluded that MHC-incompatible islet Beta cells can induce a long-term normalization in diabetic BB rats provided that they are implanted under conditions which allow allograft acceptance. The standardized preparation of purified islet Beta-cell grafts can help assessing the conditions for successful transplantations in diabetes with an autoimmune origin.     

4–1BB signal stimulates the activation,expansion, and effector functions of γδ T cells in mice and humans

We show here that the expression of 4–1BB is rapidly induced in γδ T cells following antigenic stimulation in both mice and humans, and ligation of the newly acquired 4–1BB with an agonistic anti‐4–1BB augments cell division and cytokine production. We further demonstrate that γδ rather than αβ T cells protect mice from Listeria monocytogenes (LM) infection and 4–1BB stimulation enhances the γδ T‐cell activities in the acute phase of LM infection. IFN‐γ produced from γδ T cells was the major soluble factor regulating LM infection. Vγ1⁺ T cells were expanded in LM‐infected mice and 4–1BB signal triggered an exclusive expansion of Vγ1⁺ T cells and induced IFN‐γ in these Vγ1⁺ T cells. Similarly, 4–1BB was induced on human γδ T cells and shown to be fully functional. Combination treatment with human γδ T cells and anti‐hu4–1BB effectively protected against LM infection in human γδ T cell‐transferred NOD‐SCID mice. Taken together, these data provide evidence that the 4–1BB signal is an important regulator of γδ T cells and induces robust host defense against LM infection.