Acute molecular perturbation of inducible nitric oxide synthase with an antisense approach enhances neuronal preservation and functional recovery after contusive spinal cord injury

Abstract Inducible nitric oxide synthase (iNOS) is a key mediator of inflammation and oxidative stress produced during pathological conditions, including neurodegenerative diseases and central nervous system (CNS) injury. iNOS is responsible for the formation of high levels of nitric oxide (NO). The production of highly reactive and cytotoxic NO species, such as peroxynitrite, plays an important role in secondary tissue damage. We have previously demonstrated that acute administration of iNOS antisense oligonucleotides (ASOs) 3?h after moderate contusive spinal cord injury (SCI) potently inhibits iNOS-mediated increases in NO levels, leading to reduced blood-spinal cord barrier permeability, decreased neutrophil accumulation, and less neuronal cell death. In the current study we investigated if iNOS ASOs could also provide long-term (10-week) histological and behavioral improvements after moderate thoracic T8 contusive SCI. Adult rats were randomly assigned to three groups (n=10/group): SCI alone, SCI and mixed base control oligonucleotides (MBOs), or SCI and iNOS ASOs (200?nM). Oligonucleotides were administered by spinal superfusion 3?h after injury. Behavioral analysis (Basso-Beattie-Bresnahan [BBB] score and subscore) was employed weekly for 10 weeks post-SCI. Although animals treated with iNOS ASOs demonstrated no significant differences in BBB scores compared to controls, subscore analysis revealed a significant improvement in foot positioning, trunk stability, and tail clearance. Histologically, while no gross improvement in preserved white and gray matter was observed, greater numbers of surviving neurons were present adjacent to the lesion site in iNOS ASO-treated animals than controls. These results support the effectiveness of targeting iNOS acutely as a therapeutic approach after SCI.     

Leg ulcers associated with Klinefelter's syndrome: a case report and review of the literature

We present the case of a young man with type II diabetes, stage III chronic kidney disease, hypertension, obstructive sleep apnea and diabetes who presented to the Georgetown University Hospital Center for Wound Healing with refractory lower extremity ulcers. Autoimmune work-up was negative. However, chromosome analysis showed a genetic variant of Klinefelter's syndrome (48 XXYY). Lower extremity ulceration is a recognised complication of Klinefelter's syndrome. The pathogenesis of ulcers in this endocrinopathy is unclear, but associations with abnormalities of fibrinolysis and prothrombotic states are reported. This case emphasises the importance of considering Klinefelter's syndrome in the differential diagnosis of a sterile male patient with non healing lower extremity ulcers.     

Critical role for the mitochondrial permeability transition pore and cyclophilin D in platelet activation and thrombosis

Many of the cellular responses that occur in activated platelets resemble events that take place following activation of cell-death pathways in nucleated cells. We tested the hypothesis that formation of the mitochondrial permeability transition pore (MPTP), a key signaling event during cell death, also plays a critical role in platelet activation. Stimulation of murine platelets with thrombin plus the glycoprotein VI agonist convulxin resulted in a rapid loss of mitochondrial transmembrane potential (Deltapsi(m)) in a subpopulation of activated platelets. In the absence of cyclophilin D (CypD), an essential regulator of MPTP formation, murine platelet activation responses were altered. CypD-deficient platelets exhibited defects in phosphatidylserine externalization, high-level surface fibrinogen retention, membrane vesiculation, and procoagulant activity. Also, in CypD-deficient platelet-rich plasma, clot retraction was altered. Stimulation with thrombin plus H(2)O(2), a known activator of MPTP formation, also increased high-level surface fibrinogen retention, phosphatidylserine externalization, and platelet procoagulant activity in a CypD-dependent manner. In a model of carotid artery photochemical injury, thrombosis was markedly accelerated in CypD-deficient mice. These results implicate CypD and the MPTP as critical regulators of platelet activation and suggest a novel CypD-dependent negative-feedback mechanism regulating arterial thrombosis.     

A significance of additional chromosomal aberrations and other variables on post transplantation outcome of patients with CML

Chronic myeloic leukemia (CML) is a malignant disease of hematopoietic stem cell characterized by the bcr/abl gene rearrangement. Allogeneic transplantation of stem cells (SCT) is a routinely used treatment method of patients with this diagnosis and remains the only curative mode of treatment. From January 1990 to December 2002, 78 patients with CML underwent allogeneic transplantation and were examined at the Department of Genetics in the National Cancer Institute in Bratislava. Using conventional cytogenetic and FISH 6 patients (7.7%) showed additional chromosomal changes before SCT. These patients had statistically worse post transplantation prognosis compared to the patients without additional changes before SCT (mean survival in month+/-standard error (58.08 (+/-6.70) vs. 5.17 (+/-0.98), p-value=0.001), patient mortality (67% vs. 31%)). In addition five other variables were evaluated for transplant outcome, namely, patient's age at the time of transplantation, sibling or non-sibling donor, higher than 1st chronic phase CML, time from diagnosis to transplantation and sex of donor and recipient. Only the comparison of HLA-identical sibling transplantation to unrelated donor transplantation was statistically significant (mean survival in month- 56.6 (+/-7.2) vs. 13 (+/-0.0), patient mortality 31% vs. 67%).     

Prevalence of Congenital Heart Diseases in Oral Cleft Patients

To establish the prevalence of congenital heart diseases (CHDs) in cleft patients, the type of cleft and the presence of a syndrome were coded in 220 patients. A Doppler echocardiogram with color-flow mapping (DE) was obtained in all patients. Mean age was 112.0 ± 101.2 months (range, 1–576 months), and 56.8% (125) were males. Cleft lip and palate occurred in 144 patients (65.5%), cleft lip in 40 (18.2%), and cleft palate in 36 (16.4%). Cleft palates were more frequent among females. Twenty-four CHDs were diagnosed in 21 of 220 patients (9.5%): 7 mitral valve prolapses, 6 atrial septal defects, 4 patent ductus arteriosus, 3 ventricular septal defects, 2 cases of tetralogy of Fallot, 1 pulmonary stenosis, and 1 bicuspid aortic valve. The presence of CHD did not correlate with the type of clef. Syndromes occurred in 28 patients (12.7%), and this association was higher among patients with a cleft palate.     

Changes in the functioning of the electromechanical connection during tetanic contraction

The functioning of the electromechanical connection during tetanic contraction in frog skeletal muscle was studied. Analysis using caffeine, calcium-free medium, the ryanodine receptor blocker dantrolene, and the Ca-ATPase inhibitor thapsigargin showed that the initial increase in tetanus, as in twitch contractions, did not require the presence of calcium ions in the surrounding medium, which is in agreement with published data. Contraction was accompanied by activation of potential-dependent release of calcium from the sarcoplasmic reticulum. In contrast, the secondary rise phase and/or the duration of the tetanus plateau were critically dependent on the present of Ca²⁺ in the surrounding medium. Given that contraction in this situation was inhibited by dantrolene, activation of prolonged contraction was also mediated by calcium released from the sarcoplasmic reticulum, though ryanodine receptors were now activated not by changes in the membrane potential but by the influx of external calcium. Thus, external calcium plays a significant role in the formation of prolonged contractile responses, providing for longer-lasting maintenance of power in contracted muscles. __________ Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 91, No. 11, pp. 1288–1298, November 2005.     

Calcaneal adduction and eversion are coupled to talus and tibial rotation

The purpose of this study was to quantify isolated coupling mechanisms of calcaneal adduction/abduction and calcaneal eversion/inversion to proximal bones in vitro. The in vitro approach is necessary because in vivo both movements appear together, making it impossible to determine the extent of their individual contribution to overall ankle joint coupling. Eight fresh frozen foot‐leg specimens were tested. Data describing bone orientation and coupling mechanisms between segments were obtained using bone pin marker triads. The bone movement was described in a global coordinate system to examine the coupling between the calcaneus, talus and tibia. The strength of coupling was determined by means of the slope of a linear least squares fit to an angle–angle plot. The coupling coefficients in the present study indicate that not only calcaneal eversion/inversion (coupling coefficient: 0.68 ± 0.15) but to an even greater extent calcaneal adduction/abduction (coupling coefficient: 0.99 ± 0.10) was transferred into talus and tibial rotation, highlighting the relevance of calcaneal adduction for the overall ankle joint coupling. The results of this study present the possibility that controlling calcaneal adduction/abduction can affect talus and tibial rotation and therefore the possible genesis of overuse knee injuries.