Treatment with trkC agonist antibodies delays disease progression in neuromuscular degeneration (nmd) mice

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a fatal autosomal recessive disorder seen in infants. It is characterized by lower motor neuron degeneration, progressive muscle paralysis and respiratory failure, for which no effective treatment exists. The phenotype of neuromuscular degeneration (nmd) mice closely resembles the human SMARD1. The identification of the mutated mouse gene in nmd mice, Ighmbp2, led to the discovery of mutations of the homologous gene in humans with SMARD1. We have studied the nmd mouse model with in vivo electrophysiological techniques and evaluated the efficacy of Mab2256, a monoclonal antibody with agonist effect on the tyrosine kinase receptor C, trkC, on disease progression in nmd mice. Treatment with Mab2256 resulted in a significant but transient improvement of muscle strength in nmd mice, as well as normalization of the neuromuscular depression during high-frequency nerve stimulation. These results suggest the potential of using monoclonal agonist antibodies for neurotrophin receptors in lower motor neuron diseases such as SMARD1.     

Measurement of talent in judo using a unique, judo-specific ability test

AIM: Coaches of young athletes at early phases of development often use batteries of tests in order to obtain information that will be helpful in predicting their future success. However, little scientific inquiry has been conducted on the relevance of the testing process to the final selection and success of young prospects. The purpose of this study was to examine the benefits of a unique judo-specific ability test in early phases of talent development and selection. METHODS: Ten judokas (12-15 years of age) underwent assessment of general ability and specific judo ability 3 times during 1994 and 1995, at about 6-month intervals. The general ability test included: sit-ups, push-ups, and side-to-side jumps. The specific judo ability test was comprised of 10 stations in which the judokas performed physical ability and skill tasks. Following the 12-month training program the judokas were ranked by the 2 national judo coaches. Eight years after the beginning of the training program, the judokas were ranked once again by the national coaches. RESULTS: Data analysis revealed that the specific judo ability test did not correlate with either the 1995 or with the 2003 ranking. CONCLUSIONS: Because the unique judo-specific ability test was not found to be sensitive enough to accurately measure talent, it is suggested that future studies investigate the usefulness of tests reflecting a more open-skill environment.     

The prognostic virtue of inflammatory markers during late-onset sepsis in preterm infants

AIM: Late-onset sepsis (occurring after the first three days of life) is a serious complication in preterm infants. In order to assess the possible prognostic virtues of the acute phase inflammatory response in the disease, we compared the inflammatory response of preterm infants who died within 72 hours (h) (fulminant sepsis) to infants who recovered from the disease (non-fulminant sepsis). METHODS: Of 42 preterm infants that were evaluated: 10 had fulminant sepsis and 32 non-fulminant sepsis. Acute phase inflammatory response markers-C-reactive protein (CRP), serum amyloid A (SAA), interleukin (IL)-6 levels and white blood cell (WBC) counts were measured at the first suspicion of LOS and after 8, 24 and 48 h. RESULTS: Small for gestational age (SGA) infants who were treated with fewer days of antibiotics characterized the fulminant sepsis group. The initial high levels of inflammatory markers were similar in both groups, but as early as 8 h after onset significantly lower levels of SAA, CRP and WBC counts were documented in the fulminant sepsis group. The inflammatory response remained low at 24 and 48 h in the fulminant sepsis group, while in the survivors, significantly increased inflammatory markers were measured. Decreases in the levels of the inflammatory markers preceded episodes of metabolic acidosis and arterial hypotension that were more common in the fulminant sepsis group. Infant mortality correlated inversely with SAA levels at 8 h and with CRP and WBC counts at 24 h after onset. CONCLUSION: SAA, CRP and WBC counts can be used as prognostic markers in LOS in preterm infants, with SAA being the earliest prognostic marker.     

Mechanism of action of glatiramer acetate in multiple sclerosis and its potential for the development of new applications

Glatiramer acetate (GA, Copaxone, Copolymer 1) is an approved drug for the treatment of multiple sclerosis and is highly effective in the suppression of experimental autoimmune encephalomyelitis in various species. The mode of action of GA is by initial strong promiscuous binding to MHC molecules and consequent competition with various myelin antigens for their presentation to T cells. A further aspect of its action is potent induction of specific suppressor cells of the T helper 2 (Th2) type that migrate to the brain and lead to in situ bystander suppression. Furthermore, the GA-specific cells in the brain express the antiinflammatory cytokines IL-10 and transforming growth factor beta, in addition to brain-derived neurotrophic factor, whereas they do not express IFN-gamma. Based on this immunomodulatory mode of action, we explored the potential of GA for two other applications: prevention of graft rejection and amelioration of inflammatory bowel diseases. GA was effective in amelioration of graft rejection in two systems by prolongation of skin graft survival and inhibition of functional deterioration of thyroid grafts, across minor and major histocompatibility barriers. In all transplantation systems GA treatment inhibited the detrimental secretion of Th1 inflammatory cytokines and induced beneficial Th2/3 antiinflammatory response. GA was effective also in combination with low-dose immunosuppressive drugs. Inflammatory bowel diseases are characterized by detrimental imbalanced proinflammatory immune reactivity in the gut. GA significantly suppressed the various manifestations of trinitrobenzene sulfonic acid-induced colitis, including mortality, weight loss, and macroscopic and microscopic colonic damage. GA suppressed local lymphocyte proliferations and tumor necrosis factor alpha detrimental secretion but induced transforming growth factor beta, thus confirming the involvement of Th1 to Th2 shift in GA mode of action.     

CXCR4 regulates migration and development of human acute myelogenous leukemia stem cells in transplanted NOD/SCID mice

The chemokine stromal cell-derived factor-1 (SDF-1) and its receptor CXCR4 participate in the retention of normal hematopoietic stem cells within the bone marrow (BM) and their release into the circulation. Homing and engraftment of human stem cells in immunodeficient mice are dependent on cell surface CXCR4 expression and the production of BM SDF-1, which acts also as a survival factor for both human and murine stem cells. However, the role of SDF-1/CXCR4 interactions in the control of human acute myelogenous leukemia (AML) cell trafficking and disease progression is poorly understood. In this study, we report that although some AML cells do not express surface CXCR4, all AML cells tested express internal CXCR4 and SDF-1. Culture of AML cells with SDF-1 promoted their survival, whereas addition of neutralizing CXCR4 antibodies, SDF-1 antibodies, or AMD3100 significantly decreased it. Pretreatment of primary human AML cells with neutralizing CXCR4 antibodies blocked their homing into the BM and spleen of transplanted NOD/SCID/B2m(null) mice. Furthermore, weekly administrations of antihuman CXCR4 to mice previously engrafted with primary AML cells led to a dramatic decrease in the levels of human AML cells in the BM, blood, and spleen in a dose- and time-dependent manner. Interestingly, the same treatment did not affect significantly the levels of normal human progenitors engrafted into NOD/SCID mice. Taken together, our findings demonstrated the importance of the SDF-1/CXCR4 axis in the regulation of in vivo motility and development of human AML stem cells and identified CXCR4 neutralization as a potential treatment for AML.     

Cyclophosphamide modulates CD4+ T cells into a T helper type 2 phenotype and reverses increased IFN-gamma production of CD8+ T cells in secondary progressive multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system considered to be mediated by T helper type-1 cells. Several agents have been found to modify the disease course of MS, including interferon-beta1 (IFN-beta1), glatiramer acetate mitoxantrone. We have employed pulse therapy with cyclophosphamide in a selected group of patients with actively progressive disease. Chemokine receptors have been found to differentiate between polarized T helper type-1 (Th1) and type-2 (Th2) lymphocytes. The chemokine receptors CCR5 and CXCR3 are expressed primarily on Th1 cells and CCR3, CCR4 and CCR8 on Th2 cells. Previous studies of the expression of chemokine receptors in MS have shown that active MS plaques are infiltrated by CCR5(+) and CXCR3(+) T cells. Some of these T cells may express both CCR5 and CXCR3. These T cells are major producers of IFN-gamma, which worsens the clinical condition of patients with MS. We previously found that patients with MS had a high proportion of CXCR3(+) T cells and that those with chronic progressive MS had a high proportion of CCR5(+) T cells in their peripheral blood. We report here that in patients with secondary progressive MS, cyclophosphamide induces a marked increase in the percentage of CCR4(+) T cells that produce high levels of IL-4 and reverses the increase in the percentages of IFN-gamma-producing CCR5(+) and CXCR3(+) CD8(+) T cells. Furthermore, therapy with cyclophosphamide increases IL-4-producing CD4(+) T cells and reverses the increase in IFN-gamma-producing CD8(+) T cells. Our study shows that cyclophosphamide has immunomodulatory properties besides its suppressive effects, and that chemokine receptors can be important tools both for understanding the immune dysregulation in MS and for monitoring response to therapy.     

Urinary tract infection in very low birth weight preterm infants

BACKGROUND: The prevalence of urinary tract infection (UTI) in preterm neonates ranges between 4 and 25%. The need for a radiologic investigation has not yet been established in very low birth weight premature newborns (<1500 g birth weight). PATIENTS AND METHODS: For an 11-year period (1990 to 2001), medical records of 62 very low birth weight premature infants admitted to a Level III neonatal intensive care unit and who developed UTI were reviewed retrospectively. Results of renal ultrasound and voiding cystourethrograms were compared between extremely low birth weight infants (birth weight, <1000 g) (Group A, Patient 34) and premature infants with birth weight between 1001 and 1500 g (Group B, Patient 28). RESULTS: UTI was more common in Group A (12.2%) than in Group B (5.7%) infants. Renal ultrasound detected mild renal pelvic dilatation (unilateral or bilateral) in 9 infants in Group A (26%) and in 1 infant in Group B (3.5%). Voiding cystourethrograms were performed in 26 of 34 (76%) infants in Group A and in 17 of the 28 (61%) premature infants in Group B. Vesicourethral reflux (VUR) was observed in 6 infants, 2 in group A (7.7%) and 4 in Group B (23%). CONCLUSIONS: We found that the rate of VUR was lower in very low birth weight premature newborns than that reported in the medical literature among term newborns who developed UTI. VUR was less frequent in extremely low birth weight infants who developed UTI than in infants weighing 1001 to 1500 g.     

Neonatologists are using much less dexamethasone

Two historical cohorts (1993-1994 and 2001) of preterm infants ventilated for respiratory distress syndrome were compared. Dexamethasone administration fell from 22% to 6%. Chronic lung disease in survivors rose slightly from 13% to 17%, and mortality fell from 21% to 15% (other causes). The effect of restriction of dexamethasone use on chronic lung disease and mortality remains to be seen.     

The pathophysiology of the fetus of the diabetic mother

The metabolic processes that are responsible for the pathophysiology of the fetus of the diabetic mother have been elucidated in recent years and include maternal hyperglycinemia, fetal hyperglycinemia, fetal hyperinsulinemia, and increased levels of maternal, placental, and fetal insulin-like growth factors. Counter-regulatory mechanisms, such as insulin-like growth factors binding proteins and leptin also play a role. The fetal hypermetabolic state leads to increased somatic growth, obesity, and metabolic disturbances with short- and long-term consequences.     

CT assessment of bone marrow transplant patients with rhinocerebral aspergillosis

PURPOSE: Invasive rhinocerebral aspergillosis is a hazardous complication of bone marrow transplantation. A study was conducted to describe the computed tomography (CT) features of this disease. MATERIALS AND METHODS: Charts and CT scans of bone marrow transplant patients with invasive rhinocerebral aspergillosis were reviewed. The diagnosis was confirmed by otolaryngologic examination and biopsy of suspected lesions. Sinus CT scans were conducted without contrast material. They were repeated with contrast if intracranial or intraorbital extension was suspected. CT scans were correlated with physical examination, history of disease, and histology. RESULTS: Of 1,013 bone marrow transplantations carried out over a 10-year period, 21 patients (2.07%) developed invasive rhinocerebral aspergillosis. In most cases the infection was unilateral. Air-fluid levels and calcifications were rarely encountered. Mucosal thickening, soft tissue hyperdense masses in the nasal cavity and/or sinuses, and clear (uninvolved) ethmoid cells amid diseased cells, were significant CT features that characterized invasive fungal infection. Opacification of the sinus represented extensive disease with tissue necrosis. When bone destruction was encountered, fulminant infection was already present, usually with significant orbital and/or brain invasion. CONCLUSIONS: When correlated with clinical findings and histologic results, the above CT features can help identify early infection so that appropriate medical and surgical treatment can be instituted.