Does Trochanteric Transfer Eliminate the Trendelenburg Sign in Adults?

Premature closure of the proximal femoral growth plate results in coxa brevis, which usually is associated with insufficiency of the hip abductors. Distal and lateral transfer of the greater trochanter sometimes is recommended to correct this problem. Most of what is known arises from studies of children and adolescents. We asked whether this procedure in adults with coxa brevis would eliminate hip abductor insufficiency and would improve their hip function based on the Harris hip score (HHS). We prospectively followed 11 patients, aged 19 to 55 years (mean, 40 years) who had distal and lateral trochanteric transfer. All patients had pain and a positive Trendelenburg test before surgery. This test was performed at the latest followup by three observers and the interobserver reliability was determined by the kappa coefficient. The HHS was obtained before surgery and at the latest followup. The minimum followup was 25 months (mean, 52 months; range, 25-77 months). Insufficiency of the hip abductors was eliminated in seven (according to two observers) and eight (according to one observer) of the 11 patients after surgery; the kappa coefficient ranged from 0.79 to 1.0. The mean HHS improved from 64 points preoperatively to 76 points at the final followup. The two patients with preexisting severe osteoarthritis of the hip had the worst final scores and persisted with a positive Trendelenburg test at the final followup. Distal and lateral transfer of the greater trochanter can eliminate insufficiency of the hip abductors and improve joint function in adult patients with coxa brevis and we believe should be considered for patients without severe osteoarthritis of the hip. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Crotamine toxicity and efficacy in mouse models of melanoma

Objectives: Selective anticancer cell activity for both cell-penetrating and cationic antimicrobial peptides has previously been reported. As crotamine possesses activities similar to both of these, this study investigates crotamine`s anticancer toxicity in vitro and in vivo. Research design and methods: In vitro cancer cell viability was evaluated after treatment with 1 and 5 mu g/ml of crotamine. In vivo crotamine cytotoxic effects in C57Bl/6J mice bearing B16-F10 primary cutaneous melanoma were tested, with two groups each containing 35 mice. The crotamine-treated group received 1 mu g/day of crotamine per animal, subcutaneously which was well tolerated; the untreated group received a placebo. Results: Crotamine at 5 mu g/ml was lethal to B16-F10, Mia PaCa-2 and SK-Mel-28 cells and inoffensive to normal cells. In vivo crotamine treatment over 21 days significantly delayed tumor implantation, inhibited tumor growth and prolonged the lifespan of the mice. Mice in the crotamine-treated group survived at significantly higher rates (n = 30/35) than those in the untreated group (n = 7/35) (significance calculated with the Kaplan-Meier estimator). The average tumor weight in the untreated group was 4.60 g but was only about 0.27 g in the crotamine-treated mice, if detectable. Conclusions: These data warrant further exploration of crotamine as a tumor inhibition compound.

Rationale and design of a randomized placebo-controlled trial assessing the effects of etiologic treatment in Chagas` cardiomyopathy: The BENznidazole Evaluation For Interrupting Trypanosomiasis (BENEFIT)

Background Benznidazole is effective for treating acute and chronic (recently acquired) Tryponosoma cruzi infection (Chagas` disease). Recent data indicate that parasite persistence plays a pivotal role in the pathogenesis of chronic Chagas` cardiomyopathy. However, the efficacy of trypanocidal therapy in preventing clinical complications in patients with preexisting cardiac disease is unknown. Study Design BENEFIT is a multicenter, randomized, double-blind, placebo-controlled clinical trial of 3,000 patients with Chagas` cardiomyopathy in Latin America. Patients are randomized to receive benznidazole (5 mg/kg per day) or matched placebo, for 60 days. The primary outcome is the composite of death; resuscitated cardiac arrest; sustained ventricular tachycardia; insertion of pacemaker or cardiac defibrillator; cardiac transplantation; and development of new heart failure, stroke, or systemic or pulmonary thromboembolic events. The average follow-up time will be 5 years, and the trial has a 90% power to detect a 25% relative risk reduction. The BENEFIT program also comprises a substudy evaluating the effects of benznidazole on parasite clearance and an echo substudy exploring the impact of etiologic treatment on left ventricular function. Recruitment started in November 2004, and >1,000 patients have been enrolled in 35 centers from Argentina, Brazil, and Colombia to date. Conclusion This is the largest trial yet conducted in Chagas` disease. BENEFIT will clarify the role of trypanocidal therapy in preventing cardiac disease progression and death.

Modulation of respiratory responses to chemoreflex activation by L-glutamate and ATP in the rostral ventrolateral medulla of awake rats

Moraes DJA, Bonagamba LGH, Zoccal DB, Machado BH. Modulation of respiratory responses to chemoreflex activation by L-glutamate and ATP in the rostral ventrolateral medulla of awake rats. Am J Physiol Regul Integr Comp Physiol 300: R1476-R1486, 2011. First published March 16, 2011; doi:10.1152/ajpregu.00825.2010.-Presympathetic neurons in the different anteroposterior aspects of rostral ventrolateral medulla (RVLM) are colocalized with expiratory [Botzinger complex (BotC)] and inspiratory [pre-Botzinger complex (pre-BotC)] neurons of ventral respiratory column (VRC), suggesting that this region integrates the cardiovascular and respiratory chemoreflex responses. In the present study, we evaluated in different anteroposterior aspects of RVLM of awake rats the role of ionotropic glutamate and purinergic receptors on cardiorespiratory responses to chemoreflex activation. The bilateral ionotropic glutamate receptors antagonism with kynurenic acid (KYN) (8 nmol/50 nl) in the rostral aspect of RVLM (RVLM/BotC) enhanced the tachypneic (120 +/- 9 vs. 180 +/- 9 cpm; P < 0.01) and attenuated the pressor response (55 +/- 2 vs. 15 +/- 1 mmHg; P < 0.001) to chemoreflex activation (n = 7). On the other hand, bilateral microinjection of KYN into the caudal aspect of RVLM (RVLM/pre-BotC) caused a respiratory arrest in four awake rats used in the present study. Bilateral P2X receptors antagonism with PPADS (0.25 nmol/50 nl) in the RVLM/BotC reduced chemoreflex tachypneic response (127 +/- 6 vs. 70 +/- 5 cpm; P < 0.001; n = 6), but did not change the chemoreflex pressor response. In addition, PPADS into the RVLM/BtC attenuated the enhancement of the tachypneic response to chemoreflex activation elicited by previous microinjections of KYN into the same subregion (188 +/- 2 vs. 157 +/- 3 cpm; P < 0.05; n = 5). Our findings indicate that: 1) L-glutamate, but not ATP, in the RVLM/BtC is required for pressor response to peripheral chemoreflex and 2) both transmitters in the RVLM/BtC are required for the processing of the ventilatory response to peripheral chemoreflex activation in awake rats.

Comparisons of the release of vasodilator substances from left and right cardiac chambers of the isolated perfused rabbit heart: Implications for intraventricular thrombus formation

Prostacyclin (PgI(2)) and endothelium-derived nitric oxide (EDNO) are produced by the arterial and venous endothelium. In addition to their vasodilator action on vascular smooth muscle, both act together to inhibit platelet aggregation and promote platelet disaggregation. EDNO also inhibits platelet adhesion to the endothelium. EDNO and PgI(2) have been shown to be released from the cultured endocardial cells. In this study, we examined the release of vasoactive substances from the intact endocardium by using isolated rabbit hearts perfused with physiological salt solution (95% O(2)/5% CO(2), T = 37 degrees C). The right and left cardiac chambers were perfused through separate constant-flow perfusion loops (physiological salt solution, 8 ml min(-1)). Effluent from left and right cardiac, separately, was bioassayed on canine coronary artery smooth muscle, which had been contracted with prostaglandin F(2 alpha_)(2 x 10(-6) M) and no change in tension was exhibit. However, addition of calcium ionophore A23187 (10(-6) M) to the cardiac chambers` perfusion line induced vasodilation of the bioassay coronary ring, 61.4 +/- 7.4% versus 70.49 +/- 6.1% of initial prostaglandin F(2 alpha) contraction for the left and right cardiac chambers perfusate, respectively (mean +/- SEM, n = 10, p > 0.05). Production of vasodilator was blocked totally in the left heart but, only partially blocked in the right heart by adding indomethacin (10(-5) M) to the perfusate, respectively, 95.2 +/- 2.2% versus 41.5 +/- 4.8% (mean +/- SEM, n = 10, p < 0.05). 6-Keto prostaglandin F(1 alpha), measured in the endocardial superfusion effluent was also higher for the left cardiac chambers than for the right at the time of stimulation with the A23187, respectively, 25385.88 +/- 5495 pg/ml (n = 8) versus 13,132.45 +/- 1839.82 pg/ml (n = 8), (p < 0.05). These results showed that cyclooxygenase pathway plays major role in generating vasoactive substances for the left cardiac chamber endocardium; while it is not the main pathway for the right ventricular endocardium at which EDNO and PgI(2) Could act together and potentiate their antithrombogenic activities in isolated perfused rabbit heart. This may be an explanation for the intraventricular thrombus mostly seen in left ventricle rather than in right ventricle as a complication of myocardial infarction. (C) 2009 Elsevier Inc. All rights reserved.

Blood Cardioplegia with N-Acetylcysteine May Reduce Coronary Endothelial Activation and Myocardial Oxidative Stress

Objectives: The aim of this prospective study was to compare the efficacy of intermittent antegrade blood cardioplegia with or without n-acetylcysteine (NAC) in reducing myocardial oxidative stress and coronary endothelial activation. Methods: Twenty patients undergoing elective isolated coronary artery bypass graft surgery were randomly assigned to receive intermittent antegrade blood cardioplegia (32 degrees C-34 degrees C) with (NAC group) or without (control group) 300 mg of NAC. For these 2 groups we compared clinical outcome, hemodynamic evolution, systemic plasmatic levels of troponin I, and plasma concentrations of malondialdehyde (MDA) and soluble vascular adhesion molecule 1 (sVCAM-1) from coronary sinus blood samples. Results: Patient demographic characteristics and operative and postoperative data findings in both groups were similar. There was no hospital mortality. Comparing the plasma levels of MDA 10 min after the aortic cross-clamping and of sVCAM-1 30 min after the aortic cross-clamping period with the levels obtained before the aortic clamping period, we observed increases of both markers, but the increase was significant only in the control group (P=.039 and P=.064 for MDA; P=.004 and P=.064 for sVCAM- 1). In both groups there was a significant increase of the systemic serum levels of troponin I compared with the levels observed before cardiopulmonary bypass (P<.001), but the differences between the groups were not significant (P=.570). Conclusions: Our investigation showed that NAC as an additive to blood cardioplegia in patients undergoing on-pump coronary artery bypass graft surgery may reduce oxidative stress and the resultant coronary endothelial activation.

Effect of culture media on porcine embryos produced by in vitro fertilization or parthenogenetic activation after oocyte maturation with cycloheximide

This study evaluated the effects of reversible meiotic inhibition and different culture media (PZM3 or NCSU23) on production of porcine embryos by either in vitro fertilization (IVF) or parthenogenetic activation (PA). Oocytes from abattoir-derived ovaries were allocated into two groups for maturation: CHX (5 mu g/ml cycloheximide for 10 h) or Control (no CHX). The percentage of metaphase II (MII) oocytes was determined at 36, 40 or 44 h of in vitro maturation. For IVF and PA, denuded oocytes were fertilized with purified sperm for 6 h or activated by electric stimuli. Zygotes were then subdivided into two culture groups: NCSU23 or PZM3. No effect of treatment with CHX and culture media was observed on cleavage (D3) and blastocyst (D7) rates in IVF and PA groups. There are no differences of quality or development rates between IVF-derived embryos cultured in NCSU23 or PZM3. However, we observed high quality PA embryos in PZM3 compared with NCSU23. Maturation arrest with CHX decreased the average blastocyst cell number in IVF while it was increased in PA embryos. As older oocytes are more effectively activated, CHX-blocked oocytes reached the mature stage faster than the control group. In conclusion, the CHX treatment for 10 h, followed by oocyte maturation for 40 h, is an efficient protocol to produce high quality parthenote embryos, especially when they are cultured in PZM3. However, this protocol is not satisfactory for IVF embryos production. In this case, a shorter maturation period could provide better embryo quality.

Mineral trioxide aggregate as an alternative treatment for intruded permanent teeth with root resorption and incomplete apex formation

A case of extensive crown fracture associated with intrusion of the permanent maxillary central incisors in an 8-year-old boy is reported. The treatment of both injured teeth included attempts of apexification and arrest of root resorption with calcium hydroxide. After 8 months of the trauma, there was no calcified barrier formation in the apex. Mineral trioxide aggregate (MTA) was then used as a filling material. At 15-month follow up, the teeth were asymptomatic and correctly sealed, the external inflammatory root resorption had stopped, and the radiolucent image had disappeared, which meant the initial healing of the periapical lesion. MTA may be considered as an alternative option for the treatment of traumatized and immature permanent teeth.

Cytotoxicity of resin-based light-cured liners

Purpose: To evaluate the cytotoxic effects of resin-based light-cured liners on culture of pulp cells. Methods: Discs measuring 4 mill in diameter and 2 mm thick were fabricated from TheraCal (TCMTA), Vitrebond (VIT), and Ultrablend Plus (UBP). These specimens were immersed in serum-free culture medium (DMEM) for 24 hours or 7 days to produce the extracts. After incubating the pulp cells for 72 hours, the extracts were applied on the cells and the cytotoxic effects were determined based on the cell metabolism (MTT), total protein expression and cell morphology (SEM). In the control group, fresh DMEM was used. Data from MTT analysis and protein expression were submitted to Kruskal-Wallis and Mann-Whitney tests at the preset level of significance of 5%. Results: When in contact with the 24-hour extract, TCMTA, VIT, and UBP decreased the cell metabolism by 31.5%, 73.5% and 71.0%, respectively. The total protein expressed by the cells in contact with VIT and UBP was lower than TCMTA and DMEM (Mann-Whitney, P< 0.05). When in contact with the 7-day extract, TCMTA, VIT, and UBP decreased the metabolic activity by 45.9%, 77.1% and 64.4%, respectively. All the liners expressed statistically lower amounts of proteins when compared to the control. A reduction in the number of cells was observed for all liners. The remaining cells from TCMTA group resembled those from the control group while for VIT and UBP the cells presented significant morphological alterations. (Ani J Dent 2009;22:137-142).

A Combined Regenerative Approach for the Treatment of Aggressive Periodontitis: Long-term Follow-up of a Familial Case

This article reports the longitudinal follow-up of a familial case of aggressive periodontitis treated by a combined regenerative approach that consisted of root conditioning, bone grafting, and membrane positioning. Treatment resulted in attachment level gain, reduction of probing depth, absence of bleeding on probing, and complete bone filling of the defect. The short-term results obtained after surgery were maintained after 6 years, suggesting that the combined regenerative approach is able to completely arrest the disease with long-term stability. (Int J Periodontics Restorative Dent 2009; 29: 69-79.)

gamma-Radiation induces apoptosis via sarcoplasmatic reticulum in guinea pig ileum smooth muscle cells

We investigated the effects of gamma-radiation on cells isolated from the longitudinal smooth muscle layer of the guinea pig ileum, a relatively radioresistant tissue. Single doses (up to 50 Gy) reduced the amount of sarcoplasmatic reticulum and condensed the myofibrils, as shown by electron microscopy 3 days post-irradiation. After that, contractility of smooth muscle strips was reduced. Ca(2+) handling was altered after irradiation, as shown in fura-2 loaded cells, with elevated basal intracellular Ca(2+), reduced amount of intrareticular Ca(2+), and reduced capacitive Ca(2+) entry. Radiation also induced apoptosis, judged from flow cytometry of cells loaded with proprium iodide. Electron microscopy showed that radiation caused condensation of chromatin in dense masses around the nuclear envelope, the presence of apoptotic bodies, fragmentation of the nucleus, detachment of cells from their neighbors, and reductions in cell volume. Radiation also caused activation of caspase 12. Apoptosis was reduced by the administration of the caspase inhibitor Z-Val-Ala-Asp-fluoromethyl-ketone methyl ester (Z-VAD-FIVIK) during the 3 day period after irradiation, and by the chelator of intracellular Ca(2+), 1,2-bis(o-aminophenoxy)ethane-N,N,N`,N`-tetraacetic acid (BAPTA), from 1 h before until 2 h after irradiation. BAPTA also reduced the effects of radiation on contractility, basal intracellular Ca(2+), amount of intrareticular Ca(2+), capacitative Ca(2+) entry, and apoptosis. In conclusion, the effects of gamma radiation on contractility, Ca(2+) handling, and apoptosis appear due to a toxic action of intracellular Ca(2+). Ca(2+)-induced damage to the sarcoplasmatic reticulum seems a key event in impaired Ca(2+) handling and apoptosis induced by gamma-radiation. (c) 2008 Elsevier B.V. All rights reserved.

Cdc25B activity is regulated by 14-3-3

In the G2 phase cell cycle checkpoint arrest, the cdc25-dependent activation of cyclin B/cdc2, a critical step in regulating entry into mitosis, is blocked. Studies in yeast have demonstrated that the inhibition of cdc25 function involves 14-3-3 binding to cdc25, In humans, two cdc25 isoforms have roles in G2/M progression, cdc25B and cdc25C, both bind 14-3-3, Abrogating 14-3-3 binding to cdc25C attenuates the G2 checkpoint arrest, but the contribution of 14-3-3 binding to the regulation of cdc25B function is unknown. Here we demonstrate that high level over-expression of cdc25B in G2 checkpoint arrested cells can activate cyclin B/cdc2 and overcome the checkpoint arrest. Mutation of the major 14-3-3 binding site, S323, or removal of the N-terminal regulatory domain are strong activating mutations, increasing the efficiency with which the mutant forms of cdc25B not only overcome the arrest, but also initiate aberrant mitosis, We also demonstrate that 14-3-3 binding to the S323 site on cdc25B blocks access of the substrate cyclin/cdks to the catalytic site of the enzyme, thereby directly inhibiting the activity of cdc25B, This provides direct mechanistic evidence that 14-3-3 binding to cdc25B can regulate its activity, thereby controlling progression into mitosis.

Cdc25-dependent activation of cyclin A/cdk2 is blocked in G2 phase arrested cells independently of ATM/ATR

Cyclin A/cdk2 is active during S and G2 phases of the cell cycle, but its regulation and function during G2 phase is poorly understood. In this study we have examined the regulation of cyclin A/cdk2 activity during normal G2 phase progression and in genotoxin-induced G2 arrest. We show that cyclin A/cdk2 is activated in early G2 phase by a cdc25 activity. In the G2 phase checkpoint arrest initiated in response to various forms of DNA damage, the cdc25-dependent activation of both cyclin A/cdk2 and cyclin B1/cdc2 is blocked. Ectopic expression of cdc25B, but not cdc25C, in G2 phase arrested cells efficiently activated both cyclin A/cdk2 and cyclin B1/cdc2. Finally, we demonstrate that the block in cyclin A/cdk2 activation in the G2 checkpoint arrest is independent of ATM/ATR. We speculate that the ATM/ ATR-independent block in G2 phase cyclin A/cdk2 activation may act as a further layer of checkpoint control, and that blocking G2 phase cyclin A/cdk2 activation contributes to the G2 phase checkpoint arrest.

Up-regulation of p21(WAF1)/(CIP1) by histone deacetylase inhibitors reduces their cytotoxicity

Histone deacetylase inhibitors show promise as chemotherapeutic agents and have been demonstrated to block proliferation in a wide range of tumor cell lines. Much of this antiproliferative effect has been ascribed to the up-regulated expression of the cyclin-dependent kinase inhibitor p21(WAF1/CIP1). In this article, we report that p21 expression was up-regulated by relatively low doses of the histone deacetylase inhibitor azelaic bishydroxamic acid (ABHA) and correlated with a proliferative arrest. Higher doses of ABHA were cytotoxic. Cells that did not up-regulate p21 expression were hypersensitive to killing by ABHA and died via apoptosis, whereas up-regulation of p21 correlated with reduced sensitivity and a block in the apoptotic mechanism, and these cells seemed to die by necrosis. Using isogenic p21(+/+) and p21(-/-) cell lines and direct inhibition of caspase activity, we demonstrate that the reduced sensitivity to killing by ABHA is a consequence of inhibition of apoptosis by up-regulated p21 expression. These data indicate the enormous potential of therapeutic strategies that bypass the cytoprotective effect of p21 and act on the same molecular targets as the histone deacetylase inhibitors.

Class I histone deacetylases sequentially interact with MyoD and pRb during skeletal myogenesis

We describe a functional and biochemical link between the myogenic activator MyoD, the deacetylase HDAC1, and the tumor suppressor pRb. Interaction of MyoD with HDAC1 in undifferentiated myoblasts mediates repression of muscle-specific gene expression. Prodifferentiation cues, mimicked by serum removal, induce both downregulation of HDAC1 protein and pRb hypophosphorylation. Dephosphorylation of pRb promotes the formation of pRb-HDAC1 complex in differentiated myotubes. pRb-HDAC1 association coincides with disassembling of MyoD-HDAC1 complex, transcriptional activation of muscle-restricted genes, and cellular differentiation of skeletal myoblasts. A single point mutation introduced in the HDAC1 binding domain of pRb compromises its ability to disrupt MyoD-HDAC1 interaction and to promote muscle gene expression. These results suggest that reduced expression of HDAC1 accompanied by its redistribution in alternative nuclear protein complexes is critical for terminal differentiation of skeletal muscle cells.