Rational optimization of a transcription factor activation domain inhibitor.

Transcription factors are among the most attractive therapeutic targets but are considered largely 'undruggable' in part due to the intrinsically disordered nature of their activation domains. Here we show that the aromatic character of the activation domain of the androgen receptor, a therapeutic target for castration-resistant prostate cancer, is key for its activity as transcription factor, allowing it to translocate to the nucleus and partition into transcriptional condensates upon activation by androgens. On the basis of our understanding of the interactions stabilizing such condensates and of the structure that the domain adopts upon condensation, we optimized the structure of a small-molecule inhibitor previously identified by phenotypic screening. The optimized compounds had more affinity for their target, inhibited androgen-receptor-dependent transcriptional programs, and had an antitumorigenic effect in models of castration-resistant prostate cancer in cells and in vivo. These results suggest that it is possible to rationally optimize, and potentially even to design, small molecules that target the activation domains of oncogenic transcription factors.

Outcomes of severe sepsis and septic shock patients after stratification by initial lactate value / 世界急诊医学杂志（英文）

BACKGROUND: In the setting of severe sepsis and septic shock, mortality increases when lactate levels are ≥ 4 mmol/L. However, the consequences of lower lactate levels in this population are not wel understood. The study aimed to determine the in-hospital mortality associated with severe sepsis and septic shock when initial lactate levels are < 4 mmol/L. METHODS: This is a retrospective cohort study of septic patients admitted over a 40-month period. Totally 338 patients were divided into three groups based on initial lactate values. Group 1 had lactate levels < 2 mmol/L; group 2: 2–4 mmol/L; and group 3: ≥ 4 mmol/L. The primary outcome was in-hospital mortality. RESULTS: There were 111 patients in group 1, 96 patients in group 2, and 131 in group 3. The mortality rates were 21.6％, 35.4％, and 51.9％ respectively. Univariate analysis revealed the mortality differences to be statistically significant. Multivariate logistic regression demonstrated higher odds of death with higher lactate tier group, however the findings did not reach statistical significance. CONCLUSION: This study found that only assignment to group 3, initial lactic acid level of ≥ 4 mmol/L, was independently associated with increased mortality after correcting for underlying severity of illness and organ dysfunction. However, rising lactate levels in the other two groups were associated with increased severity of illness and were inversely proportional to prognosis.

Assessment of pollution of the Boca de Camichin Estuary in Nayarit (Mexico) and its influence on oxidative stress in Crassostrea corteziensis oysters.

Boca de Camichin Estuary is one of the main producers of Crassostrea corteziensis oysters in Mexico, but the presence of pollutants can affect oyster production. Molluscs produce reactive oxygen species (ROS) in response to changes in the environment and pollution. These ROS induce oxidative damage in biomolecules. The main objective of this study was to evaluate pollution in the estuary and the subsequent oxidative stress in C. corteziensis oysters during the 2010 production cycle. For this aim, we performed monthly samplings in the oyster farms from January to May. We took water samples to quantify polycyclic aromatic hydrocarbon (PAH) and metal content; also, we evaluated oxidative damage (lipoperoxidation, lipidic hydroperoxides, protein oxidation) and enzyme activity (CAT, SOD, GPx, GST and AChE) in oyster gills. The results show the presence of Cu, Fe, Mn, naphthalene, benz[a]anthracene, pyrene, benz[a]pyrene and benzo[k]fluoranthene. On the other hand, AChE activity was not inhibited, which suggests that organophosphorus pollutants or carbamates were absent. Regarding oxidative stress, oysters from the estuary had oxidative damage in lipids, not proteins, and altered antioxidant enzyme activity, when compared to control organisms. Interestingly, we did not observe any correlation between the pollutants and the oxidative stress parameters evaluated in this study. Thus, we cannot rule out that a synergistic effect between the environmental variables and the pollutants is causing the oxidative stress in these oysters.

Neumoencéfalo: una inusual complicación de la artrodesis lumbar. Caso clínico y revision de la literatura / Pneumocephalus: an unusual complication of lumbar arthrodesis. A clinical case and literature review

El neumoencéfalo es una complicación poco frecuente pero grave de la cirugía de la columna vertebral, su manejo y fisiopatología no es ampliamente conocida. La incidencia de neumoencéfalo sintomático a tensión, secundario a una artrodesis vertebral posterior es desconocida. Caso clínico. Presentamos el caso de una paciente mujer de 41 años de edad, con diagnóstico de discopatía L3-L4, L4-L5 y hernia discal izquierda L4-L5. Se realizó una artrodesis vertebral posterior L3-L5, discectomías L3-L4 y L4-L5 y liberación de la raíz L5 izquierda, sin complicaciones aparentes. Transcurridas 24 h después de la cirugía, la paciente inicia cuadro de cefalea generalizada de fuerte intensidad, rigidez de nuca y disartria. Se realizan TAC y RMN que muestran un enorme neumoencéfalo en el espacio subaracnoideo, a predominio del lóbulo frontal izquierdo, sin desplazamiento de la línea media, con origen en el conducto raquídeo lumbar. La paciente fue tratada de forma conservadora, presentando a partir de las 72 h mejoría neurológica progresiva, hasta la normalización clínica y radiológica después de 7 días. Discusión. El neumoencéfalo es una complicación rara pero potencialmente grave de la cirugía de columna, relacionada en la mayoría de los casos con desgarro dural accidental durante la cirugía. La mayoría de las colecciones son pequeñas, se comportan de forma benigna, y responden al tratamiento conservador. En un gran número de pacientes, puede comportarse como cualquier lesión ocupante de espacio, por lo que se necesita un alto grado de sospecha clínica para hacer el diagnóstico y tratamiento oportuno, y prevenir la morbimortalidad no deseadas (AU)

Pneumocephalus is an uncommon but serious complication of spinal surgery and its management and pathophysiology is not widely recognized. The incidence of symptomatic tension pneumocephalus secondary to posterior spinal arthrodesis is unknown. Case report. The case is reported of a rare case of a 41 year old woman with diagnosis of L3-L4, L4-L5 disc disease and left disc herniation L4-L5. A posterior spinal arthrodesis L3-L5, L3-L4 and L4-L5 discectomies and release of the left L5 root, was performed without apparent complications. Twenty-four hours after surgery the patient developed generalized headache, neck stiffness, and dysarthria. MRI and CT scans revealed a huge pneumocephalus in the subarachnoid space, predominantly in the left frontal lobe without midline shift, which originated in the lumbar spinal canal. The patient was treated conservatively, with progressive neurological improvement after 72 hours, and clinical and radiological normalization after 7 days. Discussion. Pneumocephalus is a rare but potentially serious complication of spine surgery related in most cases with inadvertent dural tear during the operation. Most collections are small, behave benign, and respond to conservative therapy. In the present case, an inadvertent dural tear, produced a pneumocephalus. A high degree of suspicion is needed to make the diagnosis, prompt treatment, as well as remedying the source of air to prevent unwanted morbidity and mortality (AU)

Pneumocephalus: An unusual complication of lumbar arthrodesis. A clinical case and literature review.

UNLABELLED: Pneumocephalus is an uncommon but serious complication of spinal surgery and its management and pathophysiology is not widely recognized. The incidence of symptomatic tension pneumocephalus secondary to posterior spinal arthrodesis is unknown. CASE REPORT: The case is reported of a rare case of a 41 year old woman with diagnosis of L3-L4, L4-L5 disc disease and left disc herniation L4-L5. A posterior spinal arthrodesis L3-L5, L3-L4 and L4-L5 discectomies and release of the left L5 root, was performed without apparent complications. Twenty-four hours after surgery the patient developed generalized headache, neck stiffness, and dysarthria. MRI and CT scans revealed a huge pneumocephalus in the subarachnoid space, predominantly in the left frontal lobe without midline shift, which originated in the lumbar spinal canal. The patient was treated conservatively, with progressive neurological improvement after 72 hours, and clinical and radiological normalization after 7 days. DISCUSSION: Pneumocephalus is a rare but potentially serious complication of spine surgery related in most cases with inadvertent dural tear during the operation. Most collections are small, behave benign, and respond to conservative therapy. In the present case, an inadvertent dural tear, produced a pneumocephalus. A high degree of suspicion is needed to make the diagnosis, prompt treatment, as well as remedying the source of air to prevent unwanted morbidity and mortality.

Propuesta de algoritmo global de tratamiento del hallux rigidus según la medicina basada en la evidencia / Proposed global treatment algorithm for hallux rigidus according to evidence-based medicine

Introducción. El hallux rigidus es la artrosis más frecuente en el pie y tobillo. Existen numerosas revisiones respecto al tratamiento quirúrgico, pero escasas publicaciones que aborden la eficacia del tratamiento conservador. Objetivo. Presentar un algoritmo global de tratamiento completo para todos los grados de esta enfermedad. Métodos. Revisión sistemática de la evidencia disponible hasta octubre de 2013 utilizando las siguientes fuentes: Pubmed y PEDro database (physiotherapy evidence database) de artículos sobre tratamiento de hallux rigidus que comuniquen sus resultados y de los que pudieran obtenerse grados de recomendación. Resultados. Obtuvimos 112 artículos sobre tratamiento conservador y 609 sobre tratamiento quirúrgico. Finalmente solo 4 cumplían los criterios de inclusión. Conclusiones. El uso de ortesis a medida o modificaciones del calzado, la infiltración con hialuronato, la queilectomía en grados moderados y la artrodesis metatarsofalángica en grados avanzados, son los únicos procedimientos contrastados con grado de evidencia B o moderada en el tratamiento del hallux rigidus (AU)

Introduction. Hallux rigidus is the most common arthritis of the foot and ankle. There are numerous reviews on the surgical treatment, but few publications that address the effectiveness of conservative treatment. Objective. To present a comprehensive algorithm for treatment of all grades of this disease. Methods. Literature search in the following sources: Pubmed and PEDro database (physiotherapy evidence database) until October 2013 for articles on treatment hallux rigidus to record levels of evidence. Results. A total of 112 articles were obtained on conservative treatment and 609 on surgical treatment. Finally, only 4 met the inclusion criteria. Conclusions. The use of orthoses or footwear modifications, infiltration with hyaluronate, cheilectomy in moderate degrees and the metatarsophalangeal arthrodesis for advanced degrees, are the only procedures contrasted with grade B or moderate evidence in the treatment of hallux rigidus (AU)

[Proposed global treatment algorithm for hallux rigidus according to evidence-based medicine]. / Propuesta de algoritmo global de tratamiento del hallux rigidus según la medicina basada en la evidencia.

INTRODUCTION: Hallux rigidus is the most common arthritis of the foot and ankle. There are numerous reviews on the surgical treatment, but few publications that address the effectiveness of conservative treatment. OBJECTIVE: To present a comprehensive algorithm for treatment of all grades of this disease. METHODS: Literature search in the following sources: Pubmed and PEDro database (physiotherapy evidence database) until October 2013 for articles on treatment hallux rigidus to record levels of evidence. RESULTS: A total of 112 articles were obtained on conservative treatment and 609 on surgical treatment. Finally, only 4 met the inclusion criteria. CONCLUSIONS: The use of orthoses or footwear modifications, infiltration with hyaluronate, cheilectomy in moderate degrees and the metatarsophalangeal arthrodesis for advanced degrees, are the only procedures contrasted with grade B or moderate evidence in the treatment of hallux rigidus.

Evaluation of pollution in Camichin estuary (Mexico): pro-oxidant and antioxidant response in oyster (Crassostrea corteziensis).

The physiological system of molluscs, particularly pro-oxidant and antioxidant mechanisms, could be altered by pollutants and induce disturbance on health status and productive parameters of aquatic organisms, such as oyster. Therefore, the aim of this study was to evaluate the chemical contamination in water (total metals and polycyclic aromatic hydrocarbons) and oxidative stress parameters in oysters (Crassostrea corteziensis) in Camichin estuary, located in Mexican Tropical Pacific. The results obtained showed the presence of arsenic, lead and zinc, as well as naphthalene, pyrene and benzo[a]pyrene in concentrations relatively higher than criteria established by local and international guidelines. Regarding the biomarkers of oxidative stress response (H2O2 and O2 concentration, catalase activity, lipid peroxidation, and hydroperoxide concentration), differences between oyster from estuary and control group were significant. These results indicate that these pollutants could be related with oxidative stress detected in oyster.

[Our experience with orthopedic damage control in high-energy tibial pylon fractures]. / Nuestra experiencia en la aplicación del control de daños ortopédico en fracturas de pilón tibial por alta energía.

High-energy tibial pylon fractures represent some of the most severe injuries of the ankle joint and currently represent a challenge for the orthopedic surgeon. These are usually polytraumatized patients and before admitting them into the traumatology unit, spinal cord, pelvic or thoracoabdominal injuries should be ruled out. Due to the special anatomy of the area, its thin skin cover and subcutaneous location, soft tissues are usually severely affected and this is key when choosing the time for a surgical intervention. Although the definitive treatment of these injuries is controversial, the so called two-stage treatment seems to predominate in order to minimize soft tissue iatrogenic injuries applying the concept of orthopedic damage control of the limb. We present the preliminary results of 10 patients operated with this method at our center.

Escleroterapia con bleomicina en malformaciones vasculares de bajo flujo. Experiencia y revisión del tema / Bleomycin sclerotherapy for low-flow vascular malformations, our experience and literature review

Las anomalías vasculares son lesiones típicas de los pacientes pediátricos y se dividen en dos categorías: tumores vasculares y malformaciones vasculares de alto y bajo flujo. Estas últimas pueden tratarse de diversos modos: laserterapia, drenaje, aspiración, cirugía o escleroterapia, dependiendo del tipo de lesión y de su localización. Entre los agentes esclerosantes utilizados, la bleomicina ha demostrado tener buenos resultados en el tratamiento de estas lesiones. En este artículo presentamos nuestra experiencia en el tratamiento de las malformaciones vasculares de bajo flujo mediante escleroterapia con bleomicina intralesional. Desarrollamos un estudio descriptivo retrospectivo sobre 30 pacientes que presentaban malformación vascular de bajo flujo y fueron tratados con bleomicina intralesional. Los resultados fueron buenos o excelentes en 22 pacientes y regulares o malos en los 8 restantes. De acuerdo a nuestra casuística y a la literatura revisada, la escleroterapia con bleomicina es una alternativa terapéutica eficaz y segura en el tratamiento de las malformaciones vasculares de bajo flujo (AU)

Vascular anomalies are common in children and can be divided into two categories, vascular tumours and vascular malformations: high-flow or low-flow. The latter can be treated in different ways such as lasertherapy, drainage, aspiration, surgery or sclerotherapy depending on the type and location of the lesion. Among the accepted sclerosing agents, bleomycin has proven good results in the treatment of this condition. Herein we present our experience in the treatment of low-flow vascular malformations with intralesional bleomycin injection. This is a retrospective, descriptive study with 30 patients presenting a low-flow vascular malformation treated with intralesional bleomycin injection. Our results are good or excellent in 22 patients and poor in the other 8. According to our case series and the consulted literature, sclerotherapy with intralesional bleomycin injection is an effective and safe treatment for low-flow vascular malformation (AU)

Increased interactions between PKA and NF-κB signaling in the hippocampus following loss of cholinergic input.

Neuropsychiatric disorders such as depression are frequently associated with Alzheimer's disease (AD) and the degeneration of cholinergic basal forebrain neurons and reductions in acetylcholine that occur in AD have been identified as potential mediators of these secondary neuropsychiatric symptomologies. Indeed, removal of cholinergic innervation to the hippocampus via selective immunolesions of septohippocampal cholinergic neurons induces dysfunction of the hypothalamic-pituitary-adrenocortical (HPA) axis and decreases glucocorticoid receptor expression (GR). A subsequent study showed that loss of cholinergic input decreases the activity of the catalytic subunit of protein kinase A (PKAc) and lessens the interaction of protein kinase A (PKA) with GR. Because cross-coupling between nuclear factor-κB (NF-κB) p65 and GR depends on PKA signaling, the present study was conducted to evaluate the status of NF-κB as well as interactions of PKA with NF-κB in the hippocampus following cholinergic denervation. Expression of cytosolic NF-κB p65 was diminished and IκB was degraded in the hippocampus of cholinergic immunolesioned rats compared to the controls. Immunolesions also increased NF-κB p65 Ser276 phosphorylation, as well as interactions between PKAc and NF-κB p65. These results indicate that loss of cholinergic input to the hippocampus results in decreased PKA activity and increased NF-κB activity. Such altered signaling may contribute to psychiatric symptoms, including depression, in patients with AD.

Residual gammaH2AX foci as an indication of lethal DNA lesions.

BACKGROUND: Evidence suggests that tumor cells exposed to some DNA damaging agents are more likely to die if they retain microscopically visible gammaH2AX foci that are known to mark sites of double-strand breaks. This appears to be true even after exposure to the alkylating agent MNNG that does not cause direct double-strand breaks but does produce gammaH2AX foci when damaged DNA undergoes replication. METHODS: To examine this predictive ability further, SiHa human cervical carcinoma cells were exposed to 8 DNA damaging drugs (camptothecin, cisplatin, doxorubicin, etoposide, hydrogen peroxide, MNNG, temozolomide, and tirapazamine) and the fraction of cells that retained gammaH2AX foci 24 hours after a 30 or 60 min treatment was compared with the fraction of cells that lost clonogenicity. To determine if cells with residual repair foci are the cells that die, SiHa cervical cancer cells were stably transfected with a RAD51-GFP construct and live cell analysis was used to follow the fate of irradiated cells with RAD51-GFP foci. RESULTS: For all drugs regardless of their mechanism of interaction with DNA, close to a 1:1 correlation was observed between clonogenic surviving fraction and the fraction of cells that retained gammaH2AX foci 24 hours after treatment. Initial studies established that the fraction of cells that retained RAD51 foci after irradiation was similar to the fraction of cells that retained gammaH2AX foci and subsequently lost clonogenicity. Tracking individual irradiated live cells confirmed that SiHa cells with RAD51-GFP foci 24 hours after irradiation were more likely to die. CONCLUSION: Retention of DNA damage-induced gammaH2AX foci appears to be indicative of lethal DNA damage so that it may be possible to predict tumor cell killing by a wide variety of DNA damaging agents simply by scoring the fraction of cells that retain gammaH2AX foci.

Endogenous and radiation-induced expression of gammaH2AX in biopsies from patients treated for carcinoma of the uterine cervix.

BACKGROUND AND PURPOSE: The possibility of using gammaH2AX foci as a marker of DNA damage and as a potential predictor of tumour response to treatment was examined using biopsies from 3 sets of patients with advanced carcinoma of the cervix. The relation between endogenous gammaH2AX expression and hypoxia was also examined. MATERIALS AND METHODS: Set 1 consisted of 26 biopsies that included pre-treatment and 24h post-radiation treatment samples. Pre-treatment biopsies from 12 patients in Set 2 were used to develop image analysis software while pre-treatment biopsies from 33 patients in Set 3 were examined for the relation between staining for the hypoxia marker pimonidazole and endogenous gammaH2AX expression. Formalin-fixed paraffin-embedded sections were analyzed after antigen retrieval and fluorescence antibody labeling for the hypoxia markers CAIX or pimonidazole in combination with gammaH2AX staining. RESULTS: Before treatment, 24+/-19% of cells contained gammaH2AX foci, with most positive cells containing fewer than 5 foci per nucleus. Twenty-four hours after exposure to the first fraction of 1.8-2.5Gy, 38+/-19% contained foci. CAIX positive cells were 1.4 times more likely to exhibit endogenous gammaH2AX foci, and pimonidazole-positive cells were 2.8 times more likely to contain gammaH2AX foci. For 18 patients for whom both pre-treatment and 24h post-irradiation biopsies were available, local control was unrelated to the fraction of cells that retained gammaH2AX foci. However, 24h after irradiation, tumours that had received 2.5Gy showed a significantly higher fraction of cells with residual gammaH2AX foci than tumours given 1.8Gy. CONCLUSIONS: Endogenous gammaH2AX foci are enriched in hypoxic tumour regions. Small differences in delivered dose can produce quantifiable differences in residual DNA damage that can overshadow inter-tumour differences in response.

Blockade of GABA(B) receptors completely reverses age-related learning impairment.

Impaired cognitive functions are well-described in the aging process. GABA(B) antagonists can facilitate learning and memory in young subjects, but these agents have not been well-characterized in aging. Here we show a complete reversal of olfactory discrimination learning deficits in cognitively-impaired aged Fischer 344 rats using the GABA(B) antagonist CGP55845, such that drug treatment restored performance to that on par with young and cognitively-unimpaired aged subjects. There was no evidence that this improved learning was due to enhanced olfactory detection abilities produced by the drug. These results highlight the potential of targeting GABA(B) receptors to ameliorate age-related cognitive deficits and demonstrate the utility of olfactory discrimination learning as a preclinical model for testing novel therapies to improve cognitive functions in aging.

gammaH2AX expression in tumors exposed to cisplatin and fractionated irradiation.

PURPOSE: Is retention of gammaH2AX foci useful as a biomarker for predicting the response of xenograft tumors to cisplatin with X-ray? Is a similar approach feasible using biopsies from patients with cervical cancer? EXPERIMENTAL DESIGN: Mice bearing SiHa, WiDr, or HCT116 xenograft tumors were exposed to cisplatin and/or three daily doses of 2 Gy. Tumors were excised 24 h after treatment and single cells were analyzed for clonogenic fraction and retention of gammaH2AX foci. Tumor biopsies were examined using 47 paraffin-embedded sections from untreated tumors and 24 sections from 8 patients undergoing radiochemotherapy for advanced cancer of the cervix. RESULTS: Residual gammaH2AX measured 24 h after cisplatin injection accurately predicted surviving fraction in SiHa and WiDr xenografts. When a clinically equivalent protocol using cisplatin and fractionated irradiation was employed, the fraction of xenograft cells lacking gammaH2AX ranked survival accurately but underestimated tumor cell kill. Residual gammaH2AX foci were detected in clinical samples; on average, only 25% of tumor nuclei exhibited one or more gammaH2AX foci before treatment and 74% after the start of treatment. CONCLUSION: gammaH2AX can provide useful information on the response of human tumors to the combination of cisplatin and radiation, but prediction becomes less accurate as more time elapses between treatment and tumor biopsy. Use of residual gammaH2AX as a biomarker for response is feasible when cell survival exceeds approximately 20%, but heterogeneity in endogenous and treatment-induced gammaH2AX must be considered.

Explanation for excessive DNA single-strand breaks and endogenous repair foci in pluripotent mouse embryonic stem cells.

Pluripotent mouse embryonic stem cells (mES cells) exhibit approximately 100 large gammaH2AX repair foci in the absence of measurable numbers of DNA double-strand breaks. Many of these cells also show excessive numbers of DNA single-strand breaks (>10,000 per cell) when analyzed using the alkaline comet assay. To understand the reasons for these unexpected observations, various methods for detecting DNA strand breaks were applied to wild-type mES cells and to mES cells lacking H2AX, ATM, or DNA-PKcs. H2AX phosphorylation and expression of other repair complexes were measured using flow and image analysis of antibody-stained cells. Results indicate that high numbers of endogenous gammaH2AX foci and single-strand breaks in pluripotent mES cells do not require ATM or DNA-PK kinase activity and appear to be associated with global chromatin decondensation rather than pre-existing DNA damage. This will limit applications of gammaH2AX foci analysis in mES cells to relatively high levels of initial or residual DNA damage. Excessive numbers of single-strand breaks in the alkaline comet assay can be explained by the vulnerability of replicating chromatin in mES cells to osmotic shock. This suggests that caution is needed in interpreting results with the alkaline comet assay when applied to certain cell types or after treatment with agents that make chromatin vulnerable to osmotic changes. Differentiation of mES cells caused a reduction in histone acetylation, gammaH2AX foci intensity, and DNA single-strand breakage, providing a link between chromatin structural organization, excessive gammaH2AX foci, and sensitivity of replicating mES cell chromatin to osmotic shock.

Mouse but not human embryonic stem cells are deficient in rejoining of ionizing radiation-induced DNA double-strand breaks.

Mouse embryonic stem (mES) cells will give rise to all of the cells of the adult mouse, but they failed to rejoin half of the DNA double-strand breaks (dsb) produced by high doses of ionizing radiation. A deficiency in DNA-PK(cs) appears to be responsible since mES cells expressed <10% of the level of mouse embryo fibroblasts (MEFs) although Ku70/80 protein levels were higher than MEFs. However, the low level of DNA-PK(cs) found in wild-type cells appeared sufficient to allow rejoining of dsb after doses <20Gy even in G1 phase cells. Inhibition of DNA-PK(cs) with wortmannin and NU7026 still sensitized mES cells to radiation confirming the importance of the residual DNA-PK(cs) at low doses. In contrast to wild-type cells, mES cells lacking H2AX, a histone protein involved in the DNA damage response, were radiosensitive but they rejoined double-strand breaks more rapidly. Consistent with more rapid dsb rejoining, H2AX(-/-) mES cells also expressed 6 times more DNA-PK(cs) than wild-type mES cells. Similar results were obtained for ATM(-/-) mES cells. Differentiation of mES cells led to an increase in DNA-PK(cs), an increase in dsb rejoining rate, and a decrease in Ku70/80. Unlike mouse ES, human ES cells were proficient in rejoining of dsb and expressed high levels of DNA-PK(cs). These results confirm the importance of homologous recombination in the accurate repair of double-strand breaks in mES cells, they help explain the chromosome abnormalities associated with deficiencies in H2AX and ATM, and they add to the growing list of differences in the way rodent and human cells deal with DNA damage.

Effect of sub-lethal concentrations of endosulfan on phagocytic and hematological parameters in Nile tilapia (Oreochromis niloticus).

The effect of endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide), an organochlorine pesticide, was evaluated on phagocytic (phagocytic index and percentage of active cells) and hematological parameters in Nile tilapia. Experimental data showed that an acute exposure to endosulfan (4.0 and 7.0 microg/L) induces a significant decrease in the phagocytic index and the percentage of active cells in peripherical blood of Nile tilapia. However, hemoglobin concentration (Hb), hematocrit (Hto), red blood cell count (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were not significantly altered in fish exposed to endosulfan compared with control group.

Electrophysiological and morphological heterogeneity of slow firing neurons in medial septal/diagonal band complex as revealed by cluster analysis.

Slow firing septal neurons modulate hippocampal and neocortical functions. Electrophysiologically, it is unclear whether slow firing neurons belong to a homogeneous neuronal population. To address this issue, whole-cell patch recordings and neuronal reconstructions were performed on rat brain slices containing the medial septum/diagonal band complex (MS/DB). Slow firing neurons were identified by their low firing rate at threshold (<5 Hz) and lack of time-dependent inward rectification (Ih). Unsupervised cluster analysis was used to investigate whether slow firing neurons could be further classified into different subtypes. The parameters used for the cluster analysis included latency for first spike, slow after-hyperpolarizing potential, maximal frequency and action potential (AP) decay slope. Neurons were grouped into three major subtypes. The majority of neurons (55%) were grouped as cluster I. Cluster II (17% of neurons) exhibited longer latency for generation of the first action potential (246.5+/-20.1 ms). Cluster III (28% of neurons) exhibited higher maximal firing frequency (25.3+/-1.7 Hz) when compared with cluster I (12.3+/-0.9 Hz) and cluster II (11.8+/-1.1 Hz) neurons. Additionally, cluster III neurons exhibited faster action potentials at suprathreshold. Interestingly, cluster II neurons were frequently located in the medial septum whereas neurons in cluster I and III appeared scattered throughout all MS/DB regions. Sholl's analysis revealed a more complex dendritic arborization in cluster III neurons. Cluster I and II neurons exhibited characteristics of "true" slow firing neurons whereas cluster III neurons exhibited higher frequency firing patterns. Several neurons were labeled with a cholinergic marker, Cy3-conjugated 192 IgG (p75NTR), and cholinergic neurons were found to be distributed among the three clusters. Our findings indicate that slow firing medial septal neurons are heterogeneous and that soma location is an important determinant of their electrophysiological properties. Thus, slow firing neurons from different septal regions have distinct functional properties, most likely related to their diverse connectivity.

Clinical variables related with in-stent restenosis late regression after bare metal coronary stenting

In-stent restenosis (ISR) has an incidence between 20% and 30% using bare metal stents. ISR late regression phenomenon (ISRLR) has been previously described, but clinical variables related with this phenomenon remain unclear. The aim of the study was to identify the variables related with ISRLR. METHODS: We identified from our data base 30 patients between November 1995 and September 2002 that fulfilled the following criteria: 1) Documented ISR at follow-up angiography (CA-1); 2) treated medically; and 3) Referred for a second follow-up angiography (CA-2). at least 3 months after CA-1. ISRLR was defined as a > 0.2 mm increase in MLD between CA-1 and CA-2, calculated as the 2-fold of our inter-observer variability. ISR late progression was defined as a > 0.2 mm decrease in minimum lumen diameter (MLD) between CA-1 and CA-2. RESULTS: At the time of CA-2 only 2 patients (6.7%) had symptoms related with the previously stented vessel. We found a mean MLD of 1.03+/-0.34 mm and 1.54+/-0.48 mm at CA-1 and CA-2 respectively (AMLD = 0.51 +/-0.34 mm; p < 0.001). Twenty four patients (80.0%) had ISRLR. Two variables were related to the presence or absence ISRLR: Current smoking at the time of coronary stenting (70.8% vs 20.0% respectively, p = 0.026) and acute coronary syndrome as clinical indication for coronary stenting (and 83.5% vs 40.0% respectively, p = 0.029). CONCLUSION: ISRLR is a frequent phenomenon in patients with ISR treated medically, probably contributing to the benign long-term clinical outcome that has been previously described in patients with asymptomatic or mildly symptomatic ISR. Current smoking at the time of coronary stenting and acute coronary syndrome as clinical indication for coronary stenting are associated with this phenomenon.