Functional compartmentation of DNA precursors in human leukaemoblastoid cell lines

Summary . Human leukaemoblastoid cell lines were incubated with [³H]t hymidine and used to study the utilization for DNA synthesis and degradation of thymine nucleotides labelled via the salvage pathway. Three types of experiments were performed. (1) Cells were continuously labelled with exogenous [3H]thymidine at 3 7°C to compare the incorporation of label into DNA with the specific radioactivities of thymine nucleotides separated by chromatography on polyethyleneimine-cellulose. These studies demonstrated whether one or more functional pool of thymine nucleotides was present. (2) Intracellular thymine nucleotide pools were labelled with [³H]thymidine at 13°C, and the cells were subsequently incubated in unlabelled medium at 37°C in order to quantify the percentage of thymine nucleotides incorporated into DNA. The results showed that 18%, 75%, 75% and 91% of intracellular thymine nucleotides were incorporated into DNA during the chase, in Raji (B lymphoid), Nalm-6 (pre-B cell), HL60 (myeloid) and KM3 (c-ALL) cells respectively, whereas Molt4 (Thy-ALL) cells incorporated 100%. (3) In order to quantify the activity of the degradative pathway for thymine nucleotides in these cell lines, cells were labelled as described in (2) in the presence of cytosine arabinoside (an inhibitor of DNA synthesis). 100%, 90%, 65%, 38% and 20% of labelled thymine nucleotides were degraded in Raji, HL60, Nalm-6, KM3 and Molt-4 respectively. These results confirm our previous conclusion (Taheri et al, 1981a, b) that thymine nucleotides are functionally compartmentalized in human cells. If these results with cell lines can be extrapolated to apply to de novo leukaemia cases, they suggest that the degree of compartmentation differs widely between different leukaemia cell types. Thy-ALL cells utilized all their labelled thymine nucleotides for DNA synthesis, whereas B-ALL, cells utilized only 18% of their labelled thymine nucleotide nucleotides. Thy-ALL cells have the smallest degradative thymine pool and degradative capacity whereas B-ALL cells possess the largest degradative pool and capacity. AML, pre-B-ALL, c-ALL cell lines show intermediate results. If these results reflect those of the normal bone marrow cells from which each of the leukaemias arise, they suggest that with progressive B cell development in the bone marrow, degradative ability for DNA precursors increases and the efficiency of utilization of DNA precursors for DNA synthesis decreases.     

Expression analysis of mTOR-associated lncRNAs in multiple sclerosis

Metabolic Brain Disease - mTOR has been shown to be involved in the regulation of immune responses and differentiation of immune cells. This protein is a candidate molecule for unraveling the...     

Cardiovascular and hemodynamic effect of polyethylene glycol in Rats

BACKGROUND: Polyethylene Glycol (PEG) is a solvent and used in a wide range of biomedical applications. Many fatty-acid-based molecules cannot be administered without a solvent in vivo. PEG can be used to dissolve compounds to make them water soluble. However, the effect of PEG on the cardiovascular system has not been studied. In this study, we evaluated the effect of PEG on the cardiovascular system in rat models. METHODS: Twenty male Sprague-Dawley rats weighing 250-300 g were used in this study. The control group (10 rats) were injected intraperitoneally with 0.5 ml of 5% D/W in normal saline and the second group (10 rats) with PEG 400, 2 ml/kg ip, twice a day for 1 week. After 4 weeks, the rats underwent general anesthesia and a 1.4 French ultra miniature pressure volume catheter (Millar catheter) was placed in the left ventricle via the right carotid artery to measure comprehensive hemodynamic data. The data were analyzed with PVAN pressure-volume analysis software. RESULTS: All the systolic and diastolic parameters were similar in both groups except for the effective arterial elastance (Ea), which was decreased in the PEG group. There were no significant differences in maximum (dp/dt(max)) and minimum (dp/dt(min)) development of pressure stroke work, cardiac output, ejection fraction, end systolic volume (Ves), and end diastolic volume. CONCLUSIONS: We have demonstrated that PEG, as a solvent, decreases Ea in rats in comparison to a placebo. Therefore, PEG as a solvent should be used cautiously in the cardiovascular research.     

The effects of aquatic exercise on body composition and nonspecific low back pain in elderly males

[Purpose] The purpose of this study was to investigate the effect of aquatic exercises on nonspecific low back pain (LBP) in elderly males. [Subjects and Methods] Thirty-two elderly men aged 65 or older were recruited and randomly allocated to two groups: aquatic training (3 d/wk for 12 wk) or a control group. Body mass index (BMI), percentage of body fat (PBF), waist-hip ratio (WHR), and trunk muscle mass were measured before and after training. [Results] The results suggested that all obesity variables including BMI, WHR, and PBF of the aquatic training group were decreased significantly, while the trunk muscle mass of the aquatic training group was increased significantly. Furthermore, low back pain was decreased in the subjects after the intervention. [Conclusion] The water-based program improved LBP and body composition in the elderly men.Key words: Elderly, Low back pain, Body composition     

Enquête sur les pratiques françaises d’analgésie en chirurgie thoracique (réalisée avec le concours de l’ARCOTHOVA)

Objective

To assess the current practice of analgesia after thoracotomy and thoracoscopy in France.

Study design

Cross-sectional practice survey.

Material

Anaesthetist physicians, each referent for one of the French centres practicing thoracic surgery, during year 2012.

Methods

Electronic questionnaire about the activity of the centre in thoracic surgery, and modalities and estimated frequencies of different analgesic techniques. Primary assessment was the estimated percentage of acts, after imputation from original data.

Results

Eighty-four centres out of 103 (82 %) answered the questionnaire. Coupling locoregional to general anaesthesia involved 74 % of thoracotomies and 35 % of thoracoscopies. A practice (i.e. for more than 5 % of patients) of epidural analgesia was declared by 68 centres (81 %), and by 27 centres (32 %) for paravertebral block. The most current practices for epidural analgesia were: thoracic puncture, intraoperative initiation, ropivacaïne 0.2 % plus sufentanil, patient-controlled administration with infusion plus bolus, application more than 48 hrs post surgery. The practice rates for technique of paravertebral block were: Eason & Wyatt 34 %, ultrasound-guided 24 %, internal 42 %. The most frequent systemic analgesia was patient-controlled intravenous morphine. Ketamine was used in 60 % of the cases.

Conclusions

French practice of analgesia after thoracic surgery improved quality during the last decade, but more than one patient on four (compared to 8 % in UK) may have neither epidural nor paravertebral block, while such techniques are nowadays considered as standard.     

The clinical significance of small subarachnoid hemorrhages

With advancing technology, the sensitivity of computed tomography (CT) for the detection of traumatic subarachnoid hemorrhage (tSAH) continues to improve. Increased resolution has allowed for the detection of hemorrhage that is limited to one or two images of the CT exam. At our institution, all patients with a SAH require intensive care unit (ICU) admission, regardless of size. It was our hypothesis that patients with small subarachnoid hemorrhage experience favorable outcomes, and may not require the intensive monitoring offered in the ICU. This retrospective study evaluated 62 patients between 2011 and 2014 who presented to our Level I trauma center emergency room for acute traumatic injuries, and found to have subarachnoid hemorrhages on CT examination. The grade of subarachnoid hemorrhage was determined using previously utilized scoring systems, such as the Fisher, Modified Fisher, and Claassen grading systems. Electronic medical records were used to evaluate for medical decline, neurological decline, neurosurgical intervention, and overall hospital course. Admitting co-morbidities were noted, as were the presence of patient intoxication and use of anticoagulants. Patient outcomes were based on discharge summaries upon which the neurological status of the patient was assessed. Each patient was given a score based on the Glasgow outcome scale. The clinical and imaging profile of 62 patients with traumatic SAH were studied. Of the 62 patients, 0 % underwent neurosurgical intervention, 6.5 % had calvarial fractures, 25.8 % had additional intracranial hemorrhages, 27.4 % of the patients had significant co-morbidities, and 1.6 % of the patients expired. Patients with low-grade tSAH spent less time in the ICU, demonstrated neurological and medical stability during hospitalization. None of the patients with low-grade SAH experienced seizure during their admission. In our study, patients with low-grade tSAH demonstrated favorable clinical outcomes. This suggests that patients may not require as aggressive monitoring as is currently provided for those with tSAH.