Growth requirements,growth factor responsiveness,and growth factor secretion of three human embryonal carcinoma cell lines

Summary The in vitro growth requirements of three human embryonal carcinoma cell lines (H 12.7, 2102 EP, 1428 A) were investigated. The basal medium DME/F12 supplemented with insulin, transferrin, and low-density and high-density lipoproteins was sufficient to support substantial multiplication of all three lines. The most efficient attachment factor was either fibronectin (for 2102 EP and 1428 A) or collagen type I (H 12.7). In a serum-free system the influence of epidermal growth factor (EGF), insulin-like growth factor I, multiplication stimulating activity (MSA), a platelet extract, and the glucocorticoids dexamethasone and hydrocortisone, as determined by the DNA synthesis rate of the cells, was generally minimal. However, the DNA synthesis rate of cell lines H 12.7 and 2102 EP was increased by MSA, and the line with the highest potential to differentiate (H 12.7) was stimulated by EGF. All three cell lines secreted growth factors in a heterologous stimulation assay. Insulin-like growth factors I and II were not part of the growth promoting activity. The inhibitory effect of a monoclonal anti-EGF antibody on the ³H-thymidine incorporation of cell line 2102 EP might indicate autocrine secretion of EGF or an EGF-like factor by this cell line.     

Recruitment of DNA methyltransferase I to DNA repair sites

In mammalian cells, the replication of genetic and epigenetic information is directly coupled; however, little is known about the maintenance of epigenetic information in DNA repair. Using a laser microirradiation system to introduce DNA lesions at defined subnuclear sites, we tested whether the major DNA methyltransferase (Dnmt1) or one of the two de novo methyltransferases (Dnmt3a, Dnmt3b) are recruited to sites of DNA repair in vivo. Time lapse microscopy of microirradiated mammalian cells expressing GFP-tagged Dnmt1, Dnmt3a, or Dnmt3b1 together with red fluorescent protein-tagged proliferating cell nuclear antigen (PCNA) revealed that Dnmt1 and PCNA accumulate at DNA damage sites as early as 1 min after irradiation in S and non-S phase cells, whereas recruitment of Dnmt3a and Dnmt3b was not observed. Deletion analysis showed that Dnmt1 recruitment was mediated by the PCNA-binding domain. These data point to a direct role of Dnmt1 in the restoration of epigenetic information during DNA repair.     

Early clinical symptoms and therapy of haemorrhages in old age (author's transl)]

There is hardly a bleeding, where the extrinsic-and/or the intrinsic-system of the coagulation does not take part in. Haemorrhages represent a symptom only, and it is always to clear, if they are come from a local process of illness or from a general tendency of haemorrhage. There is point to the clinical differences of great bleeding (coagulopathy) and bleedings like points (the causes lie in the thrombocytes or in a vascular damage). The early clinical symptoms and the therapy of haemorrhages by the old human without the primary disturbance of the coagulate-system are discussed.     

A hierarchic approach for experimental investigations into the pathogenesis of acute pancreatitis

The complexity of pathogenesis and clinical observations of acute pancreatitis demands a simultaneous experimental investigation at various structural and functional levels. The induction of acute pancreatitis by transformation of a pancreatic edema after short-term pancreatic ischemia was used for studies on the contribution of an alteration of energy metabolism to pathogenesis. The experiments demonstrate that in 70 percent of the rats the pancreatic edema was transformed into acute pancreatitis by 20 min ischemia. This was checked by morphological and enzymic means. For studying the influence of short-term ischemia in the cellular metabolism of acinar cells, pancreatic exocrine cells have been isolated from normal pancreas or that altered by ischemia. These cells were morphologically characterized and their capacity of energy metabolism was quantified.     

Insufficient tissue ablation by rotational atherectomy leads to worse long-term results in comparison with balloon angioplasty alone for the treatment of diffuse in-stent restenosis: insights from the intravascular ultrasound substudy of the ARTIST randomized multicenter trial.

The ARTIST trial demonstrated a worse outcome for patients with in-stent restenosis (ISR) treated with rotational atherectomy (RA) and adjunctive balloon angioplasty (PTCA) as compared to PTCA alone. This intravascular ultrasound (IVUS) substudy compares effects of lumen enlargement and examines reasons for failure of RA in this setting. IVUS (n = 56) was performed after each interventional step and at follow-up. Volumetric lumen gain measured 79 +/- 68 mm(3) after PTCA (13 +/- 4 atm) as compared to 44 +/- 26 mm(3) after RA and adjunctive PTCA (7 +/- 3 atm; P < 0.0001). RA itself enlarged lumen by only 19 +/- 17 mm(3) and stent volume was 47% smaller as compared to high-pressure PTCA. Low-pressure strategy after RA did not prevent tissue growth during follow-up (19 +/- 25 vs. 36 +/- 38 mm(3); RA vs. PTCA; P = 0.09). Consequently, net lumen gain after PTCA was 82% higher compared to RA (46 +/- 54 vs. 25 +/- 24 mm(3); P = 0.09). Further stent expansion is the key mechanism to achieve luminal gain by PTCA of ISR. Neointimal ablation by RA has only minor effects. Low-pressure PTCA does not prevent recurrent tissue growth and failed for treatment of ISR due to insufficient stent expansion.     

Alpha-receptor restriction of coronary blood flow during atrial fibrillation

The effects of atrial fibrillation (AF) on coronary circulation before and after alpha-receptor blockade were studied in 14 anesthetized, open-chest dogs. AF was induced by electrical stimulation of the left atrial appendage; identical rhythmic heart rates were adjusted by left atrial pacing. During atrial pacing, coronary vascular resistance (CVR) was 0.97 +/- 0.10 mm Hg X min X 100 g/ml (resistance units [RU]), coronary blood flow (CBF) 125 +/- 14 ml/min X 100 g, and oxygen saturation 30 +/- 2%; plasma epinephrine was 193 +/- 42 pg/ml and norepinephrine 584 +/- 111 pg/ml. During AF, CVR was higher (1.16 +/- 0.11 RU, p less than 0.0005), whereas CBF (92 +/- 9 ml/min X 100 g, p less than 0.001) and coronary sinus oxygen saturation (24 +/- 2%, p less than 0.0025) were lower than during atrial pacing. When AF was induced, epinephrine increased to 333 +/- 98 pg/ml (p less than 0.05) and norepinephrine to 1,005 +/- 214 pg/ml (p less than 0.005). The large increase in plasma catecholamines suggested an activation of the sympathoadrenal system during AF. In addition, the alpha-receptor blocker phenoxybenzamine (10 mg/kg, intravenously) abolished the differences in CVR, CBF and oxygen saturation between AF and atrial pacing. The data suggest that the decrease in CBF and increase in CVR during experimentally induced AF are caused by coronary vasoconstriction, mediated by sympathetic activation of alpha receptors in the coronary vascular bed.     

Halving the volume of AnaConDa: initial clinical experience with a new small-volume anaesthetic reflector in critically ill patients—a quality improvement project

AnaConDa-100 ml (ACD-100, Sedana Medical, Uppsala, Sweden) is well established for inhalation sedation in the intensive care unit. But because of its large dead space, the system can retain carbon dioxide (CO₂) and increase ventilatory demands. We therefore evaluated whether AnaConDa-50 ml (ACD-50), a device with half the internal volume, reduces CO₂ retention and ventilatory demands during sedation of invasively ventilated, critically ill patients. Ten patients participated in this cross-over protocol. After sedation with isoflurane via ACD-100 for 24 h, the 5-h observation period started. During the first hour, ACD-100 was used; for the next 2 h, ACD-50; and for the last 2 h, ACD-100 was used again. Sedation was titrated to Richmond Agitation and Sedation Scale (RASS) score ??3 to ??4 and a processed electroencephalogram (Narcotrend Index, Narcotrend-Gruppe, Hannover, Germany) was recorded. Minute ventilation, CO₂ elimination, and isoflurane consumption were compared. All patients were deeply sedated (Narcotrend Index, mean?±?SD: 38?±?10; RASS scores ??3 to ??5) and breathed spontaneously with pressure support throughout the observation period. Infusion rates of isoflurane and opioid, either remifentanil or sufentanil, as well as ventilator settings were unchanged. Minute ventilation and end-tidal CO₂ were significantly reduced with the ACD-50, respiratory rate remained unchanged, and tidal volume decreased by 66?±?43 ml. End-tidal isoflurane concentrations were also slightly reduced while haemodynamic measures remained constant. The ACD-50 reduces the tidal volume needed to eliminate carbon dioxide without augmenting isoflurane consumption.     

Neuronal activity regulated pentraxin (narp) and GluA4 subunit of AMPA receptor may be targets for fluoxetine modulation

Fluoxetine is the foremost prescribed antidepressant. Drugs acting on monoaminergic system may also regulate glutamatergic system. Indeed, the investigation of proteins associated with this system, such as Narp (neuronal activity-dependent pentraxin) and GluA4 subunit of AMPA receptor may reveal poorly explored modulations triggered by conventional antidepressants. This study aimed to uncover neurochemical mechanisms underlying the chronic fluoxetine treatment, mainly by evaluating these protein targets in the prefrontal cortex and in the hippocampus. Mice received a daily administration of fluoxetine (0.1, 1 or 10 mg/kg, p.o.) or potable water (vehicle group) for 21 days. These animals were submitted to the forced swim test (FST) to verify antidepressant-like responses and the open-field test (OFT) to assess locomotor activity. Modulation of signaling proteins was analyzed by western blot. Chronic treatment with fluoxetine (1 and 10 mg/kg) was effective, since it reduced the immobility time in the FST, without altering locomotor activity. Fluoxetine 10 mg/kg increased CREB phosphorylation and BDNF expression in the prefrontal cortex and hippocampus. Noteworthy, in the hippocampus fluoxetine also promoted Akt activation and augmented Narp expression. In the prefrontal cortex, a significant decrease in the expression of the GluA4 subunit and Narp were observed following fluoxetine administration (10 mg/kg). The results provide evidence of novel molecular targets potentially involved in the antidepressant effects of fluoxetine, since in mature rodents Narp and GluA4 are mainly expressed in the GABAergic parvalbumin-positive (PV+) interneurons. This may bring new insights into the molecular elements involved in the mechanisms underlying the antidepressant effects of fluoxetine.