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.     

Antihypertensive effects of captopril and saralasin in essential and renal hypertension

The antihypertensive effect of captopril and its mechanism of action were studied in patients with essential and renal hypertension. In mild essential hypertension (n = 12), during monotherapy with captopril (50 to 450 mg, 4 to 12 weeks) blood pressure was normalized in seven, improved in two and remained unchanged in three patients, plasma levels of active and acid-activatable inactive renin significantly increased and angiotensin II decreased, whereas no consistent changes in urinary kallikrein excretion occurred. In severe renal (n = 14) and essential (n = 9) hypertension, blood pressure was normalized in eight (seven with renal hypertension), improved in seven and unchanged in eight patients, when captopril (50 to 450 mg, 3 to 15 months) was added to the antihypertensive medication. In one patient with stenosis in a transplanted renal artery reversible renal failure occurred during captopril therapy possibly because of a steep initial decrease in blood pressure, although a toxic effect of the drug cannot be excluded. In another series of 12 renal and 8 essential hypertensive patients, a significant correlation between the acute effect of captopril (within 90 minutes) and saralasin on blood pressure was demonstrated (r = 0.71, p < 0.001). The change in blood pressure after either drug was significantly related to the initial plasma renin concentration.In conclusion, captopril sems to be an effective antihypertensive agent in essential and renal hypertension. Renal function should be monitored during captopril therapy. Our studies suggest that captopril decreases blood pressure by inhibiting the vasopressor action of the renin-angiotensin system.     

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.     

De novo missense mutations in the NAA10 gene cause severe non-syndromic developmental delay in males and females

Recent studies revealed the power of whole-exome sequencing to identify mutations in sporadic cases with non-syndromic intellectual disability. We now identified de novo missense variants in NAA10 in two unrelated individuals, a boy and a girl, with severe global developmental delay but without any major dysmorphism by trio whole-exome sequencing. Both de novo variants were predicted to be deleterious, and we excluded other variants in this gene. This X-linked gene encodes N-alpha-acetyltransferase 10, the catalytic subunit of the NatA complex involved in multiple cellular processes. A single hypomorphic missense variant p.(Ser37Pro) was previously associated with Ogden syndrome in eight affected males from two different families. This rare disorder is characterized by a highly recognizable phenotype, global developmental delay and results in death during infancy. In an attempt to explain the discrepant phenotype, we used in vitro N-terminal acetylation assays which suggested that the severity of the phenotype correlates with the remaining catalytic activity. The variant in the Ogden syndrome patients exhibited a lower activity than the one seen in the boy with intellectual disability, while the variant in the girl was the most severe exhibiting only residual activity in the acetylation assays used. We propose that N-terminal acetyltransferase deficiency is clinically heterogeneous with the overall catalytic activity determining the phenotypic severity.     

Non-Compaction-Kardiomyopathie

Isolated non-compaction of the ventricular myocardium (INVM), also known as left ventricular hypertrabeculation or spongy myocardium, belongs to the "unclassified" cardiomyopathies according to the World Health Organization. The main characteristic of this entity is a prominent trabeculation of the left ventricle with deep intertrabecular recesses communicating with the ventricular cavity. The pathomechanism of INVM is thought to be an arrest in cardiac myogenesis with persistence of embryonic myocardial morphology. The most frequent clinical manifestations include congestive heart failure, ventricular arrhythmias and systemic thromboembolic events. The therapy of INVM comprises standard medical therapy for heart failure.