Early growth response-1-dependent apoptosis is mediated by p53

The early growth response-1 (EGR-1) protein is an anti-proliferative signal for certain tumor cells and is required for apoptosis induced by stimuli that elevate intracellular Ca2+. We present evidence that EGR-1 transactivates the promoter of the p53 gene and up-regulates p53 RNA and protein levels. Inhibition of p53 function with dominant-negative p53 mutants abrogates EGR-1-dependent apoptosis. These findings establish a direct functional link between EGR-1 and the p53-mediated cell death pathway and suggest that mutant forms of p53 in tumor cells may provide resistance to the anti-proliferative effects of EGR-1.     

Effect of angiotensin-converting enzyme inhibitors on the power spectrum of heart rate variability in post-myocardial infarction patients

BACKGROUND: Heart rate variability (HRV) time and frequency domain indices are strong predictors of malignant arrhythmias and sudden cardiac death. The effect of various angiotensin-converting enzyme (ACE) inhibitors on HRV in patients with acute myocardial infarction (AMI) has not been studied. METHODS: Ninety patients with uncomplicated AMI (age range 39-75 years, median 61 years) were assigned randomly to six groups of 15 patients each. They were treated with placebo or one of the following ACE inhibitors for 30 days: captopril, cilazapril, enalapril, lisinopril or quinapril. HRV was assessed 3 days after the onset of AMI (baseline), and 30 days after treatment. Fifteen patients with stable coronary artery disease and 15 healthy volunteers, age- and sex-matched with AMI patients, served as controls. RESULTS: At baseline, time and frequency domain HRV indices in the AMI groups were equally less than those in patients with stable coronary artery disease and normal volunteers. Compared with placebo, quinapril, lisinopril and captopril changed frequency domain HRV indices 30 days after initiation of treatment, indicating an increase in vagal tone, whereas enalapril and cilazapril had no significant effect on these indices. Most of the time domain HRV indices 30 days after initiation of treatment increased significantly in all patients treated with ACE inhibitors, but remained unchanged in the placebo group. Frequency domain and time domain HRV indices 30 days after treatment in the quinapril group did not differ statistically from those in patients with stable coronary artery disease, but were less than those in normal volunteers. CONCLUSIONS: Quinapril, lisinopril and captopril improved frequency domain HRV indices related to vagal tone, whereas cilazapril and enalapril had no effect on these indices. This influence of some ACE inhibitors on HRV may be beneficial in reducing the risk for sudden death in post-myocardial infarction patients.     

Synthesis and 32P-postlabeling/high-performance liquid chromatography separation of diastereomeric 1,N2-(1,3-propano)-2'-deoxyguanosine 3'-phosphate adducts formed from 4-hydroxy-2-nonenal

4-Hydroxy-2-nonenal (HNE), a major electrophilic byproduct of lipid peroxidation, is mutagenic and cytotoxic. The two pairs of HNE-derived diastereomeric 1,N2-propanodeoxyguanosine 3'-monophosphate adducts were synthesized from reaction of HNE with 2'-deoxyguanosine 3'-monophosphate. After HPLC separation, these adducts were characterized by UV-visible absorption and negative ion electrospray ionization MS/MS analysis. To further characterize the structures, these adducts were dephosphorylated to the corresponding HNE-modified deoxyguanosine adducts and their HPLC retention times and UV spectra were compared with those of the synthetic standards prepared from reaction of HNE with 2'-deoxyguanosine. Separation of these adducts by 32P-postlabeling/HPLC was developed. Reaction of HNE with calf thymus DNA resulted in only one pair of diastereomeric adducts, with one adduct predominantly formed with a modification level of 1.2 +/- 0.5 adducts/10(7) nucleotides.     

Anomalous pulmonary venous return in the staged palliation of functional univentricular heart defects

BACKGROUND: Bidirectional cavopulmonary shunt and Fontan repair are now commonly performed in patients with a variety of forms of complex single ventricle, including those with anomalies of systemic, pulmonary, or systemic and pulmonary venous return. These anomalies are ideally dealt with during bidirectional cavopulmonary shunt, thereby minimizing the complexity of the eventual Fontan procedure. METHODS AND RESULTS: Between March 1990 and March 1997, 32 patients with functional single ventricle and anomalous pulmonary venous return underwent operation at our institution. Five of 25 patients who underwent neonatal palliation died in the early postoperative period, all of whom had obstructed anomalous pulmonary venous return. Twenty-one patients have undergone bidirectional cavopulmonary shunt, including 7 in whom this was the primary palliative procedure. There was one early and two late deaths after the bidirectional Glenn procedure, two in patients with asplenia syndrome and none in patients with previously obstructed pulmonary venous return. Seven patients have undergone Fontan completion, 5 with an extracardiac conduit. There was one early death and one take-down to a classic Glenn shunt, both in patients who did not undergo the extracardiac conduit Fontan operation. CONCLUSIONS: Anomalous pulmonary venous return can significantly complicate the management of the single-ventricle patient, with the major impact on survival coming in the neonatal period. Palliation with the aim of performing an extracardiac conduit Fontan procedure allows greater latitude and more streamlined management in this group of patients.     

Neonatal hyperinsulinism

Hyperinsulinism is the most frequent cause of severe, persistent hypoglycemia in neonates and young infants. Timely diagnosis and aggressive treatment are necessary to prevent long-term neurologic sequelae. This article explores the latest advances in the understanding of the pathophysiology of this disorder at the molecular and cellular level. The clinical features, hallmarks for diagnosis, and various treatment options are discussed.     

The N-methyl-D-aspartate (NMDA) receptor is postsynaptic to substance P-containing axon terminals in the rat superficial dorsal horn

Cell differentiation often involves changes in cell polarity. In this study we show that neuroepithelial cells, the progenitors of all neurons and macroglial cells of the vertebrate central nervous system, downregulate the polarized delivery to the apical and basolateral plasma membrane domains during development. Upon infection of the neuroepithelium of mouse embryos with fowl plague virus (FPV), polarized delivery of the viral envelope hemagglutinin, an apical marker, occurred at the neural plate stage (E8), but was downregulated at the open neural tube stage (E9). Upon infection with vesicular stomatitis virus, the viral envelope G protein, a basolateral marker, showed an unpolarized delivery not only at the open neural tube stage, but already at the neural plate stage. These results show that a progressive downregulation of plasma membrane polarity of neuroepithelial cells precedes neural tube closure and the onset of neurogenesis.     

Intracellular routes and selective retention of antigens in mildly acidic cathepsin D/lysosome-associated membrane protein-1/MHC class II-positive vesicles in immature dendritic cells

Immature dendritic cells (DC) use both macropinocytosis and mannose receptor-mediated endocytosis to internalize soluble Ags efficiently. These Ags are ultimately presented to T cells after DC maturation and migration into the lymph nodes. We have previously described the immortalized myeloid cell line FSDC as displaying the characteristics of early DC precursors that efficiently internalize soluble Ags. To describe the different routes of Ag uptake and to identify the Ag retention compartments in FSDC, we followed the intracellular fate of FITC-coupled OVA, dextran (DX), transferrin, and Lucifer Yellow using flow cytometry, confocal microscopy, and immunoelectron microscopy. OVA and DX gained access into macropinosomes and early endosomes. DX was preferentially sorted into endosomal compartments, while most of the OVA entered macropinosomes via fluid phase uptake. We found a long-lasting retention of DX and OVA of up to 24 h. After 6 h of chase, these two molecules were concentrated in common vesicular compartments. These retention compartments were distinct from endosomes and lysosomes; they were much larger, only mildly acidic, and lacked the small GTP binding protein rab7. However, they were positive for lysosome-associated membrane protein-1, the protease cathepsin D, and MHC class II molecules, thus representing matured macropinosomes. These data suggest that the activity of vacuolar proteases is reduced at the mildly acidic pH of these vesicles, which explains their specific retention of an Ag. The retention compartments might be used by nonlymphoid tissue DC to store peripheral Ags during their migration to the lymph node.     

The effects of a potassium citrate, cetylpyridinium chloride, sodium fluoride mouthrinse on dentine hypersensitivity, plaque and gingivitis. A placebo-controlled study

Home-use studies on dentine hypersensitivity have most commonly involved toothpastes and rarely have mouthrinses been employed. Potassium and/or fluoride toothpastes have been shown effective in the treatment of dentine hypersensitivity. The aim of this study was to evaluate the effectiveness of a total formulation, containing potassium citrate, sodium fluoride, cetylpyridinium chloride mouthrinse compared to the base rinse minus actives in the reduction of dentine hypersensitivity. The study was a randomised placebo controlled, double blind parallel design. At a screening visit, 90 adult subjects were recruited who were suffering from dentine hypersensitivity from at least 1 tooth responding to tactile stimulation (45gm pressure) and had at least 2 teeth responding to evaporative stimulation (air blast). During a washout period of 28 days and throughout the 56-day study period, subjects used a soft filament toothbrush and standard fluoride toothpaste. At baseline (day 1), threshold sensitivities to incremental tactile (10 g to 70 g) and evaporative stimuli were determined. Gingival health was assessed by recording bleeding on probing at 25 g pressure at mesiobuccal and lingual sites. Plaque scores from buccal and lingual surfaces of disclosed teeth were also measured. Subjects then used the prescribed rinse, 10 ml for at least 30 s after brushing 2x per day returning on days 28 and 56 for rescoring of sensitivity, gingivitis and plaque. Data from 88 subjects were used with the intent to treat analyses and 83 in the completely evaluable analyses. Groups were well balanced for demographic data and product returns suggested good compliance. Both groups showed highly significant improvements in tooth sensitivity. The pattern was for greater improvement in the test compared to the control group (statistically significant for the plaque score), whereas bleeding scores, already low, showed no change in either group. By definition, the placebo rinse could not have exerted any therapeutic action; the study therefore provides clear direct evidence as to the magnitude (30%-40%) of the little studied, but assumed, placebo response in dentine hypersensitivity trials.     

The extent of bone resection in osteomyelitis of the chest wall

The experience in treatment of 40 patients with osteomyelitis and chondritis of the bones of thoracic wall is presented. 39 patients (of 40) underwent surgery with due regard to an adequate extent of resection within so-called borders of intact tissues. Critical analysis of literature and authors' own experience made it possible to establish strict borders of resection of damaged bones in this disease of thoracic wall frame and to obtain good results of combined treatment in patients over 50 years. Complete removal of chondral tissues and resection of bones within the area of probably normal anatomic formation of the bone, irrespective of the origin of osteomyelitis and chondritis (hematogenous, exogenous), have promoted recovery of the patients. There were no relapses during 1-7 year period.