The proliferation marker pKi-67 organizes the nucleolus during the cell cycle depending on Ran and cyclin B

The proliferation marker pKi-67 ('Ki-67 antigen') is commonly used in clinical and research pathology to detect proliferating cells, as it is only expressed during cell-cycle progression. Despite the fact that this antigen has been known for nearly two decades, there is still no adequate understanding of its function. This study has therefore identified proteins that interact with pKi-67, using a yeast two-hybrid system. A mammalian two-hybrid system and immunoprecipitation studies were used to verify these interactions. Among other cell-cycle regulatory proteins, two binding partners associated with the small GTPase Ran were identified. In addition, DNA-structural and nucleolus-associated proteins binding to pKi-67 were found. Moreover, it was demonstrated that the N-terminal domain of pKi-67 is capable of self-binding to its own repeat region encoded by exon 13. Since RanBP, a protein involved in the transport of macromolecules over the nuclear lamina, was found to be a binding partner, a possible effect of pKi-67 on the localization of cell-cycle regulatory proteins was proposed. To test this hypothesis, a tetracycline-responsive gene expression system was used to induce the pKi-67 fragments previously used for the two-hybrid screens in HeLa cells. Subsequent immunostaining revealed the translocation of cyclin B1 from cytoplasm to nucleoli in response to this expression. It is suggested that pKi-67 is a Ran-associated protein with a role in the disintegration and reformation of the nucleolus and thereby in entry into and exit from the M-phase.     

Predictors of survival in unselected patients with acute myocardial infarction requiring continuous catecholamine support

BACKGROUND: Several predictors of survival have been described in selected subgroups of patients suffering from acute myocardial infarction. However, data on unselected patients with acute myocardial infarction and cardiogenic shock, including patients with out-of hospital cardiac arrest, are missing. We aimed to assess predictors of survival for an unselected cohort of patients representative of clinical practice who experienced acute myocardial infarction and required continuous catecholamine support for circulatory failure. METHODS: The study was performed at a 2000 bed university hospital. All consecutive patients admitted to our emergency department with acute myocardial infarction were prospectively enrolled in a clinical trial from 1993 to 2000. DESIGN: A retrospective cohort study was performed on patients with myocardial infarction requiring catecholamine support within the first 24 h. Primary endpoint was in-hospital mortality. RESULTS: The analysis was carried out on 262 patients, 189 men (72%), median age 65 years (IQR 53-73). Out-of-hospital cardiac arrest was reported in 47% (122/262). In-hospital mortality was 53% (138/262). Survivors as compared to non-survivors exhibited significant differences with respect to age (60 vs. 68 years, P<0.0001), systolic and diastolic blood pressure on admission (110 vs. 102 mmHg, P=0.01 and 64 vs. 58 mmHg, P=0.006, respectively), initial blood serum lactate (6.8 vs. 8.3, P=0.01), peak CKMB level (93 vs. 138 U/l, P=0.005), use of adrenaline (epinephrine) (38 vs. 68%, P<0.0001) and any attempt of revascularisation (76 vs. 63%, P=0.03). In a multivariate model younger age [OR 1.06 (CI 1.03-1.10), P<0.001], no use of adrenaline [OR 2.63 (CI 1.35-5.26) P=0.005] and lower peak CKMB [OR 1.01 (CI 1.01-1.01), P<0.0001] were independently associated with in-hospital survival. CONCLUSION: In unselected patients including CPR survivors with acute myocardial infarction requiring continuous catecholamine support, younger age, the absence of continuous adrenaline administration and a lower peak CKMB were independently associated with increased in-hospital survival.     

Surgical versus endovascular treatment of acute thoracic aortic rupture: a single-center experience

BACKGROUND: Surgical management of acute thoracic aortic ruptures is controversial, especially in patients with preexisting comorbidities; associated mortality and paraplegia rates remain high. It was our objective to evaluate whether treating these patients acutely with endovascular stent grafts would improve their outcome. METHODS: From November 1999 to February 2002 a total of 54 patients, age 28 to 83 years, were admitted to our institution with an acute rupture of the thoracic aorta (24 ruptured aneurysms, 14 perforated type B dissections, 16 traumatic ruptures). Twenty-eight patients were managed surgically using cardiopulmonary bypass (group 1), and 26 patients were treated acutely with an endovascular stent graft (group 2). The resuscitation protocol and interval from onset of symptoms to treatment was comparable in both groups. Medical records were reviewed for prehospitalization and emergency department data, operative findings, and outcomes. RESULTS: There were 5 of 28 deaths (17.8%) in the surgical group and 1 of 26 deaths (3.8%) in the endovascular group. In the surgical group 1 of 28 patients (3.6%) exhibited paraplegia; there were no cases of paraplegia in the endovascular group. There were 4 of 28 cases (14.3%) of renal failure in group 1 and 1 of 26 (3.8%) in group 2. In group 1, 8 patients (28.6%) required mechanical ventilation for more than 48 hours; there were 2 of 26 patients (7.7%) in group 2 with this ventilatory requirement. Three patients required a repeat thoracotomy for hemorrhage in the surgical group. There were two access failures in the endovascular group. CONCLUSIONS: In the treatment of acute ruptures of the thoracic aorta, the immediate outcome of patients treated with endovascular stent grafts appears to be better than with management by conventional surgical repair.     

Emergent endovascular stent grafting for perforated acute type B dissections and ruptured thoracic aortic aneurysms

BACKGROUND: The purpose of our study was to demonstrate the effectiveness of endovascular stent grafts in the treatment of acutely ruptured thoracic aortic aneurysms and type B dissections as an alternative to the conventional surgical approach in an emergency setting. METHODS: From January 2001 to October 2001, we deployed 11 emergent endovascular stent grafts into the thoracic aorta. We treated seven ruptured aortic aneurysms and four acutely perforated type B dissections. Aortic rupture was confirmed preoperatively by spiral computed tomography. In all cases, hemothorax was present. The average interval from onset of symptoms to treatment was 28.5 hours. We used nine Talent and two Excluder stent grafts. RESULTS: Deployment of the stent grafts was successful in nine cases. There were two cases of access failure due to small caliber of iliac arteries, and 1 of these patients died shortly after the procedure was abandoned, At 12 months of follow-up, there were no cases of paraplegia, stent migration, or endoleaks. There was, however, one temporary renal failure, and 2 patients required mechanical ventilation for more than 48 hours. CONCLUSIONS: Our experiences with emergency endovascular stent grafting show that the procedure is technically feasible, with less morbidity and mortality than conventional open surgery, in high-risk patients.     

Regulation of hairy-cell survival through constitutive activation of mitogen-activated protein kinase pathways

The hairy cells (HCs) of hairy-cell leukemia are intrinsically activated mature clonal B cells. The aims of this study were to gain further insights into the nature of this activation and to assess its importance for the prolonged HC survival in this chronic disease. We show that HCs contain phosphorylated/activated p38 MAPK, JNK and ERK1/ERK2 (ERK1/2). PKC inhibitors increased the activation of p38 and JNK, but reduced the phosphorylation of ERK1/2. Moreover, PKC inhibition resulted in cell death; cell death was also observed when the activation of ERK1/2 in HCs was abrogated with an inhibitor of MEK1/2 activation. In addition to PKC, active Src kinase was also shown to be involved in the maintenance of Raf-independent ERK activation in HCs. During cell culture on a nonadherent surface, ERK phosphorylation was sustained, while phosphorylation of p38 and JNK decreased. This decrease was not observed in HCs cultured on vitronectin (VN), indicating that p38/JNK activation is probably a consequence of in vivo HC interaction with VN present in abundance in the red pulp of the spleen. Taken together, these results suggest that active p38/JNK make HCs susceptible to apoptosis, but the cells are effectively rescued by ERK activation involving constitutively active PKC and Src. These findings are relevant for the understanding of the prolonged cell survival of HCs and their selective sensitivity to some chemotherapeutic agents.     

Reporting adverse drug reactions on a geriatric ward: a pilot project

OBJECTIVE: To test a method for registration of adverse drug reactions (ADRs) resulting in hospital admission and of ADRs occurring during hospital stay. Spontaneous reporting was compared with data from patient interview. METHODS: Spontaneous reporting of ADRs by nurses and physicians, as well as patient interviews by pharmacists. This pilot project was carried out in the geriatric ward of the Ghent University Hospital over a period of 8 months in order to develop suitable registration forms and to test feasibility. Causality, severity, type and level of intervention of the reported ADRs were analysed. Reports from physicians and nurses were compared with the data obtained by patient interviews. RESULTS: During the 8 months, for 168 patients, 12 spontaneous reports were received from physicians and nurses. Fifty-six of these patients were interviewed and 32 ADRs were reported. Only 2 ADRs detected by patient interview were also reported spontaneously. The interviews of the 56 geriatric patients indicated that 20% of them were admitted to the hospital because of an ADR. ADRs occurred during hospital stay in another 20% of those patients. CONCLUSION: Spontaneous reporting by physicians and nurses revealed considerably fewer ADRs than patient interview by pharmacists. Physicians and nurses reported the more serious ADRs that occurred during hospital stay, whereas the interviews revealed more ADRs that caused hospital admission. Our data confirm that ADRs are an important cause of hospital admission of geriatric patients and occur frequently during their hospital stay.     

Loss of heterozygosity of DPC4 tumor suppressor gene in human sporadic colon cancer

We investigated the prevalence of DPC4 loss of heterozygosity in sporadic colorectal cancer. Thirty-six cases of human sporadic colon carcinoma and corresponding normal tissue samples were examined to evaluate loss of heterozygosity at the DPC4 tumor suppressor locus using variable nucleotide tandem repeat (VNTR) analysis and three polymorphic markers. From 36 analyzed samples 35 (97%) were heterozygous or informative. Loss of heterozygosity at the DPC4 locus was detected in 18 (51%) of informative tumor DNAs. The DPC4 LOH was more frequent in smaller tumors (<5 cm) than in larger ones. There was no correlation between DPC4 LOH and age or sex of patients. There was a negative correlation between DPC4 LOH and histological grade or Dukes' stage of tumors, but without statistic significance. Observed results are in agreement with the view that malignant progression is consequence of many genetic changes. It can be concluded that inactivation of the DPC4 gene plays a role in a multistep process of outgrowth and progression of colon cancer.     

The role of ultrasonography in the assessment of renal function in the elderly

BACKGROUND: Ageing is associated with a progressive loss of renal mass and kidney length and a decline in glomerular filtration rate (GFR). This study evaluated a possible correlation between renal function and kidney size measured by ultrasonography (US), and whether the latter helps estimate GFR in the elderly. METHODS: Twenty-five medically stable elderly patients (mean age 85 +/- 5 yrs) were examined in a geriatric ward at a university hospital. Blood samples were taken to determine serum creatinine (Cr) levels. On the same day, 51chromium ethylenediamine tetraacetic acid (51Cr-EDTA) clearance was performed as the gold standard of GFR. US measured kidney length, transverse and anteroposterior dimensions. RESULTS: Serum Cr (r=-0.67; p=0.0002), Cockcroft-Gault formula (r=0.82; p<0.0001), absolute length (r=0.51; p=0.008) and volume kidney (r=0.46; p=0.02) correlated significantly with GFR. After receiver operating curve (ROC) analysis, length was less specific than sensitive in detecting renal impairment. Adding length to the Cockcroft-Gault formula did not improve GFR estimation (p=0.44). In contrast, adding length to serum Cr levels improved GFR estimation (p=0.015). CONCLUSION: In the elderly, kidney length and volume significantly correlated with GFR. However, length has a low specificity in predicting renal impairment. Therefore, in clinical practice, serum Cr levels and calculated Cr clearance are more useful in predicting renal impairment. However, normal kidney length can help to exclude renal impairment in the elderly at risk of GFR underestimation by a calculated Cr clearance.     

Alcohol promotes dopamine release in the human nucleus accumbens

Microdialysis experiments in rodents indicate that ethanol promotes dopamine release predominantly in the nucleus accumbens, a phenomenon that is implicated in the reinforcing effects of drugs of abuse. The aim of the present study was to test the hypothesis in humans that an oral dose of ethanol would lead to dopamine release in the ventral striatum, including the nucleus accumbens. Six healthy subjects underwent two [(11)C]raclopride PET scans following either alcohol (1 ml/kg) in orange juice or orange juice alone. Subjective mood changes, heart rate, and blood-alcohol levels were monitored throughout the procedure. Personality traits were evaluated using the tridimensional personality questionnaire. PET images were co-registered with MRI and transformed into stereotaxic space. Statistical parametric maps of [(11)C]raclopride binding potential change were generated. There was a significant reduction in [(11)C]raclopride binding potential bilaterally in the ventral striatum/nucleus accumbens in the alcohol condition compared to the orange juice condition, indicative of increased extracellular dopamine. Moreover, the magnitude of the change in [(11)C]raclopride binding correlated with the alcohol-induced increase in heart rate, which is thought to be a marker of the psychostimulant effects of the drug, and with the personality dimension of impulsiveness. The present study is the first report that, in humans, alcohol promotes dopamine release in the brain, with a preferential effect in the ventral striatum. These findings support the hypothesis that mesolimbic dopamine activation is a common property of abused substances, possibly mediating their reinforcing effects.