Modulation of Mcl-1 sensitizes glioblastoma to TRAIL-induced apoptosis.

Glioblastoma (GBM) is the most aggressive form of primary brain tumour, with dismal patient outcome. Treatment failure is associated with intrinsic or acquired apoptosis resistance and the presence of a highly tumourigenic subpopulation of cancer cells called GBM stem cells. Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) has emerged as a promising novel therapy for some treatment-resistant tumours but unfortunately GBM can be completely resistant to TRAIL monotherapy. In this study, we identified Mcl-1, an anti-apoptotic Bcl-2 family member, as a critical player involved in determining the sensitivity of GBM to TRAIL-induced apoptosis. Effective targeting of Mcl-1 in TRAIL resistant GBM cells, either by gene silencing technology or by treatment with R-roscovitine, a cyclin-dependent kinase inhibitor that targets Mcl-1, was demonstrated to augment sensitivity to TRAIL, both within GBM cells grown as monolayers and in a 3D tumour model. Finally, we highlight that two separate pathways are activated during the apoptotic death of GBM cells treated with a combination of TRAIL and R-roscovitine, one which leads to caspase-8 and caspase-3 activation and a second pathway, involving a Mcl-1:Noxa axis. In conclusion, our study demonstrates that R-roscovitine in combination with TRAIL presents a promising novel strategy to trigger cell death pathways in glioblastoma.

Atomic arrangements at metal surfaces.

The termination of a solid induces changes in the locations of the outermost atoms of the solid. The changes can be minor or as dramatic as the rearrangement of the atoms into a different crystallographic group. Surface crystallography studies have determined that all surfaces are altered by forces induced at the solid-vacuum interface. At the least, the outermost atomic layers are displaced away from positions that they would have had in the bulk environment. Results from experimental and theoretical investigations for the Al(110) surface are discussed to illustrate present understanding of the surface atomic displacements. Some effects that the truncation- induced forces have on the surfaces of binary metal alloys are also discussed.

Stimulus quality affects expression of the acoustic startle response and prepulse inhibition in mice.

The relationship between stimulus intensity and startle response magnitude (SIRM) can assess the startle reflex and prepulse inhibition (PPI) with advantages over more commonly used methods. The current study used the SIRM relationships in mice to determine differences between white noise and pure tone (5 kHz) stimuli. Similarly to rats, the SIRM relationship showed a sigmoid pattern. The SIRM-derived reflex capacity (RMAX) and response efficacy (slope) of the white noise and pure tone stimuli in the absence of prepulses were equivalent. However, the pure tone startle response threshold (DMIN) was increased whereas the stimulus potency (1/ES50) was decreased when compared to white noise. Prepulses of both stimulus types inhibited RMAX and increased DMIN, but the white noise prepulses were more effective. Both stimulus intensity gating and motor capacity gating processes are shown to occur, dependent on prepulse intensity and stimulus onset asynchrony. Prepulse intensities greater than 10 dB below the startle threshold appear to produce PPI via stimulus intensity gating, whereas a motor capacity gating component appears at prepulse intensities near to the startle threshold.

Are ECG abnormalities in Noonan syndrome characteristic for the syndrome?

Of all patients with Noonan syndrome, 50-90% have one or more congenital heart defects. The most frequent occurring are pulmonary stenosis (PS) and hypertrophic cardiomyopathy. The electrocardiogram (ECG) of a patient with Noonan syndrome often shows a characteristic pattern, with a left axis deviation, abnormal R/S ratio over the left precordium, and an abnormal Q wave. The objective of this study was to determine if these ECG characteristics are an independent feature of the Noonan syndrome or if they are related to the congenital heart defect. A cohort study was performed with 118 patients from two university hospitals in the United States and in The Netherlands. All patients were diagnosed with definite Noonan syndrome and had had an ECG and echocardiography. Sixty-nine patients (58%) had characteristic abnormalities of the ECG. In the patient group without a cardiac defect (n = 21), ten patients had a characteristic ECG abnormality. There was no statistical relationship between the presence of a characteristic ECG abnormality and the presence of a cardiac defect (p = 0.33). Patients with hypertrophic cardiomyopathy had more ECG abnormalities in total (p = 0.05), without correlation with a specific ECG abnormality. We conclude that the ECG features in patients with Noonan syndrome are characteristic for the syndrome and are not related to a specific cardiac defect. An ECG is very useful in the diagnosis of Noonan syndrome; every child with a Noonan phenotype should have an ECG and echocardiogram for evaluation.

The cardiofaciocutaneous syndrome.

The cardiofaciocutaneous (CFC) syndrome is a condition of sporadic occurrence, with patients showing multiple congenital anomalies and mental retardation. It is characterised by failure to thrive, relative macrocephaly, a distinctive face with prominent forehead, bitemporal constriction, absence of eyebrows, hypertelorism, downward-slanting palpebral fissures often with epicanthic folds, depressed nasal root and a bulbous tip of the nose. The cutaneous involvement consists of dry, hyperkeratotic, scaly skin, sparse and curly hair, and cavernous haemangiomata. Most patients have a congenital heart defect, most commonly pulmonic stenosis and hypertrophic cardiomyopathy. The developmental delay usually is moderate to severe. The syndrome is caused by gain-of-function mutations in four different genes BRAF, KRAS, mitogen-activated protein/extracellular signal-regulated kinase MEK1 and MEK2, all belonging to the same RAS-extracellular signal-regulated kinase (ERK) pathway that regulates cell differentiation, proliferation and apoptosis. The CFC syndrome is a member of a family of syndromes that includes the Noonan and Costello syndromes, presenting with phenotypic similarities. Noonan syndrome is caused by mutations in the protein tyrosine phosphatase SHP-2 gene (PTPN11), with a few people having a mutation in KRAS. Costello syndrome is caused by mutations in HRAS. The protein products of these genes also belong to the RAS-ERK pathway. Thus, the clinical overlap of these three conditions, which often poses a problem of differential diagnosis, is explained by their pathogenetic relatedness.

The DNA helicase activity of BLM is necessary for the correction of the genomic instability of bloom syndrome cells.

Bloom syndrome (BS) is a rare autosomal recessive disorder characterized by growth deficiency, immunodeficiency, genomic instability, and the early development of cancers of many types. BLM, the protein encoded by BLM, the gene mutated in BS, is localized in nuclear foci and absent from BS cells. BLM encodes a DNA helicase, and proteins from three missense alleles lack displacement activity. BLM transfected into BS cells reduces the frequency of sister chromatid exchanges and restores BLM in the nucleus. Missense alleles fail to reduce the sister chromatid exchanges in transfected BS cells or restore the normal nuclear pattern. BLM complements a phenotype of a Saccharomyces cerevisiae sgs1 top3 strain, and the missense alleles do not. This work demonstrates the importance of the enzymatic activity of BLM for its function and nuclear localization pattern.

Platinum(iv) oxaliplatin-peptide conjugates targeting memHsp70+ phenotype in colorectal cancer cells.

Novel Pt(iv) tumour penetrating peptide (TPP) conjugates are reported. They are the first example of metallodrugs to target a membrane bound heat shock protein 70 positive (memHSP70+) phenotype in cancer cells. The conjugates exhibit superior cytotoxicity as compared to oxaliplatin alone in Pt resistant colorectal cancer cells with relatively high memHSP70+ expression. Substitution of TPP in Pt(iv) peptide conjugates with scrambled peptide (ScP) essentially abolishes the observed cytotoxicity.

Influence of prolactin and growth hormone on rat mammary tumors induced by N-nitrosomethylurea.

The effects of hypophysectomy and prolactin-suppressing drugs on the growth of mammary tumors induced in Sprague-Dawley rats by N-nitrosomethylurea and dimethylbenz(a)anthracene were compared. The influence of ovine prolactin and growth hormone administration on N-nitrosomethylurea-induced tumors was also studied in hypophysectomized animals. After hypophysectomy, all 13 tumors induced in 13 rats by N-nitrosomethylurea underwent regression, as did ten of 12 induced by dimethylbenz(a)anthracene. There were no new tumors. Pergolide mesylate, a long-acting ergoline derivative, was given in a dose of 80 micrograms twice daily by s.c. injection for 28 days. Only three of 12 N-nitrosomethylurea-induced tumors regressed, while four became static. However, only two new tumors developed in the 12 pergolide-treated rats, compared to 11 in the 12 untreated controls. Bromocriptine mesylate, at ten times the pergolide dose, was even less effective; one of 16 tumors regressed, two became static, and eight new tumors appeared in the 16 rats. In contrast, eight of 12 dimethylbenz(a)anthracene-induced tumors regressed during pergolide therapy, two became static, and there was only one new tumor among the 12 rats. Prolactin, 1 mg twice daily for 7 days by s.c. injection, was given to another eight rats bearing 11 N-nitrosomethylurea-induced tumors, commencing 7 days after hypophysectomy. Regression of five tumors borne by four rats was reversed but resumed when treatment was stopped. Regression of five tumors in the other four animals was arrested without regrowth; the sixth became inpalpable. All of these six grew rapidly when growth hormone, 2 mg twice daily, was administered in addition to prolactin.

Accuracy of combined two-dimensional echocardiography and continuous wave Doppler recordings in the estimation of pressure gradient in right ventricular outlet obstruction.

Fifteen patients (median age 8.5 years) with fixed right ventricular outflow tract obstruction were evaluated by two-dimensional echocardiographically directed continuous wave Doppler ultrasound within 24 hours of cardiac catheterization. Pulmonary artery blood velocity measurements were determined from a real time spectral display of pulmonary artery flow profile and converted to pressure drop utilizing a modified Bernoulli equation. Use of both parasternal and subcostal imaging permitted more accurate detection of maximal flow velocity than did use of either approach alone. Gradients estimated from Doppler recordings correlated well with those measured at cardiac catheterization (correlation coefficient = 0.95, standard error of the estimate = 7.9 mm Hg) with a trend to slight underestimation of gradient in more severe obstruction. In three patients with combined valvular and subvalvular stenosis and one patient with right ventricular outlet obstruction due totally to a ventricular septal aneurysm, Doppler estimation of gradient provided an accurate assessment of total right ventricular-pulmonary artery gradient. Thus, continuous wave Doppler ultrasound combined with two-dimensional echocardiography provides a reliable noninvasive method of estimating pressure gradient in patients with right ventricular outflow tract obstruction.

Ventriculocoronary connections in hypoplastic right heart syndrome: autopsy serial section study of six cases.

Myocardial sinusoids communicating with the coronary systems occur in pulmonary atresia with intact ventricular septum. To test the hypothesis that the extent of ventriculocoronary connections correlates with the degree of right ventricular outflow obstruction as evidenced by clinical, angiographic and gross anatomic findings, a serial section study of six human autopsy hearts representing a spectrum of hypoplastic right heart was undertaken. Slides were evaluated for the presence and extent of ventriculocoronary connections, associated developmental abnormalities and secondary changes in the ventricular walls. Whereas extensive blind-ended deep sinusoids were a feature of all five cases with unrelieved obstruction, ventriculocoronary connections were identified in three. Changes that suggested ongoing remodeling provide new evidence for the postnatal temporal evolution of these anomalous communications. The regional distribution of myofiber disarray in hypoplastic right heart supports the concept that vascularization parallels myocardial organization in the developing human heart.

Anomalous left coronary artery from the pulmonary artery: significance of associated intracardiac defects.

Two patients with anomalous origin of the left main coronary artery from the pulmonary artery had an associated defect (one, critical pulmonary stenosis; the other, ventricular septal defect). They presented with signs and symptoms of the associated defect and the coronary anomaly was unrecognized. Both cases at autopsy lacked the usual large right coronary artery seen with this anomaly. The pathophysiologic features of the combined defects are described, their differences from the isolated anomaly are noted and their relation to surgery is discussed.

Long-term outcome in congenitally corrected transposition of the great arteries: a multi-institutional study.

OBJECTIVES: The purpose of this study was to determine long-term outcome in adults with congenitally corrected transposition of the great arteries (CCTGA), with particular emphasis on systemic ventricular dysfunction and congestive heart failure (CHF). BACKGROUND: Patients with CCTGA have the anatomical right ventricle as their systemic pumping chamber, with ventricular dysfunction and CHF being relatively common in older adults. METHODS: Retrospective analysis of records of 182 patients from 19 institutions were reviewed to determine current status and possible risk factors for systemic ventricular dysfunction and CHF. Factors considered included age, gender, associated cardiac defects, operative history, heart block, arrhythmias and tricuspid (i.e., systemic atrioventricular) regurgitation (TR). RESULTS: Both CHF and systemic ventricular dysfunction were common in groups with or without associated cardiac lesions. By age 45, 67% of patients with associated lesions had CHF, and 25% of patients without associated lesions had this complication. The rates of systemic ventricular dysfunction and CHF were higher with increasing age, the presence of significant associated cardiac lesions, history of arrhythmia, pacemaker implantation, prior surgery of any type, and particularly with tricuspid valvuloplasty or replacement. Aortic regurgitation (a previously unreported problem) was also relatively common in this patient population. CONCLUSIONS: Patients with CCTGA are increasingly subject to CHF with advancing age; this complication is extremely common by the fourth and fifth decades. Tricuspid (systemic atrioventricular) valvular regurgitation is strongly associated with RV (anatomical right ventricle connected to aorta in CCTGA patients; systemic ventricle in CCTGA) dysfunction and CHF; whether it is causative or a secondary complication remains speculative.

Mitral valve prolapse in patients with anorexia nervosa and bulimia.

We studied 43 consecutive individuals with eating disorders (anorexia nervosa and/or bulimia) for the presence of mitral valve prolapse and/or cardiac arrhythmias by physical examination, M-mode and two-dimensional echocardiography, and 24-hour continuous ambulatory electrocardiographic monitoring. Ten of the 43 had findings of mitral valve prolapse on resting cardiac auscultation. Echocardiographic evaluation confirmed the diagnosis of mitral valve prolapse in these ten as well as in six other individuals, giving an overall incidence of 37% (16/43). Similar echocardiographic findings were present in only 4% (1/23) of control individuals. Cardiac arrhythmias other than benign isolated premature extrasystoles were noted in five patients with eating disorder; all five also had echocardiographic findings of mitral valve prolapse. The incidence of mitral valve prolapse appears to be increased in patients with eating disorders. In addition, the arrhythmogenic effects of mitral valve prolapse may present an additional risk factor in these patients.

Protection of the ischaemic myocardium by L-propionylcarnitine: effects on the recovery of cardiac output after ischaemia and reperfusion, carnitine transport, and fatty acid oxidation.

The effects of L-propionylcarnitine on the recovery of cardiac contractile performance after global ischaemia and reperfusion were studied in isolated perfused rat hearts. The addition of either 5.5 or 11 mmol X litre-1 L-propionylcarnitine significantly improved the recovery of cardiac output, left ventricular pressure, and dP/dt after 90 min of ischaemia and 15 min of reperfusion. Myocardial adenosine triphosphate and creatine phosphate concentrations were significantly higher in the L-propionylcarnitine treated hearts than in controls, but the concentrations of long chain acyl carnitine and coenzyme A were unaffected. The protecting effects of L-propionylcarnitine were compared with those of L-carnitine and L-acetylcarnitine. A 11 mmol X litre-1 dose of L-propionylcarnitine and L-acetylcarnitine significantly improved the recovery of cardiac output after 90 min of ischaemia and 15 min of reperfusion, but L-carnitine did not. L-Propionylcarnitine was the most protective agent. The effects of these derivatives on L-3H-carnitine transport and 14C-palmitate oxidation were also measured. All of these derivatives competitively inhibited L-3H-carnitine transport in isolated cardiac myocytes, but L-propionylcarnitine was the most potent. Carnitine and L-propionylcarnitine stimulated palmitate oxidation in the homogenate, whereas L-acetylcarnitine inhibited it. In myocytes only L-propionylcarnitine affected palmitate oxidation. These data show that L-propionylcarnitine protects the ischaemic myocardium. Its protection is greater than that for L-carnitine or L-acetylcarnitine, and the difference in effectiveness may relate to the rate of transport into the cells and the effects on fatty acid utilisation.

Posterior hypothalamic lesions advance the onset of puberty in the female rhesus monkey.

The effects of experimental lesions in the posterior hypothalamus and the anterior hypothalamus on menarche and first ovulation were examined in nonhuman primates. With the aid of x-ray ventriculography, bilateral lesions were made by passing a radiofrequency current through a thermister electrode in the posterior hypothalamus (n = 7) or the anterior hypothalamus (n = 6) of female rhesus monkeys at 18 months of age. Four animals that received sham lesions as well as four normal females of a similar age served as controls. All animals were caged individually and examined daily for vaginal bleeding and sex skin color change. Developmental changes in gonadotropins, ovarian steroids, body weight, and nipple size were monitored throughout the experiments. The time of first ovulation was determined by laparoscopic observation of the newly formed corpus luteum and by the level of circulating progesterone. Histological examination confirmed that the bilateral lesions in the hypothalamus were approximately 2-3 mm in diameter and overlapped midline. Primary sites of posterior hypothalamic lesions included the premamillary area and the posterior nucleus, while the infundibular nucleus and the median eminence were entirely spared. The posterior lesions encroached upon the mamillary nuclei caudally in most cases and upon the ventromedial nucleus rostrally in some cases. Primary sites of anterior hypothalamic lesions included the medial preoptic area, the periventricular preoptic nucleus, and the anterior hypothalamic nucleus. Partial lesions of the diagonal bundle of Broca, the medial preoptic nucleus, and the paraventricular nucleus were also detected. Posterior hypothalamic lesions advanced the ages at menarche (22.2 +/- 1.3 months; P less than 0.001) and first ovulation (40.7 +/- 2.7 months; P less than 0.05) compared to those of control animals (menarche, 30.3 +/- 3.1; first ovulation, 51.2 +/- 3.3 months). The body weight at menarche of these lesioned animals (2.62 +/- 0.11 kg) was smaller (P less than 0.05) than that of controls (3.14 +/- 0.20 kg), but the body weight at first ovulation of lesioned animals (4.36 +/- 0.28 kg) was not different from that of controls (4.57 +/- 0.13 kg). Hormonal and physical changes during maturation, i.e. an increase in circulating estradiol and growth in nipple size before menarche and first ovulation, occurred earlier in the lesioned animals and the growth spurt before first ovulation not only began earlier but also attained mature levels several months earlier than that in control animals.(ABSTRACT TRUNCATED AT 400 WORDS)

Developmental changes in the luteinizing hormone secretory pattern in peripubertal female rhesus monkeys: comparisons between gonadally intact and ovariectomized animals.

Developmental changes in LH release patterns were observed longitudinally in female rhesus monkeys at 10-65 months of age. The average ages of menarche and first ovulation in this experiment (n = 14) were 31.1 +/- 2.6 and 47.0 +/- 2.6 months (mean +/- SE), respectively. To assess the ovarian influence on developmental changes in LH, data were simultaneously obtained from neonatally ovariectomized animals at similar ages. The estimation of circulating LH was made with RIA as well as biological assay. During the prepubertal period (10-20 months of age), basal LH was very low, and there was no circadian fluctuation of LH in gonadally intact monkeys. During the early pubertal stage (20-30 months of age), before menarche, basal LH levels started to increase, and a circadian LH rhythm (nocturnal increases) appeared. At the midpubertal stage (30-50 months of age), a period between menarche and first ovulation, basal LH levels further increased, and the circadian LH rhythm was maximal. At the late pubertal stage (50-60 months of age), a period after the first ovulation during which the animals were not able to reproduce fully as adults, basal LH declined, and the circadian rhythm diminished. Similar but more exaggerated developmental changes in basal LH and the circadian fluctuation of LH were observed in females ovariectomized neonatally. Basal LH levels at 10-20 months were as low as those in intact animals with no circadian rhythm present. During the early pubertal period, a circadian fluctuation appeared at the time when a slight increase in the basal LH level occurred. Furthermore, the amplitude of circadian fluctuation (the difference between morning and evening LH values) increased linearly with the increase in basal LH during the midpubertal stage. These LH parameters in ovariectomized animals reached their peaks at 40-44 months, an age before the first ovulation in intact animals. As basal LH levels declined during the late pubertal stage to postpubertal stage, circadian fluctuation disappeared. The results suggest that the increase in LH output and concomitant circadian fluctuations occur in close association with the pubertal process, and this change in LH release is not dependent on the presence of the ovary. Therefore, we suggest that alteration of the LHRH release pattern during maturation, as reflected by LH release, rather than resetting of the gonadostat, is the key factor involved in the mechanism of the onset of puberty.

The C-terminal domain of the Bloom syndrome DNA helicase is essential for genomic stability.

BACKGROUND: Bloom syndrome is a rare cancer-prone disorder in which the cells of affected persons have a high frequency of somatic mutation and genomic instability. Bloom syndrome cells have a distinctive high frequency of sister chromatid exchange and quadriradial formation. BLM, the protein altered in BS, is a member of the RecQ DNA helicase family, whose members share an average of 40% identity in the helicase domain and have divergent N-terminal and C-terminal flanking regions of variable lengths. The BLM DNA helicase has been shown to localize to the ND10 (nuclear domain 10) or PML (promyelocytic leukemia) nuclear bodies, where it associates with TOPIIIalpha, and to the nucleolus. RESULTS: This report demonstrates that the N-terminal domain of BLM is responsible for localization of the protein to the nuclear bodies, while the C-terminal domain directs the protein to the nucleolus. Deletions of the N-terminal domain of BLM have little effect on sister chromatid exchange frequency and chromosome stability as compared to helicase and C-terminal mutations which can increase SCE frequency and chromosome abnormalities. CONCLUSION: The helicase activity and the C-terminal domain of BLM are critical for maintaining genomic stability as measured by the sister chromatid exchange assay. The localization of BLM into the nucleolus by the C-terminal domain appears to be more important to genomic stability than localization in the nuclear bodies.

Barium enemas in the frail elderly.

PURPOSE: The objective of this investigation was to determine the frequency of and predictors for inadequate barium enemas in the frail elderly. PATIENTS AND METHODS: The medical and radiologic records of 171 elderly institutionalized patients (mean age = 85.3 years), who underwent barium enema examinations, were retrospectively reviewed. The study outcome of primary interest was the radiologist's report of the adequacy of examination as indicated in the written summary of the results of the barium enema procedure. RESULTS: Eighty-eight (51.5%) of the 171 studies were deemed inadequate, with poor bowel preparation a primary or contributing factor in 89.7% of the inadequate studies. Among a variety of demographic and clinical factors, only long-term laxative and/or cathartic use was associated with an inadequate study (odds ratio = 7.0; 95% confidence interval 2.7 to 18.0). CONCLUSION: These results demonstrate a very high frequency of inadequate barium enema examinations in the very old and suggest a need for improved methods of bowel preparation in this patient population, especially in those who are long-term users of laxatives and cathartics.

Parental genetic contribution to mode of presentation in Pompe disease.

Echocardiograms were performed on parents of five infants with Pompe disease (glycogen storage disease, type II). Three of the infants had presented with congestive cardiomyopathy and two with dynamic muscular subaortic stenosis. No heart murmurs were audible in any of the parents of the five infants. The parents of the three infants without left ventricular outflow tract obstruction had normal echocardiographic results, whereas one parent of each of the infants with left ventricular outflow obstruction had asymmetric septal hypertrophy. The association between left ventricular outflow obstruction and parental asymmetric septal hypertrophy suggests that both septal hypertrophy and glycogen storage disease were inherited by these two infants.

Echocardiographic mitral valve deformity in the mucopolysaccharidoses.

Previously reported echocardiographic abnormalities in patients with mucopolysaccaridosis and the Hunter-Hurler phenotype have stressed the similarity to calcific mitral stenosis despite the fact that mitral stenosis is a relatively uncommon manifestation of this disease. The purpose of this report is to describe the echocardiographic abnormalities in five patients with the Hunter-Hurler phenotype who had no clinical evidence of mitral stenosis. All had abnormal thickening of the mitral valve leaflets and one had echoes suggestive of calcification of the mitral annulus. All patients had normal electrocardiograms and roentgenographic cardiothoracic ratios, and two patients had no cardiac murmur. The high frequency of valvular deformity in this disease and the sensitivity of echocardiography in detecting these deformities suggest that echocardiography should be performed in the evaluation of patients with mucopolysaccharidosis. When echocardiographic evidence of valvular deformity is obtained, consideration should be given to bacterial endocarditis prophylaxis.