Detection of the Philadelphia chromosome in acute lymphoblastic leukemia by pulsed-field gel electrophoresis

The Philadelphia (Ph1) chromosome is an acquired abnormality in the malignant cells of 10% to 25% of patients with acute lymphoblastic leukemia (ALL). Unlike chronic myelogenous leukemia (CML), where the molecular detection of the Ph1 chromosome is relatively straightforward using conventional Southern hybridization analysis, the detection of the Ph1 chromosome in ALL is complicated by the existence of several molecular subtypes, and the fact that translocation breakpoints are dispersed over a large genomic area. To circumvent these difficulties, we investigated pulsed-field gel electrophoresis (PFGE) to determine if this method could be used directly on clinical samples to detect the Ph1 chromosome in ALL. We report that, in a study of seven patients with Ph1-positive ALL, we could easily detect the Ph1 using only a single PFGE analysis, regardless of the Ph1 subtype, and we could confirm that the translocations occur either within or very near the BCR gene in all seven. We conclude that PFGE is a useful technique for the detection of the Ph1 in ALL, which ultimately may find wide applicability in the detection of other chromosomal abnormalities in other malignancies.     

A review of friedreich ataxia clinical trial results

There are now 21 agents or classes of therapeutic agents in the Friedreich ataxia research pipeline (http://www.curefa.org/pipeline.html) that have been developed in the 15 years since the discovery of the frataxin gene, with the ongoing characterization of its mutations and the resulting molecular pathology. Twenty-four studies are currently posted on ClinicalTrials.gov. Twenty-seven works discussing the results of clinical trials in Friedreich ataxia have been published. In 2010, 42 public (National Institutes of Health) and private (Friedreich Ataxia Research Alliance, Muscular Dystrophy Association, and National Ataxia Foundation) grants were funded for translational and clinical research in Friedreich ataxia. Millions of dollars from public, private, and industry-based initiatives have been dedicated to research in Friedreich ataxia therapeutics. Despite this vigorous international effort, there is as yet no proven disease-modifying therapy for Friedreich ataxia.     

Neural activation of swallowing and swallowing‐related tasks in healthy young adults: An attempt to separate the components of deglutition

Understanding the underlying neural pathways that govern the highly complex neuromuscular action of swallowing is considered crucial in the process of correctly identifying and treating swallowing disorders. The aim of the present investigation was to identify the neural activations of the different components of deglutition in healthy young adults using functional magnetic resonance imaging (fMRI). Ten right‐handed young healthy individuals were scanned in a 3‐Tesla Siemens Allegra MRI scanner. Participants were visually cued for both a “Swallow” task and for component/control tasks (“Prepare to swallow”, “Tap your tongue”, and “Clear your throat”) in a randomized order (event‐related design). Behavioral interleaved gradient (BIG) methodology was used to address movement‐related artifacts. Areas activated during each of the three component tasks enabled a partial differentiation of the neural localization for various components of the swallow. Areas that were more activated during throat clearing than other components included the posterior insula and small portions of the post‐ and pre‐central gyri bilaterally. Tongue tapping showed higher activation in portions of the primary sensorimotor and premotor cortices and the parietal lobules. Planning did not show any areas that were more activated than in the other component tasks. When swallowing was compared with all other tasks, there was significantly more activation in the cerebellum, thalamus, cingulate gyrus, and all areas of the primary sensorimotor cortex bilaterally. Hum Brain Mapp 2009. © 2009 Wiley‐Liss, Inc.     

In organello formaldehyde crosslinking of proteins to mtDNA: identification of bifunctional proteins

The segregating unit of mtDNA is a protein-DNA complex called the nucleoid. In an effort to understand how nucleoid proteins contribute to mtDNA organization and inheritance, we have developed an in organello formaldehyde crosslinking procedure to identify proteins associated with mtDNA. Using highly purified mitochondria, we observed a time-dependent crosslinking of protein to mtDNA as determined by sedimentation through isopycnic cesium chloride gradients. We detected approximately 20 proteins crosslinked to mtDNA and identified 11, mostly by mass spectrometry. Among them is Abf2p, an abundant, high-mobility group protein that is known to function in nucleoid morphology, and in mtDNA transactions. In addition to several other proteins with known DNA binding properties or that function in mtDNA maintenance, we identified other mtDNA-associated proteins that were not anticipated, such as the molecular chaperone Hsp60p and a Krebs cycle protein, Kgd2p. Genetic experiments indicate that hsp60-ts mutants have a petite-inducing phenotype at the permissive temperature and that a kgd2Delta mutation increases the petite-inducing phenotype of an abf2Delta mutation. Crosslinking and DNA gel shift experiments show that Hsp60p binds to single-stranded DNA with high specificity for the template strand of a putative origin of mtDNA replication. These data identify bifunctional proteins that participate in the stability of rho(+) mtDNA.     

Outcome following cardiopulmonary resuscitation in the neonate requiring ventilatory assistance

BACKGROUND: there is limited data regarding the clinical characteristics and outcome of the neonate requiring ventilatory assistance who develops persistent bradycardia (PB) requiring cardiopulmonary resuscitation (CPR). OBJECTIVES: (1) to determine the percentage of newborn infants requiring respiratory assistance who develop PB and require CPR as part of resuscitation; (2) the associated clinical events; and (3) the short term outcome. METHODS: the medical charts of infants admitted to a neonatal intensive care unit who developed PB, defined as a heart rate <80 beats/min requiring CPR, were retrospectively reviewed. RESULTS: for 3 years, 39 (2.6%) of 1485 infants exhibited 62 episodes of PB requiring CPR; this represents 5.6% of 695 intubated infants. Fourteen (36%) infants rapidly responded to chest compressions only with restoration of heart rate within 2 min; termed brief CPR. None died in-hospital. Twenty-five (64%) infants required prolonged chest compressions, i.e. >2 min (termed prolonged CPR); 21 also received epinephrine. The median postnatal age at onset of CPR was 20 days (range 1-148 days) and the duration of CPR was 10 min (range 3-73 min). The more common medical conditions that may have contributed to the PB included severe bronchospasm associated with chronic lung disease (CLD) (n=6), shock associated with sepsis (n=4) and necrotizing enterocolitis (NEC) (n=2), pneumothorax (n=2), inadequate or improper ventilation (n=3), other (n=8). Nineteen (76%) infants died: 13 within 24 h of the event and six from 3 to 194 days following CPR. At 18 months follow-up, four of the six infants evaluated have a moderate to severe neurodevelopmental deficit. Of the nine infants requiring brief CPR who were evaluated, five are developing normally and four have a moderate to severe neurodevelopmental deficit. CONCLUSION: CPR in the neonate who requires ventilatory assistance is not uncommon. When brief in nature, mortality is low and short-term outcome is likely to be determined by the underlying medical condition. When CPR is prolonged, mortality is high and short-term outcome is poor.     

Negative regulation of angiotensinogen gene expression by glucocorticoids in fetal sheep liver

The effect of glucocorticoids in regulating liver angiotensinogen gene expression was studied in chronically instrumented fetal sheep during the last trimester of gestation and was compared with the expression of other hepatic genes (prothrombin, factor IX, and albumin). Four sets of twins were studied at 118 d of gestation, and three sets were studied at 138 d of gestation (term, 145 d). One of each set of twins was infused intraperitoneally with cortisol (5 mumol.mL-1.h-1) for 48 h, whereas the other twin received the same volume (1 mL/h) of normal saline. Plasma cortisol concentration increased from 0.32 +/- 0.12 and 2.7 +/- 0.12 nmol/100 mL to 44.2 +/- 20.0 and 37.7 +/- 8.2 nmol/100 mL in 118- and 138-d fetuses, respectively, during the cortisol infusion; no changes were observed in fetuses infused with saline alone. At the end of the infusion period, the animals were anesthetized, the fetal liver was removed, and total cellular RNA was isolated and probed for angiotensinogen, prothrombin, factor IX, and albumin. The results demonstrated that cortisol infusion decreased angiotensinogen mRNA by 61% in 138-d fetuses and albumin mRNA expression by 2.4-fold in 118-d fetuses and by 3.4-fold in 138-d fetuses. On the other hand, cortisol had no effect on fetal factor IX gene expression but increased prothrombin mRNA levels by 65% in 118-d fetuses and 62% in 138-d fetuses. Taken together, our results suggest that, during fetal life, angiotensinogen gene expression is negatively regulated by glucocorticoids. This effect is not universal because cortisol increases fetal prothrombin gene expression.     

Movement disorder of premature infants with severe bronchopulmonary dysplasia: a new syndrome

A previously unrecognized, striking movement disorder has been observed in 10 premature infants with severe bronchopulmonary dysplasia. Chronic hypoxemia, hypercarbia, bronchospasm, and inadequate nutrition were present in all. The movement disorder developed from approximately the third postnatal month. The dominant movements involve the limbs, neck, trunk, and oral-buccal-lingual structures. The limb movements were most prominent distally and consisted of rapid, random, jerky movements (similar to chorea) and "restless" movements (similar to akathisia). Similar movements of the neck and face were observed; tongue movements had a "darting" quality. The oral-buccal-lingual movements were similar to the dyskinesia of older patients. Movements were exacerbated during episodes of respiratory failure and attenuated during sleep. All infants exhibited feeding disorders, largely due to tongue movements. In 3 infants treated with clonazepam, there was striking improvement in motor function, including feeding. The natural history was partial or complete resolution or a static course. Thus, of the 7 surviving infants, the movements were absent (without therapy) at 15, 18, and 30 months of age. In the remaining 4 infants (3 of whom receive clonazepam), the movements, though attenuated, persisted at 6, 12, 15 and 21 months of age, respectively. Neuropathologically, 1 infant showed neuronal loss with astrocytosis in caudate, putamen, globus pallidus, and thalamus. These data defined a previously unrecognized extrapyramidal movement disorder of infants with severe bronchopulmonary dysplasia; pathogenesis may be related to chronic hypoxemia.