Emergency Transcatheter Aortic Valve Implantation in a Surgical Aortic Bioprosthetic Valve for Acute Decompensated Heart Failure Caused by Sudden Progression of Structural Valve Deterioration

Bioprosthetic aortic valves have limited durability. We herein report sudden progression of structural valve deterioration (SVD) and a successful case of emergency transcatheter aortic valve (TAV) implantation for acute decompensated heart failure (ADHF) caused by SVD. A 79-year-old man who had undergone a Bentall operation 11 years prior was diagnosed with ADHF due to suddenly progressive SVD. Emergency TAV implantation in the surgical bioprosthetic valve was selected based on the surgical risk. Ours and previous case reports suggest that SVD can progress suddenly, even after months of stability, and that emergency TAV implantation is effective.

Significance of H3K27M mutation with specific histomorphological features and associated molecular alterations in pediatric high-grade glial tumors

PURPOSE

Pediatric high-grade gliomas (pHGGs) constitute almost 15% of all childhood brain tumors. Recurrent mutations such as H3K27M mutation in H3F3A and HIST1H3B genes encoding histone H3 and its variants were identified in approximately 30% of pediatric glioblastomas. This study aimed to ascertain the morphological and molecular characteristics of pHGGs with H3K27M mutation.

METHODS

In total, 61 cases of pHGGs (anaplastic astrocytoma, 12; glioblastomas, 49) from four university hospitals were studied. The histomorphological features were examined and immunohistochemistry was performed to evaluate the mutation status of H3K27M, ATRX, IDH1, BRAF V600E, and p53 genes.

RESULTS

The study comprised 25 females and 36 males (age range, 1-18 years) with a clinical follow-up of up to 108 months. From the total, 31 patients were positive for H3K27M mutation located in the midline, mostly in the pons and thalamus. H3K27M mutation was commonly associated with ATRX loss (32.3%) and p53 (74.2%) immunoreactivity with a co-expression rate of 25.8%. While IDH1 mutation was not detected in pHGGs with H3K27M mutation, BRAFV600E mutation was rarely observed. Among the various histomorphological features, increased number of mitosis, increased Ki-67 proliferation index, and palisading and geographical necrosis along with small cell patterns were significantly associated with the H3K27M wild-type tumors. Focal infarct-like necrosis and pilomyxoid morphology was significantly associated with these tumors.

CONCLUSION

H3K27M mutation occurs exclusively in pHGGs arising from the midline and presents with varied histomorphological features ranging from low-grade pilomyxoid astrocytoma to highly pleomorphic glioblastoma along with ATRX loss and p53 mutations.

Antidepressant-like effect of hyperbaric oxygen treatment in forced-swimming test in rats

The present study was undertaken to assess the antidepressant-like activity of hyperbaric oxygen (HBO) treatment and also to investigate whether in the forced-swimming test HBO treatment interacts with the antidepressant effects of fluoxetine, a selective serotonin reuptake inhibitor, and imipramine, which is mainly a noradrenaline reuptake inhibitor. HBO treatment (at 2.4 atmospheres absolute [ATA] for 60 min) significantly reduced the immobility time in this test; in other words, it displayed antidepressant-like activity. The coadministration of HBO with fluoxetine (5 mg/kg) or imipramine (5 mg/kg) at their ineffective doses produced greater inhibition of immobility time compared with HBO alone. In conclusion, HBO treatment might be an alternative approach to antidepressant therapy, alone or in combination with antidepressant drugs.

L-NAME prevents anxiety-like and depression-like behaviour in rats exposed to restraint stress

Stressful life events contribute to the development of many neuropsychiatric disorders including depression and anxiety. Animal studies based on the relationship of stress and depression or anxiety are scarce and controversial. Moreover, neither the neurobiological basis of anxiety and depression nor the mechanisms responsible for neurochemical regulation by stressful stimuli are well understood. This study was designed to investigate the possible contribution of both acute (2 h) and chronic (2 h X 15 d) restraint stress in the generation of anxiety and depression, and also to find out whether nitric oxide (NO) has a modulatory role in these behavioral reactions. Elevated plus-maze and forced swimming test (FST) were chosen for assessment of anxiety and depression, respectively, and N(G)-nitro L-arginine methyl ester (L-NAME, 10 mg/kg), a NO synthase (NOS) inhibitor, and L-arginine (50 mg/kg), a NO precursor, were used to evaluate the role of nitrergic system in restraint exposed rats. The results showed that acute and chronic stress caused depression-like and anxiety-like behaviors in rats and the acute inhibition of NOS by L-NAME prevented these acute and chronic stress-induced anxiogenesis and depression. These data lead to the conclusion that stress and NO seem to be involved in the generation of anxiety and depression.

Protective effects of dextromethorphan and tizanidine on ouabain-induced arrhythmias

The effects of the opioid agonist dextromethorphan and the alpha 2-adrenoceptor agonist tizanidine on ouabain-induced cardiac arrhythmias were investigated in rats. Ouabain (10 mg/kg i.v.) elicited ventricular arrhythmias in all of the control rats. Administration of dextromethorphan (25 mg/kg i.v.) and tizanidine (0.1 mg/kg i.v.) 30 min before ouabain treatment significantly reduced the incidence of arrhythmias. We suggest that dextromethorphan and tizanidine showed these effects by decreasing excitatory amino acid (EAA) activity. It can be speculated that opioids and other EAA antagonists may have antiarrhythmic actions through both their central and peripheral effects as well.

Therapeutic drug monitoring in Turkey: experiences from Istanbul

Therapeutic drug monitoring (TDM) has assumed an important place in patient management in the last few decades. In this study, serum drug levels determined in 7759 specimens sent to the Department of Pharmacology and Clinical Pharmacology in 1994 and 1998 for TDM were retrospectively evaluated. Monitored drugs were carbamazepine, valproate, phenytoin, phenobarbital, digoxin, theophylline, and salicylate. The comparison of the results obtained for the relevant 2 years showed that there was a remarkable increase in the number of requests for TDM per year and in the rate of serum drug levels that were within therapeutic range. Serum antiepileptic drug level monitoring accounted for a major part of the data. Overall data suggest that the use of TDM in antiepileptic drugs is improving; conversely, digoxin and theophylline are still not being properly monitored. In this study, the results are discussed in the light of rational TDM criteria.

Neonatal intracranial hemorrhage due to rupture of arteriovenous malformation

Two cases of neonatal intracerebral hemorrhage secondary to rupture of arteriovenous malformation are reported and the pertinent literature is reviewed. Despite the limited number of cases, review of the literature and our results demonstrate that the outcome of surgical removal of an arteriovenous malformation in the neonatal period is not as poor as was previously believed.

Intermittent diplopia in chordoma

The symptoms and findings of three patients with clivus chordomas who had episodes of intermittent diplopia are presented. The causes of intermittent diplopia are reviewed, and the possible mechanisms of this symptom in chordomas are discussed.

The plated bayonet: a new instrument to facilitate surgery for intra-axial neoplasms of the spinal cord and brain stem. Technical note

A new instrument for use in surgically treating intra-axial neoplasms of the spinal cord and brain stem is described. The plated bayonet allows neoplastic tissue in the spinal cord to be separated from functioning neural elements without perforating the adjacent spinal cord. In addition, the plated bayonet facilitates exposure through the very small incision necessary to remove tumors of the brain stem without damaging cranial nerves or other vital structures.