Neural injury and recovery near cortical contusions: a clinical magnetic resonance spectroscopy study

Object

Proton magnetic resonance (MR) spectroscopy can detect neural metabolic alterations noninvasively after traumatic brain injury (TBI) even in areas that appear normal. Unlike metabolic depression in diffuse TBI, focal metabolic alterations near cortical contusions in humans have not been previously investigated in a longitudinal study. The object of this study was to identify these alterations and examine their course.

Methods

At 1 week and 1 month after mild to moderate TBI involving cortical contusion, 30 patients underwent 1H MR spectroscopy examination that focused bilaterally on normal-appearing frontal and temporal white matter. Levels of N-acetylaspartate (NAA), choline (Cho) compounds, and creatine (Cr) were measured to obtain two metabolite ratios, NAA/Cr and Cho/Cr. The ratios were compared with those of 11 healthy individuals.

At 1 week after TBI, the NAA/Cr ratio was significantly lower near cortical contusions than it was in white matter remote from the injury or in controls, while the Cho/Cr ratios did not differ significantly. At 1 month, the decreased NAA/Cr ratios near contusions had increased significantly from 1 week, as had the Cho/Cr ratio.

Conclusions

Metabolic depression reflecting neural injury was apparent in subjacent normal-appearing white matter at 1 week after cortical contusion; this had normalized substantially at 1 month.

Mitochondrial-related gene expression changes are sensitive to agonal-pH state: implications for brain disorders

Mitochondrial defects in gene expression have been implicated in the pathophysiology of bipolar disorder and schizophrenia. We have now contrasted control brains with low pH versus high pH and showed that 28% of genes in mitochondrial-related pathways meet criteria for differential expression. A majority of genes in the mitochondrial, chaperone and proteasome pathways of nuclear DNA-encoded gene expression were decreased with decreased brain pH, whereas a majority of genes in the apoptotic and reactive oxygen stress pathways showed an increased gene expression with a decreased brain pH. There was a significant increase in mitochondrial DNA copy number and mitochondrial DNA gene expression with increased agonal duration. To minimize effects of agonal-pH state on mood disorder comparisons, two classic approaches were used, removing all subjects with low pH and agonal factors from analysis, or grouping low and high pH as a separate variable. Three groups of potential candidate genes emerged that may be mood disorder related: (a) genes that showed no sensitivity to pH but were differentially expressed in bipolar disorder or major depressive disorder; (b) genes that were altered by agonal-pH in one direction but altered in mood disorder in the opposite direction to agonal-pH and (c) genes with agonal-pH sensitivity that displayed the same direction of changes in mood disorder. Genes from these categories such as NR4A1 and HSPA2 were confirmed with Q-PCR. The interpretation of postmortem brain studies involving broad mitochondrial gene expression and related pathway alterations must be monitored against the strong effect of agonal-pH state. Genes with the least sensitivity to agonal-pH could present a starting point for candidate gene search in neuropsychiatric disorders.

Enhanced therapeutic efficacy of G207 for the treatment of glioma through Musashi1 promoter retargeting of gamma34.5-mediated virulence

G207 is a conditionally replicating derivative of herpes simplex virus type1 (HSV-1) engineered with deletions of both ICP34.5 loci and a lacZ insertion disabling the ICP6 gene. G207 exhibits an efficient oncolytic activity in vitro and in vivo, yet minimal toxicity in normal tissue, and is now in clinical trial for malignant glioma. According to the results of clinical trials, however, although G207 was proved to be safe, the efficacy was not so impressive. Deletion of the ICP34.5 gene coding for virulence made G207 extremely safe, but it markedly reduced the cytotoxicity mediated by HSV-1. To enhance the therapeutic efficacy of G207 without diminishing its safety, we used a defective vector containing Musashi1 promoter/ICP34.5, with G207 as helper virus. P/musashi1 was functional selectively in human glioma cell lines (U87MG, U251, T98G) in this study and dvM345 showed a much higher therapeutic efficacy both in culture and in the in vivo glioma model, than G207 alone, without diminishing its favorable toxicity profile. These results suggest that transcriptional regulation of ICP34.5 by P/musashi1 can be used to target HSV-1 virulence toward gliomas while maintaining the desirable neuroattenuated phenotype.

[Stent-assisted coiling of an acutely ruptured large aneurysm of the internal carotid artery: case report]

A 48-year-old female was referred to our hospital for the management of a ruptured 22-mm-diameter internal carotid aneurysm, located immediately distal to the ophthalmic artery. The right internal carotid artery was completely involved in the aneurysm. Because the right carotid siphon was relatively nontortuous stent-assisted coiling of the aneurysm was attempted 4 days after subarachnoid hemorrhage. A new coil-type coronary stent, a DRIVER stent, was deployed after microcatheter insertion into the aneurysm dome under systemic heparinization, followed by dome packing using Guglielmi detachable coils. Systemic heparinization was continued for 18 hours postoperatively, and aspirin (100 mg/day) was administered orally immediately after the embolization. However, 4 hours after heparin administration cessation, left hemiparesis became apparent. Immediate magnetic resonance angiography revealed a right internal carotid artery occlusion. Diffusion-weighted images demonstrated ischemic spots in the watershed zones of the right cerebral hemisphere. Following an immediate thrombolysis of the right internal carotid artery, systemic heparinization was continued for 5 days, and aspirin and ticlopidine were administrated orally. The patient was discharged on day 37, following the recovery from left hemiparesis within ten days. A DRIVER stent is a low profile coil-type coronary stent, which can be used for the stent-assisted coiling of large internal carotid aneurysms, located distal to the carotid siphon. It seems necessary to continue systemic heparinization for more than 2 days and to administer increased dose or two types of antiplatelet after the stent-assisted coiling of large cerebral aneurysms.

Coil Embolization for Ruptured Cerebral Aneurysms of 2x3 mm Diameter

SUMMARY

Small ruptured cerebral aneurysms, such as those of 2x3 mm diameter, are considered to be difficult to embolize by detachable coils because of the risk of procedural perforation of the aneurysms. We have treated these small aneurysms and report the techniques and pitfalls of these embolizations. Twenty-four patients with ruptured cerebral aneurysms of 2x3 mm diameter were intended for treatment by coil embolization. Before coil embolization, three-dimensional digital subtraction angiography was performed, and the simulation of the volume embolization ratio (VER) was performed in all patients, except for the first basilar artery aneurysm patient. The tip of the microcatheter was steam-shaped several times and was placed on the neck of the aneurysm. A balloon neck remodeling technique was used for two aneurysms. GDC 10 softs and soft SRs were used for the first ten aneurysms, and Ultrasofts were used for the last eleven aneurysms. Out of twentyfour aneurysm embolizations, we aborted the procedure in three cases, because of a failure in catheterization; we performed clipping surgery for these cases. For the first case of a basilar tip aneurysm, the aneurysm was perforated, due to the use of too long a coil and the insertion of the tip of the microcatheter into the aneurysmal dome. Minor infarction occurred in one patient. The mean VER was 33.9%, and two aneurysms recanalized, and out of these one needed a second embolization. Six months postoperatively, 81% of patients had made in a good recovery or had a moderate disability.We recommend the following techniques to embolize aneurysms of 2x3 mm diameter: the tip of the microcatheter should be stabilized on the aneurysmal neck by steam shaping of the microcatheter, GDC 10 soft and Ultrasoft should be selected for use, and the simulation of the VER should be performed before embolization to select coils of a suitable length.

Altered cortical glutamatergic and GABAergic signal transmission with glial involvement in depression

Abnormalities in L-glutamic acid (glutamate) and GABA signal transmission have been postulated to play a role in depression, but little is known about the underlying molecular determinants and neural mechanisms. Microarray analysis of specific areas of cerebral cortex from individuals who had suffered from major depressive disorder demonstrated significant down-regulation of SLC1A2 and SLC1A3, two key members of the glutamate/neutral amino acid transporter protein family, SLC1. Similarly, expression of L-glutamate-ammonia ligase, the enzyme that converts glutamate to nontoxic glutamine was significantly decreased. Together, these changes could elevate levels of extracellular glutamate considerably, which is potentially neurotoxic and can affect the efficiency of glutamate signaling. The astroglial distribution of the two glutamate transporters and L-glutamate-ammonia ligase strongly links glia to the pathophysiology of depression and challenges the conventional notion that depression is solely a neuronal disorder. The same cortical areas displayed concomitant up-regulation of several glutamate and GABA(A) receptor subunits, of which GABA(A)alpha1 and GABA(A)beta3 showed selectivity for individuals who had died by suicide, indicating their potential utility as biomarkers of suicidality. These findings point to previously undiscovered molecular underpinnings of the pathophysiology of major depression and offer potentially new pharmacological targets for treating depression.

Endovascular surgery as the first-choice treatment for ruptured cerebral aneurysms: how far has it come?

SUMMARY

One hundred and seventy patients with ruptured cerebral aneurysms were treated by coil embolization from September 1997 to December 2002. After January 2000, coil embolization was selected as the first-choice treatment for ruptured aneurysms. During this period, the authors investigated the number of aborted cases, the number of complications, and how many patients could be treated by coil embolization according to the locations of ruptured cerebral aneurysms. One hundred and ninety-five sessions were performed on 170 patients, and 13 sessions (6.7%) were aborted mainly because of the difficulty of the approach and the wide necks of the aneurysms. In four patients, although procedural perforation and haemorrhage occurred, the outcome was good or excellent. Eight poorgrade patients experienced haemorrhage after coil embolization and seven patients died. The volume embolization ratios of small and large aneurysms were 27% and 21%, and the recanalization of small and large aneurysms occurred in 9% and 38% of patients, respectively. From January 2000 to December 2002, 119 (66%) of 180 ruptured cerebral aneurysms were treated by coil embolization. According to the location of aneurysms, 89% vertebrobasilar, 87% anterior cerebral, 65% internal carotid and 24% middle cerebral artery aneurysms could be treated by coil embolization. Because the tight packing of large aneurysms was difficult, the recanalization rate of large aneurysms was high. However, the results of small aneurysms were satisfactory. Almost 90% of vertebrobasilar and anterior cerebral artery aneurysms could be treated by coil embolization.

Dysregulation of the fibroblast growth factor system in major depression

In this report we describe findings that imply dysregulation of several fibroblast growth factor (FGF) system transcripts in frontal cortical regions of brains from human subjects with major depressive disorder (MDD). This altered gene expression was discovered by microarray analysis of frontal cortical tissue from MDD, bipolar, and nonpsychiatric control subjects and was verified by quantitative real-time PCR analysis and, importantly, in a separate cohort of MDD subjects. Furthermore, we show, through a separate analysis of specific serotonin reuptake inhibitor (SSRI)-treated and non-SSRI-treated MDD subjects that the observed changes in expression of FGF transcripts are not secondary to drug treatment. Rather, changes in specific FGF transcripts are attenuated by SSRIs and may thus be partially responsible for the mechanism of action of these drugs. We also make available the gene-expression profile of all of the other growth factors and growth factor receptors detected in these postmortem samples.

Systemic lupus erythematosus-like autoimmune abnormalities induced by bacterial infection

Recent evidence has revealed that bacterial DNA can promote several of the autoimmune abnormalities observed in systemic lupus erythematosus (SLE), and a possible pathogenic role in the induction of SLE has been highlighted. We have recently encountered patients in whom bacterial infection (septicemia) triggered the production of several autoantibodies. This seems to be interesting with respect to the consideration of the relationship between SLE and bacterial infection.

Novel truncated isoform of SK3 potassium channel is a potent dominant-negative regulator of SK currents: implications in schizophrenia

The small-conductance calcium-activated K(+) channel SK3 (SKCa3/KCNN3) regulates electrical excitability and neurotransmitter release in monoaminergic neurons, and has been implicated in schizophrenia, ataxia and anorexia nervosa. We have identified a novel SK3 transcript, SK3-1B that utilizes an alternative first exon (exon 1B), but is otherwise identical to SK3. SK3-1B, mRNA is widely distributed in human tissues and is present at 20-60% of SK3 in the brain. The SK3-1B protein lacks the N-terminus and first transmembrane segment, and begins eight residues upstream of the second transmembrane segment. When expressed alone, SK3-1B did not produce functional channels, but selectively suppressed endogenous SK3 currents in the pheochromocytoma cell line, PC12, in a dominant-negative fashion. This dominant inhibitory effect extended to other members of the SK subfamily, but not to voltage-gated K(+) channels, and appears to be due to intracellular trapping of endogenous SK channels. The effect of SK3-1B expression is very similar to that produced by expression of the rare SK3 truncation allele, SK3-Delta, found in a patient with schizophrenia. Regulation of SK3 and SK3-1B levels may provide a potent mechanism to titrate neuronal firing rates and neurotransmitter release in monoaminergic neurons, and alterations in the relative abundance of these proteins could contribute to abnormal neuronal excitability, and to the pathogenesis of schizophrenia.

Jarcho-levin syndrome associated with a complex congenital heart anomaly

Jarcho-Levin syndrome is characterized by "crab-like" rib cage deformity and multiple vertebral anomalies that cause respiratory failure. Reports of complex congenital heart defects with this syndrome are rare. We describe a female infant with this syndrome and a complex congenital heart defect and review the literature. Congenital heart defects are occasionally complicated by Jarcho-Levin syndrome. Heart defects involving heterotaxic morphology should be included as one of the important clinical features of this syndrome.

Chronological changes of perihematomal edema of human intracerebral hematoma

Recent investigations have indicated the importance of secondary brain damage in the pathophysiology of intracerebral hemorrhage (ICH), which includes ischemic brain damage and edema formation around a hematoma. The purpose of the current study is to investigate chronological changes of perihematomal edema in patients with human ICH and also the correlation between volume of perihematomal edema and neurological status. Fourteen patients with medium-sized putaminal hemorrhage (29.4 +/- 13.2 ml) without hematoma enlargement were included in this study. To investigate chronological changes of perihematomal edema, we performed CT scans prospectively on the day of hemorrhage and repeated them on days 1, 3, 7, 14, and 28. We evaluated the patients neurologically using the NIH stroke scale on the day a CT scan was performed. The volume of perihematomal edema in human ICH increased rapidly three days after hemorrhage and the score on the NIH stroke scale showed a deterioration. The volume of perihematomal edema then increased slowly until day 14 after hemorrhage, and decreased thereafter. Despite progression of perihematomal edema, the score on the NIH stroke scale improved gradually after day 3.

Adenosine A1 receptor activation selectively impairs the acquisition of contextual fear conditioning in rats

Three experiments were conducted to examine the importance of adenosine A1 receptors for the acquisition and expression of hippocampal-dependent and hippocampal-independent forms of conditioned fear. In Experiment 1, the selective adenosine A1 receptor agonist, N6-cyclopentyladenosine (CPA), or saline was administered intraperitoneally to male rats 30 min prior to Pavlovian fear conditioning, which consisted of 7 tone-shock pairings. Adenosine A1 receptor activation dose-dependently and selectively disrupted the acquisition of contextual fear conditioning while sparing tone-shock associations. Experiments 2 and 3 demonstrated that CPA's selective disruption of contextual learning could not be attributed to context being weaker than tone conditioning or to state-dependent learning. Adenosine A1 receptor activation also impaired the expression of both context- and tone-elicited fear. These results suggest that endogenous adenosine modulates the acquisition and expression of emotional (fear) memories by acting on A1 receptors in brain regions underlying fear conditioning.

Oncologic implications of laparoscopic and open surgery

Although instrumental manipulation and mechanical tumor cell spillage seem to play the major role in port-site metastases from laparoscopic cancer surgery, minimally invasive procedures are used more and more in the resection of malignancies. However, port-site metastases also have been reported after resection of colon cancer in International Union Against Cancer (UICC) stage I [2, 14]. Therefore, changes in the peritoneal environment during laparoscopy also might influence intra- and extraperitoneal tumor growth during laparoscopy and pneumoperitoneum. Different results of experimental studies presented at the Third International Conference for Laparoscopic Surgery are analyzed and discussed.

Genomic organization and promoter analysis of human KCNN3 gene

KCNN3 is a member of the gene family, KCNN1-4, encoding the small and intermediate conductance calcium-activated potassium channels. Long CAG-repeat alleles of this gene have been found to be over-represented in patients with schizophrenia in a number of population-based association studies, and this gene maps to human chromosome 1q21, a region recently implicated in schizophrenia by linkage. To set the stage for a further functional evaluation of KCNN3, we defined the nature of the genomic locus in the size, structure, and sequence of its introns and exons and the function of potential upstream regulatory regions. We isolated P1-derived artificial chromosome (PAC) clones from a genomic library and identified an overlapping available bacterial artificial chromosome (BAC) clone. Cosmids subcloned from the PAC and BAC clones were then sequenced and merged with the sequence in the public database. The KCNN3 gene spans over 163.1 kb and is composed of eight exons and seven introns. All of the exon-intron junctions conform closely to consensus splice sites. The proximal 2.5 kb of the 5'-flanking sequence was obtained and analyzed for potential transcription factor binding sites. In the proximal 2.5 kb upstream region, potential sites for the Ikaros factor (IK2), homeodomain factor Nkx-2.5/Csx (NKX25), nuclear factor of activated T-cells (NFAT), upstream stimulating factor (USF), c-AMP responsive element binding protein (CREB), POU factor Brn2 (BRN-2), myeloid zinc finger protein (MZF1), vitellogenin binding protein (VBP), HNF3 forkhead homologue 2 (HFH2), and transcription initiation were identified, as well as several potential AP-1 and AP-4 sites. Finally, a 2261-bp fragment of this upstream region was cloned into a promoterless pGL3-luciferase vector, where it produced orientation-dependent expression of the reporter gene in transiently transfected PC12 cells, cells which natively express functional KCNN3 channels, suggesting that this cloned fragment includes competent promoter elements of this gene.

Delayed-onset ataxia in mice lacking alpha -tocopherol transfer protein: model for neuronal degeneration caused by chronic oxidative stress

alpha-Tocopherol transfer protein (alpha-TTP) maintains the concentration of serum alpha-tocopherol (vitamin E), one of the most potent fat-soluble antioxidants, by facilitating alpha-tocopherol export from the liver. Mutations of the alpha-TTP gene are linked to ataxia with isolated vitamin E deficiency (AVED). We produced a model mouse of AVED by deleting the alpha-TTP gene, which showed ataxia and retinal degeneration after 1 year of age. Because the brain alpha-TTP functions in maintaining alpha-tocopherol levels in the brain, alpha-tocopherol was completely depleted in the alpha-TTP(-/-) mouse brain, and the neurological phenotype of alpha-TTP(-/-) mice is much more severe than that of wild-type mice when maintained on an alpha-tocopherol-deficient diet. Lipid peroxidation in alpha-TTP(-/-) mice brains showed a significant increase, especially in degenerating neurons. alpha-Tocopherol supplementation suppressed lipid peroxidation and almost completely prevented the development of neurological symptoms. This therapy almost completely corrects the abnormalities in a mouse model of human neurodegenerative disease. Moreover, alpha-TTP(-/-) mice may prove to be excellent animal models of delayed onset, slowly progressive neuronal degeneration caused by chronic oxidative stress.

Nationwide survey shows that methicillin-resistant Staphylococcus aureus strains heterogeneously and intermediately resistant to vancomycin are not disseminated throughout Japanese hospitals

A total of 6,625 methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates obtained from 278 hospitals throughout Japan were obtained between November and December 1997 and were examined for their sensitivities to vancomycin using Mueller Hinton (MH), brain heart infusion (BHI), agar plates, or the broth microdilution method. A concentrated inoculum of an MRSA strain or the use of highly enriched medium, such as BHI medium, allows an individual cell to grow on agar plates containing a vancomycin concentration greater than the MIC for the parent strain. However, cells of the colonies which grew on BHI agar plates containing the higher vancomycin concentrations did not acquire a level of vancomycin resistance greater than that of the parent strain and were not subpopulations of heterogeneously vancomycin-resistant MRSA. There was no significance in the fact that these colonies grew on the higher concentration of vancomycin: none showed stable resistance to vancomycin at a concentration above the MIC for the parent strain, and no cell from these colonies showed a relationship between the MIC and the ability of these colonies to grow on higher concentrations of vancomycin. The vancomycin MIC was not above 2 microg/ml for any of the cells originating from these colonies. No Mu3-type heterogeneously resistant MRSA strains, which constitutively produce subpopulations from MRSA clinical isolates with intermediate vancomycin resistance at a high frequency, were detected. There was a unipolar distribution of the MICs ranging from 0.25 to 2 microg of vancomycin/ml among the 6,625 MRSA clinical isolates, indicating that there was no Mu50-type intermediately vancomycin-resistant MRSA (MIC, 8 microg/ml by National Committee for Clinical Laboratory Standards criteria) among the clinical isolates, and there was no evidence of dissemination of Mu3-type MRSA heteroresistant to vancomycin.