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.

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.

Design and characterization of a highly selective peptide inhibitor of the small conductance calcium-activated K+ channel, SkCa2

Apamin-sensitive small conductance calcium-activated potassium channels (SKCa1-3) mediate the slow afterhyperpolarization in neurons, but the molecular identity of the channel has not been defined because of the lack of specific inhibitors. Here we describe the structure-based design of a selective inhibitor of SKCa2. Leiurotoxin I (Lei) and PO5, peptide toxins that share the RXCQ motif, potently blocked human SKCa2 and SKCa3 but not SKCa1, whereas maurotoxin, Pi1, Tskappa, and PO1 were ineffective. Lei blocked these channels more potently than PO5 because of the presence of Ala(1), Phe(2), and Met(7). By replacing Met(7) in the RXCQ motif of Lei with the shorter, unnatural, positively charged diaminobutanoic acid (Dab), we generated Lei-Dab(7), a selective SKCa2 inhibitor (K(d) = 3.8 nm) that interacts with residues in the external vestibule of the channel. SKCa3 was rendered sensitive to Lei-Dab(7) by replacing His(521) with the corresponding SKCa2 residue (Asn(367)). Intracerebroventricular injection of Lei-Dab(7) into mice resulted in no gross central nervous system toxicity at concentrations that specifically blocked SKCa2 homotetramers. Lei-Dab(7) will be a useful tool to investigate the functional role of SKCa2 in mammalian tissues.

[Efficacy of pilsicainide for the long-term prevention of paroxysmal atrial fibrillation: analysis based on the time of onset]

OBJECTIVES

This study evaluated the efficacy of long-term pilsicainide therapy to maintain sinus rhythm in patients with paroxysmal atrial fibrillation in terms of the time of onset.

METHODS

A total of 81 patients (57 men, 24 women, mean age 65 +/- 11 years) were given pilsicainide (150 mg/day) after cardioversion. Paroxysmal atrial fibrillation was divided into three types by the time of onset: the day type (AM 7:00-PM 5:00, n = 13), the night type (PM 5:00-AM 7:00, n = 12) and the mixed type (n = 56). Mean follow-up period was 35.4 +/- 16.1 months.

RESULTS

There was a higher incidence of hypertension in the day type (38.5%) and the mixed type (48.2%) than in the night type (8.3%) (p < 0.05). The periods for maintenance of sinus rhythm in the day type, the night type and the mixed type were 15.7 +/- 5.0, 9.9 +/- 2.7 and 5.7 +/- 1.3 months, respectively, with a significant difference between the day type and the mixed type (p < 0.01). Actuarial event free-rates at 1, 3, 6, 9 and 12 months were 76.9%, 69.2%, 61.5%, 53.8% and 53.8% respectively, in the day type, 83.3%, 66.7%, 58.3%, 33.3% and 33.3%, respectively, in the night type and 58.9%, 37.5%, 26.8%, 25.0% and 21.4%, respectively, in the mixed type. There was a significant difference in the rate at 12 months between the day type and the mixed type (p < 0.05).

CONCLUSIONS

These results suggest that pilsicainide has a high degree of efficacy for maintaining normal sinus rhythm in patients with the day type onset of paroxysmal atrial fibrillation.

Stent implantation for aortic coarctation complicating the Norwood operation in a 48-day-old baby

A female infant developed severe aortic coarctation 42 days after a Norwood operation. Balloon dilatation was ineffective due to rapid recoil of the narrowing, but stent implantation completely abolished coarctation. Although the patient died because of low systemic output with high pulmonary flow 62 days after stent implantation, an autopsy showed that the implanted stent was widely patent without any restenosis. Transcatheter stent implantation should be considered for coarctation in selected situations even in early infancy.

Malignant fibrous histiocytoma of the right spermatic cord: a case report

The patient was a 47-year-old male, who visited Hidaka Hospital with a chief complaint of swelling in the right inguinal region and the scrotum. With a diagnosis of a right spermatic cord tumor, right high orchiectomy was performed. Since an inflammatory type of malignant fibrous histiocytoma (MFH) was diagnosed from histopathological findings, chemotherapy and radiation therapy were performed as postoperative treatment. Malignant fibrous histiocytoma with the primary focus of the spermatic cords is a rare disease. To our knowledge, this is the 20th case of MFH of the spermatic cord in Japan (the 42nd in the world) and it is the second case of inflammatory type of MFH in Japan.

CO2 pneumoperitoneum does not enhance tumor growth and metastasis: study of a rat cecal wall inoculation model

INTRODUCTION

Although many studies have evaluated the effects of carbon dioxide pneumoperitoneum on port site recurrence, little is known about its outcome on tumor growth and metastasis. The effect of pneumoperitoneum with carbon dioxide on cecal tumor growth and metastasis was compared with laparotomy using a rat colon cancer cell line.

METHODS

Time Course Study: Fifty WF/BN F1 hybrid rats were inoculated with 2,000,000 WB2054M5 tumor cells into the cecal wall and explored two to ten weeks after injection. Main Study: 152 rats were randomly assigned either to 6-mmHg CO2 pneumoperitoneum (30 minutes) or 4-cm laparotomy (30 minutes) two weeks after tumor inoculation and were explored four weeks after treatment.

RESULTS

Time Course Study: Thirty-seven (95 percent) of the surviving rats developed a cecal wall tumor, and there was progressive tumor growth and metastasis over the ten-week period. At six weeks, metastasis occurred to the liver in 25 percent, to the lung in 38 percent, and to the lymph node in 63 percent, and peritoneal seeding occurred in 38 percent; this time period was chosen for the main study. Main Study: At the time of treatment (2 weeks), 124 rats were eligible for randomization. One hundred two rats survived the six-week period (50 pneumoperitoneum, 52 laparotomy) and were killed. There were no differences between the CO2 pneumoperitoneum and laparotomy groups regarding cecal tumor growth (1.043 vs. 0.894 g) and metastases to the liver (32 vs. 37 percent), lung (34 vs. 17 percent), lymph node (84 vs. 77 percent), and wound or port (20 vs. 23 percent).

CONCLUSIONS

A cecal wall inoculation model mimics the natural cascade of colon cancer growth and metastasis. CO2 pneumoperitoneum did not affect the tumor growth and metastasis to the liver and other organs when compared with laparotomy in this model.

Human mast cell progenitors in peripheral blood from atopic subjects with high IgE levels

BACKGROUND

It remains unclear whether the number of circulating mast cell progenitors is increased in patients with atopic diseases. Distinct genotypes are reported to affect mast cell/basophil activation.

OBJECTIVE

We compared the number and function of mast cell progenitors present in the peripheral blood from donors with normal IgE (IgE < 400 U/mL) and those with atopic dermatitis accompanied by high serum IgE (IgE > 5000 U/mL).

METHODS

Purified peripheral blood cells were cultured in serum-free methylcellulose containing stem cell factor (SCF), IL-6 plus IL-3. Fresh methylcellulose containing the cytokines was layered over every 2 weeks. The cultured mast cells were retrieved from the methylcellulose and were functionally analysed.

RESULTS

Mast cell colonies were distinguished at 6 weeks of culture as other colony types had been degenerated. The number of mast cell colony-forming cells varied depending on donors and was not significantly increased in peripheral blood from the hyper-IgE atopic patients. A significant inversed correlation was found between the number of mast cells per one colony and the ages of donors. The cultured mast cells derived from atopic patients and those from normal IgE donors equally expressed Fc epsilon RI and released histamine through Fc epsilon RI, although IL-4 priming in vitro markedly enhanced the function of mast cells regardless of donors.

CONCLUSIONS

These results indicate that the number of circulating mast cell progenitors may be regulated by unknown individual factors unrelated to IgE levels. Mast cell function may be regulated largely by environmental factors, such as IL-4, but not determined by their progenitors' genotypes.

Changes of phagocytic capacity in basic fibroblast growth factor-transfected iris pigment epithelial cells in rats

PURPOSE

To evaluate differences of phagocytic capacities in rat retinal pigment epithelial (RPE) cells, iris pigment epithelial (IPE) cells, and basic fibroblast growth factor (bFGF) cDNA-transfected IPE (bFGF-IPE) cells in vitro.

METHODS

The RPE cells and IPE cells were isolated from adult Long Evans rats' eyes. The bFGF cDNA was transfected to the IPE using lipofection method. The bovine photoreceptor outer segments (POS) were isolated and labeled with Alexa 488 dye (fluorescent marker, EX: 494 nm, EM: 519 nm), and were applied to the cultured RPE, IPE, vector-IPE, and bFGF-IPE for 20 hours. The amount of phagocytosed POS in cells was photographed by fluorescence microscopy with fluorescein isothiocyanate (FITC) filter, and expressed as the ratio of the occupying area of fluorescence to the area of pigment epithelial cells in each observing field.

RESULTS

The phagocytic capacity of IPE and vector-IPE were about 70% of RPE, and that of bFGF-IPE increased to 150% of IPE. This increase was inhibited by pretreatment with anti-bFGF antibody to bFGF-IPE.

CONCLUSIONS

IPE showed phagocytic capacity, but it reached only 70% of that in RPE. The stable expression of bFGF promoted its function.

Gene expression screening of human mast cells and eosinophils using high-density oligonucleotide probe arrays: abundant expression of major basic protein in mast cells

Mast cells (MCs) and eosinophils are thought to play important roles in evoking allergic inflammation. Cell-type--specific gene expression was screened among 12,000 genes in human MCs and eosinophils with the use of high-density oligonucleotide probe arrays. In comparison with other leukocytes, MCs expressed 140 cell-type--specific transcripts, whereas eosinophils expressed only 34. Among the transcripts for expected MC-specific proteins such as tryptase, major basic protein (MBP), which had been thought to be eosinophil specific, was ranked fourth in terms of amounts of increased MC-specific messenger RNA. Mature eosinophils were almost lacking this transcript. MCs obtained from 4 different sources (ie, lung, skin, adult peripheral blood progenitor--derived and cord blood progenitor--derived MCs, and eosinophils) were found to have high protein levels of MBP in their granules with the use of flow cytometric and confocal laser scanning microscopic analyses. The present finding that MCs can produce abundant MBP is crucial because many reports regarding allergic pathogenesis have been based on earlier findings that MBP was almost unique to eosinophils and not produced by MCs. (Blood. 2001;98:1127-1134)