Contributions of two cytosolic glutamine synthetase isozymes to ammonium assimilation in Arabidopsis roots

Glutamine synthetase (GS) catalyzes a reaction that incorporates ammonium into glutamate and yields glutamine in the cytosol and chloroplasts. Although the enzymatic characteristics of the GS1 isozymes are well known, their physiological functions in ammonium assimilation and regulation in roots remain unclear. In this study we show evidence that two cytosolic GS1 isozymes (GLN1;2 and GLN1;3) contribute to ammonium assimilation in Arabidopsis roots. Arabidopsis T-DNA insertion lines for GLN1;2 and GLN1;3 (i.e. gln1;2 and gln1;3 single-mutants), the gln1;2:gln1;3 double-mutant, and the wild-type accession (Col-0) were grown in hydroponic culture with variable concentrations of ammonium to compare their growth, and their content of nitrogen, carbon, ammonium, and amino acids. GLN1;2 and GLN1;3 promoter-dependent green fluorescent protein was observed under conditions with or without ammonium supply. Loss of GLN1;2 caused significant suppression of plant growth and glutamine biosynthesis under ammonium-replete conditions. In contrast, loss of GLN1;3 caused slight defects in growth and Gln biosynthesis that were only visible based on a comparison of the gln1;2 single- and gln1;2:gln1;3 double-mutants. GLN1;2, being the most abundantly expressed GS1 isozyme, markedly increased following ammonium supply and its promoter activity was localized at the cortex and epidermis, while GLN1;3 showed only low expression at the pericycle, suggesting their different physiological contributions to ammonium assimilation in roots. The GLN1;2 promoter-deletion analysis identified regulatory sequences required for controlling ammonium-responsive gene expression of GLN1;2 in Arabidopsis roots. These results shed light on GLN1 isozyme-specific regulatory mechanisms in Arabidopsis that allow adaptation to an ammonium-replete environment.

Asparagine synthetase1, but not asparagine synthetase2, is responsible for the biosynthesis of asparagine following the supply of ammonium to rice roots

Asparagine is synthesized from glutamine by the reaction of asparagine synthetase (AS) and is the major nitrogen form in both xylem and phloem sap in rice (Oryza sativa L.). There are two genes encoding AS, OsAS1 and OsAS2, in rice, but the functions of individual AS isoenzymes are largely unknown. Cell type- and NH4(+)-inducible expression of OsAS1 as well as analyses of knockout mutants were carried out in this study to characterize AS1. OsAS1 was mainly expressed in the roots, with in situ hybridization showing that the corresponding mRNA was specifically accumulated in the three cell layers of the root surface (epidermis, exodermis and sclerenchyma) in an NH4(+)-dependent manner. Conversely, OsAS2 mRNA was abundant in leaf blades and sheathes of rice. Although OsAS2 mRNA was detectable in the roots, its content decreased when NH4(+) was supplied. Retrotransposon-mediated knockout mutants lacking AS1 showed slight stimulation of shoot length and slight reduction in root length at the seedling stage. On the other hand, the mutation caused an approximately 80-90% reduction in free asparagine content in both roots and xylem sap. These results suggest that AS1 is responsible for the synthesis of asparagine in rice roots following the supply of NH4(+). Characteristics of the NH4(+)-dependent increase and the root surface cell-specific expression of OsAS1 gene are very similar to our previous results on cytosolic glutamine synthetase1;2 and NADH-glutamate synthase1 in rice roots. Thus, AS1 is apparently coupled with the primary assimilation of NH4(+) in rice roots.

NADH-dependent glutamate synthase plays a crucial role in assimilating ammonium in the Arabidopsis root

Plant roots under nitrogen deficient conditions with access to both ammonium and nitrate ions, will take up ammonium first. This preference for ammonium rather than nitrate emphasizes the importance of ammonium assimilation machinery in roots. Glutamine synthetase (GS) and glutamate synthase (GOGAT) catalyze the conversion of ammonium and 2-oxoglutarate to glutamine and glutamate. Higher plants have two GOGAT species, ferredoxin-dependent glutamate synthase (Fd-GOGAT) and nicotinamide adenine dinucleotide (NADH)-GOGAT. While Fd-GOGAT participates in the assimilation of ammonium, which is derived from photorespiration in leaves, NADH-GOGAT is highly expressed in roots and its importance needs to be elucidated. While ammonium as a minor nitrogen form in most soils is directly taken up, nitrate as the major nitrogen source needs to be converted to ammonium prior to uptake. The aim of this study was to investigate and quantify the contribution of NADH-GOGAT to the ammonium assimilation in Arabidopsis (Arabidopsis thaliana Columbia) roots. Quantitative real-time polymerase chain reaction (PCR) and protein gel blot analysis showed an accumulation of NADH-GOGAT in response to ammonium supplied to the roots. In addition the localization of NADH-GOGAT and Fd-GOGAT did not fully overlap. Promoter-β-glucuronidase (GUS) fusion analysis and immunohistochemistry showed that NADH-GOGAT was highly accumulated in non-green tissue like vascular bundles, shoot apical meristem, pollen, stigma and roots. Reverse genetic approaches suggested a reduction in glutamate production and biomass accumulation in NADH-GOGAT transfer DNA (T-DNA) insertion lines under normal CO2 condition. The data emphasize the importance of NADH-GOGAT in the ammonium assimilation in Arabidopsis roots.

NADH-dependent glutamate synthase participated in ammonium assimilation in Arabidopsis root

Higher plants have 2 GOGAT species, Fd-GOGAT and NADH-GOGAT. While Fd-GOGAT mainly assimilates ammonium in leaves, which is derived from photorespiration, the function of NADH-GOGAT, which is highly expressed in roots, (1) needs to be elucidated. The aim of this study was to clarify the role of NADH-GOGAT in Arabidopsis roots. The supply of ammonium to the roots caused an accumulation of NADH-GOGAT, while Fd-GOGAT 1 and Fd-GOGAT 2 showed no response. A promoter-GUS fusion analysis and immunohistochemistry showed that NADH-GOGAT was located in non-green tissues like vascular bundles, shoot apical meristem, pollen, stigma, and roots. The localization of NADH-GOGAT and Fd-GOGAT was not overlapped. NADH-GOGAT T-DNA insertion lines showed a reduction of glutamate and biomass under normal CO2 conditions. These data emphasizes the importance of NADH-GOGAT in the ammonium assimilation of Arabidopsis roots.

anti-tumor effect of AlkB homolog 3 knockdown in hormone- independent prostate cancer cells

Castrate resistant prostate cancer (CRPC) is a disease that is resistant to both hormone therapy and chemotherapy. At present, no curative therapy for CRPC has been established. Therefore, it is necessary to determine a novel molecular target for the development of therapeutic agents. We previously reported that AlkB homolog 3 (ALKBH3) is highly expressed in prostate cancer but not in benign prostatic hyperplasia or in normal prostate epithelium and that the expression levels of ALKBH3 protein are significantly correlated with the hormone-independent state of prostate cancer. Moreover, ALKBH3 regulates the invasion of prostate cancer cells via the regulation of matrix metalloproteinase 9. Here, we show that ALKBH3 gene silencing markedly induces apoptosis in hormone-independent prostate cancer cell line DU145 but not in the normal prostate epithelial cell line PNT2. Moreover, the in vivo tumorigenicity of DU145 cells was significantly inhibited by the administration of ALKBH3 siRNA. Furthermore, the anchorage-independent growth of DU145 cells was inhibited by ALKBH3 knockdown and promoted by ALKBH3 overexpression, significantly. ALKBH3 shRNA-expressing prostate cancer cells formed significantly smaller tumors than those of control shRNA transfectants in an in vivo xenograft model. These findings suggest that ALKBH3 is a promising target molecule for the development of CRPC therapeutic agents.

Detection of RB, p16/CDKN2 and p15(INK4B) gene alterations with immunohistochemical studies in human prostate carcinomas

To examine the status of cell cycle-inhibitory genes in human prostate carcinoma, we investigated alterations of RE (retinoblastoma), p16/CDKN2 and p15(INK4B) genes in 32 adenocarcinomas with immunohistochemistry. PCR-single-strand conformation polymorphism (SSCP) was used to examine all 27 exons of the RE gene, exons 1 to 3 of the p16/CDKN2 gene and exons 1 and 2 of the p15(INK4B) gene for mutations. Loss of heterozygosity (LOH) for the RE gene was probed by restriction fragment length polymorphism (RFLP) analysis. In addition, coordinate samples were subjected to immunohistochemical studies for reactivity to RE and p16 protein. The RE gene alterations were detected in 5 of the 32 tumors (16%); of these, only one mutation, a missense substitution, occurred within an exon. The remaining four single base insertions or deletions were found within introns of the RE gene and no mutational event was detected in its promoter region. LOH involving intron 17 of RB was detected in three cases of 10 informative tumors (30%). Intragenic mutations were also present in 3 of the 32 tumors in the p16/CDKN2 gene. In contrast, no mutational events were found in the p15(INK4B) gene in the tumors. Only one tumor had both a p16/CDKN2 mutation and LOH of the RE gene. Expression of pRB was absent or reduced in 16 cancers, while p16 expression was present in all cases to varying degrees. The results suggest that p16/CDKN2 gene mutations occur rarely and intragenic mutation, but not LOH,of the RE gene is not required in prostatic tumorigenesis.

p53 tumor suppressor gene and ras oncogene mutations in hypopharyngeal squamous cell carcinomas

To examine the potential role of p53 and ras gene mutations in hypopharyngeal tumorigenesis, twenty-eight primary hypopharyngeal carcinomas, obtained at biopsy or total pharyngolaryngectomy, were investigated. Exons 5 through 9 of the p53 gene and exons 1 and 2 of the H-, K-, N-ras gene were screened using a combination of immunohistochemistry and single-strand conformation polymorphism analysis of polymerase chain reaction products (PCR-SSCP). The targeted DNA sequences coding for p53 and ras were confirmed by direct DNA sequencing. Point mutations of p53 were found in 9 (32.1%) of the 28 cases, including one with a double mutation, 3 in exon 5, 1 in exon 6, 2 in exon 7 and 4 in exon 8. Positive nuclear immunostaining for p53 was evident in 14 (50.0%) lesions. Seven (25.0%) of the 28 demonstrated point mutations in the H-rns gene, and 11 (39.3%) showed positive cytoplasmic staining for I as. The 5-year survival rate was worse with than without p53 overexpression (p <0.05). The present results suggest that gene mutations, although they occur at a relatively low incidence, are involved in hypopharyngeal tumorigenesis with p53 expression being a prognostic factor.

Immunohistochemical detection of CDKN2, retinoblastoma and p53 gene products in primary astrocytic tumors

The expressions of p16(INK4), retinoblastoma (RB) and p53 protein were immunohistochemically examined in 70 primary astrocytic tumors. In 58 patients with high grade astrocytoma (18 anaplastic astrocytomas and 40 glioblastomas), 30 (51.1%) and 15 (25.9%) cases were undetectable for p16(INK4) and pRB, respectively, but their lack occurred infrequently in 12 low grade astrocytomas. The expression of p16(INK4) was inversely correlated with that of PRB, especially in glioblastomas. Accumulation of p53 was detected in 32 (45.7%) of 70 cases without any dependence on the grade. A deregulation of three tumor suppressor gene products most often occurs singly. Only patients with negative staining for pRB were significantly associated with a shorter survival time. Our findings suggest that loss of functional pRB at the G1/S check point may represent an important step in glioblastoma development and have a stronger negative impact on clinical outcome than p16(INK4) or p53 aberrations.

Prognostic significance of CD45RO+ memory T cells in renal cell carcinoma

Background:

Memory T cells are well known to have a critical role for host defense in humans. However, their role in actual human cancer remains largely unknown. In this study, we tried to reveal the clinical importance of tumour-infiltrating CD45RO+ memory T cells in renal cell carcinoma (RCC).

Methods:

We analysed 105 patients with RCC, who received radical or partial nephrectomy. Those were 65 in TNM stage I, 7 in stage II, 15 in stage III, and 18 in stage IV, respectively. CD45RO expression was evaluated by immunohistochemistry. CD4 and CD8 expressions were also systematically assessed in the same manner.

Results:

Patients with higher TNM stage or high nuclear grade were found to have higher densities of CD45RO. Furthermore, CD45RO status was positively correlated with preoperative C-reactive protein level. In prognostic analysis, CD45RO+lo patients had a significantly better prognosis than CD45RO+hi patients. There was also a significant difference between CD4+lo and CD4+hi groups, whereas no significant difference was observed in CD8 T-cell status. Finally, multivariate analysis revealed that CD45RO+ status was the independent prognostic factor for patient overall survival.

Conclusion:

CD45RO+ memory T-cell status has a significant independent prognostic value, indicating that the adaptive immune response is functionally critical in human RCC.

Clinical importance of B7-H3 expression in human pancreatic cancer

Background:

B7-H3 is a new member of the B7 ligand family and regulates T-cell responses in various conditions. However, the role of B7-H3 in tumour immunity is largely unknown. The purpose of this study was to evaluate the clinical significance of B7-H3 expression in human pancreatic cancer and the therapeutic potential for cancer immunotherapy.

Methods:

We investigated B7-H3 expression in 59 patients with pancreatic cancer by immunohistochemistry and real-time PCR. Furthermore, we examined the anti-tumour effect of B7-H3-blocking monoclonal antibody in vivo in a murine pancreatic cancer model.

Results:

Tumour-related B7-H3 expression was abundant in most human pancreatic cancer tissues and was significantly higher compared with that in non-cancer tissue or normal pancreas. Moreover, its expression was significantly more intense in cases with lymph node metastasis and advanced pathological stage. B7-H3 blockade promoted CD8⁺ T-cell infiltration into the tumour and induced a substantial anti-tumour effect on murine pancreatic cancer. In addition, the combination of gemcitabine with B7-H3 blockade showed a synergistic anti-tumour effect without overt toxicity.

Conclusion:

Our data show for the first time that B7-H3 may have a critical role in pancreatic cancer and provide the rationale for developing a novel cancer immunotherapy against this fatal disease.

Isoflurane exerts a short-term but not a long-term preconditioning effect in neonatal rats exposed to a hypoxic-ischaemic neuronal injury

BACKGROUND

Isoflurane has been shown to induce tolerance against ischaemic injury in adult rodents. Although the delayed preconditioning effect of isoflurane has been demonstrated in neonatal rat pups, the acute preconditioning effects of isoflurane remained undetermined. The present study was therefore conducted to evaluate the acute preconditioning efficacy of isoflurane in neonatal rats subjected to a hypoxic-ischaemic (HI) injury.

METHODS

Post-natal day 7 pups were exposed to 1 or 2% isoflurane in oxygen for either 30, 60 or 90 min. Fifteen minutes after isoflurane exposure, the pups were subjected to an HI injury induced by left common carotid artery ligation and exposure to 8% oxygen for 2 h. Pups not exposed to isoflurane or not subjected to HI served as controls. Histopathologic injury to the cortex and hippocampus was evaluated 7 and 49 days after HI.

RESULTS

Isoflurane 2% exposure for 60 or 90 min before HI induced tolerance in the hippocampus and the number of normal neurons in the CA1 sector 7 days after HI was significantly greater than in non-preconditioned animals. This protective efficacy of isoflurane preconditioning was not observed 49 days after HI.

CONCLUSIONS

Exposure of 2% isoflurane for at least 60 min is required to induce tolerance against HI injury in rat pups. However, this neuroprotective efficacy results in only transient neuroprotection.

Effect of continuous morphine infusion on hypoxic-ischaemic brain damage of neonatal rats

BACKGROUND

Opioids are commonly administered to critically ill neonates and infants for general anaesthesia and sedation. However, the clinical safety of these drugs, especially the effects on hypoxic-ischaemic damage of the developing brain, has not been well investigated. The present study was therefore conducted to investigate the effects of continuous morphine infusion on brain damage after hypoxic-ischaemic insults in neonatal rats.

METHODS

Seven-day-old Sprague-Dawley rats were subjected to left common carotid artery ligation followed by a 90-min exposure of 8% oxygen. The rats were administered morphine (0.1, 0.3 or 1 mg/kg/h) or saline continuously for 72 h using osmotic minipumps. Seven days later, the rats were weighed and their brains were morphologically categorized into groups based on the following grades: 0=normal, 1=mild atrophy, 2=moderate atrophy, 3=atrophy with cystic cavitation <3 mm and 4=cystic cavitation >3 mm. For histological assessment, the ratio of the surviving neurons (ipsilateral/contralateral) was calculated in the cornu ammonis fields, CA1 and CA3, and the dentate gyrus (DG).

RESULTS

One week after recovery (P14), the rats in the 1 mg/kg/h group showed significantly poorer weight gain compared with the other groups. However, the morphological score of the brains and the ratio of the surviving neurons in the CA1, CA3 and DG were similar among the groups.

CONCLUSION

Our results indicate that continuous administration of morphine does not worsen brain damage 7 days after hypoxic-ischaemic insults in neonatal rats.

Impact of a left-lobe graft without modulation of portal flow in adult-to-adult living donor liver transplantation

In adult-to-adult living donor liver transplantation (LDLT), left-lobe grafts can sometimes be small-for-size. Although attempts have been made to prevent graft overperfusion through modulation of portal inflow, the optimal portal venous circulation for a liver graft is still unclear. Hepatic hemodynamics were analyzed with reference to graft function and outcome in 19 consecutive adult-to-adult LDLTs using left-lobe grafts without modulation of graft portal inflow. Overall mean graft volume (GV) was 398 g, which was equivalent to 37.8% of the recipient standard liver volume (SV). The GV/SV ratio was less than 40% in 13 of the 19 recipients. Overall mean recipient portal vein flow (PVF) was much higher than the left PVF in the donors. The mean portal contribution to the graft was markedly increased to 89%. Average daily volume of ascites revealed a significant correlation with portal vein pressure, and not with PVF. When PVP exceeds 25 mmHg after transplantation, modulation of portal inflow might be required in order to improve the early postoperative outcome. Although the study population was small and contained several patients suffering from tumors or metabolic disease, all 19 patients made good progress and the 1-year graft and patient survival rate were 100%. A GV/SV ratio of less than 40% or PVF of more than 260 mL/min/100 g graft weight does not contraindicate transplantation, nor is it necessarily associated with a poor outcome. Left-lobe graft LDLT is still an important treatment option for adult patients.

Effects of delta-opioid receptor stimulation and inhibition on hippocampal survival in a rat model of forebrain ischaemia

BACKGROUND

It has been reported that delta-opioid (DOP) receptor agonists may be neuroprotective in the central nervous system. However, the DOP agonist [d-Ala(2), d-Leu(5)]enkephalin (DADLE) does not produce neuroprotection in severe forebrain ischaemia. The aim of this study was to examine the effects of DADLE on hippocampal neurone survival against less severe forebrain ischaemia.

METHODS

Intraperitoneal injection of DADLE (0 or 16 mg kg(-1)) in male Sprague-Dawley rats was performed 30 min before ischaemia. Severe (10 min), moderate (8 min), or mild (6 min) forebrain ischaemia was produced by bilateral carotid occlusion combined with hypotension (35 mm Hg) under isoflurane (1.5%) anaesthesia. Naltrindole (10 mg kg(-1)) (DOP antagonist) was administered 30 min before DADLE in order to confirm DOP receptor activation in the neuroprotective efficacy of DADLE. Naltrindole alone was also administered 30 min before ischaemia to examine endogenous DOP agonism as a self-protecting mechanism against ischaemia. All animals were evaluated neurologically and histologically after a 1 week recovery period.

RESULTS

DADLE improved neurone survival in hippocampal CA3 and dentate gyrus (DG) sectors. CA1 neurones were not protected against moderate and mild ischaemia. Naltrindole abolished DADLE neuroprotection in the CA3 and DG after both moderate and mild ischaemia. Interestingly, regardless of co-administration of DADLE, naltrindole significantly worsened neuronal injury in the CA1 region after mild ischaemia.

CONCLUSIONS

These results suggest that DADLE provides limited neuroprotection to relatively ischaemia-resistant regions but not to selectively vulnerable regions. This was probably mediated by DOP stimulation. Pre-ischaemic treatment with a DOP antagonist, regardless of co-administration of DADLE, worsened neuronal damage at the selectively vulnerable regions only after mild forebrain ischaemia. These data suggest that DOP activation with endogenous DOP ligand may be involved in self-protecting ischaemia-sensitive regions of the brain.

A study for establishment of individualized chemotherapy for colorectal cancer based on the individual 50% inhibitory area under the concentration curve (AUCIR50) using the collagen gel droplet embedded culture-drug sensitivity test (CD- DST)

14553

Background: The drug sensitivity of tumor cells is one of the key issues to explore in individualized 5-fluorouracil (5-FU) based chemotherapy for colorectal cancer patients. We reported that growth inhibition rate (IR) and area under the concentration curve (AUC) approximated to a logarithmic curve using the collagen gel droplet embedded culture-drug sensitivity test (CD-DST) in ASCO 2003 (#1283). We also reported that the individual 50% inhibitory area under the concentration curve (AUC IR50) could be obtained using the individual AUC-IR curve in ASCO 2006 (#13560). The aim of this study was to evaluate the achievement of the individual AUCIR50 in 5-FU based adjuvant chemotherapy for the establishment of individualized chemotherapy. Methods: Surgical specimen was obtained from resectable 33 CRC patients without any preoperative chemotherapy during 2001 to 2005. 5-FU based adjuvant chemotherapy was administered in all patients. CD-DST was performed under 6–9 different conditions. The individual AUCIR50 was obtained from the individual AUC-IR curve. The patients were divided into 2 groups, the achieved group and the non-achieved group. In the achieved group, total administered AUC was more than the individual AUCIR50 and in non-achieved group, the total administered AUC was less than the individual AUCIR50. Recurrence rates were evaluated from the 2 groups. Results: In all patients, the recurrence rates were 6.7% (1/15) in the achieved group and 27.8% (5/18) in the non-achieved group. In the colon cancer patients, the recurrence rates were 8.3% (1/12) in the achieved group and 10.0% (1/10) in the non-achieved group. In the rectal cancer patients, the recurrence rates were 0% (0/3) in the achieved group and 50.0% (4/8) in the non-achieved group. Conclusions: The recurrence rate of the achieved group was lower than that of the non-achieved group. Therefore, this study demonstrated that the achievement of the individual AUCIR50 could be a prerequisite of individualized 5-FU based adjuvant chemotherapy.

No significant financial relationships to disclose.

Prostatic volume and volume-adjusted prostate-specific antigen as predictive parameters for prostate cancer patients with intermediate PSA levels

The object of the study was to examine the usefulness of volume-adjusted prostate-specific antigen (PSA) parameters for prediction of prostate cancer in the patients with intermediate PSA levels. The subjects were 235 patients with intermediate PSA levels (range: 4.1-10.0 ng/ml) whose prostate volume (PV) and prostate transition zone volume (TZV) were evaluated between August 1996 and April 2004. PSA, PV, TZV, PSA density (PSAD) (PSA/PV) and PSA transition zone density (PSATZD) (PSA/TZV) were assessed with the receiver operating characteristic (ROC) curve and the area under the curve (AUC). Simple and multivariate logistic regression analyses were used to analyze the odds ratios of age, PSA, PSAD, PSATZD, PV, TZV, digital rectal examination (DRE) and transrectal ultrasonography (TRUS) findings. Fifty-five patients (23.4%) of 235 patients had biopsy-proven prostate cancer. The univariate analysis revealed significant differences in the mean values of age, PSAD, PSATZD, PV, TZV and DRE between the patients with cancer and the non-cancer patients. The ROC curve analysis revealed that PV, TZV, PSAD and PSATZD had significant predictive values as compared with that of PSA. However, there was no difference in AUC between them. The stepwise logistic regression analysis showed that the age, PV, PSATZD and DRE had significant predictive values, and that PSATZD had the most predictive power. In conclusion, both PSAD and PSATZD had significant predictive values in discriminating prostate cancer. Furthermore, the stepwise logistic regression analysis showed that PSATZD had the strongest predictive value.

Frontal cerebral blood flow change associated with infant-directed speech

OBJECTIVE

To examine the auditory perception of maternal utterances by neonates using near-infrared spectroscopy (NIRS).

METHODS

Twenty full-term, healthy neonates were included in this study. The neonates were tested in their cribs while they slept in a silent room. First, two probe holders were placed on the left and right sides of the forehead over the eyebrows using double-sided adhesive tape. The neonates were then exposed to auditory stimuli in the form of infant-directed speech (IDS) or adult-directed speech (ADS), sampled from each of the mothers, through an external auditory speaker.

RESULTS

A 2 (stimulus: IDS and ADS) x 2 (recording site: channel 1 (right side) and channel 2 (left side)) analysis of variance for these relative oxygenated haemoglobin values showed that IDS (Mean = 0.25) increased brain function significantly (F = 3.51) more than ADS (Mean = -0.26).

CONCLUSIONS

IDS significantly increased brain function compared with ADS. These results suggest that the emotional tone of maternal utterances could have a role in activating the brains of neonates to attend to the utterances, even while sleeping.

Genetic analysis to complement histopathological diagnosis of brain tumors

Gliomas, the most frequent tumors originating in the human nervous system, are divided into various subtypes. Currently, microscopic examination alone is insufficient for classification and grading so that genetic profiles are increasingly being emphasized in recognition of the emerging role of molecular diagnostic approaches to glioma classification. Glioblastomas (WHO grade IV) may develop de novo (primary glioblastomas) or through progression from lower-grade astrocytomas (secondary glioblastomas), while both glioblastomas show similar histological features. In contrast, they do constitute distinct disease entities that evolve through different genetic pathways, and are likely to differ in prognosis and response to therapy. Oligodendrogliomas (WHO grade II) account for 2.7% of brain tumors and 5-18% of all gliomas. Since this tumor is recognized as a particular subtype of glioma that shows remarkable responses to chemotherapy, a correct diagnosis is of prime importance. The difficulty is that histological differentiation of oligodendrogliomas from diffuse astrocytomas is highly subjective in cases without typical morphological features and there is a lack of reliable immunohistochemical markers. While histological distinction of low-grade gliomas from reactive astrocytes is also often difficult, reactive astrocytes usually lack genetic alterations. More biological and molecular approaches to glioma classification thus appear warranted to provide improved means to achieve correct diagnoses.