[The stability and repeatability of radiomics features based on lung diffusion-weighted imaging].

Objective: To evaluate the feasibility, robustness and reproducibility of radiomics features derived from lung diffusion-weighted imaging (DWI). Methods: Thirty patients with pulmonary nodules/masses who underwent magnetic resonance imaging examination in the Department of Radiology, the First Affiliated Hospital of Guangzhou Medical University, from January 4 2019 to May 5 2019, including 16 males and 14 females, aged from 27 to 69 (57±11) years, were prospectively collected. Planar echo imaging (EPI) -DWI and fast spin-echo (TSE) -DWI scans were performed under free-breathing conditions. Each scan was repeated at an interval of 5 minutes, and the corresponding apparent diffusion coefficient (ADC) maps were reconstructed. Each DWI and ADC sequence (a total of eight groups of images) were manually segmented by two radiologists, and a total of 396 radiomics features in 6 categories were extracted from each group of images. Consistency correlation coefficient (CCC) and dynamic range (DR) were used to evaluate the robustness of features between two scans, and stable features were defined as both CCC values and DR values ≥0.85. Intra-observer and interobserver reproducibility were evaluated by intra-group correlation coefficient (ICC), and ICC values≥0.75 was considered to be good reproducibility. Results: Regardless of EPI or TSE technique, the number of robust features extracted fromDWI (TSE: n=197, EPI: n=169) were higher than that of the corresponding ADC (TSE: n=126, EPI: n=148). The proportion of robust features of TSE-DWI、EPI-DWI、TSE-ADC、EPI-ADC was 49.7% (197/396), 42.7% (169/396), 31.8% (126/396) and 37.4% (148/396), respectively. Of the 396 features, 54 (13.6%) of them demonstrated great robustness (CCC and DR≥0.85) and interobserver and interobserver reproducibility (ICC≥0.75) across all sequences. Conclusions: Radiomics features derived from lung DWI showed robustness and reproducibility. Different sequences and different feature clusters have different proportions of stable features, and some features have good robustness and reproducibility between different scans, different observers, and even different sequences.

[Current advances in research of burning mouth syndrome: biological nerve and social psychology patterns].

Burning mouth syndrome (BMS) is a complex chronic disorder characterized symptomatically by burning sensation mainly localized in the tongue with no specific lesions. Its etiology is not fully understood. Due to the persistent pain and unsatisfactory outcome of treatment, patients with high expectation when seeking medical advice easily feel discontent after treatment, which might cause medical dispute. This review introduces the epidemiology, manifestations, etiology, diagnosis, classification and treatment of BMS. The authors hope the current advances about BMS, mainly focus on the etiology of biological nerve and social psychology, may help the clinicians in treatment of BMS.

MicroRNA-506-3p inhibits proliferation and promotes apoptosis in ovarian cancer cell via targeting SIRT1/AKT/FOXO3a signaling pathway.

Ovarian cancer (OC) is one of the most common tumors in females. Growing evidence shows that microRNA-506-3p (miR-506-3p) is downregulated in OC tissues. The purpose of this study was to investigate the mechanism of miR-506-3p in modulating OC. Quantitative reverse transcriptase PCR (qRT-PCR) was employed to investigate the expression of miR-506-3p and its target in OC tissues or cell lines. CCK-8 or colony formation assay was used to examine cell viability or proliferation, respectively. Flow cytometry was demonstrated to detect cell apoptosis. Western blot was then applied to analyze underlying mechanisms. The potential target of miR-506-3p was examined via luciferase reporter assay. MiR-506-3p was significantly downregulated in both human OC tissues and cell lines. Overexpression of miR-506-3p not only decreased cell viability of OC cell lines but also promoted cell apoptosis, thus inhibiting OC progression. Moreover, SIRT1 (Sirtuin 1) was found to be a direct target of miR-506-3p, and SIRT1 expression was negatively regulated by miR-506-3p in OC cell lines. Further investigation revealed that overexpression of SIRT1 could promote cell viability as well as inhibit cell apoptosis, showing the reversed effect on OC progression compared to miR-506-3p. Lastly, AKT (Protein kinase B) /FOXO3a (Forkhead box O3) signaling pathway was inactivated by miR-506-3p while activated by SIRT1, relating to regulation of miR-506-3p on OC progression. Our results revealed a novel mechanism by which miR-506-3p inhibited proliferation while promoted apoptosis of OC via inactivation of SIRT1/AKT/FOXO3a signaling pathway, suggesting that miR-506-3p might be a potential target for OC.

Subtype-specific inherited predisposition to pemphigus in the Chinese population.

BACKGROUND: Pemphigus is a group of rare life-threatening mucocutaneous autoimmune diseases, presenting mainly as two subtypes: pemphigus vulgaris (PV) and pemphigus foliaceus (PF). Inherited predispositions to pemphigus have long been speculated but they remain poorly understood. OBJECTIVES: To identify common and specific nongenetic and genetic factors associated with pemphigus and its subtypes in the Chinese population. METHODS: A genome-wide association study (GWAS) was performed in 496 unrelated patients with pemphigus (including 365 with PV and 104 with PF) and 1105 controls without pemphigus. RESULTS: A sex preference was observed only in PV (57·5% female) and not in PF (47·1% female). For male patients only, the mean age at diagnosis was significantly lower for PV than for PF (P < 0·001). The strongest associated single-nucleotide polymorphisms are in the human leucocyte antigen (HLA) region: rs70993900 (PV; P = 1·5 × 10-45 ) and rs9469220 (PF; P = 1·1 × 10-8 ). HLA-DQB1*05:03 ranks at the top (P = 4·7 × 10-40 ; odds ratio 12·4) in both subtypes, with significantly different risk allele frequency (RAFPV = 34·2% vs. RAFPF = 18·8% vs. RAFcontrol = 4·4%), whereas HLA-DRB1*14:01 and HLA-DRB1*04:06 are PV specific. HLA-DQB1*03:03 and HLA-DQB1*03:02 show significant subtype specificity in opposite directions. All of these associations were validated in the replication series with 147 cases of pemphigus and 604 controls. Multiple novel non-HLA susceptibility loci were also identified in the GWAS. CONCLUSIONS: This study represents the largest GWAS on pemphigus in the Chinese population published to date, and has allowed us to identify HLA haplotypes significantly shared between or specific to the two main subtypes of pemphigus.

[A retrospective study of tumor and fertility outcomes after fertility-sparing surgical treatment of patients with borderline ovarian tumors].

Objective: To study tumors and fertility outcomes after fertility-sparing surgical treatment with borderline ovarian tumors (BOT). Methods: One hundred and nineteen patients with BOT enrolled from 3 hospitals between January 2004 and January 2017 were analysed retrospectively.The clinical data and follow-up results were obtained and analyzed. Results: Among the 119 BOT patients, 55 patients underwent fertility-sparing surgery.The median age was 43 years (interquartile range: 15-80 years). There were 103 patients (86.55%) in stage Ⅰ, and 16 patients (13.45%) in stage Ⅱ and above.The median follow up time was 68 months (range: 4-155). (1)Tumor outcomes: 13 patients recurred and 3 patients died.Progression free survival (PFS) and the overall survival rate had no significant difference between the two groups (85.45% vs 92.19% P=0.309, 96.4% vs 98.4% P=0.492). PFS was related to FIGO stage, invasive implantation and chemotherapy by univariate analysis (P<0.05). The multivariate Cox regression model analysis showed that FIGO stage and invasive implantation were independent prognostic factors for PFS (P<0.05). (2) Pregnancy outcomes: 28 patients had a planned for pregnancy in fertility-sparing group, with 13 (46.43%) of them were pregnancy. Conclusions: FIGO stage and invasive implantation were the important factors of prognosis.Fertility-sparing surgery is safe and feasible to preserve the fertility of young patients.

Clinical and cytogenomic studies in a case of infertility associated with a nonmosaic dicentric Y chromosome.

In this study, a short stature male with infertility is reported. Semen analysis and serum concentrations of FSH, LH, T and PRL were estimated. Chromosome analysis was performed on lymphocytes obtained from both the male and his parents. Cytogenomic studies were performed by fluorescent in situ hybridisation and the CytoScan(™)  HD array analysis to detect Y chromosomal rearrangements and copy number mutations. Semen analysis showed severe oligozoospermia. Numerous spermatogenic cells were observed in the semen, and approximately 60% of the cells examined in semen were primary spermatocytes, showing spermatogenic arrest at the primary spermatocyte level. Cytogenomic studies of blood revealed his karyotype which was 46,X,i(Y) (p11.32) (Yqter→Yp11.32::Yp11.32→Yqter).ish (DYZ3++, SRY++, SHOX-). array (PLCXD1→SHOX) ×1,(SRY →GOLGA2P3Y)×2, (DHRSX→ ASMT, SPRY3 →IL9R)×3. The rearrangement Y chromosome is de novo. This is the first case reported with a nonmosaic 46,X, i (Y) (p11.32), which will be useful to estimate the infertility phenotype-molecular karyotype correlation. Haploinsufficiency of short stature homeobox-containing gene is primarily responsible for the short stature. Aberrations in pseudoautosomal region 1 on the rearranged Y chromosome may result in the deficiency of X-Y pairing or recombination, ultimately lead to the spermatogenic failure.

A novel nonsense mutation in the sedlin gene (SEDL) causes severe spondyloepiphyseal dysplasia tarda in a five-generation Chinese pedigree.

Spondyloepiphyseal dysplasia tarda (SEDT) is an X-linked recessive osteochondrodysplasia characterized by disproportionately short stature and degenerative joint disease. The objective of this study was to describe a novel nonsense mutation in the sedlin gene (SEDL) causing severe SEDT in a large Chinese pedigree. The clinical features of all affected individuals and female carriers were presented. Four affected males of the family were diagnosed with SEDT according to their clinical and radiological features. Direct DNA sequencing of SEDL was performed. Reverse-transcription polymerase chain reaction (RT-PCR) experiments of total RNA from blood lymphocytes were performed to confirm the defect in SEDL. DNA sequencing revealed that all of the affected males carried a nonsense mutation (c.61G>T) in SEDL that has not been previously reported. The c.61G>T mutation resulted in a premature translation termination codon (GAG>TAG) at amino acid position 21 (p.E21*), and was predicted to initiate the degradation of mutant transcripts through the nonsense-mediated mRNA decay pathway. Two female carriers showed typical sequencing chromatograms of a heterozygote. Following genetic counseling, individual IV7 gave birth to a healthy baby. Therefore, identification of the novel nonsense mutation (c.61G>T) in the SEDT family enables carrier detection, genetic counseling, and prenatal diagnosis. The detailed genotype/phenotype descriptions contribute to the SEDL mutation spectrum. The continued identification of mutations in SEDT patients will greatly aid further elucidation of the role of the sedlin protein in normal bone growth.

Survey of attitude and knowledge of reproductive health among middle school students in Luoyang, China.

The aim of this study was to assess the knowledge and attitude of AIDS and sexual behavior of middle school students. Structural questionnaires were designed to interview 1980 junior and senior middle school students about their basic knowledge, attitude, and behavior with respect to AIDS and sexual behavior. Students were recruited from the six most common middle schools of the six regions in Luoyang City of the Henan Province of China by cluster sampling from September to December of 2004. Results showed that 54.5% of students had not learned about the prevention of HIV/AIDS in school, and 38.3% of students did not have any knowledge about the route of transmission of HIV/AIDS. Furthermore, 91.2% of students were reluctant to share a classroom with HIV/AIDS patients. Approximately 21.7% of students had read books, watched videos, and consulted other media related to sex, 1.1% of students had had sexual intercourse during high school, and 80.5% believed that health education on HIV/AIDS and sex was necessary. The results of this survey showed that middle school students have little knowledge about HIV/AIDS and sex. Therefore, health education programs for HIV/AIDS prevention and sexual health should be developed as soon as possible to help students peacefully get through a sexually puzzling period of life.

Overexpression of Id3 induces apoptosis of A549 human lung adenocarcinoma cells.

OBJECTIVES: Inhibitor of differentiation 3 (Id3) protein has been implicated in the control of multiple cell death signalling pathways and in aetiology of numerous diseases. The aims of this study were to construct a recombinant eukaryotic expression vector (pEGFP/Id3), containing human Id3 (hId3) fused with enhanced green fluorescent protein (EGFP), and to determine effects of ectopic Id3 overexpression, on human lung adenocarcinoma cell (A549) proliferation. MATERIALS AND METHODS: Human Id3 cDNA was inserted into pEGFP-N1 vector to yield the recombinant eukaryotic expression vector pEGFP/Id3. Cells were transfected with pEGFP or pEGFP/Id3, and proliferation of EGFP-expressing cells was monitored by flow cytometry (FCM) and confocal fluorescence microscopy. RT-PCR, immunoblotting and immunocytochemistry were used to assess Id3 mRNA transcription and protein expression. Apoptosis was evaluated by Annexin V/7-AAD staining and FCM, while nuclear morphology of apoptotic cells was examined using Hoechst 33258 staining. RESULTS: Over 4 days transfection with pEGFP, the proportion of EGFP-positive A549 cells peaked at approximately 60% by 48 h and remained stable over the next 48 h. In contrast, the proportion of EGFP-positive cells in cultures transfected with pEGFP/Id3 decreased from a peak of 60% at 48 h to <5% at 96 h, suggesting that Id3 expression inhibited cell proliferation or survival. Annexin V/7-AAD and Hoechst 33258 staining revealed significantly higher rates of apoptosis in pEGFP/Id3-transfected cells. CONCLUSION: Overexpression of Id3 triggered apoptosis in A549 human lung adenocarcinoma cells, implicating Id3 in negative control of tumour growth. These Id3-induced pro-apoptotic signalling pathways require further study, but this preliminary investigation suggests that Id3 regulation could be exploited in anti-tumour therapies.

A rare Y chromosome constitutional rearrangement: a partial AZFb deletion and duplication within chromosome Yp in an infertile man with severe oligoasthenoteratozoospermia.

We report a case of an infertile man with severe oligoasthenoteratozoospermia with a partial azoospermia factor b (AZFb) deletion and duplication region within chromosome Yp11.2. The hormonal profile was normal for serum concentrations of follicle-stimulating hormone, luteinizing hormone, testosterone and oestradiol. The patient, who showed a 46,XY karyotype, had an approximate 2.4 Mb inherited duplication region in Yp11.2 and a de novo partial AZFb deletion, which spanned 5.25 Mb including eight protein coding genes and four non-coding transcripts, but did not remove the RBMY gene family. Both proximal and distal breakpoints of the deletion were outside any palindromic region or inverted repeat sequence and intra-chromosomal non-allelic homologous recombination could not have been the deletion mechanism. The partial AZFb deletion in our case diminished sperm production, but did not completely extinguish spermatogenesis. Considering severe oligozoospermia, spermatozoa in the patient's ejaculate were used for intracytoplasmic sperm injection, resulting in two twin pregnancies.

A SNP in the miR-27a gene is associated with litter size in pigs.

MicroRNAs (miRNAs) are 20-25 nt, endogenous non-coding RNA molecules that act by binding to the complementary sequence of target messenger RNAs. Many evidences showed that miRNAs were involved in the process of germ proliferation and differentiation. In the present study, miR-27a gene was selected as a candidate gene for litter size due to its biological function, its location near a mummified pigs QTL, and its differentially expressed profile in Large White and Chinese Erhualian PMSG-hCG stimulated preovulatory ovaries. By comparative sequencing of miR-27a gene in Large White and Chinese Meishan pigs, one SNP (T/C) which created an additional HpaII site was detected. Then associations of this SNP with litter size traits were assessed in Large White (n=142) and DIV (n=140) pig populations. The statistical analysis demonstrated that AA differed from AB (P<0.01) and BB (P<0.05) for total number of piglets born in the first parities, and also differed from AB (P<0.01) for the number of piglets born alive in all parities (P<0.05) in DIV pigs. No significant difference was observed between different genotypes in Large White pigs.

Is flow cytometry really adapted to the determination of sperm concentration?

It has been reported that flow cytometry can be used as a reference procedure to determine sperm concentrations in quality control schemes in andrology laboratories, but there are no convincing quality control data. To understand comprehensively whether flow cytometry can be used to determine sperm concentration, sperm concentrations of 85 human semen samples were detected using three different methods, namely flow cytometry, computer-assisted semen analysis (CASA) and manual counting with a cell-VU chamber. The bead concentrations of both low [(18+/-2.5)x10(6)/mL] and high [(35+/-5)x10(6)/mL] pre-calibrated standard latex bead solutions were also determined with flow cytometry. The results showed that bead concentrations of both low and high pre-calibrated standard latex bead solutions counted five times with flow cytometry were (21.37+/-0.85)x10(6)/mL and (45.95+/-1.76)x10(6)/mL, respectively. Coefficient variances (CVs) and relative errors (REs) were 4%, 15.51% and 3.84%, 31.3% for low and high latex bead solutions, respectively. The overall correlation between values measured with flow cytometry and values measured with the cell-VU chamber and the CASA system was significant. However, flow cytometry overestimated the sperm concentration by 109% compared to the results with the cell-VU chamber. Moreover, for the azoospermic samples analysed, the sperm concentration was estimated at 0.12 (range from 0.04 to 0.24)x10(6)/mL. In conclusion, the data demonstrated that flow cytometry can result in an overestimation of both bead counting and sperm concentration, suggesting that flow cytometry is an inappropriate method for sperm counting, especially in the case of azoospermia.

First Report of Alternaria tenuissima Causing Disease on Blueberry in China.

During September 2006, disease symptoms were observed on mature highbush blueberry (Vaccinium corymbosum L.) cvs. Bluecrop and Covoille in a blueberry commercial field in Dalian, China. The maximum and minimum rainfalls in June to September are 3,111.9 and 1,745.6 ml, respectively. The highest temperature during the summer is 35.3°C and relative humidity may achieve 90%. Circular to irregular, light brown-to-gray leaf spots with brownish red borders, initially 3 to 7 mm in diameter, enlarged and coalesced. Reddish, circular spots appeared on stems, developing small, insignificant cankers. A fungus was recovered on potato dextrose agar (PDA, pH nature) from the margin of necrotic leaf spots. Morphological traits of the strain that developed from a single-spore culture were as follows: colonies were regular and flat, with a rough upper surface that peripherally was olive-green with a black center and dull white spots; short conidiophores arising singly and measuring 81.6 to 163.2 × 4.1 to 8.2 µm; conidia was abundant, ovoid, and obclavate muriformly septate, which horizontal and vertical septations varied from 1 to 6 and 0 to 2, respectively, and its size varied from 26 to 48.8 × 9.7 to 16.3 µm with an average beak length of 9.6 µm, and sporulation pattern is budding. Conidia derived from conidiophores. Koch's postulates were fulfilled for the isolates by spray inoculating two healthy mature plants with 2 × 105 conidia per ml homogenized in sterile water. As a control, two plants were sprayed with sterile water. Plants were placed inside plastic bags to maintain humidity and incubated in a growth chamber at 26°C under fluorescent light for 14 h and 20°C in darkness for 10 h. After 2 days, the plastic bags were removed and plants were maintained under the same conditions for 30 days. Symptoms on inoculated plants were similar to those previously observed. Symptoms were not observed on control plants. Cultures isolated from inoculated plants had the same morphological traits as those that were isolated previously from the field plants. The morphological descriptions and measurements were similar to Alternaria tenuissima (2). The 5.8S subunit and flanking internal transcribed spacers (ITS1 and ITS2) of rDNA and partial cds histone gene were amplified from DNA extracted from single-spore cultures using the ITS1/ITS4 and H3-1a/H3-1b primers, respectively, and sequenced (GenBank Accession No. EF031053) (1,3). The ITS sequence was identical to the ITS regions of A. tenuissima strain EGS34-015 (100%; GenBank Accession No. AY751455), the partial cds histone gene sequence was similar to A. tenuissima isolate MA6 (99%; GenBank Accession No. AF404634). The morphology, secondary conidiation, and sequences of ITS and partial cds histone gene identify the causal fungus as A. tenuissima. To our knowledge, this is the first report on the presence of A. tenuissima affecting blueberry plants in China. References: (1) J. C. Kang et al. Mycol. Res. 106:1151, 2002. (2) E. G. Simmons. Mycotaxon 70:325, 1999. (3) T. J. White et al. Pages 315-322 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

Glial cell line-derived neurotrophic factor protects against ischemia/hypoxia-induced brain injury in neonatal rat.

Ischemic/hypoxic brain damage induced in 7-day-old rats was significantly attenuated in a dose-dependent manner by intracerebral injection of glial cell line-derived neurotrophic factor (GDNF; 2 or 4 microg) within 30 min after the insult. Whereas the great majority of the vehicle-treated animals showed massive infarction involving more than 75% of the affected cerebral hemisphere, GDNF injection resulted in a remarkable reduction in both the incidence and severity of the brain damage (incidence ranging from 76% to 93% in controls to 34% to 64% in the 2.0-microg group and 7% to 29% in 4.0-microg group). The induction of immunoreactive 70-kDa heat shock protein (HSP70) in cerebral cortical neurons was also significantly reduced in GDNF-treated animals as compared to controls. The mechanisms responsible for the neuroprotective effects of GDNF remain unknown, although it has been speculated that these may be endogeneous. The higher expression of GDNF and its mRNA in developing brains may be one of the factors responsible for the relative resistance to ischemia of fetal and neonatal as opposed to adult brains. GDNF may possibly act by protecting against oxidative stress or by scavenging free radicals generated during ischemia. The results of our study strongly suggest that GDNF may prove to be an effective and potent protective agent against perinatal ischemic/hypoxic encephalopathy.

Hypoxic-ischemic tolerance induced by hyperthermic pretreatment in newborn rats.

OBJECTIVE: We investigated the effect of hyperthermic pretreatment 24 hours before hypoxic-ischemic exposure on neuronal cell damage in 7-day-old rats. METHODS: Newborn rats were separated on postnatal day 7 into two groups: 1) preheated (those exposed to 2 hours of hyperthermic pretreatment at 42-43C) (n = 29), and 2) nonheated (n = 20). At 24 hours after the hyperthermic stress, rats from both groups were subjected to left carotid artery ligation followed by 2 hours of hypoxia (8% oxygen/92% nitrogen) at 33C. All rats were killed 1 week after hypoxia-ischemia, and brains were extracted for histologic study. A different group of 7-day-old rats (n = 8) was placed in the same hyperthermic environment as mentioned above for 2 hours, and 24 hours after heat exposure brains were extracted for immunohistochemistry of heat-shock protein 70. RESULTS: The total incidence of hypoxic-ischemic brain damage significantly decreased in the preheated group (12 of 25 [48%]) compared with the nonheated group (17 of 20 [85%]; P < .03). The induction of immunoreactive heat-shock protein 70 was observed mainly in glial and vascular endothelial cells and, in a lesser amount, in neuronal cells of the cerebral cortex and hippocampus. CONCLUSION: Incidence of hypoxic-ischemic brain damage is consistently reduced by 2 hours of hyperthermic pretreatment in 7-day-old rats.

Important role of 72-kd heat shock protein expression in the endothelial cell in acquisition of hypoxic-ischemic tolerance in the immature rat.

OBJECTIVES: Hypoxic-ischemic tolerance can be induced in neonatal rats through hyperthermic preconditioning. The purposes of this study were to determine the interval between hyperthermic preconditioning and a subsequent hypoxic-ischemic insult that would provide optimal neuroprotection against the insult and to examine the relationship between tolerance induction and heat shock protein expression. STUDY DESIGN: On postnatal day 7 Wistar rat pups were separated into the following 2 groups: a heated group (those exposed to 15 minutes of hyperthermic pretreatment at a brain temperature of 41.5 degrees C-42.0 degrees C) and an unheated control group. At 6, 12, 24, 48, and 72 hours after the hyperthermic stress, rats from both groups were exposed to left carotid artery ligation followed by 2 hours of hypoxia (8% oxygen and 92% nitrogen) at 33 degrees C. Twenty animals from each group were used at each time point. All rats were killed at 1 week after hypoxia-ischemia, at which time the brains were processed and neuronal damage in the cortex and hippocampus was assessed histologically. Another set of 7-day-old rats (n = 30) was studied immunohistochemically at 6, 12, 24, 48, and 72 hours after the same hyperthermic treatment. Expression of 72-kd heat shock protein was measured in neuronal, glial, and vascular endothelial cells. RESULTS: Hyperthermia-induced hypoxic-ischemic tolerance was observed at 6, 12, and 24 hours but not at 48 and 72 hours after hyperthermic preconditioning. Heat shock protein 72 expression in the vascular endothelial cells, rather than in the glial or neuronal cells, was most strongly associated with hypoxic-ischemic tolerance. CONCLUSION: These findings suggest that heat shock protein 72 in endothelial cells plays an important role in the acquisition of hypoxic-ischemic tolerance at postnatal day 7, a time when maximal angiogenesis occurs and the blood-brain barrier is still immature.

Differential neurotrophin levels in cerebrospinal fluid and their changes during development in newborn rat.

Cerebrospinal fluid concentration of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) was measured in normal developing rat from birth to postnatal day (PND) 21 by enzyme-linked immunosorbent assay. NGF levels were significantly higher than those of BDNF and NT-3 from PND 1-21. NGF levels decreased from PND 1-3 to PND 9. At PND 15 and 17, NGF levels peaked a second time and rapidly decreased to PND 21. BDNF peaked at PND 13-15, while NT-3 levels peaked at PND 7-9. Each of the three neurotrophins has its own characteristic pattern in changes in cerebrospinal fluid levels.

Expression of glial cell line-derived neurotrophic factor in the brain and cerebrospinal fluid of the developing rat.

Expression of GDNF in developing rat brain from PND 1 to 14 and on PND 21 was examined immunocytochemically. At PND 1, intense diffuse immunoreactivity was noted within the cytoplasm of a diverse group of neuronal and nonneuronal cells, including choroid plexus epithelial cells, ependymal cells, tanycytes of the third ventricle, and cellular elements in the subarachnoid compartment. GDNF expression became more localized among these cells from PND 7-14 and was almost undetectable by PND 21. Although GDNF-positive small glial cells were scattered within the cerebral cortical plate and the striatum already at PND 1, GDNF expression among astroglial cells within the corpus callosum and in the white matter adjacent to the lateral ventricles was more prominent between PND 5 and 8. GDNF expression among the pyramidal neurons of the cerebral cortex was evident relatively early in the postnatal period, but the neurons of the hippocampus and thalamus showed more intense immunoreactivity at later periods between PND 8-14. ELISA of the CSF revealed a rapid rise in GDNF levels from 71.4 +/- 10.9 pg/ml (mean +/- S.E.M.) at PND 1 to peak levels of 138.4 +/- 18.5, 135.1 +/- 5.4 and 132.9 +/- 8.0 pg/ml, at PND 5, 7 and 9, respectively. Peak CSF levels of GDNF occurred when GDNF expression was intense within astroglial cells in the corpus callosum and cerebral white matter. Thereafter, the levels gradually decreased to 76.5 +/- 9.7 pg/ml at PND 21. The widespread expression of GDNF among different cellular elements in the developing brain suggest that GDNF probably plays diverse functional roles in many different neuronal systems in addition to its known effects on the dopaminergic system. Developmental shifts in GDNF expression further suggest that GDNF may be of critical importance at different stages of brain growth and differentiation.