[Effectiveness analysis of hybrid endoscopic submucosal dissection in patients with colorectal epithelium-derived tumors]

Objective: To compare the clinical benefits of classic endoscopic submucosal dissection (ESD) and hybrid ESD for the treatment of colorectal epithelium-derived tumors. Methods: The current investigation was a retrospective multicenter study of 418 patients who underwent ESD between January 2015 and April 2021 at Beijing Jishuitan Hospital. The patients were assigned to one of two groups based on the surgical procedure they underwent; a classic ESD group or a hybrid ESD group. The primary outcome was the rate of en bloc resection and complete resection. SPSS 26.0 was used for statistical analysis. Homogeneity of variance was assessed via Cochran's test. Normally distributed data with homogeneity of variance were analyzed via the t-test for independent samples. Non-normally distributed data and data with unequal variance were analyzed via the Kruskal-Wallis non-parametric test. Categorical data were analyzed via the Chi-square test or Fisher's exact test. Multivariable assessment was performed via logistic regression analysis. Results: The en bloc resection rates [89.4% (84/94) vs. 87.0% (194/223), χ2=0.34, P=0.558] and complete resection rates [85.1% (80/94) vs. 82.1% (183/223), χ2=0.33, P=0.510] were similar. Compared with classic ESD, procedures were shorter in the hybrid ESD group [22(7, 213) vs. 47(12, 680) min, Z=0.23, P<0.001], dissection was completed more rapidly [0.14(0.02, 0.32) vs. 0.10(0.02, 0.41) cm2/min, Z=0.08, P<0.001], and there was a higher rate of perforation (9.6% vs. 2.2%, χ2=2.67, P=0.006). Laterally spreading tumor granular type nodular mixed, non-granular type pseudo-depressed, flat-elevated type (odds ratio 2.826, P=0.012), and tumor location (odds ratio 6.970, P=0.005) were independently associated with complete resection in the hybrid ESD group. Conclusion: Classic ESD and hybrid ESD had similar en bloc and complete resection rates for colorectal epithelium-derived tumors, but hybrid ESD had shorter operation times. With respect to hybrid ESD, factors associated with failure of complete resection included lesion type and crossing tissue boundaries.

Recent advances in lipid nanovesicles for targeted treatment of spinal cord injury

The effective regeneration and functional restoration of damaged spinal cord tissue have been a long-standing concern in regenerative medicine. Treatment of spinal cord injury (SCI) is challenging due to the obstruction of the blood-spinal cord barrier (BSCB), the lack of targeting of drugs, and the complex pathophysiology of injury sites. Lipid nanovesicles, including cell-derived nanovesicles and synthetic lipid nanovesicles, are highly biocompatible and can penetrate BSCB, and are therefore effective delivery systems for targeted treatment of SCI. We summarize the progress of lipid nanovesicles for the targeted treatment of SCI, discuss their advantages and challenges, and provide a perspective on the application of lipid nanovesicles for SCI treatment. Although most of the lipid nanovesicle-based therapy of SCI is still in preclinical studies, this low immunogenicity, low toxicity, and highly engineerable nanovesicles will hold great promise for future spinal cord injury treatments.

Effects of grain type and conditioning temperature during pelleting on growth performance, ruminal fermentation, meat quality and blood metabolites of fattening lambs

Ruminants can tolerate moderate concentrations of dietary tannin, making it feasible to replace corn with sorghum in ruminant diets; however, conditioning temperature of pelleted total mixed ration (PTMR) greatly affects nutrient digestibility. The objective was to determine effects of grain type and conditioning temperature during pelleting on growth performance, ruminal fermentation, meat quality and blood metabolites of fattening lambs. This was a 2 × 3 factorial study, with corn and sorghum and three conditioning temperatures (65, 75 and 85 °C) in a randomized complete design, with 36 lambs (120 ± 10.2 d and 24.9 ± 3.3 kg) grouped by weight and randomly allocated. The resulting six PTMRs were referred to as 65-S, 75-S and 85-S for sorghum-based diets, and 65-C, 75-C and 85-C for corn-based diets, for low, medium and high pelleting temperatures, respectively. There was no grain type × conditioning temperature (Grain × Temp) interaction on growth performance and apparent nutrient digestibility. Furthermore, grain type did not affect DM intake (DMI), average daily gain (ADG) or feed conversion ratio (FCR) of fattening lambs. Pelleting at 75 °C improved ADG (P < 0.03) and FCR (P < 0.02) of fattening lambs compared to other temperatures. There was a Grain × Temp interaction (P < 0.01) on ruminal pH (lowest in lambs fed 75-S). There tended (P = 0.07) to be a Grain × Temp interaction for total volatile fatty acid (VFA), and there were Grain × Temp interactions for molar proportions of acetate (P < 0.04), butyrate (P < 0.03) and branch-chained VFA (P < 0.01). Lambs fed sorghum-based PTMR had greater molar proportion of propionate (P < 0.03) and lower acetate to propionate ratio (A:P, P < 0.04). Lambs fed sorghum-based PTMR had higher plasma concentrations of urea nitrogen (N) (P < 0.03), glucose (P < 0.01) and alkaline phosphatase (P < 0.05), whereas other blood metabolites were not affected by treatments. There were Grain × Temp (P < 0.03) interactions for color coordinates of longissimus and mid-gluteal muscle. Lambs fed sorghum-based PTMR had lower (P < 0.01) dressing percentage and meat quality than those fed corn-based PTMR. We concluded that sorghum can replace corn in lamb diets without compromising growth performance and feed efficiency; furthermore, feeding sorghum vs corn improved rumen fermentation, with reduced A:P ratio and enhanced N and glucose utilization. Finally, pelleting at 75 °C increased feeding value of either sorghum- or corn-based PTMR for fattening lambs.

A direct-write method for preparing a bimetal sulfide/graphene composite as a free-standing electrode for high-performance microsupercapacitors

It is a great challenge to ideally integrate graphene with its unique two-dimensional (2D) and porous structure into the pseudocapacitive materials. In this paper, a simple technique, i.e. direct-laser-writing (DLW), was developed to fabricate microsupercapacitors (MSCs) with excellent electrochemical performance, marked as Ni–Co–S/laser induced graphene (LIG) that exhibit a high areal specific capacitance of 680 mF cm⁻² at the current density of 1 mA cm⁻². A symmetric MSC device was assembled using Ni–Co–S/LIG as a positive electrode and active carbon (AC) as the negative electrode, and exhibited a high areal energy density of 56.9 μW h cm⁻² at the power density of 800 μW cm⁻², and excellent cycling stability maintaining 89.6% of the areal specific capacitance after 8000 cycles. The synergistic effect of bimetallic Ni–Co–S and the LIG with the 2D structure results in the excellent electrochemical performance. This work demonstrates a method to integrate Ni–Co–S pseudocapacitive materials into porous graphene with a direct-laser-writing technique. The produced integrated materials possess high energy density that can be used in MSCs.

This work demonstrates a method to integrate Ni–Co–S pseudocapacitive materials into the porous graphene producing from direct-laser-writing technique.

[Effect of anatomical changes of frontal recess and frontal sinus on airflow after nasalisation by image reconstruction and numerical simulation]

Objective: To describe the influence of post-operative anatomical structure changes on nasal airflow characteristics by 3D reconstruction and numerical simulation in real cases after nasalisation with Draf Ⅲ so as to explore the correlation between the changes of anatomical structure and subjective symptoms as well as airflow characteristics. Methods: Ten patients underwent nasalization with Draf Ⅲ in Department of Rhinology in Beijing Tongren Hospital from 2006 to 2018 were selected retrospectively. Postoperative follow-up of all patients was more than 1 year. All patients had no abnormalities in their paranasal sinus CT scans and Lund-Kennedy scores were 0 except scar. VAS scores including nasal obstruction, stimulation in frontal sinus, and headache were collected at the same period. The control model was a normal person. Numerical simulation was used for calculating airflow characteristics in deep inspiratory period of both models. Independent sample Mann-Whitney U test and Spearman correlation test were used by software SPSS 22.0. Results: The airflow pressure in frontal sinus ostium was (7.21±1.39)×10(4) Pa (Mean±SD), which was lower than that in normal subjects (8.99×10(4) Pa) under deep inspiratory simulation. But, the velocities in frontal sinus ostium and frontal sinus were (40.10±2.46) m/s and (28.19±1.73) m/s respectively, which were higher than those in normal one (2.70 m/s, 0.73 m/s). The airflow patterns of the two models were basically similar. There was no significant difference in the opening size and volume of frontal sinus between different groups after grouped by three symptoms respectively. No correlation could be found between the opening size and volume of the frontal sinus with the appearance and severity of three subjective symptoms. Conclusions: The airflow pattern and distribution after nasalisation with Draf Ⅲ are like those of normal person. There is no correlation between the changes of anatomy in frontal recess and frontal sinus and nasal airflow characteristics as well as subjective symptoms.

Neuroprotective effects of ganoderma lucidum polysaccharides against oxidative stress-induced neuronal apoptosis

Ganoderma lucidum polysaccharides have protective effects against apoptosis in neurons exposed to ischemia/reperfusion injury, but the mechanisms are unclear. The goal of this study was to investigate the underlying mechanisms of the effects of ganoderma lucidum polysaccharides against oxidative stress-induced neuronal apoptosis. Hydrogen peroxide (H₂O₂) was used to induce apoptosis in cultured cerebellar granule cells. In these cells, ganoderma lucidum polysaccharides remarkably suppressed H₂O₂-induced apoptosis, decreased expression of caspase-3, Bax and Bim and increased that of Bcl-2. These findings suggested that ganoderma lucidum polysaccharides regulate expression of apoptosis-associated proteins, inhibit oxidative stress-induced neuronal apoptosis and, therefore, have significant neuroprotective effects.

{2-[(2-Amino-cyclo-hex-yl)imino-meth-yl]phenolato}dioxidovanadium(V)

In the title dioxidovanadium complex, [V(C(13)H(17)N(2)O)O(2)], the V(V) atom is in a square-based pyramidal coordination: the basal plane is defined by the phenolate O, imine N and amine N atoms of the tridentate Schiff base ligand, and by one oxide O atom. The apical position is occupied by the other oxide O atom. In the crystal, mol-ecules are connected by N-H⋯O and N-H⋯(O,O) hydrogen bonds, forming a tetra-mer.

Diagnosis and treatment of ossification of the ligamentum flavum associated with dural ossification

Object

In this paper, the authors aimed to summarize the clinical characteristics of ossification of the ligamentum flavum (OLF) associated with dural ossification (DO) and to identify improved methods for preoperative diagnosis.

Methods

Thirty-six patients who had undergone OLF surgery between February 2005 and September 2009 were included in this retrospective study. The patients were divided into 2 groups: one that included patients with intraoperative evidence of DO and a second group that included patients without DO. The clinical features of DO were summarized and the neurological status of the patients was evaluated pre- and postoperatively.

Results

The incidence rate of DO associated with OLF was 39% (14/36). The sensitivity and specificity of the tram track sign were found to be 93% and 59%, respectively. Dural ossification was found among 86% of the patients with tuberous type Sato classification. The postoperative neurological status of patients was generally improved relative to that observed prior to surgery, although neurological recovery did not differ between the 2 groups. Cerebrospinal fluid leakage was the main complication, occurring predominantly in the patients with DO, and all leaks resolved in all patients after comprehensive treatments.

Conclusions

The tram track sign and Sato classification were found to be useful for preoperative diagnosis of DO and for determining the surgical procedure to be performed. Dural ossification had no effect on postoperative neurological recovery.

Degradation of forage chicory by ruminal fibrolytic bacteria

AIMS

Determine the susceptibility of forage chicory (Cichorium intybus L.) to degradation by ruminal fibrolytic bacteria and measure the effects on cell-wall pectic polysaccharides.

METHODS AND RESULTS

Large segments of fresh forage chicory were degraded in vitro by Lachnospira multiparus and Fibrobacter succinogenes, but not by Ruminococcus flavefaciens or Butyrivibrio hungatei. Cell-wall pectins were degraded extensively (95%) and rapidly by L. multiparus with a simultaneous release of uronic acids and the pectin-derived neutral monosaccharides arabinose, galactose and rhamnose. Fibrobacter succinogenes also degraded cell-wall pectins extensively, but at a slower rate than L. multiparus. Immunofluorescence microscopy using monoclonal antibodies revealed that, after incubation, homogalacturonans with both low and high degrees of methyl esterification were almost completely lost from walls of all cell types and from the middle lamella between cells.

CONCLUSIONS

Only two of the four ruminal bacteria with pectinolytic activity degraded fresh chicory leaves, and each showed a different pattern of pectin breakdown. Degradation was greatest for F. succinogenes which also had cellulolytic activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

The finding of extensive removal of pectic polysaccharides from the middle lamella and the consequent decrease in particle size may explain the decreased rumination and the increased intake observed in ruminants grazing forage chicory.

Body and brain development following exposure to 60Co gamma-irradiation during pregnancy in mice

We studied the dose-response effects of gamma-irradiation on the weight gains of the body and the brain in ICR mice exposed to various doses of 60Co gamma-irradiation ranging from 0 to 1.5 Gy on day 13 of pregnancy (El3). We found that 0.5 Gy gamma-irradiation caused a significant reduction in brain weight but not in body weight among 6-week-old mice. Higher doses (1.0, 1.5 Gy) seriously inhibited body and brain development, resulting in significantly low weights at 6 weeks of age. A significantly lower brain weight among fetuses exposed to 1.5 Gy was found as early as 24 hours after exposure, while significant reductions in the body weight of these same fetuses appeared 3 days after exposure. The effects of radiation on brain and body development were similar for both males and females.

Neurogenesis of heterotopic gray matter in the brain of the microcephalic mouse

Neurogenesis of heterotopic gray matter in the brain of the microcephalic mouse prenatally exposed to X-rays at embryonic day 13 (E13) was studied immunohistochemically. Bromodeoxyuridine (BrdU) as a marker to label the migrating position of neuroblasts generated at various embryonic stages showed that no "inside-out" pattern of neuronal migration occurred in the heterotopic cell mass similar to that seen in the laminated cortex. Further results in which midkind (MK) immunoreactive radial glial fibers did not appear in the heterotopic cell mass demonstrated that heterotopia formed in the absence of radial glia system. Different types of cells (pyramidal and non-pyramidal neurons) in the heterotopic cell mass were identified with immunoreactivity for anti-parvalbumin and anti-calbindin D-28K antibodies in addition to current histological methods. Two major types of neurons were mixed together with random distribution in the heterotopic cell mass. This finding indicates that irradiation might have no selective effects on the precursors of pyramidal and non-pyramidal neurons. Moreover, anti-glial fibrillary acidic protein (GFAP) immunostaining showed that numerous astrocytes were present in the heterotopic cell mass. The fact that astrocytes appeared in the heterotopia without the transition from classic radial glial cells to astrocytes suggests that astrocytes might be generated directly from a separate astroglial precursor.

Purkinje cell degeneration in mice lacking the xeroderma pigmentosum group G gene

Laboratory mice carrying the nonfunctional xeroderma pigmentosum group G gene (the mouse counterpart of the human XPG gene) alleles have been generated by using gene-targeting and embryonic stem cell technology. Homozygote animals of this autosomal recessive disease exhibited signs and symptoms, such as postnatal growth retardation, reduced levels of activity, progressive ataxia and premature death, similar to the clinical manifestations of Cockayne syndrome (CS). Histological analysis of the cerebellum revealed multiple pyknotic cells in the Purkinje cell layer of the xpg homozygotes, which had atrophic cell bodies and shrunken nuclei. Further examination by an immunohistochemistry for calbindin-D 28k (CaBP) showed that a large number of immunoreactive Purkinje cells were atrophic and their dendritic trees were smaller and shorter than in wild-type littermates. These results indicated a marked degeneration of Purkinje cells in the xpg mutant cerebellum. Study by in situ detection of DNA fragmentation in the cerebellar cortex demonstrated that some deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin in situ nick labeling (TUNEL)-positive cells appeared in the granule layer of the mutant mice, but few cell deaths were confirmed in the Purkinje layer. These results suggested Purkinje cell degeneration in the mutant cerebellum was underway, in which much Purkinje cell death had not appeared, and the appearance of some abnormal cerebellar symptoms in the xpg-deficient mice was not only due to a marked Purkinje cell degeneration, but also to damage of other cells.

Effects of the restriction of food and water intake on the distribution and retention of radioiodine in mice

The effects of the restriction of food and water intakes on gastrointestinal absorption, distribution to organs and excretion of 131I were investigated in C3H/He mice. The animals were divided into four groups and administered orally 37 kBq carrier-free Na 131I in 0.25 ml normal saline. One group of animals was given food and water ad libitum throughout the experimental period. Food and water to the remaining groups were restricted before and/or after the administration of 131I. The animals in each group were sacrificed 4 h and 24 h after administration, and the activity of 131I in thyroid, blood, liver, kidney, gastrointestinal tract, urine, feces, and carcass was measured. There was a significant increase in the retention of 131I in the thyroid and the concentration of 131I in the blood due to the restriction of food and water after the administration of 131I. In contrast, a significant decrease in the urinary excretion was observed in these animals. In those animals, which fasted before administration only, the retention of 131I in the thyroid and other organs were decreased. Therefore, for an accurate diagnosis and effective therapy with radioiodine as well as effective radiation protection, the intake of food and water should be taken into account.

Determination of the spatial distribution of major elements in the rat brain with X-ray fluorescence analysis

An energy dispersive X-ray fluorescence analysis was applied for determining the spatial (two-dimensional) distribution of elemental concentrations in rat brain sections. Freeze-dried brain sections prepared from normal and ischemic rats with middle cerebral artery occlusion were scanned with a collimated X-ray beam (0.18 mm in diameter, 50-kV acceleration voltage). The fluorescent Kalpha X-rays of P, S, Cl, and K were detectable, so that the two-dimensional distribution of fluorescent X-ray intensities could be determined for these elements. Furthermore, quantitative determination was possible for P and K by using the fundamental parameter technique. However, the accurate determination of Na and Ca was difficult, because of the low energy of Kalpha X-ray of Na, and the interference of K-Kbeta with Ca-Kalpha. The change in elemental concentrations in ischemic tissue, including the decrease in K concentration and increase in Cl concentration, was demonstrated by this method as a two-dimensional contour map. Since it is possible to obtain a pictorial representation of the elemental concentration in tissue sections, this method may be useful to evaluate the ionic changes in injured brain tissue in relation to histological or autoradiographical observations.

Radiation-induced tissue abnormalities in fetal brain are related to apoptosis immediately after irradiation

PURPOSE

To investigate the relation between the incidence of radiation-induced tissue abnormalities in fetal brain and the extent of p53-dependent apoptosis.

MATERIALS AND METHODS

Pregnant mice with wild-type p53(+/+), heterozygous p53(+/-) and homozygous mutant p53(-/-) fetuses received whole-body X-irradiation on day 13 of gestation. The extent of apoptosis 6 hr after irradiation and the incidence of tissue abnormalities 3 days after irradiation in the brain were evaluated by histological examination of brain mantle.

RESULTS

The percentage of apoptotic cells increased linearly with dose in p53(+/+) and p53(+/-) fetuses, but no increase was found in p53(-/-). Approximately twice the dose was necessary in p53(+/-) fetuses to induce an apoptotic response to the extent observed in p53(+/+). Fetuses with brain-tissue abnormalities, such as a destroyed ventricular lining and rosettes with a central hollow appeared at a dose of 1.5 and 3.0 Gy, and the incidence was markedly increased following a dose of 2.25 and 3.75Gy in p53(+/+) and p53(+/-) mice, respectively, but no fetus with tissue abnormalities appeared in p53(-/-) at up to 3.75 Gy. Approximately twice the dose was necessary in p53(+/-) fetuses to induce brain-tissue abnormalities to the extent seen in p53(+/+) mice.

CONCLUSION

The extent of apoptosis 6 hr after irradiation and the incidence and severity of brain-tissue abnormalities 3 days after irradiation corresponded well, suggesting that radiation-induced tissue abnormalities, such as destroyed ventricular lining, deranged glial fibre and appearance of rosettes in fetal brain were closely related to apoptosis seen 6 hr after irradiation.

Abnormal expression of tyrosine hydroxylase immunoreactivity in cerebellar cortex of ataxic mutant mice

Expression of tyrosine hydroxylase (TH) was examined immunohistochemically in the cerebellum of two ataxic mutants, Rolling mouse Nagoya (RMN) and dilute-lethal mice (DL). In littermate controls of both mutants, a few TH-positive Purkinje cells were distributed sparsely and their number was smaller than in the mutants at any ages examined. In RMN, TH-positive Purkinje cells were distributed in lobule IX and X, and were arranged into parasagittal bands at 2 weeks of age. TH-positive Purkinje cells increased in number and were widely distributed throughout the vermis at 3 weeks of age. In adult RMN, TH-positive Purkinje cells were found in all lobules of the cerebellum. Their parasagittal bands also became evident in the hemisphere. In DL, TH-positive Purkinje cells were mainly distributed in vermal lobules IX and X, and the flocculus at 3 weeks of age. They were also found as bands in lobules IX and X. The results suggest that abnormal expression of TH in Purkinje cells may not be specific to the allelic group. Since TH promoter is activated by Ca2+, TH expression in the mutant Purkinje cells may predict neuronal dysfunction caused by alterations in cellular Ca2+ currents.

Induction of aromatase expression by aminoglutethimide, an aromatase inhibitor that is used to treat breast cancer in postmenopausal women

Aromatase, a cytochrome P450, catalyzes three consecutive hydroxylation reactions converting C19 androgens to aromatic C18 estrogenic steroids. Aminoglutethimide (AG) is an aromatase inhibitor used to treat estrogen-dependent breast cancer. While AG is effective in inhibiting aromatase, it was found that aromatase activity in tumors of some breast cancer patients elevated after AG treatment (Miller and O'Neill, Steroids, 50: 245-252, 1987). These results may explain why some patients failed therapy after extensive AG treatment. Recently, we found that AG treatment increased aromatase activity in SK-BR-3, JAR, and HepG2 cell lines in a dose- and incubation time-dependent manner. AG induction is thought to occur at the transcriptional level because the aromatase mRNA level elevated after AG treatment in SK-BR-3 and HepG2 cells, as demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) analysis, and AG treatment did not increase aromatase activity in aromatase cDNA transfected cell lines (driven by the beta-actin promoter). Our primer-specific RT-PCR analysis revealed that in SK-BR-3 cells, AG enhanced the action of a promoter which is different from promoter I.1, I.3, or II. Furthermore, since the AG induction was found to be suppressed by SQ 22536, an adenylate cyclase inhibitor, a cAMP-dependent mechanism might be involved. Our study provides an insight as to why some patients fail therapy after extensive AG treatment.

Different patterns of abnormal neuronal migration in the cerebral cortex of mice prenatally exposed to irradiation

A characteristic abnormal cortical architecture in the adult brain was produced in mice subjected to 1.5 Gy of X-irradiation on embryonic day 14. Neurons in the lateral regions were organized into an essentially six-layered structure, while neurons in the dorsal regions formed a unique four-layered cortex. The patterns of neuronal migration in these different cortical regions were examined with immunohistochemistry for anti-bromodeoxyuridine (BrdU), anti-midkine (MK), and anti-glial fibrillary acidic protein (GFAP) antibodies. In the cortical lateral region, BrdU-labeled cells in the upper layers were fewer, and those in lower layers more numerous in prenatally irradiated mice than in control, while in the dorsal region (four-layered region), BrdU-labeled cells were very few in layer 2, and a large number of labeled-cells remained in layer 4. These results indicated that some neuroblasts in the lateral cortical region could not migrate to the upper layers, and that most neuroblasts in the dorsal cortical region failed to pass through the earlier migration zone. MK- and GFAP-stained radial glial fibers showed that the radial fibers were consistently oriented in the direction of neuronal migration in the control brains. However, in the irradiated brain, such radial fibers were crumpled in the lateral region, or were reduced markedly in number in some parts of the dorsal region. These results revealed that neuronal migratory pathways (radial glial fibers) were destroyed differently in different regions, and that X-rays killed some cells including radial glial cells or their precursors during the embryonic stage. These effects of radiation on the developing brain may result from the possibility that neurogenetic time is different or there are cellular mechanisms involved in the radiosensitivity among different regions.

Abnormal distribution of hippocampal mossy fibers in rats exposed to X-irradiation in utero

The effects of prenatal X-irradiation (0.3, 0.6, 1.2 or 1.8 Gy) on the hippocampal development were examined at six weeks of age in rats. The laminar structure of the hippocampus was deranged in the rats exposed to 0.6 Gy or more. Pyramidal cells in the CA-3 region were more susceptible than those in the CA-1 region. Aberrant mossy fiber terminals were observed in the stratum oriens of the CA-3 region (infrapyramidal mossy fibers) in rats exposed to 0.3 Gy or more.

An immunohistochemical study of radial glial cells in the mouse brain prenatally exposed to gamma-irradiation

The features of a glial cell population in the developing brain of mice prenatally exposed to 60Co gamma-irradiation at the most radiosensitive stage were studied with immunohistochemistry for anti-midkine (MK), anti-vimentin (Vim), and anti-GFAP antibodies. Anti-MK- and anti-Vim-positive radial glial fibers distributed in a similar radial fashion; these fibers were observed primarily in the embryonic period and disappeared after birth. Anti-MK- and anti-Vim-stained radial fibers ran perpendicular to the pial surface in controls, whereas such fibers were disorganized 6 hours (h) after irradiation. This finding provided new evidence that the migratory pathways of young neurons were interrupted beginning a few hours after irradiation. By E17 the ectopic cell masses formed so as to replace the parts of the ventricular zone where no anti-MK immunoreactive radial fibers were present, but where anti-GFAP-stained fibrillary astrocytes emerged in the ectopic cell masses from the early postnatal period. The results suggested a twofold source of the generated astrocytes: either directly from a separate precursor of the astrocytes, or due to the transformation of the classic radial glial cells. In the newborn, numerous protoplasmic transitional forms displaced by astrocytes in irradiated brains indicated that reactive gliosis was a powerful response of a brain exposed to irradiation.

Catalytic properties of NAD(P)H:quinone oxidoreductase-2 (NQO2), a dihydronicotinamide riboside dependent oxidoreductase

Human NAD(P)H:quinone acceptor oxidoreductase-2 (NQO2) has been prepared using an Escherichia coli expression method. NQO2 is thought to be an isoform of DT-diaphorase (EC 1.6.99.2) [also referred to as NAD(P)H:quinone acceptor oxidoreductase] because there is a 49% identity between their amino acid sequences. The present investigation has revealed that like DT-diaphorase, NQO2 is a dimer enzyme with one FAD prosthetic group per subunit. Interestingly, NQO2 uses dihydronicotinamide riboside (NRH) rather than NAD(P)H as an electron donor. It catalyzes a two-electron reduction of quinones and oxidation-reduction dyes. One-electron acceptors, such as potassium ferricyanide, cannot be reduced by NQO2. This enzyme also catalyzes a four-electron reduction, using methyl red as the electron acceptor. The NRH-methyl red reductase activity of NQO2 is 11 times the NADH-methyl red reductase activity of DT-diaphorase. In addition, through a four-electron reduction reaction, NQO2 can catalyze nitroreduction of cytotoxic compound CB 1954 [5-(aziridin-1-yl)-2,4-dinitrobenzamide]. NQO2 is 3000 times more effective than DT-diaphorase in the reduction of CB 1954. Therefore, NQO2 is a NRH-dependent oxidoreductase which catalyzes two- and four-electron reduction reactions. NQO2 is resistant to typical inhibitors of DT-diaphorase, such as dicumarol, Cibacron blue, and phenindone. Flavones are inhibitors of NQO2. However, structural requirements of flavones for the inhibition of NQO2 are different from those for DT-diaphorase. The most potent flavone inhibitor tested so far is quercetin (3,5,7,3',4'-. 6pentahydroxyflavone). It has been found that quercetin is a competitive inhibitor with respect to NRH (Ki = 21 nM). NQO2 is 43 amino acids shorter than DT-diaphorase, and it has been suggested that the carboxyl terminus of DT-diaphorase plays a role in substrate binding (S. Chen et al., Protein Sci. 3, 51-57, 1994). In order to understand better the basis of catalytic differences between NQO2 and DT-diaphorase, a human NQO2 with 43 amino acids from the carboxyl terminus of human DT-diaphorase (i.e., hNQO2-hDT43) has been prepared. hNQO2-hDT43 still uses NRH as an electron donor. In addition, the chimeric enzyme is inhibited by quercetin but not dicumarol. These results suggest that additional region(s) in these enzymes is involved in differentiating NRH from NAD(P)H.

Autocrine and paracrine actions of breast tumor aromatase. A three-dimensional cell culture study involving aromatase transfected MCF-7 and T-47D cells

Stable aromatase-expressing MCF-7 and T-47D cell lines (i.e. MCF-7aro and T-47Daro) have been prepared by aromatase cDNA transfection and G418 (neomycin) selection. MCF-7aro was further subjected to a clonal purification. Aromatase activity in the transfected MCF-7 and T-47D cell lines was determined to be 73 +/- 6 pmol/mg/h and 48 +/- 4 pmol/mg/h, respectively. It is thought that these cell lines express aromatase in a stable manner, as demonstrated by a steady expression of the enzyme during culture in the absence of G418. The growth of these cells could be stimulated by androgens (1-10 nM) as demonstrated through a spheroid culture method. The androgen-stimulated growth could be suppressed by 4-hydroxyandrostenedione (4-OHA) (0.01-0.1 mM) or tamoxifen (50 nM-1 microM). In order to test the hypothesis that tumor aromatase can affect breast tumor growth in a paracrine manner, we have carried out cell culture experiments by co-culturing MCF-7 cells with either MCF-7aro or T-47Daro cells. Testosterone (1 nM) increased cell growth to a similar degree for MCF-7/MCF-7aro co-culture (0.75 x 10(6) cells each type) as with MCF-7aro only (2- to 3-fold). In addition, the enzyme activities remained unchanged for MCF-7/MCF-7aro co-culture samples with and without androgen treatment, indicating that estrogen produced by transfected cells can also stimulate the growth of untransfected cells. The androgen response could be inhibited by an addition of 4-OHA (0.01-0.1 mM). For MCF-7/T-47Daro co-culture experiments, a clear induction of cell growth by androgen was observed, and the level of the increase was similar to that on T-47Daro only. However, for either culture with T-47D only or with MCF-7/T-47Daro co-culture, the aromatase activity was found to increase significantly after testosterone treatment. T-47Daro cells were not subjected to a clonal purification, and it is therefore thought that the androgen treatment may selectively stimulate the growth of high aromatase-expressing T-47Daro cells. These results indicate that estrogen synthesized by tumor aromatase can stimulate breast tumor growth in both an autocrine and a paracrine manner.

Effects of prenatal treatment with tritiated water on the developing brain in mouse

Pregnant mice were injected intraperitoneally with various doses of tritiated water on embryonic day 13. The litters received total cumulative absorbed beta-irradiation to a dose of 0, 0.1, 0.2, 0.4 or 0.8 Gy. We found that 0.4 Gy beta-irradiation caused a significant reduction in brain weight but not in body weight among 8-week-old mice. The highest dose (0.8 Gy) inhibited both body and brain development. A quantitative study showed that a significant reduction in cerebral pyramidal cells was present in the groups exposed to > or = 0.2 Gy. In tritiated, water-treated groups, the pyramidal cells reduced in a dose-dependent manner, with reductions ranging from 3 to 12%. The thickness of cerebral cortex was significantly reduced in the groups exposed to > or = 0.4 Gy. Numerical density of pyramidal cells was the most sensitive indicator of developmental disturbance of cerebral cortex manifested postnatally. No significant difference in the numerical density of Purkinje cells was found between the irradiated and control groups. These results demonstrated that the time at which the insult occurred was an important factor determining the resulting abnormalities.

Effects of different doses of gamma-radiation on the developing brain of mice

Morphogenetic changes in the developing brain induced by doses of 60Co gamma-irradiation ranging from 0 to 1.5 Gy on day 13 of pregnancy (E13) were studied in 6-week-old mice. Dose-related reductions in brain weight and cortical thickness (field 3 of Caviness) were significant for all irradiated groups, but abnormal cortical architecture was evident only in mice exposed to 1.0 and 1.5 Gy. Ectopic gray matter, enlarged lateral ventricles, and the absence of trunks from the corpus callosum were observed respectively in 23%, 30% and 10% of the mice exposed to 1.0 Gy, but these anomalies rose to 90%, 82% and 35% of the mice, respectively, when 1.5 Gy irradiation was applied. Brain malformations identical to the small heads and ectopic gray matter typically observed among atomic bomb survivors were reproduced in mice exposed to 1.5 Gy irradiation on E13.

Scanning microscopic evaluation on the development of the cerebral cortex in embryonic mouse subjected to gamma-irradiation

Morphological events occurring in the developing cerebral hemispheres of mice exposed to a single dose of 60Co gamma-irradiation 1.5 Gy on embryonic day 13 (E13) were evaluated by scanning microscope. Twenty-four hr after the exposure, both cell debris and surviving cells had poured out into the ventricular lumen. Radial glial fibers were more crumpled than in the controls. By day E15, proliferating cells in different stages of the cell cycle appeared in the ventricular zone. The glial fibers formed a network through the brain mantle. By E17 many migrating cells attached to the disorderly glial fibers appeared in the different layers of the thin cerebral mantle. These findings suggest that development of the glial fibers was interrupted as early as 24 hr after the single exposure, meaning that irradiation on the developing brain may disrupt neuronal migration.

Disturbance of neuronal migration in mouse cerebral cortex by low-dose gamma-radiation

We show that neuronal migration is disturbed by low-dose gamma-radiation of 0.24 Gy in the developing cerebral cortex of mice and suggest that neuronal progenitors in the S phase of mitosis are more sensitive than those in the G1/G0 phase. To pulse-label the fetal cells pregnant Slc:ICR mice were injected with bromodeoxyuridine (BrdU) at 10.00 pm on day 16 of pregnancy or at 9.30 am on day 17. The mice then were exposed to 0.24 Gy gamma- or sham-irradiation at 10.00 am on day 17 of pregnancy. At the time of exposure cells labeled on day 16 were regarded as having completed mitosis, and those labeled on day 17 as being in the S phase. Cell death in the fetal ventricular zone after exposure was negligible. Dams were allowed to give birth and rear their litters. Brain samples obtained from offspring on the 2nd day after birth and at 6 weeks of age were used for the immunohistochemical examination of BrdU-labeled cells. Labeled cells remaining in the ventricular zone were significantly more numerous in irradiated animals than in sham-exposed ones on the 2nd day after birth, in mice treated prenatally with BrdU on day 17 of pregnancy; whereas, mice treated with BrdU on day 16 showed no statistically significant difference. At 6 weeks of age, in both groups most of the labeled cells were present in layers II-III of the SmI cerebral cortex. But, in the irradiated animals the labeled cells in these layers were significantly fewer and those in layers IV-VI more numerous than in the sham-exposed mice in both group treated with BrdU on day 16 or 17.

Induction of a polarized micro-environment by human T cells and interferon-gamma in three-dimensional spheroid cultures of human endometrial epithelial cells

Expression of human leukocyte antigen (HLA)-DR molecules and proliferation of epithelium in human endometrium are polarized. We have suggested that the induction of such a polarized micro-environment is T cell and interferon (IFN)-gamma dependent. The present study was designed to demonstrate the induction of such a micro-environment around T cells and around the source of IFN-gamma. Spheroids reminiscent of endometrial glands were formed by allowing three-dimensional aggregation of endometrial epithelial cells of a cloned HLA-DR negative endometrial carcinoma cell line (ECC1) over agarose. Both HLA-DR expression and inhibition of proliferation were found to be directly dependent on the dose of IFN-gamma that was allowed to diffuse in the agarose beneath the spheroids. To show that the interaction of the epithelial cells with activated T cells also induces HLA-DR molecules in a paracrine fashion in the epithelial cells, ECC1 spheroids were co-cultured with increasing numbers of allogeneic peripheral blood T cells for various time-intervals. T cells bound to the ECC1 cells, and became activated as indicated by the expression of interleukin (IL)-2 receptor and HLA-DR molecules. A focal HLA-DR expression became apparent in the ECC1 cells adjacent to the T cells. As the number of T cells added to spheroid cultures was increased, a concomitant increase in the number of HLA-DR positive ECC1 cells occurred and HLA-DR immunoreactivity was enhanced in each cell. There was a corresponding decrease in the proliferation of the ECC1 cells in T cell-ECC1 spheroid co-cultures. Based on these data, we suggest that activation of T cells is associated with the induction of HLA-DR expression and inhibition of proliferation in a paracrine fashion in the epithelial cells and may be responsible for the creation of a polarized micro-environment in vivo.

Cytokine expression in human endometrium throughout the menstrual cycle

Recent evidence suggests that diverse endometrial functions may be regulated by cytokines. In this report, the presence of protein and mRNA of cytokines were studied in human endometrium throughout the menstrual cycle. The presence of the interleukin-1 (IL-1) alpha, interleukin-1 (IL-1) beta, interleukin receptor antagonist (IRAP), interleukin-6 (IL-6) and transforming growth factor (TGF)-alpha proteins were demonstrated by immunohistochemical staining. The IL-1 alpha and TGF-alpha proteins were strongly expressed and IL-1 beta protein was weakly expressed in all the cells in the stroma as well as epithelial cells. IRAP was markedly expressed in the cells with morphological features of macrophages scattered in the stroma, and the expression of IL-6 protein was predominant in the endometrial epithelium. Diffuse cytoplasmic expression of IL-1 alpha in endometrial epithelium during the proliferative phase contrasted markedly with its enhanced luminal expression during the secretory phase of the menstrual cycle. In addition, the presence of the mRNA of these cytokines in endometrium was established throughout the entire menstrual cycle by reverse transcription-polymerase chain reaction (RT-PCR). Abundant expression of cytokines in human endometrium emphasizes the significant roles that cytokines play in cell-cell interactions and in regulating endometrial functions.

[Experimental study on the immunosuppressive effects of qinghaosu and its derivative]

In this report the researches studied the immunosuppressive effects of Qinghaosu (QHS) and its derivative (DQHS). The results indicated that after 7-day successive administration i.p of QHS and DQHS at the dosage of 25-100 mg/kg, the amounts of anti-SRBC IgM PFC and IgG PFC in the murine spleen were decreased significantly (P less than 0.01). At the dosage of 100 mg/kg the QHS and DQHS were able to inhibit the DTH induced with BSA and the proliferative responses of murine spleen cells to Con A and LPS. These results suggested the suppressive effects of QHS and DQHS on both humoral and cellular immunities of mice. Interleukin-2 (IL-2) is an important mediate in the immune response and plays a critical role in the activation and differentiation of T and B lymphocytes. The results in this report showed a significant suppression of IL-2 production of murine spleen cells after 7-day administration i. p of QHS and DQHS, which suggested that the inhibition of IL-2 production could be the important one of the mechanisms of the immunosuppressive effects of QHS and DQHS.