Effects of rice straw/wood sawdust addition on the transport/conversion behaviors of heavy metals during the liquefaction of sewage sludge

Lignocellulosic biomass has been widely introduced into the liquefaction process of sewage sludge (SS) to improve the yield/quality of liquefaction products (bio-oil/biochar). This study explores the effect of adding rice straw (RS) and wood sawdust (WS) on the transport/conversion behaviors of heavy metals (HMs) during the liquefaction of SS. The introduction of lignocellulosic biomass, especially for RS, substantially lowers the total content of HMs in biochar. Most HMs (except Cd) still remain in biochar, although the introduction of RS/WS enhances the transport of HMs into bio-oils. The addition of RS/WS raises the percentage of HMs in active form, but the contents of bioavailable/leachable HMs are not considerably increased and even decreased in some cases, especially when RS is introduced. The overall pollution degree and environmental risk of HMs in biochars are lowered to a certain extent with the addition of RS/WS. Considering that the pollution degree and environmental risk of HMs present in biochars are still at a considerable level, appropriate pollution management measures should be undertaken when using such biochars for agricultural use.

[Early physical growth and disease analysis among children born delivered by HBsAg-positive mothers]

Objective: To estimate the early physical growth and disease in children born to HBsAg-positive mothers. Methods: This was a retrospective cohort study. Three areas as Xihu in Hangzhou, Lanxi in Jinhua, and Haiyan in Jiaxing in Zhejiang province were selected by cluster sampling. The growth outcomes of children born to HBsAg-positive mothers (exposure group) and matched 1∶1 women uninfected with HBV (control group) in 2014 were investigated and compared at birth, 6, 9, 12, and 18 months, respectively. There were totally 342 children in each group. Results: The incidences of low birth weight (LBW) for children born to exposure and control group were 1.8% (6/342), and 2.6% (9/342), respectively (P=0.433); and, rates of preterm birth were 2.3% (8/342), and 2.0% (7/342), respectively (P=0.794). The mean birth weight of children born to mothers without HBV infection (3.4±0.4) kg was dramatically higher than children in exposure group (3.3±0.4) kg (P=0.019). At 18 months, the average head circumference was significantly greater among children in control group (47.3±1.3) cm than children in exposure group (47.0±2.0) cm (P=0.038). Additional, mean birth weeks, height, weight, increases in height/weight/head circumference each month, weight/height/head circumference for age Z scores, proportion of growth retardation and low weight, disease prevalence were not observed statistically differences between two groups (P>0.05). All children born to HBsAg-positive mothers were received three-dose HBV vaccination. The rate of hepatitis B immunoglobulin for births born to HBsAg-positive was 98.8% (338/342). Mother to children transmission of HBV at 18 months was 1.0% (1/97). Conclusion: No significant differences in growth development and disease prevalence were found among children born to HBsAg-positive women and women without HBV infection.

MicroRNAs of the mesothorax in Qinlingacris elaeodes, an alpine grasshopper showing a wing polymorphism with unilateral wing form

MicroRNAs (miRNAs) are now recognized as key post-transcriptional regulators in regulation of phenotypic diversity. Qinlingacris elaeodes is a species of the alpine grasshopper, which is endemic to China. Adult individuals have three wing forms: wingless, unilateral-winged and short-winged. This is an ideal species to investigate the phenotypic plasticity, development and evolution of insect wings because of its case of unilateral wing form in both the sexes. We sequenced a small RNA library prepared from mesothoraxes of the adult grasshoppers using the Illumina deep sequencing technology. Approximately 12,792,458 raw reads were generated, of which the 854,580 high-quality reads were used only for miRNA identification. In this study, we identified 49 conserved miRNAs belonging to 41 families and 69 species-specific miRNAs. Moreover, seven miRNA*s were detected both for conserved miRNAs and species-specific miRNAs, which were supported by hairpin forming precursors based on polymerase chain reaction. This is the first description of miRNAs in alpine grasshoppers. The results provide a useful resource for further studies on molecular regulation and evolution of miRNAs in grasshoppers. These findings not only enrich the miRNAs for insects but also lay the groundwork for the study of post-transcriptional regulation of wing forms.

[Selection of reference genes for quantitative real-time PCR in six oil-tea camellia based on RNA]

qRT-PCR is becoming a routine tool in molecular biology to study gene expression. It is nec- essary to find stable reference genes when performing qRT-PCR. The expression of genes cloned in oil-tea camellia currently can't be accurately analyzed because of a lack of suitable reference genes. We collected different tissues (including roots, stems, leaves, flowers and seeds) from six oil-tea camellia species to determine stable reference genes. Five novel and ten traditional reference gene sequences were selected from the RNA-seq database of Camellia oleifera C. Abel seeds and specific PCR primers were designed for each. Cycle threshold (Ct) data were obtained from each reaction for all samples. Three different software tools, geNorm, NormFinder and BestKeeper were applied to calculate the expression stability of the candidate reference genes according to the Ct values. The results were similar between analyzed by the three software packages, and indicated that the traditional gene TUBa-3, AC17a and the novel gene CESA were relatively stable in all species and tissues. However, no genes were sufficiently stable across all species and tissues, thus the optimal number of reference genes required for accurate normalization varied from two to six. Finally, the relative expression ofsqualene synthase (SQS) and squalene epoxidase (SQE) genes related to important ingredients squalene and tea saponin in oil-tea camellia seeds were compared by using stable to less stable reference genes. The comparison results validated the selection of reference genes in the current study. In summary, different optimal numbers of suitable reference genes were found for the different tissues of six oil-tea camellia species.

Micellar-enhanced ultrafiltration of cadmium and methylene blue in synthetic wastewater using SDS

Single and simultaneous removal of Cd(2+) and methylene blue (MB) with sodium dodecyl sulfate (SDS) by micellar-enhanced ultrafiltration under different experimental conditions was investigated. In single removal process, with initial SDS concentration increasing, the removal efficiency of Cd(2+) and MB kept increasing and then decreased. When the initial concentrations of SDS and Cd(2+) were 1.0 cmc and 50 mg L(-1), respectively, the maximum removal efficiency of Cd(2+) was obtained as 99.2%. Removal efficiency of MB could achieve more than 99.9% with initial SDS concentration below 2.0 cmc. As compared with single Cd(2+) removal, the removal efficiency of Cd(2+) in the presence of MB was slightly higher with initial SDS concentration below 1.0 cmc, while decreased with the SDS concentration above 1.0 cmc. The maximum removal efficiency of Cd(2+) was 98.8% when initial concentrations of SDS and MB were 1.0 cmc and 4 mg L(-1), respectively. The removal efficiency of MB in the presence of Cd(2+) could achieve higher than 96.5%, which was only 3.4% less than the optimum result of the single removal. Meanwhile, effect of pH on removal efficiency of Cd(2+) was more significant than that of MB.

[Comparison for removing Cu2+ by micellar-enhanced ultrafiltration with SDS and SDBS]

Micellar-enhanced ultrafiltration was used to remove Cu2+ (Cu2+ was fixed at 0.6 mmol/L) from simulant aqueous solutions with SDS and SDBS as anionic surfactants respectively. Compare SDS and SDBS separation through permeate flux, permeate concentration, rejection and enrichment ratio. Experimental results show that the average permeate flux with SDS is always higher than that with SDBS [the average flux with SDS is 29.92 L x (m2 x h)(-1), while that with SDBS is only 16.55 L x (m2 x h)(-1)], the permeate concentration of SDS is always lower than that with SDBS. When the permeate concentration of Cu2+ close to zero, 2 mmol/L and 6 mmol/L of SDBS and SDS are respectively required. Cu2+ rejection and enrichment ratio with SDS are always higher than those with SDBS (the average Cu2+ rejection and enrichment ratio with SDS are respectively 85.06% and 4.18, while those with SDBS are 69.05% and 4.05 respectively). Besides, the average enrichment ratio of SDS is also higher than that of SDBS (SDS is up to 3.89, while SDBS is 3.13). Therefore, SDS is more suitable than the SDBS for removal of Cu2+.

Adsorption of surfactant micelles and Cd2+/Zn2+ in micellar-enhanced ultrafiltration

Micellar-enhanced ultrafiltration (MEUF) is a powerful treatment developed to remove heavy metals from wastewater. Efficient removal of Cd(2+)/Zn(2+) from wastewater was performed by MEUF using a polysulfone hollow ultrafiltration membrane, with sodium dodecyl sulfate (SDS) as the surfactant. The adsorption of surfactant micelles and Cd(2+)/Zn(2+) in MEUF was studied by changing the surfactant dosage and the Cd(2+)/Zn(2+) concentration in the feed. In addition, kinetics, adsorption isotherms, and thermodynamic rules were analyzed, and X-ray photoelectron spectroscopy (XPS) was conducted. It was found that when the Cd(2+)/Zn(2+) feed concentration was 50 mg/L, and the SDS dosage reached 2.15 g/L, the concentration of heavy metal ions in the permeate stabilized at around 1-4 mg/L, and the adsorption of Cd(2+)/Zn(2+) on SDS micelles followed second-order kinetics and the Langmuir isotherm laws. Adsorption is a spontaneous endothermic process in which the adsorption force is principally the attraction of opposite electrical charges.

Effect of groups difference in surfactant on solubilization of aqueous phenol using MEUF

Micellar-enhanced ultrafiltration (MEUF) was used to remove phenol from simulant aqueous solutions. The effect of groups difference of cationic surfactant on the solubilization of phenol was investigated through orthogonal experiment, namely, surfactants with the same length of hydrocarbon chain but different hydrophilic head group and vice versa. The effects on the solubilization of phenol of various operating parameters in the practical application of MEUF with OTAB were studied, including surfactant concentration, electrolyte concentration, feed phenol concentration, operating pressure, temperature, respectively. The results showed that the rejection of phenol increased in the order as follows: cetyltrimethylammonium bromide (CTAB)<octadecyl trimethyl ammonium bromide (OTAB)<cetylpyridinium chloride (CPC). With the introduction of feed surfactant concentration, the retention recovery of phenol increased. Electrolyte concentration, feed phenol concentration, operating pressure and temperature all had a slight influence on the retention of phenol.

Vascular endothelial growth factor and its receptor Flk-1 are expressed in the hippocampus following entorhinal deafferentation

Vascular endothelial growth factor (VEGF) has been thought of as a mitogen that promotes proliferation of endothelial cells and as a neurotrophic factor that stimulates neurogenesis and axonal growth in both peripheral and central nervous systems. To investigate the potential involvement of VEGF in the lesion-induced reorganization in the brain, the expression changes of VEGF and its receptor Flk-1 were analyzed in the mouse hippocampus after transections of the entorhinal afferents. In situ hybridization and immunohistochemistry showed the time-dependent expression upregulation of VEGF mRNA and protein in the entorhinally denervated hippocampal stratum lacunosum-moleculare and dentate outer molecular layer, which initiated by 3 days postlesion, reached its maximum at 7-15 days postlesion, still persisted by 30 days postlesion for protein, and recovered to the normal levels at 30 days postlesion for mRNA and at 60 days postlesion for protein. Double labeling of VEGF and glial fibrillary acidic protein revealed that VEGF-expressing cells in the denervated areas were reactive astrocytes. Semi-quantitative RT-PCR analysis showed that VEGF receptor Flk-1 mRNA was also time-dependently upregulated in the deafferented hippocampus with its maximal elevation at 7-15 days postlesion while the Flt-1 mRNA levels remained unchanged at any time point we examined. Immunohistochemistry analysis also displayed the upregulation of Flk-1 protein in the denervated stratum lacunosum-moleculare and outer molecular layer with a time course similar to that of VEGF mRNA upregulation. Flk-1 receptors were found to be expressed not only by reactive astrocytes but also by neurites, which most likely belong to sprouting axons by 7 days postlesion and regrowing dendrites by 15-30 days postlesion. From these data we suggest that the spatiotemporal upregulation of VEGF and Flk-1 in the hippocampus is induced by entorhinal deafferentation and that VEGF may be involved in the structural reorganization in the deafferented hippocampus via directly or indirectly promoting neurite growth.

Efficient propagation of human herpesvirus 6B in a T-cell line derived from a patient with adult T-cell leukemia/lymphoma

The efficient propagation of the OK strain of the B variant of human herpesvirus 6 (HHV-6B) was demonstrated in a line of T cells, TaY, established from the peripheral blood lymphocytes of a patient with adult T-cell leukemia/lymphoma (ATL). Growth of TaY cells depends on the presence of IL-2 and the cells harbor HTLV-I genomes. A severe cytopathic effect (CPE) was observed in many HHV-6B(OK)-infected TaY cells one week after infection. The release of virus from HHV-6B(OK)-infected TaY cells [TaY(OK)] was first detected after three days and increased rapidly for up to seven days after infection, as demonstrated by PCR. The titer of HHV-6B(OK) in the supernatant was comparable to the value of 10(3.5) TCID50/ml obtained with PHA-activated cord blood lymphocytes (CBL) that had been infected with HHV-6B(OK). The replication of the virus was shown to depend to a considerable extent on cell viability. Electron microscopy revealed many herpesvirus-type capsid- and enveloped-viruses in the nuclei and cytoplasm of degenerated cells in TaY(OK) cultures. The U1102 strain of HHV-6A and the Z29 strain of HHV-6B also infected TaY cells productively, as detected by PCR and an immunofluorescence test. These results suggest that the activation of CD4+ T lymphocytes with mitogens such as PHA or IL-2 and the expression of some cellular gene or the HTLV-I gene might be essential for efficient propagation of HHV-6B. TaY cells should play an important role in future investigations of cell-virus interactions and genetic variations or cell tropism of HHV-6 isolates since no cell line that shows propagation of both HHV-6A and HHV-6B has been reported to date.

Quantification of human herpesvirus 6 in healthy volunteers and patients with lymphoproliferative disorders by PCR-ELISA

To determine whether actual numbers of human herpesvirus 6 (HHV-6) genome in hematologic neoplasias are associated with disease condition, we developed a quantitative PCR-ELISA for detection of HHV-6. The amount of viral DNA was determined using externally amplified known amounts of the plasmid DNA containing the viral target sequences. First, we determined a viral burden in peripheral blood leukocytes obtained from 23 healthy volunteers and four specimens of lymph nodes with reactive hyperplasia. Using 1 microg of DNA, the prevalence of HHV-6 was 43.4% (10/23), ranging from 0 to 100 HHV-6 genomes in blood obtained from healthy volunteers. The amounts of HHV-6 genomes were < 10 in four non-neoplastic lymph node specimens. We next examined the amount of viral DNA in 21 blood specimens and 19 lymph node specimens obtained from patients with lymphoproliferative diseases (LPD) at the time of diagnosis. The number of HHV-6 genomes in most of the B-cell lymphoma was < 5 in both blood and lymph node specimens, however, two lymph node specimens obtained from immunoblastic lymphadenopathy (IBL) and T-cell lymphoma had very high levels of HHV-6 viral DNA (3705 and 810, respectively). We also found that HHV-6 genomes in peripheral blood were more than 1000 in two patients with chronic lymphocytic leukemia. For all LPD patients combined, there were significantly higher levels of viral DNA (200.6 +/- 654.8 HHV-6 genomes per 1 microg purified DNA) compared to those in healthy volunteers (10.0 +/- 21.0 HHV-6 genomes per 1 microg purified DNA) (P < 0.05). This study demonstrates that a high level of HHV-6 viral DNA is occasionally associated with LPD patients. Although it is still uncertain whether HHV-6 is related to the pathogenesis in LPD or not, our results suggest that measurement of HHV-6 genomes using PCR-ELISA may be useful not only to understand the mechanism of HHV-6 infection in hemopoietic neoplasia but also to manage the care of immnocompromised patients such as bone marrow transplant patients.

Polymorphism of ADH and ALDH genes among four ethnic groups in China and effects upon the risk for alcoholism

The alcohol dehydrogenases (ADHs) and aldehyde dehydrogenases (ALDHs) that metabolize ethanol are polymorphic. Different alleles encode subunits of the enzymes that differ in their rate of metabolizing ethanol. These polymorphisms are distributed differently among populations and have been shown to influence the risk for alcoholism in some Asian populations. We have examined the allele frequencies at the ADH2, ADH3, and ALDH2 loci in four populations from China (Han, Mongolian, Korean, and Elunchun) and in alcoholics within each population. The four populations differ in allele frequencies, with the Elunchun having a much lower frequency of ADH2*2 alleles, and the Mongolian and Elunchun having a much lower frequency of ALDH2*2 alleles. Within each population, alleles at one or more of these three loci are protective against alcoholism, although the populations differ in which loci play significant roles. The protective allele at each locus (ALDH2*2, ADH2*2, and ADH3*1) encodes a subunit that either metabolizes ethanol to acetaldehyde more rapidly or slows the conversion of acetaldehyde to acetate. Taken as a whole, data demonstrate that genetic differences in the enzymes that metabolize alcohol can substantially affect the risk for alcoholism.

[Expression of foreign tyrosine hydroxylase gene in the rat model of Parkinson's disease]

A total of 75 adult rats were used to produce hemiparkinson's disease (PD) model by unilateral injection of 6-hydroxydopamine (6-OHDA) into the right substantial nigra. Four weeks following the lesions, rats were tested for apomorphine (APO) -induced asymmetric rotation. Only rats that showed more than seven turns per minute were selected as PD models for transplantation. A tyrosine hydroxylase expression plasmid (pSVK3-TH) mixed with lipofectin was transplanted into the right striatum of 15 PD rats. Another 20 PD rats transplanted either with lipofectin or with pSVK3-TH served as controls. Every three days following transplantation, the performance of asymmetric rotation were tested and stained with the TH-immunohistochemistry. Only the animals grafted with pSVK3-TH mixed with lipofectin were found to show the decreased rotational behavior and a few TH-positive cells in the right striatum at the postgraft day 3-12, but not day 18. The results indicate that there exists a correlation between amelioration of asymmetric rotation and the TH gene expression in the denervated striatum. It is suggested that the lipofectin may mediate foreign TH gene expression in the PD rat brain.

Endogenous synaptogenesis in the deafferented dentate gyrus does not exclude synapse formation by embryonic entorhinal transplants

After partial deafferentation postsynaptic sites are reinnervated by local sprouting of remaining axons. We have investigated whether this process is sufficient to prevent new synapses being formed by transplanted embryonic tissue. We find that after unilateral entorhinal ablation endogenous sprouting by local axons is unable to reinnervate all the postsynaptic sites in the denervated outer dentate molecular layer. Axons from embryonic entorhinal tissue transplanted adjacent to the denervated area are able to reclaim a further proportion of the denervated postsynaptic sites. Thus, after a large lesion, endogenous sprouting is insufficient to preclude reinnervation by axons from embryonic transplants.

[Role of neural cell adhesion molecule and polysialic acid on the neuronal development and regeneration]

The formation of nervous system depends on intercellular adhesion. This review covered the role of neural cell adhesion molecule (NCAM) and its polysialic acid (PSA) moiety on the neuronal development and regeneration. Mediation of cell adhesion is the fundamental role of NCAM, while the existence of PSA on NCAM decreases cell adhesion by its specific structure. It is known that during the development of chick embryo, the expression of PSA at three critical phases determines whether motoneurons can accurately innervate muscle. Following the peripheral nerve lesions of adult rats, the expression of NCAM is regulated by the state of innervation of muscle. In the adult rat brain, the disconnection of entorhinal cortex and hippocampus results in the elevation of PSA in the outer molecular layer of the dentate gyrus, with this increased expression remains for at least 60 days after lesion. Existing data strongly suggest that the reexpression of PSA in the denervated area may promote axonal outgrowth of transplanted neurons and reconstruct synaptic connection with host.

Gene therapy of Parkinson disease model rat by direct injection of plasmid DNA-lipofectin complex

Lipofectin-mediated gene transfer was used to introduce plasmid harboring the tyrosine hydroxylase (TH) gene into the striatum of rats with lesions of the nigrostriatal pathway. The rotational asymmetry of Parkinson disease model rat was reduced quickly and significantly, suggesting that plasmid-DNA-transfected brain cells can generate L-dopa locally in the striatum in quantities sufficient to compensate partially for the loss of intrinsic striatal dopaminergic input. Immunohistochemical staining and reverse transcription polymerase chain reaction (RT-PCR) also confirm that striatal cells can express exogenous TH gene. Such in vivo plasmid DNA transfer strategy may be useful in other neurologic disease therapy, especially acute brain insults.

[Fate of human fetal dopamine neurons transplanted into rhesus monkey model of Parkinson's disease: a tyrosine hydroxylase immunocytochemical study]

To predicate the value of human fetal substantia nigra transplantation in clinical treatment of Parkinson's disease (PD), dissociated cells of substantia nigra from 8-12 week old abortive human fetus were grafted into the neostriatum of 5 adult rhesus monkeys with hemiparkinsonism induced by unilateral injection of MPTP. At 2, 5 and 12 months after transplanting the monkeys were sacrificed for tyrosine hydroxylase (TH) immunocytochemistry to examine the survival and possible synaptic contact of transplanted dopamine (DA) neurons. Transplanted TH immunoreactive cells took a pattern of patches scattered in the neostriatum. Each of the cell patches consisted of 3-10 cells. The TH immunoreactive fiber network was seen in the neostriatum. Electron microscopic survey revealed that TH+ buttons arising from grafted DA neurons formed symmetric or asymmetric synapses with TH- dendritic shafts/spines, and TH+ dendrites were seen to form synapses with TH- axons of the host. Additionally, there were a few synapses formed by TH+ axonal terminals with negative buttons. The results suggest that DA neurons from 8-12 week old abortive human fetus are able to survive grafting into the neostriatum of monkey, a species phylogenetically very close to human, and to establish reciprocal synaptic connectivity with the host even at 2 months post-transplanting. It is, therefore, inferable that embryonic human DA neurons transplanted into human neostriatum may have the same fate as in monkeys.

Accurate reconstruction of three complementary laminar afferents to the adult hippocampus by embryonic neural grafts

The hippocampus receives a complex pattern of afferent nerve fibres, segregated in such a way that the different types of afferent axons terminate in strictly demarcated, contiguous, but non-overlapping territories at different proximo-distal levels on the dendrites. In this paper we have used a mouse allelic marking system to show that the dentate, hippocampal, and entorhinal afferents can all be restored correctly and specifically to their proper terminal territories by axonal projections formed by embryonic transplants placed in direct contact with the appropriate denervated terminal territories in adult host brains, and that incorrect connections are not formed. We conclude that the signals for correct reinnervation are present (or inducible by deafferentation) in the adult hippocampus. The embryo-to-adult transplantation experiments show that neither the temporal nor the spatial aspects of cell-to-cell confrontation which occur in normal development are necessary for the formation of specific laminar patterns of reinnervation in the adult.

Embryonic entorhinal transplants project selectively to the deafferented entorhinal zone of adult mouse hippocampi, as demonstrated by the use of Thy-1 allelic immunohistochemistry. Effect of timing of transplantation in relation to deafferentation

The mouse Thy-1.1/Thy-1.2 allelic marking system is used to show that transplanted embryonic entorhinal cortex can reinnervate adult host hippocampi. The projection is limited to the appropriate terminal zones--viz. the outer two-thirds of the stratum moleculare of the dentate gyrus, and the stratum lacunosum-moleculare of the hippocampus--and extends for up to about 2 mm into the denervated host terminal field. The reconstruction of the entorhinal projections to the host requires direct contact between the embryonic donor tissue and the denervated adult host terminal field, and is dependent upon removal of the ipsilateral host entorhinal area. In the absence of an overall deafferenting host entorhinal lesion the transplanted entorhinal area forms only small local projections which are confined to areas which would have been locally deafferented as a result of direct damage to the host entorhinal afferents (i.e. during their intrahippocampal course) by the hippocampal lesion caused at the time when the transplant was inserted. The correct relative timing of deafferentation and transplantation is vital for the formation of the transplant-to-host projection. The host dendrites can be made receptive to entorhinal transplant projections by removal of the host entorhinal area at the time of transplantation. When deafferentation is performed first and transplantation is delayed, it is found that the deafferented host dendrites retain this receptivity even when deafferentation has been performed as much as two months before transplantation. Reversing the order of transplantation and deafferentation, however, shows that the transplants have only a transient ability to project to the deafferented host territory. Thus, transplants inserted and allowed to become established for one week before host deafferentation make very much reduced projections to the host, and from two weeks onwards are incapable of any detectable response to subsequent removal of the host entorhinal area. Coextensive with the formation of transplant-to-host entorhinodentate projections, the host entorhinal lesion also induces an intensification of the acetylcholinesterase staining of the host septodentate afferents in the denervated outer dentate stratum moleculare. The findings demonstrate the accurate reconstruction of a lost projection in adult brain by transplanting the appropriate type of embryonic tissue, but the results of altering the relative timing of deafferentation and transplantation raise currently unsolved questions about the nature of the competitive interactions between transplant and host axons.(ABSTRACT TRUNCATED AT 400 WORDS)

Extent of survival and vascularization of adult superior cervical sympathetic or nodose ganglia transplanted into the septal nuclei or choroid fissure of adult rats

Adult superior cervical sympathetic ganglia were auto-transplanted, and adult nodose ganglia were homografted into the septal nuclei or the choroid fissure of adult Wistar rats. At times from 4 h to 9 weeks after operation, the distribution of surviving transplanted neurons was compared with the development of the transplant vascularization, as visualized by transcardial Indian ink filling of the host vascular system. Within 24 h, the ganglionic neurons and Schwann cells of the interior of the transplants in both sites were necrotic. The surviving neurons and Schwann cells formed a shell, occupying those areas of the transplant periphery which were in direct contact with the host circulation. Occasional ink-filled vessels were evident at this time in transplants in the choroid fissure, but there were none in the septal nuclei, where vessels did not appear until the next day. Blood vessels reached the centre of the ganglia by 3-4 days in the choroid fissure and one week in the septal nuclei, the finest diameter capillaries forming last. At longer survivals there was a slow loss of neurons, notable between 1 and 2 months, and leading progressively (especially in the septal transplantation site) to the disappearance of all but a very small number of ganglionic neurons. The general findings were similar for both types of ganglion, and in both sites, but the initial cell loss was much greater for both types of ganglia in the septum (over 90%) as compared with about a 50% loss in the choroid fissure. The initial rapid cell loss was probably a result of ischaemia. The subsequent, slow progressive loss may be associated with failure to make or receive neuronal connections, or the absence of appropriate growth factors.