Quantitative electron microscopic studies on the innervation of the human thymus

Summary Quantitative electron microscopic studies have been carried out on the human thymus. According to the equation L _v =(2n)/F (Hennig, 1963) we have calculated that there is less than 0.204 mm nerve per 1 mm³ thymus tissue inside the blood-thymus-barrier (level of significance of 0.95). This result is compared to the degree of innervation in brown adipose tissue, which contains more than 160 mm nerve per 1 mm³ tissue. The biological significance of the paucity of neuronal elements in the thymus is undetermined.We are much obliged to Dipl. Ing. Dr. A. Hennig for his advice in the mathematical evaluation of our results.We are also indebted to Dr. med. A. Krug (Chir. Universitätsklinik Kiel) for human thymus material.This investigation was supported by the Deutsche Forschungsgemeinschaft.     

Regulation and effects of GDF-15 in the retina following optic nerve crush

Growth/differentiation factor-15 (GDF-15) is a distant member of the transforming growth factor-β superfamily and is ubiquitously expressed in the central nervous system. It is prominently upregulated in cerebral cortical and ischemic lesion paradigms. GDF-15 robustly promotes the survival of lesioned nigrostriatal dopaminergic neurons in vivo; GDF-15-deficient mice exhibit progressive postnatal motor and sensory neuron losses implying essential functions of GDF-15 in neuronal survival. We show that GDF-15 mRNA and protein are, respectively, six-fold and three-fold upregulated in the murine retina at 1 day after optic nerve crush, slightly elevated mRNA levels being maintained until day 28. However, the magnitude and time course of retinal ganglion cell (RGC) death are indistinguishable in knockout and control mice. Selected mRNAs implicated in the regulation of the death vs. survival of RGCs, including ATF3, Bad, Bcl-2 and caspase-8, were similarly regulated in both knockout and control retinae. Immunohistochemistry for tyrosine hydroxylase and choline acetyltransferase revealed no differences in staining patterns in the two genotypes. mRNA and protein levels of galanin, a putative neuroprotective factor and positive regulator of neuron survival and axonal regeneration, were prominently upregulated after crush in knockout retinae at day 3, as compared with control retinae, suggesting that GDF-15 acts as a physiological regulator of galanin. GDF-15 is therefore prominently upregulated in the retina after optic nerve crush but does not directly interfere with the magnitude and temporal progression of RGC death.     

Regulation of GDF-15, a distant TGF-β superfamily member,in a mouse model of cerebral ischemia

GDF-15 is a novel distant member of the TGF-β superfamily and is widely distributed in the brain and peripheral nervous system. We have previously reported that GDF-15 is a potent neurotrophic factor for lesioned dopaminergic neurons in the substantia nigra, and that GDF-15-deficient mice show progressive postnatal losses of motor and sensory neurons. We have now investigated the regulation of GDF-15 mRNA and immunoreactivity in the murine hippocampal formation and selected cortical areas following an ischemic lesion by occlusion of the middle cerebral artery (MCAO). MCAO prominently upregulates GDF-15 mRNA in the hippocampus and parietal cortex at 3 h and 24 h after lesion. GDF-15 immunoreactivity, which is hardly detectable in the unlesioned brain, is drastically upregulated in neurons identified by double-staining with NeuN. NeuN staining reveals that most, if not all, neurons in the granular layer of the dentate gyrus and pyramidal layers of the cornu ammonis become GDF-15-immunoreactive. Moderate induction of GDF-15 immunoreactivity has been observed in a small number of microglial cells identified by labeling with tomato lectin, whereas astroglial cells remain GDF-15-negative after MCAO. Comparative analysis of the size of the infarcted area after MCAO in GDF-15 wild-type and knockout mice has failed to reveal significant differences. Together, our data substantiate the notion that GDF-15 is prominently upregulated in the lesioned brain and might be involved in orchestrating post-lesional responses other than the trophic support of neurons.     

Localization of basic fibroblast growth factor in a subpopulation of rat sensory neurons

Summary The distribution of basic fibroblast growth factor (bFGF)-immunoreactivity (IR) was studied in rat sensory and autonomic ganglia. In postnatal and adult sympathetic superior cervical ganglia and in adult parasympathetic otic ganglia no bFGF-staining was found. Postnatal and adult neural crest-and placode-derived sensory ganglia displayed intensive bFGF-IR in a neuronal subpopulation. This subpopulation was characterized by use of consecutive sections of adult dorsal root ganglia stained with antibodies against substance P, somatostatin, bombesin, and bFGF. Basic FGF was colocalized with the somatostatin/bombesin subpopulation but not with substance P.     

Herbivore‐induced poplar cytochrome P450 enzymes of the CYP71 family convert aldoximes to nitriles which repel a generalist caterpillar

Numerous plant species emit volatile nitriles upon herbivory, but the biosynthesis as well as the relevance of these nitrogenous compounds in plant–insect interactions remains unknown. Populus trichocarpa has been shown to produce a complex blend of nitrogenous volatiles, including aldoximes and nitriles, after herbivore attack. The aldoximes were previously reported to be derived from amino acids by the action of cytochrome P450 enzymes of the CYP79 family. Here we show that nitriles are derived from aldoximes by another type of P450 enzyme in P. trichocarpa. First, feeding of deuterium‐labeled phenylacetaldoxime to poplar leaves resulted in incorporation of the label into benzyl cyanide, demonstrating that poplar volatile nitriles are derived from aldoximes. Then two P450 enzymes, CYP71B40v3 and CYP71B41v2, were characterized that produce aliphatic and aromatic nitriles from their respective aldoxime precursors. Both possess typical P450 sequence motifs but do not require added NADPH or cytochrome P450 reductase for catalysis. Since both enzymes are expressed after feeding by gypsy moth caterpillars, they are likely to be involved in herbivore‐induced volatile nitrile emission in P. trichocarpa. Olfactometer experiments showed that these volatile nitriles have a strong repellent activity against gypsy moth caterpillars, suggesting they play a role in induced direct defense against poplar herbivores.     

Infectious salmon anaemia virus (ISAV) isolated from the ISA disease outbreaks in Chile diverged from ISAV isolates from Norway around 1996 and was disseminated around 2005, based on surface glycoprotein gene sequences

Background

All viruses in the family Bunyaviridae possess a tripartite genome, consisting of a small, a medium, and a large RNA segment. Bunyaviruses therefore possess considerable evolutionary potential, attributable to both intramolecular changes and to genome segment reassortment. Hantaviruses (family Bunyaviridae, genus Hantavirus) are known to cause human hemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome. The primary reservoir host of Sin Nombre virus is the deer mouse (Peromyscus maniculatus), which is widely distributed in North America. We investigated the prevalence of intramolecular changes and of genomic reassortment among Sin Nombre viruses detected in deer mice in three western states.

Methods

Portions of the Sin Nombre virus small (S) and medium (M) RNA segments were amplified by RT-PCR from kidney, lung, liver and spleen of seropositive peromyscine rodents, principally deer mice, collected in Colorado, New Mexico and Montana from 1995 to 2007. Both a 142 nucleotide (nt) amplicon of the M segment, encoding a portion of the G2 transmembrane glycoprotein, and a 751 nt amplicon of the S segment, encoding part of the nucleocapsid protein, were cloned and sequenced from 19 deer mice and from one brush mouse (P. boylii), S RNA but not M RNA from one deer mouse, and M RNA but not S RNA from another deer mouse.

Results

Two of 20 viruses were found to be reassortants. Within virus sequences from different rodents, the average rate of synonymous substitutions among all pair-wise comparisons (π_s) was 0.378 in the M segment and 0.312 in the S segment sequences. The replacement substitution rate (π_a) was 7.0 × 10^-4 in the M segment and 17.3 × 10^-4 in the S segment sequences. The low π_a relative to π_s suggests strong purifying selection and this was confirmed by a Fu and Li analysis. The absolute rate of molecular evolution of the M segment was 6.76 × 10^-3 substitutions/site/year. The absolute age of the M segment tree was estimated to be 37 years. In the S segment the rate of molecular evolution was 1.93 × 10^-3 substitutions/site/year and the absolute age of the tree was 106 years. Assuming that mice were infected with a single Sin Nombre virus genotype, phylogenetic analyses revealed that 10% (2/20) of viruses were reassortants, similar to the 14% (6/43) found in a previous report.

Conclusion

Age estimates from both segments suggest that Sin Nombre virus has evolved within the past 37–106 years. The rates of evolutionary changes reported here suggest that Sin Nombre virus M and S segment reassortment occurs frequently in nature.     

Neuronotrophic Factors Released by C6 Glioma Cells

Glial cells have been shown previously to release factors that promote survival of central and peripheral neurons [neuronotrophic factors (NTFs)]. We have investigated the release of NTFs by C6 cells, a rat glioma cell line, under different modes of conditioning. Media conditioned in the presence or absence of serum [C6 cell conditioned media (C6CMs)] were analyzed using biological, biochemical, and immunological assays. We report that (a) nuclear and cytoskeletal proteins were not present in C6CMs, indicating that C6CM proteins result from release by C6 cells rather than from cell death; (b) C6CM contained 1-3 micrograms protein/ml, corresponding to a secretion rate of about 0.5 pg protein per cell and day; (c) C6CM contained the neurite-promoting factor laminin and low amounts of nerve growth factor; (d) the presence of fetal calf serum in the culture medium was essential for synthesis and release of NTFs; and (e) our C6CM contained at least three NTFs differing by their temporal secretory patterns and three NTFs differing by biochemical properties, indicating that C6 cells produce and secrete six different NTFs. Within these, nerve growth factor seems to be the only established NTF.     

Rilonacept in the treatment of acute gouty arthritis: a randomized,controlled clinical trial using indomethacin as the active comparator

Introduction

In phase-3 clinical trials, the interleukin (IL-1) blocker, rilonacept (IL-1 Trap), demonstrated efficacy for gout flare prevention during initiation of urate-lowering therapy. This trial evaluated rilonacept added to a standard-of-care, indomethacin, for treatment of acute gout flares.

Methods

Adults, aged 18-70 years, with gout presenting within 48 hours of flare onset and having at least moderate pain as well as swelling and tenderness in the index joint were randomized to subcutaneous (SC) rilonacept 320 mg at baseline plus oral indomethacin 50 mg TID for 3 days followed by 25 mg TID for up to 9 days (n = 74); SC placebo at baseline plus oral indomethacin as above (n = 76); or SC rilonacept 320 mg at baseline plus oral placebo (n = 75). The primary efficacy endpoint was change in pain in the index joint (patient-reported using a Likert scale (0 = none; 4 = extreme)) from baseline to the average of values at 24, 48 and 72 hours (composite time point) for rilonacept plus indomethacin versus indomethacin alone. Comparison of rilonacept monotherapy with indomethacin monotherapy was dependent on demonstration of significance for the primary endpoint. Safety evaluation included clinical laboratory and adverse event (AE) assessments.

Results

Patient characteristics were comparable among the groups; the population was predominantly male (94.1%), white (75.7%), with mean ± SD age of 50.3 ± 10.6 years. All treatment groups reported within-group pain reductions from baseline (P < 0.0001). Although primary endpoint pain reduction was greater with rilonacept plus indomethacin (-1.55 ± 0.92) relative to indomethacin alone (-1.40 ± 0.96), the difference was not statistically significant (P = 0.33), so formal comparison between monotherapy groups was not performed. Pain reduction over the 72-hour period with rilonacept alone (-0.69 ± 0.97) was less than that in the other groups, but pain reduction was similar among groups at 72 hours. Treatment with rilonacept was well-tolerated with no reported serious AEs related to rilonacept. Across all groups, the most frequent AEs were headache and dizziness.

Conclusions

Although generally well-tolerated, rilonacept in combination with indomethacin and rilonacept alone did not provide additional pain relief over 72 hours relative to indomethacin alone in patients with acute gout flare.

Trial registration

ClinicalTrials.gov registration number {"type":"clinical-trial","attrs":{"text":"NCT00855920","term_id":"NCT00855920"}}NCT00855920.     

Fine structure and innervation of the avian adrenal gland

Summary Apart from cholinergic nerve fibers, which make up the main part of efferent fibers to the avian adrenal gland (Unsicker, 1973b), adrenergic, purinergic and afferent nerve fibers occur. Adrenergic nerve fibers are much more rare than cholinergic fibers. With the Falck-Hillarp fluorescence method they can be demonstrated in the capsule of the gland, in the pericapsular tissue and near blood vessels. By their green fluorescent varicosities they may be distinguished characteristically from undulating yellow fluorescent ramifications of small nerve cells which are found in the ganglia of the adrenal gland and below the capsule. The varicosities of adrenergic axons exhibit small (450 to 700 Å in diameter) and large (900 to 1300 Å in diameter) granular vesicles with a dense core which is usually situated excentrically. After the application of 6-hydroxydopamine degenerative changes appear in the varicosities. Adrenergic axons are not confined to blood vessels but can be found as well in close proximity of chromaffin cells. Probably adrenergic fibers are the axons of large ganglion cells which are situated mainly within the ganglia of the adrenal gland and in the periphery of the organ and whose dendritic endings show small granular vesicles after treatment with 6-OHDA.A third type of nerve fiber is characterized by varicosities containing dense-cored vesicles with a thin light halo, the mean diameter (1250 Å) of which exceeds that of the morphologically similar granular vesicles in cholinergic synapses. Those fibers resemble neurosecretory and purinergic axons and are therefore called p-type fibers. They cannot be stained with chromalum-hematoxyline-phloxine. Axon dilations showing aggregates of mitochondria, myelin bodies and dense-cored vesicles of different shape and diameter are considered to be afferent nerve endings. Blood vessels in the capsule of the gland are innervated by both cholinergic and adrenergic fibers.Supported by a grant from the Deutsche Forschungsgemeinschaft (Un 34/1).