Neurokinin A-like immunoreactivity in rat primary sensory neurons; coexistence with substance P

Summary Rat spinal cord, dorsal root ganglia and skin were investigated employing immunohistochemical technique with specific antisera to neurokinin A and substance P. Neurokinin A-like immunoreactivity was detected in the spinal dorsal horn and skin with a similar distribution pattern as that of substance P-like immunoreactivity. After dorsal root transection a parallell decrease of neurokinin A and substance P-like immunoreactivity was observed in the dorsal horn. Using colchicine pretreatment a population of neurokinin A positive cell bodies was seen in the dorsal root ganglia, and by comparison of consecutive sections of the same cells stained for substance P it was revealed that these neurons also display substance P-like immunoreactivity. However, substance P-, but not neurokinin A-, immunoreactive cells were also observed. It is concluded that neurokinin A- and substance P-like immunoreactivity coexist in a population of rat primary sensory neurons.     

Tachykinin multiplicity in rat central nervous system as studied using antisera raised against substance P and neurokinin A

Antisera were raised in rabbits against the tachykinins neurokinin A (NKA) and substance P (SP). All NKA-antisera tested cross-reacted markedly with NKB, kassinin and eledoisin in radioimmunoassay (RIA), but virtually not with SP and physalaemin. Also when used for immunohistochemistry, one of the NKA-antisera was found to be virtually without cross-reactivity with SP. The most specific SP-antiserum did not cross-react with NKA but to some extent with NKB at the immunohistochemical level. Using these two antisera, the same distribution pattern of immunoreactivity was seen in both the rat substantia nigra and dorsal spinal cord. In neutral extracts of the substantia nigra, all NKA-antisera used for RIA detected a major component which eluted at the position of NKA in reverse phase high performance liquid chromatography, while no or only little immunoreactivity was detected at the position of NKB. A major component of substance P-like immunoreactivity (SPLI) co-eluting with SP and one or two minor SPLI-components were also detected in these extracts. An SP-antiserum, which cross-reacted markedly with physalaemin, detected an additional rather prominent component. In neutral water extracts of dorsal spinal cord the component detected with the NKA-antisera at the position of NKB, as well as one of the SPLI-components not eluting in the position of SP, were much more prominent than in the corresponding extracts of substantia nigra. In acetic acid extracts of both tissues, only one major SPLI-component co-eluting with SP could be detected, while only very small amounts of immunoreactivity eluting at the position of NKA and NKB (dorsal spinal cord only) could be detected using the NKA-antisera. The present results illustrate the importance of the extraction method used in immunochemical studies and demonstrate that the relative proportions of various tachykinins are markedly different in the rat substantia nigra and dorsal spinal cord.     

Comparison of a commercial biochemical kit and an oligonucleotide probe for identification of environmental isolates of Vibrio vulnificus

A. DALSGAARD, I. DALSGAARD, L. HØI AND J.L. LARSEN. 1996. Methods for the identification and isolation of environmental isolates of Vibrio vulnificus were evaluated. Alkaline peptone water supplemented with polymyxin B and colistin-polymyxin B-cellobiose agar were employed for the isolation of suspected V. vulnificus from water, sediment and shellfish samples. When comparing the identification of putative V. vulnificus obtained with the API 20E assay and an oligonucleotide probe, 29 API 20E profiles were obtained with only four profiles (representing 20 isolates) reaching the identification threshold of V. vulnificus among a total of 66 isolates hybridizing with the probe. The results indicated that, compared with colony hybridization, the API 20E assay was not adequate for the identification of environmental isolates of V. vulnificus .     

Nitrate Reduction in a Sulfate-Reducing Bacterium, Desulfovibrio desulfuricans, Isolated from Rice Paddy Soil: Sulfide Inhibition, Kinetics, and Regulation

From the second-highest dilution in a most-probable-number dilution series with lactate and sulfate as substrates and rice paddy soil as the inoculum, a strain of Desulfovibrio desulfuricans was isolated. In addition to reducing sulfate, sulfite, and thiosulfate, the strain also reduced nitrate to ammonia. The latter process was studied in detail, since the ability to reduce nitrate was strongly influenced by the presence of sulfide. Sulfide inhibited both growth on nitrate and nitrate reduction. A 70% inhibition of the nitrate reduction rate was obtained at 127 μM sulfide, and growth was inhibited by 50% at approximately 320 μM sulfide and was not detectable above 700 μM sulfide. In contrast, sulfate reduction was not affected at concentrations of up to 5 mM. After growth with sulfate, an induction period of 2 to 4 days was needed before nitrate reduction started. When nitrate and sulfate were present simultaneously, only sulfate was reduced, except when sulfate was present at very low concentrations (4 μM). At higher sulfate concentrations (500 μM), nitrate reduction was temporarily halted. The affinity for nitrate uptake was extremely high (K_m = 0.05 μM) compared with that for sulfate uptake (K_m = 5 μM). Thus, at low nitrate concentrations this bacterium is favored relative to denitrifiers (K_m = 1.8 to 13.7 μM) or other nitrate ammonifiers (e.g., Clostridium spp. [K_m = 500 μM]).     

Diseases and Injuries Associated with Mortality of Hatchery Reared Baltic Cod (Gadus morhua L.) Larvae

A cod hatching plant was established in 1992 on the island of Bornholm in the Baltic Sea in order to elucidate the possibilites for restocking of cod fry in this brackishwater system. The disease prevalence in 3 batches of hatchery-reared yolksac larvae from the Baltic cod (Gadus morhua L.) was monitored during the posthatch period. High prevalences of bacteriosis/mycosis, lordosis/scoliosis, injuries and protozoan endoparasitism were recorded. Vibrio sp. and Vibrio anguillarum serovar 04, 06, 08 in addition to nontypable strains and saprolegniaceous fungi were isolated from the larvae. The dinoflagellate-like endoparasites were located in the yolksac of the cod larvae.     

Isolation, purification and biochemical characterization of human placental interferons by tandem high-performance affinity chromatography.

Human placental trophoblasts, fibroblasts and the trophoblast-derived malignant cell JAR are potent producers of interferons (IFNs) when stimulated with Sendai virus. The three cell lines produced different levels and compositions of IFN-alpha subtypes and IFN-beta. Anti-IFN globulins, Cibacron Blue F3GA and Concanavalin A were covalently immobilized on pressure-stable, macroporous polymeric matrices derivatized with vinyl sulphone (HEMA-BIO 1000 VS and HEMA 1000 VS). These supports were packed in biocompatible PEEK columns and were coupled with switching valves, to develop a tandem high-performance affinity chromatographic (HPAC) method for the isolation, purification and biochemical characterization of the IFNs produced in Sendai virus-stimulated human placental trophoblasts, fibroblasts and trophoblast-derived malignant cell, JAR, cultures. Silver-stained SDS-PAGE and gel densitometric analysis revealed the purity of the purified proteins to be between 94 and 98%. Specific activities of the purified IFNs ranged between 0.37-2.76 x 10(8) IU/mg of protein with cumulative recoveries between 90 and 92.2%. The purified IFN components exhibited quantitatively different antiviral activities in human and bovine cell lines. The utility of the tandem method for the purification and characterization of human type 1 IFNs produced from other cell lines are also discussed.     

Sensibility and cutaneous reinnervation in free flaps

Sensibility and sensory reinnervation were investigated in 19 free flaps, predominantly located on the lower extremities, between 2 months and 3 years after flap transfer. All patients showed deep pressure sensibility. In 10 of the patients, primarily those examined late after surgery, a heat pain threshold was obtained at about 50 degrees C. None of the patients had superficial sensibility of any other modality. No neurofilament-positive sensory nerve fibers were observed in the dermis or epidermis. In one patient nerve fibers were detected in the subcutaneous tissue. It is concluded that patients will have deep pressure sensibility of the flap area even early after the operation and that most patients will develop a heat pain sensitivity, probably due to subcutaneous reinnervation.     

Comparative Genome Analysis Provides Insights into the Pathogenicity of Flavobacterium psychrophilum

Flavobacterium psychrophilum is a fish pathogen in salmonid aquaculture worldwide that causes cold water disease (CWD) and rainbow trout fry syndrome (RTFS). Comparative genome analyses of 11 F. psychrophilum isolates representing temporally and geographically distant populations were used to describe the F. psychrophilum pan-genome and to examine virulence factors, prophages, CRISPR arrays, and genomic islands present in the genomes. Analysis of the genomic DNA sequences were complemented with selected phenotypic characteristics of the strains. The pan genome analysis showed that F. psychrophilum could hold at least 3373 genes, while the core genome contained 1743 genes. On average, 67 new genes were detected for every new genome added to the analysis, indicating that F. psychrophilum possesses an open pan genome. The putative virulence factors were equally distributed among isolates, independent of geographic location, year of isolation and source of isolates. Only one prophage-related sequence was found which corresponded to the previously described prophage 6H, and appeared in 5 out of 11 isolates. CRISPR array analysis revealed two different loci with dissimilar spacer content, which only matched one sequence in the database, the temperate bacteriophage 6H. Genomic Islands (GIs) were identified in F. psychrophilum isolates 950106-1/1 and CSF 259–93, associated with toxins and antibiotic resistance. Finally, phenotypic characterization revealed a high degree of similarity among the strains with respect to biofilm formation and secretion of extracellular enzymes. Global scale dispersion of virulence factors in the genomes and the abilities for biofilm formation, hemolytic activity and secretion of extracellular enzymes among the strains suggested that F. psychrophilum isolates have a similar mode of action on adhesion, colonization and destruction of fish tissues across large spatial and temporal scales of occurrence. Overall, the genomic characterization and phenotypic properties may provide new insights to the mechanisms of pathogenicity in F. psychrophilum.     

The Ethnographic Use of Facebook in Everyday Life

New social media have become indispensable to people all over the world as platforms for communication, with Facebook being the most popular. Hence, platforms such as Facebook are also becoming crucial tools for ethnographers because much social life now exists ‘online’. What types of field relations stem from such social media-driven ethnography? And what kinds of data do these relations present to the ethnographer? These questions must be considered in order to understand the challenges Facebook and other social media pose to ethnographic methodology. This article focuses on how Facebook may play an important role even in ethnographic work concerned with questions other than how Facebook works as a social medium. Most importantly it allows the ethnographer to keep up-to-date with the field. I argue that ethnography is already in possession of the methodological tools critically to assess the validity and value of data gathered or produced via Facebook including issues such as authenticity which are also pertinent to digital ethnography.