Hypothermia Promotes Survival of Ischemic Retinal Ganglion Cells.

PURPOSE: Ischemic stroke in retinal arteries leads to death of neural tissue and ultimately to blindness. The retina is known to die within 4 hours after onset of ischemia. It is debated whether hypothermia might increase the time window for medical treatment and thereby the chance of recovering sight. In order to characterize the time course of cell death during ischemia and potential beneficial effects of hypothermia in more detail, we investigated the survival of ganglion cells in ischemic pig and human retina as a function of time and temperature. METHODS: Eyes were obtained from minipigs and from human donors post mortem. Enucleated minipig eyes were stored for defined durations at three different temperatures (37 °C, 21 °C, and 4 °C). In order to assess the viability of the tissue, we measured ganglion cell activity (spiking) with multielectrode arrays. RESULTS: Minipig retinal ganglion cell function was severely compromised after 2 hours of ischemia at body temperature. After 4 hours, ganglion cells did not fire action potentials anymore. However, at 21 °C, ganglion cell activity was maintained under ischemic conditions for up to 12 hours, and for at least 50 hours at 4 °C. In postmortem human retina, we recorded ganglion cell activity in retinas received up to 27 hours after death. CONCLUSIONS: Our results demonstrate that hypothermia greatly increases survival of retinal ganglion cells exposed to ischemia. These results might be relevant for the future treatment of retinal ischemia.

External mirroring of inner chaos: blogging as experienced by the relatives of people with cancer.

BACKGROUND: Relatives of a person suffering from cancer risk being affected both physically and psychologically. Blogging has become increasingly popular as a forum for communicating experiences, but few studies have focused on what blogging about a relative's cancer journey means to the author. AIM: To illuminate relatives' experiences of blogging when a family member is in the end-of-life phase of cancer. METHOD: Telephone interviews were conducted with 12 people about their experiences of blogging during and after their family member's illness. The data was analysed using qualitative content analysis. FINDINGS: Blogging facilitated everyday life, introduced the relatives to new friends with similar experiences, helped them in their grief process, and helped them to preserve memories. The negative aspects were being misunderstood and publicly criticised as well as the feeling of providing readers with 'reality show' entertainment. CONCLUSION: Blogging was seen as a complement to professional care that contributed to the prevention of ill health.

Intrinsic neurons of Drosophila mushroom bodies express short neuropeptide F: relations to extrinsic neurons expressing different neurotransmitters.

Mushroom bodies constitute prominent paired neuropils in the brain of insects, known to be involved in higher olfactory processing and learning and memory. In Drosophila there are about 2,500 intrinsic mushroom body neurons, Kenyon cells, and a large number of different extrinsic neurons connecting the calyx, peduncle, and lobes to other portions of the brain. The neurotransmitter of the Kenyon cells has not been identified in any insect. Here we show expression of the gene snpf and its neuropeptide products (short neuropeptide F; sNPFs) in larval and adult Drosophila Kenyon cells by means of in situ hybridization and antisera against sequences of the precursor and two of the encoded peptides. Immunocytochemistry displays peptide in intrinsic neuronal processes in most parts of the mushroom body structures, except for a small core in the center of the peduncle and lobes and in the alpha'- and beta'-lobes. Weaker immunolabeling is seen in Kenyon cell bodies and processes in the calyx and initial peduncle and is strongest in the more distal portions of the lobes. We used different antisera and Gal4-driven green fluorescent protein to identify Kenyon cells and different populations of extrinsic neurons defined by their signal substances. Thus, we display neurotransmitter systems converging on Kenyon cells: neurons likely to utilize dopamine, tyramine/octopamine, glutamate, and acetylcholine. Attempts to identify other neurotransmitter components (including vesicular glutamate transporter) in Kenyon cells failed. However, it is likely that the Kenyon cells utilize an additional neurotransmitter, yet to be identified, and that the neuropeptides described here may represent cotransmitters.

Prolonged survival of Puumala hantavirus outside the host: evidence for indirect transmission via the environment.

The capability of rodent-borne viruses to survive outside the host is critical for the transmission dynamics within rodent populations and to humans. The transmission of Puumala virus (PUUV) in colonized bank voles (Clethrionomys glareolus) was investigated and additional longevity studies in cell culture with PUUV and Tula (TULV) hantaviruses were performed. Wild-type PUUV excreted by experimentally infected donor bank voles was shown to be transmitted indirectly between rodents through contaminated beddings, and maintained its infectivity to recipient voles at room temperature for 12-15 days. In cell culture supernatants, PUUV and TULV remained infectious for 5-11 days at room temperature and up to 18 days at 4 degrees C, but were inactivated after 24 h at 37 degrees C. Interestingly, a fraction of dried virus was still infectious after 1 h at 56 degrees C. These results demonstrated that hantavirus transmission does not require direct contact between rodents, or between rodents and humans, and that the indirect transmission of PUUV through contaminated environment takes place among the rodents for a prolonged period of time. The results also have implications for safety recommendations for work with hantaviruses and for preventive measures.

Mucosal host responses to bacteriuria in colonic and ileal neobladders.

OBJECTIVE: To study the local host response in patients with colonic and ileal neobladders, with or without bacteriuria. METHODS: Twenty-three patients with colonic neobladders and 19 with ileal neobladders were included. Eleven radical prostatectomy patients and seven healthy male volunteers were used as controls. Six urine samples were obtained from all patients and controls over a six-month period. The samples were cultured semiquantitatively, and the number of neutrophils and concentrations of the inflammatory mediators interleukin 6 and 8 (IL-6, IL-8) in the urine were determined. RESULTS: The prostatectomy patients and healthy volunteers had sterile urine, and concentrations of IL-6 and IL-8 were below the detection limit. Most (>70%) of the urine samples from patients with colonic and ileal neobladders showed anaerobic or aerobic bacterial growth, and uropathogens were identified in about 45% of the samples. The local host response was minimal or undetectable in the sterile urine samples. However, the host response was markedly induced by uropathogenic strains in the urine, but not by urinary carriage of nonpathogenic or anaerobic strains. IL-8, but not IL-6, was increased in colonic neobladders, which corresponds to the mucosal host responses in patients with intact lower urinary tracts and asymptomatic bacteriuria. In ileal neobladders, the IL-8 responses were higher, and levels of IL-6 were significantly increased. CONCLUSION: Neobladders exhibit a significant local host response to colonization with bacterial uropathogens. This reaction is more pronounced and includes IL-6 activation in ileal neobladders than in colonic neobladders.

Microbial flora in ileal and colonic neobladders.

OBJECTIVE: To describe bacterial colonization in patients with ileal and colonic neobladders. METHODS: Twenty-three patients with right colon neobladders, 30 with ileal neobladders, 11 who had undergone radical prostatectomy, and 6 healthy controls were included. Culture of clean-catch, midstream urine specimens was done weekly for 3 weeks, and this was repeated after 6 months. Residual urine was measured, and the patients were interviewed about leakage. All patients and controls were antibiotic free during the study except for 13 of the ileal neobladder patients, who were treated with trimethoprim 100mg daily. RESULTS: Urine cultures from controls and prostatectomy patients were negative for bacteria, whereas 67% of the specimens from patients with neobladders, not on antibiotic therapy, were culture positive, and half of these contained uropathogenic species, such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterococcus faecalis. Bacterial colonization (including uropathogenic strains) was strongly correlated with residual urine (p<0.005), but not with leakage. Anaerobic strains were found more frequently (p=0.04) in urine from ileal neobladders than in urine from colonic neobladders. The 13 patients with ileal neobladders and on prophylactic antibiotic therapy carried bacteriuria in 80% of the samples, the majority being anaerobic strains. Uropathogenic strains, mainly Enterecoccus faecalis was revealed in 30% of the samples. CONCLUSIONS: The lower urinary tract of patients with ileal or colonic neobladders is heavily colonized with potentially uropathogenic and anaerobic bacteria. Complete bladder emptying reduces the bacterial burden. Anaerobic colonization is increased in neobladders reconstructed from ileum. Prophylactic antibiotic therapy does not seem to reduce the bacterial burden, but interferes with the bacterial composition.

Improvement of binding of Puumala virus neutralization site resembling peptide with a second-generation phage library.

We have previously selected a peptide insert FPCDRLSGYWERGIPSPCVR recognizing the Puumala virus (PUUV) G2-glycoprotein-specific neutralizing monoclonal antibody (MAb) 1C9 with Kd of 2.85 x 10(-8) from a random peptide library X2CX14CX2 expressed on the pIII protein of the filamentous phage fd-tet. We have now created a second-generation phage-displayed peptide library in which each amino acid of the peptide was mutated randomly to another with a certain probability. Peptides were selected for higher affinity for MAb 1C9 and for a common binding motif for MAb 4G2 having an overlapping epitope with MAb 1C9 in G2 glycoprotein. The resulting peptides were synthesized as spots on cellulose membrane. Amino acid changes which improved the reactivity of the peptides to MAb 1C9 were combined in the peptide ATCDKLFGYYERGIPLPCAL with Kd of 1.49 x 10(-9) in biosensor measurements. Our results show that the binding properties of peptides, the affinity and the specificity can be improved and the binding specificity determining amino acids and structural factors can be analyzed by combining binding assays with synthetic peptides on membrane with the use of second-generation phage display libraries.