Herpes simplex virus type 1 infection induces upregulation of interleukin-23 (p19) mRNA expression in trigeminal ganglia of BALB/c mice.

We investigated the expression kinetics of several cytokines in trigeminal ganglia (TG) and in brains of BALB/c mice during the course of ocular herpes simplex virus type 1 (HSV-1) infection. All mice recovered from the infection within 2 weeks. The quantitative rapid real-time RT-PCR method was used to analyze interleukin-4 (IL-4), interferon-gamma (IFN-gamma), IL-12p35, IL-12p40, and the recently described IL-23 (p19) mRNA in TG, brain, and splenocyte samples. In TG, we found elevated expression of mRNA for IL-23 (p19) from early acute infection (day 3) to the beginning of the latent phase (day 14). The increase was not detected in brain or in the spleen. IL-4 expression occurred in both TG and brain from the beginning of the experiment to the latent phase. During the latent phase (days 14 and 31), IL-4 expression was significantly elevated in the brain when compared with the uninfected controls (p < 0.05). Considerable expression of IFN-gamma mRNA was detected in TG of mice during acute HSV-1 infection. The expression of IL-23 was detected also in the brains of the mice, even though no significant changes were found during the acute HSV-1 infection. This is, to our knowledge, the first report to show elevated expression of IL-23 (p19) mRNA (p < 0.05) during viral infection in TG of mice.     

Fluid reabsorption and glucose consumption in edematous rat lungs

Solute and water uptake were studied in isolated perfused rat lungs with airspaces filled with the perfusion fluid. The albumin in this solution was labelled with Evans blue (T-1824), and uptake of fluid from the airspaces was documented by an increase in T-1824 concentration in airway fluid of 6.5 +/- 1.6% (n = 5, SEM) at 1 hour and 12.2 +/- 0.9% (n = 10) at 2 hours. The only detectable osmotic force that could have contributed to a loss of fluid from the alveolar fluid was a decrease in airspace glucose concentrations, which fell much more rapidly (from 150 mg/dl to 58.7 +/- 7.1 mg/dl, n = 10, after 2 hours) than plasma glucose (from 150 mg/dl to 128.9 +/- 3.7 mg/dl). Addition of 5 X 10(-5) M terbutaline to the perfusate and airspace solutions nearly doubled fluid reabsorption at 1 hour, an effect that was inhibited by propranolol and did not appear to be related to glucose consumption. Exposure to terbutaline for 2 hours increased epithelial permeability to 3H-mannitol and 22Na+. These observations suggest that active sodium transport and epithelial metabolism or transport of glucose in airway fluid may each play a role in the reabsorption of edema fluid.     

Suppression of pro-inflammatory cytokine release by selective inhibition of inducible nitric oxide synthase in mucosal explants from patients with ulcerative colitis

BACKGROUND: In ulcerative colitis (UC), inflammatory damage is associated with increased production of pro-inflammatory cytokines and nitric oxide through the inducible nitric oxide synthase (iNOS) pathway. In an animal model of acute experimental colitis we have previously shown amelioration of inflammation with the highly selective iNOS inhibitor 1400W. The aim of the present study was to investigate the effects of selective iNOS inhibition on the production of pro-inflammatory cytokines by the colon mucosa in UC. METHODS: Inflamed and uninflamed mucosa from patients with severe UC were incubated with a highly selective iNOS inhibitor N-[3-(aminomethyl)benzyl]acetamidine (1400W), with a relatively selective cNOS inhibitor N(G)-nitro-L-arginine-methyl-esther (L-NAME), or with an NO-donor, S-nitroso-acetylpenicillamine (SNAP). Cytokine concentrations in the incubation medium were quantitated with ELISA. RESULTS: Compared to uninflamed mucosa there was an increase in iNOS protein and nitrotyrosine levels in inflamed mucosal samples. Immunolocalization of iNOS and nitrotyrosine showed their expression in inflammatory cells in the lamina propria. Expression of iNOS was also found in the epithelial brush border. Selective inhibition of iNOS suppressed the release of tumour necrosis factor alpha (TNF-alpha, by 66%) and interleukin-6 (IL-6, by 27%). The NO-donor, SNAP, augmented the secretion of TNF-alpha, IL-6 and IL-1-beta (by 62%, 52% and 175%, respectively) and decreased the release of IL-1 receptor antagonist (IL-1Ra, by 34%) by the inflamed mucosa. Moreover, in uninflamed samples, 1400W suppressed the production of TNF-alpha (by 69%) and incubation with SNAP decreased IL-6 concentrations by 48%. The cNOS over iNOS selective inhibitor L-NAME had no significant effects on the accumulation of cytokines. CONCLUSION: Selective inhibition of iNOS suppresses mucosal TNF-alpha and IL-6 release in active UC, whereas NO seems to exacerbate the inflammatory response. These results suggest that selective iNOS inhibition may have therapeutic promise in the treatment of UC.     

The severity of individual obstruction events is related to increased mortality rate in severe obstructive sleep apnea

Obstructive sleep apnea (OSA) is linked to an increased mortality rate. However, the severity of individual obstruction events is rarely considered quantitatively in clinical practice. We hypothesized that OSA with especially severe obstruction events would predispose a patient to greater health risks than OSA with a similar apnea–hypopnea index (AHI), but lower severity of individual events. This hypothesis was tested in a follow‐up (198.2 ± 24.7 months) of a population of 1068 men referred for ambulatory polygraphic recording due to suspected OSA. The recordings were analysed according to the guidelines of the American Academy of Sleep Medicine. Furthermore, a novel obstruction severity parameter was determined; this was defined as the product of duration of the individual obstruction event and area of the related desaturation event. Patients treated with continuous positive airway pressure (CPAP) were omitted. We identified 125 deceased patients from our original population and for 113 of these a matching alive patient with similar AHI, age, body mass index (BMI), smoking habits and follow‐up time could be found. The deceased patients with severe OSA (based on conventional AHI) showed higher obstruction severity values than their AHI‐matched alive controls. Based on the multivariate logistic regression analysis, obstruction severity was the only parameter which was related statistically significantly to mortality in the severe OSA category. Furthermore, 59% of all deceased patients and 83% of those who had severe OSA displayed higher obstruction severity than the AHI‐matched alive counterparts. To conclude, the obstruction severity parameter provided valuable prognostic information supplementing AHI. The obstruction severity parameter might improve recognition of the patients with the highest risk.     

Predicting the risk of extinction from shared ecological characteristics

Understanding the ultimate causes of population declines and extinction is vital in our quest to stop the currently rampant biodiversity loss. Comparison of ecological characteristics between threatened and nonthreatened species may reveal these ultimate causes. Here, we report an analysis of ecological characteristics of 23 threatened and 72 nonthreatened butterfly species. Our analysis reveals that threatened butterflies are characterized by narrow niche breadth, restricted resource distribution, poor dispersal ability, and short flight period. Based on the characteristics, we constructed an ecological extinction risk rank and predicted which of the currently nonthreatened species are at the highest risk of extinction. Our analysis reveals that two species currently classified as nonthreatened are, in fact, at high risk of extinction, and that the status of a further five species should be reconsidered.     

Time-dependent sensory nerve ingrowth into a bone conduction chamber

We studied time-dependent ingrowth of sensory nerve fibers into a bone defect in a rat bone conduction chamber model. In 10 male Sprague Dawley rats, a titanium chamber was implanted bilaterally in the proximal tibiae, representing an experimental bone defect. To mimic a clinical situation, the chambers were filled with a fresh blood clot. After 1, 2, 4, 6 and 8 weeks, 2 rats were fixed in vivo at each time before removal of specimens, and histological and immunohistochemical analyses. We used antisera against protein gene product 9.5, neural growth-associated protein 43/B-50, calcitonin gene-related peptide, and substance P, to locate regenerating sensory nerve fibers in the chamber. During bone defect healing, hematoxylin/eosin sections showed that new bone grew in through the ingrowth openings in the chamber, gradually filling it and replacing the blood clot. At 1 and 2 weeks after implantation, no nerve fibers could be detected. At 4, 6 and 8 weeks, however, small numbers of nerve fibers were seen in 8 of 11 specimens. The nerve fibers were located mainly in the dense fibrous tissue in close proximity to the new bone, and in some cases within the new forming bone. In this chamber model, the periosteum is not in contact with the bone ingrowth openings, and all ingrowing nerve fibers thus originated from the cortical bone, endosteum or bone marrow. We speculated that these late ingrowing sensory nerve fibers may actively participate in bone repair.     

Improved sensitivity of restriction endonuclease analysis of herpes simplex virus type 2 DNA with polyacrylamide gradient gel electrophoresis

Polyacrylamide gradient gel electrophoresis was used to resolve fragments of herpes simplex virus type 2 (HSV-2) DNA, produced by the restriction endonucleases Alu I, Bam HI, Pst I, and Sma I, which cleave the HSV-2 DNA into more than 30 fragments each. HSV-2 strains isolated from different individual patients could be easily distinguished from each other by the endonucleases Bam HI and Sma I. Successive virus isolates from a single person, analyzed using Alu I and Sma I, showed variability of fragment patterns. The effect of passaging the virus in cell cultures for several cycles was evaluated with the restriction endonuclease Alu I. No differences were found after 29 successive passages in VERO cells. Polyacrylamide gradient gel analysis of restriction endonuclease digests of HSV-2 DNA enables the use of enzymes that cleave the DNA into a great number of fragments, thus improving the sensitivity of analysis.     

Autolytic changes of human white matter: an electron microscopic and electrophoretic study

The effect of autolysis on the electrophoretic pattern of the 3H-labeled membrane glycoproteins derived from human brain white matter (WM) was investigated and correlated with electron microscopic findings. Samples were taken from the WM of outer zones of routine surgical specimens sent for pathologist's examination. The WM samples were incubated at +4 and +25 degrees C for 6 and 24 hr and analyzed by electron microscopy and by galactose oxidase labeling with subsequent SDS-polyacrylamide gradient gel electrophoresis. The effect of freezing and thawing was also studied. In electron microscopic examination myelin was found to have degenerated after an incubation of 24 hr at +4 and +25 degrees C, and it was severely disrupted after 24 hr at +25 degrees C, when a periaxonal network-like change was observed. The major labeled membrane glycoprotein band with an estimated molecular weight (MW) of 138,000 was stable during the first 24 hr of incubations at both +4 and +25 degrees C. No marked changes were noticed in the electrophoretic pattern of all of the WM membrane proteins labeled by [3H]acetic anhydride technique. In frozen and thawed specimens there was an increase in the intensity of the band with a MW of 86,500 and a new band appeared at the MW region of 25,000. The present results suggest that despite the apparent stability of the major glycoprotein band during the first 24 hr of autolysis, there are ultrastructural abnormalities in the myelin sheath, which should be taken into consideration during interpretation of changes in pathologic conditions.     

Herpesviruses in brains in Alzheimer's and Parkinson's diseases

We evaluated the association of HSV-1, HHV-6, and VZV with Alzheimer's disease (AD) and Parkinson's disease (PD). Brain specimens for viral DNA polymerase chain reaction represented 34 patients with AD, 40 with PD, and 40 controls. One AD patient (2.9%) was positive for HSV-1 DNA, 88.2% for HHV-6 DNA, and 26.5% for VZV DNA; 17.5% of PD patients were HSV-1 DNA-positive and 75% HHV-6-positive, whereas 40% had VZV DNA. Twenty-five percent of the controls were positive for HSV-1 DNA, 87.5% for HHV-6, and 27.5% for VZV. HSV-1, VZV, or HHV-6 DNA in brains was no additional risk factor for AD.