RNAi knock-down of the Litopenaeus vannamei Toll gene (LvToll) significantly increases mortality and reduces bacterial clearance after challenge with Vibrio harveyi

In this study, we used real-time PCR to simultaneously monitor the responses of 12 key genes of the shrimp innate immune system in Litopenaeus vannamei after challenge with Vibrio harveyi. In the proPO activating system, we found that proPO was up-regulated (3.3× control at 36 hpi). The hemolymph clotting genes transglutaminase (TGase) and clotting protein were also up-regulated, as were 5 genes in the antimicrobial peptide system (ALF, Crustin, Lyz, PEN2 and PEN4), with only PEN3 showing no significant changes. In the antioxidant defense system, SOD was slightly elevated while GPx was substantially down-regulated. In the pattern recognition receptor system, at 24 hpi, the Toll gene (LvToll) showed the highest relative increase in expression level of all the investigated genes (15× greater than the sterile seawater control). In the second part of this study, when LvToll was knocked down by RNAi silencing, there was no effect on either survival rates or bacterial number in unchallenged shrimp. There was also no difference in mortality rates between control shrimp and LvToll-silenced shrimp when these two groups were challenged with a viral pathogen (white spot syndrome virus; WSSV). However, when LvToll-silenced shrimp were challenged by V. harveyi, there was a significant increase in mortality and bacterial CFU counts. We note that the increase in bacterial CFU count occurred even though treatment with EGFP dsRNA had the opposite effect of reducing the CFU counts. We conclude that LvToll is an important factor in the shrimp innate immune response to acute V. harveyi infection, but not to WSSV.     

Complexed prostate specific antigen provides significant enhancement of specificity compared with total prostate specific antigen for detecting prostate cancer

PURPOSE: Determining serum total prostate specific antigen (PSA) has proved to be a valuable diagnostic aid for detecting prostatic carcinoma, although the lack of specificity has limited its usefulness. Studies indicate that the use of percent free PSA would improve specificity while maintaining sensitivity. Since complexed PSA represents the major proportion of measurable PSA in serum, we determined whether it represents a single test alternative to the use of percent free PSA for the early detection of prostate cancer. MATERIALS AND METHODS: Archival serum was obtained from 385 men with no evidence of malignancy on biopsy and 272 with biopsy confirmed prostate cancer. We determined the concentration and proportion of total, complexed and free PSA. RESULTS: Receiver operating characteristics analysis using total PSA results from all samples (range 0.32 to 117 ng./ml.) indicated that the areas under the curve for complexed PSA alone as well as the free-to-total and complexed-to-total PSA ratios were similar and significantly greater than those for total PSA alone. Within the range of 85% to 95% sensitivity receiver operating characteristics analysis revealed that the specificity of complexed PSA was higher than that of total PSA and equivalent to that of the free-to-total PSA ratio. We noted a similar improvement in specificity in the 4 to 10 ng./ml. total PSA range. Using published cutoff values for complexed, total and percent free PSA when total PSA was in the 4 to 10 ng./ml. range the sensitivity and specificity of complexed and percent free PSA were similar. Within the 4 to 10 ng./ml. total PSA range the population of patients with no evidence of malignancy and complexed PSA below the upper limit was different with respect to total PSA from that with no evidence of malignancy and free PSA greater than 25%. CONCLUSIONS: The measurement of complexed PSA represents an alternative to the use of percent free PSA, although the patient populations identified by the 2 tests are different.     

Prevalence of antibodies to human T-lymphotropic virus types I and II in volunteer blood donors and high-risk groups in northwestern Greece

BACKGROUND: In addition to human immunodeficiency virus, human T- lymphotropic virus types I and II (HTLV-I/II) is prevalent among blood donors in the United States. In Greece, there are no epidemiologic data regarding the prevalence of HTLV-I/II among volunteer blood donors and high-risk groups. STUDY DESIGN AND METHODS: To determine the prevalence of HTLV-I/II infections in northwestern Greece, a seroepidemiologic study was conducted among volunteer blood donors, multiply transfused patients, heroin addicts, and chronic hemodialysis patients. The subjects were tested for serologic evidence of HTLV-I/II infection by enzyme immunoassays and specific protein immunoblot confirmatory test. RESULTS: None of the volunteer blood donors and heroin addicts had detectable antibodies to HTLV-I/II. Only 1 (1.45%) of the 69 multiply transfused patients had indeterminate results, while 2 (1.2%) of 163 hemodialysis patients were positive. CONCLUSION: In northwestern Greece, routine screening for HTLV-I and HTLV-II infections does not appear to be required. However, the finding of seropositivity among hemodialysis patients requires further evaluation of the origin of the infection, as its zero prevalence in this population seems to exclude transfusion transmission.     

Identification, chromosomal mapping and tissue-specific expression of hREV3 encoding a putative human DNA polymerase zeta

The Saccharomyces cerevisiae REV3 gene encodes the catalytic subunit of a non-essential DNA polymerase zeta, which is required for mutagenesis. The rev3 mutants significantly reduce both spontaneous and DNA damage- induced mutation rates. We have identified human cDNA clones from two different libraries whose deduced amino acid sequences bear remarkable homology to the yeast Rev3, and named this gene hREV3. The hREV3 gene was mapped to chromosome 1p32-33 by fluorescence in situ hybridization. The hREV3 encodes an mRNA of >10 kb, and its expression varies in different tissues and appears to be elevated in some but not all of the tumor cell lines we have examined. In light of recent reports of a putative mouse REV3, these results indicate that mammalian cells may also contain a mutagenic pathway which aids in cell survival at the cost of increased mutation.      

Fundus imaging with a nasal endoscope

Wide field fundus imaging is needed to diagnose, treat, and follow-up patients with retinal pathology. This is more applicable for pediatric patients as repeated evaluation is a challenge. The presently available imaging machines though provide high definition images, but carry the obvious disadvantages of either being costly or bulky or sometimes both, which limits its usage only to large centers. We hereby report a technique of fundus imaging using a nasal endoscope coupled with viscoelastic. A regular nasal endoscope with viscoelastic coupling was placed on the cornea to image the fundus of infants under general anesthesia. Wide angle fundus images of various fundus pathologies in infants could be obtained easily with readily available instruments and without the much financial investment for the institutes.     

Reduced basal salivary cortisol in children with asthma and allergic rhinitis

Aim: Reduced basal cortisol is reported in allergic disease. We investigated if basal salivary cortisol levels were reduced in children with asthma or allergic rhinitis, controlling for inhaled corticosteroids (ICS) use. Methods: Morning and evening saliva of asthmatic children aged 7–12 years (n = 50) and that of controls (n = 52) were sampled. A total of 19 asthmatics and four controls had allergic rhinitis. Healthy children were controls without rhinitis. Of all, 14 asthmatic children used low, and 12 used moderate or high doses of ICS. Cortisol was analysed by radioimmunoassay. Results: Morning salivary cortisol median (95% CI) was lower in asthmatics (8.7 (7.1, 9.7)) compared with that in controls (10.4 (9.6, 11.8); p = 0.006), which was similar for evening cortisol levels. Regression analyses demonstrated that asthmatics using moderate or high doses of ICS had reduced morning salivary cortisol adjusted (for age and gender) odds ratio (aOR) (95% CI) (0.54 (0.37, 0.80); p = 0.002) and reduced evening cortisol aOR (0.09 (0.01, 0.6); p = 0.02) compared with that in healthy children. Asthmatics with rhinitis on no or low doses of ICS had reduced morning cortisol aOR (0.73 (0.56, 0.96); p = 0.02) compared with that in healthy children. Conclusion: Asthmatic children on moderate or high doses of inhaled corticosteroids had reduced salivary cortisol, but co‐morbidity of asthma and rhinitis was also associated with reduced cortisol levels.