Laboratory studies on egg and faecal pellet production of Centropages typicus: effect of age, effect of temperature, individual variability

The rates of egg production of individually reared females ofCentropager typicus have been observed from the moulting C5-adultto death under constant conditions of food (10 000 cells ml^–1of Hymenomonas elongara) and temperature (15 and 20°C).Preliminaiy experiments showed that virgin females could produceunfecunded eggs, but that the distinctive spines of the eggsof C.typicus were only obtained after fecundation occurred.High and continuous egg production needs several matings, andthe following experiments were run with a couple. In all experiments,both males and females fed and produced faecal pellets. Thefemales show a high variability in spawning life periods, inspawning rhythms, in daily rates and, consequently, in cumulatednumbers of eggs spawned during their life. The highest dailyrates of egg production were obtained in the first half of thefemale's life, and were as high at 20°C as at 15°C.Nevertheless, the females survived longer at 15°C than at20°C, and finally produced 47.6% more eggs during theirwhole life at 15°C than at 20°C, which can be partiallydue to the difference in size (almost 10% bigger at 15°Cthan at 20°C). The production of faecal pellets occurredduring the whole of life and was more regular than egg production,with a maximum daily rate in the first part of life, and showeda decrease until death. The decline in daily egg productionwith age was parallel to the decrease in daily faecal pelletproduction. The daily production of faecal pellets was higherat 15°C than at 20°C. At 20°C, a good correlationwas observed between the total egg production per female andthe total faecal pellet production per female. The individual-basedegg production rates of our experiments have been compared withrates obtained in different conditions by several authors, andwere lower than in other published studies, probably due tothe food offered. We emphasize the difficulties of comparingresults which have been obtained for the entire life of thefemales with those based on daily egg production. The totalegg production of a female is an important parameter in regardto the population d because it fixes the maximal rate of losses(mortality plus dispersion) for which a population can continueto develop.     

PD-1/PD-L1 pathway: Basic biology and role in cancer immunotherapy

Over the course of past few years, cancer immunotherapy has been accompanied with promising results. However, preliminary investigations with respect to immunotherapy concentrated mostly on targeting the immune checkpoints, nowadays, emerge as the most efficient strategy to raise beneficial antitumor immune responses. Programmed cell death protein 1 (PD-1) plays an important role in subsiding immune responses and promoting self-tolerance through suppressing the activity of T cells and promoting differentiation of regulatory T cells. PD-1 is considered as an immune checkpoint and protects against autoimmune responses through both induction of apoptosis in antigen-specific T cells and inhibiting apoptosis in regulatory T cells. Several clinical trials exerting PD-1 monoclonal antibodies as well as other immune-checkpoint blockades have had prosperous outcomes and opened new horizons in tumor immunotherapy. Nonetheless, a bulk of patients have failed to respond to these newly emerging immune-based approach and the survival rate was not satisfying. Additional strategies, especially combination therapies, has been initiated and been further promising. Attempts to identify novel and well-suited predictive biomarkers are also sensed. In this review, the promotion of cancer immunotherapy targeting PD-1 immunoinhibitory pathway is discussed.     

Biology of Lysiphlebus fabarum following cold storage of larvae and pupae

Cold storage is one means of preserving parasitoids prior to release in augmentation biological control programs. This study examined the feasibility of storing larval and pupal stages of a sexual population of Lysiphlebus fabarum Marshall (Hymenoptera: Braconidae: Aphidiinae) at 6 ± 1 and 8 ± 1 °C, 50–60% r.h., and L14:D10 photoperiod. These life stages were stored for periods of 1, 2, and 3 weeks under fluctuating thermal regimes (2 h daily at 21 ± 1 °C). Generally, pupae gave better results than larvae, and 6 °C was better than 8 °C, considering wasp survival, wasp size (tibial and antennal lengths), egg load, and egg size. The best results were obtained with pupae stored for 2 weeks under a fluctuating temperature regime at 6 °C. Females emerging from this treatment did not differ from controls (developing directly at 21 °C) in body size, egg size, or progeny sex ratio, and suffered less than 20% mortality. Egg loads were reduced in these wasps, but the reductions were substantially less than occurred in other 2‐week‐storage treatments. Wasps stored in this manner successfully parasitized similar numbers of aphids as controls and produced similar progeny sex ratios. These results reveal a suitable set of low‐temperature conditions that can be used to delay the development of L. fabarum for 2 weeks with minimal impact on wasp fitness.     

Discordance in diagnosis of osteoporosis using spine and hip bone densitometry

BACKGROUND: Diagnostic discordance for osteoporosis is the observation that the T-score of an individual patient varies from one key measurement site to another, falling into two different diagnostic categories identified by the World Health Organization (WHO) classification system. This study was conducted to evaluate the presence and risk factors for this phenomenon in a large sample of Iranian population. METHODS: Demographic data, anthropometric measurements, and risk factors for osteoporosis were derived from a database on 4229 patients referred to a community-based outpatient osteoporosis testing center from 2000 to 2003. Dual-energy X-ray absorptiometry (DXA) was performed on L1-L4 lumbar spine and total hip for all cases. Minor discordance was defined as present when the difference between two sites was no more than one WHO diagnostic class. Major discordance was present when one site is osteoporotic and the other is normal. Subjects with incomplete data were excluded. RESULTS: In 4188 participants (3848 female, mean age 53.4 +/- 11.8 years), major discordance, minor discordance, and concordance of T-scores were seen in 2.7%, 38.9% and 58.3%, respectively. In multivariate logistic regression analysis, older age, menopause, obesity, and belated menopause were recognized as risk factors and hormone replacement therapy as a protective factor against T-score discordance. CONCLUSION: The high prevalence of T-score discordance may lead to problems in interpretation of the densitometry results for some patients. This phenomenon should be regarded as a real and prevalent finding and physicians should develop a particular strategy approaching to these patients.     

Risk of Gastric Cancer by Water Source: Evidence from the Golestan Case-Control Study

Background

Gastric cancer (GC) is the world’s fifth most common cancer, and the third leading cause of cancer-related death. Over 70% of incident cases and deaths occur in developing countries. We explored whether disparities in access to improved drinking water sources were associated with GC risk in the Golestan Gastric Cancer Case Control Study.

Methods and Findings

306 cases and 605 controls were matched on age, gender, and place of residence. We conducted unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CI), adjusted for age, gender, ethnicity, marital status, education, head of household education, place of birth and residence, homeownership, home size, wealth score, vegetable consumption, and H. pylori seropositivity. Fully-adjusted ORs were 0.23 (95% CI: 0.05–1.04) for chlorinated well water, 4.58 (95% CI: 2.07–10.16) for unchlorinated well water, 4.26 (95% CI: 1.81–10.04) for surface water, 1.11 (95% CI: 0.61–2.03) for water from cisterns, and 1.79 (95% CI: 1.20–2.69) for all unpiped sources, compared to in-home piped water. Comparing unchlorinated water to chlorinated water, we found over a two-fold increased GC risk (OR 2.37, 95% CI: 1.56–3.61).

Conclusions

Unpiped and unchlorinated drinking water sources, particularly wells and surface water, were significantly associated with the risk of GC.     

Temperature and Ca2+ ion as modulators in cellular immunity of the Sunn pest Eurygaster integriceps Puton (Heteroptera: Scutelleridae)

Environmental conditions in addition to divalent cations may affect the interactions between pathogens and insects. Elucidation of factors which modulate insect immune responses could be a significant part of investigations in this area. In this study, adults of Eurygaster integriceps, as the destructive pest of wheat, were kept at different temperatures in addition to injection with different concentrations of Ca²⁺ to find the effect on cellular immune reactions against Beauveria bassiana. Results showed that total and differentiate hemocyte numbers, nodule formation and phenoloxidase activity increased with elevation of temperature so that the higher values were obtained at 30 and 40°C at various intervals. Higher concentrations of Ca²⁺ ion (5 mM) caused an increase in plasmatocyte length and width especially after 60 min. Similar results were observed for nodule formation and phenoloxidase activity of E. integriceps adults after injection by B. bassiana spores and phenoloxidase activity. It is clear from the current study that thermoregulation and Ca²⁺ ion can positively affect the hemocyte numbers especially plasmatocytes and granulocytes, nodule formation and phenoloxidase activity in E. integriceps. The understanding of modulators of the insect immune response may directly influence novel approaches to obtain safe and effective biological control agents.