Lamellate bodies in the nuclei of dragonfly (odonata) oocytes

Summary Concentrically lamellate spherical bodies have been observed in the oocyte nuclei of the anisopterous dragonflyCordulia aenea. In their ultrastructure, these bodies resemble the cortical granules reported from the cytoplasm of the sea urchin oocytes. The lamellate bodies ofCordulia are compared with other lamellate systems known to exist in nuclei. It is suggested that the nuclear lamellate spheres ofCordulia may be homologous with the somewhat less regular lamellate bodies described from maize microspores.The competent help of MissRiitta Lallukka, M. A., is acknowledged with many thanks. We are grateful to ProfessorsESko Suomalainen andAntti Telkkä for helpful suggestions. Grants for the study have been received from the National Research Council for Sciences, from the University of Helsinki and from the Emil Aaltonen Foundation.     

Body Size at Birth Is Associated with Food and Nutrient Intake in Adulthood

Background

Small body size at birth is associated with an increased risk of cardiovascular disease and type 2 diabetes. Dietary habits are tightly linked with these disorders, but the association between body size at birth and adult diet has been little studied. We examined the association between body size at birth and intake of foods and macronutrients in adulthood.

Methodology/Principal Findings

We studied 1797 participants, aged 56 to 70, of the Helsinki Birth Cohort Study, whose birth weight and length were recorded. Preterm births were excluded. During a clinical study, diet was assessed with a validated food-frequency questionnaire. A linear regression model adjusted for potential confounders was used to assess the associations. Intake of fruits and berries was 13.26 g (95% confidence interval [CI]: 0.56, 25.96) higher per 1 kg/m³ increase in ponderal index (PI) at birth, and 83.16 g (95% CI: 17.76, 148.56) higher per 1 kg higher birth weight. One unit higher PI at birth was associated with 0.14% of energy (E%) lower intake of fat (95% CI: -0.26, -0.03) and 0.18 E% higher intake of carbohydrates (95% CI: 0.04, 0.32) as well as 0.08 E% higher sucrose (95% CI: 0.00, 0.15), 0.05 E% higher fructose (95% CI: 0.01, 0.09), and 0.18 g higher fiber (95% CI: 0.02, 0.34) intake in adulthood. Similar associations were observed between birth weight and macronutrient intake.

Conclusions

Prenatal growth may modify later life food and macronutrient intake. Altered dietary habits could potentially explain an increased risk of chronic disease in individuals born with small body size.     

Matrix metalloproteinases in inflammation

Background

Matrix metalloproteinases (MMPs) are a family of ubiquitously expressed zinc-dependent endopeptidases with broad substrate specificity and strictly regulated tissue specific expression. They are expressed in physiological situations and pathological conditions involving inflammation. MMPs regulate several functions related to inflammation including bioavailability and activity of inflammatory cytokines and chemokines. There is also evidence that MMPs regulate inflammation in tumor microenvironment, which plays an important role in cancer progression.

Scope of review

Here, we discuss the current view on the role of MMPs in the regulation of inflammation.

Major conclusions

MMPs modulate inflammation by regulating bioavailability and activity of cytokines, chemokines, and growth factors, as well as integrity of physical tissue barriers. MMPs are also involved in immune evasion of tumor cells and in regulation of inflammation in tumor microenvironment.

General significance

There is increasing evidence for non-matrix substrates of MMPs that are related to regulation of inflammatory processes. New methods have been employed for identification of the substrates of MMPs in inflammatory processes in vivo. Detailed information on the substrates of MMPs may offer more specific and effective ways of inhibiting MMP function by blocking the cleavage site in substrate or by inhibition of the bioactivity of the substrate. It is expected, that more precise information on the MMP–substrate interaction may offer novel strategies for therapeutic intervention in inflammatory diseases and cancer without blocking beneficial actions of MMPs. This article is part of a Special Issue entitled Matrix-mediated cell behaviour and properties.     

Immunologgical self-tolerance in allophenic and embryo-aggregated mice

Allophenic mice, supposedly containing almost equal numbers of cells derived from embryos of mouse strains C57Bl and FVB, were shown in a recent paper to grow the B16 melanoma, a long transplanted tumor of C57Bl origin, much better than did mice of either the parental C57Bl strain or the C57Bl × FVB F1 hybrid. Mice containing smaller proportions of C57Bl cells rejected the tumor. A reconsideration of these suprising data, in light of the current literature, suggests that the better growth of the tumor in the 50-50% allophenics than in the C57Bl parental strain was almost certainly caused by the tumor stimulation engendered by a weak anti-C57Bl immune reaction in the overtly healthy allophenic mice.     

Detection of bacterial contamination in starch and resin-based papermaking chemicals using fluorescence techniques

Rapid fluorescence techniques were evaluated for the detection of bacterial contaminants in papermaking chemicals including starch and the resin-based sizes and starch slurries used in the paper industry. Viable and non-viable bacterial cells were visualised by fluorescent probes and detected by epifluorescence microscopy and flow cytometry. The best discrimination ability was obtained with the fluorescent probes LIVE/DEAD and SYBR Green, based on the staining of cellular nucleic acid, and ChemChrome V3, which demonstrated cellular enzymatic activity. The process samples had to be diluted and filtered before fluorescence staining and analysis because they were viscous and contained solid particles. Fluorescence microscopic counts of bacteria in highly contaminated process samples were similar to plate counts, but flow cytometric enumeration of bacterial cells in process samples yielded 2- to 10-fold lower counts compared with plate counts, depending on the consistency of the sample. The detection limits in flow cytometric analysis and in epifluorescence microscopy were 10³–10⁶ cells ml⁻¹ and 10⁵–10⁶ cells ml⁻¹, respectively. Intrinsic bacterial contamination was detectable with fluorescence techniques and highly contaminated process samples could be analysed with fluorescence methods. Electronic Publication     

Automated detection of remote homology

The classification of a newly identified protein as a member of a superfamily is important for focusing experiments on its most likely functions. Such classification, often performed by hand, has now been fully automated. This sophisticated new approach takes into account not only alignment scores but also a number of other computable attributes, such as functional sites deduced from sequence conservation patterns.