RNA from LPS-stirnulated macrophages induces the release of tumour necrosis factor-alpha and interleukin-1 by resident macrophages

The effect of exogenous RNA on many cellular functions has been studied in a variety of eukaryotic cells but there are few reports on macrophages. In the present study, it is demonstrated that cytoplasmatic RNA extracted from rat macrophages stimulated with Escherichia coli lipopolysaccharide (LPS), referred to as L-RNA, induced the release of TNF-alpha and IL-1 from monolayers of peritoneal resident macrophages. The activity of L-RNA was not altered by polymyxin B but was abolished by ribonuclease (RNase) pretreatment, indicating the absence of LPS contamination and that the integrity of the polynucleotide chain is essential for this activity. Both the poly A(-) and poly A(+) fractions obtained from L-RNA applied to oligo(dT)-cellulose chromatography induced TNF-alpha and IL-1 release. The L-RNA-induced cytokine release was inhibited by dexamethasone and seemed to be dependent on protein synthesis since this effect was abolished by cycloheximide or actinomycin-D. The LPS-stimulated macrophages, when pre-incubated with [5-(3)H]-uridine, secreted a trichloroacetic acid (TCA) precipitable material which was sensitive to RNase and KOH hydrolysis, suggesting that the material is RNA. This substance was also released from macrophage monolayers stimulated with IL-1beta but not with TNF-alpha, IL-6 or IL-8. The substance secreted ((3)H-RNA) sediments in the 4-5S region of a 5-20% sucrose gradient. These results show that L-RNA induces cytokine secretion by macrophage monolayers and support the idea that, during inflammation, stimulated macrophages could release RNA which may further induce the release of cytokines by the resident cell population.     

Circadian Rhythm of Cardiac Output, Peripheral Vascular Resistance, and Related Variables by a Beat-to-Beat Monitoring

This study aimed to explore the 24-h patterns of stroke volume, cardiac output, and peripheral vascular resistance along with other correlated variables, such as left ventricular ejection time, ejection velocity index, thoracic fluid index, heart rate, and blood pressure. The study was performed on 12 clinically healthy subjects by means of a noninvasive beat-to-beat monitoring using the thoracic electric bioimpedance technique associated with the automated sphygmomano-metric recording. Time data series were analyzed by means of chronobiological procedures. The results documented the occurrence of a circadian rhythm for all the variables investigated, giving relevance to the beat-to-beat bioperiodicity of cardiac output and peripheral vascular resistance. Temporal quantification of the investigated variables may be useful for a better insight of the chronophysiology of the cardiovascular apparatus.     

Fibronectin turnover in human mesangial cell cultures as affected by Adriamycin

Fibronectin (FN) turnover and turnover changes induced by the anticancer drug Adriamycin (ADR) were measured in human mesangial cells (HMC) in vitro. HMC cultures synthesize cellular FN (2.2+-0.3% of totalprotein synthesis; n = 12) which is secreted and incorporated into a fibrillar extracellular matrix (ECM). A 24 hr incubation of HMC with ADR (0.5–5 g/ml) resulted in an accumulation of FN in the culture medium, with a maximum increase following 5 pglml(7.3+-2.3pg/cell vs. controls: 4.4+-1.9pg/cell; n= 10). Correspondingly, radioactively labeled immunoprecipitable FN was increased in a dosage-dependent manner in the culture medium up to 50% vs. controls. The incorporation of radioactively labeled FN into ECM was significantly increased following 2 g ADR/ml. In accordance, immunofZuorescence staining revealed an expansion ofpericellular FNfibers in cultures exposed to 2 g ADR/ml. Concomitant with the accumulation of extracelhlar FN, radioactively labeled FN in the cells was reduced by 22%. Qualitative characterization of FN patterns revealed a diminished number of degradation products in the culture medium ofADR-treated HMC. These data suggest thatADR interferes with the turnover of FN secreted by HMC in vitro in such a way that FN accumulates extracellularly. This in turn leads to a reduced FN synthesis. These findings are compatible with a loss of urinary FN degradation products accompanying the onset ofproteinuria in ADR-treated rats.Abbreviations ADR adriamycin - BSA bovine serum albumin - DTT dithiothreitol - ECM extracellular matrix - EDTA ethylenediamine tetraacetic acid disodium salt - ELISA enzyme-linked immunosorbent assay - FCS fetal calf serum - FITC fluorescein isothiocyanate - FN fibronectin - HMC human mesangial cell - PBS phosphate buffered saline - PMSF phenylmethylsulfonyl fluoride - SDS sodium dodecyl sulfate - SDS-PAGE SDS-polyacrylamide gel electrophoresis     

Odontocete spatial patterns and temporal drivers of detection at sites in the Hawaiian islands

Successful conservation and management of marine top predators rely on detailed documentation of spatiotemporal behavior. For cetacean species, this information is key to defining stocks, habitat use, and mitigating harmful interactions. Research focused on this goal is employing methodologies such as visual observations, tag data, and passive acoustic monitoring (PAM) data. However, many studies are temporally limited or focus on only one or few species. In this study, we make use of an existing long-term (2009–2019), labeled PAM data set to examine spatiotemporal patterning of at least 10 odontocete (toothed whale) species in the Hawaiian Islands using compositional analyses and modeling techniques. Species composition differs among considered sites, and this difference is robust to seasonal movement patterns. Temporally, hour of day was the most significant predictor of detection across species and sites, followed by season, though patterns differed among species. We describe long-term trends in species detection at one site and note that they are markedly similar for many species. These trends may be related to long-term, underlying oceanographic cycles that will be the focus of future study. We demonstrate the variability of temporal patterns even at relatively close sites, which may imply that wide-ranging models of species presence are missing key fine-scale movement patterns. Documented seasonal differences in detection also highlights the importance of considering season in survey design both regionally and elsewhere. We emphasize the utility of long-term, continuous monitoring in highlighting temporal patterns that may relate to underlying climatic states and help us predict responses to climate change. We conclude that long-term PAM records are a valuable resource for documenting spatiotemporal patterns and can contribute many insights into the lives of top predators, even in highly studied regions such as the Hawaiian Islands.     

Effects of anti-inflammatory drugs on fever and neutrophilia induced by Clostridium difficile toxin B

This study investigated the ability of Clostridium difficile toxin B, isolated from the VPI 10463 strain, to induce fever and neutrophilia in rats. Intravenous injection of toxin B (0.005-0.5 mug/kg) evoked a dose-dependent increase in body temperature. The febrile response to 0.5 mug/kg of the toxin started in 2.5 h, peaked at 5 h, and subsided fully within 24 h. Toxin B also induced a dosedependent neutrophilia. Pretreatment with indomethacin (2 mg/kg, i.p.) did not affect the neutrophilia induced by toxin B, but significantly reduced the febrile response measured 4 to 8 h after toxin B injection. Dexamethasone (0.5 mg/ kg) also markedly diminished the febrile response induced by toxin B. These results show that Clostridium difficile toxin B induced a febrile response susceptible to inhibition by dexamethasone and indomethacin. Furthermore, they suggest that prostaglandins are not involved in the neutrophilia caused by this toxin.     

Characterization of an Escherichia coli mutant, feeA, displaying resistance to the calmodulin inhibitor 48/80 and reduced expression of the rare tRNA3Leu

We previously described a mutation feeB1 conferring a temperature-sensitive filamentation phenotype and resistance to the calmodulin inhibitor 48/80 in Escherichia coli, which constitutes a single base change in the acceptor stem of the rare tRNA₃^Leu recognizing CUA codons. We now describe a second mutant, feeA1, unlinked to feeB, but displaying a similar phenotype, 48/80 resistance and a reduced growth rate at the permissive temperature, 30°C, and temperature-sensitive, forming short filaments at 42°C. In the feeA mutant, tRNA₃^Leu expression (but not that of tRNA₁^Leu) was reduced approximately fivefold relative to the wild type. We previously showed that the synthesis of β-galactosidase, which unusually requires the translation of 6-CUA codons, was substantially reduced, particularly at 42°C, in feeB mutants. The feeA mutant also shows drastically reduced synthesis of β-galactosidase at the non-permissive temperature and reduced levels even at the permissive temperature. We also show that increased copy numbers of the abundant tRNA₁^Leu, which can also read CUA codons at low efficiency, suppressed the effects of feeA1 under some conditions, providing further evidence that the mutant was deficient in CUA translation. This, and the previous study, demonstrates that mutations which either reduce the activity of tRNA₃^Leu or the cellular amount of tRNA₃^Leu confer resistance to the drug 48/80, with concomitant inhibition of cell division at 42°C.     

Psychosocial Concerns and Health-Compromising Behaviors among Overweight and Nonoverweight Adolescents

Objective: To compare weight-specific and global psychosocial concerns and health-compromising behaviors among overweight and nonoverweight youth across gender and ethnicity. Methods: A cross-sectional school-based survey of 31,122 adolescents in grades 7 to 12. Based on self-reported heights and weights, respondents were categorized as nonoverweight (body mass index (BMI) <85th percentile), moderately overweight (85th percenile <BMI <95th percentile), or severely overweight (BMI >95th percentile). Results: Global psychosocial concerns, such as emotional well-being, suicidal ideation, future job concerns, and peer concerns, did not differ greatly between nonoverweight, moderately overweight, and severely overweight adolescents. Substance abuse behaviors were equally or less prevalent among the overweight group. Overweight girls were significantly less likely to consume alcohol, whereas overweight boys were at lower risk for marijuana use. In contrast, overweight youth were more likely to perceive their health as only fair or poor and were more likely to express weight-specific concerns and engage in behaviors such as chronic dieting and binge eating than nonoverweight youth. Overweight American Indian girls perceived their physical health more positively than nonoverweight American Indian girls. Strong associations were found between overweight status and chronic dieting among African American boys and girls. Conclusions: Nutritional counseling and educational programs need to address the weight-specific concerns and behaviors of overweight adolescents. However, assumptions regarding global psychosocial concerns and health-compromising behaviors among overweight adolescents of different genders and ethnicities should be avoided. These broad issues need to be explored in more depth at both the research and intervention levels.     

Catecholamine and MHPG plasma levels,platelet MAO activity,and3H-imipramine binding in heroin and cocaine addicts

This work evaluated in a population of heroin and heroin plus cocaine human addicts:

1. Norepinephrine (NE), epinephrine (Epi), and 3-methoxy-4-hydroxyphenylglycol (MHPG) (the principal metabolite of brain NE) plasma levels;
2. Monoamine oxidase (MAO) activity; and
3. ³H-imipramine specific binding to the amine carrier in platelets.

NE plasma levels were significantly lower in the short-term heroin user groups (1–3 and 4–6 yr), a finding not observed in both the long-term heroin user (>6 yr) and heroin plus cocaine user (>6 yr) groups. Epi levels changed in a similar manner, except that a significant increase was noted in heroin plus cocaine abusers. Conversely, dopamine and MHPG plasma levels increased with the duration of heroin use, and even more with cocaine abuse. Platelet MAO activity increased in all groups. Specific³H-imipramine binding sites showed an increase after 3 yr of heroin abuse and in all heroin plus cocaine addicts. In conclusion, short-term use of heroin decreases NE or Epi release, but with prolonged use, a slow adpatation occurs. In contrast, cocaine inhibits the neuronal Epi uptake, even in a situation of long duration of abuse. Probably the amine levels additionally regulate the amine carrier, resulting in changes that show a different pattern from major depression. These drugs of abuse may also influence directly or indirectly related enzymatic systems.     

A High-Resolution Interval Map of the q21 Region of the Human X Chromosome

In a previous study, we have developed a panel of chromosomal rearrangements for the physical mapping of the q13-q21 region of the human X chromosome (Philippe et al., Genomics 17: 147-152, 1993). Here, we report the physical localization of 36 additional polymorphic markers by polymerase chain reaction analysis. The high density of chromosomal breakpoints in Xq21 allows us to map 58 DNA loci in 22 intervals. As a result, this segment of the X chromosome is saturated with approximately three sequence tagged sites per megabase of DNA, which will facilitate the construction of a YAC contig of this region.