IL-1 beta and TNF alpha modulate delta 9-tetrahydrocannabinol-induced catalepsy in mice

The role of the proinflammatory cytokines interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF alpha) in THC-induced catalepsy in mice was examined. Recombinant IL-1 beta (400 ng/mouse, IV) and TNF alpha (500 ng/mouse, IV) were effective in potentiating the cataleptic effect of low-dose THC (10 micrograms/mouse, IV). Recombinant IL-1 alpha and IL-6 did not potentiate catalepsy at any dose tested. Anti-IL-1 beta and anti-TNF alpha antibodies were effective in attenuating high-dose (75 micrograms/mouse) THC-induced catalepsy. Antibodies to IL-1 alpha and IL-6 had no effect on catalepsy. Early onset catalepsy (10 min postinjection) was potentiated by exogenous recombinant IL-1 beta and TNF alpha but only later catalepsy (2 h postinjection) was attenuated by antibodies to endogenous IL-1 beta or TNF alpha. This divergence of the cytokine effect suggests that these substances regulate, by different mechanisms, the early and late THC-induced cataleptic response.     

Life table study of Aedes aegypti (Diptera: Culicidae) in Puerto Rico fed only human blood versus blood plus sugar

Life table studies were performed in 1996 with Aedes aegypti (L.) during the low (cool/dry) and high (hot/rainy) dengue virus transmission seasons in Puerto Rico. Mated adult females from field-collected pupae were placed individually in cages and divided into 2 treatment groups: one was fed only human blood and the other human blood plus a 10% sucrose solution. Survival and number of eggs laid were recorded daily for each female. During both seasons, age specific survivorship was higher for the blood plus sugar group, groups fed only human blood had higher reproductive outputs (mx), and net replacement rates (Ro) for blood only groups were higher than for those fed blood plus sugar. Intrinsic rates of growth (r) were the same for both treatments during the low (cool/dry) transmission season, but higher for the blood-only treatment during the high (hot/rainy) transmission season. Our results indicate that feeding on only human blood provides an evolutionary advantage to Ae. aegypti females in Puerto Rico. These results are similar to those from an earlier study carried out with Ae. aegypti in Thailand; the advantage of feeding on human blood does not seem to be restricted to a particular geographic region. We also found that the benefits associated with human feeding persist through epidemiologically different times of the year. We conclude that feeding on human blood is reproductively beneficial for Ae. aegypti, which may increase their contact with human hosts, and therefore may influence their vectorial capacity for dengue viruses through frequent feeding on blood.     

Cine magnetic resonance imaging of pulsatile cerebrospinal fluid flow using CSPAMM

Spatial modulation of magnetization (SPAMM) is a well established imaging technique which superimposes a tagging pattern on conventional magnetic resonance (MR) images, allowing movement to be visualized. A modification to the SPAMM technique, called complementary spatial modulation of magnetization (CSPAMM), which improves the contrast of the tagging pattern is explained. The application of CSPAMM to the visualization of pulsatile cerebrospinal fluid flow (CSF) using an 8 frame cardiac-gated cine sequence is described. Various combinations of binomial pulses, up to the fifth order, were investigated to see which produces the optimum tagging pattern in the CSPAMM images. The flip angles of the imaging RF pulses were studied to see which would give equal maximum CSF signal intensity in all the cine images. The optimized cine CSPAMM technique was compared in vivo with SPAMM and CSF motion was found to be more easily visualized in the CSPAMM images.     

Failure of Ixodes ticks to inherit Borrelia afzelii infection

To define conditions promoting inherited infection by Lyme disease spirochetes in Ixodes ticks, we variously infected ticks with Borrelia afzelii and examined their progenies by dark-field microscopy, immunofluorescence, PCR, and serial passage. No episode of inherited infection was evident, regardless of instar or gender infected or frequency of exposure. We suggest that these spirochetes rarely, if ever, are inherited by vector ticks.     

Antimetabolite-induced increases in the invasive capacity of murine leukaemia L1210 cells

Pretreatment of murine leukaemia L1210 cells with non-lethal concentrations of various antimetabolites increased the in vitro invasive capacity of these cells into monolayers of rat embryo fibroblasts. The increase in invasive capacity was partly correlated with the induced cell cycle arrest. The concomitant increase in cell surface fucosylation and inhibition of invasion with sulphate indicate a role for glycoproteins in this process. Our results suggest that treatment with antimetabolites may lead to a more aggressive phenotype by altering cell surface properties.     

Transmembrane passage of cytokine-inducing bacterial products across new and reprocessed polysulfone dialyzers

The widespread use of bicarbonate dialysate and reprocessed high-efficiency and "high-flux" dialyzers has raised concerns about the increased risk of reverse-transfer of dialysate contaminants into the blood compartment. To evaluate this concern, the reverse-transfer of bacterial products from contaminated bicarbonate dialysate into the blood compartment was compared during in vitro dialysis with new or reprocessed high-flux polysulfone dialyzers. In vitro dialysis was carried out at 37 degrees C by use of a counter-current recirculating loop dialysis circuit with either new high-flux polysulfone dialyzers or dialyzers reprocessed once or 20 times with formaldehyde (0.75%) and bleach (< 1%) with an automated system. Heparinized whole blood from healthy volunteers was circulated through the blood compartment, and bicarbonate dialysate was circulated in the dialysate compartment. The dialysate was challenged sequentially by 1:1000 and 1:100 dilutions of a sterile Pseudomonas aeruginosa culture supernatant (bacterial challenge). Samples were drawn from the blood and dialysate compartments 1 h after each challenge. Peripheral blood mononuclear cells (PBMC) were harvested by Ficoll-Hypaque separation from whole blood in the blood compartment and a 5 x 10(6) PBMC/mL cell suspension was prepared. Likewise, dialysate samples (0.5 mL) were added to 0.5 mL suspension of 5 x 10(6) PBMC/mL drawn at baseline. All PBMC suspensions were incubated upright in a humidified atmosphere at 37 degrees C with 5% CO2 for 24 h, and total interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF alpha) cytokine production (cell-associated and secreted) was measured by radioimmunoassay. Eight experiments were performed for each arm of the study with the same donor for each arm. One hour after contaminating the dialysate with a 1:1000 dilution of the bacterial challenge, IL-1 alpha production by PBMC harvested from the blood compartment was 160 +/- 0, 171 +/- 11, and 270 +/- 35 pg, respectively, for new dialyzers, dialyzers reprocessed once, and dialyzers reprocessed 20 times (P = 0.004). One hour after challenging the dialysate with 1:100 dilution, IL-1 alpha production by PBMC harvested from the blood compartment was 188 +/- 20, 228 +/- 35, and 427 +/- 67 pg, respectively, for new dialyzers, dialyzers reprocessed once, and dialyzers reprocessed 20 times (P = 0.006). IL-1 alpha production by PBMC from dialyzers reprocessed 20 times was significantly greater than both new and dialyzers reprocessed once. However, there were no significant differences between new dialyzers and dialyzers reprocessed once. Similarly, after the 1:1000 challenge, TNF alpha production by PBMC harvested from the blood compartment was 160 +/- 0, 160 +/- 0, and 213 +/- 22 pg, respectively, for new dialyzers, dialyzers reprocessed once, and dialyzers reprocessed 20 times (P = 0.008). After the 1:100 challenge, TNF alpha production was 168 +/- 8, 188 +/- 20, and 225 +/- 32 pg, respectively, for new dialyzers, dialyzers reprocessed once, and dialyzers reprocessed 20 times (P = 0.20). These results demonstrate that reprocessing of high-flux polysulfone dialyzers with bleach increases the risk of reverse-transfer of bacterial products from contaminated dialysate, and this risk appears to increase with the number of reuses. Consequently, units that reprocess membranes with bleach and have suboptimal water quality might subject their patients to a higher risk of cytokine-related morbidity.     

Two methods of natural family planning

I read with interest the recent article by Wade and associates, "A randomized prospective study of the use-effectiveness of 2 methods of natural family planning: an interim report" (134: 628, 1979). In reference to the study of the ovulation method, the authors noted that abstinence begins on the 1st day of mucus secretion and continues until the evening of the 4th day beyond the peak or maximal mucus secretion. In the ovulation method, the peak symptom is not the same as maximal mucus secretion as was indicated in the paper. The peak symptom is defined as the last day of the mucus discharge that is clear and/or stretchy and/or lubricative. In the definition of peak symptom, the amount of mucus discharge is not specifically important and may often be misleading. I had the opportunity to do a site visit at this study at the request of the National Institutes of Health while the study was in progress. I analyzed several pregnancies which occurred in users of this ovulation method. Some of the pregnancies occurred as the result of poor teaching of the concept of peak symptom. In the ovulation method, proper understanding and teaching of that concept are essential to the measurement of its effectiveness. Noticeably missing from this interim report was any discussion of the quality control procedures which were utilized to guarantee a high-quality educational service to the people entered into the study. While the authors claim that the methods were taught by professional teachers, these teachers were actually women who had previously used the method and/or had formalized training in teaching the method. Simple use of either of the methods certainly does not qualify an individual to teach natural family planning. For those with formalized teaching, such training should have been outlined since judgment on the effectiveness of the teaching cannot be made; such a judgment is essential to the proper analysis of results. Finally, while the study claims to be a use-effectiveness study, it is rather a modified version of extended use-effectiveness. No objective definition of "user failure" is provided. One cannot ascertain how many pregnancies were related to poor teaching, nor can one tell how many occurred as the result of the couples' last minute exercise of their freedom to use their fertility. The use-effectiveness of the 2 methods under study as a means to achieve a pregnancy have been ignored. In doing so, the investigators have ignored use-effectiveness reality.     

Relationship between a behavioral and several psychometric measures of test anxiety

Behavioral time-sampling was compared with various paper-and-pencil, self-report measures of test anxiety in an examination of the utility of the behavioral measure as an in situo index of test anxiety. The behavioral measure was significantly and positively correlated 0.45 with a paper-and pencil, self-report measure of "facilitative" test anxiety but not with measures of "debilitative" test anxiety (r = -0.15) or general anxiety (r = -0.33) for 12 males and 21 female undergraduates.     

Storage stability of poultry fat and diesel fuel mixtures: Part II - Chemical properties

This publication continues previously published work from the authors which evaluates the storage potential of poultry fat for its use as an unmodified biofuel in heat and steam generating systems [1]. The previous work examined the physical properties of these fats while this study is concerned with chemical properties. In this study poultry fat (biofuel) and its 20%, 40%, 60% and 80% mixtures with #2 pump diesel fuel were stored for 1 year at bench scale (1L) under controlled laboratory conditions at 4, 38, 54.4 °C and at 22 °C. One hundred percent of poultry fat was studied under these same conditions with and without an antioxidant additive. Twenty and eighty percent of poultry fat mixtures were also stored at pilot scale (250 gallons) under outdoor, ambient conditions. Chemical properties relevant to the use of these mixtures as a biofuel for industrial boilers were studied and tracked. These properties include Energy Values (BTU), Ultimate Analysis (carbon, hydrogen, oxygen, ash, nitrogen, and sulfur), moisture, impurities, unsaponafiables (MIU), and Free Fatty Acid Content. Energy content of the biofuel samples dropped over the course of the study with untreated biofuel losing 18.9% of its BTU value over the course of a year. Ultimate analyses showed an overall increase in carbon composition and a decrease in oxygen content. Hydrogen levels increased in most treatments as did overall ash and sulfur percent composition. MIU values increased, this overall increase was attributable to variable increases in insolubles and unsaponifiables. Free fatty acid levels increased in all treatments. Most of the chemical changes observed in this study were reduced by the addition of antioxidant to 100% biofuel.     

Respiratory symptoms and pulmonary function in coal miners: looking into the effects of simple pneumoconiosis

Most soil quality guidelines do not distinguish among the various forms of metals in soils; insoluble, nonreactive, and nonbioavailable forms are deemed as hazardous as highly soluble, reactive, and toxic forms. The objective of this study was to better understand the long-term effects of copper on microorganisms in relation to its chemical speciation in the soil environment. Carbon mineralization processes and the global structure of different microbial communities (fungi, eubacteria, actinomycetes) are still affected after more than 50 years of copper contamination in 20 soils sampled from two different agricultural sites. The microbial respiration lag period (LP) preceding the beginning of mineralization process increases with the level of soil copper contamination and is not significantly affected by other environmental factors such as soil pH and soil organic matter (SOM) content. The total copper concentration showed the best correlation with the LP when each site is considered separately. However, when considering the whole set of data, soil solution free Cu2+ activity (pCu2+) is the best predictor of Cu toxicity determined by LP (quite likely because pCu2+ integrates the soil physicochemical variability). The maximum mineralization rate (MMR), even if well correlated with the pCu2+, appears not to be a good biomonitor of copper contamination in soils since it is highly sensitive to soil characteristics such as SOM content. This study emphasizes the importance of the physicochemical properties of the environment on soil heavy metal toxicity and on soil toxicological measurements. These properties must be characterized in soil toxicological studies with respect to (1) their interactions with heavy metals, and (2) their direct impact on the selected biological test. The measurement of pCu2+ to characterize the level of soil contamination and of lag period as a bioindicator of metal effects in the soil are recognized as useful tools for the evaluation of the biological quality of soils.