ALGAL EXCRETION OF 14C-LABELED COMPOUNDS AND MICROBIAL INTERACTIONS IN CYANIDIUM CALDARIUM MATS1

Acid spring effluents are often covered with mats of the eucaryotic phycocyanin-containing alga. Cyanidium caldarium. The primary bacterial component of such mats is an acidophilic strain of Bacillus coagulans, and the primary fungal component is Dactylaria gallopava. Because of the limited species diversity, C. caldarium mats appeared to be an excellent system for studying algal excretion and various microbial interactions in nature. From 2 to 6% of the NaH¹⁴CO₃ taken up by natural or laboratory populations of the alga was excreted as ¹⁴C-labeled materials. The maximum excretion occurred at temperature, light, and pH values optimum for NaH¹⁴CO₃ uptake. However, when excretion was expressed as a percentage of NaH14 CO₃ uptake, a higher percentage of the radioactivity was excreted at nonoptimal conditions for NaH¹⁴CO₃ uptake. Fungal biomass was directly proportional to algal density, but bacterial numbers varied widely and did not correlate with algal numbers. The bacterial and fungal components could be grown in mixed culture with either growing C. caldarium cultures or in an extract prepared, by healing algal cells.     

EMG and EEG biofeedback training in the treatment of a 10-year-old hyperactive boy with a developmental reading disorder

The serial application of electromyographic (EMG) and sensorimotor (SMR) biofeedback training was attempted with a 10-year-old boy presenting a triad of symptoms: an attention deficit disorder with hyperactivity, developmental reading disorder, and ocular instability. Symptom elimination was achieved, for all three aspects of the triad, following the procedure of first conditioning a decrease in EMG-monitored muscle tension and then conditioning increases in the amplitude of sensorimotor rhythm over the Rolandic cortex. The learned reduction of monitored EMG levels was accompanied by a reduction in the child's motoric activity level to below that which had been achieved by past administration of Ritalin. In addition, the attention deficit disorder with hyperactivity was no longer diagnosable following the EMG biofeedback training. The learned increase in the amplitude of monitored SMR was accompanied by remediation of the developmental reading disorder and the ocular instability. These results remained unchanged, as ascertained by follow-ups conducted over a 24-month period subsequent to the termination of biofeedback training.     

Expression of carbonic anhydrase II mRNA and protein in oligodendrocytes during toxic demyelination in the young adult mouse

The aim of this study was to identify events that might take place in oligodendrocytes early in the process of demyelination, i.e., before the occurrence of massive loss of myelin. It was considered important to focus on demyelination and remyelination in young adults, in whose brains there would be relatively few juvenile glial precursor cells. CAII mRNA and protein were used to monitor changes in oligodendrocytes during cuprizone intoxication in the mice. After four or eight weeks of cuprizone feeding CAII message became less plentiful in oligodendrocyte processes. Two days after removal of cuprizone CAII message had appeared in those cell processes. Four or eight weeks after beginning cuprizone feeding CAII protein had decreased∼25% in forebrain homogenates. The loss of CAII protein was reversible after four weeks on cuprizone, but not after eight weeks. After four weeks of cuprizone feeding the numbers of CAII mRNA-prositive oligodendrocytes had decreased by ∼50%m and after eight weeks, by ∼80%. By 12 weeks, however, the number of oligodendrocytes expressing CAII mRNA had spontaneously returned to normal levels. Before eight weeks of cuprizone feeding, loss of myelinated tracts in the corpus striatum was reversible. Demyelination appreared to become irreversible after nine weeks of intoxication, although expression of CAII mRNA remained reversible. The results suggest that in the brain of the young adult, oligodendrocytes expressing message for CAII can be generated spontaneously shortly before demyelination becomes irreversible, and can survive and continue to express CAII mRNA but not CAII protein. Special issue dedicated to Dr. Marion E. Smith.     

Plant regeneration from stem and petal of carnation (Dianthus caryophyllus L.)

Plants were regenerated via adventitious shoot initiation from petal explants of carnation (Dianthus caryophyllus L.) cultivars Crowley Sim, Ember Rose, Orchid Beauty, Red Sim, White Sim and from stem segments of Crowley Sim, Red Sim, White Sim. Differences in cultivar response were observed, with White Sim being the most responsive for both explant types. Plants were also regenerated from receptacles of this cultivar. The effect of different cytokinins on regeneration from petal and stem explants of cultivar White Sim was compared. Thidiazuron was more effective than 6-benzylaminopurine or kinetin. In stem explants, morphogenic capacity was determined by the developmental stage of the explant. Highest percentage of shoot formation was observed in the youngest stem segments, on all the cytokinins tested. Stem-derived plants grew faster than petal or receptacle-derived plants and produced normal, flowering plants eight to ten months after culture.     

Teaching a new mouse old tricks: Humanized mice as an infection model for Variola virus

Smallpox, caused by the solely human pathogen Variola virus (VARV), was declared eradicated in 1980. While known VARV stocks are secure, smallpox remains a bioterrorist threat agent. Recent U.S. Food and Drug Administration approval of the first smallpox anti-viral (tecovirimat) therapeutic was a successful step forward in smallpox preparedness; however, orthopoxviruses can become resistant to treatment, suggesting a multi-therapeutic approach is necessary. Animal models are required for testing medical countermeasures (MCMs) and ideally MCMs are tested directly against the pathogen of interest. Since VARV only infects humans, a representative animal model for testing therapeutics directly against VARV remains a challenge. Here we show that three different humanized mice strains are highly susceptible to VARV infection, establishing the first small animal model using VARV. In comparison, the non-humanized, immunosuppressed background mouse was not susceptible to systemic VARV infection. Following an intranasal VARV challenge that mimics the natural route for human smallpox transmission, the virus spread systemically within the humanized mouse before mortality (~ 13 days post infection), similar to the time from exposure to symptom onset for ordinary human smallpox. Our identification of a permissive/representative VARV animal model can facilitate testing of MCMs in a manner consistent with their intended use.     

Flight activity and dispersal of the cabbage seedpod weevil (Coleoptera: Curculionidae) are related to atmospheric conditions

The cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham) (Coleoptera: Curculionidae), is an invasive pest of canola (Brassica napus L. and Brassica rapa L.) in western Canada. Under current climatic conditions, C. obstrictus is spreading from established populations in southwestern Alberta at ≈ 55 km/yr. We studied the influence of climatic conditions on C. obstrictus flight behavior in 2007 and 2008 and eastward dispersal from the western border of Saskatchewan from 2002 to 2007. Positive linear relationships between increases in mean temperature and flight height and between greater mean maximum temperature and expanded dispersal distances were significant. Increases in relative humidity were associated with reduced flight heights and dispersal distances. We developed models that predict the relationships of temperature and relative humidity with flight height and with dispersal distance. We also discuss implications for C. obstrictus dispersal under current climatic conditions and in the context of predicted climate change.     

Evaluation of a patient-specific cost function to predict the influence of foot path on the knee adduction torque during gait

A large external knee adduction torque during gait has been correlated with the progression of knee osteoarthritis (OA). Though foot path changes (e.g. toeing out) can reduce the adduction torque, no method currently exists to predict whether an optimal foot path exists for a specific patient. This study evaluates a patient-specific optimization cost function to predict how foot path changes influence both adduction torque peaks. Video motion and ground reaction data were collected from a patient with knee OA performing normal, toe out, and wide stance gait. Joint and inertial parameters in a dynamic, 27 degree-of-freedom, full-body gait model were calibrated to the patient's normal gait data. The model was then used in gait optimizations that predicted how the patient's adduction torque peaks would change due to changes in foot path. The cost function tracked the patient's normal gait data using weight factors calibrated to toe out gait and tested using wide stance gait. For both gait motions, the same cost function weights predicted the change in both adduction torque peaks to within 7% error. With further development, this approach may eventually permit the design of patient-specific rehabilitation procedures such as an optimal foot path for patients with knee OA.