Reactive knee stiffening strategies between various conditioning histories.

Optimizing joint stiffness through appropriate muscular activation is crucial for maintaining stability and preventing injury. Conditioning techniques may affect joint stability by increasing joint stiffness and altering neuromuscular control; however no studies have assessed this in a controlled setting. Fifteen endurance athletes, 12 power athletes, and 15 control subjects sat on a stiffness device that generated a rapid knee flexion perturbation and were instructed to react to the perturbation. Main outcome measures included short-range (0-4°) and long range (0-40°) stiffness and muscle activation from quadriceps and hamstring muscles. Stiffness results revealed greater short-range stiffness in endurance athletes (0.057 ± 0.012 Nm/deg/kg) than controls (0.047 ± 0.008 Nm/deg/kg, p = 0.021); while passive long-range stiffness was greater in power (0.0020 ± 0.001 nm/deg/kg) than endurance athletes (0.0016 ± 0.001 nm/deg/kg, p = 0.016). Endurance athletes had greater reactive stiffness (0.051 ± 0.017 nm/deg/kg) than control (0.033 ± 0.011 nm/deg/kg, p = 0.001) and power (0.037 ± 0.015 nm/deg/kg, p = 0.044) groups. Endurance athletes also displayed greater quadriceps activity during passive and reactive conditions (p < 0.050) compared to power athletes and controls. These findings suggest that power-based training history may be associated with greater passive joint stiffness across the full range of motion, while endurance-based training could positively influence reactive muscular characteristics, as well as resting muscle tone. These unique variations in stiffness regulation could be beneficial to programmes for prevention and rehabilitation of joint injury.

Two- and 3-dimensional knee valgus are reduced after an exercise intervention in young adults with demonstrable valgus during squatting.

CONTEXT: Two-dimensional (or medial knee displacement [MKD]) and 3-dimensional (3D) knee valgus are theorized to contribute to anterior cruciate ligament injuries. However, whether these displacements can be improved in the double-legged squat (DLS) after an exercise intervention is unclear. OBJECTIVE: To determine if MKD and 3D knee valgus are improved in a DLS after an exercise intervention. DESIGN: Randomized controlled clinical trial. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 32 participants were enrolled in this study and were randomly assigned to the control (n = 16) or intervention (n = 16) group. During a DLS, all participants demonstrated knee valgus that was corrected with a heel lift. INTERVENTION(S): The intervention group completed 10 sessions of directed exercise that focused on hip and ankle strength and flexibility over a 2- to 3-week period. MAIN OUTCOME MEASURE(S): We assessed MKD and 3D knee valgus during the DLS using an electromagnetic tracking system. Hip strength and ankle-dorsiflexion range of motion were measured. Change scores were calculated for MKD and 3D valgus at 0%, 10%, 20%, 30%, 40%, and 50% phases, and group (2 levels)-by phase (6 levels) repeated-measures analyses of variance were conducted. Independent t tests were used to compare change scores in other variables (α < .05). RESULTS: The MKD decreased from 20% to 50% of the DLS (P = .02) and 3D knee valgus improved from 30% to 50% of the squat phase (P = .001). Ankle-dorsiflexion range of motion (knee extended) increased in the intervention group (P = .009). No other significant findings were observed (P > .05). CONCLUSIONS: The intervention reduced MKD and 3D knee valgus during a DLS. The intervention also increased ankle range of motion. Our inclusion criteria might have limited our ability to observe changes in hip strength.

First observation of Elaeophora schneideri Wehr and Dikmans, 1935 (Nematoda:Filariidae) in mule deer from Nebraska.

Between November 2000 and November 2005, approximately 200 mule deer (Odocoileus hemionus hemionus) and white-tailed deer (Odocoileus virginianus) from western Nebraska were extensively examined for the presence of Elaeophora schneideri, Wehr and Dikmans, 1935; three adult E. schneideri were detected from three mule deer. This represents the first documented occurrence of E. schneideri from wild deer in Nebraska.

Observation of the nonlinear meissner effect in YBCO thin films: evidence for a D-wave order parameter in the bulk of the cuprate superconductors.

We present experimental evidence for the observation of the nonlinear Meissner effect in high-quality epitaxial yttrium barium copper oxide thin films by measuring their intermodulation distortion at microwave frequencies versus temperature. Most of the films measured show a characteristic increase in nonlinearity at low temperatures as predicted by the nonlinear Meissner effect. We could measure the nonlinear Meissner effect because intermodulation distortion measurements are an extremely sensitive method that can detect changes in the penetration depth of the order of 1 part in 10(5).

Detection of isolated tumor cells in peripheral blood and in BM: evaluation of a new enrichment method.

Cell enrichment methods that deal with larger volumes of peripheral blood and BM are needed for increased sensitivity of detection, characterization and quantification of isolated tumor cells (ITC). This study was designed to evaluate a new procedure, the RosetteSep-Applied Imaging Rare Event (RARE) detection method, which depletes the majority of the erythrocytes and leucocytes in a peripheral blood (PB) sample, thereby negatively enriching tumor cells if present. This enrichment procedure allows for increased sensitivity, by analyzing a 5-10 fold larger volume of blood, compared with a direct immunocytochemical (ICC) technique, with minimal impact on laboratory workload. Model experiments showed comparable tumor cell recoveries between the two tested methods, both in PB and BM. Clinical samples were evaluated using paired PB and BM samples from 95 carcinoma patients. Analysis of PB results showed that 25.3% had > or = 1 tumor cell detected by the RARE procedure, compared with 5.2% after direct ICC analysis, analyzing a 10-fold larger volume by the RARE procedure. The direct ICC analysis of BM from the same patients revealed 16.8% positive. The ITC detection differed both quantitatively and qualitatively between BM and PB, as samples with high numbers of ITC in BM were still negative in PB. The clinical significance of ITC in blood still needs to be established. However, the easy access of peripheral blood, and the increased sensitivity obtained by increasing the sample volume with the RARE procedure, suggests that the value of peripheral blood analysis should be tested in parallel in studies where ITC detection in BM is performed.

Meningeal worm in deer from western Nebraska.

One hundred seventy-eight white-tailed deer (Odocoileus virginianus) and 275 mule deer (Odocoileus hemionus) collected from locker plants in the western 2/3 of Nebraska (USA) in November 1997 were examined for the meningeal worm (Parelaphostrongylus tenuis). Parelaphostrongylus tenuis was identified in 17 (10%) of 168 white-tailed deer and in one (<1%) of 273 mule deer. This is the first naturally occurring infection of P. tenuis recorded in a mule deer.

Meningeal worm in free-ranging deer in Nebraska.

The meningeal worm (Parelaphostrongylus tenuis) was found in 22 (7%) of 300 white-tailed deer (Odocoileus virginianus) (257 adults, 43 fawns) examined from Nebraska (USA) during November 1996. None of 53 mule deer (Odocoileus hemionus) (47 adults and 6 fawns) examined were infected. Twenty-two white-tailed deer from 18 counties in eastern Nebraska were infected with Parelaphostrongylus tenuis. This is the first record of P. tenuis in white-tailed deer from this state.

Absence of tuberculosis in free-ranging deer in Nebraska.

Lymph nodes from 271 white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus) in Nebraska (USA) were examined microscopically for tuberculoid lesions. Lymph nodes lesions in at least one node were found in 12 deer. Lesions were examined with Zeihl-Neelson acid fast stains and by polymerase chain reactions using M. bovis specific probes. No evidence of tuberculosis was found. The small granulomatous lesions were likely caused by other bacteria.

Suspiciousness, mental simulation, and norm theory.

Seven studies were conducted to replicate the work of Miller, Turnbull, and McFarland (1989), who tested predictions from norm theory (Kahneman & Miller, 1986). The first three studies with stimulus materials identical to those used by Miller et al. failed to confirm that the ease with which the event might be mentally simulated affected the degree of suspiciousness. In Studies 4, 5, and 6, the improbable events were made objectively more probable, but this did not produce significant results. In the 7th study, the objective probability and attitude toward the target were varied. Although there was a main effect for ease of mental simulation, this effect was produced by only 1 of the 3 vignettes.

Cockayne's syndrome fibroblasts are characterized by hypersensitivity to deoxyguanosine and abnormal DNA precursor pool metabolism in response to deoxyguanosine or ultraviolet light.

New cellular traits of Cockayne's syndrome (CS) associated with DNA precursor metabolism have been identified, namely, hypersensitivity to the toxicity of low concentrations of deoxyguanosine (dG) and abnormal changes in deoxyribonucleotide (dNTP) pools in response to dG or UV. dG treatment results in similar ribonucleotide pool changes in wild-type and CS cells, i.e., GTP levels increase at least twofold. However, the changes in the pool size of the purine deoxyribonucleotides are significantly different; in wild-type cells dATP and dGTP pools increase threefold, but remain unchanged in CS. The mechanism by which dG kills CS cells is not clear, but unlike the inherited purine nucleoside phosphorylase deficiency disease, the toxicity of dG is not due to the accumulation of dGTP and the consequent feedback inhibition of ribonucleotide reductase. UV induces different dNTP pool changes in CS and wild-type cells. In wild-type cells dTTP, dCTP, and dATP pools increase three- to fivefold within 4 h of irradiation, while the dGTP pool contracts. In CS cells, only the dGTP pool expands (four- to sixfold), while the other three contract. Each of these new phenotypic traits, together with UV sensitivity, is coordinately corrected in the complementing proliferating CSA x CSB hybrid cells.

Bandage contact lens augmentation of 5-fluorouracil treatment in glaucoma filtration surgery.

The use of 5-Fluorouracil (5-FU) to inhibit scarring following filtration surgery has been hampered by corneal epithelial defects and their accompanying inflammation. This toxicity, which occurs during the crucial period in which the risk of bleb failure is highest, has previously been a relative contraindication to further 5-FU use. We have found the early placement of a therapeutic bandage contact lens permits extended administration of 5-FU during this period, minimizing discomfort and inflammation as well as enhancing bleb survival.

Anti-sense phosphorothioate oligonucleotides have both specific and non-specific effects on cells containing human papillomavirus type 16.

A range of specific nuclease resistant phosphorothioate oligodeoxynucleotides (S-oligos) complementary to mRNA of human papillomavirus type 16 (HPV16), were tested for their ability to inhibit cell proliferation and to alter the level of HPV-specific mRNA and proteins in CaSki cells, a human cervical carcinoma cell line containing HPV16 DNA. Only certain of the S-oligos to the viral upstream regulatory region (URR) and the early viral open reading frames (ORF), E6 and E7, were found to display any activity on the cells. These S-oligos were found to exhibit potent anti-proliferative activity at concentrations between 0.25 microM and 20 microM, inhibiting the uptake of [3H]-thymidine into CaSki cells by up to 90% at higher concentrations. The rate of synthesis of E6 and E7 proteins and the steady state level of the E7 protein however remained largely unchanged. E7 protein exhibited a greater decrease in phosphorylation in the presence of only one of the antisense oligos. Other S-oligos including a random sequence, unmodified sequences or O-methylphosphonate modified oligos, had no specific effect on the cells. The results imply that the anti-sense S-oligonucleotides had both specific anti-HPV16 and other non-specific effects on cell proliferation and synthesis of virally encoded proteins.

Ectoparasites of ring-necked pheasants in Nebraska.

In 1971, 1983 and 1984, ectoparasites were identified on 61 ring-necked pheasants (Phasianus colchicus) from Nebraska. Birds were collected throughout the state from 11 of 93 counties. Four species of chewing lice (Mallophaga) were collected: Lipeurus maculosus, Goniodes colchici, Lagopoecus colchicus and Amyrsidea megalosoma. One species of analgid mite, Megninia sp. was collected. Apparently, this species is new and undescribed. The four mallophagan species have not been reported from Nebraska.

High-sensitivity surface-photoacoustic spectroscopy.

The sensitivity of surface-acoustic-wave detection is extended by several orders of magnitude to a surface-specific absorbance of alphal ~ 10(-9) for a power density of 1 GW/cm(2) using a narrow-bandwidth interdigitated surface-acousticwave detector and an optical irradiation pattern to provide a matched acoustic signal. Major advantages include narrow-bandwidth detection and a large irradiated area that permits more optical energy on the sample. A rapid, nondestructive, reproducible liquid-bonding technique, which permits the extension of these measurements to a wide variety of samples, is demonstrated. Results for AlN and ZrO(2) films (alphal ~ 10(-4)) and fused-silica substrates (alphal ~ 10(-6)-10(-7)) are reported.

Microwave bulk-acoustic-wave reflection-grating resonators.

A technique for fabrication of bulk-acoustic-wave (BAW) resonators operating at fundamental frequencies between 1 and 10 GHz is presented. The resonators utilize a reflection grating made by optical holographic methods in iron-doped lithium niobate. Q factors of 30000 at 1 GHz have been demonstrated. Extension to Q of 10000 at 10 GHz appears feasible. Projected limitations to performance are discussed. The high Q at the high fundamental frequency directly results in low-phase noise. Phase-noise measurements of BAW resonator-stabilized oscillators operating at 1.14 GHz are presented. The single-sideband noise floor of <-140 dBc/Hz is shown to be in agreement with an analytical model. Projected improvements in the devices and circuits promise performance of <-160 dBc/Hz.

Hydroxyurea: effects on deoxyribonucleotide pool sizes correlated with effects on DNA repair in mammalian cells.

We have measured deoxyribonucleotide pool sizes in different cell types: normal human, transformed human (HeLa), and the permanent hamster line CHO-K1. The range of sizes of the four DNA precursor pools in CHO cells is far greater than in human cells. It is a general rule that hydroxyurea causes rapid depletion of pools (except for dTTP) until the pool present in smallest amount is exhausted; this suggests a tight coupling of the pools to DNA replication (the presumed main cause of the depletion). The effect of hydroxyurea on DNA repair after ultraviolet irradiation (namely, a relatively small accumulation of incomplete repair sites blocked at the resynthesis stage) is probably accounted for by the reduced availability of DNA precursors. However, depletion of the dCTP pool is not an adequate explanation for the observed enhancement by hydroxyurea of the inhibitory effect of cytosine arabinoside; we suggest other possible modes of action. Ultraviolet irradiation has only small effects on the levels of deoxyribonucleotides.

Prebirth prediction of the quality of the mother-infant interaction: the first year of life.

PIP: A predictive method involving the assessment of prebirth functioning and the anticipated quality of parenting is described and developed in order to facilitate identifications of family at risk for future parenting. The association between these predictions and selected outcome criteria was studied in a representative sample of 46 US families, who were followed from mid-pregnancy to infant age of 2 years. Both the quantitative and qualitative results support the hypotheses that those families where mother and father were both characterized during the prebirth assessments as above average on adaptation-competence, capacity for relationships, and their positive view of their marriage, and who were expected to provide an optimal parent care environment, did in fact enhance a mother-infant relationship charcterized by positive mutuality and responsiveness. The most efficient predictor of positive mother-infant mutuality was the father's positive experience of the marriage. The mother's verbal I.Q. correlates significantly with maternal adaptation-competence, which in turn correlates with positive mother-infant mutuality. It is assumed that the prebirth assessments and predictions, even though global in nature, effectively reflect a profile of family system and individual characteristics that are likely to enhance the development of positive mother-infant mutuality. The authors stress "enhance" because the characteristics of the infant, such as his or her irritability, are also going to influence the quality of the emerging transaction.^ieng

Biochemical genetics of Chinese hamster cell mutants with deviant purine metabolism: isolation and characterization of a mutant deficient in the activity of phosphoribosylaminoimidazole synthetase.

A new purine-requiring mutant of Chinese hamster ovary cells (CHO-Kl) is described. This mutant, Ade-G, grows on aminoimidazole carboxamide, hypoxanthine, or adenine. It complements all eight of our other previously described Ade- mutants. Biochemical analysis of de novo purine synthesis in whole cells suggests that Ade-G is capable of the first four reactions of de novo purine biosynthesis and that it synthesizes and accumulates phosphoribosylformylglycinamidine (FGAM). Direct enzyme assay in cell-free extracts confirms that Ade-G is defective in phosphoribosylaminoimidazole synthetase activity and does not convert FGAM to phosphoribosylaminoimidazole (AIR), the next intermediate in the de novo biosynthetic pathway.

Biochemical genetics of Chinese hamster cell mutants with deviant purine metabolism: characterization of Chinese hamster cell mutants defective in phosphoribosylpyrophosphate amidotransferase and phosphoribosylglycinamide synthetase and an examination of alternatives to the first step of purine biosynthesis.

Activities of the first three enzymes in the de novo purine biosynthetic pathway have been measured in cell-free extracts of the Chinese hamster ovary cell (CHO-K1) and two purine-requiring auxotrophs of this cell. Ade-A has been found to be defective in phosphoribosylpryophosphate (PRPP) amidotransferase while Ade-C has been found to be defective in glycinamide ribonucleotide (GAR) synthetase. Neither enzyme deficiency is due to the presence of an excess of diffusible inhibitor, and mixed extracts of Ade-A and Ade-C are capable of performing both enzymatic steps in a coupled assay. Assays of GAR formyltransferase show that it is present in Ade-A and Ade-C, indicating that these cell types are defective in only one enzyme each of the early purine biosynthetic enzymes. Using the Ade-A mutant, analysis of alternatives to PRPP plus glutamine as substrates for the first step in the purine biosynthetic pathway showed that a common genetic unit must direct the synthesis for both PRPP plus glutamine and PRPP plus ammonia activities. Although ribose-5-phosphate plus ammonia can be used in cell-free extracts to perform the first step in purine biosynthesis, it is shown that this activity is apparently not used by intact CHO-K1 cells.