Microbial elicitors induce activation and dual phosphorylation of the Arabidopsis thaliana MAPK 6

Protein kinases related to the family of mitogen-activated kinases (MAPKs) have been established as signal transduction components in a variety of processes in plants. For Arabidopsis thaliana, however, although one of the genetically best studied plant species, biochemical data on activation of mitogen-activated protein kinases are lacking. A. thaliana MAPK 6 (AtMPK6) is the Arabidopsis orthologue of a tobacco MAPK termed salicylate-induced protein kinase, which is activated by general and race-specific elicitors as well as by physical stress. Using a C terminus-specific antibody, we show that AtMPK6 is activated in elicitor-treated cell cultures of A. thaliana. Four different elicitors from bacteria, fungi, and plants lead to a rapid and transient activation of AtMPK6, indicating a conserved signaling pathway. The induction was equally rapid as medium alkalinization, one of the earliest elicitor response observed in cell cultures. A similarly rapid activation of AtMPK6 was observed in elicitor-treated leaf strips, demonstrating that recognition of the elicitors and activation of the MAPK pathway occurs also in intact plants. We demonstrate by in vivo labeling that AtMPK6 is phosphorylated on threonine and tyrosine residues in elicited cells.

Selected aspects of the art and science of facial esthetics

The historical aspects of facial esthetics and its role in orthodontic teachings and practice are traced to their origins in classical art. Related discussions include the failure of "divine proportions," the ascent of the Class II facies, and the influence of 19th century pseudoscience. Today, the treatment of facial form for a diverse society requires a tolerant sense of esthetic pluralism. Moreover, advances in neuroscience and psychology have extended understanding of the biological basis of variation in facial expression and judgment. The nature of oral esthetics was examined through quantitative studies of the smile line. Significant sexual dimorphism was found, ie, the gingival smile line (GSL) appears to be a female lineament and the low smile line seems to be a male lineament. Further results indicated that the GSL is associated with several facial characteristics, including anterior vertical maxillary excess, and the muscular capacity to raise the upper lip significantly higher than average on smiling. Other variables associated with GSL are statistically significant increases in overjet, interlabial gap at rest, and overbite. The gingival smile line is not necessarily objectionable esthetically and it will normally diminish with age. However, the treatment of choice for the GSL patient with an uncoached complaint is orthognathic surgery and orthodontics.

Classification of maxillary tooth transpositions

Tooth transposition is a severe disturbance of tooth order and eruptive position, involving certain teeth, that may occur at any of several specific sites in the mouth. Published cases of transposition involving maxillary teeth were gathered from worldwide sources to study, identify, and classify these occurrences of orthodontic interest. With a sample of 201 cases and on the basis of anatomic factors, five types of maxillary tooth transpositions were discerned: canine--first premolar (Mx.C.P1), 143 cases; canine--lateral incisor (Mx.C.I2), 40 cases; canine to first molar site (Mx.C to M1), 8 cases; lateral incisor--central incisor (Mx.I2.I1), 6 cases; and canine to central incisor site (Mx.C to I1), 4 cases. As a benefit from this large-scaled study of an uncommon anomaly, new analyses are presented on cause and treatment aspects for each of these five classes of maxillary tooth transpositions.

Prevalence of tooth agenesis and peg-shaped maxillary lateral incisor associated with palatally displaced canine (PDC) anomaly

Fifty-eight nonsyndromic North American white orthodontic patients with palatal displacement of one or both maxillary canine teeth were studied for associated tooth agenesis and peg-shaped maxillary lateral incisors. Agenesis of permanent teeth was identified by x-ray film analysis. Conical crown-size reduction (peg-shape anomaly) of the maxillary lateral incisor (l2) was determined by direct observation. Increases in absence of third molars and second premolars associated with the palatally displaced canine (PDC) anomaly were statistically very highly significant compared with normative data for tooth-agenesis prevalence. In contrast, the prevalence of l2 agenesis in the PDC sample showed no difference statistically compared with reference values. Reasons for this posterior site-specific suppression of tooth formation are not clear. The l2 peg-shape anomaly exceeded a 10-fold elevation in expression in the PDC sample, a very highly significant increase from normal prevalence. The findings are consistent with a hypothesis that the anomalies of tooth agenesis, tooth-size reduction, and PDC are biologic covariables in a complex of genetically related dental disturbances.

Ethylene provides positional information on cortical cell division but is not involved in Nod factor-induced root hair tip growth in Rhizobium-legume interaction

Nod factors secreted by Rhizobium leguminosarum bv. viciae induce root hair deformation, involving a reinitiation of tip growth, and the formation of nodule primordia in Vicia sativa (vetch). Ethylene is a potent inhibitor of cortical cell division, an effect that can be counteracted by applying silver ions (Ag+) or aminoethoxy-vinylglycine (AVG). In contrast to the inhibitory effect on cortical cell division, ethylene promotes the formation of root hairs (which involves tip growth) in the root epidermis of Arabidopsis. We investigate the possible paradox concerning the action of ethylene, putatively promoting Nod factor induced tip growth whilst, at the same time, inhibiting cortical cell division. We show, by using the ethylene inhibitors AVG and Ag+, that ethylene has no role in the reinitiation of root hair tip growth induced by Nod factors (root hair deformation) in vetch. However, root hair formation is controlled, at least in part, by ethylene. Furthermore, we show that ACC oxidase, which catalizes the last step in ethylene biosynthesis, is expressed in the cell layers opposite the phloem in that part of the root where nodule primordia are induced upon inoculation with Rhizobium. Therefore, we test whether endogenously produced ethylene provides positional information controlling the site where nodule primordia are formed by determining the position of nodules formed on pea roots grown in the presence of AVG or Ag+.

Directed proteomics identifies a plant-specific protein rapidly phosphorylated in response to bacterial and fungal elicitors

The perception of microbial signal molecules is part of the strategy evolved by plants to survive attacks by potential pathogens. To gain a more complete understanding of the early signaling events involved in these responses, we used radioactive orthophosphate to pulse-label suspension-cultured cells of Arabidopsis in conjunction with two-dimensional gel electrophoresis and mass spectrometry to identify proteins that are phosphorylated rapidly in response to bacterial and fungal elicitors. One of these proteins, AtPhos43, and related proteins in tomato and rice, are phosphorylated within minutes after treatment with flagellin or chitin fragments. By measuring (32)P incorporation into AtPhos43 immunoprecipitated from extracts of elicitor-treated hormone and defense-response mutants, we found that phosphorylation of AtPhos43 after flagellin treatment but not chitin treatment is dependent on FLS2, a receptor-like kinase involved in flagellin perception. Induction by both elicitors is not dependent on salicylic acid or EDS1, a putative lipase involved in defense signaling.

Changes in standard electrocardiographic ST-segment elevation predictive of successful reperfusion in acute myocardial infarction

The ability of the electrocardiographic ST segment to predict successful reperfusion after thrombolytic therapy remains controversial. To evaluate whether angiographically determined reperfusion could be predicted from changes in ST-segment elevation, the sum of ST-segment elevation in affected leads of the electrocardiogram was compared before and after thrombolytic therapy in 53 patients with acute myocardial infarction (AMI). Reperfusion status of the infarct-related artery was determined angiographically less than 8 hours from onset of symptoms. According to the Thrombolysis in Myocardial Infarction trial (TIMI) criteria, 33 patients had successful reperfusion (TIMI grade 2 to 3 flow) after thrombolytic therapy and 20 patients did not (TIMI grade 0 to 1 flow). Logistic multiple regression analysis showed that the proportional value for the shift in the sum of ST elevation, termed the "% ST change," was more strongly associated with reperfusion than the absolute measured difference in millimeters (chi-square = 11.34 vs 9.22). The entire spectra of sensitivities and specificities were determined to identify a level of the percent ST change with simultaneous high sensitivity and specificity. A 20% decrease in ST elevation provided such a level (88% sensitivity, 80% specificity). The positive and negative predictive values of a 20% decrease in ST elevation were 88 and 80%, respectively. These results suggest that a decrease of only 20% in the sum of ST elevation in the standard electrocardiogram after thrombolytic therapy is a useful noninvasive predictor of reperfusion status in patients with evolving AMI.

A prominent glycyl radical enzyme in human gut microbiomes metabolizes trans-4-hydroxy-l-proline

The human microbiome encodes vast numbers of uncharacterized enzymes, limiting our functional understanding of this community and its effects on host health and disease. By incorporating information about enzymatic chemistry into quantitative metagenomics, we determined the abundance and distribution of individual members of the glycyl radical enzyme superfamily among the microbiomes of healthy humans. We identified many uncharacterized family members, including a universally distributed enzyme that enables commensal gut microbes and human pathogens to dehydrate trans-4-hydroxy-l-proline, the product of the most abundant human posttranslational modification. This "chemically guided functional profiling" workflow can therefore use ecological context to facilitate the discovery of enzymes in microbial communities.

Some vertical lineaments of lip position

This study was performed to elucidate quantitatively upper lip-tooth-jaw relativity in the vertical dimension. Values for five linear dentolabial measurements were generated from male (n = 42) and female (n = 46) reference samples. In addition, three vertical skeletofacial dimensions and two vertical dental dimensions were recorded. A significant sexual dimorphism was found in the vertical lip-tooth-jaw relationship: the upper lip of the female subjects was positioned on average 1.5 mm more superiorly at maximum smile than the upper lip of the male subjects (p less than 0.01). High smile lines appeared to be a female lineament, and low smile lines appeared to be a male lineament. There was a significant sex difference in upper lip length: the male subjects exhibited a longer upper lip than the female subjects (p less than 0.001). The mean difference was 2.2 mm. A similarly significant male-female difference was seen in the skeletal maxillary height measurement: the male sample showed a 2.2 mm mean vertical maxillary increase over the female sample (p less than 0.001). Furthermore, a significant difference was found between the clinical crown height of the maxillary central incisors in the male and female subjects of comparable ages: the male group had longer central incisor crowns (p less than 0.01).

The palatally displaced canine as a dental anomaly of genetic origin

Palatal displacement of the maxillary canine tooth is a positional variation thought generally to develop as a result of local factors, such as retained deciduous canines, anomalous permanent lateral incisors, or dental crowding. This article contributes biologic evidence pointing to genetic factors as the primary origin of most palatal displacements and subsequent impactions of maxillary canine teeth. Data gathered from multiple sources are integrated to support a genetic etiology for the palatally displaced canine (PDC) on the basis of five evidential categories: 1. Occurrence of other dental anomalies concomitant with PDC; 2. Bilateral occurrence of PDC; 3. Sex differences in PDC occurrence; 4. Familial occurrence of PDC; 5. Population differences in PDC occurrence. From analysis of available evidence, the PDC positional anomaly appears to be a product of polygenic, multifactorial inheritance.

Adequacy of maxillary dental arch width in patients with palatally displaced canines

This study investigates maxillary dental arch width in subjects with palatally displaced canines. Pretreatment dental casts of orthodontic patients with one or both maxillary canines palatally displaced (n = 31; male, 10; female, 21) were collected. This sample was matched according to sex and age with pretreatment dental casts from unaffected orthodontic patients. Arch widths were recorded between the maxillary first premolars and between the maxillary first molars. Interpremolar arch width and intermolar arch width comparisons between the sample with palatally displaced canines and the reference sample showed no statistically significant differences in their means, thus indicating that there was no statistically significant difference in the anterior and posterior arch width between the affected subjects and the control subjects. Thus, affected patients exhibit adequacy of maxillary dental arch width. This evidence refutes earlier conclusions that deficiency in maxillary transverse arch width is an associated contributing factor in the genesis of the anomaly of palatally displaced canines. Clinically, adequacy of dental arch width helps explain the "nonextraction" diagnostic appearance of most of these patients when they present for treatment.

Persistent shock-elicited responding engendered by a negative-reinforcement procedure

A procedure in which responses reduced intermittently presented electric shocks to one quarter of their originally scheduled intensity, effectively engendered and maintained lever pressing in hooded rats. This contingency also markedly increased the response rates of rats initially trained under an unsignaled avoidance procedure. The responding of all animals extinguished rapidly when shock was withdrawn. Subsequently, it was discovered that high response rates could be maintained solely through presentation of shocks that were not affected by responses. Variations in the interval between shocks and changes in shock intensity over a wide range did not attenuate responding. Terminal performance was characterized by a consistent pattern of shock-elicited responses. Responses were also elicited by a tone following repeated tone-shock pairings. Finally, responding that was maintained by response-independent shocks was quickly suppressed by response-contingent shocks of the same intensity.

On the phenomenon of intraosseous migration of nonerupting teeth

Little is know about intraosseous migration of nonerupting teeth, a rare natural condition of horizontal tooth movement and impaction. It occurs only in the mandible and involves primarily the second premolar or the canine. When the second premolar is the affected tooth, it always is found distal to its normal position. The origins of the second premolar intraosseous migration phenomenon are obscure and usually no treatment is recommended. Intraosseous migration involving the canine is commonly called transmigration because the affected canine moves mesially across the mandibular symphysis to the opposite side of the mandible. Analysis of 50 published cases of canine transmigration indicated higher occurrence in women and no sidedness preference. In over 80% of the studied cases, the canine remained nonerupted and, of the 24 cases receiving some treatment, all but two underwent extraction of the anomalous canine. The canine transmigration phenomenon appears to show signs of having some genetic determinants.

Relation of temporal creatine kinase-MB release and outcome after thrombolytic therapy for acute myocardial infarction. TAMI Study Group

Measuring biochemical marker release after acute myocardial infarction helps in estimating infarct size and prognosis. We sought to relate in-hospital outcomes and curve-fitted creatine kinase (CK)-MB variables after thrombolysis. We measured CK-MB mass initially and at 30 and 90 minutes, and at 3, 8, and 20 hours after thrombolysis in 130 patients also undergoing cardiac catheterization at 90 minutes and at 5 to 7 days. Data were fitted, and maximums and curve areas calculated. CK-MB maximums related to infarct location (p = 0.014) and time to therapy (p = 0.002); curve area did not. Neither maximums nor curve area related to Thrombolysis in Myocardial Infarction trial flow grade at 90 minutes. Maximums related to ejection fraction at 90 minutes (p = 0.0004) and at 5 to 7 days (p = 0.0014), as did curve area (p = 0.0076 and 0.030, respectively). Maximums related to infarct zone function at 90 minutes (p = 0.024) and at 5 to 7 days (p = 0.042); curve area related only at 90 minutes (p = 0.027). Both maximums and curve area predicted congestive heart failure (p = 0.008 and p = 0.042, respectively) and a composite of congestive heart failure or death (p = 0.004 and p = 0.047, respectively); however, after adjusting for maximums, curve area no longer predicted congestive heart failure (p = 0.92). Maximums predicted the composite outcome after adjustment for curve area, and showed a trend toward predicting congestive heart failure (p = 0.089). We conclude that CK-MB maximums relate to infarct zone function, left ventricular function, and in-hospital outcomes after thrombolysis for acute myocardial infarction.

Functional analysis of separate topographies of aberrant behavior

We conducted a functional analysis of distinct topographies of aberrant behavior displayed by 4 clients. We first analyzed the behaviors in an aggregate fashion and then separated the behaviors to formulate hypotheses about the maintaining variables for each behavior. The procedures were used in a two-phase experiment. During Phase 1, two extended functional analyses were completed, one in an inpatient unit and one in a special education classroom. During Phase 2, two brief functional analyses were completed in an outpatient clinic. Results indicated that hypotheses of separate functions for distinct behaviors can be generated using both extended and brief functional analyses when the results are graphed in the aggregate and are separated by response topography. The results also suggest that these methods can improve the accuracy of data interpretation and treatment selection.

The effects of presession exposure to attention on the results of assessments of attention as a reinforcer

The effects of presession exposure to attention on responding during subsequent assessments of attention as a reinforcer were evaluated across three behavioral assessments. In Experiment 1, a contingent attention assessment condition was preceded by either a noncontingent attention condition (free play) or a contingent escape condition. In Experiment 2, a diverted attention with extinction condition was preceded by either an alone or a free-play condition. In Experiment 3, a two-choice preference assessment was preceded by either 10 min of free play or 10 min of playing alone. In each experiment, the participant responded differentially within the test condition according to the presence or absence of dense schedules of attention immediately prior to that condition. The results of this study show that events occurring immediately prior to an assessment condition can influence behavior within the assessment.

Skeletal asymmetry in esthetically pleasing faces

An x-ray cephalographic method was used to analyze 52 exceptionally well-balanced white adult faces for skeletal asymmetry in the posteroanterior (PA) projection. Three frontal facial lines were constructed using bilateral skeletal landmarks: latero-superior orbit (LO), lateral zygoma (Zyg), and gonion (Go). All subjects demonstrated measurable asymmetries. Data showed less asymmetry and more dimensional stability as the cranium is approached. A slight tendency toward right-side dominance was not statistically significant.

Sequential induction of the ethylene biosynthetic enzymes by indole-3-acetic acid in etiolated peas

Ethylene induced an increase in the accumulation of 1-aminocyclopropane-1-carboxylate (ACC) oxidase transcript level and enzyme activity in the first internode of 5- to 6-day-old etiolated pea (Pisum sativum L.) seedlings. Indole-3-acetic acid (IAA), which stimulates ethylene production by enhancing ACC synthase activity, also caused an increase in ACC oxidase transcript and activity levels. The IAA-induced increase in ACC oxidase mRNA level and enzyme activity was blocked by 2,5-norbornadiene (NBD), a competitive inhibitor of ethylene action. This indicates that IAA induced ACC oxidase through the action of ethylene. The level of ACC synthase mRNA and enzyme activity started to increase less than 1 h after the start of IAA treatment, whereas ACC oxidase activity and transcript levels began to rise after 2 h of IAA treatment. These results indicate that the enzymes of ethylene biosynthesis are sequentially induced after treatment of intact pea seedlings with IAA. The increase in ACC synthase activity leads to the production of ACC, which is converted by the low constitutive level of ACC oxidase activity to ethylene. Through a positive feedback loop, ethylene promotes the accumulation of ACC oxidase mRNA and the increase in ACC oxidase activity.

The gingival smile line

A comparative study was performed to examine the nature of the gingival smile line (GSL), a specific dentolabial configuration characterized by the exposure of maxillary anterior gingiva during a full smile. Five soft-tissue, three dental and three skeletal variables were selected, measured and reported for a GSL sample (n = 27) and a reference sample (n = 88), both consisting of North American white orthodontic patients with a median age of 14.4 years. The results indicated that the capacity to project a gingival smile was related to: anterior vertical maxillary excess and the muscular ability to raise the upper lip significantly higher than average when smiling. Other variables significantly associated with GSL were greater overjet, greater interlabial gap at rest, and greater overbite. Factors that did not appear associated with the GSL phenomenon were upper-lip length, incisor clinical crown height, mandibular plane angle, and palatal plane angle. Clinical aspects of GSL were discussed.

Running-wheel activity and avoidance in the mongolian gerbil

In the first of two experiments, running-wheel activity and unsignaled (Sidman) avoidance were studied in gerbils and albino rats. All gerbils ran at higher rates than any of the four rats studied. Under the avoidance procedure, four rats developed effective responding; the other two performed much less successfully. While avoidance developed more slowly in the gerbils, all showed asymptotic performance as effective as the four superior rats. The rats showed a consistent warm-up effect, receiving 60% to 80% of the total shocks in the initial third of the session. The gerbils displayed no warm-up, with shocks being evenly distributed over the session. Warm-up in the rats was not related to either response rate or to how effectively the animal was avoiding. When shock was removed, extinction occurred more rapidly in the rats than the gerbils. In the second experiment, which involved two-way shuttle avoidance, gerbils and albino mice quickly acquired the response. All animals met a criterion of 90% avoidance over 80 trials.

Frequency of tooth extraction in orthodontic treatment

Orthodontic extraction frequency describes the percentage of an orthodontic patient population experiencing extractions of one or more permanent teeth, excluding third molars. It is a useful statistical measure of the many variables associated with the extraction-nonextraction decision. For a study sample of 537 North American white orthodontic patients, the frequency of tooth extraction was determined as 42.1 percent. This is compared with a range of 6.5 percent to 83.5 percent reported in the world dental literature. Factors responsible for the enormous differences in orthodontic extraction frequency are explored. The study of extraction frequency offers a simple, valuable aid for the clinician to understand better the nature of his patient population, his treatment methods, and his rationalizations.

Assessment of coronary reperfusion after thrombolysis with a model combining myoglobin, creatine kinase-MB, and clinical variables. TAMI-7 Study Group. Thrombolysis and Angioplasty in Myocardial Infarction-7

BACKGROUND

Several biochemical markers have been investigated for the noninvasive assessment of reperfusion after myocardial infarction. Because myoglobin is released very soon after myocardial injury and clears rapidly after reperfusion, it may prove to be an excellent marker of occlusion and reperfusion.

METHODS AND RESULTS

We examined the relation between various myoglobin measures and Thrombolysis In Myocardial Infarction (TIMI) flow grade in 96 patients enrolled in a study of front-loaded thrombolysis who underwent 90-minute angiography. We also combined myoglobin measures with models that include clinical and creatine kinase-MB variables. The myoglobin level measured within 10 minutes of acute angiography showed the best overall performance and was used for later analyses. Of the clinical variables examined, only time from symptom onset to thrombolysis and chest pain grade at angiography discriminated among TIMI flow grades. Combining the 90-minute myoglobin level and these clinical variables showed a significant difference (P<.0001) between both TIMI 3 versus TIMI 0 through 2 and TIMI 2 or 3 versus TIMI 0 or 1 flow. When the 90-minute myoglobin level was added to an established predictive model containing clinical variables and creatine kinase-MB measures, its contribution remained significant (P=.044). The area under the receiver operator characteristic curve for this combined model was .88.

CONCLUSIONS

A single myoglobin measurement obtained 90 minutes after the start of thrombolysis, combined with select clinical variables and creatine kinase-MB levels, enhances the noninvasive prediction of reperfusion after myocardial infarction.

Effects of escape to alone versus escape to enriched environments on adaptive and aberrant behavior

Escape-maintained aberrant behavior may be influenced by two outcomes: (a) a break from the activity and (b) subsequent access to preferred activities. To assess this hypothesis, a treatment was developed that analyzed response allocation across two break options: break alone and break with access to preferred social activities. The break with preferred activities decreased aberrant behavior and increased appropriate behavior.