Transesophageal echocardiographic imaging workshop: a basic transverse plane examination sequence

This workshop describes a 10-step sequence of transverse plane two-dimensional transesophageal echocardiographic views of the heart and great vessels that constitutes a basic standardized examination capable of being performed by a beginning practitioner.     

Intraoperative two-dimensional echocardiography and color flow Doppler imaging: a basic transesophageal single plane patient examination sequence.

Recent advances in technology have allowed application of transesophageal echocardiography to intraoperative care of critically ill patients. Early clinical application primarily involved evaluation of left ventricular regional wall motion. However, valid intraoperative use of transesophageal echocardiography should also encompass systematic assessment of the entire heart as well as the great vessels. This report describes a 10-step sequence of single plane, two-dimensional echocardiographic views which constitute a basic patient examination capable of being performed by a practitioner whose primary responsibility is the delivery of anesthesia care. A 5-step color flow Doppler examination sequence is also presented. These views complement the two-dimensional echocardiographic steps. Representations of methods for grading Doppler-defined valvular regurgitation complete the report.     

Visualization of anomalous origin and course of coronary arteries in 748 consecutive symptomatic patients by 64-slice computed tomography angiography

Background

While the order for a clinical transthoracic examination is fairly standardized, there is considerable variability between laboratories and even among physicians in the same laboratory with regard to the order for transesophageal echocardiograms (TEE). A systematic approach is desirable for more efficient use of physician and patient time, avoidance of inadvertent omission of important views, and to facilitate study review.

Methods

We propose a standardized approach to TEE data acquisition in which cardiac structures are systematically identified and characterized at sequential positions and imaging planes to facilitate organized, efficient and comprehensive assessment.

Results

Our approach to TEE study begins in the mid-esophagus with the imaging plane at 0°. Based on the specific indication for the TEE, a cardiac structure (e.g., mitral valve, left atrial appendage, or interatrial septum) is chosen as the primary focal point for a comprehensive, multiplane analysis. This structure is assessed in 20° – 30° increments as the imaging plane is advanced from 0° to 165°. Using the aortic valve as a reference point, pertinent cardiac structures are then assessed as the imaging plane is reduced to 135°, to 90°, to 40 – 60° and then back to 0°. The probe is then advanced into the stomach to obtain transgastric images at 0°, 90°, and 120°. Finally, the thoracic aorta and pulmonary artery are assessed as the probe is withdrawn from the body. Using this method, an organized and comprehensive TEE can be performed in 10 – 15 minutes.

Conclusion

A standardized and systematic TEE approach is described for efficient and comprehensive TEE study.     

Orientation of cortical microtubules correlates with cell shape and division direction

Summary Cortical microtubules in the epidermis of regeneratingGraptopetalum plants were examined by in situ immunofluorescence. Paradermal slices of tissue were prepared by a method that preserves microtubule arrays and also maintains cell junctions. To test the hypothesis that cortical microtubule arrays align perpendicular to the direction of organ growth, arrays were visualized and their orientation quantified. A majority of microtubules are in transverse orientation with respect to the organ axis early in shoot development when the growth habit is uniform. Later in development, when growth habit is non-uniform and the tissue is contoured, cortical microtubules are increasingly longitudinal and oblique in orientation. Microtubules show only a minor change in orientation at the site of greatest curvature, the transition zone of a developing leaf. To assess the role of the division plane on orientation of arrays, the pattern of microtubules was examined in individual cells of common shape. Cells derived from transverse divisions have predominately transverse cortical arrays, whereas cells derived from oblique and longitudinal divisions have non-transverse arrays. The results show that, regardless of the stage of development, microtubules orient with respect to cell shape and plane of division. The results suggest that cytoskeletal function is best considered in small domains of growth within an organ.Abbrevations DMSO dimethylsulfoxide - EGTA ethylene glycol-bis-(ß-aminoethyl ether)-N, N, N, N-tetra acetic acid - FITC fluorescein isothiocyanate - MTSB microtubule stabilizing buffer - PBS phosphate buffered saline     

Abdominal incisions for operations on the colon and rectum

The magnitude of extirpative operations of the colon and rectum, advanced by improved supportive measures, may be increased by decreasing the extent of transverse abdominal incisions. The right colon can be removed with facility through a transverse incision across the left upper abdomen.A left upper transverse incision, plus either an oblique or a Cherney incision, is preferable to a long vertical incision.     

THE CONTROL OF THE ORIENTATION OF CELL DIVISIONS IN FERN GAMETOPHYTES

Time-lapse observations of filamentous fern gametophytes were used to evaluate whether the plane of cell division is referable to the plane of minimal surface area before and during the transition to two-dimensional growth. Cell dimensions of the apical cell were related to the length/width ratios associated with minimal area in the transverse plane vs. longitudinal plane, by modeling the apical cell as a hemisphere subtended by a cylinder. Our working hypothesis predicts that filamentous growth is perpetuated by an apical cell geometry that makes the transverse division plane the orientation of minimal surface area, whereas the transition to two-dimensional growth (longitudinal division of the apical cell) occurs once the longitudinal plane becomes the position of minimal surface area. The predictions of this hypothesis are fulfilled regardless of variations in light intensity and light quality, the presence of regulators of metabolism, or whether the experimental perturbation causes a corresponding selective inhibition of the transition to two-dimensional growth. Thus, the control of the plane of cell division in this system seems to depend on thermodynamic considerations of surface area. Furthermore, we favor the conclusion that the role of the genome in the transition to two-dimensional growth involves its influence on apical cell dimensions rather than the induction of specific genes for specific morphogenetic mRNAs.     

Symmetry perception by poultry chicks and its implications for three-dimensional object recognition

Bilateral symmetry is visually salient to diverse animals including birds, but whereas experimental studies typically use bilaterally symmetrical two-dimensional patterns that are viewed approximately fronto-parallel; in nature, animals observe three-dimensional objects from all angles. Many animals and plant structures have a plane of bilateral symmetry. Here, we first (experiment I) give evidence that young poultry chicks readily generalize bilateral symmetry as a feature of two-dimensional patterns in fronto-parallel view. We then test the ability of chicks to recognize symmetry in images that would be produced by the transformed view produced by a 40° horizontal combined with a 20° vertical rotation of a pattern on a spherical surface. Experiment II gives evidence that chicks trained to distinguish symmetrical from asymmetrical patterns treat rotated views of symmetrical 'objects' as symmetrical. Experiment III gives evidence that chicks trained to discriminate rotated views of symmetrical 'objects' from asymmetrical patterns generalize to novel symmetrical objects either in fronto-parallel or rotated view. These findings emphasize the importance of bilateral symmetry for three-dimensional object recognition and raise questions about the underlying mechanisms of symmetry perception.     

Nucleus-associated microtubules help determine the division plane of plant epidermal cells: avoidance of four-way junctions and the role of cell geometry

To investigate the spatial relationship between the nucleus and the cortical division site, epidermal cells were selected in which the separation between these two areas is large. Avoiding enzyme treatment and air drying, Datura stramonium cells were labeled with antitubulin antibodies and the three-dimensional aspect of the cytoskeletons was reconstructed using computer-aided optical sectioning. In vacuolated cells preparing for division, the nucleus migrates into the center of the cell, suspended by transvacuolar strands. These strands are now shown to contain continuous bundles of microtubules which bridge the nucleus to the cortex. These nucleus-radiating microtubules adopt different configurations in cells of different shape. In elongated cells with more or less parallel side walls, oblique strands radiating from the nucleus to the long side walls are presumably unstable, for they are progressively realigned into a transverse disc (the phragmosome) as broad, cortical, preprophase bands (PPBs) become tighter. The phragmosome and the PPB are both known predictors of the division plane and our observations indicate that they align simultaneously in elongated epidermal cells. These observations suggest another hypothesis: that the PPB may contain microtubules polymerized from the nuclear surface. In elongated cells, the majority of the radiating microtubules, therefore, come to anchor the nucleus in the transverse plane, consistent with the observed tendency of such cells to divide perpendicular to the long axis. In nonrectangular isodiametric epidermal cells, which approximate regular hexagons in section, the radial microtubular strands emanating from the nucleus tend to remain associated with the middle of each subtending cell wall. The strands are not reorganized into a single dominant transverse bar, but remain as a starlike array until mitosis. PPBs in these cells are not as tight; they may only be a sparse accumulation of microtubules, even forming along non-diametrical radii. This arrangement is consistent with the irregular division patterns observed in epidermal mosaics of isodiametric D. stramonium cells. The various conformations of the radial strands can be modeled by springs held in two-dimensional hexagonal frames, and by soap bubbles in three-dimensional hexagonal frames, suggesting that the division plane may, by analogy, be selected by minimal path criteria. Such behavior offers a cytoplasmic explanation of long-standing empirically derived "rules" which state that the new cell wall tends to meet the maternal wall at right angles. The radial premitotic strands and their analogues avoid taking the longer path to the vertex of an angle where a cross wall is already present between neighboring cells.(ABSTRACT TRUNCATED AT 400 WORDS)     

Transverse rectus sheath plication in abdominoplasty

The standard abdominoplasty technique uses a wide, vertically oriented plication of the rectus sheath to narrow the waistline. This reduces the contribution of the rectus sheath to the anterior abdominal wall from more than 50 percent to 25 percent or less and creates an unnaturally flat appearance. No amount of exercise can restore the native form of the rectus sheath. For the past 3 years, the authors have performed a transverse plication of the rectus sheath, to address vertical laxity, complemented by a bilateral crescent-shaped plication of the external oblique fascia, to address waistline contour. Six consecutive patients who underwent the transverse rectus plication technique were compared with a similar group of patients who underwent vertical rectus plication. Comparison was made via preoperative and postoperative photographic analysis by two impartial judges. Although the overall result was excellent in both groups, the global score was significantly higher in the transverse plication group (4.5 versus 3.9, p = 0.044). Scores for anterior abdominal contour (4.7 versus 4.2, p = 0.029) and definition of the linea semilunaris (4.6 versus 3.7, p = 0.008) were also significantly higher for the transverse plication group. The difference for waistline contour (4.5 versus 3.8, p = 0.067), definition of the linea alba (4.4 versus 3.9, p = 0.067), and hip-waist transition (4.4 versus 3.7, p = 0.067) did not reach statistical significance. The outline of the rectus sheath is a significant portion of what is perceived as an aesthetic abdomen. Transverse plication of the rectus sheath with bilateral crescent-shaped plications of the external oblique fascia retains this native form. The result is improved anterior abdominal contour and definition of the rectus sheath with a comparable or better improvement in waistline contour and transition from the hips to the waist when compared with wide, vertical rectus plication.     

地钱颈卵器发育和卵发生的显微观察及细胞化学研究

对地钱（Marchantia polymorpha）颈卵器发育和卵发生过程进行了显微观察和细胞化学的研究,颈卵器起始于原始细胞,该细胞呈乳突状,经横分裂产生基细胞和顶细胞,顶细胞经3次纵斜向分裂和1次横分裂产生初生细胞,初生细胞是颈卵器内的第一个细胞,经横分裂产生中央细胞和颈沟母细胞,前者产生1个腹沟细胞和1个卵细胞,后者最终产生4个颈沟细胞。颈卵器的成熟表现为颈部显著伸长和腹部膨大,卵细胞成熟时具有不规则的核,细胞质内含有丰富的囊泡和颗粒物,卵细胞周围充满粘性物质,细胞化学研究表明,该粘性物质为多糖,卵细胞质中深染色的颗粒可能为脂类物质,腹沟细胞自产生后就逐渐退化,颈沟细胞的退化迟于腹沟细胞,其数量通常为4个,偶尔可见5个颈沟细胞或具有双核的现象。     

Testing of antiviral compounds against Mengo virus infection of mice. A 2-step procedure of in vivo screening.

A 2-step procedure of screening of antiviral compounds in vivo is presented on the basis of standardized methods of both experimental examination and statistical analysis. The procedure uses the "rate of protection" R as the sole criterion of activity. In the first step, requiring a total of 40 mice, compounds with significant R are detected. Drugs producing R less than 15% are discarded. Compounds eliciting R larger than or equal to 15%, without significance, are examined in a second step, using again 40 mice, to decide whether the protective activity becomes significant employing a greater number of animals. The procedure works with relatively less expense with regard of the number of animals used and the time required. The procedure can be applied to test systems based on lethal infections as well as to test models for which the use of the "rate of protection" is relevant.     

ULTRASTRUCTURAL ORGANIZATION OF OBLIQUELY STRIATED MUSCLE FIBERS IN ASCARIS LUMBRICOIDES

The somatic musculature of the nematode, Ascaris, is currently thought to consist of smooth muscle fibers, which contain intracellular supporting fibrils arranged in a regular pattern. Electron microscopic examination shows that the muscle fibers are, in fact, comparable to the striated muscles of vertebrates in that they contain interdigitating arrays of thick and thin myofilaments which form H, A, and I bands. In the A bands each thick filament is surrounded by about 10 to 12 thin filaments. The earlier confusion about the classification of this muscle probably arose from the fact that in one longitudinal plane the myofilaments are markedly staggered and, as a result, the striations in that plane of section are not transverse but oblique, forming an angle of only about 6° with the filament axis. The apparent direction of the striations changes with the plane of the section and may vary all the way from radial to longitudinal. A three-dimensional model is proposed which accounts for the appearance of this muscle in various planes. Z lines as such are absent but are replaced by smaller, less orderly, counterpart "Z bundles" to which thin filaments attach. These bundles are closely associated with fibrillar dense bodies and with deep infoldings of the plasma membrane. The invaginations of the plasma membrane together with intracellular, flattened, membranous cisternae form dyads and triads. It is suggested that these complexes, which also occur at the cell surface, may constitute strategically located, low-impedance patches through which local currents are channeled selectively.     

Cardiac output monitoring by echocardiography: should we pass on Swan-Ganz catheters?

Transesophageal echocardiography offers a noninvasive technique for the continuous monitoring of cardiac performance. The combination of 2-dimensional echocardiography and Doppler velocitometry provide assessment of cardiac anatomy, valve function and, ventricular loading conditions. Although transesophageal echocardiography has become accepted for perioperative monitoring, it is typically used in conjunction with Swan-Ganz catheterization. To supplant Swan-Ganz catheters, an echocardiographic technique to monitor cardiac output is necessary. Despite considerable effort to achieve this goal, a satisfactory technique has been difficult to realize. This paper discusses the role of cardiac output monitoring in perioperative care and critically examines echocardiographic techniques for cardiac output monitoring.     

Muscles that act on glabellar skin: a closer look

The coronal incision forehead lift became a component of the face-lift procedure 35 years ago and increased the cosmetic benefit for the facial aesthetic surgery patient. Later, this enhanced cosmetic effect achieved from eyebrow resuspension was complemented by treatment of the glabellar skin lines by modifying corrugator supercilii and procerus muscle function through the same coronal incision. In recent years, newer procedures for treating the corrugator supercilii and procerus muscles by using endoscopy or limited incision techniques have eliminated the need for the coronal incision. With these newer techniques has come a renewed interest in the surgical anatomy of the muscle complex that acts on glabellar skin. This study was designed to examine the current understanding of the anatomy of these muscles and to resolve misconceptions and controversy concerning them. Fresh cadaver dissections and simulated muscle action studies done on the glabellar musculature of four specimens were correlated with nerve blockade studies performed in 10 subjects on the temporal and zygomatic branches of the facial nerve. The presence of the depressor supercilii muscle as a distinct entity was confirmed. The little-appreciated oblique head of the corrugator supercilii muscle was identified. The conclusions from this study suggest that the transverse head of the corrugator supercilii muscle produces the vertical component of the glabellar skin line and also contributes to the formation of the oblique component of the glabellar skin line. The oblique head of the corrugator supercilii muscle, the depressor supercilii muscle, and the medial head of the orbital portion of the orbicularis oculi muscle all appear to depress the medial head of the eyebrow and contribute to the formation of the oblique glabellar skin line. The nerve block study provided evidence that the zygomatic branch of the facial nerve supplies the three medial eyebrow depressor muscles, which opens the possibility for future nerve ablation techniques to control the action of the medial eyebrow depressor muscle group. This nerve block study also supports the concept of "physiologic" elevation of the medial eyebrow as an effective component of foreheadplasty.     

On the neurons with dendrites intermingling with the fibers of the human corpus callosum: a Golgi picture

Golgi preparations of the anterior part of the truncus of the corpus callosum from 11 adult human brains were investigated. The vertical plane of section was situated symmetrically between the frontal and sagittal plane. The use of this oblique plane of section enabled easy identification of the neurons with dendrites intermingling with transcallosal fibers, what was not possible in standard frontal sections. 2 types of such neurons (with features of other interstitial neurons) were described: fusiform and multipolar. Both types of neurons were more frequently impregnated in areas adjacent to induseum griseum, cingular cortex, and in the depth of the callosal sulcus. Multipolar neurons were also present in the central core and in ventral parts of the corpus callosum, but fusiform ones were not present in ventral parts of the corpus callosum truncus. The dentrites of both types of neurons usually were perpendicular to, sometimes also parallel to transcallosal fibers. The impregnation of these neurons in groups and pairs suggest their integrative role, and their planar orientation in mentioned oblique plane corresponds to oblique direction of transcallosal cingulostriatal decussating fibers.     

INTEGRATION AND SYMMETRY IN BEROE

Despite the fact that certain prominent structures such as theeight comb-rows at first suggest an octomerous radial symmetryin ctenophores, close examination of their anatomy reveals ratherthe existence of two main planes, the sagittal and the transverse.Further, in certain forms in which one plane or the other hasbecome predominant, an apparent bilateral symmetry emerges. Relationships between anatomical and physiological symmetrywere looked for by studying the behavior of Beroe ovata andBeroe forskalii, both with regard to coordinated ciliary movementsbetween the comb-rows, and to the postures assumed during locomotion,balance, and rest in intact animals, and in animals from whichthe aboral organ had been removed. Swimming behavior is found to exhibit an octomerous functionalsymmetry. Bendings and vertical balance, however, show a tetramerousorganization. In the last case the unique properties of thestatocyst, with a structure characteristic of a regulator ofcybernetic patterns, the machines of which are the comb-rows,permit the most efficient integration of all the phenomena involvedin maintaining the vertical position. Finally the resting horizontalposition reflects a physiological bilateral symmetry basic tothe sagittal plane.     

Prenatal Organophosphates Exposure Alternates the Cleavage Plane Orientation of Apical Neural Progenitor in Developing Neocortex

Prenatal organophosphate exposure elicits long-term brain cytoarchitecture and cognitive function impairments, but the mechanism underlying the onset and development of neural progenitors remain largely unclear. Using precise positioned brain slices, we observed an alternated cleavage plane bias that emerged in the mitotic neural progenitors of embryonal neocortex with diazinion (DZN) and chlorpyrifos (CPF) pretreatment. In comparison with the control, DZN and CPF treatment induced decrease of vertical orientation, increase of oblique orientation, and increase of horizontal orientation. That is, the cleavage plane orientation bias had been rotated from vertical to horizontal after DZN and CPF treatment. Meanwhile, general morphology and mitotic index of the progenitors were unchanged. Acephate (ACP), another common organophosphate, had no significant effects on the cleavage plane orientation, cell morphology and mitotic index. These results represent direct evidence for the toxicity mechanism in onset multiplication of neural progenitors.     

Muscle activity during the active straight leg raise (ASLR), and the effects of a pelvic belt on the ASLR and on treadmill walking

Women with pregnancy-related pelvic girdle pain (PPP), or athletes with groin pain, may have trouble with the active straight leg raise (ASLR), for which a pelvic belt can be beneficial. How the problems emerge, or how the belt works, remains insufficiently understood. We assessed muscle activity during ASLR, and how it changes with a pelvic belt. Healthy nulligravidae (N=17) performed the ASLR, and walked on a treadmill at increasing speeds, without and with a belt. Fine-wire electromyography (EMG) was used to record activity of the mm. psoas, iliacus and transversus abdominis, while other hip and trunk muscles were recorded with surface EMG. In ASLR, all muscles were active. In both tasks, transverse and oblique abdominal muscles were less active with the belt. In ASLR, there was more activity of the contralateral m. biceps femoris, and in treadmill walking of the m. gluteus maximus in conditions with a belt. For our interpretation, we take our starting point in the fact that hip flexors exert a forward rotating torque on the ilium. Apparently, the abdominal wall was active to prevent such forward rotation. If transverse and oblique abdominal muscles press the ilia against the sacrum (Snijders’ “force closure”), the pelvis may move as one unit in the sagittal plane, and also contralateral hip extensor activity will stabilize the ipsilateral ilium. The fact that transverse and oblique abdominal muscles were less active in conditions with a pelvic belt suggests that the belt provides such “force closure”, thus confirming Snijders’ theory.     

Three-dimensional motion of the organ of Corti

The vibration of the organ of Corti, a three-dimensional micromechanical structure that incorporates the sensory cells of the hearing organ, was measured in three mutually orthogonal directions. This was achieved by coupling the light of a laser Doppler vibrometer into the side arm of an epifluorescence microscope to measure velocity along the optical axis of the microscope, called the transversal direction. Displacements were measured in the plane orthogonal to the transverse direction with a differential photodiode mounted on the microscope in the focal plane. Vibration responses were measured in the fourth turn of a temporal-bone preparation of the guinea-pig cochlea. Responses were corrected for a "fast" wave component caused by the presence of the hole in the cochlear wall, made to view the structures. The frequency responses of the basilar membrane and the reticular lamina were similar, with little phase differences between the vibration components. Their motion was rectilinear and vertical to the surface of their membranes. The organ of Corti rotated about a point near the edge of the inner limbus. A second vibration mode was detected in the motion of the tectorial membrane. This vibration mode was directed parallel to the reticular lamina and became apparent for frequencies above approximately 0.5 oct below the characteristic frequency. This radial vibration mode presumably controls the shearing action of the hair bundles of the outer hair cells.     

Root contraction in hyacinth III. Orientation of cortical microtubules visualized by immunofluorescence microscopy

Summary Cortical microtubules (MTs) were visualized in root cortex cells ofHyacinthus orientalis L. using immunofluorescence techniques. Cellular MT orientation was determined adjacent to radial longitudinal and transverse walls of root tip, uncontracted, contracting, and fully contracted regions. As seen in longitudinal views, MTs formed parallel, apparently helical arrays which were oriented transversely, axially or obliquely depending upon the region. Transverse sectional views showed that MTs adjacent to transverse cell walls formed a variety of patterns which varied with developmental stage and cell location. Microtubules were oriented in crisscross or parallel arrays. The parallel arrays were oriented either parallel, perpendicular or oblique to the radius of the root. There was an apparent temporal progression in MT reorientation from outer cortical to inner cortical cell layers. A resultant progression of reoriented cell growth could account for root contraction. These findings corroborate earlier electron microscopic observations of changing MT orientation accompanying root contraction, and provide cytological evidence to test mathematical and biophysical models of the mechanics of cell expansion.Abbreviations MT microtubule - MF microfibril - MTSB microtubule stabilizing buffer - PBS phosphate buffered saline