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Incidence and prognostic significance of lateral lymph node metastasis in patients with advanced low rectal cancer.

BACKGROUND: Lateral lymph node metastases occur in some patients with low rectal cancer and may cause local recurrence after total mesorectal excision. The aims of this study were to identify risk factors for lateral node metastases in patients with pathological tumour (pT) stage 3 or pT4 low rectal adenocarcinoma, and to evaluate the prognostic significance of lateral node metastases. METHODS: A retrospective analysis was performed of the outcome of 237 patients with pT3 or pT4 low rectal adenocarcinoma who underwent R0 resection with systematic lateral node dissection. RESULTS: Lateral lymph node metastases were found in 41 patients (17.3 per cent). Increased risk of lateral lymph node metastases was associated with a distal tumour margin close to the anal margin, histological type other than well or moderately differentiated adenocarcinoma, and the presence of mesenteric lymph node metastases. Patients with lateral node metastases had a significantly shorter postoperative survival (5-year survival rate 42 versus 71.6 per cent; P < 0.001) and an increased risk of local recurrence (44 versus 11.7 per cent; P < 0.001) compared with those without lateral node metastases. CONCLUSION: Tumour site, histological type and the presence of mesenteric lymph node metastasis are factors predicting the risk of lateral node metastasis. The poor prognosis of patients with lateral lymph node metastases after systematic lateral dissection suggests the need for adjuvant therapy.

Adenocarcinoma↗

Primary neurons of the lateral line nerves and their central projections in hagfishes.

The hagfish lateral line system was studied by horseradish peroxidase transganglionic transport. The anterior lateral line nerve innervates the group of lateral line canals situated anteriorly to the eye, and the posterior lateral line nerve innervates the group of canals situated posteriorly to the eye. Although both nerves pass through the muscle fascia at the same point, each runs a different course to the brain. The anterior lateral line nerve runs near the trigeminal nerve and its ganglion is closely attached to the trigeminal ganglion, but both systems are completely independent. The posterior lateral line nerve runs independently of any other cranial nerve and makes a peculiar U-turn at the point of entry to the brain capsule. The anterior lateral line ganglion contains both cutaneous sensory cells (small to large cells) and lateral line sensory cells (small cells); from this ganglion projections run to both the trigeminal sensory nucleus (fine and thick fibers) and medial nucleus of the area acousticolateralis (fine fibers). The posterior lateral line ganglion contains only small lateral line cells that project fine fibers to the medial nucleus of the area acousticolateralis. There are no efferent components in this lateral line system, and its only afferent terminal field is the medial nucleus of the area acousticolateralis.

Afferent Pathways↗

Loss of ectodermal competence for lateral line placode formation in the direct developing frog Eleutherodactylus coqui.

In the direct-developing frog Eleutherodactylus coqui neuromasts and ganglia of the lateral line system never develop. We show here that this absence of the lateral line system, which is evolutionarily derived in anurans, is due to very early changes in development. Ectodermal thickenings, which are typical of lateral line placodes, and from which neuromasts and ganglion cells of the lateral line originate, never form in E. coqui, although other neurogenic placodes are present. Moreover, although NeuroD is expressed in the lateral line placodes of Xenopus laevis, corresponding expression sites are lacking in E. coqui. Heterospecific transplantation experiments show that axolotl ectoderm can be induced to form lateral line placodes after transplantation to E. coqui hosts but that E. coqui ectoderm does not form lateral line placodes on axolotl hosts. This suggests that the loss of the lateral line system in E. coqui is due to the specific loss of ectodermal competence to form lateral line placodes in response to inductive signals. Our results (1) indicate that the competence for lateral line placode formation is distinct and dissociable from the competence to form other neurogenic placodes and (2) support the idea that the lateral line system acts as a module in development and evolution.

Animals↗

Laminar organization of acetylcholinesterase and cytochrome oxidase in the lateral geniculate nucleus of prosimians.

Hess and Rockland [Hess and Rockland (1983) Brain Res. 289, 322-325] proposed that the distribution of acetylcholinesterase within the lateral geniculate nucleus might correlate with the daily activity patterns shown by primates. In diurnal primates, the magnocellular laminae show a greater acetylcholinesterase reaction product. In nocturnal primates, the parvocellular laminae are more heavily stained. We have examined the laminar distribution of acetylcholinesterase and cytochrome oxidase in the lateral geniculate nucleus of a series of rare prosimian primates. In all prosimians examined, the most dense acetylcholinesterase reaction product is seen in the parvocellular layers of the lateral geniculate nucleus. Heavy cytochrome oxidase activity is seen in both the magnocellular and parvocellular layers, but not the koniocellular layers of the prosimian lateral geniculate nucleus. We have also employed a polyclonal antibody to choline acetyltransferase to examine the laminar organization or cholinergic activity in the Galago (Bushbaby) lateral geniculate nucleus. We report that choline acetyltransferase immunoreactivity does not correlate with acetylcholinesterase activity in the prosimian lateral geniculate nucleus. Although the lateral geniculate nucleus is more immunoreactive than most other thalamic structures and although the intercalated koniocellular laminae demonstrate somewhat lighter choline acetyltransferase immunoreactivity, no great difference in staining intensity is seen between the parvocellular and magnocellular laminae. In addition, we examined the phenotype of known inputs to assess the laminar specificity of cholinergic projections to the bushbaby lateral geniculate nucleus. Layer VI of primary visual cortex, which is known to be a source of acetylcholinesterase in the parvocellular layers, does not contain cholinergic cells, nor does the pretectal nucleus, which projects mainly to the parvocellular layers. The parabigeminal nucleus is cholinergic; however, this nucleus is known to project to the koniocellular layers, along with the non-cholinergic superior colliculus. Finally, the pedunculopontine tegmental nucleus, which provides a strong input to many regions of the thalamus, including the lateral geniculate nucleus, is cholinergic. The laminar organization of its input to the lateral geniculate nucleus is not known. Increased acetylcholinesterase reaction product within the parvocellular layers of the lateral geniculate nucleus is common to all strepsirhine primates. The pattern is also seen in the only two nocturnal haplorhine primates, Tarsius and Aotus (owl monkey). The relation of this increased acetylcholinesterase activity to cholinergic function remains unclear.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholinesterase↗

Effect of two obturation techniques on the filling of lateral canals and the main canal.

The three-dimensional obturation of the root canal system is widely accepted as a key factor for successful endodontic therapy. The purpose of this study was to evaluate the obturation of lateral canals and the main canal using cold lateral condensation versus the gutta-percha coated rigid carrier. Thirty epoxy blocks with five lateral canals placed at varying angles from the main canal were used. Each experimental group was obturated by a board certified endodontist with clinical experience in the respective obturation technique. The length of gutta-percha and sealer in the lateral canals was measured under a microscope (x30, Unitron) to the nearest 0.5 mm. The blocks were sectioned with an Isomet Plus precision saw (Buehler, Lake Bluff, IL) and copious water irrigation perpendicular to the main canal at the apex, the height of contour, and at 0.8, 1.6 and 2.4 mm from the canal apex. A microscope (x100, Leitz, Switzerland) was used to determine voids. There was significantly (p < .001) more gutta-percha in the lateral canals with the gutta-percha coated rigid carrier technique. In contrast, the cold lateral condensation technique had significantly (p < .001) more sealer in the lateral canals. However, there was no significant (p < .05) difference, in gutta-percha-plus-sealer filling of the lateral canals, between the two techniques. In the apical 1 mm of the main canal there were significantly (p < .011) fewer voids with the gutta-percha coated rigid carrier technique compared to the cold lateral condensation. In the model chosen, the gutta-percha coated rigid carrier technique and the cold lateral condensation technique were equally effective in filling lateral canals. In filling the main canal, however, the coated rigid carrier technique was more effective.

Dental Pulp Cavity↗

Connections of the rat lateral septal complex.

The organization of lateral septal connections has been re-examined with respect to its newly defined subdivisions, using anterograde (PHAL) and retrograde (fluorogold) axonal tracer methods. The results confirm that progressively more ventral transverse bands in the hippocampus (defined by the orientation of the trisynaptic circuit) innervate progressively more ventral, transversely oriented sheets in the lateral septum. In addition, hippocampal field CA3 projects selectively to the caudal part of the lateral septal nucleus, which occupies topologically lateral regions of the transverse sheets, whereas field CA1 and the subiculum project selectively to the rostral and ventral parts of the lateral septal nucleus, which occupy topologically medial regions of the transverse sheets. Finally, the evidence suggests that progressively more ventral hippocampal bands innervate progressively thicker lateral septal sheets. In contrast, ascending inputs to the lateral septum appear to define at least 20 vertically oriented bands or subdivisions arranged orthogonal to the hippocampal input (Risold, P.Y. and Swanson, L.W., Chemoarchitecture of the rat lateral septal nucleus, Brain Res. Rev., 24 (1997) 91-113). Hypothalamic nuclei forming parts of behavior-specific subsystems share bidirectional connections with specific subdivisions of the lateral septal nucleus (especially the rostral part), suggesting that specific domains in the hippocampus may influence specific hypothalamic behavioral systems. In contrast, the caudal part of the lateral septal nucleus projects to the lateral hypothalamus and to the supramammillary nucleus, which projects back to the hippocampus and receives its major inputs from brainstem cell groups thought to regulate behavioral state. The neural system mediating defensive behavior shows these features rather clearly, and what is known about its organization is discussed in some detail.

Animals↗

Lateral flagella of Aeromonas species are essential for epithelial cell adherence and biofilm formation.

Mesophilic Aeromonas strains express a single polar flagellum in all culture conditions and produce lateral flagella on solid media. Such hyperflagellated cells demonstrate increased adherence. Nine lateral flagella genes, lafA-U for Aeromonas hydrophila, and four Aeromonas caviae genes, lafA1, lafA2, lafB and fliU, were isolated. Mutant characterization, nucleotide and N-terminal sequencing demonstrated that the A. hydrophila and A. caviae lateral flagellins were almost identical, but were distinct from their polar flagellum counterparts. The aeromonad lateral flagellins exhibited higher molecular masses on SDS-PAGE, and this aberrant migration was thought to result from post-translational modification through glycosylation. Mutation of the Aeromonas lafB, lafS or both A. caviae lateral flagellins caused the loss of lateral flagella and a reduction in adherence and biofilm formation. Mutations in lafA1, lafA2, fliU or lafT resulted in strains that expressed lateral flagella, but had reduced adherence levels. Mutation of the lateral flagella loci did not affect polar flagellum synthesis, but the polarity of the transposon insertions on the A. hydrophila lafTlU genes resulted in non-motility. However, mutations that abolished polar flagellum production also inhibited lateral flagella expression. We conclude that Aeromonas lateral flagella: (i) play a role in adherence and biofilm formation; (ii) are distinct from the polar flagellum; (iii) synthesis is dependent upon the presence of a polar flagellum filament; and (iv) that the motor proteins of the polar and lateral flagella systems appear to be shared.

Aeromonas↗

Septal-lateral annular cinching abolishes acute ischemic mitral regurgitation.

OBJECTIVE: Ring annuloplasty prevents acute ischemic mitral regurgitation in sheep, but it also abolishes normal mitral annular and posterior leaflet dynamics. We investigated a novel surgical approach of simple septal-lateral annular cinching with sutures to treat acute ischemic mitral regurgitation. METHODS: Nine adult sheep underwent implantation of multiple radiopaque markers on the left ventricle, mitral anulus, and mitral leaflets. A septal-lateral transannular suture was anchored to the midseptal mitral anulus and externalized to a tourniquet through the midlateral mitral anulus and left ventricular wall. Open-chest animals were studied immediately postoperatively. Acute ischemic mitral regurgitation was induced by means of proximal left circumflex artery snare occlusion, and 3 progressive steps of septal-lateral annular cinching (each 2-3 mm suture tightening for 5 seconds) were performed with the transannular suture. Biplane videofluoroscopy for 3-dimensional marker coordinates and transesophageal echocardiography were performed continuously before and during left circumflex ischemia and septal-lateral annular cinching. RESULTS: Acute left circumflex ischemia caused ischemic mitral regurgitation (+0.5 +/- 0.4 [baseline] vs +2.0 +/- 0.7 [ischemia]; P =.005; scale, +0-4), which decreased progressively with each step of septal-lateral annular cinching and was eliminated during the third step (ischemic mitral regurgitation, +0.6 +/- 0.5; P = not significant vs baseline). The third step of septal-lateral annular cinching decreased the septal-lateral diameter by 6.0 +/- 2.6 mm (P =.005); however, mitral anulus area reduction (8.5% +/- 1.0% and 6.9% +/- 1.9% for ischemic mitral regurgitation and septal-lateral annular cinching step 3, respectively; P =.006) and posterior leaflet excursion (50 degrees +/- 9 degrees and 44 degrees +/- 11 degrees for regurgitation and annular cinching step 3, respectively; P =.002) throughout the cardiac cycle were affected only mildly. Normal mitral annular 3-dimensional shape was maintained with septal-lateral annular cinching. CONCLUSIONS: Isolated 22% +/- 10% reduction in mitral annular septal-lateral dimension abolished acute ischemic mitral regurgitation in normal sheep hearts while allowing near-normal mitral annular and posterior leaflet dynamic motion. Septal-lateral annular cinching may represent a simple method for the surgical treatment of ischemic mitral regurgitation, either as an adjunctive technique or alone, which helps preserve physiologic annular and leaflet function.

Acute Disease↗

Lateralizing semiology predicts the seizure outcome after epilepsy surgery in the posterior cortex.

Compared with temporal or frontal resections, epilepsy surgery in the posterior cortex is rarely performed, and the literature concerning clinical predictors for the postoperative seizure outcome in this particular subgroup is sparse. The data of 42 patients with lesional focal epilepsies of the parieto-occipital lobe and the occipital border of the temporal lobe were evaluated retrospectively and related to the seizure outcome 2 years after epilepsy surgery. The investigated parameters included ictal semiology, pre- and postoperative EEG and neuroimaging, histological findings and demographic data. Postoperatively, seizure-free outcome was seen in: (i) 69% of patients with lateralizing auras, but only in 28% of patients without lateralizing auras (P = 0.01); and (ii) 57% of the patients with lateralizing seizures, but only in 17% of patients without lateralizing ictal semiology (P = 0.02). None of the patients with neither lateralizing auras nor lateralizing seizures achieved freedom from seizures (P < 0.01). The proportion of lateralizing seizures (P < 0.01) and auras (P = 0.02) in the total number of recorded seizures and auras was significantly related to the probability of a favourable surgical outcome. No patient with clinical lateralizing signs to the non-lesional hemisphere but 58% without such "false" lateralization achieved freedom from seizures (P = 0.02). The following parameters also proved to be predictive for a favourable seizure outcome: (i) tumoural aetiology; and (ii) absence of epileptiform discharges in the postoperative EEG. The presence and frequency of ictal semiology lateralizing to the lesional hemisphere and the absence of lateralizing signs to the non-lesional hemisphere are highly predictive of a favourable outcome after surgical treatment of epilepsy in the posterior cortex.

Adolescent↗

Increased density of gutta-percha using a controlled heat instrument with lateral condensation.

The purpose of this study was to compare quantitatively the density of standard cold lateral gutta-percha condensation and warm lateral gutta-percha condensation using the System B heating instrument in a low-heat warm lateral condensation technique in an artificial root canal in vitro. Thirty-degree simulated root canals in 30 transparent acrylic blocks were instrumented using Gates-Glidden burs and Quantec (NT Company, Chattanooga, TN) rotary files. The canals were then obturated with gutta-percha using standard cold lateral condensation without sealer. Warm lateral condensation without sealer using the System B instrument at 101 degrees C was then performed on the same 30 canals. A second treatment of warm lateral condensation was then applied to these same canals. The blocks were weighed after the initial canal preparation and after each obturation treatment. Results showed warm lateral condensation of gutta-percha using the System B resulted in a significant increase in density by weight when compared with standard cold lateral condensation. A 23.97% increase in weight was realized after the first heat application, compared with standard lateral condensation. A second heat application produced an additional 2.59% increase in weight over that produced by the first heat application. Data were analyzed using a t test for repeated measures. Both increases were statistically significant (p < 0.001). Warm lateral condensation using the System B instrument results in denser gutta-percha fills by weight when compared with standard cold lateral condensation.

Acrylic Resins↗

Vascularity of the lateral calcaneal flap: a cadaveric injection study.

OBJECTIVE: To describe the arterial blood supply of the subcutaneous tissues of the lateral hindfoot and define the relationships between these arteries and the lateral extensile incision used for open reduction and internal fixation of calcaneal fractures. DESIGN: Human cadaveric lower extremity specimens, doubly injected with India ink and latex, were used to demonstrate the location of the arteries of the subcutaneous tissues of the lateral hindfoot. SETTING: Anatomy laboratory. PATIENTS/PARTICIPANTS: Twenty-four randomly obtained, cadaveric elderly lower extremity specimens. INTERVENTION: India ink and then latex were injected into the superficial femoral artery at the level of the inguinal crease after cleansing of the arterial system. Transtibial amputation specimens were manually debrided of the skin and chemically debrided of subcutaneous tissues with sodium hypochlorite to demonstrate the arterial supply to the soft tissues of the lateral hindfoot. MEAN OUTCOME MEASUREMENTS: The location of the three major arteries was determined relative to the lateral malleolus. The proximity of these vessels to the typical extensile lateral incision was determined radiographically with vascular clips applied along each artery and skin staples placed along the path of the typical skin incision. RESULTS: Three arteries, the lateral calcaneal artery, the lateral malleolar artery, and the lateral tarsal artery, were consistently found along the lateral aspect of the hindfoot. The lateral calcaneal artery appeared to be responsible for the majority of the blood supply to the corner of the flap and, because of its proximity to the vertical portion of the typical incision, it appeared most likely to be injured from inaccurate placement of the incision. CONCLUSIONS: The development of wound complications following open reduction and internal fixation of the calcaneus is multifactorial. Disruption of the blood supply to the surgically created flap may play a larger role in the development of wound complications than previously thought. An understanding of the local vascular anatomy may decrease the rate of wound complications during the operative treatment of intraarticular calcaneal fractures.

Aged↗

Mechanical comparison of endosteal substitution and lateral plate fixation in supracondylar fractures of the femur.

OBJECTIVE: To assess for improved rigidity with the addition of a medial endosteal plate to laterally plated supracondylar femoral fractures. DESIGN: A randomized paired study in a supracondylar femoral fracture model comparing two fixation methods tested cyclically in axial and torsional loading. METHODS: One-centimeter supracondylar gap osteotomies were created in twenty synthetic femurs approximately six centimeters proximal to the knee joint. Ten were stabilized with a lateral eight-hole buttress plate alone, and ten were secured by a similar lateral buttress plate plus a medial endosteal eight-hole dynamic compression plate. Group 1 (n = 5; lateral plate alone) and Group 2 (n = 5; lateral and endosteal plates) were axially loaded up to 700 newtons through a materials test system for three cycles. A displacement transducer detected movement at the medial fracture gap. Group 3 (n = 5; lateral plate alone) and Group 4 (n = 5; lateral and endosteal plates) were tested in torsion. A rod-and-pulley system created an external rotation torque up to twenty Newton-meters for three cycles. A rotary potentiometer measured angular displacement. RESULTS: Lateral buttress plating with endosteal substitution showed statistically significant decreased motion at the fracture site in torsional (p < 0.004) and axial loading (p < 0.0001) versus lateral buttress plating alone using Student's t test. CONCLUSION: The addition of a 4.5-millimeter endosteal plate to a lateral buttress plate provides significantly increased stability, as compared with lateral plating alone in a femoral supracondylar fracture model during simulated axial and torsional loading. Neither fixation construct, however, restored the torsional stability of the distal femur to its preinjury (intact) level.

Biomechanical Phenomena↗

Sagittally oriented fractures of the lateral masses of the cervical vertebrae.

Lateral flexion of the cervical spine may cause a sagittally oriented fracture of the lateral mass with shearing of all or part of the lateral mass away from the vertebral body. We report 22 patients with 24 sagittal fractures of the cervical lateral masses. Cross-table lateral roentgenograms suggested the presence of a sagittal lateral mass fracture in two thirds of the cases based upon malalignment or widening of the facet joints, displaced fracture fragments, subluxation of the spine, or rotation of the spine above the level of abnormality. However, the cross-table lateral roentgenogram was normal in one third of cases. Oblique roentgenograms were available in eight cases; these were positive in five, equivocal in one, and negative in two. Visible fracture lines, often associated with lateral displacement of part or all of the lateral mass, allowed all 24 fractures to be detected on the supine anteroposterior view films. Sagittal lateral mass fractures were unstable in 59% (13/22) of the cases; neurologic deficits, including quadriplegia, hemiplegia, and radiculopathy, were present in 45% (10/22). Computed tomography and complex-motion tomography were useful in confirming the sagittal lateral mass fracture and in detecting other associated fractures.

Adult↗

Lateral approach to intraorbital lesions: anatomic and surgical considerations.

OBJECTIVE: We present our microsurgical lateral orbital approach for intraorbital lesions, with special emphasis on the microanatomy of the orbit. METHODS: Among 26 patients, such lesions included tumors of the lacrimal glands, cavernous angioma, meningioma, neuroma, and other tumors. These intraorbital lesions were removed through a 35- to 40-mm lateral skin incision, and this was followed by lateral orbitotomy featuring a microsurgical dissecting technique. If it was necessary to gain access to the deep lateral portion of the muscle cone, the lateral orbitotomy was extended to the anterior temporal dura. There are two microsurgical routes into the muscle cone, one above and the other below the lateral rectus muscle. The structures encountered along these two routes were demonstrated in an anatomic study of the orbit in cadavers. RESULTS: Lesions located in the lateral compartment of the orbit could be exposed through lateral orbitotomy and were completely removed in most cases. Complications in our series of 26 patients included one case of postoperative visual impairment, one case of tonic pupil, and three cases of transient impairment of eye movement. CONCLUSION: We think that, with an intimate understanding of the anatomy of the orbit, intraorbital lesions located in the lateral compartment of the orbit, and even those in the lateral apex, can be safely removed through lateral orbitotomy.

Adult↗

A comparison of pedicle and lateral mass screw construct stiffnesses at the cervicothoracic junction: a biomechanical study.

STUDY DESIGN: Biomechanical comparison of five different posterior cervicothoracic junction (C7-T1) fixation constructs in a cadaveric model. OBJECTIVES: To determine whether augmenting C7 lateral mass screws with spinous process wires or additional fixation in the C6 lateral mass can create constructs of similar normalized stiffness to that of C7 pedicle screws. SUMMARY OF BACKGROUND DATA: Cervical pedicle screws are known to provide excellent fixation but are potentially dangerous and technically demanding to insert. Lateral mass screws are safer and easier to insert but have less pullout strength and must often be short at C7. METHODS: Twelve cadaveric cervicothoracic specimens (C5-T2) were randomly assigned to one of three experiments: Experiment A (Part 1 and Part 2), Experiment B, and Experiment C (Part 1 and Part 2) (n = 4 each for each experiment). First, the intact specimens were biomechanically tested according to a seven-part loading protocol. The specimens were then destabilized, and then restabilized with the following constructs in conjunction with bilateral T1 pedicle screws and biomechanically tested again using the same seven-part biomechanical protocol as was applied to the intact specimens. Experiment A: Part 1: lateral mass screw fixation at C7 (C7LM); then Part 2: retested after augmentation with triple wiring (C7LM+W). Experiment B: pedicle screw fixation at C7 (C7PS). Experiment C: Part 1: C6 and C7 lateral mass screws (C6C7LM); then Part 2: retested after augmentation with triple wiring (C6C7LM+W). Thus, five different constructs were biomechanically compared in these three experiments. RESULTS: None of the lateral mass constructs demonstrated a significant increase in normalized stiffness when augmented with wiring in any mode of testing. In axial compression, the C7PS construct showed significantly higher (P < 0.001) normalized stiffness than any of the other four constructs. In extension, there were no significant differences among any of the five constructs. Inflexion, right/left lateral bending and right/left axial torsion, the C7PS construct again showed significantly higher normalized stiffness (P < 0.05) than lateral mass fixation at C7 alone. However, in these five modes of testing, the addition of a secondary point of lateral mass fixation at C6 (C6C7LM) produced a construct with a normalized stiffness similar to that of C7PS with no significant difference (P > 0.05). CONCLUSION: C7 pedicle screw fixation provides the construct with the highest normalized stiffness for stabilizing the cervicothoracic junction. If C7 pedicle fixation is not possible, then performing two-level lateral mass fixation at C6 and C7 will achieve a construct with similar normalized stiffness except in axial compression. The addition of triple wiring to the spinous processes does not significantly increase lateral mass construct normalized stiffness.

Aged↗

Potential prognostic benefit of lateral pelvic node dissection for rectal cancer located below the peritoneal reflection.

OBJECTIVE: To identify the parameters related to the effective selection of patients who could receive prognostic benefit from lateral pelvic node dissection. BACKGROUND: Accurate preoperative diagnosis of lateral nodal involvement (LNI) remains difficult, and the indications for lateral lymph node dissection have been controversial. PATIENTS AND METHODS: A total of 244 consecutive patients who underwent potentially curative surgery with lateral dissection for advanced lower rectal cancer (1985-2000) were reviewed. Patients were stratified into groups based on various parameters, and the therapeutic value index for survival benefit was compared among groups. The therapeutic index of lateral dissection was calculated by multiplying the frequency of metastasis to the lateral area and the cancer-related 5-year survival rate of patients with metastasis to the lateral area, irrespective of metastasis to other areas (mesorectal, superior rectal artery [SRA], and inferior mesenteric artery [IMA] areas). RESULTS: LNI was observed in 41 patients (17%); and 88% of them had nodal involvement in the region along the internal iliac/pudendal artery or in the obturator region ("vulnerable field"). The cancer-related 5-year survival rate among the patients with LNI was 42%; the therapeutic index for lateral dissection was calculated as 7.0 patients, which was much higher than that of lymphadenectomy of the SRA area (1.6 patients) and the IMA area (0.4 patients), and almost comparable to that of lymphadenectomy of the upward mesorectal area (6.9 patients). Although it was possible to select groups at high and low risk for LNI based on several parameters related to tumor aggressiveness, such as tumor differentiation in biopsy specimens, the therapeutic value index was not significantly different between these groups. Unlike these parameters, the diameter of the largest lymph node in the "vulnerable field," which was positively correlated with the rate of LNI but irrelevant to the prognosis, was able to successfully stratify patients by therapeutic index. CONCLUSIONS: Advanced lower rectal cancer patients having LNI in the lateral pelvic area are likely to receive prognostic benefit from lymphadenectomy. The most efficient means of determining the effectiveness of lateral dissection preoperatively is to estimate the nodal diameter in the "vulnerable" lateral regions by diagnostic imaging.

Disease-Free Survival↗

Scaphopisocapitate alignment: criterion to establish a neutral lateral view of the wrist.

PURPOSE: To determine whether a "true" neutral lateral view of the wrist is necessary for accurate capitolunate angle measurement, to compare two standards of diagnostic adequacy for neutral lateral wrist views (distal radioulnar overlap [RUO] and scaphopisocapitate [SPC] relationship), and to confirm positional reproducibility and measurement precision of the SPC criterion. MATERIALS AND METHODS: Capitolunate angles were measured on neutral lateral and supine pisotriquetral views of 10 normal wrists. Two hundred neutral lateral wrist views were classified by each standard (RUO and SPC) as excellent, acceptable, or unacceptable. In two subgroups, capitolunate angles were measured on the lateral views to determine SPC practicality and sensitivity. RESULTS: Compared with neutral lateral positioning, supinated off-lateral views showed an apparent increase in lunate dorsiflexion of up to 30 degrees. Diagnostically unacceptable, excellent, and acceptable pronosupination was present on 118, 22, and 60 of 200 views by using the RUO criterion and on 40, 79, and 81 of 200 views by using the SPC criterion, respectively. The capitolunate angle did not show a significant difference between each of the two subgroups (P > .05). CONCLUSION: A true neutral lateral view of the wrist is necessary for accurate measurement of the capitolunate angle on the basis of a comparison with off-lateral views. SPC relationship provides a diagnostically reproducible standard for a neutral lateral wrist view and should reduce the need for repeat lateral radiographs.

Adult↗

Lateral visual pathway of giant barnacle.

1. We have studied the responses to light, conduction down the axons, and anatomical projections of the photoreceptors of the lateral eye in the giant barnacle, Balanus nubilus. By recording intracellularly from ganglion cells that respond to visual input, we have described convergence of the lateral and median visual pathways. 2. Each lateral eye contains three photoreceptor cells, two large and one small. Cobalt filling of single large lateral receptor axons demonstrated that they end in a restricted ovoid bush on the ipsilateral side of the ganglion in approximately the same region in which the median receptors arborize. 3. The lateral receptors have dark resting potentials and responses to light similar to those previously described for the receptors of the median eye. Like the median receptors, the lateral receptors conduct visual signals decrementally, although their axons may be twice as long (14-25 mm). 4. Passing current of either polarity into either of the large receptors produced no detectable voltage change in the other cell. Action potentials elicited in either cell by stimulating it in the presence of tetraethylammonium ion were not detected in the other cell. Light-induced membrane noise in one cell did not correlate with noise in the other. Thus, like the receptors of the median eye, the large receptors of the lateral eye are not electrically coupled. 5. By shadowing each ocellus individually, we have shown that the signals from the median and lateral photoreceptors converge at the level of the second-order cells described for the median pathway. Shadowing the median or a lateral eye gave rise to synergistic responses in second-, third-, and all higher order ganglion cells studied. No cells were found that were driven solely by the lateral eyes. Thus, the lateral and median visual pathways are highly convergent.

Animals↗