Thoracic and lumbar deformity: rationale for selecting the appropriate fusion technique (Anterior, posterior, and 360 degree)

The rationale of anterior versus posterior, or combined fusion is discussed with regards to different clinical diagnoses and situations. Factors involved in the decision-making process include stability, magnitude of deformity, rigidity of deformity, neurologic considerations, bone quality, and medical/metabolic factors. Careful preoperative assessment and planning are required as well as consideration for the patient's overall well being.     

1997 Volvo Award winner in clinical studies. Degenerative lumbar spondylolisthesis with spinal stenosis: a prospective, randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation

STUDY DESIGN: This prospective study analyzed the influence of transpedicular instrumented on the operative treatment of patients with degenerative spondylolisthesis and spinal stenosis. OBJECTIVES: To determine whether the addition of transpedicular instrumented improves the clinical outcome and fusion rate of patients undergoing posterolateral fusion after decompression for spinal stenosis with concomitant degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: Decompression is often necessary in the treatment of symptomatic patients who have degenerative spondylolisthesis and spinal stenosis. Results of recent studies demonstrated that outcomes are significantly improved if posterolateral arthrodesis is performed at the listhesed level. A meta-analysis of the literature concluded that adjunctive spinal instrumentation for this procedure can enhance the fusion rate, although the effect on clinical outcome remains uncertain. METHODS: Seventy-six patients who had symptomatic spinal stenosis associated with degenerative lumbar spondylolisthesis were prospectively studied. All patients underwent posterior decompression with concomitant posterolateral intertransverse process arthrodesis. The patients were randomized to a segmental transpedicular instrumented or noninstrumented group. RESULTS: Sixty-seven patients were available for a 2-year follow-up. Clinical outcome was excellent or good in 76% of the patients in whom instrumentation was placed and in 85% of those in whom no instrumentation was placed (P = 0.45). Successful arthrodesis occurred in 82% of the instrumented cases versus 45% of the noninstrumented cases (P = 0.0015). Overall, successful fusion did not influence patient outcome (P = 0.435). CONCLUSIONS: In patients undergoing single-level posterolateral fusion for degenerative spondylolisthesis with spinal stenosis, the use of pedicle screws may lead to a higher fusion rate, but clinical outcome shows no improvement in pain in the back and lower limbs.     

Video-assisted thoracoscopic surgery versus open thoracotomy for anterior thoracic spinal fusion. A comparative radiographic, biomechanical, and histologic analysis in a sheep model

STUDY DESIGN: In this in vivo investigation, a sheep model was used to compare the efficacy of a video-assisted thoracoscopic approach and a traditional thoracotomy in promoting a successful interbody spinal arthrodesis. OBJECTIVES: To compare the incidence of successful anterior spinal arthrodesis among three stabilization techniques-iliac crest, Bagby and Kuslich device, and Z-plate--performed using a video-assisted thoracoscopic approach and conventional open thoracotomy approaches. SUMMARY OF BACKGROUND DATA: A clinical outcome study on open versus endoscopic spinal fusion is not yet available. Moreover, no basic scientific investigations have been conducted to determine whether the success of an endoscopic arthrodesis is comparable to that of a conventional open procedure. METHODS: Fourteen Western Crossbred sheep underwent three identical destabilization procedures at T5-T6, T7-T8, and T9-T10, in which the anterior and middle osteoligamentous columns of the spine were resected, followed by three randomized reconstruction procedures using iliac autograft alone, and Z-plate stabilization with iliac autograft. In seven sheep, the entire destabilization-reconstruction procedure was performed using a video-assisted thoracoscopic surgical approach. In the remaining seven, the procedure was performed by conventional open thoracotomy. RESULTS: Histomorphometric and biomechanical evaluation demonstrated that the video-assisted thoracoscopic approach and open thoracotomy arthrodesis had comparable bone formation and biomechanical properties (P > 0.05). However, the Z-plate fusions, as a group, demonstrated increased flexion-extension stiffness properties and trabecular bone formation compared with the autograft and Bagby and Kuslich device fusions (P < 0.05). CONCLUSIONS: Thoracic interbody spinal fusions performed by thoracoscopy have demonstrated histologic, biomechanical, and radiographic equivalence to those performed by a thoracotomy approach. However, in the endoscopy group, intraoperative complications causing longer operative times, higher estimated blood loss, and increased animal morbidity indicated a substantial learning curve associated with the adoption of this surgical technique.     

Characterization of the rhesus monkey galactocerebrosidase (GALC) cDNA and gene and identification of the mutation causing globoid cell leukodystrophy (Krabbe disease) in this primate

Spreading depression (SD) of electroencephalographic activity is a dynamic wave phenomenon in the central nervous system (CNS). The retina, especially the isolated chicken retina, is an excellent constituent of the CNS in which to observe the dynamic behavior of the SD wave fronts, because it changes its optical properties during a SD attack. The waves become visible as milky fronts on a black background. It is still controversial what the basic mechanistic steps of SD are, but certainly SD belongs to the self-organization phenomena occurring in neuronal tissue. In this work, spiral-shaped wave fronts are analyzed using digital video imaging techniques. We report how the inner end of the wave front, the spiral tip, breaks away repeatedly. This separation process is associated with a Z-shaped trajectory (extension approximately 1.2 mm) that is described by the tip over one spiral revolution (period 2.45+/-0.1 min). The Z-shaped trajectory does not remain fixed, but performs a complex motion across the retina with each period. This is the first time, to our knowledge, that established imaging methods have been applied to the study of the two-dimensional features of SD wave propagation and to obtaining quantitative data of their dynamics. Since these methods do not interfere with the tissue, it is possible to observe the intrinsic properties of the phenomenon without any external influence.     

Lesions of the dorsal spinal cord decrease the duration of contact defensive immobility (animal hypnosis) in the rabbit.

22 male New Zealand albino rabbits received either bilateral dorsal or unilateral dorsolateral spinal cord lesions. The duration and incidence of contact defensive immobility (CDI) were tested in these Ss and in 10 intact controls. Neither of the spinal cord lesions affected the number of CDI inductions, but Ss with lesions of the dorsal spinal cord exhibited significantly shorter durations of CDI than either of the other groups, which did not differ from each other. Results indicate that the somesthetic systems that ascend in the dorsal spinal cord are important for the maintenance, but not the initiation, of CDI. It is suggested that the reduction of excitatory drive to neurons of the reticular zones of the dorsal column nuclei produced by transection of the dorsal spinal cord provides the physical basis for the reduction of CDI duration. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Corpus cavernosum electromyography (CC-EMG): a new technique in the diagnostic work-up of impotence

We have studied cavernous electrical activity in 42 subjects, healthy volunteer controls and groups of impotent patients using a nonspecific electromyographic device (PICO-MENFIS) and a specific one, the SPACE-recorder 7500 designed to achieve electric recordings from the corpora cavernosa. In all of the patients, we detected under basal conditions a mean amplitude of 583 +/- 323 microV, a mean duration of 4.9 +/- 7 s, a mean polyphasicity of 3.5 +/- 1.4. It should be emphasized that a significant reduction of potential amplitudes was recorded after pharmacological stimulation in both the controls and the impotent patients. The healthy controls showed amplitudes significantly higher than the impotent patients after radical cystectomy (715 +/- 141 microV versus 381 +/- 227 microV, p < 0.01). The patients after a "nerve-sparing" radical cystectomy with a mean amplitude similar to the controls (500-700 microV) reacted well to the intracavernous drugs in a high percentage of cases. In our experience, CC-EMG seems to be a reliable method which can pinpoint directly lesions to the cavernous smooth muscle and penile autonomic nerves. It has also been able to assess the effects of stress, anxiety and pain on the erectile mechanisms.     

Parsalmide: a new anti-inflammatory agent. V. Pharmacokinetic and metabolic aspects in the rabbit

The bacterial mutation psuA1, known as (suA) a polarity suppressor, partially relieves all N defects in bacteriophage lambda growth. No evidence is found that psuA1 relieves Q defects in lambda growth. Specific mechanisms of action by the N and Q gene products are discussed. The psuA1 mutation was also found to suppress IS1 type but not IS2 type insertion mutations in lambda.     

Diet for a small primate: insectivory and gummivory in the (large) patas monkey (Erythrocebus patas pyrrhonotus)

A 17 month field study of unprovisioned patas monkeys (Erythrocebus patas pyrrhonotus) in Laikipia, Kenya, using both ad libitum and scan sampling techniques, revealed that the diet of patas monkeys consists primarily of gum of Acacia drepanolobium, arthropods (both free-living and concentrated in the swollen thorns of A. drepanolobium), and other animals. This type of diet is normally found only in smaller-bodied primates. Results from vegetational transects suggest that the larger-bodied patas monkey can subsist on such a diet because gum and arthropods are relatively easily found in their habitat, thereby minimizing search time. Patas monkeys also spend more time moving and less time feeding (while not moving) than other Old World primates. The characteristic long limbs of patas may have evolved in response to feeding on small, nonusurpable, and widely distributed foods, in which access to foods is maximized while time and energy spent in terrestrial travel between food sites are minimized.     

Validation of the MMPI-2 Computerized Adaptive version (MMPI-2-CA) in a correctional intake facility.

Computerized adaptive testing in personality assessment can improve efficiency by significantly reducing the number of items administered to answer an assessment question. The time savings afforded by this technique could be of particular benefit in settings where large numbers of psychological screenings are conducted, such as correctional facilities. In the current study, item and time savings, as well as the test–retest and extratest correlations associated with an audio augmented administration of all the scales of the Minnesota Multiphasic Personality Inventory (MMPI)-2 Computerized Adaptive (MMPI-2-CA) are reported. Participants include 366 men, ages 18 to 62 years (M = 33.04, SD = 10.40), undergoing intake into a large Midwestern state correctional facility. Results of the current study indicate considerable item and corresponding time savings for the MMPI-2-CA compared to conventional administration of the test, as well as comparability in terms of test–retest and correlations with external measures. Future directions of adaptive personality testing are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

分布式系统局域网络技术在太钢生产过程控制中的应用

随着基础自动化，过程控制技术的发展，局域网络作为大规模计算机控制系统的核心，有着广泛的应用和发展前景，介绍了三种局域网络的热连轧，连铸和酸洗机组的应用，并进行了分析评价。     

Behavioral thermoregulation in a sexually and developmentally dichromatic neotropical primate, the black-and-gold howling monkey (Alouatta caraya)

Behavioral thermoregulation in primates may provide a means for the conservation of heat during periods of low ambient temperature and/or food shortage as well as a way to dissipate heat under hot conditions. This article focuses on behavioral thermoregulation in a sexually dichromatic primate, the black-and-gold howling monkey (Alouatta caraya). Two models have been proposed to explain the evolution of sexual dichromatism in this species: thermoregulation and sexual selection. Five hypotheses associated with thermoregulatory behaviors are tested. These are as follows: (1) energy-conserving postures are used mainly under low ambient temperatures; (2) sunny resting places are selected during periods of low temperature; (3) exposure of the less-insulated ventral region to sunlight decreases with increasing temperature; (4) black-colored adult males use energy-conserving postures, sunny places, and exposure of the ventral region to sunlight less frequently than do blonde-colored adult females; and (5) smaller individuals use energy-conserving postures, sunny places, and exposure of the ventral region to sunlight in significantly greater frequency than do larger individuals. Over a 12-month period, behavioral data were collected on a free-ranging habituated group of 15-17 howlers of all age-sex classes. Ambient temperature was measured each hour. The results indicate that during resting, howlers showed a consistent use of heat-conserving postures, showed a preference for sunny places, and exposed their ventral region to sunlight under low ambient temperatures. A preference for shady places, heat-dissipating postures, and exposure of the back were observed under high ambient temperatures. Despite sex differences in adult color patterns and differences in size between age classes, no significant age or sex differences in thermoregulatory behaviors were detected. Failure to confirm a thermoregulation model implies that sexual selection may be responsible for sexual dichromatism in this species.     

Self-esteem and the occupational stress process: Testing two alternative models in a sample of blue-collar workers.

Blue-collar workers (4,506 men and 939 women) participated in a survey comparing 2 alternative models, one assuming the level of self-esteem (SE) to result to a significant extent from the strain induced by occupational stressors and the other stating that the level of SE is a determinant of stressor perception and experienced strain. The results of multiple regression analyses did not support the latter model, whereas the 1st model was partially supported: Monotony was associated with increased strain and decreased SE among younger (≤ 35 yrs) male participants and older (≥ 35 yrs) female participants. These observations were made in the context of psychological strain symptoms but not in the context of physiological strain symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validation of a computerized version of the temperament and character inventory (TCI) in psychiatric inpatients

The thyroid cancer incidence in the Ukraine among those born in the period 1968-1986 was analyzed with the aim to identify the enhancement due to the Chernobyl accident. Since any Ukrainian data referring to the time period before the accident are scarce and the variation of spontaneous incidences in other countries is immense, the Ukrainian incidences in the period 1986-1989 were used to estimate the baseline risk. Following 1990, the incidence in the southern part of the Ukraine increased by about 30%, independent of age. In the other parts the increase of the incidence depended on age at exposure. In the age group of 9-year-old children, the incidences in three regions defined as the 'high-dose area', the northern, and the middle oblasts, increased by factors of 50, 20, and 6, respectively. These rates (1991-1995) are well above spontaneous rates in other countries. In the age group of 17-year-old juveniles, the incidence increased by a factor of 6 for the 'high dose area' and in the three northern oblasts, whereas in the nine 'middle' oblasts it was similar to the incidence of the 'southern' Ukraine. These rates are within the range found in other countries.     

Classical nictitating membrane conditioning in the rabbit (Oryctolagus cuniculus) as a function of unconditioned stimulus locus.

Examined the effects of different placements of electrodes used to present a shock UCS on conditioning the rabbit nictitating membrane response (NMR) in 2 experiments with 32 New Zealand and 24 albino rabbits. Ss were conditioned with shock leads attached either circumorbitally, at the ear base, or at the ear tip. In 1 circumorbital shock group, nictitating membranes of both shocked and unshocked eyes were monitored. Circumorbital, ear base, and ear-tip shock yielded best to poorest performances, respectively, and the shocked membrane yielded better performance than the unshocked one. Analysis of UCR and CR latencies and peak amplitude, as well as slow motion films of responses, suggests that poorer performance resulted from the elicitation of other responses, of which the NMR may have been a secondary or indirect component. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eyeblink conditioning in the rabbit (Oryctolagus cuniculus) with stimulation of the mystacial vibrissae as a conditioned stimulus.

Eyeblink conditioning is a well-understood paradigm for the study of learning and memory and has been successfully employed with the use of auditory and visual conditioned stimuli (CSs). In this study, vibrotactile stimulation of the mystacial vibrissae was examined as an alternative CS in the rabbit ( Oryctolagus cuniculus). The technique is described and acquisition of eyeblink conditioning (EBC) with stimulation of a single row of vibrissae in a delay paradigm is reported. Extinction of EBC with presentation of the CS alone is demonstrated, as well as reacquisition with stimulation of a single whisker. Finally, control experiments ensure that the CS has no auditory components. Ipsilateral presentation of the CS and airpuff is a more effective combination for training than contralateral presentations. Vibrotactile stimulation of the vibrissae as a CS will enable further examination of the neural correlates of learning in a well-characterized sensory system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Primacy and recency effects in rhesus monkeys (Macaca mulatta) using a serial probe recognition task: II. Effects of atropine sulfate.

Nonhuman primates display both a primacy and a recency effect when trained on a 6-item serial probe recognition task. The author has previously shown that, in the rhesus monkey, diazepam (3.2 mg/kg im) interferes with the memory processes that mediate the recency effect without affecting those memory processes involved in the primacy effect (C. A. Castro, 1995). This study assessed the effects of atropine sulfate (0.2, 0.3, and 0.4 mg/kg im) on the primacy and recency effects in these same monkeys. Opposite the effects of diazepam, atropine disrupted the primacy component of the serial position curve and had no measurable effect on the recency component. In addition, the 2 highest doses of atropine disrupted accuracy on the nonmatching probe trials, whereas all 3 doses of atropine resulted in increased response latencies. These reports indicate that the primacy and recency effects in the nonhuman primate can be pharmacologically dissociated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)