Indications for neck dissection in carcinoma of the lip

In the past, neck dissections have been recommended only when nodes were clinically palpable or when they became so. A retrospective ten year study of thirty-seven patients with carcinoma of the lip and with an unusually high mortality has allowed reevaluation of indications for neck dissection. (1) Ten of thirty-seven patients died of this disease and nearly all of the ten died with and because of regional metastases. (2) Seven patients with nonpalpable nodes initially had nodal metastases later which, despite neck dissection at that later time, proved lethal. (3) Two patients who, despite nonpalpable nodes, had undergone neck dissections and were found to have occult bilateral nodal metastases were effectively cured with early neck dissection. This suggests that early bilateral supraomohyoid neck dissections for small carcinomas of the lip and ipsilateral radical neck dissections for large primaries may yield higher cure rates than currently achieved.     

Electromyographic (EMG) amplitude patterns in the proximal and distal compartments of the cat semitendinosus during various motor tasks

The electromyographic (EMG) signals recorded from the proximal (STp) and distal (STd) compartments of the cat semitendinosus muscle (ST) during treadmill running at various speeds, jumping and paw-shaking were quantified to assess the degree of independence of neural control of the two portions of the muscle. Five adult cats were implanted with intramuscular electrodes in the STp and STd. Raw EMG signals were sampled, rectified and a modified form of their running average was used to calculate the mean EMG every 20 ms. EMG amplitudes of each portion of the muscle were plotted and their relative density distributions were generated. The relative density distribution was used to represent a measure of the probability of any two amplitudes occurring simultaneously (i.e. joint probability density distribution). Based on the probability density distributions of the EMG signals from different movements, the patterns of recruitment from the STp and STd were similar. However, during jumping and paw shaking, two relatively vigorous tasks, some deviations in the pattern were apparent. These data, therefore, suggest that the two ends of the ST are subjected to similar, but not identical, control mechanisms during the motor tasks studied.     

The molecular basis for toxicity of surfactants in surgical wounds. 1. EO:PO block polymers

The purpose of this study was to ascertain how molecular variations in a homologous series of polymeric nonionic surfactants affect their tissue toxicity. The results of these structure-toxicity studies serve to identify nontoxic surfactants for use in surgical scrub solutions. Structure-toxicity studies were undertaken with a family of nonionic surfactants, Pluronic polyols, whose composition can be easily altered to form an almost unlimited number of nonionic surfactants. Pluronic polyols are a series of block copolymers that consist of water-soluble poly (oxyethylene) groups at both ends of a water-insoluble poly (oxypropylene) chain. Pluronic polyols of varying molecular weight with a wide range of ethylene oxide content were used for this study. The effect of topical application of solutions of Pluronic polyols on the wound's resistance to infection was used as a measure of toxicity.The molecular weight of the Pluronic polyol was found to be an unimportant determinant of the toxicity of these surfactants in the surgical wounds. The incidence of gross infection in contaminated wounds after the application of a polyol with a high molecular weight differed insignificantly from the infection rate of wounds treated with a polyol with a lower molecular weight. The ethylene oxide content in the Pluronic polyol was an important causal factor of toxicity. Contaminated wounds treated with a polyol with a high ethylene oxide content (80% by weight of total molecule) exhibited a lower incidence of infection than wounds receiving a polyol with a lower ethylene oxide content (20–50% by weight of total molecule). Surfactants with a high ethylene oxide content failed to impair the wound's resistance to infection. The gross infection scores for contaminated wounds treated with the polyols with a high ethylene oxide content differed insignificantly from the incidence of infection of wounds subjected to 0.9% sodium chloride.The use of a nontoxic surfactant has improved the therapeutic value of surgical scrub solutions in the treatment of the contaminated wound. A polyol with a high ethylene oxide content, Pluronic F68, has been utilized with an iodophor, polyvinylpyrrolidone-iodine, in the preparation of a new surgical scrub solution. The therapeutic value of this solution was compared to another surgical scrub solution containing polyvinylpyrrolidone-iodine and an anionic surfactant. The incidence of gross infection after treatment with the mixture of the Pluronic polyol and the iodophor was significantly less than the infection rates of wounds subjected to a surgical scrub solution containing an iodophor and an anionic surfactant. The results of the study provide compelling reasons for further experimental and clinical investigations to assess the potential of this nontoxic surfactant in the treatment of the contaminated wound.     

Auditory capabilities of single-channel cochlear implant patients. Etiologic considerations

The clinical audiometric test results from 53 postlingually deafened adults using the House single-channel cochlear implant were analyzed according to cause of deafness (otosclerosis, ototoxic drugs, meningitis, and trauma). With the exception of one measure, the routine clinical tests did not show a relationship between cause of deafness and performance with the cochlear implant. These findings suggest that, clinically, the single-channel cochlear implant is a viable prosthesis for patients with a wide variety of causes of deafness.     

The Surgical Management of Multiple Lung Metastases

From 1970 to June, 1976, 56 patients who had multiple metastatic tumors of the lung were treated by lung resection. Most of the bilateral lung lesions were removed through a median sternotomy so as to avoid staged bilateral thoracotomy. The surgical mortality was 1.8%. A total of 26 patients are alive at 7 to 69 months (estimated median survival, 20.7 months).Patients with tumor doubling time of less than 40 days had lower survival results (median, 9.5 months), compared to patients with tumor doubling time of more than 40 days (median not yet reached).The type of primary tumor, tumor-free interval, number of lesions removed, and presence of unilateral as opposed to bilateral lung metastases did not seem to affect the therapeutic results.     

Studies in the management of the contaminated wound. IX. Quantitation of the Evans blue dye content of open and primarily closed surgical wounds

The purpose of the present study was to quantitate the changes in the vascular permeability of open and primarily closed wounds after bacterial contamination. Alterations in vascular permeability in tissue were indicated by measuring the content of Evans blue dye in open and primarily closed wounds at different intervals after wounding and contamination. Evans blue dye forms a stable complex with circulating plasma albumin and extravasates through the walls of vessels as they become increasingly permeable.One hour after wounding, the tissue in the clean open wound exhibited a marked increase in dye content when compared with primarily closed wounds not subjected to bacterial contamination. The elevated dye content in the open wound persisted at least seventy-two hours after wounding. Contamination of the open wound with Staph aureus resulted in minimal changes in the content of dye when compared with open wounds not subjected to contamination. In contrast, topical application of Staph aureus to the surface of a wound undergoing primary closure elicited a marked increase in the Evans blue dye content of the primarily closed wound.It is postulated that the increase in Evans blue dye in the clean open wound is a reflection of extravasation into the wound of plasma proteins that form a serous exudate. This accumulation of blood proteins in the open wound may account for its resistance to infection by providing either local lymphatic blockades to bacterial invasion, wound drainage for removal of foreign bodies, antibacterial activity that renders the wound free of bacteria, or all of these factors.     

Lung toxicity of ambient particulate matter from southeastern U.S. sites with different contributing sources: relationships between composition and effects

BACKGROUND: Exposure to air pollution and, more specifically, particulate matter (PM) is associated with adverse health effects. However, the specific PM characteristics responsible for biological effects have not been defined. OBJECTIVES: In this project we examined the composition, sources, and relative toxicity of samples of PM with aerodynamic diameter 相似文献   

Rehabilitative therapies after spinal cord injury

We review some basic and highly relevant concepts in the effort to develop improved rehabilitative interventions for subjects with spinal cord injury (SCI). Interventions that are likely to contribute to improved sensorimotor function include (1) practice of the specific motor task that needs to be improved; and (2) combining the training with one or more interventions--such as pharmacological modulation of the excitability of spinal neural networks, implantation of selected cell types such as olfactory ensheathing glia (OEG), and/or modulation of the excitability of the spinal cord via epidural stimulation. Upon improvement of the neural control of the musculature following SCI, it will always be prudent to maximize the torque output from these activation patterns by assuring that muscle mass is maintained. Therefore, it seems quite feasible that considerable improvement in locomotor performance can be achieved by improved coordination of motor pools, as well as effective recovery of muscle mass, which will assist in the potential generation of normal forces among agonistic and antagonistic muscle groups.