The Utility of Intraoperative Neuromonitoring in Pediatric Surgical Oncology

BACKGROUND

Intraoperative nerve monitoring (IONM) is a technique used to decrease the possibility of nerve-associated morbidity and damage to nearby neural structures during complex surgical procedures. The use and potential benefits of IONM in pediatric surgical oncology are not well-described.

METHODS

An overview of the current literature was performed to elucidate the various techniques that may be useful to pediatric surgeons for resection of solid tumors in children.

RESULTS

The physiology and common types of IONM relevant to the pediatric surgeon are described. Important anesthetic considerations are reviewed. Specific applications for IONM that may be useful in pediatric surgical oncology are then summarized, including its use for monitoring the recurrent laryngeal nerve, the facial nerve, the brachial plexus, spinal nerves, and lower extremity nerves. Troubleshooting techniques regarding common pitfalls are then proposed.

CONCLUSION

IONM is a technique that may be beneficial in pediatric surgical oncology to minimize nerve injury during extensive tumor resections. This review aimed to elucidate the various techniques available. IONM should be considered as an adjunct for the safe resection of solid tumors in children in the proper setting with the appropriate level of expertise. A multidisciplinary approach is advised. Additional studies are necessary to further clarify the optimal use and outcomes in this patient population.

LEVELS OF EVIDENCE

Level III.

An overview of behaviour difficulties found in long-term elderly care settings

STUDY OBJECTIVE

To provide an understanding of the nature and prevalence of behaviour difficulties in long-term care facilities, to compare care settings and comment on the appropriateness of the need for specialist care.

DESIGN

Nurses or carers implemented two rating scales in randomly selected settings.

SETTING

Nursing homes, residential homes and NHS elderly long-stay wards.

SUBJECTS

Elderly long-stay patients.

MAIN RESULTS

NHS and nursing home long-term care facilities show similar behaviour difficulties, with nursing homes experiencing more behaviour manifestations in most cases. Residential facilities have behaviour difficulties to a lesser extent.

CONCLUSIONS

Nursing homes have limited formal psychiatric intervention compared to NHS settings. Behaviour difficulties result in increased work for general practitioners and increased hospital referrals. More prospective research is required into the antecedents, effects and treatments of patients with behaviour difficulties in nursing homes. For example, it may be appropriate that specialist input is provided for nursing homes in order to implement behaviour intentions and contribute to the reduction of GP callouts and pharmacological interventions.

Effects of hospital closure on mortality rates of the over-65 long-stay psychiatric population

The closure of this 100-year-old hospital has allowed us to look at the effect on mortality of moving the whole over-65 long-stay population to other settings. Our results confirm that there is a slight excess of deaths during and immediately after these moves, but that there is no longer-term effect on mortality rates.

Rational engineering of the TOL meta-cleavage pathway

The meta-cleavage pathway of Pseudomonas putida mt-2 was simulated using a biochemical systems simulation developed by Regan (1996). A non-competitive inhibition term for catechol-2,3-dioxygenase (C23O) by 2-OH-pent-2,4-dienoate (Ki = 150 μM) was incorporated into the model. The simulation predicted steady state accumulation levels in the μM range for metabolites pre-meta-cleavage, and in the mM range for metabolites post-meta-cleavage. The logarithmic gains L[V-i, Xj] and L[X-i, Xj] clearly indicated that the pathway was most sensitive to the concentration of the starting substrate, benzoate, and the first enzyme of the pathway, toluate-1, 2-dioxygenase (TO). The simulation was validated experimentally; it was found that the amplification of TO increased the steady state flux from 0.024 to 0.091 (mmol/g cell dwt)/h. This resulted in an increased accumulation of a number of the pathway metabolites (intra- and extracellularly), especially cis-diol, 4-OH-2-oxovalerate, and 4-oxalocrotonate. Metabolic control analysis indicated that C23O was, in fact, the major controling enzymic step of the pathway with a scaled control coefficient of 0.83. The amplification of TO resulted in a shift of some of the control away from C23O. Catechol-2,3-dioxygenase, however, remained as the major controling element of the pathway. Copyright 1998 John Wiley & Sons, Inc.

Quantitative autoradiographic evaluation of the influence of protein dose on monoclonal antibody distribution in human ovarian adenocarcinoma xenografts

We studied the effect of monoclonal antibody protein dose on the uniformity of radioiodinated antibody distribution within tumor masses using quantitative autoradiography. Groups (n = 11-13/group) of athymic nude mice with subcutaneous HTB77 human ovarian carcinoma xenografts were injected intraperitoneally with an 125I-labeled anticarcinoma-associated antigen murine monoclonal antibody, 5G6.4 using a high or a low protein dose (500 micrograms or 5 micrograms). At 6 days post-injection the macroscopic and microscopic intratumoral biodistribution of radiolabeled antibody was determined. The degree of heterogeneity of the labeled antibody distribution within each tumor was quantified and expressed as the coefficient of variation (CV) of the activity levels in serial histological sections. Tumors from mice given the 500-micrograms protein doses had substantially lower CV values, 0.327 +/- 0.027, than did tumors from animals given 5-micrograms protein doses, 0.458 +/- 0.041, (P = 0.0078), indicating that the higher protein dose resulted in more homogeneous distribution of radioactivity in tumors than did the lower dose. While the percentage of the injected dose reaching the tumor was comparable between groups, injecting the higher dose of protein resulted in significantly lower tumor to non-tumor uptake ratios than those obtained for the lower protein dose. These data indicate, in this system, that to achieve more uniform intratumoral antibody (and radiation for radioimmunotherapy) delivery, a relatively high protein dose must be administered. However, to obtain this increased uniformity, a substantial drop in tumor/background uptake ratios was seen. Quantitative autoradiographic evaluation of human tumor xenografts is a useful method to assess the intratumoral distribution of antibodies.

Products of cells from gliomas: VIII. Multiple-well immunoperoxidase assay of immunoreactivity of primary hybridoma supernatants with human glioma and brain tissue and cultured glioma cells

To test the feasibility of primary screening of hybridoma supernatants against human glioma tissue, over 5000 combinations of hybridoma supernatants with glioma tissue, cultured glioma cells, and normal central neural tissue were screened with a new multiple-well (M-well) screening system. This is an immunoperoxidase assay system with visual endpoints for screening 20-30 hybridoma supernatants per single microscope slide. There were extensive differences between specificities to tissue and to cultured glioma cells when both were screened with M-wells and when cultured cells were screened with standard semi-automated fluorescence. Primary M-well screening with glioma tissue detected seven hybridoma supernatants that specifically identified parenchymal cells of glioma tissue and that were not detected with cultured cells. Immunoreactivities of individual supernatants for vascular components (nine supernatants), necrosis (five supernatants), and nuclei (three supernatants) were detected. Other supernatants bound multiple sites on glioma tissue and/or subpopulations of neurons and glia of normal tissue. The results show that primary screening with glioma tissue detects a number of different specificities of hybridoma supernatants to gliomas not detected by conventional screening with cultured cells. These are potentially applicable to diagnosis and therapy.

Bioavailability of estradiol as a marker for breast cancer risk assessment

The search for a hormonal marker in breast cancer has centered on estrogens and their metabolites. However, direct measurements of total amounts of these steroids have shown no convincing or consistent differences between normal women and women with breast cancer. The purpose of this study was to measure the percentages of non-protein-bound estradiol (%NPBE) and of estradiol bound to albumin (%ABE) and the levels of sex hormone-binding globulin (SHBG) both in women with breast cancer and in those free of disease. Serum was collected and analyzed within 2 weeks, using an isodialysis method. The mean %NPBE and %ABE were significantly higher in 32 women with breast cancer (1.73 and 64.0%, respectively) than in 32 matched disease-free women (1.43 and 48.6%, respectively) (P less than 0.001). No significant difference was observed in the levels of plasma albumin when the above matched groups were compared. However, plasma levels of SHBG were significantly lower in the women with breast cancer than in either the control population or matched controls. In this finding we differ from previous studies which reported no significant differences in the mean plasma levels of SHBG. In our study, the increased %NPBE and %ABE in some patients with breast cancer may be related to a lower level of plasma SHBG; other factors, too, may affect the distribution of estradiol. Our results support the hypothesis than an increase in %NPBE and %ABE or both may indicate an increased risk of breast cancer.

Chemotherapy in pancreatic cancer: results of a controlled, prospective, randomised, multicentre trial

Forty patients with inoperable pancreatic cancer were included in a prospective, randomised, controlled trial of multiple chemotherapy. The survival of 19 untreated control patients was compared with that of 21 patients who received an initiation course of intravenous fluorouracil, cyclophosphamide, methotrexate, and vincristine given over five days followed by intravenous fluorouracil and mitomycin given over three or five days at six-week intervals thereafter. Median survival in treated patients was 44 weeks, which was significantly longer than the nine weeks seen in controls. In patients without metastases median survival was 48 weeks in the treated group and 12 weeks in controls. In patients with metastases it was 30 weeks in treated patients and seven weeks in controls. The treatment was well tolerated and seemed to confer a significant prolongation of survival, comparing favourably with previous reports of chemotherapy with or without radiotherapy. If the results are confirmed this regimen may be useful in district general hospital practice.

Chemotherapy in advanced gastric cancer: a controlled, prospective, randomised multi-centre study

Seventy-six patients with advanced gastric adenocarcinoma were studied in a prospecitive, randmoised, controlled trial using vincristine, methotrexate, cyclophosphamide, and 5-fluorouracil in an initiation course and mitomycin-C with 5-fluorouracil as maintenance therapy. Thirty-seven patients were inoperable and 39 had the primary tumour resected with histological evidence of residual disease. Survival in the inoperable group was short and showed no significant difference between treated and control patients. The median survival times for treated and control groups were 9.5 and 9.0 weeks respectively. In the resected patients there was no difference in ultimate overall survival between the groups but up to 20 weeks there was a suggestion that the probability of survival in treated patients was higher (P = 0.06). The patients were well-matched and it is concluded that chemotherapy has had an early effect but that a further trial with more detailed stratification, particularly of staging and histological grade, is needed. No patient received treatment for longer than two years and unacceptable toxicity occurred in only two patients. Nausea occurred more frequently in the treated group but was short-lived and clinically manageable.