"Weight loss preoccupation in aging women": a review

Preoccupation with body weight leading to frequent dieting has been found to be common in young women of developed countries. Little is known however about body image preoccupation or the prevalence of dieting for weight control purposes in elderly women. The few available reports suggest that preoccupation with weight remain high in elderly women and that pressure to be thin drives normal weight older women to recurrent dieting. After a reminder of the nutritional vulnerability of the elderly recommendations to the health care professionals and health authorities are provided. An increased awareness of eating habits and weight preoccupation in elderly women is needed, since attitudes towards weight may influence the effectiveness of medical advice and health promotion campaigns.

Awake craniotomy for removal of intracranial tumor: considerations for early discharge

We retrospectively reviewed the anesthetic management, complications, and discharge time of 241 patients undergoing awake craniotomy for removal of intracranial tumor to determine the feasibility of early discharge. The results were analyzed by using univariate analysis of variance and multiple logistic regression. The median length of stay for inpatients was 4 days. Fifteen patients (6%) were discharged 6 h after surgery and 76 patients (31%) were discharged on the next day. Anesthesia was provided by using local infiltration supplemented with neurolept anesthesia consisting of midazolam, fentanyl, and propofol. There was no significant difference in the total amount of sedation required. Overall, anesthetic complications were minimal. One patient (0.4%) required conversion to general anesthesia and one patient developed a venous air embolus. Fifteen patients (6%) had self-limiting intraoperative seizures that were short-lived. Of the 16 patients scheduled for ambulatory surgery, there was one readmission and one unanticipated admission. It may be feasible to discharge patients on the same or the next day after awake craniotomy for removal of intracranial tumor. However, caution is advised and patient selection must be stringent with regards to the preoperative functional status of the patient, tumor depth, surrounding edema, patient support at home, and ease of access to hospital for readmission.

IMPLICATIONS

It may be feasible to perform awake craniotomies for removal of intracranial tumor as an ambulatory procedure; however, caution is advised. Patient selection must be stringent with respect to the patient's preoperative functional status, tumor depth, surrounding edema, patient support at home, and ease of access to hospital for readmission.

Biological aspects of neuroblastomas identified by mass screening in Quebec

BACKGROUND

Neuroblastoma has several characteristics that suggest that preclinical diagnosis might improve outcome. Therefore, the Quebec Neuroblastoma Screening Project was undertaken from 1989 to 1994 to examine infants at 3 weeks and 6 months by measuring urinary catecholamine metabolites.

PROCEDURE

Over the 5-yr period, 45 tumors were detected by screening, 20 were identified clinically prior to the third week, and 64 were identified clinically at a later time. We analyzed available tumors for Shimada histopathology, tumor ploidy, MYCN copy number and serum ferritin.

RESULTS

Of the tumors detected by screening, only 2 of 45 tested had unfavorable histology, 2 of 45 had diploid or tetraploid DNA content, 0 of 43 had MYCN amplification, and 4 of 44 had elevated serum ferritin. All of these patients are alive and well. The 20 patients detected prior to the 3-week screen had similar biological characteristics. In contrast, of the patients detected clinically after 3 weeks of age, 19 of 51 testedhad unfavorable histology, 25 of 66 had diploid or tetraploid tumors, 12 of 56 had MYCN amplification, and 14 of 54 had elevated ferritin.

CONCLUSIONS

The difference between the screened and clinically detected cases was highly significant for each biological variable. Preliminary data on other biological variables, such as neurotrophin expression and allelic loss on 1 p in these patients are consistent with the above findings. These data suggest that mass screening for neuroblastoma at or before 6 months of age detects almost exclusively tumors that have favorable biological characteristics, many of which might have regressed spontaneously. Thus, continued mass screening for neuroblastoma at 6 months is unlikely to accomplish its intended goal, and should probably be discontinued.

A phase I study of irinotecan in pediatric patients: a pediatric oncology group study

A Phase I trial of irinotecan was performed to determine the maximum tolerated dose (MTD), the dose-limiting toxicities (DLTs), and the incidence and severity of other toxicities in children with refractory solid tumors. Thirty-five children received 146 courses of irinotecan administered as a 60-min i.v. infusion, daily for 5 days, every 21 days, after premedication with dexamethasone and ondansetron. Doses ranged from 30 mg/m2 to 65 mg/m2. An MTD was defined in heavily pretreated and less-heavily pretreated (i.e., two prior chemotherapy regimens, no prior bone marrow transplantation, and no radiation to the spine, skull, ribs, or pelvic bones) patients. Myelosuppression was the primary DLT in heavily pretreated patients, and diarrhea was the DLT in less-heavily pretreated patients. The MTD in the heavily pretreated patient group was 39 mg/m2, and the MTD in the less-heavily pretreated patients was 50 mg/m2. Non-dose-limiting diarrhea that was well controlled and of brief duration was observed in approximately 75% of patients. A partial response was observed in one patient with neuroblastoma, and in one patient with hepatocellular carcinoma. Stable disease (4-20 cycles) was observed in seven patients with a variety of malignancies including neuroblastoma, pineoblastoma, glioblastoma, brainstem glioma, osteosarcoma, hepatoblastoma, and a central nervous system rhabdoid tumor. In conclusion, the recommended Phase II dose of irinotecan administered as a 60-min i.v. infusion daily for 5 days, every 21 days, is 39 mg/m2 in heavily treated and 50 mg/m2 in less-heavily treated children with solid tumors.

Treatment efficacy is not an index of pain intensity

PURPOSE

To determine if the efficacy of pain treatment assessed by the patient is a valid indicator to evaluate pain management.

METHODS

Three hundred and ninety one adult patients were investigated on the day of surgery and on the two following days after intraperitoneal or orthopedic surgery. Pain scores and efficacy of pain treatment were evaluated using ungraduated visual analog scales (VAS). According to the evolution of pain between two consecutive days, patients were classified as having "worse pain", "same pain" or "lower pain".

RESULTS

During the first time interval, pain treatment was considered effective by 42% of patients with worse pain, compared with 55% with less pain (OR= 1.9, 95% CI=1.1-3.7) and to 58% of patients with the same pain (OR =2.0, 95%CI=1.2-3.0). During the second time interval, these proportions were: 46% (worse pain), 63% (lower pain vs worse: OR= 1.8, 95%CI= 1.0-3.2) and 66% (same pain vs worse: OR=2.1, 95%CI=1.1-4.1). Using pain evolution as a"gold standard", patient assessment of pain treatment efficacy had sensitivity of 0.55 and specificity 0.5 during the first time interval, and of 0.63 and 0.43 during the second time interval.

CONCLUSION

Patient evaluation of the efficacy of pain treatment can mislead the clinician about the severity of pain. Patients tend to be satisfied with pain treatment, even when pain is not relieved. The relation of intensity of pain to patient perception of treatment efficacy is weak.

Quality of life in patients with glioblastoma multiforme participating in a randomized study of brachytherapy as a boost treatment

OBJECT

Until recently the assessment of outcome in patients treated for glioma has emphasized length of survival with the evaluation of quality of life (QOL) limited to unidimensional, mostly physical, measures. The authors report the multidimensional assessment of QOL as part of a randomized clinical trial of brachytherapy as a boost in the initial treatment of patients with glioblastoma multiforme.

METHODS

A questionnaire previously developed by the senior authors and psychometrically validated was completed by patients on randomized entry into the study and at follow-up review every 3 months thereafter. The questionnaire was presented in a linear-analog self-assessment format. Karnofsky Performance Scale (KPS) scores were also recorded on each occasion. No differences were found between patients in either arm of the study (conventional radiation therapy consisting of 50 Gy in 25 fractions or conventional radiation plus a brachytherapy boost of a minimum peripheral tumor dose of 60 Gy) in KPS and QOL scores during the 1st year of follow-up review. However, there was a statistically significant deterioration in patients' overall KPS scores during the 1st year of follow up compared with baseline scores. Of QOL items evaluated, statistically significant deteriorations were found in self care, speech, and concentration, and on subscale analyses, cognitive functioning and physical experience (symptoms) deteriorated significantly during the 1st year of follow up, compared with baseline values. The correlation between QOL and KPS scores was low.

CONCLUSIONS

Future studies in patients harboring malignant gliomas must incorporate measures assessing QOL because traditional measures focusing on physical or neurological functioning give an incomplete assessment of the patient's experience.

Practice parameters for the management of single brain metastasis

Object

In January 1998 the Guidelines and Outcomes Committee of the American Association of Neurological Surgeons (AANS) issued a charge for the development of evidence-based practice parameters focusing on the treatment of patients with single metastasis to the brain. The charge was imposed in response to the significant controversy surrounding questions relating to the optimal management strategies for patients with single brain metastasis.

Methods

A team consisting of physicians from the AANS, the American Academy of Neurology, and the American Association of Therapeutic Radiation Oncology convened and the literature was reviewed. Methodically drawing from the best of Class I, II, and III levels of available evidence, authors sought to determine how the literature addressed and disposed of the question of the optimal management for an adult with a known history of cancer and a single meta-static brain lesion. Framing the question in this specific manner allowed researchers to focus directly on treatment issues, without having to consider diagnostic issues.

Conclusions

The results of the evidence-based analysis demonstrated that there was insufficient information to establish standards of care. Data from the literature does, however, support a guideline stating that surgical resection accompanied by whole brain radiation therapy is associated with the best survival rate. Additional lower-quality evidence supports an option for management with radiosurgery.

Phase II trial of pyrazoloacridine in children with solid tumors: a Pediatric Oncology Group phase II study

PURPOSE

Pyrazoloacridine (PZA), a rationally synthesized deoxyribonucleic acid (DNA) binding agent that preferentially inhibits ribonucleic acid rather than DNA synthesis, is active against hypoxic and noncycling tumor cells and has greater in vitro activity against a broad range of human solid tumor lines than against the L1210 murine leukemia line. The Pediatric Oncology Group conducted a phase II study to determine the activity of PZA administered as a 3-hour infusion.

PATIENTS AND METHODS

The activity of PZA was evaluated in patients with a variety of childhood solid tumors including rhabdomyosarcoma, Ewing sarcoma/peripheral neuroectodermal tumor, neuroblastoma, osteogenic sarcoma, Wilms tumor, or other solid tumors (excluding brain tumors). In addition to a standard three-stage design to test the drug's activity in each tumor type, a global stopping rule was used such that if no complete or partial responses (CR or PR) occurred in the first 35 patients (pooled across all strata except "other"), the study would be closed.

RESULTS

A total of 47 patients were entered into the study. Myelosuppression was the primary toxicity. Severe nonhematologic toxicity was uncommon. Only one patient exhibited grade 3 neurologic toxicity (anxiety). No CRs or PRs were observed.

CONCLUSION

Use of the global stopping criterion permitted early identification of lack of activity of PZA against childhood solid tumors.

Severe necrotizing mastopathy caused by calciphylaxis alleviated by total parathyroidectomy

Calciphylaxis is a complication caused by secondary hyperparathyroidism in patients with chronic renal failure. These patients may present with clinical findings of ischemic necrosis involving the skin and muscle resulting in subsequent gangrene and vascular calcifications. We report a rare case of necrotizing mastopathy caused by calciphylaxis in a 70-year-old female with end-stage renal disease whose symptoms resolved with a total parathyroidectomy.

Imaging neuronal subsets in transgenic mice expressing multiple spectral variants of GFP

We generated transgenic mice in which red, green, yellow, or cyan fluorescent proteins (together termed XFPs) were selectively expressed in neurons. All four XFPs labeled neurons in their entirety, including axons, nerve terminals, dendrites, and dendritic spines. Remarkably, each of 25 independently generated transgenic lines expressed XFP in a unique pattern, even though all incorporated identical regulatory elements (from the thyl gene). For example, all retinal ganglion cells or many cortical neurons were XFP positive in some lines, whereas only a few ganglion cells or only layer 5 cortical pyramids were labeled in others. In some lines, intense labeling of small neuronal subsets provided a Golgi-like vital stain. In double transgenic mice expressing two different XFPs, it was possible to differentially label 3 neuronal subsets in a single animal.

"Low-tech" personal emergency response systems reduce costs and improve outcomes

A relatively inexpensive low-technology solution can be used by managed care organizations (MCOs) to improve outcomes and significantly reduce health care costs among community-residing elderly patients. Clinical studies indicate that usage of monitored Personal Emergency Response Systems (PERS) reduce mortality rates by nearly four times, reduce hospital utilization by 59 percent, and yield a positive benefit-to-cost ratio of over seven to one (every dollar spent on PERS results in $7.19 in health care cost savings).

Involution of diencephalic pilocytic astrocytoma after partial resection. Report of two cases in adults

Spontaneous involution of pilocytic astrocytoma has been reported in children, particularly in those with neurofibromatosis Type 1. However, this rare occurrence has not been documented in adults. In this report the authors describe two cases of adults with pilocytic astrocytoma. One patient had a tumor in the thalamus and the other in the hypothalamus and optic chiasm; both patients underwent partial resection of the tumor. The initial magnetic resonance (MR) images demonstrated reduction in size of the tumors, and subsequent MR images obtained several months later revealed marked further involution with reduction in size and enhancement. The possible mechanisms for this uncommon occurrence are discussed.

Adenoviral vector-mediated gene transfer: timing of wild-type p53 gene expression in vivo and effect of tumor transduction on survival in a rat glioma brachytherapy model

OBJECTIVE

This study sought to investigate modification of the radiation response in a rat 9L brain tumor model in vivo by the wild-type p53 gene (wtp53). Determination of the timing and dose of radiation therapy required the assessment of the duration of the effect of wtp53 expression on 9L tumors after in vivo transfection.

METHODS

Anesthetized male F-344 rats each were stereotactically inoculated with 4 x 10(4) 9L gliosarcoma cells through a skull screw into the cerebrum in the right frontal region. Twelve-day-old tumors were inoculated through the screw with recombinant adenoviral vectors under isoflurane anaesthesia: control rats with Ad5/RSV/GL2 (carrying the luciferase gene), and study rats with Ad5CMV-p53 (carrying the wtp53 gene). Brain tumors removed at specific times after transfection were measured, homogenized, and lysed and wtp53 expression determined by Western blot analysis. Four groups of nine rats were, subsequently, implanted with iodine-125 seeds 15 days post-tumor inoculation to give a minimum tumor dose of 40 or 60 Gy.

RESULTS

We demonstrated transfer of wtp53 into rat 9L tumors in vivo using the Ad5CMV-p53 vector. The expression of wtp53 was demonstrated to be maximum between days 1 and 3 post-vector inoculation. Tumors expressing wtp53 were smaller than controls transfected with Ad5/RSV/GL2 but this difference was not statistically significant. Radiation made a significant difference to the survival of tumor-bearing rats. Moreover, wtp53 expression conferred a significant additional survival advantage.

CONCLUSION

The expression of wtp53 significantly improves the survival of irradiated tumor-bearing rats in our model.

Modified stereotactic insertion of the Ommaya reservoir. Technical note

Ommaya reservoirs are used primarily for the repeated injection of intrathecal chemotherapy for leptomeningeal metastasis from hematopoietic and solid malignancies. Insertion of this device in a relatively large nondisplaced ventricle is not a difficult task, but challenges arise when the ventricle is small and/or displaced. Different techniques have been developed to overcome this difficulty, most of which include the use of stereotactic frames. Further improvements would be beneficial. The technique described in this paper depends on a stereotactic frame; however, the modification proposed by the authors removes the arc system from the surgical field before the actual surgical procedure is begun. Removal of the arc improves access to the surgical field as well as preparation and draping of the surgical site and minimizes potential breaks in sterile technique, which ultimately reduces the incidence of infection. A twist-drill hole along the path of the chosen trajectory becomes an external guide for the ventricular catheter. The technique is easy, user friendly, and results in an unencumbered sterile field and reliable cannulation of small ventricles. A simple stereotactic technique for Ommaya reservoir insertion has been described. It should lower the chance of infection in this group of patients, most of whom have suppressed immune systems.

Outcome of pediatric thromboembolic disease: a report from the Canadian Childhood Thrombophilia Registry

The outcome for children with deep vein thrombosis (DVT) and pulmonary embolism (PE) is unknown. An understanding of morbidity and mortality of DVT/PE is crucial to the development of rational treatment protocols. The Canadian Childhood Thrombophilia Registry has followed 405 children aged 1 mo to 18 y with DVT/PE for a mean of 2.86 y (range, 2 wk to 6 y) to assess outcome. The all-cause mortality was 65 of 405 children (16%). Mortality directly attributable to DVT/PE occurred in nine children (2.2%), all of whom had central venous line-associated thrombosis. Morbidity was substantial, with 33 children (8.1%) having recurrent thrombosis, and 50 children (12.4%) having postphlebitic syndrome. Recurrent thrombosis and postphlebitic syndrome were more common in older children, although deaths occurred equally in all age groups. The incidence of recurrent thrombosis and postphlebitic syndrome are likely underestimated because of difficulties in diagnosis, especially in younger children. The significant mortality and morbidity found in our study supports the need for international multicenter randomized clinical trials to determine optimal prophylactic and therapeutic treatment for children with DVT/PE.

Phase I trials in pediatric oncology: perceptions of pediatricians from the United Kingdom Children's Cancer Study Group and the Pediatric Oncology Group

PURPOSE

To identify areas of concern regarding the conduct of phase I trials, the perceived expectations and motivations of the parents of children entered, the expectations of toxicity and benefit, and the ethical concerns of pediatric hematologists and oncologists in the United Kingdom and North America.

METHODS

A survey instrument consisting of 19 open- and closed-ended questions was sent to United Kingdom Children's Cancer Study Group (UKCCSG)- and Pediatric Oncology Group (POG)-affiliated pediatricians.

RESULTS

Fifty-three UKCCSG- and 78 POG-affiliated pediatricians responded. Thirty-two UKCCSG and 51 POG respondents had previously entered at least one child into a phase I study. Overall, respondents believed that parents entered their children for medical benefit, altruism, and hope of cure. Although many respondents believed that children could benefit from medical improvement, feelings of altruism, and maintenance of hope, the chance of cure or complete remission was thought to be small. Similarly, parents were thought to potentially benefit through altruism and maintenance of hope. Whereas 83% of UKCCSG respondents indicated that phase I trials were associated with ethical difficulties, this was a concern for 48% of POG respondents. The main ethical concerns of respondents were risk of toxicity, consent of the child, unrealistic hope, and coercion.

CONCLUSION

The respondents in this survey expressed mainly ethical concerns regarding the conduct of phase I trials and had realistic expectations of the potential for toxicity and benefit for those children who participate in these studies.

Brain tumor surgery with the Toronto open magnetic resonance imaging system: preliminary results for 36 patients and analysis of advantages, disadvantages, and future prospects

OBJECTIVE

Frameless navigation systems represent a huge step forward in the surgical treatment of intracranial pathological conditions but lack the ability to provide real-time imaging feedback for assessment of postoperative results, such as catheter positions and the extent of tumor resections. An open magnetic resonance imaging system for intracranial surgery was developed in Toronto, by a multidisciplinary team, to provide real-time intraoperative imaging.

METHODS

The preliminary experience with a 0.2-T, vertical-gap, magnetic resonance imaging system for intraoperative imaging, which was developed at the University of Toronto for the surgical treatment of patients with intracranial lesions, is described. The system is known as the image-guided minimally invasive therapy unit.

RESULTS

Between February 1998 and March 1999, 36 procedures were performed, including 21 tumor resections, 12 biopsies, 1 transsphenoidal endoscopic resection, and 2 catheter placements for Ommaya reservoirs. Three complications were observed. All biopsies were successful, and the surgical goals were achieved for all resections. Problems included restricted access resulting from the confines of the magnet and the imaging coil design, difficulties in working in an operating room that is less spacious and familiar, inconsistent image quality, and a lack of nonmagnetic tools that are as effective as standard neurosurgical tools. Advantages included real-time imaging to facilitate surgical planning, to confirm entry into lesions, and to assess the extent of resection and intraoperative and immediate postoperative imaging to confirm the extent of resections, catheter placement, and the absence of postoperative complications.

CONCLUSION

Intraoperative magnetic resonance imaging has great potential as an aid for intracranial surgery, but a number of logistic problems require resolution.

Addressing language barriers to health care, a survey of medical services in Switzerland

Two descriptive, quantitative cross-sectional surveys including all services of internal medicine and psychiatric services examined how Swiss medical services address the problem of language barriers in health care and how they respond to the high number of allophone patients. Of all the medical services (MS), 244 responded to the questionnaire (Internal medicine: 166; Psychiatry: 78; overall response rate 86.6%). Half of them (51%) estimated the proportion of allophone to the total number of patients at 1-5%. Only 4% of the MS collected statistics on the number of allophone patients (2 internal medicine, 8 psychiatric services). A third of the MS perceive communication with allophone patients as significantly difficult. Only 14% often use qualified interpreters, while 79% often use relatives, 75% often health staff, 43% often employees. Qualified interpreters are less frequently used in internal medicine than in psychiatry. There is an expressed need for qualified interpreters speaking Albanian, Bosnian/Serbo-croat, Tamil and Kurdish. Only 11% of the studied MS have a budget for interpreters, and 17% have access on an interpreter service. 48% express the need to have access to interpreter services. There is a need to raise the awareness of health professionals on the advantages of having access to trained interpreters and on the limits of using relatives as translators. This calls for coordination at national level, policy development and training, in order to ensure adequate communication and quality care for migrants.

Vector subtraction implemented neurally: a neurocomputational model of some sequential cognitive and conscious processes

Although great progress in neuroanatomy and physiology has occurred lately, we still cannot go directly to those levels to discover the neural mechanisms of higher cognition and consciousness. But we can use neurocomputational methods based on these details to push this project forward. Here we describe vector subtraction as an operation that computes sequential paths through high-dimensional vector spaces. Vector-space interpretations of network activity patterns are a fruitful resource in recent computational neuroscience. Vector subtraction also appears to be implemented neurally in primate frontal eye field activity, which computes dimensions of saccadic eye movements. We use this apparent neural implementation as a model and construct from it a general neurocomputational account of an important type of sequential cognitive and conscious process. We defend the biological plausibility of all components of the general model and show that it yields testable anatomical and physiological predictions. We close by suggesting some interesting consequences for consciousness if our model characterizes correctly the neural mechanisms producing a common type of episode in our conscious streams.

A phase 1-2 clinical trial of gene therapy for recurrent glioblastoma multiforme by tumor transduction with the herpes simplex thymidine kinase gene followed by ganciclovir. GLI328 European-Canadian Study Group

This study has investigated the effects of herpes simplex thymidine kinase gene (HSV-tk) transfer followed by ganciclovir treatment as adjuvant gene therapy to surgical resection in patients with recurrent glioblastoma multiforme (GBM). The study was open and single-arm, and aimed at assessing the feasibility and safety of the technique and indications of antitumor activity. In 48 patients a suspension of retroviral vector-producing cells (VPCs) was administered by intracerebral injection immediately after tumor resection. Intravenous ganciclovir was infused daily 14 to 27 days after surgery. Patients were monitored for adverse events and for life by regular biosafety assaying. Tumor changes were monitored by magnetic resonance imaging (MRI). Reflux during injection was a frequent occurrence but serious adverse events during the treatment period (days 1-27) were few and of a nature not unexpected in this population. One patient experienced transient neurological disorders associated with postganciclovir MRI enhancement. There was no evidence of replication-competent retrovirus in peripheral blood leukocytes or in tissue samples of reresection or autopsy. Vector DNA was shown in the leukocytes of some patients but not in autopsy gonadal samples. The median survival time was 8.6 months, and the 12-month survival rate was 13 of 48 (27%). On MRI studies, tumor recurrence was absent in seven patients for at least 6 months and for at least 12 months in two patients, one of whom remains recurrence free at more than 24 months. Treatment-characteristic images of injection tracks and intracavity hemoglobin were apparent. In conclusion, the gene therapy is feasible and appears to be satisfactorily safe as an adjuvant to the surgical resection of recurrent GBM, but any benefit appears to be marginal. Investigation of the precise effectiveness of this gene therapy requires prospective, controlled studies.

A Phase I trial of bryostatin-1 in children with refractory solid tumors: a Pediatric Oncology Group study

Bryostatin-1, a macrocyclic lactone, appears to elicit a wide range of biological responses including modulation of protein kinase C (PKC). PKC, one of the major elements in the signal transduction pathway, is involved in the regulation of cell growth, differentiation, gene expression, and tumor promotion. Because of the potential for a unique mechanism of interaction with tumorgenesis, a Phase I trial of bryostatin-1 was performed in children with solid tumors to: (a) establish the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD); (b) establish the pharmacokinetic profile in children; and (c) document any evidence of antitumor activity. A 1-h infusion of bryostatin-1 in a PET formulation (60% polyethylene glycol 400, 30% ethanol, and 10% Tween 80) was administered weekly for 3 weeks to 22 children (age range, 2-21 years) with malignant solid tumors refractory to conventional therapy. Doses ranged from 20 to 57 microg/m2/ dose. Pharmacokinetics were performed in at least three patients per dose level. The first course was used to determine the DLT and MTD. Twenty-two patients on five dose levels were evaluable for toxicities. At the 57 microg/m2/dose level dose-limiting myalgia (grade 3) was observed in three patients; two of those patients also experienced photophobia or eye pain, and one experienced headache. Symptoms occurred in all patients within 24-72 h after the second dose of bryostatin-1 with resolution within 1 week of onset. Other observed toxicities (grades 1 and 2) included elevation in liver transaminases, thrombocytopenia, fever, and flu-like symptoms. The bryostatin-1 infusion was typically well tolerated. Although stable disease was noted in several patients, no complete or partial responses were observed. The recommended Phase II dose of bryostatin-1 administered as a 1-h infusion weekly for 3 of every 4 weeks to children with solid tumors is 44 microg/m2/dose. Myalgia, photophobia, or eye pain, as well as headache, were found to be dose limiting.

Axonal atrophy: the retraction reaction

Recent studies indicate that morphological alterations of axon branches that are removed during normal development are similar to those that occur following ablation of postsynaptic cells in adult animals. In both situations, axons retract (rather than degenerate), the calibers of withdrawing axon branches are markedly reduced, and spherical swellings near (or at) the axon terminations appear. The similarity between naturally occurring and target-deprived axon withdrawal suggests that both developing and adult axons withdraw from target cells that no longer provide support.