Endovascular treatment of a grade IV transverse sinus dural arteriovenous fistula by sinus recanalization, angioplasty, and stent placement: technical case report

OBJECTIVE AND IMPORTANCE

The frequent association of dural arteriovenous fistulae (DAVFs) and dural sinus thrombosis may render the treatment of these complex lesions difficult. We report a case of DAVF eradicated by recanalization of the chronically thrombosed transverse sinus (TS) and sigmoid sinus followed by balloon angioplasty and stent deployment at the site of the fistula.

CLINICAL PRESENTATION

A 52-year-old man presented with a Type IV DAVF of the left TS with widespread white matter changes secondary to venous hypertension. Arterial feeders arose from the left internal carotid, external carotid, and vertebral arteries. The distal segment of the left TS, the left sigmoid sinus, and the proximal segment of the right TS were occluded. Reverse flow was observed in the deep venous system and in the superior sagittal sinus.

INTERVENTION

Endovascular access was gained through the left internal jugular vein. Mechanical recanalization of the thrombosed left TS and sigmoid sinus was followed by balloon angioplasty and placement of six overlapping stents extending from the TS to the proximal internal jugular vein. Angiograms performed after surgery showed resaturation of antegrade venous drainage as well as complete eradication of the fistulous connections. The patient was discharged with an improving clinical

CONCLUSION

Recanalization of a chronically occluded dural venous sinus through a jugular approach is feasible. In addition to eradicating cerebral venous hypertension by reestablishing antegrade venous drainage, balloon angioplasty and stent deployment at the DAVF site produced complete closure of the fistula. This may prove to be a new therapeutic strategy for management of DAVF.

The effect of contrast material on transcranial Doppler evaluation of normal middle cerebral artery peak systolic velocity

BACKGROUND AND PURPOSE

Several recent studies have shown that sonographic contrast agents may affect transcranial Doppler evaluation of the arterial peak systolic velocity (PSV). Some investigators reported an increase in PSV, and others reported no change in PSV compared with baseline values. This study was conducted to determine the effect of sonographic contrast agent on PSV measured in normal middle cerebral arteries.

METHODS

Continuous spectral Doppler sonography was performed on the right middle cerebral artery of 20 participants with angiographically proven normal intracranial vasculature. Videotaping was performed in each case from the initiation of the administration of contrast medium until the effect of the contrast agent on the PSV subsided. The PSV values were normalized for each participant, were pooled, and were plotted as a function of time.

RESULTS

PSV increased in all participants after the administration of contrast material; the mean maximum increase was 24+/-7.4% (mean +/- standard deviation) (range, 15-36%). The mean duration of PSV increase was 320+/-97 s (range, 165-465 s).

CONCLUSION

The middle cerebral artery PSV increased substantially after the administration of contrast material. This effect needs to be considered if velocity thresholds developed for disease detection without the use of contrast materials are used when contrast agents are administered.

A longitudinal study of psychological adjustment to familial genetic risk assessment for ovarian cancer

OBJECTIVES

To evaluate the psychological adjustment of women during initial genetic ovarian cancer risk assessment and at clinic follow-up, 6-12 months later.

METHODS

Sixty-five subjects were assessed with the Centre for Epidemiological Studies Depression Scale (CESD), Spielberger's State Anxiety Inventory, and an 18-item, investigator-designed questionnaire yielding self-report on screening responses, worry about increased risk, identification of cancer-related deaths in relatives, worry about future cancer risks of daughters, alteration of future plans as a result of ovarian cancer risk, etc.

RESULTS

Thirty-three percent of subjects had CESD scores above the established cutoff for depression at baseline and 38% had scores above cutoff at follow-up. Sixteen percent of subjects had state scores on the State-Trait Anxiety Inventory higher than 1 standard deviation above average (norm) at baseline, while only 6% had scores higher than 1 SD above average at follow-up.

CONCLUSION

To identify factors associated with self-reported depression at follow-up, a series of demographic and self-reported variables (e.g., presence of identified problems in family, impact of genetic risk information, concern for daughter in the future) were entered in a multiple regression analysis with the CESD follow-up score as the dependent variable. Only one predictor accounted for a significant amount of variance in depression scores. Concern for daughter's risk in the future was associated with higher depression scores at follow-up (R = 0.33, P<0.02, R(2) = 11%).

Sequential training in separate paradigms impairs second task consolidation and learning-associated modulations of hippocampal NCAM polysialylation

As transient and time-dependent modulations of neural cell adhesion molecule polysialylation (NCAM PSA) are associated with morphofunctional change and required for the consolidation of spatial and nonspatial forms of learning, we determined the demands imposed on this system by sequential training in the Morris water maze followed by the passive avoidance paradigm. Animals trained in this manner had recall of the water maze but not the passive avoidance response as judged by their escape and avoidance latencies, respectively. Activation of NCAM PSA on dentate neurons at the 12-h post-training time suggested information processing; however, this was significantly less than that predicted for coincident acquisition of both tasks. When sequential training was separated by an interparadigm period of 2 h, an enduring NCAM PSA activation was observed which was indistinguishable from the sum of the expected activations for each individual task. These observations suggest that the NCAM PSA response may become saturated when alternate tasks are presented without an intervening period.

Radiotherapy for the treatment of metastatic granulosa cell tumor in the mediastinum: a case report

OBJECTIVE

We report a case of metastatic ovarian granulosa cell tumor in the mediastinum with a 2-year disease-free interval after treatment with radiotherapy and review the literature regarding the use of radiotherapy in recurrent and metastatic granulosa cell tumor.

METHODS

The patient's medical records, histological slides, and radiological films were reviewed. The pertinent references were obtained using a Medline search and cross-references.

RESULTS

A patient with Stage 1A granulosa cell tumor developed a recurrence in the retroperitoneum 10 years after initial surgery. She was treated with chemotherapy followed by surgical resection. She subsequently developed metastatic tumor in the mediastinum which responded completely to radiotherapy. She has remained disease free for 2 years since the completion of radiotherapy.

CONCLUSION

Radiotherapy is a treatment option that should be considered in localized recurrent or metastatic granulosa cell tumor that is not amenable to surgery as it can potentially control the disease for several years.

Low-level lead exposure in the early postnatal period results in persisting neuroplastic deficits associated with memory consolidation

Prospective studies in humans and experimental investigations in animals have correlated elevated perinatal blood lead levels with enduring behavioural and cognitive perturbations. Although deficits in neuroplastic events necessary for long-term memory consolidation have been observed during the postnatal period, there is little evidence that these persist into adulthood in the absence of continued lead exposure. To address this issue, we exposed Wistar rat pups to 400 mg of PbCI2/L via their dams' drinking water from postnatal day 1 to 30. At postnatal day 80, the animals were trained in a one-trial, step-through, light-dark passive avoidance paradigm. Prior postnatal lead exposure resulted in a significant decline in recall latency on posttraining day 5, an effect that was specific to the learned response as no obvious behavioural alterations were apparent in open-field studies. As recall was unaffected in the immediate 48-h posttraining period, this suggested an enduring impairment in events associated with long-term memory storage. To investigate this further, we determined the influence of prior lead exposure on the transient modulations of hippocampal neural cell adhesion molecule polysialylation state that occur in the 10-12-h posttraining period, a neuroplastic event associated with memory consolidation. Direct quantification of polysialylated dentate neurons revealed prior lead exposure to have no effect on basal number but to significantly delay and blunt the transient increase observed in control animals at the 12-h posttraining time. These findings confirm that lead exposure in the postnatal period results in enduring neuroplastic deficits most likely associated with reordering of connections in pathways subservient to memory consolidation.

In vitro models of intracranial arteriovenous fistulas for the evaluation of new endovascular treatment materials

BACKGROUND AND PURPOSE

The purpose of this study was to create and test an in vitro model of intracranial arteriovenous fistulas (AVFs) that simulates the geometry of human vasculature and allows realistic testing of devices used in endovascular therapy.

METHODS

The models were derived from corrosion casts of the main cervicocranial arteries and veins obtained from two nonfixed human specimens. Wax copies of the casts were produced and combined to create complex models simulating various types of intracranial AVFs. Wax assemblies were embedded with liquid silicone solidified into transparent blocks containing, after wax evacuation, hollow reproductions of the original vascular trees. The models were connected to a pulsatile pump and their compatibility with various imaging techniques and endovascular treatment materials was evaluated.

RESULTS

The models were compatible with digital subtraction angiography, CT, MR imaging, and transcranial Doppler sonography. They provided a realistic endovascular environment for the simulation of interventional neuroradiologic procedures.

CONCLUSION

Anatomically accurate and reproducible in vitro models of intracranial AVFs provide a valuable method for evaluating new endovascular treatment materials and for teaching purposes.

Polysialylated neural cell adhesion molecule expression in the dentate gyrus of the human hippocampal formation from infancy to old age

Modulation of neural cell adhesion molecule polysialylation (NCAM PSA) state has been proposed to underlie morphofunctional change associated with consolidation of memory in the rodent, and its age-dependent decline to be related to impaired cognitive function. To establish whether this may be a human correlate of cognitive decline, we determined the age-dependent expression of PSA in the human hippocampal dentate gyrus using postmortem tissue derived from individuals who exhibited no obvious neuropathology. As in the rodent, PSA immunoreactivity in the 5-month human infant was associated mainly with a population of granule-like cells and their mossy fibre axons. Cell numbers were maximal during the first 3 years of life but declined by an order of magnitude between the second and third decades and remained relatively constant thereafter and was restricted to the granule cell layer/hilar border. In contrast to the rodent, diffuse immunostaining was observed in the inner molecular layer; however, as development advanced, this became relocated to the outer molecular layer from 2 years of age onwards. In addition, numerous polysialylated hilar neurons became evident at 2-3 years of age and remained constant until the eighth decade of life. These findings suggest NCAM polysialylation to play a crucial developmental role within a period concluding with adolescence, and that an attenuated NCAM PSA-mediated neuroplasticity continues throughout the human lifespan. The importance of the developmental phase of NCAM PSA expression in the emergence of schizophrenia is discussed.

The acute outcome of tibioperoneal vessel angioplasty in 417 cases with claudication and critical limb ischemia

A non-randomized, consecutive series of 417 first procedure tibioperoneal vessel angioplasty (TPVA) cases were analyzed to determine if angioplasty were an alternative revascularization technique for critical limb ischemia (CLI) and claudicants patients. TPVA was performed on 312 patients (70% male; age 66 +/- 10 years) with success attained in 406/417 cases (96%) of 605/657 lesions (92%): [461/469 stenoses (98%) and 144/188 occlusions (77%) *(P < 0.05)]. Claudication and CLI patients had similar rates of success. In claudication patients clinical success was 130/133 (98%); lesion success was 197/208 (92%); stenosis was 148/151 (98%); and occlusion was 49/57 (86%). In CLI patients clinical success was 270/284 (95%); lesion success was 408/449 (91%); stenosis was 313/318 (98%); and occlusion was 95/131 (73%). We conclude that TPVA is an effective revascularization technique for obstructed tibioperoneal vessels, with excellent success in stenotic (98%) and reasonable results in occluded vessels (77%). These data demonstrate TPVA effectiveness in CLI patients and in carefully selected claudicants with appropriate indications (severe, lifestyle limiting claudication) and readily amenable anatomy, and TPVA for CLI patients appears to be an effective revascularization technique.

Nefiracetam prevents propofol-induced anterograde and retrograde amnesia in the rodent without compromising quality of anesthesia

BACKGROUND

Propofol is a short-acting intravenous anesthetic agent. However, cognitive function remains depressed for several hours thereafter. We have evaluated the ability of nefiracetam, a novel cognition-enhancing agent, to alleviate propofol-induced amnesia in a rodent model of learning.

METHODS

Rats were trained in a one-trial, step-through, light-dark passive avoidance paradigm. Propofol (10 and 75 mg/kg) was administered by the intraperitoneal route at 15 min before training and separately at increasing times in the immediate 0-6 h post-training period (100 and 150 mg/kg). Nefiracetam, 9 mg/kg, was administered by the intraperitoneal route 1 h before training. Animals were tested for recall at the 12 h post-training time, and after their killing, immunocytochemistry was used to determine the increase in hippocampal neuronal polysialylation, an event associated with memory consolidation. Induction and duration of anesthesia induced by propofol was determined using tail pinch and pedal withdrawal reflexes.

RESULTS

Propofol-induced anterograde amnesia occurred in a dose-dependent manner. Induction of retrograde amnesia required a higher dose of propofol, which anesthetized the animals and was effective only in the immediate 3-h post-training period. In the absence of any evident effect on the onset or duration of anesthesia, nefiracetam prevented both forms of propofol-induced amnesia and preserved the learning-associated changes of neuronal polysialylation state.

CONCLUSIONS

The ability of nefiracetam to prevent propofol-induced anterograde and retrograde amnesia is proposed to be indirect and to result from modulation of gene transcription in a manner that initiates a cascade of events involving protein synthesis leading to synaptic growth associated with the formation of the long-term memory trace.

Kv1.1 channel antisense attenuates learning and modulation of dentate polysialylated NCAM

The distribution and modulation of neural cell adhesion molecule polysialylation state (NCAM PSA) and the consequence of antisense inactivation of the Kv1.1 potassium channel was investigated following avoidance learning in mice. PSA immunoreactivity was most notable on cells at the inner denate border and in cortical layer II. Task acquisition resulted in a significant 30% transient increase in the frequency of dentate polysialylated neurons at the 12 h post-training time. In contrast, animals pretreated with the Kv1.1 antisense oligonucleotide exhibited both attenuated recall avoidance latencies and polysialylated cell frequency. As Kv1.1 is enriched on the dendrites of these granule-like cells, the attenuated polysialylation response is considered secondary to NCAM-mediated events during their transient synapse production in the 6-8 h post-training period.

Contributions of cell adhesion molecules to altered synaptic weightings during memory consolidation

The fundamental concept that synapse growth and change are associated with learning is considered a "replay" of early neurodevelopmental principles that instruct neural connectivity pattern. Common mechanisms suggested to link the process of memory formation through synaptic elaboration are exemplified by the activity of cell adhesion molecules following learning and that center on waves of glycoprotein synthesis occurring in the 6- to 8-h and 10- to 12-h posttraining periods of consolidation. These are associated with spatially clustered granule cells in the adult rat hippocampus that show a transient time-dependent increase in ribosome production and greater microtubular complexity and dendritic spine number 6 to 8 h following training. The elimination and/or selection of the synapses to be retained in the memory trace is proposed to be dependent on cell adhesion molecule glycosylation events in the 10- to 12-h posttraining period. The existence of similar cell adhesion molecule glycosylation mechanisms within a corticohippocampal pathway is used to contribute to a model of memory in which sensory representations are eventually consolidated through relative change in synaptic weightings.

Spinal cord infection: myelitis and abscess formation

PURPOSE

Our purpose was to describe the MR findings and evolution of spinal cord abscess and to define those MR features that allow differentiation of cord infection from other intramedullary abnormalities.

METHODS

We retrospectively reviewed the MR studies of all patients in whom intramedullary spinal cord abscess was proved either by blood or cerebrospinal fluid culture or by serologic examination at our institution between January 1988 and January 1996. The study group included four adults and two children, 7 to 74 years old (mean age, 38 years).

RESULTS

Initial MR studies showed intramedullary high signal on T2-weighted sequences with poorly defined marginal enhancement on T1-weighted images. On follow-up contrast-enhanced T1-weighted studies, the lesions had well-defined enhancing margins with central low signal intensity. After the initiation of therapy, T2 signal abnormalities decreased markedly and contrast-enhanced studies showed ring enhancement. These T1 findings resolved with treatment over serial studies in four patients. The organisms identified were Streptococcus milleria, S pyogenes, atypical mycobacteria, Mycobacterium tuberculosis, and Schistosoma mansoni (both children).

CONCLUSION

A characteristic sequence of imaging findings aids in the differentiation of cord infection from other intramedullary lesions.

Use of intravenous contrast material in transcranial sonography

RATIONALE AND OBJECTIVES

The appearance of the intracranial vasculature was compared on power and color Doppler ultrasound (US) scans obtained with and without a microbubble contrast agent.

MATERIALS AND METHODS

Nine patients (three men, six women) aged 42-70 years (mean age, 53 years) participated in the study. Seven patients underwent both color Doppler US and power Doppler US before and after intravenous administration of contrast agent, and two underwent only color Doppler US. All patients had previously undergone cerebral angiography.

RESULTS

Before contrast material was administered, power Doppler US was more sensitive than color Doppler US in the detection of intracranial vessels (P < .05); neither technique depicted the entire circle of Willis in eight of nine patients. Postcontrast power Doppler US depicted more vascular segments than postcontrast color Doppler US (P < .01) or precontrast power Doppler US (P < .01). Use of intravenous contrast material enabled the entire circle of Willis to be evaluated from a single temporal bone acoustic window with both power Doppler US and color Doppler US in all patients. Contrast-enhanced power Doppler US depicted vessels not shown by enhanced color Doppler US.

CONCLUSION

Contrast-enhanced power Doppler US depicted more vessels, better demonstrated specific vascular segments, and provided better vascular definition of the intracranial vasculature than contrast-enhanced color Doppler US or unenhanced power Doppler US.

Etidronate therapy decreases the sensitivity of bone scanning with methylene diphosphonate labelled with technetium-99m

OBJECTIVE

To define the nature, incidence and consequence of a possible interaction between etidronate (for the treatment of hypercalcemia) and methylene diphosphonate labelled with technetium-99m (99mTc-MDP) (for bone scanning).

MATERIALS AND METHODS

The authors reviewed hospital pharmacy records for a period of 2 years and identified 18 patients who had received etidronate. Of this group, 6 patients (4 men and 2 women, ranging in age from 56 to 76 years) had undergone bone scanning with 99mTc-MDP while receiving etidronate. Five of the patients had hypercalcemia associated with metastatic disease, and the sixth had hyperparathyroidism.

RESULTS

All bone scans demonstrated poor uptake of tracer by bone accompanied by high soft-tissue background. There was loss of bone definition below the mid-thigh, and in 5 of the 6 patients there was indistinguishable rib uptake. In 1 of the patients, there was absence of uptake in 2 previously defined metastatic lesions.

CONCLUSION

Recent oral or intravenous administration of etidronate is a contraindication to bone scintigraphy, as it markedly decreases sensitivity for bone disease. Bone scintigraphy should be timed so that it is performed before etidronate treatment or, if that is not possible, more than 2 to 4 weeks after the therapy has been completed.

Spatial learning activates neural cell adhesion molecule polysialylation in a corticohippocampal pathway within the medial temporal lobe

Transient and time-dependent modulations of neural cell adhesion molecule (NCAM) polysialylation in the dentate gyrus of the rodent hippocampus are a feature of spatial and nonspatial forms of learning. In the hippocampal formation, polysialic acid immunoreactivity was localized to granule-like cells and their mossy fibre axons. We now demonstrate the latter to extend to the CA3 region where apparent recurrent and Schaffer collaterals were labelled. The axons of the CA1 pyramidal cell layer were immunopositive, as was the subiculum that they innervate. Layers I and III of the entorhinal cortex stained intensely for polysialic acid; however, these were not visible in the more lateral aspect of this region and were replaced by a single band of immunopositive neurons that extended to include the perirhinal and piriform cortices. After Morris water maze training, the number of polysialylated neurons within the entorhinal cortex exhibited a two- to threefold increase at the 10-12-h posttraining time with respect to that observed immediately after training. This increase was task specific, as no change was observed in freely swimming animals or those required to locate a visible platform. These results suggest the presence of a corticohippocampal pathway involved in the eventual consolidation of memory.

Psychological impact of screening for familial ovarian cancer: reactions to initial assessment

OBJECTIVES

To assess the psychological impact on women attending a familial ovarian cancer screening clinic.

STUDY METHODS

157 women referred for screening completed an investigator designed questionnaire, the Spielberger State Trait Anxiety Scale and the Centre for Epidemiological Studies Depression Scale prior to the screening interview and an eight-item questionnaire post-assessment.

RESULTS

95.4% saw the screening as valuable. Thirty-one point four percent of all patients scored about the cutoff point for depression. Sixteen percent exhibited high levels of anxiety. Fifty-six point four percent of patients accurately perceived their risk. Twenty-one point five percent of those who accurately perceived themselves as being at high risk had high anxiety and 40.6% reported significant depressive symptoms. Of the 26.5% of patients who overestimated their risks, 40.0% reported significant depressive symptoms and 22.6% were anxious. Of the 17.1% who minimized their risk, none were anxious (0.0%), and only 15.8% were depressed.

CONCLUSION

Attendees at a familial ovarian cancer screening clinic may have high levels of depression and anxiety.

Power Doppler: it's a good thing

Power Doppler is a new method of ultrasound flow imaging the utility of which is currently under investigation. This technique creates a flow map based on the integrated power of the Doppler spectrum, rather than mean Doppler frequency. Power Doppler imaging is inherently more sensitive in terms of flow detection than standard color Doppler imaging; therefore, power Doppler can display flow for situations in which color Doppler is ineffective and can even display tissue perfusion in highly vascular organs such as the kidneys. Furthermore, power Doppler is not effected by aliasing, nor is it effected by blooming in the same way as color Doppler, which has deleterious effects on color Doppler flow images. The control of blooming with power Doppler may be of great importance in the clinical application of echo-enhancing agents. This review article discusses in detail the technological advantages and disadvantages of power Doppler flow imaging. In addition, it provides a synopsis of the preliminary research studies that have been conducted to date with respect to the clinical applications of power Doppler.

Influence of nefiracetam on NGF-induced neuritogenesis and neural cell adhesion molecule polysialic acid expression: in vivo and in vitro comparisons

Previously, the ability of co-administered nefiracetam to reverse scopolamine-induced learning deficits has been attributed to the preservation of a transient increase in neural cell adhesion molecule (NCAM) polysialylation state during a late phase of memory consolidation (Doyle et al., J. Neurosci. Res., 31 (1992) 513-523). Using the PC-12 pheochromocytoma cell model, we now demonstrate nefiracetam pre-exposure to significantly enhance nerve growth factor-induced neuritogenesis and NCAM polysialylation, but not prevalence, in a dose-dependent manner with maximal effects being observed at the lowest dose (0.1 microM) examined. As the memory-associated increase in NCAM polysialylation in vivo is associated with a defined group of neurons at the dentate hilar/granule cell layer border (Regan and Fox, Neurochem. Res., 20 (1995) 521-526), the effect of chronic nefiracetam exposure in vivo was evaluated. Once-daily, intraperitoneal administration of either 3 or 9 mg/kg nefiracetam to adult male Wistar rats for 40 days significantly increased the number of hippocampal dentate polysialylated neurons only at the highest dose evaluated, suggesting it to prevent their age-dependent decline. These results are consistent with nefiracetam facilitating early induction events of long-term memory consolidation processes involving NCAM polysialylation state.

Adult claustrophobia, anxiety and sedation in MRI

The purpose of this study was to identify the proportion of adult patients at our institution who require sedation to tolerate MR imaging. We also wished to identify whether the type of study and patient age or sex was associated with a variation in the use of sedation. A total of 939 patients, 18 years of age or older, underwent MR imaging at a large university hospital during a randomly selected 7-week period. Age, sex, type of study, number of prior MRI's, and use of sedation were identified in this group. Patients requiring sedation were compared by these criteria to all non-sedated members over 18 years of age in the cohort who acted as a control. Of the 939 patients 134 (14.3%) required oral sedation, i.v. sedation, or general anesthesia to tolerate MRI. This group was 35.8% male, 64.1% female (control group 48.1% male, 51.9% female). Of those requiring sedation, 89 patients (66.4%) were having brain MRI (male n = 29 or 32.6%, female n = 60 or 67.4%). In the control group 461 patients (57.3%) were having brain MRI (male n = 209 or 45.3%, female n = 252 or 54.6%). The mean age of the sedated group was 60.75 (range 19-91). The non-sedated group had a mean age of 67.3 (range 28-93). The sedated group had undergone a mean of 1.56 prior MR studies (range 0-16); the control group had a mean of 0.9 prior studies (range 0-7). Sedation was more commonly utilized in women than men, in patients having brain MRI, and in patients who had undergone prior MRI procedures. The identification of a population having the greatest need for sedation may aid in the development and selection of methods of stress reduction which will result in greater patient comfort, reduction in motion artifact, and fewer prematurely terminated studies.

Renal transplant evaluation with power Doppler sonography

This study was performed to determine if the marked variation we had previously noted in the power Doppler sonographic appearance of renal transplants correlated with disease, 22 renal transplants were scanned with power Doppler at 5 MHz, with biopsies being taken within 1 h in 17 kidneys and within 48 h in four other kidneys. Biopsy was not performed in one kidney with distal ureteral obstruction. Biopsy results were complex with many coexistent abnormalities; classification was based upon the predominant abnormality. Cortical vascularity was subjectively evaluated as normal, decreased or markedly decreased, and graded as 0, 1 or 2, respectively, and was compared with biopsy results, serum creatinine levels and resistive index. Cortical vascularity gradings were: 0 (12 cases); 1 (7 cases); and 2 (3 cases). The large number of disease categories (cellular rejection, 11 cases; vascular rejection, 5 cases; IgA nephropathy, 1 case; cyclosporin toxicity, 3 cases; obstruction, 1 case; and lupus nephropathy, 1 case) in relation to the number of vascular grades and number of kidneys precluded statistical analysis of cortical vascularity for rejection. However, vascularity did not appear to correlate with rejection, the three severest cases of vascular rejection having normal (grade 0) vascularity. There was no statistically significant correlation of vascular grade with creatinine levels or resistive index. In conclusion, subjective analysis of the power Doppler sonographic appearance of renal transplants does not appear to aid in their evaluation.

Radiographic appearance of intrathoracic complications of pregnancy

The authors reviewed all chest radiographs obtained for pregnant women at a university hospital over a 15-year period to determine the intrathoracic complications of pregnancy and diseases occurring during pregnancy. The characteristic physiologic changes seen on chest radiographs during normal pregnancy are reviewed. Examples of intrathoracic diseases that may occur in pregnant patients include pulmonary embolism, amniotic fluid embolism, beriberi, aspiration pneumonia, community-acquired pneumonia, viral pneumonia, asthma, systemic disease, trophoblastic disease and peripartum pulmonary edema. The authors discuss the radiation biology implications of performing chest radiography during pregnancy and conclude that the benefit that the fetus receives from diagnosis and treatment of the mother's disease may be greater than the risk of radiation exposure.

Adverse reactions to gadolinium contrast media: a review of 36 cases

OBJECTIVE

We investigated the frequency, manifestations, and severity of reactions to gadolinium contrast media in patients who underwent MR imaging at a single institution.

MATERIALS AND METHODS

We reviewed the quality assurance records of 21,000 patients to whom gadolinium contrast media were administered at our institution between January 1990 and October 1994. Of these patients, 36 had adverse reactions. All 36 patients were evaluated by a radiologist at the time of the adverse reaction, and a written report of the findings was completed immediately.

RESULTS

We classified adverse reactions into four groups: mild nonallergic reactions (15 patients with nausea or vomiting), mild reactions resembling allergy (12 patients with hives, diffuse erythema, or skin irritation), moderate reactions resembling allergy (seven patients with respiratory symptoms), and life-threatening reactions resembling allergy (two patients with severe chest tightness, respiratory distress, and periorbital edema). Eleven of these 36 patients who had adverse reactions also had an unusual local reaction of skin discomfort in the extremity through which gadolinium was injected. Four of the 36 patients with adverse reactions had histories of adverse reactions to iodinated contrast media. All four of these patients and one of the remaining 32 patients with adverse reactions required treatment. No patients with adverse reactions died.

CONCLUSION

Although gadolinium contrast media are safe, we found that patients had adverse reactions at a frequency greater than we expected. Severe anaphylactoid reactions occurred in two patients (0.01%). This rate exceeds the rate of 0.0003% reported in the literature. The indexes of suspicion for the occurrence of reactions to gadolinium, and both the documentation and the management of adverse reactions, must be as rigorous for reactions associated with MR imaging contrast agents as they are for reactions associated with iodinated contrast media.

Orbital plain films as a prerequisite for MR imaging: is a known history of injury a sufficient screening criterion?

OBJECTIVE

Before undergoing MR imaging at our institution, all patients with potential occupational, recreational, or educational exposure or known accidental exposure to kinetic metal fragments have orbital radiographs to evaluate for the continued presence of intraorbital metallic foreign bodies. The purpose of this study was to evaluate the potential safety of a protocol that would call for obtaining plain films of the orbit before MR imaging only for patients with a definite history of a known metallic foreign body in the eye or orbit.

MATERIALS AND METHODS

A total of 2626 patients underwent plain radiography of the orbit to exclude metallic foreign bodies before MR imaging between March 1991 and January 1995. These patients were identified by a billing code number. Reports from these studies, all interpreted by board-certified radiologists, were reviewed. When a metallic foreign body was detected, we reviewed the patient's response during the initial interview when asked about a history of orbital injury or surgery.

RESULTS

Of 2626 patients undergoing orbital radiographic studies, 17 (0.65%) had radiographic evidence of intraorbital metallic foreign bodies. Sixteen of these patients gave a history of known injury or had knowledge of probable orbital metallic fragments. The remaining patient, a welder screened because of occupational history, had a 3 x 1 mm metallic foreign body in his left orbit without a history of injury.

CONCLUSION

Screening plain films of the orbit are necessary when a patient has a history of a known intraocular or periorbital foreign body or when a patient has a history of occupational exposure to potential metallic ocular injury, as do welders, grinders, and metalworkers.

Repetitive and transient increases in hippocampal neural cell adhesion molecule polysialylation state following multitrial spatial training

Polysialylated neurons, located at the inner border of the dentate granule cell layer, have been demonstrated to exhibit time-dependent change in their frequency at 10-12 h following training in the Morris water maze, a spatial learning paradigm. Such a change was not observed in animals required to locate a visible platform or in those rendered amnesic with scopolamine. This frequency response was capable of rapid reactivation following further training stimuli in a manner that was independent of circadian influence. These learning-associated modulations in neural cell adhesion molecule (NCAM) polysialylation state did not increase in magnitude despite improved performance, suggesting their activation is required for processing information rather than contributing to previously stored, task-associated memory. An increase in NCAM polysialylation appears to be a universal learning response to both spatial and nonspatial paradigms as similar time-dependent changes occurred following training in a one-trial, step-through, passive avoidance response subsequent to water maze training.

3D gadolinium-enhanced MR angiography of the carotid arteries

PURPOSE

To compare gadolinium-enhanced magnetic resonance angiography (MRA) of the carotid bifurcation with 2D time-of-flight (TOF) MR angiography with regard to image quality and duration of examination.

MATERIALS AND METHODS

Gadolinium contrast was administered intravenously during 3D MR imaging at 1.5 Tesla in 46 patients presenting with suspected carotid occlusive disease. 2D time-of-flight MR angiography of the carotid bifurcation had been performed in each patient prior to gadolinium-enhanced MR angiography.

RESULTS

Gadolinium MRA eliminated slice misregistration and in-plane saturation artifacts that occasionally degrades 2D TOF MR angiography. Gadolinium MRA required less than 4 min to image from the aortic arch to the skull base compared to 11 min for 2D TOF with comparable signal-to-noise ratio (SNR). Postprocessing was required to eliminate overlapping venous enhancement. Both techniques had susceptibility related artifactual loss of signal at the skull base and both demonstrated a linear artifact paralleling the long axis of arteries.

CONCLUSION

Gadolinium-enhanced MR angiography is a promising technique for the evaluation of patients with carotid occlusive disease because it rapidly images the carotid arteries from the aortic arch to the skull base and eliminates some of the artifacts that degrade 2D TOF MR angiography.

Memory consolidation induces a transient and time-dependent increase in the frequency of neural cell adhesion molecule polysialylated cells in the adult rat hippocampus

Animals trained in a passive avoidance task exhibit a transient time-dependent increase in hippocampal neural cell adhesion molecule (NCAM) polysialylation at 12-24 h following the initial learning trial. Using immunocytochemical techniques with a monoclonal antibody that specifically recognises NCAM-polysialic acid homopolymers, a distinct population of granule-like cells, at the border of the granule cell layer and the hilus in the dentate gyrus of the adult rat hippocampus, has been demonstrated to exhibit time-dependent change in frequency at 10-12 h following the initial learning of a one-trial, step-through, passive avoidance response. These changes were paradigm specific as they failed to occur in those animals rendered amnesic with scopolamine. These polysialylated dentate neurons are not de novo granule cell precursors as administration of 5-bromo-2'-deoxyuridine every 2 h from the point of learning to the 12-h posttraining time showed no significant difference between trained and passive animals in the small number of heterogeneously distributed, labelled cells. These findings directly identify a morphological substrate of memory, implied by previous correlative and interventive studies on NCAM function.

Influence of toxicants on neural cell adhesion molecule-mediated neuroplasticity in the developing and adult animal: persistent effects of chronic perinatal low-level lead exposure

The expression of neuroplastic neural cell adhesion molecule (NCAM) polysialylated neurons in the dentate of juvenile (postnatal day 40) and adult (postnatal day 80) rats exposed to low-level lead during the early postnatal period has been investigated. At both ages, the number of polysialylated neurons was decreased significantly in lead-exposed animals when expressed per unit area but not total dentate area. This could be attributed to an increase in the number and intercellular spacing of granule cells in the dentate of the lead-exposed animals. These effects are related to NCAM polysialylation dysfunction perturbing early hippocampal neurogenesis.

Good outcome associated with a standardized treatment protocol using selective postoperative radiation in patients with clinical stage I adenocarcinoma of the endometrium

In 1982, a treatment protocol was instituted for the management of patients with clinical stage I adenocarcinoma of the endometrium. All pertinent historical, operative, and pathologic findings were reviewed by a multidisciplinary committee and 384 patients were prospectively assigned to either high- or low-risk categories. Patients were excluded from the study if they had clinically apparent extrauterine disease, clear cell or serous histologies, or microscopic ovarian metastasis. Patients were considered high-risk if they had one or more of the following factors: grade 3 tumor differentiation, myometrial invasion > 50% of the total wall thickness, pathologic cervical involvement, or adenosquamous histology. Two-hundred twenty-seven (59%) low-risk patients were followed without further treatment after surgery, while pelvic radiation was recommended for 157 (41%) high-risk patients. The 5-year relapse-free survival rates in the low- and high-risk groups were 95 and 81%, respectively. There were no treatment-related deaths. Severe or life threatening chronic radiotherapy complications occurred in 6 (5%) patients. Multivariate Cox analysis identified the following significant prognostic factors: grade, myometrial invasion, cervix involvement, and age. This treatment protocol represents a safe and effective method of managing patients with carcinoma of the endometrium and spares the need for radiation therapy in the low-risk patient.

Carcinoma of the vagina--experience at the Princess Margaret Hospital (1974-1989)

The charts of 153 patients with vaginal carcinoma or carcinoma in situ seen at Princess Margaret Hospital between 1974 and 1989 were analyzed with respect to treatment modality, radiation dose and technique, complications, and survival. One hundred and twenty-eight patients were treated with radiation therapy, of which 10 received radiation postoperatively and 26 concomitant chemotherapy. The overall 5-year actuarial cause-specific survival was 66%. The 5-year cause-specific survivals by stage were Stage 0 (C-I-S) 100%, Stages I/II 77%, and Stages III/IV 56%. Late complications from treatment were infrequent and in only 12 patients were such complications classified as severe. Univariate analysis indicated that size and stage of tumor, histological grade, patient age, and radiation dose > 7000 cGy were significant factors in predicting survival, although in a multivariate analysis only size and stage retained significance. Fifty-one patients had a prior gynecological malignancy arising 1-37 years previously, of which 34 had cervical cancers. Radiotherapy is an effective treatment for all stages of carcinoma of the vagina and doses of at least 7000 cGy are recommended to maximize tumor control.

Separate neural pathways for the visual analysis of object shape in perception and prehension

BACKGROUND

Earlier work with neurological patients has shown that the visual perception of object size and orientation depends on visual pathways in the cerebral cortex that are separate from those mediating the use of these same object properties in the control of goal-directed grasping. We present evidence suggesting that the same dissociation between perception and action is evident in the visual processing of object shape. In other words, discrimination between objects on the basis of their shape appears to be mediated by visual mechanisms that are functionally and neurally distinct from those controlling the pre-shaping of the hand during grasping movements directed at those same objects.

RESULTS

We studied two patients with lesions in different parts of the cerebral visual pathways. One patient (RV), who had sustained bilateral lesions of the occipitoparietal cortex, was unable to use visual information to place her fingers correctly on the circumference of irregularly shaped objects when asked to pick them up, even though she had no difficulty in visually discriminating one such object from another. Conversely, a second patient (DF), who had bilateral damage in the ventrolateral occipital region, had no difficulty in placing her fingers on appropriate opposition points during grasping, even though she was unable to discriminate visually amongst such objects.

CONCLUSIONS

This double dissociation lends strong support to the idea that the visual mechanisms mediating the perception of objects are functionally and neurally distinct from those mediating the control of skilled actions directed at those objects. It also supports the recent proposal of Goodale and Milner that visual perception depends on a ventral stream of projections from the primary visual cortex to the inferotemporal cortex, whereas the visual control of skilled actions depends on a dorsal stream from the primary visual cortex to the posterior parietal cortex.

Health psychology: status and trends

This study investigated the present status and suggested trends in health psychology as reported by American Psychological Association Division 38 (Health Psychology) members. A 25-item mail-in survey was developed to obtain these data from a randomly selected sample of 300. Information includes a demographic description of the respondents, their selection of influential books, journals, and individuals, and their opinions regarding the current status and desirable future trends in the field of health psychology.

Walker-Warburg syndrome. Case report and literature review

The Walker-Warburg syndrome (WWS) is a fatal dysmorphic disorder of unknown etiology, but strongly suggests an autosomal recessive mode of inheritance. It is characterized by severe congenital oculo-cerebral malformations (lissencephaly, congenital hydrocephalus, and ocular lesions). The authors report a case of WWS that occurred in a consanguineous union, with a review of the literature. Possible pathogenesis, and disorders sharing the features of WWS are discussed. Families-at-risk for WWS should be identified for prenatal diagnosis and for genetic counselling.

CEO incentives-its not how much you pay, but how

The arrival of spring means yet another round in the national debate over executive compensation. But the critics have it wrong. The relentless attention on how much CEOs are paid diverts public attention from the real problem-how CEOs are paid. The authors present an in-depth statistical analysis of executive compensation. The study incorporates data on thousands of CEOs spanning five decades. Their surprising conclusions are at odds with the prevailing wisdom on CEO pay: Despite the headlines, top executives are not receiving record salaries and bonuses. Cash compensation has increased over the past 15 years, but CEO pay levels are just now catching up to where they were 50 years ago. Annual changes in executive compensation do not reflect changes in corporate performance. For the median CEO in the 250 largest public companies, a $1,000 change in shareholder value corresponds to a change of just 6.7 cents in salary and bonus over a two-year period. With respect to pay for performance, CEO compensation is getting worse rather than better. CEO stock ownership-the best link between shareholder wealth and executive well-being-was ten times greater in the 1930s than in the 1980s. Compensation policy is one of the most important factors in an organization's success. Not only does it shape how top executives behave but it also helps determine what kind of executives an organization attracts. That's why it's so urgent that boards of directors reform their compensation practices and adopt systems that reward outstanding performance and penalize poor performance.

Maternal mortality in British Columbia in 1971-86

We reviewed the 56 maternal deaths in British Columbia in 1971-78 and 1979-86 identified through the provincial Ministry of Health and compared the findings with data for the two preceding 8-year periods. The maternal death rate, defined as the number of deaths directly or indirectly related to pregnancy or delivery per 100,000 live births, decreased from 42 in 1955-62 to 5 in 1979-86. In the same interval the number of direct obstetric deaths decreased from 100 to 10 and the number of indirect deaths from 29 to 8. The number of deaths due to abortion decreased from 32 to 1. There was no change in the number of deaths among North American Indians. There was also no change in the number of deaths due to hypertension, most of which were avoidable; these findings have stimulated intensive teaching efforts to increase recognition and improve management of the problem. Review of maternal deaths can help identify deficiencies in the quality of care and can direct measures aimed at further reducing the maternal death rate.

Predictive value of CA 125 for ovarian carcinoma in patients presenting with pelvic masses

Between November 1984 and May 1986, 56 patients presenting with a pelvic mass to the Gynecologic Oncology Service of McMaster University and the Hamilton Regional Oncology Center underwent laparotomy for possible ovarian cancer. All patients had blood drawn for CA 125 three days before operation. Levels above 35 U/mL were considered positive; CA 125 had a positive predictive value of 60%. False positives occurred in patients with nongynecologic malignancies and with benign gynecologic conditions. On the other hand, CA 125 had a negative predictive value of 100%, suggesting that this test may be useful in identifying those patients with pelvic masses at higher risk for malignancy, who may require transfer for surgery at a tertiary care center.

Pelvic exenteration

Exenteration, or complete excision of the pelvic viscera, is an ultra-radical surgical procedure intended for curative treatment of the patient with advanced pelvic malignancy--primary or recurrent. At the time of introduction of this procedure, enthusiasm for its use was marred by the high incidence of serious surgical morbidity and mortality, which approached the five-year survival rate. With more careful physiological and psychological selection of patients, concentration of this kind of procedure in centres familiar with its use, improved urinary conduit techniques and careful attention to covering the pelvic floor with omentum and/or synthetic materials, the morbidity and mortality rate has been significantly reduced thus making exenteration a more acceptable treatment option to a wider spectrum of patients. More sophisticated haemodynamic monitoring, both intra- and postoperatively, intravenous hyperalimentation, prophylactic antibiotics and low-dose heparin are undoubtedly important adjuncts to the improvements in surgical technique and judgment. Psychosexual 'rehabilitation' in the broadest sense must be an integral part of patient care for those undergoing exenteration and in most instances necessitates involvement of the patient's partner. Exenteration has only a very limited role in palliation and all attempts should be made to avoid this procedure when cure is clearly not a possibility.

Cervical cancer screening. Who needs a Pap test? How often?

Cancer of the cervix and its preinvasive forms are ideally suited to control by means of cytologic screening programs. Ample evidence shows that widespread use of such programs markedly reduces both the incidence and mortality of clinically invasive carcinoma of the cervix. Thus, physicians should encourage female patients to participate in a cervical cytologic screening program. In addition, family practitioners and internists, when seeing female patients for nongynecologic problems, should not miss the opportunity to obtain a Pap smear whenever appropriate.

Primary invasive carcinoma of the vagina

Data are presented from 97 patients treated for invasive primary epithelial carcinoma of the vagina between 1950 and 1980. The disease is primarily one of the elderly as 63% were found to be older than 60 years of age. Eleven of the 97 patients either refused or were unable to complete treatment because of poor medical condition or advanced stage of disease. Combined external and intracavitary radiation was the most common form of treatment. The overall two-year survival rate was 47%, or 59% when corrected for deaths due to other causes. Patients with stages I and II disease had corrected survival rates of 75% and 68%, respectively. Our results indicate that stage of disease is the most significant prognostic factor. Optimal results will be obtained with early diagnosis and individualized treatment.

Delayed rupture of the left ventricle after mitral valve replacement: report of two survivors

Two patients, a man and a woman, with rupture of the left ventricular wall after mitral valve replacement are described. The postoperative course of the woman was complicated by respiratory and renal insufficiency from which she recovered; however, she developed fungal endocarditis and died. Both patients are reported as survivors of "delayed" rupture to show that such patients are occasionally salvageable, and to suggest that bypass grafting to the circumflex system distal to the site of injury will benefit immediate and long-term survival.