Practical guidelines for optimal gamma probe detection of sentinel lymph nodes in breast cancer: results of a multi-institutional study. For the University of Louisville Breast Cancer Study Group

INTRODUCTION

Multiple radioactive lymph nodes are often removed during the course of sentinel lymph node (SLN) biopsy for breast cancer when both blue dye and radioactive colloid injection are used. Some of the less radioactive lymph nodes are second echelon nodes, not true SLNs. The purpose of this analysis was to determine whether harvesting these less radioactive nodes, in addition to the "hottest" SLNs, reduces the false-negative rate.

METHODS

Patients were enrolled in this multicenter (121 surgeons) prospective, institutional review board-approved study after informed consent was obtained. Patients with clinical stage T1-2, N0, M0 invasive breast cancer were eligible. This analysis includes all patients who underwent axillary SLN biopsy with the use of an injection of both isosulfan blue dye and radioactive colloid. The protocol specified that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest node should be removed and designated SLNs. All patients underwent completion level I/II axillary dissection.

RESULTS

SLNs were identified in 672 of 758 patients (89%). Of the patients with SLNs identified, 403 patients (60%) had more than 1 SLN removed (mean, 1.96 SLN/patient) and 207 patients (31%) had nodal metastases. The use of filtered or unfiltered technetium sulfur colloid had no impact on the number of SLNs identified. Overall, 33% of histologically positive SLNs had no evidence of blue dye staining. Of those patients with multiple SLNs removed, histologically positive SLNs were found in 130 patients. In 15 of these 130 patients (11.5%), the hottest SLN was negative when a less radioactive node was positive for tumor. If only the hottest node had been removed, the false-negative rate would have been 13.0% versus 5.8% when all nodes with 10% or more of the ex vivo count of the hottest node were removed (P =.01).

CONCLUSIONS

These data support the policy that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest SLN should be harvested for optimal nodal staging.

Visual confrontation naming and hippocampal function: A neural network study using quantitative (1)H magnetic resonance spectroscopy

Prior research on the relationship between visual confrontation naming and hippocampal function has been inconclusive. The present study examined this relationship using quantitative (1)H magnetic resonance spectroscopy ((1)H-MRS) to operationalize the function of the left and right hippocampi. The 60-item Boston Naming Test (BNT) was used to measure naming. Our sample included 46 patients with medically intractable, focal mesial temporal lobe epilepsy who had been screened for all pathology other than mesial temporal sclerosis. Statistics included Pearson correlations and neural network analysis (multilayer perceptron and radial basis function). Baseline BNT performance correlated significantly with left (1)H-MRS hippocampal ratios. Thirty-six per cent of the variance in baseline BNT performance was explained by a neural network model using left and right (1)H-MRS ratios(creatine/N-acetylaspartate) as input. This was elevated to 49% when input from the right hippocampus was lesioned mathematically. In a second model, left (1)H-MRS hippocampal ratios were modelled using measures of semantic and episodic memory as input (including the BNT). Explained variance in left (1)H-MRS hippocampal ratios fell from 60.8 to 3.6% when input from BNT and another semantic memory measure was degraded mathematically. These results provide evidence that the speech-dominant hippocampus is a significant component of the overall neuroanatomical network of visual confrontation naming. Clinical and theoretical implications are explored.

Basosquamous carcinoma: analysis of prognostic factors influencing recurrence

BACKGROUND

Basosquamous carcinoma is a rare malignancy, with features of both basal cell carcinoma and squamous cell carcinoma. Some authors believe that basosquamous carcinoma merely is a variant of basal cell carcinoma, whereas others have suggested that basosquamous carcinoma may behave more aggressively. To the authors' knowledge the largest published series to date, comprised of 35 cases, was reported >20 years ago. The authors reviewed their recent experience with basosquamous carcinoma to identify prognostic factors influencing recurrence.

METHODS

The medical records of all patients with the diagnosis of basosquamous carcinoma treated at the University of Louisville-affiliated hospitals between 1985-1988 were reviewed by a senior pathologist. Prognostic factors were analyzed using Cox regression analysis and the log rank test.

RESULTS

Thirty-one cases of basosquamous carcinoma were identified in 28 patients. The median age at diagnosis was 68 years (range, 10-94 years). The median follow-up was 60 months (range, 12-312 months). Seventy-five percent of cases were located on the face, neck, and scalp. One patient had regional lymph node metastasis synchronous with the primary tumor. Patterns of recurrence were: local recurrence only (five patients), local recurrence plus regional lymph nodes (three patients), and pulmonary plus regional lymph nodes (one patient). One patient died of pulmonary metastasis. Significant factors predictive of recurrence (P<0.01) were male gender, positive surgical resection margin, lymphatic invasion, and perineural invasion. Although tumor size was not a statistically significant factor overall (P = 0.076), the 3 patients with lymph node metastases had large tumors (measuring 2 cm, 5 cm, and 5 cm, respectively).

CONCLUSIONS

Basosquamous carcinoma is an aggressive epithelial neoplasm with a propensity for local recurrence and potential for distant metastatic spread. This behavior differs substantially from basal cell carcinoma. Complete resection with negative surgical margins is essential. Long term follow-up for the detection of local recurrence and distant metastatic spread is recommended.

Giant cell tumor of tendon sheath, tenosynovial giant cell tumor, and pigmented villonodular synovitis: defining the presentation, surgical therapy and recurrence

Giant cell tumor of the tendon sheath (GCTTS), tenosynovial giant cell tumor (TGCT), and pigmented villo-nodular synovitis (PVNS) are the common names for a group of rare proliferative disorders that involve synovial joints and tendon sheaths. Considerable confusion exists about the surgical treatment and diagnosis of these disorders. This review evaluates the presentation, surgical therapy and recurrence of these three proliferative disorders. We retrospectively reviewed the clinical data from all cases of GCTTS, TGCT, and PVNS from 1985 to 1997. A total of 35 patients were identified: GCTTS (n=8), TGCT (n=1), and PVNS (n=26), there were 18 men and 17 women. The median age was 48 years (range 6-84 years). The most common site of involvement was the knee (15), followed by wrist (7), elbow (4), and hip (4). Seven patients had extra-articular involvement, and 19 were found incidentally at operations for other reasons. Among the 4 patients who developed recurrent disease, 2 had extra-articular disease at the time of their original diagnosis. None died, and none required major amputation. One patient was treated with adjuvant radiotherapy following resection of a recurrence. It is important to distinguish between focal and diffuse forms of synovial involvement. If focal, simple surgical excision is appropriate. If diffuse, complete synovectomy is indicated for disease confined to the joint, and resection of all gross disease is indicated for extra-articular disease. Radical resection with negative margins is not necessary in most instances. In rare aggressive cases, local recurrence may necessitate more extensive resection and radiation therapy.

Initial neck exploration for untreated hyperparathyroidism

This study represents the experience of the Department of Surgery at the University of Louisville over a 21-year interval. Many aspects of surgical management of hyperparathyroidism have changed over the last 2 decades; controversies regarding the extent of exploration and the value of preoperative localization studies remain unresolved. One hundred ninety-three patients underwent neck exploration for hyperparathyroidism from 1976 to 1997. Data were collected from four University of Louisville-affiliated hospitals by independent evaluators. One hundred sixty patients with untreated hyperparathyroidism underwent neck exploration. Preoperative localization was carried out in 52 per cent (83 of 160). The exact location of the abnormal gland was indicated in 55 per cent (46 of 83), and the correct side of the neck was identified in 74 per cent (61 of 83). Technetium sestamibi scan was most reliable and identified the abnormality in 83 per cent (24 of 29). The average operative time with preoperative localization was 118 minutes compared with 137 minutes without preoperative localization. Intraoperative methylene blue was used in 42 of 160 neck explorations. Average operative time with methylene blue was 102 minutes compared with 124 minutes without methylene blue. Thirty-seven per cent (59 of 160) of patients underwent unilateral neck exploration. Sixty-three per cent (101 of 160) underwent bilateral exploration. Successful exploration was conducted in 98 per cent of the unilateral group and 91 per cent of the bilateral group. Postoperative local complications were essentially the same in both groups (3%), whereas temporary hypocalcemia occurred in 24 per cent (24 of 101) of the bilateral group compared with 3 per cent (2 of 59) of the unilateral group. We conclude that neck exploration for hyperparathyroidism is a highly successful, safe treatment with no mortality and minimal morbidity. Preoperative localization studies modestly reduced the duration of surgery without improving outcome.

Limb and hemispatial hypometria

In a previous study, we demonstrated that unilateral cerebral lesions produce hypometric limb movements of the contralateral arm and hemispatial (i.e., directional) hypometria for movements towards contralateral hemispace. In the present study, we investigated 10 patients with right cerebral lesions and 25 healthy controls using a task to uncouple deficits in sensory perceptual systems and motor-action output systems on directional hypometria. This task required participants, with their eyes closed, to reproduce lateral and medial horizontal displacements (15-27 cm) with each arm. Each participant was seated at a waist high table and had their hand placed at an origin point aligned with the axillary fold on the same side. Their hand was moved by the investigator from the origin point to a target point and brought back to the point of origin (input displacement). The participant was then asked to return their hand to either the same target point or to an equidistant target point in the opposite direction. Healthy dextral participants were significantly more hypometric with their right arm, but patients with right cerebral lesions exhibited an opposite pattern with overall left arm hypometria. In addition, patients were significantly more hypometric for movements when output displacements were toward left hemispace. No effect was found for direction of sensory input. The results suggest that the directional hypometria is predominantly produced by hemispatial output deficits.

Cognitive correlates of 1H MRSI-detected hippocampal abnormalities in temporal lobe epilepsy

OBJECTIVES

To examine associations between 1H magnetic resonance spectroscopic imaging (1H MRSI)-detected hippocampal creatine to N-acetylaspartate (Cr/NAA) ratios and neuropsychological measures sensitive to mesial temporal lobe function.

BACKGROUND

The measurement of 1H MRSI-detected hippocampal metabolites has proved effective in determining extent and lateralization of neuronal damage. However, relationships between 1H MRSI-detected hippocampal metabolic abnormalities and specific areas of cognitive functioning have received limited attention compared to other studies using MRI volumetry or cerebral blood flow techniques.

METHODS

We analyzed right and left hippocampal Cr/NAA ratios in 46 adult mesial temporal lobe epilepsy patients (32 left, 14 right) by 1H MRSI at high magnetic field (4.1 T). We examined the relationship between the right and left Cr/NAA hippocampal ratios to measures of verbal and visual memory, intelligence, attention, visuoperception, and confrontation naming.

RESULTS

Measures of episodic verbal memory (n = 33) and visual confrontation naming (n = 46) were selectively associated with left hippocampal metabolic function (p<0.004), whereas neuronal function of the right hippocampal region was strongly associated with performance on a measure of facial recognition (n = 46; p<0.02).

CONCLUSIONS

This study shows that specific areas of cognitive function are related to hippocampal neuronal metabolic abnormalities as detected by spectroscopic imaging. The current study indicates that 1H MRSI offers a complimentary technique to structural imaging studies in the study of mesial temporal lobe epilepsy and may enhance understanding of the role of hippocampal function in complex cognitive systems.

The relation of phoneme discrimination, lexical access, and short-term memory: A case study and interactive activation account

A brain-damaged patient (AP) is reported who had a strong tendency to identify nonwords as words on auditory lexical decision and to lexicalize nonwords in repetition, yet who showed a normal ability to perceive individual phonemes. It was initially hypothesized that these findings could be accounted for in terms of disrupted lexical phonological representations. This hypothesis was rejected on the basis of an interactive activation model of word recognition which revealed that modifications at the lexical level did not mimic the patient's pattern of results. Instead, it was found that increasing the rate of decay of activation at the phoneme level produced output that was consistent with the phoneme discrimination, lexical decision, and repetition results. This hypothesis of increased phoneme level decay led to the prediction that speech discrimination would decline with increased interstimulus interval and that short-term memory performance would be impaired. Both predictions were confirmed. The results of this study provide support for an interactive activation model of word recognition with feedback from the lexical to the phonemic level and for a close connection between the processes involved in word recognition and short-term memory.

Subjective versus objective memory change after temporal lobe epilepsy surgery

OBJECTIVE

To examine subjective versus objective memory change after anterior temporal lobectomy (ATL).

METHODS

A prospective, controlled study. Controls included 39 unoperated patients with intractable temporal lobe epilepsy (TLE) who were administered a series of cognitive and health-related quality of life measures at baseline and at 12-month follow-up intervals. The surgery sample included 65 patients with intractable, focal TLE who had undergone either a right or left ATL. These patients were tested preoperatively and at 6-month follow-up intervals. Subjective and objective memory change was quantified using a newly developed methodology to control for practice effect and regression to the mean.

RESULTS

Measures of subjective and objective memory change were not significantly related in the surgery sample. Prevalence of significant subjective memory decline 1 year after surgery ranged from 3 to 7%, whereas prevalence of significant objective memory decline ranged from 26 to 55%. Postoperative levels of emotional distress significantly predicted self-reported memory decline 1 year after ATL. Postoperative medication side effect and seizure outcome were also related significantly to subjective memory change in patients who had undergone left ATL.

CONCLUSIONS

Subjective and objective memory change after temporal lobectomy are not related. Complaints of significant memory decline after ATL are infrequent and may serve as a marker for depression or other mood disorder rather than organically based memory decline.

MRI extrahippocampal volumes and visual memory: correlations independent of MRI hippocampal volumes in temporal lobe epilepsy patients

Limbic system atrophy and memory dysfunction are common in patients with temporal lobe epilepsy (TLE). However, the relationship between extrahippocampal limbic structures and memory functioning within TLE has received little attention. The present study examined associations of MRI volumetric measurements of the mammillary body, fornix, amygdala, and hippocampus to measures of episodic verbal and visual memory. The Logical Memory and Visual Reproduction subtests from the Wechsler Memory Scale were administered to 47 unilateral TLE patients (25 right, 22 left). Normalized right and left MRI volumes were determined for each patient by cursor tracing 1.5 mm slices from 3D-MRI. Significant associations were found between left hippocampal volume and the immediate, delayed, and percent retention scores of the Logical Memory Test; between the left mammillary body volume and the Logical Memory Test delayed and percent retention scores; immediate Visual Reproduction performance was significantly related to the right and left amygdala volumes, and right mammillary body volume; only the right amygdala and right mammillary body volume were associated with the delayed Visual Reproduction trial. However, neither right nor left hippocampal volumes were related to visual memory performance. Multiple limbic system structural volumes were independently associated with verbal and nonverbal memory performance. Results suggest that visual memory, as measured by the Visual Reproduction Test, may be uniquely associated with extrahippocampal volumes in patients with TLE.

Intracellular measurement of prostaglandin E2: effect of anti-inflammatory drugs on cyclooxygenase activity and prostanoid expression

Cyclooxygenase (COX) converts arachidonic acid to prostaglandin (PG) H2, which is further metabolized to various prostaglandins, prostacyclin and thromboxane A2. COX exists in at least two different isoforms. COX-1 is constitutively expressed, whereas COX-2 is induced by proinflammatory stimuli. Prostaglandin E2 is a major metabolite of COX activation. In order to compare the activity of target ligands and COX inhibitors on PGE2 synthesis and release, the responsiveness of several cell lines to the calcium ionophore A23187, bacterial lipopolysaccharide (LPS), nonsteroidal anti-inflammatory drugs (NSAIDs), and the glucocorticoid, dexamethasone, were investigated. For intracellular measurements, the culture supernatant was aspirated, and the cells were thoroughly washed and lysed with dodecyltrimethylammonium bromide. Intracellular and secreted PGE2 were measured with an enzyme immunoassay. A23187 and LPS increased intracellular PGE2 in a dose-dependent manner. Kinetic experiments with A23187-stimulated mouse 3T3 fibroblast cells revealed a distinct biphasic response in COX activity. In the presence of NSAIDs or dexamethasone, there was a dose-dependent inhibition in intracellular PGE2 with A23187-stimulated 3T3 cells. Inhibitory studies demonstrated an apparent increased sensitivity of COX activity to the action of inhibitors when measuring intracellular PGE2 compared with using cell culture supernatants. Indeed, intracellular PGE2 levels were comprehensively reduced in the presence of low concentrations of inhibitor. The utilization of cell culture lysates and, in particular, measurement of intracellular PGE2 should prove useful for identifying new COX inhibitors.

Semantic and phonological codes interact in single word production

The relationship between semantic-syntactic and phonological levels in speaking was investigated using a picture naming procedure with simultaneously presented visual or auditory distractor words. Previous results with auditory distractors have been used to support the independent stage model (e.g., H. Schriefers, A. S. Meyer, & W. J. M. Levelt, 1990), whereas results with visual distractors have been used to support an interactive view (e.g., P.A. Starreveld & W. La Heij, 1996b). Experiment 1 demonstrated that with auditory distractors, semantic effects preceded phonological effects, whereas the reverse pattern held for visual distractors. Experiment 2 indicated that the results for visual distractors followed the auditory pattern when distractor presentation time was limited. Experiment 3 demonstrated an interaction between phonological and semantic relatedness of distractors for auditory presentation, supporting an interactive account of lexical access in speaking.

A gene encoding the cytokinin enzyme zeatin O-xylosyltransferase of Phaseolus vulgaris

Zeatin is the most active and ubiquitous form of the naturally occurring cytokinins. Glycosyl conjugates of zeatin are found in many plant tissues and are considered important for storage and protection against degradative enzymes. Two enzymes catalyzing the formation of O-glycosyl derivatives of zeatin have been characterized, O-glucosyltransferase and O-xylosyltransferase, occurring in seeds of lima bean (Phaseolus lunatus) and bean (Phaseolus vulgaris), respectively. Recently, the ZOG1 gene (zeatin O-glucosyltansferase) was isolated from P. lunatis (). Based on the ZOG1 sequence, the ZOX1 gene (zeatin O-xylosyltransferase) was cloned from P. vulgaris. ZOX1 contains an open reading frame of 1362 bp that codes for a 454-amino acid peptide of 51 kD. The recombinant protein has properties identical to the native enzyme: it catalyzes O-xylosylzeatin formation with UDP-Xyl as a glycosyl donor but does not recognize UDP-Glucose as a substrate. The ZOX1 and ZOG1 genes exhibit 93% identity at the nucleotide level and 90% similarity at the amino acid level. Neither gene contains introns. These zeatin-specific genes and their promoters will be useful for studies of the regulation of active versus storage forms of cytokinins. Comparison of sequences encoding similar enzymes with distinct substrate specificity may lead to identification of epitopes specific to cytokinin and glycosyl donor molecules.

Semantic and phonological codes interact in single word production

The relationship between semantic-syntactic and phonological levels in speaking was investigated using a picture naming procedure with simultaneously presented visual or auditory distractor words. Previous results with auditory distractors have been used to support the independent stage model (e.g., H. Schriefers, A. S. Meyer, & W. J. M. Levelt, 1990), whereas results with visual distractors have been used to support an interactive view (e.g., P.A. Starreveld & W. La Heij, 1996b). Experiment 1 demonstrated that with auditory distractors, semantic effects preceded phonological effects, whereas the reverse pattern held for visual distractors. Experiment 2 indicated that the results for visual distractors followed the auditory pattern when distractor presentation time was limited. Experiment 3 demonstrated an interaction between phonological and semantic relatedness of distractors for auditory presentation, supporting an interactive account of lexical access in speaking.

Isolation of a cytokinin gene, ZOG1, encoding zeatin O-glucosyltransferase from Phaseolus lunatus

Zeatin is the most active and ubiquitous of the naturally occurring cytokinins. The O-glucoside of zeatin, found in all plants examined, is considered to be important in cytokinin transport, storage, and protection against cytokinin oxidases. The enzyme UDPglucose:zeatin O-glucosyltransferase (EC 2.4.1.203) was previously isolated from Phaseolus lunatus seeds. Immunoscreening of an expression library with monospecific antibody resulted in the isolation of a cDNA encoding the enzyme. The recombinant protein efficiently converts labeled zeatin to O-glucosylzeatin and has properties similar to the native enzyme. The cDNA of 1.5 kb contains an ORF encoding a 51. 4-kDa polypeptide of 459 amino acids. The sequence is unique based on a BLAST search of data bases. The genomic sequence, isolated with PCR using specific primers based on the cDNA sequence, does not contain introns. The cloning of this gene provides the tools for further study of the regulation of cytokinin metabolism and analysis of the precise role of O-glucosylzeatin in plant development.

Clinical brachytherapy with neutron emitting 252Cf sources and adherence to AAPM TG-43 dosimetry protocol

Using Monte Carlo methods, neutron dosimetry for 252Cf Applicator Tube (AT) type medical sources available from Oak Ridge National Laboratory (ORNL) has for the first time been determined in terms of TG-43 formalism. This approach, as compared to previous "along-away" formalisms, demonstrates the relative angular independence of dose rate data, when the geometry factor has been removed. As the ORNL-made 252Cf AT type sources are considerably physically larger than most clinical sources used today, the radial dose function increases for radii less than 3.0 mm due to breakdown of the line source model. A comparison of the 252Cf neutron radial dose function with those for other medical sources revealed similarities with that from 137Cs. Differences with respect to previous 252Cf AT source neutron dosimetry data generally increased at increasing distances. This was attributed to differences in the various 252Cf AT source models and phantom compositions. The current status of 252Cf medical source fabrication and calibration procedures at ORNL is presented.

The representation of sublexical orthographic-phonologic correspondences: evidence from phonological dyslexia

Although there is considerable evidence that grapheme and body units are involved in assembling phonology from print, there is little evidence supporting the involvement of syllabic representations. We provide evidence on this point from a phonological dyslexic patient (ML) who, as a result of brain damage, is relatively unable to read nonwords. ML was found to be able to perform tasks assumed to reflect processes involved in assembled phonology (i.e. segmentation, orthographic-phonologic conversion, and blending) when the units involved were syllables, but demonstrated considerable difficulty when they were onset, body, or phoneme units. Additionally, both ML and matched controls were much better able to find words in an anagrams task (Treiman & Chafetz, 1987) when they resulted from the combination of segments corresponding to syllables than when they did not. It is suggested that the relationship between print and sound is represented at multiple levels (including the syllable) (Shallice, Warrington, & McCarthy, 1983) and that ML's nonword reading impairment is the result of disruption of representations below the level of the syllable.

Individual memory change after anterior temporal lobectomy: a base rate analysis using regression-based outcome methodology

PURPOSE

To characterize patterns of base rate change on measures of verbal and visual memory after anterior temporal lobectomy (ATL) using a newly developed regression-based outcome methodology that accounts for effects of practice and regression towards the mean, and to comment on the predictive utility of baseline memory measures on postoperative memory outcome.

METHODS

Memory change was operationalized using regression-based change norms in a group of left (n = 53) and right (n = 48) ATL patients. All patients were administered tests of episodic verbal (prose recall, list learning) and visual (figure reproduction) memory, and semantic memory before and after ATL.

RESULTS

ATL patients displayed a wide range of memory outcome across verbal and visual memory domains. Significant performance declines were noted for 25-50% of left ATL patients on verbal semantic and episodic memory tasks, while one-third of right ATL patients displayed significant declines in immediate and delayed episodic prose recall. Significant performance improvement was noted in an additional one-third of right ATL patients on delayed prose recall. Base rate change was similar between the two ATL groups across immediate and delayed visual memory. Approximately one-fourth of all patients displayed clinically meaningful losses on the visual memory task following surgery. Robust relationships between preoperative memory measures and nonstandardized change scores were attenuated or reversed using standardized memory outcome techniques.

CONCLUSIONS

Our results demonstrated substantial group variability in memory outcome for ATL patients. These results extend previous research by incorporating known effects of practice and regression to the mean when addressing meaningful neuropsychological change following epilepsy surgery. Our findings also suggest that future neuropsychological outcome studies should take steps towards controlling for regression-to-the-mean before drawing predictive conclusions.

Improved health care resource utilization following video-EEG-confirmed diagnosis of nonepileptic psychogenic seizures

The economic burden of epilepsy is well recognized. However, empirical investigation establishing costs associated with the diagnosis and treatment of non-epileptic psychogenic seizures (NEPS) is lacking. We studied 20 patients with video/EEG monitoring-confirmed NEPS to determine the effect of definitive diagnosis and treatment on medical costs and utilization. A medical resource utilization questionnaire and inpatient medical chart review were employed to calculate utilization information. Medication usage, outpatient visits, emergency room admissions, and diagnostic testing over a 6-month pre-diagnosis and a 6-month post-diagnosis period were compared. There was an 84% average reduction in total seizure-related medical charges in the 6 months following NEPS diagnosis. Average diagnostic testing charges declined 76%, average medication charges decreased 69%, outpatient clinic visits declined 80%, and emergency room visits reduced by 97%. A majority of patients obtaining a definitive inpatient video/EEG-seizure-monitoring-confirmed NEPS diagnosis experience substantial reductions in health care utilization and dollar costs.

Expression of the yeast FRE genes in transgenic tobacco

Two yeast genes, FRE1 and FRE2 (encoding Fe(III) reductases) were placed under the control of the cauliflower mosaic virus 35S promoter and introduced into tobacco (Nicotiana tabacum L.) via Agrobacterium tumefaciens-mediated transformation. Homozygous lines containing FRE1, FRE2, or FRE1 plus FRE2 were generated. Northern-blot analyses revealed mRNA of two different sizes in FRE1 lines, whereas all FRE2 lines had mRNA only of the expected length. Fe(III) reduction, chlorophyll contents, and Fe levels were determined in transgenic and control plants under Fe-sufficient and Fe-deficient conditions. In a normal growth environment, the highest root Fe(III) reduction, 4-fold higher than in controls, occurred in the double transformant (FRE1 + FRE2). Elevated Fe(III) reduction was also observed in all FRE2 and some FRE1 lines. The increased Fe(III) reduction occurred along the entire length of the roots and on shoot sections. FRE2 and double transformants were more tolerant to Fe deficiency in hydroponic culture, as shown by higher chlorophyll and Fe concentrations in younger leaves, whereas FRE1 transformants did not differ from the controls. Overall, the beneficial effects of FRE2 were consistent, suggesting that FRE2 may be used to improve Fe efficiency in crop plants.

Multiple interference effects in short-term recognition memory

Five experiments, using a probe recognition procedure, examined the codes involved in short-term memory. Interference effects were obtained for probes with an orthographic, associative, or semantic relationship to a memory set item. The orthographic interference effects appeared to result from matches on the basis of abstract letter codes (i.e., graphemes) rather than overlap of visual features. The associative and semantic effects differed from what might be predicted on the basis of spreading activation, suggesting that these effects are qualitatively different from semantic priming effects observed in lexical decision tasks. These results support models of short-term memory in which items are represented as groups of features and recognition depends on a comparison of the features of the probe to those of the memory set items.

Contribution of neuropsychological data to the prediction of temporal lobe epilepsy surgery outcome

PURPOSE

We empirically examined the contribution of neuropsychological data to the prediction of postoperative seizure control relative to base rate information in an existing series of patients undergoing anterior temporal lobectomy (ATL).

METHODS

A discriminant function predicting surgery outcome (seizure-free vs. non-seizure-free) was computed separately for samples of patients with left (n = 79) and right (n = 62) temporal lobectomy (LATL, RATL). Predictor variables included 14 measures tapping five neurocognitive domains. The predicted base rates were compared with the actual base rates in the two samples. Finally, overall predictive accuracy was examined in optimal versus suboptimal ATL patients.

RESULTS

The base rate of seizure freedom in the LATL group was 74.70%; that in the RATL group was 66.10%. The predictive function for the LATL group achieved a hit rate of 80.00% and a positive predictive power of 92.11%. The function for the RATL group achieved a hit rate of 83.33% and a positive predictive power (PPP) of 89.66%. The overall predictive accuracy for the optimal group was only 55%, but that in the suboptimal group was 72%.

CONCLUSIONS

Neuropsychological data used in a multivariate statistical fashion may be able to offer an incremental increase in the prediction of postoperative seizure freedom relative to existing base rates of surgery success in patients with ATL epilepsy. The use of neuropsychological data may be of greatest predictive value in a population of ATL candidates with suboptimal findings with a lower base rate of postoperative seizure freedom, but may actually reduce predictive accuracy in a group of ATL candidates from an optimal population with an already high base rate of surgical success.

Mobile mammography screening: the James Graham Brown Cancer Center three year experience. Implications for public and professional education

OBJECTIVE

Review the mobile mammography screening experience at the James Graham Brown Cancer Center during a 3 year interval.

METHODS

Collect and analyze demographic and outcome data on the screened population.

RESULTS

4,864 women underwent two-view mammograms. One third of the mammograms were performed in women over 50 years of age. 232 mammograms were carried out per cancer detected. The number of mammograms per cancer detected was 2.5 times higher and the number of biopsies per cancer detected was 2.8 times higher in women under 50 years of age. Two thirds of the cancers detected were in the over 50 age group which represents one third of the study population.

CONCLUSIONS

In this study, mammographic screening for breast cancer was more cost effective because a higher yield of cancers detected was obtained with fewer mammograms and fewer breast biopsies in women over 50 years of age, compared to women under 50 years. Resolving the question of the cost effectiveness of screening women aged 40 to 49, will require a large randomized prospective trial. In the near term, rather than to dwell on this issue, we would propose that this study suggests the need for greater emphasis in both public and professional education on breast cancer detection directed to women over 50 years of age.