Methylphenidate increased regional cerebral blood flow in subjects with attention deficit/hyperactivity disorder

The regional cerebral blood flow (rCBF) responses to methylphenidate (MPH) treatment were examined in children with attention deficit/hyperactivity disorder (ADHD). Thirty-two male children, diagnosed with ADHD by the DSM-IV diagnostic criteria, other behavioral assessment scales and neuropsychological battery, were studied using 99mTc-HMPAO-single photon emission computed tomography (SPECT). Subjects were studied before and after MPH treatment. First, using an image subtraction method, we obtained a NDR parametric image of each patient and found increased cerebral blood flow in the frontal lobes, caudate nuclei and thalamic areas after treatment. When the changes in SPECT and clinical response were compared, the matching rate, sensitivity and specificity between them were found to be 77.1, 80.0 and 79.2%, respectively. Second, three transaxial brain slices delineating anatomically defined regions of interest (ROI) at 20, 40, and 60mm above the orbitomeatal line (OML) were used, with the average number of counts for each region of interest normalized to the area of the cerebellar maximal uptake. The left and right prefrontal areas, and caudate and thalamic areas showed significant increases in rCBF after MPH treatment. These findings suggested MPH could affect the function of the fronto-striato-thalamic circuit, which is known as the pathophysiologic site of ADHD and could be used to correct the underlying brain dysfunction of ADHD.

Determination of floral fragrances of Rosa hybrida using solid-phase trapping-solvent extraction and gas chromatography-mass spectrometry

Floral fragrances emanated from Rosa hybrida were determined by solid-phase trapping extraction and GC-MS. A novel protocol of sampling technique was established. There is a variation in the recoveries depending on the adsorbent and components. A total of 41 compounds were identified in the floral fragrances of Rosa hybrida. These include alcohols, aldehydes, alkanes, monoterpenes, sesquiterpene, esters, ether and ketones. Citral, n-nonane, n-butyl acetate, n-decane, beta-phenylethyl acetate and hexadecanol were major components. Floral fragrances differ between rose species and sample to sample within a single species. Interestingly, endocrine disruptors such as bis(2-ethylhexyl) phthalate were detected simultaneously.

Comparative study of single-injection, single-acquisition 99mTc-MIBI gated SPET and stress-rest perfusion SPET for the evaluation of myocardial viability after bypass surgery in coronary artery disease

In patients without previous myocardial infarction, the single-injection stress perfusion/rest function (SISPRF) approach using stress technetium-99m methoxyisobutylisonitrile (MIBI) gated single-photon emission tomography (SPET) can substitute for conventional stress-rest myocardial perfusion imaging for the assessment of myocardial viability. This study compared pre-operative single-injection, single-acquisition 99mTc-MIBI gated SPET and conventional stress-rest imaging for the prediction of myocardial viability in patients who underwent coronary artery bypass surgery (CABG). Rest thallium-201 SPET followed by stress 99mTc-MIBI gated SPET was performed in 20 patients [nine with previous myocardial infarction (MI) and 11 without previous MI). The study was performed before and 3 months after CABG, and viability assessment was validated by wall motion improvement after CABG. A four-point scoring system (0-3 for normal to absent tracer uptake) for 17 segments of the left ventricular myocardium was used for the assessment of stress and rest uptake. Wall motion, wall thickening and perfusion status were analysed by semi-quantitative visual assessment. On gated SPET, perfusion defect reversibility was considered present when a definite perfusion defect was observed and wall motion or thickening was normal or showed only a mild decrease. In patients with a previous MI, the left ventricular ejection fraction improved significantly after CABG (46% +/- 7% vs 42% +/- 11% before CABG, P < 0.05). In patients without previous MI, the ejection fraction improved significantly after CABG (50 +/- 12% vs 44% +/- 16% before CABG, P<0.05). In patients with previous MI, positive predictive values using the stress-rest reversibility and SISPRF approaches were 91% and 90%, respectively, and corresponding negative predictive values were 25% and 18%. In patients without previous MI, positive predictive values using the stress-rest and SISPRF approaches were 70% and 61%, respectively, and corresponding negative predictive values were 63% and 14%. It is concluded that SISPRF SPET study is of similar value to conventional stress-rest perfusion study in predicting wall motion improvement in patients with a previous MI, but that it is of limited value in predicting the myocardial viability of patients without previous MI, owing to a lower predictive value.

Reproducibility of assessment of myocardial function using gated 99Tc(m)-MIBI SPECT and quantitative software

PURPOSE

We investigated the reproducibility of the quantification of left ventricular volumes and ejection fraction, and grading of myocardial wall motion and systolic thickening with gated myocardial single-photon emission computed tomography (SPECT) and Cedars quantification software.

PATIENTS, MATERIALS AND METHODS

We performed post-stress gated myocardial SPECT in 33 consecutive patients twice sequentially in situ. Sixteen frames per cycle were used for gating. Using Cedars quantitative gated SPECT software ventricular volumes and ejection fraction (EF) were calculated. Wall motion and thickening was graded using 5- and 4-point scores, respectively. Coefficients of variation for re-examination of volumes and EF were calculated. Kappa values for assessing reproducibility of wall motion or wall thickening were calculated.

RESULTS

Root mean square of errors was 5.0 ml for end-diastolic volume, 3.9 ml for end-systolic volume and 1.9% for EF. No bias or difference was found between the first and second acquisition by Bland-Altman analysis. Kappa values for wall motion and thickening of repeated acquisition was 0.76 and 0.87, respectively. The value of 2 SD from Bland-Altman analysis was 14.4 ml for EDV, 11.2 ml for ESV and 5.3% for EF.

CONCLUSION

We conclude that quantification of functional indices and assessment of wall motion or thickening using gated 99Tc(m)-sestamibi (MIBI) SPECT was reproducible and we found that their ranges of physiological fluctuation were narrow enough.

Phase I clinical trial of a recombinant canarypoxvirus (ALVAC) vaccine expressing human carcinoembryonic antigen and the B7.1 co-stimulatory molecule

The generation of cytotoxic effector T cells requires delivery of two signals, one derived from a specific antigenic epitope and one from a costimulatory molecule. A phase I clinical trial was conducted with a non-replicating canarypoxvirus (ALVAC) constructed to express both human carcinoembryonic antigen (CEA) and the B7.1 costimulatory molecule. This was the first study in cancer patients to determine if the delivery of costimulation with a tumor vaccine was feasible and improved immune responses. Three cohorts of six patients, each with advanced CEA-expressing adenocarcinomas, were treated with increasing doses of an ALVAC-CEA-B7.1 vaccine (4.5 x 10(6), 4.5 x 10(7), and 4.5 x 10(8) plaque-forming units, PFU). Patients were vaccinated by intramuscular injection every 4 weeks for 3 months and monitored for side-effects, tumor growth and anti-CEA immune responses. ALVAC-CEA-B7.1 at doses up to 4.5 x 10(8) PFU was given without evidence of significant toxicity or autoimmune reactions. Three patients experienced clinically stable disease that correlated with increasing CEA-specific precursor T cells, as shown by in vitro interferon-gamma enzyme-linked immunoassay spot tests (ELISPOT). These three patients underwent repeated vaccination resulting in augmented CEA-specific T cell responses. This study represents the first use of costimulation to enhance antitumor vaccines in cancer patients. This approach resulted in CEA-specific immunity associated with stable diseases in three patients. This study also demonstrated that CEA-specific T cell responses could be sustained by repeated vaccinations. Although the number of patients was small, the addition of B7.1 to virus-based vaccines may improve immunological and stable diseases to vaccination against tumor-associated antigens with tolerable toxicity.

Role of self-major histocompatibility complex/peptide ligands in selection and maintenance of a diverse T cell repertoire

Positive selection has long been thought to be a devise for producing a repertoire of T cells that can efficiently recognize foreign peptides in the context of self-major histocompatibility complex (MHC) molecules. However, in the light of recent evidence that long-term survival of mature T cells requires continuous contact with self-MHC molecules, the possibility for an additional role for positive selection has emerged: to generate a repertoire of T cells that can be maintained in the periphery through contact with self-MHC/peptide ligands. In support of this idea, our recent work suggests that positive selection is highly peptide specific and, more important, that mature T cells require extrathymic contact with the same MHC/peptide ligands that initially induced positive selection in the thymus in order for prolonged survival and to undergo homeostatic proliferation in response to T cell deficiency.

CM1, a possible novel activation molecule on human lymphocytes

CM1 (centrocyte/-blast marker 1) defined by a mAb developed against concanavalin-A activated PBMC, is expressed specifically on some tonsillar germinal center (GC) B cells. In single flow cytometric analysis, the bone marrow did not express these molecules nor did the PBMC or the thymocytes. The peripheral B lymphocytes showed more than 90% positive, while the peripheral T lymphocytes showed approximately 60% positive at 48 h after activation by PMA/ionomycin, respectively. A western blot analysis and an immunoprecipitation for CM1 showed a band at 70 kDa. Cross-linking of CM1 with anti-CM1 mAb induced apoptosis of the GC B cells (CD38(+)IgD(-)). Immunohistochemical staining revealed that the CM1 molecule is distributed over the entire area except the proximal dark zone of the tonsillar germinal centers. These results suggest that the CM1 molecule might be involved in differentiation of the germinal center B cells as one of the novel centrocyte markers.

Interdomal fat pad: an important anatomical structure in rhinoplasty

OBJECTIVE

To describe the interdomal fat pad, an important anatomical structure that, to our knowledge, has not been reported in the rhinoplasty literature.

DESIGN

Anatomical observations were made during a consecutive series of external rhinoplasties, and the existence of the interdomal fat pad was documented in patients with noses of varying nasal skin thicknesses.

SETTING

Private facial plastic surgery practice.

PATIENTS

One hundred consecutive white patients undergoing external rhinoplasty were analyzed. Thirty-seven patients were undergoing secondary rhinoplasty and were excluded. Sixty-three patients undergoing primary rhinoplasty were enrolled into the study.

INTERVENTION

None.

MAIN OUTCOME MEASURES

The nasal skin type of each patient was subjectively determined preoperatively to be thin, average, or thick. The presence or absence of a distinct fat pad between the domes of the lower lateral cartilages was observed and recorded in each group of patients.

RESULTS

Among the 63 patients studied, 22 had thick skin; 31, average skin; and 10, thin skin. Well-defined interdomal fat pads were noted in 12 patients with thick skin, 13 patients with average skin, and 2 patients with thin skin.

CONCLUSIONS

There is a distinct anatomical structure that we refer to as the interdomal fat pad that exists in noses of all skin types. The awareness of this structure should encourage a careful and direct examination of the undersurface of nasal tip skin. An unrecognized, extensive fat pad may interfere with tip narrowing and refinement. It may be the cause of persistent postrhinoplasty supratip fullness and excessive tip width. Arch Facial Plast Surg. 2000;2:260-263

Late postictal residual perfusion abnormality in epileptogenic zone found on 6-hour postictal SPECT

BACKGROUND

Temporal evolution of regional hyperperfusion in the late postictal stage in epilepsy has not been clearly defined.

OBJECTIVE

To establish the late temporal evolution of the perfusion in epileptogenic zones using 6-hour postictal SPECT.

METHODS

Ictal 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) SPECT was performed in 10 patients with intractable epilepsy (4 temporal lobe epilepsy, 6 neocortical epilepsy) followed by delayed acquisition and another 6-hour postictal SPECT after reinjection of 99mTc-HMPAO. The delayed acquired SPECT was subtracted from the reinjection SPECT to yield the 6-hour postictal SPECT. Interictal SPECT was acquired on another day. Late postictal perfusion was examined visually, and asymmetric indexes were compared with each other on ictal, 6-hour postictal, and interictal SPECT.

RESULTS

Ictal SPECT images of delayed acquisition were visually and quantitatively similar to those of early acquisition. In 7 of 10 patients, 6-hour postictal SPECT showed hyperperfusion. In one patient, the 6-hour postictal SPECT image showed less perfusion than the interictal SPECT image in the epileptogenic zone.

CONCLUSIONS

Late postictal hyperperfusion was found in more than half of the patients. Postictal perfusion abnormalities did not come back to the interictal phase 6 hours after ictus and these were identified on ictal/postictal 99mTc- HMPAO SPECT.

The clinical usefulness of ictal SPECT in temporal lobe epilepsy: the lateralization of seizure focus and correlation with EEG

PURPOSE

To analyze the relationship between ictal electroencephalography (EEG) and ictal single-photon emission computed tomography (SPECT) and to evaluate the diagnostic usefulness of ictal SPECT as an independent presurgical evaluation technique.

METHODS

Sixty-eight patients with temporal lobe epilepsy who underwent temporal lobectomy with good surgical outcome were included in this study. Ictal SPECT was performed during video-EEG monitoring. The ictal EEG was analyzed in 5-second intervals from the initiation of the ictal rhythm. Lateralized EEG dominance was determined by the amplitude, frequency, or regional patterns of ictal rhythm for each 5-second interval. The total ictal EEG was divided into three periods: preinjection (maximum, 30 seconds), the initial part of the postinjection period (30 seconds), and the latter part of the postinjection period (30 to 60 seconds). The results of ictal SPECT were compared with the lateralized EEG dominance of each period and at seizure onset.

RESULTS

Fifty-four of 68 ictal EEGs correctly lateralized seizure focus ipsilateral to the side of surgery. Ictal SPECT correctly lateralized the epileptogenic temporal lobe in 61 of 68 patients (mean injection time, 29.8 seconds from onset). Multivariate analysis indicated that only the EEG dominance of the preejection period correlated significantly with the concordant hyperperfusion of ictal SPECT. Correct lateralization of ictal SPECT occurred in 10 of 14 patients with nonlateralized ictal EEG.

CONCLUSIONS

Preinjection neuronal activity seems to be important for the accurate interpretation of the hyperperfused patterns of ictal SPECT. Ictal SPECT is an independent and confirmatory presurgical evaluation technique.

Regulation of X11L-dependent amyloid precursor protein metabolism by XB51, a novel X11L-binding protein

We isolated a cDNA encoding a novel protein, XB51, that interacts with the amino-terminal domain of the neuron-specific X11-like protein (X11L). The protein XB51 inhibited the association of X11L with amyloid precursor protein through a non-competitive mechanism and abolished the suppression of beta-amyloid production by X11L. The majority of XB51 is localized around the nucleus and recovered in 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid (CHAPS) buffer-insoluble fraction when XB51 is expressed in cells. Association of XB51 with X11L changed the intracellular distribution of XB51 and resulted in redistribution of XB51 into the CHAPS buffer-soluble fraction. These observations suggest that XB51, together with X11L, plays an important role in the regulatory system of amyloid precursor protein metabolism and beta-amyloid generation.

A cost analysis of community screening for diabetes in the central Wisconsin Medicare population (results from the MetaStar pilot project in Wausau)

CONTEXT

Type 2 diabetes mellitus is often undiagnosed and untreated.

OBJECTIVE

To estimate the costs and possible savings of screening for Type 2 diabetes mellitus in the Wisconsin Medicare population from a population health perspective.

DESIGN

The costs and benefits of community screening were analyzed using various primary and secondary data sources. Data on the community screening were obtained by MetaStar, collaborators at the screening site, and published material. Results from a Monte Carlo simulation model, developed by the CDC Diabetes Cost-Effectiveness Study Group, and recent developments in diabetes research were used to estimate the incidence levels of major complications for Type 2 diabetes.

SETTING AND PARTICIPANTS

Medicare beneficiaries in central Wisconsin residing in the Wausau Hospital Service Area, which is composed of 14 zip codes.

RESULTS

Of 826 Medicare patients screened, 32 were diagnosed as having diabetes. If we use the same assumptions offered by the CDC Study Group, we find that the excess lifetime costs from screening and early treatment ($4850) exceed costs saved from preventing complications ($378), costing an average of $4471 per diabetic. However, if we alter assumptions on cardiovascular disease reduction risk and routine care costs, we find that screening could save an average of $619 per diabetic detected.

CONCLUSIONS

The costs of community screening, using the CDC Study Group's assumptions, are greater than the costs of diabetes without screening in this population. However, recent evidence on cardiovascular disease risk and routine care costs could alter the results, leading to lower costs and greater benefits in the future. More research is necessary, particularly in the area of quality of life measures, to more accurately reflect the benefits of screening.

A bcl-xS adenovirus selectively induces apoptosis in transformed cells compared to normal mammary cells

Oncogenes which drive the cell cycle, such as c-myc, can sensitize cells to apoptosis. This suggests the possibility that the expression of genes such as bcl-2 or bcl-xL is required to inhibit apoptosis induced by oncogene expression. We hypothesized that inhibition of Bcl-2/Bcl-xL by the pro-apoptotic Bcl-xS protein, would result in selective induction of apoptosis in mammary carcinoma cells compared to their nontransformed counterparts. Therefore, we compared the effects of Bcl-xS expression delivered by a bcl-xS adenovirus (bcl-xS-Adv) vector, on viability and apoptosis of nontransformed versus transformed mammary epithelial cells. We report that c-myc-transformed murine mammary cells are extremely sensitive to apoptosis induced by the bcl-xS adenovirus (bcl-xS-Adv) vector, whereas immortalized, nontransformed murine mammary cells are relatively resistant to apoptosis induced by this vector. Likewise, human mammary epithelial cells transduced with c-erbB-2 were more sensitive to apoptosis induced by the bcl-xS vector than the nontransformed parental cells. Similar results were obtained when we tested the effects of bcl-xS adenoviral infection on primary normal human mammary epithelial cells and SUM-190 PT cells, (a c-erbB-2 over-expressing human mammary carcinoma cell line) grown on Matrigel. These data are consistent with the hypothesis that inhibition of Bcl-2/Bcl-xL can result in selective killing of cancer cells compared to their nontransformed counterparts.

A bcl-x(S) adenovirus demonstrates therapeutic efficacy in an ascites model of human breast cancer

OBJECTIVES

To determine whether a Bcl-x(S) adenoviral vector has therapeutic potential in an ascites model of human breast cancer in nude mice.

METHODS

Advanced ascites were developed by injecting mice intraperitoneally (IP) with MDA-MB-231 human breast carcinoma cells. Mice received sequential IP injections of the Bcl-x(S) virus or a control lac-Z adenovirus. A third group of mice received no virus. Tumor burden and survival were monitored. Histopathology and necropsies were performed on mice.

RESULTS

A single injection of the Bcl-x(S) adenovirus produced no systemic or local toxicity and no abnormal histopathology in normal mice. However, abdominal organs within these mice were transduced with the Bcl-x(S) vector. Adenoviral gene transduction efficiency in MDA-MB-231 ascites was 36+/-6.40% (n = 3). Percent weight change differences revealed that ascites bearing mice injected three times with the Bcl-x(S) vector showed a statistically significant decrease in tumor burden compared with lac-Z-injected mice (n = 7; P = .012 on days 10-15 after the first injection). Mice injected with the Bcl-x(S) vector had significantly greater survival relative to lac-Z-injected mice (n = 7; P = .0004). Bcl-x(S) protein expression was detected in aspirates of mice injected with the Bcl-x(S) vector but not the lac-Z vector. Necropsies revealed that ascites bearing mice injected with Bcl-x(S) vector lacked carcinoma in the peritoneal cavity compared with control mice.

CONCLUSION

The Bcl-x(S) adenovirus can reduce tumor burden and increase survival in an ascites model of advanced stage breast cancer.

Pediatric intractable epilepsy: the role of presurgical evaluation and seizure outcome

Surgical experience with long-term follow-up is limited in childhood intractable epilepsy, compared with adult epilepsy. To assess the role of each presurgical evaluation modality and to identify prognostic factors for favorable seizure control after epilepsy surgery, 38 children with intractable epilepsy who underwent surgery were retrospectively reviewed. Among the available preoperative evaluation modalities, PET and neuropsychological testing showed the highest rates of positive results, whereas MRI was the most concordant with EEG findings. During a follow-up period of at least 12 months, 26 of the 38 patients showed favorable seizure control (Engel classifications I and II). The best seizure control was achieved in patients with a temporal resection and discrete lesion on magnetic resonance imaging. In spite of the invasive study, the less satisfactory results followed an extratemporal resection. We conclude that epilepsy surgery benefits children with intractable epilepsy and that the role of invasive study should be reestablished according to the area of resection and presence of discrete lesion on MRI.

Role of follicular dendritic cells in the apoptosis of germinal center B cells

Follicular dendritic cells (FDCs) provide the most obvious source of antigens, which are essential for the differentiation of GC B cells. It has been reported that most proliferating B cells in germinal centers undergo apoptosis. Quantitative histology shows macrophages with apoptotic debris throughout the germinal center, the highest frequency of these cells being found in the dense FDC network. Based on these findings, we hypothesized that FDC may be involved in an apoptotic pathway of the germinal center B cells. To prove this hypothesis, we performed double immunohistochemical analysis using anti-FDC mAb and peanut agglutinin (PNA), with their respective TUNEL kits. Collated data showed that a great proportion of the apoptotic cells, most of which were positive for PNA, were in close contact with FDC, which indicated an interaction between FDC and B cells in the apoptotic pathway. Further studies using double immunohistochemical staining and FACS analyses demonstrated the expression of Fas-ligand (FasL) in a subset of the FDC. These results suggest that FDC may play a role in the apoptosis of germinal center B cells via Fas-FasL interaction.

Limited incremental diagnostic values of attenuation-noncorrected gating and ungated attenuation correction to rest/stress myocardial perfusion SPECT in patients with an intermediate likelihood of coronary artery disease

Either gated myocardial perfusion SPECT or attenuation-corrected SPECT can be used to improve specificity in the diagnosis of coronary artery disease (CAD). We investigated whether attenuation-noncorrected gating and ungated attenuation correction could improve the diagnostic performance of rest/stress perfusion SPECT in patients having an intermediate pretest likelihood of CAD.

METHODS

Sixty-eight patients (29 men, 39 women; mean age, 59 +/- 12 y) with coronary artery stenosis > or =70% (1 vessel, n = 13; 2 vessels, n = 18; 3 vessels, n = 8; normal, n = 29) underwent rest attenuation-corrected 201TI SPECT and dipyridamole stress gated attenuation-corrected 99mTc-methoxyisobutyl isonitrile SPECT with an ADAC vertex camera. Three physicians graded the post-test likelihood of CAD for each arterial territory using a 5-point scale (1, normal; 2, possibly normal; 3, equivocal; 4, possibly abnormal; 5, abnormal). The sensitivity, specificity, and areas under receiver-operating-characteristic curves were compared for each operator by 3 methods: attenuation-noncorrected rest/stress SPECT, gated poststress SPECT plus attenuation-noncorrected rest/stress SPECT, and attenuation-corrected rest/stress SPECT plus gated poststress SPECT plus attenuation-noncorrected rest/stress SPECT.

RESULTS

When higher than grade 3 was used as the criterion for CAD, no differences in sensitivity and specificity were found among the 3 methods for each operator. Areas under receiver-operating-characteristic curves for the diagnosis of CAD and stenosis revealed no differences for each modality (P > 0.05 for each comparison).

CONCLUSION

In patients with an intermediate risk of CAD, viewing attenuation-noncorrected gated poststress SPECT and ungated attenuation-corrected rest/stress SPECT images did not improve the diagnostic performance for CAD and stenosis.

Preparation of rhenium-188-tin colloid as a radiation synovectomy agent and comparison with rhenium-188-sulfur colloid

As a generator-produced beta-emitting radionuclide, the importance of 188Re for radionuclide therapy is increasing rapidly. We prepared 188Re-tin colloid and compared its properties with 188Re-sulfur colloid. Labeling efficiencies reached >98% for tin colloid at 2 h and 89-94% for sulfur colloid at 3 h. All the preparations were stable for 72 h in water, serum, and synovial fluid. If labeled at higher temperature, the particle size of tin colloid increased. The residual radioactivity of 188Re-sulfur colloid in disposable polypropylene syringes after injecting mice was high (62.0+/-7.0%) due to its hydrophobic nature, while that of 188Re-tin colloid was low (2.9+/-1.6%). Although both 188Re-tin colloid and 188Re-sulfur colloid might be useful for radionuclide therapy, we conclude that 188Re tin colloid is more advantageous over 188Re sulfur colloid, due to higher labeling efficiency, control of the particle size, and lower residual activity in the injection syringes.

Localization of epileptogenic zones in F-18 FDG brain PET of patients with temporal lobe epilepsy using artificial neural network

For an objective interpretation of cerebral metabolic pattern to find epileptogenic zones in patients with temporal lobe epilepsy (TLE), we developed a computer-aided classifier using an artificial neural network (ANN). We studied 261 epilepsy patients diagnosed as no abnormal findings (NA, n = 64), left TLE (n = 116), or right TLE (n = 81) on interictal brain F-18-fluorodeoxyglucose positron emission tomography (FDG PET) by the consensus of two expert physicians. Seventeen asymmetry indexes between the mean counts of the 34 mirrored regions were extracted from the spatially normalized images and used as input parameters. The three diagnoses of NA, left TLE, and right TLE were used as outputs of the ANN. The structure of the ANN was optimized with variable error goals and the number of hidden units. On the criteria of agreement of diagnoses with those of expert viewers, the best classifier was chosen, which yielded a maximum average agreement of 85% for the test set when we used an error goal of 20 (sum of squared error) and ten hidden units. We could devise an ANN that performed as well in diagnosing left or right TLE on FDG PET as human experts and could be used as a clinical decision support tool.

Differential regulation of apoptosis in normal versus transformed mammary epithelium by lutein and retinoic acid

We examined the effects of all-trans retinoic acid (ATRA) and lutein (a nonprovitamin A carotenoid), on apoptosis and chemosensitivity in primary normal human mammary epithelial cells, SV40 transformed mammary cells, and MCF-7 human mammary carcinoma cells. ATRA and lutein selectively induced apoptosis in transformed but not normal human mammary cells. In addition, both compounds protected normal cells, but not transformed cells, from apoptosis induced by the chemotherapy agents etoposide and cisplatin. Furthermore, lutein and ATRA selectively increased the ratio of Bcl-xL:Bax protein expression in normal cells but not transformed mammary cells, suggesting a possible mechanism for selective modulation of apoptosis. The differential effects of lutein and ATRA on apoptotic pathways in normal versus transformed mammary epithelial cells may have important implications for chemoprevention and therapy.

Pre-operative teaching: how does a group of nurses do it?

Studies have revealed that adequate pre-operative instructions alleviate anxiety, increase patient participation in their care and minimize the development of post-operative complications. However, other researches have found that there are discrepancies between nurses' perceptions of patient's pre-operative needs and patients' actual needs. The aim of this study is to gain insight into how a group of surgical ward nurses organize and implement their pre-operative teaching, and the difficulties they have encountered. It explores how a group of surgical ward nurses conduct pre-operative teaching to their patients. It has found that their training, rote learning, and the timing of patient admissions have all affected how participating nurses organize and implement their pre-operative teaching to their patients. This case study acts as an exemplar to other nurses, to stimulate reflection on their own practice.

Limited performance of quantitative assessment of myocardial function by thallium-201 gated myocardial single-photon emission tomography

We investigated the reproducibility between thallium-201 and technetium-99m methoxyisobutylisonitrile (MIBI) gated single-photon emission tomography (SPET) for the assessment of indices of myocardial function such as end-diastolic and end-systolic volume (EDV, ESV), ejection fraction (EF) and wall motion. Rest 201Tl (111 MBq) gated SPET was sequentially performed twice in 20 patients. Rest 201Tl gated SPET and rest 99mTc-MIBI (370 MBq) gated SPET were performed 24 h apart in 40 patients. Wall motion was graded using the surface display of the Cedars quantitative gated SPET (QGS) software. EDV, ESV and EF were also measured using the QGS software. The reproducibility of functional assessment on rest 201Tl gated SPET was compared with that on 99mTc-MIBI gated SPET, and also with that between 201Tl gated SPET and 99mTc-MIBI gated SPET performed on the next day. The two standard deviation (2 SD) values for EDV, ESV and EF on the Bland-Altman plot were 29 ml, 19 ml and 12%, respectively, on repeated 201Tl gated SPET, compared with 14 ml, 11 ml and 5.3% on repeated 99mTc-MIBI gated SPET. The correlations were good (r=0.96, 0.97 and 0.87) between the two measurements of EDV, ESV and EF on repeated rest studies with 201Tl and 99mTc-MIBI gated SPET. However, Bland-Altman analysis revealed that the 2 SD values between the two measurements were 31 ml, 23 ml and 12%. We were able to score the wall motion in all cases using the 3D surface display of the QGS on 201Tl gated SPET. The kappa value of the wall motion grade on the repeated 201Tl study was 0.35, while that of the wall motion grade on the repeated 99mTc-MIBI study was 0.76. The kappa value was 0.49 for grading of wall motion on repeated rest studies with 201Tl and 99mTc-MIBI. In conclusion, QGS helped determine EDV, ESV, EF and wall motion on 201Tl gated SPET. Because the EDV, ESV and EF were less reproducible on repeated 201Tl gated SPET or on 201Tl gated SPET and 99mTc-MIBI gated SPET on the next day than on repeated 99mTc-MIBI gated SPET, functional measurement on 201Tl gated SPET did not seem to be interchangeable with that on 99mTc-MIBI gated SPET.

Dosimetry of rhenium-188 diethylene triamine penta-acetic acid for endovascular intra-balloon brachytherapy after coronary angioplasty

To examine the possibility of using rhenium-188 diethylene triamine penta-acetic acid (DTPA) for endovascular intra-balloon brachytherapy after angioplasty, dose distribution around the balloon was calculated and validated by film dosimetry. Medical internal radiation dosimetry (MIRD) was calculated assuming that the balloon had ruptured and that the contents had been released into the systemic circulation. 188Re-perrhenate eluate from the 188W/188Re generator was concentrated using an ion column and used to label DTPA. The dose distribution around the angioplasty balloon (20 mm length, 3 mm diameter cylinder) was estimated by Monte Carlo simulation using the EGS4 code. The time required for 17.6 Gy to be absorbed at 1 mm from the balloon's surface following application of 3700 MBq/ml of 188Re was found to be 278 s. Fifty percent of the energy was deposited in the first millimetre of the vessel wall from the balloon's surface. The calculated radiation absorbed dose agreed with that measured by film dosimetry, which was performed using a water phantom, with errors ranging from 9.4% to 17%. Upon balloon rupture the total amount of 188Re-DTPA was presumed to enter the systemic circulation. The resulting radiation absorbed dose was calculated using the MIRDOSE3 program and residence times obtained from dogs and amounted to 0.0056 mGy/MBq to the whole body and 4.56 mGy/MBq to the urinary bladder. The absorbed dose of 188Re-DTPA to the whole body was one-tenth of that of 188Re-perrhenate. A window-based program was developed to calculate the exposure time and the radiation dose absorbed as a function of the 188Re concentration and the arbitrary distance from the balloon to the surrounding tissues. We conclude that 188Re-DTPA is easy to prepare, safe to use and suitable for intra-balloon brachytherapy after coronary angioplasty.

Ultraviolet transmittance of the vistakon disposable contact lenses

With increasing scientific evidence demonstrating the harmful effects of ultraviolet (UV) radiation on different ocular tissues, contact lens manufacturers are incorporating UV blocking monomers into their contact lenses. This study evaluated the transmittance spectra of Vistakon's disposable soft contact lenses (1 Day Acuvue, Acuvue, Surevue, and Vistavue). All except Vistavue contain a UV blocking agent. Transmittance for each lens was recorded from 200 to 400 nm on a Shimadzu UV 160U Dual Beam Recording Spectrophotometer. The results indicate that lenses which incorporate the UV blocking monomer significantly reduced the transmission of W radiation while untreated lenses did not. Our findings indicate that 1 Day Acuvue, Surevue, and Acuvue meet the American National Standards Institution (ANSI) Standard Z80.20 for Class 2 UV blockers: a maximum of 30% transmittance of UVA wavelengths and 5% transmittance of UVB wavelengths. In contrast, the Vistavue lens demonstrated negligible UV blockage. Our technique, in which contact lenses were placed directly in front of a measuring beam, was accurate and simpler than previously reported methods and may be useful in future studies. We found that UV blocking soft contact lenses can be a viable alternative for spectacles in protecting internal ocular structures from UV radiation. However, the external structures of the eye remain at risk and would continue to benefit from the use of UV blocking sunglasses or spectacle lenses.

Usefulness of 99Tcm-MDP knee SPET for pre-arthroscopic evaluation of patients with internal derangements of the knee

The aim of this study was to ascertain whether knee SPET can localize lesion sites in patients with internal derangements of the knee. We performed knee SPET as a pre-arthroscopic examination in 63 consecutive patients. SPET imaging was performed with a triple-headed SPET camera 4 h after the injection of 99Tcm-methylene diphosphonate. Arthroscopic diagnoses were as follows: 28 medial meniscus injuries, 24 lateral meniscus injuries, 31 anterior cruciate ligament (ACL) injuries, three posterior cruciate ligament injuries and one medial collateral ligament injury. Of 30 patients with crescent-shaped increased activity at the medial tibial plateau, 22 had medial meniscus injuries (positive predictive value: PPV 73%); of 17 patients with crescent-shaped activity at the lateral tibial plateau, 13 had lateral meniscus injuries (PPV 76%). Of 18 patients with increased activity at ACL attachment sites (primary sign), 17 had ACL injuries (PPV 94%). Of 27 patients with increased activity at bone impaction sites of ACL injury (secondary sign), 22 had ACL injuries (PPV 81%). Of 32 patients who had either a primary or secondary sign, 26 had ACL injuries (PPV 81%). We conclude that knee SPET is very useful in the management of internal derangements of the knee, particularly in determining the need for arthroscopy by localizing lesion sites.

Transient prolonged stunning induced by dipyridamole and shown on 1- and 24-hour poststress 99mTc-MIBI gated SPECT

We investigated whether poststress gated SPECT, which was believed to show resting wall motion, revealed stunning induced by dipyridamole stress.

METHODS

In 62 patients with coronary artery disease (n = 57) or chest pain (n = 5), dipyridamole stress gated 99mTc-hexakis-2-methoxyisobutyl isonitrile (MIBI) SPECT and rest 201Tl SPECT were performed on the first day; 24-h delayed 201Tl SPECT and rest gated 99mTc-MIBI SPECT were performed on the second day. Stress and rest gated 99mTc-MIBI SPECT was performed 1 h after injection. The myocardium was divided into 17 segments, and perfusion was scored on a 4-point scoring system (scores, 0-3 for normal to defect); wall motion during first-day poststress gated and second-day rest gated SPECT was also scored on another 4-point scale (scores, 0-3 for normal to dyskinesia).

RESULTS

Thirty-one of 62 patients showed wall motion abnormality that was worse after stress than during resting. Three hundred eight (29%) of the total 1054 segments showed wall motion abnormality on poststress gated SPECT. In 198 of these segments, wall motion abnormality was the same on poststress and rest gated SPECT, and 106 segments showed wall motion that was worse on 1-h poststress than on rest gated SPECT. Perfusion was normal either during rest (n = 113) or after a 24-h delay (n = 18) in 131 segments with the poststress wall motion abnormality. Of these 131 segments, 69 showed the same wall motion abnormality between poststress and resting periods (persistent stunning). However, in 40 segments, abnormal wall motion on 1-h poststress gated SPECT normalized on rest gated SPECT (transient prolonged stunning). The other 20 segments showed improvement of wall motion during rest compared with the poststress period but still showed abnormal wall motion during the resting period (between transient prolonged stunning and persistent stunning). Stress perfusion decrease was more severe in transient prolonged stunning than in persistent stunning. Poststress wall motion abnormality was more severe in persistent stunning.

CONCLUSION

Using gated 99mTc-MIBI SPECT, stunned myocardium was found on 1-h poststress SPECT compared with normal resting wall motion found on rest gated SPECT on the next day. We conclude that some myocardial walls did not show true resting wall motion on 1-h poststress gated SPECT; hence, caution is necessary when using wall motion on 1-h poststress gated SPECT to assess resting wall motion.

Interpretation of Wada memory test for lateralization of seizure focus by use of (99m)technetium-HMPAO SPECT

PURPOSE

Although the intracarotid amobarbital procedure (IAP) or Wada test is useful in lateralizing seizure focus in patients with temporal lobe epilepsy (TLE), the results of the IAP memory test are frequently nonlateralizing. An insufficient suppression of the medial temporal region contralateral to the seizure focus may contribute to the failure of lateralization. We tried to correlate IAP memory results with the functional changes in the contralateral medial temporal region as measured by single photon emission computed tomography (SPECT) during IAP.

METHODS

We performed a (99m)technetium-(Tc) hexamethylene-propylene-amine-oxime (HMPAO) brain SPECT in 19 medial TLE patients during a contralateral IAP (sodium amobarbital injected contralateral to the seizure focus). Regional cerebral blood flow (rCBF) was measured in the contralateral medial temporal region. The amount of decrease in the rCBF was calculated by subtracting the previous measurement from the one obtained with the interictal SPECT.

RESULTS

Ten (53%) patients passed and nine (47%) failed the contralateral IAP. The mean percentage decrease in rCBF was 5.3+/-5.3%. There was a significant negative correlation between a decrease in the rCBF and the IAP memory-retention score by Spearman correlation (p = -0.53: p<0.021). Patients with smaller decreases in rCBF (<5%) more frequently passed the contralateral IAP memory test than did those with larger decreases (80 vs. 22%; p<0.023).

CONCLUSIONS

We suggest that an insufficient suppression of the contralateral medial temporal function is partly responsible for nonlateralizing IAP memory tests. An IAP-SPECT may be useful in interpreting IAP memory tests for the lateralization of seizure focus in TLE patients.

Antibacterial activities of cryptotanshinone and dihydrotanshinone I from a medicinal herb, Salvia miltiorrhiza Bunge

Cryptotanshinone and dihydrotanshinone I, constituents of a medicinal plant, Salvia miltiorrhiza Bunge, had antibacterial activity against a broad range of Gram positive bacteria. These compounds generated superoxide radicals in Bacillus subtilis lysates. A recombination-deficient mutant strain of B. subtilis was 2- to 8-fold more sensitive than a wild strain, and this hypersensitivity was reduced in the presence of dithiothreitol as an antioxidant. DNA, RNA, and protein syntheses in B. subtilis were non-selectively inhibited by these compounds. These results suggest that superoxide radicals are important in the antibacterial actions of the agents.

Comparison of localizing values of various diagnostic tests in non-lesional medial temporal lobe epilepsy

Though the surgical treatment for medial temporal lobe epilepsy yields a high success rate, more studies are needed in order to determine the most efficacious pre-operative algorithm. The authors studied the relationship between surgical outcome and the localization results of various pre-operative diagnostic tests to assess the predictive value. Seventy-one consecutive patients who had undergone anterior temporal lobectomy with amygdalohippocampectomy with the diagnosis of non-lesional medial temporal lobe epilepsy, who had been followed up more than 24 months, were analyzed retrospectively. Electroencephalogy (EEG), magnetic resonance imaging (MRI), proton emission tomography (PET), single photon emission computed tomography (SPECT), the Wada test, and neuropsychological testing were analyzed. There was no diagnostic test that was found to have a statistically significant relationship between Engel Class I outcome and localization results (P & 0.05). SPECT, neuropsychological testing, and the Wada test all had less predictive values (P < 0.01). EEG and PET had comparable predictive values for Engel Class I with MRI (P & 0.05). No single diagnostic test alone is sufficient to make a diagnosis of non-lesional medial temporal lobe epilepsy. MRI, EEG and PET had comparable predictive values for Engel Class I. SPECT, neuropsychological testing, and the Wada test had less predictive values.

Emulsifying properties of acidic subunits of soy 11S globulin

The emulsifying properties of the acidic subunits (AS11S) isolated from soy glycinin (11S) have been studied. The isolated AS11S existed in solution mainly as a dimer species. Circular dichroic analysis indicated only a slight increase in aperiodic structure and no significant difference in beta-sheet structure when compared with those of soy 11S. At similar experimental conditions, the emulsifying properties of AS11S were superior to those of soy 11S and heat-denatured 11S. Emulsions prepared with 1% AS11S remained very stable without any visible oil separation for more than a month under gentle agitating conditions, whereas those prepared with 1% 11S collapsed and separated into phases within 2-3 days. The AS11S-stabilized emulsions were very stable below 0.15 M ionic strength. Studies on the rate of adsorption and surface tension reduction at the air-water interface showed that AS11S was significantly more surface active than soy 11S. It is proposed that, because the mass fraction of acidic subunits in soy 11S is approximately 60% and it is relatively easy to separate the acidic subunits from soy 11S, it may be industrially feasible to develop an economical process to isolate functional acidic subunits for use in emulsion-based food products.

Development of a method for measuring myocardial contractility with gated myocardial SPECT and arterial tonometry

BACKGROUND

Gated myocardial single photon emission computed tomography (SPECT) and radial artery applanation tonometry were used, respectively, to quantify the time-volume curve of the left ventricle and to estimate ventricular pressure wave. We developed ways of determining end-systolic elastance (Ees) with the normalized-single-beat method and tested the reproducibility of these measurements.

METHODS AND RESULTS

In patients with coronary artery disease (male/female = 33:2, age 66 +/- 10 years, ejection fraction 22% to 77%), rest thallium-201 gated/poststress technetium-99m sestamibi gated SPECT/24-hour rest Tc-99m sestamibi gated SPECT and arterial tonometry were performed. Quantitative gated SPECT software yielded a systolic time-volume curve, and tonometrically measured radial artery pressure wave yielded central aortic pressure wave. With systolic half of pressure-volume curve, void volume (Vo) was estimated and Ees was calculated. Over 71 measurements Ees ranged from 1.7 to 5.3 and Vo from -4 to 200 mL. Ejection duration, other indexes of central pressure waveform, end-diastolic volume, end-systolic volume, and ejection fraction were reproducible. The reproducibility of Vo was excellent (r = 0.97). Ees at rest (n = 15) showed fair reproducibility between Tc-99m-sestamibi and TI-201 SPECT (r = 0.51).

CONCLUSION

With gated myocardial SPECT, a noninvasive method of quantifying myocardial global contractility was developed. Reproducibility of this measurement was sufficient for use in clinical routine. Ees measured by this method warrants validation by invasively measured Ees.

Neural network modeling for on-line estimation of nutrient dynamics in a sequentially-operated batch reactor

In monitoring and controlling wastewater treatment processes, on-line information of nutrient dynamics is very important. However, these variables are determined with a significant time delay. Although the final effluent quality can be analyzed after this delay, it is often too late to make proper adjustments. In this paper, a neural network approach, a software sensor, was proposed to overcome this problem. Software sensor refers to a modeling approach inferring hard-to-measure process variables from other on-line measurable process variables. A bench-scale sequentially-operated batch reactor (SBR) used for advanced wastewater treatment (BOD plus nutrient removal) was employed to develop the neural network model. In order to improve the network performance, the structure of neural network was arranged in such a way of reflecting the change of operational conditions within a cycle. Real-time estimation of PO3-(4), NO-3, and NH+4 concentrations was successfully carried out with the on-line information of the SBR system only.

Altered contractile response of penis under hypoxia with metabolic acidosis

Previous studies concerning ischemic priapism revealed that hypoxia alters the erectile and contractile responses of penis. But the effects of accompanying acidosis on those responses have not been fully evaluated or understood yet. We performed this study to elucidate the role of acidosis on the trabecular smooth muscle contractility like in ischemic priapism. Under the general anesthesia, 55 mature male cats were conditioned to systemic metabolic acidosis by hypoventilation by animal ventilator. The changes of intracavernous pressure (ICP) to erectogenic agents (acetylcholine, L-arginine, prostaglandin E1: PGE1), erectolytic agents (epinephrine, thromboxane A2; TXA2), K channel-related drugs (pinacidil, 4-aminopyridine, tetraethylammonium; TEA, glibenclamide) and calcium ionophore were monitored at Set 1 (PO2 > 60 mmHg, pH > 7.25), Set 2 (PO2 < 30 mmHg, 7.25 > pH > 7.0), Set 3 (PO2 < 30 mmHg, pH < 7.0), and Set 4 (PO2 > 60 mmHg, pH < 7.0) in vivo. At Set 1 and Set 2, epinephrine, TXA2, and ionomycin decreased the ICP by acetylcholine or PGE1 (n = 9, P < 0.01). The decrease of ICP was in order of epinephrine, TXA2 and ionomycin. Acidosis reduced the increase of ICP to acetylcholine or PGE1 (n = 8, P < 0.01), TXA2 or ionomycin did not affect ICP under severe acidosis but epinephrine decreased ICP even under severe acidosis (n = 7, P < 0.05). Pretreatment of potassium channel blockers did not suppress the increase of ICP by erectogenic agents under acidosis (n = 6, P < 0.05). Pinacidil did not affect ICP under acidosis (n = 6, P < 0.01). These results suggest that acidosis impairs the contractile response of cavernous smooth muscle to erectolytic agents. It may be the results of the interference by [H+] with the intra and extracellular mechanisms that regulate the homeostasis of [Ca2]. Conclusively, besides hypoxia, acidosis is another limiting factor of trabecular smooth muscle contractility like in ischemic priapism.

The effect of tumor size on F-18-labeled fluorodeoxyglucose and fluoroerythronitroimidazole uptake in a murine sarcoma model

The purpose of this study was to evaluate the effect of tumor size on the uptake of 18F-fluorodeoxyglucose (FDG) and fluoroerythronitroimidazole (FETNIM) in a murine sarcoma model. ICR mice were xenografted with sarcoma 180 cell line and tumors were allowed to grow to a weight of 0.26-5.82 grams. 18F-FDG and 18F-FETNIM were injected intravenously in separate groups of mice, and after 1 hr, the tumors were excised and radiotracer uptake was measured. In another group of mice tumors were autoradiographically analyzed and subjected to H & E staining. In both the FDG and FETNIM group, per-gram radiotracer uptake by a tumor was inversely proportional to tumor weight. 18F-FETNIM correlated more (r = -0.593, p < 0.05) than 18F-FDG (r = -0.447, p < 0.05). Autoradiographic studies revealed that FDG accumulated in viable tumor areas, whereas FETNIM accumulated in both viable and partially necrotic areas. In the case of 18F-FETNIM, a direct correlation between tumor weight and the no-uptake-area to total-tumor-area was demonstrated. We concluded that increased tumor size is associated with decreased uptake of 18F-FDG and FETNIM, though this depends on the type of radiotracers and distribution of necrosis.

Detection of cancer in augmented breasts by positron emission tomography

OBJECTIVE

To assess the diagnostic efficiency of positron emission tomography with 18-fluorine fluorodeoxyglucose in detecting breast cancer in augmented breasts.

DESIGN

Retrospective study.

SETTING

University hospital, Korea.

SUBJECT

9 cases or 8 patients with breasts augmented with paraffin or silicone.

INTERVENTION

FDG-PET, mammography, and ultrasonography

RESULTS

The mammogram detected the breast cancer in only 1 of 3 patients, and ultrasonography gave a false positive result in 1 patient with an augmented breast. In contrast, PET predicted all the cancers and 5/6 benign lesions. 2/3 breast cancers had axillary FDG uptake interpreted as showing metastatic involvement, and in 1 case with cancer with no axillary lymph node involvement there was no FDG uptake in the axilla, which correlated with the pathological finding.

CONCLUSIONS

Although the high cost of PET makes its use as a screening test for all patients with augmented breasts unrealistic, it would be the best diagnostic choice if other methods failed.

No further development of renal scarring after antireflux surgery in children with primary vesicoureteral reflux: review of the results of 99mtechnetium dimercapto-succinic acid renal scan

PURPOSE

Reports of previous studies using excretory urography indicate that significant numbers of new scars developed in 5 to 31% of cases and scarring progressed in 11 to 16% after antireflux surgery. We evaluated renal scarring after surgery using a more accurate method, that is dimercapto-succinic acid renal scintigraphy.

MATERIALS AND METHODS

Between 1985 and 1997 antireflux surgery was performed for primary vesicoureteral reflux in 223 children at our hospital. Of these patients 45 boys and 29 girls with a median age of 74 months at surgery in whom preoperative and postoperative renal scans were available form the basis of our retrospective study. Renal scan was performed 0.3 to 58 months (median 2) preoperatively and 5.3 to 44 months (median 18.7) postoperatively. A total of 24 children (39 renal units) were followed further by additional scanning for as long as 25 to 120 months (median 43.2) postoperatively. Each scan was blindly reviewed for the size, number and zone location of cortical defects based on morphology. Interval changes were grouped into categories as improved, no change, progressed and new scar formation.

RESULTS

Postoperatively there was no ureteral obstruction. Pyelonephritis developed in 2 patients (2.7%) and asymptomatic bacteriuria was noted in 35 (47.3%) postoperatively. Of the renal units 110 (86.6%) showed no change, while 15 (11.8%) were improved and 2 (1.6%) had progression. In no case was new renal scar formation observed.

CONCLUSIONS

Contrary to most previous reports involving excretory urography, our results indicate no significant progression of renal scarring after antireflux surgery. In most cases postoperative followup renal scans demonstrated no significant morphological change. When there was change, it mostly involved the disappearance or decrease of renal scars.

A survey of helminthic infections in the residents of rural areas near Ulaanbaatar, Mongolia

A total of 738 samples was collected to survey the helminthic infections of residents in two rural areas near Ulaanbaatar, Mongolia for 2 weeks from July 23 to August 2, 1998. Among 391 scotch-taped slides of anal swabs of children and of young teenagers. Enterobius vermicularis eggs were detected in 138 cases (35.3%). With the fecal samples of 206 Kato-Katz thick smear slides from adults, the eggs of E. vermicularis were observed in 9 cases and Taenia sp. in one case, respectively. And by ELISA on 141 blood samples absorbed to blood sampling paper, 12 cases (8.5%) were found to be positive against the hydatid cyst antigen. Enterobiasis and hydatidosis are two major endemic diseases which are related closely to the life style of Mongolian.

No further development of renal scarring after antireflux surgery in children with primary vesicoureteral reflux: review of the results of 99mtechnetium dimercapto-succinic acid renal scan

PURPOSE

Reports of previous studies using excretory urography indicate that significant numbers of new scars developed in 5 to 31% of cases and scarring progressed in 11 to 16% after antireflux surgery. We evaluated renal scarring after surgery using a more accurate method, that is dimercapto-succinic acid renal scintigraphy.

MATERIALS AND METHODS

Between 1985 and 1997 antireflux surgery was performed for primary vesicoureteral reflux in 223 children at our hospital. Of these patients 45 boys and 29 girls with a median age of 74 months at surgery in whom preoperative and postoperative renal scans were available form the basis of our retrospective study. Renal scan was performed 0.3 to 58 months (median 2) preoperatively and 5.3 to 44 months (median 18.7) postoperatively. A total of 24 children (39 renal units) were followed further by additional scanning for as long as 25 to 120 months (median 43.2) postoperatively. Each scan was blindly reviewed for the size, number and zone location of cortical defects based on morphology. Interval changes were grouped into categories as improved, no change, progressed and new scar formation.

RESULTS

Postoperatively there was no ureteral obstruction. Pyelonephritis developed in 2 patients (2.7%) and asymptomatic bacteriuria was noted in 35 (47.3%) postoperatively. Of the renal units 110 (86.6%) showed no change, while 15 (11.8%) were improved and 2 (1.6%) had progression. In no case was new renal scar formation observed.

CONCLUSIONS

Contrary to most previous reports involving excretory urography, our results indicate no significant progression of renal scarring after antireflux surgery. In most cases postoperative followup renal scans demonstrated no significant morphological change. When there was change, it mostly involved the disappearance or decrease of renal scars.

The peptide ligands mediating positive selection in the thymus control T cell survival and homeostatic proliferation in the periphery

Positive selection to self-MHC/peptide complexes has long been viewed as a device for skewing the T cell repertoire toward recognition of foreign peptides presented by self-MHC molecules. Here, we provide evidence for an alternative possibility, namely, that the self-peptides controlling positive selection in the thymus serve to maintain the longevity of mature T cells in the periphery. Surprisingly, when total T cell numbers are reduced, these self-ligands become overtly stimulatory and cause naive T cells to proliferate and undergo homeostatic expansion.

Brain metastasis after immunotherapy in patients with metastatic melanoma or renal cell cancer: is craniotomy indicated?

The purpose of this study was to evaluate the outcome of surgical treatment of brain metastasis in patients with metastatic melanoma or renal cell cancer after interleukin-2 (IL-2) therapy. A retrospective analysis was conducted at the Surgery Branch, National Cancer Institute. All patients with a diagnosis of metastatic melanoma or renal cell cancer who received IL-2 from January 1, 1985 to January 1, 1996 (n = 1385) were screened for the development of brain metastasis. Forty patients underwent surgical treatment of brain metastasis that developed after initiating IL-2 therapy. Thirty-six were rendered free of disease after resection of a single metastasis and were the focus of this study. Twenty-two of the 36 patients achieved a clinical response (10 complete responses and 12 partial responses) at extracranial sites of disease after IL-2-based immunotherapy and before the development of brain metastasis. The median disease-free interval in the brain after resection of a single metastasis was 21, 7, and 3 months for patients achieving a complete response, partial response, and no response (CR, PR, and NR) to IL-2 therapy, respectively. The median survival after craniotomy for these three groups of patients was 23, 17, and 7 months, respectively. The disease-free interval in the brain and the overall survival after craniotomy were significantly longer for patients achieving a CR to previous immunotherapy when compared with patients achieving a PR or NR. Of the 10 patients who had achieved a prior CR, 8 remained disease free in the brain at last follow-up, 6 remained alive beyond 1 year, and 3 > 4 years. Twenty-five patients experienced neurologic symptoms before craniotomy and all had complete resolution of their symptoms after surgery. Surgical treatment of single brain metastasis in patients with metastatic melanoma or renal cell cancer is indicated in carefully selected patients. The benefits of resection include palliation of symptoms and the potential for a prolonged disease-free interval in the brain.

Detection of epileptiform activities in the EEG using neural network and expert system

This paper proposes a multichannel spike detection in long term EEG monitoring for epilepsy. It is achieved by wavelet transform(WT), artificial neural network(ANN) and the expert system. First, a small set of wavelet coefficients is used to represent the characteristics of a single channel epileptic spikes and normal activities. The purpose of this WT is to reduce the number of inputs to the ANN. Next, three layer feed-forward network employing the error back propagation algorithm is trained and tested using parameters obtained by the WT. Spikes are identified in individual EEG channels by 16 identical neural networks. Finally, 16-channel expert system based on the context information of adjacent channels is introduced to reject artifacts and produce reliable results. In this study, epileptic spikes and normal activities were selected from 32 patient's EEGs (the seizure disorder: 12, normal: 20) in consensus among experts. The result shows that the WT reduced data input size and the preprocessed ANN had 97% sensitivity and 89.5% selectivity, which were more accurate than that of ANN with the same input size of raw data. In clinical result, our expert rule system, which uses neighboring channel informations, was capable of rejecting artifacts commonly found in EEG recordings.

Four cases of therapy-related leukemia

Combination chemotherapy and radiation therapy have contributed to the successful treatment of various cancer patients. But the development of second malignancies is an inevitable complication of long-term cytotoxic treatment. The most serious and frequent of such complications is acute myelogenous leukemia (AML). Therapy-related leukemia is generally fatal. Since the number of patients exposed to chemotherapy is increasing each year, the clinical significance of this entity cannot be underestimated. There have been many investigations of therapy-related leukemia, but in Korea published reports are rare. We describe four such cases, involving one older female with lung cancer and three children with acute lymphoblastic leukemia (ALL) and malignant lymphoma. Alkylating agents were used for chemotherapy, and in one case, topoisomerase II inhibitor. Irrespective of the causative agents, the latency periods were relatively short, and despite induction chemotherapy in two, all survived for only a few months. During the follow-up of patients treated for primary malignancies, the possibility of therapy-related leukemia should always be borne in mind.

Value of FDG PET in papillary thyroid carcinoma with negative 131I whole-body scan

The management of metastatic thyroid carcinoma patients with a negative 131I scan presents considerable problems. Fifty-four athyrotic papillary thyroid carcinoma patients whose 1311 whole-body scans were negative underwent 18F-fluorodeoxyglucose (FDG) PET; the purpose was to determine whether this procedure could localize metastatic sites. We also assessed its usefulness in the management of these patients.

METHODS

Whole-body emission scan was performed 60 min after the injection of 370-555 MBq 18F-FDG, and additional regional attenuation-corrected scans were obtained. Metastasis was pathologically confirmed in 12 patients and was confirmed in other patients by overall clinical evaluation of the findings of other imaging studies and of the subsequent clinical course.

RESULTS

In 33 patients, tumor had metastasized, whereas 21 patients were in remission. FDG PET revealed metastases in 31 patients (sensitivity 93.9%), whereas thyroglobulin levels were elevated in 18 patients (sensitivity 54.5%). FDG PET was positive in 14 of 15 metastatic cancer patients with normal thyroglobulin levels. In 20 of 21 patients in remission, FDG PET was negative (specificity 95.2%), whereas thyroglobulin levels were normal in 16 patients (specificity 76.1%). The sensitivity and specificity of FDG PET were significantly higher than those of serum thyroglobulin. In patients with negative 1311 scans, FDG PET detected cervical lymph node metastasis in 87.9%, lung metastasis in 27.3%, mediastinal metastasis in 33.3% and bone metastasis in 9.1%. In contrast, among 117 patients with 131I scan-positive functional metastases, 131I scan detected cervical lymph node metastasis in 61.5%, lung metastasis in 56.4%, mediastinal metastasis in 22.2% and bone metastasis in 16.2%. In all 5 patients in whom thyroglobulin was false-negative with negative antithyroglobulin antibody, PET showed increased 18F-FDG uptake in cervical lymph nodes, mediastinal lymph nodes, or both. Among patients with increased 18F-FDG uptake only in the cervical lymph nodes, the nodes were dissected in 11. Metastasis was confirmed in all, even in normal-sized lymph nodes.

CONCLUSION

FDG PET scan localized metastatic sites in 131I scan-negative thyroid carcinoma patients with high accuracy. In particular, it was superior to 131I whole-body scan and serum thyroglobulin measurement for detecting metastases to cervical lymph nodes. FDG PET was helpful for determining the surgical management of these patients.

Large deviation function of the partially asymmetric exclusion process

The large deviation function obtained recently by Derrida and Lebowitz [Phys. Rev. Lett. 80, 209 (1998)] for the totally asymmetric exclusion process is generalized to the partially asymmetric case in the scaling limit. The asymmetry parameter rescales the scaling variable in a simple way. The finite-size corrections to the universal scaling function and the universal cumulant ratio are also obtained to the leading order.