A comparative dosimetric study on tangential photon beams, intensity-modulated radiation therapy (IMRT) and modulated electron radiotherapy (MERT) for breast cancer treatment

Recently, energy- and intensity-modulated electron radiotherapy (MERT) has garnered a growing interest for the treatment of superficial targets. In this work. we carried out a comparative dosimetry study to evaluate MERT, photon beam intensity-modulated radiation therapy (IMRT) and conventional tangential photon beams for the treatment of breast cancer. A Monte Carlo based treatment planning system has been investigated, which consists of a set of software tools to perform accurate dose calculation, treatment optimization, leaf sequencing and plan analysis. We have compared breast treatment plans generated using this home-grown treatment optimization and dose calculation software forthese treatment techniques. The MERT plans were planned with up to two gantry angles and four nominal energies (6, 9, 12 and 16 MeV). The tangential photon treatment plans were planned with 6 MV wedged photon beams. The IMRT plans were planned using both multiple-gantry 6 MV photon beams or two 6 MV tangential beams. Our results show that tangential IMRT can reduce the dose to the lung, heart and contralateral breast compared to conventional tangential wedged beams (up to 50% reduction in high dose volume or 5 Gy in the maximum dose). MERT can reduce the maximum dose to the lung by up to 20 Gy and to the heart by up to 35 Gy compared to conventional tangential wedged beams. Multiple beam angle IMRT can significantly reduce the maximum dose to the lung and heart (up to 20 Gy) but it induces low and medium doses to a large volume of normal tissues including lung, heart and contralateral breast. It is concluded that MERT has superior capabilities to achieve dose conformity both laterally and in the depth direction, which will be well suited for treating superficial targets such as breast cancer.

Brain glucose metabolic changes associated with neuropsychological improvements after 4 months of treatment in patients with obsessive-compulsive disorder

OBJECTIVE

The study was designed to elucidate regional brain metabolic changes according to a treatment and their relationship with neuropsychological performance changes in obsessive-compulsive disorder (OCD).

METHOD

Cerebral glucose metabolic rates were repeatedly measured before and after treatment in 10 patients with OCD using [18F]-2-fluoro-deoxyglucose positron emission tomography (PET). They were compared on a voxel-basis, and the correlations were counted between the regional metabolic changes and the degree to improvement on the neuropsychological assessments.

RESULTS

After treatment, the patients showed significant (P < 0.005, two-tailed) regional metabolic changes in multiple brain areas involving frontal-subcortical circuits and parietal-cerebellar networks. Especially, the metabolic changes of the putamen, the cerebellum, and the hippocampus were significantly correlated with the improvement of the immediate- and delayed-recall scores of the Rey-Osterrieth Complex Figure Test (RCFT).

CONCLUSION

These results suggest a possibility that metabolic changes of frontal-subcortical and parietal-cerebellar circuit changes may underlie cognitive improvements in patients with OCD.

Determination of the prognostic value of [(18)F]fluorodeoxyglucose uptake by using positron emission tomography in patients with non-small cell lung cancer

The aim of this study was to determine whether quantitative information obtained from [(18)F]fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) has a prognostic significance for patients with non-small cell lung cancer (NSCLC). We investigated (18)F-FDG PET imaging of 73 patients with NSCLC. The maximum standardized uptake value (SUV(max)) was significantly different between the histopathological types of tumour (squamous cell carcinoma (n=37, 12.4+/-5.1), adenocarcinoma (n=30, 8.2+/-5.8), bronchioloalveolar carcinoma (n=4, 2.6+/-1.7), <0.01). In the univariate analysis of all patients, staging (P=0.0001), tumour cell type (P=0.013), and a SUV(max) greater than 7 (P=0.0011) was correlated with survival. However, a multivariate analysis identified staging and SUV(max) greater than 7 were affected survival adversely. The mortality rate of patients with group I disease (stage I to stage IIIA) was 5.8 times lower than that of patients with group II disease (stage IIIB to stage IV). Patients with a high SUV(max) (> or =7) had a 6.3 times higher mortality than those with a low SUV(max)(<7). By multivariate analysis of patients with squamous cell carcinoma, only grouping affected survival (P=0.008, relative risk=4.3). In the case of adenocarcinoma, the SUV(max) (>10) correlated exclusively with poorer survival (P=0.031, relative risk=11.152). (18)F-FDG uptake correlated with survival in NSCLC. Especially in adenocarcinomas, the SUV(max) was complementary to other known prognostic factors.

Clinical significance of elevated level of serum antithyroglobulin antibody in patients with differentiated thyroid cancer after thyroid ablation

OBJECTIVE

This study was designed to investigate whether an elevated serum antithyroglobulin antibody (TgAb) reflects cancer recurrence in thyroglobulin (Tg)-undetectable patients with differentiated thyroid carcinoma (DTC) after thyroid ablation.

DESIGN

We measured serum TgAb level and evaluated the disease status in 226 DTC patients who had undergone remnant ablation and showed an undetectable Tg result as assessed by immunoradiometric assay.

MEASUREMENTS

Radioligand assay of TgAb was performed. Recurrence was assessed by 131I scan, 18F-fluorodeoxyglucose positron emission tomography, sonography, computed tomography, or by surgical operation.

RESULTS

Fifty-one patients (22.6%) of the Tg-undetectable patients showed positive TgAb, and 25 (49.0%) of these were confirmed with recurrence. The recurrence rate of TgAb-positive patients was higher than that of TgAb-negative patients (3.4%; P < 0.0001). During follow-up, 73.1% of the disease-free patients showed spontaneously decreased TgAb levels. A total of 71.4% of patients with recurrent cancer, who showed responses to surgical operation or radio-iodine treatment, also showed a decreased TgAb level.

CONCLUSIONS

Persistently elevated TgAb levels appear to serve as a useful marker for recurrent or persistent DTC in patients with undetectable serum Tg results. Thus, the routine measurement of TgAb in such patient populations may be indicated.

A Monte Carlo dose calculation tool for radiotherapy treatment planning

A Monte Carlo user code, MCDOSE, has been developed for radiotherapy treatment planning (RTP) dose calculations. MCDOSE is designed as a dose calculation module suitable for adaptation to host RTP systems. MCDOSE can be used for both conventional photon/electron beam calculation and intensity modulated radiotherapy (IMRT) treatment planning. MCDOSE uses a multiple-source model to reconstruct the treatment beam phase space. Based on Monte Carlo simulated or measured beam data acquired during commissioning, source-model parameters are adjusted through an automated procedure. Beam modifiers such as jaws, physical and dynamic wedges, compensators, blocks, electron cut-outs and bolus are simulated by MCDOSE together with a 3D rectilinear patient geometry model built from CT data. Dose distributions calculated using MCDOSE agreed well with those calculated by the EGS4/DOSXYZ code using different beam set-ups and beam modifiers. Heterogeneity correction factors for layered-lung or layered-bone phantoms as calculated by both codes were consistent with measured data to within 1%. The effect of energy cut-offs for particle transport was investigated. Variance reduction techniques were implemented in MCDOSE to achieve a speedup factor of 10-30 compared to DOSXYZ.

Synthesis of 188 Re-labelled long chain alkyl diaminedithiol for therapy of liver cancer

Radioisotope-labelled lipiodol has been used in the therapy of liver cancer. Recently a lipiodol solution of 188Re-labelled diaminedithiol (DD) has been reported to show a high uptake in the liver cancer. We synthesized long-chain alkyl DD derivatives to improve their uptake and retention in tissue. As the length of the alkyl chain increased, tissue uptake and retention also increased due to hydrophobic interaction with lipiodol. Among the synthesized compounds, the lipiodol solution of 188Re-HDD, the DD derivative with the longest side chain (C16), is a promising agent for therapy of liver cancer.

Functional neuroimaging in epilepsy: FDG PET and ictal SPECT

Epileptogenic zones can be localized by F-18 fluorodeoxyglucose positron emission tomography (FDG PET) and ictal single-photon emission computed tomography(SPECT). In medial temporal lobe epilepsy, the diagnostic sensitivity of FDG PET or ictal SPECT is excellent, however, the sensitivity of MRI is so high that the incremental sensitivity by FDG PET or ictal SPECT has yet to be proven. When MRI findings are ambiguous or normal, or discordant with those of ictal EEG, FDG PET and ictal SPECT are helpful for localization without the need for invasive ictal EEG. In neocortical epilepsy, the sensitivities of FDG PET or ictal SPECT are fair. However, because almost a half of the patients are normal on MRI, FDG PET and ictal SPECT are helpful for localization or at least for lateralization in these non-lesional epilepsies in order to guide the subdural insertion of electrodes. Interpretation of FDG PET has been recently advanced by voxel-based analysis and automatic volume of interest analysis based on a population template. Both analytical methods confirmed the performance of previous visual interpretation results. Ictal SPECT was analyzed using subtraction methods(coregistered to MRI) and voxel-based analysis. Rapidity of injection of tracers, HMPAO versus ECD, and repeated ictal SPECT, which remain the technical issues of ictal SPECT, are detailed.

Diagnostic performance of [18F]FDG-PET and ictal [99mTc]-HMPAO SPECT in occipital lobe epilepsy

PURPOSE

We investigated whether interictal F-18 fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) or ictal [99mTc]-HMPAO single-photon emission computed tomography (SPECT) was useful to find epileptogenic zones in occipital lobe epilepsy (OLE).

METHODS

We reviewed visually and quantified patterns of hypometabolism in interictal [18F]FDG-PET and those of hyperperfusion in ictal SPECT in 17 OLE patients (27 plus minus 6.8 years old; M/F, 10/7; injection time, 30 plus minus 17 s). OLE was diagnosed based on invasive electroencephalography, surgery, and postsurgical outcome (Engel class I in all at an average of 26 months after surgery).

RESULTS

Epileptogenic zones were correctly localized in nine (60%) of 15 patients by interictal [18F]FDG-PET, and asymmetric indices corroborated visual diagnosis. Epileptogenic hemispheres were correctly lateralized in 14 (93%) of 15 patients on [18F]FDG-PET. Epileptogenic hemispheres were correctly lateralized in 13 (76%) of 17 patients using ictal SPECT, but localization was possible in only five (29%) patients. Interictal [18F]FDG-PET was helpful in two of the patients who showed no abnormality on magnetic resonance imaging (MRI) and no possible localization with ictal SPECT.

CONCLUSIONS

In OLE, ictal SPECT was helpful in lateralization, but less helpful in localization. Interictal [18F]FDG-PET was helpful in localization or lateralization of epileptogenic zones, even in patients with ambiguous MRI or ictal SPECT findings.

Antioxidant effect of melatonin in human retinal neuron cultures

This study investigates whether the neurohormone melatonin can prevent the retinal neuronal injury caused by reactive oxygen species (ROS) in cultured human retinal neuronal cells. Cultures of human retinal neuronal cells established from a variety of donors were grown to 14 days and then subjected to experimental hypoxanthine/xanthine oxidase (HX/XO)-induced injury. Intracellular production of ROS by administration of HX/XO was confirmed by flow cytometry; the ROS resulted in both apoptotic and necrotic pattern of cell death in the retinal neuron cultures. The efficacy of melatonin against ROS injury was quantitated by MTT assay, enzyme immunoassay, and immunocytochemistry for neurofilament protein. The antioxidative effect of melatonin was compared with that of alpha-tocopherol. Retinal neuronal injury significantly reduced in a dose-response manner by a treatment of 1.0-8.0 mM alpha-tocopherol. Melatonin, in concentrations of more than 2.0 mM, also significantly reduced the injury. About 70% of cells are rescued by pretreatment with 1.0 mM alpha-tocopherol and 8.0 mM melatonin in the MTT assay. Our observations suggest that melatonin can rescue retinal neurons from ROS injury in human retinal cell cultures.

Disparity of perfusion and glucose metabolism of epileptogenic zones in temporal lobe epilepsy demonstrated by SPM/SPAM analysis on 15O water PET, [18F]FDG-PET, and [99mTc]-HMPAO SPECT

PURPOSE

To elucidate uncoupling of perfusion and metabolism and its significance in epilepsy, 15O water and 18F fluorodeoxyglucose (FDG) positron emission tomography (PET) and Tc-99m hexamethyl-propyleneamine-oxime (HMPAO) single-photon emission computed tomography (SPECT) were examined by SPM (statistical parametric mapping) and quantitation by using SPAM (statistical probabilistic anatomic map).

METHODS

[15O]water and [18F]FDG-PET, and [99mTc]-HMPAO SPECT were performed in 25 patients (SPECT in 17 of 25) with medial temporal lobe epilepsy. For volume of interest (VOI) count analysis, the normalized counts using VOI based on SPAM templates of PET and SPECT were compared with those of the normal controls. Perfusion or metabolism was found abnormal if the Z score was >2 for each VOI. For SPM analysis, the differences between each patient's image and a group of normal control images (t statistic for p < 0.01) on a voxel-by-voxel basis were examined to find significant decreases in perfusion or metabolism.

RESULTS

With SPAM VOI count analysis, areas of hypoperfusion were found in 13 patients in the epileptogenic temporal lobes by [15O]water PET and areas of hypometabolism in 21 patients by [18F]FDG-PET. With voxel-based SPM analysis, the epileptogenic zones were localized in 15 by [15O]water PET and in 23 patients by [18F]FDG-PET. The localization by [15O]water PET was concordant with that of [18F]FDG-PET. The areas of hypoperfusion on [15O]water PET were absent or smaller than the areas of hypometabolism on [18F]FDG-PET. Interictal [99mTc]-HMPAO SPECT revealed the hypoperfused zones in seven of 17 patients on visual assessment.

CONCLUSIONS

SPAM VOI count and SPM analysis of [15O]water and [18F]FDG-PET and [99mTc]-HMPAO SPECT revealed that in the same patients, the areas of hypoperfusion were concordant with but smaller than the areas of hypometabolism. Discordance of perfusion and metabolic abnormalities represents an uncoupling of perfusion and metabolism in the epileptogenic zones, and this might explain the lower diagnostic accuracy of perfusion imaging in temporal lobe epilepsy.

Different patterns of lymphoscintigraphic findings in patients with intestinal lymphangiectasia

Technetium-99m antimony sulfide colloid lymphoscintigraphy conveniently demonstrates intestinal leakage of lymph in patients with intestinal lymphangiectasia. However, we found no intestinal radioactivity in some patients. We evaluated lymphoscintigraphic findings and compared them with clinical data. Technetium-99m antimony colloid lymphoscintigraphy was performed in 12 patients (age, 8.9+/-6.4 years; male:female=8:4) with histologically proven intestinal lymphangiectasia. After subcutaneous injection of 103.6 MBq of technetium-99m antimony colloid into the webs of both feet, sequential abdominal images were obtained up to 24 h post-injection. Four patients underwent technetium-99m methylene diphosphonate bone scintigraphy. Patients were divided into two groups according to the presence or absence of intestinal radioactivity. Five showed intestinal activity (Group 1), but seven did not (Group 2). No Group 1 patient had a history of ascites, while all Group 2 patients had ascites as the initial manifestation. Serum total protein and albumin levels were significantly lower in Group 1 patients than in Group 2 patients. In three Group 1 patients, technetium-99m methylene diphosphonate bone scintigraphy revealed intestinal radioactivity, while in one Group 2 patient this was not found. We observed two types of lymphoscintigraphic pattern in patients with intestinal lymphangiectasia. To clarify the exact pathophysiology, further study is required.

Diversity in death certification: a case vignette approach

Previous studies have revealed high rates of errors in death certification, but few have discussed the nature of these errors. To explore the diversity among physicians in death certification and its relationship with the complexity of the causal sequence of death, we asked 145 physicians attending a continuing medical education course to complete the cause-of-death section on dummy death certificates of four case vignettes. The difficulty in determining the causal sequence of death varied from relatively simple to complex. Variations in death certification were classified according to wording, diagnostic semantics, combinations of expressions, correctness of certification format, and concordance with the referent underlying cause of death (UCOD). Given the same case history information, physicians showed great variation in wording and diagnostic semantics in death certification. The rates of correct certification format and concordance with referent UCOD varied with the level of complexity of the causal sequence of death. The greatest source of diversity was choosing between an acute condition of a chronic disease and the chronic disease itself, and between competing prominent comorbidities. Experience in death certification was significantly associated with correct certification format but not with concordance with referent UCOD. Knowledge of death certification was not associated with correct certification format or concordance with referent UCOD. Our findings indicate that the traditional concept of UCOD tabulation and using a single standard ICD code in evaluating the quality of death certification oversimplifies a complex situation. Variations in death certification, especially the selection of UCOD, were due to differences in interpreting the information rather than differences in knowledge of death certification.

Sequence, transcriptional analysis and chromosomal location of the Xanthomonas campestris pv. campestris uvrB gene

The uvrB gene of Xanthomonas campestris pv. campestris, a Gram-negative plant pathogenic bacterium inhabiting soil and infected plants, was cloned and sequenced. This gene has the capacity to encode a polypeptide of 673 amino acid residues with a calculated molecular mass of 75.9 kDa. Its deduced amino acid sequence shows a high degree of similarity and possesses domain conservation to those of bacterial UvrB. The uvrB mutant, isolated by gene replacement, is extremely sensitive to ultraviolet irradiation. Like the situation in the X. campestris pv. campestris recA gene, no SOS box is present upstream of the uvrB gene. Northern blotting and transcriptional fusion assay with lacZ indicated that X. campestris pv. campestris uvrB is expressed constitutively at high levels and cannot be further induced by UV irradiation. These results suggest a regulatory mechanism different from that for the expression of Escherichia coli uvrB. Using a gene-tagging strategy in conjunction with pulsed-field gel electrophoresis, the uvrB gene was located near 1 o'clock on the X. campestris pv. campestris 17 chromosome (4.8 Mb) map, which is far apart from the lexA-recA-recX cluster near 5 o'clock.

Grey matter abnormalities in obsessive-compulsive disorder: statistical parametric mapping of segmented magnetic resonance images

BACKGROUND

Although a number of functional imaging studies are in agreement in suggesting orbitofrontal and subcortical hyperfunction in the pathophysiology of obsessive-compulsive disorder (OCD), the structural findings have been contradictory.

AIMS

To investigate grey matter abnormalities in patients with OCD by employing a novel voxel-based analysis of magnetic resonance images.

METHOD

Statistical parametric mapping was utilised to compare segmented grey matter images from 25 patients with OCD with those from 25 matched controls.

RESULTS

Increased regional grey matter density was found in multiple cortical areas, including the left orbitofrontal cortex, and in subcortical areas, including the thalamus. On the other hand, regions of reduction were confined to posterior parts of the brain, such as the left cuneus and the left cerebellum.

CONCLUSIONS

Increased grey matter density of frontal-subcortical circuits, consonant with the hypermetabolic findings from functional imaging studies, seems to exist in patients with OCD, and cerebellar dysfunction may be involved in the pathophysiology of OCD.

c-JUN expression and apoptotic cell death in kainate-induced temporal lobe epilepsy

Following kainate (KA)-induced epilepsy, rat hippocampal neurons strongly express immediate early gene (IEG) products, i.e., c-FOS and c-JUN, and neural stress protein, HSP72. Prolonged expression of c-JUN and c-FOS 48 hr after cerebral ischemia has been underwent delayed neuronal death. However, it is not yet clear whether IEGs actually assume the essential roles in the cell death process or simply as a by-product due to external stimuli because of the prolonged expression of c-FOS, more than one week, on intact CA2 neurons of the hippocampus in a KA-induced epilepsy model. This study investigated the relationships between prolonged expression of c-JUN and hippocampal neuronal apoptosis in a KA-induced epilepsy model. Epileptic seizure was induced in rats by a single microinjection of KA (1 microgram/microL) into the left amygdala. Characteristic seizures and hippocampal neuronal injury were developed. The expression of c-JUN was evaluated by immunohistochemistry, and neuronal apoptosis by in situ end labeling. The seizures were associated with c-JUN expression in the hippocampal neurons, of which the level showed a positive correlation with that of apoptosis. Losses of hippocampal neurons, especially in the CA3 region, were partly caused by apoptotic cell death via a c-JUN-mediated signaling pathway. This is thought to be an important component in the pathogenesis of hippocampal neuronal injury via KA-induced epilepsy.

Calcium/calmodulin kinase II activity of hippocampus in kainate-induced epilepsy

This study investigated calcium/calmodulin kinase II (CaMKII) activity related to long-standing neuronal injury of the hippocampus in kainate (KA)-induced experimental temporal lobe epilepsy. Epileptic seizure was induced by injection of KA (1 microg/microL) dissolved in phosphate buffer (0.1 M, pH 7.4) into the left amygdala. Clinical seizures, histopathologic changes and CaMKII activity of the hippocampus were evaluated. Characteristic early limbic and late seizures were developed. Hippocampal CaMKII activity increased significantly 4 and 8 weeks after intra-amygdaloid injection of KA, when late seizures developed. The histopathologic changes of the hippocampus included swelling of neuronal cytoplasm with nuclear pyknosis and loss of neurons in CA3 during this period. The increased activity of CaMKII may correlate with appearance of distant damage in the hippocampus. The above results indicate that intra-amygdaloid injection of KA produces excitatory signals for ipsilateral CA3 neurons in the hippocampus and that subsequently increased levels of CaMKII in postsynaptic neurons induce neuronal injury via phosphorylation of N-methyl-D-aspartate type glutamate receptor.

Prolonged morphine treatment targets delta opioid receptors to neuronal plasma membranes and enhances delta-mediated antinociception

Opioid receptors are known to undergo complex regulatory changes in response to ligand exposure. In the present study, we examined the effect of morphine on the in vitro and in vivo density and trafficking of delta opioid receptors (deltaORs). Prolonged exposure (48 hr) of cortical neurons in culture to morphine (10 microm) resulted in a robust increase in the internalization of Fluo-deltorphin, a highly selective fluorescent deltaOR agonist. This effect was mu-mediated because it was entirely blocked by the selective mu opioid receptor antagonist d-Phe-Cys-Tyr-d-Trp-Orn-Thr-Pen-Thr-NH(2) and was reproduced using the selective mu agonist fentanyl citrate. Immunogold electron microscopy revealed a marked increase in the cell surface density of deltaORs in neurons exposed to morphine, indicating that the increase in Fluo-deltorphin internalization was caused by increased receptor availability. Prolonged morphine exposure had no effect on deltaOR protein levels, as assessed by immunocytochemistry and Western blotting, suggesting that the increase in bioavailable deltaORs was caused by recruitment of reserve receptors from intracellular stores and not from receptor neosynthesis. Complementary in vivo studies demonstrated that chronic treatment of adult rats with morphine (5-15 mg/kg, s.c., every 12 hr) similarly augmented targeting of deltaORs to neuronal plasma membranes in the dorsal horn of the spinal cord. Furthermore, this treatment markedly potentiated intrathecal d-[Ala(2)]deltorphin II-induced antinociception. Taken together, these results demonstrate that prolonged stimulation of neurons with morphine markedly increases recruitment of intracellular deltaORs to the cell surface, both in vitro and in vivo. We propose that this type of receptor subtype cross-mobilization may widen the transduction repertoire of G-protein-coupled receptors and offer new therapeutic strategies.

Fas mediates apoptosis in steroid-induced myopathy of rats

Recently, apoptotic cell death has been reported in differentiated skeletal muscle, where apoptosis was generally assumed not to occur. To investigate whether apoptosis may contribute to the steroid-induced myopathy, rats treated with triamcinolone acetonide (TA) for 9 days were sacrificed for detecting apoptosis by in situ end-labelling (ISEL) and DNA electrophoresis in soleus muscles. Immunohistochemical stainings of Fas antigen and p53 protein were performed to examine whether apoptosis-related proteins were present in the myopathy. Muscle fibre necrosis and apoptotic myonuclei appeared in soleus muscles following administration of TA, while control muscles showed no evidences for apoptosis. Fas antigen was not detected in control muscles, but expressed in soleus muscles of steroid-induced myopathy. Some of the Fas antigen-expressing muscle fibres were positive for ISEL. p53 Protein was not detected in any muscle fibres. These findings indicate that TA can induce apoptosis in differentiated skeletal muscles, and Fas antigen might be partly related to apoptotic muscle death in steroid-induced myopathy.

Oral bacterial therapy promotes recovery from acute diarrhea in children

Lactobacilli in the intestines play an important role in developing natural defenses against both intestinal bacterial and viral infections. So a prospective clinical study was carried out at Cathay General Hospital to determine the effect of Lactobacillus acidophilus and Bifidobacterium infantis on the course of acute diarrhea in hospitalized children. Altogether 100 children between 6 and 60 months of age were collected and randomly allocated into 2 groups. Study group (n = 50) was given Infloran Berna, which contains 10(9) viable Lactobacillus acidophilus and 10(9) Bifidobacterium infantis, one capsule tid for 4 days and control group (n = 50) received parenteral rehydration only without any medication. Only 20 stool cultures in study group had positive culture results for Lactobacillus or Bifidobacterium. All children were evaluated for the degree of dehydration before rehydration. The clinical course of diarrhea was followed during the treatment period. Features on admission were similar between the study group and control group in age, duration of diarrhea at home, serum sodium & potassium and dehydration degree. The duration of diarrhea was defined as the time until the last appearance of watery stool. There was no difference between the study group and control group in the frequency of diarrhea stools on the day before admission (p > 0.05). However, the frequency of diarrhea for study group improved on the first and second day of hospitalization with statistical difference (p < 0.01). The duration of diarrhea during hospitalization in study group also decreased (3.1 vs. 3.6 days, p < 0.01). Oral bacterial therapy is an effective adjuvant therapy in rotavirus positive and negative children with diarrhea and can safely be administered during an episode of acute diarrhea.

Monte Carlo based treatment planning for modulated electron beam radiation therapy

A Monte Carlo based treatment planning system for modulated electron radiation therapy (MERT) is presented. This new variation of intensity modulated radiation therapy (IMRT) utilizes an electron multileaf collimator (eMLC) to deliver non-uniform intensity maps at several electron energies. In this way, conformal dose distributions are delivered to irregular targets located a few centimetres below the surface while sparing deeper-lying normal anatomy. Planning for MERT begins with Monte Carlo generation of electron beamlets. Electrons are transported with proper in-air scattering and the dose is tallied in the phantom for each beamlet. An optimized beamlet plan may be calculated using inverse-planning methods. Step-and-shoot leaf sequences are generated for the intensity maps and dose distributions recalculated using Monte Carlo simulations. Here, scatter and leakage from the leaves are properly accounted for by transporting electrons through the eMLC geometry. The weights for the segments of the plan are re-optimized with the leaf positions fixed and bremsstrahlung leakage and electron scatter doses included. This optimization gives the final optimized plan. It is shown that a significant portion of the calculation time is spent transporting particles in the leaves. However, this is necessary since optimizing segment weights based on a model in which leaf transport is ignored results in an improperly optimized plan with overdosing of target and critical structures. A method of rapidly calculating the bremsstrahlung contribution is presented and shown to be an efficient solution to this problem. A homogeneous model target and a 2D breast plan are presented. The potential use of this tool in clinical planning is discussed.

Mucocele-like tumor of the breast associated with ductal carcinoma in situ and mucinous carcinoma : a case report

Mucocele-like tumor (MLT) of the breast is a rare neoplasm. Although this lesion was considered benign when first described, the concept of a pathologic continuum with mucinous carcinoma was evident in subsequent reports. Only a few cases of MLT have been reported in Korea. We describe a case of MLT associated with ductal carcinoma in situ and mucinous carcinoma in a 34-yr-old female. Histological examination showed multiple mucus-filled cysts of varying size. Extravasated mucin was present in the surrounding stroma. The lining of the cysts in most areas were of flat or cuboidal epithelium and devoid of cellular atypia. The lining epithelium showed proliferative change ranging from atypical ductal hyperplasia to ductal carcinoma in situ, micropapillary type. A microscopic focus of mucinous carcinoma within MLT was also noted. None of the lesions exhibited epithelial reactivity for p53 protein. The patient is alive and well without evidence of disease 54 months after initial treatment. This case supports the concept that MLT encompasses a spectrum of pathologic lesions including benign tumor, atypical ductal hyperplasia, ductal carcinoma in situ, and mucinous carcinoma.

Apoptosis of skeletal muscle on steroid-induced myopathy in rats

Recently apoptotic cell death has been reported in differentiated skeletal muscle, where apoptosis was generally assumed not to occur. To investigate whether apoptosis may contribute to the steroid-induced myopathy, rats treated with triamcinolone acetonide (TA) for 9 days were sacrificed for detecting apoptosis by in situ end labeling (ISEL) and electron microscopy in the soleus muscles. Immunohistochemical stainings of Fas antigen and p53 protein were performed to examine whether apoptosis-related proteins were present in the myopathy. Muscle fiber necrosis and apoptotic myonuclei appeared in the soleus muscles following administration of TA, while control muscles showed no evidences for apoptosis. Fas antigen was not detected in control muscles, but expressed in the soleus muscles of steroid-induced myopathy. Some of the Fas antigen-expressing muscle fibers were positive for ISEL. p53 protein was not detected in any muscle fibers. These findings indicate that TA can induce apoptosis in differentiated skeletal muscles, and Fas antigen might be partly related to apoptotic muscle death in steroid-induced myopathy.

p53 mutation and epidermal growth factor receptor overexpression in glioblastoma

Recent molecular studies indicate two different genetic pathways leading to the development of glioblastoma; final progression of astrocytoma and de novo formation. To define the mutual relationships of cytogenetic changes in the pathogenesis of glioblastoma, molecular histopathologic alterations of p53 and epidermal growth factor receptor (EGFR) were evaluated by single stranded conformational polymorphion, reverse transcriptase-polymerase chain reaction and immunohistochemical stains in 15 primary and 21 secondary glioblastomas. Mutations in p53 gene and positive immunoreactivity to p53 protein (DO1) were more prevalent in secondary glioblastomas than in primary glioblastomas. A correlation between p53 mutations and p53 immunopositivities in glioblastomas was observed in 83.3% of the cases. All cases with positive p53 immunoreactivities showed p53 mutations; however, 13.9% of glioblastomas with p53 immuno-positivities lacked the relevant mutations. EGFR amplifications were detected in 73.3% of primary glioblastomas and 9.5% of secondary glioblastomas (p<0.001). The concurrence of p53 mutation and EGFR amplification was revealed in only 2 out of 15 primary glioblastomas and none among the secondary glioblastomas. Immunoreactivities for EGFR were noted in 66.7% of primary glioblastomas and in 9.5% of secondary glioblastomas (p<0.001). A correlation between EGFR amplification and EGFR immunopositivity in glioblastomas was observed in 91.7% of the cases. These data indicate that EGFR amplification and p53 mutations are two independent genetic events in the development of glioblastomas.