Automatic three-dimensional segmentation of mouse embryonic stem cell nuclei by utilising multiple channels of confocal fluorescence images.

Time-lapse confocal fluorescence microscopy images from mouse embryonic stem cells (ESCs) carrying reporter genes, histone H2B-mCherry and Mvh-Venus, have been used to monitor dynamic changes in cellular/differentiation characteristics of live ESCs. Accurate cell nucleus segmentation is required to analyse the ESC dynamics and differentiation at a single cell resolution. Several methods used concavities on nucleus contours to segment overlapping cell nuclei. Our proposed method evaluates not only the concavities but also the size and shape of every 2D nucleus region to determine if any of the strait, extrusion, convexity and large diameter criteria is satisfied to segment overlapping nuclei inside the region. We then use a 3D segmentation method to reconstruct simple, convex, and reasonably sized 3D nuclei along the image stacking direction using the radius and centre of every segmented region in respective microscopy images. To avoid false concavities on nucleus boundaries, fluorescence images of the H2B-mCherry reporter are used for localisation of cell nuclei and Venus fluorescence images are used for determining the cell colony ranges. We use a series of image preprocessing procedures to remove noise outside and inside cell colonies, and in respective nuclei, and to smooth nucleus boundaries based on the colony ranges.  We propose dynamic data structures to record every segmented nucleus region and solid in sets (volumes) of 3D confocal images. The experimental results show that the proposed image preprocessing method preserves the areas of mouse ESC nuclei on microscopy images and that the segmentation method effectively segment out every nucleus with a reasonable size and shape. All 3D nuclei in a set (volume) of confocal microscopy images can be accessed by the dynamic data structures for 3D reconstruction. The 3D nuclei in time-lapse confocal microscopy images can be tracked to calculate cell movement and proliferation in consecutive volumes for understanding the dynamics of the differentiation characteristics about ESCs. LAY DESCRIPTION: Embryonic stem cells (ESCs) are considered as an ideal source for basic cell biology study and producing medically useful cells in vitro. This study uses time-lapse confocal fluorescence microscopy images from mouse ESCs carrying reporter gene to monitor dynamic changes in cellular/differentiation characteristics of live ESCs. To automate analyses of ESC differentiation behaviours, accurate cell nucleus segmentation to distinguish respective cells are required. A series of image preprocessing procedures are implemented to remove noise in live-cell fluorescence images but yield overlapping cell nuclei. A segmentation method that evaluates boundary concavities and the size and shape of every nucleus is then used to determine if any of the strait, extrusion, convexity, large and local minimum diameter criteria satisfied to segment overlapping nuclei. We propose a dynamic data structure to record every newly segmented nucleus. The experimental results show that the proposed image preprocessing method preserves the areas of mouse ESC nuclei and that the segmentation method effectively detects overlapping nuclei. All segmented nuclei in confocal images can be accessed using the dynamic data structures to be visualised and manipulated for quantitative analyses of the ESC differentiation behaviours. The manipulation can be tracking of segmented 3D cell nuclei in time-lapse images to calculate their dynamics of differentiation characteristics.

Semi-mechanistic autoinduction model of midazolam in critically ill patients: population pharmacokinetic analysis.

WHAT IS KNOWN AND OBJECTIVE: Midazolam (MDZ) is commonly used for sedating critically ill patients. The daily dose required for adequate sedation increases in increments over 100 h after administration. The objectives of this study were to characterize the MDZ pharmacokinetics in critically ill patients and to describe the phenomenon of increasing daily dose by means of population pharmacokinetic analysis. METHODS: Data were obtained from 30 patients treated in an intensive care unit. The patients received MDZ intravenously as a combination of bolus and continuous infusion. Serum MDZ concentration was assayed by high-performance liquid chromatography. Population pharmacokinetic analysis was performed using the NONMEM software package. The alteration of clearance unexplained by demographic factors and clinical laboratory data was described as an autoinduction of MDZ clearance using a semi-mechanistic pharmacokinetic-enzyme turnover model. RESULTS AND DISCUSSION: The final population pharmacokinetic model was a one-compartment model estimated by incorporating a semi-mechanistic pharmacokinetic-enzyme turnover model for clearance, taking autoinduction into account. A significant covariate for MDZ clearance was total bilirubin. An increase in total bilirubin indicated a reduction in MDZ clearance. From simulation using the population pharmacokinetic parameters obtained in this study, MDZ clearance increased 2·3 times compared with pre-induced clearance 100 h after the start of 12·5 mg/h continuous infusion. WHAT IS NEW AND CONCLUSION: Autoinduction and total bilirubin were significant predictors of the clearance of MDZ in this population. Step-by-step dosage adjustment using this population pharmacokinetic model may be useful for establishing a MDZ dosage regimen in critically ill patients.

Phase III placebo-controlled double-blind randomized trial of radiotherapy for stage IIB-IVA cervical cancer with or without immunomodulator Z-100: a JGOG study.

BACKGROUND: Based on the result of our previous study showing better overall survival (OS) at the lower dose (0.2 µg) of immunomodulator Z-100 than higher dose (40 µg) in patients with locally advanced cervical cancer who received radiotherapy, we conducted a placebo-controlled double-blind randomized trial. PATIENTS AND METHODS: Patients of stages IIB-IVA squamous cell carcinoma of the uterine cervix were randomly assigned to receive Z-100 at 0.2 µg (Z) or placebo (P). The study agent was given subcutaneously twice a week during the radiotherapy, followed by maintenance therapy by administering once every 2 weeks until disease progression. Primary end point was OS, and secondary end points were recurrence-free survival, and toxicity. RESULTS: A total of 249 patients were randomized. Death events occurred extremely slower than expected, and Independent Data Monitoring Committee recommended to analyze the survival result prematurely. The 5-year OS rate was 75.7% [95% confidence interval (CI) 66.4% to 82.8%] for Arm Z and 65.8% (95% CI 56.2% to 73.8%) for Arm P (P = 0.07); hazard ratio was 0.65 (95% CI 0.40-1.04). Survival benefit in Arm Z was observed regardless of chemoradiation or radiation alone. There was no trend in recurrence-free survival between the two arms. Side-effects were not different between two arms. CONCLUSION: Z-100 showed a trend of improvement on OS in locally advanced cervical cancer, although the statistical power was less than anticipated because survival rates were unexpectedly higher than expected for both arms. Validation of potential survival benefit of immune modulation should be made. TRIAL REGISTRATION: umin.ac.jp/ctr Identifier: C000000221.

Phase III randomised controlled trial of neoadjuvant chemotherapy plus radical surgery vs radical surgery alone for stages IB2, IIA2, and IIB cervical cancer: a Japan Clinical Oncology Group trial (JCOG 0102).

BACKGROUND: A phase III trial was conducted to determine whether neoadjuvant chemotherapy (NACT) before radical surgery (RS) improves overall survival. METHODS: Patients with stage IB2, IIA2, or IIB squamous cell carcinoma of the uterine cervix were randomly assigned to receive either BOMP (bleomycin 7 mg days 1-5, vincristine 0.7 mg m(-2) day 5, mitomycin 7 mg m(-2) day 5, cisplatin 14 mg m(-2) days 1-5, every 3 weeks for 2 to 4 cycles) plus RS (NACT group) or RS alone (RS group). Patients with pathological high-risk factors received postoperative radiotherapy (RT). The primary end point was overall survival. RESULTS: A total of 134 patients were randomly assigned to treatment. This study was prematurely terminated at the first planned interim analysis because overall survival in the NACT group was inferior to that in the RS group. Patients who received postoperative RT were significantly lower in the NACT group (58%) than in the RS group (80%; P=0.015). The 5-year overall survival was 70.0% in the NACT group and 74.4% in the RS group (P=0.85). CONCLUSION: Neoadjuvant chemotherapy with BOMP regimen before RS did not improve overall survival, but reduced the number of patients who received postoperative RT.

Surgery for endometrial cancers with suspected cervical involvement: is radical hysterectomy needed (a GOTIC study)?

BACKGROUND: Radical hysterectomy is recommended for endometrial adenocarcinoma patients with suspected gross cervical involvement. However, the efficacy of operative procedure has not been confirmed. METHODS: The patients with endometrial adenocarcinoma who had suspected gross cervical involvement and underwent hysterectomy between 1995 and 2009 at seven institutions were retrospectively analysed (Gynecologic Oncology Trial and Investigation Consortium of North Kanto: GOTIC-005). Primary endpoint was overall survival, and secondary endpoints were progression-free survival and adverse effects. RESULTS: A total of 300 patients who underwent primary surgery were identified: 74 cases with radical hysterectomy (RH), 112 patients with modified radical hysterectomy (mRH), and 114 cases with simple hysterectomy (SH). Median age was 47 years, and median duration of follow-up was 47 months. There were no significant differences of age, performance status, body mass index, stage distribution, and adjuvant therapy among three groups. Multi-regression analysis revealed that age, grade, peritoneal cytology status, and lymph node involvement were identified as prognostic factors for OS; however, type of hysterectomy was not selected as independent prognostic factor for local recurrence-free survival, PFS, and OS. Additionally, patients treated with RH had longer operative time, higher rates of blood transfusion and severe urinary tract dysfunction. CONCLUSION: Type of hysterectomy was not identified as a prognostic factor in endometrial cancer patients with suspected gross cervical involvement. Perioperative and late adverse events were more frequent in patients treated with RH. The present study could not find any survival benefit from RH for endometrial cancer patients with suspected gross cervical involvement. Surgical treatment in these patients should be further evaluated in prospective clinical studies.

Salubrinal reduces expression and activity of MMP13 in chondrocytes.

OBJECTIVE: Stress to the endoplasmic reticulum (ER) and inflammatory cytokines induce expression and activity of matrix metalloproteinase 13 (MMP13). Since a synthetic agent, salubrinal, is known to alleviate ER stress and attenuate nuclear factor kappa B (NFκB) signaling, we addressed a question whether upregulation of MMP13 by ER stress and cytokines is suppressed by administration of salubrinal. METHODS: Using C28/I2 human chondrocytes, we applied ER stress with tunicamycin and inflammatory distress with tumor necrosis factor α (TNFα) and interleukin 1ß (IL1ß). RNA interference with siRNA specific to NFκB p65 (RelA) was employed to examine a potential involvement of NFκB signaling in salubrinal's action in regulation of MMP13. We also employed primary human chondrocytes and evaluated MMP13 activity. RESULTS: The result showed that tunicamycin activated p38 mitogen-activated protein kinase (MAPK), while inflammatory cytokines activated p38 MAPK and NFκB. In both cases, salubrinal significantly reduced expression and activity of MMP13. Silencing NFκB reduced inflammatory cytokine-driven upregulation of MMP13 activity. CONCLUSIONS: The results demonstrate that salubrinal downregulates expression and activity MMP13 through p38 and NFκB signaling, suggesting its potential usage to treat degenerative diseases such as osteoarthritis.

Rac1 mediates load-driven attenuation of mRNA expression of nerve growth factor beta in cartilage and chondrocytes.

OBJECTIVES: To determine effect of gentle loads applied to the knee on mRNA expression of nerve growth factor, particularly, the active beta subunit (NGFß) in cartilage and chondrocyte. METHODS: Cyclic compressive loads in vivo and fluid flow in vitro were used to determine the mRNA levels. Alteration of Rac1 GTPase as well as effect of salubrinal, a specific inhibitor of eIF2α phosphatase was assessed using fluorescence resonance energy transfer (FRET)-based Rac1 biosensor. RESULTS: Knee loading at 1 N reduced mRNA levels of NGFß and its low affinity receptor, p75 in cartilage and subchondral bone. In cartilage, knee loading at 1 N reduced the phosphorylation level of p38 MAPK (p38-p) and activity of Rac1 GTPase. Consistent with in vivo results, fluid flow at 5 and 10 dyn/cm(2) reduced mRNA levels of NGFß and p75 in C28/I2 human chondrocytes. SB203580, which decreases p38-p, reduced the mRNA levels of NGFß and p75. Silencing Rac1 by siRNA decreased the levels of p38-p and NGFß mRNA but not p75. Furthermore, administration of salubrinal reduced FRET-based activity of Rac1 as well as the mRNA levels of NGFß and p75. CONCLUSIONS: These results provide evidence that mechanical stimulation and salubrinal may attenuate pain perception-linked NGFß signaling through Rac1-mediated p38 MAPK.

UGT1A1 genotype-specific phase I and pharmacokinetic study for combination chemotherapy with irinotecan and cisplatin: a Saitama Tumor Board study.

INTRODUCTION: Genotyping of UGTI1Al could be useful for prediction of severe toxicities for patients treated with irinotecan; however, genotype-based recommended dose (RD) has not been established. The aim of the present study was to determine the RD of irinotecan in combination with cisplatin (CPT-P) for individuals with or without UGT1A1 polymorphisms. MATERIALS AND METHODS: According to polymorphisms of UGTIAl*28, *6, and *27, RDs were determined by three-case cohort methods for patients with wild-type and heterotype, and by inter-patient dose escalation for homotype patients. Pharmacokinetic studies were also evaluated. During May 2009 and July 2011, 18 Japanese patients were enrolled; 16 patients with ovarian carcinoma, and two cases with cervical cancer. The RD of irinotecan was determined as 50 mg/m2 for the patients with wild-type, 40 mg/m2 for those with heterotype, and 30 mg/m2 for homotype UGT IAl genotype. RESULTS: Patients with homotype UGTIAl1 alleles had a significantly lower glucuronidation ratio in comparison with UGTIAI wild-type and heterotype cases. CONCLUSION: UGT1A1 genotype-based RDs of irinotecan in CPT-P therapy were determined. Further studies to investigate efficacy of the RD including response evaluation are needed to confirm the present results.

The precision of PiCCO® measurements in hypothermic post-cardiac arrest patients.

The aim of the present study was to determine the precision of the PiCCO(®) system for post-cardiac arrest patients who underwent therapeutic hypothermia. The precision of the measurements for cardiac output, global end-diastolic volume, extravascular lung water and the pulmonary vascular permeability index was assessed using the least significant change; this was regarded as precise when less than 15%. A total of 462 measurement sets were prospectively performed on 88 patients following successful resuscitation after cardiac arrest. Using the mean value of three injections for a measurement, the least significant change for the cardiac output, global end-diastolic volume, extravascular lung water and pulmonary vascular permeability index measurements were found to be 7.8%, 8.5%, 7.8% and 12.1%, respectively. No significant differences between hypothermia (n=150) and non-hypothermia (n=312) were found. The PiCCO-derived variables were found to be precise for post-cardiac arrest patients even under conditions of varying body temperature.

Anxiety relaxation during MRI with a patient-friendly audiovisual system.

INTRODUCTION: Many patients experience anxiety, not limited to claustrophobia, before magnetic resonance imaging (MRI) examination. We performed a non-randomized controlled trial to evaluate whether a patient-friendly audiovisual (AV) system in the MR scanner room reduces patient anxiety. METHODS: We randomly selected 61 participants from outpatients who required brain MRI examination. Patients were informed that they could choose to undergo an MRI examination with a patient-friendly AV system (Ambient Experience, Philips Healthcare, Best, The Netherlands) or the standard system. To complete the MRI examination without affecting clinical practice, all patients who preferred the patient-friendly AV system were assigned to the preferring AV group. Patients who indicated that either system was acceptable were randomly assigned to the no preference but allocated AV group or control (using the standard system) groups. In both groups, state anxiety using the State-Trait Anxiety Inventory (STAI) was assessed before and after the MRI examination (A-State-before and A-State-after MRI, respectively). The changes in A-State-before and A-State-after MRI were categorized as follows: relieved high-state anxiety, no change in high-state anxiety, stable easiness, and intensified anxiety. RESULTS: Among the 61 included patients, 19 were assigned to the preferring AV group, 20 to the no preference but allocated AV group, and 22 to the control group. There were no significant differences between the group. However, in patients with high-state anxiety before MRI, the preferring AV group and the no preference but allocated AV group, which used the patient-friendly AV system, relieved high-state anxiety by 63.6% (7 of 11 patients) and 81.8% (9 of 11 patients), respectively. In contrast, the control group using the standard system relieved high-level anxiety by only 42.9% (three out of seven patients). CONCLUSION: The patient-friendly AV system may reduce anxiety in patients undergoing MRI examinations. IMPLICATIONS FOR PRACTICE: The patient-friendly AV system may reduce anxiety in patients undergoing MRI examination by providing a more patient-centered MRI examination environment. These findings may help ameliorate negative perceptions associated with MRI examination.

MR Imaging Findings of Carcinoma Ex Pleomorphic Adenoma Related to Extracapsular Invasion and Prognosis.

BACKGROUND AND PURPOSE: MR imaging can reflect the pathologic progression of carcinoma ex pleomorphic adenoma (CXPA). This study aimed to identify the imaging findings related to extracapsular invasion of CXPA. Additionally, the pathologic background of these findings was investigated. MATERIALS AND METHODS: This retrospective study included 37 patients with histologically confirmed CXPA. Three radiologists independently evaluated whether the CXPA showed the following characteristic MR imaging findings: border, capsule, the corona sign on fat-saturated T2WI and contrast-enhanced fat-saturated T1WI, and the black ring sign. The corona sign appeared larger on fat-saturated and/or contrast-enhanced fat-saturated T1WI than on T1WI. The black ring sign was defined as an intratumoral nodule with a thick low-intensity rim on T2WI. Interreader agreement of the visual assessment was performed using κ analysis, and MR imaging and histopathologic findings were also correlated. Kaplan-Meier survival and the log-rank test were used to estimate the 3-year disease-free survival. RESULTS: MR imaging findings, especially peritumoral findings, showed a significant difference between invasive and noninvasive CXPA. The reliability was poor for the border and capsule. In contrast, it was good for the corona sign on fat-saturated and contrast-enhanced fat-saturated T1WI and the black ring sign. Pathologically, the corona sign reflected the invasiveness of the tumor and inflammatory cells, while the black ring sign reflected hyalinization or fibrosis. The corona sign also showed a significant difference in the 3-year disease-free survival. CONCLUSIONS: MR imaging findings, including the corona and black ring signs, reliably differentiated invasive and noninvasive CXPA. The corona sign can be used as a prognostic factor for CXPA.

Prognostic Factors of Stroke-Like Migraine Attacks after Radiation Therapy (SMART) Syndrome.

BACKGROUND AND PURPOSE: Prognostic factors of stroke-like migraine attacks after radiation therapy (SMART) syndrome have not been fully explored. This study aimed to assess clinical and imaging features to predict the clinical outcome of SMART syndrome. MATERIALS AND METHODS: We retrospectively reviewed the clinical manifestations and imaging findings of 20 patients with SMART syndrome (median age, 48 years; 5 women) from January 2016 to January 2020 at 4 medical centers. Patient demographics and MR imaging features at the time of diagnosis were reviewed. This cohort was divided into 2 groups based on the degree of clinical improvement (completely versus incompletely recovered). The numeric and categoric variables were compared as appropriate. RESULTS: There were statistically significant differences between the completely recovered group (n = 11; median age, 44 years; 2 women) and the incompletely recovered group (n = 9; median age, 55 years; 3 women) in age, months of follow-up, and the presence of steroid treatment at diagnosis (P = .028, .002, and .01, respectively). Regarding MR imaging features, there were statistically significant differences in the presence of linear subcortical WM susceptibility abnormality, restricted diffusion, and subcortical WM edematous changes in the acute SMART region (3/11 versus 8/9, P = .01; 0/11 versus 4/9, P = .026; and 2/11 versus 7/9, P = .022, respectively). Follow-up MRIs showed persistent susceptibility abnormality (11/11) and subcortical WM edematous changes (9/9), with resolution of restricted diffusion (4/4). CONCLUSIONS: Age, use of steroid treatment at the diagnosis of SMART syndrome, and MR imaging findings of abnormal susceptibility signal, restricted diffusion, and subcortical WM change in the acute SMART region can be prognostic factors in SMART syndrome.

An Investigation of Water Diffusivity Changes along the Perivascular Space in Elderly Subjects with Hypertension.

BACKGROUND AND PURPOSE: Hypertension may be related to alterations of the glymphatic system, a waste metabolite drainage system in the brain. We aimed to investigate analysis along the perivascular space index changes in elderly subjects with hypertension. MATERIALS AND METHODS: Diffusion-weighted images were acquired from 126 subjects, including 63 subjects with hypertension (25 men and 38 women; mean age, 72.45 years) and 63 age- and sex-matched controls (25 men and 38 women; mean age, 72.16 years). We calculated the analysis along the perivascular space index as a ratio of the mean of x-axis diffusivities in the projection and association areas to the mean of y-axis diffusivity in the projection area and z-axis diffusivity in the association area. The left, right, and mean analysis along the perivascular space indices of both hemispheres were compared between the hypertension and control groups using a Mann-Whitney U test. The Spearman correlation coefficient was used to assess the correlation between the left, right, and mean ALPS indices and blood pressure and pulse pressure. RESULTS: The left (P = .011) and mean (P = .024) analysis along the perivascular space indices of the hypertension group were significantly lower than that of the control group. The left, right, and mean analysis along the perivascular space indices of all subjects were significantly negatively correlated with blood pressure values (r = -0.200 to -0.278, P = .002-0.046) and pulse pressure values (r = -0.221 to -0.245, P = .006-0.013). CONCLUSIONS: Our results are consistent with a model in which hypertension causes glymphatic dysfunction.

Neutron powder diffraction refinement of PbZr(1†-†x)Ti(x)O3.

Rietveld refinement of different structural models using neutron diffraction data for a series of powders of lead zirconate titanate, PbZr(1 - x)Ti(x)O(3) (PZT), is described. It is found that at all the compositions and temperatures studied the best results include contributions from more than one phase in order to fit the data. Consequently a new phase diagram is proposed.

Lumbosacral subdural hematoma associated with cranial subdural hematoma and craniocerebral surgery: Three cases and a systemic literature review.

OBJECTIVE: The authors aim to focus on lumbosacral subdural hematoma (SDH) associated with cranial subdural hematoma and craniocerebral surgery, which has been rarely reported. MATERIAL AND METHODS: They present 3 cases of lumbosacral SDH, including 2 associated with cranial chronic SDH and 1 following craniotomy for neck clipping of cerebral aneurysm. Using a PubMed search, they also provide a systemic literature review to summarize pathogenesis, treatment and outcome. RESULTS: All cases presented with bilateral radiating leg pain, and recovered completely by conservative managements. Predisposing factors were trauma, anticoagulant therapy and brain atrophy. Literature review revealed 54 such cases, in which 28 cases associated with cranial SDH and 26 cases associated with craniocerebral surgery. In both group, main symptoms were low back and radiating leg pain, and sensorimotor deficits. Regardless of treatments, conservatively or surgically, outcome was favorable. Migration of cranial hematoma is most supported pathogenesis, while intracranial hypotension due to cerebrospinal fluid overdrainage procedures may also be a contributing factor for cases associated with craniocerebral surgery. CONCLUSIONS: Lumbosacral SDH should be considered in patients present with unexpected low back and radiating leg pains associated with cranial SDH and craniocerebral surgery. Conservative treatment would be reasonable for cases with mild symptoms as the first treatment of choice.

Selective Motor Control is a Clinical Correlate of Brain Motor Tract Impairment in Children with Spastic Bilateral Cerebral Palsy.

BACKGROUND AND PURPOSE: Selective voluntary motor control is an important factor influencing gross motor function, interjoint coordination, and the outcome of hamstring-lengthening surgery in spastic cerebral palsy. Using DTI, we investigated whether selective voluntary motor control would show strong correlations with WM motor tract microstructure and whether selective voluntary motor control is more sensitive to global WM impairment than gross motor function. MATERIALS AND METHODS: Children with spastic bilateral cerebral palsy born preterm and typically developing children were recruited. The Selective Control Assessment of the Lower Extremity (SCALE) and Gross Motor Function Measure (GMFM) were assessed in participants with cerebral palsy. Participants underwent brain MR imaging to collect DWI data. Tract-Based Spatial Statistics was used to analyze the WM for between-group differences and correlations with SCALE and GMFM. ROI analyses compared motor regions. RESULTS: Twelve children with cerebral palsy (mean age, 11.5 years) and 12 typically developing children (mean age, 10.3 years) participated. Altered DTI outcomes were found throughout the whole brain for the cerebral palsy group. SCALE, developed to evaluate selective voluntary motor control in cerebral palsy, showed significant positive correlations with fractional anisotropy in more WM voxels throughout the whole brain and for motor regions, including the corticospinal tract and corpus callosum, compared with GMFM. A significant negative correlation between radial diffusivity and SCALE, but not GMFM, was found within the corpus callosum. CONCLUSIONS: SCALE was a more sensitive clinical correlate of motor and whole-brain WM tract impairment in children with spastic bilateral cerebral palsy, suggesting greater anisotropy and myelination in these regions for those with higher selective voluntary motor control.

Single crystal study of competing rhombohedral and monoclinic order in lead zirconate titanate.

Neutron diffraction data obtained on single crystals of PbZr(1-x)Ti(x)O3 with x=0.325 and x=0.460, which lie on the pseudorhombohedral side of the morphotropic phase boundary, suggest a coexistence of rhombohedral (R3m/R3c) and monoclinic (Cm) domains and that monoclinic order is enhanced by Ti substitution. A monoclinic phase with a doubled unit cell (Cc) is ruled out as the ground state.

Observation of three-dimensional internal structure of steel materials by means of serial sectioning with ultrasonic elliptical vibration cutting.

A three-dimensional (3D) internal structure observation system based on serial sectioning was developed from an ultrasonic elliptical vibration cutting device and an optical microscope combined with a high-precision positioning device. For bearing steel samples, the cutting device created mirrored surfaces suitable for optical metallography, even for long-cutting distances during serial sectioning of these ferrous materials. Serial sectioning progressed automatically by means of numerical control. The system was used to observe inclusions in steel materials on a scale of several tens of micrometers. Three specimens containing inclusions were prepared from bearing steels. These inclusions could be detected as two-dimensional (2D) sectional images with resolution better than 1 mum. A three-dimensional (3D) model of each inclusion was reconstructed from the 2D serial images. The microscopic 3D models had sharp edges and complicated surfaces.

Biochemical and immunohistochemical characterization of the amyloid in canine amyloid-producing odontogenic tumor.

The amyloid of canine amyloid-producing odontogenic tumor (APOT) was evaluated biochemically and immunohistochemically. The N-terminal amino-acid sequence of purified amyloid protein from a canine APOT was strikingly similar to the sequence in both rat ameloblastin and porcine sheathlin. Immunohistochemically, the amyloid in APOT from 9 dogs was strongly reactive with anti-rat ameloblastin, anti-porcine sheathlin, and anti-canine APOT amyloid and weakly reactive with anti-porcine amelogenin but negative for antibodies to cytokeratins, vimentin, desmin, alpha-smooth muscle actin, amyloid A, glial fibrillary acidic protein, or S100 protein. The neoplastic epithelial cells of APOT were focally reactive with antibodies to ameloblastin, sheathlin, amelogenin, and canine APOT amyloid. The similarity in amino-acid sequence of the amyloid protein of canine APOT to that of enamel proteins, such as ameloblastin, sheathlin, and amelogenin, and the expression of these antigens in both APOT amyloid and in the neoplastic cells suggest that the amyloid of canine APOT is derived from enamel proteins secreted by ameloblasts.

Evidence for the organization of chromatin in megabase pair-sized loops arranged along a random walk path in the human G0/G1 interphase nucleus.

We determined the folding of chromosomes in interphase nuclei by measuring the distance between points on the same chromosome. Over 25,000 measurements were made in G0/G1 nuclei between DNA sequences separated by 0.15-190 megabase pairs (Mbp) on three human chromosomes. The DNA sequences were specifically labeled by fluorescence in situ hybridization. The relationship between mean-square interphase distance and genomic separation has two linear phases, with a transition at approximately 2 Mbp. This biphasic relationship indicates the existence of two organizational levels at scales > 100 kbp. On one level, chromatin appears to be arranged in large loops several Mbp in size. Within each loop, chromatin is randomly folded. On the second level, specific loop-attachment sites are arranged to form a supple, backbonelike structure, which also shows characteristic random walk behavior. This random walk/giant loop model is the simplest model that fully describes the observed large-scale spatial relationships. Additional evidence for large loops comes from measurements among probes in Xq28, where interphase distance increases and then locally decreases with increasing genomic separation.