Clinical, imaging, and pathological characteristics of congenital infiltrating lipomatosis of the face

Congenital infiltrating lipomatosis of the face (CILF) is a rare congenital disease of the head and neck region. In this study, the cases of 20 patients diagnosed with CILF were reviewed retrospectively to analyse the characteristics of the disease. The symptoms, signs, and clinical progression were investigated. Radiological changes were analysed according to the distribution of the trigeminal nerve. The pathological features of the fatty facial lesions, jaw hyperplasia, and lingual lesions were further identified. All 20 patients demonstrated hemifacial hypertrophy at birth. None had a family history of the disease. Significant radiological features of CILF (prevalence ≥90%) included thickened buccal subcutaneous fat, palatal submucosal fat, and temporal subcutaneous fat, maxillary tuberosity heteroplasia, and fatty infiltration of the masseteric intermuscular space. With regard to the trigeminal nerve, the frontal branch region (CNV1) was rarely affected, while the maxillary (CNV2) and mandibular (CNV3) branch regions showed considerable changes. Pathologically, CILF was observed to be characterized by the infiltration of mature adipose tissue into the adjacent buccal soft tissue, osteal remodelling surrounded by sheets of mature lipocytes and supporting fibrovascular stroma, and lingual hamartoma. In summary, CILF exhibits distinct characteristics that are related to the regions controlled by the maxillary and mandibular branches of the trigeminal nerve, suggesting that CILF may be associated with early neural development.

NKG2A and HLA-E define an alternative immune checkpoint axis in bladder cancer

Programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1)-blockade immunotherapies have limited efficacy in the treatment of bladder cancer. Here, we show that NKG2A associates with improved survival and responsiveness to PD-L1 blockade immunotherapy in bladder tumors that have high abundance of CD8+ T cells. In bladder tumors, NKG2A is acquired on CD8+ T cells later than PD-1 as well as other well-established immune checkpoints. NKG2A+ PD-1+ CD8+ T cells diverge from classically defined exhausted T cells through their ability to react to human leukocyte antigen (HLA) class I-deficient tumors using T cell receptor (TCR)-independent innate-like mechanisms. HLA-ABC expression by bladder tumors is progressively diminished as disease progresses, framing the importance of targeting TCR-independent anti-tumor functions. Notably, NKG2A+ CD8+ T cells are inhibited when HLA-E is expressed by tumors and partly restored upon NKG2A blockade in an HLA-E-dependent manner. Overall, our study provides a framework for subsequent clinical trials combining NKG2A blockade with other T cell-targeted immunotherapies, where tumors express higher levels of HLA-E.

Pro-angiogenic effect of exosomal microRNA-103a in mice with rheumatoid arthritis via the downregulation of hepatocyte nuclear factor 4 alpha and activation of the JAK/STAT3 signaling pathway

Rheumatoid arthritis (RA) is characterized by inflammation of the synovial membrane, accompanied by hyperplasia and neo-angiogenesis, which promote local inflammation. Macrophage-derived exosomes have been reported to enhance inflammation and the immune response. In the present study, we identified a novel exosomal microRNA (miR)-103a, which aids in the regulation of inflammation and angiogenesis in mice with RA, and attempted to identify the underlying mechanism. Initially, a mouse model of RA was established. Thereafter, exosomes were isolated from macrophage RAW264.7 cells and evaluated through transmission electron microscopy and nanoparticle tracking analysis. After prediction and verification of the target genes of miR-103a, RT-qPCR was used to assess miR-103a and HNF4A expression in mice with RA. High expression of miR-103a and low expression of HNF4A were observed in mice with RA, thus, miR-103a was found to target and downregulate HNF4A. Exosomal miR-103a promoted inflammation and angiogenesis in mice with RA which was accompanied by an increase in the levels of factors associated with inflammation and angiogenesis. However, an opposite trend was observed upon HNF4A elevation. Exosomal miR-103a was also found to activate the JAK/STAT3 signaling pathway. In conclusion, exosomal miR-103a inhibited the expression of HNF4A to activate the JAK/STAT3 signaling pathway, thereby exacerbating RA in mice.

[Urinary retinol binding protein and β2-microglobulin were associated with urinary albumin to creatinine ratio and renal function in hospitalized diabetic patients]

Objective: To explore the associations of urinary retinol binding protein (RBP) and β₂-microglobulin (β₂-MG) with urinary albumin to creatinine ratio (UACR) and renal function in hospitalized patients with type 2 diabetes mellitus (T2DM). Methods: A total of 1 030 Chinese patients with T2DM were included in this study. The subjects were divided into the UACR normal group (<30 mg/g), microalbuminuria group (30-300 mg/g) and macroalbuminuria group (>300 mg/g). Patients with normal UACR were further divided into two groups according to the estimated glomerular filtration rate (eGFR): the eGFR low group (<90 ml·min^-1·1.73m^-2) and the normal eGFR group (≥90 ml·min^-1·1.73m^-2). Urine RBP and β₂-MG levels among the groups were compared. Multiple linear regression analyses were applied to evaluate risk factors of urine RBP and β₂-MG. Results: In all patients (n=1 030), urine RBP and β₂-MG increased gradually with the increase of UACR across the three groups, the proportions of abnormal urine RBP (>0.7 mg/L) and β₂-MG (>370 μg/L) in these groups were 3.8%, 8.5%, 39.0% (P<0.001), and 12.9%, 26.7%, 46.8% (P<0.001), respectively. In the UACR normal group (n=788), 12.2% of the patients were with eGFR<90 ml·min^-1·1.73m^-2. The proportion of abnormal β₂-MG (>370 μg/L) was higher in the eGFR low group than that in the eGFR normal group (29.2% vs. 10.7%, P<0.001). Multivariate linear stepwise regression analyses were performed using natural logarithm of urine RBP or β₂-MG as dependent variable, and showed that urine RBP was independently associated with UACR (β=0.0005, P<0.001), serum creatinine (β=0.006, P<0.001) and glycosylated hemoglobin A1c (β=0.050, P=0.001), and β₂-MG was independently correlated with UACR (β=0.000 4, P<0.001), serum creatinine (β=0.011, P<0.001), systolic blood pressure (β=0.005, P=0.031) and fasting blood-glucose (β=0.027, P=0.046). Conclusions: Urine RBP and β₂-MG are positively associated with high UACR and impaired renal function in T2DM patients, and these changes could occur before UACR and eGFR turned out to be abnormal. It is recommended that urine RBP and β₂-MG be detected as early as possible to identify diabetic kidney disease in patients with normal UACR and eGFR.

Baicalin attenuates lipopolysaccharide-induced renal tubular epithelial cell injury by inhibiting the TXNIP/NLRP3 signalling pathway via increasing miR-223-3p expression

Baicalin has been used in China to treat inflammation-related diseases, such as inflammation-induced acute kidney injury (AKI). However, the specific mechanism of baicalin remains unclear. To observe the protective effects of baicalin on lipopolysaccharide (LPS)-induced inflammatory injury of renal tubular epithelial cells (HK-2 cells) and to explore its protective mechanism. LPS (1 mg/L) was used to induce an HK-2 cell inflammatory injury model in vitro. The cells were divided into seven groups: the normal control group, LPS-induced group, LPS plus 5 μmol/L baicalin treatment group, LPS plus 15 μmol/L baicalin treatment group, LPS plus 25 μmol/L baicalin treatment group, LPS plus 50 μmol/L baicalin treatment group, and LPS plus 75 μmol/L baicalin treatment group. 3-(4,5-dimethyl-2-thiazolyl)-2,5- diphenyl-2-H-tetrazolium bromide (MTT) assay was employed for detecting the relative survival rate of HK-2 cells. Enzyme-linked immunosorbent assay was used for detecting the levels of inflammatory factors, including interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α). Moreover, the expression of inducible nitric oxide synthase (iNOS); cyclooxygenase-2 (COX-2); nuclear factor kB65 (NF-κB65); phosphorylated NF-κB inhibitory protein-α (p-IκB-α); NF-κB inhibitory protein (IκB); human thioredoxin interacting protein (TXNIP); and human NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) were determined by Western blot analysis. The expression levels of NLRP3 and TXNIP mRNA and miR-223-3p were determined by RT-PCR. Results found that the relative survival rate of HK-2 cells treated with different baicalin concentrations was significantly increased (P<0.05) and the levels of the inflammatory factors IL-6, IL-1β, and TNF-α were significantly decreased (P<0.05) compared with those of the LPS-induced group. The expression levels of the inflammatory proteins inducible nitric oxide synthase and cyclooxygenase-2 and the genes expressions of TXNIP and NLRP3 were significantly decreased in the cells (P<0.05), while the expression level of miR-223- 3p was significantly increased (P<0.05). These changes were induced in a dose-dependent manner. The results suggest that baicalin significantly inhibited the expression of inflammation-related proteins and alleviated LPS-induced inflammatory injury in HK-2 cells. The mechanism may be associated with the inhibition of activation of the TXNIP/NLRP3 inflammatory pathway, which might be mediated by increased expression of miR-223-3p. Thus, NLRP3 is a regulatory target of miR-223-3p.

Risk of ectopic pregnancy lowest with transfer of single frozen blastocyst

STUDY QUESTION

What type of transferred embryo is associated with a lower rate of ectopic pregnancy?

SUMMARY ANSWER

The lowest risk of ectopic pregnancy was associated with the transfer of blastocyst, frozen and single embryo compared with cleavage stage, fresh and multiple embryos.

WHAT IS KNOWN ALREADY

Ectopic pregnancy is a recognized complication following assisted reproductive technology (ART) treatment. It has been estimated that the rate of ectopic pregnancy is doubled in pregnancies following ART treatment compared with spontaneous pregnancies. However, it was not clear whether the excess rate of ectopic pregnancy following ART treatment is related to the underlying demographic factors of women undergoing ART treatment, the number of embryos transferred or the developmental stage of the embryo.

STUDY DESIGN, SIZE, DURATION

A population-based cohort study of pregnancies following autologous treatment cycles between January 2009 and December 2011 were obtained from the Australian and New Zealand Assisted Reproduction Technology Database (ANZARD). The ANZARD collects ART treatment information and clinical outcomes annually from all fertility centres in Australia and New Zealand.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Between 2009 and 2011, a total of 44 102 pregnancies were included in the analysis. The rate of ectopic pregnancy was compared by demographic and ART treatment factors. Generalized linear regression of Poisson distribution was used to estimate the likelihood of ectopic pregnancy. Odds ratios, adjusted odds ratios (AOR) and 95% confidence intervals (CI) were calculated.

MAIN RESULTS AND THE ROLE OF CHANCE

The overall rate of ectopic pregnancy was 1.4% for women following ART treatment in Australia and New Zealand. Pregnancies following single embryo transfers had 1.2% ectopic pregnancies, significantly lower than double embryo transfers (1.8%) (P < 0.01). The highest ectopic pregnancy rate was 1.9% for pregnancies from transfers of fresh cleavage embryo, followed by transfers of frozen cleavage embryo (1.7%), transfers of fresh blastocyst (1.3%), and transfers of frozen blastocyst (0.8%). Compared with fresh blastocyst transfer, the likelihood of ectopic pregnancy was 30% higher for fresh cleavage stage embryo transfers (AOR 1.30, 95% CI 1.07-1.59) and was consistent across subfertility groups. Transfer of frozen blastocyst was associated with a significantly decreased risk of ectopic pregnancy (AOR 0.70, 95% CI 0.54-0.91) compared with transfer of fresh blastocyst.

LIMITATIONS, REASON FOR CAUTION

A limitation of this population-based study is the lack of information available on clinical- specific protocols and processes for embryo transfer (i.e. embryo quality, cryopreservation protocol, transfer techniques, etc.) and the potential impact on outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

The lowest risk of ectopic pregnancy was associated with the transfer of a single frozen blastocyst. This finding adds to the increasing evidence of better perinatal outcomes following frozen embryo transfers. The approach of freezing all embryos in the initiated fresh cycle and transfer of a single frozen blastocyst in the subsequent thaw cycle may improve the overall pregnancy and birth outcomes following ART treatment, in part by reducing the ectopic pregnancy rate.

STUDY FUNDING/COMPETING INTERESTS

There is no funding for this study. Authors declared no competing interest related to this study.

Efficient inverted quantum-dot light-emitting devices with TiO2/ZnO bilayer as the electron contact layer

We have demonstrated an efficient inverted CdSe/CdS/ZnS core/shell quantum-dot light-emitting device (QD-LED) using a solution-processed sol-gel TiO2 and ZnO nanoparticle composite layer as an electron-injection layer with controllable morphology and investigated the electroluminescence mechanism. The introduction of the ZnO layer can lead to the formation of spin-coated uniform QD films and fabrication of high-luminance QD-LEDs. The TiO2 layer improves the balance of charge injection due to its lower electron mobility relative to the ZnO layer. These results offer a practicable platform for the realization of a trade-off between the luminance and efficiency in the inverted QD-LEDs with TiO2/ZnO composites as the electron contact layer.

Treatment outcomes of various types of tuberculosis in Pakistan, 2006 and 2007

Measuring treatment outcome is important for successful tuberculosis (TB) control programmes. The purpose of this study was to examine the outcomes of various types of TB cases registered in Pakistan over a 2-year period and compare those outcomes among the different provinces and regions of the country. A retrospective, cohort study was conducted in which TB treatment outcome reports were reviewed. Of the 349 694 pulmonary TB cases registered in Pakistan during 2006 and 2007, 309154 (88.4%) were treated successfully. Treatment success was significantly higher in new smear-positive cases and lower in retreatment cases. Among the provinces and regions, treatment success was significantly higher in 4 out of 8 provinces. Treatment success needs to be improved, particularly in retreatment cases. The national TB control programme should review the provincial and regional programmes and learn lessons from well-performing programmes. Patient factors that may affect the treatment outcome should be also studied.

Intralesional injection of pingyangmycin is a safe and effective treatment for microcystic lymphatic malformations in the tongue

Objective

To evaluate the efficacy and safety of intralesional injection of pingyangmycin for the treatment of microcystic lymphatic malformations (LMs) in the tongue.

Methods

Eighteen patients with tongue microcystic LMs were treated with intralesional injection of pingyangmycin. The concentration of the drug was 1 mg/mL with an addition of dexamethasone. Repeated injections were performed at an interval of 3–4 weeks. The results were evaluated by clinical examinations and Doppler ultrasonography scan. The follow-up period was 12 months to eight years after the last treatment and the mean follow-up time was three years. All patients received 1–8 injections (mean, 3.0 injections) for the whole course of treatment. The total dose of pingyangmycin administered was 8–64 mg (mean, 24 mg).

Results

Fifteen patients had complete response with no cosmetic or functional problems. Three patients with macroglossia had a reduction of 50–90% in the lesion size and needed secondary surgery. No serious complications were encountered.

Conclusion

The results suggested that intralesional injection of pingyangmycin is an effective and safe treatment for microcystic LMs in the tongue, and can be used as the first-line treatment protocol.

Intraosseous Venous Malformations of the Facial Bone: A Retrospective Study in 11 Patients

Objectives:

To investigate the clinical symptoms, computed tomography (CT) features and treatments of intraosseous venous malformations (IVM) that occur in the facial bone.

Methods and Results:

Eleven patients with facial IVM were treated with two surgical techniques, excision ( n = 4) or curettage ( n = 7). No recurrence was encountered at follow-up (45.8 ± 16.0 months). Postoperative deformities were left in two paediatric patients who were treated with excision.

Conclusions:

The diagnosis of IVM can be difficult and is mainly based on clinical symptoms and CT features. IVM should be differentiated from other lesions, including ameloblastoma, odontogenic cysts, osteosarcoma, aneurysmal bone cysts and arteriovenous malformations, among others. Conventional block biopsy should be replaced by fine needle aspiration cytology for further diagnosis. Curettage is a more appropriate method for IVM compared with excessive en-bloc osteotomy, while transosseous embolo-sclerotherapy may be a promising alternative method. Finally, the terminological confusion between ‘intraosseous haemangioma’ and ‘intraosseous venous malformation’ should be avoided according to the binary classification.

Sclerotherapy of voluminous venous malformation in head and neck with absolute ethanol under digital subtraction angiography guidance

OBJECTIVES

Venous malformation (VM) is the most common symptomatic low-flow vascular malformation, which predominantly occurs in the head and neck region. The aim of this paper was to evaluate the results of endovascular sclerotherapy of voluminous VM, when the lesion is either >or=15 cm in maximum diameter or the lesion invades more than one anatomical space, in the head and neck region using absolute ethanol under digital subtraction angiography (DSA) guidance.

METHODS

A total of 23 patients with head and neck VMs between October 2005 and December 2008 were retrospectively reviewed. All patients received direct puncture ethanol sclerotherapy under DSA guidance. Follow-up assessments were performed at 3-25 months after therapies were completed, and complications were reported in some cases.

RESULTS

All patients were satisfied with the results of therapy. Seventeen patients (73.9%) achieved excellent responses and six patients (26.1%) achieved good responses in magnetic resonance imaging assessments. Minor complications developed during the procedures, all of which were successfully managed with full recovery during follow-ups. Serious complications such as acute pulmonary hypertension, cardiovascular collapse and pulmonary embolism were not encountered.

CONCLUSION

It is concluded that sclerotherapy with absolute ethanol under DSA guidance is an important alternative therapy for voluminous and extensive VM, as the procedure is reasonably safe and offers good therapeutic results.

Reproducibility of regional placental vascularity/perfusion measurement using 3D power Doppler

OBJECTIVES

To assess reproducibility and regional variability of placental perfusion measurement using three-dimensional (3D) power Doppler VOCAL() (Virtual Organ Computer-aided AnaLysis).

METHODS

Twenty pregnant women at 26-34 weeks' gestation with normally grown, biophysically normal, singleton pregnancies with anterior placentae had placental power Doppler mapping data stored digitally from each of the four placental quadrants. Each was imaged by two investigators, with two datasets stored per investigator per quadrant. 5760 data values from the 320 datasets were evaluated by the same two investigators. Power Doppler imaging of the placental cord insertion was performed to generate a value for standardization as 'fractional moving blood volume' if appropriate. The vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated from spherical regions-of-interest to assess reproducibility within and between quadrants and between investigators for both acquisition and analysis.

RESULTS

We found extensive variability for all readings. For repeated measurements within the same dataset the intra-analyzer intraclass correlation coefficient (ICC) range was: 0.24-0.57 for VI, 0.33-0.78 for FI and 0.12-0.48 for VFI. The corresponding interanalyzer ICC range was: 0.38-0.92 for VI, 0.40-0.85 for FI and 0.10-0.92 for VFI. The intra-acquirer variability (paired t-test) mean differences range was: - 3.91 to 4.71 for VI, - 2.68 to 3.31 for FI and - 2.23 to 2.78 for VFI; the corresponding interacquirer variability (paired t-test) range was: - 1.92 to 5.18 for VI, - 3.06 to 2.04 for FI and - 1.69 to 2.60 for VFI. The regional variability range (coefficient of variation) was: 6.28-126.34% for VI, 2.26-49.01% for FI and 6.09-151.55% for VFI. For all analyzed data, FI showed least variability and cord values for VI were consistently 100% (mean VFI, 98.4 and 98.8 between observers).

CONCLUSIONS

There is insufficient evidence to support the meaning, reliability or reproducibility of VOCAL (VI, FI or VFI) as a tool to quantify placental perfusion, despite its use in multiple publications and journal submissions. There is poor reproducibility at the most fundamental level. Further investigation into the reproducibility of placental perfusion and quantification using VOCAL is required before development and application as a clinically useful tool.

Pten and p53 converge on c-Myc to control differentiation, self-renewal, and transformation of normal and neoplastic stem cells in glioblastoma

Glioblastoma (GBM) is a highly lethal primary brain cancer with hallmark features of diffuse invasion, intense apoptosis resistance and florid necrosis, robust angiogenesis, and an immature profile with developmental plasticity. In the course of assessing the developmental consequences of central nervous system (CNS)-specific deletion of p53 and Pten, we observed a penetrant acute-onset malignant glioma phenotype with striking clinical, pathological, and molecular resemblance to primary GBM in humans. This primary, as opposed to secondary, GBM presentation in the mouse prompted genetic analysis of human primary GBM samples that revealed combined p53 and Pten mutations as the most common tumor suppressor defects in primary GBM. On the mechanistic level, the "multiforme" histopathological presentation and immature differentiation marker profile of the murine tumors motivated transcriptomic promoter-binding element and functional studies of neural stem cells (NSCs), which revealed that dual, but not singular, inactivation of p53 and Pten promotes cellular c-Myc activation. This increased c-Myc activity is associated not only with impaired differentiation, enhanced self-renewal capacity of NSCs, and tumor-initiating cells (TICs), but also with maintenance of TIC tumorigenic potential. Together, these murine studies have provided a highly faithful model of primary GBM, revealed a common tumor suppressor mutational pattern in human disease, and established c-Myc as a key component of p53 and Pten cooperative actions in the regulation of normal and malignant stem/progenitor cell differentiation, self-renewal, and tumorigenic potential.

Malignant solitary fibrous tumors of the head and neck: a clinicopathological study of nine consecutive patients

Malignant solitary fibrous tumor (MSFT) is one of the angiosarcomas arising from or resembling the components of blood vessels. Because of its rarity, the diagnosis is difficult. Between 1998 and 2008, 24 patients were diagnosed as having hemangiopericytomas (16) and solitary fibrous tumors (8). Nine of them were confirmed to be MSFT and treated at the Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine. All patients were treated with surgery as the primary modality. Eight patients received postoperative adjuvant radiation therapy. The average follow-up duration was 4.6 years (range: 6 months-10 years). Of the nine patients reviewed in this study, three died of locoregional or distant metastasis, six survived 6 months-6 years (four survived over 4 years). The size of primary tumor, the number of mitoses per 10 high powered fields and cervical lymph node metastasis seemed to be correlated with poor prognosis in MSFT patients, although the small number of patients did not permit the performance of statistical analysis.

Age-specific success rate for women undertaking their first assisted reproduction technology treatment using their own oocytes in Australia, 2002-2005

BACKGROUND

Woman's age is an independent factor determining the success of assisted reproductive technology treatment. This study presents the age-specific success rate of first autologous fresh treatment in Australia during 2002-2005.

METHODS

This is a retrospective population-based study of 36,412 initiated first autologous fresh cycles conducted in Australian clinics during 2002-2005. Pregnancy and live delivery rates per initiated cycle were determined for each age.

RESULTS

The overall live delivery rate per initiated cycle was 20.4% with the highest success rate in women aged between 22 and 36 years. Male factor only infertility had a higher live delivery rate (22.0%) than female factor only infertility (19.2%). Advancing woman's age was associated with a decline in success rate. For women > or = 30 years, each additional 1 year in age was associated with an 11% (99% CI: 10-12%) reduction in the chance of achieving pregnancy and a 13% (99% CI: 12-14%) reduction in the chance of a live delivery. If women aged 35 years or older would have had their first autologous fresh treatment 1 year earlier, 15% extra live deliveries would be expected.

CONCLUSIONS

This study suggested that women aged 35 years or older should be encouraged to seek early fertility assessment and treatment where clinically indicated.

Vibrational assignment and structure of dibenzoylmethane. A density functional theoretical study

Molecular structure and vibrational frequencies of 1,3-diphenyl-1,3-propanedione, known as dibenzoylmethane (DBM), have been investigated by means of density functional theory (DFT) calculations. The results were compared with those of benzoylacetone (BA) and acetylacetone (AA), the parent molecule. IR and Raman spectra of DBM and its deuterated analogue were clearly assigned. The calculated hydrogen bond energy of DBM is 16.15 kcal/mol, calculated at B3LYP/6-311++G** level of theory, which is 0.28 kcal/mol more than that of AA. This result is in agreement with the vibrational and NMR spectroscopy results. The molecular stability and the hydrogen bond strength were investigated by applying the Natural Bond Orbital analysis (NBO) and geometry calculations. The theoretical calculations indicate that the hydrogen bond in DBM is relatively stronger than that in BA and AA.

The combination of SKY and specific loci detection with FISH or immunostaining

Spectral karyotyping (SKY) represents an effective tool to detect individual chromosomes and analyze major karyotype abnormalities within an entire genome. We have tested the feasibility of combining SKY and FISH/protein detection in order to combine SKY's unique abilities with specific loci detection. Our experimental results demonstrate that various combined protocols involving SKY, FISH and immunostaining work well when proper procedures are used. This combined approach allows the tracking of key genes or targeted chromosome regions while monitoring changes throughout the whole genome. It is particularly useful when simultaneously monitoring the behavior of both protein complexes and DNA loci within the genome. The details of this methodology are described and systematically tested in this communication.

Photochemical instability of CdSe nanocrystals coated by hydrophilic thiols

The photochemical instability of CdSe nanocrystals coated by hydrophilic thiols was studied nondestructively and systematically in water. The results revealed that the photochemical instability of the nanocrystals actually included three distinguishable processes, namely the photocatalytic oxidation of the thiol ligands on the surface of nanocrystals, the photooxidation of the nanocrystals, and the precipitation of the nanocrystals. At first, the thiol ligands on the surface of a nanocrystal were gradually photocatalytically oxidized using the CdSe nanocrystal core as the photocatalyst. This photocatalytic oxidation process was observed as a zero-order reaction in terms of the concentration of the free thiols in the solution. The photogenerated holes in a nanocrystal were trapped onto the thiol ligands bound on the surface of the nanocrystal, which initiated the photooxidation of the ligands and protected the nanocrystal from any photooxidation. After nearly all of the thiol ligands on the surface of the nanocrystals were converted into disulfides, the system underwent several different pathways. If the disulfides were soluble in water, then all of the disulfides fell into the solution at the end of this initial process, and the nanocrystals precipitated out of the solution without much variation over their size and size distribution. When the disulfides were insoluble in water, they likely formed a micelle-like structure around the nanocrystal core and kept it soluble in the solution. In this case, the nanocrystals only precipitated after severe oxidation, which took a long period of time. If the system contained excess free thiol ligands, they replaced the photochemically generated disulfides and maintained the stability and solubility of the nanocrystals. The initiation stage of the photooxidation of CdSe nanocrystals themselves increased as the thickness and packing density of the ligand shell increased. This was explained by considering the ligand shell on the surface of a nanocrystal as the diffusion barrier of the oxygen species from the bulk solution into the interface between the nanocrystal and the surface ligands. Experimental results clearly indicated that the initiation stage of the photooxidation was not caused by the chemical oxidation of the system kept in air under dark conditions or the hydrolysis of the cadmium-thiol bonds on the surface of the nanocrystals, both of which were magnitudes slower than the photocatalytic oxidation of the surface ligands if they occurred at all. The results described in this contribution have already been applied for designing new types of thiol ligands which dramatically improved the photochemical stability of CdSe nanocrystals with a ligand shell that is as thin as approximately 1 nm.

Prediction of electronic excited states of adsorbates on metal surfaces from first principles

We present the first ab initio prediction of localized electronic excited states in a periodically infinite condensed phase, a heretofore intractable goal. In particular, we examined local excitations within a CO molecule adsorbed on Pd(111). The calculation allows a configuration interaction treatment of a local region, while its interaction with the extended condensed phase is described via an embedding potential obtained from periodic density functional theory. Our work lays the foundation of a microscopic understanding of photochemistry and spectroscopy on metal surfaces.

Meiotic telomere distribution and Sertoli cell nuclear architecture are altered in Atm- and Atm-p53-deficient mice

The ataxia telangiectasia mutant (ATM) protein is an intrinsic part of the cell cycle machinery that surveys genomic integrity and responses to genotoxic insult. Individuals with ataxia telangiectasia as well as Atm(-/-) mice are predisposed to cancer and are infertile due to spermatogenesis disruption during first meiotic prophase. Atm(-/-) spermatocytes frequently display aberrant synapsis and clustered telomeres (bouquet topology). Here, we used telomere fluorescent in situ hybridization and immunofluorescence (IF) staining of SCP3 and testes-specific histone H1 (H1t) to spermatocytes of Atm- and Atm-p53-deficient mice and investigated whether gonadal atrophy in Atm-null mice is associated with stalling of telomere motility in meiotic prophase. SCP3-H1t IF revealed that most Atm(-/-) p53(-/-) spermatocytes degenerated during late zygotene, while a few progressed to pachytene and diplotene and some even beyond metaphase II, as indicated by the presence of a few round spermatids. In Atm(-/-) p53(-/-) meiosis, the frequency of spermatocytes I with bouquet topology was elevated 72-fold. Bouquet spermatocytes with clustered telomeres were generally void of H1t signals, while mid-late pachytene and diplotene Atm(-/-) p53(-/-) spermatocytes displayed expression of H1t and showed telomeres dispersed over the nuclear periphery. Thus, it appears that meiotic telomere movements occur independently of ATM signaling. Atm inactivation more likely leads to accumulation of spermatocytes I with bouquet topology by slowing progression through initial stages of first meiotic prophase and an ensuing arrest and demise of spermatocytes I. Sertoli cells (SECs), which contribute to faithful spermatogenesis, in the Atm mutants were found to frequently display numerous heterochromatin and telomere clusters-a nuclear topology which resembles that of immature SECs. However, Atm(-/-) SECs exhibited a mature vimentin and cytokeratin 8 intermediate filament expression signature. Upon IF with ATM antibodies, we observed ATM signals throughout the nuclei of human and mouse SECs, spermatocytes I, and haploid round spermatids. ATM but not H1t was absent from elongating spermatid nuclei. Thus, ATM appears to be removed from spermatid nuclei prior to the occurrence of DNA nicks which emanate as a consequence of nucleoprotamine formation.

Localization of putative stem cells in dental epithelium and their association with Notch and FGF signaling

The continuously growing mouse incisor is an excellent model to analyze the mechanisms for stem cell lineage. We designed an organ culture method for the apical end of the incisor and analyzed the epithelial cell lineage by 5-bromo-2'-deoxyuridine and DiI labeling. Our results indicate that stem cells reside in the cervical loop epithelium consisting of a central core of stellate reticulum cells surrounded by a layer of basal epithelial cells, and that they give rise to transit-amplifying progeny differentiating into enamel forming ameloblasts. We identified slowly dividing cells among the Notch1-expressing stellate reticulum cells in specific locations near the basal epithelial cells expressing lunatic fringe, a secretory molecule modulating Notch signaling. It is known from tissue recombination studies that in the mouse incisor the mesenchyme regulates the continuous growth of epithelium. Expression of Fgf-3 and Fgf-10 were restricted to the mesenchyme underlying the basal epithelial cells and the transit-amplifying cells expressing their receptors Fgfr1b and Fgfr2b. When FGF-10 protein was applied with beads on the cultured cervical loop epithelium it stimulated cell proliferation as well as expression of lunatic fringe. We present a model in which FGF signaling from the mesenchyme regulates the Notch pathway in dental epithelial stem cells via stimulation of lunatic fringe expression and, thereby, has a central role in coupling the mitogenesis and fate decision of stem cells.

Loss of p21 increases sensitivity to ionizing radiation and delays the onset of lymphoma in atm-deficient mice

Ataxia telangiectasia (AT) is an autosomal recessive disorder characterized by growth retardation, cerebellar ataxia, oculocutaneous telangiectasias, and a high incidence of lymphomas and leukemias. In addition, AT patients are sensitive to ionizing radiation. Atm-deficient mice recapitulate most of the AT phenotype. p21(cip1/waf1 )(p21 hereafter), an inhibitor of cyclin-dependent kinases, has been implicated in cellular senescence and response to gamma-radiation-induced DNA damage. To study the role of p21 in ATM-mediated signal transduction pathways, we examined the combined effect of the genetic loss of atm and p21 on growth control, radiation sensitivity, and tumorigenesis. As might have been expected, our data provide evidence that p21 modifies the in vitro senescent response seen in AT fibroblasts. Further, it is a downstream effector of ATM-mediated growth control. In addition, however, we find that loss of p21 in the context of an atm-deficient mouse leads to a delay in thymic lymphomagenesis and an increase in acute radiation sensitivity in vivo (the latter principally because of effects on the gut epithelium). Modification of these two crucial aspects of the ATM phenotype can be related to an apparent increase in spontaneous apoptosis seen in tumor cells and in the irradiated intestinal epithelium of mice doubly null for atm and p21. Thus, loss of p21 seems to contribute to tumor suppression by a mechanism that operates via a sensitized apoptotic response. These results have implications for cancer therapy in general and AT patients in particular.

Expression and secretion of preS containing hepatitis B surface antigen in vaccinia virus system

The expression and secretion of preS containing hepatitis B surface antigen in vaccinia virus system was investigated. The human TK- 143 cells were infected with the recombinant vaccinia viruses vTMS-1 or vTLS-1. Cells infected with vTMS-1, which contains the preS2 + S gene, produced preS2 containing middle HBsAg proteins. Similarly, cells produced preS1 containing large HBsAg proteins upon infection with vTLS-1, which carries the preS1 + preS2 + S gene. The expression products could be secreted and form 22 nm particles. They reacted specifically with anti-preS1 and/or anti-preS2 monoclonal antibodies, and exhibited pHSA-receptor (for polymerized human serum albumin) activity. In addition, the major S components of hepatitis B surface antigen were also present in the products expressed by vTMS-1 and vTLS-1.

Isolated colonic tuberculosis

Two cases of isolated colonic tuberculosis are reported, and recent literature on this field is reviewed. Isolated colonic tuberculosis is defined as a tuberculosis which exists in the colon except for ileocaecum, without focus in any other organ. The morphological changes are tuberculous granulation primarily located to the submucosa layer of the colon with smooth surfaces of both mucous and serous membrane. Its clinical features are atypical, just like those on X-ray examination, and even on frozen biopsy, it may sometimes be misdiagnosed. The treatment of choice is resecting the diseased segment of colon combined with anti-tuberculosis therapy.