Intermediate stages of surface state formation and collapse of topological protection to transport in Bi2Se3

Surface states consisting of helical Dirac fermions have been extensively studied in three-dimensional topological insulators. Yet, experiments to date have only investigated fully formed topological surface states (TSS) and it is not known whether preformed or partially formed surface states can exist or what properties they could potentially host. Here, by decorating thin films of Bi₂Se₃ with nanosized islands of the same material, we show for the first time that not only can surface states exist in various intermediate stages of formation but they exhibit unique properties not accessible in fully formed TSS. These include tunability of the Dirac cone mass, vertical migration of the surface state wave-function and the appearance of mid-gap Rashba-like states as exemplified by our theoretical model for decorated TIs. Our experiments show that an interplay of Rashba and Dirac fermions on the surface leads to an intriguing multi-channel weak anti-localization effect concomitant with an unprecedented tuning of the topological protection to transport. Our work offers a new route to engineer topological surface states involving Dirac-Rashba coupling by nano-scale decoration of TI thin films, at the same time shedding light on the real-space mechanism of surface state formation in general.

Sentinel lymph node status in vulval cancer: systematic reviews of test accuracy and decision-analytic model-based economic evaluation

BACKGROUND

Vulval cancer causes 3-5% of all gynaecological malignancies and requires surgical removal and inguinofemoral lymphadenectomy (IFL). Complications affect > 50% of patients, including groin wound infection, lymphoedema and cellulitis. A sentinel lymph node (SLN) is the first groin node with the highest probability of malignancy. SLN biopsy would be useful if it could accurately identify patients in whom cancer has spread to the groin, without removing all groin nodes. SLNs can be identified by isosulfan blue dye and/or technetium-99 ((99m)Tc) radioactive tracer during lymphoscintigraphy. The blue dye/(99m)Tc procedure only detects SLN, not metastases - this requires histological examination, which can include ultrastaging and staining with conventional haematoxylin and eosin (H&E) or immunohistochemistry.

OBJECTIVES

To determine the test accuracy and cost-effectiveness of the SLN biopsy with (99m)Tc and/or blue dye compared with IFL or clinical follow-up for test negatives in vulval cancer, through systematic reviews and economic evaluation.

DATA SOURCES

Standard medical databases, including MEDLINE, EMBASE, Science Citation Index and The Cochrane Library, medical search gateways, reference lists of review articles and included studies were searched to January 2011.

METHODS

For accuracy and effectiveness, standard methods were used and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Searches were to January 2011, with no language restrictions. Meta-analyses were carried out with Meta-Disc version 1.4 (Javier Zamora, Madrid, Spain) for accuracy; none was appropriate for effectiveness. The economic evaluation from a NHS perspective used a decision-tree model in DATA TreeAge Pro Healthcare 2001 (TreeAge Software, Inc., Williamstown, MA, USA). Six options (blue dye with H&E, blue dye with ultrastaging, (99m)Tc with H&E, (99m)Tc with ultrastaging, blue dye/(99m)Tc with H&E, blue dye/(99m)Tc with ultrastaging) were compared with IFL. Deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

For accuracy, of the 26 included studies, most evaluated (99m)Tc/blue dye combined. Four studies had clinical follow-up only for test negatives and five had clinical follow-up for all and IFL for test negatives. Numbers with no SLN found were difficult to distinguish from those with negative SLN biopsies. The largest group of 11 studies using (99m)Tc/blue dye, ultrastaging and immunohistochemistry had a pooled sensitivity of 95.6% [95% confidence interval (CI) 91.5% to 98.1%] and a specificity of 100% (95% CI 99.0% to 100%). Mean SLN detection rates were 94.6% for (99m)Tc, 68.7% for blue dye and 97.7% for both. One study measured global health status quality of life (QoL) and found no difference between SLN biopsy and IFL. One patient preference evaluation showed that 66% preferred IFL rather than a 5% false-negative rate from SLN biopsy. For effectiveness, of 14,038 references, one randomised controlled trial, three case-control studies and 13 case series were found. Approximately 50% died from vulval cancer and 50% from other causes during follow-ups. Recurrences were in the ratio of approximately 4 : 2 : 1 vulval, groin and distant, with more recurrences in node-positive patients. No studies reported QoL. For cost per death averted, IFL was less costly and more effective than strategies using SLN biopsy. For morbidity-free survival and long-term morbidity-free survival, (99m)Tc with ultrastaging was most cost-effective. Strategies with blue dye only and H&E only were never cost-effective. The incremental cost-effectiveness ratio for (99m)Tc with ultrastaging compared with IFL was £4300 per case of morbidity-free survival and £7100 per long-term morbidity-free survival.

LIMITATIONS

The main limitations of this study include the lack of good-quality evidence on accuracy, effectiveness and QoL. A large project such as this takes time to publish, so the most recent studies are not included.

CONCLUSIONS

A sensitive and specific combined metastatic SLN detection test and information on generic QoL in vulval cancer is urgently required.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Sentinel lymph node biopsy in vulval cancer: systematic review and meta-analysis

BACKGROUND

The purpose of this study was to determine the accuracy of sentinel lymph node (SLN) biopsy with technetium 99 (99mTc) and/or blue dye-enhanced lymphoscintigraphy in vulval cancer.

METHODS

Sensitive searches of databases were performed upto October 2013. Studies with at least 75% of women with FIGO stage IB or II vulval cancer evaluating SLN biopsy with 99mTc, blue dye or both with reference standard of inguinofemoral lymphadenectomy (IFL) or clinical follow-up were included. Meta-analyses were performed using Meta-Disc version 1.4.

RESULTS

Of the 2950 references, 29 studies (1779 women) were included; most of them evaluated 99mTc combined with blue dye. Of these, 24 studies reported results for SLN followed by IFL, and 5 reported clinical follow-up only for SLN negatives. Pooling of all studies was inappropriate because of heterogeneity. Mean SLN detection rates were 94.0% for 99mTc, 68.7% for blue dye and 97.7% for both. SLN biopsy had pooled sensitivity of 95% (95% CI 92-98%) with negative predictive value (NPV) of 97.9% in studies using 99mTc/blue dye, ultrastaging and immunohistochemistry with IFL as reference. Pooled sensitivity for SLN with clinical follow-up for SLN-negatives was 91% (85-95%) with NPV 95.6%. Patients undergoing SLN biopsy experienced less morbidity than those undergoing IFL.

CONCLUSIONS

Sentinel lymph node biopsy using 99mTC, blue dye and ultrastaging with immunohistochemistry is highly accurate when restricted to carefully selected patients, within a rigorous protocol, with close follow-up and where sufficient numbers for learning curve optimisation exist. Patients must make an informed choice between the slightly higher groin recurrence rates of SLN biopsy vs the greater morbidity of IFL.

Anamolous course of right common carotid artery in a case of papillary carcinoma thyroid

Anamolous Course of Carotid Artery is one of the rarest of the rare anamoly, we describe one such case of anamolous Course of Right Common Carotid Artery.

Degradation studies of organic acids in commercially packed fruit juices: A reverse phase high performance liquid chromatographic approach

Organic acids are important constituents of fruit juices. They render tartness, flavour and specific taste to fruit juices. Shelf life and stability of fruit juices are important factors, which determine their nutritional quality and freshness. In this view, the effect of storage on the concentration of organic acids in commercially packed fruit juices is studied by reverse phase high performance liquid chromatography (RP-HPLC). Ten packed fruit juices from two different brands are stored at 30°C for 24, 48 and 72 hours. A reverse phase high performance liquid chromatographic method is used to determine the concentration of oxalic, tartaric, malic, ascorbic and citric acid in the fruit juices during storage. The chromatographic analysis of organic acids is carried out using mobile phase 0.5% (w/v) ammonium dihydrogen orthophosphate buffer (pH 2.8) on C18 column with UV-Vis detector. The results show that the concentration of organic acids generally decreases in juices under study with the increase in storage time. All the fruit juices belonging to tropicana brand underwent less organic acid degradation in comparison to juices of real brand. Orange fruit juice is found to be least stable among the juices under study, after the span of 72 hours. Amongst all the organic acids under investigation minimum stability is shown by ascorbic acid followed by malic and citric acid.

Congenital adrenal hyperplasia masquerading as periodic paralysis in an adolescent girl

Congenital adrenal hyperplasia is an uncommon diagnosis in routine clinical practice. 21-hydroxylase deficiency, which is its most common subtype, may be diagnosed at birth in a female infant by virilisation or by features of salt wasting in both genders. However, other uncommon subtypes of this condition such as 17-alpha-hydroxylase deficiency, 11-beta-hydroxylase deficiency may present much later in adolescence or adulthood. A high index of suspicion is necessary when evaluating children with hypertension, hypokalaemia, metabolic alkalosis or sexual infantilism.

Role of rigidity and temperature in the kinetics of photodarkening in Ge(x)As(45-x)Se55 thin films

We present insightful results on the kinetics of photodarkening (PD) in Ge(x)As(45-x)Se55 glasses at the ambient and liquid helium temperatures when the network rigidity is increased by varying x from 0 to 16. We observe a many fold change in PD and its kinetics with decreasing network flexibility and temperature. Moreover, temporal evolution of PD shows a dramatic change with increasing x.

Differential trends in the rising incidence of endometrial cancer by type: data from a UK population-based registry from 1994 to 2006

Background:

Endometrial cancer is the most common gynaecological cancer in the western world, the incidence increasing in the United Kingdom by over 40% since 1993. Two types of endometrial cancer exist – oestrogen-dependent type 1 with good prognosis and non-oestrogen-dependent type 2 with poor prognosis. The histopathological distribution of the increase in endometrial cancer is unknown. This study investigates the observed incidence trends of the two types, the age, stage, and socioeconomic distribution of this increase and survival outcome.

Methods:

Data were analysed from 6867 women with endometrial cancer registered between 1994 and 2006, at a UK population-based cancer registry.

Results:

Increased endometrial cancer incidence is confined to type 1 cancers with a significant increase in age standardised incidence rate (ASR) from 12.0 per 100 000 (confidence interval (CI) 10.7–13.2) in 1994 to 16.3 per 100 000 (CI 14.9–17.7), P<0.001 in 2006, while ASR of type 2 cancer changed from 2.5 per 100 000 (CI 2.0–3.1) in 1994 to 2.2 per 100 000 (CI 1.7–2.7) in 2006, which was not statistically significant P>0.05. Increase in type 1 cancer is most marked in age groups 60–69 years (P<0.001) and 70–79 years (P<0.001) and distributed equally among socioeconomic quintiles. While outcome for type 1 cancer has improved, 1-year survival in type 2 cancer is unchanged from 73.1% in 1994 to 74.3%, P=0.089 and 5-year survival decreased from 55.1% to 40.9%, P=0.001.

Conclusion:

Increased incidence in endometrial cancer is confined to type 1 cancers, seen most in the 60–79 age groups and across all socioeconomic quintiles. Survival in type 2 cancer has decreased significantly. Urgent research is needed to investigate prevention strategies in type 1 and improve therapy in type 2 cancers.

Carboplatin, ifosfamide, and mesna (CIM) for the treatment of gynecological carcinosarcoma

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Background: A GOG trial comparing cisplatin/ifosfamide/mesna chemotherapy versus whole abdominal irradiation for FIGO stages I-IV carcinosarcoma (CS) showed an estimated median survival (MS) of 50 months for chemotherapy but high toxicity. This study investigates the efficacy and tolerability of a novel regimen using carboplatin AUC 5, ifosfamide 3 g/m2 and mesna 1 g/m2 (CIM) in both the adjuvant and metastatic setting. Methods: Retrospective analysis of women with CS treated from May 1997-May 2007 with CIM (group 1) versus other chemotherapy regimens (group 2). Toxicity was graded according to the Common Toxicity Criteria and MS estimated using the Kaplan-Meier method. Results: Of 51 eligible women (median age 71 years) 35 (69%) had stage 3 or 4 disease. 35/51 (69%) received chemotherapy; 2 with stage 1c disease received pelvic radiotherapy (pRT) alone whilst the remaining 14 were unfit for any treatment. Median follow-up for the treated patients is 45 months. 11/35 patients (31%) received CIM as first-line chemotherapy. Other regimens included: carboplatin (n = 14); carboplatin/paclitaxel (n = 3); carboplatin/epirubicin (n = 3); carboplatin/doxorubicin (n = 2); doxorubicin/ifosfamide (n = 1); cisplatin/ifosfamide (n = 1). 20/35 (57%) received adjuvant chemotherapy (AC) of which 8 received CIM; 11/20 patients also received adjuvant pRT. MS in the CIM AC group is 54.7 months compared to 37.4 months for other regimens. 3/8 patients (37.5%) in the CIM arm developed recurrent disease compared to 9/12 (75%) for other regimens. 4/16 patients received CIM as first- or second-line palliative chemotherapy. All patients responded of whom 2 achieved clinical and radiological complete response (CR). One woman subsequently relapsed and achieved a second CR with CIM. MS for all chemotherapy-treated patients is 54.7 months (group 1) versus 20.6 months (group 2) (p = 0.07). No patients in group 1 experienced any grade 3/4 toxicity and all patients completed the prescribed treatment. There were 2 unexpected treatment-related deaths in group 2, one of whom received carboplatin/paclitaxel and the other carboplatin/epirubicin. Conclusions: CIM appears to be efficacious and well tolerated in the treatment of CS and merits further investigation in clinical trials.

No significant financial relationships to disclose.

Diffusely Infiltrating Endometrial Carcinomas With No Stromal Response: Report of a Series, Including Cases With Cervical and Ovarian Involvement and Emphasis on the Potential for Misdiagnosis

Endometrial carcinomas, particularly of endometrioid type, can invade the myometrium or cervix without eliciting a stromal desmoplastic or inflammatory response and have been referred to as diffusely infiltrating endometrial carcinomas. This study describes a series of 14 endometrial carcinomas infiltrating as single “naked” glands without a stromal response. The neoplasms consisted of 12 endometrioid carcinomas, 1 mixed endometrioid and clear cell carcinoma, and 1 serous carcinoma. In all cases, there was myometrial invasion without stromal response. Seven cases exhibited cervical stromal involvement and in 2 there was involvement of both ovaries in a similar pattern. Several of the cases were seen in consultation and the pattern of infiltration raised a number of differential diagnoses, both benign and malignant, depending on the site of tumor involvement, including adenomyosis, adenomyoma, primary endocervical glandular lesions, cervical mesonephric remnants, endometriosis or tuboendometrioid metaplasia, and ovarian cortical inclusion cysts. Although this pattern of invasion has been reported previously, it continues to present diagnostic difficulties.