Measurement of the transverse electric field profile of light by a self-referencing method with direct phase determination

We present a method for measuring the transverse electric field profile of a beam of light which allows for direct phase retrieval. The measured values correspond, within a normalization constant, to the real and imaginary parts of the electric field in a plane normal to the direction of propagation. This technique represents a self-referencing method for probing the wavefront characteristics of light.

The feasibility and acceptability of muscle biopsy in epidemiological studies: findings from the Hertfordshire Sarcopenia Study (HSS)

BACKGROUND

Sarcopenia, the loss of muscle mass and strength, is associated adversely with disability, morbidity and mortality. Epidemiological findings suggest influences operating across the life course may be important. Our aim was to ascertain the feasibility and acceptability of obtaining muscle tissue from healthy older people in order to ultimately identify cellular mechanisms underlying life course influences on sarcopenia.

METHODS

105 men with documented birth weight consented to detailed assessment of muscle mass and strength, and a biopsy of the vastus lateralis using the Weil-Blakesley conchotome. Acceptability was ascertained by questionnaire and a 100 mm pain Visual Analogue Scale (VAS). 100 mm indicated severe pain.

RESULTS

Muscle biopsy was successfully carried out in 102 out of 105 participants, mean yield 107 mg (range 20-290 mg). There were no serious wound complications. Ninety-three participants completed feedback questionnaires. The median pain VAS score during the procedure was 7 mm (Interquartile range [IQR] 1-34), 4 mm (IQR 0-16) one day after the procedure and 1mm (IQR 0-4) 7 days after the procedure. 60 (65%) participants were back to their normal levels of activity one day after the procedure. 85 (91%) found this procedure acceptable and would have the procedure again.

CONCLUSION

Muscle biopsy using a Weil-Blakesley conchotome is both feasible and acceptable in community dwelling older men participating in epidemiological research. The excellent yield of biopsy tissue will allow morphological and molecular studies of muscle to be integrated into an epidemiological study facilitating investigation of the mechanisms underpinning sarcopenia that could potentially be altered by life course influences.

Driver mutations in TP53 are ubiquitous in high grade serous carcinoma of the ovary

Numerous studies have tested the association between TP53 mutations in ovarian cancer and prognosis but these have been consistently confounded by limitations in study design, methodology, and/or heterogeneity in the sample cohort. High-grade serous (HGS) carcinoma is the most clinically important histological subtype of ovarian cancer. As these tumours may arise from the ovary, Fallopian tube or peritoneum, they are collectively referred to as high-grade pelvic serous carcinoma (HGPSC). To identify the true prevalence of TP53 mutations in HGPSC, we sequenced exons 2-11 and intron-exon boundaries in tumour DNA from 145 patients. HGPSC cases were defined as having histological grade 2 or 3 and FIGO stage III or IV. Surprisingly, pathogenic TP53 mutations were identified in 96.7% (n = 119/123) of HGPSC cases. Molecular and pathological review of mutation-negative cases showed evidence of p53 dysfunction associated with copy number gain of MDM2 or MDM4, or indicated the exclusion of samples as being low-grade serous tumours or carcinoma of uncertain primary site. Overall, p53 dysfunction rate approached 100% of confirmed HGPSCs. No association between TP53 mutation and progression-free or overall survival was found. From this first comprehensive mapping of TP53 mutation rate in a homogeneous group of HGPSC patients, we conclude that mutant TP53 is a driver mutation in the pathogenesis of HGPSC cancers. Because TP53 mutation is almost invariably present in HGPSC, it is not of substantial prognostic or predictive significance.

Driver mutations in TP53 are ubiquitous in high grade serous carcinoma of the ovary

Numerous studies have tested the association between TP53 mutations in ovarian cancer and prognosis but these have been consistently confounded by limitations in study design, methodology, and/or heterogeneity in the sample cohort. High-grade serous (HGS) carcinoma is the most clinically important histological subtype of ovarian cancer. As these tumours may arise from the ovary, Fallopian tube or peritoneum, they are collectively referred to as high-grade pelvic serous carcinoma (HGPSC). To identify the true prevalence of TP53 mutations in HGPSC, we sequenced exons 2-11 and intron-exon boundaries in tumour DNA from 145 patients. HGPSC cases were defined as having histological grade 2 or 3 and FIGO stage III or IV. Surprisingly, pathogenic TP53 mutations were identified in 96.7% (n = 119/123) of HGPSC cases. Molecular and pathological review of mutation-negative cases showed evidence of p53 dysfunction associated with copy number gain of MDM2 or MDM4, or indicated the exclusion of samples as being low-grade serous tumours or carcinoma of uncertain primary site. Overall, p53 dysfunction rate approached 100% of confirmed HGPSCs. No association between TP53 mutation and progression-free or overall survival was found. From this first comprehensive mapping of TP53 mutation rate in a homogeneous group of HGPSC patients, we conclude that mutant TP53 is a driver mutation in the pathogenesis of HGPSC cancers. Because TP53 mutation is almost invariably present in HGPSC, it is not of substantial prognostic or predictive significance.

Driver mutations in TP53 are ubiquitous in high grade serous carcinoma of the ovary

Numerous studies have tested the association between TP53 mutations in ovarian cancer and prognosis but these have been consistently confounded by limitations in study design, methodology, and/or heterogeneity in the sample cohort. High-grade serous (HGS) carcinoma is the most clinically important histological subtype of ovarian cancer. As these tumours may arise from the ovary, Fallopian tube or peritoneum, they are collectively referred to as high-grade pelvic serous carcinoma (HGPSC). To identify the true prevalence of TP53 mutations in HGPSC, we sequenced exons 2-11 and intron-exon boundaries in tumour DNA from 145 patients. HGPSC cases were defined as having histological grade 2 or 3 and FIGO stage III or IV. Surprisingly, pathogenic TP53 mutations were identified in 96.7% (n = 119/123) of HGPSC cases. Molecular and pathological review of mutation-negative cases showed evidence of p53 dysfunction associated with copy number gain of MDM2 or MDM4, or indicated the exclusion of samples as being low-grade serous tumours or carcinoma of uncertain primary site. Overall, p53 dysfunction rate approached 100% of confirmed HGPSCs. No association between TP53 mutation and progression-free or overall survival was found. From this first comprehensive mapping of TP53 mutation rate in a homogeneous group of HGPSC patients, we conclude that mutant TP53 is a driver mutation in the pathogenesis of HGPSC cancers. Because TP53 mutation is almost invariably present in HGPSC, it is not of substantial prognostic or predictive significance.

Improvement in out-of-hours outcomes following the implementation of Hospital at Night

BACKGROUND

Hospital at Night (H@N) is a Department of Health (England) driven programme being widely implemented across UK. It aims to redefine how medical cover is provided in hospitals during the out-of-hours period.

AIM

To investigate whether the implementation of H@N is associated with significant change in system or clinical outcomes.

DESIGN

An observational study for 14 consecutive nights before, and 14 consecutive nights after the implementation of H@N. Data were collected from the Combined surgical and medical Assessment Unit (CAU), the 18 medical/surgical wards (The Ward Arc) and the four High Dependency Units (The Critical Care corridor) within the Royal Infirmary of Edinburgh.

METHODS

Following an overnight episode of clinical concern, data were gathered on response time, seniority of reviewing staff, patient outcome and the use of Standardized Early Warning Score (SEWS).

RESULTS

Two hundred and nine episodes of clinical concern were recorded before the implementation of H@N and 216 episodes afterwards. There was no significant change in response time in the CAU, Ward Arc or Critical Care corridor. However, significant inter-speciality differences in response time were eradicated, particularly in the Critical Care corridor. Following the implementation of H@N, patients were reviewed more frequently by senior medical staff in CAU (28% vs. 4%, P < 0.05) and the Critical Care corridor (50% vs. 22%, P < 0.001). Finally there was a reduction in adverse outcome (defined as unplanned transfer to critical care/cardiac arrest) in the Ward Arc and CAU from 17% to 6% of patients reviewed overnight (P < 0.01). SEWS was more frequently and accurately recorded in CAU.

CONCLUSION

This is the first study that we are aware of directly comparing out-of-hours performance before and after the implementation of H@N. Significant improvements in both patient and system outcomes were observed, with no adverse effects noted.

Intrathecal ziconotide and opioid combination therapy for noncancer pain: an observational study

BACKGROUND

Intrathecal ziconotide is used to manage severe chronic pain. Although ziconotide is approved by the US Food and Drug Administration for monotherapy, it is sometimes used in combination with other intrathecal drugs for the management of intractable pain conditions in clinical practice.

OBJECTIVES

Evaluate the safety and tolerability of ziconotide combination therapy.

STUDY DESIGN

A retrospective, observational study.

SETTING

A single center.

METHODS

Patients with severe chronic pain of noncancer origin who were receiving inadequate analgesia with intrathecal opioid therapy (with or without intrathecal adjuvants) and who had ziconotide added to their intrathecal regimens were included. Patient characteristics, intrathecal ziconotide doses, concomitant intrathecal and systemic drug use, visual analog scale pain scores, Oswestry Disability Index scores, mini-mental status examination scores, neurological examination results, clinical observations (including adverse event reports), and equipment complications were reviewed for 12 weeks after ziconotide initiation.

RESULTS

Sixteen patients were identified. Ziconotide was initiated at a dose of 0.5 mcg/d and titrated to a mean dose of 2.64 mcg/d at week 12. Intrathecal opioids were hydromorphone (n=7), morphine (n=5), fentanyl (n=3), and sufentanil (n=1). Adverse events were noted in one patient, who reported increased depression and pain during combination therapy; ziconotide treatment was discontinued, and all adverse events resolved over a 4-week period. Substantial pain relief (> or =4-point decrease in visual analog scale score) was reported in 3 of 15 patients (20.0%) and increased functional capacity was evident in 3 of 15 patients (20.0%).

LIMITATIONS

A retrospective study with a limited number of patients from a single center.

CONCLUSION

Results from this observational study suggest that combination intrathecal ziconotide and opioid therapy may be a safe and potentially effective treatment option for patients with refractory chronic pain. Controlled, prospective clinical trials to evaluate ziconotide combination therapy are needed.

Population-based detection of Lynch syndrome in young colorectal cancer patients using microsatellite instability as the initial test

Approximately 1-2% of colorectal cancers (CRC) arise because of germline mutations in DNA mismatch repair genes, referred to as Lynch syndrome. These tumours show microsatellite instability (MSI) and loss of expression of mismatch repair proteins. Pre-symptomatic identification of mutation carriers has been demonstrated to improve survival; however, there is concern that many are not being identified using current practices. We evaluated population-based MSI screening of CRC in young patients as a means of ascertaining mutation carriers. CRC diagnosed in patients aged <60 years were identified from pathology records. No prior information was available on family history of cancer. PCR techniques were used to determine MSI in the BAT-26 mononucleotide repeat and mutation in the BRAF oncogene. Loss of MLH1, MSH2, MSH6 and PMS2 protein expression was evaluated in MSI+ tumours by immunohistochemistry. MSI+ tumours were found in 105/1,344 (7.8%) patients, of which 7 were excluded as possible Lynch syndrome because of BRAF mutation. Of the 98 "red flag" cases that were followed up, 25 were already known as mutation carriers or members of mutation carrier families. Germline test results were obtained for 35 patients and revealed that 22 showed no apparent mutation, 11 showed likely pathogenic mutations and 2 had unclassified variants. The proportion of MSI+ cases in different age groups that were estimated to be mutation carriers was 89% (<30 years), 83% (30-39), 68% (40-49) and 17% (50-59). We recommend MSI as the initial test for population-based screening of Lynch syndrome in younger CRC patients, regardless of family history.

Endoscopic ultrasound guided fine needle aspiration of solid pancreatic lesions: Performance and outcomes

BACKGROUND AND AIM

We report our single-centre experience with endoscopic ultrasound guided fine needle aspiration (EUS-FNA) of solid pancreatic lesions with regard to clinical utility, diagnostic accuracy and safety.

METHODS

We prospectively reviewed data on 100 consecutive EUS-FNA procedures performed in 93 patients (54 men, mean age 60.6 +/- 12.9 years) for evaluation of solid pancreatic lesions. Final diagnosis was based on a composite standard: histologic evidence at surgery, or non-equivocal malignant cytology on FNA and follow-up. The operating characteristics of EUS-FNA were determined.

RESULTS

The location of the lesions was pancreatic head in 73% of cases, the body in 20% and the tail in 7%. Mean lesion size was 35.1 +/- 12.9 mm. The final diagnosis revealed malignancy in 87 cases, including adenocarcinomas (80.5%), neuroendocrine tumours (11.5%), lymphomas (3.4%) and other types (4.6%). The FNA findings were: 82% interpreted as malignant cytology, 1% as suspicious for neoplasia, 1% as atypical, 7% as benign process and 9% as non-diagnostic. No false-positive results were observed. There was a false-negative rate of 5%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 94.3%, 100%, 100%, 72.2% and 95%, respectively. In 23 (88.5%) of 26 aspirated lymph nodes malignancy was found. Minor complications occurred in two patients.

CONCLUSIONS

Our experience confirms that EUS-FNA in patients with suspected solid pancreatic lesions is safe and has a high diagnostic accuracy. This technique should be considered the preferred test when a cytological diagnosis of a pancreatic mass lesion is required.

Skeletal and Cardiac Muscle Defects in a Murine Model of Emery-Dreifuss Muscular Dystrophy

Previous histological findings, physiological data, and behavioral observations on the A-type lamin knockout mouse (Lmna(-/-)) suggest that important aspects of this model resemble the human Emery-Dreifuss muscular dystrophy (EDMD) phenotype. The main goal of our experiments was to study skeletal and cardiac muscle function in this murine model to obtain the semiquantitative data needed for more detailed comparisons with human EDMD defects. Measurements of the mechanical properties of preparations from two different skeletal muscle groups, the soleus and the diaphragm, were made in vitro. In addition, records of the electrocardiogram, and measurements of heart rate variability were obtained; and phasic contractions (unloaded shortening) of enzymatically isolated ventricular myocytes were monitored. Soleus muscles from Lmna(-/-) mice produced less force and work than control preparations. In contrast, force and work production in strips of diaphragm were not changed significantly. Lead II electrocardiograms from conscious, restrained Lmna(-/-) mice revealed slightly decreased heart rates, with significant prolongations of PQ, QRS, and 'QT' intervals compared with those from control recordings. These ECG changes resemble some aspects of the ECG records from humans with EDMD; however, the cardiac phenotype in this Lmna(-/-) mouse model appears to be less well-defined/developed. Ventricular myocytes isolated from Lmna(-/-) mice exhibited impaired contractile responses, particularly when superfused with the beta-adrenergic agonist, isoproterenol (1 microM). This deficit was more pronounced in myocytes isolated from the left ventricle(s) than in myocytes from the right ventricle(s). In summary, tissues from the Lmna(-/-) mouse exhibit a number of skeletal and cardiac muscle deficiencies, some of which are similar to those which have been reported in studies of human EDMD.