Response of large area avalanche photodiodes to low energy x rays

For an experiment to study neutron radiative beta-decay, we operated large area avalanche photodiodes (APDs) near liquid nitrogen temperature to detect x rays with energies between 0.2 keV and 20 keV. Whereas there are numerous reports of x ray spectrometry using APDs at energies above 1 keV, operation near liquid nitrogen temperature allowed us to reach a nominal threshold of 0.1 keV. However, due to the short penetration depth of x rays below 1 keV, the pulse height spectrum of the APD become complex. We studied the response using monochromatic x ray beams and employed phenomenological fits of the pulse height spectrum to model the measurement of a continuum spectrum from a synchrotron. In addition, the measured pulse height spectrum was modelled using a profile for the variation in efficiency of collection of photoelectrons with depth into the APD. The best results are obtained with the collection efficiency model.

18F-fluorodeoxyglucose positron emission tomography/computed tomography in the assessment of occult primary head and neck cancers--an audit and review of published studies

AIMS

To assess the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with squamous cell and undifferentiated cancer neck nodes and no primary site on conventional assessment.

MATERIALS AND METHODS

Seventy-eight patients with neck nodal metastases from an unknown primary cancer were studied. PET/CT was carried out in all patients, 1h after FDG injection.

RESULTS

Uptake suspicious of an occult primary cancer was found in 46/78 (59.0%) patients. Subsequent investigations confirmed a primary site in the base of the tongue in 14, pharyngeal palatine tonsil in 14, post cricoid in one, lung in one. PET/CT diagnosed primary cancers in 30/78 patients (38.5%); sensitivity, specificity, positive predictive value, negative predictive value: 30/30 (100.0%), 32/48 (66.7%), 30/46 (65.2%), 32/32 (100.0%), respectively. PET/CT detected additional disease in four patients: contralateral nodal disease in two, mediastinal nodal disease in one and liver metastases in one.

CONCLUSIONS

FDG PET/CT is of value in the assessment of patients with occult head and neck primary cancers. However, false-positive results remain a limitation of the investigation.

P2-13-03: Comparative Assessment of 636 Women at Risk for Hereditary Breast Cancer within 3 Public Hospitals: The Consortium of Underserved BRCA Testers

Background: Underserved women at risk for Hereditary Breast and Ovarian Cancer (HBOC) are confronted with many unique challenges, such as barriers to accessing appropriate genetic testing and counseling services and decreased resources, that place them at increased cancer risk. It is unclear whether these high-risk women are appropriately referred for genetic counseling and what their genetic test results demonstrate due to minimal practice-based evidence. To study this population, and to establish an infrastructure to further explore long-term outcomes, we formed the Consortium of Underserved BRCA testers in October 2010 from: San Francisco General Hospital (SF), Stroger Hospital of Cook County (Chicago), and Grady Memorial Hospital (Atlanta).

Methods: Using common clinical and research protocols and mixed methods analysis, we examined and compared referral patterns, demographics, and BRCA test results between sites. We used chart reviews and common data collection instruments to gather and pool data. Using descriptive and comparative statistics, we examined similarities and differences between Consortium sites.

Results: SF's program began 9 years ago, Chicago's began 6 years ago, and Atlanta's began 3 years ago. Medicaid funding for BRCA testing has been available in SF since 2011, in Chicago since 2009, and is not yet available in Atlanta. P values were all <0.05 for comparing referral sources between sites. Each site uses unique referral tools and systems. For example, in SF, a family history screening questionnaire is administered during mammography; in Chicago, an extensive primary care network has been educated to provide appropriate referrals; in Atlanta, a pedigree assessment tool is employed by referring clinics.

Pseudo-lyre sign

Carotid body tumours cause characteristic splaying of the internal and external carotid arteries, known as ‘Lyre Sign’. Vagal paragangliomas are rare tumours that arise from glomus cells along the length of the vagus nerve. We present a case in which a vagal paraganglioma has arisen from the vagus nerve at the carotid bifurcation, and has mimicked the ‘Lyre Sign’ of a carotid body tumour.

Safety of infliximab in Crohn's disease: a large single-center experience

BACKGROUND

The aim of this study was to evaluate the short- and long-term safety experience of infliximab treatment in patients with Crohn's disease (CD) in clinical practice.

METHODS

The medical records of 297 consecutive patients with CD treated with infliximab at the Beth Israel Deaconess Medical Center were reviewed for demographic features and adverse events.

RESULTS

The 297 patients received a total of 1794 infusions. Patients received a median of four infusions and had a median follow-up of 14.3 months. Forty-four patients (15%) experienced a serious adverse event, requiring the infusion to be stopped in 33 patients (11%). Acute infusion reactions occurred in 18 patients (6%) including respiratory problems in 10 patients (3%) and an anaphylactoid reaction in 1 patient (0.3%). Serum sickness-like disease occurred in one patient (0.3%) and three patients (1%) developed drug-induced lupus. One patient developed a probable new demyelination disorder. Eight patients (2.7%), all of whom were on concurrent immunosuppressants, developed a serious infection, one resulting in fatal sepsis. Six patients (2%) developed malignancies including two lymphomas and two skin cancers. A total of four (1.3%) deaths were observed (median age 72.5 years); two due to gastrointestinal bleeding, one due to sepsis, and one due to malignancy.

CONCLUSIONS

While short- and long-term infliximab therapy was generally well tolerated, serious adverse events occurred in 15% of patients including drug-induced lupus, fatal sepsis, and malignancy. Concomitant immunosuppressants were significantly associated with infections and deaths, particularly among elderly patients.

Systematic review of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for ovarian peritoneal carcinomatosis: A more efficacious way of delivering intraperitoneal chemotherapy

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Background: Advanced and recurrent ovarian cancer results in extensive dissemination of tumor within the peritoneal cavity. The current evidence suggests that cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) may be a feasible option with potential benefits compared to the current standard of care in the treatment of peritoneal carcinomatosis from ovarian cancer. Methods: A systematic review of relevant studies before August 2008 was undertaken to document and report its efficacy. Each study was appraised using a predetermined protocol. The quality of studies was assessed. The patient characteristics, protocol of treatment, perioperative morbidity and mortality, and treatment outcomes were synthesized through a narrative review with full tabulation of results of all included studies. Results: In total, 15 non-randomized, observational studies were reviewed, comprising of 512 patients. All patients received HIPEC as part of the combined treatment with cytoreductive surgery. Cisplatin was the most common chemoperfusate. The mortality associated with the treatment ranged from 0 to 10%. The rates of severe morbidity ranged from 0 to 40%. The median time of follow up ranged from 14 to 64 months, the median disease-free survival ranged from 10 to 57 months and the overall median survival ranged from 22 to 64 months. In patients who had an optimal cytoreduction, the median survival ranged from 29 to 66 months, with a 3- and 5-year survival rate that ranged from 35 to 63% and 12 to 66%, respectively. Conclusions: The future for cytoreductive surgery and HIPEC in ovarian cancer is promising. More studies are called for to validate the efficacy of this treatment. For it to become generally accepted, the oncology community must commit to a randomized trial. Before this, the current treatment of cytoreductive surgery combined with adjuvant intraperitoneal and intravenous chemotherapy should remain the mainstay of treatment.

No significant financial relationships to disclose.

Neutralizing anti-interferon beta antibodies are associated with reduced side effects and delayed impact on efficacy of Interferon-beta

Interferon-beta (IFNbeta) is a biological therapy which is immunogenic, inducing anti-IFN-beta neutralizing antibodies (Nabs) in some subjects. The frequency of Nabs varies depending on IFN-beta product and the Nab assay used.

OBJECTIVE

Assess frequency of Nabs using novel Luciferase assay, evaluate association with relapses, frequency of side effects and to compare results with published data.

METHODS

Serum samples at 12 and 24 months and a follow up sample were tested for binding and Nabs. Titre >20 NU was considered positive. Charts were reviewed retrospectively for clinical data.

RESULTS

Out of 327 subjects included, 130 subjects (40%) were binding antibody positive, 89 (27%) were Nab +ve at anytime. Risk at 12 months for being Nab +ve: Avonex 8%, Betaferon 39%, Rebif 33%, P < 10(-5); at 24 months 8, 31 and 27% respectively, P = 0.002. Nab titres were highest in Rebif Nab +ve subjects - 50% >320 NU. Annualized relapse rate was 1.53 pre-treatment, after treatment relapse rate was higher in Nab +ve group 0.67 (95% CI 0.38-0.97) versus 0.5 (0.38-0.61) Nab -ve P = 0.04. Nab status at 12 and 24 months was significantly associated with risk of subsequent relapse, risk being greatest in those with highest titres. Side effects were also significantly associated with Nab -ve status.

How we do it: Changes in thyroid and salivary gland surgery since 1989: who's doing it and what are they doing?

Keypoints * The aim of this study was to identify changes in the provision of parotid, submandibular and thyroid gland surgery between surgical specialties since 1989, as well as changes in surgical practice. * Data from the Department of Health's Hospital Episode Statistics (HES) was extracted from 1989/1990 and 2003/2004 records by operation and surgical specialty in England. * The data reveals a considerable decline in the amount of parotid and submandibular surgery performed by General surgeons; with the majority of this surgery currently being performed by ENT surgeons, and to a lesser extent, Oral and Maxillo-Facial surgeons. * Thyroid surgery has undergone less radical change, with General surgeons continuing to perform the majority of cases; however, an increasing proportion is now provided by ENT surgeons. * There also seems to be changes in the types of thyroid operation being performed; with large increases in total thyroidectomy and reductions in subtotal thyroidectomies.

Simple keel fixation technique for endoscopic repair of anterior glottic stenosis

The use of keels in the treatment of anterior glottic stenosis is well established. A variety of methods for keel fixation have previously been documented. We describe a simple technique of securing a Silastic keel, placed endoscopically, with a simple percutaneous suture, after laser vaporization of an anterior commissure web.

Clinicopathologic review of malignant polyps in stage 1A carcinoma of the endometrium

OBJECTIVES

The aims of this study were to determine the incidence of malignant polyps in stage 1A endometrial cancer, to define the pathological features of such cancers, and to assess whether clinical outcome differs from similar cancers without a malignant polyp.

METHODS

We performed a retrospective pathological review of 107 cases of stage 1A endometrial cancer treated at two centers in New South Wales between January 1988 and July 2003. The presence of a malignant polyp was determined and a pathological description made of the tumor. Clinical data were collected, including prior tamoxifen usage, tumor recurrence and survival. The outcome of the malignant polyp group was compared to the same histological subtype not involving a malignant polyp.

RESULTS

The incidence of malignant polyps in our series was 32%. Malignant polyps occurred in all 8 cases involving a serous subtype. Precursor lesions of endometrial cancer were identified within malignant polyps. Three out of the four recurrences occurred in high-grade tumor subtypes and all four had a large primary tumor (size > or = 4 cm). When comparing the same subtype of tumor with and without a malignant polyp, there was no significant difference in clinical outcome.

CONCLUSIONS

Approximately one-third of stage 1A endometrial cancers are associated with a malignant polyp. Serous carcinoma commonly arises within an otherwise benign endometrial polyp. Malignant polyps offer an opportunity to identify precursors of endometrial carcinoma. Clinical outcome of stage 1A endometrial carcinoma was related to the histological subtype and the size of the tumor rather than the presence of a malignant polyp.

Performance measurements of a depth-encoding PET detector module based on position-sensitive avalanche photodiode read-out

We are developing a high-resolution, high-efficiency positron emission tomography (PET) detector module with depth of interaction (DOI) capability based on a lutetium oxyorthosilicate (LSO) scintillator array coupled at both ends to position-sensitive avalanche photodiodes (PSAPDs). In this paper we present the DOI resolution, energy resolution and timing resolution results for complete detector modules. The detector module consists of a 7 x 7 matrix of LSO scintillator crystals (1 x 1 x 20 mm3 in dimension) coupled to 8 x 8 mm2 PSAPDs at both ends. Flood histograms were acquired and used to generate crystal look-up tables. The DOI resolution was measured for individual crystals within the array by using the ratio of the signal amplitudes from the two PSAPDs on an event-by-event basis. A measure of the total scintillation light produced was obtained by summing the signal amplitudes from the two PSAPDs. This summed signal was used to measure the energy resolution. The DOI resolution was measured to be 3-4 mm FWHM irrespective of the position of the crystal within the array, or the interaction location along the length of the crystal. The total light signal and energy resolution was almost independent of the depth of interaction. The measured energy resolution averaged 14% FWHM. The coincidence timing resolution measured using a pair of identical detector modules was 4.5 ns FWHM. These results are consistent with the design goals and the performance required of a compact, high-resolution and high-efficiency PET detector module for small animal and breast imaging applications.

Glucocorticoid resistance in inflammatory bowel disease

Glucocorticoids are potent inhibitors of T cell activation and proinflammatory cytokines and are highly effective treatment for active inflammatory bowel disease (IBD). However, failure to respond, acutely or chronically, to glucocorticoid therapy is a common indication for surgery in IBD, with as many as 50% of patients with Crohn's disease (CD) and approximately 20% of patients with ulcerative colitis (UC) requiring surgery in their lifetime as a result of poor response to glucocorticoids. Studies report that approximately one-third of patients with CD are steroid dependent and one-fifth are steroid resistant while approximately one-quarter of patients with UC are steroid dependent and one-sixth are steroid resistant. While the molecular basis of glucocorticoid resistance has been widely assessed in other inflammatory conditions, the pathophysiology of the glucocorticoid resistance in IBD is poorly understood. Research in IBD suggests that the phenomenon of glucocorticoid resistance is compartmentalised to T-lymphocytes and possibly other target inflammatory cells. This review focuses on three key molecular mechanisms of glucocorticoid resistance in IBD: (i) decreased cytoplasmic glucocorticoid concentration secondary to increased P-glycoprotein-mediated efflux of glucocorticoid from target cells due to overexpression of the multidrug resistance gene (MDR1); (ii) impaired glucocorticoid signaling because of dysfunction at the level of the glucocorticoid receptor; and (iii) constitutive epithelial activation of proinflammatory mediators, including nuclear factor kappa B, resulting in inhibition of glucocorticoid receptor transcriptional activity. In addition, the impact of disease heterogeneity on glucocorticoid responsiveness and recent advances in IBD pharmacogenetics are discussed.