Day: 11/21/2012

Worlds Smallest Petrol Engine

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Scientists have created the smallest petrol engine in the world ( less than a centimeter long not even half an inch ), small enough to power a watch or any small gadget. The mini-motor, which runs for two years on a single squirt of lighter fuel, is set to revolutionize world technology. It generates 700 times more energy than a conventional battery. It could be used to operate laptops and mobile phones for months doing away with the need for charging. Experts believe it could be phasing out batteries in such items within just six years. The engine, minute enough to be balanced on a fingertip, has been produced by engineers at the University of Birmingham.

SCI FI or REAL WEAPONS.

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These are real highly sophisticated weapons developed by the US . most have them are successful.

They are all inspired by science fictions and sci fi movies.

 

HAPPY THANKSGIVING DAY.

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DW-MRI: identifying lymph node metastases.

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Diffusion-weighted MRI (DW-MRI) is showing particular promise in aiding the identification of lymph node metastases, according to several recently published studies.

In a review paper published in the journal Radiology earlier this year, specialists summarized data on DW-MRI in the head and neck. This included a detailed section on nodal metastases, noting that “the general consensus appears to be that ADCs [apparent diffusion coefficients] of malignant nodes are significantly lower than those of benign nodes”.

In one study there was a clear lack of any overlap between the higher ADCs of benign lesions and the lower ADCs of malignant lesions. However, the variety of head and neck lesions that can occur means it is often impractical to establish a single ADC threshold for distinguishing between benign and malignant lesions.

The specialists wrote: “Although these results show the potential of DW imaging for characterization of head and neck lesions, given the heterogenous group of benign and malignant lesions that arise in the head and neck, there will clearly be exceptions and overlap in ADC results.” Future research should include the establishment of ADC thresholds for specific sites and for specific pathologic processes , they argued.1

Meta-analysis: squamous cell carcinoma
Meanwhile, the diagnostic accuracy of standard and DW-MRI in detecting lymph node metastases in patients with head and neck squamous cell carcinoma (HNSCC) was the subject of a meta-analysis recently published in the journal Academic Radiology.

Using data from 16 studies, the researchers in Shanghai, China, calculated that the sensitivity and specificity of standard MRI for determining cervical lymph node status were 76% and 86% respectively. MRI was similar to other diagnostic tools such as PET, CT, and ultrasound, in terms of performance, they added.

A subgroup analysis, however, showed that DW-MRI had a significantly higher sensitivity (86%) than standard MRI. The researchers noted that more data are needed, concluding: “A limited number of small studies suggest DW imaging is superior to conventional imaging for nodal staging of HNSCC”.2

Prospective study in breast cancer
Finally, in the October issue of the Journal of Magnetic Resonance Imaging, specialists reported the findings of a prospective study of the accuracy of DW-MRI in distinguishing between metastatic and benign axillary lymph nodes in patients with breast cancer.

The researchers compared two groups, divided according to histology findings: 19 lymph nodes with a metastasis at least 5 mm in diameter and 24 lymph nodes with no malignant cells (nodes with metastases smaller than 5 mm were excluded from the study).

Overall, the ADC values were significantly lower for the lymph nodes with metastases, compared with the benign lymph nodes (p < 0.001). The researchers identified a threshold for ADC values that resulted in a high sensitivity, specificity, and accuracy (94.7%, 91.7%, and 93%, respectively) for this series of patients.

They concluded: “From these preliminary data, DW imaging seems a promising method in the differential diagnosis between metastatic and benign axillary lymph nodes in patients with breast cancer.”3

References:
1. Thoeny HC, et al. Radiology. 2012;263:19-32.
2. Wu LM, et al. Acad Radiol. 2012;19:331-40.
3. Fornasa F, et al. J Magn Reson Imaging. 2012;36:858-64.

Source: http://www.getinsidehealth.com

 

123I-MIBG scintigraphy in HF.

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Heart failure (HF) is characterized by alterations in myocardial sympathetic nerve activity; an increased sympathetic response is initially favorable by serving as compensation for decreased cardiac output, but as HF progresses, this response leads to deleterious neurohormonal and myocardial structural…

Abstract

Iodine-123-metaiodobenzylguanidine (123I-MIBG) scintigraphy is a nuclear medicine technique which describes the functional status of the cardiac sympathetic nervous system. It is well known that an autonomic dysfunction is present in heart failure setting as a neuronal uptake of norepinephrine is impaired in the failing myocardium. Reduction in sympathetic nervous function in the heart, measured by reduced myocardial uptake of 123I-MIBG, is an indicator of poor prognosis for heart failure patients. The aim of this paper was to investigate the role of 123I-MIBG scintigraphy in evaluating the need of implantable cardioverter defibrillator (ICD) and the response to cardiac resynchronization therapy (CRT) in heart failure patients. For this purpose scientific literature data on these topics were reviewed. Based on literature data, 123I-MIBG scintigraphy seems to be a useful tool to assess which patients may benefit most from an ICD implantation to reduce the risk of ventricular arrhythmia or sudden cardiac death. Furthermore, 123I-MIBG scintigraphy seems to predict which patients will response to CRT with an improvement in left ventricular function.

Source: http://www.getinsidehealth.com

Comparing methods for evaluating Mullerian structures.

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Disorders of sex development (DSD) are a group of congenital conditions with atypical development of chromosomal, gonadal, or anatomic sex [, ]. It is estimated that the incidence of genital anomaly is 2 in 10,000 live births [, ], although some degree of male undervirilization or female…

Abstract

Purpose   The diagnosis of children with disorders of sex development (DSD) requires a karyotype, different biochemical and radiological investigations in the context of a multidisciplinary team. The aim of this study was to compare the diagnostic accuracy of laparoscopy (L) versus ultrasonography (US) in the assessment of children with complex DSD.
Methods   We retrospectively examined the theatre database searching for children with DSD who underwent laparoscopic surgery from 1999 to 2011. The medical and radiological records were reviewed.
Results   Eighteen patients were identified. Age at diagnosis ranged from birth to 14 years (mean 2.5 years). There were seven patients with 46XY dysgenetic testicular DSD (4 mosaic Turner, 3 mixed gonadal dysgenesis), seven patients with 46XY non-dysgenetic testicular DSD (4 persistent Mullerian duct syndrome, 2 complete androgen insensitivity syndrome, one unknown), two patients with ovotesticular DSD, one patient with 46XX DSD (congenital adrenal hyperplasia) and one patient with 46XY DSD complete sex reversal. Fifteen underwent ultrasonography prior to laparoscopy. Both modalities identified Mullerian structures in seven (47 %) patients, in one (7 %) patient US and L confirmed the absence of Mullerian structures, while in six (40 %) patients there was discordance, with US failing to visualize pelvic Mullerian structures. In the last patient with 46XY non-dysgenetic testicular DSD, the rectum was thought to be a dilated uterus on ultrasonography.
Conclusions   Pelvic ultrasonography failed to identify Mullerian structures in 40 % of patients with complex DSD. On the contrary, laparoscopy allowed excellent visualization of pelvic structures and gonads in children with complex DSD.

Source: http://www.getinsidehealth.com

 

Fecal Immunochemical Testing for Colorectal Cancer Screening.

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FIT detected most cancers, but only a minority of advanced adenomas.

Fecal immunochemical testing (FIT) might be more accurate than guaiac-based fecal occult blood testing (gFOBT) in screening for colorectal cancer. In this Dutch study, 1256 average-risk patients submitted single specimens for FIT (OC-Sensor) just before undergoing screening colonoscopy.

Colonoscopy identified 8 patients (0.6%) with colorectal cancer and 113 (9%) with advanced adenomas. At a cutoff of 50 ng/mL, FIT was positive in 10% of patients. Sensitivity and specificity of FIT for detecting advanced adenomas were 38% and 93%, respectively. For colorectal carcinoma, sensitivity was 88% (i.e., FIT was positive in 7 of 8 patients with cancer), and specificity was 91%. Five of the seven FIT-positive cancers were localized (Dukes stage A). FIT detected proximal and distal advanced neoplasia with equal sensitivity.

The Journal Watch General Medicine Perspective

According to these findings, if patients were screened initially with a single FIT, most localized cancers and about one third of advanced adenomas would be detected, and 90% of patients (those who were FIT-negative) would avoid colonoscopy. Failure to detect most advanced adenomas is not necessarily a fatal flaw, if additional research shows that repeated FIT screening (i.e., at 1- or 2-year intervals) detects many of these lesions before they progress to unresectable cancers. One of our Journal Watch Gastroenterology editors, an expert in colorectal cancer screening, comments below on FIT.

The Journal Watch Gastroenterology Perspective

Current colorectal cancer screening guidelines recommend that clinicians who use fecal blood testing switch from gFOBT to FIT (Am J Gastroenterol 2009; 104:739). Consistent results from several types of studies, including randomized, controlled trials, indicate that patient adherence (i.e., completion of the test) and test sensitivity strongly favor FIT over gFOBT. Several national screening programs outside the U.S. now are based on FIT, and cost-effectiveness analyses suggest that annual FIT is at least as cost-effective as is colonoscopy every 10 years. Several randomized, controlled trials, including one in U.S. Veterans Administration hospitals) have been organized to compare FIT and colonoscopy.

A practical problem that clinicians encounter when they try to switch to FIT is the lack of comparative performance data on the several commercial FIT assays available in the U.S. Several years ago, in a study of six commercial FITs available in Germany, researchers found that several had awful performance characteristics, including very poor specificity. However, the laboratory-based assay used in the current study (OC-Sensor) has been evaluated in many studies and is believed to perform best.

This Dutch study suggests that FIT is equally effective in both the proximal and distal colon, whereas some previous evidence had suggested better performance in the distal colon. This result is encouraging, but the endpoint for the study was advanced conventional (i.e., tubular, tubulovillous, or villous) adenomas. The study ignores (as do all FIT studies) the 30% of colorectal cancers that arise through a genetic pathway characterized by hypermethylation; the precursors of these cancers are not conventional adenomas but rather serrated lesions (sessile serrated polyps, also known as sessile serrated adenomas). Further, these serrated lesions are located primarily in the proximal colon. Endoscopically, these premalignant serrated lesions have no vessels on their surface, and some evidence shows that they don’t bleed at all. The future of sensitive fecal testing that can identify both conventional and serrated precancerous lesions in the proximal colon is more likely to lie in fecal DNA testing than in FIT.

Source: Journal Watch General Medicine

 

PET and Prognosis in Follicular Lymphoma.

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A negative posttreatment PET scan was associated with improved survival in patients with advanced-stage disease.

Complete remission with a negative positron emission tomography (PET) scan after front-line induction chemotherapy is associated with improved outcomes in Hodgkin lymphoma and diffuse large B-cell lymphoma. To assess the prognostic value of PET in follicular lymphoma (FL), European investigators conducted a prospective, multicenter trial involving 117 patients with advanced-stage, high–tumor burden FL who were treated with six cycles of R-CHOP (rituximab plus cyclophosphamide, vincristine, doxorubicin, and prednisone) followed by two additional doses of rituximab. PET scans were performed at baseline, after cycle four (PETC4), and at completion of therapy (PETC8). Independent central review of PET response was performed by three nuclear medicine radiologists and classified by established criteria (Deauville 5-point scale). No treatment modifications were made based on PET findings.

Results were as follows:

  • Of 106 patients who underwent PETC8 imaging, 83 (78%) had negative results.
  • Of 78 patients with negative PETC4 results, 6 (8%) reverted to a positive posttreatment scan.
  • Of 26 patients with positive PETC4 results, 17 (65%) remained positive on PETC8.
  • When comparing PET response to standard computed tomography–based assessment, 53 of 54 patients (98%) with complete remissions were PET-negative, whereas 10 of 20 patients (50%) with complete remissions unconfirmed (CRu) and 9 of 26 patients (35%) with partial remission (PR) remained PET-positive.
  • Patients with negative posttreatment PET had improved 2-year overall survival versus those with a positive scan (100% vs. 88%; P=0.01).
  • Progression-free survival was improved for those with negative versus positive PETC4 or PETC8.

Comment: This is the first prospective study to demonstrate a prognostic benefit for negative posttreatment PET in FL. The predictive value was independent of both low-risk and high-risk FLIPI (Follicular Lymphoma International Prognostic Index) scores. The authors recommend that only posttreatment PET rather than interim PET be used and that scan use be reserved for CRu and PR patients. Confirmation of these results in additional prospective trials will be important, as will careful application of standardized PET response criteria and PET response–based treatment algorithms.

Source: Journal Watch Oncology and Hematology

 

Is Herpes Simplex Encephalitis in Immunocompromised Patients Different?

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A comparison of clinical findings, neuroimaging, and outcomes in immunocompromised versus immunocompetent patients with HSE suggests important differences.

Herpes simplex encephalitis (HSE) is a very serious disease with an incidence of 1 in 250,000 to 1 in 500,000. With the introduction of new and more potent immunosuppressive therapies, HSE is seen more often with an atypical presentation. In this retrospective case-control review of adult patients with HSE diagnoses, researchers compared features and outcomes in 14 patients who were immunocompromised and 15 who were immunocompetent.

Clinical features, magnetic resonance imaging (MRI), and cerebrospinal fluid (CSF) findings were different in the two groups. Fewer immunocompromised patients had prodromal symptoms (29% vs. 80%) and focal deficits (about 28% vs. 73%). Mean time between symptom onset and presentation to the hospital was shorter in the immunocompromised group (3.4 vs. 4.9 days). Whereas all immunocompetent patients had mononuclear cells in the CSF and one had no CSF pleocytosis, three immunocompromised patients had polymorphonuclear predominance and another three had normal profiles. Whereas all immunocompetent patients had MRI abnormalities in the temporal lobe, immunocompromised patients tended to have more diffuse cortical involvement, with cerebellar and brainstem compromise in some. Two of the immunocompromised patients and none of the immunocompetent patients had recurrent HSE, and 5 of the 14 immunocompromised patients died, versus 1 of the 15 immunocompetent patients. Similar numbers of patients in each group completed a 21-day treatment with acyclovir (30 mg/kg/day). Five immunocompetent patients completed a 14-day course.

Comment: Although this study is limited by its retrospective nature and its size, this is the largest published series on HSE in immunocompromised patients and the first to compare the presentation in immunocompromised and immunocompetent states. The findings should raise awareness of the potential increased risk, atypical presentations, and worse outcomes among immunocompromised patients. Early recognition of the disease is critical, because delay in treatment may be associated with severe morbidity and mortality. Early diagnosis and administration of acyclovir is associated with a better outcome.

Source: Journal Watch Neurology

Periodic Health Exams in General Population Don’t Reduce Mortality Risk .

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General wellness checks to identify disease risk factors and symptoms in healthy people appear to have no effect on mortality, according to a Cochrane meta-analysis in BMJ.

Researchers analyzed the results of 14 randomized trials comprising some 180,000 adults (geriatric trials were excluded). Patients were randomized either to health checks conducted in a primary care or community setting or to no health checks. The exams were not associated with a reduction in all-cause, cardiovascular, or cancer-related mortality.

An editorialist concludes: “The history of health promotion through routine health checks has been one of glorious failure, but generations of well meaning clinicians and public health physicians struggle to allow themselves to believe it. We need to reinforce the message lest some enthusiast reinvent the health check in another guise.”

Source: BMJ