Impedance-Based Rapid Diagnostic Tool for Single Malaria Parasite Detection.

This paper presents a custom, low-cost electronic system specifically designed for rapid and quantitative detection of the malaria parasite in a blood sample. The system exploits the paramagnetic properties of malaria-infected red blood cells (iRBCs) for their magnetophoretic capture on the surface of a silicon chip. A lattice of nickel magnetic micro-concentrators embedded in a silicon substrate concentrates the iRBCs above coplanar gold microelectrodes separated by 3 µm for their detection through an impedance measurement. The sensor is designed for a differential operation to remove the large contribution given by the blood sample. The electronic readout automatically balances the sensor before each experiment and reaches a resolution of 15 ppm in the impedance measurement at 1 MHz allowing a limit of detection of 40 parasite/µl with a capture time of 10 minutes. For better reliability of the results, four sensors are acquired during the same experiment. We demonstrate that the realized platform can also detect a single infected cell in real experimental conditions, measuring human blood infected by Plasmodium falciparum malaria specie.

On-chip magnetophoretic capture in a model of malaria-infected red blood cells.

The search for new rapid diagnostic tests for malaria is a priority for developing an efficient strategy to fight this endemic disease, which affects more than 3 billion people worldwide. In this study, we characterize systematically an easy-to-operate lab-on-chip, designed for the magnetophoretic capture of malaria-infected red blood cells (RBCs). The method relies on the positive magnetic susceptibility of infected RBCs with respect to blood plasma. A matrix of nickel posts fabricated in a silicon chip placed face down is aimed at attracting infected cells, while healthy cells sediment on a glass slide under the action of gravity. Using a model of infected RBCs, that is, erythrocytes with methemoglobin, we obtained a capture efficiency of about 70% after 10 min in static conditions. By proper agitation, the capture efficiency reached 85% after just 5 min. Sample preparation requires only a 1:10 volume dilution of whole blood, previously treated with heparin, in a phosphate-buffered solution. Nonspecific attraction of untreated RBCs was not observed in the same time interval.

A Lab-On-chip Tool for Rapid, Quantitative, and Stage-selective Diagnosis of Malaria.

Malaria remains the most important mosquito-borne infectious disease worldwide, with 229 million new cases and 409.000 deaths in 2019. The infection is caused by a protozoan parasite which attacks red blood cells by feeding on hemoglobin and transforming it into hemozoin. Despite the WHO recommendation of prompt malaria diagnosis, the quality of microscopy-based diagnosis is frequently inadequate while rapid diagnostic tests based on antigens are not quantitative and still affected by non-negligible false negative/positive results. PCR-based methods are highly performant but still not widely used in endemic areas. Here, a diagnostic tool (TMek), based on the paramagnetic properties of hemozoin nanocrystals in infected red blood cells (i-RBCs), is reported on. Exploiting the competition between gravity and magnetic forces, i-RBCs in a whole blood specimen are sorted and electrically detected in a microchip. The amplitude and time evolution of the electrical signal allow for the quantification of i-RBCs (in the range 10-105 i-RBC µL-1) and the distinction of the infection stage. A preliminary validation study on 75 patients with clinical suspect of malaria shows on-field operability, without false negative and a few false positive results. These findings indicate the potential of TMek as a quantitative, stage-selective, rapid test for malaria.

Laparoscopic trans-cystic common bile duct exploration and treatment of choledocholithiasis in a patient with Roux-en-Y reconstruction after gastrectomy: report of an emergency case.

We present the case of choledocholithiasis with purulent cholangitis treated with laparoscopic approach in a patient with Roux-en-Y reconstruction after total gastrectomy. After cholangiography, the common bile duct was explored with trans-cystic choledochoscopy and the retained stone extracted under direct vision.

On-Chip Selective Capture and Detection of Magnetic Fingerprints of Malaria.

The development of innovative diagnostic tests is fundamental in the route towards malaria eradication. Here, we discuss the sorting capabilities of an innovative test for malaria which allows the quantitative and rapid detection of all malaria species. The physical concept of the test exploits the paramagnetic property of infected erythrocytes and hemozoin crystals, the magnetic fingerprints of malaria common to all species, which allows them to undergo a selective magnetophoretic separation driven by a magnetic field gradient in competition with gravity. Upon separation, corpuscles concentrate at the surface of a silicon microchip where interdigitated electrodes are placed in close proximity to magnetic concentrators. The impedance variation proportional to the amount of attracted particles is then measured. The capability of our test to perform the selective detection of infected erythrocytes and hemozoin crystals has been tested by means of capture experiments on treated bovine red blood cells, mimicking the behavior of malaria-infected ones, and suspensions of synthetic hemozoin crystals. Different configuration angles of the chip with respect to gravity force and different thicknesses of the microfluidic chamber containing the blood sample have been investigated experimentally and by multiphysics simulations. In the paper, we describe the optimum conditions leading to maximum sensitivity and specificity of the test.

The impact of anastomotic leak and its treatment on cancer recurrence and survival following elective colorectal cancer resection.

AIM: Anastomotic leakage is a serious complication in restorative colorectal surgery. Anastomotic leakage and its subsequent management may have long-term impact on survival. This study aims to assess the impact of colorectal anastomotic leak (AL) on overall survival (OS) and disease-free survival (DFS). METHODS: A prospective database of 1,048 patients undergoing restorative colorectal cancer resections at St Mark's hospital between October 2004 and October 2013 was examined. RESULTS: The overall leak rate was 99/1,048 (9.4%). 43 ALs were managed conservatively with antibiotics or radiological drainage and 56 with reoperations. OS was significantly reduced in the AL group treated with a reoperation (HR 2.74, 95% CI 1.67-4.52, p < 0.001). AL was not significantly associated with worse DFS [conservatively managed AL's vs. no AL-HR 2.07 (95% CI 1.05-4.10); reoperated AL's vs. no AL-HR 1.56 (95% CI 0.81-2.99), overall p value = 0.058]. CONCLUSION: Patients who suffer anastomotic leaks requiring reoperations have worse OS compared to patients who do not leak, but there were no significant differences in DFS between patients who leaked and those who did not.

A new handheld electromagnetic cortical stimulator for brain mapping during open skull neurosurgery: a feasibility study.

Transcranial magnetic stimulations have provided invaluable tools for investigating nervous system functions in a preoperative context; in this paper we propose an innovative tool to extend the magnetic stimulation to an open skull context as a promising approach to map the brain cortex. The present gold standard for intraoperative functional mapping of the brain cortex, the direct brain stimulation, has a low spatial resolution and limited penetration and focusing capabilities. The magnetic stimulatory device that we present, is designed to overcome these limitations, while working with low currents and voltages. In the present work we propose an early study of feasibility, in which the possibility of exploiting a train of fast changing magnetic fields to reach the neuron's current thresholds is investigated. Measurements of electric field intensity at different distances from the coil, showed that the magnetic stimulator realized is capable of delivering an electric field on a loop of wire theoretically sufficient to evoke neuron's action potential, thus showing the approach' feasibility.

The emerging role of neutrophil to lymphocyte ratio in determining colorectal cancer treatment outcomes: a systematic review and meta-analysis.

BACKGROUND: There is growing evidence suggesting that the neutrophil to lymphocyte ratio (NLR) can act as an independent predictor of long-term outcomes in patients undergoing treatment for colorectal cancer (CRC). This study aims to systematically review the role of NLR in predicting survival for patients with CRC undergoing treatments, and to evaluate its utility within a CRC surveillance program. METHODS: This meta-analysis was performed according to PRISMA guidelines. Outcomes of interest included disease-free survival (DFS) for patients undergoing treatment with curative intent and progression-free survival (PFS) in patients undergoing treatments with palliative intent. RESULTS: Thirteen observational cohort studies published from 2007 to 2013 evaluated the role of NLR as a predictor of outcome following treatment for CRC. These included (i) patients undergoing surgery to resect the primary cancer (seven studies); (ii) those undergoing palliative chemotherapy (three studies); and (iii) patients undergoing potentially curative treatments for CRC liver metastases (three studies). When all studies were considered, a high pretreatment NLR independently predicted survival (HR 2.08; 95 % CI 1.64-2.64). A high NLR also predicted significantly poorer survival in each of the three groups. Finally, over a 3-year follow-up period, high NLR became a significant predictor of poor outcome at year 2 (HR 2.76; 95 % CI 2.06-3.69; p < 0.00001) and 3 (HR 2.03; 95 % CI 1.48-2.78; p < 0.0001), but not in the first year of follow-up (HR 1.47; 95 % CI 0.89-2.41; p = 0.13). CONCLUSIONS: Elevated preoperative NLR is associated with poorer survival in CRC patients undergoing treatment and may have a role in CRC surveillance programs as a means of delivering more personalized cancer care.

A preoperative neutrophil to lymphocyte ratio of 3 predicts disease-free survival after curative elective colorectal cancer surgery.

OBJECTIVE: This study aims to determine the role of the neutrophil to lymphocyte ratio (NLR) as a prognostic marker for patients with nonmetastatic colorectal cancer undergoing curative resection. BACKGROUND: An NLR reflects a systematic inflammatory response, with some evidence suggesting that an elevated preoperative NLR of more than 5.0 is associated with poorer survival in patients with colorectal cancer. METHODS: Data from 506 consecutive patients with a diagnosis of nonmetastatic colorectal adenocarcinoma undergoing surgical resection between 2006 and 2011 were included. Receiver operating characteristic curve analysis was used to identify the optimal value for NLR in relation to disease-free and overall survival. Univariate and multivariate Cox regression models were used to determine the role of NLR after stratification by several clinicopathological factors. Patients were followed by a standardized protocol until February 2013. RESULTS: Median follow-up was 45 months [interquartile range, 21-65]. Multivariate Cox regression analysis identified an NLR of more than 3 as an independent prognostic factor for disease-free survival (odds ratio = 2.41; 95% confidence interval = 1.12-5.15; P = 0.024) but not for overall survival (odds ratio = 1.23; 95% confidence interval = 0.80-1.90; P = 0.347). A high NLR was significantly associated with older age, higher T and N stages, the presence of microvascular invasion, low preoperative albumin levels, and higher ASA (American Society of Anesthesiologists) status of the patient. CONCLUSIONS: For patients with colorectal cancer, a preoperative NLR of more than 3.0 may be an independent prognostic factor for disease-free survival. Considering this in addition to well-established prognostic variables may improve the processes of identifying patients at higher risk of recurrence who would benefit from adjuvant therapies or more frequent surveillance, thereby providing more personalized cancer care.

Primary adrenal gland carcinosarcoma associated with metastatic rectal cancer: a hitherto unreported collision tumor.

In this report we describe the case of a young woman with familial adenomatous polyposis who developed metastatic rectal cancer during pregnancy. At diagnosis, we decided to perform a transabdominal laparoscopic adrenalectomy, because of the high risk of bowel obstruction, and to define the origin of the adrenal gland lesion, suspected to be primary on the basis of imaging results. The histological specimen showed a collision tumor between an adrenal metastasis of a rectal tumor and a primary adrenal gland carcinosarcoma. The peculiarity of the case is due not only to its clinical presentation during pregnancy, but also to the presence of this uncommon adrenal collision tumor. A particular challenge for the clinician is to define the priority between these two tumors: the presence of two distinct and colliding aggressive neoplasms poses a problem in the choice of the best therapeutic approach, also given the impossibility to biopsy all metastatic sites. However, we decided to treat the patient as having a metastatic rectal cancer, because we had a solid histological confirmation of metastases.

Retrospective descriptive analysis of the physiological kinetics of prostate-specific antigen in men older than 75 years.

Several studies have compared prostate-specific antigen (PSA) kinetics in men with and without cancer, but there has been no adequate analysis of the longitudinal variation in PSA. The aim of this study was to assess the fluctuations in PSA in a cohort of elderly men in an attempt to define a physiological pattern of PSA kinetics. We searched a specific cohort of patients aged > 75 years and with PSA value < 2.0 ng mL(-1). A history of all PSA values over the past 10 years was compiled for each patient to create a database of patients fitting the following criteria: (1) minimum of five PSA measurements, (2) over at least 5 years. Exclusion criteria were: (1) PSA < 0.2 ng mL(-1) at each measurement and (2) having had more than one PSA test per year. In all, 1 327 patients (mean age: 78.52 years) fit the inclusion criteria. The mean variation from the first to the last PSA test was 0.05 +/- 0.43, with a mean follow-up of 6.79 +/- 1.71 years. Over the same period, the mean fluctuation from the lowest to the highest PSA value was 0.04 +/- 0.55 (P = 0.925). The mean annual PSA velocity (PSAV) was calculated by dividing the mean variation from the first to the last PSA test by the number of years of observation for each patient and was set at 0.0104 +/- 0.1050. Concluding, in a large-scale cohort of elderly individuals considered healthy and evaluated for a considerable follow-up, the average annual PSAV as well as the average fluctuation from the lowest to the highest PSA value are insignificant.

Small bowel obstruction by a congenital band. Report of two cases.

The authors report two cases of acute small bowel obstruction, the first in an adult patient, and the second in a three-month-old baby due to a congenital fibrous band. The second case was retrospectively detected from a pool of at least 50 cases of secondary fibrous band obstructions over the period from 1970 to 2008. Surgery was performed early, and simple resection of this very rare malformative bundle (usually affecting very young people) was required.

Voluntary self-amputation of the colon.

We describe an unusual case of self-amputation of a transanal prolapsed colorectal segment by a 48-year-old mentally impaired woman. The surgical procedure and favourable outcome are reported.

Validation and diagnostic efficacy of a TaqMan real-time PCR for the detection of Mycoplasma conjunctivae in the eyes of infected Caprinae.

Infectious keratoconjunctivitis (IKC), caused by Mycoplasma conjunctivae, is a highly contagious ocular disease in Caprinae. To detect rapidly and sensitively M. conjunctivae from individual conjunctival swabs of infected domestic and wild animals, a specific real-time PCR was developed using an lppS-directed hydrolysis probe in a TaqMan platform.

Detection of Dichelobacter nodosus in wild ungulates (Capra ibex ibex and Ovis aries musimon) and domestic sheep suffering from foot rot using a two-step polymerase chain reaction.

Severe keratinous hoof afflictions have been recorded in ibex (Capra ibex ibex) since 1995 and more recently in mouflon (Ovis aries musimon) in Switzerland. Based on clinical observations and comparison with diseases known to affect domestic ungulates, it was hypothesized these wild ungulates were affected by foot rot associated with infection with Dichelobacter nodosus. Dichelobacter nodosus has been shown to be the essential pathogen for initiation and establishment of foot rot, a highly contagious foot disease of sheep and goats. Because these bacteria could not be cultivated from affected ibex, we developed a nested polymerase chain reaction that allowed detection of D. nodosus without culture. Using this assay, we were able to diagnose D. nodosus infections of ibex, mouflon, and domestic sheep in natural outbreaks. From these results we conclude that D. nodosus plays an etiological role in foot rot not only in domestic but also in wild Caprinae.

Serosurvey of roe deer, chamois and domestic sheep in the central Italian Alps.

Roe deer (Capreolus capreolus), chamois (Rupicapra rupricapra rupicapra), and domestic sheep in the Orobie Alps, Italy, were serologically tested for antibodies to selected pathogens that may be transmitted across species. Antibodies against Brucella spp. and bovine herpesvirus 1 (roe deer and chamois only) were not detected in any species. In roe deer, antibodies were detected against Toxoplasma gondii (13%) and Neospora caninum (3%). Chamois tested positive for antibodies to T. gondii (5%), N. caninum (21%), bovine respiratory syncytial virus (BRSV) (41%), bovine parainfluenza type-3 virus (17%), pestiviruses (18%), and Mycoplasma conjunctivae (17%). In the sheep, particularly high antibody prevalence rates were found for T. gondii (78%), Chlamydophila spp. (20%), pestiviruses (90%), BRSV (82%), and M. conjunctivae (81%).

Molecular epidemiology of Mycoplasma conjunctivae in Caprinae: transmission across species in natural outbreaks.

Mycoplasma conjunctivae is the etiological agent of infectious keratoconjunctivitis, a highly contagious ocular infection that affects both domestic and wild Caprinae species in the European Alps. In order to study the transmission and spread of M. conjunctivae across domestic and wild Caprinae populations, we developed a molecular method for subtyping and identifying strains of M. conjunctivae. This method is based on DNA sequence determination of a variable domain within the gene lppS, a gene that encodes an antigenic lipoprotein of M. conjunctivae. This domain of lppS shows variations among different strains but remains constant upon generations of individual strains on growth medium and thus allows identification of individual strains and estimation of their phylogenetic intercorrelations. The variable domain of lppS is amplified by PCR using primers that match conserved sequences of lppS flanking it. Sequence analysis of the amplified fragment enables fine subtyping of M. conjunctivae strains. The method is applicable both to isolated strains and to clinical samples directly without requiring the cultivation of the strain. Using this method, we show that M. conjunctivae was transmitted between domestic and wild animals that were grazing in proximate pastures. Certain animals also presented infections with two different strains simultaneously.

Characterization of LppS, an adhesin of Mycoplasma conjunctivae.

A serine-rich membrane protein named LppS from Mycoplasma conjunctivae, the aetiological agent of infectious keratoconjunctivitis (IKC) of domestic and wild Caprinae, was characterized. Gene cloning and sequence analysis of the lppS gene revealed that it encoded a membrane protein precursor. The protein had a typical signal sequence and a signal peptidase II cleavage site followed by a cysteine residue representing a potential acylation site. The mature LppS protein had an apparent molecular mass of 150 kDa and was found in the detergent-associated fraction of Tween 20 extracted M. conjunctivae proteins. It possessed a serine-rich domain of 41 aa with 37 (90.2 %) serine residues. Twenty-seven of these serine residues were contiguous. The protein adhered to lamb joint synovial cells. Using an in vitro adhesion model, Fab fragments from IgG directed against recombinant purified LppS were shown to specifically inhibit adhesion of M. conjunctivae to lamb cells. Thus, LppS is likely to be an adhesin of M. conjunctivae that may play an important role in the pathogenesis of IKC.

Mycoplasma conjunctivae infection is not maintained in alpine chamois in eastern Switzerland.

The occurrence of infectious keratoconjunctivitis (IKC) was assessed in alpine chamois (Rupicapra rupicapra rupicapra) in Grisons (Switzerland) from 1950 to 1999. The first IKC outbreaks were reported in the 1950's. Since then, the number of affected subpopulations constantly increased and, by 1999, IKC outbreaks were reported in 39 of 51 (77%) chamois sub-populations. From 1992-99, a total of 243 chamois which died of the consequences of IKC were recorded. The number of cases differed between years, and a distinct seasonal trend was observed. Infectious keratoconjunctivitis was more common during summer and autumn, with 48% of the cases recorded in August-October. Juveniles (< 4 yr of age) were mostly represented. To verify the presence of Mycoplasma conjunctivae in chamois we analyzed conjunctival swabs taken from animals affected with IKC. Among a sample of 28 affected chamois, M. conjunctivae was identified 14 times (50%). An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect specific M. conjunctivae antibodies in sera of alpine chamois with IKC. We performed a serologic investigation to assess whether M. conjunctivae infection is self-maintained in the chamois population in Grisons. In subpopulations with IKC oubreaks, seroprevalence was low (8%). Seroprevalence was even lower in subpopulations with recent IKC outbreaks (3%). We concluded that the M. conjunctivae infection is not self-maintained in alpine chamois in Grisons. The agent may originate in domestic sheep living in proximity to chamois during summer. Control of IKC in chamois should consider immunoprophylaxis in sheep or limiting interspecific transmission of M. conjunctivae.