Comparison of molecular diagnosis with serum markers and synovial fluid analysis in patients with prosthetic joint infection.

AIMS: The aim of this study was to compare the results of 16S/28S rRNA sequencing with the erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, and synovial fluid analysis in the diagnosis of prosthetic joint infection (PJI). PATIENTS AND METHODS: Between September 2015 and August 2016, 214 consecutive patients were enrolled. In the study population, there were 25 patients with a PJI and 189 controls. Of the PJI patients, 14 (56%) were women, and the mean age at the time of diagnosis was 65 years (38 to 83). The ESR and CRP levels were measured, and synovial fluid specimens were collected prospectively. Synovial fluid was subjected to reverse transcription polymerase chain reaction (RT-PCR)/sequence analysis targeting the 16S/28S rRNA, and to conventional culture. Laboratory personnel who were blind to the clinical information performed all tests. The diagnosis of PJI was based on the criteria of the Musculoskeletal Infection Society. RESULTS: A total of 25 patients had a confirmed PJI. In 20 cases of monomicrobial PJI, the PCR products could be perfectly matched with the 16S/28S rRNA genes specific for different species of bacteria provided by sequence analysis. Of the five polymicrobial cases of PJI, 16S/28S rRNA PCR sequence analysis failed to identify the concordant bacteria species. In the 189 control patients, there was one false-positive RT-PCR result. The sensitivity and specificity of the molecular diagnosis method were 100% (95% confidence interval (CI) 85.7 to 100) and 99.5% (95% CI 97.1 to 99.9), respectively, whereas the positive and negative predictive values of PCR were 96.1% (95% CI 79.6 to 99.9) and 100% (95% CI 98.1 to 100), respectively. The PCR results were significantly better than serological diagnostic methods (p = 0.004 and p = 0.010 for ESR and CRP, respectively), the synovial fluid white blood cell (WBC) count (p = 0.036), and percentage of polymorphonuclear cells (PMN%) (p = 0.014). CONCLUSION: Stepwise RT-PCR and sequence analysis of the 16S/28S rRNA carried out under stringent laboratory conditions achieved highly sensitive and specific results for the differentiation between aseptic and septic joints undergoing arthroplasty. Sequence analysis successfully identified bacterial strains in monomicrobial infections but failed to identify molecular targets in polymicrobial infections. Further refinement of the protocols to identify the bacteria in polymicrobial infections is needed. Cite this article: Bone Joint J 2018;100-B:1345-51.

Electromagnetic thermotherapy using fine needles for hepatoma treatment.

BACKGROUND AND AIMS: Hepatocellular carcinoma can be treated with heat-based therapies, especially radiofrequency ablation (RFA). However, RFA has limited efficacy and is quite expensive. We designed a new system using fine needles combined with an alternating magnetic field to generate hyperthermia for the treatment of hepatocellular carcinoma in a rat hepatoma model. Our aims are to assess the efficacy of our method and determine survival up to 30 days. METHODS: An N1-S1 cell line was inoculated into the livers of Sprague-Dawley rats, generating tumors after 14 days. The animals were randomized into 5 groups and treated after laparotomy either with normal saline (group I), iron oxide nanoparticles (group II), fine needles (group III), fine needles and iron oxide nanoparticles combined (group IV) or self-designed two-part needles placed under ultrasonographic guidance percutaneously (group V). Every rat was placed in an alternating magnetic field. The temperature in the treatment area was maintained between 55 and 60 °C. At day 30 after treatment, tumor volumes and mortality were assessed and histology samples were studied. RESULTS: Tumor volumes were significantly reduced and survival rate was prolonged in groups III, IV and V versus groups I and II (P < 0.05). On pathological examination, groups III, IV and V presented obvious necrosis, apoptosis, calcifications and inflammatory changes in the treatment area. CONCLUSION: Our study demonstrates that hyperthermia generated by fine stainless-steel needles combined with an alternating magnetic field effectively inhibits hepatoma growth in rats and prolongs their survival. Further, this method can be applied percutaneously under ultrasonographic guidance.

Localised heating of tumours utilising injectable magnetic nanoparticles for hyperthermia cancer therapy.

This study reports an investigation of hyperthermia cancer therapy utilising an alternating magnetic field to induce a localised temperature increase on tumours by using injectable magnetic nanoparticles. In-vitro and in-vivo experiments represent the feasibility of hyperthermia cancer therapy. A feedback temperature control system was first developed to keep the nanoparticles at a constant temperature to prevent overheating in the tumours such that a safer and more precise cancer therapy becomes feasible. By using the feedback temperature control system, magnetic nanoparticles can be heated up to the specific constant temperatures, 37, 40, 42, 45, 46 and 47 degrees C, respectively, with a variation less than 0.2 degrees C. With this approach, the in-vitro survival rate of tumour cells at different temperatures can be systematically explored. It was experimentally found that the survival rate of cancer cells can be greatly reduced while CT-26 cancer cells were heated above 45 degrees C. Besides, localised temperatures increase as high as 59.5 degrees C can be successfully generated in rat livers by using the proposed method. Finally, complete regression of tumour was achieved. The developed method used injectable magnetic nanoparticles and may provide a promising approach for hyperthermia cancer therapy.

Micromachined oxygen gas sensors for microscopic energy consumption measurement systems.

Although the indirect calorimeter is a useful tool, its size and expense mean that it is seldom used in hospitals. Furthermore, its flow-through measurement technique dilutes respiratory variations, so they can only be detected with some form of high-precision instrumentation. This study employs MEMS techniques to develop an oxygen sensor as one part of a microscopic energy consumption measurement system, which measures respiration dynamics in a real time manner. The oxygen sensor comprises a polysilicon resistor and a Li-doped (2 wt%) tin-oxide sensing film attached to a thermally isolated silicon-nitride membrane. The power consumption of the sensor is less than 25 mW at an operating temperature of 150 degrees C. Furthermore, it measures oxygen concentrations between 25 and 85% with a linear output response. These characteristics render the proposed sensor suitable for use within a microscopic energy consumption measurement system in either hospital or homecare environments.

Complementary and alternative medicine use in patients with chronic diseases in primary care is associated with perceived quality of care and cultural beliefs.

OBJECTIVES: The purpose of our study was to determine the prevalence of complementary and alternative medicine (CAM) use and its clinical and psycho-social correlates, including perceived satisfaction with care and cultural health beliefs. METHODS: A cross-sectional study was carried out in public sector primary care clinics in Singapore using a random sample of 488 adult patients with chronic diseases. The measures were CAM use, satisfaction with care and traditional health beliefs. RESULTS: The 1 year prevalence of CAM use was 22.7%. In univariate analyses, factors associated with CAM use included: middle age, arthritis, musculoskeletal disorders and stroke, multiple conditions, poor perceived health, family use of CAM, recommendation by close social contacts, strong adherence to traditional health beliefs and perceived satisfaction with care. Patients who were dissatisfied/very dissatisfied with the cost of treatment [odds ratio (OR) = 1.79, 95% confidence interval (CI) 1.15-2.82] and waiting time (OR = 1.96, 95% CI 1.20-3.19) were more likely to use CAM. Patients who were very satisfied with the benefit from treatment were much less likely to use CAM (OR = 0.49, 95% CI 0.29-0.83). Satisfaction with doctor-patient interaction was not associated with CAM use. Being 'very satisfied' on overall care satisfaction was significantly associated with much less CAM use (OR = 0.30, 95% CI 0.14-0.68). Multivariate analyses confirmed that CAM use was significantly and independently predicted by the 'chronic disease triad' (arthritis/musculoskeletal disorders/stroke) (OR = 4.08, 95% CI 2.45-6.83), overall satisfaction with care (OR = 0.32, 95% CI 0.14-0.74) and strong adherence to traditional health beliefs (OR = 1.88, 95% CI 1.07-3.31). CONCLUSION: CAM use in Asian patients is prevalent and associated with the 'chronic disease triad' (of arthritis, musculoskeletal disorders and stroke), satisfaction with care and cultural beliefs. In particular, CAM use is not associated with the quality of doctor-patient interaction.

Electrokinetic injection techniques in microfluidic chips.

The separation efficiency of a microfluidic chip is influenced to a significant degree by the flow field conditions within the injection microchannel. Therefore, an understanding of the physics of the flow within this channel is beneficial in the design and operation of such a system. The configuration of an injection system is determined by the volume of the sample plug that is to be delivered to the separation process. Accordingly, this paper addresses the design and testing of injection systems with a variety of configurations, including a simple cross, a double-T, and a triple-T configuration. This paper also presents the design of a unique multi-T injection configuration. Each injection system cycles through a predetermined series of steps, in which the electric field magnitude and distribution within the various channels is strictly manipulated, to effectuate a virtual valve. The uniquemulti-T configuration injection system presented within this paper has the ability to simulate the functions of the cross, double-T, and triple-T systems through appropriate manipulations of the electric field within its various channels. In other words, the proposed design successfully combines several conventional injection systems within a single microfluidic chip.

A disposable poly(methylmethacrylate)-based microfluidic module for protein identification by nanoelectrospray ionization-tandem mass spectrometry.

The design, fabrication, and analytical use of a poly(methylmethacrylate) (PMMA)-based microfluidic module for nanoelectrospray ionization-tandem mass spectrometry (nano-ESI-MS/MS) were described. The microfluidic module can be mass-produced at low costs and used as a disposable device to generate nano-ESI-MS/MS signals for protein identification from low amounts of protein samples. Compared with commercially available nanospray capillary tips, the module gave comparable signal quality and also offered advantages in convenience and easiness of operation, permitting repeated usage, and disposability.

Plastic microchip electrophoresis for genetic screening: the analysis of polymerase chain reactions products of fragile X (CGG)n alleles.

Clinical screening of abnormal chromosomes associated with fragile X syndrome (FXS) demands a high-throughput method including DNA sizing and detection of the amplified products. This study is to explore the use of polymer microchip electrophoresis for the analysis of polymerase chain reaction (PCR) products of fragile X (CGG)n alleles to facilitate a fast exclusion test of FXS. The sequences flanking the CGG-repeat of FMR1 gene was amplified by betaine-PCR and the amplified products were desalted and then analyzed by microchips which were fabricated on poly(methyl methacrylate) (PMMA) substrate. The PCR bands with more than six CGG-repeats in difference could be clearly distinguished in less than 3 min by microchip electrophoresis with a separation length of 6 cm. It was found that the signal was greatly enhanced with the use of both covalent (Cy5) and intercalating dye (TORRO-3), which has never been demonstrated before. We tested the method by reanalysis of twelve samples from males and six samples from females. For female samples with less than six repeat differences, Southern blotting method was performed to confirm or exclude the findings from microchips. It was found that the test results from all male and female samples show a 100% correlation between the microchip electrophoresis and the existing methods.

Establishment and characterization of chromosomal aberrations in human cholangiocarcinoma cell lines by cross-species color banding.

Cholangiocarcinoma (CC), a malignant neoplasm of the biliary epithelium, is usually fatal because of difficulty in early diagnosis and lack of availability of effective therapy. Furthermore, little is known about the genetics and biology of CC. Only a few reports concerning cytogenetic studies of CC have been published, and few cell lines have been established. We recently established four CC cell lines, designated as SCK, JCK, Cho-CK, and Choi-CK, and report the first application of cross-species color banding (RxFISH) and multiple chromosome painting for the characterization of the chromosomal rearrangements of these CC cell lines. Each cell line had unique modal karyotypic characteristics and showed a variable number of numerical and structural clonal cytogenetic aberrations. Chromosomes 3, 6, 7, 8, 12, 14, 17, and 18 were commonly involved in structural abnormalities. Homogeneously staining regions were determined in SCK and JCK, and double minute chromosomes were found in Cho-CK. The chromosomal aberrations of the four CC cell lines were effectively analyzed by RxFISH and FISH with multiple chromosome painting probes. The nonrandom rearrangements suggest candidate regions for isolation of genes related to CC.

Flow-through sampling for electrophoresis-based microfluidic chips using hydrodynamic pumping.

This work presents a novel electrophoretic microchip design which is capable of directly coupling with flow-through analyzers for uninterrupted sampling. In this device, a 3 mm wide sampling channel (SC) was etched on quartz substrate to create the sample inlet and outlet and the 75 microm wide electrophoretic channels were also fabricated on the same substrate. Pressure was used to drive the sample flow through the external tube into the SC and the flow was then split into outlet and electrophoretic channels. A gating voltage was applied to the electrophoretic channel to control the sample loading for subsequent separations and inhibit the sample leakage. The minimum gating voltage required to inhibit the sample leakage depended on the solution buffer and increased with the hydrodynamic flow-rate. A fluorescent dye mixture containing Rhodamine B and Cy3 was introduced into the sample stream at either a continuous or discrete mode via an on-line injection valve and then separated and detected on the microchip using laser-induced fluorescence. For both modes, the relative standard deviation of migration time and peak intensity for consecutive injections was determined to be below 0.6 and 8%, respectively. Because the SC was kept floating, the external sampling equipment requires no electric connection. Therefore, such an electrophoresis-based microchip can be directly coupled with any pressure-driven flow analyzers without hardware modifications. To our best knowledge, this is something currently impossible for reported electrophoretic microchip designs.

Decreased activity of hepatic uroporphyrinogen decarboxylase in sporadic porphyria cutanea tarda.

To investigate the role of uroporphyrinogen decarboxylase in the pathogenesis of the sporadic form of porphyria cutanea tarda, we measured this enzyme in liver, erythrocytes and cultured skin fibroblasts, and also measured coproporphyrinogen oxidase and the total iron concentration in liver. The mean uroporphyrinogen decarboxylase activity was lower in liver from seven male patients (9.0 pmol of coproporphyrin per minute per milligram of protein) than in 12 controls, including seven with alcoholic liver disease (22.3 pmol per minute per milligram; P less than 0.05). Coproporphyrinogen oxidase activities were the same in each group. Liver iron concentrations were lower during remission, but uroporphyrinogen decarboxylase activities were not related to clinical activity for uroporphyrin excretion. Erythrocyte and fibroblast enzyme activities were the same as in normal subjects. A hepatic uroporphyrinogen decarboxylase defect is a prerequisite for the development of porphyria cutanea tarda, but other factors, which probably do not alter uroporphyrinogen decarboxylase activity, determine the clinical onset. In sporadic porphyria cutaneous tarda, the enzyme defect appears to be restricted to the liver.

Familial foveal retinoschisis.

Three young women, offspring of a nonconsanguineous marriage of normal parents, manifested mild visual loss associated with a bilateral foveal dystrophy that resembled the macular involvement in juvenile sex-linked retinoschisis. Electrophysiologic and psychophysiologic tests showed less severe involvement than the gonosomal equivalent. An autosomal recessive inheritance is proposed.

Lymphosarcoma in Crohn's disease: report of a case.

In a patient who had a family history of ulcerative colitis and colonic carcinoma, a jejunal lymphosarcoma developed four years after resection for Crohn's disease of the small intestine. It is suggested that the association of lymphosarcoma with Crohn's disease is more than a chance association.

Photoelectron microscopy: a new approach to mapping organic and biological surfaces.

A general method of imaging organic and biological surfaces based on the photoelectric effect is reported. For the experiments, a photoelectron emission microscope was constructed. It is an ultrahigh vacuum instrument using electrostatic electron lenses, microchannel plate image intensifier, cold stage, hydrogen excitation source, and magnesium fluoride optics. The organic surfaces examined were grid patterns of acridine orange, fluorescein, and benzo(a)pyrene on a Butvar surface. A biological sample, sectioned rat epididymis, was also imaged by the new photoelectron microscope. Good contrast was obtained in these initial low magnification experiments. These data demonstrate the feasibility of mapping biological surfaces according to differences in ionization potentials of exposed molecules. A number of technical difficulties, such as the intensity of the excitation source, must be solved before high resolution experiments are practical. However, it is probable that this approach can be useful, even at low magnifications, in determination of the properties of organic and biological surfaces.