Development of the first PCR for detection of Psoroptes ovis var. cuniculi infection and its comparison to microscopic examination and serological assay in rabbits.

Psoroptes mites are the common ecto-parasites of wild and domestic animals worldwide, which causes considerable economic losses in livestock industry. Microscopy is deemed to be the 'gold standard' for the diagnosis of Psoroptes mite infection but it has poor sensitivity for low mite infections and/or sub-clinical infections. To overcome these shortcomings, we screened four genes to develop a sensitive and specific PCR for the detection of Psoroptes mite infection in rabbits, and confirmed its practicability in detecting early infection and monitoring treatment outcome with traditional microscopy and serological tests. Results showed that PCR assay targeting ITS2 (ITS2-PCR) had a high specificity and sensitivity (detection limit: 40.3 pg/µL DNA) for detecting P. ovis DNA. In rabbits artificially infected with P. ovis, all three diagnostic tests showed the same detection rate from 14 days post infection (dpi) to 42 days dpi. However, these diagnostic tests behave differently at 7 dpi and after treatment: at 7 dpi, the detection rate of ITS2-PCR was higher than rPsoSP3-based iELISA and traditional microscopy (ITS2-PCR: 88.9%, rPsoSP3-iELISA: 77.7%, microscopy: 33.3%); at 7 days post treatment (dpt), positivity rates of ITS2-PCR and microscopy rapidly decreased to 0.00% and 11.1%, whereas rPsoSP3-iELISA remained 100% positive rate. Furthermore, the comprehensive comparisons of diagnostic performance and features of three diagnostic tests at 7 dpi were performed. Compared to ITS2-PCR or rPsoSP3-iELISA, microscopy had the lowest sensitivity, and the agreement between these assays was low (κ < 0.3). Field study showed that ITS2-PCR showed a higher detection rate than microscopy (19.4% and 11.1%, respectively). Our results suggested that the ITS2-PCR developed in this study provided a new laboratory tool for diagnosis of P. ovis var. cuniculi infection, and it had advantages over microscopic examination in detection low-level mite infections and serological assay in monitoring treatment outcome.

Slowing down light using a dendritic cell cluster metasurface waveguide.

Slowing down or even stopping light is the first task to realising optical information transmission and storage. Theoretical studies have revealed that metamaterials can slow down or even stop light; however, the difficulty of preparing metamaterials that operate in visible light hinders progress in the research of slowing or stopping light. Metasurfaces provide a new opportunity to make progress in such research. In this paper, we propose a dendritic cell cluster metasurface consisting of dendritic structures. The simulation results show that dendritic structure can realise abnormal reflection and refraction effects. Single- and double-layer dendritic metasurfaces that respond in visible light were prepared by electrochemical deposition. Abnormal Goos-Hänchen (GH) shifts were experimentally obtained. The rainbow trapping effect was observed in a waveguide constructed using the dendritic metasurface sample. The incident white light was separated into seven colours ranging from blue to red light. The measured transmission energy in the waveguide showed that the energy escaping from the waveguide was zero at the resonant frequency of the sample under a certain amount of incident light. The proposed metasurface has a simple preparation process, functions in visible light, and can be readily extended to the infrared band and communication wavelengths.

Leiomyosarcoma in the nasopharynx: MR imaging findings.

The MR imaging findings of a leiomyosarcoma arising from the nasopharynx are presented. To our knowledge, this is the first MR imaging description of this entity.

Squeeze maneuver: an easy way to manage radiological contrast-medium extravasation.

BACKGROUND: Contrast-medium extravasation injuries may be self-limited to catastrophic. Adequate prophylactic measures are enforced when risk factors for extravasation are present, and prompt treatment can avoid serious complications. PURPOSE: To describe the squeeze maneuver, an effective method for the treatment of symptomatic contrast-medium extravasation. MATERIAL AND METHODS: Over a 3-month period, eight patients with >50 ml contrast-medium extravasation resulting in vascular compromise of the fingers were managed with the squeeze maneuver as follows. The intravenous catheter used for contrast-medium injection was removed, and the skin around the insertion site was cleaned with povidone-iodine. An 18-gauge needle was then used to puncture five to eight openings near the catheter insertion site as deeply as possible. We then began squeezing from the periphery of the swelling toward the needle holes. As the contrast medium drained, it was swabbed away with iodine-soaked cotton swabs. RESULTS: In all eight patients, the maneuver was successful with immediate resolution of the vascular compromise. CONCLUSION: The squeeze maneuver provides an easy way to manage radiological contrast-medium extravasation and can be performed immediately in the CT suite.

Reflex regulation of antagonist muscles for control of joint equilibrium position.

A systems model of spinal neuro-musculo-skeletal system (alpha - gamma model) is developed to investigate the plausible roles of spinal proprioceptive feedback in movement control. The model is composed of a joint, a pair of antagonist muscles, length and velocity feedback from muscle spindle, as well as spinal stretch reflex, reciprocal inhibition and recurrent inhibition of Renshaw cells. A descending command modulates the background activation of alpha motoneuron pools in combination with these reflex activities. A static gamma command controls the fusimotor contraction of the spindle. Simulation results reveal that the equilibrium joint angle is linearly correlated to the level of static gamma fusimotor activity of the spindle for a wide range of external loading conditions and reflex gains, suggesting that these spinal reflexes may contribute to regulate the equilibrium position of the joint. Sensitivity analysis further shows that reflex gains and other central commands alter the quasi-linear relation in regular fashions. The reciprocal inhibition gain changes the slope of the linear theta(eq) - gamma curve; and the descending alpha excitation, the stretch reflex gain, and the external load all shift the theta(eq) - gamma curve in parallel. These results imply that reflex gains and descending alpha commands may be coordinated to maintain a unique theta(eq) - gamma curve while providing the flexibility to counteract external loads, to execute a movement, or to regulate additional muscle variables. Dynamic simulation suggests that control of a class of movements can be achieved with a triphasic, alpha pulse and a continuous gamma signal. The model study supports the notion of a dual strategy for controlling trajectories via a feedforward alpha command and for regulating the final equilibrium positions via a feedback gamma command.

Are modified procedures significantly better than conventional procedures in percutaneous transhepatic treatment for complicated right hepatolithiasis with intrahepatic biliary strictures?

BACKGROUND: Conventional percutaneous procedures for treating patients with recurrent hepatolithiasis associated with complicated intrahepatic biliary strictures require multiple dilation sessions before stone extraction. We modified the approach, reducing the number of dilation sessions required and using newer lithotripsy and irrigation methods. We suggest that the modified procedures are superior to conventional management and demonstrate their utility in clearing hepatolithiasis. METHODS: Percutaneous transhepatic stricture dilation and cholangioscopic lithotripsy were performed to treat patients with right recurrent hepatolithiasis with complicated intrahepatic biliary strictures. Conventional methods were used in 40 patients (Group A). Modified methods, including simplification of tract establishment and stricture dilation and electrohydraulic lithotripsy (EHL) were used in 60 patients (Group B). RESULTS: Group B patients had fewer complications (massive hemobilia: 0% versus 15%, P = 0.0032, cholangitis: 0% versus 17.5%, P=0.0012), tolerated the procedures better (intolerable pain: 0% versus 12.5%, P=0.0087), had a higher rate of success (residual stones: 3.3% versus 20%, P=0.0132; remaining asymptomatic and stone-free: 81% versus 50%, P = 0.0021), a shorter hospital stay (17.8 +/- 4.4 days versus 36.2 +/- 5.5 days, P < 0.001) and lower overall expense (USD 2689 versus USD 3848) than Group A patients. CONCLUSION: We believe that the modified methods are superior to conventional treatment in that they effectively decrease procedural complications and cost, and significantly improve treatment results.

The benefits of a second transhepatic route in failed percutaneous management of difficult intrahepatic biliary strictures with recurrent hepatolithiasis.

Percutaneous stricture dilatation and cholangioscopic lithotomy has become a mainstay in the treatment of patients with recurrent hepatolithiasis associated with intrahepatic biliary strictures. In a consecutive series of 125 patients who underwent percutaneous management of recurrent hepatolithiasis from 1987 to 1999, there were 15 patients in whom the procedure failed to clear the stones. A second percutaneous transhepatic route was established for subsequent treatment. A reappraisal of its indications and efficacy was done. Treatment through a second route was helpful for patients with bilateral strictures, angulated duct, difficult strictures, large impacted stones, a subcutaneous jejunal limb, or hemobilia developing in the first route. Strictures remained impacted in 1 of the 15 patients (failure rate, 7%), with the remaining having complete clearance of stones. Cholangitis occurred in two patients; no other complications were encountered. A second percutaneous route is very helpful for the management of complicated hepatolithiasis and biliary stricture.

Percutaneous transhepatic cholangioscopy in the treatment of complicated intrahepatic biliary strictures and hepatolithiasis with internal metallic stent.

For recurrent hepatolithiasis coexisting with a complicated long-segment intrahepatic biliary stricture, repeated surgeries, balloon dilation of the stricture, and external-internal stenting may still fail to solve the problem. We tried using a Gianturco-Rosch metallic Z internal stent (Wilson-Cook Medical, Inc., Bloomington, IN, USA) with the aid of percutaneous transhepatic cholangioscopy (PTCS) to treat such patients. Eight patients had a Z stent placed through a percutaneous transhepatic biliary drainage tract. Immediately after stent placement, PTCS was inserted via the percutaneous transhepatic biliary drainage route and a part of the wire skirt not firmly anchored in one of the eight patients was detected. It was successfully repositioned using PTCS. Recurrent cholangitis developed in three patients 6, 7, and 30 months, respectively, after stent placement. PTCS was undertaken again through a reestablished percutaneous transhepatic biliary drainage route and revealed sludge in their stent lumens. We cleared it by PTCS. No further cases of cholangitis occurred in later follow-up. PTCS is useful in ensuring adequate stent position, diagnosing and treating the causes of recurrent cholangitis, and prolonging the function of stents.

Occlusion of azygos vein via direct percutaneous puncture of innominate vein following cavopulmonary anastomosis.

A 2-year-10-month-old boy was diagnosed with a complex congenital heart disease: right atrial isomerism, left superior vena cava (LSVC), complete atrioventricular septal defect, secundum type atrial septal defect, transposition of the great arteries with pulmonary atresia, patent ductus arteriosus, absence of a right superior vena cava (RSVC), and dextrocardia. He had received a left Blalock-Taussig (BT) shunt at the age of 3 months and a left bidirectional Glenn shunt one year after BT shunt. Progressive cyanosis was noted after the second operation and cardiac catheterization showed a functional Glenn shunt with an engorged azygos vein, which was inadvertently skipped for ligation. Because of the absence of RSVC, transcatheter occlusion of the azygos vein was performed successfully via direct puncture of the innominate vein.

Alterations of p16/MTS1 gene in oral squamous cell carcinomas from Taiwanese.

To determine the alterations of the p16/MTS1 gene in oral squamous cell carcinoma (OSCC), we examined in Taiwanese patients the mutation, deletion and methylation of p16/MTS1 in primary OSCCs associated mostly with betel quid (BQ)/tobacco use. Among 110 tumors undergoing mutational analyses, seven (6%) showed mutations in exon 2 or the intron 1/exon 2 splice site. All but one mutation disrupted the encoded proteins. Base transitions represented the vast majority (6/7) of the mutations identified in BQ/tobacco consuming subjects. It was noted that 15/56 (27%) tumors examined by restriction fragment methylation analysis revealed a significant level of methylation in different loci of exon 1 as compared with the respective non-cancerous tissue. Mutation of p16/MTS1 was exclusively identified in carcinomas of buccal mucosa, whereas methylation of the p16/MTS1 promoter region occurred preferentially in carcinomas of the tongue (54%) rather than at other sites (22%). Homozygous deletion was not found in 56 paired samples examined, nor was hemizygous deletion indicated in 12 informative cases. The results indicated aberrant methylation and mutation as the molecular abnormality of p16/MTS1 in the OSCC from Taiwanese.

Percutaneous transhepatic placement of metallic stents in the treatment of complicated intrahepatic biliary stricture with hepatolithiasis: a preliminary report.

OBJECTIVE: We aimed to study the effect of the metallic modified Gianturco-Rosch Z-stent in the management of refractory intrahepatic long-segment biliary strictures with hepatolithiasis. METHODS: Six symptomatic patients with hepatolithiasis and coexisting intrahepatic long-segment biliary strictures, who failed to respond to the silastic external-internal biliary stenting, were selected. The metallic modified Gianturco-Rosch Z-stent was placed via percutaneous transhepatic cholangiography at the strictured site. Patients were followed regularly to evaluate for recurrence of cholangitis, stones, or strictures. RESULTS: No complications were observed during the procedures. No recurrent strictures or formed calculi were found in these six patients during follow-up periods of 29 to 64 months. However, cholangitis and intrahepatic biliary muddy sludge occurred at 7 and 30 months in two patients after the placement of the metallic Z-stent. Percutaneous transhepatic cholangioscopy was used to clear sludge completely. CONCLUSIONS: Our experience suggests that the metallic stent is a well-tolerated and promising alternative in the management of refractory intrahepatic long-segment biliary strictures with hepatolithiasis. Though biliary sludge may develop, it can be detected and cleared early. Repeated surgery can thus be avoided.

Synthesis and decomposition of transient-evoked otoacoustic emissions based on an active auditory model.

In this paper, transient-evoked otoacoustic emissions (TEOAE's) are synthesized by an active auditory model, and decomposed by continuous wavelet transform (CWT) to study the frequency-latency relationship and the generation of TEOAE signals. The controlled voltage sources that relate to the mobile mechanism of the outer hair cells (OHC's) are proposed to serve as the generation sources of TEOAE signals. The state-variable method is adopted to calculate the auditory model. The mother wavelet used in CWT is selected on basis of the model. The results of this study show that the simulated TEOAE signal is similar to the clinically detected ones not only in the time-domain waveform, but also in the frequency-latency relationship. It seems to be clear that the generation of TEOAE signals is related to the same active mechanism as the cochlear sharp frequency selectivity.

A fast recursive-least-squares adaptive notch filter and its applications to biomedical signals.

A fast recursive-least-squares (FRLS) adaptive notch filter (ANF) for cancellation of sinusoidal interference from recorded biomedical signals is investigated. The FRLS ANF is derived by making an approximation to the conventional recursive-least-squares (RLS) ANF for computation economy. It outperforms the commonly adopted least-mean-squares (LMS) ANF, demonstrating a rapid and bandwidth-insensitive initial convergence. A novel application of the FRLS ANF is for the elimination of the tonal artefact in distortion product otoacoustic emission (DPOAE) signals.

Are expandable metallic stents better than conventional methods for treating difficult intrahepatic biliary strictures with recurrent hepatolithiasis?

BACKGROUND: Conventional methods for treating patients with recurrent hepatolithiasis associated with complicated intrahepatic biliary strictures include balloon dilatation of the intrahepatic biliary strictures, lithotripsy, and the clearance of difficult stones as completely as possible, with the placement of an external-internal stent for at least 6 months. After these modalities are used, symptomatic refractory strictures remain. Recently we used internal Gianturco-Rosch metallic Z stents to treat patients who had refractory strictures. OBJECTIVE: To compare therapeutic results and complications of an internal expandable metallic Z stent with those of repeated external-internal stent placement. STUDY DESIGN: Case-control study. SETTING: A referral center. PATIENTS: From January 1992 to December 1996, 18 patients with recurrent hepatolithiasis and complicated intrahepatic biliary strictures underwent percutaneous dilatation of stricture and transhepatic percutaneous cholangioscopic lithotomy for recurrent stones. After their stones were completely cleared, their biliary strictures failed to dilate satisfactorily. The patients were randomly enrolled into 2 groups: group A (7 patients), who received an expandable metallic Z stent, and group B (11 patients), who had repeated placement of external-internal stents. INTERVENTIONS: Percutaneous stricture dilatation, electrohydraulic lithotripsy, balloon dilatation, percutaneous transhepatic cholangioscopic lithotomy, and biliary stenting by a Silastic external-internal catheter or a modified Gianturco-Rosch expandable metallic Z stent (for an internal stent). MAIN OUTCOME MEASURES: The number of procedures, days in hospital, procedure-related complications, incidents of stone recurrence and recurrence of cholangitis, readmissions to the hospital, treatment sessions required, and mortality rate. Patients' limitations in ordinary activities were also compared. RESULTS: The follow-up period ranged from 28 to 60 (40.7+/-12.7 [mean +/- SD]) months in group A and from 28 to 49 (36.0+/-7.2) months in group B. Fewer group A patients (3 [43%]) than group B patients (8 [73%]) tended to have recurrent cholangitis and to require readmission to the hospital, but this was not statistically significant (P = .33). When their cumulative probability of a first episode of cholangitis during follow-up was compared, however, it was significantly lower in patients treated with a metallic stent (P = .04). Compared with group B patients, group A patients had less frequent recurrence of stones (0% vs 64%; P = .01), fewer procedures for the clearance of biliary stones or sludge (1.7+/-2.2 vs 6.4+/-4.3; P = .03), and shorter hospital stays (8.0+/-11.5 days vs 17.0+/-12.0 days; P = .07). No patients in group A experienced limitation in ordinary activities, whereas 7 patients in group B did (P<.02). CONCLUSIONS: Compared with the repeated placement of external-internal stents, the use of a metallic internal stent effectively decreases stone recurrence, simplifies further procedures, and is more convenient. Its use is suggested as an alternative choice in the treatment of recurrent hepatolithiasis with refractory intrahepatic biliary strictures.

Metastatic hepatocellular carcinoma presenting as hemocholecyst with perforation: a case report.

In case of hepatocellular carcinoma (HCC), the gallbladder is less frequently involved and metastasis to the gallbladder, together with its significant clinical manifestations, is rarely discussed in the literature in detail. HCC with metastasis to the gallbladder, initially presenting as gallbladder intraluminal hemorrhage and perforation, has not been previously reported. We present a case of HCC disclosed by emergency cholecystectomy for hemocholecyst with perforation. Evaluation of the possible metastatic mechanisms is also discussed.

Watershed infarction of spinal cord after the embolization of bronchial artery: a case report.

A case of watershed infarction in the spinal cord is reported. The patient underwent bronchial artery embolization for control of massive hemoptysis. The bronchial arteriogram was carefully examined and focused on blood supply to the spinal cord prior to embolization. Acute paraparesis followed the embolization procedure even though there was no visible spinal supply on the arteriogram. Magnetic resonance imaging showed a hyperintensity lesion over the watershed region which is located at the central portion of the upper thoracic cord. This case is reported to emphasize the significant role which angiographically invisible small vessels can play in the blood supply to the spinal cord. The vascular system of the spinal cord and the prevention of spinal cord ischemia secondary to embolization are further discussed here.

Reappraisal of the systematic management of complicated hepatolithiasis with bilateral intrahepatic biliary strictures.

OBJECTIVE: To compare the results, limitations, and complications of the surgical treatment of bilateral hepatolithiasis and intrahepatic biliary strictures with left hepatectomy and without left hepatectomy. DESIGN: Case-controlled study. SETTING: Referral center. PATIENTS: During a 12-year period, 103 patients with bilateral hepatolithiasis and intrahepatic biliary strictures underwent surgical treatment. Group A (n = 73) received left hepatic resection (lateral segmentectomy or lobectomy) and postoperative biliary dilatation with residual stone extraction. Group B (n = 30) underwent the same procedures except for left hepatectomy. INTERVENTIONS: Left lateral segmentectomy or left lobectomy, choledocholithotomy, postoperative cholangioscopic treatments (electrohydraulic lithotripsy, other lithotripsy, lithotomy, balloon dilatation, etc. via T tube or precutaneous transhepatic route). MAIN OUTCOME MEASURES: Days of hospitalization, incidence of major and minor complications, mortality rates, and the rates of residual stones and stone recurrence were compared. RESULTS: Group A and B had similarly low postoperative 1-month mortality rates of 5.5% and 6.7%, respectively. The main cause of death in both groups was uncontrollable septicemia. The main major complications in group A were intra-abdominal abscess and upper gastrointestinal bleeding; the major complication in group B was massive hemobilia. Group B had a significantly higher overall rate of complications (53.3% vs 23.3%, P < .01) and a longer hospital stay than group A (median, 72 days vs 28 days, P < .03). When complications were classified as major or minor, only minor complications showed a significant difference (30% vs 13.7%, P = .05). After using biliary stricture dilatation and stone extraction, the rate of residual stones in the right lobe was similar in both groups, but patients in group B had a significantly higher rate of residual stones (12.5% vs 0%, P < .02) and stone recurrence in the left lobe (19% vs 0%, P < .003) than those in group A. CONCLUSIONS: Partial resection of the left lobe in cases of bilateral hepatolithiasis and biliary strictures can effectively simplify problems in the treatment of bilateral hepatolithiasis and intrahepatic biliary strictures. In addition, not only were surgical complications not increased, but a decrease in complications from postoperative manipulations for stone clearance was noted in our series.

Broadband fiber-optical parametric amplifiers and wavelength converters with low-ripple Chebyshev gain spectra.

Theory predicts that a two-pump fiber optical parametric amplifier or wavelength converter operated near the fiber zero-dispersion wavelength can exhibit a gain spectrum approximated by a Chebyshev polynomial of order 8. Under realistic conditions of pump spacing and fiber dispersion, very low-gain ripple can be obtained over a large bandwidth. For example, a dispersion-shifted fiber can provide a signal amplifier with a gain of 20 dB with 0.2-dB uniformity over a 45-nm bandwidth. Potential limitations are discussed.