Video-assisted thoracoscopic management of mediastinal tumors.

BACKGROUND: Many successful attempts at removing benign mediastinal tumors with the video-assisted thoracoscopic technique have been reported, but no formal report has been published regarding malignant mediastinal tumors treated with this technique. We report our preliminary experience with video-assisted thoracoscopic removal of mediastinal tumors, benign or malignant. METHODS: Seven patients with mediastinal tumors treated with video-assisted thoracoscopic surgery were reviewed from January 1999 to April 2000. Their tumor pathologies included benign or malignant thymoma, neurilemmoma, and teratoma. RESULTS: The mean operation time was 240 minutes. The mean blood loss was 173 mL. The mean insertion time of chest tubes was 3 days. The mean admission time was 6 days. No deaths occurred during the study. Morbidity occurred in 2 patients. No tumor recurrence has been seen during the mean follow-up of 7 months. CONCLUSIONS: The short-term results support the feasibility of VATS in managing technically resectable mediastinal tumors. Yet the long-term prognosis for the malignant lesions is deferred and needs further study.     

Immunosuppressive activity of serum taken from a liver transplant recipient after withdrawal of immunosuppressants

In orthotopic liver transplantation (OLT), tolerance is induced in a certain combination of donors and a recipient in rats and, in some clinical cases, rejection has not occurred in OLT patients after weaning off immunosuppression. However, this mechanism has not yet been elucidated. Among our cases of liver transplantation (LTx), one OLT patient (Patient A) has not required immunosuppressive drugs for the last 5 years, following post-transplant lymphoproliferative disease (PTLD). This patient's serum interleukin-2 levels were undetectable following withdrawal of immunosuppressants. The same serum taken after discontinuing the immunosuppressants inhibited concanavalin A blast cultured cells and up-regulated the IL-4/IFN-gamma gene expression ratio. These results suggested that other proteins were induced following withdrawal of immunosuppressants. Proteomic assay demonstrated 12 differentiated spots exclusive to this patient where immunosuppressants have been discontinued. Haptoglobin, found to have immunosuppressive activity in vitro, may play an important role in the maintenance of drug-free tolerance as a natural immunological suppressor after cessation of immunosuppression. Proteomic analysis will allow us to develop a novel weaning protocol for patients on long-term immunosuppression to avoid major immunosuppressant-related complications.     

Spinal cord injury increases the risk of Type 2 diabetes: a population-based cohort study

Background contextPrevious studies on the risk and prevalence of diabetes among spinal cord injury (SCI) patients are limited and controversial.PurposeTo compare the risk and incidence rate (IR) of Type 2 diabetes in SCI and non-SCI patients.Study designThis is a population-based retrospective cohort study.Patient sampleData from Taiwan's National Health Insurance Research Database for the period 1997 to 2010 were analyzed. Patients aged 20 years and older newly identified with SCIs during this period were included in the SCI cohort. A non-SCI comparison cohort was randomly selected from National Health Insurance beneficiaries and matched with the SCI cohort based on age, sex, and index date.Outcome measuresBoth cohorts were followed until the first of the following occurred: the diagnosis of Type 2 diabetes (International Classification of Disease, Ninth Revision, Clinical Modification codes 250), withdrawal from the insurance system, the end of 2010, or death.MethodsA Cox proportional hazards regression analysis was used to estimate the risk of developing diabetes.ResultsTaiwan possesses an older SCI population, with a mean age of 51.6 years. The IR for diabetes in patients with and without SCIs was 22.1 per 10,000 person-years and 17.2 per 10,000 person-years, respectively. The adjusted hazard ratio (HR) for diabetes was 1.33 times higher in patients with SCIs than in those without SCIs. In patients with SCIs, men (adjusted HR=1.23, 95% confidence interval (CI)=1.04–1.44), older people (adjusted HR=4.26 in patients older than 65 years, 95% CI=3.16–5.74), patients with comorbidity (adjusted HR=1.36, 95% CI=1.14–1.62), and patients with a complete thoracic SCI (T-spine injury) (adjusted HR=2.13, 95% CI=0.95–4.79) were more likely to be diagnosed with diabetes than other patient subgroups.ConclusionsOur findings may facilitate the prioritizing of preventive health strategies and planning of long-term care for SCI patients.     

Analysis of chest X-ray plain film images of intravenous ports inserted via the superior vena cava

Purposes

The optimal tip position for an intravenous port and the angle between the locking nut and the catheter are still debatable. This study evaluates the use of chest X-ray plain films for screening patients with potential intravenous port complications.

Methods

We reviewed, retrospectively, 1505 patients who had an intravenous port implanted between January 1 and December 31, 2006 at Chang Gung Memorial Hospital, and were followed up until June 30, 2010. Of the 1119 patients with an intravenous port implanted via the superior vena cava (SVC), 279 underwent re-interventions for complications. There were four different types of single lumen port, and entry vessels on the right side were utilized as the predominant entry sites through the vessel cut-down method for catheter cannulation. The anatomic catheter tip was confirmed on the postero-anterior view of plain chest X-ray films. We used the Picture Arching and Communicating System (PACS) (GE, Fairfield, CT, USA) to record the angle and distance in degrees and centimeters, respectively.

Results

The tracheal carina was seen easily on the chest X-ray plain film and the location of the catheter tip and the angle between the locking nut and the catheter were identified. The location of the catheter tip was significantly related to migration (p < 0.0001). The cut-off value of the receiver operating characteristic (ROC) curve for location and migration was 0.68 cm below the carina. The area under the curve (AUC) was 0.8385 and had favorable predictive power.

Conclusion

The ideal position of an intravenous port to avoid migration is 0.68 cm below the carina. For surgeons, a quantified reference may minimize technical errors. Patients with shallow tip location should be followed up regularly and aggressive intervention initiated for any intravenous port malfunction.     

Noninvasive detection of graft injury after heart transplant using donor‐derived cell‐free DNA: A prospective multicenter study

Standardized donor‐derived cell‐free DNA (dd‐cfDNA) testing has been introduced into clinical use to monitor kidney transplant recipients for rejection. This report describes the performance of this dd‐cfDNA assay to detect allograft rejection in samples from heart transplant (HT) recipients undergoing surveillance monitoring across the United States. Venous blood was longitudinally sampled from 740 HT recipients from 26 centers and in a single‐center cohort of 33 patients at high risk for antibody‐mediated rejection (AMR). Plasma dd‐cfDNA was quantified by using targeted amplification and sequencing of a single nucleotide polymorphism panel. The dd‐cfDNA levels were correlated to paired events of biopsy‐based diagnosis of rejection. The median dd‐cfDNA was 0.07% in reference HT recipients (2164 samples) and 0.17% in samples classified as acute rejection (35 samples; P = .005). At a 0.2% threshold, dd‐cfDNA had a 44% sensitivity to detect rejection and a 97% negative predictive value. In the cohort at risk for AMR (11 samples), dd‐cfDNA levels were elevated 3‐fold in AMR compared with patients without AMR (99 samples, P = .004). The standardized dd‐cfDNA test identified acute rejection in samples from a broad population of HT recipients. The reported test performance characteristics will guide the next stage of clinical utility studies of the dd‐cfDNA assay.     

Visualization of suppressed thyroid tissue by Tc-99m MIBI.

The authors describe a case of suppressed normal thyroid tissue in a patient with autonomous toxic nodule, which was visualized by a Tc-99m MIBI thyroid scan without thyrotropin (TSH) stimulation. The findings suggest that Tc-99m MIBI can be a substitute for conventional thyroid imaging using I-131 to visualize suppressed normal thyroid tissue without TSH stimulation and its side effects.     

Quantitative 99Tcm-HMPAO white blood cells and 67Ga scanning in rheumatoid arthritis

This investigation assessed 99Tcm-HMPAO white blood cell (Tc-WBC) and 67Ga knee uptake indices before and after 90Y treatment in patients with intractable rheumatoid arthritis (RA) and correlated the uptake indices with the clinical score. Sixteen knee joints with RA were treated with intra-articular injection of 185 MBq of 90Y-silicate colloid (Amersham) flushed with 50 mg of hydrocortisone. Clinical score, quantitative 67Ga and Tc-WBC knee uptake indices were obtained before and three weeks after treatment. Our results showed that 9/16 (56%) had a good response and 7/16 (44%) had a poor response to 90Y injection. There was poor correlation between clinical improvement and changes in 67Ga and Tc-WBC knee uptake indices (r = 0.46 and 0.14, respectively). The correlation coefficient between changes in 67Ga and Tc-WBC knee uptake indices was 0.29.     

The influences of blood glucose and duration of fasting on myocardial glucose uptake of [18F]fluoro-2-deoxy-D-glucose

During the study of chest using positron emission tomography (PET) with [18F]fluoro-2-deoxy-d-glucose (FDG), a significant myocardial FDG uptake can prevent detection of the lesion that is located either behind or closely attached to the heart border. Two well-known and possible factors of myocardial FDG uptake are blood glucose level and fasting duration before FDG PET scanning. This study investigates whether the two factors are related to myocardial FDG uptake. Our study also explores the possibility of eliminating myocardial FDG uptake by controlling patients' blood glucose level and/or fasting duration. Whole-body FDG PET scans performed on 270 consecutive patients performed were reviewed. The study subjects were classified into four grades of myocardial FDG uptake according to the visual interpretation of the FDG PET image hard-copy films. For all study subjects, the blood sugar level and fasting duration before FDG injection were recorded. Then, the blood sugar levels and fasting duration were compared to the visual grade of myocardial FDG uptake for each study subject. About half of the study subjects showed graded 0 myocardial FDG uptake when the blood glucose levels were < or = 120 mg x dl(-1) or when the fasting duration was between 5 and 12 h. One hundred and thirty-one of the 142 (92%) patients with graded 0 uptake were asked to fast for > or = 4 h and had blood glucose levels < or = 120 mg x dl(-1). Based on our findings, we conclude that controlling the patients' blood glucose levels to < or = 120 mg x dl(-1) and at least 5 h fasting should be recommended to decrease myocardial FDG uptake.     

Regional mapping of the phenylalanine hydroxylase gene and the phenylketonuria locus in the human genome.

Phenylketonuria (PKU) is an autosomal recessive disorder of amino acid metabolism caused by a deficiency of the hepatic enzyme phenylalanine hydroxylase (PAH; phenylalanine 4-monooxygenase, EC 1.14.16.1). A cDNA clone for human PAH has previously been used to assign the corresponding gene to human chromosome 12. To define the regional map position of the disease locus and the PAH gene on human chromosome 12, DNA was isolated from human-hamster somatic cell hybrids with various deletions of human chromosome 12 and was analyzed by Southern blot analysis using the human cDNA PAH clone as a hybridization probe. From these results, together with detailed biochemical and cytogenetic characterization of the hybrid cells, the region on chromosome 12 containing the human PAH gene has been defined as 12q14.3----qter. The PAH map position on chromosome 12 was further localized by in situ hybridization of 125I-labeled human PAH cDNA to chromosomes prepared from a human lymphoblastoid cell line. Results of these experiments demonstrated that the region on chromosome 12 containing the PAH gene and the PKU locus in man is 12q22----12q24.1. These results not only provide a regionalized map position for a major human disease locus but also can serve as a reference point for linkage analysis with other DNA markers on human chromosome 12.     

Propagation of cutaneous thermal injury: a mathematical model

Cutaneous burn wounds represent a significant public health problem with 500,000 patients per year in the USA seeking medical attention. Immediately after skin burn injury, the volume of the wound burn expands due to a cascade of chemical reactions, including lipid peroxidation chain reactions. Such expansion threatens life and is therefore highly clinically significant. Based on these chemical reactions, the present paper develops for the first time a three-dimensional mathematical model to quantify the propagation of tissue damage within 12 hours post initial burn. We use the model to investigate the effect of supplemental antioxidant vitamin E for intercepting propagation. We show, for example, that if tissue levels of vitamin E tocotrienol are increased, postburn, by five times then this would slow down the lipid peroxide propagation by at least 50%. We chose the alpha-tocotrienol form of vitamin E as it is a potent inhibitor of 12-lipoxygenase, which is known to propagate oxidative lipid damage. Our model is formulated in terms of differential equations, and sensitivity analysis is performed on the parameters to ensure the robustness of the results.