Propofol does not inhibit lidocaine metabolism during epidural anesthesia

Propofol is sometimes used in combination with epidural anesthesia with lidocaine. In this study, we investigated the effect of propofol on the plasma concentration of lidocaine and its principal metabolites during epidural anesthesia with lidocaine. Thirty-two patients were randomly allocated to receive either propofol or sevoflurane anesthesia (n = 16 each). In the propofol group, anesthesia was maintained with a target concentration of propofol of 4 microg/mL. In the sevoflurane group, anesthesia was maintained with 1.5% sevoflurane. Lidocaine was administered epidurally in an initial dose of 5 mg/kg, followed by a continuous infusion at 2.5 mg x kg(-1) x h(-1). Free components of plasma lidocaine and its metabolites-monoethylglycinexylidide (MEGX) and glycinexylidide (GX)-were measured 30, 60, 120, and 180 min after the initiation of continuous epidural injection by using high-performance liquid chromatography. Free lidocaine, MEGX, and GX were separated from 2 mL of plasma by ultrafiltration filter units. Hemodynamic data were similar between groups. The plasma concentrations of free lidocaine were not significantly different between groups. The ratios of free MEGX to free lidocaine and free GX to free MEGX were not different between groups. In conclusion, propofol does not alter the metabolism of epidural lidocaine compared with sevoflurane.     

Leaflet folding plasty combined with annular plication for mitral valve repair

We describe a new technique of mitral valve repair based on two reconstructive techniques: (1) the folding leaflet method, and (2) the classic annular plication. This combination appears to be useful in cases with a large prolapsing posterior mitral leaflet with excessive leaflet height or in cases with commissural prolapse involving both the anterior and posterior leaflets.     

Management of renal angiomyolipomas associated with tuberous sclerosis complex

PURPOSE: Intensive management is generally recommended for angiomyolipomas associated with tuberous sclerosis complex (TSC), which are known to have a more aggressive nature than sporadic tumors. In this study we evaluated the management of these tumors. MATERIALS AND METHODS: The records of 6 men and 6 women with TSC and a mean age of 28.8 years) with angiomyolipomas treated from 1984 to 2000 were retrospectively analyzed. All patients had bilateral multiple tumors (mean size 6.6 cm). There were 10 lesions classified as small (less than 4 cm), 6 medium (4 to 10 cm) and 8 large lesions (10 cm or greater). Computerized tomography was repeated annually for followup observation and semiannually after embolization. RESULTS: Excluding from study 3 tumors treated prophylactically intervention was required in 20%, 50% and 100% of small, medium and large tumors, respectively. Among 14 tumors followed by observation, 8 grew and 4 required intervention. Uncontrollable hemorrhage did not develop in any patient. While some tumors showed remarkable growth in decade 3, growth did not exceed 1.5 cm per year. Embolization was performed in 11 tumors and tumors shrank in 10. Although 1 patient experienced renal atrophy, all patients but 1 are alive without renal failure with a mean followup of 60 months. CONCLUSIONS: Although asymptomatic angiomyolipomas associated with TSC grow gradually, severe hemorrhage is rare and most tumors can be managed conservatively with annual computerized tomography. Embolization is the first choice of intervention but should be reserved until symptoms develop.     

Topical negative pressure using a drainage pouch without foam dressing for the treatment of undermined pressure ulcers

Topical negative pressure is gaining popularity as an acute and chronic wound management technique. In general, foam dressing is applied to the wound surface to maintain negative pressure. Due to the potential for clogging by the foam dressing, topical negative pressure cannot be used when there is a high volume of necrotic tissue or massive infection present. In this study, topical negative pressure was applied using a drainage pouch without any dressing. Topical negative pressure was applied to 8 patients with 9 pressure ulcers complicated by undermining. This approach was effective in the treatment of all 9 ulcers and allowed the wounds to be visualized while maintaining negative pressure. Since this technique can be performed without foam dressing, it can be used to treat early-stage infectious pressure ulcers in which there is a lot of necrotic tissue. CONCLUSION: Topical negative pressure without dressing is an extremely effective treatment of pressure ulcers complicated by undermining.     

Evaluation of efficiency of a semiconductor gamma camera

We evaluation basic characteristics of a compact type semiconductor gamma camera (eZ-SCOPE AN) of Cadmium Zinc Telluride (CdZnTe). This new compact gamma camera has 256 semiconductors representing the same number of pixels. Each semiconductor is 2 mm square and is located in 16 lines and rows on the surface of the detector. The specific performance characteristics were evaluated in the study referring to NEMA standards; intrinsic energy resolution, intrinsic count rate performance, integral uniformity, system planar sensitivity, system spatial resolusion, and noise to the neighboring pixels. The intrinsic energy resolution measured 5.7% as FWHM. The intrinsic count rete performance ranging from 17 kcps to 1,285 kcps was evaluated, but the highest intrinsic count rate was not observed. Twenty percents count loss was recognized at 1,021 kcps. The integral uniformity was 1.3% with high sensitivity collimator. The system planar sensitivity was 33,330 cpm/MBq with high resolution collimator and 766,767 cpm/MBq with high sensitivity collimator. The system spatial resolution (FWHM) was 2.0 mm and 2.2 mm when the distance between source and collimator was 0 cm and 3 cm respectively.     

ESR study of camphorquinone/amine photoinitiator systems using blue light-emitting diodes

New light-activation units equipped with high-illuminant blue light-emitting diodes (LEDs) have recently been proposed as a replacement for the halogen units that are widely used in dentistry to polymerize light-cured resins. The photoinitiators in light-cured dental resins, typified by the camphorquinone (CQ)/amine photoinitiator system, generate primary radicals with light irradiation that attack the double bonds of resin monomers. The physical properties of the cured resins are affected by the generation of primary radicals during the initial stage of polymerization. This study examined two types of photoinitiator systems, CQ/DMPT and CQ/DMAEMA, and three types of curing units, a new LED unit and two conventional halogen units. The primary radicals generated by irradiation were quantified using electron spin resonance (ESR) spectroscopy with a trapping method, using phenyl-tert-butyl nitrone as the trapping agent. The energy efficiencies of the LED and halogen units were compared by quantifying the generated radicals and emitted light energy (J/cm(2)). The energy required to generate a given amount of radicals using the LED unit was smaller than that using the halogen units (p<0.05). These results suggest that the new LED unit performs better than conventional halogen units with respect to light energy.     

Quantitative analyses of expression of GDNF and neurotrophins during postnatal development in rat skeletal muscles

Neurotrophic factors are thought to be critically involved in formation and maintenance of the neuromuscular system. To know precise expression levels of these factors in the muscles during the postnatal period, we developed competitive RT-PCR and two-site enzyme immunoassay and quantitatively measured neurotrophic factors in the rat gastrocnemius and soleus muscles during the postnatal development. mRNAs of glial cell line-derived neurotrophic factor (GDNF) in the gastrocnemius and the soleus muscles were expressed in the highest amount among the neurotrophic factors at birth and dramatically decreased in the first 3 months, while GDNF proteins substantially existed at 3 months of age. Neurotrophin-3 and brain-derived neurotrophic factor in the gastrocnemius muscle kept constant expression in mRNA and protein during the postnatal period. In contrast, mRNA of neurotrophin-4 increased in the first 2 weeks. In the soleus muscles all the neurotrophic factor proteins increased with age for the first month, contrasting with their expressions in the gastrocnemius. The present results showed that GDNF is constitutively supplied to the neuromuscular junction (NMJ) during postnatal development and into adulthood, suggesting its importance in maintenance of the NMJ. Expression of other neurotrophins was also regulated independently during development possibly according to their own roles in the neuromuscular circuit.     

Production of functional platelets by differentiated embryonic stem (ES) cells in vitro

Megakaryocytes and functional platelets were generated in vitro from murine embryonic stem (ES) cells with the use of a coculture system with stromal cells. Two morphologically distinctive megakaryocytes were observed sequentially. Small megakaryocytes rapidly produced proplatelets on day 8 of the differentiation, and large hyperploid megakaryocytes developed after day 12, suggesting primitive and definitive megakaryopoiesis. Two waves of platelet production were consistently observed in the culture medium. A larger number of platelets was produced in the second wave; 104 ES cells produced up to 108 platelets. By transmission electron microscopy, platelets from the first wave were relatively rounder with a limited number of granules, but platelets from the second wave were discoid shaped with well-developed granules that were indistinguishable from peripheral blood platelets. ES-derived platelets were functional since they bound fibrinogen, formed aggregates, expressed P-selectin upon stimulation, and fully spread on immobilized fibrinogen. These results show the potential utility of ES-derived platelets for clinical applications. Furthermore, production of gene-transferred platelets was achieved by differentiating ES cells that were transfected with genes of interest. Overexpression of the cytoplasmic domain of integrin beta3 in the ES-derived platelets prevented the activation of alphaIIbbeta3, demonstrating that this system will facilitate functional platelet studies.     

Insulin allergy; desensitization with crystalline zinc-insulin and steroid tapering

The insulin analogues, aspart and lispro, have been considered safe alternatives for patients with insulin allergy, because of their decreased immunogenicity. However, recent several reports showed that neither of them was completely free from allergic reactions. We also experienced a patient with insulin allergy not only to human regular insulin but also to both of the insulin analogues. Interestingly, the insulin analogues, which readily dissociate from polymer to monomer, induced the most severe allergic reaction among several types of human insulin reagents in the present case. Allergy to crystalline zinc-insulin, the three-dimensional structure of which results in delayed dissociation and absorption, was negative on intradermal tests. However, its large subcutaneous injection caused local allergic reaction. These results suggested that the allergic reaction might depend on the rapidity of insulin monomerization and absorption, and thus that the immunogenic residue of insulin is concealed when insulin is polymerized. Based on the intradermal tests, we speculated that the antigenic epitope might be B30-Thr in the present case. We also report here the modified method of insulin desensitization using crystalline zinc-insulin with prednisolone tapering. This might be a simple and useful treatment for insulin allergy.