Efficacy, safety, and optimal timing of single-trocar video-assisted flexible thoracoscopic debridement under local anesthesia for complicated parapneumonic empyema.

OBJECTIVE: Thoracoscopic debridement under local anesthesia is a useful approach for complicated parapneumonic effusion or empyema (CPE) and is a less invasive procedure than video-assisted thoracoscopic surgery under general anesthesia. There are various methods of thoracoscopic debridement under local anesthesia, although the optimal timing of treatment is unknown. The objective of this study was to verify the efficacy and safety of our video-assisted flexible thoracoscopic debridement (VAFTS-D) procedure under local anesthesia, and to investigate the clinical features associated with the success of VAFTS-D. METHODS: The study included 71 consecutive patients with CPE who underwent VAFTS-D. The primary outcome was success of VAFTS-D. We retrospectively analyzed the efficacy and safety of VAFTS-D from the clinical data obtained from hospital medical records, and used univariate logistic analyses to identify potential predictors of the outcome. RESULTS: VAFTS-D was considered successful in 62 of 71 patients (87.3%). Two of the remaining nine patients died and the other seven patients required subsequent operation under general anesthesia. Complications due to VAFTS-D occurred in six patients (8.5%). Duration of empyema < 10 days (P = 0.024) and negative bacterial culture in pleural effusion (P = 0.029) were independently associated with the success of VAFTS-D by univariate logistic regression analysis. CONCLUSION: VAFTS-D might be an acceptable first-line procedure in patients with suspected CPE. VAFTS-D should be performed as early as possible for a successful outcome, and to obtain useful information on the pleural cavity.

Photodegradation of retinal bisretinoids in mouse models and implications for macular degeneration.

Adducts of retinaldehyde (bisretinoids) form nonenzymatically in photoreceptor cells and accumulate in retinal pigment epithelial (RPE) cells as lipofuscin; these fluorophores are implicated in the pathogenesis of inherited and age-related macular degeneration (AMD). Here we demonstrate that bisretinoid photodegradation is ongoing in the eye. High-performance liquid chromatography (HPLC) analysis of eyes of dark-reared and cyclic light-reared wild-type mice, together with comparisons of pigmented versus albino mice, revealed a relationship between intraocular light and reduced levels of the bisretinoids A2E and A2-glycero-phosphoethanolamine (A2-GPE). Analysis of the bisretinoids A2E, A2-GPE, A2-dihydropyridine-phosphatidylethanolamine (A2-DHP-PE), and all-trans-retinal dimer-phosphatidylethanolamine (all-trans-retinal dimer-PE) also decreases in albino Abca4(-/-) mice reared in cyclic light compared with darkness. In albino Abca4(-/-) mice receiving a diet supplemented with the antioxidant vitamin E, higher levels of RPE bisretinoid were evidenced by HPLC analysis and quantitation of fundus autofluorescence; this effect is consistent with photooxidative processes known to precede bisretinoid degradation. Amelioration of outer nuclear layer thinning indicated that vitamin E treatment protected photoreceptor cells. Conversely, in-cage exposure to short-wavelength light resulted in reduced fundus autofluorescence, decreased HPLC-quantified A2E, outer nuclear layer thinning, and increased methylglyoxal (MG)-adducted protein. MG was also released upon bisretinoid photodegradation in cells. We suggest that the lower levels of these diretinal adducts in cyclic light-reared and albino mice reflect photodegradative loss of bisretinoid. These mechanisms may underlie associations among AMD risk, oxidative mechanisms, and lifetime light exposure.

Minimally invasive (13)C-breath test to examine phenylalanine metabolism in children with phenylketonuria.

BACKGROUND: Phenylketonuria (PKU) is an autosomal recessive disorder caused by deficiency of hepatic phenylalanine hydroxylase (PAH) leading to increased levels of phenylalanine in the plasma. Phenylalanine levels and phenylalanine hydroxylase (PAH) activity monitoring are currently limited to conventional blood dot testing. 1-(13)C-phenylalanine, a stable isotope can be used to examine phenylalanine metabolism, as the conversion of phenylalanine to tyrosine occurs in vivo via PAH and subsequently releases the carboxyl labeled (13)C as (13)CO2 in breath. OBJECTIVE: Our objective was to examine phenylalanine metabolism in children with PKU using a minimally-invasive 1-(13)C-phenylalanine breath test ((13)C-PBT). DESIGN: Nine children (7 M: 2 F, mean age 12.5 ± 2.87 y) with PKU participated in the study twice: once before and once after sapropterin supplementation. Children were provided 6 mg/kg oral dose of 1-(13)C-phenylalanine and breath samples were collected at 20 min intervals for a period of 2h. Rate of CO2 production was measured at 60 min post-oral dose using indirect calorimetry. The percentage of 1-(13)C-phenylalanine exhaled as (13)CO2 was measured over a 2h period. Prior to studying children with PKU, we tested the study protocol in healthy children (n = 6; 4M: 2F, mean age 10.2 ± 2.48 y) as proof of principle. RESULTS: Production of a peak enrichment (Cmax) of (13)CO2 (% of dose) in all healthy children occurred at 20 min ranging from 17-29% of dose, with a subsequent return to ~5% by the end of 2h. Production of (13)CO2 from 1-(13)C-phenylalanine in all children with PKU prior to sapropterin treatment remained low. Following sapropterin supplementation for a week, production of (13)CO2 significantly increased in five children with a subsequent decline in blood phenylalanine levels, suggesting improved PAH activity. Sapropterin treatment was not effective in three children whose (13)CO2 production remained unchanged, and did not show a reduction in blood phenylalanine levels and improvement in dietary phenylalanine tolerance. CONCLUSIONS: Our study shows that the (13)C-PBT can be a minimally invasive, safe and reliable measure to examine phenylalanine metabolism in children with phenylketonuria. The breath data are corroborated by blood phenylalanine levels in children who had increased responses in (13)CO2 production, as reviewed post-hoc from clinical charts.

Single-trocar thoracoscopy under local anesthesia for pleural space infection.

OBJECTIVE: The role of single-trocar thoracoscopy for complicated parapneumonic effusion (CPE) and pleural empyema is not established as yet. The aim of this study was to report our experience and analyze the efficacy and safety of debridement by single-trocar thoracoscopy for the patients with CPE and multiloculated empyema. METHODS: We performed a retrospective study reviewing the medical records of the patients treated parapneumonic effusion and multiloculated empyema by single-trocar thoracoscopy under local anesthesia at our department from January 2000 to December 2012. RESULTS: A total 29 patients with CPE and multiloculated empyema were treated by single-trocar thoracoscopy. As the staging of pleural infection, class 5 and class 7 by Light classification were 21 and 8 patients, respectively. The onset of the symptom was on average 13.9 ± 11.7 days before the procedure. This procedure was successful in 23 of 29 patients (79.3%) without further operation under general anesthesia. Complication occurred in 1 case of 29 patients (3.4%). Six patients required subsequently the operation under general anesthesia, and one of the 6 patients died to multiple organ failure caused by sepsis. A microbiological diagnosis could be made in fifteen patients (51.7%). CONCLUSIONS: Debridement by single-trocar thoracoscopy can be an acceptable approach as the first-line procedure in patients with CPE and empyema. This procedure can provide not only appropriate and expeditious treatment but also information of pleural cavity to decide indication for thoracotomy under general anesthesia.