A new technique of continuous pleural irrigation with minocycline administration for refractory chylothorax.

Chylothorax is a rare and serious complication of thoracic surgery and can lead to respiratory insufficiency, protein loss, fluid imbalance, and immunodeficiency. Chylothorax is often difficult and complex to manage. Although multiple approaches for the treatment of chylothorax have been reported, there is still no clear consensus on its optimal management. A surgical approach involving careful dissection and clipping of lymphatic vessels can help effectively manage chylous fistula in a majority of cases. Occasionally, chyle leak may not be apparent during surgery, and thus ligation of the bed of the thoracic duct may not be sufficient to stop the chyle leak. We report here on 3 patients with chylothorax in whom pleurodesis was successfully achieved via continuous intrapleural irrigation with minocycline (800 mg minocycline and 800 mg of 2 % lidocaine hydrochloride in 1000 mL normal saline, set to 100 mL per hour) instead of conventional intermittent pleurodesis.

Surface coverage effects on the desorption kinetics of selenite from a hydroxyaluminum-montmorillonite complex.

Information on the desorption of metals and metalloids from soils and clays are essential for a better understanding of their mobility, transport, and fate in natural environments. We investigated nitrate-, phosphate-, and citrate-induced desorption kinetics of preadsorbed selenite (presented as Se henceforth) from a hydroxyaluminum-montmorillonite (HyA-Mt) complex at three different surface coverages of 8%, 25%, and 69% of its Langmuir predicted adsorption maximum (262.61 mmole kg(-1)). Generally the mole fraction of preadsorbed Se released after the attainment of desorption equilibrium was significantly higher with increasing surface coverage. Desorption kinetics of Se from the clay was best described by the Elovich model. The Elovich model parameter beta representing the rate of Se desorption increased as the surface coverage increased. Both kinetic data and mole fraction of Se released at desorption equilibrium supported the contention that adsorption bond strength progressively decreases with increasing surface coverage. Both citrate and phosphate remobilized Se at significantly faster rates than nitrate at any surface coverage level. Citrate showed a significantly faster rate of Se release than phosphate only at 8% surface coverage but not at 25% and 69% surface coverages, suggesting that differential ability of these two ligands to influence the kinetics of Se release was also surface coverage dependent. The findings of the present study would help better understand the consequences of different surface coverages on soil colloids by preadsorbed Se as well as the impacts of phosphate fertilization and rhizospheric processes in influencing Se mobility in soil and related environments.

Chromate reduction by zero-valent Al metal as catalyzed by polyoxometalate.

In spite of a high reduction potential of zero-valent Al (ZVAl), its ability to reduce Cr(VI), a widespread pollutant, to less toxic Cr(III) remains to be uncovered. In the present study, Cr(VI) reduction by ZVAl was conducted to evaluate the potential application of Al as a reductant for Cr(VI). Polyoxometalate (POM, HNa(2)PW(12)O(40)), a catalyst, was used to accelerate Cr(VI) reduction by Al. The reaction of 0.192mM Cr(VI) on ZVAl was investigated in the presence of N(2) or O(2) at pH 1. A slight decrease in Cr(VI) concentration was observed on as-received (uncleaned) ZVAl due to the presence of oxide layer with a low surface area (ca. 3.4x10(-3)m(2)/g) of ZVAl. On addition of 0.1mM POM, Cr(VI) reduction on uncleaned ZVAl increased significantly. This is attributed to the unique properties of POM, which has a Brphinsted acidity higher than usual inorganic acids such as H(2)SO(4) and HCl. Thus, POM could remove rapidly the oxidize layer on ZVAl, followed by acting as a shuttle for electron transfer from ZVAl to Cr(VI). Under a N(2) atmosphere, one- or two-electron reduction of POM by ZVAl was responsible for Cr(VI) reduction in the early stage of the reaction. However, during reaction with ZVAl over 120min, three-electron reduction of POM predominated over Cr(VI) reduction. On interaction of O(2) with reduced POM, the formation of H(2)O(2) was responsible for subsequent Cr(VI) reduction. The results suggest that POM is an efficient catalyst for Cr(VI) reduction by Al due to the extremely rapid consumption of reduced POM or H(2)O(2) by Cr(VI).

Evaluation of intraoperative cardiovascular responses to closed repair for pectus excavatum.

OBJECTIVE: Closed repair of pectus excavatum (PE), also known as the Nuss procedure, has become more popular recently, and whether this operation results in true cardiac improvement as opposed to postoperative physical rehabilitation or a psychological effect deserves examination. METHODS: Ten PE patients (8 males, 2 females) aged 4 to 54 years (average, 19.6+/-14 years) were prospectively evaluated using preoperative computed tomography (CT) scan, pulmonary function studies, electrocardiogram and transthoracic echocardiographic (TTE) evaluation of cardiac function. The same studies were repeated at 3 months post bar placement. In addition, intraoperative transesophageal echocardiogram (TEE) was done to measure the procedure-related values of the cardiac chamber and functional indices before and after turning of the pectus bar. RESULTS: Statistically significant changes in the pectus index, obtained by dividing the internal transverse distance of the thorax by the vertebral-sternal distance at the most depressed portion of the deformity, were noted after surgery, decreasing from 5.06+/-1.46 to 3.55+/-0.48 (P<0.05). Most patients with previously abnormal electrocardiograms showed a normal pattern after surgical repair (P<0.05). Five subjects in the PE group (50%) showed mitral valve prolapse in TTE and 4 of them had mitral regurgitation. However, these valve patterns could not be corrected after surgical repair of the chest wall deformity (P=0.25). The cardiac chamber and the function of the right ventricle were evaluated by intraoperative TEE and showed significantly increased values after retrosternal dissection and post-turning of the pectus bar. CONCLUSION: The data of this study supports the concept that closed repair directly contributes to hemodynamic improvement.

Modified Nuss operation for pectus excavatum: design for decreasing cardiopulmonary complications.

BACKGROUND: Thoracoscopic Nuss operation of funnel chest is increasingly performed. However, it has a high rate of complications. This study developed some modifications to facilitate Nuss operations with the intention of reducing several major complications. METHODS: Patients who presented for surgical repair of pectus excavatum from July 2003 through June 2004 had a preoperative computed tomography (CT) scan, pulmonary function tests, and cardiac echo before and two months after the modified Nuss operation. The following modifications of the standard Nuss procedure were implemented: (1) One small subxyphoid incision was made to guide the plate implantation and to decrease cardiopulmonary complications. (2) Thoracic muscles were dissected off the ribs to provide muscle pockets. (3) Shorter thick stainless-steel AO bars were selected to avoid thoracic outlet syndrome and restriction. (4) The bars were fixed to adjacent ribs by 4-0 stainless steel wires into the submuscular pockets. (5) No thoracoscope routinely used. (6) No chest tubes were placed to decrease chest pain or for cosmetic purposes. RESULTS: 15 patients aged between 4 and 32 years (mean, 18.6 +/- 7.8) underwent evaluation. Preoperative CT index was 4.14 +/- 0.86. The average operating time was 95.7 +/- 27.0 min. There was no bar dislocation, prolonged pain, or neuralgia. Echocardiography showed no pericarditis and no pneumothorax occurred after placement of the intrathoracic bar. CONCLUSION: A small subxiphoid incision makes bar implantation easier and has reduced the incidence of major complications in this early experience with 15 patients.

Thoracoscopic diaphragmatic repair for refractory hepatic hydrothorax: application of pleural flap and mesh onlay reinforcement.

BACKGROUND: Management of hepatic hydrothorax is difficult, and no radical treatment has been established. Based on accumulating evidence that diaphragmatic defects contribute to hepatic hydrothorax, we developed a diaphragmatic repair method for the management of this complex condition. METHODS: From October 2003 to March 2005, 10 patients (age, 32 - 83 years; 6 men and 4 women) with refractory hepatic hydrothorax (Child-Pugh class B-C) underwent thoracoscopic pleura (n = 7) or mesh (n = 3) onlay reinforcement to repair the diaphragmatic defects on which this study focuses, and all patients have since been under follow-up in a prospective observation study. RESULTS: After a mean of 7.7 months of follow-up examinations, no local recurrence occurred in all patients. Two patients died of hemorrhage from esophageal varices two months postoperatively. All patients had a better postoperative pulmonary function. CONCLUSION: The use of pleura and mesh onlay reinforcement of the diaphragm is an encouraging treatment for refractory hepatic hydrothorax.

Full thickness skin graft as an adjunct in the repair of a recurrent benign tracheoesophageal fistula.

Recurrent nonmalignant tracheoesophageal fistula (TEF) is a rare problem and is usually associated with high postoperative death. Operative closure of TEF should be attempted in each case, because spontaneous closure is rare. Due to the rarity of these lesions, there are no data on the superiority of the various surgical options in repairing recurrent TEF. The management of this complication is particularly difficult since there is no adequate muscle to separate the tracheal wall and the esophageal suture to help prevent recurrent TEF. We describe a treatment modality of repair of a recurrent postintubation TEF treated by a full thickness skin graft between the trachea and esophagus. This technique yields good clinical results and warrants consideration for the treatment of TEF when other conventional techniques cannot be used.

A precious experience of lobar transplantation in a teenager with end-stage chronic hypersensitivity pneumonia: case report.

Pulmonary fibrosis inevitably develops in patients with chronic hypersensitivity pneumonia (CHP). Lobar transplantation may be a viable option for pediatric and small adult patients with end-stage CHP and life-threatening respiratory decompensation. We describe a 16-year-old girl experiencing end-stage pigeon breeder's hypersensitivity pneumonia with right heart failure, who received left allograft lobar transplantation and had an uneventful convalescent course for 1 year after transplantation. Histopathologically the excised native lung revealed diffuse infiltration of lung parenchyma by CD3+ and CD8+ cells with an absence of CD4+ cells, whereas T-lymphocyte subsets analysis revealed no abnormalities in the blood. This finding is consistent with the contribution of a local type IV immune reaction to the pathogenesis. In addition, the observation of specific cellular distribution of bronchus-associated lymphoid tissue suggests that chronic antigenic stimulation and /or inflammation in CHP may cause bronchus-associated lymphoid tissue development, which is likely to play an important role in the mucosal immune response of this disease.

Formation of protein-birnessite complex: XRD, FTIR, and AFM analysis.

Limited information is available on formation chemistry of enzyme-Mn oxide complexes. Adsorption isotherm of protein molecules (tyrosinase) on birnessite (delta-MnO(2)) at pH 6.0 and room temperature (23 degrees C) was of H type, indicating a very high affinity of the enzyme protein molecules to the birnessite mineral surfaces. After thorough washing of the protein-mineral complex with deionized-distilled water, up to 89% of adsorbed protein molecules remained bound to the mineral surfaces. When a high amount of the protein was immobilized, the X-ray diffractogram shows a significant decrease in the intensity of characteristic d-spacings of birnessite. No shift to higher values of the d-spacings of protein-birnessite complex was observed, indicating that the enzyme molecules were not intercalated in the mineral structure but immobilized at the external surfaces and the edges of the mineral oxide. By comparison to the free enzyme, infrared absorption spectra of the protein-birnessite complexes show a shift by up to 11 cm(-1) to lower frequencies in the absorption bands characteristic of amide I and II modes of the polypeptides chains. The mineral surfaces exerted some strain on the protein structure, resulting in an alteration of the protein molecular conformation after binding to the mineral colloid surfaces. In the free state, the globular protein molecules had a spheroid shape with an average cross-sectional diameter of 70+/-6 nm. The unfolding and flattening of the protein molecules after immobilization is clearly shown in atomic force micrographs. Compared to the tyrosinase-birnessite complex, similar FTIR spectra and atomic force micrographs were observed for the pure protein, bovine serum albumin (BSA), after immobilization on birnessite. The information obtained in this study is of fundamental significance for understanding birnessite as an adsorbent of biopolymers and the catalytic role of the enzyme-birnessite complex.

Molecular shape analysis of a Maillard reaction intermediate.

The Maillard (browning) reaction involving the polycondensation of sugars and amino acids is believed to be an important abiotic pathway for humic substance formation in nature. However, a major drawback is that the Maillard reaction is extremely slow at temperatures encountered under normal environmental conditions. In order to elucidate some details of this process molecular shape analysis was applied to investigate the initial reaction between D-glucose and glycine to form the Amadori compound fructosylglycine which is an intermediate product in the Maillard reaction. The structure of the Amadori compound was optimized at a quantum mechanical level and its ground state electron energy calculated. Molecular Iso-Density Contours (MIDCO's), electron density contour surfaces of constant electron density, were constructed for D-glucose, glycine and fructosylglycine in order to study the steric conditions for the reaction. The calculations indicate that the Amadori compound and water on one hand and the separate entities D-glucose and glycine on the other hand are very similar to each other in terms of their ground state energy. This agrees with the experimental observation that the reaction between D-glucose and glycine to form the Amadori compound is slow.

Accuracy of ED sonography in the diagnosis of acute appendicitis.

The objective was to compare the accuracy of abdominal sonography performed by emergency physicians in the diagnosis of acute appendicitis with that of the surgeons' clinical impression. Three hundred-seventeen patients with right lower abdominal pain admitted to the Department of Emergency Medicine at National Taiwan University Hospital in Taipei, Taiwan were prospectively included in this study. Patients were divided into two groups according to the time of day they visited the emergency department. Those patients visiting the emergency department during the day were included in group I and those during the night were in group II. Group I was diagnosed by sonography. Group II was diagnosed by surgeons' clinical impression without sonographic examination. The definitive diagnosis of acute appendicitis was confirmed by the pathological reports. In the diagnosis of acute appendicitis, group I had a sensitivity of 96.4%, a specificity of 67.6%, a positive predictive value of 89.8%, a negative predictive value of 86.2%, and an accuracy of 89.1%, and group II had a sensitivity of 86.2%, a specificity of 37.0%, a positive predictive value of 74.6%, a negative predictive value of 55.6%, and an accuracy of 70.6%. The overall accuracy of sonography performed by emergency physicians in the diagnosis of acute appendicitis was superior to that of the surgeons' clinical impression.

Bioavailability of organic and inorganic phosphates adsorbed on short-range ordered aluminum precipitate.

A nonreductive community-level study of P availability was conducted using various forms of adsorbed P. Orthophosphate (Pi), inositol hexaphosphate (IHP), and glucose 6-phosphate (G6P) were adsorbed to a short-range ordered Al precipitate. These bound phosphates provided a P source sufficient to support the growth of microbial communities from acidic Brazilian soils (oxisols). Adsorbed IHP, the most abundant form of organic phosphate in most soils, had the lowest bioavailability among the three phosphates studied. Adsorbed G6P and Pi were almost equally available. The amount of adsorbed Pi (1 cmol P kg(-1)) required to support microbial growth was at least 30 times less than that of IHP (30 cmol P kg(-1)). With increased surface coverage, adsorbed IHP became more bioavailable. This availability was attributed to a change in the structure of surface complexes and presumably resulted from the decreased number of high-affinity surface sites remaining at high levels of coverage. It thus appears that the bioavailability of various forms of adsorbed phosphate was determined primarily by the stability of the phosphate-surface complexes that they formed, rather than by the total amount of phosphate adsorbed. IHP, having the potential to form stable multiple-ring complexes, had the highest surface affinity and the lowest bioavailability. Bioaggregates consisting of bacteria and Al precipitate were observed and may be necessary for effective release of adsorbed P. Bacteria in the genera Enterobacter and Pseudomonas were the predominate organisms selected during these P-limited enrichments.

Effects of chemical speciation in growth media on the toxicity of mercury(II).

The toxicity of metals, including mercury, is expressed differently in different media, and the addition of soluble organics to the growth medium can have a significant impact on bioassay results. Although the effect of medium composition on metal toxicity is generally attributed to its effect on metal speciation (i.e., the chemical form in which the metal occurs), the importance of individual metal-ligand species remains largely unclear. Here, we report the results of a study that investigated, both experimentally and from a modeling perspective, the effects of complex soluble organic supplements on the acute toxicity (i.e., 50% inhibitory concentration [IC50]) of mercury to a Pseudomonas fluorescens isolate in chemically well-defined synthetic growth media (M-IIX). The media consisted of a basal inorganic salts medium supplemented with glycerol (0.1%, vol/vol) and a variety of common protein hydrolysates (0.1%, vol/vol), i.e., Difco beef extract (X = B), Casamino Acids (X = C), peptone (X = P), soytone (X = S), tryptone (X = T), and yeast extract (X = Y). These were analyzed to obtain cation, anion, and amino acid profiles and the results were used to compute the aqueous speciation of Hg(II) in the media. Respirometric bioassays were performed and IC50s were calculated. Medium components varied significantly in their effects on the acute toxicity of Hg(II) to the P. fluorescens isolate. IC50s ranged from 1.48 to 14.54 micrograms of Hg ml-1, and the acute toxicity of Hg(II) in the different media decreased in the order M-IIC >> M-IIP > M-IIB >> M-IIT > M-IIS >>> M-IIY.(ABSTRACT TRUNCATED AT 250 WORDS)

Biotoxicity of mercury as influenced by mercury(II) speciation.

Integration of physicochemical procedures for studying mercury(II) speciation with microbiological procedures for studying the effects of mercury on bacterial growth allows evaluation of ionic factors (e.g., pH and ligand species and concentration) which affect biotoxicity. A Pseudomonas fluorescens strain capable of methylating inorganic Hg(II) was isolated from sediment samples collected at Buffalo Pound Lake in Saskatchewan, Canada. The effect of pH and ligand species on the toxic response (i.e., 50% inhibitory concentration [IC50]) of the P. fluorescens isolated to mercury were determined and related to the aqueous speciation of Hg(II). It was determined that the toxicities of different mercury salts were influenced by the nature of the co-ion. At a given pH level, mercuric acetate and mercuric nitrate yielded essentially the same IC50s; mercuric chloride, on the other hand, always produced lower IC50s. For each Hg salt, toxicity was greatest at pH 6.0 and decreased significantly (P = 0.05) at pH 7.0. Increasing the pH to 8.0 had no effect on the toxicity of mercuric acetate or mercuric nitrate but significantly (P = 0.05) reduced the toxicity of mercuric chloride. The aqueous speciation of Hg(II) in the synthetic growth medium M-IIY (a minimal salts medium amended to contain 0.1% yeast extract and 0.1% glycerol) was calculated by using the computer program GEOCHEM-PC with a modified data base. Results of the speciation calculations indicated that complexes of Hg(II) with histidine [Hg(H-HIS)HIS+ and Hg(H-HIS)2(2+)], chloride (HgCl+, HgCl2(0), HgClOH0, and HgCl3-), phosphate (HgHPO4(0), ammonia (HgNH3(2+), glycine [Hg(GLY)+], alanine [Hg(ALA)+], and hydroxyl ion (HgOH+) were the Hg species primarily responsible for toxicity in the M-IIY medium. The toxicity of mercuric nitrate at pH 8.0 was unaffected by the addition of citrate, enhanced by the addition of chloride, and reduced by the addition of cysteine. In the chloride-amended system, HgCl+, HgCl2(0), and HgClOH0 were the species primarily responsible for observed increases in toxicity. In the cysteine-amended system, formation of Hg(CYS)2(2-) was responsible for detoxification effects that were observed. The formation of Hg-citrate complexes was insignificant and had no effect on Hg toxicity.

Spectrophotometric determination of Fe(II) with 2,4,6-tri(2'-pyridyl)-1,3,5-triazine in the presence of large quantities of Fe(III) and complexing ions.

A spectrophotometric method for the determination of Fe(II) in the presence of large amounts (up to 800 mg/l.) of Fe(III) is suggested. The Fe(III) is effectively masked by complexing with fluoride at pH 2.0-2.4 before development of the violet Fe(II) complex with 2,4,6-tri(2'-pyridyl)-1,3,5-triazine. The absorbance is measured at 595 nm. Various commonly occurring ions which complex with Fe(II) and/or Fe(III) do not interfere.

Aluminum of acid soils in the food chain and senility.

Aluminum is liberated from aluminosilicates of soil clays and protracted Al intake by humans in food and medications has been shown to be a potential hazard to human health. Encephalopathology, senility, and lower statistical longevity were found to be geographically and geochemically linked to acid soil conditions. We examined the interrelation of soil environmental supply of Al3+(6H2O) to the food-plant-animal-human chain (e.g., in tea leaves, approximately 1000 mg L-1) and to identified health hazards. Because F forms a strong ligand with Al, we also analyzed the extent that F accumulation is associated with Al accumulation in plants such as tea. Food and medicinal intake of Al needs to be considered in relation to kidney weakness and Al accumulation in humans. Acid soil and plant management could be modified to reduce the hazard of Al in senile dementia (2 to 4 percent of persons age greater than 65 years) and in diseases of the central nervous system endemic in certain acid soil areas.