Kinetics and inhibition during the decolorization of reactive anthraquinone dyes under methanogenic conditions.

The objective of this study was to assess the biological decolorization of two reactive anthraquinone dyes (Reactive Blue 4, RB 4; Reactive Blue 19, RB 19) under methanogenic conditions. Using a mixed, methanogenic culture, batch assays were performed to evaluate both the rate and extent of color removal as well as any potential inhibition. The effect of initial dye, biomass, and organic feed concentration, as well as the effect of repetitive dye addition on color removal kinetics and culture inhibition were assessed. Overall, a lower rate and extent of color removal was observed in RB 4-amended cultures as opposed to the RB 19-amended cultures. For an incubation time of ca. 15 days and an initial dye concentration of 2000 mg/L, the extent of color removal was 50 and 95% for RB 4 and RB 19, respectively. Inhibition of acidogenesis and to a larger degree of methanogenesis, resulting in accumulation of volatile fatty acids, was observed in both RB 4- and RB 19-amended cultures. Although the degree of inhibition varied among the two dyes tested (RB 19 was more inhibitory than RB 4), an increase of inhibition was observed with increasing initial dye concentration. At an initial dye concentration of 500 mg/L or higher, methane production was lower than 6% of that of the control culture for both RB 4 and RB 19. However, color removal occurred despite culture inhibition.

The beneficial hemodynamic effects of selective patent vertical vein following repair of obstructed total anomalous pulmonary venous drainage in infants.

OBJECTIVES: Postoperative low cardiac output may persist after repair of total anomalous pulmonary venous drainage (TAPVD) because of a relatively small and non-compliant left atrium and left ventricle. We examined the effects of selective vertical vein patency on postoperative hemodynamics. METHODS: Thirty-four patients less than 3 months of age with TAPVD were operated from July 1993 to June 2000. The mean age at operation was 21+/-8 days (range, 3-62 days) and the mean weight was 3+/-0.2 kg (range, 2-4.1 kg). Supracardiac type drainage was found in 12 (35%), cardiac in three (9%), mixed in one (3%), and infracardiac in 18 (53%) patients. Twenty-two patients (65%) had obstructed venous drainage. All operations were performed with deep hypothermic circulatory arrest. Supracardiac, mixed and infracardiac types were repaired through a posterior approach, whereas, in the cardiac type, the coronary sinus was unroofed and the atrial septal defect was patched. The decision whether to keep the vertical vein open was made at the end of the operation and was based on the hemodynamic state of the patient. RESULTS: There were no operative deaths. The suture on the vertical vein was released in 22 patients who had obstructed pulmonary venous drainage (infracardiac type, n=18; supracardiac type, n=3; and mixed type, n=1), resulting in a significant drop in the left atrial pressure from 19+/-2 to 12+/-2 mmHg (P<0.05), and in the mean pulmonary artery pressure from 42+/-6 to 35+/-3 mmHg (P<0.05), associated with an immediate increase in the mean arterial blood pressure from a mean of 46+/-3 to 60+/-4 mmHg (P<0.05). During a mean follow-up of 38+/-6 months (range, 8-71 months), there were no late deaths. Follow-up, two-dimensional echocardiography with Doppler studies demonstrated good left ventricular function and trivial or no left to right shunt through the vertical vein in those patients in whom the snare was released. CONCLUSIONS: Maintaining the vertical vein patent in a selective group of patients with infracardiac total anomalous venous drainage contributes to a favorable outcome following surgery.

Surgical management of tetralogy of Fallot in the first year of life.

BACKGROUND: The surgical approach to tetralogy of Fallot (TOF) continues to evolve and now many centers favor early repair for TOF. METHODS: Our experience includes 82 consecutive patients less than 1 year old with TOF (n = 74) and TOF with pulmonary atresia (n = 8) who were operated on between January 1992 and March 1998. Mean age at repair was 5.2 +/- 1.2 months and mean weight was 4.5 +/- 0.4 kg. Seven patients (anomalous left anterior descending artery [n = 1], pulmonary atresia with hypoplastic pulmonary arteries [n = 6]), underwent palliative procedures in the neonatal period followed by complete repair. Forty-nine patients (59%) were symptomatic (severe cyanosis or hypoxic spells), and 33 patients (41%) were asymptomatic. A combined transatrial-transpulmonary approach was employed in 28 patients (34%), and transannular patch or conduit for reconstruction of the right ventricular outflow tract (RVOT) was required in 54 patients (66%). The mean Nakata index was 160 +/- 25 mm2/m2. RESULTS: There were no hospital deaths. Mean post-repair peak right ventricular/systemic pressure ratio was 0.48 +/- 0.1. There were no late deaths or reoperations during a mean follow-up of 23 +/- 5 months. All patients are currently asymptomatic and in New York Heart Association class 1. Postoperative evaluation by two-dimensional and Doppler echocardiography or cardiac catheterization showed minimal pulmonary artery stenosis with a mean pressure gradient of 15 +/- 6 mm Hg across the RVOT. CONCLUSIONS: Our experience suggests that early repair of TOF can yield excellent results and initial palliation does not preclude early complete repair.

Accuracy of flexible fiberoptic endoscopy in identifying abnormal endotracheal tube positions.

This study was carried out to investigate the accuracy of a simple, nonmaneuverable, flexible fiberoptic catheter in identifying both normal and abnormal endotracheal tube (ETT) positions. In addition, the utility of flexible fiberoptic endoscopy (FFE) for ETT position determination in inexperienced hands was examined. One adult dog was sedated and instrumented in the esophagus and trachea with identical ETTs. Four possible ETT positions (trachea, carina, bronchus, esophagus) were randomly assigned. One investigator positioned the ETT into the assigned position by fluoroscopy. Four other blinded investigators were asked to determine the ETT position using the fiberoptic catheter. Each blinded investigator was given 15 seconds to complete the examination and record the ETT position. Randomization resulted in 25 ETT positions examined by each of the four blinded investigators for a total of 100 FFE determinations. FFE ETT determination was correct in 97% of the examinations. All esophageal intubations were correctly identified. Two tracheal locations were misdiagnosed as carina and bronchial, while one carinal location was incorrectly judged as tracheal. The sensitivity of FFE ETT localization was 91.7%, and the specificity was 98.6%. There was no difference in performance by investigator training level or endoscopy experience. We conclude that FFE is a rapid and accurate method for determining both normal and abnormal ETT locations. ETT position determination can be confidently performed by health professionals with minimal training.

Synovial osteochondromatosis.

Synovial osteochondromatosis is a benign disorder in which cartilaginous loose bodies develop about the large joints, usually the knee. It is caused by synovial metaplasia of unknown etiology. Symptoms are due either to mechanical problems caused by the loose bodies or to the degenerative arthritis that usually follows in several years. Surgical or arthroscopic removal of the loose bodies appears to be the only effective treatment. Loose bodies may recur, necessitating synovectomy.

Randomized single-blind clinical trial of a rapid colonic lavage solution (Golytely) vs. standard preparation for barium enema and colonoscopy.

A randomized single-blind clinical trial was conducted to compare the effectiveness and acceptance by patients of a new oral balanced lavage solution with those of a standard preparation for cleansing the colon for barium enema (50 patients) and colonoscopy (20 patients). The quality of preparation was comparable for the 2 preparations. For colonoscopy, Golytely preparation resulted in slightly better results than standard preparation. Patient acceptance was comparable for the 2 preparations. We conclude that Golytely can be used as an alternative to standard preparation for barium enema. For colonoscopy, it is slightly superior to standard preparation.