Grain sorghum is a viable feedstock for ethanol production.

Sorghum is a major cereal crop in the USA. However, sorghum has been underutilized as a renewable feedstock for bioenergy. The goal of this research was to improve the bioconversion efficiency for biofuels and biobased products from processed sorghum. The main focus was to understand the relationship among "genetics-structure-function-conversion" and the key factors impacting ethanol production, as well as to develop an energy life cycle analysis model (ELCAM) to quantify and prioritize the saving potential from factors identified in this research. Genetic lines with extremely high and low ethanol fermentation efficiency and some specific attributes that may be manipulated to improve the bioconversion rate of sorghum were identified. In general, ethanol yield increased as starch content increased. However, no linear relationship between starch content and fermentation efficiency was found. Key factors affecting the ethanol fermentation efficiency of sorghum include protein digestibility, level of extractable proteins, protein and starch interaction, mash viscosity, amount of phenolic compounds, ratio of amylose to amylopectin, and formation of amylose-lipid complexes in the mash. A platform ELCAM with a base case showed a positive net energy value (NEV) = 25,500 Btu/gal EtOH. ELCAM cases were used to identify factors that most impact sorghum use. For example, a yield increase of 40 bu/ac resulted in NEV increasing from 7 million to 12 million Btu/ac. An 8% increase in starch provided an incremental 1.2 million Btu/ac.

Exercise capacity in children with hypertrophic cardiomyopathy and its relation to diastolic left ventricular function.

Left ventricular diastolic impairment is often seen in children with hypertrophic cardiomyopathy regardless of left ventricular outflow tract obstruction. Such impairment in diastolic filling is related to the presence of symptoms and exercise impairment.

Blade and balloon atrial septostomy for left heart decompression in patients with severe ventricular dysfunction on extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) is used as circulatory support or bridge to transplantation in patients with severe left ventricular (LV) dysfunction. Left heart decompression is needed to reduce pulmonary edema, prevent pulmonary hemorrhage, and reduce ventricular distention that may aid in recovery of function. We reviewed our experience from November 1993 to December 1997 with 10 patients having severe LV dysfunction (7 myocarditis, 3 dilated cardiomyopathy) who required circulatory support with ECMO and who underwent left heart decompression with blade and balloon atrial septostomy (BBAS). Patients ranged in age from 1 to 24 years (median, 3 years). Indications for BBAS included left atrial/left ventricular distension (10), pulmonary edema/hemorrhage (9), or severe mitral regurgitation (2). BBAS was performed electively in eight patients and urgently in two patients. BBAS was performed while on ECMO in seven patients and pre-ECMO in three. A femoral venous approach was used in all patients. ECMO patients were fully heparinized. Transseptal puncture was required in nine patients while one patient had a patent foramen ovale. Blade septostomy was performed in all patients. Enlargement of the defect was then performed by stationary balloon dilation in nine and Rashkind balloon atrial septostomy in one. Balloon diameters ranged from 10 to 20 mm. Sequential balloon inflations were performed in some patients. Adequacy of the atrial septal defect (ASD) was confirmed by pressure measurement and echocardiography. Adequate left heart decompression was achieved in all patients. Pulmonary edema improved in nine of nine patients. Left atrial mean pressure fell from a mean of 30.5 mm Hg, (range, 12-50 mm Hg) to 16 mm Hg (range, 9-24 mm Hg). Left atrial to right atrial pressure gradient fell from a mean of 20 mm Hg pre-BBAS to 3 mm Hg post-BBAS. ASDs ranged in size from 2.5 to 8 mm (mean, 5.9 mm). Complications included needle perforation of the left atrium without hemodynamic compromise (one), ventricular fibrillation requiring defibrillation (one), and hypotension following BBAS which responded to volume infusion (two). Duration of ECMO ranged from 41 hr to 704 hr (mean, 294 hr). Seven patients survived and four patients had recovery of normal LV function. Of those who recovered, two had no ASD at follow-up while two ASDs are patent 14 days and 3 months post-BBAS. Three patients underwent successful cardiac transplantation. Three patients died, all of whom had multisystem organ failure with or without sepsis. A patent ASD was noted at transplant (three) or autopsy (two). No patient required a second BBAS. BBAS alleviates severe left atrial hypertension and pulmonary edema. In addition, BBAS avoids the potential bleeding complications of surgical left heart decompression. Stationary balloon dilation of the atrial septum is an effective alternative to Rashkind balloon septostomy in older patients. BBAS achieves left heart decompression that may permit recovery of LV function or allow extended ECMO support as a bridge to transplant.

Influence of diurnal blood pressure variations on target organ abnormalities in adolescents with mild essential hypertension.

As hypertensive target-organ damage has been associated with diminished diurnal blood pressure (BP) variation in adults, we compared diurnal BP patterns of hypertensive adolescents with left ventricular hypertrophy with normotensive and hypertensive adolescents with normal left ventricular mass. In addition, the frequency of microalbuminuria (Malb), hyperfiltration, and reduced renal functional reserve (RFR) was evaluated in adolescents with normal BP and untreated borderline and mild essential hypertension. Thirty-three normotensive (NT) adolescents, 14.5+/-2.1 years (mean +/- SD), and 29 untreated borderline and mildly hypertensive (HT) adolescents, 14.6+/-2.4 years, wore the SpaceLabs 90207 ambulatory BP monitor for 24 h. Left ventricular mass was measured by M-mode echocardiography and then indexed (LVMI) to the cube of height. Creatinine clearance (Clcr) and urine Malb was measured on 24 h collection and RFR by change in creatinine clearance after an oral protein load. Diurnal BP change was expressed as the absolute and percent day-night BP fall and cusum derived plot height (CPH) and circadian alteration magnitude (CDCAM). Groups were compared using analysis of covariance with adjustments for race, gender, and body mass index. All NT and 19 HT subjects (HT-1) had normal LVMI at 22.2+/-5.3 and 25.8+/-3.8 g/m3, respectively. Ten HT (HT-2) had increased LVMI of 36.9+/-5.2 g/m3. No significant difference was found for absolute or percent day-night BP fall or CDCAM between groups. Nocturnal systolic BP was correlated most closely with LVMI (r = 0.41, p = .001). Clcr, Malb, and RFR did not differ between the groups. In conclusion, adolescents with borderline and mild essential hypertension and left ventricular hypertrophy have similar levels of diurnal BP fall, urine Malb excretion, and RFR compared to normotensive and hypertensive adolescents with normal left ventricular mass.

Prolonged extracorporeal life support for bridging to transplant: technical and mechanical considerations.

Through July 1995, the Extracorporeal Life Support Organization (ELSO) registry listed 87 patients who received extracorporeal life support (ECLS) as a bridge to cardiac transplantation with a survival rate of 41%. At Arkansas Children's Hospital, 17 patients (aged between two days and 24 years) with diagnoses of dilated cardiomyopathy (seven), postcardiotomy (seven) and acute viral myocarditis (three) were bridged with ECLS. Mechanical complications only occurred in two patients, neither of which necessitated withdrawal of ECLS. Decompression of the left heart was performed in 11 patients, six via a surgically placed vent and five with a blade/balloon artial septostomy. Documented infection occurred in 11/17 patients, but only one patient died from infection. Fifteen of 17 patients (88%) recovered or were transplanted, of which 13 (76%) were discharged home. With left-heart decompression and appropriate treatment of infection, ECLS may be used as a bridge to cardiac transplantation or until the return of cardiac function.

Infection after pediatric heart transplantation: results of a multiinstitutional study. The Pediatric Heart Transplant Study Group.

BACKGROUND: Detailed information regarding the spectrum and predictors of infection after heart transplantation in children is limited because of relatively small numbers of patients at any single institution. We therefore used combined data obtained from the Pediatric Heart Transplant Study Group to gain additional information regarding infectious complications in the pediatric population. METHODS: To determine the time-related risk of infection and death related to infection in a large pediatric patient population, we analyzed data related to 332 pediatric patients (undergoing heart transplantation between January 1, 1993, and December 31, 1994) from 22 institutions in the Pediatric Heart Transplant Study Group. RESULTS: Among the 332 total patients, 276 infections were identified in 136 patients. Of those patients with development of infection, a single infection episode was reported in 54% of patients, 21% had two infections, and 25% had three or more infections. Of the 276 infections, 164 (60%) were bacterial, 51 (18%) were due to cytomegalovirus, 35 (13%) were other viral (noncytomegalovirus) infections, 19 (7%) were fungal, and 7 (2%) were protozoal. Bacterial infections were more common in infants younger than 6 months of age at time of transplantation, comprising 73% of all infections as compared with 49% in patients older than 6 months of age. The incidence of bacterial infection peaked during the first month after transplantation, with the actuarial likelihood of a bacterial infection among all patients reaching 25% at 2 months. The most common sites of bacterial infection were blood and lung (74% of bacterial infections). Cytomegalovirus accounted for 59% of viral infections, with a peak hazard occurring at 2 months after transplantation. Among all infections, cytomegalovirus was less common in infants younger than 6 months of age (8% of all infections) than in older patients (25%). By multivariate analysis, risk factors for early infection included younger recipient age (p = 0.05), mechanical ventilation at time of transplantation (p = 0.0002), positive donor cytomegalovirus serologic study result with negative recipient result (p = 0.004), and longer donor ischemic time (p = 0.04). The overall mortality rate from infection was 5%, with an actuarial freedom from death related to infection of 92% at 1 year after transplantation. The mortality rate was high in patients with fungal infections (52%), yet was low for those with cytomegalovirus infection (6%). Infections accounted for 27% of the overall mortality rate in infants younger than 6 months of age, compared with 16% for older patients. CONCLUSIONS: Although most infections in pediatric heart transplant recipients are successfully treated, infection remains an important cause of posttransplantation morbidity and death, especially in infants. Bacterial infections predominate within the first month after transplantation, whereas the peak hazard for viral infections occurs approximately 2 months after transplantation. Cytomegalovirus infections are common in the pediatric transplant population, but death related to cytomegalovirus is low.

ECMO for left ventricular assist in a newborn with critical aortic stenosis.

Extracorporeal membrane oxygenation (ECMO) has been used in neonates for a variety of disease states including congenital diaphragmatic hernia, meconium aspiration syndrome, sepsis, and postoperative cardiac compromise. To our knowledge, ECMO has not been employed prior to cardiac catheterization in critical aortic stenosis (CAS). We report a neonatal case of CAS where ECMO was used early as a form of left ventricular assist to achieve adequate systemic perfusion and oxygenation and reduce myocardial ischemia. The patient was maintained on ECMO during subsequent attempts at cardiac catheterization, balloon valvuloplasty, and operative valvotomy.

Relative bioavailability of L-ascorbyl-2-polyphosphate in broiler chickens.

Broiler chick diets and drinking water were supplemented with two sources of vitamin C: crystalline L-ascorbic acid (AsA) or L-ascorbyl-2-polyphosphate (APP) to provide 0, 25, 50, 100, 200, 400, 800, 1,600, and 3,200 ppm (mg/kg) AsA. The bioavailability of APP relative to AsA, as estimated by the change in plasma AsA concentration, was evaluated during 24-h periods of supplementation. When provided in the feed, no differences in dietary AsA content were attributed to vitamin source. In contrast, APP administration at 25 and 50 ppm, resulted in higher (P < .001) AsA values in drinking water when compared with AsA supplementation. Plasma AsA values were elevated (P < .05) above baseline when either AsA or APP were supplemented in the feed or water at a level of 400 ppm or greater. Plasma AsA concentrations, following supplementation of the diets, were higher (P < .05) in AsA-treated (800 ppm) chicks when compared with APP-supplemented chicks. During water supplementation, AsA (800 ppm) and APP (3,200 ppm) administration resulted in higher plasma AsA values when compared with their alternate vitamin source. At all other levels of water supplementation, no differences in plasma AsA were associated with vitamin source. The absence of a consistent difference in plasma AsA, relative to vitamin source, suggests that the isolated differences observed may be due to chance. It was concluded that APP was of similar bioavailability to that of AsA, as estimated by the ability to elevate plasma AsA concentrations in broiler chicks.

Leaching of amylose from wheat and corn starch.

Wheat starch gave a 21% yield (based on starch) of amylose (AM) when leached at 3% solids under mild agitation, and at a heating rate of 10 degrees C/min to 95 degrees C followed by holding at least 10 min. Annealing wheat starch prior to leaching at 95 degrees C or using a heating rate of 1 degrees C/min during leaching, increased AM yield from 21% to 23% at 3.0% starch solids, and 8% to 16% at 4.5% starch solids. At 0.5% solids, almost all wheat AM (29% of starch) was solubilized into the continuous phase at 95 degrees C, but only one-half of the lipid in the starch co-leached with AM. Corn starch behaved similarly to wheat starch during leaching below 1.5% starch solids, while at 3.0% almost 40% more AM was obtained from wheat than corn starch. Wheat AM molecules isolated by leaching were larger than those obtained by crystallizing its n-butanol complex, and they gave a different size-distribution as evidenced by high-performance size-exclusion chromatography. A triangular phase diagram was useful in depicting the overall process of leaching AM from starch. The critical concentrations of wheat (5.4%) and corn (5.2%) starches were determined using phase diagrams.

Liquid chromatographic determination of L-ascorbate 2-polyphosphate in fish feeds by enzymatic release of L-ascorbate.

An accurate method was devised to assay L-ascorbic 2-polyphosphate esters (AsPP) in fish feed by phosphatase digestion followed by determination of the released L-ascorbic acid (AsA). Compressed yeast and dithiothreitol are added to the phosphatase reaction mixture to give 95-100% recovery of AsA, which is quantitated by reverse-phase liquid chromatography (LC) with electrochemical detection. Chromatograms of all feed digests showed baseline resolution of AsA. In 3 feeds, to which 75-125 ppm AsA equivalents in the form of AsPP were added, the assay procedure gave 98-100% recovery of AsA.

Synthesis of methyl alpha- and beta-D-xylopyranoside-5-18O.

Methyl alpha- and beta-D-xylopyranoside-5-18O (5 and 6) were prepared by way of oxygen exchange between 18O-water and the periodate-oxidation product (1) obtained from 1,2-O-isopropylidene-alpha-D-glucofuranose. The isotopic enrichment of 5 and 6 was determined by hydrolysis of each to D-xylose-5-18O (3), conversion of the sugar into 1,2,3,4-tetrakis-O-(tert-butyldimethylsilyl)-beta-D-xylopyranose-5-18O (7), and determination of the 18O content of the latter by use of a quadrupole, mass spectrometer.