On the structure of bilirubin in solution. 13C[1H] heteronuclear Overhauser effect NMR analyses in aqueous buffer and organic solvents.

Select hydrogen-carbon distances have been determined from 13C[1H] heteronuclear Overhauser effects observed in a 99% carbon-13 enriched 13CO2H bilirubin analog, [8(3), 12(3)-13C2]-mesobilirubin XIII alpha. Analysis of the data confirms that the propionic acid carbonyl lies within hydrogen bonding distance to the dipyrrinone lactam and pyrrole N-H groups in chloroform and indicates, surprisingly, that those distances are only slightly longer in dimethyl sulfoxide solvent or when the carboxyl group is ionized in pH 7.4 aqueous buffered solutions of the pigment.

Hepatic uptake, transport and metabolism of alkylated bilirubins in Gunn rats and Sprague-Dawley rats.

We studied the metabolism and biliary excretion of four novel analogs of bilirubin in homozygous Gunn rats and Sprague-Dawley rats. All four compounds closely resemble bilirubin in constitutional structure but two of them contain strategically-placed geminal dimethyl substituents. These substituents destabilize, by steric buttressing, preferred ridge-tile conformational isomers and weaken intramolecular hydrogen bonding.

Use of non-radioactively labeled DNA probes for the detection of a baculovirus from Penaeus monodon by in situ hybridization on fixed tissue.

Clones isolated from a genomic library of the baculovirus PmSNPV (= MBV) were used to prepare DNA probes for detection of PmSNPV in shrimp tissue. Davidson's AFA fixed shrimp tissues were probed using DNA that had been labeled with the hapten, digoxigenin, by an in situ hybridization assay. The DNA probes readily distinguished PmSNPV-infected from uninfected shrimp tissue.

Comparison of the Microbial Quality of Raw Shrimp from China, Ecuador, or Mexico at Both Wholesale and Retail Levels.

Aerobic plate counts (APC), Listeria spp., and Vibrio spp. and antibiotic resistance patterns of Vibrio spp.

Antimicrobials in shrimp aquaculture in the United States: regulatory status and safety concerns.

The consumption of seafood, especially shrimp, increases yearly in the U.S. The U.

Partial cloning of the genome of infectious hypodermal and haematopoietic necrosis virus, an unusual parvovirus pathogenic for penaeid shrimps; diagnosis of the disease using a specific probe.

The infectious hypodermal and haematopoietic necrosis virus (IHHNV), pathogenic for penaeid shrimp, is an icosahedral unenveloped particle, 22 nm in diameter, with an ssDNA linear genome, and proposed to be a member of the Parvoviridae. A large majority of minus-strand DNA is incorporated into the capsids compared to the plus-strand. A small amount of reannealed plus- and minus-strands (dsDNA) obtained after nucleic acid extraction was blunt-ended and cloned into the system pUC18/Escherichia coli strain DH5 alpha.

Prostate biopsy indices: toward efficient use of transrectal ultrasound.

With increasing use of transrectal ultrasonography (TRUS) it becomes important to establish guidelines for its appropriate utilization. Three hundred and twenty-two patients with either an abnormal digital rectal examination (DRE) or prostate-specific antigen (PSA), or both, were evaluated further for cancer by means of prostatic ultrasonography. Two hundred and twenty-five (70%) of these underwent ultrasound-guided biopsy, cancer was detected in 74 (23%), and 33 percent of all biopsy specimens were positive.

Structure of 6-(3,3-dimethyl-2-oxo-2,3-dihydro-5-furanyl)-2-pyridone at 145 K.

C11H11NO3, M(r) = 205.21, triclinic, P1, a = 5.725 (1), b = 9.

Conformation inversion of bilirubin formed by reduction of the biliverdin-human serum albumin complex: evidence from circular dichroism.

As shown by circular dichroism spectroscopy, biliverdin preferentially adopts an M-helicity conformation on human serum albumin in aqueous buffer, pH 7.5, whereas biliverdin exhibits only a weak preference for the P-helicity conformation on bovine serum albumin at the same pH. Upon rapid reduction of the complexes with sodium borohydride, P-helicity bilirubin-IX alpha is obtained on the human albumin complex, and M-helicity bilirubin-IX alpha is obtained on the bovine serum albumin complex.

Performance of an aquatic multispecies system in evaluating the effects of a model microbial pest control agent on nontarget organisms.

A recirculating multispecies test system was developed in conjunction with a study of the fate and persistence of a model microbial pest control agent on non-target marine and freshwater organisms. The basic unit of the system was a 113-I glass aquarium with vertical biological filters in the center of the aquarium, such that two compartments were formed. This allowed the sequestration of predator and prey species within the same system.

Effect of volatile anesthetics on the circular dichroism of bilirubin bound to human serum albumin.

The characteristic circular dichroism of bilirubin bound to human serum albumin undergoes a remarkable sign inversion on addition of halothane, chloroform and other volatile anesthetics. This sign inversion, which is completely reversed by removal of the anesthetic, reflects a pronounced conformational change of the bound ligand; probably a complete inversion of chirality. The observation suggests that association of volatile anesthetics with proteins can markedly alter the internal topography of receptor sites and potentially influence the stereoselectivity of ligand binding.

Methods for viral isolation and DNA extraction for a penaeid shrimp baculovirus.

Procedures for the purification of virions and nucleocapsids of Baculovirus penaei (BP) of penaeid shrimp and subsequent extraction of the viral nucleic acid are described. BP-infected hepatopancrata, from two species of shrimp from different geographical locations in the Americas, were removed and homogenized in a solution of TN buffer (0.01 M Tris-HCl, 0.

Resonance Raman spectroscopy of bilirubins: band assignments and application to bilirubin/lipid complexation.

Resonance Raman spectra of bilirubins IX alpha, III alpha, and XIII alpha and mesobilirubin XIII alpha in alkaline aqueous and chloroform solutions are reported. Partial band assignments of bilirubin IX alpha are proposed. The model compounds confirm assignments of bands of the Raman spectrum of bilirubin IX alpha to each of the two different pyrromethenones.

Purification and characterization of the infectious hypodermal and haematopoietic necrosis virus of penaeid shrimps.

Infectious hypodermal and haematopoietic necrosis (IHHN) is one of the most important viral diseases of cultured penaeid shrimps and is potentially a limiting factor in the development of farming projects for some species of these shrimps. Although the IHHN agent was recognized early as being viral in origin, attempts to characterize it were inconclusive because of difficulties in obtaining sufficient amounts of purified virions to permit its characterization. Recent improvements of purification procedures have allowed the physicochemical characterization of this virus.

The effect of radiation therapy after radical prostatectomy in patients with elevated prostate specific antigen levels.

We analyzed the effects of pelvic radiation therapy given to patients who had an elevated prostate specific antigen level after radical prostatectomy. Among men who previously received adjuvant radiation therapy and had appropriately stored serum 15 had elevated prostate specific antigen levels after radical prostatectomy but before radiation therapy. After radiation therapy the prostate specific antigen level decreased by more than 50% in 80% and to female levels in 53% of the patients.

Prostate specific antigen and local recurrence after radical prostatectomy.

We evaluated the location of recurrent disease in 63 patients with carcinoma of the prostate who had abnormal levels of prostate specific antigen (greater than 0.4 ng./ml.

The value of serum prostate specific antigen determinations before and after radical prostatectomy.

We evaluated serum prostate specific antigen before and after radical prostatectomy. In 100 consecutive patients who underwent radical prostatectomy, preoperative prostate specific antigen levels tended to increase with the increasing severity of pathological stage. However, even at levels of greater than 10 ng.

Circular dichroism of bilirubin-amine association complexes: insights into bilirubin-albumin binding.

Bichromophoric (4Z, 15Z)-bilirubin-IX alpha, the yellow-orange cytotoxic pigment of jaundice, adopts either of two intramolecularly hydrogen-bonded enantiomeric conformations that are in dynamic equilibrium in solution. The addition of optically active amines induces the pigment solutions to exhibit intense bisignate circular dichroism in the region of the bilirubin long wavelength uv-visible absorption band. The most intense circular dichroism Cotton effects, (delta epsilon) approximately equal to 130, are induced by beta-arylamines and are comparable to those exhibited by bilirubin complexes with serum albumin and other proteins.

On the structure of albumin-bound bilirubin. Selective binding of intramolecularly hydrogen-bonded conformational enantiomers.

The intramolecularly hydrogen-bonded bichromophoric tetrapyrrole pigments, bilirubin-IX alpha and mesobilirubin-XIII alpha, adopt either of two folded, intramolecularly hydrogen-bonded, enantiomeric conformations which are in dynamic equilibrium in solution. Added human serum albumin binds preferentially, although not necessarily exclusively, to one conformational enantiomer, and the solutions exhibit bisignate circular dichroism Cotton effects in the region of the pigment's long wavelength electronic transition. In contrast, the bichromophoric tetrapyrrole pigment mesobilirubin-IV alpha, which is incapable of adopting intramolecularly hydrogen-bonded folded conformations, and the monochromophoric pyrromethenone, xanthobilirubic acid, show only monosignate induced circular dichroism Cotton effects under the same conditions.

'Like a shrivelled blood orange'--bilirubin, jaundice, and phototherapy.

The biochemistry of bilirubin is reviewed with particular reference to newborn infants. The formation, properties, and metabolism of bilirubin are summarized and the importance of molecular shape, hydrogen-bonding, and polarity on the biologic disposition of bilirubin is emphasized. The chemical basis for the subtle influence of visible (blue) light on bilirubin structure and metabolism is explained, and recent concepts of the mechanism of phototherapy are presented.