Payer Type and Emergency Department Visit Prices

This cross-sectional study assesses list prices, cash prices, and negotiated rates for emergency department services.

Association of limited English proficiency with emergency department irregular departures and return visits: A cross-sectional cohort study in the Upper Midwest between January 2018 and December 2021

OBJECTIVES

Patients with limited English proficiency (LEP) have been shown to experience disparities in emergency department (ED) care. The objectives of this study were to examine the associations between LEP and irregular ED departures and return ED visits.

METHODS

We conducted a multicenter cross-sectional analysis of 18 EDs within an integrated health system in the upper Midwest from January 1, 2018, to December 31, 2021. ED visits of pediatric and adult patients who were discharged on the index visit were included for analysis. We analyzed the association of LEP with irregular departures, 72-h and 7-day return visits, and ED disposition at the time of that return visit. Multivariable model associations were calculated using generalized estimating equations and reported as odds ratios (OR) with 95% confidence intervals (CIs).

RESULTS

A total of 745,464 total ED visits were analyzed, including 27,906 (3.7%) visits among patients with LEP. The most common preferred languages among patients with LEP were Spanish (12,759; 45.7%), Somali (4978; 17.8%), and Arabic (3185; 11.4%). After multivariable adjustment there were no differences in proportions of irregular departures (OR 1.09, 95% CI 0.99-1.21), 72-h returns (OR 0.99, 95% CI 0.92-1.06), or 7-day returns (OR 0.99, 95% CI 0.93-1.05) between patients with LEP or English proficiency. Patients with LEP returning within 72 h (OR 1.19, 95% CI 1.01-1.40) and 7 days (OR 1.15, 95% CI 1.01-1.33) were more likely to be admitted to the hospital.

CONCLUSIONS

After multivariable adjustment, we did not find an increased frequency of irregular ED departures or 72-h or 7-day returns among patients with LEP compared with people proficient in English. However, we did find that higher proportions of patients with LEP were admitted to the hospital at the time of the return ED visit.

More Than Just a Weed: An Exploration of the Antimicrobial Activity of Rumex crispus using a Multivariate Data Analysis Approach

Plants have a long history of use for their medicinal properties. The complexity of botanical extracts presents unique challenges and necessitates the application of innovative approaches to correctly identify and quantify bioactive compounds. For this study, we used untargeted metabolomics to explore the antimicrobial activity of Rumex crispus (yellow dock), a member of the Polygonaceae family used as an herbal remedy for bacterial infections. Ultra-performance liquid chromatography coupled with high resolution mass-spectrometry (UPLC-MS) was used to identify and quantify the known antimicrobial compound emodin. In addition, we used biochemometric approaches to integrate data measuring antimicrobial activity from R. crispus root starting material and fractions against methicillin-resistant Staphylococcus aureus (MRSA) with UPLC-MS data. Our results support the hypothesis that multiple constituents, including the anthraquinone emodin, contribute to the antimicrobial activity of R. crispus against MRSA.

Capturing the antimicrobial profile of Rosmarinus officinalis against methicillin-resistant Staphylococcus aureus (MRSA) with bioassay-guided fractionation and bioinformatics

Natural products have been a primary source of medicines throughout the history of human existence. It is estimated that close to 70 % of small molecule pharmaceuticals on the market are derived from natural products. With increasing antibiotic resistance, natural products remain an important source for the discovery of novel antimicrobial compounds. The plant rosemary (Rosmarinus officinalis), has been widely and commonly used as a food preservative due to its antimicrobial potential. To evaluate the antimicrobial profile of this plant, we used bioassay-guided fractionation and bioinformatics approaches. Through bioassay-guided fractionation, we tested in vitro activities of a R. officinalis extract and fractions thereof, as well as pure compounds micromeric acid (1), oleanolic acid (2), and ursolic acid (3) against methicillin-resistant Staphylococcus aureus (MRSA). Compounds 1 and 3 showed complete inhibition of MRSA (with MIC values of 32 μg/mL and 8 μg/mL, respectively) while compound 2 displayed only partial inhibition (MIC > 64 μg/mL). In addition, we utilized orthogonal partial least square-discriminant analysis (OPLS-DA) and selectivity ratio (SR) analysis to correlate the isolated compounds 1-3 with the observed antimicrobial activity, as well as to identify antimicrobials present in trace quantities. For mass spectrometry (MS) data collected in the negative ionization mode, compound 1 was the most positively correlated with activity, while for MS data collected in the positive ion mode, compounds 2-3 had the highest positive correlation. Using the bioinformatics approaches, we highlighted additional antimicrobials associated with the antimicrobial activity of R. officinalis, including genkwanin (4), rosmadial (5a) and/or 16-hydroxyrosmadial (5b), rosmanol (6), and hesperetin (7). Compounds 1-3 resulting from the bioassay-guided fractionation were identified by MS-MS fragmentation patterns and 1H NMR spectra. Among the compounds highlighted by the biochemical analysis, compound 6 was identified by comparison with its commercial standard by employed ultra-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS), while 4, 5a-b and 7 were putatively identified based on MS data and in comparison with the literature. This is the first reported antimicrobial activity of micromeric acid (1) against MRSA.

Ruptured Ectopic Pregnancy with an Intrauterine Device: Case Report and Sonographic Considerations

INTRODUCTION

Ectopic pregnancy carries a high morbidity and mortality; patients are at risk for rupture and life-threatening hemorrhage.

CASE REPORT

We present a rare case of ruptured abdominal ectopic pregnancy in a patient with a well-positioned intrauterine device (IUD) and discuss the diagnostic utility that transabdominal point-of-care ultrasound (POCUS) can have when performed at the bedside.

CONCLUSION

While pregnancy with an IUD in place is rare, when it is encountered the emergency provider should maintain a high degree of suspicion for extrauterine pregnancy and perform prompt evaluation for hemorrhagic shock using diagnostic POCUS.

Targeted and untargeted analysis of secondary metabolites to monitor growth and quorum sensing inhibition for methicillin-resistant Staphylococcus aureus (MRSA)

Drug resistant infections are an increasing problem world-wide, responsible for an estimated 700,000 annual mortalities. The use of antibiotics to treat such infections has resulted in the development of resistant bacterial pathogens such as methicillin-resistant Staphylococcus aureus (MRSA). One potential alternative strategy for treating drug resistant bacterial infections is to inhibit the production of toxins, thereby making the bacteria less harmful to the host, a so called "anti-virulence" approach. In MRSA, the agr quorum sensing system is one of the major regulators of toxin production, and quorum sensing inhibitors that target this system are a promising anti-virulence strategy. With this study, we developed a method that enables the activity of quorum sensing inhibitors to be measured using ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-MS). This method is an improvement over existing methods because it can be employed to distinguish antimicrobial activity from quorum sensing inhibition activity based on the UPLC-MS data. This is possible by simultaneously tracking production of metabolites regulated by the agr quorum sensing system (AIP-I and formylated δ-toxin) and a metabolite that appears not to be agr regulated under the conditions of this study (aureusimine B). The newly developed method provides more nuanced indication of how metabolite production changes over time and in response to quorum sensing or growth inhibition than is possible with commonly employed spectroscopic methods.

Recognition of the lipoyl domain is the ultimate determinant of substrate channelling in the pyruvate dehydrogenase multienzyme complex

Reductive acetylation of the lipoyl domain (E2plip) of the dihydrolipoyl acetyltransferase component of the pyruvate dehydrogenase multienzyme complex of Escherichia coli is catalysed specifically by its partner pyruvate decarboxylase (E1p), and no productive interaction occurs with the analogous 2-oxoglutarate decarboxylase (E1o) of the 2-oxoglutarate dehydrogenase complex. Residues in the lipoyl-lysine beta-turn region of the unlipoylated E2plip domain (E2plip(apo)) undergo significant changes in both chemical shift and transverse relaxation time (T(2)) in the presence of E1p but not E1o. Residue Gly11, in a prominent surface loop between beta-strands 1 and 2 in the E2plip domain, was also observed to undergo a significant change in chemical shift. Addition of pyruvate to the mixture of E2plip(apo) and E1p caused larger changes in chemical shift and the appearance of multiple cross-peaks for certain residues, suggesting that the domain was experiencing more than one type of interaction. Residues in both beta-strands 4 and 5, together with those in the prominent surface loop and the following beta-strand 2, appeared to be interacting with E1p, as did a small patch of residues centred around Glu31. The values of T(2) across the polypeptide chain backbone were also lower than in the presence of E1p alone, suggesting that E2plip(apo) binds more tightly after the addition of pyruvate. The lipoylated domain (E2plip(holo)) also exhibited significant changes in chemical shift and decreases in the overall T(2) relaxation times in the presence of E1p, the residues principally affected being restricted to the half of the domain that contains the lipoyl-lysine (Lys41) residue. In addition, small chemical shift changes and a general drop in T(2) times in the presence of E1o were observed, indicating that E2plip(holo) can interact, weakly but non-productively, with E1o. It is evident that recognition of the protein domain is the ultimate determinant of whether reductive acetylation of the lipoyl group occurs, and that this is ensured by a mosaic of interactions with the Elp.

Volumetric and dimensional analysis of the guinea pig inner ear

The objective of this study was to provide accurate volumetric data on the fluid spaces and soft tissue in the guinea pig inner ear by measuring all histologic serial sections by means of Metamorph Imaging Software at 400x to 1,000x magnification. The total endolymph volume of the inner ear was 4.691 mm3, of which 1.501 mm3 was in the cochlea, 3.090 mm3 in the vestibular labyrinth, and 0.100 mm3 in the endolymphatic duct and sac. The total perilymph volume was 15.938 mm3, of which 8.867 mm3 was in the cochlea and 7.071 mm3 in the vestibular labyrinth. The volume of the organ of Corti per millimeter length increased toward the apex, but the volumes of the stria vascularis, spiral ligament, and spiral limbus decreased. The volume of the macula utriculi was larger than that of the macula sacculi. The measurement of the luminal surface area of the stria vascularis was 3.944 mm2, and that of the vestibular dark cells was 5.772 mm2.

Restricted motion of the lipoyl-lysine swinging arm in the pyruvate dehydrogenase complex of Escherichia coli

The three lipoyl (E2plip) domains of the dihydrolipoyl acetyltransferase component of the pyruvate dehydrogenase (PDH) complex of Escherichia coli house the lipoyl-lysine side chain essential for active-site coupling and substrate channelling within the complex. The structure of the unlipoylated form of the innermost domain (E2plip(apo)) was determined by multidimensional NMR spectroscopy and found to resemble closely that of a nonfunctional hybrid domain determined previously [Green et al. (1995) J. Mol. Biol. 248, 328-343]. The domain comprises two four-stranded beta-sheets, with the target lysine residue residing at the tip of a type-I beta-turn in one of the sheets; the N- and C-termini lie close together at the opposite end of the molecule in the other beta-sheet. Measurement of (15)N NMR relaxation parameters and backbone hydrogen/deuterium (H/D) exchange rates reveals that the residues in and surrounding the lipoyl-lysine beta-turn in the E2plip(apo) form of the domain become less flexible after lipoylation of the lysine residue. This implies that the lipoyl-lysine side chain may not sample the full range of conformational space once thought. Moreover, reductive acetylation of the lipoylated domain (E2plip(holo) --> E2plip(redac)) was accompanied by large changes in chemical shift between the two forms, and multiple resonances were observed for several residues. This implies a change in conformation and the existence of multiple conformations of the domain on reductive acetylation, which may be important in stabilizing this catalytic intermediate.

Structural determinants of post-translational modification and catalytic specificity for the lipoyl domains of the pyruvate dehydrogenase multienzyme complex of Escherichia coli

The lipoyl domains of the dihydrolipoyl acyltransferase (E2p, E2o) components of the pyruvate and 2-oxoglutarate dehydrogenase multienzyme complexes are specifically recognised by their cognate 2-oxo acid decarboxylase (E1p, E1o). A prominent surface loop links the first and second beta-strands in all lipoyl domains, close in space to the lipoyl-lysine beta-turn. This loop was subjected to various modifications by directed mutagenesis of a sub-gene encoding a lipoyl domain of Escherichia coli E2p. Deletion of the loop (four residues) rendered the domain incapable of reductive acetylation by E. coli E1p in the presence of pyruvate, but insertion of a new loop (six residues) corresponding to that in the E2o lipoyl domain partly restored this ability, albeit with a much lower rate. However, the modified domain remained unable to undergo reductive succinylation by E1o in the presence of 2-oxoglutarate. Additional exchange of the two residues on the C-terminal side of the loop (V14A, E15T) had no effect. Insertion of a different four-residue loop also restored a limited ability to undergo reductive acetylation, but still significantly less than that of the wild-type domain. Exchanging the residue on the N-terminal side of the lipoyl-lysine beta-turn in the E2p and E2o domains (G39T), both singly and in conjunction with the loop exchange, had no effect on the ability of the E2p domain to be reductively acetylated but did confer a slight increase in susceptibility to reductive succinylation. All mutant E2p domains, apart from that with the loop deletion (LD), were readily lipoylated in vitro by E. coli lipoate protein ligase A; the E2p LD mutant could be lipoylated only at a significantly lower rate. Likewise, this domain exhibited 1D and 2D NMR spectra characteristic of a partially folded protein, whereas the spectra of mutants with modified loops were similar to those of the wild-type domain. The surface loop is evidently important to the structural integrity of the domain and may help to stabilize the thioester bond linking the acyl group to the reduced lipoyl-lysine swinging arm as part of the catalytic mechanism. Recognition of the lipoyl domain by its partner E1 appears to be a complex process and not attributable to any single determinant on the domain.

Detection of total and hemolysin-producing Vibrio parahaemolyticus in shellfish using multiplex PCR amplification of tl, tdh and trh

Vibrio parahaemolyticus is an important human pathogen which can cause gastroenteritis when consumed in raw or partially-cooked seafood. A multiplex PCR amplification-based detection of total and virulent strains of V. parahaemolyticus was developed by targeting thermolabile hemolysin encoded by tl, thermostable direct hemolysin encoded by tdh, and thermostable direct hemolysin-related trh genes. Following optimization using oligonucleotide primers targeting tl, tdh and trh genes, the multiplex PCR was applied to V. parahaemolyticus from 27 clinical, 43 seafood, 15 environmental, 7 strains obtained from various laboratories and 19 from oyster plants. All 111 V. parahaemolyticus isolates showed PCR amplification of the tl gene; however, only 60 isolates showed amplification of tdh, and 43 isolates showed amplification of the trh gene. Also, 18 strains showed amplification of the tdh gene, but these strains did not show amplification of the trh gene. However, one strain exhibited amplification for the trh but not the tdh gene, suggesting both genes need to be targeted in a PCR amplification reaction to detect all hemolysin-producing strains of this pathogen. The multiplex PCR approach was successfully used to detect various strains of V parahaemolyticus in seeded oyster tissue homogenate. Sensitivity of detection for all three target gene segments was at least between 10(1)-10(2) cfu per 10 g of alkaline peptone water enriched seeded oyster tissue homogenate. This high level of sensitivity of detection of this pathogen within 8 h of pre-enrichment is well within the action level (10(4) cfu per 1 g of shell stock) suggested by the National Seafood Sanitation Program guideline. Compared to conventional microbiological culture methods, this multiplex PCR approach is rapid and reliable for accomplishing a comprehensive detection of V. parahaemolyticus in shellfish.

Cysteine sulfinic acid decarboxylase mRNA abundance decreases in rats fed a high-protein diet

The partitioning of cysteine metabolism between sulfate and taurine biosynthetic pathways may be regulated in part by the activity of cysteine sulfinic acid decarboxylase (CSAD). CSAD activity is repressed by high-protein feeding, and we have previously reported that changes in CSAD activity are correlated with changes in CSAD protein. We conducted experiments to determine the relative expression of CSAD mRNA in rats fed 18 or 60% casein diets. In rats fed a 60% casein diet for 1 wk, hepatic CSAD activity and CSAD protein were 16 and 36%, respectively, of the values measured in rats fed the 18% casein diet. CSAD mRNA abundance in rats fed the 60% casein diet was 14% of the CSAD mRNA abundance in rats fed an 18% casein diet. The time course of the change in CSAD activity and mRNA abundance was examined in rats fed 18 or 60% casein diets for 48 h. Within 6 h of switching rats to a 60% casein diet, CSAD activity was decreased by 20% and after 48 h, activity was decreased 47% compared to activity measured at baseline. CSAD mRNA abundance was decreased 54% within 12 h of feeding rats a high-protein diet and remained depressed at 48 h. In a parallel group of rats fed the 18% casein diet, CSAD activity and CSAD mRNA were not significantly different from baseline values at 48 h. The decreased expression of CSAD mRNA in rats fed a high-protein diet is consistent with decreases in both CSAD enzyme activity and CSAD protein. Our results suggest dietary protein may regulate CSAD at the level of mRNA.

Detection of microbial pathogens in shellfish with multiplex PCR

Multiplex PCR amplification of uidA, cth, invA, ctx, and tl genes was developed enabling simultaneous detection in shellfish of Escherichia coli, an indicator of fecal contamination and microbial pathogens, Salmonella typhimurium, Vibrio vulnificus, V. cholerae, and V. parahaemolyticus, respectively. Each of the five pairs of oligonucleotide primers was found to support PCR amplifications of only its targeted gene. The optimized multiplex PCR reaction utilized a PCR reaction buffer containing 2.5 mM MgCl2 and primer annealing temperature of 55 degrees C. Oyster tissue homogenate seeded with these microbial pathogens was subjected to DNA purification by the Chelextrade mark 100 (BioRad) method. The sensitivity of detection for each of the microbial pathogens was </=10(1)-10(2) cells following a "double" multiplex PCR amplification approach. Amplified target genes in a multiplex PCR reaction were subjected to a colorimetric GeneCombtrade mark (BioRad) DNA-DNA hybridization assay. This assay was rapid and showed sensitivity of detection comparable to the agarose gel electrophoresis method. The colorimetric GeneCombtrade mark assay avoids use of hazardous materials inherent in conventional gel electrophoresis and radioactive-based hybridization methods. Multiplex PCR amplification, followed by colorimetric GeneCombtrade mark DNA-DNA hybridization, has been shown to be an effective, sensitive, and rapid method to detect microbial pathogens in shellfish.

Detection of Giardia in environmental waters by immuno-PCR amplification methods

Genomic DNA was extracted either directly from Giardia muris cysts seeded into environmental surface waters or from cysts isolated by immunomagnetic beads (IMB). A 0.171-kbp segment of the giardin gene was PCR-amplified following "direct extraction" of Giardia DNA from seeded Cahaba river water concentrate with moderate turbidity (780 JTU's), but DNA purified from seeded Colorado river water concentrates with high turbidity (2 x 10(5) JTUs) failed to amplify. However, if the cysts were first separated by the IMB approach from seeded Cahaba or Colorado river waters, and the DNA released by a freeze-boil Chelex(R)100 treatment, detection of G. muris by PCR amplification could be achieved at a sensitivity of 3 x 10(0) or 3 x 10(1) cysts/ml, respectively. If, however, the G. muris cysts used to seed even moderately turbid river waters (780 JTUs) were formalin treated (which is conventionally used for microscopic examination), neither direct extraction nor IMB purification methods yielded amplifiable DNA. Use of immunomagnetic beads to separate Giardia cysts from complex matrices of environmental surface waters followed by DNA release and PCR amplification of the target giardin gene improved the reliability of detection of this pathogen with the required sensitivity.

Calcium and vitamin D status of pregnant teenagers in Maiduguri, Nigeria

This study investigates parameters related to calcium and bone metabolism by determining the concentrations of total calcium, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, parathyroid hormone, and phosphorous in young pregnant women. The patient population was 30 pregnant Nigerian teenage women grouped by trimester (10 per group), 10 women immediately following delivery, and 21 healthy age-matched controls. On the basis of serum prealbumin levels, the general nutrition of the pregnant women was found to be significantly below that of the more privileged and better-educated nonpregnant controls. The mean total calcium concentration in sera of the third-trimester women was 8.83 mg/dL, which was significantly below that of the controls (9.77 mg/dL) and the first-trimester group (9.30 mg/dL). Despite the 10% to 15% decline in the serum level of total calcium during pregnancy, the parathyroid hormone level decreased markedly from 0.60 to 0.61 ng/mL in the first and second trimesters to 0.41 ng/mL in the third trimester. Serum vitamin D and 1,25-dihydroxyvitamin D levels in the second and third trimesters were within the normal range. These data indicate that toward the end of gestation, pregnant teenagers in northern Nigeria appear to become calcium deficient and do not exhibit the expected increase in serum parathyroid hormone levels normally seen in pregnant women.

Biodegradability and microbial activities during composting of poultry litter

Poultry litter is composted to reduce odor and pathogens and to improve its quality as a soil amendment. Organic material, e.g., sawdust, is added to increase the C:N ratio to achieve optimum degradation of organic C and retention of N through microbial biomass formation. However, the relative biodegradabilities of the organic material in poultry litter and the amendment are usually not known. Furthermore, it is assumed that as microorganisms metabolize organic compounds and produce CO2, they increase in biomass and, therefore, retain N. In this study, bench-scale compost reactors were used to determine the relative contributions of poultry litter and of the amendment (sawdust) to the biodegradability of a compost mix. Approximately 29% of the volatiles lost from the poultry litter mix came from the sawdust. Fiber analyses revealed that only a small portion of cellulose was degraded. Although microbial subpopulations able to degrade selected macromolecules were present at varying levels, the overall level of microorganisms did not change markedly. Populations capable of degrading bacterial cell walls were present throughout the composting period, and microbiological assays indicated that inorganic nutrients were available to support limited microbial growth. These results suggest that N compounds and inorganic nutrients are recycled, rather than fixed during composting.

Detection of viable Vibrio cholerae by reverse-transcriptase polymerase chain reaction (RT-PCR)

The use of conventional PCR can amplify target DNA from both viable and nonviable cells of Vibrio cholera. Detection of only viable microbial pathogens in biological samples, especially clinical and food samples, is usually desired to ensure positive test results are associated with active agents, and not the remains of dead cells. Positive identifications caused by nonliving causative agents may lead to misguided decisions concerning the effectiveness of treatment, and whether patient treatment should be continued or whether the food should be discarded. Consequently, this work was directed toward development of a reverse-transcriptase polymerase chain reaction (RT-PCR)-based in vitro DNA amplification method, which specifically detects only viable cells. Total RNA from both viable and nonviable cells was purified by using a FastPrep Cell Disrupter ([symbol: see text]Bio 101/Savant) and FastRNA extraction reagents ([symbol: see text]Bio 101). The purified RNA was treated with DNase I (RNase-free) to avoid any amplification from the contaminating target DNA. An RT-PCR approach using this rapid and effective method for RNA purification showed amplification of the target mRNA only from the viable cells. The sensitivity of detection of viable cells of V. cholerae was > or = 10(3), which is well within the minimum number of cells (10(5)-10(6)) required for infection. The use of a reliable prokaryotic RNA extraction method followed by RT-PCR amplification of the target mRNA can be used for specific detection of viable microbial pathogen, such as V. cholerae.

Prospects for the genetic manipulation of dairy cattle: opportunities beyond BST

The dairy industry, with regulatory approvals of recombinant chymosin and bovine somatotropin (BST), has been at the forefront of food and agricultural biotechnology. The commercial fate of these products is one of several factors that may affect the success of future genetic manipulations in dairy cattle and dairy products. Other factors include technical and reproductive constraints in cattle and the cost of producing transgenic cattle. Early applications of genetic manipulation in cattle, for reasons of cost recoupment, may favor production of heterologous proteins in milk for pharmaceutical and medical use. Such applications could benefit genetic modification of milk and milk proteins for food use by providing advance knowledge and experience in mammalian protein expression. Other research opportunity areas that could affect prospects for genetic manipulation of dairy cattle include genome mapping, metabolic pathways, growth and development, and cattle/microbe interactions.

Caloundrin B and Funiculatin A: New Polypropionates From Siphonariid Limpets

Two new polypropionates, caloundrin B (11), systematic name (1″R,2R,3″R,4R,5S,5″R,6S,-7″R,8″S,9″S,10″R)-2-(6′-ethyl-3′,5′-dimethyl-4′-oxopyran-2′-yl)-6-(5″-ethyl-7″-hydroxy-8″,9″,10″-trimethyl-2″,4″,6″-trioxatricyclo[3.3.1.13,7]dec-3″-yl)-5-hydroxy-4-methylheptan-3-one, and funiculatin A (12), systematic name (2ξ,1′S,4R,5′S,6′S)-2-(1′-ethyl-4′,6′,8′-trimethyl-2𔈀,9′-dioxabicyclo[3.3.1]nona-3′,7′-dien-3′-yl)-4,6-dimethylnon-6-en-3-one, have been isolated from Siphonaria zelandica and S. funiculata respectively. The structures of the new compounds were deduced by two-dimensional n.m.r. spectroscopy, particularly long-range 13C- 1H correlation spectroscopy (HMBC), by biosynthetic reasoning and by comparison with the known polypropionates denticulatin A (5), siphonarin B (8), muamvatin (9) and baconipyrone C (14). Information about the relative stereochemistry of the tricyclic ring system of (11) and the bicyclic ring system of (12) was deduced from coupling constant values, and by n.O.e. difference and NOESY experiments, and was confirmed by molecular modelling studies. The relative stereochemistry of the side chains and the absolute stereochemistry were inferred from biosynthetic comparison with the above known polypropionates, and by correlation of funiculatin A with denticulatin A (5) of known absolute stereochemistry. The stereochemistry at C10 of funiculatin A (position 2 of the non-6-en-3-one chain) could not be unambiguously determined. A third new polypropionate funiculatin B, epimeric with funiculatin A at C10, was isolated and partially characterized.

Expression of a foreign gene in Chlamydomonas reinhardtii

Genomic transformation of Chlamydomonas reinhardtii exposed to glass-bead abrasion was accomplished with a chimeric neomycin phosphotransferaseII (NPTII)-encoding gene (nos::npt) flanked by the nopaline synthase promoter and polyadenylation sequences obtained from the Ti plasmid of Agrobacterium tumefaciens. These sequences were in a plasmid (pGA482) which also contained gene nit1 encoding nitrate reductase of C. reinhardtii. Transformants were selected by their ability to grow on medium containing nitrate, and 52% of these was also resistant to kanamycin. Evidence for nos::npt expression includes: (1) hybridization with probes specific for npt, (2) demonstration of NPTII activity after electrophoresis of extracts, and (3) chromatographic identification of the reaction product of NPTII, kanamycin phosphate. The highly biased codon usage in Chlamydomonas does not preclude expression.

Norepinephrine inhibits rat pre-adipocyte proliferation

Hormonal and neural status are major determinants for cellular growth. The purpose of this study was to assess the influence of the adrenergic hormones on pre-adipocyte growth in primary cell culture. Stromal-vascular cells were obtained from the inguinal pad of young rats and grown in culture for two weeks. Cells were exposed to norepinephrine (NE) during the proliferative phase of growth, labelled by [3H]-thymidine incorporation and then placed on a differentiation promoting medium. Adipocytes and stromal cells were separated using a density gradient, and [3H]-thymidine content was determined for both cell types. NE reduced [3H]-thymidine uptake indicating a reduction in pre-adipocyte proliferation. NE-induced inhibition of pre-adipocyte growth was blocked by the presence of propranolol, whereas phenoxybenzamine had no effect, thereby suggesting that NE-inhibition is through beta-adrenoceptors. Pre-adipocytes were treated with NE for varying lengths of time to investigate whether cells were desensitized to chronic beta-adrenergic stimulation. In addition, adenosine deaminase (ADA) was also applied to eliminate adenosine which may accumulate during NE stimulation. Neither the duration of NE exposure nor ADA treatment affected adrenergic control of adipocyte growth. These studies indicate that NE reduces pre-adipocyte proliferation and therefore may be an important negative regulatory component of adipocyte growth.

Local regeneration in the retina of the goldfish

We have studied regeneration of the retina in the goldfish as a model of regenerative neurogenesis in the central nervous system. Using a transscleral surgical approach, we excised small patches of retina that were replaced over several weeks by regeneration. Lesioned retinas from three groups of animals were studied to characterize, respectively, the qualitative changes of the retina and surrounding tissues during regeneration, the concomitant cellular proliferation, and the quantitative relationship between regenerated and intact retina. The qualitative and quantitative analyses were done on retinas prepared using standard methods for light microscopy. The planimetric density of regenerated and intact retinal neurons was computed in a group of animals in which the normal planimetric density ranged from high to low. Cell proliferation was investigated by making intraocular injections of 5-bromo-2'-deoxyuridine (BUdr) at various survival times to label proliferating cells and processing retinal sections for BUdr immunocytochemistry. The qualitative analysis showed that the surgery created a gap in the existing retina that was replaced with new retina over the subsequent weeks. The BUdr-labeling experiments demonstrated that the excised retina was replaced by regeneration of new neurons. Neuroepithial-like cells clustered on the wound margin and migrated centripetally, appositionally adding new retina to the old. The quantitative analysis showed that the planimetric density of the regenerated neurons approximated that of the intact ones.

Evaluation of a simple method for the measurement of cytidine deaminase in serum and comparison with a reference method

This study was designed to evaluate a cytidine deaminase (CD) assay modified to allow results to be achieved within one working day. Inter-batch variation for samples of mean (SD) CD activity, 10.2 (1.0) units, 17.5 (1.2) units and 31.7 (1.7) units were, 9.8%, 6.9% and 5.4% respectively (n = 26). The reference range (3.2-13.2 U) was similar in males and females and was independent of age. There was close correlation with a reference method (r = 0.96). The mean difference between methods was 2.7 U and the limits of agreement were -1.7 to 7.1 U. The results indicate that the short assay technique can produce results that are sufficiently accurate and precise to be clinically useful.

An update of the enzymology and regulation of sphingomyelin metabolism

Sphingomyelin is found in plasma membranes and related organelles (such as endocytic vesicles and lysosomes) of all tissues, as well as in lipoproteins. Abnormalities in sphingomyelin metabolism have been associated with atherosclerosis, cancer and genetically transmitted diseases; however, except for Niemann-Pick disease, little is known about the mechanism for these disorders. Sphingomyelin biosynthesis de novo involves ceramide formation from serine and two mol of fatty acyl-CoA followed by addition of the phosphocholine headgroup. The headgroup appears to come from phosphatidylcholine, but other sources have not been ruled out. Factors that influence the rate of sphingomyelin synthesis include the availability of serine and palmitic acid, plus the relative activities of key enzymes of this pathway. Sphingomyelin turnover involves removal of the headgroup and amide-linked fatty acid by sphingomyelinases and ceramidases, respectively, which have been found in both lysosomes (with acidic pH optima) and plasma membranes (with neutral to alkaline pH optima). The enzymes of sphingomyelin turnover release ceramide and free sphingosine from endogenous substrates, which may have implications for the participation of a sphingomyelin/sphingosine cycle as another 'lipid second messenger' system.

Sera from pigs infected with Sarcocystis suicanis and cachectin decrease preadipocyte differentiation in primary cell culture

The macrophage-secreted hormone cachectin depressed lipoprotein lipase activity and lipogenic enzymes in adipose cells. Cachectin reduced differentiation of preadipocytes in cultures of stromal-vascular cells from rat adipose tissue. Differentiation was measured by two methods of estimating lipid accumulation. Adipocytes were separated from the stromal-vascular cells by centrifugation and staining (oil red 0) for intracellular lipid. Lipolytic activity was measured by using esterase histochemistry. Sera from pigs that were infected with Sarcocystis suicanis showed cachectin-like activity compared with sera collected from the same animals before infection. Cachectin and sera collected from infected animals specifically decreased fat cell number without decreasing the stromal-vascular cell number.

Serum cytidine deaminase levels after withdrawal of non-steroidal anti-inflammatory treatment in rheumatoid arthritis

Increases in joint inflammation in nine patients with rheumatoid arthritis were provoked by withdrawal of their non-steroidal anti-inflammatory drugs. Pain score, duration of morning stiffness, Ritchie articular index score, and the number of analgesic tablets consumed reached peaks after five, three, five, and five days respectively compared with values during six days of normal treatment. Changes in serum cytidine deaminase (believed to reflect polymorph turnover in inflamed joints) showed a different pattern, with a sharp peak after two days and a subsequent trough. Possible mechanisms for these differences are discussed.

Influence of manure gases on puberty in gilts

To determine whether manure gases can influence onset of puberty in gilts, 42 crossbred gilts were reared from 10 to 40 wk of age on concrete slats over a 1.22-m deep pit that was drained and refilled with clean water biweekly (clean group). Forty-one gilts were reared over a similar type pit where manure was allowed to accumulate (control group). Treatments were in two separate rooms of the same building with similar feeding, water, floor space, lighting and room temperature. Ventilation fans with timer controls in each room were set so fans in the clean environment ran twice as long as fans in the control environment. Aerial concentrations of ammonia in the control room were fourfold higher than in the clean room (21 vs 5 ppm), while aerial concentrations of hydrogen sulfide were similar. Average daily gain and feed efficiency were similar for both groups [.69 vs .72 kg/d (P = .31) and 1.61 vs 1.54 kg feed/kg gain (P = .52)]. From 20 to 40 wk of age, all gilts were exposed to a mature boar three times weekly, utilizing four boars in rotation. Blood samples were collected weekly from each gilt by venipuncture and analyzed for progesterone to establish time of first ovulation. A greater proportion of gilts in the clean group attained puberty by 24 to 26 wk (P less than .05) and 27 to 29 wk of age (P less than .10) compared with the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Novel Actinomycete Isolated from Bulking Industrial Sludge

A novel actinomycete was the predominant filamentous microorganism in bulking activated sludge in a bench-scale reactor treating coke plant wastewater. The bacterium was isolated and identified as an actinomycete that is biochemically and morphologically similar to Amycolatopsis orientalis ; however, a lack of DNA homology excludes true relatedness. At present, the isolate (NRRL B 16216) cannot be assigned to the recognized taxa of actinomycetes.

Physical properties of five grain dust types

Physical properties of grain dust derived from five grain types (soybean, rice, corn, wheat, and sorghum) were measured and reported. The grain dusts were obtained from dust collection systems of terminal grain handling facilities and were assumed to be representative of grain dust generated during the handling process. The physical properties reported were as follows: particle size distributions and surface area measurements using a Coulter Counter Model TAII; percent dust fractions less than 100 micron of whole dust; bulk density; particle density; and ash content.

Legal and regulatory aspects of genetically engineered animals

The commercialization of genetically engineered food animals will pose a number of legal and regulatory questions. These may be grouped into questions of process and questions of products. The process of animal genetic engineering with artificially constructed vectors will probably be regulated in much the same manner as other veterinary procedures. There may be some discussion, however, as to whether animal drug or animal biologic regulations are more applicable. The products of animal genetic engineering, i.e., transgenic food animals and food products made from them, also raise important questions about product safety and identity. These include whether and how genetically engineered food animals will be subject to federal inspection for wholesomeness, whether artificial vectors, foreign genes, or gene products will adulterate recipient animal tissues, and how food products made from such animals will be labeled. Prior federal experience with the inspection of interspecific hybrids of cattle and buffalo provides a useful basis for further policy developments in the inspection and labeling of genetically engineered food animals. In particular, the inspection of cattle/buffalo hybrids has established a phenotypic (based on appearance) criterion for deciding how novel food animals should be inspected. As the genetic engineering of food animals on a production basis draws nearer, it may be necessary to supplement the phenotypic criterion with genetic (based on pedigree) criteria to assure that the essential characteristics of animals slaughtered under current food statutes are maintained.

Cytidine deaminase activity as a measure of acute inflammation in rheumatoid arthritis

Cytidine deaminase (CD), a cytoplasmic enzyme, is thought to leak out of damaged cells and can be measured in fluids by a simple biochemical assay. This study has shown that serum CD activity is raised in rheumatoid arthritis (RA) compared with osteoarthritis (OA). Synovial fluid (SF) CD activity was always less than the corresponding serum activity (mean SF/serum ratio = 0.6) in OA but up to 22 times greater than the corresponding serum activity in RA (mean SF/serum ratio = 13.1), suggesting CD production in inflammatory joints. Evidence to support the SF neutrophil as a cell of CD origin is provided by the CD gradient running from cells to SF to synovium. The close correlation between SF CD activity and neutrophil count (r = 0.93) indicates that SF CD activity is an accurate measure of acute synovial inflammation. Weak correlation of serum CD activity with erythrocyte sedimentation rate (ESR) (r = 0.44) and C-reactive protein (CRP) (r = 0.49) implies that CD estimations supply different though related information about rheumatoid disease activity. We suggest that CD released from damaged neutrophils diffuses from all inflamed joints into the blood, so that serum CD activity may provide an integrated measure of joint inflammation more specific than traditional measures such as the ESR.

The estimation of serum guanosine deaminase activity in liver disease

An assay for the estimation of guanosine deaminase is described. The method employs guanosine as substrate and after incubation of serum and substrate at 22 degrees C for 18 h the ammonia liberated is estimated using the Berthelot reaction. Absorbance is measured as 625 nm and the catalytic activity read from a standard curve obtained using ammonia standards. The method provides reproducible measurements of serum guanosine deaminase. The results obtained using 'normal' sera have been used to calculate the 'normal range' for the enzyme in serum. Preliminary results suggest that guanosine deaminase is increased in hepatitis and in patients with liver metastases but normal in all other liver diseases including cirrhosis and obstructive jaundice.

Serum deoxycytidylate deaminase as an index of high-risk pregnancy

Serum deoxycytidylate deaminase (EC 3.5.4.12, dCMP deaminase) activity was routinely estimated over 7 years in 2460 pregnancies. The results confirm that elevated dCMP deaminase activity (greater than 4.8 units) is associated with the development of pre-eclampsia but not with essential hypertension in pregnancy; a high rising level can precede eclampsia. Elevated enzyme activity was also found in women who developed jaundice in pregnancy and in some with apparently normal pregnancies. An unexpected finding was that these so called 'false positive' high levels were associated with all the unexplained intrauterine fetal deaths that occurred later in pregnancy. Although elevated dCMP deaminase levels may be associated with a normal outcome, persisting high levels indicate the need for careful monitoring of fetal well being and, in the presence of any other sign of placental insufficiency, delivery should be expedited.

Activity of serum cytidine deaminase during pregnancy

A simple and reliable method for the estimation of cytidine deaminase (cytidine aminohydrolase; EC 3.5.4.5) activity in pregnancy serum is described. This enzyme does not require magnesium for activation and is also more stable than deoxycytidylate deaminase (dCMP deaminase, dCMP aminohydrolase; EC 3.5.4.12). There was excellent correlation between the two enzymes (r = 0.92). Both enzymes showed increased activity in abnormal pregnancy. Both enzymes activities were found to be similar in 1305 maternal serum samples and therefore due to the simplicity of cytidine deaminase estimation it is recommended for the screening of large numbers of antenatal sera for abnormal pregnancies.

Biophysical cytochemical investigations of intracellular heparin in neoplastic mast cells

The thermodynamic binding parameters for intracellular heparin-acridine orange (AO) complexes were determined for Furth murine mastocytoma cells and were found to agree with 1) results from binding studies on heparin-AO complexes in solution, and 2) with biochemical analyses of the cells. The cells exhibited cooperative binding with a binding constant of 1.18 x 10(6) M-1. The cooperative binding constant of heparin-AO in 1 mM buffer was found to be 1.13 x 10(6) M-1. The addition of 1 mM NaCl to heparin-AO system in vitro detectably decreased the cooperative binding constant. Low ionic strength is the only condition in solution under which the cell and solution binding constants are equal. The cells have an average of 1.2 x 10(-14) mol of AO binding sites per cell. Using the biochemically measured heparin content per cell and the amount of AO bound by heparin in solution, 8 x 10(15) mol of sites/cell can be attributed to heparin. The remaining cellular binding sites (4 x 10(-15) mol of sites per cell) are essentially all accounted for by AO binding to DNA, the amount of which is calculated from its previously determined thermodynamic binding parameters. A theoretical isotherm, calculated from the binding parameters of both heparin-AO in solution and DNA-AO complexes in situ, agreed closely with the isotherm experimentally determined for the Furth mastocytoma cells. Ligand-binding analysis yields a binding constant, which may aid in identification of cellular bipolymers, and the number of ligand binding sites per cell. The latter is a measure of the amount of a given intracellular biopolymer present.

Obliteration of the ductus reuniens

The ductus reuniens was successfully obliterated in 52 guinea pig ears. Histopathological study showed that a majority of these specimens demonstrated cochlear hydrops, saccular collapse and normal utricle. These results support the theory of longitudinal flow of endolymph from the cochlea toward the endolymphatic sac via the ductus reuniens and saccule. A major source of endolymph in the saccule appears to be the scala media. In another set of 11 animals in which the ductus reuniens was first obstructed and two months later the endolymphatic duct was blocked, endolymphatic hydrops was shown in the cochleae, saccules, and utricles of all but one. The evidence suggests that cochlear hydrops was caused by obliteration of the ductus reuniens, and the saccular and utricular hydrops occurred subsequently as the result of blockage of the endolymphatic duct. Remnants of otolithic membrane which were attached to the distended saccular wall indicate that the membrane which had collapsed onto the macula after obliteration of the ductus reuniens is capable of subsequent distension. This experiment supports the concept of endolymph flow from the utricle and canals toward the endolymphatic sac. A blocked cutus reuniens might also explain the pathophysiological basis for the auditory form of Meniere's disease.

Stapedectomy. Postmortem findings

Histological studies were made of 16 temporal bones of 13 subjects who had stapedectomy operations. Photographs of the prostheses in situ are a special feature of the studies. It was found that prostheses which overlap the margins of the oval window cause incomplete closure of the air-bone gaps. Fibrous adhesions were a common consequence of trauma to the mucous membrane of the middle ear. Gelfoam implantation promotes the formation of thin oval window membranes which tend to bulge out of the oval window. Most incudes show small areas of cortical bone resorption. In at least half the cases the surgical technique of stapedectomy, as judged from these studies, was less than ideal. Surgeons who perform stapedectomy should be cognizant of the relevant surgical pathology and adopt methods which will optimize functional results and minimize complications.

Serum deoxycytidylate deaminase activity after myocardial infarction

The activity of serum deoxycytidylate deaminase, not hitherto reported to increase after myocardial infarction, has been investigated and the results have been related to other cardiac enzymes, including the MB fraction of creatine phosphokinase. Deoxycytidylate deaminase was found to increase to maximum activity on the third day after infarction. It may therefore be added to the list of 'cardiac enzymes.