Malnutrition is Common and Increases the Risk of Adverse Medical Events in Older Adults With Femoral Fragility Fractures

BackgroundFemoral fragility fractures are one of the most common injuries managed by orthopedic surgeons. Malnutrition influences the poor outcomes observed in this population. Our purpose was to assess the annual trends of malnutrition diagnosis and determine risk factors for malnutrition and complications in patients 65 years and older presenting with femoral fragility fractures. We hypothesized that malnutrition would increase the risk of postoperative wound infection, wound dehiscence, non-union, and mortality.MethodsThe PearlDiver database was reviewed from 2010 to 2020. Patients ≥ 65-years-old with femur fractures treated with operative fixation were identified by CPT code. A preoperative diagnosis of malnourished state was defined by ICD-9 and ICD-10 codes and patients were divided into malnourished and non-malnourished cohorts. Patients were tracked for one year following operative fixation of a femoral fragility fracture for the occurrence of infection, wound dehiscence, nonunion and mortality. The rates of these complications were compared between malnourished and nonmalnourished cohorts.ResultsThere were 178,283 total femoral fragility fractures identified in patients aged 65-years or older. The overall prevalence of malnutrition diagnosis in this geriatric population was 12.8%. Documented malnutrition in femoral fragility fractures increased from 1.6% to 32.9% from 2010-2020 (P<0.0001). Compared to patients without malnutrition, patients with malnutrition are at increased risk of mortality (OR 1.31, 95% CI 1.2558 – 1.3752, p < 0.0001), are more likely to develop a wound infection (OR 1.49; 95% CI 1.252 – 1.7626; p < 0.0001), more likely to have a wound dehiscence (OR 1.55; 95% CI 1.3416 – 1.7949; p < 0.0001), and more likely to develop non-union (1.89; 95% CI 1.6946 – 2.1095; p < 0.0001). Multiple demographic variables were associated with malnutrition diagnosis including higher age, higher Charlson Comorbidity Index, female sex, dementia, and institutionalization. Parkinson’s disease, feeding difficulty and institutionalization demographic variables had the highest risk of malnutrition.ConclusionThe current study found that malnutrition diagnosis significantly increases the risk of adverse medical events in elderly adults with femoral fragility fractures. The rates of malnutrition increased steadily from 2010-2020. This trend is likely a result of increased awareness and testing for malnutrition, not reflecting an actual increased prevalence of malnutrition. Multiple expected demographic variables are associated with diagnosis of malnutrition. Level of Evidence: III     

FLAGELLAR ROOTS AND THE RESERVOIR CYTOSKELETON OF COLACIUM LIBELLAE (EUGLENOPHYCEAE)1

The three flagellar roots of Colacium Ehrenberg give rise to the three microtublar bands of the reservoir cytoskeleton. The dorsal root (DR) originates at the basal body (bb1) of the emergent flagellum. It is initiated on the left side of the cell, runs toward the right side under the posterior end of the reservoir and thence anteriorly in a spiral path over the dorsal surface of the reservoir until it terminates on the left side of the eyespot. Along its length, it appears to initiate a dorsal band (DB) which forms the major dorsal portion of the reservoir cytoskeleton—the dorsal microtubules (DMT). Two roots originate at the basal body (bb2) of the non-emergent flagellum. The ventral root (VR) runs up the left side of the cell and initiates the band of microtubules which forms part of the presumptive vestigial cytopharynx. Therefore, it forms the reinforcing microtubules (MTR) of Colacium. The intermediate root (IR) forms the para-reservoir microtubules (PMT). Flagellar root correlation with the reservoir cytoskeletal bands strengthens their homologies with the bodonid bands and further supports the hypothesis that the euglenoids are derived from the kinetoplastid flagellates.     

High-performance liquid chromatographic procedure for the quantitative determination of paclitaxel (Taxol) in human plasma

An isocratic high-performance liquid chromatographic method has been developed and validated for the quantitative determination of paclitaxel (Taxol^®), a novel antimitotic, anticancer agent, in human plasma. The analysis required 0.5 ml of plasma, and was accomplished by detection of the UV absorbance of paclitaxel at 227 nm following extraction and concentration. The method involved extraction of paclitaxel from plasma, buffered with 0.5 ml of 0.2 M ammonium acetate (pH 5.0), onto 1-ml cyano Bond Elut columns. The eluent was evaporated under nitrogen and low heat, and reconstituted with the mobile phase, acetonitrile-methanol-water (4:1:5, v/v/v) containing 0.01 M ammonium acetate (pH 5.0). The samples were chromatographed on a reversed-phase octyl 5 μm column. The retention time of paclitaxel was 10 min. The validated quantitation range of the method was 10–1000 ng/ml (0.012–1.17 μM) of paclitaxel in plasma. Standard curve correlation coefficients of 0.995 or greater were obtained during validation experiments and analysis of clinical study samples. The observed recovery for paclitaxel was 83%. Epitaxol, a biologically active stereoisomer, and baccatin III, a degradation product, were also chromatographically separated from taxol by this assay. The method was applied to samples from a clinical study of paclitaxel in cancer patients, providing a pharmacokinetic profiling of paclitaxel.     

A surface active protein involved in aerial hyphae formation in the filamentous fungus Schizophillum commune restores the capacity of a bald mutant of the filamentous bacterium Streptomyces coelicolor to erect aerial structures

The filamentous bacterium Streptomyces coelicolor undergoes a complex process of morphological differentiation involving the formation of a dense lawn of aerial hyphae that grow away from the colony surface into the air to form an aerial mycelium. Bald mutants of S. coelicolor, which are blocked in aerial mycelium formation, regain the capacity to erect aerial structures when exposed to a small hydrophobic protein called SapB, whose synthesis is temporally and spatially correlated with morphological differentiation. We now report that SapB is a surfactant that is capable of reducing the surface tension of water from 72 mJ m^?2 to 30 mJ m^?2 at a concentration of 50 μg ml^?1. We also report that SapB, like the surface-active peptide streptofactin produced by the species S. tendae, was capable of restoring the capacity of bald mutants of S. tendae to erect aerial structures. Strikingly, a member (SC3) of the hydrophobin family of fungal proteins involved in the erection of aerial hyphae in the filamentous fungus Schizophyllum commune was also capable of restoring the capacity of S. coelicolor and S. tendae bald mutants to erect aerial structures. SC3 is unrelated in structure to SapB and streptofactin but, like the streptomycetes proteins, the fungal protein is a surface active agent. Scanning electron microscopy revealed that aerial structures produced in response to both the bacterial or the fungal proteins were undifferentiated vegetative hyphae that had grown away from the colony surface but had not commenced the process of spore formation. We conclude that the production of SapB and streptofactin at the start of morphological differentiation contributes to the erection of aerial hyphae by decreasing the surface tension at the colony surface but that subsequent morphogenesis requires additional developmentally regulated events under the control of bald genes.     

COLONIZATION AND REPRODUCTION OF THE EPIBIOTIC FLAGELLATE COLACIUM VESICULOSUM (EUGLENOPHYCEAE) ON DAPHNIA PULEX1

The epibiotic flagellate Colacium vesiculosum Pringsheim attaches to planktonic species of Daphnia in freshwater habitats. Previous studies found that prevalence (percentage of substrate organisms carrying attached epibionts) and intensity (number of attached epibionts on a given substrate organism) are low early in the Daphnia intermolt period and are high late in the intermolt period. We tested the hypothesis that increases of Colacium cells attached to Daphnia occur both by rapid initial and continuous colonization and by cell reproduction. Epibiont prevalence and intensities were determined at successive intermolt stages of Daphnia pulex Leydig collected from freshwater ponds in Colorado. Colonization was continuous throughout the intermolt period and was most important to epibiont population increase at the beginning of the intermolt period. Cell division was the major contributor to epibiont increase at the end of the intermolt period.     

Molecular cloning and structural analysis of the phosphate translocator from pea chloroplasts and its comparison to the spinach phosphate translocator

Using an 5-AvaII fragment of the spinach (Spinacia oleracea L.) phosphate translocator cDNA as a probe for a hybridization screening of a pea (Pisum sativum L.) cDNA library we have cloned and sequenced a cDNA clone coding for the phosphate translocator precursor protein from pea chloroplasts. The full-length cDNA clone comprises 42 base pairs (bp) at the 5-non-coding region, a 1206-bp coding region corresponding to a polypeptide of 402 amino-acid residues (relative molecular mass 43 671) and 244 bp at the non-coding 3-region. Determination of the N-terminal sequence of the phosphate translocator from both pea and spinach chloroplasts revealed that the transit peptides consist of 72 and 80 amino-acid residues, respectively. These transit peptides are different from those of other chloroplastic transit peptides in that they both contain an amphiphilic -helix which is located either in close proximity to the processing site in pea or at the N-terminus in spinach. The mature proteins from pea and spinach both contain about 87% identical amino-acid residues and about seven putative membrane-spanning -helices. Some of these -helices have an amphiphilic character and might serve to form a hydrophilic translocation channel through the membrane. The in-vitro synthesized pea precursor protein is directed to the chloroplast and inserted into the chloroplast envelope membrane.Abbreviations bp base pairs - kDa kilodaltons - M_r relative moleculas mass - SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis We wish to thank Dr D. Pappin and R. Jakes (AFRC Sequencing Laboratory, Department of Biochemistry, University of Leeds, UK) for performing the N-terminal sequence determinations and are greatful to Dr J. S. Gantt (Botany Department, University of Georgia, Athens, USA) for a pea leaf cDNA library and to Professor J. C. Gray (University of Cambridge, Department of Botany, Cambridge, UK) for helpful discussions. This work was supported by the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie, the Science and Engineering Research Council and the Royal Society. D.L.W. was the recipient of the Royal Society Rosenheim research fellowship and K.F. was supported by a fellowship from the Studienstiftung des deutschen Volkes.     

Histones inhibit human chorionic gonadotrophin-stimulated but not atrial peptide-stimulated testosterone production and cyclic nucleotide formation by isolated mouse Leydig cells

Recently it has been reported that histone type H2A can inhibit gonadotrophin-stimulated cAMP formation and steroidogenesis by ovarian cells. In the present study we have investigated if similar antigonadotrophic effects of commercially available histones can also be demonstrated on testicular steroidogenic cells. Using percoll-purified mouse Leydig cells, we have demonstrated that several types of histones could almost completely inhibit hCG-stimulated testosterone production and cAMP formation. The inhibition was dose-dependent and could be reversed by the addition of excess of hCG. The most potent histone types were H2AS and H8S, both of which could inhibit hCG-stimulated cAMP formation half-maximally at concentrations of 4-5 micrograms/ml. Forskolin-stimulated cAMP formation was not affected by histones. When the cells were stimulated with either db-cAMP or rAP-II, histone H2AS and H8S failed to inhibit the testosterone production. In fact there was a marked increase in the amount of testosterone produced, the reason for which is not yet understood. The amount of cGMP accumulated in response to rAP-II was not affected by the presence of H2AS or H8S. In unstimulated cells, neither the cyclic nucleotide level nor the amount of steroid produced was affected by the histones. Based on the [125I]hCG binding data it is possible to conclude that histone H2AS inhibits the binding of hCG to its receptors on Leydig cells and thereby causes the inhibition of hCG-stimulated cAMP formation and steroidogenesis.     

Functional interaction of constant and variable domains of human immunodeficiency virus type 1 gp120.

A previously reported amino acid substitution within the second conserved domain of the human immunodeficiency virus type 1 (HIV-1) gp120 envelope results in the production of noninfectious particles. Molecular characterization of spontaneous revertant viruses, which arose during long-term cocultures of this env mutant, revealed that an amino acid change within another region of gp120 could functionally compensate for the mutation and restore infectivity. In the current study, we have introduced a conservative amino acid substitution at this second-site revertant codon and observed a marked reduction in HIV-1 infectivity. During the passage of this defective virus in cocultures, yet another revertant appeared which contained an amino acid change within a variable region of gp120 which restored infectivity to near wild-type levels. These results, in combination with other point mutations that have been introduced into the HIV-1 envelope, suggest that at least three discrete regions of gp120 may interact during the establishment of a productive viral infection. This critical step occurs subsequent to the adsorption of virions to the cell surface and either prior to or concomitant with the fusion of viral and cellular membranes.     

COLACIUM LIBELLAE SP. NOV. (EUGLENOPHYCEAE), A PHOTOSYNTHETIC INHABITANT OF THE LARVAL DAMSELFLY RECTUM1

Colacium libellae sp. nov., in the non-flagellated palmella stage and lacking stalks, lines the cuticle of the rectum of damselfly larvae, forming a conspicuous green plug. In culture this species forms highly-branched colonies of stalked cells. The cells tire often elongated to twice the size of most motile cells (40–50 × 6–10 μm), with parallel sides and rounded apices. These features are distinctive when comparisons are made among clones of related species in soil-water-pea medium. C. libellae established itself in the rectum of previously Colacium-free larvae of the damsel fly Anomalagrion hastatum whereas a clone of C. vesiculosum and C. mucronatum did not.