Reducing Fluoroquinolone Use and Clostridioides difficile Infections in Community Nursing Homes Through Hospital-Nursing Home Collaboration.

Objective: Nursing homes (NHs) are an important target for antibiotic stewardship (AS). We describe a collaborative model to reduce Clostridioides difficile infections (CDIs) in NHs through optimization of antibiotic use including a reduction in high-risk antibiotics such as fluoroquinolones.

Design: Quasi-experimental, pre- and post-intervention study.

Gene expression by human articular chondrocytes cultured in alginate beads.

Culture of articular chondrocytes in alginate beads offers several advantages over culture in monolayer; cells retain their phenotype for 8 months or longer. Earlier studies of chondrocytes cultured in alginate concentrated on collagen and proteoglycan synthesis. However, gene expression by in situ hybridization (ISH) has not been investigated.

Cell attachment, collagen binding, and receptor analysis on bovine articular chondrocytes.

The purpose of this study was to investigate collagen receptors on primary bovine articular chondrocytes from full-thickness and different layers of bovine articular cartilage. Cytometric studies with antibodies showed that approximately 56% of the chondrocytes from the superficial layer and 29% of the chondrocytes from the deep layer bound anti-annexin V. A similar tendency was found for alpha5 and beta1 integrin antibodies.

Limitations of the SF-36 in a sample of nursing home residents.

Objective: to assess test characteristics of the Medical Outcomes Study SF-36 (Short-Form 36) with residents of nursing homes.

Research Design: nursing home residents with 17 or more points on the Mini-Mental State Examination (MMSE) and > or = 3 months residence (128 of 552 screened) were selected randomly. Interviewers administered the SF-36 (repeated after 1 week), Geriatric Depression Scale and MMSE.

Immunodetection and partial cDNA sequence of the proteoglycan, superficial zone protein, synthesized by cells lining synovial joints.

We have previously described a large proteoglycan named superficial zone protein that was isolated and purified from culture medium of superficial slices of bovine articular cartilage. Monoclonal antibodies were raised against superficial zone protein and used as probes in Western blot analyses for immunohistochemical studies both to determine precisely which cells within the joint synthesize the proteoglycan and to isolate a cDNA fragment from a bovine chondrocyte lambdagt11 library that encodes part of the proteoglycan. The cDNA fragment that was obtained with use of monoclonal antibody 6-A-1 encodes the 3' end of the sequence for superficial zone protein.

Articular cartilage superficial zone protein (SZP) is homologous to megakaryocyte stimulating factor precursor and Is a multifunctional proteoglycan with potential growth-promoting, cytoprotective, and lubricating properties in cartilage metabolism.

We have performed cDNA sequencing and homology analyses to elucidate the complete amino acid composition for a superficial zone protein (SZP) from human and bovine cartilage which has previously been shown to be a proteoglycan specifically synthesized by chondrocytes located at the surface of bovine articular cartilage and also some synovial lining cells. The results of this study indicate that cartilage SZP is homologous with a glycoprotein first described as the precursor protein of a megakaryocyte stimulating factor (MSF). Sequence comparisons and analyses indicate that (i) the amino acid composition of SZP is highly conserved between bovine and human species, (ii) SZP contains structural motifs at the N- and C-termini which are similar to those found in vitronectin and which may impart cell-proliferative and matrix-binding properties to the molecule, and (iii) SZP contains large and small mucin-like repeat domains composed of the sequences KEPAPTTT/P (76-78 repeats) and XXTTTX (6-8 repeats), respectively, which occur within a large central region of approximately 940 amino acids.

Combination of digital image analysis and polarization microscopy: theoretical considerations and experimental data.

The potentialities of polarization microscopy has been greatly increased by using specific stains for selective enhancement of the optical anisotropy of a macromolecular constituent of cells and tissues. Such stainings have proved to be especially useful in exploring the spatial orientation pattern of the extracellular matrix components. The retardation value, which characterizes quantitatively the degree of submicroscopic orientation, can be measured traditionally with a compensator plate.

Culture of chondrocytes in alginate gel: variations in conditions of gelation influence the structure of the alginate gel, and the arrangement and morphology of proliferating chondrocytes.

Sodium alginate, which gels in the presence of calcium ions, is commonly used for culture of anchorage-independent cells, such as chondrocytes. Normally, the gel appears microscopically homogeneous but, depending on the conditions of gelation, it may contain a varying number of small channels that extend inward from the surface. We have examined the influence of these channels on the morphology of cultured chondrocytes entrapped in alginate beads.

Effects of recombinant human osteogenic protein 1 on the production of proteoglycan, prostaglandin E2, and interleukin-1 receptor antagonist by human articular chondrocytes cultured in the presence of interleukin-1beta.

Objective: Recombinant human osteogenic protein 1 (OP-1) is an effective stimulator of human cartilage 35S-proteoglycan synthesis. The present study was conducted to determine whether stimulation of human articular chondrocytes with OP-1 can help overcome interleukin-1beta (IL-1beta)-induced suppression of 35S-proteoglycan synthesis.

Methods: Human articular chondrocytes in alginate beads were maintained for 3 days in the absence (control) or presence of IL-1beta at 0.

Recombinant human osteogenic protein 1 is a potent stimulator of the synthesis of cartilage proteoglycans and collagens by human articular chondrocytes.

Objective: To study the effects of recombinant human osteogenic protein-1 (rHuOP-1; bone morphogenetic protein-7) on proteoglycan and collagen synthesis by human articular chondrocytes.

Methods: Articular chondrocytes from fetal, adolescent, and adult human donors were cultured in alginate beads for 4 days in a mixture of Ham's F-12, Dulbecco's modified Eagle's medium, 10% fetal bovine serum (FBS), then for an additional 3-10 days in the presence and absence of rHuOP-1, with and without FBS. Chondrocyte synthetic activity was measured as the amount of incorporation of 35S-sulfate into proteoglycans and 3H-proline into hydroxyproline.

The superficial layer of human articular cartilage is more susceptible to interleukin-1-induced damage than the deeper layers.

Objective: To compare the responses of chondrocytes from superficial and deep layers of normal human articular cartilage to interleukin-1 (IL-1) and IL-1 receptor antagonist protein (IRAP), and to evaluate the binding sites for IL-1 on these cells.

Methods: Cartilage and chondrocytes from superficial and deeper layers of human femoral condyles were cultured with and without IL-1 in the presence and absence of IRAP. The effect of these agents on 35S- proteoglycan synthesis and catabolism and production of stromelysin and tissue inhibitor of metalloproteinases 1 (TIMP-1) were measured by biochemical and immunologic assays.

Evidence of an Eicosanoid Contribution to IL-1 Induction of IL-6 in Human Articular Chondrocytes.

It has been demonstrated previously that interleukin-1 (IL-1) induces articular cartilage explants and chondrocytes in culture to produce elevated levels of inflammatory mediators such as interleukin-6 (IL-6) and prostaglandins. Previous studies have also demonstrated a relationship between IL-6 secretion and the ability of IL-1 to modulate proteoglycan synthesis by chondrocytes. In this study we have utilized an alginate culture system in an effort to investigate a role for eicosanoids in IL-1 induction of IL-6 expression in human articular chondrocytes.

Effects of Misoprostol with Interleukin-1 on Proteoglycan Metabolism of Cultured Articular Chondrocytes.

Bovine and normal human articular chondrocytes in suspension culture were treated with misoprostol (an analog of prostaglandin E(1) [PGE(1)]), alone and in combination with interleukin-1 (IL-1) and/or diclofenac sodium, to study effects on proteoglycan metabolism. A concentrations of 50 ng ml(minus sign1) and above, misoprostol suppressed synthesis of proteoglycans but did not affect their rate of catabolism. The mild inhibitory effect of misoprostol on proteoglycan synthesis was additive to that of IL-1, especially in chondrocytes from the superficial zone of bovine articular cartilage.

Aggrecan synthesized by mature bovine chondrocytes suspended in alginate. Identification of two distinct metabolic matrix pools.

Proteoglycans synthesized by chondrocytes in alginate beads are found in two compartments: the cell-associated matrix and the further removed matrix (Häuselmann, H. J., Aydelotte M.

A novel proteoglycan synthesized and secreted by chondrocytes of the superficial zone of articular cartilage.

A novel proteoglycan (PG) has been identified in culture medium from thin slices of the superficial zone of bovine articular cartilage. This PG is synthesized and secreted selectively by chondrocytes of this zone but has not been demonstrated in culture medium from slices deeper in the same tissue. There is little, if any, incorporation of this PG into the extracellular matrix.

Phenotypic stability of bovine articular chondrocytes after long-term culture in alginate beads.

Articular chondrocytes embedded in alginate gel produce de novo a matrix rich in collagens and proteoglycans. A major advantage of this culture system is that the cells can be recovered by chelating the calcium, which otherwise maintains the alginate in its gel state. Chondrocytes thus released are surrounded by tightly bound cell-associated matrix, which seems to correspond to the pericellular and territorial matrices identified in cartilage by electron microscopy.

Coronary blood flow in senescent rats with late-onset hypertension.

We tested the hypothesis that the imposition of hypertension late in life would markedly limit maximal myocardial perfusion (MP). Young adult (8 mo) and senescent (24 mo) Fischer 344 rats were studied 3 mo after one-kidney, figure-8 renal wrap hypertension (RH) was induced. Sham-operated rats served as controls (Con).

Synthesis and turnover of proteoglycans by human and bovine adult articular chondrocytes cultured in alginate beads.

Human and bovine adult articular chondrocytes cultured in alginate beads or agarose gel retain their spherical shape and typical chondrocytic appearance for at least 5 weeks. Aggrecan is always the major population of proteoglycans (PGs) synthesized; its size varies depending upon the age of the cartilage from which the cells are derived but it is not influenced by the culture system used. Studies of human chondrocytes cultured in alginate showed that the majority of the newly-synthesized aggrecan molecules are rapidly incorporated into aggregates which can be extracted from the gel in their native form.

Late onset renal hypertension in old rats alters left ventricular structure and function.

This study was designed to test the hypothesis that the left ventricle of the senescent rat has a limited compensatory response to late onset hypertension. Data were obtained from middle-aged (15 mo) and senescent (24 mo) Sprague-Dawley rats either 1 or 3 mo after the initiation of one-kidney figure-8 renal wrap (Grollman) hypertension. Peak left ventricular (LV) function assessed during acute volume expansion was not markedly affected 1 mo after induction of hypertension with the exception of a decrement in the acceleration of aortic flow (dF/dt) in the senescent hypertensive group.

Influence of interleukin-1 on the morphology and proteoglycan metabolism of cultured bovine articular chondrocytes.

Bovine articular chondrocytes cultured in agarose gel in the presence of serum elaborated a highly organized extracellular matrix rich in proteoglycans and collagens. The cultures were evaluated quantitatively by radiosulfate labeling of proteoglycans, and by densitometry following staining with alcian blue. In addition, immunohistochemical methods were used to demonstrate the presence of several components of cartilage proteoglycan molecules.

Isolation and characterization of an abundant elastase inhibitor from NaCl extracts of bovine nasal septa and articular cartilage.

Extracts of cartilage have been reported to inhibit many serine proteinases and metalloenzymes. Such inhibition may be important in protecting cartilage against degradation by chondrocytic proteinases such as collagenase, stromelysin and by leukocytic proteases, such as elastase. We report here isolation and partial characterization of a 17-kD elastase inhibitor from 0.

Remodeling of coronary vessels during aging in purebred beagles.

We compared six young (1 year) and six senescent (11 years) purebred beagles to determine the effects of aging on the coronary microvasculature. The hearts were perfusion-fixed in vitro, and myocardial specimens were subjected to microscopic image analysis. Absolute left ventricular mass increased by 55% with age, while cardiocyte cross-sectional area increased by 10% and 30% in the midmyocardium and endomyocardium, respectively.

Articular cartilage matrix and structure: a minireview.

The ability of articular cartilage to undergo reversible deformation is dependent upon the organization of specific macromolecules within the extracellular matrix. This abundant matrix is elaborated by a small number of chondrocytes which maintain homeostasis via a synchronized balance between anabolism and catabolism. Type II collagen together with smaller amounts of other collagens form the fibrous network of the tissue in which are "entrapped" the aggregating proteoglycans in an underhydrated form.