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PubMed2000

Influence of behavioral science research on oral health promotion.

To realize the benefits of advances in preventive and problem-focused dentistry, patients must carry out specific oral health behaviors. The behaviors range from seeking preventive care, to keeping appointments, to carrying out home-based self-care regimens. Unfortunately, rates of these behaviors are less than optimal and maximizing patient involvement in dental care is a major challenge facing dentistry. In fact, poor rates of patient adherence remains a significant problem in all areas of health care. Aspects of the treatment regimen itself as well as provider and patient actions impact these outcomes. Theoretical models grounded in the behavioral sciences provide useful frameworks for understanding the process of health behavior change that can be applied to patient care. Research in health promotion and disease prevention have identified a number of psychological, social, and environmental issues related to oral health behaviors and outcomes, including personal barriers, social support, stress and coping, health beliefs, and dental anxiety. These barriers are discussed, and examples of interventions that have incorporated theoretical models and behavioral outcomes and linking them to oral health are provided. Future directions of the expanding area of behavioral science and oral health promotion in clinical practice are discussed.

Behavioral Sciences↗

PubMed1990

Direct laser and laser-thermal irradiation of normal canine coronary arteries: implications for laser delivery methods.

Clinical use of laser recanalization has been mostly limited by arterial perforation. Two modifications of the optical fiber were used to decrease the perforation rate: (1) a guidewire to align the fiber in a coaxial position with the vascular lumen and (2) encapsulation of the optical fiber tip with a metal cap. Fourteen dogs were studied. Argon laser radiation was delivered through optical fibers, 9 with a 1.7-mm metal encapsulated fiber (Laserprobe-PLR,¿ Trimedyne, Santa Ana, CA) and 5 with a 2-mm metal encapsulated fiber with a window at the tip (Spectraprobe-PLR). Three dogs served as control, and no guidewire was used. In 11 dogs, laser irradiation was done either in advancing the probe or on pullback over a guidewire. Energy used ranged from 25 to 50 J. In vitro, this raised the probe temperature in blood to a maximum of 500 degrees C. Arterial perforation occurred in 2 of 4 lased arteries without guidewire (p less than 0.05). There was no difference in perforation rated comparing the Laserprobe (1 out of 17 arteries) and Spectraprobe (1 out of 8 arteries) (p greater than 0.05). At high laser energy (50 J), there was an increased incidence of thrombus formation, which appeared to be associated with adherence of the metal cap to the arterial wall (3 out of 6 vs. 1 out of 19, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Laser↗

PubMed1982

Gliding motility of Cytophaga sp. strain U67.

Video techniques were used to analyze the motion of the gliding bacterium Cytophaga sp. strain U67. Cells moved singly on glass along the long axis at a speed of about 2 micrometers/s, advancing, retreating, stopping, pivoting about a pole, or flipping over. They did not flex or roll. Cells of different lengths moved at about the same speed. Cells sometimes spun continuously about a pole at a frequency of about 2 HZ, the body moving in a plane parallel to that of the glass or on the surface of a cone having either a large or a small solid angle. Polystyrene latex spheres moved to and fro on the surfaces of cells, also at a speed of about 2 micrometers/s. They moved in the same fashion whether a cell was in suspension, gliding, or at rest on the glass. Two spheres on the same cell often moved in opposite directions, passing by one another in close proximity. Small and large spheres and aggregates of spheres all moved at about the same speed. An aggregate moved down the side of a cell with a fixed orientation, even when only one sphere was in contact with the cell. Spheres occasionally left one cell and were picked up by another. Cell pretreated with small spheres did not adhere to glass. When the cells were deprived of oxygen, they stopped gliding, and the spheres stopped moving on their surfaces. The spheres became completely immobilized; they no longer moved from cell to cell or exhibited Brownian movement. Cytophaga spp. are known to have a typical gram-negative cell envelope: an inner (cytoplasmic) membrane, a thin peptidoglycan layer, and an outer (lipopolysaccharide) membrane. Our data are consistent with a model for gliding in which sites to which glass and polystyrene strongly adsorb move within the fluid outer membrane along tracks fixed to the rigid peptidoglycan framework.

Cell Membrane↗

PubMed1993

Pseudomonas aeruginosa pili bind to asialoGM1 which is increased on the surface of cystic fibrosis epithelial cells.

The basis for the unique association of Pseudomonas aeruginosa and the cystic fibrosis (CF) lung has remained obscure despite major advances in the understanding of the molecular genetic cause of this disease. There is evidence to suggest that abnormalities in CF transmembrane conductance regulator function result in alterations in the glycosylation of epithelial components. The number of asialoGM1 residues, as representative of a class of glycolipids which contain a GalNAc beta 1-4Gal sequence for P. aeruginosa attachment, was quantified by flow cytometric studies of respiratory epithelial cells in primary culture from both CF patients and normal subjects. Superficial asialoGM1 was detected on 12% of the CF cells as compared with 2.9% of the cells from normal control subjects (P = 0.03, chi 2 = 4.73), and more asialoGM1 residues were exposed on CF cells after modification by P. aeruginosa exoproducts. AsialoGM1, but not the sialylated glycolipid GM1, was demonstrated to be a receptor for 125I-labeled P. aeruginosa pilin, a major adhesin for this organism, and exogenous asialoGM1 was found to competitively inhibit P. aeruginosa adherence to epithelial cells, thus, confirming the biological role of the asialoGM1 receptor. Quantitative and qualitative differences in the sialylation of superficial glycolipids in CF epithelial cells may directly contribute to the colonization of the CF lung by P. aeruginosa.

Bacterial Adhesion↗

PubMed2003

Effect of thrombus on abdominal aortic aneurysm wall dilation and stress.

AIM: Our goal is to understand how a mural thrombus may influence the pressure transmitted to and the dilation experienced by the abdominal aortic aneurysm (AAA) wall. METHODS: Two intact AAAs with mural thrombus were removed from patients and pressurized to 100 mmHg. The pressure was measured using a micro-tip needle transducer inserted in the aneurysm wall and advanced through the thrombus. In 1 patient with AAA, similar measurements were made in vivo. Also, in vitro, in the two aneurysms the dilation as a function of pressure was measured using the markers on the surface before and after the thrombus was removed. RESULTS: Both, in vitro and in vivo, in the presence of the thrombus the pressure transmitted to the aneurysm wall was 91+/-10% of luminal pressure and at 6 mm from the wall it was 96+/-5%. The aneurysm dilated more in the pressure range of 0-40 mmHg (2-8%) than in the range of 40-100 mmHg (0.4-1.8%). Upon removal of the thrombus these dilations increased significantly to 4-15% and 0.9-3.3%, respectively. Overall, the strains (dilation) in the circumferential and longitudinal directions were similar before the thrombus was removed. CONCLUSIONS: Even though the thrombus allows the transmission of luminal pressure to the aneurysm wall, it may prevent the aneurysm from rupture by diminishing the strain on the wall. Consistent with this, a mechanical model of the thrombus proposed is "a thrombus as a fibrous network adherent to the aneurysm wall".

Aged↗

PubMed1997

Unmasking by soluble IL-6 receptor of IL-6 effect on metastatic melanoma: growth inhibition and differentiation of B16-F10.9 tumor cells.

Interleukin-6 (IL-6) inhibits the growth of melanocytes and of early stage melanoma cells, but not that of advanced melanoma cells. The in vitro IL-6 response can be restored in the highly metastatic melanoma B16-F10.9 by addition of recombinant soluble IL-6 receptor alpha-chain (sIL-6R). The F10.9 cells then undergo irreversible growth-arrest and show increased adherence with changes from epithelioid to spindleoid morphology. The sIL-6R is required for IL-6 to induce a sustained activation of the various Stat transcription factors which bind to specific IL-6 inducible enhancers. The sIL-6R and IL-6 combination causes an increase in the level of the anti-oncogenic transcription factor IRF-1 protein and DNA-binding, which remain elevated for 24 h. The promoter activity of the anti-oncogenic p21/Waf-1/Cip-1 gene is induced and accumulation of the p21 protein is observed. These results illustrate the potent agonist activity of sIL-6R on molecular pathways which could mediate the growth-arrest and differentiation of the metastatic melanoma cells. Previously observed antimetastatic effects of IL-6 therapy in mice bearing F10.9 tumors may be at least partly due to direct growth inhibition and differentiation elicited by sIL-6R present in biological fluids.

Animals↗

PubMed2000

Molecular epidemiology: recent advances and future directions.

In 1982 we proposed the concept and a framework for implementing molecular cancer epidemiology. Here, we review progress during the past 17 years in validating and applying this approach to cancer prevention. There have been major advances, notably in the understanding of environment-susceptibility interactions in human cancer. However, a review of major findings to date reveals several urgent research needs to keep pace with the rapid evolution in knowledge of mechanisms in carcinogenesis. Although much valuable progress continues to be made in the study of carcinogens that cause direct DNA damage and are mutagenic, exogenous and endogenous carcinogens can also act by altering gene expression, cell proliferation and differentiation. The mechanisms include aberrant DNA methylation, oxidative damage, effects on metabolism of nitrogen oxide and nitrites, activation of receptors and transcription factors, cyclins and other cell cycle proteins. Sensitive, validated biomarkers are needed to detect these mechanisms in small numbers of cells, tissues or fluids. There is also increasing recognition that individual risk from carcinogen exposure varies as a function of both inherited and acquired factors. Recent advances in genomics, microassay technologies and informatics hold promise for rapid identification of polymorphic variants or changes in expression of genes influencing both response and susceptibility to carcinogens. Another emerging area of molecular epidemiology concerns the role of nutrition and specific dietary factors (including studies on antioxidants, energy metabolism, insulin and various growth factors) and the modulating effect of genetic polymorphisms. Finally, molecular epidemiology has enormous potential in cancer prevention through the early identification of 'at risk' populations and the rapid assessment of intervention efficacy. Its success in fully reaching this potential will depend on the application of validated biomarkers, with adherence to sound epidemiologic and ethical principles.

Carcinogens↗

PubMed2002

Effect of endothelial cell polarity on beta-amyloid-induced migration of monocytes across normal and AD endothelium.

During normal aging and amyloid beta-peptide (Abeta) disorders such as Alzheimer's disease (AD), one finds increased deposition of Abeta and activated monocytes/microglial cells in the brain. Our previous studies show that Abeta interaction with a monolayer of normal human brain microvascular endothelial cells results in increased adherence and transmigration of monocytes. Relatively little is known of the role of Abeta accumulated in the AD brain in mediating trafficking of peripheral blood monocytes (PBM) across the blood-brain barrier (BBB) and concomitant accumulation of monocytes/microglia in the AD brain. In this study, we showed that interaction of Abeta(1--40) with apical surface of monolayer of brain endothelial cells (BEC), derived either from normal or AD individuals, resulted in increased transendothelial migration of monocytic cells (HL-60 and THP-1) and PBM. However, transmigration of monocytes across the BEC monolayer cultivated in a Transwell chamber was increased 2.5-fold when Abeta was added to the basolateral side of AD compared with normal individual BEC. The Abeta-induced transmigration of monocytes was inhibited in both normal and AD-BEC by antibodies to the putative Abeta receptor, receptor for advanced glycation end products (RAGE), and to the endothelial cell junction molecule, platelet-endothelial cell adhesion molecule-1 (PECAM-1). We conclude that interaction of Abeta with the basolateral surface of AD-BEC induces cellular signaling, promoting transmigration of monocytes from the apical to basolateral direction. We suggest that Abeta in the AD brain parenchyma or cerebrovasculature initiates cellular signaling that induces PBM to transmigrate across the BBB and accumulate in the brain.

Aged↗

PubMed2001

Handheld digital equipment for weight composite distress paradigms: new considerations and for rapid documentation and intervention of rodent populations.

Animal care in the third millennium will require a melding of scientific and humane interests to achieve optimal care of genetically engineered mice and to expedite scientific and medical advances by using these mammals. Undoubtedly, rodent patients present certain difficulties for those who wish to assess their daily well-being and to contribute to efficient and successful scientific discovery. High-density housing, large experimental groups, and low-lux room lighting makes the application of large-animal care standards to rodents seem daunting to researchers and veterinary care programs. In addition, great variability in training and experience among those responsible for the direct application of humane care to rodents exists. Most of the direct animal care in small animal facilities occurs in decentralized locales by personnel who have completed obligatory but relatively minimal animal care training. Examples of personnel in this category include postdoctoral fellows, junior-level scientists, summer students, and assistant laboratory animal technologists. Some programs even use the husbandry staff to perform health checks of high-risk populations on a daily basis. For this reason, the extrapolation of performance-based intervention in rodent care is difficult to apply practically. Early efforts to enhance humane outcome in rodents have been published by scientists and veterinarians and are largely directed at singular endpoints, such as weight loss and declining temperatures, in specific models. Scientists often are reluctant to accept such standards because of concern about premature intervention or variability between scorers and to reservations regarding a lack of procedural likeness with their proposed study. This paper highlights a digital method for melding current advanced animal scoring standards using palm pilot user-friendly methods that account for composite weight scoring, behavioral or physiologic attributes, and interventions. Information is rapidly downloaded and results in quick storage of large rodent population monitoring. This minimizes interpretative variability between caregivers and greater standardization of procedures. These considerations facilitate the rapid diagnosis of outliers and make possible intervention that streamlines the delivery of humane care to large experimental populations.

Animal Technicians↗

PubMed1995

Over-expression of human sex steroid-binding protein (hSBP/hABP or hSHBG) in insect cells infected with a recombinant baculovirus. Characterization of the recombinant protein and comparison to the plasma protein.

Human sex steroid-binding protein (hSBP/hABP or hSHBG) was over-expressed in High Five and Sf9 cells adhered to plates and in suspension. The adherent cells expressed to levels of 2.3 mg/l and 1.4 mg/l after 4 and 6 days, respectively, while Sf9 cells grown in suspension yielded 4.67 mg/l after 6 days. Recombinant hSBP/hABP, purified to homogeneity by immunoadsorption, was found to fold similarly to native plasma hSBP/hABP and to display similar sequence epitopes after heat denaturation. The recombinant protein binds dihydrotestosterone, testosterone, and 17 beta-estradiol with KdS of 0.6, 2.4, and 14.2 nM, respectively, which are similar to plasma hSBP/hABP. The recombinant protein contains N-linked and O-linked oligosaccharide side-chains but the monomer exhibits a slightly lower molecular weight than plasma hSBP/hABP (40 kDa vs 44 kDa) which may be due to the absence of one N-linked side-chain or to shorter oligosaccharide side-chains. The partial N-terminal sequence LRPVLP(T)Q of recombinant hSBP/hABP is identical to plasma hSBP/hABP but appears to be less heterogeneous. These results indicate that recombinant baculovirus SBP represents a good model for investigating the structure of plasma hSBP/hABP. The expression system will allow the isolation of preparative amounts of SBP mutants generated by combinatorial site-directed mutagenesis to advance investigations on structure-function relationships and undertake crystallization trials for X-ray diffraction analyses.

Amino Acid Sequence↗

PubMed2001

Efferent arteriole tubuloglomerular feedback in the renal nephron.

BACKGROUND: Afferent and efferent arteriole resistance exerts critical and opposite actions in the regulation of glomerular capillary pressure (PGC) and glomerular filtration rate (GFR). Tubuloglomerular feedback (TGF) plays an important role in the regulation of afferent arteriole resistance; however, the role of TGF in the regulation of efferent arteriole resistance is less well established. We hypothesized that TGF caused by increased NaCl in the tubular fluid stimulates the macula densa to initiate a cascade of events resulting in efferent arteriole vasodilation, mediated by adenosine via its A2 receptor. METHODS: Rabbit efferent arterioles and adherent tubular segments with macula densa were simultaneously microperfused in vitro while changing NaCl concentration at the macula densa. To study whether autacoids produced by the glomerulus participate in the effect of TGF on efferent arterioles, they were perfused orthograde or retrograde. To eliminate the hemodynamic influence of the afferent arteriole during orthograde perfusion, the perfusion pipette was advanced to the distal end of the afferent arteriole, and the tip of the pressure pipette was placed beyond the afferent arteriole; for retrograde perfusion, the efferent arteriole was perfused from its distal end. RESULTS: In efferent arterioles perfused orthograde and preconstricted with norepinephrine (NE), increasing NaCl concentration at the macula densa increased the diameter by 33%. In preconstricted efferent arterioles perfused retrograde, increasing NaCl at the macula densa increased the diameter by 33%. Efferent arteriole vasodilation was completely blocked by a selective adenosine A2 receptor antagonist (3, 7-dimethyl-1-propargylxanthine) but not by an adenosine A1 receptor antagonist (FK838). CONCLUSIONS: Our data show that in vitro, preconstricted efferent arterioles dilate in response to increased macula densa NaCl, and this process is mediated by activation of adenosine A2 receptors. Thus, TGF changes efferent arteriole resistance in the opposite direction from the afferent arteriole, possibly amplifying TGF regulation of PGC and GFR. In vivo efferent arteriole TGF may only buffer the signals that cause efferent arteriole resistance to parallel changes in afferent arteriole resistance. Effects of TGF on efferent arterioles perfused orthograde or retrograde were similar, suggesting that glomerular autacoids do not participate in this process.

Animals↗

PubMed1981

Locomotion of Xenopus epidermis cells in primary culture.

The locomotion of single epidermis cells, grown out from Xenopus laevis tadpole tails has been investigated by time-lapse cinemicrography using phase-contrast and reflection-contrast optics. The cells develop a large, mostly 200-250 nm thick, lamella, which adheres homogeneously to the supporting coverglass and exceeds the projection area of the cell body. From the comparison of RIC-pictures taken at high (1.06) and low (0.62) numerical aperture of illumination (I.N.A.) we deduce that at low I.N.A. the embossment of the medium-facing side of the lamella is visualized. By this method microcolliculi are demonstrated, which form at the edge of the lamellipodium and move backward. They resemble ruffles, but are flatter and no membrane flow towards the perinuclear region is observed. Indirect immunofluorescence reveals an enhanced staining for actin and alpha-actinin in the lamellipodium and in the transition region of cell body and lamella. Tonofilaments do not participate in lamella formation, the relatively few microtubules seem to be oriented in the direction of cytoplasmic flow. Electron micrographs demonstrate the course of fibrils in the cell body and a meshwork of actin filaments and membranous tubules in the lamella. Based on these findings a model for cell locomotion is presented: the motive force is generated by the cell body causing a flow of cytoplasm towards the periphery and extension of the lamella at its edge. The activity of the lamellipodium has to ensure the flat form of the advanced edge; microcolliculi are assumed to represent a small membrane store for the extension of the lamella. The lamellipodium is not involved in the production of motive force. The cell body is anchored to the lamella by radiating fibrils and the fibrillar meshwork is inserted at the 'dorsal' membrane of the lamella and the basal filament cortex of the cell body. This anchorage provides the structural basis for the uptake of lamella material into the cell body in the transition region.

Animals↗

PubMed2001

Main findings and conclusions of the implementation of Directive 76/464/CEE concerning the monitoring of organic pollutants in surface waters (Portugal, April 1999-May 2000).

The purpose of this paper is to relate the implementation of Directive 76/464/CEE concerning the survey of priority dangerous substances and indicate the main priority pollutants encountered throughout a systematic monitoring program carried out in Portugal during a period of 14 months (April 1999-May 2000). Contrary to what it seems, the implementation of such a Directive is not straightforward owing to the large number of compounds and samples to be analyzed at trace levels. During this period of time, 115 priority semivolatile organic compounds (SVOCs), 41 volatile organic compounds (VOCs), six organotin compounds, 14 heavy metals, phosphate, nitrates, nitrites and ammonia were determined in 644 surface water samples (corresponding to 14 months and 46 sites). In addition, priority SVOCs were also determined in sediment, mussels and fish (muscle and liver). This paper reports the procedure and analytical tools used and necessary to determine the levels of 115 priority toxic and persistent semivolatile organic compounds selected from the EC Council Directive list (76/464/EEC). An advanced analytical protocol was developed involving enrichment of water samples in Oasis solid-phase extraction cartridges (SPE) in the Lisbon laboratory with a Gilson ASPEC XL automated extraction system and by sending the enriched cartridges to Barcelona by aeroplane at 4 degrees C, where elution and analysis were performed. Final determination was performed with gas chromatography-electron ionization mass spectrometry (GC-EI-MS). Acidic herbicides were determined by liquid chromatography with diode array detection. Owing to the great amount of data generated throughout the monitoring study, statistical analysis of the more representative contaminants was performed, allowing the identification of the more relevant contamination sources, percentages of findings and the description of their temporal and spatial (geographical) distributions. Recommendations and compounds that should be included in future monitoring programs are given.

Environmental Monitoring↗

PubMed1994

The role of cyclic AMP, calcium and filamentous actin in adenosine modulation of Fc receptor-mediated phagocytosis in human neutrophils.

The role of cyclic AMP, calcium and filamentous actin (F-actin) content during adenosine modulation of Fc receptor (FcR)-mediated phagocytosis in adherent human neutrophils was investigated. Phagocytosis of IgG-opsonized yeast particles was found to be enhanced by pico- to nanomolar concentrations of adenosine or the A1-agonist N6-cyclopentyl-adenosine (CPA) but reduced by micromolar concentrations of adenosine or the A2-agonist 5'-N-ethylcarboxamidoadenosine (NECA). NECA, in the presence of the cAMP-specific phosphodiesterase inhibitor Ro 20-1724, increased the intracellular content of cAMP during phagocytosis. Ro 20-1724 potentiated the NECA-induced reduction of the phagocytic capacity. These observations indicate that cAMP elevations are involved in A2-receptor-mediated inhibition of phagocytosis. NECA, in the presence of Ro 20-1724, markedly enhanced the action polymerization associated with adhesion to the substrate and contact with the phagocytic prey. During advanced phagocytosis, however, the F-actin content reached levels clearly below those observed in control cells. This prolonged depolymerization phase correlated with the A2-receptor-induced cAMP elevation. Depletion of intracellular free calcium abolished the cAMP-elevating effects of NECA, and also completely abrogated the A1- and A2-receptor-mediated effects on phagocytosis. However, since NECA reduced the F-actin content even in Ca(2+)-depleted cells, A2-receptor-mediated inhibition of phagocytosis could not be directly coupled to changes in the overall content of F-actin. Our results indicate that adenosine modulates FcR-mediated phagocytosis in a calcium-dependent way, and does so through 'stimulatory' A1 and 'inhibitory' A2 receptors, and also that cAMP elevation is linked to the A2-receptor-induced inhibition of phagocytosis.

4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone↗

PubMed2003

Human immunodeficiency virus infection in pregnancy.

The transformation of the human immunodeficiency virus (HIV) epidemic over the last 20 years has been remarkable. With access to appropriate therapies, clinicians can now offer infected women a much improved prognosis as well as a very high likelihood of birthing children who will be HIV uninfected. However, these advances are purchased through the use of complicated, expensive medical regimens (highly active antiretroviral therapy) that are associated with a litany of toxicities and risks. In caring for HIV-infected pregnant women and prescribing these medications, obstetricians must always bear in mind their dual responsibilities, providing optimal care to the mother and reducing the likelihood of mother-to-child transmission of HIV. To accomplish those goals, the physician must first monitor the patient's immunological and virological status including resistance testing. The results of those tests will guide the clinician in choosing when to initiate therapy and in deciding whether to use regimens directed solely at transmission interruption or those that will simultaneously treat the mother's infection. When using highly active antiretroviral therapy, physicians must be cognizant of the pregnancy-specific risks associated with some of the component agents. The core goal of all medical therapy is to bring the patient's viral load to an undetectable level. When that goal is reached, the chance of transmission to the child is minimized, the need for a cesarean delivery is reduced, and the patient's prognosis is optimized. However, if a woman is not pregnant, then the initiation of therapy can be delayed because long-term adherence with medications can be difficult, side effects are not uncommon, and prognosis is not adversely affected so long as the CD4 count and the viral load remain in a reasonable range. None of the advantages cited above can be achieved unless all women have their HIV status determined as early in pregnancy as possible.

Antiretroviral Therapy, Highly Active↗

PubMed2006

Early appearance of stem/progenitor cells with neural-like characteristics in human cord blood mononuclear fraction cultured in vitro.

OBJECTIVE: The exposure of human umbilical cord blood mononuclear cells devoid of hematopoietic stem cells (HUCB-MNCsCD34-) to defined culture condition promotes their conversion into neural lineage. We have asked the question if observed fate change of HUCB-MNCsCD34- results from direct conversion of hematopoietic precursors into neural-like phenotypes due to expression of overlapping genetic program or, alternatively, these neural phenotypes arise from sequential differentiation of more primitive progenitors (embryonic-like cells) preexisting in HUCB-MNCsCD34- fraction. MATERIALS AND METHODS: HUCB-MNCs negatively selected for CD34 antigens were cultured in vitro up to 14 days. Changes in stem/neural cell genes and proteins were successively evaluated during this period and after evoked neuronal differentiation of cells in the presence of RA or BDNF or cocultured with neonatal rat brain astrocytes. RESULTS: Freshly isolated HUCB-MNCsCD34- expressed pluripotent cell markers: Oct3/4, Sox2, and Rex1 genes. During 24 hours of culture the frequency of Oct3/4 immunopositive cells increased markedly with parallel enlargement of "side population" and CD133+ cell appearance. Concomitantly, cultured cells start to form aggregates and express pro-neural genes, i.e., enhanced Sox2, OTX1, Nestin, GFAP, and NF-200. During the next days of culture immunoreactions for beta-tubulin III, MAP2, GFAP, S100beta, Doublecortin, and GalC were induced with reciprocal lowering of stem cell gene and protein markers. At this stage cells successively adhered to the bottom, dispersed, and decreased proliferation rate (Ki67 expression). Additional treatments with neuromorphogenes or coculturing with rat brain primary culture induced further differentiation of these neural precursors toward more advanced neuronal phenotypes. CONCLUSIONS: HUCB-MNCs(CD34-) fraction contains embryonic-like stem/progenitor cells which increase rapidly but transiently in culture, then differentiate spontaneously after cell aggregate adhesion toward neural lineage. Neurally promoted cells from 10-14 DIV culture acquire three main neural-like phenotypes, i.e., neurons, astrocytes, and oligodendrocytes. In this respect they are promising candidates for experimental treatment of neuronal injury; however, the final proof for conversion of HUCB cells to neural cells can be obtained through transplantation experiments.

Animals↗

PubMed1985

Management of seventh and eighth nerve involvement by cerebellopontine angle tumors.

Microsurgical techniques have made a significant contribution in the advancement of surgery. Since then, the field of neurosurgery has made great and rapid strides. Neurosurgeons now venture through the deep and delicate regions of the brain where they dared not venture only a few years ago. In particular, the morbidity and mortality of surgery in the CPA has seen a progressive decrease. This presentation deals with 200 consecutive tumors in the CPA operated on using microsurgical techniques during the last 6 years. One hundred sixty-seven (83.5%) of them were acoustic neuromas (which included 12 patients with bilateral tumors). Of the remaining 33, there were 21 meningiomas, 10 epidermoids, and 2 angioblastomas. Preoperative investigation has been aimed at arriving at a diagnosis which is as exact as possible in order to plan the operative strategy. All patients, ranging in age from 16 to 84, have been operated upon in the lounging position (with the necessary precautions) through a unilateral suboccipital craniectomy. The basic surgical technique, irrespective of the tumor, is to decompress it from within in order to relieve its tension and pressure on surrounding nerves, vessels, and the brain stem. The structures which are only compressed are spontaneously relieved of compression. This helps define their full anatomic course. Having been identified, they are protected from damage. The most adherent points between tumor and nerves are recognized and handled last under direct vision when there is sufficient space to allow manipulation of the tumor. In the rare event of the facial nerve being interrupted, nerve graft procedures are attempted during the same operation. Our experience with the technique of intracranial-intratemporal facial nerve grafting has yielded excellent results. The cochlear nerve lacks a Schwann cell cover in the CPA and is more prone to being affected, either by tumor processes or surgical manipulation. Of our 167 acoustic nerve tumors, 60% were larger than 3 cm in diameter. The two important factors with regard to predicting the preservation of the seventh and eighth cranial nerves are tumor size (less than 3 cm) and preoperative hearing loss (less than 40 dB). The preservation of facial nerve function after tumor removal was achieved in 87.8% of patients. The facial nerve was preserved in all patients with other tumors. With regard to hearing ability the overall result of preservation of function was achieved in 27.6%. However, when a low hearing loss (less than 40 dB) and small tumor size (less than 3 cm) are taken into account, the preservation was as high as 58%.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗

PubMedDate not supplied

Processes for managing pathogens.

Wastewater contains human, animal, and plant pathogens capable of causing viral, bacterial, or parasitic infections. There are several routes whereby sewage pathogens may affect human health, including direct contact, contamination of food crops, zoonoses, and vectors. The range and numbers of pathogens in municipal wastewater vary with the level of endemic disease in the community, discharges from commercial activities, and seasonal factors. Regulations to control pathogen risk in the United States and Europe arising from land application of biosolids are based on the concept of multiple barriers to the prevention of transmission. The barriers are (i) treatment to reduce pathogen content and vector attraction, (ii) restrictions on crops grown on land to which biosolids have been applied, and (iii) minimum intervals following application and grazing or harvesting. Wastewater treatment reduces number of pathogens in the wastewater by concentrating them with the solids in the sludge. Although some treatment processes are designed specifically to inactivate pathogens, many are not, and the actual mechanisms of microbial inactivation are not fully understood for all processes. Vector attraction is reduced by stabilization (reduction of readily biodegradable material) and/or incorporation immediately following application. Concerns about health risks have renewed interest in the effects of treatment (on pathogens) and advanced treatment methods, and work performed in the United States suggests that Class A pathogen reduction can be achieved less expensively than previously thought. Effective pathogen risk management requires control to the complete chain of sludge treatment, biosolids handling and application, and post-application activities. This may be achieved by adherence to quality management systems based on hazard analysis critical control point (HACCP) principles.

Agriculture↗