Removal of Dental Biofilms with an Ultrasonically Activated Water Stream.

Acidogenic bacteria within dental plaque biofilms are the causative agents of caries. Consequently, maintenance of a healthy oral environment with efficient biofilm removal strategies is important to limit caries, as well as halt progression to gingivitis and periodontitis. Recently, a novel cleaning device has been described using an ultrasonically activated stream (UAS) to generate a cavitation cloud of bubbles in a freely flowing water stream that has demonstrated the capacity to be effective at biofilm removal. In this study, UAS was evaluated for its ability to remove biofilms of the cariogenic pathogen Streptococcus mutans UA159, as well as Actinomyces naeslundii ATCC 12104 and Streptococcus oralis ATCC 9811, grown on machine-etched glass slides to generate a reproducible complex surface and artificial teeth from a typodont training model. Biofilm removal was assessed both visually and microscopically using high-speed videography, confocal scanning laser microscopy (CSLM), and scanning electron microscopy (SEM). Analysis by CSLM demonstrated a statistically significant 99.9% removal of S. mutans biofilms exposed to the UAS for 10 s, relative to both untreated control biofilms and biofilms exposed to the water stream alone without ultrasonic activation (P < 0.05). The water stream alone showed no statistically significant difference in removal compared with the untreated control (P = 0.24). High-speed videography demonstrated a rapid rate (151 mm(2) in 1 s) of biofilm removal. The UAS was also highly effective at S. mutans, A. naeslundii, and S. oralis biofilm removal from machine-etched glass and S. mutans from typodont surfaces with complex topography. Consequently, UAS technology represents a potentially effective method for biofilm removal and improved oral hygiene.

The rise of social work in public mental health through aftercare of people with serious mental illness.

In the early years of the 20th century, social work's practice boundaries expanded to include direct work with people with the most serious mental illnesses through the function of aftercare. Using complementary and mutually reinforcing efforts to promote social reform in the care of people with mental illness and then to provide that care directly, the young social work profession established its presence in the emerging public mental health field and significantly broadened prevailing standards of acceptable care. This article presents a historical case analysis of the early events contributing to the identification of social work with aftercare and illustrates processes of creating professional "place" while influencing public perception of social needs relevant for the profession's continued growth and influence in the current reconfiguration of human services systems.

Prolactin induces expression of FGF-2 and a novel FGF-responsive NonO/p54nrb-related mRNA in rat lymphoma cells.

The rat Nb2-11C lymphoma cell line expresses high affinity prolactin (PRL) receptors, and requires lactogenic hormones for survival and proliferation. We have applied differential display to identify genes which are differentially induced in Nb2-11C cells following PRL stimulation, or which are constitutively expressed in the PRL-independent Nb2-Sp cells. In the present study we characterized a clone (22c.2) which was expressed in Nb2-Sp cells, and in Nb2-11C cells given PRL for 3 h but not in untreated cells. The 279 bp cDNA had 95% homology with the 3' end of the murine 2.6 kb FGF-inducible gene 14 (FIN14). When clone 22c.2 was used to screen a Nb2-Sp cDNA library to obtain a longer cDNA, a unique 1039 bp clone PNR (Prolactin-responsive/ NonO-Related) was isolated, subcloned and sequenced. The deduced amino acid sequence encoded by the PNR open reading frame had significant homology with a family of RNA- and DNA-binding proteins which include the human polypyrimidine tract-binding protein (PTB)-associated splicing factor (PSF), the murine non-POU-domain-containing octamer-binding protein (NonO) and the human NonO homologue p54nrb. Nb2-11C cells expressed three PNR-related mRNA transcripts of 2.5, 3.0 and > 10 kb. Expression of the 2.5 and 3.0 kb transcripts were increased at least 4-fold within 3 h of PRL treatment. PNR expression was also significantly stimulated within 3 h by addition of FGF-2 to either Nb2-11C or Nb2-Sp cells, although alone FGF-2 was not mitogenic for either cell line. Reverse transcription-polymerase chain reaction (RT-PCR) confirmed the expression of both FGF-2 and FGF receptor mRNA in Nb2 cells. raising the possibility of an autocrine or paracrine function for FGF-2 in lymphoma cells. Furthermore, PRL rapidly stimulated the expression of FGF-2 mRNA in a time- and dose-dependent manner in both Nb2-11C and Nb2-Sp cells. FGF-2 expression was increased within 1 h and was maintained at a high level for at least 10 h following treatment with 2 ng/ml PRL. Western blotting with anti-FGF2 antisera demonstrated PRL stimulation of intracellular accumulation, but not secretion of immunoreactive FGF-2. The observation of PRL-responsive expression of FGF-2 in Nb2 cells suggests a previously unrecognized pathway for PRL action in lymphoid cells.

FGF-2 antisense RNA encodes a nuclear protein with MutT-like antimutator activity.

Bidirectional transcription of the basic fibroblast growth factor (FGF-2) gene gives rise to multiple polyadenylated sense mRNAs and a unique 1.5 kb antisense transcript (FGF-AS) which is complementary to the 3'-untranslated region of the FGF-2 mRNA. The rat FGF-AS cDNA encodes a novel 35 kDa nuclear protein (GFG) with homology to the MutT family of antimutator NTPases. Antibodies against the deduced amino acid sequence of GFG detected intense immunoreactivity in the nuclei of adult rat hepatocytes. Subcellular fractionation and Western blotting confirmed the presence of a 35 kDa immunoreactive protein in the nuclear fraction and, to a lesser extent, in the mitochondrial fractions of rat liver homogenates. Recombinant GFG suppressed the spontaneous mutation rate of MutT-deficient E. coli in a complementation assay. In-frame deletion of the 53 amino acids encompassing the MutT domain eliminated this activity, confirming the catalytic function of this region in the FGF antisense gene product. These findings demonstrate for the first time that the FGF-AS transcript encodes a functional nuclear protein with MutT-related enzymatic activity.

Regulation of gene expression by natural antisense RNA transcripts.

The use of synthetic antisense oligonucleotides as specific inhibitors of gene expression exploits the susceptibility of mRNA to functional blockade at several levels, including mRNA processing, transport, translation and degradation. It is becoming increasingly apparent that the actions of these synthetic oligomers are analogous to those of endogenous RNA molecules involved in the regulation of gene expression in both prokaryotes and eukaryotes. A growing number of eukaryotic genes are now thought to be regulated at least in part by natural antisense RNA transcribed from the presumptive non-coding DNA strand. This possibility is supported by the presence of a complex system of double-stranded (ds) RNA-specific proteins and dsRNA-induced signal transduction pathways in eukaryotic cells. The presence of functional open reading frames in a number of recognized natural antisense RNA transcripts indicates that, in addition to regulating gene function at the RNA level, the antisense strand of many genes may code for as yet unidentified proteins. In the present study we review the current literature on the role(s) played by natural antisense RNA in eukaryotic cells, with an emphasis on genes for which clear evidence of regulation, or potential regulation by natural antisense RNA is available.

Characterization and tissue-specific expression of the rat basic fibroblast growth factor antisense mRNA and protein.

An RNA transcribed from the antisense strand of the FGF-2 gene has been implicated in the regulation of FGF-2 mRNA stability in amphibian oocytes. We have now cloned and characterized a novel 1. 1-kb mRNA (fgf-as) from neonatal rat liver. In non-central nervous system (CNS) tissues the fgf-as RNA is abundantly expressed in a developmentally regulated manner. The FGF-AS cDNA contains a consensus polyadenylylation signal and a long open reading frame (ORF) whose deduced amino acid sequence predicts a 35-kDa protein with homology to the MutT family of nucleotide hydrolases. Western blot analysis with antibodies against the deduced peptide sequence demonstrates that the FGF-AS protein is expressed in a broad range of non-CNS tissue in the postnatal period. In the developing brain, the abundance of sense and antisense transcripts are inversely related, suggesting a role for the antisense RNA in posttranscriptional regulation of FGF-2 expression in this tissue. The FGF-AS is complementary to two widely separated regions in the long 3' untranslated region of the FGF-2 mRNA, in the vicinity of the proximal and distal polyadenylylation sites. These findings demonstrate that the FGF-2 and fgf-as RNAs are coordinately transcribed on a tissue-specific and developmentally regulated basis and suggest that interaction of the sense and antisense RNAs may result in posttranscriptional regulation of FGF-2 in some tissues.

Decline in basic fibroblast growth factor (FGF-2) mRNA expression in female rat hypothalamus at puberty.

There is a growing acceptance of the importance of hypothalamic growth factors in the control of sexual maturation. Basic fibroblast growth factor (bFGF, FGF-2), a potent mitogen and neurotropic factor for brain cells in vitro, including hypothalamic cells, is widely expressed in the post-natal CNS but its physiological functions there are largely unknown. Previously, studies of FGF-2 mRNA regulation in vivo have been hampered by the low levels of FGF-2 mRNA present in post-natal tissues. We have applied a sensitive semi-quantitative procedure based on reverse transcription followed by polymerase chain reaction amplification (RT-PCR) to detect and estimate relative amounts of mRNAs encoding FGF-2 and its receptor in the hypothalamic-hypophyseal axis in individual female rats undergoing sexual maturation. FGF receptor and FGF-2 mRNAs were detectable in all brain regions examined. Injections of the glutamate agonist N-methyl-D-aspartic acid (NMDA) or pregnant mare's serum gonadotropin (PMSG) were used to advance the onset of puberty in immature female rats, and the levels of FGF-2 and FGF receptor mRNA in MBH and cortex were examined. Daily injections of NMDA (20 mg/kg) from day 24-28 resulted in advancement of first ovulation and vaginal opening (VO) in 5 of 9 treated rats. None (0/4) of the saline treated controls achieved first ovulation during the course of the experiment. Expression of FGF-2 mRNA in the medial-basal hypothalamus of the NMDA-treated VO animals, but not nonVO animals, was significantly (P<0.05) reduced by 50% vs saline-treated nonVO controls. There was no effect of NMDA on FGF-2 expression in cerebral cortex of VO Vs nonVO animals. FGF receptor mRNA levels were unaffected by NMDA treatment. To assess the possibility that the decline in hypothalamic FGF-2 mRNA levels was related to puberty and not just to an effect of NMDA, pregnant mare's serum gonadotropin was used to induce first ovulation and vaginal opening. Injection of PMSG to immature female rats on day 26 resulted in precocious first ovulation on day 29. This was accompanied by a significant 40% reduction in the steady-state level of FGF-2 mRNA in the medial basal hypothalamus compared to saline treated controls. As with NMDA treatment, PMSG did not affect FGF-2 mRNA abundance in the cortex, nor the FGF receptor mRNA in MBH or cortex. Immunohistochemical detection of FGF-2 protein in the arcuate nucleus revealed that FGF-2 immunoreactivity was also significantly modified in peri-ovulatory NMDA-treated animals. FGF-2 immunoreactivity in NMDA treated rats was significantly elevated at day 29 (the day of ovulation), but significantly inhibited by day 33. These findings suggest that alterations in the level of FGF-2 mRNA in the hypothalamus may be associated with first ovulation and the onset of sexual maturation in the female rat.

Shaping the policy practice agenda of social work in the field of aging.

This article argues that contemporary social work practice will, of necessity, involve a politically active stance. This stance will strengthen and redefine the relationship between legislative policy and social work practice in the field of aging. The urgency for such redefinition is fueled by the massive changes proposed and under way in Congress and by the increasing need for agencies to develop innovative programming, evaluate practice effectiveness, and compete for funding. Social work practitioners in all roles are challenged to refine or redefine their goals while remaining true to social work values and ethics.

Basic fibroblast growth factor binding and processing by human glioma cells.

Tumor cells of glial origin express high levels of basic fibroblast growth factor (bFGF) which stimulates their proliferation in an autocrine manner. In the present study we examined bFGF receptor (FGFR) expression and 125I-bFGF binding and processing in a human glioma cell line. RT-PCR demonstrated the co-expression of bFGF and FGFR mRNAs in five glioma cell lines examined. The high-affinity FGFR was visualized in U87-MG glioma cells by crosslinking with 125I-bFGF and by Western blotting with anti-receptor antisera. Both techniques identified a discrete 110-kDa moiety associated with the cell membrane, consistent with the reported size of one of the FGFR-1 isoforms. Western blotting also identified an intracellular receptor pool which was not accessible with exogenous 125I-bFGF. Suramin treatment induced a 2-fold increase in immunoreactive FGFR and a 1.5-fold increase in 125I-bFGF binding sites, indicating that FGFRs are chronically down-regulated by endogenous bFGF in U87-MG cells. Removal of extracellular bFGF with heparin resulted in a rapid, cycloheximide-sensitive increase in high-affinity bFGF binding sites. At 37 degrees C, receptor-bound 125I-bFGF was internalized and subjected to limited proteolytic cleavage over 12 h. U87-MG cells also contained abundant low-affinity bFGF binding sites which were removed by digestion with heparinase III but not by chondroitinase ABC. The presence of heparin (25 micrograms/ml) in the binding reaction eliminated the association of 125I-bFGF with the heparin-like sites but did not prevent binding to the high-affinity receptor. Scatchard binding analysis in the presence of heparin revealed a single class of high-affinity sites in U87-MG cells (Kd = 4.9 +/- 0.9 pM; 10-12 x 10(3) sites per cell). Neither heparin nor heparinase digestion prevented the binding of 125I-bFGF to the detergent-extractable high-affinity receptor, although both treatments significantly reduced the extent of 125I-bFGF association with the receptor. These findings indicate that in U87-MG cells, heparan sulfate proteoglycans may be involved in presentation of bFGF to the high-affinity receptor, but are not essential for high-affinity binding to occur.

Basic fibroblast growth factor sense (FGF) and antisense (gfg) RNA transcripts are expressed in unfertilized human oocytes and in differentiated adult tissues.

Basic fibroblast growth factor (bFGF) is a highly conserved and ubiquitously distributed mitogen. In amphibian oocytes bFGF mRNA is regulated post-transcriptionally by interaction with an antisense RNA transcript. We used reverse transcription-polymerase chain reaction (RT-PCR) and Northern hybridization to determine the presence of bFGF and its antisense RNA (gfg) in unfertilized human oocytes and postnatal differentiated tissues. BFGF and gfg transcripts were co-expressed in many tissues, with bFGF transcripts (7, 3.7 and 1.8 kb) being more abundant than the gfg transcript (1.5 kb) in 8 of 16 tissues examined. Sense and antisense expression was approximately equal in kidney and colon, while in heart, liver, skeletal muscle and testis gfg transcripts predominated. RT-PCR demonstrated the presence of bFGF and gfg transcripts in unfertilized oocytes where the antisense transcript was present in excess of the sense transcript. These findings suggest a role for gfg in regulation of bFGF expression.

Identification and characterization of an antisense RNA transcript (gfg) from the human basic fibroblast growth factor gene.

Basic fibroblast growth factor (bFGF) is an autocrine growth factor that is overexpressed in glial tumor cells and promotes their unregulated proliferation. We have previously reported that increased messenger RNA (mRNA) stability contributes to the elevated steady state levels of bFGF mRNA in human U87-MG glioma cells. Stability of bFGF mRNA is regulated by a natural antisense transcript in Xenopus oocytes, but the mammalian equivalent of this transcript has not previously been described. We were interested in identifying the human equivalent of this antisense transcript in order to study its role in bFGF mRNA stability. Analysis of the 3'-untranslated region of the 6.7-kilobase human bFGF mRNA revealed two areas of greater than 75% homology to exons 3 and 4 of the Xenopus antisense transcript, separated by 4300 basepairs of nonhomologous sequence. We used reverse transcription-polymerase chain reaction to amplify, clone, and sequence a 301-basepair fragment of the antisense splice variant from U87-MG cells. The clone (gfg-1) is 73% identical to the Xenopus sequence, with a conserved splice junction and an open reading frame. Strand-specific gfg-1 complementary RNA probes detect a 1.5-kilobase mRNA transcript in normal rat tissues and human T47D breast cancer cells, which contain very low levels of bFGF mRNA. In contrast, antisense transcript expression was undetectable by Northern hybridization in U87-MG cells, which overexpress the bFGF sense mRNA. The reciprocal relationship between bFGF sense and antisense expression suggests that antisense transcripts may regulate bFGF expression in mammalian cells, and that disruption of normal sense/antisense mRNA ratios may lead to overexpression of bFGF in some tumors.

Phosphorothioate antisense oligonucleotides against basic fibroblast growth factor inhibit anchorage-dependent and anchorage-independent growth of a malignant glioblastoma cell line.

Basic fibroblast growth factor (bFGF) is a broad spectrum mitogen for many cells of neuroectodermal origin, including glial cells. The human malignant glioblastoma cell line U87-MG expresses high steady state levels of the bFGF mRNA and contains abundant stores of biologically active bFGF protein. In the present study we have examined the contribution of endogenous bFGF to the autocrine growth of these cells. Using reverse transcription-polymerase chain reaction, U87-MG cells were shown to express the mRNAs for both bFGF and the bFGF receptor, confirming the existence of the basic requirements for an autocrine loop. Addition of 5 microM bFGF-specific antisense oligonucleotide to U87-MG cultures significantly inhibited the growth rate of these cells within 48 h and blocked proliferation beyond 2 days. The corresponding bFGF-specific sense oligonucleotide did not significantly inhibit cell proliferation over the course of these experiments. Similarly, antisense oligonucleotides significantly inhibited colony formation in soft agar, while the sense sequence was without effect. Western blotting with antihuman bFGF revealed that U87-MG cells synthesize three isoforms of bFGF, approximately 18, 23, and 25 kilodaltons (kDa) in size. The 23- and 25-kDa isoforms together comprise approximately 80% of the total cellular stores of bFGF. Antisense treatment for 4 days reduced the abundance of the 23- and 25-kDa isoforms by 64-74%, but had little effect on the 18-kDa isoform. The inhibitory effect of the antisense oligonucleotides on anchorage-dependent proliferation was reversed by the addition of recombinant 18-kDa human bFGF.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-Hodgkin's lymphoma of the central nervous system after treatment of Hodgkin's disease.

A case of a 34-year-old man with stage IIIB nodular sclerosis Hodgkin's disease complicated by the development of a central nervous system non-Hodgkin's lymphoma is described. The second tumor became symptomatic eight months after the initial diagnosis of Hodgkin's disease, but a tissue diagnosis was not made until autopsy two months later. The Hodgkin's disease was, at that time, in remission, and the autopsy revealed no persistent or recurrent Hodgkin's disease. Despite radiotherapy, the brain lymphoma had progressed to involve the spinal leptomeninges extensively, but there was no lymphoma outside the central nervous system (CNS) at autopsy. The significance of this unique case is discussed in light of the known risk for non-Hodgkin's lymphoma as a second malignancy after Hodgkin's disease and in view of recent information concerning CNS lymphoma.

Concomitant boost radiotherapy for advanced squamous cell carcinoma of the head and neck.

The concomitant boost technique is a variant of accelerated fractionation whereby the boost is delivered as a second daily fraction during the basic treatment course to reduce the total duration of treatment. From April 1972 through June 1983, 53 patients with advanced squamous cell carcinoma of various sites in the head and neck region were treated for cure at U.T. M. D. Anderson Hospital with this technique. In 12 patients, the concomitant boost was used because of rapid recurrence following surgical resection either before or after initiation of planned postoperative radiotherapy; the remaining patients had rapidly growing untreated or recurrent disease in the primary site, neck, or both. In most cases, the concomitant boost was delivered in fractions of 120-150 cGy, separated by 3-6 h from the basic daily treatment of 180-200 cGy. The boost treatments were given 2-3 times a week for 3-5 weeks, delivering an average of about 17 Gy in 12 fractions. Two different treatment techniques were used. Patients with predominantly neck disease (30) were treated with glancing AP and PA fields or with appositional electron beam portals to spare the mucous membranes, while those with advanced or rapidly progressive primary lesions, with or without nodal disease (23), received their concomitant boost through lateral photon or high energy electron beams to include the primary tumor site. As expected, the acute mucosal reactions were most severe in the latter group, but only three patients required interruption of treatment because of severe mucositis.(ABSTRACT TRUNCATED AT 250 WORDS)