Biomedical subjects
M Grace
Publications and source records attributed to M Grace.
A new BDA structure. British Dental Association.
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What progress has been made in meeting the needs of seriously maltreated children? The course of 200 cases through the Boston Juvenile Court.
OBJECTIVES: The study examined child, parent, and case characteristics in a sample of 200 cases of serious child maltreatment brought before the Boston Juvenile Court (BJC) on Care and Protection petitions in 1994. Whether recent changes in Massachusetts law have been effective in reducing delays in adjudication and helping children achieve permanent placements more quickly was also examined. METHOD: Data were abstracted from court records by the research team. The 200 cases were followed prospectively for 4 years. Retrospective data on the families' previous involvement with the protective service system were also abstracted from the records. Data from the 1994 cases were compared to that obtained from a sample of cases brought before the BJC in 1985-1986. RESULTS: Children permanently removed from parental custody in the 1994 sample required less time post-disposition to achieve permanent placements. However, overall, time frames for the 1994 cases remained remarkably similar to those in 1985-1986: children were in the protective service system an average of 5 years; cases required an average of 1.6 years in court; and half of the children permanently removed from parental custody were still in "temporary" foster care at 4-year follow-up. CONCLUSIONS: Although some improvements have occurred since 1985-1986, the system still fails to meet the needs of seriously maltreated children to achieve permanent placements promptly. The implications of the findings for system reform are discussed.
Chromosomal non-disjunction in human oocytes: is there a mitochondrial connection?
The frequency of chromosome abnormalities due to non-disjunction of maternal chromosomes during meiosis is a function of age, with a sharp increase in the slope of the trisomy-age curve between the ages of 30 and 40 years. The basis of this increase, which is a major cause of birth defects, is unknown at present. In recent years, mutations in mitochondrial (mt) DNA have been associated with a growing number of disorders, including those associated with spontaneous deletions of mtDNA (deltamt DNAs). Intriguingly, these pathogenic deltamtDNAs, which are present at extremely high levels in certain patients, are also present at extremely low levels (detectable only by polymerase chain reaction) in normal individuals. The proportion of such deltamtDNAs in normal muscle is a function of age; the shape of this curve is exponential, with the accelerating part of the curve beginning at approximately 30-40 years. We postulate that, as well as muscle and brain, a similar time-dependent accumulation of deltamtDNAs also occurs in normal oocytes. Since deltamtDNAs are functionally inactive, an accumulation of such aberrant genomes could eventually compromise ATP-dependent energy-utilization in these cells. Furthermore, these deficiencies would also affect the function of the somatic follicular cells that surround, and secrete important paracrine factors to, the oocyte. If there is indeed an age-associated relationship between deltamtDNAs and oocyte age, perhaps errors in meiosis (which is almost certainly an energy, and ATP, dependent process) are related to mutations in mtDNA (primarily deletions, but perhaps point mutations as well) in oocytes and/or the surrounding somatic cells, which result in deficiencies in both mitochondrial function in general and oxidative energy metabolism in particular. This hypothesis would explain many of the non-Mendelian features associated with maternal age-related trisomies, e.g. Down's syndrome.
Rubella virus vaccine associated arthropathy in postpartum immunized women: influence of preimmunization serologic status on development of joint manifestations.
OBJECTIVE: To measure preimmunization rubella virus (RV)-specific IgG levels and to relate these to the development of acute and chronic (persistent or recurrent) joint manifestations following rubella vaccination. METHODS: Specific IgG was determined by whole RV enzyme immunoassays (EIA) (Abbott Rubazyme and M33, an in-house method), immunoblot, neutralization domain peptide (BCH-178c) EIA, and neutralization bioassay in prevaccine samples of 268 RV seronegative women (Abbott absorbance < 0.999 units) who had received monovalent live attenuated RA27/3 strain RV vaccine in a clinical trial that recorded joint manifestations. RESULTS: Of rubella vaccinated women tested for prevaccine antibodies, 21.7% were actually positive (> or = 10 IU/ml) by M33 EIA, 33.2% had Abbott values > or = 0.250 units, and 47.6% had RV protein-specific antibody (immunoblot), while only 17.6% were positive (> or = 10 IU/ml) by neutralization domain peptide EIA and 12.7% had neutralization titers > or = 1:8. Seropositivity by the various methods was compared to recorded occurrence of acute and chronic arthropathy (arthralgia and/or arthritis) after RV vaccination. Relative to women who had no joint manifestations, prevaccine seropositivity rates for subjects with acute arthropathy were significantly (p < 0.05) lower in the Abbott test (< 0.250 units), BCH-178c peptide EIA, and neutralization bioassay, while those who also developed chronic arthropathy had significantly lower prevaccine seropositivity rates for the Abbott (< 0.250 units) and M33 EIA and neutralization bioassay. CONCLUSION: Results suggest that risk for arthropathy following RA27/3 rubella vaccination may be higher in women who have very low prevaccine levels of antibody, particularly in assays measuring functional (neutralizing) antibodies.
Effect of denture cleansers, surface finish, and temperature on Molloplast B resilient liner color, hardness, and texture.
PURPOSE: The purpose of this study was to compare color, texture, and Shore A hardness of a resilient silicone denture liner with as-polymerized, roughened, or pumiced surfaces after treatment with perborate-, persulfate-, or hypochlorite-containing denture cleansers at 25 degrees or 55 degrees. MATERIALS AND METHODS: Fifty-eight specimens that each exhibited an as-polymerized, a roughened, and a pumiced area were exposed to 5 different commercially available perborate-, persulfate-, or hypochlorite-containing denture cleansers at 25 degrees or 55 degrees continuously for 4 (1/2) months. The solutions were replaced twice a day. Control specimens were soaked in water with no cleanser. Before and after the 4 (1/2) -month cleaning regimen, the color, hardness, and texture of resilient liner surfaces were evaluated using a color densitometer, a Shore A durometer (Shore Instrument & Mfg Co, Freeport, NY), and a surface profilometer, respectively. Differences among groups after the cleanser treatment were determined using a repeated measures analysis of variance (alpha = 0.05) and a Tukey's Honestly Significant Difference post hoc test. RESULTS: Roughened specimen surfaces after 25 degrees or 55 degrees cleanser treatment exhibited significant color loss with some perborate-containing cleansers compared with the control. Roughened specimens treated at 55 degrees with perborate-containing cleansers also exhibited significantly greater color loss than those treated with the persulfate-containing cleanser. With roughened surfaces, significantly greater hardness was found with some perborate-containing cleanser compared with a hypochlorite-containing cleanser after treatment at 25 degrees. No differences were observed in surface texture based upon cleanser treatment. CONCLUSION: After silicone resilient denture liner treatment with certain perborate-containing denture cleansers, a greater amount of components could leach from the liner leading to a loss of color if the liner surface is rough.
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The letters section of the British Dental Journal has always been one of the most popular sections, confirmed yet again by our latest Readership Survey. This is possibly because letters are an instant reflection of popular opinion as well as an opportunity for research to be checked and questioned by those in the field.
Was it worth it?
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Immortalization of primary human keratinocytes by the helix-loop-helix protein, Id-1.
Basic helix-loop-helix (bHLH) DNA-binding proteins have been demonstrated to regulate tissue-specific transcription within multiple cell lineages. The Id family of helix-loop-helix proteins does not possess a basic DNA-binding domain and functions as a negative regulator of bHLH proteins. Overexpression of Id proteins within a variety of cell types has been shown to inhibit their ability to differentiate under appropriate conditions. We demonstrate that ectopic expression of Id-1 leads to activation of telomerase activity and immortalization of primary human keratinocytes. These immortalized cells have a decreased capacity to differentiate as well as activate phosphorylation of the retinoblastoma protein. Additionally, these cells acquire an impaired p53-mediated DNA-damage response as a late event in immortalization. We conclude that bHLH proteins play a pivotal role in regulating normal keratinocyte growth and differentiation, which can be disrupted by the immortalizing functions of Id-1 through activation of telomerase activity and inactivation of the retinoblastoma protein.
Expression of the HPV E7 oncoprotein mimics but does not evoke a p53-dependent cellular DNA damage response pathway.
Acute expression of the human papillomavirus E7 oncoprotein in preimmortal human fibroblasts induces changes in the abundances of multiple cellular regulatory proteins. These alterations include a destabilization of the retinoblastoma tumor suppressor protein pRB, stabilization of the tumor suppressor protein p53, and increases in the level of the cyclin-dependent kinase inhibitor p21(cip1). Since the HPV E7 oncoproteins can interfere with several cell cycle checkpoints and similar alterations in the levels of pRB, p53, and p21(cip1) are also observed in a p53-dependent response to DNA damage, we investigated whether E7 expression triggers this signal transduction pathway. The results demonstrate that E7-mediated destabilization of pRB does not require p53 activity and is independent of the ability of E7 to induce apoptosis. Moreover, E7-mediated increases in p21(cip1) levels are largely p53-independent and involve stabilization of the p21(cip1) protein. In contrast the decreases in pRB expression in response to DNA damage involve transcriptional downregulation of RB gene expression.
The CPD Project. Continuing professional development.
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