Retention of dental sealants placed on sound teeth and incipient caries lesions as part of a service‐learning programme in rural areas in Mexico

International Journal of Paediatric Dentistry 2012; 22: 451–458 Background. Dental sealants are an effective treatment for the prevention and management of caries. Objective. To determine the retention of sealants placed in a rural setting in Mexico as part of an international service‐learning (ISL) programme and to determine associations between dental sealant’s retention and caries diagnosis at the time of sealant placement. Methods. Children aged 6–15 were examined for dental caries, received sealants by dental students as part of an ISL programme, and were re‐examined 4, 2, or 1 years after placement to assess sealant survival. Sealants were placed on permanent sound surfaces and enamel caries lesions [International Caries Assessment and Detection System (ICDAS) criteria]. Sealant survival was explored using Cochran–Mantel–Haenszel tests and multivariate prediction models. Results. 219 (46%) of 478 (mean age = 10.53 SD = 5.11) children who had received sealants returned for a recall examination (mean age = 10.89 SD = 3.11). After 1–4 years, 96.4% to 60.6% of the sealants placed on sound teeth had survived, and for sealants placed on surfaces with enamel caries lesions (ICDAS 1–3), 94.2% to 55.6% had survived. Differences were not statistically significant. Conclusions. Sealants had survival rates comparable to those previously reported in the literature. Sealants placed on sound and enamel caries lesions had similar survival rates.     

Ki67 LABELLING INDEX: AN INDEPENDENT PREDICTOR OF PROGRESSION IN PROSTATE CANCER TREATED BY RADICAL PROSTATECTOMY

The clinical course of prostate cancer is highly variable and cannot satisfactorily be predicted by histological criteria alone. Both tumour cell proliferation and neuroendocrine differentiation have been suggested as additional prognostic parameters, neuroendocrine differentiation being considered to enhance tumour cell proliferation. This study investigated the prognostic value of tumour cell proliferation [Ki67 labelling index (LI), MIB 1] and neuroendocrine differentiation and their relationship to each other. One hundred and thirty-seven paraffin-embedded radical prostatectomy specimens were examined. Neuroendocrine differentiation was found in 58 per cent of cases, but was not associated with pTN stage, Gleason score, Ki67 LI, or tumour progression. Ki67 LI was not significantly associated with pTN stage or with Gleason score. High grade ( P =0·0005), advanced local stage ( P =0·0004), positive lymph nodes ( P =0·02), and high Ki67 LI ( P =0·0203) were predictors of tumour progression if univariate analysis was performed, but Cox stepwise regression showed that only advanced local stage ( P =0·0025) and Ki67 LI ( P =0·0105) were independent predictors of tumour progression, the relative risk being 3·6 and 2·5, respectively. It is concluded that Ki67 is an important prognostic marker in prostate cancer with a potential for routine application.     

Presence of epidermal growth factor (EGF) receptor and proliferative response to EGF in six human ovarian carcinoma cell lines

Abstract. Scambia G, Benedetti Panici P, Battaglia F, Ferrandina G, Gaggini C, Mancuso S. Presence of epidermal growth factor (EGF) receptor and proliferative response to EGF in six human ovarian carcinoma cell lines. Int J Gynecol Cancer 1991; 1 : 253–258.
We investigated the role of the EGF-EGFR system as a regulator of ovarian cancer cell growth. In five (OVCA 433, OV 166, OV 1225, OV RS 1000, JA1) of six ovarian cancer cell lines examined we showed the presence of a single high-affinity ¹²⁵I-EGF binding site with Kd varying from 0.24 to 0.86 nM and a number of binding sites/cell from 9700 to 75 000. In OVCA 433, OV 166, and OV RS 1000 cells we demonstrated a low-affinity ¹²⁵I-EGF binding site with Kd ranging from 1.10 to 2.12 nM.
TR-170 cells lacked the EGF binding and were unresponsive to EGF in terms of cell proliferation while all EGFR+ cells except JA 1 exhibited a proliferative response to EGF. Moreover, the growth response of the four EGF-sensitive cell lines showed different patterns since at high EGF concentrations (100 ng ml⁻¹) there was no longer a stimulatory effect in OV 1225, OV 166, and OV RS 1000 cells while the mitogenic activity was still present in OVCA 433 cells.
Our results demonstrate that EGF plays a role in regulating ovarian cancer cell growth. However, the presence of EGFR is not a perfect indicator of the EGFR system functionality. The cell lines we have examined could be useful models to clarify the mechanism of EGF action and the role played by the EGF system in the onset and spread of ovarian tumors.     

Preparation and properties of des-Tyr98 and des-Arg97-Tyr98 acylphosphatase (muscular isoenzyme)

Previous NMR reports indicated that Tyr⁹⁸, the C-terminal residue of the muscular form of acylphosphatase, is likely to be part of the enzyme's active site. In addition, there is evidence that an arginine residue participates to the catalyzed reaction, possibly as phosphate binding site. Among all Arg residues present in the muscular forms of acylphosphatase, four, i.e. Arg²³, Arg⁷⁴, Arg⁷⁷, and Arg⁹⁷, appear to be conserved in all species checked thus far. We prepared the des-Tyr⁹⁸ and des-Arg⁹⁷-Tyr⁹⁸ derivatives of the native acylphosphatase to investigate the properties of both modified enzymes. The enzyme lacking Tyr⁹⁸ was found to be catalytically less effective than the native one, whereas the des-Arg⁹⁷-Tyr⁹⁸ acylphosphatase was completely inactive. This evidence suggests that Arg⁹⁷ participates directly to the active site catalytic mechanism. Fluorescence and CD spectra revealed that the latter enzyme could have been undergone some conformational change that could account for the loss of activity; on the other hand, the one-dimensional NMR spectra of either native and des-Arg⁹⁷-Tyr⁹⁸ enzymes were strictly similar, thus demonstrating that the removal of the two C-terminal residues does not markedly affect the fold of the enzyme. The results reported are proof of a critical contribution of Arg⁹⁷ to the acylphosphatase active site; however, we cannot exclude that the function of this residue is merely to stabilize the active site conformation and dynamics.     

Implantation of a Dual Chamber Pacemaker in a Patient with Persistent Left Superior Vena Cava

A patient underwent dual chamber pacemaker implantation by puncture of the left subclavian vein. During the procedure we observed persistence of the left superior vena cava. A "J-shaped" atrial lead was used for ventricular pacing with excellent long-term results. This technique can be a valuable alternative when confronted with the problem of persistent left superior vena cava during pacemaker implantation.