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Biomedical subjects

D J Lamb

Publications and source records attributed to D J Lamb.

157 records · Page 9Linked to original sources
PubMedDate not supplied

Heat shock protein antibody titers are reduced by statin therapy in dyslipidemic subjects: a pilot study.

Antibody titers to heat shock protein (Hsp)-60 and -65 are positively related to risk of vascular disease and cardiovascular endpoints. There are few data on the factors that regulate the levels of these antibodies. It is known that the statins have antiinflammatory and immunoregulatory properties. The authors examined the effects of 2 statins, simvastatin (Zocor) and atorvastatin (Lipitor) on antibody titers to Hsp-60, -65, and -70 in a group of dyslipidemic patients. Twenty patients attending a lipid clinic, and previously not receiving lipid-lowering treatment, were treated with 10 mg of simvastatin (n = 11) or atorvastatin (n = 9) for 4 months. An additional 14 patients were recruited from the same clinic at the same hospital as a control group. The medication of these latter patients was unaltered for 4 months and the same parameters were measured as for the statin group. Antibody titers to Hsp-60, -65, and -70 were measured by enzyme-linked immunosorbent assay and lipoprotein profile and highly sensitive serum C-reactive protein (CRP) were measured by routine methods before and after treatment. Pretreatment and posttreatment data were compared by paired t or Mann-Whitney tests. Overall statin treatment was associated with a significant reduction in median antibody titers to Hsp-60 (17.2%, p = 0.03), Hsp-65 (15.9%, p = 0.003) and Hsp-70 (8.3%, p = 0.006), but not in control patients. Both statins caused a reduction in median serum CRP concentrations (45% overall, p < 0.05), but significant changes were not observed in the control patients. The effects on Hsp antibody titers were not related to changes in serum CRP concentrations (p > 0.05). However, there was a significant correlation between changes in antibody titers to Hsp-60 vs Hsp-65 (p < 0.01), Hsp-60 vs Hsp-70 (p < 0.05), and Hsp-65 vs Hsp-70 (p < 0.001). Statin treatment was associated with a reduction in antibody titers to Hsp-60, -65, and -70. This reduction is not fully explained by the antiinflammatory effects of the statins but may be due to their other immunomodulatory properties.

Adult↗
PubMedDate not supplied

Patient-assessed security changes when replacing mandibular complete dentures.

Twenty edentulous patients had unsatisfactory dentures replaced in a student clinic, using conventional techniques, under consultant supervision. Three visual analogue scale records of self-assessed mandibular denture security were made while the dentures were fabricated, and two were made following placement of the new dentures to measure any changes occurring. The method appeared reliable, and significant improvements in security were recorded. The percent increase in security and the coefficient of variation of the preplacement visual analogue scale scores were each inversely proportional to the preplacement visual analogue scale scores. This relationship may be useful in the identification of patients with special problems.

Aged↗
PubMedDate not supplied

Sertoli cell secretion of a factor that inhibits the incorporation of 3H-thymidine into cells in vitro.

Rat Sertoli cells secrete a low molecular weight factor in vitro that inhibits the incorporation of 3H-thymidine into cells. Although the addition of Sertoli cell-conditioned medium (rSCCM) resulted in nearly a threefold stimulation of cell growth, the incorporation of 3H-thymidine was decreased in a dose-dependent manner and did not reflect the increase in cell number. Peritubular cell- and germ cell-conditioned medium did not contain this inhibitory activity. Nor did the conditioned medium from fibroblasts and a variety of cell lines tested. A low molecular weight filtrate of rSCCM (< 1,000 Da) contained virtually all of the 3H-thymidine inhibiting activity, as well as about 50% of the mitogenic activity in the rSCCM. The inhibitory activity was eliminated upon removal of the rSCCM and was not due to either growth inhibition or a toxic effect on cell proliferation.

Animals↗
PubMedDate not supplied

Sertoli cell-conditioned medium affects nucleoside utilization in vitro.

Rat Sertoli cell-conditioned medium (SCCM) or low molecular weight filtrate of SCCM (< 1,000 Da molecular weight) inhibited the uptake of [3H]thymidine into cells in culture; [3H]thymidine is incorporated into DNA by means of a salvage pathway. The incorporation of radioactivity into DNA from [14C]N5,N10-methylene-tetrahydrofolate, required for the thymidylate synthetase reaction, was not inhibited by SCCM and reflected the increase in cell number. SCCM specifically inhibited the incorporation of pyrimidines ([3H]uracil, [3H]thymidine) with no effect on the transport or incorporation of [3H]adenosine. Inhibition of thymidine uptake by SCCM could have occurred by a direct competition, i.e., the secretion of thymidine into the medium by the Sertoli cells, or by an indirect mechanism that would result in an inhibition of transport. The activity was partially purified by membrane ultrafiltration, ion exchange chromatography, and sequential extraction. Addition of SCCM filtrate (< 1,000 Da molecular weight) to growth-arrested cells cultured in the presence of inhibitors of dihydrofolate reductase resulted in cell proliferation, suggesting that the factor is involved in thymidine biosynthesis. This activity may play a role in the regulation of nucleoside biosynthesis and/or utilization in the testis.

3T3 Cells↗
PubMedDate not supplied

Measurement of changes in complete mandibular denture security using visual analogue scales.

The security of mandibular dentures for edentulous patients has been quantified using a visual analogue scale. Relining "loose" dentures was shown to produce an increase in the patients' assessments of denture security for 21 out of 23 patients. The security of a denture after relining was found to correlate with the form of the residual mandibular ridge as measured by the mean anterior ridge height.

Alveolar Process↗
PubMedDate not supplied

Sertoli cell secreted growth factor. Cellular origin, paracrine and endocrine regulation of secretion.

Rat and human Sertoli cells in culture secrete a growth factor, Sertoli cell secreted growth factor (SCSGF). The aims of the present study were (1) to evaluate other testicular cell types as additional sources of SCSGF, as well as their paracrine effect, and (2) to study the hormonal regulation of SCSGF secretion using an A431 cell growth assay. The Sertoli cell was the only testicular cell type tested that secreted SCSGF activity in vitro. Peritubular cells enhanced Sertoli cell attachment and SCSGF secretion. Spermatogenic cells had no effect. The secretion of SCSGF was specifically stimulated by follicle-stimulating hormone (FSH) and testosterone. Treatment with agents that increase intracellular cAMP levels and adenosine stimulated the secretion of mitogenic activity into Sertoli cell-conditioned medium by three- to fivefold. This growth factor, secreted by the Sertoli cell and regulated by FSH and testosterone, may play a critical role in the regulation of spermatogenesis.

Adenosine↗
PubMedDate not supplied

Comparisons of patient self-assessment of complete mandibular denture security.

Records of self-assessed complete mandibular denture security were made by visual analogue scale, four-category functional scale, and by self-expressed satisfaction or dissatisfaction on 57 subjects that presented for replacement of complete dentures at an undergraduate clinic. Visual analogue scale scores formed two groups corresponding approximately to the groups of subjects expressing satisfaction or dissatisfaction with the current security of their dentures. The self-assessed visual analogue scale scores enabled variations in denture security to be quantified. Visual analogue scale scores of denture security were not normally distributed, but formed two separate distributions which corresponded approximately with the sets of satisfied (visual analogue scale > 50) and dissatisfied (visual analogue scale < 50) patients. The data showed that the visual analogue scale method was superior to the other two types of patient self-assessment.

Aged↗