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Biomedical subjects

D J Lamb

Publications and source records attributed to D J Lamb.

At least 145 records · Page 8Linked to original sources
PubMed1982

Frequency of Candida albicans serotypes in patients with denture-induced stomatitis and in normal denture wearers.

A comparison has been made between the serotypes of oral Candida albicans taken from patients with denture-induced stomatitis and from a group of age and sex-matched controls. C albicans isolates were obtained from the fitting surface of the denture, the palatal mucosa supporting the denture, and the buccal mucosa. Twenty-nine of the 30 patients samples in the group affected by denture-induced stomatitis had only C albicans serotype A on their palatal mucosa and denture surface, while mixtures of serotypes were obtained from the buccal mucosa of these patients. Only one patient had serotype B isolates from the palatal mucosa and denture surface. In contrast, the control group had mixture of A and B serotypes from both the denture surface and the palatal mucosa, as well as from the buccal sites sampled. It would appear from these results that denture-induced stomatitis is associated with the proliferation of a single C albicans serotype, usually serotype A.

Candidiasis, Oral↗
PubMed1981

Temporal and quantitative correlations between nuclear androgen binding and stimulation of rna polymerase II activity in Sertoli cells.

The nuclear accumulation of 3H-androgen had been correlated with the effects of this steroid on nuclear RNA polymerase activity in the Sertoli cell under identical experimental conditions. The synthetic androgen methyltrienolone (R1881) was chosen to avoid ambiguities caused by metabolism of the radioligand. Nuclear accumulation of specifically bound 3H-R1881 was apparent after 5 min and preceded RNA polymerase II activation. RNA polymerase II activity was significantly increased by 10 min after administration of R1881, and the response was maximal at 15 min. Although nuclear binding of 3H-R1881 continued to increase over this interval, the enzyme activity declined to basal levels by 20 min. Saturation of nuclear binding sites required concentrations of R1881 that were approximately one order of magnitude higher than those required for maximal polymerase II activation at 15 min. The results indicate that occupancy of only a small fraction of the specific nuclear binding sites by androgen is required to elicit maximal elevation of RNA polymerase II activity in cultured Sertoli cells.

Animals↗
PubMed1980

The elastic modulus of soft denture liners.

Under certain circumstances, e.g., when treating "denture sore mouth" or after the provision of immediate dentures, dentures may be lined with soft rubberlike materials which have Young's moduli within the range congruent to 10(5) N m-2. Measurement of the compression modulus Ec of such soft liners is described and Gent and Lindley's method of calculating Young's modulus E was evaluated. It was established that the Young's modulus may be calculated using: Ec = E(1 + 2kS2), where k = 1 for soft rubbers, and for disks S is a shape factor and = radius/2 X thickness. It is also shown that Young's modulus is a linear function of log(rate of strain) for both tension and compression measurements. When gellation has occurred subsequent to mixing there is an increase in Young's modulus due to loss of ethanol. When immersed in brine the elastic modulus remains approximately constant from a day to a week or longer.

Denture Liners↗
PubMedDate not supplied

The genetics of male infertility: a field of study whose time is now.

Idiopathic male infertility is often associated with genetic and epigenetic abnormalities. Such abnormalities include chromosome translocations and aneuploidies, Y chromosome microdeletions, and mutations of the CFTR gene. The unraveling of the human genome and ongoing animal transgenic studies have identified numerous other genes likely to be associated with male infertility. Initial reports from human studies have identified several candidate genes, including the protamine genes, SPO11, EIF5A2, USP26, ACT, and others. In addition to gene mutations and polymorphisms, damage to the chromatin resulting in single and double strand DNA breaks affects fertility. Recent studies are highlighting the role of such abnormalities in male infertility, and point to protamine defects as one cause of DNA damage. Epigenetic abnormalities also are being investigated, including the role of residual sperm mRNA in embryogenesis, and the effects of abnormal spermatogenesis on gene imprinting. These studies are pointing to complex etiologies and clinical ramifications in many infertile men.

Animals↗