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Biomedical subjects

A P Wade

Publications and source records attributed to A P Wade.

At least 19 recordsLinked to original sources
PubMed2003

Applications of Fourier transform infrared microspectroscopy in studies of benign prostate and prostate cancer. A pilot study.

Fourier transform infrared (FTIR) microspectroscopy has been applied to a study of prostate cancer cell lines derived from different metastatic sites and to tissue from benign prostate and Gleason-graded malignant prostate tissue. Paraffin-embedded tissue samples were analysed by FTIR, after mounting onto a BaF(2) plate and subsequent removal of wax using Citroclear followed by acetone. Cell lines were analysed as aliquots of cell suspension held between two BaF(2) plates. It was found that the ratio of peak areas at 1030 and 1080 cm(-1), corresponding to the glycogen and phosphate vibrations respectively, suggests a potential method for the differentiation of benign from malignant cells. The use of this ratio in association with FTIR spectral imaging provides a basis for estimating areas of malignant tissue within defined regions of a specimen. Initial chemometric treatment of FTIR spectra, using the linear discriminant algorithm, demonstrates a promising method for the classification of benign and malignant tissue and the separation of Gleason-graded CaP spectra. Using the principle component analysis, this study has achieved for the first time the separation of FTIR spectra of prostate cancer cell lines derived from different metastatic sites.

Adenocarcinoma↗
PubMed1990

Systematic delineation of scan modes in multidimensional mass spectrometry.

A logical analysis of mass spectrometric scan modes is performed that reveals the full set of experiments available in multidimensional mass spectrometry. The analysis utilizes a symbolism that helps provide an organizational scheme for the representation and classification of the wide variety of experiments that exist. In general, for an n-stage experiment, there is a closed set of experimental modes producing spectral types that vary in mass dimensionality from 0 to n. There is a total of 2n experiments that have 1 or 0 mass dimensions, along with an increasing number of experiments of higher mass dimensionality. There also exists a set of 2n fundamental scan modes, viz., experiments in which only mass-to-charge ratios of individual ions, but not their interrelationships, are specified. Scans in which functional relationships between ion masses are defined (e.g., neutral loss scans) introduce complexity into the total number of scan types available in an MSn experiment, giving a total of 1, 2, 5, 15, 52, and 203 experiments of 0 through 5th order, respectively. It is shown that combinations of data from lower order experiments can be used to construct higher order spectra. Extraction of data of lower mass dimensionality from data of higher dimensionality is also demonstrated. A different method of reducing dimensionality, projection of dispersed data back into a smaller number of mass dimensions, is also introduced and characterized. The analysis reveals several new types of scan modes including an MS/MS/MS scan having unit mass dimensionality, referred to as the selective neutral-loss scan, and several new MS/MS/MS scans that are two-dimensional in mass. Examples of these new experiments are provided, and their potential value is discussed.

Mass Spectrometry↗
PubMed1985

Metabolism of testosterone by human semen.

Following the incubation of human sperm and seminal plasma with 13C2-labelled testosterone, the main metabolite, identified by gas chromatography-mass spectrometry (GC-MS), was 4-androstene-3,17-dione. In addition, 6 alpha- and 6 beta-hydroxytestosterone were identified. The more common metabolites of testosterone were not detected, and it is possible that the high substrate-tissue ratio influenced the result. Incubation of individual sperm and seminal plasma specimens with [14C]testosterone resulted in the identification, by specific activity measurements, of 4-androstene-3,17-dione in almost every specimen but with a widely varying conversion rate. Dihydrotestosterone, which on general grounds was considered a likely metabolite, could not be positively confirmed as such, although in some samples its presence was suspected. Gas chromatography-mass spectrometry was also used to identify steroids in sperm and seminal plasma extracts. Some, but not all the steroids identified as present in such extracts by other investigators, were found. During the course of this work C18 Sep-Pak cartridges were successfully used to prepare fractions suitable for SP-Sephadex and TEAP-Lipidex chromatography and subsequent analysis by GC-MS. Their use eliminated the need for purification steps otherwise necessary.

Androstenedione↗
PubMed1978

Failure to suppress adrenal function in congenital adrenal hyperplasia (21-hydroxylase deficiency). Three case reports.

Three patients, aged 14, 16, and 32 years respectively, with congenital adrenal hyperplasia (21-hydroxylase deficiency) are described. Excessive adrenal activity and ACTH secretion could not be suppressed with doses of corticosteroids sufficient to cause iatrogenic Cushing's syndrome, even though part of the steroid dosage was administered in the late evening. The resistance to feed-back suppression was of the same order as that seen in Cushing's syndrome. Adrenalectomy was performed in the 16-year-old girl, and was followed by a menarche. Adrenalectomy was considered inadvisable in the other two patients.

Adolescent↗
PubMed1976

Umbilical vein cortisol after spontaneous and induced labour and at elective Caesarean section.

Umbilical vein (UV) plasma cortisol levels were assayed at delivery after spontaneous labour, oxytocin-induced labour, prostaglandin E2-induced labour and after delivery by elective Caesarean section. Higher mean UV cortisol levels were observed after vaginal delivery than after delivery by elective Caesarean section. The highest mean UV cortisol level was observed in the PGE2 group which accords with the known ability of prostaglandins to increase steroid production. The significance of these findings is discussed.

Cesarean Section↗
PubMed1976

Relation of umbilical vein cortisol to neonatal bilirubin concentrations.

Umbilical vein cortisol levels were assayed following spontaneous labour in 30 patients. Serum bilirubin was measured in the infants born at three days after delivery. No correlation was demonstrated between third day bilirubin concentration and the cord blood cortisol. The implications of this finding are discussed.

Bilirubin↗