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Biomedical subjects

A F Jones

Publications and source records attributed to A F Jones.

At least 19 recordsLinked to original sources
PubMed1995

Diagnostic value of a guaiac occult blood test and faecal alpha 1-antitrypsin.

This study evaluates the diagnostic accuracy of a faecal occult blood test and faecal alpha 1-antitrypsin in the investigation of patients with gastrointestinal symptoms or iron deficiency anaemia. One hundred and seventy nine patients with either iron deficiency anaemia (n = 67), changed bowel habit and aged > 39 years (n = 107), or a history suggestive of melaena (n = 5) provided faecal samples. After investigation, 32 patients had a diagnosis of possible gastrointestinal bleeding and 139 patients had no evidence of gastrointestinal bleeding. Eight patients had a cause of enteric protein loss in the absence of gastrointestinal bleeding and were excluded from subsequent analysis. The faecal alpha 1-antitrypsin test was diagnostically more accurate than the guaiac test in identifying probable gastrointestinal bleeding (82% and 72% respectively, p < 0.05). This faecal alpha 1-antitrypsin test was also more specific (83% and 72% respectively, p < 0.05), but was not significantly more sensitive (78% and 72% respectively). The sensitivity of these tests was insufficient to recommend their use for most patients in this study.

Adult↗
PubMed1995

Lipoprotein (a) and vascular disease: thrombogenesis and atherogenesis.

Lipoprotein (a) [Lp(a)] has been recognized for nearly 30 years, and increasingly, associated with the processes of atherogenesis and thrombogenesis. Despite this, the physiological and pathological function (and factors that influence levels) of Lp(a) remain largely unknown. Most experimental evidence supporting the mechanisms of vascular disease, thrombogenesis and atherogenesis have been generated in vitro, and to date, no in vivo confirmation exists. There is also a lack of sound evidence for Lp(a) as a risk factor in prospective as opposed to case-controlled studies. A fuller understanding of Lp(a) is still required in the molecular biology of atherogenesis and thrombogenesis.

Arteriosclerosis↗
PubMed1994

Enteric alpha-1-antitrypsin loss and comparison with Okokit II and Haemoccult for the detection of colorectal cancer.

Faecal samples from patients with symptomatic colorectal cancer (n = 19) and from control subjects (n = 54) were analysed for alpha-1-antitrypsin (A1AT) and compared with Haemoccult and Okokit II. A1AT was also measured in paired samples of normal colonic mucosa and cancer tissue (n = 16) and in media from four human colorectal cell lines (COLO 320 DM, SW620, HT29, LS 174T). Faecal A1AT concentrations were greater than controls (P < 0.0001) and detected 12 (63%) patients with cancer compared to 10 (53%) by Okokit II and 7 (37%) by Haemoccult (P > 0.05). A1AT concentrations from colonic mucosa (median, range: 0.46, 0.17-0.79 mg/g wet wt) were greater (P = 0.01) than cancer tissue (0.29, 0.13-0.74 mg/g wt wt). Adjusting for albumin, A1AT concentrations from mucosa (12.0, 3.8-32.2 mg/g albumin) remained greater (P = 0.003) than for cancer tissue (5.9, 2.4-21.4 mg/g albumin). A1AT was not detected in any of the cell-line media. The most likely mechanisms for increased faecal A1AT concentrations, apart from increased blood loss, are increased cell turnover or leakage from epithelial tight junctions. The use of faecal A1AT measurement for the detection of colorectal cancer deserves further assessment.

Aged↗
PubMed1994

Dual bezafibrate-simvastatin therapy for combined hyperlipidaemia.

Statins and fibrates are both effective in the treatment of hyperlipidaemias but are not recommended in combination because episodes of rhabdomyolysis have followed combined lovastatin-gemfibrozil therapy. We assessed treatment with dual bezafibrate-simvastatin therapy in routine clinical practice. In 22 patients, total cholesterol, LDL-cholesterol and triglycerides fell by 20.1% (P < 0.0001), 35.1% (P < 0.001) and 31% (P < 0.05) respectively, and HDL-cholesterol rose by 18.4% (P < 0.05) on combination therapy. The reduction in cholesterol followed the introduction of simvastatin, while the decrease in triglycerides followed treatment with bezafibrate. No patient developed myopathy. We conclude that dual simvastatin-bezafibrate therapy is well tolerated and may reduce triglyceride concentrations, but offers no advantage in cholesterol reduction over treatment with simvastatin alone.

Adult↗
PubMed1994

Retinol binding proteinuria and phosphaturia: markers of paracetamol-induced nephrotoxicity.

The occurrence of hypophosphataemia in paracetamol overdose suggests that nephrotoxicity is common, impaired renal tubular reabsorption of phosphate indicating renal damage. To investigate the potential nephrotoxicity of paracetamol, we studied 148 consecutive patients with paracetamol overdose. Serial clinical and biochemical measurements were made, and a fasting overnight urine collection was obtained for creatinine (Cr), phosphate and retinol-binding protein (RBP) determination. Renal threshold phosphate concentration (TmPO4/GFR) was determined from urinary parameters by an established nomogram. The degree of hypophosphataemia correlated with the severity of overdose, and with TmPO4/GFR. The median RBP/Cr ratio was higher in those patients exhibiting biochemical hepatotoxicity compared with those without hepatotoxicity, in whom median RBP/Cr was not significantly higher than controls. Within the group of patients showing biochemical hepatotoxicity, there was a correlation between log RBP/Cr and TmPO4/GFR. RBP/Cr ratio is a less sensitive marker of renal tubular toxicity than phosphaturia in these patients, and may indicate a different mechanism of toxicity.

Acetaminophen↗
PubMed1992

Role of reactive oxygen species in the generation of fluorescence by glycation.

Fluorescence (excitation 360 nm, emission 454 nm) generation in glycated albumin was investigated. Antioxidants and the metal chelator desferrioxamine (DFX) were used to study the mechanism of fluorescence generation. Delipidation studies, reverse phase chromatography and scanning fluorimetry were performed to examine the nature of this fluorescence. The mechanism of action of aminoguanidine, a compound which has been shown to inhibit the formation of visible fluorescence in proteins in vitro and in vivo was investigated in relation to glycation and by comparison with compounds with structural similarities. We conclude that hydrogen peroxide, metal ions and hydroxyl radicals are involved in fluorescence generation in glycated albumin, which is largely lipid in nature, and arises through glycation, amino acid oxidation and changes in bound lipid. Our results suggest that the action of aminoguanidine is not specifically related to blocking of ketoamine groups on glycated proteins as previously suggested.

Albumins↗
PubMed1992

Transvaginal ultrasonography.

Transvaginal ultrasonography has provided new anatomic and pathophysiologic information about the female pelvis. Because of probe proximity to the organ of interest and higher insonating frequency, resolution is dramatically improved. Problems previously encountered during transabdominal scanning, such as obesity, bowel gas, and a retroverted uterus, no longer preclude accurate diagnosis. Patient acceptance is nearly universal. Physiologic information concerning the endometrium and ovarian follicles has improved infertility diagnosis and treatment. Hormonal and vascular Doppler changes can be correlated with cyclic endometrial patterns and follicle size. Oocyte retrieval, management of pre-existing inflammatory disease, and treatment of complications of pregnancy are easier and safer with a transvaginal approach. Uterine malformations, leiomyomas, and cancers are more easily detected in premenopausal and postmenopausal women. The documentation of early intrauterine or ectopic pregnancy has decreased maternal morbidity and mortality. Tube-sparing procedures with preservation of reproductive potential are now more commonly employed due to earlier recognition of unruptured tubal pregnancy. Interventional TVS has led to improved recognition and treatment of pelvic cysts and abscesses and multiple pregnancy. Chorionic villous sampling can be performed more easily without the need for anesthesia, with adequate tissue obtained.

Female↗