My career has been focused in two major areas, analytical chemistry and biochemistry of complex lipids and glycoconjugates. Included here are the pioneering work on the gas chromatography of long-chain sphingolipid bases, carbohydrates, steroids and urinary organic acids. Mass spectrometry was utilized extensively in structural studies of sphingolipids, fatty acids, carbohydrates, steroids, uri...

Several markers of renal changes have been measured in a cohort of 50 workers exposed to elemental mercury (Hg) and in 50 control workers. After application of selection criteria 44 exposed and 49 control workers were retained for the final statistical analysis. Exposed workers excreted on average 22 micrograms Hg/g creatinine and their mean duration of exposure was 11 years. Three types of ren...

Urinary bladder cancer is a socially significant healthcare problem. A diverse array of aromatic and heterocyclic amines, derived from the chemical and transport industry, diet, and cigarette smoke are considered carcinogens for the bladder. To exert their carcinogenic effect and to initiate the carcinogenic response, the arylamines require a metabolic activation by the host enzymes to chemical...

A number of studies including those of Cornish and Block (1960) have measured the marked increase in serum enzyme levels following acute exposure to CC4 vapor. If it is assumed that these enzymes are being released from damaged tissue, one would anticipate that smaller molecular weight compounds, such as amino acids, would also be released. Increased urinary excretion of free amino acids or alt...

A 25-year-old man was found to have a large right adrenal mass detected by abdominal echography and computed tomography, and presented with a mild gynecomastia. Endocrine study showed increased serum concentrations and urinary excretion of estrogens and dehydroepiandorosterone sulfate (DHEA-S). The patient had no Cushingoid features but autonomous cortisol secretion, compatible with the diagnos...

The effect of nickel on cadmium nephro-toxicity and hepato-toxicity in rats was investigated. The administration of nickel (6 mg per kg, i.p., three days) or cadmium (6 mg per kg, i.m., once) significantly enhanced the urinary excretion of alkaline phosphatase (ALP), lactate dehydrogenase (LDH), glutamate oxaloacetate transaminase (GOT), amino acids, and proteins. In addition, it increased the ...

Prostacyclin is an antithrombotic hormone produced by the endothelium, whose production is dependent on cyclooxygenase (COX) enzymes of which two isoforms exist. It is widely believed that COX-2 drives prostacyclin production and that this explains the cardiovascular toxicity associated with COX-2 inhibition, yet the evidence for this relies on indirect evidence from urinary metabolites. Here w...

OBJECTIVES To assess risk factors for acquiring extended-spectrum β-lactamase-producing Gram-negative bacteria (ESBL+ GN) causing urinary tract infections (UTIs) in long-term care facilities (LTCFs). METHODS A prospective case-case-control study was carried out. In the first study, cases were defined as patients harbouring ESBL+ GN, while, in the second study, cases were defined as patients h...

Bacterial urease, particularly from Proteus mirabilis, has been implicated as a contributing factor in the formation of urinary and kidney stones, obstruction of urinary catheters, and pyelonephritis. Weekly urine specimens (n = 1,135) from 32 patients, residing at two chronic-care facilities, with urinary catheters in place for greater than or equal to 30 days yielded 5,088 phenotypically and ...

The aim of this study was to investigate whether the effects of aging on oxidative stress markers and expression of major oxidant and antioxidant enzymes associate with impairment of renal function and increases in blood pressure. To explore this, we determined age-associated changes in lipid peroxidation (urinary malondialdehyde), plasma and urinary hydrogen peroxide (H(2)O(2)) levels, as well...