Rapid and sensitive immunomagnetic-electrochemiluminescent detection of staphyloccocal enterotoxin B.

Sensitive, rapid and reproducible detection of staphyloccocal enterotoxin B (SEB) in a range of different biological matrices was achieved using the ORIGEN((R)) Immunoassay System (Igen, Inc). The homologous immunoassay format consisted of a double antibody sandwich in which a biotinylated capture antibody, pre-bound to streptavidin-coated paramagnetic beads, was used to bind antigen from test samples. A detector antibody, labeled with ruthenium (II) tris-bipyridal chelate, was added and, when bound to the bead immunocomplex, generated light in the presence of an excess of tripropylamine. The light was detected and measured by the ORIGEN analyzer. The sensitivity of this assay was 1 pg of enterotoxin per ml of serum, urine, tissue, or buffer and was highly reproducible. Concentration curves generated from SEB standards produced consistently wide linear ranges (0.1-100 ng/ml), making quantitation possible with only two dilutions of sample (undiluted and 1:1000). The assay used 50 microl of sample per test and required a 30 min incubation period in addition to a 1 min per tube reading time (50 tubes maximum). This assay was significantly better in terms of sensitivity, linear range, and assay time than the standard microplate enzyme-linked immunosorbent assay and should permit early SEB detection in clinical samples, food, and environmental samples.

Psychological aspects of cancer surgery: surgeons' attitudes and opinions.

Fifty-one surgical consultants, registrars and senior registrars in NHS hospitals in the West Midlands (UK) were interviewed about psychological aspects of cancer surgery: information given to patients, the bad news interview, psychological risk factors in surgery, psychiatric morbidity, difficult patients, and care of the dying. Information that tended to be provided infrequently included the cause of the disease, the effects of surgery on sexual functioning, and psychological side-effects of the surgery. Surgeons most often answered incompletely patients' questions about prognosis, effects of surgery on sexual functioning, the presence of malignancy, and probable length of life. Concerning the disclosure of malignancy, 37% said they always tell the patient; 8% tell virtually all patients; 49% tell the patient depending on the patient's and relatives' wishes; and 6% tell the relatives and possibly the patient. A common strategy among 49% is to use the word 'growth' and wait for the patient to ask further. Few surgeons took even the briefest psychiatric history, and only the most severe post-operative psychological complications were referred to psychiatrists. The most difficult patients for surgeons to manage were emotionally labile, angry, demanding, controlling, refusing treatment, or predicting failure. The surgeons in this sample clearly struggled with their role as giver of bad news and with the consequent emotional reactions of the patient.

Sandwich enzyme-linked immunosorbent assay for Vibrio vulnificus hemolysin to detect V. vulnificus in environmental specimens.

Vibrio vulnificus hemolysin, purified by quantitative isoelectric focusing, was used to prepare rabbit and goat anti-hemolysin. The resulting antibodies were used as capture and detector antibody reagents in a sandwich enzyme-linked immunosorbent assay (ELISA) to detect V. vulnificus in environmental samples. By this technique, 4 laboratory-maintained V. vulnificus strains and 33 environmental V. vulnificus isolates were detected. Also, the technique distinguished five other Vibrio species from V. vulnificus, and when it was used in combination with colistin-polymyxin-cellobiose agar, 31 non-V. vulnificus isolated were excluded. This sandwich ELISA compared favorably with the current Food and Drug Administration standard immunoassay in confirming presumptive V. vulnificus colonies from environmental specimens: oysters, sediment, and seawater. Among 340 presumptive V. vulnificus colonies, the sandwich ELISA detected 95% of the confirmed V. vulnificus colonies. Equally important, the technique correctly distinguished 99% of the non-V. vulnificus colonies. The sandwich ELISA offers time-saving and labor-saving advantages over the currently accepted immunoassay.

Detection of the pesticide compound 1080 (sodium monofluoroacetate) using fluorine-19 nuclear magnetic resonance spectroscopy.

Fluorine-19 nuclear magnetic resonance (19F NMR) spectroscopic measurements were used to determine the chemical nature and amounts of organofluorine in dosed meat baits. Earlier work implied that sodium monofluoroacetate (compound 1080) in meat baits was broken down into other organofluorine compounds such as fluorocitrate. No chemical evidence was found for such compounds. Only monofluoroacetate was detected in the prepared 1080 bait samples. Once the baits have aged, aqueous extraction fails to recover all the added 1080. Analysis using 19F NMR confirmed that the 1080 present in the aqueous extracts of the bait is recovered by Kramer's liquid chromatography method. It was shown here that the aqueous extracts do not recover all the 1080 in the meat bait.

Inhibition of pancreatic carboxypeptidase A: A possible mechanism of interaction between penicillic acid and ochratoxin A.

Penicillic acid and ochratoxin A are environmentally important toxic fungal metabolites (mycotoxins) that are synergistic in combination. The effects of penicillic acid on the pancreatic enzyme, carboxypeptidase A were investigated in vitro and in vivo. A broad range of inhibition in vitro of the enzyme by PA was demonstrated with a half-maximal inhibitory concentration equal to 1.1 x 10(-4) M PA. Inhibition of carboxypeptidase A was time and temperature dependent, and resulted in decreased conversion of parent ochratoxin A to the non-toxic metabolite, ochratoxin alpha. Studies in vivo demonstrated a penicillic acid-dependent inhibition of pancreatic carboxypeptidase A activity in the mouse and the chicken following multiple oral exposure. It is postulated that the mode of toxic interaction of the two mycotoxins may be due, in part, to impaired detoxification of ochratoxin A through penicillic acid depletion of carboxypeptidase A activity.

Analgesic abuse in urological practice.

Thirty-three patients seen in a urological department had taken large doses of analgesic for prolonged periods of time. In 9 cases a diagnosis of pyramidal necrosis was established, while 4 other had pyelographic evidence of pyelonephritis, and analgesic abuse was probably an important aetiological factor in their renal condition. Analgesic nephropathy is easily overlooked unless patients are questioned routinely regarding their intake of analgesic. It is important to identify the group of patients without evidence of serious renal disease who are taking excessive quantities of analgesic and to urge them to abandon the practice.

Lysozymuria and acute disorders of renal function.

On the assumption that increased urinary lysozyme concentration (;lysozymuria') indicates tubular proteinuria and therefore impaired tubular function, urinary lysozyme has been estimated in acute disorders where transient disturbances of renal function might be expected, in cases diagnosed clinically as extrarenal uraemia, and in a few examples of acute renal disease. Reversible lysozymuria occurred with hypokalaemia, postoperative ;collapse', electrolyte depletion, severe extrarenal infection, acute pyelonephritis, the nephrotic syndrome, after a few apparently uncomplicated surgical operations, and very transiently after ventricular fibrillation abolished by DC shock. There was no lysozymuria with severe uraemic heart failure, aspirin and paracetamol poisoning, or severe jaundice, nor in two cases of acute glomerulonephritis. Although lysozymuria may occasionally be useful in the clinical diagnosis of acutely disordered renal function, the results suggest that its value is limited; on the other hand, they have provided information on renal pathophysiology in acute disease.