Determination of urinary free cortisol by liquid chromatography‐tandem mass spectrometry

Measurement of urinary free cortisol is clinically important in the diagnosis of Cushing's syndrome. While liquid chromatography (LC) with UV detection provides much better specificity than immunologic methods, certain drugs cause interference. Detection by mass spectrometry (MS) is a potentially superior method. Our analysis utilizes 1?mL urine spiked with 6‐α‐methylprednisolone as internal standard. The samples were extracted with dichlormethane and the extract was washed, evaporated to dryness and analyzed by LC‐MS/MS operating in the negative mode after separation on a reversed‐phase C18 column. The calibration curves for analysis of urinary cortisol exhibited consistent linearity and reproducibility in the range of 10–400?nmol/L. Inter‐assay CVs were 4.0–7.6% at mean concentrations of 21–153?nmol/L. The detection limit was 1?nmol/L (signal‐to‐noise ratio=3). The mean recovery of cortisol added to urine ranged from 67% to 87% and that of the internal standard from 71% to 76%. The regression equation for the LC‐MS/MS (x) and HPLC (y) methods was: y=1.095x+8.0 (r=0.996; n=111). Drugs known to interfere with UV detection did not cause problems here. The sensitivity and specificity of the MS/MS method for urinary free cortisol offer advantages over HPLC with UV detection by eliminating drug interference. The higher equipment costs in comparison with HPLC methods using UV detection are balanced by higher throughput, thanks to shorter chromatographic run times.     

Fibronectin in synovial fluid and tissue in rheumatoid arthritis

Fibronectin is a glycoprotein found in body fluids, loose connective tissue matrix and in basement membranes. Fibronectin in rheumatoid arthritis synovial fluid was immunologically indistinguishable from the plasma form, as shown by double-diffusion analysis. Fibronectin isolated from rheumatoid synovial fluid by affinity chromatography on gelatin--Sepharose had a polypeptide pattern similar to that of plasma fibronectin in SDS--polyacrylamide gel electrophoresis. In fifty-one patients with rheumatoid arthritis and related diseases fibronectin concentrations is synovial fluid were 445 +/- 103 micrograms/ml (mean +/- SD) and within normal range, 335 +/- 52 micrograms/ml, in plasma. Immunofluorescence staining showed a prominent increase of fibronectin in the proliferating synovial connective tissue in rheumatoid arthritis as compared to normal synovial membrane. The results suggest an increased local production of fibronectin in rheumatoid synovial tissue.     

Serum CA 125 levels during the menstrual cycle

Summary. Serum concentrations of CA 125 were measured in different phases of the menstrual cycle in 16 women with ovulatory and 12 women with anovulatory cycles. CA 125 levels were significantly elevated during menstruation in both groups. In women with anovulatory cycles, but not in those with ovulatory cycles, CA 125 levels were already increased in the premenstrual phase. A negative correlation was found between serum CA 125 and progesterone concentrations in the premenstrual phase of the cycle. We suggest that premenstrual elevation of serum CA 125 in women with anovulatory cycles is related to premature endometrial vascular changes which are the result of the low serum progesterone concentration leading to insufficient endometrial control. Thus the effect of progesterone seems to be indirect rather than a direct effect on CA 125 synthesis. When the CA 125 assay is used for diagnosis of cancer, sampling should not be done immediately before or during menstruation because the physiological elevation of the CA 125 levels may give false positive results.     

Beneficial Effects of Palatable Guar and Guar Plus Fructose Diets in Diabetic Children

This randomized cross-over study evaluates the effects of extended, guar and guar + fructose diets on the metabolic balance of children with insulin-dependent diabetes mellitus (IDDM). We studied 22 children; mean age 12.2 years, mean duration of diabetes 4.4 years. The diet was supplemented for three weeks with guar in palatable form (5% of daily carbohydrate intake) and with guar + fructose (1 g of fructose/kg body weight, max 30 g/d) for another three weeks. A control group (8 children, mean age 12.3, duration of diabetes 4.3 years) followed the same experimental protocol without guar supplementation. The metabolic balance was assessed by glucosuria index (per cent of tests with less than 1% glucosuria from all urine tests) and measurements of red cell glycohaemoglobin A_1c (HbA_1c). Serum total and HDL-choiesterol, C-peptide, pancreatic and enteroglucagon were also measured. HbA_1c decreased during guar ( p <0.001) and guar + fructose diet ( p <0.001). The glucosuria index improved ( p <0.02) and the serum total cholesterol concentration decreased ( p <0.02) during the experimental guar diets. Guar in acceptable form and quantity in the diet appears to improve metabolic control of diabetic children.     

Tuberculosis of the Colon in a Kidney Transplant Patient

ABSTRACT A 58-year-old woman experienced recurrent fever episodes after kidney transplantation. She was treated with antibiotics because of suspicion of staphylococcus infection. Abdominal pain combined with haemorrhagic diarrhoea occurred eight months after transplantation. A barium enema revealed a stenotic process in the middle part of the ascending colon mimicking carcinoma, and hemicolectomy was consequently performed. Histological examination revealed tuberculosis with little granuloma formation and abundant acid-fast tubercle bacilli in the mucosa and submucosa, and only slight perigranulomatous reactions. The patient was successfully treated with triple antituberculous chemotherapy without deterioration of allograft function. Tuberculosis should be suspected in immuno-suppressed patients suffering from pyrexia of unknown origin, even when chest X-ray is normal.     

Prevalence of dental fluorosis in children taking part in an oral health programme including fluoride tablet supplements from the age of 2 years

International Journal of Paediatric Dentistry 2010; 20: 347–352 Aim. To investigate the prevalence of dental fluorosis in children who had participated in an oral health programme between the ages 2–5 years, including fluoride tablets from the age of 2 years. Design. The study group consisted of 135 10‐ to 11‐year‐old children who had participated in the programme, including parent education, tooth‐brushing instruction and prescribed fluoride tablets (0.25 mg NaF) (2–3 years: 1 tablet/day; 3–5 years: 2 tablets/day). The prevalence of dental fluorosis in the study group was compared with that in a nonintervention reference group consisting of 129 children of the same ages. The analysis was based on photos of the permanent maxillary front teeth using the Thylstrup & Fejerskov (TF) Index. Results. No statistically significant difference in prevalence of dental fluorosis was seen between the two groups. Forty‐three percent of the children in the study group and 38% in the reference group had fluorosis, the majority of a mild nature (TF‐score 1). None had a TF score above 2. The pattern was the same after correction for parent reported intake of tablets at 3 and 5 years of age. Conclusion. Introduction of fluoride tablets at the age of 2 years did not result in increased prevalence of dental fluorosis.     

Minimum analogue peptide sets (MAPS) for quantitative structure-activity relationships

The information contents in previously published peptide sets was compared with smaller sets of peptides selected according to statistical designs. It was found that minimum analogue peptide sets (MAPS) constructed by factorial or fractional factorial designs in physicochemical properties contained substantial structure-activity information. Although five to six times smaller than the originally published peptide sets the MAPS resulted in QSAR models able to predict biological activity. The QSARs derived from a MAPS of nine dipeptides, and from a set of 58 dipeptides inhibiting angiotensin converting enzyme were compared and found to be of equal strength. Furthermore, for a set of bitter tasting dipeptides it was found that an incomplete MAPS of 10 dipeptides gave just as good a model as the model based on a set of 48 dipeptides. By comparison other non-designed sets of peptides gave QSARs with poor predictive power. It was also demonstrated how MAPS centered on a lead peptide can be constructed as to specifically explore the physicochemical and biological properties in the vicinity of the lead. It was concluded that small information-rich peptide sets MAPS can be constructed on the basis of statistical designs with principal properties of amino acids as design variables.     

Influence of bacterial cell concentration and inorganic anions on lysis of Streptococcus mutans BHT by salivary lysozyme

The aim of this work was to study the influence of bacterial cell concentrations and inorganic anions on lysis of Streptococcus mutans BHT by human salivary lysozyme (HSL). HSL was partly purified from saliva by ion exchange chromatography. The bacteria were grown in a synthetic medium containing ³H-thymidine to monitor DNA release. The experiments demonstrated that release ³H-thymidine was dependent on the bacterial cell concentration and an apparent K_m-value corresponding to approximately 2.9 × 10⁸ cells/ml was calculated. The influence of I^?, Br^?, Cl^?, F^?, HCO₃^? and SCN^? on bacteriolysis was studied. All anions tested were slightly inhibitory on the action of HSL. The inhibition varied from 7 to 76% depending on the ion and ionic strength. The order of addition of HSL and sodium chloride caused different lytic responses. This was reflected by the amount of HSL adsorbed by the bacteria.