Occurrence of CCSVI in patients with MS and its relationship with iron metabolism and varicose veins.

BACKGROUND AND PURPOSE: A new treatable venous disorder, chronic cerebrospinal venous insufficiency (CCSVI), has been proposed in patients with multiple sclerosis (MS). Its relationship with iron metabolism is suggested, but has not been examined prospectively. METHODS: We performed extra- and transcranial echo colour Doppler (ECD) in 90 patients with MS and 41 healthy controls (HC). Indices of iron metabolism and the presence of peripheral signs of impaired venous flow were also examined. RESULTS: The ECD examination showed CCSVI in 8 (9%) of the 90 patients with MS and 0 HC (P = 0.11). The 8 CCSVI-positive MS patients were older (P = 0.02), had less often relapsing-remitting-MS (P = 0.02) and had more neurological disability assessed by expanded disability status scale (EDSS, P = 0.001) and longer duration of disease (P = 0.02) in comparison with the 82 CCSVI-negative MS patients. Multivariate analysis revealed that EDSS remained an independent factor associated with CCSVI (odds ratio 1.89, 95%CI 1.17-3.05, P-value = 0.009). CCSVI MS patients more often had bilateral telangiectasia at the legs (P = 0.008), reticular veins (P = 0.006) and venous stasis dermatitis (P = 0.004). No relationship was found between CCSVI and impaired iron metabolism in patients with MS. CONCLUSIONS: CCSVI is uncommon and is a secondary epiphenomenon in MS and related to more neurological disability and the presence of varicose veins at the legs.

Chylothorax or leakage of total parenteral nutrition?

The diagnosis chylothorax is based on a chemical analysis of the pleural effusion. According to the literature, this analysis can be rather straightforward, comprising measurements of triglycerides, chylomicrons, and cholesterol. In this report we present an autopsy case that alerted us to interpret these results critically. Although the laboratory tests of the pleural effusion in this patient with parenteral nutrition suggested chylothorax, additional tests (potassium (11.3 mmol.L(-1)) and glucose (128 mmol.L(-1)) proved otherwise. Comparison of the pleural effusion analysis and the content of the parenteral nutrition led to the final conclusion that the effusion was due to a leakage of parenteral nutrition instead of chylothorax. We therefore suggest adding glucose and potassium measurements to the biochemical work-up of a patient under suspicion of chylothorax.

Diagnostic value of some biochemical bone markers for the detection of bone metastases in prostate cancer.

Bone metastases in cancer of the prostate are diagnosed routinely by isotope bone scintigraphy and the measurement of alkaline phosphatase in serum and the calcium excretion in urine. The specificity of these examinations is in general not satisfactory. We therefore investigated the diagnostic value of five new markers of bone formation and bone resorption for the detection of the metastatic process. In a group of 43 patients with carcinoma of the prostate the carboxyterminal propeptide, the carboxyterminal cross-linked telopeptide, the aminoterminal cross-linked telopeptide, and the deoxypyridinoline cross-links of type 1 collagen were measured as well as the specific bone alkaline phosphatase isoenzyme. A group of 34 patients with benign prostatic hyperplasia served as a control. A receiver-operating characteristic analysis was performed. It appeared that the sensitivity of carboxyterminal cross-linked telopeptide of type I collagen was the greatest (89%), while the best specificity was obtained for the deoxypyridinoline cross-links assay (92%). The diagnostic values of the new markers were generally comparable with those of alkaline phosphatase although carboxyterminal cross-linked telopeptide of type I collagen yielded better results, but those with carboxyterminal propeptide of type I procollagen were less satisfactory. Calcium excretion in urine had no added value at all.

Serum lipoprotein-a levels and glyco-metabolic control in insulin and non-insulin dependent diabetes mellitus.

OBJECTIVES: Conflicting results for lipoprotein-a (Lp(a)) levels in diabetic patients exist in the literature. Normal, increased, and decreased values are described, and a relation to glycometabolic control is not unequivocally established. DESIGN AND METHODS: In our study Lp(a) was measured in a large group of diabetiee (80 patients with IDDM and 90 patients with NIDDM) in relation to glycometabolic control and the presence of microalbuminuria, retino and/or neuropathy. Long-term and short-term glycometabolic control were assessed by HbA1 and fructosamine assays, respectively. RESULTS: Statistically significant differences between Lp(a) levels in IDDM and NIDDM-and a control group of 110 healthy nondiabetics could not be established. It appeared that the level of Lp(a) in IDDM and NIDDM is independent of short-term and long-term glycometabolic control or the occurrence of microalbuminuria, neuro or retinopathy. However, poor glycometabolic control affected the number of Lp(a) levels elevated above a threshold of 0.25 g/L in IDDM. CONCLUSION: These results suggest that the level of Lp(a) in serum is not influenced by diabetes mellitus, glycemic control, or the occurrence of microalbuminuria, neuro or retinopathy.

Laboratory work flow analysis and introduction of a multi-functional analyser.

Laboratory work flow analysis was performed in order to define guidelines for improved laboratory organisation and efficiency. All activities were monitored from the moment a laboratory test was requested until the result was reported and received. Detailed information was collected on numbers of samples and tests, work-stations and sample splitting, number of staff and laboratory costs and management. From the data thus obtained requirements for optimal reorganisation could be developed. Reduction of work-stations appeared to be of primary importance. This could be achieved by replacement of seven different work stations by instruments for multi-functional analysis (Cobas Integra) in the department of routine clinical chemistry. Effects of reorganisation were evaluated by repeated work flow analysis. The multifunctionality of the analysers (photometry, turbidimetry, ion selective electrodes and fluorescence polarisation) provides opportunities for efficient work structuring, avoiding the need for sample splitting, distribution of sub-samples and performing analyses at different work stations. Manual and clerical errors could thus be reduced. Laboratory service to clinicians was improved by reduction of turnaround times to such an extent that all test results are reported within 60 minutes (stat service) even during peak hours. Laboratory costs were reduced by decreasing the number of laboratory staff and work-stations. Both clinicians and patients expressed great satisfaction with the effects of this reorganisation, for which work flow analysis appeared to be an indispensable instrument.

Microalbuminuria in diabetic patients: relationship to lipid, glyco-metabolic, coagulation and fibrinolysis parameters.

One hundred and sixteen insulin treated diabetic patients were evaluated for the relationship between the presence of microalbuminuria and several lipid, glyco-metabolic, coagulation and fibrinolysis factors. A significant correlation existed only between microalbuminuria and HbA1c (r = 0.23, p = 0.008) and D-dimer (r = 0.28, p = 0.002). After the subdivision of the patients in a group without (n = 85) and a group with microalbuminuria (n = 31) significant differences were found between these two groups for the HDL-cholesterol content (p less than 0.05), the HbA1c level (p less than 0.01) and for the D-dimer concentration (p less than 0.01). Comparison of the patient groups without and with microalbuminuria separately with a healthy volunteers group without albuminuria resulted in significant differences for HDL-cholesterol, triacylglycerols, HbA1c, fructosamine, fibrin monomer and D-dimer, whereas fibrinogen also was significantly different between the diabetic group without microalbuminuria and the healthy volunteers group. Several factors predisposing for atherosclerosis (decrease of HDL-cholesterol, increase of triacylglycerols, coagulation activation with relatively insufficient fibrinolysis) were noticed in both diabetic groups without or with microalbuminuria, but more pronounced in the latter group. The appliance of a Receiver Operating Characteristic (ROC) curve for HbA1c against microalbuminuria (cut-off level 20 micrograms/min) reconfirmed the value of adequate glycaemic control in diabetics for the prevention of microalbuminuria. In conclusion the results of this study show a significantly poorer glycaemic control in insulin treated diabetics with microalbuminuria than in those without microalbuminuria. The presence of lower HDL-cholesterol, higher triacylglycerols and the elevation of fibrin monomers and D-dimers is more pronounced in the microalbuminuria group.(ABSTRACT TRUNCATED AT 250 WORDS)

Glycometabolic control and fibrinolysis in diabetic patients.

We investigated 148 diabetic patients with regard to their relationship between fibrinolysis (D-dimer and plasminogen activator inhibitor; PAI) and glycometabolic control (HbA1c, HbA1 and fructosamine). The percentage of moderately controlled patients as indicated by HbA1c, HbA1 and fructosamine is relatively high (29.7, 41.7 and 30.4%, respectively). Simultaneously, the D-dimer and PAI levels turned out to be enhanced in 30.8 and 22.4% of the patients. There was a positive nonsignificant correlation between D-dimer and HbA1c, a highly significant negative correlation between D-dimer and HbA1 and a nonsignificant negative correlation between D-dimer and fructosamine. According to the upper limits of the distinct reference ranges for HbA1c, HbA1 and fructosamine, we splitted up the D-dimer results and calculated the mean D-dimer values belonging to each category. Comparing the D-dimer means for each parameter, we separately obtained significant differences of the D-dimer means between the lower and higher HbA1 and fructosamine groups, whereas in the case of HbA1c the mean D-dimer values of the categories under and over 9% showed no significant difference. For PAI, we found only weak nonsignificant positive correlations to D-dimer and fructosamine and weak but highly significant correlations to HbA1c. These results are indicative for an increase of PAI with diminished glycometabolic control as measured with the HbA1c and fructosamine level. Both D-dimer and PAI showed positive, highly significant correlations to the age of the diabetic patients, whereas HbA1c and fructosamine were age independent.(ABSTRACT TRUNCATED AT 250 WORDS)

Coagulation activation in diabetes mellitus.

One hundred and fourty-eight insulin-dependent diabetic patients were available for this study; 56 males and 92 females. For the investigation of coagulation activation we determined activated partial thromboplastin time, thrombin time, and fibrinogen besides fibrin monomers and thrombin-antithrombin III complexes (TAT-III). We assessed large percentages of increased fibrinogen levels but non-significant increases of the mean values in comparison with the reference group. The values for thrombin time were significantly prolonged, although relatively small percentages were exceeding the reference range. For the activated partial thromboplastin time, the values exceeded the upper reference limit, and the mean values were significantly higher than those of the reference group. Also for the fibrin monomers we obtained often enhanced values, and moreover, the values were significantly higher as compared with the reference subjects. The amount of TAT-III concentrations above the reference range was much smaller than for the fibrin monomers and the TAT-III levels were not significantly enhanced. The results presented here are indicative of coagulation activation in diabetics, as indicated by the fibrin monomers and more or less by the TAT-III levels. Moreover, there could be demonstrated a positive correlation between fibrin monomer levels and HbA1 concentrations.

A comparison of two methods for the determination of thallium in urine. Differential pulse anodic stripping voltammetry and flameless atomic absorption spectrophotometry.

Two analytical procedures for the determination of thallium in urine are evaluated and compared. The two methods consist of differential pulse anodic stripping voltammetry and flameless atomic absorption spectrophotometry. Both procedures correlated well and were found to be acceptable in terms of precision and analytical recovery. However, a solvent extraction step proved to be necessary for the AAS procedure, and the linearity with respect to the concentration range was rather limited. The method based on DPASV is simple, accurate, precise, and sensitive and does not require any pretreatment of the sample. We therefore recommend the voltammetric procedure for the determination of thallium in urine, as described in this paper.

Apoenzyme content of serum aminotransferases in relation to plasma pyridoxal-5'-phosphate concentration.

To investigate the considerable variation in stimulation of serum aminotransferase activities by pyridoxal-5'-phosphate added in vitro, we determined the pyridoxal-5'-phosphate content of plasma, using the tyrosine decarboxylase reaction together with the catalytic activities of alanine aminotransferase and aspartate aminotransferase, with and without pyridoxal-5'-phosphate supplementation, within a group of normal human individuals. We found a very significant inverse linear relationship between plasma pyridoxal-5'-phosphate concentration and stimulation of the activities of these enzymes in serum after supplementation with pyridoxal-5'-phosphate. We conclude that the degree of stimulation of the apoenzyme of the two serum aminotransferases clearly depends on the pyridoxal-5'-phosphate concentration in vivo.

A functioning complex of two cytochrome c fragments with deletion of the (39-58) eicosapeptide.

Two major fragments of horse heart cytochrome c involving the sequences (1-38) and (60-104) were found to produce a stable complex. The two fragments were devoid of any cytochrome c activity. The complex exhibited a hardly measurable electron transfer capacity with respect to cytochrome c oxidase and missed the 695 nm absorption band. The introduction of tryptophan in position 59 restored the intrinsic activity of the complex to the level of native cytochrome c. This was concluded from the convergence of the Eady-Hofstee plots which extrapolate to the same Vmax at high substrate concentrations. The absorption spectrum of the complex in the ferriform contained a clear absorption band at 695 nm (84% of that found with native cytochrome c). The investigation proves the indispensability of tryptophan in position 59 for the transfer of an electron to cytochrome c oxidase and supports the conclusions of Parr et al. about the existence of two consecutive processes in the folding of the two fragments (vide infra).

Synthesis, resolution and charge-donor properties of six tryptophan analogues.

In order to investigate the special function of tryptophan in peptide hormones, six tryptophan analogues have been synthesized, in which structural resemblance has been grossly retained and potentially essential properties have only partially been varied. The L-enantiomers have been isolated after enzymatic digestion of racemic dipeptide derivatives, and charge-transfer properties of the compounds have been studied.

Two structurally closely related polypeptides encoded by 14-S mRNA isolated from rat lens.

14-S mRNA from rat lens codes for two subunits of alpha-crystallin, A2 (Mr 20 000) and AIns (Mr 24 000, previously referred to as alphaX). Structural relationship between both translation products has been proved by immunoprecipitation with antisera directed against the different crystallin classes. Competition immunoprecipitation showed that the 14-S mRNA translation products are precipitated by common antibodies, specific for the A subunit of alpha-crystallin. Two-dimensional gel electrophoresis and peptide analysis provided further evidence that the 24 000-Mr polypeptide, synthesized in vitro under direction of 14-S mRNA, is identical with native alphaAIns. Although the structures of alphaA2 and alphaAIns are very similar, no precursor-product relationship exists between both 14-S-mRNA-encoded polypeptides.

Rat alpha-crystallin A chain with an insertion of 22 residues.

Rat lens alpha-crystallin contains, besides the usual alphaA and alphaB subunits, an additional minor chain. This subunit was purified by ion-exchange chromatography and its primary structure studied. It appeared to be an elongated alphaA-like chain, having an insertion of 22 residues between position 63 and 64 of an otherwise normal alphaA2 chain. Therefore this subunit was called alphaAIns, i.e. an alphaA chain with an inserted sequence. This inserted region, which contains three methionyl, five basic and no acidic residues, apparently results in an adequately functioning alphaAIns chain. The alphaAIns chain may be the product of a gene which has originated, after duplication of the alphaA gene, by insertion in one of the copies of a stretch of 66 nucleotides of unknown origin, or alternatively be the result of unusual transcription or processing of precursor mRNA (pre-mRNA), leaving an extra 66 nucleotides internally in the mRNA to be translated.

Some new bifunctional reagents for the conjugation of a protein with an amino compound in water.

Five symmetrical bifunctional reagents (I-V) have been synthesized and tested for their usefulness for the conjugation of albumin with tryptophan, in aqueous solution. With I and II about 17, with IV and V about 8 tryptophan residues could be introduced in the native protein. The difference is discussed. Reagent III has a very low solubility in water but may be useful if organic solvents are permissible.