Quality of salivary tears following autologous submandibular gland transplantation for severe dry eye.

BACKGROUND: This study aimed to characterise the composition of the pre-ocular fluid after transplantation of the autologous submandibular gland (SMG) for patients with severe dry eye. METHODS: Stimulated and unstimulated pre-ocular fluid from 15 patients (17 eyes) with a viable SMG graft ("SMG-salivary tears"), as well as normal tears and SMG saliva (20 normal subjects/ 20 eyes), was sampled. As global tear parameters, fern pattern analysis and SDS gel electrophoresis were performed. As specific quality parameters, total protein content, secretory immunoglobulin A (SIgA), lysozyme, amylase, sodium, potassium and osmolality were measured using routine laboratory methods. The flow rate of SMG-salivary tears was determined in 5 patients by means of sequential scintillography. RESULTS: The fern pattern of SMG-salivary tears was coarse and thus more similar to normal SMG saliva than tears. SDS gel electrophoresis of the SMG-salivary tears showed albumin and two unidentified proteins in addition to the normal tear pattern. Osmolality and total protein content of SMG-salivary tears were higher than in normal SMG saliva, but still lower than in normal tears. High activities of normal tear antibacterial proteins (SIgA, lysozyme and amylase) were detected in the salivary tears. Stimulation of the secretion did not alter the composition of SMG-salivary tears. The flow rate of SMG-salivary tears was closer to that of normal tears than normal SMG saliva. CONCLUSION: Salivary tears resulting from SMG-transplantation represent condensed SMG saliva. Thus their quality is intermediate between normal tears and normal SMG saliva. High levels of secretory proteins demonstrate that the gland maintains an active function. Surgical denervation and residual tear components from the ocular surface are the most likely factors to cause the complex differences between normal SMG saliva and SMG-salivary tears. The effects of this secretion on the ocular surface are currently being evaluated in a clinical and laboratory study.

Quality of salivary tears following autologous submandibular gland transplantation for severe dry eye.

BACKGROUND: This study aimed to characterise the composition of the pre-ocular fluid after transplantation of the autologous submandibular gland (SMG) for patients with severe dry eye. METHODS: Stimulated and unstimulated pre-ocular fluid from 15 patients (17 eyes) with a viable SMG graft ("SMG-salivary tears"), as well as normal tears and SMG saliva (20 normal subjects/20 eyes), was sampled. As global tear parameters, fern pattern analysis and SDS gel electrophoresis were performed. As specific quality parameters, total protein content, secretory immunoglobulin A (SIgA), lysozyme, amylase, sodium, potassium and osmolality were measured using routine laboratory methods. The flow rate of SMG-salivary tears was determined in 5 patients by means of sequential scintillography. RESULTS: The fern pattern of SMG-salivary tears was coarse and thus more similar to normal SMG saliva than tears. SDS gel electrophoresis of the SMG-salivary tears showed albumin and two unidentified proteins in addition to the normal tear pattern. Osmolality and total protein content of SMG-salivary tears were higher than in normal SMG saliva, but still lower than in normal tears. High activities of normal tear antibacterial proteins (SIgA, lysozyme and amylase) were detected in the salivary tears. Stimulation of the secretion did not alter the composition of SMG-salivary tears. The flow rate of SMG-salivary tears was closer to that of normal tears than normal SMG saliva. CONCLUSION: Salivary tears resulting from SMG-transplantation represent condensed SMG saliva. Thus their quality is intermediate between normal tears and normal SMG saliva. High levels of secretory proteins demonstrate that the gland maintains an active function. Surgical denervation and residual tear components from the ocular surface are the most likely factors to cause the complex differences between normal SMG saliva and SMG-salivary tears. The effects of this secretion on the ocular surface are currently being evaluated in a clinical and laboratory study.

Practical implications of coexistent different technologies in clinical chemical laboratories. Solid phase chemistry and conventional analysis.

If different analytical methods are alternatively used for the determination of the same analyte, basic differences in test methodology can give rise to an increased number of deviating results. Such coexistence of methods might be necessary, for example, during a transition phase while upgrading to new technologies. We have exemplarily investigated this topic for the comparison of solid phase chemistry ("dry chemistry") versus conventional methods ("wet chemistry"). The Kodak Ektachem 700XR clinical chemistry analyser was compared with the Hitachi 737 analyser from Boehringer Mannheim using 18 clinical chemical analytes and specimens submitted for routine analysis. Before the start of the evaluation, the Ektachem 700XR was adjusted ("calibrated") by the manufacturer for optimal agreement with the Hitachi 737. Satisfactory agreement was obtained for most investigated analytes as judged by correlation coefficients and three commonly applied regression methods (linear regression, principal components, and Passing/Bablok method). For some analytes, however, strongly deviating results were often obtained. Quality control-derived limits (maximum acceptable inaccuracy) and data from biological variation (critical differences) were used for the assessment of the inter-instrument bias for diagnosis and patient monitoring, respectively. For enzymes, 0% (amylase) to 22% (creatine kinase) of all pathologic results differed by more than the maximum acceptable analytical inaccuracy (21%-27%) of these analytes. If more stringent limits derived from biological variation were used, 24% (creatine kinase)--62% (aspartate aminotransferase) of all differences between paired measurements exceeded the critical difference for enzymes. Deviations greater than the critical differences were also marked for serum concentrations of sodium, calcium, and creatinine.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the Kodak Ektachem slide assays for iron and lactate.

We evaluated the analytical performance of two clinical chemistry slides developed recently by Eastman Kodak Company for the analysis of lactate and iron with the Kodak Ektachem 700 XR analyzer. Tested with supplemented serum pool materials we found imprecisions of the lactate analysis between 0.7% and 1.3% (within-run), resp., 1.0% and 1.5% (between-run). The imprecision of the iron analysis was between 1.0% and 2.2%, resp., 1.2% and 2.7%. Linearity of the methods was proven between 0.7 mmol/L and 13.0 mmol/L (lactate analysis) and between 5.4 mumol/L and 82.4 mummol/L (iron analysis), respectively. We found no significant interferences by hemolysis, lipemia, or bilirubin. The Kodak lactate results (x) correlated well with those of enzymatic methods (y) of Boehringer Mannheim (r = 0.995; y = 1.095x - 0.128) and of DuPont (r = 0.990; y = 1.015x - 0.242). The Kodak iron analysis (x) was correlated with the FerroZine methods (y) of Boehringer Mannheim (r = 0.988; y = 0.868x + 1.111), Hoffman LaRoche (r = 0.989; y = 0.868x + 3.416). and with atomic absorption (y) (r = 0.960; y = 0.826x + 3.416). We conclude that the newly developed methods for the analysis of lactate and iron with the Kodak Ektachem analyzer are acceptable alternatives to other common methods.

On the performance and reliability of mechanized urine teststrip measurement in comparison with visual reading.

Prescreening of urine specimens by teststrips is a valuable procedure for reducing the work load of the urine analysis laboratory: positive results for leukocytes, erythrocytes (haemoglobin), protein, and/or nitrite are widely used to select pathological specimens for subsequent microscopic examination. By standardization of the measurement conditions, mechanized teststrip reading is claimed to give more reproducible results than conventional techniques. To assess their ability to improve urine prescreening, especially with regard to the comparability of the results, the practical and analytical performance of three commercially available analysers (Rapimat II/T from Behringwerke AG, Urotron RL9 from Boehringer Mannheim GmbH, and Clinitek 200 from Ames/Bayer Diagnostic) was compared with visual reading. Analytical criteria were assessed using routine urine samples, while reproducibility was tested by repeated analysis of three different commercial control urines (Kova Trol from Madaus). A mean imprecision between 3% and 11.9% was found for the mechanized dipstick reading which was comparable to that found with visual examination (4.5% with Combur9-teststrips, Boehringer Mannheim GmbH). Due to the crude classification of the results, the different analysers as well as the visual technique gave quite different distributions for each of the semiquantitative parameters in the same urine samples. Even if statistical analysis was restricted to the frequency of positive results only, significant differences (chi 2-test, p less than 0.001-0.05) between methods were obtained, but these differences could not be attributed to one method alone. Using microscopic sediment analysis as reference, pathological urines were detected with a comparable sensitivity/specificity: Urotron 0.85/0.84, Rapimat 0.91/0.67, Clinitek 0.82/0.81, and duplicate visual reading 0.88/0.67 and 0.91/0.93. Mechanized teststrip reading had no obvious advantage with respect to the time required. We conclude: (i) no improvement in analytical performance or in speed of analysis could be claimed for mechanized methods in comparison with visual reading; (ii) mechanized teststrip reading might decrease the work load of the urine laboratory if integrated into a computerized laboratory system; (iii) mechanized teststrip reading will become analytically advantageous over visual reading if a more refined classification of the results is achieved.

Determination of the specific radioactivity of amino acids by a combination of thin-layer chromatography and quantitative autoradiography.

A new method for the analysis of the specific activity of amino acids is described. The analysis is carried out by thin-layer chromatography of the dansylated amino acids, computerized fluorescence evaluation and activity measurement by quantitative autoradiography. Quantitative evaluation of the autoradiographs is achieved by careful calibration of the X-ray film blackening. As shown for 14C-labelled phenylalanine and tyrosine, the method allows the simultaneous determination of the specific activity of 22 amino acids. About 10(-13) mol of an amino acid with a specific activity of less than 5 GBq/mmol can be detected and measured by this method.