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Biomedical subjects

A Hesse

Publications and source records attributed to A Hesse.

At least 109 records · Page 6Linked to original sources

Analysis of urinary stones by computerized infrared spectroscopy.

The computerized assessment of infrared spectra of urinary stones with existing programmes such as SEARCH (Lehmann, C. A. et al. (1988) Clin. Chim. Acta 173, 107-116), TWIN or CIRCOM (Hesse, A. et al. (1988) Fresenius Z. Anal. Chem. 330, 372-373) has proved to be unreliable when used for routine urinary stone analysis. A more refined method has to be used in place of simple comparison algorithms. STONES is a new programme for computerized analysis of urinary stones developed with the intention of simulating the former non-computerized analysis procedure. STONES is a rule-based system, which interprets the infrared spectra qualitatively by its rules. A quantitative result is obtained by means of library search. Combining these two methods 93% of the tests were correct with regard to clinical relevance.

Evaluation Studies as Topic↗

2,8-Dihydroxyadeninuria: laboratory diagnosis and therapy control.

This report is concerned with the experience gained with two 2,8-dihydroxyadenine (2,8-DHA) stone patients. When adenine phosphoribosyltransferase (APRT) deficiency is suspected, the risk of stone formation can be detected at an early stage from the crystalline urinary sediment. Infrared spectroscopic analysis of the crystals or of a urinary stone, if present, will confirm the diagnosis. Determination of the APRT activity will facilitate quantification of the enzyme deficiency and elucidation of the hereditary history. 2,8-DHA excretion in the 24-hour urine and its circadian rhythm were determined at 3-hour intervals using a new method of high performance liquid chromatography determination. This method also provides a means of monitoring the effectiveness of allopurinol therapy.

Adenine↗

[Effect of an allopurinol/benzbromaron preparation on the composition of urine in a circadian course].

In 13 patients suffering from recurrent calcium-oxalate urolithiasis the circadian course in the excretion of urinary components was investigated before and during treatment with a combination of allopurinol and benzbromarone. The patients were given a diet standardized in food and liquid intake. Urine was collected for 3 days every 3 h from the 7th day of standard diet. On days 8 and 9 each patient received one tablet of the combination. On all 3 days of urine collection a constant circadian course of urine volume was observed; pH values also showed a nearly identical course on all 3 days with increased daytime and low night values. Maximum excretion of uric acid under dietary conditions was discovered between 11 a.m. and 5 p.m. (day 7). After the first application of the compound (day 8, 8 a.m.) a transient increase in uric acid excretion was observed in the third collection period (2-5 p.m.), followed by a sharp decrease. Following the second application (day 9) the transient increase of the uric acid excretion was clearly diminished. Uric acid excretion in the 24-h urine also decreased steadily from 3.46 mmol/day (control) to 3.25 and 3.06 mmol/day (treatment). Serum uric acid decreased significantly from 324.5 to 275.6 mumol/l. After the first application of the compound (day 8) moderate changes of the urinary components - oxalic acid, Na, K, and chloride - significant changes of Ca were observed, whereas after the second application of the compound (day 9) the values no longer differed from control values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Experimental determination of the kinetics of calcium-binding with chondroitin sulphate and the effects of uric acid on this process.

The calcium-binding kinetics of chondroitin sulphate C (CS) have been determined using equilibrium analysis including 45Ca. There is a linear relationship between the extent of the Ca binding and the concentration of CS present. 1 mumol CS disaccharide unit binds 0.757 mumol Ca. Scatchard plots of the data have revealed a single constant of dissociation (KD = 0.1429). In the presence of urate ions, and dependent on the pH value, the ability of CS to bind Ca may be impaired by as much as 31%. These measurements have supported the theory that urate ions interact with the GAGs in urine.

Calcium↗

T-cell prolymphocytic leukemia (T-PLL) with unique surface phenotype.

Leukemic cells of a 19 year old patient with prolymphocytic leukemia of T-cell type (T-PLL) were characterized by surface markers and immunologic functions. Phenotypic analysis using a large panel of monoclonal antibodies corresponding to the clusters (CD) of differentiation antigens established on the Leukocyte Typing Workshops I and II revealed a unique T-cell phenotype not yet reported in the literature: CD1 (T6)-, CD2 (T11)+, CD3 (T3)+, CD4 (T4)-, CD5 (T1)-, CD6 (T411)+, CD7 (Leu9)+, CD8 (T811)-, CD10 (J5)-, CD11 (M22)+, CD12 (M67)-, CD13 (My7)-, CD14 (Mo2)-, CD16 (Vep13, 3G8, Leu11)+, CD18 (MHM23)+, CD19 (B4)-, CD20 (B1)-, CD25 (TAC)-, MHC-class II (HLA-DR, HLA-DQ)-, NKH1A+, Leu7-. Despite the expression of surface structures associated with natural killer (NK) function (CD16, CD18, NKH 1 A) the T-PLL cells were inactive in NK assays in vitro. Low in vitro ADCC activity was detectable. This unusual T-PLL phenotype might help to identify a new distinct T-cell differentiation stage.

Adult↗

Measurement of urinary oxalate: an enzymatic and an ion chromatographic method compared.

An ion chromatographic and an enzymatic method for determination of oxalic acid in urine were compared on the basis of reliability and practicability. Both methods displayed a within-run imprecision of under 5% and a total imprecision of under 10%. The mean recovery of 0.2 mmol/l sodium oxalate lay close to 100% for both methods. After 80 parallel determinations, both methods produced statistically identical results. In terms of cost per analysis, ion chromatography is the method currently preferred when large numbers of samples are involved. If only a few samples are to be analysed the enzymatic method--without any loss of reliability--can be employed.

Carboxy-Lyases↗

Dependence of urine composition on the age and sex of healthy subjects.

The lithogenic and inhibitory substances in the 24-h urine of 150 healthy females and 150 healthy males were recorded. These two groups were further subdivided into 6 different age-groups, with 25 in each group. The 24-h excretion in these various age-groups displayed considerable differences in some cases, particularly in the case of the pH value, and the Ca, Mg, citrate and phosphate excretion of the women, and the Ca, Mg, uric acid, Na and K excretion of the men. All the parameters measured with respect to the males displayed higher levels of excretion than those of the females.

Adolescent↗

[Clinical aspects and prognosis of highly malignant non-Hodgkin's lymphomas].

Clinical data and courses of the disease of 56 patients with non-Hodgkin-lymphomas of high malignancy were demonstrated. The age-depending summit of the frequency was between the 51st and 60th year of age, the age median was about 48 years. The initial remission rate three months after the beginning of the therapy was 66%. Out of the responders in 44% relapsed, in which cases 70% of the relapses developed in the first year after the beginning of treatment. After twelve months the survival rate was 0.52 and after 48 months 0.32. Patients with initial remission, with localized stages I and II (Ann Arbor) as well as with primarily extranodal manifestation and with histology of centroblastoma had a clear prognostic advantage. Initial B-symptomas, an advanced stage of the disease and a histology of immunoblastoma and lymphoblastoma as well were negatively correlated to the prognosis.

Adolescent↗

Loading tests for diagnosis of metabolic anomalies in urinary stone formers.

Four per cent of the population in the industrialized countries of Europe suffer once or several times from urinary calculus in the course of their lives. The high number of recurrences (50 to 60%) necessitates specific prophylaxis. Depending on the precise stone composition, a specific metabolic investigation should be undertaken in cases with recurrent urinary calculus. Within a special laboratory diagnostic program, all major anomalies can be diagnosed by means of loading tests. With the ammonium chloride loading test, renal tubular acidosis is diagnosed; the calcium loading test differentiates the types of hypercalciuria and the purine loading test verifies "latent hyperuricaemia".

Acidosis, Renal Tubular↗

Searching for neural correlates of the hearing sensation fluctuation strength in the auditory cortex of squirrel monkeys.

Sounds with slow (less than 20 Hz) fluctuations may elicit the hearing sensation fluctuation strength. For AM tones, neural correlates of fluctuation strength were searched in the auditory cortex of unanesthetized squirrel monkeys. To enable a comparison of psychophysical and physiological data, the 'modulation' of the peristimulus time histogram was fitted by a sinusoidal function. The dependence of the amplitude of this function on modulation frequency, modulation depth and sound pressure level was often comparable to the dependence of fluctuation strength on the same stimulus parameters. In particular, as a function of modulation frequency, the neural data also show a bandpass characteristic at low modulation frequencies as was found for the hearing sensation fluctuation strength.

Animals↗

The excretion of glycosaminoglycans in the urine of calcium-oxalate-stone patients and healthy persons.

A method for the routine determination of glycosaminoglycans (GAGs) in urine has been optimized and is described here in detail. In 24-hour urine, males excrete significantly more GAGs than females. GAG excretion increases with advancing age. No significant difference exists between GAG excretion in healthy persons and in Ca-oxalate-stone patients. GAG excretion is diet-dependent and declines under conditions of balanced standardized diet. Evidence was obtained to show that GAG excretion follows a circadian rhythm with maximum during the day and minimum during the night. Both stone patients and healthy persons with hyperuricosuria show an increased GAG excretion.

Adult↗

Analysis of canine urinary stones using infrared spectroscopy and scanning electron microscopy.

Infrared spectroscopic analysis of 741 canine urinary calculi revealed that struvite stones, 58% of the total, were the ones most commonly to be found. Cystine stone disease, 21%, is also of great significance for dogs, whereas calcium oxalate, urate and brushite calculi occur only seldom. 3 cases of xanthine stone formation were also noted. SEM examination revealed structures similar to human stones such as bipyramidal weddellite, pseudomorphs from whewellite to weddellite, apatite deposits in cystine stones and characteristic mono-ammonium-urate needles. Other, unknown, structures were also discovered such as closely-knit intergrowths of cystine and brushite strata, mono-Na-urate and mono-K-urate intergrowths and Ca-urate. Of particular interest are the various forms of xanthine from compact spherical to lance-shapes in sheath-like arrangement.

Animals↗

Experimental investigation of the genesis of struvite stones in cats.

Infrared spectroscopy of feline urinary stones revealed that struvite was the main constituent in 77.6% of all concrements. However, only in 30.8% (16/52) of struvite stone patients were any infections of the urinary tract detected. Scanning electron microscopical comparison of non-infected feline struvite stones and human struvite concrements which had grown in the presence of infection revealed clear differences. All the feline struvite concrements were of coarse crystalline construction with the crystalline form typical of struvite. Traces of partial solution and stratification were frequently detected on the crystalline surfaces. The human struvite stones whose growth had been accompanied by infection did not display these features; the predominant structures in these concrements revealed very little evidence of any ordered growth. Examination of the urine and calculation of the relative supersaturation showed that where physiological pH values and physiological concentrations of lithogenic substances were present sterile urine can become supersaturated with struvite. The morphological peculiarities of the feline concrements and the results of urinary analysis indicate slow crystalline growth rates. Phases of growth alternate with periods of stagnation. This process may be influenced by dietary factors. In contrast to this, struvite stone formation in the presence of infection is characterised by rapid growth in continually supersaturated urine.

Animals↗