Biomedical subjects

T Dieringer

Publications and source records attributed to T Dieringer.

6 recordsLinked to original sources

PubMed2001

Angiotensin-converting enzyme (ACE) gene polymorphisms and familial occurrence of sarcoidosis.

OBJECTIVES: The aim of this study was to test for genetic linkage and association between polymorphisms of the angiotensin-converting enzyme (ACE) gene and familial occurrence of sarcoidosis. DESIGN, SETTING AND SUBJECTS: German families with more than one member suffering from sarcoidosis were contacted and a DNA bank was established. Sixty-two families (140 patients, 77 females and 63 males, and 104 unaffected relatives) were genotyped for the ACE gene insertion/deletion (I/D) polymorphism and for two flanking variable sites (ACE A-5466C and ACE 4656(CT)2/3). As controls, 100 DNAs from unrelated resident Caucasians (50 females, 50 males) were analysed. ACE allele and genotype frequencies were determined, and parametric linkage and affected sib pair analyses and transmission disequilibrium tests were performed. RESULTS: There was a striking over-representation of the ACE I/D genotype DD in patients with sarcoidosis and their families as compared with controls of the study and well founded genotype frequencies from the literature. The same was evident for the accompanying genotypes CC and 2,2 of the flanking polymorphisms. Linkage between the segregation of ACE alleles and the disorder within families was clearly excluded for simple models of inheritance. However, there was a suggestive but not significant (P = 0.06) excess of allele sharing amongst affected siblings. There was no transmission disequilibrium for any ACE allele or haplotype. CONCLUSIONS: ACE is involved in the pathogenesis of sarcoidosis, but the ACE polymorphisms are not an inherited main cause of the disease. They are more likely to modify the development of the disorder, and the ACE I/D genotype DD might be a promoter to clinical manifestation.

Adult↗

PubMed1991

Toxoplasmosis in two cats with inflammatory intestinal disease.

Lymphocytic-plasmacytic enteritis, a chronic inflammatory intestinal disease, was diagnosed in 2 cats. In 1 cat, recurrence of clinical signs after initiating treatment was attributed to relapse of the inflammatory intestinal disease, but was found to be attributable to relapsing toxoplasmosis secondary to immunosuppressive drug therapy. Treatment with clindamycin resolved the recurrent toxoplasmosis. In the second cat, clinical signs of toxoplasmosis did not develop, but serologic testing yielded evidence of active toxoplasmosis. Treatment with clindamycin caused the titers to decrease. Relapsing toxoplasmosis may be responsible for apparent resistance to treatment in cats for inflammatory intestinal disease being treated with immunosuppressive drugs.

Animals↗

PubMed1990

[Computer-controlled analysis of the optic papilla with the Optic Nerve Head Analyzer: normal values and various age dependent papilla parameters].

The Rodenstock Optic Nerve Head Analyzer was used to study the disk parameters of 194 eyes of 122 healthy subjects. No age-related changes in the neuroretinal rim area or in the cup/disk ratio could be detected. Furthermore, no significant differences in the mean values of disk parameters were found when right eyes were compared with left eyes or when eyes of male and female subjects were compared. It was thus possible to base calculations of normal values for disk parameters on the entire sample of 194 eyes, irrespective of age and sex. It was also possible to determine the range of variation of these parameters. Statistical analysis of the data produced the following results: the smallest mean neuroretinal rim area is in the temporal disk quadrant; the largest is in the nasal disk quadrant. The mean neuroretinal rim area of the upper quadrant is almost as large as that of the lower quadrant. Consequently, the temporal quadrant has the largest cup/disk ratio, while the nasal quadrant has the smallest. The cup/disk ratios of the upper and lower quadrants are almost identical. The range of variation of all disk parameters was found to be considerable, i.e., the neuroretinal rim area of the whole disk, as well as that of each disk quadrant may be very small, not only in glaucomatous but even in normal eyes. Accordingly, the cup/disk ratio may be large even in normal eyes. Due to the broad range of interindividual variation of disk parameters, a single examination with the Optic Nerve Head Analyzer is not sufficient to distinguish normal from glaucomatous disks. Follow-up examinations are therefore required for early diagnosis of glaucoma, because the finding of a reduction in neuroretinal rim area during follow-up must be interpreted as an important sign of early glaucoma damage.

Adolescent↗

PubMed1990

[Normal values of various papillary parameters and correlation to papillary size].

The Optic Nerve Head Analyzer was used to study the disc parameters--neuroretinal rim area and cup/disc ratio--in 194 eyes of 122 healthy subjects. Both neuroretinal rim area (1.35 +/- 0.35 mm2) and cup/disc ratio (0.5 +/- 0.18) showed a large interindividual variability, i.e., very small values for the neuroretinal rim and very large values in the cup/disc ratio are not only found in glaucomatous but even in healthy eyes. Due to the great variability of disc parameters, a single examination using the Optic Nerve Head Analyzer will presumably not be sufficient to decide whether an individual disc is glaucomatous or normal. Early recognition of glaucoma by means of computerized disc analysis will therefore require follow-up examinations. In accordance with other investigators, we found a highly significant correlation between the neuroretinal rim area and the corresponding disc size (p less than 0.001), i.e., a large disc normally has a large neuroretinal rim. In addition, we also found a significant correlation between the cup/disc ratio and the corresponding disc size (p less than 0.001), i.e., even the relative value of the cup/disc ratio is not independent of disc size. A large disc normally has a large cup/disc ratio. Correlation studies between disc parameters and disc size cannot determine whether the neuroretinal rim area or the cup/disc ratio gives more information about an optic disc. Both parameters, neuroretinal rim area and cup/disc ratio, however, are of equal value concerning the recognition of glaucoma by means of computerized disc analysis, because early diagnosis of glaucoma with this new technique presupposes intraindividual follow-up examinations.

Adolescent↗

PubMed1989

Correlation between neuroretinal rim area and age in normal subjects.

The Rodenstock Optic Nerve Head Analyzer was used to study the age distribution of the neuroretinal rim area in 194 eyes of 122 normal subjects aged 7-84 years. No significant linear correlation was found between neuroretinal rim area and age. Linear regression analysis of the neuroretinal rim area in the temporal disc quadrant as a function of age led to the following equation: y = 0.00029x + 0.245; r = 0.052. Linear regression analysis of the neuroretinal rim area in the total disc as a function of age led to the following equation: y = 0.001x + 1.314; r = 0.0053. The 99% confidence limits of the regression slope ranged from -0.0025 to + 0.0045 (temporal disc quadrant) and from -0.00077 to + 0.0013 (total disc), respectively. A nonlinear correlation between neuroretinal rim area and age is very unlikely. Using the Mann-Whitney U-test, no statistically significant difference between the smallest (group of subjects aged 7-19 years) and the largest mean neuroretinal rim area (group of subjects aged 30-39 years) was detectable. From our data we conclude that there are no age-related changes in the neuroretinal rim area as measured with the Optic Nerve Head Analyzer. Changes in the neuroretinal rim area during follow-up examinations of glaucoma suspects may therefore be interpreted as an important sign of early glaucomatous damage. This confirms our previous suggestion that follow-up examinations of the optic disc structure with the Rodenstock Optic Nerve Head Analyzer are useful to confirm the diagnosis of glaucoma, even at a stage where a visual field loss cannot yet be detected by routine perimetry.

Adolescent↗

PubMedDate not supplied

Pyrethroid effects on operant responding and feeding.

The effects of permethrin, its cis and trans isomers, and deltamethrin on operant behavior and food intake were examined. Male Sprague-Dawley rats were trained to respond on a VI20 second schedule of food reinforcement. Rats were injected intraperitoneally with pyrethroids or their Emulphor vehicle 20 minutes prior to testing. Technical grade permethrin (15-60 mg/kg) produced a dose-related decrease in operant response rate. The 60 mg/kg dose decreased rates by 60%. Lower doses of cis-permethrin (30 mg/kg) and deltamethrin (2 mg/kg) also produced significant decreases in response rate. A 30 mg/kg dose of trans-permethrin was without effect. Food intake was also measured for 1.5 and 24 hour periods after tech-permethrin treatment. Food intake was decreased over both intervals by the 60 mg/kg dose. The results of these studies indicate that subconvulsive doses of pyrethroid insecticides can have significant effects on learned behavior and food intake.

Animals↗