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Biomedical subjects

S Kraus

Publications and source records attributed to S Kraus.

At least 19 recordsLinked to original sources
PubMed1995

Stereotypes and ethnocentrism: diverging interethnic perceptions of African American and white American youth.

Much recent work on stereotyping has dealt with groups that are either artificially created or that do not have an extensive history of conflict. The authors attempted to overcome this limitation by examining issues of perceived variability and ethnocentrism among samples of White American and African American youth. The goals were both to examine theoretical issues in stereotyping and to describe the current state of ethnic interrelations among young people. Four studies are reported. Throughout, the samples of African Americans demonstrate interethnic judgments that are consistent with existing work on stereotyping and ethnocentrism. White American students, however, reported judgements that replicate neither the out-group homogeneity effect nor ethnocentrism. Alternative explanations for this difference are considered, and the discussion focuses on differing views concerning the role of ethnic identity and diversity in our society.

Adolescent↗
PubMed1995

[Photo- and videographic determination of the dilatation deficit in differential diagnosis of Horner syndrome].

Physiological anisocoria, a very frequent condition among normal subjects, must be differentiated from Horner's syndrome. Aside from a history including evaluation of older photographs, pharmacological pupil testing with cocaine eye drops has been the "gold standard". Measurement of dilation lag, occurring in Horner's syndrome, is much less common and normal values are missing. Therefore, we evaluated various photographic parameters for testing for the best parameter to discriminate Horner's syndrome (22 patients) from physiological anisocoria (16 patients). Additionally, we tested whether a commercially available camcorder is sufficient to record pupillary dilatation lag. An anisocoria of 0.6 mm or more 4s after switching off the illumination discriminates physiological anisocoria from Horner's syndrome with a sensitivity of 82% and a specificity of 69%. A dilatation speed of 1.1 mm/4 s shows the same ability to differentiate in anisocoria and does not provide any better results. Because of the good correlation between post-cocaine anisocoria and anisocoria after 4 s in darkness, photographic or videographic measurements of the pupillary dilatation lag may complete or in some cases even replace cocaine testing.

Adolescent↗
PubMed1995

[Photographic pupil diagnosis in Horner syndrome].

In cases of miosis without other clinical signs and not contributory medical history it is often hard to differentiate Horner's syndrome. In these cases the pharmacological testing with cocaine eye drops is a well established and validated method. The physiological testing, i.e. the detection and measurement of a dilatation lag in Horner's syndrome, is not so common. For this reason we measured the dilatation of pupils in 22 Horner's syndromes and 16 physiological anisocorias to find limit ("cut off") values. We used flash photography and a commercial available camcorder and took photos in bright light (400 cd/m2) as well as 4 and 15 seconds after cessation of light stimulus in darkness. An anisocoria after 4 seconds of darkness greater than 0.6 mm distinguishes both groups with a sensitivity of 82% and a specifity of 69%. A dilatation speed of the smaller pupil during the first 4 seconds of darkness lower than 1.1 mm/4 sec is also a good threshold value. Because of the additional good correlation of these parameters to the anisocoria after cocaine the photographic methods are at least a supplement to pharmacological testing with cocaine, which is sometimes equivocal and always delays the localizing hydroxyamphetamine test. The advantage of using a camcorder is the immediate evaluation on a TV screen. Because of the similar price it is more useful to buy an infrared camera to perform real pupillography. Because of the missing possibility of magnification we prefer the evaluation of slides instead of Polaroid flash photographs.

Adolescent↗
PubMed1994

[Prenatal eyelid development in the hl-mouse--a hairless mutant of the colored wild mouse].

BACKGROUND: A decisive condition for the clarification of malformations and degenerations is knowledge of the pre- and postnatal development. Therefore investigations were undertaken to determine the plan and lay-out of the eye-lids in an hairloss mutant of mouse. MATERIALS AND METHODS: Biomicroscopical and histological investigations were carried out in 51 hl-mice from the 10th day of gestation unto the birth. This particular mouse is a spontaneous hairloss mutant, in which corneal degenerations also occur. RESULTS: On the 11th day of gestation the ectodermal dips may be distinguished, as well as the shoe-lace-like furrows around the eye-ball, which indicate the development of the eyelids. The upper and lower lid are formed by proliferation. The fusion of the eyelids is completed around the 16th day of gestation. DISCUSSION: The eyelid development starts in mice between the 11th and 14th day of gestation. The fusion is completed on day 15-17. The morphogenesis of the eyelid development will be discussed.

Animals↗
PubMed1992

Domain structure of human 72-kDa gelatinase/type IV collagenase. Characterization of proteolytic activity and identification of the tissue inhibitor of metalloproteinase-2 (TIMP-2) binding regions.

The 72-kDa gelatinase/type IV collagenase, a metalloproteinase thought to play a role in metastasis and in angiogenesis, forms a noncovalent stoichiometric complex with the tissue inhibitor of metalloproteinase-2 (TIMP-2), a potent inhibitor of enzyme activity. To define the regions of the 72-kDa gelatinase responsible for TIMP-2 binding, a series of NH2- and COOH-terminal deletions of the enzyme were constructed using the polymerase chain reaction technique. The full-length and the truncated enzymes were expressed in a recombinant vaccinia virus mammalian cell expression system (Vac/T7). Two truncated enzymes ending at residues 425 (delta 426-631) and 454 (delta 455-631) were purified. Like the full-length recombinant 72-kDa gelatinase, both COOH-terminally truncated enzymes were activated with organomercurial and digested gelatin and native collagen type IV. In contrast to the full-length enzyme, delta 426-631 and delta 455-631 enzymes were less sensitive to TIMP-2 inhibition requiring 10 mol of TIMP-2/mol of enzyme to achieve maximal inhibition of enzymatic activity. The activated but not the latent forms of the delta 426-631 and delta 455-631 proteins formed a complex with TIMP-2 only when excess molar concentrations of inhibitor were used. We also expressed the 205-amino acid COOH-terminal fragment, delta 1-426, and found that it binds TIMP-2. In addition, a truncated version of the 72-kDa gelatinase lacking the NH2-terminal 78 amino acids (delta 1-78) of the proenzyme retained the ability to bind TIMP-2. These studies demonstrate that 72-kDa gelatinases lacking the COOH-terminal domain retain full enzymatic activity but acquire a reduced sensitivity to TIMP-2 inhibition. These data suggest that both the active site and the COOH-terminal tail of the 72-kDa gelatinase independently and cooperatively participate in TIMP-2 binding.

Base Sequence↗
PubMed1992

Evidence that estrogens modulate activity and increase the number of 1,25-dihydroxyvitamin D receptors in osteoblast-like cells (ROS 17/2.8).

A detailed understanding of the mechanism of action of estrogen on bones is still lacking. The present study was designed to examine possible modulation by 17 beta-estradiol (E2) on the effects of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] and on vitamin D receptors (VDR) in the ROS 17/2.8 osteoblast-like cell line. Cells were grown in phenol-red free medium supplemented with charcoal-stripped fetal calf serum (FCS). Total cellular VDR were measured in cell homogenates after extraction with a KCl hypertonic buffer. VDR-binding capacity doubled in the presence of 10 nM E2 (16.2 +/- 2.3 vs. 7.0 +/- 1.3 fmol/mg protein, respectively; P less than 0.01), while the Kd for 1,25-(OH)2D3 did not change (approximately 0.1 nM). Tamoxifen alone had no effect on VDR, while it completely abolished the E2-induced increase in VDR, indicating that the effect was specific for E2 and estrogen receptor mediated. 1,25-(OH)2D3 inhibited cell proliferation, determined by [3H] thymidine incorporation to DNA, in a dose-dependent fashion between 0.01-100 nM. The inhibitory effect of 1,25-(OH)2D3 on cell proliferation was significantly augmented in the presence of E2 (10 nM). 1,25-(OH)2D3 increased osteocalcin secretion to the medium by the cells in a dose-dependent fashion between 0.01-100 nM. In the presence of E2 (10 nM), maximal osteocalcin secretion in response to 1,25-(OH)2D3 was 3.5-fold higher than that in response to 1,25-(OH)2D3 alone. These results indicate that E2 modulates 1,25-(OH)2D3 activity in osteoblast-like cells, and that this effect can be attributed to an increase in VDR.

Animals↗
PubMed1992

Multiple occurrence of macro creatine kinase in one family.

We measured creatine kinase (CK, EC 2.7.3.2), CK-MB isoenzyme activity and mass concentration, and distribution of CK isoenzymes (by electrophoresis) in serum from five members of one family. The mother and two young children showed CK-IgG complexes in their sera. The concentration of the CK-IgG complexes in the children decreased over time, suggesting that the complex involved maternal IgG and had been transferred across the placenta from the mother to her children.

Adult↗
PubMed1989

The influence of cephalostatic ear rods on the positions of the head and neck during postural recordings.

This study examined the effect of cephalostatic ear rods on the positions of the head and neck. The method error was assessed for postural recordings of the head and neck position made with and without ear rods. A photographic angle was correlated with the postural angles on x-ray film. The material compared 33 dental students who were recorded with ear rods in and with ear rods out. Subjects were chosen randomly to repeat the postural recordings. The differences between the mean for each postural variable were subjected to comparative analysis, using Student's t test for paired samples. A significant difference (p less than or equal to 0.05) was found between the means of the inclination of the cervical spine to the true horizontal and the means of the photographic angle. The mean values for the remaining postural variables showed an insignificant but consistent pattern of axial extension of the cervical spine. Cephalostatic ear rods may alter head and neck position during postural recordings. The method error made for recording total head and neck position with ear rods was higher than without ear rods. The difference in the photographic angle was found to have a moderate positive correlation with the difference in the cervical inclination and the total head and neck position. These data suggest that lateral cephalostatics without ear rods may be used to record total head and neck position and the photographic technique may be used as a quick, inexpensive method for the clinician to determine head and neck positional changes before and after treatment.

Adult↗
PubMed1988

Racial trends in syphilis among men with same-sex partners in Atlanta, Georgia.

Early syphilis cases attributable to homosexual transmission declined in DeKalb County, Georgia, from 191 in 1981 to 97 in 1985. This decline occurred only among White men with same sex partners (SSP); early syphilis among Black men with same sex partners has risen. This pattern is consistent with the hypothesis that changes in sexual behavior instituted by White men at risk of acquiring HTLV-III/LAV infection may have resulted in decreased incidence of early syphilis among those men.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Relationship of head posture and the rest position of the mandible.

Eight subjects were evaluated to assess the relationship between VDR and head posture. Photographic evaluation of head position and VDR was performed initially to quantify a baseline recording. All subjects were then given 4 weeks of physical therapy to improve head posture. Photographs were remade after 2 and 4 weeks of therapy. An increase in the VDR and in the angle of the head to the cervical vertebra was noted in all patients. Although further study is indicated to confirm the findings of this pilot study, it appears that the VDR is influenced by head position. This finding should be considered when prosthodontic problems are treated.

Adult↗
PubMed1980

Current concepts in mental retardation.

Increased concern for the rights of the handicapped has led to changes in the philosophy of treatment for the mentally retarded. Normalization means that the retarded child has the right to live in an environment that most encourages normalized behavior. This concept is often in opposition to institutionalization. The doctrine of least restrictive alternative requires treatment strategies that minimize the degree of infringement on patients' rights without jeopardizing the likelihood of positive outcomes.

Attitude of Health Personnel↗