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Biomedical subjects

A Bayer

Publications and source records attributed to A Bayer.

At least 37 records · Page 2Linked to original sources
PubMed1999

Smoking, drinking, and other life style factors and cognitive function in men in the Caerphilly cohort.

STUDY OBJECTIVES: To examine the cognitive function in a large, ongoing cohort study of older men, and to identify associations with social and lifestyle factors. DESIGN: A cross sectional study of cognitive function was conducted within the Caerphilly Prospective Study of Heart Disease and stroke. SETTING: The Caerphilly Study was originally set up in 1979-83 when the men were 45-59 years of age. Extensive data are available on a wide range of lifestyle and other factors of possible relevance to cognitive decline. Associations between some of these and cognitive function are reported. PARTICIPANTS: A representative sample of 1870 men aged 55-69 years. MAIN RESULTS: Age, social class, medication, and mood were found to be powerful determinants of performance. Self report data on the involvement of the men in leisure pursuits were examined by factor analysis. This indicated that the more intellectual leisure pursuits are the most strongly linked with performance. A measure of social contact showed a weak positive association with the test scores. Current cigarette smokers gave lower test cognitive function scores than either men who had never smoked, or ex-smokers. There was however no evidence of any gradient in function with the total lifetime consumption of tobacco. The disparity between these two data sets suggests that there had been prior selection of men who had originally started to smoke, but more particularly selection of those who later quit smoking. There was no significant association between alcohol consumption and cognitive function, though ex-drinkers had markedly lower test scores than either current drinkers or men who had never drunk alcohol. This seemed probably to be a consequence of an high prevalence of illness among the ex-drinkers. CONCLUSIONS: Age and social class show strong associations with cognitive function. Leisure persuits and social contact are also both positively associated. Neither tobacco smoking nor the drinking of alcohol seem to be associated with cognitive function, though there is evidence suggestive of self selection of both men who had never smoked and ex-smokers.

Age Factors↗
PubMed1998

Effects of docosahexaenoic (22:6n-3), tetracosapentaenoic (24:5n-3) and tetracosahexaenoic (24:6n-3) acids on the desaturation and elongation of n-3 polyunsaturated fatty acids in trout liver microsomes.

The effects of long chain n-3 polyunsaturated fatty acids (PUFA) on the desaturation and elongation systems involved in the conversion of 18:3n-3 to 24:6n-3 were investigated. Microsomes were prepared from the livers of rainbow trout and incubated with 14C-labelled 18:3n-3 and cofactors required for elongation and/or desaturation in the presence of 22:6n-3, 24:5n-3 or 24:6n-3. The formation of 24:6n-3 was significantly inhibited in the presence of 50 microM 22:6n-3, 24:5n-3 or 24:6n-3, whereas the amount of radiolabelled 20:5n-3 formed was inhibited by only 24:5n-3 or 24:6n-3 at the same concentration. When malonyl-CoA was omitted from the incubation system to allow the measurement of desaturation in the absence of elongation, the Delta6 desaturation of 14C-18:3n-3 to 14C-18:4n-3 was inhibited by approximately 25% in the presence of 24:5n-3 or 24:6n-3 but was not affected by 22:6n-3. The Delta5 desaturation of 14C-20:4n-3 was not affected by the presence of any of the long chain PUFA and no significant effect of 18:3n-3, 22:6n-3 or 24:6n-3 on the Delta6 desaturation of 24:5n-3 to 24:6n-3 was observed. To permit the measurement of individual elongation reactions, KCN was included in the incubation medium to inhibit desaturation and 14C-labelled 18:3n-3, 18:4n-3, 20:4n-3, 20:5n-3 and 22:5n-3 were examined as substrates. 18:4n-3 and 22:5n-3 were more extensively used for elongation than 18:3n-3, 20:4n-3 and 20:5n-3. The presence of 22:6n-3, 24:5n-3 or 24:6n-3 in the incubation system had no effect on any of the specific elongations of any of the substrates examined. It is concluded that, in the conversion of 18:3n-3 to 24:6n-3 by trout liver microsomes, the Delta6 desaturation of 18:3n-3 may be subjected to direct feedback inhibition and that 24:5n-3 may be preferred over 18:3n-3 as a substrate for Delta6 desaturation.

Animals↗
PubMed1998

[Interdisciplinary longitudinal curriculum "Medical Psychology, Psychotherapy and Psychosomatics." Experiences from the preclinical segment].

The departments of Medical Psychology, Psychosomatics and Psychotherapy developed an interdisciplinary longitudinal curriculum in order to coach medical students for the whole length of their medical education. Experiences from the first four undergraduate semesters are reported. 46 students (33 females, 13 males), mean age 22.3 +/- 2.6 years, attended 60 hours of interdisciplinary group sessions. Frequent motives to join the course were interest in psychosocial disciplines and relevant previous experience. The students expected to benefit from this project in their study, their future practice as a physician, and in their personal development. Important educational goals that could be attained were the adoption of a patient-centred view in medicine as well as strengthening of the students' critical capacities and sensitivity. The students especially appreciated the possibility of group discussions and the opportunity to participate actively in the course. Based on a critical review of the evaluation, the possibility of a transfer of our model is considered and perspectives for the future are developed.

Adult↗
PubMed1997

Prevention of bacterial endocarditis. Recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

American Heart Association↗
PubMed1997

Prevention of bacterial endocarditis. Recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

Antibiotic Prophylaxis↗
PubMed1997

Prevention of bacterial endocarditis: recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

Anti-Bacterial Agents↗
PubMed1997

Prevention of bacterial endocarditis: recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the infectious Diseases Society of America, the American Academy of Pediatrics and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using root words endocarditis, bacteremia and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the U.S. Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate- and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered.

Algorithms↗
PubMed1997

Observations of diabetes care in long-term institutional settings with measures of cognitive function and dependency.

OBJECTIVE: To document the prevalence of known diabetes and quantity of diabetes care delivered in long-term institutional settings in South Glamorgan, Wales; to measure physical and mental performance of diabetic residents; and to ascertain the level of basic diabetes knowledge of both staff and diabetic residents. RESEARCH DESIGN AND METHODS: A postal questionnaire survey was sent to 31 nursing or dual registered homes and 88 residential homes in South Wales to determine the prevalence of known diabetes. Medical examination and a semistructured interview of 109 diabetic and 106 age- and sex-matched nondiabetic residents was followed by assessment of dependency (Barthel Activities of Daily Living Scale [15]; Behavioral Rating Scale [16]) and cognitive performance (Mini-Mental State Exam [12]). RESULTS: The prevalence of known diabetes was 7.2%. Forty percent of diabetic residents were taking long-acting sulfonylureas. Only half of the residents in both homes had regular blood glucose monitoring. Less than 1 in 10 diabetic residents were being followed in a hospital-based diabetic clinic. Diabetic residents had had more hospital admissions in the preceding year than nondiabetic control subjects, and their length of stay was double that of nondiabetic control subjects (P < 0.05). Health professional input was fragmented, with involvement of community nurses and dietitians being rare. Diabetic residents had significantly higher levels of arterial disease (P < 0.05), foot ulceration (P < 0.01), and dementia (P < 0.01), and more severe cognitive impairment and higher levels of dependency (P < 0.01). Knowledge of diabetes was poor among both diabetic and nondiabetic residents and care staff. CONCLUSIONS: There is an important need for a reappraisal of diabetes care in institutional settings.

Activities of Daily Living↗
PubMed1996

[Topical carbonic anhydrase inhibitors in the treatment of glaucoma].

Systemically administered carbonic anhydrase inhibitors have been in clinical use since the 1950's. Their use and side effects have been reviewed extensively. Our review summarizes the development of topically administered carbonic anhydrase inhibitors in patients with glaucoma. Moreover, it documents clinical trials leading to the present choice of dorzolamide (MK-507), which is now being reviewed for worldwide approval for marketing by 1995.

Carbonic Anhydrase Inhibitors↗
PubMed1995

Antibiotic treatment of adults with infective endocarditis due to streptococci, enterococci, staphylococci, and HACEK microorganisms. American Heart Association.

OBJECTIVE: To provide guidelines for the treatment of endocarditis in adults caused by the following microorganisms: viridans streptococci and other streptococci, enterococci, staphylococci, and fastidious gram-negative bacilli of the HACEK group. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young. EVIDENCE: Published studies of the treatment of patients with endocarditis and the collective clinical experience of this group of experts. CONSENSUS PROCESS: The recommendations were formulated during meetings of the working group and were prepared by a writing committee after the group had agreed on the specific therapeutic regimens. The consensus statement was subsequently reviewed by standing committees of the American Heart Association and by a group of experts not affiliated with the working group. CONCLUSIONS: Sufficient evidence has been published that recommendations regarding treatment of the most common microbiological causes of endocarditis (viridans streptococci, enterococci, Streptococcus bovis, staphylococci, and the HACEK organisms) are justified. There are insufficient published data to make a strong statement regarding the efficacy of specific therapeutic regimens for cases of endocarditis due to microorganisms that uncommonly cause endocarditis. As a useful aid to the practicing clinician, the writing group developed a consensus opinion regarding management of endocarditis caused by the most commonly encountered microorganisms and regarding those cases due to infrequent causes of endocarditis.

Adult↗
PubMed1995

Post-translational heterocyclic backbone modifications in the 43-peptide antibiotic microcin B17. Structure elucidation and NMR study of a 13C,15N-labelled gyrase inhibitor.

Microcin B17 (McB17), the first known gyrase inhibitor of peptidic nature, is produced by ribosomal synthesis and post-translational modification of the 69-residue precursor protein by an Escherichia coli strain. To elucidate the chemical structure of the mature 43-residue peptide antibiotic, fermentation and purification protocols were established and optimized which allowed the isolation and purification of substantial amounts of highly pure McB17 (non-labelled, 15N-labelled and 13C/15N-labelled peptide. By ultraviolet-absorption spectroscopy. HPLC-electrospray mass spectrometry and GC-mass spectrometry, amino acid analysis, protein sequencing, and, in particular, multidimensional NMR, we could demonstrate and unequivocally prove that the enzymic modification of the precursor backbone at Gly-Cys and Gly-Ser segments leads to the formation of 2-aminomethylthiazole-4-carboxylic acid and 2-aminomethyloxazole-4-carboxylic acid, respectively. In addition, two bicyclic modifications 2-(2-aminomethyloxazolyl)thiazole-4-carboxylic acid and 2-(2-aminomethylthiazolyl)oxazole-4-carboxylic acid were found that consist of directly linked thiazole and oxazole rings derived from one Gly-Ser-Cys and one Gly-Cys-Ser segment. Analogous to the thiazole and oxazole rings found in antitumor peptides of microbial and marine origin, these heteroaromatic ring systems of McB17 presumably play an important role in its gyrase-inhibiting activity, e.g. interacting with the DNA to trap the covalent protein-DNA intermediate of the breakage-reunion reaction of the gyrase.

Amino Acid Sequence↗
PubMed1995

Colonic actinomycosis: report of a case and review of the literature.

Abdominal actinomycosis is a rare entity which presents some difficulty in establishing a correct preoperative diagnosis. We report herein the case of a 41-year-old woman who developed abdominal actinomycosis involving the left colon and the surrounding retroperitoneum. The patient, who had an intrauterine contraceptive device (IUCD) in situ, presented with left flank pain and the signs and symptoms of an intraabdominal mass, which was initially diagnosed as a neoplasm originating from the left colon or the retroperitoneal space. Thus, a left colectomy was performed, but the histopathological pathological diagnosis revealed abdominal actinomycosis. We evaluated the diagnosis and treatment of this disease in light of the knowledge acquired from the available literature on this rare entity.

Actinomycosis↗
PubMed1995

[Disorders of color perception and increase glare sensitivity in phenytoin and carbamazepine therapy. Ocular side effects of anticonvulsants].

Advanced psychophysical tests, performed in 42 epileptic patients, show that the antiepileptic drugs phenytoin and carbamazepine can specifically affect the retinal function, while Valproic Acid and the epileptic seizures do not. The Farnsworth-Munsell 100-Hue and Panel D-15 désaturé tests revealed an accumulation of errors along the tritan/tetartan axis (blue colour vision deficiencies) and a high total error score. The same defect was shown by measurement of the spectral sensitivity functions. The results obtained for mesopic vision and especially glare sensitivity measured by nyktometry were markedly affected in these patients compared to a normal population. The enhanced sensitivity to glare is mainly the only one symptom complained by the patient. We propose a screening method for early detection of phenytoin- and carbamazepine-induced neurotoxicity. The literature of ocular side effects of anticonvulsant drugs is carefully reviewed.

Adolescent↗
PubMed1995

[Sensitive physiologic perceptual tests for ocular side effects of drugs exemplified by various anticonvulsants].

Advanced psychophysical tests, performed in 42 patients who have seizures, showed that the widely used antiepileptic drugs, diphenylhydantoin and carbamazepine, can specifically affect retinal function, while valproic acid and the epileptic seizures do not. The Farnsworth-Munsell 100-Hue and Panel D-15 désaturé tests revealed an accumulation of errors along the tritan/tetartan axis and a high total error score. As shown by measurement of the so-called transient tritanopia and by determination of the spectral sensitivity, this blue vision defect is not only due to loss of postreceptoral interaction between long- and short-wavelength-sensitive cones, but is also based on a disturbance in the receptor mechanism itself. The dark adaptation curve was not affected. As determined by cone flicker thresholds during dark adaptation, the inhibitory action of rods on cones is reduced. The results obtained for mesopic vision and especially glare sensitivity measured by nyktometry were markedly affected in these patients compared to the normal population. The psychophysical methods provide a very sensitive test for early detection of drug-induced retinal dysfunction and allow clear differentiation between the loss of a receptor mechanism and a defect in the neuronal interaction between photoreceptors in the human visual system induced by antiepileptics.

Adolescent↗
PubMed1994

Confirmation of association between the e4 allele of apolipoprotein E and Alzheimer's disease.

The Apo E genotype of 86 patients with Alzheimer's disease (AD) and 77 age matched controls was determined by digestion of Apo E PCR products with the restriction enzyme CfoI. The frequency of the e4 allele was significantly increased in the patient group (0.33) as compared with controls (0.12). This effect was seen in patients with a family history and in sporadic cases. The odds ratio in homozygotes for the e4 allele was 11.24 (95% confidence interval 2.45-51.50). There was no relationship between age of onset and Apo E genotype. There was no linkage disequilibrium between the apolipoprotein E locus and a TaqI polymorphism at the Apo CII locus, and no allelic association between Apo CII and AD.

Age of Onset↗
PubMed1994

Pentapeptide identified as a monoclonal antibody binding site in the serine-protease domain of t-PA.

The first defined sequential epitope of the tissue plasminogen activator (t-PA) was determined by a monoclonal antibody against a synthetic peptide segment corresponding to peptide sequence 341-354 of t-PA. This segment was selected by computer assisted epitope prediction. Balb/c mice were immunized with catalase-peptide and tripalmitoyl-S-glyceryl-cys-teinyl-seryl-peptide conjugates. A monoclonal antibody derived from this immunization was reactive with native recombinant t-PA (rt-PA) and reduced carboxymethylated recombinant t-PA (RCM rt-PA). The sequential epitope was detected by Pepscan method using overlapping octa- and nonapeptides. By fine epitope mapping with tetra-, penta-, hexa- and heptapeptides the epitope was minimized to the pentapeptide EEEQK (347-351). Replacement set analysis confirmed the importance of this amino acid sequence, especially of the amino acid E348, for antibody binding. Functional assays of rt-PA were not affected by this antibody indicating that the epitope has no influence on the enzymatic center and the binding site of the inhibitor. The analysis demonstrates that the predicted recognition site of the monoclonal antibody 17-134/11 is exposed on the surface of the native rt-PA molecule.

Amino Acid Sequence↗
PubMed1993

Impairment of retinal increment thresholds in Huntington's disease.

We have investigated detection thresholds for a foveal blue test light using a Maxwellian view system in 61 normal subjects, 19 patients with Huntington's chorea, 14 patients with Tourette's syndrome, and 20 patients with schizophrenia. Ten measurements were made: The blue test light (1 degree diameter, 500 msec duration) was presented either superimposed on a yellow adaptation field (5 degree diameter) or 500 msec after switching off this field (transient tritanopia effect). In both cases five different background intensities were presented. The only abnormality found was in patients with Huntington's chorea. During adaptation these patients' thresholds are significantly higher than normal (p < 0.005). No change was found in the transient tritanopia effect. Huntington's disease causes degeneration of several different transmitter systems in the brain. Increment threshold testing allows for noninvasive investigation of patients and confirms the involvement of the retina in the degenerative process in Huntington's chorea.

Adaptation, Ocular↗