Event-related potentials in HIV infection: evidence for impact of antiretroviral treatment.
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Adult↗
Biomedical subjects
B Bauer
Publications and source records attributed to B Bauer.
Cataract patients in a defined Swedish population, 1986 to 1990. V. Postoperative retinal detachments.
OBJECTIVE: To estimate the risk of retinal detachment after cataract surgery. DESIGN: Prospective study from December 17, 1985, through December 31, 1992 of all cataract surgeries performed in a single referral region of the Lund (Sweden) Health Care District from December 17, 1985, through December 31, 1990. SETTING: The University Hospital of Lund. PATIENTS: Data were collected on 5878 consecutive cataract operations. The study population was complete enough to represent all cataract surgery in the referral region during this period. RESULTS: Two years after cataract surgery, the risk of retinal detachment was 0.18%. The follow-up period after cataract surgery in this study was up to 7 years, with a mean of 50.7 months (>4 years), and the total risk of retinal detachment or detachment-related conditions was 0.71%, all cases included. The relative risk of detachment was 4.9 after YAG laser capsulotomy. It changed by a factor of 1.3 with an increase in the axial length of 1 mm and by 0.94 for each added year of patient age. CONCLUSION: A young patient with axial myopia operated on because of cataract and postoperatively treated with YAG laser capsulotomy runs an important increased risk of developing retinal detachment.
Adolescent↗
MRI-guided flumazenil- and FDG-PET in temporal lobe epilepsy.
In temporal lobe epilepsy (TLE) patients without lesions, major hippocampal sclerosis, or atrophy on magnetic resonance imaging (MRI), the localizing power of [11C]flumazenil (FMZ) and 2-[18F]fluoro-2-deoxy-D-glucose (FDG) was compared using high-resolution positron emission tomography (PET) studies and individually coregistered MRI scans. Following complete clinical, neuropsychological, and electrophysiological evaluation, benzodiazepine receptor density was assessed using the FMZ equilibrium method. Thirty minutes later, interictal FDG-PET was performed under resting conditions. PET images were matched to three-dimensionally coregistered, T1-weighted MRI. Each temporal lobe (TL) was divided into 12 volumes of interest. The regional FMZ data were normalized with respect to average cortical values. For each patient the right-left asymmetries of rCMRGlc and normalized FMZ data were calculated. In 7 to 10 patients, mesial TL structures showed reduced FMZ binding, with a decrease by at least 10% in the affected TL. Reductions of 10% or more of rCMRGlc usually were more widespread than FMZ reductions and often involved lateral temporal cortex. The regions of most pronounced disturbances are not necessarily identical in both methods. Three patients had a complex correspondence of lateralization with PET, neuropsychological, and EEG data. In 4 patients, lateralization was less clear from EEG or neuropsychological results but was still consistent with lateralization by PET. In 3 of 10 patients, however, major discrepancies were found. These data suggest that the combination of neuropsychological testing, EEG, and MRI-guided FMZ- and FDG-PET will help to select patients with clearly defined epileptogenic foci especially in mesial TLE. Even in cases without MRI lesions, TL epileptic foci can be lateralized with consistency across the methods; FMZ-PET shows the pathologic focus more circumscribed than FDG-PET.
Adult↗
Glucose consumption and methionine uptake in low-grade gliomas after iodine-125 brachytherapy.
We investigated whether 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) and carbon-11 methionine are suitable tracers to monitor the effects of therapy for low-grade gliomas. Ten patients with low-grade glioma without previous treatment were studied with FDG positron emission tomography. Additionally, l-[methyl-11C]methionine uptake was measured in five subjects before and 1 year after computerized tomography (CT)-guided stereotactic and computer-assisted implantation of iodine-125 seeds. All scans were 3D-matched to CT, isodose volumes were determined, and changes in glucose metabolism and methionine uptake were evaluated in tumour and brain tissue as a function of radiation dose. After 1 year glucose metabolism was not significantly altered up to a radiation dose of 300 Gy, whereas methionine uptake showed a significant dose-dependent decrease. Higher rates of decline were found in tumours with high basal methionine incorporation activity before therapy. These data suggest that measurement of methionine uptake is more suitable than measurement of FDG uptake for monitoring therapeutic effects in low-grade gliomas.
Adult↗
Tributyltin biomonitoring using prosobranchs as sentinel organisms.
Tributyltin (TBT) compounds, some of the most toxic xenobiotics, produce a variety of pathological reactions in animals. A reliable biomonitoring method to assess the degree of environmental TBT pollution has been described based on investigations of virilization phenomena in prosobranch snails (Mollusca: Gastropoda). Examples are the imposex phenomenon in marine and freshwater species, the intersex reaction in littorinids and the reduction of female sexual glands and offspring numbers in further species resulting mainly in a sterilization of females. The degree of imposex or intersex in populations is determined by different biomonitoring indices which allow to assess the TBT pollution of the environment at low costs with high precision. The effectiveness of TBT legislations is analysed by extensive surveys in France and Ireland indicating that there is still a continuing threat to sensitive marine organisms. TBT disturbs the biosynthesis of steroid hormones on the level of estrogen biosynthesis. The observed virilization phenomena seem due to an inhibition of the cytochrome P-450 dependent aromatase by this organotin compound.
Journal Article↗
Visual search for colour targets that are or are not linearly separable from distractors.
D'Zmura [(1991) Vision Research, 31, 951-966] reported qualitative differences in visual search rates for a target colour in a background of differently coloured distractors depending on their colour configuration in CIE(x,y) space. A target colour that was chromatically mid-way between the distractor colours resulted in steep search slopes. A target off the distractor-distractor line, "popped out". We replicated his finding in several loci, investigated several potential confounds, and discovered boundary conditions for the phenomenon: for a given target, the effect of collinearity dissipates with increasing distractor-distractor colour difference. Furthermore, within limits, performance was dependent on the target to distractor-line distance.
Adult↗
Stimulus dimensionality effects in mental rotation.
Do 3-dimensional (3-D) figures require more time to rotate mentally than do 2-dimensional (2-D) figures? This question was examined in 2 experiments incorporating 15 2-D and 15 3-D stimuli. For 3-D stimuli, block figures were used of the type used by R. N. Shepard and J. Metzler in their classic studies. For 2-D stimuli, block figures were also used, but with all cubes in a single plane, resulting in 2-D and 3-D figures matched on surface features. Three-D figures elicited steeper slopes than did 2-D figures, supporting the view that the mental rotation of visual representations is sensitive to stimulus dimensionality. The authors summarize the results of several mental rotation studies that investigated stimulus dimensionality and suggest that the evidence across studies is consistent with the present finding. They discuss 2 plausible loci for the dimensionality effect in S. M. Kosslyn's (1980) theory of mental imagery.
Adolescent↗
Protein kinase C-theta isoenzyme selective stimulation of the transcription factor complex AP-1 in T lymphocytes.
T-lymphocyte stimulation requires activation of several protein kinases, including the major phorbol ester receptor protein kinase C (PKC), ultimately leading to induction of lymphokines, such as interleukin-2 (IL-2). The revelant PKC isoforms which are involved in the activation cascades of nuclear transcription factors involved in IL-2 production have not yet been clearly defined. We have examined the potential role of two representative PKC isoforms in the induction of the IL-2 gene, i.e., PKC-alpha and PKC-theta, the latter being expressed predominantly in hematopoietic cell lines, particularly T cells. Similar to that of PKC-alpha, PKC-theta overexpression in murine EL4 thymoma cells caused a significant increase in phorbol 12-myristate 13-acetate (PMA)-induced transcriptional activation of full-length IL-2-chloramphenicol acetyltransferase (CAT) and NF-AT-CAT but not of NF-IL2A-CAT or NF-kappaB promoter-CAT reporter gene constructs. Importantly, the critical AP-1 enhancer element was differentially modulated by these two distinct PKC isoenzymes, since only PKC-theta but not PKC-alpha overexpression resulted in an approximately 2.8-fold increase in AP-1-collagenase promoter CAT expression in comparison with the vector control. Deletion of the AP-1 enhancer site in the collagenase promoter rendered it unresponsive to PKC-theta. Expression of a constitutively active mutant PKC-theta A148E (but not PKC-alpha A25E) was sufficient to induce activation of AP-1 transcription factor complex in the absence of PMA stimulation. Conversely, a catalytically inactive PKC-theta K409R (but not PKC-alpha K368R) mutant abrogated endogenous PMA-mediated activation of AP-1 transcriptional complex. Dominant negative mutant Ha-RasS17N completely inhibited the PKC-O A148E-induced signal, PKC-O. Expression of a constitutively active mutant PKC-O A148E (but not PKC-alpha A25E) was sufficient to induce activation of AP-1 transcription factor complex in the absence of PMA stimulation. Conversely, a catalytically inactive PKC-O K409R (but not PKC-alpha K368R) mutant abrogated endogenous PMA-mediated activation of AP-1 transcriptional complex. Dominant negative mutant Ha-enRasS17N completely inhibited in the PKC-O A148E-induced signal, identifying PKC-theta as a specific constituent upstream of or parallel to Ras in the signaling cascade leading to AP transcriptional activation.
Animals↗
Activated protein C resistance in young adults with central retinal vein occlusion.
BACKGROUND: Central retinal vein occlusion is a disease that is most common in old people. While the disease in old people often is associated with atherosclerosis, hypertension, diabetes, or glaucoma, this is much less evident in young people. However, a new defect in the anticoagulant system has recently been discovered, activated protein C resistance. This hereditary defect may well be associated with central retinal vein occlusion, and so this factor was analysed in patients younger than 50 years with a history of central retinal vein occlusion. METHODS: Blood samples were obtained from 31 patients younger than 50 years with a history of central retinal vein occlusion, and analysed for activated protein C resistance with standard clinical laboratory methods. RESULTS: In this material 26% of all the patients and 36% of the patients younger than 45 years were resistant to activated protein C. The normal incidence of activated protein C resistance is 2-7%. CONCLUSION: Activated protein C resistance seems to be the most common known cause of central retinal vein occlusion in young people.
Adult↗
The renin-angiotensin system and coronary vasomotion.
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Angiotensin I↗
Ramipril and felodipine: a comparison of the efficacy and safety of monotherapy versus combination therapy.
A multinational, double-blind, randomised study was conducted to investigate the efficacy and safety of a low-dose combination of the angiotensin converting enzyme inhibitor, ramipril, and the calcium antagonist, felodipine ER, in 642 patients with mild to moderate hypertension [supine diastolic blood pressure (DBP) = 95-115 mm Hg]. After a 4-week single-blind placebo run-in, patients were randomly allocated to once-daily felodipine extended release (ER; 2.5 mg), ramipril (2.5 mg) or felodipine ER/ramipril (2.5/2.5 mg) for 12 weeks. In the intention-to-treat analysis, mean DBP decreased significantly (p < 0.0001) after felodipine ER, ramipril and the combination (-9.1, -9.8 and -11.4 mm Hg, respectively). The decrease was significantly greater with the combination than with felodipine ER monotherapy (p = 0.02). The number of responding patients (final DBP < or = 90 mm Hg or a decrease of > or = 10 mm Hg) was also higher with the combination than with felodipine ER or ramipril monotherapy (65.1%, 53.1%, 55.7%, respectively). There were no differences between the three groups with respect to the incidence of adverse events overall or those considered treatment-related. There were fewer cases of peripheral oedema with combination therapy than with felodipine ER monotherapy. Thirty-three patients (5.1%) withdrew from the study because of adverse events, but there was no clear pattern with regard to the specific events leading to withdrawal. There were no clinically relevant changes in laboratory or clinical safety variables. Ramipril/felodipine ER 2.5/2.5 mg is an appropriate starting dosage when initiating combination antihypertensive therapy.
Adult↗
Ergotamine-induced headache associated with cluster headache.
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Adult↗
Fixed dose combinations of ACE inhibitors.
First-line antihypertensive monotherapy is effective in reducing blood pressure to within the normal range in approximately 50% of patients. Normalisation in the remaining patients may require a combination of two or more drugs. This review considers the clinical efficacy and tolerability of combinations involving angiotensin-converting enzyme (ACE) inhibitors. The efficacy of combinations with diuretics or calcium antagonists, as initial therapy or in patients with inadequate responses to monotherapy, has been demonstrated in many trials. With combination therapy, normalisation rates approaching 80% can be achieved using submaximal doses of both components. Therapy with both combinations is well tolerated; with ACE inhibitors reducing the diuretic metabolic effects or counteracting some calcium antagonist-associated vasodilatory effects. Data on ACE inhibitors with beta-blockers are limited. When patients respond inadequately to first-line monotherapy, the increasing availability of drug combinations will allow individual selection of the most appropriate combination, taking account of additional risk factors and concomitant disease.
Adrenergic beta-Antagonists↗
The impact of three-dimensional structure on the expression of PlA alloantigens on human integrin beta 3.
We have compared the binding of affinity-purified anti-PlA1 IgG from seven nonrelated donors with chimeric integrin subunit beta 3 molecules expressed in the baculovirus-Spodoptera frugiperda insect cell system. Beta 3 chimeras were engineered to include segments of antigenic human beta 3 sequences spliced to intervening segments of nonantigenic Xenopus beta 3 sequence. Our results clearly show that antibodies from all seven donors will bind to nondenatured molecules containing the antigenic human beta 3 Cys26-Cys38 loop only when it is presented in a correct orientation that must be maintained by noncontiguous human sequences. Key downstream sequences are located within the region beta 3(288-490), flanking either side of the putative long-range disulfide at Cys435. Although our results confirm unambiguously that the Leu/Pro polymorphism at position 33 in human beta 3 is necessary for the expression of PlA epitopes, they also indicate that this polymorphic sequence alone is not sufficient. The requirement for additional human beta 3 sequence transcends the need to maintain a correct orientation within the Cys26-Cys38 loop itself, because the murine monoclonal antibody SZ21, which recognizes the sequence beta 3(28-35) contained within the Cys26-Cys38 loop, binds to all chimeras containing this loop, even if the same chimeras are not recognized by anti-PlA1. Our results indicate that additional noncontiguous residues encompassed by the sequence 288-490 either directly contribute to the composition of the PlA1 epitope or, more likely, maintain the Cys26-Cys38 loop in a proper orientation with respect to the remainder of the beta 3 molecule and thereby maintain proper antigenic presentation of the sequences in that loop.
Amino Acid Sequence↗
Binge eating in massively obese patients undergoing bariatric surgery.
Data on the prevalence of binge eating in a series of 92 massively obese patients undergoing bariatric surgery are presented. A semistructured clinical interview demonstrated that 63 individuals had problems with binge eating, 43 of these reporting episodes of binge eating more than twice a week and then meeting the diagnostic criteria for binge eating disorder. By comparison with their nonbinge eating counterparts, binge eaters demonstrated higher body weight, greater weight fluctuation due to reducing diets in their past lifetime, higher Three-Factor Eating Questionnaire Disinhibition and Hunger score, and an overall higher psychopathology as assessed by the Eating Disorder Inventory. The great prevalence of binge eating in these patients could be accounted for by the high body weight, by the characteristics of the patients, or by the context in which the eating behavior assessment was carried out.
Adolescent↗
Lack of concordant p53 mutations in some paired primary and metastatic mouse squamous cell carcinomas induced by chemical carcinogenesis.
We studied the frequency and pattern of p53 mutations in 16 mouse skin primary squamous carcinomas induced by chemical carcinogens and their 19 matched metastases. The molecular changes were analyzed by polymerase chain reaction-single-strand conformation polymorphism and subsequent direct sequencing analysis. Eleven mutations of the p53 gene were detected in a total of eight primary tumors, and 10 mutations were detected in nine metastases. Only four pairs had identical mutations in primary and paired metastatic tumors. Eight mutations in six pairs were detected in primary tumors but not in their metastases, and four mutations from three matched pairs were detected in metastases but not in primary tumors. The four pairs that contained the same mutations in both the primary and secondary tumors had lymph-node metastases, and all mutations occurred in exon 8. Conversely, five of six pairs with p53 mutations only in primary tumors had lung metastases, and only one of the mutations occurred in exon 8. None of the mutations found only in metastases were located in exon 8. These data indicate that p53 mutations are prevalent in lymph-node metastases and infrequent in lung metastases of mouse skin tumors and that primary tumors with exon 8 mutations may be more likely to metastasize to the lymph nodes.
Animals↗
Binge eating following biliopancreatic diversion for obesity.
The prevalence of binge eating disorder (BED) was assessed in 68 massively obese patients prior to and following biliopancreatic diversion (BPD) for obesity. The eating behavior and the psychological traits were evaluated by the Three Factor Eating Questionnaire and the Eating Disorder Inventory. Since after BPD the body weight regulation is substantially dependent on intestinal absorption, the individuals operated on have to be considered as absolutely free eaters. In this population, 30 patients were affected by BED and in 24 of them binge eating disappeared spontaneously following BPD, highlighting the main role of preoccupation with food, diet and overweight in causing or in maintaining BED.
Adolescent↗
Molecular cloning and analysis of nre, the major nitrogen regulatory gene of Penicillium chrysogenum.
We have isolated the Penicillium chrysogenum nre gene which is homologous to the major nitrogen regulatory genes areA from Aspergillus nidulans and nit-2 from Neurospora crassa. Overall, nre shows 60% identity to areA and 30% identity to nit-2 at the amino-acid level. The gene encodes a protein of 835 amino-acid residues and contains a single Cys2/Cys2-type zinc finger with an adjacent basic region and a putative acidic activation region. In the DNA-binding domain, 98% of the amino-acid residues are identical in nre, areA and nit-2. The nre gene has been shown to be functional in N. crassa by heterologous complementation of a nit-2 mutant. Growth tests indicated that transformants could utilize nitrate, amino-acids, purines and amides as sole nitrogen sources. Nitrate reductase activity assays performed with transformants demonstrated that nitrogen control was completely normal. Complementation of N. crassa nit-2 mutants with 5'-deletion clones of nre suggests the possible presence of an internal promoter within the coding region. Northern analysis and ribonuclease protection assays of total cellular RNA indicated that nre encodes a 3.2-kb transcript which is reduced in content under conditions of nitrogen repression.
Amino Acid Sequence↗