Apolipoprotein E polymorphism and silent microangiopathy-related cerebral damage. Results of the Austrian Stroke Prevention Study

BACKGROUND AND PURPOSE

Microangiopathy-related cerebral damage (MARCD) includes white matter abnormalities and lacunar infarctions and represents a common MRI observation in subjects above 50 years of age. The risk factors of such brain abnormalities are not fully determined. The goal of this study was to determine whether the genetic heterogeneity of apolipoprotein E (apoE) contributes to the occurrence of MARCD.

METHODS

Brain MRI (1.5 T) was performed in 280 individuals (ages 50 to 75 years) without neuropsychiatric disease randomly selected from the official register of residents of the city of Graz, Austria. All study participants underwent apoE genotyping, carotid Doppler sonography, electrocardiography, echocardiography, and a complete blood chemistry panel. MARCD was defined as evidence of early confluent and confluent white matter hyperintensities or lacunes. Carotid atherosclerosis was graded on a five-point scale ranging from not present (0) to complete occlusion (5).

RESULTS

MARCD occurred in 61 individuals (21%). The distribution of apoE genotypes differed significantly between subjects with and without MARCD (P = .036). Subjects with such findings more commonly had the epsilon 2/epsilon 3 genotype (24.6% versus 10%) at similar frequencies of genotypes containing the epsilon 4 allele. The epsilon 2/epsilon 3 genotype was associated with lower levels of total cholesterol (P = .0009), LDL cholesterol (P = .00001), and apolipoprotein B (P = .00001). Also, there was a nonsignificant trend toward less cardiac disease. Other major vascular risk factors and carotid abnormalities were similar among the various genotypes. Multiple logistic regression analysis created a model of significant MARCD predictors, including age (odds ratio [OR], 1.1 per year), hypertension (OR, 3.4), and the apoE epsilon 2/epsilon 3 genotype (OR, 3.0).

CONCLUSIONS

These data suggest an association between the apoE epsilon 2/epsilon 3 genotype and MARCD despite favorable effects on the lipid profile and cardiac disease.

[Rare localization of a monstrous thymoma in the anterior inferior mediastinum]

90% of all thymomas are localized in the anterior-superior mediastinum, seldom in the inferior or posterior mediastinum. We report the rare case of a 61 year-old female patient who presented with a large thymoma of the anterior-inferior mediastinum with the chief complaint of position-dependent dyspnoea secondary to compression of the left lung. Surgical resection of a tumor weighing 1053 g was successfully performed and 8 months postoperatively the patients is asymptomatic and without evidence of recurrence.

A novel zinc finger protein is encoded by the Arabidopsis LSD1 gene and functions as a negative regulator of plant cell death

Arabidopsis Isd1 mutants are hyperresponsive to cell death initiators and fail to limit the extent of cell death. Superoxide is a necessary and sufficient signal for cell death propagation. Thus, LSD1 monitors a superoxide-dependent signal and negatively regulates a plant cell death pathway. We isolated LSD1 via its map position. The predicted LSD1 protein contains three zinc finger domains, defined by CxxCxRxxLMYxxGASxVxCxxC. These domains are present in three additional Arabidopsis genes, suggesting that LSD1 defines a zinc finger protein subclass. LSD1 is constitutively expressed, consistent with the mutant phenotype. Alternate splicing gives rise to a low abundance mRNA encoding an extra five amino-terminal amino acids. We propose that LSD1 regulates transcription, via either repression of a prodeath pathway or activation of an antideath pathway, in response to signals emanating from cells undergoing pathogen-induced hypersensitive cell death.

The impact of sociodemographic, environmental, and behavioral factors, and cerebrovascular risk factors as potential predictors of the mattis dementia rating scale

BACKGROUND

Age and education have been found to affect the Mattis Dementia Rating Scale (MDRS) score of elderly normals, but there have been no studies assessing the influence of environmental and behavioral factors on this scale. Their role as potential predictors of the MDRS total score was investigated.

METHODS

The MDRS was administered to 1,927 normal elderly subjects in the setting of a stroke prevention study. Results were correlated with 16 sociodemographic, environmental, and behavioral factors, and cerebrovascular risk factors. Study statistics resulted from multiple logistic regression analysis.

RESULTS

Results indicated that higher age and arterial hypertension were associated with poorer cognitive performance, while better education and moderate general life stress exerted a positive effect on the participants' test results.

CONCLUSIONS

Thus, besides the well-established factors of age and educational level, moderate general life stress and hypertension were identified as relevant predictors in determining the MDRS test performance of elderly normals.

[Surgical treatment of chronic ankle joint instability--many variations in German clinics. Analysis of a 1994 German survey]

A questionnaire was mailed to 400 orthopaedic department chairpersons in Germany listed by the "Deutsche Gesellschaft für Unfallchirurgie" to evaluate the current surgical approach to chronic ankle instability. The aim of the survey was to analyze and to classify the reconstruction method of the individual institution. Questionnaires were returned from 267 hospitals (66.7%). The number of ligament reconstructions performed at individual institutions ranged from 1 to over 100 (mean 17.5). The most frequently used procedures of primary choice for reconstruction of the ligaments are: periosteal flaps (45.3%), anatomical repair (23.6%), different tenodeses (20.6%), and free anatomical implants of autologous or exogenous material (10.5%). 50% of the participants use reconstructions in which the injured ligament is repaired secondarily without augmentation or with periosteal flaps. The remaining part of the German surgeons prefers tenodeses or various other procedures. It is interesting to note that there is a high number of different procedures not namely known in the literature which are considered as individual modifications. With better knowledge of the function of the single ligament and general exposure of the ligaments for simple overlap and direct suture, the rate of primary non-anatomical reconstructions may be decreased in the future.

Description of 31 YAC contigs spanning the majority of Arabidopsis thaliana chromosome 5

In order to generate a physical map of Arabidopsis thaliana chromosome 5, 142 molecular markers mapping chromosome 5 have been used in colony hybridization experiments with four Arabidopsis, ecotype Columbia, yeast artificial chromosome (YAC) libraries. This resulted in 634 YAC clones being anchored on chromosome 5. Southern blot analysis confirmed their positioning and provided data, which along with knowledge of the sizes of all the YAC clones, enabled the clones to be arranged into 31 contigs. Genetic mapping of markers located within 29 of these contigs on the Landsberg erecta/Columbia recombinant inbred lines allowed positioning of the contigs along the chromosome. A high proportion of the YAC clones were found to contain chimaeric inserts. The availability of this YAC contig map will accelerate chromosome-walking experiments, provide substrates for large-scale genomic sequencing projects and facilitate the mapping of new probes to this chromosome.

A case-based consiliarius for therapy recommendation (ICONS): computer-based advice for calculated antibiotic therapy in intensive care medicine

We report here on the system ICONS which utilizes case-based reasoning for medical decision support. As an application domain we have chosen the medical field of 'calculated antibiotic therapy' in an intensive care medicine setting. The system ICONS which runs on a personal computer suggests adequate antibiotic therapy regimen satisfying medical and economic conditions. To speed up the process of finding an adequate antibiotic therapy for a current patient, case-based reasoning is used for finding previously documented similar cases and for modifying them according to the requirements of the current patient. To reduce the memory capacity for the documentation of cases, collections of similar cases are clustered to prototypes. Medical knowledge is represented within a hierarchy of such prototypes and cases and an additional context-sensitive background knowledge-base. A knowledge acquisition tool was programmed that allows revisions of the background medical knowledge-base by simple and comprehensive methods. In addition to the advantage of producing site-specific and time-dependent knowledge, case-based reasoning is a practical method for speeding-up the process of generating and evaluating hypotheses in medical classification tasks.

Identification of mutants in metabolically regulated gene expression

Sucrose is the main transported form of assimilates, but, significantly, it also regulates a variety of processes such as photosynthesis and carbon or nitrogen storage. The effects of high sucrose levels are mediated directly by modulation of gene expression. The regulation of storage protein accumulation, here patatin from potato tubers, was used as a model system to study sucrose mediated signal transduction. The transcriptional regulation of patatin genes in conserved in transgenic Arabidopsis, as shown by the analysis of expression of two classes of patatin promoters fused to uidA. Two distinctly different patterns of gene expression were observed. In roots, class I promoter expression is strongly dependent on the exogenous supply of sugars. 3-O-methylglucose induction indicates that the sensor is located upstream of hexokinase. In contrast, the class II promoter is constitutively active in root tips and hydatodes. The progeny of a homozygous class I line was mutagenized with ethyl methane sulphonate and screened for signal transduction mutants using a non-destructive screening system for GUS activity. Four mutants showing reduced sucrose responses (rsr) and two mutants with modified expression patterns (mep) regarding the root tip were identified. In backcross analyses, it was shown that rsr1-1 carries a recessive trans mutation whereas rsr4-1 seems to be a semi-dominant trans mutation in sugar-mediated gene regulation.

[Prevalence and risk factors in the population of Graz (Austrian Stroke Prevention Study)]

The Austrian Stroke Prevention Study recruited 1960 randomly selected subjects aged 50 to 75 years during a 3-year period of enrollment. The response rate of the study was 32.4%. A telephone interview with 200 randomly selected non-responders yielded no differences to responders regarding the frequency of major vascular risk factors known to the subjects. Besides demographics, the study assessed arterial hypertension, diabetes mellitus, cardiac disease, smoking, a complete lipid status including the apolipoprotein-E genotype, serum fibrinogen and anticardiolipin antibodies as well as various natural antioxidants such as vitamins A, C, E and beta-carotene. Arterial hypertension, diabetes mellitus, cardiac disease and hypercholesterolemia > 200 mg/dl were strikingly common and occurred in 38%, 7.6%, 32% and 76%, respectively. Suboptimal plasma concentrations of vitamin A, E, and beta-carotene were noted in 77.2%, 56.1% and in 53.2% of study participants. The rate of treatment of major risk factors known to the subjects prior to study entry were 60.3% and 70% for arterial hypertension and diabetes mellitus, but only 37.1% and 6.3% for cardiac disease and hypercholesterolemia > 250 mg/dl. Diet was commonly used to treat diabetes but was almost neglected in the treatment of other vascular risk factors. These data provide an orientation on the prevalence of risk factors and the use of primary preventive measures for stroke treatment in our community.

The mutation masculinizer (man) defines a sex-determining gene with maternal and zygotic functions in Musca domestica L

In Musca domestica, the primary signal for sex determination is the dominant factor M, which is assumed to regulate a postulated female-determining gene F. Presence of M prevents expression of F so that male development ensues. In the absence of M, F can become active, which dictates the female pathway. The existence of F is inferred from FD. a dominant factor that is epistatic to M. We describe a new mutation masculinizer, which has all the properties expected for a null or strongly hypomorphic allele of F: (1) it maps to the same chromosomal location as FD, (2) homozygous man/man animals develop as males, (3) homozygous man/man clones generated in man/+ female larvae differentiate male structures, (4) man has a sex-determining maternal effect. About a third of the morphological males synthesize yolk proteins, which indicates that they are intersexual in internal structures. The maternal effect of man is complete in offspring that derive from homozygous man/man pole cells transplanted into female hosts. In this case, all man/+ progeny become fertile males that do not produce yolk proteins A sex-determining maternal effect has previously been demonstrated for FD. Like F, maternal man' is needed for zygotic man' to become active, providing further evidence that man is a loss-of-function allele of F.

LPFC: an Internet library of protein family core structures

As the number of protein molecules with known, high-resolution structures increases, it becomes necessary to organize these structures for rapid retrieval, comparison, and analysis. The Protein Data Bank (PDB) currently contains nearly 5,000 entries and is growing exponentially. Most new structures are similar structurally to ones reported previously and can be grouped into families. As the number of members in each family increases, it becomes possible to summarize, statistically, the commonalities and differences within each family. We reported previously a method for finding the atoms in a family alignment that have low spatial variance and those that have higher spatial variance (i.e., the "core" atoms that have the same relative position in all family members and the "non-core" atoms that do not). The core structures we compute have biological significance and provide an excellent quantitative and visual summary of a multiple structural alignment. In order to extend their utility, we have constructed a library of protein family cores, accessible over the World Wide Web at http:/ /www-smi.stanford.edu/projects/helix/LPFC/. This library is generated automatically with publicly available computer programs requiring only a set of multiple alignments as input. It contains quantitative analysis of the spatial variation of atoms within each protein family, the coordinates of the average core structures derived from the families, and display files (in bitmap and VRML formats). Here, we describe the resource and illustrate its applicability by comparing three multiple alignments of the globin family. These three alignments are found to be similar, but with some significant differences related to the diversity of family members and the specific method used for alignment.

Pyogenic infectious spondylitis: clinical, laboratory and MRI features

Pyogenic infectious spondylitis (PIS) is an uncommon but serious inflammatory disorder of the discovertebral junction with frequent involvement of neural structures including the spinal cord. We report a series of 41 patients (age range 21-75 years, mean age 59 years) with primary PIS confirmed by signal abnormality of the intervertebral disk and adjacent vertebral bodies on magnetic resonance imaging. The prevailing clinical symptom was focal back pain aggravated by percussion in 90% of patients. Radicular signs or symptoms were present in 59% and spinal cord symptoms in 29% of patients, respectively. Evidence of inflammation consisted of an elevated sedimentation rate in 76%, leukocytosis in 61% and fever in 61% of individuals. Predisposing factors such as diabetes mellitus, previous nonspinal surgery and other sites of infection or inflammation were identified in 17 (41%) patients and 30 (73%) were older than 50 years. The lumbar spine was most often affected and PIS was associated with an epidural abscess in 15 (37%) patients. Increased alertness for PIS in the context of focal back pain with clinical or laboratory signs of inflammation is needed to speed up its detection.

Structural modifications of the N-terminal tetrapeptide segment of [D-Ala2]deltorphin I: effects on opioid receptor affinities and activities in vitro and on antinociceptive potency

A series of deltorphin I analogs containing D- or L-N-methylalanine (MeAla), D- or L-proline (Pro), alpha-aminoisobutyric acid (Aib), sarcosine (Sar) or D-tert-leucine (Tle) in place of D-Ala2, or phenylalanine in place of Tyr1, was synthesized. The opioid activity profiles of these peptides were determined in mu and delta opioid receptor-representative binding assays and bioassays in vitro as well as in the rat tail flick test in vivo. In comparison with the deltorphin I parent, both the L- and the D-MeAla2-analog were slightly more potent delta agonists in the mouse vas deferens (MDV) assay, and the D-MeAla2-analog showed two-fold higher antinociceptive potency in the analgesic test. In view of the fact that deltorphin analogs with an unsubstituted L-amino acid residue in the 2-position generally lack opioid activity, the observed high delta opioid potency of [L-MeAla2]deltorphin I is postulated to be due to the demonstrated presence of a conformer with a cis Tyr1-MeAla2 peptide bond, since the cis conformer allows for a spatial arrangement of the pharmacophoric moieties in the N-terminal tripeptide segment similar to that in active deltorphin analogs containing a D-amino acid residue in the 2-position. Substitution of Aib in the 2-position led to a compound, H-Tyr-Aib-Phe-Asp-Val-Val-Gly-NH2, which displayed lower delta receptor affinity than the parent peptide but higher delta selectivity and, surprisingly, three times higher antinociceptive potency. The D- and L-Pro2-, Sar2- and D-Tle2-analogs showed much reduced delta receptor affinities and were inactive in the tail flick test. Replacement of Tyr1 in deltorphin I with Phe produced a 32-fold decrease in delta receptor affinity but only a 7-fold drop in antinociceptive potency.

Expression of the RET/PTC fusion gene as a marker for papillary carcinoma in Hashimoto's thyroiditis

Hashimoto's thyroiditis is an inflammatory disease of the thyroid gland with autoimmune etiology. Patients afflicted with Hashimoto's have a higher risk of thyroid malignancies such as papillary thyroid carcinoma. In the present study, we investigated the frequency of papillary thyroid carcinoma specific genes in patients diagnosed with Hashimoto's disease. The newly identified oncogenes RET/PTC1 and RET/PTC3 provide useful and specific markers of the early stages of papillary carcinoma as they are highly specific for malignant cells. Using a sensitive and specific reverse transcriptase-polymerase chain reaction (RT-PCR) assay, we found messenger RNA (mRNA) expression for the RET/PTC1 and RET/PTC3 oncogenes in 95% of the Hashimoto's patients studied. All Hashimoto's patients presenting without histopathologic evidence of papillary thyroid cancer showed molecular genetic evidence of cancer. These data suggest that multiple, independent occult tumors exist in these patients at high frequency.

Cyclic morphiceptin analogs: cyclization studies and opioid activities in vitro

Attempts were undertaken to develop cyclic beta-casomorphin-5 analogs with improved opioid activity profiles by deletion of the glycine residue in position 5, leading to analogs structurally related to the opioid peptide morphiceptin (H-Tyr-Pro-Phe-Pro-NH2). The tetrapeptide sequence Boc-Tyr(tBu)-D-Xaa-Phe-Yaa-OH (Xaa = Lys, Orn, A2bu; Yaa = Pro in L- or D-configuration) was used to study the influence of ring size and chirality on the yield of cyclization between the omega-amino group of Xaa and the C-terminal carboxyl group. In all cases the cyclization reaction was performed under identical experimental conditions to allow a direct comparison with regard to yield and homogeneity. The reaction products were purified by crystallization and liquid chromatography, and were characterized by HPLC, TLC, electrospray mass spectrometry and 1H-NMR spectroscopy. In none of the reactions performed with the cyclization precursors containing proline in the L-configuration could a cyclic monomer be detected, and the cyclodimer (7-9) was the exclusive product in each case. Cyclodimerization was also the favored reaction in the attempted formation of the 11-membered ring of the cyclic [D-A2bu2, D-Pro4]-morphiceptin analog 12, since only traces of the monomer were found. In the case of both the [D-Lys2, D-Pro4]-analog 10 and the [D-Orn2, D-Pro4]-analog 11, the cyclomonomer/cyclodimer ratio was about 80:20. The cyclic monomers 10 and 11 showed high opioid activity in the mu-receptor-representative guinea pig ileum assay (IC50 = 2-5 nM) and in the delta-receptor representative mouse vas deferens assay (IC50 = 50-60 nM), whereas the potency of the cyclodimers was 2-3 orders of magnitude lower in both in vitro bioassays.

Keloid excision and recurrence prophylaxis via intradermal interferon-gamma injections: a pilot study

Keloids are an abnormal response to wound healing distinguished by an overproduction of collagen. Thickened bundles of collagen in the reticular dermis oriented haphazardly in relation to the overlying epithelium are found in keloids, in contrast to thinner collagen fibers in a more orderly arrangement that are found in normal scars. Previous clinical trials of intralesional interferon-gamma (IFN-G) injections by Larrabee et al. and Granstein et al. showed a decrease in lesion size. These findings led to a conclusion that IFN-G would be a useful adjunct to surgical excision of keloids to aid in preventing recurrence. We performed a double-blind, placebo-controlled trial in patients with two or more keloids treated with excision and subsequent local injections of IFN-G or placebo.

Structure/activity relationships of polyfunctional diterpenes of the tigliane type. A pharmacophore model for protein-kinase-C activators based on structure/activity studies and molecular modeling of the tumor promoters 12-O-tetradecanoylphorbol 13-acetate and 3-O-tetradecanoylingenol

For protein kinase C (PKC), a family of isoenzymes with serine/threonine-kinase activity identified as the major cellular receptor for certain skin irritants and tumor promoters, a new pharmacophore model is presented. By structure/activity relationship studies of naturally occurring and synthetic diterpene esters of the tigliane type (PKC activators) it is demonstrated that in addition to the oxygen at C20 it is the O-acyl function in position C13 which is critically essential for skin-irritant and tumor-promoting bioactivities rather than other oxygen atoms. This result is confirmed and extended by computer-assisted molecular modeling of tigliane-type and ingenane-type tumor promoters. It is contrasted to certain features attributed to the pharmacophore based upon the recently determined crystallographic structure of the effector-binding domain Cys2 of PKC delta complexed with the pseudo-agonist phorbol 13-acetate.

A novel repetitive sequence associated with the centromeric regions of Arabidopsis thaliana chromosomes

The middle repetitive fraction of the Arabidopsis genome has been relatively poorly characterized. We describe here a novel repetitive sequence cloned in the plasmid mi167, and present in approximately 90 copies in the genome of Arabidopsis thaliana ecotype Columbia. Hybridization analysis to physically mapped YAC clones representing Arabidopsis chromosome 4 revealed four mi167-hybridizing loci, all clustered near the centromere. No other loci were detected on YAC clones covering chromosome 4. In situ hybridisation experiments to Arabidopsis chromosome spreads showed that mi167-hybridizing sequences are clustered at the centromeric heterochromatin of all five chromosomes; on two chromosomes the hybridization appeared to be localised on one arm. Additional mi167-hybridizing loci were detected, one of which was adjacent to a non-centromeric, heterochromatic region. This work supports the idea that the majority of middle repetitive DNA in the Arabidopsis genome is clustered. It also adds to our understanding of the organization of the centromere of Arabidopsis chromosome 4.

[Polyneuropathy, diarrhea]

A 44-year-old patient with 24 kg reduction of body weight within three years due to recurrent diarrhea was admitted to the hospital. Physical findings of the patient were not remarkable, except for hypesthesia and hypalgesia of the front of the tibia and of the lower legs. Laboratory as well as endoscopic and functional examinations of the gastrointestinal tract did not reveal any remarkable finding. Infectious origins of the disease were excluded. A histological examination of a rectum specimen yielded amyloid deposits in the submucosa of the rectum. In the family history of the patient, relatives with liver and gastrointestinal diseases due to amyloidosis were detected. Amyloid deposits and the positive family history of the patient led to the diagnosis of a gastrointestinal manifestation of familial amyloidosis.

The listerial exotoxins listeriolysin and phosphatidylinositol-specific phospholipase C synergize to elicit endothelial cell phosphoinositide metabolism

Exotoxins such as listeriolysin (LLO) and phosphatidylinositol-specific phospholipase C (PIcA) have been implicated in listerial infection and sepsis. Employing different Listeria strains, mutated in individually known virulence genes, we examined exotoxin-related induction of endothelial cell signaling. Listeria monocytogenes was a potent inductor of phosphatidylinositol (PtdIns) metabolism in HUVEC. This effect was completely absent in a LLO-negative strain. Using a recombinant Listeria innocua strain, engineered to produce high levels of LLO, PtdIns metabolism was restored to approximately 30% of that produced by the parental L. monocytogenes strain. A recombinant L. innocua strain expressing only PIcA did not induce any PtdIns metabolism. Even higher than wild-type levels of PtdIns hydrolysis products were, however, evoked when engineered bacteria secreted both LLO and PIcA. These effects occurred in the absence of bacterial uptake by the endothelial cells. Corresponding results were observed with regard to endothelial diacylglycerol (DAG) generation. The amplification of endothelial cell signaling could be reproduced by engaging purified LLO and PIcA in the absence of bacteria. In these experiments, the unrelated pore-forming agent staphylococcal alpha-toxin, a very weak stimulus for endothelial phosphoinositide metabolism by itself, substituted for LLO to allow marked PtdIns hydrolysis when co-applied with PIcA. We conclude that the listerial exotoxins LLO and PIcA cooperate to provoke potent second messenger synthesis in endothelial cells, in the absence of cell invasion by the bacteria. This is an impressive example of synergism between a pore-forming and an enzymatic bacterial exotoxin in provoking cell signaling and inflammatory events.