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1.
PLoS One ; 19(6): e0301002, 2024.
Article in English | MEDLINE | ID: mdl-38848328

ABSTRACT

The known diversity of European middle and late Miocene hominids has increased significantly during the last decades. Most of these great apes were frugivores in the broadest sense, ranging from soft fruit frugivores most like chimpanzees to hard/tough object feeders like orangutans, varying in size from larger than siamangs (over 17 kg) to larger than most chimpanzees (~60-70 kg). In contrast to the frequent sympatry of hominoids in the early-to-middle Miocene of Africa, in no European Miocene locality more than one hominid taxon has been identified. Here we describe the first case of hominid sympatry in Europe from the 11.62 Ma old Hammerschmiede HAM 5 level, best known from its excellent record of Danuvius guggenmosi. The new fossils are consistent in size with larger pliopithecoids but differ morphologically from any pliopithecoid and from Danuvius. They are also distinguished from early and middle Miocene apes, share affinities with late Miocene apes, and represent a small hitherto unknown late Miocene ape Buronius manfredschmidi. With an estimated body mass of about 10 kg it represents the smallest known hominid taxon. The relative enamel thickness of Buronius is thin and contrasts with Danuvius, whose enamel is twice as thick. The differences between Buronius and Danuvius in tooth and patellar morphology, enamel thickness and body mass are indicative of differing adaptations in each, permitting resource partitioning, in which Buronius was a more folivorous climber.


Subject(s)
Fossils , Hominidae , Animals , Fossils/anatomy & histology , Hominidae/anatomy & histology , Germany
2.
Ann Oncol ; 23(12): 3180-3187, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22858558

ABSTRACT

BACKGROUND: Reliable biomarkers of sunitinib response in gastrointestinal stromal tumor (GIST) are lacking. Hypertension (HTN), an on-target class effect of vascular endothelial growth factor signaling-pathway inhibitors, has been shown to correlate with clinical outcome in advanced renal cell carcinoma treated with sunitinib. PATIENTS AND METHODS: This retrospective analysis examined correlations between sunitinib-associated HTN and antitumor efficacy (N = 319) and safety (N = 1565) across three advanced GIST studies. Blood pressure (BP) was measured on days 1 and 28 of each treatment cycle at a minimum. Time-to-event endpoints were estimated using Kaplan-Meier methods, and patient subgroups with and without HTN (maximum systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg) were compared using Cox proportional hazards models. Landmark analyses evaluated associations between early HTN and efficacy endpoints. Adverse events (AEs) were compared between groups. RESULTS: Sunitinib-associated HTN correlated with improved objective response rates, time to tumor progression, progression-free survival, and overall survival. Almost all benefits remained significant in multivariate and landmark analyses. Overall incidences of HTN-related AEs were low and similar between groups; incidences of cardiovascular AEs were somewhat higher in patients with HTN. CONCLUSION: Sunitinib-associated HTN appeared to correlate with improved clinical outcomes in GIST, while incidences of HTN-associated AEs were generally low and manageable.


Subject(s)
Benzamides/therapeutic use , Carcinoma, Renal Cell/drug therapy , Gastrointestinal Stromal Tumors/drug therapy , Hypertension/chemically induced , Indoles/therapeutic use , Piperazines/therapeutic use , Pyrimidines/therapeutic use , Pyrroles/therapeutic use , Adolescent , Adult , Aged , Aged, 80 and over , Angiogenesis Inhibitors/adverse effects , Angiogenesis Inhibitors/therapeutic use , Antineoplastic Agents/adverse effects , Antineoplastic Agents/therapeutic use , Benzamides/adverse effects , Biomarkers, Tumor , Blood Pressure/drug effects , Carcinoma, Renal Cell/pathology , Child , Disease-Free Survival , Female , Gastrointestinal Neoplasms/drug therapy , Gastrointestinal Neoplasms/pathology , Gastrointestinal Stromal Tumors/pathology , Humans , Imatinib Mesylate , Indoles/adverse effects , Kidney Neoplasms/drug therapy , Kidney Neoplasms/pathology , Male , Middle Aged , Piperazines/adverse effects , Proportional Hazards Models , Prospective Studies , Protein Kinase Inhibitors/adverse effects , Protein Kinase Inhibitors/therapeutic use , Pyrimidines/adverse effects , Pyrroles/adverse effects , Signal Transduction , Sunitinib , Treatment Outcome , Vascular Endothelial Growth Factor Receptor-2/metabolism , Vascular Endothelial Growth Factors/metabolism , Young Adult
3.
Anaesthesia ; 66(7): 568-73, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21539528

ABSTRACT

The insertion of an epidural catheter for labour analgesia may be challenging. This observational study compared pressures during insertion of an epidural catheter in pregnant (n = 35) and non-pregnant (n = 10) women, using an acoustic device for locating the epidural space that also records and stores pressure data during the procedure. In both groups, we compared the maximum pressure just before loss of resistance, the pressure in the epidural space and the pressure in the inserted epidural catheter. Maximum pressure just before loss of resistance in the pregnant women was significantly lower compared with the non-pregnant women. Pressures in the epidural space and with the disposable tubing connected to the inserted epidural catheter were greater in pregnant women than in non-pregnant women. The results support the hypothesis that physiological changes in the third trimester of pregnancy are the reason why epidural catheters are more difficult to insert in women in labour.


Subject(s)
Acoustics/instrumentation , Analgesia, Epidural/instrumentation , Analgesia, Obstetrical/instrumentation , Labor, Obstetric , Adult , Catheterization/instrumentation , Epidural Space/physiology , Equipment Design , Female , Humans , Pregnancy , Pressure , Young Adult
4.
Vet J ; 187(2): 267-8, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20810294

ABSTRACT

Twelve healthy cattle (weighing 188-835 kg) were placed in stocks and sedated with xylazine. Caudal epidural puncture was performed using an acoustic device that indicated a decrease in resistance with a change in pitch. Lidocaine was injected to verify correct needle placement by assessing needle prick stimuli applied on the left and right side of the tail root and the perineal region, and the loss of tail and anal sphincter tone. Pressure measurements were recorded during penetration of the different tissue layers and in the epidural space. A clear and sudden decrease in the pitch of the acoustic signal was audible in all 12 cattle. All cows showed clinical effects indicating successful epidural anaesthesia. The pressure in the epidural space after puncture was -19±10 mm Hg. The device may be of assistance in identifying the epidural space in cattle.


Subject(s)
Anesthesia, Epidural/veterinary , Auscultation/veterinary , Cattle/anatomy & histology , Epidural Space/anatomy & histology , Injections, Epidural/veterinary , Acoustics/instrumentation , Anesthesia, Epidural/methods , Animals , Auscultation/instrumentation , Cattle/physiology , Epidural Space/physiology , Injections, Epidural/methods , Pressure
5.
Eur J Anaesthesiol ; 21(9): 694-9, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15595581

ABSTRACT

BACKGROUND AND OBJECTIVE: In previous studies we have demonstrated that it is possible and safe to identify the lumbar epidural space by an acoustic and visible signal. The use of an experimental set-up constructed for this purpose, the acoustic puncture assist device, the lumbar epidural puncture procedure became both audible and visible. In the present study we have extended the use of the device to localize the thoracic epidural space. We have also evaluated whether the device can be used as a practical tool to confirm correct catheter placement. METHODS: In 100 consecutive patients a prototype of the acoustic puncture assist device was connected to the epidural needle in order to localize the epidural space. The device translates the pressure encountered by the needle tip into a corresponding acoustic and visible signal and enables the anaesthesiologist to detect the epidural space by means of the acoustic signal. After catheter insertion, local anaesthetic was administered. Subsequently the epidural block was tested. In 10 patients the device was also connected to the epidural catheter after its insertion into the epidural space. RESULTS: In all 100 patients included in the study the epidural space was successfully located by means of the acoustic signal. The only recorded complication was intravascular catheter placement in two patients. CONCLUSIONS: It is possible to localize the thoracic epidural space guided by an acoustic signal. The method was shown to be safe, reliable and simple. Potential implications of this technique include better needle control, improved monitoring for training purposes and for clinical documentation of the thoracic epidural puncture as well as identifying correct catheter placement.


Subject(s)
Acoustics , Anesthesia, Epidural/instrumentation , Anesthesia, Epidural/methods , Adolescent , Adult , Aged , Aged, 80 and over , Anesthesia, Epidural/adverse effects , Catheterization/adverse effects , Catheterization/instrumentation , Catheterization/methods , Humans , Medical Illustration , Middle Aged , Monitoring, Physiologic/methods , Nerve Block/methods , Pressure , Prospective Studies , Thoracic Vertebrae , Time Factors
6.
J Neurol Neurosurg Psychiatry ; 75(2): 320-2, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14742619

ABSTRACT

Repetitive transcranial magnetic stimulation (rTMS) has been reported to demonstrate slight effects in the treatment of depression. Hence, a novel bilateral versus unilateral and sham stimulation design was applied to further assess rTMS' antidepressant effects. Forty one medication free patients with major depression, admitted to a psychiatric unit specialising in affective disorders, were consecutively randomised into 3 groups. Group A1 (n = 12) received unilateral active stimulation consisting of high frequency (hf) rTMS over the left dorsolateral prefrontal cortex (LDLPC) and subsequent sham low frequency (lf) rTMS over the right dorsolateral prefrontal cortex (RDLPC). Group A2 (n = 13) received simultaneous bilateral active stimulation consisting of hf-rTMS over the LDLPC and lf-rTMS over the RDLPC. Group C (n = 13) received bilateral sham stimulation. Stimulation was performed on 10 consecutive workdays. All patients received antidepressant medication on the first day of stimulation, which was continued during and after the stimulation period. As no significant difference in antidepressant outcome between group A1 and A2 was found, the two groups were pooled. The time course of the outcome variables Hamilton depression rating scale (HDRS(21)) and Beck depression inventory (days 0, 7, 14, 28) by repeated measures analysis of variance revealed no significant group differences (in terms of a group by time interaction), whereas there was a significant effect of time on all three outcome variables in all groups. The results suggest that rTMS as an "add on" strategy, applied in a unilateral and a bilateral stimulation paradigm, does not exert an additional antidepressant effect.


Subject(s)
Depressive Disorder, Major/therapy , Electromagnetic Phenomena/instrumentation , Double-Blind Method , Equipment Design , Female , Humans , Male , Middle Aged , Prospective Studies , Skull , Treatment Failure
7.
Psychol Rep ; 92(3 Pt 1): 849-52, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12841455

ABSTRACT

Standardized assessment of a family's characteristics (conflict management, cohesion, etc.) is not used routinely, although these variables may play an important role in the course of psychological disorders in children. The present study investigated differences within the features of families of children with hyperkinetic and emotional disorders. Families of 20 boys diagnosed with Attention Deficit Hyperkinetic Disorder and 20 boys with Emotional Disorder (ages 6-12 years) by giving the Mannheim Parents Interview and the teacher's form of the Conners scale were included for evaluation and compared with a matched, healthy control group of 20 boys. Parents were asked to complete a form assessing the family's characteristics ("Familienklima-Testsystem"), including Cohesion, Expressiveness, Conflict Tendency, Individual Independence, Achievement Orientation, Intellectual-Cultural Orientation, Active-Recreational Orientation, Moral-Religious Emphasis, and Organization. Comparison of groups was made by the Kruskal-Wallis test and Mann-Whitney U test. There are significantly more conflicts in families whose children belong to the two disorder groups. Compared with a matched healthy control group, there is low Expressiveness, Independence, and Cultural and Active-Recreational Orientation in the Emotional Disorder group and a significant lack of Organization and Cohesion in the Attention Deficit Hyperkinetic Disorder group. Altogether there seems to be a significant association of Attention Deficit Hyperkinetic Disorder symptoms with the family's Cohesion and Organization. One implication is that therapists focus their efforts not only on the children with disorders but also on their families.


Subject(s)
Affective Symptoms/psychology , Attention Deficit Disorder with Hyperactivity/psychology , Family Relations , Interview, Psychological , Parenting/psychology , Personality Assessment/statistics & numerical data , Affective Symptoms/diagnosis , Affective Symptoms/therapy , Attention Deficit Disorder with Hyperactivity/diagnosis , Child , Conflict, Psychological , Family Therapy , Humans , Male , Psychometrics/statistics & numerical data , Reference Values
8.
Anaesthesia ; 57(8): 768-72, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12133089

ABSTRACT

Fifty patients scheduled for surgery under lumbar epidural anaesthesia were included in a study to evaluate the possibility of localising the epidural space solely by means of an acoustic signal. With an experimental set-up, the pressure generated during the epidural puncture procedure was translated into a corresponding acoustic signal. One anaesthetist held the epidural needle with both hands and detected the epidural space by means of this acoustic signal. At the same time, a second anaesthetist applied the loss of resistance technique and functioned as control. In all patients the epidural space was located with the acoustic signal. This was confirmed by conventional loss of resistance in 49 (98%) of the patients; in one patient (2%) it was not. We conclude that it is possible to locate the epidural space using an acoustic signal alone.


Subject(s)
Acoustics , Anesthesia, Epidural/instrumentation , Epidural Space/anatomy & histology , Aged , Female , Humans , Male , Middle Aged , Punctures/instrumentation , Transducers, Pressure
9.
J Mol Biol ; 308(1): 27-38, 2001 Apr 20.
Article in English | MEDLINE | ID: mdl-11302704

ABSTRACT

Reversible histone acetylation changes the chromatin structure and can modulate gene transcription. Mammalian histone deacetylase 1 (HDAC1) is a nuclear protein that belongs to a growing family of evolutionarily conserved enzymes catalysing the removal of acetyl residues from core histones and other proteins. Previously, we have identified murine HDAC1 as a growth factor-inducible protein in murine T-cells. Here, we characterise the molecular function of mouse HDAC1 in more detail. Co-immunoprecipitation experiments with epitope-tagged HDAC1 protein reveal the association with endogenous HDAC1 enzyme. We show that HDAC1 can homo-oligomerise and that this interaction is dependent on the N-terminal HDAC association domain of the protein. Furthermore, the same HDAC1 domain is also necessary for in vitro binding of HDAC2 and HDAC3, association with RbAp48 and for catalytic activity of the enzyme. A lysine-rich sequence within the carboxy terminus of HDAC1 is crucial for nuclear localisation of the enzyme. We identify a C-terminal nuclear localisation domain, which is sufficient for the transport of HDAC1 and of reporter fusion proteins into the nucleus. Alternatively, HDAC1 can be shuttled into the nucleus by association with another HDAC1 molecule via its N-terminal HDAC association domain. Our results define two domains, which are essential for the oligomerisation and nuclear localisation of mouse HDAC1.


Subject(s)
Histone Deacetylases/chemistry , Histone Deacetylases/metabolism , Transcription Factors , Active Transport, Cell Nucleus , Amino Acid Motifs , Amino Acid Sequence , Animals , Carrier Proteins/metabolism , Cell Line , Cell Nucleus/metabolism , Conserved Sequence/genetics , Epitopes/genetics , Epitopes/metabolism , Hemagglutinins, Viral/genetics , Hemagglutinins, Viral/metabolism , Histone Deacetylase 1 , Histone Deacetylases/genetics , Humans , Lysine/genetics , Lysine/metabolism , Mice , Molecular Sequence Data , Mutation/genetics , Nuclear Localization Signals , Nuclear Proteins/metabolism , Protein Binding , Protein Structure, Quaternary , Protein Structure, Tertiary , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/metabolism , Repressor Proteins/metabolism , Retinoblastoma-Binding Protein 4 , Sequence Alignment , Sin3 Histone Deacetylase and Corepressor Complex
10.
J Biol Chem ; 275(52): 40961-6, 2000 Dec 29.
Article in English | MEDLINE | ID: mdl-11024051

ABSTRACT

SDS3 (suppressor of defective silencing 3) was originally identified in a screen for mutations that cause increased silencing of a crippled HMR silencer in a rap1 mutant background. In addition, sds3 mutants have phenotypes very similar to those seen in sin3 and rpd3 mutants, suggesting that it functions in the same genetic pathway. In this manuscript we demonstrate that Sds3p is an integral subunit of a previously identified high molecular weight Rpd3p.Sin3p containing yeast histone deacetylase complex. By analyzing an sds3Delta strain we show that, in the absence of Sds3p, Sin3p can be chromatographically separated from Rpd3p, indicating that Sds3p promotes the integrity of the complex. Moreover, the remaining Rpd3p complex in the sds3Delta strain had little or no histone deacetylase activity. Thus, Sds3p plays important roles in the integrity and catalytic activity of the Rpd3p.Sin3p complex.


Subject(s)
Fungal Proteins/physiology , Gene Silencing , Histone Deacetylases/metabolism , Repressor Proteins , Saccharomyces cerevisiae Proteins , Transcription Factors/physiology
11.
Acta Neuropathol ; 100(2): 205-12, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10963369

ABSTRACT

Synapse loss is crucially involved in cognitive decline in Alzheimer's disease (AD). This study was performed to investigate the distribution and density of chromogranin B-like immunoreactivity in the hippocampus of control compared to AD brain. Chromogranin B is a large precursor molecule found in large dense-core vesicles. For immunocytochemistry we used an antiserum raised against a synthetic peptide (PE- 11) present in the chromogranin B molecule. Chromogranin B-like immunoreactivity was concentrated in the terminal field of mossy fibers, the inner molecular layer of the dentate gyrus and in layer II of the entorhinal cortex. In AD, chromogranin B was detected in neuritic plaques. The density of chromogranin B-like immunoreactivity was significantly reduced in the inner molecular layer of the dentate gyrus and in layers II, III and V of the entorhinal cortex in AD brains. The present study demonstrates that chromogranin B is a marker for human hippocampal pathways. It is particularly suitable for studying nerve fibers terminating at the inner molecular layer of the dentate gyrus. It is present in neuritic plaques, and its density is reduced in a layer-specific manner.


Subject(s)
Alzheimer Disease/metabolism , Chromogranins/metabolism , Hippocampus/metabolism , Aged , Aged, 80 and over , Chromogranin B , Female , Humans , Immunohistochemistry , Male , Reference Values , Tissue Distribution
12.
Biochemistry ; 39(7): 1683-92, 2000 Feb 22.
Article in English | MEDLINE | ID: mdl-10677216

ABSTRACT

Posttranslational core histone acetylation is established and maintained by histone acetyltransferases and deacetylases. Both have been identified as important transcriptional regulators in various eukaryotic systems. In contrast to nonplant systems where only RPD3-related histone deacetylases (HD) have been characterized so far, maize embryos contain three unrelated families of deacetylases (HD1A, HD1B, and HD2). Purification, cDNA cloning, and immunological studies identified the two maize histone deacetylase HD1B forms as close homologues of the RPD3-type deacetylase HDAC1. Unlike the other maize deacetylases, HD1A and nucleolar HD2, HD1B copurified as a complex with a protein related to the retinoblastoma-associated protein, Rbap46. Two HD1B mRNA species could be detected on RNA blots, encoding proteins of 58 kDa (HD1B-I) and 51 kDa (HD1B-II). HD1B-I (zmRpd3) represents the major enzyme form as judged from RNA and immunoblots. Levels of expression of HD1B-I and -II mRNA differ during early embryo germination; HD1B-I mRNA and protein are present during the entire germination pathway, even in the quiescent embryo, whereas HD1B-II expression starts when meristematic cells enter S-phase of the cell cycle. In line with previous results, HD1B exists as soluble and chromatin-bound enzyme forms. In vivo treatment of meristematic tissue with the deacetylase inhibitor HC toxin does not affect the expression of the three maize histone deacetylases, whereas it causes downregulation of histone acetyltransferase B.


Subject(s)
Histone Deacetylases/chemistry , Plant Proteins/chemistry , Transcription Factors/chemistry , Zea mays/enzymology , Amino Acid Sequence , DNA, Complementary/isolation & purification , Enzyme Induction/drug effects , Enzyme Induction/genetics , Germination/drug effects , Germination/genetics , Histone Deacetylases/biosynthesis , Histone Deacetylases/genetics , Histone Deacetylases/isolation & purification , Humans , Molecular Sequence Data , Peptide Fragments/toxicity , Plant Proteins/genetics , Plant Proteins/isolation & purification , Plant Proteins/metabolism , RNA, Messenger/metabolism , Seeds/enzymology , Seeds/growth & development , Tetanus Toxin/toxicity , Transcription Factors/genetics , Transcription Factors/isolation & purification , Transcription Factors/metabolism , Zea mays/growth & development
13.
Trends Biochem Sci ; 25(1): 15-9, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10637607

ABSTRACT

Histone acetylation is closely linked to gene transcription. The identification of histone acetyltransferases (HATs) and the large multiprotein complexes in which they reside has yielded important insights into how these enzymes regulate transcription. The demonstration that HAT complexes interact with sequence-specific activator proteins illustrates how these complexes target specific genes. In addition to histones, some HATs can acetylate non-histone proteins suggesting multiple roles for these enzymes.


Subject(s)
Acetyltransferases/genetics , Acetyltransferases/metabolism , Saccharomyces cerevisiae Proteins , Transcription, Genetic , Animals , Gene Expression Regulation, Fungal , Histone Acetyltransferases , Humans , Substrate Specificity , Trans-Activators/metabolism , Yeasts/genetics , Yeasts/metabolism
14.
Biochemistry ; 38(21): 6769-73, 1999 May 25.
Article in English | MEDLINE | ID: mdl-10346897

ABSTRACT

Enzymes involved in histone acetylation have been identified as important transcriptional regulators. Maize embryos contain three histone deacetylase families: RPD3-type deacetylases (HD1-B), nucleolar phosphoproteins of the HD2 family, and a third form unrelated to RPD3 and HD2 (HD1-A). Here we first report on the specificity of deacetylases for core histones, acetylated histone H4 subspecies, and acetylated H4-lysine residues. HD1-A, HD1-B, and HD2 deacetylate all four core histones, although with different specificity. However, experiments with histones from different sources (hyperacetylated MELC and chicken histones) using antibodies specific for individually acetylated H4-lysine sites indicate that the enzymes recognize highly distinct acetylation patterns. Only RPD3-type deacetylase HD1-B is able to deacetylate the specific H4 di-acetylation pattern (position 12 and 5) introduced by the purified cytoplasmic histone acetyltransferase B after incubation with pure nonacetylated H4 subspecies. HD1-A and HD2 exist as phosphorylated forms. Dephosphorylation has dramatic, but opposite effects; whereas HD2 loses enzymatic activity upon dephosphorylation, HD1-A is activated with a change of specificity against acetylated H4 subspecies. The data suggest that different types of deacetylases interact with different and highly specific acetylation patterns on nucleosomes.


Subject(s)
Histone Deacetylases/chemistry , Histone Deacetylases/metabolism , Zea mays/enzymology , Acetylation , Animals , Binding Sites , Chickens , Histone Deacetylases/blood , Histones/blood , Histones/chemistry , Histones/metabolism , Isoenzymes/blood , Isoenzymes/chemistry , Isoenzymes/metabolism , Mice , Phosphorylation , Reticulocytes/enzymology , Substrate Specificity , Tumor Cells, Cultured
15.
Crit Rev Eukaryot Gene Expr ; 9(3-4): 231-43, 1999.
Article in English | MEDLINE | ID: mdl-10651240

ABSTRACT

Early studies revealing the relationship between the state of histone acetylation and gene transcription were largely indirect. Increasing information regarding the enzymes that catalyze transcription linked acetylation is beginning to clarify this issue. This review attempts to relate previous data regarding the distribution of histone acetylation within different chromatin regions with recent data regarding the substrate specificity, subunit composition, and recruitment of the known histone acetyltransferase complexes.


Subject(s)
Acetyltransferases/genetics , Cell Nucleus/genetics , Histones/genetics , Saccharomyces cerevisiae Proteins , Transcription, Genetic , Acetyltransferases/metabolism , Animals , Cell Nucleus/enzymology , Histone Acetyltransferases , Histones/metabolism , Humans
16.
Methods ; 15(4): 323-31, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9740720

ABSTRACT

Specific lysine residues in the N-terminal extensions of core histones can be posttranslationally modified by acetylation of the epsilon-amino group. The dynamic equilibrium of core histone acetylation is established and maintained by histone acetyltransferases and deacetylases. Both enzymes exist as multiple enzyme forms. Histone acetyltransferases and deacetylases have recently been identified as transcriptional regulators as well as nucleolar phosphoproteins, and have therefore attracted considerable research interest. Analysis of the functional significance of histone deacetylases for nuclear processes in certain cases demands the separation and biochemical analysis of different members of the histone deacetylase families. We have characterized three different histones deacetylases in maize embryos and subsequently purified these enzymes to homogeneity. Here we describe methods for extraction, enzymatic assay, chromatographic and electrophoretic separation, and purification of deacetylases. A novel one-step procedure for large-scale preparation of individual histones and their acetylated isoforms for the analysis of substrate and site specificity of the enzymes is presented.


Subject(s)
Biochemistry/methods , Chromatography, Liquid/methods , Electrophoresis, Polyacrylamide Gel/methods , Histone Deacetylases/isolation & purification , Histone Deacetylases/metabolism , Binding Sites , Histone Deacetylases/chemistry , Histones/isolation & purification , Histones/metabolism , Isoelectric Focusing , Substrate Specificity
17.
J Matern Fetal Investig ; 8(4): 172-177, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9892751

ABSTRACT

> Objective: For more than 20 years, vibroacoustic stimulation testing (VAST) using an artificial larynx has been used worldwide when fetal heart rate monitoring produced patterns with absent or very low variability. In addition to the artificial larynx many other appliances have been used to stimulate a seemingly dormant fetus, but these have rarely been evaluated properly. In this study we tried to evaluate the use of standard mechanical wind-up alarm clocks for VAST. Methods: VAST with an alarm clock was performed successfully in 80 women with normal pregnancies from 36 weeks to term. It was tested by placing the alarm clock on the maternal abdomen just above the fetal head or on the controlateral side of the maternal abdomen to see whether position made any difference and whether coupling with ultrasound gel applied between the alarm clock and the maternal abdomen would affect the degree of fetal reaction to VAST as expressed in heart rate acceleration. Similarly, the effect of the alarm clock VAST on subjective and objective fetal movement patterns as registered by kineto-cardiotocotraphy (K-CTG) in addition to heart rate patterns was investigated. Results: All fetuses showed heart rate acceleration, an increase in heart variability, and increase in movement patterns in the 6 min after the application of alarm clock VAST. No statistically significant difference was found which would favor a particular placement of the alarm clock on the maternal abdomen or the use of ultrasound coupling gel. When K-CTG was performed, patient-perceived fetal movements as expressed with an event marker showed agreement with the machine-registered movements only when patients could see the tracing during registration and no accordance when the K-CTG was turned toward the wall during registation. Conclusion: In keeping with the ALARA principle a conventional wind-up alarm clock appears to be an inexpensive and effective alternative to the electrolarynx.

18.
Gynakol Geburtshilfliche Rundsch ; 37(3): 119-29, 1997.
Article in German | MEDLINE | ID: mdl-9483870

ABSTRACT

From 23 weeks of gestation some and from 28 weeks all healthy fetuses are capable of reacting to sound stimulation. The intrauterine acoustic environment is dominated by maternal sounds--heartbeat, breathing, the mother's voice, borborygmi and sounds caused by body movements. Background noise is never below 28 dB and can rise to 84 dB when the mother is singing. Noises that are meant to reach the fetus must be louder than the background noise and must be of low frequency as high frequency sounds are damped by maternal tissue. Vibroacoustic stimulation tests (VAST) have become popular in pregnancy surveillance over the last 20 years, mostly using an artificial larynx. Advantages and problems of the various VAST protocols in fetal monitoring are discussed in the light of animal experiments and clinical studies. Health legislation laws in most countries forbid pregnant women to work in surroundings with a high noise level (80 dB continuous noise and/or rapid impulse noise changes of 40 dB). Whereas regulations for pregnant women are easy to enforce in industry, pregnant women employed in discos or performing as musicians spend most of their working day exposed to noise impact higher than the recommended limit.


Subject(s)
Auditory Perception/physiology , Embryonic and Fetal Development/physiology , Noise, Occupational/adverse effects , Prenatal Exposure Delayed Effects , Animals , Female , Fetal Movement/physiology , Gestational Age , Hearing Loss, Noise-Induced/physiopathology , Hearing Loss, Noise-Induced/prevention & control , Humans , Infant, Newborn , Noise, Occupational/prevention & control , Pregnancy
19.
Biochim Biophys Acta ; 1296(2): 181-8, 1996 Sep 05.
Article in English | MEDLINE | ID: mdl-8814225

ABSTRACT

The enzymatic equilibrium of reversible core histone acetylation is maintained by two enzyme activities, histone acetyltransferase and histone deacetylase (HD). These enzyme activities exist as multiple enzyme forms. The present report describes methods to extract different HD-forms from three organisms, germinating maize embryos, the myxomycete Physarum polycephalum, and chicken red blood cells; it provides data on the chromatographic separation and partial purification of HD-forms. In germinating maize embryos three HDs (HD1-A, HD1-B, HD2) can be discriminated; HD1-A, HD1-B, and HD2 were characterized in terms of their dependence on pH, temperature and various ions, as well as kinetic parameters (Km for core histones) and inhibition by various compounds. The same parameters were investigated for the corresponding enzymes of Physarum polycephalum, and mature and immature chicken erythrocytes. Based on these results, optimum assay conditions were established for the different enzyme forms. The kinetic data revealed that the maize histone deacetylase HD1-B peak after partial purification by Q-Sepharose chromatography was heterogeneous and consisted of two histone binding sites that differed significantly in their affinity for purified core histones. Optimized affinity chromatography on poly-Lysine Agarose indeed showed that the former defined deacetylase HD1-B can be separated clearly into two individual HD enzyme forms. The high multiplicity of histone deacetylases underlines the importance of these enzymes for the complex regulation of core histone acetylation.


Subject(s)
Chickens/blood , Fungal Proteins/metabolism , Histone Deacetylases/metabolism , Physarum polycephalum/enzymology , Plant Proteins/metabolism , Zea mays/enzymology , Acetylation , Animals , Chromatin/metabolism , Chromatography, Ion Exchange , Erythrocytes/enzymology , Histone Deacetylases/isolation & purification , Seeds/enzymology , Species Specificity , Zea mays/embryology
20.
FEBS Lett ; 386(1): 75-81, 1996 May 13.
Article in English | MEDLINE | ID: mdl-8635608

ABSTRACT

From a soluble cellular fraction of maize embryos we purified to apparent homogeneity a cytoplasmic histone acetyltransferase, which matches all criteria for a B-type enzyme. Using 8 chromatographic steps, we achieved a 6700-fold purification of an enzymatically active protein with a molecular weight of approximately 90 kDa. Under denaturing conditions the protein split into 2 components which migrated at 45 and 50 kDa in SDS-PAGE, suggesting that the native enzyme is a heterodimer. The purified enzyme was characterized in terms of physicochemical and kinetic properties, and substrate specificity. It was specific for histone H4, leading to acetylation of non-acetylated H4 subspecies into the di-acetylated state in vitro. Its activity was coincident with the intensity of DNA replication in meristematic cells during embryo germination. We established an electrophoretic system under non-denaturing conditions for detection of enzyme activity within the gel matrix; in combination with second dimension SDS-PAGE the procedure allowed the unambiguous identification of histone acetyltransferase, even in crude enzyme preparations.


Subject(s)
Acetyltransferases/chemistry , Saccharomyces cerevisiae Proteins , Zea mays/enzymology , Acetylation , Acetyltransferases/isolation & purification , Acetyltransferases/metabolism , Chemical Fractionation , Chemical Phenomena , Chemistry, Physical , Chromatography/methods , Cytoplasm/enzymology , Electrophoresis, Polyacrylamide Gel/methods , Histone Acetyltransferases , Histones/metabolism , Kinetics , Protein Denaturation , Seeds/enzymology , Solubility , Substrate Specificity , Zea mays/embryology
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