Biomedical subjects

B Berger

Publications and source records attributed to B Berger.

At least 19 recordsLinked to original sources

PubMed2003

Effects of media, fertilization technique, extender, straw volume, and sperm to egg ratio on hatchability of cyprinid embryos, using cryopreserved semen.

To enable cryopreservation of fish semen to become an efficient, routine technique, much more detailed information is required. Therefore, the present study was conducted to investigate various fertilization techniques and media, straw volumes as well as optimal semen volume for cryopreservation. The bleak (Chalcalburnus chalcalburnus) was used as the main model for investigation. Using frozen-thawed semen the fertilization rate was similar up to the morula stage, independent of the fertilization technique. Thereafter, in egg batches fertilized using the wet technique most embryo development stopped. In egg batches fertilized using the dry technique, embryonic development proceeded normally. For cryopreserved semen full activation of sperm motility was obtained at ratios of fertilization media (hatchery water and all tested types of saline solutions) to semen of 10:1. Sperm motility rate was much higher in the saline solutions than in water. In contrast hatching rates were higher when water was used as fertilization medium. Therefore, the requirements necessary for optimal sperm motility and optimal sperm-egg contact were different and so for these parameters optimal levels could not be achieved. When adjusting the freezing and thawing conditions 0.5ml straws as well as larger straws (1.2ml) proved suitable for cryopreservation of cyprinid semen. The highest fertilization rates were obtained with sperm to egg ratios of (1.3-2.5) x 10(6):1 and were 77-92% of fresh semen control. This was also similar for Ch. nasus, R. meidingerii, B. barbatus and C. carpio and suggests that the cryopreservation requirements of spermatozoa are not species specific.

Animals↗

PubMed2003

Population genetic comparisons of three X-chromosomal STRs.

The X-chromosomal short tandem repeats (STRs) DXS6800, DXS101 and DXS8377 were analysed in male and female population samples from Germany and Austria using a PCR multiplex approach. We investigated 135 family trios from Innsbruck (Austria) and surrounding areas and 50 families and further male and female samples from Ulm (Germany) and surrounding areas. The comparisons of the allele frequencies gave similar distributions for Innsbruck and Ulm although minor variations were found for some alleles. Additionally, some differences were found when comparing the allele frequencies of the male and female samples independently. The forensic efficiency values demonstrate that especially DXS101 and DXS8377 are highly informative markers for kinship analysis and deficiency cases. Based on the investigated meiotic events no new mutations were detected.

Adolescent↗

PubMed2002

Rare failures in the amelogenin sex test.

Determination of sex using the amelogenin sex test is well established in the forensic field especially for casework and DNA databasing purposes. The sex test is part of commercially available PCR kits. Among 29,432 phenotypic male individuals stored in the Austrian National DNA database, 6 individuals were found to lack the amelogenin Y-specific PCR product which was confirmed using alternative amelogenin primers. The amplification of eight Y-chromosomal STR markers resulted in full profiles in five out of the six samples, one sample failed to amplify Y-STRs at all. The amplification of a fragment of the SRY gene gave positive results in all six samples, confirming the male phenotype of the individuals. The observed failure rate of the amelogenin sex test was 0.018% in this study.

Amelogenin↗

PubMed2001

BETAWRAP: successful prediction of parallel beta -helices from primary sequence reveals an association with many microbial pathogens.

The amino acid sequence rules that specify beta-sheet structure in proteins remain obscure. A subclass of beta-sheet proteins, parallel beta-helices, represent a processive folding of the chain into an elongated topologically simpler fold than globular beta-sheets. In this paper, we present a computational approach that predicts the right-handed parallel beta-helix supersecondary structural motif in primary amino acid sequences by using beta-strand interactions learned from non-beta-helix structures. A program called BETAWRAP (http://theory.lcs.mit.edu/betawrap) implements this method and recognizes each of the seven known parallel beta-helix families, when trained on the known parallel beta-helices from outside that family. BETAWRAP identifies 2,448 sequences among 595,890 screened from the National Center for Biotechnology Information (NCBI; http://www.ncbi.nlm.nih.gov/) nonredundant protein database as likely parallel beta-helices. It identifies surprisingly many bacterial and fungal protein sequences that play a role in human infectious disease; these include toxins, virulence factors, adhesins, and surface proteins of Chlamydia, Helicobacteria, Bordetella, Leishmania, Borrelia, Rickettsia, Neisseria, and Bacillus anthracis. Also unexpected was the rarity of the parallel beta-helix fold and its predicted sequences among higher eukaryotes. The computational method introduced here can be called a three-dimensional dynamic profile method because it generates interstrand pairwise correlations from a processive sequence wrap. Such methods may be applicable to recognizing other beta structures for which strand topology and profiles of residue accessibility are well conserved.

Bacteria↗

PubMed2001

Early development of neuronal activity in the primate hippocampus in utero.

Morphological studies suggest that the primate hippocampus develops extensively before birth, but little is known about its functional development. Patch-clamp recordings of hippocampal neurons and reconstruction of biocytin-filled pyramidal cells were performed in slices of macaque cynomolgus fetuses delivered by cesarean section. We found that during the second half of gestation, axons and dendrites of pyramidal cells grow intensively by hundreds of micrometers per day to attain a high level of maturity near term. Synaptic currents appear around midgestation and are correlated with the level of morphological differentiation of pyramidal cells: the first synapses are GABAergic, and their emergence correlates with the growth of apical dendrite into stratum radiatum. A later occurrence of glutamatergic synaptic currents correlates with a further differentiation of the axodendritic tree and the appearance of spines. Relying on the number of dendritic spines, we estimated that hundreds of new glutamatergic synapses are established every day on a pyramidal neuron during the last third of gestation. Most of the synaptic activity is synchronized in spontaneous slow ( approximately 0.1 Hz) network oscillations reminiscent of the giant depolarizing potentials in neonatal rodents. Epileptiform discharges can be evoked by the GABA(A) receptor antagonist bicuculline by the last third of gestation, and postsynaptic GABA(B) receptors contribute to the termination of epileptiform discharges. Comparing the results obtained in primates and rodents, we conclude that the template of early hippocampal network development is conserved across the mammalian evolution but that it is shifted toward fetal life in primate.

Animals↗

PubMed2001

Human and monkey fetal brain development of the supramammillary-hippocampal projections: a system involved in the regulation of theta activity.

The supramammillary (SUM)-hippocampal pathway plays a central role in the regulation of theta rhythm frequency. We followed its prenatal development in eight Cynomolgus monkeys (Macaca fascicularis) from embryonic day E88 to postnatal day 12 (term 165 days) and in eight human fetuses from 17.5 to 40 gestational weeks, relying on neurochemical criteria established in the adult (Nitsch and Leranth [1993] Neuroscience 55:797-812). We found that 1) SUM afferents reached the dentate juxtagranular and CA2 pyramidal cell layers at midgestation in human fetuses, earlier than in monkeys (two-thirds of gestation [E109]). They co-expressed calretinin, substance P, and acetylcholinesterase but not gamma-aminobutyric acid (GABA) or glutamic acid decarboxylase (GAD); 2) the presumed parent neurons in the monkey SUM expressed calretinin or both calretinin and substance P; 3) most of them were surrounded by GAD-containing terminals that might correspond to the septo-SUM feedback pathway (Leranth et al. [1999] Neuroscience 88:701); and 4) in addition, a large band of calretinin-labeled terminals that did not co-express substance P, GAD, or acetylcholinesterase was present in the deepest one-third of the dentate molecular layer in both the Cynomolgus monkey and human fetuses. It persisted in the adult monkey but not in adult human hippocampus; it remains questionable whether it originates in the SUM. In conclusion, the early ingrowth of the excitatory SUM-hippocampal system in human and non-human primates may contribute to the prenatal activity-dependent development of the hippocampal formation. The possibility and the functional importance of an in utero generation of hippocampal theta-like activity should also be considered.

Afferent Pathways↗

PubMed2001

Pesticide residues in products of plant origin in the European Union. Sampling strategy and results from the co-ordinated EU monitoring programmes in 1996 and 1997.

The results of a co-ordinated monitoring programme for pesticide residues in the European Union and Norway carried out in 1996 and 1997 are presented. The aim of this programme is to work towards a system, which makes it possible to estimate actual dietary pesticide intake for the population of the European Union. Based on a statistically dérived sampling plan and within the limited number of pesticides/commodities analysed, the most critical pesticides (benomyl group and dithiocarbamates) and commodities (mandarine and lettuce) were identified. In case of detected non-compliances, repeated sampling and, if necessary, enforcement actions are to be taken by national authorities. The programme will be continued in the next years.

Benomyl↗

PubMed2001

Transposase and cointegrase: specialized transposition proteins of the bacterial insertion sequence IS21 and related elements.

The bacterial insertion sequence IS21 shares with many insertion sequences a two-step, reactive junction transposition pathway, for which a model is presented in this review: a reactive junction with abutted inverted repeats is first formed and subsequently integrated into the target DNA. The reactive junction occurs in IS21-IS21 tandems and IS21 minicircles. In addition, IS21 shows a unique specialization of transposition functions. By alternative translation initiation, the transposase gene codes for two products: the transposase, capable of promoting both steps of the reactive junction pathway, and the cointegrase, which only promotes the integration of reactive junctions but with higher efficiency. This review also includes a survey of the IS21 family and speculates on the possibility that other members present a similar transpositional specialization.

Amino Acid Sequence↗

PubMed2001

Population genetics of ten STR loci (AmpFlSTR SGM plus) in Austria.

A population study on the ten short tandem repeat (STR) loci D3S1358, VWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01 and FGA was performed on 204 unrelated Austrian Caucasians. The DNA was amplified by multiplex PCR using the AmpF/STR SGM plus kit. All loci met Hardy-Weinberg expectations. The combined power of exclusion for the ten STR loci was 0.999976. The results show that these loci are very useful for forensic purposes.

Austria↗

PubMed2001

Colocalization of beta 1,4galactosyltransferase with mannose 6-phosphate receptor in monensin-induced TGN-derived structures.

Previously, we demonstrated that beta 1,4galactosyltransferase (gal-T1) reversibly segregates from alpha 2,6sialyltransferase (ST6Gal) to swollen vesicles after monensin treatment of the cells. To further explore this phenomenon, we investigated the response to monensin of various Golgi proteins. Within 30 min of monensin treatment, gal-T1 moved from the Golgi apparatus, as defined by localization of giantin, to swollen vesicles whereas ST6Gal, alpha 2,3(N)sialyltransferase, mannosidase II, and N-acetylgalactosaminyltransferase 2 remained associated with the Golgi apparatus. Stably transfected CHO cells exhibited a similar phenomenon of monensin-induced displacement of recombinant gal-T1 to swollen vesicles while recombinant ST6Gal remained colocalized with endogenously expressed giantin. Gal-T1 and the cation-insensitive mannose 6-phosphate receptor colocalized in swollen vesicles as observed at both light and electron microscopic levels. When monensin was replaced by chloroquine, gal-T1 remained arrested in swollen vesicles. Brefeldin A treatment known to cause relocation of Golgi-associated gal-T1 to the endoplasmic reticulum had no effect on gal-T1 trapped in swollen vesicles. This evidence suggests that monensin blocks gal-T1 trafficking in post-Golgi structures and argues against swelling of gal-T1-containing trans Golgi cisternae as previously assumed.

Animals↗

PubMed2001

Spectroscopic characterization of metallothionein from the terrestrial snail, Helix pomatia.

The Cd-sequestering metallothionein (MT) isoform isolated from the midgut gland of Roman snails exposed to Cd supplements in the feed was characterized by compositional and spectroscopic analysis. The preparations contained nearly 5 mol of Cd, small amounts of Cu and about 1 mol of Zn per chain mass of 6620 Da, in numerical agreement with the apoprotein's measured capacity of firmly binding a maximum of 6 equivalents of Cd per molecule. As with other Cd-containing MTs the occurrence of a prominent Cd-mercaptide-specific shoulder at 250 nm in its absorption spectrum showed that Cd is complexed in tetrahedral symmetry by the cysteine residues of the protein, and the multiphasic ellipticity profile in the CD spectrum revealed that these complexes are joined to form one or more oligonuclear Cd-mercapto clusters. Both spectral features vanished with the removal of the metal but were reconstituted to maximum amplitudes by readdition of Cd to the metal-free apoprotein, provided precautions were taken to prevent air oxidation of the latter. Quantitative analysis of snail MT reconstituted with Cd established that the 18 cysteine side chains bind the metal in a 3-to-1 ratio; spectroscopic studies on fractionally restored forms demonstrated that the six Cd ions were bound to the apoprotein molecule in succession in two sets of three Cd ions each. Thus, one can infer from the observed stoichiometry and the coordinating preferences of Cd that this gastropod MT, like the Cd-bearing MTs of marine crustaceans, harboured the metal in two separate cyclically constructed Cd3Cys9 clusters. The snail clusters differed, however, from other MTs in their response to acidification. Their protolytic dissociation proceeded through two separate protonation steps with the manifestation of spectroscopically distinguishable intermediate forms. Thus, this snail isoform displays in its metal composition and its chemical and spectroscopic features both similarities and differences to other animal kingdom MTs. Its properties suggest that it serves an important role in the protection of the terrestrial gastropod from Cd.

Animals↗

PubMed2001

[Opisthorchiasis simulating a malignancy].

We report on 2 patients from Siberia suffering from an infection with the parasite Opisthorchis felineus. The unusual course of their disease pretended in case 1 an eosinophilic leukemia and in case 2 a malignoma of the gallbladder. The Opisthorchiasis is endemic in large areas of Asia and Russia. Humans acquire the infection by eating raw fresh-water fish. Symptoms are nonspecific, but detection of eosinophilia in travellers or residents of endemic areas should induce analysis for specific antibodies against Opisthorchis species. Opisthorchiasis is known to be a precursor of cholangiocarcinoma. Malignoma which was initially suspected could be excluded in both cases and the patients were cured by oral administration of Praziquantel, 40-75 mg/kg body weight for 1 day in 3 divided doses.

Adult↗

PubMed2001

When autosomal short tandem repeats fail: optimized primer and reaction design for Y-chromosome short tandem repeat analysis in forensic casework.

Y-chromosomal short tandem repeats (Y-STRs) are useful forensic DNA markers in investigation of sexual assault cases when a mixture of male and female DNA (e.g., in vaginal swabs) is present in a sample, especially when DNA of the male contributor is present only in very small amount compared to the DNA of the female victim. With autosomal STR analysis of male and female DNA, male DNA in mixtures can usually be detected and correctly interpreted only when it exceeds 5%. However, the amplification of some Y-STRs is known to result in polymerase chain reaction (PCR) products that are not associated with the Y-chromosome, but derive from the X-chromosome and/or autosomal regions. This can cause problems in the interpretation of results, particularly when female DNA is present in excess. Consequently, more specific and sensitive Y-STR primers and PCR conditions are needed. This paper presents two casework examples in which sensitive Y-STR multiplexes (with the addition of PCR enhancer) were successfully used in the analysis of mixtures of male and female DNA, the male component not interpretable by standard autosomal STR typing.

Adolescent↗

PubMed2000

Cryopreservation of spermatozoa in cyprinid fishes.

The present study investigated semen cryopreservation in cyprinid fish using computer-assisted sperm motility analysis for viability control. Spermatozoa of the bleak, Chalcalbumus chalcoides, were used as a basic model to describe the toxic and cryoprotective effects of internal and external cryoprotectants, their most effective concentrations and combinations, the freezing and thawing conditions, and the effects of equilibration. We also used these data to develop a cryopreservation protocol for Barbus barbus, Chondrostoma nasus, Ctenopharyngodon idella, Cyprinus cario, Hypohtalmichthys molitrix, Leuciscus cephalus, Rutilus meidingerii, and Vimba vimba. For all investigated species the optimal extender composition was a buffered physiological sperm motility-inhibiting saline solution containing 10% DMSO and 0.5% glycin. The optimal sperm equilibration period in the extender was < or = 5 min. Freezing was performed in an insulated box in liquid nitrogen vapor and it was optimal at 4 to 5 cm above the surface of the liquid, depending on the species. Thawing was optimal in a 25 degrees C water bath whereby the thawing time ranged depending on species from 15 to 45 sec. This cryopreservation protocol resulted in frozen-thawed semen with 35 to 65% motile and 5 to 25% locally motile spermatozoa depending on the quality of fresh semen.

Animals↗

PubMed2000

"Local rules" theory applied to polyomavirus polymorphic capsid assemblies.

The papovaviruses are nonenveloped dsDNA viruses whose capsids are characterized by a non-quasi-equivalent bonding pattern in which 72 pentameric capsomeres occupy positions having either five or six neighboring capsomeres. The local rules theory of Berger et al. (1994, Proc. Natl. Acad. Sci. USA, 91, 7732-7736), previously developed to explain aspects of icosahedral capsid assembly, has been applied to the papovavirus geometry. Local rules describe capsid symmetry patterns in terms of the local interactions of assembly units, such as coat proteins or capsomeres. Polymorphic assemblies, including T = 1 icosahedral, dodecahedral, spiral, and tubular structures of the polyomavirus VP1 protein, can be induced by specific mutations or changes in the solvent conditions during in vitro assembly of the recombinant coat protein. Local rules models were developed to model the wild-type capsid and several polymorphic assemblies. Some assemblies corresponded to structures modeled by small deviations from wild-type local rules. We conclude that aspects of polyomavirus assembly are consistent with local rules models, although they do not explain all polymorphisms. These results may provide insights into the nature of papovavirus assembly, constraints on assembly pathways, and strategies for disrupting assembly.

Capsid↗

PubMed2000

Prisoners of liberation: a psychoanalytic perspective on disenchantment and burnout among career women lawyers.

Using a psychoanalytic perspective, this article addresses the roots and treatment of disillusionment and incipient burnout in female corporate lawyers. It suggests that one of the primary issues that needs to be addressed in therapy with this group is the tendency to be self-punishing, a characteristic that often may be traced back to insensitive parenting. This formulation, combined with the penchant of law firms to regard as "good and expected" the inclination of their workers (especially women) to work without respite and with little regard for their own needs, places individuals at high risk for burnout. A case example is used to illustrate this phenomenon. It is concluded that whereas psychoanalytic treatment greatly may help overstressed professionals, society at large must address the values that foster the attitude of high career achievement at any cost.

Adult↗

PubMed2000

Concordance of the toxicity of pharmaceuticals in humans and in animals.

This report summarizes the results of a multinational pharmaceutical company survey and the outcome of an International Life Sciences Institute (ILSI) Workshop (April 1999), which served to better understand concordance of the toxicity of pharmaceuticals observed in humans with that observed in experimental animals. The Workshop included representatives from academia, the multinational pharmaceutical industry, and international regulatory scientists. The main aim of this project was to examine the strengths and weaknesses of animal studies to predict human toxicity (HT). The database was developed from a survey which covered only those compounds where HTs were identified during clinical development of new pharmaceuticals, determining whether animal toxicity studies identified concordant target organ toxicities in humans. Data collected included codified compounds, therapeutic category, the HT organ system affected, and the species and duration of studies in which the corresponding HT was either first identified or not observed. This survey includes input from 12 pharmaceutical companies with data compiled from 150 compounds with 221 HT events reported. Multiple HTs were reported in 47 cases. The results showed the true positive HT concordance rate of 71% for rodent and nonrodent species, with nonrodents alone being predictive for 63% of HTs and rodents alone for 43%. The highest incidence of overall concordance was seen in hematological, gastrointestinal, and cardiovascular HTs, and the least was seen in cutaneous HT. Where animal models, in one or more species, identified concordant HT, 94% were first observed in studies of 1 month or less in duration. These survey results support the value of in vivo toxicology studies to predict for many significant HTs associated with pharmaceuticals and have helped to identify HT categories that may benefit from improved methods.

Animals↗

PubMed2000

Isolation and characterization of a self-sufficient one-domain protein. (Cd)-metallothionein from Eisenia foetida.

Earthworms have been shown to accumulate trace elements in general, and particularly high amounts of metal ions such as cadmium, copper and zinc. The earthworm's response to metal contamination has been linked to the induction and expression of metallothionein (MT) proteins, a detoxification strategy analogous to that found in other biological systems. The present study focuses on an inducible Cd-MT isolated from the compost-dwelling brandling worm Eisenia foetida (Savigny). A full characterization of the protein (including protein induction, MT cDNA, amino-acid sequence and metal stoichiometry) revealed a new dimension of knowledge to the molecular genetic information available to date. Whereas the elucidated cDNA codes for a putative protein which possesses 80 amino-acid residues, the characterized protein bears only 41 amino acids. The isolated product has evidently attained its size and shape by cleavage near the N-terminal site and at the linker region between the two putative metal-binding domains of the translated product, yielding a small MT moiety which contains 12 Cys residues (including one triple Cys-motif) binding four cadmium ions. It can be shown that the isolated MT molecule represents a self-sufficient one-domain MT which is stable in vitro. The isolation of the single-domain MT peptide raises the question about the method of formation and significance in vivo of such small MT moieties from tissues of E. foetida and possibly other terrestrial invertebrates. In this respect, two hypotheses are discussed: firstly, the possibility of formation of small MT peptides due to enzymatic cleavage of the intact protein during the process of preparation and isolation; and secondly, the possibility of deliberate post-translational processing of the translated gene product to yield functional one-domain MT moieties.

Amino Acid Sequence↗