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Biomedical subjects

L Bachmann

Publications and source records attributed to L Bachmann.

At least 19 recordsLinked to original sources

Hammerhead-mediated processing of satellite pDo500 family transcripts from Dolichopoda cave crickets.

This work reports the discovery and functional characterization of catalytically active hammerhead motifs within satellite DNA of the pDo500 family from several DOLICHOPODA: cave cricket species. We show that in vitro transcribed RNA of some members of this satellite DNA family do self-cleave in vitro. This self-cleavage activity is correlated with the efficient in vivo processing of long primary transcripts into monomer-sized RNA. The high sequence conservation of the satellite pDo500 DNA family among genetically isolated DOLICHOPODA: schiavazzii populations, as well as other DOLICHOPODA: species, along with the fact that satellite members are actively transcribed in vivo suggests that the hammerhead-encoding satellite transcripts are under selective pressure, perhaps because they fulfil an important physiological role or function. Remarkably, this is the third example of hammerhead ribozyme structures associated with transcribed repetitive DNA sequences from animals. The possibility that such an association may not be purely coincidental is discussed.

Animals↗

Expression of adhesion molecules in skin wounds: diagnostic value in legal medicine.

The adhesion molecules identified in recent years can help improve the diagnosis of the wound age, especially of injuries with a short survival time. This is also indicative of the vitality of the wounds. The material investigated in the study originated from 465 skin wounds. The samples were taken from human autopsy material, during the surgical treatment of wounds (excision) of patients and from experimental incised wounds of mice. To judge the age of skin wounds the endothelial adhesion molecules were detected in paraffin sections after autoclaving and using the ABC technique. Human skin wounds: strong positive staining was observed of ICAM-1 1.5 h at the earliest and 3.5 days at the latest, for the P-selectin 3 min at the earliest and 7 h at the latest, for the E-selectin 1 h at the earliest and 17 days at the latest and for VCAM-1 3 h at the earliest and 3.5 days at the latest after the time of injury. The L-selectin was expressed constitutively. Mice skin wounds: strong positive immunohistochemical reactions were found as a rule earlier than in human skin wounds. The detection of an increased expression of ICAM-1, VCAM-1 and P- and E-selectins can improve the wound age assessment in injuries with short survival times.

Animals↗

Genomic differentiation of Neanderthals and anatomically modern man allows a fossil-DNA-based classification of morphologically indistinguishable hominid bones.

Southern blot hybridizations of genomic DNA were introduced as a relatively simple fossil-DNA-based approach to classify remains of Neanderthals. When hybridized with genomic DNA of either human or Neanderthal origin, DNA extracted from two Neanderthal finds-the Os parietale, from Warendorf-Neuwarendorf, Germany, and a clavicula, from Krapina, Croatia-was shown to yield hybridization signals that differ by at least a factor of two compared to the signals obtained with the use of fossil DNA of an early Homo sapiens from the Vogelherd cave (Stetten I), Germany. When labeled chimpanzee DNA was used as a probe, Neanderthal and human DNA, however, revealed hybridization signals of similar intensity. Thus, the genome of Neanderthals is expected to differ significantly from the genome of anatomically modern man, because of the contrasting composition of repetitive DNA. These data support the hypothesis that Neanderthals were not ancestors of anatomically modern man.

Animals↗

Voltage-induced release of nucleic acids from palaeontological samples.

Most of the protocols for the recovery of ancient DNA from palaeontological specimens are time-consuming and tend to yield inconsistent polymerase chain reaction (PCR) results. "Voltage-induced release" is a novel and rapid approach for the extraction of ancient DNA. Nucleic acids are directly electrophoresed out of powder derived from hard and soft tissues. This technique is much faster than other methods in which pulverized tissue conventionally undergoes time-consuming crude lysis steps. The total preparation time is 5-6 h. The reliability of the voltage-induced release method was validated by (i) measuring the ratio of D-to L-enantiomers of the amino acids aspartic acid, alanine, and leucine, and (ii) by specific PCR amplification of four single-copy markers of human chromosome 17 and 18. We compare voltage-induced release to a frequently used silica-based protocol. DNA extracted employing voltage-induced release was more effective in PCR amplifications, which may be attributed to the effective removal of PCR inhibitors.

DNA↗

Evolutionary dynamics of the SGM transposon family in the Drosophila obscura species group.

SGM (Drosophila subobscura, Drosophila guanche, and Drosophila madeirensis) transposons are a family of transposable elements (TEs) in Drosophila with some functional and structural similarities to miniature inverted-repeat transposable elements (MITEs). These elements were recently active in D. subobscura and D. madeirensis (1-2 MYA), but in D. guanche (3-4 MYA), they gave rise to a species-specifically amplified satellite DNA making up approximately 10% of its genome. SGM elements were already active in the common ancestor of all three species, giving rise to the A-type specific promoter section of the P:-related neogene cluster. SGM sequences are similar to elements found in other obscura group species, such as the ISY elements in D. miranda and the ISamb elements in Drosophila ambigua. SGM elements are composed of different sequence modules, and some of them, i.e., LS and LS-core, are found throughout the Drosophila and Sophophora radiation with similarity to more distantly related TEs. The LS-core module is highly enriched in the noncoding sections of the Drosophila melanogaster genome, suggesting potential regulatory host gene functions. The SGM elements can be considered as a model system elucidating the evolutionary dynamics of mobile elements in their arms race with host-directed silencing mechanisms and their evolutionary impact on the structure and composition of their respective host genomes.

Animals↗

[Significance of selenium in regulation of inflammatory response by transcription factors in polytrauma patients. A clinical study].

The authors have investigated the relationship between selenium and transcription factors (NF-kappa B and AP-1) in the field of pathogenesis of polytrauma. Correlations between plasma selenium content and transcription factor binding activity have been found. The measured connecting capacitances of transcription factors have been associated with the severity of disease. To harden the results of this research a randomized double blind study with sodium selenite substitution is necessary next. This study will be to establish the therapy with sodium selenite in the treatment of polytrauma.

APACHE↗

Estimation of wound age and VCAM-1 in human skin.

To estimate the age of skin wounds, the endothelial adhesion molecule VCAM-1 (CD 106) was detected in paraffin sections after autoclaving and using the ABC technique. The percentage of VCAM-1 positive blood vessels was determined after the blood vessels had been marked with PECAM-1 (CD 31). Low positive staining reactions were observed for VCAM-1 on endothelial cells of uninjured skin in 18% of the samples. In injured skin, 51% of the cases investigated showed a VCAM-1 expression. Strong positive staining reactions were observed 3 h at the earliest and 3.5 days at the latest after the time of injury. The immunohistochemical results for VCAM-1 differed significantly between the injured and uninjured skin (P < 0.01). In a few cases VCAM-1 was detected (n = 6) at low intensity in postmortem skin wounds and a moderate to strong expression of VCAM-1 is indicative of the vitality of the wound. The detection of VCAM-1 can be used for estimating the age of wounds in forensic applications if the degree of expression of further adhesion molecules, especially that of selectins, is taken into account.

Forensic Medicine↗

Human hypersensitivity angiitis: an uncommon cause of death after trauma.

INTRODUCTION: The article demonstrates, using a case report, that death following an accident may have rarely encountered causes that are not a direct result of trauma and that can only be detected by autopsy. CASE: An unconscious woman aged 57 years was admitted to hospital. Despite immediate surgery for intracranial haemorrhage diagnosed by means of cranial computed tomography, the patient died showing clinical symptoms of circulatory depression after a brief period of stabilisation. The autopsy established myocardial infarction with hypersensitivity angiitis as the cause of death. CONCLUSION: In this case, the authors hold the opinion that the intravenous application of antibiotics during the patient's stay in hospital resulted in hypersensitivity angiitis. The factors causing hypersensitivity angiitis, the morphological picture (clinical, histological) and therapeutic measures are described.

Anti-Bacterial Agents↗

Under the influence: risky sexual behavior and substance abuse among driving under the influence offenders.

BACKGROUND AND OBJECTIVES: The purpose of this study was to examine the associations between alcohol and drug abuse and risky sexual practice in a sample of 366 driving under the influence (DUI) offenders. STUDY DESIGN: Data were collected from a sample of participants at a university-operated drunk driving intervention program. Specific indicators included established or severe alcohol/drug use problems, multiple drugs used, multiple alcohol/drug related arrests, and early regular alcohol use. Multiple sexual partners, condom use, and having sex while under the influence of alcohol or drugs were used to measure risky sexual behavior patterns. Correlation and logistic regression analyses examined associations between these substance abuse and sexual risk taking measures. RESULTS: Substance abuse in general was unrelated to risky sexual behavior such as multiple sexual partners or lack of condom use. However, having sex while high from alcohol or drugs was significantly associated with substance abuse. Moreover, having sex while high was significantly related to both risky sex and a history of sexually transmitted disease. CONCLUSIONS: Having sex while high may be an important behavior to address to prevent STDs in the DUI population. Assessing relationships between substance abuse and risky sexual behavior poses a challenge to researchers because any estimates about this association may be dependent on the measure of sexual behavior that is used. An integrated intervention approach that addresses both substance abuse prevention and safe sexual practice appears crucial and effective for educating "risk takers" such as DUI offenders. However, these data caution that for those who are dependent upon alcohol and/or other drugs, education solely emphasizing risk reduction procedures is likely to be inefficient until their chemical dependency is addressed.

Adult↗

Microdomain arrangement of the SERCA-type Ca2+ pump (Ca2+-ATPase) in subplasmalemmal calcium stores of paramecium cells.

We localized SERCA pumps to the inner region of alveolar sac membranes, facing the cell interior, by combining ultrastructural and biochemical methods. Immunogold labeling largely predominated in the inner alveolar sac region which displayed aggregates of intramembrane particles (IMPs). On image analysis, these represented oligomeric arrangements of approximately 8-nm large IMP subunits, suggesting formation of SERCA aggregates (as known from sarcoplasmic reticulum). We found not only monomers of typical molecular size ( approximately 106 kD) but also oligomeric forms on Western blots (using anti-SERCA antibodies, also against endogenous SERCA from alveolar sacs) and on electrophoresis gelautoradiographs of 32P-labeled phosphoenzyme intermediates. Selective enrichment of SERCA-pump molecules in the inner alveolar sac membrane region may eliminate Ca2+ after centripetal spread observed during exocytosis activation, while the plasmalemmal Ca2+ pump may maintain or reestablish [Ca2+] in the narrow subplasmalemmal space between the outer alveolar sac membrane region and the cell membrane. We show for the first time the microzonal arrangement of SERCA molecules in a Ca2+ store of a secretory system, an intensely discussed issue in stimulus-secretion coupling research.

Animals↗

Enhanced expression of selectins in human skin wounds.

The aim of the study was to characterize the vitality and age of skin wounds by the detection of selectins. A prospective study was conducted for this purpose in which 197 vital human skin wounds (time since injury ranging from 3 min to 790 days) were investigated immunohistologically. Of the samples tested, 97 were taken from autopsy material and 100 from patient material from the department of surgery at the university hospital. The selectins were detected in paraffin sections after autoclaving and using the ABC technique. The intensity was rated by a semi-quantitative evaluation using a four-stage ordinal scale. Strong positive immunohistochemical reactions were observed for the P-selectin 3 min at the earliest and 7 h at the latest after the time of injury. For the E-selectin a positive staining was evident I h at the earliest and 17 days at the latest from the time the skin was injured. The staining intensity decreased significantly after an interval of 12 h from the time of injury (P < 0.05). The L-selectin was regularly detected on leukocytes in the samples of injured skin. The immunohistochemical results for the P- and E-selectins were significantly different between injured and uninjured skin (P < 0.01). The expression of the selectins is indicative of the vitality of the wound. P-selectin was detected in a few cases (n=4) at low intensity while E-selectin could not be found in the control samples (n=31) of postmortem skin wounds. The use of P- and E-selectins for forensic purposes can help to achieve better estimates of the age of wounds with short survival times.

Female↗

Compliance with doxycycline therapy in sexually transmitted diseases clinics.

OBJECTIVE: To determine rates of compliance with doxycycline therapy for patients attending two inner city sexually transmitted diseases (STD) clinics using the MEMS (Medication Event Monitoring System) technology (Aprex Corporation, Fremont, CA). DESIGN: An observational study. SETTING: Two STD clinics in Brooklyn, New York and Birmingham, Alabama. PATIENTS: Patients warranting doxycycline as antichlamydial therapy by usual clinical criteria (e.g., documented chlamydial infections, gonococcal urethritis, mucopurulent cervicitis) were enrolled consecutively from both clinics into four separate categories according to gender and the presence or absence of symptoms: symptomatic men (77), asymptomatic men (30), symptomatic women (83), asymptomatic women (33). INTERVENTION: In the clinic area, patients were given their doxycycline in standard 30-dram medication bottles fitted with the MEMS cap, which is capable of recording the date and time of each bottle opening and closing. This information was then retrieved using a software program developed by the manufacturer. Patients were instructed to return the bottle and cap at the completion of therapy. Efforts were made to contact those who did not return their bottles by both telephone and mail. OUTCOME MEASURES: Bottle openings as recorded by the MEMS were considered to represent use of medication. Patients were considered strictly compliant with prescription instructions if bottle openings and closings occurred at least twice daily for 6 consecutive days. Noncompliance was defined as initially opening the medication more than 48 hours after leaving the clinic or opening the bottle less than once daily for 5 consecutive days. Usage between these extremes was classified as intermediate. RESULTS: Eighty percent of 223 patients enrolled completed the study by returning their bottles. The rate of strict compliance with prescription instruction was 25%. The rate of noncompliance was 24%. Fifty-one percent used some intermediate amount of medication. There was no statistical difference in compliance by gender, presence or absence of symptoms, or site of enrollment. CONCLUSIONS: Few patients administered doxycycline in an STD clinic can be expected to take medication precisely as prescribed. Although most probably take enough to eradicate uncomplicated chlamydial infections, a sizable portion can be expected to use an inadequate amount of medication. This may contribute to persistence of genital chlamydia infections in the community.

Adult↗

Enhanced expression of ICAM-1 (CD 54) in human skin wounds: diagnostic value in legal medicine.

OBJECTIVE: It was the aim of this study to characterize the vitality and the age of skin wounds by verifying the presence of ICAM-1. MATERIAL: 132 intravital human skin wounds (time since injury 15 min-19 days) were investigated by immunohistochemistry. The samples were taken either after surgical treatment of the wounds or from autopsy cases. METHODS: CD 54 was detected in paraffin sections by monoclonal antibodies after an autoclaving pretreatment using the ABC peroxidase technique. RESULTS: In samples of uninjured skin (n = 30), ICAM-1 appeared at a low concentration on keratinocytes and the endothelial cells of blood vessels. In injured skin, an increase in the surface expression was found to occur initially after a post-trauma interval of 2 h. The evaluation was made on a semiquantitative basis. A moderate to strong ICAM-1 expression occurred in 80% of the wounds investigated. CONCLUSIONS: The expression of ICAM-1 correlates with the degree of wound inflammation, which may be considered as an early evidence of the vitality of the wound.

Forensic Medicine↗

Time dependence of the expression of ICAM-1 (CD 54) in human skin wounds.

To characterize the vitality and age of skin wounds by means of the ICAM-1 pattern, 157 intravital human skin wounds (time since injury ranging from 5 min to 730 days) were immunohistochemically investigated. ICAM-1 was detected in paraffin sections after autoclaving and using the ABC technique in 86% of the wounds investigated. The correlation between ICAM-1 expression and the degree of wound inflammation is weak. Strong positive staining was observed 1.5 h at the earliest and 3.5 days at the latest after the time of injury. ICAM-1 also appeared at low concentrations in samples of uninjured skin (n = 65), on keratinocytes and the endothelial cells of blood vessels. Moderate to strong ICAM-1 expression is a valuable indication of the vitality of the wound. However, at present the detection of ICAM-1 alone is not sufficient to fix the wound age with the accuracy which is required for forensics applications.

Adult↗