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Biomedical subjects

B Herrmann

Publications and source records attributed to B Herrmann.

At least 19 recordsLinked to original sources
PubMed2002

Traumatic subarachnoidal hemorrhage in the developing rat.

The aim of the present study was to utilize an experimental traumatic subarachnoidal hemorrhage model in the developing rat. Diffuse brain injury was produced in intubated and ventilated 21 to 25 days old Sprague-Dawley rats (N = 10) using a modification (1 m/100 g) of the Marmarou-model. Before induction of the injury heparin was administered i.v. and antagonised after injury by protamine. Mean arterial blood pressure and intracranial pressure was measured continuously. Histopathological investigations were performed. The results were compared to readings in adult animals (N = 12) subjected to a 1.5 m/500 g injury. In the developing rat ICP increased immediately following injury from 11.4 +/- 2.1 mm Hg to 55.9 +/- 20.3 mm Hg. It remained elevated till the end of the experiment 1 h after injury. MABP increased from 79.8 +/- 8.7 mm Hg to 100.2 +/- 21.7 mm Hg immediately following injury, returning to 61.3 +/- 28.7 mm Hg at the end of the experiment resulting in a marked decrease of CPP. The mortality rate was 60%. All brains showed a severe subarachnoidal hemorrhage in the basal cisterns. The increase of ICP following injury is attributable to the bleeding similar as in adult animals. The high mortality is due to the marked decrease of CPP. Rat pups are more vulnerable to t-SAH compared to adult rats.

Aging↗
PubMed2002

Syphilis, gonorrhoea and chlamydial infection among women undergoing legal or illegal abortion in Maputo.

Our objectives were to compare the prevalence of sexually transmitted infections (STIs) in 103 women undergoing induced legal abortion (LA) and in 101 women with confirmed, recent illegal abortion (IA), in Maputo, Mozambique. For the purpose of this study, LA was considered the abortion provided in the Maputo Central Hospital with the approval of the Ministry of Health, and IA the one not provided through the approved facility, mentioned above. Women with IA were recruited in the outpatient gynaecology ward and women with LA in the emergency gynaecology ward in the Maputo Central Hospital, during the same time period. Serological tests for syphilis (rapid plasma reagin, ELISA-IgG and fluorescent treponemal antibody absorption), gonorrhoea (indirect haemagglutination) and chlamydia (microimmunofluorescence) were carried out. Direct immunofluorescence for detection of Chlamydia trachomatis antigen was done on endocervical smears from all the women. The prevalence of syphilis seropositivity in IA women is twice that of LA women (odds ratio [OR] 2.13; 95% confidence interval [CI] 0.55-9.95), with 10.9% and 4.9%, respectively. Exposure to gonorrhoea in these 2 groups is similar (OR 1.18; 95% CI 0.63-2.20), with seroprevalence of 31.1% in the LA and 34.7% in the IA group. The high titres are also similar in both groups. Serology findings for C. trachomatis indicate prevalence of seropositivity of 40.6% in the LA and 44.4% in the IA group with no significant difference (OR 1.17; 95% CI 0.64-2.13). In conclusion, STIs are highly prevalent in both IA and LA groups in Maputo. Urgent interventions are needed to reduce their prevalence and consequently their adverse consequences.

Abortion, Induced↗
PubMed2001

Selective inner hair cell loss in premature infants and cochlea pathological patterns from neonatal intensive care unit autopsies.

BACKGROUND: Deafness and handicapping sensorineural hearing impairment occur frequently in neonatal intensive care unit survivors for unknown reasons. PATIENTS AND METHODS: Hearing was tested early and repeatedly in neonatal intensive care unit patients with an auditory brainstem response (ABR) screener. The temporal bones of 15 nonsurvivors (30 ears) were fixed promptly (average, 5 hours) after death for histological evaluation. RESULTS: Among these patients, 12 failed the ABR screen bilaterally, 1 passed unilaterally, and 2 passed bilaterally. Cochlear histopathologic conditions that could contribute to hearing loss included bilateral selective outer hair cell loss in 2 patients, bilateral selective inner hair cell loss in 3 (all premature), and a combination of both outer and inner hair cell loss in 2. Other hair cell abnormalities were noted; the 2 infants who had passed the ABR screen demonstrated normal histological features. Neuronal counts were normal. CONCLUSIONS: Auditory brainstem response failure among these neonatal intensive care unit infants who died was extremely common in part owing to an unexpected histological alteration, selective inner hair cell loss among premature newborns, that should be detectable uniquely by the ABR testing method. Additional histological patterns suggest more than one cause for neonatal intensive care unit hearing loss. Hair cell loss patterns seem frequently compatible with in utero damage.

Cochlea↗
PubMed2001

Respiratory syncytial virus and chlamydia are not detectable by PCR in ongoing vernal keratoconjunctivitis.

Respiratory syncytial virus (RSV) and chlamydial infection may be pathogenetic factors in allergic diseases, perhaps also in ocular allergy. We analyzed the presence of RSV and chlamydial nucleic acids using reverse transcription (RT)-PCR and PCR, respectively, in conjunctival biopsies from patients with vernal keratoconjunctivitis (VKC) in order to determine whether these agents play a role in the maintenance of the disease. All biopsy samples were negative for both RSV (n = 15 for VKC and n = 10 for control subjects) and chlamydia (n = 8 for VKC and n = 7 for control subjects) homologous sequences. A direct association between RSV or chlamydial infection and ongoing inflammation in VKC could, therefore, not be confirmed.

Adolescent↗
PubMed2001

The minimum speech test battery in profound unilateral hearing loss.

OBJECTIVE: Individuals with monaural hearing experience disadvantages compared with normal hearing counterparts because of the loss of the head shadow effect, the squelch effect, and binaural summation. In this study the Minimum Speech Test Battery (MSTB), a battery designed to document word recognition in bilaterally hearing impaired cochlear implant candidates, was administered to unilaterally hearing-impaired and normal hearing subjects to study its possible use in measuring hearing difficulty in monaural subjects. STUDY DESIGN: Repeated measures design with the MSTB administered in sound-field in a sound-isolated booth in 1) quiet; 2) speech toward good ear, noise (+10 dB S/N) toward impaired ear; 3) speech toward impaired ear, noise toward good ear; and 4) bilateral speech and noise. SETTING: Academic otologic practice. PATIENTS: Ten adults with normal hearing and 10 adults with normal or near-normal hearing in one ear and profound hearing loss in the contralateral ear. MAIN OUTCOME MEASURES: The MSTB, composed of the Consonant-Nucleus-Consonant (CNC) test and the Hearing In Noise Test (HINT). RESULTS: As expected, performance differences between the groups were not found in quiet conditions. Analysis of variance and regression analysis confirmed that the impaired group performed significantly worse than control subjects on HINT testing when noise was directed toward the good ear. Analysis of variance and regression analysis confirmed that the impaired group performed significantly worse than control subjects on CNC testing when noise was directed toward the good ear and in bilateral noise. CONCLUSIONS: The MSTB may be useful in measuring the hearing difficulty of patients with monaural hearing.

Adult↗
PubMed2001

Simultaneous detection and typing of influenza viruses A and B by a nested reverse transcription-PCR: comparison to virus isolation and antigen detection by immunofluorescence and optical immunoassay (FLU OIA).

A nested reverse transcription (RT)-PCR was developed for simultaneous detection and typing of influenza viruses A and B. The detection limit for influenza virus A subtypes H1 and H3 and that for influenza virus B were between 1 and 4 target gene copies per reaction for each type. The clinical benefit of the RT-PCR method was evaluated by comparing the results with virus isolation and direct immunofluorescence (IF) assays on 215 nasopharyngeal aspirates from patients with suspected influenza virus infection. The RT-PCR detected 83 cases of influenza A, compared to 66 cases detected by virus isolation and 68 cases detected by IF assay. The corresponding figures for the detection of influenza B were 15, 12, and 11 cases, respectively. In total, 16 out of 98 RT-PCR-positive specimens were negative by virus isolation and IF. An optical immunoassay for rapid detection of influenza A and B (FLU OIA; Bio Star Inc., Boulder, Colo.) was compared to RT-PCR and IF on 105 nasopharyngeal aspirates and 79 swabs. The sensitivity for the OIA was 40.4% compared to PCR and 48.8% compared to IF assay, when nasopharyngeal aspirates were examined. The specificities were 94.3 and 93.9%, respectively. The sensitivity was higher for OIA on nasopharyngeal swabs, 77.5% and 86.6% compared to PCR and IF, respectively, while the specificity was lower, 82.0% and 75.5%, respectively. The RT-PCR provides a sensitive and specific method for detecting and typing influenza viruses A and B. The rapid OIA is useful as a complementary test, but it cannot replace established methods without further evaluation.

Adolescent↗
PubMed2001

Role of T lymphocytes in rat 2,4,6-trinitrobenzene sulphonic acid (TNBS) induced colitis: increased mortality after gammadelta T cell depletion and no effect of alphabeta T cell depletion.

BACKGROUND AND AIM: Indirect evidence suggests that CD4+ T cells have a pathogenic while gammadelta T cells have a protective role in the initiation and perpetuation of inflammatory bowel disease. To define the role of T cell subsets in a rat colitis model (2,4,6-trinitrobenzene sulphonic acid (TNBS)) we analysed colitis severity after effective depletion of T helper cells, alphabeta T cells, or gammadelta T cells. METHODS: T helper cells, alphabeta T cells, or gammadelta T cells were depleted using previously described monoclonal antibodies directed at the CD4 molecule (OX38), the CD2 molecule (OX34, both depleting CD4+ T cells), the alphabeta T cell receptor (R73), and the gammadelta T cell receptor (V65). Depletion was verified by flow cytometry and/or immunohistology. Colitis was induced using intracolonic application of TNBS. RESULTS: Surprisingly, depletion of T helper cells or alphabeta T cells had no influence on survival, macroscopic or microscopic scores, or myeloperoxidase activity following colitis induction. In contrast, depletion of gammadelta T cells resulted in significantly increased mortality (V65: 73%, n=15) compared with controls (30%, n=13; p<0.03). In addition, colitis was histologically more severe in the gammadelta T cell depleted group compared with controls (p<0.05). CONCLUSIONS: T helper cells or alphabeta T cells did not influence the initiation or perpetuation of rat TNBS colitis. In contrast, gammadelta T cells had a protective role in rat TNBS colitis as depletion caused increased mortality.

Animals↗
PubMed2000

Characterization of the rnpB gene and RNase P RNA in the order Chlamydiales.

The sequence of the RNase P RNA gene (rnpB) was determined for 60 strains representing all nine species in the family Chlamydiaceae and for the related Chlamydiales species, Parachlamydia acanthamoebae and Simkania negevensis. These sequences were used to infer evolutionary relationships among the Chlamydiaceae. The analysis separated Chlamydophila and Chlamydia into two lineages, with Chlamydophila forming three distinct clusters: the Chlamydophila pneumoniae strains; the Chlamydophila pecorum strains; and a third cluster comprising the species Chlamydophila psittaci, Chlamydophila abortus, Chlamydophila caviae and Chlamydophila felis. The Chlamydia line of descent contained two clusters, with the Chlamydia suis strains distinctly separated from strains of Chlamydia trachomatis and Chlamydia muridarum. This analysis indicated that the rnpB sequence and structure are distinctive markers for species in the Chlamydiaceae. It was also demonstrated that the RNase P RNA derived from Chlamydia trachomatis is able to cleave a tRNA precursor in the absence of protein. These findings are discussed in relation to the structure of Chlamydia RNase P RNA.

Animals↗
PubMed2000

Molecular sex identification of stillborn and neonate individuals ("Traufkinder") from the burial site Aegerten.

The study reconstructs the sex ratio of 121 stillborn and neonate individuals from the early modern burial site Aegerten, Switzerland. The immature individuals, who were not baptised before death, were buried along the walls of the church. To perform a molecular sex identification, bone samples from the infants were collected from different skeletal elements. Ancient DNA (aDNA) was isolated by a combination of automated phenol/chloroform extraction and precipitation with silica powder. A combination of manuell Chelex extraction and purification kit was also used to perform an extraction. Finally, the aDNA extracts were amplified with a primer system that amplifies a part of the amelogenin gene located on the human sex chromosomes. The morphometrical sex determination of the children suggests a large disproportion of female individuals (about 60%). This finding was compared to PCR-based amplification results. In contrast, the results of the molecular sex identification were a high proportion of male individuals. Looking at these results, it should be noted that the high mortality of male individuals during the last months of pregnancy and during the first month after birth is in accordance with the natural sequence of death also found in recent populations.

Female↗
PubMed2000

Evaluation of morphological sex determinations by molecular analyses.

The study presents an evaluation of morphological sex determinations of adult skeletal individuals based on traits of the ossa coxae and the cranium. The evaluation criterion was genetic analysis of the amelogenine gene, which represents parts of the X- and the Y-chromosome (Mannucci et al. 1994). The study was carried out on 33 human skeletons from an early modern burial site in Lower Saxony. In this skeletal series, 88% of the morphological sex determinations matched the genetic sex. The percentage of matches was further improved, if only those morphological determinations were taken into account that were classified as unambiguous by a self-evaluation. In the reverse case, a significant number of non-matching determinations (33%) resulted from those cases in which a sex determination still seemed possible but was classified as "ambiguous" in the self-evaluation. At least within this skeletal series, no clear connection could be detected between the number of matching results and the presence or absence of the ossa coxae. This might be due to a strong cranial dimorphism within this particular skeletal series.

Adult↗
PubMed2000

Megaplex DNA typing can provide a strong indication of the authenticity of ancient DNA amplifications by clearly recognizing any possible type of modern contamination.

Recent experiments revealed the perfect applicability of megaplex typing by autosomal short tandem repeats (STRs) to degraded DNA. The advantages of megaplex approaches lie in reduced amounts of sample material that are necessary and in remarkable time saving. Furthermore, megaplex typing clearly recognizes possible contaminations and thus has a large potential for indicating authenticity in ancient DNA analysis. This is demonstrated by three examples in which various types of contaminations could clearly be identified as such and even traced back to their origin. This would have been impossible using control samples, due to the sporadic nature of these types of contaminations.

Artifacts↗
PubMed2000

STR-genotyping of archaeological human bone: experimental design to improve reproducibility by optimisation of DNA extraction.

The analysis of degraded DNA with the help of short tandem repeat loci (STRs) is an important source of information both in forensic casework and in the anthropological context. The reproducibility of STR-genotyping of highly degraded or "ancient" DNA can be reduced by the generation of artifacts during PCR amplification. The frequency and amount of these artifacts--allelic dropout and the generation of shadow bands--are related to the quality and quantity of the extracted DNA amplified in a PCR reaction. Therefore, one important strategy to increase the reproducibility of STR-genotyping of samples containing degraded DNA is the optimisation of the DNA extraction.

Archaeology↗
PubMed2000

Ancient DNA-typing approaches for the determination of kinship in a disturbed collective burial site.

Several DNA-typing approaches are applied for identification and kinship analysis. Autosomal Short Tandem Repeat (STR) typing produces the genetic fingerprint that is unique to an individual. Y-chromosomal STR typing identifies individuals of the same paternal lineage, and sequence analysis of the hypervariable region of the mitochondrion can identify maternally related individuals. The combined approach of these DNA-typing methods allows the determination of kinship even in complex collective burial situations. In a bronze age collective site, the typing methods were tested for applicability to ancient DNA. For each approach, results were obtained, leading to the conclusion that the determination of kinship is achievable.

Bone and Bones↗
PubMed2000

STR allelic frequencies in a German skeleton collection.

Chromosomal DNA was isolated from bones from a German skeleton collection (Goslar, 18th century) and detected by PCR. Nine microsatellite regions were amplified by multiplex reactions using the AmpFlSTR Profiler Plus kit and analysed to obtain their allelic distribution. A statistical evaluation of the results revealed no allelic differentiation between the historic sample and a modern German one at each locus.

Alleles↗
PubMed2000

Reconstruction of kinship by fecal DNA analysis of orangutans.

Genetic analysis is a useful tool for assigning biological relationships. Thus, it will improve genetic management of wild animal populations and breeding colonies. Kinship analysis will give new insights into the behavior, sociobiology and genetic management of orangutans. In this study, chromosomal DNA from orangutan (Pongo pygmaeus ssp.) was extracted from excrements. Feces samples were screened for up to nine microsatellite markers from related zoo populations of orangutans (Pongo pygmaeus ssp.) kept at the Zoological Garden Berlin and the Zoological Garden Heidelberg, Germany. Family structures are documented in the "International Studybook of the Orangutan" (Perkins 1995) and the "Europäisches Erhaltungszucht Programm 1998" (Becker 1998). To examine whether human short tandem repeat loci (STR) are suitable for the reconstruction of kinship in orangutans, nine STRs, commonly used in forensic studies and the amelogenin system, were amplified in a multiplex-PCR approach (AmpFlSTR Profiler Plus). We were able to show that five of the nine human autosomal STRs in question amplified successfully in orangutans. Thus, we could reconstruct kinship structures of the Berlin and Heidelberg populations.

Amelogenin↗
PubMed2000

Palaeogenetic analysis of (pre)historic artifacts and its significance for anthropology.

The possibility of isolating ancient DNA (aDNA) from all kinds of (pre)historic anthropogenetic artifacts opens new perspectives. This study applies palaeogenetic techniques to three anthropological issues: 1. Palaeodiet. DNA sequences from organic residues in vessels identify Precolumbian Aztec diet. 2. (Pre)historic husbandry and economic structures. aDNA data can reveal the species and the genetic evolutionary stage of animals and plants and show the manner and the extent of their growth, cultivation, or domestication. 3. Production techniques, use, and functionality. Identification of the plant or animal source of an archaeological find can reveal the use or the function of the find. Examples from a Celtic "sausage-end" and an Aztec "eye salve" are given.

Archaeology↗
PubMed2000

Trace analysis of endogenous and exogenous biomolecules from archaeological skeleton materials.

An analytical procedure was developed for the determination of pharmacologically active substances in archaeological skeleton materials. In comparative model studies, added ("spiked") test biomolecules of varying chemical behaviours were extracted from sample matrices and percentage of the analytes recovered were estimated using gas chromatography/mass spectrometry (GC/MS) or high performance liquid chromatography (HPLC). For the sterols and steroids studied, several organic solvents were appropriate. Extraction yields for the alkaloid nicotine, representing non-endogenous basic agents, were increased by alkalizing with triethylamine or by extracting with a two-phase system consisting of an alkaline aqueous and an organic layer (toluene). The flavonol quercetin was extractable only in an acidic environment. In a screening for native biomolecules using GC/MS, nicotine was identified in individual samples, in addition to lipophilic substances such as the endogenous cholesterol and its degradation products and two phytosterols which may have migrated into the bones from the surrounding soil.

Alkaloids↗