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Biomedical subjects

J Lamprecht

Publications and source records attributed to J Lamprecht.

At least 19 recordsLinked to original sources
PubMed2001

Flow cytometric analysis of the Th1-Th2 balance in healthy individuals and patients infected with the human immunodeficiency virus (HIV) receiving a plant sterol/sterolin mixture.

The Th1--Th2 balance plays a pivotal role in determining the outcome of an immune response to an infectious organism. It is proposed that during HIV infection, disease progression is characterized by a loss of Th1 activity, a shift to a more 'allergic' Th2-type response and hence loss of cytotoxic cell activity against infected host cells. This study was undertaken to investigate this balance in three groups of individuals: HIV-negative volunteers (n=10), a group of HIV-infected patients on no therapy (n=10) as well as a group of patients managed with a mixture of plant sterols/sterolins (n=9). In parallel, their response to mitogens and the subsequent expression of the activation antigen CD69 was measured. This study was conducted by three-colour flow cytometry in order to obviate the less sensitive cytokine secretion assays that have yielded controversial results. The results indicate that HIV-infected patients on no therapy exhibit a pre-dominant Th2 response (IL-4 secretion), whereas those on the sterol/sterolin mixture exhibit a beneficial Th1 response (IFN-gamma). Surprisingly, in both patient groups, the expression of CD69 was abnormally low when compared to the uninfected volunteers, implying that chronic activation is already present in vivo. It appears that the detrimental Th2 driven response might be swung to the more beneficial Th1 response with the immune modulatory sterols/sterolin mixture. Clinical use of this mixture in HIV infection has yielded results which corroborate the above observations in that patients using the plant sterol/sterolin mixture maintain their CD4 cell numbers over an extended period of time in the absence of any anti-retroviral therapy.

ATP Binding Cassette Transporter, Subfamily G, Mem↗
PubMed2000

[Studies on conditions for the culture of rabbit corneal epithelium].

PURPOSE: Research was aimed at comparison of isolation methods as well as determination of growth and differentiation dynamics of rabbit corneal epithelium (CE) in vitro. Adhesion, growth and differentiation of CE cells growing on collagen membranes were evaluated. MATERIAL AND METHODS: Research was performed on the cells of rabbit corneal epithelium isolated mechanically or enzymatically (Dispase II) from comeas excised at the edge of limbus. CE cells were cultured in media with high or low contents of calcium, with addition of FCS, insulin, cholera toxin and EGF. RESULTS: In comparison with mechanical isolation, enzymatic isolation yielded 4-5 times more living undifferentiated (CE) cells. The highest dynamics of in vitro growth was observed in primary cultures in low-calcium medium supplemented with the above substances. After 20 population doublings cells were differentiated and died. Only few cells on collagen membranes adhered to the collagen but did not enter division. CONCLUSIONS: Current research allowed for determination of methodology for CE excision and isolation. Optimal conditions for in vitro growth have been established. Growth dynamics and proliferation of CE in vitro have been evaluated. Growth of CE on standard collagen membrane has not been observed.

Animals↗
PubMed1999

Lovastatin induces mitotic abnormalities in various cell lines.

We examined the effects of lovastatin, a common anti-atherosclerotic drug and a blocker of the cell cycle, on the process of mitosis. It is known that lovastatin induces an arrest or a retardation of the cell cycle in many cell types not only at the G(1)phase, but also at the G(2)/M transition. After 24-48 h incubation of epithelial PtK(2), T24, HeLa cells and fibroblastic L929 cells in the presence of 1. 0-60.0 microm lovastatin, diverse mitotic perturbations have been observed. The most noteworthy phenomena recorded were prometaphase retardation and chromosome lagging during metaphase and anaphase. After the recovery in lovastatin-free media, the cells continued mitosis without any disturbances. Mevalonic acid prevented the effects of lovastatin. We conclude that the effects were specific for lovastatin-induced inhibition of mevalonic acid synthesis. Immunofluorescence studies with anticentromeric antibodies suggested that one of the possible causes of the lovastatin-induced mitotic disorder could be an interference with the development and function of the centromeres.

Anticholesteremic Agents↗
PubMed1999

The effects of B-sitosterol (BSS) and B-sitosterol glucoside (BSSG) mixture on selected immune parameters of marathon runners: inhibition of post marathon immune suppression and inflammation.

A pilot study was undertaken to investigate the effects of the intake of capsules containing the plant sterols and sterolins (BSS:BSSG mixture) on selected immune parameters of volunteers participating in an ultra-marathon in Cape Town, South Africa. Those runners having received active capsules (n=9) showed less neutrophilia, lymphopenia and leukocytosis when compared to their counterparts having received placebo capsules (n=8): the placebo treated individuals showed significant increases in their total white blood cell numbers as well as in their neutrophils (p=0.03 and 0.03 respectively). Furthermore, statistically significant increases within lymphocyte subsets were observed in the runners having received the active capsules: CD3+ cells increased (p=0.02) as did CD4+ cells (p=0.03). In parallel, the BSS:BSSG capsules decreased the plasma level of IL6 in the runners using the active capsules (p=0.08) and significantly decreased the cortisol: DHEAs ratio (p=0.03), suggesting that these volunteers had less of an inflammatory response and were less immune suppressed during the post-marathon recovery period. These findings justify further investigations into the use of the phytosterols to prevent the subtle immunosuppression associated with excessive physical stress.

Adult↗
PubMed1998

[Morphological characteristics of epithelial cell line from rat cornea].

PURPOSE: Morphological characteristics of established cell line (RtCE) derived from rat anterior corneal epithelium. MATERIAL AND METHODS: Morphology of cultured RtCE cells was evaluated by light and electron microscopy. Anterior corneal epithelium of rat served as control. RESULTS: Both in light and electron microscope we observed morphological similarity with anterior corneal epithelium (several layers of cells, numerous desmosomal connections). Moreover, similar morphological changes were observed in relation to the control material, i.e. degeneration and flattening of cells in superficial layers. CONCLUSIONS: The morphological analysis of RtCE cell line proves its usefulness for further cytomorphological, cytogenetical and functional analyses, as well as for evaluation of influence of different physico-chemical and biological factors on growth and regeneration of corneal epithelium in vitro.

Animals↗
PubMed1997

Doing What Everybody Does? A Procedure for Investigating Behavioural Synchronization

Behavioural synchronization means that the behaviour of several individuals is related in time. They may show the same behaviour either at the same time (synchrony) or explicitly at different moments (anachrony). Here, a procedure is presented, which not only allows quantitative investigation of behavioural synchronization in groups of any size, but also a separate evaluation with respect to each individual and behaviour pattern. The method distinguishes between the purely descriptive degree of concurrence and the degree of synchrony, which takes into account synchrony or anachrony occurring by chance on the basis of particular behaviour frequencies. Some recommendations for the application of the procedure are given and its limitations discussed. Copyright 1997 Academic Press Limited

Journal Article↗
PubMed1997

Fibromyalgia as a disorder of perceptual organization? An analysis of acoustic stimulus processing in patients with widespread pain.

We examined to what extent patients with fibromyalgia differ from painfree control subjects in the perception and processing not only of somatosensory but also of external stimuli. For this purpose the acoustic perception of 30 patients with fibromyalgia was compared with that of 36 generally pain-free age and gender matched subjects. The groups were also controlled for organic disease of pathological dysfunction of the ear and auditory nerves. Thresholds of unpleasantness and hearing thresholds were determined autiometrically for various frequencies. In addition the participants rated their experience of daily noise, vulnerability to acoustic stress, and functional and affective complaints associated with fibromyalgia. As expected the results show reduced unpleasantness thresholds for all frequencies and a nonsymptomatic hearing loss for higher frequencies. The elevated hearing threshold correlated significantly with experience of noise at the place of work, which was also elevated in the fibromyalgia group. Generalized pain had a high impact on the interaction between threshold of unpleasantness and daily noise experience. We interpret the differences in thresholds of hearing and of unpleasantness in patients with fibromyalgia as a form of either preconscious or conscious acts to protect against disturbing stimulation. Our results support the notion of a generalized disturbancy of perceptual thresholds in patients with fibromyalgia not restricted to the perception of pain.

Adult↗
PubMed1996

[Coping with stress and self-awareness in idiopathic sudden deafness].

In the work presented here patterns of stress management and self awareness of patients with sudden hearing loss (n = 50) are studied and compared to a control group. Private self awareness is conceived as a moderator of stress management. Data analysis was performed with special consideration given to gender specificity of patterns investigated. The profile of stress management in patients with sudden hearing loss differs from control groups. As for stress management, gender specific data analysis reveals for male as well as for female patients significant differences when compared to control groups. Beyond that, profiles of stress management differ between males and females. Furthermore, private self awareness in patients with sudden hearing loss exhibit significant differences in mean values when compared to control groups, which is interpreted as a reflection of a lower prevalence of private self awareness. However, gender specific analysis supports this initially significant result only to have tendentious character. With respect to preventive treatment and prophylaxis of relapse, our results suggest that training in stress management should be completed by bodily oriented procedures suited to enhance the perception of body signals.

Adaptation, Psychological↗
PubMed1996

Ubiquitin-mediated proteolysis centers in HeLa cells: indication from studies of an inhibitor of the chymotrypsin-like activity of the proteasome.

HeLa cells growing in vitro were treated with the peptidyl aldehyde inhibitor of the chymotrypsin-like activity of the proteasome N-benzyloxycarbonyl-Ile-Glu(O-t-butyl)-Ala-leucinal (PSI). Immunofluorescence studies of treated cells revealed the formation of massive perinuclear aggregates rich in ubiquitin and proteasomal antigens, which on the ultrastructural level appeared as perinuclear aggregates of electron-dense material, usually in the vicinity of Golgi cisternae. Histochemical studies disclosed that these cells contained protein-rich perinuclear aggregates detected by amido black staining, while unusual accumulations of lipids, carbohydrates, or nucleic acids were not present. Inhibition of protein synthesis by cycloheximide prevented the formation of aggregates, whereas microtubule disruption by nocodazole induced a dispersion of the aggregates. We hypothesize that aggregates induced by PSI treatment correspond to accumulations of proteasome-substrate complexes in a well-defined region, where the proteolytic processes of the ubiquitin-proteasome pathway seem to be somehow centered. We propose to call this region the proteolysis center.

Blotting, Western↗
PubMed1994

[Autologous transplantation of nasal mucosa after severe chemical and thermal eye burns].

BACKGROUND: Extensive conjunctival scarring is common after severe chemical and thermal eye burns. There is often not enough healthy conjunctiva from the other eye available to correct the symblepharons, therefore other autologous tissues have to be transplanted. PATIENTS AND METHODS: From February 1992 until March 1993 13 patients were treated with free nasal mucosal grafts from the inferior turbinates for reconstruction of the fornices. The newly created deep fornices were secured by a silicone band. In 3 patients an Illig plastic shell was used additionally. The surgical treatment was supplemented with an intensive treatment with topical corticosteroids to decrease the inflammatory reaction. RESULTS: The patients were followed for an average of 7-18 months. The interval between the accident and the transplantation ranged from 2-26 months. In 10 patients a reconstruction of the fornices was achieved. In all patients, however, some slight scars could be observed. Postoperative Schirmertest was markedly improved. These results encourage us to plan a penetrating keratoplasty in 7 cases. 3 patients showed a recurrence of the symblepharon 2 months after the transplantation. CONCLUSION: The nasal mucosa graft material is best suited for repair of extensive symblepharon. The advantages of this tissue are the availability of large pieces of mucosa and the transplantation of intraepithelial goblet-cells. Long-term effects are the improvement and stabilisation of the tear film.

Adolescent↗
PubMed1994

[Advantages of ENT-specialty-specific autopsy technique].

At routinely performed autopsies as described by Hamperl in 1956, ENT-specific regions such as the naso- and mesopharynx usually remain untouched. However, in cases with pathological changes in these regions a topographical preparation is necessary. Moreover, there is great interest among ENT-surgeons for studying the pathology of this area and to practice endoscopic and microscopic operation techniques. In close cooperation with the pathologists at RWTH clinic, we re-examined and refined further an ENT-specific dissection technique that was first described by Gräff in 1932. It allows a complete en bloc resection of all ENT-relevant organs without disfiguring the body. It also provides an optimal anatomical overview and gives insight into interrelations of morphological findings (thus improving post-mortem diagnosis), as well as allows the possibility for practicing operative techniques apart from the corpse.

Autopsy↗
PubMed1992

Ascaris lumbricoides: an unusual cause of shunt infection.

Two cases of delayed shunt infection attributable to the abdominal complications of Ascaris lumbricoides infestation are reported. The first child presented with a peritoneal shunt catheter protruding through the anus and the second patient was found to have two live worms around the cephalic shunt tubing. Both had enteric shunt infections which responded well to therapy. The epidemiology and treatment of ascariasis are briefly discussed.

Animals↗
PubMed1992

Laryngologic aspects of bolus asphyxiation-bolus death.

Among 12,982 forensic autopsies, 78 cases of café coronary due to bolus impaction in the larynx (bolus death) were observed from 1947 to 1988. In all cases bolus material occluded the entry to the larynx; only once was a singular occlusion of the glottis observed. The bolus frequently extended into the mouth, trachea, and bronchial tree or esophagus. In all cases small amounts of aspirated material were observed in the deeper parts of the bronchial tree. The most commonly observed bolus was not masticated meat or a meat product. In adults and the elderly the bolus was often too large to pass the physiological narrowings of the hypopharynx. It was commonly lodged above the arytenoid cartilages. Forty-five of the bolus events were observed by bystanders. In 43 of the victims vital reactions were observed by bystanders or at the autopsy. This justifies the hope that many lives could have been saved had the right diagnosis and immediate therapy been initiated. The first step should be manual extraction or use of the Heimlich maneuver; in cases of failure of both attempts, immediate tracheotomy followed by hospitalization and bronchial lavage are indicated.

Adolescent↗
PubMed1992

[Identification and removal of orbital foreign bodies using the CAS (Computer-Assisted-Surgery) system].

Identification and extraction of orbital foreign bodies can cause problems in special cases. Small, retroocular localized fragments can be hard to detect, severe bleeding and traumatically damaged anatomy can render orientation difficult. At the Department of Otolaryngology, Plastic Head and Neck Surgery of Aachen University Hospital we used the investigational new CAS (Computer-Assisted-Surgery) device in several such cases with good success. CAS is a new localizing technique designed to assist the head and neck surgeon during surgery providing real-time position information. The method is based upon a three dimensional volume model of the patient's skull generated by preceding computed tomography imaging procedures such as CT or MRI scan. Intraoperative correlation of 3D-model and the patient's skull allows for real-time position display of a surgical instrument on the monitor screen. Accuracy of the method has been experimentally determined to be within 1 mm. Thereby the surgeon is able to localize even small foreign bodies without extensive exploration. In the case of multiple foreign bodies the surgeon gets a simple documentation facility, which of the visible fragments have already been extracted. Medially placed foreign bodies could be removed via an endonasal approach. Encouraged by these results we recommend CAS for the extraction of orbital foreign bodies.

Accidents, Occupational↗
PubMed1992

[Experimental study of airflow in the main nasal cavity of the human using a nose model].

Airflow patterns of nasal cavities in a human nasal fossa model were examined in this study. Our 1:1 model of the whole nose (both nasal fossae were moulded) gives a good insight into all parts of the nasal cavities. Staining of flow paths visualised that the main stream of air flow passes through the inferior nasal duct in inspiration and expiration. All regions of the nasal fossa were reached by fluid movements and could be marked with staining solution. Under static conditions laminar flow without turbulent profiles was seen in all sections of the nasal cavities. This technique of detection of flow characteristics in the nasal cavities provides a good tool for further research on flow and deposition characteristics of aerosols.

Humans↗