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Biomedical subjects

M Giese

Publications and source records attributed to M Giese.

18 recordsLinked to original sources
PubMed2002

[Abnormalities of the maxillary sinus in type 1 neurofibromatosis].

AIM: The aim of this study was to determine the malformations of the maxillary sinus in neurofibromatosis type 1 patients (NF1). MATERIAL AND METHODS: Twenty-two patients with NF1 were investigated clinically and radiologically: 11 had an unilateral trigeminal plexiform neurofibroma and 11 had multiple cutaneous neurofibromas. The histological type of NF was ascertained in all cases following tumor resections. The malformation of the maxillary sinus was assessed on plain radiographs and computed or magnetic resonance tomograms. Intraindividual side comparison was used to judge the size of the sinus and its position in the midface. RESULTS: In patients with cutaneous neurofibromas the maxillary sinus appeared symmetrical in size and position. The pneumatization of the sinus had no abnormalities on the radiographs. Malformations of the maxillary sinus were restricted to plexiform neurofibromas. On the side affected by a plexiform NF, the sinus appeared hypoplastic and caudally displaced due to an enlarged ipsilateral orbit. The expansion of the sinus to the lateral side was impaired, obviously due to tumor masses. Consecutively, the alveolar process of the affected side was also displaced leading to a complex malocclusion. DISCUSSION: Malformations of the face are frequently presented as case reports in the literature. Emphasis is given to the elephantiasis-like tumor growth of the face in certain patients with NF1. The underlying pathology has not yet been fully understood. This report provides evidence that in the midfacial region the overgrowth is predominantly caused by the plexiform neurofibroma itself and that the bones can even be hypoplastic and show scoliosis-like malformation compared to the nonaffected side. These findings are relevant when debulking procedures of the face are planned for NF1 patients.

Adolescent↗
PubMed2002

Stable and long-lasting immune response in horses after DNA vaccination against equine arteritis virus.

Equine arteritis virus (EAV) is the causative agent of the equine viral arteritis. It is a small RNA virus with a linear, non-segmented plus RNA genome. EAV is a member of the Arteriviridae family that includes porcine reproductive and respiratory syndrome virus (PRSSV), simian haemorrhagic fever virus (SHFV) and lactate dehydrogenase virus (LDV). The viral transmission is via respiratory and reproductive routes. Clinical signs in horses vary, and severe infection can lead to abortions in pregnant mares or neonatal foal death. The aim of this study was to investigate the development of the immune response in horses after immunization with a DNA vaccine harbouring and expressing EAV Open Reading Frames (ORF) 2, 5, and 7, in combination with equine interleukin 2 (eqIL2). Three boosters followed the basic immunization in two-week intervals. Each immunization was a combination of gene gun and intramuscular injection. All horses developed a high titer of neutralizing antibodies after basic immunization within 2 weeks. Remarkably, this immune response was found to be independent of the age of animals. The youngest horse was six-years old, and the oldest twenty-two years old. A remarkable difference in the immune response between the young and old were not observed. The duration of immunity was investigated during a period of one year. After 12 months, neutralizing antibodies were still detectable in all the vaccinated horses.

Animals↗
PubMed2001

Interferon gamma and prostaglandin in BSE-infected cattle.

Suspect field cases of BSE infection (displaying clinical signs) were examined for possible alterations of cytokine/autacoid plasma levels and were compared to control cases (not displaying clinical signs of BSE infection). Interferon gamma (IFN-gamma) plasma levels were demonstrated as being elevated in all suspected field cases of BSE infection (irrespective of BSE status; determined via postmortem histopathological examination). We demonstrated that plasma IFN-gamma levels were significantly (P<0.005) higher in suspect cases of BSE infection than in control cases. BSE-positive prostaglandin-E(2), (PGE(2)) plasma levels were demonstrated as being elevated 1.25-fold above BSE-negative cases and 2.22-fold above control cases. No significant (P>0.5) increase in PGE(2)plasma levels was recorded between BSE-positive and -negative. IFN-gamma and PGE(2)plasma levels were examined using commercially available ELISA assay. The results presented in this publication are the first demonstration of alteration in immune state in animals with BSE.

Animals↗
PubMed2001

Limitations of B-scan ultrasound for diagnosing fractures of the mandibular condyle and ramus.

The aim of this study was to analyse the applications and limitations of B-scan ultrasonography for diagnosing fractures of the mandibular condyle and ramus. Thirty-two patients with 39 radiologically proven fractures of the mandibular condyle and ramus were included in the study. The patients were examined with a 7.5 MHz small-part applicator. Five patients without fractures of the facial skeleton acted as controls. Normal sonoanatomical findings had been obtained for patients without mandibular fractures. B-scan ultrasonography enabled the experienced examiner to identify dislocated fractures of the mandibular ramus and the articular process in 67% of the fractures. The main disadvantage of ultrasonography was the inability of this technique to identify non-dislocated fractures. Because of its low sensitivity and specificity, B-scan ultrasonography does not provide an alternative to X-ray diagnosis of mandibular condyle and ramus fractures.

Adolescent↗
PubMed2001

[Detection of p53 mutation in mouth mucosa smears of patients with oral squamous epithelial carcinoma].

Tumour-suppressor gene p53 encodes for an important cell-cycle regulatory protein and is therefore probably important for the development of many malignant diseases, e.g. squamous cell carcinoma of the mouth. This gene has mutated most frequently in connection with the development of cancer, so it has been well explored. Hence we chose it to find out whether swabs of the oral mucosa are suitable for supplying material for the detection of mutations in a gene that is connected with the development of oral squamous cell carcinomas, because swabs are easier to obtain than biopsies. We examined biopsies, swabs from the tumour, and swabs from mucosa that appeared healthy from 32 patients with oral squamous cell carcinoma and mucosal swabs from 35 healthy persons with polymerase chain reaction (PCR) and temperature gradient gel electrophoresis (TGGE). Fourteen of the 32 patients with a tumour showed mutations of p53, and in all cases the mutation could be demonstrated both in the biopsy and in the tumour swab. In four cases the mutation was also found in the swab of normal mucosa. Our investigations revealed that swabs are a suitable method for obtaining material for the detection of gene mutations in oral squamous cell carcinomas.

Adult↗
PubMed2001

Large envelope glycoprotein and nucleocapsid protein of equine arteritis virus (EAV) induce an immune response in Balb/c mice by DNA vaccination; strategy for developing a DNA-vaccine against EAV-infection.

Equine arteritis virus (EAV) is a member of the Arteriviridae family, that includes lactate dehydrogenase-elevating virus (LDV), porcine reproductive and respiratory syndrome virus (PRRSV), and simian haemorrhagic fever virus (SHFV). Equine arteritis is a contagious disease of horses and is spread via respiratory or reproductive tract. The objective of the present study is to evaluate the possibility for developing a model system for prevention horses against an EAV infection by DNAvaccination. A cDNA bank from the RNA of EAV was established. This gene library contains the translation unit of the EAV open reading frames (ORF) 1 to 7. The identity of the cDNA was confirmed by nucleotide sequence analysis. Using this defined EAV cDNA gene library the cDNA sequence of the viral ORFs were molecularly cloned into the corresponding sites of well characterized and powerful expression vectors (pCR3.1, pDisplay, and/or pcDNA3.1/HisC). The capability of these recombinant plasmids expressing the gene products of the individual viral ORFs 3 to 5, and 7 in induction of an immune response in mouse system was investigated. The Balb/c mice (ten mice per assay) were inoculated with the DNA of the constructed expression vectors harboring and expressing the EAV cDNA of the viral ORFs. The Balb/c mice were injected with about 100 microg DNA diluted in 100 microl PBS. The DNA was injected subcutaneously and into the tibialis cranialis muscle (Musculus gastrocnemius). The mice were boosted 3 to 5 times with the same quantities of DNA and under the same conditions at about two week intervals. Control mice received the same amount of parental expression vectors via an identical route and frequency. The pre- and post-vaccinated sera of the individual animals were screened by neutralization tests (NT). Neutralizing antibodies against EAV were detected when the animals were inoculated with the DNA of the expression vectors harboring cDNA of the EAV ORFs 5 and 7. Highest NT-titers were observed when the animals were administered with the cDNA of ORF 5 and/or with the cDNA of the neutralization determinants of EAV that is located on the N-terminal ectodomain of the gene product of ORF 5 between the amino acid positions 1-121. These results obtained from these studies justified proofing the capability of the EAV cDNA sequences of the viral genes including ORFs 5 and 7 in the autologous animal system horse.

Animals↗
PubMed2000

Uptake, toxicity, and effects on detoxication enzymes of atrazine and trifluoroacetate in embryos of zebrafish.

The uptake, toxicity, and elimination of atrazine and trifluoroacetate (TFA) were studied in early life stages of the zebrafish (Danio rerio). Furthermore, the effects of these xenobiotics on soluble (s) and microsomal (m) glutathione S-transferases (GST) of zebrafish embryos were investigated using 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), and [(14)C]atrazine. [(14)C]Atrazine was taken up by the embryos within seconds, unhindered by the chorions. It accumulated in the embryos by a factor of 19 after 24 h of exposure time. LC(50) (48 h) was determined at 36.8 mg/L. At a level of 5 mg/L atrazine, activities of s and m GSTs were elevated in most stages, especially in prim 6 and long pec stage (24, 48 h after fertilization, respectively). GST activity toward atrazine was detectable only in untreated D. rerio eggs, increasing with developmental time. [(14)C]Atrazine was eliminated from the embryos between 24 and 48 h, indicating a possible metabolism to a more hydrophilic GSH conjugate. [(14)C]TFA was taken up by embryos, reaching at maximum fivefold the concentration of the incubation medium after 10 h. The chorions served no physiological protection. TFA (1 g/L) caused low elevation of the GST activity. No acute toxic effects (48 h) were observed up to 4 g/L TFA.

Animals↗
PubMed1999

Parametric population representation of retinal location: neuronal interaction dynamics in cat primary visual cortex.

Neuronal interactions are an intricate part of cortical information processing generating internal representations of the environment beyond simple one-to-one mappings of the input parameter space. Here we examined functional ranges of interaction processes within ensembles of neurons in cat primary visual cortex. Seven "elementary" stimuli consisting of small squares of light were presented at contiguous horizontal positions. The population representation of these stimuli was compared to the representation of "composite" stimuli, consisting of two squares of light at varied separations. Based on receptive field measurements and by application of an Optimal Linear Estimator, the representation of retinal location was constructed as a distribution of population activation (DPA) in visual space. The spatiotemporal pattern of the DPA was investigated by obtaining the activity of each neuron for a sequence of time intervals. We found that the DPA of composite stimuli deviates from the superposition of its components because of distance-dependent (1) early excitation and (2) late inhibition. (3) The shape of the DPA of composite stimuli revealed a distance-dependent repulsion effect. We simulated these findings within the framework of dynamic neural fields. In the model, the feedforward response of neurons is modulated by spatial ranges of excitatory and inhibitory interactions within the population. A single set of model parameters was sufficient to describe the main experimental effects. Combined, our results indicate that the spatiotemporal processing of visual stimuli is characterized by a delicate, mutual interplay between stimulus-dependent and interaction-based strategies contributing to the formation of widespread cortical activation patterns.

Animals↗
PubMed1998

[Tumor reduction of plexiform neurofibroma in the craniofacial and neck area].

Neurofibromatosis type 1 (NF1) is an autosomal dominant hereditary disease of high penetrance and variable expression. Epidemiologic data on craniofacial manifestations are still lacking. Up until now 74 patients with NF1 have been treated at the Department of Oral and Maxillofacial Surgery of the University of Hamburg. Forty-two patients presented periorbital and orbital neurofibromas varying in extension and in the severity of findings of the affected site. Surgical therapy is mainly based on tumour reduction, frequently combined with face-lifting. In our experience neurofibromas of the neck tend to be pseudo-encapsulated, facilitating the preparation of the tumour. On the other hand, identification and preparation of diffuse infiltrating neurofibromas in the trigeminal nerve region are difficult and local recurrence must be expected.

Adult↗
PubMed1998

DNA-antiviral vaccines: new developments and approaches--a review.

Current vaccines can be divided into "live," "recombinant" and "killed" vaccines. Live vaccines are traditionally composed of attenuated viruses or bacteria, selected for their reduced pathogenicity. Recombinant vaccines, driven by a viral or bacterial vector express foreign antigens, or only recombinant proteins injected as antigen. Killed vaccines consist of inactivated whole pathogens. But all these traditional vaccines have some disadvantages: Attenuated live vaccine are able to undergo mutation and as mutated viruses or bacteria can now provoke the diseases against which the vaccine should protect the organism. A further disadvantage of live vaccines is the possibility of shedding which is a real problem especially in veterinary medicine. Clearly, there is a need for better vaccines to protect against diseases without the disadvantages associated with vaccines presently in use. Modern vaccines might be characterized as safe, no risk of reversion to pathogenicity, and they should be stable without the necessity of a "cold chain." Production should be simple, standardized and inexpensive. Vaccine development has now been improved by the ability to use direct inoculations of plasmid DNA encoding viral or bacterial proteins. One of the major benefits of DNA-vaccines, variously termed "DNA-, genetic- or nucleic acid-immunization," is the endogenous synthesis of the encoded protein. Therefore DNA vaccines mimic natural infection and provoke both strong humoral and cellular immune response. This review summarizes new developments and approaches of DNA vaccination and explains the construction of expression plasmids as well as possible mechanisms of immune responses.

Animals↗
PubMed1989

Role of interleukin 1 in mycoplasma mitogen-induced proliferation of human T cells.

Recently, a mitogenic effect of the supernatant of cultured mycoplasma arthritidis (MAS) on human and murine lymphocytes has been described. Here, we studied the role of accessory cells (AC) in MAS-induced T cell proliferation in a system of human leukocytes. Nylon-wool purified T cells were non-responsive to MAS with regard to both proliferation and IFN-gamma production. The capacity of T lymphocytes to respond to MAS could be restored when viable AC were added. Treatment of AC with UV light resulted in a cell population which was incapable of reconstituting T cells. Addition of human recombinant interleukin 1 alpha (IL 1 alpha) or IL 1 beta again showed a reconstituting effect. However, only a partial reconstitution of the T cell response could be achieved by addition of recombinant IL 1 alpha or IL 1 beta. The optimal restoration was achieved by adding IL 1 at a concentration of 100 U/ml IL 1 alpha or 100 U/ml IL 1 beta. The results indicate that metabolically active AC were required for MAS-induced T cell proliferation to occur and that IL 1 was able to substitute for the role of AC. Since this restoration was only partial, it remains to be determined whether factors others than IL 1 are required to fully substitute the role of accessory cells.

Antigen-Presenting Cells↗
PubMed1988

Blocking of interferon synthesis in murine macrophages by pretreatment with interferon.

The influence of pretreatment with interferon (IFN) on subsequent IFN synthesis was investigated in macrophage cultures of DBA/2 and C57BL/6 mice. The doses of IFN alpha/beta for pretreatment ranged from 10,000 U/ml to 100 U/ml and the incubation time was between 18 and 2 h. No blocking effect was observed for chemical induction with poly I:poly C or CMA. However, for viral infection with NDV, blocking was observed. This inhibition of IFN synthesis was dependent on the dose and time of IFN pretreatment and of the titer of the inducing virus. Similarly in mouse fibroblast cultures no blocking activity was observed for induction with poly I:poly C/DEAE-dextran. Again, with NDV as inducer, pretreatment with IFN resulted in inhibition of interferon synthesis. Thus, our data show that blocking occurs only with a viral inducer and suggest that it is caused by an antiviral effect.

Animals↗
PubMed1988

[Interferons and their effects].

The interferon system is an integral part of the defense system of the body, mediating a large variety of biologic effects. Presently, three groups of interferons (IFN) are known: IFN alpha, IFN beta and IFN gamma. IFN alpha and IFN beta show homology on the nucleotide level of about 40-50%, and both IFNs bind to a common receptor. IFN alpha and IFN beta are produced after induction by leukocytes and fibroblasts. IFN gamma is, by definition, not only an interferon but also a lymphokine, since it is a product exclusively of lymphocytes. There is no homology on the nucleotide level between IFN gamma and IFN alpha/beta. Furthermore, the receptor of IFN gamma is different from the receptor of IFN alpha/beta. IFNs are defined by their antiviral activity directed against a large number of different viruses. The target of IFN is the cell rather than the virus itself. Through binding on the cell surface and subsequent activation of specific genes IFNs induce an antiviral state which makes cells less permissive for virus replication. The antiviral state consists of various antiviral mechanisms. Among the non-antiviral effects of IFNs are the effects on cellular components of the immune system. Thus, one has postulated a role for interferons as immunoregulatory molecules. Interferons augment the expression of MHC-genes of which IFN alpha/beta only affect the molecules of class I, whereas IFN gamma affects both the molecules of class I and class II. Moreover, all IFNs increase the activity of macrophages and NK cells. Possibly the activation of components of the immune system is in part responsible for the antitumor effects of interferon.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1988

Contamination of a monoclonal antibody with LDH-virus causes interferon induction.

Interferon induction occurred unexpectedly during an in vivo study using a mouse monoclonal antibody. The interferon was typed alpha/beta and the titer reached a maximum at 24 hours in contrast with other inducers. Similar results were obtained with a virus pool derived from the antibody and with a LDV reference strain. MAP-testing of the monoclonal antibody revealed contamination with lactate dehydrogenase virus (LDV). The production of IFN seems to be controlled genetically. This experimental error demonstrates the importance of an appropriate quality control of biological materials.

Animals↗
PubMedDate not supplied

P53-mutation in smears of oral squamous cell carcinoma.

The tumor suppressor gene p53 encodes for an important cell cycle regulatory protein. Loss of the protein's function is probably important for the development of a variety of malignant diseases, including oral cancer. Up to present knowledge, the mutations of the p53 gene are one of the most frequent genetic alterations detectable in human cancer. The aim of this study was to explore the capability of molecular diagnostics to identify p53 mutations (exon 5-8) in smears of the oral mucosa (polymerase chain reaction, temperature gradient gel electrophoresis). Thirty two patients with oral squamous cell carcinoma comprised the study. Biopsies of the tumor, smears of the ulcer, and smears of apparently healthy mucosa were collected from these cancer patients. Smears of 35 healthy volunteers served as controls. P53-mutations were detected in 14 of the 32 cancer patients (44%). The same mutations was also detected in the biopsy in all cases. In addition, swabs of apparently normal mucosa harboured p53-mutated cells in 4 of these 14 patients. No mutation was found in healthy volunteers. Our investigation showed the suitability of swabs for gaining sufficient material to detect p53 gene mutations in oral squamous cell carcinoma.

Adult↗