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Biomedical subjects

A Gorski

Publications and source records attributed to A Gorski.

At least 19 recordsLinked to original sources
PubMed2002

Mutations in bacteriophage T4 genome.

Bacteriophage (phage) T4 belonging to T-even phages is one of the best known phages with a completely deciphered genome sequence. As a model of living systems, T4 phage has many technical advantages. It can be very easily grown in large quantities, manipulated by classical genetics, and engineered by site-directed mutagenesis. Many substances have been first tested for mutagenicity in T-even phages. The results of these tests were very often applicable to higher organisms due to similar mechanisms of mutagenesis. T4 phage is also important in phage therapy, which represents an alternative treatment of bacterial infections since the bacterial resistance to antibiotics has become a serious medical problem. The site-directed mutagenesis is a method that enables to introduce mutations which can influence phage affinity to bacteria and can be a practical technique for enriching phage collections and for widening specificity of phages for new bacterial strains now insensitive to phage therapy.

Bacteriophage T4↗
PubMed2001

Vibrations of the phenoxyl radical.

Phenoxyl radical (C(6)H(5)O) was prepared photochemically in low-temperature argon matrices. The infrared absorption spectra were obtained for C(6)H(5)O and for the isotopically labeled species C(6)D(5)O and 1-(13)C(12)C(5)H(5)O. All but one IR-active fundamental vibrations were detected, most of them not previously observed. Combination of results from IR linear dichroism measurements on photooriented samples, determination of absolute IR intensities with the help of internal standards, analysis of isotopic shifts, and quantum chemical predictions (B3LYP/cc-pVTZ) led to a detailed assignment of phenoxyl radical vibrations. Significant frequency shifts are observed with respect to previously reported data based on resonance Raman studies in polar solutions. For some vibrations, these shifts reflect environment-induced structural changes, such as increase of the quinoid character of the phenoxyl radical in polar media. In particular, the frequency of the CO stretching vibration, readily observable in both IR and Raman experiments, is extremely sensitive to the environment and can thus be used to probe its polarity.

Free Radicals↗
PubMed2001

DNA profiling of trace evidence--mitigating evidence in a dog biting case.

A young girl was the victim of a severe dog attack. An animal, suspected of having caused the attack, was later impounded for investigation. Microclots of blood, recovered from the dog's fur, were analyzed by STR DNA. Results showed that this blood was not related to the biting. Other forensic evidence--hairs, fibers, and odontology--failed to connect a particular animal to the attack. The implications of these findings for the dog and its owners are discussed as well as other forensic methods for resolving such cases.

Animals↗
PubMed1999

Three different autoimmune bullous diseases in one family: is there a common genetic base?

We report an unusual familial occurrence of autoimmune bullous diseases. Three members of a family suffered from three different autoimmune bullous diseases: pemphigus vulgaris (PV), linear IgA disease (LAD) and cicatricial pemphigoid (CP). The HLA type was determined in five family members: all were positive for HLA-DQ5/DR6, which is reported to be associated with susceptibility to PV. The CP patient was DQ7(3) positive, which is in concordance with enhanced susceptibility to ocular CP and CP. The LAD patient was B8 and DR3 negative but positive for HLA-A1. Our study supports the hypothesis that there is a genetically transmitted susceptibility to autoimmune bullous diseases but that additional factors seem necessary actually to develop a particular disease.

Adult↗
PubMed1998

T cell interactions with extracellular matrix proteins in patients with thyroid-associated ophthalmopathy.

Although thyroid-associated ophthalmopathy (TAO) is now generally accepted as an autoimmune inflammatory disorder of the extraocular muscles and the orbital connective tissue, its aetiopathogenesis remains poorly understood. Recent data indicate that impaired interactions between T cells and extracellular matrix (ECM) proteins may play an important role in development and maintaining of an inflammatory process. We report here results of the study focusing on interactions between T lymphocytes and collagen-I (Coll-I), collagen-IV (Coll-IV), fibronectin (FN), laminin (LM) in patients with TAO. Using a standard peripheral blood mononuclear cells (PBMC) proliferation assay, we observed a markedly enhanced T cell response to Coll-I in patients with active TAO (mean SI=4.5). The proliferatory response to Coll-I was significantly greater (Wilcoxon test; p < 0.001) than in normal subjects (mean SI=1.88), patients with stable TAO (mean SI=2.05) and patients with thyroid autoimmune diseases (AITD) without ophthalmopathy (mean SI=2.49). PBMC stimulation by Coll-I is likely to be antigen-dependent requiring engagement of the T cell receptor with collagen peptides, rather than mediated via integrins. The percentage of circulating CD29+ (beta1 integrin chain) T cells was not increased in patients with active TAO. Additionally in the assay of costimulation of CD3-mediated proliferation, we found that peripheral blood T cells from patients with TAO and AITD were costimulated only by FN. On the other hand a markedly enhanced costimulation of CD3-mediated proliferative responses by Coll-I, Coll-IV, FN and LM were observed in a retrobulbar T cell line. We conclude that abnormalities in T cell interactions with ECM proteins, especially Coll-I may play a role in the pathogenesis of TAO.

Adolescent↗
PubMed1995

Excessive costimulation of CD3-dependent lymphocyte response by extracellular matrix proteins in severe widespread psoriasis.

Costimulation of anti-CD3-triggered proliferative T-cell responses by type I and type IV collagen and fibronectin was studied in 25 patients with psoriasis and 12 healthy subjects. The stimulation index of anti-CD3-mediated responses in the presence of type I collagen was about half that in the controls. Although the CD3-dependent proliferative response of psoriatic lymphocytes in patients with active widespread plaque psoriasis was reduced by about 50%, costimulatory responses induced by type IV collagen and fibronectin were found to be enhanced in relation to the controls. The degree of costimulation by type IV collagen and fibronectin was related to disease severity. The highest values of the stimulation index were found in patients with a PASI greater than 24, skin involvement of more than 40% of body surface area, and a duration of psoriatic lesions of more than 3 months. The results indicated that in active widespread plaque psoriasis subpopulations of T cells bearing receptors for some extracellular matrix proteins were increased in the peripheral blood. A factor responsible for this phenomenon may be trafficking of T cells through the basement membrane zone of psoriatic lesions, which presumably causes modification of T cell immunological responsiveness after recirculation.

Adult↗
PubMed1995

Modulation of CD3-dependent lymphocyte proliferation by extracellular matrix proteins in atopic dermatitis.

Patients with atopic dermatitis were found to have an about 7-fold increased spontaneous proliferative response of peripheral blood lymphocytes and an about 4-fold elevation of CD3-dependent lymphocyte transformation as compared to normal controls. The CD3-dependent lymphocyte response in patients with severe atopic dermatitis lesions was increased to a lower degree than in those with mild skin lesions. Despite a highly increased CD3-dependent lymphocyte response, the extracellular matrix proteins could induce further co-stimulation of lymphocytes in patients with atopic dermatitis, similar to that in normal controls. However, co-activation by type IV collagen was markedly increased in patients with severe lesions, whereas co-stimulations by both type I collagen and fibronectin were decreased in patients with mild lesions. This finding reflects presumably the changes in lymphocyte subpopulations and their activities related to the recirculation of these cells through the active skin lesions and to the contact of T cells with extracellular matrix proteins. The percentage of CD26-positive lymphocytes was also significantly (p < 0.05) increased in patients with severe atopic dermatitis. These data indicate that helper T cells are excessively activated in atopic dermatitis and that the function of beta-1-integrin receptors underlying the extracellular matrix protein-mediated co-activation of CD3-dependent lymphocyte responses is modified by disease severity.

Adolescent↗
PubMed1994

Wall hangings, hairs and the Holocaust.

Two wall hangings, from the time of the Second World War, were reportedly made from human hair. Laboratory examination of the hangings confirmed this fact. Fibers, holding the wall hangings together, and the weave of the hangings were also examined. Results and implications of the findings are discussed.

Animals↗
PubMed1986

Abnormal B-cell function in hemophiliacs treated with cryoprecipitate and factor VIII and IX concentrates.

B-Cell function was evaluated in a group of 43 patients with factor VIII or factor IX deficiency. Thirty had been treated primarily with cryoprecipitate and 13 with concentrates of factor VIII or IX. Serum immunoglobulin G levels were found to be diffusely elevated; however, the absolute number of mature B cells in peripheral blood was normal. B-Cell function as measured by testing mitogen-induced proliferation and and immunoglobulin secretion by plaque-forming cells (PFC) in vitro was reduced. Coculture experiments suggested that these abnormal B-cell responses might be secondary to increased suppressor T-cell activity, which was found more frequently in patients seropositive for antibody to lymphadenopathy-associated virus. Both seronegative and seropositive patients had reduced responses in the proliferative and PFC assays, but the lowest PFC responses occurred in the seropositive group.

Adolescent↗
PubMed1984

Inhibition of human B lymphocyte differentiation by a stable metabolite of cyclophosphamide (ASTA Z 7557, INN mafosfamide).

We have evaluated the immunosuppressive effect of a new stable derivative of cyclophosphamide (ASTA Z 7557) on human lymphocyte immunoglobulin biosynthesis in vitro. When graded amounts of the drug are added to lymphocyte cultures stimulated with the helper T cell-dependent activator (PWM), a marked inhibition of B cell proliferation and differentiation occurs. Lymph node cells are particularly sensitive to the drug, while splenocytes are relatively resistant. The agent exerts only a minor effect on immunoglobulin synthesis triggered by a direct B cell stimulant (S. paratyphi bacteria).

B-Lymphocytes↗