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Biomedical subjects

R Friedrich

Publications and source records attributed to R Friedrich.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Intra-epithelial neoplasia of the vulva and smoking].

VIN III etiology is multifactorial with a predominant role held by human papillomavirus infections, especially infections with HPV type 16. Other cofactors are also involved. We reviewed our patients presenting with VIN III, focusing our attention on smoking. Out of 37 patients 29 (78%) were smokers and among those who presented with a relapse after treatment (11 patients) all were smokers. We discuss mechanisms by which tobacco could act as a cofactor in VIN III.

Adult↗
PubMed1992

[Cyclosporin A in therapy of chronic uveitis].

48 patients with chronic severe uveitis of pressumed noninfectious origin resistent to corticosteroids have been treated with Cyclosporin A. All patients had an initial loading dose of 5 mg/kg/day followed by a dose reduction according to ocular inflammatory activity and tolerability and according the guidelines by BenEzra, Nussenblatt and Timonen. Most of the patients received additional corticosteroids in a low dose. 35 out of these 48 patients (13 suffering from intermediate uveitis, 11 from retinal vasculitis, 5 panuveitis, 4 "pressumed histoplasmosis" and 2 sympathetic ophthalmia) were treated for 1 year and observed after withdrawing of Sandimmun for at least 6 months. The majority of these patients have manifested a positive therapeutic response to Cyclosporine, in particular patients suffering from vasculitis, panuveitis and sympathetic ophthalmia. All 35 patients were treated before for a long time with steroids without success, 19 out of these 35 in addition with cytotoxic agents. The immunosuppressive effect of Cyclosporine was not permanent, frequently the inflammation relapsed on reduction of dosage or withdrawing of the drug. Guidelines for combined regimen (Cyclosporine and corticosteroids and vitrectomy) were given. Although a large variety of side effects were reported the compliance was good.

Administration, Oral↗
PubMed1992

Ocular toxoplasmosis: the role of cellular immune defense in the development of recurrences. Results from animal experiments.

Five toxoplasmosis-free animals and ten animals that had been immunized intraocularly against toxoplasma organisms were used in a rabbit model of ocular toxoplasmosis. Five of the ten immune animals were immunosuppressed by cyclosporin A at a cellular level. Experimental toxoplasmic retinochoroiditis occurred in all animals, a process that in complete contradiction to experience reported previously. In the rabbit model, immunity after a past history of toxoplasma infection has thus far appeared to be a safe form of protection from experimental ocular toxoplasmosis. The concept of "immunological privilege of the eye" is discussed as the cause for the unexpected results.

Animals↗
PubMed1991

Construction and properties of an "artificial" spleen focus-forming virus.

The replication-defective Friend spleen focus-forming virus (F-SFFV) induces acute erythroblastosis in adult mice. The envelope-related (env) gene and LTR are the only functional elements of the viral genome. The env-coded glycoprotein gp55 has been shown to be responsible for target cell specificity and for the short latency of the disease caused by SFFV. This molecule closely resembles the env coded proteins gp70 + p15E of mink cell focus inducing viruses (MCFV). The only substantial differences between these two env genes are a large deletion spanning 585 nucleotides in the middle of the F-SFFV gene and a frameshift mutation near the 3' end leading to a modified and shortened membrane anchor in the mature protein. To determine if the large deletion and/or the frameshift mutation are capable of changing the properties of a nonpathogenic MCFV into those of an acutely pathogenic SFFV we introduced these changes into the env gene of an MCFV. The results show that the mutated MCFV is as acutely pathogenic as F-SFFV. We therefore conclude that the modified membrane anchor of gp55 and the change caused by the large deletion are the essential determinants of the high pathogenicity of SFFV.

Animals↗
PubMed1990

Sequence analysis of amphotropic and 10A1 murine leukemia viruses: close relationship to mink cell focus-inducing viruses.

Viral interference studies have demonstrated the existence of four distinct murine leukemia virus (MuLV) receptors on NIH 3T3 mouse cells. The four viral interference groups are ecotropic MuLV; mink cell focus inducing virus (MCF); amphotropic MuLV; and 10A1, a recombinant derivative of amphotropic MuLV that uses a unique receptor but also retains affinity for the amphotropic MuLV receptor. We report here that 10A1 infects rat and hamster cells, unlike its amphotropic parent. We isolated an infectious molecular clone of 10A1 and present here the sequences of the env genes and enhancer regions of amphotropic MuLV and 10A1. The deduced amino acid sequences of amphotropic MuLV and 10A1 gp70su are remarkably similar to those of MCF and xenotropic MuLV (for which mouse cells lack receptors), with 64% amino acids identical in the four groups. We generated a consensus from these comparisons. Further, the differences are largely localized to a few discrete regions: (i) amphotropic MuLV has two short insertions relative to MCF, at residues 87 to 92 and 163 to 169, and (ii) amphotropic MuLV and MCF are totally different in a hypervariable region, which is greater than 30% proline, at residues approximately 253 to 304. 10A1 closely resembles amphotropic MuLV in its N terminus but contains an MCF-type hypervariable region. These results suggest the possibility that receptor specificity is localized in these short variable regions and further that the unique receptor specificity of 10A1 is due to the novel combination of amphotropic MuLV and MCF sequences rather than to the presence of any novel sequences. The Env proteins of ecotropic MuLV are far more distantly related to those of the other four groups than the latter are to each other. We also found that the enhancer regions of amphotropic MuLV and 10A1 are nearly identical, although 10A1 is far more leukemogenic than amphotropic MuLV.

Amino Acid Sequence↗
PubMed1990

[Alternatives to steroid therapy in chronic uveitis].

In a search for alternative therapeutic methods other than corticosteroids and cytostatics, the effect of a dialyzable leukocyte extract (DLE), the antimetabolite 5-fluorouracil and the immunosuppressive agent cyclosporin A in corticosteroid-resistant idiopathic uveitis was studied. When DLE was administered to 26 patients who had uveitis forms with exogenous triggering (e.g., infection), as well as forms with an autoimmune background, there was a reduction in the number and duration of recurrences and a statistically proven prolongation of the inflammation-free intervals. This was particularly true in anterior and posterior uveitis and to a lesser extent in the intermediate form. No side effects were observed. 5-Fluorouracil, injected subconjunctivally, is indicated in intermediate uveitis with marked vitreous infiltration and beginning proliferation. Corneal erosion occurs relatively often. During treatment with cyclosporin A (low dose, 5 mg/kg of body weight per day), 14 of 17 patients (9 with intermediate uveitis, 6 with retinal vasculitis, 1 with sympathetic ophthalmia, 1 with panuveitis) showed improved results; in 2 cases the findings remained stationary and only 1 case had low-grade deterioration. If one takes into consideration the fact that in this patient any therapy would have failed, the results are convincing. This is particularly true of retinal vasculitis. There is no effect in cases of central hemorrhagic chorioretinopathy. So far, there have been no serious side effects.

Adrenal Cortex Hormones↗
PubMed1989

[The effect of a subretinal injection of Toxoplasma gondii on the serum antibody titer in a rabbit model of ocular toxoplasmosis].

A single subretinal injection of RH toxoplasma initiated an experimental toxoplasmosis of the eyes in big chinchilla rabbits. This animal model was used to study the development of the serum IgG level against toxoplasma. As a rule, the specific antibody level rose between the 9th and the 20th day following injection. At that time, the peak of inflammation had already been exceeded. An influence of cyclophosphamide0 or complete Freund's adjuvant on the humoral immune response of the animals to toxoplasma could not be detected. An attempt is made to interpret the findings deviating from the toxoplasmosis of the human eye.

Animals↗
PubMed1987

Isolation and characterization of cDNA clones encoding the human carcinoembryonic antigen reveal a highly conserved repeating structure.

For the isolation of cDNA clones encoding the carcinoembryonic antigen (CEA), we have constructed a cDNA library from human colon tumor mRNA. The library was screened with various oligonucleotides whose sequence had been deduced from partial amino acid sequence data for CEA. Positive candidate clones were hybridized with a probe for repetitive DNA, because CEA mRNA contains an Alu repetitive element, and with a fragment of a genomic clone of nonspecific cross-reacting antigen, an antigen closely related to CEA. Here we report the nucleotide sequence of the two overlapping CEA cDNA clones comprising 1422 nucleotides of CEA mRNA. This sequence encodes the 372 COOH-terminal amino acids of CEA followed by 305 nucleotides of 3' untranslated sequence containing a truncated Alu repeat. The predicted protein sequence is composed of two repeats comprising 178 amino acids, each with an exceptionally high homology of 67%. Each repeat unit contains four conserved cysteine residues and six to nine putative N-glycosylation sites. CEA mRNA is most strongly expressed in primary colon tumors and, to a lesser extent, in normal colonic tissue. No CEA mRNA is found in HeLa cells and normal human fibroblasts.

Adenocarcinoma↗
PubMed1986

Measurements of retinal microcirculation in retinal vessel occlusion before and after treatment.

Blood flow, arterial velocity, and vascular diameter were measured in patients with retinal vessel occlusion before and after treatment, especially after light coagulation. The mean values in the patient group showed significantly reduced blood flow and velocity compared to the normal group. The mean group difference before and after therapy revealed that while there is an increase in blood flow after treatment, the normal value is not reached. Individual patient values indicated both increased and decreased blood flow and velocity after treatment as compared with the values before therapy. There are various stages in microcirculatory disease and the microcirculation also behaves differently after treatment, which could be observed by measurement in vivo of the physiological flow parameters.

Adult↗
PubMed1986

[Clinical interpretation of retinal circulatory measurements. II. Blood flow].

Beginning as early as the mid-4th decade of life, an age-dependent reduction in retinal blood flow has to be considered an essential risk factor for disorders of retinal microcirculation. Blood flow measurements are a valuable, but not the sole criterion of microcirculatory disorders. While in retinal occlusive diseases blood flow is a valuable indicator of the severity of microcirculatory disorders, the latter can also occur in the presence of normal and elevated blood flow values. Shifts of the metabolic activity of the retina and changes in the metabolic activity of the retina and changes in the metabolic conditions have to be taken into account when a clinical interpretation is given.

Diabetic Retinopathy↗
PubMed1986

[Clinical interpretation of retinal circulatory measurements. III. Blood flow velocity and vessel diameter in normal persons and in patients with venous occlusive diseases].

Based on results from measurements of arterial blood velocity, arterial and venous diameters of major segmental retinal vessels in normal persons and in patients with venous occlusive diseases and in continuation of the two preceding parts of this series of articles, further possibilities for the differential diagnosis of measurements of retinal microcirculation magnitudes are discussed. Whereas the measurement of blood velocity is an important criterion for the assessment of the stasis conditions and the arterial involvement in an occlusive disease, the diameters of the vessels offer essential suggestions to local regulative processes. In this connection, a dependence on pH of the contraction state of the smooth vascular musculature detected in porcine coronary arteries is presented. By its transmission to the arterial retinal vessels, it is possible to unequivocally clarify the local regulative and pathological behavior of arterial retinal vessels in terms of flow physiology.

Blood Flow Velocity↗
PubMed1986

Diffuse colonic varices: an uncommon cause of intestinal bleeding.

Varices of the colon are uncommon and when present they are usually segmental. The cause of these segmental varices is usually portal hypertension. Diffuse variceal involvement of the colon is even more uncommon and up until now the two cases described in the literature have had an idiopathic etiology. We describe herein the third such case, while pointing out that the diffuseness implies an unknown cause.

Adult↗