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Biomedical subjects

U Kastner

Publications and source records attributed to U Kastner.

18 recordsLinked to original sources
PubMed2007

Distinct fluctuations of ammonia levels during asparaginase therapy for childhood acute leukemia.

BACKGROUND: The enzyme asparaginase (L-Asp) catalyses the hydrolysis of the non-essential amino acids asparagine and glutamine to aspartic and glutamic acid and ammonia. Ammonia therefore represents a direct metabolite of the biochemical reaction induced by this enzyme. However, data regarding the dynamics and clinical relevance of ammonia levels during L-Asp therapy are lacking. PROCEDURE: We prospectively followed the dynamics of ammonia levels during L-Asp containing induction therapy according to the ALL-BFM 2000 protocol in 10 pediatric patients with acute lymphoblastic leukemia (ALL), in order to assess the possible relevance of ammonia levels for clinical practice and its use as a possible surrogate parameter of L-Asp enzyme activity. RESULTS: We observed a significant elevation of ammonia levels 1 day after intravenous L-Asp administration with ammonia levels reaching up to the seventh fold of normal values, followed by a steep decline to basal values within another 2 days, resulting in an undulating course of ammonia concentrations during L-Asp containing induction treatment. CONCLUSIONS: Although there are potential neurotoxic properties of ammonia, central nervous system (CNS) toxicity has not been observed in our study and is generally not seen as a common side effect of L-Asp therapy. Furthermore, due to the characteristic fluctuation profile, ammonia levels may represent a suitable surrogate parameter of L-Asp enzyme activity and may enable the monitoring of silent inactivation of L-Asp.

Adolescent↗
PubMed2003

[Cryosurgery--the last resort or a surgical alternative in the treatment of lichen sclerosus et atrophicus of the vulva (LSAV)?].

BACKGROUND: The treatment of LSAV consists mainly of topical corticosteroids, progesterone or testosterone. Often these approaches neither improve the clinical findings nor relieve the symptoms. We evaluated cryotherapy as a possible therapeutic option. PATIENTS AND METHODS: Nine girls (age between 5 and 15 years, mean 9 years) and 22 women (age between 33 to 74 years, mean 54 years) with clinically and histologically confirmed LSAV were treated with cryotherapy. RESULTS: All patients experienced improvement of their clinical signs and symptoms. Five patients had a second cycle of cryotherapy after an average of 10,6 months; 2 women were treated a third time. CONCLUSIONS: Cryotherapy is an effective therapeutic option for LSAV. It has few side effects and seems to be an attractive alternative especially in children.

Adolescent↗
PubMed2002

[Acid oligosaccharides as the active principle of aqueous carrot extracts for prevention and therapy of gastrointestinal infections].

Adherence of microorganisms to the intestinal mucosa is an important and initial step in the pathogenesis of gastrointestinal infections and mediated by carbohydrate structures on the cell surface. Adherence can be blocked by carbohydrate receptor analogues. Aqueous extracts from carrots (carrot soup) contain acidic oligosaccharides, which are able to block adherence of various enteropathogenic microorganisms to HEp-2 cells and human intestinal mucosa in vitro. Dependent on the grade of polymerisation the most potent blocking ability was seen for trigalacturonic acid. Clinical studies revealed, that aqueous carrot extracts are significantly superior to the basic glucose-electrolyt-solution for oral rehydration in acute gastrointestional infections of children.

Bacterial Adhesion↗
PubMed2001

Pediatric visceral leishmaniasis in Austria: diagnostic difficulties in a non-endemic region.

Visceral leishmaniasis is usually fatal if left untreated. In Europe it is mainly caused by Leishmania infantum which is endemic in the whole Mediterranean region. While visceral leishmaniasis classically affects children, adults increasingly suffer infections in regions which are known to be endemic for HIV. Nowadays up to 70% of the patients with visceral leishmaniasis in southern Europe are HIV-infected adults. The diagnosis is known to be especially difficult to establish in this group of patients because of a frequently atypical clinical presentation, but even in non-HIV-infected patients visceral leishmaniasis often represents a diagnostic challenge particularly when the patient is living in a non-endemic region. We report on four children with visceral leishmaniasis diagnosed at St. Anna Children's Hospital, Vienna, in the last decade. Diagnostic difficulties arose (1) from inexperience with this rare disease, (2) from a long incubation period (6 to 8 months) and (3) from a travel history apparently unsuspicious for the contraction of what is considered a 'tropical' disease. In one case, specific problems resulted (4) from clinical appearance and laboratory data mimicking hemophagocytic lymphohistiocytosis. Consequently even in regions where leishmaniasis is not endemic, diagnostic efforts should be undertaken to rule out this disease especially in patients with the presumptive diagnosis of hemophagocytic lymphohistiocytosis.

Adult↗
PubMed2001

Influence of macrolide antibiotics on promotion of resistance in the oral flora of children.

BACKGROUND: The long elimination half-life of azithromycin allows subinhibitory serum and epithelial lining fluid (ELF) concentrations over a period of several weeks post treatment, which may have an impact on the emergence of macrolide resistance. In this prospective, open-label, randomized study, four macrolides and the azalide azithromycin were studied for their likelihood to promote resistance in the oral flora of children with respiratory tract infections. PATIENTS AND METHODS: Children were randomly assigned to receive azithromycin, clarithromycin, erythromycin, roxithromycin and josamycin. Throat swabs were obtained prior to treatment and weekly for 6 weeks. Minimum inhibitory concentrations (MICs) for resistant strains were assessed by E-test and National Committee for Clinical laboratory Standards (NCClS) broth microdilution. RESULTS: One week post treatment, up to 90% of children harbored macrolide-resistant strains in their oral flora. Except for azithromycin, the percentage of patients colonized by resistant organisms decreased to a rate of 17% for clarithromycin (10/60), erythromycin (2/12) and josamycin (2/12) and 33% for roxithromycin (4/12) after 6 weeks. In the azithromycin group, 85% (51/60) of patients were colonized by macrolide-resistant organisms after 6 weeks, 11.6% (7/60) of children suffered from reinfection. CONCLUSION: Azithromycin therapy appears to put selective pressure on the infective and native flora of children, promoting the carriage of macrolide-resistant strains.

Adolescent↗
PubMed2001

Rosacea-like demodicidosis associated with acquired immunodeficiency syndrome.

We present a 35-year-old patient with acquired immunodeficiency syndrome who had demodicidosis on his face, characterized by multiple papules and papulopustules, associated pruritus, numerous mites on skin-surface biopsy and in biopsy specimens, and rapid response to topical treatment with permethrin. It seems likely that Demodex infestation does not manifest unless local or systemic immune function is altered, leading to the proliferation of the organism and subsequent disease.

AIDS-Related Opportunistic Infections↗
PubMed2001

Topical anti-inflammatory activity of a new germacrane derivative from Achillea pannonica.

The topical anti-inflammatory activity of a germacrane derivative [1,4-dihydroxy-germacra-5E-10(14)-diene; DHGD] isolated from Achillea pannonica Scheele (Asteraceae) was investigated employing the Croton oil-induced dermatitis in the mouse ear. Its effects on the oedematous response and on leukocytes infiltration are described. The germacrane derivative significantly inhibited ear oedema in a dose-dependent manner, with an ID(50) of 0.40 micromol/cm(2). DHGD (0.75 micromol/cm(2)) provoked a global inhibition of the oedematous response (61 %) higher than that induced by an equimolar dose of indomethacin (43 %) within 24 hours; the reduction induced by hydrocortisone (0.10 micromol/cm(2)) was 68 %. The effect of DHGD (61 % inhibition) was higher than that of the equimolar dose of indomethacin (51 % inhibition) also on granulocytes recruitment at the site of inflammation. Hydrocortisone (0.10 micromol/cm(2)) reduced the cellular infiltrate by 44 %.

Administration, Topical↗
PubMed2000

Expression of adhesion receptors on rat limb bud cells and results of treatment with a thalidomide derivative.

The expression of several adhesion surface receptors was studied on cells of early limb bud development of 58 Wistar rats treated orally with two daily doses of the thalidomide derivative EM12 (2 x 50 mg/kg body weight) from day 7 to 10 of pregnancy. EM12 is a more potent teratogen than thalidomide. Limb bud cells of 56 untreated animals served as controls. The studies revealed that the integrins CD11a, CD11b, CD18, CD49d, and CD61, as well as the additional adhesion receptors CD54, CD62L, and the transferrin receptor CD71 were expressed on day 11 of gestation to various degrees on these embryonic cells. In contrast to results of previous studies with a non-human primate (Callithrix jacchus) there was no down-regulation of any of these receptors on the surface of limb bud cells of the rat embryos after treatment with EM12. This result is in accordance with the lack of teratogenicity in this rodent species.

Animals↗
PubMed1999

Qualitative and quantitative determination of sesquiterpenoids in Achillea species by reversed-phase high-performance liquid chromatography, mass-spectrometry and thin-layer chromatography.

A reversed-phase high-performance liquid chromatographic method was developed as a universal analysis system in order to determine and quantify antiphlogistic sesquiterpenoids in different Achillea species. Identification was performed by HPLC and diode array detection as well as by monitoring the HPLC fractions by TLC and MS. Using santonin as internal standard, HPLC separations were achieved with a methanol-water gradient system using RP 8 LiChrospher 100 (5 microm) as stationary phase. For validation, sample analyses were performed, using the two tetraploid species A. collina and A. pratensis. The method allows the identification and quantification of the main compounds achillicin, 8alpha-tigloxy-artabsin, 8alpha-angeloxy-artabsin, arglanin and santamarin with variation coefficients between 3.4 and 4.7% (total content) using santonin as internal standard. For the different compounds recovery was found between 81 and 107% performing multiple analyses of A. collina and A. pratensis.

Calibration↗
PubMed1998

[Balanitis/balanoposthitis chronica circumscripta benigna plasmacellularis--entity or fiction?].

During the years 1985 up to 1995 53 patients between 18 and 80 years of age (mean age 54.7 years) with histologically and clinically proven Zoon's balanitis were treated by circumcision. The majority of patients had symptoms for more than 12 months. In five cases they had lasted for 8, 10, 16, 17 and 47 (!) years. 30 patients were investigated by means of physical examination and questionnaire in this retrospective study. Lesions involved glans in all patients, while in 17 of 30 patients both glans and prepuce were involved. None of the patients showed lesions of the prepuce only. In most cases Zoon's balanitis was successfully treated by circumcision in a period of two to four weeks. In four cases, psoriatic lesions, and in one case lichen ruber was diagnosed. In the remaining patient, whose circumcision was inadequate, a small area of balanitis persisted in the sulcus coronarius still covered by the foreskin. The curative effect of adequate circumcision in 100% of patients suggests that Zoon's balanitis is a relatively non-specific reactive balanitis caused by a disturbed "preputial-ecology". It is remarkable that other distinct inflammatory diseases of glans and prepuce can show features which are identical to those Zoon's balanitis.

Adolescent↗
PubMed1998

[Bleomycin-induced PSS-like pseudoscleroderma. Case report and review of the literature].

Although the association between administration of the antitumor agent bleomycin and the development of cutaneous fibrosis is established, there are only a small number of cases of bleomycin-induced scleroderma described in the literature. We report the development of generalised scleroderma with wide spread hyperpigmentation in a 52-year-old male patient, who received a total dose of 360 mg bleomycin in combination with cisplatin and etoposid for therapy of a malignant testicular seminoma. The clinical cutaneous alterations as well as the histological findings were indistinguishable from those encountered in progressive systemic sclerosis (PSS). In contrast to PSS however, Raynaud's phenomenon, cutaneous calcinosis, teleangiectasia, arthritis and involvement of additional organs were all absent. PSS-typical auto-antibodies were negative. Even 18 months after discontinuation of the drug and treatment with UVA1 phototherapy (3-4 times per week with 20 J/cm2) as well as physiotherapy, the skin changes had still not resolved. Based on our case and a detailed review of the literature, we discuss characteristics of bleomycin-induced scleroderma including pathogenesis, treatment modalities and course.

Antibiotics, Antineoplastic↗
PubMed1995

Development of a suspension organ culture of the fetal rat palate.

On the basis of an already established suspension organ culture system of mouse palate anlagen, we developed a corresponding culture system for rat palate anlagen. In order to optimize the culture results we systematically studied the influence of main "culture conditions" such as dissection technique, rotation speed, gassing schedule, and developmental stage at the onset of culture for mice and rat palate anlagen. This system allows culturing rat palate anlagen from day 15 of gestation to day 18 + 8 h (80 h) under serum- and antibiotic-free conditions using a chemically defined medium, resulting in 90% fused palates. The explants, containing the maxillary vault and the palatal shelves, were cultured in siliconized culture flasks at a rotation speed of 12 rpm and a temperature of 37 degrees C (Table 1).

Animals↗
PubMed1992

Effect of six virustatic nucleoside analogues on the development of fetal rat thymus in organ culture.

The effects of the virustatic agents zidovudine (azidothymidine, AZT) 2'3'-dideoxycytidine (ddC), 2'3'-dideoxyinosine (ddI), acyclovir (ACV), ganciclovir (GCV), and vidarabine phosphate (VP) on the in vitro development of thymic lobes of 17-day-old rat fetuses were tested in an organ culture system. The virustatics were added to the medium for a culture period of 7 days. All nucleoside analogues inhibited the proliferation and differentiation of lymphatic cells. However, differences were observable with respect to the potency of the six drugs to interfere with thymic development. Compared to untreated controls, reduction in the number of thymocytes was significant at concentrations of 30 microM AZT and ddI. In the case of ACV, GCV, VP, and ddC concentrations as low as 10 microM were sufficient to cause a significant reduction, ddC being the most potent derivate. Increasing concentrations of the nucleoside analogues led to a dose-dependent further inhibition of cell proliferation. At a concentration of 30 microM flow cytometry revealed a decrease in the relative number of double positive CD4+ CD8+ and single positive CD4+ CD8- cells but an increase in the relative number of CD4-CD8+ cells. At the same concentration the expression of the CD5 antigen was reduced by the antimetabolites, indicating that maturation of the thymocytes was inhibited. Distribution of the forward light scatter, a cell size-related parameter, showed that the formation of small thymocytes was reduced by the nucleoside analogues. Light and electron microscopic investigations indicated cytotoxic effects of the drugs on the thymocytes, whereas the epithelium was only slightly affected.

Animals↗
PubMed1990

Pharmacokinetics and bioavailability of beta-sitosterol in the beagle dog.

Tritium-labelled beta-sitosterol (BSS) 10 mg was administered to 6 beagle dogs in a 3-way crossover study: 1. i.v. solution, 2. p.o. powdered BSS, and 3. BSS embedded in a polyethyleneglycol (PEG) melt. The concentration-time profiles for both routes of administration were best described by a two-compartment open model with a fast distribution phase, having a t1/2 alpha of about 3 h, and a terminal disposition phase having a t1/2 beta of about 129 h. The volume of distribution of the central compartment corresponds to the total body fluid (Vc = 0.56 l/kg), and the apparent volume of distribution is about equal to the total body weight (V d/beta = 0.92 l/kg). The mean residence time is about 185 h. The absolute bioavailability upon p.o. administration is about 9%. The PEG embedment of BSS does not increase the extent of absorption; however, the rate of absorption is significantly increased.

Administration, Oral↗
PubMedDate not supplied

[Blood propionic acid with hyperammonemic coma].

We report on a mature male newborn who presented clinically on the 2nd day of live with poor feeding and acidotic breathing. Laboratory findings like severe metabolic acidosis, hyperammonemia, hyperglycinemia, ketonuria and elevated urinary excretion of lactate and propionate suggested the presence of organoacidopathia. Propionic acidemia, however could be diagnosed definitively only when the characteristic urinary and blood metabolites were found during the state of a hyperammonemic coma provoked by a fully oral protein regimen. The diagnosis was affirmed by reduced propionate fixation and by reduced propionyl-CoA-carboxylase shown in the patient's skin fibroblasts.

Acidosis↗