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Biomedical subjects

M Tiefenthaler

Publications and source records attributed to M Tiefenthaler.

At least 19 recordsLinked to original sources
PubMed2003

Apoptosis of CD34+ cells after incubation with sera of leukopenic patients with systemic lupus erythematosus.

Leukopenia and anaemia are observed in about a fifth of all patients with systemic lupus erythematosus (SLE) and may be due either to the destruction of blood cells or their decreased production. The former may be humoral or cell-mediated or result from apoptosis of peripheral blood cells. Several observations suggest the occurrence of the latter reduced in vitro proliferation of pluripotent bone marrow progenitors from the bone marrow aspirates of SLE patients,reduced counts of CD34+ cells in bone marrow aspirates in SLE patients, apoptosis of lymphopoietic progenitors and apoptosis of bone marrow cells. The aim of our study was to investigate whether humoral factors may induce suppression of haematopoiesis by increased apoptosis of CD34+ cells. For this purpose, we incubated allogeneic CD34+-enriched cells with sera of 18 leukopenic SLE patients. Apoptosis was induced by four of 18 sera. This effect was independent of complement-inhibition and FAS-blockade. Although reduced proliferation of autologous pluripotent bone marrow progenitors has been attributed to an IgG serum inhibitor, removal of IgG from these four proapoptotic sera had no effect on apoptosis of allogeneic CD34+ cells. The proapoptotic effect was associated with high titres of anti-dsDNA antibodies and low haemoglobin concentrations, but not with high titres of antinuclear antibodies, TNF-alpha and IFN-alpha of the sera tested.

Antigens, CD34↗
PubMed2003

[Reduced costs of hospitalization at the start of hemodialysis by previous creation of an AV-fistula. Investigation of the Austrian system of financing data of incident patients from 1999 to October 2000 at the Landeskrankenhaus Innsbruck University clinic].

Costs of renal replacement therapy are enormous, of which hospitalisation is a major factor. International and national guidelines recommend early creation of fistulas before the start of the haemodialysis. The aim of this study is to calculate the costs of the initial hospitalisation of all incident patients (n = 79) based on the data of the "leistungsorientierte Krankenhaus-finanzierung", which means the Austrian system of financing hospital care according to interventions and diagnosis-groups in the years 1999 and 2000 at the Landeskrankenhaus Innsbruck. The average costs of the hospitalisation at the start of haemodialysis treatment are not significantly different when comparing haemodialysis patients (n = 69) to peritoneal dialysis patients (n = 10). Patients on haemodialysis were divided into two groups, depending on the presence of a usable AV-fistula at the start of the haemodialysis treatment. Costs for both groups differ significantly; for patients of the shunt-group (n = 28) at 4.437 +/- 567 [symbol: see text] they are less than half as high as costs for unprepared patients (no-shunt-group, n = 41) at 9.704 +/- 783 [symbol: see text]. Diagnosis dependent costs (Tageskostenanteile) are 75% higher for patients without shunt compared to patients of the shunt group (4040 vs. 2300 [symbol: see text]). Patients without shunt are hospitalised significantly longer than patients with shunt (18.85 vs. 12.03 days) and qualify less often for kidney transplantation than patients with shunt (28.9% vs. 61.3%). In summary, the data of the "leistungsorientierte Krankenhausfinanzierung" in combination with clinical data (availability of a useable dialysis access, enrolment in kidney transplantation) gives us reliable information on days of hospitalisation, number of dialysis treatments and costs of hospitalisation upon initiation of renal replacement therapy. Based on these data, the rigorous creation of sufficient AV-fistula prior to the start of haemodialysis in all incident patients can save up to 66.400 [symbol: see text]/year of inpatient costs at the Landeskrankenhaus Innsbruck.

Arteriovenous Shunt, Surgical↗
PubMed2002

[Ultrasonic diagnosis of calciphylactic lesions].

Calciphylaxis is a serious disease most commonly occurring in patients with end-stage renal disease characterized by systemic medial calcification of the arteries and tissue necrosis due to ischaemia. Secondary infections contribute to the high mortality of this disease. Diagnosis is suggested by characteristic skin lesions, calcifying septal panniculitis on deep skin biopsy and detection of calcifications in conventional radiology. We are able to demonstrate the early diagnosis with high resolution high frequency ultrasound prior to the occurrence of typical skin lesions facilitating early treatment.

Body Mass Index↗
PubMed2001

[Prevalence of sleep disorders in school children between 11 and 15 years of age].

UNLABELLED: Little is known about sleep disorders in children and adolescents that might affect physical and emotional well-being. Depending on age and size of the cohort group, and differences in questionnaires, prevalence varies between 1-43% in international studies. We examined the prevalence of symptoms characteristic of sleep disorders in school aged children with a questionnaire which allows indication of symptoms by the children themselves. METHODS: An anonymous questionnaire, based on the German Dresden questionnaire, with 22 questions concerning the main symptoms of obstructive sleep apnea syndrome (OSAS), general symptoms of para- and insomnia as well as sociodemographic data, was developed. 332 pupils (age: 11-15 y, mean: 12.75 y; median: 12 y; 56% female, 44% male) in 2 high schools in Vienna were investigated. RESULTS: 28% (n = 93/332) of the examined group reported snoring (the main symptom of OSAS) and/or insomnia (night waking almost every night) or parasomnia (nightmares, night terrors or sleepwalking almost every night). 15% (n = 14/93) of this subgroup reported snoring and para- or insomnia coincidentally. Girls were affected more frequently than boys by nocturnal awakening (79% vs. 56%, p < 0.001) and nightmares (64% vs. 52%, p < 0.01). The snoring group (21% (71/332) of all examined children) was affected more frequently by mouth dryness (16% vs. 4%, p < 0.001), pallor (7% vs. 3%, p < 0.01), night sweats (6% vs. 1%, p < 0.05) and from the following sleep disorders: nightmares (10% vs. 2%, p < 0.01), night terrors (4% vs. 1.5%, p < 0.001), sleepwalking (1.4% vs. 1%, p < 0.05) and nocturnal awakening (16% vs. 5%, p < 0.01). DISCUSSION: Almost every fifth child reports about at least one main symptom characteristic of OSAS. The statistically significant relation between symptoms of OSAS and non-organic sleep disorders shows the necessity of interdisciplinary focusing on sleep disorders. Further epidemiological studies need to be carried out in order to clarify the role of sleep anamnesis in the diagnosis and management of sleep disorders during childhood.

Adolescent↗
PubMed2001

Clinical and neuropsychological outcome in 33 patients with biotinidase deficiency ascertained by nationwide newborn screening and family studies in Austria.

UNLABELLED: Newborn screening for biotinidase deficiency (BD) provides prevention of neurological sequelae in patients with low residual enzyme activity by early treatment with oral biotin substitution. Screening 1.1 million newborns in Austria and consecutive family studies led to the identification of 21 patients with profound BD (residual activity <10%) (incidence: 1:59,800) and to 12 patients with partial BD (residual activity 10%-30%) (incidence 1:89,700). Application of an HPLC assay using the natural substrate biocytin allowed exact quantification of extremely low residual biotinidase activities and thus subdivision of patients with profound BD into a group with a residual activity 0%-1% of normal activity (n = 5) and >1%-<10% (n = 16) respectively. Evaluation of clinical and neuropsychological outcome showed that only patients with a biotinidase activity < 1% (n = 3/5) exhibited characteristic clinical symptoms within the first weeks of life, while five patients with a residual activity of 1.2%-4.6% did not develop clinical symptoms even when not treated until 3.5 21 years. In all patients with residual activity <10% and biotin substitution within the first weeks of life, neuropsychological outcome was normal, while abnormal in three out of five patients tested for IQ and treated after the age of 3.5 years. In five out of nine patients with poor compliance or delayed or no treatment, visual and brainstem auditory evoked potentials were measured and were within age-related normal values. All patients with partial BD available for follow-up remained clinically and neuropsychologically asymptomatic without treatment at ages 2.5 10 years. CONCLUSION: The incidence of biotinidase deficiency in Austria is comparable to other European countries. Subdivision of the group of patients with profound biotinidase deficiency suggests that only patients with residual activities < 1% are prone to develop clinical symptoms early in life, while patients with residual activities >1% may remain asymptomatic even without treatment, as do patients with partial deficiency. Moderate mental retardation might represent a possible manifestation of cerebral dysfunction in patients with profound biotinidase deficiency.

Adolescent↗
PubMed2001

Increased lactate production follows loss of mitochondrial membrane potential during apoptosis of human leukaemia cells.

Acute tumour-lysis syndrome (ATLS) is a frequently fatal complication after cytoreductive leukaemia therapy. Lactic acidosis is associated with ATLS and its extent is correlated with the severity of ATLS. In the course of cytoreductive therapy, apoptosis is induced in tumour cells, which results in loss of mitochondrial function. We hypothesize that loss of mitochondrial function leads to compensatory glycolysis, which is the main cause of lactate accumulation and acidosis. We tested this hypothesis using the model of glucocorticoid-induced apoptosis in the human acute lymphoblastic leukaemia cell line CCRF-CEM. After induction of glucocorticoid-induced apoptosis, a biphasic course of lactate production was observed. Prior to the onset of apoptosis, i.e. prior to the loss of membrane potential, lactate production was reduced. However, subsequent to loss of mitochondrial membrane potential a massive increase in lactate production was observed (15.5 +/- 0.5 versus 10.17 +/- 0.09 mmol/10(6) cells, P = 0.001). We also demonstrated that inhibition of respiratory chain activity by antimycin A resulted in excess lactate production. In the model cell line used, conditional bcl-2 expression delayed glucocorticoid-induced apoptosis by protecting against loss of mitochondrial membrane potential; bcl-2 expression delayed the increase in lactate production and had no effect on the pre-apoptotic drop in lactate production. Apoptosis-induced lactate production was also observed in other cell lines (HL60, THP1 and OPM2) with various cytotoxic agents [doxorubicin, gemcitabine and vumon (VM26)]. Thus, the data suggest that lactate acidosis can be caused by apoptotic loss of mitochondrial function and massive apoptosis of a tumour mass via lactic acidosis may be the essential pathological event in ATLS.

Antineoplastic Agents, Hormonal↗
PubMed2001

[Value of sonography in kidney transplantation].

Colour coded duplex sonography (CCDS) is the method of choice in diagnostic monitoring of kidney transplants. Lack of radiation exposure, easy accessibility and high resolution have contributed to the fact that CCDS is used to monitor kidneys after transplantation. However, the value of CCDS in diagnosis of rejection is still a matter of debate. CCDS is used to evaluate perfusion of transplanted kidneys, detect renal artery stenosis or real vein thrombosis and arteriovenous fistulas. The value of recent technical advances, such as 3D Sonography, contrast harmonic imaging and tissue harmonic imaging, is currently being tested. This article focuses on indications and limitations of CCDS in the diagnosis of functional impairment of transplanted kidneys.

Graft Rejection↗
PubMed2000

Effects of transdermal nicotine on cognitive performance in Down's syndrome.

Down's syndrome involves age-dependent neuropathological and neurochemical changes similar to Alzheimer's disease, with cholinergic deficits being the most consistent. There is currently no proven treatment for Down's syndrome. We investigated the effect of nicotine-agonistic stimulation with 5 mg transdermal patches, compared with placebo, on cognitive performance in five adults with the disorder. Improvements possibly related to attention and information processing were seen for Down's syndrome patients compared with healthy controls. Our preliminary findings are encouraging, although not generalizable because of small numbers.

Administration, Cutaneous↗
PubMed2000

SIDS related anxiety--a risk factor analysis.

BACKGROUND: The growing public interest in the Sudden Infant Death Syndrome (SIDS) has led to a new psychological problem--SIDS related anxiety (SRA). General public awareness, unfavourable experience in the past, present problems with the infant or insufficient support from the family may lead or contribute to SRA. OBJECTIVE: The study was conducted to explore which of these factors contribute most to the development of SRA. PATIENTS AND METHODS: Families visiting our outpatient clinic during 18 months were interviewed by means of a structured questionnaire. We assessed demographic data, obstetric history, experience of child loss, pregnancy and delivery complications, infant morbidity, family-child interaction, family support and the relation of each of these single factors to SRA. RESULTS: Of 169 families, 58% (98/169) admitted to suffer from SRA and 21% (32/156) from severe SRA. We found a strong and significant relationship between previous experience of child loss and SRA (OR: 2.95, 95% CI: 1.43-6.09, P < 0.005) and between pregnancy complications and SRA (OR: 2.19, 95% CI: 1.18-4.08, P < 0.05). There were no significant relationships between SRA and either delivery complications, child morbidity, impaired family-child interaction or insufficient support from the family. CONCLUSIONS: SRA occurs in an unexpectedly large proportion of families visiting a SIDS counseling clinic. SRA must be taken seriously, and psychological or psychotherapeutic help should be offered. Prevention of SRA should include psychological care for families who experience loss of children or high-risk pregnancies.

Adult↗
PubMed2000

Prolonged generalized epileptic seizures triggered by breath-holding spells.

We report a 3-year-old female with anoxic-epileptic seizures. Beginning at 11 months of age, she had repeated breath-holding spells with transition into generalized tonic-clonic seizures or status epilepticus. Interictal electroencephalography exhibited no abnormalities. A multidisciplinary diagnostic approach revealed a severely disturbed mother-daughter relationship that was the trigger of the breath-holding spells. Psychotherapy for the mother and daughter led to cessation of the breath-holding spells and, consequently, of the anoxic-epileptic seizures. Her further development was largely normal. We discuss the etiology and treatment of anoxic-epileptic seizures. This case is the first reported case of anoxic epileptic seizures that responded to psychologic rather than antiepileptic treatment. We advocate an initial psychologic assessment to help determine the appropriate treatment in children with recurrent anoxic-epileptic seizures.

Apnea↗
PubMed2000

Inhibition of LncaP prostate cancer cells by means of androgen receptor antisense oligonucleotides.

Currently available methods for treatment of human prostatic carcinoma aim to inactivate the androgen receptor (AR) by androgen deprivation or blockade with anti-androgens. Failure of endocrine therapy and tumor progression is characterized by androgen-independent growth despite high levels of AR expression in metastatic disease. We inhibited AR expression in LNCaP prostate tumor cells by using antisense AR oligodeoxynucleotides (ODNs) and explored whether antisense AR treatment would be conceivable as a therapy for advanced prostate cancer. Among the various AR antisense ODNs tested, a 15-base ODN targeting the CAG repeats encoding the poly-glutamine region of the AR (as750/15) was found to be most effective. Treatment of LNCaP cells with as750/15 reduced AR expression to approximately 2% within 24 hours compared with mock-treated controls. AR down-regulation resulted in significant cell growth inhibition, strongly reduced secretion of the androgen-regulated prostate-specific antigen, reduction of epidermal growth factor receptor expression, and an increase in apoptotic cells. Mis-sense and mismatched control ODNs had no or only slight effects. Antisense inhibition was also very efficient in LNCaP-abl cells, a subline established after long-term androgen ablation of LNCaP cells, resulting in inhibition of AR expression and cell proliferation that was similar to that seen for parental LNCaP cells. This study shows that inhibition of AR expression by antisense AR ODNs may be a promising new approach for treatment of advanced human prostate cancer.

Apoptosis↗
PubMed2000

Familial idiopathic West syndrome.

Two families, each with occurrence of West syndrome in two siblings, are presented. Monozygotic twins in family 1 developed infantile spasms at the age of 4 months. Two female siblings in family 2 started to have seizures at the age of 6 months, but 2 years apart. The family history; development prior to West syndrome; clinical, electroencephalographic, and neuroradiologic findings; diagnostic work-up; and treatment are described. The outcome in family 1 (follow-up after 2 years) showed no conspicuous findings on physical and neurologic examination, and psychomotor development appropriate to cognitive, motor, and language developmental age in both twins. In family 2 (follow-up after 3 and 5 years), the older sister only was one standard deviation below mean in intellectual developmental age. Simultaneous occurrence of infantile spasms in both siblings from these two families but with variable clinical expression suggests there is a genetic susceptibility and variable phenotypic expression. Long-term follow-up will demonstrate whether these cases may be classified as "familial idiopathic West syndrome."

Adult↗
PubMed2000

Age dependent apoptosis and loss of rhabdosphincter cells.

PURPOSE: To our knowledge the exact age dependent morphological and functional changes of the sphincter mechanism have not been investigated. Therefore, cell densities of the urethra and the urethral rhabdosphincter across various age groups, and the appearance of apoptosis were examined to explore the changes in these structures during the aging process. MATERIALS AND METHODS: Specimens were obtained from 16 male and 7 female cadavers 5 weeks to 92 years old. Histological sections were taken from 3 different levels of the rhabdosphincter and urethra. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling method was used to detect apoptosis in the urethra and rhabdosphincter. In all specimens relative volume densities of the striated muscle fibers, apoptotic indexes and diameters of the rhabdosphincter and urethra were determined. RESULTS: An age dependent increase of apoptosis of the striated muscle fibers of the rhabdosphincter led to a dramatic decrease in the number of striated muscle cells. In the 5-week-old neonate 87.6% and in the 91-year-old woman 34.2% of the rhabdosphincter consisted of striated muscle cells. Overall, a direct linear correlation between the age of the specimens and decrease in volume densities of the striated muscle cells was evident. CONCLUSIONS: The dramatic decrease in the number of striated muscle cells in the rhabdosphincter of the elderly due to apoptosis represents the morphological basis for the high incidence of stress incontinence in this population.

Adolescent↗
PubMed1999

Gemcitabine--a novel immunosuppressive agent--prevents rejection in a rat cardiac transplantation model.

BACKGROUND: 2',2' -difluorodeoxycytidine (dFdC, gemcitabine) is a pyrimidine antimetabolite with antineoplastic activity against a wide range of solid tumors. The immunosuppressive activities of this compound have not been described to date. METHODS: The in vitro effects on activated T lymphocytes were studied with a lymphocyte colony-forming assay in a microagar culture system. Heart transplantations were performed in the fully allogeneic Lewis/ Brown Norway combination. dFdC was administered once daily at various dosages from the time of surgery until day 50. RESULTS: Phytohemagglutinin-induced lymphocyte proliferation was inhibited 50% by dFdC at a concentration of 3.25+/-0.9 nmol/L. Allografts of untreated animals survived for 7.5 (7-8) days and those with 25, 50, and 75 microg/kg body weight dFdC for 7.3 (7-8), 9.3 (8-10), and 16.3 (10-38) days, respectively. Treatment with 100 or 125 microg/kg body weight of dFdC, however, prolonged allograft survival until day 152.8 (129-178). Dose-dependent leukopenia was the main toxicity. CONCLUSIONS: DFdC is a new immunosuppressive agent that can successfully prevent cardiac rejection in a rat transplantation model.

Animals↗
PubMed1999

M1204, a novel 2',5' oligoadenylate synthetase with a ubiquitin-like extension, is induced during maturation of murine dendritic cells.

A novel molecule expressed by spleen dendritic cells (DC) was isolated using a subtractive hybridization approach. The full-length M1204 clone has 3063 bp, with 1415 bp spanning a single open reading frame, coding for a protein of a predicted size of about 50 kDa. This sequence has strong homology to 2', 5' oligoadenylate synthetase and contains a ubiquitin-like domain. In Northern blot analyses the mRNA is strongly expressed in spleen DC, whereas, in bone marrow-derived DC, the amount of mRNA increases during the maturation process. None of the other leukocytes nor several hemopoietic cell lines tested express this mRNA, but clear expression occurs in many organs, the highest levels being in thymus, lung, and bone marrow. In situ hybridization, combined with immunocytochemical staining of tissue sections of lung and spleen, shows colocalization of M1204 with the 2A1 and NLDC DC markers. In Western blot experiments, an antiserum raised against the recombinant M1204 recognizes a single band in bone marrow-derived DC and in the lung. The expressed oligoadenylate synthetase domain is active in synthesizing 2',5' diadenylate, which by itself may inhibit viral protein synthesis and may also function as a substrate for 2',5' oligoadenylate synthetase. Since the oligoadenylate/RNase L system provides early protection against virus infection, we hypothesize that M1204 prevents virus-induced cell death in DC.

2',5'-Oligoadenylate Synthetase↗
PubMed1999

[An adult patient with phenylketonuria before and one year after reinstitution of diet therapy].

BACKGROUND: In phenylketonuria (PKU) a phenylalanine restricted diet during the first years of life can prevent the development of severe cognitive damage. OBJECTIVE: Could neuropsychological or neurological changes occur in a 20-year-old patient with PKU (diagnosed early and treated until the age of 8 years) after 12 years of normal nutrition and if so, can these changes be counteracted by reinstitution of a low phenylalanine diet? METHODS: Psychological (intelligence, attention), neurophysiological (evoked potentials) and neuroradiological examination (magnetic resonance tomography [MRT] of the brain) were performed before and after one year of treatment with a diet low in phenylalanine. RESULTS: During the reinstitution of dietary therapy we observed significant improvements in attentiveness (percentage increase of 30), whereas intelligence subtests remained stable, a reduction in hyperreflexia, shortening of the latencies of the evoked potentials and a decrease in periventricular pathological signal alterations as evaluated by MRT. CONCLUSIONS: The reintroduction of a diet low in phenylalanine improved psychological and neurological symptoms in this PKU patient. We recommend a constant low-phenylalanine diet throughout life in patients with PKU.

Adult↗