Biomedical subjects

J Schwarz

Publications and source records attributed to J Schwarz.

At least 55 records · Page 3Linked to original sources

PubMed2002

Laparoscopic transperitoneal procedure for routine repair of groin hernia.

BACKGROUND: Laparoscopic transperitoneal hernioplasty (TAPP) repair of inguinal hernias is thought to be a difficult surgical technique with high complication rates. The present study evaluated TAPP based on prospective documentation. METHODS: The primary aim of the study was analysis of the individual learning curve, comparing consultants with trainees. Secondary endpoints included postoperative morbidity, time of disability and rate of recurrence. RESULTS: A total of 8050 TAPP repairs have been performed since 1993. By 2001, 99.9 per cent of all hernia repairs were done by TAPP. The median operation time dropped from 50 min in the first 600 cases to 42 min thereafter. The morbidity rate decreased from 9.3 to 2.6 per cent, and the rate of recurrence from 4.8 to 0.4 per cent. Within the same interval the proportion of training procedures increased from 1.7 to 44.9 per cent in 2001. Morbidity and recurrence rates were similar for trainees and consultants. CONCLUSION: TAPP is an effective and safe technique. It can be performed in a standard way for all inguinal and femoral hernias. The present results indicate that TAPP is possible in a routine setting, as well as in the training situation for young surgeons.

Adolescent↗

PubMed2002

[Emergency ERCP].

Although the effectivity of an urgent ERCP was confirmed, some aspects relating to this method are still discussed. Timing of this procedure has not been established yet. Whereas there is no doubt about indication with decompression of the common bile duct in acute cholangitis, views on the effectiveness of examination incl. papillotomy in case of acute pancreatitis are not uniform. The authors demonstrate a group of 538 patients who had urgent ERCP within the last three years with a successful cannulation rate of 93%. The experience of large centres is confirmed as the great efficiency and effectivity of this procedure when the standard conditions and processes are respected.

Acute Disease↗

PubMed2002

[Gastric carcinoma--the sentinel node concept: initial experience].

Gastric cancer is a serious malignant disease. The only hope for long time survival is radical surgery. It consists of gastrectomy and also resection of adjacent lymphatic tissues. The extent of lymphadenectomy is one of the currently discussed questions. D2 lymphadenectomy is now becoming standard also in our country. This extensive procedure can be quite difficult and needs an experienced surgeon. It is also connected with prolonged operation time and higher costs. According to some authors, this procedure is also associated with a higher morbidity. The question, whether D2 lymphadenectomy should be performed, could be answered by the sentinel node concept, which is the topic of our work.

Adenocarcinoma↗

PubMed2002

[Importance of prognostic factors in patients with chronic B-lymphocytic leukemia at the time of diagnosis].

BACKGROUND: B-chronic lymphocytic leukemia (B-CLL) is the most common adult leukemia in the Western countries. Any routinely used staging system does not distinguish exactly the probable course of the disease at the time of diagnosis. Therefore the new prognostic factors, which help to assess the optimal therapeutic plan of patients, are searched intensively. METHODS AND RESULTS: We evaluated 154 patients with the B-CLL at the time of diagnosis--133 of them were retrospectively divided into two groups--one with stable form and the other with progressive form of the disease. We compared these two groups of patients with some of the prognostic factors (absolute lymphocyte count, the level of C-reactive protein, lactatdehydrogenase, beta-2-microglobulin, tumour necrosis factor, the immunoglobulin levels, the expression of CD38, FMC7, surface immunoglobulins, the type of bone marrow infiltration, and the cytogenetic abnormalities (trisomy 12, del(13)(q14), del(17)(p13) a del(11)(q23)). We found higher absolute lymphocyte count, level of beta-2-mikroglobulin, tumour necrosis factor, expression of CD38, light chains lambda, lower expression of FMC7 and less frequent nodular type of bone marrow infiltration by the patients with progressive disease. The correlation of the cytogenetic abnormalities and the course of the disease or stage according to the RAI et al. [27] staging system were not significant may be due to the small number of evaluated patients and short period of follow up. CONCLUSION: The routine evaluation of some risk factors in patients with B-chronic lymphocytic leukemia at the time of diagnosis helps to distinguish those with the probable more aggressive course of the disease and have the implication for the design of risk-adapted treatment strategies. The prognostic impact of the cytogenetic abnormalities and other risk factors has to be evaluated on larger group of patients during longer follow up period and repeated evaluations.

Biomarkers, Tumor↗

PubMed2001

Master-slave synchronization in chaotic discrete-time oscillators.

In this paper, we study a simple discrete-time neural oscillator model that, in certain parameter regimes, exhibits periodic or chaotic dynamics. The present model with intrinsically chaotic dynamics is capable of spatiotemporal information processing: in response to constant external stimulation, the oscillator can switch into different chaotic states restricted to distinct parts of the phase space. Of particular interest is the processing of time-dependent input in a master-slave configuration of two coupled oscillators. Here, the response of an oscillator is studied by driving it with the signal of the other. Following the input, the response system adapts to the state of the drive. For a chaotic drive, we can observe generalized synchronization. The onset of adaptation to the drive state by the response is accompanied by on-off intermittency resulting in irregular bursting behavior.

Journal Article↗

PubMed2001

Idiopathic myelofibrosis complicated by portal hypertension treated with a transjugular intrahepatic portosystemic shunt (TIPS).

Idiopathic myelofibrosis may be accompanied by portal hypertension. The authors report a 56-year-old man with idiopathic myelofibrosis and splenomegaly complicated by hepatopathy, severe portal hypertension and recurrent variceal bleeding. A transjugular intrahepatic porto-systemic shunt (TIPS) was inserted. Variceal bleeding never recurred. A short episode of encephalopathy, which is a known complication of porto-systemic shunting, ceased promptly after conservative treatment. The patient eventually died six months later due to metabolic deterioration and hepatic failure related to his underlying hematological disease. TIPS is a promising treatment modality for alleviating symptomatic portal hypertension in hematological disorders.

Biopsy↗

PubMed2001

Point mutant mice with hypersensitive alpha 4 nicotinic receptors show dopaminergic deficits and increased anxiety.

Knock-in mice were generated that harbored a leucine-to-serine mutation in the alpha4 nicotinic receptor near the gate in the channel pore. Mice with intact expression of this hypersensitive receptor display dominant neonatal lethality. These mice have a severe deficit of dopaminergic neurons in the substantia nigra, possibly because the hypersensitive receptors are continuously activated by normal extracellular choline concentrations. A strain that retains the neo selection cassette in an intron has reduced expression of the hypersensitive receptor and is viable and fertile. The viable mice display increased anxiety, poor motor learning, excessive ambulation that is eliminated by very low levels of nicotine, and a reduction of nigrostriatal dopaminergic function upon aging. These knock-in mice provide useful insights into the pathophysiology of sustained nicotinic receptor activation and may provide a model for Parkinson's disease.

Animals↗

PubMed2001

Long-term proliferation and dopaminergic differentiation of human mesencephalic neural precursor cells.

We report on generation of dopamine neurons from long-term cultures of human fetal mesencephalic precursor cells. These CNS precursor cells were successfully expanded in vitro using the mitogens epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF-2). Incubation of these cultures in 3% atmospheric oxygen resulted in higher cellular yields than room air. Following incubation in differentiation media containing interleukin (IL)-1b (IL-1b), IL-11, leukemia inhibitory factor (LIF), and glial cell line-derived neurotrophic factor (GDNF), up to 1% of the precursor cells converted into cells immunoreactive for tyrosine hydroxylase (TH), a marker for dopamine neurons. The TH immunoreactive cells exhibited morphological and functional properties characteristic of dopamine neurons in culture. These precursor cells might serve as a useful source of human dopamine neurons for studying the development and degeneration of human dopamine neurons and may further serve as a continuous, on-demand source of cells for therapeutic transplantation in patients with Parkinson's disease.

Biomarkers↗

PubMed2001

Monoamine oxidase-inhibition and MPTP-induced neurotoxicity in the non-human primate: comparison of rasagiline (TVP 1012) with selegiline.

The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been shown to induce parkinsonism in man and non-human primates. Monoamine-oxidase B (MAO-B) has been reported to be implicated in both MPTP-induced parkinsonism and Parkinson's disease, since selegiline (L-deprenyl), an irreversible MAO-B inhibitor, prevents MPTP-induced neurotoxicity in numerous species including mice, goldfish and drosophyla. However, one disadvantage of this substance relates to its metabolism to (-)-methamphetamine and (-)-amphetamine. Rasagiline (R-(+)-N-propyl-1-aminoindane) is a novel irrevesible MAO-B-inhibitor, which is not metabolized to metamphetamine and/or amphetamine. The present study compared the effects of high doses of selegiline and rasagiline (10 mg/kg body weight s.c.) on MPTP-induced dopaminergic neurotoxicity in a non-human primate (Callithrix jacchus) model of PD. Groups of four monkeys were assigned to the following six experimental groups: Group I: Saline, Group II: Selegiline/Saline, Group III: Rasagiline/Saline, Group IV: MPTP/Saline, Group V: Rasagiline/MPTP, Group VI: Selegiline/MPTP. Daily treatment with MAO-B-inhibitors (either rasagiline or selegiline, 10 mg/kg body weight s.c.) was initiated four days prior to MPTP-exposure (MPTP-HCl, 2 mg/kg body weight subcutaneously, separated by an interval of 24 hours for a total of four days) and was continued until the end of the experiment, i.e. 7 days after the cessation of the MPTP-injections, when animals were sacrificed. MPTP-treatment caused distinct behavioural, histological, and biochemical alterations: 1. significant reduction of motor activity assessed by clinical rating and by computerized locomotor activity measurements; 2. substantial loss (approx. 40%) of dopaminergic (tyrosine-hydroxylase-positive) cells in the substantia nigra, pars compacta; and 3. putaminal dopamine depletion of 98% and its metabolites DOPAC (88%) and HVA (96%). Treatment with either rasagiline or selegiline markedly attenuated the neurotoxic effects of MPTP at the behavioural, histological, and at the biochemical levels. There were no significant differences between rasagiline/MPTP and selegiline/MPTP-treated animals in respect to signs of motor impairment, the number of dopaminergic cells in the substantia nigra, and striatal dopamine levels. As expected, both inhibitors decreased the metabolism of dopamine, leading to reduced levels of HVA and DOPAC (by >95% and 45% respectively). In conclusion, rasagiline and selegiline at the dosages employed equally protect against MPTP-toxicity in the common marmoset, suggesting that selegiline-derived metabolites are not important for the neuroprotective effects of high dose selegiline in the non-human MPTP-primate model in the experimental design employed. However, unexpectedly, high dose treatment with both MAO-inhibitors caused a decrease of the cell sizes of nigral tyrosine hydroxylase positive neurons. It remains to be determined, if this histological observation represents potential adverse effects of high dose treatment with monoamine oxidase inhibitors.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed2001

Epidural analgesia and fetal head malposition at vaginal delivery.

OBJECTIVE: To determine if nulliparas who delivered with on-demand epidural analgesia are more likely to have malpositioning of the fetal vertex at delivery than women delivered during a period of restricted epidural use. METHODS: A retrospective cohort of nulliparous women with spontaneous labor delivered during a 12-month period immediately before the availability of on-demand labor epidural analgesia was compared with a similar group of nulliparas delivered after labor epidural analgesia was available on request. The primary outcome variable was a non-occiput anterior position or malpositioned fetal head at vaginal delivery. RESULTS: The frequency of epidural use increased from 0.9% before epidural analgesia became available on demand to 82.9% afterward. Fetal head malpositioning at vaginal delivery occurred in 26 of 434 (6.0%) women delivered in the before period compared with 29 of 511 (5.7%) in the after period (relative risk 0.95, 95% confidence interval 0.6, 1.6). No statistically significant difference in the incidence of fetal head malpositioning was present after patients were stratified by mode of delivery (Mantel-Haenszel weighted relative risk 0.94, 95% confidence interval 0.6, 1.4). The study sample size provided 85% power to detect a two-fold increase in the incidence of fetal malpositioning from a baseline rate of 6% associated with on-demand epidural use. CONCLUSION: Providing on-request labor epidural analgesia to nulliparas in spontaneous labor did not result in a clinically significant increase in the frequency of fetal head malpositioning at vaginal delivery.

Adolescent↗

PubMed2001

Labor epidural analgesia and intrapartum maternal hyperthermia.

OBJECTIVE: To determine if women receiving continuous epidural analgesia are more likely to develop intrapartum fever and related neonatal effects. METHODS: We conducted a retrospective cohort analysis of nulliparous women with term gestations in spontaneous labor delivered during a 12-month period immediately before the availability of on-demand labor epidural analgesia (Before group) and a similar group of nulliparas delivered after labor epidural analgesia was available on request (After group). RESULTS: The frequency of epidural increased from 1% before the availability of on-request epidural analgesia to 83% after epidural analgesia was available on request. A maximal temperature of at least 100.4F was detected in three of 498 (0.6%) women in the Before group, and in 63 of 572 women (11.0%) in the After group (relative risk [RR] = 18.3, 95% confidence interval [CI] 5.8, 57.8, P <.01). Logistic regression analysis demonstrated that on-request labor epidural analgesia was associated with an intrapartum temperature of at least 99.5F (RR = 3.0, 95% CI 2.3, 3.6, P <.001) and intrapartum temperature of at least 100.4F (RR = 20.2, 95% CI 7.0, 86.0, P <.001). There were statistically significant increases in the proportion of newborns who had complete blood counts (24% versus 13.5%, RR = 1.5, 95% CI 1.3, 1.8, P <.01) and blood cultures (30.7% versus 8.6%, RR = 1.7, 95% CI 1.2, 2.4, P <.05) in the After period compared with the Before group; however, there was no statistically significant difference in the proportion of infants who received antibiotic therapy for presumed sepsis between the After and Before periods (5.8% versus 4.6%, RR = 1.15, 95% CI 0.8, 1.6, P =.38). No infants in either group had culture-proven sepsis. CONCLUSION: The use of labor epidural analgesia is associated with a clinically significant increase in the incidence of intrapartum fever.

Adult↗

PubMed2001

Aleukemic granulocytic sarcoma with AML1/ETO fusion gene expression and clonal T cell populations.

We report a unique case of aleukemic granulocytic sarcoma of the neck, originally misdiagnosed as non-Hodgkin's lymphoma (NHL), though chloroma was also suspected due to a greenish macroscopic appearance and the presence of myeloid chloroacetate esterase (CAE)+ cells. The proof of clonal T cell receptor gamma chain (TcRgamma) gene rearrangements in the recurring tumor was deemed to confirm the initial diagnosis of T cell NHL. Altogether five distinct types of clonal TcRgamma gene rearrangements were found in the tumor, bone marrow and peripheral blood. Only retrospectively, using RT-PCR, did we detect the acute myeloid leukemia subset-specific fusion gene AML1/ETO in the frozen samples of the relapsed tumor, as well as in the otherwise unaffected bone marrow and peripheral blood (representing 'minimal initial disease' in the latter two samples). Simultaneous staining verified that the neoplastic CAE+ cells and CD45RO+ T cells were different populations.

Adult↗

PubMed2001

Does epidural analgesia prolong labor and increase risk of cesarean delivery? A natural experiment.

OBJECTIVE: More than 50% of pregnant women in the United States are using epidural analgesia for labor pain. However, whether epidural analgesia prolongs labor and increases the risk of cesarean delivery remains controversial. STUDY DESIGN: We examined this question in a community-based, tertiary military medical center where the rate of continuous epidural analgesia in labor increased from 1% to 84% in a 1-year period while other conditions remained unchanged-a natural experiment. We systematically selected 507 and 581 singleton, nulliparous, term pregnancies with spontaneous onset of labor and vertex presentation from the respective times before and after the times that epidural analgesia was available on request during labor. We compared duration of labor, rate of cesarean delivery, instrumental delivery, and oxytocin use between these two groups. RESULTS: Despite a rapid and dramatic increase in epidural analgesia during labor (from 1% to 84% in 1 year), rates of cesarean delivery overall and for dystocia remained the same (for overall cesarean delivery: adjusted relative risk, 0.8; 95% confidence interval, 0.6-1.2; for dystocia: adjusted relative risk, 1.0; 95% confidence interval, 0.7-1.6). Overall instrumental delivery did not increase (adjusted relative risk, 1.0; 95% confidence interval, 0.8-1.4), nor did the duration of the first stage and the active phase of labor (multivariate analysis; P >.1). However, the second stage of labor was significantly longer by about 25 minutes (P <.001). CONCLUSION: Epidural analgesia during labor does not increase the risk of cesarean delivery, nor does it necessarily increase oxytocin use or instrumental delivery caused by dystocia. The duration of the active phase of labor appears unchanged, but the second stage of labor is likely prolonged. (Am J Obstet Gynecol 2001;185:128-34).

Adult↗

PubMed2001

Falls Clinics in Australia: a survey of current practice, and recommendations for future development.

The aim of this study was to identify common themes and differences in structure and function of Falls Clinics in Australia, to provide a framework for planning future activity. A paper-based survey was circulated to 20 identified Falls Clinic services throughout Australia in late 2000. Fifteen responses (75%) were received, although two of the 15 Clinics were not operating at the time of the survey, and so their responses were not included. Nine of the Clinics had commenced operation since 1998. Staffing commonly included a physiotherapist, geriatrician, and an occupational therapist, with the comprehensive multidisciplinary assessment process taking an average of 130 minutes. Although standard assessment tools were used by more than half of the Clinics, there were no universally applied assessment tools. Waiting lists for initial assessments ranged up to 16 weeks (average 6 weeks). Most Clinics instituted a number of management options themselves, but also used a range of existing community services to provide some of the planned interventions. Limited formal evaluation of the effectiveness of Clinics was reported. Recommended future activity included increasing staff levels and operating times for Clinics to more adequately meet identified need, increased networking and data sharing between Clinics, and a greater emphasis on research and staff training. We conclude that the recent increase in the number of Falls Clinics around Australia has occurred in a relatively unstructured manner, with many differences in staffing, operation and evaluation. There is a need for improved communication and standardisation of core procedures and assessment tools to facilitate best practice in all Clinics, and to provide a framework for a systematic evaluation of the effectiveness of Falls Clinics in Australia.

Accidental Falls↗

PubMed2001

Striatal dopamine transporter binding in early to moderately advanced Parkinson's disease: monitoring of disease progression over 2 years.

Imaging of striatal dopamine transporter binding allows differentiation between patients with Parkinson's disease and controls. We investigated the use of this technique to monitor disease progression. We used N-(3-iodopropen-2-yl)-2beta-carbomethoxy-3beta-(4-chlorophenyl) tropane (IPT) and single photon emission computed tomography (SPECT) to determine dopamine transporter function in eight patients with Parkinson's disease Hoehn and Yahr stage I to III over time. Patients were recruited from the movement disorder clinic and were studied at entry and after a follow-up period of 1 and 2 years. Specific striatal IPT binding was measured with a manual region of interest technique. At entry, all patients showed a reduction of striatal IPT uptake of approximately 50% compared to controls, with a mean striatum to background ratio of 3.61 +/- 0.72 (controls, 7.34 +/- 1.18). Putamen to background ratios were initially measured as 2.42 +/- 0.74 and caudate to background ratios as 5.00 +/- 0.73 (controls, 6.46 +/- 1.22 for putamen and 8.58 +/- 1.36 for caudate). Specific striatal IPT binding decreased by a mean of 6.6% in the first year and another 5.3% in the second year. Changes of specific IPT binding over time were similar in caudate and putamen. In patients with clinically asymmetric disease, differences between the rate of decline in the ipsilateral and contralateral sides could not be detected. The findings suggest that IPT SPECT can quantify the reduction of dopamine transporter binding over time. This technique seems to be a useful tool in monitoring the intra-individual progression of dopaminergic cell loss in patients with Parkinson's disease and may help to follow the effects of putative neuroprotective drugs in future clinical trials.

Adult↗

PubMed2001

[Intestinal duplication. A rare disease in the differential diagnosis of cystic abdominal tumors].

Intestinal duplications are described as uncommon congenital anomalies rarely diagnosed in adults. A case of young woman with obscure abdominal symptomatology is demonstrated. After investigation the cause of it was disclosed surgically. During operation a cystic ileal duplication was exposed and resected. Despite of difficulties calling for another operation, the case was successfully solved. Based on the author's experience some aspects of these diseases--etiopatogenesis, symptoms, possibilities of examination and complications are discussed and surgery as the main treatment is emphasized.

Abdominal Neoplasms↗

PubMed2000

Both pain and EEG response to cold pressor stimulation occurs faster in fibromyalgia patients than in control subjects.

Pain-evoked brain potentials elicited by laser stimulation have been repeatedly shown to be abnormal in fibromyalgia syndrome. However, to our knowledge this is the first study assessing enduring (cold pressor) pain and correlated EEG changes in fibromyalgia. EEG power and subjective pain ratings during the cold pressor test were analyzed and contrasted with tasks not involving sensory stimulation (rest, mental arithmetic and pain imagery) in 20 patients with fibromyalgia and 21 healthy control subjects. Fibromyalgia patients both perceived pain and judged pain as intolerable earlier than control subjects, while pain intensity ratings and EEG power changes during subjective awareness of pain were similar in both groups. In patients and control subjects, pain was correlated with a rise in delta, theta and beta power. EEG power spectra during pain imagery and mental arithmetic were significantly different from those observed during the cold pressor test. In conclusion, fibromyalgia patients seem to process painful stimuli abnormally in a quantitative sense, thus producing both the sensation of pain, as well as the associated EEG patterns, much earlier than control subjects. However, the quality of the pain-associated EEG changes seems similar.

Cold Temperature↗

PubMed2000

[The interphase fluorescence in situ hybridization (I-FISH) technique in patients with chronic lymphatic leukemia (CLL)].

BACKGROUND: Trisomy 12 was found to be the most frequent chromosomal aberration identified by conventional cytogenetic studies of bone marrow cells and peripheral lymphocytes of patients with CLL. Molecular-cytogenetic techniques which enable examination of dividing and/or non-diving interphase nuclei (I-FISH), proved existence of other chromosomal abnormalities, mainly deletions, which could have in CLL patients relation to the origin, course and prognosis of the disease. METHODS AND RESULTS: During the last two years bone marrow chromosomes of all patients with CLL were examined by G-banding and by I-FISH. The numerical changes of chromosome 12 were followed by centromeric DNA probe in dividing and non-dividing cells. The small deletions were ascertained by locus specific probes for 13q14 (Rb gene), 17p13 (p53 protein) and 11q23 (MLL gene). These genes are responsible for cell division and their function is probably in connection with neoplastic process. It is of interest whether numerical and structural chromosomal rearrangements are primary or secondary changes and what is their impact on etiology of CLL. 93 patients were examined by DNA prove CEP12 and trisomy 12 was found in 24 of them (25.8%), the range of the clone was 2.5-75.5% of the screened cells. Deletion del(13)(q14) was examined by probe D13S319 in 73 patients and proved in 24 of them (32.8%), pathological clone ranged 2.5-80.0% of the cells. Deletion del(17)(p13) was found in 14 patients out of 61 examined by probe LSI p53 (22.9%). The extent of the clone was 2.5-34.0% of examined cells. Deletion 11q23 was not ascertained in any of 11 patients by means of probe LSI 11q23 (MLL). All probes used for FISH were manufactured by VYSIS. CONCLUSIONS: FISH is very sensitive method, suitable for molecular-cytogenetic examination of leukemic patients. With I-FISH the deletion of 13q14 was ascertained as the most frequent chromosomal aberration in series of 73 patients with CLL. We continue to increase the number of patients screened by I-FISH with all eligible DNA probes and start the prospective study on patients with chromosomal pathology. We will correlate the immunophenotype, morphology, clinical course and prognosis with karyotypic findings.

Adult↗