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Biomedical subjects

I Langer

Publications and source records attributed to I Langer.

At least 37 records · Page 2Linked to original sources
PubMed2000

Expression of vascular endothelial growth factor (VEGF) and VEGF receptors in human neuroblastomas.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a specific endothelial cell mitogen that stimulates angiogenesis and plays a crucial role in tumor growth. The aim of the present study was to evaluate the expression of VEGF and of its two high-affinity tyrosine kinase receptors (KDR and Flt-1) in neuroblastoma surgical samples and cell lines. PROCEDURE: The VEGF, KDR, and Flt-1 mRNA expression in neuroblastoma surgical samples and cell lines was studied by RT-PCR. The receptors were identified in [(125)I]VEGF binding and in functional studies (effect on cell growth). VEGF production by neuroblastomas was investigated by the ELISA method. RESULTS: It was possible to observe the mRNAs encoding for VEGF and its two receptors in some of the surgical specimens examined, including most of the high-grade tumors. It was also possible to demonstrate that the SK-N-BE cell line expressed VEGF, KDR, and Flt-1 mRNAs as well as biologically active receptors: The cells bound [(125)I]-VEGF, and their growth was stimulated by exogenous VEGF. Moreover, VEGF protein could be detected in their culture conditioned medium. CONCLUSIONS: These results suggest that, in addition to its effect on angiogenesis, VEGF may affect neuroblastoma cell growth directly and could be an autocrine growth factor.

Child↗
PubMed2000

[The Advanced Breast Biopsy Instrumentation (ABBI) for evaluation of mammographically suspicious, non-palpable findings of the breast: a reliable diagnosis with minor therapeutic potential].

BACKGROUND: Stereotactic biopsy techniques supersede conventional hook-wire localization followed by open excision to clarify the dignity of nonpalpable mammographic lesions. The advanced breast biopsy instrumentation (ABBI) allows stereotactically guided excision of a specimen up to 20 mm in diameter on an outpatient basis under local anaesthesia. METHODS: Demographic information, mammographic and pathological findings, complications, subsequent interventions and sensitivity as well as efficiency of a series of 144 planned ABBI procedures were documented (largest published single institution series). RESULTS: The ABBI procedure was successfully performed in 93.8% (135/144); accurate diagnosis was made in 99.3% (134/135), sensitivity for malignant lesions was 96.9% (31/32) and morbidity was 1.5%. Consistent with other published series margins of the biopsy cylinder containing a malignant lesion were involved in 83.9% (26/31). CONCLUSIONS: Excisional biopsy using the ABBI system is a reliable diagnostic tool with a low incidence of morbidity. The therapeutic use is of limited potential.

Adult↗
PubMed2000

[Significance of endoscopic axillary dissection in invasive breast carcinoma after introduction of the "sentinel lymph node" method].

UNLABELLED: Axillary clearance provides prognostic information, determines adjuvant therapy and reduces axillary recurrences. However significant morbidity may follow axillary dissection. Patients with small tumors (pT1a-c) may benefit from new less invasive (endoscopic lymph node dissection) or more selective (sentinel lymph node biopsy) axillary procedures which recently have been introduced. In this prospective study the axilloscopic approach was evaluated. PATIENTS AND METHODS: 55 clinically node negative patients (mean age: 60 years [30-86]) had endoscopic axillary surgery by one single surgeon (1.1996-6.1998). After axillary liposuction individual lymph nodes (level I + II) were identified and removed under direct vision by means of a laparoscope (successful procedure in 95%; n = 52). Patients were followed every four months according to a institution based follow up protocol. Results of 51 patients (1 refused) were analyzed after a median follow up of 22 (7-37) months by self-evaluation questionnaire, interview and clinical examination (including: range of motion of the shoulder joint, circumferences of the upper extremities). RESULTS: An average of 13.3 (5-25) lymph nodes was endoscopically removed. Patients (n = 16; 31%) had involved nodes with a mean of 3.1 nodes positive per individuum. Seromas necessitated needle aspiration in 8 patients (15%). There were no hematomas and one low grade infection (2%). After a median follow up period of 22 (7-37) months no axillary relapse but one trocar site implantation metastasis (1/55, 2%) was detected and resected. No lymph edema was observed. Early range of motion of the shoulder joint was excellent. CONCLUSION: This technique allows the removal of an adequate number of lymph nodes for staging as well as for regional control. The morbidity is low and the medium-term follow-up results are promising. The atraumatic and very well tolerated endoscopic axillary dissection is being replaced by the selective sentinel lymph node procedure.

Adult↗
PubMed2000

[Validation study of the sentinel lymph node (SLN) method in invasive breast carcinoma. Personal data and review of the literature].

BACKGROUND: Axillary lymph node dissection (ALND) is an integral part in the therapy of breast cancer. Axillary lymph node involvement and tumour size are the most important prognostic factors. Restriction of ALND to level I and II (Berg) reduced high morbidity. The increasing proportion of patients with early breast cancer and negative axillary nodes led to a more selective method to avoid unnecessary ALND. The sentinel lymph node (SLN)--the first draining lymph node of a tumour--represents the status of the axilla. A negative SLN prevents from further completion ALND. PATIENTS AND METHODS: From 9/97 to 1/99 44 patients with invasive breast cancer underwent a prospective trial of lymphatic mapping with isosulfanblue and/or lymphoscintigraphy with 99m technetium-labelled human colloid. During the operation a hand-held gamma probe was used for detection. The SLN was removed selectively and examined by routine histopathology (H&E) and immunohistochemistry (IHC). ALND of level I and II was performed in all patients for correlation. RESULTS: The SLN were identified in 41 of 44 patients (93%). 2.4 SLN per patient were harvested, overall 17.6 axillary lymph nodes. Of the 41 patients, 21 patients had positive, 20 patients negative SLN. In the 20 patients with negative SLN only one patient (5%) had metastatic disease on complete dissection (negative predictive value of 95%). In 17 patients with positive axillary lymph nodes 16 were found to have positive SLN, only one SLN was negative (false negative rate of 5.9%). In two of 41 patients micrometastases were detected by IHC. Lymphoscintigraphy revealed drainage to the axilla and internal mammary nodes in two of 28 cases (7%). SUMMARY: Our validation study proves the reproducibility and reliability of the SLN procedure. A multidisciplinary approach is indispensable. The SLN procedure has the potency for becoming the selection criterion whether to perform an ALND or not. Multiple sections and IHC staining improve the detection rate of metastatic disease. Ongoing long time investigations will determine the impact on overall survival. Our own data are discussed in an extended review of the literature.

Adult↗
PubMed2000

Sell now. New pension law encourages early sale.

The time to begin planning your retirement is long before you actually quit working. Changes in the federal pension law allow you to shorten that planning timetable. By taking advantage of these changes, you will be preparing for a better life for yourself and your entire family.

Humans↗
PubMed1999

Mechanisms of tumor angiogenesis and therapeutic implications: angiogenesis inhibitors.

Angiogenesis is the development of new blood vessels from the existing vascular bed. In normal conditions this tightly regulated process occurs only during embryonic development, the female reproductive cycle and wound repair. In contrast, in pathological conditions such as malignant growth, atherosclerosis and diabetic retinopathy, angiogenesis becomes persistent due to an imbalance in the interplay between the positive and negative regulatory signals controlling the process. Thus, the control of tumor neovascularization may lead to new therapeutic approaches. Indeed, several anti-angiogenic drugs are currently undergoing preclinical characterization and/or clinical investigation. Recent achievement has clarified the mechanisms of action leading to pathological angiogenesis and has highlighted the role of hypoxia, growth factors, growth factor-receptors, enzymes and cell adhesion molecules involved in the process. This knowledge has permitted the design of receptor antagonists, adhesion molecule blockers and new targeted vascular approaches including gene therapy.

Animals↗
PubMed1998

Learning at the computer: evaluation of an intelligent tutoring system.

The aim of the study was to test the efficacy of a new courseware. In a pre and post test frame, students were given the software to be used during one semester. A significant increase in the students' general study motivation was shown at the end of the semester. A change in the use and attitudes towards computers could not be observed. In a follow-up survey at the end of the semester, the students stated that the program was indeed helpful and useful but that they have had difficulties with the program's technical aspects and the general use. Furthermore, the results show that the majority of the participating students accepted the program's content, the general study motivation was high and the students showed a significant increase in learning gains, determined by the differences from pre and post test values. Especially students with low pre test values seemed to profit from the additional use of learning material, resp. the presented courseware. At the end of the semester the students with low and middle pre test results showed an increase in performance as well as an alignment in the performance for diagnosing rheumatological diseases to the students of the upper third pre test results.

Cardiology↗
PubMed1997

Ramipril prevents endothelial dysfunction induced by oxidized low-density lipoproteins: a bradykinin-dependent mechanism.

We wished to determine whether the acute toxic effects of oxidized LDL are attenuated in aortas isolated from rats chronically treated with an angiotensin-converting enzyme (ACE) inhibitor. In aortic rings incubated with human oxidized LDL (300 microg/mL), the endothelium-dependent relaxations to acetylcholine were attenuated, but not those to A23187 and to nitroprusside. This toxic effect of oxidized LDL was completely prevented in preparations coincubated with oxidized LDL and the nitric oxide (NO) precursor L-arginine (0.3 mmol/L). In aortas isolated from rats orally treated for 6 weeks with 10 mg/kg ramipril (group 1) or 1 mg/kg ramipril (group 2), this toxic effect of oxidized LDL was also markedly attenuated. In contrast, in aortas isolated from rats cotreated with ramipril (10 mg/kg) for 6 weeks and subcutaneous injections of Hoe 140 (a B2 kinin antagonist), 500 microg/kg per day for the last 2 weeks (group 3) or from rats orally treated for 6 weeks with losartan (an AT1-type angiotensin II receptor antagonist), 20 mg/kg (group 4), the inhibitory effect of oxidized LDL on acetylcholine-induced relaxations was similar to that observed in the control group (group 5). Moreover, long-term treatment with ramipril increased relaxations to acetylcholine in groups 1 and 2 and also relaxations to A23187 and aortic cGMP content in group 1, suggesting an enhanced NO availability. Thus, the protective effect of long-term ACE inhibition against the acute vascular toxicity of oxidized LDL is bradykinin dependent and seems to involve a facilitation of NO release via endothelial B2 kinin receptors.

Acetylcholine↗
PubMed1996

[Preperitoneal prosthesis implantation in surgical management of recurrent inguinal hernia. Retrospective evaluation of our results 1989-1994].

Recurrent inguinal hernia represents a great problem in surgery given the frequency of this operation, with a recurrence rate of 0.5-8%. Re-recurrence after repair without implantation of a prosthesis occurs in 1-23% of cases. We analyzed our results of patients with recurrent inguinal hernia, operated according to the method of Stoppa. Between 1989 and July 1994 there were 58 operations upon 55 patients with an average age of 65 years, 79% of whom had unilateral and 21% bilateral hernias. 89% of all patients underwent surgery because of a recurrent inguinal hernia. A Marlex mesh was used in 79% of the case. All patients were followed up (mean 35 months, minimum 12 months). Early complications consisted in one hematoma (1.7%), which had to be drained, as well as one early recurrence (1.7%). No infections were observed. The overall recurrence rate was 12%. However, 60% of all recurrences occurred in the few first years after introduction of this technique at our clinic; with growing number of operations and experience with Stoppa's technique, we obtained a recurrence rate of 6-7% per year. In our opinion, supported by the results of other studies, Stoppa's technique is a successful method in the treatment of recurrent inguinal hernia.

Adult↗
PubMed1994

Aortic valve replacement in elderly patients with aortic stenosis.

OBJECTIVE: To assess the risk of aortic valve replacement and long-term follow-up in elderly patients with dominant aortic stenosis. DESIGN: Retrospective analysis of patients who had aortic valve replacement over a 10 year period and were routinely seen in an outpatient clinic. SETTING: University hospital. PATIENTS: 93 patients aged > or = 60 and 47 patients > or = 70 years with symptomatic aortic stenosis undergoing aortic valve replacement. MAIN OUTCOME MEASURES: Early and late mortality in different age groups. Influence of preoperative signs and symptoms on overall outcome. RESULTS: The proportion of patients older than 70 years increased from 11% in 1978 to 54% in 1986. Perioperative mortality was 3.6% and mortality after 2 and 5 years was 9% and 13% respectively. Survival was similar (85% and 83%, respectively) in patients aged 60-69 years (group 1, n = 93, mean age 64.5 (2.7) and patients aged > or = 70 years (group 2, n = 47, mean age 72.6 (2.5)). Additional coronary artery disease and coronary bypass grafting did not significantly affect survival. The cardiothoracic ratio was inversely related to survival (Cox regression, p < 0.05). Preoperative symptoms (syncope, angina pectoris, and dyspnoea) were similar in both patient groups. After a mean (SD) follow up of 51 (33) months 96% of surviving patients were in NYHA functional class I or II with no difference between the two age groups. Similarly, the cardiothoracic ratio and Sokolow index decreased to near normal values in both age groups. CONCLUSION: The risk of aortic valve replacement in patients with dominant aortic stenosis is low and not significantly influenced by age. Therefore replacement may be performed without increased risk in elderly patients and with a good long-term outcome.

Age Factors↗
PubMed1987

[The visual field of pseudophakic patients. Perimetric and statistical study].

One hundred and twenty two visual fields were studied in 98 pseudophakic subjects, using cinetic perimetry according to Goldmann, in order to plot the internal (I1), medium (I2) and peripheral (I4) isopters. Computerized processing of data provided average results, allowing the following conclusions: In general, 20% of the total surface is lost in pseudophakia. This loss, as a consequence of prismatic effects of lenses, involves the internal isopters (26%) rather than the peripheral isopters (15%). Individually, these data can be modified by the location of the lens or by the diameter of its optical part: the more anterior or the smaller is the optical part, the narrower does the visual field become. Additional correction, particularly if exceeding 2 diopters is a supplementary factor of reduction. The perimetric consequences of pseudophakia are functionally latent. Nevertheless, the prismatic effects of intraocular lenses could account for the difficulties met in examination of peripheral fundus.

Adolescent↗
PubMed1986

Type III collagen aminopropeptide levels in serum of patients with progressive systemic scleroderma.

Sera from 101 patients with progressive systemic scleroderma were analyzed for circulating aminopropeptides of type III collagen using a radioimmunoassay which measures the intact and degraded forms (Fab assay). About 41% of the patients were found to have values above the normal range. A good correlation was observed between elevated levels of aminopropeptides and the degree of involvement of the skin and internal organs in the patients. Most patients (89%) with an active progression of the disease but not those in a stationary phase showed increased serum levels of aminopropeptides. Treatment with corticosteroids apparently normalized the levels of aminopropeptides. Only minor changes were observed with an antibody-based radioimmunoassay which measures primarily the intact form of the aminopropeptide.

Adult↗
PubMed1984

Release of amino-terminal procollagen peptides in paraquat-induced acute pulmonary fibrosis.

Acute pulmonary fibrosis following intoxication with paraquat is characterized by increased collagen synthesis and deposition in the lungs. In the present study, a chronic lung lymph fistula preparation in sheep was used to investigate the changes in procollagen type III peptide level in the lung lymph in acute pulmonary distress associated with paraquat application. The procollagen type III peptide is supposed to be an indicator of the changing biosynthetic pattern of pulmonary collagen in lung fibrosis. All animals tested showed a progressive pulmonary distress following the application of paraquat characterized by increasing lymph flows and lymph protein flows which monitored the microvascular membrane damage. In parallel to these findings, procollagen peptide levels in the lymph fluid increased, even before manifest biochemically or histologically detectable pulmonary fibrosis occurred. The present results suggest that the release of procollagen type III peptides into lymph fluid is an early indicator of beginning fibrotic tissue disarrangement, even before completed pulmonary fibrosis can be detected by common tissue analysis.

Acute Disease↗
PubMed1983

Serum and urine analysis of the aminoterminal procollagen peptide type III by radioimmunoassay with antibody Fab fragments.

A radioimmunoassay based on antibody Fab fragments was developed for the aminoterminal peptide Col 1-3 of bovine type III procollagen. This assay does not distinguish the intact aminopropeptide Col 1-3 from its globular fragment Col 1. Parallel inhibition profiles were observed with human serum and urine allowing the simultaneous quantitative determination of intact and fragmented antigens in these samples. Most of the material has a size similar to that of fragment Col 1 indicating that the aminopropeptide is degraded under physiologic conditions. The concentration of aminopeptide in normal sera was in the range 15-63 ng/ml. Daily excretion was found to be in the range 30-110 micrograms. More than 50% of patients with alcoholic hepatitis and liver cirrhosis showed elevated serum levels of aminopropeptide by the Fab assay. Elevated concentrations were detected more frequently with an antibody radioimmunoassay which measures mainly the intact form of the aminopropeptide. It is suggested that analysis of patients material by both assays could improve their diagnostic application.

Adolescent↗
PubMed1981

[Supracondylar humeral fractures in infants and small children].

The question of separation of the epiphyses in infants and small children of the type Salter-Harris affecting the distal humerus is discussed. The indications for open reduction of the distal humerus epiphyseal separation is rarely indicated and should only be utilised when there is associated injury to the nerves of vessels or a total disruption of the chondyle. Provided that accurate re-position and fixation can be performed, the prognosis of this injury is satisfactory.

Child, Preschool↗