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Biomedical subjects

H Becker

Publications and source records attributed to H Becker.

At least 19 recordsLinked to original sources
PubMed1992

Immunosuppression by human gangliosides: I. Relationship of carbohydrate structure to the inhibition of T cell responses.

Causes of cellular immunodeficiency frequently associated with cancer remain poorly understood. One possible mechanism is tumor cell membrane shedding of immunosuppressive molecules, such as the sialic acid-containing glycosphingolipids, gangliosides. To explore this interesting hypothesis and establish structure-activity relationships, we examined the effects of a series of highly purified human gangliosides on T cell function. In all, ten individual molecular species of two major biosynthetic pathways were compared for their ability to inhibit human T cell proliferative responses. They include GM1, GD1a, GD1b, and GT1b (the predominant normal brain species), and GM4, GM3, GM2, GD3, GD2 and GQ1b. Strikingly, each HPLC-purified molecule, from the simplest monosialoganglioside to the most complex polysialoganglioside, had potent inhibitory activity; even the ganglioside with the most elemental carbohydrate structure (GM4, one sialic acid linked to a monosaccharide) strongly inhibits T cell proliferative responses to tetanus toxoid (ID90 = 1.5 microM). The data also reveal a complex interplay between elements of oligosaccharide structure in determining immunosuppressive activity. Sialic acid is critical to maximal activity, and (i) immunosuppression is most potent in gangliosides containing a terminal sialic acid. (ii) Total desialylation almost abolishes activity and (iii) partial alteration (lactone formation) reduces activity. (iv) Activity is generally but not always higher with higher numbers of sialic acid residues/molecule, and (v) some larger neutral glycosphingolipids retain measurable immunosuppressive activity. Overall, the potent inhibition by gangliosides supports the hypothesis that shedding of these molecules by tumors creates a highly immunosuppressive microenvironment around the tumor, thereby inhibiting the function of infiltrating host leukocytes and contributing to diminished T cell responses in cancer.

Carbohydrate Conformation↗
PubMed1992

[The echocardiographic demonstration of a right atrial thrombus and its embolization into the lung].

A 43-year-old man was hospitalized because of extensive bilateral pulmonary tuberculosis. After several weeks of tuberculostatic treatment--at first applied orally, then because of nausea and vomiting parenterally via a central venous catheter--he acutely developed nocturnal dyspnoea and symptoms of shock requiring artificial ventilation. Echocardiography demonstrated dilatation of the right ventricle and a large floating thrombus in the right atrium. During the examination complete displacement of the worm-like thrombus into the pulmonary artery was observed echocardiographically. Despite anticoagulation and immediate operation the patient died 2 days later of protracted shock. The thrombus was found to have been formed in the superior vena cava after placement of the central venous catheter.

Adult↗
PubMed1992

Role of octreotide in the prevention of postoperative complications following pancreatic resection.

Though morbidity and mortality rates following pancreatic resection have improved in recent years, they are still around 35% and 5%, respectively. Typical complications, such as pancreatic fistula, abscess, and subsequent sepsis, are chiefly associated with exocrine pancreatic secretion. In order to clarify whether the perioperative inhibition of exocrine pancreatic secretion prevents complications, we assessed the efficacy of octreotide, a long-acting somatostatin analogue. We conducted a randomized, double-blind, placebo-controlled, multicenter trial in 246 patients undergoing major elective pancreatic surgery. Patients were stratified into a high-risk stratum (limited to patients with pancreatic and periampullary tumors) or low-risk stratum (patients with chronic pancreatitis). Patients received octreotide (3 x 100 micrograms) or placebo subcutaneously for 7 days perioperatively. Eleven complications were defined: death, leakage of anastomosis, pancreatic fistula, abscess, fluid collection, shock, sepsis, bleeding, pulmonary insufficiency, renal insufficiency, and postoperative pancreatitis. Two hundred patients underwent pancreatic head resection, 31 patients underwent left resection, and 15 patients had other procedures. The overall mortality rate within 90 days was 4.5%, with 3.2% in the octreotide group and 5.8% in the placebo group. The complication rate was 32% in the patients receiving octreotide (40 of 125 patients) and 55% in patients receiving placebo (67 of 121 patients) (p less than 0.005). In the patients in the high-risk stratum, complications were observed in 26 of the 68 (38%) patients treated with octreotide and in 46 of 71 (65%) patients given placebo (p less than 0.01). Whereas in patients in the low-risk stratum, the complication rate was 25% (14 of 57 patients) in those treated with octreotide and 42% (21 of 50 patients) in patients given placebo (p = NS). The perioperative application of octreotide reduces the occurrence of typical postoperative complications after pancreatic resection, particularly in patients with tumors.

Double-Blind Method↗
PubMed1992

Down syndrome complicated by brain tumors: case report and review of the literature.

This report concerns a 24-year-old male patient with Down syndrome, complicated by a benign but true neoplastic lesion of a differentiated papilloma of the choroid plexus which simultaneously displayed a dysgenetic character. A review of the literature revealed a lack of single case reports of Down syndrome with brain tumors, which may reflect chance occurrence; however, the brain tumors in Down syndrome patients are characterized by their dysontogenetic or dysgenetic character.

Adult↗
PubMed1992

Imbalance of CD4+ lymphocyte subsets in patients with mixed connective tissue disease.

CD4+ (helper/inducer) T lymphocyte subsets were studied in the peripheral blood from patients with mixed connective tissue disease (MCTD) by double-labelling immunofluorescence. The proportion of CD4+CD45RA+ cells was higher (P less than 0.01) when compared with controls, whereas CD4+CD29+ cells were markedly diminished (P less than 0.001). CD4+CD29+ cells were lower than in patients with progressive systemic sclerosis who were studied in parallel. Upon stimulation with phytohaemagglutinin, CD4+ cells from MCTD patients showed a strong reactivity to acquire the CD29+ phenotype. Expression of high levels of CD29 and other adhesion molecules might lead to facilitated localization of CD4+ cells to inflamed tissue. It is suggested that an increased responsiveness of CD4+ cells to activation signals in vivo and accumulation of CD4+CD29+ cells at tissue sites could result in depletion of this cell subset in the peripheral blood of patients with MCTD.

Adult↗
PubMed1992

Primitive neuroectodermal tumor arising in the skin. Differentiation from neuroendocrine carcinoma of the skin.

We report a 25-year-old male patient with primitive neuroectodermal tumor presenting as a subcutaneous tumor on the right buttock, which was initially diagnosed as neuroendocrine carcinoma of the skin. Subsequently, local recurrence and metastatic spread to the lung occurred. The tumor was resistant to highly aggressive chemotherapy. The patient died 6 months later with severe pulmonary and lymph node involvement.

Adult↗
PubMed1992

Transplantation of human benign hyperplastic prostate tissue into nude mice: first results of systemic therapy.

Xenografts of human benign hyperplastic prostate tissue (BPH) have been established as a model for the investigation of the etiology of BPH. In this paper it is our aim to answer the question of whether this model is useful for the established therapy of the disease. Additionally we try to evaluate the value of a commonly used plant extract for the therapy of BPH. Is there any influence of the extract from Sabal serrulatum on the BPH tissue in our model? Human BPH tissue from 2 patients was transplanted into athymic nude mice and treated with three different regimens. Animals of group I did not receive any treatment and served as control, in groups II and III the tissue was stimulated by application of silicone tubes containing crystalline 5 alpha-dihydrotestosterone and estradiol. Animals of group II additionally were treated orally with the lipophilic extract of S. serrulatum (contained in Prostagutt N), which is commonly used for the treatment of BPH clinically. Significant inhibition of tissue growth was observed in group III when compared to group II. In group I (control) atrophy of the graft was observed as expected. However, histologically no differences were visible between groups II and III. Our experiment shows a significant growth-inhibiting effect of the plant extract for human BPH tissue in our model (p less than 0.05). We conclude that the nude mouse model can be useful for the evaluation of systemic therapy modalities of human BPH and that the plant extract may have a certain value for clinical treatment, which is not only due to subjective criteria.

Animals↗
PubMed1992

Essential hypertension associated with neurovascular compression: angiographic findings.

According to the hypothesis of Jannetta, an arterial compression of the left root entry zone (REZ) of cranial nerves IX and X by looping arteries could play an important role in the pathogenesis of essential hypertension. In an initial anatomical study, the positions of the left vagus and glossopharyngeal nerves in the skull were radiographically determined in 10 cadavers. By using a pattern of REZ topography developed from this information, the angiographic findings in 107 hypertensive and 100 normotensive patients were then compared retrospectively. In 80% of the angiograms of the hypertensive patients that could be evaluated, an artery crossed the left REZ of cranial nerves IX and X. Most frequently, this was the posterior inferior cerebellar artery (35.3% of cases), followed by the vertebral artery (29.4% of cases) and the anterior inferior artery (19.1% of cases). In 9 cases (13%), both the posterior inferior cerebellar artery and the vertebral artery appeared in the REZ. Frequently, a larger diameter of the left vertebral artery was found. The angiograms of normotensive patients that could be evaluated revealed an artery in the REZ in only 34.5% of cases. Our results support the hypothesis that essential hypertension may be associated with neurovascular compression of the left REZ of cranial nerves IX and X.

Adult↗
PubMed1992

Are CAT-scans necessary for preoperative localization of insulinomas?

OBJECTIVES: Do CAT-scans provide useful information in terms of preoperative localization of insulinomas after a biochemical diagnosis is established or may CAT-scan imaging be safely abandoned? PATIENTS AND METHODS: CAT-scan results from 30 consecutive patients between 1980-1990 with established insulinomas were retrospectively evaluated with regard to actual tumour size (volume) and identification and localization as verified during surgery. RESULTS: In all patients, the tumours were easily detected by manual palpation during surgery, although the size of 67% of the tumours (n = 20) was less than 2.5 cm3. In only 7 patients (23%) the tumour had been correctly localized by computer tomography. Detected tumours were significantly larger than undetected tumours (median size 5.3 vs 1.3 cm3; p < 0.005). CONCLUSION: Despite the low sensitivity of computer tomography as documented in this study, all patients with an insulinoma were definitely cured after surgical intervention. Thus, CAT-scans are neither necessary nor helpful for preoperative localization of insulinomas.

Adult↗
PubMed1992

Coexpression of CD4 and CD8 on mitogen-activated peripheral blood T cells from children with asthma: possible involvement of interleukin 4.

Mononuclear cells were isolated from the peripheral blood of 28 asthmatic and 18 healthy children aged 3 to 16 years. The cells were stimulated with phytohemagglutinin for 96 hours. Activated cells were detected microscopically by MTT staining. Expression of cell surface antigens was detected by indirect immune fluorescence using CD4-specific and CD8-specific monoclonal antibodies. Results indicate an enhanced expression of CD8 on mitogen-activated T cells from asthmatic children compared with cells from healthy controls (median 43% versus 27%). Further experiments revealed that CD8 is coexpressed with CD4 on activated lymphocytes. Coexpression is significantly enhanced with lymphocytes from asthmatic patients compared with normal controls. In addition, interleukin 4 is able to enhance this coexpression with lymphocytes from healthy but not asthmatic children suggesting an in vivo preactivation of lymphocytes from asthmatic patients with interleukin 4.

Adolescent↗
PubMed1992

[Expression of low-affinity Fc epsilon receptors on circulating monocytes in patients with inflammatory rheumatic diseases].

In patients with scleroderma, high proportions of circulating CD23+ monocytes could be detected by FACS analysis as compared with controls. Supernatants obtained from lymphocytes yielded high amounts of interleukin-4-(IL-4-)like activity. The results suggest that IL-4 contributes to monocyte activation in scleroderma. There were no correlations with serum IgE, or numbers of naive and memory-CD4+ lymphocytes.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1992

Unusual features of multiple endocrine neoplasia.

In addition to the common presentations of the multiple endocrine neoplasia (MEN) syndromes, unusual organ involvement as rare manifestations of a single disease may occur. Among our patients we have identified four cases in which unusual features of MEN were present. In the first patient, bilateral adrenal cortical adenoma, parathyroid adenoma, multiple pancreatic tumors, and follicular thyroid carcinoma were observed. The second patient suffered from thymic carcinoid, parathyroid hyperplasia, gastrinoma, and pituitary adenoma. Additionally, one family was discovered in which medullary thyroid carcinoma (MTC), Hirschsprung's disease, and pheochromocytoma occurred and another family had MTC and ovarian cancer. Based on these observations, we stress the importance of screening for MEN syndromes in all patients with pathologic findings in any endocrine organ.

Adolescent↗
PubMed1992

[Liver function tests in a clinical comparison].

Various liver function tests were evaluated in regard to a quantitative estimation of the impairment of liver function related to the Child-Pugh classification in 32 patients with cirrhosis. Only the ICG-test revealed significant differences between healthy subjects and cirrhotic patients in stadium Child A, B and C. When ICG-dye retention values were plotted as a function of the individual score units of the Child-Pugh classification, a linear relationship with a correlation coefficient of 0.7 was obtained. In contrast to the ICG-test, the MEGX- and galactose elimination capacity (GEC)-test as well as static parameters of liver function (cholinesterase activity, prealbumin concentration, coagulation factor V and VII) resulted in less significant differentiation of the various Child classes. The MEGX-test, GEC, concentration of prealbumin, coagulation factor V and VII were only weakly correlated to the score units of the Child-Pugh index. The results of this study indicate that of all evaluated parameters only the ICG-test is suitable for objective and graduated analysis of liver function in patients with cirrhosis.

Cholinesterases↗
PubMed1992

Diagnostic immunohistochemistry of neuroblastic tumors.

Eighteen commercially available antibodies were applied to formalin-fixed, paraffin-embedded neuroblastomas (NBLs, n = 20), ganglioneuroblastomas (GNBLs, n = 7), and ganglioneuromas (GNs, n = 7) to assess their reliability as markers for neuroendocrine differentiation and degree of tumor cell maturation. Incubations with a monoclonal antibody to neuron-specific enolase resulted in positive reactions in all tumors, with consistently strong staining intensities in moderate and well-differentiated NBLs, GNBLs, and GNs. Antibodies to dopamine beta-hydroxylase and protein gene product (PGP) 9.5 reacted with all tumors except two NBLs. Among the antibodies directed to chromogranins and related proteins, HISL19 was most reliable (33/34) followed by endocrine granule constituent (EGC) (30/34), chromogranin A (LK2H10) (21/34), and chromogranin A + B (CGA + B) (19/34), in proving the existence of endocrine granules in tumor cells and Neurofilament (70 + 200 kD) immunoreactivity was demonstrated in all tumors except two undifferentiated NBLs. S-100 protein-immunoreactive cells were visualized with increasing frequency in highly differentiated GNBLs and GNs, whereas Leu 7 immunoreactivity was restricted to ganglioneuromas. We conclude that antibodies directed to neuron-specific enolase, HISL19, dopamine beta-hydroxylase, neurofilaments, EGC, LK2H10, and leucocyte common antigen represent markers that might be useful in the discrimination of GNBLs from non-neuroendocrine round and small cell tumors in routinely processed tissue. Antibodies to neuron-specific enolase, PGP 9.5, different chromogranins, neurofilaments, vasoactive intestinal peptide (VIP), and S-100 protein may help to determine the grade of tumor cell maturation.

Antibodies↗