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F Berger

Publications and source records attributed to F Berger.

At least 271 records · Page 15Linked to original sources
PubMed1993

Ratio confocal imaging of free cytoplasmic calcium gradients in polarising and polarised Fucus zygotes.

In the marine brown alga, Fucus, two poles are differentiated before cell division determining the future rhizoid or thallus. We have used a combination of the Ca(2+)-sensitive dye Calcium Green and the pH-sensitive dye SNARF monitored at pH-insensitive wavelengths to obtain confocal ratio images of free cytoplasmic calcium distribution at different stages in polarising Fucus zygotes. These dyes have the advantage that they can be used in most confocal microscopes and their longer excitation wavelengths greatly reduce autofluorescence problems. Dyes of varying molecular weights (free acid form, 10,000 mol.wt or 70,000 mol.wt dextran-conjugated) were pressure microinjected into early zygotes which were allowed to polarise in unidirectional light. Dextran-conjugated dyes remained non-compartmentalised and fluorescence could be monitored for up to 3 days following microinjection. Currently we have been able to detect Ca2+ gradients at the tip of the rhizoid, confirming earlier results. Localised Ca2+ elevations have also been observed at the rhizoid pole of the polarising zygote before the onset of rhizoid germination. Limitations of this technique and the significance of these Ca2+ gradients are discussed.

Benzopyrans↗
PubMed1993

Wegener's granulomatosis with antiproteinase-3 antibodies occurring after Hodgkin's disease.

We describe the first association between Hodgkin's lymphoma and Wegener's granulomatosis, heralded by renal involvement. A 43-year-old man developed rapidly progressive glomerulonephritis requiring chronic hemodialysis 8 months after remission of Hodgkin's lymphoma. At that moment, no extrarenal involvement was found, despite extensive investigation. Antineutrophil cytoplasm antibodies were positive, without specificity for proteinase-3 or myeloperoxydase. Six months after beginning hemodialysis, multiple pulmonary nodules appeared, along with rapid clinical worsening. A surgical biopsy was performed which disclosed a giant cell granuloma. Antimyeloperoxydase antibodies remained negative, whereas proteinase-3 antibodies became positive. Wegener's granulomatosis was diagnosed and treatment with cyclophosphamide and steroids was started. Clinical and radiological improvement occurred promptly. Eleven months after treatment, both Wegener's disease and Hodgkin's lymphoma remained in remission.

Adult↗
PubMed1993

[Veno-occlusive disease after liver transplantation. Association of acute cellular rejection and toxicity of azathioprine].

Azathioprine vascular hepatotoxicity has been described mainly after renal transplantation. We report a new case in a patient who developed veno-occlusive disease of the liver 3 weeks after liver transplantation; regression of lesions were observed after discontinuation of azathioprine therapy. In this case, azathioprine hepatotoxicity may have been enhanced by a previous episode of severe, acute rejection prevailing in the hepatic veins. After liver transplantation, the diagnosis of azathioprine hepatotoxicity is difficult but should be suspected in the presence of non-inflammatory small hepatic veins lesions. Early withdrawal of the drug is mandatory for complete recovery.

Acute Disease↗
PubMed1993

[Clinical study of 12 cases of malignant non-Hodgkin's lymphoma of the orbital region].

Over an 8-year period in the Departments of Hematology, Ophthalmology and Internal Medicine of our hospital, 12 cases of orbital and adnexal malignant non-Hodgkin's lymphoma were reported. Diagnostic elements varied, including local tumefaction, watering eyes, uveitis, and unexplained, long-term fever. Nine patients had primary paraocular lymphomas involving either orbital structures, the lacrimal gland or the eyeball, but after appropriate staging, the disease was found to be disseminated in 5; the 3 other cases were secondary orbital lymphomas. Intermediate or high grade histological types were predominant (9 patients) in our series. Radiation therapy, alone or combined (5 patients) with chemotherapy, was administered in 8 cases; other treatments consisted of chemotherapy (2 cases) or steroids (2 cases). Evolution was poor, with only 4 patients surviving at 34-180 months of follow-up. The main prognostic factors were tumor stage and histological grade. The clinical characteristics of this group are compared to those reported in the literature.

Adult↗
PubMed1993

Electrophysiological characterization of class III activity of a verapamil derivative in guinea-pig cardiac tissues.

In isolated guinea-pig papillary muscle ([K+]o: 4.7 mmol/l, stimulation rate: 1 Hz) the verapamil derivative NN-bis-(3,4-dimethoxyphenethyl)-N-methylamine)-HCl (YS035; 0.3-100 mumol/l) increased the action potential duration measured at 90% repolarization level (APD90) up to 132% of control and enhanced the force of contraction (Fc) up to 125% of control while resting potential (RP) and the maximum upstroke velocity (Vmax) remained nearly unchanged. At 300 mumol/l YS 035, the membrane became depolarised and action potentials could no longer be elicited. These effects were reversed during wash-out. The increase of ADP90 was largest at 0.05 Hz, and the drug-induced effect continuously declined with an increase in stimulation frequency to 2 Hz. Control ADP90 was correlated to the absolute increase of ADP90 (r = 0.84). In atrial muscle the effect of YS 035 on APD90 was more pronounced than in papillary muscle. The Vmax of slow responses ([K+]o: 27 mmol/l, [Ba2+]o: 0.5 mmol/l) was not affected by concentrations as high as 30 mumol/l YS 035, whereas APD90 was enhanced. An increase in the stimulation rate (0.05 to 0.33 Hz) induced only a small decrease of Vmax at 100 mumol/l YS 035. According to this electrophysiological characterisation YS 035 shows Class III antiarrhythmic properties.

Action Potentials↗
PubMed1992

[Lymphoproliferative syndromes associated with Epstein-Barr virus in transplantation].

We report 23 cases of lymphoproliferative diseases which occurred among 2,100 patients with kidney or combined kidney+pancreas transplant. Eleven patients developed a severe diffuse disease within the first 3 months post-transplantation; immunoblastic B cells of recipient origin infiltrated the bone-marrow, transplanted organs, liver, spleen, lymph nodes, lungs, and brain; immunoglobulin abnormalities with fever, leuko-thrombocytopenia and liver dysfunction constituted the symptoms; all patients received anti-lymphocyte globulins; 9 patients were also treated with cyclosporin. Three out of 6 tumors analysed were monoclonal. Epstein-Barr virus was present in 3 lesions analysed. Treatment consisted of cessation of immunosuppressive therapy. Nine patients died with lactic acidosis. Five patients had a less severe form. Seven patients had solid tumors involving the tonsils, lungs (2), lymph nodes (2), and bladder, 8 months after transplantation. All patients received cyclosporin; 4 also received anti-lymphocyte globulins and 3 OKT3. Tumor cells were immunoblasts expressing B cells markers at a late stage of B cell differentiation; 4 tumors were monoclonal. C myc was negative. Treatment consisted of cessation of immunosuppressive therapy, antiviral agents, and monoclonal antibodies (mAb): anti-CD21 and anti-CD24 mAb therapy was followed by cure of the lymphoma in 1 patient, by transient remission in a second one and by failure in the third patient. Two patients had a recurrence of the lymphoma and received chemotherapy; 2 patients died of the lymphoma, 1 died of unrelated cause; 4 are alive, 3 of them having a good graft function.

Antigens, CD↗
PubMed1992

[Malignant endocrine tumor of the pancreas associated with high blood thyrocalcitonin levels].

A case of thyrocalcitonin-secreting endocrine tumour of the pancreas is reported. Endocrine pancreatic tumours are neoplasias evolving over a long period; most of them are multisecreting, usually with a predominant secretion responsible for clinical symptoms. In this particular case the retrospective diagnosis of a thyrocalcitonin-secreting tumour of the pancreas was made by immunocytochemical study of the pancreatectomy specimen. One year after pancreatectomy, the persistence of clinical signs and a plasma thyrocalcitonin level higher than 25,000 pg/ml led to the discovery of a liver metastasis. An immunocytochemical study of the segmental hepatectomy specimen showed a single population of thyrocalcitonin-secreting cells identical with those found in the pancreatic tumour. In this context, radioimmunological assays of peptides and immunocytochemistry seem to be the best diagnostic methods.

Aged↗
PubMed1992

Electrophysiological characterization of histamine receptor subtypes in sheep cardiac Purkinje fibers.

The histamine-receptor-subtype-mediated effects on action potentials of electrically driven and spontaneously active isolated sheep cardiac Purkinje fibers were investigated using H1- and H2-selective agonists and antagonists. In electrically stimulated Purkinje fibers, histamine (3 mumol/l) increased the action potential plateau height, decreased the action potential duration measured at a repolarization level of -60 mV and enhanced the pacemaker activity. These effects were abolished by the H2-selective antagonist cimetidine (30 mumol/l), but were not impaired by the H1-selective antagonist dimetindene (0.3 mumol/l). In spontaneously active Purkinje fibers, histamine (10 mumol/l) increased the spontaneous rate by 24%, the slope of diastolic depolarization by 45% and shortened the duration of the diastole by 32% of the respective control measurements. These effects were blocked by 30 mumol/l cimetidine, but remained unchanged in the presence of 0.3 mumol/l dimetindene. Concentration-response curves of histamine were shifted to the right by approximately 2 logarithmic units in the presence of 30 mumol/l cimetidine, but were not influenced in the presence of 0.3 mumol/l dimetindene. The H2-selective agonist impromidine (0.001-0.3 mumol/l) had similar actions as histamine on spontaneously active Purkinje fibers, while the H1-selective agonist 2-(2-pyridyl-)ethylamine was ineffective. It is concluded that the pronounced stimulatory action of histamine on spontaneous activity in sheep cardiac Purkinje fibers is exclusively mediated by H2 receptors.

Action Potentials↗
PubMed1992

EGF receptor amplification and expression in human brain tumours.

Human epidermal growth factor receptor (EGFr) gene amplification, rearrangements and expression were studied in tumours of the human nervous system. EGFr gene amplification was studied in 46 brain tumours. Gene expression was analysed by northern blot in 37 tumours and binding of its protein to EGF in 27 tumours. The EGFr gene was simultaneously amplified (with arrangements in 12.5% of gliomas) and overexpressed in 53% (9/17) of malignant gliomas, but never in meningiomas. In five high grade gliomas, amplification was always associated with a high level of receptors. However, since high amounts of EGF receptors found in one glioma were not the result of gene amplification, several systems of deregulation in EGFr production may exist and could be located at translational and/or post-translational levels.

Adolescent↗
PubMed1992

Liver transplantation for erythropoietic protoporphyria. Report of a new case with subsequent medium-term follow-up.

We report a new case of successful liver transplantation in a 36-year-old patient with terminal hepatic failure due to erythropoietic protoporphyria. Data regarding protoporphyrin levels in erythrocytes and feces, before and after transplantation, seem to indicate that in this case protoporphyrin overproduction was in part due to liver synthesis. Four years after surgery, the patient is completely free of skin photosensitivity. His liver function tests are normal; there are no visible protoporphyrin deposits or ultrastructural abnormalities in his new liver. However, recurrence of the disease in the long term cannot be excluded, since erythrocyte protoporphyrin levels remained elevated after liver transplantation.

Adult↗
PubMed1992

t(2;18) and t(18;22) variant chromosomal translocations in B cell malignancies.

Variant translocations (2;18 and 18;22) are described in this review. The chromosomal and molecular findings of these translocation of BCL2 and their effect on possible BCL2 gene activation is discussed. Unanswered questions still remain and these include why this is so rare compared to the 25% incidence recorded for translocations in Burkitt's lymphoma. Further studies are obviously still needed in order to determine the true frequency of these findings and their distribution in the various B-cell disorders.

Animals↗
PubMed1992

[The EGF receptor pathway in human cerebral tumors].

The epidermal growth factor receptor gene is the most frequently involved proto-oncogene in human glial brain tumors, in the present series in agreement with previous reports in literature. It is therefore important to study this gene from DNA to the protein product. The vicinity of cystic fluid (C.F.) to tumor cells of the cystic wall has suggested investigation of possible "E.G.F.-like" autocrine activities in C.F. In 40% of gliomas, E.G.F.-R. gene is amplified and overexpressed. This is never observed in low grade astrocytomas. In 12% of the cases, mutations of the E.G.F.-R. gene are observed. In correlation with genomic abnormalities, E.G.F.-R. is immunoprecipitated in 40% gliomas. The basal phosphorylation of the receptor is increased in 50% gliomas. In C.F., unexpectedly, E.G.F.-R. phosphorylation inhibitory effect is observed. Its biochemical analysis suggests an anti-tyrosine kinase activity. The observation of anti-tyrosine kinase activity in C.Fs suggests the presence of negative modulatory factors of the proto-oncogene activation in tumor tissues. This could have therapeutical interest.

Blotting, Northern↗
PubMed1992

[Case report: anorexia nervosa in a 10-year-old boy].

A 10-year-old boy was admitted to the Children's Hospital with a 7-month history of disturbed eating behavior and a recent rapid weight loss: During the 24-day hospital stay the boy displayed a characteristic anorectic eating pattern, hyperactivity, anxiety, depression and compulsive behavior. Discharge followed a 4-kg weight gain. During the subsequent 12 months of outpatient care weight gain and eating behavior normalized. The boy's premorbid personality was described as compulsive and difficult. Although his intelligence was above average the boy had spelling problems and inadequate verbal skills. A change to a college-preparatory school and contact with a family with a vegetarian way of life probably precipitated the acute illness.

Anorexia Nervosa↗
PubMed1992

[Oncocytic presentation of a primary epithelioid leiomyosarcoma of the liver].

We report an epithelioid leiomyosarcoma of the liver with oncocytic differentiation. Initially misdiagnosed as an oncocytic endocrine tumor, analysis of the whole liver after transplantation permits rectification of the diagnosis. This observation outlines the fact that oncocytic differentiation is not restricted to epithelial cells but can also be encountered in cells of mesenchymal lineage.

Humans↗