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E Horvath

Publications and source records attributed to E Horvath.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Primary epiploic appendicitis: clinical and radiological diagnosis].

BACKGROUND: Torsion of appendices epiplocae leads to an ischemic infarct of surrounding adipose tissue, causing a syndrome, called "primary epiploic appendagitis" characterized by acute abdominal pain that can simulate a surgical clinical picture. AIM: To describe the clinical picture, ultrasonographic and computed tomographic features of primary epiploic appendagitis. MATERIAL AND METHODS: A report of patients with acute abdominal pain whose diagnosis was a primary epiploic appendagitis, diagnosed and treated in a period of 48 months. RESULTS: Fifty five patients (45 males) aged 16 to 76 years old are reported. Their clinical presentation was acute abdominal pain in the left abdominal quadrant in 48, pain in the right lower quadrant in 4 and epigastric pain in two. Two had mild fever and 12 had nausea. Ten perform physical activities prior to the onset of pain. Imaging examinations showed a 1.5 to 5 cm diameter, uncompressible small mass of adipose origin, located anteriorly and anterolaterally, between the colon and the abdominal wall. There were inflammatory phenomena surrounding the lesion and thickening of the neighboring parietal peritoneum. In all cases, the mass gradually subsided with medical treatment. CONCLUSIONS: Primary epiploic appendagitis is a relatively frequent cause of spontaneously resolving abdominal pain. It is diagnosed by ultrasound or CT scanning.

Abdomen, Acute↗
PubMed1999

Persistence of lymphocytic choriomeningitis virus at very low levels in immune mice.

Lymphocytic choriomeningitis virus (LCMV), strain WE, is a non-cytopathic RNA virus that is highly adapted to its natural host, the mouse. Acute infection of adult mice leads to generalized virus spread, followed by cytotoxic T lymphocyte-mediated virus clearance below the detection levels of conventional assays within 2-3 weeks. Indirect evidence had suggested that virus or viral antigen might persist in the immune mouse. Here we demonstrate LCMV-WE persistence at low levels after infection with 10(2) or 10(6) plaque-forming units, shown as viral genome, viral antigen, and replicative virus using sensitive in vitro and in vivo assays. The finding that LCMV-WE persists in the face of apparently intact immune responses resembles the situation in some viral (hepatitis B and C, HIV) and bacterial (tuberculosis, leprosy) infections in humans; the results are relevant to the understanding not only of other murine and human persistent viral infections but also of protective immunological memory by "infection immunity."

Animals↗
PubMed1999

Modification of the Kaolinite Hydroxyl Surfaces through the Application of Pressure and Temperature, Part III.

Kaolinite hydroxyl surfaces have been modified by the combined application of heat and pressure in the presence of water at 120 degrees C and 2 bars and at 220 degrees C and 20 bars. X-ray diffraction shows that some of the layers are expanded. It is hypothesized that this expansion occurs at the edges of the crystals due to the intercalation of water. The X-ray diffraction data is supported by diffuse reflectance infrared spectroscopy, with additional hydroxyl stretching bands observed around 3550 and 3590 cm-1. These bands are attributed to adsorbed water and to edge-intercalated water. Additional bands are observed in the hydroxyl deformation region around 895 and 877 cm-1. The position of these bands depends on the defect structure of the kaolinite and the conditions under which the kaolinite was thermally treated. Additional water bending vibrations were observed at 1651 and 1623 cm-1 for the thermally treated high-defect kaolinite and at 1682 and 1610 cm-1 for the low-defect kaolinite. The bands at 1651 and 1682 cm-1 are attributed to the bending modes of water coordinated to the kaolinite surface. The role of water in the edge intercalation of water in the high- and low-defect kaolinites is apparently different. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Modification of Kaolinite Surfaces through Intercalation with Potassium Acetate, II.

The modification of kaolinite hydroxyl surfaces of both ordered and disordered kaolinites has been studied under a range of conditions and intercalating agents. This has been achieved by the study of the kaolinite hydroxyl deformation vibrations by the application of diffuse reflectance Fourier transform infrared (DRIFT) spectroscopy. Kaolinites showed resolved bands at 940 and 915 cm-1 with an additional band at 923 cm-1. The bands at 940 and 923 cm-1 are assigned to the hydroxyl deformation modes of the inner surface hydroxyl groups, and the 915 cm-1 band is assigned to that of the inner hydroxyl group. When the kaolinite is intercalated with potassium acetate additional bands were found at 909 and 897 cm-1 for the ordered kaolinites. An additional band at 877 cm-1 is observed for the disordered kaolinite and is attributed to the hydroxyl deformation mode of non-hydrogen-bonded hydroxyl groups. The bands at 909 and 897 cm-1 range are attributed to inner surface hydroxyl groups hydrogen bonded to water or acetate groups. The intensity of these bands reflects the degree of disorder introduced into the kaolinite through intercalation. The intensities of the kaolinite hydroxyl deformation modes are a function of the starting kaolinite order and the method of preparation. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Apoptosis in nontumorous and neoplastic human pituitaries: expression of the Bcl-2 family of proteins.

Analyses of apoptosis and of the apoptosis regulatory proteins Bcl-2, Bax, Bcl-X, and Bad were done in 95 nontumorous and neoplastic pituitary tissues by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL), immunohistochemistry, and Western blotting. The apoptotic index was relatively low in all groups but was at least fourfold higher in pituitary carcinomas compared with any other groups. Pituitaries from pregnant and postpartum women had a fivefold higher apoptotic index compared with matched controls from nonpregnant females. Preoperative treatment of adenomas with octreotide or dopamine agonists did not change the apoptotic index significantly. The lowest levels of Bcl-2, Bax, and Bcl-X expression were in pituitary carcinomas as detected by immunostaining. An immortalized human pituitary adenoma cell line, HP75, developed in our laboratory using a replication-defective recombinant human adenovirus with an early large T-antigen, had a much higher level of apoptosis than nontumorous and neoplastic pituitaries. Treatment with transforming growth factor (TGF)-beta1 and protein kinase C (PKC) inhibitors increased apoptosis in this cell line. Analysis of the Bcl-2 family of proteins after treatment with TGF-beta1 and PKC inhibitors showed a 20% to 30% decrease in Bcl-X in the treated groups compared with controls. These results, which represent the first study of apoptosis in pituitaries from pregnant and postpartum cases and in pituitary carcinomas, indicate that 1) the apoptotic rate is low in nontumorous and neoplastic pituitary tissues but is relatively higher in pituitary carcinomas, 2) there are alterations in the expression of the Bcl-2 family of proteins in pituitary neoplasms with a decrease in Bcl-2 expression in pituitary carcinomas that may contribute to pituitary tumor pathogenesis and/or proliferation, and 3) cultured pituitary tumor cells respond to TGF-beta1 and PKC inhibitors by undergoing apoptotic cell death.

Adult↗
PubMed1999

The Src-family kinase Lck can induce STAT3 phosphorylation and DNA binding activity.

Constitutive activation of the Src-family kinase Lck has been shown to lead to transformation. Constitutive activation of the STAT pathway of transcription factors has also been shown to be involved in transformation. An oncogenic form of the prototypical member of the Src-family, v-Src, has been shown to activate STAT3, and this activation is required for v-Src's transforming ability. To investigate whether Lck could directly activate STAT3, a baculovirus expression system was utilised. When Lck and STAT3 were coexpressed, STAT3 was found to have enhanced tyrosine phosphorylation and DNA binding activity. This finding was confirmed with experiments where exogenous Lck was added to baculovirus produced STAT3. Moreover, the activation of STAT3 by exogenous Lck could be attenuated by the Lck-specific inhibitor PP1. In addition, mammalian cells stably expressing a constitutively activated form of Lck were shown to have activated STAT3. These data provide strong evidence that, like v-Src, Lck can also directly activate STAT3, which contributes to the transformation process.

Animals↗
PubMed1999

Polypharmacy in psychiatric treatment. Patterns of psychotropic drug use in Austrian psychiatric clinics.

There are great variations in the way psychotropic drugs are prescribed. Most experts are in favour of psychopharmacological monotherapy, but little is known about the extent to which it is actually practised. A survey of the psychopharmacological medication of all patients under treatment was carried out in three Austrian psychiatric clinics of various types on two separate days. A psychiatric university clinic, the psychiatric department of a general hospital and a regional mental hospital were selected for the survey. It was established that only 8% to 22% of the patients underwent psycho-pharmacological monotherapy and that the patients received 2.2 to 3.3 psychotropics on average. Five to 22% of the patients received five or more psychotropic agents. The results are presented in more detail in relation to the diagnoses of schizophrenia and depression. The rare occurence of monotherapy might be due to unsound treatment regimens in some instances, but much more to a general trend in psychiatry fostering polydrug use.

Adult↗
PubMed1999

Prolactin-producing pituitary adenoma and carcinoma with neuronal components--a metaplastic lesion.

Recent studies indicate that cells of various epithelial tumors are capable of transformation to neurons. Observing both neurons and neuropil in two prolactin-producing adenohypophyseal tumors, one benign and one malignant, we sought to assess their cellular differentiation, the presence of nerve growth factor receptor, and expression of the dopamine receptor gene using immunocytochemistry, electron microscopy, and in situ hybridization. Light and electron microscopy clearly revealed cells morphologically transitional between adenoma/carcinoma cells and neurons. Large neurons lacked proliferative activity. Neurons in varying number showed immunoreactivity for pituitary hormones including prolactin, growth hormone and alpha subunit in the adenoma and prolactin alone in the carcinoma. The distribution of nerve growth factor receptor staining was similar. In both tumors, in situ hybridization showed mRNAs for prolactin and dopamine receptor within adenohypophyseal cells and neurons. Our results indicate that the occurrence of neurons and neuropil in growth hormone and prolactin-producing pituitary tumors appears to be the result of metaplasia. The process is not limited to benign tumors and may be due to the production of tropic substances by the adenohypophysial cells, which by paracrine/autocrine mechanisms result in transformation of adenoma cells to nerve cells.

Adenoma↗
PubMed1999

Pituitary hyperplasia.

Comprehensive article summarizing more than 25 years of experience with pituitary hyperplasia in surgical material. Morphologic forms of hyperplasia--diffuse and nodular--are defined and, for comparison, the normal morphology, frequency and intraglandular distribution of cell types are briefly reviewed. All cell types can give rise to hyperplasia, although their frequency, extent and clinical importance widely vary. Somatotroph hyperplasia is rare; it is limited to cases of GHRH overproduction by extrapituitary endocrine neoplasms and sporadic examples of gigantism. Prolactin cells display the highest propensity for non-neoplastic proliferation. Physiologic hyperplasia occurs in pregnancy and lactation. Pathological hyperplasia is mostly secondary to other, neoplastic or non-neoplastic, space occupying processes. Idiopathic lactotroph hyperplasia is very rare. The much-disputed corticotroph hyperplasia is infrequent cause of pituitary dependent Cushing's disease. Despite difficulties of diagnosis in fragmented biopsies, several well-documented cases prove the existence of corticotroph hyperplasia which is nearly always nodular. Thyrotroph hyperplasia, secondary to hypothyroidism, a treatable condition, is not expected to occur in surgical material, yet several cases have been identified. Operated lesions are massive nodular leading to significant pituitary enlargement thereby mimicking TSH- or PRL-producing adenoma. Hyperprolactinemia is a frequent concomitant of severe thyrotroph hyperplasia. Gonadotroph hyperplasia and proliferation of pars intermedia derived POMC cells are not likely to occur in surgical material and have no clinical significance. Adenoma formation may rarely be associated with any type of pituitary hyperplasia.

Adrenocorticotropic Hormone↗
PubMed1999

A functioning composite 'corticotroph' pituitary adenoma with interspersed adrenocortical cells.

We report the third case of a composite corticotroph pituitary adenoma with interspersed adrenocortical cells. The 16-year-old male patient presented with findings of delayed growth and pubertal arrest. In contrast to the previous two cases, this patient's tumor showed evidence of function as demonstrated by an elevated urinary cortisol level. Imaging studies revealed a sellar mass that was excised transsphenoidally. Histologic examination revealed a composite tumor composed of distinct populations of large and small cells. The small cell population was PAS-positive and immunohistochemically positive for adrenocorticotrophic hormone. The large cell population had abundant vacuolated cytoplasm, was negative for PAS and adrenocorticotrophic hormone, and stained positively for a panel of markers found in steroid-producing adrenocortical cells. Both populations showed evidence of proliferation as manifest by the presence of MIB-1 positive cells. Ultrastructural examination confirmed the presence of distinct populations of large adrenocortical cells and small corticotrophs, with intercellular junctions between the 2 cell types. The intimate relationship between the 2 cell populations and the activated appearance of the adrenocortical cells suggests the possibility of a paracrine relationship between the two cell types. The identification of 3 patients with sellar tumors demonstrating strikingly similar morphological and ultrastructural features, and all occurring in the second decade of life, suggests that this represents a distinct pathologic entity.

Adenoma↗
PubMed1999

Cytology of pituitary thyrotroph hyperplasia in protracted primary hypothyroidism.

Pituitary thyrotroph hyperplasia, a rare cause of pituitary enlargement, is usually associated with protracted primary hypothyroidism. We present here a case of pituitary thyrotroph hyperplasia in a 51 year old woman who was thought to have a pituitary macroadenoma with suprasellar extension. The cytologic investigation of the intraoperative touch preparation identified hyperplastic thyrotrophs, provided the correct diagnosis and helped to limit further aggressive surgical removal of the lesion, which is known to regress after adequate thyroid hormone replacement therapy. This is the first study to describe the cytologic features of pituitary thyrotroph hyperplasia confirmed subsequently by histology, immunocytochemistry and transmission electron microscopy.

Adenoma↗
PubMed1999

Cancer vaccines with emphasis on a viral oncolysate melanoma vaccine.

Biotherapy of malignant diseases has become the fourth treatment modality besides surgery, chemo- and radiotherapy. Whole cell melanoma vaccines with or without BCG and other adjuvants, purified ganglioside and shed antigens, recombinant viruses carrying tumor antigens, dendritic cells pulsed with antigenic peptides etc. are in clinical trials. Efficacious viral oncolysate vaccines induce the host to mount tumor-specific cytotoxic T-cell response and prevention of relapses is supported by clinical trials. The use of "polyvalent" whole cell vaccines vs. purified or genetically engineered single antigen vaccines is justified as i. only very few single tumor antigens are present in all tumors of a given histological type; and ii. antigen modulation occurs in tumors rendering them resistant to immune attack generated by vaccine against a single antigen. Thus polyvalent vaccines immunize against several antigens vs. against a selected antigen.

Adjuvants, Immunologic↗
PubMed1999

Intrasellar paraganglioma presenting as nonfunctioning pituitary adenoma.

Paragangliomas arising in the sellar region are rare. We report a case of intrasellar paraganglioma of a 54-year-old man who presented with gradually decreasing visual acuity. Physical examination revealed bitemporal hemianopsia with no apparent signs of endocrinologic dysfunction. Magnetic resonance imaging revealed a large sellar mass believed to be a nonfunctioning pituitary adenoma. The tumor was removed transsphenoidally and submitted for histologic examination. The morphologic features, based on histologic, immunocytochemical, and electron microscopic analyses, were consistent with the diagnosis of paraganglioma. The diagnostic morphologic features and the immunocytochemical profile of the tumor are reported.

Adenoma↗
PubMed1999

Prenatal sonographic diagnosis of Aarskog syndrome.

In 1970, Aarskog described a rare X-linked developmental disorder characterized by short stature in association with a variety of structural anomalies involving mainly the face, distal extremities, and external genitalia (faciodigitogenital syndrome). The major facial manifestations of this syndrome include hypertelorism, broad forehead, broad nasal bridge, short nose with anteverted nostrils, long philtrum, widow's peak hair anomaly, and ocular and ear anomalies. Limb abnormalities consist of short broad hands, brachydactyly, interdigital webbing, hypoplasia of the middle phalanges, proximal interphalangeal joint laxity with concomitant flexion and restriction of movement of distal interphalangeal joints, and flat broad feet with bulbous toes. Genital anomalies are characteristics and include shawl scrotum, cryptorchidism, and inguinal hernia. Most affected patients have normal intelligence, but some authors have noted mild neurodevelopmental delay in up to 30% of the cases. We describe a case of Aarskog syndrome diagnosed prenatally by sonography at 28 weeks' gestation in a high-risk pregnancy for this disorder.

Abnormalities, Multiple↗
PubMed1998

Electrophoretic methods for process monitoring and the quality assessment of recombinant glycoproteins.

In many ways electrophoretic techniques appear ideal for quality monitoring of proteins and are thus well suited for the analysis of recombinant glycoproteins. The requirements of high throughput, comparative analysis and resolution of many variants are met by several electrophoretic techniques. A wide variety of such techniques are available to biotechnologists in the rapidly developing area of recombinant glycoproteins. It is the aim of this review to specifically cover recent work which has been applied to the analysis of DNA-derived glycoproteins, both from a process control standpoint and final product validation. All major areas of electrophoresis including sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing and techniques utilizing capillary electrophoresis are covered, with emphasis on analysis of glycoforms and oligosaccharide profiles of recombinant glycoproteins. As illustration, actual examples rather than standard glycoproteins are given to indicate the potential and limitations which may be encountered. It is anticipated that this review will prove a useful and practical guide to the latest developments by indicating the relevant merits of different methods.

Animals↗
PubMed1998

Cytokine gene activity in AML cells in vivo in patients.

The proliferation of acute myelogenous leukemia cells is dependent upon cytokine stimulation. Additionally, there is a body of literature which reports that leukemia cells produce GMCSF, IL6, and other cytokines. The study reported here, using an rt-multiplex polymerase method, determined the presence or absence of transcripts in freshly obtained AML cells for the following cytokine or cytokine-related genes: IL 1beta, IL1ra, TNF alpha, GMCSF, IL6, flt 3, and hSCF. This demonstrated that leukemia cell populations usually contain transcripts for IL1beta, TNF alpha, flt 3 and flt 3 ligand in vivo and that transcripts for the other cytokines only appear after the leukemia cells are processed in vitro. The presence of TNF alpha transcripts appears to be associated with resistance to remission induction therapy. Furthermore, the transcript profile of the leukemia cells can change during remission induction therapy. The data also demonstrate the assessment of cytokine production by leukemia cells after in vitro manipulation should not be extrapolated to the in vivo situation.

Adult↗