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H Ostertag

Publications and source records attributed to H Ostertag.

At least 37 records · Page 2Linked to original sources
PubMed1997

Small cell carcinoma of the ovary, hypercalcemic type. A case report with immunohistochemical, ultrastructural and cytophotometric analysis and review of the literature.

Small cell carcinomas of the ovary, hypercalcemic type, are unilateral tumors occurring almost exclusively in young women. 60% of the cases are associated with hypercalcemia. Microscopic examination shows diffuse clusters of small cells and follicle-like spaces. Immunohistochemically, the tumor cells are positive for epithelial and mesenchymal markers, and ultrastructurally they contain an abundance of dilated rough endoplasmatic reticulum and numerous free ribosomes. By DNA-single cell photometry, the neoplastic cells show a diploid DNA-content.

Adult↗
PubMed1997

Performance evaluation of a whole-body PET scanner using the NEMA protocol. National Electrical Manufacturers Association.

UNLABELLED: This study evaluates the performance of the newly developed high-resolution whole-body PET scanner ECAT EXACT HR+. METHODS: The scanner consists of four rings of 72 bismuth germanate block detectors each, covering an axial field of view of 15.5 cm with a patient port of 56.2 cm. A single block detector is divided into an 8 x 8 matrix, giving a total of 32 rings with 576 detectors each. The dimensions of a single detector element are 4.39 x 4.05 x 30 mm3. The scanner is equipped with extendable tungsten septa for two-dimensional two-dimensional measurements, as well as with three 68Ge line sources for transmission scans and daily quality control. The spatial resolution, scatter fraction, count rate, sensitivity, uniformity and accuracy of the implemented correction algorithms were evaluated after the National Electrical Manufacturers Association protocol using the standard acquisition parameters. RESULTS: The transaxial resolution in the two-dimensional mode is 4.3 mm (4.4 mm) in the center and increases to 4.7 mm (4.8 mm) tangential and to 8.3 mm (8.0 mm) radial at a distance of r = 20 cm from the center. The axial slice width measured in the two-dimensional mode varies between 4.2 and 6.6 mm FWHM over the transaxial field of view. In the three-dimensional mode the average axial resolution varies between 4.1 mm FWHM in the center and 7.8 mm at r = 20 cm. The scatter fraction is 17.1% (32.5%) for a lower energy discriminator level of 350 keV. The maximum true event count rate of 263 (345) kcps was measured at an activity concentration of 142 (26.9) kBq/ml. The total system sensitivity for true events is 5.7 (27.7) cps/Bq/ml. From the uniformity measurements, we obtained a volume variance of 3.9% (5.0%) and a system variance of 1.6% (1.7%). The implemented three-dimensional scatter correction algorithm reveals very favorable properties, whereas the three-dimensional attenuation correction yields slightly inaccurate results in low- and high-density regions. CONCLUSION: The ECAT EXACT HR+ has an excellent, nearly isotropic spatial resolution, which is advantageous for brain and small animal studies. While the relatively low slice sensitivity may hamper the capability for performing fast dynamic two-dimensional studies, the scanner offers a sufficient sensitivity and count rate capacity for fully three-dimensional whole-body imaging.

Adenocarcinoma, Follicular↗
PubMed1996

Percutaneous bone biopsy, techniques and indications.

In the first part of this article we discuss some special technical aspects of percutaneous bone biopsy (PBB). But our main intention is to illuminate the critical indication of PBB against the background of the diagnostic and clinical utility. Reliable indications for PBB are: lytic metastases, solitary lytic lesions in a patient with known primary tumour and infection. Sclerotic metastases and vertebral compressions, on the other hand, have a lower diagnostic utility. Negative biopsies must be interpreted carefully and repeated if considered to be nonrepresentative The indication for percutaneous biopsy of primary bone tumours remains doubtful. Most of them require open biopsy.

Adult↗
PubMed1995

Proliferative activity of acoustic neurilemomas without neurofibromatosis determined by monoclonal antibody MIB 1.

Microscopic sections obtained from paraffin blocks of 30 consecutive neurilemomas stored in 1989 were investigated immunohistochemically with the new monoclonal antibody MIB 1 directed against recombinant parts of Ki-67 antigen. The immunohistochemical staining was carried out on dewaxed microwave-oven-processed paraffin sections of formalin-fixed tumour tissues. The labelling index (LI) obtained was below 1% in 21 cases, 1-3% in 7 cases and more than 3% in 2 cases. There was no correlation between the LI and the age of the patients or the tumour size. The major advantage of MIB 1 over previous immunohistochemical methods is its usefulness in long preserved sections which are ideal for retrospective studies.

Adult↗
PubMed1995

The comparison between the growth fraction of bilateral vestibular schwannomas in neurofibromatosis 2 (NF2) and unilateral vestibular schwannomas using the monoclonal antibody MIB 1.

Formalin-fixed paraffin sections of 55 consecutive bilateral vestibular schwannomas in 46 patients with neurofibromatosis 2 (NF2), and 50 patients with unilateral vestibular schwannomas were investigated immunohistochemically with the monoclonal antibody MIB 1 directed against recombinant parts of Ki-67 antigen. The immunohistochemical staining was carried out on dewaxed microwave oven-processed paraffin sections of formalin-fixed tumour tissues. The labelling index (LI) obtained was compared to clinical and histological findings in both groups. There was no correlation between the LI and age of the patients, tumour size, or histological type of tumour (Antoni A or B). Vestibular schwannomas in NF2 showed higher LI than unilateral vestibular schwannomas: the maximal LI found per section (LI max) ranged from 0.4 to 17.6% (mean, 2.7%) in NF2 schwannomas, and from 0 to 9% (mean, 2.2%) in unilateral schwannomas. These differences may express immunohistochemically some clinical and morphological differences between bilateral and unilateral vestibular schwannomas.

Adolescent↗
PubMed1995

[Extraneural metastasis of brain and spinal cord tumors. Report of 2 cases].

This case report refers to two patients with the rare entity of an extraneural metastasizing central nervous system tumor. The first patient presented with ipsilateral cervical lymph node metastases 4 years after a diagnostic biopsy and 2 years after removal of an anaplastic oligodendroglioma, respectively. The origin of the metastases was confirmed by immunohistochemistry. The second case described was found in a 26-year-old female who had suffered from a spinal cord pilocytic astrocytoma in infancy and been treated by surgery and radiotherapy. On postmortem examination, transformation to a primitive neuroectodermal tumor was found. Morphological and immunohistochemical features of the metastases were exactly identical with those of the primary tumors in both cases. The pathomechanisms of metastasizing CNS tumors are discussed with reference to the reasons why such cases are so rarely observed. The incidence of remote metastases and differences depending on tumor type are estimated. No relation to malignancy grade can be detected.

Adolescent↗
PubMed1995

[Oncocytoma of the nose. A case report and review of the literature].

Oncocytomas are rare epithelial tumors of the major and minor salivary glands. Reported is an oncocytoma of the lateral wall of the left nasal cavity in a 60-year-old man. Because of its locally invasive character, with rupture into the left nasal cavity and partial dedifferentiation with loss of typically oncocytic features, we classified the tumor as oncocytoma of low malignant potential.

Adenoma, Oxyphilic↗
PubMed1995

Neuromuscular choristoma.

Neuromuscular choristomas are rare, with only 13 cases having been previously reported. They usually arise in association with large nerves, and most often occur in the first decade of life. A few have been congenital. Although resection is typically curative, in two instances partial resection alone appears to have been followed by spontaneous regression. The authors report an unusual example of an otherwise classic neuromuscular choristoma where the lesion appeared to grow after incomplete initial resection. Re-excision disclosed a fibromatosis unassociated with choristoma. Despite its wide excision, a recurrence of the fibromatosis required a forequarter amputation. Theories of histogenesis and the clinicopathologic features of the neuromuscular choristomas reported to date are reviewed. The term "benign Triton tumor," although incorrectly applied to this lesion, should be reserved for benign, true nerve sheath neoplasms exhibiting myogenic differentiation.

Axilla↗
PubMed1995

Esthesioneuroblastomas with intracranial extension. Proliferative potential and management.

A total of 15 patients with esthesioneuroblastomas were treated between 1978 and 1992 at the Neurosurgery Department, Nordstadt Hospital, Hannover. In 9 cases, the tumors invaded the anterior cranial fossa. One patient died before any surgical intervention. Eight tumors were operated by a combined paranasal and subfrontal approach. Gross total tumor removal was achieved in all cases. Apart from anosmia, the only postoperative complication was transient mental changes in one case. Immunohistochemical analyses with MIB 1 monoclonal antibodies, directed against recombinant parts of Ki-67 antigen, were performed to estimate the proliferative potential of the esthesioneuroblastomas. Most of the tumors showed high proliferating cell indexes, which ranged from 3 to 42% (mean, 16%). The proliferating cell index with MIB 1 showed a correlation with postoperative outcome, although this was not statistically significant. Esthesioneuroblastomas can be totally removed surgically. The proliferating cell index may reflect histologically the biological behavior of tumor. Long-term follow-up is mandatory, and immunohistochemical studies may be of help in predicting outcome.

Adult↗
PubMed1995

Noninvasive assessment of hepatobiliary and renal elimination of cysteinyl leukotrienes by positron emission tomography.

N-Acetyl-leukotriene E4 has been identified as an endogenous, biologically less active cysteinyl leukotriene metabolite in rodents and humans. To evaluate the ratio of hepatobiliary to renal elimination of leukotrienes noninvasively by positron emission tomography (PET), we synthesized N-[11C]acetyl-leukotriene E4 by chemical N-acetylation of leukotriene E4. After the intravenous injection of N-[11C]acetyl-leukotriene E4 in normal rats and monkey, uptake by the liver and subsequent excretion into bile were largely responsible for its rapid elimination from blood. In the Cynomolgus monkey, renal excretion of the leukotriene into urine was of additional quantitative importance. Kinetic modeling indicated a mean transit time through the liver of 17 minutes and 34 minutes in rat and monkey, respectively; the corresponding hepatic excretion half-times amounted to 8.5 minutes and 16 minutes. In a mutant rat strain deficient in the hepatobiliary excretion of cysteinyl leukotrienes across the canalicular membrane, the apparent mean liver transit time was 54 minutes, and the hepatic excretion half-time was 29 minutes, indicating prolonged organ storage and metabolism. After transport from the liver back into the circulating blood of omega-oxidized and beta-oxidized metabolites of N-[11C]acetyl-leukotriene E4, renal excretion compensated for the impairment of hepatobiliary elimination in the transport mutant. Metabolite analyses in urine after intravenous injection of N-[3H]acetyl-leukotriene E4 indicated the extensive inactivation of N-acetyl-leukotriene E4 by beta-oxidation from the omega-end in the mutants. A similar shift from hepatobiliary to renal cysteinyl leukotriene elimination was monitored in rats with cholestasis due to bile duct obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Cranial granular-cell tumor of the trigeminal nerve. Case report.

Granular-cell tumors are exceedingly rare neoplasms in the central nervous system. Their histogenesis has been a subject of longstanding controversy but substantial findings support the current theory of a Schwann cell origin. Other recent histopathological studies point to an astrocytic origin in those tumors which arise from the cerebral hemispheres. A case of a granular-cell tumor arising from the trigeminal nerve is described. The origin, clinical course, radiological features, and treatment of such unusual intracerebral tumors are discussed.

Adult↗
PubMed1993

Immunohistochemical detection of female sex hormone receptors in meningiomas: correlation with clinical and histological features.

Sixty-one meningiomas from 60 patients were screened for estrogen receptors and progesterone receptors (PgR) with monoclonal antibodies in an immunohistochemical assay. In addition, 43 of the cases were evaluated for tumor size and peritumoral edema, as seen on computed tomographic scans and magnetic resonance images. Sixty-one percent of the tumors contained significant amounts of PgR, whereas no estrogen receptor-positive tumor was observed. Thirteen percent of all tumors were classified as nonbenign variants (atypical and anaplastic meningiomas) and were more frequently found in male patients (P < 0.05). Nonbenign tumors more frequently showed an absence of PgR (P < 0.05), and there was a tendency for PgR-negative tumors to be larger than PgR-positive ones. No correlation was found between PgR status and edema. It is concluded that PgR status in meningiomas is related to tumor differentiation and may be of prognostic value with regard to biological behavior and clinical outcome.

Adolescent↗
PubMed1993

Studies with positron emission tomography after systemic administration of fluorine-18-uracil in patients with liver metastases from colorectal carcinoma.

Fluorouracil (FU) is the most common cytostatic agent used for chemotherapy in patients with colorectal tumors. Fifty patients with 78 hepatic metastases from colorectal tumors were examined with positron emission tomography (PET) following intravenous infusion of 18F-FU. The uptake of the cytostatic agent was evaluated in normal liver parenchyma, liver metastases and the aorta. Tracer uptake was expressed with the standardized uptake value (SUV). The maximum liver activity was 11.3 SUV (mean value) with a standard deviation of 1.85 SUV. The highest activity concentrations were noted 30 min (mean value) postinjection. In comparison, the activity concentration of individual metastasis was low. Two hours after tracer injection, the mean activity in metastases was 1.3 SUV, but notable individual variation in uptake was seen. Fluorine-18 concentration values 2 hr after FU infusion were approximately 44% of the FU uptake 20 min postinfusion. Fifty-three metastases were also examined with 15O-labeled water. The examination was performed to compare the uptake of the nonmetabolized tracer with FU uptake. We noted a statistically significant correlation between 15O-water concentration, uptake of nonmetabolized FU 8 min after the end of the infusion and FU retention (120 min postinjection) in a subgroup of metastases. The results suggest that FU retention in different metastases is highly variable and mainly dependent on early FU uptake into tumor cells.

Colorectal Neoplasms↗
PubMed1993

[Percutaneous bone biopsy. Critical analysis of 153 patients].

The value of transcutaneous bone biopsy was critically examined in a retrospective study of 153 patients with various bone diseases. A comparison of the clinical, radiological and histological findings gave reliable results in approximately 82%. Specific results were worse in inflammatory processes than in those involving tumours. The results of biopsy were of particular interest where clinical and radiological examinations pointed to an isolated bone metastasis in cases of known and unknown primary tumours. The advantages of the method are discussed with regard to the patient's well-being and to cost.

Adolescent↗
PubMed1992

Primitive neuroectodermal tumors after prophylactic central nervous system irradiation in children. Association with an activated K-ras gene.

Three patients had supratentorial malignant brain tumors 7 to 9 years after prophylactic central nervous system (CNS) treatment for acute lymphocytic leukemia or malignant T-cell lymphoma. Therapy was administered at the age of 3 to 8 years and included cranial irradiation (total dose, 1800 to 2400 cGy) and intrathecal methotrexate. The brain tumors had histologic and immunohistochemical features of primitive neuroectodermal tumors (PNET), including neuroblastic rosettes, rhythmic arrangement of tumor cells, and immunohistochemical expression of glial, and in one patient neuronal, marker proteins. Using polymerase chain reaction-mediated DNA amplification from paraffin-embedded tissues and subsequent DNA sequence analysis, an activating point mutation was detected in the K-ras protooncogene in one tumor. This mutation was a G to A transition in position 2 of codon 12, substituting aspartate (GAT) for glycine (GGT). This type of mutation has not been observed before in human brain tumors, but it is frequent in radiation-induced murine lymphomas. These observations suggest that PNET can be induced after completion of the embryonal and fetal development of the human CNS. Oncogene-activating point mutations may represent a pathogenetic mechanism involved in the genesis of radiation-induced brain tumors.

Aspartic Acid↗
PubMed1992

Low incidence of bronchus-associated lymphoid tissue (BALT) in chronically inflamed human lungs.

The relevance of bronchus-associated lymphoid tissue (BALT) in man is still under discussion. Animal experiments indicate that the development of BALT is dependent on microbial stimulation. Therefore, the incidence of BALT was investigated retrospectively in specimens removed during surgical procedures on patients with chronic pulmonary inflammation. All these patients had severe chronic bronchitis and bronchiectasis, but BALT was found in only 8%. In patients with BALT and a malignant tumor, occlusion of a bronchus with poststenotic pneumonia was always present and BALT was observed exclusively in areas peripheral to the occlusion. In man other compartments of the lung must be responsible for the immune function of BALT found in animals.

Adolescent↗