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G W Hacker

Publications and source records attributed to G W Hacker.

At least 37 records · Page 2Linked to original sources
PubMed1995

Prognostic impact of DNA content and AUER classification in primary fallopian tube carcinoma.

DNA ploidy has been studied in 61 primary fallopian tube carcinomas using image-cytometry. The investigation also included survival analysis, and ploidy classification according to AUER was performed in order to evaluate its prognostic impact for fallopian tube carcinoma. A high number of aneuploid cases were observed (79% aneuploid vs. 21% euploid tumors). The high incidence of aneuploid tumors was consistently observed among all FIGO-stages as well as all groups of histologic grading. There was no correlation between ploidy and FIGO-stage or histologic grading. Patients with euploid DNA content showed a median survival of 34 months compared to 24 months for aneuploid cases (log-rank, P = 0.83). No correlation between the AUER classification and FIGO-stage or histologic grading could be observed. Tumors with an AUER type I and II (75th quantile 41 months) showed a better outcome than tumors with AUER III and IV (75th quantile 19 months). Although these results did not reach statistical significance (P = 0.07), a trend could be observed. Therefore AUER classification may be useful as an objective prognostic parameter. The high incidence of aneuploid tumors could be an expression of the high biologic aggressiveness of primary fallopian tube cancer which has been repeatedly mentioned in the past.

Adenocarcinoma↗
PubMed1995

Helospectin and pituitary adenylate cyclase activating polypeptide in the human vagina.

Helospectin and pituitary adenylate cyclase activating polypeptide (PACAP), both recently isolated from the poisonous saliva of the American lizard or from ovine hypothalamus respectively, belong to the same peptide family as vasoactive intestinal polypeptide (VIP), peptide histidine methionine (PHM) and glucagon. In the present study, occurrence and distribution patterns of nerve fibers containing helospectin- and PACAP-like immunoreactivity in the human vagina were investigated by immunohistochemistry. Double immunofluorescent labeling showed that helospectin or PACAP are co-expressed with VIP and PHM within subpopulations of VIP-immunoreactive nerve fibers. Nervous structures containing helospectin and VIP were particularly numerous in the internal mucous lining of the vagina and in free epithelial nerve endings, and an abundant network of nerve fibers surrounding blood vessels was detected. Nerve fibers co-expressing PACAP and VIP were more numerous than those expressing helospectin and VIP and were mainly found in close association with blood vessels as well as beneath and within the epithelium. Due to the lack of non-rabbit helospectin or PACAP antibodies, possible co-localizations between these two peptides could not be investigated at this time. The localizations demonstrated suggest possible roles of the two peptides in the regulation of local blood flow and lubrication of the vagina.

Adult↗
PubMed1995

Argyrophilic nucleolar organizer regions. A revised version of the Ag-NOR-staining technique.

Silver staining techniques developed to demonstrate argyrophilic nucleolar organizer regions (Ag-NORs) have been widely applied in a variety of cell kinetic studies, using the mean number of AgNORs in tumour cells as a marker for malignancy of certain types of neoplasms. However, the AgNOR techniques currently available are not entirely satisfactory, as unspecific silver precipitates readily form in the sections. On the other hand, the contrast staining may be so weak as to render identification of the AgNORs difficult. In the present study, some of the key factors influencing the outcome of AgNOR staining were evaluated in a more systematic way. A modified AgNOR staining procedure is now proposed, giving highly contrasting AgNORs with minimal unspecific silver precipitation, thus facilitating both manual and computerized counting. The new technique involves the use of microwave irradiation in order to shorten the processing time, the use of gelatin as a protective colloid, and a Farmer's solution to optimize the specificity of the technique.

Adrenal Cortex Neoplasms↗
PubMed1995

Regulatory peptides in the human soft palate.

The distributions of vasoactive intestinal polypeptide, peptide, histidine methionine, helospectin, neuropeptide Y and its C-flanking peptide, substance P and calcitonin gene-related peptide were studied in the human soft palate using immunocytochemical techniques. Peptide-containing nerve fibers were found to form a dense network around glandular acini, excretory ducts and blood vessels, as well as beneath and within the epithelium. Chromogranin A, bombesin-flanking peptide and calcitonin gene-related peptide immunoreactivities were detected in endocrine-like cells located in excretory ducts.

Calcitonin Gene-Related Peptide↗
PubMed1995

Proliferative activity in ectopic trophoblastic tissue.

Clinical observations have shown that tubal pregnancies develop individually different biological activities such as different growth rates, levels of beta human chorionic gonadotrophin (beta-HCG), or rates of tubal wall destruction. In the present study, we evaluated the proliferative activity of ectopic cytotrophoblastic tissue using immunocytochemistry with antibodies to Ki-67 (clone MIB-1). The rates of proliferation obtained were related to the maternal serum beta-HCG values. Reference data were obtained from placentas of intact intrauterine pregnancies (group I, n = 14). The proliferative activity of this tissue was compared to that of cytotrophoblastic tissue of tubal pregnancies (group II, n = 27). Ki-67-immunostained as well as non-stained cytotrophoblastic nuclei of the villi and the trophoblastic columns were counted separately, and results were expressed as percentage of positive cells. Serum beta-HCG values were determined twice, 48 h and immediately before operation. The cytotrophoblastic cells of intact intrauterine pregnancies (group I) showed uniform and high proliferative activities (80% on average in villi, 84% on average in columns). The average Ki-67 proliferation rate was significantly lower (P < 0.001) in trophoblastic tissue of tubal pregnancies (group II; 42% on average in villi, 61% on average in columns). Within the group of tubal pregnancies, higher intragroup differences were observed. The number of Ki-67-labelled cells was independent of the absolute preoperative serum beta-HCG values in both groups, yet they were clearly related to the relative increase of beta-HCG in maternal serum. At higher proliferation rates, there was a significant, growing increase of beta-HCG values (P < 0.01). We have found immunohistochemical evidence to support the previous clinical speculations that tubal pregnancies develop more heterogeneously and more slowly than intact intrauterine pregnancies. The development of the beta-HCG concentrations may be taken as an indirect parameter, reflecting proliferative activity of the trophoblast.

Cell Division↗
PubMed1994

DNA ploidy in primary fallopian-tube carcinoma using image cytometry.

Determination of DNA ploidy in 61 samples of primary Fallopian-tube carcinoma (FTC) by use of image cytometry is presented. Of these samples, 48 showed an aneuploid DNA content. Patients with euploid DNA content showed a median survival time of 33.8 months compared to 24.5 months for aneuploid cases. A high incidence of aneuploid tumors was consistently observed among all FIGO stages and in all groups of histologic grading. However, no correlation between ploidy and FIGO stage or histologic grading could be demonstrated. This observation could be regarded as a marker for the high aggressiveness of FTC which has been repeatedly described in the past.

Adult↗
PubMed1994

Stereologic parameters of nuclear ultrastructure as markers of the steroid receptor status in breast cancer epithelium.

The nuclear specific surface density (Sv/Vv), mean nuclear area (A) and numerical density (Nv) of tumor cell nuclei from 30 primary invasive female breast carcinomas with known concentrations of estrogen and progesterone receptors (ER and PR), were morphometrically analyzed at the ultrastructural level. It was found that carcinomas with concordant positive ER and PR status contained significantly higher number of smaller nuclei per volume unit of epithelium (mean Nv = 1.5 x 10(6) mm-3, mean A = 27 microns 2), than carcinomas of negative concordant receptor status (mean Nv = 0.8 x 10(6) mm-3, mean = 37 microns 2). Tumor cell nuclei of the former frequently displayed an elliptic shape (mean Sv/Vv = 1.16 microns-1), and had deeply invaginated surfaces, whereas nuclei of the latter were more frequently ball-shaped and exhibited a smooth-surface (mean Sv/Vv = 0.88 microns-1). The numerical density Nv (NUC/EPI) of tumor cell nuclei turned out to be a most reliable morphological marker of the concordant ER and PR status (overall efficiency = 84%, p < 0.01). The nuclear surface and volume ratio and mean nuclear area also appear to be reliable markers for terminal stages of the biochemical differentiation of breast carcinoma (overall efficiency = 79%, p < 0.05).

Adult↗
PubMed1994

Individual differences between nuclear parameters of normal and malignant breast epithelium.

This study attempts to estimate the status of estrogen and progesterone receptors (ER and PR) in tissue of invasive breast carcinoma. Identical stereologic parameters of nuclear ultrastructure, of normal and malignant epithelium in the same breast were compared. Samples of normal and malignant epithelium of 30 surgically amputated breasts were analysed morphometrically. The concentration of ER and PR in the malignant epithelium was estimated by means of the dextran-coated charcoal (DCC) method. We measured the mean nuclear area (A), nuclear specific density (Sv/Vv) and nuclear numerical density (Nv) of epithelium. The comparison of such models of normal and malignant epithelium nuclear ultrastructure of the same breast demonstrated: a) the difference between Sv/Vv of nuclei very sensitively and specifically marks the ER status in malignant tissue (overall efficiency = 80%, p < 0.01), and b) the difference between A, Sv/Vv and Nv marks the concordant ER and PR status with identical overall efficiency. Minimal individual differences in size, surface structure and shape, observed between nuclei of malignant epithelium of positive concordant ER and PR status and nuclei of normal epithelium demonstrated that the highest morphological similarity is associated with biochemical similarity of cells exposed to the identical media of steroid hormones.

Adult↗
PubMed1994

[Autonomic and peptidergic innervation of the human larynx].

Autonomic and peptidergic innervation of the human larynx (vocal cords, ventricular folds, epiglottis, subglottic region and recurrent nerves) was studied by application of single and double immunocytochemistry and radioimmunoassay. In all tissues investigated, immunoreactivities for a variety of regulatory peptides were detected and included vasoactive intestinal polypeptide (VIP), peptide histidine methionine (PHM), helospectin, neuropeptide Y (NPY), C-flanking peptide of NPY (C-PON), calcitonin gene-related peptide (CGRP), substance P and neurokinin A. In the recurrent nerves, only a few peptide-immunoreactive nerve fibers were found. The laryngeal region of the epiglottis and the subglottic region showed characteristic corpuscular nerves containing substance P and CGRP running underneath and within the epithelium.

Adult↗
PubMed1993

Autonomic and peptidergic innervation of human nasal mucosa.

The localization and distribution of vasoactive intestinal polypeptide (VIP), peptide histidine methionine (PHM), the novel peptide helospectin, neuropeptide tyrosine (NPY) and its C-flanking peptide (C-PON), substance P and calcitonin gene-related peptide (CGRP) were studied in the middle and inferior turbinate of the human nose using sensitive immunocytochemical and radioimmunological methods. For light microscopy, double immunofluorescence and immunogold-silver staining methods were applied. Ultrastructural immunoelectronmicroscopy was performed using a pre-embedding method. In addition, semithin Epon resin sections were immunostained. The concentrations of VIP, NPY, CGRP, substance P and neurokinin A were measured using radioimmunological methods. A dense network of autonomic and peptidergic nerve fibers in the normal human nasal mucosa was demonstrated. Colocalization studies showed the coexistence of peptides with components of the autonomic nervous system. Scattered chromogranin A-, CGRP and bombesin-flanking peptide (BFP)-immunoreactive endocrine-like cells were detected within the lamina propria and in groups within exocrine ducts. Highest radioimmunoassay (RIA) tissue concentrations were detected for VIP, followed by NPY, substance P, CGRP and neurokinin A.

Autonomic Nervous System↗
PubMed1993

Regulatory peptides in the human larynx and recurrent nerves.

We studied the peptide-innervation of the human larynx (vocal cord, ventricular folds, epiglottis, subglottic region and the recurrent nerves) using immunocytochemical and radioimmunological methods. In the tissues of the larynx investigated, the following regulatory peptides were detected: vasoactive intestinal polypeptide (VIP), peptide histidine methionine (PHM), helospectin, neuropeptide Y (NPY), C-flanking peptide of NPY (C-PON), calcitonin gene-related peptide (CGRP), substance P and neurokinin. In the recurrent nerves only small numbers of peptide-immunoreactive nerve fibers were found. Most of them showed positive immunoreactivities with antibodies to PHM, NPY and C-PON, but only rare and scattered nerve fibers were positive for VIP-, CGRP- and substance P.

Fluorescent Antibody Technique↗
PubMed1993

Application of silver acetate autometallography and gold-silver staining methods for in situ DNA hybridization.

In situ hybridization using biotinylated DNA probes has become an important tool in histopathology. It is well known that the sensitivity of the methods used to demonstrate viral DNA in formalin-fixed and paraffin-embedded specimen depends strongly on the detection system used. In the present study, an optimized in situ DNA hybridization protocol was combined with four different approaches of gold-silver staining methods. For silver enhancement, the recently described method of silver acetate autometallography, a technique allowing highly efficient development without the necessity of dark room illumination has been used. The most efficient detection method found in our experiments was the use of gold-adsorbed anti-biotin antibodies with subsequent silver enhancement. This staining procedure can be completed in 5 hours including hybridization and is a highly sensitive alternative to peroxidase and alkaline phosphatase detection systems.

Cytomegalovirus↗
PubMed1992

Distribution and co-localization of immunoreactive helospectin with vasoactive intestinal polypeptide and peptide histidine methionine in human nasal mucosa, soft palate and larynx.

Regulatory peptide immunoreactivities reported in the upper respiratory system of man include vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM), which are co-localized in a network of fine varicose nerve fibers. The present study was undertaken to examine the possible occurrence and distribution of the recently described VIP-like peptide helospectin. Double immunofluorescence labelling showed that helospectin is co-localized with VIP and PHM. In addition to nerve fibers containing all three peptides, scattered nerve fibers were detected that were only immunoreactive to helospectin but not to VIP and/or PHM. The distribution of helospectin/VIP/PHM immunoreactive nerve fibers around blood vessels and in close relationship to seromucous glands indicates their possible involvement in the regulation of blood flow and secretion.

Fluorescent Antibody Technique↗
PubMed1992

Neuropeptides in human salivary (submandibular and parotid) glands.

The existence, distribution and density of various neuropeptides in human submandibular and parotid glands were investigated using immunocytochemistry and radioimmunoassay. Numerous nerve fibers containing vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM), or neuropeptide Y (NPY) and C-flanking peptide of NPY (CPON) immunoreactivities (ir) were found in close association to acini, ducts and blood vessels. Only few calcitonin gene-related peptide (CGRP)- and substance P (SP)-ir nerve fibers could be demonstrated, mainly localized around blood vessels and ducts. Galanin and the newly discovered peptides helospectin and pituitary adenylate cyclase activating peptide (PACAP) could not be detected in human salivary glands.

Fluorescent Antibody Technique↗
PubMed1992

[Peptidergic innervation of human salivary glands (parotid gland and submandibular gland)].

Immunocytochemistry and a radioimmunoassay were used to investigate the existence and distributions of various regulatory peptide immunoreactivities (ir) in human submandibular and parotid glands. Numerous nerve fibers containing vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM), or neuropeptide tyrosine (NPY) and C-flanking peptide of NPY (CPON)-ir were found in close proximity to acini, ducts and blood vessels. Only a few calcitonin gene-related peptide (CGRP)- and substance P (SP)-ir nerve fibers could be demonstrated and were mainly localized around blood vessels and ducts. Galanin and the recently discovered peptides helospectin and pituitary adenylate cyclase activating peptide were unable to be detected in the salivary glands studied. Preliminary quantitative investigations of four human submandibular glands using radioimmunoassay showed that VIP-ir had the highest concentration, followed by NPY-ir and CGRP-ir; SP-concentrations were below the detection limit. The possible physiological significance of these peptides for salivary secretion is discussed.

Adenoma, Pleomorphic↗
PubMed1991

Paragangliomas: neuroendocrine features and cytometric DNA distribution patterns. A clinico-pathological study of 22 cases.

Paragangliomas from 22 patients with extraadrenal tumours of this type were studied. Neuroendocrine features were examined using immunohistochemical techniques. Twenty-two antisera raised against neuroendocrine "markers", regulatory peptides, serotonin and intermediate filament proteins were studied in this group and cytometric DNA assessments were made by means of image cytometry. One normal and 5 hyperplastic carotid bodies were used as controls in the DNA cytometric investigations. Clinical and/or histopathological evidence of "malignancy" was present in 5 cases. The tumour cells showed heterogeneity with regard to their expression of different peptides, and the immunohistochemical analyses did not permit differentiation between benign and malignant paragangliomas. An euploid nuclear DNA distribution pattern was found in all controls and in 17 of the tumours; all except 1 were clinico-pathologically benign. An aneuploid DNA pattern was observed in 5 of the cases and some malignant features were present in 4 of these cases. DNA data may give further information apart from that obtained from the histopathological findings which may be of value in predicting the biological behaviour of this tumour type.

Adult↗