Search PubMed⌕ Search

Biomedical subjects

W Wozniak

Publications and source records attributed to W Wozniak.

18 recordsLinked to original sources
PubMed1999

Polyhormonal aspect of the endocrine cells of the human fetal pancreas.

Histological studies were performed on 30 pancreases obtained from normal human fetuses aged between the 9th and 38th week. For immunocytochemistry, the avidin-biotin-peroxidase method was used to identify and colocalise insulin, glucagon, somatostatin, pancreatic polypeptide and proliferating cell nuclear antigen. In the 9th week, cells containing all investigated peptides were present. During the fetal period, two populations of endocrine cells have been distinguished, Langerhans islets and freely dispersed cells. The free cells were polyhormonal, containing insulin, glucagon, somatostatin and pancreatic polypeptide, and were localised in the walls of pancreatic ducts throughout the whole gland. During the development of the islets we have observed four stages: (1) the scattered polyhormonal cell stage (9th-10th week), (2) the immature polyhormonal islet stage (11th-15th week), (3) the insulin monohormonal core islet stage (16th-29th week), in which zonular and mantle islets are observed, and (4) the polymorphic islet stage (from the 30th week onwards), which is characterised by the presence of monohormonal cells expressing glucagon or somatostatin. Bigeminal and polar islets also appeared during this last stage. The islets consisted of an insulin core surrounded by a thick (in the part developing from the dorsal primordium) or thin rim (part of the pancreas concerned with the ventral primordium) of intermingled mono- or dihormonal glucagon-positive or somatostatin-positive cells. The most externally located polyhormonal cells exhibited a reaction for glucagon, somatostatin and pancreatic polypeptide. Apart from the above-mentioned types of islets, all arrangements observed in earlier stages were present. Proliferating cell nuclear antigen-positive cells (single in the large islets and more numerous in the smaller ones) were predominantly observed in the outermost layer. Taken together our data indicate that, during the human prenatal development of the islet, endocrine cells are able to synthesise several different hormones. Maturation of these cells involved or depended on a change from a polyhormonal to a monohormonal state and is concerned with decreasing proliferative capacity. This supports the concept of a common precursor stem cell for the hormone-producing cells of the fetal human pancreas.

Animals↗
PubMed1997

17 alpha-Hydroxylase and chromogranin A in 6th week human fetal adrenals.

The development of the human fetal adrenals starts in the 6th week gestational age and adrenal C19 steroid production becomes of major importance for the maintenance of the pregnancy. Therefore, in the present study, human fetal adrenals at 6 weeks of gestational age were immunostained for 17 alpha-hydroxylase, the key enzyme for the production of C19-steroids. In parallel, chromaffin cells were characterized by immunohistochemical staining for chromogranin A, the major soluble protein in adrenal chromaffin granules. Large 17 alpha-hydroxylase-immunoreactive cells were found in the center of the adrenal anlagen during the 6th week of gestation. At the same developmental stage, chromaffin cells with a neuronal-like appearance occurred in the paraortic area and started to invade the adrenal primordium. Our results show that, even at week 6 gestational age, when chromaffin cells start to enter the adrenal anlagen, human adrenals already contain differentiated, 17 alpha-hydroxylase immunoreactive cortical cells which were located to the center of the primordium.

Adrenal Glands↗
PubMed1996

Stereology of human fetal adrenal medulla.

Stereological studies were performed on 27 pairs of adrenal glands of human fetuses (9-38 weeks of intra-uterine development). Medullary chromaffin cells were identified by immunostaining for chromogranin-A. The volume of adrenal medulla, average cell volume, and the number of chromaffin cells were calculated. The volume of adrenal medulla increased slowly up to the 20th week and afterwards it enlarged rapidly to the 31 st week of the fetal period. A gradual, linear increase in the number of chromaffin cells of developing adrenal medulla was observed during the studied period. On the contrary, the average volume of the adrenal medullary cells remained quite constant until the 17th week of the development. Afterwards, a gradual, linear increase in the cell volume was observed until the 31 st week, reaching a plateau by the end of intra-uterine development.

Adrenal Medulla↗
PubMed1994

Relation of the vestibular ganglion to the otocyst and cochlear ganglion in human embryos during 5th and 6th week of development.

Human embryos during developmental stages 14-17 were investigated. At stage 14 the endolymphatic appendage is already developed. The vestibulocochlear and geniculate ganglia form common ganglionic complex surrounded by mesenchymal capsule. At this stage three components may be distinguished. The differentiation of the ganglia appears in the following sequence: geniculate, vestibular, cochlear. The geniculate ganglion is rostroventral and the vestibular dorsomedial in position.

Cochlea↗
PubMed1991

Urinary dopamine/noradrenaline and dopamine/vanillylmandelic acid ratios as a reflection of different biology of adrenergic clones in children's neuroblastic tumors.

The results of calculations of urinary dopamine/noradrenaline (DA/NAd) and dopamine/vanillylmandelic acid (DA/VMA) ratios in 54 untreated children with neuroblastic tumors are reported. Thirteen patients were in the prognostically favorable group (stages I, II, and IV-S and ganglioneuroma [GN]), and 41 had advanced neuroblastoma (stage III and IV). Among patients with ganglioneuroma and favorable neuroblastoma (n = 13), of whom all were survivors, the urinary DA/NAd and DA/VMA ratios exceeded 1.8 in only 2 cases of stage IV-S and stage I, respectively. In the advanced neuroblastoma group, the DA/NAd and DA/VMA ratios exhibited a wide range of values, but among the stage III and IV survivors (n = 10), DA/NAd ratios greater than 1.8 were noted in only 3 patients. The DA/VMA ratio was not greater than 1.8 in those 3 patients. The mean DA/NAd and DA/VMA proportions in the population comprising all survivors were 1.8 +/- 2.7 (mean +/- SD) and 1.1 +/- 0.4, respectively. The same computations carried out in patients who died showed higher values, ie, the mean DA/NAd and DA/VMA ratios were 5.2 +/- 6.3 and 5.6 +/- 10.5, respectively, showing the difference in DA/NAd and DA/VMA ratios between prognostically favorable and unfavorable groups. Of 23 survivors, only 4 had DA/NAd ratios greater than 1.8 (17%), while 24 of 31 children who died (77%) had DA/NAd ratios was greater than 1.8. The reported results suggest dissimilarity in the catecholamine metabolism of adrenergic clones with respect to the stage of advancement of neoplastic disease.

Abdominal Neoplasms↗
PubMed1982

[Role of chemotherapy in the treatment of Wilms' tumor in children].

In the years 1962-1976, 168 children with nephroblastoma (Wilms Tumour) were treated in the Clinical Department of Child Oncology of the Institute of Mother and Child in Warsaw. In 150 cases, independently from surgery and radiotherapy, chemotherapy was performed. Our material was divided into 5 groups: a) without chemotherapy, b) chemotherapy with different drugs, c) chemotherapy with 1 course of Actinomycine D, d) chemotherapy with several courses of Actinomycine D, e) chemotherapy according to SIOP Trial. The results with reccurency free survival are as follows: a) 22,2%, b) 24,1%, c) 28,1%, d) 46,6%, e) 56,6%. In our material the best results were received with SIOP Trial chemotherapy.

Adolescent↗
PubMed1980

The fine structure of the spinal cord in human embryos and early fetuses.

The developing human spinal cord was studied by electron microscopy in 7 embryos (18--28 mm (C.-R.) and 5 fetuses (35--45 mm). It was found that, during the last week of the embryonic period, the spinal cord undergoes distinct maturation, as evidenced by cytoplasmic organelles, glial differentiation, and the formation of synaptic junctions. The ventricular (ependymal) cells are ciliated; densely grouped cells with scanty processes occupy the early intermediate (mantle) zone; and glioblasts are present in the marginal zone. Degenerating cells are evident in the spinal cord. The first axondendritic synapses appear in the marginal layer of the basal plate in the cervical part of the spinal cord in a human embryo of 28 mm, i.e., during the embryonic period proper. In the fetal period, synapses are found also in the alar plate, and axosomatic synapses are present. The formation of synapses and the general maturation of the spinal cord seem to proceed craniocaudally. The appearance of synapses is in keeping with the finding of reflex movements in the human during the late embryonic and early fetal periods.

Ependyma↗
PubMed1976

An ultrastructural study of sympathetic ganglion satellite cells in the rat. 2. Effect of preganglionic sympathectomy.

The ultrastructure of satellite cells of the rat superior cervical ganglion was studied following preganglionic sympathectomy.Several distinct morphological alterations were observed: (a) enlargement of the intercellular space between the ganglion cells and the satellite cells, (b) dilation of the granular endoplasmic reticulum and loss of attached ribosomes, and (c) swelling of the mitochondria with disorganization of the cristae mitochondriales. The presence of degenerating nerve fibers and synaptic boutons was also noted.

Animals↗
PubMedDate not supplied

[Value of comparing flow cytometry examination and histopathology in prognosing of osteogenic sarcoma - preliminary report].

Our preliminary report presents two cases of osteogenic sarcoma examined after initial chemotherapy. In both cases histological maps with morphological effects of chemotherapy and flow cytometry of DNA content in tumour cells were made. Results of flow cytometric DNA histograms were linked with an estimation of the proliferative potential of tumours. The correlations between histological grade, proliferative potential of tumours with the morphological effects of chemotherapy were confirmed in the presented cases. Flow cytometry results were ready in a few hours after surgery, when full histopathological analysis was available in 2-4 weeks. Analysis of the two methods of estimation of osteogenic sarcoma suggests that flow cytometry may be a complementary method to histological examination and estimation of proliferating rate, especially aneuploid cell population and this information can be helpful in clinical management.

Adolescent↗
PubMedDate not supplied

[Comparative study of histopathological patterns of primary tumour and pulmonary metastases of malignant tumours in children and adolescents after complex therapy].

The histopathological features of the primary site and 102 pulmonal metastases were compared in the material from 40 malignancies in children and adolescents. All patients were treated by chemotherapy. Among the malignancies 30 were osteogenic sarcomas. A great histological variability in the multiple metastases removed at one surgical procedure and also in the metastases removed in the subsequent surgeries, were found. Summing up, the whole investigation; in 61.8% of metastatic focusses no difference was found in the histopathological patterns seen at the primary site and pulmonary metastases, in 17.6% total regression was observed, in 13.8% dedifferentiation and in 6.8% maturation of the tumours tissue were observed.

Adolescent↗
PubMedDate not supplied

[Evaluation of indications and the perspectives of limb salvage surgery in malignant bone tumours in children and youth].

Malignant bone tumours constitute about 7% of paediatric cancer. Within the last 20 years much has changed in cancer treatment. Neoadjuvant chemotherapy, the first phase of comprehensive treatment, results in regression of the tumour. This makes limb salvage surgery possible. At the National Research Institute of Mother and Child more than 250 patients with malignant bone tumours were treated. In this group there were 131 limb salvage operations. The analysis includes 117 patients with osteogenic sarcoma, 46 with Ewing sarcoma, 7 with chondro-sarcoma, treated between 1985 and 1995. Five years survival was achieved in 74.5% osteogenic sarcoma patients and 41.3% Ewing sarcoma patients.

Adolescent↗