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Biomedical subjects

K Sames

Publications and source records attributed to K Sames.

At least 19 recordsLinked to original sources
PubMed2001

Lectin and proteoglycan histochemistry of Merkel cell carcinomas.

Changes in carbohydrate residue expression and in proteoglycan distribution occur during different stages of tumor development and progression. However, few data concerning carbohydrate residue analysis as performed by lectin histochemistry and proteoglycan distribution of Merkel cell carcinoma, a rare malignant tumor of the skin, have been reported. Hence, lectin- and proteoglycan immunohistochemistry was performed on paraffin wax material of 9 cases of Merkel cell carcinomas characterized by cytokeratin and neurofilament immunohistochemistry. The lectin binding pattern of tumor cells varied between lectins with different sugar binding specificities, while within a given nominal sugar specificity intensities were remarkably similar between tumors from different patients. The most intensive reaction was observed using Con A (mannose/glucose-specific) followed by LCA with the same specificity and the N-Acetyl glucosamine-specific lectins (WGA, UDA, CMA), while no fucose binding sites were detected (UEA-I). In addition, N-Acetyl galactosamine residues were only occasionally detected. The lectin binding pattern of Merkel cell carcinoma cells indicated that predominantly N-linked glycans and not O-linked glycans, typical for mucins of most epithelia, were present. Hence these tumor cells were relatively undifferentiated and resembled stem cells more closely than differentiated epithelia. The tumor stroma was especially evaluated in this study and showed a lectin reaction, which was intermediate between the tumor cells and extra-tumoral stroma. For example, the reactions of N-Acetyl galactosamine-specific lectins were intensive in the extra-tumoral stroma but nearly negative in tumor cells, while the lectin reaction of the intra-tumoral stroma was similar to the cellular reaction. These results indicated an influence of tumor cells on the stromal constituents. Antibodies against chondroitin type glycosaminoglycans reacted with the tumor stroma and the pericellular substance around the tumor cells most intensely in - and around the major tumor septae which, in general, were well vascularized. The most intensive immunoreactivity was detected using the chondroitin-6-sulfate antibody. The cellular and membrane-associated reaction for heparan sulfate was less intensive in comparison to epidermal cells. In conclusion the pattern of lectin-binding sites, the high chondroitin(sulfate) specific reactivity and the relatively low intensity of heparan sulfate immunohistochemistry indicate a low degree of differentiation and high malignity of the tumors, which is consistent with the clinical behavior of Merkel cell carcinomas.

Biomarkers, Tumor↗
PubMed2001

Lectin and proteoglycan histochemistry of feline pacinian corpuscles.

We studied carbohydrate residues of glycoproteins and proteoglycans (PGs) in peritoneal Pacinian corpuscles of five adult cats. Terminal monosaccharides of glycoproteins and related polysaccharides were identified by lectin histochemistry and the PGs and glycosaminoglycans (GAGs) by specific antibodies. The most intensive lectin staining reactions indicated an abundance of glycoconjugates with terminal mannose (Man) or sialic acid residues, but no complex-type oligosaccharides were detected within the corpuscles. Terminal fucose (Fuc) and galactose (Gal) residues typical for O-linked mucin-type glycoproteins generally associated with high water binding capacity were also absent. Antibodies against unsulfated chondroitin (C-0-S), chondroitin-4-sulfate (C-4-S), and decorin showed positive reactions in the interfibrillar spaces between the lamellae, around collagen fibers, and around the lamellae of the perineural capsule, especially in the outer parts known to contain Type II collagen. Biglycan showed a preference for the innermost part of the perineural capsule (intermediate layer), known to contain Type V collagen. Collagen V and biglycan are both linked to growth processes. Hyaluronic acid (HA), chondroitin-6-sulfate (C-6-S) chains, and a chondroitin sulfate proteoglycan (CSPG) were co-localized in the terminal glia. The study of carbohydrates with high water binding capacity may contribute to our understanding of the high viscoelasticity of Pacinian corpuscles.

Animals↗
PubMed1999

Proteoglycan distribution pattern during aging in the nematode Caenorhabditis elegans: an ultrastructural histochemical study.

Glycosaminoglycans are important constituents of the extracellular matrix of vertebrates, where distinct changes in their distribution pattern occur during aging. However, little is known about their changes in the nematode Caenorhabditis elegans, which ages extremely rapidly compared to mammals. The presence of glycosaminoglycans was analysed in cross-sections of all organs of the nematode, in three different age groups (60, 144, 228 h), using the electron-dense dye Cuprolinic Blue in conjunction with the critical electrolyte concentration method and specific glycosaminoglycan degrading enzymes. The nematodes (strain DH 26) were grown at 25.5 degrees C. The results indicate the presence of an organ-specific distribution pattern. Chondroitin-4-sulphate and/or chondroitin-6-sulphate are present in the epicuticula. Chondroitin-4-sulphate and/or chondroitin-6-sulphate and dermatan sulphate are detected in the mesocuticula. If stained by conventional methods the mesocuticula shows an empty fissure, which is filled by chondroitin sulphates and dermatan sulphate as shown by Cuprolinic Blue staining and enzymes. Heparan sulphate is found in the terminal web of intestinal cells while dermatan sulphate is revealed in the central cores of microvilli. An unknown polyanion staining at high electrolyte concentrations is observed in the gonads. Age-related changes do not impair the composition of the glycosaminoglycan fraction. In conclusion an unexpected highly differentiated pattern of glycosaminoglycans with high stability during aging exists.

Aging↗
PubMed1999

Lectin binding pattern and proteoglycan distribution in human eccrine sweat glands.

The distribution pattern of glycoconjugates in human eccrine sweat glands has been studied by the binding of newly discovered lectins and by antibodies against a chondroitin sulphate proteoglycan and chondroitin sulphate glycosaminoglycans. Mannose-specific lectins labelled large intracellular granules, part of which could be extended cisternae of the endoplasmic reticulum or Golgi apparatus. In contrast, lectins specific for terminal mannose/glucose residues predominantly labelled basement membranes and the glycocalyx. Lectins recognizing terminal N-acetylgalactosamine groups left most parts of the glands unstained, but stained some dark cells intensely. These last cells were also intensively labelled by N-acetylglucosamine-specific and by fucose-specific lectins. Sialic acid residues were preferentially located in luminal borders of secretory coils. No terminal galactose residues were detected. All antibodies against chondroitin glycoconjugates stained large granules similar to those revealed by the mannose-specific lectins in the secretory cells. The basement membrane is only stained by the proteoglycan antibody and the chondroitin-6-sulphate antibody. Thus, a complex composition of glycoconjugates exists not only in matrix elements but also in the cells of eccrine glands of the human skin. A possible secretion of glycoconjugates is discussed.

Chondroitin Sulfate Proteoglycans↗
PubMed1990

[Histotopochemical quantification of glycosaminoglycans in melanomas and the surrounding epidermis].

15 cases of human malignant melanoma were studied and classified into 5 superficial speading (SSM), 5 nodular melanomas (NM), and 5 melanoma metastasis (Met). The tissue was fixed with formaldehyde and cetylpyridium chloride (CPC). Glycosaminoglycans (GAG) or proteoglycans respectively were characterized by Alcian blue staining following the method of critical electrolyte concentration (CEC) (Scott, Dorling 1965) and by testes hyaluronidase. The staining intensities were quantified by a Leitz MPV photometer microscope in basement membranes (BM) and tumor septa. Tumor septa, which may be looked on as correlates of epithelial BM material, show increased straining intensities as compared to the normal BM (nBM) around the tumor. It is concluded from the sensitivity to testes hyaluronidase and the straining pattern that these are caused by increased straining of GAG of the type of chondroitin sulfates and possibly of dermatan sulfate while unsulfated GAG are rather decreased. The GAG pattern in BM in SSM shows characteristics of tumor septa and of nBM as well. The staining of the tumors shows higher intensities than that of all structures in the normal skin. It is concluded that increasing malignancy is accompanied by increasing changes in GAG which can be quantified by the method used topohistochemically discerning the healthy tissue from malignant structures.

Adult↗
PubMed1988

Embryotoxic effects of thalidomide-derivatives in the non-human primate Callithrix jacchus. I. Effects of 3-(1,3-dihydro-1-oxo-2H-isoindol-2-yl)-2,6-dioxopiperidine (EM12) on skeletal development.

The response of pregnant marmosets (Callithrix jacchus) to the thalidomide derivative EM 12 was evaluated. EM 12 was selected for these studies because it is more active than thalidomide and is much more stable for hydrolysis. Skeletal gross structural abnormalities were observed when EM 12 was given to marmosets for 3-7 days during the period between days 49 and 60 post ovulation. Using the treatment schedule finally adapted in our laboratory, i.e. treatment during days 51-57 post ovulation, doses of 5 (or 10) mg EM 12/kg body wt induced the typical limb abnormalities known from man with an 80-100% certainty. In some animals we could observe the typical pattern of abnormalities even with doses as low as 1 mg EM 12/kg body wt. Abnormalities of the skeleton induced during this sensitive period are described. None of these (except some bifurcations of ribs) were seen in any of the ten litters (23 fetuses) serving as controls during the period of the study.

Abnormalities, Drug-Induced↗
PubMed1987

Sulfate incorporation into glycosaminoglycans of human lung fibroblasts as influenced by the number of subcultures and glycosaminoglycan polysulfate.

The influence of a glycosaminoglycan polysulfate (GAGPS) on the glycosaminoglycan (GAG) metabolism was investigated in relation to in vitro ageing of cultured human lung fibroblasts (Flow 2002). The incorporation of 35S-sulfate was determined following proteolytic digestion and specific degradation methods for the individual GAGs. In untreated cultures the pericellular matrix and medium showed a decrease of chondroitin sulfate (CS) 35S-radioactivity of the higher passage numbers, while the pericellular heparan sulfate (HS) showed increasing values. In GAGPS-treated cultures the decrease of 35S-sulfate incorporation into CS and dermatan sulfate of the cells and medium as well as into the pericellular CS was negatively correlated to the passage numbers, since GAGPS preferentially increased the radioactivity in cultures of low passage numbers. The HS values, however, were changed in the same direction as observed in untreated controls. Thus, age-related changes in the GAG metabolism become visible when exogenous GAGPS is used as a stimulus.

Cell Survival↗
PubMed1983

Age-related changes in the composition of proteins in the trabecular meshwork of the human eye.

The composition of the trabecular meshwork proteins of human eyes ranging in age from 36 days to 84 years was examined by polyacrylamide gel electrophoresis and amino acid analysis. Proteins of different molecular weights could be extracted from the tissue with acetic acid. Although their electrophoretic patterns became less distinct with increasing age, proteins of molecular weights ranging from 50 000 to 69 000 always prevailed. The amino acid compositions of the acetic acid-insoluble trabecular meshwork residues revealed the prevalence of collagenous proteins. The peptide maps produced by treatment with cyanogen bromide indicate that most of the fragments solubilized from the trabecular meshwork of younger eyes are derived from type I collagen. Beyond 40 years of age, the trabecular meshwork was resistant to cyanogen bromide and pepsin digestion. A rough estimate of the distribution of collagen types in the trabecular meshwork was based on 3-hydroxyproline/4-hydroxyproline ratios, indicating an age-related increase of type I collagen from about 55 to 70 per cent, and of type IV collagen from about 2 to 5 per cent of the total protein present. During ageing, some of the protein-bound methionine is oxidized to methionine sulfoxide, reaching about 35 per cent of the total methionine content at the age of 20 years and, with a slower rate of oxidation, a mean value of 40 per cent at 80 years of age. Electron-microscopic analysis of specimens remaining undissolved after cyanogen bromide cleavage and pepsin treatment no longer revealed regular collagenous fibrils but rather elastic-like fibers surrounded by wide sheaths consisting of fine fibrils with a regular cross-banding periodicity of 40-50 nm. In addition, clusters of so-called curly (lattice) collagen were found. The amino acid composition of this insoluble material suggests that altered collagen-like molecules prevail among the proteins of the residues.

Adolescent↗
PubMed1982

Synthesis and composition of glycosaminoglycans by cultured human trabecular meshwork cells.

A human trabecular meshwork cell line with a limited number of population doublings was established in monolayer culture. All cultures produced hyaluronic acid, heparan sulfate, chondroitin sulfate, and dermatan sulfate. Following [14C]-glucosamine incorporation into proliferating (phase II) cultures, 70%--80% of the medium glycosaminoglycan label was found in hyaluronic acid and 8%--14% in heparin sulfate. About 60% of the cell-bound activity was associated with hyaluronic acid and 30% with heparan sulfate. Long-term cultivation under nondividing ("senescent") conditions resulted in a change of the pattern of synthesized and excreted (medium) [14C]-glucosamine-labeled glycosaminoglycans with a relative decrease of hyaluronic acid and a relative increase of heparan sulfate.

Aging↗
PubMed1982

Connective tissue aging in the human hypophysis-gonadal system.

The basic issue in our project was to quantify the age-process in the human hypophysis-gonadal system. Of the many aspects of aging, we estimated, using human autopsy material, the content of desoxyribonucleic acid (DNA), of hydroxyproline, of hexosamines and of uronic acids in the hypophysis, testis, and ovary. The respective organs were weighed and homogenised in acid-buffer solution after which, for each of the parameters, 1.0 ml of homogenate was extracted and processed: DNA-estimation according to modified Dische/Seibert (1929) method; hydroxy-proline according to Stegemann and Stalder (1967); hexosamines and uronic acids according to Gatt and Berman (1966) and Blumenkrantz and Asboe-Hansen (1973) respectively. All values obtained were expressed in micrograms/ml of homogenate. The age investigated ranged from a few days old to 99 years. The DNA-curves for the hypophysis initially showed a decline till about the third decade of life and then remained almost constant with a significant decline up to the senile age. The DNA-curves for the testis and ovary demonstrated a sharp decline initially till the third decade of life, after which the curves remained constant, but showed reduction during higher age. Similar pattern of distribution was also observed for hexosamines, and uronic acids: after the initial decline of uronic acids in the human hypophysis and testis during the first three decades of life and nearly constant values thereafter, hexosamines, together with the uronic acids show minimal decrease in content during the senile period. Contents od hydroxyproline significantly increased in testis, ovary and hypophysis with aging. This biochemically proven age-fibrosis in the human gonads corresponds to the morphologically observed vascular and interstitial sclerosis in the testis and the ovary and may partly help to explain the declined sensitivity of these target organs to hypophyseal stimulation during the aging period.

Adolescent↗
PubMed1982

Changes in cell cultures of bovine corneal endothelium cells as related to donor age and number of passages in vitro.

Aging changes of the acidic glycosaminoglycans (aGAG) were investigated in bovine corneal endothelium cells grown in vitro, using histochemical methods and the determination of hexosamine and uronic acid. The time interval between trypsination and confluency of the monolayer and the cell counts at different time intervals of the same passage number served as parameters for the proliferation capacity of the cultures. A cell line, derived from the eye of a 1,5 year old cattle showed a low proliferation capacity in the first 9 passages, which increased until the 15th passage, to decrease thereafter until the 29th passage. In cells from eyes aged 11 and 12 years respectively the initial proliferation capacity was very low to reach the same values as in cultures of the young eye at the 10th passage but remained constant thereafter. Chromosome counts showed an increased number of hyperploids in late passages of cells from the aging eye with counts around 4n-8n increased to 17% as compared to 5% in the cells derived from the young eye. The cell densities were increased in cultures of high passage numbers. Histochemically the aGAG were shown in the cell nucleus, and the cytoplasm as well as in the intercellular space. In the nuclei of cells from aging eyes and in late passage cells of the young eye they showed an increased resistance against resting hyaluronidase. The hexosamine and uronic acid values were high in early passages of cultures from the young eye and decreased in late passages of the young eye as well as in early passages of cells from the aging eyes. The changes in the aGAG as well as the changes in the cell proliferation are similar comparing early passage cells of aging eyes to late passage cells of the young eyes. But the aGAG changes are more pronounced in cells of eyes aged in vivo. In the eye the proliferation of the corneal endothelium cells is inhibited. As such these cells provide a useful model to comparing in vivo-aging changes of resting cells to changes of the same cells proliferating in vitro.

Aging↗
PubMed1981

[Oxygen consumption and aging in longterm cultures of lens epithelia].

By means of the described technique lens epithelia were cultured in 40 subcultures; at the same time, both the morphological aging processes and oxygen consumption of the cells, were observed using the Warburg respirometer. To date comparable studies are not available. Morphologically, cell enlargement took place in conjunction with signs of degeneration. Oxygen consumption of 2 microliter per hour per 10(5) cells +/- 0.8 remained at a constant level without any significant diurnal rhythm up to subculture 39 and then suddenly fell to about one-fourth of the initial value. As the cells died of an unknown cause, it was concluded that the aerobic metabolism of lens epithelia seemed to be linked to survival without being age related.

Aging↗
PubMed1980

Morphological and histochemical studies in human rib cartilage chondrons of different age groups.

4- to 6-micrometer thick cryostat sections from rib cartilage of human corpses aged 1 day to 92 years were stained with basic dyes, digested with testes hyaluronidase and examined in polarized light. The areas of 50 chondrons in the cartilage periphery and of 50 chondrons in the cartilage center were measured. The anisotropic zones of the chondrons show a decreased size in the cartilage center as compared to those of the periphery. The basophilic zones of the chondrons (territories) were measured only in the cartilage center. The size of their areas is similar to that of the anisotropic areas. The zones of the chondrons with high chondroitin sulfate content as revealed by hyaluronidase (inner territorial zones) are smaller in the cartilage center than in the periphery and decrease with advancing age.

Adolescent↗
PubMed1979

[Histochemical studies on the structure and the age changes of Descemet's membrane in cattle (author's transl)].

Descemet's membrane of 15 cattle-corneas, aged 6 month to 13 years was studied by various histochemical and morphometric methods. 3 zones could be differentiated. Zone 1 is relatively small and does not show significant changes with age; zone 2 comprises the main part of Descemet's membrane, its diameter increased with age. Zone 2 is rich in sulfated glycosaminoglycans. Zone 3, below the endothelial lining, does not develop before the 3rd and 5th year of life and stains different from zone 2.

Aging↗
PubMed1979

Histochemical demonstration of acidic glycosaminoglycans in the cell nuclei of the iris and other tissues.

Using histochemical methods, the presence of acidic glycosaminoglycans in the cell nuclei of 51 human irides and a series of monkey organs was demonstrated. In general, these substances are sensitive to testicular hyaluronidase and chondroitinase ABC and also to Streptomyces hyaluronidase, when using special staining methods. The specificity of testicular hyaluronidase was tested by inhibition with heparin. By simultaneously staining with alcian blue and Feulgen, acidic glycosaminoglycans can be distinguished from the nucleic acids. Sporadically, hyaluronidase-resistant substances with a specific acidic glycosaminoglycan stainability occur. We assume the existence of various acidic glycosaminoglycans in the cell nuclei. Aging changes were not traceable with constancy.

Adolescent↗