Colloidal Iron Staining Research Articles

The Beauty Makers, or the Pleasures of Histology

In the important and at times difficult endeavor of diagnosing a patient's disease, histotechnologists and pathologists share the burden of responsibility and the excitement of discovery. In this joint venture, the pathologist knows the destination and the technologist is the master of the trail. But unlike other technologist/physician binomials, this interaction begets, as byproducts, objects of visual beauty at a continuous rhythm. Those trades and professions that in the course of their daily operation produce pleasurable sensations, are truly privileged. Baseball players, perfume makers, musicians, chefs, craftsmen, and research scientists deeply enjoy what they do. As essentially visual animals, our human nature perceives visual pleasures as particularly powerful and memorable. Compared to ours, other trades and activities come out as drearily monochromatic. New facets of histotechnology have arisen as a result of technological and conceptual progress and of increased and varied demands on the informative potential of tissues. And this new magic is exhilarating. But the old magic is still there. The cloudburst of a colloidal iron stain or the impact of a dramatic trichrome are still needed, requested and appreciated. The emergence of a new pattern, a new arrangement of elements in an everyday H&E makes the world start anew. The age old maxim, kvetchily insisted upon by mothers and teachers, of “look at what you are doing,” is golden advice to the technologist, a key to instant gratification and daily pleasure. (The J HistotechnoL 25:71, 2002)

Type IV Glycogen Storage Disease

A male infant presented with massive hepatomegaly. There was no history of jaundice, fever, weight loss, blood in stool, or acholic stool. He was born at full term without any complications, and the newborn screening test results were normal. The maternal perinatal history was unremarkable for infections, previous blood transfusion, or intravenous drug use. Family history was negative for jaundice, early infantile death, neurodegenerative disorder, or a1-antitrypsin deficiency. Physical examination revealed normal growth and vital signs, no icterus, lymphadenopathy, ascites, splenomegaly, or other systemic abnormal findings. Firm, nontender hepatomegaly was noted 8 cm below the right costal margin. Laboratory results included a total bilirubin level of 0.5 mg/ dL (9 mmol/L); aspartate aminotransferase, 956 U/L (reference range, 0–50 U/L); alanine aminotransferase, 287 U/L (reference range, 0–45U/L); g-glutamyltransferase, 216 U/L (reference range, 5–32 U/L); and alkaline phosphatase, 321 U/L (reference range, 170–580 U/L). Urine was negative for reducing substances. Results for complete blood count, prothrombin time, partial thromboplastin time, total protein, albumin, serum ferritin, cholesterol, and lactate dehydrogenase were all within normal limits. The hepatitis antibody panel (hepatitis B and C, cytomegalovirus, and Epstein-Barr virus) was negative. A percutaneous needle biopsy of the liver showed loss of normal hepatic architecture, bridging fibrosis, and micronodule formation that was confirmed by trichrome stain. Many scattered hepatocytes showed glassy refractile cytoplasmic inclusions (Figure, A), which stained positively with periodic acid–Schiff (Figure, B) and were generally sensitive to diastase digestion. These inclusions appeared light blue with Alcian blue stain and showed coarsely clumped staining with colloidal iron stain (Figure, C). An ultrastructural evaluation of formalin-fixed tissue showed hepatocytes filled with rarefied fibrillar material interspersed with microfoci of normal glycogen (Figure, D). A diagnosis of glycogen storage disease, type IV, was rendered. Type IV glycogen storage disease (type IV GSD), also known as Andersen disease or amylopectinosis, is a rare autosomal-recessive disorder caused by the deficiency of

USEFULNESS OF METACHROMATIC REAGENTS IN DISCRIMINATING BETWEEN CONNECTIVE TISSUE AND EPITHELIAL MUCOPOLYSACCHAHIDES

The present study compares twelve different histochemical methods of demonstrating mucopolysaccharides in normal and diseased tissues. The metachromatic dyes (Azur A and Thionin B) were the most useful stains for distinguishing epithelial mucopolysaccharides, which were orthochromatic, from connective tissue mucopolysaccharides, which were metachromatic. Periodic acid-Schiff, Alcian blue, Southgate rnucicarmine, and Hale colloidal iron stains were useful for the demonstration of mucopolysaccharides in general. However, these stains did not aid in the discrimination of epithelial from connective tissue mucopolysaccharides. Hexamine silver, Acridine orage and blocking of reactive groups by methyl esteriflcation, and saponification are technically inferior and not useful for demonstration of mucopolysaccharides. Keywords: Metachromatic dyes, Mucopolysaccharides, Tissue processing. (Global J Med Sci: 2002 1(1): 19-27)

Can renal oncocytomas be distinguished from renal cell carcinoma on fine-needle aspiration specimens? A study of conventional smears in conjunction with ancillary studies.

The reliability of using fine-needle aspiration (FNA) to distinguish renal oncocytoma (RO), a benign tumor, from renal cell carcinoma (RCC), which has eosinophilic granular cytoplasm, has been questionable. However, it is clinically significant, because radical nephrectomy may be avoided in patients with RO. The authors retrospectively studied the cytologic features and ancillary study findings of RO compared with findings in RCCs with eosinophilic granular cytoplasm to evaluate the reliability of FNA-based diagnosis of RO. The authors reviewed 19 tumors, including 11 ROs, three chromophobe RCCs (CRCCs), three granular variant RCCs (GRCCs), and two eosinophilic variant papillary RCCs (EPRCCs). Smears and cell blocks were prepared using either computed tomography-guided or ultrasound-guided FNA material. Surgical specimens were available for all tumors. Cytokeratin, vimentin, and Hale colloidal iron (HCI) stains were performed on all 19 tumors. Electron microscopy (EM) was available for six tumors. Although most tumors demonstrated their classic cytologic features, the specific diagnosis using conventional smears or even core biopsies was difficult in some tumors, especially ROs, due to the overlapping cytomorphology among these tumors. Cytologic material was obtained from 10 of 11 RO specimens. Of 10 ROs, 8 original FNA-based diagnoses were oncocytic neoplasm. Immunoperoxidase studies revealed that all tumors of each type were positive for cytokeratin, whereas only GRCCs and EPRCCs were positive for vimentin. The two vimentin negative neoplasms, RO and CRCC, could be distinguished by HCI stain, which showed diffuse or focal cytoplasmic positivity in CRCCs and apical/perinuclear staining (73%) or negative staining (27%) in ROs. Ultrastructurally, cytoplasm densely packed with mitochondria was characteristic for oncocytoma. This study demonstrated that ROs can be distinguished reliably from RCCs on the basis of cytologic morphology combined with ancillary studies, including immunostaining with cytokeratin and vimentin antibodies and HCI stain. EM provides additional information to confirm the diagnoses.

Gender-related differences of hyaluronic acid distribution in the human vocal fold.

To quantify the distribution of hyaluronic acid (HA) within the normal human vocal fold and evaluate gender- and age-related differences. Prospective, cross-sectional study by age and gender groups using cadaveric vocal folds to study hyaluronic acid differences. Twenty-five vocal fold halves obtained at autopsy were evaluated from nine adult male (age range, 34-52 y), seven adult female (age range, 21-41 y), four geriatric male (age range, 65-77 y), and five geriatric female (age range 65-82 y) subjects. Midmembranous vocal fold sections were stained for HA using the Muller-Mowry colloidal iron (acid mucopolysaccharide) stain with and without hyaluronidase. Digital imaging software was used to quantify the distribution of HA across the lamina propria at the vocal fold edge from superficial (subepithelial) to deep (vocalis muscle). A significant gender difference (P =.03) was noted in distribution when controlled for age. Combined, male subjects had a relatively constant distribution pattern throughout the depth of lamina propria. Female subjects showed relatively less HA in the first 15% of depth (most superficial) but showed more HA in the deeper 40% to 100% (toward vocalis muscle) than in male subjects. Important clinical implications may be extrapolated from our findings. First, relatively less HA in the most superficial area implies less protection from vibratory trauma and overuse and may explain in part why more female than male patients have phonotrauma to phonotraumatic lesions. Second, evaluating the distribution of HA in the normal human vocal fold allows more direction in our application of HA as a therapeutic lamina propria substitute in patients with voice disorders.

Prostatic foamy gland carcinoma with aggressive behavior: clinicopathologic, immunohistochemical, and ultrastructural analysis.

Foamy gland carcinoma is a recently described histologic variant of prostatic adenocarcinoma characterized by abundant foamy cytoplasm and minimal cytologic atypia. The biologic behavior and biochemical nature of the foamy adenocarcinoma cells are unknown. Six cases of prostatic adenocarcinoma with marked foamy appearance were identified from radical prostatectomies. Clinicopathologic, histochemical, immunohistochemical, and ultrastructural analyses were conducted. The patients ranged in age from 50 to 73 years (mean age, 65 years) with preoperative serum prostate-specific antigen levels ranging from 2.7 to 37.5 ng/mL (mean, 15.2 ng/mL). All six cases were bilateral high-volume tumors. Five of six patients had high-grade tumors with extraprostatic extension. The foamy tumor cells were negative for mucin and lipid stains, but were positive for colloidal iron and Alcian blue stain. Ultrastructurally, the foamy cells displayed numerous intracytoplasmic vesicles and numerous polyribosomes. The authors conclude that the foamy appearance of these tumor cells is the result of the presence of numerous intracytoplasmic vesicles, and not the result of the presence of lipid or neutral mucin. This study illustrates that foamy gland carcinoma is a distinctive histologic variant of prostatic adenocarcinoma and is often associated with an aggressive behavior despite its deceivingly benign histologic appearance.

Chondroitin sulfate proteoglycan at the basal lamina beneath high endothelial cells in human palatine tonsils: a light and electron microscopic study using the cationic colloidal iron method.

The basal lamina of high endothelial venules (HEVs) in human palatine tonsils was intensely stained with cationic colloidal iron at pH 1.5 and with aldehyde fuchsin. This basal lamina exhibited a thick and double- or triple-layered structure forming small compartments, in which many lymphocytes were aligned. Digestion with hyaluronidase or collagenase eliminated both the colloidal iron and aldehyde fuchsin stainings of the basal lamina of HEVs. Treatment with chondroitinase ABC reduced colloidal iron staining, but did not interfere with the aldehyde fuchsin staining. Digestion with neuraminidase, keratanase, or heparitinase did not eliminate either the cationic colloidal or the aldehyde fuchsin staining. Digestion with neuraminidase reduced the colloidal iron staining on the luminal surface coat of the HEV. Electron microscopy of ultrathin sections revealed that cationic colloidal iron particles were deposited on the basal lamina of the HEV. The basal laminae of ordinary blood vessels were thin and single-layered, and stained only weakly with cationic colloidal iron. The present study suggests that negatively charged sites in the basal lamina of HEV derive mainly from a proteoglycan complex containing hyaluronic acid and chondroitin sulfate, which firmly binds collagen. This topochemical feature is suggested to be involved in the fascilitating migration of lymphocytes after passage through the endothelial layer.

Renal Oncocytoma with Intracytoplasmic Lumina: A Case Report with Ultrastructural Findings of "Oncoblasts"

The authors present a case of renal oncocytoma with numerous intracytoplasmic lumina in a 45-year-old woman, with an emphasis on the ultrastructural findings of so-called oncoblasts. The tumor was located in the upper pole of the left kidney, measuring about 3.3 cm in diameter. Histologically, it was composed of solid nests or acinar growths of so-called oncocytic tumor cells with numerous intracytoplasmic lumina and scattered foci of so-called oncoblasts. The luminal surface was positive for Halés colloidal iron stain. A very small number of glycogen-containing cells were found scattered in a few nests. Immunohistochemically, tumor cells were positive for cytokeratin and epithelial membrane antigen, but negative for vimentin and carcinoembryonic antigen. The Ki-67 labeling index was 1.2%. All of the Ki-67-positive cells were oncocytes. So-called oncoblasts were negative for Ki-67. Ultrastructural examination revealed that the predominant tumor cells had cytoplasm packed with round mitochondria and the mitochodria had lamellar long cristae. So-called oncoblasts showed scant cytoplasm with a moderate numberof small mitochondria. Someof themshowed pyknosis which can be regarded as mitochondrial involution. The authors believe that so-called oncoblasts are damaged or involuted oncocytes rather than precursors of oncocytes.

Opisthorchis viverrini: ultrastructure and cytochemistry of the glycocalyx of the tegument

AbstractThe ultrastructure and cytochemistry of the glycocalyx of the tegument of Opisthorchis viverrini during maturation from newly excysted juvenile to adult stages were investigated using colloidal iron, ruthenium red and lectin stainings. The results showed that the glycocalyx was intensely stained by the first two dyes, thus indicating the presence of relatively high amounts of negative charges. However, the thickness and intensity of the staining decreased during the fluke's maturation. Binding studies using lectin probes on the surface of adult parasites showed that binding sites for Canavaliaensiformis (Con A), Triticum vulgaris (WGA) and Ricinus communis I(RCA I) were present in relative large amounts on the glycocalyx of the adult tegument, whereas those for Dolichos biflorus (DBA) were relatively fewer in number, and those for Ulex europaeus I (UEA I) were absent. The binding patterns of Con A, WGA, RCA I and DBA were generally similar, and the reaction product was uniformly distributed over the dorsal and ventral surfaces of the parasite's body. These bindings, therefore, indicate the presence of D-mannose/D-glucose, N-acetyl-D-glucosamine/sialic acid, D-galactose and N-acetyl-D-galactosamine residues on the glycocalyx of the adult tegument.

Opisthorchis viverrini: ultrastructure and cytochemistry of the glycocalyx of the tegument

The ultrastructure and cytochemistry of the glycocalyx of the tegument of Opisthorchis viverrini during maturation from newly excysted juvenile to adult stages were investigated using colloidal iron, ruthenium red and lectin stainings. The results showed that the glycocalyx was intensely stained by the first two dyes, thus indicating the presence of relatively high amounts of negative charges. However, the thickness and intensity of the staining decreased during the fluke's maturation. Binding studies using lectin probes on the surface of adult parasites showed that binding sites for Canavalia ensiformis (Con A), Triticum vulgaris (WGA) and Ricinus communis I (RCA I) were present in relative large amounts on the glycocalyx of the adult tegument, whereas those for Dolichos biflorus (DBA) were relatively fewer in number, and those for Ulex europaeus I (UEA I) were absent. The binding patterns of Con A, WGA, RCA I and DBA were generally similar, and the reaction product was uniformly distributed over the dorsal and ventral surfaces of the parasite's body. These bindings, therefore, indicate the presence of D-mannose/D-glucose, N-acetyl-D-glucosamine/sialic acid, D-galactose and N-acetyl-D-galactosamine residues on the glycocalyx of the adult tegument.

Chromophobe cell carcinoma and renal cell neoplasms with mucin-like changes

Hale's colloidal iron staining of 8 chromophobe cell carcinomas (CCC) was compared with that of non-chromophobe renal cell carcinomas (RCC), renal oncocytomas, and renal adenomas. Six non-chromophobe RCC showing diffuse and moderate cytoplasmic staining contained extensive areas with translucent cytoplasm as observed in CCC. Seventeen of 25 conventional RCC of the clear cell variant (randomly chosen from 130 cases), 21 of 26 RCC with areas of chromophilic cytoplasm, and 16 of 20 papillary RCC, 7 of 14 adenomas and 14 of 16 oncocytomas displayed focal areas with mild to moderate staining of the cytoplasm. Hale's colloidal iron staining was partially reduced by digestion with neuramidase but not with hyaluronidase. This positive staining demonstrated glycoproteins containing sialylated glycoconjugates, probably a type of acid epithelial mucin. We suggest that there is a spectrum of mucin-like changes in typical CCC representing RCC with extensive and marked "mucin-like changes". The eosinophilic variant of CCC and some RCC with extensive chromophobe cell features represent renal neoplasms with moderate changes. The other RCC, oncocytomas and papillary renal neoplasms with mild to moderate staining with Hale's colloidal iron represent renal neoplasms with focal mucin-like changes. RCC with extensive chromophobe cell features may pose a differential diagnostic problem with CCC.

Proliferation of Type II Pneumocytes and Alteration in Their Apical Surface Membrane Antigenicity in Pulmonary Sarcoidosis

To evaluate both the proliferation of type II pneumocytes in the alveolitis associated with pulmonary sarcoidosis and any alteration in their surface membrane antigenicity. We investigated 20 transbronchial lung biopsy (TBLB) specimens from 20 patients with pulmonary sarcoidosis, 7 TBLB specimens from 7 sarcoidosis patients without pulmonary involvement, and 19 normal lung specimens, using colloidal iron stain and immunostaining with anti-Thomsen-Friedenreich (TF) antigen and anti-surfactant protein-A monoclonal antibodies. The density of type II pneumocytes was significantly higher in the pulmonary sarcoidosis specimens ([mean +/- SD] 11.1+/-3.7 per 1 mm alveolar septal length) than in the nonpulmonary sarcoidosis (7.8+/-1.3) or normal lung specimens (7.2+/-0.8). TF antigen was directly expressed on the apical surface of some type II pneumocytes in the pulmonary sarcoidosis specimens, but it was completely masked by sialic acids in the nonpulmonary sarcoidosis specimens and in the normal lung tissues. In pulmonary sarcoidosis, type II pneumocytes proliferated and the antigenicity of the surface membrane was altered. It is suggested that these type II pneumocytes may be vulnerable to injury by natural anti-TF antibodies that are cytotoxic when present with complement. This damage may decrease alveolar surfactant and cause focal alveolar collapse proceeding to pulmonary fibrosis in some cases of pulmonary sarcoidosis.

Increased Stromal Colloidal Iron Staining Corresponds Well to the Areas of CD34 Staining of Tumor Cells in Dermatofibrosarcoma Protuberans and May Be Useful in Evaluation of Margins.

Menon, P.; Smith, K. J.; Barrett, T.; Rolfe, A.; Welch, M.; Crittenden, J.; Skelton, H. G. Author Information

Colloidal iron staining in renal epithelial neoplasms, including chromophobe renal cell carcinoma: emphasis on technique and patterns of staining.

Positive staining with Hale's colloidal iron stain, or modifications thereof, is considered a diagnostic feature for chromophobe renal cell carcinoma and has been used as a discriminatory feature to differentiate it from other renal tumors. We studied colloidal iron staining in 62 cases encompassing a wide histologic spectrum of renal neoplasms (14 chromophobe renal cell carcinomas, 19 renal oncocytomas, 11 each of granular variants and conventional clear cell renal cell carcinomas, and 7 eosinophilic variants of papillary renal cell carcinoma) to investigate the specificity of the stain for chromophobe renal cell carcinoma. In cases of chromophobe renal cell carcinoma, sections from two different areas were stained to ascertain whether there was any spatial variation in staining. Influence of staining techniques on the results also was investigated by staining each case of chromophobe renal cell carcinoma using two different methods: the traditional Hale's and a modified Mowry's technique, which treats sections with 3% acetic acid before adding the colloidal iron. Our results show that positive staining with colloidal iron stain is not limited to chromophobe renal cell carcinoma, however, a diffuse and strong, reticular staining pattern was observed only in cases of chromophobe renal cell carcinoma (14 of 14). The staining patterns were less consistent in all other renal neoplasms and differed from the reaction observed in chromophobe renal cell carcinoma. Most renal oncocytomas (16 of 19) had focal and weak, fine dustlike positivity, and all clear cell carcinomas showed focal, coarse, dropletlike positive staining (22 of 22), in addition to a focal, coarse, bubbly pattern in 5 of 11 clear cell subtypes. Although all seven cases of the eosinophilic variant of papillary renal cell carcinoma showed strong, coarse, dropletlike staining, most of the positivity was coincident with the Perl's (prussian blue) reaction, indicating that the staining was due to hemosiderin, which is frequently present in this histologic subtype of renal cell carcinoma. Staining intensity did not vary considerably among different areas of chromophobe renal cell carcinoma, but the modified Mowry's method yielded brighter and sharper reticular staining, as compared with the Hale's method. Our results show that in the appropriate morphologic context diffuse and strong reticular positivity using the modified Mowry's colloidal iron stain method is highly characteristic for chromophobe renal cell carcinoma. Treatment of sections with 3% acetic acid before adding the colloidal iron gives technically superior staining results.

Localization of membrane-associated sialomucin on the free surface of mesothelial cells of the pleura, pericardium, and peritoneum

Strong anionic sites, as recognized by deposition of cationic colloidal iron even at pH 1.5, were distributed on the free surfaces of the mesothelia of the mouse pleura, pericardium, and peritoneum. Methylation inhibited colloidal iron staining on the surface, and successive saponification restored it. Digestion with neuraminidase or hydrolysis of sialic acid with H2SO4 erased the colloidal iron staining. Lectin Limax flavus agglutinin (LFA), which is specific for sialic acid, labeled the free surface of the mesothelium. All these findings strongly suggested that the surface substance contained sialic acid. Moreover, prior treatment with LFA inhibited the mesothelial surface stain with colloidal iron. In transmission electron microscopy, the colloidal iron (pH 7.3)-stained substance took the shape of fine strands of 50-300 nm in length. These characteristics of the substance on the mesothelial surface correspond well with biochemical properties of membrane-associated sialomucin, whose strong and abundant negative charges produce repulsive forces between facing serosal surfaces. This may contribute to prevent serosal adhesion and to reduce friction during movements of organs.

Fine-needle aspiration of chromophobe renal cell carcinoma. Analysis of six cases.

The chromophobe variant of renal cell carcinoma is a recently described and frequently unrecognized tumor. Because the prognosis of the chromophobe variant appears to be intermediate between that of oncocytoma and the clear cell variant of renal cell carcinoma, accurate diagnosis may be important for appropriate clinical management. A retrospective analysis of fine-needle aspirations of four primary and two metastatic chromophobe renal cell carcinomas (five typical and one eosinophilic variant) with histologically confirmed primary tumors was performed. Hale's colloidal iron stain was strongly positive in a diffuse cytoplasmic pattern in all resected primary tumors. All fine-needle aspirations were characterized by cellular smears comprised of single cells and small groups of cells. The cytoplasm varied from granular to flocculent. A characteristic feature was the presence of occasional markedly enlarged, bizarre, often multinucleated cells, within a background of moderately atypical cells. Nuclear enlargement, hyperchromasia, pleomorphism, and outline irregularity were noted in all cases. These features imparted a koilocyte-like appearance to many of the cells. Intranuclear pseudoinclusions were present in four cases and were numerous in two. Both primary and metastatic chromophobe renal cell carcinomas have unique cytologic features that allow for their distinction from oncocytoma and other variants of renal cell carcinoma.

Myxoid Tissue: Its Morphology, Histochemistry, and Relationship with Other Supporting Tissues.

Myxoid tissue was studied in the supporting organ of the cat epiglottis ("epiglottic cartilage"). Under the light microscope, myxoid tissue was characterized by stellate cells placed into an avascular acidic extracellular matrix. This extracellular matrix was alcianophilic at pH = 2.5, reacting with the colloidal iron stain, and staining metachromatically with toluidine blue O at pH = 5.0. Treatment of sections with testicular hyaluronidase abolished these reactions. In addition, staining persisted after methylation/saponification pretreatment, indicating hyaluronic acid as the main acidic component of myxoid extracellular matrix. Under the electron microscope, myxoid extracellular matrix formed flocculent electron dense precipitates. Stellate myxoid cells were characterized by bundles of intermediate (8 nm) cytoplasmic filaments. Myxoid cells were devoid of a basal lamina, contained a few small lipid droplets, and stored some glycogen. Bundles of collagen fibrils, 80-120 nm in diameter, were seen in myxoid areas. Myxoid cells reacted to S-100 protein, glial fibrillary acidic protein, and neuron specific enolase. Moreover, in adult animals, myxoid cells stained for neurofilament protein 200. All these markers were also present in chondrocytes of elastic and fibrous cartilage, indicating a close relationship between myxoid cells and chondrocytes. This was supported by the observation of continuous transitional forms of myxoid tissue into elastic or fibrous cartilage. In 8-week-old kittens, the supporting organ of the epiglottis was found mainly to consist of myxoid tissue with only a few interspersed islets of chondrocytes. It is therefore concluded that myxoid tissue can serve as a precursor of cartilage.

Acquired Immunodeficiency Syndrome and Ocular Calcification

We report the presence of peculiar nonbanded calcification of the cornea in three patients with acquired immunodeficiency syndrome, discovered on postmortem histological examination of the globes. In one patient, multiple calcium salt precipitates also affected other ocular and orbital structures. Calcium deposits were present in the corneal stroma but spared Bowman's layer, as is usually seen in primary and secondary corneal calcification. The calcified areas were positive to von Kossa, alizarin red, alcian blue, and colloidal iron stains. Electron probe analysis of the three cases showed the presence of calcium and phosphorus in a ratio characteristic for hydroxyapatite. No predisposing factors could be found. The possible role of associated alterations in the mucopolysaccharide content or composition in the calcified areas is unclear.

Localization of the glycosaminoglycans in the synovial tissues from osteoarthritic knees.

Localization of the glycosaminoglycans (GAG) was examined in the synovial membranes of patients with osteoarthritis under light microscopy using a fine cationic colloidal iron staining method combined with enzymatic digestion. Our staining method was very useful for demonstrating the difference in the localization of GAG in regions of the inflammatory site in the osteoarthritic synovial membrane. Hyaluronic acid was mainly located in connective tissues in the surface intercellular and perivascular spaces, chondroitin sulfate A/C in the highly fibrous part of and connective tissue around blood vessels, dermatan sulfate (chondroitin sulfate B) in the subsurface interstitium and vascular endothelial cells and heparan sulfate in part of vascular endothelial cells. No keratan sulfate was detected. GAG is reported to have an important role in cell movement, adherence and aggregation in the inflammatory sites. These findings should be useful for understanding the role of GAG in physiological and pathologic processes of secondary synovitis.

Membrane-bound glycoconjugates of fetal mouse erythropoietic cells with special reference to phagocytosis by hepatic macrophages.

Using lectin and colloidal iron (CI) stainings in combination with neuraminidase digestion, glycoconjugates on the surface of erythropoietic cells of the yolk sac and liver in fetal mice were examined. Fetal hepatic macrophages were capable of distinguishing between phagocytozed and non-phagocytozed erythroid elements as described in our previous study. Marked differences between these two elements could be ultrahistochemically detected on their cell surface. The phagocytozed elements, such as nuclei expelled from erythroblasts and degenerating primitive erythroblasts, faintly bound neuraminidase-sensitive CI, and neuraminidase digestion imparted a weak peanut agglutinin (PNA) binding. In contrast, erythroblasts at various maturation stages, erythrocytes and normal primitive erythroblasts heavily bound neuraminidase-sensitive CI, and neuraminidase digestion imparted a moderate PNA binding. No differences in binding of either concanavalin agglutinin, Ricinus communis agglutinin-I or PNA were noted between phagocytozed and non-phagocytozed erythroid elements. Desialylation appears to be one of the most important signs for the recognition mechanism of fetal macrophage phagocytosis. During maturation of hepatic erythroblasts, sialic acid changes its affinity for Limax flavus agglutinin from strong to weak, and soybean agglutinin binding sites disappear at the basophilic erythroblast stage. Glycoconjugates on polychromatophilic erythroblasts acquire similar compositions to those of erythrocytes.