Differences In Staining Patterns Research Articles

Expression of receptors for insulin-like growth factor-I and transforming growth factor-beta in human follicles.

The in-vitro growth of immature oocytes in early follicles from cryopreserved human ovarian tissues is a new concept in in-vitro fertilization programmes for the treatment of infertile and cancer patients. To better understand the regulatory mechanism of follicular development, immunohistochemistry was used to study the expression of insulin-like growth factor (IGF) type I receptor (IGF-IR) and transforming growth factor-beta (TGFbeta) type I (TbetaR-I) and type II (TbetaR-II) receptors in fresh and frozen ovarian tissues from 14 women. Immunoreactivities for IGF-IR and TbetaR-I were present simultaneously in the oocytes of primordial, pre-antral and antral follicles. Staining for both IGF-IR and TbetaR-I was also observed in granulosa cells of primordial, pre-antral and antral follicles. IGF-IR and TbetaR-I also stained in thecal cells of pre-antral and antral follicles. Stromal cells in surrounding ovarian tissue expressed IGF-IR and TbetaR-I at various follicular stages. Unlike TbetaR-I, TbetaR-II was expressed only in the oocytes of primordial and primary follicles, and with weak staining intensity in thecal cells. No significant staining for TbetaR-II was found in oocytes and granulosa cells of antral follicles. There was no difference in staining patterns for IGF-IR, TbetaR-I and TbetaR-II between fresh and frozen ovarian tissues, indicating that cryopreservation might not significantly alter the immunoreactivities of these receptors in frozen ovarian tissue. The results suggest that IGF-I and TGFbeta may participate in the regulation of follicular growth by binding to their receptors through an autocrine or paracrine mechanism. IGF-I and TGFbeta may be useful in regulating the in-vitro or in-vivo maturation of oocytes not only in later follicles but also very early follicles, from cryopreserved ovarian tissues for clinical use in the future.

Quantitative assessment of localization and colocalization of glutamate, aspartate, glycine, and GABA immunoreactivity in the chick retina.

We examined the posthatch chick retina for the frequency of occurrence of localization and colocalization of four amino acid transmitter candidates: glutamate (Glu), aspartate (Asp), gamma aminobutyric acid (GABA), and glycine (Gly) using postembedding methods. We support previous studies of Glu, Asp, GABA, and Gly localization in the direct and indirect functional pathways of the chick retina and extend these studies with new qualitative and quantitative observations. We found that photoreceptors show distinct cellular immunoreactivity for both Glu (Glu+) and Asp+, but not for Gly (Gly-) or GABA. Moreover, there is compartmentalization of Glu and Asp staining within the photoreceptors. All horizontal cells react strongly with Asp and Glu, about three-fourths are GABA+ and three-fourths of these are Gly+. Bipolar cells are uniformly Glu+, heterogeneously Asp+, occasionally Gly+, but GABA-. A majority of amacrine cells stain heterogeneously with all antibodies: 90% are Gly+, slightly more than half colocalize Glu, GABA, and Gly. Furthermore, amacrine cells in the outer two or three rows of cells are more likely to be stained by Gly than Glu, Asp, or GABA. Confirming previous studies, ganglion cells were mostly immunoreactive for Glu and Asp with fewer reactive for GABA and Gly. Strong and distinctly cellular immunoreactivity was found in both central and peripheral retina. Our findings show: 1) there is extensive colocalization of Glu, Asp, GABA, and Gly among most retinal neurons, including some cells that contain all four; 2) cells of the direct functional pathway tend to be labeled by Glu and Asp generally to the exclusion of GABA and Gly, while those of the indirect pathway tend to be labeled by GABA+ and/or Gly+ in addition to Glu+ and Asp+; 3) different cell body layers have distinct patterns of colocalization; and 4) there is no qualitative difference in staining patterns between peripheral and central retina.

Patterns of expressions of transforming growth factor and epidermal growth factor receptor in squamous cell lesions of the urinary bladder.

AIM: To investigate the patterns of expression of transforming growth factor alpha (TGF-alpha) and epidermal growth factor receptor (EGFR) in squamous metaplasia and squamous cell carcinomas of the urinary bladder...

P53 protein immunohistochemical expression in colonic adenomas with and without associated carcinoma

Objectives: P53 protein immunohistochemical (IHC) expression was investigated in a series of colonic adenomas and carcinomas to determine the p53 immunohistochemical expression of adenomas in general compared with carcinomas, the difference in staining pattern between adenomas with associated carcinoma and those without associated carcinoma, and the difference in p53 staining in the usual adenomas (low-grade dysplasia) compared with those harboring high-grade dysplasia. Methods: The study involved a series of 20 adenomas without concurrent carcinoma (group 1 adenoma), 29 adenomas with concurrent carcinoma (group 2 adenoma), and 20 carcinomas. Sections of the paraffin-embedded tissues were stained with DO-7 p53 monoclonal antibody after microwave antigen-retrieval method. Cases with nuclear staining in ≥ 20% of the tumor cells were considered positive. Results: Analysis of results showed that 65% of carcinomas and 37% of all adenomas were reactive with p53 IHC staining ( p = 0.03). With respect to the adenomas, 30% of group 1 and 41% of group 2 adenomas were reactive for p53 protein ( p = 0.42). Conclusions: Our data demonstrate a statistically significant higher p53 expression rate in colonic carcinomas than in adenomas, and that adenomas with concurrent carcinomas are more frequently p53 positive than those without concurrent carcinoma, but this was not statistically significant. Also, p53 expression is more frequent and intense in adenomas with high-grade dysplasia (10/20, 50%) than in ordinary adenomas with low-grade dysplasia (8/29, 28%), which suggests a strong correlation between the degree of dysplasia in colonic neoplasia and p53 expression pattern.

Lectins in the vulva. II. Vulvar intraepithelial neoplasia and squamous cell carcinoma.

This study used lectins as histologic probes to determine the cell surface oligosaccharide expression in different grades and types of vulvar intraepithelial neoplasia (VIN). Lectin binding patterns in metastasizing and non-metastasizing squamous cell carcinomas (SCCs) of the vulva were also compared to correlate lectin binding patterns with metastatic potential and other clinical/tumor characteristics. Twenty cases each of VIN epithelium, metastasizing SCC, and non-metastasizing vulvar carcinoma were randomly chosen from the pathology archives. Sixteen lectins were used to probe individual terminal oligosaccharide residues in formalin-fixed, paraffin-embedded tissue specimens from these cases through an indirect immunohistochemical technique. There were no differences in lectin binding patterns between the different histologic subtypes of VIN. In addition, there were no consistent differences between metastasizing and non-metastasizing primary tumors and no major differences in staining patterns between nodal metastases and the corresponding primary tumors. Furthermore, there was no identifiable correlation between lectin binding patterns and subsequent survival or local or regional recurrence; however, lectin staining of invasive tumor cells did appear to be related to local invasiveness. In addition, positive PNA binding was found to be a constant finding in each of the VIN and invasive SCC cases, confirming that the T-antigen becomes unmasked during the process of vulvar carcinogenesis. However, poorly-differentiated areas consistently showed absent lectin binding, suggesting loss of specific glycosyl transferase activities. In addition, the blood group "A" antigen appears to be lost during the process of tumorgenesis, although the blood group "O" antigen appears to be preserved.

Fourfold reduction of water permeability in inner medullary collecting duct of aquaporin-4 knockout mice.

Aquaporin (AQP)-3 and AQP4 water channels are expressed at the basolateral membrane of mammalian collecting duct epithelium. To determine the contribution of AQP4 to water permeability in the initial inner medullary collecting duct (IMCD), osmotic water permeability (Pf) was compared in isolated perfused IMCD segments from wild-type and AQP4 knockout mice. The AQP4 knockout mice were previously found to have normal gross appearance, survival, growth, and kidney morphology and a mild urinary concentrating defect (T. Ma, B. Yang, A. Gillespie, E. J. Carlson, C. J. Epstein, and A. S. Verkman, J. Clin. Invest. 100: 957-962, 1997). Transepithelial Pf was measured in microdissected IMCDs after 18-48 h of water deprivation and in the presence of 0.1 nM arginine vasopressin (to make basolateral Pf rate limiting). Pf values (37 degrees C; means +/- SE in cm/s x 10(-3)) were 56.0 +/- 8.5 for wild-type mice (n = 5) and 13.1 +/- 3.7 for knockout mice (n = 6) (P < 0.001). Northern blot analysis of kidney showed that transcript expression of AQP1, AQP2, AQP3, and AQP6 were not affected by AQP4 deletion. Immunoblot analysis indicated no differences in protein expression of AQP1, AQP2, or AQP3, and immunoperoxidase showed no differences in staining patterns. Coexpression of AQP3 and AQP4 in Xenopus laevis oocytes showed additive water permeabilities, suggesting that AQP4 deletion does not affect AQP3 function. These results indicate that AQP4 is responsible for the majority of basolateral membrane water movement in IMCD but that its deletion is associated with a very mild defect in urinary concentrating ability.

Detection and distribution of the carbohydrate binding protein galectin-3 in human notochord, intervertebral disc and chordoma

Galectin-3 is an endogenous carbohydrate-binding protein which plays a role in cell differentiation, morphogenesis and cancer biology. We investigated the occurrence and distribution of galectin-3 in the embryonic and fetal human notochord, the developing human vertebral column, adult intervertebral discs and in six chordomas, which are tumors thought to originate from notochordal remnants. By means of Western blots, the expression of galectin-3 was confirmed in tissue probes from the vertebral column region beginning with the 8th gestational week. These results were supported by immunohistochemical data which revealed the presence of galectin-3 in the cytoplasm of cells of the notochord also from the 8th gestational week onwards. Notochordal immunostaining became stronger with increasing gestational age. A persisting notochordal remnant in an adult intervertebral disc and various cells of the nucleus pulposus also contained galectin-3. All chordomas showed moderate or strong immunoreactivity irrespective of their cellular composition. Subcellularly, galectin-3 was localized mostly in the cytoplasm, while a subset of tumor cells also showed nuclear distribution. Differences in staining patterns of chordoma cells could not, in general, be correlated to any histological features of these tumors.

Apoptosis in oral erythema multiforme

Objective. Cell death was evaluated in oral erythema multiforme to test the hypothesis that apoptosis may be a mechanism by which keratinocytes die in this condition. Study design. Ten erythema multiforme and five control oral mucosa biopsy specimens were evaluated in immunohistochemically stained sections for apoptosis-regulating proteins Bcl-2, Bcl-x, Bax, p53, Fas, and Fas-ligand. Apoptotic keratinocytes, determined by a detection method for DNA fragmentation (TUNEL) and by conventional morphologic criteria were counted per high power field. Results. Keratinocyte staining for Bcl-2 protein was comparable in erythema multiforme and controls. Bcl-x expression was reduced in five erythema multiforme cases. Staining for Bax protein differed in six erythema multiforme cases and showed variable intensity in layers under the parakeratin. Only slight differences in staining patterns of Fas and Fas-ligand proteins were noted between erythema multiforme and controls. The number of apoptotic keratinocytes evaluated by morphologic examination was significantly higher in erythema multiforme (mean per high power field, 0.90 ± 0.2; controls, 0.06 ± 0.04; p < 0.05, Mann-Whitney test) and was limited in significance by the TUNEL method (erythema multiforme, 0.43 ± 0.1; controls, 0.02 ± 0.02). Overexpression of p53 protein was seen in basal keratinocytes in five erythema multiforme specimens (mean, 17.5 ± 4.03 per high power field; controls 1.2 ± 0.3). Conclusions. There is evidence that cell death in erythema multiforme is at least in part due to apoptosis. The apoptotic mechanism may be related to an altered expression of apoptosis-regulating proteins. Although measurable alterations in the phenotypic expression of Fas and Fas-ligand proteins were not apparent, activation of Fas/Fas-ligand system could still be involved in the induction of apoptosis in erythema multiforme.

Histochemical demonstration of zinc ions in human epididymis using autometallography.

A recently described autometallographic technique, allowing demonstration of chelatable zinc in human biopsy material, was applied to cryostat sections from biopsies of human epididymis. Sections from the rat epididymis were used as control materials to examine the quality of the method compared with a previously used autometallographic method. The human epididymis exhibits heavy staining in the head of the epididymis and only small amounts of zinc in the body and tail of the organ. The zinc staining was found in the apical part of the ciliated cells and in the lumen. The present technique can be used to localize zinc ions at ultrastructural levels. Zinc grains were localized in lysosome-like bodies and secretory granules of the ciliated cells. The luminal staining was present as free, evenly dispersed zinc grains or attached to sperm cells and stereocilia in the lumen. The large differences in staining patterns along the epididymal tract in humans and rats suggest that zinc ions are important for the maturation of sperm cells.

Lectin histochemistry in rat liver fibrosis induced by heterologous serum sensitization.

The localization of carbohydrates in rat livers with fibrosis induced by heterologous serum was examined by lectin histochemical and biochemical techniques. Twenty-four lectins were used to visualize the different carbohydrates in paraffin sections of normal and fibrotic liver tissues. No differences in staining patterns of these lectins were observed between normal and fibrotic livers in hepatocyte cell membranes including bile canaliculi, sinusoidal endothelial, or bile ductal cells. Kupffer cells strongly stained with Vicia villosa agglutinin (VVA) were seen only in the periportal zone of the normal liver, but they were observed in the periportal zone and scattered throughout the pseudolobular zone in the fibrotic liver. The cytoplasm of some hepatocytes was strongly stained by Bandeiraea simplicifolia lectin-I (BSL-I). BSL-I positive hepatocytes in normal liver were localized in the periportal zone, but those in the fibrotic liver were scattered in the periportal and perifibrous zones. After polyacrylamide gel electrophoresis of liver glycoproteins, differences in molecular sizes of BSL-I positive glycoproteins (79 and 81 kD) were detected by lectin blotting. Cell density of perifibrous BSL-I positive hepatocytes may be useful as a diagnostic parameter for liver fibrosis and/or cirrhosis. Two distinct staining patterns with twelve lectins were observed in fibrotic septa of the fibrotic liver. The fibrotic septa were stained with six characteristic lectins, and the centrilobular septa were stained with all these twelve of lectins. Histopathological assessment of the centrilobular fibrotic septa stained with these characteristic lectins may contribute to the diagnosis and prognosis of hepatic fibrosis.

Different expression of Bcl-2 in diffuse and intestinal type stomach carcinomas

The aim of the present study was to examine immunohistochemically the expression of Bcl-2 in stomach carcinomas in relation to the clinical staging of the patients. Staining with a monoclonal antibody against Bcl-2 was positive in 60% of the 40 investigated carcinomas. A significant difference in staining patterns could be demonstrated, as 87% of the intestinal type tumors and only 44% of tumors of the diffuse type showed positive staining. No specific relation was observed concerning pTNM staging or tumor grading. Four investigated stomach carcinoma cell lines showed strong positive staining. We conclude from our results that the expression of Bcl-2 is a common phenomenon in stomach carcinomas, where it is related to more differentiated tumors, but its detection seems of no direct value for clinical staging of the patients.

The extracellular matrix proteins fibulin-1 and fibulin-2 in the early human embryo.

Fibulin-1 and fibulin-2, two recently identified extracellular matrix proteins with a homologous domain structure, are known to bind various extracellular ligands and calcium. In this study, they have been localized at the light microscopical level in human embryos of gestational weeks 4-10, using polyclonal antibodies. Identical localization patterns were observed for the two fibulins in most of the tissues. In the heart, the endocardial cushion tissue and endocardium, but not the myocardium, were stained, as were the basement membrane zones and adventitia of blood vessels. Staining was also observed in the perichondrium and calcifying regions of developing bones. Moreover, reactions occurred with the gut subepithelium and epithelial basement membranes of the skin. Differences in staining patterns, however, were observed in various neural structures. Fibulin-1 was prominent in the matrix of the leptomeningeal anlage, in basement membranes of the neuroepithelium and the perineurium of peripheral nerves. Fibulin-2 was detected primarily within the neuropithelium, spinal ganglia and peripheral nerves. The early embryonic expression of both fibulins indicates specific roles during organ development and, in particular, involvements in the differentiation of heart, skeletal and neuronal structures.

Avidity distribution of antibodies against peripheral nerve myelin in patients with polyneuropathy associated with IgM monoclonal gammopathy and in healthy controls

To elucidate the role and nature of antibodies against peripheral nerve myelin (PNM) we studied their avidity distribution. Twelve patients with demyelinating polyneuropathy associated with IgM monoclonal gammopathy were compared with 12 healthy blood donors previously found to have anti-PNM antibodies of IgM isotype. For comparison, the avidity distribution of IgM antibodies against the varicella zoster antigen in 10 patients with herpes zoster infection was also studied. Microtitre plates containing antibody bound to antigen were exposed to increasing concentrations of sodium thiocyanate (NaSCN) followed by an ELISA assay. NaSCN changes the ion strength and the pH, and thereby the critical conditions for antibody-antigen binding. Resistance to NaSCN was used as a measure of antibody avidity. Anti-PNM antibodies from patients with monoclonal gammopathy were of predominantly low avidity whereas antibodies from blood donors were of predominantly high avidity. Avidity index, representing the molar concentration of NaSCN required to reduce the initial absorbance values by 50%, was on average 11.7 times higher in blood donors (range 0.24-2.65, mean = 0.82) than in patients with monoclonal gammopathy (range 0.04-0.10, mean = 0.07) ( p = 0.002). On the other hand, patients with monoclonal gammopathy had on average a 100-fold higher relative concentration of antibodies against PNM compared to blood donors (range 4.1–392.6 AU, mean 85.0 AU, and range 0.2-1.7 AU, mean 0.85 AU, respectively) ( p = 0.002). Antibodies against the varicella zoster antigen from patients with herpes zoster showed a high avidity index (range 0.25-2.6, mean = 1.24). Using Western blot, several 14–30 kDa proteins in PNM were found to be the target antigen for IgM anti-PNM antibodies in both patients with monoclonal gammopathy and polyneuropathy, and in blood donors. Additional bands in the 43–67 kDa and > 94 kDa regions were commoner in blood donors than in patients with monoclonal gammopathy and polyneuropathy. These differences in staining pattern may reflect differences in avidity distribution or a qualitative difference at antigen binding sites of the anti-PNM antibodies. In conclusion, we found a strikingly low avidity of anti-PNM antibodies from patients with monoclonal gammopathy and polyneuropathy, and their pathogenetic role could apparently be questioned. However, low avidity implies reduced systemic elimination, with an increased risk of pathological depositions. This together with complement activation is an attractive pathogenetic model.

Immunohistochemical characterization of the 'intimal proliferation' phenomenon in Sneddon's syndrome and essential thrombocythaemia

Cellular changes were immunocytochemically characterized in skin vessels of five patients with idiopathic generalized racemose livedo (Sneddon's syndrome), and one patient with localized racemose livedo associated with essential thrombocythaemia. Antibodies against alpha-smooth muscle-actin, tropomyosin, desmin, vimentin, factor VIII-related antigen, human endothelial cells (CD31), human macrophages (CD68), and HLA-DR positive cells (CR3/43) were used. Conventional light microscopy showed, in all cases, intimal thickening of ascending arteries and arterioles as a result of an accumulation of cells and extracellular hyalinized material. None of the specimens showed infiltration with polymorphonuclear leucocytes or macrophages. The cells in the region of the intimal hyperplasia showed intense positive immunostaining for alpha-smooth muscle actin and tropomyosin. Staining for the intermediate filament desmin was localized to the resident smooth muscle cells of the media, whereas staining for vimentin was found in all types of cells in both the intima and media. Positive immunostaining for factor VIII-related antigen and CD31 was strictly confined to the endothelial cells lining the narrowed lumina of the vessels. No positive staining with either antibody was observed in totally occluded vessels. Cells in the subintimal space did not show reactivity for CD68 in any of the specimens, but two cases showed solitary cells with positive staining for HLA-DR in this region. There were no differences in staining pattern between Sneddon's syndrome and essential thrombocythaemia with any of the antibodies. Our results support the assumption that the 'intimal proliferation' in both diseases is caused by colonization of the subendothelial space with contractile cells of possible smooth muscle origin.(ABSTRACT TRUNCATED AT 250 WORDS)

Bcl-2 expression reliably distinguishes trichoepitheliomas from basal cell carcinomas.

Trichoepitheliomas (TE) are benign follicular neoplasms which are frequently confused with basal cell carcinomas (BCC). It is important to distinguish these entities precisely, as the treatments and prognoses are different. To this end, we stained a series of formalin-fixed, paraffin-embedded specimens of unequivocal TE and BCC with antibodies directed against bcl-2, an oncogene associated with programmed cell death, and known to be overexpressed in some malignant tumours. The TE showed staining of tumour cells limited to the outermost layer of the proliferation. The BCC tumour cells demonstrated diffuse staining throughout the tumour nodules. This difference in staining pattern was then applied to more equivocal cases, and seemed clearly to separate the entities. The observed findings may prove to be of diagnostic help in distinguishing borderline cases, and also offer some possible explanations for the biological differences between these neoplasms.

Immunohistochemical localization of collagen VI in diabetic glomeruli

Late stage diabetic nephropathy is histologically characterized by either diffuse or nodular expansion of the glomerular matrix. This is presumed to represent the morphological correlate for the functional impairment of the kidney. The exact matrix composition of the nodular glomerulosclerosis lesion of end-stage diabetic nephropathy is not known. Biochemical studies have provided evidence that the microfibrillar collagen type VI is increased in diabetic nephropathy. Consequently, this immunohistochemical study was designed to evaluate the extent and exact morphologic location of increased collagen VI deposition at various stages of diabetic glomerulosclerosis (GS). An irregular, sometimes spot-like staining of collagen VI was observed in diffuse GS in the mesangial portion. The uninterrupted staining which was evident along the glomerular basement membrane in normal glomeruli was discontinuous in diffusely sclerotic glomeruli. In nodular GS, the markedly increased deposition of collagen VI appeared to be evenly distributed throughout the entire nodular lesion. At the same time, mesangial staining for collagen IV was reduced in nodular GS, suggesting that in the expanded mesangial matrix collagen IV is progressively substituted by collagen VI during the transition from diffuse to nodular GS. The colocalization of PAS staining with collagen VI deposition in nodular GS suggests that the typical Kimmelstiel-Wilson lesions at least in part consist of collagen VI. Biochemical analysis confirmed the increased collagen VI deposition in glomeruli extracted from diabetic patients with nodular GS. Application of two antisera, recognizing primarily the alpha 1(VI)- and alpha 2(VI)-chains and the N-terminal part of alpha 3(VI)-chain, respectively, revealed no difference in staining pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Length Regulation of Thin Filaments without Nebulin.

Recent work has suggested that the length of thin filaments in skeletal muscles is determined by a protein ruler, nebulin, located along the long axis of thin filaments. To examine the function of nebulin, the length distribution of the thin filaments was investigated by staining actin filaments with fluorescent rhodamine-phalloidin in rabbit cardiac muscles, which do not contain nebulin, and in skeletal muscles, which contain nebulin, by laser scanning confocal microscopy. The microscopic observation showed a difference in staining patterns between cardiac and skeletal muscle fibers when the staining was done without chemical fixation. This suggests that nebulin suppresses the attachment of phalloidin to actin filaments. Analysis of fluorescence distribution showed that the length deviation of thin filaments in the cardiac muscle was as small as that in the skeletal muscle. This indicates that the length of the thin filaments is regulated even without nebulin.

Labeled lectin studies of renal tubular dysgenesis and renal tubular atrophy of postnatal renal ischemia and end-stage kidney disease.

Renal tubular dysgenesis (RTD), with hypoplasia especially of renal proximal convoluted tubules and clinical neonatal anuria or oliguria, has been reported as a congenital familial (autosomal recessive) disease, variably with features of oligohydramnios, Potter syndrome, or pulmonary hypoplasia. A similar tubular lesion due to antenatal tubular atrophy has been reported for conjoined twins with twin-twin transfusion syndrome or acardia and in infants of mothers given antihypertensive agents, including angiotensin-converting enzyme (ACE) inhibitors, during pregnancy, and it has been seen as a unilateral lesion in young infants with renal artery stenosis due to arteritis or medial arterial calcinosis. The renal tubular changes in RTD are very like those of the "endocrine kidney" in experimental animals and resemble those of the renal tubular atrophy of end-stage kidney diseases such as glomerulonephritis, tubulointerstitial kidney disease, obstructive uropathy/pyelonephritis, graft rejection of transplanted kidneys, or the renal parenchymal changes seen with protracted dialysis therapy. Labeled lectins that differentially mark proximal convoluted, distal convoluted and connecting, and collecting tubules showed no distinctive differences in staining patterns of the hypoplastic renal tubules of infants and children with RTD, postnatal renal artery obstruction, or the various types of end-stage renal disease with the lectins used (PNA, GSLI, UEA, and LTA). The findings suggest that the renal tubular changes in some if not all the conditions studied are the result of renal ischemia. The reported familial RTD with hypernephronic nephromegaly may be a specific disorder, but other forms could reflect renal ischemia acquired in utero or in early or later postnatal life.

The expression of keratins, vimentin, neurofilament proteins, smooth muscle actin, neuron-specific enolase, and synaptophysin in tumors of the specific glands in the canine anal region.

Eight canine tumors originating from specific glandular structures in the anal region, as well as metastatic tumor tissue of two of these cases (case Nos. 7, 8), were immunohistochemically analyzed using various monoclonal antibodies (MoAbs) directed against human keratin types, vimentin, neurofilament proteins, and alpha-smooth muscle actin. These tumors also were stained for the broad-spectrum neuroendocrine markers neuron-specific enolase (NSE) and synaptophysin. In histologically normal canine anal structures, alpha-smooth muscle actin and NSE antibodies stained basally localized (probably myoepithelial) cells in the anal glands and the anal sac glands. NSE staining also was present in a limited number of luminal cells in both anal glands and anal sac glands. Synaptophysin labeling was not observed in any of these glandular structures. Histologically, the tumors were differentiated into well- and moderately differentiated perianal gland tumors (n = 5) and carcinomas without perianal gland differentiation (n = 3), corresponding to the so-called apocrine carcinomas of the anal region. Immunohistochemically, the perianal gland tumors could be differentiated from the carcinomas by marked differences in staining pattern with the various keratin MoAbs, particularly MoAbs directed against human keratin types 7 and 18. The keratin-staining characteristics of the carcinomas suggest a glandular luminal cell origin. Metastases of the carcinomas showed loss of some keratin-staining characteristics as compared with the primary tumor. Staining for NSE was only observed in solitary cells and small cell clusters in the carcinomas and their metastases, whereas the alpha-smooth muscle actin antibody did not react with the carcinoma cells. None of the tumors stained for neurofilament proteins or synaptophysin. An unequivocal neuroendocrine nature of the carcinomas could not be substantiated by our immunohistochemical study, although the presence of a population of neuroendocrine cells within these neoplasms seems likely. Because the immunohistochemical features of the carcinomas with respect to various keratin MoAbs and NSE are similar to those of the anal glands and the anal sac glands, both these glands might be considered as site of origin of these carcinomas.

Immunohistochemical characteristics of Hodgkin and Reed‐Sternberg cells in relation to age and clinical outcome

One hundred and fifty-four cases of Hodgkin's disease diagnosed between 1985 and 1988 from an unselected population were stained with a panel of six monoclonal antibodies; LN1, MB2, L26 (CD20), all B-cell antibodies, UCHL1 (CD45 RO), mainly T-cell antibody, Leu M1 (CD15), Ber H2 (CD30) and the polyclonal CD3, T-cell antibody. The results were related to age, histopathological subgroup and prognosis. There was no significant difference in staining patterns in the 90 patients below the age of 60 compared with the 54 patients above that age. In the entire group, significantly fewer mixed cellularity cases were positive with Ber H2 and Leu M1 compared to nodular sclerosis. Disease-free survival tended to be better for cases stained with T-cell related antibodies. This study thus indicated differences in behaviour between T-cell positive and negative Hodgkin's disease and that there are antigenic differences between nodular sclerosis and mixed cellularity subgroups. We could not, however, show any phenotypic differences between the tumour cells in young and old patients.