“Placental polyp”: Light microscopic and immunohistochemical observations

A case of the chronic type of placental polyp, occurring in a 37-year-old woman approximately 9 years after abortion of her last known pregnancy, is reported. The placental polyp was predominantly composed of necrotic and hyalinized chorionic villi without identifiable lining trophoblast; however, some villi showed a thin rim of apparently viable syncytiotrophoblast that exhibited focal strong positivity for human chorionic gonadotropin by immunohistochemical studies. Intermediate trophoblast, especially abundant within the intervillous fibrin, appeared most viable and showed strong positivity for human placental lactogen (hPL); syncytiotrophoblast also showed focal positivity for hPL. The basal aspect of the polyp was composed of abundant decidua that contained dilated and ectatic blood vessels. This study demonstrates the presence of cytoplasmic markers for pregnancy in a chronic type of placental polyp, apparently of 9 years' duration, and draws attention to an entity that may be encountered more frequently due to the current prevalence of induced abortions.     

Electron microscopic study of involuting thymus of “lethargic” mutant mice

The thymus, which undergoes spontaneous involution three weeks after birth in “lethargic” mutant mice, was studied by electron microscopy. Ultrastructural alterations observed in the involuting thymus of “lethargic” mice resemble those of acute thymic involution induced by the administration of adrenal corticosteroids. The responsive cells in thymic involution of “lethargic” mice were cortical thymocytes, macrophages, and epithelial cells. The first indication of the involution was the appearance of a large number of degenerating thymocytes in the cortex. Pyknotic nuclei of degenerating thymocytes were observed within the macrophages. Macrophages of the involuting thymus were characterized by their content of thymocyte pyknotic nuclei as well as a variety of cytoplasmic inclusions. Cytoplasmic inclusions were also found in the epithelial cells. The inclusions were of two different types: (a) tonofibrils in markedly increased numbers in relation to a non-involuted thymus, and (b) large vacuoles with dense bodies and/or myelin figures, as found in a normal cell, but several times the number one would expect to find. A large number of lipid-laden cells were found in the involuted thymus. This type of cell was not seen in the normal thymus. Numerous Hassall's corpuscles were also found in the involuted thymus of “lethargic” mice.     

Fragile X “gray zone” alleles: AGG patterns,expansion risks,and associated haplotypes

The risk for fragile X “gray-zone” alleles to expand appears to depend on the absence of stabilizing AGGs, which interrupt the CGG repeat region. To characterize such alleles better, we analyzed a series of 101 chromosomes with triplet repeat lengths ranging from 35 to 59 for variations in their AGG interspersion patterns. Among these, 11.9% had 3 AGGs, 59.3% had 2, 24.8% had 1, and 4.0% had 0. An inverse relationship between FMR1 repeat length and the number of interrupting AGGs was observed. Within the range of 35–44 repeats, 98.7% of alleles were found to have a pure CGG repeat length (P_CGG) of less than 33. However, among alleles with 45–59 repeats, 50% were found to have 0 or 1 AGG and a P_CGG of more than 33. Thus, gray-zone alleles with 45–59 repeats frequently have a long stretch of pure CGGs and thus are more likely to be unstably inherited than alleles with 35–44 repeats. We found length associations of P_CGG with 2 flanking microsatellites, DXS548 and FRAXAC1: a P_CGG ≤20 was strongly associated with haplotype 20−19, whereas a P_CGG > 20 was more strongly associated with the haplotype 25−21. This result could reflect a founder effect or a generalized instability of CGGs and microsatellites. © 1996 Wiley-Liss, Inc.     

An electron microscopic study of the modification by monosodium glutamate of the retinas of normal and “rodless” mice

By the use of DNA determinations and cell counts with and without previous colchicine treatment, the absolute numbers of villus epithelial cells, and of dividing and nondividing crypt epithelial cells were determined in ten successive segments of the small intestine of 17-day (weanling), 37-day (young) and 87-day old (adult) male rats. In adults, the number of villus epithelial cells per segment decreased gradually in the duodenoileal direction, while the number of dividing and nondividing crypt epithelial cells remained fairly constant. It was deduced that the turnover time of the villus epithelium gradually decreases, but that of the crypt epithelium remains constant along the small intestine. When the entire small intestine was considered, from weanling to adult age, the relative and absolute numbers of dividing and nondividing crypt epithelial cells increased; the calculated number of epithelial cells produced daily rose from 112 million to 1796 million. Meanwhile, the rate of growth of the intestinal epithelium diminished allowing more and more of the produced cells to participate in renewal: about 25, 885 and 1796 million cells daily in weanling, young and adult rats, respectively. The mean turnover time of the intestinal epithelium decreased from about 22 days in weanling rats to about 2.1 days in adult rats, indicating a tenfold increase in renewal rate.     

“Sternzellen” in the liver: Perisinusoidal cells with special reference to storage of vitamin A

The “Sternzellen” (von Kupffer, 1876) in the liver of normal animals and of those injected with excess vitamin A were examined with the light and electron microscopes. These cells were stellate perisinusoidal cells located in the space of Disse and were separated from the sinusoidal lumen by the endothelium. Their cytoplasm contained a number of lipid droplets which reacted intensely with gold chloride. These lipid droplets imparted intense vitamin A fluorescence under the fluorescence microscope. Following the administration of excess vitamin A, these lipid droplets increased remarkably. The “Sternzellen” were identical with cells described as “interstitial” or “fat-storing” cells by others, and were quite different from the so-called Kupffer cells of the liver reticulo-endothelial system.     

Nonantibiotic effects of macrolide antibiotics of the oleandomycin-erythromycin group with special reference to their “steroid-sparing” effects

Certain macrolide antibiotics, such as troleandomycin (TAO), oleandomycin, and erythromycin estolate (Ilosone), can lower the maintenance dose of glucocorticoids required by severely asthmatic patients. These effects were postulated to be caused by an as yet undefined steroid-sparing effect. In this study, TAO in combination with methylprednisolone, when compared with methylprednisolone alone, was demonstrated to significantly increase liver glycogen deposition in adrenalectomized mice, intact mice, and adrenalectomized rats; protect histamine-sensitized mice following beta adrenergic blockade or adrenalectomy; further decrease the steroid-lowered glucose tolerance of mice and significantly increase the plasma corticosteroid levels in rats. TAO alone did not have these effects. TAO plus betamethasone, and erythromycin estolate plus methylprednisolone also increased liver glycogen deposition. However, TAO did not appear to potentiate the effects of hydrocortisone. Erythromycin stearate and to a lesser degree erythromycin ethylsuccinate when combined with methylprednisolone also decreased histamine lethality in mice. Leucomycin and tetracycline did not enhance the effects of methylprednisolone. TAO, alone or with methylprednisolone, did not alter serum glutamic oxaloacetic transaminase (SGOT) levels in rats. Thus, TAO and some other macrolides did not exert their effects on corticosteroids as antimicrobial agents, adrenocorticotropic hormone (ACTH)--like compounds, or quasisteroids, but as steroid-sparing agents by some undefined mechanism.     

Critique of “an electron microscope study of crystal calcium carbonate formation in the mouse otolith”

Electron micrographs of otoconia of fetal mice, as obtained by Nakahara and Bevelander, provide morphological evidence that the otoconia consist of both organic material and calcium carbonate (calcite), contrary to their own conclusions. Calcite is an integral component of otoconia, apparently from their inception. The concept of mineralization by calcite of an already developed organic template (“preotolith”) is shown to be in error.     

Fourier transform infrared spectroscopic study of polyacetylene, 1. Spectral assignment and characteristics of Z/E (“cis”/“trans”) geometric isomers

An FTIR spectroscopic study was carried out for rare-earth polyacetylenes

1 IUPAC name: poly(vinylene).

(PA) containing both Z (“cis”) and E (“trans”)

2 We distinguish formally between configurations (Z, E = “cis”, “trans”) and conformations (cis, trans), though in the case of poly(vinylene) the physical quality is virtually the same.

geometric isomers. Spectral assignments were made by the study of PA samples with different Z/E ratios and by referring to the known assignment of the IR spectrum of PA obtained with Ti(OC₄H₉)₄·Al(C₂H₅)₃. The conjugation effect of Z or E ? CH?CH? sequences and their length distribution in PA are investigated by spectral subtraction and peak separation. It is shown that the frequency of v(CH) (out-of-plane deformation) is located in the regions 741 to 747 cm^?1 and 940 to 1014 cm^?1 for Z- and E-PA, respectively, depending on the conjugation length. At the beginning of thermal isomerization of Z-PA, long Z sequences are interrupted quite frequently; this causes a shift of v(CH) towards higher frequencies. In high E-PA obtained by thermal isomerization of Z-PA, uninterrupted long E sequences persist. This demonstrates that a crosslinking reaction between PA chains is not conspicuous during the thermal isomerization process.     

The development of the spleen in the Australian lungfish,Neoceratodus forsteri Krefft,with special reference to its relationship to the “gastro”-enteric vasculature

The spleen of Neoceratodus forsteri Krefft grows in the shape of a “boomerang” on the left lateral-dorsal-right lateral part of the borderline between the foregut and the yolkgut. Development of the spleen follows the following stages: (1) appearance of the splenic primordium as a mesenchymal condensation in a limited portion of the region supplied by the third and fourth vitelline arteries on both sides, (2) development of the splenic sinuses within the primordium, (3) formation of the “gastric” and enteric splenic portal systems and (4) growth of the spleen along the anterior extremity of the spiral valve. The blood vascular dynamics of the foregut and the yolkgut are intimately involved with the formation of the spleen in this species. These processes were, therefore, compared with similar processes in other animals, and the characteristics of this organ common to vertebrates were investigated.     

“Silver dust”—a tool to study growth interrelationships between bone,periosteum and muscle

A cylinder of gelatin containing silver spongy granules was placed in and lay within the masseter muscle, the periosteum, and the mandible, and terminated in the medial pterygoid muscle of young (3 month-old) growing miniature pigs. On the basis of an animal sacrificed one week after placement of the cylinder, it was found that the suspending gelatin was removed by cellular activity. Nine months later the remaining animals were sacrificed. Periodic X-rays were taken during the course of the experiment. After sacrifice, the mandible and associated tissues were histologically examined. The results of this study suggest that the silver granules in the muscles maintained their location during growth; the silver granules in the mandible moved forward with mandibular growth. “Slippage” appeared to occur external to the fibrous layer of the periosteum; the site of movement was revealed by the trail of the silver granules. The described method should prove of value in studying the growth interrelationships between bone, periosteum, and muscle.     

Light and electron microscopic study of omental milky spots in New Zealand Black mice, with special reference to the extramedullary hematopoiesis

Omental milky spots are especially large and numerous in New Zealand Black (NZB) mice, which are known to develop spontaneous autoimmune diseases. We investigated omental milky spots in NZB mice by light and electron microscopy. The milky spots were composed of abundant lymphocytes/plasma cells with macrophages, neutrophils, eosinophils, megakaryocytes, and various stromal cells. In addition, clustered neutrophils in various maturation stages with occasional mitotic figures were frequently present in the milky spots: apparent neutrophilic myelopoiesis was present. The presence of megakaryocytes was sporadic. Considering the giant size of megakaryocytes, their direct migration into the milky spots from the bone marrow or spleen seems improbable. Thus, the presence of megakaryocytes was interpreted as probable megakaryopoiesis. Erythroblasts were not contained in the milky spots. These findings seem to indicate that the milky spots in NZB mice represent a special type of lymphoid tissue with active neutrophilic myelopoiesis and probable megakaryopoiesis. Reticulum cells in the milky spots in NZB mice had well-developed dense bodies consisting of clustered parallel tubules that showed a hexagonal array. However, the biological significance of these cells remains unknown.     

Mental retardation, hypotonia, and generalized seizures associated with astrocytic “residual” bodies: An ultrastructural study

Two siblings suffering since birth from convulsions, hypotonia, and mental retardation are presented. In the older sibling (eight and one-half years of age) frontal lobe biopsy revealed abnormal cytosomes with lamellar profiles in astrocytes, macrophages, and to a lesser degree in neurons. Similar cytosomes have not yet been reported in cases of sphingolipidoses or in late infantile-juvenile amaurotic idiocy. These cytosomes stained intensely with silver proteinate, an ultrastructural cytochemical stain for carbohydrate moieties. In contrast, lipofuscin did not stain with silver proteinate. Multilamellar (crescentic curvilinear) cytosomes from a reported case of late infantile amaurotic idocy (Batten-Vogt-Spielmeyer disease) did not stain with silver proteinate. Abnormal cytosomes were not found in blood cells, liver, and peripheral nerve. In the younger sibling (14 months old) postmortem ultrastructural studies of cerebral tissue showed very few abnormal cytosomes. On the basis of the clinical and ultrastructural findings, we conclude that these two cases can be distinguished from those with multilamellar (crescentic-curvilinear) inclusions and from cases of the so-called "neuronal ceroid-lipofuscinosis" syndrome.     

“Apple‐peel” intestinal atresia,ocular anomalies,and microcephaly syndrome: Brain magnetic resonance imaging study

We report on a male child with “apple‐peel” atresia associated with microcephaly and ocular anomalies. To date, no magnetic resonance imagings have been published. We report on the fourth reported case with this phenotype, but the first to be studied by brain magnetic resonance imaging. © 2002 Wiley‐Liss, Inc.     

Liver units in three dimensions: I. organization of argyrophilic connective tissue skeleton in porcine Liver with particular reference to the “compound hepatic lobule”

Liver units were investigated in pig livers by means of histologic serial tracing, physical model building, and computer-aided three-dimensional imaging. Observations of the argyrophilic connective tissue skeleton were based mainly on the celloidin-embedded serial sections treated with silver impregnation. The parenchymal mass that clothed the initial segments of hepatic venous radicles was demarcated by fibrous septa which formed isolable units with two basic patterns: the simple hepatic lobule (SHL) and the compound hepatic lobule (CHL). Both lobule types presented regular limiting structures circumscribing each unit. Three-dimensional studies revealed that 25% of the lobules in a section belonged to the SHL type and 75% to the CHL type, the latter being predominant among the surface lobules. When considered in only two dimensions, however, the SHL-like lobules constituted the majority. Polygonal analysis disclosed that the pentagonal lobule was the most typical, instead of the “hexagonal” or “classic” lobule. The CHLs represented a multiaxial unit containing a system of venous tributaries in accordance with intralobular septation, whereas the SHLs were found with one axial vessel having a dendritic tendency at the incipient end; some SHLs were drained eccentrically by separate vessels into a sublobular vein. It was observed that, in dividing CHLs, whereas particular sinosoids were transformed into portal twigs, other sinusoids were changed into central venous tributaries. Fibrous deposition occurred along the septal-line sinusoids, bringing into view the septum-initiating plane. Fibroconnective tissue was supplied from the portal area and central (sublobular) adventitia, where portal triad structures and adventitial arterioles, respectively, were included. The findings of the present study facilitate the understanding of several characters of the lobules that have been reported previously, or occasionally postulated, such as the portal-central bridging tendency, the intralobular arterioles or ductules, the translobular artery or portal vein, the “portal-portal” or “portal-central” anastomoses, and the apposition of pericentral zone close to periportal zone. Based on differences in argyrophilia of sinusoidal reticulum, in proportion of lobule types, and in vasculature, the anatomic heterogeneity of liver unity was demonstrable in zonality, regionality, and locality. © 1991 WILEY-LISS, INC.     

Transformation of “Signet Ring Cell” Lymphoma to Typical Nodular, Poorly Differentiated Lymphocytic Lymphoma: Light Microscopic, Immunohistochemical and Electron Microscopic Observations

Malignant lymphoma with intracellular immunoglobulins giving a “signet ring” appearance to the lymphocytes is a recently described morphologic variant with specific ultrastructural and immunohistochemical characteristics. We report a case that had this distinctive morphology when initially biopsied but on subsequent biopsy 2 1/2 years later had the typical appearance of a poorly differentiated lymphocytic lymphoma without “signet ring” cells. The same monoclonal immunoglobulin class and light chain type was demonstrated in both biopsies using immunohistochemical techniques. Rare cells in the second biopsy showed the characteristic ultrastructural findings. These findings support the concept of a continuum of cell types in malignant lymphoma, with transformation toward a cell line lacking the peculiar characteristics resulting in this unique appearance.     

Immunocytochemical study of epidermal growth factor receptor, transforming growth factor alpha, and “squamous differentiation” in human endometrial carcinoma

The expression of epidermal growth factor receptor (EGFr) and transforming growth factor alpha (TGF-α) was compared with the presence of “squamous differentiation” (SD) visualized in various histotypes of endometrial carcinoma by using a panel of monoclonal antibodies. The results of the current study demonstrate that EGFr and TGF-α are present in routinely processed endometrial carcinoma. The highest positive EGFr and TGF-α expression was seen in the group of adenocarcinomas with SD. The more intense EGFr and TGF-α immunoreactivity was observed in “squamous” foci both in adenoacanthomas (AA) and in adenosquamous carcinomas (AS). These EGFr- and TGF-α-positive squamous areas prevalently displayed a “stratification-related” cytokeratin (CK) immunoprofile characterized by the expression of CKs 1, 4, 5, 10, 13, 14, and 16. No correlation was found between EGFr- and TGF-α-positive status and depth of myometrial invasion or surgical stage. These results clearly demonstrate that EGFr and TGF-α expression is related remarkably to endometrial carcinoma with “squamous” areas both morphologically and immunophenotypically. This specific association leads us to suggest that EGFr and TGF-α expression in endometrial carcinoma may be prevalently involved in the equilibrium of cell differentiation of the “squamous” foci commonly observed in this group of neoplasias.