The origin and fate of microbodies in the fat body of an insect.

The structure and life history of insect microbodies are described during the development of the fat body from the 4th to 5th larval molt through the 5th to pupal molt. The mature microbodies are flattened spheres about 1.1 x 0.9 micro, with a depression on one side where a dense mass connects the limiting membrane to the core of coiled tubules. They contain catalase and urate oxidase. The precise synchrony of development of insect cells during the molt/intermolt cycle makes it easy to study the life history of particular organelles. Phases of growth are correlated with the hormonal milieu. Mature 4th stage microbodies decrease in size before ecdysis to the 5th stage when they atrophy at the same time as the new 5th stage generation arises. The 5th stage microbodies form as diverticula of the RER and, grow while confronted by RER cisternae. The mature microbodies decrease in size when the fat body engages in massive larval syntheses. At the end of the 5th larval stage, the microbodies are invested by isolation membranes and destroyed before pupation. There are thus two mechanisms for microbody destruction: atrophy of the 4th stage organelles and isolation with autophagy at the end of the 5th stage.

Characterization of two cell lines with distinct phenotypes and genotypes established from a patient with renal cell carcinoma.

Two human renal carcinoma cell lines have been established from the same patient. One cell line (CCF-RC1) was obtained from the primary tumor and the second (CCF-RC2) was established from cells of the renal vein effluent of the perfused tumorous kidney. Although they were established from the same patient, the cell lines differed in certain biological properties. They have been passaged up to 50 times in vitro for about two years. Each has an epithelial morphology and exhibits mutilayering. Cell cycle time of CCF-RC1 and CCF-RC2 was 34 and 36 h, respectively. They exhibited anchorage independent growth, and the plating efficiency of CCF-RC2 in soft agar was higher than that of CCF-RC1. Both lines induced tumors in nude mice at the site of s.c. injection closely resembling the original tumor in histological examination. Electron microscopic features of both tumors in nude mice were consistent with epithelial origin. Doubling time of CCF-RC1 and CCF-RC2 in nude mice was 11 and 12 days, respectively. CCF-RC1 and CCF-RC2 have hypotetraploid karyotype and modal numbers of 83 and 73, presenting two and three marker chromosomes, respectively. Immunocytology with commercial monoclonal antibodies against renal carcinoma (URO-3) and cytokeratin (Mac 6) showed positive reactions with both lines, suggesting that these cell lines derived from renal epithelium. A murine monoclonal antibody (2E11) was generated against CCF-RC2 by the hybridoma technique; 2E11 reacted with CCF-RC2, but not with CCF-RC1. These cell lines may provide a useful model for the study of tumor heterogeneity and its relationship to metastasis.

Erythropoietin secretion by isolated rat Kupffer cells.

Hepatic parenchymal and Kupffer cells were isolated from regenerating rat liver and maintained in primary culture in an attempt to identify the cell type responsible for extrarenal erythropoietin (Ep) production. Conditioned media from Kupffer cell cultures were shown to contain Ep. Kupffer cells were cultured in the presence and absence of serum, but only cultures with serum contained bioactive Ep. The addition of latex beads to Kupffer cell cultures increased the amount of Ep secreted. Parenchymal-cell-conditioned media were negative for Ep activity. Isolated liver macrophages might be useful in vitro for the study of Ep elaboration.

Sclerosing vasculopathy of the central nervous system in nonelderly demented patients.

Three nonelderly patients without hypertension whose clinical and radiologic features otherwise resembled Binswanger's subcortical arteriosclerotic encephalopathy underwent biopsy of the hyperintense periventricular lesions seen on magnetic resonance imaging. The pathologic findings of the periventricular lesions consisted of gliosis with mild rarefaction and edema of the white matter. All patients had a sclerosing vasculopathy of unknown cause, which involved numerous small vessels within the periventricular lesions. The vessels stained negatively for amyloid, amyloid precursors, desmin, vimentin, keratin, immunoglobulin, and complement. On electron microscopy, small arteries, arterioles, venules, and capillaries were characterized by swollen astrocytic foot processes surrounding the vessels; dense, perivascular collagen packing; crystalline arrays of filaments within basement membrane; giant lipid-laden lysosomes within perivascular cells; and narrowing of the vascular lumina. Similar changes were not seen in a control group of 19 patients. The pathologic features of the vessels in these cases are distinct from the vasculopathy associated with Binswanger's subcortical arteriosclerotic encephalopathy. We suggest that a spectrum of vasculopathies may be associated with dementia and periventricular hyperintense lesions on magnetic resonance imaging.

Membranous glomerulopathy associated with captopril therapy.

Two cases of nephrotic syndrome and biopsy-proved membranous glomerulopathy (membranous glomerulonephritis) were encountered during captopril treatment of 53 hypertensive subjects in our institution. Both patients had impaired renal function before treatment and were treated with 600 mg per day. Discontinuation of captopril led to transient partial remission of proteinuria but was followed by a recurrent, fluctuating course over one year later. Repeat biopsies, eight and 12 months after discontinuation of the drug, demonstrated persistent subepithelial deposits in the glomerular basement membrane. There has been a decline in glomerular filtration rate since discontinuation of the drug, apparently due to arterionephrosclerosis. These studies suggest that glomerular basement membrane deposits in captopril-associated membranous glomerulonephritis are not readily reversible and may be associated with persistent proteinuria, contrary to some previous reports.

Light chain nephropathy.

In 13 specimens of renal tissue from 11 patients, deposits of monoclonal immunoglobulin light chains and continuous granular electron-dense material within tubular basement membranes and in association with the glomerular basement membrane were identified. All but one patient were men n the fifth to seventh decades of life, and each presented with azotemia and features of glomerular rather than tubulointerstitial disease. Osteolytic bone lesions occurred in only three patients, and a bone marrow plasmacytosis greater than 30 percent consistent with plasma cell myeloma was identified in only four patients. Light chain distribution in the nephron was confirmed with immunoelectron microscopy and was not associated with deposition of other serum proteins such as immunoglobulin heavy chains, complement, transferrin, alpha 2 macroglobulin and albumin. The electron dense deposits differed in distribution and character from those associated with membranoproliferative glomerulonephritis type II (dense deposit disease), amyloidosis, cryoglobulinemia, macroglobulinemia and benign monoclonal gammopathy. Serum from six of these patients did not bind to normal human or rat renal parenchyma in vitro. Kappa light chain nephropathy was characterized by predominant linear tubular basement membrane kappa deposits, and nodular mesangial and linear glomerular basement membrane kappa immunostaining. Lambda light chain nephropathy was characterized by linear lambda glomerular basement membrane and tubular basement membrane immunostaining. Manifestations of glomerular dysfunction dominated the clinical presentation of light chain nephropathy, and most patients did not have typical features of multiple myeloma. The diagnosis was predicated upon thorough immmunohistologic assessment of renal biopsy material.

Meningeal myofibroblastoma.

Myofibroblastoma is a recently described benign mesenchymal tumor. Only one case has been reported previously in the CNS. We report a second case of myofibroblastoma arising in the meninges in a 70-year-old woman who presented with visual changes. The histologic appearance was characterized by alternating areas of spindled and rounded cells separated by collagen and amianthoid fibers. Immunostaining demonstrated strong vimentin and focal smooth-muscle actin positivity; staining for epithelial membrane antigen, cytokeratin, S-100, desmin, myosin, glial fibrillary acidic protein, and factor VIII-related antigen was negative. Ultrastructurally, the myofibroblasts had features of both smooth-muscle cells and fibroblasts. Differentiating the benign myofibroblastoma from more aggressive meningeal sarcomas and meningeal meningiomas is important. The tumor most likely arises from myofibroblasts that probably reside in the meninges.

Adrenal carcinosarcoma presenting in a woman with clinical signs of virilization. A case report with immunohistochemical and ultrastructural findings.

An adrenal carcinosarcoma is reported in a 29-year-old female presenting with clinical signs of virilization. This is the first reported case of a functioning adrenal carcinosarcoma in the English language literature. The tumor measured 12.5 cm in greatest dimension, weighed 610 g, and consisted of large areas of typical adrenal cortical carcinoma that was, however, interspersed with multiple foci of sarcoma. Rhabdomyosarcomatous elements were identified and confirmed both immunohistochemically and ultrastructurally. After radical resection, the patient received adjuvant mitotane therapy but developed rapid local and metastatic recurrence. Systemic chemotherapy was unsuccessful, and the patient died 8 months after surgery.

Mineral-associated hepatic injury: a report of seven cases with X-ray microanalysis.

The patterns of hepatic injury associated with various minerals were studied in seven patients. The subjects included one patient who was a sandblaster (silica by inhalation), one patient who was a dental laboratory technician (silica and chromium-cobalt alloy by inhalation), one patient with inhalational talcum powder abuse, and four chronic intravenous (IV) drug abusers (talc by IV injection). In all cases, the liver was examined by light and polarizing microscopy, and by scanning electron microscopy with energy-dispersive x-ray microanalysis. In the two patients with silica exposure, silica-containing sclerohyaline nodules were diffusely present in portal tracts and lobules. Both chromium-cobalt alloy and silica were present in the dental technician. In contrast, in all cases of talc exposure, aggregates of talc-laden macrophages were present in portal and centrilobular areas. Three IV drug abusers and the talcum powder abuser had histologic evidence of chronic hepatitis, most probably of viral etiology. We conclude that mineral type plays an important role in the pathogenesis and fibrogenesis of hepatic lesions. Compared with silica, talc primarily elicits a macrophage response without granuloma formation or fibrosis. Hepatic silicosis is a rare complication in dental laboratory technicians, and chromium-cobalt alloy may contribute to hepatic injury and fibrosis in this setting.

Ultrastructural study of tissue and peripheral blood neutrophils in human renal allograft recipients. A clinicopathological description of an unusual abnormality discovered in three cases.

This report describes an unusual striking ultrastructural abnormality of neutrophils in three human renal allograft recipients. The abnormal neutrophils showed the presence of numerous elongated nuclear and cytoplasmic inclusions measuring up to 1.6 by 0.1 mu in greatest dimensions. Although the definite nature and functional significance of these inclusions are unknown, we suggest that they may represent an acquired neutrophil disorder. The three patients had serious infectious complications.

Comparison of alternative chromogens for renal immunohistochemistry.

Renal immunomicroscopy using enzyme labeled reagents has been shown to be a reliable method for the identification of immunoglobulins and complement in the routine evaluation of glomerular disease. However, the potential carcinogenicity of benzidine derivatives used in the procedure represents a major disadvantage of the technique. With a series of 55 renal biopsy specimens evaluated by light microscopy, immunofluorescence, and electron microscopy from patients with a variety of renal diseases, a study was done comparing aminoethylcarbazole and the Hanker-Yates reagent (p-phenylenediamine and pyrocatechol), chromogens chemically unrelated to benzidine. Aminoethylcarbazole was not suitable for renal immunomicroscopy, since in cases of antiglomerular basement membrane disease the color reaction product was finely granular at high magnification. Specimens immunostained with the Hanker-Yates reagent yielded permanent water insoluble reaction products and immunomicroscopic patterns identical to the results observed with immunofluorescence in all cases. To our knowledge, no carcinogenic properties have been identified for p-phenylenediamine or pyrocatechol. The Hanker-Yates reagent may be used routinely for renal enzyme immunomicroscopic studies with no currently identified carcinogenic hazard to laboratory personnel.

Ultrastructural examination of the axillary skin biopsy in the diagnosis of metabolic diseases.

There is little information in the literature regarding the usefulness of ultrastructural examination of axillary skin biopsies in the evaluation of metabolic diseases. This is a retrospective clinicopathologic review of 143 patients who underwent axillary skin biopsies as part of evaluations for metabolic disease. Twenty-three (16%) had abnormalities, classified as follows: mitochondrial (n = 12), lysosomal (n = 6), increased glycogen (n = 3), nonspecific cytoplasmic inclusions (n = 2), ceroid lipofuscinosis (n = 1), and intradermal giant cells containing vacuoles and tubular inclusions (n = 1). Muscle biopsies were performed in 13 of the 23 patients; 11 showed abnormalities, including those related to mitochondria (n = 4) and other nonspecific changes (n = 7). Two patients underwent postmortem examination. Follow-up was available in 21 patients. A clinical or biochemical diagnosis was reached in 11 patients: metachromatic leukodystrophy (n = 2), electron transport chain abnormalities (n = 2), glutaric aciduria type II (n = 1), Unverricht disease (n = 1), Lennox-Gastaut syndrome (n = 1), ketotic hypoglycemia of childhood (n = 1), probable Leigh disease (n = 1), 5-methyl tetrahydrofolate homocystine methyltransferase deficiency (n = 1), and pyruvate dehydrogenase deficiency (n = 1). Of the 120 patients with negative skin biopsy results, 29 had abnormal findings on muscle (n = 27), nerve (n = 7), or brain (n = 3) biopsies. One patient had an abnormal heart biopsy result, and 3 patients underwent postmortem examinations. Follow-up was obtained in 27 of 29 patients. Diagnoses were achieved in 15 patients: electron transport chain abnormalities (n = 5), cortical dysplasia (n = 3), myoclonic epilepsy (n = 1), leukodystrophy (n = 2), Pallister-Killian mosaic syndrome (n = 1), Rett syndrome (n = 1), Landau-Kleffner syndrome (n = 1), and mitochondrial cardiomyopathy (n = 1). In conclusion, axillary skin biopsy is helpful in the evaluation of some causes of metabolic disease, but often the findings are nonspecific. A negative biopsy result does not rule out the possibility of metabolic disease, but a positive result may provide direction for further evaluation.

Chronic glomerular microangiopathy complicating metastatic carcinoma.

Six cases of metastatic carcinoma associated with chronic glomerular microangiopathy and renal failure are reported. All had prominent subendothelial lucent zones and double-contoured glomerular basement membranes. There was no immunohistologic or ultrastructural evidence for immune complex entrapment in glomeruli. By immunohistology, material antigenically related to fibrin or fibrinogen was identified in glomerular basement membranes despite a paucity of typical fibrillar fibrin. Four patients received mitomycin C before the onset of renal disease, and one patient received chemotherapy other than mitomycin C before development of renal failure. One patient had no chemotherapy but was given radiotherapy, which did not include the kidneys in the irradiated field. These six cases emphasize the diverse pathophysiologic mechanisms by which glomerular microangiopathy may arise in metastatic carcinoma.

Activation of intravascular macrophages within myocardial small vessels is a feature of acute vascular rejection in human heart transplants.

BACKGROUND: We investigated the pathogenesis of acute vascular rejection by performing immunofluorescent screening on frozen sections for C1q, C3c, and immunoglobulin M in endomyocardial biopsy specimens from all new heart transplants. METHODS: Immunofluorescence for C4c, C5, immunoglobulin G, and immunoglobulin A was performed on all positive endomyocardial biopsy specimens. Twenty-eight positive endomyocardial biopsy specimens from six patients were identified, and 22 of those were studied with transmission electron microscopy. RESULTS: Endothelial hyperplasia and myocyte necrosis were prominent in the five female patients with positive immunofluorescence. In addition, macrophages with ultrastructural cytologic features of activation were seen filling capillaries and venules in intimate contact with endothelium and exiting those vessels. Activated macrophages were large cells with abundant cytoplasm and ruffled borders and contained numerous lysosomes, rough endoplasmic reticulum, and mitochondria. Intravascular activated macrophages were identified in five of six patients with positive immunofluorescence but were not seen in any of the endomyocardial biopsy specimens with negative immunofluorescence, including multiple examples of moderate (grades 2 to 3B) and severe (grade 4) acute cellular rejection. In the five female patients with activated macrophages, acute vascular rejection recurred multiple times with one fatality. Review of the files showed three additional, similar cases. The one male patient with positive immunofluorescence but without activated macrophages had only a single episode of acute vascular rejection. CONCLUSIONS: Complement and antibodies can activate macrophages, so this finding is not surprising. To the best of our knowledge, this is the first report of the intravascular activation of macrophages, and the first association of this process with acute vascular rejection. Activated macrophages may contribute to myocyte necrosis in acute vascular rejection by compromising blood flow in small vessels.

Comparison of myocardial cell injury in acute cellular rejection versus acute vascular rejection in cyclosporine-treated heart transplants.

BACKGROUND: Myocyte necrosis has been cited as a key feature in the diagnosis and classification of both moderate and severe acute cellular rejection (International Society for Heart and Lung Transplantation grades 3A to 4). However, our previous work suggests that myocyte necrosis is not a typical feature of cellular rejection. METHODS: To clarify this point and to elucidate differences between cellular rejection and acute vascular rejection, we compared the light and electron microscopic features of 35 consecutive endomyocardial biopsy specimens from six patients with acute vascular rejection diagnosed with positive immunofluorescence, 12 consecutive endomyocardial biopsy specimens from three patients with mixed acute vascular rejection and cellular rejection, and 435 endomyocardial biopsy specimens of International Society for Heart and Lung Transplantation grades 2 to 4 cellular rejection. RESULTS: Endomyocardial biopsy specimens from eight of nine patients with acute vascular rejection and mixed acute vascular rejection/cellular rejection exhibited classic myocyte necrosis as the typical form of myocardial cell injury. Myocyte necrosis was characterized by lysis of the sarcolemma, marked swelling of mitochondria, and intramitochondrial flocculent densities. In contrast, the typical form of myocardial cell injury in cellular rejection was reversible. Reversible cellular rejection was characterized by extensive loss of myosin filaments and Z-lines with subsarcolemmal and intracytoplasmic accumulation of Z-band material. Cell swelling, mitochondrial swelling, intramitochondrial densities, and lysis of sarcolemma were not observed. CONCLUSIONS: We conclude that myocyte necrosis is a characteristic feature of acute vascular rejection, whereas reversible myocardial cell injury is characteristic of cellular rejection, including grade 4. Myocyte necrosis is not a feature of cellular rejection. The presence of true myocyte necrosis in endomyocardial biopsy specimens from cyclosporine-treated heart transplants implicates some process other than cellular rejection. Processes producing myocyte necrosis include acute vascular rejection, peritransplantation ischemia, and accelerated atherosclerosis.

Cutaneous malignant melanoma metastatic to the vitreous.

A 38-year-old man previously had a cutaneous malignant melanoma excised from his right shoulder. He presented to our clinic with neovascular glaucoma, corneal edema, large pigmented keratic precipitates, anterior chamber reaction, and pigmented aggregates in the vitreous of his left eye. There were no other ocular findings. Subsequent enucleation was performed and the globe was studied histopathologically. Special stains and electron microscopy showed the presence of both macrophages and malignant melanin-producing cells within the vitreous. The diagnosis of cutaneous malignant melanoma metastatic to the vitreous was made based on these findings. This is a rarely reported clinical entity, for which a high index of suspicion should be maintained.

Ultrastructural analysis of small cell carcinomas of the ovary.

Small cell carcinoma (SCC) of the ovary is a rare tumor of young females, frequently associated with hypercalcemia. Eight SCC specimens from six patients, including four with hypercalcemia, were examined by electron microscopy to determine if certain ultrastructural features were consistently present to be of diagnostic value and to assess histogenesis. Each tumor had epithelial features with frequent desmosome-like junctions and partial investment with basal lamina. The most consistent and prominent finding was abundant dilated rough endoplasmic reticulum (RER) forming large vesicles filled with homogeneous granular (proteinaceous) material of variable density. RER vesicles were identified in all six primary tumors and in both recurrent and metastatic lesions. Dense-core granules of neurosecretory type were absent. None showed immunohistochemical reactivity for parathyroid hormone. The ultrastructural features of SCC are sufficiently constant to be of diagnostic value in the differential diagnosis of ovarian neoplasms. Histogenesis remains obscure.

Diagnostic yield muscle biopsy in patients with clinical evidence of mitochondrial cytopathy.

We retrospectively reviewed 118 muscle biopsy specimens from 113 patients with clinical and/or biochemical evidence of mitochondrial cytopathy. Light microscopic evaluation revealed histologic abnormalities in 65 specimens. The most common histologic findings included angular atrophic esterase-positive muscle fibers, type II muscle atrophy, regenerating muscle fibers, and scattered cytochrome-oxidase deficient fibers. Ragged red fibers were noted in 3 specimens on a Gomori trichrome stain. Electron microscopic evaluation was performed in 113 muscle specimens, and in 34, no abnormalities were identified. Increased numbers of mitochondria, particularly in the subsarcolemmal region, were identified in 54 specimens. Increased mitochondrial size was seen in 8 specimens and paracrystalline mitochondrial inclusions in 3. Other ultrastructural findings included focally increased glycogen deposition, focal Z-band streaming, and focally increased lipid accumulation. For 39 cases, concomitant skin biopsy specimens were available; abnormalities were identified by electron microscopy in 12. The majority of biopsy specimens demonstrated some light or electron microscopic abnormality. Specific histologic findings suggestive of mitochondrial abnormalities (partial cytochrome oxidase deficiency, ragged red fibers) were noted in a minority of cases. Ultrastructural evidence of mitochondrial abnormalities was noted in the majority of cases.

Hepatic giant cell carcinoma. An ultrastructural and immunohistochemical study.

Hepatocellular carcinoma with osteoclast-like giant cells (hepatic giant cell carcinoma [HGCC]) is a rare entity, with only three cases reported. The tumor is histologically similar to giant cell tumor (GCT) of bone, and the origin of the multinucleated giant cells and mononuclear stromal cells has not been determined. The purpose of this report is to present a case of this rare tumor and compare its ultrastructural and immunohistochemical features with those of a conventional GCT of bone. Histologically, the HGCC consists of sheets of osteoclast-like giant cells with a background of mononuclear cells. The giant cells lack the pleomorphism seen in hepatocellular carcinomas with anaplastic giant cells. At the light microscopic level, most of this tumor was nearly identical to a GCT of bone, but several microscopic fields (less than 5% of the tumor) had the histologic appearance of a "usual" hepatocellular carcinoma. The hepatic tumor was negative for HAM 56, epithelial cytokeratins, muramidase, and alpha-1-antitrypsin, with only focal positivity for chymotrypsin in mononuclear and giant cells. The GCT was strongly positive for alpha-1-antitrypsin and chymotrypsin in both the mononuclear and giant cells and showed focal, weak staining for AE1 and AE3 in the mononuclear stromal cells. Ultrastructurally, both mononuclear and giant cells of the HGCC showed features typical of hepatocellular carcinoma. Although the patient presented in this report died, the pattern of growth was different from most hepatocellular carcinomas. The overall histologic features of this tumor are distinctive and appear to justify separating this variant from other types of hepatocellular carcinoma.

Characterization of blood mononuclear and cultured cells in hairy cell leukemia.

The nature of neoplastic cells in hairy cell leukemia (HCL) is still controversial. Most reports favor derivation from B cells, but some have suggested origin from monocytes/histiocytes, T cells, or even a hybrid Ig-bearing lymphocyte with phagocytic activity. We established a new cell line from peripheral blood of a patient with typical HCL. The morphologic, immunocytochemical, and functional properties of the new cell line were identical with the patient's original HC. Both cell types demonstrated the irregular, fine cytoplasmic projections characteristic of HC, were weakly phagocytic, markedly positive for tartrate-resistant acid phosphatase, and had variable nonspecific esterase reactivity. Low percentages of EAC-rosetting cells were found (8% original specimen and 6% cultured cells) and a minute amount of IgG, IgA, and IgM were synthesized by the new cell line. A small proportion of cells (13% original specimen and 12% cultured cells) bore SIg when stained with F(ab)2-fragment polyvalent antiserum. Our observations indicated that HC were a slowly proliferating cell population with immunochemical and functional characteristics of both B and monocyte/histiocytic cells.