An ultrastructural and morphometric study of bladder tumours (II)

Summary Bladder tissues from 3 groups of patients were examined, using the light and electron microscopes (LM and TEM). One group of patients had a history of well-differentiated papillary transitional cell carcinomas and specimens were taken from cystoscopically normal areas. In a second group frank papillary carcinoma was biopsied. Finally, patients with no history of urothelial tumours and a normal cystoscopic appearance were biopsied during investigations for various benign conditions and these served as controls.In tissues from the first two groups certain differences were seen when these were compared to the controls and the frequency of these was significant. Light microscopic examination of 0.5 toluidine blue stained sections revealed an increased number of immature, small dark cells in the superficial layer of the epithelium (P<0.001). Electron microscopic examination showed that in place of the characteristic asymmetric unit membrane of mature superficial cells, the surface was frequently covered with microvilli and the junctional complexes were often atypical. There was an increased number of abnormalities in the basal lamina (P<0.001).These features were seen in the absence of cystoscopic and light microscopic changes in three out of eight patients with a history of tumours. It is, therefore, suggested that these are the earliest detectable morphological abnormalities in the pre-neoplastic urothelium.     

An ultrastructural and morphometric study of bladder tumours (III)

Summary Quadrant biopsies were taken at cystoscopy from 12 male patients previously diagnosed on light microscopy as having flat carcinoma in situ (CIS) of the urinary bladder. There was also material available from 3 cystectomy specimens with widespread CIS associated with papillary or solid urothelial tumours.Sections of normal ureter from kidney transplant donors and biopsies from two patients investigated for non-malignant bladder conditions servered as controls.The biopsies from 4 patients were classified as mild dysplasia of the urothelium, while those from 11 patients were categorised as CIS.Biopsies categorised as mild dysplasia on light microscopy showed an increase in the number of cells with large nuclei and nucleoli when compared to controls. The number of desmosomes was significantly reduced compared to controls, while the frequency of abnormalities of the basal lamina was increased. These features were more pronounced in the CIS group.Biopsies from the CIS group could be divided into classical and large cell CIS, the latter showing a higher frequency of ultrastructural abnormalities than the classical type.The patients diagnosed as having CIS fell into two clinical categories, the early onset and the late onset group. The five patients in the former had been diagnosed as having CIS with or without urothelial tumours elsewhere within 3 months of presentation. In the remaining four patients CIS was observed after recurring episodes of papillary or solid tumours during the previous 9 months to 20 years.The biopsies of 3 out of 5 patients with early onset CIS had been classified large cell CIS, wheras only one patient out of 4 in the late onset group came into this category. An early appearance of CIS is thought to have a worse prognosis, and it is therefore suggested that large cell CIS is a more severe form of the disease.     

Parachordoma: An ultrastructural and immunohistochemical study

A case of parachordoma of the left calf in a 19-year-old Chinese female is reported. The tumour showed multinodular growth pattern and consisted of round or oval tumour cells with abundant eosinophilic cytoplasm and myxoid matrix. Tumour cells formed small nests and sometimes showed concentric arrangement. Physaliferous-like cells and undifferentiated spindle cells were occasionally observed among the cell nests. The myxoid matrix was positive for high-iron diamine stain, indicating the presence of chondroitin 4- and 6- sulphates and keratan sulphate. Ultrastructurally, well-developed rough endoplasmic reticulum, abundant intermediate filaments, microvillous cytoplasmic processes, pinocytic vesicles, and desmosome-like junctional structures were found. Tumour cells were positive for S-100 protein and vimentin, but negative for cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, and desmin. These results are consistent with the definition of parachordoma as a soft tissue neoplasm consisting of cells with histology and ultrastructure similar to those of chordoma cells but with immunohistochemistry similar to that of chondroid tumour cells.     

An ultrastructural and immunohistochemical study of central neurocytoma

A case of central neurocytoma was studied by electron microscopic and immunohistochemical methods. Immunohistochemical examinations showed the tumor cells to be positive for neuron-specific enolase, sporadically positive for synaptophysin, and negative for glial fibrillary acidic protein. The Ki-67 (MIB-1) positive index value for the tumor cells was a low 1.5%. Ultrastructurally, thin cytoplasmic processes of tumor cells showed differentiation to neuronal cells containing parallel bundles of microtubules and abortive synapses with dense core vesicles and/or clear vesicles. Microvessels composed of endothelial cells without fenestrations and tight junctions in the endothelial clefts appeared in fibrillary stromas as revealed by light microscopy. Neurosecretory granules in thin cell processes may have been secreted around microvessels.     

An ultrastructural study of malignant fibrous histiocytoma of the larynx

Malignant fibrous histiocytoma (MFH) of the vocal cord occurring in a 46-year-old male was studied immunohistochemically and ultrastructurally. The tumor consisted of the two main areas, pleomorphic and storiform. Immunohistochemical staining was strongly positive for α1-antitrypsin and α1-antichymotrypsin, and negative for desmin, keratin, myoglobin, actin, carcinoembryonic antigen, and S100 protein. Ultrastructurally, this MFH consisted of four different types of cells which were either fibroblast-like, histiocyte-like, myofibroblast-like, or with features of both the fibroblast and histiocyte types. Transition forms between the four types of cells were also found. This suggests that cells of MFH are derived from the same undifferentiated stem cells.     

Spontaneous atherosclerosis: An ultrastructural study in the White Carneau pigeon

Summary The atherosclerotic lesions, associated with the celiac intimal smooth muscle cushions, of four and five year old White Carneau pigeons were studied with the light and electron miscroscopes. Light microscopic examination of the spontaneous lesions demonstrated large intimal cushions composed of smooth muscle, abundant collagen, clusters of foam cells and cholesterol crystal clefts.Ultrastructural examination of the intimal atheroma revealed dilatations between apposing endothelial cells which contained a flocculent material, similar to that seen in the subendothelial space. The subendothelial compartment contained abundant collagen, extracellular lipid, vesiculated material and cell processes which contained a flocculent matrix and tubular-like elements. In addition, fibroblast-like interlaminar cells were often observed. Numerous intimal smooth muscle cells were seen which displayed varied morphology. Abundant foam cells were also present within the intimal atheromas.The presence of atherosclerotic lesions in preexisting intimal smooth muscle cushions suggests that hemodynamic factors may be important in the progression of these spontaneous lesions. Endothelial cell dilatations may provide an important route of transport for circulating elements which may accumulate within the subendothelial space. Morphologically, it appears that the smooth muscle cells undergo modification and may represent the precursors of foam cells in this species.Supported by a General Reserach Support Grant from NIH and The University of Texas     

An ultrastructural study of two cases of adrenal ganglioneuroma

Tissue samples of adrenal ganglioneuromas were obtained from two patients: 35- and 47-year-old males. Light microscopic studies showed that these tumors contained Schwann cells and ganglion cells. Electron microscopic examinations revealed numerous unmyelinated and myelinated axons surrounded by Schwann cells. The ganglion cells in the tumors had abundant organelles, such as well-developed cisternae of the rough endoplasmic reticulum, many profiles of the Golgi apparatus, mitochondria, lysosomes, microtubules and neurofilaments. Electron dense cored granules resembling catecholamine granules were present in the ganglion cell bodies and neural processes. These features resmebled those of normal sympathetic ganglion cells. It is concluded that adrenal ganglioneuroma originates from sympathetic ganglion tissue. This study was presented in part at the 26th Annual Meeting of the Clinical Electron Microscopy Society of Japan, Kochi, October 5–7, 1994.     

An ultrastructural study of nonfunctioning adrenocortical adenoma

Nonfunctioning adrenocortical adenomas obtained from 40 and 60-year-old males were examined by electron microscopy. Light microscopically, the tumors were shown to consist of clear cells and compact cells in both cases. However, compact cells predominated in the former case, and clear cells in the latter. Electron microscopy revealed that most of the cells in the former case had abundant organelles, including well-developed, smooth and rough endoplasmic reticulum, Golgi apparatus, and mitochondria with elaborate tubulovesicular cristae. The findings resembled those of adenomas with Cushing's syndrome. The latter case revealed a majority of cells with numerous, large lipid vacuoles, moderate amounts of smooth endoplasmic reticulum, Golgi apparatus, and mitochondria with sparse lamellar cristae resembling features of aldosteronoma. These ultrastructural findings suggest that even nonfunctioning adrenocortical adenomas, like functioning adrenocortical adenomas, have some possibility of producing adrenal hormones. This study was presented in part at the 25th Annual Meeting of the Clinical Electron Microscopy Society of Japan, Matsumoto, September 28–30, 1993.     

Neurofibromatous neuropathy: An ultrastructural study

Plexiform neurofibroma is pathognomonic of neurofibromatosis 1 (NF1). An NF1-associated peripheral neuropathy has been described in a small minority of NF1 patients but its histopathological features are poorly characterized. We report the case of a 46-year-old woman presenting with bilateral supraclavicular painful masses without other stigmata of NF1. MRI showed bilateral plexiform lesions extending from cervical roots to the elbows. Nerve conduction studies documented a sensory motor polyneuropathy. Morphometric analysis of sural nerve biopsy showed a preferential loss of large-caliber myelinated fibers with a g ratio of 0.515, and the presence of regeneration clusters. By electron microscopy, marked and diffuse endoneurial fibrosis with an altered relationship between Schwann cells (SC) and collagen fibrils was observed. Moreover both myelinating and non-myelinating SC were characterized by the presence of various cell degradation products. These changes suggest that, in neurofibromatous neuropathy, a widespread axonal atrophy and degeneration take place independently on the presence of tumoral infiltration, possibly due to an impairment in SC-axon cross talk. In this case, the coexistence of plexiform neurofibromas with a peripheral neuropathy strongly suggests a diagnosis of NF1 even without fulfillment of clinical criteria. We propose that in the presence of plexiform neurofibromas, electrophysiological studies should be performed also in asymptomatic patients, in order to detect the existence of a subclinical neuropathy.     

An ultrastructural morphometric analysis on ultrathin epon and ultrathin cryosections of normal human gastric tissue and human gastric cancer

Summary An ultrastructural morphometric study on ultrathin epon, and cryosections of normal and neoplastic, adult, human, gastric tissue is presented. The data show a characteristic numerical pattern for the different neoplastic types of gastric tissues.     

An ultrastructural and immunohistochemical study of cutaneous metastasis of biliary system carcinoma

An 81-year-old Japanese man noticed red papules and subcutaneous tumors on his face and trunk about 2 months before entering our clinic. He had been suffering from biliary system cancer for about one year.Light microscopic findings: Tumor cells, which formed various-sized glands lined by columnar cells, were observed in the dermis and subcutaneous tissue.Electron microscopic findings: In tumor cells, intracytoplasmic lumina lined with microvilli were observed. Cell organelles, such as mitochondria and rough-surfaced endoplasmic reticulum, were relatively well-developed. From these findings, it seems that the characteristics of these tumor cells resemble those of the biliary system.     

An ultrastructural study of meconium corpuscles in human foetal colon

Summary In human foetal colon meconium corpuscles were observed in the colonic epithelium during the stage of secondary lumina development and enlargement.Transmission electron microscopy of these specimens revealed inclusion bodies in the superficial and deeper layers of the epithelium. Many of the membrane-bounded inclusion bodies contained well-preserved organelles and some inclusions contained nuclear fragments. There was evidence of nuclear fragmentation with condensed chromatin arranged in crescentic caps. The ultrastructural observations are typical of apoptosis, a mode of cell death first described in 1972 by Kerr and colleagues.Thus, meconium corpuscles are apoptotic bodies found as a result of the deletion of healthy normal cells during the reshaping and development of organs.     

An ultrastructural study of subungual exostosis, with special reference to intranuclear inclusions

A 12-year-old Japanese boy noticed a red nodule on the distal portion of his right great toe about 2 months before entering our clinic. There was evidence of traumatic injury and infection before the appearance of the nodule. Histological examination showed the subcutaneous localization of bony spicules lined by osteoblasts. Haversian canals, which contained blood vessels and connective tissue, were also seen. Electron microscopic examination revealed normal bone structure, but, interestingly, mesenchymal cells that were localized around the tumor had intranuclear inclusions composed of filamentous bundles. From these findings, this case was diagnosed as subungual exostosis. It is suggested that the appearance of intranuclear inclusions, reported here for the first time, is related to the pathogenesis of subungual exostosis.This study was presented at the 28th annual meeting of the Clinical Electron Microscopy Society of Japan, Osaka, October 17–19, 1996     

Cellular composition of milky spots in the human greater omentum: An immunochemical and ultrastructural study

Background: Milky spots in the greater omentum of some animals are well organized perivascular infiltrated of leucocytes, and are considered to have characteristics of secondary lymphoid tissue. To determine whether milky spots in the human greater omentum can also be regarded as secondary lymphoid tissue, we studied milky spots in an unstimulated state. Methods: Patients were selected on the basis of absence of disease in the peritoneal cavity that might influence the state of the milky spots. Using monoclonel antibodies aganist macrophages, B-lymphocytes and T-lymphocytes, and immunoperoxidase labeling, the number of these cells and their location in milky spots were studied by light microscopy. However, the stromal components of the greater omentum, especially those within the milky spots, were studied by electron microscopy. Results: Milky spots in the human greater omentum are relatively uniform vascularized accumulations of mononuclear cells comprising macrophages (67.9% ± 9.4, mean ± standard deviation), B-cells (10.1% ± 3.4), T-cells (10.2% ± 3.7), and mast cells. However, no special B-cells and T-cell areas could be distinguished. On the ultrastructural level it was demonstrated that macrophages are present in different stages of maturation and can enter or leave the milky spots. Furthermore, no cells characteristic of secondary lymphoid organs, such as interdigitating cells or follicular dendritic cells, were seen. Conclusions: These data indicate that unstimulated milky spots in the human greater omentum are to a great extent just a preformed specific accumulation of primarily macrophages within the stroma of the greater omentum, and therefore, cannot be regarded as true secondary lymphoid tissue. Milky spots could serve as a gateway for, as well as a provider of pertioneal macrophages when the intra-abdominal status so requires. Finally, the data from this study are compard with the data of other studies of human milky spots and those in animals. © 1995 Wiley-Liss, Inc.     

An ultrastructural study of pemphigoid vegetans, characterizing the possible mechanism of vegetation

Ultrastructural changes in the skin lesions of pemphigoid vegetans were observed by transmission electron microscopy. Two significant changes were recognized at the vegetating site: (1) The basal lamina was sometimes interrupted and detached from the basal cells, protruding into the dermis to form folds. In the basal cells, hemidesmosomes were not decreased in number but tonofilament bundles were fewer than normal. Occasionally, basal cell processes extended beyond the basal lamina through its gap. These features resembled the epidermal growth factor-induced morphological changes of cultured skin. It was suspected that the abnormal attachment of the basal lamina to the basal cell was associated with keratinocyte proliferation. (2) Mast cells were encountered in the epidermis abutting on the basal lamina. It is uncommon to find mast cells in the epidermis. Mast cells in the epidermis were reported at the erythematous regions which were adjacent to the bullae of bullous pemphigoid, and were thought to have an important role in forming blisters. It was suggested that early changes in blister formation occur at the vegetating site.This study was presented at the 20th annual meeting of the Clinical Electron Microscopy Society of Japan, Fukuoka, September 1, 1988, at the 21st annual meeting of the Clinical Electron Microscopy Society of Japan, Kobe, September 22, 1989, and at the 23rd annual meeting of the Clinical Electron Microscopy Society of Japan, Toyama, September 14, 1991.     

Morphometric and ultrastructural analysis of tramadol effects on epididymis: an experimental study

The effect of tramadol addiction on epididymal structure was not investigated before. Therefore, this experimental study was carried out to investigate the effect of chronic tramadol use on the epididymal structure using light and electron microscopies. Thirty adult Wister Albino male rats were divided into two groups: control group (five rats) and tramadol-treated group (25 rats), which was further subdivided into five subgroups that received tramadol orally at 4.5, 9, 45, 90, and 135 mg/kg/day, respectively, for 18 weeks. Epididymal tissues were dissected and processed for histopathological examination. Morphometric analysis showed significantly reduced mean values of epididymal ducts’ diameters and epithelial height in the tramadol-treated group compared with the control group. Light microscopic examination revealed degeneration and necrosis of epididymal cells in the tramadol-treated group. Electron microscopic (EM) examination showed ultrastructure alterations in a dose-dependent manner. In conclusion, tramadol can adversely affect all epididymal cells, which subsequently deteriorate epididymal function and may affect sperm maturation, leading to subfertility.     

An ultrastructural study on anterior cruciate ligament reconstruction using autogenous patellar tendon grafts in dogs

An ultrastructural study was undertaken concerning morphological changes within the autografted patellar tendon (PT) after being transplanted to the anterior cruciate ligament (ACL) in mongrel dogs. After 4 weeks, the arrangements of both large and small collagen fibrils in the PT graft became disordered, and the number of inflammatory cells increased. However, the same PT grafts revealed postsurgical signs of newly-produced collagen fibrils around activated fibroblasts at 12 to 24 weeks. At 52 weeks after the transplantation, small collagen fibrils increased in both number and density, showing a remarkable morphological similarity to the collagen fibrils of normal ACL. These data indicate that the characteristics of the PT graft eventually resemble those of a normal ACL. This paper was presented in part at the Combined Meeting of the Orthopedic Research Societies of the USA, Japan and Canada in Banff, Alberta, Canada, October, 1991.     

An ultrastructural morphometric study of developing rat substantia gelatinosa

A morphometric analysis has been done on developing rat substantia gelatinosa of the lower cervical and upper thoracic levels of the spinal cord starting on the 15th day of gestation. The following parameters were measured: cell body diameter, cytoplasmic/nuclear areas, synaptic density, synaptic type and vesicle morphology of the presynaptic terminal in axodendritic synapses. Cell body size and cytoplasmic/nuclear areas of gelatinosal cells increase until the 15th day postnatally and then decrease somewhat to the adult values. The first synapses are seen on gestation day 17. Synaptic density increases linearly until the third day postnatally. Axodendritic synapses are most common throughout development and in the adult, while the proportion of axoaxonic synapses increases and axosomatic synapses decreases during development. Most of the terminals in axodendritic synapses contain clear-spherical vesicles but the occurrence of clear-flat vesicles and dense-cored vesicles in the terminals increases during development. It appears that these morphological parameters provide a stable index of development in the substantia gelatinosa which can be correlated with functional development of the area. Hopefully, they will provide a means to assess subtle anomalies induced by nonteratogenic drugs or other environmental changes.     

An ultrastructural study of glomeruli associated with vomeronasal organs transplanted into the rat CNS

Rat neonate vomeronasal organs were transplanted into the parietal cortex of littermates to examine their survival and the behavior of axon growth into the surrounding host brain parenchyma. After survival times of 10–100 days the brains were processed for ultrastructural examination. The transplanted vomeronasal organs (VNO) formed several vesicles lined with a sensory epithelium. From these sensory epithelia, VNO neurons leave the epithelium and enter the host brain. Transplant neurons grew axons that fasciculated into bundles surrounded by sheath cell processes and formed one or more fiber plexuses containing distinct globose or spherical-shaped glomeralar-like structures. The glomeruli consisted of nerve terminals between which existed asymmetric synaptic contacts. Rarely did we observe clear reciprocal synapses. The glomeruli also contained terminals that showed signs of degeneration, such as increased density of the terminals, clumping of mitochondria and multivesicular bodies. The glomeruli were not partitioned or subdivided by glial septa; however, glial profiles were interspersed among the sensory terminals. Transplant glomeruli also lacked periglomerular cells and had no definitive glial envelope. These results suggest that glomerular formation is not dependent on dendrite contribution of second order neurons or glial support, but rather on a complementary population of receptor neurons.     

An electron microscopic study of glomerular lesions in hereditary nephrotic mice (ICGN strain)

Summary Glomerular lesions in hereditary nephrotic mice (ICGN strain) were investigated by electron microscopy. The glomeruli of unaffected animals, which appeared normal by light microscopy, had developed an ultrastructural change in the glomerular capillary basement membrane (GCBM). There was a partial thickening of the GCBM with bilaminar splitting of the lamina densa and an electron-dense fibrillar material exhibiting cross-striations. In affected animals, light microscopy revealed a marked thickening of GCBM and an increase of mesangial matrix without cellular proliferaton. By electron microscopy, multilaminar splitting of the lamina densa in the thickened GCBMs and fusion of the epithelial foot processes were observed. In some severely affected animals, immune complex deposition was found in GCBM, but little if any was observed in other animals. In the end, the glomeruli were globally sclerosed. Our findings suggest that initial structural abnormalities in GCBM may play an important role in the onset and development of the disease, though subsequent events such as immune complex deposition would modify the disease.