Pachydermoperiostosis. An ultrastructural study

BACKGROUND: Pachydermoperiostosis (PDP) is a rare genetically determined disease belonging to the group of hypertrophic osteoarthropathies. Its aetiopathogenesis remains unclear. Most hypotheses favour an exogenous stimulation of fibroblasts. METHODS: A clinically typical patient with PDP was studied by electron microscopy with particular reference to the dermis and its cellular constituents. Fibroblasts from involved skin were cultured and studied in comparison with control cells. RESULTS: Remarkable modifications of the structure of the dermis were observed, encompassing irregular caliber of collagen fibres, extracellular deposits of microfibrils and of amorphous granular substance corresponding to the Alcian blue positive deposits seen by conventional histochemistry. The in vitro growth of fibroblasts was normal. CONCLUSION: Authors reviewed aetiopathogenic hypotheses. Our data suggest a genetically determined alteration of extracellular matrix production by fibroblasts as a possible explanation for the development of PDP.     

An ultrastructural pathological study of pterygium

OBJECTIVE: To study the ultrastructural changes of pterygium. METHOD: The pathological ultrastructure of pterygium was studied by Hu-12A transmission electron microscopy in 14 specimens. RESULTS: The result indicated that normal and abnormal elastic fibers and collagenous fibers existed in the pterygium. As hyperplastic fibers intruded into the corneal subepithelium, Bowman's membrane was broken. To a certain extent, blood vessel multiplication and degeneration were found in the pterygium. One of the important factors was blood vessel multiplication and degeneration which affected the occurrence and development of pterygium. CONCLUSION: Multiplication and degeneration of elastic and collagenous fibers were the prominent pathological changes, and the pre-elastic fibers and denatured elastic fibers were the main compositions of pterygium.     

Chloroquine-induced achromotrichia. An ultrastructural study

BACKGROUND: Electron microscopy examination of scalp biopsies from a patient with chloroquine achromotrichia gave elements concerning the pathogenesis of chloroquine-induced achromotrichia. CASE REPORT: A 21-year old light brown-haired patient developed achromotrichia after four months of treatment with chloroquine for subacute lupus erythematosus. Hair bleaching completely regressed 5 months after discontinuing chloroquine despite replacement with hydroxychloroquine. During the achromatrichia phase, many ultrastructural anomalies were observed in the hair root melanocytes: the nuclei were small and densified, and there was an accumulation of immature melanosomes in the cytoplasm; these melanosomes, mainly in stage II, were rarely transferred to keratinocytes. After recovery from the achromotrichia, melanocytes displayed a normal aspect. DISCUSSION: Pathophysiological disturbances leading to chloroquine induced achromotrichia are still unclear. The ultrastructural study of hair follicles in our patient show that under chloroquine action melanocytes become unable to perform complete melanin synthesis and to produce normally melanized melanosomes which may be transferred to keratinocytes. Non-melanized or poorly melanized melanosomes accumulate in the melanocytes which finally become inactive cells. These findings suggest that achromotrichia is induced by a toxic effect of chloroquine on the melanocyte.     

An ultrastructural study of the phagocytosis of Burkholderia pseudomallei

Burkholderia pseudomallei causes melioidosis and is believed to be an intracellular pathogen in human and animal disease. The uptake of B. pseudomallei by mouse peritoneal macrophages and cells in tissue culture was examined by electron microscopy. In all the systems studied B. pseudomallei were phagocytosed and apparently inhibited the normal processes of intracellular killing. Destruction of the phagosome membrane occurred and the bacteria escaped into the cytoplasm.     

Venous hemangioma. An immunohistochemical and ultrastructural study

OBJECTIVE: To elucidate the roles of integrins in tumorigenesis, progression, differentiation, invasiveness and metastasis, and the role of the integrin alpha 5 subunit in hepatocellular carcinoma (HCC). METHODS: 79 formalin-fixed sections of hepatocellular carcinoma (HCC) were obtained. The integrin alpha 5 subunit was measured by immunohistochemistry assay (ABC method). RESULTS: In 79 cases of HCC, cancerous tissues had lower expression than their adjacent non-tumor tissues (32.9% vs 81.0%, P < 0.01). The alpha 5 positive rate in small HCC (= < 5 cm in diameter) was higher than large HCC > 10 cm in diameter), being 55.6% and 10.0% respectively. Well-differentiated HCC expressed higher alpha 5 than poorly differentiated ones. The alpha 5 positive rates were lower in highly invasive HCC than those to low invasive ones. CONCLUSION: Our study indicated that expression of the integrin alpha 5 subunit is correlated with growth, differentiation, invasiveness and metastasis of HCC. It is possible that alpha 5 subunit is a negative regulator to these biological parameters of HCC.     

Papillary cystadenoma of the epididymis. An ultrastructural and immunohistochemical study

Papillary cystadenoma of the epididymis is a rare neoplasm that is sometimes associated with von Hippel-Lindau's syndrome. Electron microscopic study of the present case revealed that neoplastic cells contained abundant glycogen granules and large lipid droplets, but a few organelles. On the apical surface there were numerous microvilli and a few single cilia, but no ciliated cells. Subepithelial basal lamina was noted, but it was occasionally disrupted. Furthermore, microvilli sprang from the circumference of the small tumor-cell nest and became associated with matrix components (microvillus-matrix associations). On immunohistochemical study, neoplastic cells showed epithelial characteristics, but positive reactivity for S-100 protein. These findings resembled those of the epithelial cells of the efferent ductules of the epididymis. In the stroma, prominent vasculature was characteristic and fenestrated-type capillaries were found in the peripheral portion of the tumor. Papillary cystadenoma of the epididymis may originate from non-ciliated epithelial cells of the efferent ductules.     

Goblet cell carcinoid of the appendix. An ultrastructural and histochemical study

In a patient with a goblet cell carcinoid tumor of the appendix, light and electron microscopical studies demonstrated mucinous material and enterochromaffin granules within the same cell. Transitions between cells containing primarily mucin and cells containing numerous argentaffin granules were observed. Fluorescence studies demonstrated that the tumor cells contain biogenic amines.     

Development of the human fetal visceral pleura. An ultrastructural study

OBJECTIVE: To develop a method to predict long-term outcome after head injury and determine if outcome can be accurately predicted 24 hours after injury. DESIGN: A retrospective review was performed on a study cohort of 672 head-injured patients admitted in coma (Glascow Coma Scale score < or = 8) who remained comatose for at least 6 hours, survived more than 24 hours, and had 6-month outcome data available. Stepwise logistic regression analysis was used to determine which clinical variables predicted 6-month outcome. Statistically significant clinical predictors were combined into a single examination variable (MPX score), which reflected a rank-ordering of examinations from worst to best, which was then further weighted by patient age. The relation between 6-month outcome and MPX score at admission and 24 hours was plotted and analyzed. MEASUREMENT AND MAIN RESULTS: Age, best motor score, and pupillary reactivity at admission and 24 hours were significant predictors of outcome; extraocular motility was predictive at 24 hours only. Age was the most important independent predictor, followed by best motor score, pupillary reactivity, and extraocular motility. Combining these predictors into MPX score resulted in a set of graphs that reliably predicted long-term outcome. The 24-hour MPX data were better predictors of 6-month outcome and were more specific in predicting negative outcomes than admission data. CONCLUSIONS: The method is simple to use, relying on bedside neurologic examination and a single graph, but appears to predict long-term outcome accurately as early as 24 hours after head injury. If validated on other large series of patients, this method could provide an objective and practical basis for terminating care in patients unlikely to survive a head injury.     

An ultrastructural study on resting cyst of Euplotes encysticus

For resting cysts of Euplotes encysticus, in their various ciliatures, most of the ciliary shafts above the cilia kinetosomes are degenerated, or preserve their kinetosomes only. Sometimes, kinetosomes of certain frontal and ventral cirri are also disintegrated and disappeared. For remaining cilia, on their shafts, peripheral doublet microtubule (MT) and central pair of MTs still possess their structural pattern of "9 + 2". In few ciliary shafts, the phenomena of 2 sets of "9 + 2" structures surrounded by a common sheath can also be seen. At the center of kinetosomal peripheral triplets (triplet MTs), aggregates of MT-like structures are formed. For kinetosomal accessory structures, only residues of inter-kinetosomal connections and ciliature brackets can be seen. No MT layers can be seen under the pellicles of non-ciliated cortex. At the ciliated cortex, there are peripheral MT layers (corresponding to sub-pellicular MT layers) within the ciliature cavity, MT ribbons at (and near) the deeper parts of ciliature, and scattered MT groups. Besides, various shapes of ciliary shafts structures are seen within cortical vesicles of ciliated regions. Nuclear pores of macronucleus enlarged apparently, reduced in number, and, chromatin attached on the inner membrane of these nuclear pores.     

An ultrastructural study of the intimal hyperplasia in healing microarterial anastomoses

The purpose of the study was to investigate the ultrastructure of intimal hyperplastic cells. End-to-end microarterial anastomoses were studied in a rabbit free-tissue-transfer model. There were five experimental groups, with 1, 3, 7, 14, or 28 days follow-up. At sacrifice the anastomoses were tested for patency and then examined by light and electron microscopy. At days 1 and 3 the repaired intima was covered with macrophages and extravasated erythrocytes. At day 7 spindle-shaped fibroblasts with copious rough endoplasmic reticulum were seen. Some of these cells also contained pinocytotic vesicles, filaments with focal densities, and subplasmalemmal attachment sites, the features of smooth muscle cells. At day 14, more cells contained smooth muscle features and these features were also more pronounced. These young myofibroblasts were plumper than adjacent fibroblasts. At day 28 mature myofibroblasts with a full complement of organelles were present. The results, therefore, supported the hypothesis that myofibroblasts are present in the intimal hyperplasia of healing microarterial anastomoses.     

Eosinophilic granular ceels in oligodendrogliomas. An ultrastructural study

In three cases of oligodendrogliomas, atypical cells rich in eosinophilic cytoplasm, resembling plump astroyctic or astroblastic cells, were studied under the electron microscopy. These cells showed finely granular cytoplasm with routine hematoxylin-eosin preparation; ultrastructurally, they exhibited abundant, round cytoplasmic bodies of autophagic-vacuole type, in addition to other fine structures characteristic of oligodendroglioma cells.     

Functioning oxyphil adenoma of parathyroid gland. An ultrastructural and biochemical study

Oxyphil cells and oxyphil cell adenomas of parathyroid glands are, in most instances, regarded to be nonfunctioning. Although 21 cases of hyperparathyroidism associated with parathyroid oxyphil cell adenoma have been reported, secretion of hormone by these tumors has not been conclusively demonstrated. A parathyroid adenoma, diagnosed by light microscopy as oxyphil type, together with the results from ultrastructural and biochemical studies of the patient's adenomatous tissue, are reported here. The patient, a 64-year-old male, was found to have elevated serum calcium, low serum phosphorus, and elevated serum immunoreactive parathormone: findings consistent with hyperparathyroidism. After excision of two small normal-appearing glands and one greatly enlarged (1.9 g) parathyroid gland, those laboratory values returned to normal. Light microscopy of the enlarged parathyroid indicated that it consisted almost entirely of an oxyphil adenoma. Electron microscopy revealed that the adenoma was composed mainly of mitochondria-rich oxyphil cells but also of interspersed transitional oxyphil cells and rare scattered chief cells. Golgi zones, rough endoplasmic reticulum, and prosecretory and secretory-like granules were observed in some oxyphil cells, in most transitional oxyphil cells, and in the infrequent chief cells. Thus, many of these cells appear to contribute to the production and secretion of parathormone. Biochemical studies performed directly on the adenomatous tissue demonstrated that it was able to synthesize proparathormone and parathormone, although the proportion of hormonal peptide synthesis relative to that of the total protein synthesis in this tissue was much smaller (0.9%) than that found in normal parathyroid tissue (5.7%). There was a small increase in immunoreactive parathormone when the adenoma tissue was incubated in a low-calcium medium. These findings indicate that this oxyphil adenoma of the parathyroid gland synthesized and secreted parathormone, apparently to some extent autonomously, but suggest that its capacity to do so was largely dependent on its component of cells other than fully developed oxyphil cells, such as transitional oxyphil cells.     

An ultrastructural study of the hippocampal neurons in mice subjected to heat exposure

The ultrastructure of hippocampal neurons in mice subjected to heat treatment for 40 min at 42 degrees C was studied. Such a treatment has been shown to result in significant changes in the structure of pyramidal neurons. An increased chromatin condensation in the nuclei was found in addition to deep invagination of their envelopes and reduction or fragmentation of the reticulum cisterns. These changes were accompanied by mitochondrial swelling and increased number of clathrine vesicles around the Golgi complex. The heat exposure followed by feeding on vitamins and beta-carotin appeared to diminish chromatin condensation and kept the cisterns invariable.     

Efficacy of pancreatic transplantation on cardiovascular alterations in diabetic rats: an ultrastructural and immunohistochemical study

OBJECTIVES: To determine whether a neural network is superior to standard computational methods in predicting stone regrowth after shock wave lithotripsy (SWL) and to determine whether the presence of residual fragments, as an independent variable, increases risk. METHODS: We reviewed the records of 98 patients with renal or ureteral calculi treated by primary SWL at a single institution and followed up for at least 1 year; residual stone fragment growth or new stone occurrence was determined from abdominal radiographs. A neural network was programmed and trained to predict an increased stone volume over time utilizing input variables, including previous stone events, metabolic abnormality, directed medical therapy, infection, caliectasis, and residual fragments after SWL. Patient data were partitioned into a training set of 65 examples and a test set of 33. The neural network did not encounter the test set until training was complete. RESULTS: The average follow-up period was 3.5 years (range 1 to 10). Of 98 patients, 47 had residual stone fragments 3 months after SWL; of these 47, 8 had increased stone volume at last follow-up visit. Of 51 patients stone free after SWL, 4 had stone recurrence. Coexisting risk factors were incorporated into a neural computational model to determine which of the risk factors was individually predictive of stone growth. The classification accuracy of the neural model in the test set was 91%, with a sensitivity of 91%, a specificity of 92%, and a receiver operating characteristic curve area of 0.964, results significantly better than those yielded by linear and quadratic discriminant function analysis. CONCLUSIONS: A computational tool was developed to predict accurately the risk of future stone activity in patients treated by SWL. Use of the neural network demonstrates that none of the risk factors for stone growth, including the presence of residual fragments, is individually predictive of continuing stone formation.     

The human yolk sac and yolk sac carcinoma. An ultrastructural study

The ultrastructure of the yolk sac of a 39 day old human embryo was studied. The subcellular organization was suggestive of a highly specialized absorptive function proceeding in an exocelomic-viteline direction. These findings, compatible with intense metabolic activity, are at variance with the concept of rapid involution of the yolk sac following completion of its hemopoietic and angiogenetic functions. The speculation is advanced that a potential avenue exists in the yolk sac whereby maternally derived products encounter fetal endoderm. Ultrastructural features in the normal yolk sac were compared to those existing in a tumor showing the "endodermal sinus" pattern, and reviewed in the light of the pertinent literature. These findings support the concept that attributes an endomesoblastic derivation to such neoplasms.     

An ultrastructural study of the erythrocytes associated with haematochemical data of the camel Camelus dromedarius

The aims of the present study were to characterize by electron microscopy the morphological features of the erythrocytes of normal adult and young camels Camelus dromedarius in a renal blood vessel and in a smear. These cells are thin and elliptical, with a slight central elevation. They are slightly larger, but thinner than those reported by other authors. It is found that the renal blood vessels in adults have a thicker basal lamina with the presence of electron dense membranous bodies. These two features were described in different parts of the uriniferous tubules of the camel in previous studies. The numerical data of the haematochemical parameters that are reported here are in general similar for both adult and young camels, while they differ from those of other studies, this may have resulted from their unknown provenance and their previous dietary regime. Moreover, these parameters probably relate to the arid environment of the animal.     

Development of the thyroid gland in the rat fetus in vivo. An ultrastructural and radioautographic study

A study of the differentiation of the thyroid follicles was carried out in rat fetuses between day 14 of pregnancy, when cellular polarization begins and day 18, when completely formed follicular lumina are differentiated. After day 18, only the shape and the size of the lumina undergo modifications. The mechanism of folliculogenesis involves the participation of several structures. At 14 days of pregnancy, adherens type contact zones with membrane densification appear between the cells. These junctional zones spread out and form infoldings which deeply penetrate the cytoplasm. Golgi vesicles migrate to these zones and they fuse among themselves and with the contact membranes : follicular cavities result which can be recognized as soon as day 16 of pregnancy. A radioautographic study showed the beginning of iodide organification at 17 days 11 hours of pregnancy. From this time onward silver grains were seen over the follicular cavity, even it is still incompletely formed.     

Do nasal ciliary changes reflect bronchial changes? An ultrastructural study

Ciliary dyskinesia is characterized by recurrent respiratory tract infections secondary to abnormal ciliary structure and function. The diagnosis of ciliary dyskinesia is based on the detection of axonemal ultrastructural abnormalities (AUA) is respiratory mucosa samples. In most cases, the diagnosis of AUA is made on samples obtained from nasal ciliated cells with little discomfort to the patient. However, no studies have been performed in the same patient to confirm whether nasal samples reflect bronchial ciliary changes. To answer this question and to determine whether it is necessary to sample bronchial cells for the diagnosis of ciliary dyskinesia, we investigated 12 patients (between the age of 5 and 63 yr) with chronic sputum production. The presence of situs inversus, bronchiectasis, chronic sinusitis, and sterility was investigated to determine an inherited disorder. Two groups were established: Group 1 = six patients with an inherited disorder and Group 2 = six patients without evidence of an inherited disorder. Samples were obtained by brushing or biopsy of nasal and bronchial mucosa and were processed for transmission electron microscopy. In Group 1, the mean AUA was 65.2 +/- 11.4%. The following predominant axonemal defects were found: absence of dynein arms (DA) (four patients), central complex abnormalities (CC) (one patient), and various AUA (one patient). Nasal and bronchial samples correlated significantly for total AUA (r' = 1, p < 0.01) and for outer DA defects (r' = 0.96, p < 0.05). A good but not significant correlation was found for inner DA (r' = 0.83) and peripheral microtubule (PM) defects (r' = 0.71). In Group 2, the mean AUA was 9.6 +/- 2.3%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Acute murine adrenalitis induced by reovirus 3. An ultrastructural study

Reovirus 3 infection of neonatal mice, although characterized primarily by encephalitis, hepatitis, and pancreatitis, also induces an adrenalitis. Histologically, the latter is characterized initially by foci of coagulative necrosis which later enlarge and become surrounded by leukocytic infiltration. Ultrastructurally, the virus was shown to replicate in the paranuclear region of mainly adrenocortical cells but also medullary and endothelial cells. Apoptosis is the most common form of necrosis exhibited and is quickly followed by an infiltration of mononuclear phagocytes which eventually ingest the virus and the cellular debris.