[Multiple primary cutaneous plasmacytoma]

BACKGROUND

Primary cutaneous plasmacytoma is a rare form of cutaneous B-cell lymphoma.

PATIENTS AND METHODS

A 51 year-old male with an unremarkable history gradually presented erythematous papulonodular lesions that had appeared gradually over the whole body throughout a two-year period and showing histologic and immunohistochemical features of cutaneous plasmacytoma. Staging investigations confirmed the primary character of the disease, and because of this and the absence of functional impairment, we opted for therapeutic abstention. No progression was noted after 4 years of regular monitoring.

DISCUSSION

Primary cutaneous plasmacytoma (PCP) is characterized by clonal proliferation of plasma cells in skin. Multiple PCPs are extremely rare and to date have been treated in most cases by chemotherapy, either with or without radiotherapy. The prognosis is poor, with 2-year survival of only 25%. The present case is original, being the only one to our knowledge in which therapeutic abstention was followed by a lack of progression after 4 years of regular follow-up. Consequently, certain indolent forms of PCP do not warrant automatic institution of chemotherapy.

[Neonatal Volkmann's syndrome]

BACKGROUND

Acute limb compartment syndrome or Volkmann's ischaemic contracture is an acquired ischaemia of nerve and muscle causes by raised pressure within a closed fascial space. Congenital Volkmann's ischaemic contracture (CVIC) is a rare entity.

PATIENTS AND METHODS

A 2-day-old girl was referred with a problem of the left forearm and arm, which exhibited cold oedema with decreased mobility. Lesions were present at birth and were rapidly complicated by skin necrosis. The mother was taking olazanpine, prazepam and valpromide throughout the entire pregnancy. Delivery was complicated by shoulder dystocia requiring obstetric procedures such as suprapubic pressure, Couder's maneuver and episiotomy. On physical examination her left hemi-thorax, left arm, forearm and hand exhibited marked oedema. A large and well-demarcated bullous, fibrous and ulcerated area of skin necrosis was observed on the elbow fold and on the inner anterior part of the arm. Digital flexion with cyanosis was present. MR angiography revealed extensive oedema of the soft tissue and muscle with fascial effusion, associated with compression of the arm arteries and reduced blood flow in the forearm. A fasciotomy was performed at Day 3 of life. The postsurgical arterial MRI was normal. At Day 10 of life, the patient developed opisthotonos involving spasms and tremors associated with numerous intercritical abnormalities evoking benzodiazepine weaning syndrome. The child's neurological status was stabilized by treatment with phenobarbital and clonazepam. She was subsequently lost to follow-up.

DISCUSSION

CVIC has been ascribed to multiples causes. Mechanical compression is the main recognized factor: amniotic band constriction, umbilical cord loops, compression in utero by a deceased co-twin, malposition of the hand, arm or forearm, local or general factors that can add to extraction problems: brachypelvic disproportion, extraction with forceps, oligo/polyhydramnios, pre-term delivery, pre-eclampsia, caesarean section, premature labour, excessive maternal weight gain or diabetes. Our case emphasized three main points. First, the diagnostic value of early MR angiography in the event of associated extensive tissue oedema, multiple arterial compression and decreased vascular perfusion. Second, the role of shoulder dystocia in triggering the traumatic factor reported for the first time. Third, the role of neuroleptic and anxiolytic treatments taken by the mother during pregnancy. Prazepam is a long-acting benzodiazepine that can cause impregnation and withdraw syndromes in neonates. Impregnation "floppy infant syndrome" is an early event characterized by hypotonia, hypoventilation and lethargy. Hypotonia and decreased foetal movements may favour prolonged pressures and malposition with secondary crush injury during delivery. Maternal medication has not been cited hitherto as an aetiological factor in neonatal compartment syndrome.

Ultraviolet AI exposure of human skin results in Langerhans cell depletion and reduction of epidermal antigen-presenting cell function: partial protection by a broad-spectrum sunscreen

BACKGROUND

Ultraviolet (UV) B-induced effects on the skin immune system have been extensively investigated, but little is known regarding the immunological changes induced by UVA exposure of human skin. Recent data assessing the protection afforded by sunscreens against photoimmunosuppression stress the need for broad-spectrum sunscreens with an adequate UVA protection.

OBJECTIVES

The purpose of this study was first to determine the changes observed in epidermal Langerhans cells (ELC) density and epidermal antigen-presenting cell (APC) activity after exposure of human skin to UVAI (340-400 nm) radiation, and secondly to assess the immune protection afforded in vivo by a sunscreen formulation containing a long wavelength UVA filter with a low UVA protection factor (UVA-PF = 3).

METHODS

Epidermal cell (EC) suspensions were prepared from skin biopsies 3 days after exposure to a single dose of UVAI (either 30 or 60 J cm(-2)).

RESULTS

Flow-cytometric analysis of EC suspensions revealed that exposure to 60 J cm(-2) UVAI resulted in a decreased number of ELC without infiltration of CD36+ DR+ CD1a- antigen-presenting macrophages into the epidermis, and a significant reduction of HLA-DR expression on viable ELC. In vivo exposure to both 30 and 60 J cm(-2) resulted in a decreased allogeneic CD4+ T-cell proliferation induced by UVAI-irradiated ECs. The sunscreen application partially prevented (57 +/- 9%) the decrease in epidermal allogeneic APC activity induced by 60 J cm(-2) UVAI.

CONCLUSIONS

In vivo UVAI exposure of human skin results in a decreased number of ELC and in a downregulation of epidermal APC activity. This last effect is partially prevented by prior application of a sunscreen with a low UVAI-PF value. These results indicate that increasing the absorption of UV filters for long UVA wavelengths may lead to an improved immune protection.

[Extensive primary cutaneous mucinosis associated with refractory anemia with excess of blast]

BACKGROUND

We describe an original case of a primary cutaneous mucinosis, associated with a refractory anemia with excess of blast.

CASE REPORT

A 65 year-old female consulted for erythematous-purple blush reticulated and large plaques that progressively developed on the trunk and limbs. Biopsies showed abundant dermis mucin deposits with a perivascular lymphocytic infiltrate. The epidermis was normal. Laboratory evaluation showed refractory anemia with excess of blast, associated with cytogenetic abnormalities. After two years course, the progressive aggravation of the myelodysplastic syndrome was associated with a progressive extension of the cutaneous mucinosis.

DISCUSSION

This is the first report of an atypical primary diffuse and extensive cutaneous mucinosis. Primary cutaneous mucinosis may be associated with systemic diseases. To our knowledge, the association with refractory anemia with excess of blast has not been described previously. Mucine deposits may be considered as a consequence of neutrophilic dysfunction that are observed in myelodysplastic syndromes.

Morphometric analysis of the peripheral nerve: advantages of the semi-automated interactive method

A semi-automated interactive method (BIOCOM) was developed for the morphometric analysis of the peripheral nerve in routine histopathological examination. The human superficial peroneal nerve was used for myelinated fibre measurements. The precision and reproducibility of the results were validated using a manual morphometric method on a digitalizing table. Having compared the two methods, we believe that the semi-automated method constitutes an interesting alternative to traditional methods.

Enhanced chemiluminescence: a high-sensitivity detection system for in situ hybridization and immunohistochemistry

The breakthrough of chemiluminescence in the field of solution immunoassays and transfer membranes prompted us to explore whether a light-based detection system could provide a gain in sensitivity over chromogenic and FITC markers for nucleic acid and protein detection on histological preparations. A Hamamatsu device and an enhanced chemiluminescence (ECL) luminol substrate of the peroxidase were used to detect epithelial and endothelial components by immunohistochemistry (IHC) and for in situ hybridization (ISH) of papilloma virus DNA. The accuracy of the signal was compared to that obtained with DAB-peroxidase, silver-enhanced DAB-peroxidase, NBT-BCIP-alkaline phosphatase, and FITC. Our results demonstrated the feasibility and high sensitivity of luminescence detection for histological preparations. In part due to the ultrasensitive videocamera and photon-counting imaging, interpretable and reproducible results were obtained within counting times shorter than 5 min, and with dilutions of the primary antibodies 100- to 10,000-fold greater than those used for chromogenic and FITC reactions. As for ISH, with identical concentrations of the HPV 18 DNA probe on HeLa cells, labeling was apparent by luminescence but undetectable with the chromogen. The morphological resolution allowed a discriminatory analysis of the signal. Therefore, at the light microscopic level, enhanced chemiluminescence offers an appealing alternative to FITC and chromogenic markers for detection and quantification of low-concentration molecules.

Herpes simplex virus ICP0 and ICP4 immediate early proteins strongly enhance expression of a retrovirus harboured by a leptomeningeal cell line from a patient with multiple sclerosis

A leptomeningeal cell line (LM7) harbouring an unknown retrovirus was recently isolated from the cerebrospinal fluid of a patient with multiple sclerosis. However, spontaneous expression of the LM7 retrovirus in this primary culture is quite low. We present results showing that in vitro infection of LM7 cells with herpes simplex virus type 1 (HSV-1), but not that of control cells, results in (i) potent stimulation of the specific reverse transcriptase (RT) activity detected in the culture supernatant and (ii) co-expression of both typical HSV-1 virions and abundant retrovirus-like particles. Transfection of LM7 cells with plasmids expressing HSV-1 immediate early (IE) ICP0 and ICP4 proteins produced a similar enhancement of RT activity in culture supernatants with retrovirus-like particles being identifiable by electron microscopy. These effects were not observed with a plasmid expressing ICP27 or with the parental plasmid in LM7 cells, nor with any of these four plasmids in control cells. These results show that HSV IE trans-activating proteins strongly enhance the expression of the latent retrovirus present in LM7 cells. The possible role in vivo of herpesviruses as 'triggering' cofactors in the retrovirus hypothesis for multiple sclerosis aetiology is also discussed.

In vitro transmission and antigenicity of a retrovirus isolated from a multiple sclerosis patient

We have recently isolated an apparently novel retrovirus (LM7) from a patient with multiple sclerosis (MS). We present here results showing that (1) LM7 retrovirus can be transmitted in vitro to a normal human leptomeningeal cell culture and that (2) specific antibody against this retroviral strain can be detected in MS cases. Our results suggest that, if this virus is an endogenous retrovirus, it is different from human endogenous elements already described.

Basal cell (basaloid) carcinoma of the lung: a new morphologic and phenotypic entity with separate prognostic significance

On review of 115 poorly or undifferentiated lung cancers from 671 lung tumors resected over a 7-year period, we have found 38 cases of basaloid carcinoma. The cardinal histopathologic features distinguishing this tumor from other non-small cell lung cancers are a lobular growth pattern of small cells with moderately hyperchromatic nuclei, with no prominent nucleoli, and with scant cytoplasm, a high mitotic rate, and peripheral palisading. Basaloid carcinoma was present in a pure form in 19 cases and the other 19 tumors were of a mixed, but prominent, basaloid type associated with squamous cell carcinoma, large cell carcinoma, or adenocarcinoma. The immunophenotype of basaloid cancers was close to that of basal bronchial epithelial cells, with a low level of expression of low molecular weight cytokeratins. Staining for neuroendocrine markers was infrequent and inconsistent. Ultrastructural study showed an absence of neurosecretory granules and the presence of some squamous and/or glandular differentiation. This morphologic and immunologic phenotype suggests that basaloid carcinoma is derived from a pluripotent reserve cell or a basal bronchial epithelial stem cell. This unique histologic form of lung tumor has a poor prognosis, with a median survival rate of 22 months for stage I and II disease. This justifies classification of basaloid carcinoma as a distinct form of lung cancer, separate from small cell lung carcinoma.

Ultrastructural localization of the major components of the extracellular matrix in normal rat nerve

In this study we determined the ultrastructural distribution of the various components of the extracellular matrix (laminin, fibronectin, Type I, III, and IV collagens) of the normal peripheral nerve in adult rat. The localization of these macromolecules was investigated in basement membranes as well as in different areas of epi-, peri-, and endoneurium, by use of a pre-embedding immunoperoxidase method.

[Cutaneous lesion associated with multiple endocrine neoplasms type 2A (Sipple's syndrome). An early clinical marker]

We report the association of a cutaneous lesion with multiple endocrine neoplasia type 2A (MEN 2A) in three patients from a French family. These lesions are very similar to those previously described in an Italian and an American MEN 2A family and called cutaneous lichen amyloidosis. In all three families the patients presented with a pruritic and pigmented cutaneous lesion localized unilaterally on the upper back. However, in the French family the patients also complained of paroxysmal pain in the same area, in which we could elicit a touch hypoesthesia and pain hyperesthesia. Such an association of cutaneous and neurological features in the upper back is known as Notalgia Paresthetica (NP). NP is believed to represent a neuropathy of the posterior dorsal nerve rami. Unlike the two previously reported families, the histological, immunohistochemical and ultrastructural analysis of the skin biopsies of the French patients did not show any amyloid material. This suggests that the presence of amyloid may not be a constant feature of the cutaneous lesions associated with MEN 2A. We consider these lesions as a form of dorsal neuropathy rather than a cutaneous lichen amyloidosis. Whatever their origin, these cutaneous lesion usually precede the appearance of the neoplastic lesions of MEN 2A. They may act as an early clinical marker that must be searched for in each subject at risk for MEN 2A. In addition, all patients presenting with NP should be screened for MEN 2A.

Ultrastructural changes associated with peripheral neuropathy in HIV/AIDS

Light and electron microscopic studies were performed on neuromuscular biopsy specimens from 12 neurologically affected seropositive patients, 7 with the acquired immune deficiency syndrome (AIDS), 2 with AIDS-related complex, and 3 with no symptoms except for neuropathy. All patients had an axonal injury associated or unassociated with demyelination and peripheral neurogenic atrophy. Capillary lesions were consistently present, which seems to be a new finding. Moreover, tubuloreticular inclusions (TRIs) were found in endomysial (9 of 12 cases) and endoneurial (7 of 12 cases) vessels. Statistical analysis showed that TRIs in more than 20% of endomysial vessels correlated with a survival time shorter than 12 months (P = 0.028). Thus the quantification of TRIs seems to be one of the vital prognostic elements in this patient population.

Thymolipoma in association with myasthenia gravis

A 52-year-old male presented with an anterior mediastinal tumor associated with a 2-year history of myasthenia gravis. The patient underwent thymectomy and a 185-g, 10 X 8 X 3.5 cm, well-delineated tumor was resected. On histologic examination the tumor proved to be a thymolipoma composed of mature adipose elements containing cords and nests of thymic tissue. The latter consisted mainly of cortical areas, the thymocytes of which displayed an immunohistochemical profile of cortical cells, i.e., CD 1+, CD 4+, CD 8+, and frequently Ki 67+. Ultrastructural study confirmed the predominant cortical differentiation of the thymic component. No germinal centers, dendritic reticulum cells, or myoid cells were detected by histologic, immunohistochemical, and ultrastructural studies. The association of thymolipoma with myasthenia gravis is rare; this case is the 10th reported. Our findings lead us to believe that (a) the cortical differentiation of the thymic component and the active thymocyte proliferation could represent a factor leading to myasthenia gravis; and (b) thymolipoma could be a peculiar form of thymoma rather than a mixed tumor of mesenchymal and entodermal origin, a lipoma, or a hamartoma of the thymic gland. The reported association of thymolipomas with other immune disturbances or with neoplastic conditions usually associated with true thymomas support these findings.

Melanin in the inner ear. An experimental study with control and kanamycin-intoxicated colored guinea-pigs

Following several studies on the effects of kanamycin toxicity on the inner ears of guinea pigs, we have studied the importance of melanin in this phenomenon. Transmission electron microscopy showed that, under the influence of kanamycin, the intermediate strial cells developed a secretory aspect similar to that seen in skin melanocytes. This aspect as yet has never been described for the inner ear cells. A planimetric, morphometric method was also used to determine the strial cell melanin status in control animals. Additional findings in the study confirmed an increase in the number of melanosomes during kanamycin poisoning. Statistical data are discussed.

There is no simple adequate sampling scheme for estimating the myelinated fibre size distribution in human peripheral nerve: a statistical ultrastructural study

Morphometric studies of peripheral nerves (PN) usually involve some sampling of the myelinated fibres (MF). In order to scrutinize the statistical properties of the sampling processes in common use and the reliability of the resulting estimates, a quantitative analysis of human superficial peroneal nerves from 8 different normal subjects was undertaken at the ultrastructural level, both in terms of MF spatial distribution and of their size distribution. This study used sampling rates involving more than 10% of the whole myelinated fibre population observed in each nerve fascicle. However, in nearly all the fascicles evaluated, the sampling fluctuations are so high that neither the number of axons nor their diameter distribution can be assessed with enough accuracy. A systematic study of the myelinated fibres shows that the spatial distribution of their size is not uniform. This marked heterogeneity in the MF size distribution imposes measurement of large enough samples (500 or 600 MFs usually represent about one-half or two-thirds of the whole MF population) in a way to secure a reliable enough estimate of the density and size distributions. However, the practical usefulness of sampling schemes requiring more than one-half of the whole MF population in a nerve fascicle, is questionable.

Microangiopathy of endoneurial vessels in hypoxemic chronic obstructive pulmonary disease (COPD). A quantitative ultrastructural study

A peripheral neuropathy has been reported in patients with chronic respiratory insufficiency due to chronic obstructive pulmonary disease (COPD). It is mainly characterized by axonal degeneration, secondary demyelination and abnormal endoneurial vessels. The pathogenesis of these lesions remains obscure. To investigate whether relationships exist between neuritic and vascular lesions, a qualitative and quantitative ultrastructural study was performed on nerve biopsies in 13 patients with chronic respiratory insufficiency due to COPD, and in 9 normal controls without pulmonary lesions. A computer-assisted multiple regression analysis taking into account clinical, electrophysiological, biological and morphometric parameters was performed. Statistically significant differences in the endoneurial structure of microvessels were: (1) thickening of the basement membrane; (2) narrowing of the lumen; (3) mural pericytic debris deposits, occurring in the COPD group. In the latter, hypercapnia correlated positively with nerve fibers lesions (P = 0.03) and endothelial area (P = 0.03). No correlations were found between age and other parameters. These findings highlight the fact that the microangiopathy in peripheral nerves in patients with COPD may be diffuse and essentially due to hypoxia and reduction in blood flow, as in diabetic neuropathy.

Melanine value in the stria vascularis of pigmented guinea-pigs treated by kanamycin

In a previous report, kanamycin (400 mg/kg/d) seemed to increase the number of melanine granulations in intermediate cells of the stria vascularis, especially in the second and third turns. To precise these data, melanine was studied in those turns by ultrastructural morphometry in a control group with 12 animals. We observed a large intra-individual and inter-individual variation before intoxication. Thus, the meaning of melanine modifications by kanamycin must be carefully evaluated.

[Incidence of polyneuropathies in chronic obstructive bronchopneumopathies]

In a prospective study 43 patients with chronic obstructive lung disease and severe respiratory insufficiency were systematically investigated for polyneuropathy, although they had no risk factor of that disease. Electrophysiological recordings showed slight or significant signs of polyneuropathy in 17 and 15 patients respectively, thus indicating that the condition is frequent. Clinically, it was often silent or manifested only by sensory disorders predominant in the lower limbs. Electrophysiology suggested axonal degeneration associated with some degree of demyelinization, and these lesions were found at histology to be present in sensory nerves. Histological examination of the muscles showed peripheral mixed neurogenic atrophy probably due to hypoxia. Major thickening of basal material was observed in capillaries of the endomysium and endoneurium. Statistical analysis of clinical parameters and respiratory function values in relation to the presence and importance of polyneuropathy showed that the only significant difference was the longer duration of hypoxia in patients with nerve involvement. Age, alcoholism and the other respiratory function values did not seem to be correlated with lesions of the peripheral nervous system.

[Neuropathies and chronic respiratory insufficiency: electrophysiologic study]

In order to determine the frequency and the characteristics of neuropathies in chronic respiratory insufficiency, a systematic study of 43 patients affected by a chronic obstructive pulmonary disease was performed. In addition to neurological and electrophysiological examinations (including 6 nerve conduction studies on median, ulnar and peroneal nerves and EMG of 4 to 8 muscles), nerve and muscle biopsies (of the superficial peroneal nerve and lateral peroneus brevis muscle) were performed in 13 cases. Polyneuropathies were found in 74% patients: but mild in 39%, severe in 35%. Most were subclinical or poorly symptomatic. We determined the importance and distribution of abnormalities on the different nerves. From this we established that neuropathies are mixed but predominantly of the axonal type. Axonal degeneration and demyelination were confirmed by nerve biopsy; muscles presented neurogenic atrophy. Statistical analysis showed that the duration of hypoxemia was related to neuropathy. The pathogeny of these neuropathies is discussed.

The density of myelinated fibres is related to the fascicle diameter in human superficial peroneal nerve. Statistical study of 41 normal samples

The density of myelinated fibres in the superficial peroneal nerve was studied in 41 samples from 24 control human subjects. Photographic montages of the whole nerve fascicle were made from semithin and ultrathin transverse sections and used for a statistical analysis of sampling procedures, range of variations and relations between density and other variables. The results indicate that the spatial distribution of myelinated fibres within a nerve is often non-uniform. Therefore, it was not possible to define a statistically valid sampling system. The study of relations between variables shows the lack of any correlation between density and age and a considerable variation in the density. In contrast, there is a strong positive linear correlation between the surface area of the nerve fascicle and its content of myelinated fibres. That is, the fibre density of a given normal nerve is related to its diameter and can be predicted within a narrow range of error. We propose the term "derived density" for this value, and its application as a tool in the diagnosis of peripheral neuropathies is now being studied.

[Giant axonal neuropathy. Apropos of a case]

A new case of giant axonal neuropathy is reported about an 11 years old boy born with the Robin anomalad. The diagnosis is based on a peripheral nerve biopsy. This new observation can be added to 12 others ones which have already been published to study the characteristics of this peripheral neuropathy. The etiology and physiopathology are unknown.

[Muscular ultrasonic diagnosis. Etiological approach to various backaches]

Certain cases of mechanical back pain present unusual clinical and ultrasonographic features involving the posterior lumbar muscle groups, which can be used to distinguish various types. The clinical examination may isolate a juxta-vertebral territory in which pressure triggers or exacerbates the back pain; anaesthesia of this territory is accompanied by pain relief. Ultrasonography may reveal a hypoechogenic area in this muscle territory in which histomorphometric and ultrastructural studies, performed in three cases, revealed endomysial and perimysial adiposis associated with atrophy probably due to peripheral neuropathy.

Results of an ultrastructural study comparing stria vascularis with organ of Corti in guinea pigs treated with kanamycin

Ultrastructural study of ototoxicity is well documented with two points of interest: organ of Corti for aminoglycosides and stria vascularis for loop diuretics. As a previous study suggested initial lesions of stria vascularis, an attempt of comparison and of chronological study was made between the organ of Corti and stria vascularis lesions by kanamycin intoxication. The method was devised by J. M. ARAN, with electrophysiological control. We failed to find in the stria vascularis a radial or longitudinal pattern of lesions. We could not discern a chronological injury between the organ of Corti and stria vascularis because both were damaged even in the less deafened animals. Nevertheless, two facts were clarified: hair cell lesions are lysosomial as for the kidney lesions, while stria vascularis lesions are mitochondrial, melanine granulations play a part in drug metabolism (increased number, secretory aspect) and deserve further study.

[Association of cryoglobulins and hepatic disease: incidence, nature and immunochemical characteristics of cryoglobulinemia]

Mixed cryoglobulinemia associated with liver disease is well known, but its mechanism and signification still have to be elucidated. The purpose of this study was to identify and to characterize hepatic disease by their immunochemical features among 60 patients presenting with mixed cryoglobulinemia. Thirteen cases of alcoholic liver disease and 8 of virus B hepatitis out of 40 cases in all of hepatic disease in this group were studied. A higher frequency of type III immunochemical features of cryoglobulinemia in alcoholic disease (83 p. 100), no matter how severe, as well as a higher frequency of type II in virus B hepatitis (62 p. 100) was demonstrated. There was no relationship between virus B hepatitis and cryoglobulinemia in our population. Therefore, the responsibility of virus B hepatitis in essential mixed cryoglobulinemia genesis has to be clarified. The localization of cryoglobulin in the Kupffer cell in two patients with chronic hepatitis confirms the essential role of the reticuloendothelial system in blood clearance of circulating immune complexes.

[Muscles and nerves in rheumatoid arthritis]

The authors report the results of a systematic study of 37 hospitalized cases of rheumatoid arthritis. The neurological and muscular clinical signs are usually discrete. Electrophysiological examination is the basis for a classification in terms of the extent and the intensity of the neuropathy. Clinical and laboratory correlations are established permitting the individualization of a group of patients with severe neuropathy. The histological, morphometric and ultrastructural examination of 12 muscle and nerve biopsies reveal the high incidence of these lesions and the constancy of capillary involvement.

Effect of chrysotile and crocidolite on the morphology and growth of rat pleural mesothelial cells

The effects of the UICC asbestos fibers chrysotile A and crocidolite on the morphology and growth of rat pleural mesothelial cells were examined. The response was different according to the fiber used. Within 4 hr of treatment with 5, 10, 20, or 50 micrograms/ml of chrysotile fibers, cell morphology showed intense vacuolization, in both logarithmic and confluent cells. Following treatment of growing cells with 20 or 50 micrograms/ml of chrysotile fibers, cell spreading was also observed. Four hours after treatment of cells with 5, 10, or 20 micrograms/ml of crocidolite fibers, no such changes were seen. Vacuolization appeared later and was much less marked than for chrysotile fibers. The mesothelial cell population-doubling time of about 30 hr was not significantly altered by addition of 5 to 20 micrograms/ml of crocidolite fibers, but a concentration of 50 micrograms/ml lengthened doubling time to about 90 hr. Treatment with 5 or 10 micrograms/ml chrysotile fibers usually prolonged this time, but 20 or 50 micrograms/ml caused cell lysis. After 48 hr of incubation with both types of fiber, the proportion of mitosis was the same as in control cultures, whatever the fiber concentration, and asbestos fibers were often seen inside dividing cells.

Ultrastructural diagnosis of pleural tumors

The significant association of two kind of mesothelial cells, differentiated and fibroblastoid, caracterises the ultrastructure of malignant pleural mesotheliomas. The differentiated mesothelial cancer cells (MCC's), whether they are observed in fluids or in biopsies, are not caracteristic enough to assert the diagnosis of mesothelioma. They can easily be mistaken for metastatic cells. Therefore, the diagnosis of mesothelioma relies on the identification of fibroblastoid MCC's, whether they are in association with the preceeding form in epithelial-like tumors, or the main component in sarcomatous-like tumors. Since the absence of fibroblastoid MCC's would eliminate the diagnosis of mesothelioma, patient and careful search for these cells must be done in all pleural tumors with a unique differentiation (epithelial-like or sarcomatouslike). This justifies the need for electron microscopy in the diagnosis of these pleural tumors: for this reason, pleural biopsies should routinely be embedded for possible future ultrastructural examination.

Idiopathic pulmonary hemorrhage. Ultrastructural and mineralogic study

A nine-year-old girl was hospitalized because of hypoxemia and anemia. Antibasement-membrane antibodies were present in the serum, but there was no renal involvement suggestive of Goodpasture's glomerulonephritis. Biopsy of the lung showed pulmonary hemosiderosis. In ultrastructural analysis, no lesion of the alveolar basement membrane or capillary endothelial cells was found; however, ferritin-looking deposits were present on alveolar basement membranes and the elastic lamina of arterioles and venules. Mineralogic studies showed these deposits to be made of iron and calcium (this latter element was probably precipitated on altered basement membranes or elastic lamina). Hemosiderin inclusions in the macrophages contained iron but no detectable calcium.

Pleural immunocytoma with Waldenström's macroglobulinemia. Ultrastructural study of one case

Waldenström's macroglobulinemia was diagnosed in a patient suffering from recurrent lymphocytic pleurisy. Ultrastructural studies of the pleura showed the features of Lennert's lymphoplasmacytoid immunocytoma. Computerized assisted tomodensitometry revealed a retroperitoneal growth surrounding the right kidney and squeezing the thoracic lymphatic duct.

Nevus lipomatosus cutaneous superficialis. An electron microscopic study of four cases

Four cases of nevus lipomatosus cutaneous superficialis were studied under the electron microscope. The results showed the vascular origin of the fat cell and differentiation of young fat cells into mature fat cells. The findings are comparable to those observed in fetal adipogenesis.

[Cutaneous argyria: an electron microscopic study of four eases with microanalysis X study of one case (author's transl)]

This study was done in order to follow the fate of silver in the dermis of chronic argyria. Silver was easily recognizable in the tissue as irregular aggregates of elementary granules round or ovoid in shape, ranging from 30 to 40 mm in size. The microanalysis X showed that the metal was bound with sulfur. In the cases of recent intoxication, the main location of silver was intracellular: the granules were found in the lysosomes as elementary particle or as dense heterogen bodies. In the cases where intoxication had been stopped a long time ago, silver was found either on fibrillar component of the connective tissue or in the basal material of sweat glands. The results show that silver is at first phagocytized by macrophages but this cell is unable to perform complete degradation of the silver salt or metal. Then silver is found on connective fibers where it remains on sulfated glycoproteins.