Human dermal mast cells contain and release tumor necrosis factor alpha, which induces endothelial leukocyte adhesion molecule 1

Tumor necrosis factor alpha (TNF-alpha) is a proinflammatory cytokine that mediates endothelial leukocyte interactions by inducing expression of adhesion molecules. In this report, we demonstrate that human dermal mast cells contain sizeable stores of immunoreactive and biologically active TNF-alpha within granules, which can be released rapidly into the extracellular space upon degranulation. Among normal human dermal cells, mast cells are the predominant cell type that expresses both TNF-alpha protein and TNF-alpha mRNA. Moreover, induction of endothelial leukocyte adhesion molecule 1 expression is a direct consequence of release of mast cell-derived TNF-alpha. These findings establish a role for human mast cells as "gatekeepers" of the dermal microvasculature and indicate that mast cell products other than vasoactive amines influence endothelium in a proinflammatory fashion.

Visual acuity changes throughout adulthood in normal, healthy eyes: seeing beyond 6/6

There are many useful longitudinal and cross-sectional epidemiological studies of how visual acuity (VA) deteriorates with age. However, few studies have evaluated age-related VA changes in normal, healthy eyes. Data from three previous studies that included VA measurements taken with logMAR charts from subjects with normal, healthy eyes were collated and additional data from 42 subjects were added. This provided VA results from 223 subjects (age range 18 to 80 years). Mean logMAR VA improved from -0.13 (Snellen equivalent 6/4.5) in 18- to 24-year-olds to -0.16 (Snellen 6/4(-1)) in 25- to 29-year-olds and then gradually became worse with age to a mean value of -0.02 (Snellen 6/6+1) for subjects over 75 years of age. The inadequacy of 6/6 as a norm value of VA is illustrated. The data show VA levels far superior to the data from the standard references of Pitts (1982) and Weale. (1975, 82) We suggest that this is because we used logMAR charts (providing nontruncated data), the subject's optimal refractive correction (rather than habitual) and strict exclusion criteria ensuring that only subjects with normal, healthy eyes were recruited for the studies.

Melanosomes are a primary target of Q-switched ruby laser irradiation in guinea pig skin

The specific targeting of melanosomes may allow for laser therapy of pigmented cutaneous lesions. The mechanism of selective destruction of pigmented cells by various lasers, however, has not been fully clarified. Black, brown, and albino guinea pigs were exposed to optical pulses at various radiant exposure doses from a Q-switched, 40 nsec, 694 nm ruby laser. Biopsies were analyzed by light and electron microscopy (EM). Albino animals failed to develop clinical or microscopic evidence of cutaneous injury after irradiation. In both black and brown animals, the clinical threshold for gross change was 0.4 J/cm2, which produced an ash-white spot. By light microscopy, alterations appeared at 0.3 J/cm2 and included separation at the dermoepidermal junction, and the formation of vacuolated epidermal cells with a peripheral cytoplasmic condensation of pigment. By EM, enlarged melanosomes with a central lucent zone were observed within affected epidermal cells at 0.3 J/cm2. At 0.8 and 1.2 J/cm2, individual melanosomes were more intensely damaged and disruption of melanosomes deep in the hair papillae was observed. Dermal-epidermal blisters were formed precisely at the lamina lucida, leaving basal cell membranes and hemidesmosomes intact. Possible mechanisms for melanosomal injury are discussed. These observations show that the effects of the Q-switched ruby laser are melanin-specific and melanin-dependent, and may be useful in the selective destruction of pigmented as well as superficial cutaneous lesions.

Neural contribution to spatiotemporal contrast sensitivity decline in healthy ageing eyes

Contrast sensitivity thresholds were measured over a range of spatial and temporal frequencies in both a group of young and older observers. Results demonstrate a significant reduction in contrast sensitivity of the older age group at all but the lowest combinations of spatial and temporal frequencies investigated. The senile miosis and reduced optical transmission of the older eye was then mimicked using the younger observers as subjects. This combined effect of reducing retinal illumination produced no significant change in sensitivity. These findings are discussed in terms of neural loss within the visual pathways with increasing age.

Establishment of a murine model of malignant mesothelioma

Malignant mesothelioma (MM) is an aggressive tumour of the serosal cavities which is associated with previous asbestos exposure and is generally found to be resistant to conventional forms of therapy. Adequate scientific and clinical assessment of this disease has been severely limited by the relatively low incidence of mesothelioma and the lack of representative cell lines and animal models. The purpose of this study was to develop an asbestos-induced murine model of MM both as an in vivo-passaged malignancy and as in vitro-established cell lines. Such a model system would be invaluable for use in the study of various cellular, molecular and genetic aspects of the disease, and for the pre-clinical evaluation of potential therapeutic agents. BALB/c and CBA mice were injected intraperitoneally with crocidolite asbestos. Seven to 25 months after exposure, 35% of the mice developed mesothelioma (5 BALB/c, 9 CBA), as determined by standard cytological and histological parameters. From these primary tumours, 12 continuously growing cell lines (5 BALB/c, 7 CBA) were established in culture. All have been confirmed as mesothelioma by cytological and ultrastructural (electron microscopy) analyses. These lines have been in culture for 7 to 24 months and have achieved passages above 32 (range 32 to 106). As in the human disease, the murine mesothelioma lines vary in their morphology and growth rates (doubling times ranging from 14 to 30 hr). All cell lines produced tumours when injected into syngeneic mice.

Reactive mesothelial hyperplasia vs mesothelioma, including mesothelioma in situ: a brief review

In biopsy tissue, discrimination between reactive mesothelial hyperplasia and epithelial mesothelioma can pose a major problem for the surgical pathologist. Confidence in the diagnosis is often proportional to the amount of tissue available for study and depends largely on findings of invasion and the extent and cytologic atypia of the lesion, because there is no marker specific for the mesothelium and that discriminates consistently among normal, hyperplastic, and neoplastic mesothelial tissue. Therefore, mesothelioma in situ is diagnosable only when invasive epithelial mesothelioma is demonstrable in the same specimen, in a follow-up biopsy specimen, or at autopsy. Comparison of 22 cases of mesothelioma in situ that fulfill these requirements for diagnosis with 141 invasive mesotheliomas and 78 reactive mesothelioses indicates that strong linear membrane-related labeling for epithelial membrane antigen and silver-labeled nucleolar organizer region-positive material that occupies 0.6677 microm2 or more of the nucleus in an atypical in situ mesothelial lesion of the pleura are found consistently in neoplastic mesothelial cells. Although these findings may engender suspicion of mesothelioma in situ in high-risk persons, the criteria for diagnosis of pure mesothelial lesions of this type are still under study. Mesothelioma in situ should be considered proved only when unequivocal invasion is identified in a different area of the pleura or at a different time; a diagnosis of pure mesothelioma in situ should not be made in patients not exposed to asbestos.

Diagnosis of pleural malignant mesothelioma in life--a practical approach

This review documents a practical approach to the pathological diagnosis of pleural malignant mesothelioma based on the closed needle biopsy and effusion cytology, thus avoiding the need to resort to open surgery. Tissue diagnosis is often difficult, and the pathologist's opinion may be influenced by a consideration of three factors: the clinical setting; the adequacy and availability of specimens; and the criteria for assessment and interpretation of these. The level of confidence with which a tissue diagnosis of mesothelioma can be established using limited material depends on there being an appropriate clinical background including a history of asbestos exposure. Without this, the diagnosis should be a qualified or tentative one. For an adequate tissue sample to be obtained, the closed needle biopsy procedure is best performed by an experienced operator. All aspirated pleural effusions should be forwarded for cytological evaluation. In addition to conventional morphological studies, adequate samples permit ancillary tests to be carried out. A combined interpretive approach utilizing both histopathology and cytology is recommended in order to increase the accuracy of the diagnosis.

Mesothelial healing: morphological and kinetic investigations

By using structural, kinetic and irradiation techniques it is possible to show that mesothelial healing is a local event. Initially, macrophages occupy the surface of a wound on the injured visceral layer, while mesothelial proliferation proceeds at the edge of the wound and the opposing parietal surface. Fibrin is formed on the wound surface within 24 h, even in the absence of much haemorrhage. Mesothelial ingrowth begins with isolated cells migrating from the wound edge as well as from the serosal surface apposing the wound where mesothelial cells are actively replicating. The cells presumably slide over a bridge of fibrin and macrophages, a process likely to be enhanced by the serosal fluid. Early colonization by macrophages results in the removal of debris and probably prevents the formation of adhesions during mesothelial restoration.

Intercellular adhesion molecule expression in the evolving human cutaneous delayed hypersensitivity reaction

Intercellular adhesion molecule-1 (ICAM-1), putatively expressed by antigen-presenting or target skin cells, is a ligand for the lymphocyte function-associated antigen (LFA-1) present on circulating lymphocytes. Immunohistochemistry of normal adult human skin using monoclonal antiserum to ICAM-1 demonstrated focal reactivity restricted to endothelium lining the dermal microvasculature. Delayed hypersensitivity responses elicited with dinitrochlorobenzene in the skin of the same subject were evaluated sequentially over a 96 h period using immunohistochemical and ultrastructural techniques. The first alteration observed consisted of mast cell degranulation within perivenular foci in the superficial dermis at 4 h after antigen challenge. Sparse superficial perivascular T-cell infiltrates were present by 24 h. Progressive staining for ICAM-1 was observed in microvascular endothelium and in dermal dendritic cells between 24 and 48 h. ICAM-1 expression was documented focally within the lower epidermis at 48 h and diffusely within the lower and upper epidermal layers at 96 h. ICAM-1 expression by keratinocytes was consistently associated with T-cell migration into the epidermis, whereas migration was never observed in the absence of ICAM-1 reactivity. Immunoelectron microscopy confirmed ICAM-1 to be exclusively present on endothelial cells, dermal dendritic cells, mononuclear cells, and keratinocytes, and permitted characterization of the patterns of membrane reactivity. ICAM-1 expression by epidermal cells appears to be closely linked to the progressive migration of T cells from the dermis into the epidermis that characterizes cutaneous delayed hypersensitivity.

Establishment and characterization of five human malignant mesothelioma cell lines derived from pleural effusions

Malignant mesothelioma (MM) is an aggressive tumour of the serosal cavities which is associated with exposure to asbestos. Studies of this tumour have been limited by a paucity of well-characterized human MM cell lines. In this study, 5 human MM cell lines were established from pleural effusions of patients with this malignancy. All 5 patients were males with known crocidolite asbestos exposure, who had received no treatment for their disease and in whom the diagnosis was confirmed by cytology, histology and electron microscopy (EM). These lines have been in culture from 11 to 25 months, and all of them for more than 18 passages. The appearance of the cells in culture was extremely varied; in 3 of the lines they were spindle-shaped with few vacuoles (JU77, LO68 and ONE58); in 1 line they had a thick, stellate shape with vacuoles (NO36) and in 1 they were very pleomorphic in both shape and size with irregular membranes and numerous vacuoles [DeH128 (M)]. Upon reaching confluence, cells in 3 of the 5 lines assumed the cobblestone-like pattern characteristic of epithelial-type cells, whereas in the other 2 (LO68 and ONE58) they remained spindle-shaped. All 5 lines demonstrated a loss of contact inhibition (i.e., piling) at confluence. Minimum doubling times varied significantly from 18 hr (JU77) to more than 30 hr [DeH128 (M)]. Cytological examination showed characteristic mesothelial/mesothelioma morphology, and epithelial membrane antigen (EMA) and cytokeratin were demonstrated in cells from all 5 lines. These cells lacked CEA and epithelial mucin. The presence of cell junctions, glycogen and numerous long, thin, branching microvilli was readily demonstrable by EM. All lines had abnormal karyotypes, with the modal chromosome number varying from 40 to 80. Variable chromosome numbers, numerous structural rearrangements and unrecognizable marker chromosomes were readily observed; however, the only consistent change seen was del 6q21 in 4 of the 5 lines. The establishment of these 5 cultured human MM cell lines now provides an opportunity for comparative study of several aspects of the biology of MM in vitro as well as screening new treatment modalities.

Contrast sensitivity and glare sensitivity changes with three types of cataract morphology: are these techniques necessary in a clinical evaluation of cataract?

LogMAR visual acuity, contrast sensitivity and glare sensitivity measurements were made on 39 eyes of 18 cataractous subjects and compared against normative data. Only cataracts of one of the main three morphological cataract types were used--cortical, nuclear and posterior subcapsular. Results indicate that contrast sensitivity decline with cataract is an intermediate and high spatial frequency loss. For nuclear and cortical cataracts with a LogMAR visual acuity of less than 0.5 (Snellen equivalent better than 6/18), there was no loss of contrast sensitivity at the lowest spatial frequency (1 c/deg). For posterior subcapsular cataracts, low spatial frequency contrast sensitivity loss did occur but was unrelated to visual acuity. Glare sensitivity increased for all cataract types. This was related to visual acuity for both cortical and nuclear cataracts but was not for the posterior subcapsular type. It was concluded that contrast and glare sensitivity measurements are a useful part of the assessment of visual function in patients with posterior subcapsular cataract.

A comparison of word recognition and reading performance in foveal and peripheral vision

Word recognition thresholds and rapid serial visual presentation (RSVP) reading rates for both unrelated words and meaningful sentences were examined across the visual field. Both word recognition thresholds and RSVP reading rates for unrelated words can be equated across the visual field by an increase in size scale. RSVP reading rates for meaningful sentences cannot be equated across the visual field, with the fovea demonstrating a qualitative superiority over the periphery, irrespective of scale. The results suggest that the early visual machinery which underlies word recognition is the same across the visual field apart from a change in scale, whilst the periphery is qualitatively inferior to the fovea at interpreting sentences with meaning.

The mesothelium: its fibrinolytic properties

We have investigated the fibrinolytic properties of the mesothelium by developing a test system in which standard tissue samples can be assessed in a comparative and semi-quantitative manner. The problem whether plasminogen activators were generated by the mesothelium itself or were transported from a subserosal site was also studied. A standard system was developed by using a uniform gelatin disc to obtain a monolayer imprint of mesothelium and subsequently incorporating several of these samples on a fibrin plate. Pure cultures of mesothelial cells were able to induce fibrinolysis.

Medullary carcinoma of the thyroid: accuracy of diagnosis of fine-needle aspiration cytology

BACKGROUND

A preoperative diagnosis of medullary carcinoma of the thyroid (MCT) allows for the investigation of associated multiple endocrine neoplasia/ pheochromocytoma, and definitive surgery without the need for frozen section. Criteria for cytodiagnosis are well known but variable patterns of presentation may cause diagnostic difficulty.

METHODS

This study examines the accuracy of cytodiagnosis and the value of ancillary tests in 17 patients seen between 1976 and 1997. Nine patients underwent thyroid gland aspirations, five patients underwent fine-needle aspiration (FNA) of the thyroid and cervical lymph nodes, and three patients underwent cervical lymph node aspiration alone. Electron microscopy (EM) of aspirated material was performed in nine cases and immunocytochemistry in two cases.

RESULTS

In all cases the diagnosis was suggested by FNA. In four cases, diagnosis and management were based on cytology alone. EM of FNA material was confirmatory in nine cases, two of which also showed positive calcitonin immunocytochemistry. In three cases the diagnosis was not proven until surgical resection, and in one case FNA confirmed lymph node metastasis in known MCT. Frozen section in five patients did not change the level of diagnostic confidence over the FNA diagnosis in any case. In four other thyroid tumors (one Hürthle cell follicular carcinoma, two anaplastic carcinomas, and one hyperplastic nodule) MCT was suspected in the FNA differential diagnosis but later excluded. In the Hürthle cell tumor immunoperoxidase staining was positive for calcitonin and in one anaplastic carcinoma, a neuroendocrine phenotype was suggested. In the latter case, additional EM excluded MCT.

CONCLUSIONS

Although correct diagnosis is made by cytology in the majority of instances, other tumors may show cytologic findings similar to MCT. EM of FNA material was found to be the most definitive method of proving or excluding MCT. Immunocytochemistry may be misleading for rarely performed tests.

Effect of a cataract simulation on clinical and real world vision

AIMS/BACKGROUND

Many reports have indicated that some patients with cataract can retain good visual acuity but complain of significant visual problems. This is the first in a series of papers trying to determine what causes these symptoms and whether other clinical tests can predict the real world vision loss.

METHODS

The effect of a cataract simulation with a similar angular distribution of light scatter as real cataract on clinical (visual acuity, contrast sensitivity, and disability glare) and real world vision (face recognition, reading speed, and mobility orientation) was investigated.

RESULTS

The simulation had a relatively small effect on visual acuity (6/6 with the simulation), but much larger effects on contrast sensitivity and low contrast acuity with and without glare. The simulation had no effect on high luminance and high contrast real world tasks, such as mobility orientation in room light and optimal reading speed. A small, but significant deterioration was found for the slightly lower contrast task of face and expression recognition. However, under low luminance conditions, substantial defects in mobility orientation were obtained (despite 6/6 acuity).

CONCLUSIONS

Although the relative effect of the cataract simulation on acuity and contrast tasks is not typical of the average cataract, it can be found in those cataract patients with visual problems despite good visual acuity. This corroborates the suggestion that it is large amounts of wide angle light scatter (forward and/or backward) which are at least partly responsible for visual disability in cataract patients with good visual acuity. A patient's reported visual disability may depend on the percentage of time he or she spends under low contrast and/or low luminance conditions, such as walking or reading in dim illumination, and walking or driving at night, in fog, or heavy rain.

The mesothelium and its reactions: a review

The origins, nature, and reactions of the mesothelium have intrigued investigators for over 100 years. Recently, the use of sophisticated techniques has clarified earlier impressions of its development, structure, and function. The structure of mesothelium reflects its functional properties, its long slender microvilli entrapping a layer of glycosoaminoglycans, providing a frictionless free surface between the parietal and visceral serosa. Transport requirements are met by various surface modifications and both inter- and intra-cellular mechanisms occur. The presence of stomatal openings in the mesothelial membrane has been established, and they may have a major role to play in the movement of cells to and from the serosal cavities. In addition, mesothelial cells can respond to situations of increased functional demand and during the course of inflammation, the mesothelium's fibrinolytic properties are of major importance in preventing the formation of adhesions and the enhancement of healing. Of all the unanswered questions the most significant is the nature, localization, and potentialities of mesothelial precursors. A mesodermal origin is readily acknowledged, but the healing process of damaged mesothelium is less clear. It seems probable that "mature" mesothelium is one source of cell renewal, but mesenchymal cells located in the submesothelial serosa are also strong contenders. Neoplastic mesothelium can adopt a spectrum of histological appearances, reflecting its mesodermal origins. In fact, overacceptance of this concept has erroneously led to the classification of other neoplasms arising in the serosal area as mesotheliomas. Although the ocogenic sequence is still obscure, asbestos is recognized as the major etiologic agent in malignant mesotheliomas. In 1955, Hartwell described differing impressions of the peritoneum as seen through the eyes of an anatomist, an histologist, and a surgeon. In this review on the mesothelium we have attempted to unravel some of its complexities as viewed by embryologists, electronmicroscopists, cell biologists, pathologists, and oncologists.

The systemic administration of gamma interferon inhibits collagen synthesis and acute inflammation in a murine skin wounding model

The ability of gamma interferon (IFN-gamma) to affect cutaneous collagen synthesis in vivo was examined in a murine wounding model. Reproducible areas of full-thickness skin necrosis were produced by argon laser radiation. Mice received recombinant murine IFN-gamma (rMuIFN-gamma) (8.7 X 10(3) units/hr) over 14 d via osmotic pumps implanted subcutaneously or intraperitoneally. At 14 and 21 d after wounding, there was less fibrous tissue in healing scars of treated animals as determined by light and transmission electron microscopy. Associated with the decrease in connective tissue was an increase in the acid mucopolysaccharide content of healing scars, which was largely hyaluronate. Quantitative image analysis of electron micrographs confirmed that less collagen was present in healing scars of animals receiving rMuIFN-gamma. The mean cross-sectional area of collagen fibers was smaller in specimens from treated mice, but no difference was seen in the size of collagen fibrils. The time required to obtain full skin closure was also delayed 23%-27% in treated animals. Using this injury model, we also found that rMuIFN-gamma significantly reduced the degree of perilesional erythema surrounding the laser injury sites and, in the first 6 d after wounding, the degree of polymorphonuclear infiltrate present histologically at lesional sites. Indeed, rMuIFN-gamma also decreased the cutaneous accumulation of neutrophils induced by known proinflammatory mediators, such as interleukin 1 and activated serum. Thus, systemically administered IFN-gamma not only down-regulates collagen synthesis in the skin but also modulates in a previously unrecognized manner: neutrophil accumulation at sites of tissue injury in vivo.

Mesothelial regeneration is not dependent on subserosal cells

It has been proposed that after mesothelial injury, resident cells within the subserosal connective tissue proliferate, differentiate, and migrate to the serosal surface. The aim of this study was to examine the temporal and spatial changes of proliferating cells in a murine model of testicular mesothelial healing and assess the potential of submesothelial cells to reconstitute the damaged mesothelium. Histology and autoradiography were employed to determine the number of cells within the submesothelial connective tissue, as well as the proportion of cells undergoing DNA synthesis on and beneath the injured serosa. Mesothelial cells surrounding the wound demonstrated maximal DNA synthesis 48 h after injury (27. 82+/-5.64% SEM, compared with 0.17+/-0.16% (3)H-TdR labelled cells for resting mesothelium), whereas a significant increase in proliferating submesothelial cells was not seen until day 4 post-injury (7.79+/-3.31% compared with 0.85+/-0.64% (3)H-TdR labelled cells at day 2). Furthermore, this small number of dividing submesothelial cells must include cells other than the proposed mesothelial precursors, indicating a very low proportion of precursor cells in the submesothelial cell population. As large numbers of mesothelial cells were seen at the wound centre by 3-4 days after injury, it is unlikely that submesothelial cells contributed significantly to the repopulation of the injured mesothelium. It is hypothesized that regenerating mesothelium is more likely to originate from the surrounding uninjured mesothelial cell population.

Differences in the legibility of letters at contrast threshold using the Pelli-Robson chart

One disadvantage of using high-contrast letters as test objects when measuring visual acuity is the fact that they are not of equal legibility. A number of charts are now commercially available that assess contrast sensitivity using letter targets. This study attempted to assess the legibility of letters at contrast threshold on the Pelli-Robson letter contrast sensitivity chart by determining the percentage of correct responses for each of the ten Sloan letters at contrast threshold. Results of 493 contrast sensitivity measurements taken in optometric practice indicated that there is a definite difference in legibility between letters at contrast threshold as for letters at acuity threshold. The data suggest that the probability of correctly identifying two out of a group of three letters at threshold on the Pelli-Robson chart varies between 67% and 97% due to letter type alone. Because of the very regular and pronounced miscalling of the letter C as an O, we suggest that this should be accepted as a correct call during threshold measurements on the Pelli-Robson chart. This helps to balance the legibility of different groups of letters.

Modelling of orientation discrimination across the visual field

In many visual tasks thresholds can be made equal across the visual field by increasing the size of peripherally presented stimuli by appropriate magnification. The parameter E2 represents the eccentricity at which foveal stimulus size must double in order to maintain performance equivalent to that at the fovea. We measured orientation discrimination for a set of line sizes at various eccentricities. Thresholds were successfully scaled by applying a scaling function estimated by a technique that requires no prior assumptions regarding the size of peripherally presented stimuli. E2 of 1.95 deg was found for orientation discrimination. From our results we were able to develop a single equation which predicts orientation discrimination thresholds for an average observer over a range of different eccentricities and line lengths.

The use of epithelial membrane antigen and silver-stained nucleolar organizer regions testing in the differential diagnosis of mesothelioma from benign reactive mesothelioses

BACKGROUND

The accurate diagnosis of pleural lesions obtained from small closed biopsy is difficult. As yet there is no single reliable test to distinguish between malignant and benign mesothelial tissue.

METHODS

Immunostaining of epithelial membrane antigen (EMA) and the quantitation of silver stained nucleolar organizer regions (AgNORs) each were applied to benign and malignant histologic sections of pleural and peritoneal biopsies. The usefulness of these stains was tested both individually and in combination in the diagnosis of epithelial malignant mesothelioma.

RESULTS

One hundred and three of the 141 malignant lesions (73%) were immunoreactive for EMA but only 3 of the 73 benign lesions (4%) reacted equivocally, and none positively. The average count of AgNORs/cell in malignant lesions (n = 80) was elevated compared with benign cases (n = 26), but a significant overlap was exhibited in the AgNOR count and this form of analysis was considered to be of little value in distinguishing benign from malignant mesothelial processes. Much less overlap was observed when the average AgNOR area was measured. By using the maximum benign AgNOR area of 0.6677 microm2 as the upper threshold, 51 cases (63.8%) were identified as malignant; the test demonstrated 100% specificity and 63.8% sensitivity. By combining the EMA and AgNOR results, 76 of 80 of the malignant mesothelioma cases (95%) tested positive for at least 1 of the tests with no false-positive results identified.

CONCLUSIONS

This study confirms the usefulness of EMA in diagnosing malignant and benign mesothelial lesions, and demonstrates the enhanced diagnostic value of combining EMA immunoreaction with the average area of AgNOR per cell, thereby increasing sensitivity in the diagnosis of epithelial malignant mesothelioma.

Detection of anticentromere antibodies using cloned autoantigen CENP-B

A solid-phase enzyme-linked immunosorbent assay has been established using a cloned fusion protein, CtermCENP-B [beta-gal], as antigen. The fusion protein carries the major epitope of CENP-B, the major centromeric autoantigen. The enzyme-linked immunosorbent assay was more sensitive than immunofluorescence techniques in detecting anticentromere antibodies in patients with scleroderma or Raynaud's disease, and was weakly positive in 3% of normal controls and in 3% of 70 patients with other connective tissue diseases.

Alveolitis of pulmonary asbestosis. Bronchoalveolar lavage studies in crocidolite- and chrysotile-exposed individuals

Bronchoalveolar lavage (BAL) findings in 27 individuals with crocidolite- or chrysotile-induced asbestosis were compared to BAL findings in 29 unexposed control subjects. Alveolitis, defined as an increase in the proportions and/or absolute numbers of inflammatory cells present in BAL fluid compared to values in control subjects, was present in 26 (96 percent) subjects with asbestosis. Most exhibited a neutrophil-eosinophil alveolitis, with neutrophil proportions increased to 7.4 +/- 0.7 percent and eosinophil proportions increased to 2.2 +/- 0.4 percent, compared to 2 +/- 0.5 percent and 0.4 +/- 0.01 percent, respectively, in control subjects (p less than 0.01 for both neutrophils and eosinophils). An increase in the total number of neutrophils and eosinophils per ml of lavage fluid was also seen (neutrophils 23 +/- 5 and eosinophils 13 +/- 4 per ml; p less than 0.05 compared to control subjects). Severity of the alveolitis, defined by the neutrophil or eosinophil proportions, was independent of a history of exposure to cigarette smoke. The pattern and severity of alveolitis in crocidolite- and chrysotile-induced asbestosis were similar. There was a significant correlation between duration of exposure to asbestos and neutrophil proportions (p less than 0.01). No significant difference in the severity of the alveolitis was observed between individuals with radiologic and physiologic evidence of asbestosis compared to those with asbestos exposure and crackles alone, suggesting that, in asbestosis as in other chronic interstitial lung diseases, radiologic and physiologic parameters do not reflect the severity of the alveolitis. This study demonstrates that a neutrophil-eosinophil alveolitis is present in individuals with crocidolite- and chrysotile-induced asbestosis, that this alveolitis is independent of cigarette smoking, and that the severity of the BAL changes is not reflected in radiologic and physiologic changes.