Mycoplasma felis pleuritis in two show-jumper horses

Mycoplasma felis was identified as the cause of acute pleuritis in 2 show-jumping horses. The pleural exudate was proteinaceous, contained large numbers of neutrophils, and had a markedly increased lactate concentration. M. felis was isolated in pure culture from pleural fluid. Rising serum antibody titers to M. felis as well as a precipitous decline in titers to equine influenza virus were demonstrated in both horses. Pleural effusion in both horses and a pneumothorax detected in one of the horses resolved following a single drainage of pleural fluid and intravenous fluid, antibiotic, and analgesic therapy.

Comparison of the peritoneal cells elicited by oxidized regenerated cellulose (Interceed) and expanded polytetrafluoroethylene (Gore-Tex Surgical Membrane) in a murine model

OBJECTIVE

The peritoneal fluid cell responses to the available barriers used to prevent postoperative adhesions, oxidized regenerated cellulose (interceed) and expanded polytetrafluoroethylene (Gore-Tex Surgical Membrane), were compared.

STUDY DESIGN

Oxidized regenerated cellulose and expanded polytetrafluoroethylene were inserted into the peritoneal cavity of mice and the peritoneal fluid cell number, differential cell count, morphologic type, adherence to plastic, and phorbol-12,13-myristate acetate-stimulated hydrogen peroxide production evaluated. Peritoneal fluid cell attachment to oxidized regenerated cellulose and expanded polytetrafluoroethylene was evaluated by electron microscopy.

RESULTS

Oxidized regenerated cellulose promptly elicited increased numbers of large, morphologically activated peritoneal fluid macrophages that adhered more rapidly and produced more hydrogen peroxide than controls. Expanded polytetrafluoroethylene gradually increased the number of normal-appearing peritoneal fluid macrophages with increased hydrogen peroxide production but normal adherence. Macrophages rapidly attached to both materials in vivo, with oxidized regenerated cellulose being rapidly degraded.

CONCLUSION

Oxidized regenerated cellulose, to a greater extent than expanded polytetrafluoroethylene, elicits an acute peritoneal fluid inflammatory exudate in the mouse, which may contribute to the oxidized regenerated cellulose-induced peritoneal injury and de novo adhesions observed in this model.

The utility of ancillary techniques in effusion cytology

We believe that, in general, immunocytochemical studies when used as a panel are the most helpful of the ancillary techniques in the workup of a difficult effusion cytology case. Routine histochemical stains for mucin should also be employed due to their low cost and simplicity, but suffer from lack of sensitivity and specificity. EM examination is especially helpful in the differentiation of metastatic carcinoma from mesothelioma, but lacks specificity due to overlapping ultrastructural features, and is both costly and labor intensive. Immunophenotyping by flow cytometry is useful in the workup of problematic lymphoid proliferations, but DNA analysis by flow cytometry is not useful as a screening technique. Fortunately, most effusion cytology cases will not need the use of ancillary studies, since the diagnosis will be accurately rendered based on the cytomorphologic findings. However, occasional cases will benefit from the use of specific ancillary studies, which can aid in making an accurate, specific, and rapid diagnosis in an otherwise challenging case.

Promotion of murine antitumor activity by prothymosin alpha treatment: I. Induction of tumoricidal peritoneal cells producing high levels of tumour necrosis factor alpha

The effect of prothymosin alpha (ProT alpha) on the survival of DBA/2 mice inoculated with syngeneic tumour cells was studied. DBA/2 mice inoculated intraperitoneally (i.p.) with 2 x 10(5) syngeneic leukaemic L1210 cells developed ascites within 8-12 days and died 10-14 days later. Treatment with ProT alpha consistently inhibited the development of ascites in 20% of the treated animals and prolonged the survival of 40%-60% of the animals up to 70 days. The most effective treatment schedule of ProT alpha was 300 ng/mouse given i.p. at 2-day intervals for 3 weeks followed by a rest period of 7 days, prior to tumour cell inoculation. Peritoneal exudate (PE) cells collected from mice treated with the optimal dose of ProT alpha produced, in the absence of exogenous stimulus, six- to eightfold higher levels of tumour necrosis factor alpha (TNF alpha) than PE cells from control mice. Furthermore these cells exhibited cytotoxic activity against several tumour cell lines including the syngeneic L1210, the TNF-insensitive P815 mastocytoma, the human MOLT-4 lymphoblastic leukaemia, as well as the murine TNF-sensitive L929 fibroblast cell line. Kinetic studies revealed that both production of TNF alpha and tumoricidal activity peaked 7 days after the last injection of ProT alpha and were maintained at high levels over a period of 1 month. Injections with 150 ng ProT alpha slightly improved the survival of mice whereas higher (500 ng and 1000 ng) doses of ProT alpha and a wide range of thymosin alpha 1 doses remained without any effect. PE cells collected from these mice produced extremely low levels of TNF alpha and exhibited negligible tumoricidal activity. Our data demonstrate that ProT alpha has a protective effect in vivo against the growth of adoptively transferred tumour cells and suggest that this effect is, at least in part, mediated by ProT alpha-activated PE cells. These cells were demonstrated to produce high levels of TNF alpha in vitro and to exhibit activity against both TNF-sensitive and TNF-resistant cell lines.

Role of endothelial-leukocyte adhesion molecule 1 (ELAM-1) in neutrophil-mediated lung injury in rats

Two murine monoclonal antibodies (CL-3 and CL-37, both F(ab')2) to human endothelial-leukocyte adhesion molecule-1 (ELAM-1) were found to react immunohistochemically with rat pulmonary artery endothelial cells that had been pretreated with tumor necrosis factor (TNF alpha). CL-3, but not CL-37, blocked in vitro adherence of neutrophils to TNF alpha-treated endothelial cells and the killing of TNF alpha-treated rat endothelial cells by phorbol ester activated neutrophils. In rats treated systemically with CL-3, there was a 70% reduction in accumulation of neutrophils in glycogen-induced peritoneal exudates. Treatment of animals with CL-37 anti-ELAM-1 did not reduce neutrophil accumulation under the same conditions. When IgG immune complex deposition was induced in dermis and in lungs of rats, treatment with CL-3 anti-ELAM-1 markedly reduced vascular injury as measured by changes in vascular permeability (leakage of 125I-albumin) and hemorrhage (extravasation of 51Cr-red blood cells). The protective effects of CL-3 anti-ELAM-1 were related to greatly diminished recruitment of neutrophils (as assessed morphologically, by tissue extraction of myeloperoxidase, and by retrieval, via bronchoalveolar lavage, of neutrophils from lung). CL-37 had no protective effects in vivo after deposition of immune complexes in lung. Using either CL-3 or CL-37 anti-ELAM-1, immunohistochemical analysis of lungs undergoing IgG immune complex-induced injury revealed a striking upregulation of ELAM-1 in the lung vasculature (venules and interstitial capillaries), with a peak intensity developing between 3 and 4 h after deposition of immune complexes in lung. Vascular beds of spleen, liver, and kidney failed to show upregulation of ELAM-1 under these same conditions. The immunohistochemical reactivity of rat lung was abolished if the anti-ELAM-1 preparation was first absorbed with monolayers of human umbilical vein endothelial cells that had been pretreated with TNF alpha. Untreated human endothelial cells failed to cause loss of lung reactivity of the anti-ELAM-1 preparation. These data indicate that ELAM-1 is upregulated in the pulmonary vasculature of rats during deposition of immune complexes and that ELAM-1 appears to play an obligate role in the recruitment of neutrophils.

The effects of (R)-N-(1-methyl-2-phenylethyl) adenosine (L-PIA), a standard A1-selective adenosine agonist on rat acute models of inflammation and neutrophil function

L-PIA, a standard A1-selective adenosine agonist, was evaluated orally in carrageenan (CRG)- and reverse passive arthus-pleurisy. White blood cell (WBC) and exudate accumulation were assessed four hours after induction of the inflammatory response. L-PIA inhibited WBC accumulation in both models with ID50's of 4.37 and 4.42 mg/kg, respectively. In contrast, exudate was inhibited by L-PIA only in the CRG pleurisy model (ID50 = 1.01 mg/kg). In mechanistic studies, L-PIA reversed the drop in circulating neutrophil count which occurred within 15 minutes after CRG injection, suggesting that L-PIA may inhibit adhesion of the cells to the endothelium. The effects of L-PIA on several parameters of rat neutrophil function were determined. Enzyme release, O2-, TXB2, and LTB4 production were monitored in response to FMLP and opsonized zymosan (SOZ) stimulation. At high concentrations, L-PIA had a mild inhibitory effect on O2- release in response to FMLP and had a moderate effect on arachidonic acid metabolite production in response to both stimuli. The other response were unaffected. These results suggest that L-PIA may prevent diapedisis or neutrophil adhesion to the endothelium, but has a minimal effect on enzyme release, O2-, LTB4 and TXB2 production.

Effect of capsaicin on carrageenan-induced inflammation in rat pleurisy and exudate substance P level

Injection of 2.5 mg of lambda-carrageenan into the rat pleural cavity resulted in a time-dependent increase in pleural exudate substance P (SP) levels up to 24 hr. Synergistic increases in the exudate formation were observed when a sub-optimal quantity of carrageenan was injected with SP. Pre-treatment of rats with capsaicin at 50 and 100 mg/kg s.c. daily for one week prior to the induction of pleurisy blocked the increase in exudate volume and SP levels when compared to that normally detected after carrageenan injection. These results suggest that inhibition of SP production may improve inflammatory conditions.

Mechanisms in neutrophil priming: characterization of the oxidative response induced by formylmethionyl-leucyl-phenylalanine in human exudated cells

Exudate human polymorphonuclear neutrophils were isolated and investigated regarding oxidative responsiveness and priming ability. The exudate neutrophils were found to produce an increased amount of O2- and H2O2 when stimulated with formylmethionyl-leucyl-phenylalanine (fMLP), i.e. these cells were metabolically primed. Cytochalasin B (cyt B) pretreatment affected the production of O2- by exudate cells, although to a lesser extent than the production by peripheral blood cells, in which a substantial increase was induced. Addition of N-ethylmaleimide (NEM) to activated exudate and peripheral blood cells revealed no difference in oxidase inactivation rate. To induce further priming, the cells were incubated in vitro with a synthetic diacylglycerol (sn-1,2-didecanoylglycerol; diC10), or the Ca2+ ionophore ionomycin. Results of this procedure showed significant differences between exudate and peripheral blood neutrophils: the peripheral cells expressed a primed response, which was measured as increased fMLP-induced O2- production following incubation with both these substance; whereas the metabolic activity of exudated cells was not affected by diC10, but was significantly primed by ionomycin (P less than 0.01). The exact route for diacylglycerol priming is unknown. However, our results with human neutrophils primed during exudation indicate an exhausted diC10-priming pathway, with a retained sensitivity for priming [Ca2+]i rises.

Synovial fluid in arthropathy

The authors examined 487 synovial fluid specimens in patients affected with spontaneous effusion in the knee. In 202 of the cases the features indicating the nature of the effusion were observed (rheumatoid arthritis: 27; active S.L.E.: 2; microcrystals: 77; infections: 38; doubts as to rheumatoid arthritis or other connectivitis: 58). In 84 cases no features were determined despite the presence of specific clinical signs (psoriasis, arthrosis, previous trauma). In 201 cases where there were no clinical signs in the synovial fluid, the authors were able to differentiate moderate phlogosis in 27 specimens, and intense phlogosis in 104. Based on the results obtained, an attempt was made to define which tests are best to measure the amount of inflammation and which may be correlated with the etiology of the joint effusion.

Inhibition of growth of rat hepatoma by local injection of liposomes containing recombinant interleukin-2. Antitumor effect of IL-2 liposome

Human recombinant interleukin-2 (IL-2) was entrapped in liposome, consisting of egg phosphatidylcholine (PC) and cholesterol. The peri-tumor injections of IL-2 liposome inhibited significantly the growth of solid tumor and prolonged the survival time of rats with solid tumors which were induced by a subcutaneous (s.c.) inoculation of AH-66 cells. Immunohistochemical staining of peritoneal exudate cells and tumor tissues revealed a marked accumulation of activated macrophages in and around the tumor tissues induced by the local injections of IL-2 liposome.

Ultrastructural pathology of the 'barrier sites' in experimental autoimmune uveitis and experimental autoimmune pinealitis

Lewis rats were immunised with retinal S-antigen to induce experimental autoimmune uveitis and experimental autoimmune pinealitis. The blood-retinal and blood-pineal 'barrier sites' were examined by transmission electron microscopy. Inflammatory cell movement through Bruch's membrane involved separation of its constituent layers, cell migration through pores in the membrane, and between retinal pigment epithelial cells without causing significant displacement of the retinal pigment epithelial cell layer. The endothelial cells of retinal and pineal vessels with perivascular infiltrates showed morphological features resembling endothelium of 'high endothelial venules'.

Anti-inflammatory effect of gangliosides in the rat hindpaw edema test

The influence of total brain gangliosides on acute inflammation was investigated using the rat hind paw edema test. Total gangliosides (10 micrograms/paw) inhibited the edema produced by the injection of bee venom phospholipase A2 (5 micrograms/paw) when the lipids were co-injected or injected 15 min before the phospholipase A2. Sulphatide (10 micrograms/paw) did not inhibit the edema but potentiated it. Gangliosides (40 micrograms/paw) inhibited the edema induced by carrageenin 1% when they were injected 1 h before the agent. However, gangliosides (up to 200 micrograms/paw) failed to inhibit the dextran-induced edema. The edema test was also used to investigate the effect of gangliosides on the production of mediators of inflammation by peritoneal adherent macrophages. Gangliosides inhibited the production of mediators of inflammation only when they were incubated with these cells before the stimulation with phospholipase A2 or carrageenin. Gangliosides did not inhibit the production of mediators of inflammation when arachidonic acid was added to the cells. These results suggest that the anti-inflammatory effect observed with gangliosides is mediated by inhibition at or before endogenous phospholipase activity.

Effusion cytology

Cytologic evaluation is the best way to detect the presence of malignancy in body cavity fluids. Although a positive diagnosis is highly reliable, a negative result does not rule out a malignant cause. Adenocarcinomas, well-differentiated squamous carcinomas, small-cell carcinomas, malignant melanomas, large-cell lymphomas, and acute leukemias are accurately classified when present in effusions. The definitive diagnosis of malignant mesothelioma, small-cell lymphomas, and chronic leukemias, and subclassification of sarcomas and poorly differentiated neoplasms are difficult and may require additional diagnostic techniques. With a few exceptions, the exact causes of benign effusions cannot be determined by cytologic methods.

Immunocytochemical panel for the identification of malignant cells in serous effusions

The cytologic diagnosis of malignancy in serous effusions can be challenging. An immunocytochemical (ICC) panel using commercially available antibodies (to carcinoembryonic antigen [CEA], epithelial membrane antigen [EMA], B72.3, Leu-M1, cytokeratin [CK], leukocyte common antigen [LCA], S-100 protein, and vimentin) was applied to cell blocks fixed in methyl Carnoy's solution that were from 55 consecutive pleural, peritoneal, and pericardial fluid specimens. The results were correlated with data from clinical records and routine cytologic studies. Final cytologic diagnoses included 26 of adenocarcinoma and 1 of mesothelioma. The remaining 28 cases were considered to be benign (reactive) proliferations. EMA, CEA, B72.3, and Leu-M1 were present in 96%, 77%, 58%, and 42% of adenocarcinomas, respectively. These determinants were absent in the mesothelioma and the reactive effusions, although anti-CEA yielded strong background staining of inflammatory cells. The CK markers identified malignant cells in 93% of cases, but consistently stained mesothelial cells as well. Antivimentin strongly labeled mesothelial cells in all cases, with weak to absent staining of malignant cells. In 3 of 26 carcinoma cases (12%), the ICC panel identified malignant cells that were not recognized initially on routine cytologic examination. In 1 of 26 cases (4%), the panel was falsely negative. Use of this approach can improve the diagnostic accuracy of cytologic examination of serous fluids. The ICC panel is especially helpful when atypical mesothelial proliferation is present, or in cases that are clinically suspect for malignancy, but cytologically negative because there are only a few malignant cells, or those that are cytologically bland.

Prominent mononuclear cell infiltrate is characteristic of herpes esophagitis

Diagnosis of herpes esophagitis is often difficult since the characteristic nuclear inclusions and/or multinucleate giant cells of herpes virus infection may be absent in endoscopic biopsy specimens. We have noted aggregates of large mononuclear cells with convoluted nuclei adjacent to infected epithelium in the exudates of herpetic esophagitis, and postulate that this is a characteristic inflammatory response to the virus. To test this hypothesis, we reviewed biopsies from 22 cases of ulcerative herpetic esophagitis and from 44 control cases of nonherpetic esophageal ulcers (including nine cases of candidal and five cases of bacterial esophagitis) that contained a quantifiable amount of exudate. The estimated percentage of mononuclear cells present in the specimens was ranked independently by two reviewers using coded photomicrographs of exudate. Wilcoxon's rank sum analysis demonstrated significant correlation between presence of herpes and increased mononuclear cells (P less than .0001). Only one of the 22 herpes cases did not show a prominent mononuclear cell infiltrate. Immunoperoxidase studies performed on Hollande-Bouin's-fixed paraffin-embedded material from 11 herpes cases showed strong staining of the mononuclear cells for KP-1 (CD68), indicating that the majority of these cells are macrophages. These findings suggest strongly that aggregates of macrophages are characteristic of the inflammatory response in ulcerative herpetic esophagitis. The presence of these mononuclear cells in a biopsy specimen that initially does not show herpetic inclusions warrants additional studies to rule out herpes virus infection.

Class II histocompatibility antigen expression by cellular components of vitreous and subretinal fluid in proliferative vitreoretinopathy

Proliferative vitreoretinopathy (PVR) is the major cause of failure in retinal detachment surgery. It is characterized by the formation of membranes extending along both surfaces of the detached retina and within the vitreous, but the nature of the growing cells has not yet been determined. Using cytologic and immunocytologic procedures with 13 different monoclonal antibodies directed against Class II histocompatibility antigens and various markers of epithelial and immunocompetent cells, 30 specimens were studied of vitreous or subretinal fluid removed from patients with PVR. Five main types of cells could be identified: heavily pigmented cells, poorly pigmented ones, large totally unpigmented macrophage-resembling ones, smaller unpigmented cells, and lymphocytes. Analysis of intravitreal pigment granules, using autofluorescence by epiillumination and cytologic procedures, showed two different populations of pigmented cells: one with autofluorescent lipofuscin granules and the other with exclusively melanin pigment. Immunostaining procedures confirmed the epithelial nonmacrophage lineage of the intravitreal and subretinal cells because most of these cells were positive for cytokeratin but negative for macrophage markers. In addition, 40-100% of these epithelial-derived cells strongly expressed Class II histocompatibility antigens HLA-DR and -DQ. Lymphocytes were found in 13 specimens; B-cells were seen, but no T-lymphocytes could be identified. These results confirm the involvement of retinal pigment epithelial cells and the strong morphologic changes they undergo during the course of PVR. Moreover, the expression of Class II histocompatibility antigens by the growing cells may be related to inflammatory phenomena, but their eventual role in the development and the extension of periretinal proliferation has not been determined.

Diagnostic efficacy of pleural biopsy as compared with that of pleural fluid examination

Previous studies compared the diagnostic value of pleural fluid cytology versus pleural biopsy. No direct comparison of the procedures including data from a combination of all diagnostic tests performed on each specimen appears to have been done. A total of 385 patients with concurrent pleural biopsy and fluid examination were identified from 1973 to 1986. Clinical records, histologic and cytologic preparations, and microbiologic and chemical data were reviewed. A total of 109 patients had a final diagnosis of malignancy. Cytology was diagnostic in 71% and "suggestive" in an additional 8%. There were no false-positives but, in two patients with pulmonary infarcts, the effusions were reported as "suspicious." Pleural biopsy was positive in 45%, including three cases with negative cytology. In 71 patients with tuberculosis, the pleural biopsy was diagnostic in 49%. A cytologic picture suggesting the diagnosis was present in 68%. Cultures of the biopsy yielded Mycobacterium tuberculosis in 23% of cases, while pleural fluid was positive in 30%. In six cases, the only confirmatory evidence of tuberculosis was pleural culture. In 205 patients, none of the above procedures provided specific diagnoses. A combination of biopsy and fluid examinations improves the diagnostic sensitivity. Pleural biopsy increases the rate of complications and did lead to fatal hemothorax in two patients. These results support the superiority of pleural fluid examination in the diagnosis of malignancy. In addition, they demonstrate the value of pleural fluid examination in the diagnosis of tuberculosis.

Correlation of histopathological features of pannus with patterns of damage in different joints in rheumatoid arthritis

The cartilage-pannus junction has been studied in multiple sections from 23 rheumatoid joints. Changes suggesting a metaplastic reaction of the articular cartilage, termed transitional fibroblastic zone, were commonly found in hips and knees, but were rarely present in metatarsophalangeal joints, in which an invasive pannus with cartilage degradation in close association with inflammatory cells was seen. Thus when multiple sections from rheumatoid joints were examined a transitional fibroblastic zone was found in 1/15 (7%) sections from metatarsophalangeal joints compared with 29/57 (51%) and 15/48 (31%) sections from knee and hip joints respectively. In contrast, an invasive pannus occurred in 11/15 (73%) sections from metatarsophalangeal joints compared with 22/57 (39%) sections from knees and 19/48 (40%) sections from hips. These findings led to the suggestion that this pathological variation between different joints may explain the predominance of erosive change in small joints as compared with joint space narrowing with secondary osteoarthritis found in large joints in rheumatoid arthritis. Inappropriate comparisons between different joints may in part explain the variation in findings of previous histopathological studies.

Evaluation of immunocytochemical staining as a method of improving diagnostic accuracy in a routine cytopathology laboratory

Immunocytochemical stains in a routine cytopathology laboratory can be used to distinguish between benign and malignant cells, and to identify tumour type. In our laboratory 30 problematic cases were selected for immunocytochemical stains and the results analysed in this paper. The following markers were used: cytokeratin (CAM5.2), carcinoembryonic antigen (CEA), kappa and lambda light chains, leucocytic common antigen (LCA), chorionic gonadotrophin (hCG), prostate specific antigen (PSA), L26, UCHL1, S100-protein and vimentin. Twelve FNA (four lymph nodes, one parotid swelling, two from lungs, two from pleura and chest wall, one from lumbar region, two from soft tissue masses), and 18 effusions (12 pleural effusions, five ascitic fluids, one pericardial effusion) were investigated. We found immunocytochemical stains of value in formulating the cytological diagnosis in 11/12 of FNA and 15/18 of effusions.

The subretinal fluid in retinal detachment. A cytologic study

Following retinal detachment, subretinal fluid (SRF) fills the neoformed space. Subsequently subretinal and preretinal strands of proliferative tissue begin to form. We have collected the subretinal fluid withdrawn during retinal detachment surgery. We have studied subretinal fluid cytologically to evaluate the number and the type of cells present in the fluid, and by means of transmission electron microscopy. The first cell type to be present in the fluid represented degenerated aspects of pigmented epithelial cells (PECs). Successively, other cell types appeared in the fluid as nerve cells (rods, cones and glial cells), macrophages and well preserved pigmented epithelial cells.

Immunophenotyping of mesothelial cells and carcinoma cells with monoclonal antibodies to cytokeratins, vimentin, CEA and EMA improves the cytodiagnosis of serous effusions

This paper presents an immunocytochemical study performed on cytocentrifuged deposits from 109 peritoneal and pleural effusions including 20 transudates, 43 malignant metastatic effusions and 46 effusions containing atypical cells, unidentifiable as reactive mesothelial or malignant epithelial cells on the classical morphological criteria. A panel of four monoclonal antibodies (MAb) was used, including KL1 directed to cytokeratins (KER), V9 to vimentin (VIM), NEO 723 to carcinoembryonic antigen (CEA) and E29 to epithelial membrane antigen (EMA). In most transudates the reactive mesothelial cells coexpressed VIM and KER with a ring-like pattern for the latter proteins. In contrast, they were unreactive to anti-CEA and weakly and inconsistently reactive to anti-EMA. In malignant effusions, most carcinoma cells coexpressed EMA, CEA and KER with a predominant diffuse cytoplasmic pattern for the latter. Only a few malignant epithelial cells from five metastatic adenocarcinomas weakly expressed VIM. When used on the 46 effusions with unidentifiable cells, the panel of MAb allowed reactive mesothelial cells and malignant epithelial cells to be distinguished from each other in 39 of 46 cases (85%).

[The comparative study of fluids in middle ear cavity and maxillary sinus--biochemical and cytological analysis]

Both paranasal and middle ear cavities are surrounded by bony walls and are lined with upper respiratory mucosae. Thus it can be worthwhile to compare the biochemical and cytological characteristics of the fluids in these cavities, and this gives valuable information to help us to understand the pathogenesis of otitis media with effusion. The fluids in the otitis media with serous effusion (OME-S), otitis media with mucoid effusion (OME-M) and acute otitis media (OMA) were sampled for the middle ear diseases, and those in postoperative maxillary cyst (POMC) and acutely aggravated chronic maxillary sinusitis (CMS) were chosen for maxillary sinus group. LDH (lactate dehydrogenase). ALP (alkaline phosphatase), CHO (total cholesterol), LDH isozymes and ALP isozymes of these effusions were assayed and the results of each group were compared. Coincidently, through smear samples of these effusions, infiltrating cell count, cell differential count and cholesterol crystals were observed microscopically. LDH activity of the fluids was extremely higher than those of the serum in all diseases. The LDH activity ratios to serum were CMS greater than or equal to OMA greater than or equal to OME-M greater than POMC greater than OME-S in order of activity. LDH isozyme analysis showed higher LDH 4 and 5 than LDH 1 and 2 in all diseases. ALP activity ratios to serum were OME-S greater than or equal to OMA greater than OME-M much greater than POMC greater than or equal to CMS in order of activity. Middle ear diseases manifested higher ALP activities than maxillary diseases. CHO ratios to serum were POMS greater than OME-M greater than or equal to OME-S greater than CMS greater than or equal to OMA in order of quantity. This result agreed with the frequencies of cholesterol crystallization of these fluids. The fluids of OME-M showed mild infiltration of cells, and cell differentiations were polymorphonuclear leucocyte greater than lymphocyte much greater than macrophage much greater than epithelial cell in order of cell numbers. There were few infiltrating cells in the fluids of OME-S and differentiations were lymphocyte greater than or equal to polymorphonuclear greater than or equal to macrophage in order of numbers. There were a few cells but were many cell debris in the fluids of POMC, and cells were polymorphonuclear much greater than macrophage greater than lymphocyte in order of cell count.

Diversity amongst the microglia in growing and regenerating fish CNS: immunohistochemical characterization using FL.1, an anti-macrophage monoclonal antibody

We have immunohistochemically characterized the forms and distribution of microglia--the macrophages of the CNS--in fish, using a new monoclonal antibody (mAb), FL.1. This mAb specifically reacts with resident macrophages throughout the body in Oreochromine fish, including Kuppfer cells, gut-associated myeloid cells, and peritoneal macrophages, as well as with microglia, but circulating monocytes are not labelled with FL.1. The FL.1-epitope, which is lost following treatment with reducing agents, has an extracellular location and is associated with three integral membrane glycoprotein variants. FL.1-staining shows that microglia are extremely abundant throughout the fish CNS. For example, they comprise a third of the glia in the optic nerve, and 30% of all cells, including neurons, in the spinal cord, i.e., fish have about tenfold more microglia than mammals. Two forms of FL.1-positive microglia are predominant in fish, one resembling their mammalian counterparts, but less ramified, and the other comprising smaller rounded cells with very little cytoplasm, which are most numerous in the ependymal region of the optic tectum. Apart from the conventional microglia, the optic nerves also contain large lipid-laden macrophages which comprise a third form of FL.1-positive cell in the CNS. Fish optic nerves contain astrocytes of a distinct type which form reticular networks, but lack connections to capillaries (Maggs and Scholes, J. Neurosci. 1990;10:1600-1614). The co-distribution of foamy macrophages may have a metabolic role that is performed by ordinary astrocytes elsewhere in the CNS. An antiserum against the beta 2 subunit of the human leukocyte integrins (Kishimoto et al., Cell 1987a; 50:193-202) was found selectively to recognize the foamy macrophages in Oreochromis. Following lesion to the optic nerve, FL.1-labelling shows that microglia proliferate throughout the visual pathway. In the optic tectum, the additional FL.1-positive cells are concentrated in the vicinity of degenerating retinal axons and their terminals. Most of the microglia in the injured optic nerve have amoeboid morphologies, and the foamy macrophages become depleted.