ICAM-1 expression on alveolar macrophages and in serum of sarcoidosis patients

The intercellular adhesion molecule-1 (ICAM-1) is important in mediating intercellular contact in inflammation. Therefore, we have analyzed the expression of this molecule on alveolar macrophages (AM) and in serum of patients with sarcoidosis. Bronchoalveolar lavage (BAL) cells from 13 patients and 11 control donors were stained with an anti ICAM-1 monoclonal antibody (mAb) or an isotype control. Alkaline phosphatase was used as a detection system, followed by digital single cell image analysis. Soluble ICAM-1 in serum (ssICAM-1) was determined by enzyme linked immunoassay (Elisa). Immunocytochemistry revealed a strong increase of ICAM-1 expression on AM from sarcoidosis patients (64%) compared to healthy controls (30%). Furthermore, patients exhibited a fourfold higher antigen density. Serum levels of sICAM-1 were more than twofold increased in the patient group (805.4 micrograms/ml) compared to healthy controls (384.8 micrograms/ml). SsICAM-1 showed an inverse correlation with vital capacity (VC) and diffusing capacity (DCO). This significant correlation with impairment of two important lung function parameters suggests that ssICAM-1 might be useful in serological assessment of disease activity in sarcoidosis.

A placebo-controlled evaluation of single, escalating doses of CL 284,846, a non-benzodiazepine hypnotic

This report describes the first evaluation in humans of CL 284,846, a non-benzodiazepine compound with a preclinical profile indicative of sedative/hypnotic properties. Healthy, normal male volunteers were assigned randomly to receive single oral doses of 1, 5, 15, 30, or 60 mg of CL 284,846 or placebo on a double-blind basis. Observations were made over the subsequent 25 hours to determine the safety, pharmacokinetic profile, and psychometric effects of the test compound. CL 284,846 was well tolerated in the normal volunteers, causing no significant changes in vital signs, EEG, ECG, hematologic, or clinical chemistry laboratory parameters. Although few adverse events were noted at doses less than 60 mg, at the highest dose (60 mg), all volunteers reported transient neurologically related adverse events (e.g., impaired concentration, difficulty focusing, and impaired coordination), reflecting the central nervous system action of the compound. Although determination of hypnotic efficacy was not an objective in this Phase I study, daytime treatment with 60 mg of CL 284,846 was associated with greater reports of drowsiness and impaired performance on psychomotor tests. However, memory, as assessed by a word recall test, was not affected at any dose of the compound. Pharmacokinetic analyses revealed CL 284,846 to be absorbed and eliminated rapidly (Tmax = 0.9-1.5 hr, T 1/2 = 0.9-1.1 hr), with a dose-proportional AUC (area under cure). Plasma levels of CL 284,859, the primary desethylated metabolite of CL 284,846, were much lower in humans than in other species, indicating that the metabolism of CL 284,846 in humans may differ from that of rodents and dogs. Overall, CL 284,846 was well tolerated, and the authors recommend repeating dose safety and pharmacokinetic studies in healthy volunteers.

Expression of CD14 correlates with lung function impairment in pulmonary sarcoidosis

CD14 expression on alveolar macrophages (AM) was studied in patients with sarcoidosis using immunocytochemistry and cytometric analysis. Compared with healthy control donors, patients had elevated percentages of CD14-positive AM (22 percent vs 34 percent), and the antigen density was threefold higher (92 vs 297 channels). Furthermore, soluble serum CD14 (ssCD14) was significantly elevated in patients with sarcoidosis with an average of 5.3 +/- 1.6 mg/L vs 3.2 +/- 0.7 mg/L in healthy control subjects. Follow-up of one patient, whose lung function test results improved during therapy with corticosteroids, revealed a concomitant decrease of CD14 staining on AM and of ssCD14. Statistical analysis revealed a negative correlation between CD14 expression on AM and PO2 at rest (p = 0.0005), and after labor (p = 0.02). Levels of ssCD14 gave a positive correlation to reduction of Dco (p = 0.006) and VC (p = 0.05). These data suggest that CD14 expression is related to severity of disease and that it may be useful for monitoring in sarcoidosis.

Increased expression of the monocyte differentiation antigen CD14 in extrinsic allergic alveolitis

Expression of the CD14 antigen was studied on alveolar macrophages in extrinsic allergic alveolitis (EAA), using immunocytochemistry and cytometry. Compared to control donors, EAA patients had higher percentages of My4 positive cells (40 versus 22%), and the antigen density was fourfold higher (410 versus 92 channels). Levels of soluble CD14 (sCD14) in serum were found to be increased in EAA patients with an average of 4.6 +/- 1.5 micrograms.ml-1 compared to 3.2 +/- 0.7 micrograms.ml-1 in controls. Follow-up of patients with antigen avoidance revealed a concomitant decrease of CD14 staining of alveolar macrophages (AMs) and of sCD14 in serum, whilst allergen exposure induces both parameters. These data are consistent with the concept that antigen contact upregulates CD14 expression on AMs in EAA, followed by shedding and increase of sCD14 in serum.

[Detection of the IgE receptor CD23 in sarcoidosis]

In 30 sarcoidosis patients the soluble IgE receptor sCD23 was determined. Compared to healthy controls a marked increase of this molecule could be detected in serum (4.9 versus 0.9 ng/ml). In 19 patients who underwent bronchoscopy a strong expression of CD23 on alveolar macrophages could be demonstrated in immunochemistry compared to healthy controls (40.8 versus 12.6%). Determination of total IgE and anti-IgE antibodies did not allow discrimination between healthy controls and sarcoidosis patients. Our data suggest that alveolar macrophages are an important source for soluble CD23 in serum. CD23 expression might reflect functional activation of macrophages since our results do not appreciate a role for IgE-related reactions in sarcoidosis.

Proliferating alveolar macrophages in BAL and lung function changes in interstitial lung disease

In interstitial lung disease, the number of alveolar macrophages (AMs) can be increased. This may be caused by recruitment of precursor cells from peripheral blood and/or local proliferation in the lung. We therefore analysed proliferation, by studying both the expression of the nuclear proliferation antigen, Ki67, and the deoxyribonucleic acid (DNA) content, using the Feulgen reaction followed by cytometry. The patients had interstitial lung disease, i.e. sarcoidosis (n = 20), extrinsic allergic alveolitis (n = 20), idiopathic lung fibrosis or lung involvement in collagen-vascular disease (n = 19). In all patient groups there was a significant increase in proliferating AMs compared to healthy controls (4.2 versus 1.4% Feulgen, 2.1 versus 0.5% Ki67), with a significant correlation between these two parameters. A positive correlation was also found in bronchoalveolar lavage (BAL) between numbers of lymphocytes and proliferating cells in sarcoidosis and in fibrosis. In fibrosis, numbers of eosinophils and proliferating cells were also positively correlated. Our main finding was, however, a positive correlation between numbers of proliferating cells (Feulgen) and lung function parameters, especially vital capacity and oxygen tension (PO2) at rest, in patients with sarcoidosis and lung fibrosis. By contrast, in extrinsic allergic alveolitis, no correlation could be observed between proliferating cells and cell population or lung function. Our results suggest that local proliferation of macrophages is an important element in interstitial lung disease.

Proliferating alveolar macrophages in BAL and lung function changes in interstitial lung disease

In interstitial lung disease, the number of alveolar macrophages (AMs) can be increased. This may be caused by recruitment of precursor cells from peripheral blood and/or local proliferation in the lung. We therefore analysed proliferation, by studying both the expression of the nuclear proliferation antigen, Ki67, and the deoxyribonucleic acid (DNA) content, using the Feulgen reaction followed by cytometry. The patients had interstitial lung disease, i.e. sarcoidosis (n = 20), extrinsic allergic alveolitis (n = 20), idiopathic lung fibrosis or lung involvement in collagen-vascular disease (n = 19). In all patient groups there was a significant increase in proliferating AMs compared to healthy controls (4.2 versus 1.4% Feulgen, 2.1 versus 0.5% Ki67), with a significant correlation between these two parameters. A positive correlation was also found in bronchoalveolar lavage (BAL) between numbers of lymphocytes and proliferating cells in sarcoidosis and in fibrosis. In fibrosis, numbers of eosinophils and proliferating cells were also positively correlated. Our main finding was, however, a positive correlation between numbers of proliferating cells (Feulgen) and lung function parameters, especially vital capacity and oxygen tension (PO2) at rest, in patients with sarcoidosis and lung fibrosis. By contrast, in extrinsic allergic alveolitis, no correlation could be observed between proliferating cells and cell population or lung function. Our results suggest that local proliferation of macrophages is an important element in interstitial lung disease.

Use of two virustatica (AZT, PMEA) in the treatment of FIV and of FeLV seropositive cats with clinical symptoms

In the present study the therapeutic efficacy and the side effects of two antiretroviral compounds used in human acquired immunodeficiency syndrome (AIDS) research, 3'-azido-2',3'-dideoxythymidine (AZT, zidovudine, Retrovir) and 9-(2-phosphonylmethoxyethyl)adenine (PMEA), were investigated in the treatment of cats naturally infected with feline immunodeficiency virus (FIV) and cats naturally infected with feline leukemia virus (FeLV). AZT was administered subcutaneously at a dose of 5 mg kg-1 body weight every 12 h and PMEA was administered subcutaneously at a dose of 2.5 mg kg-1 body weight every 12 h during a 3 week hospitalization. The therapeutic efficacy of both compounds was investigated. There was a stronger potency of PMEA than of AZT on the regression of stomatitis in FIV and in FeLV infected cats. In addition, in FIV infection PMEA had a stronger effect on the improvement of the general clinical status. Both antiretroviral compounds were potent agents to improve the immunologic status of FIV infected cats by raising the CD4/CD8 ratio. In FeLV infection PMEA and AZT appeared to reduce antigenemia. The hematological side effects caused by PMEA were severe and stronger than those of AZT. Therefore the advantage of PMEA in clinical and immunologic improvement was diminished by the hematologic disorders, which do not allow long term treatment with this drug in the dose used.

Expression of the adhesion molecule ICAM-1 on alveolar macrophages and in serum in extrinsic allergic alveolitis

ICAM-1 expression was studied on alveolar macrophages (AM) in extrinsic allergic alveolitis (EAA) using immunocytochemistry and cytometry. Compared to control donors, EAA patients had higher percentages of ICAM-1+ AM (75% vs. 30%) and the antigen density was more than sixfold higher (673 vs. 103 channels). Levels of soluble serum ICAM-1 were found increased in EAA patients with an average of 866.2 +/- 300 ng/ml versus 394.8 +/- 110 ng/ml in controls. These data are consistent with the concept that antigen contact upregulates ICAM-1 expression on AM in EAA followed by shedding and an increase in serum sICAM-1.

[Trichomonad infections of the oral cavity in cats in south Germany]

In this investigation trichomonads were isolated from the oral cavity in 21 of 110 examined cats, and only from those which were simultaneously FeLV, FIV or FIP positive. By means of scanning electron microscopy the trichomonads were shown to be round or piriform parasites which were on average 7.9 microns long and 6.2 microns wide at maximum width. They had 4 anterior flagella, which were on average 9.4 microns long, an undulating membrane measuring 6.7 microns with no trailing flagellum as well as an axostyle extending on average 5.0 microns beyond the body, and therefore should be attributed to the genus Trichomonas.

Interleukin-1 beta decreases acetylcholine measured by microdialysis in the hippocampus of freely moving rats

Interleukin (IL-1) is a cytokine which plays an important role in the modulation of the acute response in host defense. This cytokine is also increased in patients with Alzheimer's disease. In the present experiment systemic injection of IL-1 beta (7.5-50 micrograms/kg) decreased extracellular acetylcholine in the hippocampus. This effect could not be attributed entirely to general malaise since lithium chloride (130 mg/kg) had the opposite effect. Heat-inactivation of the cytokine eliminated the reduction of extracellular ACh. The results give further evidence of a relationship between the immune system and the central nervous system and suggest a possible relationship between IL-1 and cholinergic function or dysfunction in the hippocampus.

Screening for potassium channel modulators by a high through-put 86-rubidium efflux assay in a 96-well microtiter plate

A rapid and sensitive 86Rb efflux assay to detect chemical compounds capable of modulating the ATP-dependent potassium (KATP) channel is described. This assay, which is performed in a 96-well microtiter plate, utilizes a substrate adherent cell line as the target, requires a small amount of 86Rb as the tracer, and is a suitable system for performing the biochemical and pharmacological characterization of the KATP-channel and its activators. Because this assay is amenable to automation, it presents a useful means for high-volume screening of chemical compounds on a routine basis.

Gene expression in Xenopus oocytes

1. Gene expression in Xenopus oocytes is now an integral part of many molecular cloning strategies. 2. For some genes, such as those encoding the ion channels, this system has emerged as the only available means to authenticate and examine the biological activities of the cloned DNA. 3. This review discusses some of the current applications of Xenopus oocytes in modern molecular biology.

Interleukin-1 stimulates the beta-amyloid precursor protein promoter

1. Amyloid plaques found in the brains of Alzheimer's diseased patients are composed of the 42 amino acid beta-amyloid peptide (BAP) which is processed out of the larger amyloid precursor protein (APP). 2. To study the regulation of the APP gene expression, we have isolated the promoter region of this angle of this single-copy gene and produced a reporter gene system to determine if the promoter is responsive to agents that may cause the overproduction of APP leading to the abnormal accumulation of plaques in AD. 3. The promoter contains sequences homologous to heat shock elements, AP-1 binding sites, and phorbol ester-inducible sequences as well as GG-rich regions found in other constitutively expressed genes. 4. We show here that this promoter is inducible in cultured cells by interleukin-1 (IL-1) in a transient assay system and that the HSE and AP-1 binding site are required for this inducibility. 5. This induction of transcription from the APP promoter implies that this gene is responsive to tropic and/or trophic agents which may be present in the diseased brain.

Mast cell degranulating peptide: a multi-functional neurotoxin

This review discusses our present knowledge of the structure and activities of the mast cell degranulating peptide (MCDP). This peptide is a basic, 22 amino acid residue component of honey bee venom with striking immunological and pharmacological activities. MCDP is a potent anti-inflammatory agent, but at low concentrations it is a strong mediator of mast cell degranulation and histamine release. MCDP is also an epileptogenic neurotoxin, an avid blocker of the potassium channels and can cause a significant lowering of the blood pressure in rats. Some of the biological activities of MCDP appear to have distinct mechanisms and may represent a good illustration of the structure-function relationship.

Differential expression of gamma-aminobutyric acidA receptor subunits

A 1.8-kilobase (kb) cDNA clone for a beta 1 subunit of the human gamma-aminobutyric acidA (GABAA) receptor has been isolated and sequenced. The longest open reading frame of the clone, pCLL610, contains nucleotide sequence encoding a portion of the putative signal sequence followed by 449 amino acids of the entire mature protein. The deduced amino acid sequence of pCLL610 differs from a recently described human beta 1 subunit by a single amino acid. The amino acid sequences of the human GABAA receptor beta 1 subunits share 98% identity with the beta 1 subunits of the bovine and rat GABAA receptor, with the majority of the differences occurring in the intracellular loop between the M3 and M4 transmembrane regions of the protein. A single 11-kb transcript is observed in Northern blots of poly(A)+ RNA isolated from rat brain probed with nick-translated pCLL610. In human brain, the pCLL610 probe recognized the 11-kb message, in addition to two other bands between 8 and 11-kb. Developmental studies of rat brain mRNA show that the message of the GABAA beta 1 subunit is highest at birth, rapidly decreases, and reaches adult levels of 5 to 7 days of age. This is in contrast to the development of the alpha 1 subunit, which is low from days 1 to 5 and increases to adult levels by days 14 to 25. Relative levels of the mRNA for the alpha 1 and beta 1 subunits vary among rat brain regions. The levels of mRNA for the alpha 1 subunit are similar in the cortex, hippocampus, and midbrain, whereas cerebellar levels are twice those in the cortex. The rank order of the relative amount of beta 1 subunit message is hippocampus greater than cortex = midbrain greater than cerebellum. These data, taken with our previous study of the alpha 1 subunits of the GABAA receptor, suggest that the differences in the distribution and regulation of the alpha 1 and beta 1 subunits may reflect a variety of subunit combinations forming the GABAA receptor. Heterogeneity in the GABAA receptor composition may provide a molecular basis for the diverse pharmacological properties associated with this receptor.

Mitochondrial benzodiazepine receptors mediate inhibition of mitochondrial respiratory control

Drugs that bound to the peripheral-type or mitochondrial benzodiazepine receptors in rat kidney mitochondria produced several effects on mitochondrial respiration with succinate and malate/pyruvate as substrates. These drugs increased state IV and decreased state III respiration rates, which resulted in a significant decrease in the respiratory control ratio. ADP: O ratios were not affected. The receptor binding affinities of a set of 10 compounds (Ro5-4864, PK11195, diazepam, mesoporphyrin IX, flunitrazepam, deuteroporphyrin IX, dipyridamole, dibutylphthalate, cyclosporin A, and CL259,763) correlated over a concentration range of almost 4 orders of magnitude with their potencies at inhibiting respiratory control (r = 0.95). The anxiolytic benzodiazepine clonazepam had no effect on mitochondrial respiratory control and bound with negligible affinity to the receptor. The magnitude of the effect of Ro5-4865 on respiration increased in parallel with the density of mitochondrial benzodiazepine receptors in mitochondria from liver, kidney, and adrenal. These results suggest that ligand binding to mitochondrial benzodiazepine receptors results in inhibition of mitochondrial respiratory control. This effect may help to explain the pleiotropic effects of receptor ligands on intact cells.

Absence of mutation in the beta-amyloid cDNAs cloned from the brains of three patients with sporadic Alzheimer's disease

Using an oligonucleotide probe, we isolated cDNA clones corresponding to the precursor of the beta-amyloid peptide (BAP) from brain libraries of 3 patients with sporadic Alzheimer's disease (AD). DNA sequencing showed that the largest cDNA clone encompasses 83% of the open reading frame proposed by Kang et al. to encode the BAP precursor (APP). cDNA clones from each of the 3 AD brain libraries were identical to the sequence of the APP-cDNAs cloned from normal adult human and fetal brain. An antisense-radiolabeled RNA copy of one of the AD clones detected a pattern of 3 gene transcripts measuring 3.5, 3.2 and 1.6 kilobases (kb) in both normal and AD brain RNAs. These data suggest that there are no mutations in or about the 42 amino acid (aa) sequence of BAP and that the accumulation of amyloid consistently found in AD may result from altered post-translational processing of APP.

Heterogeneity of benzodiazepine binding sites: a review of recent research

This paper reviews selected aspects of benzodiazepine binding site heterogeneity. These include receptor heterogeneity revealed by biochemical determinations of receptor numbers, autoradiographic localization in histological sections of brain, lesion studies, solubilization of receptors, and photoaffinity labelling. The data summarized support the concept of benzodiazepine receptor multiplicity. In addition, we have reviewed recent work on peripheral-type benzodiazepine binding sites and suggest that further study of these sites may increase our understanding of both the central and peripheral actions of benzodiazepines and other ligands.

Interaction of amoxapine with muscarinic cholinergic receptors: an in vitro assessment

Amoxapine, an antidepressant with a rapid onset of therapeutic efficacy and great utility in psychotic depression, has been reported to produce anticholinergic side effects in man similar to those observed with imipramine and amitriptyline. To establish its cholinergic disposition, amoxapine and its metabolites 7-hydroxyamoxapine and 8-hydroxyamoxapine, have been evaluated by determining their effects on quinuclidinyl benzilate (QNB) binding to membrane fractions of rat and human brain, on the carbamoylcholine-stimulated accumulation of inositol phosphates in rat cerebral cortex and on the acetylcholine-induced contraction of the guinea pig ileum. In all three preparations, amoxapine was found to be a considerably weaker antagonist of muscarinic cholinergic receptors than either imipramine (4-27 fold) or amitriptyline (51-300 fold). These results indicate that for amoxapine, no correlation exists between the magnitude of muscarinic receptor inhibition and the extent of 'anticholinergic' side effects found in the clinic. Neither the metabolites of amoxapine nor species differences could account for this discrepancy.

Heterogeneity of brain benzodiazepine receptors: effects of physiological conditions

A number of investigators have shown compelling evidence for multiplicity of benzodiazepine (BDZ) receptors. The present study addresses the query of BDZ receptor heterogeneity, in vitro, with respect to temperature. In competition studies involving rat cerebellar tissue, CL 218,872 produced Hill slopes near unity at both 0 degree C and 37 degrees C. In contrast, similar experiments utilizing cortical tissue from rats and mice produced Hill slopes of 0.69 and 0.66 at 0 degree C and 37 degrees C respectively. 3H-Flunitrazepam-photoaffinity labeling of cortical and cerebellar membranes was conducted at 0 degree C and 37 degrees C. SDS-PAGE fluorographic analyses of photolysed 3H-flunitrazepam (3H-Flu) revealed one intensely labeled 51K band in the cerebellum at both temperatures, which was specifically chased by diazepam. Similar experiments conducted in cortical tissue revealed photoaffinity labeling of at least three distinct macromolecules, one intense 51K and two less intense 55K and 59K bands. Labeling of each of these bands was chased specifically by diazepam. These data, taken together, indicate the existence of regional BDZ receptor heterogeneity under physiological conditions.

Psychomotor performance in the senescent rodent: reduction of deficits via striatal dopamine receptor up-regulation

In order to determine the relationship between striatal dopamine (DA) receptor density and psychomotor performance in senescent animals, two experiments were carried out. In the first, the age-related motor deficits were characterized using a battery of four psychomotor tests (rod walking, wire hanging, inclined screen, plank walking). These tests were administered to three groups of male Fischer rats (mature, 6-8 months; middle aged, 12-18 months; and senescent, 25 months) and performance measured. Age-related differences were observed on all the tasks, with the oldest animals showing the poorest performance. These animals were then used in a second experiment in which one-half of the group of animals from each age was administered 1.86 mg/kg/day of haloperidol for 14 days (via surgically implanted Alza Minipumps. Control groups of animals from each age were given pumps which contained only the vehicle (HCl diluted with distilled water, pH = 2.9). Following the 14 day drug administration, the pumps were surgically removed and 3 days later all the groups were retested on the psychomotor tests. Stereotypy (to 0.5 mg/kg of apomorphine, sniffing, licking, grooming and cage crossings) was also re-examined. Results show that haloperidol-treated animals from all three age groups display greater response times (i.e., better performance) than vehicle-treated animals on the battery of four motor tests and, the haloperidol-treated old animals exhibit more sniffing and grooming than the vehicle-treated old animals. Parallel increases in [3H]spiperone binding seen in all haloperidol-treated groups suggest a relationship between increases in the density of striatal DA receptors and improvement in motor performance.