Outcome of maintenance systemic chemotherapy with drug-free interval for metastatic urothelial carcinoma

OBJECTIVE

Aiming to achieve long-term disease control, maintenance systemic chemotherapy (MSC) with a 1-3-month drug-free interval is continued in selected patients. We report our experience of MSC for metastatic urothelial carcinoma (UC).

METHODS

Of 228 metastatic UC patients treated with systemic chemotherapy, 40 (17.5%, 40/228) had continuously undergone MSC. Data on the regimen, cycle number, and reason for the discontinuation of MSC were also collected. We analyzed OS from the initiation of MSC until death or the last follow-up, using the log-rank test to assess the significance of differences.

RESULTS

The median number of cycles of chemotherapy was 6, and the responses were CR in 6, PR in 20, SD in 13, and PD in 1 before MSC. Gemcitabine plus CDDP or carboplatin was mainly performed as MSC (70%, 28/40). MSC was repeated quarterly in 30 (75%, 30/40), every two months in 8 (20%, 8/40), and with other intervals in 2 (5%, 2/40). Overall, a median of 3.5 cycles (range: 1-29) of MSC was performed. The reason for the discontinuation of MSC was PD in 24 (60%, 24/40), favorable disease control in 9 (22.5%, 9/40), and myelosuppression in 3 (7.5%, 3/40), and for other reasons in 2 (5%, 2/40). MSC was ongoing in 2 (5%, 2/40). The median OS was 27 months from the initiation of MSC. PS0 (P = 0.0169), the absence of lung metastasis (P = 0.0387), and resection of the primary site (P = 0.0495) were associated with long-term survival after MSC.

CONCLUSIONS

In selected patients, long-term systemic chemotherapy could be performed with a drug-free interval. Our maintenance strategy with cytotoxic drugs may become one of the treatment options for long-term disease control.

Parasitoid secretions provoke ant warfare

Insect social parasites are extreme specialists that typically use mimicry or stealth to enter ant colonies to exploit the rich, but fiercely protected, resources within their nests. Here we show how a parasitic wasp (parasitoid) contrives to reach its host, itself an endangered species of social parasite that lives inside the brood chambers of ant nests, by releasing semiochemicals to induce in-fighting between worker ants, locking the colony in combat and leaving it underprotected. Four of these chemicals are new to biology and have the potential to control pest species by inducing different agonistic behaviours in ants.

Interspecific differences in cuticular hydrocarbon profiles of Myrmica ants are sufficiently consistent to explain host specificity by Maculinea (large blue) butterflies

The chemical signatures on the cuticles of five common Myrmica ant species were analysed (49 colonies of M. rubra, M. ruginodis, M. sabuleti, M. scabrinodis and M. schencki), each ant being the specific host of one of the five threatened European species of Maculinea butterfly. The cuticular hydrocarbon profile (based on the relative abundance of each chemical) of each ant species was highly distinctive, even between the morphologically similar species M. sabuleti and M. scabrinodis. There was no significant difference in the chemical profiles of workers and larvae from any colony. Nor was there much pattern in the intraspecific variation: colonies from the same populations were significantly, but only slightly, more similar to each other than to colonies from distant populations. M. rubra showed remarkably little variation between populations sampled widely from northern Russia, Ukraine, Scotland and southern England. The data were compared with published profiles of M. rubra and two North American Myrmica species, and with a quantitative reanalysis of data for Maculinea rebeli caterpillars. We conclude that the hydrocarbon profiles of Myrmica species are sufficiently and consistently different for chemical mimicry to explain the pattern of host specificity recorded for the European Maculinea butterflies. The optimum strategy for chemical mimicry in each of the two life-styles of Maculinea larvae is discussed: we suggest that predatory species might benefit from mimicking the median profile of their model whereas the "cuckoo" species would benefit when variation between siblings encompasses a large range of the variation recorded within a local population of the model species.

Binding of annexins to lung lamellar bodies and the PMA-stimulated secretion of annexin V from alveolar type II cells

To identify lung lamellar body (LB)-binding proteins, the fractions binding to LB-Sepharose 4B in a Ca(2+)-dependent manner from the lung soluble fractions were analyzed with Mono Q column. Four annexins (annexins III, IV, V, and VIII) were identified by partial amino acid sequence analyses as the LB-binding proteins in the lung soluble fractions. A control experiment using phospholipid (phosphatidylserine/phosphatidylglycerol/phosphtidylcholine) liposome-Sepharose 4B revealed that annexins III, IV and V were the Ca(2+)-dependent proteins binding to the column in the lung soluble fractions, while annexin VIII was not detected. Thus, annexin VIII might preferentially bind to LB. On the other hand, the only Ca(2+)-dependent LB-binding protein identified in the bronchoalveolar lavage fluids was annexin V. It was further demonstrated that annexin V was secreted by isolated alveolar type II cells from rats and that the secretion was stimulated by the addition of phorbol ester (PMA), a potent stimulator of surfactant secretion. The PMA-dependent stimulation of annexin V was attenuated by preincubation with surfactant protein-A (SP-A), a potent inhibitor of surfactant secretion. As LB is thought to be an intracellular store of pulmonary surfactant, which is secreted by alveolar type II cells, annexin V is likely to be secreted together with the lamellar body.

Elevation of carboxyl methylation activity on GTP-binding protein gamma-subunit in synovial tissues from rheumatoid arthritis: how does elevation of the methylation relate to the signal transduction system of rheumatoid arthritis?

We examined guanosine triphosphate (GTP)-binding proteins (G-proteins) in synovial tissues obtained from patients with rheumatoid arthritis or osteoarthritis. The results of immunoblot analysis with anti-bovine G-protein betagamma-subunit antibody in the rheumatoid synovial tissue were similar to those in the osteoarthritis synovial tissue. On the other hand, the carboxyl methylation activity on G-protein gamma-subunit in the rheumatoid synovial tissue was enhanced compared with that in the osteoarthritis synovial tissues: Km and Vm values were 2.6 microM and 10 pmol/mg x min, respectively, for the rheumatoid arthritis, and 4.8 microM and 5.6 pmol/mg x min, respectively, for the osteoarthritis. These results suggest that G-protein-linked signal transduction, in reference to carboxyl methylation of the gamma-subunit, is affected in rheumatoid tissues.

Differential lipid specificities of the repeated domains of annexin IV

The roles of the four domains of annexin IV in binding to phospholipids and glycolipids were assessed by analyzing the binding of a group of mutant annexins IV in which one or more of the four domains was inactivated by replacing a critical amino residue(s) (Asp or Glu) with the neutral residue Ala. The data reveal that individual annexin domains may have characteristic affinities for different lipids. In particular, inactivation of the fourth domain inhibits the binding to phosphatidylserine (PS) and phosphatidylinositol (PI) but not to phosphatidylglycerol (PG), suggesting that this domain specifically can accommodate the larger head groups of PS and PI whereas the other three domains may form more restricted binding pockets. In order to block binding to PG, domain 1, or both domains 2 and 3 must be inactivated in addition to domain 4, suggesting that all four domains may be able to accommodate the headgroup of PG to some extent. Binding to acidic glycolipids (sulfatides) was also sensitive to inactivation of domain 4. However, in the case of sulfatides the nature of the binding reaction is fundamentally different compared with the binding to phospholipids since the interaction with sulfatides was highly sensitive to an increase in ionic strength. The binding to sulfatides may depend therefore on charge-charge interactions whereas the binding to phospholipid may involve a more specific interaction between the lipid headgroup and the protein surface, and/or interaction of the protein with the hydrophobic portion of a lipid bilayer.

Importance of the carboxy-terminal 25 amino acid residues of lung collectins in interactions with lipids and alveolar type II cells

Surfactant proteins A and D (SP-A and SP-D) are structurally related members of the collectin family found in the alveolar compartment of the lung. SP-A binds dipalmitoylphosphatidylcholine (DPPC) and galactosylceramide (GalCer), induces liposome aggregation, and regulates the uptake and secretion of surfactant lipids by alveolar type II cells in vitro. SP-D binds phosphatidylinositol (PI) and glucosylceramide. The purpose of this study was to identify a critical stretch of primary sequence in the SP-A region Cys(204)-Phe(228) and the SP-D region Cys(331)-Phe(355) that is involved in protein-specific lipid and type II cell interactions. Chimeras ad1 and ad2 were constructed with rat SP-A/SP-D splice junctions at Cys(218)/Gly(346) and Lys(203)/Cys(331), respectively. Chimera ad1 but not ad2 retained DPPC liposome binding activity. Both chimeras retained significant binding to GalCer liposomes. Chimera ad1 did not bind to PI, whereas chimera ad2 acquired a significant PI binding. Both chimeras failed to induce liposome aggregation and to interact with alveolar type II cells. In addition, monoclonal antibody 1D6 that blocks specific SP-A functions did not recognize either chimera. From these results, we conclude that (1) the SP-A region Leu(219)-Phe(228) is required for liposome aggregation and interaction with alveolar type II cells, (2) the SP-A region Cys(204)-Cys(218) is required for DPPC binding, (3) the SP-D region Cys(331)-Phe(355) is essential for minimal PI binding, and (4) the epitope for mAb 1D6 is located at the region contiguous to the SP-A region Leu(219)-Phe(228).

Serial changes in surfactant-associated proteins in lung and serum before and after onset of ARDS

The goal of this study was to determine the changes that occur in surfactant-associated proteins in bronchoalveolar lavage fluid (BAL) and serum of patients at risk for ARDS and during the course of ARDS. We found that the concentrations of SP-A and SP-B were low in the BAL of patients at risk for ARDS before the onset of clinically defined lung injury, whereas the concentration of SP-D was normal. In patients with established ARDS, BAL SP-A and SP-B concentrations were low during the entire 14-d observation period, but the median SP-D concentrations remained in the normal range. Immunoreactive SP-A and SP-D were not increased in the serum of patients at risk for ARDS, but both increased after the onset of ARDS to a maximum on Day 3 and remained elevated for as long as 14 d. The BAL SP-A concentrations were significantly lower in at-risk patients who developed ARDS, and no patient with a BAL SP-A concentration greater than 1.2 microg/ml developed ARDS. On Days 1 and 3 of ARDS, the BAL SP-D concentration was significantly lower in patients who died, and the BAL SP-D concentration was significantly related to the PI(O(2))/FI(O(2)) ratio. Thus, surfactant protein abnormalities occur before and after the onset of ARDS, and the responses of SP-A, SP-B, and SP-D differ in important ways. The BAL SP-A and SP-D measurements can be used to classify patients as high or low risk for progression to ARDS and/or death after the onset of ARDS. Strategies to increase these surfactant proteins in the lungs of patients with ARDS could be useful to modify the onset or the course of ARDS.

Novel plasmalogalactosylalkylglycerol from equine brain

A novel galactosylalkylglycerol modified with a long-chain cyclic acetal at the sugar moiety, 3-O-(4'6'-plasmalogalactosyl) 1-O-alkylglycerol, was isolated from equine brain. The presence of cyclic acetal linkage, its linked position, and the length of the acetal chain of the natural plasmalo lipid were determined by proton NMR spectroscopy and fast-atom bombardment;-mass spectrometry, as well as gas chromatography;-mass spectrometry and gas;-liquid chromatography. To identify the isomeric stereostructure of the natural product, the plasmalo derivative was chemically synthesized from 3-O-galactosyl 2-O-acyl 1-O-alkyl glyceride through acetalization after deacylation. As a result, the direction and position of the acetal chain of the natural plasmalo lipid were characterized as an "endo"-type 4',6'-O-acetal derivative linked to galactoside by comparison with the NMR data of the synthesized product. The chain lengths of alkyl and acetal groups were C(14) for the former and C(16) and C(18) for the latter, and those for the latter group were mostly similar to those of plasmalogalactosyl ceramide, which was previously isolated from equine brain.

Characterization of the Ca2+-dependent binding of annexin IV to surfactant protein A

We have shown previously that surfactant protein A (SP-A) binds to annexin IV in a Ca2+-dependent manner [Sohma, Matsushima, Watanabe, Hattori, Kuroki and Akino (1995) Biochem. J. 312, 175-181]. Annexin IV is a member of the annexin family having four consensus repeats of about 70 amino acids and a unique N-terminal tail. In the present study, the functional site of both annexin IV and SP-A for the Ca2+-dependent binding was investigated using mutant proteins. SP-A bound in a Ca2+-dependent manner to an annexin-IV truncation mutant consisting of the N-terminal domain and the first three domains (T(N-1-2-3)). SP-A also bound to T3-4, but this interaction was not Ca2+-dependent. SP-A bound weakly to the other truncation mutants (T(N-1-2), T(2-3) and T(2-3-4)). Each consensus repeat of annexin IV possesses a conserved acidic amino acid residue (Glu70, Asp142, Glu226 and Asp301) that putatively ligates Ca2+. Using annexin-IV DE mutants in which one, two or three residues out of the four Asp/Glu were altered to Ala by site-directed mutagenesis [Nelson and Creutz (1995) Biochemistry 34, 3121-3132], it was revealed that Ca2+ binding in the third domain is more important than in the other Ca2+-binding sites. SP-A is a member of the animal lectin group homologous with mannose-binding protein A. The substitution of Arg197 of rat SP-A with Asp or Asn eliminated binding to annexin IV, whereas the substitution of Glu195 with Gln was silent. These results suggest that the Ca2+ binding to domain 3 of annexin IV is required for the Ca2+-dependent binding by SP-A and that Arg197 of SP-A is important in this binding.

Introduction of mannose binding protein-type phosphatidylinositol recognition into pulmonary surfactant protein A

Pulmonary surfactant protein A (SP-A) and mannose-binding protein A (MBP-A) are collectins in the C-type lectin superfamily. These collectins exhibit unique lipid binding properties. SP-A binds to dipalmitoyl phosphatidylcholine (DPPC) and galactosylceramide (GalCer) and MBP-A binds to phosphatidylinositol (PI). SP-A also interacts with alveolar type II cells. Monoclonal antibodies (mAbs PE10 and PC6) that recognize human SP-A inhibit the interactions of SP-A with lipids and alveolar type II cells. We mapped the epitopes for anti-human SP-A mAbs by a phage display peptide library. Phage selected by mAbs displayed the consensus peptide sequences that are nearly identical to 184TPVNYTNWYRG194 of human SP-A. The synthetic peptide GTPVNYTNWYRG completely blocked the binding of mAbs to human SP-A. Chimeric proteins were generated in which the rat SP-A region Thr174-Gly194 or the human SP-A region Ser174-Gly194 was replaced with the MBP-A region Thr164-Asp184 (rat ama4 or hu ama4, respectively). The mAbs failed to bind hu ama4. Rat ama4 bound to an affinity matrix on mannose-sepharose but lost all of the SP-A functions except carbohydrate binding and Ca2+-independent GalCer binding. Strikingly, the rat ama4 chimera acquired the PI binding property that MBP-A exhibits. This study demonstrates that the amino acid residues 174-194 of SP-A and the corresponding region of MBP-A are critical for SP-A-type II cell interaction and Ca2+-dependent lipid binding of collectins.

Purification and biochemical characterization of equine pulmonary surfactant protein D

OBJECTIVE

To characterize surfactant protein D (SP-D) isolated from bronchoalveolar lavage fluid (BALF) of healthy horses.

SAMPLE POPULATION

BALF from 10 Thoroughbreds (5 males, 5 females; 26 to 40 months old) without history or clinical signs of respiratory tract disease.

PROCEDURE

BALF was obtained and centrifuged at 33,000 X g. The supernatant was applied to a mannose-Sepharose 6B affinity column in the presence of calcium, and the bound protein fraction was analyzed by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblot analysis; amino acid composition was determined and partial sequencing was done. Phospholipid binding and liposome aggregation assay were performed, using purified proteins.

RESULTS

The protein isolated by use of mannose affinity matrices was SP-D. It bound carbohydrates and phosphatidylinositol, which are the characteristic features of SP-D isolated from other animal species. Amino acid analysis and partial primary sequence of the isolated protein indicated high homology with rat and human SP-D. Furthermore, immunoblot analysis indicated that equine SP-D reacted with human and rat SP-D-specific antibodies.

CONCLUSION AND CLINICAL RELEVANCE

SP-D exists in equine lungs; its measurement may be useful in evaluating equine lung disease.

Experimental neonatal respiratory failure induced by lysophosphatidylcholine: effect of surfactant treatment

The purpose of this study was to characterize the toxic effects of lysophosphatidylcholine (lyso-PC) on neonatal lung function. Various doses of lyso-PC (from 0 to 40 mg/kg) were administered to near-term newborn rabbits. Lung-thorax compliance during mechanical ventilation was significantly decreased by doses >/=10 mg/kg, and static lung volumes during deflation were decreased by doses >/=20 mg/kg. Using the same experimental model, we investigated the effects of modified porcine surfactant (Curosurf, 200 mg/kg). Animals exposed to lyso-PC at birth and treated simultaneously with surfactant showed a satisfactory therapeutic response, whereas those treated after 30 min failed to respond. These animals also had a much larger leak of albumin into the air spaces and an elevated minimum surface tension of the lavage fluid in a pulsating bubble surfactometer, suggesting inactivation of the exogenous surfactant. Timing of surfactant administration may thus be essential for the therapeutic effect in this experimental model of acute lung injury.

Purification and biochemical characterization of pulmonary surfactant protein A of horses

OBJECTIVE

To characterize surfactant protein isolated from bronchoalveolar lavage fluids of healthy horses.

ANIMALS

10 Thoroughbreds (5 males, 5 females; 26 to 40 months old) that did not have a history or clinical signs of respiratory tract disease.

PROCEDURE

Bronchoalveolar lavage fluid (BALF) was obtained and centrifuged at 33,000 X g. Lipid was removed from precipitated fractions by means of extraction with 1-butanol, and organic solvent-insoluble protein precipitates were dialyzed against Tris buffer. The suspension was centrifuged, and supernatant was placed in a mannose-Sepharose affinity column, with calcium. The bound protein fraction was analyzed by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western immunoblot analysis, and amino acid sequencing. A liposome-aggregation assay was also performed, using purified proteins.

RESULTS

Protein isolated by use of mannose-affinity matrices was identified as surfactant protein A (SP-A). It had carbohydrate-binding and phospholipid-aggregation properties characteristic of SP-A isolated from other animal species. The partial primary sequence of the isolated protein had high homology with rat and human SP-A. Furthermore, the equine SP-A reacted with anti-human and anti-rat SP-A specific antibodies.

CONCLUSION

Analysis of these findings indicated the existence of SP-A in pulmonary tissues of horses.

CLINICAL RELEVANCE

Measurement of SP-A concentrations may be useful for clinicians evaluating pulmonary disease of horses.

Antigenicity of the carbohydrate moiety of ganglioside GM3 having 3-O-acetyl ceramide

To elucidate the effect of a modification of ceramide on antigenicity of the carbohydrate of ganglioside, the reactivity of O-acetyl GM3 having 3-O-acetyl ceramide, which has been characterized as a glioma-related ganglioside, with monoclonal antibody M2590 was examined in comparison to that of non-acetylated GM3, by means of quantitative enzyme-linked immunosorbent assay, TLC-immunostaining and liposome immune lysis assay. In all these assay systems, O-acetyl GM3 showed less activity than GM3 as follows: GM3 was detected till 0.1 nmol in TLC-immunostaining, whereas O-acetyl GM3 could not be detected even at 0.25 nmol; the GM3 reaction was approximately twofold that of O-acetyl GM3 at each diluted point in the enzyme-linked immunosorbent assay; and 20% of the liposomes containing GM3 were lysed at 6 mol%, while liposomes containing O-acetyl GM3 did not lyse at that concentration. The lesser antigenicity of the sugar moiety of O-acetyl GM3 could be ascribed to the presence of an acetyl group in the ceramide at the 3-position of sphingosine.

Surfactant proteins A and D: disease markers

The abundant and restricted expression of surfactant proteins SP-A and SP-D within the lung makes these collectins specific markers for lung diseases. The measurement of SP-A and SP-D in amniotic fluids and tracheal aspirates reflects lung maturity and the production level of the lung surfactant in infants with respiratory distress syndrome (RDS). The SP-A concentrations in bronchoalveolar lavage (BAL) fluids are significantly decreased in patients with acute respiratory distress syndrome (ARDS) and also in patients at risk to develop ARDS. The prominent increase of these proteins in BAL fluids and sputum is diagnostic for pulmonary alveolar proteinosis (PAP). The concentrations of SP-A and SP-D in BAL fluids from patients with idiopathic pulmonary fibrosis (IPF) and interstitial pneumonia with collagen vascular diseases (IPCD) are rather lower than those in healthy controls and the SP-A/phospholipid ratio may be a useful marker of survival prediction. SP-A and SP-D appear in the circulation in specific lung diseases. Their serum concentrations significantly increase in patients with PAP, IPF and IPCD. The successive monitoring of serum levels of SP-A and SP-D may predict the disease activity. The serum SP-A levels increase in patients with ARDS. SP-A is also a marker for lung adenocarcinomas and can be used to differentiate lung adenocarcinomas from other types and metastatic cancers from other origins, and to detect metastasis of lung adenocarcinomas.

New blocking method for the hydroxyl group on carbohydrate. Determination of the O-acylated position of the modified glycolipid

To determine O-esterified positions, a rapid and complete acetalization to prepare an intermediate was established using ethyl vinyl ether as a new reagent. The new method was applied to O-esterified glycolipids followed by GC-MS analysis of the monosaccharide derivatives after methylation and methanolysis, revealing the derivatives with correctly substituted positions. This method was superior in terms of its shorter reaction time and complete acetalization, particularly of the N-glycolyl hydroxyl residue, to previously reported methods using methyl vinyl ether.

Characterization of a O-fatty-acylated sulfatide from equine brain

A sulfatide, O-fatty-acylated 3-sulfogalactosylceramide at C6-O on galactoside, was isolated from equine brain and the chemical structure was characterized by proton NMR and MS. The O-acylation site of the acylated sulfatide was determined by the down-field shift of protons attached to a carbon having an O-acyl group in the NMR spectrum and by analysis of a partially methylated derivative before and after acetalization of the intact sulfatide using GC-MS. The O-acyl chain length was determined by GLC, revealing that it exclusively had palmitoyl and stearoyl residues as the major fatty acids. The enzymatic conversion to the O-acyl sulfatide was further examined using equine brain microsomes as an enzyme source and different lipid substrates, resulting in O-acylation of 3-sulfogalactosylceramide from stearoyl CoA, while 6-O-acyl galactosylceramide was not O-sulfated from phosphoadenosine phosphosulfate. The results were supported by the comparably different N-linked fatty acid components between two lipid substrates, in which the component of 6-O-acyl sulfatide was mostly similar to that of sulfatide, but not to 6-O-acyl galactosylceramide.

BAL surfactant protein A and Clara cell 10-kDa protein levels in healthy subjects

Lung surfactant protein A (SP-A) and Clara cell 10-kDa protein (CC10) are the most abundant proteins produced locally in the lower respiratory tract, as assessed in bronchoalveolar lavage (BAL) analysis. However, it is not known what factors influence SP-A and CC10 levels in BAL fluids, and the relationship between SP-A and CC10 levels in BAL fluids has been unclear. We measured SP-A and CC10 concentrations in BAL fluids from 11 healthy nonsmokers and 12 healthy smokers by enzyme-linked immunosorbent assays using specific antibodies. Mean SP-A and CC10 levels in BAL fluids of healthy smokers were significantly lower than those of healthy nonsmokers. SP-A values correlated significantly with CC10 and phospholipid values in BAL fluids. On BAL examinations using three 50-ml aliquots, the mean SP-A level in the second lavage was 2.0-fold and 2.4-fold, respectively, of that in the first and third lavages, and the mean CC10 level in the first lavage was 5.0-fold and 5.6-fold, respectively, of that in the second and third lavages. We conclude that BAL fluid SP-A and CC10 levels are influenced by the BAL methods and by cigarette smoking. There is a significant positive correlation between SP-A and CC10 values in BAL fluids of healthy subjects.

Stereochemical structures of synthesized and natural plasmalogalactosylceramides from equine brain

Modified galactosylceramide with a long-chain cyclic acetal at the sugar moiety, plasmalogalactosylceramide, was isolated from equine brain. To identify the isomeric stereostructure of the natural product, the plasmalo derivative was chemically synthesized from galactosylceramide through acetalization. The presence of cyclic acetal linkage, the linked position and length of the acetal chain of the synthesized and natural products were determined by proton nuclear magnetic resonance spectroscopy and fast-atom bombardment-mass spectrometry, as well as gas chromatography-mass spectrometry and gas-liquid chromatography. The orientation of the acetal chain linked to galactoside was characterized by connectivity between the cyclic acetal proton and ring proton(s) on the sugar moiety using the homonuclear Overhauser effect. This revealed that, of the two positional isomers of the acetal linkage with 4,6-O-acetal and 3,4-O-acetal derivatives obtained from the acetalization reaction, the former positional isomer, separated into two spots, was identified to 'endo'- and 'exo'-type acetal chains. In comparison to the NMR data of the synthesized derivative, equine brain acetalized lipid was found to be an 'endo'-type 4,6-O-acetal derivative.

Substrate specificity and some other enzymatic properties of dihydroceramide desaturase (ceramide synthase) in fetal rat skin

Dihydroceramide desaturase, which catalyzes the introduction of a double bond at the 4,5-position of the sphingosine base in a dihydroceramide, was assayed in vitro using radiolabeled D-erythro-C18-dihydroceramide (N-stearoyl sphinganine) and homogenates of fetal rat skin, and some enzymatic properties, including substrate specificity, were determined. The ceramide structure, as the enzymatic product, was confirmed by (i) oxidation of the product with 2,3-dicyano-5,6-dichlorobenzoquinone, which revealed the conversion to 3-ketoceramide (3,3'-didehydroceramide), indicating that a double bond was introduced at the adjacent to the C-3 hydroxyl residue of sphinganine, and (ii) mass spectrometry of a long chain base released from the enzymatic product, which revealed a spectrum identical to that of authentic sphingenine. A short chain dihydroceramide, which was radiolabeled at sphinganine through a newly established method, having a C2- or C6-fatty acid was not desaturated by the skin enzyme, whereas that having a C10-, C14-, or C18-acid was desaturated, maximal reactivity being observed for the C14-dihydroceramide. Other enzymatic properties were confirmed: NAD(H) or NADP(H) and a detergent were required for elevation of the activity; the optimum pH was approximately 6.7; and metal cations were not essential, but Zn2+, Cu2+, and Fe2+ were rather inhibitory. These properties of rat skin desaturase were partly similar to those of rat liver microsomes, as reported recently, however, their substrate specificities were different.

Revascularized intercalary bone allografts with short-term immunosuppression with cyclosporine in the canine

To study the healing process of vascularized intercalary bone allograft after withdrawal of immunosuppressive drugs, allotransplantation of the tibia diaphysis with a vascular pedicle was performed in eight adult mongrel dogs (group 2) and assessments were made both during administration and after discontinuation of cyclosporin A. As controls, similar grafts with the vascular pedicles were removed and reimplanted back to the same animals (five dogs, group 1). Allotransplantation of frozen stored bone without a vascular pedicle (10 dogs, groups 3A and 3B) were also compared. No union occurred in most cases of frozen stored bone allotransplant because the transplanted bone was resorbed, leading to loosening and subsequent failure of osteosynthesis with the plate and screws used. Under cyclosporin A immunosuppression, bony union (i.e., when trabeculae were seen crossing the graft-recipient junction with obliteration of the junction line) occurred at almost similar time intervals in all dogs of group 2 (bone allotransplant with a vascular pedicle) by 3 months postoperatively, which was similar to those of group 1. No systemic side effects of cyclosporin A were observed. Cyclosporin A was discontinued 3 months following graft implantation. The bone graft became avascular within a week following withdrawal of cyclosporin A. However, bone union was maintained, and the transplanted bone never showed bone resorption, sclerosis, or fracture on serial radiographs up to the time the animals were sacrificed, between 5 and 14 months later. Histology at sacrifice showed that the transplanted allografts were being replaced at both ends by fresh bone derived from the transplantation bed. We conclude on the basis of the results of this study that solid bony union can be obtained in allotransplanted bone with a vascular pedicle if cyclosporin A is given for a brief period. After cyclosporin A is withdrawn, although the bone becomes nonviable secondary to rejection occurring in the blood vessels, its skeletal structure remains intact, enabling it to maintain its structural support while awaiting replacement by bony ingrowth from both ends of the graft.

Further characterization of equine brain gangliosides: the presence of GM3 having N-glycolyl neuraminic acid in the central nervous system

Equine brain gangliosides were isolated and their structures were characterized, to examine whether equine brain has N-glycolyl neuraminic acid in gangliosides, since other mammals predominantly possess N-acetyl neuraminic acid in brain gangliosides, and equine erythrocytes and organs except the brain have gangliosides exclusively containing N-glycolyl neuraminic acid. The gangliosides purified from the brain were identified by proton NMR spectroscopy and mass spectrometry, as well as GLC, resulting in their identification as GM4, GM3, GM2, GM1, GD1a, GD1b, and GT1b. Of these gangliosides, GM3 possessed N-glycolyl neuraminic acid as a minor component (18% of the total GM3), whereas other gangliosides exclusively contained N-acetyl neuraminic acid. The N-glycolyl neuraminic acid residue of the GM3 was confirmed by TLC immunostaining. The possibility of contamination of the GM3 by erythrocytes was eliminated based on the finding that the lipid compositions were characteristic of brain gangliosides. The presence, even as a minor component, of the N-glycolyl neuraminic acid in equine brain gangliosides is exceptional among the sialic acid species in mammalian central nervous system.

Analysis of chimeric proteins identifies the regions in the carbohydrate recognition domains of rat lung collectins that are essential for interactions with phospholipids, glycolipids, and alveolar type II cells

Pulmonary surfactant proteins A (SP-A) and D (SP-D) are collectins in the C-type lectin superfamily. SP-A binds to dipalmitoylphosphatidylcholine and galactosylceramide, and it regulates the uptake and secretion of surfactant lipids by alveolar type II cells. In contrast, SP-D binds to phosphatidylinositol (PI) and glucosylceramide (GlcCer). We investigated the functional region in the carbohydrate recognition domain of rat SP-A and SP-D that is involved in binding lipids and interacting with alveolar type II cells by using chimeric proteins. Chimeras ad3, ad4, and ad5 were constructed with SP-A/SP-D splice junctions at Gly194/Glu321, Gln173/Thr300, and Met134/Cys261, respectively. All three chimeras lost SP-A-specific functions. Chimeras ad3, ad4, and ad5 bound to PI with increasing activity. In contrast, chimeras ad3 and ad4 did not bind to GlcCer, whereas ad5 avidly bound this lipid. From these results, we conclude that 1) the SP-A region of Glu195-Phe228 is required for lipid and type II cell interactions, 2) the SP-D region of Cys261-Phe355 is required for optimal lipid interactions, and 3) the structural requirement for the binding of SP-D to PI is different from that for GlcCer.

Treatment of chronic regional pain syndrome using manipulation therapy and regional anesthesia

In a 4-year period, 17 consecutive patients with posttraumatic chronic regional pain syndrome were treated with a new technique, Movelat manipulation therapy. At average follow-up of 8 months, satisfactory results were achieved in 15 patients (88%), but 2 patients, 1 with digital nerve injury and 1 with ulnar nerve injury, did not respond to the therapy. Factors associated with good clinical response include chronic regional pain syndrome type I, i.e., dystrophy produced by a trauma to the hand but not involving a specific nerve injury, early-stage disease (within 3 months after trauma), and involvement of the upper limbs. Complications were rare and mild (pain over the tourniquet site in 3%, temporary dizziness in 1%). This therapy is simple and safe and recommended for early treatment of chronic regional pain syndrome.

Longer survival of rat limb allograft. Combined immunosuppression of FK-506 and 15-deoxyspergualin

We studied the individual and synergistic effect of 3 immunosuppressive drugs, FK-506 (1 mg/kg/day), 15-deoxyspergualin (2.5 mg/kg/day) and cyclosporine (15 mg/kg/day) in a DA/Lewis rat limb allotransplantation model. 74 right hindlimb transplantations were performed. The median time for onset of rejection was 4 days in animals without immunosuppression, 37 days in animals receiving cyclosporine immunosuppression for 30 days, 61 days in animals receiving FK-506 for 30 days, 36 days in animals receiving a 30-day course of cyclosporine and, in the first 15 days, a course of 15-deoxyspergualin, and 76 days in animals receiving a 30-day course of FK-506 and 15-deoxyspergualin in the first 15 days. The combination of cyclosporine with 15-deoxyspergualin did not prolong graft survival and no synergistic effect was evident. In contrast, survival time in rat limb allografts receiving FK-506 and 15-deoxyspergualin was longer than in those receiving single FK-506 therapy. Our findings suggest a positive synergistic immunosuppressive effect with FK-506 and 15-deoxyspergualin in limb allotransplantation.

Enzyme-linked immunosorbent assay using F(ab')2 fragment for the detection of human pulmonary surfactant protein D in sera

We developed an enzyme-linked immunosorbent assay (ELISA) for detection of SP-D in serum using recombinant SP-D as a standard and horseradish peroxidase conjugated F(ab')2 fragment of mouse monoclonal antibody IgG to avoid the interaction of serum factors including rheumatoid factor. The use of F(ab')2 fragment dramatically decreased the value of serum SP-D concentration in rheumatoid arthritis patients without pulmonary complication to the close level of healthy volunteer. In contrast, the patients with collagen disease having interstitial pulmonary pneumonia exhibited consistently elevated levels of serum SP-D. The use of new ELISA with recombinant SP-D and F(ab')2 fragment of anti-SP-D monoclonal antibody gives a greater advantage for the accurate detection of SP-D in sera from patients with idiopathic pulmonary fibrosis, interstitial pneumonia with collagen disease and pulmonary alveolar proteinosis without interference of rheumatoid factor.

A novel type of binding specificity to phospholipids for rat mannose-binding proteins isolated from serum and liver

Mannose-binding protein (MBP) belongs to the collectin subgroup of C-type lectins with specificity for mannose and N-acetylglucosamine sugars. We investigated whether rat MBPs isolated from serum (S-MBP) and liver (L-MBP) interact with phospholipids using antibody against each MBP. Both S- and L-MBPs bound to phosphatidylinositol coated onto microtiter wells in a concentration- and a Ca2+-dependent manner. L-MBP also bound to phosphatidylglycerol and weakly to phosphatidylserine. MBPs interacted with liposomes composed of these lipids. S- and L-MBPs bound to phosphatidylinositol 4-monophosphate. L-MBP also bound to cardiolipin. These results provide evidence for a novel type of ligand binding specificity for MBPs, and raise the possibility that phospholipids are ligands for collectins.

Occurrence of nonenzymatic N-acetylation of sphinganine with acetyl coenzyme A producing C2-H2-ceramide and its inconvertibility to apoptotic C2-ceramide

Sphinganine, a biosynthetic precursor of ceramide, was non-enzymatically acetylated with acetyl coenzyme A at the C-2-amino residue to produce C2-H2-ceramide (N-acetyl sphinganine) in an organic solvent and in an aqueous solution with a high yield, whereas sphingenine was only acetylated slightly. The structure of the N-acetyl sphinganine was identified with mass spectrum, and with chromatography using an authentic N-acetylated substance. Furthermore, the C2-H2-ceramide was examined for enzymatic desaturation to determine whether C2-ceramide, a cell-permeable ceramide responsible for apoptosis of cells, was produced, revealing an inferior substrate for H2-ceramide desaturase of horse brain microsomes.

The mannose-binding protein A region of glutamic acid185-alanine221 can functionally replace the surfactant protein A region of glutamic acid195-phenylalanine228 without loss of interaction with lipids and alveolar type II cells

Pulmonary surfactant protein A (SP-A) is a C-type lectin that regulates the uptake and secretion of surfactant lipids by alveolar type II cells and binds dipalmitoylphosphatidylcholine (DPPC) and galactosylceramide (GalCer). We isolated mannose-binding protein A (MBP-A) from rat sera, which is structurally analogous to SP-A, and examined if it was functionally equivalent to SP-A. We found that MBP-A did not possess the ability to interact with lipids and type II cells. The purpose of this study was to investigate the SP-A region involved in binding lipids and interacting with type II cells by using chimeric proteins with MBP-A. Chimeras AM1, AM2, and AM3 were constructed with SP-A/MBP splice junctions at Cys218/Gln210, Lys203/Cys195, and Gly194/Glu185, respectively. All of the chimeras bound DPPC and GalCer with activity comparable to recombinant SP-A. The three chimeras retained the ability to induce phospholipid vesicle aggregation and augment lipid uptake by type II cells, albeit to a lesser extent than wild type SP-A. The chimeras inhibited lipid secretion from type II cells with an IC50 of 0.5 microg/mL and competed effectively for SP-A receptor binding. In addition all these chimeras contained the epitope for monoclonal antibody 1D6, which blocks specific SP-A function. From these results, we conclude that the MBP-A region of Glu185-Ala221 can functionally replace the homologous SP-A region of Glu195-Phe228 without loss of interaction with lipids and type II cells.

Immunoglobulin G is associated with surfactant protein A aggregate isolated from patients with pulmonary alveolar proteinosis

We have previously shown that the purified preparation of surfactant protein A (SP-A) isolated from patients with pulmonary alveolar proteinosis (PAP) contains a very small amount of immunoglobulin G (IgG). We have recently found that there exists an abnormal multimerized form (alveolar proteinosis protein-I, APP-I) in SP-As isolated from patients with PAP in addition to normal-sized octadecameric APP-II. We examined which of the populations of APP that IgG is associated with. The APP was purified by mannose-affinity column followed by gelfiltration over Bio Gel A5m after the delipidation with 1-butanol. Analysis by gel filtration over Bio Gel A15m showed two elution peaks of APP-I and APP-II. When the fractions eluted from the Bio Gel A15m column were coated onto microtiter wells and reacted with HRP-labeled antihuman IgG, the elution peak of IgG was superimposed on that of APP-I but not on that of APP-II. The immunoblotting analysis also revealed that a very small amount of IgG, which could not be detected by staining with Coomassie blue or amido black, was associated with APP-I but not with APP-II or normal SP-A. APP-I bound to nonimmune IgG coated onto microtiter wells in a concentration-dependent manner, whereas APP-II, normal human SP-A, and rat SP-A exhibited almost no binding to IgG. The results indicate an unusual property of SP-A during the diseased state.

In vivo anti-tumour effect of 3'-sulphonoquinovosyl 1'-monoacylglyceride isolated from sea urchin (Strongylocentrotus intermedius) intestine

Extracts from sea urchin intestine were screened for new anti-tumour drugs. Four glycolipids, 3'-sulphonoquinovosyl-1', 2'-diacylglyceride (A-4), 3'-sulphonoquinovosyl-1'-monoacylglyceride (2'-lyso A-4, A-5), NeuGc(alpha)2-6Glc(beta)1-1ceramide (A-6) and HSO3-8NeuGc(alpha)2-6Glc(beta)1-1ceramide (A-7), were isolated from the intestine of sea urchin, Strongylocentrotus intermedius, and characterized by means of proton nuclear magnetic resonance spectroscopy and fast atom bombardment mass spectrometry. When tested for cytotoxic activity against tumour cells in vitro, A-5 showed significant activity, but A-4, -6 and -7 did not. In addition, the hydrophilic derivatives of A-4 or -5 had no cytotoxicity. Furthermore, the anti-tumour effects on nude mice bearing solid tumours of a human lung adenocarcinoma cell line A-549 were evaluated in vivo using A-4 and -5. As a result, A-5 was found to be significantly effective in suppressing the growth of solid tumours, whereas A-4 had no effect. Pathologically, the solid tumours showed haemorrhagic necrosis areas after treatment with A-5. In this study, we have demonstrated the anti-tumour effect of sulphonoquinovosyl-lysoglyceride (A-5), which provides important information that this sulpholipid could be a useful drug for cancer chemotherapy.

[Surfactant protein A in bronchoalveolar lavage fluid from patients with idiopathic interstitial pneumonia]

We measured the levels of surfactant protein A (SP-A) in bronchoalveolar lavage fluid from patients with idiopathic interstitial pneumonia and from healthy volunteers. The SP-A levels in the patients who were smokers (1.4 +/- 0.2 micrograms/ml) were significantly (p < 0.05) lower than those in the patients who were nonsmokers (3.0 +/- 0.5 micrograms/ml). However, SP-A levels did not differ significantly between patients and volunteers who were smokers, or between patients and volunteers who were nonsmokers. The ratios of SP-A to phospholipid in patients who were smokers and in those who were non-smokers did not differ significantly from those in volunteers who were smokers and volunteers who were non smokers. The total number of alveolar macrophages in bronchoalveolar lavage fluid did not significantly correlate with the level of SP-A, although the percentage of alveolar macrophages correlated negatively (p < 0.05) with the level of SP-A. The low level of SP-A in patients with idiopathic interstitial pneumonia who are smokers may weaken the host defense functions in peripheral airways and may contribute to the poor outcomes in these patients.

Synthesis of a glioma-related ganglioside, O-Ac GM3 having 3-O-Ac ceramide and its substrate property toward hydrolases

An O-acetyl group was selectively introduced into the ceramide moiety at the C-3-O on ganglioside GM3 containing N-acetyl neuraminic acid, the product of which has been previously found in rat glioma tissue as a glioma-associated ganglioside. The introduction of the acetyl residue involved a two-step process involving per O-acetylation of GM3 and saponification with a mild alkaline solution in a bilayer system constituted of water and water-immiscible organic solvent. Of the several solvents studied, 2-pentanol and diethyl ether gave the highest yields (68% and 62%, respectively). The chemical structure of the synthesized 3-O-acetyl GM3 was confirmed by proton nuclear magnetic resonance spectroscopy and fast atom bombardment-mass spectrometry, as well as by comparing the mobilities on thin-layer chromatography of its exoglycosidase-digested products with those of the synthesized, authentic 3-O-acetyl-lactosylceramide and ceramide. Furthermore, the substrate specificities of both 3-O-acetyl GM3 and 3-O-acetyl sphingomyelin toward exo- and endo-hydrolases were examined, revealing that they were hardly cleaved by the endoglycoceramidase and sphingolipid N-deacylase for the 3-O-acetyl GM3 and by sphingomyelinase for 3-O-acetyl sphingomyelin. Thus, the enzymes were found to recognize a free C-3 hydroxyl group on ceramide.

Nerve-regenerating effect of 15-deoxyspergualin. Peripheral nerve allotransplants in the rat

We studied the effect of two immunosuppressive agents, 15-deoxyspergualin and cyclosporine A, on various nerve allografts in inbred rats whose major histocompatibility complex was mismatched. As allografts, we used the sciatic nerve (20 mm) and the saphenous nerve (20 mm). We found that 1) fresh peripheral nerve allografts with a short course of 15-deoxyspergualin and cyclosporine A therapy induced more regenerated axons than autografts did, 2) a short course of 15-deoxyspergualin therapy provided better nerve regeneration than cyclosporine A therapy in all forms of nerve allografts and large caliber nerve allografts induced more regenerated axons.

Human surfactant protein A with two distinct oligomeric structures which exhibit different capacities to interact with alveolar type II cells

The lung lavage fluids from patients with pulmonary alveolar proteinosis have been generally used as a source for human surfactant protein A (SP-A). We have recently found that a multimerized form of SP-A oligomer (alveolar proteinosis protein-I, APP-I) exists besides the normal-sized octadecamer (APP-II) in SP-As isolated from the patients. When analysed by Bio-Gel A15m column chromatography in 5 mM Tris buffer (pH 7.4), the apparent molecular masses of APP-I and APP-II were 1.65 MDa and 0.93 MDa, respectively. Gel-filtration analysis also revealed that APP-II is clearly separated from APP-I in the presence of 2 mM Ca2+ and 150 mM NaCI. We investigated the abilities of both SP-A oligomers to regulate phospholipid secretion and to bind to alveolar type II cells. Although APP-I inhibited lipid secretion, it was clearly a less effective inhibitor than APP-II. IC50 for inhibition of lipid secretion was apparently 0.23 +/- 0.08 microgram/ml (0.14 +/- 0.05 nM) and 0.055 +/- 0.019 microgram/ml (0.059 +/- 0.020 nM) for APP-I and APP-II, respectively. Both proteins bound to monolayers of type II cells in a concentration-dependent manner; however, APP-I clearly had a lower affinity to bind to type II cells. The apparent dissociation contants were, K(d) = 2.31 +/- 0.70 microgram/ml (1.40 +/- 0.43 nM) and 0.89 +/- 0.22 microgram/ml (0.95 +/- 0.24 nM) for APP-I and APP-II, respectively. Excess unlabelled rat SP-A replaced 45% of 125I-APP-I and 77% of 125I-APP-II for type II cell binding. Although 125I-APP-II competed with excess unlabelled APP-I or APP-II, 125I-APP-I failed to compete and instead its binding rather increased in the presence of unlabelled APPs. The biotinylated APP-I bound to APP-I and APP-II coated on to microtitre wells in a concentration-dependent manner, indicating that APP-I interacts with APPs. This study demonstrates that the multimerized form of human SP-A oligomer exhibits the following attributes: (1) the reduced capacity to regulate phospholipid secretion from type II cells, and (2) lower affinity to bind to type II cells, and that the integrity of a flower-bouquet-like octadecameric structure of SP-A oligomer is important for the expression of full activity of this protein, indicating the importance of the oligomeric structure of mammalian lectins with collagenous domains.

Surfactant protein A accumulating in the alveoli of patients with pulmonary alveolar proteinosis: oligomeric structure and interaction with lipids

Pulmonary alveolar proteinosis (PAP) is a diffuse lung disease of unknown etiology in which the alveoli and terminal bronchioles of the lung fill with large amounts of surfactant-rich lipoproteinaceous materials. Its major pathologic manifestations are a small number of normal tubular myelin structures and an unusual abundance of multilamellated structures. Since surfactant protein A (SP-A) plays an important role in surfactant phospholipid homeostasis, we investigated the structural features of SP-A oligomers (alveolar proteinosis protein, APP) accumulating in the alveoli of individuals with PAP, and examined the abilities of APP to interact with lipids. Analysis of APP by Bio Gel A15m column chromatography revealed that it was composed of two protein peaks, one of which (APP-I) eluted at the position near that of blue dextran whereas the other (APP-II) eluted far behind blue dextran but ahead of thyroglobulin. These populations of APP showed almost identical amino acid compositions. Electron microscopic observations of APP molecules using the rotary shadow technique revealed that APP-II was observed as hexameric particles, presumably consisting mainly of octadecamers whose diameter was approximately 30 nm. The population seen for APP-II was similar to that seen for SP-A from healthy individuals. In contrast, APP-I was observed as multimerized larger aggregates whose diameter appeared to be about 70 to 90 nm. Both APP-I and APP-II retained the abilities to bind dipalmitoylphosphatidylcholine (DPPC). They also induced phospholipid vesicle aggregation in a concentration-dependent manner. The maximal turbidity for light scattering induced by APP-I and APP-II was almost equivalent when analyzed as a function of molar concentration. In vitro reconstitution experiments with porcine surfactant protein B (SP-B) and phospholipids revealed that the multilamellated membranes in structures formed from APP-I consisted of several layers of doubled unit membranes. APP-I failed to form tubular myelin structures. In contrast, APP-II formed well-formed lattice structures seen in tubular myelin. From these data we conclude that there exists an abnormal multimerized form of SP-A oligomer in the alveoli of patients with PAP, and that this unusual subpopulation of SP-A oligomer exhibits abnormal function on phospholipid membrane organization.

Interaction of phospholipid liposomes with plasma membrane isolated from alveolar type II cells: effect of pulmonary surfactant protein A

Pulmonary surfactant protein A (SP-A) augments the uptake of phospholipid liposomes containing dipalmitoylphosphatidylcholine (DPPC) by alveolar type II cells. The SP-A-mediated uptake process of lipids by type II cells have not been well understood. In the present study we investigated the SP-A-mediated interaction of phospholipids with plasma membrane isolated from alveolar type II cells. SP-A increased the amount of liposomes containing radiolabeled DPPC associated with type II cell plasma membrane by 4-fold compared to the control without SP-A when analyzed by sucrose density gradient centrifugation. This effect is dependent upon the SP-A concentration. The enhancement was inhibited by anti-SP-A antibody and EGTA. When type II cell plasma membrane and liposomes containing [14C]DPPC and [3H]triolein were coincubated with or without SP-A, analysis on sucrose density gradients revealed that the profiles of [14C]DPPC and [3H]triolein in each fraction were almost identical with or without SP-A, indicating that SP-A mediates the binding of liposomes to plasma membrane but not transfer of DPPC. SP-A increased the association of liposomes containing DPPC with the membrane by 2-fold more than that containing 1-palmitoyl-2-linoleoyl-phosphatidylcholine (PLPC). SP-A induced aggregation of phospholipid liposomes containing PLPC as well as those containing DPPC, but the final turbidity of DPPC liposomes aggregated by SP-A was only by 15% greater than that of PLPC liposomes. The amount of DPPC liposomes associated with the plasma membrane derived from type II cells was 2-fold greater than that from liver. We speculate that the SP-A-mediated interaction of lipids with type II cell plasma membrane may contribute, in part, to the lipid uptake process by type II cells.

Decreased contents of surfactant proteins A and D in BAL fluids of healthy smokers

Hydrophilic surfactant proteins, surfactant protein A (SP-A) and surfactant protein D (SP-D), have important roles in modulating the host defense functions in the peripheral airways. It has been reported that cigarette smoke may alter the component and function of pulmonary surfactant. In this study, we determined the contents of SP-A and SP-D in BAL fluids of healthy smokers and nonsmokers by enzyme-linked immunosorbent assay using monoclonal antibodies against each protein. The contents of SP-A and SP-D in BAL fluids were significantly (p<0.05) decreased in smokers compared to those in nonsmokers, although there was no significant difference of total phospholipid content between smokers and nonsmokers. These results suggest that the decreased levels of SP-A and SP-D in smokers may impair the host defense functions of surfactant in the peripheral airways and might have a crucial roles in the development of chronic obstructive lung disease.

The differences in the expressions of visual pigments and transducin in photoreceptor cell differentiation

The distribution and accumulation of visual pigments, i.e., rod pigment, rhodopsin and red sensitive cone pigment, iodopsin, and transducin in the retina of chicken and chicken embryo were investigated immunohistochemically using their specific antibodies. The immunoreactivities of these proteins appeared at the early stage of photoreceptor differentiation (embryonal day 15) and increased in the photoreceptor cells appeared to reach maximum at the end of the embryonal period (embryonal day 20). On the other hand, although the immunoreactivity of beta gamma subunit of transducin (T beta gamma) was detected at embryonal day 15, the expression level of T beta gamma still remained in low level during the embryonal period. These observations suggest that both T beta gamma and visual pigments are expressed during the embryonic period in chicken photoreceptor cells, but their accumulations in the cells are different.

Lipid analysis and surfactant-associated protein expression in lung adenocarcinoma cells from pleural effusion

Primary lung adenocarcinomas originate from the progenitor cells of peripheral airway cells. Alveolar type II cells and Clara cells are the major progenitor cells of peripheral airway cells. Alveolar type II cells produce a lipid-protein complex called surfactant, which contains surfactant proteins SP-A, SP-B, SP-C and SP-D. Phosphatidylcholine (PC) and phosphatidylglycerol (PG) are believed to be essential for the surfactant function. Clara cells also express SP-A, SP-B and SP-D but not SP-C. In this study we examined the properties of the cancer cells isolated from the pleural effusion of a patient with primary lung adenocarcinoma by analyzing lipids, proteins and mRNAs. The cancer cells, designated as LC117 cells, were isolated from the pleural effusion of a patient with primary lung adenocarcinoma. The percent distributions of [14C]-acetate incorporated into PC and PG in the cancer cells were 55.7 and 1.1%, respectively. The disaturated species in total PC was 46.2%. Immunoblotting analysis using anti-SP-D monoclonal antibody revealed that the pleural effusion from a patient with lung adenocarcinoma contained SP-D. We determined the concentrations of SP-A and SP-D by enzyme-linked immunosorbent assay. The pleural effusions from this patient and the media incubated with cancer cells exhibited significant levels of SP-D as well as SP-A. Reverse transcriptase-polymerase chain reaction demonstrated that the tumor cells expressed mRNAs for SP-C as well as the other surfactant proteins. The results demonstrate that tumor cells from lung adenocarcinoma express all of surfactant-associated proteins, indicating that LC117 cells originate from alveolar type II cells. This study indicates that the combination of analyses of lipids, proteins and mRNAs in the cancer cells isolated from pleural effusion is useful to understand the property of lung adenocarcinoma.

Overexpression of surfactant protein SP-A, SP-B, and SP-C mRNA in rat lungs with lipopolysaccharide-induced injury

Regeneration of alveolar epithelial cells is one of the important repair processes in many types of lung injury. We have examined sequential analysis of histopathology and gene expressions of surfactant protein A (SP-A), SP-B, and SP-C mRNA in alveolar type II cells of rats with lipopolysaccharide-induced (LPS-induced) lung injury. A small dose (1 to 2 mg/kg) of LPS was injected by intratracheal instillation in adult rats, and after a given period, the lungs were processed for examination using light and electron microscopy, for immunohistochemical study using anti-bromodeoxyuridine (anti-BrdU) and anti-SP-A antibodies, and for in situ hybridization using type-specific, surfactant cDNA probes. Northern blot analysis was also performed. From 3 to 7 days after LPS administration, alveolar septa were thickened, with increased numbers of epithelial and interstitial cells. BrdU-incorporated cells apparently increased in number in these areas, and many alveolar epithelial cells were intracellularly immunoreactive to anti-SP-A antibody, with many lamellar bodies found on examination using electron microscopy. By in situ hybridization, the number of autoradiographic silver grains for SP-A, SP-B, and SP-C mRNA increased strikingly, in alveolar type II epithelial cells of the lungs from LPS-administered rats. These responses of surfactant gene expression to LPS seemed to be stronger in alveolar epithelial cells than in the bronchiolar epithelium. By Northern blot analysis, the relative abundances of SP-A, SP-B, and SP-C mRNA were also higher in the LPS-administered lungs and correlated well with the results of in situ hybridization. The present study demonstrates that intratracheal administration of LPS induces the marked proliferation of alveolar epithelial cells in association with the concurrently increased SP-A, SP-B, and SP-C mRNA, as well as the SP-A production in the early response to lung injury. These results suggest that proliferation and differentiation of alveolar epithelial cells may play important roles in the repair process of the damaged alveoli after acute lung injury.

Pulmonary surfactant protein D in sera and bronchoalveolar lavage fluids

Pulmonary surfactant protein D (SP-D) is a hydrophilic glycoprotein with a reduced molecular mass of 43 kDa and a member of the C-type lectin superfamily, along with mannose-binding proteins and surfactant protein A (SP-A). We have recently prepared monoclonal antibodies against human SP-D and developed an enzyme-linked immunosorbent assay (ELISA). In this study, the levels of SP-D in sera and bronchoalveolar lavage (BAL) fluids of patients with lung diseases were determined by ELISA, using human recombinant SP-D as a standard. We demonstrated that the concentrations of SP-D in sera are prominently increased in patients with idiopathic pulmonary fibrosis (IPF), interstitial pneumonia with collagen disease (IPCD), and pulmonary alveolar proteinosis (PAP). Patients with IPF, IPCD, and PAP exhibited levels of serum SP-D 5.1-fold, 7.2-fold, and 7.0-fold, respectively, of those in healthy volunteers; 91.5% of the patients with IPF, 81.3% with IPCD, and 100% with PAP exhibited serum SP-D levels that exceeded the cut-off value (mean + 2 SD of control value). Serum SP-D levels appeared to reflect the disease activity of IPF and IPCD and the disease severity of PAP. High levels of SP-D in BAL fluids were shown in patients with PAP, but not with IPF and IPCD. We conclude that measurement of SP-D in sera can provide an easily identifiable and useful clinical marker for the diagnosis of IPF, IPCD, and PAP, and can predict the disease activity of IPF and IPCD and the disease severity of PAP.

Pulmonary surfactant subfractions in patients with the acute respiratory distress syndrome

Changes in the surfactant system have been observed in patients with acute respiratory distress syndrome (ARDS). These alterations in surfactant are thought to contribute to lung dysfunction in this disease. In this report we describe the changes in surfactant subfractions in bronchoalveolar wash obtained from five patients with established ARDS compared with five non-ARDS patients. Our results show that, in addition to the changes in surfactant composition and yield reported previously, the ratio of small to large surfactant aggregates is significantly increased in patients with ARDS compared with non-ARDS patients (0.48 +/- 0.09 versus 0.20 +/- 0.05 respectively [p < 0.05]). This increased ratio was associated with a decreased level of SP-A in the large aggregate fraction. We suggest that this increased ratio represents a marker for surfactant alterations in ARDS that is independent of lavage technique and can be measured in a very small surfactant sample.

Ca(2+)-dependent binding of annexin IV to surfactant protein A and lamellar bodies in alveolar type II cells

Surfactant protein A (SP-A), a lung-specific glycoprotein in pulmonary surfactant, is synthesized and secreted from the alveolar type II cells. It has been shown that SP-A is a Ca(2+)-binding protein with several binding sites and that the high-affinity site(s) is located in the C-terminal region of SP-A. In the present study we isolated the proteins from bovine lung soluble fraction that bind to SP-A in a Ca(2+)-dependent manner using DEAE-Sephacel and SP-A-conjugated Sepharose 4B. At least three different protein bands with molecular masses of 24.5, 32, and 33 kDa were observed on SDS/PAGE. The main protein, with molecular mass of 32 kDa, was identified as annexin IV by the partial-amino-acid-sequence analyses and an immunoblot analysis with anti-(annexin IV) antiserum. We also found from the immunoblot analysis that the cytosolic fraction of isolated rat alveolar type II cells contains annexin IV. In addition, when rat lung cytosol was loaded on to the lung lamellar body-conjugated Sepharose 4B in the presence of Ca2+, two proteins, with molecular masses of 32 and 60 kDa on SDS/PAGE respectively, were eluted with EGTA. The 32 kDa protein was shown to be annexin IV by an immunoblot analysis with the antiserum against annexin IV. The lung annexin IV augmented the Ca(2+)-induced aggregation of the lung lamellar bodies from rats. However, the augmentation of aggregation of the lung lamellar bodies by annexin IV was attenuated when the lamellar bodies were preincubated with polyclonal anti-SP-A antibodies. SP-A bound to annexin IV under conditions where contaminated lipid was removed. These results suggest that SP-A bound to annexin IV based on protein-protein interaction, though both proteins are phospholipid-binding proteins. All these findings suggest that the interaction between SP-A and annexin IV may have some role in alveolar type II cells.

Prenatal dexamethasone and exogenous surfactant therapy: surface activity and surfactant components in airway specimens

To explain some of the effects of prenatal glucocorticoid treatment on lung function, surfactant parameters in the airway specimens of ventilator-dependent preterm infants were analyzed. In this double-blind study, the mothers of these infants had received dexamethasone (DEX) or placebo prenatally. Human surfactant was given for the treatment of moderate to severe respiratory distress syndrome. Seventy-six preterm infants with mean gestational age of 29 wk and mean birth weight of 1137 g were studied. The concentrations of surfactant components in epithelial lining fluid (ELF) were analyzed, and the surface activity was measured using a pulsating bubble method. Prenatal DEX treatment increased the responsiveness to exogenous surfactant and decreased the severity of respiratory failure during the first day of life. The treatment had no effect on the concentrations of surfactant phospholipids that were generally high. Prenatal DEX treatment increased the association between phospholipid concentration in ELF and the degree of respiratory failure. Prenatal DEX improved the surface activity of surfactant isolated from airway specimens and tended to increase the ratio of surfactant protein A to phosphatidylcholine among recipients of exogenous surfactant. A subgroup of infants, offspring of mothers with severe hypertension had an abnormally low concentration of surfactant protein A and a poor outcome, despite prenatal DEX treatment or surfactant substitution. Prenatal DEX decreased the concentration of nonsedimentable proteins in ELF and decreased the inhibition of surface activity by these proteins. Our results indicate that improved surfactant function during the first day of life explains some of the beneficial pulmonary effects of prenatal glucocorticoid treatment in preterm infants who are ventilator-dependent.

[Clinical significance of levels of lung surfactant protein A in serum, in various lung diseases]

To assess the utility of measuring lung surfactant protein A (SP-A) in serum, a newly developed SP-A kit (Teijin TDR-30) was used at four facilities to measure serum SP-A levels in patients with various lung diseases. Serum SP-A levels in healthy volunteers were 24.6 +/- 9.6 ng/ml (mean +/- SD). serum SP-A levels did not differ significantly between different age groups (thirties through seventies). A cut-off level of 43.8 ng/ml was calculated, based on the values of the healthy volunteers. The serum SP-A levels in patients with idiopathic interstitial pneumonia (IIP: 67.9 +/- 42.5 ng/ml), pulmonary alveolar proteinosis (PAP: 7.0 +/- 45.7 ng/ml), and collagen disease with interstitial pneumonia (CDIP: 55.3 +/- 37.9 ng/ml) were significantly higher than those in healthy volunteers. When calculated with the cut-off value stated above, the positive rate of diagnosis for IIP was 71.4%. SP-A levels correlated closely with the clinical course; SP-A levels rose significantly during exacerbations of IIP. Measurement of SP-A in serum is useful for the diagnosis of IIP, PAP, and CDIP, and for monitoring exacerbations of IIP.