The hepatic metabolism of two carcinogenic dimethylbenz[c]acridines in control and induced rats: the distribution and the mutagenicity of metabolites

The major and minor metabolites of the potent polycyclic aza-aromatic carcinogens 7,9-dimethylbenz[c]acridine and 7,10-dimethylbenz[c]acridine, and the stereochemistry of the dihydrodiol metabolites have been previously described. The metabolite distributions produced in incubations of the aza-aromatic compounds with liver microsomes from phenobarbital- and 3-methylcholanthrene-pretreated and untreated rats, and the mutagenicity in the Ames test are described in this paper. The major metabolites of each were the alcohols produced by oxidation of the methyl group on the 8,9,10,11-ring for control and phenobarbital-induced preparations, while with 3-methylcholanthrene-induced preparations both the 7- and 9- (or 10-) monoalcohols were formed. Total monofunctionalized dihydrodiol metabolites, the 5,6- and 3,4-isomers for 7,9-dimethylbenz[c]acridine, and the 3,4-, 5,6- and 8,9-isomers for 7,10-dimethylbenz[c]acridine, constituted approximately 10% of total metabolites. As well, the K-region arene oxide was formed in substantial amounts with both compounds, accompanied in the case of 7,10-dimethylbenz[c]acridine with some 8,9-oxide. When incubations were carried out in the presence of the epoxide hydrase inhibitor 3,3,3-trichloropropane-1,2-oxide, dihydrodiol formation was almost completely inhibited and relative amounts of both phenols and oxides increased. Secondary metabolites were also formed to approximately 10% of the total products. The mutagenicity of synthetic alcohols and isolated purified metabolites was determined in the Salmonella mammalian microsome plate assay (Ames test) with strain TA100. Limited amounts of metabolites isolated precluded extensive testing, but high mutagenicities were noted for all 3,4-dihydrodiol derivatives isolated. These exceeded those of the parent aza-aromatic hydrocarbons. Alcohols were also active but less so than the parent compounds. The activation of these two dimethylbenz[c]acridines to mutagens appears to be through bay-region diolepoxides following patterns seen in other aza-aromatic compounds and the polycyclic aromatic hydrocarbons.

[A convenient and accurate computer program for computing the free Ca2+ concentration in experimental solution]

A computer program for computing the free Ca2+ concentration in the experimental solution containing multiple metals and ligands used for the experimentals of myofibrillar AT-Pase or skinned muscle cell is presented. This program is convenient and accurate.

The stereochemistry of the major rat hepatic microsomal metabolites of 7,9-dimethylbenz[c]acridine and 7,10-dimethylbenz[c]acridine

The monofunctionalized dihydrodiol metabolites of 7,9-dimethylbenz[c]acridine and 7,10-dimethylbenz[c]acridine formed in incubations with rat liver microsomes from untreated and phenobarbital and 3-methylcholanthrene-pretreated rats were isolated by reversed-phase high performance liquid chromatography. The relative amounts of each enantiomer were determined by HPLC of diastereoisomeric esters with (+)-(1R,2S,4S)-endo-1,4,5,6,7,7-hexachlorobicyclo-[2.2.1]hept-5 e ne-2- carboxylic acid (HCA). For the K-region dihydrodiols, absolute configurations were determined from their circular dichroic spectra using the empirical method. The absolute configuration of 3,4-dihydrodiol of 7,9-dimethylbenz[c]acridine was determined by the exciton chirality method from the CD spectrum of its bis-4-(dimethylamino)benzoate ester. For the 8,9-dihydrodiol of 7,10-dimethylbenz[c]acridine the absolute configurations were tentatively assigned by normal-phase HPLC comparison of the (+)-HCA esters with literature data. In every case the R,R-configuration predominated with optical purities > 86% for non-K-region dihydrodiols and 56-68% for the K-region dihydrodiols.

Identification of hepatic metabolites of two highly carcinogenic polycyclic aza-aromatic compounds, 7,9-dimethylbenz[c]acridine and 7,10-dimethylbenz[c]acridine

The hepatic microsomal metabolites of the highly carcinogenic dimethylbenzacridines, 7,9-dimethylbenz[c]acridine (7,9-DMBAC), and 7,10-dimethylbenz[c]acridine (7,10-DMBAC) were obtained with preparations from 3-methylcholanthrene-pretreated rats. Metabolites were separated by reversed-phase HPLC and characterized using UV spectral data and chemical ionization-mass spectrometry after trimethylsilylation and GC. Comparisons with products formed in the presence of the epoxide hydrolase inhibitor, 1,1,1-trichloropropane 2,3-oxide and with those formed from the three synthetic alcohol derivatives of each parent compound, aided the assignment of firm or tentative structures to 16 products from 7,9-DMBAC found in 22 reversed-phase chromatographic peaks, and for 17 products of 7,10-DMBAC found in 19 chromatographic peaks. The more abundant metabolites were derived from oxidation of the methyl groups. Other metabolites were dihydrodiols, epoxides, phenols and secondary metabolites. The 9-methyl group prevented dihydrodiol formation at the 8,9-position from 7,9-DMBAC, and for each carcinogen, the 3,4-dihydrodiol was formed. As well, 3,4-dihydrodiols of methyl oxidized compounds were found.

Failure of intrathymic inoculation of donor-specific splenocytes to prolong cardiac or renal allograft survival in dogs

The intrathymic inoculation (ITI) of donor splenocytes into potential organ transplant recipients has been demonstrated to result in donor-specific unresponsiveness and greatly prolonged survival of subsequent organ allografts in rodents without the need for long-term pharmacological immunosuppressive therapy. We have studied the effect of the ITI of saline (controls) (groups 1 (n = 6) and 3 (n = 6)) or donor splenocytes (groups 2 (n = 10) and 4 (n = 8)) in dogs that received either pharmacological immunosuppression (with cyclosporine and prednisone, +/- azathioprine/cyclophosphamide) (groups 1 and 2) or rabbit anti-dog antithymocyte globulin (groups 3 and 4) at the time of ITI. Kidney or heart allografting (from the donor of the splenocytes) was carried out 16-74 days after ITI; all but four transplants were performed within 16-22 days after ITI. Mean kidney allograft survival was 6, 10, 9, and 9 days, respectively, in groups 1-4. Mean cardiac allograft survival was 7, 14, 8, and 7 days, respectively. There was no statistical difference in allograft survival between those dogs that received ITI of saline and those that received donor splenocytes. These results would suggest that the protocols developed to date using ITI in rodent species may not be successful in dogs.

Bibenzyls from Stemona tuberosa

Three new bibenzyls were isolated from the roots of Stemona tuberosa. Their structures were identified by spectroscopic methods as 3,5-dihydroxy-4-methylbibenzyl, 3,5-dihydroxy-2'-methoxy-4-methylbibenzyl and 3-hydroxy-2',5-dimethoxy-2-methylbibenzyl.

[Detection of human papillomavirus in condyloma acuminata tissues]

We used immunohistochemical technique, in situ hybridization and polymerase chain reaction to detect HPV capsid antigen (HPV-Ag) and HPV-DNA sequences in genital condyloma and pseudocondyloma of vulvae tissues. We also observed the relation between HPV distribution in condylomas and their histological changes.

RESULTS

71.4% of condylomas were positive for HPV-Ag with IMHC, 96.5% of condylomas were positive for HPV6/11 DNA with ISH, and 100% of condylomas were positive for HPV6/11/16/18DNA with PCR. Only 21.4% of pseudocondylomas of vulvae were positive for HPV6/11/16/18DNA with PCR. By observing the distribution of labelled HPV-Ag and HPV-DNA, we found a close relation between HPV proliferative infection and the specific changes of condylomas.

Monomorphic and polymorphic carbohydrate antigens on pig tissues: implications for organ xenotransplantation in the pig-to-human model

The existence of the alpha Gal epitope in 137 pigs belonging to 23 different breeds suggests that this antigen is either monomorphic or occurs at a high incidence in the porcine species. Its histological location at the surface of pig vascular endothelial cells makes it a target for human natural anti-alpha Gal antibodies and complement, which may be responsible for the hyperacute vascular rejection of transplanted pig organs. The precursor carbohydrate chain (N-acetyllactosamine) and NeuAc-substituted epitopes are also exposed at the surface of pig vascular endothelium and were found in all pigs in this study. However, humans also have these two epitopes on vascular endothelium and, consequently, have not made natural antibodies against these carbohydrate antigens. Therefore, these two pig epitopes cannot be the main target of the hyperacute vascular rejection process. Three pig phenotypes-A+ (51%), A:H+ (38%), and A-H- I+ (11%) were identified among 37 Large-white pigs by the presence of polymorphic A, H, and I carbohydrate antigens on the brush border of the surface epithelium of small intestine. These antigens were also present in other exocrine secretions but were not detected on vascular endothelium of the same pigs, suggesting that they are not involved in the hyperacute vascular rejection, although the pig A tissue antigen can induce an immune response in 0 or B blood group recipients. Once the problem of the initial hyperacute vascular rejection directed against the alpha Gal epitope is overcome, typing donor pigs for A, H, and I, as well as for the protein swine leukocyte antigens (SLA) and other pig antigens, may help in elucidating antigens involved in acute or chronic xenograft rejection.

Concurrent generation of nitric oxide and superoxide damages surfactant protein A

The conditions under which nitric oxide (.NO) may modulate or promote lung injury have not been identified. We hypothesized that .NO-induced injury results from peroxynitrite, formed by the reaction of .NO with superoxide. The simultaneous generation of .NO and superoxide by 3-morpholinosydnonimine (SIN-1, 0.1-2 mM) resulted in oxidation of dihydrorhodamine, a marker of peroxynitrite production, and a dose-dependent decrease in the ability of SP-A to enhance lipid aggregation. Western blot analysis of SIN-1 exposed SP-A samples, overlaid with a polyclonal antibody against nitrotyrosine, were consistent with nitration of SP-A tyrosine residues. Superoxide dismutase (100 U/ml), L-cysteine (5 mM), xanthine oxidase (10 mU/ml) and xanthine (500 microM), or urate (100 microM) prevented the SIN-1-induced dihydrorhodamine oxidation and injury to SP-A. .NO alone, generated by S-nitroso-N-acetylpenicillamine plus 100 microM L-cysteine, or superoxide and hydrogen peroxide, generated by pterin and xanthine oxidase in the absence of iron, did not damage SP-A or oxidize dihydrorhodamine. We concluded that peroxynitrite, but not .NO or superoxide and hydrogen peroxide, in concentrations likely to be encountered in vivo, caused nitrotyrosine formation and decreased the ability of SP-A to aggregate lipids.

Evidence that intravenously administered alpha-galactosyl carbohydrates reduce baboon serum cytotoxicity to pig kidney cells (PK15) and transplanted pig hearts

Methods of inhibiting the hyperacute antibody-mediated rejection that occurs when pig organs are transplanted into primates have been investigated using the baboon as a potential recipient. Baboons were treated with different regimens that included combinations of (1) splenectomy, (2) pharmacologic immunosuppression (CsA, cyclophosphamide, corticosteroids +/- methotrexate), and (3) intravenous infusion of oligosaccharides. The cytotoxicity of the serum was then assessed on cultures of pig kidney cells (PK15). Unmodified serum caused approximate 65-100% pig cell destruction. Splenectomy and/or pharmacologic immunosuppression, and infusions of dextran, dextrose or mannitol, did not result in any reduction of cytotoxicity. Infusions of melibiose and/or arabinogalactan, both of which have terminal non-reducing alpha-galactose, however, decreased relative PK15 cell damage significantly in a dose-dependent manner. At high concentrations (< or = 50 g/hr), complete inhibition of cytotoxicity was achieved in 4 of 15 baboons. The extracorporeal immunoadsorption of baboon serum utilizing immunoaffinity columns of melibiose also resulted in a significant reduction (of approximately 80%) in cytotoxic effect. In 1 baboon, melibiose and arabinogalactan infusion delayed vascular rejection of a pig cardiac xenograft from 10 min to about 12 hr, at which time the baboon died from the toxic effects of the carbohydrate infusion. These observations (1) add further support to the role that anti-alpha-galactosyl antibodies play in the hyperacute rejection of pig tissues transplanted into primates, and (2) demonstrate that serum cytotoxicity can be reduced by the intravenous infusion of alpha-galactosyl oligosaccharides or by extracorporeal immunoadsorption using these carbohydrates.

Allelic loss on chromosome-13 can preceed histological-changes in head and neck-cancer

Seventy paired tumor and blood samples from patients with upper aerodigestive tract squamous cell carcinoma (UADT SCC) were tested for allelic loss on chromosome 13. Increased loss of heterozygosity (LOH) was observed at 11 of 13 different highly polymorphic microsatellite 'CA' dinucleotide repeat-containing loci. Increasing percent LOH correlated with lymph node metastasis (N Stage) (p=0.016). LOH was also detected in 10 of 16 (63%) informative samples of histologically normal mucosa adjacent to the tumors. These findings demonstrate that allelic loss on chromosome 13 is a frequent event in UADT SCC. Furthermore, these genetic alterations can be detected prior to histological changes in normal mucosa adjacent to these tumors.

Clonality of head and neck-carcinoma and adjacent mucosa

Upper aerodigestive tract squamous cell carcinoma (UADT SCC) is associated with exposure to tobacco and ethanol and there is a high incidence of multifocal dysplasia, synchronous/metachronous lesions and local recurrence. These observations led to a 'field cancerization' hypothesis which proposes that the entire expanse of carcinogen-exposed mucosa is predisposed to neoplasia. This hypothesis implies that UADT SCC arises from multiple sites and is therefore polyclonal. To test this hypothesis, eight paired tumor and blood samples and 4 specimens of adjacent normal mucosa were tested for clonality by molecular X chromosome inactivation analysis. While tumor specimens were clonal, normal mucosa and blood were polyclonal. These findings demonstrate that UADT SCC is a clonal neoplasm that arises from polyclonal mucosa and supports an alternative interpretation of the 'field cancerization' theory which states that multiple sites are at risk and each neoplasm arising from these different sites is monoclonal.

Cardiac allotransplantation across the ABO-blood group barrier by the neutralization of preformed antibodies: the baboon as a model for the human

The baboon, like the human, expresses A and/or B blood group antigens on its tissues. Anti-A and anti-B antibodies are directed against these antigens, the epitopes of which are carbohydrate structures. Portions of these carbohydrates have been synthesized (trisaccharides A and B, respectively). When infused intravenously, the synthetic trisaccharides form a complex with the specific antibodies and neutralize their activity preventing them from binding to the antigen targets on a transplanted organ. In nonimmunosuppressed, hyperimmunized baboons, the continuous intravenous infusion of the specific trisaccharide alone (for 6 days) inhibited rejection of ABO-incompatible cardiac allografts, extending survival from a mean of 19 min (n = 3) to 8 days (n = 2), at which time the grafts failed from cellular (not vascular) rejection. The combination of long-term pharmacologic immunosuppression plus trisaccharide infusion (for periods of 8 to 19 days) extended survival to a mean of > 28 days (n = 4) with one heart functioning > 52 days. Accommodation clearly occurred in three of the four cases. This form of therapy may permit cadaveric organ allotransplantation across the ABO blood-group barrier in the human.

Protection of pig kidney (PK15) cells from the cytotoxic effect of anti-pig antibodies by alpha-galactosyl oligosaccharides

Anti-pig antibodies in human and baboon serum are believed to be directed against alpha-galactosyl (alpha Gal) epitopes expressed on various pig cells, including vascular endothelia. We have investigated the effect of human sera on the PK15 pig kidney cell line, which abundantly expresses alpha Gal epitopes. To quantitate cell viability, we have used a staining method that differentiates live cells from dead ones. Various carbohydrates (n = 28) were added individually to serum at concentrations of 0.125-50 mg/ml. Unmodified serum caused approximate 100% PK15 cell death within 60 min. Carbohydrates that were not alpha Gal based did not significantly protect PK15 cells. Of the alpha Gal-based carbohydrates, only B disaccharide protected PK15 cells from both human and baboon serum (76% and 93% protection, respectively, at 1 mg/ml). Three alpha Gal oligosaccharides provided approximately 80-90% protection against both human and baboon sera at a concentration of 10 mg/ml. Three other closely related structures protected only against baboon serum (> 80%) at high concentration (50 mg/ml), suggesting a difference in anti-pig antibody affinity between baboon and man. Specific anti-alpha Gal antibody-depleted serum caused < 10% pig cell death, whereas the antibodies eluted from the alpha Gal columns caused > 70% pig cell death. In conclusion, this study provides further evidence that (1) alpha Gal structures are the targets for human and baboon anti-pig antibodies, and (2) there may be a therapeutic role for the infusion of specific alpha Gal carbohydrates, or for antibody removal using alpha Gal immunoaffinity columns, in order to prevent hyperacute rejection of pig organs in man.

The pig as a potential organ donor for man. A study of potentially transferable disease from donor pig to recipient man

Ten pigs, reared in an unmodified laboratory animal house environment, have been investigated to ascertain the incidence of diseases or disorders, including infection, neoplasia, or metabolic abnormalities, that might preclude the transplantation of major organs from the pig to man. Noninvasive studies were performed in the second month of life (study 1) and repeated after an interval that varied between 3 and 5 1/2 months (study 2). Necropsy was then performed as a means of assessing the accuracy of the 2 screening examinations. A total of 150 tests were performed on each pig. At both studies the feces contained cysts and/or trophozoites of several parasites, all of which were considered commensals. No other organisms potentially infective for man were identified either at study or at necropsy. Neither congenital anomalies nor malignant neoplasia was found at necropsy. However, in 2 pigs a vasculitis of uncertain etiology was present in the kidneys on microscopic examination, and in one of these the same condition affected the heart. This pathology was suspected neither from the screening examinations nor from the macroscopic appearance of these organs. Biopsy and microscopic examination would therefore appear to be essential before any organ is transplanted into a human.

Carbohydrate antigens of pig tissues reacting with human natural antibodies as potential targets for hyperacute vascular rejection in pig-to-man organ xenotransplantation

Pig tissues were screened by immunofluorescence with lectins, mAb, and human natural antibodies for the presence of carbohydrate antigens, which may be potential targets for hyperacute vascular rejection in pig to man xenotransplantation. The unfucosylated monomorph linear B-antigen was found at the surface of all porcine vascular endothelial cells. This pig linear-B antigen reacts strongly with the anti-alpha Gal isolectin B4 from Griffonia simplicifolia 1 and with human natural anti-alpha Gal antibodies specifically purified by affinity chromatography on synthetic oligosaccharides containing the terminal nonreducing alpha Gal1-->3 beta Gal-R disaccharide. This antigenic activity is destroyed by treatment of pig tissues with alpha-galactosidase. The localization of this linear-B epitope on vascular endothelium and its reactivity with natural human anti-alpha Gal antibodies suggest that it may play a major role in the hyperacute vascular rejection of pig to man organ xenografts. The lectin from Maackia amurensis reacting with alpha NeuAc2-->3 beta Gal1-->4GlcNAc/Glc was also positive on pig vascular endothelium, but we do not know yet whether there are human natural antibodies reacting with the carbohydrate recognized by this lectin. Epithelial cells of pig renal proximal convoluted tubules, respiratory epithelium, pancreatic ducts, and epidermis express the linear-B antigen, but they are less likely to trigger a hyperacute vascular rejection because they are not directly exposed to the blood. The genetically defined pig A+/A- system controls the expression of A and H antigens in pig epithelial cells from renal distal and collecting tubules, biliary ducts, pancreatic ducts, large bronchi, and digestive mucosa. The pig A antigen may trigger an immune response in human O or B recipients if they are transplanted with organs from A+ pigs, but the pig A antigen is probably not involved in the hyperacute vascular rejection of a xenograft because it is not expressed on vascular endothelium.

Binding and specificity of major immunoglobulin classes of preformed human anti-pig heart antibodies

Preformed human anti-pig antibodies isolated from perfused pig hearts were used to analyze the binding of various immunoglobulin classes to cultured pig kidney cells. All anti-pig immunoglobulins (i.e., IgG, IgA, and IgM) were localized on the cell surface by the use of an indirect immunofluorescence technique. Anti-pig immunoglobulins also competed for the pig cell surface epitopes with Griffonia simplicifolia lectin (GS-I-B4), which is specific for alpha-galactosyl residues. This study provides further evidence that preformed human antibodies recognizing alpha-galactosyl-containing epitopes (anti-gal antibodies) could be an important factor in hyperacute rejection of pig organs.

Specific intravenous carbohydrate therapy. A new concept in inhibiting antibody-mediated rejection--experience with ABO-incompatible cardiac allografting in the baboon

Heterotopic allografting of ABO-incompatible donor hearts in recipient baboons "hyperimmunized" against the incompatible A or B antigen (n = 3) was followed by hyperacute antibody-mediated vascular rejection within a mean of 19 min. The A and B epitopes against which these antibodies are directed are carbohydrates that can be synthesized. The continuous i.v. infusion of the specific synthetic A or B trisaccharide, beginning immediately pre-transplant and continued posttransplant for several days, prolonged allograft survival to a mean of 8 days (n = 2) and prevented antibody-mediated rejection, graft failure resulting from acute cellular rejection. The addition of triple pharmacologic immunosuppressive therapy (n = 4) resulted in prolongation of graft survival to a mean of > 28 days, with one heart still beating at 52 days; all grafts showed features of cellular rejection. "Accommodation" would appear to have developed in several baboons as graft function continued for periods of up to 39 days after discontinuation of carbohydrate therapy. Specific i.v. carbohydrate therapy should allow organ allografting to be performed across the ABO blood group barrier in humans. Furthermore, if the carbohydrate epitopes on the organs of discordant animals (e.g., the pig) against which human xenoreactive antibodies are directed can be confirmed, then this form of therapy might allow successful discordant organ xenotransplantation in man.

Identification of alpha-galactosyl and other carbohydrate epitopes that are bound by human anti-pig antibodies: relevance to discordant xenografting in man

Human anti-pig antibodies were obtained by perfusing pig hearts (n = 4) and kidneys (n = 8) with human AB or O plasma followed by elution with 3 M NaSCN. The antibodies were screened against a panel of 132 synthetic carbohydrates conjugated to bovine serum albumin using an enzyme-linked immunoassay. An anti-immunoglobulin antibody was also used to detect immunoglobulin deposits on pig tissues. Four carbohydrate molecules with a terminal alpha-galactose residue bound all but one of the human anti-pig kidney antibodies and most of the anti-pig heart antibodies. These were: (i) alpha Gal(1-->3)beta Gal(1-->4)beta GlcNac (linear B type 2); (ii) alpha Gal(1-->3)beta Gal(1-->4)beta Glc (linear B type 6); (iii) alpha Gal(1-->3)beta Gal(B disaccharide); and (iv) alpha Gal(alpha-D-galactose). Immunoglobulin deposition was documented post-plasma perfusion in all pig hearts and particularly strongly in all pig kidneys. These results suggest that human anti-pig antibodies are mainly directed against alpha-galactosyl structures. Extracorporeal immunoadsorption of human plasma through columns of the specific synthetic carbohydrate(s) might lead to depletion of anti-pig antibodies and allow discordant xenografting in man. Alternatively, the infusion of the specific carbohydrate(s) for a period of several days might result in neutralization of the anti-pig antibodies and allow accommodation to take place.

Analysis of WT1 in granulosa cell and other sex cord-stromal tumors

The molecular genetic events involved in the etiology of granulosa cell, Sertoli cell, and Leydig cell tumors are unknown. The expression of the Wilms' tumor suppressor gene WT1 in granulosa and Sertoli cells prompted us to analyze this gene for mutations in 11 granulosa cell tumors, three Leydig cell tumors, and one Sertoli/Leydig cell tumor. Although most of these tumors express WT1 mRNA, none harbors a WT1 mutation in the zinc finger domains where > 90% of WT1 mutations in sporadic Wilms' tumors have been found. In addition we were able to exclude tumor-specific loss of heterozygosity in 13 of 15 cases. Taken together these results suggest that the WT1 gene is unlikely to play an important role in the development of sex cord-stromal tumors.

A suggested technique for "orthotopic" heart transplantation in a patient with situs inversus

We describe a technique for "orthotopic" heart transplantation in a patient with situs inversus. The left atrial, aortic, and pulmonary artery anastomoses were performed directly, in the usual manner. The recipient's right atrium was converted into a tunnel, and the donor's right atrium was left intact. Anastomoses were therefore required between the 2 inferior venae cavae (by direct end-to-end anastomosis) and the 2 superior venae cavae (necessitating the insertion of a Dacron-graft). We suggest that even simpler techniques, perhaps not requiring the use of an artificial vascular prosthesis, are possible.

Prevention of loss of vertebral bone density in heart transplant patients

Seventy-six patients (63 men, 13 women) have been followed up by vertebral bone density (VBD) studies from 3 to 36 months. VBD was measured by single-energy computerized tomographic scan. Before transplantation, VBD was found to be lower than in age-matched controls (less than 40 years of age [group 1], 96% of controls: 40 through 49 years of age [group 2], 77%; 50 to 60 years of age [group 3], 87%; more than 60 years of age [group 4], 76%). After transplantation, despite oral calcium supplements, VBD fell further in all but two patients (97%), which was almost certainly related to maintenance steroid and cyclosporine therapy, and was most marked in the older groups (group 2, 67% compared with age-matched controls at 6 months; group 3, 60%; group 4, 50%). Intensive therapy with synthetic salmon calcitonin (in 29 of 76 patients [38%]), testosterone (in 33 of 63 men [52%]), or estrogen (in 12 of 13 women [92%]) limited, but did not totally prevent, further loss in VBD; in patients who had shown an approximate 45% loss of VBD from pretransplantation levels, further loss was reduced to between 4% and 10%. Five patients increased bone density after calcitonin therapy. Despite significantly reduced VBD in several older patients, minor vertebral bone compression developed in only one patient. We recommend that all patients undergoing heart transplantation, particularly those over the age of 50 years, should be followed by VBD studies, and therapy should be administered to prevent VBD loss.

Enzyme-linked immunosorbent assay for the detection of substances that carry blood group A specificity

An enzyme-linked immunosorbent assay (ELISA) was developed to estimate the amount of material carrying blood group A activity in biologic samples. A soluble synthetic form of the A antigenic determinant (A trisaccharide, ATS) conjugated to peroxidase competes with the blood group A substance present in a biologic sample for anti-A attached to a solid phase by a second antibody coating the plastic micro-wells. A reference curve is constructed by using known quantities of ATS to compete with a fixed amount of ATS-peroxidase conjugate. The A substance activity in a sample is obtained by extrapolating the degree of inhibition of the binding of the ATS-peroxidase conjugate to an equivalent amount of ATS in the reference curve. The assay is reproducible, specific, and sensitive. It has been used in pharmacologic studies to estimate the concentration of ATS in the blood and urine of rats, rabbits, and baboons and in a study with human samples, testing the potential clinical use of ATS to neutralize anti-A when therapeutically indicated. It is also useful for the detection of ABO natural products in secretions, thus allowing the accurate classification of secretor and nonsecretor individuals.

[Studies on the antitumor antibiotic aclacinomycin A]

During the course of screening for new antitumor antibiotics, a new anthracycline antibiotic--aclacinomycin A was separated from the broth and mycelium of Streptomyces AC-57. The strain AC-57 was isolated from the soil collected in the Shanghai suburbs. According to its culture and physiological characteristics the producer was identified as Str. galilaeus AC-57. The broth and mycelium were extracted and treated with solvents as usual way. The aclacinomycin A was separated by silica-gel column chromatography eluted with chrolo-form-methanol. Aclacinomycin A, its aglycone and sugar components were identified by comparison of their physico-chemical and spectral data (MS, UV, IR, 1H-NMR, and 13C-NMR) with authentic compound, purified from the market sample.

[Clinical therapeutic effect of xifukang in 53 patients with silicosis]

Xifukang is a compound preparation of Chinese herbs consisting of Hanbane grugs mainly. Since 1987, the significant efficiency have been obtained in treatment of 53 patients suffering from silicosis by self-control study. The results indicated that the clinical manifestations including dyspnea, cough, sputum production, chest pain, weakness, etc. were markedly improved (P less than 0.01) and measurements of pulmonary function (FVC, FEV and MVV) significant enhanced (P less than 0.01). After treatment 20 cases roentgenogram exam showed that the lung's clarity and the limited emphysema were improved, the silicolic nodule and mass-mergence opacity of 3 cases lessened in some degree. By discussing the effect of Xifukang which might lower the collagen protein content of experimental silicosis of Wistar rats and improve pathomorphous. The authors concluded that the therapeutic mechanism of Xifukang could be the actions of this remedy on promoting blood circulation to eliminate blood stasis dredging microcirculation, increasing ventilation/perfusion (VA/Q), protecting dust-cells, resisting fibrosis, regulating immune function, enhancing lung clearance, postponing and preventing development of silicosis.

[Experimental endolymphatic hydrops and its related morphological and functional changes in guinea pigs]

The endolymphatic hydrops was induced successfully in 13 guinea pigs by blocking the endolymphatic duct and sac, and the morphological and functional alterations (especially on semicircular canal function) after hydrops were studied by means of ENG, EcochG and serial section techniques. Hydrops in the cochlear duct was evident in the apical and/or near apical turns, especially in earlier stages. Dilation of the saccule was seen in all samples, but was barely noticeable in the utricle and semicircular canal's endolymphatic space. Degeneration in the corti's apparatus, stria vasculi and spiral ganglion occurred late. No evident changes of the sensory components in the saccule, utricle and semicircular canals were seen under the light microscope. The hearing loss in earlier stages of hydrops was evident at lower frequencies: later stages showed effects at all frequencies. The cochlear recruitment and fluctuation phenomena were observed in a few of the operated animals. The value of -SP/CAP in a few animals was significantly after operation. The functional changes of semicircular canals were demonstrated by the semicircular paralysis (CP), directional preponderance (DP), vestibular recruitment (VR) and elevated threshold of nystagmus to angular acceleration stimuli. There was no significant correlation between the degrees of hearing loss and impaired semicircular function. The criteria of ENG elicited by the quantitative angular acceleration stimuli for evaluating the semicircular canal function in guinea pigs is proposed for the first time in our experiment.

Phenotypic analysis of infiltrating cells in human myocarditis. An immunohistochemical study in paraffin-embedded tissue

To define the cellular subpopulations that infiltrate the heart in human myocarditis, formaldehyde-fixed, paraffin-embedded sections from 18 hearts with histologically proved myocarditis were examined immunohistochemically. Disease was classified on routine stains as follows: mixed mononuclear cell (7 cases), granulomatous (3), giant cell (1), rheumatic (2), and fungal (5) myocarditis, respectively. On immunohistochemical examination, T-lymphocyte and macrophage predominance was found in nearly every case, except in fungal myocarditis, in which polymorphonuclear leukocytes and macrophages prevailed. In contrast, B lymphocytes and natural killer cells were conspicuously absent, regardless of histologic classification. Giant cells in giant cell myocarditis and in the Aschoff lesions of rheumatic carditis expressed macrophage, but not myocyte, antigens, suggesting derivation along macrophage lineage. Immunohistochemical data obtainable in paraffin-embedded tissues supplement the study of myocarditis, providing information potentially relevant to immunopathogenesis, natural history, and therapy.

Photodecomposition of nitrocellulose: threshold power density and the effect of temperature

This Letter reports photolysis of nitrocellulose by cw UV light at low power density.