Antibody penetration of viable human cells. I. Increased penetration of human lymphocytes by anti-RNP IgG

Antibody penetration of viable cells and interaction with intracellular antigens may have major consequences for immunopathological processes in connective tissue diseases. We have reported previously that antibody can penetrate viable human lymphocytes. To assess further the role of antinuclear antibodies in this process, peripheral blood lymphocytes (PBMC) were incubated with FITC-conjugated IgG fractions from sera containing anti-RNP (anti-RNP IgG), Ro(SS-A), La(SS-B) and dsDNA antibodies and control sera for 24 h. Using crystal violet to quench cell surface staining, intracellular fluorescence of viable lymphocytes was quantified on the flow cytometer. It was noted that anti-RNP IgG entered 46.4 +/- 7.2% of lymphocytes which was significantly higher than anti-Ro(SS-A) (29.9 +/- 4.1%, P less than 0.05), La(SS-B) (22.0 +/- 7.5%, P less than 0.01) IgG and control IgG (28.8 +/- 2.1%, P less than 0.05) and not statistically different from anti-dsDNA IgG (32.6 +/- 14.3%). Inhibition experiments showed that the increased number of cells penetrated by anti-RNP IgG was a specific process. Time-course studies showed that anti-RNP IgG entry into cells was different from pooled control IgG. With anti-RNP IgG, positive-staining lymphocytes gradually increased in number from 12 to 24 h incubation, whilst with pooled control IgG, the peak was reached within 5 min. Dual staining experiments suggested that whereas both anti-RNP IgG and pooled control IgG entered B and NK cells, anti-RNP IgG also entered T cells. Using IgG F(ab')2 and Fc fragments from either anti-RNP IgG or pooled control IgG to compete with their FITC-conjugated counterparts indicated that the entry of anti-RNP IgG into-viable cells appeared to involve both F(ab')2 and Fc fragments, and pooled control IgG depended exclusively on the Fc portion of IgG. Further investigation by incubating anti-RNP IgG with 35S-methionine-labelled monocyte-depleted PBMC (MD-PBMC) suggested that anti-RNP IgG might react with the corresponding antigens either on the cell surface or within the cytoplasm.

Drug-induced DNA repair: X-ray structure of a DNA-ditercalinium complex

Ditercalinium is a synthetic anticancer drug that binds to DNA by bis-intercalation and activates DNA repair processes. In prokaryotes, noncovalent DNA-ditercalinium complexes are incorrectly recognized by the uvrABC repair system as covalent lesions on DNA. In eukaryotes, mitochondrial DNA is degraded by excess and futile DNA repair. Using x-ray crystallography, we have determined, to 1.7 A resolution, the three-dimensional structure of a complex of ditercalinium bound to the double-stranded DNA fragment [d(CGCG)]2. The DNA in the complex with ditercalinium is kinked (by 15 degrees) and severely unwound (by 36 degrees) with exceptionally wide major and minor grooves. Recognition of the DNA-ditercalinium complex by uvrABC in prokaryotes, and by mitochondrial DNA repair systems in eukaryotes, might be related to drug-induced distortion of the DNA helix.

[Diagnostic value of 99mTc-PMT delayed hepatobiliary imaging in small hepatocellular carcinoma--an analysis of 62 cases]

99mTc-PMT delayed hepatobiliary imaging was performed preoperatively in 62 patients with small hepatocellular carcinoma. All patients received operation and had pathological proof. All these tumors were smaller than 5 cm in size. Liver scan was done 5 min, 2 and 5 hr after administration of radiopharmaceutics. The sensitivity was 33.3% (2/6), 41.2% (7/17), 60.0% (9/15) and 54.2% (13/24) in tumors with sizes of less than or equal to 2 cm, 2-3 cm, 3-4 cm and 4-5 cm groups, respectively. The positive rates in the first two groups were lower than in the last two groups but much higher than those by conventional imaging. The total positive rate was 50.0%. The difference was not significant in comparison with the group of tumor size greater than 5 cm. The smallest mass detectable was only 1.2 cm in diameter. The uptake of radiopharmaceutic was not related to serum AFP level and hepatic cirrhosis (P greater than 0.05). These results show that 99mTc-PMT delayed hepatobiliary imaging may be useful in the diagnosis, particularly in the pathognomonic diagnosis, of small hepatocellular carcinoma.

[Effect of Salvia miltiorrhiza on the left ventricular diastolic function in coronary artery stenosis]

In 24 open-chest mongrel dogs, coronary artery critical stenosis were produced by a micrometer constriction on left circumflex coronary artery. It was reduction about 87% in lumen area. CBF, -Vce, -dp/dt max were decreased, T was increased (P less than 0.01). 15 minutes after stenosis, the Salvia miltiorrhiza injection was injected into left atrium. CBF, -dp/dt max, -Vce were increased and T was decreased after the injection of Salvia miltiorrhiza. Moreover, the change of CBF was the earliest. The results proved that the Salvia miltiorrhiza could improve the left ventricular diastolic function in coronary artery stenosis.

Chlorobutanol, a preservative of desmopressin, inhibits human platelet aggregation and release in vitro

Therapeutic preparations of desmopressin for parenteral use contain the preservative chlorobutanol (5 mg/ml). We show here that chlorobutanol is a potent inhibitor of platelet aggregation and release. It exhibited a significant inhibitory activity toward several aggregation inducers in a concentration- and time-dependent manner. Thromboxane B2 formation, ATP release, and elevation of cytosolic free calcium caused by collagen, ADP, epinephrine, arachidonic acid and thrombin respectively were markedly inhibited by chlorobutanol. Chlorobutanol had no effect on elastase-treated platelets and its antiplatelet effect could be reversed. It is concluded that the antiplatelet effect of chlorobutanol is mainly due to its inhibition on the arachidonic acid pathway but it is unlikely to have a nonspecific toxic effect. This antiplatelet effect of chlorobutanol suggests that desmopressin, when administered for improving hemostasis, should not contain chlorobutanol as a preservative.

[The clinical significance of antibodies to SM, RNP and SSR polypeptides detected by immunoblotting technique]

Using immunoblotting technique (IBT) antibodies to Sm, RNP and SSB polypeptides we detected in 173 patients with different rheumatic diseases. It was found that antibodies to Sm polypeptides with molecular weights of 28K(B) and 13.5K(D) could be detected almost only in SLE (34.0% and 30.0% respectively). The positive rates of anti-28K and anti-13.5K polypeptides in SLE detected by IBT were significantly higher than those of anti-Sm by counterimmunoelectrophoresis (12.0%) (P less than 0.05). The antibodies to SSB polypeptides with molecular weights of 48K and 43.41K could be detected mainly in Sjogren's syndrome (70.0% and 65.0% respectively) and the antibodies to RNP polypeptides with molecular weights of 68K, 32K(A) and 29K (B') mainly in MCTD (82.6% 100% and 34.8% respectively) (P less than 0.001). It was reported by Pettersson that anti-68K polypeptide had high specificity for the diagnosis of MCTD. But our data showed that the anti-68K polypeptide could also be detected in SLE(26.0%) and PSS(15.0%) and was not so specific for MCTD.

Transforming activity of E5a protein of human papillomavirus type 6 in NIH 3T3 and C127 cells

Human papillomavirus type 6 (HPV-6) is the etiologic agent of genital warts and recurrent respiratory papillomatosis. We are investigating the mechanism by which this virus stimulates cell proliferation during infection. In this paper, we report that the E5a gene of HPV-6c, an independent isolate of HPV-11, is capable of transforming NIH 3T3 cells. The E5a open reading frame (ORF) was expressed under the control of the mouse metallothionein promoter in the expression vector pMt.neo.1, which also contains the gene for G418 resistance. Transfected cells were selected for G418 resistance and analyzed for a transformed phenotype. The transformed NIH 3T3 cells overgrew a confluent monolayer, had an accelerated generation time, and were anchorage independent. In contrast, E5a did not induce foci in C127 cells, but C127 cells expressing E5a did form small colonies in suspension. The presence of the 12-kilodalton E5a gene product in the transformed NIH 3T3 cells was shown by immunoprecipitation and was localized predominantly to nuclei by an immunoperoxidase assay. A mutation in the E5a ORF was engineered to terminate translation. This mutant was defective for transformation, demonstrating that translation of the E5a ORF is required for biological activity. This is the first demonstration of a transforming oncogene in HPV-6, and the differential activity of E5a in these two cell lines should facilitate future investigations on the mechanism of transformation.

Macromolecular synthesis in the isolated rat myointima in vitro

The myointima, which forms within the lumen of the carotid artery of the rat in response to the removal of the endothelium by a balloon catheter, could be extruded from the vessel as early as 6 days after denudation. The mean concentration of DNA in the isolated myointima increased as the myointima grew in vivo until 12 to 14 days after denudation, when the arterial lumen was filled with the myointima; thereafter the mean concentration of DNA declined. DNA and protein synthesis, incorporation of 3H-glucosamine and 3H-fucose into macromolecules, occurred in the myointima during incubation in vitro in the absence of fetal bovine serum, and with the exception of 3H-glucosamine, failed to be stimulated by it. These data indicate that the cells of the intact myointima do not require exogenous macromolecular growth factors for the synthesis of macromolecules in vitro.

Correlations of blood lipids and lipoproteins with coronary artery disease documented by angiography

A study of the relationships between serum TC, TG and HDL.C and selective coronary arteriography was carried out on 117 patients who were divided into groups according to the extent of artery stenosis. Normal control group consisted of 153 healthy subjects. There were no statistical differences in TC, TG, HDL.C, LDL.C, TC/HDL.C, LDL.C/HDL.C and TC-HDL.C/HDL.C between normal control group and the group with normal coronary arteriogram. LDL.C, TC/HDL.C, LDL.C/HDL.C, TC HDL.C/HDL.C rose and HDL.C decreased as the degree of coronary artery stenosis and the extent of stenosis increased, besides the medium and severe stenosis group. Analyses based on the correlation coefficients indicate that 3 compound indexes (TC-HDL.C/HDL.C, TC-HDL.C, LDL.C/HDL.C) are better in assessing CAD than single index such as LDL.C, HDL.C and TC. The results of our study showed that the 3 compound indexes might be regarded as important risk factors for CAD.

[Effect of nicorandil on coronary circulation in ischemic region]

To clarify the role of nicorandil (Nic) in relieving myocardial ischemia, the effects of Nic in canine models of coronary arterial stenosis were studied. During stenosis of the anterior descending coronary artery by an external micrometer constrictor, intracoronary infusion of Nic 1, 5 micrograms/(kg.min) increased coronary blood flow and decreased distal coronary pressure, total coronary arterial resistance and small coronary arterial resistance; but did not affect mean aortic pressure, heart rate and large coronary arterial resistance. Whole blood viscosity, plasma viscosity and hematocrit in coronary vein after intracoronary infusion of Nic were reduced. The results intravenous infusion of Nic were similar to those of intracoronary infusion. These results indicate that Nic is capable of increasing coronary blood flow, alleviating myocardial ischemia due to direct dilatation of coronary artery and reduction of blood viscosity in ischemic region.

Effect of insulin pump therapy on blood pressure and the renin-angiotensin system of diabetic rats

Insulin therapy, administered by continuous subcutaneous infusion with osmotic pumps over a 28 day period at doses of 2.5 and 5.0 units/day, resulted in a statistically significant increase in body weight of diabetic rats. The concentration of blood glucose was reduced by 68% to 109 mg/dl blood sugar by the higher dose of insulin and only partial control of diabetes was achieved by the lower dose (185 mg/dl blood sugar, -39%). Blood pressure was normalized by both doses of insulin. Elevated serum angiotensin converting enzyme activity and plasma renin activity, expressed as generated angiotensin I, were unaffected by the lower dose of insulin, but were reduced by 26% and 40%, respectively at the higher dose. These data suggest that elevated serum ACE and plasma renin activity, commonly found in the streptozotocin-diabetic rat, may not be primarily responsible for hypertension in this model.

Daurisoline derivatives inhibit the ability of calmodulin to stimulate cyclic nucleotide phosphodiesterase activity

Daurisoline alkaloid derivatives were found to be potent calmodulin (CaM) antagonists. The ability of daurisoline derivatives to attenuate the stimulatory effect on calmodulin activated cyclic nucleotides phosphodiesterase (CaM-PDE) was studied. These compounds did not inhibit the basal activity of this enzyme. The hydrophobicity of these compounds was related to their inhibitory potency. It is suggested that such drugs bind directly to calmodulin in a Ca2(+)-dependent fashion, as indicated by their ability to change calmodulin fluorescence.

Detection by antibody probes of human papillomavirus type 6 E5 proteins in respiratory papillomata

We have demonstrated the expression of proteins arising from the E5a and E5b open reading frames (ORFs) of human papillomavirus type 6c (HPV-6c) in respiratory tract papillomata. Recombinant plasmids were constructed to express the ORFs in the bacterial vectors pATH and pRIT2T. Fusion proteins were purified and injected into rabbits to produce polyclonal antibodies. Characterized antibodies generated against these fusion proteins were used in immunoperoxidase assays to identify the presence and distribution of HPV-6 E5 proteins in biopsy specimens of respiratory tract papillomata. The results showed that the E5a and E5b proteins were distributed throughout the thickness of the epithelium in the papillomata but not in the basal layer. The proteins were found in nuclei and in the cytoplasm of koilocytotic cells. Positive reactivity with a similar distribution in the epithelium and subcellular location was obtained in papillomata induced by other HPV-6 subtypes. This cross-reactivity was not unexpected, since nucleotide and amino acid (aa) sequence comparisons between HPV-6c and -6e demonstrated 79% sequence identity with 15 aa substitutions in the 91 aa of E5a. The E5b ORF of HPV-6c has the potential to encode a protein of 74 aa that differed at 28 positions compared with the 72 aa of HPV-6e.

[Effects of experimental coronary artery stenosis on platelet function]

In mild stenosis, coronary blood flow (CBF) was unchanged, thromboxane (TX) B2/6-ketoprostaglandin (PG) F1a ratio rose with no change in PAgT. In critical stenosis, CBF was slightly decreased, PAgT, TXB2 and TXB2/PGF1a ratio rose with cyclical reduction in CBF. In severe stenosis, CBF was markedly decreased; PAgT, TXB2 and TXB2/6-keto-PGF1a ratio rose and 6-keto-PGF1a decreased with cyclical blood flow reduction. Histopathologic examination confirmed the presence of damaged endothelial cell with coronary thrombosis and platelet/fibrin microemboli in critical and severe stenosis. It is concluded that coronary artery stenosis leads to a damage of endothelial cell, which causes an abnormality in platelet function and coronary thrombosis.

[The consumption of fibronectin content in coronary artery stenosis in dogs]

Changes in plasma fibronectin (Fn) content of the coronary sinus were observed in coronary artery stenosis of dogs. The results showed that coronary artery stenosis produced an acute inflammatory response and decreased Fn when coronary artery stenosis was more than 75%, which was associated with an increase in platelet aggregation and activation. Histopathologic examination confirmed the presence of damaged endothelial cell and capillary and showed the adhesion of leukocyte and platelet also. The results suggest that injured coronary artery may impair protective function in coronary circulation.

Human lymphocyte reaction to freeze-dried allograft and xenograft ligamentous tissue

Decisions made before reconstruction of the ACL include patient selection, choice of operative procedure, and selection of proper reconstructive material. Research in the use of allograft material for reconstructive grafts is of great interest for many reasons, including the advantage of not violating the patient's normal anatomy for donor tissue. A group of eight patients who received arthroscopically inserted freeze-dried bone-patellar tendon-bone allograft tissue for ACL reconstruction were selected for a prospective study. These patients were matched against a group of four autograft controls. Immunologically, the lymphocyte blast transformation test was used to evaluate the host reaction to implanted donor graft. Lymphocytes drawn from each patient were tested for their reaction against a panel of human allograft tendon and goat xenograft tendon homogenates. A stimulation index of greater than 3 was considered a positive reaction. It was hypothesized that a consistent lack of antigenicity would be observed with allograft extracts and that an antigenic reaction would be observed with the xenograft extracts. Six patients (75%) showed an immunologic reaction to the goat xenograft, and four patients (50%) showed an immunologic reaction to at least one human allograft test cell after allograft insertion. One patient had such an intense clinical immunologic response that she required removal of the allograft. All four of the autograft controls had a nonimmunogenic response to testing, as had been expected.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural analysis of human papillomavirus type 6c isolates from condyloma acuminatum and juvenile-onset and adult-onset laryngeal papillomata

The human papillomavirus type 6c (HPV-6c) genome was molecularly cloned from biopsy specimens of a juvenile-onset and an adult-onset respiratory-tract papillomata and a condyloma acuminatum of the cervix. To determine if the genital-tract isolate and respiratory-tract isolates contain divergent sequences that may account for a difference in tissue trophism or for a difference in the age of onset of the disease, fine-structure mapping, heteroduplex analysis by electron microscopy, and nucleotide sequencing were used to examine the sequence relationship among these HPV-6c isolates. No differences were found in the digestion patterns with 23 restriction enzymes. Heteroduplex analysis among the three genomes demonstrated that they were colinear without apparent deletions or rearrangements and had greater than 90% sequence identity. In heteroduplex analyses with a different subtype (HPV-6e) that was molecularly cloned from a genital wart, the genomes were colinear with greater than 90% sequence identity over 90% of their length. The most divergent region had 75-80% sequence identity and was localized to the part of the genome containing the E5a and E5b open reading frames (ORFs). Comparison of the sequence of 1430 nucleotides in this region for two of the HPV-6c isolates did not identify any differences between them. Comparison with the published sequences of HPV-6b identified deletions/insertions and base changes with approximately 75% sequence identity, and comparison with HPV-11 identified only six base changes. Conservation of sequences in the E4-E5 region and similarity in the restriction enzyme maps demonstrated that HPV-6c and HPV-11 are independent isolates of the same HPV-6 subtype.

Identification of the types of adenovirus isolates with monoclonal antibodies

The types of 59 isolates of adenovirus (Adv) which were isolated between winter, 1984 and spring, 1986 were identified by type-specific monoclonal antibodies (McAb) against Adv types 3 and 7. The results showed that the method could not only identify the types of Adv, but also discover the changes of their subtypes with time. The tedious neutralization test can be replaced by this simple method.

[The relationship between coronary artery stenosis and myocardial metabolism of oxygen demand in dogs]

In open chest dogs, a micrometer constrictor was used to produce three different coronary artery stenosis (AS) on left circumflex coronary artery, and hemodynamics, blood gas and coronary sinus pH, lactate were then measured. In mild coronary AS, resting coronary artery flow (CBF) did not decrease; but lactate increased. In critical coronary AS, CBF slightly decreased, MVO2 decreased and lactate increased. There was a decrease in CBF, O2 supply/consumption ratio, coronary sinus pH and an increase in oxygen extraction and lactate with severe coronary AS. The percent area stenosis (%AS) was highly correlated with O2 supply (r = -0.92), poorly correlated with MVO2 (r = -0.58) when it was higher than 75%.

Recording of the electrocardiogram from the sinus node and direct measurement of the sinuatrial conduction time in children

Using a simple technique, the electrocardiogram from the sinus node, which had been previously recorded in adults, was for the first time derived successfully in 27 of 31 children (87%). The values of the sinuatrial conduction time were then precisely measured directly according to the electrocardiogram from the sinus node. The sinuatrial conduction time measured directly was significantly longer in 6 children with sick sinus syndrome (138.3 +/- 10.3 msec, mean +/- standard deviation) than in 21 normal children (66.9 +/- 14.4 msec, mean +/- standard deviation). No overlap was found between them. Furthermore, comparison was made between the children and the adults (7 cases with sick sinus syndrome, 32 cases with normal sinus nodal function). The results suggested that the electrocardiogram recorded from the sinus node may be a valuable and promising technique for the evaluation of sinus nodal function and in the accurate diagnosis of the sick sinus syndrome in children.

[Effects of stenosis on blood flow in the coronary artery of dogs]

The effects of stenosis on coronary blood flow (CBF) were studied in 22 open-chest mongrel dogs. A progressive stenosis was produced by a micrometer constrictor on the left circumflex coronary artery. Mean aortic pressure (Pa), distal coronary pressure (Pc) and stenotic segment pressure drop (delta P) were measured. Curve of CBF versus % stenosis showed that CBF was relatively constant with stenosis less than 85%, CBF rapidly decreased with stenosis of 85-95%, and then slowly reduced as stenosis was further increased. The change in CBF versus % stenosis was expressed as follows: CBF = 1.48 X 10(10) theta -27.6 A (where A = % stenosis in lumen area). With progressive coronary artery stenosis (greater than 75%), the change in percent stenosis and Pc showed a negative correlation: Pc = 159.1-1.36A (r = -0.73, P less than 0.01); the change in Pc and CBF showed a positive correlation: Pc = 16.9 + 1.3 CBF (r = 0.74, P less than 0.01).

[Measurement of anticardiolipin antibodies and its significance in systemic lupus erythematosus]

A method for detection of anticardiolipin (ACL) antibodies with enzyme-linked immunosorbent assay was developed. Microtitre plates were coated with cardiolipin at a concentration of 20 micrograms/ml by evaporation under 4 degree centigrade overnight. Non-specific binding of diluted sera was eliminated by blocking of plates with 10% fetal calf serum in phosphate buffered saline (FCS/PBS) for 2 hours at room temperature. Sera (50 microliters/well) at a dilution of 1:100 were incubated for 2 hours at room temperature. Horseradish peroxidase conjugated rabbit anti-human IgG, IgM, IgA at a dilution of 1:2000, 1:1000, 1:500 respectively was added to the wells, and incubated for one and half hours at room temperature. The results were read at 490nm after incubation with substrates at 37 degree centigrade. 85 patients with systemic lupus erythematosus (SLE), 45 with rheumatoid arthritis (RA), 25 with progressive systemic scleroderma (PSS), and 18 primary Sjogren's syndrome were tested. The frequency of ACL antibody in SLE (48%) was much higher than that in RA (11%), PSS (12), SS (5.5). Three isotypes of ACL (IgG, IgM, IgA) were detected in the study with predominance of IgG isotype. ACL antibody was significantly associated with thrombosis, cutaneous vasculopathy, thrombocytopenia, and spontaneous abortion in patients with SLE. Strong relationship between ACL antibody and lupus anticoagulant was found. There was no correlation between ACL and anti-DNA antibodies, nor was ACL and VDRL test. The level of ACL antibody could be reduced by use of corticosteroids.

Benzylisoquinoline compounds inhibit the ability of calmodulin to activate cyclic nucleotide phosphodiesterase

Benzylisoquinoline compounds antagonised the ability of calmodulin (CaM) to stimulate the activity of calmodulin-dependent cyclic nucleotide phosphodiesterase (CaM-PDE). This 'anti-CaM' activity was related to the hydrophobicity of the non-polar terminal region of the antagonist molecule. Antagonistic potency increased with the increase of hydrophobicity; the anti-CaM activity did not change when the polar terminus was a tertiary amine or quarternary amine. The anti-CaM potency was greater for bisbenzylisoquinoline compounds than for monobenzylisoquinoline compounds. Among the bisbenzylisoquinoline compounds anti-CaM pathway was: D3 greater than D2 berbamine greater than daurisoline greater than dauricine. Compound D3, which exhibited an IC50 value of 2.8 microM, was one of the most potent calmodulin antagonists, among benzylisoquinoline compounds, so far reported.

Blood pressure reduction in hypertensive-diabetic rats by the somatostatin analog MK-678

A hypotensive effect of an orally-administered cyclopeptide somatostatin analog, MK-678, has been demonstrated in a hypertensive diabetic rat model. Sustained blood pressure reduction failed to occur when the drug was administered to the spontaneously hypertensive rat. The mechanism of hypotension appears independent of effects on a variety of hormones including insulin, glucagon, growth hormone, and components of the renin-angiotensin system including renin activity, plasma angiotensin converting enzyme, and aldosterone.