Imaging Mass Spectrometry and Proteome Analysis of Marek's Disease Virus-Induced Tumors

The highly oncogenic alphaherpesvirus Marek's disease virus (MDV) causes immense economic losses in the poultry industry. MDV induces a variety of symptoms in infected chickens, including neurological disorders and immunosuppression. Most notably, MDV induces transformation of lymphocytes, leading to T cell lymphomas in visceral organs with a mortality of up to 100%. While several factors involved in MDV tumorigenesis have been identified, the transformation process and tumor composition remain poorly understood. Here we developed an imaging mass spectrometry (IMS) approach that allows sensitive visualization of MDV-induced lymphoma with a specific mass profile and precise differentiation from the surrounding tissue. To identify potential tumor markers in tumors derived from a very virulent wild-type virus and a telomerase RNA-deficient mutant, we performed laser capture microdissection (LCM) and thereby obtained tumor samples with no or minimal contamination from surrounding nontumor tissue. The proteomes of the LCM samples were subsequently analyzed by quantitative mass spectrometry based on stable isotope labeling. Several proteins, like interferon gamma-inducible protein 30 and a 70-kDa heat shock protein, were identified that are differentially expressed in tumor tissue compared to surrounding tissue and naive T cells. Taken together, our results demonstrate for the first time that MDV-induced tumors can be visualized using IMS, and we identified potential MDV tumor markers by analyzing the proteomes of virus-induced tumors.IMPORTANCE Marek's disease virus (MDV) is an oncogenic alphaherpesvirus that infects chickens and causes the most frequent clinically diagnosed cancer in the animal kingdom. Not only is MDV an important pathogen that threatens the poultry industry but it is also used as a natural virus-host model for herpesvirus-induced tumor formation. In order to visualize MDV-induced lymphoma and to identify potential biomarkers in an unbiased approach, we performed imaging mass spectrometry (IMS) and noncontact laser capture microdissection. This study provides a first description of the visualization of MDV-induced tumors by IMS that could be applied also for diagnostic purposes. In addition, we identified and validated potential biomarkers for MDV-induced tumors that could provide the basis for future research on pathogenesis and tumorigenesis of this malignancy.

Parallelized Monte Carlo software to efficiently simulate the light propagation in arbitrarily shaped objects and aligned scattering media

A GPU-based Monte Carlo software (MCtet) was developed to calculate the light propagation in arbitrarily shaped objects, like a human tooth, represented by a tetrahedral mesh. A unique feature of MCtet is a concept to realize different kinds of light-sources illuminating the complex-shaped surface of an object, for which no preprocessing step is needed. With this concept, it is also possible to consider photons leaving a turbid media and reentering again in case of a concave object. The correct implementation was shown by comparison with five other Monte Carlo software packages. A hundredfold acceleration compared with central processing units-based programs was found. MCtet can simulate anisotropic light propagation, e.g., by accounting for scattering at cylindrical structures. The important influence of the anisotropic light propagation, caused, e.g., by the tubules in human dentin, is shown for the transmission spectrum through a tooth. It was found that the sensitivity to a change in the oxygen saturation inside the pulp for transmission spectra is much larger if the tubules are considered. Another "light guiding" effect based on a combination of a low scattering and a high refractive index in enamel is described.

Broadband Optical Properties of Milk

Dairy products play an important role in our daily nutrition. As a turbid scattering medium with different kinds of particles and droplets, each alteration of these components changes the scattering properties of milk. The goal of this work is the determination of the amount of main scattering components, the fat droplets and the casein micelles, by understanding the light propagation in homogenized milk and in raw milk. To provide the absolute impact of these milk components, the geometrical and optical properties such as the size distribution and the refractive index (RI) of the components have to be examined. We determined the reduced scattering coefficient [Formula: see text] and the absorption coefficient [Formula: see text] from integrating sphere measurements. By use of a collimated transmission setup, the scattering coefficient [Formula: see text] was measured. Size measurements were performed to validate the influence of the fat droplet size on the results of the scattering properties; also, the RI of both components was determined by the said coefficients. These results were used to determine the absolute impact of the milk components on the scattering behavior. By fitting Mie theory calculations on scattering spectra [Formula: see text] and [Formula: see text] from different raw milk samples, it was possible to get reliable values for the concentrations of fat and casein and for the size of the fat droplets. By destroying the casein micelles, it was possible to separate the influence of the different scattering components on scattering behavior.

Monte Carlo modeling of polarized light propagation: Stokes vs. Jones. Part I

This bipartite comparative study aims at inspecting the similarities and differences between the Jones and Stokes-Mueller formalisms when modeling polarized light propagation with numerical simulations of the Monte Carlo type. In this first part, we review the theoretical concepts that concern light propagation and detection with both pure and partially/totally unpolarized states. The latter case involving fluctuations, or "depolarizing effects," is of special interest here: Jones and Stokes-Mueller are equally apt to model such effects and are expected to yield identical results. In a second, ensuing paper, empirical evidence is provided by means of numerical experiments, using both formalisms.

Monte Carlo modeling of polarized light propagation: Stokes vs. Jones. Part II

In this second part of our comparative study inspecting the (dis)similarities between "Stokes" and "Jones," we present simulation results yielded by two independent Monte Carlo programs: (i) one developed in Bern with the Jones formalism and (ii) the other implemented in Ulm with the Stokes notation. The simulated polarimetric experiments involve suspensions of polystyrene spheres with varying size. Reflection and refraction at the sample/air interfaces are also considered. Both programs yield identical results when propagating pure polarization states, yet, with unpolarized illumination, second order statistical differences appear, thereby highlighting the pre-averaged nature of the Stokes parameters. This study serves as a validation for both programs and clarifies the misleading belief according to which "Jones cannot treat depolarizing effects."

Multiple scattering of polarized light: comparison of Maxwell theory and radiative transfer theory

For many research areas in biomedical optics, information about scattering of polarized light in turbid media is of increasing importance. Scattering simulations within this field are mainly performed on the basis of radiative transfer theory. In this study a polarization sensitive Monte Carlo solution of radiative transfer theory is compared to exact Maxwell solutions for all elements of the scattering Müller matrix. Different scatterer volume concentrations are modeled as a multitude of monodisperse nonabsorbing spheres randomly positioned in a cubic simulation volume which is irradiated with monochromatic incident light. For all Müller matrix elements effects due to dependent scattering and multiple scattering are analysed. The results are in overall good agreement between the two methods with deviations related to dependent scattering being prominent for high volume concentrations and high scattering angles.

Correspondences of hydrostatic pressure in periodontal ligament with regions of root resorption: a clinical and a finite element study of the same human teeth

INTRODUCTION

The main objectives of this study were to generate individual finite element models of extracted human upper first premolars, and to simulate the distribution of the hydrostatic pressure in the periodontal ligament (PDL) of these models for evaluation of the risk of root resorption.

METHODS

The individual extracted teeth were from a previous in vivo study that investigated root resorption after application of continuous intrusive forces. The results of experimental examination and simulations were compared on these identical tooth roots. The applied force system was 0.5N and 1.0N of intrusive force.

RESULTS

The simulated results during intrusion of 0.5N showed regions near the apical thirds of the roots with hydrostatic pressure over the human capillary blood pressure. These regions correlated with the electron microscopies of previous studies performed in Brazil with the identical teeth. An increased force of 1.0N resulted in increased areas and magnitudes of the hydrostatic pressure.

CONCLUSIONS

The key parameter indicating beginning root resorption used in this study was an increased value for hydrostatic pressure in the PDL.

Periodontal Ligament Hydrostatic Pressure with Areas of Root Resorption after Application of a Continuous Torque Moment

Objective: To evaluate the risk of root resorption, individual finite element models (FEMs) of extracted human maxillary first premolars were created, and the distribution of the hydrostatic pressure in the periodontal ligament (PDL) of these models was simulated.

Materials and Methods: A continuous lingual torque of 3 Nmm and 6 Nmm respectively was applied in vivo to the aforementioned teeth. After extraction, FEMs of these double-rooted teeth were created based on high-resolution microcomputed tomographics (micro CT, voxel size: 35 microns). This high volumetric resolution made the recognition of very small resorption lacunae possible. Scanning electron micrographs of the root surfaces were created as well. This enabled the investigation of advantages and disadvantages of the different imaging techniques from the viewpoint of the examination of root resorption. Using the FEMs, the same loading conditions as applied in vivo were simulated.

Results: The results of clinical examination and simulations were compared using the identical roots of the teeth. The regions that showed increased hydrostatic pressure (>0.0047 MPa) correlated well with the locations of root resorption for each tooth. Increased torque resulted in increased high-pressure areas and increased magnitudes of hydrostatic pressure, correlating with the experiments.

Conclusion: If hydrostatic pressure exceeds typical human capillary blood pressure in the PDL, the risk of root resorption increases.

Protease expression in the supernatant of Chinese hamster ovary cells grown in serum-free culture

The protease activity secreted by the Chinese Hamster Ovary (CHO-K1) cell line grown in serum-free medium was examined by substrate gel electrophoresis (zymography). The cell line expressed extracellular proteases that were active on gelatin zymograms but not on casein zymograms. The main protease band visible by gelatin zymography was approx. 92 kDa. Incubation of the conditioned medium with aminophenylmercuric acetate (APMA) resulted in the appearance of gelatinase activity at 82 kDa. Incubation of the conditioned media with EDTA significantly decreased the gelatinolytic activity of both the 92 kDa and 82 kDa forms, indicating the gelatinase responsible was a metalloprotease. Immunoblotting of the conditioned medium showed the gelatinase to be the pro- form of matrix metalloprotease-9 (pro-MMP-9), also known as gelatinase B.

Antibody against CD20 in patients with B cell malignancy

Cancer patients may make antibodies against antigens on the surface of their malignant cells due either to the expression of unique antigens or to dysregulated responses to self antigens. Patients with B cell malignancy frequently produce autoantibodies and may therefore be a source of immunoglobulin genes for the production of phage display antibody libraries directed against tumour-associated antigens. Patients with autoimmune disease have circulating antibodies against lymphocyte surface antigens, and may also provide a good starting point for the production of a library of lymphocyte-reactive antibody structures. In this study, plasma and serum samples from patients with B cell malignancy or Sjogren's syndrome and from healthy controls were screened for antibodies against the B cell membrane antigens CD20. While the majority of samples showed very low reactivity, some individuals did show significant and reproducible binding to CD20. To identify a good donor for library construction, it would be advisable to screen donors for antibody against the antigens of interest.

[Quality of vision screening in childhood]

BACKGROUND

In Germany the paediatricians use three different visual acuity tests (Pictures, Rodenstock-Test, H-Test). We investigated the effectiveness of these procedures.

SUBJECTS

In this study 303 children were referred by paediatricians to the study group in the Cologne Augenklinik. They were fully examined by an orthoptist and an ophthalmologist (gold standard).

RESULTS

From these data the sensitivity and specificity of the tests used by the paediatricians were calculated. Only the H-Test proved to be satisfactory.

CONCLUSION

The actual situation of screening for amblyopia by paediatricians in children aged 3 1/2 to 4 is unsatisfactory in Germany. Paediatricians and ophthalmologists should use a similar test for visual acuity. Continuing education of medical personnel is desirable to ensure an adequate quality of screening.

[Universal organ involvement in Rendu-Osler-Weber disease: interdisciplinary diagnosis and interventional therapy]

A case of hereditary hemorrhagic teleangiectasia (HHT, Morbus Rendu-Osler-Weber) in a 63-years-old patient presenting with recurrent gastrointestinal and nasopharyngeal bleeding who required transfusion of 100-200 units of red blood cell concentrate a year is reported. Endoscopically, one source of bleeding could be located in the upper part of the jejunum. Multiple Osler spots were found in the antrum, the bulbal and descending part of the duodenum without signs of bleeding. Colonoscopy revealed no further lesions. Selective mesentericography visualized dilatation of the arterial arcardes in the duodenal region with early venous filling. During coeliacography, parenchymal deposits of contrast medium appeared in the liver. Numerous angiodysplastic arterial alterations from the lower ethmoidal arteria were shown to be another source of bleeding. They were embolized using microspheres and thereby terminating epistaxis. Termination of epistaxis was the crucial prerogative for the consecutive aortal valve replacement. At abdominal ultrasound, the liver harbored multiple anechoic lesions and a bigger cystic formation with portal inflow and early venous distribution. This teleangiectatic portovenous-malformation was confirmed on abdominal computertomography and on T1-enhanced images of MRT, too. This case examplifies the universal character of organ distribution in HHT and underlines the value of complementary diagnostic and therapeutic modalities.

Further evidence linking urolithiasis and blood coagulation: urinary prothrombin fragment 1 is present in stone matrix

The fact that organic material is always present and distributed throughout each renal calculus suggests that it may play a role in stone formation. The organic matrix of calcium oxalate (CaOx) crystals freshly generated in urine in vitro contains urinary prothrombin fragment 1 (UPTF1) as the principal protein. In this initial study, matrix was extracted from 12 renal calculi and evaluated for the presence of UPTF1 using Western blotting. UPTF1 was present in all eight stones whose principal component was CaOx, and in one of two stones which consisted mainly of calcium phosphate (CaP). UPTF1 was absent from the two struvite calculi examined. The relationship between CaP and UPTF1 was explored further. Matrix harvested from CaP crystals freshly generated in urine in vitro was also shown to contain UPTF1 as its principal component. Our inability to detect UPTF1 in one mixed CaOx/CaP stone may be related to our methods of matrix retrieval, while its absence from two struvite stones argues against it being present in the other stones merely as a consequence of passive inclusion. This absence may be related to the alkaline environment typical of struvite stone growth. The finding that UPTF1 is present in some renal stones provides the first direct evidence that links blood coagulation proteins with urolithiasis.

Phospholipid binding specificities and idiotype expression of hybridoma derived monoclonal autoantibodies from splenic cells of patients with systemic lupus erythematosus

OBJECTIVE

To analyse the phospholipid binding specificity, functional characteristics and idiotype expression of human hybridoma derived monoclonal autoantibodies (MAb) derived from the spleens of two patients with active systemic lupus erythematosus (SLE).

METHODS

The IgM MAbs binding to phospholipids were generated from spleen cells of two patients (RSP and RT) with active SLE and their specificity of binding to neutral phospholipids (phosphatidyl ethanolamine, phosphatidyl choline, platelet activating factor, sphingomyelin) and negatively charged phospholipids (phosphatidyl glycerol, phosphatidyl serine, phosphatidic acid, phosphatidyl inositol and cardiolipin (CL)) analysed. Binding specificity of cross reactive antibodies (those binding to CL and DNA) was confirmed by fluid phase inhibition assays. Lupus anticoagulant activity and beta 2-glycoprotein-1 (beta 2 GP-1) requirement for the antigen binding of these MAbs were detected using the modified dilute Russell's viper venom test and modified anti-CL enzyme linked immunosorbent assay (ELISA), respectively. Expression of idiotypes (Id) Id RT-84 and Id H3 was analysed using rabbit polyclonal and murine monoclonal anti-idiotype reagents, respectively.

RESULTS

Twelve clones from the patient RSP and eight clones from patient RT were reactive with phospholipids. Marked differences in phospholipid binding of these MAbs were noted, varying from truly polyreactive (RT-72 bound to most phospholipids tested) to monospecific (RT-84 bound only to CL). Furthermore, MAbs RT-84, RT-129, and RSP-57 had lupus anticoagulant activity and required beta 2 GP-1 for CL binding. It was found that 75% of phospholipid binding antibodies from RT clones expressed RT-84 Id, but none from RSP clones did so, and that Id H3 was expressed only by the RT-83 antibody.

CONCLUSION

These results show that human anti-phospholipid MAbs are heterogeneous with respect to phospholipid binding, functional characteristics, and Id expression.

Immunoglobulin gene sequence analysis of anti-cardiolipin and anti-cardiolipin idiotype (H3) human monoclonal antibodies

Heavy and light chain variable region nucleotide sequences were derived from 6 human hybridoma antibodies which bear characteristics of antibodies associated with the phospholipid antibody syndrome. All antibodies originated from non-autoimmune individuals and were polyspecific. Four of these reacted with cardiolipin (and other antigens) and three carried the H3 idiotype which is expressed on a high percentage of disease-associated anti-cardiolipin antibodies. This idiotype was localized to the lambda light chain of the H3 monoclonal antibody and found on two other antibodies which like H3 expressed V lambda 4 or the related V lambda 3 subgroup light chains. The H3 idiotype however did not define these subgroups nor was it required or sufficient for anti-cardiolipin activity. Anti-cardiolipin binding was found in VH1, VH3 and VH4 heavy chain families and in a V kappa 1 light chain. The D region was diverse in both length and gene usage. Although all cardiolipin binding antibodies showed little deviation from germline variable (V) gene sequences, where mutations occurred they tended to be replacement mutations and clustered in complementarity determining regions (CDR) suggesting these B cells were derived from antigen-driven responses. These results from our panel of hybridomas and their comparison to other human antibodies provide extensive information on the diversity of genetic elements which can be used by cardiolipin-binding antibodies. We also show gene sequences which encode the disease-associated H3 idiotype and its location on lambda light chains, which imply that some labda light chains may be preferentially utilized in auto-reactive hybridomas.

Mouse monoclonal anti-idiotypic antibodies to HIV p24: immunochemical properties and internal imagery

Two mouse monoclonal antibodies (VIC5 and VIC6; referred to as Ab1) reacting with the p24 core antigen of HIV-1 were used to produce mouse monoclonal anti-idiotypic antibodies (Ab2). Six anti-idiotypic antibodies were characterized. The five anti-idiotypic antibodies directed against VIC6 partly competed which each other and thus defined a set of overlapping idiotypes on Ab1. All 6 Ab2s inhibited the binding of the corresponding anti-p24 antibody to antigen, although four (W1, Y16, Y6, X14) were markedly more inhibitory than the remaining two (G6, Y11). All six Ab2s were antigen-inhibitable; however the interaction of G6 and Y11 with Ab1 was blocked with considerably less soluble p24 antigen than the remaining four. Correspondingly, G6 and Y11 had lower affinities for Ab1 than did W1, Y6 and X14; the affinity index of Y16 was equivalent to that of Y11. None of the Ab2s reacted with H or L chains of Ab1 after reduction on SDS-gels. Similarly, both Ab1s failed to react with the H or L chains of Ab2. These criteria appeared to define at least four of these Ab2s as internal image antibodies whose image is composed of both H and L chains. The anti-idiotypic antibodies were injected either individually or as a combined preparation of all 6 into syngeneic mice and Porton rats. Despite the presence of anti-anti-idiotypic antibodies (Ab3) in these animals, when used individually no antigen-specific antibodies were found. A small response to p24 antigen was induced in 3 of 6 mice using preparations containing all 6 anti-idiotypes.

[Effective vision screening can decrease the rate of amblyopia]

The quality of screening for testing visual disorders is unsatisfactory. Diagnosis and therapy are generally too late to exploit the advantage therapy can give during the sensitive period of visual acuity. About 10% of the adult population show decreased visual acuity (below 0.8). These persons have a more or less distinct amblyopia. Commonly used visual acuity tests do not allow the crowding phenomenon to be measured, although it is an easily measurable amblyopia characteristic. The most frequently used visual acuity test by German health authorities (R 5/R 11 test with plate No. 120) shows 48% false-negative results. We introduced the H test for preschool children. For school children and adults we developed the C test. To detect amblyopia precisely we designed both tests so that the crowding phenomenon could be measured. Both tests were validated in more than 700 subjects. All persons received an extensive ophthalmological checkup, which was used as the reference for normality. The H test is based on the matching principle and works with musical feedback. The test can be used from the age of 3 years onward. Therefore, the advantage of early therapy can be fully exploited. The H test has a 3% percentage false-negative rate. The C test is based on the Landolt ring. The visual acuity charts are presented as a book (40 cm distance) for measuring near visual acuity and (5 m) for measuring distance visual acuity. The C test has less than 5% false-negative results. Both tests can help in different age groups to diagnose amblyopic cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of two common idiotypes of anticardiolipin antibodies in sera of patients with primary antiphospholipid syndrome, systemic lupus erythematosus and monoclonal gammopathies

The frequency of two common idiotypes of anticardiolipin antibodies (aCL) was determined in sera from three groups of subjects, patients with systemic lupus erythematosus (SLE), with primary antiphospholipid syndrome (PAPS) and with monoclonal gammopathies (MG), as compared to normal population. The idiotype 1.10, which was derived from a patient with active SLE and antiphospholipid syndrome, was found more frequently among patients with PAPS (10.5%, 10.5% and 22.2% in MG, SLE and PAPS, respectively) than the idiotype H3, which was derived from a human hybridoma monoclonal aCL generated from a healthy subject immunized with tetanus and diphtheria. The latter idiotype was detected in 8.7%, 6.5% and 11.7% of patients with MG, SLE and PAPS, respectively. Incidental findings in this study include a high prevalence of aCL among patients with MG (23%) and a high prevalence of anti-dsDNA antibodies, detected only by a sensitive enzyme-linked immunosorbent assay, among patients with PAPS. Our results indicate that idiotypic diversity exists among aCL derived from different sources. Some of these cross-reactive idiotypes may be more pathogenic than others.

The H3 anti-phospholipid idiotype is found in patients with systemic lupus erythematosus (SLE) but not in patients with syphilis

The human H3 idiotype, defined by a mouse monoclonal antibody S2.9, is commonly found in patients with SLE where it is correlated with the amount of anti-cardiolipin antibodies. No correlation between the amount of anti-cardiolipin antibody and the H3 idiotype is found in patients with syphilis. Using the S2.9 antibody, serum from each of 10 patients with SLE and eight patients with syphilis was separated into H3-bearing and H3-negative fractions. Comparison of the partition of anti-cardiolipin antibody in these two groups of patients revealed that much of the anti-cardiolipin antibody (44-91%) was found in the H3+ fraction in patients with SLE; in patients with syphilis, virtually none of the anti-cardiolipin antibody was H3+. In patients with SLE, the H3+ fraction contained both IgG and IgM and antibodies of both kappa and lambda light chains. The H3+ fraction was polyspecific and frequently reacted with dsDNA.

Impaired balance of interleukin-4 and interferon-gamma production in infections with Schistosoma mansoni and intestinal nematodes

In chronic infection with Schistosoma mansoni, IL-4 and IFN-gamma are co-modulated in opposite directions. This was shown when testing sera and cell culture supernatants from 31 Brazilian patients with schistosomiasis before, and three months after treatment with praziquantel. Thorough examinations were undertaken to account for polyparasitism with intestinal nematode infections involving tissue migrating larval stages that may induce analogous changes. Controls free of S. mansoni included a group (n = 17) matching the schistosomiasis patients' parasitation by intestinal nematodes and a group (n = 16) free of helminths other than T. trichiura. Serum IL-4 was greater than 20 pg/ml in 81% of schistosomiasis patients but in only 35 and 25%, respectively, of controls with and without intestinal nematodes. IL-4 data correlated inversely with the mitogen-induced IFN-gamma synthesis. Generation of IL-4 in response to phorbol esters was related to the intensity of infection by schistosomes and intestinal nematodes. The parasitological status three months after therapy with either praziquantel or mebendazole revealed a dichotomy: whereas the ratio of IFN-gamma to IL-4 generated in vitro was identical in uninfected controls and in patients who cleared the parasites, failure to eliminate the parasites was associated with lower IFN-gamma/IL-4 ratios generated in vitro.

Pulsatile insulin infusion and glucose-homeostasis in well-controlled type 1 (insulin-dependent) diabetic patients

Pulsatile, intravenous insulin infusion designed to mimic the portal insulin concentrations that emerge physiologically after a meal, has been postulated to improve glucose tolerance in Type 1 (insulin-dependent) diabetic patients. We studied the effects of insulin pulsing (10 i.v. pulses of human insulin of 0.035 U kg-1 idealised body weight were given, each of 20 s duration, with intervals of 6 min, three times per day covered with adequate administration of glucose) on 2 successive days on glucose-tolerance in nine well-controlled Type 1 diabetic patients on continuous subcutaneous insulin infusion therapy (age 26 (7) years, mean (SD); duration of diabetes 10 (7) years; body mass index 23.4 (2.3) kg m-2; HbA1c 6.0 (0.6)%). On the days before and after the insulin pulsing, the patients were subjected to metabolic assessments by an oral glucose tolerance test (1 g glucose kg-1 body weight) 30 min after the subcutaneous injection of 0.15 U kg-1 body weight regular human insulin and a subsequent bicycle-ergometer test. During these metabolic assessments, plasma free insulin concentrations, plasma glucagon and the non-protein respiratory quotient remained unaffected by the insulin pulsing. However, glucose tolerance deteriorated significantly (maximal glucose concentration 120 min after glucose load was 10.0 mmol l-1 before and 13.9 mmol l-1 after insulin pulsing, P less than 0.01). In conclusion, the pattern of insulin pulsing used in this study did not ameliorate oral glucose homeostasis in well-controlled Type 1 (insulin dependent) diabetic patients.

[Action profile of human ultralente insulin compared with human NPH-insulin]

The effect of human NPH insulin (Protaphan HM) and of human ultralente insulin (Ultratard HM) on the profile of blood-glucose concentration was compared, using the glucose clamp technique, in normal subjects after subcutaneous injection of 12 U each. After Protaphan, insulin concentration rose by 11.0 +/- 1.6 microU/ml; maximal glucose infusion rate (GIR) after five hours was 4.7 +/- 0.5 mg/kg.min. But after the same dosage of Ultratard, insulin concentration rose by only 4.7 +/- 1.0 microU/ml (P less than 0.02) on a maximal GIR after ten hours of 3.2 +/- 0.5 mg/kg.min (no significant difference). Ultratard had up to 70% of the maximal Protaphan effect, the infused amount of glucose, up to maximal effect at 9.5 h (72 +/- 9 g), being significantly lower (P less than 0.02) than after Protaphan (130 +/- 18 g). After, respectively, 16 (Protaphan) and 20 (Ultratard) hours, basal insulin levels were again reached. GIR 19 h after Protaphan injection was 1.3 +/- 0.4 mg/kg.min, while 24 h after Ultratard it was 1.5 +/- 0.2 mg/kg.min, which was not significantly different from the basal rate. The difference between Protaphan and Ultratard lies in the marked initial effect of NPH insulin, up to 10 h after injection. In the later phase of the effect profile both insulins were similar at the chosen dose of 12 U.

The action profiles of human NPH insulin preparations

The complete time-action profiles of four subcutaneously injected human NPH insulin preparations (Protaphane HM/Novo; Insulatard Human/Nordisk; Huminsulin Basal/Eli Lilly; Basal H-Insulin/Hoechst) have been investigated by means of the euglycaemic clamp technique (blood glucose 5.0 mmol l-1). Six normal male subjects were connected to a Biostator on five occasions in randomized order including a control study without insulin injection. A stable basal insulin level of about 10 mU l-1 was established by means of a low dose insulin infusion (0.1 mU kg-1 min-1) which subsequently suppressed C-peptide by 35 +/- 19% (mean +/- SD) to levels of around 0.3 nmol l-1. Twelve units of NPH insulin were injected subcutaneously into the abdominal wall and glucose infusion rates were monitored for 19 h. In the control study, the mean glucose infusion rate was 1.11 +/- 0.60 (range 0.32-1.95) mg kg-1 min-1. Maximal glucose infusion rates, reached 5-7 h after injection, were comparable (4.3-4.9 mg kg-1 min-1) for the four different preparations used. Glucose infusion rates returned to basal rates within the 19 h study period. Mean plasma free insulin levels peaked at 17.5-18.6 mU l-1 3-4.5 h after injection and returned to basal levels within 16 h. The time ranges of greater than 90, greater than 75, greater than 50, and greater than 25% of maximal insulin action (as estimated from glucose infusion rates) revealed no significant differences between the four insulin preparations tested. No significant insulin action was observed beyond 17 h after insulin injection of any preparation.

A common anti-cardiolipin antibody idiotype in autoimmune disease: identification using a mouse monoclonal antibody directed against a naturally-occurring anti-phospholipid antibody

We have recently produced a series of human monoclonal antibodies reacting with cardiolipin. One of these, H3, a polyspecific IgM/k derived from a normal individual, was used to raise mouse monoclonal antibody to its idiotype. Two anti-idiotypic antibodies, S2.9 (IgG2b) and S2.10 (IgM) were selected for their specific reaction with H3.S2.9 did not react with five other human monoclonal antibodies of IgM/k class despite the fact that these shared some antigen-binding characteristics with H3.S2.9 was able to block the binding of H3 to all of its cross-reactive antigens including cardiolipin, while S2.10 was not. S2.9 was equally efficient in blocking the binding of H3 to three of its cross-reactive antigens, cardiolipin, diphtheria and tetanus toxoids; greater than 90% inhibition could be achieved at an equimolar ratio of H3 to S2.9. The anti-idiotype S2.9 was used to demonstrate the presence of the H3 idiotype in serum. This idiotype was found in amounts greater than that seen in 42 normal individuals, in 30 of 36 patients with systemic lupus erythematosus (SLE), eight of 20 patients with rheumatoid arthritis (RA), 8 of 20 patients with Felty's syndrome as well as 10 of 23 patients with syphilis. Not one of nine patients with drug-induced lupus syndrome had abnormal levels. In patients with SLE and Felty's syndrome there was a good correlation between the amount of anti-cardiolipin antibodies and the amount of H3 idiotype (rs = 0.70 and 0.69 respectively). No such correlation was found in syphilitics or in patients with RA. In patients with SLE the H3 idiotype was present on IgM and IgG anti-cardiolipin antibodies. In 15 of 16 SLE sera with high levels of cardiolipin antibody, S2.9 blocked binding of serum antibodies to cardiolipin by 13-72%, with a mean value of 49%. One patient had a high level of anti-cardiolipin antibody which could not be blocked by S2.9. These results indicate that a mouse monoclonal antibody which reacts with an idiotope in the antigen-binding region of a naturally-occurring phospholipid antibody also defines a common idiotype of anti-cardiolipin antibodies in patients with autoimmune disease.

Microplate ELISA for detection of antibodies to DNA in patients with systemic lupus erythematosus: specificity and correlation with Farr radioimmunoassay

A 96-well microplate ELISA for the detection of antibodies to DNA is described. A number of buffers and precoating treatments were used to evaluate the optimal method for coating the plate with DNA. These included pretreatment of the plates with poly-L-lysine or protamine sulfate, and posttreatment with glutaraldehyde, none of which improved the performance of the assay. Whereas bicarbonate and borate coating buffers gave equivalent and satisfactory results, TRIS buffer resulted in very high binding of immunoglobulin to wells not coated with antigen. Sera from groups of patients with autoimmune disease as well as normal sera were tested against plates optimally coated with native E. coli DNA, calf thymus DNA, and heat-denatured DNA. Using native E. coli DNA, virtually none of 35 normal sera had any detectable antibody. With this antigen, as well as with native calf thymus DNA, significant levels of DNA antibody were found only in SLE patients. Most patients with SLE or drug-induced lupus, as well as some patients with rheumatoid arthritis and normal individuals had antibodies that bound to heat-denatured (single-stranded) DNA. Using either native E. coli or calf thymus DNA, a good correlation was found between the amount of DNA antibody detected by ELISA and the Farr-type radioimmunoassay.

Atrial natriuretic factor in various stages of diabetic nephropathy

Plasma concentrations of atrial natriuretic factor (ANF) were measured by radioreceptor assay in 148 insulin-dependent Type I diabetic patients with different stages of diabetic nephropathy. In patients with overt or incipient diabetic nephropathy as well as in patients with glomerular hyperfiltration only, ANF concentrations were elevated when compared with non-nephropathic diabetic and normal subjects. No correlations between ANF and blood pressure, age, diabetes duration, or parameters of metabolic control were found. These findings may indicate a pathophysiologic role of ANF in the development and progression of diabetic nephropathy.

Polyspecific human and murine antibodies to diphtheria and tetanus toxoids and phospholipids

Human-human hybridomas produced from lymphocytes of normal individuals yielded seven clones producing monoclonal antibody reacting with tetanus toxoid. Three of these antibodies cross-reacted with diphtheria toxoid. These three and two others also reacted with cardiolipin and two with other phospholipids. One of the seven antibodies reacted with tetanus and diphtheria toxoids, cardiolipin and single-stranded DNA. All seven antibodies were IgM. To examine further this unusual cross-reactivity serum antibodies from patients with SLE and healthy individuals were affinity-purified to yield diphtheria toxoid antibodies. Six out of nine of these anti-diphtheria preparations contained IgG antibodies which cross-reacted with tetanus toxoid and two of these also reacted with cardiolipin; four preparations cross-reacted with DNA. Anti-cardiolipin and anti-DNA cross-reactivity were found in preparations from both normal and SLE sera. Similar cross-reactivities were demonstrated using four mouse monoclonal IgM antibodies raised against phospholipids. All four of these antibodies reacted with both cardiolipin and tetanus toxoid and two also reacted with diphtheria toxoid and DNA. Using a thiocyanate elution procedure, it was shown that the cross-reactivity of the monoclonal antibodies was not related to their relative affinities. The results clearly indicate that cross-reactive epitopes occur on routinely used toxoid vaccines and self antigens. Antibodies which bind to these cross-reactive epitopes are common and are not restricted in isotype, affinity or species of origin.

Monoclonal alkaline phosphatase-anti-alkaline phosphatase (APAAP) complex: production of antibody, optimization of activity, and use in immunostaining

A mouse monoclonal antibody, FMC55 (an IgG1), to alkaline phosphatase was prepared and evaluated in immunostaining. Clones producing antibody to alkaline phosphatase were selected using a micro-ELISA which identified antibodies forming active soluble complexes (APAAP) with the enzyme. Conditions that influenced the formation of the complex were investigated by using a quantitative assay in which the complex was captured by a bridging anti-mouse antibody. The ratio of FMC55 to enzyme had a major influence on the activity of the complex. Although all complexes had some activity, those that contained excess antibody had reduced ability to bind to anti-mouse antibody because of competition with excess unlabeled antibody. The optimal complex was formed with 3 micrograms of FMC55 per unit of enzyme. This complex contained neither free enzyme nor free antibody. The molecular weight by gel permeation chromatography was 600,000, giving a composition of two enzyme and two antibody molecules or one enzyme and three antibody molecules. The size of the complex was not altered by adding excess antibody or excess enzyme. Immunoblotting showed that FMC55 bound only to the Mr 140,000 homodimeric form of alkaline phosphatase. The APAAP complex was used in combination with biotin-streptavidin-peroxidase reagent to detect two antigens labeled with two different mouse monoclonal antibodies in the same tissue preparation.

The human leucocyte P30 antigen: properties and assessment of value as a clonal marker

FMC3 and FMC29 are monoclonal antibodies which react with a 30,000 Dalton molecule expressed on the lymphocyte surface membrane. The molecule is a protein which does not appear to be N-glycosylated. The antigen, which is also expressed intracellularly, does not appear to be a marker of differentiation or maturation. Polyclonal cell populations, such as peripheral blood lymphocytes, show a bimodal distribution of surface antigen density, whilst monoclonal cell populations analysed quantitatively showed unimodal antigen density distributions. This suggests the antigen may be a clonal marker.

The antigen of mature human B cells detected by the monoclonal antibody FMC7: studies on the nature of the antigen and modulation of its expression

The monoclonal antibody FMC7 delineates a subpopulation of B lymphocytes in normal blood. Expression of the antigen recognized by FMC7 appears to be maturation-linked, and it serves to distinguish different types of B cell leukemia. The data presented here indicate that the antigen is a protein that is integrated in the cell membrane and that is able to interact with the cytoskeleton. The antigen is rapidly synthesized and turned over, is not cell cycle-dependent, and is relatively resistant to changes induced by culture in the presence of a phorbol ester.

The antigen of mature human B cells detected by the monoclonal antibody FMC7: studies on the nature of the antigen and modulation of its expression

The monoclonal antibody FMC7 delineates a subpopulation of B lymphocytes in normal blood. Expression of the antigen recognized by FMC7 appears to be maturation-linked, and it serves to distinguish different types of B cell leukemia. The data presented here indicate that the antigen is a protein that is integrated in the cell membrane and that is able to interact with the cytoskeleton. The antigen is rapidly synthesized and turned over, is not cell cycle-dependent, and is relatively resistant to changes induced by culture in the presence of a phorbol ester.

Measurement of specific antibodies in human intestinal aspirate: effect of the protease inhibitor phenylmethylsulphonyl fluoride

Incorporation of the protease inhibitor phenylmethylsulphonyl fluoride in a solid-phase enzyme-linked immunoassay increased the sensitivity of this assay for detecting antibodies to dietary proteins present in human intestinal aspirate. Its effect was due in part to the prevention of antigen degradation.