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Biomedical subjects

M Lorber

Publications and source records attributed to M Lorber.

At least 55 records · Page 3Linked to original sources
PubMed1995

Systemic lupus erythematosus and thymoma--a double-edged sword.

The coexistence of systemic lupus erythematosus (SLE) and thymoma is rare. We describe 2 female patients with this combination. A 48-year-old woman presented with dyspnea due to a left pleural effusion. Her past history revealed over the previous 3 years the development of anemia, thrombocytopenia, alopecia, pericardial effusion and proteinuria. Four months prior to this hospitalization, the patient was first admitted due to purpura. At that time, laboratory tests revealed an elevated sedimentation rate, elevated titers of ANA and anti-DNA. Chest X-ray demonstrated a widened mediastinum, and upon operation an encapsulated thymoma was excised. Four months following the thymectomy, the patient is unresponsive despite high dose steroid therapy. Another patient, a 30-year-old woman, presented with SLE (cutaneous, arthritis, anemia, positive ANA and high titers of anti-DNA) and thymoma simultaneously. Six years after thymectomy the patient is in SLE remission. Thymectomy in mice prone to autoimmunity (NZB/W mice) has been shown to accelerate the autoimmune manifestations. Conversely, the opposite effect is seen in MRL/lpr mice. The immunological effect of adult thymectomy on the course of human SLE remains to be established, on a larger series of patients. It seems that the heterogenicity of human patients is exemplified by the contrasting effects of thymectomy for thymoma in SLE patients.

Adult↗
PubMed1995

Anti-neuronal antibodies in antiphospholipid syndrome with central nervous system involvement: the difference from systemic lupus erythematosus.

The presence of antineuronal antibodies was compared in 43 patients with primary aPLS and 57 patients with neuropsychiatric SLE. Fifty-eight patients with Guillain-Barré syndrome and 72 normal healthy donors served as control groups. Seventeen patients in the study group had aPLS associated with CNS involvement. Antineuronal antibodies were studied in the sera employing a novel flow cytometric assay. The frequency of antineuronal antibodies in patients with aPLS and CNS involvement was not significantly different from that of patients with aPLS without CNS disease or from that found in the control groups (12%, 19% and 7%, respectively). However, it was significantly different from that found in SLE patients with CNS involvement (60%) (P < 0.001). Our results provide further evidence that unlike CNS-SLE, the major mechanism of CNS involvement in patients with primary aPLS might not be autoantibody (antineuronal) mediated, but rather 'thrombotic' in origin, or due to yet unknown factors.

Antiphospholipid Syndrome↗
PubMed1995

The presence of antiphospholipid antibodies in acute myocardial infarction.

This study was undertaken to determine if there is an association between increased titers of five different antiphospholipid antibodies (aPLA) in young patients' sera and the occurrence of acute myocardial infarction (AMI). Antibodies to anticardiolipin (aCL), anti-phosphatidylserine (aPS), antiphosphatidylinositol (aPI), anti-phosphatidylcholine (aPC), and anti-phosphatidylethanol amine (aPEA) were measured in 214 patients (102 patients, 102 healthy controls and 10 patients with antiphospholipid syndrome). These antibodies were measured twice (within 4h of onset of acute myocardial ischemic chest pain and 3 months after the myocardial infarction) by enzyme linked immunosorbent assay (ELISA). Elevated titers of four different aPLA were detected in 6.9% of all patients with AMI on hospitalization. Titers of aPLA in AMI were elevated in the younger age group < 50 years old (P < 0.001) and in men only (not statistically significant). No correlation was found between the presence of aPLA and cardiovascular risk factors (smoking, hypertension, diabetes mellitus and hyper-cholesterolemia). Three of the seven patients with increased titers of aPLA did not have any other cardiovascular risk factors. The titers of aPLA were within normal range 3 months after AMI. Evidence of significantly elevated titers of different aPLA at the early stage of AMI suggests that these autoantibodies are present before the AMI and are not secondary to them. The disappearance of the elevated aPLA 3 months after AMI may be due to an absorption effect or possibly a cyclic phenomenon similarly found in other autoimmune diseases. aPLA may be an additional risk factor for AMI, and should especially be considered in a patient of the younger age group without apparent cardiovascular risk factors.

Adult↗
PubMed1994

Development and validation of an air-to-beef food chain model for dioxin-like compounds.

A model for predicting concentrations of dioxin-like compounds in beef is developed and tested. The key premise of the model is that concentrations of these compounds in air are the source term, or starting point, for estimating beef concentrations. Vapor-phase concentrations transfer to vegetations that cattle consume, and particle-bound concentrations deposit onto soils and these vegetations as well. Congener-specific bioconcentration parameters, coupled with assumptions on cattle diet, transform soil and vegetative concentrations into beef fat concentrations. The premise of the validation exercise is that a profile of typical air concentrations of dioxin-like compounds in a United States rural environment is an appropriate observed independent data set, and that a representative profile of United States beef concentrations of dioxin-like compounds is an appropriate observed dependent result. These data were developed for the validation exercise. An observed concentration of dioxin toxic equivalents in whole beef of 0.48 ng/kg is compared with a predicted 0.36 ng/kg. Principal uncertainties in the approach are identified and discussed. A major finding of this exercise was that vapor phase transfers of dioxin-like compounds to vegetations that cattle consume dominate the estimation of final beef concentrations: over 80% of the modeled beef concentration was attributed to such transfers.

Air Pollutants↗
PubMed1994

The coexistence of systemic lupus erythematosus with other autoimmune diseases: the kaleidoscope of autoimmunity.

Patients with systemic lupus erythematosis (SLE) often manifest features of other autoimmune diseases. In this review, we provide a detailed compendium of features of SLE that overlap with other conditions. This compendium is important because a critical feature in our understanding of autoimmunity has been the clustering of coexisting/different autoimmune diseases both within an affected patient and within a pedigree. Indeed, autoimmune disorders share a variety of similar clinical and serological defects. For example, all autoimmune disorders are associated with the elaboration of autoantibodies and/or the production of self-reactive mononuclear cell populations; many have high levels of immune complexes and defects in cell-mediated immunity. Several diseases share similar genetic backgrounds, as reflected by study of loci within the major histocompatibility complex. In part the coassociation is due to common genetic tendencies with different environmental precipitating agents (trigger mechanisms). It is likely that many factors can modulate the immune system to autoimmunity in the presence of an appropriate genetic background, eg, drugs, viral infections, UV irradiation, and toxins, ie, toxic oil syndrome and L-tryptophan-induced eosinophilic myalgia. The coexistence of SLE with other autoimmune diseases is an excellent venue to understand these events, and we believe that the presence of other autoimmune diseases in patients with SLE can be called the kaleidoscope of autoimmunity.

Autoimmune Diseases↗
PubMed1994

Enzyme immunoassay for the detection of isoxazolyl penicillin antibiotics in milk.

Polyclonal antibodies were raised against isoxazolyl penicillins in rabbits after immunization with a cloxacillin-human serum albumin conjugate. The antisera were tested in direct and indirect competitive enzyme immunoassays (EIAs), using glucose oxidase or horseradish peroxidase conjugates of oxacillin, cloxacillin, or dicloxacillin, respectively, as the labelled antigen. The relative cross-reactivities of each test system with oxacillin, cloxacillin, and dicloxacillin, determined from the amount of antibiotic required for 50% inhibition of labelled antigen binding, were dependent on the antibiotic used as the labelled antigen. Other beta-lactam antibiotics did not cross-react in these test systems. In a direct EIA using a cloxacillin-horseradish peroxidase conjugate, cloxacillin and dicloxacillin in milk were detected at levels of 10 and 30 ng ml-1; the average recoveries at these levels were 102 and 84%, respectively.

Animals↗
PubMed1994

Systemic lupus erythematosus: predisposition for uterine cervical dysplasia.

A previous retrospective study has found an increased risk of uterine cervical atypia in women with systemic lupus erythematosus (SLE) who have been treated with cytotoxic drugs. Our objective was to prospectively reveal any increased incidence of cervical atypia in SLE patients and to evaluate the relationship to previous chemotherapy. A total of 39 SLE women were prospectively referred for cytologic PAP smears of the uterine cervix. A significantly higher incidence of cervical atypia was found in SLE women (35.9%) compared with non-SLE control groups (< or = 5%; P < 0.01). No significant difference was found between the incidence of atypia in patients previously treated by cytotoxic medications such as cyclophosphamide pulses or methotrexate (4 of 9) compared with SLE women not receiving cytotoxic drugs (10 of 30). Colposcopically directed biopsies revealed three cases of cervical intraepithelial neoplasia (CIN) I-III (23%) among the cases with atypia. We conclude that women with SLE should have regular cytologic cervical smears because of a significantly increased incidence of atypia, regardless of previous cytotoxic therapy.

Adolescent↗
PubMed1993

Regional differences within the external 'duct' of the rat exorbital lacrimal gland.

The lacrimal cord is the fibrous structure that extends between the rat exorbital lacrimal gland and the eyelid. Disagreement exists about the number of ducts it contains and with which lid the orifice is associated. Therefore, 18 lacrimal cords from adult rats were studied by light microscopy. Additionally, in five specimens the continuations of the major ducts were observed immediately intraglandularly. Adjacent to the exorbital lacrimal gland, the lacrimal cord may contain six or more ducts. Farther toward the eye, it has five, four, and then three ducts; the latter typically at about its midpoint. Close to the infraorbital gland two or one are present. Approaching the temporal aspect of either lid, the ducts of both the infraorbital and exorbital lacrimal glands course within the lacrimal cord and usually merge. In some adult rats, when the eyelids are retracted laterally, it is evident that a crescentic fold of the palpebral conjunctiva contains a vertical pair of whitish, convex structures, the 'temporal canthal domes'. When present, one can serve as a marker for the duct orifice located close to the conjunctival fornix. Pseudostratified columnar epithelium lines the ducts from the orifice to the region of the infraorbital lacrimal gland. From the latter toward the exorbital lacrimal gland the epithelium may become pseudostratified cuboidal. That type exists close to and immediately within the exorbital gland. The variation in duct number within the lacrimal cord would have physiological consequences. By analogy with the circulatory system, it is expected that flow would occur more slowly within the multiple ducts in and near the exorbital lacrimal gland than in the one or two near the canthus. Where flow is slower, contact time of the secretion with the duct epithelium would be greater. Thus, modification of the lacrimal secretion is likely not to occur uniformly in the duct system but would take place primarily in and near the exorbital lacrimal gland rather than toward the duct orifice.

Animals↗
PubMed1993

Prevention of fetal loss in experimental antiphospholipid syndrome by low-molecular-weight heparin.

OBJECTIVE: The purpose of this study was to compare the effectiveness of low-molecular-weight heparin with regular heparin in the prevention of fetal resorption in mice with the antiphospholipid syndrome. STUDY DESIGN: Antiphospholipid syndrome was passively induced in ICR mice by injecting them with anticardiolipin antibodies on the first day of pregnancy. Subsequently, these mice were treated with low-molecular-weight heparin in two different doses, with regular heparin, and with a placebo. On gestational day 17 the mice were killed by cervical dislocation, and the pregnancy outcome was evaluated. Statistical analysis was performed by means of a one-way analysis of variance using Bonferroni's t test. RESULTS: Treatment with low-molecular-weight heparin resulted in a resorption rate of 22.4% as opposed to 41.4% in mice with antiphospholipid syndrome that were given regular heparin and 51.7% in nontreated controls. CONCLUSION: We conclude that low-molecular-weight heparin can prevent fetal resorptions in mice with antiphospholipid syndrome.

Animals↗
PubMed1993

Inhibitor(s) of natural anti-cardiolipin autoantibodies.

IgG fractions were purified on Sepharose anti-human IgG column from eight sera of healthy donors, having no anti-cardiolipin (aCL) activity as measured by anti-cardiolipin ELISA assay (aCL-ELISA). All the IgG fractions, after elution with 4.9 M MgCl2, reacted with CL. The antigen-binding characteristics of the IgG fractions purified from normal human serum (NHS) were similar to those of IgG fractions purified from sera of four patients with the anti-phospholipid syndrome (APLS). Competition assay confirmed the specificity of the binding of the purified IgG fractions to CL. The same results have been achieved with IgG fractions purified on Sepharose Protein-A column. The binding to CL was completely inhibited by either whole NHS and sera from various animal species, or by beta 2-glycoprotein I (beta 2-GPI). Our results support the notion of the existence of both natural anti-CL antibodies and serum inhibitor(s) in sera of healthy individuals. It is conceivable that in part the pathogenesis of APLS entails defects in the natural inhibitors of aCL antibodies.

Antibodies, Anticardiolipin↗
PubMed1993

Detection of anti-phospholipid and anti-DNA antibodies and their idiotypes in newborns of mothers with anti-phospholipid syndrome and SLE.

The titers, isotypes and idiotypes of antiphospholipid and anti-dsDNA antibodies were determined in seven pairs of mothers with antiphospholipid syndrome (APLS) and their offspring, in 11 pairs of SLE mothers and their matched infants and in seven respective pairs of healthy subjects. In addition, maternal as well as fetal sera were evaluated for the presence of anti-SSA (Ro), anti-SSB (La) and anti-70 kd RNP autoantibodies. In the sera from APLS patients, as well as in the sera from their offspring, the mean antibody titer of IgG aCL was found to be significantly higher then the corresponding value in the control group (P < 0.01). Highly significant increased titers of IgG anti-DNA antibodies were found in the sera of SLE mothers and their matched offspring (P < 0.0008). The prevalence of anti-SSA, anti-SSA, and anti-70Kd RNP antibodies was lower then that of antiphospholipid and anti-dsDNA antibodies. Only one of the respective offspring had increased levels of these antibodies. The quantity of maternal antibodies transferred to the fetus was depended on their concentration in the maternal circulation, as well as on their type and specificity. Follow-up of newborn sera showed a progressive decrease in the antiphospholipid antibody titers during 3 months. After 6 months it was undetected. Our results point to a transplacental transfer of aCL and anti-DNA antibodies, a phenomenon which is not necessarily associated with respective clinical manifestations, in contrast to the classical humoral mediated autoimmune diseases (e.g. myasthenia gravis).

Adult↗
PubMed1992

Elastic fibers in the duct system of the rat submandibular salivary gland.

The submandibular salivary gland originates from the floor of the mouth whose mucosa contains elastic fibers. Therefore, such fibers were sought in the duct system of the derivative organ. In adult rats, light microscopy has indeed revealed fine, circumferential, elastic fibers near the basement membrane of the duct epithelium. In the larger extralobular ducts, they were separated from several layers of longitudinal elastic fibers by a capillary-rich zone sparse in elastic fibers except for fine angular ones. More peripherally, larger angular-appearing fibers were frequently present near the submandibular parasympathetic ganglia in the duct wall. As duct diameter decreased, elastic fiber size and number diminished. Intralobularly, the smaller striated ducts, granular and intercalated ducts, and acini generally lacked such fibers. Electron microscopy of the extraglandular portion of the main duct revealed fibrils extending from both fibroblasts and elastic fibers that were close to the epithelium. Microfibrils coursed from them toward the lamina densa. Anchoring filaments joined the lamina densa to the basal plasma membrane of the epithelium. Elastic fibers also appeared to connect to both capillaries and collagen via finer intermediate structures. These associations might permit dynamic interactions of fibroblasts, fibers, smaller fibrillar components, vasa, and the duct epithelium. This interplay could occur during feeding and grooming when tongue protrusion and neck extension stretch the submandibular duct and the gland itself. As a result, the tensile forces engendered could modify cell geometry and the calibers of the larger ducts' lumens and intercellular spaces, thus affecting the flow and composition of salivary secretion.

Animals↗
PubMed1992

Frequent induction of insulin autoantibodies by D-penicillamine in patients with rheumatoid arthritis.

D-Penicillamine is a drug known to induce various immunological abnormalities. We used a competitive radiobinding assay, to evaluate the presence of insulin autoantibodies in 42 patients with rheumatoid arthritis (RA), under various treatment modalities. In 11/42 (26.2%) patients, the levels of insulin autoantibodies (range 59-1970 nU/ml) exceeded our upper limit of normal range (50 nU/ml). Nine of these 11 (81.8%) insulin autoantibodies positive patients had been treated with D-penicillamine. Out of 21 D-penicillamine treated patients, 9 (42.9%) were insulin autoantibodies positive (range 80 to 1970 nU/ml). An inverse correlation was found between the concentration of insulin autoantibodies and the time interval since the last drug administration, R = -0.58 (p < 0.05). No correlation was found between the autoantibodies levels and age, or duration of D-penicillamine treatment. In summary, elevated concentration of serum insulin autoantibodies are most probably induced by D-penicillamine therapy in patients with RA and tend to decrease after the drug withdrawal.

Adult↗
PubMed1992

Actigraphic measurements of sleep in rheumatoid arthritis: comparison of patients with low back pain and healthy controls.

Actigraphic recordings during sleep were carried out in patients with rheumatoid arthritis (RA), in patients with chronic low back pain, and in healthy controls for 4 consecutive nights. All derived measures of sleep quality showed that the sleep of patients with RA was significantly poorer than controls, while patients with chronic low back pain had sleep quality not significantly different from either group. Polysomnographically defined periodic movements in sleep were significantly related to sleep efficiency in patients with RA. Clinical status in these patients was significantly related to several actigraphic sleep measures.

Arthritis, Rheumatoid↗